1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
30 #include "elfcpp_file.h"
37 class General_options
;
44 class Output_symtab_xindex
;
47 class Object_merge_map
;
48 class Relocatable_relocs
;
51 template<typename Stringpool_char
>
52 class Stringpool_template
;
54 // Data to pass from read_symbols() to add_symbols().
56 struct Read_symbols_data
59 File_view
* section_headers
;
61 File_view
* section_names
;
62 // Size of section name data in bytes.
63 section_size_type section_names_size
;
66 // Size of symbol data in bytes.
67 section_size_type symbols_size
;
68 // Offset of external symbols within symbol data. This structure
69 // sometimes contains only external symbols, in which case this will
70 // be zero. Sometimes it contains all symbols.
71 section_offset_type external_symbols_offset
;
73 File_view
* symbol_names
;
74 // Size of symbol name data in bytes.
75 section_size_type symbol_names_size
;
77 // Version information. This is only used on dynamic objects.
78 // Version symbol data (from SHT_GNU_versym section).
80 section_size_type versym_size
;
81 // Version definition data (from SHT_GNU_verdef section).
83 section_size_type verdef_size
;
84 unsigned int verdef_info
;
85 // Needed version data (from SHT_GNU_verneed section).
87 section_size_type verneed_size
;
88 unsigned int verneed_info
;
91 // Information used to print error messages.
93 struct Symbol_location_info
95 std::string source_file
;
96 std::string enclosing_symbol_name
;
100 // Data about a single relocation section. This is read in
101 // read_relocs and processed in scan_relocs.
103 struct Section_relocs
105 // Index of reloc section.
106 unsigned int reloc_shndx
;
107 // Index of section that relocs apply to.
108 unsigned int data_shndx
;
109 // Contents of reloc section.
111 // Reloc section type.
112 unsigned int sh_type
;
113 // Number of reloc entries.
116 Output_section
* output_section
;
117 // Whether this section has special handling for offsets.
118 bool needs_special_offset_handling
;
119 // Whether the data section is allocated (has the SHF_ALLOC flag set).
120 bool is_data_section_allocated
;
123 // Relocations in an object file. This is read in read_relocs and
124 // processed in scan_relocs.
126 struct Read_relocs_data
128 typedef std::vector
<Section_relocs
> Relocs_list
;
131 // The local symbols.
132 File_view
* local_symbols
;
135 // The Xindex class manages section indexes for objects with more than
141 Xindex(int large_shndx_offset
)
142 : large_shndx_offset_(large_shndx_offset
), symtab_xindex_()
145 // Initialize the symtab_xindex_ array, given the object and the
146 // section index of the symbol table to use.
147 template<int size
, bool big_endian
>
149 initialize_symtab_xindex(Object
*, unsigned int symtab_shndx
);
151 // Read in the symtab_xindex_ array, given its section index.
152 // PSHDRS may optionally point to the section headers.
153 template<int size
, bool big_endian
>
155 read_symtab_xindex(Object
*, unsigned int xindex_shndx
,
156 const unsigned char* pshdrs
);
158 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
159 // real section index.
161 sym_xindex_to_shndx(Object
* object
, unsigned int symndx
);
164 // The type of the array giving the real section index for symbols
165 // whose st_shndx field holds SHN_XINDEX.
166 typedef std::vector
<unsigned int> Symtab_xindex
;
168 // Adjust a section index if necessary. This should only be called
169 // for ordinary section indexes.
171 adjust_shndx(unsigned int shndx
)
173 if (shndx
>= elfcpp::SHN_LORESERVE
)
174 shndx
+= this->large_shndx_offset_
;
178 // Adjust to apply to large section indexes.
179 int large_shndx_offset_
;
180 // The data from the SHT_SYMTAB_SHNDX section.
181 Symtab_xindex symtab_xindex_
;
184 // Object is an abstract base class which represents either a 32-bit
185 // or a 64-bit input object. This can be a regular object file
186 // (ET_REL) or a shared object (ET_DYN).
191 // NAME is the name of the object as we would report it to the user
192 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
193 // used to read the file. OFFSET is the offset within the input
194 // file--0 for a .o or .so file, something else for a .a file.
195 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
197 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
198 is_dynamic_(is_dynamic
), is_needed_(false), uses_split_stack_(false),
199 has_no_split_stack_(false), no_export_(false), xindex_(NULL
)
200 { input_file
->file().add_object(); }
203 { this->input_file_
->file().remove_object(); }
205 // Return the name of the object as we would report it to the tuser.
208 { return this->name_
; }
210 // Get the offset into the file.
213 { return this->offset_
; }
215 // Return whether this is a dynamic object.
218 { return this->is_dynamic_
; }
220 // Return whether this object is needed--true if it is a dynamic
221 // object which defines some symbol referenced by a regular object.
222 // We keep the flag here rather than in Dynobj for convenience when
226 { return this->is_needed_
; }
228 // Record that this object is needed.
231 { this->is_needed_
= true; }
233 // Return whether this object was compiled with -fsplit-stack.
235 uses_split_stack() const
236 { return this->uses_split_stack_
; }
238 // Return whether this object contains any functions compiled with
239 // the no_split_stack attribute.
241 has_no_split_stack() const
242 { return this->has_no_split_stack_
; }
244 // Returns NULL for Objects that are not plugin objects. This method
245 // is overridden in the Pluginobj class.
248 { return this->do_pluginobj(); }
250 // Get the file. We pass on const-ness.
253 { return this->input_file_
; }
257 { return this->input_file_
; }
259 // Lock the underlying file.
262 { this->input_file()->file().lock(t
); }
264 // Unlock the underlying file.
266 unlock(const Task
* t
)
267 { this->input_file()->file().unlock(t
); }
269 // Return whether the underlying file is locked.
272 { return this->input_file()->file().is_locked(); }
274 // Return the token, so that the task can be queued.
277 { return this->input_file()->file().token(); }
279 // Release the underlying file.
282 { this->input_file_
->file().release(); }
284 // Return whether we should just read symbols from this file.
287 { return this->input_file()->just_symbols(); }
289 // Get the number of sections.
292 { return this->shnum_
; }
294 // Return a view of the contents of a section. Set *PLEN to the
295 // size. CACHE is a hint as in File_read::get_view.
297 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
299 // Adjust a symbol's section index as needed. SYMNDX is the index
300 // of the symbol and SHNDX is the symbol's section from
301 // get_st_shndx. This returns the section index. It sets
302 // *IS_ORDINARY to indicate whether this is a normal section index,
303 // rather than a special code between SHN_LORESERVE and
306 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
308 if (shndx
< elfcpp::SHN_LORESERVE
)
310 else if (shndx
== elfcpp::SHN_XINDEX
)
312 if (this->xindex_
== NULL
)
313 this->xindex_
= this->do_initialize_xindex();
314 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
318 *is_ordinary
= false;
322 // Return the size of a section given a section index.
324 section_size(unsigned int shndx
)
325 { return this->do_section_size(shndx
); }
327 // Return the name of a section given a section index.
329 section_name(unsigned int shndx
)
330 { return this->do_section_name(shndx
); }
332 // Return the section flags given a section index.
334 section_flags(unsigned int shndx
)
335 { return this->do_section_flags(shndx
); }
337 // Return the section entsize given a section index.
339 section_entsize(unsigned int shndx
)
340 { return this->do_section_entsize(shndx
); }
342 // Return the section address given a section index.
344 section_address(unsigned int shndx
)
345 { return this->do_section_address(shndx
); }
347 // Return the section type given a section index.
349 section_type(unsigned int shndx
)
350 { return this->do_section_type(shndx
); }
352 // Return the section link field given a section index.
354 section_link(unsigned int shndx
)
355 { return this->do_section_link(shndx
); }
357 // Return the section info field given a section index.
359 section_info(unsigned int shndx
)
360 { return this->do_section_info(shndx
); }
362 // Return the required section alignment given a section index.
364 section_addralign(unsigned int shndx
)
365 { return this->do_section_addralign(shndx
); }
367 // Read the symbol information.
369 read_symbols(Read_symbols_data
* sd
)
370 { return this->do_read_symbols(sd
); }
372 // Pass sections which should be included in the link to the Layout
373 // object, and record where the sections go in the output file.
375 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
376 { this->do_layout(symtab
, layout
, sd
); }
378 // Add symbol information to the global symbol table.
380 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
381 { this->do_add_symbols(symtab
, sd
, layout
); }
383 // Functions and types for the elfcpp::Elf_file interface. This
384 // permit us to use Object as the File template parameter for
387 // The View class is returned by view. It must support a single
388 // method, data(). This is trivial, because get_view does what we
393 View(const unsigned char* p
)
402 const unsigned char* p_
;
407 view(off_t file_offset
, section_size_type data_size
)
408 { return View(this->get_view(file_offset
, data_size
, true, true)); }
412 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
414 // A location in the file.
420 Location(off_t fo
, section_size_type ds
)
421 : file_offset(fo
), data_size(ds
)
425 // Get a View given a Location.
426 View
view(Location loc
)
427 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
429 // Get a view into the underlying file.
431 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
433 return this->input_file()->file().get_view(this->offset_
, start
, size
,
437 // Get a lasting view into the underlying file.
439 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
442 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
443 size
, aligned
, cache
);
446 // Read data from the underlying file.
448 read(off_t start
, section_size_type size
, void* p
)
449 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
451 // Read multiple data from the underlying file.
453 read_multiple(const File_read::Read_multiple
& rm
)
454 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
456 // Stop caching views in the underlying file.
458 clear_view_cache_marks()
459 { this->input_file()->file().clear_view_cache_marks(); }
461 // Get the number of global symbols defined by this object, and the
462 // number of the symbols whose final definition came from this
465 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
467 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
469 // Return whether this object was found in a system directory.
471 is_in_system_directory() const
472 { return this->input_file()->is_in_system_directory(); }
474 // Return whether we found this object by searching a directory.
477 { return this->input_file()->will_search_for(); }
481 { return this->no_export_
; }
484 set_no_export(bool value
)
485 { this->no_export_
= value
; }
488 // Returns NULL for Objects that are not plugin objects. This method
489 // is overridden in the Pluginobj class.
494 // Read the symbols--implemented by child class.
496 do_read_symbols(Read_symbols_data
*) = 0;
498 // Lay out sections--implemented by child class.
500 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
502 // Add symbol information to the global symbol table--implemented by
505 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
507 // Return the location of the contents of a section. Implemented by
510 do_section_contents(unsigned int shndx
) = 0;
512 // Get the size of a section--implemented by child class.
514 do_section_size(unsigned int shndx
) = 0;
516 // Get the name of a section--implemented by child class.
518 do_section_name(unsigned int shndx
) = 0;
520 // Get section flags--implemented by child class.
522 do_section_flags(unsigned int shndx
) = 0;
524 // Get section entsize--implemented by child class.
526 do_section_entsize(unsigned int shndx
) = 0;
528 // Get section address--implemented by child class.
530 do_section_address(unsigned int shndx
) = 0;
532 // Get section type--implemented by child class.
534 do_section_type(unsigned int shndx
) = 0;
536 // Get section link field--implemented by child class.
538 do_section_link(unsigned int shndx
) = 0;
540 // Get section info field--implemented by child class.
542 do_section_info(unsigned int shndx
) = 0;
544 // Get section alignment--implemented by child class.
546 do_section_addralign(unsigned int shndx
) = 0;
548 // Return the Xindex structure to use.
550 do_initialize_xindex() = 0;
552 // Implement get_global_symbol_counts--implemented by child class.
554 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
556 // Set the number of sections.
559 { this->shnum_
= shnum
; }
561 // Functions used by both Sized_relobj and Sized_dynobj.
563 // Read the section data into a Read_symbols_data object.
564 template<int size
, bool big_endian
>
566 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
569 // Let the child class initialize the xindex object directly.
571 set_xindex(Xindex
* xindex
)
573 gold_assert(this->xindex_
== NULL
);
574 this->xindex_
= xindex
;
577 // If NAME is the name of a special .gnu.warning section, arrange
578 // for the warning to be issued. SHNDX is the section index.
579 // Return whether it is a warning section.
581 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
584 // If NAME is the name of the special section which indicates that
585 // this object was compiled with -fstack-split, mark it accordingly,
586 // and return true. Otherwise return false.
588 handle_split_stack_section(const char* name
);
591 // This class may not be copied.
592 Object(const Object
&);
593 Object
& operator=(const Object
&);
595 // Name of object as printed to user.
597 // For reading the file.
598 Input_file
* input_file_
;
599 // Offset within the file--0 for an object file, non-0 for an
602 // Number of input sections.
604 // Whether this is a dynamic object.
605 bool is_dynamic_
: 1;
606 // Whether this object is needed. This is only set for dynamic
607 // objects, and means that the object defined a symbol which was
608 // used by a reference from a regular object.
610 // Whether this object was compiled with -fsplit-stack.
611 bool uses_split_stack_
: 1;
612 // Whether this object contains any functions compiled with the
613 // no_split_stack attribute.
614 bool has_no_split_stack_
: 1;
615 // True if exclude this object from automatic symbol export.
616 // This is used only for archive objects.
618 // Many sections for objects with more than SHN_LORESERVE sections.
622 // A regular object (ET_REL). This is an abstract base class itself.
623 // The implementation is the template class Sized_relobj.
625 class Relobj
: public Object
628 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
629 : Object(name
, input_file
, false, offset
),
631 map_to_relocatable_relocs_(NULL
),
632 object_merge_map_(NULL
),
633 relocs_must_follow_section_writes_(false),
637 // During garbage collection, the Read_symbols_data pass for
638 // each object is stored as layout needs to be done after
642 { return this->sd_
; }
644 // Decides which section names have to be included in the worklist
647 is_section_name_included(const char *name
);
650 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
651 unsigned int section_header_size
);
654 set_symbols_data(Symbols_data
* sd
)
657 // During garbage collection, the Read_relocs pass for all objects
658 // is done before scanning the relocs. In that case, this->rd_ is
659 // used to store the information from Read_relocs for each object.
660 // This data is also used to compute the list of relevant sections.
663 { return this->rd_
; }
666 set_relocs_data(Read_relocs_data
* rd
)
670 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
674 read_relocs(Read_relocs_data
* rd
)
675 { return this->do_read_relocs(rd
); }
677 // Process the relocs, during garbage collection only.
679 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
680 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
682 // Scan the relocs and adjust the symbol table.
684 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
685 { return this->do_scan_relocs(symtab
, layout
, rd
); }
687 // The number of local symbols in the input symbol table.
689 local_symbol_count() const
690 { return this->do_local_symbol_count(); }
692 // Initial local symbol processing: count the number of local symbols
693 // in the output symbol table and dynamic symbol table; add local symbol
694 // names to *POOL and *DYNPOOL.
696 count_local_symbols(Stringpool_template
<char>* pool
,
697 Stringpool_template
<char>* dynpool
)
698 { return this->do_count_local_symbols(pool
, dynpool
); }
700 // Set the values of the local symbols, set the output symbol table
701 // indexes for the local variables, and set the offset where local
702 // symbol information will be stored. Returns the new local symbol index.
704 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
705 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
707 // Set the output dynamic symbol table indexes for the local variables.
709 set_local_dynsym_indexes(unsigned int index
)
710 { return this->do_set_local_dynsym_indexes(index
); }
712 // Set the offset where local dynamic symbol information will be stored.
714 set_local_dynsym_offset(off_t off
)
715 { return this->do_set_local_dynsym_offset(off
); }
717 // Relocate the input sections and write out the local symbols.
719 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
720 { return this->do_relocate(symtab
, layout
, of
); }
722 // Return whether an input section is being included in the link.
724 is_section_included(unsigned int shndx
) const
726 gold_assert(shndx
< this->output_sections_
.size());
727 return this->output_sections_
[shndx
] != NULL
;
730 // Given a section index, return the corresponding Output_section.
731 // The return value will be NULL if the section is not included in
734 output_section(unsigned int shndx
) const
736 gold_assert(shndx
< this->output_sections_
.size());
737 return this->output_sections_
[shndx
];
740 // Given a section index, return the offset in the Output_section.
741 // The return value will be -1U if the section is specially mapped,
742 // such as a merge section.
744 output_section_offset(unsigned int shndx
) const
745 { return this->do_output_section_offset(shndx
); }
747 // Set the offset of an input section within its output section.
749 set_section_offset(unsigned int shndx
, uint64_t off
)
750 { this->do_set_section_offset(shndx
, off
); }
752 // Return true if we need to wait for output sections to be written
753 // before we can apply relocations. This is true if the object has
754 // any relocations for sections which require special handling, such
755 // as the exception frame section.
757 relocs_must_follow_section_writes() const
758 { return this->relocs_must_follow_section_writes_
; }
760 // Return the object merge map.
763 { return this->object_merge_map_
; }
765 // Set the object merge map.
767 set_merge_map(Object_merge_map
* object_merge_map
)
769 gold_assert(this->object_merge_map_
== NULL
);
770 this->object_merge_map_
= object_merge_map
;
773 // Record the relocatable reloc info for an input reloc section.
775 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
777 gold_assert(reloc_shndx
< this->shnum());
778 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
781 // Get the relocatable reloc info for an input reloc section.
783 relocatable_relocs(unsigned int reloc_shndx
)
785 gold_assert(reloc_shndx
< this->shnum());
786 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
789 // Layout sections whose layout was deferred while waiting for
790 // input files from a plugin.
792 layout_deferred_sections(Layout
* layout
)
793 { this->do_layout_deferred_sections(layout
); }
796 // The output section to be used for each input section, indexed by
797 // the input section number. The output section is NULL if the
798 // input section is to be discarded.
799 typedef std::vector
<Output_section
*> Output_sections
;
801 // Read the relocs--implemented by child class.
803 do_read_relocs(Read_relocs_data
*) = 0;
805 // Process the relocs--implemented by child class.
807 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
809 // Scan the relocs--implemented by child class.
811 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
813 // Return the number of local symbols--implemented by child class.
815 do_local_symbol_count() const = 0;
817 // Count local symbols--implemented by child class.
819 do_count_local_symbols(Stringpool_template
<char>*,
820 Stringpool_template
<char>*) = 0;
822 // Finalize the local symbols. Set the output symbol table indexes
823 // for the local variables, and set the offset where local symbol
824 // information will be stored.
826 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
828 // Set the output dynamic symbol table indexes for the local variables.
830 do_set_local_dynsym_indexes(unsigned int) = 0;
832 // Set the offset where local dynamic symbol information will be stored.
834 do_set_local_dynsym_offset(off_t
) = 0;
836 // Relocate the input sections and write out the local
837 // symbols--implemented by child class.
839 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
841 // Get the offset of a section--implemented by child class.
843 do_output_section_offset(unsigned int shndx
) const = 0;
845 // Set the offset of a section--implemented by child class.
847 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
849 // Layout sections whose layout was deferred while waiting for
850 // input files from a plugin--implemented by child class.
852 do_layout_deferred_sections(Layout
*) = 0;
854 // Return the vector mapping input sections to output sections.
857 { return this->output_sections_
; }
859 const Output_sections
&
860 output_sections() const
861 { return this->output_sections_
; }
863 // Set the size of the relocatable relocs array.
865 size_relocatable_relocs()
867 this->map_to_relocatable_relocs_
=
868 new std::vector
<Relocatable_relocs
*>(this->shnum());
871 // Record that we must wait for the output sections to be written
872 // before applying relocations.
874 set_relocs_must_follow_section_writes()
875 { this->relocs_must_follow_section_writes_
= true; }
878 // Mapping from input sections to output section.
879 Output_sections output_sections_
;
880 // Mapping from input section index to the information recorded for
881 // the relocations. This is only used for a relocatable link.
882 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
883 // Mappings for merge sections. This is managed by the code in the
885 Object_merge_map
* object_merge_map_
;
886 // Whether we need to wait for output sections to be written before
887 // we can apply relocations.
888 bool relocs_must_follow_section_writes_
;
889 // Used to store the relocs data computed by the Read_relocs pass.
890 // Used during garbage collection of unused sections.
891 Read_relocs_data
* rd_
;
892 // Used to store the symbols data computed by the Read_symbols pass.
893 // Again used during garbage collection when laying out referenced
895 gold::Symbols_data
*sd_
;
898 // This class is used to handle relocations against a section symbol
899 // in an SHF_MERGE section. For such a symbol, we need to know the
900 // addend of the relocation before we can determine the final value.
901 // The addend gives us the location in the input section, and we can
902 // determine how it is mapped to the output section. For a
903 // non-section symbol, we apply the addend to the final value of the
904 // symbol; that is done in finalize_local_symbols, and does not use
908 class Merged_symbol_value
911 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
913 // We use a hash table to map offsets in the input section to output
915 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
917 Merged_symbol_value(Value input_value
, Value output_start_address
)
918 : input_value_(input_value
), output_start_address_(output_start_address
),
922 // Initialize the hash table.
924 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
926 // Release the hash table to save space.
928 free_input_to_output_map()
929 { this->output_addresses_
.clear(); }
931 // Get the output value corresponding to an addend. The object and
932 // input section index are passed in because the caller will have
933 // them; otherwise we could store them here.
935 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
937 // This is a relocation against a section symbol. ADDEND is the
938 // offset in the section. The result should be the start of some
939 // merge area. If the object file wants something else, it should
940 // use a regular symbol rather than a section symbol.
941 // Unfortunately, PR 6658 shows a case in which the object file
942 // refers to the section symbol, but uses a negative ADDEND to
943 // compensate for a PC relative reloc. We can't handle the
944 // general case. However, we can handle the special case of a
945 // negative addend, by assuming that it refers to the start of the
946 // section. Of course, that means that we have to guess when
947 // ADDEND is negative. It is normal to see a 32-bit value here
948 // even when the template parameter size is 64, as 64-bit object
949 // file formats have 32-bit relocations. We know this is a merge
950 // section, so we know it has to fit into memory. So we assume
951 // that we won't see a value larger than a large 32-bit unsigned
952 // value. This will break objects with very very large merge
953 // sections; they probably break in other ways anyhow.
954 Value input_offset
= this->input_value_
;
955 if (addend
< 0xffffff00)
957 input_offset
+= addend
;
960 typename
Output_addresses::const_iterator p
=
961 this->output_addresses_
.find(input_offset
);
962 if (p
!= this->output_addresses_
.end())
963 return p
->second
+ addend
;
965 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
970 // Get the output value for an input offset if we couldn't find it
971 // in the hash table.
973 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
974 Value input_offset
) const;
976 // The value of the section symbol in the input file. This is
977 // normally zero, but could in principle be something else.
979 // The start address of this merged section in the output file.
980 Value output_start_address_
;
981 // A hash table which maps offsets in the input section to output
982 // addresses. This only maps specific offsets, not all offsets.
983 Output_addresses output_addresses_
;
986 // This POD class is holds the value of a symbol. This is used for
987 // local symbols, and for all symbols during relocation processing.
988 // For special sections, such as SHF_MERGE sections, this calls a
989 // function to get the final symbol value.
995 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
998 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
999 is_ordinary_shndx_(false), is_section_symbol_(false),
1000 is_tls_symbol_(false), has_output_value_(true)
1001 { this->u_
.value
= 0; }
1003 // Get the value of this symbol. OBJECT is the object in which this
1004 // symbol is defined, and ADDEND is an addend to add to the value.
1005 template<bool big_endian
>
1007 value(const Sized_relobj
<size
, big_endian
>* object
, Value addend
) const
1009 if (this->has_output_value_
)
1010 return this->u_
.value
+ addend
;
1013 gold_assert(this->is_ordinary_shndx_
);
1014 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1019 // Set the value of this symbol in the output symbol table.
1021 set_output_value(Value value
)
1022 { this->u_
.value
= value
; }
1024 // For a section symbol in a merged section, we need more
1027 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1029 gold_assert(this->is_section_symbol_
);
1030 this->has_output_value_
= false;
1031 this->u_
.merged_symbol_value
= msv
;
1034 // Initialize the input to output map for a section symbol in a
1035 // merged section. We also initialize the value of a non-section
1036 // symbol in a merged section.
1038 initialize_input_to_output_map(const Relobj
* object
)
1040 if (!this->has_output_value_
)
1042 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1043 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1044 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1048 // Free the input to output map for a section symbol in a merged
1051 free_input_to_output_map()
1053 if (!this->has_output_value_
)
1054 this->u_
.merged_symbol_value
->free_input_to_output_map();
1057 // Set the value of the symbol from the input file. This is only
1058 // called by count_local_symbols, to communicate the value to
1059 // finalize_local_symbols.
1061 set_input_value(Value value
)
1062 { this->u_
.value
= value
; }
1064 // Return the input value. This is only called by
1065 // finalize_local_symbols and (in special cases) relocate_section.
1068 { return this->u_
.value
; }
1070 // Return whether this symbol should go into the output symbol
1073 needs_output_symtab_entry() const
1074 { return this->output_symtab_index_
!= -1U; }
1076 // Return the index in the output symbol table.
1078 output_symtab_index() const
1080 gold_assert(this->output_symtab_index_
!= 0);
1081 return this->output_symtab_index_
;
1084 // Set the index in the output symbol table.
1086 set_output_symtab_index(unsigned int i
)
1088 gold_assert(this->output_symtab_index_
== 0);
1089 this->output_symtab_index_
= i
;
1092 // Record that this symbol should not go into the output symbol
1095 set_no_output_symtab_entry()
1097 gold_assert(this->output_symtab_index_
== 0);
1098 this->output_symtab_index_
= -1U;
1101 // Set the index in the output dynamic symbol table.
1103 set_needs_output_dynsym_entry()
1105 gold_assert(!this->is_section_symbol());
1106 this->output_dynsym_index_
= 0;
1109 // Return whether this symbol should go into the output symbol
1112 needs_output_dynsym_entry() const
1114 return this->output_dynsym_index_
!= -1U;
1117 // Record that this symbol should go into the dynamic symbol table.
1119 set_output_dynsym_index(unsigned int i
)
1121 gold_assert(this->output_dynsym_index_
== 0);
1122 this->output_dynsym_index_
= i
;
1125 // Return the index in the output dynamic symbol table.
1127 output_dynsym_index() const
1129 gold_assert(this->output_dynsym_index_
!= 0
1130 && this->output_dynsym_index_
!= -1U);
1131 return this->output_dynsym_index_
;
1134 // Set the index of the input section in the input file.
1136 set_input_shndx(unsigned int i
, bool is_ordinary
)
1138 this->input_shndx_
= i
;
1139 // input_shndx_ field is a bitfield, so make sure that the value
1141 gold_assert(this->input_shndx_
== i
);
1142 this->is_ordinary_shndx_
= is_ordinary
;
1145 // Return the index of the input section in the input file.
1147 input_shndx(bool* is_ordinary
) const
1149 *is_ordinary
= this->is_ordinary_shndx_
;
1150 return this->input_shndx_
;
1153 // Whether this is a section symbol.
1155 is_section_symbol() const
1156 { return this->is_section_symbol_
; }
1158 // Record that this is a section symbol.
1160 set_is_section_symbol()
1162 gold_assert(!this->needs_output_dynsym_entry());
1163 this->is_section_symbol_
= true;
1166 // Record that this is a TLS symbol.
1169 { this->is_tls_symbol_
= true; }
1171 // Return TRUE if this is a TLS symbol.
1173 is_tls_symbol() const
1174 { return this->is_tls_symbol_
; }
1177 // The index of this local symbol in the output symbol table. This
1178 // will be -1 if the symbol should not go into the symbol table.
1179 unsigned int output_symtab_index_
;
1180 // The index of this local symbol in the dynamic symbol table. This
1181 // will be -1 if the symbol should not go into the symbol table.
1182 unsigned int output_dynsym_index_
;
1183 // The section index in the input file in which this symbol is
1185 unsigned int input_shndx_
: 28;
1186 // Whether the section index is an ordinary index, not a special
1188 bool is_ordinary_shndx_
: 1;
1189 // Whether this is a STT_SECTION symbol.
1190 bool is_section_symbol_
: 1;
1191 // Whether this is a STT_TLS symbol.
1192 bool is_tls_symbol_
: 1;
1193 // Whether this symbol has a value for the output file. This is
1194 // normally set to true during Layout::finalize, by
1195 // finalize_local_symbols. It will be false for a section symbol in
1196 // a merge section, as for such symbols we can not determine the
1197 // value to use in a relocation until we see the addend.
1198 bool has_output_value_
: 1;
1201 // This is used if has_output_value_ is true. Between
1202 // count_local_symbols and finalize_local_symbols, this is the
1203 // value in the input file. After finalize_local_symbols, it is
1204 // the value in the output file.
1206 // This is used if has_output_value_ is false. It points to the
1207 // information we need to get the value for a merge section.
1208 Merged_symbol_value
<size
>* merged_symbol_value
;
1212 // A GOT offset list. A symbol may have more than one GOT offset
1213 // (e.g., when mixing modules compiled with two different TLS models),
1214 // but will usually have at most one. GOT_TYPE identifies the type of
1215 // GOT entry; its values are specific to each target.
1217 class Got_offset_list
1221 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
1224 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
1225 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
1230 if (this->got_next_
!= NULL
)
1232 delete this->got_next_
;
1233 this->got_next_
= NULL
;
1237 // Initialize the fields to their default values.
1241 this->got_type_
= -1U;
1242 this->got_offset_
= 0;
1243 this->got_next_
= NULL
;
1246 // Set the offset for the GOT entry of type GOT_TYPE.
1248 set_offset(unsigned int got_type
, unsigned int got_offset
)
1250 if (this->got_type_
== -1U)
1252 this->got_type_
= got_type
;
1253 this->got_offset_
= got_offset
;
1257 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1259 if (g
->got_type_
== got_type
)
1261 g
->got_offset_
= got_offset
;
1265 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1266 g
->got_next_
= this->got_next_
;
1267 this->got_next_
= g
;
1271 // Return the offset for a GOT entry of type GOT_TYPE.
1273 get_offset(unsigned int got_type
) const
1275 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1277 if (g
->got_type_
== got_type
)
1278 return g
->got_offset_
;
1284 unsigned int got_type_
;
1285 unsigned int got_offset_
;
1286 Got_offset_list
* got_next_
;
1289 // This type is used to modify relocations for -fsplit-stack. It is
1290 // indexed by relocation index, and means that the relocation at that
1291 // index should use the symbol from the vector, rather than the one
1292 // indicated by the relocation.
1294 class Reloc_symbol_changes
1297 Reloc_symbol_changes(size_t count
)
1302 set(size_t i
, Symbol
* sym
)
1303 { this->vec_
[i
] = sym
; }
1306 operator[](size_t i
) const
1307 { return this->vec_
[i
]; }
1310 std::vector
<Symbol
*> vec_
;
1313 // A regular object file. This is size and endian specific.
1315 template<int size
, bool big_endian
>
1316 class Sized_relobj
: public Relobj
1319 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1320 typedef std::vector
<Symbol
*> Symbols
;
1321 typedef std::vector
<Symbol_value
<size
> > Local_values
;
1323 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1325 Sized_relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
,
1326 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
1330 // Checks if the offset of input section SHNDX within its output
1331 // section is invalid.
1333 is_output_section_offset_invalid(unsigned int shndx
) const
1334 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1336 // Set up the object file based on TARGET.
1339 { this->do_setup(); }
1341 // Return the number of symbols. This is only valid after
1342 // Object::add_symbols has been called.
1344 symbol_count() const
1345 { return this->local_symbol_count_
+ this->symbols_
.size(); }
1347 // If SYM is the index of a global symbol in the object file's
1348 // symbol table, return the Symbol object. Otherwise, return NULL.
1350 global_symbol(unsigned int sym
) const
1352 if (sym
>= this->local_symbol_count_
)
1354 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
1355 return this->symbols_
[sym
- this->local_symbol_count_
];
1360 // Return the section index of symbol SYM. Set *VALUE to its value
1361 // in the object file. Set *IS_ORDINARY if this is an ordinary
1362 // section index, not a special code between SHN_LORESERVE and
1363 // SHN_HIRESERVE. Note that for a symbol which is not defined in
1364 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
1365 // it will not return the final value of the symbol in the link.
1367 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
1369 // Return a pointer to the Symbol_value structure which holds the
1370 // value of a local symbol.
1371 const Symbol_value
<size
>*
1372 local_symbol(unsigned int sym
) const
1374 gold_assert(sym
< this->local_values_
.size());
1375 return &this->local_values_
[sym
];
1378 // Return the index of local symbol SYM in the ordinary symbol
1379 // table. A value of -1U means that the symbol is not being output.
1381 symtab_index(unsigned int sym
) const
1383 gold_assert(sym
< this->local_values_
.size());
1384 return this->local_values_
[sym
].output_symtab_index();
1387 // Return the index of local symbol SYM in the dynamic symbol
1388 // table. A value of -1U means that the symbol is not being output.
1390 dynsym_index(unsigned int sym
) const
1392 gold_assert(sym
< this->local_values_
.size());
1393 return this->local_values_
[sym
].output_dynsym_index();
1396 // Return the input section index of local symbol SYM.
1398 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
1400 gold_assert(sym
< this->local_values_
.size());
1401 return this->local_values_
[sym
].input_shndx(is_ordinary
);
1404 // Record that local symbol SYM needs a dynamic symbol entry.
1406 set_needs_output_dynsym_entry(unsigned int sym
)
1408 gold_assert(sym
< this->local_values_
.size());
1409 this->local_values_
[sym
].set_needs_output_dynsym_entry();
1412 // Return whether the local symbol SYMNDX has a GOT offset.
1413 // For TLS symbols, the GOT entry will hold its tp-relative offset.
1415 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1417 Local_got_offsets::const_iterator p
=
1418 this->local_got_offsets_
.find(symndx
);
1419 return (p
!= this->local_got_offsets_
.end()
1420 && p
->second
->get_offset(got_type
) != -1U);
1423 // Return the GOT offset of the local symbol SYMNDX.
1425 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1427 Local_got_offsets::const_iterator p
=
1428 this->local_got_offsets_
.find(symndx
);
1429 gold_assert(p
!= this->local_got_offsets_
.end());
1430 unsigned int off
= p
->second
->get_offset(got_type
);
1431 gold_assert(off
!= -1U);
1435 // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
1437 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1438 unsigned int got_offset
)
1440 Local_got_offsets::const_iterator p
=
1441 this->local_got_offsets_
.find(symndx
);
1442 if (p
!= this->local_got_offsets_
.end())
1443 p
->second
->set_offset(got_type
, got_offset
);
1446 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1447 std::pair
<Local_got_offsets::iterator
, bool> ins
=
1448 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
1449 gold_assert(ins
.second
);
1453 // Get the offset of input section SHNDX within its output section.
1454 // This is -1 if the input section requires a special mapping, such
1455 // as a merge section. The output section can be found in the
1456 // output_sections_ field of the parent class Relobj.
1458 get_output_section_offset(unsigned int shndx
) const
1460 gold_assert(shndx
< this->section_offsets_
.size());
1461 return this->section_offsets_
[shndx
];
1464 // Return the name of the symbol that spans the given offset in the
1465 // specified section in this object. This is used only for error
1466 // messages and is not particularly efficient.
1468 get_symbol_location_info(unsigned int shndx
, off_t offset
,
1469 Symbol_location_info
* info
);
1471 // Look for a kept section corresponding to the given discarded section,
1472 // and return its output address. This is used only for relocations in
1473 // debugging sections.
1475 map_to_kept_section(unsigned int shndx
, bool* found
) const;
1477 // Make section offset invalid. This is needed for relaxation.
1479 invalidate_section_offset(unsigned int shndx
)
1480 { this->do_invalidate_section_offset(shndx
); }
1487 // Read the symbols.
1489 do_read_symbols(Read_symbols_data
*);
1491 // Return the number of local symbols.
1493 do_local_symbol_count() const
1494 { return this->local_symbol_count_
; }
1496 // Lay out the input sections.
1498 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
1500 // Layout sections whose layout was deferred while waiting for
1501 // input files from a plugin.
1503 do_layout_deferred_sections(Layout
*);
1505 // Add the symbols to the symbol table.
1507 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
1511 do_read_relocs(Read_relocs_data
*);
1513 // Process the relocs to find list of referenced sections. Used only
1514 // during garbage collection.
1516 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1518 // Scan the relocs and adjust the symbol table.
1520 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1522 // Count the local symbols.
1524 do_count_local_symbols(Stringpool_template
<char>*,
1525 Stringpool_template
<char>*);
1527 // Finalize the local symbols.
1529 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
1531 // Set the offset where local dynamic symbol information will be stored.
1533 do_set_local_dynsym_indexes(unsigned int);
1535 // Set the offset where local dynamic symbol information will be stored.
1537 do_set_local_dynsym_offset(off_t
);
1539 // Relocate the input sections and write out the local symbols.
1541 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
1543 // Get the size of a section.
1545 do_section_size(unsigned int shndx
)
1546 { return this->elf_file_
.section_size(shndx
); }
1548 // Get the name of a section.
1550 do_section_name(unsigned int shndx
)
1551 { return this->elf_file_
.section_name(shndx
); }
1553 // Return the location of the contents of a section.
1555 do_section_contents(unsigned int shndx
)
1556 { return this->elf_file_
.section_contents(shndx
); }
1558 // Return section flags.
1560 do_section_flags(unsigned int shndx
);
1562 // Return section entsize.
1564 do_section_entsize(unsigned int shndx
);
1566 // Return section address.
1568 do_section_address(unsigned int shndx
)
1569 { return this->elf_file_
.section_addr(shndx
); }
1571 // Return section type.
1573 do_section_type(unsigned int shndx
)
1574 { return this->elf_file_
.section_type(shndx
); }
1576 // Return the section link field.
1578 do_section_link(unsigned int shndx
)
1579 { return this->elf_file_
.section_link(shndx
); }
1581 // Return the section info field.
1583 do_section_info(unsigned int shndx
)
1584 { return this->elf_file_
.section_info(shndx
); }
1586 // Return the section alignment.
1588 do_section_addralign(unsigned int shndx
)
1589 { return this->elf_file_
.section_addralign(shndx
); }
1591 // Return the Xindex structure to use.
1593 do_initialize_xindex();
1595 // Get symbol counts.
1597 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
1599 // Get the offset of a section.
1601 do_output_section_offset(unsigned int shndx
) const
1603 Address off
= this->get_output_section_offset(shndx
);
1604 if (off
== invalid_address
)
1609 // Set the offset of a section.
1611 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1613 gold_assert(shndx
< this->section_offsets_
.size());
1614 this->section_offsets_
[shndx
] = convert_types
<Address
, uint64_t>(off
);
1617 // Set the offset of a section to invalid_address.
1619 do_invalidate_section_offset(unsigned int shndx
)
1621 gold_assert(shndx
< this->section_offsets_
.size());
1622 this->section_offsets_
[shndx
] = invalid_address
;
1625 // Adjust a section index if necessary.
1627 adjust_shndx(unsigned int shndx
)
1629 if (shndx
>= elfcpp::SHN_LORESERVE
)
1630 shndx
+= this->elf_file_
.large_shndx_offset();
1634 // Initialize input to output maps for section symbols in merged
1637 initialize_input_to_output_maps();
1639 // Free the input to output maps for section symbols in merged
1642 free_input_to_output_maps();
1644 // Return symbol table section index.
1646 symtab_shndx() const
1647 { return this->symtab_shndx_
; }
1649 // Allow a child class to access the ELF file.
1650 elfcpp::Elf_file
<size
, big_endian
, Object
>*
1652 { return &this->elf_file_
; }
1654 // Allow a child class to access the local values.
1657 { return &this->local_values_
; }
1659 // Views and sizes when relocating.
1662 unsigned char* view
;
1663 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
1665 section_size_type view_size
;
1666 bool is_input_output_view
;
1667 bool is_postprocessing_view
;
1670 typedef std::vector
<View_size
> Views
;
1672 // This may be overriden by a child class.
1674 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1675 const unsigned char* pshdrs
, Views
* pviews
);
1679 typedef Sized_relobj
<size
, big_endian
> This
;
1680 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
1681 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1682 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1683 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
1685 // To keep track of discarded comdat sections, we need to map a member
1686 // section index to the object and section index of the corresponding
1688 struct Kept_comdat_section
1690 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
1691 : object(a_object
), shndx(a_shndx
)
1696 typedef std::map
<unsigned int, Kept_comdat_section
>
1697 Kept_comdat_section_table
;
1699 // Find the SHT_SYMTAB section, given the section headers.
1701 find_symtab(const unsigned char* pshdrs
);
1703 // Return whether SHDR has the right flags for a GNU style exception
1706 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
1708 // Return whether there is a section named .eh_frame which might be
1709 // a GNU style exception frame section.
1711 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
1712 section_size_type names_size
) const;
1714 // Whether to include a section group in the link.
1716 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
1717 const unsigned char*, const char *, section_size_type
,
1718 std::vector
<bool>*);
1720 // Whether to include a linkonce section in the link.
1722 include_linkonce_section(Layout
*, unsigned int, const char*,
1723 const elfcpp::Shdr
<size
, big_endian
>&);
1725 // Layout an input section.
1727 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
1728 typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
1729 unsigned int reloc_type
);
1731 // Write section data to the output file. Record the views and
1732 // sizes in VIEWS for use when relocating.
1734 write_sections(const unsigned char* pshdrs
, Output_file
*, Views
*);
1736 // Relocate the sections in the output file.
1738 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1739 const unsigned char* pshdrs
, Views
* pviews
)
1740 { this->do_relocate_sections(symtab
, layout
, pshdrs
, pviews
); }
1742 // Scan the input relocations for --emit-relocs.
1744 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
1745 const Read_relocs_data::Relocs_list::iterator
&);
1747 // Scan the input relocations for --emit-relocs, templatized on the
1748 // type of the relocation section.
1749 template<int sh_type
>
1751 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
1752 const unsigned char* plocal_syms
,
1753 const Read_relocs_data::Relocs_list::iterator
&,
1754 Relocatable_relocs
*);
1756 // Emit the relocs for --emit-relocs.
1758 emit_relocs(const Relocate_info
<size
, big_endian
>*, unsigned int,
1759 unsigned int sh_type
, const unsigned char* prelocs
,
1760 size_t reloc_count
, Output_section
*, Address output_offset
,
1761 unsigned char* view
, Address address
,
1762 section_size_type view_size
,
1763 unsigned char* reloc_view
, section_size_type reloc_view_size
);
1765 // Emit the relocs for --emit-relocs, templatized on the type of the
1766 // relocation section.
1767 template<int sh_type
>
1769 emit_relocs_reltype(const Relocate_info
<size
, big_endian
>*, unsigned int,
1770 const unsigned char* prelocs
, size_t reloc_count
,
1771 Output_section
*, Address output_offset
,
1772 unsigned char* view
, Address address
,
1773 section_size_type view_size
,
1774 unsigned char* reloc_view
,
1775 section_size_type reloc_view_size
);
1777 // A type shared by split_stack_adjust_reltype and find_functions.
1778 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
1780 // Check for -fsplit-stack routines calling non-split-stack routines.
1782 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
1783 unsigned int sh_type
, unsigned int shndx
,
1784 const unsigned char* prelocs
, size_t reloc_count
,
1785 unsigned char* view
, section_size_type view_size
,
1786 Reloc_symbol_changes
** reloc_map
);
1788 template<int sh_type
>
1790 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
1791 unsigned int shndx
, const unsigned char* prelocs
,
1792 size_t reloc_count
, unsigned char* view
,
1793 section_size_type view_size
,
1794 Reloc_symbol_changes
** reloc_map
);
1796 // Find all functions in a section.
1798 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
1801 // Write out the local symbols.
1803 write_local_symbols(Output_file
*,
1804 const Stringpool_template
<char>*,
1805 const Stringpool_template
<char>*,
1806 Output_symtab_xindex
*,
1807 Output_symtab_xindex
*);
1809 // Clear the local symbol information.
1811 clear_local_symbols()
1813 this->local_values_
.clear();
1814 this->local_got_offsets_
.clear();
1817 // Record a mapping from discarded section SHNDX to the corresponding
1820 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
1821 unsigned int kept_shndx
)
1823 Kept_comdat_section
kept(kept_object
, kept_shndx
);
1824 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
1827 // Find the kept section corresponding to the discarded section
1828 // SHNDX. Return true if found.
1830 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
1831 unsigned int* kept_shndx
) const
1833 typename
Kept_comdat_section_table::const_iterator p
=
1834 this->kept_comdat_sections_
.find(shndx
);
1835 if (p
== this->kept_comdat_sections_
.end())
1837 *kept_object
= p
->second
.object
;
1838 *kept_shndx
= p
->second
.shndx
;
1842 // The GOT offsets of local symbols. This map also stores GOT offsets
1843 // for tp-relative offsets for TLS symbols.
1844 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
1846 // The TLS GOT offsets of local symbols. The map stores the offsets
1847 // for either a single GOT entry that holds the module index of a TLS
1848 // symbol, or a pair of GOT entries containing the module index and
1849 // dtv-relative offset.
1850 struct Tls_got_entry
1852 Tls_got_entry(int got_offset
, bool have_pair
)
1853 : got_offset_(got_offset
),
1854 have_pair_(have_pair
)
1859 typedef Unordered_map
<unsigned int, Tls_got_entry
> Local_tls_got_offsets
;
1861 // Saved information for sections whose layout was deferred.
1862 struct Deferred_layout
1864 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1865 Deferred_layout(unsigned int shndx
, const char* name
,
1866 const unsigned char* pshdr
,
1867 unsigned int reloc_shndx
, unsigned int reloc_type
)
1868 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
1869 reloc_type_(reloc_type
)
1871 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
1873 unsigned int shndx_
;
1875 unsigned int reloc_shndx_
;
1876 unsigned int reloc_type_
;
1877 unsigned char shdr_data_
[shdr_size
];
1880 // General access to the ELF file.
1881 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
1882 // Index of SHT_SYMTAB section.
1883 unsigned int symtab_shndx_
;
1884 // The number of local symbols.
1885 unsigned int local_symbol_count_
;
1886 // The number of local symbols which go into the output file.
1887 unsigned int output_local_symbol_count_
;
1888 // The number of local symbols which go into the output file's dynamic
1890 unsigned int output_local_dynsym_count_
;
1891 // The entries in the symbol table for the external symbols.
1893 // Number of symbols defined in object file itself.
1894 size_t defined_count_
;
1895 // File offset for local symbols.
1896 off_t local_symbol_offset_
;
1897 // File offset for local dynamic symbols.
1898 off_t local_dynsym_offset_
;
1899 // Values of local symbols.
1900 Local_values local_values_
;
1901 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1902 // for TLS symbols, indexed by symbol number.
1903 Local_got_offsets local_got_offsets_
;
1904 // For each input section, the offset of the input section in its
1905 // output section. This is INVALID_ADDRESS if the input section requires a
1907 std::vector
<Address
> section_offsets_
;
1908 // Table mapping discarded comdat sections to corresponding kept sections.
1909 Kept_comdat_section_table kept_comdat_sections_
;
1910 // Whether this object has a GNU style .eh_frame section.
1912 // If this object has a GNU style .eh_frame section that is discarded in
1913 // output, record the index here. Otherwise it is -1U.
1914 unsigned int discarded_eh_frame_shndx_
;
1915 // The list of sections whose layout was deferred.
1916 std::vector
<Deferred_layout
> deferred_layout_
;
1919 // A class to manage the list of all objects.
1925 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
1928 // The type of the list of input relocateable objects.
1929 typedef std::vector
<Relobj
*> Relobj_list
;
1930 typedef Relobj_list::const_iterator Relobj_iterator
;
1932 // The type of the list of input dynamic objects.
1933 typedef std::vector
<Dynobj
*> Dynobj_list
;
1934 typedef Dynobj_list::const_iterator Dynobj_iterator
;
1936 // Add an object to the list. Return true if all is well, or false
1937 // if this object should be ignored.
1939 add_object(Object
*);
1941 // Start processing an archive.
1943 archive_start(Archive
*);
1945 // Stop processing an archive.
1947 archive_stop(Archive
*);
1949 // For each dynamic object, check whether we've seen all of its
1950 // explicit dependencies.
1952 check_dynamic_dependencies() const;
1954 // Return whether an object was found in the system library
1957 found_in_system_library_directory(const Object
*) const;
1959 // Print symbol counts.
1961 print_symbol_counts(const Symbol_table
*) const;
1963 // Iterate over all regular objects.
1966 relobj_begin() const
1967 { return this->relobj_list_
.begin(); }
1971 { return this->relobj_list_
.end(); }
1973 // Iterate over all dynamic objects.
1976 dynobj_begin() const
1977 { return this->dynobj_list_
.begin(); }
1981 { return this->dynobj_list_
.end(); }
1983 // Return whether we have seen any dynamic objects.
1986 { return !this->dynobj_list_
.empty(); }
1988 // Return the number of input objects.
1990 number_of_input_objects() const
1991 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
1994 Input_objects(const Input_objects
&);
1995 Input_objects
& operator=(const Input_objects
&);
1997 // The list of ordinary objects included in the link.
1998 Relobj_list relobj_list_
;
1999 // The list of dynamic objects included in the link.
2000 Dynobj_list dynobj_list_
;
2001 // SONAMEs that we have seen.
2002 Unordered_set
<std::string
> sonames_
;
2003 // Manage cross-references if requested.
2007 // Some of the information we pass to the relocation routines. We
2008 // group this together to avoid passing a dozen different arguments.
2010 template<int size
, bool big_endian
>
2011 struct Relocate_info
2014 const Symbol_table
* symtab
;
2016 const Layout
* layout
;
2017 // Object being relocated.
2018 Sized_relobj
<size
, big_endian
>* object
;
2019 // Section index of relocation section.
2020 unsigned int reloc_shndx
;
2021 // Section header of relocation section.
2022 const unsigned char* reloc_shdr
;
2023 // Section index of section being relocated.
2024 unsigned int data_shndx
;
2025 // Section header of data section.
2026 const unsigned char* data_shdr
;
2028 // Return a string showing the location of a relocation. This is
2029 // only used for error messages.
2031 location(size_t relnum
, off_t reloffset
) const;
2034 // Return whether INPUT_FILE contains an ELF object start at file
2035 // offset OFFSET. This sets *START to point to a view of the start of
2036 // the file. It sets *READ_SIZE to the number of bytes in the view.
2039 is_elf_object(Input_file
* input_file
, off_t offset
,
2040 const unsigned char** start
, int *read_size
);
2042 // Return an Object appropriate for the input file. P is BYTES long,
2043 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2044 // this sees an object the linker is not configured to support, it
2045 // sets *PUNCONFIGURED to true and returns NULL without giving an
2049 make_elf_object(const std::string
& name
, Input_file
*,
2050 off_t offset
, const unsigned char* p
,
2051 section_offset_type bytes
, bool* punconfigured
);
2053 } // end namespace gold
2055 #endif // !defined(GOLD_OBJECT_H)