1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010 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_symtab_xindex
;
47 class Object_merge_map
;
48 class Relocatable_relocs
;
51 template<typename Stringpool_char
>
52 class Stringpool_template
;
54 // Data to pass from read_symbols() to add_symbols().
56 struct Read_symbols_data
59 File_view
* section_headers
;
61 File_view
* section_names
;
62 // Size of section name data in bytes.
63 section_size_type section_names_size
;
66 // Size of symbol data in bytes.
67 section_size_type symbols_size
;
68 // Offset of external symbols within symbol data. This structure
69 // sometimes contains only external symbols, in which case this will
70 // be zero. Sometimes it contains all symbols.
71 section_offset_type external_symbols_offset
;
73 File_view
* symbol_names
;
74 // Size of symbol name data in bytes.
75 section_size_type symbol_names_size
;
77 // Version information. This is only used on dynamic objects.
78 // Version symbol data (from SHT_GNU_versym section).
80 section_size_type versym_size
;
81 // Version definition data (from SHT_GNU_verdef section).
83 section_size_type verdef_size
;
84 unsigned int verdef_info
;
85 // Needed version data (from SHT_GNU_verneed section).
87 section_size_type verneed_size
;
88 unsigned int verneed_info
;
91 // Information used to print error messages.
93 struct Symbol_location_info
95 std::string source_file
;
96 std::string enclosing_symbol_name
;
100 // Data about a single relocation section. This is read in
101 // read_relocs and processed in scan_relocs.
103 struct Section_relocs
105 // Index of reloc section.
106 unsigned int reloc_shndx
;
107 // Index of section that relocs apply to.
108 unsigned int data_shndx
;
109 // Contents of reloc section.
111 // Reloc section type.
112 unsigned int sh_type
;
113 // Number of reloc entries.
116 Output_section
* output_section
;
117 // Whether this section has special handling for offsets.
118 bool needs_special_offset_handling
;
119 // Whether the data section is allocated (has the SHF_ALLOC flag set).
120 bool is_data_section_allocated
;
123 // Relocations in an object file. This is read in read_relocs and
124 // processed in scan_relocs.
126 struct Read_relocs_data
128 typedef std::vector
<Section_relocs
> Relocs_list
;
131 // The local symbols.
132 File_view
* local_symbols
;
135 // The Xindex class manages section indexes for objects with more than
141 Xindex(int large_shndx_offset
)
142 : large_shndx_offset_(large_shndx_offset
), symtab_xindex_()
145 // Initialize the symtab_xindex_ array, given the object and the
146 // section index of the symbol table to use.
147 template<int size
, bool big_endian
>
149 initialize_symtab_xindex(Object
*, unsigned int symtab_shndx
);
151 // Read in the symtab_xindex_ array, given its section index.
152 // PSHDRS may optionally point to the section headers.
153 template<int size
, bool big_endian
>
155 read_symtab_xindex(Object
*, unsigned int xindex_shndx
,
156 const unsigned char* pshdrs
);
158 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
159 // real section index.
161 sym_xindex_to_shndx(Object
* object
, unsigned int symndx
);
164 // The type of the array giving the real section index for symbols
165 // whose st_shndx field holds SHN_XINDEX.
166 typedef std::vector
<unsigned int> Symtab_xindex
;
168 // Adjust a section index if necessary. This should only be called
169 // for ordinary section indexes.
171 adjust_shndx(unsigned int shndx
)
173 if (shndx
>= elfcpp::SHN_LORESERVE
)
174 shndx
+= this->large_shndx_offset_
;
178 // Adjust to apply to large section indexes.
179 int large_shndx_offset_
;
180 // The data from the SHT_SYMTAB_SHNDX section.
181 Symtab_xindex symtab_xindex_
;
184 // Object is an abstract base class which represents either a 32-bit
185 // or a 64-bit input object. This can be a regular object file
186 // (ET_REL) or a shared object (ET_DYN).
191 typedef std::vector
<Symbol
*> Symbols
;
193 // NAME is the name of the object as we would report it to the user
194 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
195 // used to read the file. OFFSET is the offset within the input
196 // file--0 for a .o or .so file, something else for a .a file.
197 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
199 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
200 is_dynamic_(is_dynamic
), is_needed_(false), uses_split_stack_(false),
201 has_no_split_stack_(false), no_export_(false), xindex_(NULL
)
202 { input_file
->file().add_object(); }
205 { this->input_file_
->file().remove_object(); }
207 // Return the name of the object as we would report it to the tuser.
210 { return this->name_
; }
212 // Get the offset into the file.
215 { return this->offset_
; }
217 // Return whether this is a dynamic object.
220 { return this->is_dynamic_
; }
222 // Return whether this object is needed--true if it is a dynamic
223 // object which defines some symbol referenced by a regular object.
224 // We keep the flag here rather than in Dynobj for convenience when
228 { return this->is_needed_
; }
230 // Record that this object is needed.
233 { this->is_needed_
= true; }
235 // Return whether this object was compiled with -fsplit-stack.
237 uses_split_stack() const
238 { return this->uses_split_stack_
; }
240 // Return whether this object contains any functions compiled with
241 // the no_split_stack attribute.
243 has_no_split_stack() const
244 { return this->has_no_split_stack_
; }
246 // Returns NULL for Objects that are not plugin objects. This method
247 // is overridden in the Pluginobj class.
250 { return this->do_pluginobj(); }
252 // Get the file. We pass on const-ness.
255 { return this->input_file_
; }
259 { return this->input_file_
; }
261 // Lock the underlying file.
264 { this->input_file()->file().lock(t
); }
266 // Unlock the underlying file.
268 unlock(const Task
* t
)
269 { this->input_file()->file().unlock(t
); }
271 // Return whether the underlying file is locked.
274 { return this->input_file()->file().is_locked(); }
276 // Return the token, so that the task can be queued.
279 { return this->input_file()->file().token(); }
281 // Release the underlying file.
284 { this->input_file_
->file().release(); }
286 // Return whether we should just read symbols from this file.
289 { return this->input_file()->just_symbols(); }
291 // Get the number of sections.
294 { return this->shnum_
; }
296 // Return a view of the contents of a section. Set *PLEN to the
297 // size. CACHE is a hint as in File_read::get_view.
299 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
301 // Adjust a symbol's section index as needed. SYMNDX is the index
302 // of the symbol and SHNDX is the symbol's section from
303 // get_st_shndx. This returns the section index. It sets
304 // *IS_ORDINARY to indicate whether this is a normal section index,
305 // rather than a special code between SHN_LORESERVE and
308 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
310 if (shndx
< elfcpp::SHN_LORESERVE
)
312 else if (shndx
== elfcpp::SHN_XINDEX
)
314 if (this->xindex_
== NULL
)
315 this->xindex_
= this->do_initialize_xindex();
316 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
320 *is_ordinary
= false;
324 // Return the size of a section given a section index.
326 section_size(unsigned int shndx
)
327 { return this->do_section_size(shndx
); }
329 // Return the name of a section given a section index.
331 section_name(unsigned int shndx
)
332 { return this->do_section_name(shndx
); }
334 // Return the section flags given a section index.
336 section_flags(unsigned int shndx
)
337 { return this->do_section_flags(shndx
); }
339 // Return the section entsize given a section index.
341 section_entsize(unsigned int shndx
)
342 { return this->do_section_entsize(shndx
); }
344 // Return the section address given a section index.
346 section_address(unsigned int shndx
)
347 { return this->do_section_address(shndx
); }
349 // Return the section type given a section index.
351 section_type(unsigned int shndx
)
352 { return this->do_section_type(shndx
); }
354 // Return the section link field given a section index.
356 section_link(unsigned int shndx
)
357 { return this->do_section_link(shndx
); }
359 // Return the section info field given a section index.
361 section_info(unsigned int shndx
)
362 { return this->do_section_info(shndx
); }
364 // Return the required section alignment given a section index.
366 section_addralign(unsigned int shndx
)
367 { return this->do_section_addralign(shndx
); }
369 // Read the symbol information.
371 read_symbols(Read_symbols_data
* sd
)
372 { return this->do_read_symbols(sd
); }
374 // Pass sections which should be included in the link to the Layout
375 // object, and record where the sections go in the output file.
377 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
378 { this->do_layout(symtab
, layout
, sd
); }
380 // Add symbol information to the global symbol table.
382 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
383 { this->do_add_symbols(symtab
, sd
, layout
); }
385 // Add symbol information to the global symbol table.
386 Archive::Should_include
387 should_include_member(Symbol_table
* symtab
, Read_symbols_data
* sd
,
389 { return this->do_should_include_member(symtab
, sd
, why
); }
391 // Functions and types for the elfcpp::Elf_file interface. This
392 // permit us to use Object as the File template parameter for
395 // The View class is returned by view. It must support a single
396 // method, data(). This is trivial, because get_view does what we
401 View(const unsigned char* p
)
410 const unsigned char* p_
;
415 view(off_t file_offset
, section_size_type data_size
)
416 { return View(this->get_view(file_offset
, data_size
, true, true)); }
420 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
422 // A location in the file.
428 Location(off_t fo
, section_size_type ds
)
429 : file_offset(fo
), data_size(ds
)
433 // Get a View given a Location.
434 View
view(Location loc
)
435 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
437 // Get a view into the underlying file.
439 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
441 return this->input_file()->file().get_view(this->offset_
, start
, size
,
445 // Get a lasting view into the underlying file.
447 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
450 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
451 size
, aligned
, cache
);
454 // Read data from the underlying file.
456 read(off_t start
, section_size_type size
, void* p
)
457 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
459 // Read multiple data from the underlying file.
461 read_multiple(const File_read::Read_multiple
& rm
)
462 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
464 // Stop caching views in the underlying file.
466 clear_view_cache_marks()
467 { this->input_file()->file().clear_view_cache_marks(); }
469 // Get the number of global symbols defined by this object, and the
470 // number of the symbols whose final definition came from this
473 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
475 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
477 // Get the symbols defined in this object.
479 get_global_symbols() const
480 { return this->do_get_global_symbols(); }
482 // Return whether this object was found in a system directory.
484 is_in_system_directory() const
485 { return this->input_file()->is_in_system_directory(); }
487 // Return whether we found this object by searching a directory.
490 { return this->input_file()->will_search_for(); }
494 { return this->no_export_
; }
497 set_no_export(bool value
)
498 { this->no_export_
= value
; }
501 // Returns NULL for Objects that are not plugin objects. This method
502 // is overridden in the Pluginobj class.
507 // Read the symbols--implemented by child class.
509 do_read_symbols(Read_symbols_data
*) = 0;
511 // Lay out sections--implemented by child class.
513 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
515 // Add symbol information to the global symbol table--implemented by
518 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
520 virtual Archive::Should_include
521 do_should_include_member(Symbol_table
* symtab
, Read_symbols_data
*,
522 std::string
* why
) = 0;
524 // Return the location of the contents of a section. Implemented by
527 do_section_contents(unsigned int shndx
) = 0;
529 // Get the size of a section--implemented by child class.
531 do_section_size(unsigned int shndx
) = 0;
533 // Get the name of a section--implemented by child class.
535 do_section_name(unsigned int shndx
) = 0;
537 // Get section flags--implemented by child class.
539 do_section_flags(unsigned int shndx
) = 0;
541 // Get section entsize--implemented by child class.
543 do_section_entsize(unsigned int shndx
) = 0;
545 // Get section address--implemented by child class.
547 do_section_address(unsigned int shndx
) = 0;
549 // Get section type--implemented by child class.
551 do_section_type(unsigned int shndx
) = 0;
553 // Get section link field--implemented by child class.
555 do_section_link(unsigned int shndx
) = 0;
557 // Get section info field--implemented by child class.
559 do_section_info(unsigned int shndx
) = 0;
561 // Get section alignment--implemented by child class.
563 do_section_addralign(unsigned int shndx
) = 0;
565 // Return the Xindex structure to use.
567 do_initialize_xindex() = 0;
569 // Implement get_global_symbol_counts--implemented by child class.
571 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
573 virtual const Symbols
*
574 do_get_global_symbols() const = 0;
576 // Set the number of sections.
579 { this->shnum_
= shnum
; }
581 // Functions used by both Sized_relobj and Sized_dynobj.
583 // Read the section data into a Read_symbols_data object.
584 template<int size
, bool big_endian
>
586 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
589 // Let the child class initialize the xindex object directly.
591 set_xindex(Xindex
* xindex
)
593 gold_assert(this->xindex_
== NULL
);
594 this->xindex_
= xindex
;
597 // If NAME is the name of a special .gnu.warning section, arrange
598 // for the warning to be issued. SHNDX is the section index.
599 // Return whether it is a warning section.
601 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
604 // If NAME is the name of the special section which indicates that
605 // this object was compiled with -fstack-split, mark it accordingly,
606 // and return true. Otherwise return false.
608 handle_split_stack_section(const char* name
);
611 // This class may not be copied.
612 Object(const Object
&);
613 Object
& operator=(const Object
&);
615 // Name of object as printed to user.
617 // For reading the file.
618 Input_file
* input_file_
;
619 // Offset within the file--0 for an object file, non-0 for an
622 // Number of input sections.
624 // Whether this is a dynamic object.
625 bool is_dynamic_
: 1;
626 // Whether this object is needed. This is only set for dynamic
627 // objects, and means that the object defined a symbol which was
628 // used by a reference from a regular object.
630 // Whether this object was compiled with -fsplit-stack.
631 bool uses_split_stack_
: 1;
632 // Whether this object contains any functions compiled with the
633 // no_split_stack attribute.
634 bool has_no_split_stack_
: 1;
635 // True if exclude this object from automatic symbol export.
636 // This is used only for archive objects.
638 // Many sections for objects with more than SHN_LORESERVE sections.
642 // A regular object (ET_REL). This is an abstract base class itself.
643 // The implementation is the template class Sized_relobj.
645 class Relobj
: public Object
648 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
649 : Object(name
, input_file
, false, offset
),
651 map_to_relocatable_relocs_(NULL
),
652 object_merge_map_(NULL
),
653 relocs_must_follow_section_writes_(false),
657 // During garbage collection, the Read_symbols_data pass for
658 // each object is stored as layout needs to be done after
662 { return this->sd_
; }
664 // Decides which section names have to be included in the worklist
667 is_section_name_included(const char *name
);
670 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
671 unsigned int section_header_size
);
674 set_symbols_data(Symbols_data
* sd
)
677 // During garbage collection, the Read_relocs pass for all objects
678 // is done before scanning the relocs. In that case, this->rd_ is
679 // used to store the information from Read_relocs for each object.
680 // This data is also used to compute the list of relevant sections.
683 { return this->rd_
; }
686 set_relocs_data(Read_relocs_data
* rd
)
690 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
694 read_relocs(Read_relocs_data
* rd
)
695 { return this->do_read_relocs(rd
); }
697 // Process the relocs, during garbage collection only.
699 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
700 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
702 // Scan the relocs and adjust the symbol table.
704 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
705 { return this->do_scan_relocs(symtab
, layout
, rd
); }
707 // The number of local symbols in the input symbol table.
709 local_symbol_count() const
710 { return this->do_local_symbol_count(); }
712 // Initial local symbol processing: count the number of local symbols
713 // in the output symbol table and dynamic symbol table; add local symbol
714 // names to *POOL and *DYNPOOL.
716 count_local_symbols(Stringpool_template
<char>* pool
,
717 Stringpool_template
<char>* dynpool
)
718 { return this->do_count_local_symbols(pool
, dynpool
); }
720 // Set the values of the local symbols, set the output symbol table
721 // indexes for the local variables, and set the offset where local
722 // symbol information will be stored. Returns the new local symbol index.
724 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
725 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
727 // Set the output dynamic symbol table indexes for the local variables.
729 set_local_dynsym_indexes(unsigned int index
)
730 { return this->do_set_local_dynsym_indexes(index
); }
732 // Set the offset where local dynamic symbol information will be stored.
734 set_local_dynsym_offset(off_t off
)
735 { return this->do_set_local_dynsym_offset(off
); }
737 // Relocate the input sections and write out the local symbols.
739 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
740 { return this->do_relocate(symtab
, layout
, of
); }
742 // Return whether an input section is being included in the link.
744 is_section_included(unsigned int shndx
) const
746 gold_assert(shndx
< this->output_sections_
.size());
747 return this->output_sections_
[shndx
] != NULL
;
750 // Given a section index, return the corresponding Output_section.
751 // The return value will be NULL if the section is not included in
754 output_section(unsigned int shndx
) const
756 gold_assert(shndx
< this->output_sections_
.size());
757 return this->output_sections_
[shndx
];
760 // The the output section of the input section with index SHNDX.
761 // This is only used currently to remove a section from the link in
764 set_output_section(unsigned int shndx
, Output_section
* os
)
766 gold_assert(shndx
< this->output_sections_
.size());
767 this->output_sections_
[shndx
] = os
;
770 // Given a section index, return the offset in the Output_section.
771 // The return value will be -1U if the section is specially mapped,
772 // such as a merge section.
774 output_section_offset(unsigned int shndx
) const
775 { return this->do_output_section_offset(shndx
); }
777 // Set the offset of an input section within its output section.
779 set_section_offset(unsigned int shndx
, uint64_t off
)
780 { this->do_set_section_offset(shndx
, off
); }
782 // Return true if we need to wait for output sections to be written
783 // before we can apply relocations. This is true if the object has
784 // any relocations for sections which require special handling, such
785 // as the exception frame section.
787 relocs_must_follow_section_writes() const
788 { return this->relocs_must_follow_section_writes_
; }
790 // Return the object merge map.
793 { return this->object_merge_map_
; }
795 // Set the object merge map.
797 set_merge_map(Object_merge_map
* object_merge_map
)
799 gold_assert(this->object_merge_map_
== NULL
);
800 this->object_merge_map_
= object_merge_map
;
803 // Record the relocatable reloc info for an input reloc section.
805 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
807 gold_assert(reloc_shndx
< this->shnum());
808 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
811 // Get the relocatable reloc info for an input reloc section.
813 relocatable_relocs(unsigned int reloc_shndx
)
815 gold_assert(reloc_shndx
< this->shnum());
816 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
819 // Layout sections whose layout was deferred while waiting for
820 // input files from a plugin.
822 layout_deferred_sections(Layout
* layout
)
823 { this->do_layout_deferred_sections(layout
); }
826 // The output section to be used for each input section, indexed by
827 // the input section number. The output section is NULL if the
828 // input section is to be discarded.
829 typedef std::vector
<Output_section
*> Output_sections
;
831 // Read the relocs--implemented by child class.
833 do_read_relocs(Read_relocs_data
*) = 0;
835 // Process the relocs--implemented by child class.
837 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
839 // Scan the relocs--implemented by child class.
841 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
843 // Return the number of local symbols--implemented by child class.
845 do_local_symbol_count() const = 0;
847 // Count local symbols--implemented by child class.
849 do_count_local_symbols(Stringpool_template
<char>*,
850 Stringpool_template
<char>*) = 0;
852 // Finalize the local symbols. Set the output symbol table indexes
853 // for the local variables, and set the offset where local symbol
854 // information will be stored.
856 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
858 // Set the output dynamic symbol table indexes for the local variables.
860 do_set_local_dynsym_indexes(unsigned int) = 0;
862 // Set the offset where local dynamic symbol information will be stored.
864 do_set_local_dynsym_offset(off_t
) = 0;
866 // Relocate the input sections and write out the local
867 // symbols--implemented by child class.
869 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
871 // Get the offset of a section--implemented by child class.
873 do_output_section_offset(unsigned int shndx
) const = 0;
875 // Set the offset of a section--implemented by child class.
877 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
879 // Layout sections whose layout was deferred while waiting for
880 // input files from a plugin--implemented by child class.
882 do_layout_deferred_sections(Layout
*) = 0;
884 // Return the vector mapping input sections to output sections.
887 { return this->output_sections_
; }
889 const Output_sections
&
890 output_sections() const
891 { return this->output_sections_
; }
893 // Set the size of the relocatable relocs array.
895 size_relocatable_relocs()
897 this->map_to_relocatable_relocs_
=
898 new std::vector
<Relocatable_relocs
*>(this->shnum());
901 // Record that we must wait for the output sections to be written
902 // before applying relocations.
904 set_relocs_must_follow_section_writes()
905 { this->relocs_must_follow_section_writes_
= true; }
908 // Mapping from input sections to output section.
909 Output_sections output_sections_
;
910 // Mapping from input section index to the information recorded for
911 // the relocations. This is only used for a relocatable link.
912 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
913 // Mappings for merge sections. This is managed by the code in the
915 Object_merge_map
* object_merge_map_
;
916 // Whether we need to wait for output sections to be written before
917 // we can apply relocations.
918 bool relocs_must_follow_section_writes_
;
919 // Used to store the relocs data computed by the Read_relocs pass.
920 // Used during garbage collection of unused sections.
921 Read_relocs_data
* rd_
;
922 // Used to store the symbols data computed by the Read_symbols pass.
923 // Again used during garbage collection when laying out referenced
925 gold::Symbols_data
*sd_
;
928 // This class is used to handle relocations against a section symbol
929 // in an SHF_MERGE section. For such a symbol, we need to know the
930 // addend of the relocation before we can determine the final value.
931 // The addend gives us the location in the input section, and we can
932 // determine how it is mapped to the output section. For a
933 // non-section symbol, we apply the addend to the final value of the
934 // symbol; that is done in finalize_local_symbols, and does not use
938 class Merged_symbol_value
941 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
943 // We use a hash table to map offsets in the input section to output
945 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
947 Merged_symbol_value(Value input_value
, Value output_start_address
)
948 : input_value_(input_value
), output_start_address_(output_start_address
),
952 // Initialize the hash table.
954 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
956 // Release the hash table to save space.
958 free_input_to_output_map()
959 { this->output_addresses_
.clear(); }
961 // Get the output value corresponding to an addend. The object and
962 // input section index are passed in because the caller will have
963 // them; otherwise we could store them here.
965 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
967 // This is a relocation against a section symbol. ADDEND is the
968 // offset in the section. The result should be the start of some
969 // merge area. If the object file wants something else, it should
970 // use a regular symbol rather than a section symbol.
971 // Unfortunately, PR 6658 shows a case in which the object file
972 // refers to the section symbol, but uses a negative ADDEND to
973 // compensate for a PC relative reloc. We can't handle the
974 // general case. However, we can handle the special case of a
975 // negative addend, by assuming that it refers to the start of the
976 // section. Of course, that means that we have to guess when
977 // ADDEND is negative. It is normal to see a 32-bit value here
978 // even when the template parameter size is 64, as 64-bit object
979 // file formats have 32-bit relocations. We know this is a merge
980 // section, so we know it has to fit into memory. So we assume
981 // that we won't see a value larger than a large 32-bit unsigned
982 // value. This will break objects with very very large merge
983 // sections; they probably break in other ways anyhow.
984 Value input_offset
= this->input_value_
;
985 if (addend
< 0xffffff00)
987 input_offset
+= addend
;
990 typename
Output_addresses::const_iterator p
=
991 this->output_addresses_
.find(input_offset
);
992 if (p
!= this->output_addresses_
.end())
993 return p
->second
+ addend
;
995 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
1000 // Get the output value for an input offset if we couldn't find it
1001 // in the hash table.
1003 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
1004 Value input_offset
) const;
1006 // The value of the section symbol in the input file. This is
1007 // normally zero, but could in principle be something else.
1009 // The start address of this merged section in the output file.
1010 Value output_start_address_
;
1011 // A hash table which maps offsets in the input section to output
1012 // addresses. This only maps specific offsets, not all offsets.
1013 Output_addresses output_addresses_
;
1016 // This POD class is holds the value of a symbol. This is used for
1017 // local symbols, and for all symbols during relocation processing.
1018 // For special sections, such as SHF_MERGE sections, this calls a
1019 // function to get the final symbol value.
1025 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1028 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1029 is_ordinary_shndx_(false), is_section_symbol_(false),
1030 is_tls_symbol_(false), has_output_value_(true)
1031 { this->u_
.value
= 0; }
1033 // Get the value of this symbol. OBJECT is the object in which this
1034 // symbol is defined, and ADDEND is an addend to add to the value.
1035 template<bool big_endian
>
1037 value(const Sized_relobj
<size
, big_endian
>* object
, Value addend
) const
1039 if (this->has_output_value_
)
1040 return this->u_
.value
+ addend
;
1043 gold_assert(this->is_ordinary_shndx_
);
1044 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1049 // Set the value of this symbol in the output symbol table.
1051 set_output_value(Value value
)
1052 { this->u_
.value
= value
; }
1054 // For a section symbol in a merged section, we need more
1057 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1059 gold_assert(this->is_section_symbol_
);
1060 this->has_output_value_
= false;
1061 this->u_
.merged_symbol_value
= msv
;
1064 // Initialize the input to output map for a section symbol in a
1065 // merged section. We also initialize the value of a non-section
1066 // symbol in a merged section.
1068 initialize_input_to_output_map(const Relobj
* object
)
1070 if (!this->has_output_value_
)
1072 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1073 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1074 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1078 // Free the input to output map for a section symbol in a merged
1081 free_input_to_output_map()
1083 if (!this->has_output_value_
)
1084 this->u_
.merged_symbol_value
->free_input_to_output_map();
1087 // Set the value of the symbol from the input file. This is only
1088 // called by count_local_symbols, to communicate the value to
1089 // finalize_local_symbols.
1091 set_input_value(Value value
)
1092 { this->u_
.value
= value
; }
1094 // Return the input value. This is only called by
1095 // finalize_local_symbols and (in special cases) relocate_section.
1098 { return this->u_
.value
; }
1100 // Return whether we have set the index in the output symbol table
1103 is_output_symtab_index_set() const
1105 return (this->output_symtab_index_
!= 0
1106 && this->output_symtab_index_
!= -2U);
1109 // Return whether this symbol may be discarded from the normal
1112 may_be_discarded_from_output_symtab() const
1114 gold_assert(!this->is_output_symtab_index_set());
1115 return this->output_symtab_index_
!= -2U;
1118 // Return whether this symbol has an entry in the output symbol
1121 has_output_symtab_entry() const
1123 gold_assert(this->is_output_symtab_index_set());
1124 return this->output_symtab_index_
!= -1U;
1127 // Return the index in the output symbol table.
1129 output_symtab_index() const
1131 gold_assert(this->is_output_symtab_index_set()
1132 && this->output_symtab_index_
!= -1U);
1133 return this->output_symtab_index_
;
1136 // Set the index in the output symbol table.
1138 set_output_symtab_index(unsigned int i
)
1140 gold_assert(!this->is_output_symtab_index_set());
1141 gold_assert(i
!= 0 && i
!= -1U && i
!= -2U);
1142 this->output_symtab_index_
= i
;
1145 // Record that this symbol should not go into the output symbol
1148 set_no_output_symtab_entry()
1150 gold_assert(this->output_symtab_index_
== 0);
1151 this->output_symtab_index_
= -1U;
1154 // Record that this symbol must go into the output symbol table,
1155 // because it there is a relocation that uses it.
1157 set_must_have_output_symtab_entry()
1159 gold_assert(!this->is_output_symtab_index_set());
1160 this->output_symtab_index_
= -2U;
1163 // Set the index in the output dynamic symbol table.
1165 set_needs_output_dynsym_entry()
1167 gold_assert(!this->is_section_symbol());
1168 this->output_dynsym_index_
= 0;
1171 // Return whether this symbol should go into the dynamic symbol
1174 needs_output_dynsym_entry() const
1176 return this->output_dynsym_index_
!= -1U;
1179 // Return whether this symbol has an entry in the dynamic symbol
1182 has_output_dynsym_entry() const
1184 gold_assert(this->output_dynsym_index_
!= 0);
1185 return this->output_dynsym_index_
!= -1U;
1188 // Record that this symbol should go into the dynamic symbol table.
1190 set_output_dynsym_index(unsigned int i
)
1192 gold_assert(this->output_dynsym_index_
== 0);
1193 gold_assert(i
!= 0 && i
!= -1U);
1194 this->output_dynsym_index_
= i
;
1197 // Return the index in the output dynamic symbol table.
1199 output_dynsym_index() const
1201 gold_assert(this->output_dynsym_index_
!= 0
1202 && this->output_dynsym_index_
!= -1U);
1203 return this->output_dynsym_index_
;
1206 // Set the index of the input section in the input file.
1208 set_input_shndx(unsigned int i
, bool is_ordinary
)
1210 this->input_shndx_
= i
;
1211 // input_shndx_ field is a bitfield, so make sure that the value
1213 gold_assert(this->input_shndx_
== i
);
1214 this->is_ordinary_shndx_
= is_ordinary
;
1217 // Return the index of the input section in the input file.
1219 input_shndx(bool* is_ordinary
) const
1221 *is_ordinary
= this->is_ordinary_shndx_
;
1222 return this->input_shndx_
;
1225 // Whether this is a section symbol.
1227 is_section_symbol() const
1228 { return this->is_section_symbol_
; }
1230 // Record that this is a section symbol.
1232 set_is_section_symbol()
1234 gold_assert(!this->needs_output_dynsym_entry());
1235 this->is_section_symbol_
= true;
1238 // Record that this is a TLS symbol.
1241 { this->is_tls_symbol_
= true; }
1243 // Return TRUE if this is a TLS symbol.
1245 is_tls_symbol() const
1246 { return this->is_tls_symbol_
; }
1249 // The index of this local symbol in the output symbol table. This
1250 // will be 0 if no value has been assigned yet, and the symbol may
1251 // be omitted. This will be -1U if the symbol should not go into
1252 // the symbol table. This will be -2U if the symbol must go into
1253 // the symbol table, but no index has been assigned yet.
1254 unsigned int output_symtab_index_
;
1255 // The index of this local symbol in the dynamic symbol table. This
1256 // will be -1U if the symbol should not go into the symbol table.
1257 unsigned int output_dynsym_index_
;
1258 // The section index in the input file in which this symbol is
1260 unsigned int input_shndx_
: 28;
1261 // Whether the section index is an ordinary index, not a special
1263 bool is_ordinary_shndx_
: 1;
1264 // Whether this is a STT_SECTION symbol.
1265 bool is_section_symbol_
: 1;
1266 // Whether this is a STT_TLS symbol.
1267 bool is_tls_symbol_
: 1;
1268 // Whether this symbol has a value for the output file. This is
1269 // normally set to true during Layout::finalize, by
1270 // finalize_local_symbols. It will be false for a section symbol in
1271 // a merge section, as for such symbols we can not determine the
1272 // value to use in a relocation until we see the addend.
1273 bool has_output_value_
: 1;
1276 // This is used if has_output_value_ is true. Between
1277 // count_local_symbols and finalize_local_symbols, this is the
1278 // value in the input file. After finalize_local_symbols, it is
1279 // the value in the output file.
1281 // This is used if has_output_value_ is false. It points to the
1282 // information we need to get the value for a merge section.
1283 Merged_symbol_value
<size
>* merged_symbol_value
;
1287 // A GOT offset list. A symbol may have more than one GOT offset
1288 // (e.g., when mixing modules compiled with two different TLS models),
1289 // but will usually have at most one. GOT_TYPE identifies the type of
1290 // GOT entry; its values are specific to each target.
1292 class Got_offset_list
1296 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
1299 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
1300 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
1305 if (this->got_next_
!= NULL
)
1307 delete this->got_next_
;
1308 this->got_next_
= NULL
;
1312 // Initialize the fields to their default values.
1316 this->got_type_
= -1U;
1317 this->got_offset_
= 0;
1318 this->got_next_
= NULL
;
1321 // Set the offset for the GOT entry of type GOT_TYPE.
1323 set_offset(unsigned int got_type
, unsigned int got_offset
)
1325 if (this->got_type_
== -1U)
1327 this->got_type_
= got_type
;
1328 this->got_offset_
= got_offset
;
1332 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1334 if (g
->got_type_
== got_type
)
1336 g
->got_offset_
= got_offset
;
1340 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1341 g
->got_next_
= this->got_next_
;
1342 this->got_next_
= g
;
1346 // Return the offset for a GOT entry of type GOT_TYPE.
1348 get_offset(unsigned int got_type
) const
1350 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1352 if (g
->got_type_
== got_type
)
1353 return g
->got_offset_
;
1359 unsigned int got_type_
;
1360 unsigned int got_offset_
;
1361 Got_offset_list
* got_next_
;
1364 // This type is used to modify relocations for -fsplit-stack. It is
1365 // indexed by relocation index, and means that the relocation at that
1366 // index should use the symbol from the vector, rather than the one
1367 // indicated by the relocation.
1369 class Reloc_symbol_changes
1372 Reloc_symbol_changes(size_t count
)
1377 set(size_t i
, Symbol
* sym
)
1378 { this->vec_
[i
] = sym
; }
1381 operator[](size_t i
) const
1382 { return this->vec_
[i
]; }
1385 std::vector
<Symbol
*> vec_
;
1388 // A regular object file. This is size and endian specific.
1390 template<int size
, bool big_endian
>
1391 class Sized_relobj
: public Relobj
1394 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1395 typedef std::vector
<Symbol
*> Symbols
;
1396 typedef std::vector
<Symbol_value
<size
> > Local_values
;
1398 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1400 Sized_relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
,
1401 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
1405 // Checks if the offset of input section SHNDX within its output
1406 // section is invalid.
1408 is_output_section_offset_invalid(unsigned int shndx
) const
1409 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1411 // Set up the object file based on TARGET.
1414 { this->do_setup(); }
1416 // Return the number of symbols. This is only valid after
1417 // Object::add_symbols has been called.
1419 symbol_count() const
1420 { return this->local_symbol_count_
+ this->symbols_
.size(); }
1422 // If SYM is the index of a global symbol in the object file's
1423 // symbol table, return the Symbol object. Otherwise, return NULL.
1425 global_symbol(unsigned int sym
) const
1427 if (sym
>= this->local_symbol_count_
)
1429 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
1430 return this->symbols_
[sym
- this->local_symbol_count_
];
1435 // Return the section index of symbol SYM. Set *VALUE to its value
1436 // in the object file. Set *IS_ORDINARY if this is an ordinary
1437 // section index, not a special code between SHN_LORESERVE and
1438 // SHN_HIRESERVE. Note that for a symbol which is not defined in
1439 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
1440 // it will not return the final value of the symbol in the link.
1442 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
1444 // Return a pointer to the Symbol_value structure which holds the
1445 // value of a local symbol.
1446 const Symbol_value
<size
>*
1447 local_symbol(unsigned int sym
) const
1449 gold_assert(sym
< this->local_values_
.size());
1450 return &this->local_values_
[sym
];
1453 // Return the index of local symbol SYM in the ordinary symbol
1454 // table. A value of -1U means that the symbol is not being output.
1456 symtab_index(unsigned int sym
) const
1458 gold_assert(sym
< this->local_values_
.size());
1459 return this->local_values_
[sym
].output_symtab_index();
1462 // Return the index of local symbol SYM in the dynamic symbol
1463 // table. A value of -1U means that the symbol is not being output.
1465 dynsym_index(unsigned int sym
) const
1467 gold_assert(sym
< this->local_values_
.size());
1468 return this->local_values_
[sym
].output_dynsym_index();
1471 // Return the input section index of local symbol SYM.
1473 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
1475 gold_assert(sym
< this->local_values_
.size());
1476 return this->local_values_
[sym
].input_shndx(is_ordinary
);
1479 // Record that local symbol SYM must be in the output symbol table.
1481 set_must_have_output_symtab_entry(unsigned int sym
)
1483 gold_assert(sym
< this->local_values_
.size());
1484 this->local_values_
[sym
].set_must_have_output_symtab_entry();
1487 // Record that local symbol SYM needs a dynamic symbol entry.
1489 set_needs_output_dynsym_entry(unsigned int sym
)
1491 gold_assert(sym
< this->local_values_
.size());
1492 this->local_values_
[sym
].set_needs_output_dynsym_entry();
1495 // Return whether the local symbol SYMNDX has a GOT offset.
1496 // For TLS symbols, the GOT entry will hold its tp-relative offset.
1498 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1500 Local_got_offsets::const_iterator p
=
1501 this->local_got_offsets_
.find(symndx
);
1502 return (p
!= this->local_got_offsets_
.end()
1503 && p
->second
->get_offset(got_type
) != -1U);
1506 // Return the GOT offset of the local symbol SYMNDX.
1508 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1510 Local_got_offsets::const_iterator p
=
1511 this->local_got_offsets_
.find(symndx
);
1512 gold_assert(p
!= this->local_got_offsets_
.end());
1513 unsigned int off
= p
->second
->get_offset(got_type
);
1514 gold_assert(off
!= -1U);
1518 // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
1520 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1521 unsigned int got_offset
)
1523 Local_got_offsets::const_iterator p
=
1524 this->local_got_offsets_
.find(symndx
);
1525 if (p
!= this->local_got_offsets_
.end())
1526 p
->second
->set_offset(got_type
, got_offset
);
1529 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1530 std::pair
<Local_got_offsets::iterator
, bool> ins
=
1531 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
1532 gold_assert(ins
.second
);
1536 // Get the offset of input section SHNDX within its output section.
1537 // This is -1 if the input section requires a special mapping, such
1538 // as a merge section. The output section can be found in the
1539 // output_sections_ field of the parent class Relobj.
1541 get_output_section_offset(unsigned int shndx
) const
1543 gold_assert(shndx
< this->section_offsets_
.size());
1544 return this->section_offsets_
[shndx
];
1547 // Return the name of the symbol that spans the given offset in the
1548 // specified section in this object. This is used only for error
1549 // messages and is not particularly efficient.
1551 get_symbol_location_info(unsigned int shndx
, off_t offset
,
1552 Symbol_location_info
* info
);
1554 // Look for a kept section corresponding to the given discarded section,
1555 // and return its output address. This is used only for relocations in
1556 // debugging sections.
1558 map_to_kept_section(unsigned int shndx
, bool* found
) const;
1565 // Read the symbols.
1567 do_read_symbols(Read_symbols_data
*);
1569 // Return the number of local symbols.
1571 do_local_symbol_count() const
1572 { return this->local_symbol_count_
; }
1574 // Lay out the input sections.
1576 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
1578 // Layout sections whose layout was deferred while waiting for
1579 // input files from a plugin.
1581 do_layout_deferred_sections(Layout
*);
1583 // Add the symbols to the symbol table.
1585 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
1587 Archive::Should_include
1588 do_should_include_member(Symbol_table
* symtab
, Read_symbols_data
*,
1593 do_read_relocs(Read_relocs_data
*);
1595 // Process the relocs to find list of referenced sections. Used only
1596 // during garbage collection.
1598 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1600 // Scan the relocs and adjust the symbol table.
1602 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1604 // Count the local symbols.
1606 do_count_local_symbols(Stringpool_template
<char>*,
1607 Stringpool_template
<char>*);
1609 // Finalize the local symbols.
1611 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
1613 // Set the offset where local dynamic symbol information will be stored.
1615 do_set_local_dynsym_indexes(unsigned int);
1617 // Set the offset where local dynamic symbol information will be stored.
1619 do_set_local_dynsym_offset(off_t
);
1621 // Relocate the input sections and write out the local symbols.
1623 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
1625 // Get the size of a section.
1627 do_section_size(unsigned int shndx
)
1628 { return this->elf_file_
.section_size(shndx
); }
1630 // Get the name of a section.
1632 do_section_name(unsigned int shndx
)
1633 { return this->elf_file_
.section_name(shndx
); }
1635 // Return the location of the contents of a section.
1637 do_section_contents(unsigned int shndx
)
1638 { return this->elf_file_
.section_contents(shndx
); }
1640 // Return section flags.
1642 do_section_flags(unsigned int shndx
);
1644 // Return section entsize.
1646 do_section_entsize(unsigned int shndx
);
1648 // Return section address.
1650 do_section_address(unsigned int shndx
)
1651 { return this->elf_file_
.section_addr(shndx
); }
1653 // Return section type.
1655 do_section_type(unsigned int shndx
)
1656 { return this->elf_file_
.section_type(shndx
); }
1658 // Return the section link field.
1660 do_section_link(unsigned int shndx
)
1661 { return this->elf_file_
.section_link(shndx
); }
1663 // Return the section info field.
1665 do_section_info(unsigned int shndx
)
1666 { return this->elf_file_
.section_info(shndx
); }
1668 // Return the section alignment.
1670 do_section_addralign(unsigned int shndx
)
1671 { return this->elf_file_
.section_addralign(shndx
); }
1673 // Return the Xindex structure to use.
1675 do_initialize_xindex();
1677 // Get symbol counts.
1679 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
1681 // Get the global symbols.
1683 do_get_global_symbols() const
1684 { return &this->symbols_
; }
1686 // Get the offset of a section.
1688 do_output_section_offset(unsigned int shndx
) const
1690 Address off
= this->get_output_section_offset(shndx
);
1691 if (off
== invalid_address
)
1696 // Set the offset of a section.
1698 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1700 gold_assert(shndx
< this->section_offsets_
.size());
1701 this->section_offsets_
[shndx
] =
1702 (off
== static_cast<uint64_t>(-1)
1704 : convert_types
<Address
, uint64_t>(off
));
1707 // Adjust a section index if necessary.
1709 adjust_shndx(unsigned int shndx
)
1711 if (shndx
>= elfcpp::SHN_LORESERVE
)
1712 shndx
+= this->elf_file_
.large_shndx_offset();
1716 // Initialize input to output maps for section symbols in merged
1719 initialize_input_to_output_maps();
1721 // Free the input to output maps for section symbols in merged
1724 free_input_to_output_maps();
1726 // Return symbol table section index.
1728 symtab_shndx() const
1729 { return this->symtab_shndx_
; }
1731 // Allow a child class to access the ELF file.
1732 elfcpp::Elf_file
<size
, big_endian
, Object
>*
1734 { return &this->elf_file_
; }
1736 // Allow a child class to access the local values.
1739 { return &this->local_values_
; }
1741 // Views and sizes when relocating.
1744 unsigned char* view
;
1745 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
1747 section_size_type view_size
;
1748 bool is_input_output_view
;
1749 bool is_postprocessing_view
;
1752 typedef std::vector
<View_size
> Views
;
1754 // This may be overriden by a child class.
1756 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1757 const unsigned char* pshdrs
, Views
* pviews
);
1759 // Allow a child to set output local symbol count.
1761 set_output_local_symbol_count(unsigned int value
)
1762 { this->output_local_symbol_count_
= value
; }
1766 typedef Sized_relobj
<size
, big_endian
> This
;
1767 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
1768 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1769 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1770 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
1772 // To keep track of discarded comdat sections, we need to map a member
1773 // section index to the object and section index of the corresponding
1775 struct Kept_comdat_section
1777 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
1778 : object(a_object
), shndx(a_shndx
)
1783 typedef std::map
<unsigned int, Kept_comdat_section
>
1784 Kept_comdat_section_table
;
1786 // Find the SHT_SYMTAB section, given the section headers.
1788 find_symtab(const unsigned char* pshdrs
);
1790 // Return whether SHDR has the right flags for a GNU style exception
1793 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
1795 // Return whether there is a section named .eh_frame which might be
1796 // a GNU style exception frame section.
1798 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
1799 section_size_type names_size
) const;
1801 // Whether to include a section group in the link.
1803 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
1804 const unsigned char*, const char *, section_size_type
,
1805 std::vector
<bool>*);
1807 // Whether to include a linkonce section in the link.
1809 include_linkonce_section(Layout
*, unsigned int, const char*,
1810 const elfcpp::Shdr
<size
, big_endian
>&);
1812 // Layout an input section.
1814 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
1815 typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
1816 unsigned int reloc_type
);
1818 // Write section data to the output file. Record the views and
1819 // sizes in VIEWS for use when relocating.
1821 write_sections(const unsigned char* pshdrs
, Output_file
*, Views
*);
1823 // Relocate the sections in the output file.
1825 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1826 const unsigned char* pshdrs
, Views
* pviews
)
1827 { this->do_relocate_sections(symtab
, layout
, pshdrs
, pviews
); }
1829 // Scan the input relocations for --emit-relocs.
1831 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
1832 const Read_relocs_data::Relocs_list::iterator
&);
1834 // Scan the input relocations for --emit-relocs, templatized on the
1835 // type of the relocation section.
1836 template<int sh_type
>
1838 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
1839 const unsigned char* plocal_syms
,
1840 const Read_relocs_data::Relocs_list::iterator
&,
1841 Relocatable_relocs
*);
1843 // Emit the relocs for --emit-relocs.
1845 emit_relocs(const Relocate_info
<size
, big_endian
>*, unsigned int,
1846 unsigned int sh_type
, const unsigned char* prelocs
,
1847 size_t reloc_count
, Output_section
*, Address output_offset
,
1848 unsigned char* view
, Address address
,
1849 section_size_type view_size
,
1850 unsigned char* reloc_view
, section_size_type reloc_view_size
);
1852 // Emit the relocs for --emit-relocs, templatized on the type of the
1853 // relocation section.
1854 template<int sh_type
>
1856 emit_relocs_reltype(const Relocate_info
<size
, big_endian
>*, unsigned int,
1857 const unsigned char* prelocs
, size_t reloc_count
,
1858 Output_section
*, Address output_offset
,
1859 unsigned char* view
, Address address
,
1860 section_size_type view_size
,
1861 unsigned char* reloc_view
,
1862 section_size_type reloc_view_size
);
1864 // A type shared by split_stack_adjust_reltype and find_functions.
1865 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
1867 // Check for -fsplit-stack routines calling non-split-stack routines.
1869 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
1870 unsigned int sh_type
, unsigned int shndx
,
1871 const unsigned char* prelocs
, size_t reloc_count
,
1872 unsigned char* view
, section_size_type view_size
,
1873 Reloc_symbol_changes
** reloc_map
);
1875 template<int sh_type
>
1877 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
1878 unsigned int shndx
, const unsigned char* prelocs
,
1879 size_t reloc_count
, unsigned char* view
,
1880 section_size_type view_size
,
1881 Reloc_symbol_changes
** reloc_map
);
1883 // Find all functions in a section.
1885 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
1888 // Write out the local symbols.
1890 write_local_symbols(Output_file
*,
1891 const Stringpool_template
<char>*,
1892 const Stringpool_template
<char>*,
1893 Output_symtab_xindex
*,
1894 Output_symtab_xindex
*);
1896 // Clear the local symbol information.
1898 clear_local_symbols()
1900 this->local_values_
.clear();
1901 this->local_got_offsets_
.clear();
1904 // Record a mapping from discarded section SHNDX to the corresponding
1907 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
1908 unsigned int kept_shndx
)
1910 Kept_comdat_section
kept(kept_object
, kept_shndx
);
1911 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
1914 // Find the kept section corresponding to the discarded section
1915 // SHNDX. Return true if found.
1917 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
1918 unsigned int* kept_shndx
) const
1920 typename
Kept_comdat_section_table::const_iterator p
=
1921 this->kept_comdat_sections_
.find(shndx
);
1922 if (p
== this->kept_comdat_sections_
.end())
1924 *kept_object
= p
->second
.object
;
1925 *kept_shndx
= p
->second
.shndx
;
1929 // The GOT offsets of local symbols. This map also stores GOT offsets
1930 // for tp-relative offsets for TLS symbols.
1931 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
1933 // The TLS GOT offsets of local symbols. The map stores the offsets
1934 // for either a single GOT entry that holds the module index of a TLS
1935 // symbol, or a pair of GOT entries containing the module index and
1936 // dtv-relative offset.
1937 struct Tls_got_entry
1939 Tls_got_entry(int got_offset
, bool have_pair
)
1940 : got_offset_(got_offset
),
1941 have_pair_(have_pair
)
1946 typedef Unordered_map
<unsigned int, Tls_got_entry
> Local_tls_got_offsets
;
1948 // Saved information for sections whose layout was deferred.
1949 struct Deferred_layout
1951 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1952 Deferred_layout(unsigned int shndx
, const char* name
,
1953 const unsigned char* pshdr
,
1954 unsigned int reloc_shndx
, unsigned int reloc_type
)
1955 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
1956 reloc_type_(reloc_type
)
1958 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
1960 unsigned int shndx_
;
1962 unsigned int reloc_shndx_
;
1963 unsigned int reloc_type_
;
1964 unsigned char shdr_data_
[shdr_size
];
1967 // General access to the ELF file.
1968 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
1969 // Index of SHT_SYMTAB section.
1970 unsigned int symtab_shndx_
;
1971 // The number of local symbols.
1972 unsigned int local_symbol_count_
;
1973 // The number of local symbols which go into the output file.
1974 unsigned int output_local_symbol_count_
;
1975 // The number of local symbols which go into the output file's dynamic
1977 unsigned int output_local_dynsym_count_
;
1978 // The entries in the symbol table for the external symbols.
1980 // Number of symbols defined in object file itself.
1981 size_t defined_count_
;
1982 // File offset for local symbols.
1983 off_t local_symbol_offset_
;
1984 // File offset for local dynamic symbols.
1985 off_t local_dynsym_offset_
;
1986 // Values of local symbols.
1987 Local_values local_values_
;
1988 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1989 // for TLS symbols, indexed by symbol number.
1990 Local_got_offsets local_got_offsets_
;
1991 // For each input section, the offset of the input section in its
1992 // output section. This is INVALID_ADDRESS if the input section requires a
1994 std::vector
<Address
> section_offsets_
;
1995 // Table mapping discarded comdat sections to corresponding kept sections.
1996 Kept_comdat_section_table kept_comdat_sections_
;
1997 // Whether this object has a GNU style .eh_frame section.
1999 // If this object has a GNU style .eh_frame section that is discarded in
2000 // output, record the index here. Otherwise it is -1U.
2001 unsigned int discarded_eh_frame_shndx_
;
2002 // The list of sections whose layout was deferred.
2003 std::vector
<Deferred_layout
> deferred_layout_
;
2006 // A class to manage the list of all objects.
2012 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
2015 // The type of the list of input relocateable objects.
2016 typedef std::vector
<Relobj
*> Relobj_list
;
2017 typedef Relobj_list::const_iterator Relobj_iterator
;
2019 // The type of the list of input dynamic objects.
2020 typedef std::vector
<Dynobj
*> Dynobj_list
;
2021 typedef Dynobj_list::const_iterator Dynobj_iterator
;
2023 // Add an object to the list. Return true if all is well, or false
2024 // if this object should be ignored.
2026 add_object(Object
*);
2028 // Start processing an archive.
2030 archive_start(Archive
*);
2032 // Stop processing an archive.
2034 archive_stop(Archive
*);
2036 // For each dynamic object, check whether we've seen all of its
2037 // explicit dependencies.
2039 check_dynamic_dependencies() const;
2041 // Return whether an object was found in the system library
2044 found_in_system_library_directory(const Object
*) const;
2046 // Print symbol counts.
2048 print_symbol_counts(const Symbol_table
*) const;
2050 // Print a cross reference table.
2052 print_cref(const Symbol_table
*, FILE*) const;
2054 // Iterate over all regular objects.
2057 relobj_begin() const
2058 { return this->relobj_list_
.begin(); }
2062 { return this->relobj_list_
.end(); }
2064 // Iterate over all dynamic objects.
2067 dynobj_begin() const
2068 { return this->dynobj_list_
.begin(); }
2072 { return this->dynobj_list_
.end(); }
2074 // Return whether we have seen any dynamic objects.
2077 { return !this->dynobj_list_
.empty(); }
2079 // Return the number of non dynamic objects.
2081 number_of_relobjs() const
2082 { return this->relobj_list_
.size(); }
2084 // Return the number of input objects.
2086 number_of_input_objects() const
2087 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
2090 Input_objects(const Input_objects
&);
2091 Input_objects
& operator=(const Input_objects
&);
2093 // The list of ordinary objects included in the link.
2094 Relobj_list relobj_list_
;
2095 // The list of dynamic objects included in the link.
2096 Dynobj_list dynobj_list_
;
2097 // SONAMEs that we have seen.
2098 Unordered_set
<std::string
> sonames_
;
2099 // Manage cross-references if requested.
2103 // Some of the information we pass to the relocation routines. We
2104 // group this together to avoid passing a dozen different arguments.
2106 template<int size
, bool big_endian
>
2107 struct Relocate_info
2110 const Symbol_table
* symtab
;
2112 const Layout
* layout
;
2113 // Object being relocated.
2114 Sized_relobj
<size
, big_endian
>* object
;
2115 // Section index of relocation section.
2116 unsigned int reloc_shndx
;
2117 // Section header of relocation section.
2118 const unsigned char* reloc_shdr
;
2119 // Section index of section being relocated.
2120 unsigned int data_shndx
;
2121 // Section header of data section.
2122 const unsigned char* data_shdr
;
2124 // Return a string showing the location of a relocation. This is
2125 // only used for error messages.
2127 location(size_t relnum
, off_t reloffset
) const;
2130 // This is used to represent a section in an object and is used as the
2131 // key type for various section maps.
2132 typedef std::pair
<Object
*, unsigned int> Section_id
;
2134 // This is similar to Section_id but is used when the section
2135 // pointers are const.
2136 typedef std::pair
<const Object
*, unsigned int> Const_section_id
;
2138 // The hash value is based on the address of an object in memory during
2139 // linking. It is okay to use this for looking up sections but never use
2140 // this in an unordered container that we want to traverse in a repeatable
2143 struct Section_id_hash
2145 size_t operator()(const Section_id
& loc
) const
2146 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2149 struct Const_section_id_hash
2151 size_t operator()(const Const_section_id
& loc
) const
2152 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2155 // Return whether INPUT_FILE contains an ELF object start at file
2156 // offset OFFSET. This sets *START to point to a view of the start of
2157 // the file. It sets *READ_SIZE to the number of bytes in the view.
2160 is_elf_object(Input_file
* input_file
, off_t offset
,
2161 const unsigned char** start
, int *read_size
);
2163 // Return an Object appropriate for the input file. P is BYTES long,
2164 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2165 // this sees an object the linker is not configured to support, it
2166 // sets *PUNCONFIGURED to true and returns NULL without giving an
2170 make_elf_object(const std::string
& name
, Input_file
*,
2171 off_t offset
, const unsigned char* p
,
2172 section_offset_type bytes
, bool* punconfigured
);
2174 } // end namespace gold
2176 #endif // !defined(GOLD_OBJECT_H)