1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright (C) 2006-2015 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
30 #include "elfcpp_file.h"
38 class General_options;
44 class Output_section_data;
46 class Output_symtab_xindex;
49 class Object_merge_map;
50 class Relocatable_relocs;
53 template<typename Stringpool_char>
54 class Stringpool_template;
56 // Data to pass from read_symbols() to add_symbols().
58 struct Read_symbols_data
61 : section_headers(NULL), section_names(NULL), symbols(NULL),
62 symbol_names(NULL), versym(NULL), verdef(NULL), verneed(NULL)
68 File_view* section_headers;
70 File_view* section_names;
71 // Size of section name data in bytes.
72 section_size_type section_names_size;
75 // Size of symbol data in bytes.
76 section_size_type symbols_size;
77 // Offset of external symbols within symbol data. This structure
78 // sometimes contains only external symbols, in which case this will
79 // be zero. Sometimes it contains all symbols.
80 section_offset_type external_symbols_offset;
82 File_view* symbol_names;
83 // Size of symbol name data in bytes.
84 section_size_type symbol_names_size;
86 // Version information. This is only used on dynamic objects.
87 // Version symbol data (from SHT_GNU_versym section).
89 section_size_type versym_size;
90 // Version definition data (from SHT_GNU_verdef section).
92 section_size_type verdef_size;
93 unsigned int verdef_info;
94 // Needed version data (from SHT_GNU_verneed section).
96 section_size_type verneed_size;
97 unsigned int verneed_info;
100 // Information used to print error messages.
102 struct Symbol_location_info
104 std::string source_file;
105 std::string enclosing_symbol_name;
106 elfcpp::STT enclosing_symbol_type;
109 // Data about a single relocation section. This is read in
110 // read_relocs and processed in scan_relocs.
112 struct Section_relocs
119 { delete this->contents; }
121 // Index of reloc section.
122 unsigned int reloc_shndx;
123 // Index of section that relocs apply to.
124 unsigned int data_shndx;
125 // Contents of reloc section.
127 // Reloc section type.
128 unsigned int sh_type;
129 // Number of reloc entries.
132 Output_section* output_section;
133 // Whether this section has special handling for offsets.
134 bool needs_special_offset_handling;
135 // Whether the data section is allocated (has the SHF_ALLOC flag set).
136 bool is_data_section_allocated;
139 // Relocations in an object file. This is read in read_relocs and
140 // processed in scan_relocs.
142 struct Read_relocs_data
145 : local_symbols(NULL)
149 { delete this->local_symbols; }
151 typedef std::vector<Section_relocs> Relocs_list;
154 // The local symbols.
155 File_view* local_symbols;
158 // The Xindex class manages section indexes for objects with more than
164 Xindex(int large_shndx_offset)
165 : large_shndx_offset_(large_shndx_offset), symtab_xindex_()
168 // Initialize the symtab_xindex_ array, given the object and the
169 // section index of the symbol table to use.
170 template<int size, bool big_endian>
172 initialize_symtab_xindex(Object*, unsigned int symtab_shndx);
174 // Read in the symtab_xindex_ array, given its section index.
175 // PSHDRS may optionally point to the section headers.
176 template<int size, bool big_endian>
178 read_symtab_xindex(Object*, unsigned int xindex_shndx,
179 const unsigned char* pshdrs);
181 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
182 // real section index.
184 sym_xindex_to_shndx(Object* object, unsigned int symndx);
187 // The type of the array giving the real section index for symbols
188 // whose st_shndx field holds SHN_XINDEX.
189 typedef std::vector<unsigned int> Symtab_xindex;
191 // Adjust a section index if necessary. This should only be called
192 // for ordinary section indexes.
194 adjust_shndx(unsigned int shndx)
196 if (shndx >= elfcpp::SHN_LORESERVE)
197 shndx += this->large_shndx_offset_;
201 // Adjust to apply to large section indexes.
202 int large_shndx_offset_;
203 // The data from the SHT_SYMTAB_SHNDX section.
204 Symtab_xindex symtab_xindex_;
207 // A GOT offset list. A symbol may have more than one GOT offset
208 // (e.g., when mixing modules compiled with two different TLS models),
209 // but will usually have at most one. GOT_TYPE identifies the type of
210 // GOT entry; its values are specific to each target.
212 class Got_offset_list
216 : got_type_(-1U), got_offset_(0), got_next_(NULL)
219 Got_offset_list(unsigned int got_type, unsigned int got_offset)
220 : got_type_(got_type), got_offset_(got_offset), got_next_(NULL)
225 if (this->got_next_ != NULL)
227 delete this->got_next_;
228 this->got_next_ = NULL;
232 // Initialize the fields to their default values.
236 this->got_type_ = -1U;
237 this->got_offset_ = 0;
238 this->got_next_ = NULL;
241 // Set the offset for the GOT entry of type GOT_TYPE.
243 set_offset(unsigned int got_type, unsigned int got_offset)
245 if (this->got_type_ == -1U)
247 this->got_type_ = got_type;
248 this->got_offset_ = got_offset;
252 for (Got_offset_list* g = this; g != NULL; g = g->got_next_)
254 if (g->got_type_ == got_type)
256 g->got_offset_ = got_offset;
260 Got_offset_list* g = new Got_offset_list(got_type, got_offset);
261 g->got_next_ = this->got_next_;
266 // Return the offset for a GOT entry of type GOT_TYPE.
268 get_offset(unsigned int got_type) const
270 for (const Got_offset_list* g = this; g != NULL; g = g->got_next_)
272 if (g->got_type_ == got_type)
273 return g->got_offset_;
278 // Return a pointer to the list, or NULL if the list is empty.
279 const Got_offset_list*
282 if (this->got_type_ == -1U)
287 // Abstract visitor class for iterating over GOT offsets.
299 visit(unsigned int, unsigned int) = 0;
302 // Loop over all GOT offset entries, calling a visitor class V for each.
304 for_all_got_offsets(Visitor* v) const
306 if (this->got_type_ == -1U)
308 for (const Got_offset_list* g = this; g != NULL; g = g->got_next_)
309 v->visit(g->got_type_, g->got_offset_);
313 unsigned int got_type_;
314 unsigned int got_offset_;
315 Got_offset_list* got_next_;
318 // Type for mapping section index to uncompressed size and contents.
320 struct Compressed_section_info
322 section_size_type size;
323 elfcpp::Elf_Xword flag;
324 const unsigned char* contents;
326 typedef std::map<unsigned int, Compressed_section_info> Compressed_section_map;
328 template<int size, bool big_endian>
329 Compressed_section_map*
330 build_compressed_section_map(const unsigned char* pshdrs, unsigned int shnum,
331 const char* names, section_size_type names_size,
332 Object* obj, bool decompress_if_needed);
334 // Object is an abstract base class which represents either a 32-bit
335 // or a 64-bit input object. This can be a regular object file
336 // (ET_REL) or a shared object (ET_DYN).
341 typedef std::vector<Symbol*> Symbols;
343 // NAME is the name of the object as we would report it to the user
344 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
345 // used to read the file. OFFSET is the offset within the input
346 // file--0 for a .o or .so file, something else for a .a file.
347 Object(const std::string& name, Input_file* input_file, bool is_dynamic,
349 : name_(name), input_file_(input_file), offset_(offset), shnum_(-1U),
350 is_dynamic_(is_dynamic), is_needed_(false), uses_split_stack_(false),
351 has_no_split_stack_(false), no_export_(false),
352 is_in_system_directory_(false), as_needed_(false), xindex_(NULL),
353 compressed_sections_(NULL)
355 if (input_file != NULL)
357 input_file->file().add_object();
358 this->is_in_system_directory_ = input_file->is_in_system_directory();
359 this->as_needed_ = input_file->options().as_needed();
365 if (this->input_file_ != NULL)
366 this->input_file_->file().remove_object();
369 // Return the name of the object as we would report it to the user.
372 { return this->name_; }
374 // Get the offset into the file.
377 { return this->offset_; }
379 // Return whether this is a dynamic object.
382 { return this->is_dynamic_; }
384 // Return the word size of the object file.
385 virtual int elfsize() const = 0;
387 // Return TRUE if this is a big-endian object file.
388 virtual bool is_big_endian() const = 0;
390 // Return whether this object is needed--true if it is a dynamic
391 // object which defines some symbol referenced by a regular object.
392 // We keep the flag here rather than in Dynobj for convenience when
396 { return this->is_needed_; }
398 // Record that this object is needed.
401 { this->is_needed_ = true; }
403 // Return whether this object was compiled with -fsplit-stack.
405 uses_split_stack() const
406 { return this->uses_split_stack_; }
408 // Return whether this object contains any functions compiled with
409 // the no_split_stack attribute.
411 has_no_split_stack() const
412 { return this->has_no_split_stack_; }
414 // Returns NULL for Objects that are not dynamic objects. This method
415 // is overridden in the Dynobj class.
418 { return this->do_dynobj(); }
420 // Returns NULL for Objects that are not plugin objects. This method
421 // is overridden in the Pluginobj class.
424 { return this->do_pluginobj(); }
426 // Get the file. We pass on const-ness.
430 gold_assert(this->input_file_ != NULL);
431 return this->input_file_;
437 gold_assert(this->input_file_ != NULL);
438 return this->input_file_;
441 // Lock the underlying file.
445 if (this->input_file_ != NULL)
446 this->input_file_->file().lock(t);
449 // Unlock the underlying file.
451 unlock(const Task* t)
453 if (this->input_file_ != NULL)
454 this->input_file()->file().unlock(t);
457 // Return whether the underlying file is locked.
460 { return this->input_file_ != NULL && this->input_file_->file().is_locked(); }
462 // Return the token, so that the task can be queued.
466 if (this->input_file_ == NULL)
468 return this->input_file()->file().token();
471 // Release the underlying file.
475 if (this->input_file_ != NULL)
476 this->input_file()->file().release();
479 // Return whether we should just read symbols from this file.
482 { return this->input_file()->just_symbols(); }
484 // Return whether this is an incremental object.
486 is_incremental() const
487 { return this->do_is_incremental(); }
489 // Return the last modified time of the file.
492 { return this->do_get_mtime(); }
494 // Get the number of sections.
497 { return this->shnum_; }
499 // Return a view of the contents of a section. Set *PLEN to the
500 // size. CACHE is a hint as in File_read::get_view.
502 section_contents(unsigned int shndx, section_size_type* plen, bool cache);
504 // Adjust a symbol's section index as needed. SYMNDX is the index
505 // of the symbol and SHNDX is the symbol's section from
506 // get_st_shndx. This returns the section index. It sets
507 // *IS_ORDINARY to indicate whether this is a normal section index,
508 // rather than a special code between SHN_LORESERVE and
511 adjust_sym_shndx(unsigned int symndx, unsigned int shndx, bool* is_ordinary)
513 if (shndx < elfcpp::SHN_LORESERVE)
515 else if (shndx == elfcpp::SHN_XINDEX)
517 if (this->xindex_ == NULL)
518 this->xindex_ = this->do_initialize_xindex();
519 shndx = this->xindex_->sym_xindex_to_shndx(this, symndx);
523 *is_ordinary = false;
527 // Return the size of a section given a section index.
529 section_size(unsigned int shndx)
530 { return this->do_section_size(shndx); }
532 // Return the name of a section given a section index.
534 section_name(unsigned int shndx) const
535 { return this->do_section_name(shndx); }
537 // Return the section flags given a section index.
539 section_flags(unsigned int shndx)
540 { return this->do_section_flags(shndx); }
542 // Return the section entsize given a section index.
544 section_entsize(unsigned int shndx)
545 { return this->do_section_entsize(shndx); }
547 // Return the section address given a section index.
549 section_address(unsigned int shndx)
550 { return this->do_section_address(shndx); }
552 // Return the section type given a section index.
554 section_type(unsigned int shndx)
555 { return this->do_section_type(shndx); }
557 // Return the section link field given a section index.
559 section_link(unsigned int shndx)
560 { return this->do_section_link(shndx); }
562 // Return the section info field given a section index.
564 section_info(unsigned int shndx)
565 { return this->do_section_info(shndx); }
567 // Return the required section alignment given a section index.
569 section_addralign(unsigned int shndx)
570 { return this->do_section_addralign(shndx); }
572 // Return the output section given a section index.
574 output_section(unsigned int shndx) const
575 { return this->do_output_section(shndx); }
577 // Given a section index, return its address.
578 // The return value will be -1U if the section is specially mapped,
579 // such as a merge section.
581 output_section_address(unsigned int shndx)
582 { return this->do_output_section_address(shndx); }
584 // Given a section index, return the offset in the Output_section.
585 // The return value will be -1U if the section is specially mapped,
586 // such as a merge section.
588 output_section_offset(unsigned int shndx) const
589 { return this->do_output_section_offset(shndx); }
591 // Read the symbol information.
593 read_symbols(Read_symbols_data* sd)
594 { return this->do_read_symbols(sd); }
596 // Pass sections which should be included in the link to the Layout
597 // object, and record where the sections go in the output file.
599 layout(Symbol_table* symtab, Layout* layout, Read_symbols_data* sd)
600 { this->do_layout(symtab, layout, sd); }
602 // Add symbol information to the global symbol table.
604 add_symbols(Symbol_table* symtab, Read_symbols_data* sd, Layout *layout)
605 { this->do_add_symbols(symtab, sd, layout); }
607 // Add symbol information to the global symbol table.
608 Archive::Should_include
609 should_include_member(Symbol_table* symtab, Layout* layout,
610 Read_symbols_data* sd, std::string* why)
611 { return this->do_should_include_member(symtab, layout, sd, why); }
613 // Iterate over global symbols, calling a visitor class V for each.
615 for_all_global_symbols(Read_symbols_data* sd,
616 Library_base::Symbol_visitor_base* v)
617 { return this->do_for_all_global_symbols(sd, v); }
619 // Iterate over local symbols, calling a visitor class V for each GOT offset
620 // associated with a local symbol.
622 for_all_local_got_entries(Got_offset_list::Visitor* v) const
623 { this->do_for_all_local_got_entries(v); }
625 // Functions and types for the elfcpp::Elf_file interface. This
626 // permit us to use Object as the File template parameter for
629 // The View class is returned by view. It must support a single
630 // method, data(). This is trivial, because get_view does what we
635 View(const unsigned char* p)
644 const unsigned char* p_;
649 view(off_t file_offset, section_size_type data_size)
650 { return View(this->get_view(file_offset, data_size, true, true)); }
654 error(const char* format, ...) const ATTRIBUTE_PRINTF_2;
656 // A location in the file.
662 Location(off_t fo, section_size_type ds)
663 : file_offset(fo), data_size(ds)
667 // Get a View given a Location.
668 View view(Location loc)
669 { return View(this->get_view(loc.file_offset, loc.data_size, true, true)); }
671 // Get a view into the underlying file.
673 get_view(off_t start, section_size_type size, bool aligned, bool cache)
675 return this->input_file()->file().get_view(this->offset_, start, size,
679 // Get a lasting view into the underlying file.
681 get_lasting_view(off_t start, section_size_type size, bool aligned,
684 return this->input_file()->file().get_lasting_view(this->offset_, start,
685 size, aligned, cache);
688 // Read data from the underlying file.
690 read(off_t start, section_size_type size, void* p)
691 { this->input_file()->file().read(start + this->offset_, size, p); }
693 // Read multiple data from the underlying file.
695 read_multiple(const File_read::Read_multiple& rm)
696 { this->input_file()->file().read_multiple(this->offset_, rm); }
698 // Stop caching views in the underlying file.
700 clear_view_cache_marks()
702 if (this->input_file_ != NULL)
703 this->input_file_->file().clear_view_cache_marks();
706 // Get the number of global symbols defined by this object, and the
707 // number of the symbols whose final definition came from this
710 get_global_symbol_counts(const Symbol_table* symtab, size_t* defined,
712 { this->do_get_global_symbol_counts(symtab, defined, used); }
714 // Get the symbols defined in this object.
716 get_global_symbols() const
717 { return this->do_get_global_symbols(); }
719 // Set flag that this object was found in a system directory.
721 set_is_in_system_directory()
722 { this->is_in_system_directory_ = true; }
724 // Return whether this object was found in a system directory.
726 is_in_system_directory() const
727 { return this->is_in_system_directory_; }
729 // Set flag that this object was linked with --as-needed.
732 { this->as_needed_ = true; }
734 // Return whether this object was linked with --as-needed.
737 { return this->as_needed_; }
739 // Return whether we found this object by searching a directory.
742 { return this->input_file()->will_search_for(); }
746 { return this->no_export_; }
749 set_no_export(bool value)
750 { this->no_export_ = value; }
753 section_is_compressed(unsigned int shndx,
754 section_size_type* uncompressed_size) const
756 if (this->compressed_sections_ == NULL)
758 Compressed_section_map::const_iterator p =
759 this->compressed_sections_->find(shndx);
760 if (p != this->compressed_sections_->end())
762 if (uncompressed_size != NULL)
763 *uncompressed_size = p->second.size;
769 // Return a view of the decompressed contents of a section. Set *PLEN
770 // to the size. Set *IS_NEW to true if the contents need to be freed
773 decompressed_section_contents(unsigned int shndx, section_size_type* plen,
776 // Discard any buffers of decompressed sections. This is done
777 // at the end of the Add_symbols task.
779 discard_decompressed_sections();
781 // Return the index of the first incremental relocation for symbol SYMNDX.
783 get_incremental_reloc_base(unsigned int symndx) const
784 { return this->do_get_incremental_reloc_base(symndx); }
786 // Return the number of incremental relocations for symbol SYMNDX.
788 get_incremental_reloc_count(unsigned int symndx) const
789 { return this->do_get_incremental_reloc_count(symndx); }
792 // Returns NULL for Objects that are not dynamic objects. This method
793 // is overridden in the Dynobj class.
798 // Returns NULL for Objects that are not plugin objects. This method
799 // is overridden in the Pluginobj class.
804 // Return TRUE if this is an incremental (unchanged) input file.
805 // We return FALSE by default; the incremental object classes
806 // override this method.
808 do_is_incremental() const
811 // Return the last modified time of the file. This method may be
812 // overridden for subclasses that don't use an actual file (e.g.,
813 // Incremental objects).
816 { return this->input_file()->file().get_mtime(); }
818 // Read the symbols--implemented by child class.
820 do_read_symbols(Read_symbols_data*) = 0;
822 // Lay out sections--implemented by child class.
824 do_layout(Symbol_table*, Layout*, Read_symbols_data*) = 0;
826 // Add symbol information to the global symbol table--implemented by
829 do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*) = 0;
831 virtual Archive::Should_include
832 do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
833 std::string* why) = 0;
835 // Iterate over global symbols, calling a visitor class V for each.
837 do_for_all_global_symbols(Read_symbols_data* sd,
838 Library_base::Symbol_visitor_base* v) = 0;
840 // Iterate over local symbols, calling a visitor class V for each GOT offset
841 // associated with a local symbol.
843 do_for_all_local_got_entries(Got_offset_list::Visitor* v) const = 0;
845 // Return the location of the contents of a section. Implemented by
847 virtual const unsigned char*
848 do_section_contents(unsigned int shndx, section_size_type* plen,
851 // Get the size of a section--implemented by child class.
853 do_section_size(unsigned int shndx) = 0;
855 // Get the name of a section--implemented by child class.
857 do_section_name(unsigned int shndx) const = 0;
859 // Get section flags--implemented by child class.
861 do_section_flags(unsigned int shndx) = 0;
863 // Get section entsize--implemented by child class.
865 do_section_entsize(unsigned int shndx) = 0;
867 // Get section address--implemented by child class.
869 do_section_address(unsigned int shndx) = 0;
871 // Get section type--implemented by child class.
873 do_section_type(unsigned int shndx) = 0;
875 // Get section link field--implemented by child class.
877 do_section_link(unsigned int shndx) = 0;
879 // Get section info field--implemented by child class.
881 do_section_info(unsigned int shndx) = 0;
883 // Get section alignment--implemented by child class.
885 do_section_addralign(unsigned int shndx) = 0;
887 // Return the output section given a section index--implemented
889 virtual Output_section*
890 do_output_section(unsigned int) const
891 { gold_unreachable(); }
893 // Get the address of a section--implemented by child class.
895 do_output_section_address(unsigned int)
896 { gold_unreachable(); }
898 // Get the offset of a section--implemented by child class.
900 do_output_section_offset(unsigned int) const
901 { gold_unreachable(); }
903 // Return the Xindex structure to use.
905 do_initialize_xindex() = 0;
907 // Implement get_global_symbol_counts--implemented by child class.
909 do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const = 0;
911 virtual const Symbols*
912 do_get_global_symbols() const = 0;
914 // Set the number of sections.
917 { this->shnum_ = shnum; }
919 // Functions used by both Sized_relobj_file and Sized_dynobj.
921 // Read the section data into a Read_symbols_data object.
922 template<int size, bool big_endian>
924 read_section_data(elfcpp::Elf_file<size, big_endian, Object>*,
927 // Find the section header with the given NAME. If HDR is non-NULL
928 // then it is a section header returned from a previous call to this
929 // function and the next section header with the same name will be
931 template<int size, bool big_endian>
933 find_shdr(const unsigned char* pshdrs, const char* name,
934 const char* names, section_size_type names_size,
935 const unsigned char* hdr) const;
937 // Let the child class initialize the xindex object directly.
939 set_xindex(Xindex* xindex)
941 gold_assert(this->xindex_ == NULL);
942 this->xindex_ = xindex;
945 // If NAME is the name of a special .gnu.warning section, arrange
946 // for the warning to be issued. SHNDX is the section index.
947 // Return whether it is a warning section.
949 handle_gnu_warning_section(const char* name, unsigned int shndx,
952 // If NAME is the name of the special section which indicates that
953 // this object was compiled with -fsplit-stack, mark it accordingly,
954 // and return true. Otherwise return false.
956 handle_split_stack_section(const char* name);
958 // Discard any buffers of decompressed sections. This is done
959 // at the end of the Add_symbols task.
961 do_discard_decompressed_sections()
964 // Return the index of the first incremental relocation for symbol SYMNDX--
965 // implemented by child class.
967 do_get_incremental_reloc_base(unsigned int) const
968 { gold_unreachable(); }
970 // Return the number of incremental relocations for symbol SYMNDX--
971 // implemented by child class.
973 do_get_incremental_reloc_count(unsigned int) const
974 { gold_unreachable(); }
977 set_compressed_sections(Compressed_section_map* compressed_sections)
978 { this->compressed_sections_ = compressed_sections; }
980 Compressed_section_map*
981 compressed_sections()
982 { return this->compressed_sections_; }
985 // This class may not be copied.
986 Object(const Object&);
987 Object& operator=(const Object&);
989 // Name of object as printed to user.
991 // For reading the file.
992 Input_file* input_file_;
993 // Offset within the file--0 for an object file, non-0 for an
996 // Number of input sections.
998 // Whether this is a dynamic object.
999 bool is_dynamic_ : 1;
1000 // Whether this object is needed. This is only set for dynamic
1001 // objects, and means that the object defined a symbol which was
1002 // used by a reference from a regular object.
1003 bool is_needed_ : 1;
1004 // Whether this object was compiled with -fsplit-stack.
1005 bool uses_split_stack_ : 1;
1006 // Whether this object contains any functions compiled with the
1007 // no_split_stack attribute.
1008 bool has_no_split_stack_ : 1;
1009 // True if exclude this object from automatic symbol export.
1010 // This is used only for archive objects.
1011 bool no_export_ : 1;
1012 // True if the object was found in a system directory.
1013 bool is_in_system_directory_ : 1;
1014 // True if the object was linked with --as-needed.
1015 bool as_needed_ : 1;
1016 // Many sections for objects with more than SHN_LORESERVE sections.
1018 // For compressed debug sections, map section index to uncompressed size
1020 Compressed_section_map* compressed_sections_;
1023 // A regular object (ET_REL). This is an abstract base class itself.
1024 // The implementation is the template class Sized_relobj_file.
1026 class Relobj : public Object
1029 Relobj(const std::string& name, Input_file* input_file, off_t offset = 0)
1030 : Object(name, input_file, false, offset),
1032 map_to_relocatable_relocs_(NULL),
1033 object_merge_map_(NULL),
1034 relocs_must_follow_section_writes_(false),
1036 reloc_counts_(NULL),
1038 first_dyn_reloc_(0),
1042 // During garbage collection, the Read_symbols_data pass for
1043 // each object is stored as layout needs to be done after
1044 // reloc processing.
1047 { return this->sd_; }
1049 // Decides which section names have to be included in the worklist
1052 is_section_name_included(const char* name);
1055 copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
1056 unsigned int section_header_size);
1059 set_symbols_data(Symbols_data* sd)
1062 // During garbage collection, the Read_relocs pass for all objects
1063 // is done before scanning the relocs. In that case, this->rd_ is
1064 // used to store the information from Read_relocs for each object.
1065 // This data is also used to compute the list of relevant sections.
1068 { return this->rd_; }
1071 set_relocs_data(Read_relocs_data* rd)
1075 is_output_section_offset_invalid(unsigned int shndx) const = 0;
1079 read_relocs(Read_relocs_data* rd)
1080 { return this->do_read_relocs(rd); }
1082 // Process the relocs, during garbage collection only.
1084 gc_process_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd)
1085 { return this->do_gc_process_relocs(symtab, layout, rd); }
1087 // Scan the relocs and adjust the symbol table.
1089 scan_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd)
1090 { return this->do_scan_relocs(symtab, layout, rd); }
1092 // Return the value of the local symbol whose index is SYMNDX, plus
1093 // ADDEND. ADDEND is passed in so that we can correctly handle the
1094 // section symbol for a merge section.
1096 local_symbol_value(unsigned int symndx, uint64_t addend) const
1097 { return this->do_local_symbol_value(symndx, addend); }
1099 // Return the PLT offset for a local symbol. It is an error to call
1100 // this if it doesn't have one.
1102 local_plt_offset(unsigned int symndx) const
1103 { return this->do_local_plt_offset(symndx); }
1105 // Return whether the local symbol SYMNDX has a GOT offset of type
1108 local_has_got_offset(unsigned int symndx, unsigned int got_type) const
1109 { return this->do_local_has_got_offset(symndx, got_type); }
1111 // Return the GOT offset of type GOT_TYPE of the local symbol
1112 // SYMNDX. It is an error to call this if the symbol does not have
1113 // a GOT offset of the specified type.
1115 local_got_offset(unsigned int symndx, unsigned int got_type) const
1116 { return this->do_local_got_offset(symndx, got_type); }
1118 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1121 set_local_got_offset(unsigned int symndx, unsigned int got_type,
1122 unsigned int got_offset)
1123 { this->do_set_local_got_offset(symndx, got_type, got_offset); }
1125 // Return whether the local symbol SYMNDX is a TLS symbol.
1127 local_is_tls(unsigned int symndx) const
1128 { return this->do_local_is_tls(symndx); }
1130 // The number of local symbols in the input symbol table.
1131 virtual unsigned int
1132 local_symbol_count() const
1133 { return this->do_local_symbol_count(); }
1135 // The number of local symbols in the output symbol table.
1136 virtual unsigned int
1137 output_local_symbol_count() const
1138 { return this->do_output_local_symbol_count(); }
1140 // The file offset for local symbols in the output symbol table.
1142 local_symbol_offset() const
1143 { return this->do_local_symbol_offset(); }
1145 // Initial local symbol processing: count the number of local symbols
1146 // in the output symbol table and dynamic symbol table; add local symbol
1147 // names to *POOL and *DYNPOOL.
1149 count_local_symbols(Stringpool_template<char>* pool,
1150 Stringpool_template<char>* dynpool)
1151 { return this->do_count_local_symbols(pool, dynpool); }
1153 // Set the values of the local symbols, set the output symbol table
1154 // indexes for the local variables, and set the offset where local
1155 // symbol information will be stored. Returns the new local symbol index.
1157 finalize_local_symbols(unsigned int index, off_t off, Symbol_table* symtab)
1158 { return this->do_finalize_local_symbols(index, off, symtab); }
1160 // Set the output dynamic symbol table indexes for the local variables.
1162 set_local_dynsym_indexes(unsigned int index)
1163 { return this->do_set_local_dynsym_indexes(index); }
1165 // Set the offset where local dynamic symbol information will be stored.
1167 set_local_dynsym_offset(off_t off)
1168 { return this->do_set_local_dynsym_offset(off); }
1170 // Record a dynamic relocation against an input section from this object.
1172 add_dyn_reloc(unsigned int index)
1174 if (this->dyn_reloc_count_ == 0)
1175 this->first_dyn_reloc_ = index;
1176 ++this->dyn_reloc_count_;
1179 // Return the index of the first dynamic relocation.
1181 first_dyn_reloc() const
1182 { return this->first_dyn_reloc_; }
1184 // Return the count of dynamic relocations.
1186 dyn_reloc_count() const
1187 { return this->dyn_reloc_count_; }
1189 // Relocate the input sections and write out the local symbols.
1191 relocate(const Symbol_table* symtab, const Layout* layout, Output_file* of)
1192 { return this->do_relocate(symtab, layout, of); }
1194 // Return whether an input section is being included in the link.
1196 is_section_included(unsigned int shndx) const
1198 gold_assert(shndx < this->output_sections_.size());
1199 return this->output_sections_[shndx] != NULL;
1202 // The output section of the input section with index SHNDX.
1203 // This is only used currently to remove a section from the link in
1206 set_output_section(unsigned int shndx, Output_section* os)
1208 gold_assert(shndx < this->output_sections_.size());
1209 this->output_sections_[shndx] = os;
1212 // Set the offset of an input section within its output section.
1214 set_section_offset(unsigned int shndx, uint64_t off)
1215 { this->do_set_section_offset(shndx, off); }
1217 // Return true if we need to wait for output sections to be written
1218 // before we can apply relocations. This is true if the object has
1219 // any relocations for sections which require special handling, such
1220 // as the exception frame section.
1222 relocs_must_follow_section_writes() const
1223 { return this->relocs_must_follow_section_writes_; }
1226 get_or_create_merge_map();
1230 initialize_input_to_output_map(unsigned int shndx,
1231 typename elfcpp::Elf_types<size>::Elf_Addr starting_address,
1232 Unordered_map<section_offset_type,
1233 typename elfcpp::Elf_types<size>::Elf_Addr>* output_address) const;
1236 add_merge_mapping(Output_section_data *output_data,
1237 unsigned int shndx, section_offset_type offset,
1238 section_size_type length,
1239 section_offset_type output_offset);
1242 merge_output_offset(unsigned int shndx, section_offset_type offset,
1243 section_offset_type *poutput) const;
1245 const Output_section_data*
1246 find_merge_section(unsigned int shndx) const;
1248 // Record the relocatable reloc info for an input reloc section.
1250 set_relocatable_relocs(unsigned int reloc_shndx, Relocatable_relocs* rr)
1252 gold_assert(reloc_shndx < this->shnum());
1253 (*this->map_to_relocatable_relocs_)[reloc_shndx] = rr;
1256 // Get the relocatable reloc info for an input reloc section.
1258 relocatable_relocs(unsigned int reloc_shndx)
1260 gold_assert(reloc_shndx < this->shnum());
1261 return (*this->map_to_relocatable_relocs_)[reloc_shndx];
1264 // Layout sections whose layout was deferred while waiting for
1265 // input files from a plugin.
1267 layout_deferred_sections(Layout* layout)
1268 { this->do_layout_deferred_sections(layout); }
1270 // Return the index of the first incremental relocation for symbol SYMNDX.
1271 virtual unsigned int
1272 do_get_incremental_reloc_base(unsigned int symndx) const
1273 { return this->reloc_bases_[symndx]; }
1275 // Return the number of incremental relocations for symbol SYMNDX.
1276 virtual unsigned int
1277 do_get_incremental_reloc_count(unsigned int symndx) const
1278 { return this->reloc_counts_[symndx]; }
1280 // Return the word size of the object file.
1283 { return this->do_elfsize(); }
1285 // Return TRUE if this is a big-endian object file.
1287 is_big_endian() const
1288 { return this->do_is_big_endian(); }
1291 // The output section to be used for each input section, indexed by
1292 // the input section number. The output section is NULL if the
1293 // input section is to be discarded.
1294 typedef std::vector<Output_section*> Output_sections;
1296 // Read the relocs--implemented by child class.
1298 do_read_relocs(Read_relocs_data*) = 0;
1300 // Process the relocs--implemented by child class.
1302 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0;
1304 // Scan the relocs--implemented by child class.
1306 do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0;
1308 // Return the value of a local symbol.
1310 do_local_symbol_value(unsigned int symndx, uint64_t addend) const = 0;
1312 // Return the PLT offset of a local symbol.
1313 virtual unsigned int
1314 do_local_plt_offset(unsigned int symndx) const = 0;
1316 // Return whether a local symbol has a GOT offset of a given type.
1318 do_local_has_got_offset(unsigned int symndx,
1319 unsigned int got_type) const = 0;
1321 // Return the GOT offset of a given type of a local symbol.
1322 virtual unsigned int
1323 do_local_got_offset(unsigned int symndx, unsigned int got_type) const = 0;
1325 // Set the GOT offset with a given type for a local symbol.
1327 do_set_local_got_offset(unsigned int symndx, unsigned int got_type,
1328 unsigned int got_offset) = 0;
1330 // Return whether local symbol SYMNDX is a TLS symbol.
1332 do_local_is_tls(unsigned int symndx) const = 0;
1334 // Return the number of local symbols--implemented by child class.
1335 virtual unsigned int
1336 do_local_symbol_count() const = 0;
1338 // Return the number of output local symbols--implemented by child class.
1339 virtual unsigned int
1340 do_output_local_symbol_count() const = 0;
1342 // Return the file offset for local symbols--implemented by child class.
1344 do_local_symbol_offset() const = 0;
1346 // Count local symbols--implemented by child class.
1348 do_count_local_symbols(Stringpool_template<char>*,
1349 Stringpool_template<char>*) = 0;
1351 // Finalize the local symbols. Set the output symbol table indexes
1352 // for the local variables, and set the offset where local symbol
1353 // information will be stored.
1354 virtual unsigned int
1355 do_finalize_local_symbols(unsigned int, off_t, Symbol_table*) = 0;
1357 // Set the output dynamic symbol table indexes for the local variables.
1358 virtual unsigned int
1359 do_set_local_dynsym_indexes(unsigned int) = 0;
1361 // Set the offset where local dynamic symbol information will be stored.
1362 virtual unsigned int
1363 do_set_local_dynsym_offset(off_t) = 0;
1365 // Relocate the input sections and write out the local
1366 // symbols--implemented by child class.
1368 do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of) = 0;
1370 // Set the offset of a section--implemented by child class.
1372 do_set_section_offset(unsigned int shndx, uint64_t off) = 0;
1374 // Layout sections whose layout was deferred while waiting for
1375 // input files from a plugin--implemented by child class.
1377 do_layout_deferred_sections(Layout*) = 0;
1379 // Given a section index, return the corresponding Output_section.
1380 // The return value will be NULL if the section is not included in
1383 do_output_section(unsigned int shndx) const
1385 gold_assert(shndx < this->output_sections_.size());
1386 return this->output_sections_[shndx];
1389 // Return the vector mapping input sections to output sections.
1392 { return this->output_sections_; }
1394 const Output_sections&
1395 output_sections() const
1396 { return this->output_sections_; }
1398 // Set the size of the relocatable relocs array.
1400 size_relocatable_relocs()
1402 this->map_to_relocatable_relocs_ =
1403 new std::vector<Relocatable_relocs*>(this->shnum());
1406 // Record that we must wait for the output sections to be written
1407 // before applying relocations.
1409 set_relocs_must_follow_section_writes()
1410 { this->relocs_must_follow_section_writes_ = true; }
1412 // Allocate the array for counting incremental relocations.
1414 allocate_incremental_reloc_counts()
1416 unsigned int nsyms = this->do_get_global_symbols()->size();
1417 this->reloc_counts_ = new unsigned int[nsyms];
1418 gold_assert(this->reloc_counts_ != NULL);
1419 memset(this->reloc_counts_, 0, nsyms * sizeof(unsigned int));
1422 // Record a relocation in this object referencing global symbol SYMNDX.
1423 // Used for tracking incremental link information.
1425 count_incremental_reloc(unsigned int symndx)
1427 unsigned int nsyms = this->do_get_global_symbols()->size();
1428 gold_assert(symndx < nsyms);
1429 gold_assert(this->reloc_counts_ != NULL);
1430 ++this->reloc_counts_[symndx];
1433 // Finalize the incremental relocation information.
1435 finalize_incremental_relocs(Layout* layout, bool clear_counts);
1437 // Return the index of the next relocation to be written for global symbol
1438 // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
1440 next_incremental_reloc_index(unsigned int symndx)
1442 unsigned int nsyms = this->do_get_global_symbols()->size();
1444 gold_assert(this->reloc_counts_ != NULL);
1445 gold_assert(this->reloc_bases_ != NULL);
1446 gold_assert(symndx < nsyms);
1448 unsigned int counter = this->reloc_counts_[symndx]++;
1449 return this->reloc_bases_[symndx] + counter;
1452 // Return the word size of the object file--
1453 // implemented by child class.
1455 do_elfsize() const = 0;
1457 // Return TRUE if this is a big-endian object file--
1458 // implemented by child class.
1460 do_is_big_endian() const = 0;
1463 // Mapping from input sections to output section.
1464 Output_sections output_sections_;
1465 // Mapping from input section index to the information recorded for
1466 // the relocations. This is only used for a relocatable link.
1467 std::vector<Relocatable_relocs*>* map_to_relocatable_relocs_;
1468 // Mappings for merge sections. This is managed by the code in the
1470 Object_merge_map* object_merge_map_;
1471 // Whether we need to wait for output sections to be written before
1472 // we can apply relocations.
1473 bool relocs_must_follow_section_writes_;
1474 // Used to store the relocs data computed by the Read_relocs pass.
1475 // Used during garbage collection of unused sections.
1476 Read_relocs_data* rd_;
1477 // Used to store the symbols data computed by the Read_symbols pass.
1478 // Again used during garbage collection when laying out referenced
1480 gold::Symbols_data* sd_;
1481 // Per-symbol counts of relocations, for incremental links.
1482 unsigned int* reloc_counts_;
1483 // Per-symbol base indexes of relocations, for incremental links.
1484 unsigned int* reloc_bases_;
1485 // Index of the first dynamic relocation for this object.
1486 unsigned int first_dyn_reloc_;
1487 // Count of dynamic relocations for this object.
1488 unsigned int dyn_reloc_count_;
1491 // This class is used to handle relocations against a section symbol
1492 // in an SHF_MERGE section. For such a symbol, we need to know the
1493 // addend of the relocation before we can determine the final value.
1494 // The addend gives us the location in the input section, and we can
1495 // determine how it is mapped to the output section. For a
1496 // non-section symbol, we apply the addend to the final value of the
1497 // symbol; that is done in finalize_local_symbols, and does not use
1501 class Merged_symbol_value
1504 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value;
1506 // We use a hash table to map offsets in the input section to output
1508 typedef Unordered_map<section_offset_type, Value> Output_addresses;
1510 Merged_symbol_value(Value input_value, Value output_start_address)
1511 : input_value_(input_value), output_start_address_(output_start_address),
1515 // Initialize the hash table.
1517 initialize_input_to_output_map(const Relobj*, unsigned int input_shndx);
1519 // Release the hash table to save space.
1521 free_input_to_output_map()
1522 { this->output_addresses_.clear(); }
1524 // Get the output value corresponding to an addend. The object and
1525 // input section index are passed in because the caller will have
1526 // them; otherwise we could store them here.
1528 value(const Relobj* object, unsigned int input_shndx, Value addend) const
1530 // This is a relocation against a section symbol. ADDEND is the
1531 // offset in the section. The result should be the start of some
1532 // merge area. If the object file wants something else, it should
1533 // use a regular symbol rather than a section symbol.
1534 // Unfortunately, PR 6658 shows a case in which the object file
1535 // refers to the section symbol, but uses a negative ADDEND to
1536 // compensate for a PC relative reloc. We can't handle the
1537 // general case. However, we can handle the special case of a
1538 // negative addend, by assuming that it refers to the start of the
1539 // section. Of course, that means that we have to guess when
1540 // ADDEND is negative. It is normal to see a 32-bit value here
1541 // even when the template parameter size is 64, as 64-bit object
1542 // file formats have 32-bit relocations. We know this is a merge
1543 // section, so we know it has to fit into memory. So we assume
1544 // that we won't see a value larger than a large 32-bit unsigned
1545 // value. This will break objects with very very large merge
1546 // sections; they probably break in other ways anyhow.
1547 Value input_offset = this->input_value_;
1548 if (addend < 0xffffff00)
1550 input_offset += addend;
1553 typename Output_addresses::const_iterator p =
1554 this->output_addresses_.find(input_offset);
1555 if (p != this->output_addresses_.end())
1556 return p->second + addend;
1558 return (this->value_from_output_section(object, input_shndx, input_offset)
1563 // Get the output value for an input offset if we couldn't find it
1564 // in the hash table.
1566 value_from_output_section(const Relobj*, unsigned int input_shndx,
1567 Value input_offset) const;
1569 // The value of the section symbol in the input file. This is
1570 // normally zero, but could in principle be something else.
1572 // The start address of this merged section in the output file.
1573 Value output_start_address_;
1574 // A hash table which maps offsets in the input section to output
1575 // addresses. This only maps specific offsets, not all offsets.
1576 Output_addresses output_addresses_;
1579 // This POD class is holds the value of a symbol. This is used for
1580 // local symbols, and for all symbols during relocation processing.
1581 // For special sections, such as SHF_MERGE sections, this calls a
1582 // function to get the final symbol value.
1588 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value;
1591 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1592 is_ordinary_shndx_(false), is_section_symbol_(false),
1593 is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
1594 { this->u_.value = 0; }
1598 if (!this->has_output_value_)
1599 delete this->u_.merged_symbol_value;
1602 // Get the value of this symbol. OBJECT is the object in which this
1603 // symbol is defined, and ADDEND is an addend to add to the value.
1604 template<bool big_endian>
1606 value(const Sized_relobj_file<size, big_endian>* object, Value addend) const
1608 if (this->has_output_value_)
1609 return this->u_.value + addend;
1612 gold_assert(this->is_ordinary_shndx_);
1613 return this->u_.merged_symbol_value->value(object, this->input_shndx_,
1618 // Set the value of this symbol in the output symbol table.
1620 set_output_value(Value value)
1621 { this->u_.value = value; }
1623 // For a section symbol in a merged section, we need more
1626 set_merged_symbol_value(Merged_symbol_value<size>* msv)
1628 gold_assert(this->is_section_symbol_);
1629 this->has_output_value_ = false;
1630 this->u_.merged_symbol_value = msv;
1633 // Initialize the input to output map for a section symbol in a
1634 // merged section. We also initialize the value of a non-section
1635 // symbol in a merged section.
1637 initialize_input_to_output_map(const Relobj* object)
1639 if (!this->has_output_value_)
1641 gold_assert(this->is_section_symbol_ && this->is_ordinary_shndx_);
1642 Merged_symbol_value<size>* msv = this->u_.merged_symbol_value;
1643 msv->initialize_input_to_output_map(object, this->input_shndx_);
1647 // Free the input to output map for a section symbol in a merged
1650 free_input_to_output_map()
1652 if (!this->has_output_value_)
1653 this->u_.merged_symbol_value->free_input_to_output_map();
1656 // Set the value of the symbol from the input file. This is only
1657 // called by count_local_symbols, to communicate the value to
1658 // finalize_local_symbols.
1660 set_input_value(Value value)
1661 { this->u_.value = value; }
1663 // Return the input value. This is only called by
1664 // finalize_local_symbols and (in special cases) relocate_section.
1667 { return this->u_.value; }
1669 // Return whether we have set the index in the output symbol table
1672 is_output_symtab_index_set() const
1674 return (this->output_symtab_index_ != 0
1675 && this->output_symtab_index_ != -2U);
1678 // Return whether this symbol may be discarded from the normal
1681 may_be_discarded_from_output_symtab() const
1683 gold_assert(!this->is_output_symtab_index_set());
1684 return this->output_symtab_index_ != -2U;
1687 // Return whether this symbol has an entry in the output symbol
1690 has_output_symtab_entry() const
1692 gold_assert(this->is_output_symtab_index_set());
1693 return this->output_symtab_index_ != -1U;
1696 // Return the index in the output symbol table.
1698 output_symtab_index() const
1700 gold_assert(this->is_output_symtab_index_set()
1701 && this->output_symtab_index_ != -1U);
1702 return this->output_symtab_index_;
1705 // Set the index in the output symbol table.
1707 set_output_symtab_index(unsigned int i)
1709 gold_assert(!this->is_output_symtab_index_set());
1710 gold_assert(i != 0 && i != -1U && i != -2U);
1711 this->output_symtab_index_ = i;
1714 // Record that this symbol should not go into the output symbol
1717 set_no_output_symtab_entry()
1719 gold_assert(this->output_symtab_index_ == 0);
1720 this->output_symtab_index_ = -1U;
1723 // Record that this symbol must go into the output symbol table,
1724 // because it there is a relocation that uses it.
1726 set_must_have_output_symtab_entry()
1728 gold_assert(!this->is_output_symtab_index_set());
1729 this->output_symtab_index_ = -2U;
1732 // Set the index in the output dynamic symbol table.
1734 set_needs_output_dynsym_entry()
1736 gold_assert(!this->is_section_symbol());
1737 this->output_dynsym_index_ = 0;
1740 // Return whether this symbol should go into the dynamic symbol
1743 needs_output_dynsym_entry() const
1745 return this->output_dynsym_index_ != -1U;
1748 // Return whether this symbol has an entry in the dynamic symbol
1751 has_output_dynsym_entry() const
1753 gold_assert(this->output_dynsym_index_ != 0);
1754 return this->output_dynsym_index_ != -1U;
1757 // Record that this symbol should go into the dynamic symbol table.
1759 set_output_dynsym_index(unsigned int i)
1761 gold_assert(this->output_dynsym_index_ == 0);
1762 gold_assert(i != 0 && i != -1U);
1763 this->output_dynsym_index_ = i;
1766 // Return the index in the output dynamic symbol table.
1768 output_dynsym_index() const
1770 gold_assert(this->output_dynsym_index_ != 0
1771 && this->output_dynsym_index_ != -1U);
1772 return this->output_dynsym_index_;
1775 // Set the index of the input section in the input file.
1777 set_input_shndx(unsigned int i, bool is_ordinary)
1779 this->input_shndx_ = i;
1780 // input_shndx_ field is a bitfield, so make sure that the value
1782 gold_assert(this->input_shndx_ == i);
1783 this->is_ordinary_shndx_ = is_ordinary;
1786 // Return the index of the input section in the input file.
1788 input_shndx(bool* is_ordinary) const
1790 *is_ordinary = this->is_ordinary_shndx_;
1791 return this->input_shndx_;
1794 // Whether this is a section symbol.
1796 is_section_symbol() const
1797 { return this->is_section_symbol_; }
1799 // Record that this is a section symbol.
1801 set_is_section_symbol()
1803 gold_assert(!this->needs_output_dynsym_entry());
1804 this->is_section_symbol_ = true;
1807 // Record that this is a TLS symbol.
1810 { this->is_tls_symbol_ = true; }
1812 // Return true if this is a TLS symbol.
1814 is_tls_symbol() const
1815 { return this->is_tls_symbol_; }
1817 // Record that this is an IFUNC symbol.
1819 set_is_ifunc_symbol()
1820 { this->is_ifunc_symbol_ = true; }
1822 // Return true if this is an IFUNC symbol.
1824 is_ifunc_symbol() const
1825 { return this->is_ifunc_symbol_; }
1827 // Return true if this has output value.
1829 has_output_value() const
1830 { return this->has_output_value_; }
1833 // The index of this local symbol in the output symbol table. This
1834 // will be 0 if no value has been assigned yet, and the symbol may
1835 // be omitted. This will be -1U if the symbol should not go into
1836 // the symbol table. This will be -2U if the symbol must go into
1837 // the symbol table, but no index has been assigned yet.
1838 unsigned int output_symtab_index_;
1839 // The index of this local symbol in the dynamic symbol table. This
1840 // will be -1U if the symbol should not go into the symbol table.
1841 unsigned int output_dynsym_index_;
1842 // The section index in the input file in which this symbol is
1844 unsigned int input_shndx_ : 27;
1845 // Whether the section index is an ordinary index, not a special
1847 bool is_ordinary_shndx_ : 1;
1848 // Whether this is a STT_SECTION symbol.
1849 bool is_section_symbol_ : 1;
1850 // Whether this is a STT_TLS symbol.
1851 bool is_tls_symbol_ : 1;
1852 // Whether this is a STT_GNU_IFUNC symbol.
1853 bool is_ifunc_symbol_ : 1;
1854 // Whether this symbol has a value for the output file. This is
1855 // normally set to true during Layout::finalize, by
1856 // finalize_local_symbols. It will be false for a section symbol in
1857 // a merge section, as for such symbols we can not determine the
1858 // value to use in a relocation until we see the addend.
1859 bool has_output_value_ : 1;
1862 // This is used if has_output_value_ is true. Between
1863 // count_local_symbols and finalize_local_symbols, this is the
1864 // value in the input file. After finalize_local_symbols, it is
1865 // the value in the output file.
1867 // This is used if has_output_value_ is false. It points to the
1868 // information we need to get the value for a merge section.
1869 Merged_symbol_value<size>* merged_symbol_value;
1873 // This type is used to modify relocations for -fsplit-stack. It is
1874 // indexed by relocation index, and means that the relocation at that
1875 // index should use the symbol from the vector, rather than the one
1876 // indicated by the relocation.
1878 class Reloc_symbol_changes
1881 Reloc_symbol_changes(size_t count)
1886 set(size_t i, Symbol* sym)
1887 { this->vec_[i] = sym; }
1890 operator[](size_t i) const
1891 { return this->vec_[i]; }
1894 std::vector<Symbol*> vec_;
1897 // Abstract base class for a regular object file, either a real object file
1898 // or an incremental (unchanged) object. This is size and endian specific.
1900 template<int size, bool big_endian>
1901 class Sized_relobj : public Relobj
1904 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
1905 typedef Relobj::Symbols Symbols;
1907 static const Address invalid_address = static_cast<Address>(0) - 1;
1909 Sized_relobj(const std::string& name, Input_file* input_file)
1910 : Relobj(name, input_file), local_got_offsets_(), section_offsets_()
1913 Sized_relobj(const std::string& name, Input_file* input_file,
1915 : Relobj(name, input_file, offset), local_got_offsets_(), section_offsets_()
1921 // If this is a regular object, return a pointer to the Sized_relobj_file
1922 // object. Otherwise, return NULL.
1923 virtual Sized_relobj_file<size, big_endian>*
1927 const virtual Sized_relobj_file<size, big_endian>*
1928 sized_relobj() const
1931 // Checks if the offset of input section SHNDX within its output
1932 // section is invalid.
1934 is_output_section_offset_invalid(unsigned int shndx) const
1935 { return this->get_output_section_offset(shndx) == invalid_address; }
1937 // Get the offset of input section SHNDX within its output section.
1938 // This is -1 if the input section requires a special mapping, such
1939 // as a merge section. The output section can be found in the
1940 // output_sections_ field of the parent class Relobj.
1942 get_output_section_offset(unsigned int shndx) const
1944 gold_assert(shndx < this->section_offsets_.size());
1945 return this->section_offsets_[shndx];
1948 // Iterate over local symbols, calling a visitor class V for each GOT offset
1949 // associated with a local symbol.
1951 do_for_all_local_got_entries(Got_offset_list::Visitor* v) const;
1954 typedef Relobj::Output_sections Output_sections;
1956 // Clear the local symbol information.
1959 { this->local_got_offsets_.clear(); }
1961 // Return the vector of section offsets.
1962 std::vector<Address>&
1964 { return this->section_offsets_; }
1966 // Get the address of an output section.
1968 do_output_section_address(unsigned int shndx);
1970 // Get the offset of a section.
1972 do_output_section_offset(unsigned int shndx) const
1974 Address off = this->get_output_section_offset(shndx);
1975 if (off == invalid_address)
1980 // Set the offset of a section.
1982 do_set_section_offset(unsigned int shndx, uint64_t off)
1984 gold_assert(shndx < this->section_offsets_.size());
1985 this->section_offsets_[shndx] =
1986 (off == static_cast<uint64_t>(-1)
1988 : convert_types<Address, uint64_t>(off));
1991 // Return whether the local symbol SYMNDX has a GOT offset of type
1994 do_local_has_got_offset(unsigned int symndx, unsigned int got_type) const
1996 Local_got_offsets::const_iterator p =
1997 this->local_got_offsets_.find(symndx);
1998 return (p != this->local_got_offsets_.end()
1999 && p->second->get_offset(got_type) != -1U);
2002 // Return the GOT offset of type GOT_TYPE of the local symbol
2005 do_local_got_offset(unsigned int symndx, unsigned int got_type) const
2007 Local_got_offsets::const_iterator p =
2008 this->local_got_offsets_.find(symndx);
2009 gold_assert(p != this->local_got_offsets_.end());
2010 unsigned int off = p->second->get_offset(got_type);
2011 gold_assert(off != -1U);
2015 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
2018 do_set_local_got_offset(unsigned int symndx, unsigned int got_type,
2019 unsigned int got_offset)
2021 Local_got_offsets::const_iterator p =
2022 this->local_got_offsets_.find(symndx);
2023 if (p != this->local_got_offsets_.end())
2024 p->second->set_offset(got_type, got_offset);
2027 Got_offset_list* g = new Got_offset_list(got_type, got_offset);
2028 std::pair<Local_got_offsets::iterator, bool> ins =
2029 this->local_got_offsets_.insert(std::make_pair(symndx, g));
2030 gold_assert(ins.second);
2034 // Return the word size of the object file.
2039 // Return TRUE if this is a big-endian object file.
2041 do_is_big_endian() const
2042 { return big_endian; }
2045 // The GOT offsets of local symbols. This map also stores GOT offsets
2046 // for tp-relative offsets for TLS symbols.
2047 typedef Unordered_map<unsigned int, Got_offset_list*> Local_got_offsets;
2049 // GOT offsets for local non-TLS symbols, and tp-relative offsets
2050 // for TLS symbols, indexed by symbol number.
2051 Local_got_offsets local_got_offsets_;
2052 // For each input section, the offset of the input section in its
2053 // output section. This is INVALID_ADDRESS if the input section requires a
2055 std::vector<Address> section_offsets_;
2058 // A regular object file. This is size and endian specific.
2060 template<int size, bool big_endian>
2061 class Sized_relobj_file : public Sized_relobj<size, big_endian>
2064 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
2065 typedef typename Sized_relobj<size, big_endian>::Symbols Symbols;
2066 typedef std::vector<Symbol_value<size> > Local_values;
2068 static const Address invalid_address = static_cast<Address>(0) - 1;
2070 enum Compute_final_local_value_status
2074 // An error occurred.
2076 // The local symbol has no output section.
2080 Sized_relobj_file(const std::string& name,
2081 Input_file* input_file,
2083 const typename elfcpp::Ehdr<size, big_endian>&);
2085 ~Sized_relobj_file();
2087 // Set up the object file based on TARGET.
2090 { this->do_setup(); }
2092 // Return a pointer to the Sized_relobj_file object.
2093 Sized_relobj_file<size, big_endian>*
2097 const Sized_relobj_file<size, big_endian>*
2098 sized_relobj() const
2101 // Return the ELF file type.
2104 { return this->e_type_; }
2106 // Return the number of symbols. This is only valid after
2107 // Object::add_symbols has been called.
2109 symbol_count() const
2110 { return this->local_symbol_count_ + this->symbols_.size(); }
2112 // If SYM is the index of a global symbol in the object file's
2113 // symbol table, return the Symbol object. Otherwise, return NULL.
2115 global_symbol(unsigned int sym) const
2117 if (sym >= this->local_symbol_count_)
2119 gold_assert(sym - this->local_symbol_count_ < this->symbols_.size());
2120 return this->symbols_[sym - this->local_symbol_count_];
2125 // Return the section index of symbol SYM. Set *VALUE to its value
2126 // in the object file. Set *IS_ORDINARY if this is an ordinary
2127 // section index, not a special code between SHN_LORESERVE and
2128 // SHN_HIRESERVE. Note that for a symbol which is not defined in
2129 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
2130 // it will not return the final value of the symbol in the link.
2132 symbol_section_and_value(unsigned int sym, Address* value, bool* is_ordinary);
2134 // Return a pointer to the Symbol_value structure which holds the
2135 // value of a local symbol.
2136 const Symbol_value<size>*
2137 local_symbol(unsigned int sym) const
2139 gold_assert(sym < this->local_values_.size());
2140 return &this->local_values_[sym];
2143 // Return the index of local symbol SYM in the ordinary symbol
2144 // table. A value of -1U means that the symbol is not being output.
2146 symtab_index(unsigned int sym) const
2148 gold_assert(sym < this->local_values_.size());
2149 return this->local_values_[sym].output_symtab_index();
2152 // Return the index of local symbol SYM in the dynamic symbol
2153 // table. A value of -1U means that the symbol is not being output.
2155 dynsym_index(unsigned int sym) const
2157 gold_assert(sym < this->local_values_.size());
2158 return this->local_values_[sym].output_dynsym_index();
2161 // Return the input section index of local symbol SYM.
2163 local_symbol_input_shndx(unsigned int sym, bool* is_ordinary) const
2165 gold_assert(sym < this->local_values_.size());
2166 return this->local_values_[sym].input_shndx(is_ordinary);
2169 // Record that local symbol SYM must be in the output symbol table.
2171 set_must_have_output_symtab_entry(unsigned int sym)
2173 gold_assert(sym < this->local_values_.size());
2174 this->local_values_[sym].set_must_have_output_symtab_entry();
2177 // Record that local symbol SYM needs a dynamic symbol entry.
2179 set_needs_output_dynsym_entry(unsigned int sym)
2181 gold_assert(sym < this->local_values_.size());
2182 this->local_values_[sym].set_needs_output_dynsym_entry();
2185 // Return whether the local symbol SYMNDX has a PLT offset.
2187 local_has_plt_offset(unsigned int symndx) const;
2189 // Set the PLT offset of the local symbol SYMNDX.
2191 set_local_plt_offset(unsigned int symndx, unsigned int plt_offset);
2193 // Adjust this local symbol value. Return false if the symbol
2194 // should be discarded from the output file.
2196 adjust_local_symbol(Symbol_value<size>* lv) const
2197 { return this->do_adjust_local_symbol(lv); }
2199 // Return the name of the symbol that spans the given offset in the
2200 // specified section in this object. This is used only for error
2201 // messages and is not particularly efficient.
2203 get_symbol_location_info(unsigned int shndx, off_t offset,
2204 Symbol_location_info* info);
2206 // Look for a kept section corresponding to the given discarded section,
2207 // and return its output address. This is used only for relocations in
2208 // debugging sections.
2210 map_to_kept_section(unsigned int shndx, bool* found) const;
2212 // Compute final local symbol value. R_SYM is the local symbol index.
2213 // LV_IN points to a local symbol value containing the input value.
2214 // LV_OUT points to a local symbol value storing the final output value,
2215 // which must not be a merged symbol value since before calling this
2216 // method to avoid memory leak. SYMTAB points to a symbol table.
2218 // The method returns a status code at return. If the return status is
2219 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2220 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2221 // *LV_OUT is not modified.
2222 Compute_final_local_value_status
2223 compute_final_local_value(unsigned int r_sym,
2224 const Symbol_value<size>* lv_in,
2225 Symbol_value<size>* lv_out,
2226 const Symbol_table* symtab);
2228 // Return true if the layout for this object was deferred.
2229 bool is_deferred_layout() const
2230 { return this->is_deferred_layout_; }
2233 typedef typename Sized_relobj<size, big_endian>::Output_sections
2240 // Read the symbols.
2242 do_read_symbols(Read_symbols_data*);
2244 // Read the symbols. This is common code for all target-specific
2245 // overrides of do_read_symbols.
2247 base_read_symbols(Read_symbols_data*);
2249 // Return the value of a local symbol.
2251 do_local_symbol_value(unsigned int symndx, uint64_t addend) const
2253 const Symbol_value<size>* symval = this->local_symbol(symndx);
2254 return symval->value(this, addend);
2257 // Return the PLT offset for a local symbol. It is an error to call
2258 // this if it doesn't have one.
2260 do_local_plt_offset(unsigned int symndx) const;
2262 // Return whether local symbol SYMNDX is a TLS symbol.
2264 do_local_is_tls(unsigned int symndx) const
2265 { return this->local_symbol(symndx)->is_tls_symbol(); }
2267 // Return the number of local symbols.
2269 do_local_symbol_count() const
2270 { return this->local_symbol_count_; }
2272 // Return the number of local symbols in the output symbol table.
2274 do_output_local_symbol_count() const
2275 { return this->output_local_symbol_count_; }
2277 // Return the number of local symbols in the output symbol table.
2279 do_local_symbol_offset() const
2280 { return this->local_symbol_offset_; }
2282 // Lay out the input sections.
2284 do_layout(Symbol_table*, Layout*, Read_symbols_data*);
2286 // Layout sections whose layout was deferred while waiting for
2287 // input files from a plugin.
2289 do_layout_deferred_sections(Layout*);
2291 // Add the symbols to the symbol table.
2293 do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
2295 Archive::Should_include
2296 do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
2299 // Iterate over global symbols, calling a visitor class V for each.
2301 do_for_all_global_symbols(Read_symbols_data* sd,
2302 Library_base::Symbol_visitor_base* v);
2306 do_read_relocs(Read_relocs_data*);
2308 // Process the relocs to find list of referenced sections. Used only
2309 // during garbage collection.
2311 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
2313 // Scan the relocs and adjust the symbol table.
2315 do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*);
2317 // Count the local symbols.
2319 do_count_local_symbols(Stringpool_template<char>*,
2320 Stringpool_template<char>*);
2322 // Finalize the local symbols.
2324 do_finalize_local_symbols(unsigned int, off_t, Symbol_table*);
2326 // Set the offset where local dynamic symbol information will be stored.
2328 do_set_local_dynsym_indexes(unsigned int);
2330 // Set the offset where local dynamic symbol information will be stored.
2332 do_set_local_dynsym_offset(off_t);
2334 // Relocate the input sections and write out the local symbols.
2336 do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of);
2338 // Get the size of a section.
2340 do_section_size(unsigned int shndx)
2341 { return this->elf_file_.section_size(shndx); }
2343 // Get the name of a section.
2345 do_section_name(unsigned int shndx) const
2346 { return this->elf_file_.section_name(shndx); }
2348 // Return the location of the contents of a section.
2349 const unsigned char*
2350 do_section_contents(unsigned int shndx, section_size_type* plen,
2353 Object::Location loc(this->elf_file_.section_contents(shndx));
2354 *plen = convert_to_section_size_type(loc.data_size);
2357 static const unsigned char empty[1] = { '\0' };
2360 return this->get_view(loc.file_offset, *plen, true, cache);
2363 // Return section flags.
2365 do_section_flags(unsigned int shndx);
2367 // Return section entsize.
2369 do_section_entsize(unsigned int shndx);
2371 // Return section address.
2373 do_section_address(unsigned int shndx)
2374 { return this->elf_file_.section_addr(shndx); }
2376 // Return section type.
2378 do_section_type(unsigned int shndx)
2379 { return this->elf_file_.section_type(shndx); }
2381 // Return the section link field.
2383 do_section_link(unsigned int shndx)
2384 { return this->elf_file_.section_link(shndx); }
2386 // Return the section info field.
2388 do_section_info(unsigned int shndx)
2389 { return this->elf_file_.section_info(shndx); }
2391 // Return the section alignment.
2393 do_section_addralign(unsigned int shndx)
2394 { return this->elf_file_.section_addralign(shndx); }
2396 // Return the Xindex structure to use.
2398 do_initialize_xindex();
2400 // Get symbol counts.
2402 do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
2404 // Get the global symbols.
2406 do_get_global_symbols() const
2407 { return &this->symbols_; }
2409 // Adjust a section index if necessary.
2411 adjust_shndx(unsigned int shndx)
2413 if (shndx >= elfcpp::SHN_LORESERVE)
2414 shndx += this->elf_file_.large_shndx_offset();
2418 // Initialize input to output maps for section symbols in merged
2421 initialize_input_to_output_maps();
2423 // Free the input to output maps for section symbols in merged
2426 free_input_to_output_maps();
2428 // Return symbol table section index.
2430 symtab_shndx() const
2431 { return this->symtab_shndx_; }
2433 // Allow a child class to access the ELF file.
2434 elfcpp::Elf_file<size, big_endian, Object>*
2436 { return &this->elf_file_; }
2438 // Allow a child class to access the local values.
2441 { return &this->local_values_; }
2443 // Views and sizes when relocating.
2446 unsigned char* view;
2447 typename elfcpp::Elf_types<size>::Elf_Addr address;
2449 section_size_type view_size;
2450 bool is_input_output_view;
2451 bool is_postprocessing_view;
2452 bool is_ctors_reverse_view;
2455 typedef std::vector<View_size> Views;
2457 // Stash away info for a number of special sections.
2458 // Return true if any of the sections found require local symbols to be read.
2460 do_find_special_sections(Read_symbols_data* sd);
2462 // This may be overriden by a child class.
2464 do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
2465 const unsigned char* pshdrs, Output_file* of,
2468 // Adjust this local symbol value. Return false if the symbol
2469 // should be discarded from the output file.
2471 do_adjust_local_symbol(Symbol_value<size>*) const
2474 // Allow a child to set output local symbol count.
2476 set_output_local_symbol_count(unsigned int value)
2477 { this->output_local_symbol_count_ = value; }
2481 typedef Sized_relobj_file<size, big_endian> This;
2482 static const int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
2483 static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
2484 static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2485 typedef elfcpp::Shdr<size, big_endian> Shdr;
2487 // To keep track of discarded comdat sections, we need to map a member
2488 // section index to the object and section index of the corresponding
2490 struct Kept_comdat_section
2492 Kept_comdat_section(Relobj* a_object, unsigned int a_shndx)
2493 : object(a_object), shndx(a_shndx)
2498 typedef std::map<unsigned int, Kept_comdat_section>
2499 Kept_comdat_section_table;
2501 // Find the SHT_SYMTAB section, given the section headers.
2503 find_symtab(const unsigned char* pshdrs);
2505 // Return whether SHDR has the right flags for a GNU style exception
2508 check_eh_frame_flags(const elfcpp::Shdr<size, big_endian>* shdr) const;
2510 // Return whether there is a section named .eh_frame which might be
2511 // a GNU style exception frame section.
2513 find_eh_frame(const unsigned char* pshdrs, const char* names,
2514 section_size_type names_size) const;
2516 // Whether to include a section group in the link.
2518 include_section_group(Symbol_table*, Layout*, unsigned int, const char*,
2519 const unsigned char*, const char*, section_size_type,
2520 std::vector<bool>*);
2522 // Whether to include a linkonce section in the link.
2524 include_linkonce_section(Layout*, unsigned int, const char*,
2525 const elfcpp::Shdr<size, big_endian>&);
2527 // Layout an input section.
2529 layout_section(Layout* layout, unsigned int shndx, const char* name,
2530 const typename This::Shdr& shdr, unsigned int reloc_shndx,
2531 unsigned int reloc_type);
2533 // Layout an input .eh_frame section.
2535 layout_eh_frame_section(Layout* layout, const unsigned char* symbols_data,
2536 section_size_type symbols_size,
2537 const unsigned char* symbol_names_data,
2538 section_size_type symbol_names_size,
2539 unsigned int shndx, const typename This::Shdr&,
2540 unsigned int reloc_shndx, unsigned int reloc_type);
2542 // Write section data to the output file. Record the views and
2543 // sizes in VIEWS for use when relocating.
2545 write_sections(const Layout*, const unsigned char* pshdrs, Output_file*,
2548 // Relocate the sections in the output file.
2550 relocate_sections(const Symbol_table* symtab, const Layout* layout,
2551 const unsigned char* pshdrs, Output_file* of,
2553 { this->do_relocate_sections(symtab, layout, pshdrs, of, pviews); }
2555 // Reverse the words in a section. Used for .ctors sections mapped
2556 // to .init_array sections.
2558 reverse_words(unsigned char*, section_size_type);
2560 // Scan the input relocations for --emit-relocs.
2562 emit_relocs_scan(Symbol_table*, Layout*, const unsigned char* plocal_syms,
2563 const Read_relocs_data::Relocs_list::iterator&);
2565 // Scan the input relocations for --emit-relocs, templatized on the
2566 // type of the relocation section.
2567 template<int sh_type>
2569 emit_relocs_scan_reltype(Symbol_table*, Layout*,
2570 const unsigned char* plocal_syms,
2571 const Read_relocs_data::Relocs_list::iterator&,
2572 Relocatable_relocs*);
2574 // Scan the input relocations for --incremental.
2576 incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator&);
2578 // Scan the input relocations for --incremental, templatized on the
2579 // type of the relocation section.
2580 template<int sh_type>
2582 incremental_relocs_scan_reltype(
2583 const Read_relocs_data::Relocs_list::iterator&);
2586 incremental_relocs_write(const Relocate_info<size, big_endian>*,
2587 unsigned int sh_type,
2588 const unsigned char* prelocs,
2591 Address output_offset,
2594 template<int sh_type>
2596 incremental_relocs_write_reltype(const Relocate_info<size, big_endian>*,
2597 const unsigned char* prelocs,
2600 Address output_offset,
2603 // A type shared by split_stack_adjust_reltype and find_functions.
2604 typedef std::map<section_offset_type, section_size_type> Function_offsets;
2606 // Check for -fsplit-stack routines calling non-split-stack routines.
2608 split_stack_adjust(const Symbol_table*, const unsigned char* pshdrs,
2609 unsigned int sh_type, unsigned int shndx,
2610 const unsigned char* prelocs, size_t reloc_count,
2611 unsigned char* view, section_size_type view_size,
2612 Reloc_symbol_changes** reloc_map);
2614 template<int sh_type>
2616 split_stack_adjust_reltype(const Symbol_table*, const unsigned char* pshdrs,
2617 unsigned int shndx, const unsigned char* prelocs,
2618 size_t reloc_count, unsigned char* view,
2619 section_size_type view_size,
2620 Reloc_symbol_changes** reloc_map);
2622 // Find all functions in a section.
2624 find_functions(const unsigned char* pshdrs, unsigned int shndx,
2627 // Write out the local symbols.
2629 write_local_symbols(Output_file*,
2630 const Stringpool_template<char>*,
2631 const Stringpool_template<char>*,
2632 Output_symtab_xindex*,
2633 Output_symtab_xindex*,
2636 // Record a mapping from discarded section SHNDX to the corresponding
2639 set_kept_comdat_section(unsigned int shndx, Relobj* kept_object,
2640 unsigned int kept_shndx)
2642 Kept_comdat_section kept(kept_object, kept_shndx);
2643 this->kept_comdat_sections_.insert(std::make_pair(shndx, kept));
2646 // Find the kept section corresponding to the discarded section
2647 // SHNDX. Return true if found.
2649 get_kept_comdat_section(unsigned int shndx, Relobj** kept_object,
2650 unsigned int* kept_shndx) const
2652 typename Kept_comdat_section_table::const_iterator p =
2653 this->kept_comdat_sections_.find(shndx);
2654 if (p == this->kept_comdat_sections_.end())
2656 *kept_object = p->second.object;
2657 *kept_shndx = p->second.shndx;
2661 // Compute final local symbol value. R_SYM is the local symbol index.
2662 // LV_IN points to a local symbol value containing the input value.
2663 // LV_OUT points to a local symbol value storing the final output value,
2664 // which must not be a merged symbol value since before calling this
2665 // method to avoid memory leak. RELOCATABLE indicates whether we are
2666 // linking a relocatable output. OUT_SECTIONS is an array of output
2667 // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
2668 // points to a symbol table.
2670 // The method returns a status code at return. If the return status is
2671 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2672 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2673 // *LV_OUT is not modified.
2674 inline Compute_final_local_value_status
2675 compute_final_local_value_internal(unsigned int r_sym,
2676 const Symbol_value<size>* lv_in,
2677 Symbol_value<size>* lv_out,
2679 const Output_sections& out_sections,
2680 const std::vector<Address>& out_offsets,
2681 const Symbol_table* symtab);
2683 // The PLT offsets of local symbols.
2684 typedef Unordered_map<unsigned int, unsigned int> Local_plt_offsets;
2686 // Saved information for sections whose layout was deferred.
2687 struct Deferred_layout
2689 static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
2690 Deferred_layout(unsigned int shndx, const char* name,
2691 const unsigned char* pshdr,
2692 unsigned int reloc_shndx, unsigned int reloc_type)
2693 : shndx_(shndx), name_(name), reloc_shndx_(reloc_shndx),
2694 reloc_type_(reloc_type)
2696 memcpy(this->shdr_data_, pshdr, shdr_size);
2698 unsigned int shndx_;
2700 unsigned int reloc_shndx_;
2701 unsigned int reloc_type_;
2702 unsigned char shdr_data_[shdr_size];
2705 // General access to the ELF file.
2706 elfcpp::Elf_file<size, big_endian, Object> elf_file_;
2707 // Type of ELF file (ET_REL or ET_EXEC). ET_EXEC files are allowed
2708 // as input files only for the --just-symbols option.
2710 // Index of SHT_SYMTAB section.
2711 unsigned int symtab_shndx_;
2712 // The number of local symbols.
2713 unsigned int local_symbol_count_;
2714 // The number of local symbols which go into the output file.
2715 unsigned int output_local_symbol_count_;
2716 // The number of local symbols which go into the output file's dynamic
2718 unsigned int output_local_dynsym_count_;
2719 // The entries in the symbol table for the external symbols.
2721 // Number of symbols defined in object file itself.
2722 size_t defined_count_;
2723 // File offset for local symbols (relative to start of symbol table).
2724 off_t local_symbol_offset_;
2725 // File offset for local dynamic symbols (absolute).
2726 off_t local_dynsym_offset_;
2727 // Values of local symbols.
2728 Local_values local_values_;
2729 // PLT offsets for local symbols.
2730 Local_plt_offsets local_plt_offsets_;
2731 // Table mapping discarded comdat sections to corresponding kept sections.
2732 Kept_comdat_section_table kept_comdat_sections_;
2733 // Whether this object has a GNU style .eh_frame section.
2735 // If this object has a GNU style .eh_frame section that is discarded in
2736 // output, record the index here. Otherwise it is -1U.
2737 unsigned int discarded_eh_frame_shndx_;
2738 // True if the layout of this object was deferred, waiting for plugin
2739 // replacement files.
2740 bool is_deferred_layout_;
2741 // The list of sections whose layout was deferred.
2742 std::vector<Deferred_layout> deferred_layout_;
2743 // The list of relocation sections whose layout was deferred.
2744 std::vector<Deferred_layout> deferred_layout_relocs_;
2747 // A class to manage the list of all objects.
2753 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL)
2756 // The type of the list of input relocateable objects.
2757 typedef std::vector<Relobj*> Relobj_list;
2758 typedef Relobj_list::const_iterator Relobj_iterator;
2760 // The type of the list of input dynamic objects.
2761 typedef std::vector<Dynobj*> Dynobj_list;
2762 typedef Dynobj_list::const_iterator Dynobj_iterator;
2764 // Add an object to the list. Return true if all is well, or false
2765 // if this object should be ignored.
2767 add_object(Object*);
2769 // Start processing an archive.
2771 archive_start(Archive*);
2773 // Stop processing an archive.
2775 archive_stop(Archive*);
2777 // For each dynamic object, check whether we've seen all of its
2778 // explicit dependencies.
2780 check_dynamic_dependencies() const;
2782 // Return whether an object was found in the system library
2785 found_in_system_library_directory(const Object*) const;
2787 // Print symbol counts.
2789 print_symbol_counts(const Symbol_table*) const;
2791 // Print a cross reference table.
2793 print_cref(const Symbol_table*, FILE*) const;
2795 // Iterate over all regular objects.
2798 relobj_begin() const
2799 { return this->relobj_list_.begin(); }
2803 { return this->relobj_list_.end(); }
2805 // Iterate over all dynamic objects.
2808 dynobj_begin() const
2809 { return this->dynobj_list_.begin(); }
2813 { return this->dynobj_list_.end(); }
2815 // Return whether we have seen any dynamic objects.
2818 { return !this->dynobj_list_.empty(); }
2820 // Return the number of non dynamic objects.
2822 number_of_relobjs() const
2823 { return this->relobj_list_.size(); }
2825 // Return the number of input objects.
2827 number_of_input_objects() const
2828 { return this->relobj_list_.size() + this->dynobj_list_.size(); }
2831 Input_objects(const Input_objects&);
2832 Input_objects& operator=(const Input_objects&);
2834 // The list of ordinary objects included in the link.
2835 Relobj_list relobj_list_;
2836 // The list of dynamic objects included in the link.
2837 Dynobj_list dynobj_list_;
2838 // SONAMEs that we have seen.
2839 Unordered_set<std::string> sonames_;
2840 // Manage cross-references if requested.
2844 // Some of the information we pass to the relocation routines. We
2845 // group this together to avoid passing a dozen different arguments.
2847 template<int size, bool big_endian>
2848 struct Relocate_info
2851 const Symbol_table* symtab;
2853 const Layout* layout;
2854 // Object being relocated.
2855 Sized_relobj_file<size, big_endian>* object;
2856 // Section index of relocation section.
2857 unsigned int reloc_shndx;
2858 // Section header of relocation section.
2859 const unsigned char* reloc_shdr;
2860 // Section index of section being relocated.
2861 unsigned int data_shndx;
2862 // Section header of data section.
2863 const unsigned char* data_shdr;
2865 // Return a string showing the location of a relocation. This is
2866 // only used for error messages.
2868 location(size_t relnum, off_t reloffset) const;
2871 // This is used to represent a section in an object and is used as the
2872 // key type for various section maps.
2873 typedef std::pair<Relobj*, unsigned int> Section_id;
2875 // This is similar to Section_id but is used when the section
2876 // pointers are const.
2877 typedef std::pair<const Relobj*, unsigned int> Const_section_id;
2879 // The hash value is based on the address of an object in memory during
2880 // linking. It is okay to use this for looking up sections but never use
2881 // this in an unordered container that we want to traverse in a repeatable
2884 struct Section_id_hash
2886 size_t operator()(const Section_id& loc) const
2887 { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
2890 struct Const_section_id_hash
2892 size_t operator()(const Const_section_id& loc) const
2893 { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
2896 // Return whether INPUT_FILE contains an ELF object start at file
2897 // offset OFFSET. This sets *START to point to a view of the start of
2898 // the file. It sets *READ_SIZE to the number of bytes in the view.
2901 is_elf_object(Input_file* input_file, off_t offset,
2902 const unsigned char** start, int* read_size);
2904 // Return an Object appropriate for the input file. P is BYTES long,
2905 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2906 // this sees an object the linker is not configured to support, it
2907 // sets *PUNCONFIGURED to true and returns NULL without giving an
2911 make_elf_object(const std::string& name, Input_file*,
2912 off_t offset, const unsigned char* p,
2913 section_offset_type bytes, bool* punconfigured);
2915 } // end namespace gold
2917 #endif // !defined(GOLD_OBJECT_H)