1 // object.cc -- support for an object file for linking in gold
3 // Copyright 2006, 2007, 2008, 2009, 2010 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
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. Returns the next
353 // available relocation index.
356 Relobj::finalize_incremental_relocs(Layout
* layout
)
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
];
369 this->reloc_counts_
[i
] = 0;
371 layout
->incremental_inputs()->set_reloc_count(rindex
);
374 // Class Sized_relobj.
376 template<int size
, bool big_endian
>
377 Sized_relobj
<size
, big_endian
>::Sized_relobj(
378 const std::string
& name
,
379 Input_file
* input_file
,
381 const elfcpp::Ehdr
<size
, big_endian
>& ehdr
)
382 : Relobj(name
, input_file
, offset
),
383 elf_file_(this, ehdr
),
385 local_symbol_count_(0),
386 output_local_symbol_count_(0),
387 output_local_dynsym_count_(0),
390 local_symbol_offset_(0),
391 local_dynsym_offset_(0),
393 local_got_offsets_(),
394 local_plt_offsets_(),
395 kept_comdat_sections_(),
396 has_eh_frame_(false),
397 discarded_eh_frame_shndx_(-1U),
399 deferred_layout_relocs_(),
400 compressed_sections_()
404 template<int size
, bool big_endian
>
405 Sized_relobj
<size
, big_endian
>::~Sized_relobj()
409 // Set up an object file based on the file header. This sets up the
410 // section information.
412 template<int size
, bool big_endian
>
414 Sized_relobj
<size
, big_endian
>::do_setup()
416 const unsigned int shnum
= this->elf_file_
.shnum();
417 this->set_shnum(shnum
);
420 // Find the SHT_SYMTAB section, given the section headers. The ELF
421 // standard says that maybe in the future there can be more than one
422 // SHT_SYMTAB section. Until somebody figures out how that could
423 // work, we assume there is only one.
425 template<int size
, bool big_endian
>
427 Sized_relobj
<size
, big_endian
>::find_symtab(const unsigned char* pshdrs
)
429 const unsigned int shnum
= this->shnum();
430 this->symtab_shndx_
= 0;
433 // Look through the sections in reverse order, since gas tends
434 // to put the symbol table at the end.
435 const unsigned char* p
= pshdrs
+ shnum
* This::shdr_size
;
436 unsigned int i
= shnum
;
437 unsigned int xindex_shndx
= 0;
438 unsigned int xindex_link
= 0;
442 p
-= This::shdr_size
;
443 typename
This::Shdr
shdr(p
);
444 if (shdr
.get_sh_type() == elfcpp::SHT_SYMTAB
)
446 this->symtab_shndx_
= i
;
447 if (xindex_shndx
> 0 && xindex_link
== i
)
450 new Xindex(this->elf_file_
.large_shndx_offset());
451 xindex
->read_symtab_xindex
<size
, big_endian
>(this,
454 this->set_xindex(xindex
);
459 // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
460 // one. This will work if it follows the SHT_SYMTAB
462 if (shdr
.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX
)
465 xindex_link
= this->adjust_shndx(shdr
.get_sh_link());
471 // Return the Xindex structure to use for object with lots of
474 template<int size
, bool big_endian
>
476 Sized_relobj
<size
, big_endian
>::do_initialize_xindex()
478 gold_assert(this->symtab_shndx_
!= -1U);
479 Xindex
* xindex
= new Xindex(this->elf_file_
.large_shndx_offset());
480 xindex
->initialize_symtab_xindex
<size
, big_endian
>(this, this->symtab_shndx_
);
484 // Return whether SHDR has the right type and flags to be a GNU
485 // .eh_frame section.
487 template<int size
, bool big_endian
>
489 Sized_relobj
<size
, big_endian
>::check_eh_frame_flags(
490 const elfcpp::Shdr
<size
, big_endian
>* shdr
) const
492 return (shdr
->get_sh_type() == elfcpp::SHT_PROGBITS
493 && (shdr
->get_sh_flags() & elfcpp::SHF_ALLOC
) != 0);
496 // Return whether there is a GNU .eh_frame section, given the section
497 // headers and the section names.
499 template<int size
, bool big_endian
>
501 Sized_relobj
<size
, big_endian
>::find_eh_frame(
502 const unsigned char* pshdrs
,
504 section_size_type names_size
) const
506 const unsigned int shnum
= this->shnum();
507 const unsigned char* p
= pshdrs
+ This::shdr_size
;
508 for (unsigned int i
= 1; i
< shnum
; ++i
, p
+= This::shdr_size
)
510 typename
This::Shdr
shdr(p
);
511 if (this->check_eh_frame_flags(&shdr
))
513 if (shdr
.get_sh_name() >= names_size
)
515 this->error(_("bad section name offset for section %u: %lu"),
516 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
520 const char* name
= names
+ shdr
.get_sh_name();
521 if (strcmp(name
, ".eh_frame") == 0)
528 // Build a table for any compressed debug sections, mapping each section index
529 // to the uncompressed size.
531 template<int size
, bool big_endian
>
532 Compressed_section_map
*
533 build_compressed_section_map(
534 const unsigned char* pshdrs
,
537 section_size_type names_size
,
538 Sized_relobj
<size
, big_endian
>* obj
)
540 Compressed_section_map
* uncompressed_sizes
= new Compressed_section_map();
541 const unsigned int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
542 const unsigned char* p
= pshdrs
+ shdr_size
;
543 for (unsigned int i
= 1; i
< shnum
; ++i
, p
+= shdr_size
)
545 typename
elfcpp::Shdr
<size
, big_endian
> shdr(p
);
546 if (shdr
.get_sh_type() == elfcpp::SHT_PROGBITS
547 && (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) == 0)
549 if (shdr
.get_sh_name() >= names_size
)
551 obj
->error(_("bad section name offset for section %u: %lu"),
552 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
556 const char* name
= names
+ shdr
.get_sh_name();
557 if (is_compressed_debug_section(name
))
559 section_size_type len
;
560 const unsigned char* contents
=
561 obj
->section_contents(i
, &len
, false);
562 uint64_t uncompressed_size
= get_uncompressed_size(contents
, len
);
563 if (uncompressed_size
!= -1ULL)
564 (*uncompressed_sizes
)[i
] =
565 convert_to_section_size_type(uncompressed_size
);
569 return uncompressed_sizes
;
572 // Read the sections and symbols from an object file.
574 template<int size
, bool big_endian
>
576 Sized_relobj
<size
, big_endian
>::do_read_symbols(Read_symbols_data
* sd
)
578 this->read_section_data(&this->elf_file_
, sd
);
580 const unsigned char* const pshdrs
= sd
->section_headers
->data();
582 this->find_symtab(pshdrs
);
584 const unsigned char* namesu
= sd
->section_names
->data();
585 const char* names
= reinterpret_cast<const char*>(namesu
);
586 if (memmem(names
, sd
->section_names_size
, ".eh_frame", 10) != NULL
)
588 if (this->find_eh_frame(pshdrs
, names
, sd
->section_names_size
))
589 this->has_eh_frame_
= true;
591 if (memmem(names
, sd
->section_names_size
, ".zdebug_", 8) != NULL
)
592 this->compressed_sections_
=
593 build_compressed_section_map(pshdrs
, this->shnum(), names
,
594 sd
->section_names_size
, this);
597 sd
->symbols_size
= 0;
598 sd
->external_symbols_offset
= 0;
599 sd
->symbol_names
= NULL
;
600 sd
->symbol_names_size
= 0;
602 if (this->symtab_shndx_
== 0)
604 // No symbol table. Weird but legal.
608 // Get the symbol table section header.
609 typename
This::Shdr
symtabshdr(pshdrs
610 + this->symtab_shndx_
* This::shdr_size
);
611 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
613 // If this object has a .eh_frame section, we need all the symbols.
614 // Otherwise we only need the external symbols. While it would be
615 // simpler to just always read all the symbols, I've seen object
616 // files with well over 2000 local symbols, which for a 64-bit
617 // object file format is over 5 pages that we don't need to read
620 const int sym_size
= This::sym_size
;
621 const unsigned int loccount
= symtabshdr
.get_sh_info();
622 this->local_symbol_count_
= loccount
;
623 this->local_values_
.resize(loccount
);
624 section_offset_type locsize
= loccount
* sym_size
;
625 off_t dataoff
= symtabshdr
.get_sh_offset();
626 section_size_type datasize
=
627 convert_to_section_size_type(symtabshdr
.get_sh_size());
628 off_t extoff
= dataoff
+ locsize
;
629 section_size_type extsize
= datasize
- locsize
;
631 off_t readoff
= this->has_eh_frame_
? dataoff
: extoff
;
632 section_size_type readsize
= this->has_eh_frame_
? datasize
: extsize
;
636 // No external symbols. Also weird but also legal.
640 File_view
* fvsymtab
= this->get_lasting_view(readoff
, readsize
, true, false);
642 // Read the section header for the symbol names.
643 unsigned int strtab_shndx
= this->adjust_shndx(symtabshdr
.get_sh_link());
644 if (strtab_shndx
>= this->shnum())
646 this->error(_("invalid symbol table name index: %u"), strtab_shndx
);
649 typename
This::Shdr
strtabshdr(pshdrs
+ strtab_shndx
* This::shdr_size
);
650 if (strtabshdr
.get_sh_type() != elfcpp::SHT_STRTAB
)
652 this->error(_("symbol table name section has wrong type: %u"),
653 static_cast<unsigned int>(strtabshdr
.get_sh_type()));
657 // Read the symbol names.
658 File_view
* fvstrtab
= this->get_lasting_view(strtabshdr
.get_sh_offset(),
659 strtabshdr
.get_sh_size(),
662 sd
->symbols
= fvsymtab
;
663 sd
->symbols_size
= readsize
;
664 sd
->external_symbols_offset
= this->has_eh_frame_
? locsize
: 0;
665 sd
->symbol_names
= fvstrtab
;
666 sd
->symbol_names_size
=
667 convert_to_section_size_type(strtabshdr
.get_sh_size());
670 // Return the section index of symbol SYM. Set *VALUE to its value in
671 // the object file. Set *IS_ORDINARY if this is an ordinary section
672 // index, not a special code between SHN_LORESERVE and SHN_HIRESERVE.
673 // Note that for a symbol which is not defined in this object file,
674 // this will set *VALUE to 0 and return SHN_UNDEF; it will not return
675 // the final value of the symbol in the link.
677 template<int size
, bool big_endian
>
679 Sized_relobj
<size
, big_endian
>::symbol_section_and_value(unsigned int sym
,
683 section_size_type symbols_size
;
684 const unsigned char* symbols
= this->section_contents(this->symtab_shndx_
,
688 const size_t count
= symbols_size
/ This::sym_size
;
689 gold_assert(sym
< count
);
691 elfcpp::Sym
<size
, big_endian
> elfsym(symbols
+ sym
* This::sym_size
);
692 *value
= elfsym
.get_st_value();
694 return this->adjust_sym_shndx(sym
, elfsym
.get_st_shndx(), is_ordinary
);
697 // Return whether to include a section group in the link. LAYOUT is
698 // used to keep track of which section groups we have already seen.
699 // INDEX is the index of the section group and SHDR is the section
700 // header. If we do not want to include this group, we set bits in
701 // OMIT for each section which should be discarded.
703 template<int size
, bool big_endian
>
705 Sized_relobj
<size
, big_endian
>::include_section_group(
706 Symbol_table
* symtab
,
710 const unsigned char* shdrs
,
711 const char* section_names
,
712 section_size_type section_names_size
,
713 std::vector
<bool>* omit
)
715 // Read the section contents.
716 typename
This::Shdr
shdr(shdrs
+ index
* This::shdr_size
);
717 const unsigned char* pcon
= this->get_view(shdr
.get_sh_offset(),
718 shdr
.get_sh_size(), true, false);
719 const elfcpp::Elf_Word
* pword
=
720 reinterpret_cast<const elfcpp::Elf_Word
*>(pcon
);
722 // The first word contains flags. We only care about COMDAT section
723 // groups. Other section groups are always included in the link
724 // just like ordinary sections.
725 elfcpp::Elf_Word flags
= elfcpp::Swap
<32, big_endian
>::readval(pword
);
727 // Look up the group signature, which is the name of a symbol. This
728 // is a lot of effort to go to to read a string. Why didn't they
729 // just have the group signature point into the string table, rather
730 // than indirect through a symbol?
732 // Get the appropriate symbol table header (this will normally be
733 // the single SHT_SYMTAB section, but in principle it need not be).
734 const unsigned int link
= this->adjust_shndx(shdr
.get_sh_link());
735 typename
This::Shdr
symshdr(this, this->elf_file_
.section_header(link
));
737 // Read the symbol table entry.
738 unsigned int symndx
= shdr
.get_sh_info();
739 if (symndx
>= symshdr
.get_sh_size() / This::sym_size
)
741 this->error(_("section group %u info %u out of range"),
745 off_t symoff
= symshdr
.get_sh_offset() + symndx
* This::sym_size
;
746 const unsigned char* psym
= this->get_view(symoff
, This::sym_size
, true,
748 elfcpp::Sym
<size
, big_endian
> sym(psym
);
750 // Read the symbol table names.
751 section_size_type symnamelen
;
752 const unsigned char* psymnamesu
;
753 psymnamesu
= this->section_contents(this->adjust_shndx(symshdr
.get_sh_link()),
755 const char* psymnames
= reinterpret_cast<const char*>(psymnamesu
);
757 // Get the section group signature.
758 if (sym
.get_st_name() >= symnamelen
)
760 this->error(_("symbol %u name offset %u out of range"),
761 symndx
, sym
.get_st_name());
765 std::string
signature(psymnames
+ sym
.get_st_name());
767 // It seems that some versions of gas will create a section group
768 // associated with a section symbol, and then fail to give a name to
769 // the section symbol. In such a case, use the name of the section.
770 if (signature
[0] == '\0' && sym
.get_st_type() == elfcpp::STT_SECTION
)
773 unsigned int sym_shndx
= this->adjust_sym_shndx(symndx
,
776 if (!is_ordinary
|| sym_shndx
>= this->shnum())
778 this->error(_("symbol %u invalid section index %u"),
782 typename
This::Shdr
member_shdr(shdrs
+ sym_shndx
* This::shdr_size
);
783 if (member_shdr
.get_sh_name() < section_names_size
)
784 signature
= section_names
+ member_shdr
.get_sh_name();
787 // Record this section group in the layout, and see whether we've already
788 // seen one with the same signature.
791 Kept_section
* kept_section
= NULL
;
793 if ((flags
& elfcpp::GRP_COMDAT
) == 0)
795 include_group
= true;
800 include_group
= layout
->find_or_add_kept_section(signature
,
802 true, &kept_section
);
806 size_t count
= shdr
.get_sh_size() / sizeof(elfcpp::Elf_Word
);
808 std::vector
<unsigned int> shndxes
;
809 bool relocate_group
= include_group
&& parameters
->options().relocatable();
811 shndxes
.reserve(count
- 1);
813 for (size_t i
= 1; i
< count
; ++i
)
815 elfcpp::Elf_Word shndx
=
816 this->adjust_shndx(elfcpp::Swap
<32, big_endian
>::readval(pword
+ i
));
819 shndxes
.push_back(shndx
);
821 if (shndx
>= this->shnum())
823 this->error(_("section %u in section group %u out of range"),
828 // Check for an earlier section number, since we're going to get
829 // it wrong--we may have already decided to include the section.
831 this->error(_("invalid section group %u refers to earlier section %u"),
834 // Get the name of the member section.
835 typename
This::Shdr
member_shdr(shdrs
+ shndx
* This::shdr_size
);
836 if (member_shdr
.get_sh_name() >= section_names_size
)
838 // This is an error, but it will be diagnosed eventually
839 // in do_layout, so we don't need to do anything here but
843 std::string
mname(section_names
+ member_shdr
.get_sh_name());
848 kept_section
->add_comdat_section(mname
, shndx
,
849 member_shdr
.get_sh_size());
853 (*omit
)[shndx
] = true;
857 Relobj
* kept_object
= kept_section
->object();
858 if (kept_section
->is_comdat())
860 // Find the corresponding kept section, and store
861 // that info in the discarded section table.
862 unsigned int kept_shndx
;
864 if (kept_section
->find_comdat_section(mname
, &kept_shndx
,
867 // We don't keep a mapping for this section if
868 // it has a different size. The mapping is only
869 // used for relocation processing, and we don't
870 // want to treat the sections as similar if the
871 // sizes are different. Checking the section
872 // size is the approach used by the GNU linker.
873 if (kept_size
== member_shdr
.get_sh_size())
874 this->set_kept_comdat_section(shndx
, kept_object
,
880 // The existing section is a linkonce section. Add
881 // a mapping if there is exactly one section in the
882 // group (which is true when COUNT == 2) and if it
885 && (kept_section
->linkonce_size()
886 == member_shdr
.get_sh_size()))
887 this->set_kept_comdat_section(shndx
, kept_object
,
888 kept_section
->shndx());
895 layout
->layout_group(symtab
, this, index
, name
, signature
.c_str(),
896 shdr
, flags
, &shndxes
);
898 return include_group
;
901 // Whether to include a linkonce section in the link. NAME is the
902 // name of the section and SHDR is the section header.
904 // Linkonce sections are a GNU extension implemented in the original
905 // GNU linker before section groups were defined. The semantics are
906 // that we only include one linkonce section with a given name. The
907 // name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
908 // where T is the type of section and SYMNAME is the name of a symbol.
909 // In an attempt to make linkonce sections interact well with section
910 // groups, we try to identify SYMNAME and use it like a section group
911 // signature. We want to block section groups with that signature,
912 // but not other linkonce sections with that signature. We also use
913 // the full name of the linkonce section as a normal section group
916 template<int size
, bool big_endian
>
918 Sized_relobj
<size
, big_endian
>::include_linkonce_section(
922 const elfcpp::Shdr
<size
, big_endian
>& shdr
)
924 typename
elfcpp::Elf_types
<size
>::Elf_WXword sh_size
= shdr
.get_sh_size();
925 // In general the symbol name we want will be the string following
926 // the last '.'. However, we have to handle the case of
927 // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
928 // some versions of gcc. So we use a heuristic: if the name starts
929 // with ".gnu.linkonce.t.", we use everything after that. Otherwise
930 // we look for the last '.'. We can't always simply skip
931 // ".gnu.linkonce.X", because we have to deal with cases like
932 // ".gnu.linkonce.d.rel.ro.local".
933 const char* const linkonce_t
= ".gnu.linkonce.t.";
935 if (strncmp(name
, linkonce_t
, strlen(linkonce_t
)) == 0)
936 symname
= name
+ strlen(linkonce_t
);
938 symname
= strrchr(name
, '.') + 1;
939 std::string
sig1(symname
);
940 std::string
sig2(name
);
943 bool include1
= layout
->find_or_add_kept_section(sig1
, this, index
, false,
945 bool include2
= layout
->find_or_add_kept_section(sig2
, this, index
, false,
950 // We are not including this section because we already saw the
951 // name of the section as a signature. This normally implies
952 // that the kept section is another linkonce section. If it is
953 // the same size, record it as the section which corresponds to
955 if (kept2
->object() != NULL
956 && !kept2
->is_comdat()
957 && kept2
->linkonce_size() == sh_size
)
958 this->set_kept_comdat_section(index
, kept2
->object(), kept2
->shndx());
962 // The section is being discarded on the basis of its symbol
963 // name. This means that the corresponding kept section was
964 // part of a comdat group, and it will be difficult to identify
965 // the specific section within that group that corresponds to
966 // this linkonce section. We'll handle the simple case where
967 // the group has only one member section. Otherwise, it's not
969 unsigned int kept_shndx
;
971 if (kept1
->object() != NULL
972 && kept1
->is_comdat()
973 && kept1
->find_single_comdat_section(&kept_shndx
, &kept_size
)
974 && kept_size
== sh_size
)
975 this->set_kept_comdat_section(index
, kept1
->object(), kept_shndx
);
979 kept1
->set_linkonce_size(sh_size
);
980 kept2
->set_linkonce_size(sh_size
);
983 return include1
&& include2
;
986 // Layout an input section.
988 template<int size
, bool big_endian
>
990 Sized_relobj
<size
, big_endian
>::layout_section(Layout
* layout
,
993 typename
This::Shdr
& shdr
,
994 unsigned int reloc_shndx
,
995 unsigned int reloc_type
)
998 Output_section
* os
= layout
->layout(this, shndx
, name
, shdr
,
999 reloc_shndx
, reloc_type
, &offset
);
1001 this->output_sections()[shndx
] = os
;
1003 this->section_offsets_
[shndx
] = invalid_address
;
1005 this->section_offsets_
[shndx
] = convert_types
<Address
, off_t
>(offset
);
1007 // If this section requires special handling, and if there are
1008 // relocs that apply to it, then we must do the special handling
1009 // before we apply the relocs.
1010 if (offset
== -1 && reloc_shndx
!= 0)
1011 this->set_relocs_must_follow_section_writes();
1014 // Lay out the input sections. We walk through the sections and check
1015 // whether they should be included in the link. If they should, we
1016 // pass them to the Layout object, which will return an output section
1018 // During garbage collection (--gc-sections) and identical code folding
1019 // (--icf), this function is called twice. When it is called the first
1020 // time, it is for setting up some sections as roots to a work-list for
1021 // --gc-sections and to do comdat processing. Actual layout happens the
1022 // second time around after all the relevant sections have been determined.
1023 // The first time, is_worklist_ready or is_icf_ready is false. It is then
1024 // set to true after the garbage collection worklist or identical code
1025 // folding is processed and the relevant sections to be kept are
1026 // determined. Then, this function is called again to layout the sections.
1028 template<int size
, bool big_endian
>
1030 Sized_relobj
<size
, big_endian
>::do_layout(Symbol_table
* symtab
,
1032 Read_symbols_data
* sd
)
1034 const unsigned int shnum
= this->shnum();
1035 bool is_gc_pass_one
= ((parameters
->options().gc_sections()
1036 && !symtab
->gc()->is_worklist_ready())
1037 || (parameters
->options().icf_enabled()
1038 && !symtab
->icf()->is_icf_ready()));
1040 bool is_gc_pass_two
= ((parameters
->options().gc_sections()
1041 && symtab
->gc()->is_worklist_ready())
1042 || (parameters
->options().icf_enabled()
1043 && symtab
->icf()->is_icf_ready()));
1045 bool is_gc_or_icf
= (parameters
->options().gc_sections()
1046 || parameters
->options().icf_enabled());
1048 // Both is_gc_pass_one and is_gc_pass_two should not be true.
1049 gold_assert(!(is_gc_pass_one
&& is_gc_pass_two
));
1053 Symbols_data
* gc_sd
= NULL
;
1056 // During garbage collection save the symbols data to use it when
1057 // re-entering this function.
1058 gc_sd
= new Symbols_data
;
1059 this->copy_symbols_data(gc_sd
, sd
, This::shdr_size
* shnum
);
1060 this->set_symbols_data(gc_sd
);
1062 else if (is_gc_pass_two
)
1064 gc_sd
= this->get_symbols_data();
1067 const unsigned char* section_headers_data
= NULL
;
1068 section_size_type section_names_size
;
1069 const unsigned char* symbols_data
= NULL
;
1070 section_size_type symbols_size
;
1071 section_offset_type external_symbols_offset
;
1072 const unsigned char* symbol_names_data
= NULL
;
1073 section_size_type symbol_names_size
;
1077 section_headers_data
= gc_sd
->section_headers_data
;
1078 section_names_size
= gc_sd
->section_names_size
;
1079 symbols_data
= gc_sd
->symbols_data
;
1080 symbols_size
= gc_sd
->symbols_size
;
1081 external_symbols_offset
= gc_sd
->external_symbols_offset
;
1082 symbol_names_data
= gc_sd
->symbol_names_data
;
1083 symbol_names_size
= gc_sd
->symbol_names_size
;
1087 section_headers_data
= sd
->section_headers
->data();
1088 section_names_size
= sd
->section_names_size
;
1089 if (sd
->symbols
!= NULL
)
1090 symbols_data
= sd
->symbols
->data();
1091 symbols_size
= sd
->symbols_size
;
1092 external_symbols_offset
= sd
->external_symbols_offset
;
1093 if (sd
->symbol_names
!= NULL
)
1094 symbol_names_data
= sd
->symbol_names
->data();
1095 symbol_names_size
= sd
->symbol_names_size
;
1098 // Get the section headers.
1099 const unsigned char* shdrs
= section_headers_data
;
1100 const unsigned char* pshdrs
;
1102 // Get the section names.
1103 const unsigned char* pnamesu
= (is_gc_or_icf
)
1104 ? gc_sd
->section_names_data
1105 : sd
->section_names
->data();
1107 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
1109 // If any input files have been claimed by plugins, we need to defer
1110 // actual layout until the replacement files have arrived.
1111 const bool should_defer_layout
=
1112 (parameters
->options().has_plugins()
1113 && parameters
->options().plugins()->should_defer_layout());
1114 unsigned int num_sections_to_defer
= 0;
1116 // For each section, record the index of the reloc section if any.
1117 // Use 0 to mean that there is no reloc section, -1U to mean that
1118 // there is more than one.
1119 std::vector
<unsigned int> reloc_shndx(shnum
, 0);
1120 std::vector
<unsigned int> reloc_type(shnum
, elfcpp::SHT_NULL
);
1121 // Skip the first, dummy, section.
1122 pshdrs
= shdrs
+ This::shdr_size
;
1123 for (unsigned int i
= 1; i
< shnum
; ++i
, pshdrs
+= This::shdr_size
)
1125 typename
This::Shdr
shdr(pshdrs
);
1127 // Count the number of sections whose layout will be deferred.
1128 if (should_defer_layout
&& (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
))
1129 ++num_sections_to_defer
;
1131 unsigned int sh_type
= shdr
.get_sh_type();
1132 if (sh_type
== elfcpp::SHT_REL
|| sh_type
== elfcpp::SHT_RELA
)
1134 unsigned int target_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1135 if (target_shndx
== 0 || target_shndx
>= shnum
)
1137 this->error(_("relocation section %u has bad info %u"),
1142 if (reloc_shndx
[target_shndx
] != 0)
1143 reloc_shndx
[target_shndx
] = -1U;
1146 reloc_shndx
[target_shndx
] = i
;
1147 reloc_type
[target_shndx
] = sh_type
;
1152 Output_sections
& out_sections(this->output_sections());
1153 std::vector
<Address
>& out_section_offsets(this->section_offsets_
);
1155 if (!is_gc_pass_two
)
1157 out_sections
.resize(shnum
);
1158 out_section_offsets
.resize(shnum
);
1161 // If we are only linking for symbols, then there is nothing else to
1163 if (this->input_file()->just_symbols())
1165 if (!is_gc_pass_two
)
1167 delete sd
->section_headers
;
1168 sd
->section_headers
= NULL
;
1169 delete sd
->section_names
;
1170 sd
->section_names
= NULL
;
1175 if (num_sections_to_defer
> 0)
1177 parameters
->options().plugins()->add_deferred_layout_object(this);
1178 this->deferred_layout_
.reserve(num_sections_to_defer
);
1181 // Whether we've seen a .note.GNU-stack section.
1182 bool seen_gnu_stack
= false;
1183 // The flags of a .note.GNU-stack section.
1184 uint64_t gnu_stack_flags
= 0;
1186 // Keep track of which sections to omit.
1187 std::vector
<bool> omit(shnum
, false);
1189 // Keep track of reloc sections when emitting relocations.
1190 const bool relocatable
= parameters
->options().relocatable();
1191 const bool emit_relocs
= (relocatable
1192 || parameters
->options().emit_relocs());
1193 std::vector
<unsigned int> reloc_sections
;
1195 // Keep track of .eh_frame sections.
1196 std::vector
<unsigned int> eh_frame_sections
;
1198 // Skip the first, dummy, section.
1199 pshdrs
= shdrs
+ This::shdr_size
;
1200 for (unsigned int i
= 1; i
< shnum
; ++i
, pshdrs
+= This::shdr_size
)
1202 typename
This::Shdr
shdr(pshdrs
);
1204 if (shdr
.get_sh_name() >= section_names_size
)
1206 this->error(_("bad section name offset for section %u: %lu"),
1207 i
, static_cast<unsigned long>(shdr
.get_sh_name()));
1211 const char* name
= pnames
+ shdr
.get_sh_name();
1213 if (!is_gc_pass_two
)
1215 if (this->handle_gnu_warning_section(name
, i
, symtab
))
1221 // The .note.GNU-stack section is special. It gives the
1222 // protection flags that this object file requires for the stack
1224 if (strcmp(name
, ".note.GNU-stack") == 0)
1226 seen_gnu_stack
= true;
1227 gnu_stack_flags
|= shdr
.get_sh_flags();
1231 // The .note.GNU-split-stack section is also special. It
1232 // indicates that the object was compiled with
1234 if (this->handle_split_stack_section(name
))
1236 if (!parameters
->options().relocatable()
1237 && !parameters
->options().shared())
1241 // Skip attributes section.
1242 if (parameters
->target().is_attributes_section(name
))
1247 bool discard
= omit
[i
];
1250 if (shdr
.get_sh_type() == elfcpp::SHT_GROUP
)
1252 if (!this->include_section_group(symtab
, layout
, i
, name
,
1258 else if ((shdr
.get_sh_flags() & elfcpp::SHF_GROUP
) == 0
1259 && Layout::is_linkonce(name
))
1261 if (!this->include_linkonce_section(layout
, i
, name
, shdr
))
1266 // Add the section to the incremental inputs layout.
1267 Incremental_inputs
* incremental_inputs
= layout
->incremental_inputs();
1268 if (incremental_inputs
!= NULL
)
1269 incremental_inputs
->report_input_section(this, i
,
1270 discard
? NULL
: name
,
1271 shdr
.get_sh_size());
1275 // Do not include this section in the link.
1276 out_sections
[i
] = NULL
;
1277 out_section_offsets
[i
] = invalid_address
;
1282 if (is_gc_pass_one
&& parameters
->options().gc_sections())
1284 if (is_section_name_included(name
)
1285 || shdr
.get_sh_type() == elfcpp::SHT_INIT_ARRAY
1286 || shdr
.get_sh_type() == elfcpp::SHT_FINI_ARRAY
)
1288 symtab
->gc()->worklist().push(Section_id(this, i
));
1290 // If the section name XXX can be represented as a C identifier
1291 // it cannot be discarded if there are references to
1292 // __start_XXX and __stop_XXX symbols. These need to be
1293 // specially handled.
1294 if (is_cident(name
))
1296 symtab
->gc()->add_cident_section(name
, Section_id(this, i
));
1300 // When doing a relocatable link we are going to copy input
1301 // reloc sections into the output. We only want to copy the
1302 // ones associated with sections which are not being discarded.
1303 // However, we don't know that yet for all sections. So save
1304 // reloc sections and process them later. Garbage collection is
1305 // not triggered when relocatable code is desired.
1307 && (shdr
.get_sh_type() == elfcpp::SHT_REL
1308 || shdr
.get_sh_type() == elfcpp::SHT_RELA
))
1310 reloc_sections
.push_back(i
);
1314 if (relocatable
&& shdr
.get_sh_type() == elfcpp::SHT_GROUP
)
1317 // The .eh_frame section is special. It holds exception frame
1318 // information that we need to read in order to generate the
1319 // exception frame header. We process these after all the other
1320 // sections so that the exception frame reader can reliably
1321 // determine which sections are being discarded, and discard the
1322 // corresponding information.
1324 && strcmp(name
, ".eh_frame") == 0
1325 && this->check_eh_frame_flags(&shdr
))
1329 out_sections
[i
] = reinterpret_cast<Output_section
*>(1);
1330 out_section_offsets
[i
] = invalid_address
;
1333 eh_frame_sections
.push_back(i
);
1337 if (is_gc_pass_two
&& parameters
->options().gc_sections())
1339 // This is executed during the second pass of garbage
1340 // collection. do_layout has been called before and some
1341 // sections have been already discarded. Simply ignore
1342 // such sections this time around.
1343 if (out_sections
[i
] == NULL
)
1345 gold_assert(out_section_offsets
[i
] == invalid_address
);
1348 if (((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0)
1349 && symtab
->gc()->is_section_garbage(this, i
))
1351 if (parameters
->options().print_gc_sections())
1352 gold_info(_("%s: removing unused section from '%s'"
1354 program_name
, this->section_name(i
).c_str(),
1355 this->name().c_str());
1356 out_sections
[i
] = NULL
;
1357 out_section_offsets
[i
] = invalid_address
;
1362 if (is_gc_pass_two
&& parameters
->options().icf_enabled())
1364 if (out_sections
[i
] == NULL
)
1366 gold_assert(out_section_offsets
[i
] == invalid_address
);
1369 if (((shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
) != 0)
1370 && symtab
->icf()->is_section_folded(this, i
))
1372 if (parameters
->options().print_icf_sections())
1375 symtab
->icf()->get_folded_section(this, i
);
1376 Relobj
* folded_obj
=
1377 reinterpret_cast<Relobj
*>(folded
.first
);
1378 gold_info(_("%s: ICF folding section '%s' in file '%s'"
1379 "into '%s' in file '%s'"),
1380 program_name
, this->section_name(i
).c_str(),
1381 this->name().c_str(),
1382 folded_obj
->section_name(folded
.second
).c_str(),
1383 folded_obj
->name().c_str());
1385 out_sections
[i
] = NULL
;
1386 out_section_offsets
[i
] = invalid_address
;
1391 // Defer layout here if input files are claimed by plugins. When gc
1392 // is turned on this function is called twice. For the second call
1393 // should_defer_layout should be false.
1394 if (should_defer_layout
&& (shdr
.get_sh_flags() & elfcpp::SHF_ALLOC
))
1396 gold_assert(!is_gc_pass_two
);
1397 this->deferred_layout_
.push_back(Deferred_layout(i
, name
,
1401 // Put dummy values here; real values will be supplied by
1402 // do_layout_deferred_sections.
1403 out_sections
[i
] = reinterpret_cast<Output_section
*>(2);
1404 out_section_offsets
[i
] = invalid_address
;
1408 // During gc_pass_two if a section that was previously deferred is
1409 // found, do not layout the section as layout_deferred_sections will
1410 // do it later from gold.cc.
1412 && (out_sections
[i
] == reinterpret_cast<Output_section
*>(2)))
1417 // This is during garbage collection. The out_sections are
1418 // assigned in the second call to this function.
1419 out_sections
[i
] = reinterpret_cast<Output_section
*>(1);
1420 out_section_offsets
[i
] = invalid_address
;
1424 // When garbage collection is switched on the actual layout
1425 // only happens in the second call.
1426 this->layout_section(layout
, i
, name
, shdr
, reloc_shndx
[i
],
1431 if (!is_gc_pass_two
)
1432 layout
->layout_gnu_stack(seen_gnu_stack
, gnu_stack_flags
, this);
1434 // When doing a relocatable link handle the reloc sections at the
1435 // end. Garbage collection and Identical Code Folding is not
1436 // turned on for relocatable code.
1438 this->size_relocatable_relocs();
1440 gold_assert(!(is_gc_or_icf
) || reloc_sections
.empty());
1442 for (std::vector
<unsigned int>::const_iterator p
= reloc_sections
.begin();
1443 p
!= reloc_sections
.end();
1446 unsigned int i
= *p
;
1447 const unsigned char* pshdr
;
1448 pshdr
= section_headers_data
+ i
* This::shdr_size
;
1449 typename
This::Shdr
shdr(pshdr
);
1451 unsigned int data_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1452 if (data_shndx
>= shnum
)
1454 // We already warned about this above.
1458 Output_section
* data_section
= out_sections
[data_shndx
];
1459 if (data_section
== reinterpret_cast<Output_section
*>(2))
1461 // The layout for the data section was deferred, so we need
1462 // to defer the relocation section, too.
1463 const char* name
= pnames
+ shdr
.get_sh_name();
1464 this->deferred_layout_relocs_
.push_back(
1465 Deferred_layout(i
, name
, pshdr
, 0, elfcpp::SHT_NULL
));
1466 out_sections
[i
] = reinterpret_cast<Output_section
*>(2);
1467 out_section_offsets
[i
] = invalid_address
;
1470 if (data_section
== NULL
)
1472 out_sections
[i
] = NULL
;
1473 out_section_offsets
[i
] = invalid_address
;
1477 Relocatable_relocs
* rr
= new Relocatable_relocs();
1478 this->set_relocatable_relocs(i
, rr
);
1480 Output_section
* os
= layout
->layout_reloc(this, i
, shdr
, data_section
,
1482 out_sections
[i
] = os
;
1483 out_section_offsets
[i
] = invalid_address
;
1486 // Handle the .eh_frame sections at the end.
1487 gold_assert(!is_gc_pass_one
|| eh_frame_sections
.empty());
1488 for (std::vector
<unsigned int>::const_iterator p
= eh_frame_sections
.begin();
1489 p
!= eh_frame_sections
.end();
1492 gold_assert(this->has_eh_frame_
);
1493 gold_assert(external_symbols_offset
!= 0);
1495 unsigned int i
= *p
;
1496 const unsigned char* pshdr
;
1497 pshdr
= section_headers_data
+ i
* This::shdr_size
;
1498 typename
This::Shdr
shdr(pshdr
);
1501 Output_section
* os
= layout
->layout_eh_frame(this,
1510 out_sections
[i
] = os
;
1511 if (os
== NULL
|| offset
== -1)
1513 // An object can contain at most one section holding exception
1514 // frame information.
1515 gold_assert(this->discarded_eh_frame_shndx_
== -1U);
1516 this->discarded_eh_frame_shndx_
= i
;
1517 out_section_offsets
[i
] = invalid_address
;
1520 out_section_offsets
[i
] = convert_types
<Address
, off_t
>(offset
);
1522 // If this section requires special handling, and if there are
1523 // relocs that apply to it, then we must do the special handling
1524 // before we apply the relocs.
1525 if (os
!= NULL
&& offset
== -1 && reloc_shndx
[i
] != 0)
1526 this->set_relocs_must_follow_section_writes();
1531 delete[] gc_sd
->section_headers_data
;
1532 delete[] gc_sd
->section_names_data
;
1533 delete[] gc_sd
->symbols_data
;
1534 delete[] gc_sd
->symbol_names_data
;
1535 this->set_symbols_data(NULL
);
1539 delete sd
->section_headers
;
1540 sd
->section_headers
= NULL
;
1541 delete sd
->section_names
;
1542 sd
->section_names
= NULL
;
1546 // Layout sections whose layout was deferred while waiting for
1547 // input files from a plugin.
1549 template<int size
, bool big_endian
>
1551 Sized_relobj
<size
, big_endian
>::do_layout_deferred_sections(Layout
* layout
)
1553 typename
std::vector
<Deferred_layout
>::iterator deferred
;
1555 for (deferred
= this->deferred_layout_
.begin();
1556 deferred
!= this->deferred_layout_
.end();
1559 typename
This::Shdr
shdr(deferred
->shdr_data_
);
1560 // If the section is not included, it is because the garbage collector
1561 // decided it is not needed. Avoid reverting that decision.
1562 if (!this->is_section_included(deferred
->shndx_
))
1565 this->layout_section(layout
, deferred
->shndx_
, deferred
->name_
.c_str(),
1566 shdr
, deferred
->reloc_shndx_
, deferred
->reloc_type_
);
1569 this->deferred_layout_
.clear();
1571 // Now handle the deferred relocation sections.
1573 Output_sections
& out_sections(this->output_sections());
1574 std::vector
<Address
>& out_section_offsets(this->section_offsets_
);
1576 for (deferred
= this->deferred_layout_relocs_
.begin();
1577 deferred
!= this->deferred_layout_relocs_
.end();
1580 unsigned int shndx
= deferred
->shndx_
;
1581 typename
This::Shdr
shdr(deferred
->shdr_data_
);
1582 unsigned int data_shndx
= this->adjust_shndx(shdr
.get_sh_info());
1584 Output_section
* data_section
= out_sections
[data_shndx
];
1585 if (data_section
== NULL
)
1587 out_sections
[shndx
] = NULL
;
1588 out_section_offsets
[shndx
] = invalid_address
;
1592 Relocatable_relocs
* rr
= new Relocatable_relocs();
1593 this->set_relocatable_relocs(shndx
, rr
);
1595 Output_section
* os
= layout
->layout_reloc(this, shndx
, shdr
,
1597 out_sections
[shndx
] = os
;
1598 out_section_offsets
[shndx
] = invalid_address
;
1602 // Add the symbols to the symbol table.
1604 template<int size
, bool big_endian
>
1606 Sized_relobj
<size
, big_endian
>::do_add_symbols(Symbol_table
* symtab
,
1607 Read_symbols_data
* sd
,
1610 if (sd
->symbols
== NULL
)
1612 gold_assert(sd
->symbol_names
== NULL
);
1616 const int sym_size
= This::sym_size
;
1617 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1619 if (symcount
* sym_size
!= sd
->symbols_size
- sd
->external_symbols_offset
)
1621 this->error(_("size of symbols is not multiple of symbol size"));
1625 this->symbols_
.resize(symcount
);
1627 const char* sym_names
=
1628 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1629 symtab
->add_from_relobj(this,
1630 sd
->symbols
->data() + sd
->external_symbols_offset
,
1631 symcount
, this->local_symbol_count_
,
1632 sym_names
, sd
->symbol_names_size
,
1634 &this->defined_count_
);
1638 delete sd
->symbol_names
;
1639 sd
->symbol_names
= NULL
;
1642 // Find out if this object, that is a member of a lib group, should be included
1643 // in the link. We check every symbol defined by this object. If the symbol
1644 // table has a strong undefined reference to that symbol, we have to include
1647 template<int size
, bool big_endian
>
1648 Archive::Should_include
1649 Sized_relobj
<size
, big_endian
>::do_should_include_member(Symbol_table
* symtab
,
1651 Read_symbols_data
* sd
,
1654 char* tmpbuf
= NULL
;
1655 size_t tmpbuflen
= 0;
1656 const char* sym_names
=
1657 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1658 const unsigned char* syms
=
1659 sd
->symbols
->data() + sd
->external_symbols_offset
;
1660 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1661 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1664 const unsigned char* p
= syms
;
1666 for (size_t i
= 0; i
< symcount
; ++i
, p
+= sym_size
)
1668 elfcpp::Sym
<size
, big_endian
> sym(p
);
1669 unsigned int st_shndx
= sym
.get_st_shndx();
1670 if (st_shndx
== elfcpp::SHN_UNDEF
)
1673 unsigned int st_name
= sym
.get_st_name();
1674 const char* name
= sym_names
+ st_name
;
1676 Archive::Should_include t
= Archive::should_include_member(symtab
,
1682 if (t
== Archive::SHOULD_INCLUDE_YES
)
1691 return Archive::SHOULD_INCLUDE_UNKNOWN
;
1694 // Iterate over global defined symbols, calling a visitor class V for each.
1696 template<int size
, bool big_endian
>
1698 Sized_relobj
<size
, big_endian
>::do_for_all_global_symbols(
1699 Read_symbols_data
* sd
,
1700 Library_base::Symbol_visitor_base
* v
)
1702 const char* sym_names
=
1703 reinterpret_cast<const char*>(sd
->symbol_names
->data());
1704 const unsigned char* syms
=
1705 sd
->symbols
->data() + sd
->external_symbols_offset
;
1706 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1707 size_t symcount
= ((sd
->symbols_size
- sd
->external_symbols_offset
)
1709 const unsigned char* p
= syms
;
1711 for (size_t i
= 0; i
< symcount
; ++i
, p
+= sym_size
)
1713 elfcpp::Sym
<size
, big_endian
> sym(p
);
1714 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
1715 v
->visit(sym_names
+ sym
.get_st_name());
1719 // Return whether the local symbol SYMNDX has a PLT offset.
1721 template<int size
, bool big_endian
>
1723 Sized_relobj
<size
, big_endian
>::local_has_plt_offset(unsigned int symndx
) const
1725 typename
Local_plt_offsets::const_iterator p
=
1726 this->local_plt_offsets_
.find(symndx
);
1727 return p
!= this->local_plt_offsets_
.end();
1730 // Get the PLT offset of a local symbol.
1732 template<int size
, bool big_endian
>
1734 Sized_relobj
<size
, big_endian
>::local_plt_offset(unsigned int symndx
) const
1736 typename
Local_plt_offsets::const_iterator p
=
1737 this->local_plt_offsets_
.find(symndx
);
1738 gold_assert(p
!= this->local_plt_offsets_
.end());
1742 // Set the PLT offset of a local symbol.
1744 template<int size
, bool big_endian
>
1746 Sized_relobj
<size
, big_endian
>::set_local_plt_offset(unsigned int symndx
,
1747 unsigned int plt_offset
)
1749 std::pair
<typename
Local_plt_offsets::iterator
, bool> ins
=
1750 this->local_plt_offsets_
.insert(std::make_pair(symndx
, plt_offset
));
1751 gold_assert(ins
.second
);
1754 // First pass over the local symbols. Here we add their names to
1755 // *POOL and *DYNPOOL, and we store the symbol value in
1756 // THIS->LOCAL_VALUES_. This function is always called from a
1757 // singleton thread. This is followed by a call to
1758 // finalize_local_symbols.
1760 template<int size
, bool big_endian
>
1762 Sized_relobj
<size
, big_endian
>::do_count_local_symbols(Stringpool
* pool
,
1763 Stringpool
* dynpool
)
1765 gold_assert(this->symtab_shndx_
!= -1U);
1766 if (this->symtab_shndx_
== 0)
1768 // This object has no symbols. Weird but legal.
1772 // Read the symbol table section header.
1773 const unsigned int symtab_shndx
= this->symtab_shndx_
;
1774 typename
This::Shdr
symtabshdr(this,
1775 this->elf_file_
.section_header(symtab_shndx
));
1776 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
1778 // Read the local symbols.
1779 const int sym_size
= This::sym_size
;
1780 const unsigned int loccount
= this->local_symbol_count_
;
1781 gold_assert(loccount
== symtabshdr
.get_sh_info());
1782 off_t locsize
= loccount
* sym_size
;
1783 const unsigned char* psyms
= this->get_view(symtabshdr
.get_sh_offset(),
1784 locsize
, true, true);
1786 // Read the symbol names.
1787 const unsigned int strtab_shndx
=
1788 this->adjust_shndx(symtabshdr
.get_sh_link());
1789 section_size_type strtab_size
;
1790 const unsigned char* pnamesu
= this->section_contents(strtab_shndx
,
1793 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
1795 // Loop over the local symbols.
1797 const Output_sections
& out_sections(this->output_sections());
1798 unsigned int shnum
= this->shnum();
1799 unsigned int count
= 0;
1800 unsigned int dyncount
= 0;
1801 // Skip the first, dummy, symbol.
1803 bool discard_all
= parameters
->options().discard_all();
1804 bool discard_locals
= parameters
->options().discard_locals();
1805 for (unsigned int i
= 1; i
< loccount
; ++i
, psyms
+= sym_size
)
1807 elfcpp::Sym
<size
, big_endian
> sym(psyms
);
1809 Symbol_value
<size
>& lv(this->local_values_
[i
]);
1812 unsigned int shndx
= this->adjust_sym_shndx(i
, sym
.get_st_shndx(),
1814 lv
.set_input_shndx(shndx
, is_ordinary
);
1816 if (sym
.get_st_type() == elfcpp::STT_SECTION
)
1817 lv
.set_is_section_symbol();
1818 else if (sym
.get_st_type() == elfcpp::STT_TLS
)
1819 lv
.set_is_tls_symbol();
1820 else if (sym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1821 lv
.set_is_ifunc_symbol();
1823 // Save the input symbol value for use in do_finalize_local_symbols().
1824 lv
.set_input_value(sym
.get_st_value());
1826 // Decide whether this symbol should go into the output file.
1828 if ((shndx
< shnum
&& out_sections
[shndx
] == NULL
)
1829 || shndx
== this->discarded_eh_frame_shndx_
)
1831 lv
.set_no_output_symtab_entry();
1832 gold_assert(!lv
.needs_output_dynsym_entry());
1836 if (sym
.get_st_type() == elfcpp::STT_SECTION
)
1838 lv
.set_no_output_symtab_entry();
1839 gold_assert(!lv
.needs_output_dynsym_entry());
1843 if (sym
.get_st_name() >= strtab_size
)
1845 this->error(_("local symbol %u section name out of range: %u >= %u"),
1846 i
, sym
.get_st_name(),
1847 static_cast<unsigned int>(strtab_size
));
1848 lv
.set_no_output_symtab_entry();
1852 const char* name
= pnames
+ sym
.get_st_name();
1854 // If needed, add the symbol to the dynamic symbol table string pool.
1855 if (lv
.needs_output_dynsym_entry())
1857 dynpool
->add(name
, true, NULL
);
1861 if (discard_all
&& lv
.may_be_discarded_from_output_symtab())
1863 lv
.set_no_output_symtab_entry();
1867 // If --discard-locals option is used, discard all temporary local
1868 // symbols. These symbols start with system-specific local label
1869 // prefixes, typically .L for ELF system. We want to be compatible
1870 // with GNU ld so here we essentially use the same check in
1871 // bfd_is_local_label(). The code is different because we already
1874 // - the symbol is local and thus cannot have global or weak binding.
1875 // - the symbol is not a section symbol.
1876 // - the symbol has a name.
1878 // We do not discard a symbol if it needs a dynamic symbol entry.
1880 && sym
.get_st_type() != elfcpp::STT_FILE
1881 && !lv
.needs_output_dynsym_entry()
1882 && lv
.may_be_discarded_from_output_symtab()
1883 && parameters
->target().is_local_label_name(name
))
1885 lv
.set_no_output_symtab_entry();
1889 // Discard the local symbol if -retain_symbols_file is specified
1890 // and the local symbol is not in that file.
1891 if (!parameters
->options().should_retain_symbol(name
))
1893 lv
.set_no_output_symtab_entry();
1897 // Add the symbol to the symbol table string pool.
1898 pool
->add(name
, true, NULL
);
1902 this->output_local_symbol_count_
= count
;
1903 this->output_local_dynsym_count_
= dyncount
;
1906 // Compute the final value of a local symbol.
1908 template<int size
, bool big_endian
>
1909 typename Sized_relobj
<size
, big_endian
>::Compute_final_local_value_status
1910 Sized_relobj
<size
, big_endian
>::compute_final_local_value_internal(
1912 const Symbol_value
<size
>* lv_in
,
1913 Symbol_value
<size
>* lv_out
,
1915 const Output_sections
& out_sections
,
1916 const std::vector
<Address
>& out_offsets
,
1917 const Symbol_table
* symtab
)
1919 // We are going to overwrite *LV_OUT, if it has a merged symbol value,
1920 // we may have a memory leak.
1921 gold_assert(lv_out
->has_output_value());
1924 unsigned int shndx
= lv_in
->input_shndx(&is_ordinary
);
1926 // Set the output symbol value.
1930 if (shndx
== elfcpp::SHN_ABS
|| Symbol::is_common_shndx(shndx
))
1931 lv_out
->set_output_value(lv_in
->input_value());
1934 this->error(_("unknown section index %u for local symbol %u"),
1936 lv_out
->set_output_value(0);
1937 return This::CFLV_ERROR
;
1942 if (shndx
>= this->shnum())
1944 this->error(_("local symbol %u section index %u out of range"),
1946 lv_out
->set_output_value(0);
1947 return This::CFLV_ERROR
;
1950 Output_section
* os
= out_sections
[shndx
];
1951 Address secoffset
= out_offsets
[shndx
];
1952 if (symtab
->is_section_folded(this, shndx
))
1954 gold_assert(os
== NULL
&& secoffset
== invalid_address
);
1955 // Get the os of the section it is folded onto.
1956 Section_id folded
= symtab
->icf()->get_folded_section(this,
1958 gold_assert(folded
.first
!= NULL
);
1959 Sized_relobj
<size
, big_endian
>* folded_obj
= reinterpret_cast
1960 <Sized_relobj
<size
, big_endian
>*>(folded
.first
);
1961 os
= folded_obj
->output_section(folded
.second
);
1962 gold_assert(os
!= NULL
);
1963 secoffset
= folded_obj
->get_output_section_offset(folded
.second
);
1965 // This could be a relaxed input section.
1966 if (secoffset
== invalid_address
)
1968 const Output_relaxed_input_section
* relaxed_section
=
1969 os
->find_relaxed_input_section(folded_obj
, folded
.second
);
1970 gold_assert(relaxed_section
!= NULL
);
1971 secoffset
= relaxed_section
->address() - os
->address();
1977 // This local symbol belongs to a section we are discarding.
1978 // In some cases when applying relocations later, we will
1979 // attempt to match it to the corresponding kept section,
1980 // so we leave the input value unchanged here.
1981 return This::CFLV_DISCARDED
;
1983 else if (secoffset
== invalid_address
)
1987 // This is a SHF_MERGE section or one which otherwise
1988 // requires special handling.
1989 if (shndx
== this->discarded_eh_frame_shndx_
)
1991 // This local symbol belongs to a discarded .eh_frame
1992 // section. Just treat it like the case in which
1993 // os == NULL above.
1994 gold_assert(this->has_eh_frame_
);
1995 return This::CFLV_DISCARDED
;
1997 else if (!lv_in
->is_section_symbol())
1999 // This is not a section symbol. We can determine
2000 // the final value now.
2001 lv_out
->set_output_value(
2002 os
->output_address(this, shndx
, lv_in
->input_value()));
2004 else if (!os
->find_starting_output_address(this, shndx
, &start
))
2006 // This is a section symbol, but apparently not one in a
2007 // merged section. First check to see if this is a relaxed
2008 // input section. If so, use its address. Otherwise just
2009 // use the start of the output section. This happens with
2010 // relocatable links when the input object has section
2011 // symbols for arbitrary non-merge sections.
2012 const Output_section_data
* posd
=
2013 os
->find_relaxed_input_section(this, shndx
);
2016 Address relocatable_link_adjustment
=
2017 relocatable
? os
->address() : 0;
2018 lv_out
->set_output_value(posd
->address()
2019 - relocatable_link_adjustment
);
2022 lv_out
->set_output_value(os
->address());
2026 // We have to consider the addend to determine the
2027 // value to use in a relocation. START is the start
2028 // of this input section. If we are doing a relocatable
2029 // link, use offset from start output section instead of
2031 Address adjusted_start
=
2032 relocatable
? start
- os
->address() : start
;
2033 Merged_symbol_value
<size
>* msv
=
2034 new Merged_symbol_value
<size
>(lv_in
->input_value(),
2036 lv_out
->set_merged_symbol_value(msv
);
2039 else if (lv_in
->is_tls_symbol())
2040 lv_out
->set_output_value(os
->tls_offset()
2042 + lv_in
->input_value());
2044 lv_out
->set_output_value((relocatable
? 0 : os
->address())
2046 + lv_in
->input_value());
2048 return This::CFLV_OK
;
2051 // Compute final local symbol value. R_SYM is the index of a local
2052 // symbol in symbol table. LV points to a symbol value, which is
2053 // expected to hold the input value and to be over-written by the
2054 // final value. SYMTAB points to a symbol table. Some targets may want
2055 // to know would-be-finalized local symbol values in relaxation.
2056 // Hence we provide this method. Since this method updates *LV, a
2057 // callee should make a copy of the original local symbol value and
2058 // use the copy instead of modifying an object's local symbols before
2059 // everything is finalized. The caller should also free up any allocated
2060 // memory in the return value in *LV.
2061 template<int size
, bool big_endian
>
2062 typename Sized_relobj
<size
, big_endian
>::Compute_final_local_value_status
2063 Sized_relobj
<size
, big_endian
>::compute_final_local_value(
2065 const Symbol_value
<size
>* lv_in
,
2066 Symbol_value
<size
>* lv_out
,
2067 const Symbol_table
* symtab
)
2069 // This is just a wrapper of compute_final_local_value_internal.
2070 const bool relocatable
= parameters
->options().relocatable();
2071 const Output_sections
& out_sections(this->output_sections());
2072 const std::vector
<Address
>& out_offsets(this->section_offsets_
);
2073 return this->compute_final_local_value_internal(r_sym
, lv_in
, lv_out
,
2074 relocatable
, out_sections
,
2075 out_offsets
, symtab
);
2078 // Finalize the local symbols. Here we set the final value in
2079 // THIS->LOCAL_VALUES_ and set their output symbol table indexes.
2080 // This function is always called from a singleton thread. The actual
2081 // output of the local symbols will occur in a separate task.
2083 template<int size
, bool big_endian
>
2085 Sized_relobj
<size
, big_endian
>::do_finalize_local_symbols(unsigned int index
,
2087 Symbol_table
* symtab
)
2089 gold_assert(off
== static_cast<off_t
>(align_address(off
, size
>> 3)));
2091 const unsigned int loccount
= this->local_symbol_count_
;
2092 this->local_symbol_offset_
= off
;
2094 const bool relocatable
= parameters
->options().relocatable();
2095 const Output_sections
& out_sections(this->output_sections());
2096 const std::vector
<Address
>& out_offsets(this->section_offsets_
);
2098 for (unsigned int i
= 1; i
< loccount
; ++i
)
2100 Symbol_value
<size
>* lv
= &this->local_values_
[i
];
2102 Compute_final_local_value_status cflv_status
=
2103 this->compute_final_local_value_internal(i
, lv
, lv
, relocatable
,
2104 out_sections
, out_offsets
,
2106 switch (cflv_status
)
2109 if (!lv
->is_output_symtab_index_set())
2111 lv
->set_output_symtab_index(index
);
2115 case CFLV_DISCARDED
:
2126 // Set the output dynamic symbol table indexes for the local variables.
2128 template<int size
, bool big_endian
>
2130 Sized_relobj
<size
, big_endian
>::do_set_local_dynsym_indexes(unsigned int index
)
2132 const unsigned int loccount
= this->local_symbol_count_
;
2133 for (unsigned int i
= 1; i
< loccount
; ++i
)
2135 Symbol_value
<size
>& lv(this->local_values_
[i
]);
2136 if (lv
.needs_output_dynsym_entry())
2138 lv
.set_output_dynsym_index(index
);
2145 // Set the offset where local dynamic symbol information will be stored.
2146 // Returns the count of local symbols contributed to the symbol table by
2149 template<int size
, bool big_endian
>
2151 Sized_relobj
<size
, big_endian
>::do_set_local_dynsym_offset(off_t off
)
2153 gold_assert(off
== static_cast<off_t
>(align_address(off
, size
>> 3)));
2154 this->local_dynsym_offset_
= off
;
2155 return this->output_local_dynsym_count_
;
2158 // If Symbols_data is not NULL get the section flags from here otherwise
2159 // get it from the file.
2161 template<int size
, bool big_endian
>
2163 Sized_relobj
<size
, big_endian
>::do_section_flags(unsigned int shndx
)
2165 Symbols_data
* sd
= this->get_symbols_data();
2168 const unsigned char* pshdrs
= sd
->section_headers_data
2169 + This::shdr_size
* shndx
;
2170 typename
This::Shdr
shdr(pshdrs
);
2171 return shdr
.get_sh_flags();
2173 // If sd is NULL, read the section header from the file.
2174 return this->elf_file_
.section_flags(shndx
);
2177 // Get the section's ent size from Symbols_data. Called by get_section_contents
2180 template<int size
, bool big_endian
>
2182 Sized_relobj
<size
, big_endian
>::do_section_entsize(unsigned int shndx
)
2184 Symbols_data
* sd
= this->get_symbols_data();
2185 gold_assert(sd
!= NULL
);
2187 const unsigned char* pshdrs
= sd
->section_headers_data
2188 + This::shdr_size
* shndx
;
2189 typename
This::Shdr
shdr(pshdrs
);
2190 return shdr
.get_sh_entsize();
2193 // Write out the local symbols.
2195 template<int size
, bool big_endian
>
2197 Sized_relobj
<size
, big_endian
>::write_local_symbols(
2199 const Stringpool
* sympool
,
2200 const Stringpool
* dynpool
,
2201 Output_symtab_xindex
* symtab_xindex
,
2202 Output_symtab_xindex
* dynsym_xindex
)
2204 const bool strip_all
= parameters
->options().strip_all();
2207 if (this->output_local_dynsym_count_
== 0)
2209 this->output_local_symbol_count_
= 0;
2212 gold_assert(this->symtab_shndx_
!= -1U);
2213 if (this->symtab_shndx_
== 0)
2215 // This object has no symbols. Weird but legal.
2219 // Read the symbol table section header.
2220 const unsigned int symtab_shndx
= this->symtab_shndx_
;
2221 typename
This::Shdr
symtabshdr(this,
2222 this->elf_file_
.section_header(symtab_shndx
));
2223 gold_assert(symtabshdr
.get_sh_type() == elfcpp::SHT_SYMTAB
);
2224 const unsigned int loccount
= this->local_symbol_count_
;
2225 gold_assert(loccount
== symtabshdr
.get_sh_info());
2227 // Read the local symbols.
2228 const int sym_size
= This::sym_size
;
2229 off_t locsize
= loccount
* sym_size
;
2230 const unsigned char* psyms
= this->get_view(symtabshdr
.get_sh_offset(),
2231 locsize
, true, false);
2233 // Read the symbol names.
2234 const unsigned int strtab_shndx
=
2235 this->adjust_shndx(symtabshdr
.get_sh_link());
2236 section_size_type strtab_size
;
2237 const unsigned char* pnamesu
= this->section_contents(strtab_shndx
,
2240 const char* pnames
= reinterpret_cast<const char*>(pnamesu
);
2242 // Get views into the output file for the portions of the symbol table
2243 // and the dynamic symbol table that we will be writing.
2244 off_t output_size
= this->output_local_symbol_count_
* sym_size
;
2245 unsigned char* oview
= NULL
;
2246 if (output_size
> 0)
2247 oview
= of
->get_output_view(this->local_symbol_offset_
, output_size
);
2249 off_t dyn_output_size
= this->output_local_dynsym_count_
* sym_size
;
2250 unsigned char* dyn_oview
= NULL
;
2251 if (dyn_output_size
> 0)
2252 dyn_oview
= of
->get_output_view(this->local_dynsym_offset_
,
2255 const Output_sections
out_sections(this->output_sections());
2257 gold_assert(this->local_values_
.size() == loccount
);
2259 unsigned char* ov
= oview
;
2260 unsigned char* dyn_ov
= dyn_oview
;
2262 for (unsigned int i
= 1; i
< loccount
; ++i
, psyms
+= sym_size
)
2264 elfcpp::Sym
<size
, big_endian
> isym(psyms
);
2266 Symbol_value
<size
>& lv(this->local_values_
[i
]);
2269 unsigned int st_shndx
= this->adjust_sym_shndx(i
, isym
.get_st_shndx(),
2273 gold_assert(st_shndx
< out_sections
.size());
2274 if (out_sections
[st_shndx
] == NULL
)
2276 st_shndx
= out_sections
[st_shndx
]->out_shndx();
2277 if (st_shndx
>= elfcpp::SHN_LORESERVE
)
2279 if (lv
.has_output_symtab_entry())
2280 symtab_xindex
->add(lv
.output_symtab_index(), st_shndx
);
2281 if (lv
.has_output_dynsym_entry())
2282 dynsym_xindex
->add(lv
.output_dynsym_index(), st_shndx
);
2283 st_shndx
= elfcpp::SHN_XINDEX
;
2287 // Write the symbol to the output symbol table.
2288 if (lv
.has_output_symtab_entry())
2290 elfcpp::Sym_write
<size
, big_endian
> osym(ov
);
2292 gold_assert(isym
.get_st_name() < strtab_size
);
2293 const char* name
= pnames
+ isym
.get_st_name();
2294 osym
.put_st_name(sympool
->get_offset(name
));
2295 osym
.put_st_value(this->local_values_
[i
].value(this, 0));
2296 osym
.put_st_size(isym
.get_st_size());
2297 osym
.put_st_info(isym
.get_st_info());
2298 osym
.put_st_other(isym
.get_st_other());
2299 osym
.put_st_shndx(st_shndx
);
2304 // Write the symbol to the output dynamic symbol table.
2305 if (lv
.has_output_dynsym_entry())
2307 gold_assert(dyn_ov
< dyn_oview
+ dyn_output_size
);
2308 elfcpp::Sym_write
<size
, big_endian
> osym(dyn_ov
);
2310 gold_assert(isym
.get_st_name() < strtab_size
);
2311 const char* name
= pnames
+ isym
.get_st_name();
2312 osym
.put_st_name(dynpool
->get_offset(name
));
2313 osym
.put_st_value(this->local_values_
[i
].value(this, 0));
2314 osym
.put_st_size(isym
.get_st_size());
2315 osym
.put_st_info(isym
.get_st_info());
2316 osym
.put_st_other(isym
.get_st_other());
2317 osym
.put_st_shndx(st_shndx
);
2324 if (output_size
> 0)
2326 gold_assert(ov
- oview
== output_size
);
2327 of
->write_output_view(this->local_symbol_offset_
, output_size
, oview
);
2330 if (dyn_output_size
> 0)
2332 gold_assert(dyn_ov
- dyn_oview
== dyn_output_size
);
2333 of
->write_output_view(this->local_dynsym_offset_
, dyn_output_size
,
2338 // Set *INFO to symbolic information about the offset OFFSET in the
2339 // section SHNDX. Return true if we found something, false if we
2342 template<int size
, bool big_endian
>
2344 Sized_relobj
<size
, big_endian
>::get_symbol_location_info(
2347 Symbol_location_info
* info
)
2349 if (this->symtab_shndx_
== 0)
2352 section_size_type symbols_size
;
2353 const unsigned char* symbols
= this->section_contents(this->symtab_shndx_
,
2357 unsigned int symbol_names_shndx
=
2358 this->adjust_shndx(this->section_link(this->symtab_shndx_
));
2359 section_size_type names_size
;
2360 const unsigned char* symbol_names_u
=
2361 this->section_contents(symbol_names_shndx
, &names_size
, false);
2362 const char* symbol_names
= reinterpret_cast<const char*>(symbol_names_u
);
2364 const int sym_size
= This::sym_size
;
2365 const size_t count
= symbols_size
/ sym_size
;
2367 const unsigned char* p
= symbols
;
2368 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
2370 elfcpp::Sym
<size
, big_endian
> sym(p
);
2372 if (sym
.get_st_type() == elfcpp::STT_FILE
)
2374 if (sym
.get_st_name() >= names_size
)
2375 info
->source_file
= "(invalid)";
2377 info
->source_file
= symbol_names
+ sym
.get_st_name();
2382 unsigned int st_shndx
= this->adjust_sym_shndx(i
, sym
.get_st_shndx(),
2385 && st_shndx
== shndx
2386 && static_cast<off_t
>(sym
.get_st_value()) <= offset
2387 && (static_cast<off_t
>(sym
.get_st_value() + sym
.get_st_size())
2390 if (sym
.get_st_name() > names_size
)
2391 info
->enclosing_symbol_name
= "(invalid)";
2394 info
->enclosing_symbol_name
= symbol_names
+ sym
.get_st_name();
2395 if (parameters
->options().do_demangle())
2397 char* demangled_name
= cplus_demangle(
2398 info
->enclosing_symbol_name
.c_str(),
2399 DMGL_ANSI
| DMGL_PARAMS
);
2400 if (demangled_name
!= NULL
)
2402 info
->enclosing_symbol_name
.assign(demangled_name
);
2403 free(demangled_name
);
2414 // Look for a kept section corresponding to the given discarded section,
2415 // and return its output address. This is used only for relocations in
2416 // debugging sections. If we can't find the kept section, return 0.
2418 template<int size
, bool big_endian
>
2419 typename Sized_relobj
<size
, big_endian
>::Address
2420 Sized_relobj
<size
, big_endian
>::map_to_kept_section(
2424 Relobj
* kept_object
;
2425 unsigned int kept_shndx
;
2426 if (this->get_kept_comdat_section(shndx
, &kept_object
, &kept_shndx
))
2428 Sized_relobj
<size
, big_endian
>* kept_relobj
=
2429 static_cast<Sized_relobj
<size
, big_endian
>*>(kept_object
);
2430 Output_section
* os
= kept_relobj
->output_section(kept_shndx
);
2431 Address offset
= kept_relobj
->get_output_section_offset(kept_shndx
);
2432 if (os
!= NULL
&& offset
!= invalid_address
)
2435 return os
->address() + offset
;
2442 // Get symbol counts.
2444 template<int size
, bool big_endian
>
2446 Sized_relobj
<size
, big_endian
>::do_get_global_symbol_counts(
2447 const Symbol_table
*,
2451 *defined
= this->defined_count_
;
2453 for (Symbols::const_iterator p
= this->symbols_
.begin();
2454 p
!= this->symbols_
.end();
2457 && (*p
)->source() == Symbol::FROM_OBJECT
2458 && (*p
)->object() == this
2459 && (*p
)->is_defined())
2464 // Input_objects methods.
2466 // Add a regular relocatable object to the list. Return false if this
2467 // object should be ignored.
2470 Input_objects::add_object(Object
* obj
)
2472 // Print the filename if the -t/--trace option is selected.
2473 if (parameters
->options().trace())
2474 gold_info("%s", obj
->name().c_str());
2476 if (!obj
->is_dynamic())
2477 this->relobj_list_
.push_back(static_cast<Relobj
*>(obj
));
2480 // See if this is a duplicate SONAME.
2481 Dynobj
* dynobj
= static_cast<Dynobj
*>(obj
);
2482 const char* soname
= dynobj
->soname();
2484 std::pair
<Unordered_set
<std::string
>::iterator
, bool> ins
=
2485 this->sonames_
.insert(soname
);
2488 // We have already seen a dynamic object with this soname.
2492 this->dynobj_list_
.push_back(dynobj
);
2495 // Add this object to the cross-referencer if requested.
2496 if (parameters
->options().user_set_print_symbol_counts()
2497 || parameters
->options().cref())
2499 if (this->cref_
== NULL
)
2500 this->cref_
= new Cref();
2501 this->cref_
->add_object(obj
);
2507 // For each dynamic object, record whether we've seen all of its
2508 // explicit dependencies.
2511 Input_objects::check_dynamic_dependencies() const
2513 bool issued_copy_dt_needed_error
= false;
2514 for (Dynobj_list::const_iterator p
= this->dynobj_list_
.begin();
2515 p
!= this->dynobj_list_
.end();
2518 const Dynobj::Needed
& needed((*p
)->needed());
2519 bool found_all
= true;
2520 Dynobj::Needed::const_iterator pneeded
;
2521 for (pneeded
= needed
.begin(); pneeded
!= needed
.end(); ++pneeded
)
2523 if (this->sonames_
.find(*pneeded
) == this->sonames_
.end())
2529 (*p
)->set_has_unknown_needed_entries(!found_all
);
2531 // --copy-dt-needed-entries aka --add-needed is a GNU ld option
2532 // that gold does not support. However, they cause no trouble
2533 // unless there is a DT_NEEDED entry that we don't know about;
2534 // warn only in that case.
2536 && !issued_copy_dt_needed_error
2537 && (parameters
->options().copy_dt_needed_entries()
2538 || parameters
->options().add_needed()))
2540 const char* optname
;
2541 if (parameters
->options().copy_dt_needed_entries())
2542 optname
= "--copy-dt-needed-entries";
2544 optname
= "--add-needed";
2545 gold_error(_("%s is not supported but is required for %s in %s"),
2546 optname
, (*pneeded
).c_str(), (*p
)->name().c_str());
2547 issued_copy_dt_needed_error
= true;
2552 // Start processing an archive.
2555 Input_objects::archive_start(Archive
* archive
)
2557 if (parameters
->options().user_set_print_symbol_counts()
2558 || parameters
->options().cref())
2560 if (this->cref_
== NULL
)
2561 this->cref_
= new Cref();
2562 this->cref_
->add_archive_start(archive
);
2566 // Stop processing an archive.
2569 Input_objects::archive_stop(Archive
* archive
)
2571 if (parameters
->options().user_set_print_symbol_counts()
2572 || parameters
->options().cref())
2573 this->cref_
->add_archive_stop(archive
);
2576 // Print symbol counts
2579 Input_objects::print_symbol_counts(const Symbol_table
* symtab
) const
2581 if (parameters
->options().user_set_print_symbol_counts()
2582 && this->cref_
!= NULL
)
2583 this->cref_
->print_symbol_counts(symtab
);
2586 // Print a cross reference table.
2589 Input_objects::print_cref(const Symbol_table
* symtab
, FILE* f
) const
2591 if (parameters
->options().cref() && this->cref_
!= NULL
)
2592 this->cref_
->print_cref(symtab
, f
);
2595 // Relocate_info methods.
2597 // Return a string describing the location of a relocation. This is
2598 // only used in error messages.
2600 template<int size
, bool big_endian
>
2602 Relocate_info
<size
, big_endian
>::location(size_t, off_t offset
) const
2604 // See if we can get line-number information from debugging sections.
2605 std::string filename
;
2606 std::string file_and_lineno
; // Better than filename-only, if available.
2608 Sized_dwarf_line_info
<size
, big_endian
> line_info(this->object
);
2609 // This will be "" if we failed to parse the debug info for any reason.
2610 file_and_lineno
= line_info
.addr2line(this->data_shndx
, offset
, NULL
);
2612 std::string
ret(this->object
->name());
2614 Symbol_location_info info
;
2615 if (this->object
->get_symbol_location_info(this->data_shndx
, offset
, &info
))
2617 ret
+= " in function ";
2618 ret
+= info
.enclosing_symbol_name
;
2620 filename
= info
.source_file
;
2623 if (!file_and_lineno
.empty())
2624 ret
+= file_and_lineno
;
2627 if (!filename
.empty())
2630 ret
+= this->object
->section_name(this->data_shndx
);
2632 // Offsets into sections have to be positive.
2633 snprintf(buf
, sizeof(buf
), "+0x%lx", static_cast<long>(offset
));
2640 } // End namespace gold.
2645 using namespace gold
;
2647 // Read an ELF file with the header and return the appropriate
2648 // instance of Object.
2650 template<int size
, bool big_endian
>
2652 make_elf_sized_object(const std::string
& name
, Input_file
* input_file
,
2653 off_t offset
, const elfcpp::Ehdr
<size
, big_endian
>& ehdr
,
2654 bool* punconfigured
)
2656 Target
* target
= select_target(ehdr
.get_e_machine(), size
, big_endian
,
2657 ehdr
.get_e_ident()[elfcpp::EI_OSABI
],
2658 ehdr
.get_e_ident()[elfcpp::EI_ABIVERSION
]);
2660 gold_fatal(_("%s: unsupported ELF machine number %d"),
2661 name
.c_str(), ehdr
.get_e_machine());
2663 if (!parameters
->target_valid())
2664 set_parameters_target(target
);
2665 else if (target
!= ¶meters
->target())
2667 if (punconfigured
!= NULL
)
2668 *punconfigured
= true;
2670 gold_error(_("%s: incompatible target"), name
.c_str());
2674 return target
->make_elf_object
<size
, big_endian
>(name
, input_file
, offset
,
2678 } // End anonymous namespace.
2683 // Return whether INPUT_FILE is an ELF object.
2686 is_elf_object(Input_file
* input_file
, off_t offset
,
2687 const unsigned char** start
, int* read_size
)
2689 off_t filesize
= input_file
->file().filesize();
2690 int want
= elfcpp::Elf_recognizer::max_header_size
;
2691 if (filesize
- offset
< want
)
2692 want
= filesize
- offset
;
2694 const unsigned char* p
= input_file
->file().get_view(offset
, 0, want
,
2699 return elfcpp::Elf_recognizer::is_elf_file(p
, want
);
2702 // Read an ELF file and return the appropriate instance of Object.
2705 make_elf_object(const std::string
& name
, Input_file
* input_file
, off_t offset
,
2706 const unsigned char* p
, section_offset_type bytes
,
2707 bool* punconfigured
)
2709 if (punconfigured
!= NULL
)
2710 *punconfigured
= false;
2713 bool big_endian
= false;
2715 if (!elfcpp::Elf_recognizer::is_valid_header(p
, bytes
, &size
,
2716 &big_endian
, &error
))
2718 gold_error(_("%s: %s"), name
.c_str(), error
.c_str());
2726 #ifdef HAVE_TARGET_32_BIG
2727 elfcpp::Ehdr
<32, true> ehdr(p
);
2728 return make_elf_sized_object
<32, true>(name
, input_file
,
2729 offset
, ehdr
, punconfigured
);
2731 if (punconfigured
!= NULL
)
2732 *punconfigured
= true;
2734 gold_error(_("%s: not configured to support "
2735 "32-bit big-endian object"),
2742 #ifdef HAVE_TARGET_32_LITTLE
2743 elfcpp::Ehdr
<32, false> ehdr(p
);
2744 return make_elf_sized_object
<32, false>(name
, input_file
,
2745 offset
, ehdr
, punconfigured
);
2747 if (punconfigured
!= NULL
)
2748 *punconfigured
= true;
2750 gold_error(_("%s: not configured to support "
2751 "32-bit little-endian object"),
2757 else if (size
== 64)
2761 #ifdef HAVE_TARGET_64_BIG
2762 elfcpp::Ehdr
<64, true> ehdr(p
);
2763 return make_elf_sized_object
<64, true>(name
, input_file
,
2764 offset
, ehdr
, punconfigured
);
2766 if (punconfigured
!= NULL
)
2767 *punconfigured
= true;
2769 gold_error(_("%s: not configured to support "
2770 "64-bit big-endian object"),
2777 #ifdef HAVE_TARGET_64_LITTLE
2778 elfcpp::Ehdr
<64, false> ehdr(p
);
2779 return make_elf_sized_object
<64, false>(name
, input_file
,
2780 offset
, ehdr
, punconfigured
);
2782 if (punconfigured
!= NULL
)
2783 *punconfigured
= true;
2785 gold_error(_("%s: not configured to support "
2786 "64-bit little-endian object"),
2796 // Instantiate the templates we need.
2798 #ifdef HAVE_TARGET_32_LITTLE
2801 Object::read_section_data
<32, false>(elfcpp::Elf_file
<32, false, Object
>*,
2802 Read_symbols_data
*);
2805 #ifdef HAVE_TARGET_32_BIG
2808 Object::read_section_data
<32, true>(elfcpp::Elf_file
<32, true, Object
>*,
2809 Read_symbols_data
*);
2812 #ifdef HAVE_TARGET_64_LITTLE
2815 Object::read_section_data
<64, false>(elfcpp::Elf_file
<64, false, Object
>*,
2816 Read_symbols_data
*);
2819 #ifdef HAVE_TARGET_64_BIG
2822 Object::read_section_data
<64, true>(elfcpp::Elf_file
<64, true, Object
>*,
2823 Read_symbols_data
*);
2826 #ifdef HAVE_TARGET_32_LITTLE
2828 class Sized_relobj
<32, false>;
2831 #ifdef HAVE_TARGET_32_BIG
2833 class Sized_relobj
<32, true>;
2836 #ifdef HAVE_TARGET_64_LITTLE
2838 class Sized_relobj
<64, false>;
2841 #ifdef HAVE_TARGET_64_BIG
2843 class Sized_relobj
<64, true>;
2846 #ifdef HAVE_TARGET_32_LITTLE
2848 struct Relocate_info
<32, false>;
2851 #ifdef HAVE_TARGET_32_BIG
2853 struct Relocate_info
<32, true>;
2856 #ifdef HAVE_TARGET_64_LITTLE
2858 struct Relocate_info
<64, false>;
2861 #ifdef HAVE_TARGET_64_BIG
2863 struct Relocate_info
<64, true>;
2866 #ifdef HAVE_TARGET_32_LITTLE
2869 Xindex::initialize_symtab_xindex
<32, false>(Object
*, unsigned int);
2873 Xindex::read_symtab_xindex
<32, false>(Object
*, unsigned int,
2874 const unsigned char*);
2877 #ifdef HAVE_TARGET_32_BIG
2880 Xindex::initialize_symtab_xindex
<32, true>(Object
*, unsigned int);
2884 Xindex::read_symtab_xindex
<32, true>(Object
*, unsigned int,
2885 const unsigned char*);
2888 #ifdef HAVE_TARGET_64_LITTLE
2891 Xindex::initialize_symtab_xindex
<64, false>(Object
*, unsigned int);
2895 Xindex::read_symtab_xindex
<64, false>(Object
*, unsigned int,
2896 const unsigned char*);
2899 #ifdef HAVE_TARGET_64_BIG
2902 Xindex::initialize_symtab_xindex
<64, true>(Object
*, unsigned int);
2906 Xindex::read_symtab_xindex
<64, true>(Object
*, unsigned int,
2907 const unsigned char*);
2910 } // End namespace gold.