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)