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_()
424 this->e_type_
= ehdr
.get_e_type();
427 template<int size
, bool big_endian
>
428 Sized_relobj_file
<size
, big_endian
>::~Sized_relobj_file()
432 // Set up an object file based on the file header. This sets up the
433 // section information.
435 template<int size
, bool big_endian
>
437 Sized_relobj_file
<size
, big_endian
>::do_setup()
439 const unsigned int shnum
= this->elf_file_
.shnum();
440 this->set_shnum(shnum
);
443 // Find the SHT_SYMTAB section, given the section headers. The ELF
444 // standard says that maybe in the future there can be more than one
445 // SHT_SYMTAB section. Until somebody figures out how that could
446 // work, we assume there is only one.
448 template<int size
, bool big_endian
>
450 Sized_relobj_file
<size
, big_endian
>::find_symtab(const unsigned char* pshdrs
)
452 const unsigned int shnum
= this->shnum();
453 this->symtab_shndx_
= 0;
456 // Look through the sections in reverse order, since gas tends
457 // to put the symbol table at the end.
458 const unsigned char* p
= pshdrs
+ shnum
* This::shdr_size
;
459 unsigned int i
= shnum
;
460 unsigned int xindex_shndx
= 0;
461 unsigned int xindex_link
= 0;
465 p
-= This::shdr_size
;
466 typename
This::Shdr
shdr(p
);
467 if (shdr
.get_sh_type() == elfcpp::SHT_SYMTAB
)
469 this->symtab_shndx_
= i
;
470 if (xindex_shndx
> 0 && xindex_link
== i
)
473 new Xindex(this->elf_file_
.large_shndx_offset());
474 xindex
->read_symtab_xindex
<size
, big_endian
>(this,
477 this->set_xindex(xindex
);
482 // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
483 // one. This will work if it follows the SHT_SYMTAB
485 if (shdr
.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX
)
488 xindex_link
= this->adjust_shndx(shdr
.get_sh_link());
494 // Return the Xindex structure to use for object with lots of
497 template<int size
, bool big_endian
>
499 Sized_relobj_file
<size
, big_endian
>::do_initialize_xindex()
501 gold_assert(this->symtab_shndx_
!= -1U);
502 Xindex
* xindex
= new Xindex(this->elf_file_
.large_shndx_offset());
503 xindex
->initialize_symtab_xindex
<size
, big_endian
>(this, this->symtab_shndx_
);
507 // Return whether SHDR has the right type and flags to be a GNU
508 // .eh_frame section.
510 template<int size
, bool big_endian
>
512 Sized_relobj_file
<size
, big_endian
>::check_eh_frame_flags(
513 const elfcpp::Shdr
<size
, big_endian
>* shdr
) const
515 elfcpp::Elf_Word sh_type
= shdr
->get_sh_type();
516 return ((sh_type
== elfcpp::SHT_PROGBITS
517 || sh_type
== elfcpp::SHT_X86_64_UNWIND
)
518 && (shdr
->get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
521 // Return whether there is a GNU .eh_frame section, given the section
522 // headers and the section names.
524 template<int size
, bool big_endian
>
526 Sized_relobj_file
<size
, big_endian
>::find_eh_frame(
527 const unsigned char* pshdrs
,
529 section_size_type names_size
) const
531 const unsigned int shnum
= this->shnum();
532 const unsigned char* p
= pshdrs
+ This::shdr_size
;
533 for (unsigned int i
= 1; i
< shnum
; ++i
, p
+= This::shdr_size
)
535 typename
This::Shdr
shdr(p
);
536 if (this->check_eh_frame_flags(&shdr
))
538 if (shdr
.get_sh_name() >= names_size
)
540 this->error(_("bad section name offset for section %u: %lu"),
541 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
545 const char* name
= names
+ shdr
.get_sh_name();
546 if (strcmp(name
, ".eh_frame") == 0)
553 // Build a table for any compressed debug sections, mapping each section index
554 // to the uncompressed size.
556 template<int size
, bool big_endian
>
557 Compressed_section_map
*
558 build_compressed_section_map(
559 const unsigned char* pshdrs
,
562 section_size_type names_size
,
563 Sized_relobj_file
<size
, big_endian
>* obj
)
565 Compressed_section_map
* uncompressed_sizes
= new Compressed_section_map();
566 const unsigned int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
567 const unsigned char* p
= pshdrs
+ shdr_size
;
568 for (unsigned int i
= 1; i
< shnum
; ++i
, p
+= shdr_size
)
570 typename
elfcpp::Shdr
<size
, big_endian
> shdr(p
);
571 if (shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
572 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
574 if (shdr
.get_sh_name() >= names_size
)
576 obj
->error(_("bad section name offset for section %u: %lu"),
577 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
581 const char* name
= names
+ shdr
.get_sh_name();
582 if (is_compressed_debug_section(name
))
584 section_size_type len
;
585 const unsigned char* contents
=
586 obj
->section_contents(i
, &len
, false);
587 uint64_t uncompressed_size
= get_uncompressed_size(contents
, len
);
588 if (uncompressed_size
!= -1ULL)
589 (*uncompressed_sizes
)[i
] =
590 convert_to_section_size_type(uncompressed_size
);
594 return uncompressed_sizes
;
597 // Read the sections and symbols from an object file.
599 template<int size
, bool big_endian
>
601 Sized_relobj_file
<size
, big_endian
>::do_read_symbols(Read_symbols_data
* sd
)
603 this->read_section_data(&this->elf_file_
, sd
);
605 const unsigned char* const pshdrs
= sd
->section_headers
->data();
607 this->find_symtab(pshdrs
);
609 const unsigned char* namesu
= sd
->section_names
->data();
610 const char* names
= reinterpret_cast<const char*>(namesu
);
611 if (memmem(names
, sd
->section_names_size
, ".eh_frame", 10) != NULL
)
613 if (this->find_eh_frame(pshdrs
, names
, sd
->section_names_size
))
614 this->has_eh_frame_
= true;
616 if (memmem(names
, sd
->section_names_size
, ".zdebug_", 8) != NULL
)
617 this->compressed_sections_
=
618 build_compressed_section_map(pshdrs
, this->shnum(), names
,
619 sd
->section_names_size
, this);
622 sd
->symbols_size
= 0;
623 sd
->external_symbols_offset
= 0;
624 sd
->symbol_names
= NULL
;
625 sd
->symbol_names_size
= 0;
627 if (this->symtab_shndx_
== 0)
629 // No symbol table. Weird but legal.
633 // Get the symbol table section header.
634 typename
This::Shdr
symtabshdr(pshdrs
635 + this->symtab_shndx_
* This::shdr_size
);
636 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
638 // If this object has a .eh_frame section, we need all the symbols.
639 // Otherwise we only need the external symbols. While it would be
640 // simpler to just always read all the symbols, I've seen object
641 // files with well over 2000 local symbols, which for a 64-bit
642 // object file format is over 5 pages that we don't need to read
645 const int sym_size
= This::sym_size
;
646 const unsigned int loccount
= symtabshdr
.get_sh_info();
647 this->local_symbol_count_
= loccount
;
648 this->local_values_
.resize(loccount
);
649 section_offset_type locsize
= loccount
* sym_size
;
650 off_t dataoff
= symtabshdr
.get_sh_offset();
651 section_size_type datasize
=
652 convert_to_section_size_type(symtabshdr
.get_sh_size());
653 off_t extoff
= dataoff
+ locsize
;
654 section_size_type extsize
= datasize
- locsize
;
656 off_t readoff
= this->has_eh_frame_
? dataoff
: extoff
;
657 section_size_type readsize
= this->has_eh_frame_
? datasize
: extsize
;
661 // No external symbols. Also weird but also legal.
665 File_view
* fvsymtab
= this->get_lasting_view(readoff
, readsize
, true, false);
667 // Read the section header for the symbol names.
668 unsigned int strtab_shndx
= this->adjust_shndx(symtabshdr
.get_sh_link());
669 if (strtab_shndx
>= this->shnum())
671 this->error(_("invalid symbol table name index: %u"), strtab_shndx
);
674 typename
This::Shdr
strtabshdr(pshdrs
+ strtab_shndx
* This::shdr_size
);
675 if (strtabshdr
.get_sh_type() != elfcpp::SHT_STRTAB
)
677 this->error(_("symbol table name section has wrong type: %u"),
678 static_cast<unsigned int>(strtabshdr
.get_sh_type()));
682 // Read the symbol names.
683 File_view
* fvstrtab
= this->get_lasting_view(strtabshdr
.get_sh_offset(),
684 strtabshdr
.get_sh_size(),
687 sd
->symbols
= fvsymtab
;
688 sd
->symbols_size
= readsize
;
689 sd
->external_symbols_offset
= this->has_eh_frame_
? locsize
: 0;
690 sd
->symbol_names
= fvstrtab
;
691 sd
->symbol_names_size
=
692 convert_to_section_size_type(strtabshdr
.get_sh_size());
695 // Return the section index of symbol SYM. Set *VALUE to its value in
696 // the object file. Set *IS_ORDINARY if this is an ordinary section
697 // index, not a special code between SHN_LORESERVE and SHN_HIRESERVE.
698 // Note that for a symbol which is not defined in this object file,
699 // this will set *VALUE to 0 and return SHN_UNDEF; it will not return
700 // the final value of the symbol in the link.
702 template<int size
, bool big_endian
>
704 Sized_relobj_file
<size
, big_endian
>::symbol_section_and_value(unsigned int sym
,
708 section_size_type symbols_size
;
709 const unsigned char* symbols
= this->section_contents(this->symtab_shndx_
,
713 const size_t count
= symbols_size
/ This::sym_size
;
714 gold_assert(sym
< count
);
716 elfcpp::Sym
<size
, big_endian
> elfsym(symbols
+ sym
* This::sym_size
);
717 *value
= elfsym
.get_st_value();
719 return this->adjust_sym_shndx(sym
, elfsym
.get_st_shndx(), is_ordinary
);
722 // Return whether to include a section group in the link. LAYOUT is
723 // used to keep track of which section groups we have already seen.
724 // INDEX is the index of the section group and SHDR is the section
725 // header. If we do not want to include this group, we set bits in
726 // OMIT for each section which should be discarded.
728 template<int size
, bool big_endian
>
730 Sized_relobj_file
<size
, big_endian
>::include_section_group(
731 Symbol_table
* symtab
,
735 const unsigned char* shdrs
,
736 const char* section_names
,
737 section_size_type section_names_size
,
738 std::vector
<bool>* omit
)
740 // Read the section contents.
741 typename
This::Shdr
shdr(shdrs
+ index
* This::shdr_size
);
742 const unsigned char* pcon
= this->get_view(shdr
.get_sh_offset(),
743 shdr
.get_sh_size(), true, false);
744 const elfcpp::Elf_Word
* pword
=
745 reinterpret_cast<const elfcpp::Elf_Word
*>(pcon
);
747 // The first word contains flags. We only care about COMDAT section
748 // groups. Other section groups are always included in the link
749 // just like ordinary sections.
750 elfcpp::Elf_Word flags
= elfcpp::Swap
<32, big_endian
>::readval(pword
);
752 // Look up the group signature, which is the name of a symbol. ELF
753 // uses a symbol name because some group signatures are long, and
754 // the name is generally already in the symbol table, so it makes
755 // sense to put the long string just once in .strtab rather than in
756 // both .strtab and .shstrtab.
758 // Get the appropriate symbol table header (this will normally be
759 // the single SHT_SYMTAB section, but in principle it need not be).
760 const unsigned int link
= this->adjust_shndx(shdr
.get_sh_link());
761 typename
This::Shdr
symshdr(this, this->elf_file_
.section_header(link
));
763 // Read the symbol table entry.
764 unsigned int symndx
= shdr
.get_sh_info();
765 if (symndx
>= symshdr
.get_sh_size() / This::sym_size
)
767 this->error(_("section group %u info %u out of range"),
771 off_t symoff
= symshdr
.get_sh_offset() + symndx
* This::sym_size
;
772 const unsigned char* psym
= this->get_view(symoff
, This::sym_size
, true,
774 elfcpp::Sym
<size
, big_endian
> sym(psym
);
776 // Read the symbol table names.
777 section_size_type symnamelen
;
778 const unsigned char* psymnamesu
;
779 psymnamesu
= this->section_contents(this->adjust_shndx(symshdr
.get_sh_link()),
781 const char* psymnames
= reinterpret_cast<const char*>(psymnamesu
);
783 // Get the section group signature.
784 if (sym
.get_st_name() >= symnamelen
)
786 this->error(_("symbol %u name offset %u out of range"),
787 symndx
, sym
.get_st_name());
791 std::string
signature(psymnames
+ sym
.get_st_name());
793 // It seems that some versions of gas will create a section group
794 // associated with a section symbol, and then fail to give a name to
795 // the section symbol. In such a case, use the name of the section.
796 if (signature
[0] == '\0' && sym
.get_st_type() == elfcpp::STT_SECTION
)
799 unsigned int sym_shndx
= this->adjust_sym_shndx(symndx
,
802 if (!is_ordinary
|| sym_shndx
>= this->shnum())
804 this->error(_("symbol %u invalid section index %u"),
808 typename
This::Shdr
member_shdr(shdrs
+ sym_shndx
* This::shdr_size
);
809 if (member_shdr
.get_sh_name() < section_names_size
)
810 signature
= section_names
+ member_shdr
.get_sh_name();
813 // Record this section group in the layout, and see whether we've already
814 // seen one with the same signature.
817 Kept_section
* kept_section
= NULL
;
819 if ((flags
& elfcpp::GRP_COMDAT
) == 0)
821 include_group
= true;
826 include_group
= layout
->find_or_add_kept_section(signature
,
828 true, &kept_section
);
832 if (is_comdat
&& include_group
)
834 Incremental_inputs
* incremental_inputs
= layout
->incremental_inputs();
835 if (incremental_inputs
!= NULL
)
836 incremental_inputs
->report_comdat_group(this, signature
.c_str());
839 size_t count
= shdr
.get_sh_size() / sizeof(elfcpp::Elf_Word
);
841 std::vector
<unsigned int> shndxes
;
842 bool relocate_group
= include_group
&& parameters
->options().relocatable();
844 shndxes
.reserve(count
- 1);
846 for (size_t i
= 1; i
< count
; ++i
)
848 elfcpp::Elf_Word shndx
=
849 this->adjust_shndx(elfcpp::Swap
<32, big_endian
>::readval(pword
+ i
));
852 shndxes
.push_back(shndx
);
854 if (shndx
>= this->shnum())
856 this->error(_("section %u in section group %u out of range"),
861 // Check for an earlier section number, since we're going to get
862 // it wrong--we may have already decided to include the section.
864 this->error(_("invalid section group %u refers to earlier section %u"),
867 // Get the name of the member section.
868 typename
This::Shdr
member_shdr(shdrs
+ shndx
* This::shdr_size
);
869 if (member_shdr
.get_sh_name() >= section_names_size
)
871 // This is an error, but it will be diagnosed eventually
872 // in do_layout, so we don't need to do anything here but
876 std::string
mname(section_names
+ member_shdr
.get_sh_name());
881 kept_section
->add_comdat_section(mname
, shndx
,
882 member_shdr
.get_sh_size());
886 (*omit
)[shndx
] = true;
890 Relobj
* kept_object
= kept_section
->object();
891 if (kept_section
->is_comdat())
893 // Find the corresponding kept section, and store
894 // that info in the discarded section table.
895 unsigned int kept_shndx
;
897 if (kept_section
->find_comdat_section(mname
, &kept_shndx
,
900 // We don't keep a mapping for this section if
901 // it has a different size. The mapping is only
902 // used for relocation processing, and we don't
903 // want to treat the sections as similar if the
904 // sizes are different. Checking the section
905 // size is the approach used by the GNU linker.
906 if (kept_size
== member_shdr
.get_sh_size())
907 this->set_kept_comdat_section(shndx
, kept_object
,
913 // The existing section is a linkonce section. Add
914 // a mapping if there is exactly one section in the
915 // group (which is true when COUNT == 2) and if it
918 && (kept_section
->linkonce_size()
919 == member_shdr
.get_sh_size()))
920 this->set_kept_comdat_section(shndx
, kept_object
,
921 kept_section
->shndx());
928 layout
->layout_group(symtab
, this, index
, name
, signature
.c_str(),
929 shdr
, flags
, &shndxes
);
931 return include_group
;
934 // Whether to include a linkonce section in the link. NAME is the
935 // name of the section and SHDR is the section header.
937 // Linkonce sections are a GNU extension implemented in the original
938 // GNU linker before section groups were defined. The semantics are
939 // that we only include one linkonce section with a given name. The
940 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
941 // where T is the type of section and SYMNAME is the name of a symbol.
942 // In an attempt to make linkonce sections interact well with section
943 // groups, we try to identify SYMNAME and use it like a section group
944 // signature. We want to block section groups with that signature,
945 // but not other linkonce sections with that signature. We also use
946 // the full name of the linkonce section as a normal section group
949 template<int size
, bool big_endian
>
951 Sized_relobj_file
<size
, big_endian
>::include_linkonce_section(
955 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
957 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
958 // In general the symbol name we want will be the string following
959 // the last '.'. However, we have to handle the case of
960 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
961 // some versions of gcc. So we use a heuristic: if the name starts
962 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
963 // we look for the last '.'. We can't always simply skip
964 // ".gnu.linkonce.X", because we have to deal with cases like
965 // ".gnu.linkonce.d.rel.ro.local".
966 const char* const linkonce_t
= ".gnu.linkonce.t.";
968 if (strncmp(name
, linkonce_t
, strlen(linkonce_t
)) == 0)
969 symname
= name
+ strlen(linkonce_t
);
971 symname
= strrchr(name
, '.') + 1;
972 std::string
sig1(symname
);
973 std::string
sig2(name
);
976 bool include1
= layout
->find_or_add_kept_section(sig1
, this, index
, false,
978 bool include2
= layout
->find_or_add_kept_section(sig2
, this, index
, false,
983 // We are not including this section because we already saw the
984 // name of the section as a signature. This normally implies
985 // that the kept section is another linkonce section. If it is
986 // the same size, record it as the section which corresponds to
988 if (kept2
->object() != NULL
989 && !kept2
->is_comdat()
990 && kept2
->linkonce_size() == sh_size
)
991 this->set_kept_comdat_section(index
, kept2
->object(), kept2
->shndx());
995 // The section is being discarded on the basis of its symbol
996 // name. This means that the corresponding kept section was
997 // part of a comdat group, and it will be difficult to identify
998 // the specific section within that group that corresponds to
999 // this linkonce section. We'll handle the simple case where
1000 // the group has only one member section. Otherwise, it's not
1001 // worth the effort.
1002 unsigned int kept_shndx
;
1004 if (kept1
->object() != NULL
1005 && kept1
->is_comdat()
1006 && kept1
->find_single_comdat_section(&kept_shndx
, &kept_size
)
1007 && kept_size
== sh_size
)
1008 this->set_kept_comdat_section(index
, kept1
->object(), kept_shndx
);
1012 kept1
->set_linkonce_size(sh_size
);
1013 kept2
->set_linkonce_size(sh_size
);
1016 return include1
&& include2
;
1019 // Layout an input section.
1021 template<int size
, bool big_endian
>
1023 Sized_relobj_file
<size
, big_endian
>::layout_section(
1027 const typename
This::Shdr
& shdr
,
1028 unsigned int reloc_shndx
,
1029 unsigned int reloc_type
)
1032 Output_section
* os
= layout
->layout(this, shndx
, name
, shdr
,
1033 reloc_shndx
, reloc_type
, &offset
);
1035 this->output_sections()[shndx
] = os
;
1037 this->section_offsets()[shndx
] = invalid_address
;
1039 this->section_offsets()[shndx
] = convert_types
<Address
, off_t
>(offset
);
1041 // If this section requires special handling, and if there are
1042 // relocs that apply to it, then we must do the special handling
1043 // before we apply the relocs.
1044 if (offset
== -1 && reloc_shndx
!= 0)
1045 this->set_relocs_must_follow_section_writes();
1048 // Layout an input .eh_frame section.
1050 template<int size
, bool big_endian
>
1052 Sized_relobj_file
<size
, big_endian
>::layout_eh_frame_section(
1054 const unsigned char* symbols_data
,
1055 section_size_type symbols_size
,
1056 const unsigned char* symbol_names_data
,
1057 section_size_type symbol_names_size
,
1059 const typename
This::Shdr
& shdr
,
1060 unsigned int reloc_shndx
,
1061 unsigned int reloc_type
)
1063 gold_assert(this->has_eh_frame_
);
1066 Output_section
* os
= layout
->layout_eh_frame(this,
1076 this->output_sections()[shndx
] = os
;
1077 if (os
== NULL
|| offset
== -1)
1079 // An object can contain at most one section holding exception
1080 // frame information.
1081 gold_assert(this->discarded_eh_frame_shndx_
== -1U);
1082 this->discarded_eh_frame_shndx_
= shndx
;
1083 this->section_offsets()[shndx
] = invalid_address
;
1086 this->section_offsets()[shndx
] = convert_types
<Address
, off_t
>(offset
);
1088 // If this section requires special handling, and if there are
1089 // relocs that aply to it, then we must do the special handling
1090 // before we apply the relocs.
1091 if (os
!= NULL
&& offset
== -1 && reloc_shndx
!= 0)
1092 this->set_relocs_must_follow_section_writes();
1095 // Lay out the input sections. We walk through the sections and check
1096 // whether they should be included in the link. If they should, we
1097 // pass them to the Layout object, which will return an output section
1099 // During garbage collection (--gc-sections) and identical code folding
1100 // (--icf), this function is called twice. When it is called the first
1101 // time, it is for setting up some sections as roots to a work-list for
1102 // --gc-sections and to do comdat processing. Actual layout happens the
1103 // second time around after all the relevant sections have been determined.
1104 // The first time, is_worklist_ready or is_icf_ready is false. It is then
1105 // set to true after the garbage collection worklist or identical code
1106 // folding is processed and the relevant sections to be kept are
1107 // determined. Then, this function is called again to layout the sections.
1109 template<int size
, bool big_endian
>
1111 Sized_relobj_file
<size
, big_endian
>::do_layout(Symbol_table
* symtab
,
1113 Read_symbols_data
* sd
)
1115 const unsigned int shnum
= this->shnum();
1116 bool is_gc_pass_one
= ((parameters
->options().gc_sections()
1117 && !symtab
->gc()->is_worklist_ready())
1118 || (parameters
->options().icf_enabled()
1119 && !symtab
->icf()->is_icf_ready()));
1121 bool is_gc_pass_two
= ((parameters
->options().gc_sections()
1122 && symtab
->gc()->is_worklist_ready())
1123 || (parameters
->options().icf_enabled()
1124 && symtab
->icf()->is_icf_ready()));
1126 bool is_gc_or_icf
= (parameters
->options().gc_sections()
1127 || parameters
->options().icf_enabled());
1129 // Both is_gc_pass_one and is_gc_pass_two should not be true.
1130 gold_assert(!(is_gc_pass_one
&& is_gc_pass_two
));
1134 Symbols_data
* gc_sd
= NULL
;
1137 // During garbage collection save the symbols data to use it when
1138 // re-entering this function.
1139 gc_sd
= new Symbols_data
;
1140 this->copy_symbols_data(gc_sd
, sd
, This::shdr_size
* shnum
);
1141 this->set_symbols_data(gc_sd
);
1143 else if (is_gc_pass_two
)
1145 gc_sd
= this->get_symbols_data();
1148 const unsigned char* section_headers_data
= NULL
;
1149 section_size_type section_names_size
;
1150 const unsigned char* symbols_data
= NULL
;
1151 section_size_type symbols_size
;
1152 const unsigned char* symbol_names_data
= NULL
;
1153 section_size_type symbol_names_size
;
1157 section_headers_data
= gc_sd
->section_headers_data
;
1158 section_names_size
= gc_sd
->section_names_size
;
1159 symbols_data
= gc_sd
->symbols_data
;
1160 symbols_size
= gc_sd
->symbols_size
;
1161 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 if (sd
->symbol_names
!= NULL
)
1172 symbol_names_data
= sd
->symbol_names
->data();
1173 symbol_names_size
= sd
->symbol_names_size
;
1176 // Get the section headers.
1177 const unsigned char* shdrs
= section_headers_data
;
1178 const unsigned char* pshdrs
;
1180 // Get the section names.
1181 const unsigned char* pnamesu
= (is_gc_or_icf
)
1182 ? gc_sd
->section_names_data
1183 : sd
->section_names
->data();
1185 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
1187 // If any input files have been claimed by plugins, we need to defer
1188 // actual layout until the replacement files have arrived.
1189 const bool should_defer_layout
=
1190 (parameters
->options().has_plugins()
1191 && parameters
->options().plugins()->should_defer_layout());
1192 unsigned int num_sections_to_defer
= 0;
1194 // For each section, record the index of the reloc section if any.
1195 // Use 0 to mean that there is no reloc section, -1U to mean that
1196 // there is more than one.
1197 std::vector
<unsigned int> reloc_shndx(shnum
, 0);
1198 std::vector
<unsigned int> reloc_type(shnum
, elfcpp::SHT_NULL
);
1199 // Skip the first, dummy, section.
1200 pshdrs
= shdrs
+ This::shdr_size
;
1201 for (unsigned int i
= 1; i
< shnum
; ++i
, pshdrs
+= This::shdr_size
)
1203 typename
This::Shdr
shdr(pshdrs
);
1205 // Count the number of sections whose layout will be deferred.
1206 if (should_defer_layout
&& (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
))
1207 ++num_sections_to_defer
;
1209 unsigned int sh_type
= shdr
.get_sh_type();
1210 if (sh_type
== elfcpp::SHT_REL
|| sh_type
== elfcpp::SHT_RELA
)
1212 unsigned int target_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1213 if (target_shndx
== 0 || target_shndx
>= shnum
)
1215 this->error(_("relocation section %u has bad info %u"),
1220 if (reloc_shndx
[target_shndx
] != 0)
1221 reloc_shndx
[target_shndx
] = -1U;
1224 reloc_shndx
[target_shndx
] = i
;
1225 reloc_type
[target_shndx
] = sh_type
;
1230 Output_sections
& out_sections(this->output_sections());
1231 std::vector
<Address
>& out_section_offsets(this->section_offsets());
1233 if (!is_gc_pass_two
)
1235 out_sections
.resize(shnum
);
1236 out_section_offsets
.resize(shnum
);
1239 // If we are only linking for symbols, then there is nothing else to
1241 if (this->input_file()->just_symbols())
1243 if (!is_gc_pass_two
)
1245 delete sd
->section_headers
;
1246 sd
->section_headers
= NULL
;
1247 delete sd
->section_names
;
1248 sd
->section_names
= NULL
;
1253 if (num_sections_to_defer
> 0)
1255 parameters
->options().plugins()->add_deferred_layout_object(this);
1256 this->deferred_layout_
.reserve(num_sections_to_defer
);
1259 // Whether we've seen a .note.GNU-stack section.
1260 bool seen_gnu_stack
= false;
1261 // The flags of a .note.GNU-stack section.
1262 uint64_t gnu_stack_flags
= 0;
1264 // Keep track of which sections to omit.
1265 std::vector
<bool> omit(shnum
, false);
1267 // Keep track of reloc sections when emitting relocations.
1268 const bool relocatable
= parameters
->options().relocatable();
1269 const bool emit_relocs
= (relocatable
1270 || parameters
->options().emit_relocs());
1271 std::vector
<unsigned int> reloc_sections
;
1273 // Keep track of .eh_frame sections.
1274 std::vector
<unsigned int> eh_frame_sections
;
1276 // Skip the first, dummy, section.
1277 pshdrs
= shdrs
+ This::shdr_size
;
1278 for (unsigned int i
= 1; i
< shnum
; ++i
, pshdrs
+= This::shdr_size
)
1280 typename
This::Shdr
shdr(pshdrs
);
1282 if (shdr
.get_sh_name() >= section_names_size
)
1284 this->error(_("bad section name offset for section %u: %lu"),
1285 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
1289 const char* name
= pnames
+ shdr
.get_sh_name();
1291 if (!is_gc_pass_two
)
1293 if (this->handle_gnu_warning_section(name
, i
, symtab
))
1295 if (!relocatable
&& !parameters
->options().shared())
1299 // The .note.GNU-stack section is special. It gives the
1300 // protection flags that this object file requires for the stack
1302 if (strcmp(name
, ".note.GNU-stack") == 0)
1304 seen_gnu_stack
= true;
1305 gnu_stack_flags
|= shdr
.get_sh_flags();
1309 // The .note.GNU-split-stack section is also special. It
1310 // indicates that the object was compiled with
1312 if (this->handle_split_stack_section(name
))
1314 if (!relocatable
&& !parameters
->options().shared())
1318 // Skip attributes section.
1319 if (parameters
->target().is_attributes_section(name
))
1324 bool discard
= omit
[i
];
1327 if (shdr
.get_sh_type() == elfcpp::SHT_GROUP
)
1329 if (!this->include_section_group(symtab
, layout
, i
, name
,
1335 else if ((shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) == 0
1336 && Layout::is_linkonce(name
))
1338 if (!this->include_linkonce_section(layout
, i
, name
, shdr
))
1343 // Add the section to the incremental inputs layout.
1344 Incremental_inputs
* incremental_inputs
= layout
->incremental_inputs();
1345 if (incremental_inputs
!= NULL
1347 && (shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
1348 || shdr
.get_sh_type() == elfcpp::SHT_NOBITS
1349 || shdr
.get_sh_type() == elfcpp::SHT_NOTE
))
1351 off_t sh_size
= shdr
.get_sh_size();
1352 section_size_type uncompressed_size
;
1353 if (this->section_is_compressed(i
, &uncompressed_size
))
1354 sh_size
= uncompressed_size
;
1355 incremental_inputs
->report_input_section(this, i
, name
, sh_size
);
1360 // Do not include this section in the link.
1361 out_sections
[i
] = NULL
;
1362 out_section_offsets
[i
] = invalid_address
;
1367 if (is_gc_pass_one
&& parameters
->options().gc_sections())
1369 if (this->is_section_name_included(name
)
1370 || shdr
.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1371 || shdr
.get_sh_type() == elfcpp::SHT_FINI_ARRAY
)
1373 symtab
->gc()->worklist().push(Section_id(this, i
));
1375 // If the section name XXX can be represented as a C identifier
1376 // it cannot be discarded if there are references to
1377 // __start_XXX and __stop_XXX symbols. These need to be
1378 // specially handled.
1379 if (is_cident(name
))
1381 symtab
->gc()->add_cident_section(name
, Section_id(this, i
));
1385 // When doing a relocatable link we are going to copy input
1386 // reloc sections into the output. We only want to copy the
1387 // ones associated with sections which are not being discarded.
1388 // However, we don't know that yet for all sections. So save
1389 // reloc sections and process them later. Garbage collection is
1390 // not triggered when relocatable code is desired.
1392 && (shdr
.get_sh_type() == elfcpp::SHT_REL
1393 || shdr
.get_sh_type() == elfcpp::SHT_RELA
))
1395 reloc_sections
.push_back(i
);
1399 if (relocatable
&& shdr
.get_sh_type() == elfcpp::SHT_GROUP
)
1402 // The .eh_frame section is special. It holds exception frame
1403 // information that we need to read in order to generate the
1404 // exception frame header. We process these after all the other
1405 // sections so that the exception frame reader can reliably
1406 // determine which sections are being discarded, and discard the
1407 // corresponding information.
1409 && strcmp(name
, ".eh_frame") == 0
1410 && this->check_eh_frame_flags(&shdr
))
1414 out_sections
[i
] = reinterpret_cast<Output_section
*>(1);
1415 out_section_offsets
[i
] = invalid_address
;
1417 else if (should_defer_layout
)
1418 this->deferred_layout_
.push_back(Deferred_layout(i
, name
,
1423 eh_frame_sections
.push_back(i
);
1427 if (is_gc_pass_two
&& parameters
->options().gc_sections())
1429 // This is executed during the second pass of garbage
1430 // collection. do_layout has been called before and some
1431 // sections have been already discarded. Simply ignore
1432 // such sections this time around.
1433 if (out_sections
[i
] == NULL
)
1435 gold_assert(out_section_offsets
[i
] == invalid_address
);
1438 if (((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0)
1439 && symtab
->gc()->is_section_garbage(this, i
))
1441 if (parameters
->options().print_gc_sections())
1442 gold_info(_("%s: removing unused section from '%s'"
1444 program_name
, this->section_name(i
).c_str(),
1445 this->name().c_str());
1446 out_sections
[i
] = NULL
;
1447 out_section_offsets
[i
] = invalid_address
;
1452 if (is_gc_pass_two
&& parameters
->options().icf_enabled())
1454 if (out_sections
[i
] == NULL
)
1456 gold_assert(out_section_offsets
[i
] == invalid_address
);
1459 if (((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0)
1460 && symtab
->icf()->is_section_folded(this, i
))
1462 if (parameters
->options().print_icf_sections())
1465 symtab
->icf()->get_folded_section(this, i
);
1466 Relobj
* folded_obj
=
1467 reinterpret_cast<Relobj
*>(folded
.first
);
1468 gold_info(_("%s: ICF folding section '%s' in file '%s'"
1469 "into '%s' in file '%s'"),
1470 program_name
, this->section_name(i
).c_str(),
1471 this->name().c_str(),
1472 folded_obj
->section_name(folded
.second
).c_str(),
1473 folded_obj
->name().c_str());
1475 out_sections
[i
] = NULL
;
1476 out_section_offsets
[i
] = invalid_address
;
1481 // Defer layout here if input files are claimed by plugins. When gc
1482 // is turned on this function is called twice. For the second call
1483 // should_defer_layout should be false.
1484 if (should_defer_layout
&& (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
))
1486 gold_assert(!is_gc_pass_two
);
1487 this->deferred_layout_
.push_back(Deferred_layout(i
, name
,
1491 // Put dummy values here; real values will be supplied by
1492 // do_layout_deferred_sections.
1493 out_sections
[i
] = reinterpret_cast<Output_section
*>(2);
1494 out_section_offsets
[i
] = invalid_address
;
1498 // During gc_pass_two if a section that was previously deferred is
1499 // found, do not layout the section as layout_deferred_sections will
1500 // do it later from gold.cc.
1502 && (out_sections
[i
] == reinterpret_cast<Output_section
*>(2)))
1507 // This is during garbage collection. The out_sections are
1508 // assigned in the second call to this function.
1509 out_sections
[i
] = reinterpret_cast<Output_section
*>(1);
1510 out_section_offsets
[i
] = invalid_address
;
1514 // When garbage collection is switched on the actual layout
1515 // only happens in the second call.
1516 this->layout_section(layout
, i
, name
, shdr
, reloc_shndx
[i
],
1521 if (!is_gc_pass_two
)
1522 layout
->layout_gnu_stack(seen_gnu_stack
, gnu_stack_flags
, this);
1524 // When doing a relocatable link handle the reloc sections at the
1525 // end. Garbage collection and Identical Code Folding is not
1526 // turned on for relocatable code.
1528 this->size_relocatable_relocs();
1530 gold_assert(!(is_gc_or_icf
) || reloc_sections
.empty());
1532 for (std::vector
<unsigned int>::const_iterator p
= reloc_sections
.begin();
1533 p
!= reloc_sections
.end();
1536 unsigned int i
= *p
;
1537 const unsigned char* pshdr
;
1538 pshdr
= section_headers_data
+ i
* This::shdr_size
;
1539 typename
This::Shdr
shdr(pshdr
);
1541 unsigned int data_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1542 if (data_shndx
>= shnum
)
1544 // We already warned about this above.
1548 Output_section
* data_section
= out_sections
[data_shndx
];
1549 if (data_section
== reinterpret_cast<Output_section
*>(2))
1551 // The layout for the data section was deferred, so we need
1552 // to defer the relocation section, too.
1553 const char* name
= pnames
+ shdr
.get_sh_name();
1554 this->deferred_layout_relocs_
.push_back(
1555 Deferred_layout(i
, name
, pshdr
, 0, elfcpp::SHT_NULL
));
1556 out_sections
[i
] = reinterpret_cast<Output_section
*>(2);
1557 out_section_offsets
[i
] = invalid_address
;
1560 if (data_section
== NULL
)
1562 out_sections
[i
] = NULL
;
1563 out_section_offsets
[i
] = invalid_address
;
1567 Relocatable_relocs
* rr
= new Relocatable_relocs();
1568 this->set_relocatable_relocs(i
, rr
);
1570 Output_section
* os
= layout
->layout_reloc(this, i
, shdr
, data_section
,
1572 out_sections
[i
] = os
;
1573 out_section_offsets
[i
] = invalid_address
;
1576 // Handle the .eh_frame sections at the end.
1577 gold_assert(!is_gc_pass_one
|| eh_frame_sections
.empty());
1578 for (std::vector
<unsigned int>::const_iterator p
= eh_frame_sections
.begin();
1579 p
!= eh_frame_sections
.end();
1582 unsigned int i
= *p
;
1583 const unsigned char* pshdr
;
1584 pshdr
= section_headers_data
+ i
* This::shdr_size
;
1585 typename
This::Shdr
shdr(pshdr
);
1587 this->layout_eh_frame_section(layout
,
1600 delete[] gc_sd
->section_headers_data
;
1601 delete[] gc_sd
->section_names_data
;
1602 delete[] gc_sd
->symbols_data
;
1603 delete[] gc_sd
->symbol_names_data
;
1604 this->set_symbols_data(NULL
);
1608 delete sd
->section_headers
;
1609 sd
->section_headers
= NULL
;
1610 delete sd
->section_names
;
1611 sd
->section_names
= NULL
;
1615 // Layout sections whose layout was deferred while waiting for
1616 // input files from a plugin.
1618 template<int size
, bool big_endian
>
1620 Sized_relobj_file
<size
, big_endian
>::do_layout_deferred_sections(Layout
* layout
)
1622 typename
std::vector
<Deferred_layout
>::iterator deferred
;
1624 for (deferred
= this->deferred_layout_
.begin();
1625 deferred
!= this->deferred_layout_
.end();
1628 typename
This::Shdr
shdr(deferred
->shdr_data_
);
1629 // If the section is not included, it is because the garbage collector
1630 // decided it is not needed. Avoid reverting that decision.
1631 if (!this->is_section_included(deferred
->shndx_
))
1634 if (parameters
->options().relocatable()
1635 || deferred
->name_
!= ".eh_frame"
1636 || !this->check_eh_frame_flags(&shdr
))
1637 this->layout_section(layout
, deferred
->shndx_
, deferred
->name_
.c_str(),
1638 shdr
, deferred
->reloc_shndx_
,
1639 deferred
->reloc_type_
);
1642 // Reading the symbols again here may be slow.
1643 Read_symbols_data sd
;
1644 this->read_symbols(&sd
);
1645 this->layout_eh_frame_section(layout
,
1648 sd
.symbol_names
->data(),
1649 sd
.symbol_names_size
,
1652 deferred
->reloc_shndx_
,
1653 deferred
->reloc_type_
);
1657 this->deferred_layout_
.clear();
1659 // Now handle the deferred relocation sections.
1661 Output_sections
& out_sections(this->output_sections());
1662 std::vector
<Address
>& out_section_offsets(this->section_offsets());
1664 for (deferred
= this->deferred_layout_relocs_
.begin();
1665 deferred
!= this->deferred_layout_relocs_
.end();
1668 unsigned int shndx
= deferred
->shndx_
;
1669 typename
This::Shdr
shdr(deferred
->shdr_data_
);
1670 unsigned int data_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1672 Output_section
* data_section
= out_sections
[data_shndx
];
1673 if (data_section
== NULL
)
1675 out_sections
[shndx
] = NULL
;
1676 out_section_offsets
[shndx
] = invalid_address
;
1680 Relocatable_relocs
* rr
= new Relocatable_relocs();
1681 this->set_relocatable_relocs(shndx
, rr
);
1683 Output_section
* os
= layout
->layout_reloc(this, shndx
, shdr
,
1685 out_sections
[shndx
] = os
;
1686 out_section_offsets
[shndx
] = invalid_address
;
1690 // Add the symbols to the symbol table.
1692 template<int size
, bool big_endian
>
1694 Sized_relobj_file
<size
, big_endian
>::do_add_symbols(Symbol_table
* symtab
,
1695 Read_symbols_data
* sd
,
1698 if (sd
->symbols
== NULL
)
1700 gold_assert(sd
->symbol_names
== NULL
);
1704 const int sym_size
= This::sym_size
;
1705 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1707 if (symcount
* sym_size
!= sd
->symbols_size
- sd
->external_symbols_offset
)
1709 this->error(_("size of symbols is not multiple of symbol size"));
1713 this->symbols_
.resize(symcount
);
1715 const char* sym_names
=
1716 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1717 symtab
->add_from_relobj(this,
1718 sd
->symbols
->data() + sd
->external_symbols_offset
,
1719 symcount
, this->local_symbol_count_
,
1720 sym_names
, sd
->symbol_names_size
,
1722 &this->defined_count_
);
1726 delete sd
->symbol_names
;
1727 sd
->symbol_names
= NULL
;
1730 // Find out if this object, that is a member of a lib group, should be included
1731 // in the link. We check every symbol defined by this object. If the symbol
1732 // table has a strong undefined reference to that symbol, we have to include
1735 template<int size
, bool big_endian
>
1736 Archive::Should_include
1737 Sized_relobj_file
<size
, big_endian
>::do_should_include_member(
1738 Symbol_table
* symtab
,
1740 Read_symbols_data
* sd
,
1743 char* tmpbuf
= NULL
;
1744 size_t tmpbuflen
= 0;
1745 const char* sym_names
=
1746 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1747 const unsigned char* syms
=
1748 sd
->symbols
->data() + sd
->external_symbols_offset
;
1749 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1750 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1753 const unsigned char* p
= syms
;
1755 for (size_t i
= 0; i
< symcount
; ++i
, p
+= sym_size
)
1757 elfcpp::Sym
<size
, big_endian
> sym(p
);
1758 unsigned int st_shndx
= sym
.get_st_shndx();
1759 if (st_shndx
== elfcpp::SHN_UNDEF
)
1762 unsigned int st_name
= sym
.get_st_name();
1763 const char* name
= sym_names
+ st_name
;
1765 Archive::Should_include t
= Archive::should_include_member(symtab
,
1771 if (t
== Archive::SHOULD_INCLUDE_YES
)
1780 return Archive::SHOULD_INCLUDE_UNKNOWN
;
1783 // Iterate over global defined symbols, calling a visitor class V for each.
1785 template<int size
, bool big_endian
>
1787 Sized_relobj_file
<size
, big_endian
>::do_for_all_global_symbols(
1788 Read_symbols_data
* sd
,
1789 Library_base::Symbol_visitor_base
* v
)
1791 const char* sym_names
=
1792 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1793 const unsigned char* syms
=
1794 sd
->symbols
->data() + sd
->external_symbols_offset
;
1795 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1796 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1798 const unsigned char* p
= syms
;
1800 for (size_t i
= 0; i
< symcount
; ++i
, p
+= sym_size
)
1802 elfcpp::Sym
<size
, big_endian
> sym(p
);
1803 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
1804 v
->visit(sym_names
+ sym
.get_st_name());
1808 // Return whether the local symbol SYMNDX has a PLT offset.
1810 template<int size
, bool big_endian
>
1812 Sized_relobj_file
<size
, big_endian
>::local_has_plt_offset(
1813 unsigned int symndx
) const
1815 typename
Local_plt_offsets::const_iterator p
=
1816 this->local_plt_offsets_
.find(symndx
);
1817 return p
!= this->local_plt_offsets_
.end();
1820 // Get the PLT offset of a local symbol.
1822 template<int size
, bool big_endian
>
1824 Sized_relobj_file
<size
, big_endian
>::local_plt_offset(unsigned int symndx
) const
1826 typename
Local_plt_offsets::const_iterator p
=
1827 this->local_plt_offsets_
.find(symndx
);
1828 gold_assert(p
!= this->local_plt_offsets_
.end());
1832 // Set the PLT offset of a local symbol.
1834 template<int size
, bool big_endian
>
1836 Sized_relobj_file
<size
, big_endian
>::set_local_plt_offset(
1837 unsigned int symndx
, unsigned int plt_offset
)
1839 std::pair
<typename
Local_plt_offsets::iterator
, bool> ins
=
1840 this->local_plt_offsets_
.insert(std::make_pair(symndx
, plt_offset
));
1841 gold_assert(ins
.second
);
1844 // First pass over the local symbols. Here we add their names to
1845 // *POOL and *DYNPOOL, and we store the symbol value in
1846 // THIS->LOCAL_VALUES_. This function is always called from a
1847 // singleton thread. This is followed by a call to
1848 // finalize_local_symbols.
1850 template<int size
, bool big_endian
>
1852 Sized_relobj_file
<size
, big_endian
>::do_count_local_symbols(Stringpool
* pool
,
1853 Stringpool
* dynpool
)
1855 gold_assert(this->symtab_shndx_
!= -1U);
1856 if (this->symtab_shndx_
== 0)
1858 // This object has no symbols. Weird but legal.
1862 // Read the symbol table section header.
1863 const unsigned int symtab_shndx
= this->symtab_shndx_
;
1864 typename
This::Shdr
symtabshdr(this,
1865 this->elf_file_
.section_header(symtab_shndx
));
1866 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
1868 // Read the local symbols.
1869 const int sym_size
= This::sym_size
;
1870 const unsigned int loccount
= this->local_symbol_count_
;
1871 gold_assert(loccount
== symtabshdr
.get_sh_info());
1872 off_t locsize
= loccount
* sym_size
;
1873 const unsigned char* psyms
= this->get_view(symtabshdr
.get_sh_offset(),
1874 locsize
, true, true);
1876 // Read the symbol names.
1877 const unsigned int strtab_shndx
=
1878 this->adjust_shndx(symtabshdr
.get_sh_link());
1879 section_size_type strtab_size
;
1880 const unsigned char* pnamesu
= this->section_contents(strtab_shndx
,
1883 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
1885 // Loop over the local symbols.
1887 const Output_sections
& out_sections(this->output_sections());
1888 unsigned int shnum
= this->shnum();
1889 unsigned int count
= 0;
1890 unsigned int dyncount
= 0;
1891 // Skip the first, dummy, symbol.
1893 bool strip_all
= parameters
->options().strip_all();
1894 bool discard_all
= parameters
->options().discard_all();
1895 bool discard_locals
= parameters
->options().discard_locals();
1896 for (unsigned int i
= 1; i
< loccount
; ++i
, psyms
+= sym_size
)
1898 elfcpp::Sym
<size
, big_endian
> sym(psyms
);
1900 Symbol_value
<size
>& lv(this->local_values_
[i
]);
1903 unsigned int shndx
= this->adjust_sym_shndx(i
, sym
.get_st_shndx(),
1905 lv
.set_input_shndx(shndx
, is_ordinary
);
1907 if (sym
.get_st_type() == elfcpp::STT_SECTION
)
1908 lv
.set_is_section_symbol();
1909 else if (sym
.get_st_type() == elfcpp::STT_TLS
)
1910 lv
.set_is_tls_symbol();
1911 else if (sym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1912 lv
.set_is_ifunc_symbol();
1914 // Save the input symbol value for use in do_finalize_local_symbols().
1915 lv
.set_input_value(sym
.get_st_value());
1917 // Decide whether this symbol should go into the output file.
1919 if ((shndx
< shnum
&& out_sections
[shndx
] == NULL
)
1920 || shndx
== this->discarded_eh_frame_shndx_
)
1922 lv
.set_no_output_symtab_entry();
1923 gold_assert(!lv
.needs_output_dynsym_entry());
1927 if (sym
.get_st_type() == elfcpp::STT_SECTION
)
1929 lv
.set_no_output_symtab_entry();
1930 gold_assert(!lv
.needs_output_dynsym_entry());
1934 if (sym
.get_st_name() >= strtab_size
)
1936 this->error(_("local symbol %u section name out of range: %u >= %u"),
1937 i
, sym
.get_st_name(),
1938 static_cast<unsigned int>(strtab_size
));
1939 lv
.set_no_output_symtab_entry();
1943 const char* name
= pnames
+ sym
.get_st_name();
1945 // If needed, add the symbol to the dynamic symbol table string pool.
1946 if (lv
.needs_output_dynsym_entry())
1948 dynpool
->add(name
, true, NULL
);
1953 || (discard_all
&& lv
.may_be_discarded_from_output_symtab()))
1955 lv
.set_no_output_symtab_entry();
1959 // If --discard-locals option is used, discard all temporary local
1960 // symbols. These symbols start with system-specific local label
1961 // prefixes, typically .L for ELF system. We want to be compatible
1962 // with GNU ld so here we essentially use the same check in
1963 // bfd_is_local_label(). The code is different because we already
1966 // - the symbol is local and thus cannot have global or weak binding.
1967 // - the symbol is not a section symbol.
1968 // - the symbol has a name.
1970 // We do not discard a symbol if it needs a dynamic symbol entry.
1972 && sym
.get_st_type() != elfcpp::STT_FILE
1973 && !lv
.needs_output_dynsym_entry()
1974 && lv
.may_be_discarded_from_output_symtab()
1975 && parameters
->target().is_local_label_name(name
))
1977 lv
.set_no_output_symtab_entry();
1981 // Discard the local symbol if -retain_symbols_file is specified
1982 // and the local symbol is not in that file.
1983 if (!parameters
->options().should_retain_symbol(name
))
1985 lv
.set_no_output_symtab_entry();
1989 // Add the symbol to the symbol table string pool.
1990 pool
->add(name
, true, NULL
);
1994 this->output_local_symbol_count_
= count
;
1995 this->output_local_dynsym_count_
= dyncount
;
1998 // Compute the final value of a local symbol.
2000 template<int size
, bool big_endian
>
2001 typename Sized_relobj_file
<size
, big_endian
>::Compute_final_local_value_status
2002 Sized_relobj_file
<size
, big_endian
>::compute_final_local_value_internal(
2004 const Symbol_value
<size
>* lv_in
,
2005 Symbol_value
<size
>* lv_out
,
2007 const Output_sections
& out_sections
,
2008 const std::vector
<Address
>& out_offsets
,
2009 const Symbol_table
* symtab
)
2011 // We are going to overwrite *LV_OUT, if it has a merged symbol value,
2012 // we may have a memory leak.
2013 gold_assert(lv_out
->has_output_value());
2016 unsigned int shndx
= lv_in
->input_shndx(&is_ordinary
);
2018 // Set the output symbol value.
2022 if (shndx
== elfcpp::SHN_ABS
|| Symbol::is_common_shndx(shndx
))
2023 lv_out
->set_output_value(lv_in
->input_value());
2026 this->error(_("unknown section index %u for local symbol %u"),
2028 lv_out
->set_output_value(0);
2029 return This::CFLV_ERROR
;
2034 if (shndx
>= this->shnum())
2036 this->error(_("local symbol %u section index %u out of range"),
2038 lv_out
->set_output_value(0);
2039 return This::CFLV_ERROR
;
2042 Output_section
* os
= out_sections
[shndx
];
2043 Address secoffset
= out_offsets
[shndx
];
2044 if (symtab
->is_section_folded(this, shndx
))
2046 gold_assert(os
== NULL
&& secoffset
== invalid_address
);
2047 // Get the os of the section it is folded onto.
2048 Section_id folded
= symtab
->icf()->get_folded_section(this,
2050 gold_assert(folded
.first
!= NULL
);
2051 Sized_relobj_file
<size
, big_endian
>* folded_obj
= reinterpret_cast
2052 <Sized_relobj_file
<size
, big_endian
>*>(folded
.first
);
2053 os
= folded_obj
->output_section(folded
.second
);
2054 gold_assert(os
!= NULL
);
2055 secoffset
= folded_obj
->get_output_section_offset(folded
.second
);
2057 // This could be a relaxed input section.
2058 if (secoffset
== invalid_address
)
2060 const Output_relaxed_input_section
* relaxed_section
=
2061 os
->find_relaxed_input_section(folded_obj
, folded
.second
);
2062 gold_assert(relaxed_section
!= NULL
);
2063 secoffset
= relaxed_section
->address() - os
->address();
2069 // This local symbol belongs to a section we are discarding.
2070 // In some cases when applying relocations later, we will
2071 // attempt to match it to the corresponding kept section,
2072 // so we leave the input value unchanged here.
2073 return This::CFLV_DISCARDED
;
2075 else if (secoffset
== invalid_address
)
2079 // This is a SHF_MERGE section or one which otherwise
2080 // requires special handling.
2081 if (shndx
== this->discarded_eh_frame_shndx_
)
2083 // This local symbol belongs to a discarded .eh_frame
2084 // section. Just treat it like the case in which
2085 // os == NULL above.
2086 gold_assert(this->has_eh_frame_
);
2087 return This::CFLV_DISCARDED
;
2089 else if (!lv_in
->is_section_symbol())
2091 // This is not a section symbol. We can determine
2092 // the final value now.
2093 lv_out
->set_output_value(
2094 os
->output_address(this, shndx
, lv_in
->input_value()));
2096 else if (!os
->find_starting_output_address(this, shndx
, &start
))
2098 // This is a section symbol, but apparently not one in a
2099 // merged section. First check to see if this is a relaxed
2100 // input section. If so, use its address. Otherwise just
2101 // use the start of the output section. This happens with
2102 // relocatable links when the input object has section
2103 // symbols for arbitrary non-merge sections.
2104 const Output_section_data
* posd
=
2105 os
->find_relaxed_input_section(this, shndx
);
2108 Address relocatable_link_adjustment
=
2109 relocatable
? os
->address() : 0;
2110 lv_out
->set_output_value(posd
->address()
2111 - relocatable_link_adjustment
);
2114 lv_out
->set_output_value(os
->address());
2118 // We have to consider the addend to determine the
2119 // value to use in a relocation. START is the start
2120 // of this input section. If we are doing a relocatable
2121 // link, use offset from start output section instead of
2123 Address adjusted_start
=
2124 relocatable
? start
- os
->address() : start
;
2125 Merged_symbol_value
<size
>* msv
=
2126 new Merged_symbol_value
<size
>(lv_in
->input_value(),
2128 lv_out
->set_merged_symbol_value(msv
);
2131 else if (lv_in
->is_tls_symbol())
2132 lv_out
->set_output_value(os
->tls_offset()
2134 + lv_in
->input_value());
2136 lv_out
->set_output_value((relocatable
? 0 : os
->address())
2138 + lv_in
->input_value());
2140 return This::CFLV_OK
;
2143 // Compute final local symbol value. R_SYM is the index of a local
2144 // symbol in symbol table. LV points to a symbol value, which is
2145 // expected to hold the input value and to be over-written by the
2146 // final value. SYMTAB points to a symbol table. Some targets may want
2147 // to know would-be-finalized local symbol values in relaxation.
2148 // Hence we provide this method. Since this method updates *LV, a
2149 // callee should make a copy of the original local symbol value and
2150 // use the copy instead of modifying an object's local symbols before
2151 // everything is finalized. The caller should also free up any allocated
2152 // memory in the return value in *LV.
2153 template<int size
, bool big_endian
>
2154 typename Sized_relobj_file
<size
, big_endian
>::Compute_final_local_value_status
2155 Sized_relobj_file
<size
, big_endian
>::compute_final_local_value(
2157 const Symbol_value
<size
>* lv_in
,
2158 Symbol_value
<size
>* lv_out
,
2159 const Symbol_table
* symtab
)
2161 // This is just a wrapper of compute_final_local_value_internal.
2162 const bool relocatable
= parameters
->options().relocatable();
2163 const Output_sections
& out_sections(this->output_sections());
2164 const std::vector
<Address
>& out_offsets(this->section_offsets());
2165 return this->compute_final_local_value_internal(r_sym
, lv_in
, lv_out
,
2166 relocatable
, out_sections
,
2167 out_offsets
, symtab
);
2170 // Finalize the local symbols. Here we set the final value in
2171 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
2172 // This function is always called from a singleton thread. The actual
2173 // output of the local symbols will occur in a separate task.
2175 template<int size
, bool big_endian
>
2177 Sized_relobj_file
<size
, big_endian
>::do_finalize_local_symbols(
2180 Symbol_table
* symtab
)
2182 gold_assert(off
== static_cast<off_t
>(align_address(off
, size
>> 3)));
2184 const unsigned int loccount
= this->local_symbol_count_
;
2185 this->local_symbol_offset_
= off
;
2187 const bool relocatable
= parameters
->options().relocatable();
2188 const Output_sections
& out_sections(this->output_sections());
2189 const std::vector
<Address
>& out_offsets(this->section_offsets());
2191 for (unsigned int i
= 1; i
< loccount
; ++i
)
2193 Symbol_value
<size
>* lv
= &this->local_values_
[i
];
2195 Compute_final_local_value_status cflv_status
=
2196 this->compute_final_local_value_internal(i
, lv
, lv
, relocatable
,
2197 out_sections
, out_offsets
,
2199 switch (cflv_status
)
2202 if (!lv
->is_output_symtab_index_set())
2204 lv
->set_output_symtab_index(index
);
2208 case CFLV_DISCARDED
:
2219 // Set the output dynamic symbol table indexes for the local variables.
2221 template<int size
, bool big_endian
>
2223 Sized_relobj_file
<size
, big_endian
>::do_set_local_dynsym_indexes(
2226 const unsigned int loccount
= this->local_symbol_count_
;
2227 for (unsigned int i
= 1; i
< loccount
; ++i
)
2229 Symbol_value
<size
>& lv(this->local_values_
[i
]);
2230 if (lv
.needs_output_dynsym_entry())
2232 lv
.set_output_dynsym_index(index
);
2239 // Set the offset where local dynamic symbol information will be stored.
2240 // Returns the count of local symbols contributed to the symbol table by
2243 template<int size
, bool big_endian
>
2245 Sized_relobj_file
<size
, big_endian
>::do_set_local_dynsym_offset(off_t off
)
2247 gold_assert(off
== static_cast<off_t
>(align_address(off
, size
>> 3)));
2248 this->local_dynsym_offset_
= off
;
2249 return this->output_local_dynsym_count_
;
2252 // If Symbols_data is not NULL get the section flags from here otherwise
2253 // get it from the file.
2255 template<int size
, bool big_endian
>
2257 Sized_relobj_file
<size
, big_endian
>::do_section_flags(unsigned int shndx
)
2259 Symbols_data
* sd
= this->get_symbols_data();
2262 const unsigned char* pshdrs
= sd
->section_headers_data
2263 + This::shdr_size
* shndx
;
2264 typename
This::Shdr
shdr(pshdrs
);
2265 return shdr
.get_sh_flags();
2267 // If sd is NULL, read the section header from the file.
2268 return this->elf_file_
.section_flags(shndx
);
2271 // Get the section's ent size from Symbols_data. Called by get_section_contents
2274 template<int size
, bool big_endian
>
2276 Sized_relobj_file
<size
, big_endian
>::do_section_entsize(unsigned int shndx
)
2278 Symbols_data
* sd
= this->get_symbols_data();
2279 gold_assert(sd
!= NULL
);
2281 const unsigned char* pshdrs
= sd
->section_headers_data
2282 + This::shdr_size
* shndx
;
2283 typename
This::Shdr
shdr(pshdrs
);
2284 return shdr
.get_sh_entsize();
2287 // Write out the local symbols.
2289 template<int size
, bool big_endian
>
2291 Sized_relobj_file
<size
, big_endian
>::write_local_symbols(
2293 const Stringpool
* sympool
,
2294 const Stringpool
* dynpool
,
2295 Output_symtab_xindex
* symtab_xindex
,
2296 Output_symtab_xindex
* dynsym_xindex
,
2299 const bool strip_all
= parameters
->options().strip_all();
2302 if (this->output_local_dynsym_count_
== 0)
2304 this->output_local_symbol_count_
= 0;
2307 gold_assert(this->symtab_shndx_
!= -1U);
2308 if (this->symtab_shndx_
== 0)
2310 // This object has no symbols. Weird but legal.
2314 // Read the symbol table section header.
2315 const unsigned int symtab_shndx
= this->symtab_shndx_
;
2316 typename
This::Shdr
symtabshdr(this,
2317 this->elf_file_
.section_header(symtab_shndx
));
2318 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
2319 const unsigned int loccount
= this->local_symbol_count_
;
2320 gold_assert(loccount
== symtabshdr
.get_sh_info());
2322 // Read the local symbols.
2323 const int sym_size
= This::sym_size
;
2324 off_t locsize
= loccount
* sym_size
;
2325 const unsigned char* psyms
= this->get_view(symtabshdr
.get_sh_offset(),
2326 locsize
, true, false);
2328 // Read the symbol names.
2329 const unsigned int strtab_shndx
=
2330 this->adjust_shndx(symtabshdr
.get_sh_link());
2331 section_size_type strtab_size
;
2332 const unsigned char* pnamesu
= this->section_contents(strtab_shndx
,
2335 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
2337 // Get views into the output file for the portions of the symbol table
2338 // and the dynamic symbol table that we will be writing.
2339 off_t output_size
= this->output_local_symbol_count_
* sym_size
;
2340 unsigned char* oview
= NULL
;
2341 if (output_size
> 0)
2342 oview
= of
->get_output_view(symtab_off
+ this->local_symbol_offset_
,
2345 off_t dyn_output_size
= this->output_local_dynsym_count_
* sym_size
;
2346 unsigned char* dyn_oview
= NULL
;
2347 if (dyn_output_size
> 0)
2348 dyn_oview
= of
->get_output_view(this->local_dynsym_offset_
,
2351 const Output_sections
out_sections(this->output_sections());
2353 gold_assert(this->local_values_
.size() == loccount
);
2355 unsigned char* ov
= oview
;
2356 unsigned char* dyn_ov
= dyn_oview
;
2358 for (unsigned int i
= 1; i
< loccount
; ++i
, psyms
+= sym_size
)
2360 elfcpp::Sym
<size
, big_endian
> isym(psyms
);
2362 Symbol_value
<size
>& lv(this->local_values_
[i
]);
2365 unsigned int st_shndx
= this->adjust_sym_shndx(i
, isym
.get_st_shndx(),
2369 gold_assert(st_shndx
< out_sections
.size());
2370 if (out_sections
[st_shndx
] == NULL
)
2372 st_shndx
= out_sections
[st_shndx
]->out_shndx();
2373 if (st_shndx
>= elfcpp::SHN_LORESERVE
)
2375 if (lv
.has_output_symtab_entry())
2376 symtab_xindex
->add(lv
.output_symtab_index(), st_shndx
);
2377 if (lv
.has_output_dynsym_entry())
2378 dynsym_xindex
->add(lv
.output_dynsym_index(), st_shndx
);
2379 st_shndx
= elfcpp::SHN_XINDEX
;
2383 // Write the symbol to the output symbol table.
2384 if (lv
.has_output_symtab_entry())
2386 elfcpp::Sym_write
<size
, big_endian
> osym(ov
);
2388 gold_assert(isym
.get_st_name() < strtab_size
);
2389 const char* name
= pnames
+ isym
.get_st_name();
2390 osym
.put_st_name(sympool
->get_offset(name
));
2391 osym
.put_st_value(this->local_values_
[i
].value(this, 0));
2392 osym
.put_st_size(isym
.get_st_size());
2393 osym
.put_st_info(isym
.get_st_info());
2394 osym
.put_st_other(isym
.get_st_other());
2395 osym
.put_st_shndx(st_shndx
);
2400 // Write the symbol to the output dynamic symbol table.
2401 if (lv
.has_output_dynsym_entry())
2403 gold_assert(dyn_ov
< dyn_oview
+ dyn_output_size
);
2404 elfcpp::Sym_write
<size
, big_endian
> osym(dyn_ov
);
2406 gold_assert(isym
.get_st_name() < strtab_size
);
2407 const char* name
= pnames
+ isym
.get_st_name();
2408 osym
.put_st_name(dynpool
->get_offset(name
));
2409 osym
.put_st_value(this->local_values_
[i
].value(this, 0));
2410 osym
.put_st_size(isym
.get_st_size());
2411 osym
.put_st_info(isym
.get_st_info());
2412 osym
.put_st_other(isym
.get_st_other());
2413 osym
.put_st_shndx(st_shndx
);
2420 if (output_size
> 0)
2422 gold_assert(ov
- oview
== output_size
);
2423 of
->write_output_view(symtab_off
+ this->local_symbol_offset_
,
2424 output_size
, oview
);
2427 if (dyn_output_size
> 0)
2429 gold_assert(dyn_ov
- dyn_oview
== dyn_output_size
);
2430 of
->write_output_view(this->local_dynsym_offset_
, dyn_output_size
,
2435 // Set *INFO to symbolic information about the offset OFFSET in the
2436 // section SHNDX. Return true if we found something, false if we
2439 template<int size
, bool big_endian
>
2441 Sized_relobj_file
<size
, big_endian
>::get_symbol_location_info(
2444 Symbol_location_info
* info
)
2446 if (this->symtab_shndx_
== 0)
2449 section_size_type symbols_size
;
2450 const unsigned char* symbols
= this->section_contents(this->symtab_shndx_
,
2454 unsigned int symbol_names_shndx
=
2455 this->adjust_shndx(this->section_link(this->symtab_shndx_
));
2456 section_size_type names_size
;
2457 const unsigned char* symbol_names_u
=
2458 this->section_contents(symbol_names_shndx
, &names_size
, false);
2459 const char* symbol_names
= reinterpret_cast<const char*>(symbol_names_u
);
2461 const int sym_size
= This::sym_size
;
2462 const size_t count
= symbols_size
/ sym_size
;
2464 const unsigned char* p
= symbols
;
2465 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
2467 elfcpp::Sym
<size
, big_endian
> sym(p
);
2469 if (sym
.get_st_type() == elfcpp::STT_FILE
)
2471 if (sym
.get_st_name() >= names_size
)
2472 info
->source_file
= "(invalid)";
2474 info
->source_file
= symbol_names
+ sym
.get_st_name();
2479 unsigned int st_shndx
= this->adjust_sym_shndx(i
, sym
.get_st_shndx(),
2482 && st_shndx
== shndx
2483 && static_cast<off_t
>(sym
.get_st_value()) <= offset
2484 && (static_cast<off_t
>(sym
.get_st_value() + sym
.get_st_size())
2487 if (sym
.get_st_name() > names_size
)
2488 info
->enclosing_symbol_name
= "(invalid)";
2491 info
->enclosing_symbol_name
= symbol_names
+ sym
.get_st_name();
2492 if (parameters
->options().do_demangle())
2494 char* demangled_name
= cplus_demangle(
2495 info
->enclosing_symbol_name
.c_str(),
2496 DMGL_ANSI
| DMGL_PARAMS
);
2497 if (demangled_name
!= NULL
)
2499 info
->enclosing_symbol_name
.assign(demangled_name
);
2500 free(demangled_name
);
2511 // Look for a kept section corresponding to the given discarded section,
2512 // and return its output address. This is used only for relocations in
2513 // debugging sections. If we can't find the kept section, return 0.
2515 template<int size
, bool big_endian
>
2516 typename Sized_relobj_file
<size
, big_endian
>::Address
2517 Sized_relobj_file
<size
, big_endian
>::map_to_kept_section(
2521 Relobj
* kept_object
;
2522 unsigned int kept_shndx
;
2523 if (this->get_kept_comdat_section(shndx
, &kept_object
, &kept_shndx
))
2525 Sized_relobj_file
<size
, big_endian
>* kept_relobj
=
2526 static_cast<Sized_relobj_file
<size
, big_endian
>*>(kept_object
);
2527 Output_section
* os
= kept_relobj
->output_section(kept_shndx
);
2528 Address offset
= kept_relobj
->get_output_section_offset(kept_shndx
);
2529 if (os
!= NULL
&& offset
!= invalid_address
)
2532 return os
->address() + offset
;
2539 // Get symbol counts.
2541 template<int size
, bool big_endian
>
2543 Sized_relobj_file
<size
, big_endian
>::do_get_global_symbol_counts(
2544 const Symbol_table
*,
2548 *defined
= this->defined_count_
;
2550 for (typename
Symbols::const_iterator p
= this->symbols_
.begin();
2551 p
!= this->symbols_
.end();
2554 && (*p
)->source() == Symbol::FROM_OBJECT
2555 && (*p
)->object() == this
2556 && (*p
)->is_defined())
2561 // Input_objects methods.
2563 // Add a regular relocatable object to the list. Return false if this
2564 // object should be ignored.
2567 Input_objects::add_object(Object
* obj
)
2569 // Print the filename if the -t/--trace option is selected.
2570 if (parameters
->options().trace())
2571 gold_info("%s", obj
->name().c_str());
2573 if (!obj
->is_dynamic())
2574 this->relobj_list_
.push_back(static_cast<Relobj
*>(obj
));
2577 // See if this is a duplicate SONAME.
2578 Dynobj
* dynobj
= static_cast<Dynobj
*>(obj
);
2579 const char* soname
= dynobj
->soname();
2581 std::pair
<Unordered_set
<std::string
>::iterator
, bool> ins
=
2582 this->sonames_
.insert(soname
);
2585 // We have already seen a dynamic object with this soname.
2589 this->dynobj_list_
.push_back(dynobj
);
2592 // Add this object to the cross-referencer if requested.
2593 if (parameters
->options().user_set_print_symbol_counts()
2594 || parameters
->options().cref())
2596 if (this->cref_
== NULL
)
2597 this->cref_
= new Cref();
2598 this->cref_
->add_object(obj
);
2604 // For each dynamic object, record whether we've seen all of its
2605 // explicit dependencies.
2608 Input_objects::check_dynamic_dependencies() const
2610 bool issued_copy_dt_needed_error
= false;
2611 for (Dynobj_list::const_iterator p
= this->dynobj_list_
.begin();
2612 p
!= this->dynobj_list_
.end();
2615 const Dynobj::Needed
& needed((*p
)->needed());
2616 bool found_all
= true;
2617 Dynobj::Needed::const_iterator pneeded
;
2618 for (pneeded
= needed
.begin(); pneeded
!= needed
.end(); ++pneeded
)
2620 if (this->sonames_
.find(*pneeded
) == this->sonames_
.end())
2626 (*p
)->set_has_unknown_needed_entries(!found_all
);
2628 // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2629 // that gold does not support. However, they cause no trouble
2630 // unless there is a DT_NEEDED entry that we don't know about;
2631 // warn only in that case.
2633 && !issued_copy_dt_needed_error
2634 && (parameters
->options().copy_dt_needed_entries()
2635 || parameters
->options().add_needed()))
2637 const char* optname
;
2638 if (parameters
->options().copy_dt_needed_entries())
2639 optname
= "--copy-dt-needed-entries";
2641 optname
= "--add-needed";
2642 gold_error(_("%s is not supported but is required for %s in %s"),
2643 optname
, (*pneeded
).c_str(), (*p
)->name().c_str());
2644 issued_copy_dt_needed_error
= true;
2649 // Start processing an archive.
2652 Input_objects::archive_start(Archive
* archive
)
2654 if (parameters
->options().user_set_print_symbol_counts()
2655 || parameters
->options().cref())
2657 if (this->cref_
== NULL
)
2658 this->cref_
= new Cref();
2659 this->cref_
->add_archive_start(archive
);
2663 // Stop processing an archive.
2666 Input_objects::archive_stop(Archive
* archive
)
2668 if (parameters
->options().user_set_print_symbol_counts()
2669 || parameters
->options().cref())
2670 this->cref_
->add_archive_stop(archive
);
2673 // Print symbol counts
2676 Input_objects::print_symbol_counts(const Symbol_table
* symtab
) const
2678 if (parameters
->options().user_set_print_symbol_counts()
2679 && this->cref_
!= NULL
)
2680 this->cref_
->print_symbol_counts(symtab
);
2683 // Print a cross reference table.
2686 Input_objects::print_cref(const Symbol_table
* symtab
, FILE* f
) const
2688 if (parameters
->options().cref() && this->cref_
!= NULL
)
2689 this->cref_
->print_cref(symtab
, f
);
2692 // Relocate_info methods.
2694 // Return a string describing the location of a relocation when file
2695 // and lineno information is not available. This is only used in
2698 template<int size
, bool big_endian
>
2700 Relocate_info
<size
, big_endian
>::location(size_t, off_t offset
) const
2702 Sized_dwarf_line_info
<size
, big_endian
> line_info(this->object
);
2703 std::string ret
= line_info
.addr2line(this->data_shndx
, offset
, NULL
);
2707 ret
= this->object
->name();
2709 Symbol_location_info info
;
2710 if (this->object
->get_symbol_location_info(this->data_shndx
, offset
, &info
))
2712 if (!info
.source_file
.empty())
2715 ret
+= info
.source_file
;
2717 size_t len
= info
.enclosing_symbol_name
.length() + 100;
2718 char* buf
= new char[len
];
2719 snprintf(buf
, len
, _(":function %s"),
2720 info
.enclosing_symbol_name
.c_str());
2727 ret
+= this->object
->section_name(this->data_shndx
);
2729 snprintf(buf
, sizeof buf
, "+0x%lx)", static_cast<long>(offset
));
2734 } // End namespace gold.
2739 using namespace gold
;
2741 // Read an ELF file with the header and return the appropriate
2742 // instance of Object.
2744 template<int size
, bool big_endian
>
2746 make_elf_sized_object(const std::string
& name
, Input_file
* input_file
,
2747 off_t offset
, const elfcpp::Ehdr
<size
, big_endian
>& ehdr
,
2748 bool* punconfigured
)
2750 Target
* target
= select_target(ehdr
.get_e_machine(), size
, big_endian
,
2751 ehdr
.get_e_ident()[elfcpp::EI_OSABI
],
2752 ehdr
.get_e_ident()[elfcpp::EI_ABIVERSION
]);
2754 gold_fatal(_("%s: unsupported ELF machine number %d"),
2755 name
.c_str(), ehdr
.get_e_machine());
2757 if (!parameters
->target_valid())
2758 set_parameters_target(target
);
2759 else if (target
!= ¶meters
->target())
2761 if (punconfigured
!= NULL
)
2762 *punconfigured
= true;
2764 gold_error(_("%s: incompatible target"), name
.c_str());
2768 return target
->make_elf_object
<size
, big_endian
>(name
, input_file
, offset
,
2772 } // End anonymous namespace.
2777 // Return whether INPUT_FILE is an ELF object.
2780 is_elf_object(Input_file
* input_file
, off_t offset
,
2781 const unsigned char** start
, int* read_size
)
2783 off_t filesize
= input_file
->file().filesize();
2784 int want
= elfcpp::Elf_recognizer::max_header_size
;
2785 if (filesize
- offset
< want
)
2786 want
= filesize
- offset
;
2788 const unsigned char* p
= input_file
->file().get_view(offset
, 0, want
,
2793 return elfcpp::Elf_recognizer::is_elf_file(p
, want
);
2796 // Read an ELF file and return the appropriate instance of Object.
2799 make_elf_object(const std::string
& name
, Input_file
* input_file
, off_t offset
,
2800 const unsigned char* p
, section_offset_type bytes
,
2801 bool* punconfigured
)
2803 if (punconfigured
!= NULL
)
2804 *punconfigured
= false;
2807 bool big_endian
= false;
2809 if (!elfcpp::Elf_recognizer::is_valid_header(p
, bytes
, &size
,
2810 &big_endian
, &error
))
2812 gold_error(_("%s: %s"), name
.c_str(), error
.c_str());
2820 #ifdef HAVE_TARGET_32_BIG
2821 elfcpp::Ehdr
<32, true> ehdr(p
);
2822 return make_elf_sized_object
<32, true>(name
, input_file
,
2823 offset
, ehdr
, punconfigured
);
2825 if (punconfigured
!= NULL
)
2826 *punconfigured
= true;
2828 gold_error(_("%s: not configured to support "
2829 "32-bit big-endian object"),
2836 #ifdef HAVE_TARGET_32_LITTLE
2837 elfcpp::Ehdr
<32, false> ehdr(p
);
2838 return make_elf_sized_object
<32, false>(name
, input_file
,
2839 offset
, ehdr
, punconfigured
);
2841 if (punconfigured
!= NULL
)
2842 *punconfigured
= true;
2844 gold_error(_("%s: not configured to support "
2845 "32-bit little-endian object"),
2851 else if (size
== 64)
2855 #ifdef HAVE_TARGET_64_BIG
2856 elfcpp::Ehdr
<64, true> ehdr(p
);
2857 return make_elf_sized_object
<64, true>(name
, input_file
,
2858 offset
, ehdr
, punconfigured
);
2860 if (punconfigured
!= NULL
)
2861 *punconfigured
= true;
2863 gold_error(_("%s: not configured to support "
2864 "64-bit big-endian object"),
2871 #ifdef HAVE_TARGET_64_LITTLE
2872 elfcpp::Ehdr
<64, false> ehdr(p
);
2873 return make_elf_sized_object
<64, false>(name
, input_file
,
2874 offset
, ehdr
, punconfigured
);
2876 if (punconfigured
!= NULL
)
2877 *punconfigured
= true;
2879 gold_error(_("%s: not configured to support "
2880 "64-bit little-endian object"),
2890 // Instantiate the templates we need.
2892 #ifdef HAVE_TARGET_32_LITTLE
2895 Object::read_section_data
<32, false>(elfcpp::Elf_file
<32, false, Object
>*,
2896 Read_symbols_data
*);
2899 #ifdef HAVE_TARGET_32_BIG
2902 Object::read_section_data
<32, true>(elfcpp::Elf_file
<32, true, Object
>*,
2903 Read_symbols_data
*);
2906 #ifdef HAVE_TARGET_64_LITTLE
2909 Object::read_section_data
<64, false>(elfcpp::Elf_file
<64, false, Object
>*,
2910 Read_symbols_data
*);
2913 #ifdef HAVE_TARGET_64_BIG
2916 Object::read_section_data
<64, true>(elfcpp::Elf_file
<64, true, Object
>*,
2917 Read_symbols_data
*);
2920 #ifdef HAVE_TARGET_32_LITTLE
2922 class Sized_relobj_file
<32, false>;
2925 #ifdef HAVE_TARGET_32_BIG
2927 class Sized_relobj_file
<32, true>;
2930 #ifdef HAVE_TARGET_64_LITTLE
2932 class Sized_relobj_file
<64, false>;
2935 #ifdef HAVE_TARGET_64_BIG
2937 class Sized_relobj_file
<64, true>;
2940 #ifdef HAVE_TARGET_32_LITTLE
2942 struct Relocate_info
<32, false>;
2945 #ifdef HAVE_TARGET_32_BIG
2947 struct Relocate_info
<32, true>;
2950 #ifdef HAVE_TARGET_64_LITTLE
2952 struct Relocate_info
<64, false>;
2955 #ifdef HAVE_TARGET_64_BIG
2957 struct Relocate_info
<64, true>;
2960 #ifdef HAVE_TARGET_32_LITTLE
2963 Xindex::initialize_symtab_xindex
<32, false>(Object
*, unsigned int);
2967 Xindex::read_symtab_xindex
<32, false>(Object
*, unsigned int,
2968 const unsigned char*);
2971 #ifdef HAVE_TARGET_32_BIG
2974 Xindex::initialize_symtab_xindex
<32, true>(Object
*, unsigned int);
2978 Xindex::read_symtab_xindex
<32, true>(Object
*, unsigned int,
2979 const unsigned char*);
2982 #ifdef HAVE_TARGET_64_LITTLE
2985 Xindex::initialize_symtab_xindex
<64, false>(Object
*, unsigned int);
2989 Xindex::read_symtab_xindex
<64, false>(Object
*, unsigned int,
2990 const unsigned char*);
2993 #ifdef HAVE_TARGET_64_BIG
2996 Xindex::initialize_symtab_xindex
<64, true>(Object
*, unsigned int);
3000 Xindex::read_symtab_xindex
<64, true>(Object
*, unsigned int,
3001 const unsigned char*);
3004 } // End namespace gold.