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. This
752 // is a lot of effort to go to to read a string. Why didn't they
753 // just have the group signature point into the string table, rather
754 // than indirect through a symbol?
756 // Get the appropriate symbol table header (this will normally be
757 // the single SHT_SYMTAB section, but in principle it need not be).
758 const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
759 typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
761 // Read the symbol table entry.
762 unsigned int symndx = shdr.get_sh_info();
763 if (symndx >= symshdr.get_sh_size() / This::sym_size)
765 this->error(_("section group %u info %u out of range"),
769 off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
770 const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
772 elfcpp::Sym<size, big_endian> sym(psym);
774 // Read the symbol table names.
775 section_size_type symnamelen;
776 const unsigned char* psymnamesu;
777 psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
779 const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
781 // Get the section group signature.
782 if (sym.get_st_name() >= symnamelen)
784 this->error(_("symbol %u name offset %u out of range"),
785 symndx, sym.get_st_name());
789 std::string signature(psymnames + sym.get_st_name());
791 // It seems that some versions of gas will create a section group
792 // associated with a section symbol, and then fail to give a name to
793 // the section symbol. In such a case, use the name of the section.
794 if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
797 unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
800 if (!is_ordinary || sym_shndx >= this->shnum())
802 this->error(_("symbol %u invalid section index %u"),
806 typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
807 if (member_shdr.get_sh_name() < section_names_size)
808 signature = section_names + member_shdr.get_sh_name();
811 // Record this section group in the layout, and see whether we've already
812 // seen one with the same signature.
815 Kept_section* kept_section = NULL;
817 if ((flags & elfcpp::GRP_COMDAT) == 0)
819 include_group = true;
824 include_group = layout->find_or_add_kept_section(signature,
826 true, &kept_section);
830 if (is_comdat && include_group)
832 Incremental_inputs* incremental_inputs = layout->incremental_inputs();
833 if (incremental_inputs != NULL)
834 incremental_inputs->report_comdat_group(this, signature.c_str());
837 size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
839 std::vector<unsigned int> shndxes;
840 bool relocate_group = include_group && parameters->options().relocatable();
842 shndxes.reserve(count - 1);
844 for (size_t i = 1; i < count; ++i)
846 elfcpp::Elf_Word shndx =
847 this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
850 shndxes.push_back(shndx);
852 if (shndx >= this->shnum())
854 this->error(_("section %u in section group %u out of range"),
859 // Check for an earlier section number, since we're going to get
860 // it wrong--we may have already decided to include the section.
862 this->error(_("invalid section group %u refers to earlier section %u"),
865 // Get the name of the member section.
866 typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size);
867 if (member_shdr.get_sh_name() >= section_names_size)
869 // This is an error, but it will be diagnosed eventually
870 // in do_layout, so we don't need to do anything here but
874 std::string mname(section_names + member_shdr.get_sh_name());
879 kept_section->add_comdat_section(mname, shndx,
880 member_shdr.get_sh_size());
884 (*omit)[shndx] = true;
888 Relobj* kept_object = kept_section->object();
889 if (kept_section->is_comdat())
891 // Find the corresponding kept section, and store
892 // that info in the discarded section table.
893 unsigned int kept_shndx;
895 if (kept_section->find_comdat_section(mname, &kept_shndx,
898 // We don't keep a mapping for this section if
899 // it has a different size. The mapping is only
900 // used for relocation processing, and we don't
901 // want to treat the sections as similar if the
902 // sizes are different. Checking the section
903 // size is the approach used by the GNU linker.
904 if (kept_size == member_shdr.get_sh_size())
905 this->set_kept_comdat_section(shndx, kept_object,
911 // The existing section is a linkonce section. Add
912 // a mapping if there is exactly one section in the
913 // group (which is true when COUNT == 2) and if it
916 && (kept_section->linkonce_size()
917 == member_shdr.get_sh_size()))
918 this->set_kept_comdat_section(shndx, kept_object,
919 kept_section->shndx());
926 layout->layout_group(symtab, this, index, name, signature.c_str(),
927 shdr, flags, &shndxes);
929 return include_group;
932 // Whether to include a linkonce section in the link. NAME is the
933 // name of the section and SHDR is the section header.
935 // Linkonce sections are a GNU extension implemented in the original
936 // GNU linker before section groups were defined. The semantics are
937 // that we only include one linkonce section with a given name. The
938 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
939 // where T is the type of section and SYMNAME is the name of a symbol.
940 // In an attempt to make linkonce sections interact well with section
941 // groups, we try to identify SYMNAME and use it like a section group
942 // signature. We want to block section groups with that signature,
943 // but not other linkonce sections with that signature. We also use
944 // the full name of the linkonce section as a normal section group
947 template<int size, bool big_endian>
949 Sized_relobj_file<size, big_endian>::include_linkonce_section(
953 const elfcpp::Shdr<size, big_endian>& shdr)
955 typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
956 // In general the symbol name we want will be the string following
957 // the last '.'. However, we have to handle the case of
958 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
959 // some versions of gcc. So we use a heuristic: if the name starts
960 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
961 // we look for the last '.'. We can't always simply skip
962 // ".gnu.linkonce.X", because we have to deal with cases like
963 // ".gnu.linkonce.d.rel.ro.local".
964 const char* const linkonce_t = ".gnu.linkonce.t.";
966 if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
967 symname = name + strlen(linkonce_t);
969 symname = strrchr(name, '.') + 1;
970 std::string sig1(symname);
971 std::string sig2(name);
974 bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
976 bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
981 // We are not including this section because we already saw the
982 // name of the section as a signature. This normally implies
983 // that the kept section is another linkonce section. If it is
984 // the same size, record it as the section which corresponds to
986 if (kept2->object() != NULL
987 && !kept2->is_comdat()
988 && kept2->linkonce_size() == sh_size)
989 this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
993 // The section is being discarded on the basis of its symbol
994 // name. This means that the corresponding kept section was
995 // part of a comdat group, and it will be difficult to identify
996 // the specific section within that group that corresponds to
997 // this linkonce section. We'll handle the simple case where
998 // the group has only one member section. Otherwise, it's not
1000 unsigned int kept_shndx;
1002 if (kept1->object() != NULL
1003 && kept1->is_comdat()
1004 && kept1->find_single_comdat_section(&kept_shndx, &kept_size)
1005 && kept_size == sh_size)
1006 this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
1010 kept1->set_linkonce_size(sh_size);
1011 kept2->set_linkonce_size(sh_size);
1014 return include1 && include2;
1017 // Layout an input section.
1019 template<int size, bool big_endian>
1021 Sized_relobj_file<size, big_endian>::layout_section(
1025 const typename This::Shdr& shdr,
1026 unsigned int reloc_shndx,
1027 unsigned int reloc_type)
1030 Output_section* os = layout->layout(this, shndx, name, shdr,
1031 reloc_shndx, reloc_type, &offset);
1033 this->output_sections()[shndx] = os;
1035 this->section_offsets()[shndx] = invalid_address;
1037 this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1039 // If this section requires special handling, and if there are
1040 // relocs that apply to it, then we must do the special handling
1041 // before we apply the relocs.
1042 if (offset == -1 && reloc_shndx != 0)
1043 this->set_relocs_must_follow_section_writes();
1046 // Layout an input .eh_frame section.
1048 template<int size, bool big_endian>
1050 Sized_relobj_file<size, big_endian>::layout_eh_frame_section(
1052 const unsigned char* symbols_data,
1053 section_size_type symbols_size,
1054 const unsigned char* symbol_names_data,
1055 section_size_type symbol_names_size,
1057 const typename This::Shdr& shdr,
1058 unsigned int reloc_shndx,
1059 unsigned int reloc_type)
1061 gold_assert(this->has_eh_frame_);
1064 Output_section* os = layout->layout_eh_frame(this,
1074 this->output_sections()[shndx] = os;
1075 if (os == NULL || offset == -1)
1077 // An object can contain at most one section holding exception
1078 // frame information.
1079 gold_assert(this->discarded_eh_frame_shndx_ == -1U);
1080 this->discarded_eh_frame_shndx_ = shndx;
1081 this->section_offsets()[shndx] = invalid_address;
1084 this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
1086 // If this section requires special handling, and if there are
1087 // relocs that aply to it, then we must do the special handling
1088 // before we apply the relocs.
1089 if (os != NULL && offset == -1 && reloc_shndx != 0)
1090 this->set_relocs_must_follow_section_writes();
1093 // Lay out the input sections. We walk through the sections and check
1094 // whether they should be included in the link. If they should, we
1095 // pass them to the Layout object, which will return an output section
1097 // During garbage collection (--gc-sections) and identical code folding
1098 // (--icf), this function is called twice. When it is called the first
1099 // time, it is for setting up some sections as roots to a work-list for
1100 // --gc-sections and to do comdat processing. Actual layout happens the
1101 // second time around after all the relevant sections have been determined.
1102 // The first time, is_worklist_ready or is_icf_ready is false. It is then
1103 // set to true after the garbage collection worklist or identical code
1104 // folding is processed and the relevant sections to be kept are
1105 // determined. Then, this function is called again to layout the sections.
1107 template<int size, bool big_endian>
1109 Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
1111 Read_symbols_data* sd)
1113 const unsigned int shnum = this->shnum();
1114 bool is_gc_pass_one = ((parameters->options().gc_sections()
1115 && !symtab->gc()->is_worklist_ready())
1116 || (parameters->options().icf_enabled()
1117 && !symtab->icf()->is_icf_ready()));
1119 bool is_gc_pass_two = ((parameters->options().gc_sections()
1120 && symtab->gc()->is_worklist_ready())
1121 || (parameters->options().icf_enabled()
1122 && symtab->icf()->is_icf_ready()));
1124 bool is_gc_or_icf = (parameters->options().gc_sections()
1125 || parameters->options().icf_enabled());
1127 // Both is_gc_pass_one and is_gc_pass_two should not be true.
1128 gold_assert(!(is_gc_pass_one && is_gc_pass_two));
1132 Symbols_data* gc_sd = NULL;
1135 // During garbage collection save the symbols data to use it when
1136 // re-entering this function.
1137 gc_sd = new Symbols_data;
1138 this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
1139 this->set_symbols_data(gc_sd);
1141 else if (is_gc_pass_two)
1143 gc_sd = this->get_symbols_data();
1146 const unsigned char* section_headers_data = NULL;
1147 section_size_type section_names_size;
1148 const unsigned char* symbols_data = NULL;
1149 section_size_type symbols_size;
1150 section_offset_type external_symbols_offset;
1151 const unsigned char* symbol_names_data = NULL;
1152 section_size_type symbol_names_size;
1156 section_headers_data = gc_sd->section_headers_data;
1157 section_names_size = gc_sd->section_names_size;
1158 symbols_data = gc_sd->symbols_data;
1159 symbols_size = gc_sd->symbols_size;
1160 external_symbols_offset = gc_sd->external_symbols_offset;
1161 symbol_names_data = gc_sd->symbol_names_data;
1162 symbol_names_size = gc_sd->symbol_names_size;
1166 section_headers_data = sd->section_headers->data();
1167 section_names_size = sd->section_names_size;
1168 if (sd->symbols != NULL)
1169 symbols_data = sd->symbols->data();
1170 symbols_size = sd->symbols_size;
1171 external_symbols_offset = sd->external_symbols_offset;
1172 if (sd->symbol_names != NULL)
1173 symbol_names_data = sd->symbol_names->data();
1174 symbol_names_size = sd->symbol_names_size;
1177 // Get the section headers.
1178 const unsigned char* shdrs = section_headers_data;
1179 const unsigned char* pshdrs;
1181 // Get the section names.
1182 const unsigned char* pnamesu = (is_gc_or_icf)
1183 ? gc_sd->section_names_data
1184 : sd->section_names->data();
1186 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1188 // If any input files have been claimed by plugins, we need to defer
1189 // actual layout until the replacement files have arrived.
1190 const bool should_defer_layout =
1191 (parameters->options().has_plugins()
1192 && parameters->options().plugins()->should_defer_layout());
1193 unsigned int num_sections_to_defer = 0;
1195 // For each section, record the index of the reloc section if any.
1196 // Use 0 to mean that there is no reloc section, -1U to mean that
1197 // there is more than one.
1198 std::vector<unsigned int> reloc_shndx(shnum, 0);
1199 std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
1200 // Skip the first, dummy, section.
1201 pshdrs = shdrs + This::shdr_size;
1202 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1204 typename This::Shdr shdr(pshdrs);
1206 // Count the number of sections whose layout will be deferred.
1207 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1208 ++num_sections_to_defer;
1210 unsigned int sh_type = shdr.get_sh_type();
1211 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
1213 unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
1214 if (target_shndx == 0 || target_shndx >= shnum)
1216 this->error(_("relocation section %u has bad info %u"),
1221 if (reloc_shndx[target_shndx] != 0)
1222 reloc_shndx[target_shndx] = -1U;
1225 reloc_shndx[target_shndx] = i;
1226 reloc_type[target_shndx] = sh_type;
1231 Output_sections& out_sections(this->output_sections());
1232 std::vector<Address>& out_section_offsets(this->section_offsets());
1234 if (!is_gc_pass_two)
1236 out_sections.resize(shnum);
1237 out_section_offsets.resize(shnum);
1240 // If we are only linking for symbols, then there is nothing else to
1242 if (this->input_file()->just_symbols())
1244 if (!is_gc_pass_two)
1246 delete sd->section_headers;
1247 sd->section_headers = NULL;
1248 delete sd->section_names;
1249 sd->section_names = NULL;
1254 if (num_sections_to_defer > 0)
1256 parameters->options().plugins()->add_deferred_layout_object(this);
1257 this->deferred_layout_.reserve(num_sections_to_defer);
1260 // Whether we've seen a .note.GNU-stack section.
1261 bool seen_gnu_stack = false;
1262 // The flags of a .note.GNU-stack section.
1263 uint64_t gnu_stack_flags = 0;
1265 // Keep track of which sections to omit.
1266 std::vector<bool> omit(shnum, false);
1268 // Keep track of reloc sections when emitting relocations.
1269 const bool relocatable = parameters->options().relocatable();
1270 const bool emit_relocs = (relocatable
1271 || parameters->options().emit_relocs());
1272 std::vector<unsigned int> reloc_sections;
1274 // Keep track of .eh_frame sections.
1275 std::vector<unsigned int> eh_frame_sections;
1277 // Skip the first, dummy, section.
1278 pshdrs = shdrs + This::shdr_size;
1279 for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
1281 typename This::Shdr shdr(pshdrs);
1283 if (shdr.get_sh_name() >= section_names_size)
1285 this->error(_("bad section name offset for section %u: %lu"),
1286 i, static_cast<unsigned long>(shdr.get_sh_name()));
1290 const char* name = pnames + shdr.get_sh_name();
1292 if (!is_gc_pass_two)
1294 if (this->handle_gnu_warning_section(name, i, symtab))
1296 if (!relocatable && !parameters->options().shared())
1300 // The .note.GNU-stack section is special. It gives the
1301 // protection flags that this object file requires for the stack
1303 if (strcmp(name, ".note.GNU-stack") == 0)
1305 seen_gnu_stack = true;
1306 gnu_stack_flags |= shdr.get_sh_flags();
1310 // The .note.GNU-split-stack section is also special. It
1311 // indicates that the object was compiled with
1313 if (this->handle_split_stack_section(name))
1315 if (!relocatable && !parameters->options().shared())
1319 // Skip attributes section.
1320 if (parameters->target().is_attributes_section(name))
1325 bool discard = omit[i];
1328 if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
1330 if (!this->include_section_group(symtab, layout, i, name,
1336 else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
1337 && Layout::is_linkonce(name))
1339 if (!this->include_linkonce_section(layout, i, name, shdr))
1344 // Add the section to the incremental inputs layout.
1345 Incremental_inputs* incremental_inputs = layout->incremental_inputs();
1346 if (incremental_inputs != NULL
1348 && (shdr.get_sh_type() == elfcpp::SHT_PROGBITS
1349 || shdr.get_sh_type() == elfcpp::SHT_NOBITS
1350 || shdr.get_sh_type() == elfcpp::SHT_NOTE))
1352 off_t sh_size = shdr.get_sh_size();
1353 section_size_type uncompressed_size;
1354 if (this->section_is_compressed(i, &uncompressed_size))
1355 sh_size = uncompressed_size;
1356 incremental_inputs->report_input_section(this, i, name, sh_size);
1361 // Do not include this section in the link.
1362 out_sections[i] = NULL;
1363 out_section_offsets[i] = invalid_address;
1368 if (is_gc_pass_one && parameters->options().gc_sections())
1370 if (this->is_section_name_included(name)
1371 || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1372 || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
1374 symtab->gc()->worklist().push(Section_id(this, i));
1376 // If the section name XXX can be represented as a C identifier
1377 // it cannot be discarded if there are references to
1378 // __start_XXX and __stop_XXX symbols. These need to be
1379 // specially handled.
1380 if (is_cident(name))
1382 symtab->gc()->add_cident_section(name, Section_id(this, i));
1386 // When doing a relocatable link we are going to copy input
1387 // reloc sections into the output. We only want to copy the
1388 // ones associated with sections which are not being discarded.
1389 // However, we don't know that yet for all sections. So save
1390 // reloc sections and process them later. Garbage collection is
1391 // not triggered when relocatable code is desired.
1393 && (shdr.get_sh_type() == elfcpp::SHT_REL
1394 || shdr.get_sh_type() == elfcpp::SHT_RELA))
1396 reloc_sections.push_back(i);
1400 if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
1403 // The .eh_frame section is special. It holds exception frame
1404 // information that we need to read in order to generate the
1405 // exception frame header. We process these after all the other
1406 // sections so that the exception frame reader can reliably
1407 // determine which sections are being discarded, and discard the
1408 // corresponding information.
1410 && strcmp(name, ".eh_frame") == 0
1411 && this->check_eh_frame_flags(&shdr))
1415 out_sections[i] = reinterpret_cast<Output_section*>(1);
1416 out_section_offsets[i] = invalid_address;
1418 else if (should_defer_layout)
1419 this->deferred_layout_.push_back(Deferred_layout(i, name,
1424 eh_frame_sections.push_back(i);
1428 if (is_gc_pass_two && parameters->options().gc_sections())
1430 // This is executed during the second pass of garbage
1431 // collection. do_layout has been called before and some
1432 // sections have been already discarded. Simply ignore
1433 // such sections this time around.
1434 if (out_sections[i] == NULL)
1436 gold_assert(out_section_offsets[i] == invalid_address);
1439 if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1440 && symtab->gc()->is_section_garbage(this, i))
1442 if (parameters->options().print_gc_sections())
1443 gold_info(_("%s: removing unused section from '%s'"
1445 program_name, this->section_name(i).c_str(),
1446 this->name().c_str());
1447 out_sections[i] = NULL;
1448 out_section_offsets[i] = invalid_address;
1453 if (is_gc_pass_two && parameters->options().icf_enabled())
1455 if (out_sections[i] == NULL)
1457 gold_assert(out_section_offsets[i] == invalid_address);
1460 if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
1461 && symtab->icf()->is_section_folded(this, i))
1463 if (parameters->options().print_icf_sections())
1466 symtab->icf()->get_folded_section(this, i);
1467 Relobj* folded_obj =
1468 reinterpret_cast<Relobj*>(folded.first);
1469 gold_info(_("%s: ICF folding section '%s' in file '%s'"
1470 "into '%s' in file '%s'"),
1471 program_name, this->section_name(i).c_str(),
1472 this->name().c_str(),
1473 folded_obj->section_name(folded.second).c_str(),
1474 folded_obj->name().c_str());
1476 out_sections[i] = NULL;
1477 out_section_offsets[i] = invalid_address;
1482 // Defer layout here if input files are claimed by plugins. When gc
1483 // is turned on this function is called twice. For the second call
1484 // should_defer_layout should be false.
1485 if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
1487 gold_assert(!is_gc_pass_two);
1488 this->deferred_layout_.push_back(Deferred_layout(i, name,
1492 // Put dummy values here; real values will be supplied by
1493 // do_layout_deferred_sections.
1494 out_sections[i] = reinterpret_cast<Output_section*>(2);
1495 out_section_offsets[i] = invalid_address;
1499 // During gc_pass_two if a section that was previously deferred is
1500 // found, do not layout the section as layout_deferred_sections will
1501 // do it later from gold.cc.
1503 && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
1508 // This is during garbage collection. The out_sections are
1509 // assigned in the second call to this function.
1510 out_sections[i] = reinterpret_cast<Output_section*>(1);
1511 out_section_offsets[i] = invalid_address;
1515 // When garbage collection is switched on the actual layout
1516 // only happens in the second call.
1517 this->layout_section(layout, i, name, shdr, reloc_shndx[i],
1522 if (!is_gc_pass_two)
1523 layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags, this);
1525 // When doing a relocatable link handle the reloc sections at the
1526 // end. Garbage collection and Identical Code Folding is not
1527 // turned on for relocatable code.
1529 this->size_relocatable_relocs();
1531 gold_assert(!(is_gc_or_icf) || reloc_sections.empty());
1533 for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
1534 p != reloc_sections.end();
1537 unsigned int i = *p;
1538 const unsigned char* pshdr;
1539 pshdr = section_headers_data + i * This::shdr_size;
1540 typename This::Shdr shdr(pshdr);
1542 unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1543 if (data_shndx >= shnum)
1545 // We already warned about this above.
1549 Output_section* data_section = out_sections[data_shndx];
1550 if (data_section == reinterpret_cast<Output_section*>(2))
1552 // The layout for the data section was deferred, so we need
1553 // to defer the relocation section, too.
1554 const char* name = pnames + shdr.get_sh_name();
1555 this->deferred_layout_relocs_.push_back(
1556 Deferred_layout(i, name, pshdr, 0, elfcpp::SHT_NULL));
1557 out_sections[i] = reinterpret_cast<Output_section*>(2);
1558 out_section_offsets[i] = invalid_address;
1561 if (data_section == NULL)
1563 out_sections[i] = NULL;
1564 out_section_offsets[i] = invalid_address;
1568 Relocatable_relocs* rr = new Relocatable_relocs();
1569 this->set_relocatable_relocs(i, rr);
1571 Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
1573 out_sections[i] = os;
1574 out_section_offsets[i] = invalid_address;
1577 // Handle the .eh_frame sections at the end.
1578 gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
1579 for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
1580 p != eh_frame_sections.end();
1583 gold_assert(external_symbols_offset != 0);
1585 unsigned int i = *p;
1586 const unsigned char* pshdr;
1587 pshdr = section_headers_data + i * This::shdr_size;
1588 typename This::Shdr shdr(pshdr);
1590 this->layout_eh_frame_section(layout,
1603 delete[] gc_sd->section_headers_data;
1604 delete[] gc_sd->section_names_data;
1605 delete[] gc_sd->symbols_data;
1606 delete[] gc_sd->symbol_names_data;
1607 this->set_symbols_data(NULL);
1611 delete sd->section_headers;
1612 sd->section_headers = NULL;
1613 delete sd->section_names;
1614 sd->section_names = NULL;
1618 // Layout sections whose layout was deferred while waiting for
1619 // input files from a plugin.
1621 template<int size, bool big_endian>
1623 Sized_relobj_file<size, big_endian>::do_layout_deferred_sections(Layout* layout)
1625 typename std::vector<Deferred_layout>::iterator deferred;
1627 for (deferred = this->deferred_layout_.begin();
1628 deferred != this->deferred_layout_.end();
1631 typename This::Shdr shdr(deferred->shdr_data_);
1632 // If the section is not included, it is because the garbage collector
1633 // decided it is not needed. Avoid reverting that decision.
1634 if (!this->is_section_included(deferred->shndx_))
1637 if (parameters->options().relocatable()
1638 || deferred->name_ != ".eh_frame"
1639 || !this->check_eh_frame_flags(&shdr))
1640 this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
1641 shdr, deferred->reloc_shndx_,
1642 deferred->reloc_type_);
1645 // Reading the symbols again here may be slow.
1646 Read_symbols_data sd;
1647 this->read_symbols(&sd);
1648 this->layout_eh_frame_section(layout,
1651 sd.symbol_names->data(),
1652 sd.symbol_names_size,
1655 deferred->reloc_shndx_,
1656 deferred->reloc_type_);
1660 this->deferred_layout_.clear();
1662 // Now handle the deferred relocation sections.
1664 Output_sections& out_sections(this->output_sections());
1665 std::vector<Address>& out_section_offsets(this->section_offsets());
1667 for (deferred = this->deferred_layout_relocs_.begin();
1668 deferred != this->deferred_layout_relocs_.end();
1671 unsigned int shndx = deferred->shndx_;
1672 typename This::Shdr shdr(deferred->shdr_data_);
1673 unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
1675 Output_section* data_section = out_sections[data_shndx];
1676 if (data_section == NULL)
1678 out_sections[shndx] = NULL;
1679 out_section_offsets[shndx] = invalid_address;
1683 Relocatable_relocs* rr = new Relocatable_relocs();
1684 this->set_relocatable_relocs(shndx, rr);
1686 Output_section* os = layout->layout_reloc(this, shndx, shdr,
1688 out_sections[shndx] = os;
1689 out_section_offsets[shndx] = invalid_address;
1693 // Add the symbols to the symbol table.
1695 template<int size, bool big_endian>
1697 Sized_relobj_file<size, big_endian>::do_add_symbols(Symbol_table* symtab,
1698 Read_symbols_data* sd,
1701 if (sd->symbols == NULL)
1703 gold_assert(sd->symbol_names == NULL);
1707 const int sym_size = This::sym_size;
1708 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1710 if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
1712 this->error(_("size of symbols is not multiple of symbol size"));
1716 this->symbols_.resize(symcount);
1718 const char* sym_names =
1719 reinterpret_cast<const char*>(sd->symbol_names->data());
1720 symtab->add_from_relobj(this,
1721 sd->symbols->data() + sd->external_symbols_offset,
1722 symcount, this->local_symbol_count_,
1723 sym_names, sd->symbol_names_size,
1725 &this->defined_count_);
1729 delete sd->symbol_names;
1730 sd->symbol_names = NULL;
1733 // Find out if this object, that is a member of a lib group, should be included
1734 // in the link. We check every symbol defined by this object. If the symbol
1735 // table has a strong undefined reference to that symbol, we have to include
1738 template<int size, bool big_endian>
1739 Archive::Should_include
1740 Sized_relobj_file<size, big_endian>::do_should_include_member(
1741 Symbol_table* symtab,
1743 Read_symbols_data* sd,
1746 char* tmpbuf = NULL;
1747 size_t tmpbuflen = 0;
1748 const char* sym_names =
1749 reinterpret_cast<const char*>(sd->symbol_names->data());
1750 const unsigned char* syms =
1751 sd->symbols->data() + sd->external_symbols_offset;
1752 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1753 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1756 const unsigned char* p = syms;
1758 for (size_t i = 0; i < symcount; ++i, p += sym_size)
1760 elfcpp::Sym<size, big_endian> sym(p);
1761 unsigned int st_shndx = sym.get_st_shndx();
1762 if (st_shndx == elfcpp::SHN_UNDEF)
1765 unsigned int st_name = sym.get_st_name();
1766 const char* name = sym_names + st_name;
1768 Archive::Should_include t = Archive::should_include_member(symtab,
1774 if (t == Archive::SHOULD_INCLUDE_YES)
1783 return Archive::SHOULD_INCLUDE_UNKNOWN;
1786 // Iterate over global defined symbols, calling a visitor class V for each.
1788 template<int size, bool big_endian>
1790 Sized_relobj_file<size, big_endian>::do_for_all_global_symbols(
1791 Read_symbols_data* sd,
1792 Library_base::Symbol_visitor_base* v)
1794 const char* sym_names =
1795 reinterpret_cast<const char*>(sd->symbol_names->data());
1796 const unsigned char* syms =
1797 sd->symbols->data() + sd->external_symbols_offset;
1798 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1799 size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
1801 const unsigned char* p = syms;
1803 for (size_t i = 0; i < symcount; ++i, p += sym_size)
1805 elfcpp::Sym<size, big_endian> sym(p);
1806 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF)
1807 v->visit(sym_names + sym.get_st_name());
1811 // Return whether the local symbol SYMNDX has a PLT offset.
1813 template<int size, bool big_endian>
1815 Sized_relobj_file<size, big_endian>::local_has_plt_offset(
1816 unsigned int symndx) const
1818 typename Local_plt_offsets::const_iterator p =
1819 this->local_plt_offsets_.find(symndx);
1820 return p != this->local_plt_offsets_.end();
1823 // Get the PLT offset of a local symbol.
1825 template<int size, bool big_endian>
1827 Sized_relobj_file<size, big_endian>::local_plt_offset(unsigned int symndx) const
1829 typename Local_plt_offsets::const_iterator p =
1830 this->local_plt_offsets_.find(symndx);
1831 gold_assert(p != this->local_plt_offsets_.end());
1835 // Set the PLT offset of a local symbol.
1837 template<int size, bool big_endian>
1839 Sized_relobj_file<size, big_endian>::set_local_plt_offset(
1840 unsigned int symndx, unsigned int plt_offset)
1842 std::pair<typename Local_plt_offsets::iterator, bool> ins =
1843 this->local_plt_offsets_.insert(std::make_pair(symndx, plt_offset));
1844 gold_assert(ins.second);
1847 // First pass over the local symbols. Here we add their names to
1848 // *POOL and *DYNPOOL, and we store the symbol value in
1849 // THIS->LOCAL_VALUES_. This function is always called from a
1850 // singleton thread. This is followed by a call to
1851 // finalize_local_symbols.
1853 template<int size, bool big_endian>
1855 Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
1856 Stringpool* dynpool)
1858 gold_assert(this->symtab_shndx_ != -1U);
1859 if (this->symtab_shndx_ == 0)
1861 // This object has no symbols. Weird but legal.
1865 // Read the symbol table section header.
1866 const unsigned int symtab_shndx = this->symtab_shndx_;
1867 typename This::Shdr symtabshdr(this,
1868 this->elf_file_.section_header(symtab_shndx));
1869 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
1871 // Read the local symbols.
1872 const int sym_size = This::sym_size;
1873 const unsigned int loccount = this->local_symbol_count_;
1874 gold_assert(loccount == symtabshdr.get_sh_info());
1875 off_t locsize = loccount * sym_size;
1876 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
1877 locsize, true, true);
1879 // Read the symbol names.
1880 const unsigned int strtab_shndx =
1881 this->adjust_shndx(symtabshdr.get_sh_link());
1882 section_size_type strtab_size;
1883 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
1886 const char* pnames = reinterpret_cast<const char*>(pnamesu);
1888 // Loop over the local symbols.
1890 const Output_sections& out_sections(this->output_sections());
1891 unsigned int shnum = this->shnum();
1892 unsigned int count = 0;
1893 unsigned int dyncount = 0;
1894 // Skip the first, dummy, symbol.
1896 bool strip_all = parameters->options().strip_all();
1897 bool discard_all = parameters->options().discard_all();
1898 bool discard_locals = parameters->options().discard_locals();
1899 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
1901 elfcpp::Sym<size, big_endian> sym(psyms);
1903 Symbol_value<size>& lv(this->local_values_[i]);
1906 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
1908 lv.set_input_shndx(shndx, is_ordinary);
1910 if (sym.get_st_type() == elfcpp::STT_SECTION)
1911 lv.set_is_section_symbol();
1912 else if (sym.get_st_type() == elfcpp::STT_TLS)
1913 lv.set_is_tls_symbol();
1914 else if (sym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1915 lv.set_is_ifunc_symbol();
1917 // Save the input symbol value for use in do_finalize_local_symbols().
1918 lv.set_input_value(sym.get_st_value());
1920 // Decide whether this symbol should go into the output file.
1922 if ((shndx < shnum && out_sections[shndx] == NULL)
1923 || shndx == this->discarded_eh_frame_shndx_)
1925 lv.set_no_output_symtab_entry();
1926 gold_assert(!lv.needs_output_dynsym_entry());
1930 if (sym.get_st_type() == elfcpp::STT_SECTION)
1932 lv.set_no_output_symtab_entry();
1933 gold_assert(!lv.needs_output_dynsym_entry());
1937 if (sym.get_st_name() >= strtab_size)
1939 this->error(_("local symbol %u section name out of range: %u >= %u"),
1940 i, sym.get_st_name(),
1941 static_cast<unsigned int>(strtab_size));
1942 lv.set_no_output_symtab_entry();
1946 const char* name = pnames + sym.get_st_name();
1948 // If needed, add the symbol to the dynamic symbol table string pool.
1949 if (lv.needs_output_dynsym_entry())
1951 dynpool->add(name, true, NULL);
1956 || (discard_all && lv.may_be_discarded_from_output_symtab()))
1958 lv.set_no_output_symtab_entry();
1962 // If --discard-locals option is used, discard all temporary local
1963 // symbols. These symbols start with system-specific local label
1964 // prefixes, typically .L for ELF system. We want to be compatible
1965 // with GNU ld so here we essentially use the same check in
1966 // bfd_is_local_label(). The code is different because we already
1969 // - the symbol is local and thus cannot have global or weak binding.
1970 // - the symbol is not a section symbol.
1971 // - the symbol has a name.
1973 // We do not discard a symbol if it needs a dynamic symbol entry.
1975 && sym.get_st_type() != elfcpp::STT_FILE
1976 && !lv.needs_output_dynsym_entry()
1977 && lv.may_be_discarded_from_output_symtab()
1978 && parameters->target().is_local_label_name(name))
1980 lv.set_no_output_symtab_entry();
1984 // Discard the local symbol if -retain_symbols_file is specified
1985 // and the local symbol is not in that file.
1986 if (!parameters->options().should_retain_symbol(name))
1988 lv.set_no_output_symtab_entry();
1992 // Add the symbol to the symbol table string pool.
1993 pool->add(name, true, NULL);
1997 this->output_local_symbol_count_ = count;
1998 this->output_local_dynsym_count_ = dyncount;
2001 // Compute the final value of a local symbol.
2003 template<int size, bool big_endian>
2004 typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2005 Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
2007 const Symbol_value<size>* lv_in,
2008 Symbol_value<size>* lv_out,
2010 const Output_sections& out_sections,
2011 const std::vector<Address>& out_offsets,
2012 const Symbol_table* symtab)
2014 // We are going to overwrite *LV_OUT, if it has a merged symbol value,
2015 // we may have a memory leak.
2016 gold_assert(lv_out->has_output_value());
2019 unsigned int shndx = lv_in->input_shndx(&is_ordinary);
2021 // Set the output symbol value.
2025 if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
2026 lv_out->set_output_value(lv_in->input_value());
2029 this->error(_("unknown section index %u for local symbol %u"),
2031 lv_out->set_output_value(0);
2032 return This::CFLV_ERROR;
2037 if (shndx >= this->shnum())
2039 this->error(_("local symbol %u section index %u out of range"),
2041 lv_out->set_output_value(0);
2042 return This::CFLV_ERROR;
2045 Output_section* os = out_sections[shndx];
2046 Address secoffset = out_offsets[shndx];
2047 if (symtab->is_section_folded(this, shndx))
2049 gold_assert(os == NULL && secoffset == invalid_address);
2050 // Get the os of the section it is folded onto.
2051 Section_id folded = symtab->icf()->get_folded_section(this,
2053 gold_assert(folded.first != NULL);
2054 Sized_relobj_file<size, big_endian>* folded_obj = reinterpret_cast
2055 <Sized_relobj_file<size, big_endian>*>(folded.first);
2056 os = folded_obj->output_section(folded.second);
2057 gold_assert(os != NULL);
2058 secoffset = folded_obj->get_output_section_offset(folded.second);
2060 // This could be a relaxed input section.
2061 if (secoffset == invalid_address)
2063 const Output_relaxed_input_section* relaxed_section =
2064 os->find_relaxed_input_section(folded_obj, folded.second);
2065 gold_assert(relaxed_section != NULL);
2066 secoffset = relaxed_section->address() - os->address();
2072 // This local symbol belongs to a section we are discarding.
2073 // In some cases when applying relocations later, we will
2074 // attempt to match it to the corresponding kept section,
2075 // so we leave the input value unchanged here.
2076 return This::CFLV_DISCARDED;
2078 else if (secoffset == invalid_address)
2082 // This is a SHF_MERGE section or one which otherwise
2083 // requires special handling.
2084 if (shndx == this->discarded_eh_frame_shndx_)
2086 // This local symbol belongs to a discarded .eh_frame
2087 // section. Just treat it like the case in which
2088 // os == NULL above.
2089 gold_assert(this->has_eh_frame_);
2090 return This::CFLV_DISCARDED;
2092 else if (!lv_in->is_section_symbol())
2094 // This is not a section symbol. We can determine
2095 // the final value now.
2096 lv_out->set_output_value(
2097 os->output_address(this, shndx, lv_in->input_value()));
2099 else if (!os->find_starting_output_address(this, shndx, &start))
2101 // This is a section symbol, but apparently not one in a
2102 // merged section. First check to see if this is a relaxed
2103 // input section. If so, use its address. Otherwise just
2104 // use the start of the output section. This happens with
2105 // relocatable links when the input object has section
2106 // symbols for arbitrary non-merge sections.
2107 const Output_section_data* posd =
2108 os->find_relaxed_input_section(this, shndx);
2111 Address relocatable_link_adjustment =
2112 relocatable ? os->address() : 0;
2113 lv_out->set_output_value(posd->address()
2114 - relocatable_link_adjustment);
2117 lv_out->set_output_value(os->address());
2121 // We have to consider the addend to determine the
2122 // value to use in a relocation. START is the start
2123 // of this input section. If we are doing a relocatable
2124 // link, use offset from start output section instead of
2126 Address adjusted_start =
2127 relocatable ? start - os->address() : start;
2128 Merged_symbol_value<size>* msv =
2129 new Merged_symbol_value<size>(lv_in->input_value(),
2131 lv_out->set_merged_symbol_value(msv);
2134 else if (lv_in->is_tls_symbol())
2135 lv_out->set_output_value(os->tls_offset()
2137 + lv_in->input_value());
2139 lv_out->set_output_value((relocatable ? 0 : os->address())
2141 + lv_in->input_value());
2143 return This::CFLV_OK;
2146 // Compute final local symbol value. R_SYM is the index of a local
2147 // symbol in symbol table. LV points to a symbol value, which is
2148 // expected to hold the input value and to be over-written by the
2149 // final value. SYMTAB points to a symbol table. Some targets may want
2150 // to know would-be-finalized local symbol values in relaxation.
2151 // Hence we provide this method. Since this method updates *LV, a
2152 // callee should make a copy of the original local symbol value and
2153 // use the copy instead of modifying an object's local symbols before
2154 // everything is finalized. The caller should also free up any allocated
2155 // memory in the return value in *LV.
2156 template<int size, bool big_endian>
2157 typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
2158 Sized_relobj_file<size, big_endian>::compute_final_local_value(
2160 const Symbol_value<size>* lv_in,
2161 Symbol_value<size>* lv_out,
2162 const Symbol_table* symtab)
2164 // This is just a wrapper of compute_final_local_value_internal.
2165 const bool relocatable = parameters->options().relocatable();
2166 const Output_sections& out_sections(this->output_sections());
2167 const std::vector<Address>& out_offsets(this->section_offsets());
2168 return this->compute_final_local_value_internal(r_sym, lv_in, lv_out,
2169 relocatable, out_sections,
2170 out_offsets, symtab);
2173 // Finalize the local symbols. Here we set the final value in
2174 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
2175 // This function is always called from a singleton thread. The actual
2176 // output of the local symbols will occur in a separate task.
2178 template<int size, bool big_endian>
2180 Sized_relobj_file<size, big_endian>::do_finalize_local_symbols(
2183 Symbol_table* symtab)
2185 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2187 const unsigned int loccount = this->local_symbol_count_;
2188 this->local_symbol_offset_ = off;
2190 const bool relocatable = parameters->options().relocatable();
2191 const Output_sections& out_sections(this->output_sections());
2192 const std::vector<Address>& out_offsets(this->section_offsets());
2194 for (unsigned int i = 1; i < loccount; ++i)
2196 Symbol_value<size>* lv = &this->local_values_[i];
2198 Compute_final_local_value_status cflv_status =
2199 this->compute_final_local_value_internal(i, lv, lv, relocatable,
2200 out_sections, out_offsets,
2202 switch (cflv_status)
2205 if (!lv->is_output_symtab_index_set())
2207 lv->set_output_symtab_index(index);
2211 case CFLV_DISCARDED:
2222 // Set the output dynamic symbol table indexes for the local variables.
2224 template<int size, bool big_endian>
2226 Sized_relobj_file<size, big_endian>::do_set_local_dynsym_indexes(
2229 const unsigned int loccount = this->local_symbol_count_;
2230 for (unsigned int i = 1; i < loccount; ++i)
2232 Symbol_value<size>& lv(this->local_values_[i]);
2233 if (lv.needs_output_dynsym_entry())
2235 lv.set_output_dynsym_index(index);
2242 // Set the offset where local dynamic symbol information will be stored.
2243 // Returns the count of local symbols contributed to the symbol table by
2246 template<int size, bool big_endian>
2248 Sized_relobj_file<size, big_endian>::do_set_local_dynsym_offset(off_t off)
2250 gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
2251 this->local_dynsym_offset_ = off;
2252 return this->output_local_dynsym_count_;
2255 // If Symbols_data is not NULL get the section flags from here otherwise
2256 // get it from the file.
2258 template<int size, bool big_endian>
2260 Sized_relobj_file<size, big_endian>::do_section_flags(unsigned int shndx)
2262 Symbols_data* sd = this->get_symbols_data();
2265 const unsigned char* pshdrs = sd->section_headers_data
2266 + This::shdr_size * shndx;
2267 typename This::Shdr shdr(pshdrs);
2268 return shdr.get_sh_flags();
2270 // If sd is NULL, read the section header from the file.
2271 return this->elf_file_.section_flags(shndx);
2274 // Get the section's ent size from Symbols_data. Called by get_section_contents
2277 template<int size, bool big_endian>
2279 Sized_relobj_file<size, big_endian>::do_section_entsize(unsigned int shndx)
2281 Symbols_data* sd = this->get_symbols_data();
2282 gold_assert(sd != NULL);
2284 const unsigned char* pshdrs = sd->section_headers_data
2285 + This::shdr_size * shndx;
2286 typename This::Shdr shdr(pshdrs);
2287 return shdr.get_sh_entsize();
2290 // Write out the local symbols.
2292 template<int size, bool big_endian>
2294 Sized_relobj_file<size, big_endian>::write_local_symbols(
2296 const Stringpool* sympool,
2297 const Stringpool* dynpool,
2298 Output_symtab_xindex* symtab_xindex,
2299 Output_symtab_xindex* dynsym_xindex,
2302 const bool strip_all = parameters->options().strip_all();
2305 if (this->output_local_dynsym_count_ == 0)
2307 this->output_local_symbol_count_ = 0;
2310 gold_assert(this->symtab_shndx_ != -1U);
2311 if (this->symtab_shndx_ == 0)
2313 // This object has no symbols. Weird but legal.
2317 // Read the symbol table section header.
2318 const unsigned int symtab_shndx = this->symtab_shndx_;
2319 typename This::Shdr symtabshdr(this,
2320 this->elf_file_.section_header(symtab_shndx));
2321 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
2322 const unsigned int loccount = this->local_symbol_count_;
2323 gold_assert(loccount == symtabshdr.get_sh_info());
2325 // Read the local symbols.
2326 const int sym_size = This::sym_size;
2327 off_t locsize = loccount * sym_size;
2328 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
2329 locsize, true, false);
2331 // Read the symbol names.
2332 const unsigned int strtab_shndx =
2333 this->adjust_shndx(symtabshdr.get_sh_link());
2334 section_size_type strtab_size;
2335 const unsigned char* pnamesu = this->section_contents(strtab_shndx,
2338 const char* pnames = reinterpret_cast<const char*>(pnamesu);
2340 // Get views into the output file for the portions of the symbol table
2341 // and the dynamic symbol table that we will be writing.
2342 off_t output_size = this->output_local_symbol_count_ * sym_size;
2343 unsigned char* oview = NULL;
2344 if (output_size > 0)
2345 oview = of->get_output_view(symtab_off + this->local_symbol_offset_,
2348 off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
2349 unsigned char* dyn_oview = NULL;
2350 if (dyn_output_size > 0)
2351 dyn_oview = of->get_output_view(this->local_dynsym_offset_,
2354 const Output_sections out_sections(this->output_sections());
2356 gold_assert(this->local_values_.size() == loccount);
2358 unsigned char* ov = oview;
2359 unsigned char* dyn_ov = dyn_oview;
2361 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
2363 elfcpp::Sym<size, big_endian> isym(psyms);
2365 Symbol_value<size>& lv(this->local_values_[i]);
2368 unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
2372 gold_assert(st_shndx < out_sections.size());
2373 if (out_sections[st_shndx] == NULL)
2375 st_shndx = out_sections[st_shndx]->out_shndx();
2376 if (st_shndx >= elfcpp::SHN_LORESERVE)
2378 if (lv.has_output_symtab_entry())
2379 symtab_xindex->add(lv.output_symtab_index(), st_shndx);
2380 if (lv.has_output_dynsym_entry())
2381 dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
2382 st_shndx = elfcpp::SHN_XINDEX;
2386 // Write the symbol to the output symbol table.
2387 if (lv.has_output_symtab_entry())
2389 elfcpp::Sym_write<size, big_endian> osym(ov);
2391 gold_assert(isym.get_st_name() < strtab_size);
2392 const char* name = pnames + isym.get_st_name();
2393 osym.put_st_name(sympool->get_offset(name));
2394 osym.put_st_value(this->local_values_[i].value(this, 0));
2395 osym.put_st_size(isym.get_st_size());
2396 osym.put_st_info(isym.get_st_info());
2397 osym.put_st_other(isym.get_st_other());
2398 osym.put_st_shndx(st_shndx);
2403 // Write the symbol to the output dynamic symbol table.
2404 if (lv.has_output_dynsym_entry())
2406 gold_assert(dyn_ov < dyn_oview + dyn_output_size);
2407 elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
2409 gold_assert(isym.get_st_name() < strtab_size);
2410 const char* name = pnames + isym.get_st_name();
2411 osym.put_st_name(dynpool->get_offset(name));
2412 osym.put_st_value(this->local_values_[i].value(this, 0));
2413 osym.put_st_size(isym.get_st_size());
2414 osym.put_st_info(isym.get_st_info());
2415 osym.put_st_other(isym.get_st_other());
2416 osym.put_st_shndx(st_shndx);
2423 if (output_size > 0)
2425 gold_assert(ov - oview == output_size);
2426 of->write_output_view(symtab_off + this->local_symbol_offset_,
2427 output_size, oview);
2430 if (dyn_output_size > 0)
2432 gold_assert(dyn_ov - dyn_oview == dyn_output_size);
2433 of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
2438 // Set *INFO to symbolic information about the offset OFFSET in the
2439 // section SHNDX. Return true if we found something, false if we
2442 template<int size, bool big_endian>
2444 Sized_relobj_file<size, big_endian>::get_symbol_location_info(
2447 Symbol_location_info* info)
2449 if (this->symtab_shndx_ == 0)
2452 section_size_type symbols_size;
2453 const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
2457 unsigned int symbol_names_shndx =
2458 this->adjust_shndx(this->section_link(this->symtab_shndx_));
2459 section_size_type names_size;
2460 const unsigned char* symbol_names_u =
2461 this->section_contents(symbol_names_shndx, &names_size, false);
2462 const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
2464 const int sym_size = This::sym_size;
2465 const size_t count = symbols_size / sym_size;
2467 const unsigned char* p = symbols;
2468 for (size_t i = 0; i < count; ++i, p += sym_size)
2470 elfcpp::Sym<size, big_endian> sym(p);
2472 if (sym.get_st_type() == elfcpp::STT_FILE)
2474 if (sym.get_st_name() >= names_size)
2475 info->source_file = "(invalid)";
2477 info->source_file = symbol_names + sym.get_st_name();
2482 unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
2485 && st_shndx == shndx
2486 && static_cast<off_t>(sym.get_st_value()) <= offset
2487 && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
2490 if (sym.get_st_name() > names_size)
2491 info->enclosing_symbol_name = "(invalid)";
2494 info->enclosing_symbol_name = symbol_names + sym.get_st_name();
2495 if (parameters->options().do_demangle())
2497 char* demangled_name = cplus_demangle(
2498 info->enclosing_symbol_name.c_str(),
2499 DMGL_ANSI | DMGL_PARAMS);
2500 if (demangled_name != NULL)
2502 info->enclosing_symbol_name.assign(demangled_name);
2503 free(demangled_name);
2514 // Look for a kept section corresponding to the given discarded section,
2515 // and return its output address. This is used only for relocations in
2516 // debugging sections. If we can't find the kept section, return 0.
2518 template<int size, bool big_endian>
2519 typename Sized_relobj_file<size, big_endian>::Address
2520 Sized_relobj_file<size, big_endian>::map_to_kept_section(
2524 Relobj* kept_object;
2525 unsigned int kept_shndx;
2526 if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
2528 Sized_relobj_file<size, big_endian>* kept_relobj =
2529 static_cast<Sized_relobj_file<size, big_endian>*>(kept_object);
2530 Output_section* os = kept_relobj->output_section(kept_shndx);
2531 Address offset = kept_relobj->get_output_section_offset(kept_shndx);
2532 if (os != NULL && offset != invalid_address)
2535 return os->address() + offset;
2542 // Get symbol counts.
2544 template<int size, bool big_endian>
2546 Sized_relobj_file<size, big_endian>::do_get_global_symbol_counts(
2547 const Symbol_table*,
2551 *defined = this->defined_count_;
2553 for (typename Symbols::const_iterator p = this->symbols_.begin();
2554 p != this->symbols_.end();
2557 && (*p)->source() == Symbol::FROM_OBJECT
2558 && (*p)->object() == this
2559 && (*p)->is_defined())
2564 // Input_objects methods.
2566 // Add a regular relocatable object to the list. Return false if this
2567 // object should be ignored.
2570 Input_objects::add_object(Object* obj)
2572 // Print the filename if the -t/--trace option is selected.
2573 if (parameters->options().trace())
2574 gold_info("%s", obj->name().c_str());
2576 if (!obj->is_dynamic())
2577 this->relobj_list_.push_back(static_cast<Relobj*>(obj));
2580 // See if this is a duplicate SONAME.
2581 Dynobj* dynobj = static_cast<Dynobj*>(obj);
2582 const char* soname = dynobj->soname();
2584 std::pair<Unordered_set<std::string>::iterator, bool> ins =
2585 this->sonames_.insert(soname);
2588 // We have already seen a dynamic object with this soname.
2592 this->dynobj_list_.push_back(dynobj);
2595 // Add this object to the cross-referencer if requested.
2596 if (parameters->options().user_set_print_symbol_counts()
2597 || parameters->options().cref())
2599 if (this->cref_ == NULL)
2600 this->cref_ = new Cref();
2601 this->cref_->add_object(obj);
2607 // For each dynamic object, record whether we've seen all of its
2608 // explicit dependencies.
2611 Input_objects::check_dynamic_dependencies() const
2613 bool issued_copy_dt_needed_error = false;
2614 for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
2615 p != this->dynobj_list_.end();
2618 const Dynobj::Needed& needed((*p)->needed());
2619 bool found_all = true;
2620 Dynobj::Needed::const_iterator pneeded;
2621 for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
2623 if (this->sonames_.find(*pneeded) == this->sonames_.end())
2629 (*p)->set_has_unknown_needed_entries(!found_all);
2631 // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2632 // that gold does not support. However, they cause no trouble
2633 // unless there is a DT_NEEDED entry that we don't know about;
2634 // warn only in that case.
2636 && !issued_copy_dt_needed_error
2637 && (parameters->options().copy_dt_needed_entries()
2638 || parameters->options().add_needed()))
2640 const char* optname;
2641 if (parameters->options().copy_dt_needed_entries())
2642 optname = "--copy-dt-needed-entries";
2644 optname = "--add-needed";
2645 gold_error(_("%s is not supported but is required for %s in %s"),
2646 optname, (*pneeded).c_str(), (*p)->name().c_str());
2647 issued_copy_dt_needed_error = true;
2652 // Start processing an archive.
2655 Input_objects::archive_start(Archive* archive)
2657 if (parameters->options().user_set_print_symbol_counts()
2658 || parameters->options().cref())
2660 if (this->cref_ == NULL)
2661 this->cref_ = new Cref();
2662 this->cref_->add_archive_start(archive);
2666 // Stop processing an archive.
2669 Input_objects::archive_stop(Archive* archive)
2671 if (parameters->options().user_set_print_symbol_counts()
2672 || parameters->options().cref())
2673 this->cref_->add_archive_stop(archive);
2676 // Print symbol counts
2679 Input_objects::print_symbol_counts(const Symbol_table* symtab) const
2681 if (parameters->options().user_set_print_symbol_counts()
2682 && this->cref_ != NULL)
2683 this->cref_->print_symbol_counts(symtab);
2686 // Print a cross reference table.
2689 Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const
2691 if (parameters->options().cref() && this->cref_ != NULL)
2692 this->cref_->print_cref(symtab, f);
2695 // Relocate_info methods.
2697 // Return a string describing the location of a relocation when file
2698 // and lineno information is not available. This is only used in
2701 template<int size, bool big_endian>
2703 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
2705 Sized_dwarf_line_info<size, big_endian> line_info(this->object);
2706 std::string ret = line_info.addr2line(this->data_shndx, offset, NULL);
2710 ret = this->object->name();
2712 Symbol_location_info info;
2713 if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
2715 if (!info.source_file.empty())
2718 ret += info.source_file;
2720 size_t len = info.enclosing_symbol_name.length() + 100;
2721 char* buf = new char[len];
2722 snprintf(buf, len, _(":function %s"),
2723 info.enclosing_symbol_name.c_str());
2730 ret += this->object->section_name(this->data_shndx);
2732 snprintf(buf, sizeof buf, "+0x%lx)", static_cast<long>(offset));
2737 } // End namespace gold.
2742 using namespace gold;
2744 // Read an ELF file with the header and return the appropriate
2745 // instance of Object.
2747 template<int size, bool big_endian>
2749 make_elf_sized_object(const std::string& name, Input_file* input_file,
2750 off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
2751 bool* punconfigured)
2753 Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
2754 ehdr.get_e_ident()[elfcpp::EI_OSABI],
2755 ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
2757 gold_fatal(_("%s: unsupported ELF machine number %d"),
2758 name.c_str(), ehdr.get_e_machine());
2760 if (!parameters->target_valid())
2761 set_parameters_target(target);
2762 else if (target != ¶meters->target())
2764 if (punconfigured != NULL)
2765 *punconfigured = true;
2767 gold_error(_("%s: incompatible target"), name.c_str());
2771 return target->make_elf_object<size, big_endian>(name, input_file, offset,
2775 } // End anonymous namespace.
2780 // Return whether INPUT_FILE is an ELF object.
2783 is_elf_object(Input_file* input_file, off_t offset,
2784 const unsigned char** start, int* read_size)
2786 off_t filesize = input_file->file().filesize();
2787 int want = elfcpp::Elf_recognizer::max_header_size;
2788 if (filesize - offset < want)
2789 want = filesize - offset;
2791 const unsigned char* p = input_file->file().get_view(offset, 0, want,
2796 return elfcpp::Elf_recognizer::is_elf_file(p, want);
2799 // Read an ELF file and return the appropriate instance of Object.
2802 make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
2803 const unsigned char* p, section_offset_type bytes,
2804 bool* punconfigured)
2806 if (punconfigured != NULL)
2807 *punconfigured = false;
2810 bool big_endian = false;
2812 if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
2813 &big_endian, &error))
2815 gold_error(_("%s: %s"), name.c_str(), error.c_str());
2823 #ifdef HAVE_TARGET_32_BIG
2824 elfcpp::Ehdr<32, true> ehdr(p);
2825 return make_elf_sized_object<32, true>(name, input_file,
2826 offset, ehdr, punconfigured);
2828 if (punconfigured != NULL)
2829 *punconfigured = true;
2831 gold_error(_("%s: not configured to support "
2832 "32-bit big-endian object"),
2839 #ifdef HAVE_TARGET_32_LITTLE
2840 elfcpp::Ehdr<32, false> ehdr(p);
2841 return make_elf_sized_object<32, false>(name, input_file,
2842 offset, ehdr, punconfigured);
2844 if (punconfigured != NULL)
2845 *punconfigured = true;
2847 gold_error(_("%s: not configured to support "
2848 "32-bit little-endian object"),
2854 else if (size == 64)
2858 #ifdef HAVE_TARGET_64_BIG
2859 elfcpp::Ehdr<64, true> ehdr(p);
2860 return make_elf_sized_object<64, true>(name, input_file,
2861 offset, ehdr, punconfigured);
2863 if (punconfigured != NULL)
2864 *punconfigured = true;
2866 gold_error(_("%s: not configured to support "
2867 "64-bit big-endian object"),
2874 #ifdef HAVE_TARGET_64_LITTLE
2875 elfcpp::Ehdr<64, false> ehdr(p);
2876 return make_elf_sized_object<64, false>(name, input_file,
2877 offset, ehdr, punconfigured);
2879 if (punconfigured != NULL)
2880 *punconfigured = true;
2882 gold_error(_("%s: not configured to support "
2883 "64-bit little-endian object"),
2893 // Instantiate the templates we need.
2895 #ifdef HAVE_TARGET_32_LITTLE
2898 Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
2899 Read_symbols_data*);
2902 #ifdef HAVE_TARGET_32_BIG
2905 Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
2906 Read_symbols_data*);
2909 #ifdef HAVE_TARGET_64_LITTLE
2912 Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
2913 Read_symbols_data*);
2916 #ifdef HAVE_TARGET_64_BIG
2919 Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
2920 Read_symbols_data*);
2923 #ifdef HAVE_TARGET_32_LITTLE
2925 class Sized_relobj_file<32, false>;
2928 #ifdef HAVE_TARGET_32_BIG
2930 class Sized_relobj_file<32, true>;
2933 #ifdef HAVE_TARGET_64_LITTLE
2935 class Sized_relobj_file<64, false>;
2938 #ifdef HAVE_TARGET_64_BIG
2940 class Sized_relobj_file<64, true>;
2943 #ifdef HAVE_TARGET_32_LITTLE
2945 struct Relocate_info<32, false>;
2948 #ifdef HAVE_TARGET_32_BIG
2950 struct Relocate_info<32, true>;
2953 #ifdef HAVE_TARGET_64_LITTLE
2955 struct Relocate_info<64, false>;
2958 #ifdef HAVE_TARGET_64_BIG
2960 struct Relocate_info<64, true>;
2963 #ifdef HAVE_TARGET_32_LITTLE
2966 Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int);
2970 Xindex::read_symtab_xindex<32, false>(Object*, unsigned int,
2971 const unsigned char*);
2974 #ifdef HAVE_TARGET_32_BIG
2977 Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int);
2981 Xindex::read_symtab_xindex<32, true>(Object*, unsigned int,
2982 const unsigned char*);
2985 #ifdef HAVE_TARGET_64_LITTLE
2988 Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int);
2992 Xindex::read_symtab_xindex<64, false>(Object*, unsigned int,
2993 const unsigned char*);
2996 #ifdef HAVE_TARGET_64_BIG
2999 Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int);
3003 Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
3004 const unsigned char*);
3007 } // End namespace gold.