1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright (C) 2006-2021 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.
392 Osabi(unsigned char ei_osabi
)
393 : ei_osabi_(static_cast<elfcpp::ELFOSABI
>(ei_osabi
))
397 has_shf_retain(elfcpp::Elf_Xword sh_flags
) const
399 switch (this->ei_osabi_
)
401 case elfcpp::ELFOSABI_GNU
:
402 case elfcpp::ELFOSABI_FREEBSD
:
403 return (sh_flags
& elfcpp::SHF_GNU_RETAIN
) != 0;
411 ignored_sh_flags() const
413 switch (this->ei_osabi_
)
415 case elfcpp::ELFOSABI_GNU
:
416 case elfcpp::ELFOSABI_FREEBSD
:
417 return elfcpp::SHF_GNU_RETAIN
;
425 elfcpp::ELFOSABI ei_osabi_
;
428 // Object is an abstract base class which represents either a 32-bit
429 // or a 64-bit input object. This can be a regular object file
430 // (ET_REL) or a shared object (ET_DYN).
435 typedef std::vector
<Symbol
*> Symbols
;
437 // NAME is the name of the object as we would report it to the user
438 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
439 // used to read the file. OFFSET is the offset within the input
440 // file--0 for a .o or .so file, something else for a .a file.
441 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
443 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
444 is_dynamic_(is_dynamic
), is_needed_(false), uses_split_stack_(false),
445 has_no_split_stack_(false), no_export_(false),
446 is_in_system_directory_(false), as_needed_(false), xindex_(NULL
),
447 compressed_sections_(NULL
)
449 if (input_file
!= NULL
)
451 input_file
->file().add_object();
452 this->is_in_system_directory_
= input_file
->is_in_system_directory();
453 this->as_needed_
= input_file
->options().as_needed();
459 if (this->input_file_
!= NULL
)
460 this->input_file_
->file().remove_object();
463 // Return the name of the object as we would report it to the user.
466 { return this->name_
; }
468 // Get the offset into the file.
471 { return this->offset_
; }
473 // Return whether this is a dynamic object.
476 { return this->is_dynamic_
; }
478 // Return the word size of the object file.
479 virtual int elfsize() const = 0;
481 // Return TRUE if this is a big-endian object file.
482 virtual bool is_big_endian() const = 0;
484 // Return whether this object is needed--true if it is a dynamic
485 // object which defines some symbol referenced by a regular object.
486 // We keep the flag here rather than in Dynobj for convenience when
490 { return this->is_needed_
; }
492 // Record that this object is needed.
495 { this->is_needed_
= true; }
497 // Return whether this object was compiled with -fsplit-stack.
499 uses_split_stack() const
500 { return this->uses_split_stack_
; }
502 // Return whether this object contains any functions compiled with
503 // the no_split_stack attribute.
505 has_no_split_stack() const
506 { return this->has_no_split_stack_
; }
508 // Returns NULL for Objects that are not dynamic objects. This method
509 // is overridden in the Dynobj class.
512 { return this->do_dynobj(); }
514 // Returns NULL for Objects that are not plugin objects. This method
515 // is overridden in the Pluginobj class.
518 { return this->do_pluginobj(); }
520 // Get the file. We pass on const-ness.
524 gold_assert(this->input_file_
!= NULL
);
525 return this->input_file_
;
531 gold_assert(this->input_file_
!= NULL
);
532 return this->input_file_
;
535 // Lock the underlying file.
539 if (this->input_file_
!= NULL
)
540 this->input_file_
->file().lock(t
);
543 // Unlock the underlying file.
545 unlock(const Task
* t
)
547 if (this->input_file_
!= NULL
)
548 this->input_file()->file().unlock(t
);
551 // Return whether the underlying file is locked.
554 { return this->input_file_
!= NULL
&& this->input_file_
->file().is_locked(); }
556 // Return the token, so that the task can be queued.
560 if (this->input_file_
== NULL
)
562 return this->input_file()->file().token();
565 // Release the underlying file.
569 if (this->input_file_
!= NULL
)
570 this->input_file()->file().release();
573 // Return whether we should just read symbols from this file.
576 { return this->input_file()->just_symbols(); }
578 // Return whether this is an incremental object.
580 is_incremental() const
581 { return this->do_is_incremental(); }
583 // Return the last modified time of the file.
586 { return this->do_get_mtime(); }
588 // Get the number of sections.
591 { return this->shnum_
; }
593 // Return a view of the contents of a section. Set *PLEN to the
594 // size. CACHE is a hint as in File_read::get_view.
596 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
598 // Adjust a symbol's section index as needed. SYMNDX is the index
599 // of the symbol and SHNDX is the symbol's section from
600 // get_st_shndx. This returns the section index. It sets
601 // *IS_ORDINARY to indicate whether this is a normal section index,
602 // rather than a special code between SHN_LORESERVE and
605 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
607 if (shndx
< elfcpp::SHN_LORESERVE
)
609 else if (shndx
== elfcpp::SHN_XINDEX
)
611 if (this->xindex_
== NULL
)
612 this->xindex_
= this->do_initialize_xindex();
613 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
617 *is_ordinary
= false;
621 // Return the size of a section given a section index.
623 section_size(unsigned int shndx
)
624 { return this->do_section_size(shndx
); }
626 // Return the name of a section given a section index.
628 section_name(unsigned int shndx
) const
629 { return this->do_section_name(shndx
); }
631 // Return the section flags given a section index.
633 section_flags(unsigned int shndx
)
634 { return this->do_section_flags(shndx
); }
636 // Return the section entsize given a section index.
638 section_entsize(unsigned int shndx
)
639 { return this->do_section_entsize(shndx
); }
641 // Return the section address given a section index.
643 section_address(unsigned int shndx
)
644 { return this->do_section_address(shndx
); }
646 // Return the section type given a section index.
648 section_type(unsigned int shndx
)
649 { return this->do_section_type(shndx
); }
651 // Return the section link field given a section index.
653 section_link(unsigned int shndx
)
654 { return this->do_section_link(shndx
); }
656 // Return the section info field given a section index.
658 section_info(unsigned int shndx
)
659 { return this->do_section_info(shndx
); }
661 // Return the required section alignment given a section index.
663 section_addralign(unsigned int shndx
)
664 { return this->do_section_addralign(shndx
); }
666 // Return the output section given a section index.
668 output_section(unsigned int shndx
) const
669 { return this->do_output_section(shndx
); }
671 // Given a section index, return its address.
672 // The return value will be -1U if the section is specially mapped,
673 // such as a merge section.
675 output_section_address(unsigned int shndx
)
676 { return this->do_output_section_address(shndx
); }
678 // Given a section index, return the offset in the Output_section.
679 // The return value will be -1U if the section is specially mapped,
680 // such as a merge section.
682 output_section_offset(unsigned int shndx
) const
683 { return this->do_output_section_offset(shndx
); }
685 // Read the symbol information.
687 read_symbols(Read_symbols_data
* sd
)
688 { return this->do_read_symbols(sd
); }
690 // Pass sections which should be included in the link to the Layout
691 // object, and record where the sections go in the output file.
693 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
694 { this->do_layout(symtab
, layout
, sd
); }
696 // Add symbol information to the global symbol table.
698 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
699 { this->do_add_symbols(symtab
, sd
, layout
); }
701 // Add symbol information to the global symbol table.
702 Archive::Should_include
703 should_include_member(Symbol_table
* symtab
, Layout
* layout
,
704 Read_symbols_data
* sd
, std::string
* why
)
705 { return this->do_should_include_member(symtab
, layout
, sd
, why
); }
707 // Iterate over global symbols, calling a visitor class V for each.
709 for_all_global_symbols(Read_symbols_data
* sd
,
710 Library_base::Symbol_visitor_base
* v
)
711 { return this->do_for_all_global_symbols(sd
, v
); }
713 // Iterate over local symbols, calling a visitor class V for each GOT offset
714 // associated with a local symbol.
716 for_all_local_got_entries(Got_offset_list::Visitor
* v
) const
717 { this->do_for_all_local_got_entries(v
); }
719 // Functions and types for the elfcpp::Elf_file interface. This
720 // permit us to use Object as the File template parameter for
723 // The View class is returned by view. It must support a single
724 // method, data(). This is trivial, because get_view does what we
729 View(const unsigned char* p
)
738 const unsigned char* p_
;
743 view(off_t file_offset
, section_size_type data_size
)
744 { return View(this->get_view(file_offset
, data_size
, true, true)); }
748 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
750 // A location in the file.
756 Location(off_t fo
, section_size_type ds
)
757 : file_offset(fo
), data_size(ds
)
761 // Get a View given a Location.
762 View
view(Location loc
)
763 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
765 // Get a view into the underlying file.
767 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
769 return this->input_file()->file().get_view(this->offset_
, start
, size
,
773 // Get a lasting view into the underlying file.
775 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
778 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
779 size
, aligned
, cache
);
782 // Read data from the underlying file.
784 read(off_t start
, section_size_type size
, void* p
)
785 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
787 // Read multiple data from the underlying file.
789 read_multiple(const File_read::Read_multiple
& rm
)
790 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
792 // Stop caching views in the underlying file.
794 clear_view_cache_marks()
796 if (this->input_file_
!= NULL
)
797 this->input_file_
->file().clear_view_cache_marks();
800 // Get the number of global symbols defined by this object, and the
801 // number of the symbols whose final definition came from this
804 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
806 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
808 // Get the symbols defined in this object.
810 get_global_symbols() const
811 { return this->do_get_global_symbols(); }
813 // Set flag that this object was found in a system directory.
815 set_is_in_system_directory()
816 { this->is_in_system_directory_
= true; }
818 // Return whether this object was found in a system directory.
820 is_in_system_directory() const
821 { return this->is_in_system_directory_
; }
823 // Set flag that this object was linked with --as-needed.
826 { this->as_needed_
= true; }
828 // Clear flag that this object was linked with --as-needed.
831 { this->as_needed_
= false; }
833 // Return whether this object was linked with --as-needed.
836 { return this->as_needed_
; }
838 // Return whether we found this object by searching a directory.
841 { return this->input_file()->will_search_for(); }
845 { return this->no_export_
; }
848 set_no_export(bool value
)
849 { this->no_export_
= value
; }
852 section_is_compressed(unsigned int shndx
,
853 section_size_type
* uncompressed_size
,
854 elfcpp::Elf_Xword
* palign
= NULL
) const
856 if (this->compressed_sections_
== NULL
)
858 Compressed_section_map::const_iterator p
=
859 this->compressed_sections_
->find(shndx
);
860 if (p
!= this->compressed_sections_
->end())
862 if (uncompressed_size
!= NULL
)
863 *uncompressed_size
= p
->second
.size
;
865 *palign
= p
->second
.addralign
;
871 // Return a view of the decompressed contents of a section. Set *PLEN
872 // to the size. Set *IS_NEW to true if the contents need to be freed
875 decompressed_section_contents(unsigned int shndx
, section_size_type
* plen
,
876 bool* is_cached
, uint64_t* palign
= NULL
);
878 // Discard any buffers of decompressed sections. This is done
879 // at the end of the Add_symbols task.
881 discard_decompressed_sections();
883 // Return the index of the first incremental relocation for symbol SYMNDX.
885 get_incremental_reloc_base(unsigned int symndx
) const
886 { return this->do_get_incremental_reloc_base(symndx
); }
888 // Return the number of incremental relocations for symbol SYMNDX.
890 get_incremental_reloc_count(unsigned int symndx
) const
891 { return this->do_get_incremental_reloc_count(symndx
); }
893 // Return the output view for section SHNDX.
895 get_output_view(unsigned int shndx
, section_size_type
* plen
) const
896 { return this->do_get_output_view(shndx
, plen
); }
899 // Returns NULL for Objects that are not dynamic objects. This method
900 // is overridden in the Dynobj class.
905 // Returns NULL for Objects that are not plugin objects. This method
906 // is overridden in the Pluginobj class.
911 // Return TRUE if this is an incremental (unchanged) input file.
912 // We return FALSE by default; the incremental object classes
913 // override this method.
915 do_is_incremental() const
918 // Return the last modified time of the file. This method may be
919 // overridden for subclasses that don't use an actual file (e.g.,
920 // Incremental objects).
923 { return this->input_file()->file().get_mtime(); }
925 // Read the symbols--implemented by child class.
927 do_read_symbols(Read_symbols_data
*) = 0;
929 // Lay out sections--implemented by child class.
931 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
933 // Add symbol information to the global symbol table--implemented by
936 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
938 virtual Archive::Should_include
939 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
940 std::string
* why
) = 0;
942 // Iterate over global symbols, calling a visitor class V for each.
944 do_for_all_global_symbols(Read_symbols_data
* sd
,
945 Library_base::Symbol_visitor_base
* v
) = 0;
947 // Iterate over local symbols, calling a visitor class V for each GOT offset
948 // associated with a local symbol.
950 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const = 0;
952 // Return the location of the contents of a section. Implemented by
954 virtual const unsigned char*
955 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
958 // Get the size of a section--implemented by child class.
960 do_section_size(unsigned int shndx
) = 0;
962 // Get the name of a section--implemented by child class.
964 do_section_name(unsigned int shndx
) const = 0;
966 // Get section flags--implemented by child class.
968 do_section_flags(unsigned int shndx
) = 0;
970 // Get section entsize--implemented by child class.
972 do_section_entsize(unsigned int shndx
) = 0;
974 // Get section address--implemented by child class.
976 do_section_address(unsigned int shndx
) = 0;
978 // Get section type--implemented by child class.
980 do_section_type(unsigned int shndx
) = 0;
982 // Get section link field--implemented by child class.
984 do_section_link(unsigned int shndx
) = 0;
986 // Get section info field--implemented by child class.
988 do_section_info(unsigned int shndx
) = 0;
990 // Get section alignment--implemented by child class.
992 do_section_addralign(unsigned int shndx
) = 0;
994 // Return the output section given a section index--implemented
996 virtual Output_section
*
997 do_output_section(unsigned int) const
998 { gold_unreachable(); }
1000 // Get the address of a section--implemented by child class.
1002 do_output_section_address(unsigned int)
1003 { gold_unreachable(); }
1005 // Get the offset of a section--implemented by child class.
1007 do_output_section_offset(unsigned int) const
1008 { gold_unreachable(); }
1010 // Return the Xindex structure to use.
1012 do_initialize_xindex() = 0;
1014 // Implement get_global_symbol_counts--implemented by child class.
1016 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
1018 virtual const Symbols
*
1019 do_get_global_symbols() const = 0;
1021 // Set the number of sections.
1023 set_shnum(int shnum
)
1024 { this->shnum_
= shnum
; }
1026 // Functions used by both Sized_relobj_file and Sized_dynobj.
1028 // Read the section data into a Read_symbols_data object.
1029 template<int size
, bool big_endian
>
1031 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
1032 Read_symbols_data
*);
1034 // Find the section header with the given NAME. If HDR is non-NULL
1035 // then it is a section header returned from a previous call to this
1036 // function and the next section header with the same name will be
1038 template<int size
, bool big_endian
>
1039 const unsigned char*
1040 find_shdr(const unsigned char* pshdrs
, const char* name
,
1041 const char* names
, section_size_type names_size
,
1042 const unsigned char* hdr
) const;
1044 // Let the child class initialize the xindex object directly.
1046 set_xindex(Xindex
* xindex
)
1048 gold_assert(this->xindex_
== NULL
);
1049 this->xindex_
= xindex
;
1052 // If NAME is the name of a special .gnu.warning section, arrange
1053 // for the warning to be issued. SHNDX is the section index.
1054 // Return whether it is a warning section.
1056 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
1059 // If NAME is the name of the special section which indicates that
1060 // this object was compiled with -fsplit-stack, mark it accordingly,
1061 // and return true. Otherwise return false.
1063 handle_split_stack_section(const char* name
);
1065 // Discard any buffers of decompressed sections. This is done
1066 // at the end of the Add_symbols task.
1068 do_discard_decompressed_sections()
1071 // Return the index of the first incremental relocation for symbol SYMNDX--
1072 // implemented by child class.
1073 virtual unsigned int
1074 do_get_incremental_reloc_base(unsigned int) const
1075 { gold_unreachable(); }
1077 // Return the number of incremental relocations for symbol SYMNDX--
1078 // implemented by child class.
1079 virtual unsigned int
1080 do_get_incremental_reloc_count(unsigned int) const
1081 { gold_unreachable(); }
1083 // Return the output view for a section.
1084 virtual unsigned char*
1085 do_get_output_view(unsigned int, section_size_type
*) const
1086 { gold_unreachable(); }
1089 set_compressed_sections(Compressed_section_map
* compressed_sections
)
1090 { this->compressed_sections_
= compressed_sections
; }
1092 Compressed_section_map
*
1093 compressed_sections()
1094 { return this->compressed_sections_
; }
1097 // This class may not be copied.
1098 Object(const Object
&);
1099 Object
& operator=(const Object
&);
1101 // Name of object as printed to user.
1103 // For reading the file.
1104 Input_file
* input_file_
;
1105 // Offset within the file--0 for an object file, non-0 for an
1108 // Number of input sections.
1109 unsigned int shnum_
;
1110 // Whether this is a dynamic object.
1111 bool is_dynamic_
: 1;
1112 // Whether this object is needed. This is only set for dynamic
1113 // objects, and means that the object defined a symbol which was
1114 // used by a reference from a regular object.
1115 bool is_needed_
: 1;
1116 // Whether this object was compiled with -fsplit-stack.
1117 bool uses_split_stack_
: 1;
1118 // Whether this object contains any functions compiled with the
1119 // no_split_stack attribute.
1120 bool has_no_split_stack_
: 1;
1121 // True if exclude this object from automatic symbol export.
1122 // This is used only for archive objects.
1123 bool no_export_
: 1;
1124 // True if the object was found in a system directory.
1125 bool is_in_system_directory_
: 1;
1126 // True if the object was linked with --as-needed.
1127 bool as_needed_
: 1;
1128 // Many sections for objects with more than SHN_LORESERVE sections.
1130 // For compressed debug sections, map section index to uncompressed size
1132 Compressed_section_map
* compressed_sections_
;
1135 // A regular object (ET_REL). This is an abstract base class itself.
1136 // The implementation is the template class Sized_relobj_file.
1138 class Relobj
: public Object
1141 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
1142 : Object(name
, input_file
, false, offset
),
1144 map_to_relocatable_relocs_(NULL
),
1145 object_merge_map_(NULL
),
1146 relocs_must_follow_section_writes_(false),
1148 reloc_counts_(NULL
),
1150 first_dyn_reloc_(0),
1154 // During garbage collection, the Read_symbols_data pass for
1155 // each object is stored as layout needs to be done after
1156 // reloc processing.
1159 { return this->sd_
; }
1161 // Decides which section names have to be included in the worklist
1164 is_section_name_included(const char* name
);
1167 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
1168 unsigned int section_header_size
);
1171 set_symbols_data(Symbols_data
* sd
)
1174 // During garbage collection, the Read_relocs pass for all objects
1175 // is done before scanning the relocs. In that case, this->rd_ is
1176 // used to store the information from Read_relocs for each object.
1177 // This data is also used to compute the list of relevant sections.
1180 { return this->rd_
; }
1183 set_relocs_data(Read_relocs_data
* rd
)
1187 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
1191 read_relocs(Read_relocs_data
* rd
)
1192 { return this->do_read_relocs(rd
); }
1194 // Process the relocs, during garbage collection only.
1196 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1197 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
1199 // Scan the relocs and adjust the symbol table.
1201 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1202 { return this->do_scan_relocs(symtab
, layout
, rd
); }
1204 // Return the value of the local symbol whose index is SYMNDX, plus
1205 // ADDEND. ADDEND is passed in so that we can correctly handle the
1206 // section symbol for a merge section.
1208 local_symbol_value(unsigned int symndx
, uint64_t addend
) const
1209 { return this->do_local_symbol_value(symndx
, addend
); }
1211 // Return the PLT offset for a local symbol. It is an error to call
1212 // this if it doesn't have one.
1214 local_plt_offset(unsigned int symndx
) const
1215 { return this->do_local_plt_offset(symndx
); }
1217 // Return whether the local symbol SYMNDX has a GOT offset of type
1220 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1221 { return this->do_local_has_got_offset(symndx
, got_type
, 0); }
1223 // Return whether the local symbol SYMNDX plus ADDEND has a GOT offset
1224 // of type GOT_TYPE.
1226 local_has_got_offset(unsigned int symndx
, unsigned int got_type
,
1227 uint64_t addend
) const
1228 { return this->do_local_has_got_offset(symndx
, got_type
, addend
); }
1230 // Return the GOT offset of type GOT_TYPE of the local symbol
1231 // SYMNDX. It is an error to call this if the symbol does not have
1232 // a GOT offset of the specified type.
1234 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1235 { return this->do_local_got_offset(symndx
, got_type
, 0); }
1237 // Return the GOT offset of type GOT_TYPE of the local symbol
1238 // SYMNDX plus ADDEND. It is an error to call this if the symbol
1239 // does not have a GOT offset of the specified type.
1241 local_got_offset(unsigned int symndx
, unsigned int got_type
,
1242 uint64_t addend
) const
1243 { return this->do_local_got_offset(symndx
, got_type
, addend
); }
1245 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1248 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1249 unsigned int got_offset
)
1250 { this->do_set_local_got_offset(symndx
, got_type
, got_offset
, 0); }
1252 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1253 // plus ADDEND to GOT_OFFSET.
1255 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1256 unsigned int got_offset
, uint64_t addend
)
1257 { this->do_set_local_got_offset(symndx
, got_type
, got_offset
, addend
); }
1259 // Return whether the local symbol SYMNDX is a TLS symbol.
1261 local_is_tls(unsigned int symndx
) const
1262 { return this->do_local_is_tls(symndx
); }
1264 // The number of local symbols in the input symbol table.
1265 virtual unsigned int
1266 local_symbol_count() const
1267 { return this->do_local_symbol_count(); }
1269 // The number of local symbols in the output symbol table.
1270 virtual unsigned int
1271 output_local_symbol_count() const
1272 { return this->do_output_local_symbol_count(); }
1274 // The file offset for local symbols in the output symbol table.
1276 local_symbol_offset() const
1277 { return this->do_local_symbol_offset(); }
1279 // Initial local symbol processing: count the number of local symbols
1280 // in the output symbol table and dynamic symbol table; add local symbol
1281 // names to *POOL and *DYNPOOL.
1283 count_local_symbols(Stringpool_template
<char>* pool
,
1284 Stringpool_template
<char>* dynpool
)
1285 { return this->do_count_local_symbols(pool
, dynpool
); }
1287 // Set the values of the local symbols, set the output symbol table
1288 // indexes for the local variables, and set the offset where local
1289 // symbol information will be stored. Returns the new local symbol index.
1291 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
1292 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
1294 // Set the output dynamic symbol table indexes for the local variables.
1296 set_local_dynsym_indexes(unsigned int index
)
1297 { return this->do_set_local_dynsym_indexes(index
); }
1299 // Set the offset where local dynamic symbol information will be stored.
1301 set_local_dynsym_offset(off_t off
)
1302 { return this->do_set_local_dynsym_offset(off
); }
1304 // Record a dynamic relocation against an input section from this object.
1306 add_dyn_reloc(unsigned int index
)
1308 if (this->dyn_reloc_count_
== 0)
1309 this->first_dyn_reloc_
= index
;
1310 ++this->dyn_reloc_count_
;
1313 // Return the index of the first dynamic relocation.
1315 first_dyn_reloc() const
1316 { return this->first_dyn_reloc_
; }
1318 // Return the count of dynamic relocations.
1320 dyn_reloc_count() const
1321 { return this->dyn_reloc_count_
; }
1323 // Relocate the input sections and write out the local symbols.
1325 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
1326 { return this->do_relocate(symtab
, layout
, of
); }
1328 // Return whether an input section is being included in the link.
1330 is_section_included(unsigned int shndx
) const
1332 gold_assert(shndx
< this->output_sections_
.size());
1333 return this->output_sections_
[shndx
] != NULL
;
1336 // The output section of the input section with index SHNDX.
1337 // This is only used currently to remove a section from the link in
1340 set_output_section(unsigned int shndx
, Output_section
* os
)
1342 gold_assert(shndx
< this->output_sections_
.size());
1343 this->output_sections_
[shndx
] = os
;
1346 // Set the offset of an input section within its output section.
1348 set_section_offset(unsigned int shndx
, uint64_t off
)
1349 { this->do_set_section_offset(shndx
, off
); }
1351 // Return true if we need to wait for output sections to be written
1352 // before we can apply relocations. This is true if the object has
1353 // any relocations for sections which require special handling, such
1354 // as the exception frame section.
1356 relocs_must_follow_section_writes() const
1357 { return this->relocs_must_follow_section_writes_
; }
1360 get_or_create_merge_map();
1364 initialize_input_to_output_map(unsigned int shndx
,
1365 typename
elfcpp::Elf_types
<size
>::Elf_Addr starting_address
,
1366 Unordered_map
<section_offset_type
,
1367 typename
elfcpp::Elf_types
<size
>::Elf_Addr
>* output_address
) const;
1370 add_merge_mapping(Output_section_data
*output_data
,
1371 unsigned int shndx
, section_offset_type offset
,
1372 section_size_type length
,
1373 section_offset_type output_offset
);
1376 merge_output_offset(unsigned int shndx
, section_offset_type offset
,
1377 section_offset_type
*poutput
) const;
1379 const Output_section_data
*
1380 find_merge_section(unsigned int shndx
) const;
1382 // Record the relocatable reloc info for an input reloc section.
1384 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
1386 gold_assert(reloc_shndx
< this->shnum());
1387 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
1390 // Get the relocatable reloc info for an input reloc section.
1392 relocatable_relocs(unsigned int reloc_shndx
)
1394 gold_assert(reloc_shndx
< this->shnum());
1395 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
1398 // Layout sections whose layout was deferred while waiting for
1399 // input files from a plugin.
1401 layout_deferred_sections(Layout
* layout
)
1402 { this->do_layout_deferred_sections(layout
); }
1404 // Return the index of the first incremental relocation for symbol SYMNDX.
1405 virtual unsigned int
1406 do_get_incremental_reloc_base(unsigned int symndx
) const
1407 { return this->reloc_bases_
[symndx
]; }
1409 // Return the number of incremental relocations for symbol SYMNDX.
1410 virtual unsigned int
1411 do_get_incremental_reloc_count(unsigned int symndx
) const
1412 { return this->reloc_counts_
[symndx
]; }
1414 // Return the word size of the object file.
1417 { return this->do_elfsize(); }
1419 // Return TRUE if this is a big-endian object file.
1421 is_big_endian() const
1422 { return this->do_is_big_endian(); }
1425 // The output section to be used for each input section, indexed by
1426 // the input section number. The output section is NULL if the
1427 // input section is to be discarded.
1428 typedef std::vector
<Output_section
*> Output_sections
;
1430 // Read the relocs--implemented by child class.
1432 do_read_relocs(Read_relocs_data
*) = 0;
1434 // Process the relocs--implemented by child class.
1436 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1438 // Scan the relocs--implemented by child class.
1440 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1442 // Return the value of a local symbol.
1444 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const = 0;
1446 // Return the PLT offset of a local symbol.
1447 virtual unsigned int
1448 do_local_plt_offset(unsigned int symndx
) const = 0;
1450 // Return whether a local symbol plus addend has a GOT offset
1453 do_local_has_got_offset(unsigned int symndx
,
1454 unsigned int got_type
, uint64_t addend
) const = 0;
1456 // Return the GOT offset of a given type of a local symbol plus addend.
1457 virtual unsigned int
1458 do_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1459 uint64_t addend
) const = 0;
1461 // Set the GOT offset with a given type for a local symbol plus addend.
1463 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1464 unsigned int got_offset
, uint64_t addend
) = 0;
1466 // Return whether local symbol SYMNDX is a TLS symbol.
1468 do_local_is_tls(unsigned int symndx
) const = 0;
1470 // Return the number of local symbols--implemented by child class.
1471 virtual unsigned int
1472 do_local_symbol_count() const = 0;
1474 // Return the number of output local symbols--implemented by child class.
1475 virtual unsigned int
1476 do_output_local_symbol_count() const = 0;
1478 // Return the file offset for local symbols--implemented by child class.
1480 do_local_symbol_offset() const = 0;
1482 // Count local symbols--implemented by child class.
1484 do_count_local_symbols(Stringpool_template
<char>*,
1485 Stringpool_template
<char>*) = 0;
1487 // Finalize the local symbols. Set the output symbol table indexes
1488 // for the local variables, and set the offset where local symbol
1489 // information will be stored.
1490 virtual unsigned int
1491 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
1493 // Set the output dynamic symbol table indexes for the local variables.
1494 virtual unsigned int
1495 do_set_local_dynsym_indexes(unsigned int) = 0;
1497 // Set the offset where local dynamic symbol information will be stored.
1498 virtual unsigned int
1499 do_set_local_dynsym_offset(off_t
) = 0;
1501 // Relocate the input sections and write out the local
1502 // symbols--implemented by child class.
1504 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
1506 // Set the offset of a section--implemented by child class.
1508 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
1510 // Layout sections whose layout was deferred while waiting for
1511 // input files from a plugin--implemented by child class.
1513 do_layout_deferred_sections(Layout
*) = 0;
1515 // Given a section index, return the corresponding Output_section.
1516 // The return value will be NULL if the section is not included in
1519 do_output_section(unsigned int shndx
) const
1521 gold_assert(shndx
< this->output_sections_
.size());
1522 return this->output_sections_
[shndx
];
1525 // Return the vector mapping input sections to output sections.
1528 { return this->output_sections_
; }
1530 const Output_sections
&
1531 output_sections() const
1532 { return this->output_sections_
; }
1534 // Set the size of the relocatable relocs array.
1536 size_relocatable_relocs()
1538 this->map_to_relocatable_relocs_
=
1539 new std::vector
<Relocatable_relocs
*>(this->shnum());
1542 // Record that we must wait for the output sections to be written
1543 // before applying relocations.
1545 set_relocs_must_follow_section_writes()
1546 { this->relocs_must_follow_section_writes_
= true; }
1548 // Allocate the array for counting incremental relocations.
1550 allocate_incremental_reloc_counts()
1552 unsigned int nsyms
= this->do_get_global_symbols()->size();
1553 this->reloc_counts_
= new unsigned int[nsyms
];
1554 gold_assert(this->reloc_counts_
!= NULL
);
1555 memset(this->reloc_counts_
, 0, nsyms
* sizeof(unsigned int));
1558 // Record a relocation in this object referencing global symbol SYMNDX.
1559 // Used for tracking incremental link information.
1561 count_incremental_reloc(unsigned int symndx
)
1563 unsigned int nsyms
= this->do_get_global_symbols()->size();
1564 gold_assert(symndx
< nsyms
);
1565 gold_assert(this->reloc_counts_
!= NULL
);
1566 ++this->reloc_counts_
[symndx
];
1569 // Finalize the incremental relocation information.
1571 finalize_incremental_relocs(Layout
* layout
, bool clear_counts
);
1573 // Return the index of the next relocation to be written for global symbol
1574 // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
1576 next_incremental_reloc_index(unsigned int symndx
)
1578 unsigned int nsyms
= this->do_get_global_symbols()->size();
1580 gold_assert(this->reloc_counts_
!= NULL
);
1581 gold_assert(this->reloc_bases_
!= NULL
);
1582 gold_assert(symndx
< nsyms
);
1584 unsigned int counter
= this->reloc_counts_
[symndx
]++;
1585 return this->reloc_bases_
[symndx
] + counter
;
1588 // Return the word size of the object file--
1589 // implemented by child class.
1591 do_elfsize() const = 0;
1593 // Return TRUE if this is a big-endian object file--
1594 // implemented by child class.
1596 do_is_big_endian() const = 0;
1599 // Mapping from input sections to output section.
1600 Output_sections output_sections_
;
1601 // Mapping from input section index to the information recorded for
1602 // the relocations. This is only used for a relocatable link.
1603 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
1604 // Mappings for merge sections. This is managed by the code in the
1606 Object_merge_map
* object_merge_map_
;
1607 // Whether we need to wait for output sections to be written before
1608 // we can apply relocations.
1609 bool relocs_must_follow_section_writes_
;
1610 // Used to store the relocs data computed by the Read_relocs pass.
1611 // Used during garbage collection of unused sections.
1612 Read_relocs_data
* rd_
;
1613 // Used to store the symbols data computed by the Read_symbols pass.
1614 // Again used during garbage collection when laying out referenced
1616 gold::Symbols_data
* sd_
;
1617 // Per-symbol counts of relocations, for incremental links.
1618 unsigned int* reloc_counts_
;
1619 // Per-symbol base indexes of relocations, for incremental links.
1620 unsigned int* reloc_bases_
;
1621 // Index of the first dynamic relocation for this object.
1622 unsigned int first_dyn_reloc_
;
1623 // Count of dynamic relocations for this object.
1624 unsigned int dyn_reloc_count_
;
1627 // This class is used to handle relocations against a section symbol
1628 // in an SHF_MERGE section. For such a symbol, we need to know the
1629 // addend of the relocation before we can determine the final value.
1630 // The addend gives us the location in the input section, and we can
1631 // determine how it is mapped to the output section. For a
1632 // non-section symbol, we apply the addend to the final value of the
1633 // symbol; that is done in finalize_local_symbols, and does not use
1637 class Merged_symbol_value
1640 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1642 // We use a hash table to map offsets in the input section to output
1644 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
1646 Merged_symbol_value(Value input_value
, Value output_start_address
)
1647 : input_value_(input_value
), output_start_address_(output_start_address
),
1651 // Initialize the hash table.
1653 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
1655 // Release the hash table to save space.
1657 free_input_to_output_map()
1658 { this->output_addresses_
.clear(); }
1660 // Get the output value corresponding to an addend. The object and
1661 // input section index are passed in because the caller will have
1662 // them; otherwise we could store them here.
1664 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
1666 // This is a relocation against a section symbol. ADDEND is the
1667 // offset in the section. The result should be the start of some
1668 // merge area. If the object file wants something else, it should
1669 // use a regular symbol rather than a section symbol.
1670 // Unfortunately, PR 6658 shows a case in which the object file
1671 // refers to the section symbol, but uses a negative ADDEND to
1672 // compensate for a PC relative reloc. We can't handle the
1673 // general case. However, we can handle the special case of a
1674 // negative addend, by assuming that it refers to the start of the
1675 // section. Of course, that means that we have to guess when
1676 // ADDEND is negative. It is normal to see a 32-bit value here
1677 // even when the template parameter size is 64, as 64-bit object
1678 // file formats have 32-bit relocations. We know this is a merge
1679 // section, so we know it has to fit into memory. So we assume
1680 // that we won't see a value larger than a large 32-bit unsigned
1681 // value. This will break objects with very very large merge
1682 // sections; they probably break in other ways anyhow.
1683 Value input_offset
= this->input_value_
;
1684 if (addend
< 0xffffff00)
1686 input_offset
+= addend
;
1689 typename
Output_addresses::const_iterator p
=
1690 this->output_addresses_
.find(input_offset
);
1691 if (p
!= this->output_addresses_
.end())
1692 return p
->second
+ addend
;
1694 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
1699 // Get the output value for an input offset if we couldn't find it
1700 // in the hash table.
1702 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
1703 Value input_offset
) const;
1705 // The value of the section symbol in the input file. This is
1706 // normally zero, but could in principle be something else.
1708 // The start address of this merged section in the output file.
1709 Value output_start_address_
;
1710 // A hash table which maps offsets in the input section to output
1711 // addresses. This only maps specific offsets, not all offsets.
1712 Output_addresses output_addresses_
;
1715 // This POD class is holds the value of a symbol. This is used for
1716 // local symbols, and for all symbols during relocation processing.
1717 // For special sections, such as SHF_MERGE sections, this calls a
1718 // function to get the final symbol value.
1724 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1727 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1728 is_ordinary_shndx_(false), is_section_symbol_(false),
1729 is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
1730 { this->u_
.value
= 0; }
1734 if (!this->has_output_value_
)
1735 delete this->u_
.merged_symbol_value
;
1738 // Get the value of this symbol. OBJECT is the object in which this
1739 // symbol is defined, and ADDEND is an addend to add to the value.
1740 template<bool big_endian
>
1742 value(const Sized_relobj_file
<size
, big_endian
>* object
, Value addend
) const
1744 if (this->has_output_value_
)
1745 return this->u_
.value
+ addend
;
1748 gold_assert(this->is_ordinary_shndx_
);
1749 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1754 // Set the value of this symbol in the output symbol table.
1756 set_output_value(Value value
)
1757 { this->u_
.value
= value
; }
1759 // For a section symbol in a merged section, we need more
1762 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1764 gold_assert(this->is_section_symbol_
);
1765 this->has_output_value_
= false;
1766 this->u_
.merged_symbol_value
= msv
;
1769 // Initialize the input to output map for a section symbol in a
1770 // merged section. We also initialize the value of a non-section
1771 // symbol in a merged section.
1773 initialize_input_to_output_map(const Relobj
* object
)
1775 if (!this->has_output_value_
)
1777 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1778 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1779 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1783 // Free the input to output map for a section symbol in a merged
1786 free_input_to_output_map()
1788 if (!this->has_output_value_
)
1789 this->u_
.merged_symbol_value
->free_input_to_output_map();
1792 // Set the value of the symbol from the input file. This is only
1793 // called by count_local_symbols, to communicate the value to
1794 // finalize_local_symbols.
1796 set_input_value(Value value
)
1797 { this->u_
.value
= value
; }
1799 // Return the input value. This is only called by
1800 // finalize_local_symbols and (in special cases) relocate_section.
1803 { return this->u_
.value
; }
1805 // Return whether we have set the index in the output symbol table
1808 is_output_symtab_index_set() const
1810 return (this->output_symtab_index_
!= 0
1811 && this->output_symtab_index_
!= -2U);
1814 // Return whether this symbol may be discarded from the normal
1817 may_be_discarded_from_output_symtab() const
1819 gold_assert(!this->is_output_symtab_index_set());
1820 return this->output_symtab_index_
!= -2U;
1823 // Return whether this symbol has an entry in the output symbol
1826 has_output_symtab_entry() const
1828 gold_assert(this->is_output_symtab_index_set());
1829 return this->output_symtab_index_
!= -1U;
1832 // Return the index in the output symbol table.
1834 output_symtab_index() const
1836 gold_assert(this->is_output_symtab_index_set()
1837 && this->output_symtab_index_
!= -1U);
1838 return this->output_symtab_index_
;
1841 // Set the index in the output symbol table.
1843 set_output_symtab_index(unsigned int i
)
1845 gold_assert(!this->is_output_symtab_index_set());
1846 gold_assert(i
!= 0 && i
!= -1U && i
!= -2U);
1847 this->output_symtab_index_
= i
;
1850 // Record that this symbol should not go into the output symbol
1853 set_no_output_symtab_entry()
1855 gold_assert(this->output_symtab_index_
== 0);
1856 this->output_symtab_index_
= -1U;
1859 // Record that this symbol must go into the output symbol table,
1860 // because it there is a relocation that uses it.
1862 set_must_have_output_symtab_entry()
1864 gold_assert(!this->is_output_symtab_index_set());
1865 this->output_symtab_index_
= -2U;
1868 // Set the index in the output dynamic symbol table.
1870 set_needs_output_dynsym_entry()
1872 gold_assert(!this->is_section_symbol());
1873 this->output_dynsym_index_
= 0;
1876 // Return whether this symbol should go into the dynamic symbol
1879 needs_output_dynsym_entry() const
1881 return this->output_dynsym_index_
!= -1U;
1884 // Return whether this symbol has an entry in the dynamic symbol
1887 has_output_dynsym_entry() const
1889 gold_assert(this->output_dynsym_index_
!= 0);
1890 return this->output_dynsym_index_
!= -1U;
1893 // Record that this symbol should go into the dynamic symbol table.
1895 set_output_dynsym_index(unsigned int i
)
1897 gold_assert(this->output_dynsym_index_
== 0);
1898 gold_assert(i
!= 0 && i
!= -1U);
1899 this->output_dynsym_index_
= i
;
1902 // Return the index in the output dynamic symbol table.
1904 output_dynsym_index() const
1906 gold_assert(this->output_dynsym_index_
!= 0
1907 && this->output_dynsym_index_
!= -1U);
1908 return this->output_dynsym_index_
;
1911 // Set the index of the input section in the input file.
1913 set_input_shndx(unsigned int i
, bool is_ordinary
)
1915 this->input_shndx_
= i
;
1916 // input_shndx_ field is a bitfield, so make sure that the value
1918 gold_assert(this->input_shndx_
== i
);
1919 this->is_ordinary_shndx_
= is_ordinary
;
1922 // Return the index of the input section in the input file.
1924 input_shndx(bool* is_ordinary
) const
1926 *is_ordinary
= this->is_ordinary_shndx_
;
1927 return this->input_shndx_
;
1930 // Whether this is a section symbol.
1932 is_section_symbol() const
1933 { return this->is_section_symbol_
; }
1935 // Record that this is a section symbol.
1937 set_is_section_symbol()
1939 gold_assert(!this->needs_output_dynsym_entry());
1940 this->is_section_symbol_
= true;
1943 // Record that this is a TLS symbol.
1946 { this->is_tls_symbol_
= true; }
1948 // Return true if this is a TLS symbol.
1950 is_tls_symbol() const
1951 { return this->is_tls_symbol_
; }
1953 // Record that this is an IFUNC symbol.
1955 set_is_ifunc_symbol()
1956 { this->is_ifunc_symbol_
= true; }
1958 // Return true if this is an IFUNC symbol.
1960 is_ifunc_symbol() const
1961 { return this->is_ifunc_symbol_
; }
1963 // Return true if this has output value.
1965 has_output_value() const
1966 { return this->has_output_value_
; }
1969 // The index of this local symbol in the output symbol table. This
1970 // will be 0 if no value has been assigned yet, and the symbol may
1971 // be omitted. This will be -1U if the symbol should not go into
1972 // the symbol table. This will be -2U if the symbol must go into
1973 // the symbol table, but no index has been assigned yet.
1974 unsigned int output_symtab_index_
;
1975 // The index of this local symbol in the dynamic symbol table. This
1976 // will be -1U if the symbol should not go into the symbol table.
1977 unsigned int output_dynsym_index_
;
1978 // The section index in the input file in which this symbol is
1980 unsigned int input_shndx_
: 27;
1981 // Whether the section index is an ordinary index, not a special
1983 bool is_ordinary_shndx_
: 1;
1984 // Whether this is a STT_SECTION symbol.
1985 bool is_section_symbol_
: 1;
1986 // Whether this is a STT_TLS symbol.
1987 bool is_tls_symbol_
: 1;
1988 // Whether this is a STT_GNU_IFUNC symbol.
1989 bool is_ifunc_symbol_
: 1;
1990 // Whether this symbol has a value for the output file. This is
1991 // normally set to true during Layout::finalize, by
1992 // finalize_local_symbols. It will be false for a section symbol in
1993 // a merge section, as for such symbols we can not determine the
1994 // value to use in a relocation until we see the addend.
1995 bool has_output_value_
: 1;
1998 // This is used if has_output_value_ is true. Between
1999 // count_local_symbols and finalize_local_symbols, this is the
2000 // value in the input file. After finalize_local_symbols, it is
2001 // the value in the output file.
2003 // This is used if has_output_value_ is false. It points to the
2004 // information we need to get the value for a merge section.
2005 Merged_symbol_value
<size
>* merged_symbol_value
;
2009 // This type is used to modify relocations for -fsplit-stack. It is
2010 // indexed by relocation index, and means that the relocation at that
2011 // index should use the symbol from the vector, rather than the one
2012 // indicated by the relocation.
2014 class Reloc_symbol_changes
2017 Reloc_symbol_changes(size_t count
)
2022 set(size_t i
, Symbol
* sym
)
2023 { this->vec_
[i
] = sym
; }
2026 operator[](size_t i
) const
2027 { return this->vec_
[i
]; }
2030 std::vector
<Symbol
*> vec_
;
2033 // Abstract base class for a regular object file, either a real object file
2034 // or an incremental (unchanged) object. This is size and endian specific.
2036 template<int size
, bool big_endian
>
2037 class Sized_relobj
: public Relobj
2040 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
2041 typedef Relobj::Symbols Symbols
;
2043 static const Address invalid_address
= static_cast<Address
>(0) - 1;
2045 Sized_relobj(const std::string
& name
, Input_file
* input_file
)
2046 : Relobj(name
, input_file
), local_got_offsets_(), section_offsets_()
2049 Sized_relobj(const std::string
& name
, Input_file
* input_file
,
2051 : Relobj(name
, input_file
, offset
), local_got_offsets_(), section_offsets_()
2057 // If this is a regular object, return a pointer to the Sized_relobj_file
2058 // object. Otherwise, return NULL.
2059 virtual Sized_relobj_file
<size
, big_endian
>*
2063 const virtual Sized_relobj_file
<size
, big_endian
>*
2064 sized_relobj() const
2067 // Checks if the offset of input section SHNDX within its output
2068 // section is invalid.
2070 is_output_section_offset_invalid(unsigned int shndx
) const
2071 { return this->get_output_section_offset(shndx
) == invalid_address
; }
2073 // Get the offset of input section SHNDX within its output section.
2074 // This is -1 if the input section requires a special mapping, such
2075 // as a merge section. The output section can be found in the
2076 // output_sections_ field of the parent class Relobj.
2078 get_output_section_offset(unsigned int shndx
) const
2080 gold_assert(shndx
< this->section_offsets_
.size());
2081 return this->section_offsets_
[shndx
];
2084 // Iterate over local symbols, calling a visitor class V for each GOT offset
2085 // associated with a local symbol.
2087 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const;
2090 typedef Relobj::Output_sections Output_sections
;
2092 // Clear the local symbol information.
2095 { this->local_got_offsets_
.clear(); }
2097 // Return the vector of section offsets.
2098 std::vector
<Address
>&
2100 { return this->section_offsets_
; }
2102 // Get the address of an output section.
2104 do_output_section_address(unsigned int shndx
);
2106 // Get the offset of a section.
2108 do_output_section_offset(unsigned int shndx
) const
2110 Address off
= this->get_output_section_offset(shndx
);
2111 if (off
== invalid_address
)
2116 // Set the offset of a section.
2118 do_set_section_offset(unsigned int shndx
, uint64_t off
)
2120 gold_assert(shndx
< this->section_offsets_
.size());
2121 this->section_offsets_
[shndx
] =
2122 (off
== static_cast<uint64_t>(-1)
2124 : convert_types
<Address
, uint64_t>(off
));
2127 // Return whether the local symbol SYMNDX plus ADDEND has a GOT offset
2128 // of type GOT_TYPE.
2130 do_local_has_got_offset(unsigned int symndx
, unsigned int got_type
,
2131 uint64_t addend
) const
2133 Local_got_entry_key
key(symndx
, addend
);
2134 Local_got_offsets::const_iterator p
=
2135 this->local_got_offsets_
.find(key
);
2136 return (p
!= this->local_got_offsets_
.end()
2137 && p
->second
->get_offset(got_type
) != -1U);
2140 // Return the GOT offset of type GOT_TYPE of the local symbol
2141 // SYMNDX plus ADDEND.
2143 do_local_got_offset(unsigned int symndx
, unsigned int got_type
,
2144 uint64_t addend
) const
2146 Local_got_entry_key
key(symndx
, addend
);
2147 Local_got_offsets::const_iterator p
=
2148 this->local_got_offsets_
.find(key
);
2149 gold_assert(p
!= this->local_got_offsets_
.end());
2150 unsigned int off
= p
->second
->get_offset(got_type
);
2151 gold_assert(off
!= -1U);
2155 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
2156 // plus ADDEND to GOT_OFFSET.
2158 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
2159 unsigned int got_offset
, uint64_t addend
)
2161 Local_got_entry_key
key(symndx
, addend
);
2162 Local_got_offsets::const_iterator p
=
2163 this->local_got_offsets_
.find(key
);
2164 if (p
!= this->local_got_offsets_
.end())
2165 p
->second
->set_offset(got_type
, got_offset
);
2168 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
2169 std::pair
<Local_got_offsets::iterator
, bool> ins
=
2170 this->local_got_offsets_
.insert(std::make_pair(key
, g
));
2171 gold_assert(ins
.second
);
2175 // Return the word size of the object file.
2180 // Return TRUE if this is a big-endian object file.
2182 do_is_big_endian() const
2183 { return big_endian
; }
2186 // The GOT offsets of local symbols. This map also stores GOT offsets
2187 // for tp-relative offsets for TLS symbols.
2188 typedef Unordered_map
<Local_got_entry_key
, Got_offset_list
*,
2189 Local_got_entry_key::hash
,
2190 Local_got_entry_key::equal_to
> Local_got_offsets
;
2192 // GOT offsets for local non-TLS symbols, and tp-relative offsets
2193 // for TLS symbols, indexed by local got entry key class.
2194 Local_got_offsets local_got_offsets_
;
2195 // For each input section, the offset of the input section in its
2196 // output section. This is INVALID_ADDRESS if the input section requires a
2198 std::vector
<Address
> section_offsets_
;
2201 // A regular object file. This is size and endian specific.
2203 template<int size
, bool big_endian
>
2204 class Sized_relobj_file
: public Sized_relobj
<size
, big_endian
>
2207 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
2208 typedef typename Sized_relobj
<size
, big_endian
>::Symbols Symbols
;
2209 typedef std::vector
<Symbol_value
<size
> > Local_values
;
2211 static const Address invalid_address
= static_cast<Address
>(0) - 1;
2213 enum Compute_final_local_value_status
2217 // An error occurred.
2219 // The local symbol has no output section.
2223 Sized_relobj_file(const std::string
& name
,
2224 Input_file
* input_file
,
2226 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
2228 ~Sized_relobj_file();
2230 // Set up the object file based on TARGET.
2233 { this->do_setup(); }
2235 // Return a pointer to the Sized_relobj_file object.
2236 Sized_relobj_file
<size
, big_endian
>*
2240 const Sized_relobj_file
<size
, big_endian
>*
2241 sized_relobj() const
2244 // Return the ELF file type.
2247 { return this->e_type_
; }
2249 // Return the EI_OSABI.
2252 { return this->osabi_
; }
2254 // Return the number of symbols. This is only valid after
2255 // Object::add_symbols has been called.
2257 symbol_count() const
2258 { return this->local_symbol_count_
+ this->symbols_
.size(); }
2260 // If SYM is the index of a global symbol in the object file's
2261 // symbol table, return the Symbol object. Otherwise, return NULL.
2263 global_symbol(unsigned int sym
) const
2265 if (sym
>= this->local_symbol_count_
)
2267 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
2268 return this->symbols_
[sym
- this->local_symbol_count_
];
2273 // Return the section index of symbol SYM. Set *VALUE to its value
2274 // in the object file. Set *IS_ORDINARY if this is an ordinary
2275 // section index, not a special code between SHN_LORESERVE and
2276 // SHN_HIRESERVE. Note that for a symbol which is not defined in
2277 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
2278 // it will not return the final value of the symbol in the link.
2280 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
2282 // Return a pointer to the Symbol_value structure which holds the
2283 // value of a local symbol.
2284 const Symbol_value
<size
>*
2285 local_symbol(unsigned int sym
) const
2287 gold_assert(sym
< this->local_values_
.size());
2288 return &this->local_values_
[sym
];
2291 // Return the index of local symbol SYM in the ordinary symbol
2292 // table. A value of -1U means that the symbol is not being output.
2294 symtab_index(unsigned int sym
) const
2296 gold_assert(sym
< this->local_values_
.size());
2297 return this->local_values_
[sym
].output_symtab_index();
2300 // Return the index of local symbol SYM in the dynamic symbol
2301 // table. A value of -1U means that the symbol is not being output.
2303 dynsym_index(unsigned int sym
) const
2305 gold_assert(sym
< this->local_values_
.size());
2306 return this->local_values_
[sym
].output_dynsym_index();
2309 // Return the input section index of local symbol SYM.
2311 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
2313 gold_assert(sym
< this->local_values_
.size());
2314 return this->local_values_
[sym
].input_shndx(is_ordinary
);
2317 // Record that local symbol SYM must be in the output symbol table.
2319 set_must_have_output_symtab_entry(unsigned int sym
)
2321 gold_assert(sym
< this->local_values_
.size());
2322 this->local_values_
[sym
].set_must_have_output_symtab_entry();
2325 // Record that local symbol SYM needs a dynamic symbol entry.
2327 set_needs_output_dynsym_entry(unsigned int sym
)
2329 gold_assert(sym
< this->local_values_
.size());
2330 this->local_values_
[sym
].set_needs_output_dynsym_entry();
2333 // Return whether the local symbol SYMNDX has a PLT offset.
2335 local_has_plt_offset(unsigned int symndx
) const;
2337 // Set the PLT offset of the local symbol SYMNDX.
2339 set_local_plt_offset(unsigned int symndx
, unsigned int plt_offset
);
2341 // Adjust this local symbol value. Return false if the symbol
2342 // should be discarded from the output file.
2344 adjust_local_symbol(Symbol_value
<size
>* lv
) const
2345 { return this->do_adjust_local_symbol(lv
); }
2347 // Return the name of the symbol that spans the given offset in the
2348 // specified section in this object. This is used only for error
2349 // messages and is not particularly efficient.
2351 get_symbol_location_info(unsigned int shndx
, off_t offset
,
2352 Symbol_location_info
* info
);
2354 // Look for a kept section corresponding to the given discarded section,
2355 // and return its output address. This is used only for relocations in
2356 // debugging sections.
2358 map_to_kept_section(unsigned int shndx
, std::string
& section_name
,
2361 // Look for a kept section corresponding to the given discarded section,
2362 // and return its object file.
2364 find_kept_section_object(unsigned int shndx
, unsigned int* symndx_p
) const;
2366 // Return the name of symbol SYMNDX.
2368 get_symbol_name(unsigned int symndx
);
2370 // Compute final local symbol value. R_SYM is the local symbol index.
2371 // LV_IN points to a local symbol value containing the input value.
2372 // LV_OUT points to a local symbol value storing the final output value,
2373 // which must not be a merged symbol value since before calling this
2374 // method to avoid memory leak. SYMTAB points to a symbol table.
2376 // The method returns a status code at return. If the return status is
2377 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2378 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2379 // *LV_OUT is not modified.
2380 Compute_final_local_value_status
2381 compute_final_local_value(unsigned int r_sym
,
2382 const Symbol_value
<size
>* lv_in
,
2383 Symbol_value
<size
>* lv_out
,
2384 const Symbol_table
* symtab
);
2386 // Return true if the layout for this object was deferred.
2387 bool is_deferred_layout() const
2388 { return this->is_deferred_layout_
; }
2391 typedef typename Sized_relobj
<size
, big_endian
>::Output_sections
2398 // Read the symbols.
2400 do_read_symbols(Read_symbols_data
*);
2402 // Read the symbols. This is common code for all target-specific
2403 // overrides of do_read_symbols.
2405 base_read_symbols(Read_symbols_data
*);
2407 // Return the value of a local symbol.
2409 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const
2411 const Symbol_value
<size
>* symval
= this->local_symbol(symndx
);
2412 return symval
->value(this, addend
);
2415 // Return the PLT offset for a local symbol. It is an error to call
2416 // this if it doesn't have one.
2418 do_local_plt_offset(unsigned int symndx
) const;
2420 // Return whether local symbol SYMNDX is a TLS symbol.
2422 do_local_is_tls(unsigned int symndx
) const
2423 { return this->local_symbol(symndx
)->is_tls_symbol(); }
2425 // Return the number of local symbols.
2427 do_local_symbol_count() const
2428 { return this->local_symbol_count_
; }
2430 // Return the number of local symbols in the output symbol table.
2432 do_output_local_symbol_count() const
2433 { return this->output_local_symbol_count_
; }
2435 // Return the number of local symbols in the output symbol table.
2437 do_local_symbol_offset() const
2438 { return this->local_symbol_offset_
; }
2440 // Lay out the input sections.
2442 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
2444 // Layout sections whose layout was deferred while waiting for
2445 // input files from a plugin.
2447 do_layout_deferred_sections(Layout
*);
2449 // Add the symbols to the symbol table.
2451 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
2453 Archive::Should_include
2454 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
2457 // Iterate over global symbols, calling a visitor class V for each.
2459 do_for_all_global_symbols(Read_symbols_data
* sd
,
2460 Library_base::Symbol_visitor_base
* v
);
2464 do_read_relocs(Read_relocs_data
*);
2466 // Process the relocs to find list of referenced sections. Used only
2467 // during garbage collection.
2469 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2471 // Scan the relocs and adjust the symbol table.
2473 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2475 // Count the local symbols.
2477 do_count_local_symbols(Stringpool_template
<char>*,
2478 Stringpool_template
<char>*);
2480 // Finalize the local symbols.
2482 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
2484 // Set the offset where local dynamic symbol information will be stored.
2486 do_set_local_dynsym_indexes(unsigned int);
2488 // Set the offset where local dynamic symbol information will be stored.
2490 do_set_local_dynsym_offset(off_t
);
2492 // Relocate the input sections and write out the local symbols.
2494 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
2496 // Get the size of a section.
2498 do_section_size(unsigned int shndx
)
2499 { return this->elf_file_
.section_size(shndx
); }
2501 // Get the name of a section.
2503 do_section_name(unsigned int shndx
) const
2504 { return this->elf_file_
.section_name(shndx
); }
2506 // Return the location of the contents of a section.
2507 const unsigned char*
2508 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
2511 Object::Location
loc(this->elf_file_
.section_contents(shndx
));
2512 *plen
= convert_to_section_size_type(loc
.data_size
);
2515 static const unsigned char empty
[1] = { '\0' };
2518 return this->get_view(loc
.file_offset
, *plen
, true, cache
);
2521 // Return section flags.
2523 do_section_flags(unsigned int shndx
);
2525 // Return section entsize.
2527 do_section_entsize(unsigned int shndx
);
2529 // Return section address.
2531 do_section_address(unsigned int shndx
)
2532 { return this->elf_file_
.section_addr(shndx
); }
2534 // Return section type.
2536 do_section_type(unsigned int shndx
)
2537 { return this->elf_file_
.section_type(shndx
); }
2539 // Return the section link field.
2541 do_section_link(unsigned int shndx
)
2542 { return this->elf_file_
.section_link(shndx
); }
2544 // Return the section info field.
2546 do_section_info(unsigned int shndx
)
2547 { return this->elf_file_
.section_info(shndx
); }
2549 // Return the section alignment.
2551 do_section_addralign(unsigned int shndx
)
2552 { return this->elf_file_
.section_addralign(shndx
); }
2554 // Return the Xindex structure to use.
2556 do_initialize_xindex();
2558 // Get symbol counts.
2560 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
2562 // Get the global symbols.
2564 do_get_global_symbols() const
2565 { return &this->symbols_
; }
2567 // Adjust a section index if necessary.
2569 adjust_shndx(unsigned int shndx
)
2571 if (shndx
>= elfcpp::SHN_LORESERVE
)
2572 shndx
+= this->elf_file_
.large_shndx_offset();
2576 // Initialize input to output maps for section symbols in merged
2579 initialize_input_to_output_maps();
2581 // Free the input to output maps for section symbols in merged
2584 free_input_to_output_maps();
2586 // Return symbol table section index.
2588 symtab_shndx() const
2589 { return this->symtab_shndx_
; }
2591 // Allow a child class to access the ELF file.
2592 elfcpp::Elf_file
<size
, big_endian
, Object
>*
2594 { return &this->elf_file_
; }
2596 // Allow a child class to access the local values.
2599 { return &this->local_values_
; }
2601 // Views and sizes when relocating.
2604 unsigned char* view
;
2605 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
2607 section_size_type view_size
;
2608 bool is_input_output_view
;
2609 bool is_postprocessing_view
;
2610 bool is_ctors_reverse_view
;
2613 typedef std::vector
<View_size
> Views
;
2615 // Stash away info for a number of special sections.
2616 // Return true if any of the sections found require local symbols to be read.
2618 do_find_special_sections(Read_symbols_data
* sd
);
2620 // This may be overriden by a child class.
2622 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2623 const unsigned char* pshdrs
, Output_file
* of
,
2626 // Relocate section data for a range of sections.
2628 relocate_section_range(const Symbol_table
* symtab
, const Layout
* layout
,
2629 const unsigned char* pshdrs
, Output_file
* of
,
2630 Views
* pviews
, unsigned int start_shndx
,
2631 unsigned int end_shndx
);
2633 // Adjust this local symbol value. Return false if the symbol
2634 // should be discarded from the output file.
2636 do_adjust_local_symbol(Symbol_value
<size
>*) const
2639 // Allow a child to set output local symbol count.
2641 set_output_local_symbol_count(unsigned int value
)
2642 { this->output_local_symbol_count_
= value
; }
2644 // Return the output view for a section.
2646 do_get_output_view(unsigned int, section_size_type
*) const;
2650 typedef Sized_relobj_file
<size
, big_endian
> This
;
2651 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
2652 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2653 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2654 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
2655 typedef elfcpp::Shdr_write
<size
, big_endian
> Shdr_write
;
2657 // To keep track of discarded comdat sections, we need to map a member
2658 // section index to the object and section index of the corresponding
2660 struct Kept_comdat_section
2662 Kept_comdat_section(uint64_t a_sh_size
, Kept_section
* a_kept_section
,
2663 unsigned int a_symndx
, bool a_is_comdat
)
2664 : sh_size(a_sh_size
), kept_section(a_kept_section
),
2665 symndx (a_symndx
), is_comdat(a_is_comdat
)
2667 uint64_t sh_size
; // Section size
2668 Kept_section
* kept_section
; // Kept section info
2669 unsigned int symndx
; // Index of key symbol
2670 bool is_comdat
; // True if comdat group, false if linkonce
2672 typedef std::map
<unsigned int, Kept_comdat_section
>
2673 Kept_comdat_section_table
;
2675 // Find the SHT_SYMTAB section, given the section headers.
2677 find_symtab(const unsigned char* pshdrs
);
2679 // Return whether SHDR has the right flags for a GNU style exception
2682 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
2684 // Return whether there is a section named .eh_frame which might be
2685 // a GNU style exception frame section.
2687 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
2688 section_size_type names_size
) const;
2690 // Whether to include a section group in the link.
2692 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
2693 const unsigned char*, const char*, section_size_type
,
2694 std::vector
<bool>*);
2696 // Whether to include a linkonce section in the link.
2698 include_linkonce_section(Layout
*, unsigned int, const char*,
2699 const elfcpp::Shdr
<size
, big_endian
>&);
2701 // Layout an input section.
2703 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
2704 const typename
This::Shdr
& shdr
, unsigned int sh_type
,
2705 unsigned int reloc_shndx
, unsigned int reloc_type
);
2707 // Layout an input .eh_frame section.
2709 layout_eh_frame_section(Layout
* layout
, const unsigned char* symbols_data
,
2710 section_size_type symbols_size
,
2711 const unsigned char* symbol_names_data
,
2712 section_size_type symbol_names_size
,
2713 unsigned int shndx
, const typename
This::Shdr
&,
2714 unsigned int reloc_shndx
, unsigned int reloc_type
);
2716 // Layout an input .note.gnu.property section.
2718 layout_gnu_property_section(Layout
* layout
, unsigned int shndx
);
2720 // Write section data to the output file. Record the views and
2721 // sizes in VIEWS for use when relocating.
2723 write_sections(const Layout
*, const unsigned char* pshdrs
, Output_file
*,
2726 // Relocate the sections in the output file.
2728 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2729 const unsigned char* pshdrs
, Output_file
* of
,
2731 { this->do_relocate_sections(symtab
, layout
, pshdrs
, of
, pviews
); }
2733 // Reverse the words in a section. Used for .ctors sections mapped
2734 // to .init_array sections.
2736 reverse_words(unsigned char*, section_size_type
);
2738 // Scan the input relocations for --emit-relocs.
2740 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
2741 const Read_relocs_data::Relocs_list::iterator
&);
2743 // Scan the input relocations for --emit-relocs, templatized on the
2744 // type of the relocation section.
2745 template<int sh_type
>
2747 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
2748 const unsigned char* plocal_syms
,
2749 const Read_relocs_data::Relocs_list::iterator
&,
2750 Relocatable_relocs
*);
2752 // Scan the input relocations for --incremental.
2754 incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator
&);
2756 // Scan the input relocations for --incremental, templatized on the
2757 // type of the relocation section.
2758 template<int sh_type
>
2760 incremental_relocs_scan_reltype(
2761 const Read_relocs_data::Relocs_list::iterator
&);
2764 incremental_relocs_write(const Relocate_info
<size
, big_endian
>*,
2765 unsigned int sh_type
,
2766 const unsigned char* prelocs
,
2769 Address output_offset
,
2772 template<int sh_type
>
2774 incremental_relocs_write_reltype(const Relocate_info
<size
, big_endian
>*,
2775 const unsigned char* prelocs
,
2778 Address output_offset
,
2781 // A type shared by split_stack_adjust_reltype and find_functions.
2782 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
2784 // Check for -fsplit-stack routines calling non-split-stack routines.
2786 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
2787 unsigned int sh_type
, unsigned int shndx
,
2788 const unsigned char* prelocs
, size_t reloc_count
,
2789 unsigned char* view
, section_size_type view_size
,
2790 Reloc_symbol_changes
** reloc_map
,
2791 const Sized_target
<size
, big_endian
>* target
);
2793 template<int sh_type
>
2795 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
2796 unsigned int shndx
, const unsigned char* prelocs
,
2797 size_t reloc_count
, unsigned char* view
,
2798 section_size_type view_size
,
2799 Reloc_symbol_changes
** reloc_map
,
2800 const Sized_target
<size
, big_endian
>* target
);
2802 // Find all functions in a section.
2804 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
2807 // Write out the local symbols.
2809 write_local_symbols(Output_file
*,
2810 const Stringpool_template
<char>*,
2811 const Stringpool_template
<char>*,
2812 Output_symtab_xindex
*,
2813 Output_symtab_xindex
*,
2816 // Record a mapping from discarded section SHNDX to the corresponding
2819 set_kept_comdat_section(unsigned int shndx
, bool is_comdat
,
2820 unsigned int symndx
, uint64_t sh_size
,
2821 Kept_section
* kept_section
)
2823 Kept_comdat_section
kept(sh_size
, kept_section
, symndx
, is_comdat
);
2824 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
2827 // Find the kept section corresponding to the discarded section
2828 // SHNDX. Return true if found.
2830 get_kept_comdat_section(unsigned int shndx
, bool* is_comdat
,
2831 unsigned int *symndx
, uint64_t* sh_size
,
2832 Kept_section
** kept_section
) const
2834 typename
Kept_comdat_section_table::const_iterator p
=
2835 this->kept_comdat_sections_
.find(shndx
);
2836 if (p
== this->kept_comdat_sections_
.end())
2838 *is_comdat
= p
->second
.is_comdat
;
2839 *symndx
= p
->second
.symndx
;
2840 *sh_size
= p
->second
.sh_size
;
2841 *kept_section
= p
->second
.kept_section
;
2845 // Compute final local symbol value. R_SYM is the local symbol index.
2846 // LV_IN points to a local symbol value containing the input value.
2847 // LV_OUT points to a local symbol value storing the final output value,
2848 // which must not be a merged symbol value since before calling this
2849 // method to avoid memory leak. RELOCATABLE indicates whether we are
2850 // linking a relocatable output. OUT_SECTIONS is an array of output
2851 // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
2852 // points to a symbol table.
2854 // The method returns a status code at return. If the return status is
2855 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2856 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2857 // *LV_OUT is not modified.
2858 inline Compute_final_local_value_status
2859 compute_final_local_value_internal(unsigned int r_sym
,
2860 const Symbol_value
<size
>* lv_in
,
2861 Symbol_value
<size
>* lv_out
,
2863 const Output_sections
& out_sections
,
2864 const std::vector
<Address
>& out_offsets
,
2865 const Symbol_table
* symtab
);
2867 // The PLT offsets of local symbols.
2868 typedef Unordered_map
<unsigned int, unsigned int> Local_plt_offsets
;
2870 // Saved information for sections whose layout was deferred.
2871 struct Deferred_layout
2873 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2874 Deferred_layout(unsigned int shndx
, const char* name
,
2875 unsigned int sh_type
,
2876 const unsigned char* pshdr
,
2877 unsigned int reloc_shndx
, unsigned int reloc_type
)
2878 : name_(name
), shndx_(shndx
), reloc_shndx_(reloc_shndx
),
2879 reloc_type_(reloc_type
)
2881 typename
This::Shdr_write
shdr(this->shdr_data_
);
2882 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
2883 shdr
.put_sh_type(sh_type
);
2886 unsigned int shndx_
;
2887 unsigned int reloc_shndx_
;
2888 unsigned int reloc_type_
;
2889 unsigned char shdr_data_
[shdr_size
];
2892 // General access to the ELF file.
2893 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
2896 // Type of ELF file (ET_REL or ET_EXEC). ET_EXEC files are allowed
2897 // as input files only for the --just-symbols option.
2899 // Index of SHT_SYMTAB section.
2900 unsigned int symtab_shndx_
;
2901 // The number of local symbols.
2902 unsigned int local_symbol_count_
;
2903 // The number of local symbols which go into the output file.
2904 unsigned int output_local_symbol_count_
;
2905 // The number of local symbols which go into the output file's dynamic
2907 unsigned int output_local_dynsym_count_
;
2908 // The entries in the symbol table for the external symbols.
2910 // Number of symbols defined in object file itself.
2911 size_t defined_count_
;
2912 // File offset for local symbols (relative to start of symbol table).
2913 off_t local_symbol_offset_
;
2914 // File offset for local dynamic symbols (absolute).
2915 off_t local_dynsym_offset_
;
2916 // Values of local symbols.
2917 Local_values local_values_
;
2918 // PLT offsets for local symbols.
2919 Local_plt_offsets local_plt_offsets_
;
2920 // Table mapping discarded comdat sections to corresponding kept sections.
2921 Kept_comdat_section_table kept_comdat_sections_
;
2922 // Whether this object has a GNU style .eh_frame section.
2924 // True if the layout of this object was deferred, waiting for plugin
2925 // replacement files.
2926 bool is_deferred_layout_
;
2927 // The list of sections whose layout was deferred.
2928 std::vector
<Deferred_layout
> deferred_layout_
;
2929 // The list of relocation sections whose layout was deferred.
2930 std::vector
<Deferred_layout
> deferred_layout_relocs_
;
2931 // Pointer to the list of output views; valid only during do_relocate().
2932 const Views
* output_views_
;
2935 // A class to manage the list of all objects.
2941 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
2944 // The type of the list of input relocateable objects.
2945 typedef std::vector
<Relobj
*> Relobj_list
;
2946 typedef Relobj_list::const_iterator Relobj_iterator
;
2948 // The type of the list of input dynamic objects.
2949 typedef std::vector
<Dynobj
*> Dynobj_list
;
2950 typedef Dynobj_list::const_iterator Dynobj_iterator
;
2952 // Add an object to the list. Return true if all is well, or false
2953 // if this object should be ignored.
2955 add_object(Object
*);
2957 // Start processing an archive.
2959 archive_start(Archive
*);
2961 // Stop processing an archive.
2963 archive_stop(Archive
*);
2965 // For each dynamic object, check whether we've seen all of its
2966 // explicit dependencies.
2968 check_dynamic_dependencies() const;
2970 // Return whether an object was found in the system library
2973 found_in_system_library_directory(const Object
*) const;
2975 // Print symbol counts.
2977 print_symbol_counts(const Symbol_table
*) const;
2979 // Print a cross reference table.
2981 print_cref(const Symbol_table
*, FILE*) const;
2983 // Iterate over all regular objects.
2986 relobj_begin() const
2987 { return this->relobj_list_
.begin(); }
2991 { return this->relobj_list_
.end(); }
2993 // Iterate over all dynamic objects.
2996 dynobj_begin() const
2997 { return this->dynobj_list_
.begin(); }
3001 { return this->dynobj_list_
.end(); }
3003 // Return whether we have seen any dynamic objects.
3006 { return !this->dynobj_list_
.empty(); }
3008 // Return the number of non dynamic objects.
3010 number_of_relobjs() const
3011 { return this->relobj_list_
.size(); }
3013 // Return the number of input objects.
3015 number_of_input_objects() const
3016 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
3019 Input_objects(const Input_objects
&);
3020 Input_objects
& operator=(const Input_objects
&);
3022 // The list of ordinary objects included in the link.
3023 Relobj_list relobj_list_
;
3024 // The list of dynamic objects included in the link.
3025 Dynobj_list dynobj_list_
;
3026 // SONAMEs that we have seen.
3027 Unordered_map
<std::string
, Object
*> sonames_
;
3028 // Manage cross-references if requested.
3032 // Some of the information we pass to the relocation routines. We
3033 // group this together to avoid passing a dozen different arguments.
3035 template<int size
, bool big_endian
>
3036 struct Relocate_info
3039 const Symbol_table
* symtab
;
3041 const Layout
* layout
;
3042 // Object being relocated.
3043 Sized_relobj_file
<size
, big_endian
>* object
;
3044 // Section index of relocation section.
3045 unsigned int reloc_shndx
;
3046 // Section header of relocation section.
3047 const unsigned char* reloc_shdr
;
3048 // Info about how relocs should be handled
3049 Relocatable_relocs
* rr
;
3050 // Section index of section being relocated.
3051 unsigned int data_shndx
;
3052 // Section header of data section.
3053 const unsigned char* data_shdr
;
3055 // Return a string showing the location of a relocation. This is
3056 // only used for error messages.
3058 location(size_t relnum
, off_t reloffset
) const;
3061 // This is used to represent a section in an object and is used as the
3062 // key type for various section maps.
3063 typedef std::pair
<Relobj
*, unsigned int> Section_id
;
3065 // This is similar to Section_id but is used when the section
3066 // pointers are const.
3067 typedef std::pair
<const Relobj
*, unsigned int> Const_section_id
;
3069 // The hash value is based on the address of an object in memory during
3070 // linking. It is okay to use this for looking up sections but never use
3071 // this in an unordered container that we want to traverse in a repeatable
3074 struct Section_id_hash
3076 size_t operator()(const Section_id
& loc
) const
3077 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
3080 struct Const_section_id_hash
3082 size_t operator()(const Const_section_id
& loc
) const
3083 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
3086 // Return whether INPUT_FILE contains an ELF object start at file
3087 // offset OFFSET. This sets *START to point to a view of the start of
3088 // the file. It sets *READ_SIZE to the number of bytes in the view.
3091 is_elf_object(Input_file
* input_file
, off_t offset
,
3092 const unsigned char** start
, int* read_size
);
3094 // Return an Object appropriate for the input file. P is BYTES long,
3095 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
3096 // this sees an object the linker is not configured to support, it
3097 // sets *PUNCONFIGURED to true and returns NULL without giving an
3101 make_elf_object(const std::string
& name
, Input_file
*,
3102 off_t offset
, const unsigned char* p
,
3103 section_offset_type bytes
, bool* punconfigured
);
3105 } // end namespace gold
3107 #endif // !defined(GOLD_OBJECT_H)