1 // reloc.cc -- relocate input files for gold.
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
27 #include "workqueue.h"
32 #include "target-reloc.h"
38 // Read_relocs methods.
40 // These tasks just read the relocation information from the file.
41 // After reading it, the start another task to process the
42 // information. These tasks requires access to the file.
45 Read_relocs::is_runnable()
47 return this->object_->is_locked() ? this->object_->token() : NULL;
53 Read_relocs::locks(Task_locker* tl)
55 tl->add(this, this->object_->token());
58 // Read the relocations and then start a Scan_relocs_task.
61 Read_relocs::run(Workqueue* workqueue)
63 Read_relocs_data *rd = new Read_relocs_data;
64 this->object_->read_relocs(rd);
65 this->object_->set_relocs_data(rd);
66 this->object_->release();
68 // If garbage collection or identical comdat folding is desired, we
69 // process the relocs first before scanning them. Scanning of relocs is
70 // done only after garbage or identical sections is identified.
71 if (parameters->options().gc_sections() || parameters->options().icf())
73 workqueue->queue_next(new Gc_process_relocs(this->options_,
82 workqueue->queue_next(new Scan_relocs(this->options_, this->symtab_,
83 this->layout_, this->object_, rd,
89 // Return a debugging name for the task.
92 Read_relocs::get_name() const
94 return "Read_relocs " + this->object_->name();
97 // Gc_process_relocs methods.
99 // These tasks process the relocations read by Read_relocs and
100 // determine which sections are referenced and which are garbage.
101 // This task is done only when --gc-sections is used.
104 Gc_process_relocs::is_runnable()
106 if (this->object_->is_locked())
107 return this->object_->token();
112 Gc_process_relocs::locks(Task_locker* tl)
114 tl->add(this, this->object_->token());
115 tl->add(this, this->blocker_);
119 Gc_process_relocs::run(Workqueue*)
121 this->object_->gc_process_relocs(this->options_, this->symtab_, this->layout_,
123 this->object_->release();
126 // Return a debugging name for the task.
129 Gc_process_relocs::get_name() const
131 return "Gc_process_relocs " + this->object_->name();
134 // Scan_relocs methods.
136 // These tasks scan the relocations read by Read_relocs and mark up
137 // the symbol table to indicate which relocations are required. We
138 // use a lock on the symbol table to keep them from interfering with
142 Scan_relocs::is_runnable()
144 if (!this->symtab_lock_->is_writable())
145 return this->symtab_lock_;
146 if (this->object_->is_locked())
147 return this->object_->token();
151 // Return the locks we hold: one on the file, one on the symbol table
155 Scan_relocs::locks(Task_locker* tl)
157 tl->add(this, this->object_->token());
158 tl->add(this, this->symtab_lock_);
159 tl->add(this, this->blocker_);
165 Scan_relocs::run(Workqueue*)
167 this->object_->scan_relocs(this->options_, this->symtab_, this->layout_,
169 this->object_->release();
174 // Return a debugging name for the task.
177 Scan_relocs::get_name() const
179 return "Scan_relocs " + this->object_->name();
182 // Relocate_task methods.
184 // We may have to wait for the output sections to be written.
187 Relocate_task::is_runnable()
189 if (this->object_->relocs_must_follow_section_writes()
190 && this->output_sections_blocker_->is_blocked())
191 return this->output_sections_blocker_;
193 if (this->object_->is_locked())
194 return this->object_->token();
199 // We want to lock the file while we run. We want to unblock
200 // INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done.
201 // INPUT_SECTIONS_BLOCKER may be NULL.
204 Relocate_task::locks(Task_locker* tl)
206 if (this->input_sections_blocker_ != NULL)
207 tl->add(this, this->input_sections_blocker_);
208 tl->add(this, this->final_blocker_);
209 tl->add(this, this->object_->token());
215 Relocate_task::run(Workqueue*)
217 this->object_->relocate(this->options_, this->symtab_, this->layout_,
220 // This is normally the last thing we will do with an object, so
221 // uncache all views.
222 this->object_->clear_view_cache_marks();
224 this->object_->release();
227 // Return a debugging name for the task.
230 Relocate_task::get_name() const
232 return "Relocate_task " + this->object_->name();
235 // Read the relocs and local symbols from the object file and store
236 // the information in RD.
238 template<int size, bool big_endian>
240 Sized_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd)
244 unsigned int shnum = this->shnum();
248 rd->relocs.reserve(shnum / 2);
250 const Output_sections& out_sections(this->output_sections());
251 const std::vector<Address>& out_offsets(this->section_offsets_);
253 const unsigned char *pshdrs = this->get_view(this->elf_file_.shoff(),
254 shnum * This::shdr_size,
256 // Skip the first, dummy, section.
257 const unsigned char *ps = pshdrs + This::shdr_size;
258 for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size)
260 typename This::Shdr shdr(ps);
262 unsigned int sh_type = shdr.get_sh_type();
263 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
266 unsigned int shndx = this->adjust_shndx(shdr.get_sh_info());
269 this->error(_("relocation section %u has bad info %u"),
274 Output_section* os = out_sections[shndx];
278 // We are scanning relocations in order to fill out the GOT and
279 // PLT sections. Relocations for sections which are not
280 // allocated (typically debugging sections) should not add new
281 // GOT and PLT entries. So we skip them unless this is a
282 // relocatable link or we need to emit relocations. FIXME: What
283 // should we do if a linker script maps a section with SHF_ALLOC
284 // clear to a section with SHF_ALLOC set?
285 typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
286 bool is_section_allocated = ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC)
288 if (!is_section_allocated
289 && !parameters->options().relocatable()
290 && !parameters->options().emit_relocs())
293 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
295 this->error(_("relocation section %u uses unexpected "
297 i, this->adjust_shndx(shdr.get_sh_link()));
301 off_t sh_size = shdr.get_sh_size();
303 unsigned int reloc_size;
304 if (sh_type == elfcpp::SHT_REL)
305 reloc_size = elfcpp::Elf_sizes<size>::rel_size;
307 reloc_size = elfcpp::Elf_sizes<size>::rela_size;
308 if (reloc_size != shdr.get_sh_entsize())
310 this->error(_("unexpected entsize for reloc section %u: %lu != %u"),
311 i, static_cast<unsigned long>(shdr.get_sh_entsize()),
316 size_t reloc_count = sh_size / reloc_size;
317 if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
319 this->error(_("reloc section %u size %lu uneven"),
320 i, static_cast<unsigned long>(sh_size));
324 rd->relocs.push_back(Section_relocs());
325 Section_relocs& sr(rd->relocs.back());
327 sr.data_shndx = shndx;
328 sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
330 sr.sh_type = sh_type;
331 sr.reloc_count = reloc_count;
332 sr.output_section = os;
333 sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address;
334 sr.is_data_section_allocated = is_section_allocated;
337 // Read the local symbols.
338 gold_assert(this->symtab_shndx_ != -1U);
339 if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0)
340 rd->local_symbols = NULL;
343 typename This::Shdr symtabshdr(pshdrs
344 + this->symtab_shndx_ * This::shdr_size);
345 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
346 const int sym_size = This::sym_size;
347 const unsigned int loccount = this->local_symbol_count_;
348 gold_assert(loccount == symtabshdr.get_sh_info());
349 off_t locsize = loccount * sym_size;
350 rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
351 locsize, true, true);
355 // Process the relocs to generate mappings from source sections to referenced
356 // sections. This is used during garbage colletion to determine garbage
359 template<int size, bool big_endian>
361 Sized_relobj<size, big_endian>::do_gc_process_relocs(const General_options& options,
362 Symbol_table* symtab,
364 Read_relocs_data* rd)
366 Sized_target<size, big_endian>* target =
367 parameters->sized_target<size, big_endian>();
369 const unsigned char* local_symbols;
370 if (rd->local_symbols == NULL)
371 local_symbols = NULL;
373 local_symbols = rd->local_symbols->data();
375 for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
376 p != rd->relocs.end();
379 if (!parameters->options().relocatable())
381 // As noted above, when not generating an object file, we
382 // only scan allocated sections. We may see a non-allocated
383 // section here if we are emitting relocs.
384 if (p->is_data_section_allocated)
385 target->gc_process_relocs(options, symtab, layout, this,
386 p->data_shndx, p->sh_type,
387 p->contents->data(), p->reloc_count,
389 p->needs_special_offset_handling,
390 this->local_symbol_count_,
397 // Scan the relocs and adjust the symbol table. This looks for
398 // relocations which require GOT/PLT/COPY relocations.
400 template<int size, bool big_endian>
402 Sized_relobj<size, big_endian>::do_scan_relocs(const General_options& options,
403 Symbol_table* symtab,
405 Read_relocs_data* rd)
407 Sized_target<size, big_endian>* target =
408 parameters->sized_target<size, big_endian>();
410 const unsigned char* local_symbols;
411 if (rd->local_symbols == NULL)
412 local_symbols = NULL;
414 local_symbols = rd->local_symbols->data();
416 for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
417 p != rd->relocs.end();
420 // When garbage collection is on, unreferenced sections are not included
421 // in the link that would have been included normally. This is known only
422 // after Read_relocs hence this check has to be done again.
423 if (parameters->options().gc_sections() || parameters->options().icf())
425 if (p->output_section == NULL)
428 if (!parameters->options().relocatable())
430 // As noted above, when not generating an object file, we
431 // only scan allocated sections. We may see a non-allocated
432 // section here if we are emitting relocs.
433 if (p->is_data_section_allocated)
434 target->scan_relocs(options, symtab, layout, this, p->data_shndx,
435 p->sh_type, p->contents->data(),
436 p->reloc_count, p->output_section,
437 p->needs_special_offset_handling,
438 this->local_symbol_count_,
440 if (parameters->options().emit_relocs())
441 this->emit_relocs_scan(options, symtab, layout, local_symbols, p);
445 Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
446 gold_assert(rr != NULL);
447 rr->set_reloc_count(p->reloc_count);
448 target->scan_relocatable_relocs(options, symtab, layout, this,
449 p->data_shndx, p->sh_type,
453 p->needs_special_offset_handling,
454 this->local_symbol_count_,
463 if (rd->local_symbols != NULL)
465 delete rd->local_symbols;
466 rd->local_symbols = NULL;
470 // This is a strategy class we use when scanning for --emit-relocs.
472 template<int sh_type>
473 class Emit_relocs_strategy
476 // A local non-section symbol.
477 inline Relocatable_relocs::Reloc_strategy
478 local_non_section_strategy(unsigned int, Relobj*, unsigned int)
479 { return Relocatable_relocs::RELOC_COPY; }
481 // A local section symbol.
482 inline Relocatable_relocs::Reloc_strategy
483 local_section_strategy(unsigned int, Relobj*)
485 if (sh_type == elfcpp::SHT_RELA)
486 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
489 // The addend is stored in the section contents. Since this
490 // is not a relocatable link, we are going to apply the
491 // relocation contents to the section as usual. This means
492 // that we have no way to record the original addend. If the
493 // original addend is not zero, there is basically no way for
494 // the user to handle this correctly. Caveat emptor.
495 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
500 inline Relocatable_relocs::Reloc_strategy
501 global_strategy(unsigned int, Relobj*, unsigned int)
502 { return Relocatable_relocs::RELOC_COPY; }
505 // Scan the input relocations for --emit-relocs.
507 template<int size, bool big_endian>
509 Sized_relobj<size, big_endian>::emit_relocs_scan(
510 const General_options& options,
511 Symbol_table* symtab,
513 const unsigned char* plocal_syms,
514 const Read_relocs_data::Relocs_list::iterator& p)
516 Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
517 gold_assert(rr != NULL);
518 rr->set_reloc_count(p->reloc_count);
520 if (p->sh_type == elfcpp::SHT_REL)
521 this->emit_relocs_scan_reltype<elfcpp::SHT_REL>(options, symtab, layout,
525 gold_assert(p->sh_type == elfcpp::SHT_RELA);
526 this->emit_relocs_scan_reltype<elfcpp::SHT_RELA>(options, symtab,
527 layout, plocal_syms, p,
532 // Scan the input relocation for --emit-relocs, templatized on the
533 // type of the relocation section.
535 template<int size, bool big_endian>
536 template<int sh_type>
538 Sized_relobj<size, big_endian>::emit_relocs_scan_reltype(
539 const General_options& options,
540 Symbol_table* symtab,
542 const unsigned char* plocal_syms,
543 const Read_relocs_data::Relocs_list::iterator& p,
544 Relocatable_relocs* rr)
546 scan_relocatable_relocs<size, big_endian, sh_type,
547 Emit_relocs_strategy<sh_type> >(
556 p->needs_special_offset_handling,
557 this->local_symbol_count_,
562 // Relocate the input sections and write out the local symbols.
564 template<int size, bool big_endian>
566 Sized_relobj<size, big_endian>::do_relocate(const General_options& options,
567 const Symbol_table* symtab,
568 const Layout* layout,
571 unsigned int shnum = this->shnum();
573 // Read the section headers.
574 const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
575 shnum * This::shdr_size,
581 // Make two passes over the sections. The first one copies the
582 // section data to the output file. The second one applies
585 this->write_sections(pshdrs, of, &views);
587 // To speed up relocations, we set up hash tables for fast lookup of
588 // input offsets to output addresses.
589 this->initialize_input_to_output_maps();
591 // Apply relocations.
593 this->relocate_sections(options, symtab, layout, pshdrs, &views);
595 // After we've done the relocations, we release the hash tables,
596 // since we no longer need them.
597 this->free_input_to_output_maps();
599 // Write out the accumulated views.
600 for (unsigned int i = 1; i < shnum; ++i)
602 if (views[i].view != NULL)
604 if (!views[i].is_postprocessing_view)
606 if (views[i].is_input_output_view)
607 of->write_input_output_view(views[i].offset,
611 of->write_output_view(views[i].offset, views[i].view_size,
617 // Write out the local symbols.
618 this->write_local_symbols(of, layout->sympool(), layout->dynpool(),
619 layout->symtab_xindex(), layout->dynsym_xindex());
621 // We should no longer need the local symbol values.
622 this->clear_local_symbols();
625 // Sort a Read_multiple vector by file offset.
626 struct Read_multiple_compare
629 operator()(const File_read::Read_multiple_entry& rme1,
630 const File_read::Read_multiple_entry& rme2) const
631 { return rme1.file_offset < rme2.file_offset; }
634 // Write section data to the output file. PSHDRS points to the
635 // section headers. Record the views in *PVIEWS for use when
638 template<int size, bool big_endian>
640 Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
644 unsigned int shnum = this->shnum();
645 const Output_sections& out_sections(this->output_sections());
646 const std::vector<Address>& out_offsets(this->section_offsets_);
648 File_read::Read_multiple rm;
649 bool is_sorted = true;
651 const unsigned char* p = pshdrs + This::shdr_size;
652 for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
654 View_size* pvs = &(*pviews)[i];
658 const Output_section* os = out_sections[i];
661 Address output_offset = out_offsets[i];
663 typename This::Shdr shdr(p);
665 if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
668 if ((parameters->options().relocatable()
669 || parameters->options().emit_relocs())
670 && (shdr.get_sh_type() == elfcpp::SHT_REL
671 || shdr.get_sh_type() == elfcpp::SHT_RELA)
672 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
674 // This is a reloc section in a relocatable link or when
675 // emitting relocs. We don't need to read the input file.
676 // The size and file offset are stored in the
677 // Relocatable_relocs structure.
678 Relocatable_relocs* rr = this->relocatable_relocs(i);
679 gold_assert(rr != NULL);
680 Output_data* posd = rr->output_data();
681 gold_assert(posd != NULL);
683 pvs->offset = posd->offset();
684 pvs->view_size = posd->data_size();
685 pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
686 pvs->address = posd->address();
687 pvs->is_input_output_view = false;
688 pvs->is_postprocessing_view = false;
693 // In the normal case, this input section is simply mapped to
694 // the output section at offset OUTPUT_OFFSET.
696 // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
697 // handled specially--e.g., a .eh_frame section. The relocation
698 // routines need to check for each reloc where it should be
699 // applied. For this case, we need an input/output view for the
700 // entire contents of the section in the output file. We don't
701 // want to copy the contents of the input section to the output
702 // section; the output section contents were already written,
703 // and we waited for them in Relocate_task::is_runnable because
704 // relocs_must_follow_section_writes is set for the object.
706 // Regardless of which of the above cases is true, we have to
707 // check requires_postprocessing of the output section. If that
708 // is false, then we work with views of the output file
709 // directly. If it is true, then we work with a separate
710 // buffer, and the output section is responsible for writing the
711 // final data to the output file.
713 off_t output_section_offset;
714 Address output_section_size;
715 if (!os->requires_postprocessing())
717 output_section_offset = os->offset();
718 output_section_size = convert_types<Address, off_t>(os->data_size());
722 output_section_offset = 0;
723 output_section_size =
724 convert_types<Address, off_t>(os->postprocessing_buffer_size());
728 section_size_type view_size;
729 if (output_offset != invalid_address)
731 view_start = output_section_offset + output_offset;
732 view_size = convert_to_section_size_type(shdr.get_sh_size());
736 view_start = output_section_offset;
737 view_size = convert_to_section_size_type(output_section_size);
743 gold_assert(output_offset == invalid_address
744 || output_offset + view_size <= output_section_size);
747 if (os->requires_postprocessing())
749 unsigned char* buffer = os->postprocessing_buffer();
750 view = buffer + view_start;
751 if (output_offset != invalid_address)
753 off_t sh_offset = shdr.get_sh_offset();
754 if (!rm.empty() && rm.back().file_offset > sh_offset)
756 rm.push_back(File_read::Read_multiple_entry(sh_offset,
762 if (output_offset == invalid_address)
763 view = of->get_input_output_view(view_start, view_size);
766 view = of->get_output_view(view_start, view_size);
767 off_t sh_offset = shdr.get_sh_offset();
768 if (!rm.empty() && rm.back().file_offset > sh_offset)
770 rm.push_back(File_read::Read_multiple_entry(sh_offset,
776 pvs->address = os->address();
777 if (output_offset != invalid_address)
778 pvs->address += output_offset;
779 pvs->offset = view_start;
780 pvs->view_size = view_size;
781 pvs->is_input_output_view = output_offset == invalid_address;
782 pvs->is_postprocessing_view = os->requires_postprocessing();
785 // Actually read the data.
789 std::sort(rm.begin(), rm.end(), Read_multiple_compare());
790 this->read_multiple(rm);
794 // Relocate section data. VIEWS points to the section data as views
795 // in the output file.
797 template<int size, bool big_endian>
799 Sized_relobj<size, big_endian>::relocate_sections(
800 const General_options& options,
801 const Symbol_table* symtab,
802 const Layout* layout,
803 const unsigned char* pshdrs,
806 unsigned int shnum = this->shnum();
807 Sized_target<size, big_endian>* target =
808 parameters->sized_target<size, big_endian>();
810 const Output_sections& out_sections(this->output_sections());
811 const std::vector<Address>& out_offsets(this->section_offsets_);
813 Relocate_info<size, big_endian> relinfo;
814 relinfo.options = &options;
815 relinfo.symtab = symtab;
816 relinfo.layout = layout;
817 relinfo.object = this;
819 const unsigned char* p = pshdrs + This::shdr_size;
820 for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
822 typename This::Shdr shdr(p);
824 unsigned int sh_type = shdr.get_sh_type();
825 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
828 off_t sh_size = shdr.get_sh_size();
832 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
833 if (index >= this->shnum())
835 this->error(_("relocation section %u has bad info %u"),
840 Output_section* os = out_sections[index];
843 // This relocation section is against a section which we
847 Address output_offset = out_offsets[index];
849 gold_assert((*pviews)[index].view != NULL);
850 if (parameters->options().relocatable())
851 gold_assert((*pviews)[i].view != NULL);
853 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
855 gold_error(_("relocation section %u uses unexpected "
857 i, this->adjust_shndx(shdr.get_sh_link()));
861 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
862 sh_size, true, false);
864 unsigned int reloc_size;
865 if (sh_type == elfcpp::SHT_REL)
866 reloc_size = elfcpp::Elf_sizes<size>::rel_size;
868 reloc_size = elfcpp::Elf_sizes<size>::rela_size;
870 if (reloc_size != shdr.get_sh_entsize())
872 gold_error(_("unexpected entsize for reloc section %u: %lu != %u"),
873 i, static_cast<unsigned long>(shdr.get_sh_entsize()),
878 size_t reloc_count = sh_size / reloc_size;
879 if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
881 gold_error(_("reloc section %u size %lu uneven"),
882 i, static_cast<unsigned long>(sh_size));
886 gold_assert(output_offset != invalid_address
887 || this->relocs_must_follow_section_writes());
889 relinfo.reloc_shndx = i;
890 relinfo.data_shndx = index;
891 unsigned char* view = (*pviews)[index].view;
892 Address address = (*pviews)[index].address;
893 section_size_type view_size = (*pviews)[index].view_size;
895 Reloc_symbol_changes* reloc_map = NULL;
896 if (this->uses_split_stack() && output_offset != invalid_address)
898 typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
899 if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
900 this->split_stack_adjust(symtab, pshdrs, sh_type, index,
901 prelocs, reloc_count, view, view_size,
905 if (!parameters->options().relocatable())
907 target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
908 output_offset == invalid_address,
909 view, address, view_size, reloc_map);
910 if (parameters->options().emit_relocs())
911 this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
912 os, output_offset, view, address, view_size,
913 (*pviews)[i].view, (*pviews)[i].view_size);
917 Relocatable_relocs* rr = this->relocatable_relocs(i);
918 target->relocate_for_relocatable(&relinfo, sh_type, prelocs,
919 reloc_count, os, output_offset, rr,
920 view, address, view_size,
922 (*pviews)[i].view_size);
927 // Emit the relocs for --emit-relocs.
929 template<int size, bool big_endian>
931 Sized_relobj<size, big_endian>::emit_relocs(
932 const Relocate_info<size, big_endian>* relinfo,
934 unsigned int sh_type,
935 const unsigned char* prelocs,
937 Output_section* output_section,
938 typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
940 typename elfcpp::Elf_types<size>::Elf_Addr address,
941 section_size_type view_size,
942 unsigned char* reloc_view,
943 section_size_type reloc_view_size)
945 if (sh_type == elfcpp::SHT_REL)
946 this->emit_relocs_reltype<elfcpp::SHT_REL>(relinfo, i, prelocs,
947 reloc_count, output_section,
948 offset_in_output_section,
949 view, address, view_size,
950 reloc_view, reloc_view_size);
953 gold_assert(sh_type == elfcpp::SHT_RELA);
954 this->emit_relocs_reltype<elfcpp::SHT_RELA>(relinfo, i, prelocs,
955 reloc_count, output_section,
956 offset_in_output_section,
957 view, address, view_size,
958 reloc_view, reloc_view_size);
962 // Emit the relocs for --emit-relocs, templatized on the type of the
963 // relocation section.
965 template<int size, bool big_endian>
966 template<int sh_type>
968 Sized_relobj<size, big_endian>::emit_relocs_reltype(
969 const Relocate_info<size, big_endian>* relinfo,
971 const unsigned char* prelocs,
973 Output_section* output_section,
974 typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
976 typename elfcpp::Elf_types<size>::Elf_Addr address,
977 section_size_type view_size,
978 unsigned char* reloc_view,
979 section_size_type reloc_view_size)
981 const Relocatable_relocs* rr = this->relocatable_relocs(i);
982 relocate_for_relocatable<size, big_endian, sh_type>(
987 offset_in_output_section,
996 // Create merge hash tables for the local symbols. These are used to
997 // speed up relocations.
999 template<int size, bool big_endian>
1001 Sized_relobj<size, big_endian>::initialize_input_to_output_maps()
1003 const unsigned int loccount = this->local_symbol_count_;
1004 for (unsigned int i = 1; i < loccount; ++i)
1006 Symbol_value<size>& lv(this->local_values_[i]);
1007 lv.initialize_input_to_output_map(this);
1011 // Free merge hash tables for the local symbols.
1013 template<int size, bool big_endian>
1015 Sized_relobj<size, big_endian>::free_input_to_output_maps()
1017 const unsigned int loccount = this->local_symbol_count_;
1018 for (unsigned int i = 1; i < loccount; ++i)
1020 Symbol_value<size>& lv(this->local_values_[i]);
1021 lv.free_input_to_output_map();
1025 // If an object was compiled with -fsplit-stack, this is called to
1026 // check whether any relocations refer to functions defined in objects
1027 // which were not compiled with -fsplit-stack. If they were, then we
1028 // need to apply some target-specific adjustments to request
1029 // additional stack space.
1031 template<int size, bool big_endian>
1033 Sized_relobj<size, big_endian>::split_stack_adjust(
1034 const Symbol_table* symtab,
1035 const unsigned char* pshdrs,
1036 unsigned int sh_type,
1038 const unsigned char* prelocs,
1040 unsigned char* view,
1041 section_size_type view_size,
1042 Reloc_symbol_changes** reloc_map)
1044 if (sh_type == elfcpp::SHT_REL)
1045 this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
1046 prelocs, reloc_count,
1051 gold_assert(sh_type == elfcpp::SHT_RELA);
1052 this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
1053 prelocs, reloc_count,
1059 // Adjust for -fsplit-stack, templatized on the type of the relocation
1062 template<int size, bool big_endian>
1063 template<int sh_type>
1065 Sized_relobj<size, big_endian>::split_stack_adjust_reltype(
1066 const Symbol_table* symtab,
1067 const unsigned char* pshdrs,
1069 const unsigned char* prelocs,
1071 unsigned char* view,
1072 section_size_type view_size,
1073 Reloc_symbol_changes** reloc_map)
1075 typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
1076 const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
1078 size_t local_count = this->local_symbol_count();
1080 std::vector<section_offset_type> non_split_refs;
1082 const unsigned char* pr = prelocs;
1083 for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1087 typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
1088 unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1089 if (r_sym < local_count)
1092 const Symbol* gsym = this->global_symbol(r_sym);
1093 gold_assert(gsym != NULL);
1094 if (gsym->is_forwarder())
1095 gsym = symtab->resolve_forwards(gsym);
1097 // See if this relocation refers to a function defined in an
1098 // object compiled without -fsplit-stack. Note that we don't
1099 // care about the type of relocation--this means that in some
1100 // cases we will ask for a large stack unnecessarily, but this
1101 // is not fatal. FIXME: Some targets have symbols which are
1102 // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
1103 if (gsym->type() == elfcpp::STT_FUNC
1104 && !gsym->is_undefined()
1105 && gsym->source() == Symbol::FROM_OBJECT
1106 && !gsym->object()->uses_split_stack())
1108 section_offset_type offset =
1109 convert_to_section_size_type(reloc.get_r_offset());
1110 non_split_refs.push_back(offset);
1114 if (non_split_refs.empty())
1117 // At this point, every entry in NON_SPLIT_REFS indicates a
1118 // relocation which refers to a function in an object compiled
1119 // without -fsplit-stack. We now have to convert that list into a
1120 // set of offsets to functions. First, we find all the functions.
1122 Function_offsets function_offsets;
1123 this->find_functions(pshdrs, shndx, &function_offsets);
1124 if (function_offsets.empty())
1127 // Now get a list of the function with references to non split-stack
1130 Function_offsets calls_non_split;
1131 for (std::vector<section_offset_type>::const_iterator p
1132 = non_split_refs.begin();
1133 p != non_split_refs.end();
1136 Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
1137 if (low == function_offsets.end())
1139 else if (low->first == *p)
1141 else if (low == function_offsets.begin())
1146 calls_non_split.insert(*low);
1148 if (calls_non_split.empty())
1151 // Now we have a set of functions to adjust. The adjustments are
1152 // target specific. Besides changing the output section view
1153 // however, it likes, the target may request a relocation change
1154 // from one global symbol name to another.
1156 for (Function_offsets::const_iterator p = calls_non_split.begin();
1157 p != calls_non_split.end();
1162 parameters->target().calls_non_split(this, shndx, p->first, p->second,
1163 view, view_size, &from, &to);
1166 gold_assert(!to.empty());
1167 Symbol* tosym = NULL;
1169 // Find relocations in the relevant function which are for
1172 for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
1176 typename elfcpp::Elf_types<size>::Elf_WXword r_info =
1178 unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
1179 if (r_sym < local_count)
1182 section_offset_type offset =
1183 convert_to_section_size_type(reloc.get_r_offset());
1184 if (offset < p->first
1187 + static_cast<section_offset_type>(p->second))))
1190 const Symbol* gsym = this->global_symbol(r_sym);
1191 if (from == gsym->name())
1195 tosym = symtab->lookup(to.c_str());
1198 this->error(_("could not convert call "
1200 from.c_str(), to.c_str());
1205 if (*reloc_map == NULL)
1206 *reloc_map = new Reloc_symbol_changes(reloc_count);
1207 (*reloc_map)->set(i, tosym);
1214 // Find all the function in this object defined in section SHNDX.
1215 // Store their offsets in the section in FUNCTION_OFFSETS.
1217 template<int size, bool big_endian>
1219 Sized_relobj<size, big_endian>::find_functions(
1220 const unsigned char* pshdrs,
1222 Sized_relobj<size, big_endian>::Function_offsets* function_offsets)
1224 // We need to read the symbols to find the functions. If we wanted
1225 // to, we could cache reading the symbols across all sections in the
1227 const unsigned int symtab_shndx = this->symtab_shndx_;
1228 typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
1229 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1231 typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
1232 symtabshdr.get_sh_size();
1233 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1234 sh_size, true, true);
1236 const int sym_size = This::sym_size;
1237 const unsigned int symcount = sh_size / sym_size;
1238 for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
1240 typename elfcpp::Sym<size, big_endian> isym(psyms);
1242 // FIXME: Some targets can have functions which do not have type
1243 // STT_FUNC, e.g., STT_ARM_TFUNC.
1244 if (isym.get_st_type() != elfcpp::STT_FUNC
1245 || isym.get_st_size() == 0)
1249 unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
1251 if (!is_ordinary || sym_shndx != shndx)
1254 section_offset_type value =
1255 convert_to_section_size_type(isym.get_st_value());
1256 section_size_type fnsize =
1257 convert_to_section_size_type(isym.get_st_size());
1259 (*function_offsets)[value] = fnsize;
1263 // Class Merged_symbol_value.
1267 Merged_symbol_value<size>::initialize_input_to_output_map(
1268 const Relobj* object,
1269 unsigned int input_shndx)
1271 Object_merge_map* map = object->merge_map();
1272 map->initialize_input_to_output_map<size>(input_shndx,
1273 this->output_start_address_,
1274 &this->output_addresses_);
1277 // Get the output value corresponding to an input offset if we
1278 // couldn't find it in the hash table.
1281 typename elfcpp::Elf_types<size>::Elf_Addr
1282 Merged_symbol_value<size>::value_from_output_section(
1283 const Relobj* object,
1284 unsigned int input_shndx,
1285 typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
1287 section_offset_type output_offset;
1288 bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
1292 // If this assertion fails, it means that some relocation was
1293 // against a portion of an input merge section which we didn't map
1294 // to the output file and we didn't explicitly discard. We should
1295 // always map all portions of input merge sections.
1298 if (output_offset == -1)
1301 return this->output_start_address_ + output_offset;
1304 // Track_relocs methods.
1306 // Initialize the class to track the relocs. This gets the object,
1307 // the reloc section index, and the type of the relocs. This returns
1308 // false if something goes wrong.
1310 template<int size, bool big_endian>
1312 Track_relocs<size, big_endian>::initialize(
1314 unsigned int reloc_shndx,
1315 unsigned int reloc_type)
1317 // If RELOC_SHNDX is -1U, it means there is more than one reloc
1318 // section for the .eh_frame section. We can't handle that case.
1319 if (reloc_shndx == -1U)
1322 // If RELOC_SHNDX is 0, there is no reloc section.
1323 if (reloc_shndx == 0)
1326 // Get the contents of the reloc section.
1327 this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false);
1329 if (reloc_type == elfcpp::SHT_REL)
1330 this->reloc_size_ = elfcpp::Elf_sizes<size>::rel_size;
1331 else if (reloc_type == elfcpp::SHT_RELA)
1332 this->reloc_size_ = elfcpp::Elf_sizes<size>::rela_size;
1336 if (this->len_ % this->reloc_size_ != 0)
1338 object->error(_("reloc section size %zu is not a multiple of "
1340 static_cast<size_t>(this->len_),
1348 // Return the offset of the next reloc, or -1 if there isn't one.
1350 template<int size, bool big_endian>
1352 Track_relocs<size, big_endian>::next_offset() const
1354 if (this->pos_ >= this->len_)
1357 // Rel and Rela start out the same, so we can always use Rel to find
1358 // the r_offset value.
1359 elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1360 return rel.get_r_offset();
1363 // Return the index of the symbol referenced by the next reloc, or -1U
1364 // if there aren't any more relocs.
1366 template<int size, bool big_endian>
1368 Track_relocs<size, big_endian>::next_symndx() const
1370 if (this->pos_ >= this->len_)
1373 // Rel and Rela start out the same, so we can use Rel to find the
1375 elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1376 return elfcpp::elf_r_sym<size>(rel.get_r_info());
1379 // Advance to the next reloc whose r_offset is greater than or equal
1380 // to OFFSET. Return the number of relocs we skip.
1382 template<int size, bool big_endian>
1384 Track_relocs<size, big_endian>::advance(off_t offset)
1387 while (this->pos_ < this->len_)
1389 // Rel and Rela start out the same, so we can always use Rel to
1390 // find the r_offset value.
1391 elfcpp::Rel<size, big_endian> rel(this->prelocs_ + this->pos_);
1392 if (static_cast<off_t>(rel.get_r_offset()) >= offset)
1395 this->pos_ += this->reloc_size_;
1400 // Instantiate the templates we need.
1402 #ifdef HAVE_TARGET_32_LITTLE
1405 Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd);
1408 #ifdef HAVE_TARGET_32_BIG
1411 Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd);
1414 #ifdef HAVE_TARGET_64_LITTLE
1417 Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd);
1420 #ifdef HAVE_TARGET_64_BIG
1423 Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
1426 #ifdef HAVE_TARGET_32_LITTLE
1429 Sized_relobj<32, false>::do_gc_process_relocs(const General_options& options,
1430 Symbol_table* symtab,
1432 Read_relocs_data* rd);
1435 #ifdef HAVE_TARGET_32_BIG
1438 Sized_relobj<32, true>::do_gc_process_relocs(const General_options& options,
1439 Symbol_table* symtab,
1441 Read_relocs_data* rd);
1444 #ifdef HAVE_TARGET_64_LITTLE
1447 Sized_relobj<64, false>::do_gc_process_relocs(const General_options& options,
1448 Symbol_table* symtab,
1450 Read_relocs_data* rd);
1453 #ifdef HAVE_TARGET_64_BIG
1456 Sized_relobj<64, true>::do_gc_process_relocs(const General_options& options,
1457 Symbol_table* symtab,
1459 Read_relocs_data* rd);
1462 #ifdef HAVE_TARGET_32_LITTLE
1465 Sized_relobj<32, false>::do_scan_relocs(const General_options& options,
1466 Symbol_table* symtab,
1468 Read_relocs_data* rd);
1471 #ifdef HAVE_TARGET_32_BIG
1474 Sized_relobj<32, true>::do_scan_relocs(const General_options& options,
1475 Symbol_table* symtab,
1477 Read_relocs_data* rd);
1480 #ifdef HAVE_TARGET_64_LITTLE
1483 Sized_relobj<64, false>::do_scan_relocs(const General_options& options,
1484 Symbol_table* symtab,
1486 Read_relocs_data* rd);
1489 #ifdef HAVE_TARGET_64_BIG
1492 Sized_relobj<64, true>::do_scan_relocs(const General_options& options,
1493 Symbol_table* symtab,
1495 Read_relocs_data* rd);
1498 #ifdef HAVE_TARGET_32_LITTLE
1501 Sized_relobj<32, false>::do_relocate(const General_options& options,
1502 const Symbol_table* symtab,
1503 const Layout* layout,
1507 #ifdef HAVE_TARGET_32_BIG
1510 Sized_relobj<32, true>::do_relocate(const General_options& options,
1511 const Symbol_table* symtab,
1512 const Layout* layout,
1516 #ifdef HAVE_TARGET_64_LITTLE
1519 Sized_relobj<64, false>::do_relocate(const General_options& options,
1520 const Symbol_table* symtab,
1521 const Layout* layout,
1525 #ifdef HAVE_TARGET_64_BIG
1528 Sized_relobj<64, true>::do_relocate(const General_options& options,
1529 const Symbol_table* symtab,
1530 const Layout* layout,
1534 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1536 class Merged_symbol_value<32>;
1539 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1541 class Merged_symbol_value<64>;
1544 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1546 class Symbol_value<32>;
1549 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1551 class Symbol_value<64>;
1554 #ifdef HAVE_TARGET_32_LITTLE
1556 class Track_relocs<32, false>;
1559 #ifdef HAVE_TARGET_32_BIG
1561 class Track_relocs<32, true>;
1564 #ifdef HAVE_TARGET_64_LITTLE
1566 class Track_relocs<64, false>;
1569 #ifdef HAVE_TARGET_64_BIG
1571 class Track_relocs<64, true>;
1574 } // End namespace gold.