1 // object.cc -- support for an object file for linking in gold
3 // Copyright 2006, 2007 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.
29 #include "target-select.h"
30 #include "dwarf_reader.h"
42 // Set the target based on fields in the ELF file header.
45 Object::set_target(int machine, int size, bool big_endian, int osabi,
48 Target* target = select_target(machine, size, big_endian, osabi, abiversion);
50 gold_fatal(_("%s: unsupported ELF machine number %d"),
51 this->name().c_str(), machine);
52 this->target_ = target;
55 // Report an error for this object file. This is used by the
56 // elfcpp::Elf_file interface, and also called by the Object code
60 Object::error(const char* format, ...) const
63 va_start(args, format);
65 if (vasprintf(&buf, format, args) < 0)
68 gold_error(_("%s: %s"), this->name().c_str(), buf);
72 // Return a view of the contents of a section.
75 Object::section_contents(unsigned int shndx, off_t* plen, bool cache)
77 Location loc(this->do_section_contents(shndx));
78 *plen = loc.data_size;
79 return this->get_view(loc.file_offset, loc.data_size, cache);
82 // Read the section data into SD. This is code common to Sized_relobj
83 // and Sized_dynobj, so we put it into Object.
85 template<int size, bool big_endian>
87 Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
88 Read_symbols_data* sd)
90 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
92 // Read the section headers.
93 const off_t shoff = elf_file->shoff();
94 const unsigned int shnum = this->shnum();
95 sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size, true);
97 // Read the section names.
98 const unsigned char* pshdrs = sd->section_headers->data();
99 const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
100 typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
102 if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
103 this->error(_("section name section has wrong type: %u"),
104 static_cast<unsigned int>(shdrnames.get_sh_type()));
106 sd->section_names_size = shdrnames.get_sh_size();
107 sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
108 sd->section_names_size, false);
111 // If NAME is the name of a special .gnu.warning section, arrange for
112 // the warning to be issued. SHNDX is the section index. Return
113 // whether it is a warning section.
116 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
117 Symbol_table* symtab)
119 const char warn_prefix[] = ".gnu.warning.";
120 const int warn_prefix_len = sizeof warn_prefix - 1;
121 if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
123 symtab->add_warning(name + warn_prefix_len, this, shndx);
129 // Class Sized_relobj.
131 template<int size, bool big_endian>
132 Sized_relobj<size, big_endian>::Sized_relobj(
133 const std::string& name,
134 Input_file* input_file,
136 const elfcpp::Ehdr<size, big_endian>& ehdr)
137 : Relobj(name, input_file, offset),
138 elf_file_(this, ehdr),
140 local_symbol_count_(0),
141 output_local_symbol_count_(0),
143 local_symbol_offset_(0),
149 template<int size, bool big_endian>
150 Sized_relobj<size, big_endian>::~Sized_relobj()
154 // Set up an object file based on the file header. This sets up the
155 // target and reads the section information.
157 template<int size, bool big_endian>
159 Sized_relobj<size, big_endian>::setup(
160 const elfcpp::Ehdr<size, big_endian>& ehdr)
162 this->set_target(ehdr.get_e_machine(), size, big_endian,
163 ehdr.get_e_ident()[elfcpp::EI_OSABI],
164 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
166 const unsigned int shnum = this->elf_file_.shnum();
167 this->set_shnum(shnum);
170 // Find the SHT_SYMTAB section, given the section headers. The ELF
171 // standard says that maybe in the future there can be more than one
172 // SHT_SYMTAB section. Until somebody figures out how that could
173 // work, we assume there is only one.
175 template<int size, bool big_endian>
177 Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
179 const unsigned int shnum = this->shnum();
180 this->symtab_shndx_ = 0;
183 // Look through the sections in reverse order, since gas tends
184 // to put the symbol table at the end.
185 const unsigned char* p = pshdrs + shnum * This::shdr_size;
186 unsigned int i = shnum;
190 p -= This::shdr_size;
191 typename This::Shdr shdr(p);
192 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
194 this->symtab_shndx_ = i;
201 // Read the sections and symbols from an object file.
203 template<int size, bool big_endian>
205 Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
207 this->read_section_data(&this->elf_file_, sd);
209 const unsigned char* const pshdrs = sd->section_headers->data();
211 this->find_symtab(pshdrs);
214 sd->symbols_size = 0;
215 sd->symbol_names = NULL;
216 sd->symbol_names_size = 0;
218 if (this->symtab_shndx_ == 0)
220 // No symbol table. Weird but legal.
224 // Get the symbol table section header.
225 typename This::Shdr symtabshdr(pshdrs
226 + this->symtab_shndx_ * This::shdr_size);
227 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
229 // We only need the external symbols.
230 const int sym_size = This::sym_size;
231 const unsigned int loccount = symtabshdr.get_sh_info();
232 this->local_symbol_count_ = loccount;
233 off_t locsize = loccount * sym_size;
234 off_t extoff = symtabshdr.get_sh_offset() + locsize;
235 off_t extsize = symtabshdr.get_sh_size() - locsize;
237 // Read the symbol table.
238 File_view* fvsymtab = this->get_lasting_view(extoff, extsize, false);
240 // Read the section header for the symbol names.
241 unsigned int strtab_shndx = symtabshdr.get_sh_link();
242 if (strtab_shndx >= this->shnum())
244 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
247 typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
248 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
250 this->error(_("symbol table name section has wrong type: %u"),
251 static_cast<unsigned int>(strtabshdr.get_sh_type()));
255 // Read the symbol names.
256 File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
257 strtabshdr.get_sh_size(), true);
259 sd->symbols = fvsymtab;
260 sd->symbols_size = extsize;
261 sd->symbol_names = fvstrtab;
262 sd->symbol_names_size = strtabshdr.get_sh_size();
265 // Return whether to include a section group in the link. LAYOUT is
266 // used to keep track of which section groups we have already seen.
267 // INDEX is the index of the section group and SHDR is the section
268 // header. If we do not want to include this group, we set bits in
269 // OMIT for each section which should be discarded.
271 template<int size, bool big_endian>
273 Sized_relobj<size, big_endian>::include_section_group(
276 const elfcpp::Shdr<size, big_endian>& shdr,
277 std::vector<bool>* omit)
279 // Read the section contents.
280 const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
281 shdr.get_sh_size(), false);
282 const elfcpp::Elf_Word* pword =
283 reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
285 // The first word contains flags. We only care about COMDAT section
286 // groups. Other section groups are always included in the link
287 // just like ordinary sections.
288 elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
289 if ((flags & elfcpp::GRP_COMDAT) == 0)
292 // Look up the group signature, which is the name of a symbol. This
293 // is a lot of effort to go to to read a string. Why didn't they
294 // just use the name of the SHT_GROUP section as the group
297 // Get the appropriate symbol table header (this will normally be
298 // the single SHT_SYMTAB section, but in principle it need not be).
299 const unsigned int link = shdr.get_sh_link();
300 typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
302 // Read the symbol table entry.
303 if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size)
305 this->error(_("section group %u info %u out of range"),
306 index, shdr.get_sh_info());
309 off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size;
310 const unsigned char* psym = this->get_view(symoff, This::sym_size, true);
311 elfcpp::Sym<size, big_endian> sym(psym);
313 // Read the symbol table names.
315 const unsigned char* psymnamesu;
316 psymnamesu = this->section_contents(symshdr.get_sh_link(), &symnamelen,
318 const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
320 // Get the section group signature.
321 if (sym.get_st_name() >= symnamelen)
323 this->error(_("symbol %u name offset %u out of range"),
324 shdr.get_sh_info(), sym.get_st_name());
328 const char* signature = psymnames + sym.get_st_name();
330 // It seems that some versions of gas will create a section group
331 // associated with a section symbol, and then fail to give a name to
332 // the section symbol. In such a case, use the name of the section.
335 if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
337 secname = this->section_name(sym.get_st_shndx());
338 signature = secname.c_str();
341 // Record this section group, and see whether we've already seen one
342 // with the same signature.
343 if (layout->add_comdat(signature, true))
346 // This is a duplicate. We want to discard the sections in this
348 size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
349 for (size_t i = 1; i < count; ++i)
351 elfcpp::Elf_Word secnum =
352 elfcpp::Swap<32, big_endian>::readval(pword + i);
353 if (secnum >= this->shnum())
355 this->error(_("section %u in section group %u out of range"),
359 (*omit)[secnum] = true;
365 // Whether to include a linkonce section in the link. NAME is the
366 // name of the section and SHDR is the section header.
368 // Linkonce sections are a GNU extension implemented in the original
369 // GNU linker before section groups were defined. The semantics are
370 // that we only include one linkonce section with a given name. The
371 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
372 // where T is the type of section and SYMNAME is the name of a symbol.
373 // In an attempt to make linkonce sections interact well with section
374 // groups, we try to identify SYMNAME and use it like a section group
375 // signature. We want to block section groups with that signature,
376 // but not other linkonce sections with that signature. We also use
377 // the full name of the linkonce section as a normal section group
380 template<int size, bool big_endian>
382 Sized_relobj<size, big_endian>::include_linkonce_section(
385 const elfcpp::Shdr<size, big_endian>&)
387 // In general the symbol name we want will be the string following
388 // the last '.'. However, we have to handle the case of
389 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
390 // some versions of gcc. So we use a heuristic: if the name starts
391 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
392 // we look for the last '.'. We can't always simply skip
393 // ".gnu.linkonce.X", because we have to deal with cases like
394 // ".gnu.linkonce.d.rel.ro.local".
395 const char* const linkonce_t = ".gnu.linkonce.t.";
397 if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
398 symname = name + strlen(linkonce_t);
400 symname = strrchr(name, '.') + 1;
401 bool include1 = layout->add_comdat(symname, false);
402 bool include2 = layout->add_comdat(name, true);
403 return include1 && include2;
406 // Lay out the input sections. We walk through the sections and check
407 // whether they should be included in the link. If they should, we
408 // pass them to the Layout object, which will return an output section
411 template<int size, bool big_endian>
413 Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
415 Read_symbols_data* sd)
417 const unsigned int shnum = this->shnum();
421 // Get the section headers.
422 const unsigned char* pshdrs = sd->section_headers->data();
424 // Get the section names.
425 const unsigned char* pnamesu = sd->section_names->data();
426 const char* pnames = reinterpret_cast<const char*>(pnamesu);
428 std::vector<Map_to_output>& map_sections(this->map_to_output());
429 map_sections.resize(shnum);
431 // Whether we've seen a .note.GNU-stack section.
432 bool seen_gnu_stack = false;
433 // The flags of a .note.GNU-stack section.
434 uint64_t gnu_stack_flags = 0;
436 // Keep track of which sections to omit.
437 std::vector<bool> omit(shnum, false);
439 // Skip the first, dummy, section.
440 pshdrs += This::shdr_size;
441 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
443 typename This::Shdr shdr(pshdrs);
445 if (shdr.get_sh_name() >= sd->section_names_size)
447 this->error(_("bad section name offset for section %u: %lu"),
448 i, static_cast<unsigned long>(shdr.get_sh_name()));
452 const char* name = pnames + shdr.get_sh_name();
454 if (this->handle_gnu_warning_section(name, i, symtab))
456 if (!parameters->output_is_object())
460 // The .note.GNU-stack section is special. It gives the
461 // protection flags that this object file requires for the stack
463 if (strcmp(name, ".note.GNU-stack") == 0)
465 seen_gnu_stack = true;
466 gnu_stack_flags |= shdr.get_sh_flags();
470 bool discard = omit[i];
473 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
475 if (!this->include_section_group(layout, i, shdr, &omit))
478 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
479 && Layout::is_linkonce(name))
481 if (!this->include_linkonce_section(layout, name, shdr))
488 // Do not include this section in the link.
489 map_sections[i].output_section = NULL;
494 Output_section* os = layout->layout(this, i, name, shdr, &offset);
496 map_sections[i].output_section = os;
497 map_sections[i].offset = offset;
500 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
502 delete sd->section_headers;
503 sd->section_headers = NULL;
504 delete sd->section_names;
505 sd->section_names = NULL;
508 // Add the symbols to the symbol table.
510 template<int size, bool big_endian>
512 Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
513 Read_symbols_data* sd)
515 if (sd->symbols == NULL)
517 gold_assert(sd->symbol_names == NULL);
521 const int sym_size = This::sym_size;
522 size_t symcount = sd->symbols_size / sym_size;
523 if (static_cast<off_t>(symcount * sym_size) != sd->symbols_size)
525 this->error(_("size of symbols is not multiple of symbol size"));
529 this->symbols_ = new Symbol*[symcount];
531 const char* sym_names =
532 reinterpret_cast<const char*>(sd->symbol_names->data());
533 symtab->add_from_relobj(this, sd->symbols->data(), symcount, sym_names,
534 sd->symbol_names_size, this->symbols_);
538 delete sd->symbol_names;
539 sd->symbol_names = NULL;
542 // Finalize the local symbols. Here we record the file offset at
543 // which they should be output, we add their names to *POOL, and we
544 // add their values to THIS->LOCAL_VALUES_. Return the symbol index.
545 // This function is always called from the main thread. The actual
546 // output of the local symbols will occur in a separate task.
548 template<int size, bool big_endian>
550 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
554 gold_assert(this->symtab_shndx_ != -1U);
555 if (this->symtab_shndx_ == 0)
557 // This object has no symbols. Weird but legal.
561 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
563 this->local_symbol_offset_ = off;
565 // Read the symbol table section header.
566 const unsigned int symtab_shndx = this->symtab_shndx_;
567 typename This::Shdr symtabshdr(this,
568 this->elf_file_.section_header(symtab_shndx));
569 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
571 // Read the local symbols.
572 const int sym_size = This::sym_size;
573 const unsigned int loccount = this->local_symbol_count_;
574 gold_assert(loccount == symtabshdr.get_sh_info());
575 off_t locsize = loccount * sym_size;
576 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
579 this->local_values_.resize(loccount);
581 // Read the symbol names.
582 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
584 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
587 const char* pnames = reinterpret_cast<const char*>(pnamesu);
589 // Loop over the local symbols.
591 const std::vector<Map_to_output>& mo(this->map_to_output());
592 unsigned int shnum = this->shnum();
593 unsigned int count = 0;
594 // Skip the first, dummy, symbol.
596 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
598 elfcpp::Sym<size, big_endian> sym(psyms);
600 Symbol_value<size>& lv(this->local_values_[i]);
602 unsigned int shndx = sym.get_st_shndx();
603 lv.set_input_shndx(shndx);
605 if (sym.get_st_type() == elfcpp::STT_SECTION)
606 lv.set_is_section_symbol();
608 if (shndx >= elfcpp::SHN_LORESERVE)
610 if (shndx == elfcpp::SHN_ABS)
611 lv.set_output_value(sym.get_st_value());
614 // FIXME: Handle SHN_XINDEX.
615 this->error(_("unknown section index %u for local symbol %u"),
617 lv.set_output_value(0);
624 this->error(_("local symbol %u section index %u out of range"),
629 Output_section* os = mo[shndx].output_section;
633 lv.set_output_value(0);
634 lv.set_no_output_symtab_entry();
638 if (mo[shndx].offset == -1)
639 lv.set_input_value(sym.get_st_value());
641 lv.set_output_value(mo[shndx].output_section->address()
643 + sym.get_st_value());
646 // Decide whether this symbol should go into the output file.
648 if (sym.get_st_type() == elfcpp::STT_SECTION)
650 lv.set_no_output_symtab_entry();
654 if (sym.get_st_name() >= strtab_size)
656 this->error(_("local symbol %u section name out of range: %u >= %u"),
657 i, sym.get_st_name(),
658 static_cast<unsigned int>(strtab_size));
659 lv.set_no_output_symtab_entry();
663 const char* name = pnames + sym.get_st_name();
664 pool->add(name, true, NULL);
665 lv.set_output_symtab_index(index);
670 this->output_local_symbol_count_ = count;
675 // Return the value of the local symbol symndx.
676 template<int size, bool big_endian>
677 typename elfcpp::Elf_types<size>::Elf_Addr
678 Sized_relobj<size, big_endian>::local_symbol_value(unsigned int symndx) const
680 gold_assert(symndx < this->local_symbol_count_);
681 gold_assert(symndx < this->local_values_.size());
682 const Symbol_value<size>& lv(this->local_values_[symndx]);
683 return lv.value(this, 0);
686 // Return the value of a local symbol defined in input section SHNDX,
687 // with value VALUE, adding addend ADDEND. IS_SECTION_SYMBOL
688 // indicates whether the symbol is a section symbol. This handles
689 // SHF_MERGE sections.
690 template<int size, bool big_endian>
691 typename elfcpp::Elf_types<size>::Elf_Addr
692 Sized_relobj<size, big_endian>::local_value(unsigned int shndx,
694 bool is_section_symbol,
695 Address addend) const
697 const std::vector<Map_to_output>& mo(this->map_to_output());
698 Output_section* os = mo[shndx].output_section;
701 gold_assert(mo[shndx].offset == -1);
703 // Do the mapping required by the output section. If this is not a
704 // section symbol, then we want to map the symbol value, and then
705 // include the addend. If this is a section symbol, then we need to
706 // include the addend to figure out where in the section we are,
707 // before we do the mapping. This will do the right thing provided
708 // the assembler is careful to only convert a relocation in a merged
709 // section to a section symbol if there is a zero addend. If the
710 // assembler does not do this, then in general we can't know what to
711 // do, because we can't distinguish the addend for the instruction
712 // format from the addend for the section offset.
714 if (is_section_symbol)
715 return os->output_address(this, shndx, value + addend);
717 return addend + os->output_address(this, shndx, value);
720 // Write out the local symbols.
722 template<int size, bool big_endian>
724 Sized_relobj<size, big_endian>::write_local_symbols(Output_file* of,
725 const Stringpool* sympool)
727 if (parameters->strip_all())
730 gold_assert(this->symtab_shndx_ != -1U);
731 if (this->symtab_shndx_ == 0)
733 // This object has no symbols. Weird but legal.
737 // Read the symbol table section header.
738 const unsigned int symtab_shndx = this->symtab_shndx_;
739 typename This::Shdr symtabshdr(this,
740 this->elf_file_.section_header(symtab_shndx));
741 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
742 const unsigned int loccount = this->local_symbol_count_;
743 gold_assert(loccount == symtabshdr.get_sh_info());
745 // Read the local symbols.
746 const int sym_size = This::sym_size;
747 off_t locsize = loccount * sym_size;
748 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
751 // Read the symbol names.
752 const unsigned int strtab_shndx = symtabshdr.get_sh_link();
754 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
757 const char* pnames = reinterpret_cast<const char*>(pnamesu);
759 // Get a view into the output file.
760 off_t output_size = this->output_local_symbol_count_ * sym_size;
761 unsigned char* oview = of->get_output_view(this->local_symbol_offset_,
764 const std::vector<Map_to_output>& mo(this->map_to_output());
766 gold_assert(this->local_values_.size() == loccount);
768 unsigned char* ov = oview;
770 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
772 elfcpp::Sym<size, big_endian> isym(psyms);
774 if (!this->local_values_[i].needs_output_symtab_entry())
777 unsigned int st_shndx = isym.get_st_shndx();
778 if (st_shndx < elfcpp::SHN_LORESERVE)
780 gold_assert(st_shndx < mo.size());
781 if (mo[st_shndx].output_section == NULL)
783 st_shndx = mo[st_shndx].output_section->out_shndx();
786 elfcpp::Sym_write<size, big_endian> osym(ov);
788 gold_assert(isym.get_st_name() < strtab_size);
789 const char* name = pnames + isym.get_st_name();
790 osym.put_st_name(sympool->get_offset(name));
791 osym.put_st_value(this->local_values_[i].value(this, 0));
792 osym.put_st_size(isym.get_st_size());
793 osym.put_st_info(isym.get_st_info());
794 osym.put_st_other(isym.get_st_other());
795 osym.put_st_shndx(st_shndx);
800 gold_assert(ov - oview == output_size);
802 of->write_output_view(this->local_symbol_offset_, output_size, oview);
805 // Set *INFO to symbolic information about the offset OFFSET in the
806 // section SHNDX. Return true if we found something, false if we
809 template<int size, bool big_endian>
811 Sized_relobj<size, big_endian>::get_symbol_location_info(
814 Symbol_location_info* info)
816 if (this->symtab_shndx_ == 0)
820 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
824 unsigned int symbol_names_shndx = this->section_link(this->symtab_shndx_);
826 const unsigned char* symbol_names_u =
827 this->section_contents(symbol_names_shndx, &names_size, false);
828 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
830 const int sym_size = This::sym_size;
831 const size_t count = symbols_size / sym_size;
833 const unsigned char* p = symbols;
834 for (size_t i = 0; i < count; ++i, p += sym_size)
836 elfcpp::Sym<size, big_endian> sym(p);
838 if (sym.get_st_type() == elfcpp::STT_FILE)
840 if (sym.get_st_name() >= names_size)
841 info->source_file = "(invalid)";
843 info->source_file = symbol_names + sym.get_st_name();
845 else if (sym.get_st_shndx() == shndx
846 && static_cast<off_t>(sym.get_st_value()) <= offset
847 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
850 if (sym.get_st_name() > names_size)
851 info->enclosing_symbol_name = "(invalid)";
853 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
861 // Input_objects methods.
863 // Add a regular relocatable object to the list. Return false if this
864 // object should be ignored.
867 Input_objects::add_object(Object* obj)
869 if (!obj->is_dynamic())
870 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
873 // See if this is a duplicate SONAME.
874 Dynobj* dynobj = static_cast<Dynobj*>(obj);
876 std::pair<Unordered_set<std::string>::iterator, bool> ins =
877 this->sonames_.insert(dynobj->soname());
880 // We have already seen a dynamic object with this soname.
884 this->dynobj_list_.push_back(dynobj);
887 Target* target = obj->target();
888 if (this->target_ == NULL)
889 this->target_ = target;
890 else if (this->target_ != target)
892 gold_error(_("%s: incompatible target"), obj->name().c_str());
896 set_parameters_size_and_endianness(target->get_size(),
897 target->is_big_endian());
902 // Relocate_info methods.
904 // Return a string describing the location of a relocation. This is
905 // only used in error messages.
907 template<int size, bool big_endian>
909 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
911 // See if we can get line-number information from debugging sections.
912 std::string filename;
913 std::string file_and_lineno; // Better than filename-only, if available.
914 for (unsigned int shndx = 0; shndx < this->object->shnum(); ++shndx)
915 if (this->object->section_name(shndx) == ".debug_line")
917 off_t debuglines_size;
918 const unsigned char* debuglines = this->object->section_contents(
919 shndx, &debuglines_size, false);
922 Dwarf_line_info line_info(debuglines, debuglines_size);
923 line_info.read_line_mappings<size, big_endian>();
924 file_and_lineno = line_info.addr2line(this->data_shndx, offset);
929 std::string ret(this->object->name());
931 Symbol_location_info info;
932 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
934 ret += " in function ";
935 // We could demangle this name before printing, but we don't
936 // bother because gcc runs linker output through a demangle
937 // filter itself. The only advantage to demangling here is if
938 // someone might call ld directly, rather than via gcc. If we
939 // did want to demangle, cplus_demangle() is in libiberty.
940 ret += info.enclosing_symbol_name;
942 filename = info.source_file;
945 if (!file_and_lineno.empty())
946 ret += file_and_lineno;
949 if (!filename.empty())
952 ret += this->object->section_name(this->data_shndx);
954 // Offsets into sections have to be positive.
955 snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
962 } // End namespace gold.
967 using namespace gold;
969 // Read an ELF file with the header and return the appropriate
970 // instance of Object.
972 template<int size, bool big_endian>
974 make_elf_sized_object(const std::string& name, Input_file* input_file,
975 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
977 int et = ehdr.get_e_type();
978 if (et == elfcpp::ET_REL)
980 Sized_relobj<size, big_endian>* obj =
981 new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
985 else if (et == elfcpp::ET_DYN)
987 Sized_dynobj<size, big_endian>* obj =
988 new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
994 gold_error(_("%s: unsupported ELF file type %d"),
1000 } // End anonymous namespace.
1005 // Read an ELF file and return the appropriate instance of Object.
1008 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
1009 const unsigned char* p, off_t bytes)
1011 if (bytes < elfcpp::EI_NIDENT)
1013 gold_error(_("%s: ELF file too short"), name.c_str());
1017 int v = p[elfcpp::EI_VERSION];
1018 if (v != elfcpp::EV_CURRENT)
1020 if (v == elfcpp::EV_NONE)
1021 gold_error(_("%s: invalid ELF version 0"), name.c_str());
1023 gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
1027 int c = p[elfcpp::EI_CLASS];
1028 if (c == elfcpp::ELFCLASSNONE)
1030 gold_error(_("%s: invalid ELF class 0"), name.c_str());
1033 else if (c != elfcpp::ELFCLASS32
1034 && c != elfcpp::ELFCLASS64)
1036 gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
1040 int d = p[elfcpp::EI_DATA];
1041 if (d == elfcpp::ELFDATANONE)
1043 gold_error(_("%s: invalid ELF data encoding"), name.c_str());
1046 else if (d != elfcpp::ELFDATA2LSB
1047 && d != elfcpp::ELFDATA2MSB)
1049 gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
1053 bool big_endian = d == elfcpp::ELFDATA2MSB;
1055 if (c == elfcpp::ELFCLASS32)
1057 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1059 gold_error(_("%s: ELF file too short"), name.c_str());
1064 #ifdef HAVE_TARGET_32_BIG
1065 elfcpp::Ehdr<32, true> ehdr(p);
1066 return make_elf_sized_object<32, true>(name, input_file,
1069 gold_error(_("%s: not configured to support "
1070 "32-bit big-endian object"),
1077 #ifdef HAVE_TARGET_32_LITTLE
1078 elfcpp::Ehdr<32, false> ehdr(p);
1079 return make_elf_sized_object<32, false>(name, input_file,
1082 gold_error(_("%s: not configured to support "
1083 "32-bit little-endian object"),
1091 if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
1093 gold_error(_("%s: ELF file too short"), name.c_str());
1098 #ifdef HAVE_TARGET_64_BIG
1099 elfcpp::Ehdr<64, true> ehdr(p);
1100 return make_elf_sized_object<64, true>(name, input_file,
1103 gold_error(_("%s: not configured to support "
1104 "64-bit big-endian object"),
1111 #ifdef HAVE_TARGET_64_LITTLE
1112 elfcpp::Ehdr<64, false> ehdr(p);
1113 return make_elf_sized_object<64, false>(name, input_file,
1116 gold_error(_("%s: not configured to support "
1117 "64-bit little-endian object"),
1125 // Instantiate the templates we need. We could use the configure
1126 // script to restrict this to only the ones for implemented targets.
1128 #ifdef HAVE_TARGET_32_LITTLE
1130 class Sized_relobj<32, false>;
1133 #ifdef HAVE_TARGET_32_BIG
1135 class Sized_relobj<32, true>;
1138 #ifdef HAVE_TARGET_64_LITTLE
1140 class Sized_relobj<64, false>;
1143 #ifdef HAVE_TARGET_64_BIG
1145 class Sized_relobj<64, true>;
1148 #ifdef HAVE_TARGET_32_LITTLE
1150 struct Relocate_info<32, false>;
1153 #ifdef HAVE_TARGET_32_BIG
1155 struct Relocate_info<32, true>;
1158 #ifdef HAVE_TARGET_64_LITTLE
1160 struct Relocate_info<64, false>;
1163 #ifdef HAVE_TARGET_64_BIG
1165 struct Relocate_info<64, true>;
1168 } // End namespace gold.