Merge branch 'vendor/GCC44'
[dragonfly.git] / contrib / binutils-2.22 / gold / target-reloc.h
1 // target-reloc.h -- target specific relocation support  -*- C++ -*-
2
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #ifndef GOLD_TARGET_RELOC_H
24 #define GOLD_TARGET_RELOC_H
25
26 #include "elfcpp.h"
27 #include "symtab.h"
28 #include "object.h"
29 #include "reloc.h"
30 #include "reloc-types.h"
31
32 namespace gold
33 {
34
35 // This function implements the generic part of reloc scanning.  The
36 // template parameter Scan must be a class type which provides two
37 // functions: local() and global().  Those functions implement the
38 // machine specific part of scanning.  We do it this way to
39 // avoid making a function call for each relocation, and to avoid
40 // repeating the generic code for each target.
41
42 template<int size, bool big_endian, typename Target_type, int sh_type,
43          typename Scan>
44 inline void
45 scan_relocs(
46     Symbol_table* symtab,
47     Layout* layout,
48     Target_type* target,
49     Sized_relobj_file<size, big_endian>* object,
50     unsigned int data_shndx,
51     const unsigned char* prelocs,
52     size_t reloc_count,
53     Output_section* output_section,
54     bool needs_special_offset_handling,
55     size_t local_count,
56     const unsigned char* plocal_syms)
57 {
58   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
59   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
60   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
61   Scan scan;
62
63   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
64     {
65       Reltype reloc(prelocs);
66
67       if (needs_special_offset_handling
68           && !output_section->is_input_address_mapped(object, data_shndx,
69                                                       reloc.get_r_offset()))
70         continue;
71
72       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
73       unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
74       unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
75
76       if (r_sym < local_count)
77         {
78           gold_assert(plocal_syms != NULL);
79           typename elfcpp::Sym<size, big_endian> lsym(plocal_syms
80                                                       + r_sym * sym_size);
81           unsigned int shndx = lsym.get_st_shndx();
82           bool is_ordinary;
83           shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
84           if (is_ordinary
85               && shndx != elfcpp::SHN_UNDEF
86               && !object->is_section_included(shndx)
87               && !symtab->is_section_folded(object, shndx))
88             {
89               // RELOC is a relocation against a local symbol in a
90               // section we are discarding.  We can ignore this
91               // relocation.  It will eventually become a reloc
92               // against the value zero.
93               //
94               // FIXME: We should issue a warning if this is an
95               // allocated section; is this the best place to do it?
96               // 
97               // FIXME: The old GNU linker would in some cases look
98               // for the linkonce section which caused this section to
99               // be discarded, and, if the other section was the same
100               // size, change the reloc to refer to the other section.
101               // That seems risky and weird to me, and I don't know of
102               // any case where it is actually required.
103
104               continue;
105             }
106           scan.local(symtab, layout, target, object, data_shndx,
107                      output_section, reloc, r_type, lsym);
108         }
109       else
110         {
111           Symbol* gsym = object->global_symbol(r_sym);
112           gold_assert(gsym != NULL);
113           if (gsym->is_forwarder())
114             gsym = symtab->resolve_forwards(gsym);
115
116           scan.global(symtab, layout, target, object, data_shndx,
117                       output_section, reloc, r_type, gsym);
118         }
119     }
120 }
121
122 // Behavior for relocations to discarded comdat sections.
123
124 enum Comdat_behavior
125 {
126   CB_UNDETERMINED,   // Not yet determined -- need to look at section name.
127   CB_PRETEND,        // Attempt to map to the corresponding kept section.
128   CB_IGNORE,         // Ignore the relocation.
129   CB_WARNING         // Print a warning.
130 };
131
132 // Decide what the linker should do for relocations that refer to discarded
133 // comdat sections.  This decision is based on the name of the section being
134 // relocated.
135
136 inline Comdat_behavior
137 get_comdat_behavior(const char* name)
138 {
139   if (Layout::is_debug_info_section(name))
140     return CB_PRETEND;
141   if (strcmp(name, ".eh_frame") == 0
142       || strcmp(name, ".gcc_except_table") == 0)
143     return CB_IGNORE;
144   return CB_WARNING;
145 }
146
147 // Give an error for a symbol with non-default visibility which is not
148 // defined locally.
149
150 inline void
151 visibility_error(const Symbol* sym)
152 {
153   const char* v;
154   switch (sym->visibility())
155     {
156     case elfcpp::STV_INTERNAL:
157       v = _("internal");
158       break;
159     case elfcpp::STV_HIDDEN:
160       v = _("hidden");
161       break;
162     case elfcpp::STV_PROTECTED:
163       v = _("protected");
164       break;
165     default:
166       gold_unreachable();
167     }
168   gold_error(_("%s symbol '%s' is not defined locally"),
169              v, sym->name());
170 }
171
172 // Return true if we are should issue an error saying that SYM is an
173 // undefined symbol.  This is called if there is a relocation against
174 // SYM.
175
176 inline bool
177 issue_undefined_symbol_error(const Symbol* sym)
178 {
179   // We only report global symbols.
180   if (sym == NULL)
181     return false;
182
183   // We only report undefined symbols.
184   if (!sym->is_undefined() && !sym->is_placeholder())
185     return false;
186
187   // We don't report weak symbols.
188   if (sym->binding() == elfcpp::STB_WEAK)
189     return false;
190
191   // We don't report symbols defined in discarded sections.
192   if (sym->is_defined_in_discarded_section())
193     return false;
194
195   // If the target defines this symbol, don't report it here.
196   if (parameters->target().is_defined_by_abi(sym))
197     return false;
198
199   // See if we've been told to ignore whether this symbol is
200   // undefined.
201   const char* const u = parameters->options().unresolved_symbols();
202   if (u != NULL)
203     {
204       if (strcmp(u, "ignore-all") == 0)
205         return false;
206       if (strcmp(u, "report-all") == 0)
207         return true;
208       if (strcmp(u, "ignore-in-object-files") == 0 && !sym->in_dyn())
209         return false;
210       if (strcmp(u, "ignore-in-shared-libs") == 0 && !sym->in_reg())
211         return false;
212     }
213
214   // When creating a shared library, only report unresolved symbols if
215   // -z defs was used.
216   if (parameters->options().shared() && !parameters->options().defs())
217     return false;
218
219   // Otherwise issue a warning.
220   return true;
221 }
222
223 // This function implements the generic part of relocation processing.
224 // The template parameter Relocate must be a class type which provides
225 // a single function, relocate(), which implements the machine
226 // specific part of a relocation.
227
228 // SIZE is the ELF size: 32 or 64.  BIG_ENDIAN is the endianness of
229 // the data.  SH_TYPE is the section type: SHT_REL or SHT_RELA.
230 // RELOCATE implements operator() to do a relocation.
231
232 // PRELOCS points to the relocation data.  RELOC_COUNT is the number
233 // of relocs.  OUTPUT_SECTION is the output section.
234 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
235 // mapped to output offsets.
236
237 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
238 // VIEW_SIZE is the size.  These refer to the input section, unless
239 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
240 // the output section.
241
242 // RELOC_SYMBOL_CHANGES is used for -fsplit-stack support.  If it is
243 // not NULL, it is a vector indexed by relocation index.  If that
244 // entry is not NULL, it points to a global symbol which used as the
245 // symbol for the relocation, ignoring the symbol index in the
246 // relocation.
247
248 template<int size, bool big_endian, typename Target_type, int sh_type,
249          typename Relocate>
250 inline void
251 relocate_section(
252     const Relocate_info<size, big_endian>* relinfo,
253     Target_type* target,
254     const unsigned char* prelocs,
255     size_t reloc_count,
256     Output_section* output_section,
257     bool needs_special_offset_handling,
258     unsigned char* view,
259     typename elfcpp::Elf_types<size>::Elf_Addr view_address,
260     section_size_type view_size,
261     const Reloc_symbol_changes* reloc_symbol_changes)
262 {
263   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
264   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
265   Relocate relocate;
266
267   Sized_relobj_file<size, big_endian>* object = relinfo->object;
268   unsigned int local_count = object->local_symbol_count();
269
270   Comdat_behavior comdat_behavior = CB_UNDETERMINED;
271
272   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
273     {
274       Reltype reloc(prelocs);
275
276       section_offset_type offset =
277         convert_to_section_size_type(reloc.get_r_offset());
278
279       if (needs_special_offset_handling)
280         {
281           offset = output_section->output_offset(relinfo->object,
282                                                  relinfo->data_shndx,
283                                                  offset);
284           if (offset == -1)
285             continue;
286         }
287
288       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
289       unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
290       unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
291
292       const Sized_symbol<size>* sym;
293
294       Symbol_value<size> symval;
295       const Symbol_value<size> *psymval;
296       bool is_defined_in_discarded_section;
297       unsigned int shndx;
298       if (r_sym < local_count
299           && (reloc_symbol_changes == NULL
300               || (*reloc_symbol_changes)[i] == NULL))
301         {
302           sym = NULL;
303           psymval = object->local_symbol(r_sym);
304
305           // If the local symbol belongs to a section we are discarding,
306           // and that section is a debug section, try to find the
307           // corresponding kept section and map this symbol to its
308           // counterpart in the kept section.  The symbol must not 
309           // correspond to a section we are folding.
310           bool is_ordinary;
311           shndx = psymval->input_shndx(&is_ordinary);
312           is_defined_in_discarded_section =
313             (is_ordinary
314              && shndx != elfcpp::SHN_UNDEF
315              && !object->is_section_included(shndx)
316              && !relinfo->symtab->is_section_folded(object, shndx));
317         }
318       else
319         {
320           const Symbol* gsym;
321           if (reloc_symbol_changes != NULL
322               && (*reloc_symbol_changes)[i] != NULL)
323             gsym = (*reloc_symbol_changes)[i];
324           else
325             {
326               gsym = object->global_symbol(r_sym);
327               gold_assert(gsym != NULL);
328               if (gsym->is_forwarder())
329                 gsym = relinfo->symtab->resolve_forwards(gsym);
330             }
331
332           sym = static_cast<const Sized_symbol<size>*>(gsym);
333           if (sym->has_symtab_index() && sym->symtab_index() != -1U)
334             symval.set_output_symtab_index(sym->symtab_index());
335           else
336             symval.set_no_output_symtab_entry();
337           symval.set_output_value(sym->value());
338           if (gsym->type() == elfcpp::STT_TLS)
339             symval.set_is_tls_symbol();
340           else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
341             symval.set_is_ifunc_symbol();
342           psymval = &symval;
343
344           is_defined_in_discarded_section =
345             (gsym->is_defined_in_discarded_section()
346              && gsym->is_undefined());
347           shndx = 0;
348         }
349
350       Symbol_value<size> symval2;
351       if (is_defined_in_discarded_section)
352         {
353           if (comdat_behavior == CB_UNDETERMINED)
354             {
355               std::string name = object->section_name(relinfo->data_shndx);
356               comdat_behavior = get_comdat_behavior(name.c_str());
357             }
358           if (comdat_behavior == CB_PRETEND)
359             {
360               // FIXME: This case does not work for global symbols.
361               // We have no place to store the original section index.
362               // Fortunately this does not matter for comdat sections,
363               // only for sections explicitly discarded by a linker
364               // script.
365               bool found;
366               typename elfcpp::Elf_types<size>::Elf_Addr value =
367                 object->map_to_kept_section(shndx, &found);
368               if (found)
369                 symval2.set_output_value(value + psymval->input_value());
370               else
371                 symval2.set_output_value(0);
372             }
373           else
374             {
375               if (comdat_behavior == CB_WARNING)
376                 gold_warning_at_location(relinfo, i, offset,
377                                          _("relocation refers to discarded "
378                                            "section"));
379               symval2.set_output_value(0);
380             }
381           symval2.set_no_output_symtab_entry();
382           psymval = &symval2;
383         }
384
385       if (!relocate.relocate(relinfo, target, output_section, i, reloc,
386                              r_type, sym, psymval, view + offset,
387                              view_address + offset, view_size))
388         continue;
389
390       if (offset < 0 || static_cast<section_size_type>(offset) >= view_size)
391         {
392           gold_error_at_location(relinfo, i, offset,
393                                  _("reloc has bad offset %zu"),
394                                  static_cast<size_t>(offset));
395           continue;
396         }
397
398       if (issue_undefined_symbol_error(sym))
399         gold_undefined_symbol_at_location(sym, relinfo, i, offset);
400       else if (sym != NULL
401                && sym->visibility() != elfcpp::STV_DEFAULT
402                && (sym->is_undefined() || sym->is_from_dynobj()))
403         visibility_error(sym);
404
405       if (sym != NULL && sym->has_warning())
406         relinfo->symtab->issue_warning(sym, relinfo, i, offset);
407     }
408 }
409
410 // Apply an incremental relocation.
411
412 template<int size, bool big_endian, typename Target_type,
413          typename Relocate>
414 void
415 apply_relocation(const Relocate_info<size, big_endian>* relinfo,
416                  Target_type* target,
417                  typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
418                  unsigned int r_type,
419                  typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
420                  const Symbol* gsym,
421                  unsigned char* view,
422                  typename elfcpp::Elf_types<size>::Elf_Addr address,
423                  section_size_type view_size)
424 {
425   // Construct the ELF relocation in a temporary buffer.
426   const int reloc_size = elfcpp::Elf_sizes<64>::rela_size;
427   unsigned char relbuf[reloc_size];
428   elfcpp::Rela<64, false> rel(relbuf);
429   elfcpp::Rela_write<64, false> orel(relbuf);
430   orel.put_r_offset(r_offset);
431   orel.put_r_info(elfcpp::elf_r_info<64>(0, r_type));
432   orel.put_r_addend(r_addend);
433
434   // Setup a Symbol_value for the global symbol.
435   const Sized_symbol<64>* sym = static_cast<const Sized_symbol<64>*>(gsym);
436   Symbol_value<64> symval;
437   gold_assert(sym->has_symtab_index() && sym->symtab_index() != -1U);
438   symval.set_output_symtab_index(sym->symtab_index());
439   symval.set_output_value(sym->value());
440   if (gsym->type() == elfcpp::STT_TLS)
441     symval.set_is_tls_symbol();
442   else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
443     symval.set_is_ifunc_symbol();
444
445   Relocate relocate;
446   relocate.relocate(relinfo, target, NULL, -1U, rel, r_type, sym, &symval,
447                     view + r_offset, address + r_offset, view_size);
448 }
449
450 // This class may be used as a typical class for the
451 // Scan_relocatable_reloc parameter to scan_relocatable_relocs.  The
452 // template parameter Classify_reloc must be a class type which
453 // provides a function get_size_for_reloc which returns the number of
454 // bytes to which a reloc applies.  This class is intended to capture
455 // the most typical target behaviour, while still permitting targets
456 // to define their own independent class for Scan_relocatable_reloc.
457
458 template<int sh_type, typename Classify_reloc>
459 class Default_scan_relocatable_relocs
460 {
461  public:
462   // Return the strategy to use for a local symbol which is not a
463   // section symbol, given the relocation type.
464   inline Relocatable_relocs::Reloc_strategy
465   local_non_section_strategy(unsigned int r_type, Relobj*, unsigned int r_sym)
466   {
467     // We assume that relocation type 0 is NONE.  Targets which are
468     // different must override.
469     if (r_type == 0 && r_sym == 0)
470       return Relocatable_relocs::RELOC_DISCARD;
471     return Relocatable_relocs::RELOC_COPY;
472   }
473
474   // Return the strategy to use for a local symbol which is a section
475   // symbol, given the relocation type.
476   inline Relocatable_relocs::Reloc_strategy
477   local_section_strategy(unsigned int r_type, Relobj* object)
478   {
479     if (sh_type == elfcpp::SHT_RELA)
480       return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
481     else
482       {
483         Classify_reloc classify;
484         switch (classify.get_size_for_reloc(r_type, object))
485           {
486           case 0:
487             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
488           case 1:
489             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_1;
490           case 2:
491             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_2;
492           case 4:
493             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4;
494           case 8:
495             return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_8;
496           default:
497             gold_unreachable();
498           }
499       }
500   }
501
502   // Return the strategy to use for a global symbol, given the
503   // relocation type, the object, and the symbol index.
504   inline Relocatable_relocs::Reloc_strategy
505   global_strategy(unsigned int, Relobj*, unsigned int)
506   { return Relocatable_relocs::RELOC_COPY; }
507 };
508
509 // Scan relocs during a relocatable link.  This is a default
510 // definition which should work for most targets.
511 // Scan_relocatable_reloc must name a class type which provides three
512 // functions which return a Relocatable_relocs::Reloc_strategy code:
513 // global_strategy, local_non_section_strategy, and
514 // local_section_strategy.  Most targets should be able to use
515 // Default_scan_relocatable_relocs as this class.
516
517 template<int size, bool big_endian, int sh_type,
518          typename Scan_relocatable_reloc>
519 void
520 scan_relocatable_relocs(
521     Symbol_table*,
522     Layout*,
523     Sized_relobj_file<size, big_endian>* object,
524     unsigned int data_shndx,
525     const unsigned char* prelocs,
526     size_t reloc_count,
527     Output_section* output_section,
528     bool needs_special_offset_handling,
529     size_t local_symbol_count,
530     const unsigned char* plocal_syms,
531     Relocatable_relocs* rr)
532 {
533   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
534   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
535   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
536   Scan_relocatable_reloc scan;
537
538   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
539     {
540       Reltype reloc(prelocs);
541
542       Relocatable_relocs::Reloc_strategy strategy;
543
544       if (needs_special_offset_handling
545           && !output_section->is_input_address_mapped(object, data_shndx,
546                                                       reloc.get_r_offset()))
547         strategy = Relocatable_relocs::RELOC_DISCARD;
548       else
549         {
550           typename elfcpp::Elf_types<size>::Elf_WXword r_info =
551             reloc.get_r_info();
552           const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
553           const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
554
555           if (r_sym >= local_symbol_count)
556             strategy = scan.global_strategy(r_type, object, r_sym);
557           else
558             {
559               gold_assert(plocal_syms != NULL);
560               typename elfcpp::Sym<size, big_endian> lsym(plocal_syms
561                                                           + r_sym * sym_size);
562               unsigned int shndx = lsym.get_st_shndx();
563               bool is_ordinary;
564               shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
565               if (is_ordinary
566                   && shndx != elfcpp::SHN_UNDEF
567                   && !object->is_section_included(shndx))
568                 {
569                   // RELOC is a relocation against a local symbol
570                   // defined in a section we are discarding.  Discard
571                   // the reloc.  FIXME: Should we issue a warning?
572                   strategy = Relocatable_relocs::RELOC_DISCARD;
573                 }
574               else if (lsym.get_st_type() != elfcpp::STT_SECTION)
575                 strategy = scan.local_non_section_strategy(r_type, object,
576                                                            r_sym);
577               else
578                 {
579                   strategy = scan.local_section_strategy(r_type, object);
580                   if (strategy != Relocatable_relocs::RELOC_DISCARD)
581                     object->output_section(shndx)->set_needs_symtab_index();
582                 }
583
584               if (strategy == Relocatable_relocs::RELOC_COPY)
585                 object->set_must_have_output_symtab_entry(r_sym);
586             }
587         }
588
589       rr->set_next_reloc_strategy(strategy);
590     }
591 }
592
593 // Relocate relocs during a relocatable link.  This is a default
594 // definition which should work for most targets.
595
596 template<int size, bool big_endian, int sh_type>
597 void
598 relocate_for_relocatable(
599     const Relocate_info<size, big_endian>* relinfo,
600     const unsigned char* prelocs,
601     size_t reloc_count,
602     Output_section* output_section,
603     typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
604     const Relocatable_relocs* rr,
605     unsigned char* view,
606     typename elfcpp::Elf_types<size>::Elf_Addr view_address,
607     section_size_type view_size,
608     unsigned char* reloc_view,
609     section_size_type reloc_view_size)
610 {
611   typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
612   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
613   typedef typename Reloc_types<sh_type, size, big_endian>::Reloc_write
614     Reltype_write;
615   const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
616   const Address invalid_address = static_cast<Address>(0) - 1;
617
618   Sized_relobj_file<size, big_endian>* const object = relinfo->object;
619   const unsigned int local_count = object->local_symbol_count();
620
621   unsigned char* pwrite = reloc_view;
622
623   for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
624     {
625       Relocatable_relocs::Reloc_strategy strategy = rr->strategy(i);
626       if (strategy == Relocatable_relocs::RELOC_DISCARD)
627         continue;
628
629       if (strategy == Relocatable_relocs::RELOC_SPECIAL)
630         {
631           // Target wants to handle this relocation.
632           Sized_target<size, big_endian>* target =
633             parameters->sized_target<size, big_endian>();
634           target->relocate_special_relocatable(relinfo, sh_type, prelocs,
635                                                i, output_section,
636                                                offset_in_output_section,
637                                                view, view_address,
638                                                view_size, pwrite);
639           pwrite += reloc_size;
640           continue;
641         }
642       Reltype reloc(prelocs);
643       Reltype_write reloc_write(pwrite);
644
645       typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
646       const unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
647       const unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
648
649       // Get the new symbol index.
650
651       unsigned int new_symndx;
652       if (r_sym < local_count)
653         {
654           switch (strategy)
655             {
656             case Relocatable_relocs::RELOC_COPY:
657               if (r_sym == 0)
658                 new_symndx = 0;
659               else
660                 {
661                   new_symndx = object->symtab_index(r_sym);
662                   gold_assert(new_symndx != -1U);
663                 }
664               break;
665
666             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA:
667             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0:
668             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_1:
669             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_2:
670             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4:
671             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_8:
672             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED:
673               {
674                 // We are adjusting a section symbol.  We need to find
675                 // the symbol table index of the section symbol for
676                 // the output section corresponding to input section
677                 // in which this symbol is defined.
678                 gold_assert(r_sym < local_count);
679                 bool is_ordinary;
680                 unsigned int shndx =
681                   object->local_symbol_input_shndx(r_sym, &is_ordinary);
682                 gold_assert(is_ordinary);
683                 Output_section* os = object->output_section(shndx);
684                 gold_assert(os != NULL);
685                 gold_assert(os->needs_symtab_index());
686                 new_symndx = os->symtab_index();
687               }
688               break;
689
690             default:
691               gold_unreachable();
692             }
693         }
694       else
695         {
696           const Symbol* gsym = object->global_symbol(r_sym);
697           gold_assert(gsym != NULL);
698           if (gsym->is_forwarder())
699             gsym = relinfo->symtab->resolve_forwards(gsym);
700
701           gold_assert(gsym->has_symtab_index());
702           new_symndx = gsym->symtab_index();
703         }
704
705       // Get the new offset--the location in the output section where
706       // this relocation should be applied.
707
708       Address offset = reloc.get_r_offset();
709       Address new_offset;
710       if (offset_in_output_section != invalid_address)
711         new_offset = offset + offset_in_output_section;
712       else
713         {
714           section_offset_type sot_offset =
715               convert_types<section_offset_type, Address>(offset);
716           section_offset_type new_sot_offset =
717               output_section->output_offset(object, relinfo->data_shndx,
718                                             sot_offset);
719           gold_assert(new_sot_offset != -1);
720           new_offset = new_sot_offset;
721         }
722
723       // In an object file, r_offset is an offset within the section.
724       // In an executable or dynamic object, generated by
725       // --emit-relocs, r_offset is an absolute address.
726       if (!parameters->options().relocatable())
727         {
728           new_offset += view_address;
729           if (offset_in_output_section != invalid_address)
730             new_offset -= offset_in_output_section;
731         }
732
733       reloc_write.put_r_offset(new_offset);
734       reloc_write.put_r_info(elfcpp::elf_r_info<size>(new_symndx, r_type));
735
736       // Handle the reloc addend based on the strategy.
737
738       if (strategy == Relocatable_relocs::RELOC_COPY)
739         {
740           if (sh_type == elfcpp::SHT_RELA)
741             Reloc_types<sh_type, size, big_endian>::
742               copy_reloc_addend(&reloc_write,
743                                 &reloc);
744         }
745       else
746         {
747           // The relocation uses a section symbol in the input file.
748           // We are adjusting it to use a section symbol in the output
749           // file.  The input section symbol refers to some address in
750           // the input section.  We need the relocation in the output
751           // file to refer to that same address.  This adjustment to
752           // the addend is the same calculation we use for a simple
753           // absolute relocation for the input section symbol.
754
755           const Symbol_value<size>* psymval = object->local_symbol(r_sym);
756
757           unsigned char* padd = view + offset;
758           switch (strategy)
759             {
760             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA:
761               {
762                 typename elfcpp::Elf_types<size>::Elf_Swxword addend;
763                 addend = Reloc_types<sh_type, size, big_endian>::
764                            get_reloc_addend(&reloc);
765                 addend = psymval->value(object, addend);
766                 Reloc_types<sh_type, size, big_endian>::
767                   set_reloc_addend(&reloc_write, addend);
768               }
769               break;
770
771             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0:
772               break;
773
774             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_1:
775               Relocate_functions<size, big_endian>::rel8(padd, object,
776                                                          psymval);
777               break;
778
779             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_2:
780               Relocate_functions<size, big_endian>::rel16(padd, object,
781                                                           psymval);
782               break;
783
784             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4:
785               Relocate_functions<size, big_endian>::rel32(padd, object,
786                                                           psymval);
787               break;
788
789             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_8:
790               Relocate_functions<size, big_endian>::rel64(padd, object,
791                                                           psymval);
792               break;
793
794             case Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED:
795               Relocate_functions<size, big_endian>::rel32_unaligned(padd,
796                                                                     object,
797                                                                     psymval);
798               break;
799
800             default:
801               gold_unreachable();
802             }
803         }
804
805       pwrite += reloc_size;
806     }
807
808   gold_assert(static_cast<section_size_type>(pwrite - reloc_view)
809               == reloc_view_size);
810 }
811
812 } // End namespace gold.
813
814 #endif // !defined(GOLD_TARGET_RELOC_H)