Merge branch 'vendor/NVI2'
[dragonfly.git] / contrib / binutils-2.24 / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
4 // Written by Doug Kwan <dougkwan@google.com> based on the i386 code
5 // by Ian Lance Taylor <iant@google.com>.
6 // This file also contains borrowed and adapted code from
7 // bfd/elf32-arm.c.
8
9 // This file is part of gold.
10
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 3 of the License, or
14 // (at your option) any later version.
15
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 // GNU General Public License for more details.
20
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24 // MA 02110-1301, USA.
25
26 #include "gold.h"
27
28 #include <cstring>
29 #include <limits>
30 #include <cstdio>
31 #include <string>
32 #include <algorithm>
33 #include <map>
34 #include <utility>
35 #include <set>
36
37 #include "elfcpp.h"
38 #include "parameters.h"
39 #include "reloc.h"
40 #include "arm.h"
41 #include "object.h"
42 #include "symtab.h"
43 #include "layout.h"
44 #include "output.h"
45 #include "copy-relocs.h"
46 #include "target.h"
47 #include "target-reloc.h"
48 #include "target-select.h"
49 #include "tls.h"
50 #include "defstd.h"
51 #include "gc.h"
52 #include "attributes.h"
53 #include "arm-reloc-property.h"
54 #include "nacl.h"
55
56 namespace
57 {
58
59 using namespace gold;
60
61 template<bool big_endian>
62 class Output_data_plt_arm;
63
64 template<bool big_endian>
65 class Output_data_plt_arm_standard;
66
67 template<bool big_endian>
68 class Stub_table;
69
70 template<bool big_endian>
71 class Arm_input_section;
72
73 class Arm_exidx_cantunwind;
74
75 class Arm_exidx_merged_section;
76
77 class Arm_exidx_fixup;
78
79 template<bool big_endian>
80 class Arm_output_section;
81
82 class Arm_exidx_input_section;
83
84 template<bool big_endian>
85 class Arm_relobj;
86
87 template<bool big_endian>
88 class Arm_relocate_functions;
89
90 template<bool big_endian>
91 class Arm_output_data_got;
92
93 template<bool big_endian>
94 class Target_arm;
95
96 // For convenience.
97 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
98
99 // Maximum branch offsets for ARM, THUMB and THUMB2.
100 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
101 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
102 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
103 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
104 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
105 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
106
107 // Thread Control Block size.
108 const size_t ARM_TCB_SIZE = 8;
109
110 // The arm target class.
111 //
112 // This is a very simple port of gold for ARM-EABI.  It is intended for
113 // supporting Android only for the time being.
114 //
115 // TODOs:
116 // - Implement all static relocation types documented in arm-reloc.def.
117 // - Make PLTs more flexible for different architecture features like
118 //   Thumb-2 and BE8.
119 // There are probably a lot more.
120
121 // Ideally we would like to avoid using global variables but this is used
122 // very in many places and sometimes in loops.  If we use a function
123 // returning a static instance of Arm_reloc_property_table, it will be very
124 // slow in an threaded environment since the static instance needs to be
125 // locked.  The pointer is below initialized in the
126 // Target::do_select_as_default_target() hook so that we do not spend time
127 // building the table if we are not linking ARM objects.
128 //
129 // An alternative is to to process the information in arm-reloc.def in
130 // compilation time and generate a representation of it in PODs only.  That
131 // way we can avoid initialization when the linker starts.
132
133 Arm_reloc_property_table* arm_reloc_property_table = NULL;
134
135 // Instruction template class.  This class is similar to the insn_sequence
136 // struct in bfd/elf32-arm.c.
137
138 class Insn_template
139 {
140  public:
141   // Types of instruction templates.
142   enum Type
143     {
144       THUMB16_TYPE = 1,
145       // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
146       // templates with class-specific semantics.  Currently this is used
147       // only by the Cortex_a8_stub class for handling condition codes in
148       // conditional branches.
149       THUMB16_SPECIAL_TYPE,
150       THUMB32_TYPE,
151       ARM_TYPE,
152       DATA_TYPE
153     };
154
155   // Factory methods to create instruction templates in different formats.
156
157   static const Insn_template
158   thumb16_insn(uint32_t data)
159   { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
160
161   // A Thumb conditional branch, in which the proper condition is inserted
162   // when we build the stub.
163   static const Insn_template
164   thumb16_bcond_insn(uint32_t data)
165   { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
166
167   static const Insn_template
168   thumb32_insn(uint32_t data)
169   { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
170
171   static const Insn_template
172   thumb32_b_insn(uint32_t data, int reloc_addend)
173   {
174     return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
175                          reloc_addend);
176   }
177
178   static const Insn_template
179   arm_insn(uint32_t data)
180   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
181
182   static const Insn_template
183   arm_rel_insn(unsigned data, int reloc_addend)
184   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
185
186   static const Insn_template
187   data_word(unsigned data, unsigned int r_type, int reloc_addend)
188   { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
189
190   // Accessors.  This class is used for read-only objects so no modifiers
191   // are provided.
192
193   uint32_t
194   data() const
195   { return this->data_; }
196
197   // Return the instruction sequence type of this.
198   Type
199   type() const
200   { return this->type_; }
201
202   // Return the ARM relocation type of this.
203   unsigned int
204   r_type() const
205   { return this->r_type_; }
206
207   int32_t
208   reloc_addend() const
209   { return this->reloc_addend_; }
210
211   // Return size of instruction template in bytes.
212   size_t
213   size() const;
214
215   // Return byte-alignment of instruction template.
216   unsigned
217   alignment() const;
218
219  private:
220   // We make the constructor private to ensure that only the factory
221   // methods are used.
222   inline
223   Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
224     : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
225   { }
226
227   // Instruction specific data.  This is used to store information like
228   // some of the instruction bits.
229   uint32_t data_;
230   // Instruction template type.
231   Type type_;
232   // Relocation type if there is a relocation or R_ARM_NONE otherwise.
233   unsigned int r_type_;
234   // Relocation addend.
235   int32_t reloc_addend_;
236 };
237
238 // Macro for generating code to stub types. One entry per long/short
239 // branch stub
240
241 #define DEF_STUBS \
242   DEF_STUB(long_branch_any_any) \
243   DEF_STUB(long_branch_v4t_arm_thumb) \
244   DEF_STUB(long_branch_thumb_only) \
245   DEF_STUB(long_branch_v4t_thumb_thumb) \
246   DEF_STUB(long_branch_v4t_thumb_arm) \
247   DEF_STUB(short_branch_v4t_thumb_arm) \
248   DEF_STUB(long_branch_any_arm_pic) \
249   DEF_STUB(long_branch_any_thumb_pic) \
250   DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
251   DEF_STUB(long_branch_v4t_arm_thumb_pic) \
252   DEF_STUB(long_branch_v4t_thumb_arm_pic) \
253   DEF_STUB(long_branch_thumb_only_pic) \
254   DEF_STUB(a8_veneer_b_cond) \
255   DEF_STUB(a8_veneer_b) \
256   DEF_STUB(a8_veneer_bl) \
257   DEF_STUB(a8_veneer_blx) \
258   DEF_STUB(v4_veneer_bx)
259
260 // Stub types.
261
262 #define DEF_STUB(x) arm_stub_##x,
263 typedef enum
264   {
265     arm_stub_none,
266     DEF_STUBS
267
268     // First reloc stub type.
269     arm_stub_reloc_first = arm_stub_long_branch_any_any,
270     // Last  reloc stub type.
271     arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
272
273     // First Cortex-A8 stub type.
274     arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
275     // Last Cortex-A8 stub type.
276     arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
277
278     // Last stub type.
279     arm_stub_type_last = arm_stub_v4_veneer_bx
280   } Stub_type;
281 #undef DEF_STUB
282
283 // Stub template class.  Templates are meant to be read-only objects.
284 // A stub template for a stub type contains all read-only attributes
285 // common to all stubs of the same type.
286
287 class Stub_template
288 {
289  public:
290   Stub_template(Stub_type, const Insn_template*, size_t);
291
292   ~Stub_template()
293   { }
294
295   // Return stub type.
296   Stub_type
297   type() const
298   { return this->type_; }
299
300   // Return an array of instruction templates.
301   const Insn_template*
302   insns() const
303   { return this->insns_; }
304
305   // Return size of template in number of instructions.
306   size_t
307   insn_count() const
308   { return this->insn_count_; }
309
310   // Return size of template in bytes.
311   size_t
312   size() const
313   { return this->size_; }
314
315   // Return alignment of the stub template.
316   unsigned
317   alignment() const
318   { return this->alignment_; }
319
320   // Return whether entry point is in thumb mode.
321   bool
322   entry_in_thumb_mode() const
323   { return this->entry_in_thumb_mode_; }
324
325   // Return number of relocations in this template.
326   size_t
327   reloc_count() const
328   { return this->relocs_.size(); }
329
330   // Return index of the I-th instruction with relocation.
331   size_t
332   reloc_insn_index(size_t i) const
333   {
334     gold_assert(i < this->relocs_.size());
335     return this->relocs_[i].first;
336   }
337
338   // Return the offset of the I-th instruction with relocation from the
339   // beginning of the stub.
340   section_size_type
341   reloc_offset(size_t i) const
342   {
343     gold_assert(i < this->relocs_.size());
344     return this->relocs_[i].second;
345   }
346
347  private:
348   // This contains information about an instruction template with a relocation
349   // and its offset from start of stub.
350   typedef std::pair<size_t, section_size_type> Reloc;
351
352   // A Stub_template may not be copied.  We want to share templates as much
353   // as possible.
354   Stub_template(const Stub_template&);
355   Stub_template& operator=(const Stub_template&);
356
357   // Stub type.
358   Stub_type type_;
359   // Points to an array of Insn_templates.
360   const Insn_template* insns_;
361   // Number of Insn_templates in insns_[].
362   size_t insn_count_;
363   // Size of templated instructions in bytes.
364   size_t size_;
365   // Alignment of templated instructions.
366   unsigned alignment_;
367   // Flag to indicate if entry is in thumb mode.
368   bool entry_in_thumb_mode_;
369   // A table of reloc instruction indices and offsets.  We can find these by
370   // looking at the instruction templates but we pre-compute and then stash
371   // them here for speed.
372   std::vector<Reloc> relocs_;
373 };
374
375 //
376 // A class for code stubs.  This is a base class for different type of
377 // stubs used in the ARM target.
378 //
379
380 class Stub
381 {
382  private:
383   static const section_offset_type invalid_offset =
384     static_cast<section_offset_type>(-1);
385
386  public:
387   Stub(const Stub_template* stub_template)
388     : stub_template_(stub_template), offset_(invalid_offset)
389   { }
390
391   virtual
392    ~Stub()
393   { }
394
395   // Return the stub template.
396   const Stub_template*
397   stub_template() const
398   { return this->stub_template_; }
399
400   // Return offset of code stub from beginning of its containing stub table.
401   section_offset_type
402   offset() const
403   {
404     gold_assert(this->offset_ != invalid_offset);
405     return this->offset_;
406   }
407
408   // Set offset of code stub from beginning of its containing stub table.
409   void
410   set_offset(section_offset_type offset)
411   { this->offset_ = offset; }
412
413   // Return the relocation target address of the i-th relocation in the
414   // stub.  This must be defined in a child class.
415   Arm_address
416   reloc_target(size_t i)
417   { return this->do_reloc_target(i); }
418
419   // Write a stub at output VIEW.  BIG_ENDIAN select how a stub is written.
420   void
421   write(unsigned char* view, section_size_type view_size, bool big_endian)
422   { this->do_write(view, view_size, big_endian); }
423
424   // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
425   // for the i-th instruction.
426   uint16_t
427   thumb16_special(size_t i)
428   { return this->do_thumb16_special(i); }
429
430  protected:
431   // This must be defined in the child class.
432   virtual Arm_address
433   do_reloc_target(size_t) = 0;
434
435   // This may be overridden in the child class.
436   virtual void
437   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
438   {
439     if (big_endian)
440       this->do_fixed_endian_write<true>(view, view_size);
441     else
442       this->do_fixed_endian_write<false>(view, view_size);
443   }
444
445   // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
446   // instruction template.
447   virtual uint16_t
448   do_thumb16_special(size_t)
449   { gold_unreachable(); }
450
451  private:
452   // A template to implement do_write.
453   template<bool big_endian>
454   void inline
455   do_fixed_endian_write(unsigned char*, section_size_type);
456
457   // Its template.
458   const Stub_template* stub_template_;
459   // Offset within the section of containing this stub.
460   section_offset_type offset_;
461 };
462
463 // Reloc stub class.  These are stubs we use to fix up relocation because
464 // of limited branch ranges.
465
466 class Reloc_stub : public Stub
467 {
468  public:
469   static const unsigned int invalid_index = static_cast<unsigned int>(-1);
470   // We assume we never jump to this address.
471   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
472
473   // Return destination address.
474   Arm_address
475   destination_address() const
476   {
477     gold_assert(this->destination_address_ != this->invalid_address);
478     return this->destination_address_;
479   }
480
481   // Set destination address.
482   void
483   set_destination_address(Arm_address address)
484   {
485     gold_assert(address != this->invalid_address);
486     this->destination_address_ = address;
487   }
488
489   // Reset destination address.
490   void
491   reset_destination_address()
492   { this->destination_address_ = this->invalid_address; }
493
494   // Determine stub type for a branch of a relocation of R_TYPE going
495   // from BRANCH_ADDRESS to BRANCH_TARGET.  If TARGET_IS_THUMB is set,
496   // the branch target is a thumb instruction.  TARGET is used for look
497   // up ARM-specific linker settings.
498   static Stub_type
499   stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
500                       Arm_address branch_target, bool target_is_thumb);
501
502   // Reloc_stub key.  A key is logically a triplet of a stub type, a symbol
503   // and an addend.  Since we treat global and local symbol differently, we
504   // use a Symbol object for a global symbol and a object-index pair for
505   // a local symbol.
506   class Key
507   {
508    public:
509     // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
510     // R_SYM.  Otherwise, this is a local symbol and RELOBJ must non-NULL
511     // and R_SYM must not be invalid_index.
512     Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
513         unsigned int r_sym, int32_t addend)
514       : stub_type_(stub_type), addend_(addend)
515     {
516       if (symbol != NULL)
517         {
518           this->r_sym_ = Reloc_stub::invalid_index;
519           this->u_.symbol = symbol;
520         }
521       else
522         {
523           gold_assert(relobj != NULL && r_sym != invalid_index);
524           this->r_sym_ = r_sym;
525           this->u_.relobj = relobj;
526         }
527     }
528
529     ~Key()
530     { }
531
532     // Accessors: Keys are meant to be read-only object so no modifiers are
533     // provided.
534
535     // Return stub type.
536     Stub_type
537     stub_type() const
538     { return this->stub_type_; }
539
540     // Return the local symbol index or invalid_index.
541     unsigned int
542     r_sym() const
543     { return this->r_sym_; }
544
545     // Return the symbol if there is one.
546     const Symbol*
547     symbol() const
548     { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
549
550     // Return the relobj if there is one.
551     const Relobj*
552     relobj() const
553     { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
554
555     // Whether this equals to another key k.
556     bool
557     eq(const Key& k) const
558     {
559       return ((this->stub_type_ == k.stub_type_)
560               && (this->r_sym_ == k.r_sym_)
561               && ((this->r_sym_ != Reloc_stub::invalid_index)
562                   ? (this->u_.relobj == k.u_.relobj)
563                   : (this->u_.symbol == k.u_.symbol))
564               && (this->addend_ == k.addend_));
565     }
566
567     // Return a hash value.
568     size_t
569     hash_value() const
570     {
571       return (this->stub_type_
572               ^ this->r_sym_
573               ^ gold::string_hash<char>(
574                     (this->r_sym_ != Reloc_stub::invalid_index)
575                     ? this->u_.relobj->name().c_str()
576                     : this->u_.symbol->name())
577               ^ this->addend_);
578     }
579
580     // Functors for STL associative containers.
581     struct hash
582     {
583       size_t
584       operator()(const Key& k) const
585       { return k.hash_value(); }
586     };
587
588     struct equal_to
589     {
590       bool
591       operator()(const Key& k1, const Key& k2) const
592       { return k1.eq(k2); }
593     };
594
595     // Name of key.  This is mainly for debugging.
596     std::string
597     name() const;
598
599    private:
600     // Stub type.
601     Stub_type stub_type_;
602     // If this is a local symbol, this is the index in the defining object.
603     // Otherwise, it is invalid_index for a global symbol.
604     unsigned int r_sym_;
605     // If r_sym_ is an invalid index, this points to a global symbol.
606     // Otherwise, it points to a relobj.  We used the unsized and target
607     // independent Symbol and Relobj classes instead of Sized_symbol<32> and
608     // Arm_relobj, in order to avoid making the stub class a template
609     // as most of the stub machinery is endianness-neutral.  However, it
610     // may require a bit of casting done by users of this class.
611     union
612     {
613       const Symbol* symbol;
614       const Relobj* relobj;
615     } u_;
616     // Addend associated with a reloc.
617     int32_t addend_;
618   };
619
620  protected:
621   // Reloc_stubs are created via a stub factory.  So these are protected.
622   Reloc_stub(const Stub_template* stub_template)
623     : Stub(stub_template), destination_address_(invalid_address)
624   { }
625
626   ~Reloc_stub()
627   { }
628
629   friend class Stub_factory;
630
631   // Return the relocation target address of the i-th relocation in the
632   // stub.
633   Arm_address
634   do_reloc_target(size_t i)
635   {
636     // All reloc stub have only one relocation.
637     gold_assert(i == 0);
638     return this->destination_address_;
639   }
640
641  private:
642   // Address of destination.
643   Arm_address destination_address_;
644 };
645
646 // Cortex-A8 stub class.  We need a Cortex-A8 stub to redirect any 32-bit
647 // THUMB branch that meets the following conditions:
648 //
649 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
650 //    branch address is 0xffe.
651 // 2. The branch target address is in the same page as the first word of the
652 //    branch.
653 // 3. The branch follows a 32-bit instruction which is not a branch.
654 //
655 // To do the fix up, we need to store the address of the branch instruction
656 // and its target at least.  We also need to store the original branch
657 // instruction bits for the condition code in a conditional branch.  The
658 // condition code is used in a special instruction template.  We also want
659 // to identify input sections needing Cortex-A8 workaround quickly.  We store
660 // extra information about object and section index of the code section
661 // containing a branch being fixed up.  The information is used to mark
662 // the code section when we finalize the Cortex-A8 stubs.
663 //
664
665 class Cortex_a8_stub : public Stub
666 {
667  public:
668   ~Cortex_a8_stub()
669   { }
670
671   // Return the object of the code section containing the branch being fixed
672   // up.
673   Relobj*
674   relobj() const
675   { return this->relobj_; }
676
677   // Return the section index of the code section containing the branch being
678   // fixed up.
679   unsigned int
680   shndx() const
681   { return this->shndx_; }
682
683   // Return the source address of stub.  This is the address of the original
684   // branch instruction.  LSB is 1 always set to indicate that it is a THUMB
685   // instruction.
686   Arm_address
687   source_address() const
688   { return this->source_address_; }
689
690   // Return the destination address of the stub.  This is the branch taken
691   // address of the original branch instruction.  LSB is 1 if it is a THUMB
692   // instruction address.
693   Arm_address
694   destination_address() const
695   { return this->destination_address_; }
696
697   // Return the instruction being fixed up.
698   uint32_t
699   original_insn() const
700   { return this->original_insn_; }
701
702  protected:
703   // Cortex_a8_stubs are created via a stub factory.  So these are protected.
704   Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
705                  unsigned int shndx, Arm_address source_address,
706                  Arm_address destination_address, uint32_t original_insn)
707     : Stub(stub_template), relobj_(relobj), shndx_(shndx),
708       source_address_(source_address | 1U),
709       destination_address_(destination_address),
710       original_insn_(original_insn)
711   { }
712
713   friend class Stub_factory;
714
715   // Return the relocation target address of the i-th relocation in the
716   // stub.
717   Arm_address
718   do_reloc_target(size_t i)
719   {
720     if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
721       {
722         // The conditional branch veneer has two relocations.
723         gold_assert(i < 2);
724         return i == 0 ? this->source_address_ + 4 : this->destination_address_;
725       }
726     else
727       {
728         // All other Cortex-A8 stubs have only one relocation.
729         gold_assert(i == 0);
730         return this->destination_address_;
731       }
732   }
733
734   // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
735   uint16_t
736   do_thumb16_special(size_t);
737
738  private:
739   // Object of the code section containing the branch being fixed up.
740   Relobj* relobj_;
741   // Section index of the code section containing the branch begin fixed up.
742   unsigned int shndx_;
743   // Source address of original branch.
744   Arm_address source_address_;
745   // Destination address of the original branch.
746   Arm_address destination_address_;
747   // Original branch instruction.  This is needed for copying the condition
748   // code from a condition branch to its stub.
749   uint32_t original_insn_;
750 };
751
752 // ARMv4 BX Rx branch relocation stub class.
753 class Arm_v4bx_stub : public Stub
754 {
755  public:
756   ~Arm_v4bx_stub()
757   { }
758
759   // Return the associated register.
760   uint32_t
761   reg() const
762   { return this->reg_; }
763
764  protected:
765   // Arm V4BX stubs are created via a stub factory.  So these are protected.
766   Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
767     : Stub(stub_template), reg_(reg)
768   { }
769
770   friend class Stub_factory;
771
772   // Return the relocation target address of the i-th relocation in the
773   // stub.
774   Arm_address
775   do_reloc_target(size_t)
776   { gold_unreachable(); }
777
778   // This may be overridden in the child class.
779   virtual void
780   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
781   {
782     if (big_endian)
783       this->do_fixed_endian_v4bx_write<true>(view, view_size);
784     else
785       this->do_fixed_endian_v4bx_write<false>(view, view_size);
786   }
787
788  private:
789   // A template to implement do_write.
790   template<bool big_endian>
791   void inline
792   do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
793   {
794     const Insn_template* insns = this->stub_template()->insns();
795     elfcpp::Swap<32, big_endian>::writeval(view,
796                                            (insns[0].data()
797                                            + (this->reg_ << 16)));
798     view += insns[0].size();
799     elfcpp::Swap<32, big_endian>::writeval(view,
800                                            (insns[1].data() + this->reg_));
801     view += insns[1].size();
802     elfcpp::Swap<32, big_endian>::writeval(view,
803                                            (insns[2].data() + this->reg_));
804   }
805
806   // A register index (r0-r14), which is associated with the stub.
807   uint32_t reg_;
808 };
809
810 // Stub factory class.
811
812 class Stub_factory
813 {
814  public:
815   // Return the unique instance of this class.
816   static const Stub_factory&
817   get_instance()
818   {
819     static Stub_factory singleton;
820     return singleton;
821   }
822
823   // Make a relocation stub.
824   Reloc_stub*
825   make_reloc_stub(Stub_type stub_type) const
826   {
827     gold_assert(stub_type >= arm_stub_reloc_first
828                 && stub_type <= arm_stub_reloc_last);
829     return new Reloc_stub(this->stub_templates_[stub_type]);
830   }
831
832   // Make a Cortex-A8 stub.
833   Cortex_a8_stub*
834   make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
835                       Arm_address source, Arm_address destination,
836                       uint32_t original_insn) const
837   {
838     gold_assert(stub_type >= arm_stub_cortex_a8_first
839                 && stub_type <= arm_stub_cortex_a8_last);
840     return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
841                               source, destination, original_insn);
842   }
843
844   // Make an ARM V4BX relocation stub.
845   // This method creates a stub from the arm_stub_v4_veneer_bx template only.
846   Arm_v4bx_stub*
847   make_arm_v4bx_stub(uint32_t reg) const
848   {
849     gold_assert(reg < 0xf);
850     return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851                              reg);
852   }
853
854  private:
855   // Constructor and destructor are protected since we only return a single
856   // instance created in Stub_factory::get_instance().
857
858   Stub_factory();
859
860   // A Stub_factory may not be copied since it is a singleton.
861   Stub_factory(const Stub_factory&);
862   Stub_factory& operator=(Stub_factory&);
863
864   // Stub templates.  These are initialized in the constructor.
865   const Stub_template* stub_templates_[arm_stub_type_last+1];
866 };
867
868 // A class to hold stubs for the ARM target.
869
870 template<bool big_endian>
871 class Stub_table : public Output_data
872 {
873  public:
874   Stub_table(Arm_input_section<big_endian>* owner)
875     : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
876       reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
877       prev_data_size_(0), prev_addralign_(1)
878   { }
879
880   ~Stub_table()
881   { }
882
883   // Owner of this stub table.
884   Arm_input_section<big_endian>*
885   owner() const
886   { return this->owner_; }
887
888   // Whether this stub table is empty.
889   bool
890   empty() const
891   {
892     return (this->reloc_stubs_.empty()
893             && this->cortex_a8_stubs_.empty()
894             && this->arm_v4bx_stubs_.empty());
895   }
896
897   // Return the current data size.
898   off_t
899   current_data_size() const
900   { return this->current_data_size_for_child(); }
901
902   // Add a STUB using KEY.  The caller is responsible for avoiding addition
903   // if a STUB with the same key has already been added.
904   void
905   add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
906   {
907     const Stub_template* stub_template = stub->stub_template();
908     gold_assert(stub_template->type() == key.stub_type());
909     this->reloc_stubs_[key] = stub;
910
911     // Assign stub offset early.  We can do this because we never remove
912     // reloc stubs and they are in the beginning of the stub table.
913     uint64_t align = stub_template->alignment();
914     this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
915     stub->set_offset(this->reloc_stubs_size_);
916     this->reloc_stubs_size_ += stub_template->size();
917     this->reloc_stubs_addralign_ =
918       std::max(this->reloc_stubs_addralign_, align);
919   }
920
921   // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
922   // The caller is responsible for avoiding addition if a STUB with the same
923   // address has already been added.
924   void
925   add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
926   {
927     std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
928     this->cortex_a8_stubs_.insert(value);
929   }
930
931   // Add an ARM V4BX relocation stub. A register index will be retrieved
932   // from the stub.
933   void
934   add_arm_v4bx_stub(Arm_v4bx_stub* stub)
935   {
936     gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
937     this->arm_v4bx_stubs_[stub->reg()] = stub;
938   }
939
940   // Remove all Cortex-A8 stubs.
941   void
942   remove_all_cortex_a8_stubs();
943
944   // Look up a relocation stub using KEY.  Return NULL if there is none.
945   Reloc_stub*
946   find_reloc_stub(const Reloc_stub::Key& key) const
947   {
948     typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
949     return (p != this->reloc_stubs_.end()) ? p->second : NULL;
950   }
951
952   // Look up an arm v4bx relocation stub using the register index.
953   // Return NULL if there is none.
954   Arm_v4bx_stub*
955   find_arm_v4bx_stub(const uint32_t reg) const
956   {
957     gold_assert(reg < 0xf);
958     return this->arm_v4bx_stubs_[reg];
959   }
960
961   // Relocate stubs in this stub table.
962   void
963   relocate_stubs(const Relocate_info<32, big_endian>*,
964                  Target_arm<big_endian>*, Output_section*,
965                  unsigned char*, Arm_address, section_size_type);
966
967   // Update data size and alignment at the end of a relaxation pass.  Return
968   // true if either data size or alignment is different from that of the
969   // previous relaxation pass.
970   bool
971   update_data_size_and_addralign();
972
973   // Finalize stubs.  Set the offsets of all stubs and mark input sections
974   // needing the Cortex-A8 workaround.
975   void
976   finalize_stubs();
977
978   // Apply Cortex-A8 workaround to an address range.
979   void
980   apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
981                                               unsigned char*, Arm_address,
982                                               section_size_type);
983
984  protected:
985   // Write out section contents.
986   void
987   do_write(Output_file*);
988
989   // Return the required alignment.
990   uint64_t
991   do_addralign() const
992   { return this->prev_addralign_; }
993
994   // Reset address and file offset.
995   void
996   do_reset_address_and_file_offset()
997   { this->set_current_data_size_for_child(this->prev_data_size_); }
998
999   // Set final data size.
1000   void
1001   set_final_data_size()
1002   { this->set_data_size(this->current_data_size()); }
1003
1004  private:
1005   // Relocate one stub.
1006   void
1007   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1008                 Target_arm<big_endian>*, Output_section*,
1009                 unsigned char*, Arm_address, section_size_type);
1010
1011   // Unordered map of relocation stubs.
1012   typedef
1013     Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1014                   Reloc_stub::Key::equal_to>
1015     Reloc_stub_map;
1016
1017   // List of Cortex-A8 stubs ordered by addresses of branches being
1018   // fixed up in output.
1019   typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1020   // List of Arm V4BX relocation stubs ordered by associated registers.
1021   typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1022
1023   // Owner of this stub table.
1024   Arm_input_section<big_endian>* owner_;
1025   // The relocation stubs.
1026   Reloc_stub_map reloc_stubs_;
1027   // Size of reloc stubs.
1028   off_t reloc_stubs_size_;
1029   // Maximum address alignment of reloc stubs.
1030   uint64_t reloc_stubs_addralign_;
1031   // The cortex_a8_stubs.
1032   Cortex_a8_stub_list cortex_a8_stubs_;
1033   // The Arm V4BX relocation stubs.
1034   Arm_v4bx_stub_list arm_v4bx_stubs_;
1035   // data size of this in the previous pass.
1036   off_t prev_data_size_;
1037   // address alignment of this in the previous pass.
1038   uint64_t prev_addralign_;
1039 };
1040
1041 // Arm_exidx_cantunwind class.  This represents an EXIDX_CANTUNWIND entry
1042 // we add to the end of an EXIDX input section that goes into the output.
1043
1044 class Arm_exidx_cantunwind : public Output_section_data
1045 {
1046  public:
1047   Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1048     : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1049   { }
1050
1051   // Return the object containing the section pointed by this.
1052   Relobj*
1053   relobj() const
1054   { return this->relobj_; }
1055
1056   // Return the section index of the section pointed by this.
1057   unsigned int
1058   shndx() const
1059   { return this->shndx_; }
1060
1061  protected:
1062   void
1063   do_write(Output_file* of)
1064   {
1065     if (parameters->target().is_big_endian())
1066       this->do_fixed_endian_write<true>(of);
1067     else
1068       this->do_fixed_endian_write<false>(of);
1069   }
1070
1071   // Write to a map file.
1072   void
1073   do_print_to_mapfile(Mapfile* mapfile) const
1074   { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1075
1076  private:
1077   // Implement do_write for a given endianness.
1078   template<bool big_endian>
1079   void inline
1080   do_fixed_endian_write(Output_file*);
1081
1082   // The object containing the section pointed by this.
1083   Relobj* relobj_;
1084   // The section index of the section pointed by this.
1085   unsigned int shndx_;
1086 };
1087
1088 // During EXIDX coverage fix-up, we compact an EXIDX section.  The
1089 // Offset map is used to map input section offset within the EXIDX section
1090 // to the output offset from the start of this EXIDX section.
1091
1092 typedef std::map<section_offset_type, section_offset_type>
1093         Arm_exidx_section_offset_map;
1094
1095 // Arm_exidx_merged_section class.  This represents an EXIDX input section
1096 // with some of its entries merged.
1097
1098 class Arm_exidx_merged_section : public Output_relaxed_input_section
1099 {
1100  public:
1101   // Constructor for Arm_exidx_merged_section.
1102   // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1103   // SECTION_OFFSET_MAP points to a section offset map describing how
1104   // parts of the input section are mapped to output.  DELETED_BYTES is
1105   // the number of bytes deleted from the EXIDX input section.
1106   Arm_exidx_merged_section(
1107       const Arm_exidx_input_section& exidx_input_section,
1108       const Arm_exidx_section_offset_map& section_offset_map,
1109       uint32_t deleted_bytes);
1110
1111   // Build output contents.
1112   void
1113   build_contents(const unsigned char*, section_size_type);
1114
1115   // Return the original EXIDX input section.
1116   const Arm_exidx_input_section&
1117   exidx_input_section() const
1118   { return this->exidx_input_section_; }
1119
1120   // Return the section offset map.
1121   const Arm_exidx_section_offset_map&
1122   section_offset_map() const
1123   { return this->section_offset_map_; }
1124
1125  protected:
1126   // Write merged section into file OF.
1127   void
1128   do_write(Output_file* of);
1129
1130   bool
1131   do_output_offset(const Relobj*, unsigned int, section_offset_type,
1132                   section_offset_type*) const;
1133
1134  private:
1135   // Original EXIDX input section.
1136   const Arm_exidx_input_section& exidx_input_section_;
1137   // Section offset map.
1138   const Arm_exidx_section_offset_map& section_offset_map_;
1139   // Merged section contents.  We need to keep build the merged section
1140   // and save it here to avoid accessing the original EXIDX section when
1141   // we cannot lock the sections' object.
1142   unsigned char* section_contents_;
1143 };
1144
1145 // A class to wrap an ordinary input section containing executable code.
1146
1147 template<bool big_endian>
1148 class Arm_input_section : public Output_relaxed_input_section
1149 {
1150  public:
1151   Arm_input_section(Relobj* relobj, unsigned int shndx)
1152     : Output_relaxed_input_section(relobj, shndx, 1),
1153       original_addralign_(1), original_size_(0), stub_table_(NULL),
1154       original_contents_(NULL)
1155   { }
1156
1157   ~Arm_input_section()
1158   { delete[] this->original_contents_; }
1159
1160   // Initialize.
1161   void
1162   init();
1163
1164   // Whether this is a stub table owner.
1165   bool
1166   is_stub_table_owner() const
1167   { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1168
1169   // Return the stub table.
1170   Stub_table<big_endian>*
1171   stub_table() const
1172   { return this->stub_table_; }
1173
1174   // Set the stub_table.
1175   void
1176   set_stub_table(Stub_table<big_endian>* stub_table)
1177   { this->stub_table_ = stub_table; }
1178
1179   // Downcast a base pointer to an Arm_input_section pointer.  This is
1180   // not type-safe but we only use Arm_input_section not the base class.
1181   static Arm_input_section<big_endian>*
1182   as_arm_input_section(Output_relaxed_input_section* poris)
1183   { return static_cast<Arm_input_section<big_endian>*>(poris); }
1184
1185   // Return the original size of the section.
1186   uint32_t
1187   original_size() const
1188   { return this->original_size_; }
1189
1190  protected:
1191   // Write data to output file.
1192   void
1193   do_write(Output_file*);
1194
1195   // Return required alignment of this.
1196   uint64_t
1197   do_addralign() const
1198   {
1199     if (this->is_stub_table_owner())
1200       return std::max(this->stub_table_->addralign(),
1201                       static_cast<uint64_t>(this->original_addralign_));
1202     else
1203       return this->original_addralign_;
1204   }
1205
1206   // Finalize data size.
1207   void
1208   set_final_data_size();
1209
1210   // Reset address and file offset.
1211   void
1212   do_reset_address_and_file_offset();
1213
1214   // Output offset.
1215   bool
1216   do_output_offset(const Relobj* object, unsigned int shndx,
1217                    section_offset_type offset,
1218                    section_offset_type* poutput) const
1219   {
1220     if ((object == this->relobj())
1221         && (shndx == this->shndx())
1222         && (offset >= 0)
1223         && (offset <=
1224             convert_types<section_offset_type, uint32_t>(this->original_size_)))
1225       {
1226         *poutput = offset;
1227         return true;
1228       }
1229     else
1230       return false;
1231   }
1232
1233  private:
1234   // Copying is not allowed.
1235   Arm_input_section(const Arm_input_section&);
1236   Arm_input_section& operator=(const Arm_input_section&);
1237
1238   // Address alignment of the original input section.
1239   uint32_t original_addralign_;
1240   // Section size of the original input section.
1241   uint32_t original_size_;
1242   // Stub table.
1243   Stub_table<big_endian>* stub_table_;
1244   // Original section contents.  We have to make a copy here since the file
1245   // containing the original section may not be locked when we need to access
1246   // the contents.
1247   unsigned char* original_contents_;
1248 };
1249
1250 // Arm_exidx_fixup class.  This is used to define a number of methods
1251 // and keep states for fixing up EXIDX coverage.
1252
1253 class Arm_exidx_fixup
1254 {
1255  public:
1256   Arm_exidx_fixup(Output_section* exidx_output_section,
1257                   bool merge_exidx_entries = true)
1258     : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1259       last_inlined_entry_(0), last_input_section_(NULL),
1260       section_offset_map_(NULL), first_output_text_section_(NULL),
1261       merge_exidx_entries_(merge_exidx_entries)
1262   { }
1263
1264   ~Arm_exidx_fixup()
1265   { delete this->section_offset_map_; }
1266
1267   // Process an EXIDX section for entry merging.  SECTION_CONTENTS points
1268   // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1269   // number of bytes to be deleted in output.  If parts of the input EXIDX
1270   // section are merged a heap allocated Arm_exidx_section_offset_map is store
1271   // in the located PSECTION_OFFSET_MAP.   The caller owns the map and is
1272   // responsible for releasing it.
1273   template<bool big_endian>
1274   uint32_t
1275   process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1276                         const unsigned char* section_contents,
1277                         section_size_type section_size,
1278                         Arm_exidx_section_offset_map** psection_offset_map);
1279
1280   // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1281   // input section, if there is not one already.
1282   void
1283   add_exidx_cantunwind_as_needed();
1284
1285   // Return the output section for the text section which is linked to the
1286   // first exidx input in output.
1287   Output_section*
1288   first_output_text_section() const
1289   { return this->first_output_text_section_; }
1290
1291  private:
1292   // Copying is not allowed.
1293   Arm_exidx_fixup(const Arm_exidx_fixup&);
1294   Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1295
1296   // Type of EXIDX unwind entry.
1297   enum Unwind_type
1298   {
1299     // No type.
1300     UT_NONE,
1301     // EXIDX_CANTUNWIND.
1302     UT_EXIDX_CANTUNWIND,
1303     // Inlined entry.
1304     UT_INLINED_ENTRY,
1305     // Normal entry.
1306     UT_NORMAL_ENTRY,
1307   };
1308
1309   // Process an EXIDX entry.  We only care about the second word of the
1310   // entry.  Return true if the entry can be deleted.
1311   bool
1312   process_exidx_entry(uint32_t second_word);
1313
1314   // Update the current section offset map during EXIDX section fix-up.
1315   // If there is no map, create one.  INPUT_OFFSET is the offset of a
1316   // reference point, DELETED_BYTES is the number of deleted by in the
1317   // section so far.  If DELETE_ENTRY is true, the reference point and
1318   // all offsets after the previous reference point are discarded.
1319   void
1320   update_offset_map(section_offset_type input_offset,
1321                     section_size_type deleted_bytes, bool delete_entry);
1322
1323   // EXIDX output section.
1324   Output_section* exidx_output_section_;
1325   // Unwind type of the last EXIDX entry processed.
1326   Unwind_type last_unwind_type_;
1327   // Last seen inlined EXIDX entry.
1328   uint32_t last_inlined_entry_;
1329   // Last processed EXIDX input section.
1330   const Arm_exidx_input_section* last_input_section_;
1331   // Section offset map created in process_exidx_section.
1332   Arm_exidx_section_offset_map* section_offset_map_;
1333   // Output section for the text section which is linked to the first exidx
1334   // input in output.
1335   Output_section* first_output_text_section_;
1336
1337   bool merge_exidx_entries_;
1338 };
1339
1340 // Arm output section class.  This is defined mainly to add a number of
1341 // stub generation methods.
1342
1343 template<bool big_endian>
1344 class Arm_output_section : public Output_section
1345 {
1346  public:
1347   typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1348
1349   // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1350   Arm_output_section(const char* name, elfcpp::Elf_Word type,
1351                      elfcpp::Elf_Xword flags)
1352     : Output_section(name, type,
1353                      (type == elfcpp::SHT_ARM_EXIDX
1354                       ? flags | elfcpp::SHF_LINK_ORDER
1355                       : flags))
1356   {
1357     if (type == elfcpp::SHT_ARM_EXIDX)
1358       this->set_always_keeps_input_sections();
1359   }
1360
1361   ~Arm_output_section()
1362   { }
1363
1364   // Group input sections for stub generation.
1365   void
1366   group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1367
1368   // Downcast a base pointer to an Arm_output_section pointer.  This is
1369   // not type-safe but we only use Arm_output_section not the base class.
1370   static Arm_output_section<big_endian>*
1371   as_arm_output_section(Output_section* os)
1372   { return static_cast<Arm_output_section<big_endian>*>(os); }
1373
1374   // Append all input text sections in this into LIST.
1375   void
1376   append_text_sections_to_list(Text_section_list* list);
1377
1378   // Fix EXIDX coverage of this EXIDX output section.  SORTED_TEXT_SECTION
1379   // is a list of text input sections sorted in ascending order of their
1380   // output addresses.
1381   void
1382   fix_exidx_coverage(Layout* layout,
1383                      const Text_section_list& sorted_text_section,
1384                      Symbol_table* symtab,
1385                      bool merge_exidx_entries,
1386                      const Task* task);
1387
1388   // Link an EXIDX section into its corresponding text section.
1389   void
1390   set_exidx_section_link();
1391
1392  private:
1393   // For convenience.
1394   typedef Output_section::Input_section Input_section;
1395   typedef Output_section::Input_section_list Input_section_list;
1396
1397   // Create a stub group.
1398   void create_stub_group(Input_section_list::const_iterator,
1399                          Input_section_list::const_iterator,
1400                          Input_section_list::const_iterator,
1401                          Target_arm<big_endian>*,
1402                          std::vector<Output_relaxed_input_section*>*,
1403                          const Task* task);
1404 };
1405
1406 // Arm_exidx_input_section class.  This represents an EXIDX input section.
1407
1408 class Arm_exidx_input_section
1409 {
1410  public:
1411   static const section_offset_type invalid_offset =
1412     static_cast<section_offset_type>(-1);
1413
1414   Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1415                           unsigned int link, uint32_t size,
1416                           uint32_t addralign, uint32_t text_size)
1417     : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1418       addralign_(addralign), text_size_(text_size), has_errors_(false)
1419   { }
1420
1421   ~Arm_exidx_input_section()
1422   { }
1423
1424   // Accessors:  This is a read-only class.
1425
1426   // Return the object containing this EXIDX input section.
1427   Relobj*
1428   relobj() const
1429   { return this->relobj_; }
1430
1431   // Return the section index of this EXIDX input section.
1432   unsigned int
1433   shndx() const
1434   { return this->shndx_; }
1435
1436   // Return the section index of linked text section in the same object.
1437   unsigned int
1438   link() const
1439   { return this->link_; }
1440
1441   // Return size of the EXIDX input section.
1442   uint32_t
1443   size() const
1444   { return this->size_; }
1445
1446   // Return address alignment of EXIDX input section.
1447   uint32_t
1448   addralign() const
1449   { return this->addralign_; }
1450
1451   // Return size of the associated text input section.
1452   uint32_t
1453   text_size() const
1454   { return this->text_size_; }
1455
1456   // Whether there are any errors in the EXIDX input section.
1457   bool
1458   has_errors() const
1459   { return this->has_errors_; }
1460
1461   // Set has-errors flag.
1462   void
1463   set_has_errors()
1464   { this->has_errors_ = true; }
1465
1466  private:
1467   // Object containing this.
1468   Relobj* relobj_;
1469   // Section index of this.
1470   unsigned int shndx_;
1471   // text section linked to this in the same object.
1472   unsigned int link_;
1473   // Size of this.  For ARM 32-bit is sufficient.
1474   uint32_t size_;
1475   // Address alignment of this.  For ARM 32-bit is sufficient.
1476   uint32_t addralign_;
1477   // Size of associated text section.
1478   uint32_t text_size_;
1479   // Whether this has any errors.
1480   bool has_errors_;
1481 };
1482
1483 // Arm_relobj class.
1484
1485 template<bool big_endian>
1486 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1487 {
1488  public:
1489   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1490
1491   Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1492              const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1493     : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1494       stub_tables_(), local_symbol_is_thumb_function_(),
1495       attributes_section_data_(NULL), mapping_symbols_info_(),
1496       section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1497       output_local_symbol_count_needs_update_(false),
1498       merge_flags_and_attributes_(true)
1499   { }
1500
1501   ~Arm_relobj()
1502   { delete this->attributes_section_data_; }
1503
1504   // Return the stub table of the SHNDX-th section if there is one.
1505   Stub_table<big_endian>*
1506   stub_table(unsigned int shndx) const
1507   {
1508     gold_assert(shndx < this->stub_tables_.size());
1509     return this->stub_tables_[shndx];
1510   }
1511
1512   // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1513   void
1514   set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1515   {
1516     gold_assert(shndx < this->stub_tables_.size());
1517     this->stub_tables_[shndx] = stub_table;
1518   }
1519
1520   // Whether a local symbol is a THUMB function.  R_SYM is the symbol table
1521   // index.  This is only valid after do_count_local_symbol is called.
1522   bool
1523   local_symbol_is_thumb_function(unsigned int r_sym) const
1524   {
1525     gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1526     return this->local_symbol_is_thumb_function_[r_sym];
1527   }
1528
1529   // Scan all relocation sections for stub generation.
1530   void
1531   scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1532                           const Layout*);
1533
1534   // Convert regular input section with index SHNDX to a relaxed section.
1535   void
1536   convert_input_section_to_relaxed_section(unsigned shndx)
1537   {
1538     // The stubs have relocations and we need to process them after writing
1539     // out the stubs.  So relocation now must follow section write.
1540     this->set_section_offset(shndx, -1ULL);
1541     this->set_relocs_must_follow_section_writes();
1542   }
1543
1544   // Downcast a base pointer to an Arm_relobj pointer.  This is
1545   // not type-safe but we only use Arm_relobj not the base class.
1546   static Arm_relobj<big_endian>*
1547   as_arm_relobj(Relobj* relobj)
1548   { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1549
1550   // Processor-specific flags in ELF file header.  This is valid only after
1551   // reading symbols.
1552   elfcpp::Elf_Word
1553   processor_specific_flags() const
1554   { return this->processor_specific_flags_; }
1555
1556   // Attribute section data  This is the contents of the .ARM.attribute section
1557   // if there is one.
1558   const Attributes_section_data*
1559   attributes_section_data() const
1560   { return this->attributes_section_data_; }
1561
1562   // Mapping symbol location.
1563   typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1564
1565   // Functor for STL container.
1566   struct Mapping_symbol_position_less
1567   {
1568     bool
1569     operator()(const Mapping_symbol_position& p1,
1570                const Mapping_symbol_position& p2) const
1571     {
1572       return (p1.first < p2.first
1573               || (p1.first == p2.first && p1.second < p2.second));
1574     }
1575   };
1576
1577   // We only care about the first character of a mapping symbol, so
1578   // we only store that instead of the whole symbol name.
1579   typedef std::map<Mapping_symbol_position, char,
1580                    Mapping_symbol_position_less> Mapping_symbols_info;
1581
1582   // Whether a section contains any Cortex-A8 workaround.
1583   bool
1584   section_has_cortex_a8_workaround(unsigned int shndx) const
1585   {
1586     return (this->section_has_cortex_a8_workaround_ != NULL
1587             && (*this->section_has_cortex_a8_workaround_)[shndx]);
1588   }
1589
1590   // Mark a section that has Cortex-A8 workaround.
1591   void
1592   mark_section_for_cortex_a8_workaround(unsigned int shndx)
1593   {
1594     if (this->section_has_cortex_a8_workaround_ == NULL)
1595       this->section_has_cortex_a8_workaround_ =
1596         new std::vector<bool>(this->shnum(), false);
1597     (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1598   }
1599
1600   // Return the EXIDX section of an text section with index SHNDX or NULL
1601   // if the text section has no associated EXIDX section.
1602   const Arm_exidx_input_section*
1603   exidx_input_section_by_link(unsigned int shndx) const
1604   {
1605     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1606     return ((p != this->exidx_section_map_.end()
1607              && p->second->link() == shndx)
1608             ? p->second
1609             : NULL);
1610   }
1611
1612   // Return the EXIDX section with index SHNDX or NULL if there is none.
1613   const Arm_exidx_input_section*
1614   exidx_input_section_by_shndx(unsigned shndx) const
1615   {
1616     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1617     return ((p != this->exidx_section_map_.end()
1618              && p->second->shndx() == shndx)
1619             ? p->second
1620             : NULL);
1621   }
1622
1623   // Whether output local symbol count needs updating.
1624   bool
1625   output_local_symbol_count_needs_update() const
1626   { return this->output_local_symbol_count_needs_update_; }
1627
1628   // Set output_local_symbol_count_needs_update flag to be true.
1629   void
1630   set_output_local_symbol_count_needs_update()
1631   { this->output_local_symbol_count_needs_update_ = true; }
1632
1633   // Update output local symbol count at the end of relaxation.
1634   void
1635   update_output_local_symbol_count();
1636
1637   // Whether we want to merge processor-specific flags and attributes.
1638   bool
1639   merge_flags_and_attributes() const
1640   { return this->merge_flags_and_attributes_; }
1641
1642   // Export list of EXIDX section indices.
1643   void
1644   get_exidx_shndx_list(std::vector<unsigned int>* list) const
1645   {
1646     list->clear();
1647     for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1648          p != this->exidx_section_map_.end();
1649          ++p)
1650       {
1651         if (p->second->shndx() == p->first)
1652           list->push_back(p->first);
1653       }
1654     // Sort list to make result independent of implementation of map.
1655     std::sort(list->begin(), list->end());
1656   }
1657
1658  protected:
1659   // Post constructor setup.
1660   void
1661   do_setup()
1662   {
1663     // Call parent's setup method.
1664     Sized_relobj_file<32, big_endian>::do_setup();
1665
1666     // Initialize look-up tables.
1667     Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1668     this->stub_tables_.swap(empty_stub_table_list);
1669   }
1670
1671   // Count the local symbols.
1672   void
1673   do_count_local_symbols(Stringpool_template<char>*,
1674                          Stringpool_template<char>*);
1675
1676   void
1677   do_relocate_sections(
1678       const Symbol_table* symtab, const Layout* layout,
1679       const unsigned char* pshdrs, Output_file* of,
1680       typename Sized_relobj_file<32, big_endian>::Views* pivews);
1681
1682   // Read the symbol information.
1683   void
1684   do_read_symbols(Read_symbols_data* sd);
1685
1686   // Process relocs for garbage collection.
1687   void
1688   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1689
1690  private:
1691
1692   // Whether a section needs to be scanned for relocation stubs.
1693   bool
1694   section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1695                                     const Relobj::Output_sections&,
1696                                     const Symbol_table*, const unsigned char*);
1697
1698   // Whether a section is a scannable text section.
1699   bool
1700   section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1701                        const Output_section*, const Symbol_table*);
1702
1703   // Whether a section needs to be scanned for the Cortex-A8 erratum.
1704   bool
1705   section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1706                                         unsigned int, Output_section*,
1707                                         const Symbol_table*);
1708
1709   // Scan a section for the Cortex-A8 erratum.
1710   void
1711   scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1712                                      unsigned int, Output_section*,
1713                                      Target_arm<big_endian>*);
1714
1715   // Find the linked text section of an EXIDX section by looking at the
1716   // first relocation of the EXIDX section.  PSHDR points to the section
1717   // headers of a relocation section and PSYMS points to the local symbols.
1718   // PSHNDX points to a location storing the text section index if found.
1719   // Return whether we can find the linked section.
1720   bool
1721   find_linked_text_section(const unsigned char* pshdr,
1722                            const unsigned char* psyms, unsigned int* pshndx);
1723
1724   //
1725   // Make a new Arm_exidx_input_section object for EXIDX section with
1726   // index SHNDX and section header SHDR.  TEXT_SHNDX is the section
1727   // index of the linked text section.
1728   void
1729   make_exidx_input_section(unsigned int shndx,
1730                            const elfcpp::Shdr<32, big_endian>& shdr,
1731                            unsigned int text_shndx,
1732                            const elfcpp::Shdr<32, big_endian>& text_shdr);
1733
1734   // Return the output address of either a plain input section or a
1735   // relaxed input section.  SHNDX is the section index.
1736   Arm_address
1737   simple_input_section_output_address(unsigned int, Output_section*);
1738
1739   typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1740   typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1741     Exidx_section_map;
1742
1743   // List of stub tables.
1744   Stub_table_list stub_tables_;
1745   // Bit vector to tell if a local symbol is a thumb function or not.
1746   // This is only valid after do_count_local_symbol is called.
1747   std::vector<bool> local_symbol_is_thumb_function_;
1748   // processor-specific flags in ELF file header.
1749   elfcpp::Elf_Word processor_specific_flags_;
1750   // Object attributes if there is an .ARM.attributes section or NULL.
1751   Attributes_section_data* attributes_section_data_;
1752   // Mapping symbols information.
1753   Mapping_symbols_info mapping_symbols_info_;
1754   // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1755   std::vector<bool>* section_has_cortex_a8_workaround_;
1756   // Map a text section to its associated .ARM.exidx section, if there is one.
1757   Exidx_section_map exidx_section_map_;
1758   // Whether output local symbol count needs updating.
1759   bool output_local_symbol_count_needs_update_;
1760   // Whether we merge processor flags and attributes of this object to
1761   // output.
1762   bool merge_flags_and_attributes_;
1763 };
1764
1765 // Arm_dynobj class.
1766
1767 template<bool big_endian>
1768 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1769 {
1770  public:
1771   Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1772              const elfcpp::Ehdr<32, big_endian>& ehdr)
1773     : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1774       processor_specific_flags_(0), attributes_section_data_(NULL)
1775   { }
1776
1777   ~Arm_dynobj()
1778   { delete this->attributes_section_data_; }
1779
1780   // Downcast a base pointer to an Arm_relobj pointer.  This is
1781   // not type-safe but we only use Arm_relobj not the base class.
1782   static Arm_dynobj<big_endian>*
1783   as_arm_dynobj(Dynobj* dynobj)
1784   { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1785
1786   // Processor-specific flags in ELF file header.  This is valid only after
1787   // reading symbols.
1788   elfcpp::Elf_Word
1789   processor_specific_flags() const
1790   { return this->processor_specific_flags_; }
1791
1792   // Attributes section data.
1793   const Attributes_section_data*
1794   attributes_section_data() const
1795   { return this->attributes_section_data_; }
1796
1797  protected:
1798   // Read the symbol information.
1799   void
1800   do_read_symbols(Read_symbols_data* sd);
1801
1802  private:
1803   // processor-specific flags in ELF file header.
1804   elfcpp::Elf_Word processor_specific_flags_;
1805   // Object attributes if there is an .ARM.attributes section or NULL.
1806   Attributes_section_data* attributes_section_data_;
1807 };
1808
1809 // Functor to read reloc addends during stub generation.
1810
1811 template<int sh_type, bool big_endian>
1812 struct Stub_addend_reader
1813 {
1814   // Return the addend for a relocation of a particular type.  Depending
1815   // on whether this is a REL or RELA relocation, read the addend from a
1816   // view or from a Reloc object.
1817   elfcpp::Elf_types<32>::Elf_Swxword
1818   operator()(
1819     unsigned int /* r_type */,
1820     const unsigned char* /* view */,
1821     const typename Reloc_types<sh_type,
1822                                32, big_endian>::Reloc& /* reloc */) const;
1823 };
1824
1825 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1826
1827 template<bool big_endian>
1828 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1829 {
1830   elfcpp::Elf_types<32>::Elf_Swxword
1831   operator()(
1832     unsigned int,
1833     const unsigned char*,
1834     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1835 };
1836
1837 // Specialized Stub_addend_reader for RELA type relocation sections.
1838 // We currently do not handle RELA type relocation sections but it is trivial
1839 // to implement the addend reader.  This is provided for completeness and to
1840 // make it easier to add support for RELA relocation sections in the future.
1841
1842 template<bool big_endian>
1843 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1844 {
1845   elfcpp::Elf_types<32>::Elf_Swxword
1846   operator()(
1847     unsigned int,
1848     const unsigned char*,
1849     const typename Reloc_types<elfcpp::SHT_RELA, 32,
1850                                big_endian>::Reloc& reloc) const
1851   { return reloc.get_r_addend(); }
1852 };
1853
1854 // Cortex_a8_reloc class.  We keep record of relocation that may need
1855 // the Cortex-A8 erratum workaround.
1856
1857 class Cortex_a8_reloc
1858 {
1859  public:
1860   Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1861                   Arm_address destination)
1862     : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1863   { }
1864
1865   ~Cortex_a8_reloc()
1866   { }
1867
1868   // Accessors:  This is a read-only class.
1869
1870   // Return the relocation stub associated with this relocation if there is
1871   // one.
1872   const Reloc_stub*
1873   reloc_stub() const
1874   { return this->reloc_stub_; }
1875
1876   // Return the relocation type.
1877   unsigned int
1878   r_type() const
1879   { return this->r_type_; }
1880
1881   // Return the destination address of the relocation.  LSB stores the THUMB
1882   // bit.
1883   Arm_address
1884   destination() const
1885   { return this->destination_; }
1886
1887  private:
1888   // Associated relocation stub if there is one, or NULL.
1889   const Reloc_stub* reloc_stub_;
1890   // Relocation type.
1891   unsigned int r_type_;
1892   // Destination address of this relocation.  LSB is used to distinguish
1893   // ARM/THUMB mode.
1894   Arm_address destination_;
1895 };
1896
1897 // Arm_output_data_got class.  We derive this from Output_data_got to add
1898 // extra methods to handle TLS relocations in a static link.
1899
1900 template<bool big_endian>
1901 class Arm_output_data_got : public Output_data_got<32, big_endian>
1902 {
1903  public:
1904   Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1905     : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1906   { }
1907
1908   // Add a static entry for the GOT entry at OFFSET.  GSYM is a global
1909   // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1910   // applied in a static link.
1911   void
1912   add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1913   { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1914
1915   // Add a static reloc for the GOT entry at OFFSET.  RELOBJ is an object
1916   // defining a local symbol with INDEX.  R_TYPE is the code of a dynamic
1917   // relocation that needs to be applied in a static link.
1918   void
1919   add_static_reloc(unsigned int got_offset, unsigned int r_type,
1920                    Sized_relobj_file<32, big_endian>* relobj,
1921                    unsigned int index)
1922   {
1923     this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1924                                                 index));
1925   }
1926
1927   // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
1928   // The first one is initialized to be 1, which is the module index for
1929   // the main executable and the second one 0.  A reloc of the type
1930   // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1931   // be applied by gold.  GSYM is a global symbol.
1932   void
1933   add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1934
1935   // Same as the above but for a local symbol in OBJECT with INDEX.
1936   void
1937   add_tls_gd32_with_static_reloc(unsigned int got_type,
1938                                  Sized_relobj_file<32, big_endian>* object,
1939                                  unsigned int index);
1940
1941  protected:
1942   // Write out the GOT table.
1943   void
1944   do_write(Output_file*);
1945
1946  private:
1947   // This class represent dynamic relocations that need to be applied by
1948   // gold because we are using TLS relocations in a static link.
1949   class Static_reloc
1950   {
1951    public:
1952     Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1953       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1954     { this->u_.global.symbol = gsym; }
1955
1956     Static_reloc(unsigned int got_offset, unsigned int r_type,
1957           Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1958       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1959     {
1960       this->u_.local.relobj = relobj;
1961       this->u_.local.index = index;
1962     }
1963
1964     // Return the GOT offset.
1965     unsigned int
1966     got_offset() const
1967     { return this->got_offset_; }
1968
1969     // Relocation type.
1970     unsigned int
1971     r_type() const
1972     { return this->r_type_; }
1973
1974     // Whether the symbol is global or not.
1975     bool
1976     symbol_is_global() const
1977     { return this->symbol_is_global_; }
1978
1979     // For a relocation against a global symbol, the global symbol.
1980     Symbol*
1981     symbol() const
1982     {
1983       gold_assert(this->symbol_is_global_);
1984       return this->u_.global.symbol;
1985     }
1986
1987     // For a relocation against a local symbol, the defining object.
1988     Sized_relobj_file<32, big_endian>*
1989     relobj() const
1990     {
1991       gold_assert(!this->symbol_is_global_);
1992       return this->u_.local.relobj;
1993     }
1994
1995     // For a relocation against a local symbol, the local symbol index.
1996     unsigned int
1997     index() const
1998     {
1999       gold_assert(!this->symbol_is_global_);
2000       return this->u_.local.index;
2001     }
2002
2003    private:
2004     // GOT offset of the entry to which this relocation is applied.
2005     unsigned int got_offset_;
2006     // Type of relocation.
2007     unsigned int r_type_;
2008     // Whether this relocation is against a global symbol.
2009     bool symbol_is_global_;
2010     // A global or local symbol.
2011     union
2012     {
2013       struct
2014       {
2015         // For a global symbol, the symbol itself.
2016         Symbol* symbol;
2017       } global;
2018       struct
2019       {
2020         // For a local symbol, the object defining object.
2021         Sized_relobj_file<32, big_endian>* relobj;
2022         // For a local symbol, the symbol index.
2023         unsigned int index;
2024       } local;
2025     } u_;
2026   };
2027
2028   // Symbol table of the output object.
2029   Symbol_table* symbol_table_;
2030   // Layout of the output object.
2031   Layout* layout_;
2032   // Static relocs to be applied to the GOT.
2033   std::vector<Static_reloc> static_relocs_;
2034 };
2035
2036 // The ARM target has many relocation types with odd-sizes or noncontiguous
2037 // bits.  The default handling of relocatable relocation cannot process these
2038 // relocations.  So we have to extend the default code.
2039
2040 template<bool big_endian, int sh_type, typename Classify_reloc>
2041 class Arm_scan_relocatable_relocs :
2042   public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2043 {
2044  public:
2045   // Return the strategy to use for a local symbol which is a section
2046   // symbol, given the relocation type.
2047   inline Relocatable_relocs::Reloc_strategy
2048   local_section_strategy(unsigned int r_type, Relobj*)
2049   {
2050     if (sh_type == elfcpp::SHT_RELA)
2051       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2052     else
2053       {
2054         if (r_type == elfcpp::R_ARM_TARGET1
2055             || r_type == elfcpp::R_ARM_TARGET2)
2056           {
2057             const Target_arm<big_endian>* arm_target =
2058               Target_arm<big_endian>::default_target();
2059             r_type = arm_target->get_real_reloc_type(r_type);
2060           }
2061
2062         switch(r_type)
2063           {
2064           // Relocations that write nothing.  These exclude R_ARM_TARGET1
2065           // and R_ARM_TARGET2.
2066           case elfcpp::R_ARM_NONE:
2067           case elfcpp::R_ARM_V4BX:
2068           case elfcpp::R_ARM_TLS_GOTDESC:
2069           case elfcpp::R_ARM_TLS_CALL:
2070           case elfcpp::R_ARM_TLS_DESCSEQ:
2071           case elfcpp::R_ARM_THM_TLS_CALL:
2072           case elfcpp::R_ARM_GOTRELAX:
2073           case elfcpp::R_ARM_GNU_VTENTRY:
2074           case elfcpp::R_ARM_GNU_VTINHERIT:
2075           case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2076           case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2077             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2078           // These should have been converted to something else above.
2079           case elfcpp::R_ARM_TARGET1:
2080           case elfcpp::R_ARM_TARGET2:
2081             gold_unreachable();
2082           // Relocations that write full 32 bits and
2083           // have alignment of 1.
2084           case elfcpp::R_ARM_ABS32:
2085           case elfcpp::R_ARM_REL32:
2086           case elfcpp::R_ARM_SBREL32:
2087           case elfcpp::R_ARM_GOTOFF32:
2088           case elfcpp::R_ARM_BASE_PREL:
2089           case elfcpp::R_ARM_GOT_BREL:
2090           case elfcpp::R_ARM_BASE_ABS:
2091           case elfcpp::R_ARM_ABS32_NOI:
2092           case elfcpp::R_ARM_REL32_NOI:
2093           case elfcpp::R_ARM_PLT32_ABS:
2094           case elfcpp::R_ARM_GOT_ABS:
2095           case elfcpp::R_ARM_GOT_PREL:
2096           case elfcpp::R_ARM_TLS_GD32:
2097           case elfcpp::R_ARM_TLS_LDM32:
2098           case elfcpp::R_ARM_TLS_LDO32:
2099           case elfcpp::R_ARM_TLS_IE32:
2100           case elfcpp::R_ARM_TLS_LE32:
2101             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2102           default:
2103             // For all other static relocations, return RELOC_SPECIAL.
2104             return Relocatable_relocs::RELOC_SPECIAL;
2105           }
2106       }
2107   }
2108 };
2109
2110 template<bool big_endian>
2111 class Target_arm : public Sized_target<32, big_endian>
2112 {
2113  public:
2114   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2115     Reloc_section;
2116
2117   // When were are relocating a stub, we pass this as the relocation number.
2118   static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2119
2120   Target_arm(const Target::Target_info* info = &arm_info)
2121     : Sized_target<32, big_endian>(info),
2122       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2123       copy_relocs_(elfcpp::R_ARM_COPY),
2124       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2125       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2126       should_force_pic_veneer_(false),
2127       arm_input_section_map_(), attributes_section_data_(NULL),
2128       fix_cortex_a8_(false), cortex_a8_relocs_info_()
2129   { }
2130
2131   // Whether we force PCI branch veneers.
2132   bool
2133   should_force_pic_veneer() const
2134   { return this->should_force_pic_veneer_; }
2135
2136   // Set PIC veneer flag.
2137   void
2138   set_should_force_pic_veneer(bool value)
2139   { this->should_force_pic_veneer_ = value; }
2140
2141   // Whether we use THUMB-2 instructions.
2142   bool
2143   using_thumb2() const
2144   {
2145     Object_attribute* attr =
2146       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2147     int arch = attr->int_value();
2148     return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2149   }
2150
2151   // Whether we use THUMB/THUMB-2 instructions only.
2152   bool
2153   using_thumb_only() const
2154   {
2155     Object_attribute* attr =
2156       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2157
2158     if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2159         || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2160       return true;
2161     if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2162         && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2163       return false;
2164     attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2165     return attr->int_value() == 'M';
2166   }
2167
2168   // Whether we have an NOP instruction.  If not, use mov r0, r0 instead.
2169   bool
2170   may_use_arm_nop() const
2171   {
2172     Object_attribute* attr =
2173       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2174     int arch = attr->int_value();
2175     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2176             || arch == elfcpp::TAG_CPU_ARCH_V6K
2177             || arch == elfcpp::TAG_CPU_ARCH_V7
2178             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2179   }
2180
2181   // Whether we have THUMB-2 NOP.W instruction.
2182   bool
2183   may_use_thumb2_nop() const
2184   {
2185     Object_attribute* attr =
2186       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2187     int arch = attr->int_value();
2188     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2189             || arch == elfcpp::TAG_CPU_ARCH_V7
2190             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2191   }
2192
2193   // Whether we have v4T interworking instructions available.
2194   bool
2195   may_use_v4t_interworking() const
2196   {
2197     Object_attribute* attr =
2198       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2199     int arch = attr->int_value();
2200     return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2201             && arch != elfcpp::TAG_CPU_ARCH_V4);
2202   }
2203
2204   // Whether we have v5T interworking instructions available.
2205   bool
2206   may_use_v5t_interworking() const
2207   {
2208     Object_attribute* attr =
2209       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2210     int arch = attr->int_value();
2211     if (parameters->options().fix_arm1176())
2212       return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2213               || arch == elfcpp::TAG_CPU_ARCH_V7
2214               || arch == elfcpp::TAG_CPU_ARCH_V6_M
2215               || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2216               || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2217     else
2218       return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2219               && arch != elfcpp::TAG_CPU_ARCH_V4
2220               && arch != elfcpp::TAG_CPU_ARCH_V4T);
2221   }
2222
2223   // Process the relocations to determine unreferenced sections for
2224   // garbage collection.
2225   void
2226   gc_process_relocs(Symbol_table* symtab,
2227                     Layout* layout,
2228                     Sized_relobj_file<32, big_endian>* object,
2229                     unsigned int data_shndx,
2230                     unsigned int sh_type,
2231                     const unsigned char* prelocs,
2232                     size_t reloc_count,
2233                     Output_section* output_section,
2234                     bool needs_special_offset_handling,
2235                     size_t local_symbol_count,
2236                     const unsigned char* plocal_symbols);
2237
2238   // Scan the relocations to look for symbol adjustments.
2239   void
2240   scan_relocs(Symbol_table* symtab,
2241               Layout* layout,
2242               Sized_relobj_file<32, big_endian>* object,
2243               unsigned int data_shndx,
2244               unsigned int sh_type,
2245               const unsigned char* prelocs,
2246               size_t reloc_count,
2247               Output_section* output_section,
2248               bool needs_special_offset_handling,
2249               size_t local_symbol_count,
2250               const unsigned char* plocal_symbols);
2251
2252   // Finalize the sections.
2253   void
2254   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2255
2256   // Return the value to use for a dynamic symbol which requires special
2257   // treatment.
2258   uint64_t
2259   do_dynsym_value(const Symbol*) const;
2260
2261   // Relocate a section.
2262   void
2263   relocate_section(const Relocate_info<32, big_endian>*,
2264                    unsigned int sh_type,
2265                    const unsigned char* prelocs,
2266                    size_t reloc_count,
2267                    Output_section* output_section,
2268                    bool needs_special_offset_handling,
2269                    unsigned char* view,
2270                    Arm_address view_address,
2271                    section_size_type view_size,
2272                    const Reloc_symbol_changes*);
2273
2274   // Scan the relocs during a relocatable link.
2275   void
2276   scan_relocatable_relocs(Symbol_table* symtab,
2277                           Layout* layout,
2278                           Sized_relobj_file<32, big_endian>* object,
2279                           unsigned int data_shndx,
2280                           unsigned int sh_type,
2281                           const unsigned char* prelocs,
2282                           size_t reloc_count,
2283                           Output_section* output_section,
2284                           bool needs_special_offset_handling,
2285                           size_t local_symbol_count,
2286                           const unsigned char* plocal_symbols,
2287                           Relocatable_relocs*);
2288
2289   // Emit relocations for a section.
2290   void
2291   relocate_relocs(const Relocate_info<32, big_endian>*,
2292                   unsigned int sh_type,
2293                   const unsigned char* prelocs,
2294                   size_t reloc_count,
2295                   Output_section* output_section,
2296                   typename elfcpp::Elf_types<32>::Elf_Off
2297                     offset_in_output_section,
2298                   const Relocatable_relocs*,
2299                   unsigned char* view,
2300                   Arm_address view_address,
2301                   section_size_type view_size,
2302                   unsigned char* reloc_view,
2303                   section_size_type reloc_view_size);
2304
2305   // Perform target-specific processing in a relocatable link.  This is
2306   // only used if we use the relocation strategy RELOC_SPECIAL.
2307   void
2308   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2309                                unsigned int sh_type,
2310                                const unsigned char* preloc_in,
2311                                size_t relnum,
2312                                Output_section* output_section,
2313                                typename elfcpp::Elf_types<32>::Elf_Off
2314                                  offset_in_output_section,
2315                                unsigned char* view,
2316                                typename elfcpp::Elf_types<32>::Elf_Addr
2317                                  view_address,
2318                                section_size_type view_size,
2319                                unsigned char* preloc_out);
2320
2321   // Return whether SYM is defined by the ABI.
2322   bool
2323   do_is_defined_by_abi(const Symbol* sym) const
2324   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2325
2326   // Return whether there is a GOT section.
2327   bool
2328   has_got_section() const
2329   { return this->got_ != NULL; }
2330
2331   // Return the size of the GOT section.
2332   section_size_type
2333   got_size() const
2334   {
2335     gold_assert(this->got_ != NULL);
2336     return this->got_->data_size();
2337   }
2338
2339   // Return the number of entries in the GOT.
2340   unsigned int
2341   got_entry_count() const
2342   {
2343     if (!this->has_got_section())
2344       return 0;
2345     return this->got_size() / 4;
2346   }
2347
2348   // Return the number of entries in the PLT.
2349   unsigned int
2350   plt_entry_count() const;
2351
2352   // Return the offset of the first non-reserved PLT entry.
2353   unsigned int
2354   first_plt_entry_offset() const;
2355
2356   // Return the size of each PLT entry.
2357   unsigned int
2358   plt_entry_size() const;
2359
2360   // Map platform-specific reloc types
2361   static unsigned int
2362   get_real_reloc_type(unsigned int r_type);
2363
2364   //
2365   // Methods to support stub-generations.
2366   //
2367
2368   // Return the stub factory
2369   const Stub_factory&
2370   stub_factory() const
2371   { return this->stub_factory_; }
2372
2373   // Make a new Arm_input_section object.
2374   Arm_input_section<big_endian>*
2375   new_arm_input_section(Relobj*, unsigned int);
2376
2377   // Find the Arm_input_section object corresponding to the SHNDX-th input
2378   // section of RELOBJ.
2379   Arm_input_section<big_endian>*
2380   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2381
2382   // Make a new Stub_table
2383   Stub_table<big_endian>*
2384   new_stub_table(Arm_input_section<big_endian>*);
2385
2386   // Scan a section for stub generation.
2387   void
2388   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2389                          const unsigned char*, size_t, Output_section*,
2390                          bool, const unsigned char*, Arm_address,
2391                          section_size_type);
2392
2393   // Relocate a stub.
2394   void
2395   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2396                 Output_section*, unsigned char*, Arm_address,
2397                 section_size_type);
2398
2399   // Get the default ARM target.
2400   static Target_arm<big_endian>*
2401   default_target()
2402   {
2403     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2404                 && parameters->target().is_big_endian() == big_endian);
2405     return static_cast<Target_arm<big_endian>*>(
2406              parameters->sized_target<32, big_endian>());
2407   }
2408
2409   // Whether NAME belongs to a mapping symbol.
2410   static bool
2411   is_mapping_symbol_name(const char* name)
2412   {
2413     return (name
2414             && name[0] == '$'
2415             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2416             && (name[2] == '\0' || name[2] == '.'));
2417   }
2418
2419   // Whether we work around the Cortex-A8 erratum.
2420   bool
2421   fix_cortex_a8() const
2422   { return this->fix_cortex_a8_; }
2423
2424   // Whether we merge exidx entries in debuginfo.
2425   bool
2426   merge_exidx_entries() const
2427   { return parameters->options().merge_exidx_entries(); }
2428
2429   // Whether we fix R_ARM_V4BX relocation.
2430   // 0 - do not fix
2431   // 1 - replace with MOV instruction (armv4 target)
2432   // 2 - make interworking veneer (>= armv4t targets only)
2433   General_options::Fix_v4bx
2434   fix_v4bx() const
2435   { return parameters->options().fix_v4bx(); }
2436
2437   // Scan a span of THUMB code section for Cortex-A8 erratum.
2438   void
2439   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2440                                   section_size_type, section_size_type,
2441                                   const unsigned char*, Arm_address);
2442
2443   // Apply Cortex-A8 workaround to a branch.
2444   void
2445   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2446                              unsigned char*, Arm_address);
2447
2448  protected:
2449   // Make the PLT-generator object.
2450   Output_data_plt_arm<big_endian>*
2451   make_data_plt(Layout* layout, Output_data_space* got_plt)
2452   { return this->do_make_data_plt(layout, got_plt); }
2453
2454   // Make an ELF object.
2455   Object*
2456   do_make_elf_object(const std::string&, Input_file*, off_t,
2457                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2458
2459   Object*
2460   do_make_elf_object(const std::string&, Input_file*, off_t,
2461                      const elfcpp::Ehdr<32, !big_endian>&)
2462   { gold_unreachable(); }
2463
2464   Object*
2465   do_make_elf_object(const std::string&, Input_file*, off_t,
2466                       const elfcpp::Ehdr<64, false>&)
2467   { gold_unreachable(); }
2468
2469   Object*
2470   do_make_elf_object(const std::string&, Input_file*, off_t,
2471                      const elfcpp::Ehdr<64, true>&)
2472   { gold_unreachable(); }
2473
2474   // Make an output section.
2475   Output_section*
2476   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2477                          elfcpp::Elf_Xword flags)
2478   { return new Arm_output_section<big_endian>(name, type, flags); }
2479
2480   void
2481   do_adjust_elf_header(unsigned char* view, int len);
2482
2483   // We only need to generate stubs, and hence perform relaxation if we are
2484   // not doing relocatable linking.
2485   bool
2486   do_may_relax() const
2487   { return !parameters->options().relocatable(); }
2488
2489   bool
2490   do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2491
2492   // Determine whether an object attribute tag takes an integer, a
2493   // string or both.
2494   int
2495   do_attribute_arg_type(int tag) const;
2496
2497   // Reorder tags during output.
2498   int
2499   do_attributes_order(int num) const;
2500
2501   // This is called when the target is selected as the default.
2502   void
2503   do_select_as_default_target()
2504   {
2505     // No locking is required since there should only be one default target.
2506     // We cannot have both the big-endian and little-endian ARM targets
2507     // as the default.
2508     gold_assert(arm_reloc_property_table == NULL);
2509     arm_reloc_property_table = new Arm_reloc_property_table();
2510   }
2511
2512   // Virtual function which is set to return true by a target if
2513   // it can use relocation types to determine if a function's
2514   // pointer is taken.
2515   virtual bool
2516   do_can_check_for_function_pointers() const
2517   { return true; }
2518
2519   // Whether a section called SECTION_NAME may have function pointers to
2520   // sections not eligible for safe ICF folding.
2521   virtual bool
2522   do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2523   {
2524     return (!is_prefix_of(".ARM.exidx", section_name)
2525             && !is_prefix_of(".ARM.extab", section_name)
2526             && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2527   }
2528
2529   virtual void
2530   do_define_standard_symbols(Symbol_table*, Layout*);
2531
2532   virtual Output_data_plt_arm<big_endian>*
2533   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
2534   {
2535     return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
2536   }
2537
2538  private:
2539   // The class which scans relocations.
2540   class Scan
2541   {
2542    public:
2543     Scan()
2544       : issued_non_pic_error_(false)
2545     { }
2546
2547     static inline int
2548     get_reference_flags(unsigned int r_type);
2549
2550     inline void
2551     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2552           Sized_relobj_file<32, big_endian>* object,
2553           unsigned int data_shndx,
2554           Output_section* output_section,
2555           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2556           const elfcpp::Sym<32, big_endian>& lsym,
2557           bool is_discarded);
2558
2559     inline void
2560     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2561            Sized_relobj_file<32, big_endian>* object,
2562            unsigned int data_shndx,
2563            Output_section* output_section,
2564            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2565            Symbol* gsym);
2566
2567     inline bool
2568     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2569                                         Sized_relobj_file<32, big_endian>* ,
2570                                         unsigned int ,
2571                                         Output_section* ,
2572                                         const elfcpp::Rel<32, big_endian>& ,
2573                                         unsigned int ,
2574                                         const elfcpp::Sym<32, big_endian>&);
2575
2576     inline bool
2577     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2578                                          Sized_relobj_file<32, big_endian>* ,
2579                                          unsigned int ,
2580                                          Output_section* ,
2581                                          const elfcpp::Rel<32, big_endian>& ,
2582                                          unsigned int , Symbol*);
2583
2584    private:
2585     static void
2586     unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2587                             unsigned int r_type);
2588
2589     static void
2590     unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2591                              unsigned int r_type, Symbol*);
2592
2593     void
2594     check_non_pic(Relobj*, unsigned int r_type);
2595
2596     // Almost identical to Symbol::needs_plt_entry except that it also
2597     // handles STT_ARM_TFUNC.
2598     static bool
2599     symbol_needs_plt_entry(const Symbol* sym)
2600     {
2601       // An undefined symbol from an executable does not need a PLT entry.
2602       if (sym->is_undefined() && !parameters->options().shared())
2603         return false;
2604
2605       return (!parameters->doing_static_link()
2606               && (sym->type() == elfcpp::STT_FUNC
2607                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2608               && (sym->is_from_dynobj()
2609                   || sym->is_undefined()
2610                   || sym->is_preemptible()));
2611     }
2612
2613     inline bool
2614     possible_function_pointer_reloc(unsigned int r_type);
2615
2616     // Whether we have issued an error about a non-PIC compilation.
2617     bool issued_non_pic_error_;
2618   };
2619
2620   // The class which implements relocation.
2621   class Relocate
2622   {
2623    public:
2624     Relocate()
2625     { }
2626
2627     ~Relocate()
2628     { }
2629
2630     // Return whether the static relocation needs to be applied.
2631     inline bool
2632     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2633                               unsigned int r_type,
2634                               bool is_32bit,
2635                               Output_section* output_section);
2636
2637     // Do a relocation.  Return false if the caller should not issue
2638     // any warnings about this relocation.
2639     inline bool
2640     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2641              Output_section*,  size_t relnum,
2642              const elfcpp::Rel<32, big_endian>&,
2643              unsigned int r_type, const Sized_symbol<32>*,
2644              const Symbol_value<32>*,
2645              unsigned char*, Arm_address,
2646              section_size_type);
2647
2648     // Return whether we want to pass flag NON_PIC_REF for this
2649     // reloc.  This means the relocation type accesses a symbol not via
2650     // GOT or PLT.
2651     static inline bool
2652     reloc_is_non_pic(unsigned int r_type)
2653     {
2654       switch (r_type)
2655         {
2656         // These relocation types reference GOT or PLT entries explicitly.
2657         case elfcpp::R_ARM_GOT_BREL:
2658         case elfcpp::R_ARM_GOT_ABS:
2659         case elfcpp::R_ARM_GOT_PREL:
2660         case elfcpp::R_ARM_GOT_BREL12:
2661         case elfcpp::R_ARM_PLT32_ABS:
2662         case elfcpp::R_ARM_TLS_GD32:
2663         case elfcpp::R_ARM_TLS_LDM32:
2664         case elfcpp::R_ARM_TLS_IE32:
2665         case elfcpp::R_ARM_TLS_IE12GP:
2666
2667         // These relocate types may use PLT entries.
2668         case elfcpp::R_ARM_CALL:
2669         case elfcpp::R_ARM_THM_CALL:
2670         case elfcpp::R_ARM_JUMP24:
2671         case elfcpp::R_ARM_THM_JUMP24:
2672         case elfcpp::R_ARM_THM_JUMP19:
2673         case elfcpp::R_ARM_PLT32:
2674         case elfcpp::R_ARM_THM_XPC22:
2675         case elfcpp::R_ARM_PREL31:
2676         case elfcpp::R_ARM_SBREL31:
2677           return false;
2678
2679         default:
2680           return true;
2681         }
2682     }
2683
2684    private:
2685     // Do a TLS relocation.
2686     inline typename Arm_relocate_functions<big_endian>::Status
2687     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2688                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2689                  const Sized_symbol<32>*, const Symbol_value<32>*,
2690                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2691                  section_size_type);
2692
2693   };
2694
2695   // A class which returns the size required for a relocation type,
2696   // used while scanning relocs during a relocatable link.
2697   class Relocatable_size_for_reloc
2698   {
2699    public:
2700     unsigned int
2701     get_size_for_reloc(unsigned int, Relobj*);
2702   };
2703
2704   // Adjust TLS relocation type based on the options and whether this
2705   // is a local symbol.
2706   static tls::Tls_optimization
2707   optimize_tls_reloc(bool is_final, int r_type);
2708
2709   // Get the GOT section, creating it if necessary.
2710   Arm_output_data_got<big_endian>*
2711   got_section(Symbol_table*, Layout*);
2712
2713   // Get the GOT PLT section.
2714   Output_data_space*
2715   got_plt_section() const
2716   {
2717     gold_assert(this->got_plt_ != NULL);
2718     return this->got_plt_;
2719   }
2720
2721   // Create a PLT entry for a global symbol.
2722   void
2723   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2724
2725   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2726   void
2727   define_tls_base_symbol(Symbol_table*, Layout*);
2728
2729   // Create a GOT entry for the TLS module index.
2730   unsigned int
2731   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2732                       Sized_relobj_file<32, big_endian>* object);
2733
2734   // Get the PLT section.
2735   const Output_data_plt_arm<big_endian>*
2736   plt_section() const
2737   {
2738     gold_assert(this->plt_ != NULL);
2739     return this->plt_;
2740   }
2741
2742   // Get the dynamic reloc section, creating it if necessary.
2743   Reloc_section*
2744   rel_dyn_section(Layout*);
2745
2746   // Get the section to use for TLS_DESC relocations.
2747   Reloc_section*
2748   rel_tls_desc_section(Layout*) const;
2749
2750   // Return true if the symbol may need a COPY relocation.
2751   // References from an executable object to non-function symbols
2752   // defined in a dynamic object may need a COPY relocation.
2753   bool
2754   may_need_copy_reloc(Symbol* gsym)
2755   {
2756     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2757             && gsym->may_need_copy_reloc());
2758   }
2759
2760   // Add a potential copy relocation.
2761   void
2762   copy_reloc(Symbol_table* symtab, Layout* layout,
2763              Sized_relobj_file<32, big_endian>* object,
2764              unsigned int shndx, Output_section* output_section,
2765              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2766   {
2767     this->copy_relocs_.copy_reloc(symtab, layout,
2768                                   symtab->get_sized_symbol<32>(sym),
2769                                   object, shndx, output_section, reloc,
2770                                   this->rel_dyn_section(layout));
2771   }
2772
2773   // Whether two EABI versions are compatible.
2774   static bool
2775   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2776
2777   // Merge processor-specific flags from input object and those in the ELF
2778   // header of the output.
2779   void
2780   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2781
2782   // Get the secondary compatible architecture.
2783   static int
2784   get_secondary_compatible_arch(const Attributes_section_data*);
2785
2786   // Set the secondary compatible architecture.
2787   static void
2788   set_secondary_compatible_arch(Attributes_section_data*, int);
2789
2790   static int
2791   tag_cpu_arch_combine(const char*, int, int*, int, int);
2792
2793   // Helper to print AEABI enum tag value.
2794   static std::string
2795   aeabi_enum_name(unsigned int);
2796
2797   // Return string value for TAG_CPU_name.
2798   static std::string
2799   tag_cpu_name_value(unsigned int);
2800
2801   // Query attributes object to see if integer divide instructions may be
2802   // present in an object.
2803   static bool
2804   attributes_accept_div(int arch, int profile,
2805                         const Object_attribute* div_attr);
2806
2807   // Query attributes object to see if integer divide instructions are
2808   // forbidden to be in the object.  This is not the inverse of
2809   // attributes_accept_div.
2810   static bool
2811   attributes_forbid_div(const Object_attribute* div_attr);
2812
2813   // Merge object attributes from input object and those in the output.
2814   void
2815   merge_object_attributes(const char*, const Attributes_section_data*);
2816
2817   // Helper to get an AEABI object attribute
2818   Object_attribute*
2819   get_aeabi_object_attribute(int tag) const
2820   {
2821     Attributes_section_data* pasd = this->attributes_section_data_;
2822     gold_assert(pasd != NULL);
2823     Object_attribute* attr =
2824       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2825     gold_assert(attr != NULL);
2826     return attr;
2827   }
2828
2829   //
2830   // Methods to support stub-generations.
2831   //
2832
2833   // Group input sections for stub generation.
2834   void
2835   group_sections(Layout*, section_size_type, bool, const Task*);
2836
2837   // Scan a relocation for stub generation.
2838   void
2839   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2840                       const Sized_symbol<32>*, unsigned int,
2841                       const Symbol_value<32>*,
2842                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2843
2844   // Scan a relocation section for stub.
2845   template<int sh_type>
2846   void
2847   scan_reloc_section_for_stubs(
2848       const Relocate_info<32, big_endian>* relinfo,
2849       const unsigned char* prelocs,
2850       size_t reloc_count,
2851       Output_section* output_section,
2852       bool needs_special_offset_handling,
2853       const unsigned char* view,
2854       elfcpp::Elf_types<32>::Elf_Addr view_address,
2855       section_size_type);
2856
2857   // Fix .ARM.exidx section coverage.
2858   void
2859   fix_exidx_coverage(Layout*, const Input_objects*,
2860                      Arm_output_section<big_endian>*, Symbol_table*,
2861                      const Task*);
2862
2863   // Functors for STL set.
2864   struct output_section_address_less_than
2865   {
2866     bool
2867     operator()(const Output_section* s1, const Output_section* s2) const
2868     { return s1->address() < s2->address(); }
2869   };
2870
2871   // Information about this specific target which we pass to the
2872   // general Target structure.
2873   static const Target::Target_info arm_info;
2874
2875   // The types of GOT entries needed for this platform.
2876   // These values are exposed to the ABI in an incremental link.
2877   // Do not renumber existing values without changing the version
2878   // number of the .gnu_incremental_inputs section.
2879   enum Got_type
2880   {
2881     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2882     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2883     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2884     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2885     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2886   };
2887
2888   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2889
2890   // Map input section to Arm_input_section.
2891   typedef Unordered_map<Section_id,
2892                         Arm_input_section<big_endian>*,
2893                         Section_id_hash>
2894           Arm_input_section_map;
2895
2896   // Map output addresses to relocs for Cortex-A8 erratum.
2897   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2898           Cortex_a8_relocs_info;
2899
2900   // The GOT section.
2901   Arm_output_data_got<big_endian>* got_;
2902   // The PLT section.
2903   Output_data_plt_arm<big_endian>* plt_;
2904   // The GOT PLT section.
2905   Output_data_space* got_plt_;
2906   // The dynamic reloc section.
2907   Reloc_section* rel_dyn_;
2908   // Relocs saved to avoid a COPY reloc.
2909   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2910   // Offset of the GOT entry for the TLS module index.
2911   unsigned int got_mod_index_offset_;
2912   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2913   bool tls_base_symbol_defined_;
2914   // Vector of Stub_tables created.
2915   Stub_table_list stub_tables_;
2916   // Stub factory.
2917   const Stub_factory &stub_factory_;
2918   // Whether we force PIC branch veneers.
2919   bool should_force_pic_veneer_;
2920   // Map for locating Arm_input_sections.
2921   Arm_input_section_map arm_input_section_map_;
2922   // Attributes section data in output.
2923   Attributes_section_data* attributes_section_data_;
2924   // Whether we want to fix code for Cortex-A8 erratum.
2925   bool fix_cortex_a8_;
2926   // Map addresses to relocs for Cortex-A8 erratum.
2927   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2928 };
2929
2930 template<bool big_endian>
2931 const Target::Target_info Target_arm<big_endian>::arm_info =
2932 {
2933   32,                   // size
2934   big_endian,           // is_big_endian
2935   elfcpp::EM_ARM,       // machine_code
2936   false,                // has_make_symbol
2937   false,                // has_resolve
2938   false,                // has_code_fill
2939   true,                 // is_default_stack_executable
2940   false,                // can_icf_inline_merge_sections
2941   '\0',                 // wrap_char
2942   "/usr/lib/libc.so.1", // dynamic_linker
2943   0x8000,               // default_text_segment_address
2944   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2945   0x1000,               // common_pagesize (overridable by -z common-page-size)
2946   false,                // isolate_execinstr
2947   0,                    // rosegment_gap
2948   elfcpp::SHN_UNDEF,    // small_common_shndx
2949   elfcpp::SHN_UNDEF,    // large_common_shndx
2950   0,                    // small_common_section_flags
2951   0,                    // large_common_section_flags
2952   ".ARM.attributes",    // attributes_section
2953   "aeabi",              // attributes_vendor
2954   "_start"              // entry_symbol_name
2955 };
2956
2957 // Arm relocate functions class
2958 //
2959
2960 template<bool big_endian>
2961 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2962 {
2963  public:
2964   typedef enum
2965   {
2966     STATUS_OKAY,        // No error during relocation.
2967     STATUS_OVERFLOW,    // Relocation overflow.
2968     STATUS_BAD_RELOC    // Relocation cannot be applied.
2969   } Status;
2970
2971  private:
2972   typedef Relocate_functions<32, big_endian> Base;
2973   typedef Arm_relocate_functions<big_endian> This;
2974
2975   // Encoding of imm16 argument for movt and movw ARM instructions
2976   // from ARM ARM:
2977   //
2978   //     imm16 := imm4 | imm12
2979   //
2980   //  f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
2981   // +-------+---------------+-------+-------+-----------------------+
2982   // |       |               |imm4   |       |imm12                  |
2983   // +-------+---------------+-------+-------+-----------------------+
2984
2985   // Extract the relocation addend from VAL based on the ARM
2986   // instruction encoding described above.
2987   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2988   extract_arm_movw_movt_addend(
2989       typename elfcpp::Swap<32, big_endian>::Valtype val)
2990   {
2991     // According to the Elf ABI for ARM Architecture the immediate
2992     // field is sign-extended to form the addend.
2993     return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2994   }
2995
2996   // Insert X into VAL based on the ARM instruction encoding described
2997   // above.
2998   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2999   insert_val_arm_movw_movt(
3000       typename elfcpp::Swap<32, big_endian>::Valtype val,
3001       typename elfcpp::Swap<32, big_endian>::Valtype x)
3002   {
3003     val &= 0xfff0f000;
3004     val |= x & 0x0fff;
3005     val |= (x & 0xf000) << 4;
3006     return val;
3007   }
3008
3009   // Encoding of imm16 argument for movt and movw Thumb2 instructions
3010   // from ARM ARM:
3011   //
3012   //     imm16 := imm4 | i | imm3 | imm8
3013   //
3014   //  f e d c b a 9 8 7 6 5 4 3 2 1 0  f e d c b a 9 8 7 6 5 4 3 2 1 0
3015   // +---------+-+-----------+-------++-+-----+-------+---------------+
3016   // |         |i|           |imm4   || |imm3 |       |imm8           |
3017   // +---------+-+-----------+-------++-+-----+-------+---------------+
3018
3019   // Extract the relocation addend from VAL based on the Thumb2
3020   // instruction encoding described above.
3021   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3022   extract_thumb_movw_movt_addend(
3023       typename elfcpp::Swap<32, big_endian>::Valtype val)
3024   {
3025     // According to the Elf ABI for ARM Architecture the immediate
3026     // field is sign-extended to form the addend.
3027     return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3028                                    | ((val >> 15) & 0x0800)
3029                                    | ((val >> 4) & 0x0700)
3030                                    | (val & 0x00ff));
3031   }
3032
3033   // Insert X into VAL based on the Thumb2 instruction encoding
3034   // described above.
3035   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3036   insert_val_thumb_movw_movt(
3037       typename elfcpp::Swap<32, big_endian>::Valtype val,
3038       typename elfcpp::Swap<32, big_endian>::Valtype x)
3039   {
3040     val &= 0xfbf08f00;
3041     val |= (x & 0xf000) << 4;
3042     val |= (x & 0x0800) << 15;
3043     val |= (x & 0x0700) << 4;
3044     val |= (x & 0x00ff);
3045     return val;
3046   }
3047
3048   // Calculate the smallest constant Kn for the specified residual.
3049   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3050   static uint32_t
3051   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3052   {
3053     int32_t msb;
3054
3055     if (residual == 0)
3056       return 0;
3057     // Determine the most significant bit in the residual and
3058     // align the resulting value to a 2-bit boundary.
3059     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3060       ;
3061     // The desired shift is now (msb - 6), or zero, whichever
3062     // is the greater.
3063     return (((msb - 6) < 0) ? 0 : (msb - 6));
3064   }
3065
3066   // Calculate the final residual for the specified group index.
3067   // If the passed group index is less than zero, the method will return
3068   // the value of the specified residual without any change.
3069   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3070   static typename elfcpp::Swap<32, big_endian>::Valtype
3071   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3072                     const int group)
3073   {
3074     for (int n = 0; n <= group; n++)
3075       {
3076         // Calculate which part of the value to mask.
3077         uint32_t shift = calc_grp_kn(residual);
3078         // Calculate the residual for the next time around.
3079         residual &= ~(residual & (0xff << shift));
3080       }
3081
3082     return residual;
3083   }
3084
3085   // Calculate the value of Gn for the specified group index.
3086   // We return it in the form of an encoded constant-and-rotation.
3087   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3088   static typename elfcpp::Swap<32, big_endian>::Valtype
3089   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3090               const int group)
3091   {
3092     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3093     uint32_t shift = 0;
3094
3095     for (int n = 0; n <= group; n++)
3096       {
3097         // Calculate which part of the value to mask.
3098         shift = calc_grp_kn(residual);
3099         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3100         gn = residual & (0xff << shift);
3101         // Calculate the residual for the next time around.
3102         residual &= ~gn;
3103       }
3104     // Return Gn in the form of an encoded constant-and-rotation.
3105     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3106   }
3107
3108  public:
3109   // Handle ARM long branches.
3110   static typename This::Status
3111   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3112                     unsigned char*, const Sized_symbol<32>*,
3113                     const Arm_relobj<big_endian>*, unsigned int,
3114                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3115
3116   // Handle THUMB long branches.
3117   static typename This::Status
3118   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3119                       unsigned char*, const Sized_symbol<32>*,
3120                       const Arm_relobj<big_endian>*, unsigned int,
3121                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3122
3123
3124   // Return the branch offset of a 32-bit THUMB branch.
3125   static inline int32_t
3126   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3127   {
3128     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3129     // involving the J1 and J2 bits.
3130     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3131     uint32_t upper = upper_insn & 0x3ffU;
3132     uint32_t lower = lower_insn & 0x7ffU;
3133     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3134     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3135     uint32_t i1 = j1 ^ s ? 0 : 1;
3136     uint32_t i2 = j2 ^ s ? 0 : 1;
3137
3138     return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3139                                    | (upper << 12) | (lower << 1));
3140   }
3141
3142   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3143   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3144   // responsible for overflow checking and BLX offset adjustment.
3145   static inline uint16_t
3146   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3147   {
3148     uint32_t s = offset < 0 ? 1 : 0;
3149     uint32_t bits = static_cast<uint32_t>(offset);
3150     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3151   }
3152
3153   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3154   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3155   // responsible for overflow checking and BLX offset adjustment.
3156   static inline uint16_t
3157   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3158   {
3159     uint32_t s = offset < 0 ? 1 : 0;
3160     uint32_t bits = static_cast<uint32_t>(offset);
3161     return ((lower_insn & ~0x2fffU)
3162             | ((((bits >> 23) & 1) ^ !s) << 13)
3163             | ((((bits >> 22) & 1) ^ !s) << 11)
3164             | ((bits >> 1) & 0x7ffU));
3165   }
3166
3167   // Return the branch offset of a 32-bit THUMB conditional branch.
3168   static inline int32_t
3169   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3170   {
3171     uint32_t s = (upper_insn & 0x0400U) >> 10;
3172     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3173     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3174     uint32_t lower = (lower_insn & 0x07ffU);
3175     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3176
3177     return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3178   }
3179
3180   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3181   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3182   // Caller is responsible for overflow checking.
3183   static inline uint16_t
3184   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3185   {
3186     uint32_t s = offset < 0 ? 1 : 0;
3187     uint32_t bits = static_cast<uint32_t>(offset);
3188     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3189   }
3190
3191   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3192   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3193   // The caller is responsible for overflow checking.
3194   static inline uint16_t
3195   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3196   {
3197     uint32_t bits = static_cast<uint32_t>(offset);
3198     uint32_t j2 = (bits & 0x00080000U) >> 19;
3199     uint32_t j1 = (bits & 0x00040000U) >> 18;
3200     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3201
3202     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3203   }
3204
3205   // R_ARM_ABS8: S + A
3206   static inline typename This::Status
3207   abs8(unsigned char* view,
3208        const Sized_relobj_file<32, big_endian>* object,
3209        const Symbol_value<32>* psymval)
3210   {
3211     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3212     Valtype* wv = reinterpret_cast<Valtype*>(view);
3213     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3214     int32_t addend = Bits<8>::sign_extend32(val);
3215     Arm_address x = psymval->value(object, addend);
3216     val = Bits<32>::bit_select32(val, x, 0xffU);
3217     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3218
3219     // R_ARM_ABS8 permits signed or unsigned results.
3220     return (Bits<8>::has_signed_unsigned_overflow32(x)
3221             ? This::STATUS_OVERFLOW
3222             : This::STATUS_OKAY);
3223   }
3224
3225   // R_ARM_THM_ABS5: S + A
3226   static inline typename This::Status
3227   thm_abs5(unsigned char* view,
3228        const Sized_relobj_file<32, big_endian>* object,
3229        const Symbol_value<32>* psymval)
3230   {
3231     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3232     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3233     Valtype* wv = reinterpret_cast<Valtype*>(view);
3234     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3235     Reltype addend = (val & 0x7e0U) >> 6;
3236     Reltype x = psymval->value(object, addend);
3237     val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3238     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3239     return (Bits<5>::has_overflow32(x)
3240             ? This::STATUS_OVERFLOW
3241             : This::STATUS_OKAY);
3242   }
3243
3244   // R_ARM_ABS12: S + A
3245   static inline typename This::Status
3246   abs12(unsigned char* view,
3247         const Sized_relobj_file<32, big_endian>* object,
3248         const Symbol_value<32>* psymval)
3249   {
3250     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3251     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3252     Valtype* wv = reinterpret_cast<Valtype*>(view);
3253     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3254     Reltype addend = val & 0x0fffU;
3255     Reltype x = psymval->value(object, addend);
3256     val = Bits<32>::bit_select32(val, x, 0x0fffU);
3257     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3258     return (Bits<12>::has_overflow32(x)
3259             ? This::STATUS_OVERFLOW
3260             : This::STATUS_OKAY);
3261   }
3262
3263   // R_ARM_ABS16: S + A
3264   static inline typename This::Status
3265   abs16(unsigned char* view,
3266         const Sized_relobj_file<32, big_endian>* object,
3267         const Symbol_value<32>* psymval)
3268   {
3269     typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3270     Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3271     int32_t addend = Bits<16>::sign_extend32(val);
3272     Arm_address x = psymval->value(object, addend);
3273     val = Bits<32>::bit_select32(val, x, 0xffffU);
3274     elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3275
3276     // R_ARM_ABS16 permits signed or unsigned results.
3277     return (Bits<16>::has_signed_unsigned_overflow32(x)
3278             ? This::STATUS_OVERFLOW
3279             : This::STATUS_OKAY);
3280   }
3281
3282   // R_ARM_ABS32: (S + A) | T
3283   static inline typename This::Status
3284   abs32(unsigned char* view,
3285         const Sized_relobj_file<32, big_endian>* object,
3286         const Symbol_value<32>* psymval,
3287         Arm_address thumb_bit)
3288   {
3289     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3290     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3291     Valtype x = psymval->value(object, addend) | thumb_bit;
3292     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3293     return This::STATUS_OKAY;
3294   }
3295
3296   // R_ARM_REL32: (S + A) | T - P
3297   static inline typename This::Status
3298   rel32(unsigned char* view,
3299         const Sized_relobj_file<32, big_endian>* object,
3300         const Symbol_value<32>* psymval,
3301         Arm_address address,
3302         Arm_address thumb_bit)
3303   {
3304     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3305     Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3306     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3307     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3308     return This::STATUS_OKAY;
3309   }
3310
3311   // R_ARM_THM_JUMP24: (S + A) | T - P
3312   static typename This::Status
3313   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3314              const Symbol_value<32>* psymval, Arm_address address,
3315              Arm_address thumb_bit);
3316
3317   // R_ARM_THM_JUMP6: S + A â€“ P
3318   static inline typename This::Status
3319   thm_jump6(unsigned char* view,
3320             const Sized_relobj_file<32, big_endian>* object,
3321             const Symbol_value<32>* psymval,
3322             Arm_address address)
3323   {
3324     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3325     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3326     Valtype* wv = reinterpret_cast<Valtype*>(view);
3327     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3328     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3329     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3330     Reltype x = (psymval->value(object, addend) - address);
3331     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3332     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3333     // CZB does only forward jumps.
3334     return ((x > 0x007e)
3335             ? This::STATUS_OVERFLOW
3336             : This::STATUS_OKAY);
3337   }
3338
3339   // R_ARM_THM_JUMP8: S + A â€“ P
3340   static inline typename This::Status
3341   thm_jump8(unsigned char* view,
3342             const Sized_relobj_file<32, big_endian>* object,
3343             const Symbol_value<32>* psymval,
3344             Arm_address address)
3345   {
3346     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3347     Valtype* wv = reinterpret_cast<Valtype*>(view);
3348     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3349     int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3350     int32_t x = (psymval->value(object, addend) - address);
3351     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3352                                                 | ((x & 0x01fe) >> 1)));
3353     // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3354     return (Bits<9>::has_overflow32(x)
3355             ? This::STATUS_OVERFLOW
3356             : This::STATUS_OKAY);
3357   }
3358
3359   // R_ARM_THM_JUMP11: S + A â€“ P
3360   static inline typename This::Status
3361   thm_jump11(unsigned char* view,
3362             const Sized_relobj_file<32, big_endian>* object,
3363             const Symbol_value<32>* psymval,
3364             Arm_address address)
3365   {
3366     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3367     Valtype* wv = reinterpret_cast<Valtype*>(view);
3368     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3369     int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3370     int32_t x = (psymval->value(object, addend) - address);
3371     elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3372                                                 | ((x & 0x0ffe) >> 1)));
3373     // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3374     return (Bits<12>::has_overflow32(x)
3375             ? This::STATUS_OVERFLOW
3376             : This::STATUS_OKAY);
3377   }
3378
3379   // R_ARM_BASE_PREL: B(S) + A - P
3380   static inline typename This::Status
3381   base_prel(unsigned char* view,
3382             Arm_address origin,
3383             Arm_address address)
3384   {
3385     Base::rel32(view, origin - address);
3386     return STATUS_OKAY;
3387   }
3388
3389   // R_ARM_BASE_ABS: B(S) + A
3390   static inline typename This::Status
3391   base_abs(unsigned char* view,
3392            Arm_address origin)
3393   {
3394     Base::rel32(view, origin);
3395     return STATUS_OKAY;
3396   }
3397
3398   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3399   static inline typename This::Status
3400   got_brel(unsigned char* view,
3401            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3402   {
3403     Base::rel32(view, got_offset);
3404     return This::STATUS_OKAY;
3405   }
3406
3407   // R_ARM_GOT_PREL: GOT(S) + A - P
3408   static inline typename This::Status
3409   got_prel(unsigned char* view,
3410            Arm_address got_entry,
3411            Arm_address address)
3412   {
3413     Base::rel32(view, got_entry - address);
3414     return This::STATUS_OKAY;
3415   }
3416
3417   // R_ARM_PREL: (S + A) | T - P
3418   static inline typename This::Status
3419   prel31(unsigned char* view,
3420          const Sized_relobj_file<32, big_endian>* object,
3421          const Symbol_value<32>* psymval,
3422          Arm_address address,
3423          Arm_address thumb_bit)
3424   {
3425     typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3426     Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3427     Valtype addend = Bits<31>::sign_extend32(val);
3428     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3429     val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3430     elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3431     return (Bits<31>::has_overflow32(x)
3432             ? This::STATUS_OVERFLOW
3433             : This::STATUS_OKAY);
3434   }
3435
3436   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3437   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3438   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3439   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3440   static inline typename This::Status
3441   movw(unsigned char* view,
3442        const Sized_relobj_file<32, big_endian>* object,
3443        const Symbol_value<32>* psymval,
3444        Arm_address relative_address_base,
3445        Arm_address thumb_bit,
3446        bool check_overflow)
3447   {
3448     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3449     Valtype* wv = reinterpret_cast<Valtype*>(view);
3450     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3451     Valtype addend = This::extract_arm_movw_movt_addend(val);
3452     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3453                  - relative_address_base);
3454     val = This::insert_val_arm_movw_movt(val, x);
3455     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3456     return ((check_overflow && Bits<16>::has_overflow32(x))
3457             ? This::STATUS_OVERFLOW
3458             : This::STATUS_OKAY);
3459   }
3460
3461   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3462   // R_ARM_MOVT_PREL: S + A - P
3463   // R_ARM_MOVT_BREL: S + A - B(S)
3464   static inline typename This::Status
3465   movt(unsigned char* view,
3466        const Sized_relobj_file<32, big_endian>* object,
3467        const Symbol_value<32>* psymval,
3468        Arm_address relative_address_base)
3469   {
3470     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3471     Valtype* wv = reinterpret_cast<Valtype*>(view);
3472     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3473     Valtype addend = This::extract_arm_movw_movt_addend(val);
3474     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3475     val = This::insert_val_arm_movw_movt(val, x);
3476     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3477     // FIXME: IHI0044D says that we should check for overflow.
3478     return This::STATUS_OKAY;
3479   }
3480
3481   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3482   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3483   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3484   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3485   static inline typename This::Status
3486   thm_movw(unsigned char* view,
3487            const Sized_relobj_file<32, big_endian>* object,
3488            const Symbol_value<32>* psymval,
3489            Arm_address relative_address_base,
3490            Arm_address thumb_bit,
3491            bool check_overflow)
3492   {
3493     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3494     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3495     Valtype* wv = reinterpret_cast<Valtype*>(view);
3496     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3497                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3498     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3499     Reltype x =
3500       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3501     val = This::insert_val_thumb_movw_movt(val, x);
3502     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3503     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3504     return ((check_overflow && Bits<16>::has_overflow32(x))
3505             ? This::STATUS_OVERFLOW
3506             : This::STATUS_OKAY);
3507   }
3508
3509   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3510   // R_ARM_THM_MOVT_PREL: S + A - P
3511   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3512   static inline typename This::Status
3513   thm_movt(unsigned char* view,
3514            const Sized_relobj_file<32, big_endian>* object,
3515            const Symbol_value<32>* psymval,
3516            Arm_address relative_address_base)
3517   {
3518     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3519     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3520     Valtype* wv = reinterpret_cast<Valtype*>(view);
3521     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3522                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3523     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3524     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3525     val = This::insert_val_thumb_movw_movt(val, x);
3526     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3527     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3528     return This::STATUS_OKAY;
3529   }
3530
3531   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3532   static inline typename This::Status
3533   thm_alu11(unsigned char* view,
3534             const Sized_relobj_file<32, big_endian>* object,
3535             const Symbol_value<32>* psymval,
3536             Arm_address address,
3537             Arm_address thumb_bit)
3538   {
3539     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3540     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3541     Valtype* wv = reinterpret_cast<Valtype*>(view);
3542     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3543                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3544
3545     //        f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0
3546     // -----------------------------------------------------------------------
3547     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3548     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3549     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3550     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3551     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3552     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3553
3554     // Determine a sign for the addend.
3555     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3556                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3557     // Thumb2 addend encoding:
3558     // imm12 := i | imm3 | imm8
3559     int32_t addend = (insn & 0xff)
3560                      | ((insn & 0x00007000) >> 4)
3561                      | ((insn & 0x04000000) >> 15);
3562     // Apply a sign to the added.
3563     addend *= sign;
3564
3565     int32_t x = (psymval->value(object, addend) | thumb_bit)
3566                 - (address & 0xfffffffc);
3567     Reltype val = abs(x);
3568     // Mask out the value and a distinct part of the ADD/SUB opcode
3569     // (bits 7:5 of opword).
3570     insn = (insn & 0xfb0f8f00)
3571            | (val & 0xff)
3572            | ((val & 0x700) << 4)
3573            | ((val & 0x800) << 15);
3574     // Set the opcode according to whether the value to go in the
3575     // place is negative.
3576     if (x < 0)
3577       insn |= 0x00a00000;
3578
3579     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3580     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3581     return ((val > 0xfff) ?
3582             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3583   }
3584
3585   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3586   static inline typename This::Status
3587   thm_pc8(unsigned char* view,
3588           const Sized_relobj_file<32, big_endian>* object,
3589           const Symbol_value<32>* psymval,
3590           Arm_address address)
3591   {
3592     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3593     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3594     Valtype* wv = reinterpret_cast<Valtype*>(view);
3595     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3596     Reltype addend = ((insn & 0x00ff) << 2);
3597     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3598     Reltype val = abs(x);
3599     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3600
3601     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3602     return ((val > 0x03fc)
3603             ? This::STATUS_OVERFLOW
3604             : This::STATUS_OKAY);
3605   }
3606
3607   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3608   static inline typename This::Status
3609   thm_pc12(unsigned char* view,
3610            const Sized_relobj_file<32, big_endian>* object,
3611            const Symbol_value<32>* psymval,
3612            Arm_address address)
3613   {
3614     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3615     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3616     Valtype* wv = reinterpret_cast<Valtype*>(view);
3617     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3618                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3619     // Determine a sign for the addend (positive if the U bit is 1).
3620     const int sign = (insn & 0x00800000) ? 1 : -1;
3621     int32_t addend = (insn & 0xfff);
3622     // Apply a sign to the added.
3623     addend *= sign;
3624
3625     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3626     Reltype val = abs(x);
3627     // Mask out and apply the value and the U bit.
3628     insn = (insn & 0xff7ff000) | (val & 0xfff);
3629     // Set the U bit according to whether the value to go in the
3630     // place is positive.
3631     if (x >= 0)
3632       insn |= 0x00800000;
3633
3634     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3635     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3636     return ((val > 0xfff) ?
3637             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3638   }
3639
3640   // R_ARM_V4BX
3641   static inline typename This::Status
3642   v4bx(const Relocate_info<32, big_endian>* relinfo,
3643        unsigned char* view,
3644        const Arm_relobj<big_endian>* object,
3645        const Arm_address address,
3646        const bool is_interworking)
3647   {
3648
3649     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3650     Valtype* wv = reinterpret_cast<Valtype*>(view);
3651     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3652
3653     // Ensure that we have a BX instruction.
3654     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3655     const uint32_t reg = (val & 0xf);
3656     if (is_interworking && reg != 0xf)
3657       {
3658         Stub_table<big_endian>* stub_table =
3659             object->stub_table(relinfo->data_shndx);
3660         gold_assert(stub_table != NULL);
3661
3662         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3663         gold_assert(stub != NULL);
3664
3665         int32_t veneer_address =
3666             stub_table->address() + stub->offset() - 8 - address;
3667         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3668                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3669         // Replace with a branch to veneer (B <addr>)
3670         val = (val & 0xf0000000) | 0x0a000000
3671               | ((veneer_address >> 2) & 0x00ffffff);
3672       }
3673     else
3674       {
3675         // Preserve Rm (lowest four bits) and the condition code
3676         // (highest four bits). Other bits encode MOV PC,Rm.
3677         val = (val & 0xf000000f) | 0x01a0f000;
3678       }
3679     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3680     return This::STATUS_OKAY;
3681   }
3682
3683   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3684   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3685   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3686   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3687   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3688   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3689   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3690   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3691   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3692   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3693   static inline typename This::Status
3694   arm_grp_alu(unsigned char* view,
3695         const Sized_relobj_file<32, big_endian>* object,
3696         const Symbol_value<32>* psymval,
3697         const int group,
3698         Arm_address address,
3699         Arm_address thumb_bit,
3700         bool check_overflow)
3701   {
3702     gold_assert(group >= 0 && group < 3);
3703     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3704     Valtype* wv = reinterpret_cast<Valtype*>(view);
3705     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3706
3707     // ALU group relocations are allowed only for the ADD/SUB instructions.
3708     // (0x00800000 - ADD, 0x00400000 - SUB)
3709     const Valtype opcode = insn & 0x01e00000;
3710     if (opcode != 0x00800000 && opcode != 0x00400000)
3711       return This::STATUS_BAD_RELOC;
3712
3713     // Determine a sign for the addend.
3714     const int sign = (opcode == 0x00800000) ? 1 : -1;
3715     // shifter = rotate_imm * 2
3716     const uint32_t shifter = (insn & 0xf00) >> 7;
3717     // Initial addend value.
3718     int32_t addend = insn & 0xff;
3719     // Rotate addend right by shifter.
3720     addend = (addend >> shifter) | (addend << (32 - shifter));
3721     // Apply a sign to the added.
3722     addend *= sign;
3723
3724     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3725     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3726     // Check for overflow if required
3727     if (check_overflow
3728         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3729       return This::STATUS_OVERFLOW;
3730
3731     // Mask out the value and the ADD/SUB part of the opcode; take care
3732     // not to destroy the S bit.
3733     insn &= 0xff1ff000;
3734     // Set the opcode according to whether the value to go in the
3735     // place is negative.
3736     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3737     // Encode the offset (encoded Gn).
3738     insn |= gn;
3739
3740     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3741     return This::STATUS_OKAY;
3742   }
3743
3744   // R_ARM_LDR_PC_G0: S + A - P
3745   // R_ARM_LDR_PC_G1: S + A - P
3746   // R_ARM_LDR_PC_G2: S + A - P
3747   // R_ARM_LDR_SB_G0: S + A - B(S)
3748   // R_ARM_LDR_SB_G1: S + A - B(S)
3749   // R_ARM_LDR_SB_G2: S + A - B(S)
3750   static inline typename This::Status
3751   arm_grp_ldr(unsigned char* view,
3752         const Sized_relobj_file<32, big_endian>* object,
3753         const Symbol_value<32>* psymval,
3754         const int group,
3755         Arm_address address)
3756   {
3757     gold_assert(group >= 0 && group < 3);
3758     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3759     Valtype* wv = reinterpret_cast<Valtype*>(view);
3760     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3761
3762     const int sign = (insn & 0x00800000) ? 1 : -1;
3763     int32_t addend = (insn & 0xfff) * sign;
3764     int32_t x = (psymval->value(object, addend) - address);
3765     // Calculate the relevant G(n-1) value to obtain this stage residual.
3766     Valtype residual =
3767         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3768     if (residual >= 0x1000)
3769       return This::STATUS_OVERFLOW;
3770
3771     // Mask out the value and U bit.
3772     insn &= 0xff7ff000;
3773     // Set the U bit for non-negative values.
3774     if (x >= 0)
3775       insn |= 0x00800000;
3776     insn |= residual;
3777
3778     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3779     return This::STATUS_OKAY;
3780   }
3781
3782   // R_ARM_LDRS_PC_G0: S + A - P
3783   // R_ARM_LDRS_PC_G1: S + A - P
3784   // R_ARM_LDRS_PC_G2: S + A - P
3785   // R_ARM_LDRS_SB_G0: S + A - B(S)
3786   // R_ARM_LDRS_SB_G1: S + A - B(S)
3787   // R_ARM_LDRS_SB_G2: S + A - B(S)
3788   static inline typename This::Status
3789   arm_grp_ldrs(unsigned char* view,
3790         const Sized_relobj_file<32, big_endian>* object,
3791         const Symbol_value<32>* psymval,
3792         const int group,
3793         Arm_address address)
3794   {
3795     gold_assert(group >= 0 && group < 3);
3796     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3797     Valtype* wv = reinterpret_cast<Valtype*>(view);
3798     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3799
3800     const int sign = (insn & 0x00800000) ? 1 : -1;
3801     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3802     int32_t x = (psymval->value(object, addend) - address);
3803     // Calculate the relevant G(n-1) value to obtain this stage residual.
3804     Valtype residual =
3805         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3806    if (residual >= 0x100)
3807       return This::STATUS_OVERFLOW;
3808
3809     // Mask out the value and U bit.
3810     insn &= 0xff7ff0f0;
3811     // Set the U bit for non-negative values.
3812     if (x >= 0)
3813       insn |= 0x00800000;
3814     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3815
3816     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3817     return This::STATUS_OKAY;
3818   }
3819
3820   // R_ARM_LDC_PC_G0: S + A - P
3821   // R_ARM_LDC_PC_G1: S + A - P
3822   // R_ARM_LDC_PC_G2: S + A - P
3823   // R_ARM_LDC_SB_G0: S + A - B(S)
3824   // R_ARM_LDC_SB_G1: S + A - B(S)
3825   // R_ARM_LDC_SB_G2: S + A - B(S)
3826   static inline typename This::Status
3827   arm_grp_ldc(unsigned char* view,
3828       const Sized_relobj_file<32, big_endian>* object,
3829       const Symbol_value<32>* psymval,
3830       const int group,
3831       Arm_address address)
3832   {
3833     gold_assert(group >= 0 && group < 3);
3834     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3835     Valtype* wv = reinterpret_cast<Valtype*>(view);
3836     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3837
3838     const int sign = (insn & 0x00800000) ? 1 : -1;
3839     int32_t addend = ((insn & 0xff) << 2) * sign;
3840     int32_t x = (psymval->value(object, addend) - address);
3841     // Calculate the relevant G(n-1) value to obtain this stage residual.
3842     Valtype residual =
3843       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3844     if ((residual & 0x3) != 0 || residual >= 0x400)
3845       return This::STATUS_OVERFLOW;
3846
3847     // Mask out the value and U bit.
3848     insn &= 0xff7fff00;
3849     // Set the U bit for non-negative values.
3850     if (x >= 0)
3851       insn |= 0x00800000;
3852     insn |= (residual >> 2);
3853
3854     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3855     return This::STATUS_OKAY;
3856   }
3857 };
3858
3859 // Relocate ARM long branches.  This handles relocation types
3860 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3861 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3862 // undefined and we do not use PLT in this relocation.  In such a case,
3863 // the branch is converted into an NOP.
3864
3865 template<bool big_endian>
3866 typename Arm_relocate_functions<big_endian>::Status
3867 Arm_relocate_functions<big_endian>::arm_branch_common(
3868     unsigned int r_type,
3869     const Relocate_info<32, big_endian>* relinfo,
3870     unsigned char* view,
3871     const Sized_symbol<32>* gsym,
3872     const Arm_relobj<big_endian>* object,
3873     unsigned int r_sym,
3874     const Symbol_value<32>* psymval,
3875     Arm_address address,
3876     Arm_address thumb_bit,
3877     bool is_weakly_undefined_without_plt)
3878 {
3879   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3880   Valtype* wv = reinterpret_cast<Valtype*>(view);
3881   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3882
3883   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3884                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3885   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3886   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3887                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3888   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3889   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3890
3891   // Check that the instruction is valid.
3892   if (r_type == elfcpp::R_ARM_CALL)
3893     {
3894       if (!insn_is_uncond_bl && !insn_is_blx)
3895         return This::STATUS_BAD_RELOC;
3896     }
3897   else if (r_type == elfcpp::R_ARM_JUMP24)
3898     {
3899       if (!insn_is_b && !insn_is_cond_bl)
3900         return This::STATUS_BAD_RELOC;
3901     }
3902   else if (r_type == elfcpp::R_ARM_PLT32)
3903     {
3904       if (!insn_is_any_branch)
3905         return This::STATUS_BAD_RELOC;
3906     }
3907   else if (r_type == elfcpp::R_ARM_XPC25)
3908     {
3909       // FIXME: AAELF document IH0044C does not say much about it other
3910       // than it being obsolete.
3911       if (!insn_is_any_branch)
3912         return This::STATUS_BAD_RELOC;
3913     }
3914   else
3915     gold_unreachable();
3916
3917   // A branch to an undefined weak symbol is turned into a jump to
3918   // the next instruction unless a PLT entry will be created.
3919   // Do the same for local undefined symbols.
3920   // The jump to the next instruction is optimized as a NOP depending
3921   // on the architecture.
3922   const Target_arm<big_endian>* arm_target =
3923     Target_arm<big_endian>::default_target();
3924   if (is_weakly_undefined_without_plt)
3925     {
3926       gold_assert(!parameters->options().relocatable());
3927       Valtype cond = val & 0xf0000000U;
3928       if (arm_target->may_use_arm_nop())
3929         val = cond | 0x0320f000;
3930       else
3931         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3932       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3933       return This::STATUS_OKAY;
3934     }
3935
3936   Valtype addend = Bits<26>::sign_extend32(val << 2);
3937   Valtype branch_target = psymval->value(object, addend);
3938   int32_t branch_offset = branch_target - address;
3939
3940   // We need a stub if the branch offset is too large or if we need
3941   // to switch mode.
3942   bool may_use_blx = arm_target->may_use_v5t_interworking();
3943   Reloc_stub* stub = NULL;
3944
3945   if (!parameters->options().relocatable()
3946       && (Bits<26>::has_overflow32(branch_offset)
3947           || ((thumb_bit != 0)
3948               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3949     {
3950       Valtype unadjusted_branch_target = psymval->value(object, 0);
3951
3952       Stub_type stub_type =
3953         Reloc_stub::stub_type_for_reloc(r_type, address,
3954                                         unadjusted_branch_target,
3955                                         (thumb_bit != 0));
3956       if (stub_type != arm_stub_none)
3957         {
3958           Stub_table<big_endian>* stub_table =
3959             object->stub_table(relinfo->data_shndx);
3960           gold_assert(stub_table != NULL);
3961
3962           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3963           stub = stub_table->find_reloc_stub(stub_key);
3964           gold_assert(stub != NULL);
3965           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3966           branch_target = stub_table->address() + stub->offset() + addend;
3967           branch_offset = branch_target - address;
3968           gold_assert(!Bits<26>::has_overflow32(branch_offset));
3969         }
3970     }
3971
3972   // At this point, if we still need to switch mode, the instruction
3973   // must either be a BLX or a BL that can be converted to a BLX.
3974   if (thumb_bit != 0)
3975     {
3976       // Turn BL to BLX.
3977       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3978       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3979     }
3980
3981   val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3982   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3983   return (Bits<26>::has_overflow32(branch_offset)
3984           ? This::STATUS_OVERFLOW
3985           : This::STATUS_OKAY);
3986 }
3987
3988 // Relocate THUMB long branches.  This handles relocation types
3989 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3990 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3991 // undefined and we do not use PLT in this relocation.  In such a case,
3992 // the branch is converted into an NOP.
3993
3994 template<bool big_endian>
3995 typename Arm_relocate_functions<big_endian>::Status
3996 Arm_relocate_functions<big_endian>::thumb_branch_common(
3997     unsigned int r_type,
3998     const Relocate_info<32, big_endian>* relinfo,
3999     unsigned char* view,
4000     const Sized_symbol<32>* gsym,
4001     const Arm_relobj<big_endian>* object,
4002     unsigned int r_sym,
4003     const Symbol_value<32>* psymval,
4004     Arm_address address,
4005     Arm_address thumb_bit,
4006     bool is_weakly_undefined_without_plt)
4007 {
4008   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4009   Valtype* wv = reinterpret_cast<Valtype*>(view);
4010   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4011   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4012
4013   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4014   // into account.
4015   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4016   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4017
4018   // Check that the instruction is valid.
4019   if (r_type == elfcpp::R_ARM_THM_CALL)
4020     {
4021       if (!is_bl_insn && !is_blx_insn)
4022         return This::STATUS_BAD_RELOC;
4023     }
4024   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4025     {
4026       // This cannot be a BLX.
4027       if (!is_bl_insn)
4028         return This::STATUS_BAD_RELOC;
4029     }
4030   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4031     {
4032       // Check for Thumb to Thumb call.
4033       if (!is_blx_insn)
4034         return This::STATUS_BAD_RELOC;
4035       if (thumb_bit != 0)
4036         {
4037           gold_warning(_("%s: Thumb BLX instruction targets "
4038                          "thumb function '%s'."),
4039                          object->name().c_str(),
4040                          (gsym ? gsym->name() : "(local)"));
4041           // Convert BLX to BL.
4042           lower_insn |= 0x1000U;
4043         }
4044     }
4045   else
4046     gold_unreachable();
4047
4048   // A branch to an undefined weak symbol is turned into a jump to
4049   // the next instruction unless a PLT entry will be created.
4050   // The jump to the next instruction is optimized as a NOP.W for
4051   // Thumb-2 enabled architectures.
4052   const Target_arm<big_endian>* arm_target =
4053     Target_arm<big_endian>::default_target();
4054   if (is_weakly_undefined_without_plt)
4055     {
4056       gold_assert(!parameters->options().relocatable());
4057       if (arm_target->may_use_thumb2_nop())
4058         {
4059           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4060           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4061         }
4062       else
4063         {
4064           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4065           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4066         }
4067       return This::STATUS_OKAY;
4068     }
4069
4070   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4071   Arm_address branch_target = psymval->value(object, addend);
4072
4073   // For BLX, bit 1 of target address comes from bit 1 of base address.
4074   bool may_use_blx = arm_target->may_use_v5t_interworking();
4075   if (thumb_bit == 0 && may_use_blx)
4076     branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4077
4078   int32_t branch_offset = branch_target - address;
4079
4080   // We need a stub if the branch offset is too large or if we need
4081   // to switch mode.
4082   bool thumb2 = arm_target->using_thumb2();
4083   if (!parameters->options().relocatable()
4084       && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4085           || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4086           || ((thumb_bit == 0)
4087               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4088                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4089     {
4090       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4091
4092       Stub_type stub_type =
4093         Reloc_stub::stub_type_for_reloc(r_type, address,
4094                                         unadjusted_branch_target,
4095                                         (thumb_bit != 0));
4096
4097       if (stub_type != arm_stub_none)
4098         {
4099           Stub_table<big_endian>* stub_table =
4100             object->stub_table(relinfo->data_shndx);
4101           gold_assert(stub_table != NULL);
4102
4103           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4104           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4105           gold_assert(stub != NULL);
4106           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4107           branch_target = stub_table->address() + stub->offset() + addend;
4108           if (thumb_bit == 0 && may_use_blx)
4109             branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4110           branch_offset = branch_target - address;
4111         }
4112     }
4113
4114   // At this point, if we still need to switch mode, the instruction
4115   // must either be a BLX or a BL that can be converted to a BLX.
4116   if (thumb_bit == 0)
4117     {
4118       gold_assert(may_use_blx
4119                   && (r_type == elfcpp::R_ARM_THM_CALL
4120                       || r_type == elfcpp::R_ARM_THM_XPC22));
4121       // Make sure this is a BLX.
4122       lower_insn &= ~0x1000U;
4123     }
4124   else
4125     {
4126       // Make sure this is a BL.
4127       lower_insn |= 0x1000U;
4128     }
4129
4130   // For a BLX instruction, make sure that the relocation is rounded up
4131   // to a word boundary.  This follows the semantics of the instruction
4132   // which specifies that bit 1 of the target address will come from bit
4133   // 1 of the base address.
4134   if ((lower_insn & 0x5000U) == 0x4000U)
4135     gold_assert((branch_offset & 3) == 0);
4136
4137   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4138   // We use the Thumb-2 encoding, which is safe even if dealing with
4139   // a Thumb-1 instruction by virtue of our overflow check above.  */
4140   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4141   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4142
4143   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4144   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4145
4146   gold_assert(!Bits<25>::has_overflow32(branch_offset));
4147
4148   return ((thumb2
4149            ? Bits<25>::has_overflow32(branch_offset)
4150            : Bits<23>::has_overflow32(branch_offset))
4151           ? This::STATUS_OVERFLOW
4152           : This::STATUS_OKAY);
4153 }
4154
4155 // Relocate THUMB-2 long conditional branches.
4156 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4157 // undefined and we do not use PLT in this relocation.  In such a case,
4158 // the branch is converted into an NOP.
4159
4160 template<bool big_endian>
4161 typename Arm_relocate_functions<big_endian>::Status
4162 Arm_relocate_functions<big_endian>::thm_jump19(
4163     unsigned char* view,
4164     const Arm_relobj<big_endian>* object,
4165     const Symbol_value<32>* psymval,
4166     Arm_address address,
4167     Arm_address thumb_bit)
4168 {
4169   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4170   Valtype* wv = reinterpret_cast<Valtype*>(view);
4171   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4172   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4173   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4174
4175   Arm_address branch_target = psymval->value(object, addend);
4176   int32_t branch_offset = branch_target - address;
4177
4178   // ??? Should handle interworking?  GCC might someday try to
4179   // use this for tail calls.
4180   // FIXME: We do support thumb entry to PLT yet.
4181   if (thumb_bit == 0)
4182     {
4183       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4184       return This::STATUS_BAD_RELOC;
4185     }
4186
4187   // Put RELOCATION back into the insn.
4188   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4189   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4190
4191   // Put the relocated value back in the object file:
4192   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4193   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4194
4195   return (Bits<21>::has_overflow32(branch_offset)
4196           ? This::STATUS_OVERFLOW
4197           : This::STATUS_OKAY);
4198 }
4199
4200 // Get the GOT section, creating it if necessary.
4201
4202 template<bool big_endian>
4203 Arm_output_data_got<big_endian>*
4204 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4205 {
4206   if (this->got_ == NULL)
4207     {
4208       gold_assert(symtab != NULL && layout != NULL);
4209
4210       // When using -z now, we can treat .got as a relro section.
4211       // Without -z now, it is modified after program startup by lazy
4212       // PLT relocations.
4213       bool is_got_relro = parameters->options().now();
4214       Output_section_order got_order = (is_got_relro
4215                                         ? ORDER_RELRO_LAST
4216                                         : ORDER_DATA);
4217
4218       // Unlike some targets (.e.g x86), ARM does not use separate .got and
4219       // .got.plt sections in output.  The output .got section contains both
4220       // PLT and non-PLT GOT entries.
4221       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4222
4223       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4224                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4225                                       this->got_, got_order, is_got_relro);
4226
4227       // The old GNU linker creates a .got.plt section.  We just
4228       // create another set of data in the .got section.  Note that we
4229       // always create a PLT if we create a GOT, although the PLT
4230       // might be empty.
4231       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4232       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4233                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4234                                       this->got_plt_, got_order, is_got_relro);
4235
4236       // The first three entries are reserved.
4237       this->got_plt_->set_current_data_size(3 * 4);
4238
4239       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4240       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4241                                     Symbol_table::PREDEFINED,
4242                                     this->got_plt_,
4243                                     0, 0, elfcpp::STT_OBJECT,
4244                                     elfcpp::STB_LOCAL,
4245                                     elfcpp::STV_HIDDEN, 0,
4246                                     false, false);
4247     }
4248   return this->got_;
4249 }
4250
4251 // Get the dynamic reloc section, creating it if necessary.
4252
4253 template<bool big_endian>
4254 typename Target_arm<big_endian>::Reloc_section*
4255 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4256 {
4257   if (this->rel_dyn_ == NULL)
4258     {
4259       gold_assert(layout != NULL);
4260       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4261       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4262                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4263                                       ORDER_DYNAMIC_RELOCS, false);
4264     }
4265   return this->rel_dyn_;
4266 }
4267
4268 // Insn_template methods.
4269
4270 // Return byte size of an instruction template.
4271
4272 size_t
4273 Insn_template::size() const
4274 {
4275   switch (this->type())
4276     {
4277     case THUMB16_TYPE:
4278     case THUMB16_SPECIAL_TYPE:
4279       return 2;
4280     case ARM_TYPE:
4281     case THUMB32_TYPE:
4282     case DATA_TYPE:
4283       return 4;
4284     default:
4285       gold_unreachable();
4286     }
4287 }
4288
4289 // Return alignment of an instruction template.
4290
4291 unsigned
4292 Insn_template::alignment() const
4293 {
4294   switch (this->type())
4295     {
4296     case THUMB16_TYPE:
4297     case THUMB16_SPECIAL_TYPE:
4298     case THUMB32_TYPE:
4299       return 2;
4300     case ARM_TYPE:
4301     case DATA_TYPE:
4302       return 4;
4303     default:
4304       gold_unreachable();
4305     }
4306 }
4307
4308 // Stub_template methods.
4309
4310 Stub_template::Stub_template(
4311     Stub_type type, const Insn_template* insns,
4312      size_t insn_count)
4313   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4314     entry_in_thumb_mode_(false), relocs_()
4315 {
4316   off_t offset = 0;
4317
4318   // Compute byte size and alignment of stub template.
4319   for (size_t i = 0; i < insn_count; i++)
4320     {
4321       unsigned insn_alignment = insns[i].alignment();
4322       size_t insn_size = insns[i].size();
4323       gold_assert((offset & (insn_alignment - 1)) == 0);
4324       this->alignment_ = std::max(this->alignment_, insn_alignment);
4325       switch (insns[i].type())
4326         {
4327         case Insn_template::THUMB16_TYPE:
4328         case Insn_template::THUMB16_SPECIAL_TYPE:
4329           if (i == 0)
4330             this->entry_in_thumb_mode_ = true;
4331           break;
4332
4333         case Insn_template::THUMB32_TYPE:
4334           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4335             this->relocs_.push_back(Reloc(i, offset));
4336           if (i == 0)
4337             this->entry_in_thumb_mode_ = true;
4338           break;
4339
4340         case Insn_template::ARM_TYPE:
4341           // Handle cases where the target is encoded within the
4342           // instruction.
4343           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4344             this->relocs_.push_back(Reloc(i, offset));
4345           break;
4346
4347         case Insn_template::DATA_TYPE:
4348           // Entry point cannot be data.
4349           gold_assert(i != 0);
4350           this->relocs_.push_back(Reloc(i, offset));
4351           break;
4352
4353         default:
4354           gold_unreachable();
4355         }
4356       offset += insn_size;
4357     }
4358   this->size_ = offset;
4359 }
4360
4361 // Stub methods.
4362
4363 // Template to implement do_write for a specific target endianness.
4364
4365 template<bool big_endian>
4366 void inline
4367 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4368 {
4369   const Stub_template* stub_template = this->stub_template();
4370   const Insn_template* insns = stub_template->insns();
4371
4372   // FIXME:  We do not handle BE8 encoding yet.
4373   unsigned char* pov = view;
4374   for (size_t i = 0; i < stub_template->insn_count(); i++)
4375     {
4376       switch (insns[i].type())
4377         {
4378         case Insn_template::THUMB16_TYPE:
4379           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4380           break;
4381         case Insn_template::THUMB16_SPECIAL_TYPE:
4382           elfcpp::Swap<16, big_endian>::writeval(
4383               pov,
4384               this->thumb16_special(i));
4385           break;
4386         case Insn_template::THUMB32_TYPE:
4387           {
4388             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4389             uint32_t lo = insns[i].data() & 0xffff;
4390             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4391             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4392           }
4393           break;
4394         case Insn_template::ARM_TYPE:
4395         case Insn_template::DATA_TYPE:
4396           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4397           break;
4398         default:
4399           gold_unreachable();
4400         }
4401       pov += insns[i].size();
4402     }
4403   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4404 }
4405
4406 // Reloc_stub::Key methods.
4407
4408 // Dump a Key as a string for debugging.
4409
4410 std::string
4411 Reloc_stub::Key::name() const
4412 {
4413   if (this->r_sym_ == invalid_index)
4414     {
4415       // Global symbol key name
4416       // <stub-type>:<symbol name>:<addend>.
4417       const std::string sym_name = this->u_.symbol->name();
4418       // We need to print two hex number and two colons.  So just add 100 bytes
4419       // to the symbol name size.
4420       size_t len = sym_name.size() + 100;
4421       char* buffer = new char[len];
4422       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4423                        sym_name.c_str(), this->addend_);
4424       gold_assert(c > 0 && c < static_cast<int>(len));
4425       delete[] buffer;
4426       return std::string(buffer);
4427     }
4428   else
4429     {
4430       // local symbol key name
4431       // <stub-type>:<object>:<r_sym>:<addend>.
4432       const size_t len = 200;
4433       char buffer[len];
4434       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4435                        this->u_.relobj, this->r_sym_, this->addend_);
4436       gold_assert(c > 0 && c < static_cast<int>(len));
4437       return std::string(buffer);
4438     }
4439 }
4440
4441 // Reloc_stub methods.
4442
4443 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4444 // LOCATION to DESTINATION.
4445 // This code is based on the arm_type_of_stub function in
4446 // bfd/elf32-arm.c.  We have changed the interface a little to keep the Stub
4447 // class simple.
4448
4449 Stub_type
4450 Reloc_stub::stub_type_for_reloc(
4451    unsigned int r_type,
4452    Arm_address location,
4453    Arm_address destination,
4454    bool target_is_thumb)
4455 {
4456   Stub_type stub_type = arm_stub_none;
4457
4458   // This is a bit ugly but we want to avoid using a templated class for
4459   // big and little endianities.
4460   bool may_use_blx;
4461   bool should_force_pic_veneer;
4462   bool thumb2;
4463   bool thumb_only;
4464   if (parameters->target().is_big_endian())
4465     {
4466       const Target_arm<true>* big_endian_target =
4467         Target_arm<true>::default_target();
4468       may_use_blx = big_endian_target->may_use_v5t_interworking();
4469       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4470       thumb2 = big_endian_target->using_thumb2();
4471       thumb_only = big_endian_target->using_thumb_only();
4472     }
4473   else
4474     {
4475       const Target_arm<false>* little_endian_target =
4476         Target_arm<false>::default_target();
4477       may_use_blx = little_endian_target->may_use_v5t_interworking();
4478       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4479       thumb2 = little_endian_target->using_thumb2();
4480       thumb_only = little_endian_target->using_thumb_only();
4481     }
4482
4483   int64_t branch_offset;
4484   bool output_is_position_independent =
4485       parameters->options().output_is_position_independent();
4486   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4487     {
4488       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4489       // base address (instruction address + 4).
4490       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4491         destination = Bits<32>::bit_select32(destination, location, 0x2);
4492       branch_offset = static_cast<int64_t>(destination) - location;
4493
4494       // Handle cases where:
4495       // - this call goes too far (different Thumb/Thumb2 max
4496       //   distance)
4497       // - it's a Thumb->Arm call and blx is not available, or it's a
4498       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4499       if ((!thumb2
4500             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4501                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4502           || (thumb2
4503               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4504                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4505           || ((!target_is_thumb)
4506               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4507                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4508         {
4509           if (target_is_thumb)
4510             {
4511               // Thumb to thumb.
4512               if (!thumb_only)
4513                 {
4514                   stub_type = (output_is_position_independent
4515                                || should_force_pic_veneer)
4516                     // PIC stubs.
4517                     ? ((may_use_blx
4518                         && (r_type == elfcpp::R_ARM_THM_CALL))
4519                        // V5T and above. Stub starts with ARM code, so
4520                        // we must be able to switch mode before
4521                        // reaching it, which is only possible for 'bl'
4522                        // (ie R_ARM_THM_CALL relocation).
4523                        ? arm_stub_long_branch_any_thumb_pic
4524                        // On V4T, use Thumb code only.
4525                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4526
4527                     // non-PIC stubs.
4528                     : ((may_use_blx
4529                         && (r_type == elfcpp::R_ARM_THM_CALL))
4530                        ? arm_stub_long_branch_any_any // V5T and above.
4531                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4532                 }
4533               else
4534                 {
4535                   stub_type = (output_is_position_independent
4536                                || should_force_pic_veneer)
4537                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4538                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4539                 }
4540             }
4541           else
4542             {
4543               // Thumb to arm.
4544
4545               // FIXME: We should check that the input section is from an
4546               // object that has interwork enabled.
4547
4548               stub_type = (output_is_position_independent
4549                            || should_force_pic_veneer)
4550                 // PIC stubs.
4551                 ? ((may_use_blx
4552                     && (r_type == elfcpp::R_ARM_THM_CALL))
4553                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4554                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4555
4556                 // non-PIC stubs.
4557                 : ((may_use_blx
4558                     && (r_type == elfcpp::R_ARM_THM_CALL))
4559                    ? arm_stub_long_branch_any_any       // V5T and above.
4560                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4561
4562               // Handle v4t short branches.
4563               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4564                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4565                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4566                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4567             }
4568         }
4569     }
4570   else if (r_type == elfcpp::R_ARM_CALL
4571            || r_type == elfcpp::R_ARM_JUMP24
4572            || r_type == elfcpp::R_ARM_PLT32)
4573     {
4574       branch_offset = static_cast<int64_t>(destination) - location;
4575       if (target_is_thumb)
4576         {
4577           // Arm to thumb.
4578
4579           // FIXME: We should check that the input section is from an
4580           // object that has interwork enabled.
4581
4582           // We have an extra 2-bytes reach because of
4583           // the mode change (bit 24 (H) of BLX encoding).
4584           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4585               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4586               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4587               || (r_type == elfcpp::R_ARM_JUMP24)
4588               || (r_type == elfcpp::R_ARM_PLT32))
4589             {
4590               stub_type = (output_is_position_independent
4591                            || should_force_pic_veneer)
4592                 // PIC stubs.
4593                 ? (may_use_blx
4594                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4595                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4596
4597                 // non-PIC stubs.
4598                 : (may_use_blx
4599                    ? arm_stub_long_branch_any_any       // V5T and above.
4600                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4601             }
4602         }
4603       else
4604         {
4605           // Arm to arm.
4606           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4607               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4608             {
4609               stub_type = (output_is_position_independent
4610                            || should_force_pic_veneer)
4611                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4612                 : arm_stub_long_branch_any_any;         /// non-PIC.
4613             }
4614         }
4615     }
4616
4617   return stub_type;
4618 }
4619
4620 // Cortex_a8_stub methods.
4621
4622 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4623 // I is the position of the instruction template in the stub template.
4624
4625 uint16_t
4626 Cortex_a8_stub::do_thumb16_special(size_t i)
4627 {
4628   // The only use of this is to copy condition code from a conditional
4629   // branch being worked around to the corresponding conditional branch in
4630   // to the stub.
4631   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4632               && i == 0);
4633   uint16_t data = this->stub_template()->insns()[i].data();
4634   gold_assert((data & 0xff00U) == 0xd000U);
4635   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4636   return data;
4637 }
4638
4639 // Stub_factory methods.
4640
4641 Stub_factory::Stub_factory()
4642 {
4643   // The instruction template sequences are declared as static
4644   // objects and initialized first time the constructor runs.
4645
4646   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4647   // to reach the stub if necessary.
4648   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4649     {
4650       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4651       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4652                                                 // dcd   R_ARM_ABS32(X)
4653     };
4654
4655   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4656   // available.
4657   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4658     {
4659       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4660       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4661       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4662                                                 // dcd   R_ARM_ABS32(X)
4663     };
4664
4665   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4666   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4667     {
4668       Insn_template::thumb16_insn(0xb401),      // push {r0}
4669       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4670       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4671       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4672       Insn_template::thumb16_insn(0x4760),      // bx   ip
4673       Insn_template::thumb16_insn(0xbf00),      // nop
4674       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4675                                                 // dcd  R_ARM_ABS32(X)
4676     };
4677
4678   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4679   // allowed.
4680   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4681     {
4682       Insn_template::thumb16_insn(0x4778),      // bx   pc
4683       Insn_template::thumb16_insn(0x46c0),      // nop
4684       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4685       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4686       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4687                                                 // dcd  R_ARM_ABS32(X)
4688     };
4689
4690   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4691   // available.
4692   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4693     {
4694       Insn_template::thumb16_insn(0x4778),      // bx   pc
4695       Insn_template::thumb16_insn(0x46c0),      // nop
4696       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4697       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4698                                                 // dcd   R_ARM_ABS32(X)
4699     };
4700
4701   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4702   // one, when the destination is close enough.
4703   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4704     {
4705       Insn_template::thumb16_insn(0x4778),              // bx   pc
4706       Insn_template::thumb16_insn(0x46c0),              // nop
4707       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4708     };
4709
4710   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4711   // blx to reach the stub if necessary.
4712   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4713     {
4714       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4715       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4716       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4717                                                 // dcd   R_ARM_REL32(X-4)
4718     };
4719
4720   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4721   // blx to reach the stub if necessary.  We can not add into pc;
4722   // it is not guaranteed to mode switch (different in ARMv6 and
4723   // ARMv7).
4724   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4725     {
4726       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4727       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4728       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4729       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4730                                                 // dcd   R_ARM_REL32(X)
4731     };
4732
4733   // V4T ARM -> ARM long branch stub, PIC.
4734   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4735     {
4736       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4737       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4738       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4739       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4740                                                 // dcd   R_ARM_REL32(X)
4741     };
4742
4743   // V4T Thumb -> ARM long branch stub, PIC.
4744   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4745     {
4746       Insn_template::thumb16_insn(0x4778),      // bx   pc
4747       Insn_template::thumb16_insn(0x46c0),      // nop
4748       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4749       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4750       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4751                                                 // dcd  R_ARM_REL32(X)
4752     };
4753
4754   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4755   // architectures.
4756   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4757     {
4758       Insn_template::thumb16_insn(0xb401),      // push {r0}
4759       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4760       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4761       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4762       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4763       Insn_template::thumb16_insn(0x4760),      // bx   ip
4764       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4765                                                 // dcd  R_ARM_REL32(X)
4766     };
4767
4768   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4769   // allowed.
4770   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4771     {
4772       Insn_template::thumb16_insn(0x4778),      // bx   pc
4773       Insn_template::thumb16_insn(0x46c0),      // nop
4774       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4775       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4776       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4777       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4778                                                 // dcd  R_ARM_REL32(X)
4779     };
4780
4781   // Cortex-A8 erratum-workaround stubs.
4782
4783   // Stub used for conditional branches (which may be beyond +/-1MB away,
4784   // so we can't use a conditional branch to reach this stub).
4785
4786   // original code:
4787   //
4788   //    b<cond> X
4789   // after:
4790   //
4791   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4792     {
4793       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4794       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4795       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4796                                                         //      b.w X
4797     };
4798
4799   // Stub used for b.w and bl.w instructions.
4800
4801   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4802     {
4803       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4804     };
4805
4806   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4807     {
4808       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4809     };
4810
4811   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4812   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4813   // the real destination using an ARM-mode branch.
4814   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4815     {
4816       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4817     };
4818
4819   // Stub used to provide an interworking for R_ARM_V4BX relocation
4820   // (bx r[n] instruction).
4821   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4822     {
4823       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4824       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4825       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4826     };
4827
4828   // Fill in the stub template look-up table.  Stub templates are constructed
4829   // per instance of Stub_factory for fast look-up without locking
4830   // in a thread-enabled environment.
4831
4832   this->stub_templates_[arm_stub_none] =
4833     new Stub_template(arm_stub_none, NULL, 0);
4834
4835 #define DEF_STUB(x)     \
4836   do \
4837     { \
4838       size_t array_size \
4839         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4840       Stub_type type = arm_stub_##x; \
4841       this->stub_templates_[type] = \
4842         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4843     } \
4844   while (0);
4845
4846   DEF_STUBS
4847 #undef DEF_STUB
4848 }
4849
4850 // Stub_table methods.
4851
4852 // Remove all Cortex-A8 stub.
4853
4854 template<bool big_endian>
4855 void
4856 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4857 {
4858   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4859        p != this->cortex_a8_stubs_.end();
4860        ++p)
4861     delete p->second;
4862   this->cortex_a8_stubs_.clear();
4863 }
4864
4865 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4866
4867 template<bool big_endian>
4868 void
4869 Stub_table<big_endian>::relocate_stub(
4870     Stub* stub,
4871     const Relocate_info<32, big_endian>* relinfo,
4872     Target_arm<big_endian>* arm_target,
4873     Output_section* output_section,
4874     unsigned char* view,
4875     Arm_address address,
4876     section_size_type view_size)
4877 {
4878   const Stub_template* stub_template = stub->stub_template();
4879   if (stub_template->reloc_count() != 0)
4880     {
4881       // Adjust view to cover the stub only.
4882       section_size_type offset = stub->offset();
4883       section_size_type stub_size = stub_template->size();
4884       gold_assert(offset + stub_size <= view_size);
4885
4886       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4887                                 address + offset, stub_size);
4888     }
4889 }
4890
4891 // Relocate all stubs in this stub table.
4892
4893 template<bool big_endian>
4894 void
4895 Stub_table<big_endian>::relocate_stubs(
4896     const Relocate_info<32, big_endian>* relinfo,
4897     Target_arm<big_endian>* arm_target,
4898     Output_section* output_section,
4899     unsigned char* view,
4900     Arm_address address,
4901     section_size_type view_size)
4902 {
4903   // If we are passed a view bigger than the stub table's.  we need to
4904   // adjust the view.
4905   gold_assert(address == this->address()
4906               && (view_size
4907                   == static_cast<section_size_type>(this->data_size())));
4908
4909   // Relocate all relocation stubs.
4910   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4911       p != this->reloc_stubs_.end();
4912       ++p)
4913     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4914                         address, view_size);
4915
4916   // Relocate all Cortex-A8 stubs.
4917   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4918        p != this->cortex_a8_stubs_.end();
4919        ++p)
4920     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4921                         address, view_size);
4922
4923   // Relocate all ARM V4BX stubs.
4924   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4925        p != this->arm_v4bx_stubs_.end();
4926        ++p)
4927     {
4928       if (*p != NULL)
4929         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4930                             address, view_size);
4931     }
4932 }
4933
4934 // Write out the stubs to file.
4935
4936 template<bool big_endian>
4937 void
4938 Stub_table<big_endian>::do_write(Output_file* of)
4939 {
4940   off_t offset = this->offset();
4941   const section_size_type oview_size =
4942     convert_to_section_size_type(this->data_size());
4943   unsigned char* const oview = of->get_output_view(offset, oview_size);
4944
4945   // Write relocation stubs.
4946   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4947       p != this->reloc_stubs_.end();
4948       ++p)
4949     {
4950       Reloc_stub* stub = p->second;
4951       Arm_address address = this->address() + stub->offset();
4952       gold_assert(address
4953                   == align_address(address,
4954                                    stub->stub_template()->alignment()));
4955       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4956                   big_endian);
4957     }
4958
4959   // Write Cortex-A8 stubs.
4960   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4961        p != this->cortex_a8_stubs_.end();
4962        ++p)
4963     {
4964       Cortex_a8_stub* stub = p->second;
4965       Arm_address address = this->address() + stub->offset();
4966       gold_assert(address
4967                   == align_address(address,
4968                                    stub->stub_template()->alignment()));
4969       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4970                   big_endian);
4971     }
4972
4973   // Write ARM V4BX relocation stubs.
4974   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4975        p != this->arm_v4bx_stubs_.end();
4976        ++p)
4977     {
4978       if (*p == NULL)
4979         continue;
4980
4981       Arm_address address = this->address() + (*p)->offset();
4982       gold_assert(address
4983                   == align_address(address,
4984                                    (*p)->stub_template()->alignment()));
4985       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4986                   big_endian);
4987     }
4988
4989   of->write_output_view(this->offset(), oview_size, oview);
4990 }
4991
4992 // Update the data size and address alignment of the stub table at the end
4993 // of a relaxation pass.   Return true if either the data size or the
4994 // alignment changed in this relaxation pass.
4995
4996 template<bool big_endian>
4997 bool
4998 Stub_table<big_endian>::update_data_size_and_addralign()
4999 {
5000   // Go over all stubs in table to compute data size and address alignment.
5001   off_t size = this->reloc_stubs_size_;
5002   unsigned addralign = this->reloc_stubs_addralign_;
5003
5004   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5005        p != this->cortex_a8_stubs_.end();
5006        ++p)
5007     {
5008       const Stub_template* stub_template = p->second->stub_template();
5009       addralign = std::max(addralign, stub_template->alignment());
5010       size = (align_address(size, stub_template->alignment())
5011               + stub_template->size());
5012     }
5013
5014   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5015        p != this->arm_v4bx_stubs_.end();
5016        ++p)
5017     {
5018       if (*p == NULL)
5019         continue;
5020
5021       const Stub_template* stub_template = (*p)->stub_template();
5022       addralign = std::max(addralign, stub_template->alignment());
5023       size = (align_address(size, stub_template->alignment())
5024               + stub_template->size());
5025     }
5026
5027   // Check if either data size or alignment changed in this pass.
5028   // Update prev_data_size_ and prev_addralign_.  These will be used
5029   // as the current data size and address alignment for the next pass.
5030   bool changed = size != this->prev_data_size_;
5031   this->prev_data_size_ = size;
5032
5033   if (addralign != this->prev_addralign_)
5034     changed = true;
5035   this->prev_addralign_ = addralign;
5036
5037   return changed;
5038 }
5039
5040 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5041 // table.  It also marks all input sections needing Cortex-A8 workaround.
5042
5043 template<bool big_endian>
5044 void
5045 Stub_table<big_endian>::finalize_stubs()
5046 {
5047   off_t off = this->reloc_stubs_size_;
5048   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5049        p != this->cortex_a8_stubs_.end();
5050        ++p)
5051     {
5052       Cortex_a8_stub* stub = p->second;
5053       const Stub_template* stub_template = stub->stub_template();
5054       uint64_t stub_addralign = stub_template->alignment();
5055       off = align_address(off, stub_addralign);
5056       stub->set_offset(off);
5057       off += stub_template->size();
5058
5059       // Mark input section so that we can determine later if a code section
5060       // needs the Cortex-A8 workaround quickly.
5061       Arm_relobj<big_endian>* arm_relobj =
5062         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5063       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5064     }
5065
5066   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5067       p != this->arm_v4bx_stubs_.end();
5068       ++p)
5069     {
5070       if (*p == NULL)
5071         continue;
5072
5073       const Stub_template* stub_template = (*p)->stub_template();
5074       uint64_t stub_addralign = stub_template->alignment();
5075       off = align_address(off, stub_addralign);
5076       (*p)->set_offset(off);
5077       off += stub_template->size();
5078     }
5079
5080   gold_assert(off <= this->prev_data_size_);
5081 }
5082
5083 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5084 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5085 // of the address range seen by the linker.
5086
5087 template<bool big_endian>
5088 void
5089 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5090     Target_arm<big_endian>* arm_target,
5091     unsigned char* view,
5092     Arm_address view_address,
5093     section_size_type view_size)
5094 {
5095   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5096   for (Cortex_a8_stub_list::const_iterator p =
5097          this->cortex_a8_stubs_.lower_bound(view_address);
5098        ((p != this->cortex_a8_stubs_.end())
5099         && (p->first < (view_address + view_size)));
5100        ++p)
5101     {
5102       // We do not store the THUMB bit in the LSB of either the branch address
5103       // or the stub offset.  There is no need to strip the LSB.
5104       Arm_address branch_address = p->first;
5105       const Cortex_a8_stub* stub = p->second;
5106       Arm_address stub_address = this->address() + stub->offset();
5107
5108       // Offset of the branch instruction relative to this view.
5109       section_size_type offset =
5110         convert_to_section_size_type(branch_address - view_address);
5111       gold_assert((offset + 4) <= view_size);
5112
5113       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5114                                              view + offset, branch_address);
5115     }
5116 }
5117
5118 // Arm_input_section methods.
5119
5120 // Initialize an Arm_input_section.
5121
5122 template<bool big_endian>
5123 void
5124 Arm_input_section<big_endian>::init()
5125 {
5126   Relobj* relobj = this->relobj();
5127   unsigned int shndx = this->shndx();
5128
5129   // We have to cache original size, alignment and contents to avoid locking
5130   // the original file.
5131   this->original_addralign_ =
5132     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5133
5134   // This is not efficient but we expect only a small number of relaxed
5135   // input sections for stubs.
5136   section_size_type section_size;
5137   const unsigned char* section_contents =
5138     relobj->section_contents(shndx, &section_size, false);
5139   this->original_size_ =
5140     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5141
5142   gold_assert(this->original_contents_ == NULL);
5143   this->original_contents_ = new unsigned char[section_size];
5144   memcpy(this->original_contents_, section_contents, section_size);
5145
5146   // We want to make this look like the original input section after
5147   // output sections are finalized.
5148   Output_section* os = relobj->output_section(shndx);
5149   off_t offset = relobj->output_section_offset(shndx);
5150   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5151   this->set_address(os->address() + offset);
5152   this->set_file_offset(os->offset() + offset);
5153
5154   this->set_current_data_size(this->original_size_);
5155   this->finalize_data_size();
5156 }
5157
5158 template<bool big_endian>
5159 void
5160 Arm_input_section<big_endian>::do_write(Output_file* of)
5161 {
5162   // We have to write out the original section content.
5163   gold_assert(this->original_contents_ != NULL);
5164   of->write(this->offset(), this->original_contents_,
5165             this->original_size_);
5166
5167   // If this owns a stub table and it is not empty, write it.
5168   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5169     this->stub_table_->write(of);
5170 }
5171
5172 // Finalize data size.
5173
5174 template<bool big_endian>
5175 void
5176 Arm_input_section<big_endian>::set_final_data_size()
5177 {
5178   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5179
5180   if (this->is_stub_table_owner())
5181     {
5182       this->stub_table_->finalize_data_size();
5183       off = align_address(off, this->stub_table_->addralign());
5184       off += this->stub_table_->data_size();
5185     }
5186   this->set_data_size(off);
5187 }
5188
5189 // Reset address and file offset.
5190
5191 template<bool big_endian>
5192 void
5193 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5194 {
5195   // Size of the original input section contents.
5196   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5197
5198   // If this is a stub table owner, account for the stub table size.
5199   if (this->is_stub_table_owner())
5200     {
5201       Stub_table<big_endian>* stub_table = this->stub_table_;
5202
5203       // Reset the stub table's address and file offset.  The
5204       // current data size for child will be updated after that.
5205       stub_table_->reset_address_and_file_offset();
5206       off = align_address(off, stub_table_->addralign());
5207       off += stub_table->current_data_size();
5208     }
5209
5210   this->set_current_data_size(off);
5211 }
5212
5213 // Arm_exidx_cantunwind methods.
5214
5215 // Write this to Output file OF for a fixed endianness.
5216
5217 template<bool big_endian>
5218 void
5219 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5220 {
5221   off_t offset = this->offset();
5222   const section_size_type oview_size = 8;
5223   unsigned char* const oview = of->get_output_view(offset, oview_size);
5224
5225   Output_section* os = this->relobj_->output_section(this->shndx_);
5226   gold_assert(os != NULL);
5227
5228   Arm_relobj<big_endian>* arm_relobj =
5229     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5230   Arm_address output_offset =
5231     arm_relobj->get_output_section_offset(this->shndx_);
5232   Arm_address section_start;
5233   section_size_type section_size;
5234
5235   // Find out the end of the text section referred by this.
5236   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5237     {
5238       section_start = os->address() + output_offset;
5239       const Arm_exidx_input_section* exidx_input_section =
5240         arm_relobj->exidx_input_section_by_link(this->shndx_);
5241       gold_assert(exidx_input_section != NULL);
5242       section_size =
5243         convert_to_section_size_type(exidx_input_section->text_size());
5244     }
5245   else
5246     {
5247       // Currently this only happens for a relaxed section.
5248       const Output_relaxed_input_section* poris =
5249         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5250       gold_assert(poris != NULL);
5251       section_start = poris->address();
5252       section_size = convert_to_section_size_type(poris->data_size());
5253     }
5254
5255   // We always append this to the end of an EXIDX section.
5256   Arm_address output_address = section_start + section_size;
5257
5258   // Write out the entry.  The first word either points to the beginning
5259   // or after the end of a text section.  The second word is the special
5260   // EXIDX_CANTUNWIND value.
5261   uint32_t prel31_offset = output_address - this->address();
5262   if (Bits<31>::has_overflow32(offset))
5263     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5264   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5265                                                    prel31_offset & 0x7fffffffU);
5266   elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5267                                                    elfcpp::EXIDX_CANTUNWIND);
5268
5269   of->write_output_view(this->offset(), oview_size, oview);
5270 }
5271
5272 // Arm_exidx_merged_section methods.
5273
5274 // Constructor for Arm_exidx_merged_section.
5275 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5276 // SECTION_OFFSET_MAP points to a section offset map describing how
5277 // parts of the input section are mapped to output.  DELETED_BYTES is
5278 // the number of bytes deleted from the EXIDX input section.
5279
5280 Arm_exidx_merged_section::Arm_exidx_merged_section(
5281     const Arm_exidx_input_section& exidx_input_section,
5282     const Arm_exidx_section_offset_map& section_offset_map,
5283     uint32_t deleted_bytes)
5284   : Output_relaxed_input_section(exidx_input_section.relobj(),
5285                                  exidx_input_section.shndx(),
5286                                  exidx_input_section.addralign()),
5287     exidx_input_section_(exidx_input_section),
5288     section_offset_map_(section_offset_map)
5289 {
5290   // If we retain or discard the whole EXIDX input section,  we would
5291   // not be here.
5292   gold_assert(deleted_bytes != 0
5293               && deleted_bytes != this->exidx_input_section_.size());
5294
5295   // Fix size here so that we do not need to implement set_final_data_size.
5296   uint32_t size = exidx_input_section.size() - deleted_bytes;
5297   this->set_data_size(size);
5298   this->fix_data_size();
5299
5300   // Allocate buffer for section contents and build contents.
5301   this->section_contents_ = new unsigned char[size];
5302 }
5303
5304 // Build the contents of a merged EXIDX output section.
5305
5306 void
5307 Arm_exidx_merged_section::build_contents(
5308     const unsigned char* original_contents,
5309     section_size_type original_size)
5310 {
5311   // Go over spans of input offsets and write only those that are not
5312   // discarded.
5313   section_offset_type in_start = 0;
5314   section_offset_type out_start = 0;
5315   section_offset_type in_max =
5316     convert_types<section_offset_type>(original_size);
5317   section_offset_type out_max =
5318     convert_types<section_offset_type>(this->data_size());
5319   for (Arm_exidx_section_offset_map::const_iterator p =
5320         this->section_offset_map_.begin();
5321       p != this->section_offset_map_.end();
5322       ++p)
5323     {
5324       section_offset_type in_end = p->first;
5325       gold_assert(in_end >= in_start);
5326       section_offset_type out_end = p->second;
5327       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5328       if (out_end != -1)
5329         {
5330           size_t out_chunk_size =
5331             convert_types<size_t>(out_end - out_start + 1);
5332
5333           gold_assert(out_chunk_size == in_chunk_size
5334                       && in_end < in_max && out_end < out_max);
5335
5336           memcpy(this->section_contents_ + out_start,
5337                  original_contents + in_start,
5338                  out_chunk_size);
5339           out_start += out_chunk_size;
5340         }
5341       in_start += in_chunk_size;
5342     }
5343 }
5344
5345 // Given an input OBJECT, an input section index SHNDX within that
5346 // object, and an OFFSET relative to the start of that input
5347 // section, return whether or not the corresponding offset within
5348 // the output section is known.  If this function returns true, it
5349 // sets *POUTPUT to the output offset.  The value -1 indicates that
5350 // this input offset is being discarded.
5351
5352 bool
5353 Arm_exidx_merged_section::do_output_offset(
5354     const Relobj* relobj,
5355     unsigned int shndx,
5356     section_offset_type offset,
5357     section_offset_type* poutput) const
5358 {
5359   // We only handle offsets for the original EXIDX input section.
5360   if (relobj != this->exidx_input_section_.relobj()
5361       || shndx != this->exidx_input_section_.shndx())
5362     return false;
5363
5364   section_offset_type section_size =
5365     convert_types<section_offset_type>(this->exidx_input_section_.size());
5366   if (offset < 0 || offset >= section_size)
5367     // Input offset is out of valid range.
5368     *poutput = -1;
5369   else
5370     {
5371       // We need to look up the section offset map to determine the output
5372       // offset.  Find the reference point in map that is first offset
5373       // bigger than or equal to this offset.
5374       Arm_exidx_section_offset_map::const_iterator p =
5375         this->section_offset_map_.lower_bound(offset);
5376
5377       // The section offset maps are build such that this should not happen if
5378       // input offset is in the valid range.
5379       gold_assert(p != this->section_offset_map_.end());
5380
5381       // We need to check if this is dropped.
5382      section_offset_type ref = p->first;
5383      section_offset_type mapped_ref = p->second;
5384
5385       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5386         // Offset is present in output.
5387         *poutput = mapped_ref + (offset - ref);
5388       else
5389         // Offset is discarded owing to EXIDX entry merging.
5390         *poutput = -1;
5391     }
5392
5393   return true;
5394 }
5395
5396 // Write this to output file OF.
5397
5398 void
5399 Arm_exidx_merged_section::do_write(Output_file* of)
5400 {
5401   off_t offset = this->offset();
5402   const section_size_type oview_size = this->data_size();
5403   unsigned char* const oview = of->get_output_view(offset, oview_size);
5404
5405   Output_section* os = this->relobj()->output_section(this->shndx());
5406   gold_assert(os != NULL);
5407
5408   memcpy(oview, this->section_contents_, oview_size);
5409   of->write_output_view(this->offset(), oview_size, oview);
5410 }
5411
5412 // Arm_exidx_fixup methods.
5413
5414 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5415 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5416 // points to the end of the last seen EXIDX section.
5417
5418 void
5419 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5420 {
5421   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5422       && this->last_input_section_ != NULL)
5423     {
5424       Relobj* relobj = this->last_input_section_->relobj();
5425       unsigned int text_shndx = this->last_input_section_->link();
5426       Arm_exidx_cantunwind* cantunwind =
5427         new Arm_exidx_cantunwind(relobj, text_shndx);
5428       this->exidx_output_section_->add_output_section_data(cantunwind);
5429       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5430     }
5431 }
5432
5433 // Process an EXIDX section entry in input.  Return whether this entry
5434 // can be deleted in the output.  SECOND_WORD in the second word of the
5435 // EXIDX entry.
5436
5437 bool
5438 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5439 {
5440   bool delete_entry;
5441   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5442     {
5443       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5444       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5445       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5446     }
5447   else if ((second_word & 0x80000000) != 0)
5448     {
5449       // Inlined unwinding data.  Merge if equal to previous.
5450       delete_entry = (merge_exidx_entries_
5451                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5452                       && this->last_inlined_entry_ == second_word);
5453       this->last_unwind_type_ = UT_INLINED_ENTRY;
5454       this->last_inlined_entry_ = second_word;
5455     }
5456   else
5457     {
5458       // Normal table entry.  In theory we could merge these too,
5459       // but duplicate entries are likely to be much less common.
5460       delete_entry = false;
5461       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5462     }
5463   return delete_entry;
5464 }
5465
5466 // Update the current section offset map during EXIDX section fix-up.
5467 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5468 // reference point, DELETED_BYTES is the number of deleted by in the
5469 // section so far.  If DELETE_ENTRY is true, the reference point and
5470 // all offsets after the previous reference point are discarded.
5471
5472 void
5473 Arm_exidx_fixup::update_offset_map(
5474     section_offset_type input_offset,
5475     section_size_type deleted_bytes,
5476     bool delete_entry)
5477 {
5478   if (this->section_offset_map_ == NULL)
5479     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5480   section_offset_type output_offset;
5481   if (delete_entry)
5482     output_offset = Arm_exidx_input_section::invalid_offset;
5483   else
5484     output_offset = input_offset - deleted_bytes;
5485   (*this->section_offset_map_)[input_offset] = output_offset;
5486 }
5487
5488 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5489 // bytes deleted.  SECTION_CONTENTS points to the contents of the EXIDX
5490 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5491 // If some entries are merged, also store a pointer to a newly created
5492 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The caller
5493 // owns the map and is responsible for releasing it after use.
5494
5495 template<bool big_endian>
5496 uint32_t
5497 Arm_exidx_fixup::process_exidx_section(
5498     const Arm_exidx_input_section* exidx_input_section,
5499     const unsigned char* section_contents,
5500     section_size_type section_size,
5501     Arm_exidx_section_offset_map** psection_offset_map)
5502 {
5503   Relobj* relobj = exidx_input_section->relobj();
5504   unsigned shndx = exidx_input_section->shndx();
5505
5506   if ((section_size % 8) != 0)
5507     {
5508       // Something is wrong with this section.  Better not touch it.
5509       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5510                  relobj->name().c_str(), shndx);
5511       this->last_input_section_ = exidx_input_section;
5512       this->last_unwind_type_ = UT_NONE;
5513       return 0;
5514     }
5515
5516   uint32_t deleted_bytes = 0;
5517   bool prev_delete_entry = false;
5518   gold_assert(this->section_offset_map_ == NULL);
5519
5520   for (section_size_type i = 0; i < section_size; i += 8)
5521     {
5522       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5523       const Valtype* wv =
5524           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5525       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5526
5527       bool delete_entry = this->process_exidx_entry(second_word);
5528
5529       // Entry deletion causes changes in output offsets.  We use a std::map
5530       // to record these.  And entry (x, y) means input offset x
5531       // is mapped to output offset y.  If y is invalid_offset, then x is
5532       // dropped in the output.  Because of the way std::map::lower_bound
5533       // works, we record the last offset in a region w.r.t to keeping or
5534       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5535       // the output offset y0 of it is determined by the output offset y1 of
5536       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5537       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Otherwise, y1
5538       // y0 is also -1.
5539       if (delete_entry != prev_delete_entry && i != 0)
5540         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5541
5542       // Update total deleted bytes for this entry.
5543       if (delete_entry)
5544         deleted_bytes += 8;
5545
5546       prev_delete_entry = delete_entry;
5547     }
5548
5549   // If section offset map is not NULL, make an entry for the end of
5550   // section.
5551   if (this->section_offset_map_ != NULL)
5552     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5553
5554   *psection_offset_map = this->section_offset_map_;
5555   this->section_offset_map_ = NULL;
5556   this->last_input_section_ = exidx_input_section;
5557
5558   // Set the first output text section so that we can link the EXIDX output
5559   // section to it.  Ignore any EXIDX input section that is completely merged.
5560   if (this->first_output_text_section_ == NULL
5561       && deleted_bytes != section_size)
5562     {
5563       unsigned int link = exidx_input_section->link();
5564       Output_section* os = relobj->output_section(link);
5565       gold_assert(os != NULL);
5566       this->first_output_text_section_ = os;
5567     }
5568
5569   return deleted_bytes;
5570 }
5571
5572 // Arm_output_section methods.
5573
5574 // Create a stub group for input sections from BEGIN to END.  OWNER
5575 // points to the input section to be the owner a new stub table.
5576
5577 template<bool big_endian>
5578 void
5579 Arm_output_section<big_endian>::create_stub_group(
5580   Input_section_list::const_iterator begin,
5581   Input_section_list::const_iterator end,
5582   Input_section_list::const_iterator owner,
5583   Target_arm<big_endian>* target,
5584   std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5585   const Task* task)
5586 {
5587   // We use a different kind of relaxed section in an EXIDX section.
5588   // The static casting from Output_relaxed_input_section to
5589   // Arm_input_section is invalid in an EXIDX section.  We are okay
5590   // because we should not be calling this for an EXIDX section.
5591   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5592
5593   // Currently we convert ordinary input sections into relaxed sections only
5594   // at this point but we may want to support creating relaxed input section
5595   // very early.  So we check here to see if owner is already a relaxed
5596   // section.
5597
5598   Arm_input_section<big_endian>* arm_input_section;
5599   if (owner->is_relaxed_input_section())
5600     {
5601       arm_input_section =
5602         Arm_input_section<big_endian>::as_arm_input_section(
5603           owner->relaxed_input_section());
5604     }
5605   else
5606     {
5607       gold_assert(owner->is_input_section());
5608       // Create a new relaxed input section.  We need to lock the original
5609       // file.
5610       Task_lock_obj<Object> tl(task, owner->relobj());
5611       arm_input_section =
5612         target->new_arm_input_section(owner->relobj(), owner->shndx());
5613       new_relaxed_sections->push_back(arm_input_section);
5614     }
5615
5616   // Create a stub table.
5617   Stub_table<big_endian>* stub_table =
5618     target->new_stub_table(arm_input_section);
5619
5620   arm_input_section->set_stub_table(stub_table);
5621
5622   Input_section_list::const_iterator p = begin;
5623   Input_section_list::const_iterator prev_p;
5624
5625   // Look for input sections or relaxed input sections in [begin ... end].
5626   do
5627     {
5628       if (p->is_input_section() || p->is_relaxed_input_section())
5629         {
5630           // The stub table information for input sections live
5631           // in their objects.
5632           Arm_relobj<big_endian>* arm_relobj =
5633             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5634           arm_relobj->set_stub_table(p->shndx(), stub_table);
5635         }
5636       prev_p = p++;
5637     }
5638   while (prev_p != end);
5639 }
5640
5641 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5642 // of stub groups.  We grow a stub group by adding input section until the
5643 // size is just below GROUP_SIZE.  The last input section will be converted
5644 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5645 // input section after the stub table, effectively double the group size.
5646 //
5647 // This is similar to the group_sections() function in elf32-arm.c but is
5648 // implemented differently.
5649
5650 template<bool big_endian>
5651 void
5652 Arm_output_section<big_endian>::group_sections(
5653     section_size_type group_size,
5654     bool stubs_always_after_branch,
5655     Target_arm<big_endian>* target,
5656     const Task* task)
5657 {
5658   // States for grouping.
5659   typedef enum
5660   {
5661     // No group is being built.
5662     NO_GROUP,
5663     // A group is being built but the stub table is not found yet.
5664     // We keep group a stub group until the size is just under GROUP_SIZE.
5665     // The last input section in the group will be used as the stub table.
5666     FINDING_STUB_SECTION,
5667     // A group is being built and we have already found a stub table.
5668     // We enter this state to grow a stub group by adding input section
5669     // after the stub table.  This effectively doubles the group size.
5670     HAS_STUB_SECTION
5671   } State;
5672
5673   // Any newly created relaxed sections are stored here.
5674   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5675
5676   State state = NO_GROUP;
5677   section_size_type off = 0;
5678   section_size_type group_begin_offset = 0;
5679   section_size_type group_end_offset = 0;
5680   section_size_type stub_table_end_offset = 0;
5681   Input_section_list::const_iterator group_begin =
5682     this->input_sections().end();
5683   Input_section_list::const_iterator stub_table =
5684     this->input_sections().end();
5685   Input_section_list::const_iterator group_end = this->input_sections().end();
5686   for (Input_section_list::const_iterator p = this->input_sections().begin();
5687        p != this->input_sections().end();
5688        ++p)
5689     {
5690       section_size_type section_begin_offset =
5691         align_address(off, p->addralign());
5692       section_size_type section_end_offset =
5693         section_begin_offset + p->data_size();
5694
5695       // Check to see if we should group the previously seen sections.
5696       switch (state)
5697         {
5698         case NO_GROUP:
5699           break;
5700
5701         case FINDING_STUB_SECTION:
5702           // Adding this section makes the group larger than GROUP_SIZE.
5703           if (section_end_offset - group_begin_offset >= group_size)
5704             {
5705               if (stubs_always_after_branch)
5706                 {
5707                   gold_assert(group_end != this->input_sections().end());
5708                   this->create_stub_group(group_begin, group_end, group_end,
5709                                           target, &new_relaxed_sections,
5710                                           task);
5711                   state = NO_GROUP;
5712                 }
5713               else
5714                 {
5715                   // But wait, there's more!  Input sections up to
5716                   // stub_group_size bytes after the stub table can be
5717                   // handled by it too.
5718                   state = HAS_STUB_SECTION;
5719                   stub_table = group_end;
5720                   stub_table_end_offset = group_end_offset;
5721                 }
5722             }
5723             break;
5724
5725         case HAS_STUB_SECTION:
5726           // Adding this section makes the post stub-section group larger
5727           // than GROUP_SIZE.
5728           if (section_end_offset - stub_table_end_offset >= group_size)
5729            {
5730              gold_assert(group_end != this->input_sections().end());
5731              this->create_stub_group(group_begin, group_end, stub_table,
5732                                      target, &new_relaxed_sections, task);
5733              state = NO_GROUP;
5734            }
5735            break;
5736
5737           default:
5738             gold_unreachable();
5739         }
5740
5741       // If we see an input section and currently there is no group, start
5742       // a new one.  Skip any empty sections.  We look at the data size
5743       // instead of calling p->relobj()->section_size() to avoid locking.
5744       if ((p->is_input_section() || p->is_relaxed_input_section())
5745           && (p->data_size() != 0))
5746         {
5747           if (state == NO_GROUP)
5748             {
5749               state = FINDING_STUB_SECTION;
5750               group_begin = p;
5751               group_begin_offset = section_begin_offset;
5752             }
5753
5754           // Keep track of the last input section seen.
5755           group_end = p;
5756           group_end_offset = section_end_offset;
5757         }
5758
5759       off = section_end_offset;
5760     }
5761
5762   // Create a stub group for any ungrouped sections.
5763   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5764     {
5765       gold_assert(group_end != this->input_sections().end());
5766       this->create_stub_group(group_begin, group_end,
5767                               (state == FINDING_STUB_SECTION
5768                                ? group_end
5769                                : stub_table),
5770                                target, &new_relaxed_sections, task);
5771     }
5772
5773   // Convert input section into relaxed input section in a batch.
5774   if (!new_relaxed_sections.empty())
5775     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5776
5777   // Update the section offsets
5778   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5779     {
5780       Arm_relobj<big_endian>* arm_relobj =
5781         Arm_relobj<big_endian>::as_arm_relobj(
5782           new_relaxed_sections[i]->relobj());
5783       unsigned int shndx = new_relaxed_sections[i]->shndx();
5784       // Tell Arm_relobj that this input section is converted.
5785       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5786     }
5787 }
5788
5789 // Append non empty text sections in this to LIST in ascending
5790 // order of their position in this.
5791
5792 template<bool big_endian>
5793 void
5794 Arm_output_section<big_endian>::append_text_sections_to_list(
5795     Text_section_list* list)
5796 {
5797   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5798
5799   for (Input_section_list::const_iterator p = this->input_sections().begin();
5800        p != this->input_sections().end();
5801        ++p)
5802     {
5803       // We only care about plain or relaxed input sections.  We also
5804       // ignore any merged sections.
5805       if (p->is_input_section() || p->is_relaxed_input_section())
5806         list->push_back(Text_section_list::value_type(p->relobj(),
5807                                                       p->shndx()));
5808     }
5809 }
5810
5811 template<bool big_endian>
5812 void
5813 Arm_output_section<big_endian>::fix_exidx_coverage(
5814     Layout* layout,
5815     const Text_section_list& sorted_text_sections,
5816     Symbol_table* symtab,
5817     bool merge_exidx_entries,
5818     const Task* task)
5819 {
5820   // We should only do this for the EXIDX output section.
5821   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5822
5823   // We don't want the relaxation loop to undo these changes, so we discard
5824   // the current saved states and take another one after the fix-up.
5825   this->discard_states();
5826
5827   // Remove all input sections.
5828   uint64_t address = this->address();
5829   typedef std::list<Output_section::Input_section> Input_section_list;
5830   Input_section_list input_sections;
5831   this->reset_address_and_file_offset();
5832   this->get_input_sections(address, std::string(""), &input_sections);
5833
5834   if (!this->input_sections().empty())
5835     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5836
5837   // Go through all the known input sections and record them.
5838   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5839   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5840                         Section_id_hash> Text_to_exidx_map;
5841   Text_to_exidx_map text_to_exidx_map;
5842   for (Input_section_list::const_iterator p = input_sections.begin();
5843        p != input_sections.end();
5844        ++p)
5845     {
5846       // This should never happen.  At this point, we should only see
5847       // plain EXIDX input sections.
5848       gold_assert(!p->is_relaxed_input_section());
5849       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5850     }
5851
5852   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5853
5854   // Go over the sorted text sections.
5855   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5856   Section_id_set processed_input_sections;
5857   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5858        p != sorted_text_sections.end();
5859        ++p)
5860     {
5861       Relobj* relobj = p->first;
5862       unsigned int shndx = p->second;
5863
5864       Arm_relobj<big_endian>* arm_relobj =
5865          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5866       const Arm_exidx_input_section* exidx_input_section =
5867          arm_relobj->exidx_input_section_by_link(shndx);
5868
5869       // If this text section has no EXIDX section or if the EXIDX section
5870       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5871       // of the last seen EXIDX section.
5872       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5873         {
5874           exidx_fixup.add_exidx_cantunwind_as_needed();
5875           continue;
5876         }
5877
5878       Relobj* exidx_relobj = exidx_input_section->relobj();
5879       unsigned int exidx_shndx = exidx_input_section->shndx();
5880       Section_id sid(exidx_relobj, exidx_shndx);
5881       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5882       if (iter == text_to_exidx_map.end())
5883         {
5884           // This is odd.  We have not seen this EXIDX input section before.
5885           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5886           // issue a warning instead.  We assume the user knows what he
5887           // or she is doing.  Otherwise, this is an error.
5888           if (layout->script_options()->saw_sections_clause())
5889             gold_warning(_("unwinding may not work because EXIDX input section"
5890                            " %u of %s is not in EXIDX output section"),
5891                          exidx_shndx, exidx_relobj->name().c_str());
5892           else
5893             gold_error(_("unwinding may not work because EXIDX input section"
5894                          " %u of %s is not in EXIDX output section"),
5895                        exidx_shndx, exidx_relobj->name().c_str());
5896
5897           exidx_fixup.add_exidx_cantunwind_as_needed();
5898           continue;
5899         }
5900
5901       // We need to access the contents of the EXIDX section, lock the
5902       // object here.
5903       Task_lock_obj<Object> tl(task, exidx_relobj);
5904       section_size_type exidx_size;
5905       const unsigned char* exidx_contents =
5906         exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5907
5908       // Fix up coverage and append input section to output data list.
5909       Arm_exidx_section_offset_map* section_offset_map = NULL;
5910       uint32_t deleted_bytes =
5911         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5912                                                       exidx_contents,
5913                                                       exidx_size,
5914                                                       &section_offset_map);
5915
5916       if (deleted_bytes == exidx_input_section->size())
5917         {
5918           // The whole EXIDX section got merged.  Remove it from output.
5919           gold_assert(section_offset_map == NULL);
5920           exidx_relobj->set_output_section(exidx_shndx, NULL);
5921
5922           // All local symbols defined in this input section will be dropped.
5923           // We need to adjust output local symbol count.
5924           arm_relobj->set_output_local_symbol_count_needs_update();
5925         }
5926       else if (deleted_bytes > 0)
5927         {
5928           // Some entries are merged.  We need to convert this EXIDX input
5929           // section into a relaxed section.
5930           gold_assert(section_offset_map != NULL);
5931
5932           Arm_exidx_merged_section* merged_section =
5933             new Arm_exidx_merged_section(*exidx_input_section,
5934                                          *section_offset_map, deleted_bytes);
5935           merged_section->build_contents(exidx_contents, exidx_size);
5936
5937           const std::string secname = exidx_relobj->section_name(exidx_shndx);
5938           this->add_relaxed_input_section(layout, merged_section, secname);
5939           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5940
5941           // All local symbols defined in discarded portions of this input
5942           // section will be dropped.  We need to adjust output local symbol
5943           // count.
5944           arm_relobj->set_output_local_symbol_count_needs_update();
5945         }
5946       else
5947         {
5948           // Just add back the EXIDX input section.
5949           gold_assert(section_offset_map == NULL);
5950           const Output_section::Input_section* pis = iter->second;
5951           gold_assert(pis->is_input_section());
5952           this->add_script_input_section(*pis);
5953         }
5954
5955       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5956     }
5957
5958   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5959   exidx_fixup.add_exidx_cantunwind_as_needed();
5960
5961   // Remove any known EXIDX input sections that are not processed.
5962   for (Input_section_list::const_iterator p = input_sections.begin();
5963        p != input_sections.end();
5964        ++p)
5965     {
5966       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5967           == processed_input_sections.end())
5968         {
5969           // We discard a known EXIDX section because its linked
5970           // text section has been folded by ICF.  We also discard an
5971           // EXIDX section with error, the output does not matter in this
5972           // case.  We do this to avoid triggering asserts.
5973           Arm_relobj<big_endian>* arm_relobj =
5974             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5975           const Arm_exidx_input_section* exidx_input_section =
5976             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5977           gold_assert(exidx_input_section != NULL);
5978           if (!exidx_input_section->has_errors())
5979             {
5980               unsigned int text_shndx = exidx_input_section->link();
5981               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5982             }
5983
5984           // Remove this from link.  We also need to recount the
5985           // local symbols.
5986           p->relobj()->set_output_section(p->shndx(), NULL);
5987           arm_relobj->set_output_local_symbol_count_needs_update();
5988         }
5989     }
5990
5991   // Link exidx output section to the first seen output section and
5992   // set correct entry size.
5993   this->set_link_section(exidx_fixup.first_output_text_section());
5994   this->set_entsize(8);
5995
5996   // Make changes permanent.
5997   this->save_states();
5998   this->set_section_offsets_need_adjustment();
5999 }
6000
6001 // Link EXIDX output sections to text output sections.
6002
6003 template<bool big_endian>
6004 void
6005 Arm_output_section<big_endian>::set_exidx_section_link()
6006 {
6007   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6008   if (!this->input_sections().empty())
6009     {
6010       Input_section_list::const_iterator p = this->input_sections().begin();
6011       Arm_relobj<big_endian>* arm_relobj =
6012         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6013       unsigned exidx_shndx = p->shndx();
6014       const Arm_exidx_input_section* exidx_input_section =
6015         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6016       gold_assert(exidx_input_section != NULL);
6017       unsigned int text_shndx = exidx_input_section->link();
6018       Output_section* os = arm_relobj->output_section(text_shndx);
6019       this->set_link_section(os);
6020     }
6021 }
6022
6023 // Arm_relobj methods.
6024
6025 // Determine if an input section is scannable for stub processing.  SHDR is
6026 // the header of the section and SHNDX is the section index.  OS is the output
6027 // section for the input section and SYMTAB is the global symbol table used to
6028 // look up ICF information.
6029
6030 template<bool big_endian>
6031 bool
6032 Arm_relobj<big_endian>::section_is_scannable(
6033     const elfcpp::Shdr<32, big_endian>& shdr,
6034     unsigned int shndx,
6035     const Output_section* os,
6036     const Symbol_table* symtab)
6037 {
6038   // Skip any empty sections, unallocated sections or sections whose
6039   // type are not SHT_PROGBITS.
6040   if (shdr.get_sh_size() == 0
6041       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6042       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6043     return false;
6044
6045   // Skip any discarded or ICF'ed sections.
6046   if (os == NULL || symtab->is_section_folded(this, shndx))
6047     return false;
6048
6049   // If this requires special offset handling, check to see if it is
6050   // a relaxed section.  If this is not, then it is a merged section that
6051   // we cannot handle.
6052   if (this->is_output_section_offset_invalid(shndx))
6053     {
6054       const Output_relaxed_input_section* poris =
6055         os->find_relaxed_input_section(this, shndx);
6056       if (poris == NULL)
6057         return false;
6058     }
6059
6060   return true;
6061 }
6062
6063 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6064 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6065
6066 template<bool big_endian>
6067 bool
6068 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6069     const elfcpp::Shdr<32, big_endian>& shdr,
6070     const Relobj::Output_sections& out_sections,
6071     const Symbol_table* symtab,
6072     const unsigned char* pshdrs)
6073 {
6074   unsigned int sh_type = shdr.get_sh_type();
6075   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6076     return false;
6077
6078   // Ignore empty section.
6079   off_t sh_size = shdr.get_sh_size();
6080   if (sh_size == 0)
6081     return false;
6082
6083   // Ignore reloc section with unexpected symbol table.  The
6084   // error will be reported in the final link.
6085   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6086     return false;
6087
6088   unsigned int reloc_size;
6089   if (sh_type == elfcpp::SHT_REL)
6090     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6091   else
6092     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6093
6094   // Ignore reloc section with unexpected entsize or uneven size.
6095   // The error will be reported in the final link.
6096   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6097     return false;
6098
6099   // Ignore reloc section with bad info.  This error will be
6100   // reported in the final link.
6101   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6102   if (index >= this->shnum())
6103     return false;
6104
6105   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6106   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6107   return this->section_is_scannable(text_shdr, index,
6108                                    out_sections[index], symtab);
6109 }
6110
6111 // Return the output address of either a plain input section or a relaxed
6112 // input section.  SHNDX is the section index.  We define and use this
6113 // instead of calling Output_section::output_address because that is slow
6114 // for large output.
6115
6116 template<bool big_endian>
6117 Arm_address
6118 Arm_relobj<big_endian>::simple_input_section_output_address(
6119     unsigned int shndx,
6120     Output_section* os)
6121 {
6122   if (this->is_output_section_offset_invalid(shndx))
6123     {
6124       const Output_relaxed_input_section* poris =
6125         os->find_relaxed_input_section(this, shndx);
6126       // We do not handle merged sections here.
6127       gold_assert(poris != NULL);
6128       return poris->address();
6129     }
6130   else
6131     return os->address() + this->get_output_section_offset(shndx);
6132 }
6133
6134 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6135 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6136
6137 template<bool big_endian>
6138 bool
6139 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6140     const elfcpp::Shdr<32, big_endian>& shdr,
6141     unsigned int shndx,
6142     Output_section* os,
6143     const Symbol_table* symtab)
6144 {
6145   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6146     return false;
6147
6148   // If the section does not cross any 4K-boundaries, it does not need to
6149   // be scanned.
6150   Arm_address address = this->simple_input_section_output_address(shndx, os);
6151   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6152     return false;
6153
6154   return true;
6155 }
6156
6157 // Scan a section for Cortex-A8 workaround.
6158
6159 template<bool big_endian>
6160 void
6161 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6162     const elfcpp::Shdr<32, big_endian>& shdr,
6163     unsigned int shndx,
6164     Output_section* os,
6165     Target_arm<big_endian>* arm_target)
6166 {
6167   // Look for the first mapping symbol in this section.  It should be
6168   // at (shndx, 0).
6169   Mapping_symbol_position section_start(shndx, 0);
6170   typename Mapping_symbols_info::const_iterator p =
6171     this->mapping_symbols_info_.lower_bound(section_start);
6172
6173   // There are no mapping symbols for this section.  Treat it as a data-only
6174   // section.  Issue a warning if section is marked as containing
6175   // instructions.
6176   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6177     {
6178       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6179         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6180                        "erratum because it has no mapping symbols."),
6181                      shndx, this->name().c_str());
6182       return;
6183     }
6184
6185   Arm_address output_address =
6186     this->simple_input_section_output_address(shndx, os);
6187
6188   // Get the section contents.
6189   section_size_type input_view_size = 0;
6190   const unsigned char* input_view =
6191     this->section_contents(shndx, &input_view_size, false);
6192
6193   // We need to go through the mapping symbols to determine what to
6194   // scan.  There are two reasons.  First, we should look at THUMB code and
6195   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6196   // to speed up the scanning.
6197
6198   while (p != this->mapping_symbols_info_.end()
6199         && p->first.first == shndx)
6200     {
6201       typename Mapping_symbols_info::const_iterator next =
6202         this->mapping_symbols_info_.upper_bound(p->first);
6203
6204       // Only scan part of a section with THUMB code.
6205       if (p->second == 't')
6206         {
6207           // Determine the end of this range.
6208           section_size_type span_start =
6209             convert_to_section_size_type(p->first.second);
6210           section_size_type span_end;
6211           if (next != this->mapping_symbols_info_.end()
6212               && next->first.first == shndx)
6213             span_end = convert_to_section_size_type(next->first.second);
6214           else
6215             span_end = convert_to_section_size_type(shdr.get_sh_size());
6216
6217           if (((span_start + output_address) & ~0xfffUL)
6218               != ((span_end + output_address - 1) & ~0xfffUL))
6219             {
6220               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6221                                                           span_start, span_end,
6222                                                           input_view,
6223                                                           output_address);
6224             }
6225         }
6226
6227       p = next;
6228     }
6229 }
6230
6231 // Scan relocations for stub generation.
6232
6233 template<bool big_endian>
6234 void
6235 Arm_relobj<big_endian>::scan_sections_for_stubs(
6236     Target_arm<big_endian>* arm_target,
6237     const Symbol_table* symtab,
6238     const Layout* layout)
6239 {
6240   unsigned int shnum = this->shnum();
6241   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6242
6243   // Read the section headers.
6244   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6245                                                shnum * shdr_size,
6246                                                true, true);
6247
6248   // To speed up processing, we set up hash tables for fast lookup of
6249   // input offsets to output addresses.
6250   this->initialize_input_to_output_maps();
6251
6252   const Relobj::Output_sections& out_sections(this->output_sections());
6253
6254   Relocate_info<32, big_endian> relinfo;
6255   relinfo.symtab = symtab;
6256   relinfo.layout = layout;
6257   relinfo.object = this;
6258
6259   // Do relocation stubs scanning.
6260   const unsigned char* p = pshdrs + shdr_size;
6261   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6262     {
6263       const elfcpp::Shdr<32, big_endian> shdr(p);
6264       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6265                                                   pshdrs))
6266         {
6267           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6268           Arm_address output_offset = this->get_output_section_offset(index);
6269           Arm_address output_address;
6270           if (output_offset != invalid_address)
6271             output_address = out_sections[index]->address() + output_offset;
6272           else
6273             {
6274               // Currently this only happens for a relaxed section.
6275               const Output_relaxed_input_section* poris =
6276               out_sections[index]->find_relaxed_input_section(this, index);
6277               gold_assert(poris != NULL);
6278               output_address = poris->address();
6279             }
6280
6281           // Get the relocations.
6282           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6283                                                         shdr.get_sh_size(),
6284                                                         true, false);
6285
6286           // Get the section contents.  This does work for the case in which
6287           // we modify the contents of an input section.  We need to pass the
6288           // output view under such circumstances.
6289           section_size_type input_view_size = 0;
6290           const unsigned char* input_view =
6291             this->section_contents(index, &input_view_size, false);
6292
6293           relinfo.reloc_shndx = i;
6294           relinfo.data_shndx = index;
6295           unsigned int sh_type = shdr.get_sh_type();
6296           unsigned int reloc_size;
6297           if (sh_type == elfcpp::SHT_REL)
6298             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6299           else
6300             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6301
6302           Output_section* os = out_sections[index];
6303           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6304                                              shdr.get_sh_size() / reloc_size,
6305                                              os,
6306                                              output_offset == invalid_address,
6307                                              input_view, output_address,
6308                                              input_view_size);
6309         }
6310     }
6311
6312   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6313   // after its relocation section, if there is one, is processed for
6314   // relocation stubs.  Merging this loop with the one above would have been
6315   // complicated since we would have had to make sure that relocation stub
6316   // scanning is done first.
6317   if (arm_target->fix_cortex_a8())
6318     {
6319       const unsigned char* p = pshdrs + shdr_size;
6320       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6321         {
6322           const elfcpp::Shdr<32, big_endian> shdr(p);
6323           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6324                                                           out_sections[i],
6325                                                           symtab))
6326             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6327                                                      arm_target);
6328         }
6329     }
6330
6331   // After we've done the relocations, we release the hash tables,
6332   // since we no longer need them.
6333   this->free_input_to_output_maps();
6334 }
6335
6336 // Count the local symbols.  The ARM backend needs to know if a symbol
6337 // is a THUMB function or not.  For global symbols, it is easy because
6338 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6339 // harder because we cannot access this information.   So we override the
6340 // do_count_local_symbol in parent and scan local symbols to mark
6341 // THUMB functions.  This is not the most efficient way but I do not want to
6342 // slow down other ports by calling a per symbol target hook inside
6343 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6344
6345 template<bool big_endian>
6346 void
6347 Arm_relobj<big_endian>::do_count_local_symbols(
6348     Stringpool_template<char>* pool,
6349     Stringpool_template<char>* dynpool)
6350 {
6351   // We need to fix-up the values of any local symbols whose type are
6352   // STT_ARM_TFUNC.
6353
6354   // Ask parent to count the local symbols.
6355   Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6356   const unsigned int loccount = this->local_symbol_count();
6357   if (loccount == 0)
6358     return;
6359
6360   // Initialize the thumb function bit-vector.
6361   std::vector<bool> empty_vector(loccount, false);
6362   this->local_symbol_is_thumb_function_.swap(empty_vector);
6363
6364   // Read the symbol table section header.
6365   const unsigned int symtab_shndx = this->symtab_shndx();
6366   elfcpp::Shdr<32, big_endian>
6367       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6368   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6369
6370   // Read the local symbols.
6371   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6372   gold_assert(loccount == symtabshdr.get_sh_info());
6373   off_t locsize = loccount * sym_size;
6374   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6375                                               locsize, true, true);
6376
6377   // For mapping symbol processing, we need to read the symbol names.
6378   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6379   if (strtab_shndx >= this->shnum())
6380     {
6381       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6382       return;
6383     }
6384
6385   elfcpp::Shdr<32, big_endian>
6386     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6387   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6388     {
6389       this->error(_("symbol table name section has wrong type: %u"),
6390                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6391       return;
6392     }
6393   const char* pnames =
6394     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6395                                                  strtabshdr.get_sh_size(),
6396                                                  false, false));
6397
6398   // Loop over the local symbols and mark any local symbols pointing
6399   // to THUMB functions.
6400
6401   // Skip the first dummy symbol.
6402   psyms += sym_size;
6403   typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6404     this->local_values();
6405   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6406     {
6407       elfcpp::Sym<32, big_endian> sym(psyms);
6408       elfcpp::STT st_type = sym.get_st_type();
6409       Symbol_value<32>& lv((*plocal_values)[i]);
6410       Arm_address input_value = lv.input_value();
6411
6412       // Check to see if this is a mapping symbol.
6413       const char* sym_name = pnames + sym.get_st_name();
6414       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6415         {
6416           bool is_ordinary;
6417           unsigned int input_shndx =
6418             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6419           gold_assert(is_ordinary);
6420
6421           // Strip of LSB in case this is a THUMB symbol.
6422           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6423           this->mapping_symbols_info_[msp] = sym_name[1];
6424         }
6425
6426       if (st_type == elfcpp::STT_ARM_TFUNC
6427           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6428         {
6429           // This is a THUMB function.  Mark this and canonicalize the
6430           // symbol value by setting LSB.
6431           this->local_symbol_is_thumb_function_[i] = true;
6432           if ((input_value & 1) == 0)
6433             lv.set_input_value(input_value | 1);
6434         }
6435     }
6436 }
6437
6438 // Relocate sections.
6439 template<bool big_endian>
6440 void
6441 Arm_relobj<big_endian>::do_relocate_sections(
6442     const Symbol_table* symtab,
6443     const Layout* layout,
6444     const unsigned char* pshdrs,
6445     Output_file* of,
6446     typename Sized_relobj_file<32, big_endian>::Views* pviews)
6447 {
6448   // Call parent to relocate sections.
6449   Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6450                                                           pshdrs, of, pviews);
6451
6452   // We do not generate stubs if doing a relocatable link.
6453   if (parameters->options().relocatable())
6454     return;
6455
6456   // Relocate stub tables.
6457   unsigned int shnum = this->shnum();
6458
6459   Target_arm<big_endian>* arm_target =
6460     Target_arm<big_endian>::default_target();
6461
6462   Relocate_info<32, big_endian> relinfo;
6463   relinfo.symtab = symtab;
6464   relinfo.layout = layout;
6465   relinfo.object = this;
6466
6467   for (unsigned int i = 1; i < shnum; ++i)
6468     {
6469       Arm_input_section<big_endian>* arm_input_section =
6470         arm_target->find_arm_input_section(this, i);
6471
6472       if (arm_input_section != NULL
6473           && arm_input_section->is_stub_table_owner()
6474           && !arm_input_section->stub_table()->empty())
6475         {
6476           // We cannot discard a section if it owns a stub table.
6477           Output_section* os = this->output_section(i);
6478           gold_assert(os != NULL);
6479
6480           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6481           relinfo.reloc_shdr = NULL;
6482           relinfo.data_shndx = i;
6483           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6484
6485           gold_assert((*pviews)[i].view != NULL);
6486
6487           // We are passed the output section view.  Adjust it to cover the
6488           // stub table only.
6489           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6490           gold_assert((stub_table->address() >= (*pviews)[i].address)
6491                       && ((stub_table->address() + stub_table->data_size())
6492                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6493
6494           off_t offset = stub_table->address() - (*pviews)[i].address;
6495           unsigned char* view = (*pviews)[i].view + offset;
6496           Arm_address address = stub_table->address();
6497           section_size_type view_size = stub_table->data_size();
6498
6499           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6500                                      view_size);
6501         }
6502
6503       // Apply Cortex A8 workaround if applicable.
6504       if (this->section_has_cortex_a8_workaround(i))
6505         {
6506           unsigned char* view = (*pviews)[i].view;
6507           Arm_address view_address = (*pviews)[i].address;
6508           section_size_type view_size = (*pviews)[i].view_size;
6509           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6510
6511           // Adjust view to cover section.
6512           Output_section* os = this->output_section(i);
6513           gold_assert(os != NULL);
6514           Arm_address section_address =
6515             this->simple_input_section_output_address(i, os);
6516           uint64_t section_size = this->section_size(i);
6517
6518           gold_assert(section_address >= view_address
6519                       && ((section_address + section_size)
6520                           <= (view_address + view_size)));
6521
6522           unsigned char* section_view = view + (section_address - view_address);
6523
6524           // Apply the Cortex-A8 workaround to the output address range
6525           // corresponding to this input section.
6526           stub_table->apply_cortex_a8_workaround_to_address_range(
6527               arm_target,
6528               section_view,
6529               section_address,
6530               section_size);
6531         }
6532     }
6533 }
6534
6535 // Find the linked text section of an EXIDX section by looking at the first
6536 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6537 // must be linked to its associated code section via the sh_link field of
6538 // its section header.  However, some tools are broken and the link is not
6539 // always set.  LD just drops such an EXIDX section silently, causing the
6540 // associated code not unwindabled.   Here we try a little bit harder to
6541 // discover the linked code section.
6542 //
6543 // PSHDR points to the section header of a relocation section of an EXIDX
6544 // section.  If we can find a linked text section, return true and
6545 // store the text section index in the location PSHNDX.  Otherwise
6546 // return false.
6547
6548 template<bool big_endian>
6549 bool
6550 Arm_relobj<big_endian>::find_linked_text_section(
6551     const unsigned char* pshdr,
6552     const unsigned char* psyms,
6553     unsigned int* pshndx)
6554 {
6555   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6556
6557   // If there is no relocation, we cannot find the linked text section.
6558   size_t reloc_size;
6559   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6560       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6561   else
6562       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6563   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6564
6565   // Get the relocations.
6566   const unsigned char* prelocs =
6567       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6568
6569   // Find the REL31 relocation for the first word of the first EXIDX entry.
6570   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6571     {
6572       Arm_address r_offset;
6573       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6574       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6575         {
6576           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6577           r_info = reloc.get_r_info();
6578           r_offset = reloc.get_r_offset();
6579         }
6580       else
6581         {
6582           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6583           r_info = reloc.get_r_info();
6584           r_offset = reloc.get_r_offset();
6585         }
6586
6587       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6588       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6589         continue;
6590
6591       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6592       if (r_sym == 0
6593           || r_sym >= this->local_symbol_count()
6594           || r_offset != 0)
6595         continue;
6596
6597       // This is the relocation for the first word of the first EXIDX entry.
6598       // We expect to see a local section symbol.
6599       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6600       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6601       if (sym.get_st_type() == elfcpp::STT_SECTION)
6602         {
6603           bool is_ordinary;
6604           *pshndx =
6605             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6606           gold_assert(is_ordinary);
6607           return true;
6608         }
6609       else
6610         return false;
6611     }
6612
6613   return false;
6614 }
6615
6616 // Make an EXIDX input section object for an EXIDX section whose index is
6617 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6618 // is the section index of the linked text section.
6619
6620 template<bool big_endian>
6621 void
6622 Arm_relobj<big_endian>::make_exidx_input_section(
6623     unsigned int shndx,
6624     const elfcpp::Shdr<32, big_endian>& shdr,
6625     unsigned int text_shndx,
6626     const elfcpp::Shdr<32, big_endian>& text_shdr)
6627 {
6628   // Create an Arm_exidx_input_section object for this EXIDX section.
6629   Arm_exidx_input_section* exidx_input_section =
6630     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6631                                 shdr.get_sh_addralign(),
6632                                 text_shdr.get_sh_size());
6633
6634   gold_assert(this->exidx_section_map_[shndx] == NULL);
6635   this->exidx_section_map_[shndx] = exidx_input_section;
6636
6637   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6638     {
6639       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6640                  this->section_name(shndx).c_str(), shndx, text_shndx,
6641                  this->name().c_str());
6642       exidx_input_section->set_has_errors();
6643     }
6644   else if (this->exidx_section_map_[text_shndx] != NULL)
6645     {
6646       unsigned other_exidx_shndx =
6647         this->exidx_section_map_[text_shndx]->shndx();
6648       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6649                    "%s(%u) in %s"),
6650                  this->section_name(shndx).c_str(), shndx,
6651                  this->section_name(other_exidx_shndx).c_str(),
6652                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6653                  text_shndx, this->name().c_str());
6654       exidx_input_section->set_has_errors();
6655     }
6656   else
6657      this->exidx_section_map_[text_shndx] = exidx_input_section;
6658
6659   // Check section flags of text section.
6660   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6661     {
6662       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6663                    " in %s"),
6664                  this->section_name(shndx).c_str(), shndx,
6665                  this->section_name(text_shndx).c_str(), text_shndx,
6666                  this->name().c_str());
6667       exidx_input_section->set_has_errors();
6668     }
6669   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6670     // I would like to make this an error but currently ld just ignores
6671     // this.
6672     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6673                    "%s(%u) in %s"),
6674                  this->section_name(shndx).c_str(), shndx,
6675                  this->section_name(text_shndx).c_str(), text_shndx,
6676                  this->name().c_str());
6677 }
6678
6679 // Read the symbol information.
6680
6681 template<bool big_endian>
6682 void
6683 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6684 {
6685   // Call parent class to read symbol information.
6686   Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6687
6688   // If this input file is a binary file, it has no processor
6689   // specific flags and attributes section.
6690   Input_file::Format format = this->input_file()->format();
6691   if (format != Input_file::FORMAT_ELF)
6692     {
6693       gold_assert(format == Input_file::FORMAT_BINARY);
6694       this->merge_flags_and_attributes_ = false;
6695       return;
6696     }
6697
6698   // Read processor-specific flags in ELF file header.
6699   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6700                                               elfcpp::Elf_sizes<32>::ehdr_size,
6701                                               true, false);
6702   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6703   this->processor_specific_flags_ = ehdr.get_e_flags();
6704
6705   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6706   // sections.
6707   std::vector<unsigned int> deferred_exidx_sections;
6708   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6709   const unsigned char* pshdrs = sd->section_headers->data();
6710   const unsigned char* ps = pshdrs + shdr_size;
6711   bool must_merge_flags_and_attributes = false;
6712   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6713     {
6714       elfcpp::Shdr<32, big_endian> shdr(ps);
6715
6716       // Sometimes an object has no contents except the section name string
6717       // table and an empty symbol table with the undefined symbol.  We
6718       // don't want to merge processor-specific flags from such an object.
6719       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6720         {
6721           // Symbol table is not empty.
6722           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6723              elfcpp::Elf_sizes<32>::sym_size;
6724           if (shdr.get_sh_size() > sym_size)
6725             must_merge_flags_and_attributes = true;
6726         }
6727       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6728         // If this is neither an empty symbol table nor a string table,
6729         // be conservative.
6730         must_merge_flags_and_attributes = true;
6731
6732       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6733         {
6734           gold_assert(this->attributes_section_data_ == NULL);
6735           section_offset_type section_offset = shdr.get_sh_offset();
6736           section_size_type section_size =
6737             convert_to_section_size_type(shdr.get_sh_size());
6738           const unsigned char* view =
6739              this->get_view(section_offset, section_size, true, false);
6740           this->attributes_section_data_ =
6741             new Attributes_section_data(view, section_size);
6742         }
6743       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6744         {
6745           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6746           if (text_shndx == elfcpp::SHN_UNDEF)
6747             deferred_exidx_sections.push_back(i);
6748           else
6749             {
6750               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6751                                                      + text_shndx * shdr_size);
6752               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6753             }
6754           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6755           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6756             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6757                          this->section_name(i).c_str(), this->name().c_str());
6758         }
6759     }
6760
6761   // This is rare.
6762   if (!must_merge_flags_and_attributes)
6763     {
6764       gold_assert(deferred_exidx_sections.empty());
6765       this->merge_flags_and_attributes_ = false;
6766       return;
6767     }
6768
6769   // Some tools are broken and they do not set the link of EXIDX sections.
6770   // We look at the first relocation to figure out the linked sections.
6771   if (!deferred_exidx_sections.empty())
6772     {
6773       // We need to go over the section headers again to find the mapping
6774       // from sections being relocated to their relocation sections.  This is
6775       // a bit inefficient as we could do that in the loop above.  However,
6776       // we do not expect any deferred EXIDX sections normally.  So we do not
6777       // want to slow down the most common path.
6778       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6779       Reloc_map reloc_map;
6780       ps = pshdrs + shdr_size;
6781       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6782         {
6783           elfcpp::Shdr<32, big_endian> shdr(ps);
6784           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6785           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6786             {
6787               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6788               if (info_shndx >= this->shnum())
6789                 gold_error(_("relocation section %u has invalid info %u"),
6790                            i, info_shndx);
6791               Reloc_map::value_type value(info_shndx, i);
6792               std::pair<Reloc_map::iterator, bool> result =
6793                 reloc_map.insert(value);
6794               if (!result.second)
6795                 gold_error(_("section %u has multiple relocation sections "
6796                              "%u and %u"),
6797                            info_shndx, i, reloc_map[info_shndx]);
6798             }
6799         }
6800
6801       // Read the symbol table section header.
6802       const unsigned int symtab_shndx = this->symtab_shndx();
6803       elfcpp::Shdr<32, big_endian>
6804           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6805       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6806
6807       // Read the local symbols.
6808       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6809       const unsigned int loccount = this->local_symbol_count();
6810       gold_assert(loccount == symtabshdr.get_sh_info());
6811       off_t locsize = loccount * sym_size;
6812       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6813                                                   locsize, true, true);
6814
6815       // Process the deferred EXIDX sections.
6816       for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6817         {
6818           unsigned int shndx = deferred_exidx_sections[i];
6819           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6820           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6821           Reloc_map::const_iterator it = reloc_map.find(shndx);
6822           if (it != reloc_map.end())
6823             find_linked_text_section(pshdrs + it->second * shdr_size,
6824                                      psyms, &text_shndx);
6825           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6826                                                  + text_shndx * shdr_size);
6827           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6828         }
6829     }
6830 }
6831
6832 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6833 // sections for unwinding.  These sections are referenced implicitly by
6834 // text sections linked in the section headers.  If we ignore these implicit
6835 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6836 // will be garbage-collected incorrectly.  Hence we override the same function
6837 // in the base class to handle these implicit references.
6838
6839 template<bool big_endian>
6840 void
6841 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6842                                              Layout* layout,
6843                                              Read_relocs_data* rd)
6844 {
6845   // First, call base class method to process relocations in this object.
6846   Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6847
6848   // If --gc-sections is not specified, there is nothing more to do.
6849   // This happens when --icf is used but --gc-sections is not.
6850   if (!parameters->options().gc_sections())
6851     return;
6852
6853   unsigned int shnum = this->shnum();
6854   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6855   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6856                                                shnum * shdr_size,
6857                                                true, true);
6858
6859   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6860   // to these from the linked text sections.
6861   const unsigned char* ps = pshdrs + shdr_size;
6862   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6863     {
6864       elfcpp::Shdr<32, big_endian> shdr(ps);
6865       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6866         {
6867           // Found an .ARM.exidx section, add it to the set of reachable
6868           // sections from its linked text section.
6869           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6870           symtab->gc()->add_reference(this, text_shndx, this, i);
6871         }
6872     }
6873 }
6874
6875 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6876 // symbols  will be removed in output.  Adjust output local symbol count
6877 // accordingly.  We can only changed the static output local symbol count.  It
6878 // is too late to change the dynamic symbols.
6879
6880 template<bool big_endian>
6881 void
6882 Arm_relobj<big_endian>::update_output_local_symbol_count()
6883 {
6884   // Caller should check that this needs updating.  We want caller checking
6885   // because output_local_symbol_count_needs_update() is most likely inlined.
6886   gold_assert(this->output_local_symbol_count_needs_update_);
6887
6888   gold_assert(this->symtab_shndx() != -1U);
6889   if (this->symtab_shndx() == 0)
6890     {
6891       // This object has no symbols.  Weird but legal.
6892       return;
6893     }
6894
6895   // Read the symbol table section header.
6896   const unsigned int symtab_shndx = this->symtab_shndx();
6897   elfcpp::Shdr<32, big_endian>
6898     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6899   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6900
6901   // Read the local symbols.
6902   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6903   const unsigned int loccount = this->local_symbol_count();
6904   gold_assert(loccount == symtabshdr.get_sh_info());
6905   off_t locsize = loccount * sym_size;
6906   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6907                                               locsize, true, true);
6908
6909   // Loop over the local symbols.
6910
6911   typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6912      Output_sections;
6913   const Output_sections& out_sections(this->output_sections());
6914   unsigned int shnum = this->shnum();
6915   unsigned int count = 0;
6916   // Skip the first, dummy, symbol.
6917   psyms += sym_size;
6918   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6919     {
6920       elfcpp::Sym<32, big_endian> sym(psyms);
6921
6922       Symbol_value<32>& lv((*this->local_values())[i]);
6923
6924       // This local symbol was already discarded by do_count_local_symbols.
6925       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6926         continue;
6927
6928       bool is_ordinary;
6929       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6930                                                   &is_ordinary);
6931
6932       if (shndx < shnum)
6933         {
6934           Output_section* os = out_sections[shndx];
6935
6936           // This local symbol no longer has an output section.  Discard it.
6937           if (os == NULL)
6938             {
6939               lv.set_no_output_symtab_entry();
6940               continue;
6941             }
6942
6943           // Currently we only discard parts of EXIDX input sections.
6944           // We explicitly check for a merged EXIDX input section to avoid
6945           // calling Output_section_data::output_offset unless necessary.
6946           if ((this->get_output_section_offset(shndx) == invalid_address)
6947               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6948             {
6949               section_offset_type output_offset =
6950                 os->output_offset(this, shndx, lv.input_value());
6951               if (output_offset == -1)
6952                 {
6953                   // This symbol is defined in a part of an EXIDX input section
6954                   // that is discarded due to entry merging.
6955                   lv.set_no_output_symtab_entry();
6956                   continue;
6957                 }
6958             }
6959         }
6960
6961       ++count;
6962     }
6963
6964   this->set_output_local_symbol_count(count);
6965   this->output_local_symbol_count_needs_update_ = false;
6966 }
6967
6968 // Arm_dynobj methods.
6969
6970 // Read the symbol information.
6971
6972 template<bool big_endian>
6973 void
6974 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6975 {
6976   // Call parent class to read symbol information.
6977   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6978
6979   // Read processor-specific flags in ELF file header.
6980   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6981                                               elfcpp::Elf_sizes<32>::ehdr_size,
6982                                               true, false);
6983   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6984   this->processor_specific_flags_ = ehdr.get_e_flags();
6985
6986   // Read the attributes section if there is one.
6987   // We read from the end because gas seems to put it near the end of
6988   // the section headers.
6989   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6990   const unsigned char* ps =
6991     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6992   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6993     {
6994       elfcpp::Shdr<32, big_endian> shdr(ps);
6995       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6996         {
6997           section_offset_type section_offset = shdr.get_sh_offset();
6998           section_size_type section_size =
6999             convert_to_section_size_type(shdr.get_sh_size());
7000           const unsigned char* view =
7001             this->get_view(section_offset, section_size, true, false);
7002           this->attributes_section_data_ =
7003             new Attributes_section_data(view, section_size);
7004           break;
7005         }
7006     }
7007 }
7008
7009 // Stub_addend_reader methods.
7010
7011 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7012
7013 template<bool big_endian>
7014 elfcpp::Elf_types<32>::Elf_Swxword
7015 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7016     unsigned int r_type,
7017     const unsigned char* view,
7018     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7019 {
7020   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7021
7022   switch (r_type)
7023     {
7024     case elfcpp::R_ARM_CALL:
7025     case elfcpp::R_ARM_JUMP24:
7026     case elfcpp::R_ARM_PLT32:
7027       {
7028         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7029         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7030         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7031         return Bits<26>::sign_extend32(val << 2);
7032       }
7033
7034     case elfcpp::R_ARM_THM_CALL:
7035     case elfcpp::R_ARM_THM_JUMP24:
7036     case elfcpp::R_ARM_THM_XPC22:
7037       {
7038         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7039         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7040         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7041         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7042         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7043       }
7044
7045     case elfcpp::R_ARM_THM_JUMP19:
7046       {
7047         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7048         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7049         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7050         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7051         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7052       }
7053
7054     default:
7055       gold_unreachable();
7056     }
7057 }
7058
7059 // Arm_output_data_got methods.
7060
7061 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
7062 // The first one is initialized to be 1, which is the module index for
7063 // the main executable and the second one 0.  A reloc of the type
7064 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7065 // be applied by gold.  GSYM is a global symbol.
7066 //
7067 template<bool big_endian>
7068 void
7069 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7070     unsigned int got_type,
7071     Symbol* gsym)
7072 {
7073   if (gsym->has_got_offset(got_type))
7074     return;
7075
7076   // We are doing a static link.  Just mark it as belong to module 1,
7077   // the executable.
7078   unsigned int got_offset = this->add_constant(1);
7079   gsym->set_got_offset(got_type, got_offset);
7080   got_offset = this->add_constant(0);
7081   this->static_relocs_.push_back(Static_reloc(got_offset,
7082                                               elfcpp::R_ARM_TLS_DTPOFF32,
7083                                               gsym));
7084 }
7085
7086 // Same as the above but for a local symbol.
7087
7088 template<bool big_endian>
7089 void
7090 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7091   unsigned int got_type,
7092   Sized_relobj_file<32, big_endian>* object,
7093   unsigned int index)
7094 {
7095   if (object->local_has_got_offset(index, got_type))
7096     return;
7097
7098   // We are doing a static link.  Just mark it as belong to module 1,
7099   // the executable.
7100   unsigned int got_offset = this->add_constant(1);
7101   object->set_local_got_offset(index, got_type, got_offset);
7102   got_offset = this->add_constant(0);
7103   this->static_relocs_.push_back(Static_reloc(got_offset,
7104                                               elfcpp::R_ARM_TLS_DTPOFF32,
7105                                               object, index));
7106 }
7107
7108 template<bool big_endian>
7109 void
7110 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7111 {
7112   // Call parent to write out GOT.
7113   Output_data_got<32, big_endian>::do_write(of);
7114
7115   // We are done if there is no fix up.
7116   if (this->static_relocs_.empty())
7117     return;
7118
7119   gold_assert(parameters->doing_static_link());
7120
7121   const off_t offset = this->offset();
7122   const section_size_type oview_size =
7123     convert_to_section_size_type(this->data_size());
7124   unsigned char* const oview = of->get_output_view(offset, oview_size);
7125
7126   Output_segment* tls_segment = this->layout_->tls_segment();
7127   gold_assert(tls_segment != NULL);
7128
7129   // The thread pointer $tp points to the TCB, which is followed by the
7130   // TLS.  So we need to adjust $tp relative addressing by this amount.
7131   Arm_address aligned_tcb_size =
7132     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7133
7134   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7135     {
7136       Static_reloc& reloc(this->static_relocs_[i]);
7137
7138       Arm_address value;
7139       if (!reloc.symbol_is_global())
7140         {
7141           Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7142           const Symbol_value<32>* psymval =
7143             reloc.relobj()->local_symbol(reloc.index());
7144
7145           // We are doing static linking.  Issue an error and skip this
7146           // relocation if the symbol is undefined or in a discarded_section.
7147           bool is_ordinary;
7148           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7149           if ((shndx == elfcpp::SHN_UNDEF)
7150               || (is_ordinary
7151                   && shndx != elfcpp::SHN_UNDEF
7152                   && !object->is_section_included(shndx)
7153                   && !this->symbol_table_->is_section_folded(object, shndx)))
7154             {
7155               gold_error(_("undefined or discarded local symbol %u from "
7156                            " object %s in GOT"),
7157                          reloc.index(), reloc.relobj()->name().c_str());
7158               continue;
7159             }
7160
7161           value = psymval->value(object, 0);
7162         }
7163       else
7164         {
7165           const Symbol* gsym = reloc.symbol();
7166           gold_assert(gsym != NULL);
7167           if (gsym->is_forwarder())
7168             gsym = this->symbol_table_->resolve_forwards(gsym);
7169
7170           // We are doing static linking.  Issue an error and skip this
7171           // relocation if the symbol is undefined or in a discarded_section
7172           // unless it is a weakly_undefined symbol.
7173           if ((gsym->is_defined_in_discarded_section()
7174                || gsym->is_undefined())
7175               && !gsym->is_weak_undefined())
7176             {
7177               gold_error(_("undefined or discarded symbol %s in GOT"),
7178                          gsym->name());
7179               continue;
7180             }
7181
7182           if (!gsym->is_weak_undefined())
7183             {
7184               const Sized_symbol<32>* sym =
7185                 static_cast<const Sized_symbol<32>*>(gsym);
7186               value = sym->value();
7187             }
7188           else
7189               value = 0;
7190         }
7191
7192       unsigned got_offset = reloc.got_offset();
7193       gold_assert(got_offset < oview_size);
7194
7195       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7196       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7197       Valtype x;
7198       switch (reloc.r_type())
7199         {
7200         case elfcpp::R_ARM_TLS_DTPOFF32:
7201           x = value;
7202           break;
7203         case elfcpp::R_ARM_TLS_TPOFF32:
7204           x = value + aligned_tcb_size;
7205           break;
7206         default:
7207           gold_unreachable();
7208         }
7209       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7210     }
7211
7212   of->write_output_view(offset, oview_size, oview);
7213 }
7214
7215 // A class to handle the PLT data.
7216 // This is an abstract base class that handles most of the linker details
7217 // but does not know the actual contents of PLT entries.  The derived
7218 // classes below fill in those details.
7219
7220 template<bool big_endian>
7221 class Output_data_plt_arm : public Output_section_data
7222 {
7223  public:
7224   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7225     Reloc_section;
7226
7227   Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7228
7229   // Add an entry to the PLT.
7230   void
7231   add_entry(Symbol* gsym);
7232
7233   // Return the .rel.plt section data.
7234   const Reloc_section*
7235   rel_plt() const
7236   { return this->rel_; }
7237
7238   // Return the number of PLT entries.
7239   unsigned int
7240   entry_count() const
7241   { return this->count_; }
7242
7243   // Return the offset of the first non-reserved PLT entry.
7244   unsigned int
7245   first_plt_entry_offset() const
7246   { return this->do_first_plt_entry_offset(); }
7247
7248   // Return the size of a PLT entry.
7249   unsigned int
7250   get_plt_entry_size() const
7251   { return this->do_get_plt_entry_size(); }
7252
7253  protected:
7254   // Fill in the first PLT entry.
7255   void
7256   fill_first_plt_entry(unsigned char* pov,
7257                        Arm_address got_address,
7258                        Arm_address plt_address)
7259   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7260
7261   void
7262   fill_plt_entry(unsigned char* pov,
7263                  Arm_address got_address,
7264                  Arm_address plt_address,
7265                  unsigned int got_offset,
7266                  unsigned int plt_offset)
7267   { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7268
7269   virtual unsigned int
7270   do_first_plt_entry_offset() const = 0;
7271
7272   virtual unsigned int
7273   do_get_plt_entry_size() const = 0;
7274
7275   virtual void
7276   do_fill_first_plt_entry(unsigned char* pov,
7277                           Arm_address got_address,
7278                           Arm_address plt_address) = 0;
7279
7280   virtual void
7281   do_fill_plt_entry(unsigned char* pov,
7282                     Arm_address got_address,
7283                     Arm_address plt_address,
7284                     unsigned int got_offset,
7285                     unsigned int plt_offset) = 0;
7286
7287   void
7288   do_adjust_output_section(Output_section* os);
7289
7290   // Write to a map file.
7291   void
7292   do_print_to_mapfile(Mapfile* mapfile) const
7293   { mapfile->print_output_data(this, _("** PLT")); }
7294
7295  private:
7296   // Set the final size.
7297   void
7298   set_final_data_size()
7299   {
7300     this->set_data_size(this->first_plt_entry_offset()
7301                         + this->count_ * this->get_plt_entry_size());
7302   }
7303
7304   // Write out the PLT data.
7305   void
7306   do_write(Output_file*);
7307
7308   // The reloc section.
7309   Reloc_section* rel_;
7310   // The .got.plt section.
7311   Output_data_space* got_plt_;
7312   // The number of PLT entries.
7313   unsigned int count_;
7314 };
7315
7316 // Create the PLT section.  The ordinary .got section is an argument,
7317 // since we need to refer to the start.  We also create our own .got
7318 // section just for PLT entries.
7319
7320 template<bool big_endian>
7321 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7322                                                      uint64_t addralign,
7323                                                      Output_data_space* got_plt)
7324   : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7325 {
7326   this->rel_ = new Reloc_section(false);
7327   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7328                                   elfcpp::SHF_ALLOC, this->rel_,
7329                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7330 }
7331
7332 template<bool big_endian>
7333 void
7334 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7335 {
7336   os->set_entsize(0);
7337 }
7338
7339 // Add an entry to the PLT.
7340
7341 template<bool big_endian>
7342 void
7343 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7344 {
7345   gold_assert(!gsym->has_plt_offset());
7346
7347   // Note that when setting the PLT offset we skip the initial
7348   // reserved PLT entry.
7349   gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7350                        + this->first_plt_entry_offset());
7351
7352   ++this->count_;
7353
7354   section_offset_type got_offset = this->got_plt_->current_data_size();
7355
7356   // Every PLT entry needs a GOT entry which points back to the PLT
7357   // entry (this will be changed by the dynamic linker, normally
7358   // lazily when the function is called).
7359   this->got_plt_->set_current_data_size(got_offset + 4);
7360
7361   // Every PLT entry needs a reloc.
7362   gsym->set_needs_dynsym_entry();
7363   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7364                          got_offset);
7365
7366   // Note that we don't need to save the symbol.  The contents of the
7367   // PLT are independent of which symbols are used.  The symbols only
7368   // appear in the relocations.
7369 }
7370
7371 template<bool big_endian>
7372 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7373 {
7374  public:
7375   Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7376     : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7377   { }
7378
7379  protected:
7380   // Return the offset of the first non-reserved PLT entry.
7381   virtual unsigned int
7382   do_first_plt_entry_offset() const
7383   { return sizeof(first_plt_entry); }
7384
7385   // Return the size of a PLT entry.
7386   virtual unsigned int
7387   do_get_plt_entry_size() const
7388   { return sizeof(plt_entry); }
7389
7390   virtual void
7391   do_fill_first_plt_entry(unsigned char* pov,
7392                           Arm_address got_address,
7393                           Arm_address plt_address);
7394
7395   virtual void
7396   do_fill_plt_entry(unsigned char* pov,
7397                     Arm_address got_address,
7398                     Arm_address plt_address,
7399                     unsigned int got_offset,
7400                     unsigned int plt_offset);
7401
7402  private:
7403   // Template for the first PLT entry.
7404   static const uint32_t first_plt_entry[5];
7405
7406   // Template for subsequent PLT entries.
7407   static const uint32_t plt_entry[3];
7408 };
7409
7410 // ARM PLTs.
7411 // FIXME:  This is not very flexible.  Right now this has only been tested
7412 // on armv5te.  If we are to support additional architecture features like
7413 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7414
7415 // The first entry in the PLT.
7416 template<bool big_endian>
7417 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7418 {
7419   0xe52de004,   // str   lr, [sp, #-4]!
7420   0xe59fe004,   // ldr   lr, [pc, #4]
7421   0xe08fe00e,   // add   lr, pc, lr
7422   0xe5bef008,   // ldr   pc, [lr, #8]!
7423   0x00000000,   // &GOT[0] - .
7424 };
7425
7426 template<bool big_endian>
7427 void
7428 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7429     unsigned char* pov,
7430     Arm_address got_address,
7431     Arm_address plt_address)
7432 {
7433   // Write first PLT entry.  All but the last word are constants.
7434   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7435                                       / sizeof(plt_entry[0]));
7436   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7437     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7438   // Last word in first PLT entry is &GOT[0] - .
7439   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7440                                          got_address - (plt_address + 16));
7441 }
7442
7443 // Subsequent entries in the PLT.
7444
7445 template<bool big_endian>
7446 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7447 {
7448   0xe28fc600,   // add   ip, pc, #0xNN00000
7449   0xe28cca00,   // add   ip, ip, #0xNN000
7450   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7451 };
7452
7453 template<bool big_endian>
7454 void
7455 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7456     unsigned char* pov,
7457     Arm_address got_address,
7458     Arm_address plt_address,
7459     unsigned int got_offset,
7460     unsigned int plt_offset)
7461 {
7462   int32_t offset = ((got_address + got_offset)
7463                     - (plt_address + plt_offset + 8));
7464
7465   gold_assert(offset >= 0 && offset < 0x0fffffff);
7466   uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7467   elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7468   uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7469   elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7470   uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7471   elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7472 }
7473
7474 // Write out the PLT.  This uses the hand-coded instructions above,
7475 // and adjusts them as needed.  This is all specified by the arm ELF
7476 // Processor Supplement.
7477
7478 template<bool big_endian>
7479 void
7480 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7481 {
7482   const off_t offset = this->offset();
7483   const section_size_type oview_size =
7484     convert_to_section_size_type(this->data_size());
7485   unsigned char* const oview = of->get_output_view(offset, oview_size);
7486
7487   const off_t got_file_offset = this->got_plt_->offset();
7488   const section_size_type got_size =
7489     convert_to_section_size_type(this->got_plt_->data_size());
7490   unsigned char* const got_view = of->get_output_view(got_file_offset,
7491                                                       got_size);
7492   unsigned char* pov = oview;
7493
7494   Arm_address plt_address = this->address();
7495   Arm_address got_address = this->got_plt_->address();
7496
7497   // Write first PLT entry.
7498   this->fill_first_plt_entry(pov, got_address, plt_address);
7499   pov += this->first_plt_entry_offset();
7500
7501   unsigned char* got_pov = got_view;
7502
7503   memset(got_pov, 0, 12);
7504   got_pov += 12;
7505
7506   unsigned int plt_offset = this->first_plt_entry_offset();
7507   unsigned int got_offset = 12;
7508   const unsigned int count = this->count_;
7509   for (unsigned int i = 0;
7510        i < count;
7511        ++i,
7512          pov += this->get_plt_entry_size(),
7513          got_pov += 4,
7514          plt_offset += this->get_plt_entry_size(),
7515          got_offset += 4)
7516     {
7517       // Set and adjust the PLT entry itself.
7518       this->fill_plt_entry(pov, got_address, plt_address,
7519                            got_offset, plt_offset);
7520
7521       // Set the entry in the GOT.
7522       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7523     }
7524
7525   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7526   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7527
7528   of->write_output_view(offset, oview_size, oview);
7529   of->write_output_view(got_file_offset, got_size, got_view);
7530 }
7531
7532 // Create a PLT entry for a global symbol.
7533
7534 template<bool big_endian>
7535 void
7536 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7537                                        Symbol* gsym)
7538 {
7539   if (gsym->has_plt_offset())
7540     return;
7541
7542   if (this->plt_ == NULL)
7543     {
7544       // Create the GOT sections first.
7545       this->got_section(symtab, layout);
7546
7547       this->plt_ = this->make_data_plt(layout, this->got_plt_);
7548
7549       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7550                                       (elfcpp::SHF_ALLOC
7551                                        | elfcpp::SHF_EXECINSTR),
7552                                       this->plt_, ORDER_PLT, false);
7553     }
7554   this->plt_->add_entry(gsym);
7555 }
7556
7557 // Return the number of entries in the PLT.
7558
7559 template<bool big_endian>
7560 unsigned int
7561 Target_arm<big_endian>::plt_entry_count() const
7562 {
7563   if (this->plt_ == NULL)
7564     return 0;
7565   return this->plt_->entry_count();
7566 }
7567
7568 // Return the offset of the first non-reserved PLT entry.
7569
7570 template<bool big_endian>
7571 unsigned int
7572 Target_arm<big_endian>::first_plt_entry_offset() const
7573 {
7574   return this->plt_->first_plt_entry_offset();
7575 }
7576
7577 // Return the size of each PLT entry.
7578
7579 template<bool big_endian>
7580 unsigned int
7581 Target_arm<big_endian>::plt_entry_size() const
7582 {
7583   return this->plt_->get_plt_entry_size();
7584 }
7585
7586 // Get the section to use for TLS_DESC relocations.
7587
7588 template<bool big_endian>
7589 typename Target_arm<big_endian>::Reloc_section*
7590 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7591 {
7592   return this->plt_section()->rel_tls_desc(layout);
7593 }
7594
7595 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7596
7597 template<bool big_endian>
7598 void
7599 Target_arm<big_endian>::define_tls_base_symbol(
7600     Symbol_table* symtab,
7601     Layout* layout)
7602 {
7603   if (this->tls_base_symbol_defined_)
7604     return;
7605
7606   Output_segment* tls_segment = layout->tls_segment();
7607   if (tls_segment != NULL)
7608     {
7609       bool is_exec = parameters->options().output_is_executable();
7610       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7611                                        Symbol_table::PREDEFINED,
7612                                        tls_segment, 0, 0,
7613                                        elfcpp::STT_TLS,
7614                                        elfcpp::STB_LOCAL,
7615                                        elfcpp::STV_HIDDEN, 0,
7616                                        (is_exec
7617                                         ? Symbol::SEGMENT_END
7618                                         : Symbol::SEGMENT_START),
7619                                        true);
7620     }
7621   this->tls_base_symbol_defined_ = true;
7622 }
7623
7624 // Create a GOT entry for the TLS module index.
7625
7626 template<bool big_endian>
7627 unsigned int
7628 Target_arm<big_endian>::got_mod_index_entry(
7629     Symbol_table* symtab,
7630     Layout* layout,
7631     Sized_relobj_file<32, big_endian>* object)
7632 {
7633   if (this->got_mod_index_offset_ == -1U)
7634     {
7635       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7636       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7637       unsigned int got_offset;
7638       if (!parameters->doing_static_link())
7639         {
7640           got_offset = got->add_constant(0);
7641           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7642           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7643                              got_offset);
7644         }
7645       else
7646         {
7647           // We are doing a static link.  Just mark it as belong to module 1,
7648           // the executable.
7649           got_offset = got->add_constant(1);
7650         }
7651
7652       got->add_constant(0);
7653       this->got_mod_index_offset_ = got_offset;
7654     }
7655   return this->got_mod_index_offset_;
7656 }
7657
7658 // Optimize the TLS relocation type based on what we know about the
7659 // symbol.  IS_FINAL is true if the final address of this symbol is
7660 // known at link time.
7661
7662 template<bool big_endian>
7663 tls::Tls_optimization
7664 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7665 {
7666   // FIXME: Currently we do not do any TLS optimization.
7667   return tls::TLSOPT_NONE;
7668 }
7669
7670 // Get the Reference_flags for a particular relocation.
7671
7672 template<bool big_endian>
7673 int
7674 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7675 {
7676   switch (r_type)
7677     {
7678     case elfcpp::R_ARM_NONE:
7679     case elfcpp::R_ARM_V4BX:
7680     case elfcpp::R_ARM_GNU_VTENTRY:
7681     case elfcpp::R_ARM_GNU_VTINHERIT:
7682       // No symbol reference.
7683       return 0;
7684
7685     case elfcpp::R_ARM_ABS32:
7686     case elfcpp::R_ARM_ABS16:
7687     case elfcpp::R_ARM_ABS12:
7688     case elfcpp::R_ARM_THM_ABS5:
7689     case elfcpp::R_ARM_ABS8:
7690     case elfcpp::R_ARM_BASE_ABS:
7691     case elfcpp::R_ARM_MOVW_ABS_NC:
7692     case elfcpp::R_ARM_MOVT_ABS:
7693     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7694     case elfcpp::R_ARM_THM_MOVT_ABS:
7695     case elfcpp::R_ARM_ABS32_NOI:
7696       return Symbol::ABSOLUTE_REF;
7697
7698     case elfcpp::R_ARM_REL32:
7699     case elfcpp::R_ARM_LDR_PC_G0:
7700     case elfcpp::R_ARM_SBREL32:
7701     case elfcpp::R_ARM_THM_PC8:
7702     case elfcpp::R_ARM_BASE_PREL:
7703     case elfcpp::R_ARM_MOVW_PREL_NC:
7704     case elfcpp::R_ARM_MOVT_PREL:
7705     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7706     case elfcpp::R_ARM_THM_MOVT_PREL:
7707     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7708     case elfcpp::R_ARM_THM_PC12:
7709     case elfcpp::R_ARM_REL32_NOI:
7710     case elfcpp::R_ARM_ALU_PC_G0_NC:
7711     case elfcpp::R_ARM_ALU_PC_G0:
7712     case elfcpp::R_ARM_ALU_PC_G1_NC:
7713     case elfcpp::R_ARM_ALU_PC_G1:
7714     case elfcpp::R_ARM_ALU_PC_G2:
7715     case elfcpp::R_ARM_LDR_PC_G1:
7716     case elfcpp::R_ARM_LDR_PC_G2:
7717     case elfcpp::R_ARM_LDRS_PC_G0:
7718     case elfcpp::R_ARM_LDRS_PC_G1:
7719     case elfcpp::R_ARM_LDRS_PC_G2:
7720     case elfcpp::R_ARM_LDC_PC_G0:
7721     case elfcpp::R_ARM_LDC_PC_G1:
7722     case elfcpp::R_ARM_LDC_PC_G2:
7723     case elfcpp::R_ARM_ALU_SB_G0_NC:
7724     case elfcpp::R_ARM_ALU_SB_G0:
7725     case elfcpp::R_ARM_ALU_SB_G1_NC:
7726     case elfcpp::R_ARM_ALU_SB_G1:
7727     case elfcpp::R_ARM_ALU_SB_G2:
7728     case elfcpp::R_ARM_LDR_SB_G0:
7729     case elfcpp::R_ARM_LDR_SB_G1:
7730     case elfcpp::R_ARM_LDR_SB_G2:
7731     case elfcpp::R_ARM_LDRS_SB_G0:
7732     case elfcpp::R_ARM_LDRS_SB_G1:
7733     case elfcpp::R_ARM_LDRS_SB_G2:
7734     case elfcpp::R_ARM_LDC_SB_G0:
7735     case elfcpp::R_ARM_LDC_SB_G1:
7736     case elfcpp::R_ARM_LDC_SB_G2:
7737     case elfcpp::R_ARM_MOVW_BREL_NC:
7738     case elfcpp::R_ARM_MOVT_BREL:
7739     case elfcpp::R_ARM_MOVW_BREL:
7740     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7741     case elfcpp::R_ARM_THM_MOVT_BREL:
7742     case elfcpp::R_ARM_THM_MOVW_BREL:
7743     case elfcpp::R_ARM_GOTOFF32:
7744     case elfcpp::R_ARM_GOTOFF12:
7745     case elfcpp::R_ARM_SBREL31:
7746       return Symbol::RELATIVE_REF;
7747
7748     case elfcpp::R_ARM_PLT32:
7749     case elfcpp::R_ARM_CALL:
7750     case elfcpp::R_ARM_JUMP24:
7751     case elfcpp::R_ARM_THM_CALL:
7752     case elfcpp::R_ARM_THM_JUMP24:
7753     case elfcpp::R_ARM_THM_JUMP19:
7754     case elfcpp::R_ARM_THM_JUMP6:
7755     case elfcpp::R_ARM_THM_JUMP11:
7756     case elfcpp::R_ARM_THM_JUMP8:
7757     // R_ARM_PREL31 is not used to relocate call/jump instructions but
7758     // in unwind tables. It may point to functions via PLTs.
7759     // So we treat it like call/jump relocations above.
7760     case elfcpp::R_ARM_PREL31:
7761       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7762
7763     case elfcpp::R_ARM_GOT_BREL:
7764     case elfcpp::R_ARM_GOT_ABS:
7765     case elfcpp::R_ARM_GOT_PREL:
7766       // Absolute in GOT.
7767       return Symbol::ABSOLUTE_REF;
7768
7769     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7770     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7771     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7772     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7773     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7774       return Symbol::TLS_REF;
7775
7776     case elfcpp::R_ARM_TARGET1:
7777     case elfcpp::R_ARM_TARGET2:
7778     case elfcpp::R_ARM_COPY:
7779     case elfcpp::R_ARM_GLOB_DAT:
7780     case elfcpp::R_ARM_JUMP_SLOT:
7781     case elfcpp::R_ARM_RELATIVE:
7782     case elfcpp::R_ARM_PC24:
7783     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7784     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7785     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7786     default:
7787       // Not expected.  We will give an error later.
7788       return 0;
7789     }
7790 }
7791
7792 // Report an unsupported relocation against a local symbol.
7793
7794 template<bool big_endian>
7795 void
7796 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7797     Sized_relobj_file<32, big_endian>* object,
7798     unsigned int r_type)
7799 {
7800   gold_error(_("%s: unsupported reloc %u against local symbol"),
7801              object->name().c_str(), r_type);
7802 }
7803
7804 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7805 // dynamic linker does not support it, issue an error.  The GNU linker
7806 // only issues a non-PIC error for an allocated read-only section.
7807 // Here we know the section is allocated, but we don't know that it is
7808 // read-only.  But we check for all the relocation types which the
7809 // glibc dynamic linker supports, so it seems appropriate to issue an
7810 // error even if the section is not read-only.
7811
7812 template<bool big_endian>
7813 void
7814 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7815                                             unsigned int r_type)
7816 {
7817   switch (r_type)
7818     {
7819     // These are the relocation types supported by glibc for ARM.
7820     case elfcpp::R_ARM_RELATIVE:
7821     case elfcpp::R_ARM_COPY:
7822     case elfcpp::R_ARM_GLOB_DAT:
7823     case elfcpp::R_ARM_JUMP_SLOT:
7824     case elfcpp::R_ARM_ABS32:
7825     case elfcpp::R_ARM_ABS32_NOI:
7826     case elfcpp::R_ARM_PC24:
7827     // FIXME: The following 3 types are not supported by Android's dynamic
7828     // linker.
7829     case elfcpp::R_ARM_TLS_DTPMOD32:
7830     case elfcpp::R_ARM_TLS_DTPOFF32:
7831     case elfcpp::R_ARM_TLS_TPOFF32:
7832       return;
7833
7834     default:
7835       {
7836         // This prevents us from issuing more than one error per reloc
7837         // section.  But we can still wind up issuing more than one
7838         // error per object file.
7839         if (this->issued_non_pic_error_)
7840           return;
7841         const Arm_reloc_property* reloc_property =
7842           arm_reloc_property_table->get_reloc_property(r_type);
7843         gold_assert(reloc_property != NULL);
7844         object->error(_("requires unsupported dynamic reloc %s; "
7845                       "recompile with -fPIC"),
7846                       reloc_property->name().c_str());
7847         this->issued_non_pic_error_ = true;
7848         return;
7849       }
7850
7851     case elfcpp::R_ARM_NONE:
7852       gold_unreachable();
7853     }
7854 }
7855
7856 // Scan a relocation for a local symbol.
7857 // FIXME: This only handles a subset of relocation types used by Android
7858 // on ARM v5te devices.
7859
7860 template<bool big_endian>
7861 inline void
7862 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7863                                     Layout* layout,
7864                                     Target_arm* target,
7865                                     Sized_relobj_file<32, big_endian>* object,
7866                                     unsigned int data_shndx,
7867                                     Output_section* output_section,
7868                                     const elfcpp::Rel<32, big_endian>& reloc,
7869                                     unsigned int r_type,
7870                                     const elfcpp::Sym<32, big_endian>& lsym,
7871                                     bool is_discarded)
7872 {
7873   if (is_discarded)
7874     return;
7875
7876   r_type = get_real_reloc_type(r_type);
7877   switch (r_type)
7878     {
7879     case elfcpp::R_ARM_NONE:
7880     case elfcpp::R_ARM_V4BX:
7881     case elfcpp::R_ARM_GNU_VTENTRY:
7882     case elfcpp::R_ARM_GNU_VTINHERIT:
7883       break;
7884
7885     case elfcpp::R_ARM_ABS32:
7886     case elfcpp::R_ARM_ABS32_NOI:
7887       // If building a shared library (or a position-independent
7888       // executable), we need to create a dynamic relocation for
7889       // this location. The relocation applied at link time will
7890       // apply the link-time value, so we flag the location with
7891       // an R_ARM_RELATIVE relocation so the dynamic loader can
7892       // relocate it easily.
7893       if (parameters->options().output_is_position_independent())
7894         {
7895           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7896           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7897           // If we are to add more other reloc types than R_ARM_ABS32,
7898           // we need to add check_non_pic(object, r_type) here.
7899           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7900                                       output_section, data_shndx,
7901                                       reloc.get_r_offset());
7902         }
7903       break;
7904
7905     case elfcpp::R_ARM_ABS16:
7906     case elfcpp::R_ARM_ABS12:
7907     case elfcpp::R_ARM_THM_ABS5:
7908     case elfcpp::R_ARM_ABS8:
7909     case elfcpp::R_ARM_BASE_ABS:
7910     case elfcpp::R_ARM_MOVW_ABS_NC:
7911     case elfcpp::R_ARM_MOVT_ABS:
7912     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7913     case elfcpp::R_ARM_THM_MOVT_ABS:
7914       // If building a shared library (or a position-independent
7915       // executable), we need to create a dynamic relocation for
7916       // this location. Because the addend needs to remain in the
7917       // data section, we need to be careful not to apply this
7918       // relocation statically.
7919       if (parameters->options().output_is_position_independent())
7920         {
7921           check_non_pic(object, r_type);
7922           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7923           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7924           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7925             rel_dyn->add_local(object, r_sym, r_type, output_section,
7926                                data_shndx, reloc.get_r_offset());
7927           else
7928             {
7929               gold_assert(lsym.get_st_value() == 0);
7930               unsigned int shndx = lsym.get_st_shndx();
7931               bool is_ordinary;
7932               shndx = object->adjust_sym_shndx(r_sym, shndx,
7933                                                &is_ordinary);
7934               if (!is_ordinary)
7935                 object->error(_("section symbol %u has bad shndx %u"),
7936                               r_sym, shndx);
7937               else
7938                 rel_dyn->add_local_section(object, shndx,
7939                                            r_type, output_section,
7940                                            data_shndx, reloc.get_r_offset());
7941             }
7942         }
7943       break;
7944
7945     case elfcpp::R_ARM_REL32:
7946     case elfcpp::R_ARM_LDR_PC_G0:
7947     case elfcpp::R_ARM_SBREL32:
7948     case elfcpp::R_ARM_THM_CALL:
7949     case elfcpp::R_ARM_THM_PC8:
7950     case elfcpp::R_ARM_BASE_PREL:
7951     case elfcpp::R_ARM_PLT32:
7952     case elfcpp::R_ARM_CALL:
7953     case elfcpp::R_ARM_JUMP24:
7954     case elfcpp::R_ARM_THM_JUMP24:
7955     case elfcpp::R_ARM_SBREL31:
7956     case elfcpp::R_ARM_PREL31:
7957     case elfcpp::R_ARM_MOVW_PREL_NC:
7958     case elfcpp::R_ARM_MOVT_PREL:
7959     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7960     case elfcpp::R_ARM_THM_MOVT_PREL:
7961     case elfcpp::R_ARM_THM_JUMP19:
7962     case elfcpp::R_ARM_THM_JUMP6:
7963     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7964     case elfcpp::R_ARM_THM_PC12:
7965     case elfcpp::R_ARM_REL32_NOI:
7966     case elfcpp::R_ARM_ALU_PC_G0_NC:
7967     case elfcpp::R_ARM_ALU_PC_G0:
7968     case elfcpp::R_ARM_ALU_PC_G1_NC:
7969     case elfcpp::R_ARM_ALU_PC_G1:
7970     case elfcpp::R_ARM_ALU_PC_G2:
7971     case elfcpp::R_ARM_LDR_PC_G1:
7972     case elfcpp::R_ARM_LDR_PC_G2:
7973     case elfcpp::R_ARM_LDRS_PC_G0:
7974     case elfcpp::R_ARM_LDRS_PC_G1:
7975     case elfcpp::R_ARM_LDRS_PC_G2:
7976     case elfcpp::R_ARM_LDC_PC_G0:
7977     case elfcpp::R_ARM_LDC_PC_G1:
7978     case elfcpp::R_ARM_LDC_PC_G2:
7979     case elfcpp::R_ARM_ALU_SB_G0_NC:
7980     case elfcpp::R_ARM_ALU_SB_G0:
7981     case elfcpp::R_ARM_ALU_SB_G1_NC:
7982     case elfcpp::R_ARM_ALU_SB_G1:
7983     case elfcpp::R_ARM_ALU_SB_G2:
7984     case elfcpp::R_ARM_LDR_SB_G0:
7985     case elfcpp::R_ARM_LDR_SB_G1:
7986     case elfcpp::R_ARM_LDR_SB_G2:
7987     case elfcpp::R_ARM_LDRS_SB_G0:
7988     case elfcpp::R_ARM_LDRS_SB_G1:
7989     case elfcpp::R_ARM_LDRS_SB_G2:
7990     case elfcpp::R_ARM_LDC_SB_G0:
7991     case elfcpp::R_ARM_LDC_SB_G1:
7992     case elfcpp::R_ARM_LDC_SB_G2:
7993     case elfcpp::R_ARM_MOVW_BREL_NC:
7994     case elfcpp::R_ARM_MOVT_BREL:
7995     case elfcpp::R_ARM_MOVW_BREL:
7996     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7997     case elfcpp::R_ARM_THM_MOVT_BREL:
7998     case elfcpp::R_ARM_THM_MOVW_BREL:
7999     case elfcpp::R_ARM_THM_JUMP11:
8000     case elfcpp::R_ARM_THM_JUMP8:
8001       // We don't need to do anything for a relative addressing relocation
8002       // against a local symbol if it does not reference the GOT.
8003       break;
8004
8005     case elfcpp::R_ARM_GOTOFF32:
8006     case elfcpp::R_ARM_GOTOFF12:
8007       // We need a GOT section:
8008       target->got_section(symtab, layout);
8009       break;
8010
8011     case elfcpp::R_ARM_GOT_BREL:
8012     case elfcpp::R_ARM_GOT_PREL:
8013       {
8014         // The symbol requires a GOT entry.
8015         Arm_output_data_got<big_endian>* got =
8016           target->got_section(symtab, layout);
8017         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8018         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8019           {
8020             // If we are generating a shared object, we need to add a
8021             // dynamic RELATIVE relocation for this symbol's GOT entry.
8022             if (parameters->options().output_is_position_independent())
8023               {
8024                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8025                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8026                 rel_dyn->add_local_relative(
8027                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8028                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8029               }
8030           }
8031       }
8032       break;
8033
8034     case elfcpp::R_ARM_TARGET1:
8035     case elfcpp::R_ARM_TARGET2:
8036       // This should have been mapped to another type already.
8037       // Fall through.
8038     case elfcpp::R_ARM_COPY:
8039     case elfcpp::R_ARM_GLOB_DAT:
8040     case elfcpp::R_ARM_JUMP_SLOT:
8041     case elfcpp::R_ARM_RELATIVE:
8042       // These are relocations which should only be seen by the
8043       // dynamic linker, and should never be seen here.
8044       gold_error(_("%s: unexpected reloc %u in object file"),
8045                  object->name().c_str(), r_type);
8046       break;
8047
8048
8049       // These are initial TLS relocs, which are expected when
8050       // linking.
8051     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8052     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8053     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8054     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8055     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8056       {
8057         bool output_is_shared = parameters->options().shared();
8058         const tls::Tls_optimization optimized_type
8059             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8060                                                          r_type);
8061         switch (r_type)
8062           {
8063           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8064             if (optimized_type == tls::TLSOPT_NONE)
8065               {
8066                 // Create a pair of GOT entries for the module index and
8067                 // dtv-relative offset.
8068                 Arm_output_data_got<big_endian>* got
8069                     = target->got_section(symtab, layout);
8070                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8071                 unsigned int shndx = lsym.get_st_shndx();
8072                 bool is_ordinary;
8073                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8074                 if (!is_ordinary)
8075                   {
8076                     object->error(_("local symbol %u has bad shndx %u"),
8077                                   r_sym, shndx);
8078                     break;
8079                   }
8080
8081                 if (!parameters->doing_static_link())
8082                   got->add_local_pair_with_rel(object, r_sym, shndx,
8083                                                GOT_TYPE_TLS_PAIR,
8084                                                target->rel_dyn_section(layout),
8085                                                elfcpp::R_ARM_TLS_DTPMOD32);
8086                 else
8087                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8088                                                       object, r_sym);
8089               }
8090             else
8091               // FIXME: TLS optimization not supported yet.
8092               gold_unreachable();
8093             break;
8094
8095           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8096             if (optimized_type == tls::TLSOPT_NONE)
8097               {
8098                 // Create a GOT entry for the module index.
8099                 target->got_mod_index_entry(symtab, layout, object);
8100               }
8101             else
8102               // FIXME: TLS optimization not supported yet.
8103               gold_unreachable();
8104             break;
8105
8106           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8107             break;
8108
8109           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8110             layout->set_has_static_tls();
8111             if (optimized_type == tls::TLSOPT_NONE)
8112               {
8113                 // Create a GOT entry for the tp-relative offset.
8114                 Arm_output_data_got<big_endian>* got
8115                   = target->got_section(symtab, layout);
8116                 unsigned int r_sym =
8117                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
8118                 if (!parameters->doing_static_link())
8119                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8120                                             target->rel_dyn_section(layout),
8121                                             elfcpp::R_ARM_TLS_TPOFF32);
8122                 else if (!object->local_has_got_offset(r_sym,
8123                                                        GOT_TYPE_TLS_OFFSET))
8124                   {
8125                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8126                     unsigned int got_offset =
8127                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8128                     got->add_static_reloc(got_offset,
8129                                           elfcpp::R_ARM_TLS_TPOFF32, object,
8130                                           r_sym);
8131                   }
8132               }
8133             else
8134               // FIXME: TLS optimization not supported yet.
8135               gold_unreachable();
8136             break;
8137
8138           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
8139             layout->set_has_static_tls();
8140             if (output_is_shared)
8141               {
8142                 // We need to create a dynamic relocation.
8143                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8144                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8145                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8146                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8147                                    output_section, data_shndx,
8148                                    reloc.get_r_offset());
8149               }
8150             break;
8151
8152           default:
8153             gold_unreachable();
8154           }
8155       }
8156       break;
8157
8158     case elfcpp::R_ARM_PC24:
8159     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8160     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8161     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8162     default:
8163       unsupported_reloc_local(object, r_type);
8164       break;
8165     }
8166 }
8167
8168 // Report an unsupported relocation against a global symbol.
8169
8170 template<bool big_endian>
8171 void
8172 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8173     Sized_relobj_file<32, big_endian>* object,
8174     unsigned int r_type,
8175     Symbol* gsym)
8176 {
8177   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8178              object->name().c_str(), r_type, gsym->demangled_name().c_str());
8179 }
8180
8181 template<bool big_endian>
8182 inline bool
8183 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8184     unsigned int r_type)
8185 {
8186   switch (r_type)
8187     {
8188     case elfcpp::R_ARM_PC24:
8189     case elfcpp::R_ARM_THM_CALL:
8190     case elfcpp::R_ARM_PLT32:
8191     case elfcpp::R_ARM_CALL:
8192     case elfcpp::R_ARM_JUMP24:
8193     case elfcpp::R_ARM_THM_JUMP24:
8194     case elfcpp::R_ARM_SBREL31:
8195     case elfcpp::R_ARM_PREL31:
8196     case elfcpp::R_ARM_THM_JUMP19:
8197     case elfcpp::R_ARM_THM_JUMP6:
8198     case elfcpp::R_ARM_THM_JUMP11:
8199     case elfcpp::R_ARM_THM_JUMP8:
8200       // All the relocations above are branches except SBREL31 and PREL31.
8201       return false;
8202
8203     default:
8204       // Be conservative and assume this is a function pointer.
8205       return true;
8206     }
8207 }
8208
8209 template<bool big_endian>
8210 inline bool
8211 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8212   Symbol_table*,
8213   Layout*,
8214   Target_arm<big_endian>* target,
8215   Sized_relobj_file<32, big_endian>*,
8216   unsigned int,
8217   Output_section*,
8218   const elfcpp::Rel<32, big_endian>&,
8219   unsigned int r_type,
8220   const elfcpp::Sym<32, big_endian>&)
8221 {
8222   r_type = target->get_real_reloc_type(r_type);
8223   return possible_function_pointer_reloc(r_type);
8224 }
8225
8226 template<bool big_endian>
8227 inline bool
8228 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8229   Symbol_table*,
8230   Layout*,
8231   Target_arm<big_endian>* target,
8232   Sized_relobj_file<32, big_endian>*,
8233   unsigned int,
8234   Output_section*,
8235   const elfcpp::Rel<32, big_endian>&,
8236   unsigned int r_type,
8237   Symbol* gsym)
8238 {
8239   // GOT is not a function.
8240   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8241     return false;
8242
8243   r_type = target->get_real_reloc_type(r_type);
8244   return possible_function_pointer_reloc(r_type);
8245 }
8246
8247 // Scan a relocation for a global symbol.
8248
8249 template<bool big_endian>
8250 inline void
8251 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8252                                      Layout* layout,
8253                                      Target_arm* target,
8254                                      Sized_relobj_file<32, big_endian>* object,
8255                                      unsigned int data_shndx,
8256                                      Output_section* output_section,
8257                                      const elfcpp::Rel<32, big_endian>& reloc,
8258                                      unsigned int r_type,
8259                                      Symbol* gsym)
8260 {
8261   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8262   // section.  We check here to avoid creating a dynamic reloc against
8263   // _GLOBAL_OFFSET_TABLE_.
8264   if (!target->has_got_section()
8265       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8266     target->got_section(symtab, layout);
8267
8268   r_type = get_real_reloc_type(r_type);
8269   switch (r_type)
8270     {
8271     case elfcpp::R_ARM_NONE:
8272     case elfcpp::R_ARM_V4BX:
8273     case elfcpp::R_ARM_GNU_VTENTRY:
8274     case elfcpp::R_ARM_GNU_VTINHERIT:
8275       break;
8276
8277     case elfcpp::R_ARM_ABS32:
8278     case elfcpp::R_ARM_ABS16:
8279     case elfcpp::R_ARM_ABS12:
8280     case elfcpp::R_ARM_THM_ABS5:
8281     case elfcpp::R_ARM_ABS8:
8282     case elfcpp::R_ARM_BASE_ABS:
8283     case elfcpp::R_ARM_MOVW_ABS_NC:
8284     case elfcpp::R_ARM_MOVT_ABS:
8285     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8286     case elfcpp::R_ARM_THM_MOVT_ABS:
8287     case elfcpp::R_ARM_ABS32_NOI:
8288       // Absolute addressing relocations.
8289       {
8290         // Make a PLT entry if necessary.
8291         if (this->symbol_needs_plt_entry(gsym))
8292           {
8293             target->make_plt_entry(symtab, layout, gsym);
8294             // Since this is not a PC-relative relocation, we may be
8295             // taking the address of a function. In that case we need to
8296             // set the entry in the dynamic symbol table to the address of
8297             // the PLT entry.
8298             if (gsym->is_from_dynobj() && !parameters->options().shared())
8299               gsym->set_needs_dynsym_value();
8300           }
8301         // Make a dynamic relocation if necessary.
8302         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8303           {
8304             if (gsym->may_need_copy_reloc())
8305               {
8306                 target->copy_reloc(symtab, layout, object,
8307                                    data_shndx, output_section, gsym, reloc);
8308               }
8309             else if ((r_type == elfcpp::R_ARM_ABS32
8310                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8311                      && gsym->can_use_relative_reloc(false))
8312               {
8313                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8314                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8315                                              output_section, object,
8316                                              data_shndx, reloc.get_r_offset());
8317               }
8318             else
8319               {
8320                 check_non_pic(object, r_type);
8321                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8322                 rel_dyn->add_global(gsym, r_type, output_section, object,
8323                                     data_shndx, reloc.get_r_offset());
8324               }
8325           }
8326       }
8327       break;
8328
8329     case elfcpp::R_ARM_GOTOFF32:
8330     case elfcpp::R_ARM_GOTOFF12:
8331       // We need a GOT section.
8332       target->got_section(symtab, layout);
8333       break;
8334
8335     case elfcpp::R_ARM_REL32:
8336     case elfcpp::R_ARM_LDR_PC_G0:
8337     case elfcpp::R_ARM_SBREL32:
8338     case elfcpp::R_ARM_THM_PC8:
8339     case elfcpp::R_ARM_BASE_PREL:
8340     case elfcpp::R_ARM_MOVW_PREL_NC:
8341     case elfcpp::R_ARM_MOVT_PREL:
8342     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8343     case elfcpp::R_ARM_THM_MOVT_PREL:
8344     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8345     case elfcpp::R_ARM_THM_PC12:
8346     case elfcpp::R_ARM_REL32_NOI:
8347     case elfcpp::R_ARM_ALU_PC_G0_NC:
8348     case elfcpp::R_ARM_ALU_PC_G0:
8349     case elfcpp::R_ARM_ALU_PC_G1_NC:
8350     case elfcpp::R_ARM_ALU_PC_G1:
8351     case elfcpp::R_ARM_ALU_PC_G2:
8352     case elfcpp::R_ARM_LDR_PC_G1:
8353     case elfcpp::R_ARM_LDR_PC_G2:
8354     case elfcpp::R_ARM_LDRS_PC_G0:
8355     case elfcpp::R_ARM_LDRS_PC_G1:
8356     case elfcpp::R_ARM_LDRS_PC_G2:
8357     case elfcpp::R_ARM_LDC_PC_G0:
8358     case elfcpp::R_ARM_LDC_PC_G1:
8359     case elfcpp::R_ARM_LDC_PC_G2:
8360     case elfcpp::R_ARM_ALU_SB_G0_NC:
8361     case elfcpp::R_ARM_ALU_SB_G0:
8362     case elfcpp::R_ARM_ALU_SB_G1_NC:
8363     case elfcpp::R_ARM_ALU_SB_G1:
8364     case elfcpp::R_ARM_ALU_SB_G2:
8365     case elfcpp::R_ARM_LDR_SB_G0:
8366     case elfcpp::R_ARM_LDR_SB_G1:
8367     case elfcpp::R_ARM_LDR_SB_G2:
8368     case elfcpp::R_ARM_LDRS_SB_G0:
8369     case elfcpp::R_ARM_LDRS_SB_G1:
8370     case elfcpp::R_ARM_LDRS_SB_G2:
8371     case elfcpp::R_ARM_LDC_SB_G0:
8372     case elfcpp::R_ARM_LDC_SB_G1:
8373     case elfcpp::R_ARM_LDC_SB_G2:
8374     case elfcpp::R_ARM_MOVW_BREL_NC:
8375     case elfcpp::R_ARM_MOVT_BREL:
8376     case elfcpp::R_ARM_MOVW_BREL:
8377     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8378     case elfcpp::R_ARM_THM_MOVT_BREL:
8379     case elfcpp::R_ARM_THM_MOVW_BREL:
8380       // Relative addressing relocations.
8381       {
8382         // Make a dynamic relocation if necessary.
8383         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8384           {
8385             if (target->may_need_copy_reloc(gsym))
8386               {
8387                 target->copy_reloc(symtab, layout, object,
8388                                    data_shndx, output_section, gsym, reloc);
8389               }
8390             else
8391               {
8392                 check_non_pic(object, r_type);
8393                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8394                 rel_dyn->add_global(gsym, r_type, output_section, object,
8395                                     data_shndx, reloc.get_r_offset());
8396               }
8397           }
8398       }
8399       break;
8400
8401     case elfcpp::R_ARM_THM_CALL:
8402     case elfcpp::R_ARM_PLT32:
8403     case elfcpp::R_ARM_CALL:
8404     case elfcpp::R_ARM_JUMP24:
8405     case elfcpp::R_ARM_THM_JUMP24:
8406     case elfcpp::R_ARM_SBREL31:
8407     case elfcpp::R_ARM_PREL31:
8408     case elfcpp::R_ARM_THM_JUMP19:
8409     case elfcpp::R_ARM_THM_JUMP6:
8410     case elfcpp::R_ARM_THM_JUMP11:
8411     case elfcpp::R_ARM_THM_JUMP8:
8412       // All the relocation above are branches except for the PREL31 ones.
8413       // A PREL31 relocation can point to a personality function in a shared
8414       // library.  In that case we want to use a PLT because we want to
8415       // call the personality routine and the dynamic linkers we care about
8416       // do not support dynamic PREL31 relocations. An REL31 relocation may
8417       // point to a function whose unwinding behaviour is being described but
8418       // we will not mistakenly generate a PLT for that because we should use
8419       // a local section symbol.
8420
8421       // If the symbol is fully resolved, this is just a relative
8422       // local reloc.  Otherwise we need a PLT entry.
8423       if (gsym->final_value_is_known())
8424         break;
8425       // If building a shared library, we can also skip the PLT entry
8426       // if the symbol is defined in the output file and is protected
8427       // or hidden.
8428       if (gsym->is_defined()
8429           && !gsym->is_from_dynobj()
8430           && !gsym->is_preemptible())
8431         break;
8432       target->make_plt_entry(symtab, layout, gsym);
8433       break;
8434
8435     case elfcpp::R_ARM_GOT_BREL:
8436     case elfcpp::R_ARM_GOT_ABS:
8437     case elfcpp::R_ARM_GOT_PREL:
8438       {
8439         // The symbol requires a GOT entry.
8440         Arm_output_data_got<big_endian>* got =
8441           target->got_section(symtab, layout);
8442         if (gsym->final_value_is_known())
8443           got->add_global(gsym, GOT_TYPE_STANDARD);
8444         else
8445           {
8446             // If this symbol is not fully resolved, we need to add a
8447             // GOT entry with a dynamic relocation.
8448             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8449             if (gsym->is_from_dynobj()
8450                 || gsym->is_undefined()
8451                 || gsym->is_preemptible()
8452                 || (gsym->visibility() == elfcpp::STV_PROTECTED
8453                     && parameters->options().shared()))
8454               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8455                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8456             else
8457               {
8458                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8459                   rel_dyn->add_global_relative(
8460                       gsym, elfcpp::R_ARM_RELATIVE, got,
8461                       gsym->got_offset(GOT_TYPE_STANDARD));
8462               }
8463           }
8464       }
8465       break;
8466
8467     case elfcpp::R_ARM_TARGET1:
8468     case elfcpp::R_ARM_TARGET2:
8469       // These should have been mapped to other types already.
8470       // Fall through.
8471     case elfcpp::R_ARM_COPY:
8472     case elfcpp::R_ARM_GLOB_DAT:
8473     case elfcpp::R_ARM_JUMP_SLOT:
8474     case elfcpp::R_ARM_RELATIVE:
8475       // These are relocations which should only be seen by the
8476       // dynamic linker, and should never be seen here.
8477       gold_error(_("%s: unexpected reloc %u in object file"),
8478                  object->name().c_str(), r_type);
8479       break;
8480
8481       // These are initial tls relocs, which are expected when
8482       // linking.
8483     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8484     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8485     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8486     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8487     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8488       {
8489         const bool is_final = gsym->final_value_is_known();
8490         const tls::Tls_optimization optimized_type
8491             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8492         switch (r_type)
8493           {
8494           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8495             if (optimized_type == tls::TLSOPT_NONE)
8496               {
8497                 // Create a pair of GOT entries for the module index and
8498                 // dtv-relative offset.
8499                 Arm_output_data_got<big_endian>* got
8500                     = target->got_section(symtab, layout);
8501                 if (!parameters->doing_static_link())
8502                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8503                                                 target->rel_dyn_section(layout),
8504                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8505                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8506                 else
8507                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8508               }
8509             else
8510               // FIXME: TLS optimization not supported yet.
8511               gold_unreachable();
8512             break;
8513
8514           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8515             if (optimized_type == tls::TLSOPT_NONE)
8516               {
8517                 // Create a GOT entry for the module index.
8518                 target->got_mod_index_entry(symtab, layout, object);
8519               }
8520             else
8521               // FIXME: TLS optimization not supported yet.
8522               gold_unreachable();
8523             break;
8524
8525           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8526             break;
8527
8528           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8529             layout->set_has_static_tls();
8530             if (optimized_type == tls::TLSOPT_NONE)
8531               {
8532                 // Create a GOT entry for the tp-relative offset.
8533                 Arm_output_data_got<big_endian>* got
8534                   = target->got_section(symtab, layout);
8535                 if (!parameters->doing_static_link())
8536                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8537                                            target->rel_dyn_section(layout),
8538                                            elfcpp::R_ARM_TLS_TPOFF32);
8539                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8540                   {
8541                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8542                     unsigned int got_offset =
8543                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8544                     got->add_static_reloc(got_offset,
8545                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
8546                   }
8547               }
8548             else
8549               // FIXME: TLS optimization not supported yet.
8550               gold_unreachable();
8551             break;
8552
8553           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
8554             layout->set_has_static_tls();
8555             if (parameters->options().shared())
8556               {
8557                 // We need to create a dynamic relocation.
8558                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8559                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8560                                     output_section, object,
8561                                     data_shndx, reloc.get_r_offset());
8562               }
8563             break;
8564
8565           default:
8566             gold_unreachable();
8567           }
8568       }
8569       break;
8570
8571     case elfcpp::R_ARM_PC24:
8572     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8573     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8574     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8575     default:
8576       unsupported_reloc_global(object, r_type, gsym);
8577       break;
8578     }
8579 }
8580
8581 // Process relocations for gc.
8582
8583 template<bool big_endian>
8584 void
8585 Target_arm<big_endian>::gc_process_relocs(
8586     Symbol_table* symtab,
8587     Layout* layout,
8588     Sized_relobj_file<32, big_endian>* object,
8589     unsigned int data_shndx,
8590     unsigned int,
8591     const unsigned char* prelocs,
8592     size_t reloc_count,
8593     Output_section* output_section,
8594     bool needs_special_offset_handling,
8595     size_t local_symbol_count,
8596     const unsigned char* plocal_symbols)
8597 {
8598   typedef Target_arm<big_endian> Arm;
8599   typedef typename Target_arm<big_endian>::Scan Scan;
8600
8601   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8602                           typename Target_arm::Relocatable_size_for_reloc>(
8603     symtab,
8604     layout,
8605     this,
8606     object,
8607     data_shndx,
8608     prelocs,
8609     reloc_count,
8610     output_section,
8611     needs_special_offset_handling,
8612     local_symbol_count,
8613     plocal_symbols);
8614 }
8615
8616 // Scan relocations for a section.
8617
8618 template<bool big_endian>
8619 void
8620 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8621                                     Layout* layout,
8622                                     Sized_relobj_file<32, big_endian>* object,
8623                                     unsigned int data_shndx,
8624                                     unsigned int sh_type,
8625                                     const unsigned char* prelocs,
8626                                     size_t reloc_count,
8627                                     Output_section* output_section,
8628                                     bool needs_special_offset_handling,
8629                                     size_t local_symbol_count,
8630                                     const unsigned char* plocal_symbols)
8631 {
8632   typedef typename Target_arm<big_endian>::Scan Scan;
8633   if (sh_type == elfcpp::SHT_RELA)
8634     {
8635       gold_error(_("%s: unsupported RELA reloc section"),
8636                  object->name().c_str());
8637       return;
8638     }
8639
8640   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8641     symtab,
8642     layout,
8643     this,
8644     object,
8645     data_shndx,
8646     prelocs,
8647     reloc_count,
8648     output_section,
8649     needs_special_offset_handling,
8650     local_symbol_count,
8651     plocal_symbols);
8652 }
8653
8654 // Finalize the sections.
8655
8656 template<bool big_endian>
8657 void
8658 Target_arm<big_endian>::do_finalize_sections(
8659     Layout* layout,
8660     const Input_objects* input_objects,
8661     Symbol_table*)
8662 {
8663   bool merged_any_attributes = false;
8664   // Merge processor-specific flags.
8665   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8666        p != input_objects->relobj_end();
8667        ++p)
8668     {
8669       Arm_relobj<big_endian>* arm_relobj =
8670         Arm_relobj<big_endian>::as_arm_relobj(*p);
8671       if (arm_relobj->merge_flags_and_attributes())
8672         {
8673           this->merge_processor_specific_flags(
8674               arm_relobj->name(),
8675               arm_relobj->processor_specific_flags());
8676           this->merge_object_attributes(arm_relobj->name().c_str(),
8677                                         arm_relobj->attributes_section_data());
8678           merged_any_attributes = true;
8679         }
8680     }
8681
8682   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8683        p != input_objects->dynobj_end();
8684        ++p)
8685     {
8686       Arm_dynobj<big_endian>* arm_dynobj =
8687         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8688       this->merge_processor_specific_flags(
8689           arm_dynobj->name(),
8690           arm_dynobj->processor_specific_flags());
8691       this->merge_object_attributes(arm_dynobj->name().c_str(),
8692                                     arm_dynobj->attributes_section_data());
8693       merged_any_attributes = true;
8694     }
8695
8696   // Create an empty uninitialized attribute section if we still don't have it
8697   // at this moment.  This happens if there is no attributes sections in all
8698   // inputs.
8699   if (this->attributes_section_data_ == NULL)
8700     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8701
8702   const Object_attribute* cpu_arch_attr =
8703     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8704   // Check if we need to use Cortex-A8 workaround.
8705   if (parameters->options().user_set_fix_cortex_a8())
8706     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8707   else
8708     {
8709       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8710       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8711       // profile.
8712       const Object_attribute* cpu_arch_profile_attr =
8713         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8714       this->fix_cortex_a8_ =
8715         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8716          && (cpu_arch_profile_attr->int_value() == 'A'
8717              || cpu_arch_profile_attr->int_value() == 0));
8718     }
8719
8720   // Check if we can use V4BX interworking.
8721   // The V4BX interworking stub contains BX instruction,
8722   // which is not specified for some profiles.
8723   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8724       && !this->may_use_v4t_interworking())
8725     gold_error(_("unable to provide V4BX reloc interworking fix up; "
8726                  "the target profile does not support BX instruction"));
8727
8728   // Fill in some more dynamic tags.
8729   const Reloc_section* rel_plt = (this->plt_ == NULL
8730                                   ? NULL
8731                                   : this->plt_->rel_plt());
8732   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8733                                   this->rel_dyn_, true, false);
8734
8735   // Emit any relocs we saved in an attempt to avoid generating COPY
8736   // relocs.
8737   if (this->copy_relocs_.any_saved_relocs())
8738     this->copy_relocs_.emit(this->rel_dyn_section(layout));
8739
8740   // Handle the .ARM.exidx section.
8741   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8742
8743   if (!parameters->options().relocatable())
8744     {
8745       if (exidx_section != NULL
8746           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8747         {
8748           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8749           // the .ARM.exidx section.
8750           if (!layout->script_options()->saw_phdrs_clause())
8751             {
8752               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8753                                                       0)
8754                           == NULL);
8755               Output_segment*  exidx_segment =
8756                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8757               exidx_segment->add_output_section_to_nonload(exidx_section,
8758                                                            elfcpp::PF_R);
8759             }
8760         }
8761     }
8762
8763   // Create an .ARM.attributes section if we have merged any attributes
8764   // from inputs.
8765   if (merged_any_attributes)
8766     {
8767       Output_attributes_section_data* attributes_section =
8768       new Output_attributes_section_data(*this->attributes_section_data_);
8769       layout->add_output_section_data(".ARM.attributes",
8770                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
8771                                       attributes_section, ORDER_INVALID,
8772                                       false);
8773     }
8774
8775   // Fix up links in section EXIDX headers.
8776   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8777        p != layout->section_list().end();
8778        ++p)
8779     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8780       {
8781         Arm_output_section<big_endian>* os =
8782           Arm_output_section<big_endian>::as_arm_output_section(*p);
8783         os->set_exidx_section_link();
8784       }
8785 }
8786
8787 // Return whether a direct absolute static relocation needs to be applied.
8788 // In cases where Scan::local() or Scan::global() has created
8789 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8790 // of the relocation is carried in the data, and we must not
8791 // apply the static relocation.
8792
8793 template<bool big_endian>
8794 inline bool
8795 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8796     const Sized_symbol<32>* gsym,
8797     unsigned int r_type,
8798     bool is_32bit,
8799     Output_section* output_section)
8800 {
8801   // If the output section is not allocated, then we didn't call
8802   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8803   // the reloc here.
8804   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8805       return true;
8806
8807   int ref_flags = Scan::get_reference_flags(r_type);
8808
8809   // For local symbols, we will have created a non-RELATIVE dynamic
8810   // relocation only if (a) the output is position independent,
8811   // (b) the relocation is absolute (not pc- or segment-relative), and
8812   // (c) the relocation is not 32 bits wide.
8813   if (gsym == NULL)
8814     return !(parameters->options().output_is_position_independent()
8815              && (ref_flags & Symbol::ABSOLUTE_REF)
8816              && !is_32bit);
8817
8818   // For global symbols, we use the same helper routines used in the
8819   // scan pass.  If we did not create a dynamic relocation, or if we
8820   // created a RELATIVE dynamic relocation, we should apply the static
8821   // relocation.
8822   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8823   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8824                  && gsym->can_use_relative_reloc(ref_flags
8825                                                  & Symbol::FUNCTION_CALL);
8826   return !has_dyn || is_rel;
8827 }
8828
8829 // Perform a relocation.
8830
8831 template<bool big_endian>
8832 inline bool
8833 Target_arm<big_endian>::Relocate::relocate(
8834     const Relocate_info<32, big_endian>* relinfo,
8835     Target_arm* target,
8836     Output_section* output_section,
8837     size_t relnum,
8838     const elfcpp::Rel<32, big_endian>& rel,
8839     unsigned int r_type,
8840     const Sized_symbol<32>* gsym,
8841     const Symbol_value<32>* psymval,
8842     unsigned char* view,
8843     Arm_address address,
8844     section_size_type view_size)
8845 {
8846   if (view == NULL)
8847     return true;
8848
8849   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8850
8851   r_type = get_real_reloc_type(r_type);
8852   const Arm_reloc_property* reloc_property =
8853     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8854   if (reloc_property == NULL)
8855     {
8856       std::string reloc_name =
8857         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8858       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8859                              _("cannot relocate %s in object file"),
8860                              reloc_name.c_str());
8861       return true;
8862     }
8863
8864   const Arm_relobj<big_endian>* object =
8865     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8866
8867   // If the final branch target of a relocation is THUMB instruction, this
8868   // is 1.  Otherwise it is 0.
8869   Arm_address thumb_bit = 0;
8870   Symbol_value<32> symval;
8871   bool is_weakly_undefined_without_plt = false;
8872   bool have_got_offset = false;
8873   unsigned int got_offset = 0;
8874
8875   // If the relocation uses the GOT entry of a symbol instead of the symbol
8876   // itself, we don't care about whether the symbol is defined or what kind
8877   // of symbol it is.
8878   if (reloc_property->uses_got_entry())
8879     {
8880       // Get the GOT offset.
8881       // The GOT pointer points to the end of the GOT section.
8882       // We need to subtract the size of the GOT section to get
8883       // the actual offset to use in the relocation.
8884       // TODO: We should move GOT offset computing code in TLS relocations
8885       // to here.
8886       switch (r_type)
8887         {
8888         case elfcpp::R_ARM_GOT_BREL:
8889         case elfcpp::R_ARM_GOT_PREL:
8890           if (gsym != NULL)
8891             {
8892               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8893               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8894                             - target->got_size());
8895             }
8896           else
8897             {
8898               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8899               gold_assert(object->local_has_got_offset(r_sym,
8900                                                        GOT_TYPE_STANDARD));
8901               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8902                             - target->got_size());
8903             }
8904           have_got_offset = true;
8905           break;
8906
8907         default:
8908           break;
8909         }
8910     }
8911   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8912     {
8913       if (gsym != NULL)
8914         {
8915           // This is a global symbol.  Determine if we use PLT and if the
8916           // final target is THUMB.
8917           if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8918             {
8919               // This uses a PLT, change the symbol value.
8920               symval.set_output_value(target->plt_section()->address()
8921                                       + gsym->plt_offset());
8922               psymval = &symval;
8923             }
8924           else if (gsym->is_weak_undefined())
8925             {
8926               // This is a weakly undefined symbol and we do not use PLT
8927               // for this relocation.  A branch targeting this symbol will
8928               // be converted into an NOP.
8929               is_weakly_undefined_without_plt = true;
8930             }
8931           else if (gsym->is_undefined() && reloc_property->uses_symbol())
8932             {
8933               // This relocation uses the symbol value but the symbol is
8934               // undefined.  Exit early and have the caller reporting an
8935               // error.
8936               return true;
8937             }
8938           else
8939             {
8940               // Set thumb bit if symbol:
8941               // -Has type STT_ARM_TFUNC or
8942               // -Has type STT_FUNC, is defined and with LSB in value set.
8943               thumb_bit =
8944                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8945                  || (gsym->type() == elfcpp::STT_FUNC
8946                      && !gsym->is_undefined()
8947                      && ((psymval->value(object, 0) & 1) != 0)))
8948                 ? 1
8949                 : 0);
8950             }
8951         }
8952       else
8953         {
8954           // This is a local symbol.  Determine if the final target is THUMB.
8955           // We saved this information when all the local symbols were read.
8956           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8957           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8958           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8959         }
8960     }
8961   else
8962     {
8963       // This is a fake relocation synthesized for a stub.  It does not have
8964       // a real symbol.  We just look at the LSB of the symbol value to
8965       // determine if the target is THUMB or not.
8966       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8967     }
8968
8969   // Strip LSB if this points to a THUMB target.
8970   if (thumb_bit != 0
8971       && reloc_property->uses_thumb_bit()
8972       && ((psymval->value(object, 0) & 1) != 0))
8973     {
8974       Arm_address stripped_value =
8975         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8976       symval.set_output_value(stripped_value);
8977       psymval = &symval;
8978     }
8979
8980   // To look up relocation stubs, we need to pass the symbol table index of
8981   // a local symbol.
8982   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8983
8984   // Get the addressing origin of the output segment defining the
8985   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8986   Arm_address sym_origin = 0;
8987   if (reloc_property->uses_symbol_base())
8988     {
8989       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8990         // R_ARM_BASE_ABS with the NULL symbol will give the
8991         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8992         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8993         sym_origin = target->got_plt_section()->address();
8994       else if (gsym == NULL)
8995         sym_origin = 0;
8996       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8997         sym_origin = gsym->output_segment()->vaddr();
8998       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8999         sym_origin = gsym->output_data()->address();
9000
9001       // TODO: Assumes the segment base to be zero for the global symbols
9002       // till the proper support for the segment-base-relative addressing
9003       // will be implemented.  This is consistent with GNU ld.
9004     }
9005
9006   // For relative addressing relocation, find out the relative address base.
9007   Arm_address relative_address_base = 0;
9008   switch(reloc_property->relative_address_base())
9009     {
9010     case Arm_reloc_property::RAB_NONE:
9011     // Relocations with relative address bases RAB_TLS and RAB_tp are
9012     // handled by relocate_tls.  So we do not need to do anything here.
9013     case Arm_reloc_property::RAB_TLS:
9014     case Arm_reloc_property::RAB_tp:
9015       break;
9016     case Arm_reloc_property::RAB_B_S:
9017       relative_address_base = sym_origin;
9018       break;
9019     case Arm_reloc_property::RAB_GOT_ORG:
9020       relative_address_base = target->got_plt_section()->address();
9021       break;
9022     case Arm_reloc_property::RAB_P:
9023       relative_address_base = address;
9024       break;
9025     case Arm_reloc_property::RAB_Pa:
9026       relative_address_base = address & 0xfffffffcU;
9027       break;
9028     default:
9029       gold_unreachable();
9030     }
9031
9032   typename Arm_relocate_functions::Status reloc_status =
9033         Arm_relocate_functions::STATUS_OKAY;
9034   bool check_overflow = reloc_property->checks_overflow();
9035   switch (r_type)
9036     {
9037     case elfcpp::R_ARM_NONE:
9038       break;
9039
9040     case elfcpp::R_ARM_ABS8:
9041       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9042         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9043       break;
9044
9045     case elfcpp::R_ARM_ABS12:
9046       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9047         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9048       break;
9049
9050     case elfcpp::R_ARM_ABS16:
9051       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9052         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9053       break;
9054
9055     case elfcpp::R_ARM_ABS32:
9056       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9057         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9058                                                      thumb_bit);
9059       break;
9060
9061     case elfcpp::R_ARM_ABS32_NOI:
9062       if (should_apply_static_reloc(gsym, r_type, true, output_section))
9063         // No thumb bit for this relocation: (S + A)
9064         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9065                                                      0);
9066       break;
9067
9068     case elfcpp::R_ARM_MOVW_ABS_NC:
9069       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9070         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9071                                                     0, thumb_bit,
9072                                                     check_overflow);
9073       break;
9074
9075     case elfcpp::R_ARM_MOVT_ABS:
9076       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9077         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9078       break;
9079
9080     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9081       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9082         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9083                                                         0, thumb_bit, false);
9084       break;
9085
9086     case elfcpp::R_ARM_THM_MOVT_ABS:
9087       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9088         reloc_status = Arm_relocate_functions::thm_movt(view, object,
9089                                                         psymval, 0);
9090       break;
9091
9092     case elfcpp::R_ARM_MOVW_PREL_NC:
9093     case elfcpp::R_ARM_MOVW_BREL_NC:
9094     case elfcpp::R_ARM_MOVW_BREL:
9095       reloc_status =
9096         Arm_relocate_functions::movw(view, object, psymval,
9097                                      relative_address_base, thumb_bit,
9098                                      check_overflow);
9099       break;
9100
9101     case elfcpp::R_ARM_MOVT_PREL:
9102     case elfcpp::R_ARM_MOVT_BREL:
9103       reloc_status =
9104         Arm_relocate_functions::movt(view, object, psymval,
9105                                      relative_address_base);
9106       break;
9107
9108     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9109     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9110     case elfcpp::R_ARM_THM_MOVW_BREL:
9111       reloc_status =
9112         Arm_relocate_functions::thm_movw(view, object, psymval,
9113                                          relative_address_base,
9114                                          thumb_bit, check_overflow);
9115       break;
9116
9117     case elfcpp::R_ARM_THM_MOVT_PREL:
9118     case elfcpp::R_ARM_THM_MOVT_BREL:
9119       reloc_status =
9120         Arm_relocate_functions::thm_movt(view, object, psymval,
9121                                          relative_address_base);
9122       break;
9123
9124     case elfcpp::R_ARM_REL32:
9125       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9126                                                    address, thumb_bit);
9127       break;
9128
9129     case elfcpp::R_ARM_THM_ABS5:
9130       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9131         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9132       break;
9133
9134     // Thumb long branches.
9135     case elfcpp::R_ARM_THM_CALL:
9136     case elfcpp::R_ARM_THM_XPC22:
9137     case elfcpp::R_ARM_THM_JUMP24:
9138       reloc_status =
9139         Arm_relocate_functions::thumb_branch_common(
9140             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9141             thumb_bit, is_weakly_undefined_without_plt);
9142       break;
9143
9144     case elfcpp::R_ARM_GOTOFF32:
9145       {
9146         Arm_address got_origin;
9147         got_origin = target->got_plt_section()->address();
9148         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9149                                                      got_origin, thumb_bit);
9150       }
9151       break;
9152
9153     case elfcpp::R_ARM_BASE_PREL:
9154       gold_assert(gsym != NULL);
9155       reloc_status =
9156           Arm_relocate_functions::base_prel(view, sym_origin, address);
9157       break;
9158
9159     case elfcpp::R_ARM_BASE_ABS:
9160       if (should_apply_static_reloc(gsym, r_type, false, output_section))
9161         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9162       break;
9163
9164     case elfcpp::R_ARM_GOT_BREL:
9165       gold_assert(have_got_offset);
9166       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9167       break;
9168
9169     case elfcpp::R_ARM_GOT_PREL:
9170       gold_assert(have_got_offset);
9171       // Get the address origin for GOT PLT, which is allocated right
9172       // after the GOT section, to calculate an absolute address of
9173       // the symbol GOT entry (got_origin + got_offset).
9174       Arm_address got_origin;
9175       got_origin = target->got_plt_section()->address();
9176       reloc_status = Arm_relocate_functions::got_prel(view,
9177                                                       got_origin + got_offset,
9178                                                       address);
9179       break;
9180
9181     case elfcpp::R_ARM_PLT32:
9182     case elfcpp::R_ARM_CALL:
9183     case elfcpp::R_ARM_JUMP24:
9184     case elfcpp::R_ARM_XPC25:
9185       gold_assert(gsym == NULL
9186                   || gsym->has_plt_offset()
9187                   || gsym->final_value_is_known()
9188                   || (gsym->is_defined()
9189                       && !gsym->is_from_dynobj()
9190                       && !gsym->is_preemptible()));
9191       reloc_status =
9192         Arm_relocate_functions::arm_branch_common(
9193             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9194             thumb_bit, is_weakly_undefined_without_plt);
9195       break;
9196
9197     case elfcpp::R_ARM_THM_JUMP19:
9198       reloc_status =
9199         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9200                                            thumb_bit);
9201       break;
9202
9203     case elfcpp::R_ARM_THM_JUMP6:
9204       reloc_status =
9205         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9206       break;
9207
9208     case elfcpp::R_ARM_THM_JUMP8:
9209       reloc_status =
9210         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9211       break;
9212
9213     case elfcpp::R_ARM_THM_JUMP11:
9214       reloc_status =
9215         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9216       break;
9217
9218     case elfcpp::R_ARM_PREL31:
9219       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9220                                                     address, thumb_bit);
9221       break;
9222
9223     case elfcpp::R_ARM_V4BX:
9224       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9225         {
9226           const bool is_v4bx_interworking =
9227               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9228           reloc_status =
9229             Arm_relocate_functions::v4bx(relinfo, view, object, address,
9230                                          is_v4bx_interworking);
9231         }
9232       break;
9233
9234     case elfcpp::R_ARM_THM_PC8:
9235       reloc_status =
9236         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9237       break;
9238
9239     case elfcpp::R_ARM_THM_PC12:
9240       reloc_status =
9241         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9242       break;
9243
9244     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9245       reloc_status =
9246         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9247                                           thumb_bit);
9248       break;
9249
9250     case elfcpp::R_ARM_ALU_PC_G0_NC:
9251     case elfcpp::R_ARM_ALU_PC_G0:
9252     case elfcpp::R_ARM_ALU_PC_G1_NC:
9253     case elfcpp::R_ARM_ALU_PC_G1:
9254     case elfcpp::R_ARM_ALU_PC_G2:
9255     case elfcpp::R_ARM_ALU_SB_G0_NC:
9256     case elfcpp::R_ARM_ALU_SB_G0:
9257     case elfcpp::R_ARM_ALU_SB_G1_NC:
9258     case elfcpp::R_ARM_ALU_SB_G1:
9259     case elfcpp::R_ARM_ALU_SB_G2:
9260       reloc_status =
9261         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9262                                             reloc_property->group_index(),
9263                                             relative_address_base,
9264                                             thumb_bit, check_overflow);
9265       break;
9266
9267     case elfcpp::R_ARM_LDR_PC_G0:
9268     case elfcpp::R_ARM_LDR_PC_G1:
9269     case elfcpp::R_ARM_LDR_PC_G2:
9270     case elfcpp::R_ARM_LDR_SB_G0:
9271     case elfcpp::R_ARM_LDR_SB_G1:
9272     case elfcpp::R_ARM_LDR_SB_G2:
9273       reloc_status =
9274           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9275                                               reloc_property->group_index(),
9276                                               relative_address_base);
9277       break;
9278
9279     case elfcpp::R_ARM_LDRS_PC_G0:
9280     case elfcpp::R_ARM_LDRS_PC_G1:
9281     case elfcpp::R_ARM_LDRS_PC_G2:
9282     case elfcpp::R_ARM_LDRS_SB_G0:
9283     case elfcpp::R_ARM_LDRS_SB_G1:
9284     case elfcpp::R_ARM_LDRS_SB_G2:
9285       reloc_status =
9286           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9287                                                reloc_property->group_index(),
9288                                                relative_address_base);
9289       break;
9290
9291     case elfcpp::R_ARM_LDC_PC_G0:
9292     case elfcpp::R_ARM_LDC_PC_G1:
9293     case elfcpp::R_ARM_LDC_PC_G2:
9294     case elfcpp::R_ARM_LDC_SB_G0:
9295     case elfcpp::R_ARM_LDC_SB_G1:
9296     case elfcpp::R_ARM_LDC_SB_G2:
9297       reloc_status =
9298           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9299                                               reloc_property->group_index(),
9300                                               relative_address_base);
9301       break;
9302
9303       // These are initial tls relocs, which are expected when
9304       // linking.
9305     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9306     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9307     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9308     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9309     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9310       reloc_status =
9311         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9312                            view, address, view_size);
9313       break;
9314
9315     // The known and unknown unsupported and/or deprecated relocations.
9316     case elfcpp::R_ARM_PC24:
9317     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9318     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9319     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9320     default:
9321       // Just silently leave the method. We should get an appropriate error
9322       // message in the scan methods.
9323       break;
9324     }
9325
9326   // Report any errors.
9327   switch (reloc_status)
9328     {
9329     case Arm_relocate_functions::STATUS_OKAY:
9330       break;
9331     case Arm_relocate_functions::STATUS_OVERFLOW:
9332       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9333                              _("relocation overflow in %s"),
9334                              reloc_property->name().c_str());
9335       break;
9336     case Arm_relocate_functions::STATUS_BAD_RELOC:
9337       gold_error_at_location(
9338         relinfo,
9339         relnum,
9340         rel.get_r_offset(),
9341         _("unexpected opcode while processing relocation %s"),
9342         reloc_property->name().c_str());
9343       break;
9344     default:
9345       gold_unreachable();
9346     }
9347
9348   return true;
9349 }
9350
9351 // Perform a TLS relocation.
9352
9353 template<bool big_endian>
9354 inline typename Arm_relocate_functions<big_endian>::Status
9355 Target_arm<big_endian>::Relocate::relocate_tls(
9356     const Relocate_info<32, big_endian>* relinfo,
9357     Target_arm<big_endian>* target,
9358     size_t relnum,
9359     const elfcpp::Rel<32, big_endian>& rel,
9360     unsigned int r_type,
9361     const Sized_symbol<32>* gsym,
9362     const Symbol_value<32>* psymval,
9363     unsigned char* view,
9364     elfcpp::Elf_types<32>::Elf_Addr address,
9365     section_size_type /*view_size*/ )
9366 {
9367   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9368   typedef Relocate_functions<32, big_endian> RelocFuncs;
9369   Output_segment* tls_segment = relinfo->layout->tls_segment();
9370
9371   const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9372
9373   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9374
9375   const bool is_final = (gsym == NULL
9376                          ? !parameters->options().shared()
9377                          : gsym->final_value_is_known());
9378   const tls::Tls_optimization optimized_type
9379       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9380   switch (r_type)
9381     {
9382     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9383         {
9384           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9385           unsigned int got_offset;
9386           if (gsym != NULL)
9387             {
9388               gold_assert(gsym->has_got_offset(got_type));
9389               got_offset = gsym->got_offset(got_type) - target->got_size();
9390             }
9391           else
9392             {
9393               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9394               gold_assert(object->local_has_got_offset(r_sym, got_type));
9395               got_offset = (object->local_got_offset(r_sym, got_type)
9396                             - target->got_size());
9397             }
9398           if (optimized_type == tls::TLSOPT_NONE)
9399             {
9400               Arm_address got_entry =
9401                 target->got_plt_section()->address() + got_offset;
9402
9403               // Relocate the field with the PC relative offset of the pair of
9404               // GOT entries.
9405               RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9406               return ArmRelocFuncs::STATUS_OKAY;
9407             }
9408         }
9409       break;
9410
9411     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9412       if (optimized_type == tls::TLSOPT_NONE)
9413         {
9414           // Relocate the field with the offset of the GOT entry for
9415           // the module index.
9416           unsigned int got_offset;
9417           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9418                         - target->got_size());
9419           Arm_address got_entry =
9420             target->got_plt_section()->address() + got_offset;
9421
9422           // Relocate the field with the PC relative offset of the pair of
9423           // GOT entries.
9424           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9425           return ArmRelocFuncs::STATUS_OKAY;
9426         }
9427       break;
9428
9429     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9430       RelocFuncs::rel32_unaligned(view, value);
9431       return ArmRelocFuncs::STATUS_OKAY;
9432
9433     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9434       if (optimized_type == tls::TLSOPT_NONE)
9435         {
9436           // Relocate the field with the offset of the GOT entry for
9437           // the tp-relative offset of the symbol.
9438           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9439           unsigned int got_offset;
9440           if (gsym != NULL)
9441             {
9442               gold_assert(gsym->has_got_offset(got_type));
9443               got_offset = gsym->got_offset(got_type);
9444             }
9445           else
9446             {
9447               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9448               gold_assert(object->local_has_got_offset(r_sym, got_type));
9449               got_offset = object->local_got_offset(r_sym, got_type);
9450             }
9451
9452           // All GOT offsets are relative to the end of the GOT.
9453           got_offset -= target->got_size();
9454
9455           Arm_address got_entry =
9456             target->got_plt_section()->address() + got_offset;
9457
9458           // Relocate the field with the PC relative offset of the GOT entry.
9459           RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9460           return ArmRelocFuncs::STATUS_OKAY;
9461         }
9462       break;
9463
9464     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9465       // If we're creating a shared library, a dynamic relocation will
9466       // have been created for this location, so do not apply it now.
9467       if (!parameters->options().shared())
9468         {
9469           gold_assert(tls_segment != NULL);
9470
9471           // $tp points to the TCB, which is followed by the TLS, so we
9472           // need to add TCB size to the offset.
9473           Arm_address aligned_tcb_size =
9474             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9475           RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9476
9477         }
9478       return ArmRelocFuncs::STATUS_OKAY;
9479
9480     default:
9481       gold_unreachable();
9482     }
9483
9484   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9485                          _("unsupported reloc %u"),
9486                          r_type);
9487   return ArmRelocFuncs::STATUS_BAD_RELOC;
9488 }
9489
9490 // Relocate section data.
9491
9492 template<bool big_endian>
9493 void
9494 Target_arm<big_endian>::relocate_section(
9495     const Relocate_info<32, big_endian>* relinfo,
9496     unsigned int sh_type,
9497     const unsigned char* prelocs,
9498     size_t reloc_count,
9499     Output_section* output_section,
9500     bool needs_special_offset_handling,
9501     unsigned char* view,
9502     Arm_address address,
9503     section_size_type view_size,
9504     const Reloc_symbol_changes* reloc_symbol_changes)
9505 {
9506   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9507   gold_assert(sh_type == elfcpp::SHT_REL);
9508
9509   // See if we are relocating a relaxed input section.  If so, the view
9510   // covers the whole output section and we need to adjust accordingly.
9511   if (needs_special_offset_handling)
9512     {
9513       const Output_relaxed_input_section* poris =
9514         output_section->find_relaxed_input_section(relinfo->object,
9515                                                    relinfo->data_shndx);
9516       if (poris != NULL)
9517         {
9518           Arm_address section_address = poris->address();
9519           section_size_type section_size = poris->data_size();
9520
9521           gold_assert((section_address >= address)
9522                       && ((section_address + section_size)
9523                           <= (address + view_size)));
9524
9525           off_t offset = section_address - address;
9526           view += offset;
9527           address += offset;
9528           view_size = section_size;
9529         }
9530     }
9531
9532   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9533                          Arm_relocate, gold::Default_comdat_behavior>(
9534     relinfo,
9535     this,
9536     prelocs,
9537     reloc_count,
9538     output_section,
9539     needs_special_offset_handling,
9540     view,
9541     address,
9542     view_size,
9543     reloc_symbol_changes);
9544 }
9545
9546 // Return the size of a relocation while scanning during a relocatable
9547 // link.
9548
9549 template<bool big_endian>
9550 unsigned int
9551 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9552     unsigned int r_type,
9553     Relobj* object)
9554 {
9555   r_type = get_real_reloc_type(r_type);
9556   const Arm_reloc_property* arp =
9557       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9558   if (arp != NULL)
9559     return arp->size();
9560   else
9561     {
9562       std::string reloc_name =
9563         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9564       gold_error(_("%s: unexpected %s in object file"),
9565                  object->name().c_str(), reloc_name.c_str());
9566       return 0;
9567     }
9568 }
9569
9570 // Scan the relocs during a relocatable link.
9571
9572 template<bool big_endian>
9573 void
9574 Target_arm<big_endian>::scan_relocatable_relocs(
9575     Symbol_table* symtab,
9576     Layout* layout,
9577     Sized_relobj_file<32, big_endian>* object,
9578     unsigned int data_shndx,
9579     unsigned int sh_type,
9580     const unsigned char* prelocs,
9581     size_t reloc_count,
9582     Output_section* output_section,
9583     bool needs_special_offset_handling,
9584     size_t local_symbol_count,
9585     const unsigned char* plocal_symbols,
9586     Relocatable_relocs* rr)
9587 {
9588   gold_assert(sh_type == elfcpp::SHT_REL);
9589
9590   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9591     Relocatable_size_for_reloc> Scan_relocatable_relocs;
9592
9593   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9594       Scan_relocatable_relocs>(
9595     symtab,
9596     layout,
9597     object,
9598     data_shndx,
9599     prelocs,
9600     reloc_count,
9601     output_section,
9602     needs_special_offset_handling,
9603     local_symbol_count,
9604     plocal_symbols,
9605     rr);
9606 }
9607
9608 // Emit relocations for a section.
9609
9610 template<bool big_endian>
9611 void
9612 Target_arm<big_endian>::relocate_relocs(
9613     const Relocate_info<32, big_endian>* relinfo,
9614     unsigned int sh_type,
9615     const unsigned char* prelocs,
9616     size_t reloc_count,
9617     Output_section* output_section,
9618     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9619     const Relocatable_relocs* rr,
9620     unsigned char* view,
9621     Arm_address view_address,
9622     section_size_type view_size,
9623     unsigned char* reloc_view,
9624     section_size_type reloc_view_size)
9625 {
9626   gold_assert(sh_type == elfcpp::SHT_REL);
9627
9628   gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9629     relinfo,
9630     prelocs,
9631     reloc_count,
9632     output_section,
9633     offset_in_output_section,
9634     rr,
9635     view,
9636     view_address,
9637     view_size,
9638     reloc_view,
9639     reloc_view_size);
9640 }
9641
9642 // Perform target-specific processing in a relocatable link.  This is
9643 // only used if we use the relocation strategy RELOC_SPECIAL.
9644
9645 template<bool big_endian>
9646 void
9647 Target_arm<big_endian>::relocate_special_relocatable(
9648     const Relocate_info<32, big_endian>* relinfo,
9649     unsigned int sh_type,
9650     const unsigned char* preloc_in,
9651     size_t relnum,
9652     Output_section* output_section,
9653     typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9654     unsigned char* view,
9655     elfcpp::Elf_types<32>::Elf_Addr view_address,
9656     section_size_type,
9657     unsigned char* preloc_out)
9658 {
9659   // We can only handle REL type relocation sections.
9660   gold_assert(sh_type == elfcpp::SHT_REL);
9661
9662   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9663   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9664     Reltype_write;
9665   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9666
9667   const Arm_relobj<big_endian>* object =
9668     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9669   const unsigned int local_count = object->local_symbol_count();
9670
9671   Reltype reloc(preloc_in);
9672   Reltype_write reloc_write(preloc_out);
9673
9674   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9675   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9676   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9677
9678   const Arm_reloc_property* arp =
9679     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9680   gold_assert(arp != NULL);
9681
9682   // Get the new symbol index.
9683   // We only use RELOC_SPECIAL strategy in local relocations.
9684   gold_assert(r_sym < local_count);
9685
9686   // We are adjusting a section symbol.  We need to find
9687   // the symbol table index of the section symbol for
9688   // the output section corresponding to input section
9689   // in which this symbol is defined.
9690   bool is_ordinary;
9691   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9692   gold_assert(is_ordinary);
9693   Output_section* os = object->output_section(shndx);
9694   gold_assert(os != NULL);
9695   gold_assert(os->needs_symtab_index());
9696   unsigned int new_symndx = os->symtab_index();
9697
9698   // Get the new offset--the location in the output section where
9699   // this relocation should be applied.
9700
9701   Arm_address offset = reloc.get_r_offset();
9702   Arm_address new_offset;
9703   if (offset_in_output_section != invalid_address)
9704     new_offset = offset + offset_in_output_section;
9705   else
9706     {
9707       section_offset_type sot_offset =
9708           convert_types<section_offset_type, Arm_address>(offset);
9709       section_offset_type new_sot_offset =
9710           output_section->output_offset(object, relinfo->data_shndx,
9711                                         sot_offset);
9712       gold_assert(new_sot_offset != -1);
9713       new_offset = new_sot_offset;
9714     }
9715
9716   // In an object file, r_offset is an offset within the section.
9717   // In an executable or dynamic object, generated by
9718   // --emit-relocs, r_offset is an absolute address.
9719   if (!parameters->options().relocatable())
9720     {
9721       new_offset += view_address;
9722       if (offset_in_output_section != invalid_address)
9723         new_offset -= offset_in_output_section;
9724     }
9725
9726   reloc_write.put_r_offset(new_offset);
9727   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9728
9729   // Handle the reloc addend.
9730   // The relocation uses a section symbol in the input file.
9731   // We are adjusting it to use a section symbol in the output
9732   // file.  The input section symbol refers to some address in
9733   // the input section.  We need the relocation in the output
9734   // file to refer to that same address.  This adjustment to
9735   // the addend is the same calculation we use for a simple
9736   // absolute relocation for the input section symbol.
9737
9738   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9739
9740   // Handle THUMB bit.
9741   Symbol_value<32> symval;
9742   Arm_address thumb_bit =
9743      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9744   if (thumb_bit != 0
9745       && arp->uses_thumb_bit()
9746       && ((psymval->value(object, 0) & 1) != 0))
9747     {
9748       Arm_address stripped_value =
9749         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9750       symval.set_output_value(stripped_value);
9751       psymval = &symval;
9752     }
9753
9754   unsigned char* paddend = view + offset;
9755   typename Arm_relocate_functions<big_endian>::Status reloc_status =
9756         Arm_relocate_functions<big_endian>::STATUS_OKAY;
9757   switch (r_type)
9758     {
9759     case elfcpp::R_ARM_ABS8:
9760       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9761                                                               psymval);
9762       break;
9763
9764     case elfcpp::R_ARM_ABS12:
9765       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9766                                                                psymval);
9767       break;
9768
9769     case elfcpp::R_ARM_ABS16:
9770       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9771                                                                psymval);
9772       break;
9773
9774     case elfcpp::R_ARM_THM_ABS5:
9775       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9776                                                                   object,
9777                                                                   psymval);
9778       break;
9779
9780     case elfcpp::R_ARM_MOVW_ABS_NC:
9781     case elfcpp::R_ARM_MOVW_PREL_NC:
9782     case elfcpp::R_ARM_MOVW_BREL_NC:
9783     case elfcpp::R_ARM_MOVW_BREL:
9784       reloc_status = Arm_relocate_functions<big_endian>::movw(
9785           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9786       break;
9787
9788     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9789     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9790     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9791     case elfcpp::R_ARM_THM_MOVW_BREL:
9792       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9793           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9794       break;
9795
9796     case elfcpp::R_ARM_THM_CALL:
9797     case elfcpp::R_ARM_THM_XPC22:
9798     case elfcpp::R_ARM_THM_JUMP24:
9799       reloc_status =
9800         Arm_relocate_functions<big_endian>::thumb_branch_common(
9801             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9802             false);
9803       break;
9804
9805     case elfcpp::R_ARM_PLT32:
9806     case elfcpp::R_ARM_CALL:
9807     case elfcpp::R_ARM_JUMP24:
9808     case elfcpp::R_ARM_XPC25:
9809       reloc_status =
9810         Arm_relocate_functions<big_endian>::arm_branch_common(
9811             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9812             false);
9813       break;
9814
9815     case elfcpp::R_ARM_THM_JUMP19:
9816       reloc_status =
9817         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9818                                                        psymval, 0, thumb_bit);
9819       break;
9820
9821     case elfcpp::R_ARM_THM_JUMP6:
9822       reloc_status =
9823         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9824                                                       0);
9825       break;
9826
9827     case elfcpp::R_ARM_THM_JUMP8:
9828       reloc_status =
9829         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9830                                                       0);
9831       break;
9832
9833     case elfcpp::R_ARM_THM_JUMP11:
9834       reloc_status =
9835         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9836                                                        0);
9837       break;
9838
9839     case elfcpp::R_ARM_PREL31:
9840       reloc_status =
9841         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9842                                                    thumb_bit);
9843       break;
9844
9845     case elfcpp::R_ARM_THM_PC8:
9846       reloc_status =
9847         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9848                                                     0);
9849       break;
9850
9851     case elfcpp::R_ARM_THM_PC12:
9852       reloc_status =
9853         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9854                                                      0);
9855       break;
9856
9857     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9858       reloc_status =
9859         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9860                                                       0, thumb_bit);
9861       break;
9862
9863     // These relocation truncate relocation results so we cannot handle them
9864     // in a relocatable link.
9865     case elfcpp::R_ARM_MOVT_ABS:
9866     case elfcpp::R_ARM_THM_MOVT_ABS:
9867     case elfcpp::R_ARM_MOVT_PREL:
9868     case elfcpp::R_ARM_MOVT_BREL:
9869     case elfcpp::R_ARM_THM_MOVT_PREL:
9870     case elfcpp::R_ARM_THM_MOVT_BREL:
9871     case elfcpp::R_ARM_ALU_PC_G0_NC:
9872     case elfcpp::R_ARM_ALU_PC_G0:
9873     case elfcpp::R_ARM_ALU_PC_G1_NC:
9874     case elfcpp::R_ARM_ALU_PC_G1:
9875     case elfcpp::R_ARM_ALU_PC_G2:
9876     case elfcpp::R_ARM_ALU_SB_G0_NC:
9877     case elfcpp::R_ARM_ALU_SB_G0:
9878     case elfcpp::R_ARM_ALU_SB_G1_NC:
9879     case elfcpp::R_ARM_ALU_SB_G1:
9880     case elfcpp::R_ARM_ALU_SB_G2:
9881     case elfcpp::R_ARM_LDR_PC_G0:
9882     case elfcpp::R_ARM_LDR_PC_G1:
9883     case elfcpp::R_ARM_LDR_PC_G2:
9884     case elfcpp::R_ARM_LDR_SB_G0:
9885     case elfcpp::R_ARM_LDR_SB_G1:
9886     case elfcpp::R_ARM_LDR_SB_G2:
9887     case elfcpp::R_ARM_LDRS_PC_G0:
9888     case elfcpp::R_ARM_LDRS_PC_G1:
9889     case elfcpp::R_ARM_LDRS_PC_G2:
9890     case elfcpp::R_ARM_LDRS_SB_G0:
9891     case elfcpp::R_ARM_LDRS_SB_G1:
9892     case elfcpp::R_ARM_LDRS_SB_G2:
9893     case elfcpp::R_ARM_LDC_PC_G0:
9894     case elfcpp::R_ARM_LDC_PC_G1:
9895     case elfcpp::R_ARM_LDC_PC_G2:
9896     case elfcpp::R_ARM_LDC_SB_G0:
9897     case elfcpp::R_ARM_LDC_SB_G1:
9898     case elfcpp::R_ARM_LDC_SB_G2:
9899       gold_error(_("cannot handle %s in a relocatable link"),
9900                  arp->name().c_str());
9901       break;
9902
9903     default:
9904       gold_unreachable();
9905     }
9906
9907   // Report any errors.
9908   switch (reloc_status)
9909     {
9910     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9911       break;
9912     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9913       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9914                              _("relocation overflow in %s"),
9915                              arp->name().c_str());
9916       break;
9917     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9918       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9919         _("unexpected opcode while processing relocation %s"),
9920         arp->name().c_str());
9921       break;
9922     default:
9923       gold_unreachable();
9924     }
9925 }
9926
9927 // Return the value to use for a dynamic symbol which requires special
9928 // treatment.  This is how we support equality comparisons of function
9929 // pointers across shared library boundaries, as described in the
9930 // processor specific ABI supplement.
9931
9932 template<bool big_endian>
9933 uint64_t
9934 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9935 {
9936   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9937   return this->plt_section()->address() + gsym->plt_offset();
9938 }
9939
9940 // Map platform-specific relocs to real relocs
9941 //
9942 template<bool big_endian>
9943 unsigned int
9944 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9945 {
9946   switch (r_type)
9947     {
9948     case elfcpp::R_ARM_TARGET1:
9949       // This is either R_ARM_ABS32 or R_ARM_REL32;
9950       return elfcpp::R_ARM_ABS32;
9951
9952     case elfcpp::R_ARM_TARGET2:
9953       // This can be any reloc type but usually is R_ARM_GOT_PREL
9954       return elfcpp::R_ARM_GOT_PREL;
9955
9956     default:
9957       return r_type;
9958     }
9959 }
9960
9961 // Whether if two EABI versions V1 and V2 are compatible.
9962
9963 template<bool big_endian>
9964 bool
9965 Target_arm<big_endian>::are_eabi_versions_compatible(
9966     elfcpp::Elf_Word v1,
9967     elfcpp::Elf_Word v2)
9968 {
9969   // v4 and v5 are the same spec before and after it was released,
9970   // so allow mixing them.
9971   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9972       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9973       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9974     return true;
9975
9976   return v1 == v2;
9977 }
9978
9979 // Combine FLAGS from an input object called NAME and the processor-specific
9980 // flags in the ELF header of the output.  Much of this is adapted from the
9981 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9982 // in bfd/elf32-arm.c.
9983
9984 template<bool big_endian>
9985 void
9986 Target_arm<big_endian>::merge_processor_specific_flags(
9987     const std::string& name,
9988     elfcpp::Elf_Word flags)
9989 {
9990   if (this->are_processor_specific_flags_set())
9991     {
9992       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9993
9994       // Nothing to merge if flags equal to those in output.
9995       if (flags == out_flags)
9996         return;
9997
9998       // Complain about various flag mismatches.
9999       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10000       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10001       if (!this->are_eabi_versions_compatible(version1, version2)
10002           && parameters->options().warn_mismatch())
10003         gold_error(_("Source object %s has EABI version %d but output has "
10004                      "EABI version %d."),
10005                    name.c_str(),
10006                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10007                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10008     }
10009   else
10010     {
10011       // If the input is the default architecture and had the default
10012       // flags then do not bother setting the flags for the output
10013       // architecture, instead allow future merges to do this.  If no
10014       // future merges ever set these flags then they will retain their
10015       // uninitialised values, which surprise surprise, correspond
10016       // to the default values.
10017       if (flags == 0)
10018         return;
10019
10020       // This is the first time, just copy the flags.
10021       // We only copy the EABI version for now.
10022       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10023     }
10024 }
10025
10026 // Adjust ELF file header.
10027 template<bool big_endian>
10028 void
10029 Target_arm<big_endian>::do_adjust_elf_header(
10030     unsigned char* view,
10031     int len)
10032 {
10033   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10034
10035   elfcpp::Ehdr<32, big_endian> ehdr(view);
10036   elfcpp::Elf_Word flags = this->processor_specific_flags();
10037   unsigned char e_ident[elfcpp::EI_NIDENT];
10038   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10039
10040   if (elfcpp::arm_eabi_version(flags)
10041       == elfcpp::EF_ARM_EABI_UNKNOWN)
10042     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10043   else
10044     e_ident[elfcpp::EI_OSABI] = 0;
10045   e_ident[elfcpp::EI_ABIVERSION] = 0;
10046
10047   // FIXME: Do EF_ARM_BE8 adjustment.
10048
10049   // If we're working in EABI_VER5, set the hard/soft float ABI flags
10050   // as appropriate.
10051   if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10052   {
10053     elfcpp::Elf_Half type = ehdr.get_e_type();
10054     if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10055       {
10056         Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10057         if (attr->int_value())
10058           flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10059         else
10060           flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10061         this->set_processor_specific_flags(flags);
10062       }
10063   }
10064   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10065   oehdr.put_e_ident(e_ident);
10066 }
10067
10068 // do_make_elf_object to override the same function in the base class.
10069 // We need to use a target-specific sub-class of
10070 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10071 // Hence we need to have our own ELF object creation.
10072
10073 template<bool big_endian>
10074 Object*
10075 Target_arm<big_endian>::do_make_elf_object(
10076     const std::string& name,
10077     Input_file* input_file,
10078     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10079 {
10080   int et = ehdr.get_e_type();
10081   // ET_EXEC files are valid input for --just-symbols/-R,
10082   // and we treat them as relocatable objects.
10083   if (et == elfcpp::ET_REL
10084       || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10085     {
10086       Arm_relobj<big_endian>* obj =
10087         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10088       obj->setup();
10089       return obj;
10090     }
10091   else if (et == elfcpp::ET_DYN)
10092     {
10093       Sized_dynobj<32, big_endian>* obj =
10094         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10095       obj->setup();
10096       return obj;
10097     }
10098   else
10099     {
10100       gold_error(_("%s: unsupported ELF file type %d"),
10101                  name.c_str(), et);
10102       return NULL;
10103     }
10104 }
10105
10106 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10107 // Returns -1 if no architecture could be read.
10108 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10109
10110 template<bool big_endian>
10111 int
10112 Target_arm<big_endian>::get_secondary_compatible_arch(
10113     const Attributes_section_data* pasd)
10114 {
10115   const Object_attribute* known_attributes =
10116     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10117
10118   // Note: the tag and its argument below are uleb128 values, though
10119   // currently-defined values fit in one byte for each.
10120   const std::string& sv =
10121     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10122   if (sv.size() == 2
10123       && sv.data()[0] == elfcpp::Tag_CPU_arch
10124       && (sv.data()[1] & 128) != 128)
10125    return sv.data()[1];
10126
10127   // This tag is "safely ignorable", so don't complain if it looks funny.
10128   return -1;
10129 }
10130
10131 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10132 // The tag is removed if ARCH is -1.
10133 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10134
10135 template<bool big_endian>
10136 void
10137 Target_arm<big_endian>::set_secondary_compatible_arch(
10138     Attributes_section_data* pasd,
10139     int arch)
10140 {
10141   Object_attribute* known_attributes =
10142     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10143
10144   if (arch == -1)
10145     {
10146       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10147       return;
10148     }
10149
10150   // Note: the tag and its argument below are uleb128 values, though
10151   // currently-defined values fit in one byte for each.
10152   char sv[3];
10153   sv[0] = elfcpp::Tag_CPU_arch;
10154   gold_assert(arch != 0);
10155   sv[1] = arch;
10156   sv[2] = '\0';
10157
10158   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10159 }
10160
10161 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10162 // into account.
10163 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10164
10165 template<bool big_endian>
10166 int
10167 Target_arm<big_endian>::tag_cpu_arch_combine(
10168     const char* name,
10169     int oldtag,
10170     int* secondary_compat_out,
10171     int newtag,
10172     int secondary_compat)
10173 {
10174 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10175   static const int v6t2[] =
10176     {
10177       T(V6T2),   // PRE_V4.
10178       T(V6T2),   // V4.
10179       T(V6T2),   // V4T.
10180       T(V6T2),   // V5T.
10181       T(V6T2),   // V5TE.
10182       T(V6T2),   // V5TEJ.
10183       T(V6T2),   // V6.
10184       T(V7),     // V6KZ.
10185       T(V6T2)    // V6T2.
10186     };
10187   static const int v6k[] =
10188     {
10189       T(V6K),    // PRE_V4.
10190       T(V6K),    // V4.
10191       T(V6K),    // V4T.
10192       T(V6K),    // V5T.
10193       T(V6K),    // V5TE.
10194       T(V6K),    // V5TEJ.
10195       T(V6K),    // V6.
10196       T(V6KZ),   // V6KZ.
10197       T(V7),     // V6T2.
10198       T(V6K)     // V6K.
10199     };
10200   static const int v7[] =
10201     {
10202       T(V7),     // PRE_V4.
10203       T(V7),     // V4.
10204       T(V7),     // V4T.
10205       T(V7),     // V5T.
10206       T(V7),     // V5TE.
10207       T(V7),     // V5TEJ.
10208       T(V7),     // V6.
10209       T(V7),     // V6KZ.
10210       T(V7),     // V6T2.
10211       T(V7),     // V6K.
10212       T(V7)      // V7.
10213     };
10214   static const int v6_m[] =
10215     {
10216       -1,        // PRE_V4.
10217       -1,        // V4.
10218       T(V6K),    // V4T.
10219       T(V6K),    // V5T.
10220       T(V6K),    // V5TE.
10221       T(V6K),    // V5TEJ.
10222       T(V6K),    // V6.
10223       T(V6KZ),   // V6KZ.
10224       T(V7),     // V6T2.
10225       T(V6K),    // V6K.
10226       T(V7),     // V7.
10227       T(V6_M)    // V6_M.
10228     };
10229   static const int v6s_m[] =
10230     {
10231       -1,        // PRE_V4.
10232       -1,        // V4.
10233       T(V6K),    // V4T.
10234       T(V6K),    // V5T.
10235       T(V6K),    // V5TE.
10236       T(V6K),    // V5TEJ.
10237       T(V6K),    // V6.
10238       T(V6KZ),   // V6KZ.
10239       T(V7),     // V6T2.
10240       T(V6K),    // V6K.
10241       T(V7),     // V7.
10242       T(V6S_M),  // V6_M.
10243       T(V6S_M)   // V6S_M.
10244     };
10245   static const int v7e_m[] =
10246     {
10247       -1,       // PRE_V4.
10248       -1,       // V4.
10249       T(V7E_M), // V4T.
10250       T(V7E_M), // V5T.
10251       T(V7E_M), // V5TE.
10252       T(V7E_M), // V5TEJ.
10253       T(V7E_M), // V6.
10254       T(V7E_M), // V6KZ.
10255       T(V7E_M), // V6T2.
10256       T(V7E_M), // V6K.
10257       T(V7E_M), // V7.
10258       T(V7E_M), // V6_M.
10259       T(V7E_M), // V6S_M.
10260       T(V7E_M)  // V7E_M.
10261     };
10262   static const int v4t_plus_v6_m[] =
10263     {
10264       -1,               // PRE_V4.
10265       -1,               // V4.
10266       T(V4T),           // V4T.
10267       T(V5T),           // V5T.
10268       T(V5TE),          // V5TE.
10269       T(V5TEJ),         // V5TEJ.
10270       T(V6),            // V6.
10271       T(V6KZ),          // V6KZ.
10272       T(V6T2),          // V6T2.
10273       T(V6K),           // V6K.
10274       T(V7),            // V7.
10275       T(V6_M),          // V6_M.
10276       T(V6S_M),         // V6S_M.
10277       T(V7E_M),         // V7E_M.
10278       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
10279     };
10280   static const int* comb[] =
10281     {
10282       v6t2,
10283       v6k,
10284       v7,
10285       v6_m,
10286       v6s_m,
10287       v7e_m,
10288       // Pseudo-architecture.
10289       v4t_plus_v6_m
10290     };
10291
10292   // Check we've not got a higher architecture than we know about.
10293
10294   if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10295     {
10296       gold_error(_("%s: unknown CPU architecture"), name);
10297       return -1;
10298     }
10299
10300   // Override old tag if we have a Tag_also_compatible_with on the output.
10301
10302   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10303       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10304     oldtag = T(V4T_PLUS_V6_M);
10305
10306   // And override the new tag if we have a Tag_also_compatible_with on the
10307   // input.
10308
10309   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10310       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10311     newtag = T(V4T_PLUS_V6_M);
10312
10313   // Architectures before V6KZ add features monotonically.
10314   int tagh = std::max(oldtag, newtag);
10315   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10316     return tagh;
10317
10318   int tagl = std::min(oldtag, newtag);
10319   int result = comb[tagh - T(V6T2)][tagl];
10320
10321   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10322   // as the canonical version.
10323   if (result == T(V4T_PLUS_V6_M))
10324     {
10325       result = T(V4T);
10326       *secondary_compat_out = T(V6_M);
10327     }
10328   else
10329     *secondary_compat_out = -1;
10330
10331   if (result == -1)
10332     {
10333       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10334                  name, oldtag, newtag);
10335       return -1;
10336     }
10337
10338   return result;
10339 #undef T
10340 }
10341
10342 // Helper to print AEABI enum tag value.
10343
10344 template<bool big_endian>
10345 std::string
10346 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10347 {
10348   static const char* aeabi_enum_names[] =
10349     { "", "variable-size", "32-bit", "" };
10350   const size_t aeabi_enum_names_size =
10351     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10352
10353   if (value < aeabi_enum_names_size)
10354     return std::string(aeabi_enum_names[value]);
10355   else
10356     {
10357       char buffer[100];
10358       sprintf(buffer, "<unknown value %u>", value);
10359       return std::string(buffer);
10360     }
10361 }
10362
10363 // Return the string value to store in TAG_CPU_name.
10364
10365 template<bool big_endian>
10366 std::string
10367 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10368 {
10369   static const char* name_table[] = {
10370     // These aren't real CPU names, but we can't guess
10371     // that from the architecture version alone.
10372    "Pre v4",
10373    "ARM v4",
10374    "ARM v4T",
10375    "ARM v5T",
10376    "ARM v5TE",
10377    "ARM v5TEJ",
10378    "ARM v6",
10379    "ARM v6KZ",
10380    "ARM v6T2",
10381    "ARM v6K",
10382    "ARM v7",
10383    "ARM v6-M",
10384    "ARM v6S-M",
10385    "ARM v7E-M"
10386  };
10387  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10388
10389   if (value < name_table_size)
10390     return std::string(name_table[value]);
10391   else
10392     {
10393       char buffer[100];
10394       sprintf(buffer, "<unknown CPU value %u>", value);
10395       return std::string(buffer);
10396     }
10397 }
10398
10399 // Query attributes object to see if integer divide instructions may be
10400 // present in an object.
10401
10402 template<bool big_endian>
10403 bool
10404 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10405     const Object_attribute* div_attr)
10406 {
10407   switch (div_attr->int_value())
10408     {
10409     case 0:
10410       // Integer divide allowed if instruction contained in
10411       // archetecture.
10412       if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10413         return true;
10414       else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10415         return true;
10416       else
10417         return false;
10418
10419     case 1:
10420       // Integer divide explicitly prohibited.
10421       return false;
10422
10423     default:
10424       // Unrecognised case - treat as allowing divide everywhere.
10425     case 2:
10426       // Integer divide allowed in ARM state.
10427       return true;
10428     }
10429 }
10430
10431 // Query attributes object to see if integer divide instructions are
10432 // forbidden to be in the object.  This is not the inverse of
10433 // attributes_accept_div.
10434
10435 template<bool big_endian>
10436 bool
10437 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10438 {
10439   return div_attr->int_value() == 1;
10440 }
10441
10442 // Merge object attributes from input file called NAME with those of the
10443 // output.  The input object attributes are in the object pointed by PASD.
10444
10445 template<bool big_endian>
10446 void
10447 Target_arm<big_endian>::merge_object_attributes(
10448     const char* name,
10449     const Attributes_section_data* pasd)
10450 {
10451   // Return if there is no attributes section data.
10452   if (pasd == NULL)
10453     return;
10454
10455   // If output has no object attributes, just copy.
10456   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10457   if (this->attributes_section_data_ == NULL)
10458     {
10459       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10460       Object_attribute* out_attr =
10461         this->attributes_section_data_->known_attributes(vendor);
10462
10463       // We do not output objects with Tag_MPextension_use_legacy - we move
10464       //  the attribute's value to Tag_MPextension_use.  */
10465       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10466         {
10467           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10468               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10469                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10470             {
10471               gold_error(_("%s has both the current and legacy "
10472                            "Tag_MPextension_use attributes"),
10473                          name);
10474             }
10475
10476           out_attr[elfcpp::Tag_MPextension_use] =
10477             out_attr[elfcpp::Tag_MPextension_use_legacy];
10478           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10479           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10480         }
10481
10482       return;
10483     }
10484
10485   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10486   Object_attribute* out_attr =
10487     this->attributes_section_data_->known_attributes(vendor);
10488
10489   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10490   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10491       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10492     {
10493       // Ignore mismatches if the object doesn't use floating point.  */
10494       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10495         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10496             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10497       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10498                && parameters->options().warn_mismatch())
10499         gold_error(_("%s uses VFP register arguments, output does not"),
10500                    name);
10501     }
10502
10503   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10504     {
10505       // Merge this attribute with existing attributes.
10506       switch (i)
10507         {
10508         case elfcpp::Tag_CPU_raw_name:
10509         case elfcpp::Tag_CPU_name:
10510           // These are merged after Tag_CPU_arch.
10511           break;
10512
10513         case elfcpp::Tag_ABI_optimization_goals:
10514         case elfcpp::Tag_ABI_FP_optimization_goals:
10515           // Use the first value seen.
10516           break;
10517
10518         case elfcpp::Tag_CPU_arch:
10519           {
10520             unsigned int saved_out_attr = out_attr->int_value();
10521             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10522             int secondary_compat =
10523               this->get_secondary_compatible_arch(pasd);
10524             int secondary_compat_out =
10525               this->get_secondary_compatible_arch(
10526                   this->attributes_section_data_);
10527             out_attr[i].set_int_value(
10528                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10529                                      &secondary_compat_out,
10530                                      in_attr[i].int_value(),
10531                                      secondary_compat));
10532             this->set_secondary_compatible_arch(this->attributes_section_data_,
10533                                                 secondary_compat_out);
10534
10535             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10536             if (out_attr[i].int_value() == saved_out_attr)
10537               ; // Leave the names alone.
10538             else if (out_attr[i].int_value() == in_attr[i].int_value())
10539               {
10540                 // The output architecture has been changed to match the
10541                 // input architecture.  Use the input names.
10542                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10543                     in_attr[elfcpp::Tag_CPU_name].string_value());
10544                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10545                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10546               }
10547             else
10548               {
10549                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10550                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10551               }
10552
10553             // If we still don't have a value for Tag_CPU_name,
10554             // make one up now.  Tag_CPU_raw_name remains blank.
10555             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10556               {
10557                 const std::string cpu_name =
10558                   this->tag_cpu_name_value(out_attr[i].int_value());
10559                 // FIXME:  If we see an unknown CPU, this will be set
10560                 // to "<unknown CPU n>", where n is the attribute value.
10561                 // This is different from BFD, which leaves the name alone.
10562                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10563               }
10564           }
10565           break;
10566
10567         case elfcpp::Tag_ARM_ISA_use:
10568         case elfcpp::Tag_THUMB_ISA_use:
10569         case elfcpp::Tag_WMMX_arch:
10570         case elfcpp::Tag_Advanced_SIMD_arch:
10571           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10572         case elfcpp::Tag_ABI_FP_rounding:
10573         case elfcpp::Tag_ABI_FP_exceptions:
10574         case elfcpp::Tag_ABI_FP_user_exceptions:
10575         case elfcpp::Tag_ABI_FP_number_model:
10576         case elfcpp::Tag_VFP_HP_extension:
10577         case elfcpp::Tag_CPU_unaligned_access:
10578         case elfcpp::Tag_T2EE_use:
10579         case elfcpp::Tag_Virtualization_use:
10580         case elfcpp::Tag_MPextension_use:
10581           // Use the largest value specified.
10582           if (in_attr[i].int_value() > out_attr[i].int_value())
10583             out_attr[i].set_int_value(in_attr[i].int_value());
10584           break;
10585
10586         case elfcpp::Tag_ABI_align8_preserved:
10587         case elfcpp::Tag_ABI_PCS_RO_data:
10588           // Use the smallest value specified.
10589           if (in_attr[i].int_value() < out_attr[i].int_value())
10590             out_attr[i].set_int_value(in_attr[i].int_value());
10591           break;
10592
10593         case elfcpp::Tag_ABI_align8_needed:
10594           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10595               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10596                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10597                       == 0)))
10598             {
10599               // This error message should be enabled once all non-conforming
10600               // binaries in the toolchain have had the attributes set
10601               // properly.
10602               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10603               //            name);
10604             }
10605           // Fall through.
10606         case elfcpp::Tag_ABI_FP_denormal:
10607         case elfcpp::Tag_ABI_PCS_GOT_use:
10608           {
10609             // These tags have 0 = don't care, 1 = strong requirement,
10610             // 2 = weak requirement.
10611             static const int order_021[3] = {0, 2, 1};
10612
10613             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10614             // value if greater than 2 (for future-proofing).
10615             if ((in_attr[i].int_value() > 2
10616                  && in_attr[i].int_value() > out_attr[i].int_value())
10617                 || (in_attr[i].int_value() <= 2
10618                     && out_attr[i].int_value() <= 2
10619                     && (order_021[in_attr[i].int_value()]
10620                         > order_021[out_attr[i].int_value()])))
10621               out_attr[i].set_int_value(in_attr[i].int_value());
10622           }
10623           break;
10624
10625         case elfcpp::Tag_CPU_arch_profile:
10626           if (out_attr[i].int_value() != in_attr[i].int_value())
10627             {
10628               // 0 will merge with anything.
10629               // 'A' and 'S' merge to 'A'.
10630               // 'R' and 'S' merge to 'R'.
10631               // 'M' and 'A|R|S' is an error.
10632               if (out_attr[i].int_value() == 0
10633                   || (out_attr[i].int_value() == 'S'
10634                       && (in_attr[i].int_value() == 'A'
10635                           || in_attr[i].int_value() == 'R')))
10636                 out_attr[i].set_int_value(in_attr[i].int_value());
10637               else if (in_attr[i].int_value() == 0
10638                        || (in_attr[i].int_value() == 'S'
10639                            && (out_attr[i].int_value() == 'A'
10640                                || out_attr[i].int_value() == 'R')))
10641                 ; // Do nothing.
10642               else if (parameters->options().warn_mismatch())
10643                 {
10644                   gold_error
10645                     (_("conflicting architecture profiles %c/%c"),
10646                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10647                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10648                 }
10649             }
10650           break;
10651         case elfcpp::Tag_VFP_arch:
10652             {
10653               static const struct
10654               {
10655                   int ver;
10656                   int regs;
10657               } vfp_versions[7] =
10658                 {
10659                   {0, 0},
10660                   {1, 16},
10661                   {2, 16},
10662                   {3, 32},
10663                   {3, 16},
10664                   {4, 32},
10665                   {4, 16}
10666                 };
10667
10668               // Values greater than 6 aren't defined, so just pick the
10669               // biggest.
10670               if (in_attr[i].int_value() > 6
10671                   && in_attr[i].int_value() > out_attr[i].int_value())
10672                 {
10673                   *out_attr = *in_attr;
10674                   break;
10675                 }
10676               // The output uses the superset of input features
10677               // (ISA version) and registers.
10678               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10679                                  vfp_versions[out_attr[i].int_value()].ver);
10680               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10681                                   vfp_versions[out_attr[i].int_value()].regs);
10682               // This assumes all possible supersets are also a valid
10683               // options.
10684               int newval;
10685               for (newval = 6; newval > 0; newval--)
10686                 {
10687                   if (regs == vfp_versions[newval].regs
10688                       && ver == vfp_versions[newval].ver)
10689                     break;
10690                 }
10691               out_attr[i].set_int_value(newval);
10692             }
10693           break;
10694         case elfcpp::Tag_PCS_config:
10695           if (out_attr[i].int_value() == 0)
10696             out_attr[i].set_int_value(in_attr[i].int_value());
10697           else if (in_attr[i].int_value() != 0
10698                    && out_attr[i].int_value() != 0
10699                    && parameters->options().warn_mismatch())
10700             {
10701               // It's sometimes ok to mix different configs, so this is only
10702               // a warning.
10703               gold_warning(_("%s: conflicting platform configuration"), name);
10704             }
10705           break;
10706         case elfcpp::Tag_ABI_PCS_R9_use:
10707           if (in_attr[i].int_value() != out_attr[i].int_value()
10708               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10709               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10710               && parameters->options().warn_mismatch())
10711             {
10712               gold_error(_("%s: conflicting use of R9"), name);
10713             }
10714           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10715             out_attr[i].set_int_value(in_attr[i].int_value());
10716           break;
10717         case elfcpp::Tag_ABI_PCS_RW_data:
10718           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10719               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10720                   != elfcpp::AEABI_R9_SB)
10721               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10722                   != elfcpp::AEABI_R9_unused)
10723               && parameters->options().warn_mismatch())
10724             {
10725               gold_error(_("%s: SB relative addressing conflicts with use "
10726                            "of R9"),
10727                            name);
10728             }
10729           // Use the smallest value specified.
10730           if (in_attr[i].int_value() < out_attr[i].int_value())
10731             out_attr[i].set_int_value(in_attr[i].int_value());
10732           break;
10733         case elfcpp::Tag_ABI_PCS_wchar_t:
10734           if (out_attr[i].int_value()
10735               && in_attr[i].int_value()
10736               && out_attr[i].int_value() != in_attr[i].int_value()
10737               && parameters->options().warn_mismatch()
10738               && parameters->options().wchar_size_warning())
10739             {
10740               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10741                              "use %u-byte wchar_t; use of wchar_t values "
10742                              "across objects may fail"),
10743                            name, in_attr[i].int_value(),
10744                            out_attr[i].int_value());
10745             }
10746           else if (in_attr[i].int_value() && !out_attr[i].int_value())
10747             out_attr[i].set_int_value(in_attr[i].int_value());
10748           break;
10749         case elfcpp::Tag_ABI_enum_size:
10750           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10751             {
10752               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10753                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10754                 {
10755                   // The existing object is compatible with anything.
10756                   // Use whatever requirements the new object has.
10757                   out_attr[i].set_int_value(in_attr[i].int_value());
10758                 }
10759               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10760                        && out_attr[i].int_value() != in_attr[i].int_value()
10761                        && parameters->options().warn_mismatch()
10762                        && parameters->options().enum_size_warning())
10763                 {
10764                   unsigned int in_value = in_attr[i].int_value();
10765                   unsigned int out_value = out_attr[i].int_value();
10766                   gold_warning(_("%s uses %s enums yet the output is to use "
10767                                  "%s enums; use of enum values across objects "
10768                                  "may fail"),
10769                                name,
10770                                this->aeabi_enum_name(in_value).c_str(),
10771                                this->aeabi_enum_name(out_value).c_str());
10772                 }
10773             }
10774           break;
10775         case elfcpp::Tag_ABI_VFP_args:
10776           // Already done.
10777           break;
10778         case elfcpp::Tag_ABI_WMMX_args:
10779           if (in_attr[i].int_value() != out_attr[i].int_value()
10780               && parameters->options().warn_mismatch())
10781             {
10782               gold_error(_("%s uses iWMMXt register arguments, output does "
10783                            "not"),
10784                          name);
10785             }
10786           break;
10787         case Object_attribute::Tag_compatibility:
10788           // Merged in target-independent code.
10789           break;
10790         case elfcpp::Tag_ABI_HardFP_use:
10791           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10792           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10793               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10794             out_attr[i].set_int_value(3);
10795           else if (in_attr[i].int_value() > out_attr[i].int_value())
10796             out_attr[i].set_int_value(in_attr[i].int_value());
10797           break;
10798         case elfcpp::Tag_ABI_FP_16bit_format:
10799           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10800             {
10801               if (in_attr[i].int_value() != out_attr[i].int_value()
10802                   && parameters->options().warn_mismatch())
10803                 gold_error(_("fp16 format mismatch between %s and output"),
10804                            name);
10805             }
10806           if (in_attr[i].int_value() != 0)
10807             out_attr[i].set_int_value(in_attr[i].int_value());
10808           break;
10809
10810         case elfcpp::Tag_DIV_use:
10811           {
10812             // A value of zero on input means that the divide
10813             // instruction may be used if available in the base
10814             // architecture as specified via Tag_CPU_arch and
10815             // Tag_CPU_arch_profile.  A value of 1 means that the user
10816             // did not want divide instructions.  A value of 2
10817             // explicitly means that divide instructions were allowed
10818             // in ARM and Thumb state.
10819             int arch = this->
10820               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
10821               int_value();
10822             int profile = this->
10823               get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
10824               int_value();
10825             if (in_attr[i].int_value() == out_attr[i].int_value())
10826               {
10827                 // Do nothing.
10828               }
10829             else if (attributes_forbid_div(&in_attr[i])
10830                      && !attributes_accept_div(arch, profile, &out_attr[i]))
10831               out_attr[i].set_int_value(1);
10832             else if (attributes_forbid_div(&out_attr[i])
10833                      && attributes_accept_div(arch, profile, &in_attr[i]))
10834               out_attr[i].set_int_value(in_attr[i].int_value());
10835             else if (in_attr[i].int_value() == 2)
10836               out_attr[i].set_int_value(in_attr[i].int_value());
10837           }
10838           break;
10839
10840         case elfcpp::Tag_MPextension_use_legacy:
10841           // We don't output objects with Tag_MPextension_use_legacy - we
10842           // move the value to Tag_MPextension_use.
10843           if (in_attr[i].int_value() != 0
10844               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10845             {
10846               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10847                   != in_attr[i].int_value())
10848                 {
10849                   gold_error(_("%s has has both the current and legacy "
10850                                "Tag_MPextension_use attributes"),
10851                              name);
10852                 }
10853             }
10854
10855           if (in_attr[i].int_value()
10856               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10857             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10858
10859           break;
10860
10861         case elfcpp::Tag_nodefaults:
10862           // This tag is set if it exists, but the value is unused (and is
10863           // typically zero).  We don't actually need to do anything here -
10864           // the merge happens automatically when the type flags are merged
10865           // below.
10866           break;
10867         case elfcpp::Tag_also_compatible_with:
10868           // Already done in Tag_CPU_arch.
10869           break;
10870         case elfcpp::Tag_conformance:
10871           // Keep the attribute if it matches.  Throw it away otherwise.
10872           // No attribute means no claim to conform.
10873           if (in_attr[i].string_value() != out_attr[i].string_value())
10874             out_attr[i].set_string_value("");
10875           break;
10876
10877         default:
10878           {
10879             const char* err_object = NULL;
10880
10881             // The "known_obj_attributes" table does contain some undefined
10882             // attributes.  Ensure that there are unused.
10883             if (out_attr[i].int_value() != 0
10884                 || out_attr[i].string_value() != "")
10885               err_object = "output";
10886             else if (in_attr[i].int_value() != 0
10887                      || in_attr[i].string_value() != "")
10888               err_object = name;
10889
10890             if (err_object != NULL
10891                 && parameters->options().warn_mismatch())
10892               {
10893                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10894                 if ((i & 127) < 64)
10895                   gold_error(_("%s: unknown mandatory EABI object attribute "
10896                                "%d"),
10897                              err_object, i);
10898                 else
10899                   gold_warning(_("%s: unknown EABI object attribute %d"),
10900                                err_object, i);
10901               }
10902
10903             // Only pass on attributes that match in both inputs.
10904             if (!in_attr[i].matches(out_attr[i]))
10905               {
10906                 out_attr[i].set_int_value(0);
10907                 out_attr[i].set_string_value("");
10908               }
10909           }
10910         }
10911
10912       // If out_attr was copied from in_attr then it won't have a type yet.
10913       if (in_attr[i].type() && !out_attr[i].type())
10914         out_attr[i].set_type(in_attr[i].type());
10915     }
10916
10917   // Merge Tag_compatibility attributes and any common GNU ones.
10918   this->attributes_section_data_->merge(name, pasd);
10919
10920   // Check for any attributes not known on ARM.
10921   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10922   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10923   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10924   Other_attributes* out_other_attributes =
10925     this->attributes_section_data_->other_attributes(vendor);
10926   Other_attributes::iterator out_iter = out_other_attributes->begin();
10927
10928   while (in_iter != in_other_attributes->end()
10929          || out_iter != out_other_attributes->end())
10930     {
10931       const char* err_object = NULL;
10932       int err_tag = 0;
10933
10934       // The tags for each list are in numerical order.
10935       // If the tags are equal, then merge.
10936       if (out_iter != out_other_attributes->end()
10937           && (in_iter == in_other_attributes->end()
10938               || in_iter->first > out_iter->first))
10939         {
10940           // This attribute only exists in output.  We can't merge, and we
10941           // don't know what the tag means, so delete it.
10942           err_object = "output";
10943           err_tag = out_iter->first;
10944           int saved_tag = out_iter->first;
10945           delete out_iter->second;
10946           out_other_attributes->erase(out_iter);
10947           out_iter = out_other_attributes->upper_bound(saved_tag);
10948         }
10949       else if (in_iter != in_other_attributes->end()
10950                && (out_iter != out_other_attributes->end()
10951                    || in_iter->first < out_iter->first))
10952         {
10953           // This attribute only exists in input. We can't merge, and we
10954           // don't know what the tag means, so ignore it.
10955           err_object = name;
10956           err_tag = in_iter->first;
10957           ++in_iter;
10958         }
10959       else // The tags are equal.
10960         {
10961           // As present, all attributes in the list are unknown, and
10962           // therefore can't be merged meaningfully.
10963           err_object = "output";
10964           err_tag = out_iter->first;
10965
10966           //  Only pass on attributes that match in both inputs.
10967           if (!in_iter->second->matches(*(out_iter->second)))
10968             {
10969               // No match.  Delete the attribute.
10970               int saved_tag = out_iter->first;
10971               delete out_iter->second;
10972               out_other_attributes->erase(out_iter);
10973               out_iter = out_other_attributes->upper_bound(saved_tag);
10974             }
10975           else
10976             {
10977               // Matched.  Keep the attribute and move to the next.
10978               ++out_iter;
10979               ++in_iter;
10980             }
10981         }
10982
10983       if (err_object && parameters->options().warn_mismatch())
10984         {
10985           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10986           if ((err_tag & 127) < 64)
10987             {
10988               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10989                          err_object, err_tag);
10990             }
10991           else
10992             {
10993               gold_warning(_("%s: unknown EABI object attribute %d"),
10994                            err_object, err_tag);
10995             }
10996         }
10997     }
10998 }
10999
11000 // Stub-generation methods for Target_arm.
11001
11002 // Make a new Arm_input_section object.
11003
11004 template<bool big_endian>
11005 Arm_input_section<big_endian>*
11006 Target_arm<big_endian>::new_arm_input_section(
11007     Relobj* relobj,
11008     unsigned int shndx)
11009 {
11010   Section_id sid(relobj, shndx);
11011
11012   Arm_input_section<big_endian>* arm_input_section =
11013     new Arm_input_section<big_endian>(relobj, shndx);
11014   arm_input_section->init();
11015
11016   // Register new Arm_input_section in map for look-up.
11017   std::pair<typename Arm_input_section_map::iterator, bool> ins =
11018     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11019
11020   // Make sure that it we have not created another Arm_input_section
11021   // for this input section already.
11022   gold_assert(ins.second);
11023
11024   return arm_input_section;
11025 }
11026
11027 // Find the Arm_input_section object corresponding to the SHNDX-th input
11028 // section of RELOBJ.
11029
11030 template<bool big_endian>
11031 Arm_input_section<big_endian>*
11032 Target_arm<big_endian>::find_arm_input_section(
11033     Relobj* relobj,
11034     unsigned int shndx) const
11035 {
11036   Section_id sid(relobj, shndx);
11037   typename Arm_input_section_map::const_iterator p =
11038     this->arm_input_section_map_.find(sid);
11039   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11040 }
11041
11042 // Make a new stub table.
11043
11044 template<bool big_endian>
11045 Stub_table<big_endian>*
11046 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11047 {
11048   Stub_table<big_endian>* stub_table =
11049     new Stub_table<big_endian>(owner);
11050   this->stub_tables_.push_back(stub_table);
11051
11052   stub_table->set_address(owner->address() + owner->data_size());
11053   stub_table->set_file_offset(owner->offset() + owner->data_size());
11054   stub_table->finalize_data_size();
11055
11056   return stub_table;
11057 }
11058
11059 // Scan a relocation for stub generation.
11060
11061 template<bool big_endian>
11062 void
11063 Target_arm<big_endian>::scan_reloc_for_stub(
11064     const Relocate_info<32, big_endian>* relinfo,
11065     unsigned int r_type,
11066     const Sized_symbol<32>* gsym,
11067     unsigned int r_sym,
11068     const Symbol_value<32>* psymval,
11069     elfcpp::Elf_types<32>::Elf_Swxword addend,
11070     Arm_address address)
11071 {
11072   const Arm_relobj<big_endian>* arm_relobj =
11073     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11074
11075   bool target_is_thumb;
11076   Symbol_value<32> symval;
11077   if (gsym != NULL)
11078     {
11079       // This is a global symbol.  Determine if we use PLT and if the
11080       // final target is THUMB.
11081       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11082         {
11083           // This uses a PLT, change the symbol value.
11084           symval.set_output_value(this->plt_section()->address()
11085                                   + gsym->plt_offset());
11086           psymval = &symval;
11087           target_is_thumb = false;
11088         }
11089       else if (gsym->is_undefined())
11090         // There is no need to generate a stub symbol is undefined.
11091         return;
11092       else
11093         {
11094           target_is_thumb =
11095             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11096              || (gsym->type() == elfcpp::STT_FUNC
11097                  && !gsym->is_undefined()
11098                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11099         }
11100     }
11101   else
11102     {
11103       // This is a local symbol.  Determine if the final target is THUMB.
11104       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11105     }
11106
11107   // Strip LSB if this points to a THUMB target.
11108   const Arm_reloc_property* reloc_property =
11109     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11110   gold_assert(reloc_property != NULL);
11111   if (target_is_thumb
11112       && reloc_property->uses_thumb_bit()
11113       && ((psymval->value(arm_relobj, 0) & 1) != 0))
11114     {
11115       Arm_address stripped_value =
11116         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11117       symval.set_output_value(stripped_value);
11118       psymval = &symval;
11119     }
11120
11121   // Get the symbol value.
11122   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11123
11124   // Owing to pipelining, the PC relative branches below actually skip
11125   // two instructions when the branch offset is 0.
11126   Arm_address destination;
11127   switch (r_type)
11128     {
11129     case elfcpp::R_ARM_CALL:
11130     case elfcpp::R_ARM_JUMP24:
11131     case elfcpp::R_ARM_PLT32:
11132       // ARM branches.
11133       destination = value + addend + 8;
11134       break;
11135     case elfcpp::R_ARM_THM_CALL:
11136     case elfcpp::R_ARM_THM_XPC22:
11137     case elfcpp::R_ARM_THM_JUMP24:
11138     case elfcpp::R_ARM_THM_JUMP19:
11139       // THUMB branches.
11140       destination = value + addend + 4;
11141       break;
11142     default:
11143       gold_unreachable();
11144     }
11145
11146   Reloc_stub* stub = NULL;
11147   Stub_type stub_type =
11148     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11149                                     target_is_thumb);
11150   if (stub_type != arm_stub_none)
11151     {
11152       // Try looking up an existing stub from a stub table.
11153       Stub_table<big_endian>* stub_table =
11154         arm_relobj->stub_table(relinfo->data_shndx);
11155       gold_assert(stub_table != NULL);
11156
11157       // Locate stub by destination.
11158       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11159
11160       // Create a stub if there is not one already
11161       stub = stub_table->find_reloc_stub(stub_key);
11162       if (stub == NULL)
11163         {
11164           // create a new stub and add it to stub table.
11165           stub = this->stub_factory().make_reloc_stub(stub_type);
11166           stub_table->add_reloc_stub(stub, stub_key);
11167         }
11168
11169       // Record the destination address.
11170       stub->set_destination_address(destination
11171                                     | (target_is_thumb ? 1 : 0));
11172     }
11173
11174   // For Cortex-A8, we need to record a relocation at 4K page boundary.
11175   if (this->fix_cortex_a8_
11176       && (r_type == elfcpp::R_ARM_THM_JUMP24
11177           || r_type == elfcpp::R_ARM_THM_JUMP19
11178           || r_type == elfcpp::R_ARM_THM_CALL
11179           || r_type == elfcpp::R_ARM_THM_XPC22)
11180       && (address & 0xfffU) == 0xffeU)
11181     {
11182       // Found a candidate.  Note we haven't checked the destination is
11183       // within 4K here: if we do so (and don't create a record) we can't
11184       // tell that a branch should have been relocated when scanning later.
11185       this->cortex_a8_relocs_info_[address] =
11186         new Cortex_a8_reloc(stub, r_type,
11187                             destination | (target_is_thumb ? 1 : 0));
11188     }
11189 }
11190
11191 // This function scans a relocation sections for stub generation.
11192 // The template parameter Relocate must be a class type which provides
11193 // a single function, relocate(), which implements the machine
11194 // specific part of a relocation.
11195
11196 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
11197 // SHT_REL or SHT_RELA.
11198
11199 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
11200 // of relocs.  OUTPUT_SECTION is the output section.
11201 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11202 // mapped to output offsets.
11203
11204 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11205 // VIEW_SIZE is the size.  These refer to the input section, unless
11206 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11207 // the output section.
11208
11209 template<bool big_endian>
11210 template<int sh_type>
11211 void inline
11212 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11213     const Relocate_info<32, big_endian>* relinfo,
11214     const unsigned char* prelocs,
11215     size_t reloc_count,
11216     Output_section* output_section,
11217     bool needs_special_offset_handling,
11218     const unsigned char* view,
11219     elfcpp::Elf_types<32>::Elf_Addr view_address,
11220     section_size_type)
11221 {
11222   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11223   const int reloc_size =
11224     Reloc_types<sh_type, 32, big_endian>::reloc_size;
11225
11226   Arm_relobj<big_endian>* arm_object =
11227     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11228   unsigned int local_count = arm_object->local_symbol_count();
11229
11230   gold::Default_comdat_behavior default_comdat_behavior;
11231   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11232
11233   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11234     {
11235       Reltype reloc(prelocs);
11236
11237       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11238       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11239       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11240
11241       r_type = this->get_real_reloc_type(r_type);
11242
11243       // Only a few relocation types need stubs.
11244       if ((r_type != elfcpp::R_ARM_CALL)
11245          && (r_type != elfcpp::R_ARM_JUMP24)
11246          && (r_type != elfcpp::R_ARM_PLT32)
11247          && (r_type != elfcpp::R_ARM_THM_CALL)
11248          && (r_type != elfcpp::R_ARM_THM_XPC22)
11249          && (r_type != elfcpp::R_ARM_THM_JUMP24)
11250          && (r_type != elfcpp::R_ARM_THM_JUMP19)
11251          && (r_type != elfcpp::R_ARM_V4BX))
11252         continue;
11253
11254       section_offset_type offset =
11255         convert_to_section_size_type(reloc.get_r_offset());
11256
11257       if (needs_special_offset_handling)
11258         {
11259           offset = output_section->output_offset(relinfo->object,
11260                                                  relinfo->data_shndx,
11261                                                  offset);
11262           if (offset == -1)
11263             continue;
11264         }
11265
11266       // Create a v4bx stub if --fix-v4bx-interworking is used.
11267       if (r_type == elfcpp::R_ARM_V4BX)
11268         {
11269           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11270             {
11271               // Get the BX instruction.
11272               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11273               const Valtype* wv =
11274                 reinterpret_cast<const Valtype*>(view + offset);
11275               elfcpp::Elf_types<32>::Elf_Swxword insn =
11276                 elfcpp::Swap<32, big_endian>::readval(wv);
11277               const uint32_t reg = (insn & 0xf);
11278
11279               if (reg < 0xf)
11280                 {
11281                   // Try looking up an existing stub from a stub table.
11282                   Stub_table<big_endian>* stub_table =
11283                     arm_object->stub_table(relinfo->data_shndx);
11284                   gold_assert(stub_table != NULL);
11285
11286                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11287                     {
11288                       // create a new stub and add it to stub table.
11289                       Arm_v4bx_stub* stub =
11290                         this->stub_factory().make_arm_v4bx_stub(reg);
11291                       gold_assert(stub != NULL);
11292                       stub_table->add_arm_v4bx_stub(stub);
11293                     }
11294                 }
11295             }
11296           continue;
11297         }
11298
11299       // Get the addend.
11300       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11301       elfcpp::Elf_types<32>::Elf_Swxword addend =
11302         stub_addend_reader(r_type, view + offset, reloc);
11303
11304       const Sized_symbol<32>* sym;
11305
11306       Symbol_value<32> symval;
11307       const Symbol_value<32> *psymval;
11308       bool is_defined_in_discarded_section;
11309       unsigned int shndx;
11310       if (r_sym < local_count)
11311         {
11312           sym = NULL;
11313           psymval = arm_object->local_symbol(r_sym);
11314
11315           // If the local symbol belongs to a section we are discarding,
11316           // and that section is a debug section, try to find the
11317           // corresponding kept section and map this symbol to its
11318           // counterpart in the kept section.  The symbol must not
11319           // correspond to a section we are folding.
11320           bool is_ordinary;
11321           shndx = psymval->input_shndx(&is_ordinary);
11322           is_defined_in_discarded_section =
11323             (is_ordinary
11324              && shndx != elfcpp::SHN_UNDEF
11325              && !arm_object->is_section_included(shndx)
11326              && !relinfo->symtab->is_section_folded(arm_object, shndx));
11327
11328           // We need to compute the would-be final value of this local
11329           // symbol.
11330           if (!is_defined_in_discarded_section)
11331             {
11332               typedef Sized_relobj_file<32, big_endian> ObjType;
11333               typename ObjType::Compute_final_local_value_status status =
11334                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11335                                                       relinfo->symtab);
11336               if (status == ObjType::CFLV_OK)
11337                 {
11338                   // Currently we cannot handle a branch to a target in
11339                   // a merged section.  If this is the case, issue an error
11340                   // and also free the merge symbol value.
11341                   if (!symval.has_output_value())
11342                     {
11343                       const std::string& section_name =
11344                         arm_object->section_name(shndx);
11345                       arm_object->error(_("cannot handle branch to local %u "
11346                                           "in a merged section %s"),
11347                                         r_sym, section_name.c_str());
11348                     }
11349                   psymval = &symval;
11350                 }
11351               else
11352                 {
11353                   // We cannot determine the final value.
11354                   continue;
11355                 }
11356             }
11357         }
11358       else
11359         {
11360           const Symbol* gsym;
11361           gsym = arm_object->global_symbol(r_sym);
11362           gold_assert(gsym != NULL);
11363           if (gsym->is_forwarder())
11364             gsym = relinfo->symtab->resolve_forwards(gsym);
11365
11366           sym = static_cast<const Sized_symbol<32>*>(gsym);
11367           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11368             symval.set_output_symtab_index(sym->symtab_index());
11369           else
11370             symval.set_no_output_symtab_entry();
11371
11372           // We need to compute the would-be final value of this global
11373           // symbol.
11374           const Symbol_table* symtab = relinfo->symtab;
11375           const Sized_symbol<32>* sized_symbol =
11376             symtab->get_sized_symbol<32>(gsym);
11377           Symbol_table::Compute_final_value_status status;
11378           Arm_address value =
11379             symtab->compute_final_value<32>(sized_symbol, &status);
11380
11381           // Skip this if the symbol has not output section.
11382           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11383             continue;
11384           symval.set_output_value(value);
11385
11386           if (gsym->type() == elfcpp::STT_TLS)
11387             symval.set_is_tls_symbol();
11388           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11389             symval.set_is_ifunc_symbol();
11390           psymval = &symval;
11391
11392           is_defined_in_discarded_section =
11393             (gsym->is_defined_in_discarded_section()
11394              && gsym->is_undefined());
11395           shndx = 0;
11396         }
11397
11398       Symbol_value<32> symval2;
11399       if (is_defined_in_discarded_section)
11400         {
11401           if (comdat_behavior == CB_UNDETERMINED)
11402             {
11403               std::string name = arm_object->section_name(relinfo->data_shndx);
11404               comdat_behavior = default_comdat_behavior.get(name.c_str());
11405             }
11406           if (comdat_behavior == CB_PRETEND)
11407             {
11408               // FIXME: This case does not work for global symbols.
11409               // We have no place to store the original section index.
11410               // Fortunately this does not matter for comdat sections,
11411               // only for sections explicitly discarded by a linker
11412               // script.
11413               bool found;
11414               typename elfcpp::Elf_types<32>::Elf_Addr value =
11415                 arm_object->map_to_kept_section(shndx, &found);
11416               if (found)
11417                 symval2.set_output_value(value + psymval->input_value());
11418               else
11419                 symval2.set_output_value(0);
11420             }
11421           else
11422             {
11423               if (comdat_behavior == CB_WARNING)
11424                 gold_warning_at_location(relinfo, i, offset,
11425                                          _("relocation refers to discarded "
11426                                            "section"));
11427               symval2.set_output_value(0);
11428             }
11429           symval2.set_no_output_symtab_entry();
11430           psymval = &symval2;
11431         }
11432
11433       // If symbol is a section symbol, we don't know the actual type of
11434       // destination.  Give up.
11435       if (psymval->is_section_symbol())
11436         continue;
11437
11438       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11439                                 addend, view_address + offset);
11440     }
11441 }
11442
11443 // Scan an input section for stub generation.
11444
11445 template<bool big_endian>
11446 void
11447 Target_arm<big_endian>::scan_section_for_stubs(
11448     const Relocate_info<32, big_endian>* relinfo,
11449     unsigned int sh_type,
11450     const unsigned char* prelocs,
11451     size_t reloc_count,
11452     Output_section* output_section,
11453     bool needs_special_offset_handling,
11454     const unsigned char* view,
11455     Arm_address view_address,
11456     section_size_type view_size)
11457 {
11458   if (sh_type == elfcpp::SHT_REL)
11459     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11460         relinfo,
11461         prelocs,
11462         reloc_count,
11463         output_section,
11464         needs_special_offset_handling,
11465         view,
11466         view_address,
11467         view_size);
11468   else if (sh_type == elfcpp::SHT_RELA)
11469     // We do not support RELA type relocations yet.  This is provided for
11470     // completeness.
11471     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11472         relinfo,
11473         prelocs,
11474         reloc_count,
11475         output_section,
11476         needs_special_offset_handling,
11477         view,
11478         view_address,
11479         view_size);
11480   else
11481     gold_unreachable();
11482 }
11483
11484 // Group input sections for stub generation.
11485 //
11486 // We group input sections in an output section so that the total size,
11487 // including any padding space due to alignment is smaller than GROUP_SIZE
11488 // unless the only input section in group is bigger than GROUP_SIZE already.
11489 // Then an ARM stub table is created to follow the last input section
11490 // in group.  For each group an ARM stub table is created an is placed
11491 // after the last group.  If STUB_ALWAYS_AFTER_BRANCH is false, we further
11492 // extend the group after the stub table.
11493
11494 template<bool big_endian>
11495 void
11496 Target_arm<big_endian>::group_sections(
11497     Layout* layout,
11498     section_size_type group_size,
11499     bool stubs_always_after_branch,
11500     const Task* task)
11501 {
11502   // Group input sections and insert stub table
11503   Layout::Section_list section_list;
11504   layout->get_executable_sections(&section_list);
11505   for (Layout::Section_list::const_iterator p = section_list.begin();
11506        p != section_list.end();
11507        ++p)
11508     {
11509       Arm_output_section<big_endian>* output_section =
11510         Arm_output_section<big_endian>::as_arm_output_section(*p);
11511       output_section->group_sections(group_size, stubs_always_after_branch,
11512                                      this, task);
11513     }
11514 }
11515
11516 // Relaxation hook.  This is where we do stub generation.
11517
11518 template<bool big_endian>
11519 bool
11520 Target_arm<big_endian>::do_relax(
11521     int pass,
11522     const Input_objects* input_objects,
11523     Symbol_table* symtab,
11524     Layout* layout,
11525     const Task* task)
11526 {
11527   // No need to generate stubs if this is a relocatable link.
11528   gold_assert(!parameters->options().relocatable());
11529
11530   // If this is the first pass, we need to group input sections into
11531   // stub groups.
11532   bool done_exidx_fixup = false;
11533   typedef typename Stub_table_list::iterator Stub_table_iterator;
11534   if (pass == 1)
11535     {
11536       // Determine the stub group size.  The group size is the absolute
11537       // value of the parameter --stub-group-size.  If --stub-group-size
11538       // is passed a negative value, we restrict stubs to be always after
11539       // the stubbed branches.
11540       int32_t stub_group_size_param =
11541         parameters->options().stub_group_size();
11542       bool stubs_always_after_branch = stub_group_size_param < 0;
11543       section_size_type stub_group_size = abs(stub_group_size_param);
11544
11545       if (stub_group_size == 1)
11546         {
11547           // Default value.
11548           // Thumb branch range is +-4MB has to be used as the default
11549           // maximum size (a given section can contain both ARM and Thumb
11550           // code, so the worst case has to be taken into account).  If we are
11551           // fixing cortex-a8 errata, the branch range has to be even smaller,
11552           // since wide conditional branch has a range of +-1MB only.
11553           //
11554           // This value is 48K less than that, which allows for 4096
11555           // 12-byte stubs.  If we exceed that, then we will fail to link.
11556           // The user will have to relink with an explicit group size
11557           // option.
11558             stub_group_size = 4145152;
11559         }
11560
11561       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11562       // page as the first half of a 32-bit branch straddling two 4K pages.
11563       // This is a crude way of enforcing that.  In addition, long conditional
11564       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11565       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11566       // cortex-A8 stubs from long conditional branches.
11567       if (this->fix_cortex_a8_)
11568         {
11569           stubs_always_after_branch = true;
11570           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11571           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11572         }
11573
11574       group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11575
11576       // Also fix .ARM.exidx section coverage.
11577       Arm_output_section<big_endian>* exidx_output_section = NULL;
11578       for (Layout::Section_list::const_iterator p =
11579              layout->section_list().begin();
11580            p != layout->section_list().end();
11581            ++p)
11582         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11583           {
11584             if (exidx_output_section == NULL)
11585               exidx_output_section =
11586                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11587             else
11588               // We cannot handle this now.
11589               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11590                            "non-relocatable link"),
11591                           exidx_output_section->name(),
11592                           (*p)->name());
11593           }
11594
11595       if (exidx_output_section != NULL)
11596         {
11597           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11598                                    symtab, task);
11599           done_exidx_fixup = true;
11600         }
11601     }
11602   else
11603     {
11604       // If this is not the first pass, addresses and file offsets have
11605       // been reset at this point, set them here.
11606       for (Stub_table_iterator sp = this->stub_tables_.begin();
11607            sp != this->stub_tables_.end();
11608            ++sp)
11609         {
11610           Arm_input_section<big_endian>* owner = (*sp)->owner();
11611           off_t off = align_address(owner->original_size(),
11612                                     (*sp)->addralign());
11613           (*sp)->set_address_and_file_offset(owner->address() + off,
11614                                              owner->offset() + off);
11615         }
11616     }
11617
11618   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11619   // beginning of each relaxation pass, just blow away all the stubs.
11620   // Alternatively, we could selectively remove only the stubs and reloc
11621   // information for code sections that have moved since the last pass.
11622   // That would require more book-keeping.
11623   if (this->fix_cortex_a8_)
11624     {
11625       // Clear all Cortex-A8 reloc information.
11626       for (typename Cortex_a8_relocs_info::const_iterator p =
11627              this->cortex_a8_relocs_info_.begin();
11628            p != this->cortex_a8_relocs_info_.end();
11629            ++p)
11630         delete p->second;
11631       this->cortex_a8_relocs_info_.clear();
11632
11633       // Remove all Cortex-A8 stubs.
11634       for (Stub_table_iterator sp = this->stub_tables_.begin();
11635            sp != this->stub_tables_.end();
11636            ++sp)
11637         (*sp)->remove_all_cortex_a8_stubs();
11638     }
11639
11640   // Scan relocs for relocation stubs
11641   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11642        op != input_objects->relobj_end();
11643        ++op)
11644     {
11645       Arm_relobj<big_endian>* arm_relobj =
11646         Arm_relobj<big_endian>::as_arm_relobj(*op);
11647       // Lock the object so we can read from it.  This is only called
11648       // single-threaded from Layout::finalize, so it is OK to lock.
11649       Task_lock_obj<Object> tl(task, arm_relobj);
11650       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11651     }
11652
11653   // Check all stub tables to see if any of them have their data sizes
11654   // or addresses alignments changed.  These are the only things that
11655   // matter.
11656   bool any_stub_table_changed = false;
11657   Unordered_set<const Output_section*> sections_needing_adjustment;
11658   for (Stub_table_iterator sp = this->stub_tables_.begin();
11659        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11660        ++sp)
11661     {
11662       if ((*sp)->update_data_size_and_addralign())
11663         {
11664           // Update data size of stub table owner.
11665           Arm_input_section<big_endian>* owner = (*sp)->owner();
11666           uint64_t address = owner->address();
11667           off_t offset = owner->offset();
11668           owner->reset_address_and_file_offset();
11669           owner->set_address_and_file_offset(address, offset);
11670
11671           sections_needing_adjustment.insert(owner->output_section());
11672           any_stub_table_changed = true;
11673         }
11674     }
11675
11676   // Output_section_data::output_section() returns a const pointer but we
11677   // need to update output sections, so we record all output sections needing
11678   // update above and scan the sections here to find out what sections need
11679   // to be updated.
11680   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11681       p != layout->section_list().end();
11682       ++p)
11683     {
11684       if (sections_needing_adjustment.find(*p)
11685           != sections_needing_adjustment.end())
11686         (*p)->set_section_offsets_need_adjustment();
11687     }
11688
11689   // Stop relaxation if no EXIDX fix-up and no stub table change.
11690   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11691
11692   // Finalize the stubs in the last relaxation pass.
11693   if (!continue_relaxation)
11694     {
11695       for (Stub_table_iterator sp = this->stub_tables_.begin();
11696            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11697             ++sp)
11698         (*sp)->finalize_stubs();
11699
11700       // Update output local symbol counts of objects if necessary.
11701       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11702            op != input_objects->relobj_end();
11703            ++op)
11704         {
11705           Arm_relobj<big_endian>* arm_relobj =
11706             Arm_relobj<big_endian>::as_arm_relobj(*op);
11707
11708           // Update output local symbol counts.  We need to discard local
11709           // symbols defined in parts of input sections that are discarded by
11710           // relaxation.
11711           if (arm_relobj->output_local_symbol_count_needs_update())
11712             {
11713               // We need to lock the object's file to update it.
11714               Task_lock_obj<Object> tl(task, arm_relobj);
11715               arm_relobj->update_output_local_symbol_count();
11716             }
11717         }
11718     }
11719
11720   return continue_relaxation;
11721 }
11722
11723 // Relocate a stub.
11724
11725 template<bool big_endian>
11726 void
11727 Target_arm<big_endian>::relocate_stub(
11728     Stub* stub,
11729     const Relocate_info<32, big_endian>* relinfo,
11730     Output_section* output_section,
11731     unsigned char* view,
11732     Arm_address address,
11733     section_size_type view_size)
11734 {
11735   Relocate relocate;
11736   const Stub_template* stub_template = stub->stub_template();
11737   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11738     {
11739       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11740       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11741
11742       unsigned int r_type = insn->r_type();
11743       section_size_type reloc_offset = stub_template->reloc_offset(i);
11744       section_size_type reloc_size = insn->size();
11745       gold_assert(reloc_offset + reloc_size <= view_size);
11746
11747       // This is the address of the stub destination.
11748       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11749       Symbol_value<32> symval;
11750       symval.set_output_value(target);
11751
11752       // Synthesize a fake reloc just in case.  We don't have a symbol so
11753       // we use 0.
11754       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11755       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11756       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11757       reloc_write.put_r_offset(reloc_offset);
11758       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11759       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11760
11761       relocate.relocate(relinfo, this, output_section,
11762                         this->fake_relnum_for_stubs, rel, r_type,
11763                         NULL, &symval, view + reloc_offset,
11764                         address + reloc_offset, reloc_size);
11765     }
11766 }
11767
11768 // Determine whether an object attribute tag takes an integer, a
11769 // string or both.
11770
11771 template<bool big_endian>
11772 int
11773 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11774 {
11775   if (tag == Object_attribute::Tag_compatibility)
11776     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11777             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11778   else if (tag == elfcpp::Tag_nodefaults)
11779     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11780             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11781   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11782     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11783   else if (tag < 32)
11784     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11785   else
11786     return ((tag & 1) != 0
11787             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11788             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11789 }
11790
11791 // Reorder attributes.
11792 //
11793 // The ABI defines that Tag_conformance should be emitted first, and that
11794 // Tag_nodefaults should be second (if either is defined).  This sets those
11795 // two positions, and bumps up the position of all the remaining tags to
11796 // compensate.
11797
11798 template<bool big_endian>
11799 int
11800 Target_arm<big_endian>::do_attributes_order(int num) const
11801 {
11802   // Reorder the known object attributes in output.  We want to move
11803   // Tag_conformance to position 4 and Tag_conformance to position 5
11804   // and shift everything between 4 .. Tag_conformance - 1 to make room.
11805   if (num == 4)
11806     return elfcpp::Tag_conformance;
11807   if (num == 5)
11808     return elfcpp::Tag_nodefaults;
11809   if ((num - 2) < elfcpp::Tag_nodefaults)
11810     return num - 2;
11811   if ((num - 1) < elfcpp::Tag_conformance)
11812     return num - 1;
11813   return num;
11814 }
11815
11816 // Scan a span of THUMB code for Cortex-A8 erratum.
11817
11818 template<bool big_endian>
11819 void
11820 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11821     Arm_relobj<big_endian>* arm_relobj,
11822     unsigned int shndx,
11823     section_size_type span_start,
11824     section_size_type span_end,
11825     const unsigned char* view,
11826     Arm_address address)
11827 {
11828   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11829   //
11830   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11831   // The branch target is in the same 4KB region as the
11832   // first half of the branch.
11833   // The instruction before the branch is a 32-bit
11834   // length non-branch instruction.
11835   section_size_type i = span_start;
11836   bool last_was_32bit = false;
11837   bool last_was_branch = false;
11838   while (i < span_end)
11839     {
11840       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11841       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11842       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11843       bool is_blx = false, is_b = false;
11844       bool is_bl = false, is_bcc = false;
11845
11846       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11847       if (insn_32bit)
11848         {
11849           // Load the rest of the insn (in manual-friendly order).
11850           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11851
11852           // Encoding T4: B<c>.W.
11853           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11854           // Encoding T1: BL<c>.W.
11855           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11856           // Encoding T2: BLX<c>.W.
11857           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11858           // Encoding T3: B<c>.W (not permitted in IT block).
11859           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11860                     && (insn & 0x07f00000U) != 0x03800000U);
11861         }
11862
11863       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11864
11865       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11866       // page boundary and it follows 32-bit non-branch instruction,
11867       // we need to work around.
11868       if (is_32bit_branch
11869           && ((address + i) & 0xfffU) == 0xffeU
11870           && last_was_32bit
11871           && !last_was_branch)
11872         {
11873           // Check to see if there is a relocation stub for this branch.
11874           bool force_target_arm = false;
11875           bool force_target_thumb = false;
11876           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11877           Cortex_a8_relocs_info::const_iterator p =
11878             this->cortex_a8_relocs_info_.find(address + i);
11879
11880           if (p != this->cortex_a8_relocs_info_.end())
11881             {
11882               cortex_a8_reloc = p->second;
11883               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11884
11885               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11886                   && !target_is_thumb)
11887                 force_target_arm = true;
11888               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11889                        && target_is_thumb)
11890                 force_target_thumb = true;
11891             }
11892
11893           off_t offset;
11894           Stub_type stub_type = arm_stub_none;
11895
11896           // Check if we have an offending branch instruction.
11897           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11898           uint16_t lower_insn = insn & 0xffffU;
11899           typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11900
11901           if (cortex_a8_reloc != NULL
11902               && cortex_a8_reloc->reloc_stub() != NULL)
11903             // We've already made a stub for this instruction, e.g.
11904             // it's a long branch or a Thumb->ARM stub.  Assume that
11905             // stub will suffice to work around the A8 erratum (see
11906             // setting of always_after_branch above).
11907             ;
11908           else if (is_bcc)
11909             {
11910               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11911                                                               lower_insn);
11912               stub_type = arm_stub_a8_veneer_b_cond;
11913             }
11914           else if (is_b || is_bl || is_blx)
11915             {
11916               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11917                                                          lower_insn);
11918               if (is_blx)
11919                 offset &= ~3;
11920
11921               stub_type = (is_blx
11922                            ? arm_stub_a8_veneer_blx
11923                            : (is_bl
11924                               ? arm_stub_a8_veneer_bl
11925                               : arm_stub_a8_veneer_b));
11926             }
11927
11928           if (stub_type != arm_stub_none)
11929             {
11930               Arm_address pc_for_insn = address + i + 4;
11931
11932               // The original instruction is a BL, but the target is
11933               // an ARM instruction.  If we were not making a stub,
11934               // the BL would have been converted to a BLX.  Use the
11935               // BLX stub instead in that case.
11936               if (this->may_use_v5t_interworking() && force_target_arm
11937                   && stub_type == arm_stub_a8_veneer_bl)
11938                 {
11939                   stub_type = arm_stub_a8_veneer_blx;
11940                   is_blx = true;
11941                   is_bl = false;
11942                 }
11943               // Conversely, if the original instruction was
11944               // BLX but the target is Thumb mode, use the BL stub.
11945               else if (force_target_thumb
11946                        && stub_type == arm_stub_a8_veneer_blx)
11947                 {
11948                   stub_type = arm_stub_a8_veneer_bl;
11949                   is_blx = false;
11950                   is_bl = true;
11951                 }
11952
11953               if (is_blx)
11954                 pc_for_insn &= ~3;
11955
11956               // If we found a relocation, use the proper destination,
11957               // not the offset in the (unrelocated) instruction.
11958               // Note this is always done if we switched the stub type above.
11959               if (cortex_a8_reloc != NULL)
11960                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11961
11962               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11963
11964               // Add a new stub if destination address in in the same page.
11965               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11966                 {
11967                   Cortex_a8_stub* stub =
11968                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11969                                                             arm_relobj, shndx,
11970                                                             address + i,
11971                                                             target, insn);
11972                   Stub_table<big_endian>* stub_table =
11973                     arm_relobj->stub_table(shndx);
11974                   gold_assert(stub_table != NULL);
11975                   stub_table->add_cortex_a8_stub(address + i, stub);
11976                 }
11977             }
11978         }
11979
11980       i += insn_32bit ? 4 : 2;
11981       last_was_32bit = insn_32bit;
11982       last_was_branch = is_32bit_branch;
11983     }
11984 }
11985
11986 // Apply the Cortex-A8 workaround.
11987
11988 template<bool big_endian>
11989 void
11990 Target_arm<big_endian>::apply_cortex_a8_workaround(
11991     const Cortex_a8_stub* stub,
11992     Arm_address stub_address,
11993     unsigned char* insn_view,
11994     Arm_address insn_address)
11995 {
11996   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11997   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11998   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11999   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12000   off_t branch_offset = stub_address - (insn_address + 4);
12001
12002   typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12003   switch (stub->stub_template()->type())
12004     {
12005     case arm_stub_a8_veneer_b_cond:
12006       // For a conditional branch, we re-write it to be an unconditional
12007       // branch to the stub.  We use the THUMB-2 encoding here.
12008       upper_insn = 0xf000U;
12009       lower_insn = 0xb800U;
12010       // Fall through
12011     case arm_stub_a8_veneer_b:
12012     case arm_stub_a8_veneer_bl:
12013     case arm_stub_a8_veneer_blx:
12014       if ((lower_insn & 0x5000U) == 0x4000U)
12015         // For a BLX instruction, make sure that the relocation is
12016         // rounded up to a word boundary.  This follows the semantics of
12017         // the instruction which specifies that bit 1 of the target
12018         // address will come from bit 1 of the base address.
12019         branch_offset = (branch_offset + 2) & ~3;
12020
12021       // Put BRANCH_OFFSET back into the insn.
12022       gold_assert(!Bits<25>::has_overflow32(branch_offset));
12023       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12024       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12025       break;
12026
12027     default:
12028       gold_unreachable();
12029     }
12030
12031   // Put the relocated value back in the object file:
12032   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12033   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12034 }
12035
12036 // Target selector for ARM.  Note this is never instantiated directly.
12037 // It's only used in Target_selector_arm_nacl, below.
12038
12039 template<bool big_endian>
12040 class Target_selector_arm : public Target_selector
12041 {
12042  public:
12043   Target_selector_arm()
12044     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12045                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12046                       (big_endian ? "armelfb" : "armelf"))
12047   { }
12048
12049   Target*
12050   do_instantiate_target()
12051   { return new Target_arm<big_endian>(); }
12052 };
12053
12054 // Fix .ARM.exidx section coverage.
12055
12056 template<bool big_endian>
12057 void
12058 Target_arm<big_endian>::fix_exidx_coverage(
12059     Layout* layout,
12060     const Input_objects* input_objects,
12061     Arm_output_section<big_endian>* exidx_section,
12062     Symbol_table* symtab,
12063     const Task* task)
12064 {
12065   // We need to look at all the input sections in output in ascending
12066   // order of of output address.  We do that by building a sorted list
12067   // of output sections by addresses.  Then we looks at the output sections
12068   // in order.  The input sections in an output section are already sorted
12069   // by addresses within the output section.
12070
12071   typedef std::set<Output_section*, output_section_address_less_than>
12072       Sorted_output_section_list;
12073   Sorted_output_section_list sorted_output_sections;
12074
12075   // Find out all the output sections of input sections pointed by
12076   // EXIDX input sections.
12077   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12078        p != input_objects->relobj_end();
12079        ++p)
12080     {
12081       Arm_relobj<big_endian>* arm_relobj =
12082         Arm_relobj<big_endian>::as_arm_relobj(*p);
12083       std::vector<unsigned int> shndx_list;
12084       arm_relobj->get_exidx_shndx_list(&shndx_list);
12085       for (size_t i = 0; i < shndx_list.size(); ++i)
12086         {
12087           const Arm_exidx_input_section* exidx_input_section =
12088             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12089           gold_assert(exidx_input_section != NULL);
12090           if (!exidx_input_section->has_errors())
12091             {
12092               unsigned int text_shndx = exidx_input_section->link();
12093               Output_section* os = arm_relobj->output_section(text_shndx);
12094               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12095                 sorted_output_sections.insert(os);
12096             }
12097         }
12098     }
12099
12100   // Go over the output sections in ascending order of output addresses.
12101   typedef typename Arm_output_section<big_endian>::Text_section_list
12102       Text_section_list;
12103   Text_section_list sorted_text_sections;
12104   for (typename Sorted_output_section_list::iterator p =
12105         sorted_output_sections.begin();
12106       p != sorted_output_sections.end();
12107       ++p)
12108     {
12109       Arm_output_section<big_endian>* arm_output_section =
12110         Arm_output_section<big_endian>::as_arm_output_section(*p);
12111       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12112     }
12113
12114   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12115                                     merge_exidx_entries(), task);
12116 }
12117
12118 template<bool big_endian>
12119 void
12120 Target_arm<big_endian>::do_define_standard_symbols(
12121     Symbol_table* symtab,
12122     Layout* layout)
12123 {
12124   // Handle the .ARM.exidx section.
12125   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12126
12127   if (exidx_section != NULL)
12128     {
12129       // Create __exidx_start and __exidx_end symbols.
12130       symtab->define_in_output_data("__exidx_start",
12131                                     NULL, // version
12132                                     Symbol_table::PREDEFINED,
12133                                     exidx_section,
12134                                     0, // value
12135                                     0, // symsize
12136                                     elfcpp::STT_NOTYPE,
12137                                     elfcpp::STB_GLOBAL,
12138                                     elfcpp::STV_HIDDEN,
12139                                     0, // nonvis
12140                                     false, // offset_is_from_end
12141                                     true); // only_if_ref
12142
12143       symtab->define_in_output_data("__exidx_end",
12144                                     NULL, // version
12145                                     Symbol_table::PREDEFINED,
12146                                     exidx_section,
12147                                     0, // value
12148                                     0, // symsize
12149                                     elfcpp::STT_NOTYPE,
12150                                     elfcpp::STB_GLOBAL,
12151                                     elfcpp::STV_HIDDEN,
12152                                     0, // nonvis
12153                                     true, // offset_is_from_end
12154                                     true); // only_if_ref
12155     }
12156   else
12157     {
12158       // Define __exidx_start and __exidx_end even when .ARM.exidx
12159       // section is missing to match ld's behaviour.
12160       symtab->define_as_constant("__exidx_start", NULL,
12161                                  Symbol_table::PREDEFINED,
12162                                  0, 0, elfcpp::STT_OBJECT,
12163                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12164                                  true, false);
12165       symtab->define_as_constant("__exidx_end", NULL,
12166                                  Symbol_table::PREDEFINED,
12167                                  0, 0, elfcpp::STT_OBJECT,
12168                                  elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12169                                  true, false);
12170     }
12171 }
12172
12173 // NaCl variant.  It uses different PLT contents.
12174
12175 template<bool big_endian>
12176 class Output_data_plt_arm_nacl;
12177
12178 template<bool big_endian>
12179 class Target_arm_nacl : public Target_arm<big_endian>
12180 {
12181  public:
12182   Target_arm_nacl()
12183     : Target_arm<big_endian>(&arm_nacl_info)
12184   { }
12185
12186  protected:
12187   virtual Output_data_plt_arm<big_endian>*
12188   do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12189   { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12190
12191  private:
12192   static const Target::Target_info arm_nacl_info;
12193 };
12194
12195 template<bool big_endian>
12196 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12197 {
12198   32,                   // size
12199   big_endian,           // is_big_endian
12200   elfcpp::EM_ARM,       // machine_code
12201   false,                // has_make_symbol
12202   false,                // has_resolve
12203   false,                // has_code_fill
12204   true,                 // is_default_stack_executable
12205   false,                // can_icf_inline_merge_sections
12206   '\0',                 // wrap_char
12207   "/lib/ld-nacl-arm.so.1", // dynamic_linker
12208   0x20000,              // default_text_segment_address
12209   0x10000,              // abi_pagesize (overridable by -z max-page-size)
12210   0x10000,              // common_pagesize (overridable by -z common-page-size)
12211   true,                 // isolate_execinstr
12212   0x10000000,           // rosegment_gap
12213   elfcpp::SHN_UNDEF,    // small_common_shndx
12214   elfcpp::SHN_UNDEF,    // large_common_shndx
12215   0,                    // small_common_section_flags
12216   0,                    // large_common_section_flags
12217   ".ARM.attributes",    // attributes_section
12218   "aeabi",              // attributes_vendor
12219   "_start"              // entry_symbol_name
12220 };
12221
12222 template<bool big_endian>
12223 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12224 {
12225  public:
12226   Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12227     : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12228   { }
12229
12230  protected:
12231   // Return the offset of the first non-reserved PLT entry.
12232   virtual unsigned int
12233   do_first_plt_entry_offset() const
12234   { return sizeof(first_plt_entry); }
12235
12236   // Return the size of a PLT entry.
12237   virtual unsigned int
12238   do_get_plt_entry_size() const
12239   { return sizeof(plt_entry); }
12240
12241   virtual void
12242   do_fill_first_plt_entry(unsigned char* pov,
12243                           Arm_address got_address,
12244                           Arm_address plt_address);
12245
12246   virtual void
12247   do_fill_plt_entry(unsigned char* pov,
12248                     Arm_address got_address,
12249                     Arm_address plt_address,
12250                     unsigned int got_offset,
12251                     unsigned int plt_offset);
12252
12253  private:
12254   inline uint32_t arm_movw_immediate(uint32_t value)
12255   {
12256     return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12257   }
12258
12259   inline uint32_t arm_movt_immediate(uint32_t value)
12260   {
12261     return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12262   }
12263
12264   // Template for the first PLT entry.
12265   static const uint32_t first_plt_entry[16];
12266
12267   // Template for subsequent PLT entries.
12268   static const uint32_t plt_entry[4];
12269 };
12270
12271 // The first entry in the PLT.
12272 template<bool big_endian>
12273 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12274 {
12275   // First bundle:
12276   0xe300c000,                           // movw ip, #:lower16:&GOT[2]-.+8
12277   0xe340c000,                           // movt ip, #:upper16:&GOT[2]-.+8
12278   0xe08cc00f,                           // add  ip, ip, pc
12279   0xe52dc008,                           // str  ip, [sp, #-8]!
12280   // Second bundle:
12281   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12282   0xe59cc000,                           // ldr  ip, [ip]
12283   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12284   0xe12fff1c,                           // bx   ip
12285   // Third bundle:
12286   0xe320f000,                           // nop
12287   0xe320f000,                           // nop
12288   0xe320f000,                           // nop
12289   // .Lplt_tail:
12290   0xe50dc004,                           // str  ip, [sp, #-4]
12291   // Fourth bundle:
12292   0xe3ccc103,                           // bic  ip, ip, #0xc0000000
12293   0xe59cc000,                           // ldr  ip, [ip]
12294   0xe3ccc13f,                           // bic  ip, ip, #0xc000000f
12295   0xe12fff1c,                           // bx   ip
12296 };
12297
12298 template<bool big_endian>
12299 void
12300 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12301     unsigned char* pov,
12302     Arm_address got_address,
12303     Arm_address plt_address)
12304 {
12305   // Write first PLT entry.  All but first two words are constants.
12306   const size_t num_first_plt_words = (sizeof(first_plt_entry)
12307                                       / sizeof(first_plt_entry[0]));
12308
12309   int32_t got_displacement = got_address + 8 - (plt_address + 16);
12310
12311   elfcpp::Swap<32, big_endian>::writeval
12312     (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12313   elfcpp::Swap<32, big_endian>::writeval
12314     (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12315
12316   for (size_t i = 2; i < num_first_plt_words; ++i)
12317     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12318 }
12319
12320 // Subsequent entries in the PLT.
12321
12322 template<bool big_endian>
12323 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12324 {
12325   0xe300c000,                           // movw ip, #:lower16:&GOT[n]-.+8
12326   0xe340c000,                           // movt ip, #:upper16:&GOT[n]-.+8
12327   0xe08cc00f,                           // add  ip, ip, pc
12328   0xea000000,                           // b    .Lplt_tail
12329 };
12330
12331 template<bool big_endian>
12332 void
12333 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12334     unsigned char* pov,
12335     Arm_address got_address,
12336     Arm_address plt_address,
12337     unsigned int got_offset,
12338     unsigned int plt_offset)
12339 {
12340   // Calculate the displacement between the PLT slot and the
12341   // common tail that's part of the special initial PLT slot.
12342   int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12343                                - (plt_address + plt_offset
12344                                   + sizeof(plt_entry) + sizeof(uint32_t)));
12345   gold_assert((tail_displacement & 3) == 0);
12346   tail_displacement >>= 2;
12347
12348   gold_assert ((tail_displacement & 0xff000000) == 0
12349                || (-tail_displacement & 0xff000000) == 0);
12350
12351   // Calculate the displacement between the PLT slot and the entry
12352   // in the GOT.  The offset accounts for the value produced by
12353   // adding to pc in the penultimate instruction of the PLT stub.
12354   const int32_t got_displacement = (got_address + got_offset
12355                                     - (plt_address + sizeof(plt_entry)));
12356
12357   elfcpp::Swap<32, big_endian>::writeval
12358     (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12359   elfcpp::Swap<32, big_endian>::writeval
12360     (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12361   elfcpp::Swap<32, big_endian>::writeval
12362     (pov + 8, plt_entry[2]);
12363   elfcpp::Swap<32, big_endian>::writeval
12364     (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12365 }
12366
12367 // Target selectors.
12368
12369 template<bool big_endian>
12370 class Target_selector_arm_nacl
12371   : public Target_selector_nacl<Target_selector_arm<big_endian>,
12372                                 Target_arm_nacl<big_endian> >
12373 {
12374  public:
12375   Target_selector_arm_nacl()
12376     : Target_selector_nacl<Target_selector_arm<big_endian>,
12377                            Target_arm_nacl<big_endian> >(
12378           "arm",
12379           big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12380           big_endian ? "armelfb_nacl" : "armelf_nacl")
12381   { }
12382 };
12383
12384 Target_selector_arm_nacl<false> target_selector_arm;
12385 Target_selector_arm_nacl<true> target_selector_armbe;
12386
12387 } // End anonymous namespace.