1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright 2006, 2007 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.
30 #include "elfcpp_file.h"
37 class General_options
;
42 class Object_merge_map
;
44 template<typename Stringpool_char
>
45 class Stringpool_template
;
47 // Data to pass from read_symbols() to add_symbols().
49 struct Read_symbols_data
52 File_view
* section_headers
;
54 File_view
* section_names
;
55 // Size of section name data in bytes.
56 off_t section_names_size
;
59 // Size of symbol data in bytes.
61 // Offset of external symbols within symbol data. This structure
62 // sometimes contains only external symbols, in which case this will
63 // be zero. Sometimes it contains all symbols.
64 off_t external_symbols_offset
;
66 File_view
* symbol_names
;
67 // Size of symbol name data in bytes.
68 off_t symbol_names_size
;
70 // Version information. This is only used on dynamic objects.
71 // Version symbol data (from SHT_GNU_versym section).
74 // Version definition data (from SHT_GNU_verdef section).
77 unsigned int verdef_info
;
78 // Needed version data (from SHT_GNU_verneed section).
81 unsigned int verneed_info
;
84 // Information used to print error messages.
86 struct Symbol_location_info
88 std::string source_file
;
89 std::string enclosing_symbol_name
;
93 // Data about a single relocation section. This is read in
94 // read_relocs and processed in scan_relocs.
98 // Index of reloc section.
99 unsigned int reloc_shndx
;
100 // Index of section that relocs apply to.
101 unsigned int data_shndx
;
102 // Contents of reloc section.
104 // Reloc section type.
105 unsigned int sh_type
;
106 // Number of reloc entries.
109 Output_section
* output_section
;
110 // Whether this section has special handling for offsets.
111 bool needs_special_offset_handling
;
114 // Relocations in an object file. This is read in read_relocs and
115 // processed in scan_relocs.
117 struct Read_relocs_data
119 typedef std::vector
<Section_relocs
> Relocs_list
;
122 // The local symbols.
123 File_view
* local_symbols
;
126 // Object is an abstract base class which represents either a 32-bit
127 // or a 64-bit input object. This can be a regular object file
128 // (ET_REL) or a shared object (ET_DYN).
133 // NAME is the name of the object as we would report it to the user
134 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
135 // used to read the file. OFFSET is the offset within the input
136 // file--0 for a .o or .so file, something else for a .a file.
137 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
139 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
140 is_dynamic_(is_dynamic
), target_(NULL
)
146 // Return the name of the object as we would report it to the tuser.
149 { return this->name_
; }
151 // Get the offset into the file.
154 { return this->offset_
; }
156 // Return whether this is a dynamic object.
159 { return this->is_dynamic_
; }
161 // Return the target structure associated with this object.
164 { return this->target_
; }
166 // Lock the underlying file.
169 { this->input_file_
->file().lock(); }
171 // Unlock the underlying file.
174 { this->input_file_
->file().unlock(); }
176 // Return whether the underlying file is locked.
179 { return this->input_file_
->file().is_locked(); }
181 // Return the sized target structure associated with this object.
182 // This is like the target method but it returns a pointer of
183 // appropriate checked type.
184 template<int size
, bool big_endian
>
185 Sized_target
<size
, big_endian
>*
186 sized_target(ACCEPT_SIZE_ENDIAN_ONLY
);
188 // Get the number of sections.
191 { return this->shnum_
; }
193 // Return a view of the contents of a section. Set *PLEN to the
194 // size. CACHE is a hint as in File_read::get_view.
196 section_contents(unsigned int shndx
, off_t
* plen
, bool cache
);
198 // Return the name of a section given a section index. This is only
199 // used for error messages.
201 section_name(unsigned int shndx
)
202 { return this->do_section_name(shndx
); }
204 // Return the section flags given a section index.
206 section_flags(unsigned int shndx
)
207 { return this->do_section_flags(shndx
); }
209 // Return the section type given a section index.
211 section_type(unsigned int shndx
)
212 { return this->do_section_type(shndx
); }
214 // Return the section link field given a section index.
216 section_link(unsigned int shndx
)
217 { return this->do_section_link(shndx
); }
219 // Return the section info field given a section index.
221 section_info(unsigned int shndx
)
222 { return this->do_section_info(shndx
); }
224 // Read the symbol information.
226 read_symbols(Read_symbols_data
* sd
)
227 { return this->do_read_symbols(sd
); }
229 // Pass sections which should be included in the link to the Layout
230 // object, and record where the sections go in the output file.
232 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
233 { this->do_layout(symtab
, layout
, sd
); }
235 // Add symbol information to the global symbol table.
237 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
)
238 { this->do_add_symbols(symtab
, sd
); }
240 // Functions and types for the elfcpp::Elf_file interface. This
241 // permit us to use Object as the File template parameter for
244 // The View class is returned by view. It must support a single
245 // method, data(). This is trivial, because get_view does what we
250 View(const unsigned char* p
)
259 const unsigned char* p_
;
264 view(off_t file_offset
, off_t data_size
)
265 { return View(this->get_view(file_offset
, data_size
, true)); }
269 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
271 // A location in the file.
277 Location(off_t fo
, off_t ds
)
278 : file_offset(fo
), data_size(ds
)
282 // Get a View given a Location.
283 View
view(Location loc
)
284 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true)); }
287 // Read the symbols--implemented by child class.
289 do_read_symbols(Read_symbols_data
*) = 0;
291 // Lay out sections--implemented by child class.
293 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
295 // Add symbol information to the global symbol table--implemented by
298 do_add_symbols(Symbol_table
*, Read_symbols_data
*) = 0;
300 // Return the location of the contents of a section. Implemented by
303 do_section_contents(unsigned int shndx
) = 0;
305 // Get the name of a section--implemented by child class.
307 do_section_name(unsigned int shndx
) = 0;
309 // Get section flags--implemented by child class.
311 do_section_flags(unsigned int shndx
) = 0;
313 // Get section type--implemented by child class.
315 do_section_type(unsigned int shndx
) = 0;
317 // Get section link field--implemented by child class.
319 do_section_link(unsigned int shndx
) = 0;
321 // Get section info field--implemented by child class.
323 do_section_info(unsigned int shndx
) = 0;
328 { return this->input_file_
; }
330 // Get a view into the underlying file.
332 get_view(off_t start
, off_t size
, bool cache
)
334 return this->input_file_
->file().get_view(start
+ this->offset_
, size
,
338 // Get a lasting view into the underlying file.
340 get_lasting_view(off_t start
, off_t size
, bool cache
)
342 return this->input_file_
->file().get_lasting_view(start
+ this->offset_
,
346 // Read data from the underlying file.
348 read(off_t start
, off_t size
, void* p
)
349 { this->input_file_
->file().read(start
+ this->offset_
, size
, p
); }
353 set_target(int machine
, int size
, bool big_endian
, int osabi
,
356 // Set the number of sections.
359 { this->shnum_
= shnum
; }
361 // Functions used by both Sized_relobj and Sized_dynobj.
363 // Read the section data into a Read_symbols_data object.
364 template<int size
, bool big_endian
>
366 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
369 // If NAME is the name of a special .gnu.warning section, arrange
370 // for the warning to be issued. SHNDX is the section index.
371 // Return whether it is a warning section.
373 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
377 // This class may not be copied.
378 Object(const Object
&);
379 Object
& operator=(const Object
&);
381 // Name of object as printed to user.
383 // For reading the file.
384 Input_file
* input_file_
;
385 // Offset within the file--0 for an object file, non-0 for an
388 // Number of input sections.
390 // Whether this is a dynamic object.
392 // Target functions--may be NULL if the target is not known.
396 // Implement sized_target inline for efficiency. This approach breaks
397 // static type checking, but is made safe using asserts.
399 template<int size
, bool big_endian
>
400 inline Sized_target
<size
, big_endian
>*
401 Object::sized_target(ACCEPT_SIZE_ENDIAN_ONLY
)
403 gold_assert(this->target_
->get_size() == size
);
404 gold_assert(this->target_
->is_big_endian() ? big_endian
: !big_endian
);
405 return static_cast<Sized_target
<size
, big_endian
>*>(this->target_
);
408 // A regular object (ET_REL). This is an abstract base class itself.
409 // The implementation is the template class Sized_relobj.
411 class Relobj
: public Object
414 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
415 : Object(name
, input_file
, false, offset
),
417 object_merge_map_(NULL
),
418 relocs_must_follow_section_writes_(false)
423 read_relocs(Read_relocs_data
* rd
)
424 { return this->do_read_relocs(rd
); }
426 // Scan the relocs and adjust the symbol table.
428 scan_relocs(const General_options
& options
, Symbol_table
* symtab
,
429 Layout
* layout
, Read_relocs_data
* rd
)
430 { return this->do_scan_relocs(options
, symtab
, layout
, rd
); }
432 // Initial local symbol processing: set the offset where local
433 // symbol information will be stored; add local symbol names to
434 // *POOL; return the new local symbol index.
436 finalize_local_symbols(unsigned int index
, off_t off
,
437 Stringpool_template
<char>* pool
)
438 { return this->do_finalize_local_symbols(index
, off
, pool
); }
440 // Relocate the input sections and write out the local symbols.
442 relocate(const General_options
& options
, const Symbol_table
* symtab
,
443 const Layout
* layout
, Output_file
* of
)
444 { return this->do_relocate(options
, symtab
, layout
, of
); }
446 // Return whether an input section is being included in the link.
448 is_section_included(unsigned int shndx
) const
450 gold_assert(shndx
< this->map_to_output_
.size());
451 return this->map_to_output_
[shndx
].output_section
!= NULL
;
454 // Return whether an input section requires special
455 // handling--whether it is not simply mapped from the input file to
458 is_section_specially_mapped(unsigned int shndx
) const
460 gold_assert(shndx
< this->map_to_output_
.size());
461 return (this->map_to_output_
[shndx
].output_section
!= NULL
462 && this->map_to_output_
[shndx
].offset
== -1);
465 // Given a section index, return the corresponding Output_section
466 // (which will be NULL if the section is not included in the link)
467 // and set *POFF to the offset within that section. *POFF will be
468 // set to -1 if the section requires special handling.
469 inline Output_section
*
470 output_section(unsigned int shndx
, off_t
* poff
) const;
472 // Set the offset of an input section within its output section.
474 set_section_offset(unsigned int shndx
, off_t off
)
476 gold_assert(shndx
< this->map_to_output_
.size());
477 this->map_to_output_
[shndx
].offset
= off
;
480 // Return true if we need to wait for output sections to be written
481 // before we can apply relocations. This is true if the object has
482 // any relocations for sections which require special handling, such
483 // as the exception frame section.
485 relocs_must_follow_section_writes()
486 { return this->relocs_must_follow_section_writes_
; }
488 // Return the object merge map.
491 { return this->object_merge_map_
; }
493 // Set the object merge map.
495 set_merge_map(Object_merge_map
* object_merge_map
)
497 gold_assert(this->object_merge_map_
== NULL
);
498 this->object_merge_map_
= object_merge_map
;
502 // What we need to know to map an input section to an output
503 // section. We keep an array of these, one for each input section,
504 // indexed by the input section number.
507 // The output section. This is NULL if the input section is to be
509 Output_section
* output_section
;
510 // The offset within the output section. This is -1 if the
511 // section requires special handling.
515 // Read the relocs--implemented by child class.
517 do_read_relocs(Read_relocs_data
*) = 0;
519 // Scan the relocs--implemented by child class.
521 do_scan_relocs(const General_options
&, Symbol_table
*, Layout
*,
522 Read_relocs_data
*) = 0;
524 // Finalize local symbols--implemented by child class.
526 do_finalize_local_symbols(unsigned int, off_t
,
527 Stringpool_template
<char>*) = 0;
529 // Relocate the input sections and write out the local
530 // symbols--implemented by child class.
532 do_relocate(const General_options
& options
, const Symbol_table
* symtab
,
533 const Layout
*, Output_file
* of
) = 0;
535 // Return the vector mapping input sections to output sections.
536 std::vector
<Map_to_output
>&
538 { return this->map_to_output_
; }
540 const std::vector
<Map_to_output
>&
541 map_to_output() const
542 { return this->map_to_output_
; }
544 // Record that we must wait for the output sections to be written
545 // before applying relocations.
547 set_relocs_must_follow_section_writes()
548 { this->relocs_must_follow_section_writes_
= true; }
551 // Mapping from input sections to output section.
552 std::vector
<Map_to_output
> map_to_output_
;
553 // Mappings for merge sections. This is managed by the code in the
555 Object_merge_map
* object_merge_map_
;
556 // Whether we need to wait for output sections to be written before
557 // we can apply relocations.
558 bool relocs_must_follow_section_writes_
;
561 // Implement Object::output_section inline for efficiency.
562 inline Output_section
*
563 Relobj::output_section(unsigned int shndx
, off_t
* poff
) const
565 gold_assert(shndx
< this->map_to_output_
.size());
566 const Map_to_output
& mo(this->map_to_output_
[shndx
]);
568 return mo
.output_section
;
571 // This POD class is holds the value of a symbol. This is used for
572 // local symbols, and for all symbols during relocation processing.
573 // For special sections, such as SHF_MERGE sections, this calls a
574 // function to get the final symbol value.
580 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
583 : output_symtab_index_(0), input_shndx_(0), is_section_symbol_(false),
584 needs_output_address_(false), value_(0)
587 // Get the value of this symbol. OBJECT is the object in which this
588 // symbol is defined, and ADDEND is an addend to add to the value.
589 template<bool big_endian
>
591 value(const Sized_relobj
<size
, big_endian
>* object
, Value addend
) const
593 if (!this->needs_output_address_
)
594 return this->value_
+ addend
;
595 return object
->local_value(this->input_shndx_
, this->value_
,
596 this->is_section_symbol_
, addend
);
599 // Set the value of this symbol in the output symbol table.
601 set_output_value(Value value
)
603 this->value_
= value
;
604 this->needs_output_address_
= false;
607 // If this symbol is mapped to an output section which requires
608 // special handling to determine the output value, we store the
609 // value of the symbol in the input file. This is used for
610 // SHF_MERGE sections.
612 set_input_value(Value value
)
614 this->value_
= value
;
615 this->needs_output_address_
= true;
618 // Return whether this symbol should go into the output symbol
621 needs_output_symtab_entry() const
623 gold_assert(this->output_symtab_index_
!= 0);
624 return this->output_symtab_index_
!= -1U;
627 // Return the index in the output symbol table.
629 output_symtab_index() const
631 gold_assert(this->output_symtab_index_
!= 0);
632 return this->output_symtab_index_
;
635 // Set the index in the output symbol table.
637 set_output_symtab_index(unsigned int i
)
639 gold_assert(this->output_symtab_index_
== 0);
640 this->output_symtab_index_
= i
;
643 // Record that this symbol should not go into the output symbol
646 set_no_output_symtab_entry()
648 gold_assert(this->output_symtab_index_
== 0);
649 this->output_symtab_index_
= -1U;
652 // Set the index of the input section in the input file.
654 set_input_shndx(unsigned int i
)
656 this->input_shndx_
= i
;
657 gold_assert(this->input_shndx_
== i
);
660 // Record that this is a section symbol.
662 set_is_section_symbol()
663 { this->is_section_symbol_
= true; }
666 // The index of this local symbol in the output symbol table. This
667 // will be -1 if the symbol should not go into the symbol table.
668 unsigned int output_symtab_index_
;
669 // The section index in the input file in which this symbol is
671 unsigned int input_shndx_
: 30;
672 // Whether this is a STT_SECTION symbol.
673 bool is_section_symbol_
: 1;
674 // Whether getting the value of this symbol requires calling an
675 // Output_section method. For example, this will be true of a
676 // symbol in a SHF_MERGE section.
677 bool needs_output_address_
: 1;
678 // The value of the symbol. If !needs_output_address_, this is the
679 // value in the output file. If needs_output_address_, this is the
680 // value in the input file.
684 // A regular object file. This is size and endian specific.
686 template<int size
, bool big_endian
>
687 class Sized_relobj
: public Relobj
690 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
691 typedef std::vector
<Symbol
*> Symbols
;
692 typedef std::vector
<Symbol_value
<size
> > Local_values
;
694 Sized_relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
,
695 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
699 // Set up the object file based on the ELF header.
701 setup(const typename
elfcpp::Ehdr
<size
, big_endian
>&);
703 // Return the number of local symbols.
705 local_symbol_count() const
706 { return this->local_symbol_count_
; }
708 // If SYM is the index of a global symbol in the object file's
709 // symbol table, return the Symbol object. Otherwise, return NULL.
711 global_symbol(unsigned int sym
) const
713 if (sym
>= this->local_symbol_count_
)
715 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
716 return this->symbols_
[sym
- this->local_symbol_count_
];
721 // Return the section index of symbol SYM. Set *VALUE to its value
722 // in the object file. Note that for a symbol which is not defined
723 // in this object file, this will set *VALUE to 0 and return
724 // SHN_UNDEF; it will not return the final value of the symbol in
727 symbol_section_and_value(unsigned int sym
, Address
* value
);
729 // Return a pointer to the Symbol_value structure which holds the
730 // value of a local symbol.
731 const Symbol_value
<size
>*
732 local_symbol(unsigned int sym
) const
734 gold_assert(sym
< this->local_values_
.size());
735 return &this->local_values_
[sym
];
738 // Return the index of local symbol SYM in the ordinary symbol
739 // table. A value of -1U means that the symbol is not being output.
741 symtab_index(unsigned int sym
) const
743 gold_assert(sym
< this->local_values_
.size());
744 return this->local_values_
[sym
].output_symtab_index();
747 // Return the appropriate Sized_target structure.
748 Sized_target
<size
, big_endian
>*
751 return this->Object::sized_target
752 SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
753 SELECT_SIZE_ENDIAN_ONLY(size
, big_endian
));
756 // Return the value of the local symbol symndx.
758 local_symbol_value(unsigned int symndx
) const;
760 // Return the value of a local symbol defined in input section
761 // SHNDX, with value VALUE, adding addend ADDEND. IS_SECTION_SYMBOL
762 // indicates whether the symbol is a section symbol. This handles
763 // SHF_MERGE sections.
765 local_value(unsigned int shndx
, Address value
, bool is_section_symbol
,
766 Address addend
) const;
768 // Return whether the local symbol SYMNDX has a GOT offset.
769 // For TLS symbols, the GOT entry will hold its tp-relative offset.
771 local_has_got_offset(unsigned int symndx
) const
773 return (this->local_got_offsets_
.find(symndx
)
774 != this->local_got_offsets_
.end());
777 // Return the GOT offset of the local symbol SYMNDX.
779 local_got_offset(unsigned int symndx
) const
781 Local_got_offsets::const_iterator p
=
782 this->local_got_offsets_
.find(symndx
);
783 gold_assert(p
!= this->local_got_offsets_
.end());
787 // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
789 set_local_got_offset(unsigned int symndx
, unsigned int got_offset
)
791 std::pair
<Local_got_offsets::iterator
, bool> ins
=
792 this->local_got_offsets_
.insert(std::make_pair(symndx
, got_offset
));
793 gold_assert(ins
.second
);
796 // Return whether the local TLS symbol SYMNDX has a GOT offset.
797 // The GOT entry at this offset will contain a module index. If
798 // NEED_PAIR is true, a second entry immediately following the first
799 // will contain the dtv-relative offset.
801 local_has_tls_got_offset(unsigned int symndx
, bool need_pair
) const
803 typename
Local_tls_got_offsets::const_iterator p
=
804 this->local_tls_got_offsets_
.find(symndx
);
805 if (p
== this->local_tls_got_offsets_
.end()
806 || (need_pair
&& !p
->second
.have_pair_
))
811 // Return the offset of the GOT entry for the local TLS symbol SYMNDX.
812 // If NEED_PAIR is true, we need the offset of a pair of GOT entries;
813 // otherwise we need the offset of the GOT entry for the module index.
815 local_tls_got_offset(unsigned int symndx
, bool need_pair
) const
817 typename
Local_tls_got_offsets::const_iterator p
=
818 this->local_tls_got_offsets_
.find(symndx
);
819 gold_assert(p
!= this->local_tls_got_offsets_
.end());
820 gold_assert(!need_pair
|| p
->second
.have_pair_
);
821 return p
->second
.got_offset_
;
824 // Set the offset of the GOT entry for the local TLS symbol SYMNDX
825 // to GOT_OFFSET. If HAVE_PAIR is true, we have a pair of GOT entries;
826 // otherwise, we have just a single entry for the module index.
828 set_local_tls_got_offset(unsigned int symndx
, unsigned int got_offset
,
831 typename
Local_tls_got_offsets::iterator p
=
832 this->local_tls_got_offsets_
.find(symndx
);
833 if (p
!= this->local_tls_got_offsets_
.end())
835 // An entry already existed for this symbol. This can happen
836 // if we see a relocation asking for the module index before
837 // a relocation asking for the pair. In that case, the original
838 // GOT entry will remain, but won't get used by any further
840 p
->second
.got_offset_
= got_offset
;
841 gold_assert(have_pair
);
842 p
->second
.have_pair_
= true;
846 std::pair
<typename
Local_tls_got_offsets::iterator
, bool> ins
=
847 this->local_tls_got_offsets_
.insert(
848 std::make_pair(symndx
, Tls_got_entry(got_offset
, have_pair
)));
849 gold_assert(ins
.second
);
853 // Return the name of the symbol that spans the given offset in the
854 // specified section in this object. This is used only for error
855 // messages and is not particularly efficient.
857 get_symbol_location_info(unsigned int shndx
, off_t offset
,
858 Symbol_location_info
* info
);
862 do_read_symbols(Read_symbols_data
*);
864 // Lay out the input sections.
866 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
868 // Add the symbols to the symbol table.
870 do_add_symbols(Symbol_table
*, Read_symbols_data
*);
874 do_read_relocs(Read_relocs_data
*);
876 // Scan the relocs and adjust the symbol table.
878 do_scan_relocs(const General_options
&, Symbol_table
*, Layout
*,
881 // Finalize the local symbols.
883 do_finalize_local_symbols(unsigned int, off_t
,
884 Stringpool_template
<char>*);
886 // Relocate the input sections and write out the local symbols.
888 do_relocate(const General_options
& options
, const Symbol_table
* symtab
,
889 const Layout
*, Output_file
* of
);
891 // Get the name of a section.
893 do_section_name(unsigned int shndx
)
894 { return this->elf_file_
.section_name(shndx
); }
896 // Return the location of the contents of a section.
898 do_section_contents(unsigned int shndx
)
899 { return this->elf_file_
.section_contents(shndx
); }
901 // Return section flags.
903 do_section_flags(unsigned int shndx
)
904 { return this->elf_file_
.section_flags(shndx
); }
906 // Return section type.
908 do_section_type(unsigned int shndx
)
909 { return this->elf_file_
.section_type(shndx
); }
911 // Return the section link field.
913 do_section_link(unsigned int shndx
)
914 { return this->elf_file_
.section_link(shndx
); }
916 // Return the section info field.
918 do_section_info(unsigned int shndx
)
919 { return this->elf_file_
.section_info(shndx
); }
923 typedef Sized_relobj
<size
, big_endian
> This
;
924 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
925 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
926 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
927 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
929 // Find the SHT_SYMTAB section, given the section headers.
931 find_symtab(const unsigned char* pshdrs
);
933 // Return whether SHDR has the right flags for a GNU style exception
936 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
938 // Return whether there is a section named .eh_frame which might be
939 // a GNU style exception frame section.
941 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
942 off_t names_size
) const;
944 // Whether to include a section group in the link.
946 include_section_group(Layout
*, unsigned int,
947 const elfcpp::Shdr
<size
, big_endian
>&,
950 // Whether to include a linkonce section in the link.
952 include_linkonce_section(Layout
*, const char*,
953 const elfcpp::Shdr
<size
, big_endian
>&);
955 // Views and sizes when relocating.
959 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
962 bool is_input_output_view
;
965 typedef std::vector
<View_size
> Views
;
967 // Write section data to the output file. Record the views and
968 // sizes in VIEWS for use when relocating.
970 write_sections(const unsigned char* pshdrs
, Output_file
*, Views
*);
972 // Relocate the sections in the output file.
974 relocate_sections(const General_options
& options
, const Symbol_table
*,
975 const Layout
*, const unsigned char* pshdrs
, Views
*);
977 // Write out the local symbols.
979 write_local_symbols(Output_file
*,
980 const Stringpool_template
<char>*);
982 // The GOT offsets of local symbols. This map also stores GOT offsets
983 // for tp-relative offsets for TLS symbols.
984 typedef Unordered_map
<unsigned int, unsigned int> Local_got_offsets
;
986 // The TLS GOT offsets of local symbols. The map stores the offsets
987 // for either a single GOT entry that holds the module index of a TLS
988 // symbol, or a pair of GOT entries containing the module index and
989 // dtv-relative offset.
992 Tls_got_entry(int got_offset
, bool have_pair
)
993 : got_offset_(got_offset
),
994 have_pair_(have_pair
)
999 typedef Unordered_map
<unsigned int, Tls_got_entry
> Local_tls_got_offsets
;
1001 // General access to the ELF file.
1002 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
1003 // Index of SHT_SYMTAB section.
1004 unsigned int symtab_shndx_
;
1005 // The number of local symbols.
1006 unsigned int local_symbol_count_
;
1007 // The number of local symbols which go into the output file.
1008 unsigned int output_local_symbol_count_
;
1009 // The entries in the symbol table for the external symbols.
1011 // File offset for local symbols.
1012 off_t local_symbol_offset_
;
1013 // Values of local symbols.
1014 Local_values local_values_
;
1015 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1016 // for TLS symbols, indexed by symbol number.
1017 Local_got_offsets local_got_offsets_
;
1018 // GOT offsets for local TLS symbols, indexed by symbol number
1019 // and GOT entry type.
1020 Local_tls_got_offsets local_tls_got_offsets_
;
1021 // Whether this object has a GNU style .eh_frame section.
1025 // A class to manage the list of all objects.
1031 : relobj_list_(), dynobj_list_(), target_(NULL
), sonames_(),
1032 system_library_directory_()
1035 // The type of the list of input relocateable objects.
1036 typedef std::vector
<Relobj
*> Relobj_list
;
1037 typedef Relobj_list::const_iterator Relobj_iterator
;
1039 // The type of the list of input dynamic objects.
1040 typedef std::vector
<Dynobj
*> Dynobj_list
;
1041 typedef Dynobj_list::const_iterator Dynobj_iterator
;
1043 // Add an object to the list. Return true if all is well, or false
1044 // if this object should be ignored.
1046 add_object(Object
*);
1048 // Get the target we should use for the output file.
1051 { return this->target_
; }
1053 // For each dynamic object, check whether we've seen all of its
1054 // explicit dependencies.
1056 check_dynamic_dependencies() const;
1058 // Return whether an object was found in the system library
1061 found_in_system_library_directory(const Object
*) const;
1063 // Iterate over all regular objects.
1066 relobj_begin() const
1067 { return this->relobj_list_
.begin(); }
1071 { return this->relobj_list_
.end(); }
1073 // Iterate over all dynamic objects.
1076 dynobj_begin() const
1077 { return this->dynobj_list_
.begin(); }
1081 { return this->dynobj_list_
.end(); }
1083 // Return whether we have seen any dynamic objects.
1086 { return !this->dynobj_list_
.empty(); }
1088 // Return the number of input objects.
1090 number_of_input_objects() const
1091 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
1094 Input_objects(const Input_objects
&);
1095 Input_objects
& operator=(const Input_objects
&);
1097 // The list of ordinary objects included in the link.
1098 Relobj_list relobj_list_
;
1099 // The list of dynamic objects included in the link.
1100 Dynobj_list dynobj_list_
;
1103 // SONAMEs that we have seen.
1104 Unordered_set
<std::string
> sonames_
;
1105 // The directory in which we find the libc.so.
1106 std::string system_library_directory_
;
1109 // Some of the information we pass to the relocation routines. We
1110 // group this together to avoid passing a dozen different arguments.
1112 template<int size
, bool big_endian
>
1113 struct Relocate_info
1115 // Command line options.
1116 const General_options
* options
;
1118 const Symbol_table
* symtab
;
1120 const Layout
* layout
;
1121 // Object being relocated.
1122 Sized_relobj
<size
, big_endian
>* object
;
1123 // Section index of relocation section.
1124 unsigned int reloc_shndx
;
1125 // Section index of section being relocated.
1126 unsigned int data_shndx
;
1128 // Return a string showing the location of a relocation. This is
1129 // only used for error messages.
1131 location(size_t relnum
, off_t reloffset
) const;
1134 // Return an Object appropriate for the input file. P is BYTES long,
1135 // and holds the ELF header.
1138 make_elf_object(const std::string
& name
, Input_file
*,
1139 off_t offset
, const unsigned char* p
,
1142 } // end namespace gold
1144 #endif // !defined(GOLD_OBJECT_H)