1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright (C) 2006-2020 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"
38 class General_options
;
45 class Output_section_data
;
47 class Output_symtab_xindex
;
50 class Object_merge_map
;
51 class Relocatable_relocs
;
54 template<typename Stringpool_char
>
55 class Stringpool_template
;
57 // Data to pass from read_symbols() to add_symbols().
59 struct Read_symbols_data
62 : section_headers(NULL
), section_names(NULL
), symbols(NULL
),
63 symbol_names(NULL
), versym(NULL
), verdef(NULL
), verneed(NULL
)
69 File_view
* section_headers
;
71 File_view
* section_names
;
72 // Size of section name data in bytes.
73 section_size_type section_names_size
;
76 // Size of symbol data in bytes.
77 section_size_type symbols_size
;
78 // Offset of external symbols within symbol data. This structure
79 // sometimes contains only external symbols, in which case this will
80 // be zero. Sometimes it contains all symbols.
81 section_offset_type external_symbols_offset
;
83 File_view
* symbol_names
;
84 // Size of symbol name data in bytes.
85 section_size_type symbol_names_size
;
87 // Version information. This is only used on dynamic objects.
88 // Version symbol data (from SHT_GNU_versym section).
90 section_size_type versym_size
;
91 // Version definition data (from SHT_GNU_verdef section).
93 section_size_type verdef_size
;
94 unsigned int verdef_info
;
95 // Needed version data (from SHT_GNU_verneed section).
97 section_size_type verneed_size
;
98 unsigned int verneed_info
;
101 // Information used to print error messages.
103 struct Symbol_location_info
105 std::string source_file
;
106 std::string enclosing_symbol_name
;
107 elfcpp::STT enclosing_symbol_type
;
110 // Data about a single relocation section. This is read in
111 // read_relocs and processed in scan_relocs.
113 struct Section_relocs
120 { delete this->contents
; }
122 // Index of reloc section.
123 unsigned int reloc_shndx
;
124 // Index of section that relocs apply to.
125 unsigned int data_shndx
;
126 // Contents of reloc section.
128 // Reloc section type.
129 unsigned int sh_type
;
130 // Number of reloc entries.
133 Output_section
* output_section
;
134 // Whether this section has special handling for offsets.
135 bool needs_special_offset_handling
;
136 // Whether the data section is allocated (has the SHF_ALLOC flag set).
137 bool is_data_section_allocated
;
140 // Relocations in an object file. This is read in read_relocs and
141 // processed in scan_relocs.
143 struct Read_relocs_data
146 : local_symbols(NULL
)
150 { delete this->local_symbols
; }
152 typedef std::vector
<Section_relocs
> Relocs_list
;
155 // The local symbols.
156 File_view
* local_symbols
;
159 // The Xindex class manages section indexes for objects with more than
165 Xindex(int large_shndx_offset
)
166 : large_shndx_offset_(large_shndx_offset
), symtab_xindex_()
169 // Initialize the symtab_xindex_ array, given the object and the
170 // section index of the symbol table to use.
171 template<int size
, bool big_endian
>
173 initialize_symtab_xindex(Object
*, unsigned int symtab_shndx
);
175 // Read in the symtab_xindex_ array, given its section index.
176 // PSHDRS may optionally point to the section headers.
177 template<int size
, bool big_endian
>
179 read_symtab_xindex(Object
*, unsigned int xindex_shndx
,
180 const unsigned char* pshdrs
);
182 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
183 // real section index.
185 sym_xindex_to_shndx(Object
* object
, unsigned int symndx
);
188 // The type of the array giving the real section index for symbols
189 // whose st_shndx field holds SHN_XINDEX.
190 typedef std::vector
<unsigned int> Symtab_xindex
;
192 // Adjust a section index if necessary. This should only be called
193 // for ordinary section indexes.
195 adjust_shndx(unsigned int shndx
)
197 if (shndx
>= elfcpp::SHN_LORESERVE
)
198 shndx
+= this->large_shndx_offset_
;
202 // Adjust to apply to large section indexes.
203 int large_shndx_offset_
;
204 // The data from the SHT_SYMTAB_SHNDX section.
205 Symtab_xindex symtab_xindex_
;
208 // A GOT offset list. A symbol may have more than one GOT offset
209 // (e.g., when mixing modules compiled with two different TLS models),
210 // but will usually have at most one. GOT_TYPE identifies the type of
211 // GOT entry; its values are specific to each target.
213 class Got_offset_list
217 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
220 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
221 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
226 if (this->got_next_
!= NULL
)
228 delete this->got_next_
;
229 this->got_next_
= NULL
;
233 // Initialize the fields to their default values.
237 this->got_type_
= -1U;
238 this->got_offset_
= 0;
239 this->got_next_
= NULL
;
242 // Set the offset for the GOT entry of type GOT_TYPE.
244 set_offset(unsigned int got_type
, unsigned int got_offset
)
246 if (this->got_type_
== -1U)
248 this->got_type_
= got_type
;
249 this->got_offset_
= got_offset
;
253 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
255 if (g
->got_type_
== got_type
)
257 g
->got_offset_
= got_offset
;
261 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
262 g
->got_next_
= this->got_next_
;
267 // Return the offset for a GOT entry of type GOT_TYPE.
269 get_offset(unsigned int got_type
) const
271 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
273 if (g
->got_type_
== got_type
)
274 return g
->got_offset_
;
279 // Return a pointer to the list, or NULL if the list is empty.
280 const Got_offset_list
*
283 if (this->got_type_
== -1U)
288 // Abstract visitor class for iterating over GOT offsets.
300 visit(unsigned int, unsigned int) = 0;
303 // Loop over all GOT offset entries, calling a visitor class V for each.
305 for_all_got_offsets(Visitor
* v
) const
307 if (this->got_type_
== -1U)
309 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
310 v
->visit(g
->got_type_
, g
->got_offset_
);
314 unsigned int got_type_
;
315 unsigned int got_offset_
;
316 Got_offset_list
* got_next_
;
319 // The Local_got_entry_key used to index the GOT offsets for local
320 // non-TLS symbols, and tp-relative offsets for TLS symbols.
322 class Local_got_entry_key
325 Local_got_entry_key(unsigned int symndx
, uint64_t addend
)
326 : symndx_(symndx
), addend_(addend
)
329 // Whether this equals to another Local_got_entry_key.
331 eq(const Local_got_entry_key
& key
) const
333 return (this->symndx_
== key
.symndx_
&& this->addend_
== key
.addend_
);
336 // Compute a hash value for this using 64-bit FNV-1a hash.
340 uint64_t h
= 14695981039346656037ULL; // FNV offset basis.
341 uint64_t prime
= 1099511628211ULL;
342 h
= (h
^ static_cast<uint64_t>(this->symndx_
)) * prime
;
343 h
= (h
^ static_cast<uint64_t>(this->addend_
)) * prime
;
347 // Functors for associative containers.
351 operator()(const Local_got_entry_key
& key1
,
352 const Local_got_entry_key
& key2
) const
353 { return key1
.eq(key2
); }
359 operator()(const Local_got_entry_key
& key
) const
360 { return key
.hash_value(); }
364 // The local symbol index.
365 unsigned int symndx_
;
370 // Type for mapping section index to uncompressed size and contents.
372 struct Compressed_section_info
374 section_size_type size
;
375 elfcpp::Elf_Xword flag
;
377 const unsigned char* contents
;
379 typedef std::map
<unsigned int, Compressed_section_info
> Compressed_section_map
;
381 template<int size
, bool big_endian
>
382 Compressed_section_map
*
383 build_compressed_section_map(const unsigned char* pshdrs
, unsigned int shnum
,
384 const char* names
, section_size_type names_size
,
385 Object
* obj
, bool decompress_if_needed
);
387 // Osabi represents the EI_OSABI field from the ELF header.
389 template <int size
, bool big_endian
>
393 Osabi(const elfcpp::Ehdr
<size
, big_endian
>& ehdr
)
394 : ei_osabi_(static_cast<elfcpp::ELFOSABI
>(
395 ehdr
.get_e_ident()[elfcpp::EI_OSABI
]))
399 has_shf_retain(elfcpp::Elf_Xword sh_flags
) const
401 switch (this->ei_osabi_
)
403 case elfcpp::ELFOSABI_GNU
:
404 case elfcpp::ELFOSABI_FREEBSD
:
405 return (sh_flags
& elfcpp::SHF_GNU_RETAIN
) != 0;
413 ignored_sh_flags() const
415 switch (this->ei_osabi_
)
417 case elfcpp::ELFOSABI_GNU
:
418 case elfcpp::ELFOSABI_FREEBSD
:
419 return elfcpp::SHF_GNU_RETAIN
;
427 elfcpp::ELFOSABI ei_osabi_
;
430 // Object is an abstract base class which represents either a 32-bit
431 // or a 64-bit input object. This can be a regular object file
432 // (ET_REL) or a shared object (ET_DYN).
437 typedef std::vector
<Symbol
*> Symbols
;
439 // NAME is the name of the object as we would report it to the user
440 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
441 // used to read the file. OFFSET is the offset within the input
442 // file--0 for a .o or .so file, something else for a .a file.
443 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
445 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
446 is_dynamic_(is_dynamic
), is_needed_(false), uses_split_stack_(false),
447 has_no_split_stack_(false), no_export_(false),
448 is_in_system_directory_(false), as_needed_(false), xindex_(NULL
),
449 compressed_sections_(NULL
)
451 if (input_file
!= NULL
)
453 input_file
->file().add_object();
454 this->is_in_system_directory_
= input_file
->is_in_system_directory();
455 this->as_needed_
= input_file
->options().as_needed();
461 if (this->input_file_
!= NULL
)
462 this->input_file_
->file().remove_object();
465 // Return the name of the object as we would report it to the user.
468 { return this->name_
; }
470 // Get the offset into the file.
473 { return this->offset_
; }
475 // Return whether this is a dynamic object.
478 { return this->is_dynamic_
; }
480 // Return the word size of the object file.
481 virtual int elfsize() const = 0;
483 // Return TRUE if this is a big-endian object file.
484 virtual bool is_big_endian() const = 0;
486 // Return whether this object is needed--true if it is a dynamic
487 // object which defines some symbol referenced by a regular object.
488 // We keep the flag here rather than in Dynobj for convenience when
492 { return this->is_needed_
; }
494 // Record that this object is needed.
497 { this->is_needed_
= true; }
499 // Return whether this object was compiled with -fsplit-stack.
501 uses_split_stack() const
502 { return this->uses_split_stack_
; }
504 // Return whether this object contains any functions compiled with
505 // the no_split_stack attribute.
507 has_no_split_stack() const
508 { return this->has_no_split_stack_
; }
510 // Returns NULL for Objects that are not dynamic objects. This method
511 // is overridden in the Dynobj class.
514 { return this->do_dynobj(); }
516 // Returns NULL for Objects that are not plugin objects. This method
517 // is overridden in the Pluginobj class.
520 { return this->do_pluginobj(); }
522 // Get the file. We pass on const-ness.
526 gold_assert(this->input_file_
!= NULL
);
527 return this->input_file_
;
533 gold_assert(this->input_file_
!= NULL
);
534 return this->input_file_
;
537 // Lock the underlying file.
541 if (this->input_file_
!= NULL
)
542 this->input_file_
->file().lock(t
);
545 // Unlock the underlying file.
547 unlock(const Task
* t
)
549 if (this->input_file_
!= NULL
)
550 this->input_file()->file().unlock(t
);
553 // Return whether the underlying file is locked.
556 { return this->input_file_
!= NULL
&& this->input_file_
->file().is_locked(); }
558 // Return the token, so that the task can be queued.
562 if (this->input_file_
== NULL
)
564 return this->input_file()->file().token();
567 // Release the underlying file.
571 if (this->input_file_
!= NULL
)
572 this->input_file()->file().release();
575 // Return whether we should just read symbols from this file.
578 { return this->input_file()->just_symbols(); }
580 // Return whether this is an incremental object.
582 is_incremental() const
583 { return this->do_is_incremental(); }
585 // Return the last modified time of the file.
588 { return this->do_get_mtime(); }
590 // Get the number of sections.
593 { return this->shnum_
; }
595 // Return a view of the contents of a section. Set *PLEN to the
596 // size. CACHE is a hint as in File_read::get_view.
598 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
600 // Adjust a symbol's section index as needed. SYMNDX is the index
601 // of the symbol and SHNDX is the symbol's section from
602 // get_st_shndx. This returns the section index. It sets
603 // *IS_ORDINARY to indicate whether this is a normal section index,
604 // rather than a special code between SHN_LORESERVE and
607 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
609 if (shndx
< elfcpp::SHN_LORESERVE
)
611 else if (shndx
== elfcpp::SHN_XINDEX
)
613 if (this->xindex_
== NULL
)
614 this->xindex_
= this->do_initialize_xindex();
615 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
619 *is_ordinary
= false;
623 // Return the size of a section given a section index.
625 section_size(unsigned int shndx
)
626 { return this->do_section_size(shndx
); }
628 // Return the name of a section given a section index.
630 section_name(unsigned int shndx
) const
631 { return this->do_section_name(shndx
); }
633 // Return the section flags given a section index.
635 section_flags(unsigned int shndx
)
636 { return this->do_section_flags(shndx
); }
638 // Return the section entsize given a section index.
640 section_entsize(unsigned int shndx
)
641 { return this->do_section_entsize(shndx
); }
643 // Return the section address given a section index.
645 section_address(unsigned int shndx
)
646 { return this->do_section_address(shndx
); }
648 // Return the section type given a section index.
650 section_type(unsigned int shndx
)
651 { return this->do_section_type(shndx
); }
653 // Return the section link field given a section index.
655 section_link(unsigned int shndx
)
656 { return this->do_section_link(shndx
); }
658 // Return the section info field given a section index.
660 section_info(unsigned int shndx
)
661 { return this->do_section_info(shndx
); }
663 // Return the required section alignment given a section index.
665 section_addralign(unsigned int shndx
)
666 { return this->do_section_addralign(shndx
); }
668 // Return the output section given a section index.
670 output_section(unsigned int shndx
) const
671 { return this->do_output_section(shndx
); }
673 // Given a section index, return its address.
674 // The return value will be -1U if the section is specially mapped,
675 // such as a merge section.
677 output_section_address(unsigned int shndx
)
678 { return this->do_output_section_address(shndx
); }
680 // Given a section index, return the offset in the Output_section.
681 // The return value will be -1U if the section is specially mapped,
682 // such as a merge section.
684 output_section_offset(unsigned int shndx
) const
685 { return this->do_output_section_offset(shndx
); }
687 // Read the symbol information.
689 read_symbols(Read_symbols_data
* sd
)
690 { return this->do_read_symbols(sd
); }
692 // Pass sections which should be included in the link to the Layout
693 // object, and record where the sections go in the output file.
695 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
696 { this->do_layout(symtab
, layout
, sd
); }
698 // Add symbol information to the global symbol table.
700 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
701 { this->do_add_symbols(symtab
, sd
, layout
); }
703 // Add symbol information to the global symbol table.
704 Archive::Should_include
705 should_include_member(Symbol_table
* symtab
, Layout
* layout
,
706 Read_symbols_data
* sd
, std::string
* why
)
707 { return this->do_should_include_member(symtab
, layout
, sd
, why
); }
709 // Iterate over global symbols, calling a visitor class V for each.
711 for_all_global_symbols(Read_symbols_data
* sd
,
712 Library_base::Symbol_visitor_base
* v
)
713 { return this->do_for_all_global_symbols(sd
, v
); }
715 // Iterate over local symbols, calling a visitor class V for each GOT offset
716 // associated with a local symbol.
718 for_all_local_got_entries(Got_offset_list::Visitor
* v
) const
719 { this->do_for_all_local_got_entries(v
); }
721 // Functions and types for the elfcpp::Elf_file interface. This
722 // permit us to use Object as the File template parameter for
725 // The View class is returned by view. It must support a single
726 // method, data(). This is trivial, because get_view does what we
731 View(const unsigned char* p
)
740 const unsigned char* p_
;
745 view(off_t file_offset
, section_size_type data_size
)
746 { return View(this->get_view(file_offset
, data_size
, true, true)); }
750 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
752 // A location in the file.
758 Location(off_t fo
, section_size_type ds
)
759 : file_offset(fo
), data_size(ds
)
763 // Get a View given a Location.
764 View
view(Location loc
)
765 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
767 // Get a view into the underlying file.
769 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
771 return this->input_file()->file().get_view(this->offset_
, start
, size
,
775 // Get a lasting view into the underlying file.
777 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
780 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
781 size
, aligned
, cache
);
784 // Read data from the underlying file.
786 read(off_t start
, section_size_type size
, void* p
)
787 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
789 // Read multiple data from the underlying file.
791 read_multiple(const File_read::Read_multiple
& rm
)
792 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
794 // Stop caching views in the underlying file.
796 clear_view_cache_marks()
798 if (this->input_file_
!= NULL
)
799 this->input_file_
->file().clear_view_cache_marks();
802 // Get the number of global symbols defined by this object, and the
803 // number of the symbols whose final definition came from this
806 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
808 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
810 // Get the symbols defined in this object.
812 get_global_symbols() const
813 { return this->do_get_global_symbols(); }
815 // Set flag that this object was found in a system directory.
817 set_is_in_system_directory()
818 { this->is_in_system_directory_
= true; }
820 // Return whether this object was found in a system directory.
822 is_in_system_directory() const
823 { return this->is_in_system_directory_
; }
825 // Set flag that this object was linked with --as-needed.
828 { this->as_needed_
= true; }
830 // Clear flag that this object was linked with --as-needed.
833 { this->as_needed_
= false; }
835 // Return whether this object was linked with --as-needed.
838 { return this->as_needed_
; }
840 // Return whether we found this object by searching a directory.
843 { return this->input_file()->will_search_for(); }
847 { return this->no_export_
; }
850 set_no_export(bool value
)
851 { this->no_export_
= value
; }
854 section_is_compressed(unsigned int shndx
,
855 section_size_type
* uncompressed_size
,
856 elfcpp::Elf_Xword
* palign
= NULL
) const
858 if (this->compressed_sections_
== NULL
)
860 Compressed_section_map::const_iterator p
=
861 this->compressed_sections_
->find(shndx
);
862 if (p
!= this->compressed_sections_
->end())
864 if (uncompressed_size
!= NULL
)
865 *uncompressed_size
= p
->second
.size
;
867 *palign
= p
->second
.addralign
;
873 // Return a view of the decompressed contents of a section. Set *PLEN
874 // to the size. Set *IS_NEW to true if the contents need to be freed
877 decompressed_section_contents(unsigned int shndx
, section_size_type
* plen
,
878 bool* is_cached
, uint64_t* palign
= NULL
);
880 // Discard any buffers of decompressed sections. This is done
881 // at the end of the Add_symbols task.
883 discard_decompressed_sections();
885 // Return the index of the first incremental relocation for symbol SYMNDX.
887 get_incremental_reloc_base(unsigned int symndx
) const
888 { return this->do_get_incremental_reloc_base(symndx
); }
890 // Return the number of incremental relocations for symbol SYMNDX.
892 get_incremental_reloc_count(unsigned int symndx
) const
893 { return this->do_get_incremental_reloc_count(symndx
); }
895 // Return the output view for section SHNDX.
897 get_output_view(unsigned int shndx
, section_size_type
* plen
) const
898 { return this->do_get_output_view(shndx
, plen
); }
901 // Returns NULL for Objects that are not dynamic objects. This method
902 // is overridden in the Dynobj class.
907 // Returns NULL for Objects that are not plugin objects. This method
908 // is overridden in the Pluginobj class.
913 // Return TRUE if this is an incremental (unchanged) input file.
914 // We return FALSE by default; the incremental object classes
915 // override this method.
917 do_is_incremental() const
920 // Return the last modified time of the file. This method may be
921 // overridden for subclasses that don't use an actual file (e.g.,
922 // Incremental objects).
925 { return this->input_file()->file().get_mtime(); }
927 // Read the symbols--implemented by child class.
929 do_read_symbols(Read_symbols_data
*) = 0;
931 // Lay out sections--implemented by child class.
933 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
935 // Add symbol information to the global symbol table--implemented by
938 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
940 virtual Archive::Should_include
941 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
942 std::string
* why
) = 0;
944 // Iterate over global symbols, calling a visitor class V for each.
946 do_for_all_global_symbols(Read_symbols_data
* sd
,
947 Library_base::Symbol_visitor_base
* v
) = 0;
949 // Iterate over local symbols, calling a visitor class V for each GOT offset
950 // associated with a local symbol.
952 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const = 0;
954 // Return the location of the contents of a section. Implemented by
956 virtual const unsigned char*
957 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
960 // Get the size of a section--implemented by child class.
962 do_section_size(unsigned int shndx
) = 0;
964 // Get the name of a section--implemented by child class.
966 do_section_name(unsigned int shndx
) const = 0;
968 // Get section flags--implemented by child class.
970 do_section_flags(unsigned int shndx
) = 0;
972 // Get section entsize--implemented by child class.
974 do_section_entsize(unsigned int shndx
) = 0;
976 // Get section address--implemented by child class.
978 do_section_address(unsigned int shndx
) = 0;
980 // Get section type--implemented by child class.
982 do_section_type(unsigned int shndx
) = 0;
984 // Get section link field--implemented by child class.
986 do_section_link(unsigned int shndx
) = 0;
988 // Get section info field--implemented by child class.
990 do_section_info(unsigned int shndx
) = 0;
992 // Get section alignment--implemented by child class.
994 do_section_addralign(unsigned int shndx
) = 0;
996 // Return the output section given a section index--implemented
998 virtual Output_section
*
999 do_output_section(unsigned int) const
1000 { gold_unreachable(); }
1002 // Get the address of a section--implemented by child class.
1004 do_output_section_address(unsigned int)
1005 { gold_unreachable(); }
1007 // Get the offset of a section--implemented by child class.
1009 do_output_section_offset(unsigned int) const
1010 { gold_unreachable(); }
1012 // Return the Xindex structure to use.
1014 do_initialize_xindex() = 0;
1016 // Implement get_global_symbol_counts--implemented by child class.
1018 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
1020 virtual const Symbols
*
1021 do_get_global_symbols() const = 0;
1023 // Set the number of sections.
1025 set_shnum(int shnum
)
1026 { this->shnum_
= shnum
; }
1028 // Functions used by both Sized_relobj_file and Sized_dynobj.
1030 // Read the section data into a Read_symbols_data object.
1031 template<int size
, bool big_endian
>
1033 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
1034 Read_symbols_data
*);
1036 // Find the section header with the given NAME. If HDR is non-NULL
1037 // then it is a section header returned from a previous call to this
1038 // function and the next section header with the same name will be
1040 template<int size
, bool big_endian
>
1041 const unsigned char*
1042 find_shdr(const unsigned char* pshdrs
, const char* name
,
1043 const char* names
, section_size_type names_size
,
1044 const unsigned char* hdr
) const;
1046 // Let the child class initialize the xindex object directly.
1048 set_xindex(Xindex
* xindex
)
1050 gold_assert(this->xindex_
== NULL
);
1051 this->xindex_
= xindex
;
1054 // If NAME is the name of a special .gnu.warning section, arrange
1055 // for the warning to be issued. SHNDX is the section index.
1056 // Return whether it is a warning section.
1058 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
1061 // If NAME is the name of the special section which indicates that
1062 // this object was compiled with -fsplit-stack, mark it accordingly,
1063 // and return true. Otherwise return false.
1065 handle_split_stack_section(const char* name
);
1067 // Discard any buffers of decompressed sections. This is done
1068 // at the end of the Add_symbols task.
1070 do_discard_decompressed_sections()
1073 // Return the index of the first incremental relocation for symbol SYMNDX--
1074 // implemented by child class.
1075 virtual unsigned int
1076 do_get_incremental_reloc_base(unsigned int) const
1077 { gold_unreachable(); }
1079 // Return the number of incremental relocations for symbol SYMNDX--
1080 // implemented by child class.
1081 virtual unsigned int
1082 do_get_incremental_reloc_count(unsigned int) const
1083 { gold_unreachable(); }
1085 // Return the output view for a section.
1086 virtual unsigned char*
1087 do_get_output_view(unsigned int, section_size_type
*) const
1088 { gold_unreachable(); }
1091 set_compressed_sections(Compressed_section_map
* compressed_sections
)
1092 { this->compressed_sections_
= compressed_sections
; }
1094 Compressed_section_map
*
1095 compressed_sections()
1096 { return this->compressed_sections_
; }
1099 // This class may not be copied.
1100 Object(const Object
&);
1101 Object
& operator=(const Object
&);
1103 // Name of object as printed to user.
1105 // For reading the file.
1106 Input_file
* input_file_
;
1107 // Offset within the file--0 for an object file, non-0 for an
1110 // Number of input sections.
1111 unsigned int shnum_
;
1112 // Whether this is a dynamic object.
1113 bool is_dynamic_
: 1;
1114 // Whether this object is needed. This is only set for dynamic
1115 // objects, and means that the object defined a symbol which was
1116 // used by a reference from a regular object.
1117 bool is_needed_
: 1;
1118 // Whether this object was compiled with -fsplit-stack.
1119 bool uses_split_stack_
: 1;
1120 // Whether this object contains any functions compiled with the
1121 // no_split_stack attribute.
1122 bool has_no_split_stack_
: 1;
1123 // True if exclude this object from automatic symbol export.
1124 // This is used only for archive objects.
1125 bool no_export_
: 1;
1126 // True if the object was found in a system directory.
1127 bool is_in_system_directory_
: 1;
1128 // True if the object was linked with --as-needed.
1129 bool as_needed_
: 1;
1130 // Many sections for objects with more than SHN_LORESERVE sections.
1132 // For compressed debug sections, map section index to uncompressed size
1134 Compressed_section_map
* compressed_sections_
;
1137 // A regular object (ET_REL). This is an abstract base class itself.
1138 // The implementation is the template class Sized_relobj_file.
1140 class Relobj
: public Object
1143 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
1144 : Object(name
, input_file
, false, offset
),
1146 map_to_relocatable_relocs_(NULL
),
1147 object_merge_map_(NULL
),
1148 relocs_must_follow_section_writes_(false),
1150 reloc_counts_(NULL
),
1152 first_dyn_reloc_(0),
1156 // During garbage collection, the Read_symbols_data pass for
1157 // each object is stored as layout needs to be done after
1158 // reloc processing.
1161 { return this->sd_
; }
1163 // Decides which section names have to be included in the worklist
1166 is_section_name_included(const char* name
);
1169 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
1170 unsigned int section_header_size
);
1173 set_symbols_data(Symbols_data
* sd
)
1176 // During garbage collection, the Read_relocs pass for all objects
1177 // is done before scanning the relocs. In that case, this->rd_ is
1178 // used to store the information from Read_relocs for each object.
1179 // This data is also used to compute the list of relevant sections.
1182 { return this->rd_
; }
1185 set_relocs_data(Read_relocs_data
* rd
)
1189 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
1193 read_relocs(Read_relocs_data
* rd
)
1194 { return this->do_read_relocs(rd
); }
1196 // Process the relocs, during garbage collection only.
1198 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1199 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
1201 // Scan the relocs and adjust the symbol table.
1203 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1204 { return this->do_scan_relocs(symtab
, layout
, rd
); }
1206 // Return the value of the local symbol whose index is SYMNDX, plus
1207 // ADDEND. ADDEND is passed in so that we can correctly handle the
1208 // section symbol for a merge section.
1210 local_symbol_value(unsigned int symndx
, uint64_t addend
) const
1211 { return this->do_local_symbol_value(symndx
, addend
); }
1213 // Return the PLT offset for a local symbol. It is an error to call
1214 // this if it doesn't have one.
1216 local_plt_offset(unsigned int symndx
) const
1217 { return this->do_local_plt_offset(symndx
); }
1219 // Return whether the local symbol SYMNDX has a GOT offset of type
1222 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1223 { return this->do_local_has_got_offset(symndx
, got_type
, 0); }
1225 // Return whether the local symbol SYMNDX plus ADDEND has a GOT offset
1226 // of type GOT_TYPE.
1228 local_has_got_offset(unsigned int symndx
, unsigned int got_type
,
1229 uint64_t addend
) const
1230 { return this->do_local_has_got_offset(symndx
, got_type
, addend
); }
1232 // Return the GOT offset of type GOT_TYPE of the local symbol
1233 // SYMNDX. It is an error to call this if the symbol does not have
1234 // a GOT offset of the specified type.
1236 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1237 { return this->do_local_got_offset(symndx
, got_type
, 0); }
1239 // Return the GOT offset of type GOT_TYPE of the local symbol
1240 // SYMNDX plus ADDEND. It is an error to call this if the symbol
1241 // does not have a GOT offset of the specified type.
1243 local_got_offset(unsigned int symndx
, unsigned int got_type
,
1244 uint64_t addend
) const
1245 { return this->do_local_got_offset(symndx
, got_type
, addend
); }
1247 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1250 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1251 unsigned int got_offset
)
1252 { this->do_set_local_got_offset(symndx
, got_type
, got_offset
, 0); }
1254 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1255 // plus ADDEND to GOT_OFFSET.
1257 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1258 unsigned int got_offset
, uint64_t addend
)
1259 { this->do_set_local_got_offset(symndx
, got_type
, got_offset
, addend
); }
1261 // Return whether the local symbol SYMNDX is a TLS symbol.
1263 local_is_tls(unsigned int symndx
) const
1264 { return this->do_local_is_tls(symndx
); }
1266 // The number of local symbols in the input symbol table.
1267 virtual unsigned int
1268 local_symbol_count() const
1269 { return this->do_local_symbol_count(); }
1271 // The number of local symbols in the output symbol table.
1272 virtual unsigned int
1273 output_local_symbol_count() const
1274 { return this->do_output_local_symbol_count(); }
1276 // The file offset for local symbols in the output symbol table.
1278 local_symbol_offset() const
1279 { return this->do_local_symbol_offset(); }
1281 // Initial local symbol processing: count the number of local symbols
1282 // in the output symbol table and dynamic symbol table; add local symbol
1283 // names to *POOL and *DYNPOOL.
1285 count_local_symbols(Stringpool_template
<char>* pool
,
1286 Stringpool_template
<char>* dynpool
)
1287 { return this->do_count_local_symbols(pool
, dynpool
); }
1289 // Set the values of the local symbols, set the output symbol table
1290 // indexes for the local variables, and set the offset where local
1291 // symbol information will be stored. Returns the new local symbol index.
1293 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
1294 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
1296 // Set the output dynamic symbol table indexes for the local variables.
1298 set_local_dynsym_indexes(unsigned int index
)
1299 { return this->do_set_local_dynsym_indexes(index
); }
1301 // Set the offset where local dynamic symbol information will be stored.
1303 set_local_dynsym_offset(off_t off
)
1304 { return this->do_set_local_dynsym_offset(off
); }
1306 // Record a dynamic relocation against an input section from this object.
1308 add_dyn_reloc(unsigned int index
)
1310 if (this->dyn_reloc_count_
== 0)
1311 this->first_dyn_reloc_
= index
;
1312 ++this->dyn_reloc_count_
;
1315 // Return the index of the first dynamic relocation.
1317 first_dyn_reloc() const
1318 { return this->first_dyn_reloc_
; }
1320 // Return the count of dynamic relocations.
1322 dyn_reloc_count() const
1323 { return this->dyn_reloc_count_
; }
1325 // Relocate the input sections and write out the local symbols.
1327 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
1328 { return this->do_relocate(symtab
, layout
, of
); }
1330 // Return whether an input section is being included in the link.
1332 is_section_included(unsigned int shndx
) const
1334 gold_assert(shndx
< this->output_sections_
.size());
1335 return this->output_sections_
[shndx
] != NULL
;
1338 // The output section of the input section with index SHNDX.
1339 // This is only used currently to remove a section from the link in
1342 set_output_section(unsigned int shndx
, Output_section
* os
)
1344 gold_assert(shndx
< this->output_sections_
.size());
1345 this->output_sections_
[shndx
] = os
;
1348 // Set the offset of an input section within its output section.
1350 set_section_offset(unsigned int shndx
, uint64_t off
)
1351 { this->do_set_section_offset(shndx
, off
); }
1353 // Return true if we need to wait for output sections to be written
1354 // before we can apply relocations. This is true if the object has
1355 // any relocations for sections which require special handling, such
1356 // as the exception frame section.
1358 relocs_must_follow_section_writes() const
1359 { return this->relocs_must_follow_section_writes_
; }
1362 get_or_create_merge_map();
1366 initialize_input_to_output_map(unsigned int shndx
,
1367 typename
elfcpp::Elf_types
<size
>::Elf_Addr starting_address
,
1368 Unordered_map
<section_offset_type
,
1369 typename
elfcpp::Elf_types
<size
>::Elf_Addr
>* output_address
) const;
1372 add_merge_mapping(Output_section_data
*output_data
,
1373 unsigned int shndx
, section_offset_type offset
,
1374 section_size_type length
,
1375 section_offset_type output_offset
);
1378 merge_output_offset(unsigned int shndx
, section_offset_type offset
,
1379 section_offset_type
*poutput
) const;
1381 const Output_section_data
*
1382 find_merge_section(unsigned int shndx
) const;
1384 // Record the relocatable reloc info for an input reloc section.
1386 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
1388 gold_assert(reloc_shndx
< this->shnum());
1389 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
1392 // Get the relocatable reloc info for an input reloc section.
1394 relocatable_relocs(unsigned int reloc_shndx
)
1396 gold_assert(reloc_shndx
< this->shnum());
1397 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
1400 // Layout sections whose layout was deferred while waiting for
1401 // input files from a plugin.
1403 layout_deferred_sections(Layout
* layout
)
1404 { this->do_layout_deferred_sections(layout
); }
1406 // Return the index of the first incremental relocation for symbol SYMNDX.
1407 virtual unsigned int
1408 do_get_incremental_reloc_base(unsigned int symndx
) const
1409 { return this->reloc_bases_
[symndx
]; }
1411 // Return the number of incremental relocations for symbol SYMNDX.
1412 virtual unsigned int
1413 do_get_incremental_reloc_count(unsigned int symndx
) const
1414 { return this->reloc_counts_
[symndx
]; }
1416 // Return the word size of the object file.
1419 { return this->do_elfsize(); }
1421 // Return TRUE if this is a big-endian object file.
1423 is_big_endian() const
1424 { return this->do_is_big_endian(); }
1427 // The output section to be used for each input section, indexed by
1428 // the input section number. The output section is NULL if the
1429 // input section is to be discarded.
1430 typedef std::vector
<Output_section
*> Output_sections
;
1432 // Read the relocs--implemented by child class.
1434 do_read_relocs(Read_relocs_data
*) = 0;
1436 // Process the relocs--implemented by child class.
1438 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1440 // Scan the relocs--implemented by child class.
1442 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1444 // Return the value of a local symbol.
1446 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const = 0;
1448 // Return the PLT offset of a local symbol.
1449 virtual unsigned int
1450 do_local_plt_offset(unsigned int symndx
) const = 0;
1452 // Return whether a local symbol plus addend has a GOT offset
1455 do_local_has_got_offset(unsigned int symndx
,
1456 unsigned int got_type
, uint64_t addend
) const = 0;
1458 // Return the GOT offset of a given type of a local symbol plus addend.
1459 virtual unsigned int
1460 do_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1461 uint64_t addend
) const = 0;
1463 // Set the GOT offset with a given type for a local symbol plus addend.
1465 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1466 unsigned int got_offset
, uint64_t addend
) = 0;
1468 // Return whether local symbol SYMNDX is a TLS symbol.
1470 do_local_is_tls(unsigned int symndx
) const = 0;
1472 // Return the number of local symbols--implemented by child class.
1473 virtual unsigned int
1474 do_local_symbol_count() const = 0;
1476 // Return the number of output local symbols--implemented by child class.
1477 virtual unsigned int
1478 do_output_local_symbol_count() const = 0;
1480 // Return the file offset for local symbols--implemented by child class.
1482 do_local_symbol_offset() const = 0;
1484 // Count local symbols--implemented by child class.
1486 do_count_local_symbols(Stringpool_template
<char>*,
1487 Stringpool_template
<char>*) = 0;
1489 // Finalize the local symbols. Set the output symbol table indexes
1490 // for the local variables, and set the offset where local symbol
1491 // information will be stored.
1492 virtual unsigned int
1493 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
1495 // Set the output dynamic symbol table indexes for the local variables.
1496 virtual unsigned int
1497 do_set_local_dynsym_indexes(unsigned int) = 0;
1499 // Set the offset where local dynamic symbol information will be stored.
1500 virtual unsigned int
1501 do_set_local_dynsym_offset(off_t
) = 0;
1503 // Relocate the input sections and write out the local
1504 // symbols--implemented by child class.
1506 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
1508 // Set the offset of a section--implemented by child class.
1510 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
1512 // Layout sections whose layout was deferred while waiting for
1513 // input files from a plugin--implemented by child class.
1515 do_layout_deferred_sections(Layout
*) = 0;
1517 // Given a section index, return the corresponding Output_section.
1518 // The return value will be NULL if the section is not included in
1521 do_output_section(unsigned int shndx
) const
1523 gold_assert(shndx
< this->output_sections_
.size());
1524 return this->output_sections_
[shndx
];
1527 // Return the vector mapping input sections to output sections.
1530 { return this->output_sections_
; }
1532 const Output_sections
&
1533 output_sections() const
1534 { return this->output_sections_
; }
1536 // Set the size of the relocatable relocs array.
1538 size_relocatable_relocs()
1540 this->map_to_relocatable_relocs_
=
1541 new std::vector
<Relocatable_relocs
*>(this->shnum());
1544 // Record that we must wait for the output sections to be written
1545 // before applying relocations.
1547 set_relocs_must_follow_section_writes()
1548 { this->relocs_must_follow_section_writes_
= true; }
1550 // Allocate the array for counting incremental relocations.
1552 allocate_incremental_reloc_counts()
1554 unsigned int nsyms
= this->do_get_global_symbols()->size();
1555 this->reloc_counts_
= new unsigned int[nsyms
];
1556 gold_assert(this->reloc_counts_
!= NULL
);
1557 memset(this->reloc_counts_
, 0, nsyms
* sizeof(unsigned int));
1560 // Record a relocation in this object referencing global symbol SYMNDX.
1561 // Used for tracking incremental link information.
1563 count_incremental_reloc(unsigned int symndx
)
1565 unsigned int nsyms
= this->do_get_global_symbols()->size();
1566 gold_assert(symndx
< nsyms
);
1567 gold_assert(this->reloc_counts_
!= NULL
);
1568 ++this->reloc_counts_
[symndx
];
1571 // Finalize the incremental relocation information.
1573 finalize_incremental_relocs(Layout
* layout
, bool clear_counts
);
1575 // Return the index of the next relocation to be written for global symbol
1576 // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
1578 next_incremental_reloc_index(unsigned int symndx
)
1580 unsigned int nsyms
= this->do_get_global_symbols()->size();
1582 gold_assert(this->reloc_counts_
!= NULL
);
1583 gold_assert(this->reloc_bases_
!= NULL
);
1584 gold_assert(symndx
< nsyms
);
1586 unsigned int counter
= this->reloc_counts_
[symndx
]++;
1587 return this->reloc_bases_
[symndx
] + counter
;
1590 // Return the word size of the object file--
1591 // implemented by child class.
1593 do_elfsize() const = 0;
1595 // Return TRUE if this is a big-endian object file--
1596 // implemented by child class.
1598 do_is_big_endian() const = 0;
1601 // Mapping from input sections to output section.
1602 Output_sections output_sections_
;
1603 // Mapping from input section index to the information recorded for
1604 // the relocations. This is only used for a relocatable link.
1605 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
1606 // Mappings for merge sections. This is managed by the code in the
1608 Object_merge_map
* object_merge_map_
;
1609 // Whether we need to wait for output sections to be written before
1610 // we can apply relocations.
1611 bool relocs_must_follow_section_writes_
;
1612 // Used to store the relocs data computed by the Read_relocs pass.
1613 // Used during garbage collection of unused sections.
1614 Read_relocs_data
* rd_
;
1615 // Used to store the symbols data computed by the Read_symbols pass.
1616 // Again used during garbage collection when laying out referenced
1618 gold::Symbols_data
* sd_
;
1619 // Per-symbol counts of relocations, for incremental links.
1620 unsigned int* reloc_counts_
;
1621 // Per-symbol base indexes of relocations, for incremental links.
1622 unsigned int* reloc_bases_
;
1623 // Index of the first dynamic relocation for this object.
1624 unsigned int first_dyn_reloc_
;
1625 // Count of dynamic relocations for this object.
1626 unsigned int dyn_reloc_count_
;
1629 // This class is used to handle relocations against a section symbol
1630 // in an SHF_MERGE section. For such a symbol, we need to know the
1631 // addend of the relocation before we can determine the final value.
1632 // The addend gives us the location in the input section, and we can
1633 // determine how it is mapped to the output section. For a
1634 // non-section symbol, we apply the addend to the final value of the
1635 // symbol; that is done in finalize_local_symbols, and does not use
1639 class Merged_symbol_value
1642 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1644 // We use a hash table to map offsets in the input section to output
1646 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
1648 Merged_symbol_value(Value input_value
, Value output_start_address
)
1649 : input_value_(input_value
), output_start_address_(output_start_address
),
1653 // Initialize the hash table.
1655 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
1657 // Release the hash table to save space.
1659 free_input_to_output_map()
1660 { this->output_addresses_
.clear(); }
1662 // Get the output value corresponding to an addend. The object and
1663 // input section index are passed in because the caller will have
1664 // them; otherwise we could store them here.
1666 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
1668 // This is a relocation against a section symbol. ADDEND is the
1669 // offset in the section. The result should be the start of some
1670 // merge area. If the object file wants something else, it should
1671 // use a regular symbol rather than a section symbol.
1672 // Unfortunately, PR 6658 shows a case in which the object file
1673 // refers to the section symbol, but uses a negative ADDEND to
1674 // compensate for a PC relative reloc. We can't handle the
1675 // general case. However, we can handle the special case of a
1676 // negative addend, by assuming that it refers to the start of the
1677 // section. Of course, that means that we have to guess when
1678 // ADDEND is negative. It is normal to see a 32-bit value here
1679 // even when the template parameter size is 64, as 64-bit object
1680 // file formats have 32-bit relocations. We know this is a merge
1681 // section, so we know it has to fit into memory. So we assume
1682 // that we won't see a value larger than a large 32-bit unsigned
1683 // value. This will break objects with very very large merge
1684 // sections; they probably break in other ways anyhow.
1685 Value input_offset
= this->input_value_
;
1686 if (addend
< 0xffffff00)
1688 input_offset
+= addend
;
1691 typename
Output_addresses::const_iterator p
=
1692 this->output_addresses_
.find(input_offset
);
1693 if (p
!= this->output_addresses_
.end())
1694 return p
->second
+ addend
;
1696 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
1701 // Get the output value for an input offset if we couldn't find it
1702 // in the hash table.
1704 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
1705 Value input_offset
) const;
1707 // The value of the section symbol in the input file. This is
1708 // normally zero, but could in principle be something else.
1710 // The start address of this merged section in the output file.
1711 Value output_start_address_
;
1712 // A hash table which maps offsets in the input section to output
1713 // addresses. This only maps specific offsets, not all offsets.
1714 Output_addresses output_addresses_
;
1717 // This POD class is holds the value of a symbol. This is used for
1718 // local symbols, and for all symbols during relocation processing.
1719 // For special sections, such as SHF_MERGE sections, this calls a
1720 // function to get the final symbol value.
1726 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1729 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1730 is_ordinary_shndx_(false), is_section_symbol_(false),
1731 is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
1732 { this->u_
.value
= 0; }
1736 if (!this->has_output_value_
)
1737 delete this->u_
.merged_symbol_value
;
1740 // Get the value of this symbol. OBJECT is the object in which this
1741 // symbol is defined, and ADDEND is an addend to add to the value.
1742 template<bool big_endian
>
1744 value(const Sized_relobj_file
<size
, big_endian
>* object
, Value addend
) const
1746 if (this->has_output_value_
)
1747 return this->u_
.value
+ addend
;
1750 gold_assert(this->is_ordinary_shndx_
);
1751 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1756 // Set the value of this symbol in the output symbol table.
1758 set_output_value(Value value
)
1759 { this->u_
.value
= value
; }
1761 // For a section symbol in a merged section, we need more
1764 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1766 gold_assert(this->is_section_symbol_
);
1767 this->has_output_value_
= false;
1768 this->u_
.merged_symbol_value
= msv
;
1771 // Initialize the input to output map for a section symbol in a
1772 // merged section. We also initialize the value of a non-section
1773 // symbol in a merged section.
1775 initialize_input_to_output_map(const Relobj
* object
)
1777 if (!this->has_output_value_
)
1779 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1780 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1781 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1785 // Free the input to output map for a section symbol in a merged
1788 free_input_to_output_map()
1790 if (!this->has_output_value_
)
1791 this->u_
.merged_symbol_value
->free_input_to_output_map();
1794 // Set the value of the symbol from the input file. This is only
1795 // called by count_local_symbols, to communicate the value to
1796 // finalize_local_symbols.
1798 set_input_value(Value value
)
1799 { this->u_
.value
= value
; }
1801 // Return the input value. This is only called by
1802 // finalize_local_symbols and (in special cases) relocate_section.
1805 { return this->u_
.value
; }
1807 // Return whether we have set the index in the output symbol table
1810 is_output_symtab_index_set() const
1812 return (this->output_symtab_index_
!= 0
1813 && this->output_symtab_index_
!= -2U);
1816 // Return whether this symbol may be discarded from the normal
1819 may_be_discarded_from_output_symtab() const
1821 gold_assert(!this->is_output_symtab_index_set());
1822 return this->output_symtab_index_
!= -2U;
1825 // Return whether this symbol has an entry in the output symbol
1828 has_output_symtab_entry() const
1830 gold_assert(this->is_output_symtab_index_set());
1831 return this->output_symtab_index_
!= -1U;
1834 // Return the index in the output symbol table.
1836 output_symtab_index() const
1838 gold_assert(this->is_output_symtab_index_set()
1839 && this->output_symtab_index_
!= -1U);
1840 return this->output_symtab_index_
;
1843 // Set the index in the output symbol table.
1845 set_output_symtab_index(unsigned int i
)
1847 gold_assert(!this->is_output_symtab_index_set());
1848 gold_assert(i
!= 0 && i
!= -1U && i
!= -2U);
1849 this->output_symtab_index_
= i
;
1852 // Record that this symbol should not go into the output symbol
1855 set_no_output_symtab_entry()
1857 gold_assert(this->output_symtab_index_
== 0);
1858 this->output_symtab_index_
= -1U;
1861 // Record that this symbol must go into the output symbol table,
1862 // because it there is a relocation that uses it.
1864 set_must_have_output_symtab_entry()
1866 gold_assert(!this->is_output_symtab_index_set());
1867 this->output_symtab_index_
= -2U;
1870 // Set the index in the output dynamic symbol table.
1872 set_needs_output_dynsym_entry()
1874 gold_assert(!this->is_section_symbol());
1875 this->output_dynsym_index_
= 0;
1878 // Return whether this symbol should go into the dynamic symbol
1881 needs_output_dynsym_entry() const
1883 return this->output_dynsym_index_
!= -1U;
1886 // Return whether this symbol has an entry in the dynamic symbol
1889 has_output_dynsym_entry() const
1891 gold_assert(this->output_dynsym_index_
!= 0);
1892 return this->output_dynsym_index_
!= -1U;
1895 // Record that this symbol should go into the dynamic symbol table.
1897 set_output_dynsym_index(unsigned int i
)
1899 gold_assert(this->output_dynsym_index_
== 0);
1900 gold_assert(i
!= 0 && i
!= -1U);
1901 this->output_dynsym_index_
= i
;
1904 // Return the index in the output dynamic symbol table.
1906 output_dynsym_index() const
1908 gold_assert(this->output_dynsym_index_
!= 0
1909 && this->output_dynsym_index_
!= -1U);
1910 return this->output_dynsym_index_
;
1913 // Set the index of the input section in the input file.
1915 set_input_shndx(unsigned int i
, bool is_ordinary
)
1917 this->input_shndx_
= i
;
1918 // input_shndx_ field is a bitfield, so make sure that the value
1920 gold_assert(this->input_shndx_
== i
);
1921 this->is_ordinary_shndx_
= is_ordinary
;
1924 // Return the index of the input section in the input file.
1926 input_shndx(bool* is_ordinary
) const
1928 *is_ordinary
= this->is_ordinary_shndx_
;
1929 return this->input_shndx_
;
1932 // Whether this is a section symbol.
1934 is_section_symbol() const
1935 { return this->is_section_symbol_
; }
1937 // Record that this is a section symbol.
1939 set_is_section_symbol()
1941 gold_assert(!this->needs_output_dynsym_entry());
1942 this->is_section_symbol_
= true;
1945 // Record that this is a TLS symbol.
1948 { this->is_tls_symbol_
= true; }
1950 // Return true if this is a TLS symbol.
1952 is_tls_symbol() const
1953 { return this->is_tls_symbol_
; }
1955 // Record that this is an IFUNC symbol.
1957 set_is_ifunc_symbol()
1958 { this->is_ifunc_symbol_
= true; }
1960 // Return true if this is an IFUNC symbol.
1962 is_ifunc_symbol() const
1963 { return this->is_ifunc_symbol_
; }
1965 // Return true if this has output value.
1967 has_output_value() const
1968 { return this->has_output_value_
; }
1971 // The index of this local symbol in the output symbol table. This
1972 // will be 0 if no value has been assigned yet, and the symbol may
1973 // be omitted. This will be -1U if the symbol should not go into
1974 // the symbol table. This will be -2U if the symbol must go into
1975 // the symbol table, but no index has been assigned yet.
1976 unsigned int output_symtab_index_
;
1977 // The index of this local symbol in the dynamic symbol table. This
1978 // will be -1U if the symbol should not go into the symbol table.
1979 unsigned int output_dynsym_index_
;
1980 // The section index in the input file in which this symbol is
1982 unsigned int input_shndx_
: 27;
1983 // Whether the section index is an ordinary index, not a special
1985 bool is_ordinary_shndx_
: 1;
1986 // Whether this is a STT_SECTION symbol.
1987 bool is_section_symbol_
: 1;
1988 // Whether this is a STT_TLS symbol.
1989 bool is_tls_symbol_
: 1;
1990 // Whether this is a STT_GNU_IFUNC symbol.
1991 bool is_ifunc_symbol_
: 1;
1992 // Whether this symbol has a value for the output file. This is
1993 // normally set to true during Layout::finalize, by
1994 // finalize_local_symbols. It will be false for a section symbol in
1995 // a merge section, as for such symbols we can not determine the
1996 // value to use in a relocation until we see the addend.
1997 bool has_output_value_
: 1;
2000 // This is used if has_output_value_ is true. Between
2001 // count_local_symbols and finalize_local_symbols, this is the
2002 // value in the input file. After finalize_local_symbols, it is
2003 // the value in the output file.
2005 // This is used if has_output_value_ is false. It points to the
2006 // information we need to get the value for a merge section.
2007 Merged_symbol_value
<size
>* merged_symbol_value
;
2011 // This type is used to modify relocations for -fsplit-stack. It is
2012 // indexed by relocation index, and means that the relocation at that
2013 // index should use the symbol from the vector, rather than the one
2014 // indicated by the relocation.
2016 class Reloc_symbol_changes
2019 Reloc_symbol_changes(size_t count
)
2024 set(size_t i
, Symbol
* sym
)
2025 { this->vec_
[i
] = sym
; }
2028 operator[](size_t i
) const
2029 { return this->vec_
[i
]; }
2032 std::vector
<Symbol
*> vec_
;
2035 // Abstract base class for a regular object file, either a real object file
2036 // or an incremental (unchanged) object. This is size and endian specific.
2038 template<int size
, bool big_endian
>
2039 class Sized_relobj
: public Relobj
2042 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
2043 typedef Relobj::Symbols Symbols
;
2045 static const Address invalid_address
= static_cast<Address
>(0) - 1;
2047 Sized_relobj(const std::string
& name
, Input_file
* input_file
)
2048 : Relobj(name
, input_file
), local_got_offsets_(), section_offsets_()
2051 Sized_relobj(const std::string
& name
, Input_file
* input_file
,
2053 : Relobj(name
, input_file
, offset
), local_got_offsets_(), section_offsets_()
2059 // If this is a regular object, return a pointer to the Sized_relobj_file
2060 // object. Otherwise, return NULL.
2061 virtual Sized_relobj_file
<size
, big_endian
>*
2065 const virtual Sized_relobj_file
<size
, big_endian
>*
2066 sized_relobj() const
2069 // Checks if the offset of input section SHNDX within its output
2070 // section is invalid.
2072 is_output_section_offset_invalid(unsigned int shndx
) const
2073 { return this->get_output_section_offset(shndx
) == invalid_address
; }
2075 // Get the offset of input section SHNDX within its output section.
2076 // This is -1 if the input section requires a special mapping, such
2077 // as a merge section. The output section can be found in the
2078 // output_sections_ field of the parent class Relobj.
2080 get_output_section_offset(unsigned int shndx
) const
2082 gold_assert(shndx
< this->section_offsets_
.size());
2083 return this->section_offsets_
[shndx
];
2086 // Iterate over local symbols, calling a visitor class V for each GOT offset
2087 // associated with a local symbol.
2089 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const;
2092 typedef Relobj::Output_sections Output_sections
;
2094 // Clear the local symbol information.
2097 { this->local_got_offsets_
.clear(); }
2099 // Return the vector of section offsets.
2100 std::vector
<Address
>&
2102 { return this->section_offsets_
; }
2104 // Get the address of an output section.
2106 do_output_section_address(unsigned int shndx
);
2108 // Get the offset of a section.
2110 do_output_section_offset(unsigned int shndx
) const
2112 Address off
= this->get_output_section_offset(shndx
);
2113 if (off
== invalid_address
)
2118 // Set the offset of a section.
2120 do_set_section_offset(unsigned int shndx
, uint64_t off
)
2122 gold_assert(shndx
< this->section_offsets_
.size());
2123 this->section_offsets_
[shndx
] =
2124 (off
== static_cast<uint64_t>(-1)
2126 : convert_types
<Address
, uint64_t>(off
));
2129 // Return whether the local symbol SYMNDX plus ADDEND has a GOT offset
2130 // of type GOT_TYPE.
2132 do_local_has_got_offset(unsigned int symndx
, unsigned int got_type
,
2133 uint64_t addend
) const
2135 Local_got_entry_key
key(symndx
, addend
);
2136 Local_got_offsets::const_iterator p
=
2137 this->local_got_offsets_
.find(key
);
2138 return (p
!= this->local_got_offsets_
.end()
2139 && p
->second
->get_offset(got_type
) != -1U);
2142 // Return the GOT offset of type GOT_TYPE of the local symbol
2143 // SYMNDX plus ADDEND.
2145 do_local_got_offset(unsigned int symndx
, unsigned int got_type
,
2146 uint64_t addend
) const
2148 Local_got_entry_key
key(symndx
, addend
);
2149 Local_got_offsets::const_iterator p
=
2150 this->local_got_offsets_
.find(key
);
2151 gold_assert(p
!= this->local_got_offsets_
.end());
2152 unsigned int off
= p
->second
->get_offset(got_type
);
2153 gold_assert(off
!= -1U);
2157 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
2158 // plus ADDEND to GOT_OFFSET.
2160 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
2161 unsigned int got_offset
, uint64_t addend
)
2163 Local_got_entry_key
key(symndx
, addend
);
2164 Local_got_offsets::const_iterator p
=
2165 this->local_got_offsets_
.find(key
);
2166 if (p
!= this->local_got_offsets_
.end())
2167 p
->second
->set_offset(got_type
, got_offset
);
2170 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
2171 std::pair
<Local_got_offsets::iterator
, bool> ins
=
2172 this->local_got_offsets_
.insert(std::make_pair(key
, g
));
2173 gold_assert(ins
.second
);
2177 // Return the word size of the object file.
2182 // Return TRUE if this is a big-endian object file.
2184 do_is_big_endian() const
2185 { return big_endian
; }
2188 // The GOT offsets of local symbols. This map also stores GOT offsets
2189 // for tp-relative offsets for TLS symbols.
2190 typedef Unordered_map
<Local_got_entry_key
, Got_offset_list
*,
2191 Local_got_entry_key::hash
,
2192 Local_got_entry_key::equal_to
> Local_got_offsets
;
2194 // GOT offsets for local non-TLS symbols, and tp-relative offsets
2195 // for TLS symbols, indexed by local got entry key class.
2196 Local_got_offsets local_got_offsets_
;
2197 // For each input section, the offset of the input section in its
2198 // output section. This is INVALID_ADDRESS if the input section requires a
2200 std::vector
<Address
> section_offsets_
;
2203 // A regular object file. This is size and endian specific.
2205 template<int size
, bool big_endian
>
2206 class Sized_relobj_file
: public Sized_relobj
<size
, big_endian
>
2209 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
2210 typedef typename Sized_relobj
<size
, big_endian
>::Symbols Symbols
;
2211 typedef std::vector
<Symbol_value
<size
> > Local_values
;
2213 static const Address invalid_address
= static_cast<Address
>(0) - 1;
2215 enum Compute_final_local_value_status
2219 // An error occurred.
2221 // The local symbol has no output section.
2225 Sized_relobj_file(const std::string
& name
,
2226 Input_file
* input_file
,
2228 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
2230 ~Sized_relobj_file();
2232 // Set up the object file based on TARGET.
2235 { this->do_setup(); }
2237 // Return a pointer to the Sized_relobj_file object.
2238 Sized_relobj_file
<size
, big_endian
>*
2242 const Sized_relobj_file
<size
, big_endian
>*
2243 sized_relobj() const
2246 // Return the ELF file type.
2249 { return this->e_type_
; }
2251 // Return the EI_OSABI.
2252 const Osabi
<size
, big_endian
>&
2254 { return this->osabi_
; }
2256 // Return the number of symbols. This is only valid after
2257 // Object::add_symbols has been called.
2259 symbol_count() const
2260 { return this->local_symbol_count_
+ this->symbols_
.size(); }
2262 // If SYM is the index of a global symbol in the object file's
2263 // symbol table, return the Symbol object. Otherwise, return NULL.
2265 global_symbol(unsigned int sym
) const
2267 if (sym
>= this->local_symbol_count_
)
2269 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
2270 return this->symbols_
[sym
- this->local_symbol_count_
];
2275 // Return the section index of symbol SYM. Set *VALUE to its value
2276 // in the object file. Set *IS_ORDINARY if this is an ordinary
2277 // section index, not a special code between SHN_LORESERVE and
2278 // SHN_HIRESERVE. Note that for a symbol which is not defined in
2279 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
2280 // it will not return the final value of the symbol in the link.
2282 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
2284 // Return a pointer to the Symbol_value structure which holds the
2285 // value of a local symbol.
2286 const Symbol_value
<size
>*
2287 local_symbol(unsigned int sym
) const
2289 gold_assert(sym
< this->local_values_
.size());
2290 return &this->local_values_
[sym
];
2293 // Return the index of local symbol SYM in the ordinary symbol
2294 // table. A value of -1U means that the symbol is not being output.
2296 symtab_index(unsigned int sym
) const
2298 gold_assert(sym
< this->local_values_
.size());
2299 return this->local_values_
[sym
].output_symtab_index();
2302 // Return the index of local symbol SYM in the dynamic symbol
2303 // table. A value of -1U means that the symbol is not being output.
2305 dynsym_index(unsigned int sym
) const
2307 gold_assert(sym
< this->local_values_
.size());
2308 return this->local_values_
[sym
].output_dynsym_index();
2311 // Return the input section index of local symbol SYM.
2313 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
2315 gold_assert(sym
< this->local_values_
.size());
2316 return this->local_values_
[sym
].input_shndx(is_ordinary
);
2319 // Record that local symbol SYM must be in the output symbol table.
2321 set_must_have_output_symtab_entry(unsigned int sym
)
2323 gold_assert(sym
< this->local_values_
.size());
2324 this->local_values_
[sym
].set_must_have_output_symtab_entry();
2327 // Record that local symbol SYM needs a dynamic symbol entry.
2329 set_needs_output_dynsym_entry(unsigned int sym
)
2331 gold_assert(sym
< this->local_values_
.size());
2332 this->local_values_
[sym
].set_needs_output_dynsym_entry();
2335 // Return whether the local symbol SYMNDX has a PLT offset.
2337 local_has_plt_offset(unsigned int symndx
) const;
2339 // Set the PLT offset of the local symbol SYMNDX.
2341 set_local_plt_offset(unsigned int symndx
, unsigned int plt_offset
);
2343 // Adjust this local symbol value. Return false if the symbol
2344 // should be discarded from the output file.
2346 adjust_local_symbol(Symbol_value
<size
>* lv
) const
2347 { return this->do_adjust_local_symbol(lv
); }
2349 // Return the name of the symbol that spans the given offset in the
2350 // specified section in this object. This is used only for error
2351 // messages and is not particularly efficient.
2353 get_symbol_location_info(unsigned int shndx
, off_t offset
,
2354 Symbol_location_info
* info
);
2356 // Look for a kept section corresponding to the given discarded section,
2357 // and return its output address. This is used only for relocations in
2358 // debugging sections.
2360 map_to_kept_section(unsigned int shndx
, std::string
& section_name
,
2363 // Look for a kept section corresponding to the given discarded section,
2364 // and return its object file.
2366 find_kept_section_object(unsigned int shndx
, unsigned int* symndx_p
) const;
2368 // Return the name of symbol SYMNDX.
2370 get_symbol_name(unsigned int symndx
);
2372 // Compute final local symbol value. R_SYM is the local symbol index.
2373 // LV_IN points to a local symbol value containing the input value.
2374 // LV_OUT points to a local symbol value storing the final output value,
2375 // which must not be a merged symbol value since before calling this
2376 // method to avoid memory leak. SYMTAB points to a symbol table.
2378 // The method returns a status code at return. If the return status is
2379 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2380 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2381 // *LV_OUT is not modified.
2382 Compute_final_local_value_status
2383 compute_final_local_value(unsigned int r_sym
,
2384 const Symbol_value
<size
>* lv_in
,
2385 Symbol_value
<size
>* lv_out
,
2386 const Symbol_table
* symtab
);
2388 // Return true if the layout for this object was deferred.
2389 bool is_deferred_layout() const
2390 { return this->is_deferred_layout_
; }
2393 typedef typename Sized_relobj
<size
, big_endian
>::Output_sections
2400 // Read the symbols.
2402 do_read_symbols(Read_symbols_data
*);
2404 // Read the symbols. This is common code for all target-specific
2405 // overrides of do_read_symbols.
2407 base_read_symbols(Read_symbols_data
*);
2409 // Return the value of a local symbol.
2411 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const
2413 const Symbol_value
<size
>* symval
= this->local_symbol(symndx
);
2414 return symval
->value(this, addend
);
2417 // Return the PLT offset for a local symbol. It is an error to call
2418 // this if it doesn't have one.
2420 do_local_plt_offset(unsigned int symndx
) const;
2422 // Return whether local symbol SYMNDX is a TLS symbol.
2424 do_local_is_tls(unsigned int symndx
) const
2425 { return this->local_symbol(symndx
)->is_tls_symbol(); }
2427 // Return the number of local symbols.
2429 do_local_symbol_count() const
2430 { return this->local_symbol_count_
; }
2432 // Return the number of local symbols in the output symbol table.
2434 do_output_local_symbol_count() const
2435 { return this->output_local_symbol_count_
; }
2437 // Return the number of local symbols in the output symbol table.
2439 do_local_symbol_offset() const
2440 { return this->local_symbol_offset_
; }
2442 // Lay out the input sections.
2444 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
2446 // Layout sections whose layout was deferred while waiting for
2447 // input files from a plugin.
2449 do_layout_deferred_sections(Layout
*);
2451 // Add the symbols to the symbol table.
2453 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
2455 Archive::Should_include
2456 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
2459 // Iterate over global symbols, calling a visitor class V for each.
2461 do_for_all_global_symbols(Read_symbols_data
* sd
,
2462 Library_base::Symbol_visitor_base
* v
);
2466 do_read_relocs(Read_relocs_data
*);
2468 // Process the relocs to find list of referenced sections. Used only
2469 // during garbage collection.
2471 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2473 // Scan the relocs and adjust the symbol table.
2475 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2477 // Count the local symbols.
2479 do_count_local_symbols(Stringpool_template
<char>*,
2480 Stringpool_template
<char>*);
2482 // Finalize the local symbols.
2484 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
2486 // Set the offset where local dynamic symbol information will be stored.
2488 do_set_local_dynsym_indexes(unsigned int);
2490 // Set the offset where local dynamic symbol information will be stored.
2492 do_set_local_dynsym_offset(off_t
);
2494 // Relocate the input sections and write out the local symbols.
2496 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
2498 // Get the size of a section.
2500 do_section_size(unsigned int shndx
)
2501 { return this->elf_file_
.section_size(shndx
); }
2503 // Get the name of a section.
2505 do_section_name(unsigned int shndx
) const
2506 { return this->elf_file_
.section_name(shndx
); }
2508 // Return the location of the contents of a section.
2509 const unsigned char*
2510 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
2513 Object::Location
loc(this->elf_file_
.section_contents(shndx
));
2514 *plen
= convert_to_section_size_type(loc
.data_size
);
2517 static const unsigned char empty
[1] = { '\0' };
2520 return this->get_view(loc
.file_offset
, *plen
, true, cache
);
2523 // Return section flags.
2525 do_section_flags(unsigned int shndx
);
2527 // Return section entsize.
2529 do_section_entsize(unsigned int shndx
);
2531 // Return section address.
2533 do_section_address(unsigned int shndx
)
2534 { return this->elf_file_
.section_addr(shndx
); }
2536 // Return section type.
2538 do_section_type(unsigned int shndx
)
2539 { return this->elf_file_
.section_type(shndx
); }
2541 // Return the section link field.
2543 do_section_link(unsigned int shndx
)
2544 { return this->elf_file_
.section_link(shndx
); }
2546 // Return the section info field.
2548 do_section_info(unsigned int shndx
)
2549 { return this->elf_file_
.section_info(shndx
); }
2551 // Return the section alignment.
2553 do_section_addralign(unsigned int shndx
)
2554 { return this->elf_file_
.section_addralign(shndx
); }
2556 // Return the Xindex structure to use.
2558 do_initialize_xindex();
2560 // Get symbol counts.
2562 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
2564 // Get the global symbols.
2566 do_get_global_symbols() const
2567 { return &this->symbols_
; }
2569 // Adjust a section index if necessary.
2571 adjust_shndx(unsigned int shndx
)
2573 if (shndx
>= elfcpp::SHN_LORESERVE
)
2574 shndx
+= this->elf_file_
.large_shndx_offset();
2578 // Initialize input to output maps for section symbols in merged
2581 initialize_input_to_output_maps();
2583 // Free the input to output maps for section symbols in merged
2586 free_input_to_output_maps();
2588 // Return symbol table section index.
2590 symtab_shndx() const
2591 { return this->symtab_shndx_
; }
2593 // Allow a child class to access the ELF file.
2594 elfcpp::Elf_file
<size
, big_endian
, Object
>*
2596 { return &this->elf_file_
; }
2598 // Allow a child class to access the local values.
2601 { return &this->local_values_
; }
2603 // Views and sizes when relocating.
2606 unsigned char* view
;
2607 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
2609 section_size_type view_size
;
2610 bool is_input_output_view
;
2611 bool is_postprocessing_view
;
2612 bool is_ctors_reverse_view
;
2615 typedef std::vector
<View_size
> Views
;
2617 // Stash away info for a number of special sections.
2618 // Return true if any of the sections found require local symbols to be read.
2620 do_find_special_sections(Read_symbols_data
* sd
);
2622 // This may be overriden by a child class.
2624 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2625 const unsigned char* pshdrs
, Output_file
* of
,
2628 // Relocate section data for a range of sections.
2630 relocate_section_range(const Symbol_table
* symtab
, const Layout
* layout
,
2631 const unsigned char* pshdrs
, Output_file
* of
,
2632 Views
* pviews
, unsigned int start_shndx
,
2633 unsigned int end_shndx
);
2635 // Adjust this local symbol value. Return false if the symbol
2636 // should be discarded from the output file.
2638 do_adjust_local_symbol(Symbol_value
<size
>*) const
2641 // Allow a child to set output local symbol count.
2643 set_output_local_symbol_count(unsigned int value
)
2644 { this->output_local_symbol_count_
= value
; }
2646 // Return the output view for a section.
2648 do_get_output_view(unsigned int, section_size_type
*) const;
2652 typedef Sized_relobj_file
<size
, big_endian
> This
;
2653 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
2654 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2655 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2656 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
2657 typedef elfcpp::Shdr_write
<size
, big_endian
> Shdr_write
;
2659 // To keep track of discarded comdat sections, we need to map a member
2660 // section index to the object and section index of the corresponding
2662 struct Kept_comdat_section
2664 Kept_comdat_section(uint64_t a_sh_size
, Kept_section
* a_kept_section
,
2665 unsigned int a_symndx
, bool a_is_comdat
)
2666 : sh_size(a_sh_size
), kept_section(a_kept_section
),
2667 symndx (a_symndx
), is_comdat(a_is_comdat
)
2669 uint64_t sh_size
; // Section size
2670 Kept_section
* kept_section
; // Kept section info
2671 unsigned int symndx
; // Index of key symbol
2672 bool is_comdat
; // True if comdat group, false if linkonce
2674 typedef std::map
<unsigned int, Kept_comdat_section
>
2675 Kept_comdat_section_table
;
2677 // Find the SHT_SYMTAB section, given the section headers.
2679 find_symtab(const unsigned char* pshdrs
);
2681 // Return whether SHDR has the right flags for a GNU style exception
2684 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
2686 // Return whether there is a section named .eh_frame which might be
2687 // a GNU style exception frame section.
2689 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
2690 section_size_type names_size
) const;
2692 // Whether to include a section group in the link.
2694 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
2695 const unsigned char*, const char*, section_size_type
,
2696 std::vector
<bool>*);
2698 // Whether to include a linkonce section in the link.
2700 include_linkonce_section(Layout
*, unsigned int, const char*,
2701 const elfcpp::Shdr
<size
, big_endian
>&);
2703 // Layout an input section.
2705 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
2706 const typename
This::Shdr
& shdr
, unsigned int sh_type
,
2707 unsigned int reloc_shndx
, unsigned int reloc_type
);
2709 // Layout an input .eh_frame section.
2711 layout_eh_frame_section(Layout
* layout
, const unsigned char* symbols_data
,
2712 section_size_type symbols_size
,
2713 const unsigned char* symbol_names_data
,
2714 section_size_type symbol_names_size
,
2715 unsigned int shndx
, const typename
This::Shdr
&,
2716 unsigned int reloc_shndx
, unsigned int reloc_type
);
2718 // Layout an input .note.gnu.property section.
2720 layout_gnu_property_section(Layout
* layout
, unsigned int shndx
);
2722 // Write section data to the output file. Record the views and
2723 // sizes in VIEWS for use when relocating.
2725 write_sections(const Layout
*, const unsigned char* pshdrs
, Output_file
*,
2728 // Relocate the sections in the output file.
2730 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2731 const unsigned char* pshdrs
, Output_file
* of
,
2733 { this->do_relocate_sections(symtab
, layout
, pshdrs
, of
, pviews
); }
2735 // Reverse the words in a section. Used for .ctors sections mapped
2736 // to .init_array sections.
2738 reverse_words(unsigned char*, section_size_type
);
2740 // Scan the input relocations for --emit-relocs.
2742 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
2743 const Read_relocs_data::Relocs_list::iterator
&);
2745 // Scan the input relocations for --emit-relocs, templatized on the
2746 // type of the relocation section.
2747 template<int sh_type
>
2749 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
2750 const unsigned char* plocal_syms
,
2751 const Read_relocs_data::Relocs_list::iterator
&,
2752 Relocatable_relocs
*);
2754 // Scan the input relocations for --incremental.
2756 incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator
&);
2758 // Scan the input relocations for --incremental, templatized on the
2759 // type of the relocation section.
2760 template<int sh_type
>
2762 incremental_relocs_scan_reltype(
2763 const Read_relocs_data::Relocs_list::iterator
&);
2766 incremental_relocs_write(const Relocate_info
<size
, big_endian
>*,
2767 unsigned int sh_type
,
2768 const unsigned char* prelocs
,
2771 Address output_offset
,
2774 template<int sh_type
>
2776 incremental_relocs_write_reltype(const Relocate_info
<size
, big_endian
>*,
2777 const unsigned char* prelocs
,
2780 Address output_offset
,
2783 // A type shared by split_stack_adjust_reltype and find_functions.
2784 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
2786 // Check for -fsplit-stack routines calling non-split-stack routines.
2788 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
2789 unsigned int sh_type
, unsigned int shndx
,
2790 const unsigned char* prelocs
, size_t reloc_count
,
2791 unsigned char* view
, section_size_type view_size
,
2792 Reloc_symbol_changes
** reloc_map
,
2793 const Sized_target
<size
, big_endian
>* target
);
2795 template<int sh_type
>
2797 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
2798 unsigned int shndx
, const unsigned char* prelocs
,
2799 size_t reloc_count
, unsigned char* view
,
2800 section_size_type view_size
,
2801 Reloc_symbol_changes
** reloc_map
,
2802 const Sized_target
<size
, big_endian
>* target
);
2804 // Find all functions in a section.
2806 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
2809 // Write out the local symbols.
2811 write_local_symbols(Output_file
*,
2812 const Stringpool_template
<char>*,
2813 const Stringpool_template
<char>*,
2814 Output_symtab_xindex
*,
2815 Output_symtab_xindex
*,
2818 // Record a mapping from discarded section SHNDX to the corresponding
2821 set_kept_comdat_section(unsigned int shndx
, bool is_comdat
,
2822 unsigned int symndx
, uint64_t sh_size
,
2823 Kept_section
* kept_section
)
2825 Kept_comdat_section
kept(sh_size
, kept_section
, symndx
, is_comdat
);
2826 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
2829 // Find the kept section corresponding to the discarded section
2830 // SHNDX. Return true if found.
2832 get_kept_comdat_section(unsigned int shndx
, bool* is_comdat
,
2833 unsigned int *symndx
, uint64_t* sh_size
,
2834 Kept_section
** kept_section
) const
2836 typename
Kept_comdat_section_table::const_iterator p
=
2837 this->kept_comdat_sections_
.find(shndx
);
2838 if (p
== this->kept_comdat_sections_
.end())
2840 *is_comdat
= p
->second
.is_comdat
;
2841 *symndx
= p
->second
.symndx
;
2842 *sh_size
= p
->second
.sh_size
;
2843 *kept_section
= p
->second
.kept_section
;
2847 // Compute final local symbol value. R_SYM is the local symbol index.
2848 // LV_IN points to a local symbol value containing the input value.
2849 // LV_OUT points to a local symbol value storing the final output value,
2850 // which must not be a merged symbol value since before calling this
2851 // method to avoid memory leak. RELOCATABLE indicates whether we are
2852 // linking a relocatable output. OUT_SECTIONS is an array of output
2853 // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
2854 // points to a symbol table.
2856 // The method returns a status code at return. If the return status is
2857 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2858 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2859 // *LV_OUT is not modified.
2860 inline Compute_final_local_value_status
2861 compute_final_local_value_internal(unsigned int r_sym
,
2862 const Symbol_value
<size
>* lv_in
,
2863 Symbol_value
<size
>* lv_out
,
2865 const Output_sections
& out_sections
,
2866 const std::vector
<Address
>& out_offsets
,
2867 const Symbol_table
* symtab
);
2869 // The PLT offsets of local symbols.
2870 typedef Unordered_map
<unsigned int, unsigned int> Local_plt_offsets
;
2872 // Saved information for sections whose layout was deferred.
2873 struct Deferred_layout
2875 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2876 Deferred_layout(unsigned int shndx
, const char* name
,
2877 unsigned int sh_type
,
2878 const unsigned char* pshdr
,
2879 unsigned int reloc_shndx
, unsigned int reloc_type
)
2880 : name_(name
), shndx_(shndx
), reloc_shndx_(reloc_shndx
),
2881 reloc_type_(reloc_type
)
2883 typename
This::Shdr_write
shdr(this->shdr_data_
);
2884 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
2885 shdr
.put_sh_type(sh_type
);
2888 unsigned int shndx_
;
2889 unsigned int reloc_shndx_
;
2890 unsigned int reloc_type_
;
2891 unsigned char shdr_data_
[shdr_size
];
2894 // General access to the ELF file.
2895 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
2897 const Osabi
<size
, big_endian
> osabi_
;
2898 // Type of ELF file (ET_REL or ET_EXEC). ET_EXEC files are allowed
2899 // as input files only for the --just-symbols option.
2901 // Index of SHT_SYMTAB section.
2902 unsigned int symtab_shndx_
;
2903 // The number of local symbols.
2904 unsigned int local_symbol_count_
;
2905 // The number of local symbols which go into the output file.
2906 unsigned int output_local_symbol_count_
;
2907 // The number of local symbols which go into the output file's dynamic
2909 unsigned int output_local_dynsym_count_
;
2910 // The entries in the symbol table for the external symbols.
2912 // Number of symbols defined in object file itself.
2913 size_t defined_count_
;
2914 // File offset for local symbols (relative to start of symbol table).
2915 off_t local_symbol_offset_
;
2916 // File offset for local dynamic symbols (absolute).
2917 off_t local_dynsym_offset_
;
2918 // Values of local symbols.
2919 Local_values local_values_
;
2920 // PLT offsets for local symbols.
2921 Local_plt_offsets local_plt_offsets_
;
2922 // Table mapping discarded comdat sections to corresponding kept sections.
2923 Kept_comdat_section_table kept_comdat_sections_
;
2924 // Whether this object has a GNU style .eh_frame section.
2926 // True if the layout of this object was deferred, waiting for plugin
2927 // replacement files.
2928 bool is_deferred_layout_
;
2929 // The list of sections whose layout was deferred.
2930 std::vector
<Deferred_layout
> deferred_layout_
;
2931 // The list of relocation sections whose layout was deferred.
2932 std::vector
<Deferred_layout
> deferred_layout_relocs_
;
2933 // Pointer to the list of output views; valid only during do_relocate().
2934 const Views
* output_views_
;
2937 // A class to manage the list of all objects.
2943 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
2946 // The type of the list of input relocateable objects.
2947 typedef std::vector
<Relobj
*> Relobj_list
;
2948 typedef Relobj_list::const_iterator Relobj_iterator
;
2950 // The type of the list of input dynamic objects.
2951 typedef std::vector
<Dynobj
*> Dynobj_list
;
2952 typedef Dynobj_list::const_iterator Dynobj_iterator
;
2954 // Add an object to the list. Return true if all is well, or false
2955 // if this object should be ignored.
2957 add_object(Object
*);
2959 // Start processing an archive.
2961 archive_start(Archive
*);
2963 // Stop processing an archive.
2965 archive_stop(Archive
*);
2967 // For each dynamic object, check whether we've seen all of its
2968 // explicit dependencies.
2970 check_dynamic_dependencies() const;
2972 // Return whether an object was found in the system library
2975 found_in_system_library_directory(const Object
*) const;
2977 // Print symbol counts.
2979 print_symbol_counts(const Symbol_table
*) const;
2981 // Print a cross reference table.
2983 print_cref(const Symbol_table
*, FILE*) const;
2985 // Iterate over all regular objects.
2988 relobj_begin() const
2989 { return this->relobj_list_
.begin(); }
2993 { return this->relobj_list_
.end(); }
2995 // Iterate over all dynamic objects.
2998 dynobj_begin() const
2999 { return this->dynobj_list_
.begin(); }
3003 { return this->dynobj_list_
.end(); }
3005 // Return whether we have seen any dynamic objects.
3008 { return !this->dynobj_list_
.empty(); }
3010 // Return the number of non dynamic objects.
3012 number_of_relobjs() const
3013 { return this->relobj_list_
.size(); }
3015 // Return the number of input objects.
3017 number_of_input_objects() const
3018 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
3021 Input_objects(const Input_objects
&);
3022 Input_objects
& operator=(const Input_objects
&);
3024 // The list of ordinary objects included in the link.
3025 Relobj_list relobj_list_
;
3026 // The list of dynamic objects included in the link.
3027 Dynobj_list dynobj_list_
;
3028 // SONAMEs that we have seen.
3029 Unordered_map
<std::string
, Object
*> sonames_
;
3030 // Manage cross-references if requested.
3034 // Some of the information we pass to the relocation routines. We
3035 // group this together to avoid passing a dozen different arguments.
3037 template<int size
, bool big_endian
>
3038 struct Relocate_info
3041 const Symbol_table
* symtab
;
3043 const Layout
* layout
;
3044 // Object being relocated.
3045 Sized_relobj_file
<size
, big_endian
>* object
;
3046 // Section index of relocation section.
3047 unsigned int reloc_shndx
;
3048 // Section header of relocation section.
3049 const unsigned char* reloc_shdr
;
3050 // Info about how relocs should be handled
3051 Relocatable_relocs
* rr
;
3052 // Section index of section being relocated.
3053 unsigned int data_shndx
;
3054 // Section header of data section.
3055 const unsigned char* data_shdr
;
3057 // Return a string showing the location of a relocation. This is
3058 // only used for error messages.
3060 location(size_t relnum
, off_t reloffset
) const;
3063 // This is used to represent a section in an object and is used as the
3064 // key type for various section maps.
3065 typedef std::pair
<Relobj
*, unsigned int> Section_id
;
3067 // This is similar to Section_id but is used when the section
3068 // pointers are const.
3069 typedef std::pair
<const Relobj
*, unsigned int> Const_section_id
;
3071 // The hash value is based on the address of an object in memory during
3072 // linking. It is okay to use this for looking up sections but never use
3073 // this in an unordered container that we want to traverse in a repeatable
3076 struct Section_id_hash
3078 size_t operator()(const Section_id
& loc
) const
3079 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
3082 struct Const_section_id_hash
3084 size_t operator()(const Const_section_id
& loc
) const
3085 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
3088 // Return whether INPUT_FILE contains an ELF object start at file
3089 // offset OFFSET. This sets *START to point to a view of the start of
3090 // the file. It sets *READ_SIZE to the number of bytes in the view.
3093 is_elf_object(Input_file
* input_file
, off_t offset
,
3094 const unsigned char** start
, int* read_size
);
3096 // Return an Object appropriate for the input file. P is BYTES long,
3097 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
3098 // this sees an object the linker is not configured to support, it
3099 // sets *PUNCONFIGURED to true and returns NULL without giving an
3103 make_elf_object(const std::string
& name
, Input_file
*,
3104 off_t offset
, const unsigned char* p
,
3105 section_offset_type bytes
, bool* punconfigured
);
3107 } // end namespace gold
3109 #endif // !defined(GOLD_OBJECT_H)