1 // object.cc -- support for an object file for linking in gold
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 "libiberty.h"
32 #include "target-select.h"
33 #include "dwarf_reader.h"
42 #include "compressed_output.h"
43 #include "incremental.h"
48 // Struct Read_symbols_data.
50 // Destroy any remaining File_view objects.
52 Read_symbols_data::~Read_symbols_data()
54 if (this->section_headers != NULL)
55 delete this->section_headers;
56 if (this->section_names != NULL)
57 delete this->section_names;
58 if (this->symbols != NULL)
60 if (this->symbol_names != NULL)
61 delete this->symbol_names;
62 if (this->versym != NULL)
64 if (this->verdef != NULL)
66 if (this->verneed != NULL)
72 // Initialize the symtab_xindex_ array. Find the SHT_SYMTAB_SHNDX
73 // section and read it in. SYMTAB_SHNDX is the index of the symbol
74 // table we care about.
76 template<int size, bool big_endian>
78 Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
80 if (!this->symtab_xindex_.empty())
83 gold_assert(symtab_shndx != 0);
85 // Look through the sections in reverse order, on the theory that it
86 // is more likely to be near the end than the beginning.
87 unsigned int i = object->shnum();
91 if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
92 && this->adjust_shndx(object->section_link(i)) == symtab_shndx)
94 this->read_symtab_xindex<size, big_endian>(object, i, NULL);
99 object->error(_("missing SHT_SYMTAB_SHNDX section"));
102 // Read in the symtab_xindex_ array, given the section index of the
103 // SHT_SYMTAB_SHNDX section. If PSHDRS is not NULL, it points at the
106 template<int size, bool big_endian>
108 Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
109 const unsigned char* pshdrs)
111 section_size_type bytecount;
112 const unsigned char* contents;
114 contents = object->section_contents(xindex_shndx, &bytecount, false);
117 const unsigned char* p = (pshdrs
119 * elfcpp::Elf_sizes<size>::shdr_size));
120 typename elfcpp::Shdr<size, big_endian> shdr(p);
121 bytecount = convert_to_section_size_type(shdr.get_sh_size());
122 contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
125 gold_assert(this->symtab_xindex_.empty());
126 this->symtab_xindex_.reserve(bytecount / 4);
127 for (section_size_type i = 0; i < bytecount; i += 4)
129 unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
130 // We preadjust the section indexes we save.
131 this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
135 // Symbol symndx has a section of SHN_XINDEX; return the real section
139 Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
141 if (symndx >= this->symtab_xindex_.size())
143 object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
145 return elfcpp::SHN_UNDEF;
147 unsigned int shndx = this->symtab_xindex_[symndx];
148 if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
150 object->error(_("extended index for symbol %u out of range: %u"),
152 return elfcpp::SHN_UNDEF;
159 // Report an error for this object file. This is used by the
160 // elfcpp::Elf_file interface, and also called by the Object code
164 Object::error(const char* format, ...) const
167 va_start(args, format);
169 if (vasprintf(&buf, format, args) < 0)
172 gold_error(_("%s: %s"), this->name().c_str(), buf);
176 // Return a view of the contents of a section.
179 Object::section_contents(unsigned int shndx, section_size_type* plen,
182 Location loc(this->do_section_contents(shndx));
183 *plen = convert_to_section_size_type(loc.data_size);
186 static const unsigned char empty[1] = { '\0' };
189 return this->get_view(loc.file_offset, *plen, true, cache);
192 // Read the section data into SD. This is code common to Sized_relobj_file
193 // and Sized_dynobj, so we put it into Object.
195 template<int size, bool big_endian>
197 Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
198 Read_symbols_data* sd)
200 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
202 // Read the section headers.
203 const off_t shoff = elf_file->shoff();
204 const unsigned int shnum = this->shnum();
205 sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
208 // Read the section names.
209 const unsigned char* pshdrs = sd->section_headers->data();
210 const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
211 typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
213 if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
214 this->error(_("section name section has wrong type: %u"),
215 static_cast<unsigned int>(shdrnames.get_sh_type()));
217 sd->section_names_size =
218 convert_to_section_size_type(shdrnames.get_sh_size());
219 sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
220 sd->section_names_size, false,
224 // If NAME is the name of a special .gnu.warning section, arrange for
225 // the warning to be issued. SHNDX is the section index. Return
226 // whether it is a warning section.
229 Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
230 Symbol_table* symtab)
232 const char warn_prefix[] = ".gnu.warning.";
233 const int warn_prefix_len = sizeof warn_prefix - 1;
234 if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
236 // Read the section contents to get the warning text. It would
237 // be nicer if we only did this if we have to actually issue a
238 // warning. Unfortunately, warnings are issued as we relocate
239 // sections. That means that we can not lock the object then,
240 // as we might try to issue the same warning multiple times
242 section_size_type len;
243 const unsigned char* contents = this->section_contents(shndx, &len,
247 const char* warning = name + warn_prefix_len;
248 contents = reinterpret_cast<const unsigned char*>(warning);
249 len = strlen(warning);
251 std::string warning(reinterpret_cast<const char*>(contents), len);
252 symtab->add_warning(name + warn_prefix_len, this, warning);
258 // If NAME is the name of the special section which indicates that
259 // this object was compiled with -fsplit-stack, mark it accordingly.
262 Object::handle_split_stack_section(const char* name)
264 if (strcmp(name, ".note.GNU-split-stack") == 0)
266 this->uses_split_stack_ = true;
269 if (strcmp(name, ".note.GNU-no-split-stack") == 0)
271 this->has_no_split_stack_ = true;
279 // To copy the symbols data read from the file to a local data structure.
280 // This function is called from do_layout only while doing garbage
284 Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
285 unsigned int section_header_size)
287 gc_sd->section_headers_data =
288 new unsigned char[(section_header_size)];
289 memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
290 section_header_size);
291 gc_sd->section_names_data =
292 new unsigned char[sd->section_names_size];
293 memcpy(gc_sd->section_names_data, sd->section_names->data(),
294 sd->section_names_size);
295 gc_sd->section_names_size = sd->section_names_size;
296 if (sd->symbols != NULL)
298 gc_sd->symbols_data =
299 new unsigned char[sd->symbols_size];
300 memcpy(gc_sd->symbols_data, sd->symbols->data(),
305 gc_sd->symbols_data = NULL;
307 gc_sd->symbols_size = sd->symbols_size;
308 gc_sd->external_symbols_offset = sd->external_symbols_offset;
309 if (sd->symbol_names != NULL)
311 gc_sd->symbol_names_data =
312 new unsigned char[sd->symbol_names_size];
313 memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
314 sd->symbol_names_size);
318 gc_sd->symbol_names_data = NULL;
320 gc_sd->symbol_names_size = sd->symbol_names_size;
323 // This function determines if a particular section name must be included
324 // in the link. This is used during garbage collection to determine the
325 // roots of the worklist.
328 Relobj::is_section_name_included(const char* name)
330 if (is_prefix_of(".ctors", name)
331 || is_prefix_of(".dtors", name)
332 || is_prefix_of(".note", name)
333 || is_prefix_of(".init", name)
334 || is_prefix_of(".fini", name)
335 || is_prefix_of(".gcc_except_table", name)
336 || is_prefix_of(".jcr", name)
337 || is_prefix_of(".preinit_array", name)
338 || (is_prefix_of(".text", name)
339 && strstr(name, "personality"))
340 || (is_prefix_of(".data", name)
341 && strstr(name, "personality"))
342 || (is_prefix_of(".gnu.linkonce.d", name)
343 && strstr(name, "personality")))
350 // Finalize the incremental relocation information. Allocates a block
351 // of relocation entries for each symbol, and sets the reloc_bases_
352 // array to point to the first entry in each block. If CLEAR_COUNTS
353 // is TRUE, also clear the per-symbol relocation counters.
356 Relobj::finalize_incremental_relocs(Layout* layout, bool clear_counts)
358 unsigned int nsyms = this->get_global_symbols()->size();
359 this->reloc_bases_ = new unsigned int[nsyms];
361 gold_assert(this->reloc_bases_ != NULL);
362 gold_assert(layout->incremental_inputs() != NULL);
364 unsigned int rindex = layout->incremental_inputs()->get_reloc_count();
365 for (unsigned int i = 0; i < nsyms; ++i)
367 this->reloc_bases_[i] = rindex;
368 rindex += this->reloc_counts_[i];
370 this->reloc_counts_[i] = 0;
372 layout->incremental_inputs()->set_reloc_count(rindex);
375 // Class Sized_relobj.
377 // Iterate over local symbols, calling a visitor class V for each GOT offset
378 // associated with a local symbol.
380 template<int size, bool big_endian>
382 Sized_relobj<size, big_endian>::do_for_all_local_got_entries(
383 Got_offset_list::Visitor* v) const
385 unsigned int nsyms = this->local_symbol_count();
386 for (unsigned int i = 0; i < nsyms; i++)
388 Local_got_offsets::const_iterator p = this->local_got_offsets_.find(i);
389 if (p != this->local_got_offsets_.end())
391 const Got_offset_list* got_offsets = p->second;
392 got_offsets->for_all_got_offsets(v);
397 // Class Sized_relobj_file.
399 template<int size, bool big_endian>
400 Sized_relobj_file<size, big_endian>::Sized_relobj_file(
401 const std::string& name,
402 Input_file* input_file,
404 const elfcpp::Ehdr<size, big_endian>& ehdr)
405 : Sized_relobj<size, big_endian>(name, input_file, offset),
406 elf_file_(this, ehdr),
408 local_symbol_count_(0),
409 output_local_symbol_count_(0),
410 output_local_dynsym_count_(0),
413 local_symbol_offset_(0),
414 local_dynsym_offset_(0),
416 local_plt_offsets_(),
417 kept_comdat_sections_(),
418 has_eh_frame_(false),
419 discarded_eh_frame_shndx_(-1U),
421 deferred_layout_relocs_(),
422 compressed_sections_()
426 template<int size, bool big_endian>
427 Sized_relobj_file<size, big_endian>::~Sized_relobj_file()
431 // Set up an object file based on the file header. This sets up the
432 // section information.
434 template<int size, bool big_endian>
436 Sized_relobj_file<size, big_endian>::do_setup()
438 const unsigned int shnum = this->elf_file_.shnum();
439 this->set_shnum(shnum);
442 // Find the SHT_SYMTAB section, given the section headers. The ELF
443 // standard says that maybe in the future there can be more than one
444 // SHT_SYMTAB section. Until somebody figures out how that could
445 // work, we assume there is only one.
447 template<int size, bool big_endian>
449 Sized_relobj_file<size, big_endian>::find_symtab(const unsigned char* pshdrs)
451 const unsigned int shnum = this->shnum();
452 this->symtab_shndx_ = 0;
455 // Look through the sections in reverse order, since gas tends
456 // to put the symbol table at the end.
457 const unsigned char* p = pshdrs + shnum * This::shdr_size;
458 unsigned int i = shnum;
459 unsigned int xindex_shndx = 0;
460 unsigned int xindex_link = 0;
464 p -= This::shdr_size;
465 typename This::Shdr shdr(p);
466 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
468 this->symtab_shndx_ = i;
469 if (xindex_shndx > 0 && xindex_link == i)
472 new Xindex(this->elf_file_.large_shndx_offset());
473 xindex->read_symtab_xindex<size, big_endian>(this,
476 this->set_xindex(xindex);
481 // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
482 // one. This will work if it follows the SHT_SYMTAB
484 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
487 xindex_link = this->adjust_shndx(shdr.get_sh_link());
493 // Return the Xindex structure to use for object with lots of
496 template<int size, bool big_endian>
498 Sized_relobj_file<size, big_endian>::do_initialize_xindex()
500 gold_assert(this->symtab_shndx_ != -1U);
501 Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
502 xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
506 // Return whether SHDR has the right type and flags to be a GNU
507 // .eh_frame section.
509 template<int size, bool big_endian>
511 Sized_relobj_file<size, big_endian>::check_eh_frame_flags(
512 const elfcpp::Shdr<size, big_endian>* shdr) const
514 elfcpp::Elf_Word sh_type = shdr->get_sh_type();
515 return ((sh_type == elfcpp::SHT_PROGBITS
516 || sh_type == elfcpp::SHT_X86_64_UNWIND)
517 && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
520 // Return whether there is a GNU .eh_frame section, given the section
521 // headers and the section names.
523 template<int size, bool big_endian>
525 Sized_relobj_file<size, big_endian>::find_eh_frame(
526 const unsigned char* pshdrs,
528 section_size_type names_size) const
530 const unsigned int shnum = this->shnum();
531 const unsigned char* p = pshdrs + This::shdr_size;
532 for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
534 typename This::Shdr shdr(p);
535 if (this->check_eh_frame_flags(&shdr))
537 if (shdr.get_sh_name() >= names_size)
539 this->error(_("bad section name offset for section %u: %lu"),
540 i, static_cast<unsigned long>(shdr.get_sh_name()));
544 const char* name = names + shdr.get_sh_name();
545 if (strcmp(name, ".eh_frame") == 0)
552 // Build a table for any compressed debug sections, mapping each section index
553 // to the uncompressed size.
555 template<int size, bool big_endian>
556 Compressed_section_map*
557 build_compressed_section_map(
558 const unsigned char* pshdrs,
561 section_size_type names_size,
562 Sized_relobj_file<size, big_endian>* obj)
564 Compressed_section_map* uncompressed_sizes = new Compressed_section_map();
565 const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
566 const unsigned char* p = pshdrs + shdr_size;
567 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
569 typename elfcpp::Shdr<size, big_endian> shdr(p);
570 if (shdr.get_sh_type() == elfcpp::SHT_PROGBITS
571 && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
573 if (shdr.get_sh_name() >= names_size)
575 obj->error(_("bad section name offset for section %u: %lu"),
576 i, static_cast<unsigned long>(shdr.get_sh_name()));
580 const char* name = names + shdr.get_sh_name();
581 if (is_compressed_debug_section(name))
583 section_size_type len;
584 const unsigned char* contents =
585 obj->section_contents(i, &len, false);
586 uint64_t uncompressed_size = get_uncompressed_size(contents, len);
587 if (uncompressed_size != -1ULL)
588 (*uncompressed_sizes)[i] =
589 convert_to_section_size_type(uncompressed_size);
593 return uncompressed_sizes;
596 // Read the sections and symbols from an object file.
598 template<int size, bool big_endian>
600 Sized_relobj_file<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
602 this->read_section_data(&this->elf_file_, sd);
604 const unsigned char* const pshdrs = sd->section_headers->data();
606 this->find_symtab(pshdrs);
608 const unsigned char* namesu = sd->section_names->data();
609 const char* names = reinterpret_cast<const char*>(namesu);
610 if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL)
612 if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
613 this->has_eh_frame_ = true;
615 if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL)
616 this->compressed_sections_ =
617 build_compressed_section_map(pshdrs, this->shnum(), names,
618 sd->section_names_size, this);
621 sd->symbols_size = 0;
622 sd->external_symbols_offset = 0;
623 sd->symbol_names = NULL;
624 sd->symbol_names_size = 0;
626 if (this->symtab_shndx_ == 0)
628 // No symbol table. Weird but legal.
632 // Get the symbol table section header.
633 typename This::Shdr symtabshdr(pshdrs
634 + this->symtab_shndx_ * This::shdr_size);
635 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
637 // If this object has a .eh_frame section, we need all the symbols.
638 // Otherwise we only need the external symbols. While it would be
639 // simpler to just always read all the symbols, I've seen object
640 // files with well over 2000 local symbols, which for a 64-bit
641 // object file format is over 5 pages that we don't need to read
644 const int sym_size = This::sym_size;
645 const unsigned int loccount = symtabshdr.get_sh_info();
646 this->local_symbol_count_ = loccount;
647 this->local_values_.resize(loccount);
648 section_offset_type locsize = loccount * sym_size;
649 off_t dataoff = symtabshdr.get_sh_offset();
650 section_size_type datasize =
651 convert_to_section_size_type(symtabshdr.get_sh_size());
652 off_t extoff = dataoff + locsize;
653 section_size_type extsize = datasize - locsize;
655 off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
656 section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
660 // No external symbols. Also weird but also legal.
664 File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
666 // Read the section header for the symbol names.
667 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
668 if (strtab_shndx >= this->shnum())
670 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
673 typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
674 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
676 this->error(_("symbol table name section has wrong type: %u"),
677 static_cast<unsigned int>(strtabshdr.get_sh_type()));
681 // Read the symbol names.
682 File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
683 strtabshdr.get_sh_size(),
686 sd->symbols = fvsymtab;
687 sd->symbols_size = readsize;
688 sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
689 sd->symbol_names = fvstrtab;
690 sd->symbol_names_size =
691 convert_to_section_size_type(strtabshdr.get_sh_size());
694 // Return the section index of symbol SYM. Set *VALUE to its value in
695 // the object file. Set *IS_ORDINARY if this is an ordinary section
696 // index, not a special code between SHN_LORESERVE and SHN_HIRESERVE.
697 // Note that for a symbol which is not defined in this object file,
698 // this will set *VALUE to 0 and return SHN_UNDEF; it will not return
699 // the final value of the symbol in the link.
701 template<int size, bool big_endian>
703 Sized_relobj_file<size, big_endian>::symbol_section_and_value(unsigned int sym,
707 section_size_type symbols_size;
708 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
712 const size_t count = symbols_size / This::sym_size;
713 gold_assert(sym < count);
715 elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
716 *value = elfsym.get_st_value();
718 return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
721 // Return whether to include a section group in the link. LAYOUT is
722 // used to keep track of which section groups we have already seen.
723 // INDEX is the index of the section group and SHDR is the section
724 // header. If we do not want to include this group, we set bits in
725 // OMIT for each section which should be discarded.
727 template<int size, bool big_endian>
729 Sized_relobj_file<size, big_endian>::include_section_group(
730 Symbol_table* symtab,
734 const unsigned char* shdrs,
735 const char* section_names,
736 section_size_type section_names_size,
737 std::vector<bool>* omit)
739 // Read the section contents.
740 typename This::Shdr shdr(shdrs + index * This::shdr_size);
741 const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
742 shdr.get_sh_size(), true, false);
743 const elfcpp::Elf_Word* pword =
744 reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
746 // The first word contains flags. We only care about COMDAT section
747 // groups. Other section groups are always included in the link
748 // just like ordinary sections.
749 elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
751 // Look up the group signature, which is the name of a symbol. ELF
752 // uses a symbol name because some group signatures are long, and
753 // the name is generally already in the symbol table, so it makes
754 // sense to put the long string just once in .strtab rather than in
755 // both .strtab and .shstrtab.
757 // Get the appropriate symbol table header (this will normally be
758 // the single SHT_SYMTAB section, but in principle it need not be).
759 const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
760 typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
762 // Read the symbol table entry.
763 unsigned int symndx = shdr.get_sh_info();
764 if (symndx >= symshdr.get_sh_size() / This::sym_size)
766 this->error(_("section group %u info %u out of range"),
770 off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
771 const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
773 elfcpp::Sym<size, big_endian> sym(psym);
775 // Read the symbol table names.
776 section_size_type symnamelen;
777 const unsigned char* psymnamesu;
778 psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
780 const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
782 // Get the section group signature.
783 if (sym.get_st_name() >= symnamelen)
785 this->error(_("symbol %u name offset %u out of range"),
786 symndx, sym.get_st_name());
790 std::string signature(psymnames + sym.get_st_name());
792 // It seems that some versions of gas will create a section group
793 // associated with a section symbol, and then fail to give a name to
794 // the section symbol. In such a case, use the name of the section.
795 if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
798 unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
801 if (!is_ordinary || sym_shndx >= this->shnum())
803 this->error(_("symbol %u invalid section index %u"),
807 typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
808 if (member_shdr.get_sh_name() < section_names_size)
809 signature = section_names + member_shdr.get_sh_name();
812 // Record this section group in the layout, and see whether we've already
813 // seen one with the same signature.
816 Kept_section* kept_section = NULL;
818 if ((flags & elfcpp::GRP_COMDAT) == 0)
820 include_group = true;
825 include_group = layout->find_or_add_kept_section(signature,
827 true, &kept_section);
831 if (is_comdat && include_group)
833 Incremental_inputs* incremental_inputs = layout->incremental_inputs();
834 if (incremental_inputs != NULL)
835 incremental_inputs->report_comdat_group(this, signature.c_str());
838 size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
840 std::vector<unsigned int> shndxes;
841 bool relocate_group = include_group && parameters->options().relocatable();
843 shndxes.reserve(count - 1);
845 for (size_t i = 1; i < count; ++i)
847 elfcpp::Elf_Word shndx =
848 this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
851 shndxes.push_back(shndx);
853 if (shndx >= this->shnum())
855 this->error(_("section %u in section group %u out of range"),
860 // Check for an earlier section number, since we're going to get
861 // it wrong--we may have already decided to include the section.
863 this->error(_("invalid section group %u refers to earlier section %u"),
866 // Get the name of the member section.
867 typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size);
868 if (member_shdr.get_sh_name() >= section_names_size)
870 // This is an error, but it will be diagnosed eventually
871 // in do_layout, so we don't need to do anything here but
875 std::string mname(section_names + member_shdr.get_sh_name());
880 kept_section->add_comdat_section(mname, shndx,
881 member_shdr.get_sh_size());
885 (*omit)[shndx] = true;
889 Relobj* kept_object = kept_section->object();
890 if (kept_section->is_comdat())
892 // Find the corresponding kept section, and store
893 // that info in the discarded section table.
894 unsigned int kept_shndx;
896 if (kept_section->find_comdat_section(mname, &kept_shndx,
899 // We don't keep a mapping for this section if
900 // it has a different size. The mapping is only
901 // used for relocation processing, and we don't
902 // want to treat the sections as similar if the
903 // sizes are different. Checking the section
904 // size is the approach used by the GNU linker.
905 if (kept_size == member_shdr.get_sh_size())
906 this->set_kept_comdat_section(shndx, kept_object,
912 // The existing section is a linkonce section. Add
913 // a mapping if there is exactly one section in the
914 // group (which is true when COUNT == 2) and if it
917 && (kept_section->linkonce_size()
918 == member_shdr.get_sh_size()))
919 this->set_kept_comdat_section(shndx, kept_object,
920 kept_section->shndx());
927 layout->layout_group(symtab, this, index, name, signature.c_str(),
928 shdr, flags, &shndxes);
930 return include_group;
933 // Whether to include a linkonce section in the link. NAME is the
934 // name of the section and SHDR is the section header.
936 // Linkonce sections are a GNU extension implemented in the original
937 // GNU linker before section groups were defined. The semantics are
938 // that we only include one linkonce section with a given name. The
939 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
940 // where T is the type of section and SYMNAME is the name of a symbol.
941 // In an attempt to make linkonce sections interact well with section
942 // groups, we try to identify SYMNAME and use it like a section group
943 // signature. We want to block section groups with that signature,
944 // but not other linkonce sections with that signature. We also use
945 // the full name of the linkonce section as a normal section group
948 template<int size, bool big_endian>
950 Sized_relobj_file<size, big_endian>::include_linkonce_section(
954 const elfcpp::Shdr<size, big_endian>& shdr)
956 typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
957 // In general the symbol name we want will be the string following
958 // the last '.'. However, we have to handle the case of
959 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
960 // some versions of gcc. So we use a heuristic: if the name starts
961 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
962 // we look for the last '.'. We can't always simply skip
963 // ".gnu.linkonce.X", because we have to deal with cases like
964 // ".gnu.linkonce.d.rel.ro.local".
965 const char* const linkonce_t = ".gnu.linkonce.t.";
967 if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
968 symname = name + strlen(linkonce_t);
970 symname = strrchr(name, '.') + 1;
971 std::string sig1(symname);
972 std::string sig2(name);
975 bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
977 bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
982 // We are not including this section because we already saw the
983 // name of the section as a signature. This normally implies
984 // that the kept section is another linkonce section. If it is
985 // the same size, record it as the section which corresponds to
987 if (kept2->object() != NULL
988 && !kept2->is_comdat()
989 && kept2->linkonce_size() == sh_size)
990 this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
994 // The section is being discarded on the basis of its symbol
995 // name. This means that the corresponding kept section was
996 // part of a comdat group, and it will be difficult to identify
997 // the specific section within that group that corresponds to
998 // this linkonce section. We'll handle the simple case where
999 // the group has only one member section. Otherwise, it's not
1000 // worth the effort.
1001 unsigned int kept_shndx;
1003 if (kept1->object() != NULL
1004 && kept1->is_comdat()
1005 && kept1->find_single_comdat_section(&kept_shndx, &kept_size)
1006 && kept_size == sh_size)
1007 this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
1011 kept1->set_linkonce_size(sh_size);
1012 kept2->set_linkonce_size(sh_size);
1015 return include1 && include2;
1018 // Layout an input section.
1020 template<int size, bool big_endian>
1022 Sized_relobj_file<size, big_endian>::layout_section(
1026 const typename This::Shdr& shdr,
1027 unsigned int reloc_shndx,
1028 unsigned int reloc_type)
1031 Output_section* os = layout->layout(this, shndx, name, shdr,
1032 reloc_shndx, reloc_type, &offset);
1034 this->output_sections()[shndx] = os;
1036 this->section_offsets()[shndx] = invalid_address;
1038 this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1040 // If this section requires special handling, and if there are
1041 // relocs that apply to it, then we must do the special handling
1042 // before we apply the relocs.
1043 if (offset == -1 && reloc_shndx != 0)
1044 this->set_relocs_must_follow_section_writes();
1047 // Layout an input .eh_frame section.
1049 template<int size, bool big_endian>
1051 Sized_relobj_file<size, big_endian>::layout_eh_frame_section(
1053 const unsigned char* symbols_data,
1054 section_size_type symbols_size,
1055 const unsigned char* symbol_names_data,
1056 section_size_type symbol_names_size,
1058 const typename This::Shdr& shdr,
1059 unsigned int reloc_shndx,
1060 unsigned int reloc_type)
1062 gold_assert(this->has_eh_frame_);
1065 Output_section* os = layout->layout_eh_frame(this,
1075 this->output_sections()[shndx] = os;
1076 if (os == NULL || offset == -1)
1078 // An object can contain at most one section holding exception
1079 // frame information.
1080 gold_assert(this->discarded_eh_frame_shndx_ == -1U);
1081 this->discarded_eh_frame_shndx_ = shndx;
1082 this->section_offsets()[shndx] = invalid_address;
1085 this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1087 // If this section requires special handling, and if there are
1088 // relocs that aply to it, then we must do the special handling
1089 // before we apply the relocs.
1090 if (os != NULL && offset == -1 && reloc_shndx != 0)
1091 this->set_relocs_must_follow_section_writes();
1094 // Lay out the input sections. We walk through the sections and check
1095 // whether they should be included in the link. If they should, we
1096 // pass them to the Layout object, which will return an output section
1098 // During garbage collection (--gc-sections) and identical code folding
1099 // (--icf), this function is called twice. When it is called the first
1100 // time, it is for setting up some sections as roots to a work-list for
1101 // --gc-sections and to do comdat processing. Actual layout happens the
1102 // second time around after all the relevant sections have been determined.
1103 // The first time, is_worklist_ready or is_icf_ready is false. It is then
1104 // set to true after the garbage collection worklist or identical code
1105 // folding is processed and the relevant sections to be kept are
1106 // determined. Then, this function is called again to layout the sections.
1108 template<int size, bool big_endian>
1110 Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
1112 Read_symbols_data* sd)
1114 const unsigned int shnum = this->shnum();
1115 bool is_gc_pass_one = ((parameters->options().gc_sections()
1116 && !symtab->gc()->is_worklist_ready())
1117 || (parameters->options().icf_enabled()
1118 && !symtab->icf()->is_icf_ready()));
1120 bool is_gc_pass_two = ((parameters->options().gc_sections()
1121 && symtab->gc()->is_worklist_ready())
1122 || (parameters->options().icf_enabled()
1123 && symtab->icf()->is_icf_ready()));
1125 bool is_gc_or_icf = (parameters->options().gc_sections()
1126 || parameters->options().icf_enabled());
1128 // Both is_gc_pass_one and is_gc_pass_two should not be true.
1129 gold_assert(!(is_gc_pass_one && is_gc_pass_two));
1133 Symbols_data* gc_sd = NULL;
1136 // During garbage collection save the symbols data to use it when
1137 // re-entering this function.
1138 gc_sd = new Symbols_data;
1139 this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
1140 this->set_symbols_data(gc_sd);
1142 else if (is_gc_pass_two)
1144 gc_sd = this->get_symbols_data();
1147 const unsigned char* section_headers_data = NULL;
1148 section_size_type section_names_size;
1149 const unsigned char* symbols_data = NULL;
1150 section_size_type symbols_size;
1151 section_offset_type external_symbols_offset;
1152 const unsigned char* symbol_names_data = NULL;
1153 section_size_type symbol_names_size;
1157 section_headers_data = gc_sd->section_headers_data;
1158 section_names_size = gc_sd->section_names_size;
1159 symbols_data = gc_sd->symbols_data;
1160 symbols_size = gc_sd->symbols_size;
1161 external_symbols_offset = gc_sd->external_symbols_offset;
1162 symbol_names_data = gc_sd->symbol_names_data;
1163 symbol_names_size = gc_sd->symbol_names_size;
1167 section_headers_data = sd->section_headers->data();
1168 section_names_size = sd->section_names_size;
1169 if (sd->symbols != NULL)
1170 symbols_data = sd->symbols->data();
1171 symbols_size = sd->symbols_size;
1172 external_symbols_offset = sd->external_symbols_offset;
1173 if (sd->symbol_names != NULL)
1174 symbol_names_data = sd->symbol_names->data();
1175 symbol_names_size = sd->symbol_names_size;
1178 // Get the section headers.
1179 const unsigned char* shdrs = section_headers_data;
1180 const unsigned char* pshdrs;
1182 // Get the section names.
1183 const unsigned char* pnamesu = (is_gc_or_icf)
1184 ? gc_sd->section_names_data
1185 : sd->section_names->data();
1187 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1189 // If any input files have been claimed by plugins, we need to defer
1190 // actual layout until the replacement files have arrived.
1191 const bool should_defer_layout =
1192 (parameters->options().has_plugins()
1193 && parameters->options().plugins()->should_defer_layout());
1194 unsigned int num_sections_to_defer = 0;
1196 // For each section, record the index of the reloc section if any.
1197 // Use 0 to mean that there is no reloc section, -1U to mean that
1198 // there is more than one.
1199 std::vector<unsigned int> reloc_shndx(shnum, 0);
1200 std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
1201 // Skip the first, dummy, section.
1202 pshdrs = shdrs + This::shdr_size;
1203 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1205 typename This::Shdr shdr(pshdrs);
1207 // Count the number of sections whose layout will be deferred.
1208 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1209 ++num_sections_to_defer;
1211 unsigned int sh_type = shdr.get_sh_type();
1212 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
1214 unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
1215 if (target_shndx == 0 || target_shndx >= shnum)
1217 this->error(_("relocation section %u has bad info %u"),
1222 if (reloc_shndx[target_shndx] != 0)
1223 reloc_shndx[target_shndx] = -1U;
1226 reloc_shndx[target_shndx] = i;
1227 reloc_type[target_shndx] = sh_type;
1232 Output_sections& out_sections(this->output_sections());
1233 std::vector<Address>& out_section_offsets(this->section_offsets());
1235 if (!is_gc_pass_two)
1237 out_sections.resize(shnum);
1238 out_section_offsets.resize(shnum);
1241 // If we are only linking for symbols, then there is nothing else to
1243 if (this->input_file()->just_symbols())
1245 if (!is_gc_pass_two)
1247 delete sd->section_headers;
1248 sd->section_headers = NULL;
1249 delete sd->section_names;
1250 sd->section_names = NULL;
1255 if (num_sections_to_defer > 0)
1257 parameters->options().plugins()->add_deferred_layout_object(this);
1258 this->deferred_layout_.reserve(num_sections_to_defer);
1261 // Whether we've seen a .note.GNU-stack section.
1262 bool seen_gnu_stack = false;
1263 // The flags of a .note.GNU-stack section.
1264 uint64_t gnu_stack_flags = 0;
1266 // Keep track of which sections to omit.
1267 std::vector<bool> omit(shnum, false);
1269 // Keep track of reloc sections when emitting relocations.
1270 const bool relocatable = parameters->options().relocatable();
1271 const bool emit_relocs = (relocatable
1272 || parameters->options().emit_relocs());
1273 std::vector<unsigned int> reloc_sections;
1275 // Keep track of .eh_frame sections.
1276 std::vector<unsigned int> eh_frame_sections;
1278 // Skip the first, dummy, section.
1279 pshdrs = shdrs + This::shdr_size;
1280 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1282 typename This::Shdr shdr(pshdrs);
1284 if (shdr.get_sh_name() >= section_names_size)
1286 this->error(_("bad section name offset for section %u: %lu"),
1287 i, static_cast<unsigned long>(shdr.get_sh_name()));
1291 const char* name = pnames + shdr.get_sh_name();
1293 if (!is_gc_pass_two)
1295 if (this->handle_gnu_warning_section(name, i, symtab))
1297 if (!relocatable && !parameters->options().shared())
1301 // The .note.GNU-stack section is special. It gives the
1302 // protection flags that this object file requires for the stack
1304 if (strcmp(name, ".note.GNU-stack") == 0)
1306 seen_gnu_stack = true;
1307 gnu_stack_flags |= shdr.get_sh_flags();
1311 // The .note.GNU-split-stack section is also special. It
1312 // indicates that the object was compiled with
1314 if (this->handle_split_stack_section(name))
1316 if (!relocatable && !parameters->options().shared())
1320 // Skip attributes section.
1321 if (parameters->target().is_attributes_section(name))
1326 bool discard = omit[i];
1329 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
1331 if (!this->include_section_group(symtab, layout, i, name,
1337 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
1338 && Layout::is_linkonce(name))
1340 if (!this->include_linkonce_section(layout, i, name, shdr))
1345 // Add the section to the incremental inputs layout.
1346 Incremental_inputs* incremental_inputs = layout->incremental_inputs();
1347 if (incremental_inputs != NULL
1349 && (shdr.get_sh_type() == elfcpp::SHT_PROGBITS
1350 || shdr.get_sh_type() == elfcpp::SHT_NOBITS
1351 || shdr.get_sh_type() == elfcpp::SHT_NOTE))
1353 off_t sh_size = shdr.get_sh_size();
1354 section_size_type uncompressed_size;
1355 if (this->section_is_compressed(i, &uncompressed_size))
1356 sh_size = uncompressed_size;
1357 incremental_inputs->report_input_section(this, i, name, sh_size);
1362 // Do not include this section in the link.
1363 out_sections[i] = NULL;
1364 out_section_offsets[i] = invalid_address;
1369 if (is_gc_pass_one && parameters->options().gc_sections())
1371 if (this->is_section_name_included(name)
1372 || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1373 || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
1375 symtab->gc()->worklist().push(Section_id(this, i));
1377 // If the section name XXX can be represented as a C identifier
1378 // it cannot be discarded if there are references to
1379 // __start_XXX and __stop_XXX symbols. These need to be
1380 // specially handled.
1381 if (is_cident(name))
1383 symtab->gc()->add_cident_section(name, Section_id(this, i));
1387 // When doing a relocatable link we are going to copy input
1388 // reloc sections into the output. We only want to copy the
1389 // ones associated with sections which are not being discarded.
1390 // However, we don't know that yet for all sections. So save
1391 // reloc sections and process them later. Garbage collection is
1392 // not triggered when relocatable code is desired.
1394 && (shdr.get_sh_type() == elfcpp::SHT_REL
1395 || shdr.get_sh_type() == elfcpp::SHT_RELA))
1397 reloc_sections.push_back(i);
1401 if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
1404 // The .eh_frame section is special. It holds exception frame
1405 // information that we need to read in order to generate the
1406 // exception frame header. We process these after all the other
1407 // sections so that the exception frame reader can reliably
1408 // determine which sections are being discarded, and discard the
1409 // corresponding information.
1411 && strcmp(name, ".eh_frame") == 0
1412 && this->check_eh_frame_flags(&shdr))
1416 out_sections[i] = reinterpret_cast<Output_section*>(1);
1417 out_section_offsets[i] = invalid_address;
1419 else if (should_defer_layout)
1420 this->deferred_layout_.push_back(Deferred_layout(i, name,
1425 eh_frame_sections.push_back(i);
1429 if (is_gc_pass_two && parameters->options().gc_sections())
1431 // This is executed during the second pass of garbage
1432 // collection. do_layout has been called before and some
1433 // sections have been already discarded. Simply ignore
1434 // such sections this time around.
1435 if (out_sections[i] == NULL)
1437 gold_assert(out_section_offsets[i] == invalid_address);
1440 if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1441 && symtab->gc()->is_section_garbage(this, i))
1443 if (parameters->options().print_gc_sections())
1444 gold_info(_("%s: removing unused section from '%s'"
1446 program_name, this->section_name(i).c_str(),
1447 this->name().c_str());
1448 out_sections[i] = NULL;
1449 out_section_offsets[i] = invalid_address;
1454 if (is_gc_pass_two && parameters->options().icf_enabled())
1456 if (out_sections[i] == NULL)
1458 gold_assert(out_section_offsets[i] == invalid_address);
1461 if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1462 && symtab->icf()->is_section_folded(this, i))
1464 if (parameters->options().print_icf_sections())
1467 symtab->icf()->get_folded_section(this, i);
1468 Relobj* folded_obj =
1469 reinterpret_cast<Relobj*>(folded.first);
1470 gold_info(_("%s: ICF folding section '%s' in file '%s'"
1471 "into '%s' in file '%s'"),
1472 program_name, this->section_name(i).c_str(),
1473 this->name().c_str(),
1474 folded_obj->section_name(folded.second).c_str(),
1475 folded_obj->name().c_str());
1477 out_sections[i] = NULL;
1478 out_section_offsets[i] = invalid_address;
1483 // Defer layout here if input files are claimed by plugins. When gc
1484 // is turned on this function is called twice. For the second call
1485 // should_defer_layout should be false.
1486 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1488 gold_assert(!is_gc_pass_two);
1489 this->deferred_layout_.push_back(Deferred_layout(i, name,
1493 // Put dummy values here; real values will be supplied by
1494 // do_layout_deferred_sections.
1495 out_sections[i] = reinterpret_cast<Output_section*>(2);
1496 out_section_offsets[i] = invalid_address;
1500 // During gc_pass_two if a section that was previously deferred is
1501 // found, do not layout the section as layout_deferred_sections will
1502 // do it later from gold.cc.
1504 && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
1509 // This is during garbage collection. The out_sections are
1510 // assigned in the second call to this function.
1511 out_sections[i] = reinterpret_cast<Output_section*>(1);
1512 out_section_offsets[i] = invalid_address;
1516 // When garbage collection is switched on the actual layout
1517 // only happens in the second call.
1518 this->layout_section(layout, i, name, shdr, reloc_shndx[i],
1523 if (!is_gc_pass_two)
1524 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags, this);
1526 // When doing a relocatable link handle the reloc sections at the
1527 // end. Garbage collection and Identical Code Folding is not
1528 // turned on for relocatable code.
1530 this->size_relocatable_relocs();
1532 gold_assert(!(is_gc_or_icf) || reloc_sections.empty());
1534 for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
1535 p != reloc_sections.end();
1538 unsigned int i = *p;
1539 const unsigned char* pshdr;
1540 pshdr = section_headers_data + i * This::shdr_size;
1541 typename This::Shdr shdr(pshdr);
1543 unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1544 if (data_shndx >= shnum)
1546 // We already warned about this above.
1550 Output_section* data_section = out_sections[data_shndx];
1551 if (data_section == reinterpret_cast<Output_section*>(2))
1553 // The layout for the data section was deferred, so we need
1554 // to defer the relocation section, too.
1555 const char* name = pnames + shdr.get_sh_name();
1556 this->deferred_layout_relocs_.push_back(
1557 Deferred_layout(i, name, pshdr, 0, elfcpp::SHT_NULL));
1558 out_sections[i] = reinterpret_cast<Output_section*>(2);
1559 out_section_offsets[i] = invalid_address;
1562 if (data_section == NULL)
1564 out_sections[i] = NULL;
1565 out_section_offsets[i] = invalid_address;
1569 Relocatable_relocs* rr = new Relocatable_relocs();
1570 this->set_relocatable_relocs(i, rr);
1572 Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
1574 out_sections[i] = os;
1575 out_section_offsets[i] = invalid_address;
1578 // Handle the .eh_frame sections at the end.
1579 gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
1580 for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
1581 p != eh_frame_sections.end();
1584 gold_assert(external_symbols_offset != 0);
1586 unsigned int i = *p;
1587 const unsigned char* pshdr;
1588 pshdr = section_headers_data + i * This::shdr_size;
1589 typename This::Shdr shdr(pshdr);
1591 this->layout_eh_frame_section(layout,
1604 delete[] gc_sd->section_headers_data;
1605 delete[] gc_sd->section_names_data;
1606 delete[] gc_sd->symbols_data;
1607 delete[] gc_sd->symbol_names_data;
1608 this->set_symbols_data(NULL);
1612 delete sd->section_headers;
1613 sd->section_headers = NULL;
1614 delete sd->section_names;
1615 sd->section_names = NULL;
1619 // Layout sections whose layout was deferred while waiting for
1620 // input files from a plugin.
1622 template<int size, bool big_endian>
1624 Sized_relobj_file<size, big_endian>::do_layout_deferred_sections(Layout* layout)
1626 typename std::vector<Deferred_layout>::iterator deferred;
1628 for (deferred = this->deferred_layout_.begin();
1629 deferred != this->deferred_layout_.end();
1632 typename This::Shdr shdr(deferred->shdr_data_);
1633 // If the section is not included, it is because the garbage collector
1634 // decided it is not needed. Avoid reverting that decision.
1635 if (!this->is_section_included(deferred->shndx_))
1638 if (parameters->options().relocatable()
1639 || deferred->name_ != ".eh_frame"
1640 || !this->check_eh_frame_flags(&shdr))
1641 this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
1642 shdr, deferred->reloc_shndx_,
1643 deferred->reloc_type_);
1646 // Reading the symbols again here may be slow.
1647 Read_symbols_data sd;
1648 this->read_symbols(&sd);
1649 this->layout_eh_frame_section(layout,
1652 sd.symbol_names->data(),
1653 sd.symbol_names_size,
1656 deferred->reloc_shndx_,
1657 deferred->reloc_type_);
1661 this->deferred_layout_.clear();
1663 // Now handle the deferred relocation sections.
1665 Output_sections& out_sections(this->output_sections());
1666 std::vector<Address>& out_section_offsets(this->section_offsets());
1668 for (deferred = this->deferred_layout_relocs_.begin();
1669 deferred != this->deferred_layout_relocs_.end();
1672 unsigned int shndx = deferred->shndx_;
1673 typename This::Shdr shdr(deferred->shdr_data_);
1674 unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1676 Output_section* data_section = out_sections[data_shndx];
1677 if (data_section == NULL)
1679 out_sections[shndx] = NULL;
1680 out_section_offsets[shndx] = invalid_address;
1684 Relocatable_relocs* rr = new Relocatable_relocs();
1685 this->set_relocatable_relocs(shndx, rr);
1687 Output_section* os = layout->layout_reloc(this, shndx, shdr,
1689 out_sections[shndx] = os;
1690 out_section_offsets[shndx] = invalid_address;
1694 // Add the symbols to the symbol table.
1696 template<int size, bool big_endian>
1698 Sized_relobj_file<size, big_endian>::do_add_symbols(Symbol_table* symtab,
1699 Read_symbols_data* sd,
1702 if (sd->symbols == NULL)
1704 gold_assert(sd->symbol_names == NULL);
1708 const int sym_size = This::sym_size;
1709 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1711 if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
1713 this->error(_("size of symbols is not multiple of symbol size"));
1717 this->symbols_.resize(symcount);
1719 const char* sym_names =
1720 reinterpret_cast<const char*>(sd->symbol_names->data());
1721 symtab->add_from_relobj(this,
1722 sd->symbols->data() + sd->external_symbols_offset,
1723 symcount, this->local_symbol_count_,
1724 sym_names, sd->symbol_names_size,
1726 &this->defined_count_);
1730 delete sd->symbol_names;
1731 sd->symbol_names = NULL;
1734 // Find out if this object, that is a member of a lib group, should be included
1735 // in the link. We check every symbol defined by this object. If the symbol
1736 // table has a strong undefined reference to that symbol, we have to include
1739 template<int size, bool big_endian>
1740 Archive::Should_include
1741 Sized_relobj_file<size, big_endian>::do_should_include_member(
1742 Symbol_table* symtab,
1744 Read_symbols_data* sd,
1747 char* tmpbuf = NULL;
1748 size_t tmpbuflen = 0;
1749 const char* sym_names =
1750 reinterpret_cast<const char*>(sd->symbol_names->data());
1751 const unsigned char* syms =
1752 sd->symbols->data() + sd->external_symbols_offset;
1753 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1754 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1757 const unsigned char* p = syms;
1759 for (size_t i = 0; i < symcount; ++i, p += sym_size)
1761 elfcpp::Sym<size, big_endian> sym(p);
1762 unsigned int st_shndx = sym.get_st_shndx();
1763 if (st_shndx == elfcpp::SHN_UNDEF)
1766 unsigned int st_name = sym.get_st_name();
1767 const char* name = sym_names + st_name;
1769 Archive::Should_include t = Archive::should_include_member(symtab,
1775 if (t == Archive::SHOULD_INCLUDE_YES)
1784 return Archive::SHOULD_INCLUDE_UNKNOWN;
1787 // Iterate over global defined symbols, calling a visitor class V for each.
1789 template<int size, bool big_endian>
1791 Sized_relobj_file<size, big_endian>::do_for_all_global_symbols(
1792 Read_symbols_data* sd,
1793 Library_base::Symbol_visitor_base* v)
1795 const char* sym_names =
1796 reinterpret_cast<const char*>(sd->symbol_names->data());
1797 const unsigned char* syms =
1798 sd->symbols->data() + sd->external_symbols_offset;
1799 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1800 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1802 const unsigned char* p = syms;
1804 for (size_t i = 0; i < symcount; ++i, p += sym_size)
1806 elfcpp::Sym<size, big_endian> sym(p);
1807 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF)
1808 v->visit(sym_names + sym.get_st_name());
1812 // Return whether the local symbol SYMNDX has a PLT offset.
1814 template<int size, bool big_endian>
1816 Sized_relobj_file<size, big_endian>::local_has_plt_offset(
1817 unsigned int symndx) const
1819 typename Local_plt_offsets::const_iterator p =
1820 this->local_plt_offsets_.find(symndx);
1821 return p != this->local_plt_offsets_.end();
1824 // Get the PLT offset of a local symbol.
1826 template<int size, bool big_endian>
1828 Sized_relobj_file<size, big_endian>::local_plt_offset(unsigned int symndx) const
1830 typename Local_plt_offsets::const_iterator p =
1831 this->local_plt_offsets_.find(symndx);
1832 gold_assert(p != this->local_plt_offsets_.end());
1836 // Set the PLT offset of a local symbol.
1838 template<int size, bool big_endian>
1840 Sized_relobj_file<size, big_endian>::set_local_plt_offset(
1841 unsigned int symndx, unsigned int plt_offset)
1843 std::pair<typename Local_plt_offsets::iterator, bool> ins =
1844 this->local_plt_offsets_.insert(std::make_pair(symndx, plt_offset));
1845 gold_assert(ins.second);
1848 // First pass over the local symbols. Here we add their names to
1849 // *POOL and *DYNPOOL, and we store the symbol value in
1850 // THIS->LOCAL_VALUES_. This function is always called from a
1851 // singleton thread. This is followed by a call to
1852 // finalize_local_symbols.
1854 template<int size, bool big_endian>
1856 Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
1857 Stringpool* dynpool)
1859 gold_assert(this->symtab_shndx_ != -1U);
1860 if (this->symtab_shndx_ == 0)
1862 // This object has no symbols. Weird but legal.
1866 // Read the symbol table section header.
1867 const unsigned int symtab_shndx = this->symtab_shndx_;
1868 typename This::Shdr symtabshdr(this,
1869 this->elf_file_.section_header(symtab_shndx));
1870 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1872 // Read the local symbols.
1873 const int sym_size = This::sym_size;
1874 const unsigned int loccount = this->local_symbol_count_;
1875 gold_assert(loccount == symtabshdr.get_sh_info());
1876 off_t locsize = loccount * sym_size;
1877 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1878 locsize, true, true);
1880 // Read the symbol names.
1881 const unsigned int strtab_shndx =
1882 this->adjust_shndx(symtabshdr.get_sh_link());
1883 section_size_type strtab_size;
1884 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1887 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1889 // Loop over the local symbols.
1891 const Output_sections& out_sections(this->output_sections());
1892 unsigned int shnum = this->shnum();
1893 unsigned int count = 0;
1894 unsigned int dyncount = 0;
1895 // Skip the first, dummy, symbol.
1897 bool strip_all = parameters->options().strip_all();
1898 bool discard_all = parameters->options().discard_all();
1899 bool discard_locals = parameters->options().discard_locals();
1900 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1902 elfcpp::Sym<size, big_endian> sym(psyms);
1904 Symbol_value<size>& lv(this->local_values_[i]);
1907 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1909 lv.set_input_shndx(shndx, is_ordinary);
1911 if (sym.get_st_type() == elfcpp::STT_SECTION)
1912 lv.set_is_section_symbol();
1913 else if (sym.get_st_type() == elfcpp::STT_TLS)
1914 lv.set_is_tls_symbol();
1915 else if (sym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1916 lv.set_is_ifunc_symbol();
1918 // Save the input symbol value for use in do_finalize_local_symbols().
1919 lv.set_input_value(sym.get_st_value());
1921 // Decide whether this symbol should go into the output file.
1923 if ((shndx < shnum && out_sections[shndx] == NULL)
1924 || shndx == this->discarded_eh_frame_shndx_)
1926 lv.set_no_output_symtab_entry();
1927 gold_assert(!lv.needs_output_dynsym_entry());
1931 if (sym.get_st_type() == elfcpp::STT_SECTION)
1933 lv.set_no_output_symtab_entry();
1934 gold_assert(!lv.needs_output_dynsym_entry());
1938 if (sym.get_st_name() >= strtab_size)
1940 this->error(_("local symbol %u section name out of range: %u >= %u"),
1941 i, sym.get_st_name(),
1942 static_cast<unsigned int>(strtab_size));
1943 lv.set_no_output_symtab_entry();
1947 const char* name = pnames + sym.get_st_name();
1949 // If needed, add the symbol to the dynamic symbol table string pool.
1950 if (lv.needs_output_dynsym_entry())
1952 dynpool->add(name, true, NULL);
1957 || (discard_all && lv.may_be_discarded_from_output_symtab()))
1959 lv.set_no_output_symtab_entry();
1963 // If --discard-locals option is used, discard all temporary local
1964 // symbols. These symbols start with system-specific local label
1965 // prefixes, typically .L for ELF system. We want to be compatible
1966 // with GNU ld so here we essentially use the same check in
1967 // bfd_is_local_label(). The code is different because we already
1970 // - the symbol is local and thus cannot have global or weak binding.
1971 // - the symbol is not a section symbol.
1972 // - the symbol has a name.
1974 // We do not discard a symbol if it needs a dynamic symbol entry.
1976 && sym.get_st_type() != elfcpp::STT_FILE
1977 && !lv.needs_output_dynsym_entry()
1978 && lv.may_be_discarded_from_output_symtab()
1979 && parameters->target().is_local_label_name(name))
1981 lv.set_no_output_symtab_entry();
1985 // Discard the local symbol if -retain_symbols_file is specified
1986 // and the local symbol is not in that file.
1987 if (!parameters->options().should_retain_symbol(name))
1989 lv.set_no_output_symtab_entry();
1993 // Add the symbol to the symbol table string pool.
1994 pool->add(name, true, NULL);
1998 this->output_local_symbol_count_ = count;
1999 this->output_local_dynsym_count_ = dyncount;
2002 // Compute the final value of a local symbol.
2004 template<int size, bool big_endian>
2005 typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2006 Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
2008 const Symbol_value<size>* lv_in,
2009 Symbol_value<size>* lv_out,
2011 const Output_sections& out_sections,
2012 const std::vector<Address>& out_offsets,
2013 const Symbol_table* symtab)
2015 // We are going to overwrite *LV_OUT, if it has a merged symbol value,
2016 // we may have a memory leak.
2017 gold_assert(lv_out->has_output_value());
2020 unsigned int shndx = lv_in->input_shndx(&is_ordinary);
2022 // Set the output symbol value.
2026 if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
2027 lv_out->set_output_value(lv_in->input_value());
2030 this->error(_("unknown section index %u for local symbol %u"),
2032 lv_out->set_output_value(0);
2033 return This::CFLV_ERROR;
2038 if (shndx >= this->shnum())
2040 this->error(_("local symbol %u section index %u out of range"),
2042 lv_out->set_output_value(0);
2043 return This::CFLV_ERROR;
2046 Output_section* os = out_sections[shndx];
2047 Address secoffset = out_offsets[shndx];
2048 if (symtab->is_section_folded(this, shndx))
2050 gold_assert(os == NULL && secoffset == invalid_address);
2051 // Get the os of the section it is folded onto.
2052 Section_id folded = symtab->icf()->get_folded_section(this,
2054 gold_assert(folded.first != NULL);
2055 Sized_relobj_file<size, big_endian>* folded_obj = reinterpret_cast
2056 <Sized_relobj_file<size, big_endian>*>(folded.first);
2057 os = folded_obj->output_section(folded.second);
2058 gold_assert(os != NULL);
2059 secoffset = folded_obj->get_output_section_offset(folded.second);
2061 // This could be a relaxed input section.
2062 if (secoffset == invalid_address)
2064 const Output_relaxed_input_section* relaxed_section =
2065 os->find_relaxed_input_section(folded_obj, folded.second);
2066 gold_assert(relaxed_section != NULL);
2067 secoffset = relaxed_section->address() - os->address();
2073 // This local symbol belongs to a section we are discarding.
2074 // In some cases when applying relocations later, we will
2075 // attempt to match it to the corresponding kept section,
2076 // so we leave the input value unchanged here.
2077 return This::CFLV_DISCARDED;
2079 else if (secoffset == invalid_address)
2083 // This is a SHF_MERGE section or one which otherwise
2084 // requires special handling.
2085 if (shndx == this->discarded_eh_frame_shndx_)
2087 // This local symbol belongs to a discarded .eh_frame
2088 // section. Just treat it like the case in which
2089 // os == NULL above.
2090 gold_assert(this->has_eh_frame_);
2091 return This::CFLV_DISCARDED;
2093 else if (!lv_in->is_section_symbol())
2095 // This is not a section symbol. We can determine
2096 // the final value now.
2097 lv_out->set_output_value(
2098 os->output_address(this, shndx, lv_in->input_value()));
2100 else if (!os->find_starting_output_address(this, shndx, &start))
2102 // This is a section symbol, but apparently not one in a
2103 // merged section. First check to see if this is a relaxed
2104 // input section. If so, use its address. Otherwise just
2105 // use the start of the output section. This happens with
2106 // relocatable links when the input object has section
2107 // symbols for arbitrary non-merge sections.
2108 const Output_section_data* posd =
2109 os->find_relaxed_input_section(this, shndx);
2112 Address relocatable_link_adjustment =
2113 relocatable ? os->address() : 0;
2114 lv_out->set_output_value(posd->address()
2115 - relocatable_link_adjustment);
2118 lv_out->set_output_value(os->address());
2122 // We have to consider the addend to determine the
2123 // value to use in a relocation. START is the start
2124 // of this input section. If we are doing a relocatable
2125 // link, use offset from start output section instead of
2127 Address adjusted_start =
2128 relocatable ? start - os->address() : start;
2129 Merged_symbol_value<size>* msv =
2130 new Merged_symbol_value<size>(lv_in->input_value(),
2132 lv_out->set_merged_symbol_value(msv);
2135 else if (lv_in->is_tls_symbol())
2136 lv_out->set_output_value(os->tls_offset()
2138 + lv_in->input_value());
2140 lv_out->set_output_value((relocatable ? 0 : os->address())
2142 + lv_in->input_value());
2144 return This::CFLV_OK;
2147 // Compute final local symbol value. R_SYM is the index of a local
2148 // symbol in symbol table. LV points to a symbol value, which is
2149 // expected to hold the input value and to be over-written by the
2150 // final value. SYMTAB points to a symbol table. Some targets may want
2151 // to know would-be-finalized local symbol values in relaxation.
2152 // Hence we provide this method. Since this method updates *LV, a
2153 // callee should make a copy of the original local symbol value and
2154 // use the copy instead of modifying an object's local symbols before
2155 // everything is finalized. The caller should also free up any allocated
2156 // memory in the return value in *LV.
2157 template<int size, bool big_endian>
2158 typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2159 Sized_relobj_file<size, big_endian>::compute_final_local_value(
2161 const Symbol_value<size>* lv_in,
2162 Symbol_value<size>* lv_out,
2163 const Symbol_table* symtab)
2165 // This is just a wrapper of compute_final_local_value_internal.
2166 const bool relocatable = parameters->options().relocatable();
2167 const Output_sections& out_sections(this->output_sections());
2168 const std::vector<Address>& out_offsets(this->section_offsets());
2169 return this->compute_final_local_value_internal(r_sym, lv_in, lv_out,
2170 relocatable, out_sections,
2171 out_offsets, symtab);
2174 // Finalize the local symbols. Here we set the final value in
2175 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
2176 // This function is always called from a singleton thread. The actual
2177 // output of the local symbols will occur in a separate task.
2179 template<int size, bool big_endian>
2181 Sized_relobj_file<size, big_endian>::do_finalize_local_symbols(
2184 Symbol_table* symtab)
2186 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2188 const unsigned int loccount = this->local_symbol_count_;
2189 this->local_symbol_offset_ = off;
2191 const bool relocatable = parameters->options().relocatable();
2192 const Output_sections& out_sections(this->output_sections());
2193 const std::vector<Address>& out_offsets(this->section_offsets());
2195 for (unsigned int i = 1; i < loccount; ++i)
2197 Symbol_value<size>* lv = &this->local_values_[i];
2199 Compute_final_local_value_status cflv_status =
2200 this->compute_final_local_value_internal(i, lv, lv, relocatable,
2201 out_sections, out_offsets,
2203 switch (cflv_status)
2206 if (!lv->is_output_symtab_index_set())
2208 lv->set_output_symtab_index(index);
2212 case CFLV_DISCARDED:
2223 // Set the output dynamic symbol table indexes for the local variables.
2225 template<int size, bool big_endian>
2227 Sized_relobj_file<size, big_endian>::do_set_local_dynsym_indexes(
2230 const unsigned int loccount = this->local_symbol_count_;
2231 for (unsigned int i = 1; i < loccount; ++i)
2233 Symbol_value<size>& lv(this->local_values_[i]);
2234 if (lv.needs_output_dynsym_entry())
2236 lv.set_output_dynsym_index(index);
2243 // Set the offset where local dynamic symbol information will be stored.
2244 // Returns the count of local symbols contributed to the symbol table by
2247 template<int size, bool big_endian>
2249 Sized_relobj_file<size, big_endian>::do_set_local_dynsym_offset(off_t off)
2251 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2252 this->local_dynsym_offset_ = off;
2253 return this->output_local_dynsym_count_;
2256 // If Symbols_data is not NULL get the section flags from here otherwise
2257 // get it from the file.
2259 template<int size, bool big_endian>
2261 Sized_relobj_file<size, big_endian>::do_section_flags(unsigned int shndx)
2263 Symbols_data* sd = this->get_symbols_data();
2266 const unsigned char* pshdrs = sd->section_headers_data
2267 + This::shdr_size * shndx;
2268 typename This::Shdr shdr(pshdrs);
2269 return shdr.get_sh_flags();
2271 // If sd is NULL, read the section header from the file.
2272 return this->elf_file_.section_flags(shndx);
2275 // Get the section's ent size from Symbols_data. Called by get_section_contents
2278 template<int size, bool big_endian>
2280 Sized_relobj_file<size, big_endian>::do_section_entsize(unsigned int shndx)
2282 Symbols_data* sd = this->get_symbols_data();
2283 gold_assert(sd != NULL);
2285 const unsigned char* pshdrs = sd->section_headers_data
2286 + This::shdr_size * shndx;
2287 typename This::Shdr shdr(pshdrs);
2288 return shdr.get_sh_entsize();
2291 // Write out the local symbols.
2293 template<int size, bool big_endian>
2295 Sized_relobj_file<size, big_endian>::write_local_symbols(
2297 const Stringpool* sympool,
2298 const Stringpool* dynpool,
2299 Output_symtab_xindex* symtab_xindex,
2300 Output_symtab_xindex* dynsym_xindex,
2303 const bool strip_all = parameters->options().strip_all();
2306 if (this->output_local_dynsym_count_ == 0)
2308 this->output_local_symbol_count_ = 0;
2311 gold_assert(this->symtab_shndx_ != -1U);
2312 if (this->symtab_shndx_ == 0)
2314 // This object has no symbols. Weird but legal.
2318 // Read the symbol table section header.
2319 const unsigned int symtab_shndx = this->symtab_shndx_;
2320 typename This::Shdr symtabshdr(this,
2321 this->elf_file_.section_header(symtab_shndx));
2322 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
2323 const unsigned int loccount = this->local_symbol_count_;
2324 gold_assert(loccount == symtabshdr.get_sh_info());
2326 // Read the local symbols.
2327 const int sym_size = This::sym_size;
2328 off_t locsize = loccount * sym_size;
2329 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
2330 locsize, true, false);
2332 // Read the symbol names.
2333 const unsigned int strtab_shndx =
2334 this->adjust_shndx(symtabshdr.get_sh_link());
2335 section_size_type strtab_size;
2336 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
2339 const char* pnames = reinterpret_cast<const char*>(pnamesu);
2341 // Get views into the output file for the portions of the symbol table
2342 // and the dynamic symbol table that we will be writing.
2343 off_t output_size = this->output_local_symbol_count_ * sym_size;
2344 unsigned char* oview = NULL;
2345 if (output_size > 0)
2346 oview = of->get_output_view(symtab_off + this->local_symbol_offset_,
2349 off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
2350 unsigned char* dyn_oview = NULL;
2351 if (dyn_output_size > 0)
2352 dyn_oview = of->get_output_view(this->local_dynsym_offset_,
2355 const Output_sections out_sections(this->output_sections());
2357 gold_assert(this->local_values_.size() == loccount);
2359 unsigned char* ov = oview;
2360 unsigned char* dyn_ov = dyn_oview;
2362 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
2364 elfcpp::Sym<size, big_endian> isym(psyms);
2366 Symbol_value<size>& lv(this->local_values_[i]);
2369 unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
2373 gold_assert(st_shndx < out_sections.size());
2374 if (out_sections[st_shndx] == NULL)
2376 st_shndx = out_sections[st_shndx]->out_shndx();
2377 if (st_shndx >= elfcpp::SHN_LORESERVE)
2379 if (lv.has_output_symtab_entry())
2380 symtab_xindex->add(lv.output_symtab_index(), st_shndx);
2381 if (lv.has_output_dynsym_entry())
2382 dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
2383 st_shndx = elfcpp::SHN_XINDEX;
2387 // Write the symbol to the output symbol table.
2388 if (lv.has_output_symtab_entry())
2390 elfcpp::Sym_write<size, big_endian> osym(ov);
2392 gold_assert(isym.get_st_name() < strtab_size);
2393 const char* name = pnames + isym.get_st_name();
2394 osym.put_st_name(sympool->get_offset(name));
2395 osym.put_st_value(this->local_values_[i].value(this, 0));
2396 osym.put_st_size(isym.get_st_size());
2397 osym.put_st_info(isym.get_st_info());
2398 osym.put_st_other(isym.get_st_other());
2399 osym.put_st_shndx(st_shndx);
2404 // Write the symbol to the output dynamic symbol table.
2405 if (lv.has_output_dynsym_entry())
2407 gold_assert(dyn_ov < dyn_oview + dyn_output_size);
2408 elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
2410 gold_assert(isym.get_st_name() < strtab_size);
2411 const char* name = pnames + isym.get_st_name();
2412 osym.put_st_name(dynpool->get_offset(name));
2413 osym.put_st_value(this->local_values_[i].value(this, 0));
2414 osym.put_st_size(isym.get_st_size());
2415 osym.put_st_info(isym.get_st_info());
2416 osym.put_st_other(isym.get_st_other());
2417 osym.put_st_shndx(st_shndx);
2424 if (output_size > 0)
2426 gold_assert(ov - oview == output_size);
2427 of->write_output_view(symtab_off + this->local_symbol_offset_,
2428 output_size, oview);
2431 if (dyn_output_size > 0)
2433 gold_assert(dyn_ov - dyn_oview == dyn_output_size);
2434 of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
2439 // Set *INFO to symbolic information about the offset OFFSET in the
2440 // section SHNDX. Return true if we found something, false if we
2443 template<int size, bool big_endian>
2445 Sized_relobj_file<size, big_endian>::get_symbol_location_info(
2448 Symbol_location_info* info)
2450 if (this->symtab_shndx_ == 0)
2453 section_size_type symbols_size;
2454 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
2458 unsigned int symbol_names_shndx =
2459 this->adjust_shndx(this->section_link(this->symtab_shndx_));
2460 section_size_type names_size;
2461 const unsigned char* symbol_names_u =
2462 this->section_contents(symbol_names_shndx, &names_size, false);
2463 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
2465 const int sym_size = This::sym_size;
2466 const size_t count = symbols_size / sym_size;
2468 const unsigned char* p = symbols;
2469 for (size_t i = 0; i < count; ++i, p += sym_size)
2471 elfcpp::Sym<size, big_endian> sym(p);
2473 if (sym.get_st_type() == elfcpp::STT_FILE)
2475 if (sym.get_st_name() >= names_size)
2476 info->source_file = "(invalid)";
2478 info->source_file = symbol_names + sym.get_st_name();
2483 unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
2486 && st_shndx == shndx
2487 && static_cast<off_t>(sym.get_st_value()) <= offset
2488 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
2491 if (sym.get_st_name() > names_size)
2492 info->enclosing_symbol_name = "(invalid)";
2495 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
2496 if (parameters->options().do_demangle())
2498 char* demangled_name = cplus_demangle(
2499 info->enclosing_symbol_name.c_str(),
2500 DMGL_ANSI | DMGL_PARAMS);
2501 if (demangled_name != NULL)
2503 info->enclosing_symbol_name.assign(demangled_name);
2504 free(demangled_name);
2515 // Look for a kept section corresponding to the given discarded section,
2516 // and return its output address. This is used only for relocations in
2517 // debugging sections. If we can't find the kept section, return 0.
2519 template<int size, bool big_endian>
2520 typename Sized_relobj_file<size, big_endian>::Address
2521 Sized_relobj_file<size, big_endian>::map_to_kept_section(
2525 Relobj* kept_object;
2526 unsigned int kept_shndx;
2527 if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
2529 Sized_relobj_file<size, big_endian>* kept_relobj =
2530 static_cast<Sized_relobj_file<size, big_endian>*>(kept_object);
2531 Output_section* os = kept_relobj->output_section(kept_shndx);
2532 Address offset = kept_relobj->get_output_section_offset(kept_shndx);
2533 if (os != NULL && offset != invalid_address)
2536 return os->address() + offset;
2543 // Get symbol counts.
2545 template<int size, bool big_endian>
2547 Sized_relobj_file<size, big_endian>::do_get_global_symbol_counts(
2548 const Symbol_table*,
2552 *defined = this->defined_count_;
2554 for (typename Symbols::const_iterator p = this->symbols_.begin();
2555 p != this->symbols_.end();
2558 && (*p)->source() == Symbol::FROM_OBJECT
2559 && (*p)->object() == this
2560 && (*p)->is_defined())
2565 // Input_objects methods.
2567 // Add a regular relocatable object to the list. Return false if this
2568 // object should be ignored.
2571 Input_objects::add_object(Object* obj)
2573 // Print the filename if the -t/--trace option is selected.
2574 if (parameters->options().trace())
2575 gold_info("%s", obj->name().c_str());
2577 if (!obj->is_dynamic())
2578 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
2581 // See if this is a duplicate SONAME.
2582 Dynobj* dynobj = static_cast<Dynobj*>(obj);
2583 const char* soname = dynobj->soname();
2585 std::pair<Unordered_set<std::string>::iterator, bool> ins =
2586 this->sonames_.insert(soname);
2589 // We have already seen a dynamic object with this soname.
2593 this->dynobj_list_.push_back(dynobj);
2596 // Add this object to the cross-referencer if requested.
2597 if (parameters->options().user_set_print_symbol_counts()
2598 || parameters->options().cref())
2600 if (this->cref_ == NULL)
2601 this->cref_ = new Cref();
2602 this->cref_->add_object(obj);
2608 // For each dynamic object, record whether we've seen all of its
2609 // explicit dependencies.
2612 Input_objects::check_dynamic_dependencies() const
2614 bool issued_copy_dt_needed_error = false;
2615 for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
2616 p != this->dynobj_list_.end();
2619 const Dynobj::Needed& needed((*p)->needed());
2620 bool found_all = true;
2621 Dynobj::Needed::const_iterator pneeded;
2622 for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
2624 if (this->sonames_.find(*pneeded) == this->sonames_.end())
2630 (*p)->set_has_unknown_needed_entries(!found_all);
2632 // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2633 // that gold does not support. However, they cause no trouble
2634 // unless there is a DT_NEEDED entry that we don't know about;
2635 // warn only in that case.
2637 && !issued_copy_dt_needed_error
2638 && (parameters->options().copy_dt_needed_entries()
2639 || parameters->options().add_needed()))
2641 const char* optname;
2642 if (parameters->options().copy_dt_needed_entries())
2643 optname = "--copy-dt-needed-entries";
2645 optname = "--add-needed";
2646 gold_error(_("%s is not supported but is required for %s in %s"),
2647 optname, (*pneeded).c_str(), (*p)->name().c_str());
2648 issued_copy_dt_needed_error = true;
2653 // Start processing an archive.
2656 Input_objects::archive_start(Archive* archive)
2658 if (parameters->options().user_set_print_symbol_counts()
2659 || parameters->options().cref())
2661 if (this->cref_ == NULL)
2662 this->cref_ = new Cref();
2663 this->cref_->add_archive_start(archive);
2667 // Stop processing an archive.
2670 Input_objects::archive_stop(Archive* archive)
2672 if (parameters->options().user_set_print_symbol_counts()
2673 || parameters->options().cref())
2674 this->cref_->add_archive_stop(archive);
2677 // Print symbol counts
2680 Input_objects::print_symbol_counts(const Symbol_table* symtab) const
2682 if (parameters->options().user_set_print_symbol_counts()
2683 && this->cref_ != NULL)
2684 this->cref_->print_symbol_counts(symtab);
2687 // Print a cross reference table.
2690 Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const
2692 if (parameters->options().cref() && this->cref_ != NULL)
2693 this->cref_->print_cref(symtab, f);
2696 // Relocate_info methods.
2698 // Return a string describing the location of a relocation when file
2699 // and lineno information is not available. This is only used in
2702 template<int size, bool big_endian>
2704 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
2706 Sized_dwarf_line_info<size, big_endian> line_info(this->object);
2707 std::string ret = line_info.addr2line(this->data_shndx, offset, NULL);
2711 ret = this->object->name();
2713 Symbol_location_info info;
2714 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
2716 if (!info.source_file.empty())
2719 ret += info.source_file;
2721 size_t len = info.enclosing_symbol_name.length() + 100;
2722 char* buf = new char[len];
2723 snprintf(buf, len, _(":function %s"),
2724 info.enclosing_symbol_name.c_str());
2731 ret += this->object->section_name(this->data_shndx);
2733 snprintf(buf, sizeof buf, "+0x%lx)", static_cast<long>(offset));
2738 } // End namespace gold.
2743 using namespace gold;
2745 // Read an ELF file with the header and return the appropriate
2746 // instance of Object.
2748 template<int size, bool big_endian>
2750 make_elf_sized_object(const std::string& name, Input_file* input_file,
2751 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
2752 bool* punconfigured)
2754 Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
2755 ehdr.get_e_ident()[elfcpp::EI_OSABI],
2756 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
2758 gold_fatal(_("%s: unsupported ELF machine number %d"),
2759 name.c_str(), ehdr.get_e_machine());
2761 if (!parameters->target_valid())
2762 set_parameters_target(target);
2763 else if (target != ¶meters->target())
2765 if (punconfigured != NULL)
2766 *punconfigured = true;
2768 gold_error(_("%s: incompatible target"), name.c_str());
2772 return target->make_elf_object<size, big_endian>(name, input_file, offset,
2776 } // End anonymous namespace.
2781 // Return whether INPUT_FILE is an ELF object.
2784 is_elf_object(Input_file* input_file, off_t offset,
2785 const unsigned char** start, int* read_size)
2787 off_t filesize = input_file->file().filesize();
2788 int want = elfcpp::Elf_recognizer::max_header_size;
2789 if (filesize - offset < want)
2790 want = filesize - offset;
2792 const unsigned char* p = input_file->file().get_view(offset, 0, want,
2797 return elfcpp::Elf_recognizer::is_elf_file(p, want);
2800 // Read an ELF file and return the appropriate instance of Object.
2803 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
2804 const unsigned char* p, section_offset_type bytes,
2805 bool* punconfigured)
2807 if (punconfigured != NULL)
2808 *punconfigured = false;
2811 bool big_endian = false;
2813 if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
2814 &big_endian, &error))
2816 gold_error(_("%s: %s"), name.c_str(), error.c_str());
2824 #ifdef HAVE_TARGET_32_BIG
2825 elfcpp::Ehdr<32, true> ehdr(p);
2826 return make_elf_sized_object<32, true>(name, input_file,
2827 offset, ehdr, punconfigured);
2829 if (punconfigured != NULL)
2830 *punconfigured = true;
2832 gold_error(_("%s: not configured to support "
2833 "32-bit big-endian object"),
2840 #ifdef HAVE_TARGET_32_LITTLE
2841 elfcpp::Ehdr<32, false> ehdr(p);
2842 return make_elf_sized_object<32, false>(name, input_file,
2843 offset, ehdr, punconfigured);
2845 if (punconfigured != NULL)
2846 *punconfigured = true;
2848 gold_error(_("%s: not configured to support "
2849 "32-bit little-endian object"),
2855 else if (size == 64)
2859 #ifdef HAVE_TARGET_64_BIG
2860 elfcpp::Ehdr<64, true> ehdr(p);
2861 return make_elf_sized_object<64, true>(name, input_file,
2862 offset, ehdr, punconfigured);
2864 if (punconfigured != NULL)
2865 *punconfigured = true;
2867 gold_error(_("%s: not configured to support "
2868 "64-bit big-endian object"),
2875 #ifdef HAVE_TARGET_64_LITTLE
2876 elfcpp::Ehdr<64, false> ehdr(p);
2877 return make_elf_sized_object<64, false>(name, input_file,
2878 offset, ehdr, punconfigured);
2880 if (punconfigured != NULL)
2881 *punconfigured = true;
2883 gold_error(_("%s: not configured to support "
2884 "64-bit little-endian object"),
2894 // Instantiate the templates we need.
2896 #ifdef HAVE_TARGET_32_LITTLE
2899 Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
2900 Read_symbols_data*);
2903 #ifdef HAVE_TARGET_32_BIG
2906 Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
2907 Read_symbols_data*);
2910 #ifdef HAVE_TARGET_64_LITTLE
2913 Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
2914 Read_symbols_data*);
2917 #ifdef HAVE_TARGET_64_BIG
2920 Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
2921 Read_symbols_data*);
2924 #ifdef HAVE_TARGET_32_LITTLE
2926 class Sized_relobj_file<32, false>;
2929 #ifdef HAVE_TARGET_32_BIG
2931 class Sized_relobj_file<32, true>;
2934 #ifdef HAVE_TARGET_64_LITTLE
2936 class Sized_relobj_file<64, false>;
2939 #ifdef HAVE_TARGET_64_BIG
2941 class Sized_relobj_file<64, true>;
2944 #ifdef HAVE_TARGET_32_LITTLE
2946 struct Relocate_info<32, false>;
2949 #ifdef HAVE_TARGET_32_BIG
2951 struct Relocate_info<32, true>;
2954 #ifdef HAVE_TARGET_64_LITTLE
2956 struct Relocate_info<64, false>;
2959 #ifdef HAVE_TARGET_64_BIG
2961 struct Relocate_info<64, true>;
2964 #ifdef HAVE_TARGET_32_LITTLE
2967 Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int);
2971 Xindex::read_symtab_xindex<32, false>(Object*, unsigned int,
2972 const unsigned char*);
2975 #ifdef HAVE_TARGET_32_BIG
2978 Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int);
2982 Xindex::read_symtab_xindex<32, true>(Object*, unsigned int,
2983 const unsigned char*);
2986 #ifdef HAVE_TARGET_64_LITTLE
2989 Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int);
2993 Xindex::read_symtab_xindex<64, false>(Object*, unsigned int,
2994 const unsigned char*);
2997 #ifdef HAVE_TARGET_64_BIG
3000 Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int);
3004 Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
3005 const unsigned char*);
3008 } // End namespace gold.