Merge branch 'vendor/EXPAT'
[dragonfly.git] / contrib / binutils-2.21 / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010 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
55 namespace
56 {
57
58 using namespace gold;
59
60 template<bool big_endian>
61 class Output_data_plt_arm;
62
63 template<bool big_endian>
64 class Stub_table;
65
66 template<bool big_endian>
67 class Arm_input_section;
68
69 class Arm_exidx_cantunwind;
70
71 class Arm_exidx_merged_section;
72
73 class Arm_exidx_fixup;
74
75 template<bool big_endian>
76 class Arm_output_section;
77
78 class Arm_exidx_input_section;
79
80 template<bool big_endian>
81 class Arm_relobj;
82
83 template<bool big_endian>
84 class Arm_relocate_functions;
85
86 template<bool big_endian>
87 class Arm_output_data_got;
88
89 template<bool big_endian>
90 class Target_arm;
91
92 // For convenience.
93 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
94
95 // Maximum branch offsets for ARM, THUMB and THUMB2.
96 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
97 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
98 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
99 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
100 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
101 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
102
103 // Thread Control Block size.
104 const size_t ARM_TCB_SIZE = 8;
105
106 // The arm target class.
107 //
108 // This is a very simple port of gold for ARM-EABI.  It is intended for
109 // supporting Android only for the time being.
110 // 
111 // TODOs:
112 // - Implement all static relocation types documented in arm-reloc.def.
113 // - Make PLTs more flexible for different architecture features like
114 //   Thumb-2 and BE8.
115 // There are probably a lot more.
116
117 // Ideally we would like to avoid using global variables but this is used
118 // very in many places and sometimes in loops.  If we use a function
119 // returning a static instance of Arm_reloc_property_table, it will very
120 // slow in an threaded environment since the static instance needs to be
121 // locked.  The pointer is below initialized in the
122 // Target::do_select_as_default_target() hook so that we do not spend time
123 // building the table if we are not linking ARM objects.
124 //
125 // An alternative is to to process the information in arm-reloc.def in
126 // compilation time and generate a representation of it in PODs only.  That
127 // way we can avoid initialization when the linker starts.
128
129 Arm_reloc_property_table* arm_reloc_property_table = NULL;
130
131 // Instruction template class.  This class is similar to the insn_sequence
132 // struct in bfd/elf32-arm.c.
133
134 class Insn_template
135 {
136  public:
137   // Types of instruction templates.
138   enum Type
139     {
140       THUMB16_TYPE = 1,
141       // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction 
142       // templates with class-specific semantics.  Currently this is used
143       // only by the Cortex_a8_stub class for handling condition codes in
144       // conditional branches.
145       THUMB16_SPECIAL_TYPE,
146       THUMB32_TYPE,
147       ARM_TYPE,
148       DATA_TYPE
149     };
150
151   // Factory methods to create instruction templates in different formats.
152
153   static const Insn_template
154   thumb16_insn(uint32_t data)
155   { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); } 
156
157   // A Thumb conditional branch, in which the proper condition is inserted
158   // when we build the stub.
159   static const Insn_template
160   thumb16_bcond_insn(uint32_t data)
161   { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); } 
162
163   static const Insn_template
164   thumb32_insn(uint32_t data)
165   { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); } 
166
167   static const Insn_template
168   thumb32_b_insn(uint32_t data, int reloc_addend)
169   {
170     return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
171                          reloc_addend);
172   } 
173
174   static const Insn_template
175   arm_insn(uint32_t data)
176   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
177
178   static const Insn_template
179   arm_rel_insn(unsigned data, int reloc_addend)
180   { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
181
182   static const Insn_template
183   data_word(unsigned data, unsigned int r_type, int reloc_addend)
184   { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); } 
185
186   // Accessors.  This class is used for read-only objects so no modifiers
187   // are provided.
188
189   uint32_t
190   data() const
191   { return this->data_; }
192
193   // Return the instruction sequence type of this.
194   Type
195   type() const
196   { return this->type_; }
197
198   // Return the ARM relocation type of this.
199   unsigned int
200   r_type() const
201   { return this->r_type_; }
202
203   int32_t
204   reloc_addend() const
205   { return this->reloc_addend_; }
206
207   // Return size of instruction template in bytes.
208   size_t
209   size() const;
210
211   // Return byte-alignment of instruction template.
212   unsigned
213   alignment() const;
214
215  private:
216   // We make the constructor private to ensure that only the factory
217   // methods are used.
218   inline
219   Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
220     : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
221   { }
222
223   // Instruction specific data.  This is used to store information like
224   // some of the instruction bits.
225   uint32_t data_;
226   // Instruction template type.
227   Type type_;
228   // Relocation type if there is a relocation or R_ARM_NONE otherwise.
229   unsigned int r_type_;
230   // Relocation addend.
231   int32_t reloc_addend_;
232 };
233
234 // Macro for generating code to stub types. One entry per long/short
235 // branch stub
236
237 #define DEF_STUBS \
238   DEF_STUB(long_branch_any_any) \
239   DEF_STUB(long_branch_v4t_arm_thumb) \
240   DEF_STUB(long_branch_thumb_only) \
241   DEF_STUB(long_branch_v4t_thumb_thumb) \
242   DEF_STUB(long_branch_v4t_thumb_arm) \
243   DEF_STUB(short_branch_v4t_thumb_arm) \
244   DEF_STUB(long_branch_any_arm_pic) \
245   DEF_STUB(long_branch_any_thumb_pic) \
246   DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
247   DEF_STUB(long_branch_v4t_arm_thumb_pic) \
248   DEF_STUB(long_branch_v4t_thumb_arm_pic) \
249   DEF_STUB(long_branch_thumb_only_pic) \
250   DEF_STUB(a8_veneer_b_cond) \
251   DEF_STUB(a8_veneer_b) \
252   DEF_STUB(a8_veneer_bl) \
253   DEF_STUB(a8_veneer_blx) \
254   DEF_STUB(v4_veneer_bx)
255
256 // Stub types.
257
258 #define DEF_STUB(x) arm_stub_##x,
259 typedef enum
260   {
261     arm_stub_none,
262     DEF_STUBS
263
264     // First reloc stub type.
265     arm_stub_reloc_first = arm_stub_long_branch_any_any,
266     // Last  reloc stub type.
267     arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
268
269     // First Cortex-A8 stub type.
270     arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
271     // Last Cortex-A8 stub type.
272     arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
273     
274     // Last stub type.
275     arm_stub_type_last = arm_stub_v4_veneer_bx
276   } Stub_type;
277 #undef DEF_STUB
278
279 // Stub template class.  Templates are meant to be read-only objects.
280 // A stub template for a stub type contains all read-only attributes
281 // common to all stubs of the same type.
282
283 class Stub_template
284 {
285  public:
286   Stub_template(Stub_type, const Insn_template*, size_t);
287
288   ~Stub_template()
289   { }
290
291   // Return stub type.
292   Stub_type
293   type() const
294   { return this->type_; }
295
296   // Return an array of instruction templates.
297   const Insn_template*
298   insns() const
299   { return this->insns_; }
300
301   // Return size of template in number of instructions.
302   size_t
303   insn_count() const
304   { return this->insn_count_; }
305
306   // Return size of template in bytes.
307   size_t
308   size() const
309   { return this->size_; }
310
311   // Return alignment of the stub template.
312   unsigned
313   alignment() const
314   { return this->alignment_; }
315   
316   // Return whether entry point is in thumb mode.
317   bool
318   entry_in_thumb_mode() const
319   { return this->entry_in_thumb_mode_; }
320
321   // Return number of relocations in this template.
322   size_t
323   reloc_count() const
324   { return this->relocs_.size(); }
325
326   // Return index of the I-th instruction with relocation.
327   size_t
328   reloc_insn_index(size_t i) const
329   {
330     gold_assert(i < this->relocs_.size());
331     return this->relocs_[i].first;
332   }
333
334   // Return the offset of the I-th instruction with relocation from the
335   // beginning of the stub.
336   section_size_type
337   reloc_offset(size_t i) const
338   {
339     gold_assert(i < this->relocs_.size());
340     return this->relocs_[i].second;
341   }
342
343  private:
344   // This contains information about an instruction template with a relocation
345   // and its offset from start of stub.
346   typedef std::pair<size_t, section_size_type> Reloc;
347
348   // A Stub_template may not be copied.  We want to share templates as much
349   // as possible.
350   Stub_template(const Stub_template&);
351   Stub_template& operator=(const Stub_template&);
352   
353   // Stub type.
354   Stub_type type_;
355   // Points to an array of Insn_templates.
356   const Insn_template* insns_;
357   // Number of Insn_templates in insns_[].
358   size_t insn_count_;
359   // Size of templated instructions in bytes.
360   size_t size_;
361   // Alignment of templated instructions.
362   unsigned alignment_;
363   // Flag to indicate if entry is in thumb mode.
364   bool entry_in_thumb_mode_;
365   // A table of reloc instruction indices and offsets.  We can find these by
366   // looking at the instruction templates but we pre-compute and then stash
367   // them here for speed. 
368   std::vector<Reloc> relocs_;
369 };
370
371 //
372 // A class for code stubs.  This is a base class for different type of
373 // stubs used in the ARM target.
374 //
375
376 class Stub
377 {
378  private:
379   static const section_offset_type invalid_offset =
380     static_cast<section_offset_type>(-1);
381
382  public:
383   Stub(const Stub_template* stub_template)
384     : stub_template_(stub_template), offset_(invalid_offset)
385   { }
386
387   virtual
388    ~Stub()
389   { }
390
391   // Return the stub template.
392   const Stub_template*
393   stub_template() const
394   { return this->stub_template_; }
395
396   // Return offset of code stub from beginning of its containing stub table.
397   section_offset_type
398   offset() const
399   {
400     gold_assert(this->offset_ != invalid_offset);
401     return this->offset_;
402   }
403
404   // Set offset of code stub from beginning of its containing stub table.
405   void
406   set_offset(section_offset_type offset)
407   { this->offset_ = offset; }
408   
409   // Return the relocation target address of the i-th relocation in the
410   // stub.  This must be defined in a child class.
411   Arm_address
412   reloc_target(size_t i)
413   { return this->do_reloc_target(i); }
414
415   // Write a stub at output VIEW.  BIG_ENDIAN select how a stub is written.
416   void
417   write(unsigned char* view, section_size_type view_size, bool big_endian)
418   { this->do_write(view, view_size, big_endian); }
419
420   // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
421   // for the i-th instruction.
422   uint16_t
423   thumb16_special(size_t i)
424   { return this->do_thumb16_special(i); }
425
426  protected:
427   // This must be defined in the child class.
428   virtual Arm_address
429   do_reloc_target(size_t) = 0;
430
431   // This may be overridden in the child class.
432   virtual void
433   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
434   {
435     if (big_endian)
436       this->do_fixed_endian_write<true>(view, view_size);
437     else
438       this->do_fixed_endian_write<false>(view, view_size);
439   }
440   
441   // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
442   // instruction template.
443   virtual uint16_t
444   do_thumb16_special(size_t)
445   { gold_unreachable(); }
446
447  private:
448   // A template to implement do_write.
449   template<bool big_endian>
450   void inline
451   do_fixed_endian_write(unsigned char*, section_size_type);
452
453   // Its template.
454   const Stub_template* stub_template_;
455   // Offset within the section of containing this stub.
456   section_offset_type offset_;
457 };
458
459 // Reloc stub class.  These are stubs we use to fix up relocation because
460 // of limited branch ranges.
461
462 class Reloc_stub : public Stub
463 {
464  public:
465   static const unsigned int invalid_index = static_cast<unsigned int>(-1);
466   // We assume we never jump to this address.
467   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
468
469   // Return destination address.
470   Arm_address
471   destination_address() const
472   {
473     gold_assert(this->destination_address_ != this->invalid_address);
474     return this->destination_address_;
475   }
476
477   // Set destination address.
478   void
479   set_destination_address(Arm_address address)
480   {
481     gold_assert(address != this->invalid_address);
482     this->destination_address_ = address;
483   }
484
485   // Reset destination address.
486   void
487   reset_destination_address()
488   { this->destination_address_ = this->invalid_address; }
489
490   // Determine stub type for a branch of a relocation of R_TYPE going
491   // from BRANCH_ADDRESS to BRANCH_TARGET.  If TARGET_IS_THUMB is set,
492   // the branch target is a thumb instruction.  TARGET is used for look
493   // up ARM-specific linker settings.
494   static Stub_type
495   stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
496                       Arm_address branch_target, bool target_is_thumb);
497
498   // Reloc_stub key.  A key is logically a triplet of a stub type, a symbol
499   // and an addend.  Since we treat global and local symbol differently, we
500   // use a Symbol object for a global symbol and a object-index pair for
501   // a local symbol.
502   class Key
503   {
504    public:
505     // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
506     // R_SYM.  Otherwise, this is a local symbol and RELOBJ must non-NULL
507     // and R_SYM must not be invalid_index.
508     Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
509         unsigned int r_sym, int32_t addend)
510       : stub_type_(stub_type), addend_(addend)
511     {
512       if (symbol != NULL)
513         {
514           this->r_sym_ = Reloc_stub::invalid_index;
515           this->u_.symbol = symbol;
516         }
517       else
518         {
519           gold_assert(relobj != NULL && r_sym != invalid_index);
520           this->r_sym_ = r_sym;
521           this->u_.relobj = relobj;
522         }
523     }
524
525     ~Key()
526     { }
527
528     // Accessors: Keys are meant to be read-only object so no modifiers are
529     // provided.
530
531     // Return stub type.
532     Stub_type
533     stub_type() const
534     { return this->stub_type_; }
535
536     // Return the local symbol index or invalid_index.
537     unsigned int
538     r_sym() const
539     { return this->r_sym_; }
540
541     // Return the symbol if there is one.
542     const Symbol*
543     symbol() const
544     { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
545
546     // Return the relobj if there is one.
547     const Relobj*
548     relobj() const
549     { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
550
551     // Whether this equals to another key k.
552     bool
553     eq(const Key& k) const 
554     {
555       return ((this->stub_type_ == k.stub_type_)
556               && (this->r_sym_ == k.r_sym_)
557               && ((this->r_sym_ != Reloc_stub::invalid_index)
558                   ? (this->u_.relobj == k.u_.relobj)
559                   : (this->u_.symbol == k.u_.symbol))
560               && (this->addend_ == k.addend_));
561     }
562
563     // Return a hash value.
564     size_t
565     hash_value() const
566     {
567       return (this->stub_type_
568               ^ this->r_sym_
569               ^ gold::string_hash<char>(
570                     (this->r_sym_ != Reloc_stub::invalid_index)
571                     ? this->u_.relobj->name().c_str()
572                     : this->u_.symbol->name())
573               ^ this->addend_);
574     }
575
576     // Functors for STL associative containers.
577     struct hash
578     {
579       size_t
580       operator()(const Key& k) const
581       { return k.hash_value(); }
582     };
583
584     struct equal_to
585     {
586       bool
587       operator()(const Key& k1, const Key& k2) const
588       { return k1.eq(k2); }
589     };
590
591     // Name of key.  This is mainly for debugging.
592     std::string
593     name() const;
594
595    private:
596     // Stub type.
597     Stub_type stub_type_;
598     // If this is a local symbol, this is the index in the defining object.
599     // Otherwise, it is invalid_index for a global symbol.
600     unsigned int r_sym_;
601     // If r_sym_ is invalid index.  This points to a global symbol.
602     // Otherwise, this points a relobj.  We used the unsized and target
603     // independent Symbol and Relobj classes instead of Sized_symbol<32> and  
604     // Arm_relobj.  This is done to avoid making the stub class a template
605     // as most of the stub machinery is endianness-neutral.  However, it
606     // may require a bit of casting done by users of this class.
607     union
608     {
609       const Symbol* symbol;
610       const Relobj* relobj;
611     } u_;
612     // Addend associated with a reloc.
613     int32_t addend_;
614   };
615
616  protected:
617   // Reloc_stubs are created via a stub factory.  So these are protected.
618   Reloc_stub(const Stub_template* stub_template)
619     : Stub(stub_template), destination_address_(invalid_address)
620   { }
621
622   ~Reloc_stub()
623   { }
624
625   friend class Stub_factory;
626
627   // Return the relocation target address of the i-th relocation in the
628   // stub.
629   Arm_address
630   do_reloc_target(size_t i)
631   {
632     // All reloc stub have only one relocation.
633     gold_assert(i == 0);
634     return this->destination_address_;
635   }
636
637  private:
638   // Address of destination.
639   Arm_address destination_address_;
640 };
641
642 // Cortex-A8 stub class.  We need a Cortex-A8 stub to redirect any 32-bit
643 // THUMB branch that meets the following conditions:
644 // 
645 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
646 //    branch address is 0xffe.
647 // 2. The branch target address is in the same page as the first word of the
648 //    branch.
649 // 3. The branch follows a 32-bit instruction which is not a branch.
650 //
651 // To do the fix up, we need to store the address of the branch instruction
652 // and its target at least.  We also need to store the original branch
653 // instruction bits for the condition code in a conditional branch.  The
654 // condition code is used in a special instruction template.  We also want
655 // to identify input sections needing Cortex-A8 workaround quickly.  We store
656 // extra information about object and section index of the code section
657 // containing a branch being fixed up.  The information is used to mark
658 // the code section when we finalize the Cortex-A8 stubs.
659 //
660
661 class Cortex_a8_stub : public Stub
662 {
663  public:
664   ~Cortex_a8_stub()
665   { }
666
667   // Return the object of the code section containing the branch being fixed
668   // up.
669   Relobj*
670   relobj() const
671   { return this->relobj_; }
672
673   // Return the section index of the code section containing the branch being
674   // fixed up.
675   unsigned int
676   shndx() const
677   { return this->shndx_; }
678
679   // Return the source address of stub.  This is the address of the original
680   // branch instruction.  LSB is 1 always set to indicate that it is a THUMB
681   // instruction.
682   Arm_address
683   source_address() const
684   { return this->source_address_; }
685
686   // Return the destination address of the stub.  This is the branch taken
687   // address of the original branch instruction.  LSB is 1 if it is a THUMB
688   // instruction address.
689   Arm_address
690   destination_address() const
691   { return this->destination_address_; }
692
693   // Return the instruction being fixed up.
694   uint32_t
695   original_insn() const
696   { return this->original_insn_; }
697
698  protected:
699   // Cortex_a8_stubs are created via a stub factory.  So these are protected.
700   Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
701                  unsigned int shndx, Arm_address source_address,
702                  Arm_address destination_address, uint32_t original_insn)
703     : Stub(stub_template), relobj_(relobj), shndx_(shndx),
704       source_address_(source_address | 1U),
705       destination_address_(destination_address),
706       original_insn_(original_insn)
707   { }
708
709   friend class Stub_factory;
710
711   // Return the relocation target address of the i-th relocation in the
712   // stub.
713   Arm_address
714   do_reloc_target(size_t i)
715   {
716     if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
717       {
718         // The conditional branch veneer has two relocations.
719         gold_assert(i < 2);
720         return i == 0 ? this->source_address_ + 4 : this->destination_address_;
721       }
722     else
723       {
724         // All other Cortex-A8 stubs have only one relocation.
725         gold_assert(i == 0);
726         return this->destination_address_;
727       }
728   }
729
730   // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
731   uint16_t
732   do_thumb16_special(size_t);
733
734  private:
735   // Object of the code section containing the branch being fixed up.
736   Relobj* relobj_;
737   // Section index of the code section containing the branch begin fixed up.
738   unsigned int shndx_;
739   // Source address of original branch.
740   Arm_address source_address_;
741   // Destination address of the original branch.
742   Arm_address destination_address_;
743   // Original branch instruction.  This is needed for copying the condition
744   // code from a condition branch to its stub.
745   uint32_t original_insn_;
746 };
747
748 // ARMv4 BX Rx branch relocation stub class.
749 class Arm_v4bx_stub : public Stub
750 {
751  public:
752   ~Arm_v4bx_stub()
753   { }
754
755   // Return the associated register.
756   uint32_t
757   reg() const
758   { return this->reg_; }
759
760  protected:
761   // Arm V4BX stubs are created via a stub factory.  So these are protected.
762   Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
763     : Stub(stub_template), reg_(reg)
764   { }
765
766   friend class Stub_factory;
767
768   // Return the relocation target address of the i-th relocation in the
769   // stub.
770   Arm_address
771   do_reloc_target(size_t)
772   { gold_unreachable(); }
773
774   // This may be overridden in the child class.
775   virtual void
776   do_write(unsigned char* view, section_size_type view_size, bool big_endian)
777   {
778     if (big_endian)
779       this->do_fixed_endian_v4bx_write<true>(view, view_size);
780     else
781       this->do_fixed_endian_v4bx_write<false>(view, view_size);
782   }
783
784  private:
785   // A template to implement do_write.
786   template<bool big_endian>
787   void inline
788   do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
789   {
790     const Insn_template* insns = this->stub_template()->insns();
791     elfcpp::Swap<32, big_endian>::writeval(view,
792                                            (insns[0].data()
793                                            + (this->reg_ << 16)));
794     view += insns[0].size();
795     elfcpp::Swap<32, big_endian>::writeval(view,
796                                            (insns[1].data() + this->reg_));
797     view += insns[1].size();
798     elfcpp::Swap<32, big_endian>::writeval(view,
799                                            (insns[2].data() + this->reg_));
800   }
801
802   // A register index (r0-r14), which is associated with the stub.
803   uint32_t reg_;
804 };
805
806 // Stub factory class.
807
808 class Stub_factory
809 {
810  public:
811   // Return the unique instance of this class.
812   static const Stub_factory&
813   get_instance()
814   {
815     static Stub_factory singleton;
816     return singleton;
817   }
818
819   // Make a relocation stub.
820   Reloc_stub*
821   make_reloc_stub(Stub_type stub_type) const
822   {
823     gold_assert(stub_type >= arm_stub_reloc_first
824                 && stub_type <= arm_stub_reloc_last);
825     return new Reloc_stub(this->stub_templates_[stub_type]);
826   }
827
828   // Make a Cortex-A8 stub.
829   Cortex_a8_stub*
830   make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
831                       Arm_address source, Arm_address destination,
832                       uint32_t original_insn) const
833   {
834     gold_assert(stub_type >= arm_stub_cortex_a8_first
835                 && stub_type <= arm_stub_cortex_a8_last);
836     return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
837                               source, destination, original_insn);
838   }
839
840   // Make an ARM V4BX relocation stub.
841   // This method creates a stub from the arm_stub_v4_veneer_bx template only.
842   Arm_v4bx_stub*
843   make_arm_v4bx_stub(uint32_t reg) const
844   {
845     gold_assert(reg < 0xf);
846     return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
847                              reg);
848   }
849
850  private:
851   // Constructor and destructor are protected since we only return a single
852   // instance created in Stub_factory::get_instance().
853   
854   Stub_factory();
855
856   // A Stub_factory may not be copied since it is a singleton.
857   Stub_factory(const Stub_factory&);
858   Stub_factory& operator=(Stub_factory&);
859   
860   // Stub templates.  These are initialized in the constructor.
861   const Stub_template* stub_templates_[arm_stub_type_last+1];
862 };
863
864 // A class to hold stubs for the ARM target.
865
866 template<bool big_endian>
867 class Stub_table : public Output_data
868 {
869  public:
870   Stub_table(Arm_input_section<big_endian>* owner)
871     : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
872       reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
873       prev_data_size_(0), prev_addralign_(1)
874   { }
875
876   ~Stub_table()
877   { }
878
879   // Owner of this stub table.
880   Arm_input_section<big_endian>*
881   owner() const
882   { return this->owner_; }
883
884   // Whether this stub table is empty.
885   bool
886   empty() const
887   {
888     return (this->reloc_stubs_.empty()
889             && this->cortex_a8_stubs_.empty()
890             && this->arm_v4bx_stubs_.empty());
891   }
892
893   // Return the current data size.
894   off_t
895   current_data_size() const
896   { return this->current_data_size_for_child(); }
897
898   // Add a STUB with using KEY.  Caller is reponsible for avoid adding
899   // if already a STUB with the same key has been added. 
900   void
901   add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
902   {
903     const Stub_template* stub_template = stub->stub_template();
904     gold_assert(stub_template->type() == key.stub_type());
905     this->reloc_stubs_[key] = stub;
906
907     // Assign stub offset early.  We can do this because we never remove
908     // reloc stubs and they are in the beginning of the stub table.
909     uint64_t align = stub_template->alignment();
910     this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
911     stub->set_offset(this->reloc_stubs_size_);
912     this->reloc_stubs_size_ += stub_template->size();
913     this->reloc_stubs_addralign_ =
914       std::max(this->reloc_stubs_addralign_, align);
915   }
916
917   // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
918   // Caller is reponsible for avoid adding if already a STUB with the same
919   // address has been added. 
920   void
921   add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
922   {
923     std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
924     this->cortex_a8_stubs_.insert(value);
925   }
926
927   // Add an ARM V4BX relocation stub. A register index will be retrieved
928   // from the stub.
929   void
930   add_arm_v4bx_stub(Arm_v4bx_stub* stub)
931   {
932     gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
933     this->arm_v4bx_stubs_[stub->reg()] = stub;
934   }
935
936   // Remove all Cortex-A8 stubs.
937   void
938   remove_all_cortex_a8_stubs();
939
940   // Look up a relocation stub using KEY.  Return NULL if there is none.
941   Reloc_stub*
942   find_reloc_stub(const Reloc_stub::Key& key) const
943   {
944     typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
945     return (p != this->reloc_stubs_.end()) ? p->second : NULL;
946   }
947
948   // Look up an arm v4bx relocation stub using the register index.
949   // Return NULL if there is none.
950   Arm_v4bx_stub*
951   find_arm_v4bx_stub(const uint32_t reg) const
952   {
953     gold_assert(reg < 0xf);
954     return this->arm_v4bx_stubs_[reg];
955   }
956
957   // Relocate stubs in this stub table.
958   void
959   relocate_stubs(const Relocate_info<32, big_endian>*,
960                  Target_arm<big_endian>*, Output_section*,
961                  unsigned char*, Arm_address, section_size_type);
962
963   // Update data size and alignment at the end of a relaxation pass.  Return
964   // true if either data size or alignment is different from that of the
965   // previous relaxation pass.
966   bool
967   update_data_size_and_addralign();
968
969   // Finalize stubs.  Set the offsets of all stubs and mark input sections
970   // needing the Cortex-A8 workaround.
971   void
972   finalize_stubs();
973   
974   // Apply Cortex-A8 workaround to an address range.
975   void
976   apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
977                                               unsigned char*, Arm_address,
978                                               section_size_type);
979
980  protected:
981   // Write out section contents.
982   void
983   do_write(Output_file*);
984  
985   // Return the required alignment.
986   uint64_t
987   do_addralign() const
988   { return this->prev_addralign_; }
989
990   // Reset address and file offset.
991   void
992   do_reset_address_and_file_offset()
993   { this->set_current_data_size_for_child(this->prev_data_size_); }
994
995   // Set final data size.
996   void
997   set_final_data_size()
998   { this->set_data_size(this->current_data_size()); }
999   
1000  private:
1001   // Relocate one stub.
1002   void
1003   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1004                 Target_arm<big_endian>*, Output_section*,
1005                 unsigned char*, Arm_address, section_size_type);
1006
1007   // Unordered map of relocation stubs.
1008   typedef
1009     Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1010                   Reloc_stub::Key::equal_to>
1011     Reloc_stub_map;
1012
1013   // List of Cortex-A8 stubs ordered by addresses of branches being
1014   // fixed up in output.
1015   typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1016   // List of Arm V4BX relocation stubs ordered by associated registers.
1017   typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1018
1019   // Owner of this stub table.
1020   Arm_input_section<big_endian>* owner_;
1021   // The relocation stubs.
1022   Reloc_stub_map reloc_stubs_;
1023   // Size of reloc stubs.
1024   off_t reloc_stubs_size_;
1025   // Maximum address alignment of reloc stubs.
1026   uint64_t reloc_stubs_addralign_;
1027   // The cortex_a8_stubs.
1028   Cortex_a8_stub_list cortex_a8_stubs_;
1029   // The Arm V4BX relocation stubs.
1030   Arm_v4bx_stub_list arm_v4bx_stubs_;
1031   // data size of this in the previous pass.
1032   off_t prev_data_size_;
1033   // address alignment of this in the previous pass.
1034   uint64_t prev_addralign_;
1035 };
1036
1037 // Arm_exidx_cantunwind class.  This represents an EXIDX_CANTUNWIND entry
1038 // we add to the end of an EXIDX input section that goes into the output.
1039
1040 class Arm_exidx_cantunwind : public Output_section_data
1041 {
1042  public:
1043   Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1044     : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1045   { }
1046
1047   // Return the object containing the section pointed by this.
1048   Relobj*
1049   relobj() const
1050   { return this->relobj_; }
1051
1052   // Return the section index of the section pointed by this.
1053   unsigned int
1054   shndx() const
1055   { return this->shndx_; }
1056
1057  protected:
1058   void
1059   do_write(Output_file* of)
1060   {
1061     if (parameters->target().is_big_endian())
1062       this->do_fixed_endian_write<true>(of);
1063     else
1064       this->do_fixed_endian_write<false>(of);
1065   }
1066
1067   // Write to a map file.
1068   void
1069   do_print_to_mapfile(Mapfile* mapfile) const
1070   { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1071
1072  private:
1073   // Implement do_write for a given endianness.
1074   template<bool big_endian>
1075   void inline
1076   do_fixed_endian_write(Output_file*);
1077   
1078   // The object containing the section pointed by this.
1079   Relobj* relobj_;
1080   // The section index of the section pointed by this.
1081   unsigned int shndx_;
1082 };
1083
1084 // During EXIDX coverage fix-up, we compact an EXIDX section.  The
1085 // Offset map is used to map input section offset within the EXIDX section
1086 // to the output offset from the start of this EXIDX section. 
1087
1088 typedef std::map<section_offset_type, section_offset_type>
1089         Arm_exidx_section_offset_map;
1090
1091 // Arm_exidx_merged_section class.  This represents an EXIDX input section
1092 // with some of its entries merged.
1093
1094 class Arm_exidx_merged_section : public Output_relaxed_input_section
1095 {
1096  public:
1097   // Constructor for Arm_exidx_merged_section.
1098   // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1099   // SECTION_OFFSET_MAP points to a section offset map describing how
1100   // parts of the input section are mapped to output.  DELETED_BYTES is
1101   // the number of bytes deleted from the EXIDX input section.
1102   Arm_exidx_merged_section(
1103       const Arm_exidx_input_section& exidx_input_section,
1104       const Arm_exidx_section_offset_map& section_offset_map,
1105       uint32_t deleted_bytes);
1106
1107   // Return the original EXIDX input section.
1108   const Arm_exidx_input_section&
1109   exidx_input_section() const
1110   { return this->exidx_input_section_; }
1111
1112   // Return the section offset map.
1113   const Arm_exidx_section_offset_map&
1114   section_offset_map() const
1115   { return this->section_offset_map_; }
1116
1117  protected:
1118   // Write merged section into file OF.
1119   void
1120   do_write(Output_file* of);
1121
1122   bool
1123   do_output_offset(const Relobj*, unsigned int, section_offset_type,
1124                   section_offset_type*) const;
1125
1126  private:
1127   // Original EXIDX input section.
1128   const Arm_exidx_input_section& exidx_input_section_;
1129   // Section offset map.
1130   const Arm_exidx_section_offset_map& section_offset_map_;
1131 };
1132
1133 // A class to wrap an ordinary input section containing executable code.
1134
1135 template<bool big_endian>
1136 class Arm_input_section : public Output_relaxed_input_section
1137 {
1138  public:
1139   Arm_input_section(Relobj* relobj, unsigned int shndx)
1140     : Output_relaxed_input_section(relobj, shndx, 1),
1141       original_addralign_(1), original_size_(0), stub_table_(NULL)
1142   { }
1143
1144   ~Arm_input_section()
1145   { }
1146
1147   // Initialize.
1148   void
1149   init();
1150   
1151   // Whether this is a stub table owner.
1152   bool
1153   is_stub_table_owner() const
1154   { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1155
1156   // Return the stub table.
1157   Stub_table<big_endian>*
1158   stub_table() const
1159   { return this->stub_table_; }
1160
1161   // Set the stub_table.
1162   void
1163   set_stub_table(Stub_table<big_endian>* stub_table)
1164   { this->stub_table_ = stub_table; }
1165
1166   // Downcast a base pointer to an Arm_input_section pointer.  This is
1167   // not type-safe but we only use Arm_input_section not the base class.
1168   static Arm_input_section<big_endian>*
1169   as_arm_input_section(Output_relaxed_input_section* poris)
1170   { return static_cast<Arm_input_section<big_endian>*>(poris); }
1171
1172   // Return the original size of the section.
1173   uint32_t
1174   original_size() const
1175   { return this->original_size_; }
1176
1177  protected:
1178   // Write data to output file.
1179   void
1180   do_write(Output_file*);
1181
1182   // Return required alignment of this.
1183   uint64_t
1184   do_addralign() const
1185   {
1186     if (this->is_stub_table_owner())
1187       return std::max(this->stub_table_->addralign(),
1188                       static_cast<uint64_t>(this->original_addralign_));
1189     else
1190       return this->original_addralign_;
1191   }
1192
1193   // Finalize data size.
1194   void
1195   set_final_data_size();
1196
1197   // Reset address and file offset.
1198   void
1199   do_reset_address_and_file_offset();
1200
1201   // Output offset.
1202   bool
1203   do_output_offset(const Relobj* object, unsigned int shndx,
1204                    section_offset_type offset,
1205                    section_offset_type* poutput) const
1206   {
1207     if ((object == this->relobj())
1208         && (shndx == this->shndx())
1209         && (offset >= 0)
1210         && (offset <=
1211             convert_types<section_offset_type, uint32_t>(this->original_size_)))
1212       {
1213         *poutput = offset;
1214         return true;
1215       }
1216     else
1217       return false;
1218   }
1219
1220  private:
1221   // Copying is not allowed.
1222   Arm_input_section(const Arm_input_section&);
1223   Arm_input_section& operator=(const Arm_input_section&);
1224
1225   // Address alignment of the original input section.
1226   uint32_t original_addralign_;
1227   // Section size of the original input section.
1228   uint32_t original_size_;
1229   // Stub table.
1230   Stub_table<big_endian>* stub_table_;
1231 };
1232
1233 // Arm_exidx_fixup class.  This is used to define a number of methods
1234 // and keep states for fixing up EXIDX coverage.
1235
1236 class Arm_exidx_fixup
1237 {
1238  public:
1239   Arm_exidx_fixup(Output_section* exidx_output_section,
1240                   bool merge_exidx_entries = true)
1241     : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1242       last_inlined_entry_(0), last_input_section_(NULL),
1243       section_offset_map_(NULL), first_output_text_section_(NULL),
1244       merge_exidx_entries_(merge_exidx_entries)
1245   { }
1246
1247   ~Arm_exidx_fixup()
1248   { delete this->section_offset_map_; }
1249
1250   // Process an EXIDX section for entry merging.  Return  number of bytes to
1251   // be deleted in output.  If parts of the input EXIDX section are merged
1252   // a heap allocated Arm_exidx_section_offset_map is store in the located
1253   // PSECTION_OFFSET_MAP.  The caller owns the map and is reponsible for
1254   // releasing it.
1255   template<bool big_endian>
1256   uint32_t
1257   process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1258                         Arm_exidx_section_offset_map** psection_offset_map);
1259   
1260   // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1261   // input section, if there is not one already.
1262   void
1263   add_exidx_cantunwind_as_needed();
1264
1265   // Return the output section for the text section which is linked to the
1266   // first exidx input in output.
1267   Output_section*
1268   first_output_text_section() const
1269   { return this->first_output_text_section_; }
1270
1271  private:
1272   // Copying is not allowed.
1273   Arm_exidx_fixup(const Arm_exidx_fixup&);
1274   Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1275
1276   // Type of EXIDX unwind entry.
1277   enum Unwind_type
1278   {
1279     // No type.
1280     UT_NONE,
1281     // EXIDX_CANTUNWIND.
1282     UT_EXIDX_CANTUNWIND,
1283     // Inlined entry.
1284     UT_INLINED_ENTRY,
1285     // Normal entry.
1286     UT_NORMAL_ENTRY,
1287   };
1288
1289   // Process an EXIDX entry.  We only care about the second word of the
1290   // entry.  Return true if the entry can be deleted.
1291   bool
1292   process_exidx_entry(uint32_t second_word);
1293
1294   // Update the current section offset map during EXIDX section fix-up.
1295   // If there is no map, create one.  INPUT_OFFSET is the offset of a
1296   // reference point, DELETED_BYTES is the number of deleted by in the
1297   // section so far.  If DELETE_ENTRY is true, the reference point and
1298   // all offsets after the previous reference point are discarded.
1299   void
1300   update_offset_map(section_offset_type input_offset,
1301                     section_size_type deleted_bytes, bool delete_entry);
1302
1303   // EXIDX output section.
1304   Output_section* exidx_output_section_;
1305   // Unwind type of the last EXIDX entry processed.
1306   Unwind_type last_unwind_type_;
1307   // Last seen inlined EXIDX entry.
1308   uint32_t last_inlined_entry_;
1309   // Last processed EXIDX input section.
1310   const Arm_exidx_input_section* last_input_section_;
1311   // Section offset map created in process_exidx_section.
1312   Arm_exidx_section_offset_map* section_offset_map_;
1313   // Output section for the text section which is linked to the first exidx
1314   // input in output.
1315   Output_section* first_output_text_section_;
1316
1317   bool merge_exidx_entries_;
1318 };
1319
1320 // Arm output section class.  This is defined mainly to add a number of
1321 // stub generation methods.
1322
1323 template<bool big_endian>
1324 class Arm_output_section : public Output_section
1325 {
1326  public:
1327   typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1328
1329   Arm_output_section(const char* name, elfcpp::Elf_Word type,
1330                      elfcpp::Elf_Xword flags)
1331     : Output_section(name, type, flags)
1332   {
1333     if (type == elfcpp::SHT_ARM_EXIDX)
1334       this->set_always_keeps_input_sections();
1335   }
1336
1337   ~Arm_output_section()
1338   { }
1339   
1340   // Group input sections for stub generation.
1341   void
1342   group_sections(section_size_type, bool, Target_arm<big_endian>*);
1343
1344   // Downcast a base pointer to an Arm_output_section pointer.  This is
1345   // not type-safe but we only use Arm_output_section not the base class.
1346   static Arm_output_section<big_endian>*
1347   as_arm_output_section(Output_section* os)
1348   { return static_cast<Arm_output_section<big_endian>*>(os); }
1349
1350   // Append all input text sections in this into LIST.
1351   void
1352   append_text_sections_to_list(Text_section_list* list);
1353
1354   // Fix EXIDX coverage of this EXIDX output section.  SORTED_TEXT_SECTION
1355   // is a list of text input sections sorted in ascending order of their
1356   // output addresses.
1357   void
1358   fix_exidx_coverage(Layout* layout,
1359                      const Text_section_list& sorted_text_section,
1360                      Symbol_table* symtab,
1361                      bool merge_exidx_entries);
1362
1363   // Link an EXIDX section into its corresponding text section.
1364   void
1365   set_exidx_section_link();
1366
1367  private:
1368   // For convenience.
1369   typedef Output_section::Input_section Input_section;
1370   typedef Output_section::Input_section_list Input_section_list;
1371
1372   // Create a stub group.
1373   void create_stub_group(Input_section_list::const_iterator,
1374                          Input_section_list::const_iterator,
1375                          Input_section_list::const_iterator,
1376                          Target_arm<big_endian>*,
1377                          std::vector<Output_relaxed_input_section*>*);
1378 };
1379
1380 // Arm_exidx_input_section class.  This represents an EXIDX input section.
1381
1382 class Arm_exidx_input_section
1383 {
1384  public:
1385   static const section_offset_type invalid_offset =
1386     static_cast<section_offset_type>(-1);
1387
1388   Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1389                           unsigned int link, uint32_t size, uint32_t addralign)
1390     : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1391       addralign_(addralign), has_errors_(false)
1392   { }
1393
1394   ~Arm_exidx_input_section()
1395   { }
1396         
1397   // Accessors:  This is a read-only class.
1398
1399   // Return the object containing this EXIDX input section.
1400   Relobj*
1401   relobj() const
1402   { return this->relobj_; }
1403
1404   // Return the section index of this EXIDX input section.
1405   unsigned int
1406   shndx() const
1407   { return this->shndx_; }
1408
1409   // Return the section index of linked text section in the same object.
1410   unsigned int
1411   link() const
1412   { return this->link_; }
1413
1414   // Return size of the EXIDX input section.
1415   uint32_t
1416   size() const
1417   { return this->size_; }
1418
1419   // Reutnr address alignment of EXIDX input section.
1420   uint32_t
1421   addralign() const
1422   { return this->addralign_; }
1423
1424   // Whether there are any errors in the EXIDX input section.
1425   bool
1426   has_errors() const
1427   { return this->has_errors_; }
1428
1429   // Set has-errors flag.
1430   void
1431   set_has_errors()
1432   { this->has_errors_ = true; }
1433
1434  private:
1435   // Object containing this.
1436   Relobj* relobj_;
1437   // Section index of this.
1438   unsigned int shndx_;
1439   // text section linked to this in the same object.
1440   unsigned int link_;
1441   // Size of this.  For ARM 32-bit is sufficient.
1442   uint32_t size_;
1443   // Address alignment of this.  For ARM 32-bit is sufficient.
1444   uint32_t addralign_;
1445   // Whether this has any errors.
1446   bool has_errors_;
1447 };
1448
1449 // Arm_relobj class.
1450
1451 template<bool big_endian>
1452 class Arm_relobj : public Sized_relobj<32, big_endian>
1453 {
1454  public:
1455   static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1456
1457   Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1458              const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1459     : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
1460       stub_tables_(), local_symbol_is_thumb_function_(),
1461       attributes_section_data_(NULL), mapping_symbols_info_(),
1462       section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1463       output_local_symbol_count_needs_update_(false),
1464       merge_flags_and_attributes_(true)
1465   { }
1466
1467   ~Arm_relobj()
1468   { delete this->attributes_section_data_; }
1469  
1470   // Return the stub table of the SHNDX-th section if there is one.
1471   Stub_table<big_endian>*
1472   stub_table(unsigned int shndx) const
1473   {
1474     gold_assert(shndx < this->stub_tables_.size());
1475     return this->stub_tables_[shndx];
1476   }
1477
1478   // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1479   void
1480   set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1481   {
1482     gold_assert(shndx < this->stub_tables_.size());
1483     this->stub_tables_[shndx] = stub_table;
1484   }
1485
1486   // Whether a local symbol is a THUMB function.  R_SYM is the symbol table
1487   // index.  This is only valid after do_count_local_symbol is called.
1488   bool
1489   local_symbol_is_thumb_function(unsigned int r_sym) const
1490   {
1491     gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1492     return this->local_symbol_is_thumb_function_[r_sym];
1493   }
1494   
1495   // Scan all relocation sections for stub generation.
1496   void
1497   scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1498                           const Layout*);
1499
1500   // Convert regular input section with index SHNDX to a relaxed section.
1501   void
1502   convert_input_section_to_relaxed_section(unsigned shndx)
1503   {
1504     // The stubs have relocations and we need to process them after writing
1505     // out the stubs.  So relocation now must follow section write.
1506     this->set_section_offset(shndx, -1ULL);
1507     this->set_relocs_must_follow_section_writes();
1508   }
1509
1510   // Downcast a base pointer to an Arm_relobj pointer.  This is
1511   // not type-safe but we only use Arm_relobj not the base class.
1512   static Arm_relobj<big_endian>*
1513   as_arm_relobj(Relobj* relobj)
1514   { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1515
1516   // Processor-specific flags in ELF file header.  This is valid only after
1517   // reading symbols.
1518   elfcpp::Elf_Word
1519   processor_specific_flags() const
1520   { return this->processor_specific_flags_; }
1521
1522   // Attribute section data  This is the contents of the .ARM.attribute section
1523   // if there is one.
1524   const Attributes_section_data*
1525   attributes_section_data() const
1526   { return this->attributes_section_data_; }
1527
1528   // Mapping symbol location.
1529   typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1530
1531   // Functor for STL container.
1532   struct Mapping_symbol_position_less
1533   {
1534     bool
1535     operator()(const Mapping_symbol_position& p1,
1536                const Mapping_symbol_position& p2) const
1537     {
1538       return (p1.first < p2.first
1539               || (p1.first == p2.first && p1.second < p2.second));
1540     }
1541   };
1542   
1543   // We only care about the first character of a mapping symbol, so
1544   // we only store that instead of the whole symbol name.
1545   typedef std::map<Mapping_symbol_position, char,
1546                    Mapping_symbol_position_less> Mapping_symbols_info;
1547
1548   // Whether a section contains any Cortex-A8 workaround.
1549   bool
1550   section_has_cortex_a8_workaround(unsigned int shndx) const
1551   { 
1552     return (this->section_has_cortex_a8_workaround_ != NULL
1553             && (*this->section_has_cortex_a8_workaround_)[shndx]);
1554   }
1555   
1556   // Mark a section that has Cortex-A8 workaround.
1557   void
1558   mark_section_for_cortex_a8_workaround(unsigned int shndx)
1559   {
1560     if (this->section_has_cortex_a8_workaround_ == NULL)
1561       this->section_has_cortex_a8_workaround_ =
1562         new std::vector<bool>(this->shnum(), false);
1563     (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1564   }
1565
1566   // Return the EXIDX section of an text section with index SHNDX or NULL
1567   // if the text section has no associated EXIDX section.
1568   const Arm_exidx_input_section*
1569   exidx_input_section_by_link(unsigned int shndx) const
1570   {
1571     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1572     return ((p != this->exidx_section_map_.end()
1573              && p->second->link() == shndx)
1574             ? p->second
1575             : NULL);
1576   }
1577
1578   // Return the EXIDX section with index SHNDX or NULL if there is none.
1579   const Arm_exidx_input_section*
1580   exidx_input_section_by_shndx(unsigned shndx) const
1581   {
1582     Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1583     return ((p != this->exidx_section_map_.end()
1584              && p->second->shndx() == shndx)
1585             ? p->second
1586             : NULL);
1587   }
1588
1589   // Whether output local symbol count needs updating.
1590   bool
1591   output_local_symbol_count_needs_update() const
1592   { return this->output_local_symbol_count_needs_update_; }
1593
1594   // Set output_local_symbol_count_needs_update flag to be true.
1595   void
1596   set_output_local_symbol_count_needs_update()
1597   { this->output_local_symbol_count_needs_update_ = true; }
1598   
1599   // Update output local symbol count at the end of relaxation.
1600   void
1601   update_output_local_symbol_count();
1602
1603   // Whether we want to merge processor-specific flags and attributes.
1604   bool
1605   merge_flags_and_attributes() const
1606   { return this->merge_flags_and_attributes_; }
1607   
1608   // Export list of EXIDX section indices.
1609   void
1610   get_exidx_shndx_list(std::vector<unsigned int>* list) const
1611   {
1612     list->clear();
1613     for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1614          p != this->exidx_section_map_.end();
1615          ++p)
1616       {
1617         if (p->second->shndx() == p->first)
1618           list->push_back(p->first);
1619       }
1620     // Sort list to make result independent of implementation of map. 
1621     std::sort(list->begin(), list->end());
1622   }
1623
1624  protected:
1625   // Post constructor setup.
1626   void
1627   do_setup()
1628   {
1629     // Call parent's setup method.
1630     Sized_relobj<32, big_endian>::do_setup();
1631
1632     // Initialize look-up tables.
1633     Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1634     this->stub_tables_.swap(empty_stub_table_list);
1635   }
1636
1637   // Count the local symbols.
1638   void
1639   do_count_local_symbols(Stringpool_template<char>*,
1640                          Stringpool_template<char>*);
1641
1642   void
1643   do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
1644                        const unsigned char* pshdrs, Output_file* of,
1645                        typename Sized_relobj<32, big_endian>::Views* pivews);
1646
1647   // Read the symbol information.
1648   void
1649   do_read_symbols(Read_symbols_data* sd);
1650
1651   // Process relocs for garbage collection.
1652   void
1653   do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1654
1655  private:
1656
1657   // Whether a section needs to be scanned for relocation stubs.
1658   bool
1659   section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1660                                     const Relobj::Output_sections&,
1661                                     const Symbol_table*, const unsigned char*);
1662
1663   // Whether a section is a scannable text section.
1664   bool
1665   section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1666                        const Output_section*, const Symbol_table*);
1667
1668   // Whether a section needs to be scanned for the Cortex-A8 erratum.
1669   bool
1670   section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1671                                         unsigned int, Output_section*,
1672                                         const Symbol_table*);
1673
1674   // Scan a section for the Cortex-A8 erratum.
1675   void
1676   scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1677                                      unsigned int, Output_section*,
1678                                      Target_arm<big_endian>*);
1679
1680   // Find the linked text section of an EXIDX section by looking at the
1681   // first reloction of the EXIDX section.  PSHDR points to the section
1682   // headers of a relocation section and PSYMS points to the local symbols.
1683   // PSHNDX points to a location storing the text section index if found.
1684   // Return whether we can find the linked section.
1685   bool
1686   find_linked_text_section(const unsigned char* pshdr,
1687                            const unsigned char* psyms, unsigned int* pshndx);
1688
1689   //
1690   // Make a new Arm_exidx_input_section object for EXIDX section with
1691   // index SHNDX and section header SHDR.  TEXT_SHNDX is the section
1692   // index of the linked text section.
1693   void
1694   make_exidx_input_section(unsigned int shndx,
1695                            const elfcpp::Shdr<32, big_endian>& shdr,
1696                            unsigned int text_shndx,
1697                            const elfcpp::Shdr<32, big_endian>& text_shdr);
1698
1699   // Return the output address of either a plain input section or a
1700   // relaxed input section.  SHNDX is the section index.
1701   Arm_address
1702   simple_input_section_output_address(unsigned int, Output_section*);
1703
1704   typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1705   typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1706     Exidx_section_map;
1707
1708   // List of stub tables.
1709   Stub_table_list stub_tables_;
1710   // Bit vector to tell if a local symbol is a thumb function or not.
1711   // This is only valid after do_count_local_symbol is called.
1712   std::vector<bool> local_symbol_is_thumb_function_;
1713   // processor-specific flags in ELF file header.
1714   elfcpp::Elf_Word processor_specific_flags_;
1715   // Object attributes if there is an .ARM.attributes section or NULL.
1716   Attributes_section_data* attributes_section_data_;
1717   // Mapping symbols information.
1718   Mapping_symbols_info mapping_symbols_info_;
1719   // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1720   std::vector<bool>* section_has_cortex_a8_workaround_;
1721   // Map a text section to its associated .ARM.exidx section, if there is one.
1722   Exidx_section_map exidx_section_map_;
1723   // Whether output local symbol count needs updating.
1724   bool output_local_symbol_count_needs_update_;
1725   // Whether we merge processor flags and attributes of this object to
1726   // output.
1727   bool merge_flags_and_attributes_;
1728 };
1729
1730 // Arm_dynobj class.
1731
1732 template<bool big_endian>
1733 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1734 {
1735  public:
1736   Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1737              const elfcpp::Ehdr<32, big_endian>& ehdr)
1738     : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1739       processor_specific_flags_(0), attributes_section_data_(NULL)
1740   { }
1741  
1742   ~Arm_dynobj()
1743   { delete this->attributes_section_data_; }
1744
1745   // Downcast a base pointer to an Arm_relobj pointer.  This is
1746   // not type-safe but we only use Arm_relobj not the base class.
1747   static Arm_dynobj<big_endian>*
1748   as_arm_dynobj(Dynobj* dynobj)
1749   { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1750
1751   // Processor-specific flags in ELF file header.  This is valid only after
1752   // reading symbols.
1753   elfcpp::Elf_Word
1754   processor_specific_flags() const
1755   { return this->processor_specific_flags_; }
1756
1757   // Attributes section data.
1758   const Attributes_section_data*
1759   attributes_section_data() const
1760   { return this->attributes_section_data_; }
1761
1762  protected:
1763   // Read the symbol information.
1764   void
1765   do_read_symbols(Read_symbols_data* sd);
1766
1767  private:
1768   // processor-specific flags in ELF file header.
1769   elfcpp::Elf_Word processor_specific_flags_;
1770   // Object attributes if there is an .ARM.attributes section or NULL.
1771   Attributes_section_data* attributes_section_data_;
1772 };
1773
1774 // Functor to read reloc addends during stub generation.
1775
1776 template<int sh_type, bool big_endian>
1777 struct Stub_addend_reader
1778 {
1779   // Return the addend for a relocation of a particular type.  Depending
1780   // on whether this is a REL or RELA relocation, read the addend from a
1781   // view or from a Reloc object.
1782   elfcpp::Elf_types<32>::Elf_Swxword
1783   operator()(
1784     unsigned int /* r_type */,
1785     const unsigned char* /* view */,
1786     const typename Reloc_types<sh_type,
1787                                32, big_endian>::Reloc& /* reloc */) const;
1788 };
1789
1790 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1791
1792 template<bool big_endian>
1793 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1794 {
1795   elfcpp::Elf_types<32>::Elf_Swxword
1796   operator()(
1797     unsigned int,
1798     const unsigned char*,
1799     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1800 };
1801
1802 // Specialized Stub_addend_reader for RELA type relocation sections.
1803 // We currently do not handle RELA type relocation sections but it is trivial
1804 // to implement the addend reader.  This is provided for completeness and to
1805 // make it easier to add support for RELA relocation sections in the future.
1806
1807 template<bool big_endian>
1808 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1809 {
1810   elfcpp::Elf_types<32>::Elf_Swxword
1811   operator()(
1812     unsigned int,
1813     const unsigned char*,
1814     const typename Reloc_types<elfcpp::SHT_RELA, 32,
1815                                big_endian>::Reloc& reloc) const
1816   { return reloc.get_r_addend(); }
1817 };
1818
1819 // Cortex_a8_reloc class.  We keep record of relocation that may need
1820 // the Cortex-A8 erratum workaround.
1821
1822 class Cortex_a8_reloc
1823 {
1824  public:
1825   Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1826                   Arm_address destination)
1827     : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1828   { }
1829
1830   ~Cortex_a8_reloc()
1831   { }
1832
1833   // Accessors:  This is a read-only class.
1834   
1835   // Return the relocation stub associated with this relocation if there is
1836   // one.
1837   const Reloc_stub*
1838   reloc_stub() const
1839   { return this->reloc_stub_; } 
1840   
1841   // Return the relocation type.
1842   unsigned int
1843   r_type() const
1844   { return this->r_type_; }
1845
1846   // Return the destination address of the relocation.  LSB stores the THUMB
1847   // bit.
1848   Arm_address
1849   destination() const
1850   { return this->destination_; }
1851
1852  private:
1853   // Associated relocation stub if there is one, or NULL.
1854   const Reloc_stub* reloc_stub_;
1855   // Relocation type.
1856   unsigned int r_type_;
1857   // Destination address of this relocation.  LSB is used to distinguish
1858   // ARM/THUMB mode.
1859   Arm_address destination_;
1860 };
1861
1862 // Arm_output_data_got class.  We derive this from Output_data_got to add
1863 // extra methods to handle TLS relocations in a static link.
1864
1865 template<bool big_endian>
1866 class Arm_output_data_got : public Output_data_got<32, big_endian>
1867 {
1868  public:
1869   Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1870     : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1871   { }
1872
1873   // Add a static entry for the GOT entry at OFFSET.  GSYM is a global
1874   // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1875   // applied in a static link.
1876   void
1877   add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1878   { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1879
1880   // Add a static reloc for the GOT entry at OFFSET.  RELOBJ is an object
1881   // defining a local symbol with INDEX.  R_TYPE is the code of a dynamic
1882   // relocation that needs to be applied in a static link.
1883   void
1884   add_static_reloc(unsigned int got_offset, unsigned int r_type,
1885                    Sized_relobj<32, big_endian>* relobj, unsigned int index)
1886   {
1887     this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1888                                                 index));
1889   }
1890
1891   // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
1892   // The first one is initialized to be 1, which is the module index for
1893   // the main executable and the second one 0.  A reloc of the type
1894   // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1895   // be applied by gold.  GSYM is a global symbol.
1896   void
1897   add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1898
1899   // Same as the above but for a local symbol in OBJECT with INDEX.
1900   void
1901   add_tls_gd32_with_static_reloc(unsigned int got_type,
1902                                  Sized_relobj<32, big_endian>* object,
1903                                  unsigned int index);
1904
1905  protected:
1906   // Write out the GOT table.
1907   void
1908   do_write(Output_file*);
1909
1910  private:
1911   // This class represent dynamic relocations that need to be applied by
1912   // gold because we are using TLS relocations in a static link.
1913   class Static_reloc
1914   {
1915    public:
1916     Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1917       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1918     { this->u_.global.symbol = gsym; }
1919
1920     Static_reloc(unsigned int got_offset, unsigned int r_type,
1921           Sized_relobj<32, big_endian>* relobj, unsigned int index)
1922       : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1923     {
1924       this->u_.local.relobj = relobj;
1925       this->u_.local.index = index;
1926     }
1927
1928     // Return the GOT offset.
1929     unsigned int
1930     got_offset() const
1931     { return this->got_offset_; }
1932
1933     // Relocation type.
1934     unsigned int
1935     r_type() const
1936     { return this->r_type_; }
1937
1938     // Whether the symbol is global or not.
1939     bool
1940     symbol_is_global() const
1941     { return this->symbol_is_global_; }
1942
1943     // For a relocation against a global symbol, the global symbol.
1944     Symbol*
1945     symbol() const
1946     {
1947       gold_assert(this->symbol_is_global_);
1948       return this->u_.global.symbol;
1949     }
1950
1951     // For a relocation against a local symbol, the defining object.
1952     Sized_relobj<32, big_endian>*
1953     relobj() const
1954     {
1955       gold_assert(!this->symbol_is_global_);
1956       return this->u_.local.relobj;
1957     }
1958
1959     // For a relocation against a local symbol, the local symbol index.
1960     unsigned int
1961     index() const
1962     {
1963       gold_assert(!this->symbol_is_global_);
1964       return this->u_.local.index;
1965     }
1966
1967    private:
1968     // GOT offset of the entry to which this relocation is applied.
1969     unsigned int got_offset_;
1970     // Type of relocation.
1971     unsigned int r_type_;
1972     // Whether this relocation is against a global symbol.
1973     bool symbol_is_global_;
1974     // A global or local symbol.
1975     union
1976     {
1977       struct
1978       {
1979         // For a global symbol, the symbol itself.
1980         Symbol* symbol;
1981       } global;
1982       struct
1983       {
1984         // For a local symbol, the object defining object.
1985         Sized_relobj<32, big_endian>* relobj;
1986         // For a local symbol, the symbol index.
1987         unsigned int index;
1988       } local;
1989     } u_;
1990   };
1991
1992   // Symbol table of the output object.
1993   Symbol_table* symbol_table_;
1994   // Layout of the output object.
1995   Layout* layout_;
1996   // Static relocs to be applied to the GOT.
1997   std::vector<Static_reloc> static_relocs_;
1998 };
1999
2000 // The ARM target has many relocation types with odd-sizes or incontigious
2001 // bits.  The default handling of relocatable relocation cannot process these
2002 // relocations.  So we have to extend the default code.
2003
2004 template<bool big_endian, int sh_type, typename Classify_reloc>
2005 class Arm_scan_relocatable_relocs :
2006   public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2007 {
2008  public:
2009   // Return the strategy to use for a local symbol which is a section
2010   // symbol, given the relocation type.
2011   inline Relocatable_relocs::Reloc_strategy
2012   local_section_strategy(unsigned int r_type, Relobj*)
2013   {
2014     if (sh_type == elfcpp::SHT_RELA)
2015       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2016     else
2017       {
2018         if (r_type == elfcpp::R_ARM_TARGET1
2019             || r_type == elfcpp::R_ARM_TARGET2)
2020           {
2021             const Target_arm<big_endian>* arm_target =
2022               Target_arm<big_endian>::default_target();
2023             r_type = arm_target->get_real_reloc_type(r_type);
2024           }
2025
2026         switch(r_type)
2027           {
2028           // Relocations that write nothing.  These exclude R_ARM_TARGET1
2029           // and R_ARM_TARGET2.
2030           case elfcpp::R_ARM_NONE:
2031           case elfcpp::R_ARM_V4BX:
2032           case elfcpp::R_ARM_TLS_GOTDESC:
2033           case elfcpp::R_ARM_TLS_CALL:
2034           case elfcpp::R_ARM_TLS_DESCSEQ:
2035           case elfcpp::R_ARM_THM_TLS_CALL:
2036           case elfcpp::R_ARM_GOTRELAX:
2037           case elfcpp::R_ARM_GNU_VTENTRY:
2038           case elfcpp::R_ARM_GNU_VTINHERIT:
2039           case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2040           case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2041             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2042           // These should have been converted to something else above.
2043           case elfcpp::R_ARM_TARGET1:
2044           case elfcpp::R_ARM_TARGET2:
2045             gold_unreachable();
2046           // Relocations that write full 32 bits.
2047           case elfcpp::R_ARM_ABS32:
2048           case elfcpp::R_ARM_REL32:
2049           case elfcpp::R_ARM_SBREL32:
2050           case elfcpp::R_ARM_GOTOFF32:
2051           case elfcpp::R_ARM_BASE_PREL:
2052           case elfcpp::R_ARM_GOT_BREL:
2053           case elfcpp::R_ARM_BASE_ABS:
2054           case elfcpp::R_ARM_ABS32_NOI:
2055           case elfcpp::R_ARM_REL32_NOI:
2056           case elfcpp::R_ARM_PLT32_ABS:
2057           case elfcpp::R_ARM_GOT_ABS:
2058           case elfcpp::R_ARM_GOT_PREL:
2059           case elfcpp::R_ARM_TLS_GD32:
2060           case elfcpp::R_ARM_TLS_LDM32:
2061           case elfcpp::R_ARM_TLS_LDO32:
2062           case elfcpp::R_ARM_TLS_IE32:
2063           case elfcpp::R_ARM_TLS_LE32:
2064             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4;
2065           default:
2066             // For all other static relocations, return RELOC_SPECIAL.
2067             return Relocatable_relocs::RELOC_SPECIAL;
2068           }
2069       }
2070   }
2071 };
2072
2073 // Utilities for manipulating integers of up to 32-bits
2074
2075 namespace utils
2076 {
2077   // Sign extend an n-bit unsigned integer stored in an uint32_t into
2078   // an int32_t.  NO_BITS must be between 1 to 32.
2079   template<int no_bits>
2080   static inline int32_t
2081   sign_extend(uint32_t bits)
2082   {
2083     gold_assert(no_bits >= 0 && no_bits <= 32);
2084     if (no_bits == 32)
2085       return static_cast<int32_t>(bits);
2086     uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
2087     bits &= mask;
2088     uint32_t top_bit = 1U << (no_bits - 1);
2089     int32_t as_signed = static_cast<int32_t>(bits);
2090     return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
2091   }
2092
2093   // Detects overflow of an NO_BITS integer stored in a uint32_t.
2094   template<int no_bits>
2095   static inline bool
2096   has_overflow(uint32_t bits)
2097   {
2098     gold_assert(no_bits >= 0 && no_bits <= 32);
2099     if (no_bits == 32)
2100       return false;
2101     int32_t max = (1 << (no_bits - 1)) - 1;
2102     int32_t min = -(1 << (no_bits - 1));
2103     int32_t as_signed = static_cast<int32_t>(bits);
2104     return as_signed > max || as_signed < min;
2105   }
2106
2107   // Detects overflow of an NO_BITS integer stored in a uint32_t when it
2108   // fits in the given number of bits as either a signed or unsigned value.
2109   // For example, has_signed_unsigned_overflow<8> would check
2110   // -128 <= bits <= 255
2111   template<int no_bits>
2112   static inline bool
2113   has_signed_unsigned_overflow(uint32_t bits)
2114   {
2115     gold_assert(no_bits >= 2 && no_bits <= 32);
2116     if (no_bits == 32)
2117       return false;
2118     int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
2119     int32_t min = -(1 << (no_bits - 1));
2120     int32_t as_signed = static_cast<int32_t>(bits);
2121     return as_signed > max || as_signed < min;
2122   }
2123
2124   // Select bits from A and B using bits in MASK.  For each n in [0..31],
2125   // the n-th bit in the result is chosen from the n-th bits of A and B.
2126   // A zero selects A and a one selects B.
2127   static inline uint32_t
2128   bit_select(uint32_t a, uint32_t b, uint32_t mask)
2129   { return (a & ~mask) | (b & mask); }
2130 };
2131
2132 template<bool big_endian>
2133 class Target_arm : public Sized_target<32, big_endian>
2134 {
2135  public:
2136   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2137     Reloc_section;
2138
2139   // When were are relocating a stub, we pass this as the relocation number.
2140   static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2141
2142   Target_arm()
2143     : Sized_target<32, big_endian>(&arm_info),
2144       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2145       copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL), 
2146       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2147       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2148       may_use_blx_(false), should_force_pic_veneer_(false),
2149       arm_input_section_map_(), attributes_section_data_(NULL),
2150       fix_cortex_a8_(false), cortex_a8_relocs_info_()
2151   { }
2152
2153   // Virtual function which is set to return true by a target if
2154   // it can use relocation types to determine if a function's
2155   // pointer is taken.
2156   virtual bool
2157   can_check_for_function_pointers() const
2158   { return true; }
2159
2160   // Whether a section called SECTION_NAME may have function pointers to
2161   // sections not eligible for safe ICF folding.
2162   virtual bool
2163   section_may_have_icf_unsafe_pointers(const char* section_name) const
2164   {
2165     return (!is_prefix_of(".ARM.exidx", section_name)
2166             && !is_prefix_of(".ARM.extab", section_name)
2167             && Target::section_may_have_icf_unsafe_pointers(section_name));
2168   }
2169   
2170   // Whether we can use BLX.
2171   bool
2172   may_use_blx() const
2173   { return this->may_use_blx_; }
2174
2175   // Set use-BLX flag.
2176   void
2177   set_may_use_blx(bool value)
2178   { this->may_use_blx_ = value; }
2179   
2180   // Whether we force PCI branch veneers.
2181   bool
2182   should_force_pic_veneer() const
2183   { return this->should_force_pic_veneer_; }
2184
2185   // Set PIC veneer flag.
2186   void
2187   set_should_force_pic_veneer(bool value)
2188   { this->should_force_pic_veneer_ = value; }
2189   
2190   // Whether we use THUMB-2 instructions.
2191   bool
2192   using_thumb2() const
2193   {
2194     Object_attribute* attr =
2195       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2196     int arch = attr->int_value();
2197     return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2198   }
2199
2200   // Whether we use THUMB/THUMB-2 instructions only.
2201   bool
2202   using_thumb_only() const
2203   {
2204     Object_attribute* attr =
2205       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2206
2207     if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2208         || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2209       return true;
2210     if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2211         && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2212       return false;
2213     attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2214     return attr->int_value() == 'M';
2215   }
2216
2217   // Whether we have an NOP instruction.  If not, use mov r0, r0 instead.
2218   bool
2219   may_use_arm_nop() const
2220   {
2221     Object_attribute* attr =
2222       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2223     int arch = attr->int_value();
2224     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2225             || arch == elfcpp::TAG_CPU_ARCH_V6K
2226             || arch == elfcpp::TAG_CPU_ARCH_V7
2227             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2228   }
2229
2230   // Whether we have THUMB-2 NOP.W instruction.
2231   bool
2232   may_use_thumb2_nop() const
2233   {
2234     Object_attribute* attr =
2235       this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2236     int arch = attr->int_value();
2237     return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2238             || arch == elfcpp::TAG_CPU_ARCH_V7
2239             || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2240   }
2241   
2242   // Process the relocations to determine unreferenced sections for 
2243   // garbage collection.
2244   void
2245   gc_process_relocs(Symbol_table* symtab,
2246                     Layout* layout,
2247                     Sized_relobj<32, big_endian>* object,
2248                     unsigned int data_shndx,
2249                     unsigned int sh_type,
2250                     const unsigned char* prelocs,
2251                     size_t reloc_count,
2252                     Output_section* output_section,
2253                     bool needs_special_offset_handling,
2254                     size_t local_symbol_count,
2255                     const unsigned char* plocal_symbols);
2256
2257   // Scan the relocations to look for symbol adjustments.
2258   void
2259   scan_relocs(Symbol_table* symtab,
2260               Layout* layout,
2261               Sized_relobj<32, big_endian>* object,
2262               unsigned int data_shndx,
2263               unsigned int sh_type,
2264               const unsigned char* prelocs,
2265               size_t reloc_count,
2266               Output_section* output_section,
2267               bool needs_special_offset_handling,
2268               size_t local_symbol_count,
2269               const unsigned char* plocal_symbols);
2270
2271   // Finalize the sections.
2272   void
2273   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2274
2275   // Return the value to use for a dynamic symbol which requires special
2276   // treatment.
2277   uint64_t
2278   do_dynsym_value(const Symbol*) const;
2279
2280   // Relocate a section.
2281   void
2282   relocate_section(const Relocate_info<32, big_endian>*,
2283                    unsigned int sh_type,
2284                    const unsigned char* prelocs,
2285                    size_t reloc_count,
2286                    Output_section* output_section,
2287                    bool needs_special_offset_handling,
2288                    unsigned char* view,
2289                    Arm_address view_address,
2290                    section_size_type view_size,
2291                    const Reloc_symbol_changes*);
2292
2293   // Scan the relocs during a relocatable link.
2294   void
2295   scan_relocatable_relocs(Symbol_table* symtab,
2296                           Layout* layout,
2297                           Sized_relobj<32, big_endian>* object,
2298                           unsigned int data_shndx,
2299                           unsigned int sh_type,
2300                           const unsigned char* prelocs,
2301                           size_t reloc_count,
2302                           Output_section* output_section,
2303                           bool needs_special_offset_handling,
2304                           size_t local_symbol_count,
2305                           const unsigned char* plocal_symbols,
2306                           Relocatable_relocs*);
2307
2308   // Relocate a section during a relocatable link.
2309   void
2310   relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2311                            unsigned int sh_type,
2312                            const unsigned char* prelocs,
2313                            size_t reloc_count,
2314                            Output_section* output_section,
2315                            off_t offset_in_output_section,
2316                            const Relocatable_relocs*,
2317                            unsigned char* view,
2318                            Arm_address view_address,
2319                            section_size_type view_size,
2320                            unsigned char* reloc_view,
2321                            section_size_type reloc_view_size);
2322
2323   // Perform target-specific processing in a relocatable link.  This is
2324   // only used if we use the relocation strategy RELOC_SPECIAL.
2325   void
2326   relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2327                                unsigned int sh_type,
2328                                const unsigned char* preloc_in,
2329                                size_t relnum,
2330                                Output_section* output_section,
2331                                off_t offset_in_output_section,
2332                                unsigned char* view,
2333                                typename elfcpp::Elf_types<32>::Elf_Addr
2334                                  view_address,
2335                                section_size_type view_size,
2336                                unsigned char* preloc_out);
2337  
2338   // Return whether SYM is defined by the ABI.
2339   bool
2340   do_is_defined_by_abi(Symbol* sym) const
2341   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2342
2343   // Return whether there is a GOT section.
2344   bool
2345   has_got_section() const
2346   { return this->got_ != NULL; }
2347
2348   // Return the size of the GOT section.
2349   section_size_type
2350   got_size() const
2351   {
2352     gold_assert(this->got_ != NULL);
2353     return this->got_->data_size();
2354   }
2355
2356   // Return the number of entries in the GOT.
2357   unsigned int
2358   got_entry_count() const
2359   {
2360     if (!this->has_got_section())
2361       return 0;
2362     return this->got_size() / 4;
2363   }
2364
2365   // Return the number of entries in the PLT.
2366   unsigned int
2367   plt_entry_count() const;
2368
2369   // Return the offset of the first non-reserved PLT entry.
2370   unsigned int
2371   first_plt_entry_offset() const;
2372
2373   // Return the size of each PLT entry.
2374   unsigned int
2375   plt_entry_size() const;
2376
2377   // Map platform-specific reloc types
2378   static unsigned int
2379   get_real_reloc_type(unsigned int r_type);
2380
2381   //
2382   // Methods to support stub-generations.
2383   //
2384   
2385   // Return the stub factory
2386   const Stub_factory&
2387   stub_factory() const
2388   { return this->stub_factory_; }
2389
2390   // Make a new Arm_input_section object.
2391   Arm_input_section<big_endian>*
2392   new_arm_input_section(Relobj*, unsigned int);
2393
2394   // Find the Arm_input_section object corresponding to the SHNDX-th input
2395   // section of RELOBJ.
2396   Arm_input_section<big_endian>*
2397   find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2398
2399   // Make a new Stub_table
2400   Stub_table<big_endian>*
2401   new_stub_table(Arm_input_section<big_endian>*);
2402
2403   // Scan a section for stub generation.
2404   void
2405   scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2406                          const unsigned char*, size_t, Output_section*,
2407                          bool, const unsigned char*, Arm_address,
2408                          section_size_type);
2409
2410   // Relocate a stub. 
2411   void
2412   relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2413                 Output_section*, unsigned char*, Arm_address,
2414                 section_size_type);
2415  
2416   // Get the default ARM target.
2417   static Target_arm<big_endian>*
2418   default_target()
2419   {
2420     gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2421                 && parameters->target().is_big_endian() == big_endian);
2422     return static_cast<Target_arm<big_endian>*>(
2423              parameters->sized_target<32, big_endian>());
2424   }
2425
2426   // Whether NAME belongs to a mapping symbol.
2427   static bool
2428   is_mapping_symbol_name(const char* name)
2429   {
2430     return (name
2431             && name[0] == '$'
2432             && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2433             && (name[2] == '\0' || name[2] == '.'));
2434   }
2435
2436   // Whether we work around the Cortex-A8 erratum.
2437   bool
2438   fix_cortex_a8() const
2439   { return this->fix_cortex_a8_; }
2440
2441   // Whether we merge exidx entries in debuginfo.
2442   bool
2443   merge_exidx_entries() const
2444   { return parameters->options().merge_exidx_entries(); }
2445
2446   // Whether we fix R_ARM_V4BX relocation.
2447   // 0 - do not fix
2448   // 1 - replace with MOV instruction (armv4 target)
2449   // 2 - make interworking veneer (>= armv4t targets only)
2450   General_options::Fix_v4bx
2451   fix_v4bx() const
2452   { return parameters->options().fix_v4bx(); }
2453
2454   // Scan a span of THUMB code section for Cortex-A8 erratum.
2455   void
2456   scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2457                                   section_size_type, section_size_type,
2458                                   const unsigned char*, Arm_address);
2459
2460   // Apply Cortex-A8 workaround to a branch.
2461   void
2462   apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2463                              unsigned char*, Arm_address);
2464
2465  protected:
2466   // Make an ELF object.
2467   Object*
2468   do_make_elf_object(const std::string&, Input_file*, off_t,
2469                      const elfcpp::Ehdr<32, big_endian>& ehdr);
2470
2471   Object*
2472   do_make_elf_object(const std::string&, Input_file*, off_t,
2473                      const elfcpp::Ehdr<32, !big_endian>&)
2474   { gold_unreachable(); }
2475
2476   Object*
2477   do_make_elf_object(const std::string&, Input_file*, off_t,
2478                       const elfcpp::Ehdr<64, false>&)
2479   { gold_unreachable(); }
2480
2481   Object*
2482   do_make_elf_object(const std::string&, Input_file*, off_t,
2483                      const elfcpp::Ehdr<64, true>&)
2484   { gold_unreachable(); }
2485
2486   // Make an output section.
2487   Output_section*
2488   do_make_output_section(const char* name, elfcpp::Elf_Word type,
2489                          elfcpp::Elf_Xword flags)
2490   { return new Arm_output_section<big_endian>(name, type, flags); }
2491
2492   void
2493   do_adjust_elf_header(unsigned char* view, int len) const;
2494
2495   // We only need to generate stubs, and hence perform relaxation if we are
2496   // not doing relocatable linking.
2497   bool
2498   do_may_relax() const
2499   { return !parameters->options().relocatable(); }
2500
2501   bool
2502   do_relax(int, const Input_objects*, Symbol_table*, Layout*);
2503
2504   // Determine whether an object attribute tag takes an integer, a
2505   // string or both.
2506   int
2507   do_attribute_arg_type(int tag) const;
2508
2509   // Reorder tags during output.
2510   int
2511   do_attributes_order(int num) const;
2512
2513   // This is called when the target is selected as the default.
2514   void
2515   do_select_as_default_target()
2516   {
2517     // No locking is required since there should only be one default target.
2518     // We cannot have both the big-endian and little-endian ARM targets
2519     // as the default.
2520     gold_assert(arm_reloc_property_table == NULL);
2521     arm_reloc_property_table = new Arm_reloc_property_table();
2522   }
2523
2524  private:
2525   // The class which scans relocations.
2526   class Scan
2527   {
2528    public:
2529     Scan()
2530       : issued_non_pic_error_(false)
2531     { }
2532
2533     inline void
2534     local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2535           Sized_relobj<32, big_endian>* object,
2536           unsigned int data_shndx,
2537           Output_section* output_section,
2538           const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2539           const elfcpp::Sym<32, big_endian>& lsym);
2540
2541     inline void
2542     global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2543            Sized_relobj<32, big_endian>* object,
2544            unsigned int data_shndx,
2545            Output_section* output_section,
2546            const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2547            Symbol* gsym);
2548
2549     inline bool
2550     local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2551                                         Sized_relobj<32, big_endian>* ,
2552                                         unsigned int ,
2553                                         Output_section* ,
2554                                         const elfcpp::Rel<32, big_endian>& ,
2555                                         unsigned int ,
2556                                         const elfcpp::Sym<32, big_endian>&);
2557
2558     inline bool
2559     global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2560                                          Sized_relobj<32, big_endian>* ,
2561                                          unsigned int ,
2562                                          Output_section* ,
2563                                          const elfcpp::Rel<32, big_endian>& ,
2564                                          unsigned int , Symbol*);
2565
2566    private:
2567     static void
2568     unsupported_reloc_local(Sized_relobj<32, big_endian>*,
2569                             unsigned int r_type);
2570
2571     static void
2572     unsupported_reloc_global(Sized_relobj<32, big_endian>*,
2573                              unsigned int r_type, Symbol*);
2574
2575     void
2576     check_non_pic(Relobj*, unsigned int r_type);
2577
2578     // Almost identical to Symbol::needs_plt_entry except that it also
2579     // handles STT_ARM_TFUNC.
2580     static bool
2581     symbol_needs_plt_entry(const Symbol* sym)
2582     {
2583       // An undefined symbol from an executable does not need a PLT entry.
2584       if (sym->is_undefined() && !parameters->options().shared())
2585         return false;
2586
2587       return (!parameters->doing_static_link()
2588               && (sym->type() == elfcpp::STT_FUNC
2589                   || sym->type() == elfcpp::STT_ARM_TFUNC)
2590               && (sym->is_from_dynobj()
2591                   || sym->is_undefined()
2592                   || sym->is_preemptible()));
2593     }
2594
2595     inline bool
2596     possible_function_pointer_reloc(unsigned int r_type);
2597
2598     // Whether we have issued an error about a non-PIC compilation.
2599     bool issued_non_pic_error_;
2600   };
2601
2602   // The class which implements relocation.
2603   class Relocate
2604   {
2605    public:
2606     Relocate()
2607     { }
2608
2609     ~Relocate()
2610     { }
2611
2612     // Return whether the static relocation needs to be applied.
2613     inline bool
2614     should_apply_static_reloc(const Sized_symbol<32>* gsym,
2615                               int ref_flags,
2616                               bool is_32bit,
2617                               Output_section* output_section);
2618
2619     // Do a relocation.  Return false if the caller should not issue
2620     // any warnings about this relocation.
2621     inline bool
2622     relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2623              Output_section*,  size_t relnum,
2624              const elfcpp::Rel<32, big_endian>&,
2625              unsigned int r_type, const Sized_symbol<32>*,
2626              const Symbol_value<32>*,
2627              unsigned char*, Arm_address,
2628              section_size_type);
2629
2630     // Return whether we want to pass flag NON_PIC_REF for this
2631     // reloc.  This means the relocation type accesses a symbol not via
2632     // GOT or PLT.
2633     static inline bool
2634     reloc_is_non_pic(unsigned int r_type)
2635     {
2636       switch (r_type)
2637         {
2638         // These relocation types reference GOT or PLT entries explicitly.
2639         case elfcpp::R_ARM_GOT_BREL:
2640         case elfcpp::R_ARM_GOT_ABS:
2641         case elfcpp::R_ARM_GOT_PREL:
2642         case elfcpp::R_ARM_GOT_BREL12:
2643         case elfcpp::R_ARM_PLT32_ABS:
2644         case elfcpp::R_ARM_TLS_GD32:
2645         case elfcpp::R_ARM_TLS_LDM32:
2646         case elfcpp::R_ARM_TLS_IE32:
2647         case elfcpp::R_ARM_TLS_IE12GP:
2648
2649         // These relocate types may use PLT entries.
2650         case elfcpp::R_ARM_CALL:
2651         case elfcpp::R_ARM_THM_CALL:
2652         case elfcpp::R_ARM_JUMP24:
2653         case elfcpp::R_ARM_THM_JUMP24:
2654         case elfcpp::R_ARM_THM_JUMP19:
2655         case elfcpp::R_ARM_PLT32:
2656         case elfcpp::R_ARM_THM_XPC22:
2657         case elfcpp::R_ARM_PREL31:
2658         case elfcpp::R_ARM_SBREL31:
2659           return false;
2660
2661         default:
2662           return true;
2663         }
2664     }
2665
2666    private:
2667     // Do a TLS relocation.
2668     inline typename Arm_relocate_functions<big_endian>::Status
2669     relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2670                  size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2671                  const Sized_symbol<32>*, const Symbol_value<32>*,
2672                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2673                  section_size_type);
2674
2675   };
2676
2677   // A class which returns the size required for a relocation type,
2678   // used while scanning relocs during a relocatable link.
2679   class Relocatable_size_for_reloc
2680   {
2681    public:
2682     unsigned int
2683     get_size_for_reloc(unsigned int, Relobj*);
2684   };
2685
2686   // Adjust TLS relocation type based on the options and whether this
2687   // is a local symbol.
2688   static tls::Tls_optimization
2689   optimize_tls_reloc(bool is_final, int r_type);
2690
2691   // Get the GOT section, creating it if necessary.
2692   Arm_output_data_got<big_endian>*
2693   got_section(Symbol_table*, Layout*);
2694
2695   // Get the GOT PLT section.
2696   Output_data_space*
2697   got_plt_section() const
2698   {
2699     gold_assert(this->got_plt_ != NULL);
2700     return this->got_plt_;
2701   }
2702
2703   // Create a PLT entry for a global symbol.
2704   void
2705   make_plt_entry(Symbol_table*, Layout*, Symbol*);
2706
2707   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2708   void
2709   define_tls_base_symbol(Symbol_table*, Layout*);
2710
2711   // Create a GOT entry for the TLS module index.
2712   unsigned int
2713   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2714                       Sized_relobj<32, big_endian>* object);
2715
2716   // Get the PLT section.
2717   const Output_data_plt_arm<big_endian>*
2718   plt_section() const
2719   {
2720     gold_assert(this->plt_ != NULL);
2721     return this->plt_;
2722   }
2723
2724   // Get the dynamic reloc section, creating it if necessary.
2725   Reloc_section*
2726   rel_dyn_section(Layout*);
2727
2728   // Get the section to use for TLS_DESC relocations.
2729   Reloc_section*
2730   rel_tls_desc_section(Layout*) const;
2731
2732   // Return true if the symbol may need a COPY relocation.
2733   // References from an executable object to non-function symbols
2734   // defined in a dynamic object may need a COPY relocation.
2735   bool
2736   may_need_copy_reloc(Symbol* gsym)
2737   {
2738     return (gsym->type() != elfcpp::STT_ARM_TFUNC
2739             && gsym->may_need_copy_reloc());
2740   }
2741
2742   // Add a potential copy relocation.
2743   void
2744   copy_reloc(Symbol_table* symtab, Layout* layout,
2745              Sized_relobj<32, big_endian>* object,
2746              unsigned int shndx, Output_section* output_section,
2747              Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2748   {
2749     this->copy_relocs_.copy_reloc(symtab, layout,
2750                                   symtab->get_sized_symbol<32>(sym),
2751                                   object, shndx, output_section, reloc,
2752                                   this->rel_dyn_section(layout));
2753   }
2754
2755   // Whether two EABI versions are compatible.
2756   static bool
2757   are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2758
2759   // Merge processor-specific flags from input object and those in the ELF
2760   // header of the output.
2761   void
2762   merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2763
2764   // Get the secondary compatible architecture.
2765   static int
2766   get_secondary_compatible_arch(const Attributes_section_data*);
2767
2768   // Set the secondary compatible architecture.
2769   static void
2770   set_secondary_compatible_arch(Attributes_section_data*, int);
2771
2772   static int
2773   tag_cpu_arch_combine(const char*, int, int*, int, int);
2774
2775   // Helper to print AEABI enum tag value.
2776   static std::string
2777   aeabi_enum_name(unsigned int);
2778
2779   // Return string value for TAG_CPU_name.
2780   static std::string
2781   tag_cpu_name_value(unsigned int);
2782
2783   // Merge object attributes from input object and those in the output.
2784   void
2785   merge_object_attributes(const char*, const Attributes_section_data*);
2786
2787   // Helper to get an AEABI object attribute
2788   Object_attribute*
2789   get_aeabi_object_attribute(int tag) const
2790   {
2791     Attributes_section_data* pasd = this->attributes_section_data_;
2792     gold_assert(pasd != NULL);
2793     Object_attribute* attr =
2794       pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2795     gold_assert(attr != NULL);
2796     return attr;
2797   }
2798
2799   //
2800   // Methods to support stub-generations.
2801   //
2802
2803   // Group input sections for stub generation.
2804   void
2805   group_sections(Layout*, section_size_type, bool);
2806
2807   // Scan a relocation for stub generation.
2808   void
2809   scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2810                       const Sized_symbol<32>*, unsigned int,
2811                       const Symbol_value<32>*,
2812                       elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2813
2814   // Scan a relocation section for stub.
2815   template<int sh_type>
2816   void
2817   scan_reloc_section_for_stubs(
2818       const Relocate_info<32, big_endian>* relinfo,
2819       const unsigned char* prelocs,
2820       size_t reloc_count,
2821       Output_section* output_section,
2822       bool needs_special_offset_handling,
2823       const unsigned char* view,
2824       elfcpp::Elf_types<32>::Elf_Addr view_address,
2825       section_size_type);
2826
2827   // Fix .ARM.exidx section coverage.
2828   void
2829   fix_exidx_coverage(Layout*, const Input_objects*,
2830                      Arm_output_section<big_endian>*, Symbol_table*);
2831
2832   // Functors for STL set.
2833   struct output_section_address_less_than
2834   {
2835     bool
2836     operator()(const Output_section* s1, const Output_section* s2) const
2837     { return s1->address() < s2->address(); }
2838   };
2839
2840   // Information about this specific target which we pass to the
2841   // general Target structure.
2842   static const Target::Target_info arm_info;
2843
2844   // The types of GOT entries needed for this platform.
2845   // These values are exposed to the ABI in an incremental link.
2846   // Do not renumber existing values without changing the version
2847   // number of the .gnu_incremental_inputs section.
2848   enum Got_type
2849   {
2850     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
2851     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
2852     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
2853     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
2854     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
2855   };
2856
2857   typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2858
2859   // Map input section to Arm_input_section.
2860   typedef Unordered_map<Section_id,
2861                         Arm_input_section<big_endian>*,
2862                         Section_id_hash>
2863           Arm_input_section_map;
2864     
2865   // Map output addresses to relocs for Cortex-A8 erratum.
2866   typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2867           Cortex_a8_relocs_info;
2868
2869   // The GOT section.
2870   Arm_output_data_got<big_endian>* got_;
2871   // The PLT section.
2872   Output_data_plt_arm<big_endian>* plt_;
2873   // The GOT PLT section.
2874   Output_data_space* got_plt_;
2875   // The dynamic reloc section.
2876   Reloc_section* rel_dyn_;
2877   // Relocs saved to avoid a COPY reloc.
2878   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2879   // Space for variables copied with a COPY reloc.
2880   Output_data_space* dynbss_;
2881   // Offset of the GOT entry for the TLS module index.
2882   unsigned int got_mod_index_offset_;
2883   // True if the _TLS_MODULE_BASE_ symbol has been defined.
2884   bool tls_base_symbol_defined_;
2885   // Vector of Stub_tables created.
2886   Stub_table_list stub_tables_;
2887   // Stub factory.
2888   const Stub_factory &stub_factory_;
2889   // Whether we can use BLX.
2890   bool may_use_blx_;
2891   // Whether we force PIC branch veneers.
2892   bool should_force_pic_veneer_;
2893   // Map for locating Arm_input_sections.
2894   Arm_input_section_map arm_input_section_map_;
2895   // Attributes section data in output.
2896   Attributes_section_data* attributes_section_data_;
2897   // Whether we want to fix code for Cortex-A8 erratum.
2898   bool fix_cortex_a8_;
2899   // Map addresses to relocs for Cortex-A8 erratum.
2900   Cortex_a8_relocs_info cortex_a8_relocs_info_;
2901 };
2902
2903 template<bool big_endian>
2904 const Target::Target_info Target_arm<big_endian>::arm_info =
2905 {
2906   32,                   // size
2907   big_endian,           // is_big_endian
2908   elfcpp::EM_ARM,       // machine_code
2909   false,                // has_make_symbol
2910   false,                // has_resolve
2911   false,                // has_code_fill
2912   true,                 // is_default_stack_executable
2913   '\0',                 // wrap_char
2914   "/usr/lib/libc.so.1", // dynamic_linker
2915   0x8000,               // default_text_segment_address
2916   0x1000,               // abi_pagesize (overridable by -z max-page-size)
2917   0x1000,               // common_pagesize (overridable by -z common-page-size)
2918   elfcpp::SHN_UNDEF,    // small_common_shndx
2919   elfcpp::SHN_UNDEF,    // large_common_shndx
2920   0,                    // small_common_section_flags
2921   0,                    // large_common_section_flags
2922   ".ARM.attributes",    // attributes_section
2923   "aeabi"               // attributes_vendor
2924 };
2925
2926 // Arm relocate functions class
2927 //
2928
2929 template<bool big_endian>
2930 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2931 {
2932  public:
2933   typedef enum
2934   {
2935     STATUS_OKAY,        // No error during relocation.
2936     STATUS_OVERFLOW,    // Relocation oveflow.
2937     STATUS_BAD_RELOC    // Relocation cannot be applied.
2938   } Status;
2939
2940  private:
2941   typedef Relocate_functions<32, big_endian> Base;
2942   typedef Arm_relocate_functions<big_endian> This;
2943
2944   // Encoding of imm16 argument for movt and movw ARM instructions
2945   // from ARM ARM:
2946   //     
2947   //     imm16 := imm4 | imm12
2948   //
2949   //  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 
2950   // +-------+---------------+-------+-------+-----------------------+
2951   // |       |               |imm4   |       |imm12                  |
2952   // +-------+---------------+-------+-------+-----------------------+
2953
2954   // Extract the relocation addend from VAL based on the ARM
2955   // instruction encoding described above.
2956   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2957   extract_arm_movw_movt_addend(
2958       typename elfcpp::Swap<32, big_endian>::Valtype val)
2959   {
2960     // According to the Elf ABI for ARM Architecture the immediate
2961     // field is sign-extended to form the addend.
2962     return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
2963   }
2964
2965   // Insert X into VAL based on the ARM instruction encoding described
2966   // above.
2967   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2968   insert_val_arm_movw_movt(
2969       typename elfcpp::Swap<32, big_endian>::Valtype val,
2970       typename elfcpp::Swap<32, big_endian>::Valtype x)
2971   {
2972     val &= 0xfff0f000;
2973     val |= x & 0x0fff;
2974     val |= (x & 0xf000) << 4;
2975     return val;
2976   }
2977
2978   // Encoding of imm16 argument for movt and movw Thumb2 instructions
2979   // from ARM ARM:
2980   //     
2981   //     imm16 := imm4 | i | imm3 | imm8
2982   //
2983   //  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 
2984   // +---------+-+-----------+-------++-+-----+-------+---------------+
2985   // |         |i|           |imm4   || |imm3 |       |imm8           |
2986   // +---------+-+-----------+-------++-+-----+-------+---------------+
2987
2988   // Extract the relocation addend from VAL based on the Thumb2
2989   // instruction encoding described above.
2990   static inline typename elfcpp::Swap<32, big_endian>::Valtype
2991   extract_thumb_movw_movt_addend(
2992       typename elfcpp::Swap<32, big_endian>::Valtype val)
2993   {
2994     // According to the Elf ABI for ARM Architecture the immediate
2995     // field is sign-extended to form the addend.
2996     return utils::sign_extend<16>(((val >> 4) & 0xf000)
2997                                   | ((val >> 15) & 0x0800)
2998                                   | ((val >> 4) & 0x0700)
2999                                   | (val & 0x00ff));
3000   }
3001
3002   // Insert X into VAL based on the Thumb2 instruction encoding
3003   // described above.
3004   static inline typename elfcpp::Swap<32, big_endian>::Valtype
3005   insert_val_thumb_movw_movt(
3006       typename elfcpp::Swap<32, big_endian>::Valtype val,
3007       typename elfcpp::Swap<32, big_endian>::Valtype x)
3008   {
3009     val &= 0xfbf08f00;
3010     val |= (x & 0xf000) << 4;
3011     val |= (x & 0x0800) << 15;
3012     val |= (x & 0x0700) << 4;
3013     val |= (x & 0x00ff);
3014     return val;
3015   }
3016
3017   // Calculate the smallest constant Kn for the specified residual.
3018   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3019   static uint32_t
3020   calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3021   {
3022     int32_t msb;
3023
3024     if (residual == 0)
3025       return 0;
3026     // Determine the most significant bit in the residual and
3027     // align the resulting value to a 2-bit boundary.
3028     for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3029       ;
3030     // The desired shift is now (msb - 6), or zero, whichever
3031     // is the greater.
3032     return (((msb - 6) < 0) ? 0 : (msb - 6));
3033   }
3034
3035   // Calculate the final residual for the specified group index.
3036   // If the passed group index is less than zero, the method will return
3037   // the value of the specified residual without any change.
3038   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3039   static typename elfcpp::Swap<32, big_endian>::Valtype
3040   calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3041                     const int group)
3042   {
3043     for (int n = 0; n <= group; n++)
3044       {
3045         // Calculate which part of the value to mask.
3046         uint32_t shift = calc_grp_kn(residual);
3047         // Calculate the residual for the next time around.
3048         residual &= ~(residual & (0xff << shift));
3049       }
3050
3051     return residual;
3052   }
3053
3054   // Calculate the value of Gn for the specified group index.
3055   // We return it in the form of an encoded constant-and-rotation.
3056   // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3057   static typename elfcpp::Swap<32, big_endian>::Valtype
3058   calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3059               const int group)
3060   {
3061     typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3062     uint32_t shift = 0;
3063
3064     for (int n = 0; n <= group; n++)
3065       {
3066         // Calculate which part of the value to mask.
3067         shift = calc_grp_kn(residual);
3068         // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3069         gn = residual & (0xff << shift);
3070         // Calculate the residual for the next time around.
3071         residual &= ~gn;
3072       }
3073     // Return Gn in the form of an encoded constant-and-rotation.
3074     return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3075   }
3076
3077  public:
3078   // Handle ARM long branches.
3079   static typename This::Status
3080   arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3081                     unsigned char*, const Sized_symbol<32>*,
3082                     const Arm_relobj<big_endian>*, unsigned int,
3083                     const Symbol_value<32>*, Arm_address, Arm_address, bool);
3084
3085   // Handle THUMB long branches.
3086   static typename This::Status
3087   thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3088                       unsigned char*, const Sized_symbol<32>*,
3089                       const Arm_relobj<big_endian>*, unsigned int,
3090                       const Symbol_value<32>*, Arm_address, Arm_address, bool);
3091
3092
3093   // Return the branch offset of a 32-bit THUMB branch.
3094   static inline int32_t
3095   thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3096   {
3097     // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3098     // involving the J1 and J2 bits.
3099     uint32_t s = (upper_insn & (1U << 10)) >> 10;
3100     uint32_t upper = upper_insn & 0x3ffU;
3101     uint32_t lower = lower_insn & 0x7ffU;
3102     uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3103     uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3104     uint32_t i1 = j1 ^ s ? 0 : 1;
3105     uint32_t i2 = j2 ^ s ? 0 : 1;
3106
3107     return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
3108                                   | (upper << 12) | (lower << 1));
3109   }
3110
3111   // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3112   // UPPER_INSN is the original upper instruction of the branch.  Caller is
3113   // responsible for overflow checking and BLX offset adjustment.
3114   static inline uint16_t
3115   thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3116   {
3117     uint32_t s = offset < 0 ? 1 : 0;
3118     uint32_t bits = static_cast<uint32_t>(offset);
3119     return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3120   }
3121
3122   // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3123   // LOWER_INSN is the original lower instruction of the branch.  Caller is
3124   // responsible for overflow checking and BLX offset adjustment.
3125   static inline uint16_t
3126   thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3127   {
3128     uint32_t s = offset < 0 ? 1 : 0;
3129     uint32_t bits = static_cast<uint32_t>(offset);
3130     return ((lower_insn & ~0x2fffU)
3131             | ((((bits >> 23) & 1) ^ !s) << 13)
3132             | ((((bits >> 22) & 1) ^ !s) << 11)
3133             | ((bits >> 1) & 0x7ffU));
3134   }
3135
3136   // Return the branch offset of a 32-bit THUMB conditional branch.
3137   static inline int32_t
3138   thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3139   {
3140     uint32_t s = (upper_insn & 0x0400U) >> 10;
3141     uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3142     uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3143     uint32_t lower = (lower_insn & 0x07ffU);
3144     uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3145
3146     return utils::sign_extend<21>((upper << 12) | (lower << 1));
3147   }
3148
3149   // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3150   // instruction.  UPPER_INSN is the original upper instruction of the branch.
3151   // Caller is responsible for overflow checking.
3152   static inline uint16_t
3153   thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3154   {
3155     uint32_t s = offset < 0 ? 1 : 0;
3156     uint32_t bits = static_cast<uint32_t>(offset);
3157     return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3158   }
3159
3160   // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3161   // instruction.  LOWER_INSN is the original lower instruction of the branch.
3162   // Caller is reponsible for overflow checking.
3163   static inline uint16_t
3164   thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3165   {
3166     uint32_t bits = static_cast<uint32_t>(offset);
3167     uint32_t j2 = (bits & 0x00080000U) >> 19;
3168     uint32_t j1 = (bits & 0x00040000U) >> 18;
3169     uint32_t lo = (bits & 0x00000ffeU) >> 1;
3170
3171     return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3172   }
3173
3174   // R_ARM_ABS8: S + A
3175   static inline typename This::Status
3176   abs8(unsigned char* view,
3177        const Sized_relobj<32, big_endian>* object,
3178        const Symbol_value<32>* psymval)
3179   {
3180     typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3181     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3182     Valtype* wv = reinterpret_cast<Valtype*>(view);
3183     Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3184     Reltype addend = utils::sign_extend<8>(val);
3185     Reltype x = psymval->value(object, addend);
3186     val = utils::bit_select(val, x, 0xffU);
3187     elfcpp::Swap<8, big_endian>::writeval(wv, val);
3188
3189     // R_ARM_ABS8 permits signed or unsigned results.
3190     int signed_x = static_cast<int32_t>(x);
3191     return ((signed_x < -128 || signed_x > 255)
3192             ? This::STATUS_OVERFLOW
3193             : This::STATUS_OKAY);
3194   }
3195
3196   // R_ARM_THM_ABS5: S + A
3197   static inline typename This::Status
3198   thm_abs5(unsigned char* view,
3199        const Sized_relobj<32, big_endian>* object,
3200        const Symbol_value<32>* psymval)
3201   {
3202     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3203     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3204     Valtype* wv = reinterpret_cast<Valtype*>(view);
3205     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3206     Reltype addend = (val & 0x7e0U) >> 6;
3207     Reltype x = psymval->value(object, addend);
3208     val = utils::bit_select(val, x << 6, 0x7e0U);
3209     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3210
3211     // R_ARM_ABS16 permits signed or unsigned results.
3212     int signed_x = static_cast<int32_t>(x);
3213     return ((signed_x < -32768 || signed_x > 65535)
3214             ? This::STATUS_OVERFLOW
3215             : This::STATUS_OKAY);
3216   }
3217
3218   // R_ARM_ABS12: S + A
3219   static inline typename This::Status
3220   abs12(unsigned char* view,
3221         const Sized_relobj<32, big_endian>* object,
3222         const Symbol_value<32>* psymval)
3223   {
3224     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3225     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3226     Valtype* wv = reinterpret_cast<Valtype*>(view);
3227     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3228     Reltype addend = val & 0x0fffU;
3229     Reltype x = psymval->value(object, addend);
3230     val = utils::bit_select(val, x, 0x0fffU);
3231     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3232     return (utils::has_overflow<12>(x)
3233             ? This::STATUS_OVERFLOW
3234             : This::STATUS_OKAY);
3235   }
3236
3237   // R_ARM_ABS16: S + A
3238   static inline typename This::Status
3239   abs16(unsigned char* view,
3240         const Sized_relobj<32, big_endian>* object,
3241         const Symbol_value<32>* psymval)
3242   {
3243     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3244     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3245     Valtype* wv = reinterpret_cast<Valtype*>(view);
3246     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3247     Reltype addend = utils::sign_extend<16>(val);
3248     Reltype x = psymval->value(object, addend);
3249     val = utils::bit_select(val, x, 0xffffU);
3250     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3251     return (utils::has_signed_unsigned_overflow<16>(x)
3252             ? This::STATUS_OVERFLOW
3253             : This::STATUS_OKAY);
3254   }
3255
3256   // R_ARM_ABS32: (S + A) | T
3257   static inline typename This::Status
3258   abs32(unsigned char* view,
3259         const Sized_relobj<32, big_endian>* object,
3260         const Symbol_value<32>* psymval,
3261         Arm_address thumb_bit)
3262   {
3263     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3264     Valtype* wv = reinterpret_cast<Valtype*>(view);
3265     Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3266     Valtype x = psymval->value(object, addend) | thumb_bit;
3267     elfcpp::Swap<32, big_endian>::writeval(wv, x);
3268     return This::STATUS_OKAY;
3269   }
3270
3271   // R_ARM_REL32: (S + A) | T - P
3272   static inline typename This::Status
3273   rel32(unsigned char* view,
3274         const Sized_relobj<32, big_endian>* object,
3275         const Symbol_value<32>* psymval,
3276         Arm_address address,
3277         Arm_address thumb_bit)
3278   {
3279     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3280     Valtype* wv = reinterpret_cast<Valtype*>(view);
3281     Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3282     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3283     elfcpp::Swap<32, big_endian>::writeval(wv, x);
3284     return This::STATUS_OKAY;
3285   }
3286
3287   // R_ARM_THM_JUMP24: (S + A) | T - P
3288   static typename This::Status
3289   thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3290              const Symbol_value<32>* psymval, Arm_address address,
3291              Arm_address thumb_bit);
3292
3293   // R_ARM_THM_JUMP6: S + A â€“ P
3294   static inline typename This::Status
3295   thm_jump6(unsigned char* view,
3296             const Sized_relobj<32, big_endian>* object,
3297             const Symbol_value<32>* psymval,
3298             Arm_address address)
3299   {
3300     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3301     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3302     Valtype* wv = reinterpret_cast<Valtype*>(view);
3303     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3304     // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3305     Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3306     Reltype x = (psymval->value(object, addend) - address);
3307     val = (val & 0xfd07) | ((x  & 0x0040) << 3) | ((val & 0x003e) << 2);
3308     elfcpp::Swap<16, big_endian>::writeval(wv, val);
3309     // CZB does only forward jumps.
3310     return ((x > 0x007e)
3311             ? This::STATUS_OVERFLOW
3312             : This::STATUS_OKAY);
3313   }
3314
3315   // R_ARM_THM_JUMP8: S + A â€“ P
3316   static inline typename This::Status
3317   thm_jump8(unsigned char* view,
3318             const Sized_relobj<32, big_endian>* object,
3319             const Symbol_value<32>* psymval,
3320             Arm_address address)
3321   {
3322     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3323     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3324     Valtype* wv = reinterpret_cast<Valtype*>(view);
3325     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3326     Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3327     Reltype x = (psymval->value(object, addend) - address);
3328     elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3329     return (utils::has_overflow<8>(x)
3330             ? This::STATUS_OVERFLOW
3331             : This::STATUS_OKAY);
3332   }
3333
3334   // R_ARM_THM_JUMP11: S + A â€“ P
3335   static inline typename This::Status
3336   thm_jump11(unsigned char* view,
3337             const Sized_relobj<32, big_endian>* object,
3338             const Symbol_value<32>* psymval,
3339             Arm_address address)
3340   {
3341     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3342     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3343     Valtype* wv = reinterpret_cast<Valtype*>(view);
3344     Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3345     Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3346     Reltype x = (psymval->value(object, addend) - address);
3347     elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3348     return (utils::has_overflow<11>(x)
3349             ? This::STATUS_OVERFLOW
3350             : This::STATUS_OKAY);
3351   }
3352
3353   // R_ARM_BASE_PREL: B(S) + A - P
3354   static inline typename This::Status
3355   base_prel(unsigned char* view,
3356             Arm_address origin,
3357             Arm_address address)
3358   {
3359     Base::rel32(view, origin - address);
3360     return STATUS_OKAY;
3361   }
3362
3363   // R_ARM_BASE_ABS: B(S) + A
3364   static inline typename This::Status
3365   base_abs(unsigned char* view,
3366            Arm_address origin)
3367   {
3368     Base::rel32(view, origin);
3369     return STATUS_OKAY;
3370   }
3371
3372   // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3373   static inline typename This::Status
3374   got_brel(unsigned char* view,
3375            typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3376   {
3377     Base::rel32(view, got_offset);
3378     return This::STATUS_OKAY;
3379   }
3380
3381   // R_ARM_GOT_PREL: GOT(S) + A - P
3382   static inline typename This::Status
3383   got_prel(unsigned char* view,
3384            Arm_address got_entry,
3385            Arm_address address)
3386   {
3387     Base::rel32(view, got_entry - address);
3388     return This::STATUS_OKAY;
3389   }
3390
3391   // R_ARM_PREL: (S + A) | T - P
3392   static inline typename This::Status
3393   prel31(unsigned char* view,
3394          const Sized_relobj<32, big_endian>* object,
3395          const Symbol_value<32>* psymval,
3396          Arm_address address,
3397          Arm_address thumb_bit)
3398   {
3399     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3400     Valtype* wv = reinterpret_cast<Valtype*>(view);
3401     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3402     Valtype addend = utils::sign_extend<31>(val);
3403     Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3404     val = utils::bit_select(val, x, 0x7fffffffU);
3405     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3406     return (utils::has_overflow<31>(x) ?
3407             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3408   }
3409
3410   // R_ARM_MOVW_ABS_NC: (S + A) | T     (relative address base is )
3411   // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3412   // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3413   // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3414   static inline typename This::Status
3415   movw(unsigned char* view,
3416        const Sized_relobj<32, big_endian>* object,
3417        const Symbol_value<32>* psymval,
3418        Arm_address relative_address_base,
3419        Arm_address thumb_bit,
3420        bool check_overflow)
3421   {
3422     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3423     Valtype* wv = reinterpret_cast<Valtype*>(view);
3424     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3425     Valtype addend = This::extract_arm_movw_movt_addend(val);
3426     Valtype x = ((psymval->value(object, addend) | thumb_bit)
3427                  - relative_address_base);
3428     val = This::insert_val_arm_movw_movt(val, x);
3429     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3430     return ((check_overflow && utils::has_overflow<16>(x))
3431             ? This::STATUS_OVERFLOW
3432             : This::STATUS_OKAY);
3433   }
3434
3435   // R_ARM_MOVT_ABS: S + A      (relative address base is 0)
3436   // R_ARM_MOVT_PREL: S + A - P
3437   // R_ARM_MOVT_BREL: S + A - B(S)
3438   static inline typename This::Status
3439   movt(unsigned char* view,
3440        const Sized_relobj<32, big_endian>* object,
3441        const Symbol_value<32>* psymval,
3442        Arm_address relative_address_base)
3443   {
3444     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3445     Valtype* wv = reinterpret_cast<Valtype*>(view);
3446     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3447     Valtype addend = This::extract_arm_movw_movt_addend(val);
3448     Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3449     val = This::insert_val_arm_movw_movt(val, x);
3450     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3451     // FIXME: IHI0044D says that we should check for overflow.
3452     return This::STATUS_OKAY;
3453   }
3454
3455   // R_ARM_THM_MOVW_ABS_NC: S + A | T           (relative_address_base is 0)
3456   // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3457   // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3458   // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3459   static inline typename This::Status
3460   thm_movw(unsigned char* view,
3461            const Sized_relobj<32, big_endian>* object,
3462            const Symbol_value<32>* psymval,
3463            Arm_address relative_address_base,
3464            Arm_address thumb_bit,
3465            bool check_overflow)
3466   {
3467     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3468     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3469     Valtype* wv = reinterpret_cast<Valtype*>(view);
3470     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3471                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3472     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3473     Reltype x =
3474       (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3475     val = This::insert_val_thumb_movw_movt(val, x);
3476     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3477     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3478     return ((check_overflow && utils::has_overflow<16>(x))
3479             ? This::STATUS_OVERFLOW
3480             : This::STATUS_OKAY);
3481   }
3482
3483   // R_ARM_THM_MOVT_ABS: S + A          (relative address base is 0)
3484   // R_ARM_THM_MOVT_PREL: S + A - P
3485   // R_ARM_THM_MOVT_BREL: S + A - B(S)
3486   static inline typename This::Status
3487   thm_movt(unsigned char* view,
3488            const Sized_relobj<32, big_endian>* object,
3489            const Symbol_value<32>* psymval,
3490            Arm_address relative_address_base)
3491   {
3492     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3493     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3494     Valtype* wv = reinterpret_cast<Valtype*>(view);
3495     Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3496                   | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3497     Reltype addend = This::extract_thumb_movw_movt_addend(val);
3498     Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3499     val = This::insert_val_thumb_movw_movt(val, x);
3500     elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3501     elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3502     return This::STATUS_OKAY;
3503   }
3504
3505   // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3506   static inline typename This::Status
3507   thm_alu11(unsigned char* view,
3508             const Sized_relobj<32, big_endian>* object,
3509             const Symbol_value<32>* psymval,
3510             Arm_address address,
3511             Arm_address thumb_bit)
3512   {
3513     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3514     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3515     Valtype* wv = reinterpret_cast<Valtype*>(view);
3516     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3517                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3518
3519     //        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
3520     // -----------------------------------------------------------------------
3521     // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd     |imm8
3522     // ADDW   1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd     |imm8
3523     // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd     |imm8
3524     // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd     |imm8
3525     // SUBW   1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd     |imm8
3526     // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd     |imm8
3527
3528     // Determine a sign for the addend.
3529     const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3530                       || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3531     // Thumb2 addend encoding:
3532     // imm12 := i | imm3 | imm8
3533     int32_t addend = (insn & 0xff)
3534                      | ((insn & 0x00007000) >> 4)
3535                      | ((insn & 0x04000000) >> 15);
3536     // Apply a sign to the added.
3537     addend *= sign;
3538
3539     int32_t x = (psymval->value(object, addend) | thumb_bit)
3540                 - (address & 0xfffffffc);
3541     Reltype val = abs(x);
3542     // Mask out the value and a distinct part of the ADD/SUB opcode
3543     // (bits 7:5 of opword).
3544     insn = (insn & 0xfb0f8f00)
3545            | (val & 0xff)
3546            | ((val & 0x700) << 4)
3547            | ((val & 0x800) << 15);
3548     // Set the opcode according to whether the value to go in the
3549     // place is negative.
3550     if (x < 0)
3551       insn |= 0x00a00000;
3552
3553     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3554     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3555     return ((val > 0xfff) ?
3556             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3557   }
3558
3559   // R_ARM_THM_PC8: S + A - Pa (Thumb)
3560   static inline typename This::Status
3561   thm_pc8(unsigned char* view,
3562           const Sized_relobj<32, big_endian>* object,
3563           const Symbol_value<32>* psymval,
3564           Arm_address address)
3565   {
3566     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3567     typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3568     Valtype* wv = reinterpret_cast<Valtype*>(view);
3569     Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3570     Reltype addend = ((insn & 0x00ff) << 2);
3571     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3572     Reltype val = abs(x);
3573     insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3574
3575     elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3576     return ((val > 0x03fc)
3577             ? This::STATUS_OVERFLOW
3578             : This::STATUS_OKAY);
3579   }
3580
3581   // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3582   static inline typename This::Status
3583   thm_pc12(unsigned char* view,
3584            const Sized_relobj<32, big_endian>* object,
3585            const Symbol_value<32>* psymval,
3586            Arm_address address)
3587   {
3588     typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3589     typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3590     Valtype* wv = reinterpret_cast<Valtype*>(view);
3591     Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3592                    | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3593     // Determine a sign for the addend (positive if the U bit is 1).
3594     const int sign = (insn & 0x00800000) ? 1 : -1;
3595     int32_t addend = (insn & 0xfff);
3596     // Apply a sign to the added.
3597     addend *= sign;
3598
3599     int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3600     Reltype val = abs(x);
3601     // Mask out and apply the value and the U bit.
3602     insn = (insn & 0xff7ff000) | (val & 0xfff);
3603     // Set the U bit according to whether the value to go in the
3604     // place is positive.
3605     if (x >= 0)
3606       insn |= 0x00800000;
3607
3608     elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3609     elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3610     return ((val > 0xfff) ?
3611             This::STATUS_OVERFLOW : This::STATUS_OKAY);
3612   }
3613
3614   // R_ARM_V4BX
3615   static inline typename This::Status
3616   v4bx(const Relocate_info<32, big_endian>* relinfo,
3617        unsigned char* view,
3618        const Arm_relobj<big_endian>* object,
3619        const Arm_address address,
3620        const bool is_interworking)
3621   {
3622
3623     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3624     Valtype* wv = reinterpret_cast<Valtype*>(view);
3625     Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3626
3627     // Ensure that we have a BX instruction.
3628     gold_assert((val & 0x0ffffff0) == 0x012fff10);
3629     const uint32_t reg = (val & 0xf);
3630     if (is_interworking && reg != 0xf)
3631       {
3632         Stub_table<big_endian>* stub_table =
3633             object->stub_table(relinfo->data_shndx);
3634         gold_assert(stub_table != NULL);
3635
3636         Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3637         gold_assert(stub != NULL);
3638
3639         int32_t veneer_address =
3640             stub_table->address() + stub->offset() - 8 - address;
3641         gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3642                     && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3643         // Replace with a branch to veneer (B <addr>)
3644         val = (val & 0xf0000000) | 0x0a000000
3645               | ((veneer_address >> 2) & 0x00ffffff);
3646       }
3647     else
3648       {
3649         // Preserve Rm (lowest four bits) and the condition code
3650         // (highest four bits). Other bits encode MOV PC,Rm.
3651         val = (val & 0xf000000f) | 0x01a0f000;
3652       }
3653     elfcpp::Swap<32, big_endian>::writeval(wv, val);
3654     return This::STATUS_OKAY;
3655   }
3656
3657   // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3658   // R_ARM_ALU_PC_G0:    ((S + A) | T) - P
3659   // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3660   // R_ARM_ALU_PC_G1:    ((S + A) | T) - P
3661   // R_ARM_ALU_PC_G2:    ((S + A) | T) - P
3662   // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3663   // R_ARM_ALU_SB_G0:    ((S + A) | T) - B(S)
3664   // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3665   // R_ARM_ALU_SB_G1:    ((S + A) | T) - B(S)
3666   // R_ARM_ALU_SB_G2:    ((S + A) | T) - B(S)
3667   static inline typename This::Status
3668   arm_grp_alu(unsigned char* view,
3669         const Sized_relobj<32, big_endian>* object,
3670         const Symbol_value<32>* psymval,
3671         const int group,
3672         Arm_address address,
3673         Arm_address thumb_bit,
3674         bool check_overflow)
3675   {
3676     gold_assert(group >= 0 && group < 3);
3677     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3678     Valtype* wv = reinterpret_cast<Valtype*>(view);
3679     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3680
3681     // ALU group relocations are allowed only for the ADD/SUB instructions.
3682     // (0x00800000 - ADD, 0x00400000 - SUB)
3683     const Valtype opcode = insn & 0x01e00000;
3684     if (opcode != 0x00800000 && opcode != 0x00400000)
3685       return This::STATUS_BAD_RELOC;
3686
3687     // Determine a sign for the addend.
3688     const int sign = (opcode == 0x00800000) ? 1 : -1;
3689     // shifter = rotate_imm * 2
3690     const uint32_t shifter = (insn & 0xf00) >> 7;
3691     // Initial addend value.
3692     int32_t addend = insn & 0xff;
3693     // Rotate addend right by shifter.
3694     addend = (addend >> shifter) | (addend << (32 - shifter));
3695     // Apply a sign to the added.
3696     addend *= sign;
3697
3698     int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3699     Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3700     // Check for overflow if required
3701     if (check_overflow
3702         && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3703       return This::STATUS_OVERFLOW;
3704
3705     // Mask out the value and the ADD/SUB part of the opcode; take care
3706     // not to destroy the S bit.
3707     insn &= 0xff1ff000;
3708     // Set the opcode according to whether the value to go in the
3709     // place is negative.
3710     insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3711     // Encode the offset (encoded Gn).
3712     insn |= gn;
3713
3714     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3715     return This::STATUS_OKAY;
3716   }
3717
3718   // R_ARM_LDR_PC_G0: S + A - P
3719   // R_ARM_LDR_PC_G1: S + A - P
3720   // R_ARM_LDR_PC_G2: S + A - P
3721   // R_ARM_LDR_SB_G0: S + A - B(S)
3722   // R_ARM_LDR_SB_G1: S + A - B(S)
3723   // R_ARM_LDR_SB_G2: S + A - B(S)
3724   static inline typename This::Status
3725   arm_grp_ldr(unsigned char* view,
3726         const Sized_relobj<32, big_endian>* object,
3727         const Symbol_value<32>* psymval,
3728         const int group,
3729         Arm_address address)
3730   {
3731     gold_assert(group >= 0 && group < 3);
3732     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3733     Valtype* wv = reinterpret_cast<Valtype*>(view);
3734     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3735
3736     const int sign = (insn & 0x00800000) ? 1 : -1;
3737     int32_t addend = (insn & 0xfff) * sign;
3738     int32_t x = (psymval->value(object, addend) - address);
3739     // Calculate the relevant G(n-1) value to obtain this stage residual.
3740     Valtype residual =
3741         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3742     if (residual >= 0x1000)
3743       return This::STATUS_OVERFLOW;
3744
3745     // Mask out the value and U bit.
3746     insn &= 0xff7ff000;
3747     // Set the U bit for non-negative values.
3748     if (x >= 0)
3749       insn |= 0x00800000;
3750     insn |= residual;
3751
3752     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3753     return This::STATUS_OKAY;
3754   }
3755
3756   // R_ARM_LDRS_PC_G0: S + A - P
3757   // R_ARM_LDRS_PC_G1: S + A - P
3758   // R_ARM_LDRS_PC_G2: S + A - P
3759   // R_ARM_LDRS_SB_G0: S + A - B(S)
3760   // R_ARM_LDRS_SB_G1: S + A - B(S)
3761   // R_ARM_LDRS_SB_G2: S + A - B(S)
3762   static inline typename This::Status
3763   arm_grp_ldrs(unsigned char* view,
3764         const Sized_relobj<32, big_endian>* object,
3765         const Symbol_value<32>* psymval,
3766         const int group,
3767         Arm_address address)
3768   {
3769     gold_assert(group >= 0 && group < 3);
3770     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3771     Valtype* wv = reinterpret_cast<Valtype*>(view);
3772     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3773
3774     const int sign = (insn & 0x00800000) ? 1 : -1;
3775     int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3776     int32_t x = (psymval->value(object, addend) - address);
3777     // Calculate the relevant G(n-1) value to obtain this stage residual.
3778     Valtype residual =
3779         Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3780    if (residual >= 0x100)
3781       return This::STATUS_OVERFLOW;
3782
3783     // Mask out the value and U bit.
3784     insn &= 0xff7ff0f0;
3785     // Set the U bit for non-negative values.
3786     if (x >= 0)
3787       insn |= 0x00800000;
3788     insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3789
3790     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3791     return This::STATUS_OKAY;
3792   }
3793
3794   // R_ARM_LDC_PC_G0: S + A - P
3795   // R_ARM_LDC_PC_G1: S + A - P
3796   // R_ARM_LDC_PC_G2: S + A - P
3797   // R_ARM_LDC_SB_G0: S + A - B(S)
3798   // R_ARM_LDC_SB_G1: S + A - B(S)
3799   // R_ARM_LDC_SB_G2: S + A - B(S)
3800   static inline typename This::Status
3801   arm_grp_ldc(unsigned char* view,
3802       const Sized_relobj<32, big_endian>* object,
3803       const Symbol_value<32>* psymval,
3804       const int group,
3805       Arm_address address)
3806   {
3807     gold_assert(group >= 0 && group < 3);
3808     typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3809     Valtype* wv = reinterpret_cast<Valtype*>(view);
3810     Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3811
3812     const int sign = (insn & 0x00800000) ? 1 : -1;
3813     int32_t addend = ((insn & 0xff) << 2) * sign;
3814     int32_t x = (psymval->value(object, addend) - address);
3815     // Calculate the relevant G(n-1) value to obtain this stage residual.
3816     Valtype residual =
3817       Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3818     if ((residual & 0x3) != 0 || residual >= 0x400)
3819       return This::STATUS_OVERFLOW;
3820
3821     // Mask out the value and U bit.
3822     insn &= 0xff7fff00;
3823     // Set the U bit for non-negative values.
3824     if (x >= 0)
3825       insn |= 0x00800000;
3826     insn |= (residual >> 2);
3827
3828     elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3829     return This::STATUS_OKAY;
3830   }
3831 };
3832
3833 // Relocate ARM long branches.  This handles relocation types
3834 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3835 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3836 // undefined and we do not use PLT in this relocation.  In such a case,
3837 // the branch is converted into an NOP.
3838
3839 template<bool big_endian>
3840 typename Arm_relocate_functions<big_endian>::Status
3841 Arm_relocate_functions<big_endian>::arm_branch_common(
3842     unsigned int r_type,
3843     const Relocate_info<32, big_endian>* relinfo,
3844     unsigned char* view,
3845     const Sized_symbol<32>* gsym,
3846     const Arm_relobj<big_endian>* object,
3847     unsigned int r_sym,
3848     const Symbol_value<32>* psymval,
3849     Arm_address address,
3850     Arm_address thumb_bit,
3851     bool is_weakly_undefined_without_plt)
3852 {
3853   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3854   Valtype* wv = reinterpret_cast<Valtype*>(view);
3855   Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3856      
3857   bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3858                     && ((val & 0x0f000000UL) == 0x0a000000UL);
3859   bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3860   bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3861                           && ((val & 0x0f000000UL) == 0x0b000000UL);
3862   bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3863   bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3864
3865   // Check that the instruction is valid.
3866   if (r_type == elfcpp::R_ARM_CALL)
3867     {
3868       if (!insn_is_uncond_bl && !insn_is_blx)
3869         return This::STATUS_BAD_RELOC;
3870     }
3871   else if (r_type == elfcpp::R_ARM_JUMP24)
3872     {
3873       if (!insn_is_b && !insn_is_cond_bl)
3874         return This::STATUS_BAD_RELOC;
3875     }
3876   else if (r_type == elfcpp::R_ARM_PLT32)
3877     {
3878       if (!insn_is_any_branch)
3879         return This::STATUS_BAD_RELOC;
3880     }
3881   else if (r_type == elfcpp::R_ARM_XPC25)
3882     {
3883       // FIXME: AAELF document IH0044C does not say much about it other
3884       // than it being obsolete.
3885       if (!insn_is_any_branch)
3886         return This::STATUS_BAD_RELOC;
3887     }
3888   else
3889     gold_unreachable();
3890
3891   // A branch to an undefined weak symbol is turned into a jump to
3892   // the next instruction unless a PLT entry will be created.
3893   // Do the same for local undefined symbols.
3894   // The jump to the next instruction is optimized as a NOP depending
3895   // on the architecture.
3896   const Target_arm<big_endian>* arm_target =
3897     Target_arm<big_endian>::default_target();
3898   if (is_weakly_undefined_without_plt)
3899     {
3900       gold_assert(!parameters->options().relocatable());
3901       Valtype cond = val & 0xf0000000U;
3902       if (arm_target->may_use_arm_nop())
3903         val = cond | 0x0320f000;
3904       else
3905         val = cond | 0x01a00000;        // Using pre-UAL nop: mov r0, r0.
3906       elfcpp::Swap<32, big_endian>::writeval(wv, val);
3907       return This::STATUS_OKAY;
3908     }
3909  
3910   Valtype addend = utils::sign_extend<26>(val << 2);
3911   Valtype branch_target = psymval->value(object, addend);
3912   int32_t branch_offset = branch_target - address;
3913
3914   // We need a stub if the branch offset is too large or if we need
3915   // to switch mode.
3916   bool may_use_blx = arm_target->may_use_blx();
3917   Reloc_stub* stub = NULL;
3918
3919   if (!parameters->options().relocatable()
3920       && (utils::has_overflow<26>(branch_offset)
3921           || ((thumb_bit != 0)
3922               && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3923     {
3924       Valtype unadjusted_branch_target = psymval->value(object, 0);
3925
3926       Stub_type stub_type =
3927         Reloc_stub::stub_type_for_reloc(r_type, address,
3928                                         unadjusted_branch_target,
3929                                         (thumb_bit != 0));
3930       if (stub_type != arm_stub_none)
3931         {
3932           Stub_table<big_endian>* stub_table =
3933             object->stub_table(relinfo->data_shndx);
3934           gold_assert(stub_table != NULL);
3935
3936           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3937           stub = stub_table->find_reloc_stub(stub_key);
3938           gold_assert(stub != NULL);
3939           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3940           branch_target = stub_table->address() + stub->offset() + addend;
3941           branch_offset = branch_target - address;
3942           gold_assert(!utils::has_overflow<26>(branch_offset));
3943         }
3944     }
3945
3946   // At this point, if we still need to switch mode, the instruction
3947   // must either be a BLX or a BL that can be converted to a BLX.
3948   if (thumb_bit != 0)
3949     {
3950       // Turn BL to BLX.
3951       gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3952       val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3953     }
3954
3955   val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3956   elfcpp::Swap<32, big_endian>::writeval(wv, val);
3957   return (utils::has_overflow<26>(branch_offset)
3958           ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3959 }
3960
3961 // Relocate THUMB long branches.  This handles relocation types
3962 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3963 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
3964 // undefined and we do not use PLT in this relocation.  In such a case,
3965 // the branch is converted into an NOP.
3966
3967 template<bool big_endian>
3968 typename Arm_relocate_functions<big_endian>::Status
3969 Arm_relocate_functions<big_endian>::thumb_branch_common(
3970     unsigned int r_type,
3971     const Relocate_info<32, big_endian>* relinfo,
3972     unsigned char* view,
3973     const Sized_symbol<32>* gsym,
3974     const Arm_relobj<big_endian>* object,
3975     unsigned int r_sym,
3976     const Symbol_value<32>* psymval,
3977     Arm_address address,
3978     Arm_address thumb_bit,
3979     bool is_weakly_undefined_without_plt)
3980 {
3981   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3982   Valtype* wv = reinterpret_cast<Valtype*>(view);
3983   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3984   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3985
3986   // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3987   // into account.
3988   bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3989   bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3990      
3991   // Check that the instruction is valid.
3992   if (r_type == elfcpp::R_ARM_THM_CALL)
3993     {
3994       if (!is_bl_insn && !is_blx_insn)
3995         return This::STATUS_BAD_RELOC;
3996     }
3997   else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3998     {
3999       // This cannot be a BLX.
4000       if (!is_bl_insn)
4001         return This::STATUS_BAD_RELOC;
4002     }
4003   else if (r_type == elfcpp::R_ARM_THM_XPC22)
4004     {
4005       // Check for Thumb to Thumb call.
4006       if (!is_blx_insn)
4007         return This::STATUS_BAD_RELOC;
4008       if (thumb_bit != 0)
4009         {
4010           gold_warning(_("%s: Thumb BLX instruction targets "
4011                          "thumb function '%s'."),
4012                          object->name().c_str(),
4013                          (gsym ? gsym->name() : "(local)")); 
4014           // Convert BLX to BL.
4015           lower_insn |= 0x1000U;
4016         }
4017     }
4018   else
4019     gold_unreachable();
4020
4021   // A branch to an undefined weak symbol is turned into a jump to
4022   // the next instruction unless a PLT entry will be created.
4023   // The jump to the next instruction is optimized as a NOP.W for
4024   // Thumb-2 enabled architectures.
4025   const Target_arm<big_endian>* arm_target =
4026     Target_arm<big_endian>::default_target();
4027   if (is_weakly_undefined_without_plt)
4028     {
4029       gold_assert(!parameters->options().relocatable());
4030       if (arm_target->may_use_thumb2_nop())
4031         {
4032           elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4033           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4034         }
4035       else
4036         {
4037           elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4038           elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4039         }
4040       return This::STATUS_OKAY;
4041     }
4042  
4043   int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4044   Arm_address branch_target = psymval->value(object, addend);
4045
4046   // For BLX, bit 1 of target address comes from bit 1 of base address.
4047   bool may_use_blx = arm_target->may_use_blx();
4048   if (thumb_bit == 0 && may_use_blx)
4049     branch_target = utils::bit_select(branch_target, address, 0x2);
4050
4051   int32_t branch_offset = branch_target - address;
4052
4053   // We need a stub if the branch offset is too large or if we need
4054   // to switch mode.
4055   bool thumb2 = arm_target->using_thumb2();
4056   if (!parameters->options().relocatable()
4057       && ((!thumb2 && utils::has_overflow<23>(branch_offset))
4058           || (thumb2 && utils::has_overflow<25>(branch_offset))
4059           || ((thumb_bit == 0)
4060               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4061                   || r_type == elfcpp::R_ARM_THM_JUMP24))))
4062     {
4063       Arm_address unadjusted_branch_target = psymval->value(object, 0);
4064
4065       Stub_type stub_type =
4066         Reloc_stub::stub_type_for_reloc(r_type, address,
4067                                         unadjusted_branch_target,
4068                                         (thumb_bit != 0));
4069
4070       if (stub_type != arm_stub_none)
4071         {
4072           Stub_table<big_endian>* stub_table =
4073             object->stub_table(relinfo->data_shndx);
4074           gold_assert(stub_table != NULL);
4075
4076           Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4077           Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4078           gold_assert(stub != NULL);
4079           thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4080           branch_target = stub_table->address() + stub->offset() + addend;
4081           if (thumb_bit == 0 && may_use_blx) 
4082             branch_target = utils::bit_select(branch_target, address, 0x2);
4083           branch_offset = branch_target - address;
4084         }
4085     }
4086
4087   // At this point, if we still need to switch mode, the instruction
4088   // must either be a BLX or a BL that can be converted to a BLX.
4089   if (thumb_bit == 0)
4090     {
4091       gold_assert(may_use_blx
4092                   && (r_type == elfcpp::R_ARM_THM_CALL
4093                       || r_type == elfcpp::R_ARM_THM_XPC22));
4094       // Make sure this is a BLX.
4095       lower_insn &= ~0x1000U;
4096     }
4097   else
4098     {
4099       // Make sure this is a BL.
4100       lower_insn |= 0x1000U;
4101     }
4102
4103   // For a BLX instruction, make sure that the relocation is rounded up
4104   // to a word boundary.  This follows the semantics of the instruction
4105   // which specifies that bit 1 of the target address will come from bit
4106   // 1 of the base address.
4107   if ((lower_insn & 0x5000U) == 0x4000U)
4108     gold_assert((branch_offset & 3) == 0);
4109
4110   // Put BRANCH_OFFSET back into the insn.  Assumes two's complement.
4111   // We use the Thumb-2 encoding, which is safe even if dealing with
4112   // a Thumb-1 instruction by virtue of our overflow check above.  */
4113   upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4114   lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4115
4116   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4117   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4118
4119   gold_assert(!utils::has_overflow<25>(branch_offset));
4120
4121   return ((thumb2
4122            ? utils::has_overflow<25>(branch_offset)
4123            : utils::has_overflow<23>(branch_offset))
4124           ? This::STATUS_OVERFLOW
4125           : This::STATUS_OKAY);
4126 }
4127
4128 // Relocate THUMB-2 long conditional branches.
4129 // If IS_WEAK_UNDEFINED_WITH_PLT is true.  The target symbol is weakly
4130 // undefined and we do not use PLT in this relocation.  In such a case,
4131 // the branch is converted into an NOP.
4132
4133 template<bool big_endian>
4134 typename Arm_relocate_functions<big_endian>::Status
4135 Arm_relocate_functions<big_endian>::thm_jump19(
4136     unsigned char* view,
4137     const Arm_relobj<big_endian>* object,
4138     const Symbol_value<32>* psymval,
4139     Arm_address address,
4140     Arm_address thumb_bit)
4141 {
4142   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4143   Valtype* wv = reinterpret_cast<Valtype*>(view);
4144   uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4145   uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4146   int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4147
4148   Arm_address branch_target = psymval->value(object, addend);
4149   int32_t branch_offset = branch_target - address;
4150
4151   // ??? Should handle interworking?  GCC might someday try to
4152   // use this for tail calls.
4153   // FIXME: We do support thumb entry to PLT yet.
4154   if (thumb_bit == 0)
4155     {
4156       gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4157       return This::STATUS_BAD_RELOC;
4158     }
4159
4160   // Put RELOCATION back into the insn.
4161   upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4162   lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4163
4164   // Put the relocated value back in the object file:
4165   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4166   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4167
4168   return (utils::has_overflow<21>(branch_offset)
4169           ? This::STATUS_OVERFLOW
4170           : This::STATUS_OKAY);
4171 }
4172
4173 // Get the GOT section, creating it if necessary.
4174
4175 template<bool big_endian>
4176 Arm_output_data_got<big_endian>*
4177 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4178 {
4179   if (this->got_ == NULL)
4180     {
4181       gold_assert(symtab != NULL && layout != NULL);
4182
4183       this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4184
4185       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4186                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4187                                       this->got_, ORDER_DATA, false);
4188
4189       // The old GNU linker creates a .got.plt section.  We just
4190       // create another set of data in the .got section.  Note that we
4191       // always create a PLT if we create a GOT, although the PLT
4192       // might be empty.
4193       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4194       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4195                                       (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4196                                       this->got_plt_, ORDER_DATA, false);
4197
4198       // The first three entries are reserved.
4199       this->got_plt_->set_current_data_size(3 * 4);
4200
4201       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4202       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4203                                     Symbol_table::PREDEFINED,
4204                                     this->got_plt_,
4205                                     0, 0, elfcpp::STT_OBJECT,
4206                                     elfcpp::STB_LOCAL,
4207                                     elfcpp::STV_HIDDEN, 0,
4208                                     false, false);
4209     }
4210   return this->got_;
4211 }
4212
4213 // Get the dynamic reloc section, creating it if necessary.
4214
4215 template<bool big_endian>
4216 typename Target_arm<big_endian>::Reloc_section*
4217 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4218 {
4219   if (this->rel_dyn_ == NULL)
4220     {
4221       gold_assert(layout != NULL);
4222       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4223       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4224                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
4225                                       ORDER_DYNAMIC_RELOCS, false);
4226     }
4227   return this->rel_dyn_;
4228 }
4229
4230 // Insn_template methods.
4231
4232 // Return byte size of an instruction template.
4233
4234 size_t
4235 Insn_template::size() const
4236 {
4237   switch (this->type())
4238     {
4239     case THUMB16_TYPE:
4240     case THUMB16_SPECIAL_TYPE:
4241       return 2;
4242     case ARM_TYPE:
4243     case THUMB32_TYPE:
4244     case DATA_TYPE:
4245       return 4;
4246     default:
4247       gold_unreachable();
4248     }
4249 }
4250
4251 // Return alignment of an instruction template.
4252
4253 unsigned
4254 Insn_template::alignment() const
4255 {
4256   switch (this->type())
4257     {
4258     case THUMB16_TYPE:
4259     case THUMB16_SPECIAL_TYPE:
4260     case THUMB32_TYPE:
4261       return 2;
4262     case ARM_TYPE:
4263     case DATA_TYPE:
4264       return 4;
4265     default:
4266       gold_unreachable();
4267     }
4268 }
4269
4270 // Stub_template methods.
4271
4272 Stub_template::Stub_template(
4273     Stub_type type, const Insn_template* insns,
4274      size_t insn_count)
4275   : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4276     entry_in_thumb_mode_(false), relocs_()
4277 {
4278   off_t offset = 0;
4279
4280   // Compute byte size and alignment of stub template.
4281   for (size_t i = 0; i < insn_count; i++)
4282     {
4283       unsigned insn_alignment = insns[i].alignment();
4284       size_t insn_size = insns[i].size();
4285       gold_assert((offset & (insn_alignment - 1)) == 0);
4286       this->alignment_ = std::max(this->alignment_, insn_alignment);
4287       switch (insns[i].type())
4288         {
4289         case Insn_template::THUMB16_TYPE:
4290         case Insn_template::THUMB16_SPECIAL_TYPE:
4291           if (i == 0)
4292             this->entry_in_thumb_mode_ = true;
4293           break;
4294
4295         case Insn_template::THUMB32_TYPE:
4296           if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4297             this->relocs_.push_back(Reloc(i, offset));
4298           if (i == 0)
4299             this->entry_in_thumb_mode_ = true;
4300           break;
4301
4302         case Insn_template::ARM_TYPE:
4303           // Handle cases where the target is encoded within the
4304           // instruction.
4305           if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4306             this->relocs_.push_back(Reloc(i, offset));
4307           break;
4308
4309         case Insn_template::DATA_TYPE:
4310           // Entry point cannot be data.
4311           gold_assert(i != 0);
4312           this->relocs_.push_back(Reloc(i, offset));
4313           break;
4314
4315         default:
4316           gold_unreachable();
4317         }
4318       offset += insn_size; 
4319     }
4320   this->size_ = offset;
4321 }
4322
4323 // Stub methods.
4324
4325 // Template to implement do_write for a specific target endianness.
4326
4327 template<bool big_endian>
4328 void inline
4329 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4330 {
4331   const Stub_template* stub_template = this->stub_template();
4332   const Insn_template* insns = stub_template->insns();
4333
4334   // FIXME:  We do not handle BE8 encoding yet.
4335   unsigned char* pov = view;
4336   for (size_t i = 0; i < stub_template->insn_count(); i++)
4337     {
4338       switch (insns[i].type())
4339         {
4340         case Insn_template::THUMB16_TYPE:
4341           elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4342           break;
4343         case Insn_template::THUMB16_SPECIAL_TYPE:
4344           elfcpp::Swap<16, big_endian>::writeval(
4345               pov,
4346               this->thumb16_special(i));
4347           break;
4348         case Insn_template::THUMB32_TYPE:
4349           {
4350             uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4351             uint32_t lo = insns[i].data() & 0xffff;
4352             elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4353             elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4354           }
4355           break;
4356         case Insn_template::ARM_TYPE:
4357         case Insn_template::DATA_TYPE:
4358           elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4359           break;
4360         default:
4361           gold_unreachable();
4362         }
4363       pov += insns[i].size();
4364     }
4365   gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4366
4367
4368 // Reloc_stub::Key methods.
4369
4370 // Dump a Key as a string for debugging.
4371
4372 std::string
4373 Reloc_stub::Key::name() const
4374 {
4375   if (this->r_sym_ == invalid_index)
4376     {
4377       // Global symbol key name
4378       // <stub-type>:<symbol name>:<addend>.
4379       const std::string sym_name = this->u_.symbol->name();
4380       // We need to print two hex number and two colons.  So just add 100 bytes
4381       // to the symbol name size.
4382       size_t len = sym_name.size() + 100;
4383       char* buffer = new char[len];
4384       int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4385                        sym_name.c_str(), this->addend_);
4386       gold_assert(c > 0 && c < static_cast<int>(len));
4387       delete[] buffer;
4388       return std::string(buffer);
4389     }
4390   else
4391     {
4392       // local symbol key name
4393       // <stub-type>:<object>:<r_sym>:<addend>.
4394       const size_t len = 200;
4395       char buffer[len];
4396       int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4397                        this->u_.relobj, this->r_sym_, this->addend_);
4398       gold_assert(c > 0 && c < static_cast<int>(len));
4399       return std::string(buffer);
4400     }
4401 }
4402
4403 // Reloc_stub methods.
4404
4405 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4406 // LOCATION to DESTINATION.
4407 // This code is based on the arm_type_of_stub function in
4408 // bfd/elf32-arm.c.  We have changed the interface a liitle to keep the Stub
4409 // class simple.
4410
4411 Stub_type
4412 Reloc_stub::stub_type_for_reloc(
4413    unsigned int r_type,
4414    Arm_address location,
4415    Arm_address destination,
4416    bool target_is_thumb)
4417 {
4418   Stub_type stub_type = arm_stub_none;
4419
4420   // This is a bit ugly but we want to avoid using a templated class for
4421   // big and little endianities.
4422   bool may_use_blx;
4423   bool should_force_pic_veneer;
4424   bool thumb2;
4425   bool thumb_only;
4426   if (parameters->target().is_big_endian())
4427     {
4428       const Target_arm<true>* big_endian_target =
4429         Target_arm<true>::default_target();
4430       may_use_blx = big_endian_target->may_use_blx();
4431       should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4432       thumb2 = big_endian_target->using_thumb2();
4433       thumb_only = big_endian_target->using_thumb_only();
4434     }
4435   else
4436     {
4437       const Target_arm<false>* little_endian_target =
4438         Target_arm<false>::default_target();
4439       may_use_blx = little_endian_target->may_use_blx();
4440       should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4441       thumb2 = little_endian_target->using_thumb2();
4442       thumb_only = little_endian_target->using_thumb_only();
4443     }
4444
4445   int64_t branch_offset;
4446   if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4447     {
4448       // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4449       // base address (instruction address + 4).
4450       if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4451         destination = utils::bit_select(destination, location, 0x2);
4452       branch_offset = static_cast<int64_t>(destination) - location;
4453         
4454       // Handle cases where:
4455       // - this call goes too far (different Thumb/Thumb2 max
4456       //   distance)
4457       // - it's a Thumb->Arm call and blx is not available, or it's a
4458       //   Thumb->Arm branch (not bl). A stub is needed in this case.
4459       if ((!thumb2
4460             && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4461                 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4462           || (thumb2
4463               && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4464                   || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4465           || ((!target_is_thumb)
4466               && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4467                   || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4468         {
4469           if (target_is_thumb)
4470             {
4471               // Thumb to thumb.
4472               if (!thumb_only)
4473                 {
4474                   stub_type = (parameters->options().shared()
4475                                || should_force_pic_veneer)
4476                     // PIC stubs.
4477                     ? ((may_use_blx
4478                         && (r_type == elfcpp::R_ARM_THM_CALL))
4479                        // V5T and above. Stub starts with ARM code, so
4480                        // we must be able to switch mode before
4481                        // reaching it, which is only possible for 'bl'
4482                        // (ie R_ARM_THM_CALL relocation).
4483                        ? arm_stub_long_branch_any_thumb_pic
4484                        // On V4T, use Thumb code only.
4485                        : arm_stub_long_branch_v4t_thumb_thumb_pic)
4486
4487                     // non-PIC stubs.
4488                     : ((may_use_blx
4489                         && (r_type == elfcpp::R_ARM_THM_CALL))
4490                        ? arm_stub_long_branch_any_any // V5T and above.
4491                        : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4492                 }
4493               else
4494                 {
4495                   stub_type = (parameters->options().shared()
4496                                || should_force_pic_veneer)
4497                     ? arm_stub_long_branch_thumb_only_pic       // PIC stub.
4498                     : arm_stub_long_branch_thumb_only;  // non-PIC stub.
4499                 }
4500             }
4501           else
4502             {
4503               // Thumb to arm.
4504              
4505               // FIXME: We should check that the input section is from an
4506               // object that has interwork enabled.
4507
4508               stub_type = (parameters->options().shared()
4509                            || should_force_pic_veneer)
4510                 // PIC stubs.
4511                 ? ((may_use_blx
4512                     && (r_type == elfcpp::R_ARM_THM_CALL))
4513                    ? arm_stub_long_branch_any_arm_pic   // V5T and above.
4514                    : arm_stub_long_branch_v4t_thumb_arm_pic)    // V4T.
4515
4516                 // non-PIC stubs.
4517                 : ((may_use_blx
4518                     && (r_type == elfcpp::R_ARM_THM_CALL))
4519                    ? arm_stub_long_branch_any_any       // V5T and above.
4520                    : arm_stub_long_branch_v4t_thumb_arm);       // V4T.
4521
4522               // Handle v4t short branches.
4523               if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4524                   && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4525                   && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4526                 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4527             }
4528         }
4529     }
4530   else if (r_type == elfcpp::R_ARM_CALL
4531            || r_type == elfcpp::R_ARM_JUMP24
4532            || r_type == elfcpp::R_ARM_PLT32)
4533     {
4534       branch_offset = static_cast<int64_t>(destination) - location;
4535       if (target_is_thumb)
4536         {
4537           // Arm to thumb.
4538
4539           // FIXME: We should check that the input section is from an
4540           // object that has interwork enabled.
4541
4542           // We have an extra 2-bytes reach because of
4543           // the mode change (bit 24 (H) of BLX encoding).
4544           if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4545               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4546               || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4547               || (r_type == elfcpp::R_ARM_JUMP24)
4548               || (r_type == elfcpp::R_ARM_PLT32))
4549             {
4550               stub_type = (parameters->options().shared()
4551                            || should_force_pic_veneer)
4552                 // PIC stubs.
4553                 ? (may_use_blx
4554                    ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4555                    : arm_stub_long_branch_v4t_arm_thumb_pic)    // V4T stub.
4556
4557                 // non-PIC stubs.
4558                 : (may_use_blx
4559                    ? arm_stub_long_branch_any_any       // V5T and above.
4560                    : arm_stub_long_branch_v4t_arm_thumb);       // V4T.
4561             }
4562         }
4563       else
4564         {
4565           // Arm to arm.
4566           if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4567               || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4568             {
4569               stub_type = (parameters->options().shared()
4570                            || should_force_pic_veneer)
4571                 ? arm_stub_long_branch_any_arm_pic      // PIC stubs.
4572                 : arm_stub_long_branch_any_any;         /// non-PIC.
4573             }
4574         }
4575     }
4576
4577   return stub_type;
4578 }
4579
4580 // Cortex_a8_stub methods.
4581
4582 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4583 // I is the position of the instruction template in the stub template.
4584
4585 uint16_t
4586 Cortex_a8_stub::do_thumb16_special(size_t i)
4587 {
4588   // The only use of this is to copy condition code from a conditional
4589   // branch being worked around to the corresponding conditional branch in
4590   // to the stub.
4591   gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4592               && i == 0);
4593   uint16_t data = this->stub_template()->insns()[i].data();
4594   gold_assert((data & 0xff00U) == 0xd000U);
4595   data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4596   return data;
4597 }
4598
4599 // Stub_factory methods.
4600
4601 Stub_factory::Stub_factory()
4602 {
4603   // The instruction template sequences are declared as static
4604   // objects and initialized first time the constructor runs.
4605  
4606   // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4607   // to reach the stub if necessary.
4608   static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4609     {
4610       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4611       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4612                                                 // dcd   R_ARM_ABS32(X)
4613     };
4614   
4615   // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4616   // available.
4617   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4618     {
4619       Insn_template::arm_insn(0xe59fc000),      // ldr   ip, [pc, #0]
4620       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4621       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4622                                                 // dcd   R_ARM_ABS32(X)
4623     };
4624   
4625   // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4626   static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4627     {
4628       Insn_template::thumb16_insn(0xb401),      // push {r0}
4629       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4630       Insn_template::thumb16_insn(0x4684),      // mov  ip, r0
4631       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4632       Insn_template::thumb16_insn(0x4760),      // bx   ip
4633       Insn_template::thumb16_insn(0xbf00),      // nop
4634       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4635                                                 // dcd  R_ARM_ABS32(X)
4636     };
4637   
4638   // V4T Thumb -> Thumb long branch stub. Using the stack is not
4639   // allowed.
4640   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4641     {
4642       Insn_template::thumb16_insn(0x4778),      // bx   pc
4643       Insn_template::thumb16_insn(0x46c0),      // nop
4644       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4645       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4646       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4647                                                 // dcd  R_ARM_ABS32(X)
4648     };
4649   
4650   // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4651   // available.
4652   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4653     {
4654       Insn_template::thumb16_insn(0x4778),      // bx   pc
4655       Insn_template::thumb16_insn(0x46c0),      // nop
4656       Insn_template::arm_insn(0xe51ff004),      // ldr   pc, [pc, #-4]
4657       Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4658                                                 // dcd   R_ARM_ABS32(X)
4659     };
4660   
4661   // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4662   // one, when the destination is close enough.
4663   static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4664     {
4665       Insn_template::thumb16_insn(0x4778),              // bx   pc
4666       Insn_template::thumb16_insn(0x46c0),              // nop
4667       Insn_template::arm_rel_insn(0xea000000, -8),      // b    (X-8)
4668     };
4669   
4670   // ARM/Thumb -> ARM long branch stub, PIC.  On V5T and above, use
4671   // blx to reach the stub if necessary.
4672   static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4673     {
4674       Insn_template::arm_insn(0xe59fc000),      // ldr   r12, [pc]
4675       Insn_template::arm_insn(0xe08ff00c),      // add   pc, pc, ip
4676       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4677                                                 // dcd   R_ARM_REL32(X-4)
4678     };
4679   
4680   // ARM/Thumb -> Thumb long branch stub, PIC.  On V5T and above, use
4681   // blx to reach the stub if necessary.  We can not add into pc;
4682   // it is not guaranteed to mode switch (different in ARMv6 and
4683   // ARMv7).
4684   static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4685     {
4686       Insn_template::arm_insn(0xe59fc004),      // ldr   r12, [pc, #4]
4687       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4688       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4689       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4690                                                 // dcd   R_ARM_REL32(X)
4691     };
4692   
4693   // V4T ARM -> ARM long branch stub, PIC.
4694   static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4695     {
4696       Insn_template::arm_insn(0xe59fc004),      // ldr   ip, [pc, #4]
4697       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4698       Insn_template::arm_insn(0xe12fff1c),      // bx    ip
4699       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4700                                                 // dcd   R_ARM_REL32(X)
4701     };
4702   
4703   // V4T Thumb -> ARM long branch stub, PIC.
4704   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4705     {
4706       Insn_template::thumb16_insn(0x4778),      // bx   pc
4707       Insn_template::thumb16_insn(0x46c0),      // nop
4708       Insn_template::arm_insn(0xe59fc000),      // ldr  ip, [pc, #0]
4709       Insn_template::arm_insn(0xe08cf00f),      // add  pc, ip, pc
4710       Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4711                                                 // dcd  R_ARM_REL32(X)
4712     };
4713   
4714   // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4715   // architectures.
4716   static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4717     {
4718       Insn_template::thumb16_insn(0xb401),      // push {r0}
4719       Insn_template::thumb16_insn(0x4802),      // ldr  r0, [pc, #8]
4720       Insn_template::thumb16_insn(0x46fc),      // mov  ip, pc
4721       Insn_template::thumb16_insn(0x4484),      // add  ip, r0
4722       Insn_template::thumb16_insn(0xbc01),      // pop  {r0}
4723       Insn_template::thumb16_insn(0x4760),      // bx   ip
4724       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4725                                                 // dcd  R_ARM_REL32(X)
4726     };
4727   
4728   // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4729   // allowed.
4730   static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4731     {
4732       Insn_template::thumb16_insn(0x4778),      // bx   pc
4733       Insn_template::thumb16_insn(0x46c0),      // nop
4734       Insn_template::arm_insn(0xe59fc004),      // ldr  ip, [pc, #4]
4735       Insn_template::arm_insn(0xe08fc00c),      // add   ip, pc, ip
4736       Insn_template::arm_insn(0xe12fff1c),      // bx   ip
4737       Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4738                                                 // dcd  R_ARM_REL32(X)
4739     };
4740   
4741   // Cortex-A8 erratum-workaround stubs.
4742   
4743   // Stub used for conditional branches (which may be beyond +/-1MB away,
4744   // so we can't use a conditional branch to reach this stub).
4745   
4746   // original code:
4747   //
4748   //    b<cond> X
4749   // after:
4750   //
4751   static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4752     {
4753       Insn_template::thumb16_bcond_insn(0xd001),        //      b<cond>.n true
4754       Insn_template::thumb32_b_insn(0xf000b800, -4),    //      b.w after
4755       Insn_template::thumb32_b_insn(0xf000b800, -4)     // true:
4756                                                         //      b.w X
4757     };
4758   
4759   // Stub used for b.w and bl.w instructions.
4760   
4761   static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4762     {
4763       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4764     };
4765   
4766   static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4767     {
4768       Insn_template::thumb32_b_insn(0xf000b800, -4)     // b.w dest
4769     };
4770   
4771   // Stub used for Thumb-2 blx.w instructions.  We modified the original blx.w
4772   // instruction (which switches to ARM mode) to point to this stub.  Jump to
4773   // the real destination using an ARM-mode branch.
4774   static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4775     {
4776       Insn_template::arm_rel_insn(0xea000000, -8)       // b dest
4777     };
4778
4779   // Stub used to provide an interworking for R_ARM_V4BX relocation
4780   // (bx r[n] instruction).
4781   static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4782     {
4783       Insn_template::arm_insn(0xe3100001),              // tst   r<n>, #1
4784       Insn_template::arm_insn(0x01a0f000),              // moveq pc, r<n>
4785       Insn_template::arm_insn(0xe12fff10)               // bx    r<n>
4786     };
4787
4788   // Fill in the stub template look-up table.  Stub templates are constructed
4789   // per instance of Stub_factory for fast look-up without locking
4790   // in a thread-enabled environment.
4791
4792   this->stub_templates_[arm_stub_none] =
4793     new Stub_template(arm_stub_none, NULL, 0);
4794
4795 #define DEF_STUB(x)     \
4796   do \
4797     { \
4798       size_t array_size \
4799         = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4800       Stub_type type = arm_stub_##x; \
4801       this->stub_templates_[type] = \
4802         new Stub_template(type, elf32_arm_stub_##x, array_size); \
4803     } \
4804   while (0);
4805
4806   DEF_STUBS
4807 #undef DEF_STUB
4808 }
4809
4810 // Stub_table methods.
4811
4812 // Removel all Cortex-A8 stub.
4813
4814 template<bool big_endian>
4815 void
4816 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4817 {
4818   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4819        p != this->cortex_a8_stubs_.end();
4820        ++p)
4821     delete p->second;
4822   this->cortex_a8_stubs_.clear();
4823 }
4824
4825 // Relocate one stub.  This is a helper for Stub_table::relocate_stubs().
4826
4827 template<bool big_endian>
4828 void
4829 Stub_table<big_endian>::relocate_stub(
4830     Stub* stub,
4831     const Relocate_info<32, big_endian>* relinfo,
4832     Target_arm<big_endian>* arm_target,
4833     Output_section* output_section,
4834     unsigned char* view,
4835     Arm_address address,
4836     section_size_type view_size)
4837 {
4838   const Stub_template* stub_template = stub->stub_template();
4839   if (stub_template->reloc_count() != 0)
4840     {
4841       // Adjust view to cover the stub only.
4842       section_size_type offset = stub->offset();
4843       section_size_type stub_size = stub_template->size();
4844       gold_assert(offset + stub_size <= view_size);
4845
4846       arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4847                                 address + offset, stub_size);
4848     }
4849 }
4850
4851 // Relocate all stubs in this stub table.
4852
4853 template<bool big_endian>
4854 void
4855 Stub_table<big_endian>::relocate_stubs(
4856     const Relocate_info<32, big_endian>* relinfo,
4857     Target_arm<big_endian>* arm_target,
4858     Output_section* output_section,
4859     unsigned char* view,
4860     Arm_address address,
4861     section_size_type view_size)
4862 {
4863   // If we are passed a view bigger than the stub table's.  we need to
4864   // adjust the view.
4865   gold_assert(address == this->address()
4866               && (view_size
4867                   == static_cast<section_size_type>(this->data_size())));
4868
4869   // Relocate all relocation stubs.
4870   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4871       p != this->reloc_stubs_.end();
4872       ++p)
4873     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4874                         address, view_size);
4875
4876   // Relocate all Cortex-A8 stubs.
4877   for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4878        p != this->cortex_a8_stubs_.end();
4879        ++p)
4880     this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4881                         address, view_size);
4882
4883   // Relocate all ARM V4BX stubs.
4884   for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4885        p != this->arm_v4bx_stubs_.end();
4886        ++p)
4887     {
4888       if (*p != NULL)
4889         this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4890                             address, view_size);
4891     }
4892 }
4893
4894 // Write out the stubs to file.
4895
4896 template<bool big_endian>
4897 void
4898 Stub_table<big_endian>::do_write(Output_file* of)
4899 {
4900   off_t offset = this->offset();
4901   const section_size_type oview_size =
4902     convert_to_section_size_type(this->data_size());
4903   unsigned char* const oview = of->get_output_view(offset, oview_size);
4904
4905   // Write relocation stubs.
4906   for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4907       p != this->reloc_stubs_.end();
4908       ++p)
4909     {
4910       Reloc_stub* stub = p->second;
4911       Arm_address address = this->address() + stub->offset();
4912       gold_assert(address
4913                   == align_address(address,
4914                                    stub->stub_template()->alignment()));
4915       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4916                   big_endian);
4917     }
4918
4919   // Write Cortex-A8 stubs.
4920   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4921        p != this->cortex_a8_stubs_.end();
4922        ++p)
4923     {
4924       Cortex_a8_stub* stub = p->second;
4925       Arm_address address = this->address() + stub->offset();
4926       gold_assert(address
4927                   == align_address(address,
4928                                    stub->stub_template()->alignment()));
4929       stub->write(oview + stub->offset(), stub->stub_template()->size(),
4930                   big_endian);
4931     }
4932
4933   // Write ARM V4BX relocation stubs.
4934   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4935        p != this->arm_v4bx_stubs_.end();
4936        ++p)
4937     {
4938       if (*p == NULL)
4939         continue;
4940
4941       Arm_address address = this->address() + (*p)->offset();
4942       gold_assert(address
4943                   == align_address(address,
4944                                    (*p)->stub_template()->alignment()));
4945       (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4946                   big_endian);
4947     }
4948
4949   of->write_output_view(this->offset(), oview_size, oview);
4950 }
4951
4952 // Update the data size and address alignment of the stub table at the end
4953 // of a relaxation pass.   Return true if either the data size or the
4954 // alignment changed in this relaxation pass.
4955
4956 template<bool big_endian>
4957 bool
4958 Stub_table<big_endian>::update_data_size_and_addralign()
4959 {
4960   // Go over all stubs in table to compute data size and address alignment.
4961   off_t size = this->reloc_stubs_size_;
4962   unsigned addralign = this->reloc_stubs_addralign_;
4963
4964   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4965        p != this->cortex_a8_stubs_.end();
4966        ++p)
4967     {
4968       const Stub_template* stub_template = p->second->stub_template();
4969       addralign = std::max(addralign, stub_template->alignment());
4970       size = (align_address(size, stub_template->alignment())
4971               + stub_template->size());
4972     }
4973
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       const Stub_template* stub_template = (*p)->stub_template();
4982       addralign = std::max(addralign, stub_template->alignment());
4983       size = (align_address(size, stub_template->alignment())
4984               + stub_template->size());
4985     }
4986
4987   // Check if either data size or alignment changed in this pass.
4988   // Update prev_data_size_ and prev_addralign_.  These will be used
4989   // as the current data size and address alignment for the next pass.
4990   bool changed = size != this->prev_data_size_;
4991   this->prev_data_size_ = size; 
4992
4993   if (addralign != this->prev_addralign_)
4994     changed = true;
4995   this->prev_addralign_ = addralign;
4996
4997   return changed;
4998 }
4999
5000 // Finalize the stubs.  This sets the offsets of the stubs within the stub
5001 // table.  It also marks all input sections needing Cortex-A8 workaround.
5002
5003 template<bool big_endian>
5004 void
5005 Stub_table<big_endian>::finalize_stubs()
5006 {
5007   off_t off = this->reloc_stubs_size_;
5008   for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5009        p != this->cortex_a8_stubs_.end();
5010        ++p)
5011     {
5012       Cortex_a8_stub* stub = p->second;
5013       const Stub_template* stub_template = stub->stub_template();
5014       uint64_t stub_addralign = stub_template->alignment();
5015       off = align_address(off, stub_addralign);
5016       stub->set_offset(off);
5017       off += stub_template->size();
5018
5019       // Mark input section so that we can determine later if a code section
5020       // needs the Cortex-A8 workaround quickly.
5021       Arm_relobj<big_endian>* arm_relobj =
5022         Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5023       arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5024     }
5025
5026   for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5027       p != this->arm_v4bx_stubs_.end();
5028       ++p)
5029     {
5030       if (*p == NULL)
5031         continue;
5032
5033       const Stub_template* stub_template = (*p)->stub_template();
5034       uint64_t stub_addralign = stub_template->alignment();
5035       off = align_address(off, stub_addralign);
5036       (*p)->set_offset(off);
5037       off += stub_template->size();
5038     }
5039
5040   gold_assert(off <= this->prev_data_size_);
5041 }
5042
5043 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5044 // and VIEW_ADDRESS + VIEW_SIZE - 1.  VIEW points to the mapped address
5045 // of the address range seen by the linker.
5046
5047 template<bool big_endian>
5048 void
5049 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5050     Target_arm<big_endian>* arm_target,
5051     unsigned char* view,
5052     Arm_address view_address,
5053     section_size_type view_size)
5054 {
5055   // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5056   for (Cortex_a8_stub_list::const_iterator p =
5057          this->cortex_a8_stubs_.lower_bound(view_address);
5058        ((p != this->cortex_a8_stubs_.end())
5059         && (p->first < (view_address + view_size)));
5060        ++p)
5061     {
5062       // We do not store the THUMB bit in the LSB of either the branch address
5063       // or the stub offset.  There is no need to strip the LSB.
5064       Arm_address branch_address = p->first;
5065       const Cortex_a8_stub* stub = p->second;
5066       Arm_address stub_address = this->address() + stub->offset();
5067
5068       // Offset of the branch instruction relative to this view.
5069       section_size_type offset =
5070         convert_to_section_size_type(branch_address - view_address);
5071       gold_assert((offset + 4) <= view_size);
5072
5073       arm_target->apply_cortex_a8_workaround(stub, stub_address,
5074                                              view + offset, branch_address);
5075     }
5076 }
5077
5078 // Arm_input_section methods.
5079
5080 // Initialize an Arm_input_section.
5081
5082 template<bool big_endian>
5083 void
5084 Arm_input_section<big_endian>::init()
5085 {
5086   Relobj* relobj = this->relobj();
5087   unsigned int shndx = this->shndx();
5088
5089   // Cache these to speed up size and alignment queries.  It is too slow
5090   // to call section_addraglin and section_size every time.
5091   this->original_addralign_ =
5092     convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5093   this->original_size_ =
5094     convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5095
5096   // We want to make this look like the original input section after
5097   // output sections are finalized.
5098   Output_section* os = relobj->output_section(shndx);
5099   off_t offset = relobj->output_section_offset(shndx);
5100   gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5101   this->set_address(os->address() + offset);
5102   this->set_file_offset(os->offset() + offset);
5103
5104   this->set_current_data_size(this->original_size_);
5105   this->finalize_data_size();
5106 }
5107
5108 template<bool big_endian>
5109 void
5110 Arm_input_section<big_endian>::do_write(Output_file* of)
5111 {
5112   // We have to write out the original section content.
5113   section_size_type section_size;
5114   const unsigned char* section_contents =
5115     this->relobj()->section_contents(this->shndx(), &section_size, false); 
5116   of->write(this->offset(), section_contents, section_size); 
5117
5118   // If this owns a stub table and it is not empty, write it.
5119   if (this->is_stub_table_owner() && !this->stub_table_->empty())
5120     this->stub_table_->write(of);
5121 }
5122
5123 // Finalize data size.
5124
5125 template<bool big_endian>
5126 void
5127 Arm_input_section<big_endian>::set_final_data_size()
5128 {
5129   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5130
5131   if (this->is_stub_table_owner())
5132     {
5133       this->stub_table_->finalize_data_size();
5134       off = align_address(off, this->stub_table_->addralign());
5135       off += this->stub_table_->data_size();
5136     }
5137   this->set_data_size(off);
5138 }
5139
5140 // Reset address and file offset.
5141
5142 template<bool big_endian>
5143 void
5144 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5145 {
5146   // Size of the original input section contents.
5147   off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5148
5149   // If this is a stub table owner, account for the stub table size.
5150   if (this->is_stub_table_owner())
5151     {
5152       Stub_table<big_endian>* stub_table = this->stub_table_;
5153
5154       // Reset the stub table's address and file offset.  The
5155       // current data size for child will be updated after that.
5156       stub_table_->reset_address_and_file_offset();
5157       off = align_address(off, stub_table_->addralign());
5158       off += stub_table->current_data_size();
5159     }
5160
5161   this->set_current_data_size(off);
5162 }
5163
5164 // Arm_exidx_cantunwind methods.
5165
5166 // Write this to Output file OF for a fixed endianness.
5167
5168 template<bool big_endian>
5169 void
5170 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5171 {
5172   off_t offset = this->offset();
5173   const section_size_type oview_size = 8;
5174   unsigned char* const oview = of->get_output_view(offset, oview_size);
5175   
5176   typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5177   Valtype* wv = reinterpret_cast<Valtype*>(oview);
5178
5179   Output_section* os = this->relobj_->output_section(this->shndx_);
5180   gold_assert(os != NULL);
5181
5182   Arm_relobj<big_endian>* arm_relobj =
5183     Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5184   Arm_address output_offset =
5185     arm_relobj->get_output_section_offset(this->shndx_);
5186   Arm_address section_start;
5187   if (output_offset != Arm_relobj<big_endian>::invalid_address)
5188     section_start = os->address() + output_offset;
5189   else
5190     {
5191       // Currently this only happens for a relaxed section.
5192       const Output_relaxed_input_section* poris =
5193         os->find_relaxed_input_section(this->relobj_, this->shndx_);
5194       gold_assert(poris != NULL);
5195       section_start = poris->address();
5196     }
5197
5198   // We always append this to the end of an EXIDX section.
5199   Arm_address output_address =
5200     section_start + this->relobj_->section_size(this->shndx_);
5201
5202   // Write out the entry.  The first word either points to the beginning
5203   // or after the end of a text section.  The second word is the special
5204   // EXIDX_CANTUNWIND value.
5205   uint32_t prel31_offset = output_address - this->address();
5206   if (utils::has_overflow<31>(offset))
5207     gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5208   elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
5209   elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5210
5211   of->write_output_view(this->offset(), oview_size, oview);
5212 }
5213
5214 // Arm_exidx_merged_section methods.
5215
5216 // Constructor for Arm_exidx_merged_section.
5217 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5218 // SECTION_OFFSET_MAP points to a section offset map describing how
5219 // parts of the input section are mapped to output.  DELETED_BYTES is
5220 // the number of bytes deleted from the EXIDX input section.
5221
5222 Arm_exidx_merged_section::Arm_exidx_merged_section(
5223     const Arm_exidx_input_section& exidx_input_section,
5224     const Arm_exidx_section_offset_map& section_offset_map,
5225     uint32_t deleted_bytes)
5226   : Output_relaxed_input_section(exidx_input_section.relobj(),
5227                                  exidx_input_section.shndx(),
5228                                  exidx_input_section.addralign()),
5229     exidx_input_section_(exidx_input_section),
5230     section_offset_map_(section_offset_map)
5231 {
5232   // Fix size here so that we do not need to implement set_final_data_size.
5233   this->set_data_size(exidx_input_section.size() - deleted_bytes);
5234   this->fix_data_size();
5235 }
5236
5237 // Given an input OBJECT, an input section index SHNDX within that
5238 // object, and an OFFSET relative to the start of that input
5239 // section, return whether or not the corresponding offset within
5240 // the output section is known.  If this function returns true, it
5241 // sets *POUTPUT to the output offset.  The value -1 indicates that
5242 // this input offset is being discarded.
5243
5244 bool
5245 Arm_exidx_merged_section::do_output_offset(
5246     const Relobj* relobj,
5247     unsigned int shndx,
5248     section_offset_type offset,
5249     section_offset_type* poutput) const
5250 {
5251   // We only handle offsets for the original EXIDX input section.
5252   if (relobj != this->exidx_input_section_.relobj()
5253       || shndx != this->exidx_input_section_.shndx())
5254     return false;
5255
5256   section_offset_type section_size =
5257     convert_types<section_offset_type>(this->exidx_input_section_.size());
5258   if (offset < 0 || offset >= section_size)
5259     // Input offset is out of valid range.
5260     *poutput = -1;
5261   else
5262     {
5263       // We need to look up the section offset map to determine the output
5264       // offset.  Find the reference point in map that is first offset
5265       // bigger than or equal to this offset.
5266       Arm_exidx_section_offset_map::const_iterator p =
5267         this->section_offset_map_.lower_bound(offset);
5268
5269       // The section offset maps are build such that this should not happen if
5270       // input offset is in the valid range.
5271       gold_assert(p != this->section_offset_map_.end());
5272
5273       // We need to check if this is dropped.
5274      section_offset_type ref = p->first;
5275      section_offset_type mapped_ref = p->second;
5276
5277       if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5278         // Offset is present in output.
5279         *poutput = mapped_ref + (offset - ref);
5280       else
5281         // Offset is discarded owing to EXIDX entry merging.
5282         *poutput = -1;
5283     }
5284   
5285   return true;
5286 }
5287
5288 // Write this to output file OF.
5289
5290 void
5291 Arm_exidx_merged_section::do_write(Output_file* of)
5292 {
5293   // If we retain or discard the whole EXIDX input section,  we would
5294   // not be here.
5295   gold_assert(this->data_size() != this->exidx_input_section_.size()
5296               && this->data_size() != 0);
5297
5298   off_t offset = this->offset();
5299   const section_size_type oview_size = this->data_size();
5300   unsigned char* const oview = of->get_output_view(offset, oview_size);
5301   
5302   Output_section* os = this->relobj()->output_section(this->shndx());
5303   gold_assert(os != NULL);
5304
5305   // Get contents of EXIDX input section.
5306   section_size_type section_size;
5307   const unsigned char* section_contents =
5308     this->relobj()->section_contents(this->shndx(), &section_size, false); 
5309   gold_assert(section_size == this->exidx_input_section_.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   for(Arm_exidx_section_offset_map::const_iterator p =
5316         this->section_offset_map_.begin();
5317       p != this->section_offset_map_.end();
5318       ++p)
5319     {
5320       section_offset_type in_end = p->first;
5321       gold_assert(in_end >= in_start);
5322       section_offset_type out_end = p->second;
5323       size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5324       if (out_end != -1)
5325         {
5326           size_t out_chunk_size =
5327             convert_types<size_t>(out_end - out_start + 1);
5328           gold_assert(out_chunk_size == in_chunk_size);
5329           memcpy(oview + out_start, section_contents + in_start,
5330                  out_chunk_size);
5331           out_start += out_chunk_size;
5332         }
5333       in_start += in_chunk_size;
5334     }
5335
5336   gold_assert(convert_to_section_size_type(out_start) == oview_size);
5337   of->write_output_view(this->offset(), oview_size, oview);
5338 }
5339
5340 // Arm_exidx_fixup methods.
5341
5342 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5343 // is not an EXIDX_CANTUNWIND entry already.  The new EXIDX_CANTUNWIND entry
5344 // points to the end of the last seen EXIDX section.
5345
5346 void
5347 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5348 {
5349   if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5350       && this->last_input_section_ != NULL)
5351     {
5352       Relobj* relobj = this->last_input_section_->relobj();
5353       unsigned int text_shndx = this->last_input_section_->link();
5354       Arm_exidx_cantunwind* cantunwind =
5355         new Arm_exidx_cantunwind(relobj, text_shndx);
5356       this->exidx_output_section_->add_output_section_data(cantunwind);
5357       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5358     }
5359 }
5360
5361 // Process an EXIDX section entry in input.  Return whether this entry
5362 // can be deleted in the output.  SECOND_WORD in the second word of the
5363 // EXIDX entry.
5364
5365 bool
5366 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5367 {
5368   bool delete_entry;
5369   if (second_word == elfcpp::EXIDX_CANTUNWIND)
5370     {
5371       // Merge if previous entry is also an EXIDX_CANTUNWIND.
5372       delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5373       this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5374     }
5375   else if ((second_word & 0x80000000) != 0)
5376     {
5377       // Inlined unwinding data.  Merge if equal to previous.
5378       delete_entry = (merge_exidx_entries_
5379                       && this->last_unwind_type_ == UT_INLINED_ENTRY
5380                       && this->last_inlined_entry_ == second_word);
5381       this->last_unwind_type_ = UT_INLINED_ENTRY;
5382       this->last_inlined_entry_ = second_word;
5383     }
5384   else
5385     {
5386       // Normal table entry.  In theory we could merge these too,
5387       // but duplicate entries are likely to be much less common.
5388       delete_entry = false;
5389       this->last_unwind_type_ = UT_NORMAL_ENTRY;
5390     }
5391   return delete_entry;
5392 }
5393
5394 // Update the current section offset map during EXIDX section fix-up.
5395 // If there is no map, create one.  INPUT_OFFSET is the offset of a
5396 // reference point, DELETED_BYTES is the number of deleted by in the
5397 // section so far.  If DELETE_ENTRY is true, the reference point and
5398 // all offsets after the previous reference point are discarded.
5399
5400 void
5401 Arm_exidx_fixup::update_offset_map(
5402     section_offset_type input_offset,
5403     section_size_type deleted_bytes,
5404     bool delete_entry)
5405 {
5406   if (this->section_offset_map_ == NULL)
5407     this->section_offset_map_ = new Arm_exidx_section_offset_map();
5408   section_offset_type output_offset;
5409   if (delete_entry)
5410     output_offset = Arm_exidx_input_section::invalid_offset;
5411   else
5412     output_offset = input_offset - deleted_bytes;
5413   (*this->section_offset_map_)[input_offset] = output_offset;
5414 }
5415
5416 // Process EXIDX_INPUT_SECTION for EXIDX entry merging.  Return the number of
5417 // bytes deleted.  If some entries are merged, also store a pointer to a newly
5418 // created Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP.  The
5419 // caller owns the map and is responsible for releasing it after use.
5420
5421 template<bool big_endian>
5422 uint32_t
5423 Arm_exidx_fixup::process_exidx_section(
5424     const Arm_exidx_input_section* exidx_input_section,
5425     Arm_exidx_section_offset_map** psection_offset_map)
5426 {
5427   Relobj* relobj = exidx_input_section->relobj();
5428   unsigned shndx = exidx_input_section->shndx();
5429   section_size_type section_size;
5430   const unsigned char* section_contents =
5431     relobj->section_contents(shndx, &section_size, false);
5432
5433   if ((section_size % 8) != 0)
5434     {
5435       // Something is wrong with this section.  Better not touch it.
5436       gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5437                  relobj->name().c_str(), shndx);
5438       this->last_input_section_ = exidx_input_section;
5439       this->last_unwind_type_ = UT_NONE;
5440       return 0;
5441     }
5442   
5443   uint32_t deleted_bytes = 0;
5444   bool prev_delete_entry = false;
5445   gold_assert(this->section_offset_map_ == NULL);
5446
5447   for (section_size_type i = 0; i < section_size; i += 8)
5448     {
5449       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5450       const Valtype* wv =
5451           reinterpret_cast<const Valtype*>(section_contents + i + 4);
5452       uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5453
5454       bool delete_entry = this->process_exidx_entry(second_word);
5455
5456       // Entry deletion causes changes in output offsets.  We use a std::map
5457       // to record these.  And entry (x, y) means input offset x
5458       // is mapped to output offset y.  If y is invalid_offset, then x is
5459       // dropped in the output.  Because of the way std::map::lower_bound
5460       // works, we record the last offset in a region w.r.t to keeping or
5461       // dropping.  If there is no entry (x0, y0) for an input offset x0,
5462       // the output offset y0 of it is determined by the output offset y1 of
5463       // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5464       // in the map.  If y1 is not -1, then y0 = y1 + x0 - x1.  Othewise, y1
5465       // y0 is also -1.
5466       if (delete_entry != prev_delete_entry && i != 0)
5467         this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5468
5469       // Update total deleted bytes for this entry.
5470       if (delete_entry)
5471         deleted_bytes += 8;
5472
5473       prev_delete_entry = delete_entry;
5474     }
5475   
5476   // If section offset map is not NULL, make an entry for the end of
5477   // section.
5478   if (this->section_offset_map_ != NULL)
5479     update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5480
5481   *psection_offset_map = this->section_offset_map_;
5482   this->section_offset_map_ = NULL;
5483   this->last_input_section_ = exidx_input_section;
5484   
5485   // Set the first output text section so that we can link the EXIDX output
5486   // section to it.  Ignore any EXIDX input section that is completely merged.
5487   if (this->first_output_text_section_ == NULL
5488       && deleted_bytes != section_size)
5489     {
5490       unsigned int link = exidx_input_section->link();
5491       Output_section* os = relobj->output_section(link);
5492       gold_assert(os != NULL);
5493       this->first_output_text_section_ = os;
5494     }
5495
5496   return deleted_bytes;
5497 }
5498
5499 // Arm_output_section methods.
5500
5501 // Create a stub group for input sections from BEGIN to END.  OWNER
5502 // points to the input section to be the owner a new stub table.
5503
5504 template<bool big_endian>
5505 void
5506 Arm_output_section<big_endian>::create_stub_group(
5507   Input_section_list::const_iterator begin,
5508   Input_section_list::const_iterator end,
5509   Input_section_list::const_iterator owner,
5510   Target_arm<big_endian>* target,
5511   std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
5512 {
5513   // We use a different kind of relaxed section in an EXIDX section.
5514   // The static casting from Output_relaxed_input_section to
5515   // Arm_input_section is invalid in an EXIDX section.  We are okay
5516   // because we should not be calling this for an EXIDX section. 
5517   gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5518
5519   // Currently we convert ordinary input sections into relaxed sections only
5520   // at this point but we may want to support creating relaxed input section
5521   // very early.  So we check here to see if owner is already a relaxed
5522   // section.
5523   
5524   Arm_input_section<big_endian>* arm_input_section;
5525   if (owner->is_relaxed_input_section())
5526     {
5527       arm_input_section =
5528         Arm_input_section<big_endian>::as_arm_input_section(
5529           owner->relaxed_input_section());
5530     }
5531   else
5532     {
5533       gold_assert(owner->is_input_section());
5534       // Create a new relaxed input section.
5535       arm_input_section =
5536         target->new_arm_input_section(owner->relobj(), owner->shndx());
5537       new_relaxed_sections->push_back(arm_input_section);
5538     }
5539
5540   // Create a stub table.
5541   Stub_table<big_endian>* stub_table =
5542     target->new_stub_table(arm_input_section);
5543
5544   arm_input_section->set_stub_table(stub_table);
5545   
5546   Input_section_list::const_iterator p = begin;
5547   Input_section_list::const_iterator prev_p;
5548
5549   // Look for input sections or relaxed input sections in [begin ... end].
5550   do
5551     {
5552       if (p->is_input_section() || p->is_relaxed_input_section())
5553         {
5554           // The stub table information for input sections live
5555           // in their objects.
5556           Arm_relobj<big_endian>* arm_relobj =
5557             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5558           arm_relobj->set_stub_table(p->shndx(), stub_table);
5559         }
5560       prev_p = p++;
5561     }
5562   while (prev_p != end);
5563 }
5564
5565 // Group input sections for stub generation.  GROUP_SIZE is roughly the limit
5566 // of stub groups.  We grow a stub group by adding input section until the
5567 // size is just below GROUP_SIZE.  The last input section will be converted
5568 // into a stub table.  If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5569 // input section after the stub table, effectively double the group size.
5570 // 
5571 // This is similar to the group_sections() function in elf32-arm.c but is
5572 // implemented differently.
5573
5574 template<bool big_endian>
5575 void
5576 Arm_output_section<big_endian>::group_sections(
5577     section_size_type group_size,
5578     bool stubs_always_after_branch,
5579     Target_arm<big_endian>* target)
5580 {
5581   // We only care about sections containing code.
5582   if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5583     return;
5584
5585   // States for grouping.
5586   typedef enum
5587   {
5588     // No group is being built.
5589     NO_GROUP,
5590     // A group is being built but the stub table is not found yet.
5591     // We keep group a stub group until the size is just under GROUP_SIZE.
5592     // The last input section in the group will be used as the stub table.
5593     FINDING_STUB_SECTION,
5594     // A group is being built and we have already found a stub table.
5595     // We enter this state to grow a stub group by adding input section
5596     // after the stub table.  This effectively doubles the group size.
5597     HAS_STUB_SECTION
5598   } State;
5599
5600   // Any newly created relaxed sections are stored here.
5601   std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5602
5603   State state = NO_GROUP;
5604   section_size_type off = 0;
5605   section_size_type group_begin_offset = 0;
5606   section_size_type group_end_offset = 0;
5607   section_size_type stub_table_end_offset = 0;
5608   Input_section_list::const_iterator group_begin =
5609     this->input_sections().end();
5610   Input_section_list::const_iterator stub_table =
5611     this->input_sections().end();
5612   Input_section_list::const_iterator group_end = this->input_sections().end();
5613   for (Input_section_list::const_iterator p = this->input_sections().begin();
5614        p != this->input_sections().end();
5615        ++p)
5616     {
5617       section_size_type section_begin_offset =
5618         align_address(off, p->addralign());
5619       section_size_type section_end_offset =
5620         section_begin_offset + p->data_size(); 
5621       
5622       // Check to see if we should group the previously seens sections.
5623       switch (state)
5624         {
5625         case NO_GROUP:
5626           break;
5627
5628         case FINDING_STUB_SECTION:
5629           // Adding this section makes the group larger than GROUP_SIZE.
5630           if (section_end_offset - group_begin_offset >= group_size)
5631             {
5632               if (stubs_always_after_branch)
5633                 {       
5634                   gold_assert(group_end != this->input_sections().end());
5635                   this->create_stub_group(group_begin, group_end, group_end,
5636                                           target, &new_relaxed_sections);
5637                   state = NO_GROUP;
5638                 }
5639               else
5640                 {
5641                   // But wait, there's more!  Input sections up to
5642                   // stub_group_size bytes after the stub table can be
5643                   // handled by it too.
5644                   state = HAS_STUB_SECTION;
5645                   stub_table = group_end;
5646                   stub_table_end_offset = group_end_offset;
5647                 }
5648             }
5649             break;
5650
5651         case HAS_STUB_SECTION:
5652           // Adding this section makes the post stub-section group larger
5653           // than GROUP_SIZE.
5654           if (section_end_offset - stub_table_end_offset >= group_size)
5655            {
5656              gold_assert(group_end != this->input_sections().end());
5657              this->create_stub_group(group_begin, group_end, stub_table,
5658                                      target, &new_relaxed_sections);
5659              state = NO_GROUP;
5660            }
5661            break;
5662
5663           default:
5664             gold_unreachable();
5665         }       
5666
5667       // If we see an input section and currently there is no group, start
5668       // a new one.  Skip any empty sections.
5669       if ((p->is_input_section() || p->is_relaxed_input_section())
5670           && (p->relobj()->section_size(p->shndx()) != 0))
5671         {
5672           if (state == NO_GROUP)
5673             {
5674               state = FINDING_STUB_SECTION;
5675               group_begin = p;
5676               group_begin_offset = section_begin_offset;
5677             }
5678
5679           // Keep track of the last input section seen.
5680           group_end = p;
5681           group_end_offset = section_end_offset;
5682         }
5683
5684       off = section_end_offset;
5685     }
5686
5687   // Create a stub group for any ungrouped sections.
5688   if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5689     {
5690       gold_assert(group_end != this->input_sections().end());
5691       this->create_stub_group(group_begin, group_end,
5692                               (state == FINDING_STUB_SECTION
5693                                ? group_end
5694                                : stub_table),
5695                                target, &new_relaxed_sections);
5696     }
5697
5698   // Convert input section into relaxed input section in a batch.
5699   if (!new_relaxed_sections.empty())
5700     this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5701
5702   // Update the section offsets
5703   for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5704     {
5705       Arm_relobj<big_endian>* arm_relobj =
5706         Arm_relobj<big_endian>::as_arm_relobj(
5707           new_relaxed_sections[i]->relobj());
5708       unsigned int shndx = new_relaxed_sections[i]->shndx();
5709       // Tell Arm_relobj that this input section is converted.
5710       arm_relobj->convert_input_section_to_relaxed_section(shndx);
5711     }
5712 }
5713
5714 // Append non empty text sections in this to LIST in ascending
5715 // order of their position in this.
5716
5717 template<bool big_endian>
5718 void
5719 Arm_output_section<big_endian>::append_text_sections_to_list(
5720     Text_section_list* list)
5721 {
5722   gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5723
5724   for (Input_section_list::const_iterator p = this->input_sections().begin();
5725        p != this->input_sections().end();
5726        ++p)
5727     {
5728       // We only care about plain or relaxed input sections.  We also
5729       // ignore any merged sections.
5730       if ((p->is_input_section() || p->is_relaxed_input_section())
5731           && p->data_size() != 0)
5732         list->push_back(Text_section_list::value_type(p->relobj(),
5733                                                       p->shndx()));
5734     }
5735 }
5736
5737 template<bool big_endian>
5738 void
5739 Arm_output_section<big_endian>::fix_exidx_coverage(
5740     Layout* layout,
5741     const Text_section_list& sorted_text_sections,
5742     Symbol_table* symtab,
5743     bool merge_exidx_entries)
5744 {
5745   // We should only do this for the EXIDX output section.
5746   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5747
5748   // We don't want the relaxation loop to undo these changes, so we discard
5749   // the current saved states and take another one after the fix-up.
5750   this->discard_states();
5751
5752   // Remove all input sections.
5753   uint64_t address = this->address();
5754   typedef std::list<Output_section::Input_section> Input_section_list;
5755   Input_section_list input_sections;
5756   this->reset_address_and_file_offset();
5757   this->get_input_sections(address, std::string(""), &input_sections);
5758
5759   if (!this->input_sections().empty())
5760     gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5761   
5762   // Go through all the known input sections and record them.
5763   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5764   typedef Unordered_map<Section_id, const Output_section::Input_section*,
5765                         Section_id_hash> Text_to_exidx_map;
5766   Text_to_exidx_map text_to_exidx_map;
5767   for (Input_section_list::const_iterator p = input_sections.begin();
5768        p != input_sections.end();
5769        ++p)
5770     {
5771       // This should never happen.  At this point, we should only see
5772       // plain EXIDX input sections.
5773       gold_assert(!p->is_relaxed_input_section());
5774       text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5775     }
5776
5777   Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5778
5779   // Go over the sorted text sections.
5780   typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5781   Section_id_set processed_input_sections;
5782   for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5783        p != sorted_text_sections.end();
5784        ++p)
5785     {
5786       Relobj* relobj = p->first;
5787       unsigned int shndx = p->second;
5788
5789       Arm_relobj<big_endian>* arm_relobj =
5790          Arm_relobj<big_endian>::as_arm_relobj(relobj);
5791       const Arm_exidx_input_section* exidx_input_section =
5792          arm_relobj->exidx_input_section_by_link(shndx);
5793
5794       // If this text section has no EXIDX section or if the EXIDX section
5795       // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5796       // of the last seen EXIDX section.
5797       if (exidx_input_section == NULL || exidx_input_section->has_errors())
5798         {
5799           exidx_fixup.add_exidx_cantunwind_as_needed();
5800           continue;
5801         }
5802
5803       Relobj* exidx_relobj = exidx_input_section->relobj();
5804       unsigned int exidx_shndx = exidx_input_section->shndx();
5805       Section_id sid(exidx_relobj, exidx_shndx);
5806       Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5807       if (iter == text_to_exidx_map.end())
5808         {
5809           // This is odd.  We have not seen this EXIDX input section before.
5810           // We cannot do fix-up.  If we saw a SECTIONS clause in a script,
5811           // issue a warning instead.  We assume the user knows what he
5812           // or she is doing.  Otherwise, this is an error.
5813           if (layout->script_options()->saw_sections_clause())
5814             gold_warning(_("unwinding may not work because EXIDX input section"
5815                            " %u of %s is not in EXIDX output section"),
5816                          exidx_shndx, exidx_relobj->name().c_str());
5817           else
5818             gold_error(_("unwinding may not work because EXIDX input section"
5819                          " %u of %s is not in EXIDX output section"),
5820                        exidx_shndx, exidx_relobj->name().c_str());
5821
5822           exidx_fixup.add_exidx_cantunwind_as_needed();
5823           continue;
5824         }
5825
5826       // Fix up coverage and append input section to output data list.
5827       Arm_exidx_section_offset_map* section_offset_map = NULL;
5828       uint32_t deleted_bytes =
5829         exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5830                                                       &section_offset_map);
5831
5832       if (deleted_bytes == exidx_input_section->size())
5833         {
5834           // The whole EXIDX section got merged.  Remove it from output.
5835           gold_assert(section_offset_map == NULL);
5836           exidx_relobj->set_output_section(exidx_shndx, NULL);
5837
5838           // All local symbols defined in this input section will be dropped.
5839           // We need to adjust output local symbol count.
5840           arm_relobj->set_output_local_symbol_count_needs_update();
5841         }
5842       else if (deleted_bytes > 0)
5843         {
5844           // Some entries are merged.  We need to convert this EXIDX input
5845           // section into a relaxed section.
5846           gold_assert(section_offset_map != NULL);
5847           Arm_exidx_merged_section* merged_section =
5848             new Arm_exidx_merged_section(*exidx_input_section,
5849                                          *section_offset_map, deleted_bytes);
5850           const std::string secname = exidx_relobj->section_name(exidx_shndx);
5851           this->add_relaxed_input_section(layout, merged_section, secname);
5852           arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5853
5854           // All local symbols defined in discarded portions of this input
5855           // section will be dropped.  We need to adjust output local symbol
5856           // count.
5857           arm_relobj->set_output_local_symbol_count_needs_update();
5858         }
5859       else
5860         {
5861           // Just add back the EXIDX input section.
5862           gold_assert(section_offset_map == NULL);
5863           const Output_section::Input_section* pis = iter->second;
5864           gold_assert(pis->is_input_section());
5865           this->add_script_input_section(*pis);
5866         }
5867
5868       processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx)); 
5869     }
5870
5871   // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5872   exidx_fixup.add_exidx_cantunwind_as_needed();
5873
5874   // Remove any known EXIDX input sections that are not processed.
5875   for (Input_section_list::const_iterator p = input_sections.begin();
5876        p != input_sections.end();
5877        ++p)
5878     {
5879       if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5880           == processed_input_sections.end())
5881         {
5882           // We discard a known EXIDX section because its linked
5883           // text section has been folded by ICF.  We also discard an
5884           // EXIDX section with error, the output does not matter in this
5885           // case.  We do this to avoid triggering asserts.
5886           Arm_relobj<big_endian>* arm_relobj =
5887             Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5888           const Arm_exidx_input_section* exidx_input_section =
5889             arm_relobj->exidx_input_section_by_shndx(p->shndx());
5890           gold_assert(exidx_input_section != NULL);
5891           if (!exidx_input_section->has_errors())
5892             {
5893               unsigned int text_shndx = exidx_input_section->link();
5894               gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5895             }
5896
5897           // Remove this from link.  We also need to recount the
5898           // local symbols.
5899           p->relobj()->set_output_section(p->shndx(), NULL);
5900           arm_relobj->set_output_local_symbol_count_needs_update();
5901         }
5902     }
5903     
5904   // Link exidx output section to the first seen output section and
5905   // set correct entry size.
5906   this->set_link_section(exidx_fixup.first_output_text_section());
5907   this->set_entsize(8);
5908
5909   // Make changes permanent.
5910   this->save_states();
5911   this->set_section_offsets_need_adjustment();
5912 }
5913
5914 // Link EXIDX output sections to text output sections.
5915
5916 template<bool big_endian>
5917 void
5918 Arm_output_section<big_endian>::set_exidx_section_link()
5919 {
5920   gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5921   if (!this->input_sections().empty())
5922     {
5923       Input_section_list::const_iterator p = this->input_sections().begin();
5924       Arm_relobj<big_endian>* arm_relobj =
5925         Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5926       unsigned exidx_shndx = p->shndx();
5927       const Arm_exidx_input_section* exidx_input_section =
5928         arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
5929       gold_assert(exidx_input_section != NULL);
5930       unsigned int text_shndx = exidx_input_section->link();
5931       Output_section* os = arm_relobj->output_section(text_shndx);
5932       this->set_link_section(os);
5933     }
5934 }
5935
5936 // Arm_relobj methods.
5937
5938 // Determine if an input section is scannable for stub processing.  SHDR is
5939 // the header of the section and SHNDX is the section index.  OS is the output
5940 // section for the input section and SYMTAB is the global symbol table used to
5941 // look up ICF information.
5942
5943 template<bool big_endian>
5944 bool
5945 Arm_relobj<big_endian>::section_is_scannable(
5946     const elfcpp::Shdr<32, big_endian>& shdr,
5947     unsigned int shndx,
5948     const Output_section* os,
5949     const Symbol_table* symtab)
5950 {
5951   // Skip any empty sections, unallocated sections or sections whose
5952   // type are not SHT_PROGBITS.
5953   if (shdr.get_sh_size() == 0
5954       || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
5955       || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
5956     return false;
5957
5958   // Skip any discarded or ICF'ed sections.
5959   if (os == NULL || symtab->is_section_folded(this, shndx))
5960     return false;
5961
5962   // If this requires special offset handling, check to see if it is
5963   // a relaxed section.  If this is not, then it is a merged section that
5964   // we cannot handle.
5965   if (this->is_output_section_offset_invalid(shndx))
5966     {
5967       const Output_relaxed_input_section* poris =
5968         os->find_relaxed_input_section(this, shndx);
5969       if (poris == NULL)
5970         return false;
5971     }
5972
5973   return true;
5974 }
5975
5976 // Determine if we want to scan the SHNDX-th section for relocation stubs.
5977 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5978
5979 template<bool big_endian>
5980 bool
5981 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
5982     const elfcpp::Shdr<32, big_endian>& shdr,
5983     const Relobj::Output_sections& out_sections,
5984     const Symbol_table* symtab,
5985     const unsigned char* pshdrs)
5986 {
5987   unsigned int sh_type = shdr.get_sh_type();
5988   if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
5989     return false;
5990
5991   // Ignore empty section.
5992   off_t sh_size = shdr.get_sh_size();
5993   if (sh_size == 0)
5994     return false;
5995
5996   // Ignore reloc section with unexpected symbol table.  The
5997   // error will be reported in the final link.
5998   if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
5999     return false;
6000
6001   unsigned int reloc_size;
6002   if (sh_type == elfcpp::SHT_REL)
6003     reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6004   else
6005     reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6006
6007   // Ignore reloc section with unexpected entsize or uneven size.
6008   // The error will be reported in the final link.
6009   if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6010     return false;
6011
6012   // Ignore reloc section with bad info.  This error will be
6013   // reported in the final link.
6014   unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6015   if (index >= this->shnum())
6016     return false;
6017
6018   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6019   const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6020   return this->section_is_scannable(text_shdr, index,
6021                                    out_sections[index], symtab);
6022 }
6023
6024 // Return the output address of either a plain input section or a relaxed
6025 // input section.  SHNDX is the section index.  We define and use this
6026 // instead of calling Output_section::output_address because that is slow
6027 // for large output.
6028
6029 template<bool big_endian>
6030 Arm_address
6031 Arm_relobj<big_endian>::simple_input_section_output_address(
6032     unsigned int shndx,
6033     Output_section* os)
6034 {
6035   if (this->is_output_section_offset_invalid(shndx))
6036     {
6037       const Output_relaxed_input_section* poris =
6038         os->find_relaxed_input_section(this, shndx);
6039       // We do not handle merged sections here.
6040       gold_assert(poris != NULL);
6041       return poris->address();
6042     }
6043   else
6044     return os->address() + this->get_output_section_offset(shndx);
6045 }
6046
6047 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6048 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6049
6050 template<bool big_endian>
6051 bool
6052 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6053     const elfcpp::Shdr<32, big_endian>& shdr,
6054     unsigned int shndx,
6055     Output_section* os,
6056     const Symbol_table* symtab)
6057 {
6058   if (!this->section_is_scannable(shdr, shndx, os, symtab))
6059     return false;
6060
6061   // If the section does not cross any 4K-boundaries, it does not need to
6062   // be scanned.
6063   Arm_address address = this->simple_input_section_output_address(shndx, os);
6064   if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6065     return false;
6066
6067   return true;
6068 }
6069
6070 // Scan a section for Cortex-A8 workaround.
6071
6072 template<bool big_endian>
6073 void
6074 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6075     const elfcpp::Shdr<32, big_endian>& shdr,
6076     unsigned int shndx,
6077     Output_section* os,
6078     Target_arm<big_endian>* arm_target)
6079 {
6080   // Look for the first mapping symbol in this section.  It should be
6081   // at (shndx, 0).
6082   Mapping_symbol_position section_start(shndx, 0);
6083   typename Mapping_symbols_info::const_iterator p =
6084     this->mapping_symbols_info_.lower_bound(section_start);
6085
6086   // There are no mapping symbols for this section.  Treat it as a data-only
6087   // section.  Issue a warning if section is marked as containing
6088   // instructions.
6089   if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6090     {
6091       if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6092         gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6093                        "erratum because it has no mapping symbols."),
6094                      shndx, this->name().c_str());
6095       return;
6096     }
6097
6098   Arm_address output_address =
6099     this->simple_input_section_output_address(shndx, os);
6100
6101   // Get the section contents.
6102   section_size_type input_view_size = 0;
6103   const unsigned char* input_view =
6104     this->section_contents(shndx, &input_view_size, false);
6105
6106   // We need to go through the mapping symbols to determine what to
6107   // scan.  There are two reasons.  First, we should look at THUMB code and
6108   // THUMB code only.  Second, we only want to look at the 4K-page boundary
6109   // to speed up the scanning.
6110   
6111   while (p != this->mapping_symbols_info_.end()
6112         && p->first.first == shndx)
6113     {
6114       typename Mapping_symbols_info::const_iterator next =
6115         this->mapping_symbols_info_.upper_bound(p->first);
6116
6117       // Only scan part of a section with THUMB code.
6118       if (p->second == 't')
6119         {
6120           // Determine the end of this range.
6121           section_size_type span_start =
6122             convert_to_section_size_type(p->first.second);
6123           section_size_type span_end;
6124           if (next != this->mapping_symbols_info_.end()
6125               && next->first.first == shndx)
6126             span_end = convert_to_section_size_type(next->first.second);
6127           else
6128             span_end = convert_to_section_size_type(shdr.get_sh_size());
6129           
6130           if (((span_start + output_address) & ~0xfffUL)
6131               != ((span_end + output_address - 1) & ~0xfffUL))
6132             {
6133               arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6134                                                           span_start, span_end,
6135                                                           input_view,
6136                                                           output_address);
6137             }
6138         }
6139
6140       p = next; 
6141     }
6142 }
6143
6144 // Scan relocations for stub generation.
6145
6146 template<bool big_endian>
6147 void
6148 Arm_relobj<big_endian>::scan_sections_for_stubs(
6149     Target_arm<big_endian>* arm_target,
6150     const Symbol_table* symtab,
6151     const Layout* layout)
6152 {
6153   unsigned int shnum = this->shnum();
6154   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6155
6156   // Read the section headers.
6157   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6158                                                shnum * shdr_size,
6159                                                true, true);
6160
6161   // To speed up processing, we set up hash tables for fast lookup of
6162   // input offsets to output addresses.
6163   this->initialize_input_to_output_maps();
6164
6165   const Relobj::Output_sections& out_sections(this->output_sections());
6166
6167   Relocate_info<32, big_endian> relinfo;
6168   relinfo.symtab = symtab;
6169   relinfo.layout = layout;
6170   relinfo.object = this;
6171
6172   // Do relocation stubs scanning.
6173   const unsigned char* p = pshdrs + shdr_size;
6174   for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6175     {
6176       const elfcpp::Shdr<32, big_endian> shdr(p);
6177       if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6178                                                   pshdrs))
6179         {
6180           unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6181           Arm_address output_offset = this->get_output_section_offset(index);
6182           Arm_address output_address;
6183           if (output_offset != invalid_address)
6184             output_address = out_sections[index]->address() + output_offset;
6185           else
6186             {
6187               // Currently this only happens for a relaxed section.
6188               const Output_relaxed_input_section* poris =
6189               out_sections[index]->find_relaxed_input_section(this, index);
6190               gold_assert(poris != NULL);
6191               output_address = poris->address();
6192             }
6193
6194           // Get the relocations.
6195           const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6196                                                         shdr.get_sh_size(),
6197                                                         true, false);
6198
6199           // Get the section contents.  This does work for the case in which
6200           // we modify the contents of an input section.  We need to pass the
6201           // output view under such circumstances.
6202           section_size_type input_view_size = 0;
6203           const unsigned char* input_view =
6204             this->section_contents(index, &input_view_size, false);
6205
6206           relinfo.reloc_shndx = i;
6207           relinfo.data_shndx = index;
6208           unsigned int sh_type = shdr.get_sh_type();
6209           unsigned int reloc_size;
6210           if (sh_type == elfcpp::SHT_REL)
6211             reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6212           else
6213             reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6214
6215           Output_section* os = out_sections[index];
6216           arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6217                                              shdr.get_sh_size() / reloc_size,
6218                                              os,
6219                                              output_offset == invalid_address,
6220                                              input_view, output_address,
6221                                              input_view_size);
6222         }
6223     }
6224
6225   // Do Cortex-A8 erratum stubs scanning.  This has to be done for a section
6226   // after its relocation section, if there is one, is processed for
6227   // relocation stubs.  Merging this loop with the one above would have been
6228   // complicated since we would have had to make sure that relocation stub
6229   // scanning is done first.
6230   if (arm_target->fix_cortex_a8())
6231     {
6232       const unsigned char* p = pshdrs + shdr_size;
6233       for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6234         {
6235           const elfcpp::Shdr<32, big_endian> shdr(p);
6236           if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6237                                                           out_sections[i],
6238                                                           symtab))
6239             this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6240                                                      arm_target);
6241         }
6242     }
6243
6244   // After we've done the relocations, we release the hash tables,
6245   // since we no longer need them.
6246   this->free_input_to_output_maps();
6247 }
6248
6249 // Count the local symbols.  The ARM backend needs to know if a symbol
6250 // is a THUMB function or not.  For global symbols, it is easy because
6251 // the Symbol object keeps the ELF symbol type.  For local symbol it is
6252 // harder because we cannot access this information.   So we override the
6253 // do_count_local_symbol in parent and scan local symbols to mark
6254 // THUMB functions.  This is not the most efficient way but I do not want to
6255 // slow down other ports by calling a per symbol targer hook inside
6256 // Sized_relobj<size, big_endian>::do_count_local_symbols. 
6257
6258 template<bool big_endian>
6259 void
6260 Arm_relobj<big_endian>::do_count_local_symbols(
6261     Stringpool_template<char>* pool,
6262     Stringpool_template<char>* dynpool)
6263 {
6264   // We need to fix-up the values of any local symbols whose type are
6265   // STT_ARM_TFUNC.
6266   
6267   // Ask parent to count the local symbols.
6268   Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
6269   const unsigned int loccount = this->local_symbol_count();
6270   if (loccount == 0)
6271     return;
6272
6273   // Intialize the thumb function bit-vector.
6274   std::vector<bool> empty_vector(loccount, false);
6275   this->local_symbol_is_thumb_function_.swap(empty_vector);
6276
6277   // Read the symbol table section header.
6278   const unsigned int symtab_shndx = this->symtab_shndx();
6279   elfcpp::Shdr<32, big_endian>
6280       symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6281   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6282
6283   // Read the local symbols.
6284   const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6285   gold_assert(loccount == symtabshdr.get_sh_info());
6286   off_t locsize = loccount * sym_size;
6287   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6288                                               locsize, true, true);
6289
6290   // For mapping symbol processing, we need to read the symbol names.
6291   unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6292   if (strtab_shndx >= this->shnum())
6293     {
6294       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6295       return;
6296     }
6297
6298   elfcpp::Shdr<32, big_endian>
6299     strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6300   if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6301     {
6302       this->error(_("symbol table name section has wrong type: %u"),
6303                   static_cast<unsigned int>(strtabshdr.get_sh_type()));
6304       return;
6305     }
6306   const char* pnames =
6307     reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6308                                                  strtabshdr.get_sh_size(),
6309                                                  false, false));
6310
6311   // Loop over the local symbols and mark any local symbols pointing
6312   // to THUMB functions.
6313
6314   // Skip the first dummy symbol.
6315   psyms += sym_size;
6316   typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
6317     this->local_values();
6318   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6319     {
6320       elfcpp::Sym<32, big_endian> sym(psyms);
6321       elfcpp::STT st_type = sym.get_st_type();
6322       Symbol_value<32>& lv((*plocal_values)[i]);
6323       Arm_address input_value = lv.input_value();
6324
6325       // Check to see if this is a mapping symbol.
6326       const char* sym_name = pnames + sym.get_st_name();
6327       if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6328         {
6329           bool is_ordinary;
6330           unsigned int input_shndx =
6331             this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6332           gold_assert(is_ordinary);
6333
6334           // Strip of LSB in case this is a THUMB symbol.
6335           Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6336           this->mapping_symbols_info_[msp] = sym_name[1];
6337         }
6338
6339       if (st_type == elfcpp::STT_ARM_TFUNC
6340           || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6341         {
6342           // This is a THUMB function.  Mark this and canonicalize the
6343           // symbol value by setting LSB.
6344           this->local_symbol_is_thumb_function_[i] = true;
6345           if ((input_value & 1) == 0)
6346             lv.set_input_value(input_value | 1);
6347         }
6348     }
6349 }
6350
6351 // Relocate sections.
6352 template<bool big_endian>
6353 void
6354 Arm_relobj<big_endian>::do_relocate_sections(
6355     const Symbol_table* symtab,
6356     const Layout* layout,
6357     const unsigned char* pshdrs,
6358     Output_file* of,
6359     typename Sized_relobj<32, big_endian>::Views* pviews)
6360 {
6361   // Call parent to relocate sections.
6362   Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
6363                                                      of, pviews); 
6364
6365   // We do not generate stubs if doing a relocatable link.
6366   if (parameters->options().relocatable())
6367     return;
6368
6369   // Relocate stub tables.
6370   unsigned int shnum = this->shnum();
6371
6372   Target_arm<big_endian>* arm_target =
6373     Target_arm<big_endian>::default_target();
6374
6375   Relocate_info<32, big_endian> relinfo;
6376   relinfo.symtab = symtab;
6377   relinfo.layout = layout;
6378   relinfo.object = this;
6379
6380   for (unsigned int i = 1; i < shnum; ++i)
6381     {
6382       Arm_input_section<big_endian>* arm_input_section =
6383         arm_target->find_arm_input_section(this, i);
6384
6385       if (arm_input_section != NULL
6386           && arm_input_section->is_stub_table_owner()
6387           && !arm_input_section->stub_table()->empty())
6388         {
6389           // We cannot discard a section if it owns a stub table.
6390           Output_section* os = this->output_section(i);
6391           gold_assert(os != NULL);
6392
6393           relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6394           relinfo.reloc_shdr = NULL;
6395           relinfo.data_shndx = i;
6396           relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6397
6398           gold_assert((*pviews)[i].view != NULL);
6399
6400           // We are passed the output section view.  Adjust it to cover the
6401           // stub table only.
6402           Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6403           gold_assert((stub_table->address() >= (*pviews)[i].address)
6404                       && ((stub_table->address() + stub_table->data_size())
6405                           <= (*pviews)[i].address + (*pviews)[i].view_size));
6406
6407           off_t offset = stub_table->address() - (*pviews)[i].address;
6408           unsigned char* view = (*pviews)[i].view + offset;
6409           Arm_address address = stub_table->address();
6410           section_size_type view_size = stub_table->data_size();
6411  
6412           stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6413                                      view_size);
6414         }
6415
6416       // Apply Cortex A8 workaround if applicable.
6417       if (this->section_has_cortex_a8_workaround(i))
6418         {
6419           unsigned char* view = (*pviews)[i].view;
6420           Arm_address view_address = (*pviews)[i].address;
6421           section_size_type view_size = (*pviews)[i].view_size;
6422           Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6423
6424           // Adjust view to cover section.
6425           Output_section* os = this->output_section(i);
6426           gold_assert(os != NULL);
6427           Arm_address section_address =
6428             this->simple_input_section_output_address(i, os);
6429           uint64_t section_size = this->section_size(i);
6430
6431           gold_assert(section_address >= view_address
6432                       && ((section_address + section_size)
6433                           <= (view_address + view_size)));
6434
6435           unsigned char* section_view = view + (section_address - view_address);
6436
6437           // Apply the Cortex-A8 workaround to the output address range
6438           // corresponding to this input section.
6439           stub_table->apply_cortex_a8_workaround_to_address_range(
6440               arm_target,
6441               section_view,
6442               section_address,
6443               section_size);
6444         }
6445     }
6446 }
6447
6448 // Find the linked text section of an EXIDX section by looking the the first
6449 // relocation.  4.4.1 of the EHABI specifications says that an EXIDX section
6450 // must be linked to to its associated code section via the sh_link field of
6451 // its section header.  However, some tools are broken and the link is not
6452 // always set.  LD just drops such an EXIDX section silently, causing the
6453 // associated code not unwindabled.   Here we try a little bit harder to
6454 // discover the linked code section.
6455 //
6456 // PSHDR points to the section header of a relocation section of an EXIDX
6457 // section.  If we can find a linked text section, return true and
6458 // store the text section index in the location PSHNDX.  Otherwise
6459 // return false.
6460
6461 template<bool big_endian>
6462 bool
6463 Arm_relobj<big_endian>::find_linked_text_section(
6464     const unsigned char* pshdr,
6465     const unsigned char* psyms,
6466     unsigned int* pshndx)
6467 {
6468   elfcpp::Shdr<32, big_endian> shdr(pshdr);
6469   
6470   // If there is no relocation, we cannot find the linked text section.
6471   size_t reloc_size;
6472   if (shdr.get_sh_type() == elfcpp::SHT_REL)
6473       reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6474   else
6475       reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6476   size_t reloc_count = shdr.get_sh_size() / reloc_size;
6477  
6478   // Get the relocations.
6479   const unsigned char* prelocs =
6480       this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false); 
6481
6482   // Find the REL31 relocation for the first word of the first EXIDX entry.
6483   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6484     {
6485       Arm_address r_offset;
6486       typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6487       if (shdr.get_sh_type() == elfcpp::SHT_REL)
6488         {
6489           typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6490           r_info = reloc.get_r_info();
6491           r_offset = reloc.get_r_offset();
6492         }
6493       else
6494         {
6495           typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6496           r_info = reloc.get_r_info();
6497           r_offset = reloc.get_r_offset();
6498         }
6499
6500       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6501       if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6502         continue;
6503
6504       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6505       if (r_sym == 0
6506           || r_sym >= this->local_symbol_count()
6507           || r_offset != 0)
6508         continue;
6509
6510       // This is the relocation for the first word of the first EXIDX entry.
6511       // We expect to see a local section symbol.
6512       const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6513       elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6514       if (sym.get_st_type() == elfcpp::STT_SECTION)
6515         {
6516           bool is_ordinary;
6517           *pshndx =
6518             this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6519           gold_assert(is_ordinary);
6520           return true;
6521         }
6522       else
6523         return false;
6524     }
6525
6526   return false;
6527 }
6528
6529 // Make an EXIDX input section object for an EXIDX section whose index is
6530 // SHNDX.  SHDR is the section header of the EXIDX section and TEXT_SHNDX
6531 // is the section index of the linked text section.
6532
6533 template<bool big_endian>
6534 void
6535 Arm_relobj<big_endian>::make_exidx_input_section(
6536     unsigned int shndx,
6537     const elfcpp::Shdr<32, big_endian>& shdr,
6538     unsigned int text_shndx,
6539     const elfcpp::Shdr<32, big_endian>& text_shdr)
6540 {
6541   // Create an Arm_exidx_input_section object for this EXIDX section.
6542   Arm_exidx_input_section* exidx_input_section =
6543     new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6544                                 shdr.get_sh_addralign());
6545
6546   gold_assert(this->exidx_section_map_[shndx] == NULL);
6547   this->exidx_section_map_[shndx] = exidx_input_section;
6548
6549   if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6550     {
6551       gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6552                  this->section_name(shndx).c_str(), shndx, text_shndx,
6553                  this->name().c_str());
6554       exidx_input_section->set_has_errors();
6555     } 
6556   else if (this->exidx_section_map_[text_shndx] != NULL)
6557     {
6558       unsigned other_exidx_shndx =
6559         this->exidx_section_map_[text_shndx]->shndx();
6560       gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6561                    "%s(%u) in %s"),
6562                  this->section_name(shndx).c_str(), shndx,
6563                  this->section_name(other_exidx_shndx).c_str(),
6564                  other_exidx_shndx, this->section_name(text_shndx).c_str(),
6565                  text_shndx, this->name().c_str());
6566       exidx_input_section->set_has_errors();
6567     }
6568   else
6569      this->exidx_section_map_[text_shndx] = exidx_input_section;
6570
6571   // Check section flags of text section.
6572   if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6573     {
6574       gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6575                    " in %s"),
6576                  this->section_name(shndx).c_str(), shndx,
6577                  this->section_name(text_shndx).c_str(), text_shndx,
6578                  this->name().c_str());
6579       exidx_input_section->set_has_errors();
6580     }
6581   else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6582     // I would like to make this an error but currenlty ld just ignores
6583     // this.
6584     gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6585                    "%s(%u) in %s"),
6586                  this->section_name(shndx).c_str(), shndx,
6587                  this->section_name(text_shndx).c_str(), text_shndx,
6588                  this->name().c_str());
6589 }
6590
6591 // Read the symbol information.
6592
6593 template<bool big_endian>
6594 void
6595 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6596 {
6597   // Call parent class to read symbol information.
6598   Sized_relobj<32, big_endian>::do_read_symbols(sd);
6599
6600   // If this input file is a binary file, it has no processor
6601   // specific flags and attributes section.
6602   Input_file::Format format = this->input_file()->format();
6603   if (format != Input_file::FORMAT_ELF)
6604     {
6605       gold_assert(format == Input_file::FORMAT_BINARY);
6606       this->merge_flags_and_attributes_ = false;
6607       return;
6608     }
6609
6610   // Read processor-specific flags in ELF file header.
6611   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6612                                               elfcpp::Elf_sizes<32>::ehdr_size,
6613                                               true, false);
6614   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6615   this->processor_specific_flags_ = ehdr.get_e_flags();
6616
6617   // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6618   // sections.
6619   std::vector<unsigned int> deferred_exidx_sections;
6620   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6621   const unsigned char* pshdrs = sd->section_headers->data();
6622   const unsigned char* ps = pshdrs + shdr_size;
6623   bool must_merge_flags_and_attributes = false;
6624   for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6625     {
6626       elfcpp::Shdr<32, big_endian> shdr(ps);
6627
6628       // Sometimes an object has no contents except the section name string
6629       // table and an empty symbol table with the undefined symbol.  We
6630       // don't want to merge processor-specific flags from such an object.
6631       if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6632         {
6633           // Symbol table is not empty.
6634           const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6635              elfcpp::Elf_sizes<32>::sym_size;
6636           if (shdr.get_sh_size() > sym_size)
6637             must_merge_flags_and_attributes = true;
6638         }
6639       else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6640         // If this is neither an empty symbol table nor a string table,
6641         // be conservative.
6642         must_merge_flags_and_attributes = true;
6643
6644       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6645         {
6646           gold_assert(this->attributes_section_data_ == NULL);
6647           section_offset_type section_offset = shdr.get_sh_offset();
6648           section_size_type section_size =
6649             convert_to_section_size_type(shdr.get_sh_size());
6650           File_view* view = this->get_lasting_view(section_offset,
6651                                                    section_size, true, false);
6652           this->attributes_section_data_ =
6653             new Attributes_section_data(view->data(), section_size);
6654         }
6655       else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6656         {
6657           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6658           if (text_shndx == elfcpp::SHN_UNDEF)
6659             deferred_exidx_sections.push_back(i);
6660           else
6661             {
6662               elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6663                                                      + text_shndx * shdr_size);
6664               this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6665             }
6666           // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6667           if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6668             gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6669                          this->section_name(i).c_str(), this->name().c_str());
6670         }
6671     }
6672
6673   // This is rare.
6674   if (!must_merge_flags_and_attributes)
6675     {
6676       gold_assert(deferred_exidx_sections.empty());
6677       this->merge_flags_and_attributes_ = false;
6678       return;
6679     }
6680
6681   // Some tools are broken and they do not set the link of EXIDX sections. 
6682   // We look at the first relocation to figure out the linked sections.
6683   if (!deferred_exidx_sections.empty())
6684     {
6685       // We need to go over the section headers again to find the mapping
6686       // from sections being relocated to their relocation sections.  This is
6687       // a bit inefficient as we could do that in the loop above.  However,
6688       // we do not expect any deferred EXIDX sections normally.  So we do not
6689       // want to slow down the most common path.
6690       typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6691       Reloc_map reloc_map;
6692       ps = pshdrs + shdr_size;
6693       for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6694         {
6695           elfcpp::Shdr<32, big_endian> shdr(ps);
6696           elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6697           if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6698             {
6699               unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6700               if (info_shndx >= this->shnum())
6701                 gold_error(_("relocation section %u has invalid info %u"),
6702                            i, info_shndx);
6703               Reloc_map::value_type value(info_shndx, i);
6704               std::pair<Reloc_map::iterator, bool> result =
6705                 reloc_map.insert(value);
6706               if (!result.second)
6707                 gold_error(_("section %u has multiple relocation sections "
6708                              "%u and %u"),
6709                            info_shndx, i, reloc_map[info_shndx]);
6710             }
6711         }
6712
6713       // Read the symbol table section header.
6714       const unsigned int symtab_shndx = this->symtab_shndx();
6715       elfcpp::Shdr<32, big_endian>
6716           symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6717       gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6718
6719       // Read the local symbols.
6720       const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6721       const unsigned int loccount = this->local_symbol_count();
6722       gold_assert(loccount == symtabshdr.get_sh_info());
6723       off_t locsize = loccount * sym_size;
6724       const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6725                                                   locsize, true, true);
6726
6727       // Process the deferred EXIDX sections. 
6728       for(unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6729         {
6730           unsigned int shndx = deferred_exidx_sections[i];
6731           elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6732           unsigned int text_shndx = elfcpp::SHN_UNDEF;
6733           Reloc_map::const_iterator it = reloc_map.find(shndx);
6734           if (it != reloc_map.end())
6735             find_linked_text_section(pshdrs + it->second * shdr_size,
6736                                      psyms, &text_shndx);
6737           elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6738                                                  + text_shndx * shdr_size);
6739           this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6740         }
6741     }
6742 }
6743
6744 // Process relocations for garbage collection.  The ARM target uses .ARM.exidx
6745 // sections for unwinding.  These sections are referenced implicitly by 
6746 // text sections linked in the section headers.  If we ignore these implict
6747 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6748 // will be garbage-collected incorrectly.  Hence we override the same function
6749 // in the base class to handle these implicit references.
6750
6751 template<bool big_endian>
6752 void
6753 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6754                                              Layout* layout,
6755                                              Read_relocs_data* rd)
6756 {
6757   // First, call base class method to process relocations in this object.
6758   Sized_relobj<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6759
6760   // If --gc-sections is not specified, there is nothing more to do.
6761   // This happens when --icf is used but --gc-sections is not.
6762   if (!parameters->options().gc_sections())
6763     return;
6764   
6765   unsigned int shnum = this->shnum();
6766   const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6767   const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6768                                                shnum * shdr_size,
6769                                                true, true);
6770
6771   // Scan section headers for sections of type SHT_ARM_EXIDX.  Add references
6772   // to these from the linked text sections.
6773   const unsigned char* ps = pshdrs + shdr_size;
6774   for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6775     {
6776       elfcpp::Shdr<32, big_endian> shdr(ps);
6777       if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6778         {
6779           // Found an .ARM.exidx section, add it to the set of reachable
6780           // sections from its linked text section.
6781           unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6782           symtab->gc()->add_reference(this, text_shndx, this, i);
6783         }
6784     }
6785 }
6786
6787 // Update output local symbol count.  Owing to EXIDX entry merging, some local
6788 // symbols  will be removed in output.  Adjust output local symbol count
6789 // accordingly.  We can only changed the static output local symbol count.  It
6790 // is too late to change the dynamic symbols.
6791
6792 template<bool big_endian>
6793 void
6794 Arm_relobj<big_endian>::update_output_local_symbol_count()
6795 {
6796   // Caller should check that this needs updating.  We want caller checking
6797   // because output_local_symbol_count_needs_update() is most likely inlined.
6798   gold_assert(this->output_local_symbol_count_needs_update_);
6799
6800   gold_assert(this->symtab_shndx() != -1U);
6801   if (this->symtab_shndx() == 0)
6802     {
6803       // This object has no symbols.  Weird but legal.
6804       return;
6805     }
6806
6807   // Read the symbol table section header.
6808   const unsigned int symtab_shndx = this->symtab_shndx();
6809   elfcpp::Shdr<32, big_endian>
6810     symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6811   gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6812
6813   // Read the local symbols.
6814   const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6815   const unsigned int loccount = this->local_symbol_count();
6816   gold_assert(loccount == symtabshdr.get_sh_info());
6817   off_t locsize = loccount * sym_size;
6818   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6819                                               locsize, true, true);
6820
6821   // Loop over the local symbols.
6822
6823   typedef typename Sized_relobj<32, big_endian>::Output_sections
6824      Output_sections;
6825   const Output_sections& out_sections(this->output_sections());
6826   unsigned int shnum = this->shnum();
6827   unsigned int count = 0;
6828   // Skip the first, dummy, symbol.
6829   psyms += sym_size;
6830   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6831     {
6832       elfcpp::Sym<32, big_endian> sym(psyms);
6833
6834       Symbol_value<32>& lv((*this->local_values())[i]);
6835
6836       // This local symbol was already discarded by do_count_local_symbols.
6837       if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6838         continue;
6839
6840       bool is_ordinary;
6841       unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6842                                                   &is_ordinary);
6843
6844       if (shndx < shnum)
6845         {
6846           Output_section* os = out_sections[shndx];
6847
6848           // This local symbol no longer has an output section.  Discard it.
6849           if (os == NULL)
6850             {
6851               lv.set_no_output_symtab_entry();
6852               continue;
6853             }
6854
6855           // Currently we only discard parts of EXIDX input sections.
6856           // We explicitly check for a merged EXIDX input section to avoid
6857           // calling Output_section_data::output_offset unless necessary.
6858           if ((this->get_output_section_offset(shndx) == invalid_address)
6859               && (this->exidx_input_section_by_shndx(shndx) != NULL))
6860             {
6861               section_offset_type output_offset =
6862                 os->output_offset(this, shndx, lv.input_value());
6863               if (output_offset == -1)
6864                 {
6865                   // This symbol is defined in a part of an EXIDX input section
6866                   // that is discarded due to entry merging.
6867                   lv.set_no_output_symtab_entry();
6868                   continue;
6869                 }       
6870             }
6871         }
6872
6873       ++count;
6874     }
6875
6876   this->set_output_local_symbol_count(count);
6877   this->output_local_symbol_count_needs_update_ = false;
6878 }
6879
6880 // Arm_dynobj methods.
6881
6882 // Read the symbol information.
6883
6884 template<bool big_endian>
6885 void
6886 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6887 {
6888   // Call parent class to read symbol information.
6889   Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6890
6891   // Read processor-specific flags in ELF file header.
6892   const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6893                                               elfcpp::Elf_sizes<32>::ehdr_size,
6894                                               true, false);
6895   elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6896   this->processor_specific_flags_ = ehdr.get_e_flags();
6897
6898   // Read the attributes section if there is one.
6899   // We read from the end because gas seems to put it near the end of
6900   // the section headers.
6901   const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6902   const unsigned char* ps =
6903     sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6904   for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6905     {
6906       elfcpp::Shdr<32, big_endian> shdr(ps);
6907       if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6908         {
6909           section_offset_type section_offset = shdr.get_sh_offset();
6910           section_size_type section_size =
6911             convert_to_section_size_type(shdr.get_sh_size());
6912           File_view* view = this->get_lasting_view(section_offset,
6913                                                    section_size, true, false);
6914           this->attributes_section_data_ =
6915             new Attributes_section_data(view->data(), section_size);
6916           break;
6917         }
6918     }
6919 }
6920
6921 // Stub_addend_reader methods.
6922
6923 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6924
6925 template<bool big_endian>
6926 elfcpp::Elf_types<32>::Elf_Swxword
6927 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6928     unsigned int r_type,
6929     const unsigned char* view,
6930     const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6931 {
6932   typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6933   
6934   switch (r_type)
6935     {
6936     case elfcpp::R_ARM_CALL:
6937     case elfcpp::R_ARM_JUMP24:
6938     case elfcpp::R_ARM_PLT32:
6939       {
6940         typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6941         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6942         Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6943         return utils::sign_extend<26>(val << 2);
6944       }
6945
6946     case elfcpp::R_ARM_THM_CALL:
6947     case elfcpp::R_ARM_THM_JUMP24:
6948     case elfcpp::R_ARM_THM_XPC22:
6949       {
6950         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6951         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6952         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6953         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6954         return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
6955       }
6956
6957     case elfcpp::R_ARM_THM_JUMP19:
6958       {
6959         typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6960         const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6961         Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6962         Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6963         return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
6964       }
6965
6966     default:
6967       gold_unreachable();
6968     }
6969 }
6970
6971 // Arm_output_data_got methods.
6972
6973 // Add a GOT pair for R_ARM_TLS_GD32.  The creates a pair of GOT entries.
6974 // The first one is initialized to be 1, which is the module index for
6975 // the main executable and the second one 0.  A reloc of the type
6976 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
6977 // be applied by gold.  GSYM is a global symbol.
6978 //
6979 template<bool big_endian>
6980 void
6981 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6982     unsigned int got_type,
6983     Symbol* gsym)
6984 {
6985   if (gsym->has_got_offset(got_type))
6986     return;
6987
6988   // We are doing a static link.  Just mark it as belong to module 1,
6989   // the executable.
6990   unsigned int got_offset = this->add_constant(1);
6991   gsym->set_got_offset(got_type, got_offset); 
6992   got_offset = this->add_constant(0);
6993   this->static_relocs_.push_back(Static_reloc(got_offset,
6994                                               elfcpp::R_ARM_TLS_DTPOFF32,
6995                                               gsym));
6996 }
6997
6998 // Same as the above but for a local symbol.
6999
7000 template<bool big_endian>
7001 void
7002 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7003   unsigned int got_type,
7004   Sized_relobj<32, big_endian>* object,
7005   unsigned int index)
7006 {
7007   if (object->local_has_got_offset(index, got_type))
7008     return;
7009
7010   // We are doing a static link.  Just mark it as belong to module 1,
7011   // the executable.
7012   unsigned int got_offset = this->add_constant(1);
7013   object->set_local_got_offset(index, got_type, got_offset);
7014   got_offset = this->add_constant(0);
7015   this->static_relocs_.push_back(Static_reloc(got_offset, 
7016                                               elfcpp::R_ARM_TLS_DTPOFF32, 
7017                                               object, index));
7018 }
7019
7020 template<bool big_endian>
7021 void
7022 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7023 {
7024   // Call parent to write out GOT.
7025   Output_data_got<32, big_endian>::do_write(of);
7026
7027   // We are done if there is no fix up.
7028   if (this->static_relocs_.empty())
7029     return;
7030
7031   gold_assert(parameters->doing_static_link());
7032
7033   const off_t offset = this->offset();
7034   const section_size_type oview_size =
7035     convert_to_section_size_type(this->data_size());
7036   unsigned char* const oview = of->get_output_view(offset, oview_size);
7037
7038   Output_segment* tls_segment = this->layout_->tls_segment();
7039   gold_assert(tls_segment != NULL);
7040   
7041   // The thread pointer $tp points to the TCB, which is followed by the
7042   // TLS.  So we need to adjust $tp relative addressing by this amount.
7043   Arm_address aligned_tcb_size =
7044     align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7045
7046   for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7047     {
7048       Static_reloc& reloc(this->static_relocs_[i]);
7049       
7050       Arm_address value;
7051       if (!reloc.symbol_is_global())
7052         {
7053           Sized_relobj<32, big_endian>* object = reloc.relobj();
7054           const Symbol_value<32>* psymval =
7055             reloc.relobj()->local_symbol(reloc.index());
7056
7057           // We are doing static linking.  Issue an error and skip this
7058           // relocation if the symbol is undefined or in a discarded_section.
7059           bool is_ordinary;
7060           unsigned int shndx = psymval->input_shndx(&is_ordinary);
7061           if ((shndx == elfcpp::SHN_UNDEF)
7062               || (is_ordinary
7063                   && shndx != elfcpp::SHN_UNDEF
7064                   && !object->is_section_included(shndx)
7065                   && !this->symbol_table_->is_section_folded(object, shndx)))
7066             {
7067               gold_error(_("undefined or discarded local symbol %u from "
7068                            " object %s in GOT"),
7069                          reloc.index(), reloc.relobj()->name().c_str());
7070               continue;
7071             }
7072           
7073           value = psymval->value(object, 0);
7074         }
7075       else
7076         {
7077           const Symbol* gsym = reloc.symbol();
7078           gold_assert(gsym != NULL);
7079           if (gsym->is_forwarder())
7080             gsym = this->symbol_table_->resolve_forwards(gsym);
7081
7082           // We are doing static linking.  Issue an error and skip this
7083           // relocation if the symbol is undefined or in a discarded_section
7084           // unless it is a weakly_undefined symbol.
7085           if ((gsym->is_defined_in_discarded_section()
7086                || gsym->is_undefined())
7087               && !gsym->is_weak_undefined())
7088             {
7089               gold_error(_("undefined or discarded symbol %s in GOT"),
7090                          gsym->name());
7091               continue;
7092             }
7093
7094           if (!gsym->is_weak_undefined())
7095             {
7096               const Sized_symbol<32>* sym =
7097                 static_cast<const Sized_symbol<32>*>(gsym);
7098               value = sym->value();
7099             }
7100           else
7101               value = 0;
7102         }
7103
7104       unsigned got_offset = reloc.got_offset();
7105       gold_assert(got_offset < oview_size);
7106
7107       typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7108       Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7109       Valtype x;
7110       switch (reloc.r_type())
7111         {
7112         case elfcpp::R_ARM_TLS_DTPOFF32:
7113           x = value;
7114           break;
7115         case elfcpp::R_ARM_TLS_TPOFF32:
7116           x = value + aligned_tcb_size;
7117           break;
7118         default:
7119           gold_unreachable();
7120         }
7121       elfcpp::Swap<32, big_endian>::writeval(wv, x);
7122     }
7123
7124   of->write_output_view(offset, oview_size, oview);
7125 }
7126
7127 // A class to handle the PLT data.
7128
7129 template<bool big_endian>
7130 class Output_data_plt_arm : public Output_section_data
7131 {
7132  public:
7133   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7134     Reloc_section;
7135
7136   Output_data_plt_arm(Layout*, Output_data_space*);
7137
7138   // Add an entry to the PLT.
7139   void
7140   add_entry(Symbol* gsym);
7141
7142   // Return the .rel.plt section data.
7143   const Reloc_section*
7144   rel_plt() const
7145   { return this->rel_; }
7146
7147   // Return the number of PLT entries.
7148   unsigned int
7149   entry_count() const
7150   { return this->count_; }
7151
7152   // Return the offset of the first non-reserved PLT entry.
7153   static unsigned int
7154   first_plt_entry_offset()
7155   { return sizeof(first_plt_entry); }
7156
7157   // Return the size of a PLT entry.
7158   static unsigned int
7159   get_plt_entry_size()
7160   { return sizeof(plt_entry); }
7161
7162  protected:
7163   void
7164   do_adjust_output_section(Output_section* os);
7165
7166   // Write to a map file.
7167   void
7168   do_print_to_mapfile(Mapfile* mapfile) const
7169   { mapfile->print_output_data(this, _("** PLT")); }
7170
7171  private:
7172   // Template for the first PLT entry.
7173   static const uint32_t first_plt_entry[5];
7174
7175   // Template for subsequent PLT entries. 
7176   static const uint32_t plt_entry[3];
7177
7178   // Set the final size.
7179   void
7180   set_final_data_size()
7181   {
7182     this->set_data_size(sizeof(first_plt_entry)
7183                         + this->count_ * sizeof(plt_entry));
7184   }
7185
7186   // Write out the PLT data.
7187   void
7188   do_write(Output_file*);
7189
7190   // The reloc section.
7191   Reloc_section* rel_;
7192   // The .got.plt section.
7193   Output_data_space* got_plt_;
7194   // The number of PLT entries.
7195   unsigned int count_;
7196 };
7197
7198 // Create the PLT section.  The ordinary .got section is an argument,
7199 // since we need to refer to the start.  We also create our own .got
7200 // section just for PLT entries.
7201
7202 template<bool big_endian>
7203 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7204                                                      Output_data_space* got_plt)
7205   : Output_section_data(4), got_plt_(got_plt), count_(0)
7206 {
7207   this->rel_ = new Reloc_section(false);
7208   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7209                                   elfcpp::SHF_ALLOC, this->rel_,
7210                                   ORDER_DYNAMIC_PLT_RELOCS, false);
7211 }
7212
7213 template<bool big_endian>
7214 void
7215 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7216 {
7217   os->set_entsize(0);
7218 }
7219
7220 // Add an entry to the PLT.
7221
7222 template<bool big_endian>
7223 void
7224 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7225 {
7226   gold_assert(!gsym->has_plt_offset());
7227
7228   // Note that when setting the PLT offset we skip the initial
7229   // reserved PLT entry.
7230   gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
7231                        + sizeof(first_plt_entry));
7232
7233   ++this->count_;
7234
7235   section_offset_type got_offset = this->got_plt_->current_data_size();
7236
7237   // Every PLT entry needs a GOT entry which points back to the PLT
7238   // entry (this will be changed by the dynamic linker, normally
7239   // lazily when the function is called).
7240   this->got_plt_->set_current_data_size(got_offset + 4);
7241
7242   // Every PLT entry needs a reloc.
7243   gsym->set_needs_dynsym_entry();
7244   this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7245                          got_offset);
7246
7247   // Note that we don't need to save the symbol.  The contents of the
7248   // PLT are independent of which symbols are used.  The symbols only
7249   // appear in the relocations.
7250 }
7251
7252 // ARM PLTs.
7253 // FIXME:  This is not very flexible.  Right now this has only been tested
7254 // on armv5te.  If we are to support additional architecture features like
7255 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7256
7257 // The first entry in the PLT.
7258 template<bool big_endian>
7259 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
7260 {
7261   0xe52de004,   // str   lr, [sp, #-4]!
7262   0xe59fe004,   // ldr   lr, [pc, #4]
7263   0xe08fe00e,   // add   lr, pc, lr 
7264   0xe5bef008,   // ldr   pc, [lr, #8]!
7265   0x00000000,   // &GOT[0] - .
7266 };
7267
7268 // Subsequent entries in the PLT.
7269
7270 template<bool big_endian>
7271 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7272 {
7273   0xe28fc600,   // add   ip, pc, #0xNN00000
7274   0xe28cca00,   // add   ip, ip, #0xNN000
7275   0xe5bcf000,   // ldr   pc, [ip, #0xNNN]!
7276 };
7277
7278 // Write out the PLT.  This uses the hand-coded instructions above,
7279 // and adjusts them as needed.  This is all specified by the arm ELF
7280 // Processor Supplement.
7281
7282 template<bool big_endian>
7283 void
7284 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7285 {
7286   const off_t offset = this->offset();
7287   const section_size_type oview_size =
7288     convert_to_section_size_type(this->data_size());
7289   unsigned char* const oview = of->get_output_view(offset, oview_size);
7290
7291   const off_t got_file_offset = this->got_plt_->offset();
7292   const section_size_type got_size =
7293     convert_to_section_size_type(this->got_plt_->data_size());
7294   unsigned char* const got_view = of->get_output_view(got_file_offset,
7295                                                       got_size);
7296   unsigned char* pov = oview;
7297
7298   Arm_address plt_address = this->address();
7299   Arm_address got_address = this->got_plt_->address();
7300
7301   // Write first PLT entry.  All but the last word are constants.
7302   const size_t num_first_plt_words = (sizeof(first_plt_entry)
7303                                       / sizeof(plt_entry[0]));
7304   for (size_t i = 0; i < num_first_plt_words - 1; i++)
7305     elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7306   // Last word in first PLT entry is &GOT[0] - .
7307   elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7308                                          got_address - (plt_address + 16));
7309   pov += sizeof(first_plt_entry);
7310
7311   unsigned char* got_pov = got_view;
7312
7313   memset(got_pov, 0, 12);
7314   got_pov += 12;
7315
7316   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7317   unsigned int plt_offset = sizeof(first_plt_entry);
7318   unsigned int plt_rel_offset = 0;
7319   unsigned int got_offset = 12;
7320   const unsigned int count = this->count_;
7321   for (unsigned int i = 0;
7322        i < count;
7323        ++i,
7324          pov += sizeof(plt_entry),
7325          got_pov += 4,
7326          plt_offset += sizeof(plt_entry),
7327          plt_rel_offset += rel_size,
7328          got_offset += 4)
7329     {
7330       // Set and adjust the PLT entry itself.
7331       int32_t offset = ((got_address + got_offset)
7332                          - (plt_address + plt_offset + 8));
7333
7334       gold_assert(offset >= 0 && offset < 0x0fffffff);
7335       uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7336       elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7337       uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7338       elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7339       uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7340       elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7341
7342       // Set the entry in the GOT.
7343       elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7344     }
7345
7346   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7347   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7348
7349   of->write_output_view(offset, oview_size, oview);
7350   of->write_output_view(got_file_offset, got_size, got_view);
7351 }
7352
7353 // Create a PLT entry for a global symbol.
7354
7355 template<bool big_endian>
7356 void
7357 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7358                                        Symbol* gsym)
7359 {
7360   if (gsym->has_plt_offset())
7361     return;
7362
7363   if (this->plt_ == NULL)
7364     {
7365       // Create the GOT sections first.
7366       this->got_section(symtab, layout);
7367
7368       this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7369       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7370                                       (elfcpp::SHF_ALLOC
7371                                        | elfcpp::SHF_EXECINSTR),
7372                                       this->plt_, ORDER_PLT, false);
7373     }
7374   this->plt_->add_entry(gsym);
7375 }
7376
7377 // Return the number of entries in the PLT.
7378
7379 template<bool big_endian>
7380 unsigned int
7381 Target_arm<big_endian>::plt_entry_count() const
7382 {
7383   if (this->plt_ == NULL)
7384     return 0;
7385   return this->plt_->entry_count();
7386 }
7387
7388 // Return the offset of the first non-reserved PLT entry.
7389
7390 template<bool big_endian>
7391 unsigned int
7392 Target_arm<big_endian>::first_plt_entry_offset() const
7393 {
7394   return Output_data_plt_arm<big_endian>::first_plt_entry_offset();
7395 }
7396
7397 // Return the size of each PLT entry.
7398
7399 template<bool big_endian>
7400 unsigned int
7401 Target_arm<big_endian>::plt_entry_size() const
7402 {
7403   return Output_data_plt_arm<big_endian>::get_plt_entry_size();
7404 }
7405
7406 // Get the section to use for TLS_DESC relocations.
7407
7408 template<bool big_endian>
7409 typename Target_arm<big_endian>::Reloc_section*
7410 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7411 {
7412   return this->plt_section()->rel_tls_desc(layout);
7413 }
7414
7415 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7416
7417 template<bool big_endian>
7418 void
7419 Target_arm<big_endian>::define_tls_base_symbol(
7420     Symbol_table* symtab,
7421     Layout* layout)
7422 {
7423   if (this->tls_base_symbol_defined_)
7424     return;
7425
7426   Output_segment* tls_segment = layout->tls_segment();
7427   if (tls_segment != NULL)
7428     {
7429       bool is_exec = parameters->options().output_is_executable();
7430       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7431                                        Symbol_table::PREDEFINED,
7432                                        tls_segment, 0, 0,
7433                                        elfcpp::STT_TLS,
7434                                        elfcpp::STB_LOCAL,
7435                                        elfcpp::STV_HIDDEN, 0,
7436                                        (is_exec
7437                                         ? Symbol::SEGMENT_END
7438                                         : Symbol::SEGMENT_START),
7439                                        true);
7440     }
7441   this->tls_base_symbol_defined_ = true;
7442 }
7443
7444 // Create a GOT entry for the TLS module index.
7445
7446 template<bool big_endian>
7447 unsigned int
7448 Target_arm<big_endian>::got_mod_index_entry(
7449     Symbol_table* symtab,
7450     Layout* layout,
7451     Sized_relobj<32, big_endian>* object)
7452 {
7453   if (this->got_mod_index_offset_ == -1U)
7454     {
7455       gold_assert(symtab != NULL && layout != NULL && object != NULL);
7456       Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7457       unsigned int got_offset;
7458       if (!parameters->doing_static_link())
7459         {
7460           got_offset = got->add_constant(0);
7461           Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7462           rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7463                              got_offset);
7464         }
7465       else
7466         {
7467           // We are doing a static link.  Just mark it as belong to module 1,
7468           // the executable.
7469           got_offset = got->add_constant(1);
7470         }
7471
7472       got->add_constant(0);
7473       this->got_mod_index_offset_ = got_offset;
7474     }
7475   return this->got_mod_index_offset_;
7476 }
7477
7478 // Optimize the TLS relocation type based on what we know about the
7479 // symbol.  IS_FINAL is true if the final address of this symbol is
7480 // known at link time.
7481
7482 template<bool big_endian>
7483 tls::Tls_optimization
7484 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7485 {
7486   // FIXME: Currently we do not do any TLS optimization.
7487   return tls::TLSOPT_NONE;
7488 }
7489
7490 // Report an unsupported relocation against a local symbol.
7491
7492 template<bool big_endian>
7493 void
7494 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7495     Sized_relobj<32, big_endian>* object,
7496     unsigned int r_type)
7497 {
7498   gold_error(_("%s: unsupported reloc %u against local symbol"),
7499              object->name().c_str(), r_type);
7500 }
7501
7502 // We are about to emit a dynamic relocation of type R_TYPE.  If the
7503 // dynamic linker does not support it, issue an error.  The GNU linker
7504 // only issues a non-PIC error for an allocated read-only section.
7505 // Here we know the section is allocated, but we don't know that it is
7506 // read-only.  But we check for all the relocation types which the
7507 // glibc dynamic linker supports, so it seems appropriate to issue an
7508 // error even if the section is not read-only.
7509
7510 template<bool big_endian>
7511 void
7512 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7513                                             unsigned int r_type)
7514 {
7515   switch (r_type)
7516     {
7517     // These are the relocation types supported by glibc for ARM.
7518     case elfcpp::R_ARM_RELATIVE:
7519     case elfcpp::R_ARM_COPY:
7520     case elfcpp::R_ARM_GLOB_DAT:
7521     case elfcpp::R_ARM_JUMP_SLOT:
7522     case elfcpp::R_ARM_ABS32:
7523     case elfcpp::R_ARM_ABS32_NOI:
7524     case elfcpp::R_ARM_PC24:
7525     // FIXME: The following 3 types are not supported by Android's dynamic
7526     // linker.
7527     case elfcpp::R_ARM_TLS_DTPMOD32:
7528     case elfcpp::R_ARM_TLS_DTPOFF32:
7529     case elfcpp::R_ARM_TLS_TPOFF32:
7530       return;
7531
7532     default:
7533       {
7534         // This prevents us from issuing more than one error per reloc
7535         // section.  But we can still wind up issuing more than one
7536         // error per object file.
7537         if (this->issued_non_pic_error_)
7538           return;
7539         const Arm_reloc_property* reloc_property =
7540           arm_reloc_property_table->get_reloc_property(r_type);
7541         gold_assert(reloc_property != NULL);
7542         object->error(_("requires unsupported dynamic reloc %s; "
7543                       "recompile with -fPIC"),
7544                       reloc_property->name().c_str());
7545         this->issued_non_pic_error_ = true;
7546         return;
7547       }
7548
7549     case elfcpp::R_ARM_NONE:
7550       gold_unreachable();
7551     }
7552 }
7553
7554 // Scan a relocation for a local symbol.
7555 // FIXME: This only handles a subset of relocation types used by Android
7556 // on ARM v5te devices.
7557
7558 template<bool big_endian>
7559 inline void
7560 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7561                                     Layout* layout,
7562                                     Target_arm* target,
7563                                     Sized_relobj<32, big_endian>* object,
7564                                     unsigned int data_shndx,
7565                                     Output_section* output_section,
7566                                     const elfcpp::Rel<32, big_endian>& reloc,
7567                                     unsigned int r_type,
7568                                     const elfcpp::Sym<32, big_endian>& lsym)
7569 {
7570   r_type = get_real_reloc_type(r_type);
7571   switch (r_type)
7572     {
7573     case elfcpp::R_ARM_NONE:
7574     case elfcpp::R_ARM_V4BX:
7575     case elfcpp::R_ARM_GNU_VTENTRY:
7576     case elfcpp::R_ARM_GNU_VTINHERIT:
7577       break;
7578
7579     case elfcpp::R_ARM_ABS32:
7580     case elfcpp::R_ARM_ABS32_NOI:
7581       // If building a shared library (or a position-independent
7582       // executable), we need to create a dynamic relocation for
7583       // this location. The relocation applied at link time will
7584       // apply the link-time value, so we flag the location with
7585       // an R_ARM_RELATIVE relocation so the dynamic loader can
7586       // relocate it easily.
7587       if (parameters->options().output_is_position_independent())
7588         {
7589           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7590           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7591           // If we are to add more other reloc types than R_ARM_ABS32,
7592           // we need to add check_non_pic(object, r_type) here.
7593           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7594                                       output_section, data_shndx,
7595                                       reloc.get_r_offset());
7596         }
7597       break;
7598
7599     case elfcpp::R_ARM_ABS16:
7600     case elfcpp::R_ARM_ABS12:
7601     case elfcpp::R_ARM_THM_ABS5:
7602     case elfcpp::R_ARM_ABS8:
7603     case elfcpp::R_ARM_BASE_ABS:
7604     case elfcpp::R_ARM_MOVW_ABS_NC:
7605     case elfcpp::R_ARM_MOVT_ABS:
7606     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7607     case elfcpp::R_ARM_THM_MOVT_ABS:
7608       // If building a shared library (or a position-independent
7609       // executable), we need to create a dynamic relocation for
7610       // this location. Because the addend needs to remain in the
7611       // data section, we need to be careful not to apply this
7612       // relocation statically.
7613       if (parameters->options().output_is_position_independent())
7614         {
7615           check_non_pic(object, r_type);
7616           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7617           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7618           if (lsym.get_st_type() != elfcpp::STT_SECTION)
7619             rel_dyn->add_local(object, r_sym, r_type, output_section,
7620                                data_shndx, reloc.get_r_offset());
7621           else
7622             {
7623               gold_assert(lsym.get_st_value() == 0);
7624               unsigned int shndx = lsym.get_st_shndx();
7625               bool is_ordinary;
7626               shndx = object->adjust_sym_shndx(r_sym, shndx,
7627                                                &is_ordinary);
7628               if (!is_ordinary)
7629                 object->error(_("section symbol %u has bad shndx %u"),
7630                               r_sym, shndx);
7631               else
7632                 rel_dyn->add_local_section(object, shndx,
7633                                            r_type, output_section,
7634                                            data_shndx, reloc.get_r_offset());
7635             }
7636         }
7637       break;
7638
7639     case elfcpp::R_ARM_REL32:
7640     case elfcpp::R_ARM_LDR_PC_G0:
7641     case elfcpp::R_ARM_SBREL32:
7642     case elfcpp::R_ARM_THM_CALL:
7643     case elfcpp::R_ARM_THM_PC8:
7644     case elfcpp::R_ARM_BASE_PREL:
7645     case elfcpp::R_ARM_PLT32:
7646     case elfcpp::R_ARM_CALL:
7647     case elfcpp::R_ARM_JUMP24:
7648     case elfcpp::R_ARM_THM_JUMP24:
7649     case elfcpp::R_ARM_SBREL31:
7650     case elfcpp::R_ARM_PREL31:
7651     case elfcpp::R_ARM_MOVW_PREL_NC:
7652     case elfcpp::R_ARM_MOVT_PREL:
7653     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7654     case elfcpp::R_ARM_THM_MOVT_PREL:
7655     case elfcpp::R_ARM_THM_JUMP19:
7656     case elfcpp::R_ARM_THM_JUMP6:
7657     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7658     case elfcpp::R_ARM_THM_PC12:
7659     case elfcpp::R_ARM_REL32_NOI:
7660     case elfcpp::R_ARM_ALU_PC_G0_NC:
7661     case elfcpp::R_ARM_ALU_PC_G0:
7662     case elfcpp::R_ARM_ALU_PC_G1_NC:
7663     case elfcpp::R_ARM_ALU_PC_G1:
7664     case elfcpp::R_ARM_ALU_PC_G2:
7665     case elfcpp::R_ARM_LDR_PC_G1:
7666     case elfcpp::R_ARM_LDR_PC_G2:
7667     case elfcpp::R_ARM_LDRS_PC_G0:
7668     case elfcpp::R_ARM_LDRS_PC_G1:
7669     case elfcpp::R_ARM_LDRS_PC_G2:
7670     case elfcpp::R_ARM_LDC_PC_G0:
7671     case elfcpp::R_ARM_LDC_PC_G1:
7672     case elfcpp::R_ARM_LDC_PC_G2:
7673     case elfcpp::R_ARM_ALU_SB_G0_NC:
7674     case elfcpp::R_ARM_ALU_SB_G0:
7675     case elfcpp::R_ARM_ALU_SB_G1_NC:
7676     case elfcpp::R_ARM_ALU_SB_G1:
7677     case elfcpp::R_ARM_ALU_SB_G2:
7678     case elfcpp::R_ARM_LDR_SB_G0:
7679     case elfcpp::R_ARM_LDR_SB_G1:
7680     case elfcpp::R_ARM_LDR_SB_G2:
7681     case elfcpp::R_ARM_LDRS_SB_G0:
7682     case elfcpp::R_ARM_LDRS_SB_G1:
7683     case elfcpp::R_ARM_LDRS_SB_G2:
7684     case elfcpp::R_ARM_LDC_SB_G0:
7685     case elfcpp::R_ARM_LDC_SB_G1:
7686     case elfcpp::R_ARM_LDC_SB_G2:
7687     case elfcpp::R_ARM_MOVW_BREL_NC:
7688     case elfcpp::R_ARM_MOVT_BREL:
7689     case elfcpp::R_ARM_MOVW_BREL:
7690     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7691     case elfcpp::R_ARM_THM_MOVT_BREL:
7692     case elfcpp::R_ARM_THM_MOVW_BREL:
7693     case elfcpp::R_ARM_THM_JUMP11:
7694     case elfcpp::R_ARM_THM_JUMP8:
7695       // We don't need to do anything for a relative addressing relocation
7696       // against a local symbol if it does not reference the GOT.
7697       break;
7698
7699     case elfcpp::R_ARM_GOTOFF32:
7700     case elfcpp::R_ARM_GOTOFF12:
7701       // We need a GOT section:
7702       target->got_section(symtab, layout);
7703       break;
7704
7705     case elfcpp::R_ARM_GOT_BREL:
7706     case elfcpp::R_ARM_GOT_PREL:
7707       {
7708         // The symbol requires a GOT entry.
7709         Arm_output_data_got<big_endian>* got =
7710           target->got_section(symtab, layout);
7711         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7712         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7713           {
7714             // If we are generating a shared object, we need to add a
7715             // dynamic RELATIVE relocation for this symbol's GOT entry.
7716             if (parameters->options().output_is_position_independent())
7717               {
7718                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7719                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7720                 rel_dyn->add_local_relative(
7721                     object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7722                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7723               }
7724           }
7725       }
7726       break;
7727
7728     case elfcpp::R_ARM_TARGET1:
7729     case elfcpp::R_ARM_TARGET2:
7730       // This should have been mapped to another type already.
7731       // Fall through.
7732     case elfcpp::R_ARM_COPY:
7733     case elfcpp::R_ARM_GLOB_DAT:
7734     case elfcpp::R_ARM_JUMP_SLOT:
7735     case elfcpp::R_ARM_RELATIVE:
7736       // These are relocations which should only be seen by the
7737       // dynamic linker, and should never be seen here.
7738       gold_error(_("%s: unexpected reloc %u in object file"),
7739                  object->name().c_str(), r_type);
7740       break;
7741
7742
7743       // These are initial TLS relocs, which are expected when
7744       // linking.
7745     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
7746     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
7747     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
7748     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
7749     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
7750       {
7751         bool output_is_shared = parameters->options().shared();
7752         const tls::Tls_optimization optimized_type
7753             = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7754                                                          r_type);
7755         switch (r_type)
7756           {
7757           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
7758             if (optimized_type == tls::TLSOPT_NONE)
7759               {
7760                 // Create a pair of GOT entries for the module index and
7761                 // dtv-relative offset.
7762                 Arm_output_data_got<big_endian>* got
7763                     = target->got_section(symtab, layout);
7764                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7765                 unsigned int shndx = lsym.get_st_shndx();
7766                 bool is_ordinary;
7767                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7768                 if (!is_ordinary)
7769                   {
7770                     object->error(_("local symbol %u has bad shndx %u"),
7771                                   r_sym, shndx);
7772                     break;
7773                   }
7774
7775                 if (!parameters->doing_static_link())
7776                   got->add_local_pair_with_rel(object, r_sym, shndx,
7777                                                GOT_TYPE_TLS_PAIR,
7778                                                target->rel_dyn_section(layout),
7779                                                elfcpp::R_ARM_TLS_DTPMOD32, 0);
7780                 else
7781                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7782                                                       object, r_sym);
7783               }
7784             else
7785               // FIXME: TLS optimization not supported yet.
7786               gold_unreachable();
7787             break;
7788
7789           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
7790             if (optimized_type == tls::TLSOPT_NONE)
7791               {
7792                 // Create a GOT entry for the module index.
7793                 target->got_mod_index_entry(symtab, layout, object);
7794               }
7795             else
7796               // FIXME: TLS optimization not supported yet.
7797               gold_unreachable();
7798             break;
7799
7800           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
7801             break;
7802
7803           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
7804             layout->set_has_static_tls();
7805             if (optimized_type == tls::TLSOPT_NONE)
7806               {
7807                 // Create a GOT entry for the tp-relative offset.
7808                 Arm_output_data_got<big_endian>* got
7809                   = target->got_section(symtab, layout);
7810                 unsigned int r_sym =
7811                    elfcpp::elf_r_sym<32>(reloc.get_r_info());
7812                 if (!parameters->doing_static_link())
7813                     got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7814                                             target->rel_dyn_section(layout),
7815                                             elfcpp::R_ARM_TLS_TPOFF32);
7816                 else if (!object->local_has_got_offset(r_sym,
7817                                                        GOT_TYPE_TLS_OFFSET))
7818                   {
7819                     got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7820                     unsigned int got_offset =
7821                       object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7822                     got->add_static_reloc(got_offset,
7823                                           elfcpp::R_ARM_TLS_TPOFF32, object,
7824                                           r_sym);
7825                   }
7826               }
7827             else
7828               // FIXME: TLS optimization not supported yet.
7829               gold_unreachable();
7830             break;
7831
7832           case elfcpp::R_ARM_TLS_LE32:          // Local-exec
7833             layout->set_has_static_tls();
7834             if (output_is_shared)
7835               {
7836                 // We need to create a dynamic relocation.
7837                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
7838                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7839                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7840                 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
7841                                    output_section, data_shndx,
7842                                    reloc.get_r_offset());
7843               }
7844             break;
7845
7846           default:
7847             gold_unreachable();
7848           }
7849       }
7850       break;
7851
7852     case elfcpp::R_ARM_PC24:
7853     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7854     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7855     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7856     default:
7857       unsupported_reloc_local(object, r_type);
7858       break;
7859     }
7860 }
7861
7862 // Report an unsupported relocation against a global symbol.
7863
7864 template<bool big_endian>
7865 void
7866 Target_arm<big_endian>::Scan::unsupported_reloc_global(
7867     Sized_relobj<32, big_endian>* object,
7868     unsigned int r_type,
7869     Symbol* gsym)
7870 {
7871   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
7872              object->name().c_str(), r_type, gsym->demangled_name().c_str());
7873 }
7874
7875 template<bool big_endian>
7876 inline bool
7877 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
7878     unsigned int r_type)
7879 {
7880   switch (r_type)
7881     {
7882     case elfcpp::R_ARM_PC24:
7883     case elfcpp::R_ARM_THM_CALL:
7884     case elfcpp::R_ARM_PLT32:
7885     case elfcpp::R_ARM_CALL:
7886     case elfcpp::R_ARM_JUMP24:
7887     case elfcpp::R_ARM_THM_JUMP24:
7888     case elfcpp::R_ARM_SBREL31:
7889     case elfcpp::R_ARM_PREL31:
7890     case elfcpp::R_ARM_THM_JUMP19:
7891     case elfcpp::R_ARM_THM_JUMP6:
7892     case elfcpp::R_ARM_THM_JUMP11:
7893     case elfcpp::R_ARM_THM_JUMP8:
7894       // All the relocations above are branches except SBREL31 and PREL31.
7895       return false;
7896
7897     default:
7898       // Be conservative and assume this is a function pointer.
7899       return true;
7900     }
7901 }
7902
7903 template<bool big_endian>
7904 inline bool
7905 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
7906   Symbol_table*,
7907   Layout*,
7908   Target_arm<big_endian>* target,
7909   Sized_relobj<32, big_endian>*,
7910   unsigned int,
7911   Output_section*,
7912   const elfcpp::Rel<32, big_endian>&,
7913   unsigned int r_type,
7914   const elfcpp::Sym<32, big_endian>&)
7915 {
7916   r_type = target->get_real_reloc_type(r_type);
7917   return possible_function_pointer_reloc(r_type);
7918 }
7919
7920 template<bool big_endian>
7921 inline bool
7922 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
7923   Symbol_table*,
7924   Layout*,
7925   Target_arm<big_endian>* target,
7926   Sized_relobj<32, big_endian>*,
7927   unsigned int,
7928   Output_section*,
7929   const elfcpp::Rel<32, big_endian>&,
7930   unsigned int r_type,
7931   Symbol* gsym)
7932 {
7933   // GOT is not a function.
7934   if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7935     return false;
7936
7937   r_type = target->get_real_reloc_type(r_type);
7938   return possible_function_pointer_reloc(r_type);
7939 }
7940
7941 // Scan a relocation for a global symbol.
7942
7943 template<bool big_endian>
7944 inline void
7945 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
7946                                      Layout* layout,
7947                                      Target_arm* target,
7948                                      Sized_relobj<32, big_endian>* object,
7949                                      unsigned int data_shndx,
7950                                      Output_section* output_section,
7951                                      const elfcpp::Rel<32, big_endian>& reloc,
7952                                      unsigned int r_type,
7953                                      Symbol* gsym)
7954 {
7955   // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
7956   // section.  We check here to avoid creating a dynamic reloc against
7957   // _GLOBAL_OFFSET_TABLE_.
7958   if (!target->has_got_section()
7959       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7960     target->got_section(symtab, layout);
7961
7962   r_type = get_real_reloc_type(r_type);
7963   switch (r_type)
7964     {
7965     case elfcpp::R_ARM_NONE:
7966     case elfcpp::R_ARM_V4BX:
7967     case elfcpp::R_ARM_GNU_VTENTRY:
7968     case elfcpp::R_ARM_GNU_VTINHERIT:
7969       break;
7970
7971     case elfcpp::R_ARM_ABS32:
7972     case elfcpp::R_ARM_ABS16:
7973     case elfcpp::R_ARM_ABS12:
7974     case elfcpp::R_ARM_THM_ABS5:
7975     case elfcpp::R_ARM_ABS8:
7976     case elfcpp::R_ARM_BASE_ABS:
7977     case elfcpp::R_ARM_MOVW_ABS_NC:
7978     case elfcpp::R_ARM_MOVT_ABS:
7979     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7980     case elfcpp::R_ARM_THM_MOVT_ABS:
7981     case elfcpp::R_ARM_ABS32_NOI:
7982       // Absolute addressing relocations.
7983       {
7984         // Make a PLT entry if necessary.
7985         if (this->symbol_needs_plt_entry(gsym))
7986           {
7987             target->make_plt_entry(symtab, layout, gsym);
7988             // Since this is not a PC-relative relocation, we may be
7989             // taking the address of a function. In that case we need to
7990             // set the entry in the dynamic symbol table to the address of
7991             // the PLT entry.
7992             if (gsym->is_from_dynobj() && !parameters->options().shared())
7993               gsym->set_needs_dynsym_value();
7994           }
7995         // Make a dynamic relocation if necessary.
7996         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
7997           {
7998             if (gsym->may_need_copy_reloc())
7999               {
8000                 target->copy_reloc(symtab, layout, object,
8001                                    data_shndx, output_section, gsym, reloc);
8002               }
8003             else if ((r_type == elfcpp::R_ARM_ABS32
8004                       || r_type == elfcpp::R_ARM_ABS32_NOI)
8005                      && gsym->can_use_relative_reloc(false))
8006               {
8007                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8008                 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8009                                              output_section, object,
8010                                              data_shndx, reloc.get_r_offset());
8011               }
8012             else
8013               {
8014                 check_non_pic(object, r_type);
8015                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8016                 rel_dyn->add_global(gsym, r_type, output_section, object,
8017                                     data_shndx, reloc.get_r_offset());
8018               }
8019           }
8020       }
8021       break;
8022
8023     case elfcpp::R_ARM_GOTOFF32:
8024     case elfcpp::R_ARM_GOTOFF12:
8025       // We need a GOT section.
8026       target->got_section(symtab, layout);
8027       break;
8028       
8029     case elfcpp::R_ARM_REL32:
8030     case elfcpp::R_ARM_LDR_PC_G0:
8031     case elfcpp::R_ARM_SBREL32:
8032     case elfcpp::R_ARM_THM_PC8:
8033     case elfcpp::R_ARM_BASE_PREL:
8034     case elfcpp::R_ARM_MOVW_PREL_NC:
8035     case elfcpp::R_ARM_MOVT_PREL:
8036     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8037     case elfcpp::R_ARM_THM_MOVT_PREL:
8038     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8039     case elfcpp::R_ARM_THM_PC12:
8040     case elfcpp::R_ARM_REL32_NOI:
8041     case elfcpp::R_ARM_ALU_PC_G0_NC:
8042     case elfcpp::R_ARM_ALU_PC_G0:
8043     case elfcpp::R_ARM_ALU_PC_G1_NC:
8044     case elfcpp::R_ARM_ALU_PC_G1:
8045     case elfcpp::R_ARM_ALU_PC_G2:
8046     case elfcpp::R_ARM_LDR_PC_G1:
8047     case elfcpp::R_ARM_LDR_PC_G2:
8048     case elfcpp::R_ARM_LDRS_PC_G0:
8049     case elfcpp::R_ARM_LDRS_PC_G1:
8050     case elfcpp::R_ARM_LDRS_PC_G2:
8051     case elfcpp::R_ARM_LDC_PC_G0:
8052     case elfcpp::R_ARM_LDC_PC_G1:
8053     case elfcpp::R_ARM_LDC_PC_G2:
8054     case elfcpp::R_ARM_ALU_SB_G0_NC:
8055     case elfcpp::R_ARM_ALU_SB_G0:
8056     case elfcpp::R_ARM_ALU_SB_G1_NC:
8057     case elfcpp::R_ARM_ALU_SB_G1:
8058     case elfcpp::R_ARM_ALU_SB_G2:
8059     case elfcpp::R_ARM_LDR_SB_G0:
8060     case elfcpp::R_ARM_LDR_SB_G1:
8061     case elfcpp::R_ARM_LDR_SB_G2:
8062     case elfcpp::R_ARM_LDRS_SB_G0:
8063     case elfcpp::R_ARM_LDRS_SB_G1:
8064     case elfcpp::R_ARM_LDRS_SB_G2:
8065     case elfcpp::R_ARM_LDC_SB_G0:
8066     case elfcpp::R_ARM_LDC_SB_G1:
8067     case elfcpp::R_ARM_LDC_SB_G2:
8068     case elfcpp::R_ARM_MOVW_BREL_NC:
8069     case elfcpp::R_ARM_MOVT_BREL:
8070     case elfcpp::R_ARM_MOVW_BREL:
8071     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8072     case elfcpp::R_ARM_THM_MOVT_BREL:
8073     case elfcpp::R_ARM_THM_MOVW_BREL:
8074       // Relative addressing relocations.
8075       {
8076         // Make a dynamic relocation if necessary.
8077         int flags = Symbol::NON_PIC_REF;
8078         if (gsym->needs_dynamic_reloc(flags))
8079           {
8080             if (target->may_need_copy_reloc(gsym))
8081               {
8082                 target->copy_reloc(symtab, layout, object,
8083                                    data_shndx, output_section, gsym, reloc);
8084               }
8085             else
8086               {
8087                 check_non_pic(object, r_type);
8088                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8089                 rel_dyn->add_global(gsym, r_type, output_section, object,
8090                                     data_shndx, reloc.get_r_offset());
8091               }
8092           }
8093       }
8094       break;
8095
8096     case elfcpp::R_ARM_THM_CALL:
8097     case elfcpp::R_ARM_PLT32:
8098     case elfcpp::R_ARM_CALL:
8099     case elfcpp::R_ARM_JUMP24:
8100     case elfcpp::R_ARM_THM_JUMP24:
8101     case elfcpp::R_ARM_SBREL31:
8102     case elfcpp::R_ARM_PREL31:
8103     case elfcpp::R_ARM_THM_JUMP19:
8104     case elfcpp::R_ARM_THM_JUMP6:
8105     case elfcpp::R_ARM_THM_JUMP11:
8106     case elfcpp::R_ARM_THM_JUMP8:
8107       // All the relocation above are branches except for the PREL31 ones.
8108       // A PREL31 relocation can point to a personality function in a shared
8109       // library.  In that case we want to use a PLT because we want to
8110       // call the personality routine and the dyanmic linkers we care about
8111       // do not support dynamic PREL31 relocations. An REL31 relocation may
8112       // point to a function whose unwinding behaviour is being described but
8113       // we will not mistakenly generate a PLT for that because we should use
8114       // a local section symbol.
8115
8116       // If the symbol is fully resolved, this is just a relative
8117       // local reloc.  Otherwise we need a PLT entry.
8118       if (gsym->final_value_is_known())
8119         break;
8120       // If building a shared library, we can also skip the PLT entry
8121       // if the symbol is defined in the output file and is protected
8122       // or hidden.
8123       if (gsym->is_defined()
8124           && !gsym->is_from_dynobj()
8125           && !gsym->is_preemptible())
8126         break;
8127       target->make_plt_entry(symtab, layout, gsym);
8128       break;
8129
8130     case elfcpp::R_ARM_GOT_BREL:
8131     case elfcpp::R_ARM_GOT_ABS:
8132     case elfcpp::R_ARM_GOT_PREL:
8133       {
8134         // The symbol requires a GOT entry.
8135         Arm_output_data_got<big_endian>* got =
8136           target->got_section(symtab, layout);
8137         if (gsym->final_value_is_known())
8138           got->add_global(gsym, GOT_TYPE_STANDARD);
8139         else
8140           {
8141             // If this symbol is not fully resolved, we need to add a
8142             // GOT entry with a dynamic relocation.
8143             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8144             if (gsym->is_from_dynobj()
8145                 || gsym->is_undefined()
8146                 || gsym->is_preemptible())
8147               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8148                                        rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8149             else
8150               {
8151                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8152                   rel_dyn->add_global_relative(
8153                       gsym, elfcpp::R_ARM_RELATIVE, got,
8154                       gsym->got_offset(GOT_TYPE_STANDARD));
8155               }
8156           }
8157       }
8158       break;
8159
8160     case elfcpp::R_ARM_TARGET1:
8161     case elfcpp::R_ARM_TARGET2:
8162       // These should have been mapped to other types already.
8163       // Fall through.
8164     case elfcpp::R_ARM_COPY:
8165     case elfcpp::R_ARM_GLOB_DAT:
8166     case elfcpp::R_ARM_JUMP_SLOT:
8167     case elfcpp::R_ARM_RELATIVE:
8168       // These are relocations which should only be seen by the
8169       // dynamic linker, and should never be seen here.
8170       gold_error(_("%s: unexpected reloc %u in object file"),
8171                  object->name().c_str(), r_type);
8172       break;
8173
8174       // These are initial tls relocs, which are expected when
8175       // linking.
8176     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
8177     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
8178     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
8179     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
8180     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
8181       {
8182         const bool is_final = gsym->final_value_is_known();
8183         const tls::Tls_optimization optimized_type
8184             = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8185         switch (r_type)
8186           {
8187           case elfcpp::R_ARM_TLS_GD32:          // Global-dynamic
8188             if (optimized_type == tls::TLSOPT_NONE)
8189               {
8190                 // Create a pair of GOT entries for the module index and
8191                 // dtv-relative offset.
8192                 Arm_output_data_got<big_endian>* got
8193                     = target->got_section(symtab, layout);
8194                 if (!parameters->doing_static_link())
8195                   got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8196                                                 target->rel_dyn_section(layout),
8197                                                 elfcpp::R_ARM_TLS_DTPMOD32,
8198                                                 elfcpp::R_ARM_TLS_DTPOFF32);
8199                 else
8200                   got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8201               }
8202             else
8203               // FIXME: TLS optimization not supported yet.
8204               gold_unreachable();
8205             break;
8206
8207           case elfcpp::R_ARM_TLS_LDM32:         // Local-dynamic
8208             if (optimized_type == tls::TLSOPT_NONE)
8209               {
8210                 // Create a GOT entry for the module index.
8211                 target->got_mod_index_entry(symtab, layout, object);
8212               }
8213             else
8214               // FIXME: TLS optimization not supported yet.
8215               gold_unreachable();
8216             break;
8217
8218           case elfcpp::R_ARM_TLS_LDO32:         // Alternate local-dynamic
8219             break;
8220
8221           case elfcpp::R_ARM_TLS_IE32:          // Initial-exec
8222             layout->set_has_static_tls();
8223             if (optimized_type == tls::TLSOPT_NONE)
8224               {
8225                 // Create a GOT entry for the tp-relative offset.
8226                 Arm_output_data_got<big_endian>* got
8227                   = target->got_section(symtab, layout);
8228                 if (!parameters->doing_static_link())
8229                   got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8230                                            target->rel_dyn_section(layout),
8231                                            elfcpp::R_ARM_TLS_TPOFF32);
8232                 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8233                   {
8234                     got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8235                     unsigned int got_offset =
8236                        gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8237                     got->add_static_reloc(got_offset,
8238                                           elfcpp::R_ARM_TLS_TPOFF32, gsym);
8239                   }
8240               }
8241             else
8242               // FIXME: TLS optimization not supported yet.
8243               gold_unreachable();
8244             break;
8245
8246           case elfcpp::R_ARM_TLS_LE32:  // Local-exec
8247             layout->set_has_static_tls();
8248             if (parameters->options().shared())
8249               {
8250                 // We need to create a dynamic relocation.
8251                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8252                 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8253                                     output_section, object,
8254                                     data_shndx, reloc.get_r_offset());
8255               }
8256             break;
8257
8258           default:
8259             gold_unreachable();
8260           }
8261       }
8262       break;
8263
8264     case elfcpp::R_ARM_PC24:
8265     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8266     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8267     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8268     default:
8269       unsupported_reloc_global(object, r_type, gsym);
8270       break;
8271     }
8272 }
8273
8274 // Process relocations for gc.
8275
8276 template<bool big_endian>
8277 void
8278 Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
8279                                           Layout* layout,
8280                                           Sized_relobj<32, big_endian>* object,
8281                                           unsigned int data_shndx,
8282                                           unsigned int,
8283                                           const unsigned char* prelocs,
8284                                           size_t reloc_count,
8285                                           Output_section* output_section,
8286                                           bool needs_special_offset_handling,
8287                                           size_t local_symbol_count,
8288                                           const unsigned char* plocal_symbols)
8289 {
8290   typedef Target_arm<big_endian> Arm;
8291   typedef typename Target_arm<big_endian>::Scan Scan;
8292
8293   gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8294                           typename Target_arm::Relocatable_size_for_reloc>(
8295     symtab,
8296     layout,
8297     this,
8298     object,
8299     data_shndx,
8300     prelocs,
8301     reloc_count,
8302     output_section,
8303     needs_special_offset_handling,
8304     local_symbol_count,
8305     plocal_symbols);
8306 }
8307
8308 // Scan relocations for a section.
8309
8310 template<bool big_endian>
8311 void
8312 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8313                                     Layout* layout,
8314                                     Sized_relobj<32, big_endian>* object,
8315                                     unsigned int data_shndx,
8316                                     unsigned int sh_type,
8317                                     const unsigned char* prelocs,
8318                                     size_t reloc_count,
8319                                     Output_section* output_section,
8320                                     bool needs_special_offset_handling,
8321                                     size_t local_symbol_count,
8322                                     const unsigned char* plocal_symbols)
8323 {
8324   typedef typename Target_arm<big_endian>::Scan Scan;
8325   if (sh_type == elfcpp::SHT_RELA)
8326     {
8327       gold_error(_("%s: unsupported RELA reloc section"),
8328                  object->name().c_str());
8329       return;
8330     }
8331
8332   gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8333     symtab,
8334     layout,
8335     this,
8336     object,
8337     data_shndx,
8338     prelocs,
8339     reloc_count,
8340     output_section,
8341     needs_special_offset_handling,
8342     local_symbol_count,
8343     plocal_symbols);
8344 }
8345
8346 // Finalize the sections.
8347
8348 template<bool big_endian>
8349 void
8350 Target_arm<big_endian>::do_finalize_sections(
8351     Layout* layout,
8352     const Input_objects* input_objects,
8353     Symbol_table* symtab)
8354 {
8355   bool merged_any_attributes = false;
8356   // Merge processor-specific flags.
8357   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8358        p != input_objects->relobj_end();
8359        ++p)
8360     {
8361       Arm_relobj<big_endian>* arm_relobj =
8362         Arm_relobj<big_endian>::as_arm_relobj(*p);
8363       if (arm_relobj->merge_flags_and_attributes())
8364         {
8365           this->merge_processor_specific_flags(
8366               arm_relobj->name(),
8367               arm_relobj->processor_specific_flags());
8368           this->merge_object_attributes(arm_relobj->name().c_str(),
8369                                         arm_relobj->attributes_section_data());
8370           merged_any_attributes = true;
8371         }
8372     } 
8373
8374   for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8375        p != input_objects->dynobj_end();
8376        ++p)
8377     {
8378       Arm_dynobj<big_endian>* arm_dynobj =
8379         Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8380       this->merge_processor_specific_flags(
8381           arm_dynobj->name(),
8382           arm_dynobj->processor_specific_flags());
8383       this->merge_object_attributes(arm_dynobj->name().c_str(),
8384                                     arm_dynobj->attributes_section_data());
8385       merged_any_attributes = true;
8386     }
8387
8388   // Create an empty uninitialized attribute section if we still don't have it
8389   // at this moment.  This happens if there is no attributes sections in all
8390   // inputs.
8391   if (this->attributes_section_data_ == NULL)
8392     this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8393
8394   // Check BLX use.
8395   const Object_attribute* cpu_arch_attr =
8396     this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8397   if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
8398     this->set_may_use_blx(true);
8399  
8400   // Check if we need to use Cortex-A8 workaround.
8401   if (parameters->options().user_set_fix_cortex_a8())
8402     this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8403   else
8404     {
8405       // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8406       // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8407       // profile.  
8408       const Object_attribute* cpu_arch_profile_attr =
8409         this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8410       this->fix_cortex_a8_ =
8411         (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8412          && (cpu_arch_profile_attr->int_value() == 'A'
8413              || cpu_arch_profile_attr->int_value() == 0));
8414     }
8415   
8416   // Check if we can use V4BX interworking.
8417   // The V4BX interworking stub contains BX instruction,
8418   // which is not specified for some profiles.
8419   if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8420       && !this->may_use_blx())
8421     gold_error(_("unable to provide V4BX reloc interworking fix up; "
8422                  "the target profile does not support BX instruction"));
8423
8424   // Fill in some more dynamic tags.
8425   const Reloc_section* rel_plt = (this->plt_ == NULL
8426                                   ? NULL
8427                                   : this->plt_->rel_plt());
8428   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8429                                   this->rel_dyn_, true, false);
8430
8431   // Emit any relocs we saved in an attempt to avoid generating COPY
8432   // relocs.
8433   if (this->copy_relocs_.any_saved_relocs())
8434     this->copy_relocs_.emit(this->rel_dyn_section(layout));
8435
8436   // Handle the .ARM.exidx section.
8437   Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8438
8439   if (!parameters->options().relocatable())
8440     {
8441       if (exidx_section != NULL
8442           && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8443         {
8444           // Create __exidx_start and __exdix_end symbols.
8445           symtab->define_in_output_data("__exidx_start", NULL,
8446                                         Symbol_table::PREDEFINED,
8447                                         exidx_section, 0, 0, elfcpp::STT_OBJECT,
8448                                         elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8449                                         0, false, true);
8450           symtab->define_in_output_data("__exidx_end", NULL,
8451                                         Symbol_table::PREDEFINED,
8452                                         exidx_section, 0, 0, elfcpp::STT_OBJECT,
8453                                         elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8454                                         0, true, true);
8455
8456           // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8457           // the .ARM.exidx section.
8458           if (!layout->script_options()->saw_phdrs_clause())
8459             {
8460               gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8461                                                       0)
8462                           == NULL);
8463               Output_segment*  exidx_segment =
8464                 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8465               exidx_segment->add_output_section_to_nonload(exidx_section,
8466                                                            elfcpp::PF_R);
8467             }
8468         }
8469       else
8470         {
8471           symtab->define_as_constant("__exidx_start", NULL,
8472                                      Symbol_table::PREDEFINED,
8473                                      0, 0, elfcpp::STT_OBJECT,
8474                                      elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8475                                      true, false);
8476           symtab->define_as_constant("__exidx_end", NULL,
8477                                      Symbol_table::PREDEFINED,
8478                                      0, 0, elfcpp::STT_OBJECT,
8479                                      elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8480                                      true, false);
8481         }
8482     }
8483
8484   // Create an .ARM.attributes section if we have merged any attributes
8485   // from inputs.
8486   if (merged_any_attributes)
8487     {
8488       Output_attributes_section_data* attributes_section =
8489       new Output_attributes_section_data(*this->attributes_section_data_);
8490       layout->add_output_section_data(".ARM.attributes",
8491                                       elfcpp::SHT_ARM_ATTRIBUTES, 0,
8492                                       attributes_section, ORDER_INVALID,
8493                                       false);
8494     }
8495
8496   // Fix up links in section EXIDX headers.
8497   for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8498        p != layout->section_list().end();
8499        ++p)
8500     if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8501       {
8502         Arm_output_section<big_endian>* os =
8503           Arm_output_section<big_endian>::as_arm_output_section(*p);
8504         os->set_exidx_section_link();
8505       }
8506 }
8507
8508 // Return whether a direct absolute static relocation needs to be applied.
8509 // In cases where Scan::local() or Scan::global() has created
8510 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8511 // of the relocation is carried in the data, and we must not
8512 // apply the static relocation.
8513
8514 template<bool big_endian>
8515 inline bool
8516 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8517     const Sized_symbol<32>* gsym,
8518     int ref_flags,
8519     bool is_32bit,
8520     Output_section* output_section)
8521 {
8522   // If the output section is not allocated, then we didn't call
8523   // scan_relocs, we didn't create a dynamic reloc, and we must apply
8524   // the reloc here.
8525   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8526       return true;
8527
8528   // For local symbols, we will have created a non-RELATIVE dynamic
8529   // relocation only if (a) the output is position independent,
8530   // (b) the relocation is absolute (not pc- or segment-relative), and
8531   // (c) the relocation is not 32 bits wide.
8532   if (gsym == NULL)
8533     return !(parameters->options().output_is_position_independent()
8534              && (ref_flags & Symbol::ABSOLUTE_REF)
8535              && !is_32bit);
8536
8537   // For global symbols, we use the same helper routines used in the
8538   // scan pass.  If we did not create a dynamic relocation, or if we
8539   // created a RELATIVE dynamic relocation, we should apply the static
8540   // relocation.
8541   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8542   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8543                  && gsym->can_use_relative_reloc(ref_flags
8544                                                  & Symbol::FUNCTION_CALL);
8545   return !has_dyn || is_rel;
8546 }
8547
8548 // Perform a relocation.
8549
8550 template<bool big_endian>
8551 inline bool
8552 Target_arm<big_endian>::Relocate::relocate(
8553     const Relocate_info<32, big_endian>* relinfo,
8554     Target_arm* target,
8555     Output_section* output_section,
8556     size_t relnum,
8557     const elfcpp::Rel<32, big_endian>& rel,
8558     unsigned int r_type,
8559     const Sized_symbol<32>* gsym,
8560     const Symbol_value<32>* psymval,
8561     unsigned char* view,
8562     Arm_address address,
8563     section_size_type view_size)
8564 {
8565   typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8566
8567   r_type = get_real_reloc_type(r_type);
8568   const Arm_reloc_property* reloc_property =
8569     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8570   if (reloc_property == NULL)
8571     {
8572       std::string reloc_name =
8573         arm_reloc_property_table->reloc_name_in_error_message(r_type);
8574       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8575                              _("cannot relocate %s in object file"),
8576                              reloc_name.c_str());
8577       return true;
8578     }
8579
8580   const Arm_relobj<big_endian>* object =
8581     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8582
8583   // If the final branch target of a relocation is THUMB instruction, this
8584   // is 1.  Otherwise it is 0.
8585   Arm_address thumb_bit = 0;
8586   Symbol_value<32> symval;
8587   bool is_weakly_undefined_without_plt = false;
8588   bool have_got_offset = false;
8589   unsigned int got_offset = 0;
8590
8591   // If the relocation uses the GOT entry of a symbol instead of the symbol
8592   // itself, we don't care about whether the symbol is defined or what kind
8593   // of symbol it is.
8594   if (reloc_property->uses_got_entry())
8595     {
8596       // Get the GOT offset.
8597       // The GOT pointer points to the end of the GOT section.
8598       // We need to subtract the size of the GOT section to get
8599       // the actual offset to use in the relocation.
8600       // TODO: We should move GOT offset computing code in TLS relocations
8601       // to here.
8602       switch (r_type)
8603         {
8604         case elfcpp::R_ARM_GOT_BREL:
8605         case elfcpp::R_ARM_GOT_PREL:
8606           if (gsym != NULL)
8607             {
8608               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8609               got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8610                             - target->got_size());
8611             }
8612           else
8613             {
8614               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8615               gold_assert(object->local_has_got_offset(r_sym,
8616                                                        GOT_TYPE_STANDARD));
8617               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8618                             - target->got_size());
8619             }
8620           have_got_offset = true;
8621           break;
8622
8623         default:
8624           break;
8625         }
8626     }
8627   else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8628     {
8629       if (gsym != NULL)
8630         {
8631           // This is a global symbol.  Determine if we use PLT and if the
8632           // final target is THUMB.
8633           if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
8634             {
8635               // This uses a PLT, change the symbol value.
8636               symval.set_output_value(target->plt_section()->address()
8637                                       + gsym->plt_offset());
8638               psymval = &symval;
8639             }
8640           else if (gsym->is_weak_undefined())
8641             {
8642               // This is a weakly undefined symbol and we do not use PLT
8643               // for this relocation.  A branch targeting this symbol will
8644               // be converted into an NOP.
8645               is_weakly_undefined_without_plt = true;
8646             }
8647           else if (gsym->is_undefined() && reloc_property->uses_symbol())
8648             {
8649               // This relocation uses the symbol value but the symbol is
8650               // undefined.  Exit early and have the caller reporting an
8651               // error.
8652               return true;
8653             }
8654           else
8655             {
8656               // Set thumb bit if symbol:
8657               // -Has type STT_ARM_TFUNC or
8658               // -Has type STT_FUNC, is defined and with LSB in value set.
8659               thumb_bit =
8660                 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8661                  || (gsym->type() == elfcpp::STT_FUNC
8662                      && !gsym->is_undefined()
8663                      && ((psymval->value(object, 0) & 1) != 0)))
8664                 ? 1
8665                 : 0);
8666             }
8667         }
8668       else
8669         {
8670           // This is a local symbol.  Determine if the final target is THUMB.
8671           // We saved this information when all the local symbols were read.
8672           elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8673           unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8674           thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8675         }
8676     }
8677   else
8678     {
8679       // This is a fake relocation synthesized for a stub.  It does not have
8680       // a real symbol.  We just look at the LSB of the symbol value to
8681       // determine if the target is THUMB or not.
8682       thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8683     }
8684
8685   // Strip LSB if this points to a THUMB target.
8686   if (thumb_bit != 0
8687       && reloc_property->uses_thumb_bit() 
8688       && ((psymval->value(object, 0) & 1) != 0))
8689     {
8690       Arm_address stripped_value =
8691         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8692       symval.set_output_value(stripped_value);
8693       psymval = &symval;
8694     } 
8695
8696   // To look up relocation stubs, we need to pass the symbol table index of
8697   // a local symbol.
8698   unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8699
8700   // Get the addressing origin of the output segment defining the
8701   // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8702   Arm_address sym_origin = 0;
8703   if (reloc_property->uses_symbol_base())
8704     {
8705       if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8706         // R_ARM_BASE_ABS with the NULL symbol will give the
8707         // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8708         // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8709         sym_origin = target->got_plt_section()->address();
8710       else if (gsym == NULL)
8711         sym_origin = 0;
8712       else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8713         sym_origin = gsym->output_segment()->vaddr();
8714       else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8715         sym_origin = gsym->output_data()->address();
8716
8717       // TODO: Assumes the segment base to be zero for the global symbols
8718       // till the proper support for the segment-base-relative addressing
8719       // will be implemented.  This is consistent with GNU ld.
8720     }
8721
8722   // For relative addressing relocation, find out the relative address base.
8723   Arm_address relative_address_base = 0;
8724   switch(reloc_property->relative_address_base())
8725     {
8726     case Arm_reloc_property::RAB_NONE:
8727     // Relocations with relative address bases RAB_TLS and RAB_tp are
8728     // handled by relocate_tls.  So we do not need to do anything here.
8729     case Arm_reloc_property::RAB_TLS:
8730     case Arm_reloc_property::RAB_tp:
8731       break;
8732     case Arm_reloc_property::RAB_B_S:
8733       relative_address_base = sym_origin;
8734       break;
8735     case Arm_reloc_property::RAB_GOT_ORG:
8736       relative_address_base = target->got_plt_section()->address();
8737       break;
8738     case Arm_reloc_property::RAB_P:
8739       relative_address_base = address;
8740       break;
8741     case Arm_reloc_property::RAB_Pa:
8742       relative_address_base = address & 0xfffffffcU;
8743       break;
8744     default:
8745       gold_unreachable(); 
8746     }
8747     
8748   typename Arm_relocate_functions::Status reloc_status =
8749         Arm_relocate_functions::STATUS_OKAY;
8750   bool check_overflow = reloc_property->checks_overflow();
8751   switch (r_type)
8752     {
8753     case elfcpp::R_ARM_NONE:
8754       break;
8755
8756     case elfcpp::R_ARM_ABS8:
8757       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8758                                     output_section))
8759         reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8760       break;
8761
8762     case elfcpp::R_ARM_ABS12:
8763       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8764                                     output_section))
8765         reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8766       break;
8767
8768     case elfcpp::R_ARM_ABS16:
8769       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8770                                     output_section))
8771         reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8772       break;
8773
8774     case elfcpp::R_ARM_ABS32:
8775       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8776                                     output_section))
8777         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8778                                                      thumb_bit);
8779       break;
8780
8781     case elfcpp::R_ARM_ABS32_NOI:
8782       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8783                                     output_section))
8784         // No thumb bit for this relocation: (S + A)
8785         reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8786                                                      0);
8787       break;
8788
8789     case elfcpp::R_ARM_MOVW_ABS_NC:
8790       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8791                                     output_section))
8792         reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8793                                                     0, thumb_bit,
8794                                                     check_overflow);
8795       break;
8796
8797     case elfcpp::R_ARM_MOVT_ABS:
8798       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8799                                     output_section))
8800         reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8801       break;
8802
8803     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8804       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8805                                     output_section))
8806         reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8807                                                         0, thumb_bit, false);
8808       break;
8809
8810     case elfcpp::R_ARM_THM_MOVT_ABS:
8811       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8812                                     output_section))
8813         reloc_status = Arm_relocate_functions::thm_movt(view, object,
8814                                                         psymval, 0);
8815       break;
8816
8817     case elfcpp::R_ARM_MOVW_PREL_NC:
8818     case elfcpp::R_ARM_MOVW_BREL_NC:
8819     case elfcpp::R_ARM_MOVW_BREL:
8820       reloc_status =
8821         Arm_relocate_functions::movw(view, object, psymval,
8822                                      relative_address_base, thumb_bit,
8823                                      check_overflow);
8824       break;
8825
8826     case elfcpp::R_ARM_MOVT_PREL:
8827     case elfcpp::R_ARM_MOVT_BREL:
8828       reloc_status =
8829         Arm_relocate_functions::movt(view, object, psymval,
8830                                      relative_address_base);
8831       break;
8832
8833     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8834     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8835     case elfcpp::R_ARM_THM_MOVW_BREL:
8836       reloc_status =
8837         Arm_relocate_functions::thm_movw(view, object, psymval,
8838                                          relative_address_base,
8839                                          thumb_bit, check_overflow);
8840       break;
8841
8842     case elfcpp::R_ARM_THM_MOVT_PREL:
8843     case elfcpp::R_ARM_THM_MOVT_BREL:
8844       reloc_status =
8845         Arm_relocate_functions::thm_movt(view, object, psymval,
8846                                          relative_address_base);
8847       break;
8848         
8849     case elfcpp::R_ARM_REL32:
8850       reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8851                                                    address, thumb_bit);
8852       break;
8853
8854     case elfcpp::R_ARM_THM_ABS5:
8855       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8856                                     output_section))
8857         reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
8858       break;
8859
8860     // Thumb long branches.
8861     case elfcpp::R_ARM_THM_CALL:
8862     case elfcpp::R_ARM_THM_XPC22:
8863     case elfcpp::R_ARM_THM_JUMP24:
8864       reloc_status =
8865         Arm_relocate_functions::thumb_branch_common(
8866             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8867             thumb_bit, is_weakly_undefined_without_plt);
8868       break;
8869
8870     case elfcpp::R_ARM_GOTOFF32:
8871       {
8872         Arm_address got_origin;
8873         got_origin = target->got_plt_section()->address();
8874         reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8875                                                      got_origin, thumb_bit);
8876       }
8877       break;
8878
8879     case elfcpp::R_ARM_BASE_PREL:
8880       gold_assert(gsym != NULL);
8881       reloc_status =
8882           Arm_relocate_functions::base_prel(view, sym_origin, address);
8883       break;
8884
8885     case elfcpp::R_ARM_BASE_ABS:
8886       {
8887         if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8888                                       output_section))
8889           break;
8890
8891         reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
8892       }
8893       break;
8894
8895     case elfcpp::R_ARM_GOT_BREL:
8896       gold_assert(have_got_offset);
8897       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
8898       break;
8899
8900     case elfcpp::R_ARM_GOT_PREL:
8901       gold_assert(have_got_offset);
8902       // Get the address origin for GOT PLT, which is allocated right
8903       // after the GOT section, to calculate an absolute address of
8904       // the symbol GOT entry (got_origin + got_offset).
8905       Arm_address got_origin;
8906       got_origin = target->got_plt_section()->address();
8907       reloc_status = Arm_relocate_functions::got_prel(view,
8908                                                       got_origin + got_offset,
8909                                                       address);
8910       break;
8911
8912     case elfcpp::R_ARM_PLT32:
8913     case elfcpp::R_ARM_CALL:
8914     case elfcpp::R_ARM_JUMP24:
8915     case elfcpp::R_ARM_XPC25:
8916       gold_assert(gsym == NULL
8917                   || gsym->has_plt_offset()
8918                   || gsym->final_value_is_known()
8919                   || (gsym->is_defined()
8920                       && !gsym->is_from_dynobj()
8921                       && !gsym->is_preemptible()));
8922       reloc_status =
8923         Arm_relocate_functions::arm_branch_common(
8924             r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8925             thumb_bit, is_weakly_undefined_without_plt);
8926       break;
8927
8928     case elfcpp::R_ARM_THM_JUMP19:
8929       reloc_status =
8930         Arm_relocate_functions::thm_jump19(view, object, psymval, address,
8931                                            thumb_bit);
8932       break;
8933
8934     case elfcpp::R_ARM_THM_JUMP6:
8935       reloc_status =
8936         Arm_relocate_functions::thm_jump6(view, object, psymval, address);
8937       break;
8938
8939     case elfcpp::R_ARM_THM_JUMP8:
8940       reloc_status =
8941         Arm_relocate_functions::thm_jump8(view, object, psymval, address);
8942       break;
8943
8944     case elfcpp::R_ARM_THM_JUMP11:
8945       reloc_status =
8946         Arm_relocate_functions::thm_jump11(view, object, psymval, address);
8947       break;
8948
8949     case elfcpp::R_ARM_PREL31:
8950       reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
8951                                                     address, thumb_bit);
8952       break;
8953
8954     case elfcpp::R_ARM_V4BX:
8955       if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
8956         {
8957           const bool is_v4bx_interworking =
8958               (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
8959           reloc_status =
8960             Arm_relocate_functions::v4bx(relinfo, view, object, address,
8961                                          is_v4bx_interworking);
8962         }
8963       break;
8964
8965     case elfcpp::R_ARM_THM_PC8:
8966       reloc_status =
8967         Arm_relocate_functions::thm_pc8(view, object, psymval, address);
8968       break;
8969
8970     case elfcpp::R_ARM_THM_PC12:
8971       reloc_status =
8972         Arm_relocate_functions::thm_pc12(view, object, psymval, address);
8973       break;
8974
8975     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8976       reloc_status =
8977         Arm_relocate_functions::thm_alu11(view, object, psymval, address,
8978                                           thumb_bit);
8979       break;
8980
8981     case elfcpp::R_ARM_ALU_PC_G0_NC:
8982     case elfcpp::R_ARM_ALU_PC_G0:
8983     case elfcpp::R_ARM_ALU_PC_G1_NC:
8984     case elfcpp::R_ARM_ALU_PC_G1:
8985     case elfcpp::R_ARM_ALU_PC_G2:
8986     case elfcpp::R_ARM_ALU_SB_G0_NC:
8987     case elfcpp::R_ARM_ALU_SB_G0:
8988     case elfcpp::R_ARM_ALU_SB_G1_NC:
8989     case elfcpp::R_ARM_ALU_SB_G1:
8990     case elfcpp::R_ARM_ALU_SB_G2:
8991       reloc_status =
8992         Arm_relocate_functions::arm_grp_alu(view, object, psymval,
8993                                             reloc_property->group_index(),
8994                                             relative_address_base,
8995                                             thumb_bit, check_overflow);
8996       break;
8997
8998     case elfcpp::R_ARM_LDR_PC_G0:
8999     case elfcpp::R_ARM_LDR_PC_G1:
9000     case elfcpp::R_ARM_LDR_PC_G2:
9001     case elfcpp::R_ARM_LDR_SB_G0:
9002     case elfcpp::R_ARM_LDR_SB_G1:
9003     case elfcpp::R_ARM_LDR_SB_G2:
9004       reloc_status =
9005           Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9006                                               reloc_property->group_index(),
9007                                               relative_address_base);
9008       break;
9009
9010     case elfcpp::R_ARM_LDRS_PC_G0:
9011     case elfcpp::R_ARM_LDRS_PC_G1:
9012     case elfcpp::R_ARM_LDRS_PC_G2:
9013     case elfcpp::R_ARM_LDRS_SB_G0:
9014     case elfcpp::R_ARM_LDRS_SB_G1:
9015     case elfcpp::R_ARM_LDRS_SB_G2:
9016       reloc_status =
9017           Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9018                                                reloc_property->group_index(),
9019                                                relative_address_base);
9020       break;
9021
9022     case elfcpp::R_ARM_LDC_PC_G0:
9023     case elfcpp::R_ARM_LDC_PC_G1:
9024     case elfcpp::R_ARM_LDC_PC_G2:
9025     case elfcpp::R_ARM_LDC_SB_G0:
9026     case elfcpp::R_ARM_LDC_SB_G1:
9027     case elfcpp::R_ARM_LDC_SB_G2:
9028       reloc_status =
9029           Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9030                                               reloc_property->group_index(),
9031                                               relative_address_base);
9032       break;
9033
9034       // These are initial tls relocs, which are expected when
9035       // linking.
9036     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9037     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9038     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9039     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9040     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9041       reloc_status =
9042         this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9043                            view, address, view_size);
9044       break;
9045
9046     // The known and unknown unsupported and/or deprecated relocations.
9047     case elfcpp::R_ARM_PC24:
9048     case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9049     case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9050     case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9051     default:
9052       // Just silently leave the method. We should get an appropriate error
9053       // message in the scan methods.
9054       break;
9055     }
9056
9057   // Report any errors.
9058   switch (reloc_status)
9059     {
9060     case Arm_relocate_functions::STATUS_OKAY:
9061       break;
9062     case Arm_relocate_functions::STATUS_OVERFLOW:
9063       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9064                              _("relocation overflow in %s"),
9065                              reloc_property->name().c_str());
9066       break;
9067     case Arm_relocate_functions::STATUS_BAD_RELOC:
9068       gold_error_at_location(
9069         relinfo,
9070         relnum,
9071         rel.get_r_offset(),
9072         _("unexpected opcode while processing relocation %s"),
9073         reloc_property->name().c_str());
9074       break;
9075     default:
9076       gold_unreachable();
9077     }
9078
9079   return true;
9080 }
9081
9082 // Perform a TLS relocation.
9083
9084 template<bool big_endian>
9085 inline typename Arm_relocate_functions<big_endian>::Status
9086 Target_arm<big_endian>::Relocate::relocate_tls(
9087     const Relocate_info<32, big_endian>* relinfo,
9088     Target_arm<big_endian>* target,
9089     size_t relnum,
9090     const elfcpp::Rel<32, big_endian>& rel,
9091     unsigned int r_type,
9092     const Sized_symbol<32>* gsym,
9093     const Symbol_value<32>* psymval,
9094     unsigned char* view,
9095     elfcpp::Elf_types<32>::Elf_Addr address,
9096     section_size_type /*view_size*/ )
9097 {
9098   typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9099   typedef Relocate_functions<32, big_endian> RelocFuncs;
9100   Output_segment* tls_segment = relinfo->layout->tls_segment();
9101
9102   const Sized_relobj<32, big_endian>* object = relinfo->object;
9103
9104   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9105
9106   const bool is_final = (gsym == NULL
9107                          ? !parameters->options().shared()
9108                          : gsym->final_value_is_known());
9109   const tls::Tls_optimization optimized_type
9110       = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9111   switch (r_type)
9112     {
9113     case elfcpp::R_ARM_TLS_GD32:        // Global-dynamic
9114         {
9115           unsigned int got_type = GOT_TYPE_TLS_PAIR;
9116           unsigned int got_offset;
9117           if (gsym != NULL)
9118             {
9119               gold_assert(gsym->has_got_offset(got_type));
9120               got_offset = gsym->got_offset(got_type) - target->got_size();
9121             }
9122           else
9123             {
9124               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9125               gold_assert(object->local_has_got_offset(r_sym, got_type));
9126               got_offset = (object->local_got_offset(r_sym, got_type)
9127                             - target->got_size());
9128             }
9129           if (optimized_type == tls::TLSOPT_NONE)
9130             {
9131               Arm_address got_entry =
9132                 target->got_plt_section()->address() + got_offset;
9133               
9134               // Relocate the field with the PC relative offset of the pair of
9135               // GOT entries.
9136               RelocFuncs::pcrel32(view, got_entry, address);
9137               return ArmRelocFuncs::STATUS_OKAY;
9138             }
9139         }
9140       break;
9141
9142     case elfcpp::R_ARM_TLS_LDM32:       // Local-dynamic
9143       if (optimized_type == tls::TLSOPT_NONE)
9144         {
9145           // Relocate the field with the offset of the GOT entry for
9146           // the module index.
9147           unsigned int got_offset;
9148           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9149                         - target->got_size());
9150           Arm_address got_entry =
9151             target->got_plt_section()->address() + got_offset;
9152
9153           // Relocate the field with the PC relative offset of the pair of
9154           // GOT entries.
9155           RelocFuncs::pcrel32(view, got_entry, address);
9156           return ArmRelocFuncs::STATUS_OKAY;
9157         }
9158       break;
9159
9160     case elfcpp::R_ARM_TLS_LDO32:       // Alternate local-dynamic
9161       RelocFuncs::rel32(view, value);
9162       return ArmRelocFuncs::STATUS_OKAY;
9163
9164     case elfcpp::R_ARM_TLS_IE32:        // Initial-exec
9165       if (optimized_type == tls::TLSOPT_NONE)
9166         {
9167           // Relocate the field with the offset of the GOT entry for
9168           // the tp-relative offset of the symbol.
9169           unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9170           unsigned int got_offset;
9171           if (gsym != NULL)
9172             {
9173               gold_assert(gsym->has_got_offset(got_type));
9174               got_offset = gsym->got_offset(got_type);
9175             }
9176           else
9177             {
9178               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9179               gold_assert(object->local_has_got_offset(r_sym, got_type));
9180               got_offset = object->local_got_offset(r_sym, got_type);
9181             }
9182
9183           // All GOT offsets are relative to the end of the GOT.
9184           got_offset -= target->got_size();
9185
9186           Arm_address got_entry =
9187             target->got_plt_section()->address() + got_offset;
9188
9189           // Relocate the field with the PC relative offset of the GOT entry.
9190           RelocFuncs::pcrel32(view, got_entry, address);
9191           return ArmRelocFuncs::STATUS_OKAY;
9192         }
9193       break;
9194
9195     case elfcpp::R_ARM_TLS_LE32:        // Local-exec
9196       // If we're creating a shared library, a dynamic relocation will
9197       // have been created for this location, so do not apply it now.
9198       if (!parameters->options().shared())
9199         {
9200           gold_assert(tls_segment != NULL);
9201
9202           // $tp points to the TCB, which is followed by the TLS, so we
9203           // need to add TCB size to the offset.
9204           Arm_address aligned_tcb_size =
9205             align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9206           RelocFuncs::rel32(view, value + aligned_tcb_size);
9207
9208         }
9209       return ArmRelocFuncs::STATUS_OKAY;
9210     
9211     default:
9212       gold_unreachable();
9213     }
9214
9215   gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9216                          _("unsupported reloc %u"),
9217                          r_type);
9218   return ArmRelocFuncs::STATUS_BAD_RELOC;
9219 }
9220
9221 // Relocate section data.
9222
9223 template<bool big_endian>
9224 void
9225 Target_arm<big_endian>::relocate_section(
9226     const Relocate_info<32, big_endian>* relinfo,
9227     unsigned int sh_type,
9228     const unsigned char* prelocs,
9229     size_t reloc_count,
9230     Output_section* output_section,
9231     bool needs_special_offset_handling,
9232     unsigned char* view,
9233     Arm_address address,
9234     section_size_type view_size,
9235     const Reloc_symbol_changes* reloc_symbol_changes)
9236 {
9237   typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9238   gold_assert(sh_type == elfcpp::SHT_REL);
9239
9240   // See if we are relocating a relaxed input section.  If so, the view
9241   // covers the whole output section and we need to adjust accordingly.
9242   if (needs_special_offset_handling)
9243     {
9244       const Output_relaxed_input_section* poris =
9245         output_section->find_relaxed_input_section(relinfo->object,
9246                                                    relinfo->data_shndx);
9247       if (poris != NULL)
9248         {
9249           Arm_address section_address = poris->address();
9250           section_size_type section_size = poris->data_size();
9251
9252           gold_assert((section_address >= address)
9253                       && ((section_address + section_size)
9254                           <= (address + view_size)));
9255
9256           off_t offset = section_address - address;
9257           view += offset;
9258           address += offset;
9259           view_size = section_size;
9260         }
9261     }
9262
9263   gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9264                          Arm_relocate>(
9265     relinfo,
9266     this,
9267     prelocs,
9268     reloc_count,
9269     output_section,
9270     needs_special_offset_handling,
9271     view,
9272     address,
9273     view_size,
9274     reloc_symbol_changes);
9275 }
9276
9277 // Return the size of a relocation while scanning during a relocatable
9278 // link.
9279
9280 template<bool big_endian>
9281 unsigned int
9282 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9283     unsigned int r_type,
9284     Relobj* object)
9285 {
9286   r_type = get_real_reloc_type(r_type);
9287   const Arm_reloc_property* arp =
9288       arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9289   if (arp != NULL)
9290     return arp->size();
9291   else
9292     {
9293       std::string reloc_name =
9294         arm_reloc_property_table->reloc_name_in_error_message(r_type);
9295       gold_error(_("%s: unexpected %s in object file"),
9296                  object->name().c_str(), reloc_name.c_str());
9297       return 0;
9298     }
9299 }
9300
9301 // Scan the relocs during a relocatable link.
9302
9303 template<bool big_endian>
9304 void
9305 Target_arm<big_endian>::scan_relocatable_relocs(
9306     Symbol_table* symtab,
9307     Layout* layout,
9308     Sized_relobj<32, big_endian>* object,
9309     unsigned int data_shndx,
9310     unsigned int sh_type,
9311     const unsigned char* prelocs,
9312     size_t reloc_count,
9313     Output_section* output_section,
9314     bool needs_special_offset_handling,
9315     size_t local_symbol_count,
9316     const unsigned char* plocal_symbols,
9317     Relocatable_relocs* rr)
9318 {
9319   gold_assert(sh_type == elfcpp::SHT_REL);
9320
9321   typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9322     Relocatable_size_for_reloc> Scan_relocatable_relocs;
9323
9324   gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9325       Scan_relocatable_relocs>(
9326     symtab,
9327     layout,
9328     object,
9329     data_shndx,
9330     prelocs,
9331     reloc_count,
9332     output_section,
9333     needs_special_offset_handling,
9334     local_symbol_count,
9335     plocal_symbols,
9336     rr);
9337 }
9338
9339 // Relocate a section during a relocatable link.
9340
9341 template<bool big_endian>
9342 void
9343 Target_arm<big_endian>::relocate_for_relocatable(
9344     const Relocate_info<32, big_endian>* relinfo,
9345     unsigned int sh_type,
9346     const unsigned char* prelocs,
9347     size_t reloc_count,
9348     Output_section* output_section,
9349     off_t offset_in_output_section,
9350     const Relocatable_relocs* rr,
9351     unsigned char* view,
9352     Arm_address view_address,
9353     section_size_type view_size,
9354     unsigned char* reloc_view,
9355     section_size_type reloc_view_size)
9356 {
9357   gold_assert(sh_type == elfcpp::SHT_REL);
9358
9359   gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
9360     relinfo,
9361     prelocs,
9362     reloc_count,
9363     output_section,
9364     offset_in_output_section,
9365     rr,
9366     view,
9367     view_address,
9368     view_size,
9369     reloc_view,
9370     reloc_view_size);
9371 }
9372
9373 // Perform target-specific processing in a relocatable link.  This is
9374 // only used if we use the relocation strategy RELOC_SPECIAL.
9375
9376 template<bool big_endian>
9377 void
9378 Target_arm<big_endian>::relocate_special_relocatable(
9379     const Relocate_info<32, big_endian>* relinfo,
9380     unsigned int sh_type,
9381     const unsigned char* preloc_in,
9382     size_t relnum,
9383     Output_section* output_section,
9384     off_t offset_in_output_section,
9385     unsigned char* view,
9386     elfcpp::Elf_types<32>::Elf_Addr view_address,
9387     section_size_type,
9388     unsigned char* preloc_out)
9389 {
9390   // We can only handle REL type relocation sections.
9391   gold_assert(sh_type == elfcpp::SHT_REL);
9392
9393   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9394   typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9395     Reltype_write;
9396   const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9397
9398   const Arm_relobj<big_endian>* object =
9399     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9400   const unsigned int local_count = object->local_symbol_count();
9401
9402   Reltype reloc(preloc_in);
9403   Reltype_write reloc_write(preloc_out);
9404
9405   elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9406   const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9407   const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9408
9409   const Arm_reloc_property* arp =
9410     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9411   gold_assert(arp != NULL);
9412
9413   // Get the new symbol index.
9414   // We only use RELOC_SPECIAL strategy in local relocations.
9415   gold_assert(r_sym < local_count);
9416
9417   // We are adjusting a section symbol.  We need to find
9418   // the symbol table index of the section symbol for
9419   // the output section corresponding to input section
9420   // in which this symbol is defined.
9421   bool is_ordinary;
9422   unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9423   gold_assert(is_ordinary);
9424   Output_section* os = object->output_section(shndx);
9425   gold_assert(os != NULL);
9426   gold_assert(os->needs_symtab_index());
9427   unsigned int new_symndx = os->symtab_index();
9428
9429   // Get the new offset--the location in the output section where
9430   // this relocation should be applied.
9431
9432   Arm_address offset = reloc.get_r_offset();
9433   Arm_address new_offset;
9434   if (offset_in_output_section != invalid_address)
9435     new_offset = offset + offset_in_output_section;
9436   else
9437     {
9438       section_offset_type sot_offset =
9439           convert_types<section_offset_type, Arm_address>(offset);
9440       section_offset_type new_sot_offset =
9441           output_section->output_offset(object, relinfo->data_shndx,
9442                                         sot_offset);
9443       gold_assert(new_sot_offset != -1);
9444       new_offset = new_sot_offset;
9445     }
9446
9447   // In an object file, r_offset is an offset within the section.
9448   // In an executable or dynamic object, generated by
9449   // --emit-relocs, r_offset is an absolute address.
9450   if (!parameters->options().relocatable())
9451     {
9452       new_offset += view_address;
9453       if (offset_in_output_section != invalid_address)
9454         new_offset -= offset_in_output_section;
9455     }
9456
9457   reloc_write.put_r_offset(new_offset);
9458   reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9459
9460   // Handle the reloc addend.
9461   // The relocation uses a section symbol in the input file.
9462   // We are adjusting it to use a section symbol in the output
9463   // file.  The input section symbol refers to some address in
9464   // the input section.  We need the relocation in the output
9465   // file to refer to that same address.  This adjustment to
9466   // the addend is the same calculation we use for a simple
9467   // absolute relocation for the input section symbol.
9468
9469   const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9470
9471   // Handle THUMB bit.
9472   Symbol_value<32> symval;
9473   Arm_address thumb_bit =
9474      object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9475   if (thumb_bit != 0
9476       && arp->uses_thumb_bit() 
9477       && ((psymval->value(object, 0) & 1) != 0))
9478     {
9479       Arm_address stripped_value =
9480         psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9481       symval.set_output_value(stripped_value);
9482       psymval = &symval;
9483     } 
9484
9485   unsigned char* paddend = view + offset;
9486   typename Arm_relocate_functions<big_endian>::Status reloc_status =
9487         Arm_relocate_functions<big_endian>::STATUS_OKAY;
9488   switch (r_type)
9489     {
9490     case elfcpp::R_ARM_ABS8:
9491       reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9492                                                               psymval);
9493       break;
9494
9495     case elfcpp::R_ARM_ABS12:
9496       reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9497                                                                psymval);
9498       break;
9499
9500     case elfcpp::R_ARM_ABS16:
9501       reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9502                                                                psymval);
9503       break;
9504
9505     case elfcpp::R_ARM_THM_ABS5:
9506       reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9507                                                                   object,
9508                                                                   psymval);
9509       break;
9510
9511     case elfcpp::R_ARM_MOVW_ABS_NC:
9512     case elfcpp::R_ARM_MOVW_PREL_NC:
9513     case elfcpp::R_ARM_MOVW_BREL_NC:
9514     case elfcpp::R_ARM_MOVW_BREL:
9515       reloc_status = Arm_relocate_functions<big_endian>::movw(
9516           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9517       break;
9518
9519     case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9520     case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9521     case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9522     case elfcpp::R_ARM_THM_MOVW_BREL:
9523       reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9524           paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9525       break;
9526
9527     case elfcpp::R_ARM_THM_CALL:
9528     case elfcpp::R_ARM_THM_XPC22:
9529     case elfcpp::R_ARM_THM_JUMP24:
9530       reloc_status =
9531         Arm_relocate_functions<big_endian>::thumb_branch_common(
9532             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9533             false);
9534       break;
9535
9536     case elfcpp::R_ARM_PLT32:
9537     case elfcpp::R_ARM_CALL:
9538     case elfcpp::R_ARM_JUMP24:
9539     case elfcpp::R_ARM_XPC25:
9540       reloc_status =
9541         Arm_relocate_functions<big_endian>::arm_branch_common(
9542             r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9543             false);
9544       break;
9545
9546     case elfcpp::R_ARM_THM_JUMP19:
9547       reloc_status =
9548         Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9549                                                        psymval, 0, thumb_bit);
9550       break;
9551
9552     case elfcpp::R_ARM_THM_JUMP6:
9553       reloc_status =
9554         Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9555                                                       0);
9556       break;
9557
9558     case elfcpp::R_ARM_THM_JUMP8:
9559       reloc_status =
9560         Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9561                                                       0);
9562       break;
9563
9564     case elfcpp::R_ARM_THM_JUMP11:
9565       reloc_status =
9566         Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9567                                                        0);
9568       break;
9569
9570     case elfcpp::R_ARM_PREL31:
9571       reloc_status =
9572         Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9573                                                    thumb_bit);
9574       break;
9575
9576     case elfcpp::R_ARM_THM_PC8:
9577       reloc_status =
9578         Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9579                                                     0);
9580       break;
9581
9582     case elfcpp::R_ARM_THM_PC12:
9583       reloc_status =
9584         Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9585                                                      0);
9586       break;
9587
9588     case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9589       reloc_status =
9590         Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9591                                                       0, thumb_bit);
9592       break;
9593
9594     // These relocation truncate relocation results so we cannot handle them
9595     // in a relocatable link.
9596     case elfcpp::R_ARM_MOVT_ABS:
9597     case elfcpp::R_ARM_THM_MOVT_ABS:
9598     case elfcpp::R_ARM_MOVT_PREL:
9599     case elfcpp::R_ARM_MOVT_BREL:
9600     case elfcpp::R_ARM_THM_MOVT_PREL:
9601     case elfcpp::R_ARM_THM_MOVT_BREL:
9602     case elfcpp::R_ARM_ALU_PC_G0_NC:
9603     case elfcpp::R_ARM_ALU_PC_G0:
9604     case elfcpp::R_ARM_ALU_PC_G1_NC:
9605     case elfcpp::R_ARM_ALU_PC_G1:
9606     case elfcpp::R_ARM_ALU_PC_G2:
9607     case elfcpp::R_ARM_ALU_SB_G0_NC:
9608     case elfcpp::R_ARM_ALU_SB_G0:
9609     case elfcpp::R_ARM_ALU_SB_G1_NC:
9610     case elfcpp::R_ARM_ALU_SB_G1:
9611     case elfcpp::R_ARM_ALU_SB_G2:
9612     case elfcpp::R_ARM_LDR_PC_G0:
9613     case elfcpp::R_ARM_LDR_PC_G1:
9614     case elfcpp::R_ARM_LDR_PC_G2:
9615     case elfcpp::R_ARM_LDR_SB_G0:
9616     case elfcpp::R_ARM_LDR_SB_G1:
9617     case elfcpp::R_ARM_LDR_SB_G2:
9618     case elfcpp::R_ARM_LDRS_PC_G0:
9619     case elfcpp::R_ARM_LDRS_PC_G1:
9620     case elfcpp::R_ARM_LDRS_PC_G2:
9621     case elfcpp::R_ARM_LDRS_SB_G0:
9622     case elfcpp::R_ARM_LDRS_SB_G1:
9623     case elfcpp::R_ARM_LDRS_SB_G2:
9624     case elfcpp::R_ARM_LDC_PC_G0:
9625     case elfcpp::R_ARM_LDC_PC_G1:
9626     case elfcpp::R_ARM_LDC_PC_G2:
9627     case elfcpp::R_ARM_LDC_SB_G0:
9628     case elfcpp::R_ARM_LDC_SB_G1:
9629     case elfcpp::R_ARM_LDC_SB_G2:
9630       gold_error(_("cannot handle %s in a relocatable link"),
9631                  arp->name().c_str());
9632       break;
9633
9634     default:
9635       gold_unreachable();
9636     }
9637
9638   // Report any errors.
9639   switch (reloc_status)
9640     {
9641     case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9642       break;
9643     case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9644       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9645                              _("relocation overflow in %s"),
9646                              arp->name().c_str());
9647       break;
9648     case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9649       gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9650         _("unexpected opcode while processing relocation %s"),
9651         arp->name().c_str());
9652       break;
9653     default:
9654       gold_unreachable();
9655     }
9656 }
9657
9658 // Return the value to use for a dynamic symbol which requires special
9659 // treatment.  This is how we support equality comparisons of function
9660 // pointers across shared library boundaries, as described in the
9661 // processor specific ABI supplement.
9662
9663 template<bool big_endian>
9664 uint64_t
9665 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9666 {
9667   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9668   return this->plt_section()->address() + gsym->plt_offset();
9669 }
9670
9671 // Map platform-specific relocs to real relocs
9672 //
9673 template<bool big_endian>
9674 unsigned int
9675 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9676 {
9677   switch (r_type)
9678     {
9679     case elfcpp::R_ARM_TARGET1:
9680       // This is either R_ARM_ABS32 or R_ARM_REL32;
9681       return elfcpp::R_ARM_ABS32;
9682
9683     case elfcpp::R_ARM_TARGET2:
9684       // This can be any reloc type but ususally is R_ARM_GOT_PREL
9685       return elfcpp::R_ARM_GOT_PREL;
9686
9687     default:
9688       return r_type;
9689     }
9690 }
9691
9692 // Whether if two EABI versions V1 and V2 are compatible.
9693
9694 template<bool big_endian>
9695 bool
9696 Target_arm<big_endian>::are_eabi_versions_compatible(
9697     elfcpp::Elf_Word v1,
9698     elfcpp::Elf_Word v2)
9699 {
9700   // v4 and v5 are the same spec before and after it was released,
9701   // so allow mixing them.
9702   if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9703       || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9704       || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9705     return true;
9706
9707   return v1 == v2;
9708 }
9709
9710 // Combine FLAGS from an input object called NAME and the processor-specific
9711 // flags in the ELF header of the output.  Much of this is adapted from the
9712 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9713 // in bfd/elf32-arm.c.
9714
9715 template<bool big_endian>
9716 void
9717 Target_arm<big_endian>::merge_processor_specific_flags(
9718     const std::string& name,
9719     elfcpp::Elf_Word flags)
9720 {
9721   if (this->are_processor_specific_flags_set())
9722     {
9723       elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9724
9725       // Nothing to merge if flags equal to those in output.
9726       if (flags == out_flags)
9727         return;
9728
9729       // Complain about various flag mismatches.
9730       elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9731       elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9732       if (!this->are_eabi_versions_compatible(version1, version2)
9733           && parameters->options().warn_mismatch())
9734         gold_error(_("Source object %s has EABI version %d but output has "
9735                      "EABI version %d."),
9736                    name.c_str(),
9737                    (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9738                    (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9739     }
9740   else
9741     {
9742       // If the input is the default architecture and had the default
9743       // flags then do not bother setting the flags for the output
9744       // architecture, instead allow future merges to do this.  If no
9745       // future merges ever set these flags then they will retain their
9746       // uninitialised values, which surprise surprise, correspond
9747       // to the default values.
9748       if (flags == 0)
9749         return;
9750
9751       // This is the first time, just copy the flags.
9752       // We only copy the EABI version for now.
9753       this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9754     }
9755 }
9756
9757 // Adjust ELF file header.
9758 template<bool big_endian>
9759 void
9760 Target_arm<big_endian>::do_adjust_elf_header(
9761     unsigned char* view,
9762     int len) const
9763 {
9764   gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9765
9766   elfcpp::Ehdr<32, big_endian> ehdr(view);
9767   unsigned char e_ident[elfcpp::EI_NIDENT];
9768   memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9769
9770   if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9771       == elfcpp::EF_ARM_EABI_UNKNOWN)
9772     e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9773   else
9774     e_ident[elfcpp::EI_OSABI] = 0;
9775   e_ident[elfcpp::EI_ABIVERSION] = 0;
9776
9777   // FIXME: Do EF_ARM_BE8 adjustment.
9778
9779   elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9780   oehdr.put_e_ident(e_ident);
9781 }
9782
9783 // do_make_elf_object to override the same function in the base class.
9784 // We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
9785 // to store ARM specific information.  Hence we need to have our own
9786 // ELF object creation.
9787
9788 template<bool big_endian>
9789 Object*
9790 Target_arm<big_endian>::do_make_elf_object(
9791     const std::string& name,
9792     Input_file* input_file,
9793     off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9794 {
9795   int et = ehdr.get_e_type();
9796   if (et == elfcpp::ET_REL)
9797     {
9798       Arm_relobj<big_endian>* obj =
9799         new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9800       obj->setup();
9801       return obj;
9802     }
9803   else if (et == elfcpp::ET_DYN)
9804     {
9805       Sized_dynobj<32, big_endian>* obj =
9806         new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9807       obj->setup();
9808       return obj;
9809     }
9810   else
9811     {
9812       gold_error(_("%s: unsupported ELF file type %d"),
9813                  name.c_str(), et);
9814       return NULL;
9815     }
9816 }
9817
9818 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9819 // Returns -1 if no architecture could be read.
9820 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9821
9822 template<bool big_endian>
9823 int
9824 Target_arm<big_endian>::get_secondary_compatible_arch(
9825     const Attributes_section_data* pasd)
9826 {
9827   const Object_attribute* known_attributes =
9828     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9829
9830   // Note: the tag and its argument below are uleb128 values, though
9831   // currently-defined values fit in one byte for each.
9832   const std::string& sv =
9833     known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9834   if (sv.size() == 2
9835       && sv.data()[0] == elfcpp::Tag_CPU_arch
9836       && (sv.data()[1] & 128) != 128)
9837    return sv.data()[1];
9838
9839   // This tag is "safely ignorable", so don't complain if it looks funny.
9840   return -1;
9841 }
9842
9843 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
9844 // The tag is removed if ARCH is -1.
9845 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
9846
9847 template<bool big_endian>
9848 void
9849 Target_arm<big_endian>::set_secondary_compatible_arch(
9850     Attributes_section_data* pasd,
9851     int arch)
9852 {
9853   Object_attribute* known_attributes =
9854     pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9855
9856   if (arch == -1)
9857     {
9858       known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
9859       return;
9860     }
9861
9862   // Note: the tag and its argument below are uleb128 values, though
9863   // currently-defined values fit in one byte for each.
9864   char sv[3];
9865   sv[0] = elfcpp::Tag_CPU_arch;
9866   gold_assert(arch != 0);
9867   sv[1] = arch;
9868   sv[2] = '\0';
9869
9870   known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
9871 }
9872
9873 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
9874 // into account.
9875 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
9876
9877 template<bool big_endian>
9878 int
9879 Target_arm<big_endian>::tag_cpu_arch_combine(
9880     const char* name,
9881     int oldtag,
9882     int* secondary_compat_out,
9883     int newtag,
9884     int secondary_compat)
9885 {
9886 #define T(X) elfcpp::TAG_CPU_ARCH_##X
9887   static const int v6t2[] =
9888     {
9889       T(V6T2),   // PRE_V4.
9890       T(V6T2),   // V4.
9891       T(V6T2),   // V4T.
9892       T(V6T2),   // V5T.
9893       T(V6T2),   // V5TE.
9894       T(V6T2),   // V5TEJ.
9895       T(V6T2),   // V6.
9896       T(V7),     // V6KZ.
9897       T(V6T2)    // V6T2.
9898     };
9899   static const int v6k[] =
9900     {
9901       T(V6K),    // PRE_V4.
9902       T(V6K),    // V4.
9903       T(V6K),    // V4T.
9904       T(V6K),    // V5T.
9905       T(V6K),    // V5TE.
9906       T(V6K),    // V5TEJ.
9907       T(V6K),    // V6.
9908       T(V6KZ),   // V6KZ.
9909       T(V7),     // V6T2.
9910       T(V6K)     // V6K.
9911     };
9912   static const int v7[] =
9913     {
9914       T(V7),     // PRE_V4.
9915       T(V7),     // V4.
9916       T(V7),     // V4T.
9917       T(V7),     // V5T.
9918       T(V7),     // V5TE.
9919       T(V7),     // V5TEJ.
9920       T(V7),     // V6.
9921       T(V7),     // V6KZ.
9922       T(V7),     // V6T2.
9923       T(V7),     // V6K.
9924       T(V7)      // V7.
9925     };
9926   static const int v6_m[] =
9927     {
9928       -1,        // PRE_V4.
9929       -1,        // V4.
9930       T(V6K),    // V4T.
9931       T(V6K),    // V5T.
9932       T(V6K),    // V5TE.
9933       T(V6K),    // V5TEJ.
9934       T(V6K),    // V6.
9935       T(V6KZ),   // V6KZ.
9936       T(V7),     // V6T2.
9937       T(V6K),    // V6K.
9938       T(V7),     // V7.
9939       T(V6_M)    // V6_M.
9940     };
9941   static const int v6s_m[] =
9942     {
9943       -1,        // PRE_V4.
9944       -1,        // V4.
9945       T(V6K),    // V4T.
9946       T(V6K),    // V5T.
9947       T(V6K),    // V5TE.
9948       T(V6K),    // V5TEJ.
9949       T(V6K),    // V6.
9950       T(V6KZ),   // V6KZ.
9951       T(V7),     // V6T2.
9952       T(V6K),    // V6K.
9953       T(V7),     // V7.
9954       T(V6S_M),  // V6_M.
9955       T(V6S_M)   // V6S_M.
9956     };
9957   static const int v7e_m[] =
9958     {
9959       -1,       // PRE_V4.
9960       -1,       // V4.
9961       T(V7E_M), // V4T.
9962       T(V7E_M), // V5T.
9963       T(V7E_M), // V5TE.
9964       T(V7E_M), // V5TEJ.
9965       T(V7E_M), // V6.
9966       T(V7E_M), // V6KZ.
9967       T(V7E_M), // V6T2.
9968       T(V7E_M), // V6K.
9969       T(V7E_M), // V7.
9970       T(V7E_M), // V6_M.
9971       T(V7E_M), // V6S_M.
9972       T(V7E_M)  // V7E_M.
9973     };
9974   static const int v4t_plus_v6_m[] =
9975     {
9976       -1,               // PRE_V4.
9977       -1,               // V4.
9978       T(V4T),           // V4T.
9979       T(V5T),           // V5T.
9980       T(V5TE),          // V5TE.
9981       T(V5TEJ),         // V5TEJ.
9982       T(V6),            // V6.
9983       T(V6KZ),          // V6KZ.
9984       T(V6T2),          // V6T2.
9985       T(V6K),           // V6K.
9986       T(V7),            // V7.
9987       T(V6_M),          // V6_M.
9988       T(V6S_M),         // V6S_M.
9989       T(V7E_M),         // V7E_M.
9990       T(V4T_PLUS_V6_M)  // V4T plus V6_M.
9991     };
9992   static const int* comb[] =
9993     {
9994       v6t2,
9995       v6k,
9996       v7,
9997       v6_m,
9998       v6s_m,
9999       v7e_m,
10000       // Pseudo-architecture.
10001       v4t_plus_v6_m
10002     };
10003
10004   // Check we've not got a higher architecture than we know about.
10005
10006   if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH)
10007     {
10008       gold_error(_("%s: unknown CPU architecture"), name);
10009       return -1;
10010     }
10011
10012   // Override old tag if we have a Tag_also_compatible_with on the output.
10013
10014   if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10015       || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10016     oldtag = T(V4T_PLUS_V6_M);
10017
10018   // And override the new tag if we have a Tag_also_compatible_with on the
10019   // input.
10020
10021   if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10022       || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10023     newtag = T(V4T_PLUS_V6_M);
10024
10025   // Architectures before V6KZ add features monotonically.
10026   int tagh = std::max(oldtag, newtag);
10027   if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10028     return tagh;
10029
10030   int tagl = std::min(oldtag, newtag);
10031   int result = comb[tagh - T(V6T2)][tagl];
10032
10033   // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10034   // as the canonical version.
10035   if (result == T(V4T_PLUS_V6_M))
10036     {
10037       result = T(V4T);
10038       *secondary_compat_out = T(V6_M);
10039     }
10040   else
10041     *secondary_compat_out = -1;
10042
10043   if (result == -1)
10044     {
10045       gold_error(_("%s: conflicting CPU architectures %d/%d"),
10046                  name, oldtag, newtag);
10047       return -1;
10048     }
10049
10050   return result;
10051 #undef T
10052 }
10053
10054 // Helper to print AEABI enum tag value.
10055
10056 template<bool big_endian>
10057 std::string
10058 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10059 {
10060   static const char* aeabi_enum_names[] =
10061     { "", "variable-size", "32-bit", "" };
10062   const size_t aeabi_enum_names_size =
10063     sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10064
10065   if (value < aeabi_enum_names_size)
10066     return std::string(aeabi_enum_names[value]);
10067   else
10068     {
10069       char buffer[100];
10070       sprintf(buffer, "<unknown value %u>", value);
10071       return std::string(buffer);
10072     }
10073 }
10074
10075 // Return the string value to store in TAG_CPU_name.
10076
10077 template<bool big_endian>
10078 std::string
10079 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10080 {
10081   static const char* name_table[] = {
10082     // These aren't real CPU names, but we can't guess
10083     // that from the architecture version alone.
10084    "Pre v4",
10085    "ARM v4",
10086    "ARM v4T",
10087    "ARM v5T",
10088    "ARM v5TE",
10089    "ARM v5TEJ",
10090    "ARM v6",
10091    "ARM v6KZ",
10092    "ARM v6T2",
10093    "ARM v6K",
10094    "ARM v7",
10095    "ARM v6-M",
10096    "ARM v6S-M",
10097    "ARM v7E-M"
10098  };
10099  const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10100
10101   if (value < name_table_size)
10102     return std::string(name_table[value]);
10103   else
10104     {
10105       char buffer[100];
10106       sprintf(buffer, "<unknown CPU value %u>", value);
10107       return std::string(buffer);
10108     } 
10109 }
10110
10111 // Merge object attributes from input file called NAME with those of the
10112 // output.  The input object attributes are in the object pointed by PASD.
10113
10114 template<bool big_endian>
10115 void
10116 Target_arm<big_endian>::merge_object_attributes(
10117     const char* name,
10118     const Attributes_section_data* pasd)
10119 {
10120   // Return if there is no attributes section data.
10121   if (pasd == NULL)
10122     return;
10123
10124   // If output has no object attributes, just copy.
10125   const int vendor = Object_attribute::OBJ_ATTR_PROC;
10126   if (this->attributes_section_data_ == NULL)
10127     {
10128       this->attributes_section_data_ = new Attributes_section_data(*pasd);
10129       Object_attribute* out_attr =
10130         this->attributes_section_data_->known_attributes(vendor);
10131
10132       // We do not output objects with Tag_MPextension_use_legacy - we move
10133       //  the attribute's value to Tag_MPextension_use.  */
10134       if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10135         {
10136           if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10137               && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10138                 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10139             {
10140               gold_error(_("%s has both the current and legacy "
10141                            "Tag_MPextension_use attributes"),
10142                          name);
10143             }
10144
10145           out_attr[elfcpp::Tag_MPextension_use] =
10146             out_attr[elfcpp::Tag_MPextension_use_legacy];
10147           out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10148           out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10149         }
10150
10151       return;
10152     }
10153
10154   const Object_attribute* in_attr = pasd->known_attributes(vendor);
10155   Object_attribute* out_attr =
10156     this->attributes_section_data_->known_attributes(vendor);
10157
10158   // This needs to happen before Tag_ABI_FP_number_model is merged.  */
10159   if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10160       != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10161     {
10162       // Ignore mismatches if the object doesn't use floating point.  */
10163       if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10164         out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10165             in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10166       else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10167                && parameters->options().warn_mismatch())
10168         gold_error(_("%s uses VFP register arguments, output does not"),
10169                    name);
10170     }
10171
10172   for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10173     {
10174       // Merge this attribute with existing attributes.
10175       switch (i)
10176         {
10177         case elfcpp::Tag_CPU_raw_name:
10178         case elfcpp::Tag_CPU_name:
10179           // These are merged after Tag_CPU_arch.
10180           break;
10181
10182         case elfcpp::Tag_ABI_optimization_goals:
10183         case elfcpp::Tag_ABI_FP_optimization_goals:
10184           // Use the first value seen.
10185           break;
10186
10187         case elfcpp::Tag_CPU_arch:
10188           {
10189             unsigned int saved_out_attr = out_attr->int_value();
10190             // Merge Tag_CPU_arch and Tag_also_compatible_with.
10191             int secondary_compat =
10192               this->get_secondary_compatible_arch(pasd);
10193             int secondary_compat_out =
10194               this->get_secondary_compatible_arch(
10195                   this->attributes_section_data_);
10196             out_attr[i].set_int_value(
10197                 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10198                                      &secondary_compat_out,
10199                                      in_attr[i].int_value(),
10200                                      secondary_compat));
10201             this->set_secondary_compatible_arch(this->attributes_section_data_,
10202                                                 secondary_compat_out);
10203
10204             // Merge Tag_CPU_name and Tag_CPU_raw_name.
10205             if (out_attr[i].int_value() == saved_out_attr)
10206               ; // Leave the names alone.
10207             else if (out_attr[i].int_value() == in_attr[i].int_value())
10208               {
10209                 // The output architecture has been changed to match the
10210                 // input architecture.  Use the input names.
10211                 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10212                     in_attr[elfcpp::Tag_CPU_name].string_value());
10213                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10214                     in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10215               }
10216             else
10217               {
10218                 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10219                 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10220               }
10221
10222             // If we still don't have a value for Tag_CPU_name,
10223             // make one up now.  Tag_CPU_raw_name remains blank.
10224             if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10225               {
10226                 const std::string cpu_name =
10227                   this->tag_cpu_name_value(out_attr[i].int_value());
10228                 // FIXME:  If we see an unknown CPU, this will be set
10229                 // to "<unknown CPU n>", where n is the attribute value.
10230                 // This is different from BFD, which leaves the name alone.
10231                 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10232               }
10233           }
10234           break;
10235
10236         case elfcpp::Tag_ARM_ISA_use:
10237         case elfcpp::Tag_THUMB_ISA_use:
10238         case elfcpp::Tag_WMMX_arch:
10239         case elfcpp::Tag_Advanced_SIMD_arch:
10240           // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10241         case elfcpp::Tag_ABI_FP_rounding:
10242         case elfcpp::Tag_ABI_FP_exceptions:
10243         case elfcpp::Tag_ABI_FP_user_exceptions:
10244         case elfcpp::Tag_ABI_FP_number_model:
10245         case elfcpp::Tag_VFP_HP_extension:
10246         case elfcpp::Tag_CPU_unaligned_access:
10247         case elfcpp::Tag_T2EE_use:
10248         case elfcpp::Tag_Virtualization_use:
10249         case elfcpp::Tag_MPextension_use:
10250           // Use the largest value specified.
10251           if (in_attr[i].int_value() > out_attr[i].int_value())
10252             out_attr[i].set_int_value(in_attr[i].int_value());
10253           break;
10254
10255         case elfcpp::Tag_ABI_align8_preserved:
10256         case elfcpp::Tag_ABI_PCS_RO_data:
10257           // Use the smallest value specified.
10258           if (in_attr[i].int_value() < out_attr[i].int_value())
10259             out_attr[i].set_int_value(in_attr[i].int_value());
10260           break;
10261
10262         case elfcpp::Tag_ABI_align8_needed:
10263           if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10264               && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10265                   || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10266                       == 0)))
10267             {
10268               // This error message should be enabled once all non-conformant
10269               // binaries in the toolchain have had the attributes set
10270               // properly.
10271               // gold_error(_("output 8-byte data alignment conflicts with %s"),
10272               //            name);
10273             }
10274           // Fall through.
10275         case elfcpp::Tag_ABI_FP_denormal:
10276         case elfcpp::Tag_ABI_PCS_GOT_use:
10277           {
10278             // These tags have 0 = don't care, 1 = strong requirement,
10279             // 2 = weak requirement.
10280             static const int order_021[3] = {0, 2, 1};
10281
10282             // Use the "greatest" from the sequence 0, 2, 1, or the largest
10283             // value if greater than 2 (for future-proofing).
10284             if ((in_attr[i].int_value() > 2
10285                  && in_attr[i].int_value() > out_attr[i].int_value())
10286                 || (in_attr[i].int_value() <= 2
10287                     && out_attr[i].int_value() <= 2
10288                     && (order_021[in_attr[i].int_value()]
10289                         > order_021[out_attr[i].int_value()])))
10290               out_attr[i].set_int_value(in_attr[i].int_value());
10291           }
10292           break;
10293
10294         case elfcpp::Tag_CPU_arch_profile:
10295           if (out_attr[i].int_value() != in_attr[i].int_value())
10296             {
10297               // 0 will merge with anything.
10298               // 'A' and 'S' merge to 'A'.
10299               // 'R' and 'S' merge to 'R'.
10300               // 'M' and 'A|R|S' is an error.
10301               if (out_attr[i].int_value() == 0
10302                   || (out_attr[i].int_value() == 'S'
10303                       && (in_attr[i].int_value() == 'A'
10304                           || in_attr[i].int_value() == 'R')))
10305                 out_attr[i].set_int_value(in_attr[i].int_value());
10306               else if (in_attr[i].int_value() == 0
10307                        || (in_attr[i].int_value() == 'S'
10308                            && (out_attr[i].int_value() == 'A'
10309                                || out_attr[i].int_value() == 'R')))
10310                 ; // Do nothing.
10311               else if (parameters->options().warn_mismatch())
10312                 {
10313                   gold_error
10314                     (_("conflicting architecture profiles %c/%c"),
10315                      in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10316                      out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10317                 }
10318             }
10319           break;
10320         case elfcpp::Tag_VFP_arch:
10321             {
10322               static const struct
10323               {
10324                   int ver;
10325                   int regs;
10326               } vfp_versions[7] =
10327                 {
10328                   {0, 0},
10329                   {1, 16},
10330                   {2, 16},
10331                   {3, 32},
10332                   {3, 16},
10333                   {4, 32},
10334                   {4, 16}
10335                 };
10336
10337               // Values greater than 6 aren't defined, so just pick the
10338               // biggest.
10339               if (in_attr[i].int_value() > 6
10340                   && in_attr[i].int_value() > out_attr[i].int_value())
10341                 {
10342                   *out_attr = *in_attr;
10343                   break;
10344                 }
10345               // The output uses the superset of input features
10346               // (ISA version) and registers.
10347               int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10348                                  vfp_versions[out_attr[i].int_value()].ver);
10349               int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10350                                   vfp_versions[out_attr[i].int_value()].regs);
10351               // This assumes all possible supersets are also a valid
10352               // options.
10353               int newval;
10354               for (newval = 6; newval > 0; newval--)
10355                 {
10356                   if (regs == vfp_versions[newval].regs
10357                       && ver == vfp_versions[newval].ver)
10358                     break;
10359                 }
10360               out_attr[i].set_int_value(newval);
10361             }
10362           break;
10363         case elfcpp::Tag_PCS_config:
10364           if (out_attr[i].int_value() == 0)
10365             out_attr[i].set_int_value(in_attr[i].int_value());
10366           else if (in_attr[i].int_value() != 0
10367                    && out_attr[i].int_value() != 0
10368                    && parameters->options().warn_mismatch())
10369             {
10370               // It's sometimes ok to mix different configs, so this is only
10371               // a warning.
10372               gold_warning(_("%s: conflicting platform configuration"), name);
10373             }
10374           break;
10375         case elfcpp::Tag_ABI_PCS_R9_use:
10376           if (in_attr[i].int_value() != out_attr[i].int_value()
10377               && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10378               && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10379               && parameters->options().warn_mismatch())
10380             {
10381               gold_error(_("%s: conflicting use of R9"), name);
10382             }
10383           if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10384             out_attr[i].set_int_value(in_attr[i].int_value());
10385           break;
10386         case elfcpp::Tag_ABI_PCS_RW_data:
10387           if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10388               && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10389                   != elfcpp::AEABI_R9_SB)
10390               && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10391                   != elfcpp::AEABI_R9_unused)
10392               && parameters->options().warn_mismatch())
10393             {
10394               gold_error(_("%s: SB relative addressing conflicts with use "
10395                            "of R9"),
10396                            name);
10397             }
10398           // Use the smallest value specified.
10399           if (in_attr[i].int_value() < out_attr[i].int_value())
10400             out_attr[i].set_int_value(in_attr[i].int_value());
10401           break;
10402         case elfcpp::Tag_ABI_PCS_wchar_t:
10403           if (out_attr[i].int_value()
10404               && in_attr[i].int_value()
10405               && out_attr[i].int_value() != in_attr[i].int_value()
10406               && parameters->options().warn_mismatch()
10407               && parameters->options().wchar_size_warning())
10408             {
10409               gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10410                              "use %u-byte wchar_t; use of wchar_t values "
10411                              "across objects may fail"),
10412                            name, in_attr[i].int_value(),
10413                            out_attr[i].int_value());
10414             }
10415           else if (in_attr[i].int_value() && !out_attr[i].int_value())
10416             out_attr[i].set_int_value(in_attr[i].int_value());
10417           break;
10418         case elfcpp::Tag_ABI_enum_size:
10419           if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10420             {
10421               if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10422                   || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10423                 {
10424                   // The existing object is compatible with anything.
10425                   // Use whatever requirements the new object has.
10426                   out_attr[i].set_int_value(in_attr[i].int_value());
10427                 }
10428               else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10429                        && out_attr[i].int_value() != in_attr[i].int_value()
10430                        && parameters->options().warn_mismatch()
10431                        && parameters->options().enum_size_warning())
10432                 {
10433                   unsigned int in_value = in_attr[i].int_value();
10434                   unsigned int out_value = out_attr[i].int_value();
10435                   gold_warning(_("%s uses %s enums yet the output is to use "
10436                                  "%s enums; use of enum values across objects "
10437                                  "may fail"),
10438                                name,
10439                                this->aeabi_enum_name(in_value).c_str(),
10440                                this->aeabi_enum_name(out_value).c_str());
10441                 }
10442             }
10443           break;
10444         case elfcpp::Tag_ABI_VFP_args:
10445           // Aready done.
10446           break;
10447         case elfcpp::Tag_ABI_WMMX_args:
10448           if (in_attr[i].int_value() != out_attr[i].int_value()
10449               && parameters->options().warn_mismatch())
10450             {
10451               gold_error(_("%s uses iWMMXt register arguments, output does "
10452                            "not"),
10453                          name);
10454             }
10455           break;
10456         case Object_attribute::Tag_compatibility:
10457           // Merged in target-independent code.
10458           break;
10459         case elfcpp::Tag_ABI_HardFP_use:
10460           // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10461           if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10462               || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10463             out_attr[i].set_int_value(3);
10464           else if (in_attr[i].int_value() > out_attr[i].int_value())
10465             out_attr[i].set_int_value(in_attr[i].int_value());
10466           break;
10467         case elfcpp::Tag_ABI_FP_16bit_format:
10468           if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10469             {
10470               if (in_attr[i].int_value() != out_attr[i].int_value()
10471                   && parameters->options().warn_mismatch())
10472                 gold_error(_("fp16 format mismatch between %s and output"),
10473                            name);
10474             }
10475           if (in_attr[i].int_value() != 0)
10476             out_attr[i].set_int_value(in_attr[i].int_value());
10477           break;
10478
10479         case elfcpp::Tag_DIV_use:
10480           // This tag is set to zero if we can use UDIV and SDIV in Thumb
10481           // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10482           // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10483           // CPU.  We will merge as follows: If the input attribute's value
10484           // is one then the output attribute's value remains unchanged.  If
10485           // the input attribute's value is zero or two then if the output
10486           // attribute's value is one the output value is set to the input
10487           // value, otherwise the output value must be the same as the
10488           // inputs.  */ 
10489           if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1) 
10490             { 
10491               if (in_attr[i].int_value() != out_attr[i].int_value())
10492                 {
10493                   gold_error(_("DIV usage mismatch between %s and output"),
10494                              name);
10495                 }
10496             } 
10497
10498           if (in_attr[i].int_value() != 1)
10499             out_attr[i].set_int_value(in_attr[i].int_value()); 
10500           
10501           break;
10502
10503         case elfcpp::Tag_MPextension_use_legacy:
10504           // We don't output objects with Tag_MPextension_use_legacy - we
10505           // move the value to Tag_MPextension_use.
10506           if (in_attr[i].int_value() != 0
10507               && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10508             {
10509               if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10510                   != in_attr[i].int_value())
10511                 {
10512                   gold_error(_("%s has has both the current and legacy "
10513                                "Tag_MPextension_use attributes"), 
10514                              name);
10515                 }
10516             }
10517
10518           if (in_attr[i].int_value()
10519               > out_attr[elfcpp::Tag_MPextension_use].int_value())
10520             out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10521
10522           break;
10523
10524         case elfcpp::Tag_nodefaults:
10525           // This tag is set if it exists, but the value is unused (and is
10526           // typically zero).  We don't actually need to do anything here -
10527           // the merge happens automatically when the type flags are merged
10528           // below.
10529           break;
10530         case elfcpp::Tag_also_compatible_with:
10531           // Already done in Tag_CPU_arch.
10532           break;
10533         case elfcpp::Tag_conformance:
10534           // Keep the attribute if it matches.  Throw it away otherwise.
10535           // No attribute means no claim to conform.
10536           if (in_attr[i].string_value() != out_attr[i].string_value())
10537             out_attr[i].set_string_value("");
10538           break;
10539
10540         default:
10541           {
10542             const char* err_object = NULL;
10543
10544             // The "known_obj_attributes" table does contain some undefined
10545             // attributes.  Ensure that there are unused.
10546             if (out_attr[i].int_value() != 0
10547                 || out_attr[i].string_value() != "")
10548               err_object = "output";
10549             else if (in_attr[i].int_value() != 0
10550                      || in_attr[i].string_value() != "")
10551               err_object = name;
10552
10553             if (err_object != NULL
10554                 && parameters->options().warn_mismatch())
10555               {
10556                 // Attribute numbers >=64 (mod 128) can be safely ignored.
10557                 if ((i & 127) < 64)
10558                   gold_error(_("%s: unknown mandatory EABI object attribute "
10559                                "%d"),
10560                              err_object, i);
10561                 else
10562                   gold_warning(_("%s: unknown EABI object attribute %d"),
10563                                err_object, i);
10564               }
10565
10566             // Only pass on attributes that match in both inputs.
10567             if (!in_attr[i].matches(out_attr[i]))
10568               {
10569                 out_attr[i].set_int_value(0);
10570                 out_attr[i].set_string_value("");
10571               }
10572           }
10573         }
10574
10575       // If out_attr was copied from in_attr then it won't have a type yet.
10576       if (in_attr[i].type() && !out_attr[i].type())
10577         out_attr[i].set_type(in_attr[i].type());
10578     }
10579
10580   // Merge Tag_compatibility attributes and any common GNU ones.
10581   this->attributes_section_data_->merge(name, pasd);
10582
10583   // Check for any attributes not known on ARM.
10584   typedef Vendor_object_attributes::Other_attributes Other_attributes;
10585   const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10586   Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10587   Other_attributes* out_other_attributes =
10588     this->attributes_section_data_->other_attributes(vendor);
10589   Other_attributes::iterator out_iter = out_other_attributes->begin();
10590
10591   while (in_iter != in_other_attributes->end()
10592          || out_iter != out_other_attributes->end())
10593     {
10594       const char* err_object = NULL;
10595       int err_tag = 0;
10596
10597       // The tags for each list are in numerical order.
10598       // If the tags are equal, then merge.
10599       if (out_iter != out_other_attributes->end()
10600           && (in_iter == in_other_attributes->end()
10601               || in_iter->first > out_iter->first))
10602         {
10603           // This attribute only exists in output.  We can't merge, and we
10604           // don't know what the tag means, so delete it.
10605           err_object = "output";
10606           err_tag = out_iter->first;
10607           int saved_tag = out_iter->first;
10608           delete out_iter->second;
10609           out_other_attributes->erase(out_iter); 
10610           out_iter = out_other_attributes->upper_bound(saved_tag);
10611         }
10612       else if (in_iter != in_other_attributes->end()
10613                && (out_iter != out_other_attributes->end()
10614                    || in_iter->first < out_iter->first))
10615         {
10616           // This attribute only exists in input. We can't merge, and we
10617           // don't know what the tag means, so ignore it.
10618           err_object = name;
10619           err_tag = in_iter->first;
10620           ++in_iter;
10621         }
10622       else // The tags are equal.
10623         {
10624           // As present, all attributes in the list are unknown, and
10625           // therefore can't be merged meaningfully.
10626           err_object = "output";
10627           err_tag = out_iter->first;
10628
10629           //  Only pass on attributes that match in both inputs.
10630           if (!in_iter->second->matches(*(out_iter->second)))
10631             {
10632               // No match.  Delete the attribute.
10633               int saved_tag = out_iter->first;
10634               delete out_iter->second;
10635               out_other_attributes->erase(out_iter);
10636               out_iter = out_other_attributes->upper_bound(saved_tag);
10637             }
10638           else
10639             {
10640               // Matched.  Keep the attribute and move to the next.
10641               ++out_iter;
10642               ++in_iter;
10643             }
10644         }
10645
10646       if (err_object && parameters->options().warn_mismatch())
10647         {
10648           // Attribute numbers >=64 (mod 128) can be safely ignored.  */
10649           if ((err_tag & 127) < 64)
10650             {
10651               gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10652                          err_object, err_tag);
10653             }
10654           else
10655             {
10656               gold_warning(_("%s: unknown EABI object attribute %d"),
10657                            err_object, err_tag);
10658             }
10659         }
10660     }
10661 }
10662
10663 // Stub-generation methods for Target_arm.
10664
10665 // Make a new Arm_input_section object.
10666
10667 template<bool big_endian>
10668 Arm_input_section<big_endian>*
10669 Target_arm<big_endian>::new_arm_input_section(
10670     Relobj* relobj,
10671     unsigned int shndx)
10672 {
10673   Section_id sid(relobj, shndx);
10674
10675   Arm_input_section<big_endian>* arm_input_section =
10676     new Arm_input_section<big_endian>(relobj, shndx);
10677   arm_input_section->init();
10678
10679   // Register new Arm_input_section in map for look-up.
10680   std::pair<typename Arm_input_section_map::iterator, bool> ins =
10681     this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10682
10683   // Make sure that it we have not created another Arm_input_section
10684   // for this input section already.
10685   gold_assert(ins.second);
10686
10687   return arm_input_section; 
10688 }
10689
10690 // Find the Arm_input_section object corresponding to the SHNDX-th input
10691 // section of RELOBJ.
10692
10693 template<bool big_endian>
10694 Arm_input_section<big_endian>*
10695 Target_arm<big_endian>::find_arm_input_section(
10696     Relobj* relobj,
10697     unsigned int shndx) const
10698 {
10699   Section_id sid(relobj, shndx);
10700   typename Arm_input_section_map::const_iterator p =
10701     this->arm_input_section_map_.find(sid);
10702   return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10703 }
10704
10705 // Make a new stub table.
10706
10707 template<bool big_endian>
10708 Stub_table<big_endian>*
10709 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10710 {
10711   Stub_table<big_endian>* stub_table =
10712     new Stub_table<big_endian>(owner);
10713   this->stub_tables_.push_back(stub_table);
10714
10715   stub_table->set_address(owner->address() + owner->data_size());
10716   stub_table->set_file_offset(owner->offset() + owner->data_size());
10717   stub_table->finalize_data_size();
10718
10719   return stub_table;
10720 }
10721
10722 // Scan a relocation for stub generation.
10723
10724 template<bool big_endian>
10725 void
10726 Target_arm<big_endian>::scan_reloc_for_stub(
10727     const Relocate_info<32, big_endian>* relinfo,
10728     unsigned int r_type,
10729     const Sized_symbol<32>* gsym,
10730     unsigned int r_sym,
10731     const Symbol_value<32>* psymval,
10732     elfcpp::Elf_types<32>::Elf_Swxword addend,
10733     Arm_address address)
10734 {
10735   typedef typename Target_arm<big_endian>::Relocate Relocate;
10736
10737   const Arm_relobj<big_endian>* arm_relobj =
10738     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10739
10740   bool target_is_thumb;
10741   Symbol_value<32> symval;
10742   if (gsym != NULL)
10743     {
10744       // This is a global symbol.  Determine if we use PLT and if the
10745       // final target is THUMB.
10746       if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
10747         {
10748           // This uses a PLT, change the symbol value.
10749           symval.set_output_value(this->plt_section()->address()
10750                                   + gsym->plt_offset());
10751           psymval = &symval;
10752           target_is_thumb = false;
10753         }
10754       else if (gsym->is_undefined())
10755         // There is no need to generate a stub symbol is undefined.
10756         return;
10757       else
10758         {
10759           target_is_thumb =
10760             ((gsym->type() == elfcpp::STT_ARM_TFUNC)
10761              || (gsym->type() == elfcpp::STT_FUNC
10762                  && !gsym->is_undefined()
10763                  && ((psymval->value(arm_relobj, 0) & 1) != 0)));
10764         }
10765     }
10766   else
10767     {
10768       // This is a local symbol.  Determine if the final target is THUMB.
10769       target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10770     }
10771
10772   // Strip LSB if this points to a THUMB target.
10773   const Arm_reloc_property* reloc_property =
10774     arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10775   gold_assert(reloc_property != NULL);
10776   if (target_is_thumb
10777       && reloc_property->uses_thumb_bit()
10778       && ((psymval->value(arm_relobj, 0) & 1) != 0))
10779     {
10780       Arm_address stripped_value =
10781         psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10782       symval.set_output_value(stripped_value);
10783       psymval = &symval;
10784     } 
10785
10786   // Get the symbol value.
10787   Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10788
10789   // Owing to pipelining, the PC relative branches below actually skip
10790   // two instructions when the branch offset is 0.
10791   Arm_address destination;
10792   switch (r_type)
10793     {
10794     case elfcpp::R_ARM_CALL:
10795     case elfcpp::R_ARM_JUMP24:
10796     case elfcpp::R_ARM_PLT32:
10797       // ARM branches.
10798       destination = value + addend + 8;
10799       break;
10800     case elfcpp::R_ARM_THM_CALL:
10801     case elfcpp::R_ARM_THM_XPC22:
10802     case elfcpp::R_ARM_THM_JUMP24:
10803     case elfcpp::R_ARM_THM_JUMP19:
10804       // THUMB branches.
10805       destination = value + addend + 4;
10806       break;
10807     default:
10808       gold_unreachable();
10809     }
10810
10811   Reloc_stub* stub = NULL;
10812   Stub_type stub_type =
10813     Reloc_stub::stub_type_for_reloc(r_type, address, destination,
10814                                     target_is_thumb);
10815   if (stub_type != arm_stub_none)
10816     {
10817       // Try looking up an existing stub from a stub table.
10818       Stub_table<big_endian>* stub_table = 
10819         arm_relobj->stub_table(relinfo->data_shndx);
10820       gold_assert(stub_table != NULL);
10821    
10822       // Locate stub by destination.
10823       Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
10824
10825       // Create a stub if there is not one already
10826       stub = stub_table->find_reloc_stub(stub_key);
10827       if (stub == NULL)
10828         {
10829           // create a new stub and add it to stub table.
10830           stub = this->stub_factory().make_reloc_stub(stub_type);
10831           stub_table->add_reloc_stub(stub, stub_key);
10832         }
10833
10834       // Record the destination address.
10835       stub->set_destination_address(destination
10836                                     | (target_is_thumb ? 1 : 0));
10837     }
10838
10839   // For Cortex-A8, we need to record a relocation at 4K page boundary.
10840   if (this->fix_cortex_a8_
10841       && (r_type == elfcpp::R_ARM_THM_JUMP24
10842           || r_type == elfcpp::R_ARM_THM_JUMP19
10843           || r_type == elfcpp::R_ARM_THM_CALL
10844           || r_type == elfcpp::R_ARM_THM_XPC22)
10845       && (address & 0xfffU) == 0xffeU)
10846     {
10847       // Found a candidate.  Note we haven't checked the destination is
10848       // within 4K here: if we do so (and don't create a record) we can't
10849       // tell that a branch should have been relocated when scanning later.
10850       this->cortex_a8_relocs_info_[address] =
10851         new Cortex_a8_reloc(stub, r_type,
10852                             destination | (target_is_thumb ? 1 : 0));
10853     }
10854 }
10855
10856 // This function scans a relocation sections for stub generation.
10857 // The template parameter Relocate must be a class type which provides
10858 // a single function, relocate(), which implements the machine
10859 // specific part of a relocation.
10860
10861 // BIG_ENDIAN is the endianness of the data.  SH_TYPE is the section type:
10862 // SHT_REL or SHT_RELA.
10863
10864 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
10865 // of relocs.  OUTPUT_SECTION is the output section.
10866 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
10867 // mapped to output offsets.
10868
10869 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
10870 // VIEW_SIZE is the size.  These refer to the input section, unless
10871 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
10872 // the output section.
10873
10874 template<bool big_endian>
10875 template<int sh_type>
10876 void inline
10877 Target_arm<big_endian>::scan_reloc_section_for_stubs(
10878     const Relocate_info<32, big_endian>* relinfo,
10879     const unsigned char* prelocs,
10880     size_t reloc_count,
10881     Output_section* output_section,
10882     bool needs_special_offset_handling,
10883     const unsigned char* view,
10884     elfcpp::Elf_types<32>::Elf_Addr view_address,
10885     section_size_type)
10886 {
10887   typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
10888   const int reloc_size =
10889     Reloc_types<sh_type, 32, big_endian>::reloc_size;
10890
10891   Arm_relobj<big_endian>* arm_object =
10892     Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10893   unsigned int local_count = arm_object->local_symbol_count();
10894
10895   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
10896
10897   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
10898     {
10899       Reltype reloc(prelocs);
10900
10901       typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10902       unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10903       unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10904
10905       r_type = this->get_real_reloc_type(r_type);
10906
10907       // Only a few relocation types need stubs.
10908       if ((r_type != elfcpp::R_ARM_CALL)
10909          && (r_type != elfcpp::R_ARM_JUMP24)
10910          && (r_type != elfcpp::R_ARM_PLT32)
10911          && (r_type != elfcpp::R_ARM_THM_CALL)
10912          && (r_type != elfcpp::R_ARM_THM_XPC22)
10913          && (r_type != elfcpp::R_ARM_THM_JUMP24)
10914          && (r_type != elfcpp::R_ARM_THM_JUMP19)
10915          && (r_type != elfcpp::R_ARM_V4BX))
10916         continue;
10917
10918       section_offset_type offset =
10919         convert_to_section_size_type(reloc.get_r_offset());
10920
10921       if (needs_special_offset_handling)
10922         {
10923           offset = output_section->output_offset(relinfo->object,
10924                                                  relinfo->data_shndx,
10925                                                  offset);
10926           if (offset == -1)
10927             continue;
10928         }
10929
10930       // Create a v4bx stub if --fix-v4bx-interworking is used.
10931       if (r_type == elfcpp::R_ARM_V4BX)
10932         {
10933           if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
10934             {
10935               // Get the BX instruction.
10936               typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
10937               const Valtype* wv =
10938                 reinterpret_cast<const Valtype*>(view + offset);
10939               elfcpp::Elf_types<32>::Elf_Swxword insn =
10940                 elfcpp::Swap<32, big_endian>::readval(wv);
10941               const uint32_t reg = (insn & 0xf);
10942
10943               if (reg < 0xf)
10944                 {
10945                   // Try looking up an existing stub from a stub table.
10946                   Stub_table<big_endian>* stub_table =
10947                     arm_object->stub_table(relinfo->data_shndx);
10948                   gold_assert(stub_table != NULL);
10949
10950                   if (stub_table->find_arm_v4bx_stub(reg) == NULL)
10951                     {
10952                       // create a new stub and add it to stub table.
10953                       Arm_v4bx_stub* stub =
10954                         this->stub_factory().make_arm_v4bx_stub(reg);
10955                       gold_assert(stub != NULL);
10956                       stub_table->add_arm_v4bx_stub(stub);
10957                     }
10958                 }
10959             }
10960           continue;
10961         }
10962
10963       // Get the addend.
10964       Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
10965       elfcpp::Elf_types<32>::Elf_Swxword addend =
10966         stub_addend_reader(r_type, view + offset, reloc);
10967
10968       const Sized_symbol<32>* sym;
10969
10970       Symbol_value<32> symval;
10971       const Symbol_value<32> *psymval;
10972       bool is_defined_in_discarded_section;
10973       unsigned int shndx;
10974       if (r_sym < local_count)
10975         {
10976           sym = NULL;
10977           psymval = arm_object->local_symbol(r_sym);
10978
10979           // If the local symbol belongs to a section we are discarding,
10980           // and that section is a debug section, try to find the
10981           // corresponding kept section and map this symbol to its
10982           // counterpart in the kept section.  The symbol must not 
10983           // correspond to a section we are folding.
10984           bool is_ordinary;
10985           shndx = psymval->input_shndx(&is_ordinary);
10986           is_defined_in_discarded_section =
10987             (is_ordinary
10988              && shndx != elfcpp::SHN_UNDEF
10989              && !arm_object->is_section_included(shndx)
10990              && !relinfo->symtab->is_section_folded(arm_object, shndx));
10991
10992           // We need to compute the would-be final value of this local
10993           // symbol.
10994           if (!is_defined_in_discarded_section)
10995             {
10996               typedef Sized_relobj<32, big_endian> ObjType;
10997               typename ObjType::Compute_final_local_value_status status =
10998                 arm_object->compute_final_local_value(r_sym, psymval, &symval,
10999                                                       relinfo->symtab); 
11000               if (status == ObjType::CFLV_OK)
11001                 {
11002                   // Currently we cannot handle a branch to a target in
11003                   // a merged section.  If this is the case, issue an error
11004                   // and also free the merge symbol value.
11005                   if (!symval.has_output_value())
11006                     {
11007                       const std::string& section_name =
11008                         arm_object->section_name(shndx);
11009                       arm_object->error(_("cannot handle branch to local %u "
11010                                           "in a merged section %s"),
11011                                         r_sym, section_name.c_str());
11012                     }
11013                   psymval = &symval;
11014                 }
11015               else
11016                 {
11017                   // We cannot determine the final value.
11018                   continue;  
11019                 }
11020             }
11021         }
11022       else
11023         {
11024           const Symbol* gsym;
11025           gsym = arm_object->global_symbol(r_sym);
11026           gold_assert(gsym != NULL);
11027           if (gsym->is_forwarder())
11028             gsym = relinfo->symtab->resolve_forwards(gsym);
11029
11030           sym = static_cast<const Sized_symbol<32>*>(gsym);
11031           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11032             symval.set_output_symtab_index(sym->symtab_index());
11033           else
11034             symval.set_no_output_symtab_entry();
11035
11036           // We need to compute the would-be final value of this global
11037           // symbol.
11038           const Symbol_table* symtab = relinfo->symtab;
11039           const Sized_symbol<32>* sized_symbol =
11040             symtab->get_sized_symbol<32>(gsym);
11041           Symbol_table::Compute_final_value_status status;
11042           Arm_address value =
11043             symtab->compute_final_value<32>(sized_symbol, &status);
11044
11045           // Skip this if the symbol has not output section.
11046           if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11047             continue;
11048           symval.set_output_value(value);
11049
11050           if (gsym->type() == elfcpp::STT_TLS)
11051             symval.set_is_tls_symbol();
11052           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11053             symval.set_is_ifunc_symbol();
11054           psymval = &symval;
11055
11056           is_defined_in_discarded_section =
11057             (gsym->is_defined_in_discarded_section()
11058              && gsym->is_undefined());
11059           shndx = 0;
11060         }
11061
11062       Symbol_value<32> symval2;
11063       if (is_defined_in_discarded_section)
11064         {
11065           if (comdat_behavior == CB_UNDETERMINED)
11066             {
11067               std::string name = arm_object->section_name(relinfo->data_shndx);
11068               comdat_behavior = get_comdat_behavior(name.c_str());
11069             }
11070           if (comdat_behavior == CB_PRETEND)
11071             {
11072               // FIXME: This case does not work for global symbols.
11073               // We have no place to store the original section index.
11074               // Fortunately this does not matter for comdat sections,
11075               // only for sections explicitly discarded by a linker
11076               // script.
11077               bool found;
11078               typename elfcpp::Elf_types<32>::Elf_Addr value =
11079                 arm_object->map_to_kept_section(shndx, &found);
11080               if (found)
11081                 symval2.set_output_value(value + psymval->input_value());
11082               else
11083                 symval2.set_output_value(0);
11084             }
11085           else
11086             {
11087               if (comdat_behavior == CB_WARNING)
11088                 gold_warning_at_location(relinfo, i, offset,
11089                                          _("relocation refers to discarded "
11090                                            "section"));
11091               symval2.set_output_value(0);
11092             }
11093           symval2.set_no_output_symtab_entry();
11094           psymval = &symval2;
11095         }
11096
11097       // If symbol is a section symbol, we don't know the actual type of
11098       // destination.  Give up.
11099       if (psymval->is_section_symbol())
11100         continue;
11101
11102       this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11103                                 addend, view_address + offset);
11104     }
11105 }
11106
11107 // Scan an input section for stub generation.
11108
11109 template<bool big_endian>
11110 void
11111 Target_arm<big_endian>::scan_section_for_stubs(
11112     const Relocate_info<32, big_endian>* relinfo,
11113     unsigned int sh_type,
11114     const unsigned char* prelocs,
11115     size_t reloc_count,
11116     Output_section* output_section,
11117     bool needs_special_offset_handling,
11118     const unsigned char* view,
11119     Arm_address view_address,
11120     section_size_type view_size)
11121 {
11122   if (sh_type == elfcpp::SHT_REL)
11123     this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11124         relinfo,
11125         prelocs,
11126         reloc_count,
11127         output_section,
11128         needs_special_offset_handling,
11129         view,
11130         view_address,
11131         view_size);
11132   else if (sh_type == elfcpp::SHT_RELA)
11133     // We do not support RELA type relocations yet.  This is provided for
11134     // completeness.
11135     this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11136         relinfo,
11137         prelocs,
11138         reloc_count,
11139         output_section,
11140         needs_special_offset_handling,
11141         view,
11142         view_address,
11143         view_size);
11144   else
11145     gold_unreachable();
11146 }
11147
11148 // Group input sections for stub generation.
11149 //
11150 // We goup input sections in an output sections so that the total size,
11151 // including any padding space due to alignment is smaller than GROUP_SIZE
11152 // unless the only input section in group is bigger than GROUP_SIZE already.
11153 // Then an ARM stub table is created to follow the last input section
11154 // in group.  For each group an ARM stub table is created an is placed
11155 // after the last group.  If STUB_ALWATS_AFTER_BRANCH is false, we further
11156 // extend the group after the stub table.
11157
11158 template<bool big_endian>
11159 void
11160 Target_arm<big_endian>::group_sections(
11161     Layout* layout,
11162     section_size_type group_size,
11163     bool stubs_always_after_branch)
11164 {
11165   // Group input sections and insert stub table
11166   Layout::Section_list section_list;
11167   layout->get_allocated_sections(&section_list);
11168   for (Layout::Section_list::const_iterator p = section_list.begin();
11169        p != section_list.end();
11170        ++p)
11171     {
11172       Arm_output_section<big_endian>* output_section =
11173         Arm_output_section<big_endian>::as_arm_output_section(*p);
11174       output_section->group_sections(group_size, stubs_always_after_branch,
11175                                      this);
11176     }
11177 }
11178
11179 // Relaxation hook.  This is where we do stub generation.
11180
11181 template<bool big_endian>
11182 bool
11183 Target_arm<big_endian>::do_relax(
11184     int pass,
11185     const Input_objects* input_objects,
11186     Symbol_table* symtab,
11187     Layout* layout)
11188 {
11189   // No need to generate stubs if this is a relocatable link.
11190   gold_assert(!parameters->options().relocatable());
11191
11192   // If this is the first pass, we need to group input sections into
11193   // stub groups.
11194   bool done_exidx_fixup = false;
11195   typedef typename Stub_table_list::iterator Stub_table_iterator;
11196   if (pass == 1)
11197     {
11198       // Determine the stub group size.  The group size is the absolute
11199       // value of the parameter --stub-group-size.  If --stub-group-size
11200       // is passed a negative value, we restict stubs to be always after
11201       // the stubbed branches.
11202       int32_t stub_group_size_param =
11203         parameters->options().stub_group_size();
11204       bool stubs_always_after_branch = stub_group_size_param < 0;
11205       section_size_type stub_group_size = abs(stub_group_size_param);
11206
11207       if (stub_group_size == 1)
11208         {
11209           // Default value.
11210           // Thumb branch range is +-4MB has to be used as the default
11211           // maximum size (a given section can contain both ARM and Thumb
11212           // code, so the worst case has to be taken into account).  If we are
11213           // fixing cortex-a8 errata, the branch range has to be even smaller,
11214           // since wide conditional branch has a range of +-1MB only.
11215           //
11216           // This value is 48K less than that, which allows for 4096
11217           // 12-byte stubs.  If we exceed that, then we will fail to link.
11218           // The user will have to relink with an explicit group size
11219           // option.
11220             stub_group_size = 4145152;
11221         }
11222
11223       // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11224       // page as the first half of a 32-bit branch straddling two 4K pages.
11225       // This is a crude way of enforcing that.  In addition, long conditional
11226       // branches of THUMB-2 have a range of +-1M.  If we are fixing cortex-A8
11227       // erratum, limit the group size to  (1M - 12k) to avoid unreachable
11228       // cortex-A8 stubs from long conditional branches.
11229       if (this->fix_cortex_a8_)
11230         {
11231           stubs_always_after_branch = true;
11232           const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11233           stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11234         }
11235
11236       group_sections(layout, stub_group_size, stubs_always_after_branch);
11237      
11238       // Also fix .ARM.exidx section coverage.
11239       Arm_output_section<big_endian>* exidx_output_section = NULL;
11240       for (Layout::Section_list::const_iterator p =
11241              layout->section_list().begin();
11242            p != layout->section_list().end();
11243            ++p)
11244         if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11245           {
11246             if (exidx_output_section == NULL)
11247               exidx_output_section =
11248                 Arm_output_section<big_endian>::as_arm_output_section(*p);
11249             else
11250               // We cannot handle this now.
11251               gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11252                            "non-relocatable link"),
11253                           exidx_output_section->name(),
11254                           (*p)->name());
11255           }
11256
11257       if (exidx_output_section != NULL)
11258         {
11259           this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11260                                    symtab);
11261           done_exidx_fixup = true;
11262         }
11263     }
11264   else
11265     {
11266       // If this is not the first pass, addresses and file offsets have
11267       // been reset at this point, set them here.
11268       for (Stub_table_iterator sp = this->stub_tables_.begin();
11269            sp != this->stub_tables_.end();
11270            ++sp)
11271         {
11272           Arm_input_section<big_endian>* owner = (*sp)->owner();
11273           off_t off = align_address(owner->original_size(),
11274                                     (*sp)->addralign());
11275           (*sp)->set_address_and_file_offset(owner->address() + off,
11276                                              owner->offset() + off);
11277         }
11278     }
11279
11280   // The Cortex-A8 stubs are sensitive to layout of code sections.  At the
11281   // beginning of each relaxation pass, just blow away all the stubs.
11282   // Alternatively, we could selectively remove only the stubs and reloc
11283   // information for code sections that have moved since the last pass.
11284   // That would require more book-keeping.
11285   if (this->fix_cortex_a8_)
11286     {
11287       // Clear all Cortex-A8 reloc information.
11288       for (typename Cortex_a8_relocs_info::const_iterator p =
11289              this->cortex_a8_relocs_info_.begin();
11290            p != this->cortex_a8_relocs_info_.end();
11291            ++p)
11292         delete p->second;
11293       this->cortex_a8_relocs_info_.clear();
11294
11295       // Remove all Cortex-A8 stubs.
11296       for (Stub_table_iterator sp = this->stub_tables_.begin();
11297            sp != this->stub_tables_.end();
11298            ++sp)
11299         (*sp)->remove_all_cortex_a8_stubs();
11300     }
11301   
11302   // Scan relocs for relocation stubs
11303   for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11304        op != input_objects->relobj_end();
11305        ++op)
11306     {
11307       Arm_relobj<big_endian>* arm_relobj =
11308         Arm_relobj<big_endian>::as_arm_relobj(*op);
11309       arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11310     }
11311
11312   // Check all stub tables to see if any of them have their data sizes
11313   // or addresses alignments changed.  These are the only things that
11314   // matter.
11315   bool any_stub_table_changed = false;
11316   Unordered_set<const Output_section*> sections_needing_adjustment;
11317   for (Stub_table_iterator sp = this->stub_tables_.begin();
11318        (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11319        ++sp)
11320     {
11321       if ((*sp)->update_data_size_and_addralign())
11322         {
11323           // Update data size of stub table owner.
11324           Arm_input_section<big_endian>* owner = (*sp)->owner();
11325           uint64_t address = owner->address();
11326           off_t offset = owner->offset();
11327           owner->reset_address_and_file_offset();
11328           owner->set_address_and_file_offset(address, offset);
11329
11330           sections_needing_adjustment.insert(owner->output_section());
11331           any_stub_table_changed = true;
11332         }
11333     }
11334
11335   // Output_section_data::output_section() returns a const pointer but we
11336   // need to update output sections, so we record all output sections needing
11337   // update above and scan the sections here to find out what sections need
11338   // to be updated.
11339   for(Layout::Section_list::const_iterator p = layout->section_list().begin();
11340       p != layout->section_list().end();
11341       ++p)
11342     {
11343       if (sections_needing_adjustment.find(*p)
11344           != sections_needing_adjustment.end())
11345         (*p)->set_section_offsets_need_adjustment();
11346     }
11347
11348   // Stop relaxation if no EXIDX fix-up and no stub table change.
11349   bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11350
11351   // Finalize the stubs in the last relaxation pass.
11352   if (!continue_relaxation)
11353     {
11354       for (Stub_table_iterator sp = this->stub_tables_.begin();
11355            (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11356             ++sp)
11357         (*sp)->finalize_stubs();
11358
11359       // Update output local symbol counts of objects if necessary.
11360       for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11361            op != input_objects->relobj_end();
11362            ++op)
11363         {
11364           Arm_relobj<big_endian>* arm_relobj =
11365             Arm_relobj<big_endian>::as_arm_relobj(*op);
11366
11367           // Update output local symbol counts.  We need to discard local
11368           // symbols defined in parts of input sections that are discarded by
11369           // relaxation.
11370           if (arm_relobj->output_local_symbol_count_needs_update())
11371             arm_relobj->update_output_local_symbol_count();
11372         }
11373     }
11374
11375   return continue_relaxation;
11376 }
11377
11378 // Relocate a stub.
11379
11380 template<bool big_endian>
11381 void
11382 Target_arm<big_endian>::relocate_stub(
11383     Stub* stub,
11384     const Relocate_info<32, big_endian>* relinfo,
11385     Output_section* output_section,
11386     unsigned char* view,
11387     Arm_address address,
11388     section_size_type view_size)
11389 {
11390   Relocate relocate;
11391   const Stub_template* stub_template = stub->stub_template();
11392   for (size_t i = 0; i < stub_template->reloc_count(); i++)
11393     {
11394       size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11395       const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11396
11397       unsigned int r_type = insn->r_type();
11398       section_size_type reloc_offset = stub_template->reloc_offset(i);
11399       section_size_type reloc_size = insn->size();
11400       gold_assert(reloc_offset + reloc_size <= view_size);
11401
11402       // This is the address of the stub destination.
11403       Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11404       Symbol_value<32> symval;
11405       symval.set_output_value(target);
11406
11407       // Synthesize a fake reloc just in case.  We don't have a symbol so
11408       // we use 0.
11409       unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11410       memset(reloc_buffer, 0, sizeof(reloc_buffer));
11411       elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11412       reloc_write.put_r_offset(reloc_offset);
11413       reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11414       elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11415
11416       relocate.relocate(relinfo, this, output_section,
11417                         this->fake_relnum_for_stubs, rel, r_type,
11418                         NULL, &symval, view + reloc_offset,
11419                         address + reloc_offset, reloc_size);
11420     }
11421 }
11422
11423 // Determine whether an object attribute tag takes an integer, a
11424 // string or both.
11425
11426 template<bool big_endian>
11427 int
11428 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11429 {
11430   if (tag == Object_attribute::Tag_compatibility)
11431     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11432             | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11433   else if (tag == elfcpp::Tag_nodefaults)
11434     return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11435             | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11436   else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11437     return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11438   else if (tag < 32)
11439     return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11440   else
11441     return ((tag & 1) != 0
11442             ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11443             : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11444 }
11445
11446 // Reorder attributes.
11447 //
11448 // The ABI defines that Tag_conformance should be emitted first, and that
11449 // Tag_nodefaults should be second (if either is defined).  This sets those
11450 // two positions, and bumps up the position of all the remaining tags to
11451 // compensate.
11452
11453 template<bool big_endian>
11454 int
11455 Target_arm<big_endian>::do_attributes_order(int num) const
11456 {
11457   // Reorder the known object attributes in output.  We want to move
11458   // Tag_conformance to position 4 and Tag_conformance to position 5
11459   // and shift eveything between 4 .. Tag_conformance - 1 to make room.
11460   if (num == 4)
11461     return elfcpp::Tag_conformance;
11462   if (num == 5)
11463     return elfcpp::Tag_nodefaults;
11464   if ((num - 2) < elfcpp::Tag_nodefaults)
11465     return num - 2;
11466   if ((num - 1) < elfcpp::Tag_conformance)
11467     return num - 1;
11468   return num;
11469 }
11470
11471 // Scan a span of THUMB code for Cortex-A8 erratum.
11472
11473 template<bool big_endian>
11474 void
11475 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11476     Arm_relobj<big_endian>* arm_relobj,
11477     unsigned int shndx,
11478     section_size_type span_start,
11479     section_size_type span_end,
11480     const unsigned char* view,
11481     Arm_address address)
11482 {
11483   // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11484   //
11485   // The opcode is BLX.W, BL.W, B.W, Bcc.W
11486   // The branch target is in the same 4KB region as the
11487   // first half of the branch.
11488   // The instruction before the branch is a 32-bit
11489   // length non-branch instruction.
11490   section_size_type i = span_start;
11491   bool last_was_32bit = false;
11492   bool last_was_branch = false;
11493   while (i < span_end)
11494     {
11495       typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11496       const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11497       uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11498       bool is_blx = false, is_b = false;
11499       bool is_bl = false, is_bcc = false;
11500
11501       bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11502       if (insn_32bit)
11503         {
11504           // Load the rest of the insn (in manual-friendly order).
11505           insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11506
11507           // Encoding T4: B<c>.W.
11508           is_b = (insn & 0xf800d000U) == 0xf0009000U;
11509           // Encoding T1: BL<c>.W.
11510           is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11511           // Encoding T2: BLX<c>.W.
11512           is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11513           // Encoding T3: B<c>.W (not permitted in IT block).
11514           is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11515                     && (insn & 0x07f00000U) != 0x03800000U);
11516         }
11517
11518       bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11519                            
11520       // If this instruction is a 32-bit THUMB branch that crosses a 4K
11521       // page boundary and it follows 32-bit non-branch instruction,
11522       // we need to work around.
11523       if (is_32bit_branch
11524           && ((address + i) & 0xfffU) == 0xffeU
11525           && last_was_32bit
11526           && !last_was_branch)
11527         {
11528           // Check to see if there is a relocation stub for this branch.
11529           bool force_target_arm = false;
11530           bool force_target_thumb = false;
11531           const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11532           Cortex_a8_relocs_info::const_iterator p =
11533             this->cortex_a8_relocs_info_.find(address + i);
11534
11535           if (p != this->cortex_a8_relocs_info_.end())
11536             {
11537               cortex_a8_reloc = p->second;
11538               bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11539
11540               if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11541                   && !target_is_thumb)
11542                 force_target_arm = true;
11543               else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11544                        && target_is_thumb)
11545                 force_target_thumb = true;
11546             }
11547
11548           off_t offset;
11549           Stub_type stub_type = arm_stub_none;
11550
11551           // Check if we have an offending branch instruction.
11552           uint16_t upper_insn = (insn >> 16) & 0xffffU;
11553           uint16_t lower_insn = insn & 0xffffU;
11554           typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11555
11556           if (cortex_a8_reloc != NULL
11557               && cortex_a8_reloc->reloc_stub() != NULL)
11558             // We've already made a stub for this instruction, e.g.
11559             // it's a long branch or a Thumb->ARM stub.  Assume that
11560             // stub will suffice to work around the A8 erratum (see
11561             // setting of always_after_branch above).
11562             ;
11563           else if (is_bcc)
11564             {
11565               offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11566                                                               lower_insn);
11567               stub_type = arm_stub_a8_veneer_b_cond;
11568             }
11569           else if (is_b || is_bl || is_blx)
11570             {
11571               offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11572                                                          lower_insn);
11573               if (is_blx)
11574                 offset &= ~3;
11575
11576               stub_type = (is_blx
11577                            ? arm_stub_a8_veneer_blx
11578                            : (is_bl
11579                               ? arm_stub_a8_veneer_bl
11580                               : arm_stub_a8_veneer_b));
11581             }
11582
11583           if (stub_type != arm_stub_none)
11584             {
11585               Arm_address pc_for_insn = address + i + 4;
11586
11587               // The original instruction is a BL, but the target is
11588               // an ARM instruction.  If we were not making a stub,
11589               // the BL would have been converted to a BLX.  Use the
11590               // BLX stub instead in that case.
11591               if (this->may_use_blx() && force_target_arm
11592                   && stub_type == arm_stub_a8_veneer_bl)
11593                 {
11594                   stub_type = arm_stub_a8_veneer_blx;
11595                   is_blx = true;
11596                   is_bl = false;
11597                 }
11598               // Conversely, if the original instruction was
11599               // BLX but the target is Thumb mode, use the BL stub.
11600               else if (force_target_thumb
11601                        && stub_type == arm_stub_a8_veneer_blx)
11602                 {
11603                   stub_type = arm_stub_a8_veneer_bl;
11604                   is_blx = false;
11605                   is_bl = true;
11606                 }
11607
11608               if (is_blx)
11609                 pc_for_insn &= ~3;
11610
11611               // If we found a relocation, use the proper destination,
11612               // not the offset in the (unrelocated) instruction.
11613               // Note this is always done if we switched the stub type above.
11614               if (cortex_a8_reloc != NULL)
11615                 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11616
11617               Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11618
11619               // Add a new stub if destination address in in the same page.
11620               if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11621                 {
11622                   Cortex_a8_stub* stub =
11623                     this->stub_factory_.make_cortex_a8_stub(stub_type,
11624                                                             arm_relobj, shndx,
11625                                                             address + i,
11626                                                             target, insn);
11627                   Stub_table<big_endian>* stub_table =
11628                     arm_relobj->stub_table(shndx);
11629                   gold_assert(stub_table != NULL);
11630                   stub_table->add_cortex_a8_stub(address + i, stub);
11631                 }
11632             }
11633         }
11634
11635       i += insn_32bit ? 4 : 2;
11636       last_was_32bit = insn_32bit;
11637       last_was_branch = is_32bit_branch;
11638     }
11639 }
11640
11641 // Apply the Cortex-A8 workaround.
11642
11643 template<bool big_endian>
11644 void
11645 Target_arm<big_endian>::apply_cortex_a8_workaround(
11646     const Cortex_a8_stub* stub,
11647     Arm_address stub_address,
11648     unsigned char* insn_view,
11649     Arm_address insn_address)
11650 {
11651   typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11652   Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11653   Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11654   Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11655   off_t branch_offset = stub_address - (insn_address + 4);
11656
11657   typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11658   switch (stub->stub_template()->type())
11659     {
11660     case arm_stub_a8_veneer_b_cond:
11661       // For a conditional branch, we re-write it to be a uncondition
11662       // branch to the stub.  We use the THUMB-2 encoding here.
11663       upper_insn = 0xf000U;
11664       lower_insn = 0xb800U;
11665       // Fall through
11666     case arm_stub_a8_veneer_b:
11667     case arm_stub_a8_veneer_bl:
11668     case arm_stub_a8_veneer_blx:
11669       if ((lower_insn & 0x5000U) == 0x4000U)
11670         // For a BLX instruction, make sure that the relocation is
11671         // rounded up to a word boundary.  This follows the semantics of
11672         // the instruction which specifies that bit 1 of the target
11673         // address will come from bit 1 of the base address.
11674         branch_offset = (branch_offset + 2) & ~3;
11675
11676       // Put BRANCH_OFFSET back into the insn.
11677       gold_assert(!utils::has_overflow<25>(branch_offset));
11678       upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11679       lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11680       break;
11681
11682     default:
11683       gold_unreachable();
11684     }
11685
11686   // Put the relocated value back in the object file:
11687   elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11688   elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11689 }
11690
11691 template<bool big_endian>
11692 class Target_selector_arm : public Target_selector
11693 {
11694  public:
11695   Target_selector_arm()
11696     : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11697                       (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
11698   { }
11699
11700   Target*
11701   do_instantiate_target()
11702   { return new Target_arm<big_endian>(); }
11703 };
11704
11705 // Fix .ARM.exidx section coverage.
11706
11707 template<bool big_endian>
11708 void
11709 Target_arm<big_endian>::fix_exidx_coverage(
11710     Layout* layout,
11711     const Input_objects* input_objects,
11712     Arm_output_section<big_endian>* exidx_section,
11713     Symbol_table* symtab)
11714 {
11715   // We need to look at all the input sections in output in ascending
11716   // order of of output address.  We do that by building a sorted list
11717   // of output sections by addresses.  Then we looks at the output sections
11718   // in order.  The input sections in an output section are already sorted
11719   // by addresses within the output section.
11720
11721   typedef std::set<Output_section*, output_section_address_less_than>
11722       Sorted_output_section_list;
11723   Sorted_output_section_list sorted_output_sections;
11724
11725   // Find out all the output sections of input sections pointed by
11726   // EXIDX input sections.
11727   for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11728        p != input_objects->relobj_end();
11729        ++p)
11730     {
11731       Arm_relobj<big_endian>* arm_relobj =
11732         Arm_relobj<big_endian>::as_arm_relobj(*p);
11733       std::vector<unsigned int> shndx_list;
11734       arm_relobj->get_exidx_shndx_list(&shndx_list);
11735       for (size_t i = 0; i < shndx_list.size(); ++i)
11736         {
11737           const Arm_exidx_input_section* exidx_input_section =
11738             arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
11739           gold_assert(exidx_input_section != NULL);
11740           if (!exidx_input_section->has_errors())
11741             {
11742               unsigned int text_shndx = exidx_input_section->link();
11743               Output_section* os = arm_relobj->output_section(text_shndx);
11744               if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
11745                 sorted_output_sections.insert(os);
11746             }
11747         }
11748     }
11749
11750   // Go over the output sections in ascending order of output addresses.
11751   typedef typename Arm_output_section<big_endian>::Text_section_list
11752       Text_section_list;
11753   Text_section_list sorted_text_sections;
11754   for(typename Sorted_output_section_list::iterator p =
11755         sorted_output_sections.begin();
11756       p != sorted_output_sections.end();
11757       ++p)
11758     {
11759       Arm_output_section<big_endian>* arm_output_section =
11760         Arm_output_section<big_endian>::as_arm_output_section(*p);
11761       arm_output_section->append_text_sections_to_list(&sorted_text_sections);
11762     } 
11763
11764   exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
11765                                     merge_exidx_entries());
11766 }
11767
11768 Target_selector_arm<false> target_selector_arm;
11769 Target_selector_arm<true> target_selector_armbe;
11770
11771 } // End anonymous namespace.