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
), uses_split_stack_(false),
199 has_no_split_stack_(false), xindex_(NULL
), no_export_(false)
200 { input_file
->file().add_object(); }
203 { this->input_file_
->file().remove_object(); }
205 // Return the name of the object as we would report it to the tuser.
208 { return this->name_
; }
210 // Get the offset into the file.
213 { return this->offset_
; }
215 // Return whether this is a dynamic object.
218 { return this->is_dynamic_
; }
220 // Return whether this object was compiled with -fsplit-stack.
222 uses_split_stack() const
223 { return this->uses_split_stack_
; }
225 // Return whether this object contains any functions compiled with
226 // the no_split_stack attribute.
228 has_no_split_stack() const
229 { return this->has_no_split_stack_
; }
231 // Returns NULL for Objects that are not plugin objects. This method
232 // is overridden in the Pluginobj class.
235 { return this->do_pluginobj(); }
237 // Get the file. We pass on const-ness.
240 { return this->input_file_
; }
244 { return this->input_file_
; }
246 // Lock the underlying file.
249 { this->input_file()->file().lock(t
); }
251 // Unlock the underlying file.
253 unlock(const Task
* t
)
254 { this->input_file()->file().unlock(t
); }
256 // Return whether the underlying file is locked.
259 { return this->input_file()->file().is_locked(); }
261 // Return the token, so that the task can be queued.
264 { return this->input_file()->file().token(); }
266 // Release the underlying file.
269 { this->input_file_
->file().release(); }
271 // Return whether we should just read symbols from this file.
274 { return this->input_file()->just_symbols(); }
276 // Get the number of sections.
279 { return this->shnum_
; }
281 // Return a view of the contents of a section. Set *PLEN to the
282 // size. CACHE is a hint as in File_read::get_view.
284 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
286 // Adjust a symbol's section index as needed. SYMNDX is the index
287 // of the symbol and SHNDX is the symbol's section from
288 // get_st_shndx. This returns the section index. It sets
289 // *IS_ORDINARY to indicate whether this is a normal section index,
290 // rather than a special code between SHN_LORESERVE and
293 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
295 if (shndx
< elfcpp::SHN_LORESERVE
)
297 else if (shndx
== elfcpp::SHN_XINDEX
)
299 if (this->xindex_
== NULL
)
300 this->xindex_
= this->do_initialize_xindex();
301 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
305 *is_ordinary
= false;
309 // Return the size of a section given a section index.
311 section_size(unsigned int shndx
)
312 { return this->do_section_size(shndx
); }
314 // Return the name of a section given a section index.
316 section_name(unsigned int shndx
)
317 { return this->do_section_name(shndx
); }
319 // Return the section flags given a section index.
321 section_flags(unsigned int shndx
)
322 { return this->do_section_flags(shndx
); }
324 // Return the section entsize given a section index.
326 section_entsize(unsigned int shndx
)
327 { return this->do_section_entsize(shndx
); }
329 // Return the section address given a section index.
331 section_address(unsigned int shndx
)
332 { return this->do_section_address(shndx
); }
334 // Return the section type given a section index.
336 section_type(unsigned int shndx
)
337 { return this->do_section_type(shndx
); }
339 // Return the section link field given a section index.
341 section_link(unsigned int shndx
)
342 { return this->do_section_link(shndx
); }
344 // Return the section info field given a section index.
346 section_info(unsigned int shndx
)
347 { return this->do_section_info(shndx
); }
349 // Return the required section alignment given a section index.
351 section_addralign(unsigned int shndx
)
352 { return this->do_section_addralign(shndx
); }
354 // Read the symbol information.
356 read_symbols(Read_symbols_data
* sd
)
357 { return this->do_read_symbols(sd
); }
359 // Pass sections which should be included in the link to the Layout
360 // object, and record where the sections go in the output file.
362 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
363 { this->do_layout(symtab
, layout
, sd
); }
365 // Add symbol information to the global symbol table.
367 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
368 { this->do_add_symbols(symtab
, sd
, layout
); }
370 // Functions and types for the elfcpp::Elf_file interface. This
371 // permit us to use Object as the File template parameter for
374 // The View class is returned by view. It must support a single
375 // method, data(). This is trivial, because get_view does what we
380 View(const unsigned char* p
)
389 const unsigned char* p_
;
394 view(off_t file_offset
, section_size_type data_size
)
395 { return View(this->get_view(file_offset
, data_size
, true, true)); }
399 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
401 // A location in the file.
407 Location(off_t fo
, section_size_type ds
)
408 : file_offset(fo
), data_size(ds
)
412 // Get a View given a Location.
413 View
view(Location loc
)
414 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
416 // Get a view into the underlying file.
418 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
420 return this->input_file()->file().get_view(this->offset_
, start
, size
,
424 // Get a lasting view into the underlying file.
426 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
429 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
430 size
, aligned
, cache
);
433 // Read data from the underlying file.
435 read(off_t start
, section_size_type size
, void* p
)
436 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
438 // Read multiple data from the underlying file.
440 read_multiple(const File_read::Read_multiple
& rm
)
441 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
443 // Stop caching views in the underlying file.
445 clear_view_cache_marks()
446 { this->input_file()->file().clear_view_cache_marks(); }
448 // Get the number of global symbols defined by this object, and the
449 // number of the symbols whose final definition came from this
452 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
454 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
456 // Return whether this object was found in a system directory.
458 is_in_system_directory() const
459 { return this->input_file()->is_in_system_directory(); }
461 // Return whether we found this object by searching a directory.
464 { return this->input_file()->will_search_for(); }
468 { return this->no_export_
; }
471 set_no_export(bool value
)
472 { this->no_export_
= value
; }
475 // Returns NULL for Objects that are not plugin objects. This method
476 // is overridden in the Pluginobj class.
481 // Read the symbols--implemented by child class.
483 do_read_symbols(Read_symbols_data
*) = 0;
485 // Lay out sections--implemented by child class.
487 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
489 // Add symbol information to the global symbol table--implemented by
492 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
494 // Return the location of the contents of a section. Implemented by
497 do_section_contents(unsigned int shndx
) = 0;
499 // Get the size of a section--implemented by child class.
501 do_section_size(unsigned int shndx
) = 0;
503 // Get the name of a section--implemented by child class.
505 do_section_name(unsigned int shndx
) = 0;
507 // Get section flags--implemented by child class.
509 do_section_flags(unsigned int shndx
) = 0;
511 // Get section entsize--implemented by child class.
513 do_section_entsize(unsigned int shndx
) = 0;
515 // Get section address--implemented by child class.
517 do_section_address(unsigned int shndx
) = 0;
519 // Get section type--implemented by child class.
521 do_section_type(unsigned int shndx
) = 0;
523 // Get section link field--implemented by child class.
525 do_section_link(unsigned int shndx
) = 0;
527 // Get section info field--implemented by child class.
529 do_section_info(unsigned int shndx
) = 0;
531 // Get section alignment--implemented by child class.
533 do_section_addralign(unsigned int shndx
) = 0;
535 // Return the Xindex structure to use.
537 do_initialize_xindex() = 0;
539 // Implement get_global_symbol_counts--implemented by child class.
541 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
543 // Set the number of sections.
546 { this->shnum_
= shnum
; }
548 // Functions used by both Sized_relobj and Sized_dynobj.
550 // Read the section data into a Read_symbols_data object.
551 template<int size
, bool big_endian
>
553 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
556 // Let the child class initialize the xindex object directly.
558 set_xindex(Xindex
* xindex
)
560 gold_assert(this->xindex_
== NULL
);
561 this->xindex_
= xindex
;
564 // If NAME is the name of a special .gnu.warning section, arrange
565 // for the warning to be issued. SHNDX is the section index.
566 // Return whether it is a warning section.
568 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
571 // If NAME is the name of the special section which indicates that
572 // this object was compiled with -fstack-split, mark it accordingly,
573 // and return true. Otherwise return false.
575 handle_split_stack_section(const char* name
);
578 // This class may not be copied.
579 Object(const Object
&);
580 Object
& operator=(const Object
&);
582 // Name of object as printed to user.
584 // For reading the file.
585 Input_file
* input_file_
;
586 // Offset within the file--0 for an object file, non-0 for an
589 // Number of input sections.
591 // Whether this is a dynamic object.
593 // Whether this object was compiled with -fsplit-stack.
594 bool uses_split_stack_
;
595 // Whether this object contains any functions compiled with the
596 // no_split_stack attribute.
597 bool has_no_split_stack_
;
598 // Many sections for objects with more than SHN_LORESERVE sections.
600 // True if exclude this object from automatic symbol export.
601 // This is used only for archive objects.
605 // A regular object (ET_REL). This is an abstract base class itself.
606 // The implementation is the template class Sized_relobj.
608 class Relobj
: public Object
611 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
612 : Object(name
, input_file
, false, offset
),
614 map_to_relocatable_relocs_(NULL
),
615 object_merge_map_(NULL
),
616 relocs_must_follow_section_writes_(false),
620 // During garbage collection, the Read_symbols_data pass for
621 // each object is stored as layout needs to be done after
625 { return this->sd_
; }
627 // Decides which section names have to be included in the worklist
630 is_section_name_included(const char *name
);
633 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
634 unsigned int section_header_size
);
637 set_symbols_data(Symbols_data
* sd
)
640 // During garbage collection, the Read_relocs pass for all objects
641 // is done before scanning the relocs. In that case, this->rd_ is
642 // used to store the information from Read_relocs for each object.
643 // This data is also used to compute the list of relevant sections.
646 { return this->rd_
; }
649 set_relocs_data(Read_relocs_data
* rd
)
653 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
657 read_relocs(Read_relocs_data
* rd
)
658 { return this->do_read_relocs(rd
); }
660 // Process the relocs, during garbage collection only.
662 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
663 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
665 // Scan the relocs and adjust the symbol table.
667 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
668 { return this->do_scan_relocs(symtab
, layout
, rd
); }
670 // The number of local symbols in the input symbol table.
672 local_symbol_count() const
673 { return this->do_local_symbol_count(); }
675 // Initial local symbol processing: count the number of local symbols
676 // in the output symbol table and dynamic symbol table; add local symbol
677 // names to *POOL and *DYNPOOL.
679 count_local_symbols(Stringpool_template
<char>* pool
,
680 Stringpool_template
<char>* dynpool
)
681 { return this->do_count_local_symbols(pool
, dynpool
); }
683 // Set the values of the local symbols, set the output symbol table
684 // indexes for the local variables, and set the offset where local
685 // symbol information will be stored. Returns the new local symbol index.
687 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
688 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
690 // Set the output dynamic symbol table indexes for the local variables.
692 set_local_dynsym_indexes(unsigned int index
)
693 { return this->do_set_local_dynsym_indexes(index
); }
695 // Set the offset where local dynamic symbol information will be stored.
697 set_local_dynsym_offset(off_t off
)
698 { return this->do_set_local_dynsym_offset(off
); }
700 // Relocate the input sections and write out the local symbols.
702 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
703 { return this->do_relocate(symtab
, layout
, of
); }
705 // Return whether an input section is being included in the link.
707 is_section_included(unsigned int shndx
) const
709 gold_assert(shndx
< this->output_sections_
.size());
710 return this->output_sections_
[shndx
] != NULL
;
713 // Given a section index, return the corresponding Output_section.
714 // The return value will be NULL if the section is not included in
717 output_section(unsigned int shndx
) const
719 gold_assert(shndx
< this->output_sections_
.size());
720 return this->output_sections_
[shndx
];
723 // Given a section index, return the offset in the Output_section.
724 // The return value will be -1U if the section is specially mapped,
725 // such as a merge section.
727 output_section_offset(unsigned int shndx
) const
728 { return this->do_output_section_offset(shndx
); }
730 // Set the offset of an input section within its output section.
732 set_section_offset(unsigned int shndx
, uint64_t off
)
733 { this->do_set_section_offset(shndx
, off
); }
735 // Return true if we need to wait for output sections to be written
736 // before we can apply relocations. This is true if the object has
737 // any relocations for sections which require special handling, such
738 // as the exception frame section.
740 relocs_must_follow_section_writes() const
741 { return this->relocs_must_follow_section_writes_
; }
743 // Return the object merge map.
746 { return this->object_merge_map_
; }
748 // Set the object merge map.
750 set_merge_map(Object_merge_map
* object_merge_map
)
752 gold_assert(this->object_merge_map_
== NULL
);
753 this->object_merge_map_
= object_merge_map
;
756 // Record the relocatable reloc info for an input reloc section.
758 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
760 gold_assert(reloc_shndx
< this->shnum());
761 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
764 // Get the relocatable reloc info for an input reloc section.
766 relocatable_relocs(unsigned int reloc_shndx
)
768 gold_assert(reloc_shndx
< this->shnum());
769 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
772 // Layout sections whose layout was deferred while waiting for
773 // input files from a plugin.
775 layout_deferred_sections(Layout
* layout
)
776 { this->do_layout_deferred_sections(layout
); }
779 // The output section to be used for each input section, indexed by
780 // the input section number. The output section is NULL if the
781 // input section is to be discarded.
782 typedef std::vector
<Output_section
*> Output_sections
;
784 // Read the relocs--implemented by child class.
786 do_read_relocs(Read_relocs_data
*) = 0;
788 // Process the relocs--implemented by child class.
790 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
792 // Scan the relocs--implemented by child class.
794 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
796 // Return the number of local symbols--implemented by child class.
798 do_local_symbol_count() const = 0;
800 // Count local symbols--implemented by child class.
802 do_count_local_symbols(Stringpool_template
<char>*,
803 Stringpool_template
<char>*) = 0;
805 // Finalize the local symbols. Set the output symbol table indexes
806 // for the local variables, and set the offset where local symbol
807 // information will be stored.
809 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
811 // Set the output dynamic symbol table indexes for the local variables.
813 do_set_local_dynsym_indexes(unsigned int) = 0;
815 // Set the offset where local dynamic symbol information will be stored.
817 do_set_local_dynsym_offset(off_t
) = 0;
819 // Relocate the input sections and write out the local
820 // symbols--implemented by child class.
822 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
824 // Get the offset of a section--implemented by child class.
826 do_output_section_offset(unsigned int shndx
) const = 0;
828 // Set the offset of a section--implemented by child class.
830 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
832 // Layout sections whose layout was deferred while waiting for
833 // input files from a plugin--implemented by child class.
835 do_layout_deferred_sections(Layout
*) = 0;
837 // Return the vector mapping input sections to output sections.
840 { return this->output_sections_
; }
842 const Output_sections
&
843 output_sections() const
844 { return this->output_sections_
; }
846 // Set the size of the relocatable relocs array.
848 size_relocatable_relocs()
850 this->map_to_relocatable_relocs_
=
851 new std::vector
<Relocatable_relocs
*>(this->shnum());
854 // Record that we must wait for the output sections to be written
855 // before applying relocations.
857 set_relocs_must_follow_section_writes()
858 { this->relocs_must_follow_section_writes_
= true; }
861 // Mapping from input sections to output section.
862 Output_sections output_sections_
;
863 // Mapping from input section index to the information recorded for
864 // the relocations. This is only used for a relocatable link.
865 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
866 // Mappings for merge sections. This is managed by the code in the
868 Object_merge_map
* object_merge_map_
;
869 // Whether we need to wait for output sections to be written before
870 // we can apply relocations.
871 bool relocs_must_follow_section_writes_
;
872 // Used to store the relocs data computed by the Read_relocs pass.
873 // Used during garbage collection of unused sections.
874 Read_relocs_data
* rd_
;
875 // Used to store the symbols data computed by the Read_symbols pass.
876 // Again used during garbage collection when laying out referenced
878 gold::Symbols_data
*sd_
;
881 // This class is used to handle relocations against a section symbol
882 // in an SHF_MERGE section. For such a symbol, we need to know the
883 // addend of the relocation before we can determine the final value.
884 // The addend gives us the location in the input section, and we can
885 // determine how it is mapped to the output section. For a
886 // non-section symbol, we apply the addend to the final value of the
887 // symbol; that is done in finalize_local_symbols, and does not use
891 class Merged_symbol_value
894 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
896 // We use a hash table to map offsets in the input section to output
898 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
900 Merged_symbol_value(Value input_value
, Value output_start_address
)
901 : input_value_(input_value
), output_start_address_(output_start_address
),
905 // Initialize the hash table.
907 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
909 // Release the hash table to save space.
911 free_input_to_output_map()
912 { this->output_addresses_
.clear(); }
914 // Get the output value corresponding to an addend. The object and
915 // input section index are passed in because the caller will have
916 // them; otherwise we could store them here.
918 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
920 // This is a relocation against a section symbol. ADDEND is the
921 // offset in the section. The result should be the start of some
922 // merge area. If the object file wants something else, it should
923 // use a regular symbol rather than a section symbol.
924 // Unfortunately, PR 6658 shows a case in which the object file
925 // refers to the section symbol, but uses a negative ADDEND to
926 // compensate for a PC relative reloc. We can't handle the
927 // general case. However, we can handle the special case of a
928 // negative addend, by assuming that it refers to the start of the
929 // section. Of course, that means that we have to guess when
930 // ADDEND is negative. It is normal to see a 32-bit value here
931 // even when the template parameter size is 64, as 64-bit object
932 // file formats have 32-bit relocations. We know this is a merge
933 // section, so we know it has to fit into memory. So we assume
934 // that we won't see a value larger than a large 32-bit unsigned
935 // value. This will break objects with very very large merge
936 // sections; they probably break in other ways anyhow.
937 Value input_offset
= this->input_value_
;
938 if (addend
< 0xffffff00)
940 input_offset
+= addend
;
943 typename
Output_addresses::const_iterator p
=
944 this->output_addresses_
.find(input_offset
);
945 if (p
!= this->output_addresses_
.end())
946 return p
->second
+ addend
;
948 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
953 // Get the output value for an input offset if we couldn't find it
954 // in the hash table.
956 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
957 Value input_offset
) const;
959 // The value of the section symbol in the input file. This is
960 // normally zero, but could in principle be something else.
962 // The start address of this merged section in the output file.
963 Value output_start_address_
;
964 // A hash table which maps offsets in the input section to output
965 // addresses. This only maps specific offsets, not all offsets.
966 Output_addresses output_addresses_
;
969 // This POD class is holds the value of a symbol. This is used for
970 // local symbols, and for all symbols during relocation processing.
971 // For special sections, such as SHF_MERGE sections, this calls a
972 // function to get the final symbol value.
978 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
981 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
982 is_ordinary_shndx_(false), is_section_symbol_(false),
983 is_tls_symbol_(false), has_output_value_(true)
984 { this->u_
.value
= 0; }
986 // Get the value of this symbol. OBJECT is the object in which this
987 // symbol is defined, and ADDEND is an addend to add to the value.
988 template<bool big_endian
>
990 value(const Sized_relobj
<size
, big_endian
>* object
, Value addend
) const
992 if (this->has_output_value_
)
993 return this->u_
.value
+ addend
;
996 gold_assert(this->is_ordinary_shndx_
);
997 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1002 // Set the value of this symbol in the output symbol table.
1004 set_output_value(Value value
)
1005 { this->u_
.value
= value
; }
1007 // For a section symbol in a merged section, we need more
1010 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1012 gold_assert(this->is_section_symbol_
);
1013 this->has_output_value_
= false;
1014 this->u_
.merged_symbol_value
= msv
;
1017 // Initialize the input to output map for a section symbol in a
1018 // merged section. We also initialize the value of a non-section
1019 // symbol in a merged section.
1021 initialize_input_to_output_map(const Relobj
* object
)
1023 if (!this->has_output_value_
)
1025 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1026 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1027 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1031 // Free the input to output map for a section symbol in a merged
1034 free_input_to_output_map()
1036 if (!this->has_output_value_
)
1037 this->u_
.merged_symbol_value
->free_input_to_output_map();
1040 // Set the value of the symbol from the input file. This is only
1041 // called by count_local_symbols, to communicate the value to
1042 // finalize_local_symbols.
1044 set_input_value(Value value
)
1045 { this->u_
.value
= value
; }
1047 // Return the input value. This is only called by
1048 // finalize_local_symbols and (in special cases) relocate_section.
1051 { return this->u_
.value
; }
1053 // Return whether this symbol should go into the output symbol
1056 needs_output_symtab_entry() const
1057 { return this->output_symtab_index_
!= -1U; }
1059 // Return the index in the output symbol table.
1061 output_symtab_index() const
1063 gold_assert(this->output_symtab_index_
!= 0);
1064 return this->output_symtab_index_
;
1067 // Set the index in the output symbol table.
1069 set_output_symtab_index(unsigned int i
)
1071 gold_assert(this->output_symtab_index_
== 0);
1072 this->output_symtab_index_
= i
;
1075 // Record that this symbol should not go into the output symbol
1078 set_no_output_symtab_entry()
1080 gold_assert(this->output_symtab_index_
== 0);
1081 this->output_symtab_index_
= -1U;
1084 // Set the index in the output dynamic symbol table.
1086 set_needs_output_dynsym_entry()
1088 gold_assert(!this->is_section_symbol());
1089 this->output_dynsym_index_
= 0;
1092 // Return whether this symbol should go into the output symbol
1095 needs_output_dynsym_entry() const
1097 return this->output_dynsym_index_
!= -1U;
1100 // Record that this symbol should go into the dynamic symbol table.
1102 set_output_dynsym_index(unsigned int i
)
1104 gold_assert(this->output_dynsym_index_
== 0);
1105 this->output_dynsym_index_
= i
;
1108 // Return the index in the output dynamic symbol table.
1110 output_dynsym_index() const
1112 gold_assert(this->output_dynsym_index_
!= 0
1113 && this->output_dynsym_index_
!= -1U);
1114 return this->output_dynsym_index_
;
1117 // Set the index of the input section in the input file.
1119 set_input_shndx(unsigned int i
, bool is_ordinary
)
1121 this->input_shndx_
= i
;
1122 // input_shndx_ field is a bitfield, so make sure that the value
1124 gold_assert(this->input_shndx_
== i
);
1125 this->is_ordinary_shndx_
= is_ordinary
;
1128 // Return the index of the input section in the input file.
1130 input_shndx(bool* is_ordinary
) const
1132 *is_ordinary
= this->is_ordinary_shndx_
;
1133 return this->input_shndx_
;
1136 // Whether this is a section symbol.
1138 is_section_symbol() const
1139 { return this->is_section_symbol_
; }
1141 // Record that this is a section symbol.
1143 set_is_section_symbol()
1145 gold_assert(!this->needs_output_dynsym_entry());
1146 this->is_section_symbol_
= true;
1149 // Record that this is a TLS symbol.
1152 { this->is_tls_symbol_
= true; }
1154 // Return TRUE if this is a TLS symbol.
1156 is_tls_symbol() const
1157 { return this->is_tls_symbol_
; }
1160 // The index of this local symbol in the output symbol table. This
1161 // will be -1 if the symbol should not go into the symbol table.
1162 unsigned int output_symtab_index_
;
1163 // The index of this local symbol in the dynamic symbol table. This
1164 // will be -1 if the symbol should not go into the symbol table.
1165 unsigned int output_dynsym_index_
;
1166 // The section index in the input file in which this symbol is
1168 unsigned int input_shndx_
: 28;
1169 // Whether the section index is an ordinary index, not a special
1171 bool is_ordinary_shndx_
: 1;
1172 // Whether this is a STT_SECTION symbol.
1173 bool is_section_symbol_
: 1;
1174 // Whether this is a STT_TLS symbol.
1175 bool is_tls_symbol_
: 1;
1176 // Whether this symbol has a value for the output file. This is
1177 // normally set to true during Layout::finalize, by
1178 // finalize_local_symbols. It will be false for a section symbol in
1179 // a merge section, as for such symbols we can not determine the
1180 // value to use in a relocation until we see the addend.
1181 bool has_output_value_
: 1;
1184 // This is used if has_output_value_ is true. Between
1185 // count_local_symbols and finalize_local_symbols, this is the
1186 // value in the input file. After finalize_local_symbols, it is
1187 // the value in the output file.
1189 // This is used if has_output_value_ is false. It points to the
1190 // information we need to get the value for a merge section.
1191 Merged_symbol_value
<size
>* merged_symbol_value
;
1195 // A GOT offset list. A symbol may have more than one GOT offset
1196 // (e.g., when mixing modules compiled with two different TLS models),
1197 // but will usually have at most one. GOT_TYPE identifies the type of
1198 // GOT entry; its values are specific to each target.
1200 class Got_offset_list
1204 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
1207 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
1208 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
1213 if (this->got_next_
!= NULL
)
1215 delete this->got_next_
;
1216 this->got_next_
= NULL
;
1220 // Initialize the fields to their default values.
1224 this->got_type_
= -1U;
1225 this->got_offset_
= 0;
1226 this->got_next_
= NULL
;
1229 // Set the offset for the GOT entry of type GOT_TYPE.
1231 set_offset(unsigned int got_type
, unsigned int got_offset
)
1233 if (this->got_type_
== -1U)
1235 this->got_type_
= got_type
;
1236 this->got_offset_
= got_offset
;
1240 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1242 if (g
->got_type_
== got_type
)
1244 g
->got_offset_
= got_offset
;
1248 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1249 g
->got_next_
= this->got_next_
;
1250 this->got_next_
= g
;
1254 // Return the offset for a GOT entry of type GOT_TYPE.
1256 get_offset(unsigned int got_type
) const
1258 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1260 if (g
->got_type_
== got_type
)
1261 return g
->got_offset_
;
1267 unsigned int got_type_
;
1268 unsigned int got_offset_
;
1269 Got_offset_list
* got_next_
;
1272 // This type is used to modify relocations for -fsplit-stack. It is
1273 // indexed by relocation index, and means that the relocation at that
1274 // index should use the symbol from the vector, rather than the one
1275 // indicated by the relocation.
1277 class Reloc_symbol_changes
1280 Reloc_symbol_changes(size_t count
)
1285 set(size_t i
, Symbol
* sym
)
1286 { this->vec_
[i
] = sym
; }
1289 operator[](size_t i
) const
1290 { return this->vec_
[i
]; }
1293 std::vector
<Symbol
*> vec_
;
1296 // A regular object file. This is size and endian specific.
1298 template<int size
, bool big_endian
>
1299 class Sized_relobj
: public Relobj
1302 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1303 typedef std::vector
<Symbol
*> Symbols
;
1304 typedef std::vector
<Symbol_value
<size
> > Local_values
;
1306 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1308 Sized_relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
,
1309 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
1313 // Checks if the offset of input section SHNDX within its output
1314 // section is invalid.
1316 is_output_section_offset_invalid(unsigned int shndx
) const
1317 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1319 // Set up the object file based on TARGET.
1322 { this->do_setup(); }
1324 // Return the number of symbols. This is only valid after
1325 // Object::add_symbols has been called.
1327 symbol_count() const
1328 { return this->local_symbol_count_
+ this->symbols_
.size(); }
1330 // If SYM is the index of a global symbol in the object file's
1331 // symbol table, return the Symbol object. Otherwise, return NULL.
1333 global_symbol(unsigned int sym
) const
1335 if (sym
>= this->local_symbol_count_
)
1337 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
1338 return this->symbols_
[sym
- this->local_symbol_count_
];
1343 // Return the section index of symbol SYM. Set *VALUE to its value
1344 // in the object file. Set *IS_ORDINARY if this is an ordinary
1345 // section index, not a special code between SHN_LORESERVE and
1346 // SHN_HIRESERVE. Note that for a symbol which is not defined in
1347 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
1348 // it will not return the final value of the symbol in the link.
1350 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
1352 // Return a pointer to the Symbol_value structure which holds the
1353 // value of a local symbol.
1354 const Symbol_value
<size
>*
1355 local_symbol(unsigned int sym
) const
1357 gold_assert(sym
< this->local_values_
.size());
1358 return &this->local_values_
[sym
];
1361 // Return the index of local symbol SYM in the ordinary symbol
1362 // table. A value of -1U means that the symbol is not being output.
1364 symtab_index(unsigned int sym
) const
1366 gold_assert(sym
< this->local_values_
.size());
1367 return this->local_values_
[sym
].output_symtab_index();
1370 // Return the index of local symbol SYM in the dynamic symbol
1371 // table. A value of -1U means that the symbol is not being output.
1373 dynsym_index(unsigned int sym
) const
1375 gold_assert(sym
< this->local_values_
.size());
1376 return this->local_values_
[sym
].output_dynsym_index();
1379 // Return the input section index of local symbol SYM.
1381 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
1383 gold_assert(sym
< this->local_values_
.size());
1384 return this->local_values_
[sym
].input_shndx(is_ordinary
);
1387 // Record that local symbol SYM needs a dynamic symbol entry.
1389 set_needs_output_dynsym_entry(unsigned int sym
)
1391 gold_assert(sym
< this->local_values_
.size());
1392 this->local_values_
[sym
].set_needs_output_dynsym_entry();
1395 // Return whether the local symbol SYMNDX has a GOT offset.
1396 // For TLS symbols, the GOT entry will hold its tp-relative offset.
1398 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1400 Local_got_offsets::const_iterator p
=
1401 this->local_got_offsets_
.find(symndx
);
1402 return (p
!= this->local_got_offsets_
.end()
1403 && p
->second
->get_offset(got_type
) != -1U);
1406 // Return the GOT offset of the local symbol SYMNDX.
1408 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1410 Local_got_offsets::const_iterator p
=
1411 this->local_got_offsets_
.find(symndx
);
1412 gold_assert(p
!= this->local_got_offsets_
.end());
1413 unsigned int off
= p
->second
->get_offset(got_type
);
1414 gold_assert(off
!= -1U);
1418 // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
1420 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1421 unsigned int got_offset
)
1423 Local_got_offsets::const_iterator p
=
1424 this->local_got_offsets_
.find(symndx
);
1425 if (p
!= this->local_got_offsets_
.end())
1426 p
->second
->set_offset(got_type
, got_offset
);
1429 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1430 std::pair
<Local_got_offsets::iterator
, bool> ins
=
1431 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
1432 gold_assert(ins
.second
);
1436 // Get the offset of input section SHNDX within its output section.
1437 // This is -1 if the input section requires a special mapping, such
1438 // as a merge section. The output section can be found in the
1439 // output_sections_ field of the parent class Relobj.
1441 get_output_section_offset(unsigned int shndx
) const
1443 gold_assert(shndx
< this->section_offsets_
.size());
1444 return this->section_offsets_
[shndx
];
1447 // Return the name of the symbol that spans the given offset in the
1448 // specified section in this object. This is used only for error
1449 // messages and is not particularly efficient.
1451 get_symbol_location_info(unsigned int shndx
, off_t offset
,
1452 Symbol_location_info
* info
);
1454 // Look for a kept section corresponding to the given discarded section,
1455 // and return its output address. This is used only for relocations in
1456 // debugging sections.
1458 map_to_kept_section(unsigned int shndx
, bool* found
) const;
1460 // Make section offset invalid. This is needed for relaxation.
1462 invalidate_section_offset(unsigned int shndx
)
1463 { this->do_invalidate_section_offset(shndx
); }
1470 // Read the symbols.
1472 do_read_symbols(Read_symbols_data
*);
1474 // Return the number of local symbols.
1476 do_local_symbol_count() const
1477 { return this->local_symbol_count_
; }
1479 // Lay out the input sections.
1481 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
1483 // Layout sections whose layout was deferred while waiting for
1484 // input files from a plugin.
1486 do_layout_deferred_sections(Layout
*);
1488 // Add the symbols to the symbol table.
1490 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
1494 do_read_relocs(Read_relocs_data
*);
1496 // Process the relocs to find list of referenced sections. Used only
1497 // during garbage collection.
1499 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1501 // Scan the relocs and adjust the symbol table.
1503 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1505 // Count the local symbols.
1507 do_count_local_symbols(Stringpool_template
<char>*,
1508 Stringpool_template
<char>*);
1510 // Finalize the local symbols.
1512 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
1514 // Set the offset where local dynamic symbol information will be stored.
1516 do_set_local_dynsym_indexes(unsigned int);
1518 // Set the offset where local dynamic symbol information will be stored.
1520 do_set_local_dynsym_offset(off_t
);
1522 // Relocate the input sections and write out the local symbols.
1524 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
1526 // Get the size of a section.
1528 do_section_size(unsigned int shndx
)
1529 { return this->elf_file_
.section_size(shndx
); }
1531 // Get the name of a section.
1533 do_section_name(unsigned int shndx
)
1534 { return this->elf_file_
.section_name(shndx
); }
1536 // Return the location of the contents of a section.
1538 do_section_contents(unsigned int shndx
)
1539 { return this->elf_file_
.section_contents(shndx
); }
1541 // Return section flags.
1543 do_section_flags(unsigned int shndx
);
1545 // Return section entsize.
1547 do_section_entsize(unsigned int shndx
);
1549 // Return section address.
1551 do_section_address(unsigned int shndx
)
1552 { return this->elf_file_
.section_addr(shndx
); }
1554 // Return section type.
1556 do_section_type(unsigned int shndx
)
1557 { return this->elf_file_
.section_type(shndx
); }
1559 // Return the section link field.
1561 do_section_link(unsigned int shndx
)
1562 { return this->elf_file_
.section_link(shndx
); }
1564 // Return the section info field.
1566 do_section_info(unsigned int shndx
)
1567 { return this->elf_file_
.section_info(shndx
); }
1569 // Return the section alignment.
1571 do_section_addralign(unsigned int shndx
)
1572 { return this->elf_file_
.section_addralign(shndx
); }
1574 // Return the Xindex structure to use.
1576 do_initialize_xindex();
1578 // Get symbol counts.
1580 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
1582 // Get the offset of a section.
1584 do_output_section_offset(unsigned int shndx
) const
1586 Address off
= this->get_output_section_offset(shndx
);
1587 if (off
== invalid_address
)
1592 // Set the offset of a section.
1594 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1596 gold_assert(shndx
< this->section_offsets_
.size());
1597 this->section_offsets_
[shndx
] = convert_types
<Address
, uint64_t>(off
);
1600 // Set the offset of a section to invalid_address.
1602 do_invalidate_section_offset(unsigned int shndx
)
1604 gold_assert(shndx
< this->section_offsets_
.size());
1605 this->section_offsets_
[shndx
] = invalid_address
;
1608 // Adjust a section index if necessary.
1610 adjust_shndx(unsigned int shndx
)
1612 if (shndx
>= elfcpp::SHN_LORESERVE
)
1613 shndx
+= this->elf_file_
.large_shndx_offset();
1617 // Initialize input to output maps for section symbols in merged
1620 initialize_input_to_output_maps();
1622 // Free the input to output maps for section symbols in merged
1625 free_input_to_output_maps();
1627 // Return symbol table section index.
1629 symtab_shndx() const
1630 { return this->symtab_shndx_
; }
1632 // Allow a child class to access the ELF file.
1633 elfcpp::Elf_file
<size
, big_endian
, Object
>*
1635 { return &this->elf_file_
; }
1637 // Allow a child class to access the local values.
1640 { return &this->local_values_
; }
1642 // Views and sizes when relocating.
1645 unsigned char* view
;
1646 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
1648 section_size_type view_size
;
1649 bool is_input_output_view
;
1650 bool is_postprocessing_view
;
1653 typedef std::vector
<View_size
> Views
;
1655 // This may be overriden by a child class.
1657 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1658 const unsigned char* pshdrs
, Views
* pviews
);
1662 typedef Sized_relobj
<size
, big_endian
> This
;
1663 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
1664 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1665 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1666 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
1668 // To keep track of discarded comdat sections, we need to map a member
1669 // section index to the object and section index of the corresponding
1671 struct Kept_comdat_section
1673 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
1674 : object(a_object
), shndx(a_shndx
)
1679 typedef std::map
<unsigned int, Kept_comdat_section
>
1680 Kept_comdat_section_table
;
1682 // Find the SHT_SYMTAB section, given the section headers.
1684 find_symtab(const unsigned char* pshdrs
);
1686 // Return whether SHDR has the right flags for a GNU style exception
1689 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
1691 // Return whether there is a section named .eh_frame which might be
1692 // a GNU style exception frame section.
1694 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
1695 section_size_type names_size
) const;
1697 // Whether to include a section group in the link.
1699 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
1700 const unsigned char*, const char *, section_size_type
,
1701 std::vector
<bool>*);
1703 // Whether to include a linkonce section in the link.
1705 include_linkonce_section(Layout
*, unsigned int, const char*,
1706 const elfcpp::Shdr
<size
, big_endian
>&);
1708 // Layout an input section.
1710 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
1711 typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
1712 unsigned int reloc_type
);
1714 // Write section data to the output file. Record the views and
1715 // sizes in VIEWS for use when relocating.
1717 write_sections(const unsigned char* pshdrs
, Output_file
*, Views
*);
1719 // Relocate the sections in the output file.
1721 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1722 const unsigned char* pshdrs
, Views
* pviews
)
1723 { this->do_relocate_sections(symtab
, layout
, pshdrs
, pviews
); }
1725 // Scan the input relocations for --emit-relocs.
1727 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
1728 const Read_relocs_data::Relocs_list::iterator
&);
1730 // Scan the input relocations for --emit-relocs, templatized on the
1731 // type of the relocation section.
1732 template<int sh_type
>
1734 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
1735 const unsigned char* plocal_syms
,
1736 const Read_relocs_data::Relocs_list::iterator
&,
1737 Relocatable_relocs
*);
1739 // Emit the relocs for --emit-relocs.
1741 emit_relocs(const Relocate_info
<size
, big_endian
>*, unsigned int,
1742 unsigned int sh_type
, const unsigned char* prelocs
,
1743 size_t reloc_count
, Output_section
*, Address output_offset
,
1744 unsigned char* view
, Address address
,
1745 section_size_type view_size
,
1746 unsigned char* reloc_view
, section_size_type reloc_view_size
);
1748 // Emit the relocs for --emit-relocs, templatized on the type of the
1749 // relocation section.
1750 template<int sh_type
>
1752 emit_relocs_reltype(const Relocate_info
<size
, big_endian
>*, unsigned int,
1753 const unsigned char* prelocs
, size_t reloc_count
,
1754 Output_section
*, Address output_offset
,
1755 unsigned char* view
, Address address
,
1756 section_size_type view_size
,
1757 unsigned char* reloc_view
,
1758 section_size_type reloc_view_size
);
1760 // A type shared by split_stack_adjust_reltype and find_functions.
1761 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
1763 // Check for -fsplit-stack routines calling non-split-stack routines.
1765 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
1766 unsigned int sh_type
, unsigned int shndx
,
1767 const unsigned char* prelocs
, size_t reloc_count
,
1768 unsigned char* view
, section_size_type view_size
,
1769 Reloc_symbol_changes
** reloc_map
);
1771 template<int sh_type
>
1773 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
1774 unsigned int shndx
, const unsigned char* prelocs
,
1775 size_t reloc_count
, unsigned char* view
,
1776 section_size_type view_size
,
1777 Reloc_symbol_changes
** reloc_map
);
1779 // Find all functions in a section.
1781 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
1784 // Write out the local symbols.
1786 write_local_symbols(Output_file
*,
1787 const Stringpool_template
<char>*,
1788 const Stringpool_template
<char>*,
1789 Output_symtab_xindex
*,
1790 Output_symtab_xindex
*);
1792 // Clear the local symbol information.
1794 clear_local_symbols()
1796 this->local_values_
.clear();
1797 this->local_got_offsets_
.clear();
1800 // Record a mapping from discarded section SHNDX to the corresponding
1803 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
1804 unsigned int kept_shndx
)
1806 Kept_comdat_section
kept(kept_object
, kept_shndx
);
1807 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
1810 // Find the kept section corresponding to the discarded section
1811 // SHNDX. Return true if found.
1813 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
1814 unsigned int* kept_shndx
) const
1816 typename
Kept_comdat_section_table::const_iterator p
=
1817 this->kept_comdat_sections_
.find(shndx
);
1818 if (p
== this->kept_comdat_sections_
.end())
1820 *kept_object
= p
->second
.object
;
1821 *kept_shndx
= p
->second
.shndx
;
1825 // The GOT offsets of local symbols. This map also stores GOT offsets
1826 // for tp-relative offsets for TLS symbols.
1827 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
1829 // The TLS GOT offsets of local symbols. The map stores the offsets
1830 // for either a single GOT entry that holds the module index of a TLS
1831 // symbol, or a pair of GOT entries containing the module index and
1832 // dtv-relative offset.
1833 struct Tls_got_entry
1835 Tls_got_entry(int got_offset
, bool have_pair
)
1836 : got_offset_(got_offset
),
1837 have_pair_(have_pair
)
1842 typedef Unordered_map
<unsigned int, Tls_got_entry
> Local_tls_got_offsets
;
1844 // Saved information for sections whose layout was deferred.
1845 struct Deferred_layout
1847 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1848 Deferred_layout(unsigned int shndx
, const char* name
,
1849 const unsigned char* pshdr
,
1850 unsigned int reloc_shndx
, unsigned int reloc_type
)
1851 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
1852 reloc_type_(reloc_type
)
1854 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
1856 unsigned int shndx_
;
1858 unsigned int reloc_shndx_
;
1859 unsigned int reloc_type_
;
1860 unsigned char shdr_data_
[shdr_size
];
1863 // General access to the ELF file.
1864 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
1865 // Index of SHT_SYMTAB section.
1866 unsigned int symtab_shndx_
;
1867 // The number of local symbols.
1868 unsigned int local_symbol_count_
;
1869 // The number of local symbols which go into the output file.
1870 unsigned int output_local_symbol_count_
;
1871 // The number of local symbols which go into the output file's dynamic
1873 unsigned int output_local_dynsym_count_
;
1874 // The entries in the symbol table for the external symbols.
1876 // Number of symbols defined in object file itself.
1877 size_t defined_count_
;
1878 // File offset for local symbols.
1879 off_t local_symbol_offset_
;
1880 // File offset for local dynamic symbols.
1881 off_t local_dynsym_offset_
;
1882 // Values of local symbols.
1883 Local_values local_values_
;
1884 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1885 // for TLS symbols, indexed by symbol number.
1886 Local_got_offsets local_got_offsets_
;
1887 // For each input section, the offset of the input section in its
1888 // output section. This is INVALID_ADDRESS if the input section requires a
1890 std::vector
<Address
> section_offsets_
;
1891 // Table mapping discarded comdat sections to corresponding kept sections.
1892 Kept_comdat_section_table kept_comdat_sections_
;
1893 // Whether this object has a GNU style .eh_frame section.
1895 // If this object has a GNU style .eh_frame section that is discarded in
1896 // output, record the index here. Otherwise it is -1U.
1897 unsigned int discarded_eh_frame_shndx_
;
1898 // The list of sections whose layout was deferred.
1899 std::vector
<Deferred_layout
> deferred_layout_
;
1902 // A class to manage the list of all objects.
1908 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
1911 // The type of the list of input relocateable objects.
1912 typedef std::vector
<Relobj
*> Relobj_list
;
1913 typedef Relobj_list::const_iterator Relobj_iterator
;
1915 // The type of the list of input dynamic objects.
1916 typedef std::vector
<Dynobj
*> Dynobj_list
;
1917 typedef Dynobj_list::const_iterator Dynobj_iterator
;
1919 // Add an object to the list. Return true if all is well, or false
1920 // if this object should be ignored.
1922 add_object(Object
*);
1924 // Start processing an archive.
1926 archive_start(Archive
*);
1928 // Stop processing an archive.
1930 archive_stop(Archive
*);
1932 // For each dynamic object, check whether we've seen all of its
1933 // explicit dependencies.
1935 check_dynamic_dependencies() const;
1937 // Return whether an object was found in the system library
1940 found_in_system_library_directory(const Object
*) const;
1942 // Print symbol counts.
1944 print_symbol_counts(const Symbol_table
*) const;
1946 // Iterate over all regular objects.
1949 relobj_begin() const
1950 { return this->relobj_list_
.begin(); }
1954 { return this->relobj_list_
.end(); }
1956 // Iterate over all dynamic objects.
1959 dynobj_begin() const
1960 { return this->dynobj_list_
.begin(); }
1964 { return this->dynobj_list_
.end(); }
1966 // Return whether we have seen any dynamic objects.
1969 { return !this->dynobj_list_
.empty(); }
1971 // Return the number of input objects.
1973 number_of_input_objects() const
1974 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
1977 Input_objects(const Input_objects
&);
1978 Input_objects
& operator=(const Input_objects
&);
1980 // The list of ordinary objects included in the link.
1981 Relobj_list relobj_list_
;
1982 // The list of dynamic objects included in the link.
1983 Dynobj_list dynobj_list_
;
1984 // SONAMEs that we have seen.
1985 Unordered_set
<std::string
> sonames_
;
1986 // Manage cross-references if requested.
1990 // Some of the information we pass to the relocation routines. We
1991 // group this together to avoid passing a dozen different arguments.
1993 template<int size
, bool big_endian
>
1994 struct Relocate_info
1997 const Symbol_table
* symtab
;
1999 const Layout
* layout
;
2000 // Object being relocated.
2001 Sized_relobj
<size
, big_endian
>* object
;
2002 // Section index of relocation section.
2003 unsigned int reloc_shndx
;
2004 // Section header of relocation section.
2005 const unsigned char* reloc_shdr
;
2006 // Section index of section being relocated.
2007 unsigned int data_shndx
;
2008 // Section header of data section.
2009 const unsigned char* data_shdr
;
2011 // Return a string showing the location of a relocation. This is
2012 // only used for error messages.
2014 location(size_t relnum
, off_t reloffset
) const;
2017 // Return whether INPUT_FILE contains an ELF object start at file
2018 // offset OFFSET. This sets *START to point to a view of the start of
2019 // the file. It sets *READ_SIZE to the number of bytes in the view.
2022 is_elf_object(Input_file
* input_file
, off_t offset
,
2023 const unsigned char** start
, int *read_size
);
2025 // Return an Object appropriate for the input file. P is BYTES long,
2026 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2027 // this sees an object the linker is not configured to support, it
2028 // sets *PUNCONFIGURED to true and returns NULL without giving an
2032 make_elf_object(const std::string
& name
, Input_file
*,
2033 off_t offset
, const unsigned char* p
,
2034 section_offset_type bytes
, bool* punconfigured
);
2036 } // end namespace gold
2038 #endif // !defined(GOLD_OBJECT_H)