1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
30 #include "elfcpp_file.h"
38 class General_options;
45 class Output_symtab_xindex;
48 class Object_merge_map;
49 class Relocatable_relocs;
52 template<typename Stringpool_char>
53 class Stringpool_template;
55 // Data to pass from read_symbols() to add_symbols().
57 struct Read_symbols_data
60 : section_headers(NULL), section_names(NULL), symbols(NULL),
61 symbol_names(NULL), versym(NULL), verdef(NULL), verneed(NULL)
67 File_view* section_headers;
69 File_view* section_names;
70 // Size of section name data in bytes.
71 section_size_type section_names_size;
74 // Size of symbol data in bytes.
75 section_size_type symbols_size;
76 // Offset of external symbols within symbol data. This structure
77 // sometimes contains only external symbols, in which case this will
78 // be zero. Sometimes it contains all symbols.
79 section_offset_type external_symbols_offset;
81 File_view* symbol_names;
82 // Size of symbol name data in bytes.
83 section_size_type symbol_names_size;
85 // Version information. This is only used on dynamic objects.
86 // Version symbol data (from SHT_GNU_versym section).
88 section_size_type versym_size;
89 // Version definition data (from SHT_GNU_verdef section).
91 section_size_type verdef_size;
92 unsigned int verdef_info;
93 // Needed version data (from SHT_GNU_verneed section).
95 section_size_type verneed_size;
96 unsigned int verneed_info;
99 // Information used to print error messages.
101 struct Symbol_location_info
103 std::string source_file;
104 std::string enclosing_symbol_name;
108 // Data about a single relocation section. This is read in
109 // read_relocs and processed in scan_relocs.
111 struct Section_relocs
118 { delete this->contents; }
120 // Index of reloc section.
121 unsigned int reloc_shndx;
122 // Index of section that relocs apply to.
123 unsigned int data_shndx;
124 // Contents of reloc section.
126 // Reloc section type.
127 unsigned int sh_type;
128 // Number of reloc entries.
131 Output_section* output_section;
132 // Whether this section has special handling for offsets.
133 bool needs_special_offset_handling;
134 // Whether the data section is allocated (has the SHF_ALLOC flag set).
135 bool is_data_section_allocated;
138 // Relocations in an object file. This is read in read_relocs and
139 // processed in scan_relocs.
141 struct Read_relocs_data
144 : local_symbols(NULL)
148 { delete this->local_symbols; }
150 typedef std::vector<Section_relocs> Relocs_list;
153 // The local symbols.
154 File_view* local_symbols;
157 // The Xindex class manages section indexes for objects with more than
163 Xindex(int large_shndx_offset)
164 : large_shndx_offset_(large_shndx_offset), symtab_xindex_()
167 // Initialize the symtab_xindex_ array, given the object and the
168 // section index of the symbol table to use.
169 template<int size, bool big_endian>
171 initialize_symtab_xindex(Object*, unsigned int symtab_shndx);
173 // Read in the symtab_xindex_ array, given its section index.
174 // PSHDRS may optionally point to the section headers.
175 template<int size, bool big_endian>
177 read_symtab_xindex(Object*, unsigned int xindex_shndx,
178 const unsigned char* pshdrs);
180 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
181 // real section index.
183 sym_xindex_to_shndx(Object* object, unsigned int symndx);
186 // The type of the array giving the real section index for symbols
187 // whose st_shndx field holds SHN_XINDEX.
188 typedef std::vector<unsigned int> Symtab_xindex;
190 // Adjust a section index if necessary. This should only be called
191 // for ordinary section indexes.
193 adjust_shndx(unsigned int shndx)
195 if (shndx >= elfcpp::SHN_LORESERVE)
196 shndx += this->large_shndx_offset_;
200 // Adjust to apply to large section indexes.
201 int large_shndx_offset_;
202 // The data from the SHT_SYMTAB_SHNDX section.
203 Symtab_xindex symtab_xindex_;
206 // A GOT offset list. A symbol may have more than one GOT offset
207 // (e.g., when mixing modules compiled with two different TLS models),
208 // but will usually have at most one. GOT_TYPE identifies the type of
209 // GOT entry; its values are specific to each target.
211 class Got_offset_list
215 : got_type_(-1U), got_offset_(0), got_next_(NULL)
218 Got_offset_list(unsigned int got_type, unsigned int got_offset)
219 : got_type_(got_type), got_offset_(got_offset), got_next_(NULL)
224 if (this->got_next_ != NULL)
226 delete this->got_next_;
227 this->got_next_ = NULL;
231 // Initialize the fields to their default values.
235 this->got_type_ = -1U;
236 this->got_offset_ = 0;
237 this->got_next_ = NULL;
240 // Set the offset for the GOT entry of type GOT_TYPE.
242 set_offset(unsigned int got_type, unsigned int got_offset)
244 if (this->got_type_ == -1U)
246 this->got_type_ = got_type;
247 this->got_offset_ = got_offset;
251 for (Got_offset_list* g = this; g != NULL; g = g->got_next_)
253 if (g->got_type_ == got_type)
255 g->got_offset_ = got_offset;
259 Got_offset_list* g = new Got_offset_list(got_type, got_offset);
260 g->got_next_ = this->got_next_;
265 // Return the offset for a GOT entry of type GOT_TYPE.
267 get_offset(unsigned int got_type) const
269 for (const Got_offset_list* g = this; g != NULL; g = g->got_next_)
271 if (g->got_type_ == got_type)
272 return g->got_offset_;
277 // Return a pointer to the list, or NULL if the list is empty.
278 const Got_offset_list*
281 if (this->got_type_ == -1U)
286 // Abstract visitor class for iterating over GOT offsets.
298 visit(unsigned int, unsigned int) = 0;
301 // Loop over all GOT offset entries, calling a visitor class V for each.
303 for_all_got_offsets(Visitor* v) const
305 if (this->got_type_ == -1U)
307 for (const Got_offset_list* g = this; g != NULL; g = g->got_next_)
308 v->visit(g->got_type_, g->got_offset_);
312 unsigned int got_type_;
313 unsigned int got_offset_;
314 Got_offset_list* got_next_;
317 // Object is an abstract base class which represents either a 32-bit
318 // or a 64-bit input object. This can be a regular object file
319 // (ET_REL) or a shared object (ET_DYN).
324 typedef std::vector<Symbol*> Symbols;
326 // NAME is the name of the object as we would report it to the user
327 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
328 // used to read the file. OFFSET is the offset within the input
329 // file--0 for a .o or .so file, something else for a .a file.
330 Object(const std::string& name, Input_file* input_file, bool is_dynamic,
332 : name_(name), input_file_(input_file), offset_(offset), shnum_(-1U),
333 is_dynamic_(is_dynamic), is_needed_(false), uses_split_stack_(false),
334 has_no_split_stack_(false), no_export_(false),
335 is_in_system_directory_(false), xindex_(NULL)
337 if (input_file != NULL)
339 input_file->file().add_object();
340 this->is_in_system_directory_ = input_file->is_in_system_directory();
346 if (this->input_file_ != NULL)
347 this->input_file_->file().remove_object();
350 // Return the name of the object as we would report it to the tuser.
353 { return this->name_; }
355 // Get the offset into the file.
358 { return this->offset_; }
360 // Return whether this is a dynamic object.
363 { return this->is_dynamic_; }
365 // Return whether this object is needed--true if it is a dynamic
366 // object which defines some symbol referenced by a regular object.
367 // We keep the flag here rather than in Dynobj for convenience when
371 { return this->is_needed_; }
373 // Record that this object is needed.
376 { this->is_needed_ = true; }
378 // Return whether this object was compiled with -fsplit-stack.
380 uses_split_stack() const
381 { return this->uses_split_stack_; }
383 // Return whether this object contains any functions compiled with
384 // the no_split_stack attribute.
386 has_no_split_stack() const
387 { return this->has_no_split_stack_; }
389 // Returns NULL for Objects that are not plugin objects. This method
390 // is overridden in the Pluginobj class.
393 { return this->do_pluginobj(); }
395 // Get the file. We pass on const-ness.
399 gold_assert(this->input_file_ != NULL);
400 return this->input_file_;
406 gold_assert(this->input_file_ != NULL);
407 return this->input_file_;
410 // Lock the underlying file.
414 if (this->input_file_ != NULL)
415 this->input_file_->file().lock(t);
418 // Unlock the underlying file.
420 unlock(const Task* t)
422 if (this->input_file_ != NULL)
423 this->input_file()->file().unlock(t);
426 // Return whether the underlying file is locked.
429 { return this->input_file_ != NULL && this->input_file_->file().is_locked(); }
431 // Return the token, so that the task can be queued.
435 if (this->input_file_ == NULL)
437 return this->input_file()->file().token();
440 // Release the underlying file.
444 if (this->input_file_ != NULL)
445 this->input_file()->file().release();
448 // Return whether we should just read symbols from this file.
451 { return this->input_file()->just_symbols(); }
453 // Return whether this is an incremental object.
455 is_incremental() const
456 { return this->do_is_incremental(); }
458 // Return the last modified time of the file.
461 { return this->do_get_mtime(); }
463 // Get the number of sections.
466 { return this->shnum_; }
468 // Return a view of the contents of a section. Set *PLEN to the
469 // size. CACHE is a hint as in File_read::get_view.
471 section_contents(unsigned int shndx, section_size_type* plen, bool cache);
473 // Adjust a symbol's section index as needed. SYMNDX is the index
474 // of the symbol and SHNDX is the symbol's section from
475 // get_st_shndx. This returns the section index. It sets
476 // *IS_ORDINARY to indicate whether this is a normal section index,
477 // rather than a special code between SHN_LORESERVE and
480 adjust_sym_shndx(unsigned int symndx, unsigned int shndx, bool* is_ordinary)
482 if (shndx < elfcpp::SHN_LORESERVE)
484 else if (shndx == elfcpp::SHN_XINDEX)
486 if (this->xindex_ == NULL)
487 this->xindex_ = this->do_initialize_xindex();
488 shndx = this->xindex_->sym_xindex_to_shndx(this, symndx);
492 *is_ordinary = false;
496 // Return the size of a section given a section index.
498 section_size(unsigned int shndx)
499 { return this->do_section_size(shndx); }
501 // Return the name of a section given a section index.
503 section_name(unsigned int shndx)
504 { return this->do_section_name(shndx); }
506 // Return the section flags given a section index.
508 section_flags(unsigned int shndx)
509 { return this->do_section_flags(shndx); }
511 // Return the section entsize given a section index.
513 section_entsize(unsigned int shndx)
514 { return this->do_section_entsize(shndx); }
516 // Return the section address given a section index.
518 section_address(unsigned int shndx)
519 { return this->do_section_address(shndx); }
521 // Return the section type given a section index.
523 section_type(unsigned int shndx)
524 { return this->do_section_type(shndx); }
526 // Return the section link field given a section index.
528 section_link(unsigned int shndx)
529 { return this->do_section_link(shndx); }
531 // Return the section info field given a section index.
533 section_info(unsigned int shndx)
534 { return this->do_section_info(shndx); }
536 // Return the required section alignment given a section index.
538 section_addralign(unsigned int shndx)
539 { return this->do_section_addralign(shndx); }
541 // Return the output section given a section index.
543 output_section(unsigned int shndx) const
544 { return this->do_output_section(shndx); }
546 // Given a section index, return the offset in the Output_section.
547 // The return value will be -1U if the section is specially mapped,
548 // such as a merge section.
550 output_section_offset(unsigned int shndx) const
551 { return this->do_output_section_offset(shndx); }
553 // Read the symbol information.
555 read_symbols(Read_symbols_data* sd)
556 { return this->do_read_symbols(sd); }
558 // Pass sections which should be included in the link to the Layout
559 // object, and record where the sections go in the output file.
561 layout(Symbol_table* symtab, Layout* layout, Read_symbols_data* sd)
562 { this->do_layout(symtab, layout, sd); }
564 // Add symbol information to the global symbol table.
566 add_symbols(Symbol_table* symtab, Read_symbols_data* sd, Layout *layout)
567 { this->do_add_symbols(symtab, sd, layout); }
569 // Add symbol information to the global symbol table.
570 Archive::Should_include
571 should_include_member(Symbol_table* symtab, Layout* layout,
572 Read_symbols_data* sd, std::string* why)
573 { return this->do_should_include_member(symtab, layout, sd, why); }
575 // Iterate over global symbols, calling a visitor class V for each.
577 for_all_global_symbols(Read_symbols_data* sd,
578 Library_base::Symbol_visitor_base* v)
579 { return this->do_for_all_global_symbols(sd, v); }
581 // Iterate over local symbols, calling a visitor class V for each GOT offset
582 // associated with a local symbol.
584 for_all_local_got_entries(Got_offset_list::Visitor* v) const
585 { this->do_for_all_local_got_entries(v); }
587 // Functions and types for the elfcpp::Elf_file interface. This
588 // permit us to use Object as the File template parameter for
591 // The View class is returned by view. It must support a single
592 // method, data(). This is trivial, because get_view does what we
597 View(const unsigned char* p)
606 const unsigned char* p_;
611 view(off_t file_offset, section_size_type data_size)
612 { return View(this->get_view(file_offset, data_size, true, true)); }
616 error(const char* format, ...) const ATTRIBUTE_PRINTF_2;
618 // A location in the file.
624 Location(off_t fo, section_size_type ds)
625 : file_offset(fo), data_size(ds)
629 // Get a View given a Location.
630 View view(Location loc)
631 { return View(this->get_view(loc.file_offset, loc.data_size, true, true)); }
633 // Get a view into the underlying file.
635 get_view(off_t start, section_size_type size, bool aligned, bool cache)
637 return this->input_file()->file().get_view(this->offset_, start, size,
641 // Get a lasting view into the underlying file.
643 get_lasting_view(off_t start, section_size_type size, bool aligned,
646 return this->input_file()->file().get_lasting_view(this->offset_, start,
647 size, aligned, cache);
650 // Read data from the underlying file.
652 read(off_t start, section_size_type size, void* p)
653 { this->input_file()->file().read(start + this->offset_, size, p); }
655 // Read multiple data from the underlying file.
657 read_multiple(const File_read::Read_multiple& rm)
658 { this->input_file()->file().read_multiple(this->offset_, rm); }
660 // Stop caching views in the underlying file.
662 clear_view_cache_marks()
664 if (this->input_file_ != NULL)
665 this->input_file_->file().clear_view_cache_marks();
668 // Get the number of global symbols defined by this object, and the
669 // number of the symbols whose final definition came from this
672 get_global_symbol_counts(const Symbol_table* symtab, size_t* defined,
674 { this->do_get_global_symbol_counts(symtab, defined, used); }
676 // Get the symbols defined in this object.
678 get_global_symbols() const
679 { return this->do_get_global_symbols(); }
681 // Set flag that this object was found in a system directory.
683 set_is_in_system_directory()
684 { this->is_in_system_directory_ = true; }
686 // Return whether this object was found in a system directory.
688 is_in_system_directory() const
689 { return this->is_in_system_directory_; }
691 // Return whether we found this object by searching a directory.
694 { return this->input_file()->will_search_for(); }
698 { return this->no_export_; }
701 set_no_export(bool value)
702 { this->no_export_ = value; }
704 // Return TRUE if the section is a compressed debug section, and set
705 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
707 section_is_compressed(unsigned int shndx,
708 section_size_type* uncompressed_size) const
709 { return this->do_section_is_compressed(shndx, uncompressed_size); }
711 // Return the index of the first incremental relocation for symbol SYMNDX.
713 get_incremental_reloc_base(unsigned int symndx) const
714 { return this->do_get_incremental_reloc_base(symndx); }
716 // Return the number of incremental relocations for symbol SYMNDX.
718 get_incremental_reloc_count(unsigned int symndx) const
719 { return this->do_get_incremental_reloc_count(symndx); }
722 // Returns NULL for Objects that are not plugin objects. This method
723 // is overridden in the Pluginobj class.
728 // Return TRUE if this is an incremental (unchanged) input file.
729 // We return FALSE by default; the incremental object classes
730 // override this method.
732 do_is_incremental() const
735 // Return the last modified time of the file. This method may be
736 // overridden for subclasses that don't use an actual file (e.g.,
737 // Incremental objects).
740 { return this->input_file()->file().get_mtime(); }
742 // Read the symbols--implemented by child class.
744 do_read_symbols(Read_symbols_data*) = 0;
746 // Lay out sections--implemented by child class.
748 do_layout(Symbol_table*, Layout*, Read_symbols_data*) = 0;
750 // Add symbol information to the global symbol table--implemented by
753 do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*) = 0;
755 virtual Archive::Should_include
756 do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
757 std::string* why) = 0;
759 // Iterate over global symbols, calling a visitor class V for each.
761 do_for_all_global_symbols(Read_symbols_data* sd,
762 Library_base::Symbol_visitor_base* v) = 0;
764 // Iterate over local symbols, calling a visitor class V for each GOT offset
765 // associated with a local symbol.
767 do_for_all_local_got_entries(Got_offset_list::Visitor* v) const = 0;
769 // Return the location of the contents of a section. Implemented by
772 do_section_contents(unsigned int shndx) = 0;
774 // Get the size of a section--implemented by child class.
776 do_section_size(unsigned int shndx) = 0;
778 // Get the name of a section--implemented by child class.
780 do_section_name(unsigned int shndx) = 0;
782 // Get section flags--implemented by child class.
784 do_section_flags(unsigned int shndx) = 0;
786 // Get section entsize--implemented by child class.
788 do_section_entsize(unsigned int shndx) = 0;
790 // Get section address--implemented by child class.
792 do_section_address(unsigned int shndx) = 0;
794 // Get section type--implemented by child class.
796 do_section_type(unsigned int shndx) = 0;
798 // Get section link field--implemented by child class.
800 do_section_link(unsigned int shndx) = 0;
802 // Get section info field--implemented by child class.
804 do_section_info(unsigned int shndx) = 0;
806 // Get section alignment--implemented by child class.
808 do_section_addralign(unsigned int shndx) = 0;
810 // Return the output section given a section index--implemented
812 virtual Output_section*
813 do_output_section(unsigned int) const
814 { gold_unreachable(); }
816 // Get the offset of a section--implemented by child class.
818 do_output_section_offset(unsigned int) const
819 { gold_unreachable(); }
821 // Return the Xindex structure to use.
823 do_initialize_xindex() = 0;
825 // Implement get_global_symbol_counts--implemented by child class.
827 do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const = 0;
829 virtual const Symbols*
830 do_get_global_symbols() const = 0;
832 // Set the number of sections.
835 { this->shnum_ = shnum; }
837 // Functions used by both Sized_relobj_file and Sized_dynobj.
839 // Read the section data into a Read_symbols_data object.
840 template<int size, bool big_endian>
842 read_section_data(elfcpp::Elf_file<size, big_endian, Object>*,
845 // Let the child class initialize the xindex object directly.
847 set_xindex(Xindex* xindex)
849 gold_assert(this->xindex_ == NULL);
850 this->xindex_ = xindex;
853 // If NAME is the name of a special .gnu.warning section, arrange
854 // for the warning to be issued. SHNDX is the section index.
855 // Return whether it is a warning section.
857 handle_gnu_warning_section(const char* name, unsigned int shndx,
860 // If NAME is the name of the special section which indicates that
861 // this object was compiled with -fsplit-stack, mark it accordingly,
862 // and return true. Otherwise return false.
864 handle_split_stack_section(const char* name);
866 // Return TRUE if the section is a compressed debug section, and set
867 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
869 do_section_is_compressed(unsigned int, section_size_type*) const
872 // Return the index of the first incremental relocation for symbol SYMNDX--
873 // implemented by child class.
875 do_get_incremental_reloc_base(unsigned int) const
876 { gold_unreachable(); }
878 // Return the number of incremental relocations for symbol SYMNDX--
879 // implemented by child class.
881 do_get_incremental_reloc_count(unsigned int) const
882 { gold_unreachable(); }
885 // This class may not be copied.
886 Object(const Object&);
887 Object& operator=(const Object&);
889 // Name of object as printed to user.
891 // For reading the file.
892 Input_file* input_file_;
893 // Offset within the file--0 for an object file, non-0 for an
896 // Number of input sections.
898 // Whether this is a dynamic object.
899 bool is_dynamic_ : 1;
900 // Whether this object is needed. This is only set for dynamic
901 // objects, and means that the object defined a symbol which was
902 // used by a reference from a regular object.
904 // Whether this object was compiled with -fsplit-stack.
905 bool uses_split_stack_ : 1;
906 // Whether this object contains any functions compiled with the
907 // no_split_stack attribute.
908 bool has_no_split_stack_ : 1;
909 // True if exclude this object from automatic symbol export.
910 // This is used only for archive objects.
912 // True if the object was found in a system directory.
913 bool is_in_system_directory_ : 1;
914 // Many sections for objects with more than SHN_LORESERVE sections.
918 // A regular object (ET_REL). This is an abstract base class itself.
919 // The implementation is the template class Sized_relobj_file.
921 class Relobj : public Object
924 Relobj(const std::string& name, Input_file* input_file, off_t offset = 0)
925 : Object(name, input_file, false, offset),
927 map_to_relocatable_relocs_(NULL),
928 object_merge_map_(NULL),
929 relocs_must_follow_section_writes_(false),
937 // During garbage collection, the Read_symbols_data pass for
938 // each object is stored as layout needs to be done after
942 { return this->sd_; }
944 // Decides which section names have to be included in the worklist
947 is_section_name_included(const char* name);
950 copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
951 unsigned int section_header_size);
954 set_symbols_data(Symbols_data* sd)
957 // During garbage collection, the Read_relocs pass for all objects
958 // is done before scanning the relocs. In that case, this->rd_ is
959 // used to store the information from Read_relocs for each object.
960 // This data is also used to compute the list of relevant sections.
963 { return this->rd_; }
966 set_relocs_data(Read_relocs_data* rd)
970 is_output_section_offset_invalid(unsigned int shndx) const = 0;
974 read_relocs(Read_relocs_data* rd)
975 { return this->do_read_relocs(rd); }
977 // Process the relocs, during garbage collection only.
979 gc_process_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd)
980 { return this->do_gc_process_relocs(symtab, layout, rd); }
982 // Scan the relocs and adjust the symbol table.
984 scan_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd)
985 { return this->do_scan_relocs(symtab, layout, rd); }
987 // The number of local symbols in the input symbol table.
989 local_symbol_count() const
990 { return this->do_local_symbol_count(); }
992 // The number of local symbols in the output symbol table.
994 output_local_symbol_count() const
995 { return this->do_output_local_symbol_count(); }
997 // The file offset for local symbols in the output symbol table.
999 local_symbol_offset() const
1000 { return this->do_local_symbol_offset(); }
1002 // Initial local symbol processing: count the number of local symbols
1003 // in the output symbol table and dynamic symbol table; add local symbol
1004 // names to *POOL and *DYNPOOL.
1006 count_local_symbols(Stringpool_template<char>* pool,
1007 Stringpool_template<char>* dynpool)
1008 { return this->do_count_local_symbols(pool, dynpool); }
1010 // Set the values of the local symbols, set the output symbol table
1011 // indexes for the local variables, and set the offset where local
1012 // symbol information will be stored. Returns the new local symbol index.
1014 finalize_local_symbols(unsigned int index, off_t off, Symbol_table* symtab)
1015 { return this->do_finalize_local_symbols(index, off, symtab); }
1017 // Set the output dynamic symbol table indexes for the local variables.
1019 set_local_dynsym_indexes(unsigned int index)
1020 { return this->do_set_local_dynsym_indexes(index); }
1022 // Set the offset where local dynamic symbol information will be stored.
1024 set_local_dynsym_offset(off_t off)
1025 { return this->do_set_local_dynsym_offset(off); }
1027 // Record a dynamic relocation against an input section from this object.
1029 add_dyn_reloc(unsigned int index)
1031 if (this->dyn_reloc_count_ == 0)
1032 this->first_dyn_reloc_ = index;
1033 ++this->dyn_reloc_count_;
1036 // Return the index of the first dynamic relocation.
1038 first_dyn_reloc() const
1039 { return this->first_dyn_reloc_; }
1041 // Return the count of dynamic relocations.
1043 dyn_reloc_count() const
1044 { return this->dyn_reloc_count_; }
1046 // Relocate the input sections and write out the local symbols.
1048 relocate(const Symbol_table* symtab, const Layout* layout, Output_file* of)
1049 { return this->do_relocate(symtab, layout, of); }
1051 // Return whether an input section is being included in the link.
1053 is_section_included(unsigned int shndx) const
1055 gold_assert(shndx < this->output_sections_.size());
1056 return this->output_sections_[shndx] != NULL;
1059 // The the output section of the input section with index SHNDX.
1060 // This is only used currently to remove a section from the link in
1063 set_output_section(unsigned int shndx, Output_section* os)
1065 gold_assert(shndx < this->output_sections_.size());
1066 this->output_sections_[shndx] = os;
1069 // Set the offset of an input section within its output section.
1071 set_section_offset(unsigned int shndx, uint64_t off)
1072 { this->do_set_section_offset(shndx, off); }
1074 // Return true if we need to wait for output sections to be written
1075 // before we can apply relocations. This is true if the object has
1076 // any relocations for sections which require special handling, such
1077 // as the exception frame section.
1079 relocs_must_follow_section_writes() const
1080 { return this->relocs_must_follow_section_writes_; }
1082 // Return the object merge map.
1085 { return this->object_merge_map_; }
1087 // Set the object merge map.
1089 set_merge_map(Object_merge_map* object_merge_map)
1091 gold_assert(this->object_merge_map_ == NULL);
1092 this->object_merge_map_ = object_merge_map;
1095 // Record the relocatable reloc info for an input reloc section.
1097 set_relocatable_relocs(unsigned int reloc_shndx, Relocatable_relocs* rr)
1099 gold_assert(reloc_shndx < this->shnum());
1100 (*this->map_to_relocatable_relocs_)[reloc_shndx] = rr;
1103 // Get the relocatable reloc info for an input reloc section.
1105 relocatable_relocs(unsigned int reloc_shndx)
1107 gold_assert(reloc_shndx < this->shnum());
1108 return (*this->map_to_relocatable_relocs_)[reloc_shndx];
1111 // Layout sections whose layout was deferred while waiting for
1112 // input files from a plugin.
1114 layout_deferred_sections(Layout* layout)
1115 { this->do_layout_deferred_sections(layout); }
1117 // Return the index of the first incremental relocation for symbol SYMNDX.
1118 virtual unsigned int
1119 do_get_incremental_reloc_base(unsigned int symndx) const
1120 { return this->reloc_bases_[symndx]; }
1122 // Return the number of incremental relocations for symbol SYMNDX.
1123 virtual unsigned int
1124 do_get_incremental_reloc_count(unsigned int symndx) const
1125 { return this->reloc_counts_[symndx]; }
1128 // The output section to be used for each input section, indexed by
1129 // the input section number. The output section is NULL if the
1130 // input section is to be discarded.
1131 typedef std::vector<Output_section*> Output_sections;
1133 // Read the relocs--implemented by child class.
1135 do_read_relocs(Read_relocs_data*) = 0;
1137 // Process the relocs--implemented by child class.
1139 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0;
1141 // Scan the relocs--implemented by child class.
1143 do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0;
1145 // Return the number of local symbols--implemented by child class.
1146 virtual unsigned int
1147 do_local_symbol_count() const = 0;
1149 // Return the number of output local symbols--implemented by child class.
1150 virtual unsigned int
1151 do_output_local_symbol_count() const = 0;
1153 // Return the file offset for local symbols--implemented by child class.
1155 do_local_symbol_offset() const = 0;
1157 // Count local symbols--implemented by child class.
1159 do_count_local_symbols(Stringpool_template<char>*,
1160 Stringpool_template<char>*) = 0;
1162 // Finalize the local symbols. Set the output symbol table indexes
1163 // for the local variables, and set the offset where local symbol
1164 // information will be stored.
1165 virtual unsigned int
1166 do_finalize_local_symbols(unsigned int, off_t, Symbol_table*) = 0;
1168 // Set the output dynamic symbol table indexes for the local variables.
1169 virtual unsigned int
1170 do_set_local_dynsym_indexes(unsigned int) = 0;
1172 // Set the offset where local dynamic symbol information will be stored.
1173 virtual unsigned int
1174 do_set_local_dynsym_offset(off_t) = 0;
1176 // Relocate the input sections and write out the local
1177 // symbols--implemented by child class.
1179 do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of) = 0;
1181 // Set the offset of a section--implemented by child class.
1183 do_set_section_offset(unsigned int shndx, uint64_t off) = 0;
1185 // Layout sections whose layout was deferred while waiting for
1186 // input files from a plugin--implemented by child class.
1188 do_layout_deferred_sections(Layout*) = 0;
1190 // Given a section index, return the corresponding Output_section.
1191 // The return value will be NULL if the section is not included in
1194 do_output_section(unsigned int shndx) const
1196 gold_assert(shndx < this->output_sections_.size());
1197 return this->output_sections_[shndx];
1200 // Return the vector mapping input sections to output sections.
1203 { return this->output_sections_; }
1205 const Output_sections&
1206 output_sections() const
1207 { return this->output_sections_; }
1209 // Set the size of the relocatable relocs array.
1211 size_relocatable_relocs()
1213 this->map_to_relocatable_relocs_ =
1214 new std::vector<Relocatable_relocs*>(this->shnum());
1217 // Record that we must wait for the output sections to be written
1218 // before applying relocations.
1220 set_relocs_must_follow_section_writes()
1221 { this->relocs_must_follow_section_writes_ = true; }
1223 // Allocate the array for counting incremental relocations.
1225 allocate_incremental_reloc_counts()
1227 unsigned int nsyms = this->do_get_global_symbols()->size();
1228 this->reloc_counts_ = new unsigned int[nsyms];
1229 gold_assert(this->reloc_counts_ != NULL);
1230 memset(this->reloc_counts_, 0, nsyms * sizeof(unsigned int));
1233 // Record a relocation in this object referencing global symbol SYMNDX.
1234 // Used for tracking incremental link information.
1236 count_incremental_reloc(unsigned int symndx)
1238 unsigned int nsyms = this->do_get_global_symbols()->size();
1239 gold_assert(symndx < nsyms);
1240 gold_assert(this->reloc_counts_ != NULL);
1241 ++this->reloc_counts_[symndx];
1244 // Finalize the incremental relocation information.
1246 finalize_incremental_relocs(Layout* layout, bool clear_counts);
1248 // Return the index of the next relocation to be written for global symbol
1249 // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
1251 next_incremental_reloc_index(unsigned int symndx)
1253 unsigned int nsyms = this->do_get_global_symbols()->size();
1255 gold_assert(this->reloc_counts_ != NULL);
1256 gold_assert(this->reloc_bases_ != NULL);
1257 gold_assert(symndx < nsyms);
1259 unsigned int counter = this->reloc_counts_[symndx]++;
1260 return this->reloc_bases_[symndx] + counter;
1264 // Mapping from input sections to output section.
1265 Output_sections output_sections_;
1266 // Mapping from input section index to the information recorded for
1267 // the relocations. This is only used for a relocatable link.
1268 std::vector<Relocatable_relocs*>* map_to_relocatable_relocs_;
1269 // Mappings for merge sections. This is managed by the code in the
1271 Object_merge_map* object_merge_map_;
1272 // Whether we need to wait for output sections to be written before
1273 // we can apply relocations.
1274 bool relocs_must_follow_section_writes_;
1275 // Used to store the relocs data computed by the Read_relocs pass.
1276 // Used during garbage collection of unused sections.
1277 Read_relocs_data* rd_;
1278 // Used to store the symbols data computed by the Read_symbols pass.
1279 // Again used during garbage collection when laying out referenced
1281 gold::Symbols_data* sd_;
1282 // Per-symbol counts of relocations, for incremental links.
1283 unsigned int* reloc_counts_;
1284 // Per-symbol base indexes of relocations, for incremental links.
1285 unsigned int* reloc_bases_;
1286 // Index of the first dynamic relocation for this object.
1287 unsigned int first_dyn_reloc_;
1288 // Count of dynamic relocations for this object.
1289 unsigned int dyn_reloc_count_;
1292 // This class is used to handle relocations against a section symbol
1293 // in an SHF_MERGE section. For such a symbol, we need to know the
1294 // addend of the relocation before we can determine the final value.
1295 // The addend gives us the location in the input section, and we can
1296 // determine how it is mapped to the output section. For a
1297 // non-section symbol, we apply the addend to the final value of the
1298 // symbol; that is done in finalize_local_symbols, and does not use
1302 class Merged_symbol_value
1305 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value;
1307 // We use a hash table to map offsets in the input section to output
1309 typedef Unordered_map<section_offset_type, Value> Output_addresses;
1311 Merged_symbol_value(Value input_value, Value output_start_address)
1312 : input_value_(input_value), output_start_address_(output_start_address),
1316 // Initialize the hash table.
1318 initialize_input_to_output_map(const Relobj*, unsigned int input_shndx);
1320 // Release the hash table to save space.
1322 free_input_to_output_map()
1323 { this->output_addresses_.clear(); }
1325 // Get the output value corresponding to an addend. The object and
1326 // input section index are passed in because the caller will have
1327 // them; otherwise we could store them here.
1329 value(const Relobj* object, unsigned int input_shndx, Value addend) const
1331 // This is a relocation against a section symbol. ADDEND is the
1332 // offset in the section. The result should be the start of some
1333 // merge area. If the object file wants something else, it should
1334 // use a regular symbol rather than a section symbol.
1335 // Unfortunately, PR 6658 shows a case in which the object file
1336 // refers to the section symbol, but uses a negative ADDEND to
1337 // compensate for a PC relative reloc. We can't handle the
1338 // general case. However, we can handle the special case of a
1339 // negative addend, by assuming that it refers to the start of the
1340 // section. Of course, that means that we have to guess when
1341 // ADDEND is negative. It is normal to see a 32-bit value here
1342 // even when the template parameter size is 64, as 64-bit object
1343 // file formats have 32-bit relocations. We know this is a merge
1344 // section, so we know it has to fit into memory. So we assume
1345 // that we won't see a value larger than a large 32-bit unsigned
1346 // value. This will break objects with very very large merge
1347 // sections; they probably break in other ways anyhow.
1348 Value input_offset = this->input_value_;
1349 if (addend < 0xffffff00)
1351 input_offset += addend;
1354 typename Output_addresses::const_iterator p =
1355 this->output_addresses_.find(input_offset);
1356 if (p != this->output_addresses_.end())
1357 return p->second + addend;
1359 return (this->value_from_output_section(object, input_shndx, input_offset)
1364 // Get the output value for an input offset if we couldn't find it
1365 // in the hash table.
1367 value_from_output_section(const Relobj*, unsigned int input_shndx,
1368 Value input_offset) const;
1370 // The value of the section symbol in the input file. This is
1371 // normally zero, but could in principle be something else.
1373 // The start address of this merged section in the output file.
1374 Value output_start_address_;
1375 // A hash table which maps offsets in the input section to output
1376 // addresses. This only maps specific offsets, not all offsets.
1377 Output_addresses output_addresses_;
1380 // This POD class is holds the value of a symbol. This is used for
1381 // local symbols, and for all symbols during relocation processing.
1382 // For special sections, such as SHF_MERGE sections, this calls a
1383 // function to get the final symbol value.
1389 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value;
1392 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1393 is_ordinary_shndx_(false), is_section_symbol_(false),
1394 is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
1395 { this->u_.value = 0; }
1399 if (!this->has_output_value_)
1400 delete this->u_.merged_symbol_value;
1403 // Get the value of this symbol. OBJECT is the object in which this
1404 // symbol is defined, and ADDEND is an addend to add to the value.
1405 template<bool big_endian>
1407 value(const Sized_relobj_file<size, big_endian>* object, Value addend) const
1409 if (this->has_output_value_)
1410 return this->u_.value + addend;
1413 gold_assert(this->is_ordinary_shndx_);
1414 return this->u_.merged_symbol_value->value(object, this->input_shndx_,
1419 // Set the value of this symbol in the output symbol table.
1421 set_output_value(Value value)
1422 { this->u_.value = value; }
1424 // For a section symbol in a merged section, we need more
1427 set_merged_symbol_value(Merged_symbol_value<size>* msv)
1429 gold_assert(this->is_section_symbol_);
1430 this->has_output_value_ = false;
1431 this->u_.merged_symbol_value = msv;
1434 // Initialize the input to output map for a section symbol in a
1435 // merged section. We also initialize the value of a non-section
1436 // symbol in a merged section.
1438 initialize_input_to_output_map(const Relobj* object)
1440 if (!this->has_output_value_)
1442 gold_assert(this->is_section_symbol_ && this->is_ordinary_shndx_);
1443 Merged_symbol_value<size>* msv = this->u_.merged_symbol_value;
1444 msv->initialize_input_to_output_map(object, this->input_shndx_);
1448 // Free the input to output map for a section symbol in a merged
1451 free_input_to_output_map()
1453 if (!this->has_output_value_)
1454 this->u_.merged_symbol_value->free_input_to_output_map();
1457 // Set the value of the symbol from the input file. This is only
1458 // called by count_local_symbols, to communicate the value to
1459 // finalize_local_symbols.
1461 set_input_value(Value value)
1462 { this->u_.value = value; }
1464 // Return the input value. This is only called by
1465 // finalize_local_symbols and (in special cases) relocate_section.
1468 { return this->u_.value; }
1470 // Return whether we have set the index in the output symbol table
1473 is_output_symtab_index_set() const
1475 return (this->output_symtab_index_ != 0
1476 && this->output_symtab_index_ != -2U);
1479 // Return whether this symbol may be discarded from the normal
1482 may_be_discarded_from_output_symtab() const
1484 gold_assert(!this->is_output_symtab_index_set());
1485 return this->output_symtab_index_ != -2U;
1488 // Return whether this symbol has an entry in the output symbol
1491 has_output_symtab_entry() const
1493 gold_assert(this->is_output_symtab_index_set());
1494 return this->output_symtab_index_ != -1U;
1497 // Return the index in the output symbol table.
1499 output_symtab_index() const
1501 gold_assert(this->is_output_symtab_index_set()
1502 && this->output_symtab_index_ != -1U);
1503 return this->output_symtab_index_;
1506 // Set the index in the output symbol table.
1508 set_output_symtab_index(unsigned int i)
1510 gold_assert(!this->is_output_symtab_index_set());
1511 gold_assert(i != 0 && i != -1U && i != -2U);
1512 this->output_symtab_index_ = i;
1515 // Record that this symbol should not go into the output symbol
1518 set_no_output_symtab_entry()
1520 gold_assert(this->output_symtab_index_ == 0);
1521 this->output_symtab_index_ = -1U;
1524 // Record that this symbol must go into the output symbol table,
1525 // because it there is a relocation that uses it.
1527 set_must_have_output_symtab_entry()
1529 gold_assert(!this->is_output_symtab_index_set());
1530 this->output_symtab_index_ = -2U;
1533 // Set the index in the output dynamic symbol table.
1535 set_needs_output_dynsym_entry()
1537 gold_assert(!this->is_section_symbol());
1538 this->output_dynsym_index_ = 0;
1541 // Return whether this symbol should go into the dynamic symbol
1544 needs_output_dynsym_entry() const
1546 return this->output_dynsym_index_ != -1U;
1549 // Return whether this symbol has an entry in the dynamic symbol
1552 has_output_dynsym_entry() const
1554 gold_assert(this->output_dynsym_index_ != 0);
1555 return this->output_dynsym_index_ != -1U;
1558 // Record that this symbol should go into the dynamic symbol table.
1560 set_output_dynsym_index(unsigned int i)
1562 gold_assert(this->output_dynsym_index_ == 0);
1563 gold_assert(i != 0 && i != -1U);
1564 this->output_dynsym_index_ = i;
1567 // Return the index in the output dynamic symbol table.
1569 output_dynsym_index() const
1571 gold_assert(this->output_dynsym_index_ != 0
1572 && this->output_dynsym_index_ != -1U);
1573 return this->output_dynsym_index_;
1576 // Set the index of the input section in the input file.
1578 set_input_shndx(unsigned int i, bool is_ordinary)
1580 this->input_shndx_ = i;
1581 // input_shndx_ field is a bitfield, so make sure that the value
1583 gold_assert(this->input_shndx_ == i);
1584 this->is_ordinary_shndx_ = is_ordinary;
1587 // Return the index of the input section in the input file.
1589 input_shndx(bool* is_ordinary) const
1591 *is_ordinary = this->is_ordinary_shndx_;
1592 return this->input_shndx_;
1595 // Whether this is a section symbol.
1597 is_section_symbol() const
1598 { return this->is_section_symbol_; }
1600 // Record that this is a section symbol.
1602 set_is_section_symbol()
1604 gold_assert(!this->needs_output_dynsym_entry());
1605 this->is_section_symbol_ = true;
1608 // Record that this is a TLS symbol.
1611 { this->is_tls_symbol_ = true; }
1613 // Return true if this is a TLS symbol.
1615 is_tls_symbol() const
1616 { return this->is_tls_symbol_; }
1618 // Record that this is an IFUNC symbol.
1620 set_is_ifunc_symbol()
1621 { this->is_ifunc_symbol_ = true; }
1623 // Return true if this is an IFUNC symbol.
1625 is_ifunc_symbol() const
1626 { return this->is_ifunc_symbol_; }
1628 // Return true if this has output value.
1630 has_output_value() const
1631 { return this->has_output_value_; }
1634 // The index of this local symbol in the output symbol table. This
1635 // will be 0 if no value has been assigned yet, and the symbol may
1636 // be omitted. This will be -1U if the symbol should not go into
1637 // the symbol table. This will be -2U if the symbol must go into
1638 // the symbol table, but no index has been assigned yet.
1639 unsigned int output_symtab_index_;
1640 // The index of this local symbol in the dynamic symbol table. This
1641 // will be -1U if the symbol should not go into the symbol table.
1642 unsigned int output_dynsym_index_;
1643 // The section index in the input file in which this symbol is
1645 unsigned int input_shndx_ : 27;
1646 // Whether the section index is an ordinary index, not a special
1648 bool is_ordinary_shndx_ : 1;
1649 // Whether this is a STT_SECTION symbol.
1650 bool is_section_symbol_ : 1;
1651 // Whether this is a STT_TLS symbol.
1652 bool is_tls_symbol_ : 1;
1653 // Whether this is a STT_GNU_IFUNC symbol.
1654 bool is_ifunc_symbol_ : 1;
1655 // Whether this symbol has a value for the output file. This is
1656 // normally set to true during Layout::finalize, by
1657 // finalize_local_symbols. It will be false for a section symbol in
1658 // a merge section, as for such symbols we can not determine the
1659 // value to use in a relocation until we see the addend.
1660 bool has_output_value_ : 1;
1663 // This is used if has_output_value_ is true. Between
1664 // count_local_symbols and finalize_local_symbols, this is the
1665 // value in the input file. After finalize_local_symbols, it is
1666 // the value in the output file.
1668 // This is used if has_output_value_ is false. It points to the
1669 // information we need to get the value for a merge section.
1670 Merged_symbol_value<size>* merged_symbol_value;
1674 // This type is used to modify relocations for -fsplit-stack. It is
1675 // indexed by relocation index, and means that the relocation at that
1676 // index should use the symbol from the vector, rather than the one
1677 // indicated by the relocation.
1679 class Reloc_symbol_changes
1682 Reloc_symbol_changes(size_t count)
1687 set(size_t i, Symbol* sym)
1688 { this->vec_[i] = sym; }
1691 operator[](size_t i) const
1692 { return this->vec_[i]; }
1695 std::vector<Symbol*> vec_;
1698 // Type for mapping section index to uncompressed size.
1700 typedef std::map<unsigned int, section_size_type> Compressed_section_map;
1702 // Abstract base class for a regular object file, either a real object file
1703 // or an incremental (unchanged) object. This is size and endian specific.
1705 template<int size, bool big_endian>
1706 class Sized_relobj : public Relobj
1709 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
1710 typedef Relobj::Symbols Symbols;
1712 static const Address invalid_address = static_cast<Address>(0) - 1;
1714 Sized_relobj(const std::string& name, Input_file* input_file)
1715 : Relobj(name, input_file), local_got_offsets_(), section_offsets_()
1718 Sized_relobj(const std::string& name, Input_file* input_file,
1720 : Relobj(name, input_file, offset), local_got_offsets_(), section_offsets_()
1726 // If this is a regular object, return a pointer to the Sized_relobj_file
1727 // object. Otherwise, return NULL.
1728 virtual Sized_relobj_file<size, big_endian>*
1732 const virtual Sized_relobj_file<size, big_endian>*
1733 sized_relobj() const
1736 // Checks if the offset of input section SHNDX within its output
1737 // section is invalid.
1739 is_output_section_offset_invalid(unsigned int shndx) const
1740 { return this->get_output_section_offset(shndx) == invalid_address; }
1742 // Get the offset of input section SHNDX within its output section.
1743 // This is -1 if the input section requires a special mapping, such
1744 // as a merge section. The output section can be found in the
1745 // output_sections_ field of the parent class Relobj.
1747 get_output_section_offset(unsigned int shndx) const
1749 gold_assert(shndx < this->section_offsets_.size());
1750 return this->section_offsets_[shndx];
1753 // Return whether the local symbol SYMNDX has a GOT offset.
1754 // For TLS symbols, the GOT entry will hold its tp-relative offset.
1756 local_has_got_offset(unsigned int symndx, unsigned int got_type) const
1758 Local_got_offsets::const_iterator p =
1759 this->local_got_offsets_.find(symndx);
1760 return (p != this->local_got_offsets_.end()
1761 && p->second->get_offset(got_type) != -1U);
1764 // Return the GOT offset of the local symbol SYMNDX.
1766 local_got_offset(unsigned int symndx, unsigned int got_type) const
1768 Local_got_offsets::const_iterator p =
1769 this->local_got_offsets_.find(symndx);
1770 gold_assert(p != this->local_got_offsets_.end());
1771 unsigned int off = p->second->get_offset(got_type);
1772 gold_assert(off != -1U);
1776 // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
1778 set_local_got_offset(unsigned int symndx, unsigned int got_type,
1779 unsigned int got_offset)
1781 Local_got_offsets::const_iterator p =
1782 this->local_got_offsets_.find(symndx);
1783 if (p != this->local_got_offsets_.end())
1784 p->second->set_offset(got_type, got_offset);
1787 Got_offset_list* g = new Got_offset_list(got_type, got_offset);
1788 std::pair<Local_got_offsets::iterator, bool> ins =
1789 this->local_got_offsets_.insert(std::make_pair(symndx, g));
1790 gold_assert(ins.second);
1794 // Iterate over local symbols, calling a visitor class V for each GOT offset
1795 // associated with a local symbol.
1797 do_for_all_local_got_entries(Got_offset_list::Visitor* v) const;
1800 typedef Relobj::Output_sections Output_sections;
1802 // Clear the local symbol information.
1805 { this->local_got_offsets_.clear(); }
1807 // Return the vector of section offsets.
1808 std::vector<Address>&
1810 { return this->section_offsets_; }
1812 // Get the offset of a section.
1814 do_output_section_offset(unsigned int shndx) const
1816 Address off = this->get_output_section_offset(shndx);
1817 if (off == invalid_address)
1822 // Set the offset of a section.
1824 do_set_section_offset(unsigned int shndx, uint64_t off)
1826 gold_assert(shndx < this->section_offsets_.size());
1827 this->section_offsets_[shndx] =
1828 (off == static_cast<uint64_t>(-1)
1830 : convert_types<Address, uint64_t>(off));
1834 // The GOT offsets of local symbols. This map also stores GOT offsets
1835 // for tp-relative offsets for TLS symbols.
1836 typedef Unordered_map<unsigned int, Got_offset_list*> Local_got_offsets;
1838 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1839 // for TLS symbols, indexed by symbol number.
1840 Local_got_offsets local_got_offsets_;
1841 // For each input section, the offset of the input section in its
1842 // output section. This is INVALID_ADDRESS if the input section requires a
1844 std::vector<Address> section_offsets_;
1847 // A regular object file. This is size and endian specific.
1849 template<int size, bool big_endian>
1850 class Sized_relobj_file : public Sized_relobj<size, big_endian>
1853 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
1854 typedef typename Sized_relobj<size, big_endian>::Symbols Symbols;
1855 typedef std::vector<Symbol_value<size> > Local_values;
1857 static const Address invalid_address = static_cast<Address>(0) - 1;
1859 enum Compute_final_local_value_status
1863 // An error occurred.
1865 // The local symbol has no output section.
1869 Sized_relobj_file(const std::string& name,
1870 Input_file* input_file,
1872 const typename elfcpp::Ehdr<size, big_endian>&);
1874 ~Sized_relobj_file();
1876 // Set up the object file based on TARGET.
1879 { this->do_setup(); }
1881 // Return a pointer to the Sized_relobj_file object.
1882 Sized_relobj_file<size, big_endian>*
1886 const Sized_relobj_file<size, big_endian>*
1887 sized_relobj() const
1890 // Return the number of symbols. This is only valid after
1891 // Object::add_symbols has been called.
1893 symbol_count() const
1894 { return this->local_symbol_count_ + this->symbols_.size(); }
1896 // If SYM is the index of a global symbol in the object file's
1897 // symbol table, return the Symbol object. Otherwise, return NULL.
1899 global_symbol(unsigned int sym) const
1901 if (sym >= this->local_symbol_count_)
1903 gold_assert(sym - this->local_symbol_count_ < this->symbols_.size());
1904 return this->symbols_[sym - this->local_symbol_count_];
1909 // Return the section index of symbol SYM. Set *VALUE to its value
1910 // in the object file. Set *IS_ORDINARY if this is an ordinary
1911 // section index, not a special code between SHN_LORESERVE and
1912 // SHN_HIRESERVE. Note that for a symbol which is not defined in
1913 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
1914 // it will not return the final value of the symbol in the link.
1916 symbol_section_and_value(unsigned int sym, Address* value, bool* is_ordinary);
1918 // Return a pointer to the Symbol_value structure which holds the
1919 // value of a local symbol.
1920 const Symbol_value<size>*
1921 local_symbol(unsigned int sym) const
1923 gold_assert(sym < this->local_values_.size());
1924 return &this->local_values_[sym];
1927 // Return the index of local symbol SYM in the ordinary symbol
1928 // table. A value of -1U means that the symbol is not being output.
1930 symtab_index(unsigned int sym) const
1932 gold_assert(sym < this->local_values_.size());
1933 return this->local_values_[sym].output_symtab_index();
1936 // Return the index of local symbol SYM in the dynamic symbol
1937 // table. A value of -1U means that the symbol is not being output.
1939 dynsym_index(unsigned int sym) const
1941 gold_assert(sym < this->local_values_.size());
1942 return this->local_values_[sym].output_dynsym_index();
1945 // Return the input section index of local symbol SYM.
1947 local_symbol_input_shndx(unsigned int sym, bool* is_ordinary) const
1949 gold_assert(sym < this->local_values_.size());
1950 return this->local_values_[sym].input_shndx(is_ordinary);
1953 // Record that local symbol SYM must be in the output symbol table.
1955 set_must_have_output_symtab_entry(unsigned int sym)
1957 gold_assert(sym < this->local_values_.size());
1958 this->local_values_[sym].set_must_have_output_symtab_entry();
1961 // Record that local symbol SYM needs a dynamic symbol entry.
1963 set_needs_output_dynsym_entry(unsigned int sym)
1965 gold_assert(sym < this->local_values_.size());
1966 this->local_values_[sym].set_needs_output_dynsym_entry();
1969 // Return whether the local symbol SYMNDX has a PLT offset.
1971 local_has_plt_offset(unsigned int symndx) const;
1973 // Return the PLT offset for a local symbol. It is an error to call
1974 // this if it doesn't have one.
1976 local_plt_offset(unsigned int symndx) const;
1978 // Set the PLT offset of the local symbol SYMNDX.
1980 set_local_plt_offset(unsigned int symndx, unsigned int plt_offset);
1982 // Return the name of the symbol that spans the given offset in the
1983 // specified section in this object. This is used only for error
1984 // messages and is not particularly efficient.
1986 get_symbol_location_info(unsigned int shndx, off_t offset,
1987 Symbol_location_info* info);
1989 // Look for a kept section corresponding to the given discarded section,
1990 // and return its output address. This is used only for relocations in
1991 // debugging sections.
1993 map_to_kept_section(unsigned int shndx, bool* found) const;
1995 // Compute final local symbol value. R_SYM is the local symbol index.
1996 // LV_IN points to a local symbol value containing the input value.
1997 // LV_OUT points to a local symbol value storing the final output value,
1998 // which must not be a merged symbol value since before calling this
1999 // method to avoid memory leak. SYMTAB points to a symbol table.
2001 // The method returns a status code at return. If the return status is
2002 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2003 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2004 // *LV_OUT is not modified.
2005 Compute_final_local_value_status
2006 compute_final_local_value(unsigned int r_sym,
2007 const Symbol_value<size>* lv_in,
2008 Symbol_value<size>* lv_out,
2009 const Symbol_table* symtab);
2012 typedef typename Sized_relobj<size, big_endian>::Output_sections
2019 // Read the symbols.
2021 do_read_symbols(Read_symbols_data*);
2023 // Return the number of local symbols.
2025 do_local_symbol_count() const
2026 { return this->local_symbol_count_; }
2028 // Return the number of local symbols in the output symbol table.
2030 do_output_local_symbol_count() const
2031 { return this->output_local_symbol_count_; }
2033 // Return the number of local symbols in the output symbol table.
2035 do_local_symbol_offset() const
2036 { return this->local_symbol_offset_; }
2038 // Lay out the input sections.
2040 do_layout(Symbol_table*, Layout*, Read_symbols_data*);
2042 // Layout sections whose layout was deferred while waiting for
2043 // input files from a plugin.
2045 do_layout_deferred_sections(Layout*);
2047 // Add the symbols to the symbol table.
2049 do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
2051 Archive::Should_include
2052 do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
2055 // Iterate over global symbols, calling a visitor class V for each.
2057 do_for_all_global_symbols(Read_symbols_data* sd,
2058 Library_base::Symbol_visitor_base* v);
2062 do_read_relocs(Read_relocs_data*);
2064 // Process the relocs to find list of referenced sections. Used only
2065 // during garbage collection.
2067 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
2069 // Scan the relocs and adjust the symbol table.
2071 do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*);
2073 // Count the local symbols.
2075 do_count_local_symbols(Stringpool_template<char>*,
2076 Stringpool_template<char>*);
2078 // Finalize the local symbols.
2080 do_finalize_local_symbols(unsigned int, off_t, Symbol_table*);
2082 // Set the offset where local dynamic symbol information will be stored.
2084 do_set_local_dynsym_indexes(unsigned int);
2086 // Set the offset where local dynamic symbol information will be stored.
2088 do_set_local_dynsym_offset(off_t);
2090 // Relocate the input sections and write out the local symbols.
2092 do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of);
2094 // Get the size of a section.
2096 do_section_size(unsigned int shndx)
2097 { return this->elf_file_.section_size(shndx); }
2099 // Get the name of a section.
2101 do_section_name(unsigned int shndx)
2102 { return this->elf_file_.section_name(shndx); }
2104 // Return the location of the contents of a section.
2106 do_section_contents(unsigned int shndx)
2107 { return this->elf_file_.section_contents(shndx); }
2109 // Return section flags.
2111 do_section_flags(unsigned int shndx);
2113 // Return section entsize.
2115 do_section_entsize(unsigned int shndx);
2117 // Return section address.
2119 do_section_address(unsigned int shndx)
2120 { return this->elf_file_.section_addr(shndx); }
2122 // Return section type.
2124 do_section_type(unsigned int shndx)
2125 { return this->elf_file_.section_type(shndx); }
2127 // Return the section link field.
2129 do_section_link(unsigned int shndx)
2130 { return this->elf_file_.section_link(shndx); }
2132 // Return the section info field.
2134 do_section_info(unsigned int shndx)
2135 { return this->elf_file_.section_info(shndx); }
2137 // Return the section alignment.
2139 do_section_addralign(unsigned int shndx)
2140 { return this->elf_file_.section_addralign(shndx); }
2142 // Return the Xindex structure to use.
2144 do_initialize_xindex();
2146 // Get symbol counts.
2148 do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
2150 // Get the global symbols.
2152 do_get_global_symbols() const
2153 { return &this->symbols_; }
2155 // Adjust a section index if necessary.
2157 adjust_shndx(unsigned int shndx)
2159 if (shndx >= elfcpp::SHN_LORESERVE)
2160 shndx += this->elf_file_.large_shndx_offset();
2164 // Initialize input to output maps for section symbols in merged
2167 initialize_input_to_output_maps();
2169 // Free the input to output maps for section symbols in merged
2172 free_input_to_output_maps();
2174 // Return symbol table section index.
2176 symtab_shndx() const
2177 { return this->symtab_shndx_; }
2179 // Allow a child class to access the ELF file.
2180 elfcpp::Elf_file<size, big_endian, Object>*
2182 { return &this->elf_file_; }
2184 // Allow a child class to access the local values.
2187 { return &this->local_values_; }
2189 // Views and sizes when relocating.
2192 unsigned char* view;
2193 typename elfcpp::Elf_types<size>::Elf_Addr address;
2195 section_size_type view_size;
2196 bool is_input_output_view;
2197 bool is_postprocessing_view;
2200 typedef std::vector<View_size> Views;
2202 // This may be overriden by a child class.
2204 do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
2205 const unsigned char* pshdrs, Output_file* of,
2208 // Allow a child to set output local symbol count.
2210 set_output_local_symbol_count(unsigned int value)
2211 { this->output_local_symbol_count_ = value; }
2213 // Return TRUE if the section is a compressed debug section, and set
2214 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
2216 do_section_is_compressed(unsigned int shndx,
2217 section_size_type* uncompressed_size) const
2219 if (this->compressed_sections_ == NULL)
2221 Compressed_section_map::const_iterator p =
2222 this->compressed_sections_->find(shndx);
2223 if (p != this->compressed_sections_->end())
2225 if (uncompressed_size != NULL)
2226 *uncompressed_size = p->second;
2234 typedef Sized_relobj_file<size, big_endian> This;
2235 static const int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
2236 static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
2237 static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2238 typedef elfcpp::Shdr<size, big_endian> Shdr;
2240 // To keep track of discarded comdat sections, we need to map a member
2241 // section index to the object and section index of the corresponding
2243 struct Kept_comdat_section
2245 Kept_comdat_section(Relobj* a_object, unsigned int a_shndx)
2246 : object(a_object), shndx(a_shndx)
2251 typedef std::map<unsigned int, Kept_comdat_section>
2252 Kept_comdat_section_table;
2254 // Find the SHT_SYMTAB section, given the section headers.
2256 find_symtab(const unsigned char* pshdrs);
2258 // Return whether SHDR has the right flags for a GNU style exception
2261 check_eh_frame_flags(const elfcpp::Shdr<size, big_endian>* shdr) const;
2263 // Return whether there is a section named .eh_frame which might be
2264 // a GNU style exception frame section.
2266 find_eh_frame(const unsigned char* pshdrs, const char* names,
2267 section_size_type names_size) const;
2269 // Whether to include a section group in the link.
2271 include_section_group(Symbol_table*, Layout*, unsigned int, const char*,
2272 const unsigned char*, const char*, section_size_type,
2273 std::vector<bool>*);
2275 // Whether to include a linkonce section in the link.
2277 include_linkonce_section(Layout*, unsigned int, const char*,
2278 const elfcpp::Shdr<size, big_endian>&);
2280 // Layout an input section.
2282 layout_section(Layout* layout, unsigned int shndx, const char* name,
2283 typename This::Shdr& shdr, unsigned int reloc_shndx,
2284 unsigned int reloc_type);
2286 // Write section data to the output file. Record the views and
2287 // sizes in VIEWS for use when relocating.
2289 write_sections(const unsigned char* pshdrs, Output_file*, Views*);
2291 // Relocate the sections in the output file.
2293 relocate_sections(const Symbol_table* symtab, const Layout* layout,
2294 const unsigned char* pshdrs, Output_file* of,
2296 { this->do_relocate_sections(symtab, layout, pshdrs, of, pviews); }
2298 // Scan the input relocations for --emit-relocs.
2300 emit_relocs_scan(Symbol_table*, Layout*, const unsigned char* plocal_syms,
2301 const Read_relocs_data::Relocs_list::iterator&);
2303 // Scan the input relocations for --emit-relocs, templatized on the
2304 // type of the relocation section.
2305 template<int sh_type>
2307 emit_relocs_scan_reltype(Symbol_table*, Layout*,
2308 const unsigned char* plocal_syms,
2309 const Read_relocs_data::Relocs_list::iterator&,
2310 Relocatable_relocs*);
2312 // Emit the relocs for --emit-relocs.
2314 emit_relocs(const Relocate_info<size, big_endian>*, unsigned int,
2315 unsigned int sh_type, const unsigned char* prelocs,
2316 size_t reloc_count, Output_section*, Address output_offset,
2317 unsigned char* view, Address address,
2318 section_size_type view_size,
2319 unsigned char* reloc_view, section_size_type reloc_view_size);
2321 // Emit the relocs for --emit-relocs, templatized on the type of the
2322 // relocation section.
2323 template<int sh_type>
2325 emit_relocs_reltype(const Relocate_info<size, big_endian>*, unsigned int,
2326 const unsigned char* prelocs, size_t reloc_count,
2327 Output_section*, Address output_offset,
2328 unsigned char* view, Address address,
2329 section_size_type view_size,
2330 unsigned char* reloc_view,
2331 section_size_type reloc_view_size);
2333 // Scan the input relocations for --incremental.
2335 incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator&);
2337 // Scan the input relocations for --incremental, templatized on the
2338 // type of the relocation section.
2339 template<int sh_type>
2341 incremental_relocs_scan_reltype(
2342 const Read_relocs_data::Relocs_list::iterator&);
2345 incremental_relocs_write(const Relocate_info<size, big_endian>*,
2346 unsigned int sh_type,
2347 const unsigned char* prelocs,
2350 Address output_offset,
2353 template<int sh_type>
2355 incremental_relocs_write_reltype(const Relocate_info<size, big_endian>*,
2356 const unsigned char* prelocs,
2359 Address output_offset,
2362 // A type shared by split_stack_adjust_reltype and find_functions.
2363 typedef std::map<section_offset_type, section_size_type> Function_offsets;
2365 // Check for -fsplit-stack routines calling non-split-stack routines.
2367 split_stack_adjust(const Symbol_table*, const unsigned char* pshdrs,
2368 unsigned int sh_type, unsigned int shndx,
2369 const unsigned char* prelocs, size_t reloc_count,
2370 unsigned char* view, section_size_type view_size,
2371 Reloc_symbol_changes** reloc_map);
2373 template<int sh_type>
2375 split_stack_adjust_reltype(const Symbol_table*, const unsigned char* pshdrs,
2376 unsigned int shndx, const unsigned char* prelocs,
2377 size_t reloc_count, unsigned char* view,
2378 section_size_type view_size,
2379 Reloc_symbol_changes** reloc_map);
2381 // Find all functions in a section.
2383 find_functions(const unsigned char* pshdrs, unsigned int shndx,
2386 // Write out the local symbols.
2388 write_local_symbols(Output_file*,
2389 const Stringpool_template<char>*,
2390 const Stringpool_template<char>*,
2391 Output_symtab_xindex*,
2392 Output_symtab_xindex*,
2395 // Record a mapping from discarded section SHNDX to the corresponding
2398 set_kept_comdat_section(unsigned int shndx, Relobj* kept_object,
2399 unsigned int kept_shndx)
2401 Kept_comdat_section kept(kept_object, kept_shndx);
2402 this->kept_comdat_sections_.insert(std::make_pair(shndx, kept));
2405 // Find the kept section corresponding to the discarded section
2406 // SHNDX. Return true if found.
2408 get_kept_comdat_section(unsigned int shndx, Relobj** kept_object,
2409 unsigned int* kept_shndx) const
2411 typename Kept_comdat_section_table::const_iterator p =
2412 this->kept_comdat_sections_.find(shndx);
2413 if (p == this->kept_comdat_sections_.end())
2415 *kept_object = p->second.object;
2416 *kept_shndx = p->second.shndx;
2420 // Compute final local symbol value. R_SYM is the local symbol index.
2421 // LV_IN points to a local symbol value containing the input value.
2422 // LV_OUT points to a local symbol value storing the final output value,
2423 // which must not be a merged symbol value since before calling this
2424 // method to avoid memory leak. RELOCATABLE indicates whether we are
2425 // linking a relocatable output. OUT_SECTIONS is an array of output
2426 // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
2427 // points to a symbol table.
2429 // The method returns a status code at return. If the return status is
2430 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2431 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2432 // *LV_OUT is not modified.
2433 inline Compute_final_local_value_status
2434 compute_final_local_value_internal(unsigned int r_sym,
2435 const Symbol_value<size>* lv_in,
2436 Symbol_value<size>* lv_out,
2438 const Output_sections& out_sections,
2439 const std::vector<Address>& out_offsets,
2440 const Symbol_table* symtab);
2442 // The PLT offsets of local symbols.
2443 typedef Unordered_map<unsigned int, unsigned int> Local_plt_offsets;
2445 // Saved information for sections whose layout was deferred.
2446 struct Deferred_layout
2448 static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
2449 Deferred_layout(unsigned int shndx, const char* name,
2450 const unsigned char* pshdr,
2451 unsigned int reloc_shndx, unsigned int reloc_type)
2452 : shndx_(shndx), name_(name), reloc_shndx_(reloc_shndx),
2453 reloc_type_(reloc_type)
2455 memcpy(this->shdr_data_, pshdr, shdr_size);
2457 unsigned int shndx_;
2459 unsigned int reloc_shndx_;
2460 unsigned int reloc_type_;
2461 unsigned char shdr_data_[shdr_size];
2464 // General access to the ELF file.
2465 elfcpp::Elf_file<size, big_endian, Object> elf_file_;
2466 // Index of SHT_SYMTAB section.
2467 unsigned int symtab_shndx_;
2468 // The number of local symbols.
2469 unsigned int local_symbol_count_;
2470 // The number of local symbols which go into the output file.
2471 unsigned int output_local_symbol_count_;
2472 // The number of local symbols which go into the output file's dynamic
2474 unsigned int output_local_dynsym_count_;
2475 // The entries in the symbol table for the external symbols.
2477 // Number of symbols defined in object file itself.
2478 size_t defined_count_;
2479 // File offset for local symbols (relative to start of symbol table).
2480 off_t local_symbol_offset_;
2481 // File offset for local dynamic symbols (absolute).
2482 off_t local_dynsym_offset_;
2483 // Values of local symbols.
2484 Local_values local_values_;
2485 // PLT offsets for local symbols.
2486 Local_plt_offsets local_plt_offsets_;
2487 // Table mapping discarded comdat sections to corresponding kept sections.
2488 Kept_comdat_section_table kept_comdat_sections_;
2489 // Whether this object has a GNU style .eh_frame section.
2491 // If this object has a GNU style .eh_frame section that is discarded in
2492 // output, record the index here. Otherwise it is -1U.
2493 unsigned int discarded_eh_frame_shndx_;
2494 // The list of sections whose layout was deferred.
2495 std::vector<Deferred_layout> deferred_layout_;
2496 // The list of relocation sections whose layout was deferred.
2497 std::vector<Deferred_layout> deferred_layout_relocs_;
2498 // For compressed debug sections, map section index to uncompressed size.
2499 Compressed_section_map* compressed_sections_;
2502 // A class to manage the list of all objects.
2508 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL)
2511 // The type of the list of input relocateable objects.
2512 typedef std::vector<Relobj*> Relobj_list;
2513 typedef Relobj_list::const_iterator Relobj_iterator;
2515 // The type of the list of input dynamic objects.
2516 typedef std::vector<Dynobj*> Dynobj_list;
2517 typedef Dynobj_list::const_iterator Dynobj_iterator;
2519 // Add an object to the list. Return true if all is well, or false
2520 // if this object should be ignored.
2522 add_object(Object*);
2524 // Start processing an archive.
2526 archive_start(Archive*);
2528 // Stop processing an archive.
2530 archive_stop(Archive*);
2532 // For each dynamic object, check whether we've seen all of its
2533 // explicit dependencies.
2535 check_dynamic_dependencies() const;
2537 // Return whether an object was found in the system library
2540 found_in_system_library_directory(const Object*) const;
2542 // Print symbol counts.
2544 print_symbol_counts(const Symbol_table*) const;
2546 // Print a cross reference table.
2548 print_cref(const Symbol_table*, FILE*) const;
2550 // Iterate over all regular objects.
2553 relobj_begin() const
2554 { return this->relobj_list_.begin(); }
2558 { return this->relobj_list_.end(); }
2560 // Iterate over all dynamic objects.
2563 dynobj_begin() const
2564 { return this->dynobj_list_.begin(); }
2568 { return this->dynobj_list_.end(); }
2570 // Return whether we have seen any dynamic objects.
2573 { return !this->dynobj_list_.empty(); }
2575 // Return the number of non dynamic objects.
2577 number_of_relobjs() const
2578 { return this->relobj_list_.size(); }
2580 // Return the number of input objects.
2582 number_of_input_objects() const
2583 { return this->relobj_list_.size() + this->dynobj_list_.size(); }
2586 Input_objects(const Input_objects&);
2587 Input_objects& operator=(const Input_objects&);
2589 // The list of ordinary objects included in the link.
2590 Relobj_list relobj_list_;
2591 // The list of dynamic objects included in the link.
2592 Dynobj_list dynobj_list_;
2593 // SONAMEs that we have seen.
2594 Unordered_set<std::string> sonames_;
2595 // Manage cross-references if requested.
2599 // Some of the information we pass to the relocation routines. We
2600 // group this together to avoid passing a dozen different arguments.
2602 template<int size, bool big_endian>
2603 struct Relocate_info
2606 const Symbol_table* symtab;
2608 const Layout* layout;
2609 // Object being relocated.
2610 Sized_relobj_file<size, big_endian>* object;
2611 // Section index of relocation section.
2612 unsigned int reloc_shndx;
2613 // Section header of relocation section.
2614 const unsigned char* reloc_shdr;
2615 // Section index of section being relocated.
2616 unsigned int data_shndx;
2617 // Section header of data section.
2618 const unsigned char* data_shdr;
2620 // Return a string showing the location of a relocation. This is
2621 // only used for error messages.
2623 location(size_t relnum, off_t reloffset) const;
2626 // This is used to represent a section in an object and is used as the
2627 // key type for various section maps.
2628 typedef std::pair<Object*, unsigned int> Section_id;
2630 // This is similar to Section_id but is used when the section
2631 // pointers are const.
2632 typedef std::pair<const Object*, unsigned int> Const_section_id;
2634 // The hash value is based on the address of an object in memory during
2635 // linking. It is okay to use this for looking up sections but never use
2636 // this in an unordered container that we want to traverse in a repeatable
2639 struct Section_id_hash
2641 size_t operator()(const Section_id& loc) const
2642 { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
2645 struct Const_section_id_hash
2647 size_t operator()(const Const_section_id& loc) const
2648 { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
2651 // Return whether INPUT_FILE contains an ELF object start at file
2652 // offset OFFSET. This sets *START to point to a view of the start of
2653 // the file. It sets *READ_SIZE to the number of bytes in the view.
2656 is_elf_object(Input_file* input_file, off_t offset,
2657 const unsigned char** start, int* read_size);
2659 // Return an Object appropriate for the input file. P is BYTES long,
2660 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2661 // this sees an object the linker is not configured to support, it
2662 // sets *PUNCONFIGURED to true and returns NULL without giving an
2666 make_elf_object(const std::string& name, Input_file*,
2667 off_t offset, const unsigned char* p,
2668 section_offset_type bytes, bool* punconfigured);
2670 } // end namespace gold
2672 #endif // !defined(GOLD_OBJECT_H)