1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright (C) 2006-2015 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
;
44 class Output_section_data
;
46 class Output_symtab_xindex
;
49 class Object_merge_map
;
50 class Relocatable_relocs
;
53 template<typename Stringpool_char
>
54 class Stringpool_template
;
56 // Data to pass from read_symbols() to add_symbols().
58 struct Read_symbols_data
61 : section_headers(NULL
), section_names(NULL
), symbols(NULL
),
62 symbol_names(NULL
), versym(NULL
), verdef(NULL
), verneed(NULL
)
68 File_view
* section_headers
;
70 File_view
* section_names
;
71 // Size of section name data in bytes.
72 section_size_type section_names_size
;
75 // Size of symbol data in bytes.
76 section_size_type symbols_size
;
77 // Offset of external symbols within symbol data. This structure
78 // sometimes contains only external symbols, in which case this will
79 // be zero. Sometimes it contains all symbols.
80 section_offset_type external_symbols_offset
;
82 File_view
* symbol_names
;
83 // Size of symbol name data in bytes.
84 section_size_type symbol_names_size
;
86 // Version information. This is only used on dynamic objects.
87 // Version symbol data (from SHT_GNU_versym section).
89 section_size_type versym_size
;
90 // Version definition data (from SHT_GNU_verdef section).
92 section_size_type verdef_size
;
93 unsigned int verdef_info
;
94 // Needed version data (from SHT_GNU_verneed section).
96 section_size_type verneed_size
;
97 unsigned int verneed_info
;
100 // Information used to print error messages.
102 struct Symbol_location_info
104 std::string source_file
;
105 std::string enclosing_symbol_name
;
106 elfcpp::STT enclosing_symbol_type
;
109 // Data about a single relocation section. This is read in
110 // read_relocs and processed in scan_relocs.
112 struct Section_relocs
119 { delete this->contents
; }
121 // Index of reloc section.
122 unsigned int reloc_shndx
;
123 // Index of section that relocs apply to.
124 unsigned int data_shndx
;
125 // Contents of reloc section.
127 // Reloc section type.
128 unsigned int sh_type
;
129 // Number of reloc entries.
132 Output_section
* output_section
;
133 // Whether this section has special handling for offsets.
134 bool needs_special_offset_handling
;
135 // Whether the data section is allocated (has the SHF_ALLOC flag set).
136 bool is_data_section_allocated
;
139 // Relocations in an object file. This is read in read_relocs and
140 // processed in scan_relocs.
142 struct Read_relocs_data
145 : local_symbols(NULL
)
149 { delete this->local_symbols
; }
151 typedef std::vector
<Section_relocs
> Relocs_list
;
154 // The local symbols.
155 File_view
* local_symbols
;
158 // The Xindex class manages section indexes for objects with more than
164 Xindex(int large_shndx_offset
)
165 : large_shndx_offset_(large_shndx_offset
), symtab_xindex_()
168 // Initialize the symtab_xindex_ array, given the object and the
169 // section index of the symbol table to use.
170 template<int size
, bool big_endian
>
172 initialize_symtab_xindex(Object
*, unsigned int symtab_shndx
);
174 // Read in the symtab_xindex_ array, given its section index.
175 // PSHDRS may optionally point to the section headers.
176 template<int size
, bool big_endian
>
178 read_symtab_xindex(Object
*, unsigned int xindex_shndx
,
179 const unsigned char* pshdrs
);
181 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
182 // real section index.
184 sym_xindex_to_shndx(Object
* object
, unsigned int symndx
);
187 // The type of the array giving the real section index for symbols
188 // whose st_shndx field holds SHN_XINDEX.
189 typedef std::vector
<unsigned int> Symtab_xindex
;
191 // Adjust a section index if necessary. This should only be called
192 // for ordinary section indexes.
194 adjust_shndx(unsigned int shndx
)
196 if (shndx
>= elfcpp::SHN_LORESERVE
)
197 shndx
+= this->large_shndx_offset_
;
201 // Adjust to apply to large section indexes.
202 int large_shndx_offset_
;
203 // The data from the SHT_SYMTAB_SHNDX section.
204 Symtab_xindex symtab_xindex_
;
207 // A GOT offset list. A symbol may have more than one GOT offset
208 // (e.g., when mixing modules compiled with two different TLS models),
209 // but will usually have at most one. GOT_TYPE identifies the type of
210 // GOT entry; its values are specific to each target.
212 class Got_offset_list
216 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
219 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
220 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
225 if (this->got_next_
!= NULL
)
227 delete this->got_next_
;
228 this->got_next_
= NULL
;
232 // Initialize the fields to their default values.
236 this->got_type_
= -1U;
237 this->got_offset_
= 0;
238 this->got_next_
= NULL
;
241 // Set the offset for the GOT entry of type GOT_TYPE.
243 set_offset(unsigned int got_type
, unsigned int got_offset
)
245 if (this->got_type_
== -1U)
247 this->got_type_
= got_type
;
248 this->got_offset_
= got_offset
;
252 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
254 if (g
->got_type_
== got_type
)
256 g
->got_offset_
= got_offset
;
260 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
261 g
->got_next_
= this->got_next_
;
266 // Return the offset for a GOT entry of type GOT_TYPE.
268 get_offset(unsigned int got_type
) const
270 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
272 if (g
->got_type_
== got_type
)
273 return g
->got_offset_
;
278 // Return a pointer to the list, or NULL if the list is empty.
279 const Got_offset_list
*
282 if (this->got_type_
== -1U)
287 // Abstract visitor class for iterating over GOT offsets.
299 visit(unsigned int, unsigned int) = 0;
302 // Loop over all GOT offset entries, calling a visitor class V for each.
304 for_all_got_offsets(Visitor
* v
) const
306 if (this->got_type_
== -1U)
308 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
309 v
->visit(g
->got_type_
, g
->got_offset_
);
313 unsigned int got_type_
;
314 unsigned int got_offset_
;
315 Got_offset_list
* got_next_
;
318 // Type for mapping section index to uncompressed size and contents.
320 struct Compressed_section_info
322 section_size_type size
;
323 elfcpp::Elf_Xword flag
;
324 const unsigned char* contents
;
326 typedef std::map
<unsigned int, Compressed_section_info
> Compressed_section_map
;
328 template<int size
, bool big_endian
>
329 Compressed_section_map
*
330 build_compressed_section_map(const unsigned char* pshdrs
, unsigned int shnum
,
331 const char* names
, section_size_type names_size
,
332 Object
* obj
, bool decompress_if_needed
);
334 // Object is an abstract base class which represents either a 32-bit
335 // or a 64-bit input object. This can be a regular object file
336 // (ET_REL) or a shared object (ET_DYN).
341 typedef std::vector
<Symbol
*> Symbols
;
343 // NAME is the name of the object as we would report it to the user
344 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
345 // used to read the file. OFFSET is the offset within the input
346 // file--0 for a .o or .so file, something else for a .a file.
347 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
349 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
350 is_dynamic_(is_dynamic
), is_needed_(false), uses_split_stack_(false),
351 has_no_split_stack_(false), no_export_(false),
352 is_in_system_directory_(false), as_needed_(false), xindex_(NULL
),
353 compressed_sections_(NULL
)
355 if (input_file
!= NULL
)
357 input_file
->file().add_object();
358 this->is_in_system_directory_
= input_file
->is_in_system_directory();
359 this->as_needed_
= input_file
->options().as_needed();
365 if (this->input_file_
!= NULL
)
366 this->input_file_
->file().remove_object();
369 // Return the name of the object as we would report it to the user.
372 { return this->name_
; }
374 // Get the offset into the file.
377 { return this->offset_
; }
379 // Return whether this is a dynamic object.
382 { return this->is_dynamic_
; }
384 // Return the word size of the object file.
385 virtual int elfsize() const = 0;
387 // Return TRUE if this is a big-endian object file.
388 virtual bool is_big_endian() const = 0;
390 // Return whether this object is needed--true if it is a dynamic
391 // object which defines some symbol referenced by a regular object.
392 // We keep the flag here rather than in Dynobj for convenience when
396 { return this->is_needed_
; }
398 // Record that this object is needed.
401 { this->is_needed_
= true; }
403 // Return whether this object was compiled with -fsplit-stack.
405 uses_split_stack() const
406 { return this->uses_split_stack_
; }
408 // Return whether this object contains any functions compiled with
409 // the no_split_stack attribute.
411 has_no_split_stack() const
412 { return this->has_no_split_stack_
; }
414 // Returns NULL for Objects that are not dynamic objects. This method
415 // is overridden in the Dynobj class.
418 { return this->do_dynobj(); }
420 // Returns NULL for Objects that are not plugin objects. This method
421 // is overridden in the Pluginobj class.
424 { return this->do_pluginobj(); }
426 // Get the file. We pass on const-ness.
430 gold_assert(this->input_file_
!= NULL
);
431 return this->input_file_
;
437 gold_assert(this->input_file_
!= NULL
);
438 return this->input_file_
;
441 // Lock the underlying file.
445 if (this->input_file_
!= NULL
)
446 this->input_file_
->file().lock(t
);
449 // Unlock the underlying file.
451 unlock(const Task
* t
)
453 if (this->input_file_
!= NULL
)
454 this->input_file()->file().unlock(t
);
457 // Return whether the underlying file is locked.
460 { return this->input_file_
!= NULL
&& this->input_file_
->file().is_locked(); }
462 // Return the token, so that the task can be queued.
466 if (this->input_file_
== NULL
)
468 return this->input_file()->file().token();
471 // Release the underlying file.
475 if (this->input_file_
!= NULL
)
476 this->input_file()->file().release();
479 // Return whether we should just read symbols from this file.
482 { return this->input_file()->just_symbols(); }
484 // Return whether this is an incremental object.
486 is_incremental() const
487 { return this->do_is_incremental(); }
489 // Return the last modified time of the file.
492 { return this->do_get_mtime(); }
494 // Get the number of sections.
497 { return this->shnum_
; }
499 // Return a view of the contents of a section. Set *PLEN to the
500 // size. CACHE is a hint as in File_read::get_view.
502 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
504 // Adjust a symbol's section index as needed. SYMNDX is the index
505 // of the symbol and SHNDX is the symbol's section from
506 // get_st_shndx. This returns the section index. It sets
507 // *IS_ORDINARY to indicate whether this is a normal section index,
508 // rather than a special code between SHN_LORESERVE and
511 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
513 if (shndx
< elfcpp::SHN_LORESERVE
)
515 else if (shndx
== elfcpp::SHN_XINDEX
)
517 if (this->xindex_
== NULL
)
518 this->xindex_
= this->do_initialize_xindex();
519 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
523 *is_ordinary
= false;
527 // Return the size of a section given a section index.
529 section_size(unsigned int shndx
)
530 { return this->do_section_size(shndx
); }
532 // Return the name of a section given a section index.
534 section_name(unsigned int shndx
) const
535 { return this->do_section_name(shndx
); }
537 // Return the section flags given a section index.
539 section_flags(unsigned int shndx
)
540 { return this->do_section_flags(shndx
); }
542 // Return the section entsize given a section index.
544 section_entsize(unsigned int shndx
)
545 { return this->do_section_entsize(shndx
); }
547 // Return the section address given a section index.
549 section_address(unsigned int shndx
)
550 { return this->do_section_address(shndx
); }
552 // Return the section type given a section index.
554 section_type(unsigned int shndx
)
555 { return this->do_section_type(shndx
); }
557 // Return the section link field given a section index.
559 section_link(unsigned int shndx
)
560 { return this->do_section_link(shndx
); }
562 // Return the section info field given a section index.
564 section_info(unsigned int shndx
)
565 { return this->do_section_info(shndx
); }
567 // Return the required section alignment given a section index.
569 section_addralign(unsigned int shndx
)
570 { return this->do_section_addralign(shndx
); }
572 // Return the output section given a section index.
574 output_section(unsigned int shndx
) const
575 { return this->do_output_section(shndx
); }
577 // Given a section index, return its address.
578 // The return value will be -1U if the section is specially mapped,
579 // such as a merge section.
581 output_section_address(unsigned int shndx
)
582 { return this->do_output_section_address(shndx
); }
584 // Given a section index, return the offset in the Output_section.
585 // The return value will be -1U if the section is specially mapped,
586 // such as a merge section.
588 output_section_offset(unsigned int shndx
) const
589 { return this->do_output_section_offset(shndx
); }
591 // Read the symbol information.
593 read_symbols(Read_symbols_data
* sd
)
594 { return this->do_read_symbols(sd
); }
596 // Pass sections which should be included in the link to the Layout
597 // object, and record where the sections go in the output file.
599 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
600 { this->do_layout(symtab
, layout
, sd
); }
602 // Add symbol information to the global symbol table.
604 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
605 { this->do_add_symbols(symtab
, sd
, layout
); }
607 // Add symbol information to the global symbol table.
608 Archive::Should_include
609 should_include_member(Symbol_table
* symtab
, Layout
* layout
,
610 Read_symbols_data
* sd
, std::string
* why
)
611 { return this->do_should_include_member(symtab
, layout
, sd
, why
); }
613 // Iterate over global symbols, calling a visitor class V for each.
615 for_all_global_symbols(Read_symbols_data
* sd
,
616 Library_base::Symbol_visitor_base
* v
)
617 { return this->do_for_all_global_symbols(sd
, v
); }
619 // Iterate over local symbols, calling a visitor class V for each GOT offset
620 // associated with a local symbol.
622 for_all_local_got_entries(Got_offset_list::Visitor
* v
) const
623 { this->do_for_all_local_got_entries(v
); }
625 // Functions and types for the elfcpp::Elf_file interface. This
626 // permit us to use Object as the File template parameter for
629 // The View class is returned by view. It must support a single
630 // method, data(). This is trivial, because get_view does what we
635 View(const unsigned char* p
)
644 const unsigned char* p_
;
649 view(off_t file_offset
, section_size_type data_size
)
650 { return View(this->get_view(file_offset
, data_size
, true, true)); }
654 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
656 // A location in the file.
662 Location(off_t fo
, section_size_type ds
)
663 : file_offset(fo
), data_size(ds
)
667 // Get a View given a Location.
668 View
view(Location loc
)
669 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
671 // Get a view into the underlying file.
673 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
675 return this->input_file()->file().get_view(this->offset_
, start
, size
,
679 // Get a lasting view into the underlying file.
681 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
684 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
685 size
, aligned
, cache
);
688 // Read data from the underlying file.
690 read(off_t start
, section_size_type size
, void* p
)
691 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
693 // Read multiple data from the underlying file.
695 read_multiple(const File_read::Read_multiple
& rm
)
696 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
698 // Stop caching views in the underlying file.
700 clear_view_cache_marks()
702 if (this->input_file_
!= NULL
)
703 this->input_file_
->file().clear_view_cache_marks();
706 // Get the number of global symbols defined by this object, and the
707 // number of the symbols whose final definition came from this
710 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
712 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
714 // Get the symbols defined in this object.
716 get_global_symbols() const
717 { return this->do_get_global_symbols(); }
719 // Set flag that this object was found in a system directory.
721 set_is_in_system_directory()
722 { this->is_in_system_directory_
= true; }
724 // Return whether this object was found in a system directory.
726 is_in_system_directory() const
727 { return this->is_in_system_directory_
; }
729 // Set flag that this object was linked with --as-needed.
732 { this->as_needed_
= true; }
734 // Clear flag that this object was linked with --as-needed.
737 { this->as_needed_
= false; }
739 // Return whether this object was linked with --as-needed.
742 { return this->as_needed_
; }
744 // Return whether we found this object by searching a directory.
747 { return this->input_file()->will_search_for(); }
751 { return this->no_export_
; }
754 set_no_export(bool value
)
755 { this->no_export_
= value
; }
758 section_is_compressed(unsigned int shndx
,
759 section_size_type
* uncompressed_size
) const
761 if (this->compressed_sections_
== NULL
)
763 Compressed_section_map::const_iterator p
=
764 this->compressed_sections_
->find(shndx
);
765 if (p
!= this->compressed_sections_
->end())
767 if (uncompressed_size
!= NULL
)
768 *uncompressed_size
= p
->second
.size
;
774 // Return a view of the decompressed contents of a section. Set *PLEN
775 // to the size. Set *IS_NEW to true if the contents need to be freed
778 decompressed_section_contents(unsigned int shndx
, section_size_type
* plen
,
781 // Discard any buffers of decompressed sections. This is done
782 // at the end of the Add_symbols task.
784 discard_decompressed_sections();
786 // Return the index of the first incremental relocation for symbol SYMNDX.
788 get_incremental_reloc_base(unsigned int symndx
) const
789 { return this->do_get_incremental_reloc_base(symndx
); }
791 // Return the number of incremental relocations for symbol SYMNDX.
793 get_incremental_reloc_count(unsigned int symndx
) const
794 { return this->do_get_incremental_reloc_count(symndx
); }
797 // Returns NULL for Objects that are not dynamic objects. This method
798 // is overridden in the Dynobj class.
803 // Returns NULL for Objects that are not plugin objects. This method
804 // is overridden in the Pluginobj class.
809 // Return TRUE if this is an incremental (unchanged) input file.
810 // We return FALSE by default; the incremental object classes
811 // override this method.
813 do_is_incremental() const
816 // Return the last modified time of the file. This method may be
817 // overridden for subclasses that don't use an actual file (e.g.,
818 // Incremental objects).
821 { return this->input_file()->file().get_mtime(); }
823 // Read the symbols--implemented by child class.
825 do_read_symbols(Read_symbols_data
*) = 0;
827 // Lay out sections--implemented by child class.
829 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
831 // Add symbol information to the global symbol table--implemented by
834 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
836 virtual Archive::Should_include
837 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
838 std::string
* why
) = 0;
840 // Iterate over global symbols, calling a visitor class V for each.
842 do_for_all_global_symbols(Read_symbols_data
* sd
,
843 Library_base::Symbol_visitor_base
* v
) = 0;
845 // Iterate over local symbols, calling a visitor class V for each GOT offset
846 // associated with a local symbol.
848 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const = 0;
850 // Return the location of the contents of a section. Implemented by
852 virtual const unsigned char*
853 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
856 // Get the size of a section--implemented by child class.
858 do_section_size(unsigned int shndx
) = 0;
860 // Get the name of a section--implemented by child class.
862 do_section_name(unsigned int shndx
) const = 0;
864 // Get section flags--implemented by child class.
866 do_section_flags(unsigned int shndx
) = 0;
868 // Get section entsize--implemented by child class.
870 do_section_entsize(unsigned int shndx
) = 0;
872 // Get section address--implemented by child class.
874 do_section_address(unsigned int shndx
) = 0;
876 // Get section type--implemented by child class.
878 do_section_type(unsigned int shndx
) = 0;
880 // Get section link field--implemented by child class.
882 do_section_link(unsigned int shndx
) = 0;
884 // Get section info field--implemented by child class.
886 do_section_info(unsigned int shndx
) = 0;
888 // Get section alignment--implemented by child class.
890 do_section_addralign(unsigned int shndx
) = 0;
892 // Return the output section given a section index--implemented
894 virtual Output_section
*
895 do_output_section(unsigned int) const
896 { gold_unreachable(); }
898 // Get the address of a section--implemented by child class.
900 do_output_section_address(unsigned int)
901 { gold_unreachable(); }
903 // Get the offset of a section--implemented by child class.
905 do_output_section_offset(unsigned int) const
906 { gold_unreachable(); }
908 // Return the Xindex structure to use.
910 do_initialize_xindex() = 0;
912 // Implement get_global_symbol_counts--implemented by child class.
914 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
916 virtual const Symbols
*
917 do_get_global_symbols() const = 0;
919 // Set the number of sections.
922 { this->shnum_
= shnum
; }
924 // Functions used by both Sized_relobj_file and Sized_dynobj.
926 // Read the section data into a Read_symbols_data object.
927 template<int size
, bool big_endian
>
929 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
932 // Find the section header with the given NAME. If HDR is non-NULL
933 // then it is a section header returned from a previous call to this
934 // function and the next section header with the same name will be
936 template<int size
, bool big_endian
>
938 find_shdr(const unsigned char* pshdrs
, const char* name
,
939 const char* names
, section_size_type names_size
,
940 const unsigned char* hdr
) const;
942 // Let the child class initialize the xindex object directly.
944 set_xindex(Xindex
* xindex
)
946 gold_assert(this->xindex_
== NULL
);
947 this->xindex_
= xindex
;
950 // If NAME is the name of a special .gnu.warning section, arrange
951 // for the warning to be issued. SHNDX is the section index.
952 // Return whether it is a warning section.
954 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
957 // If NAME is the name of the special section which indicates that
958 // this object was compiled with -fsplit-stack, mark it accordingly,
959 // and return true. Otherwise return false.
961 handle_split_stack_section(const char* name
);
963 // Discard any buffers of decompressed sections. This is done
964 // at the end of the Add_symbols task.
966 do_discard_decompressed_sections()
969 // Return the index of the first incremental relocation for symbol SYMNDX--
970 // implemented by child class.
972 do_get_incremental_reloc_base(unsigned int) const
973 { gold_unreachable(); }
975 // Return the number of incremental relocations for symbol SYMNDX--
976 // implemented by child class.
978 do_get_incremental_reloc_count(unsigned int) const
979 { gold_unreachable(); }
982 set_compressed_sections(Compressed_section_map
* compressed_sections
)
983 { this->compressed_sections_
= compressed_sections
; }
985 Compressed_section_map
*
986 compressed_sections()
987 { return this->compressed_sections_
; }
990 // This class may not be copied.
991 Object(const Object
&);
992 Object
& operator=(const Object
&);
994 // Name of object as printed to user.
996 // For reading the file.
997 Input_file
* input_file_
;
998 // Offset within the file--0 for an object file, non-0 for an
1001 // Number of input sections.
1002 unsigned int shnum_
;
1003 // Whether this is a dynamic object.
1004 bool is_dynamic_
: 1;
1005 // Whether this object is needed. This is only set for dynamic
1006 // objects, and means that the object defined a symbol which was
1007 // used by a reference from a regular object.
1008 bool is_needed_
: 1;
1009 // Whether this object was compiled with -fsplit-stack.
1010 bool uses_split_stack_
: 1;
1011 // Whether this object contains any functions compiled with the
1012 // no_split_stack attribute.
1013 bool has_no_split_stack_
: 1;
1014 // True if exclude this object from automatic symbol export.
1015 // This is used only for archive objects.
1016 bool no_export_
: 1;
1017 // True if the object was found in a system directory.
1018 bool is_in_system_directory_
: 1;
1019 // True if the object was linked with --as-needed.
1020 bool as_needed_
: 1;
1021 // Many sections for objects with more than SHN_LORESERVE sections.
1023 // For compressed debug sections, map section index to uncompressed size
1025 Compressed_section_map
* compressed_sections_
;
1028 // A regular object (ET_REL). This is an abstract base class itself.
1029 // The implementation is the template class Sized_relobj_file.
1031 class Relobj
: public Object
1034 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
1035 : Object(name
, input_file
, false, offset
),
1037 map_to_relocatable_relocs_(NULL
),
1038 object_merge_map_(NULL
),
1039 relocs_must_follow_section_writes_(false),
1041 reloc_counts_(NULL
),
1043 first_dyn_reloc_(0),
1047 // During garbage collection, the Read_symbols_data pass for
1048 // each object is stored as layout needs to be done after
1049 // reloc processing.
1052 { return this->sd_
; }
1054 // Decides which section names have to be included in the worklist
1057 is_section_name_included(const char* name
);
1060 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
1061 unsigned int section_header_size
);
1064 set_symbols_data(Symbols_data
* sd
)
1067 // During garbage collection, the Read_relocs pass for all objects
1068 // is done before scanning the relocs. In that case, this->rd_ is
1069 // used to store the information from Read_relocs for each object.
1070 // This data is also used to compute the list of relevant sections.
1073 { return this->rd_
; }
1076 set_relocs_data(Read_relocs_data
* rd
)
1080 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
1084 read_relocs(Read_relocs_data
* rd
)
1085 { return this->do_read_relocs(rd
); }
1087 // Process the relocs, during garbage collection only.
1089 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1090 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
1092 // Scan the relocs and adjust the symbol table.
1094 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1095 { return this->do_scan_relocs(symtab
, layout
, rd
); }
1097 // Return the value of the local symbol whose index is SYMNDX, plus
1098 // ADDEND. ADDEND is passed in so that we can correctly handle the
1099 // section symbol for a merge section.
1101 local_symbol_value(unsigned int symndx
, uint64_t addend
) const
1102 { return this->do_local_symbol_value(symndx
, addend
); }
1104 // Return the PLT offset for a local symbol. It is an error to call
1105 // this if it doesn't have one.
1107 local_plt_offset(unsigned int symndx
) const
1108 { return this->do_local_plt_offset(symndx
); }
1110 // Return whether the local symbol SYMNDX has a GOT offset of type
1113 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1114 { return this->do_local_has_got_offset(symndx
, got_type
); }
1116 // Return the GOT offset of type GOT_TYPE of the local symbol
1117 // SYMNDX. It is an error to call this if the symbol does not have
1118 // a GOT offset of the specified type.
1120 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1121 { return this->do_local_got_offset(symndx
, got_type
); }
1123 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1126 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1127 unsigned int got_offset
)
1128 { this->do_set_local_got_offset(symndx
, got_type
, got_offset
); }
1130 // Return whether the local symbol SYMNDX is a TLS symbol.
1132 local_is_tls(unsigned int symndx
) const
1133 { return this->do_local_is_tls(symndx
); }
1135 // The number of local symbols in the input symbol table.
1136 virtual unsigned int
1137 local_symbol_count() const
1138 { return this->do_local_symbol_count(); }
1140 // The number of local symbols in the output symbol table.
1141 virtual unsigned int
1142 output_local_symbol_count() const
1143 { return this->do_output_local_symbol_count(); }
1145 // The file offset for local symbols in the output symbol table.
1147 local_symbol_offset() const
1148 { return this->do_local_symbol_offset(); }
1150 // Initial local symbol processing: count the number of local symbols
1151 // in the output symbol table and dynamic symbol table; add local symbol
1152 // names to *POOL and *DYNPOOL.
1154 count_local_symbols(Stringpool_template
<char>* pool
,
1155 Stringpool_template
<char>* dynpool
)
1156 { return this->do_count_local_symbols(pool
, dynpool
); }
1158 // Set the values of the local symbols, set the output symbol table
1159 // indexes for the local variables, and set the offset where local
1160 // symbol information will be stored. Returns the new local symbol index.
1162 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
1163 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
1165 // Set the output dynamic symbol table indexes for the local variables.
1167 set_local_dynsym_indexes(unsigned int index
)
1168 { return this->do_set_local_dynsym_indexes(index
); }
1170 // Set the offset where local dynamic symbol information will be stored.
1172 set_local_dynsym_offset(off_t off
)
1173 { return this->do_set_local_dynsym_offset(off
); }
1175 // Record a dynamic relocation against an input section from this object.
1177 add_dyn_reloc(unsigned int index
)
1179 if (this->dyn_reloc_count_
== 0)
1180 this->first_dyn_reloc_
= index
;
1181 ++this->dyn_reloc_count_
;
1184 // Return the index of the first dynamic relocation.
1186 first_dyn_reloc() const
1187 { return this->first_dyn_reloc_
; }
1189 // Return the count of dynamic relocations.
1191 dyn_reloc_count() const
1192 { return this->dyn_reloc_count_
; }
1194 // Relocate the input sections and write out the local symbols.
1196 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
1197 { return this->do_relocate(symtab
, layout
, of
); }
1199 // Return whether an input section is being included in the link.
1201 is_section_included(unsigned int shndx
) const
1203 gold_assert(shndx
< this->output_sections_
.size());
1204 return this->output_sections_
[shndx
] != NULL
;
1207 // The output section of the input section with index SHNDX.
1208 // This is only used currently to remove a section from the link in
1211 set_output_section(unsigned int shndx
, Output_section
* os
)
1213 gold_assert(shndx
< this->output_sections_
.size());
1214 this->output_sections_
[shndx
] = os
;
1217 // Set the offset of an input section within its output section.
1219 set_section_offset(unsigned int shndx
, uint64_t off
)
1220 { this->do_set_section_offset(shndx
, off
); }
1222 // Return true if we need to wait for output sections to be written
1223 // before we can apply relocations. This is true if the object has
1224 // any relocations for sections which require special handling, such
1225 // as the exception frame section.
1227 relocs_must_follow_section_writes() const
1228 { return this->relocs_must_follow_section_writes_
; }
1231 get_or_create_merge_map();
1235 initialize_input_to_output_map(unsigned int shndx
,
1236 typename
elfcpp::Elf_types
<size
>::Elf_Addr starting_address
,
1237 Unordered_map
<section_offset_type
,
1238 typename
elfcpp::Elf_types
<size
>::Elf_Addr
>* output_address
) const;
1241 add_merge_mapping(Output_section_data
*output_data
,
1242 unsigned int shndx
, section_offset_type offset
,
1243 section_size_type length
,
1244 section_offset_type output_offset
);
1247 merge_output_offset(unsigned int shndx
, section_offset_type offset
,
1248 section_offset_type
*poutput
) const;
1250 const Output_section_data
*
1251 find_merge_section(unsigned int shndx
) const;
1253 // Record the relocatable reloc info for an input reloc section.
1255 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
1257 gold_assert(reloc_shndx
< this->shnum());
1258 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
1261 // Get the relocatable reloc info for an input reloc section.
1263 relocatable_relocs(unsigned int reloc_shndx
)
1265 gold_assert(reloc_shndx
< this->shnum());
1266 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
1269 // Layout sections whose layout was deferred while waiting for
1270 // input files from a plugin.
1272 layout_deferred_sections(Layout
* layout
)
1273 { this->do_layout_deferred_sections(layout
); }
1275 // Return the index of the first incremental relocation for symbol SYMNDX.
1276 virtual unsigned int
1277 do_get_incremental_reloc_base(unsigned int symndx
) const
1278 { return this->reloc_bases_
[symndx
]; }
1280 // Return the number of incremental relocations for symbol SYMNDX.
1281 virtual unsigned int
1282 do_get_incremental_reloc_count(unsigned int symndx
) const
1283 { return this->reloc_counts_
[symndx
]; }
1285 // Return the word size of the object file.
1288 { return this->do_elfsize(); }
1290 // Return TRUE if this is a big-endian object file.
1292 is_big_endian() const
1293 { return this->do_is_big_endian(); }
1296 // The output section to be used for each input section, indexed by
1297 // the input section number. The output section is NULL if the
1298 // input section is to be discarded.
1299 typedef std::vector
<Output_section
*> Output_sections
;
1301 // Read the relocs--implemented by child class.
1303 do_read_relocs(Read_relocs_data
*) = 0;
1305 // Process the relocs--implemented by child class.
1307 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1309 // Scan the relocs--implemented by child class.
1311 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1313 // Return the value of a local symbol.
1315 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const = 0;
1317 // Return the PLT offset of a local symbol.
1318 virtual unsigned int
1319 do_local_plt_offset(unsigned int symndx
) const = 0;
1321 // Return whether a local symbol has a GOT offset of a given type.
1323 do_local_has_got_offset(unsigned int symndx
,
1324 unsigned int got_type
) const = 0;
1326 // Return the GOT offset of a given type of a local symbol.
1327 virtual unsigned int
1328 do_local_got_offset(unsigned int symndx
, unsigned int got_type
) const = 0;
1330 // Set the GOT offset with a given type for a local symbol.
1332 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1333 unsigned int got_offset
) = 0;
1335 // Return whether local symbol SYMNDX is a TLS symbol.
1337 do_local_is_tls(unsigned int symndx
) const = 0;
1339 // Return the number of local symbols--implemented by child class.
1340 virtual unsigned int
1341 do_local_symbol_count() const = 0;
1343 // Return the number of output local symbols--implemented by child class.
1344 virtual unsigned int
1345 do_output_local_symbol_count() const = 0;
1347 // Return the file offset for local symbols--implemented by child class.
1349 do_local_symbol_offset() const = 0;
1351 // Count local symbols--implemented by child class.
1353 do_count_local_symbols(Stringpool_template
<char>*,
1354 Stringpool_template
<char>*) = 0;
1356 // Finalize the local symbols. Set the output symbol table indexes
1357 // for the local variables, and set the offset where local symbol
1358 // information will be stored.
1359 virtual unsigned int
1360 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
1362 // Set the output dynamic symbol table indexes for the local variables.
1363 virtual unsigned int
1364 do_set_local_dynsym_indexes(unsigned int) = 0;
1366 // Set the offset where local dynamic symbol information will be stored.
1367 virtual unsigned int
1368 do_set_local_dynsym_offset(off_t
) = 0;
1370 // Relocate the input sections and write out the local
1371 // symbols--implemented by child class.
1373 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
1375 // Set the offset of a section--implemented by child class.
1377 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
1379 // Layout sections whose layout was deferred while waiting for
1380 // input files from a plugin--implemented by child class.
1382 do_layout_deferred_sections(Layout
*) = 0;
1384 // Given a section index, return the corresponding Output_section.
1385 // The return value will be NULL if the section is not included in
1388 do_output_section(unsigned int shndx
) const
1390 gold_assert(shndx
< this->output_sections_
.size());
1391 return this->output_sections_
[shndx
];
1394 // Return the vector mapping input sections to output sections.
1397 { return this->output_sections_
; }
1399 const Output_sections
&
1400 output_sections() const
1401 { return this->output_sections_
; }
1403 // Set the size of the relocatable relocs array.
1405 size_relocatable_relocs()
1407 this->map_to_relocatable_relocs_
=
1408 new std::vector
<Relocatable_relocs
*>(this->shnum());
1411 // Record that we must wait for the output sections to be written
1412 // before applying relocations.
1414 set_relocs_must_follow_section_writes()
1415 { this->relocs_must_follow_section_writes_
= true; }
1417 // Allocate the array for counting incremental relocations.
1419 allocate_incremental_reloc_counts()
1421 unsigned int nsyms
= this->do_get_global_symbols()->size();
1422 this->reloc_counts_
= new unsigned int[nsyms
];
1423 gold_assert(this->reloc_counts_
!= NULL
);
1424 memset(this->reloc_counts_
, 0, nsyms
* sizeof(unsigned int));
1427 // Record a relocation in this object referencing global symbol SYMNDX.
1428 // Used for tracking incremental link information.
1430 count_incremental_reloc(unsigned int symndx
)
1432 unsigned int nsyms
= this->do_get_global_symbols()->size();
1433 gold_assert(symndx
< nsyms
);
1434 gold_assert(this->reloc_counts_
!= NULL
);
1435 ++this->reloc_counts_
[symndx
];
1438 // Finalize the incremental relocation information.
1440 finalize_incremental_relocs(Layout
* layout
, bool clear_counts
);
1442 // Return the index of the next relocation to be written for global symbol
1443 // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
1445 next_incremental_reloc_index(unsigned int symndx
)
1447 unsigned int nsyms
= this->do_get_global_symbols()->size();
1449 gold_assert(this->reloc_counts_
!= NULL
);
1450 gold_assert(this->reloc_bases_
!= NULL
);
1451 gold_assert(symndx
< nsyms
);
1453 unsigned int counter
= this->reloc_counts_
[symndx
]++;
1454 return this->reloc_bases_
[symndx
] + counter
;
1457 // Return the word size of the object file--
1458 // implemented by child class.
1460 do_elfsize() const = 0;
1462 // Return TRUE if this is a big-endian object file--
1463 // implemented by child class.
1465 do_is_big_endian() const = 0;
1468 // Mapping from input sections to output section.
1469 Output_sections output_sections_
;
1470 // Mapping from input section index to the information recorded for
1471 // the relocations. This is only used for a relocatable link.
1472 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
1473 // Mappings for merge sections. This is managed by the code in the
1475 Object_merge_map
* object_merge_map_
;
1476 // Whether we need to wait for output sections to be written before
1477 // we can apply relocations.
1478 bool relocs_must_follow_section_writes_
;
1479 // Used to store the relocs data computed by the Read_relocs pass.
1480 // Used during garbage collection of unused sections.
1481 Read_relocs_data
* rd_
;
1482 // Used to store the symbols data computed by the Read_symbols pass.
1483 // Again used during garbage collection when laying out referenced
1485 gold::Symbols_data
* sd_
;
1486 // Per-symbol counts of relocations, for incremental links.
1487 unsigned int* reloc_counts_
;
1488 // Per-symbol base indexes of relocations, for incremental links.
1489 unsigned int* reloc_bases_
;
1490 // Index of the first dynamic relocation for this object.
1491 unsigned int first_dyn_reloc_
;
1492 // Count of dynamic relocations for this object.
1493 unsigned int dyn_reloc_count_
;
1496 // This class is used to handle relocations against a section symbol
1497 // in an SHF_MERGE section. For such a symbol, we need to know the
1498 // addend of the relocation before we can determine the final value.
1499 // The addend gives us the location in the input section, and we can
1500 // determine how it is mapped to the output section. For a
1501 // non-section symbol, we apply the addend to the final value of the
1502 // symbol; that is done in finalize_local_symbols, and does not use
1506 class Merged_symbol_value
1509 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1511 // We use a hash table to map offsets in the input section to output
1513 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
1515 Merged_symbol_value(Value input_value
, Value output_start_address
)
1516 : input_value_(input_value
), output_start_address_(output_start_address
),
1520 // Initialize the hash table.
1522 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
1524 // Release the hash table to save space.
1526 free_input_to_output_map()
1527 { this->output_addresses_
.clear(); }
1529 // Get the output value corresponding to an addend. The object and
1530 // input section index are passed in because the caller will have
1531 // them; otherwise we could store them here.
1533 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
1535 // This is a relocation against a section symbol. ADDEND is the
1536 // offset in the section. The result should be the start of some
1537 // merge area. If the object file wants something else, it should
1538 // use a regular symbol rather than a section symbol.
1539 // Unfortunately, PR 6658 shows a case in which the object file
1540 // refers to the section symbol, but uses a negative ADDEND to
1541 // compensate for a PC relative reloc. We can't handle the
1542 // general case. However, we can handle the special case of a
1543 // negative addend, by assuming that it refers to the start of the
1544 // section. Of course, that means that we have to guess when
1545 // ADDEND is negative. It is normal to see a 32-bit value here
1546 // even when the template parameter size is 64, as 64-bit object
1547 // file formats have 32-bit relocations. We know this is a merge
1548 // section, so we know it has to fit into memory. So we assume
1549 // that we won't see a value larger than a large 32-bit unsigned
1550 // value. This will break objects with very very large merge
1551 // sections; they probably break in other ways anyhow.
1552 Value input_offset
= this->input_value_
;
1553 if (addend
< 0xffffff00)
1555 input_offset
+= addend
;
1558 typename
Output_addresses::const_iterator p
=
1559 this->output_addresses_
.find(input_offset
);
1560 if (p
!= this->output_addresses_
.end())
1561 return p
->second
+ addend
;
1563 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
1568 // Get the output value for an input offset if we couldn't find it
1569 // in the hash table.
1571 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
1572 Value input_offset
) const;
1574 // The value of the section symbol in the input file. This is
1575 // normally zero, but could in principle be something else.
1577 // The start address of this merged section in the output file.
1578 Value output_start_address_
;
1579 // A hash table which maps offsets in the input section to output
1580 // addresses. This only maps specific offsets, not all offsets.
1581 Output_addresses output_addresses_
;
1584 // This POD class is holds the value of a symbol. This is used for
1585 // local symbols, and for all symbols during relocation processing.
1586 // For special sections, such as SHF_MERGE sections, this calls a
1587 // function to get the final symbol value.
1593 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1596 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1597 is_ordinary_shndx_(false), is_section_symbol_(false),
1598 is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
1599 { this->u_
.value
= 0; }
1603 if (!this->has_output_value_
)
1604 delete this->u_
.merged_symbol_value
;
1607 // Get the value of this symbol. OBJECT is the object in which this
1608 // symbol is defined, and ADDEND is an addend to add to the value.
1609 template<bool big_endian
>
1611 value(const Sized_relobj_file
<size
, big_endian
>* object
, Value addend
) const
1613 if (this->has_output_value_
)
1614 return this->u_
.value
+ addend
;
1617 gold_assert(this->is_ordinary_shndx_
);
1618 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1623 // Set the value of this symbol in the output symbol table.
1625 set_output_value(Value value
)
1626 { this->u_
.value
= value
; }
1628 // For a section symbol in a merged section, we need more
1631 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1633 gold_assert(this->is_section_symbol_
);
1634 this->has_output_value_
= false;
1635 this->u_
.merged_symbol_value
= msv
;
1638 // Initialize the input to output map for a section symbol in a
1639 // merged section. We also initialize the value of a non-section
1640 // symbol in a merged section.
1642 initialize_input_to_output_map(const Relobj
* object
)
1644 if (!this->has_output_value_
)
1646 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1647 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1648 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1652 // Free the input to output map for a section symbol in a merged
1655 free_input_to_output_map()
1657 if (!this->has_output_value_
)
1658 this->u_
.merged_symbol_value
->free_input_to_output_map();
1661 // Set the value of the symbol from the input file. This is only
1662 // called by count_local_symbols, to communicate the value to
1663 // finalize_local_symbols.
1665 set_input_value(Value value
)
1666 { this->u_
.value
= value
; }
1668 // Return the input value. This is only called by
1669 // finalize_local_symbols and (in special cases) relocate_section.
1672 { return this->u_
.value
; }
1674 // Return whether we have set the index in the output symbol table
1677 is_output_symtab_index_set() const
1679 return (this->output_symtab_index_
!= 0
1680 && this->output_symtab_index_
!= -2U);
1683 // Return whether this symbol may be discarded from the normal
1686 may_be_discarded_from_output_symtab() const
1688 gold_assert(!this->is_output_symtab_index_set());
1689 return this->output_symtab_index_
!= -2U;
1692 // Return whether this symbol has an entry in the output symbol
1695 has_output_symtab_entry() const
1697 gold_assert(this->is_output_symtab_index_set());
1698 return this->output_symtab_index_
!= -1U;
1701 // Return the index in the output symbol table.
1703 output_symtab_index() const
1705 gold_assert(this->is_output_symtab_index_set()
1706 && this->output_symtab_index_
!= -1U);
1707 return this->output_symtab_index_
;
1710 // Set the index in the output symbol table.
1712 set_output_symtab_index(unsigned int i
)
1714 gold_assert(!this->is_output_symtab_index_set());
1715 gold_assert(i
!= 0 && i
!= -1U && i
!= -2U);
1716 this->output_symtab_index_
= i
;
1719 // Record that this symbol should not go into the output symbol
1722 set_no_output_symtab_entry()
1724 gold_assert(this->output_symtab_index_
== 0);
1725 this->output_symtab_index_
= -1U;
1728 // Record that this symbol must go into the output symbol table,
1729 // because it there is a relocation that uses it.
1731 set_must_have_output_symtab_entry()
1733 gold_assert(!this->is_output_symtab_index_set());
1734 this->output_symtab_index_
= -2U;
1737 // Set the index in the output dynamic symbol table.
1739 set_needs_output_dynsym_entry()
1741 gold_assert(!this->is_section_symbol());
1742 this->output_dynsym_index_
= 0;
1745 // Return whether this symbol should go into the dynamic symbol
1748 needs_output_dynsym_entry() const
1750 return this->output_dynsym_index_
!= -1U;
1753 // Return whether this symbol has an entry in the dynamic symbol
1756 has_output_dynsym_entry() const
1758 gold_assert(this->output_dynsym_index_
!= 0);
1759 return this->output_dynsym_index_
!= -1U;
1762 // Record that this symbol should go into the dynamic symbol table.
1764 set_output_dynsym_index(unsigned int i
)
1766 gold_assert(this->output_dynsym_index_
== 0);
1767 gold_assert(i
!= 0 && i
!= -1U);
1768 this->output_dynsym_index_
= i
;
1771 // Return the index in the output dynamic symbol table.
1773 output_dynsym_index() const
1775 gold_assert(this->output_dynsym_index_
!= 0
1776 && this->output_dynsym_index_
!= -1U);
1777 return this->output_dynsym_index_
;
1780 // Set the index of the input section in the input file.
1782 set_input_shndx(unsigned int i
, bool is_ordinary
)
1784 this->input_shndx_
= i
;
1785 // input_shndx_ field is a bitfield, so make sure that the value
1787 gold_assert(this->input_shndx_
== i
);
1788 this->is_ordinary_shndx_
= is_ordinary
;
1791 // Return the index of the input section in the input file.
1793 input_shndx(bool* is_ordinary
) const
1795 *is_ordinary
= this->is_ordinary_shndx_
;
1796 return this->input_shndx_
;
1799 // Whether this is a section symbol.
1801 is_section_symbol() const
1802 { return this->is_section_symbol_
; }
1804 // Record that this is a section symbol.
1806 set_is_section_symbol()
1808 gold_assert(!this->needs_output_dynsym_entry());
1809 this->is_section_symbol_
= true;
1812 // Record that this is a TLS symbol.
1815 { this->is_tls_symbol_
= true; }
1817 // Return true if this is a TLS symbol.
1819 is_tls_symbol() const
1820 { return this->is_tls_symbol_
; }
1822 // Record that this is an IFUNC symbol.
1824 set_is_ifunc_symbol()
1825 { this->is_ifunc_symbol_
= true; }
1827 // Return true if this is an IFUNC symbol.
1829 is_ifunc_symbol() const
1830 { return this->is_ifunc_symbol_
; }
1832 // Return true if this has output value.
1834 has_output_value() const
1835 { return this->has_output_value_
; }
1838 // The index of this local symbol in the output symbol table. This
1839 // will be 0 if no value has been assigned yet, and the symbol may
1840 // be omitted. This will be -1U if the symbol should not go into
1841 // the symbol table. This will be -2U if the symbol must go into
1842 // the symbol table, but no index has been assigned yet.
1843 unsigned int output_symtab_index_
;
1844 // The index of this local symbol in the dynamic symbol table. This
1845 // will be -1U if the symbol should not go into the symbol table.
1846 unsigned int output_dynsym_index_
;
1847 // The section index in the input file in which this symbol is
1849 unsigned int input_shndx_
: 27;
1850 // Whether the section index is an ordinary index, not a special
1852 bool is_ordinary_shndx_
: 1;
1853 // Whether this is a STT_SECTION symbol.
1854 bool is_section_symbol_
: 1;
1855 // Whether this is a STT_TLS symbol.
1856 bool is_tls_symbol_
: 1;
1857 // Whether this is a STT_GNU_IFUNC symbol.
1858 bool is_ifunc_symbol_
: 1;
1859 // Whether this symbol has a value for the output file. This is
1860 // normally set to true during Layout::finalize, by
1861 // finalize_local_symbols. It will be false for a section symbol in
1862 // a merge section, as for such symbols we can not determine the
1863 // value to use in a relocation until we see the addend.
1864 bool has_output_value_
: 1;
1867 // This is used if has_output_value_ is true. Between
1868 // count_local_symbols and finalize_local_symbols, this is the
1869 // value in the input file. After finalize_local_symbols, it is
1870 // the value in the output file.
1872 // This is used if has_output_value_ is false. It points to the
1873 // information we need to get the value for a merge section.
1874 Merged_symbol_value
<size
>* merged_symbol_value
;
1878 // This type is used to modify relocations for -fsplit-stack. It is
1879 // indexed by relocation index, and means that the relocation at that
1880 // index should use the symbol from the vector, rather than the one
1881 // indicated by the relocation.
1883 class Reloc_symbol_changes
1886 Reloc_symbol_changes(size_t count
)
1891 set(size_t i
, Symbol
* sym
)
1892 { this->vec_
[i
] = sym
; }
1895 operator[](size_t i
) const
1896 { return this->vec_
[i
]; }
1899 std::vector
<Symbol
*> vec_
;
1902 // Abstract base class for a regular object file, either a real object file
1903 // or an incremental (unchanged) object. This is size and endian specific.
1905 template<int size
, bool big_endian
>
1906 class Sized_relobj
: public Relobj
1909 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1910 typedef Relobj::Symbols Symbols
;
1912 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1914 Sized_relobj(const std::string
& name
, Input_file
* input_file
)
1915 : Relobj(name
, input_file
), local_got_offsets_(), section_offsets_()
1918 Sized_relobj(const std::string
& name
, Input_file
* input_file
,
1920 : Relobj(name
, input_file
, offset
), local_got_offsets_(), section_offsets_()
1926 // If this is a regular object, return a pointer to the Sized_relobj_file
1927 // object. Otherwise, return NULL.
1928 virtual Sized_relobj_file
<size
, big_endian
>*
1932 const virtual Sized_relobj_file
<size
, big_endian
>*
1933 sized_relobj() const
1936 // Checks if the offset of input section SHNDX within its output
1937 // section is invalid.
1939 is_output_section_offset_invalid(unsigned int shndx
) const
1940 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1942 // Get the offset of input section SHNDX within its output section.
1943 // This is -1 if the input section requires a special mapping, such
1944 // as a merge section. The output section can be found in the
1945 // output_sections_ field of the parent class Relobj.
1947 get_output_section_offset(unsigned int shndx
) const
1949 gold_assert(shndx
< this->section_offsets_
.size());
1950 return this->section_offsets_
[shndx
];
1953 // Iterate over local symbols, calling a visitor class V for each GOT offset
1954 // associated with a local symbol.
1956 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const;
1959 typedef Relobj::Output_sections Output_sections
;
1961 // Clear the local symbol information.
1964 { this->local_got_offsets_
.clear(); }
1966 // Return the vector of section offsets.
1967 std::vector
<Address
>&
1969 { return this->section_offsets_
; }
1971 // Get the address of an output section.
1973 do_output_section_address(unsigned int shndx
);
1975 // Get the offset of a section.
1977 do_output_section_offset(unsigned int shndx
) const
1979 Address off
= this->get_output_section_offset(shndx
);
1980 if (off
== invalid_address
)
1985 // Set the offset of a section.
1987 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1989 gold_assert(shndx
< this->section_offsets_
.size());
1990 this->section_offsets_
[shndx
] =
1991 (off
== static_cast<uint64_t>(-1)
1993 : convert_types
<Address
, uint64_t>(off
));
1996 // Return whether the local symbol SYMNDX has a GOT offset of type
1999 do_local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
2001 Local_got_offsets::const_iterator p
=
2002 this->local_got_offsets_
.find(symndx
);
2003 return (p
!= this->local_got_offsets_
.end()
2004 && p
->second
->get_offset(got_type
) != -1U);
2007 // Return the GOT offset of type GOT_TYPE of the local symbol
2010 do_local_got_offset(unsigned int symndx
, unsigned int got_type
) const
2012 Local_got_offsets::const_iterator p
=
2013 this->local_got_offsets_
.find(symndx
);
2014 gold_assert(p
!= this->local_got_offsets_
.end());
2015 unsigned int off
= p
->second
->get_offset(got_type
);
2016 gold_assert(off
!= -1U);
2020 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
2023 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
2024 unsigned int got_offset
)
2026 Local_got_offsets::const_iterator p
=
2027 this->local_got_offsets_
.find(symndx
);
2028 if (p
!= this->local_got_offsets_
.end())
2029 p
->second
->set_offset(got_type
, got_offset
);
2032 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
2033 std::pair
<Local_got_offsets::iterator
, bool> ins
=
2034 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
2035 gold_assert(ins
.second
);
2039 // Return the word size of the object file.
2044 // Return TRUE if this is a big-endian object file.
2046 do_is_big_endian() const
2047 { return big_endian
; }
2050 // The GOT offsets of local symbols. This map also stores GOT offsets
2051 // for tp-relative offsets for TLS symbols.
2052 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
2054 // GOT offsets for local non-TLS symbols, and tp-relative offsets
2055 // for TLS symbols, indexed by symbol number.
2056 Local_got_offsets local_got_offsets_
;
2057 // For each input section, the offset of the input section in its
2058 // output section. This is INVALID_ADDRESS if the input section requires a
2060 std::vector
<Address
> section_offsets_
;
2063 // A regular object file. This is size and endian specific.
2065 template<int size
, bool big_endian
>
2066 class Sized_relobj_file
: public Sized_relobj
<size
, big_endian
>
2069 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
2070 typedef typename Sized_relobj
<size
, big_endian
>::Symbols Symbols
;
2071 typedef std::vector
<Symbol_value
<size
> > Local_values
;
2073 static const Address invalid_address
= static_cast<Address
>(0) - 1;
2075 enum Compute_final_local_value_status
2079 // An error occurred.
2081 // The local symbol has no output section.
2085 Sized_relobj_file(const std::string
& name
,
2086 Input_file
* input_file
,
2088 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
2090 ~Sized_relobj_file();
2092 // Set up the object file based on TARGET.
2095 { this->do_setup(); }
2097 // Return a pointer to the Sized_relobj_file object.
2098 Sized_relobj_file
<size
, big_endian
>*
2102 const Sized_relobj_file
<size
, big_endian
>*
2103 sized_relobj() const
2106 // Return the ELF file type.
2109 { return this->e_type_
; }
2111 // Return the number of symbols. This is only valid after
2112 // Object::add_symbols has been called.
2114 symbol_count() const
2115 { return this->local_symbol_count_
+ this->symbols_
.size(); }
2117 // If SYM is the index of a global symbol in the object file's
2118 // symbol table, return the Symbol object. Otherwise, return NULL.
2120 global_symbol(unsigned int sym
) const
2122 if (sym
>= this->local_symbol_count_
)
2124 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
2125 return this->symbols_
[sym
- this->local_symbol_count_
];
2130 // Return the section index of symbol SYM. Set *VALUE to its value
2131 // in the object file. Set *IS_ORDINARY if this is an ordinary
2132 // section index, not a special code between SHN_LORESERVE and
2133 // SHN_HIRESERVE. Note that for a symbol which is not defined in
2134 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
2135 // it will not return the final value of the symbol in the link.
2137 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
2139 // Return a pointer to the Symbol_value structure which holds the
2140 // value of a local symbol.
2141 const Symbol_value
<size
>*
2142 local_symbol(unsigned int sym
) const
2144 gold_assert(sym
< this->local_values_
.size());
2145 return &this->local_values_
[sym
];
2148 // Return the index of local symbol SYM in the ordinary symbol
2149 // table. A value of -1U means that the symbol is not being output.
2151 symtab_index(unsigned int sym
) const
2153 gold_assert(sym
< this->local_values_
.size());
2154 return this->local_values_
[sym
].output_symtab_index();
2157 // Return the index of local symbol SYM in the dynamic symbol
2158 // table. A value of -1U means that the symbol is not being output.
2160 dynsym_index(unsigned int sym
) const
2162 gold_assert(sym
< this->local_values_
.size());
2163 return this->local_values_
[sym
].output_dynsym_index();
2166 // Return the input section index of local symbol SYM.
2168 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
2170 gold_assert(sym
< this->local_values_
.size());
2171 return this->local_values_
[sym
].input_shndx(is_ordinary
);
2174 // Record that local symbol SYM must be in the output symbol table.
2176 set_must_have_output_symtab_entry(unsigned int sym
)
2178 gold_assert(sym
< this->local_values_
.size());
2179 this->local_values_
[sym
].set_must_have_output_symtab_entry();
2182 // Record that local symbol SYM needs a dynamic symbol entry.
2184 set_needs_output_dynsym_entry(unsigned int sym
)
2186 gold_assert(sym
< this->local_values_
.size());
2187 this->local_values_
[sym
].set_needs_output_dynsym_entry();
2190 // Return whether the local symbol SYMNDX has a PLT offset.
2192 local_has_plt_offset(unsigned int symndx
) const;
2194 // Set the PLT offset of the local symbol SYMNDX.
2196 set_local_plt_offset(unsigned int symndx
, unsigned int plt_offset
);
2198 // Adjust this local symbol value. Return false if the symbol
2199 // should be discarded from the output file.
2201 adjust_local_symbol(Symbol_value
<size
>* lv
) const
2202 { return this->do_adjust_local_symbol(lv
); }
2204 // Return the name of the symbol that spans the given offset in the
2205 // specified section in this object. This is used only for error
2206 // messages and is not particularly efficient.
2208 get_symbol_location_info(unsigned int shndx
, off_t offset
,
2209 Symbol_location_info
* info
);
2211 // Look for a kept section corresponding to the given discarded section,
2212 // and return its output address. This is used only for relocations in
2213 // debugging sections.
2215 map_to_kept_section(unsigned int shndx
, bool* found
) const;
2217 // Compute final local symbol value. R_SYM is the local symbol index.
2218 // LV_IN points to a local symbol value containing the input value.
2219 // LV_OUT points to a local symbol value storing the final output value,
2220 // which must not be a merged symbol value since before calling this
2221 // method to avoid memory leak. SYMTAB points to a symbol table.
2223 // The method returns a status code at return. If the return status is
2224 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2225 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2226 // *LV_OUT is not modified.
2227 Compute_final_local_value_status
2228 compute_final_local_value(unsigned int r_sym
,
2229 const Symbol_value
<size
>* lv_in
,
2230 Symbol_value
<size
>* lv_out
,
2231 const Symbol_table
* symtab
);
2233 // Return true if the layout for this object was deferred.
2234 bool is_deferred_layout() const
2235 { return this->is_deferred_layout_
; }
2238 typedef typename Sized_relobj
<size
, big_endian
>::Output_sections
2245 // Read the symbols.
2247 do_read_symbols(Read_symbols_data
*);
2249 // Read the symbols. This is common code for all target-specific
2250 // overrides of do_read_symbols.
2252 base_read_symbols(Read_symbols_data
*);
2254 // Return the value of a local symbol.
2256 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const
2258 const Symbol_value
<size
>* symval
= this->local_symbol(symndx
);
2259 return symval
->value(this, addend
);
2262 // Return the PLT offset for a local symbol. It is an error to call
2263 // this if it doesn't have one.
2265 do_local_plt_offset(unsigned int symndx
) const;
2267 // Return whether local symbol SYMNDX is a TLS symbol.
2269 do_local_is_tls(unsigned int symndx
) const
2270 { return this->local_symbol(symndx
)->is_tls_symbol(); }
2272 // Return the number of local symbols.
2274 do_local_symbol_count() const
2275 { return this->local_symbol_count_
; }
2277 // Return the number of local symbols in the output symbol table.
2279 do_output_local_symbol_count() const
2280 { return this->output_local_symbol_count_
; }
2282 // Return the number of local symbols in the output symbol table.
2284 do_local_symbol_offset() const
2285 { return this->local_symbol_offset_
; }
2287 // Lay out the input sections.
2289 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
2291 // Layout sections whose layout was deferred while waiting for
2292 // input files from a plugin.
2294 do_layout_deferred_sections(Layout
*);
2296 // Add the symbols to the symbol table.
2298 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
2300 Archive::Should_include
2301 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
2304 // Iterate over global symbols, calling a visitor class V for each.
2306 do_for_all_global_symbols(Read_symbols_data
* sd
,
2307 Library_base::Symbol_visitor_base
* v
);
2311 do_read_relocs(Read_relocs_data
*);
2313 // Process the relocs to find list of referenced sections. Used only
2314 // during garbage collection.
2316 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2318 // Scan the relocs and adjust the symbol table.
2320 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2322 // Count the local symbols.
2324 do_count_local_symbols(Stringpool_template
<char>*,
2325 Stringpool_template
<char>*);
2327 // Finalize the local symbols.
2329 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
2331 // Set the offset where local dynamic symbol information will be stored.
2333 do_set_local_dynsym_indexes(unsigned int);
2335 // Set the offset where local dynamic symbol information will be stored.
2337 do_set_local_dynsym_offset(off_t
);
2339 // Relocate the input sections and write out the local symbols.
2341 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
2343 // Get the size of a section.
2345 do_section_size(unsigned int shndx
)
2346 { return this->elf_file_
.section_size(shndx
); }
2348 // Get the name of a section.
2350 do_section_name(unsigned int shndx
) const
2351 { return this->elf_file_
.section_name(shndx
); }
2353 // Return the location of the contents of a section.
2354 const unsigned char*
2355 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
2358 Object::Location
loc(this->elf_file_
.section_contents(shndx
));
2359 *plen
= convert_to_section_size_type(loc
.data_size
);
2362 static const unsigned char empty
[1] = { '\0' };
2365 return this->get_view(loc
.file_offset
, *plen
, true, cache
);
2368 // Return section flags.
2370 do_section_flags(unsigned int shndx
);
2372 // Return section entsize.
2374 do_section_entsize(unsigned int shndx
);
2376 // Return section address.
2378 do_section_address(unsigned int shndx
)
2379 { return this->elf_file_
.section_addr(shndx
); }
2381 // Return section type.
2383 do_section_type(unsigned int shndx
)
2384 { return this->elf_file_
.section_type(shndx
); }
2386 // Return the section link field.
2388 do_section_link(unsigned int shndx
)
2389 { return this->elf_file_
.section_link(shndx
); }
2391 // Return the section info field.
2393 do_section_info(unsigned int shndx
)
2394 { return this->elf_file_
.section_info(shndx
); }
2396 // Return the section alignment.
2398 do_section_addralign(unsigned int shndx
)
2399 { return this->elf_file_
.section_addralign(shndx
); }
2401 // Return the Xindex structure to use.
2403 do_initialize_xindex();
2405 // Get symbol counts.
2407 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
2409 // Get the global symbols.
2411 do_get_global_symbols() const
2412 { return &this->symbols_
; }
2414 // Adjust a section index if necessary.
2416 adjust_shndx(unsigned int shndx
)
2418 if (shndx
>= elfcpp::SHN_LORESERVE
)
2419 shndx
+= this->elf_file_
.large_shndx_offset();
2423 // Initialize input to output maps for section symbols in merged
2426 initialize_input_to_output_maps();
2428 // Free the input to output maps for section symbols in merged
2431 free_input_to_output_maps();
2433 // Return symbol table section index.
2435 symtab_shndx() const
2436 { return this->symtab_shndx_
; }
2438 // Allow a child class to access the ELF file.
2439 elfcpp::Elf_file
<size
, big_endian
, Object
>*
2441 { return &this->elf_file_
; }
2443 // Allow a child class to access the local values.
2446 { return &this->local_values_
; }
2448 // Views and sizes when relocating.
2451 unsigned char* view
;
2452 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
2454 section_size_type view_size
;
2455 bool is_input_output_view
;
2456 bool is_postprocessing_view
;
2457 bool is_ctors_reverse_view
;
2460 typedef std::vector
<View_size
> Views
;
2462 // Stash away info for a number of special sections.
2463 // Return true if any of the sections found require local symbols to be read.
2465 do_find_special_sections(Read_symbols_data
* sd
);
2467 // This may be overriden by a child class.
2469 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2470 const unsigned char* pshdrs
, Output_file
* of
,
2473 // Adjust this local symbol value. Return false if the symbol
2474 // should be discarded from the output file.
2476 do_adjust_local_symbol(Symbol_value
<size
>*) const
2479 // Allow a child to set output local symbol count.
2481 set_output_local_symbol_count(unsigned int value
)
2482 { this->output_local_symbol_count_
= value
; }
2486 typedef Sized_relobj_file
<size
, big_endian
> This
;
2487 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
2488 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2489 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2490 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
2492 // To keep track of discarded comdat sections, we need to map a member
2493 // section index to the object and section index of the corresponding
2495 struct Kept_comdat_section
2497 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
2498 : object(a_object
), shndx(a_shndx
)
2503 typedef std::map
<unsigned int, Kept_comdat_section
>
2504 Kept_comdat_section_table
;
2506 // Find the SHT_SYMTAB section, given the section headers.
2508 find_symtab(const unsigned char* pshdrs
);
2510 // Return whether SHDR has the right flags for a GNU style exception
2513 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
2515 // Return whether there is a section named .eh_frame which might be
2516 // a GNU style exception frame section.
2518 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
2519 section_size_type names_size
) const;
2521 // Whether to include a section group in the link.
2523 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
2524 const unsigned char*, const char*, section_size_type
,
2525 std::vector
<bool>*);
2527 // Whether to include a linkonce section in the link.
2529 include_linkonce_section(Layout
*, unsigned int, const char*,
2530 const elfcpp::Shdr
<size
, big_endian
>&);
2532 // Layout an input section.
2534 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
2535 const typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
2536 unsigned int reloc_type
);
2538 // Layout an input .eh_frame section.
2540 layout_eh_frame_section(Layout
* layout
, const unsigned char* symbols_data
,
2541 section_size_type symbols_size
,
2542 const unsigned char* symbol_names_data
,
2543 section_size_type symbol_names_size
,
2544 unsigned int shndx
, const typename
This::Shdr
&,
2545 unsigned int reloc_shndx
, unsigned int reloc_type
);
2547 // Write section data to the output file. Record the views and
2548 // sizes in VIEWS for use when relocating.
2550 write_sections(const Layout
*, const unsigned char* pshdrs
, Output_file
*,
2553 // Relocate the sections in the output file.
2555 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2556 const unsigned char* pshdrs
, Output_file
* of
,
2558 { this->do_relocate_sections(symtab
, layout
, pshdrs
, of
, pviews
); }
2560 // Reverse the words in a section. Used for .ctors sections mapped
2561 // to .init_array sections.
2563 reverse_words(unsigned char*, section_size_type
);
2565 // Scan the input relocations for --emit-relocs.
2567 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
2568 const Read_relocs_data::Relocs_list::iterator
&);
2570 // Scan the input relocations for --emit-relocs, templatized on the
2571 // type of the relocation section.
2572 template<int sh_type
>
2574 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
2575 const unsigned char* plocal_syms
,
2576 const Read_relocs_data::Relocs_list::iterator
&,
2577 Relocatable_relocs
*);
2579 // Scan the input relocations for --incremental.
2581 incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator
&);
2583 // Scan the input relocations for --incremental, templatized on the
2584 // type of the relocation section.
2585 template<int sh_type
>
2587 incremental_relocs_scan_reltype(
2588 const Read_relocs_data::Relocs_list::iterator
&);
2591 incremental_relocs_write(const Relocate_info
<size
, big_endian
>*,
2592 unsigned int sh_type
,
2593 const unsigned char* prelocs
,
2596 Address output_offset
,
2599 template<int sh_type
>
2601 incremental_relocs_write_reltype(const Relocate_info
<size
, big_endian
>*,
2602 const unsigned char* prelocs
,
2605 Address output_offset
,
2608 // A type shared by split_stack_adjust_reltype and find_functions.
2609 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
2611 // Check for -fsplit-stack routines calling non-split-stack routines.
2613 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
2614 unsigned int sh_type
, unsigned int shndx
,
2615 const unsigned char* prelocs
, size_t reloc_count
,
2616 unsigned char* view
, section_size_type view_size
,
2617 Reloc_symbol_changes
** reloc_map
);
2619 template<int sh_type
>
2621 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
2622 unsigned int shndx
, const unsigned char* prelocs
,
2623 size_t reloc_count
, unsigned char* view
,
2624 section_size_type view_size
,
2625 Reloc_symbol_changes
** reloc_map
);
2627 // Find all functions in a section.
2629 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
2632 // Write out the local symbols.
2634 write_local_symbols(Output_file
*,
2635 const Stringpool_template
<char>*,
2636 const Stringpool_template
<char>*,
2637 Output_symtab_xindex
*,
2638 Output_symtab_xindex
*,
2641 // Record a mapping from discarded section SHNDX to the corresponding
2644 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
2645 unsigned int kept_shndx
)
2647 Kept_comdat_section
kept(kept_object
, kept_shndx
);
2648 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
2651 // Find the kept section corresponding to the discarded section
2652 // SHNDX. Return true if found.
2654 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
2655 unsigned int* kept_shndx
) const
2657 typename
Kept_comdat_section_table::const_iterator p
=
2658 this->kept_comdat_sections_
.find(shndx
);
2659 if (p
== this->kept_comdat_sections_
.end())
2661 *kept_object
= p
->second
.object
;
2662 *kept_shndx
= p
->second
.shndx
;
2666 // Compute final local symbol value. R_SYM is the local symbol index.
2667 // LV_IN points to a local symbol value containing the input value.
2668 // LV_OUT points to a local symbol value storing the final output value,
2669 // which must not be a merged symbol value since before calling this
2670 // method to avoid memory leak. RELOCATABLE indicates whether we are
2671 // linking a relocatable output. OUT_SECTIONS is an array of output
2672 // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
2673 // points to a symbol table.
2675 // The method returns a status code at return. If the return status is
2676 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2677 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2678 // *LV_OUT is not modified.
2679 inline Compute_final_local_value_status
2680 compute_final_local_value_internal(unsigned int r_sym
,
2681 const Symbol_value
<size
>* lv_in
,
2682 Symbol_value
<size
>* lv_out
,
2684 const Output_sections
& out_sections
,
2685 const std::vector
<Address
>& out_offsets
,
2686 const Symbol_table
* symtab
);
2688 // The PLT offsets of local symbols.
2689 typedef Unordered_map
<unsigned int, unsigned int> Local_plt_offsets
;
2691 // Saved information for sections whose layout was deferred.
2692 struct Deferred_layout
2694 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2695 Deferred_layout(unsigned int shndx
, const char* name
,
2696 const unsigned char* pshdr
,
2697 unsigned int reloc_shndx
, unsigned int reloc_type
)
2698 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
2699 reloc_type_(reloc_type
)
2701 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
2703 unsigned int shndx_
;
2705 unsigned int reloc_shndx_
;
2706 unsigned int reloc_type_
;
2707 unsigned char shdr_data_
[shdr_size
];
2710 // General access to the ELF file.
2711 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
2712 // Type of ELF file (ET_REL or ET_EXEC). ET_EXEC files are allowed
2713 // as input files only for the --just-symbols option.
2715 // Index of SHT_SYMTAB section.
2716 unsigned int symtab_shndx_
;
2717 // The number of local symbols.
2718 unsigned int local_symbol_count_
;
2719 // The number of local symbols which go into the output file.
2720 unsigned int output_local_symbol_count_
;
2721 // The number of local symbols which go into the output file's dynamic
2723 unsigned int output_local_dynsym_count_
;
2724 // The entries in the symbol table for the external symbols.
2726 // Number of symbols defined in object file itself.
2727 size_t defined_count_
;
2728 // File offset for local symbols (relative to start of symbol table).
2729 off_t local_symbol_offset_
;
2730 // File offset for local dynamic symbols (absolute).
2731 off_t local_dynsym_offset_
;
2732 // Values of local symbols.
2733 Local_values local_values_
;
2734 // PLT offsets for local symbols.
2735 Local_plt_offsets local_plt_offsets_
;
2736 // Table mapping discarded comdat sections to corresponding kept sections.
2737 Kept_comdat_section_table kept_comdat_sections_
;
2738 // Whether this object has a GNU style .eh_frame section.
2740 // If this object has a GNU style .eh_frame section that is discarded in
2741 // output, record the index here. Otherwise it is -1U.
2742 unsigned int discarded_eh_frame_shndx_
;
2743 // True if the layout of this object was deferred, waiting for plugin
2744 // replacement files.
2745 bool is_deferred_layout_
;
2746 // The list of sections whose layout was deferred.
2747 std::vector
<Deferred_layout
> deferred_layout_
;
2748 // The list of relocation sections whose layout was deferred.
2749 std::vector
<Deferred_layout
> deferred_layout_relocs_
;
2752 // A class to manage the list of all objects.
2758 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
2761 // The type of the list of input relocateable objects.
2762 typedef std::vector
<Relobj
*> Relobj_list
;
2763 typedef Relobj_list::const_iterator Relobj_iterator
;
2765 // The type of the list of input dynamic objects.
2766 typedef std::vector
<Dynobj
*> Dynobj_list
;
2767 typedef Dynobj_list::const_iterator Dynobj_iterator
;
2769 // Add an object to the list. Return true if all is well, or false
2770 // if this object should be ignored.
2772 add_object(Object
*);
2774 // Start processing an archive.
2776 archive_start(Archive
*);
2778 // Stop processing an archive.
2780 archive_stop(Archive
*);
2782 // For each dynamic object, check whether we've seen all of its
2783 // explicit dependencies.
2785 check_dynamic_dependencies() const;
2787 // Return whether an object was found in the system library
2790 found_in_system_library_directory(const Object
*) const;
2792 // Print symbol counts.
2794 print_symbol_counts(const Symbol_table
*) const;
2796 // Print a cross reference table.
2798 print_cref(const Symbol_table
*, FILE*) const;
2800 // Iterate over all regular objects.
2803 relobj_begin() const
2804 { return this->relobj_list_
.begin(); }
2808 { return this->relobj_list_
.end(); }
2810 // Iterate over all dynamic objects.
2813 dynobj_begin() const
2814 { return this->dynobj_list_
.begin(); }
2818 { return this->dynobj_list_
.end(); }
2820 // Return whether we have seen any dynamic objects.
2823 { return !this->dynobj_list_
.empty(); }
2825 // Return the number of non dynamic objects.
2827 number_of_relobjs() const
2828 { return this->relobj_list_
.size(); }
2830 // Return the number of input objects.
2832 number_of_input_objects() const
2833 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
2836 Input_objects(const Input_objects
&);
2837 Input_objects
& operator=(const Input_objects
&);
2839 // The list of ordinary objects included in the link.
2840 Relobj_list relobj_list_
;
2841 // The list of dynamic objects included in the link.
2842 Dynobj_list dynobj_list_
;
2843 // SONAMEs that we have seen.
2844 Unordered_map
<std::string
, Object
*> sonames_
;
2845 // Manage cross-references if requested.
2849 // Some of the information we pass to the relocation routines. We
2850 // group this together to avoid passing a dozen different arguments.
2852 template<int size
, bool big_endian
>
2853 struct Relocate_info
2856 const Symbol_table
* symtab
;
2858 const Layout
* layout
;
2859 // Object being relocated.
2860 Sized_relobj_file
<size
, big_endian
>* object
;
2861 // Section index of relocation section.
2862 unsigned int reloc_shndx
;
2863 // Section header of relocation section.
2864 const unsigned char* reloc_shdr
;
2865 // Section index of section being relocated.
2866 unsigned int data_shndx
;
2867 // Section header of data section.
2868 const unsigned char* data_shdr
;
2870 // Return a string showing the location of a relocation. This is
2871 // only used for error messages.
2873 location(size_t relnum
, off_t reloffset
) const;
2876 // This is used to represent a section in an object and is used as the
2877 // key type for various section maps.
2878 typedef std::pair
<Relobj
*, unsigned int> Section_id
;
2880 // This is similar to Section_id but is used when the section
2881 // pointers are const.
2882 typedef std::pair
<const Relobj
*, unsigned int> Const_section_id
;
2884 // The hash value is based on the address of an object in memory during
2885 // linking. It is okay to use this for looking up sections but never use
2886 // this in an unordered container that we want to traverse in a repeatable
2889 struct Section_id_hash
2891 size_t operator()(const Section_id
& loc
) const
2892 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2895 struct Const_section_id_hash
2897 size_t operator()(const Const_section_id
& loc
) const
2898 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2901 // Return whether INPUT_FILE contains an ELF object start at file
2902 // offset OFFSET. This sets *START to point to a view of the start of
2903 // the file. It sets *READ_SIZE to the number of bytes in the view.
2906 is_elf_object(Input_file
* input_file
, off_t offset
,
2907 const unsigned char** start
, int* read_size
);
2909 // Return an Object appropriate for the input file. P is BYTES long,
2910 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2911 // this sees an object the linker is not configured to support, it
2912 // sets *PUNCONFIGURED to true and returns NULL without giving an
2916 make_elf_object(const std::string
& name
, Input_file
*,
2917 off_t offset
, const unsigned char* p
,
2918 section_offset_type bytes
, bool* punconfigured
);
2920 } // end namespace gold
2922 #endif // !defined(GOLD_OBJECT_H)