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 return (shdr
->get_sh_type() == elfcpp::SHT_PROGBITS
515 && (shdr
->get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
518 // Return whether there is a GNU .eh_frame section, given the section
519 // headers and the section names.
521 template<int size
, bool big_endian
>
523 Sized_relobj_file
<size
, big_endian
>::find_eh_frame(
524 const unsigned char* pshdrs
,
526 section_size_type names_size
) const
528 const unsigned int shnum
= this->shnum();
529 const unsigned char* p
= pshdrs
+ This::shdr_size
;
530 for (unsigned int i
= 1; i
< shnum
; ++i
, p
+= This::shdr_size
)
532 typename
This::Shdr
shdr(p
);
533 if (this->check_eh_frame_flags(&shdr
))
535 if (shdr
.get_sh_name() >= names_size
)
537 this->error(_("bad section name offset for section %u: %lu"),
538 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
542 const char* name
= names
+ shdr
.get_sh_name();
543 if (strcmp(name
, ".eh_frame") == 0)
550 // Build a table for any compressed debug sections, mapping each section index
551 // to the uncompressed size.
553 template<int size
, bool big_endian
>
554 Compressed_section_map
*
555 build_compressed_section_map(
556 const unsigned char* pshdrs
,
559 section_size_type names_size
,
560 Sized_relobj_file
<size
, big_endian
>* obj
)
562 Compressed_section_map
* uncompressed_sizes
= new Compressed_section_map();
563 const unsigned int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
564 const unsigned char* p
= pshdrs
+ shdr_size
;
565 for (unsigned int i
= 1; i
< shnum
; ++i
, p
+= shdr_size
)
567 typename
elfcpp::Shdr
<size
, big_endian
> shdr(p
);
568 if (shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
569 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
571 if (shdr
.get_sh_name() >= names_size
)
573 obj
->error(_("bad section name offset for section %u: %lu"),
574 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
578 const char* name
= names
+ shdr
.get_sh_name();
579 if (is_compressed_debug_section(name
))
581 section_size_type len
;
582 const unsigned char* contents
=
583 obj
->section_contents(i
, &len
, false);
584 uint64_t uncompressed_size
= get_uncompressed_size(contents
, len
);
585 if (uncompressed_size
!= -1ULL)
586 (*uncompressed_sizes
)[i
] =
587 convert_to_section_size_type(uncompressed_size
);
591 return uncompressed_sizes
;
594 // Read the sections and symbols from an object file.
596 template<int size
, bool big_endian
>
598 Sized_relobj_file
<size
, big_endian
>::do_read_symbols(Read_symbols_data
* sd
)
600 this->read_section_data(&this->elf_file_
, sd
);
602 const unsigned char* const pshdrs
= sd
->section_headers
->data();
604 this->find_symtab(pshdrs
);
606 const unsigned char* namesu
= sd
->section_names
->data();
607 const char* names
= reinterpret_cast<const char*>(namesu
);
608 if (memmem(names
, sd
->section_names_size
, ".eh_frame", 10) != NULL
)
610 if (this->find_eh_frame(pshdrs
, names
, sd
->section_names_size
))
611 this->has_eh_frame_
= true;
613 if (memmem(names
, sd
->section_names_size
, ".zdebug_", 8) != NULL
)
614 this->compressed_sections_
=
615 build_compressed_section_map(pshdrs
, this->shnum(), names
,
616 sd
->section_names_size
, this);
619 sd
->symbols_size
= 0;
620 sd
->external_symbols_offset
= 0;
621 sd
->symbol_names
= NULL
;
622 sd
->symbol_names_size
= 0;
624 if (this->symtab_shndx_
== 0)
626 // No symbol table. Weird but legal.
630 // Get the symbol table section header.
631 typename
This::Shdr
symtabshdr(pshdrs
632 + this->symtab_shndx_
* This::shdr_size
);
633 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
635 // If this object has a .eh_frame section, we need all the symbols.
636 // Otherwise we only need the external symbols. While it would be
637 // simpler to just always read all the symbols, I've seen object
638 // files with well over 2000 local symbols, which for a 64-bit
639 // object file format is over 5 pages that we don't need to read
642 const int sym_size
= This::sym_size
;
643 const unsigned int loccount
= symtabshdr
.get_sh_info();
644 this->local_symbol_count_
= loccount
;
645 this->local_values_
.resize(loccount
);
646 section_offset_type locsize
= loccount
* sym_size
;
647 off_t dataoff
= symtabshdr
.get_sh_offset();
648 section_size_type datasize
=
649 convert_to_section_size_type(symtabshdr
.get_sh_size());
650 off_t extoff
= dataoff
+ locsize
;
651 section_size_type extsize
= datasize
- locsize
;
653 off_t readoff
= this->has_eh_frame_
? dataoff
: extoff
;
654 section_size_type readsize
= this->has_eh_frame_
? datasize
: extsize
;
658 // No external symbols. Also weird but also legal.
662 File_view
* fvsymtab
= this->get_lasting_view(readoff
, readsize
, true, false);
664 // Read the section header for the symbol names.
665 unsigned int strtab_shndx
= this->adjust_shndx(symtabshdr
.get_sh_link());
666 if (strtab_shndx
>= this->shnum())
668 this->error(_("invalid symbol table name index: %u"), strtab_shndx
);
671 typename
This::Shdr
strtabshdr(pshdrs
+ strtab_shndx
* This::shdr_size
);
672 if (strtabshdr
.get_sh_type() != elfcpp::SHT_STRTAB
)
674 this->error(_("symbol table name section has wrong type: %u"),
675 static_cast<unsigned int>(strtabshdr
.get_sh_type()));
679 // Read the symbol names.
680 File_view
* fvstrtab
= this->get_lasting_view(strtabshdr
.get_sh_offset(),
681 strtabshdr
.get_sh_size(),
684 sd
->symbols
= fvsymtab
;
685 sd
->symbols_size
= readsize
;
686 sd
->external_symbols_offset
= this->has_eh_frame_
? locsize
: 0;
687 sd
->symbol_names
= fvstrtab
;
688 sd
->symbol_names_size
=
689 convert_to_section_size_type(strtabshdr
.get_sh_size());
692 // Return the section index of symbol SYM. Set *VALUE to its value in
693 // the object file. Set *IS_ORDINARY if this is an ordinary section
694 // index, not a special code between SHN_LORESERVE and SHN_HIRESERVE.
695 // Note that for a symbol which is not defined in this object file,
696 // this will set *VALUE to 0 and return SHN_UNDEF; it will not return
697 // the final value of the symbol in the link.
699 template<int size
, bool big_endian
>
701 Sized_relobj_file
<size
, big_endian
>::symbol_section_and_value(unsigned int sym
,
705 section_size_type symbols_size
;
706 const unsigned char* symbols
= this->section_contents(this->symtab_shndx_
,
710 const size_t count
= symbols_size
/ This::sym_size
;
711 gold_assert(sym
< count
);
713 elfcpp::Sym
<size
, big_endian
> elfsym(symbols
+ sym
* This::sym_size
);
714 *value
= elfsym
.get_st_value();
716 return this->adjust_sym_shndx(sym
, elfsym
.get_st_shndx(), is_ordinary
);
719 // Return whether to include a section group in the link. LAYOUT is
720 // used to keep track of which section groups we have already seen.
721 // INDEX is the index of the section group and SHDR is the section
722 // header. If we do not want to include this group, we set bits in
723 // OMIT for each section which should be discarded.
725 template<int size
, bool big_endian
>
727 Sized_relobj_file
<size
, big_endian
>::include_section_group(
728 Symbol_table
* symtab
,
732 const unsigned char* shdrs
,
733 const char* section_names
,
734 section_size_type section_names_size
,
735 std::vector
<bool>* omit
)
737 // Read the section contents.
738 typename
This::Shdr
shdr(shdrs
+ index
* This::shdr_size
);
739 const unsigned char* pcon
= this->get_view(shdr
.get_sh_offset(),
740 shdr
.get_sh_size(), true, false);
741 const elfcpp::Elf_Word
* pword
=
742 reinterpret_cast<const elfcpp::Elf_Word
*>(pcon
);
744 // The first word contains flags. We only care about COMDAT section
745 // groups. Other section groups are always included in the link
746 // just like ordinary sections.
747 elfcpp::Elf_Word flags
= elfcpp::Swap
<32, big_endian
>::readval(pword
);
749 // Look up the group signature, which is the name of a symbol. This
750 // is a lot of effort to go to to read a string. Why didn't they
751 // just have the group signature point into the string table, rather
752 // than indirect through a symbol?
754 // Get the appropriate symbol table header (this will normally be
755 // the single SHT_SYMTAB section, but in principle it need not be).
756 const unsigned int link
= this->adjust_shndx(shdr
.get_sh_link());
757 typename
This::Shdr
symshdr(this, this->elf_file_
.section_header(link
));
759 // Read the symbol table entry.
760 unsigned int symndx
= shdr
.get_sh_info();
761 if (symndx
>= symshdr
.get_sh_size() / This::sym_size
)
763 this->error(_("section group %u info %u out of range"),
767 off_t symoff
= symshdr
.get_sh_offset() + symndx
* This::sym_size
;
768 const unsigned char* psym
= this->get_view(symoff
, This::sym_size
, true,
770 elfcpp::Sym
<size
, big_endian
> sym(psym
);
772 // Read the symbol table names.
773 section_size_type symnamelen
;
774 const unsigned char* psymnamesu
;
775 psymnamesu
= this->section_contents(this->adjust_shndx(symshdr
.get_sh_link()),
777 const char* psymnames
= reinterpret_cast<const char*>(psymnamesu
);
779 // Get the section group signature.
780 if (sym
.get_st_name() >= symnamelen
)
782 this->error(_("symbol %u name offset %u out of range"),
783 symndx
, sym
.get_st_name());
787 std::string
signature(psymnames
+ sym
.get_st_name());
789 // It seems that some versions of gas will create a section group
790 // associated with a section symbol, and then fail to give a name to
791 // the section symbol. In such a case, use the name of the section.
792 if (signature
[0] == '\0' && sym
.get_st_type() == elfcpp::STT_SECTION
)
795 unsigned int sym_shndx
= this->adjust_sym_shndx(symndx
,
798 if (!is_ordinary
|| sym_shndx
>= this->shnum())
800 this->error(_("symbol %u invalid section index %u"),
804 typename
This::Shdr
member_shdr(shdrs
+ sym_shndx
* This::shdr_size
);
805 if (member_shdr
.get_sh_name() < section_names_size
)
806 signature
= section_names
+ member_shdr
.get_sh_name();
809 // Record this section group in the layout, and see whether we've already
810 // seen one with the same signature.
813 Kept_section
* kept_section
= NULL
;
815 if ((flags
& elfcpp::GRP_COMDAT
) == 0)
817 include_group
= true;
822 include_group
= layout
->find_or_add_kept_section(signature
,
824 true, &kept_section
);
828 if (is_comdat
&& include_group
)
830 Incremental_inputs
* incremental_inputs
= layout
->incremental_inputs();
831 if (incremental_inputs
!= NULL
)
832 incremental_inputs
->report_comdat_group(this, signature
.c_str());
835 size_t count
= shdr
.get_sh_size() / sizeof(elfcpp::Elf_Word
);
837 std::vector
<unsigned int> shndxes
;
838 bool relocate_group
= include_group
&& parameters
->options().relocatable();
840 shndxes
.reserve(count
- 1);
842 for (size_t i
= 1; i
< count
; ++i
)
844 elfcpp::Elf_Word shndx
=
845 this->adjust_shndx(elfcpp::Swap
<32, big_endian
>::readval(pword
+ i
));
848 shndxes
.push_back(shndx
);
850 if (shndx
>= this->shnum())
852 this->error(_("section %u in section group %u out of range"),
857 // Check for an earlier section number, since we're going to get
858 // it wrong--we may have already decided to include the section.
860 this->error(_("invalid section group %u refers to earlier section %u"),
863 // Get the name of the member section.
864 typename
This::Shdr
member_shdr(shdrs
+ shndx
* This::shdr_size
);
865 if (member_shdr
.get_sh_name() >= section_names_size
)
867 // This is an error, but it will be diagnosed eventually
868 // in do_layout, so we don't need to do anything here but
872 std::string
mname(section_names
+ member_shdr
.get_sh_name());
877 kept_section
->add_comdat_section(mname
, shndx
,
878 member_shdr
.get_sh_size());
882 (*omit
)[shndx
] = true;
886 Relobj
* kept_object
= kept_section
->object();
887 if (kept_section
->is_comdat())
889 // Find the corresponding kept section, and store
890 // that info in the discarded section table.
891 unsigned int kept_shndx
;
893 if (kept_section
->find_comdat_section(mname
, &kept_shndx
,
896 // We don't keep a mapping for this section if
897 // it has a different size. The mapping is only
898 // used for relocation processing, and we don't
899 // want to treat the sections as similar if the
900 // sizes are different. Checking the section
901 // size is the approach used by the GNU linker.
902 if (kept_size
== member_shdr
.get_sh_size())
903 this->set_kept_comdat_section(shndx
, kept_object
,
909 // The existing section is a linkonce section. Add
910 // a mapping if there is exactly one section in the
911 // group (which is true when COUNT == 2) and if it
914 && (kept_section
->linkonce_size()
915 == member_shdr
.get_sh_size()))
916 this->set_kept_comdat_section(shndx
, kept_object
,
917 kept_section
->shndx());
924 layout
->layout_group(symtab
, this, index
, name
, signature
.c_str(),
925 shdr
, flags
, &shndxes
);
927 return include_group
;
930 // Whether to include a linkonce section in the link. NAME is the
931 // name of the section and SHDR is the section header.
933 // Linkonce sections are a GNU extension implemented in the original
934 // GNU linker before section groups were defined. The semantics are
935 // that we only include one linkonce section with a given name. The
936 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
937 // where T is the type of section and SYMNAME is the name of a symbol.
938 // In an attempt to make linkonce sections interact well with section
939 // groups, we try to identify SYMNAME and use it like a section group
940 // signature. We want to block section groups with that signature,
941 // but not other linkonce sections with that signature. We also use
942 // the full name of the linkonce section as a normal section group
945 template<int size
, bool big_endian
>
947 Sized_relobj_file
<size
, big_endian
>::include_linkonce_section(
951 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
953 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
954 // In general the symbol name we want will be the string following
955 // the last '.'. However, we have to handle the case of
956 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
957 // some versions of gcc. So we use a heuristic: if the name starts
958 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
959 // we look for the last '.'. We can't always simply skip
960 // ".gnu.linkonce.X", because we have to deal with cases like
961 // ".gnu.linkonce.d.rel.ro.local".
962 const char* const linkonce_t
= ".gnu.linkonce.t.";
964 if (strncmp(name
, linkonce_t
, strlen(linkonce_t
)) == 0)
965 symname
= name
+ strlen(linkonce_t
);
967 symname
= strrchr(name
, '.') + 1;
968 std::string
sig1(symname
);
969 std::string
sig2(name
);
972 bool include1
= layout
->find_or_add_kept_section(sig1
, this, index
, false,
974 bool include2
= layout
->find_or_add_kept_section(sig2
, this, index
, false,
979 // We are not including this section because we already saw the
980 // name of the section as a signature. This normally implies
981 // that the kept section is another linkonce section. If it is
982 // the same size, record it as the section which corresponds to
984 if (kept2
->object() != NULL
985 && !kept2
->is_comdat()
986 && kept2
->linkonce_size() == sh_size
)
987 this->set_kept_comdat_section(index
, kept2
->object(), kept2
->shndx());
991 // The section is being discarded on the basis of its symbol
992 // name. This means that the corresponding kept section was
993 // part of a comdat group, and it will be difficult to identify
994 // the specific section within that group that corresponds to
995 // this linkonce section. We'll handle the simple case where
996 // the group has only one member section. Otherwise, it's not
998 unsigned int kept_shndx
;
1000 if (kept1
->object() != NULL
1001 && kept1
->is_comdat()
1002 && kept1
->find_single_comdat_section(&kept_shndx
, &kept_size
)
1003 && kept_size
== sh_size
)
1004 this->set_kept_comdat_section(index
, kept1
->object(), kept_shndx
);
1008 kept1
->set_linkonce_size(sh_size
);
1009 kept2
->set_linkonce_size(sh_size
);
1012 return include1
&& include2
;
1015 // Layout an input section.
1017 template<int size
, bool big_endian
>
1019 Sized_relobj_file
<size
, big_endian
>::layout_section(Layout
* layout
,
1022 typename
This::Shdr
& shdr
,
1023 unsigned int reloc_shndx
,
1024 unsigned int reloc_type
)
1027 Output_section
* os
= layout
->layout(this, shndx
, name
, shdr
,
1028 reloc_shndx
, reloc_type
, &offset
);
1030 this->output_sections()[shndx
] = os
;
1032 this->section_offsets()[shndx
] = invalid_address
;
1034 this->section_offsets()[shndx
] = convert_types
<Address
, off_t
>(offset
);
1036 // If this section requires special handling, and if there are
1037 // relocs that apply to it, then we must do the special handling
1038 // before we apply the relocs.
1039 if (offset
== -1 && reloc_shndx
!= 0)
1040 this->set_relocs_must_follow_section_writes();
1043 // Lay out the input sections. We walk through the sections and check
1044 // whether they should be included in the link. If they should, we
1045 // pass them to the Layout object, which will return an output section
1047 // During garbage collection (--gc-sections) and identical code folding
1048 // (--icf), this function is called twice. When it is called the first
1049 // time, it is for setting up some sections as roots to a work-list for
1050 // --gc-sections and to do comdat processing. Actual layout happens the
1051 // second time around after all the relevant sections have been determined.
1052 // The first time, is_worklist_ready or is_icf_ready is false. It is then
1053 // set to true after the garbage collection worklist or identical code
1054 // folding is processed and the relevant sections to be kept are
1055 // determined. Then, this function is called again to layout the sections.
1057 template<int size
, bool big_endian
>
1059 Sized_relobj_file
<size
, big_endian
>::do_layout(Symbol_table
* symtab
,
1061 Read_symbols_data
* sd
)
1063 const unsigned int shnum
= this->shnum();
1064 bool is_gc_pass_one
= ((parameters
->options().gc_sections()
1065 && !symtab
->gc()->is_worklist_ready())
1066 || (parameters
->options().icf_enabled()
1067 && !symtab
->icf()->is_icf_ready()));
1069 bool is_gc_pass_two
= ((parameters
->options().gc_sections()
1070 && symtab
->gc()->is_worklist_ready())
1071 || (parameters
->options().icf_enabled()
1072 && symtab
->icf()->is_icf_ready()));
1074 bool is_gc_or_icf
= (parameters
->options().gc_sections()
1075 || parameters
->options().icf_enabled());
1077 // Both is_gc_pass_one and is_gc_pass_two should not be true.
1078 gold_assert(!(is_gc_pass_one
&& is_gc_pass_two
));
1082 Symbols_data
* gc_sd
= NULL
;
1085 // During garbage collection save the symbols data to use it when
1086 // re-entering this function.
1087 gc_sd
= new Symbols_data
;
1088 this->copy_symbols_data(gc_sd
, sd
, This::shdr_size
* shnum
);
1089 this->set_symbols_data(gc_sd
);
1091 else if (is_gc_pass_two
)
1093 gc_sd
= this->get_symbols_data();
1096 const unsigned char* section_headers_data
= NULL
;
1097 section_size_type section_names_size
;
1098 const unsigned char* symbols_data
= NULL
;
1099 section_size_type symbols_size
;
1100 section_offset_type external_symbols_offset
;
1101 const unsigned char* symbol_names_data
= NULL
;
1102 section_size_type symbol_names_size
;
1106 section_headers_data
= gc_sd
->section_headers_data
;
1107 section_names_size
= gc_sd
->section_names_size
;
1108 symbols_data
= gc_sd
->symbols_data
;
1109 symbols_size
= gc_sd
->symbols_size
;
1110 external_symbols_offset
= gc_sd
->external_symbols_offset
;
1111 symbol_names_data
= gc_sd
->symbol_names_data
;
1112 symbol_names_size
= gc_sd
->symbol_names_size
;
1116 section_headers_data
= sd
->section_headers
->data();
1117 section_names_size
= sd
->section_names_size
;
1118 if (sd
->symbols
!= NULL
)
1119 symbols_data
= sd
->symbols
->data();
1120 symbols_size
= sd
->symbols_size
;
1121 external_symbols_offset
= sd
->external_symbols_offset
;
1122 if (sd
->symbol_names
!= NULL
)
1123 symbol_names_data
= sd
->symbol_names
->data();
1124 symbol_names_size
= sd
->symbol_names_size
;
1127 // Get the section headers.
1128 const unsigned char* shdrs
= section_headers_data
;
1129 const unsigned char* pshdrs
;
1131 // Get the section names.
1132 const unsigned char* pnamesu
= (is_gc_or_icf
)
1133 ? gc_sd
->section_names_data
1134 : sd
->section_names
->data();
1136 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
1138 // If any input files have been claimed by plugins, we need to defer
1139 // actual layout until the replacement files have arrived.
1140 const bool should_defer_layout
=
1141 (parameters
->options().has_plugins()
1142 && parameters
->options().plugins()->should_defer_layout());
1143 unsigned int num_sections_to_defer
= 0;
1145 // For each section, record the index of the reloc section if any.
1146 // Use 0 to mean that there is no reloc section, -1U to mean that
1147 // there is more than one.
1148 std::vector
<unsigned int> reloc_shndx(shnum
, 0);
1149 std::vector
<unsigned int> reloc_type(shnum
, elfcpp::SHT_NULL
);
1150 // Skip the first, dummy, section.
1151 pshdrs
= shdrs
+ This::shdr_size
;
1152 for (unsigned int i
= 1; i
< shnum
; ++i
, pshdrs
+= This::shdr_size
)
1154 typename
This::Shdr
shdr(pshdrs
);
1156 // Count the number of sections whose layout will be deferred.
1157 if (should_defer_layout
&& (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
))
1158 ++num_sections_to_defer
;
1160 unsigned int sh_type
= shdr
.get_sh_type();
1161 if (sh_type
== elfcpp::SHT_REL
|| sh_type
== elfcpp::SHT_RELA
)
1163 unsigned int target_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1164 if (target_shndx
== 0 || target_shndx
>= shnum
)
1166 this->error(_("relocation section %u has bad info %u"),
1171 if (reloc_shndx
[target_shndx
] != 0)
1172 reloc_shndx
[target_shndx
] = -1U;
1175 reloc_shndx
[target_shndx
] = i
;
1176 reloc_type
[target_shndx
] = sh_type
;
1181 Output_sections
& out_sections(this->output_sections());
1182 std::vector
<Address
>& out_section_offsets(this->section_offsets());
1184 if (!is_gc_pass_two
)
1186 out_sections
.resize(shnum
);
1187 out_section_offsets
.resize(shnum
);
1190 // If we are only linking for symbols, then there is nothing else to
1192 if (this->input_file()->just_symbols())
1194 if (!is_gc_pass_two
)
1196 delete sd
->section_headers
;
1197 sd
->section_headers
= NULL
;
1198 delete sd
->section_names
;
1199 sd
->section_names
= NULL
;
1204 if (num_sections_to_defer
> 0)
1206 parameters
->options().plugins()->add_deferred_layout_object(this);
1207 this->deferred_layout_
.reserve(num_sections_to_defer
);
1210 // Whether we've seen a .note.GNU-stack section.
1211 bool seen_gnu_stack
= false;
1212 // The flags of a .note.GNU-stack section.
1213 uint64_t gnu_stack_flags
= 0;
1215 // Keep track of which sections to omit.
1216 std::vector
<bool> omit(shnum
, false);
1218 // Keep track of reloc sections when emitting relocations.
1219 const bool relocatable
= parameters
->options().relocatable();
1220 const bool emit_relocs
= (relocatable
1221 || parameters
->options().emit_relocs());
1222 std::vector
<unsigned int> reloc_sections
;
1224 // Keep track of .eh_frame sections.
1225 std::vector
<unsigned int> eh_frame_sections
;
1227 // Skip the first, dummy, section.
1228 pshdrs
= shdrs
+ This::shdr_size
;
1229 for (unsigned int i
= 1; i
< shnum
; ++i
, pshdrs
+= This::shdr_size
)
1231 typename
This::Shdr
shdr(pshdrs
);
1233 if (shdr
.get_sh_name() >= section_names_size
)
1235 this->error(_("bad section name offset for section %u: %lu"),
1236 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
1240 const char* name
= pnames
+ shdr
.get_sh_name();
1242 if (!is_gc_pass_two
)
1244 if (this->handle_gnu_warning_section(name
, i
, symtab
))
1250 // The .note.GNU-stack section is special. It gives the
1251 // protection flags that this object file requires for the stack
1253 if (strcmp(name
, ".note.GNU-stack") == 0)
1255 seen_gnu_stack
= true;
1256 gnu_stack_flags
|= shdr
.get_sh_flags();
1260 // The .note.GNU-split-stack section is also special. It
1261 // indicates that the object was compiled with
1263 if (this->handle_split_stack_section(name
))
1265 if (!parameters
->options().relocatable()
1266 && !parameters
->options().shared())
1270 // Skip attributes section.
1271 if (parameters
->target().is_attributes_section(name
))
1276 bool discard
= omit
[i
];
1279 if (shdr
.get_sh_type() == elfcpp::SHT_GROUP
)
1281 if (!this->include_section_group(symtab
, layout
, i
, name
,
1287 else if ((shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) == 0
1288 && Layout::is_linkonce(name
))
1290 if (!this->include_linkonce_section(layout
, i
, name
, shdr
))
1295 // Add the section to the incremental inputs layout.
1296 Incremental_inputs
* incremental_inputs
= layout
->incremental_inputs();
1297 if (incremental_inputs
!= NULL
1299 && (shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1300 || shdr
.get_sh_type() == elfcpp::SHT_NOBITS
1301 || shdr
.get_sh_type() == elfcpp::SHT_NOTE
))
1302 incremental_inputs
->report_input_section(this, i
, name
,
1303 shdr
.get_sh_size());
1307 // Do not include this section in the link.
1308 out_sections
[i
] = NULL
;
1309 out_section_offsets
[i
] = invalid_address
;
1314 if (is_gc_pass_one
&& parameters
->options().gc_sections())
1316 if (this->is_section_name_included(name
)
1317 || shdr
.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1318 || shdr
.get_sh_type() == elfcpp::SHT_FINI_ARRAY
)
1320 symtab
->gc()->worklist().push(Section_id(this, i
));
1322 // If the section name XXX can be represented as a C identifier
1323 // it cannot be discarded if there are references to
1324 // __start_XXX and __stop_XXX symbols. These need to be
1325 // specially handled.
1326 if (is_cident(name
))
1328 symtab
->gc()->add_cident_section(name
, Section_id(this, i
));
1332 // When doing a relocatable link we are going to copy input
1333 // reloc sections into the output. We only want to copy the
1334 // ones associated with sections which are not being discarded.
1335 // However, we don't know that yet for all sections. So save
1336 // reloc sections and process them later. Garbage collection is
1337 // not triggered when relocatable code is desired.
1339 && (shdr
.get_sh_type() == elfcpp::SHT_REL
1340 || shdr
.get_sh_type() == elfcpp::SHT_RELA
))
1342 reloc_sections
.push_back(i
);
1346 if (relocatable
&& shdr
.get_sh_type() == elfcpp::SHT_GROUP
)
1349 // The .eh_frame section is special. It holds exception frame
1350 // information that we need to read in order to generate the
1351 // exception frame header. We process these after all the other
1352 // sections so that the exception frame reader can reliably
1353 // determine which sections are being discarded, and discard the
1354 // corresponding information.
1356 && strcmp(name
, ".eh_frame") == 0
1357 && this->check_eh_frame_flags(&shdr
))
1361 out_sections
[i
] = reinterpret_cast<Output_section
*>(1);
1362 out_section_offsets
[i
] = invalid_address
;
1365 eh_frame_sections
.push_back(i
);
1369 if (is_gc_pass_two
&& parameters
->options().gc_sections())
1371 // This is executed during the second pass of garbage
1372 // collection. do_layout has been called before and some
1373 // sections have been already discarded. Simply ignore
1374 // such sections this time around.
1375 if (out_sections
[i
] == NULL
)
1377 gold_assert(out_section_offsets
[i
] == invalid_address
);
1380 if (((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0)
1381 && symtab
->gc()->is_section_garbage(this, i
))
1383 if (parameters
->options().print_gc_sections())
1384 gold_info(_("%s: removing unused section from '%s'"
1386 program_name
, this->section_name(i
).c_str(),
1387 this->name().c_str());
1388 out_sections
[i
] = NULL
;
1389 out_section_offsets
[i
] = invalid_address
;
1394 if (is_gc_pass_two
&& parameters
->options().icf_enabled())
1396 if (out_sections
[i
] == NULL
)
1398 gold_assert(out_section_offsets
[i
] == invalid_address
);
1401 if (((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0)
1402 && symtab
->icf()->is_section_folded(this, i
))
1404 if (parameters
->options().print_icf_sections())
1407 symtab
->icf()->get_folded_section(this, i
);
1408 Relobj
* folded_obj
=
1409 reinterpret_cast<Relobj
*>(folded
.first
);
1410 gold_info(_("%s: ICF folding section '%s' in file '%s'"
1411 "into '%s' in file '%s'"),
1412 program_name
, this->section_name(i
).c_str(),
1413 this->name().c_str(),
1414 folded_obj
->section_name(folded
.second
).c_str(),
1415 folded_obj
->name().c_str());
1417 out_sections
[i
] = NULL
;
1418 out_section_offsets
[i
] = invalid_address
;
1423 // Defer layout here if input files are claimed by plugins. When gc
1424 // is turned on this function is called twice. For the second call
1425 // should_defer_layout should be false.
1426 if (should_defer_layout
&& (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
))
1428 gold_assert(!is_gc_pass_two
);
1429 this->deferred_layout_
.push_back(Deferred_layout(i
, name
,
1433 // Put dummy values here; real values will be supplied by
1434 // do_layout_deferred_sections.
1435 out_sections
[i
] = reinterpret_cast<Output_section
*>(2);
1436 out_section_offsets
[i
] = invalid_address
;
1440 // During gc_pass_two if a section that was previously deferred is
1441 // found, do not layout the section as layout_deferred_sections will
1442 // do it later from gold.cc.
1444 && (out_sections
[i
] == reinterpret_cast<Output_section
*>(2)))
1449 // This is during garbage collection. The out_sections are
1450 // assigned in the second call to this function.
1451 out_sections
[i
] = reinterpret_cast<Output_section
*>(1);
1452 out_section_offsets
[i
] = invalid_address
;
1456 // When garbage collection is switched on the actual layout
1457 // only happens in the second call.
1458 this->layout_section(layout
, i
, name
, shdr
, reloc_shndx
[i
],
1463 if (!is_gc_pass_two
)
1464 layout
->layout_gnu_stack(seen_gnu_stack
, gnu_stack_flags
, this);
1466 // When doing a relocatable link handle the reloc sections at the
1467 // end. Garbage collection and Identical Code Folding is not
1468 // turned on for relocatable code.
1470 this->size_relocatable_relocs();
1472 gold_assert(!(is_gc_or_icf
) || reloc_sections
.empty());
1474 for (std::vector
<unsigned int>::const_iterator p
= reloc_sections
.begin();
1475 p
!= reloc_sections
.end();
1478 unsigned int i
= *p
;
1479 const unsigned char* pshdr
;
1480 pshdr
= section_headers_data
+ i
* This::shdr_size
;
1481 typename
This::Shdr
shdr(pshdr
);
1483 unsigned int data_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1484 if (data_shndx
>= shnum
)
1486 // We already warned about this above.
1490 Output_section
* data_section
= out_sections
[data_shndx
];
1491 if (data_section
== reinterpret_cast<Output_section
*>(2))
1493 // The layout for the data section was deferred, so we need
1494 // to defer the relocation section, too.
1495 const char* name
= pnames
+ shdr
.get_sh_name();
1496 this->deferred_layout_relocs_
.push_back(
1497 Deferred_layout(i
, name
, pshdr
, 0, elfcpp::SHT_NULL
));
1498 out_sections
[i
] = reinterpret_cast<Output_section
*>(2);
1499 out_section_offsets
[i
] = invalid_address
;
1502 if (data_section
== NULL
)
1504 out_sections
[i
] = NULL
;
1505 out_section_offsets
[i
] = invalid_address
;
1509 Relocatable_relocs
* rr
= new Relocatable_relocs();
1510 this->set_relocatable_relocs(i
, rr
);
1512 Output_section
* os
= layout
->layout_reloc(this, i
, shdr
, data_section
,
1514 out_sections
[i
] = os
;
1515 out_section_offsets
[i
] = invalid_address
;
1518 // Handle the .eh_frame sections at the end.
1519 gold_assert(!is_gc_pass_one
|| eh_frame_sections
.empty());
1520 for (std::vector
<unsigned int>::const_iterator p
= eh_frame_sections
.begin();
1521 p
!= eh_frame_sections
.end();
1524 gold_assert(this->has_eh_frame_
);
1525 gold_assert(external_symbols_offset
!= 0);
1527 unsigned int i
= *p
;
1528 const unsigned char* pshdr
;
1529 pshdr
= section_headers_data
+ i
* This::shdr_size
;
1530 typename
This::Shdr
shdr(pshdr
);
1533 Output_section
* os
= layout
->layout_eh_frame(this,
1542 out_sections
[i
] = os
;
1543 if (os
== NULL
|| offset
== -1)
1545 // An object can contain at most one section holding exception
1546 // frame information.
1547 gold_assert(this->discarded_eh_frame_shndx_
== -1U);
1548 this->discarded_eh_frame_shndx_
= i
;
1549 out_section_offsets
[i
] = invalid_address
;
1552 out_section_offsets
[i
] = convert_types
<Address
, off_t
>(offset
);
1554 // If this section requires special handling, and if there are
1555 // relocs that apply to it, then we must do the special handling
1556 // before we apply the relocs.
1557 if (os
!= NULL
&& offset
== -1 && reloc_shndx
[i
] != 0)
1558 this->set_relocs_must_follow_section_writes();
1563 delete[] gc_sd
->section_headers_data
;
1564 delete[] gc_sd
->section_names_data
;
1565 delete[] gc_sd
->symbols_data
;
1566 delete[] gc_sd
->symbol_names_data
;
1567 this->set_symbols_data(NULL
);
1571 delete sd
->section_headers
;
1572 sd
->section_headers
= NULL
;
1573 delete sd
->section_names
;
1574 sd
->section_names
= NULL
;
1578 // Layout sections whose layout was deferred while waiting for
1579 // input files from a plugin.
1581 template<int size
, bool big_endian
>
1583 Sized_relobj_file
<size
, big_endian
>::do_layout_deferred_sections(Layout
* layout
)
1585 typename
std::vector
<Deferred_layout
>::iterator deferred
;
1587 for (deferred
= this->deferred_layout_
.begin();
1588 deferred
!= this->deferred_layout_
.end();
1591 typename
This::Shdr
shdr(deferred
->shdr_data_
);
1592 // If the section is not included, it is because the garbage collector
1593 // decided it is not needed. Avoid reverting that decision.
1594 if (!this->is_section_included(deferred
->shndx_
))
1597 this->layout_section(layout
, deferred
->shndx_
, deferred
->name_
.c_str(),
1598 shdr
, deferred
->reloc_shndx_
, deferred
->reloc_type_
);
1601 this->deferred_layout_
.clear();
1603 // Now handle the deferred relocation sections.
1605 Output_sections
& out_sections(this->output_sections());
1606 std::vector
<Address
>& out_section_offsets(this->section_offsets());
1608 for (deferred
= this->deferred_layout_relocs_
.begin();
1609 deferred
!= this->deferred_layout_relocs_
.end();
1612 unsigned int shndx
= deferred
->shndx_
;
1613 typename
This::Shdr
shdr(deferred
->shdr_data_
);
1614 unsigned int data_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1616 Output_section
* data_section
= out_sections
[data_shndx
];
1617 if (data_section
== NULL
)
1619 out_sections
[shndx
] = NULL
;
1620 out_section_offsets
[shndx
] = invalid_address
;
1624 Relocatable_relocs
* rr
= new Relocatable_relocs();
1625 this->set_relocatable_relocs(shndx
, rr
);
1627 Output_section
* os
= layout
->layout_reloc(this, shndx
, shdr
,
1629 out_sections
[shndx
] = os
;
1630 out_section_offsets
[shndx
] = invalid_address
;
1634 // Add the symbols to the symbol table.
1636 template<int size
, bool big_endian
>
1638 Sized_relobj_file
<size
, big_endian
>::do_add_symbols(Symbol_table
* symtab
,
1639 Read_symbols_data
* sd
,
1642 if (sd
->symbols
== NULL
)
1644 gold_assert(sd
->symbol_names
== NULL
);
1648 const int sym_size
= This::sym_size
;
1649 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1651 if (symcount
* sym_size
!= sd
->symbols_size
- sd
->external_symbols_offset
)
1653 this->error(_("size of symbols is not multiple of symbol size"));
1657 this->symbols_
.resize(symcount
);
1659 const char* sym_names
=
1660 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1661 symtab
->add_from_relobj(this,
1662 sd
->symbols
->data() + sd
->external_symbols_offset
,
1663 symcount
, this->local_symbol_count_
,
1664 sym_names
, sd
->symbol_names_size
,
1666 &this->defined_count_
);
1670 delete sd
->symbol_names
;
1671 sd
->symbol_names
= NULL
;
1674 // Find out if this object, that is a member of a lib group, should be included
1675 // in the link. We check every symbol defined by this object. If the symbol
1676 // table has a strong undefined reference to that symbol, we have to include
1679 template<int size
, bool big_endian
>
1680 Archive::Should_include
1681 Sized_relobj_file
<size
, big_endian
>::do_should_include_member(
1682 Symbol_table
* symtab
,
1684 Read_symbols_data
* sd
,
1687 char* tmpbuf
= NULL
;
1688 size_t tmpbuflen
= 0;
1689 const char* sym_names
=
1690 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1691 const unsigned char* syms
=
1692 sd
->symbols
->data() + sd
->external_symbols_offset
;
1693 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1694 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1697 const unsigned char* p
= syms
;
1699 for (size_t i
= 0; i
< symcount
; ++i
, p
+= sym_size
)
1701 elfcpp::Sym
<size
, big_endian
> sym(p
);
1702 unsigned int st_shndx
= sym
.get_st_shndx();
1703 if (st_shndx
== elfcpp::SHN_UNDEF
)
1706 unsigned int st_name
= sym
.get_st_name();
1707 const char* name
= sym_names
+ st_name
;
1709 Archive::Should_include t
= Archive::should_include_member(symtab
,
1715 if (t
== Archive::SHOULD_INCLUDE_YES
)
1724 return Archive::SHOULD_INCLUDE_UNKNOWN
;
1727 // Iterate over global defined symbols, calling a visitor class V for each.
1729 template<int size
, bool big_endian
>
1731 Sized_relobj_file
<size
, big_endian
>::do_for_all_global_symbols(
1732 Read_symbols_data
* sd
,
1733 Library_base::Symbol_visitor_base
* v
)
1735 const char* sym_names
=
1736 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1737 const unsigned char* syms
=
1738 sd
->symbols
->data() + sd
->external_symbols_offset
;
1739 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1740 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1742 const unsigned char* p
= syms
;
1744 for (size_t i
= 0; i
< symcount
; ++i
, p
+= sym_size
)
1746 elfcpp::Sym
<size
, big_endian
> sym(p
);
1747 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
1748 v
->visit(sym_names
+ sym
.get_st_name());
1752 // Return whether the local symbol SYMNDX has a PLT offset.
1754 template<int size
, bool big_endian
>
1756 Sized_relobj_file
<size
, big_endian
>::local_has_plt_offset(
1757 unsigned int symndx
) const
1759 typename
Local_plt_offsets::const_iterator p
=
1760 this->local_plt_offsets_
.find(symndx
);
1761 return p
!= this->local_plt_offsets_
.end();
1764 // Get the PLT offset of a local symbol.
1766 template<int size
, bool big_endian
>
1768 Sized_relobj_file
<size
, big_endian
>::local_plt_offset(unsigned int symndx
) const
1770 typename
Local_plt_offsets::const_iterator p
=
1771 this->local_plt_offsets_
.find(symndx
);
1772 gold_assert(p
!= this->local_plt_offsets_
.end());
1776 // Set the PLT offset of a local symbol.
1778 template<int size
, bool big_endian
>
1780 Sized_relobj_file
<size
, big_endian
>::set_local_plt_offset(
1781 unsigned int symndx
, unsigned int plt_offset
)
1783 std::pair
<typename
Local_plt_offsets::iterator
, bool> ins
=
1784 this->local_plt_offsets_
.insert(std::make_pair(symndx
, plt_offset
));
1785 gold_assert(ins
.second
);
1788 // First pass over the local symbols. Here we add their names to
1789 // *POOL and *DYNPOOL, and we store the symbol value in
1790 // THIS->LOCAL_VALUES_. This function is always called from a
1791 // singleton thread. This is followed by a call to
1792 // finalize_local_symbols.
1794 template<int size
, bool big_endian
>
1796 Sized_relobj_file
<size
, big_endian
>::do_count_local_symbols(Stringpool
* pool
,
1797 Stringpool
* dynpool
)
1799 gold_assert(this->symtab_shndx_
!= -1U);
1800 if (this->symtab_shndx_
== 0)
1802 // This object has no symbols. Weird but legal.
1806 // Read the symbol table section header.
1807 const unsigned int symtab_shndx
= this->symtab_shndx_
;
1808 typename
This::Shdr
symtabshdr(this,
1809 this->elf_file_
.section_header(symtab_shndx
));
1810 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
1812 // Read the local symbols.
1813 const int sym_size
= This::sym_size
;
1814 const unsigned int loccount
= this->local_symbol_count_
;
1815 gold_assert(loccount
== symtabshdr
.get_sh_info());
1816 off_t locsize
= loccount
* sym_size
;
1817 const unsigned char* psyms
= this->get_view(symtabshdr
.get_sh_offset(),
1818 locsize
, true, true);
1820 // Read the symbol names.
1821 const unsigned int strtab_shndx
=
1822 this->adjust_shndx(symtabshdr
.get_sh_link());
1823 section_size_type strtab_size
;
1824 const unsigned char* pnamesu
= this->section_contents(strtab_shndx
,
1827 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
1829 // Loop over the local symbols.
1831 const Output_sections
& out_sections(this->output_sections());
1832 unsigned int shnum
= this->shnum();
1833 unsigned int count
= 0;
1834 unsigned int dyncount
= 0;
1835 // Skip the first, dummy, symbol.
1837 bool strip_all
= parameters
->options().strip_all();
1838 bool discard_all
= parameters
->options().discard_all();
1839 bool discard_locals
= parameters
->options().discard_locals();
1840 for (unsigned int i
= 1; i
< loccount
; ++i
, psyms
+= sym_size
)
1842 elfcpp::Sym
<size
, big_endian
> sym(psyms
);
1844 Symbol_value
<size
>& lv(this->local_values_
[i
]);
1847 unsigned int shndx
= this->adjust_sym_shndx(i
, sym
.get_st_shndx(),
1849 lv
.set_input_shndx(shndx
, is_ordinary
);
1851 if (sym
.get_st_type() == elfcpp::STT_SECTION
)
1852 lv
.set_is_section_symbol();
1853 else if (sym
.get_st_type() == elfcpp::STT_TLS
)
1854 lv
.set_is_tls_symbol();
1855 else if (sym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1856 lv
.set_is_ifunc_symbol();
1858 // Save the input symbol value for use in do_finalize_local_symbols().
1859 lv
.set_input_value(sym
.get_st_value());
1861 // Decide whether this symbol should go into the output file.
1863 if ((shndx
< shnum
&& out_sections
[shndx
] == NULL
)
1864 || shndx
== this->discarded_eh_frame_shndx_
)
1866 lv
.set_no_output_symtab_entry();
1867 gold_assert(!lv
.needs_output_dynsym_entry());
1871 if (sym
.get_st_type() == elfcpp::STT_SECTION
)
1873 lv
.set_no_output_symtab_entry();
1874 gold_assert(!lv
.needs_output_dynsym_entry());
1878 if (sym
.get_st_name() >= strtab_size
)
1880 this->error(_("local symbol %u section name out of range: %u >= %u"),
1881 i
, sym
.get_st_name(),
1882 static_cast<unsigned int>(strtab_size
));
1883 lv
.set_no_output_symtab_entry();
1887 const char* name
= pnames
+ sym
.get_st_name();
1889 // If needed, add the symbol to the dynamic symbol table string pool.
1890 if (lv
.needs_output_dynsym_entry())
1892 dynpool
->add(name
, true, NULL
);
1897 || (discard_all
&& lv
.may_be_discarded_from_output_symtab()))
1899 lv
.set_no_output_symtab_entry();
1903 // If --discard-locals option is used, discard all temporary local
1904 // symbols. These symbols start with system-specific local label
1905 // prefixes, typically .L for ELF system. We want to be compatible
1906 // with GNU ld so here we essentially use the same check in
1907 // bfd_is_local_label(). The code is different because we already
1910 // - the symbol is local and thus cannot have global or weak binding.
1911 // - the symbol is not a section symbol.
1912 // - the symbol has a name.
1914 // We do not discard a symbol if it needs a dynamic symbol entry.
1916 && sym
.get_st_type() != elfcpp::STT_FILE
1917 && !lv
.needs_output_dynsym_entry()
1918 && lv
.may_be_discarded_from_output_symtab()
1919 && parameters
->target().is_local_label_name(name
))
1921 lv
.set_no_output_symtab_entry();
1925 // Discard the local symbol if -retain_symbols_file is specified
1926 // and the local symbol is not in that file.
1927 if (!parameters
->options().should_retain_symbol(name
))
1929 lv
.set_no_output_symtab_entry();
1933 // Add the symbol to the symbol table string pool.
1934 pool
->add(name
, true, NULL
);
1938 this->output_local_symbol_count_
= count
;
1939 this->output_local_dynsym_count_
= dyncount
;
1942 // Compute the final value of a local symbol.
1944 template<int size
, bool big_endian
>
1945 typename Sized_relobj_file
<size
, big_endian
>::Compute_final_local_value_status
1946 Sized_relobj_file
<size
, big_endian
>::compute_final_local_value_internal(
1948 const Symbol_value
<size
>* lv_in
,
1949 Symbol_value
<size
>* lv_out
,
1951 const Output_sections
& out_sections
,
1952 const std::vector
<Address
>& out_offsets
,
1953 const Symbol_table
* symtab
)
1955 // We are going to overwrite *LV_OUT, if it has a merged symbol value,
1956 // we may have a memory leak.
1957 gold_assert(lv_out
->has_output_value());
1960 unsigned int shndx
= lv_in
->input_shndx(&is_ordinary
);
1962 // Set the output symbol value.
1966 if (shndx
== elfcpp::SHN_ABS
|| Symbol::is_common_shndx(shndx
))
1967 lv_out
->set_output_value(lv_in
->input_value());
1970 this->error(_("unknown section index %u for local symbol %u"),
1972 lv_out
->set_output_value(0);
1973 return This::CFLV_ERROR
;
1978 if (shndx
>= this->shnum())
1980 this->error(_("local symbol %u section index %u out of range"),
1982 lv_out
->set_output_value(0);
1983 return This::CFLV_ERROR
;
1986 Output_section
* os
= out_sections
[shndx
];
1987 Address secoffset
= out_offsets
[shndx
];
1988 if (symtab
->is_section_folded(this, shndx
))
1990 gold_assert(os
== NULL
&& secoffset
== invalid_address
);
1991 // Get the os of the section it is folded onto.
1992 Section_id folded
= symtab
->icf()->get_folded_section(this,
1994 gold_assert(folded
.first
!= NULL
);
1995 Sized_relobj_file
<size
, big_endian
>* folded_obj
= reinterpret_cast
1996 <Sized_relobj_file
<size
, big_endian
>*>(folded
.first
);
1997 os
= folded_obj
->output_section(folded
.second
);
1998 gold_assert(os
!= NULL
);
1999 secoffset
= folded_obj
->get_output_section_offset(folded
.second
);
2001 // This could be a relaxed input section.
2002 if (secoffset
== invalid_address
)
2004 const Output_relaxed_input_section
* relaxed_section
=
2005 os
->find_relaxed_input_section(folded_obj
, folded
.second
);
2006 gold_assert(relaxed_section
!= NULL
);
2007 secoffset
= relaxed_section
->address() - os
->address();
2013 // This local symbol belongs to a section we are discarding.
2014 // In some cases when applying relocations later, we will
2015 // attempt to match it to the corresponding kept section,
2016 // so we leave the input value unchanged here.
2017 return This::CFLV_DISCARDED
;
2019 else if (secoffset
== invalid_address
)
2023 // This is a SHF_MERGE section or one which otherwise
2024 // requires special handling.
2025 if (shndx
== this->discarded_eh_frame_shndx_
)
2027 // This local symbol belongs to a discarded .eh_frame
2028 // section. Just treat it like the case in which
2029 // os == NULL above.
2030 gold_assert(this->has_eh_frame_
);
2031 return This::CFLV_DISCARDED
;
2033 else if (!lv_in
->is_section_symbol())
2035 // This is not a section symbol. We can determine
2036 // the final value now.
2037 lv_out
->set_output_value(
2038 os
->output_address(this, shndx
, lv_in
->input_value()));
2040 else if (!os
->find_starting_output_address(this, shndx
, &start
))
2042 // This is a section symbol, but apparently not one in a
2043 // merged section. First check to see if this is a relaxed
2044 // input section. If so, use its address. Otherwise just
2045 // use the start of the output section. This happens with
2046 // relocatable links when the input object has section
2047 // symbols for arbitrary non-merge sections.
2048 const Output_section_data
* posd
=
2049 os
->find_relaxed_input_section(this, shndx
);
2052 Address relocatable_link_adjustment
=
2053 relocatable
? os
->address() : 0;
2054 lv_out
->set_output_value(posd
->address()
2055 - relocatable_link_adjustment
);
2058 lv_out
->set_output_value(os
->address());
2062 // We have to consider the addend to determine the
2063 // value to use in a relocation. START is the start
2064 // of this input section. If we are doing a relocatable
2065 // link, use offset from start output section instead of
2067 Address adjusted_start
=
2068 relocatable
? start
- os
->address() : start
;
2069 Merged_symbol_value
<size
>* msv
=
2070 new Merged_symbol_value
<size
>(lv_in
->input_value(),
2072 lv_out
->set_merged_symbol_value(msv
);
2075 else if (lv_in
->is_tls_symbol())
2076 lv_out
->set_output_value(os
->tls_offset()
2078 + lv_in
->input_value());
2080 lv_out
->set_output_value((relocatable
? 0 : os
->address())
2082 + lv_in
->input_value());
2084 return This::CFLV_OK
;
2087 // Compute final local symbol value. R_SYM is the index of a local
2088 // symbol in symbol table. LV points to a symbol value, which is
2089 // expected to hold the input value and to be over-written by the
2090 // final value. SYMTAB points to a symbol table. Some targets may want
2091 // to know would-be-finalized local symbol values in relaxation.
2092 // Hence we provide this method. Since this method updates *LV, a
2093 // callee should make a copy of the original local symbol value and
2094 // use the copy instead of modifying an object's local symbols before
2095 // everything is finalized. The caller should also free up any allocated
2096 // memory in the return value in *LV.
2097 template<int size
, bool big_endian
>
2098 typename Sized_relobj_file
<size
, big_endian
>::Compute_final_local_value_status
2099 Sized_relobj_file
<size
, big_endian
>::compute_final_local_value(
2101 const Symbol_value
<size
>* lv_in
,
2102 Symbol_value
<size
>* lv_out
,
2103 const Symbol_table
* symtab
)
2105 // This is just a wrapper of compute_final_local_value_internal.
2106 const bool relocatable
= parameters
->options().relocatable();
2107 const Output_sections
& out_sections(this->output_sections());
2108 const std::vector
<Address
>& out_offsets(this->section_offsets());
2109 return this->compute_final_local_value_internal(r_sym
, lv_in
, lv_out
,
2110 relocatable
, out_sections
,
2111 out_offsets
, symtab
);
2114 // Finalize the local symbols. Here we set the final value in
2115 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
2116 // This function is always called from a singleton thread. The actual
2117 // output of the local symbols will occur in a separate task.
2119 template<int size
, bool big_endian
>
2121 Sized_relobj_file
<size
, big_endian
>::do_finalize_local_symbols(
2124 Symbol_table
* symtab
)
2126 gold_assert(off
== static_cast<off_t
>(align_address(off
, size
>> 3)));
2128 const unsigned int loccount
= this->local_symbol_count_
;
2129 this->local_symbol_offset_
= off
;
2131 const bool relocatable
= parameters
->options().relocatable();
2132 const Output_sections
& out_sections(this->output_sections());
2133 const std::vector
<Address
>& out_offsets(this->section_offsets());
2135 for (unsigned int i
= 1; i
< loccount
; ++i
)
2137 Symbol_value
<size
>* lv
= &this->local_values_
[i
];
2139 Compute_final_local_value_status cflv_status
=
2140 this->compute_final_local_value_internal(i
, lv
, lv
, relocatable
,
2141 out_sections
, out_offsets
,
2143 switch (cflv_status
)
2146 if (!lv
->is_output_symtab_index_set())
2148 lv
->set_output_symtab_index(index
);
2152 case CFLV_DISCARDED
:
2163 // Set the output dynamic symbol table indexes for the local variables.
2165 template<int size
, bool big_endian
>
2167 Sized_relobj_file
<size
, big_endian
>::do_set_local_dynsym_indexes(
2170 const unsigned int loccount
= this->local_symbol_count_
;
2171 for (unsigned int i
= 1; i
< loccount
; ++i
)
2173 Symbol_value
<size
>& lv(this->local_values_
[i
]);
2174 if (lv
.needs_output_dynsym_entry())
2176 lv
.set_output_dynsym_index(index
);
2183 // Set the offset where local dynamic symbol information will be stored.
2184 // Returns the count of local symbols contributed to the symbol table by
2187 template<int size
, bool big_endian
>
2189 Sized_relobj_file
<size
, big_endian
>::do_set_local_dynsym_offset(off_t off
)
2191 gold_assert(off
== static_cast<off_t
>(align_address(off
, size
>> 3)));
2192 this->local_dynsym_offset_
= off
;
2193 return this->output_local_dynsym_count_
;
2196 // If Symbols_data is not NULL get the section flags from here otherwise
2197 // get it from the file.
2199 template<int size
, bool big_endian
>
2201 Sized_relobj_file
<size
, big_endian
>::do_section_flags(unsigned int shndx
)
2203 Symbols_data
* sd
= this->get_symbols_data();
2206 const unsigned char* pshdrs
= sd
->section_headers_data
2207 + This::shdr_size
* shndx
;
2208 typename
This::Shdr
shdr(pshdrs
);
2209 return shdr
.get_sh_flags();
2211 // If sd is NULL, read the section header from the file.
2212 return this->elf_file_
.section_flags(shndx
);
2215 // Get the section's ent size from Symbols_data. Called by get_section_contents
2218 template<int size
, bool big_endian
>
2220 Sized_relobj_file
<size
, big_endian
>::do_section_entsize(unsigned int shndx
)
2222 Symbols_data
* sd
= this->get_symbols_data();
2223 gold_assert(sd
!= NULL
);
2225 const unsigned char* pshdrs
= sd
->section_headers_data
2226 + This::shdr_size
* shndx
;
2227 typename
This::Shdr
shdr(pshdrs
);
2228 return shdr
.get_sh_entsize();
2231 // Write out the local symbols.
2233 template<int size
, bool big_endian
>
2235 Sized_relobj_file
<size
, big_endian
>::write_local_symbols(
2237 const Stringpool
* sympool
,
2238 const Stringpool
* dynpool
,
2239 Output_symtab_xindex
* symtab_xindex
,
2240 Output_symtab_xindex
* dynsym_xindex
,
2243 const bool strip_all
= parameters
->options().strip_all();
2246 if (this->output_local_dynsym_count_
== 0)
2248 this->output_local_symbol_count_
= 0;
2251 gold_assert(this->symtab_shndx_
!= -1U);
2252 if (this->symtab_shndx_
== 0)
2254 // This object has no symbols. Weird but legal.
2258 // Read the symbol table section header.
2259 const unsigned int symtab_shndx
= this->symtab_shndx_
;
2260 typename
This::Shdr
symtabshdr(this,
2261 this->elf_file_
.section_header(symtab_shndx
));
2262 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
2263 const unsigned int loccount
= this->local_symbol_count_
;
2264 gold_assert(loccount
== symtabshdr
.get_sh_info());
2266 // Read the local symbols.
2267 const int sym_size
= This::sym_size
;
2268 off_t locsize
= loccount
* sym_size
;
2269 const unsigned char* psyms
= this->get_view(symtabshdr
.get_sh_offset(),
2270 locsize
, true, false);
2272 // Read the symbol names.
2273 const unsigned int strtab_shndx
=
2274 this->adjust_shndx(symtabshdr
.get_sh_link());
2275 section_size_type strtab_size
;
2276 const unsigned char* pnamesu
= this->section_contents(strtab_shndx
,
2279 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
2281 // Get views into the output file for the portions of the symbol table
2282 // and the dynamic symbol table that we will be writing.
2283 off_t output_size
= this->output_local_symbol_count_
* sym_size
;
2284 unsigned char* oview
= NULL
;
2285 if (output_size
> 0)
2286 oview
= of
->get_output_view(symtab_off
+ this->local_symbol_offset_
,
2289 off_t dyn_output_size
= this->output_local_dynsym_count_
* sym_size
;
2290 unsigned char* dyn_oview
= NULL
;
2291 if (dyn_output_size
> 0)
2292 dyn_oview
= of
->get_output_view(this->local_dynsym_offset_
,
2295 const Output_sections
out_sections(this->output_sections());
2297 gold_assert(this->local_values_
.size() == loccount
);
2299 unsigned char* ov
= oview
;
2300 unsigned char* dyn_ov
= dyn_oview
;
2302 for (unsigned int i
= 1; i
< loccount
; ++i
, psyms
+= sym_size
)
2304 elfcpp::Sym
<size
, big_endian
> isym(psyms
);
2306 Symbol_value
<size
>& lv(this->local_values_
[i
]);
2309 unsigned int st_shndx
= this->adjust_sym_shndx(i
, isym
.get_st_shndx(),
2313 gold_assert(st_shndx
< out_sections
.size());
2314 if (out_sections
[st_shndx
] == NULL
)
2316 st_shndx
= out_sections
[st_shndx
]->out_shndx();
2317 if (st_shndx
>= elfcpp::SHN_LORESERVE
)
2319 if (lv
.has_output_symtab_entry())
2320 symtab_xindex
->add(lv
.output_symtab_index(), st_shndx
);
2321 if (lv
.has_output_dynsym_entry())
2322 dynsym_xindex
->add(lv
.output_dynsym_index(), st_shndx
);
2323 st_shndx
= elfcpp::SHN_XINDEX
;
2327 // Write the symbol to the output symbol table.
2328 if (lv
.has_output_symtab_entry())
2330 elfcpp::Sym_write
<size
, big_endian
> osym(ov
);
2332 gold_assert(isym
.get_st_name() < strtab_size
);
2333 const char* name
= pnames
+ isym
.get_st_name();
2334 osym
.put_st_name(sympool
->get_offset(name
));
2335 osym
.put_st_value(this->local_values_
[i
].value(this, 0));
2336 osym
.put_st_size(isym
.get_st_size());
2337 osym
.put_st_info(isym
.get_st_info());
2338 osym
.put_st_other(isym
.get_st_other());
2339 osym
.put_st_shndx(st_shndx
);
2344 // Write the symbol to the output dynamic symbol table.
2345 if (lv
.has_output_dynsym_entry())
2347 gold_assert(dyn_ov
< dyn_oview
+ dyn_output_size
);
2348 elfcpp::Sym_write
<size
, big_endian
> osym(dyn_ov
);
2350 gold_assert(isym
.get_st_name() < strtab_size
);
2351 const char* name
= pnames
+ isym
.get_st_name();
2352 osym
.put_st_name(dynpool
->get_offset(name
));
2353 osym
.put_st_value(this->local_values_
[i
].value(this, 0));
2354 osym
.put_st_size(isym
.get_st_size());
2355 osym
.put_st_info(isym
.get_st_info());
2356 osym
.put_st_other(isym
.get_st_other());
2357 osym
.put_st_shndx(st_shndx
);
2364 if (output_size
> 0)
2366 gold_assert(ov
- oview
== output_size
);
2367 of
->write_output_view(symtab_off
+ this->local_symbol_offset_
,
2368 output_size
, oview
);
2371 if (dyn_output_size
> 0)
2373 gold_assert(dyn_ov
- dyn_oview
== dyn_output_size
);
2374 of
->write_output_view(this->local_dynsym_offset_
, dyn_output_size
,
2379 // Set *INFO to symbolic information about the offset OFFSET in the
2380 // section SHNDX. Return true if we found something, false if we
2383 template<int size
, bool big_endian
>
2385 Sized_relobj_file
<size
, big_endian
>::get_symbol_location_info(
2388 Symbol_location_info
* info
)
2390 if (this->symtab_shndx_
== 0)
2393 section_size_type symbols_size
;
2394 const unsigned char* symbols
= this->section_contents(this->symtab_shndx_
,
2398 unsigned int symbol_names_shndx
=
2399 this->adjust_shndx(this->section_link(this->symtab_shndx_
));
2400 section_size_type names_size
;
2401 const unsigned char* symbol_names_u
=
2402 this->section_contents(symbol_names_shndx
, &names_size
, false);
2403 const char* symbol_names
= reinterpret_cast<const char*>(symbol_names_u
);
2405 const int sym_size
= This::sym_size
;
2406 const size_t count
= symbols_size
/ sym_size
;
2408 const unsigned char* p
= symbols
;
2409 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
2411 elfcpp::Sym
<size
, big_endian
> sym(p
);
2413 if (sym
.get_st_type() == elfcpp::STT_FILE
)
2415 if (sym
.get_st_name() >= names_size
)
2416 info
->source_file
= "(invalid)";
2418 info
->source_file
= symbol_names
+ sym
.get_st_name();
2423 unsigned int st_shndx
= this->adjust_sym_shndx(i
, sym
.get_st_shndx(),
2426 && st_shndx
== shndx
2427 && static_cast<off_t
>(sym
.get_st_value()) <= offset
2428 && (static_cast<off_t
>(sym
.get_st_value() + sym
.get_st_size())
2431 if (sym
.get_st_name() > names_size
)
2432 info
->enclosing_symbol_name
= "(invalid)";
2435 info
->enclosing_symbol_name
= symbol_names
+ sym
.get_st_name();
2436 if (parameters
->options().do_demangle())
2438 char* demangled_name
= cplus_demangle(
2439 info
->enclosing_symbol_name
.c_str(),
2440 DMGL_ANSI
| DMGL_PARAMS
);
2441 if (demangled_name
!= NULL
)
2443 info
->enclosing_symbol_name
.assign(demangled_name
);
2444 free(demangled_name
);
2455 // Look for a kept section corresponding to the given discarded section,
2456 // and return its output address. This is used only for relocations in
2457 // debugging sections. If we can't find the kept section, return 0.
2459 template<int size
, bool big_endian
>
2460 typename Sized_relobj_file
<size
, big_endian
>::Address
2461 Sized_relobj_file
<size
, big_endian
>::map_to_kept_section(
2465 Relobj
* kept_object
;
2466 unsigned int kept_shndx
;
2467 if (this->get_kept_comdat_section(shndx
, &kept_object
, &kept_shndx
))
2469 Sized_relobj_file
<size
, big_endian
>* kept_relobj
=
2470 static_cast<Sized_relobj_file
<size
, big_endian
>*>(kept_object
);
2471 Output_section
* os
= kept_relobj
->output_section(kept_shndx
);
2472 Address offset
= kept_relobj
->get_output_section_offset(kept_shndx
);
2473 if (os
!= NULL
&& offset
!= invalid_address
)
2476 return os
->address() + offset
;
2483 // Get symbol counts.
2485 template<int size
, bool big_endian
>
2487 Sized_relobj_file
<size
, big_endian
>::do_get_global_symbol_counts(
2488 const Symbol_table
*,
2492 *defined
= this->defined_count_
;
2494 for (typename
Symbols::const_iterator p
= this->symbols_
.begin();
2495 p
!= this->symbols_
.end();
2498 && (*p
)->source() == Symbol::FROM_OBJECT
2499 && (*p
)->object() == this
2500 && (*p
)->is_defined())
2505 // Input_objects methods.
2507 // Add a regular relocatable object to the list. Return false if this
2508 // object should be ignored.
2511 Input_objects::add_object(Object
* obj
)
2513 // Print the filename if the -t/--trace option is selected.
2514 if (parameters
->options().trace())
2515 gold_info("%s", obj
->name().c_str());
2517 if (!obj
->is_dynamic())
2518 this->relobj_list_
.push_back(static_cast<Relobj
*>(obj
));
2521 // See if this is a duplicate SONAME.
2522 Dynobj
* dynobj
= static_cast<Dynobj
*>(obj
);
2523 const char* soname
= dynobj
->soname();
2525 std::pair
<Unordered_set
<std::string
>::iterator
, bool> ins
=
2526 this->sonames_
.insert(soname
);
2529 // We have already seen a dynamic object with this soname.
2533 this->dynobj_list_
.push_back(dynobj
);
2536 // Add this object to the cross-referencer if requested.
2537 if (parameters
->options().user_set_print_symbol_counts()
2538 || parameters
->options().cref())
2540 if (this->cref_
== NULL
)
2541 this->cref_
= new Cref();
2542 this->cref_
->add_object(obj
);
2548 // For each dynamic object, record whether we've seen all of its
2549 // explicit dependencies.
2552 Input_objects::check_dynamic_dependencies() const
2554 bool issued_copy_dt_needed_error
= false;
2555 for (Dynobj_list::const_iterator p
= this->dynobj_list_
.begin();
2556 p
!= this->dynobj_list_
.end();
2559 const Dynobj::Needed
& needed((*p
)->needed());
2560 bool found_all
= true;
2561 Dynobj::Needed::const_iterator pneeded
;
2562 for (pneeded
= needed
.begin(); pneeded
!= needed
.end(); ++pneeded
)
2564 if (this->sonames_
.find(*pneeded
) == this->sonames_
.end())
2570 (*p
)->set_has_unknown_needed_entries(!found_all
);
2572 // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2573 // that gold does not support. However, they cause no trouble
2574 // unless there is a DT_NEEDED entry that we don't know about;
2575 // warn only in that case.
2577 && !issued_copy_dt_needed_error
2578 && (parameters
->options().copy_dt_needed_entries()
2579 || parameters
->options().add_needed()))
2581 const char* optname
;
2582 if (parameters
->options().copy_dt_needed_entries())
2583 optname
= "--copy-dt-needed-entries";
2585 optname
= "--add-needed";
2586 gold_error(_("%s is not supported but is required for %s in %s"),
2587 optname
, (*pneeded
).c_str(), (*p
)->name().c_str());
2588 issued_copy_dt_needed_error
= true;
2593 // Start processing an archive.
2596 Input_objects::archive_start(Archive
* archive
)
2598 if (parameters
->options().user_set_print_symbol_counts()
2599 || parameters
->options().cref())
2601 if (this->cref_
== NULL
)
2602 this->cref_
= new Cref();
2603 this->cref_
->add_archive_start(archive
);
2607 // Stop processing an archive.
2610 Input_objects::archive_stop(Archive
* archive
)
2612 if (parameters
->options().user_set_print_symbol_counts()
2613 || parameters
->options().cref())
2614 this->cref_
->add_archive_stop(archive
);
2617 // Print symbol counts
2620 Input_objects::print_symbol_counts(const Symbol_table
* symtab
) const
2622 if (parameters
->options().user_set_print_symbol_counts()
2623 && this->cref_
!= NULL
)
2624 this->cref_
->print_symbol_counts(symtab
);
2627 // Print a cross reference table.
2630 Input_objects::print_cref(const Symbol_table
* symtab
, FILE* f
) const
2632 if (parameters
->options().cref() && this->cref_
!= NULL
)
2633 this->cref_
->print_cref(symtab
, f
);
2636 // Relocate_info methods.
2638 // Return a string describing the location of a relocation when file
2639 // and lineno information is not available. This is only used in
2642 template<int size
, bool big_endian
>
2644 Relocate_info
<size
, big_endian
>::location(size_t, off_t offset
) const
2646 Sized_dwarf_line_info
<size
, big_endian
> line_info(this->object
);
2647 std::string ret
= line_info
.addr2line(this->data_shndx
, offset
, NULL
);
2651 ret
= this->object
->name();
2653 Symbol_location_info info
;
2654 if (this->object
->get_symbol_location_info(this->data_shndx
, offset
, &info
))
2656 if (!info
.source_file
.empty())
2659 ret
+= info
.source_file
;
2661 size_t len
= info
.enclosing_symbol_name
.length() + 100;
2662 char* buf
= new char[len
];
2663 snprintf(buf
, len
, _(":function %s"),
2664 info
.enclosing_symbol_name
.c_str());
2671 ret
+= this->object
->section_name(this->data_shndx
);
2673 snprintf(buf
, sizeof buf
, "+0x%lx)", static_cast<long>(offset
));
2678 } // End namespace gold.
2683 using namespace gold
;
2685 // Read an ELF file with the header and return the appropriate
2686 // instance of Object.
2688 template<int size
, bool big_endian
>
2690 make_elf_sized_object(const std::string
& name
, Input_file
* input_file
,
2691 off_t offset
, const elfcpp::Ehdr
<size
, big_endian
>& ehdr
,
2692 bool* punconfigured
)
2694 Target
* target
= select_target(ehdr
.get_e_machine(), size
, big_endian
,
2695 ehdr
.get_e_ident()[elfcpp::EI_OSABI
],
2696 ehdr
.get_e_ident()[elfcpp::EI_ABIVERSION
]);
2698 gold_fatal(_("%s: unsupported ELF machine number %d"),
2699 name
.c_str(), ehdr
.get_e_machine());
2701 if (!parameters
->target_valid())
2702 set_parameters_target(target
);
2703 else if (target
!= ¶meters
->target())
2705 if (punconfigured
!= NULL
)
2706 *punconfigured
= true;
2708 gold_error(_("%s: incompatible target"), name
.c_str());
2712 return target
->make_elf_object
<size
, big_endian
>(name
, input_file
, offset
,
2716 } // End anonymous namespace.
2721 // Return whether INPUT_FILE is an ELF object.
2724 is_elf_object(Input_file
* input_file
, off_t offset
,
2725 const unsigned char** start
, int* read_size
)
2727 off_t filesize
= input_file
->file().filesize();
2728 int want
= elfcpp::Elf_recognizer::max_header_size
;
2729 if (filesize
- offset
< want
)
2730 want
= filesize
- offset
;
2732 const unsigned char* p
= input_file
->file().get_view(offset
, 0, want
,
2737 return elfcpp::Elf_recognizer::is_elf_file(p
, want
);
2740 // Read an ELF file and return the appropriate instance of Object.
2743 make_elf_object(const std::string
& name
, Input_file
* input_file
, off_t offset
,
2744 const unsigned char* p
, section_offset_type bytes
,
2745 bool* punconfigured
)
2747 if (punconfigured
!= NULL
)
2748 *punconfigured
= false;
2751 bool big_endian
= false;
2753 if (!elfcpp::Elf_recognizer::is_valid_header(p
, bytes
, &size
,
2754 &big_endian
, &error
))
2756 gold_error(_("%s: %s"), name
.c_str(), error
.c_str());
2764 #ifdef HAVE_TARGET_32_BIG
2765 elfcpp::Ehdr
<32, true> ehdr(p
);
2766 return make_elf_sized_object
<32, true>(name
, input_file
,
2767 offset
, ehdr
, punconfigured
);
2769 if (punconfigured
!= NULL
)
2770 *punconfigured
= true;
2772 gold_error(_("%s: not configured to support "
2773 "32-bit big-endian object"),
2780 #ifdef HAVE_TARGET_32_LITTLE
2781 elfcpp::Ehdr
<32, false> ehdr(p
);
2782 return make_elf_sized_object
<32, false>(name
, input_file
,
2783 offset
, ehdr
, punconfigured
);
2785 if (punconfigured
!= NULL
)
2786 *punconfigured
= true;
2788 gold_error(_("%s: not configured to support "
2789 "32-bit little-endian object"),
2795 else if (size
== 64)
2799 #ifdef HAVE_TARGET_64_BIG
2800 elfcpp::Ehdr
<64, true> ehdr(p
);
2801 return make_elf_sized_object
<64, true>(name
, input_file
,
2802 offset
, ehdr
, punconfigured
);
2804 if (punconfigured
!= NULL
)
2805 *punconfigured
= true;
2807 gold_error(_("%s: not configured to support "
2808 "64-bit big-endian object"),
2815 #ifdef HAVE_TARGET_64_LITTLE
2816 elfcpp::Ehdr
<64, false> ehdr(p
);
2817 return make_elf_sized_object
<64, false>(name
, input_file
,
2818 offset
, ehdr
, punconfigured
);
2820 if (punconfigured
!= NULL
)
2821 *punconfigured
= true;
2823 gold_error(_("%s: not configured to support "
2824 "64-bit little-endian object"),
2834 // Instantiate the templates we need.
2836 #ifdef HAVE_TARGET_32_LITTLE
2839 Object::read_section_data
<32, false>(elfcpp::Elf_file
<32, false, Object
>*,
2840 Read_symbols_data
*);
2843 #ifdef HAVE_TARGET_32_BIG
2846 Object::read_section_data
<32, true>(elfcpp::Elf_file
<32, true, Object
>*,
2847 Read_symbols_data
*);
2850 #ifdef HAVE_TARGET_64_LITTLE
2853 Object::read_section_data
<64, false>(elfcpp::Elf_file
<64, false, Object
>*,
2854 Read_symbols_data
*);
2857 #ifdef HAVE_TARGET_64_BIG
2860 Object::read_section_data
<64, true>(elfcpp::Elf_file
<64, true, Object
>*,
2861 Read_symbols_data
*);
2864 #ifdef HAVE_TARGET_32_LITTLE
2866 class Sized_relobj_file
<32, false>;
2869 #ifdef HAVE_TARGET_32_BIG
2871 class Sized_relobj_file
<32, true>;
2874 #ifdef HAVE_TARGET_64_LITTLE
2876 class Sized_relobj_file
<64, false>;
2879 #ifdef HAVE_TARGET_64_BIG
2881 class Sized_relobj_file
<64, true>;
2884 #ifdef HAVE_TARGET_32_LITTLE
2886 struct Relocate_info
<32, false>;
2889 #ifdef HAVE_TARGET_32_BIG
2891 struct Relocate_info
<32, true>;
2894 #ifdef HAVE_TARGET_64_LITTLE
2896 struct Relocate_info
<64, false>;
2899 #ifdef HAVE_TARGET_64_BIG
2901 struct Relocate_info
<64, true>;
2904 #ifdef HAVE_TARGET_32_LITTLE
2907 Xindex::initialize_symtab_xindex
<32, false>(Object
*, unsigned int);
2911 Xindex::read_symtab_xindex
<32, false>(Object
*, unsigned int,
2912 const unsigned char*);
2915 #ifdef HAVE_TARGET_32_BIG
2918 Xindex::initialize_symtab_xindex
<32, true>(Object
*, unsigned int);
2922 Xindex::read_symtab_xindex
<32, true>(Object
*, unsigned int,
2923 const unsigned char*);
2926 #ifdef HAVE_TARGET_64_LITTLE
2929 Xindex::initialize_symtab_xindex
<64, false>(Object
*, unsigned int);
2933 Xindex::read_symtab_xindex
<64, false>(Object
*, unsigned int,
2934 const unsigned char*);
2937 #ifdef HAVE_TARGET_64_BIG
2940 Xindex::initialize_symtab_xindex
<64, true>(Object
*, unsigned int);
2944 Xindex::read_symtab_xindex
<64, true>(Object
*, unsigned int,
2945 const unsigned char*);
2948 } // End namespace gold.