1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
30 #include "elfcpp_file.h"
37 class General_options
;
44 class Output_symtab_xindex
;
47 class Object_merge_map
;
48 class Relocatable_relocs
;
51 template<typename Stringpool_char
>
52 class Stringpool_template
;
54 // Data to pass from read_symbols() to add_symbols().
56 struct Read_symbols_data
59 File_view
* section_headers
;
61 File_view
* section_names
;
62 // Size of section name data in bytes.
63 section_size_type section_names_size
;
66 // Size of symbol data in bytes.
67 section_size_type symbols_size
;
68 // Offset of external symbols within symbol data. This structure
69 // sometimes contains only external symbols, in which case this will
70 // be zero. Sometimes it contains all symbols.
71 section_offset_type external_symbols_offset
;
73 File_view
* symbol_names
;
74 // Size of symbol name data in bytes.
75 section_size_type symbol_names_size
;
77 // Version information. This is only used on dynamic objects.
78 // Version symbol data (from SHT_GNU_versym section).
80 section_size_type versym_size
;
81 // Version definition data (from SHT_GNU_verdef section).
83 section_size_type verdef_size
;
84 unsigned int verdef_info
;
85 // Needed version data (from SHT_GNU_verneed section).
87 section_size_type verneed_size
;
88 unsigned int verneed_info
;
91 // Information used to print error messages.
93 struct Symbol_location_info
95 std::string source_file
;
96 std::string enclosing_symbol_name
;
100 // Data about a single relocation section. This is read in
101 // read_relocs and processed in scan_relocs.
103 struct Section_relocs
105 // Index of reloc section.
106 unsigned int reloc_shndx
;
107 // Index of section that relocs apply to.
108 unsigned int data_shndx
;
109 // Contents of reloc section.
111 // Reloc section type.
112 unsigned int sh_type
;
113 // Number of reloc entries.
116 Output_section
* output_section
;
117 // Whether this section has special handling for offsets.
118 bool needs_special_offset_handling
;
119 // Whether the data section is allocated (has the SHF_ALLOC flag set).
120 bool is_data_section_allocated
;
123 // Relocations in an object file. This is read in read_relocs and
124 // processed in scan_relocs.
126 struct Read_relocs_data
128 typedef std::vector
<Section_relocs
> Relocs_list
;
131 // The local symbols.
132 File_view
* local_symbols
;
135 // The Xindex class manages section indexes for objects with more than
141 Xindex(int large_shndx_offset
)
142 : large_shndx_offset_(large_shndx_offset
), symtab_xindex_()
145 // Initialize the symtab_xindex_ array, given the object and the
146 // section index of the symbol table to use.
147 template<int size
, bool big_endian
>
149 initialize_symtab_xindex(Object
*, unsigned int symtab_shndx
);
151 // Read in the symtab_xindex_ array, given its section index.
152 // PSHDRS may optionally point to the section headers.
153 template<int size
, bool big_endian
>
155 read_symtab_xindex(Object
*, unsigned int xindex_shndx
,
156 const unsigned char* pshdrs
);
158 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
159 // real section index.
161 sym_xindex_to_shndx(Object
* object
, unsigned int symndx
);
164 // The type of the array giving the real section index for symbols
165 // whose st_shndx field holds SHN_XINDEX.
166 typedef std::vector
<unsigned int> Symtab_xindex
;
168 // Adjust a section index if necessary. This should only be called
169 // for ordinary section indexes.
171 adjust_shndx(unsigned int shndx
)
173 if (shndx
>= elfcpp::SHN_LORESERVE
)
174 shndx
+= this->large_shndx_offset_
;
178 // Adjust to apply to large section indexes.
179 int large_shndx_offset_
;
180 // The data from the SHT_SYMTAB_SHNDX section.
181 Symtab_xindex symtab_xindex_
;
184 // Object is an abstract base class which represents either a 32-bit
185 // or a 64-bit input object. This can be a regular object file
186 // (ET_REL) or a shared object (ET_DYN).
191 // NAME is the name of the object as we would report it to the user
192 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
193 // used to read the file. OFFSET is the offset within the input
194 // file--0 for a .o or .so file, something else for a .a file.
195 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
197 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
198 is_dynamic_(is_dynamic
), xindex_(NULL
), no_export_(false)
199 { input_file
->file().add_object(); }
202 { this->input_file_
->file().remove_object(); }
204 // Return the name of the object as we would report it to the tuser.
207 { return this->name_
; }
209 // Get the offset into the file.
212 { return this->offset_
; }
214 // Return whether this is a dynamic object.
217 { return this->is_dynamic_
; }
219 // Returns NULL for Objects that are not plugin objects. This method
220 // is overridden in the Pluginobj class.
223 { return this->do_pluginobj(); }
225 // Get the file. We pass on const-ness.
228 { return this->input_file_
; }
232 { return this->input_file_
; }
234 // Lock the underlying file.
237 { this->input_file()->file().lock(t
); }
239 // Unlock the underlying file.
241 unlock(const Task
* t
)
242 { this->input_file()->file().unlock(t
); }
244 // Return whether the underlying file is locked.
247 { return this->input_file()->file().is_locked(); }
249 // Return the token, so that the task can be queued.
252 { return this->input_file()->file().token(); }
254 // Release the underlying file.
257 { this->input_file_
->file().release(); }
259 // Return whether we should just read symbols from this file.
262 { return this->input_file()->just_symbols(); }
264 // Get the number of sections.
267 { return this->shnum_
; }
269 // Return a view of the contents of a section. Set *PLEN to the
270 // size. CACHE is a hint as in File_read::get_view.
272 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
274 // Adjust a symbol's section index as needed. SYMNDX is the index
275 // of the symbol and SHNDX is the symbol's section from
276 // get_st_shndx. This returns the section index. It sets
277 // *IS_ORDINARY to indicate whether this is a normal section index,
278 // rather than a special code between SHN_LORESERVE and
281 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
283 if (shndx
< elfcpp::SHN_LORESERVE
)
285 else if (shndx
== elfcpp::SHN_XINDEX
)
287 if (this->xindex_
== NULL
)
288 this->xindex_
= this->do_initialize_xindex();
289 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
293 *is_ordinary
= false;
297 // Return the size of a section given a section index.
299 section_size(unsigned int shndx
)
300 { return this->do_section_size(shndx
); }
302 // Return the name of a section given a section index.
304 section_name(unsigned int shndx
)
305 { return this->do_section_name(shndx
); }
307 // Return the section flags given a section index.
309 section_flags(unsigned int shndx
)
310 { return this->do_section_flags(shndx
); }
312 // Return the section entsize given a section index.
314 section_entsize(unsigned int shndx
)
315 { return this->do_section_entsize(shndx
); }
317 // Return the section address given a section index.
319 section_address(unsigned int shndx
)
320 { return this->do_section_address(shndx
); }
322 // Return the section type given a section index.
324 section_type(unsigned int shndx
)
325 { return this->do_section_type(shndx
); }
327 // Return the section link field given a section index.
329 section_link(unsigned int shndx
)
330 { return this->do_section_link(shndx
); }
332 // Return the section info field given a section index.
334 section_info(unsigned int shndx
)
335 { return this->do_section_info(shndx
); }
337 // Return the required section alignment given a section index.
339 section_addralign(unsigned int shndx
)
340 { return this->do_section_addralign(shndx
); }
342 // Read the symbol information.
344 read_symbols(Read_symbols_data
* sd
)
345 { return this->do_read_symbols(sd
); }
347 // Pass sections which should be included in the link to the Layout
348 // object, and record where the sections go in the output file.
350 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
351 { this->do_layout(symtab
, layout
, sd
); }
353 // Add symbol information to the global symbol table.
355 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
356 { this->do_add_symbols(symtab
, sd
, layout
); }
358 // Functions and types for the elfcpp::Elf_file interface. This
359 // permit us to use Object as the File template parameter for
362 // The View class is returned by view. It must support a single
363 // method, data(). This is trivial, because get_view does what we
368 View(const unsigned char* p
)
377 const unsigned char* p_
;
382 view(off_t file_offset
, section_size_type data_size
)
383 { return View(this->get_view(file_offset
, data_size
, true, true)); }
387 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
389 // A location in the file.
395 Location(off_t fo
, section_size_type ds
)
396 : file_offset(fo
), data_size(ds
)
400 // Get a View given a Location.
401 View
view(Location loc
)
402 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
404 // Get a view into the underlying file.
406 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
408 return this->input_file()->file().get_view(this->offset_
, start
, size
,
412 // Get a lasting view into the underlying file.
414 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
417 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
418 size
, aligned
, cache
);
421 // Read data from the underlying file.
423 read(off_t start
, section_size_type size
, void* p
)
424 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
426 // Read multiple data from the underlying file.
428 read_multiple(const File_read::Read_multiple
& rm
)
429 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
431 // Stop caching views in the underlying file.
433 clear_view_cache_marks()
434 { this->input_file()->file().clear_view_cache_marks(); }
436 // Get the number of global symbols defined by this object, and the
437 // number of the symbols whose final definition came from this
440 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
442 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
444 // Return whether this object was found in a system directory.
446 is_in_system_directory() const
447 { return this->input_file()->is_in_system_directory(); }
449 // Return whether we found this object by searching a directory.
452 { return this->input_file()->will_search_for(); }
456 { return this->no_export_
; }
459 set_no_export(bool value
)
460 { this->no_export_
= value
; }
463 // Returns NULL for Objects that are not plugin objects. This method
464 // is overridden in the Pluginobj class.
469 // Read the symbols--implemented by child class.
471 do_read_symbols(Read_symbols_data
*) = 0;
473 // Lay out sections--implemented by child class.
475 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
477 // Add symbol information to the global symbol table--implemented by
480 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
482 // Return the location of the contents of a section. Implemented by
485 do_section_contents(unsigned int shndx
) = 0;
487 // Get the size of a section--implemented by child class.
489 do_section_size(unsigned int shndx
) = 0;
491 // Get the name of a section--implemented by child class.
493 do_section_name(unsigned int shndx
) = 0;
495 // Get section flags--implemented by child class.
497 do_section_flags(unsigned int shndx
) = 0;
499 // Get section entsize--implemented by child class.
501 do_section_entsize(unsigned int shndx
) = 0;
503 // Get section address--implemented by child class.
505 do_section_address(unsigned int shndx
) = 0;
507 // Get section type--implemented by child class.
509 do_section_type(unsigned int shndx
) = 0;
511 // Get section link field--implemented by child class.
513 do_section_link(unsigned int shndx
) = 0;
515 // Get section info field--implemented by child class.
517 do_section_info(unsigned int shndx
) = 0;
519 // Get section alignment--implemented by child class.
521 do_section_addralign(unsigned int shndx
) = 0;
523 // Return the Xindex structure to use.
525 do_initialize_xindex() = 0;
527 // Implement get_global_symbol_counts--implemented by child class.
529 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
531 // Set the number of sections.
534 { this->shnum_
= shnum
; }
536 // Functions used by both Sized_relobj and Sized_dynobj.
538 // Read the section data into a Read_symbols_data object.
539 template<int size
, bool big_endian
>
541 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
544 // Let the child class initialize the xindex object directly.
546 set_xindex(Xindex
* xindex
)
548 gold_assert(this->xindex_
== NULL
);
549 this->xindex_
= xindex
;
552 // If NAME is the name of a special .gnu.warning section, arrange
553 // for the warning to be issued. SHNDX is the section index.
554 // Return whether it is a warning section.
556 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
560 // This class may not be copied.
561 Object(const Object
&);
562 Object
& operator=(const Object
&);
564 // Name of object as printed to user.
566 // For reading the file.
567 Input_file
* input_file_
;
568 // Offset within the file--0 for an object file, non-0 for an
571 // Number of input sections.
573 // Whether this is a dynamic object.
575 // Many sections for objects with more than SHN_LORESERVE sections.
577 // True if exclude this object from automatic symbol export.
578 // This is used only for archive objects.
582 // A regular object (ET_REL). This is an abstract base class itself.
583 // The implementation is the template class Sized_relobj.
585 class Relobj
: public Object
588 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
589 : Object(name
, input_file
, false, offset
),
591 map_to_relocatable_relocs_(NULL
),
592 object_merge_map_(NULL
),
593 relocs_must_follow_section_writes_(false),
597 // During garbage collection, the Read_symbols_data pass for
598 // each object is stored as layout needs to be done after
602 { return this->sd_
; }
604 // Decides which section names have to be included in the worklist
607 is_section_name_included(const char *name
);
610 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
611 unsigned int section_header_size
);
614 set_symbols_data(Symbols_data
* sd
)
617 // During garbage collection, the Read_relocs pass for all objects
618 // is done before scanning the relocs. In that case, this->rd_ is
619 // used to store the information from Read_relocs for each object.
620 // This data is also used to compute the list of relevant sections.
623 { return this->rd_
; }
626 set_relocs_data(Read_relocs_data
* rd
)
630 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
634 read_relocs(Read_relocs_data
* rd
)
635 { return this->do_read_relocs(rd
); }
637 // Process the relocs, during garbage collection only.
639 gc_process_relocs(const General_options
& options
, Symbol_table
* symtab
,
640 Layout
* layout
, Read_relocs_data
* rd
)
641 { return this->do_gc_process_relocs(options
, symtab
, layout
, rd
); }
643 // Scan the relocs and adjust the symbol table.
645 scan_relocs(const General_options
& options
, Symbol_table
* symtab
,
646 Layout
* layout
, Read_relocs_data
* rd
)
647 { return this->do_scan_relocs(options
, symtab
, layout
, rd
); }
649 // The number of local symbols in the input symbol table.
651 local_symbol_count() const
652 { return this->do_local_symbol_count(); }
654 // Initial local symbol processing: count the number of local symbols
655 // in the output symbol table and dynamic symbol table; add local symbol
656 // names to *POOL and *DYNPOOL.
658 count_local_symbols(Stringpool_template
<char>* pool
,
659 Stringpool_template
<char>* dynpool
)
660 { return this->do_count_local_symbols(pool
, dynpool
); }
662 // Set the values of the local symbols, set the output symbol table
663 // indexes for the local variables, and set the offset where local
664 // symbol information will be stored. Returns the new local symbol index.
666 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
667 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
669 // Set the output dynamic symbol table indexes for the local variables.
671 set_local_dynsym_indexes(unsigned int index
)
672 { return this->do_set_local_dynsym_indexes(index
); }
674 // Set the offset where local dynamic symbol information will be stored.
676 set_local_dynsym_offset(off_t off
)
677 { return this->do_set_local_dynsym_offset(off
); }
679 // Relocate the input sections and write out the local symbols.
681 relocate(const General_options
& options
, const Symbol_table
* symtab
,
682 const Layout
* layout
, Output_file
* of
)
683 { return this->do_relocate(options
, symtab
, layout
, of
); }
685 // Return whether an input section is being included in the link.
687 is_section_included(unsigned int shndx
) const
689 gold_assert(shndx
< this->output_sections_
.size());
690 return this->output_sections_
[shndx
] != NULL
;
693 // Given a section index, return the corresponding Output_section.
694 // The return value will be NULL if the section is not included in
697 output_section(unsigned int shndx
) const
699 gold_assert(shndx
< this->output_sections_
.size());
700 return this->output_sections_
[shndx
];
703 // Given a section index, return the offset in the Output_section.
704 // The return value will be -1U if the section is specially mapped,
705 // such as a merge section.
707 output_section_offset(unsigned int shndx
) const
708 { return this->do_output_section_offset(shndx
); }
710 // Set the offset of an input section within its output section.
712 set_section_offset(unsigned int shndx
, uint64_t off
)
713 { this->do_set_section_offset(shndx
, off
); }
715 // Return true if we need to wait for output sections to be written
716 // before we can apply relocations. This is true if the object has
717 // any relocations for sections which require special handling, such
718 // as the exception frame section.
720 relocs_must_follow_section_writes() const
721 { return this->relocs_must_follow_section_writes_
; }
723 // Return the object merge map.
726 { return this->object_merge_map_
; }
728 // Set the object merge map.
730 set_merge_map(Object_merge_map
* object_merge_map
)
732 gold_assert(this->object_merge_map_
== NULL
);
733 this->object_merge_map_
= object_merge_map
;
736 // Record the relocatable reloc info for an input reloc section.
738 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
740 gold_assert(reloc_shndx
< this->shnum());
741 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
744 // Get the relocatable reloc info for an input reloc section.
746 relocatable_relocs(unsigned int reloc_shndx
)
748 gold_assert(reloc_shndx
< this->shnum());
749 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
752 // Layout sections whose layout was deferred while waiting for
753 // input files from a plugin.
755 layout_deferred_sections(Layout
* layout
)
756 { this->do_layout_deferred_sections(layout
); }
759 // The output section to be used for each input section, indexed by
760 // the input section number. The output section is NULL if the
761 // input section is to be discarded.
762 typedef std::vector
<Output_section
*> Output_sections
;
764 // Read the relocs--implemented by child class.
766 do_read_relocs(Read_relocs_data
*) = 0;
768 // Process the relocs--implemented by child class.
770 do_gc_process_relocs(const General_options
&, Symbol_table
*, Layout
*,
771 Read_relocs_data
*) = 0;
773 // Scan the relocs--implemented by child class.
775 do_scan_relocs(const General_options
&, Symbol_table
*, Layout
*,
776 Read_relocs_data
*) = 0;
778 // Return the number of local symbols--implemented by child class.
780 do_local_symbol_count() const = 0;
782 // Count local symbols--implemented by child class.
784 do_count_local_symbols(Stringpool_template
<char>*,
785 Stringpool_template
<char>*) = 0;
787 // Finalize the local symbols. Set the output symbol table indexes
788 // for the local variables, and set the offset where local symbol
789 // information will be stored.
791 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
793 // Set the output dynamic symbol table indexes for the local variables.
795 do_set_local_dynsym_indexes(unsigned int) = 0;
797 // Set the offset where local dynamic symbol information will be stored.
799 do_set_local_dynsym_offset(off_t
) = 0;
801 // Relocate the input sections and write out the local
802 // symbols--implemented by child class.
804 do_relocate(const General_options
& options
, const Symbol_table
* symtab
,
805 const Layout
*, Output_file
* of
) = 0;
807 // Get the offset of a section--implemented by child class.
809 do_output_section_offset(unsigned int shndx
) const = 0;
811 // Set the offset of a section--implemented by child class.
813 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
815 // Layout sections whose layout was deferred while waiting for
816 // input files from a plugin--implemented by child class.
818 do_layout_deferred_sections(Layout
*) = 0;
820 // Return the vector mapping input sections to output sections.
823 { return this->output_sections_
; }
825 const Output_sections
&
826 output_sections() const
827 { return this->output_sections_
; }
829 // Set the size of the relocatable relocs array.
831 size_relocatable_relocs()
833 this->map_to_relocatable_relocs_
=
834 new std::vector
<Relocatable_relocs
*>(this->shnum());
837 // Record that we must wait for the output sections to be written
838 // before applying relocations.
840 set_relocs_must_follow_section_writes()
841 { this->relocs_must_follow_section_writes_
= true; }
844 // Mapping from input sections to output section.
845 Output_sections output_sections_
;
846 // Mapping from input section index to the information recorded for
847 // the relocations. This is only used for a relocatable link.
848 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
849 // Mappings for merge sections. This is managed by the code in the
851 Object_merge_map
* object_merge_map_
;
852 // Whether we need to wait for output sections to be written before
853 // we can apply relocations.
854 bool relocs_must_follow_section_writes_
;
855 // Used to store the relocs data computed by the Read_relocs pass.
856 // Used during garbage collection of unused sections.
857 Read_relocs_data
* rd_
;
858 // Used to store the symbols data computed by the Read_symbols pass.
859 // Again used during garbage collection when laying out referenced
861 gold::Symbols_data
*sd_
;
864 // This class is used to handle relocations against a section symbol
865 // in an SHF_MERGE section. For such a symbol, we need to know the
866 // addend of the relocation before we can determine the final value.
867 // The addend gives us the location in the input section, and we can
868 // determine how it is mapped to the output section. For a
869 // non-section symbol, we apply the addend to the final value of the
870 // symbol; that is done in finalize_local_symbols, and does not use
874 class Merged_symbol_value
877 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
879 // We use a hash table to map offsets in the input section to output
881 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
883 Merged_symbol_value(Value input_value
, Value output_start_address
)
884 : input_value_(input_value
), output_start_address_(output_start_address
),
888 // Initialize the hash table.
890 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
892 // Release the hash table to save space.
894 free_input_to_output_map()
895 { this->output_addresses_
.clear(); }
897 // Get the output value corresponding to an addend. The object and
898 // input section index are passed in because the caller will have
899 // them; otherwise we could store them here.
901 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
903 // This is a relocation against a section symbol. ADDEND is the
904 // offset in the section. The result should be the start of some
905 // merge area. If the object file wants something else, it should
906 // use a regular symbol rather than a section symbol.
907 // Unfortunately, PR 6658 shows a case in which the object file
908 // refers to the section symbol, but uses a negative ADDEND to
909 // compensate for a PC relative reloc. We can't handle the
910 // general case. However, we can handle the special case of a
911 // negative addend, by assuming that it refers to the start of the
912 // section. Of course, that means that we have to guess when
913 // ADDEND is negative. It is normal to see a 32-bit value here
914 // even when the template parameter size is 64, as 64-bit object
915 // file formats have 32-bit relocations. We know this is a merge
916 // section, so we know it has to fit into memory. So we assume
917 // that we won't see a value larger than a large 32-bit unsigned
918 // value. This will break objects with very very large merge
919 // sections; they probably break in other ways anyhow.
920 Value input_offset
= this->input_value_
;
921 if (addend
< 0xffffff00)
923 input_offset
+= addend
;
926 typename
Output_addresses::const_iterator p
=
927 this->output_addresses_
.find(input_offset
);
928 if (p
!= this->output_addresses_
.end())
929 return p
->second
+ addend
;
931 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
936 // Get the output value for an input offset if we couldn't find it
937 // in the hash table.
939 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
940 Value input_offset
) const;
942 // The value of the section symbol in the input file. This is
943 // normally zero, but could in principle be something else.
945 // The start address of this merged section in the output file.
946 Value output_start_address_
;
947 // A hash table which maps offsets in the input section to output
948 // addresses. This only maps specific offsets, not all offsets.
949 Output_addresses output_addresses_
;
952 // This POD class is holds the value of a symbol. This is used for
953 // local symbols, and for all symbols during relocation processing.
954 // For special sections, such as SHF_MERGE sections, this calls a
955 // function to get the final symbol value.
961 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
964 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
965 is_ordinary_shndx_(false), is_section_symbol_(false),
966 is_tls_symbol_(false), has_output_value_(true)
967 { this->u_
.value
= 0; }
969 // Get the value of this symbol. OBJECT is the object in which this
970 // symbol is defined, and ADDEND is an addend to add to the value.
971 template<bool big_endian
>
973 value(const Sized_relobj
<size
, big_endian
>* object
, Value addend
) const
975 if (this->has_output_value_
)
976 return this->u_
.value
+ addend
;
979 gold_assert(this->is_ordinary_shndx_
);
980 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
985 // Set the value of this symbol in the output symbol table.
987 set_output_value(Value value
)
988 { this->u_
.value
= value
; }
990 // For a section symbol in a merged section, we need more
993 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
995 gold_assert(this->is_section_symbol_
);
996 this->has_output_value_
= false;
997 this->u_
.merged_symbol_value
= msv
;
1000 // Initialize the input to output map for a section symbol in a
1001 // merged section. We also initialize the value of a non-section
1002 // symbol in a merged section.
1004 initialize_input_to_output_map(const Relobj
* object
)
1006 if (!this->has_output_value_
)
1008 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1009 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1010 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1014 // Free the input to output map for a section symbol in a merged
1017 free_input_to_output_map()
1019 if (!this->has_output_value_
)
1020 this->u_
.merged_symbol_value
->free_input_to_output_map();
1023 // Set the value of the symbol from the input file. This is only
1024 // called by count_local_symbols, to communicate the value to
1025 // finalize_local_symbols.
1027 set_input_value(Value value
)
1028 { this->u_
.value
= value
; }
1030 // Return the input value. This is only called by
1031 // finalize_local_symbols and (in special cases) relocate_section.
1034 { return this->u_
.value
; }
1036 // Return whether this symbol should go into the output symbol
1039 needs_output_symtab_entry() const
1040 { return this->output_symtab_index_
!= -1U; }
1042 // Return the index in the output symbol table.
1044 output_symtab_index() const
1046 gold_assert(this->output_symtab_index_
!= 0);
1047 return this->output_symtab_index_
;
1050 // Set the index in the output symbol table.
1052 set_output_symtab_index(unsigned int i
)
1054 gold_assert(this->output_symtab_index_
== 0);
1055 this->output_symtab_index_
= i
;
1058 // Record that this symbol should not go into the output symbol
1061 set_no_output_symtab_entry()
1063 gold_assert(this->output_symtab_index_
== 0);
1064 this->output_symtab_index_
= -1U;
1067 // Set the index in the output dynamic symbol table.
1069 set_needs_output_dynsym_entry()
1071 gold_assert(!this->is_section_symbol());
1072 this->output_dynsym_index_
= 0;
1075 // Return whether this symbol should go into the output symbol
1078 needs_output_dynsym_entry() const
1080 return this->output_dynsym_index_
!= -1U;
1083 // Record that this symbol should go into the dynamic symbol table.
1085 set_output_dynsym_index(unsigned int i
)
1087 gold_assert(this->output_dynsym_index_
== 0);
1088 this->output_dynsym_index_
= i
;
1091 // Return the index in the output dynamic symbol table.
1093 output_dynsym_index() const
1095 gold_assert(this->output_dynsym_index_
!= 0
1096 && this->output_dynsym_index_
!= -1U);
1097 return this->output_dynsym_index_
;
1100 // Set the index of the input section in the input file.
1102 set_input_shndx(unsigned int i
, bool is_ordinary
)
1104 this->input_shndx_
= i
;
1105 // input_shndx_ field is a bitfield, so make sure that the value
1107 gold_assert(this->input_shndx_
== i
);
1108 this->is_ordinary_shndx_
= is_ordinary
;
1111 // Return the index of the input section in the input file.
1113 input_shndx(bool* is_ordinary
) const
1115 *is_ordinary
= this->is_ordinary_shndx_
;
1116 return this->input_shndx_
;
1119 // Whether this is a section symbol.
1121 is_section_symbol() const
1122 { return this->is_section_symbol_
; }
1124 // Record that this is a section symbol.
1126 set_is_section_symbol()
1128 gold_assert(!this->needs_output_dynsym_entry());
1129 this->is_section_symbol_
= true;
1132 // Record that this is a TLS symbol.
1135 { this->is_tls_symbol_
= true; }
1137 // Return TRUE if this is a TLS symbol.
1139 is_tls_symbol() const
1140 { return this->is_tls_symbol_
; }
1143 // The index of this local symbol in the output symbol table. This
1144 // will be -1 if the symbol should not go into the symbol table.
1145 unsigned int output_symtab_index_
;
1146 // The index of this local symbol in the dynamic symbol table. This
1147 // will be -1 if the symbol should not go into the symbol table.
1148 unsigned int output_dynsym_index_
;
1149 // The section index in the input file in which this symbol is
1151 unsigned int input_shndx_
: 28;
1152 // Whether the section index is an ordinary index, not a special
1154 bool is_ordinary_shndx_
: 1;
1155 // Whether this is a STT_SECTION symbol.
1156 bool is_section_symbol_
: 1;
1157 // Whether this is a STT_TLS symbol.
1158 bool is_tls_symbol_
: 1;
1159 // Whether this symbol has a value for the output file. This is
1160 // normally set to true during Layout::finalize, by
1161 // finalize_local_symbols. It will be false for a section symbol in
1162 // a merge section, as for such symbols we can not determine the
1163 // value to use in a relocation until we see the addend.
1164 bool has_output_value_
: 1;
1167 // This is used if has_output_value_ is true. Between
1168 // count_local_symbols and finalize_local_symbols, this is the
1169 // value in the input file. After finalize_local_symbols, it is
1170 // the value in the output file.
1172 // This is used if has_output_value_ is false. It points to the
1173 // information we need to get the value for a merge section.
1174 Merged_symbol_value
<size
>* merged_symbol_value
;
1178 // A GOT offset list. A symbol may have more than one GOT offset
1179 // (e.g., when mixing modules compiled with two different TLS models),
1180 // but will usually have at most one. GOT_TYPE identifies the type of
1181 // GOT entry; its values are specific to each target.
1183 class Got_offset_list
1187 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
1190 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
1191 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
1196 if (this->got_next_
!= NULL
)
1198 delete this->got_next_
;
1199 this->got_next_
= NULL
;
1203 // Initialize the fields to their default values.
1207 this->got_type_
= -1U;
1208 this->got_offset_
= 0;
1209 this->got_next_
= NULL
;
1212 // Set the offset for the GOT entry of type GOT_TYPE.
1214 set_offset(unsigned int got_type
, unsigned int got_offset
)
1216 if (this->got_type_
== -1U)
1218 this->got_type_
= got_type
;
1219 this->got_offset_
= got_offset
;
1223 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1225 if (g
->got_type_
== got_type
)
1227 g
->got_offset_
= got_offset
;
1231 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1232 g
->got_next_
= this->got_next_
;
1233 this->got_next_
= g
;
1237 // Return the offset for a GOT entry of type GOT_TYPE.
1239 get_offset(unsigned int got_type
) const
1241 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1243 if (g
->got_type_
== got_type
)
1244 return g
->got_offset_
;
1250 unsigned int got_type_
;
1251 unsigned int got_offset_
;
1252 Got_offset_list
* got_next_
;
1255 // A regular object file. This is size and endian specific.
1257 template<int size
, bool big_endian
>
1258 class Sized_relobj
: public Relobj
1261 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1262 typedef std::vector
<Symbol
*> Symbols
;
1263 typedef std::vector
<Symbol_value
<size
> > Local_values
;
1265 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1267 Sized_relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
,
1268 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
1272 // Checks if the offset of input section SHNDX within its output
1273 // section is invalid.
1275 is_output_section_offset_invalid(unsigned int shndx
) const
1276 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1278 // Set up the object file based on TARGET.
1282 // Return the number of symbols. This is only valid after
1283 // Object::add_symbols has been called.
1285 symbol_count() const
1286 { return this->local_symbol_count_
+ this->symbols_
.size(); }
1288 // If SYM is the index of a global symbol in the object file's
1289 // symbol table, return the Symbol object. Otherwise, return NULL.
1291 global_symbol(unsigned int sym
) const
1293 if (sym
>= this->local_symbol_count_
)
1295 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
1296 return this->symbols_
[sym
- this->local_symbol_count_
];
1301 // Return the section index of symbol SYM. Set *VALUE to its value
1302 // in the object file. Set *IS_ORDINARY if this is an ordinary
1303 // section index, not a special code between SHN_LORESERVE and
1304 // SHN_HIRESERVE. Note that for a symbol which is not defined in
1305 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
1306 // it will not return the final value of the symbol in the link.
1308 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
1310 // Return a pointer to the Symbol_value structure which holds the
1311 // value of a local symbol.
1312 const Symbol_value
<size
>*
1313 local_symbol(unsigned int sym
) const
1315 gold_assert(sym
< this->local_values_
.size());
1316 return &this->local_values_
[sym
];
1319 // Return the index of local symbol SYM in the ordinary symbol
1320 // table. A value of -1U means that the symbol is not being output.
1322 symtab_index(unsigned int sym
) const
1324 gold_assert(sym
< this->local_values_
.size());
1325 return this->local_values_
[sym
].output_symtab_index();
1328 // Return the index of local symbol SYM in the dynamic symbol
1329 // table. A value of -1U means that the symbol is not being output.
1331 dynsym_index(unsigned int sym
) const
1333 gold_assert(sym
< this->local_values_
.size());
1334 return this->local_values_
[sym
].output_dynsym_index();
1337 // Return the input section index of local symbol SYM.
1339 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
1341 gold_assert(sym
< this->local_values_
.size());
1342 return this->local_values_
[sym
].input_shndx(is_ordinary
);
1345 // Record that local symbol SYM needs a dynamic symbol entry.
1347 set_needs_output_dynsym_entry(unsigned int sym
)
1349 gold_assert(sym
< this->local_values_
.size());
1350 this->local_values_
[sym
].set_needs_output_dynsym_entry();
1353 // Return whether the local symbol SYMNDX has a GOT offset.
1354 // For TLS symbols, the GOT entry will hold its tp-relative offset.
1356 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1358 Local_got_offsets::const_iterator p
=
1359 this->local_got_offsets_
.find(symndx
);
1360 return (p
!= this->local_got_offsets_
.end()
1361 && p
->second
->get_offset(got_type
) != -1U);
1364 // Return the GOT offset of the local symbol SYMNDX.
1366 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1368 Local_got_offsets::const_iterator p
=
1369 this->local_got_offsets_
.find(symndx
);
1370 gold_assert(p
!= this->local_got_offsets_
.end());
1371 unsigned int off
= p
->second
->get_offset(got_type
);
1372 gold_assert(off
!= -1U);
1376 // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
1378 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1379 unsigned int got_offset
)
1381 Local_got_offsets::const_iterator p
=
1382 this->local_got_offsets_
.find(symndx
);
1383 if (p
!= this->local_got_offsets_
.end())
1384 p
->second
->set_offset(got_type
, got_offset
);
1387 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1388 std::pair
<Local_got_offsets::iterator
, bool> ins
=
1389 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
1390 gold_assert(ins
.second
);
1394 // Get the offset of input section SHNDX within its output section.
1395 // This is -1 if the input section requires a special mapping, such
1396 // as a merge section. The output section can be found in the
1397 // output_sections_ field of the parent class Relobj.
1399 get_output_section_offset(unsigned int shndx
) const
1401 gold_assert(shndx
< this->section_offsets_
.size());
1402 return this->section_offsets_
[shndx
];
1405 // Return the name of the symbol that spans the given offset in the
1406 // specified section in this object. This is used only for error
1407 // messages and is not particularly efficient.
1409 get_symbol_location_info(unsigned int shndx
, off_t offset
,
1410 Symbol_location_info
* info
);
1412 // Look for a kept section corresponding to the given discarded section,
1413 // and return its output address. This is used only for relocations in
1414 // debugging sections.
1416 map_to_kept_section(unsigned int shndx
, bool* found
) const;
1419 // Read the symbols.
1421 do_read_symbols(Read_symbols_data
*);
1423 // Return the number of local symbols.
1425 do_local_symbol_count() const
1426 { return this->local_symbol_count_
; }
1428 // Lay out the input sections.
1430 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
1432 // Layout sections whose layout was deferred while waiting for
1433 // input files from a plugin.
1435 do_layout_deferred_sections(Layout
*);
1437 // Add the symbols to the symbol table.
1439 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
1443 do_read_relocs(Read_relocs_data
*);
1445 // Process the relocs to find list of referenced sections. Used only
1446 // during garbage collection.
1448 do_gc_process_relocs(const General_options
&, Symbol_table
*, Layout
*,
1451 // Scan the relocs and adjust the symbol table.
1453 do_scan_relocs(const General_options
&, Symbol_table
*, Layout
*,
1456 // Count the local symbols.
1458 do_count_local_symbols(Stringpool_template
<char>*,
1459 Stringpool_template
<char>*);
1461 // Finalize the local symbols.
1463 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
1465 // Set the offset where local dynamic symbol information will be stored.
1467 do_set_local_dynsym_indexes(unsigned int);
1469 // Set the offset where local dynamic symbol information will be stored.
1471 do_set_local_dynsym_offset(off_t
);
1473 // Relocate the input sections and write out the local symbols.
1475 do_relocate(const General_options
& options
, const Symbol_table
* symtab
,
1476 const Layout
*, Output_file
* of
);
1478 // Get the size of a section.
1480 do_section_size(unsigned int shndx
)
1481 { return this->elf_file_
.section_size(shndx
); }
1483 // Get the name of a section.
1485 do_section_name(unsigned int shndx
)
1486 { return this->elf_file_
.section_name(shndx
); }
1488 // Return the location of the contents of a section.
1490 do_section_contents(unsigned int shndx
)
1491 { return this->elf_file_
.section_contents(shndx
); }
1493 // Return section flags.
1495 do_section_flags(unsigned int shndx
);
1497 // Return section entsize.
1499 do_section_entsize(unsigned int shndx
);
1501 // Return section address.
1503 do_section_address(unsigned int shndx
)
1504 { return this->elf_file_
.section_addr(shndx
); }
1506 // Return section type.
1508 do_section_type(unsigned int shndx
)
1509 { return this->elf_file_
.section_type(shndx
); }
1511 // Return the section link field.
1513 do_section_link(unsigned int shndx
)
1514 { return this->elf_file_
.section_link(shndx
); }
1516 // Return the section info field.
1518 do_section_info(unsigned int shndx
)
1519 { return this->elf_file_
.section_info(shndx
); }
1521 // Return the section alignment.
1523 do_section_addralign(unsigned int shndx
)
1524 { return this->elf_file_
.section_addralign(shndx
); }
1526 // Return the Xindex structure to use.
1528 do_initialize_xindex();
1530 // Get symbol counts.
1532 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
1534 // Get the offset of a section.
1536 do_output_section_offset(unsigned int shndx
) const
1538 Address off
= this->get_output_section_offset(shndx
);
1539 if (off
== invalid_address
)
1544 // Set the offset of a section.
1546 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1548 gold_assert(shndx
< this->section_offsets_
.size());
1549 this->section_offsets_
[shndx
] = convert_types
<Address
, uint64_t>(off
);
1554 typedef Sized_relobj
<size
, big_endian
> This
;
1555 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
1556 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1557 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1558 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
1560 // To keep track of discarded comdat sections, we need to map a member
1561 // section index to the object and section index of the corresponding
1563 struct Kept_comdat_section
1565 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
1566 : object(a_object
), shndx(a_shndx
)
1571 typedef std::map
<unsigned int, Kept_comdat_section
>
1572 Kept_comdat_section_table
;
1574 // Adjust a section index if necessary.
1576 adjust_shndx(unsigned int shndx
)
1578 if (shndx
>= elfcpp::SHN_LORESERVE
)
1579 shndx
+= this->elf_file_
.large_shndx_offset();
1583 // Find the SHT_SYMTAB section, given the section headers.
1585 find_symtab(const unsigned char* pshdrs
);
1587 // Return whether SHDR has the right flags for a GNU style exception
1590 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
1592 // Return whether there is a section named .eh_frame which might be
1593 // a GNU style exception frame section.
1595 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
1596 section_size_type names_size
) const;
1598 // Whether to include a section group in the link.
1600 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
1601 const unsigned char*, const char *, section_size_type
,
1602 std::vector
<bool>*);
1604 // Whether to include a linkonce section in the link.
1606 include_linkonce_section(Layout
*, unsigned int, const char*,
1607 const elfcpp::Shdr
<size
, big_endian
>&);
1609 // Layout an input section.
1611 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
1612 typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
1613 unsigned int reloc_type
);
1615 // Views and sizes when relocating.
1618 unsigned char* view
;
1619 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
1621 section_size_type view_size
;
1622 bool is_input_output_view
;
1623 bool is_postprocessing_view
;
1626 typedef std::vector
<View_size
> Views
;
1628 // Write section data to the output file. Record the views and
1629 // sizes in VIEWS for use when relocating.
1631 write_sections(const unsigned char* pshdrs
, Output_file
*, Views
*);
1633 // Relocate the sections in the output file.
1635 relocate_sections(const General_options
& options
, const Symbol_table
*,
1636 const Layout
*, const unsigned char* pshdrs
, Views
*);
1638 // Scan the input relocations for --emit-relocs.
1640 emit_relocs_scan(const General_options
&, Symbol_table
*, Layout
*,
1641 const unsigned char* plocal_syms
,
1642 const Read_relocs_data::Relocs_list::iterator
&);
1644 // Scan the input relocations for --emit-relocs, templatized on the
1645 // type of the relocation section.
1646 template<int sh_type
>
1648 emit_relocs_scan_reltype(const General_options
&, Symbol_table
*, Layout
*,
1649 const unsigned char* plocal_syms
,
1650 const Read_relocs_data::Relocs_list::iterator
&,
1651 Relocatable_relocs
*);
1653 // Emit the relocs for --emit-relocs.
1655 emit_relocs(const Relocate_info
<size
, big_endian
>*, unsigned int,
1656 unsigned int sh_type
, const unsigned char* prelocs
,
1657 size_t reloc_count
, Output_section
*, Address output_offset
,
1658 unsigned char* view
, Address address
,
1659 section_size_type view_size
,
1660 unsigned char* reloc_view
, section_size_type reloc_view_size
);
1662 // Emit the relocs for --emit-relocs, templatized on the type of the
1663 // relocation section.
1664 template<int sh_type
>
1666 emit_relocs_reltype(const Relocate_info
<size
, big_endian
>*, unsigned int,
1667 const unsigned char* prelocs
, size_t reloc_count
,
1668 Output_section
*, Address output_offset
,
1669 unsigned char* view
, Address address
,
1670 section_size_type view_size
,
1671 unsigned char* reloc_view
,
1672 section_size_type reloc_view_size
);
1674 // Initialize input to output maps for section symbols in merged
1677 initialize_input_to_output_maps();
1679 // Free the input to output maps for section symbols in merged
1682 free_input_to_output_maps();
1684 // Write out the local symbols.
1686 write_local_symbols(Output_file
*,
1687 const Stringpool_template
<char>*,
1688 const Stringpool_template
<char>*,
1689 Output_symtab_xindex
*,
1690 Output_symtab_xindex
*);
1692 // Clear the local symbol information.
1694 clear_local_symbols()
1696 this->local_values_
.clear();
1697 this->local_got_offsets_
.clear();
1700 // Record a mapping from discarded section SHNDX to the corresponding
1703 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
1704 unsigned int kept_shndx
)
1706 Kept_comdat_section
kept(kept_object
, kept_shndx
);
1707 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
1710 // Find the kept section corresponding to the discarded section
1711 // SHNDX. Return true if found.
1713 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
1714 unsigned int* kept_shndx
) const
1716 typename
Kept_comdat_section_table::const_iterator p
=
1717 this->kept_comdat_sections_
.find(shndx
);
1718 if (p
== this->kept_comdat_sections_
.end())
1720 *kept_object
= p
->second
.object
;
1721 *kept_shndx
= p
->second
.shndx
;
1725 // The GOT offsets of local symbols. This map also stores GOT offsets
1726 // for tp-relative offsets for TLS symbols.
1727 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
1729 // The TLS GOT offsets of local symbols. The map stores the offsets
1730 // for either a single GOT entry that holds the module index of a TLS
1731 // symbol, or a pair of GOT entries containing the module index and
1732 // dtv-relative offset.
1733 struct Tls_got_entry
1735 Tls_got_entry(int got_offset
, bool have_pair
)
1736 : got_offset_(got_offset
),
1737 have_pair_(have_pair
)
1742 typedef Unordered_map
<unsigned int, Tls_got_entry
> Local_tls_got_offsets
;
1744 // Saved information for sections whose layout was deferred.
1745 struct Deferred_layout
1747 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1748 Deferred_layout(unsigned int shndx
, const char* name
,
1749 const unsigned char* pshdr
,
1750 unsigned int reloc_shndx
, unsigned int reloc_type
)
1751 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
1752 reloc_type_(reloc_type
)
1754 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
1756 unsigned int shndx_
;
1758 unsigned int reloc_shndx_
;
1759 unsigned int reloc_type_
;
1760 unsigned char shdr_data_
[shdr_size
];
1763 // General access to the ELF file.
1764 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
1765 // Index of SHT_SYMTAB section.
1766 unsigned int symtab_shndx_
;
1767 // The number of local symbols.
1768 unsigned int local_symbol_count_
;
1769 // The number of local symbols which go into the output file.
1770 unsigned int output_local_symbol_count_
;
1771 // The number of local symbols which go into the output file's dynamic
1773 unsigned int output_local_dynsym_count_
;
1774 // The entries in the symbol table for the external symbols.
1776 // Number of symbols defined in object file itself.
1777 size_t defined_count_
;
1778 // File offset for local symbols.
1779 off_t local_symbol_offset_
;
1780 // File offset for local dynamic symbols.
1781 off_t local_dynsym_offset_
;
1782 // Values of local symbols.
1783 Local_values local_values_
;
1784 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1785 // for TLS symbols, indexed by symbol number.
1786 Local_got_offsets local_got_offsets_
;
1787 // For each input section, the offset of the input section in its
1788 // output section. This is INVALID_ADDRESS if the input section requires a
1790 std::vector
<Address
> section_offsets_
;
1791 // Table mapping discarded comdat sections to corresponding kept sections.
1792 Kept_comdat_section_table kept_comdat_sections_
;
1793 // Whether this object has a GNU style .eh_frame section.
1795 // If this object has a GNU style .eh_frame section that is discarded in
1796 // output, record the index here. Otherwise it is -1U.
1797 unsigned int discarded_eh_frame_shndx_
;
1798 // The list of sections whose layout was deferred.
1799 std::vector
<Deferred_layout
> deferred_layout_
;
1802 // A class to manage the list of all objects.
1808 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
1811 // The type of the list of input relocateable objects.
1812 typedef std::vector
<Relobj
*> Relobj_list
;
1813 typedef Relobj_list::const_iterator Relobj_iterator
;
1815 // The type of the list of input dynamic objects.
1816 typedef std::vector
<Dynobj
*> Dynobj_list
;
1817 typedef Dynobj_list::const_iterator Dynobj_iterator
;
1819 // Add an object to the list. Return true if all is well, or false
1820 // if this object should be ignored.
1822 add_object(Object
*);
1824 // Start processing an archive.
1826 archive_start(Archive
*);
1828 // Stop processing an archive.
1830 archive_stop(Archive
*);
1832 // For each dynamic object, check whether we've seen all of its
1833 // explicit dependencies.
1835 check_dynamic_dependencies() const;
1837 // Return whether an object was found in the system library
1840 found_in_system_library_directory(const Object
*) const;
1842 // Print symbol counts.
1844 print_symbol_counts(const Symbol_table
*) const;
1846 // Iterate over all regular objects.
1849 relobj_begin() const
1850 { return this->relobj_list_
.begin(); }
1854 { return this->relobj_list_
.end(); }
1856 // Iterate over all dynamic objects.
1859 dynobj_begin() const
1860 { return this->dynobj_list_
.begin(); }
1864 { return this->dynobj_list_
.end(); }
1866 // Return whether we have seen any dynamic objects.
1869 { return !this->dynobj_list_
.empty(); }
1871 // Return the number of input objects.
1873 number_of_input_objects() const
1874 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
1877 Input_objects(const Input_objects
&);
1878 Input_objects
& operator=(const Input_objects
&);
1880 // The list of ordinary objects included in the link.
1881 Relobj_list relobj_list_
;
1882 // The list of dynamic objects included in the link.
1883 Dynobj_list dynobj_list_
;
1884 // SONAMEs that we have seen.
1885 Unordered_set
<std::string
> sonames_
;
1886 // Manage cross-references if requested.
1890 // Some of the information we pass to the relocation routines. We
1891 // group this together to avoid passing a dozen different arguments.
1893 template<int size
, bool big_endian
>
1894 struct Relocate_info
1896 // Command line options.
1897 const General_options
* options
;
1899 const Symbol_table
* symtab
;
1901 const Layout
* layout
;
1902 // Object being relocated.
1903 Sized_relobj
<size
, big_endian
>* object
;
1904 // Section index of relocation section.
1905 unsigned int reloc_shndx
;
1906 // Section index of section being relocated.
1907 unsigned int data_shndx
;
1909 // Return a string showing the location of a relocation. This is
1910 // only used for error messages.
1912 location(size_t relnum
, off_t reloffset
) const;
1915 // Return whether INPUT_FILE contains an ELF object start at file
1916 // offset OFFSET. This sets *START to point to a view of the start of
1917 // the file. It sets *READ_SIZE to the number of bytes in the view.
1920 is_elf_object(Input_file
* input_file
, off_t offset
,
1921 const unsigned char** start
, int *read_size
);
1923 // Return an Object appropriate for the input file. P is BYTES long,
1924 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
1925 // this sees an object the linker is not configured to support, it
1926 // sets *PUNCONFIGURED to true and returns NULL without giving an
1930 make_elf_object(const std::string
& name
, Input_file
*,
1931 off_t offset
, const unsigned char* p
,
1932 section_offset_type bytes
, bool* punconfigured
);
1934 } // end namespace gold
1936 #endif // !defined(GOLD_OBJECT_H)