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"
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 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 // Functions and types for the elfcpp::Elf_file interface. This
386 // permit us to use Object as the File template parameter for
389 // The View class is returned by view. It must support a single
390 // method, data(). This is trivial, because get_view does what we
395 View(const unsigned char* p
)
404 const unsigned char* p_
;
409 view(off_t file_offset
, section_size_type data_size
)
410 { return View(this->get_view(file_offset
, data_size
, true, true)); }
414 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
416 // A location in the file.
422 Location(off_t fo
, section_size_type ds
)
423 : file_offset(fo
), data_size(ds
)
427 // Get a View given a Location.
428 View
view(Location loc
)
429 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
431 // Get a view into the underlying file.
433 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
435 return this->input_file()->file().get_view(this->offset_
, start
, size
,
439 // Get a lasting view into the underlying file.
441 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
444 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
445 size
, aligned
, cache
);
448 // Read data from the underlying file.
450 read(off_t start
, section_size_type size
, void* p
)
451 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
453 // Read multiple data from the underlying file.
455 read_multiple(const File_read::Read_multiple
& rm
)
456 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
458 // Stop caching views in the underlying file.
460 clear_view_cache_marks()
461 { this->input_file()->file().clear_view_cache_marks(); }
463 // Get the number of global symbols defined by this object, and the
464 // number of the symbols whose final definition came from this
467 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
469 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
471 // Get the symbols defined in this object.
473 get_global_symbols() const
474 { return this->do_get_global_symbols(); }
476 // Return whether this object was found in a system directory.
478 is_in_system_directory() const
479 { return this->input_file()->is_in_system_directory(); }
481 // Return whether we found this object by searching a directory.
484 { return this->input_file()->will_search_for(); }
488 { return this->no_export_
; }
491 set_no_export(bool value
)
492 { this->no_export_
= value
; }
495 // Returns NULL for Objects that are not plugin objects. This method
496 // is overridden in the Pluginobj class.
501 // Read the symbols--implemented by child class.
503 do_read_symbols(Read_symbols_data
*) = 0;
505 // Lay out sections--implemented by child class.
507 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
509 // Add symbol information to the global symbol table--implemented by
512 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
514 // Return the location of the contents of a section. Implemented by
517 do_section_contents(unsigned int shndx
) = 0;
519 // Get the size of a section--implemented by child class.
521 do_section_size(unsigned int shndx
) = 0;
523 // Get the name of a section--implemented by child class.
525 do_section_name(unsigned int shndx
) = 0;
527 // Get section flags--implemented by child class.
529 do_section_flags(unsigned int shndx
) = 0;
531 // Get section entsize--implemented by child class.
533 do_section_entsize(unsigned int shndx
) = 0;
535 // Get section address--implemented by child class.
537 do_section_address(unsigned int shndx
) = 0;
539 // Get section type--implemented by child class.
541 do_section_type(unsigned int shndx
) = 0;
543 // Get section link field--implemented by child class.
545 do_section_link(unsigned int shndx
) = 0;
547 // Get section info field--implemented by child class.
549 do_section_info(unsigned int shndx
) = 0;
551 // Get section alignment--implemented by child class.
553 do_section_addralign(unsigned int shndx
) = 0;
555 // Return the Xindex structure to use.
557 do_initialize_xindex() = 0;
559 // Implement get_global_symbol_counts--implemented by child class.
561 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
563 virtual const Symbols
*
564 do_get_global_symbols() const = 0;
566 // Set the number of sections.
569 { this->shnum_
= shnum
; }
571 // Functions used by both Sized_relobj and Sized_dynobj.
573 // Read the section data into a Read_symbols_data object.
574 template<int size
, bool big_endian
>
576 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
579 // Let the child class initialize the xindex object directly.
581 set_xindex(Xindex
* xindex
)
583 gold_assert(this->xindex_
== NULL
);
584 this->xindex_
= xindex
;
587 // If NAME is the name of a special .gnu.warning section, arrange
588 // for the warning to be issued. SHNDX is the section index.
589 // Return whether it is a warning section.
591 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
594 // If NAME is the name of the special section which indicates that
595 // this object was compiled with -fstack-split, mark it accordingly,
596 // and return true. Otherwise return false.
598 handle_split_stack_section(const char* name
);
601 // This class may not be copied.
602 Object(const Object
&);
603 Object
& operator=(const Object
&);
605 // Name of object as printed to user.
607 // For reading the file.
608 Input_file
* input_file_
;
609 // Offset within the file--0 for an object file, non-0 for an
612 // Number of input sections.
614 // Whether this is a dynamic object.
615 bool is_dynamic_
: 1;
616 // Whether this object is needed. This is only set for dynamic
617 // objects, and means that the object defined a symbol which was
618 // used by a reference from a regular object.
620 // Whether this object was compiled with -fsplit-stack.
621 bool uses_split_stack_
: 1;
622 // Whether this object contains any functions compiled with the
623 // no_split_stack attribute.
624 bool has_no_split_stack_
: 1;
625 // True if exclude this object from automatic symbol export.
626 // This is used only for archive objects.
628 // Many sections for objects with more than SHN_LORESERVE sections.
632 // A regular object (ET_REL). This is an abstract base class itself.
633 // The implementation is the template class Sized_relobj.
635 class Relobj
: public Object
638 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
639 : Object(name
, input_file
, false, offset
),
641 map_to_relocatable_relocs_(NULL
),
642 object_merge_map_(NULL
),
643 relocs_must_follow_section_writes_(false),
647 // During garbage collection, the Read_symbols_data pass for
648 // each object is stored as layout needs to be done after
652 { return this->sd_
; }
654 // Decides which section names have to be included in the worklist
657 is_section_name_included(const char *name
);
660 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
661 unsigned int section_header_size
);
664 set_symbols_data(Symbols_data
* sd
)
667 // During garbage collection, the Read_relocs pass for all objects
668 // is done before scanning the relocs. In that case, this->rd_ is
669 // used to store the information from Read_relocs for each object.
670 // This data is also used to compute the list of relevant sections.
673 { return this->rd_
; }
676 set_relocs_data(Read_relocs_data
* rd
)
680 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
684 read_relocs(Read_relocs_data
* rd
)
685 { return this->do_read_relocs(rd
); }
687 // Process the relocs, during garbage collection only.
689 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
690 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
692 // Scan the relocs and adjust the symbol table.
694 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
695 { return this->do_scan_relocs(symtab
, layout
, rd
); }
697 // The number of local symbols in the input symbol table.
699 local_symbol_count() const
700 { return this->do_local_symbol_count(); }
702 // Initial local symbol processing: count the number of local symbols
703 // in the output symbol table and dynamic symbol table; add local symbol
704 // names to *POOL and *DYNPOOL.
706 count_local_symbols(Stringpool_template
<char>* pool
,
707 Stringpool_template
<char>* dynpool
)
708 { return this->do_count_local_symbols(pool
, dynpool
); }
710 // Set the values of the local symbols, set the output symbol table
711 // indexes for the local variables, and set the offset where local
712 // symbol information will be stored. Returns the new local symbol index.
714 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
715 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
717 // Set the output dynamic symbol table indexes for the local variables.
719 set_local_dynsym_indexes(unsigned int index
)
720 { return this->do_set_local_dynsym_indexes(index
); }
722 // Set the offset where local dynamic symbol information will be stored.
724 set_local_dynsym_offset(off_t off
)
725 { return this->do_set_local_dynsym_offset(off
); }
727 // Relocate the input sections and write out the local symbols.
729 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
730 { return this->do_relocate(symtab
, layout
, of
); }
732 // Return whether an input section is being included in the link.
734 is_section_included(unsigned int shndx
) const
736 gold_assert(shndx
< this->output_sections_
.size());
737 return this->output_sections_
[shndx
] != NULL
;
740 // Given a section index, return the corresponding Output_section.
741 // The return value will be NULL if the section is not included in
744 output_section(unsigned int shndx
) const
746 gold_assert(shndx
< this->output_sections_
.size());
747 return this->output_sections_
[shndx
];
750 // The the output section of the input section with index SHNDX.
751 // This is only used currently to remove a section from the link in
754 set_output_section(unsigned int shndx
, Output_section
* os
)
756 gold_assert(shndx
< this->output_sections_
.size());
757 this->output_sections_
[shndx
] = os
;
760 // Given a section index, return the offset in the Output_section.
761 // The return value will be -1U if the section is specially mapped,
762 // such as a merge section.
764 output_section_offset(unsigned int shndx
) const
765 { return this->do_output_section_offset(shndx
); }
767 // Set the offset of an input section within its output section.
769 set_section_offset(unsigned int shndx
, uint64_t off
)
770 { this->do_set_section_offset(shndx
, off
); }
772 // Return true if we need to wait for output sections to be written
773 // before we can apply relocations. This is true if the object has
774 // any relocations for sections which require special handling, such
775 // as the exception frame section.
777 relocs_must_follow_section_writes() const
778 { return this->relocs_must_follow_section_writes_
; }
780 // Return the object merge map.
783 { return this->object_merge_map_
; }
785 // Set the object merge map.
787 set_merge_map(Object_merge_map
* object_merge_map
)
789 gold_assert(this->object_merge_map_
== NULL
);
790 this->object_merge_map_
= object_merge_map
;
793 // Record the relocatable reloc info for an input reloc section.
795 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
797 gold_assert(reloc_shndx
< this->shnum());
798 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
801 // Get the relocatable reloc info for an input reloc section.
803 relocatable_relocs(unsigned int reloc_shndx
)
805 gold_assert(reloc_shndx
< this->shnum());
806 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
809 // Layout sections whose layout was deferred while waiting for
810 // input files from a plugin.
812 layout_deferred_sections(Layout
* layout
)
813 { this->do_layout_deferred_sections(layout
); }
816 // The output section to be used for each input section, indexed by
817 // the input section number. The output section is NULL if the
818 // input section is to be discarded.
819 typedef std::vector
<Output_section
*> Output_sections
;
821 // Read the relocs--implemented by child class.
823 do_read_relocs(Read_relocs_data
*) = 0;
825 // Process the relocs--implemented by child class.
827 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
829 // Scan the relocs--implemented by child class.
831 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
833 // Return the number of local symbols--implemented by child class.
835 do_local_symbol_count() const = 0;
837 // Count local symbols--implemented by child class.
839 do_count_local_symbols(Stringpool_template
<char>*,
840 Stringpool_template
<char>*) = 0;
842 // Finalize the local symbols. Set the output symbol table indexes
843 // for the local variables, and set the offset where local symbol
844 // information will be stored.
846 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
848 // Set the output dynamic symbol table indexes for the local variables.
850 do_set_local_dynsym_indexes(unsigned int) = 0;
852 // Set the offset where local dynamic symbol information will be stored.
854 do_set_local_dynsym_offset(off_t
) = 0;
856 // Relocate the input sections and write out the local
857 // symbols--implemented by child class.
859 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
861 // Get the offset of a section--implemented by child class.
863 do_output_section_offset(unsigned int shndx
) const = 0;
865 // Set the offset of a section--implemented by child class.
867 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
869 // Layout sections whose layout was deferred while waiting for
870 // input files from a plugin--implemented by child class.
872 do_layout_deferred_sections(Layout
*) = 0;
874 // Return the vector mapping input sections to output sections.
877 { return this->output_sections_
; }
879 const Output_sections
&
880 output_sections() const
881 { return this->output_sections_
; }
883 // Set the size of the relocatable relocs array.
885 size_relocatable_relocs()
887 this->map_to_relocatable_relocs_
=
888 new std::vector
<Relocatable_relocs
*>(this->shnum());
891 // Record that we must wait for the output sections to be written
892 // before applying relocations.
894 set_relocs_must_follow_section_writes()
895 { this->relocs_must_follow_section_writes_
= true; }
898 // Mapping from input sections to output section.
899 Output_sections output_sections_
;
900 // Mapping from input section index to the information recorded for
901 // the relocations. This is only used for a relocatable link.
902 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
903 // Mappings for merge sections. This is managed by the code in the
905 Object_merge_map
* object_merge_map_
;
906 // Whether we need to wait for output sections to be written before
907 // we can apply relocations.
908 bool relocs_must_follow_section_writes_
;
909 // Used to store the relocs data computed by the Read_relocs pass.
910 // Used during garbage collection of unused sections.
911 Read_relocs_data
* rd_
;
912 // Used to store the symbols data computed by the Read_symbols pass.
913 // Again used during garbage collection when laying out referenced
915 gold::Symbols_data
*sd_
;
918 // This class is used to handle relocations against a section symbol
919 // in an SHF_MERGE section. For such a symbol, we need to know the
920 // addend of the relocation before we can determine the final value.
921 // The addend gives us the location in the input section, and we can
922 // determine how it is mapped to the output section. For a
923 // non-section symbol, we apply the addend to the final value of the
924 // symbol; that is done in finalize_local_symbols, and does not use
928 class Merged_symbol_value
931 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
933 // We use a hash table to map offsets in the input section to output
935 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
937 Merged_symbol_value(Value input_value
, Value output_start_address
)
938 : input_value_(input_value
), output_start_address_(output_start_address
),
942 // Initialize the hash table.
944 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
946 // Release the hash table to save space.
948 free_input_to_output_map()
949 { this->output_addresses_
.clear(); }
951 // Get the output value corresponding to an addend. The object and
952 // input section index are passed in because the caller will have
953 // them; otherwise we could store them here.
955 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
957 // This is a relocation against a section symbol. ADDEND is the
958 // offset in the section. The result should be the start of some
959 // merge area. If the object file wants something else, it should
960 // use a regular symbol rather than a section symbol.
961 // Unfortunately, PR 6658 shows a case in which the object file
962 // refers to the section symbol, but uses a negative ADDEND to
963 // compensate for a PC relative reloc. We can't handle the
964 // general case. However, we can handle the special case of a
965 // negative addend, by assuming that it refers to the start of the
966 // section. Of course, that means that we have to guess when
967 // ADDEND is negative. It is normal to see a 32-bit value here
968 // even when the template parameter size is 64, as 64-bit object
969 // file formats have 32-bit relocations. We know this is a merge
970 // section, so we know it has to fit into memory. So we assume
971 // that we won't see a value larger than a large 32-bit unsigned
972 // value. This will break objects with very very large merge
973 // sections; they probably break in other ways anyhow.
974 Value input_offset
= this->input_value_
;
975 if (addend
< 0xffffff00)
977 input_offset
+= addend
;
980 typename
Output_addresses::const_iterator p
=
981 this->output_addresses_
.find(input_offset
);
982 if (p
!= this->output_addresses_
.end())
983 return p
->second
+ addend
;
985 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
990 // Get the output value for an input offset if we couldn't find it
991 // in the hash table.
993 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
994 Value input_offset
) const;
996 // The value of the section symbol in the input file. This is
997 // normally zero, but could in principle be something else.
999 // The start address of this merged section in the output file.
1000 Value output_start_address_
;
1001 // A hash table which maps offsets in the input section to output
1002 // addresses. This only maps specific offsets, not all offsets.
1003 Output_addresses output_addresses_
;
1006 // This POD class is holds the value of a symbol. This is used for
1007 // local symbols, and for all symbols during relocation processing.
1008 // For special sections, such as SHF_MERGE sections, this calls a
1009 // function to get the final symbol value.
1015 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1018 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1019 is_ordinary_shndx_(false), is_section_symbol_(false),
1020 is_tls_symbol_(false), has_output_value_(true)
1021 { this->u_
.value
= 0; }
1023 // Get the value of this symbol. OBJECT is the object in which this
1024 // symbol is defined, and ADDEND is an addend to add to the value.
1025 template<bool big_endian
>
1027 value(const Sized_relobj
<size
, big_endian
>* object
, Value addend
) const
1029 if (this->has_output_value_
)
1030 return this->u_
.value
+ addend
;
1033 gold_assert(this->is_ordinary_shndx_
);
1034 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1039 // Set the value of this symbol in the output symbol table.
1041 set_output_value(Value value
)
1042 { this->u_
.value
= value
; }
1044 // For a section symbol in a merged section, we need more
1047 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1049 gold_assert(this->is_section_symbol_
);
1050 this->has_output_value_
= false;
1051 this->u_
.merged_symbol_value
= msv
;
1054 // Initialize the input to output map for a section symbol in a
1055 // merged section. We also initialize the value of a non-section
1056 // symbol in a merged section.
1058 initialize_input_to_output_map(const Relobj
* object
)
1060 if (!this->has_output_value_
)
1062 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1063 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1064 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1068 // Free the input to output map for a section symbol in a merged
1071 free_input_to_output_map()
1073 if (!this->has_output_value_
)
1074 this->u_
.merged_symbol_value
->free_input_to_output_map();
1077 // Set the value of the symbol from the input file. This is only
1078 // called by count_local_symbols, to communicate the value to
1079 // finalize_local_symbols.
1081 set_input_value(Value value
)
1082 { this->u_
.value
= value
; }
1084 // Return the input value. This is only called by
1085 // finalize_local_symbols and (in special cases) relocate_section.
1088 { return this->u_
.value
; }
1090 // Return whether we have set the index in the output symbol table
1093 is_output_symtab_index_set() const
1095 return (this->output_symtab_index_
!= 0
1096 && this->output_symtab_index_
!= -2U);
1099 // Return whether this symbol may be discarded from the normal
1102 may_be_discarded_from_output_symtab() const
1104 gold_assert(!this->is_output_symtab_index_set());
1105 return this->output_symtab_index_
!= -2U;
1108 // Return whether this symbol has an entry in the output symbol
1111 has_output_symtab_entry() const
1113 gold_assert(this->is_output_symtab_index_set());
1114 return this->output_symtab_index_
!= -1U;
1117 // Return the index in the output symbol table.
1119 output_symtab_index() const
1121 gold_assert(this->is_output_symtab_index_set()
1122 && this->output_symtab_index_
!= -1U);
1123 return this->output_symtab_index_
;
1126 // Set the index in the output symbol table.
1128 set_output_symtab_index(unsigned int i
)
1130 gold_assert(!this->is_output_symtab_index_set());
1131 gold_assert(i
!= 0 && i
!= -1U && i
!= -2U);
1132 this->output_symtab_index_
= i
;
1135 // Record that this symbol should not go into the output symbol
1138 set_no_output_symtab_entry()
1140 gold_assert(this->output_symtab_index_
== 0);
1141 this->output_symtab_index_
= -1U;
1144 // Record that this symbol must go into the output symbol table,
1145 // because it there is a relocation that uses it.
1147 set_must_have_output_symtab_entry()
1149 gold_assert(!this->is_output_symtab_index_set());
1150 this->output_symtab_index_
= -2U;
1153 // Set the index in the output dynamic symbol table.
1155 set_needs_output_dynsym_entry()
1157 gold_assert(!this->is_section_symbol());
1158 this->output_dynsym_index_
= 0;
1161 // Return whether this symbol should go into the dynamic symbol
1164 needs_output_dynsym_entry() const
1166 return this->output_dynsym_index_
!= -1U;
1169 // Return whether this symbol has an entry in the dynamic symbol
1172 has_output_dynsym_entry() const
1174 gold_assert(this->output_dynsym_index_
!= 0);
1175 return this->output_dynsym_index_
!= -1U;
1178 // Record that this symbol should go into the dynamic symbol table.
1180 set_output_dynsym_index(unsigned int i
)
1182 gold_assert(this->output_dynsym_index_
== 0);
1183 gold_assert(i
!= 0 && i
!= -1U);
1184 this->output_dynsym_index_
= i
;
1187 // Return the index in the output dynamic symbol table.
1189 output_dynsym_index() const
1191 gold_assert(this->output_dynsym_index_
!= 0
1192 && this->output_dynsym_index_
!= -1U);
1193 return this->output_dynsym_index_
;
1196 // Set the index of the input section in the input file.
1198 set_input_shndx(unsigned int i
, bool is_ordinary
)
1200 this->input_shndx_
= i
;
1201 // input_shndx_ field is a bitfield, so make sure that the value
1203 gold_assert(this->input_shndx_
== i
);
1204 this->is_ordinary_shndx_
= is_ordinary
;
1207 // Return the index of the input section in the input file.
1209 input_shndx(bool* is_ordinary
) const
1211 *is_ordinary
= this->is_ordinary_shndx_
;
1212 return this->input_shndx_
;
1215 // Whether this is a section symbol.
1217 is_section_symbol() const
1218 { return this->is_section_symbol_
; }
1220 // Record that this is a section symbol.
1222 set_is_section_symbol()
1224 gold_assert(!this->needs_output_dynsym_entry());
1225 this->is_section_symbol_
= true;
1228 // Record that this is a TLS symbol.
1231 { this->is_tls_symbol_
= true; }
1233 // Return TRUE if this is a TLS symbol.
1235 is_tls_symbol() const
1236 { return this->is_tls_symbol_
; }
1239 // The index of this local symbol in the output symbol table. This
1240 // will be 0 if no value has been assigned yet, and the symbol may
1241 // be omitted. This will be -1U if the symbol should not go into
1242 // the symbol table. This will be -2U if the symbol must go into
1243 // the symbol table, but no index has been assigned yet.
1244 unsigned int output_symtab_index_
;
1245 // The index of this local symbol in the dynamic symbol table. This
1246 // will be -1U if the symbol should not go into the symbol table.
1247 unsigned int output_dynsym_index_
;
1248 // The section index in the input file in which this symbol is
1250 unsigned int input_shndx_
: 28;
1251 // Whether the section index is an ordinary index, not a special
1253 bool is_ordinary_shndx_
: 1;
1254 // Whether this is a STT_SECTION symbol.
1255 bool is_section_symbol_
: 1;
1256 // Whether this is a STT_TLS symbol.
1257 bool is_tls_symbol_
: 1;
1258 // Whether this symbol has a value for the output file. This is
1259 // normally set to true during Layout::finalize, by
1260 // finalize_local_symbols. It will be false for a section symbol in
1261 // a merge section, as for such symbols we can not determine the
1262 // value to use in a relocation until we see the addend.
1263 bool has_output_value_
: 1;
1266 // This is used if has_output_value_ is true. Between
1267 // count_local_symbols and finalize_local_symbols, this is the
1268 // value in the input file. After finalize_local_symbols, it is
1269 // the value in the output file.
1271 // This is used if has_output_value_ is false. It points to the
1272 // information we need to get the value for a merge section.
1273 Merged_symbol_value
<size
>* merged_symbol_value
;
1277 // A GOT offset list. A symbol may have more than one GOT offset
1278 // (e.g., when mixing modules compiled with two different TLS models),
1279 // but will usually have at most one. GOT_TYPE identifies the type of
1280 // GOT entry; its values are specific to each target.
1282 class Got_offset_list
1286 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
1289 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
1290 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
1295 if (this->got_next_
!= NULL
)
1297 delete this->got_next_
;
1298 this->got_next_
= NULL
;
1302 // Initialize the fields to their default values.
1306 this->got_type_
= -1U;
1307 this->got_offset_
= 0;
1308 this->got_next_
= NULL
;
1311 // Set the offset for the GOT entry of type GOT_TYPE.
1313 set_offset(unsigned int got_type
, unsigned int got_offset
)
1315 if (this->got_type_
== -1U)
1317 this->got_type_
= got_type
;
1318 this->got_offset_
= got_offset
;
1322 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1324 if (g
->got_type_
== got_type
)
1326 g
->got_offset_
= got_offset
;
1330 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1331 g
->got_next_
= this->got_next_
;
1332 this->got_next_
= g
;
1336 // Return the offset for a GOT entry of type GOT_TYPE.
1338 get_offset(unsigned int got_type
) const
1340 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
1342 if (g
->got_type_
== got_type
)
1343 return g
->got_offset_
;
1349 unsigned int got_type_
;
1350 unsigned int got_offset_
;
1351 Got_offset_list
* got_next_
;
1354 // This type is used to modify relocations for -fsplit-stack. It is
1355 // indexed by relocation index, and means that the relocation at that
1356 // index should use the symbol from the vector, rather than the one
1357 // indicated by the relocation.
1359 class Reloc_symbol_changes
1362 Reloc_symbol_changes(size_t count
)
1367 set(size_t i
, Symbol
* sym
)
1368 { this->vec_
[i
] = sym
; }
1371 operator[](size_t i
) const
1372 { return this->vec_
[i
]; }
1375 std::vector
<Symbol
*> vec_
;
1378 // A regular object file. This is size and endian specific.
1380 template<int size
, bool big_endian
>
1381 class Sized_relobj
: public Relobj
1384 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1385 typedef std::vector
<Symbol
*> Symbols
;
1386 typedef std::vector
<Symbol_value
<size
> > Local_values
;
1388 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1390 Sized_relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
,
1391 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
1395 // Checks if the offset of input section SHNDX within its output
1396 // section is invalid.
1398 is_output_section_offset_invalid(unsigned int shndx
) const
1399 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1401 // Set up the object file based on TARGET.
1404 { this->do_setup(); }
1406 // Return the number of symbols. This is only valid after
1407 // Object::add_symbols has been called.
1409 symbol_count() const
1410 { return this->local_symbol_count_
+ this->symbols_
.size(); }
1412 // If SYM is the index of a global symbol in the object file's
1413 // symbol table, return the Symbol object. Otherwise, return NULL.
1415 global_symbol(unsigned int sym
) const
1417 if (sym
>= this->local_symbol_count_
)
1419 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
1420 return this->symbols_
[sym
- this->local_symbol_count_
];
1425 // Return the section index of symbol SYM. Set *VALUE to its value
1426 // in the object file. Set *IS_ORDINARY if this is an ordinary
1427 // section index, not a special code between SHN_LORESERVE and
1428 // SHN_HIRESERVE. Note that for a symbol which is not defined in
1429 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
1430 // it will not return the final value of the symbol in the link.
1432 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
1434 // Return a pointer to the Symbol_value structure which holds the
1435 // value of a local symbol.
1436 const Symbol_value
<size
>*
1437 local_symbol(unsigned int sym
) const
1439 gold_assert(sym
< this->local_values_
.size());
1440 return &this->local_values_
[sym
];
1443 // Return the index of local symbol SYM in the ordinary symbol
1444 // table. A value of -1U means that the symbol is not being output.
1446 symtab_index(unsigned int sym
) const
1448 gold_assert(sym
< this->local_values_
.size());
1449 return this->local_values_
[sym
].output_symtab_index();
1452 // Return the index of local symbol SYM in the dynamic symbol
1453 // table. A value of -1U means that the symbol is not being output.
1455 dynsym_index(unsigned int sym
) const
1457 gold_assert(sym
< this->local_values_
.size());
1458 return this->local_values_
[sym
].output_dynsym_index();
1461 // Return the input section index of local symbol SYM.
1463 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
1465 gold_assert(sym
< this->local_values_
.size());
1466 return this->local_values_
[sym
].input_shndx(is_ordinary
);
1469 // Record that local symbol SYM must be in the output symbol table.
1471 set_must_have_output_symtab_entry(unsigned int sym
)
1473 gold_assert(sym
< this->local_values_
.size());
1474 this->local_values_
[sym
].set_must_have_output_symtab_entry();
1477 // Record that local symbol SYM needs a dynamic symbol entry.
1479 set_needs_output_dynsym_entry(unsigned int sym
)
1481 gold_assert(sym
< this->local_values_
.size());
1482 this->local_values_
[sym
].set_needs_output_dynsym_entry();
1485 // Return whether the local symbol SYMNDX has a GOT offset.
1486 // For TLS symbols, the GOT entry will hold its tp-relative offset.
1488 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1490 Local_got_offsets::const_iterator p
=
1491 this->local_got_offsets_
.find(symndx
);
1492 return (p
!= this->local_got_offsets_
.end()
1493 && p
->second
->get_offset(got_type
) != -1U);
1496 // Return the GOT offset of the local symbol SYMNDX.
1498 local_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 gold_assert(p
!= this->local_got_offsets_
.end());
1503 unsigned int off
= p
->second
->get_offset(got_type
);
1504 gold_assert(off
!= -1U);
1508 // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
1510 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1511 unsigned int got_offset
)
1513 Local_got_offsets::const_iterator p
=
1514 this->local_got_offsets_
.find(symndx
);
1515 if (p
!= this->local_got_offsets_
.end())
1516 p
->second
->set_offset(got_type
, got_offset
);
1519 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1520 std::pair
<Local_got_offsets::iterator
, bool> ins
=
1521 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
1522 gold_assert(ins
.second
);
1526 // Get the offset of input section SHNDX within its output section.
1527 // This is -1 if the input section requires a special mapping, such
1528 // as a merge section. The output section can be found in the
1529 // output_sections_ field of the parent class Relobj.
1531 get_output_section_offset(unsigned int shndx
) const
1533 gold_assert(shndx
< this->section_offsets_
.size());
1534 return this->section_offsets_
[shndx
];
1537 // Return the name of the symbol that spans the given offset in the
1538 // specified section in this object. This is used only for error
1539 // messages and is not particularly efficient.
1541 get_symbol_location_info(unsigned int shndx
, off_t offset
,
1542 Symbol_location_info
* info
);
1544 // Look for a kept section corresponding to the given discarded section,
1545 // and return its output address. This is used only for relocations in
1546 // debugging sections.
1548 map_to_kept_section(unsigned int shndx
, bool* found
) const;
1555 // Read the symbols.
1557 do_read_symbols(Read_symbols_data
*);
1559 // Return the number of local symbols.
1561 do_local_symbol_count() const
1562 { return this->local_symbol_count_
; }
1564 // Lay out the input sections.
1566 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
1568 // Layout sections whose layout was deferred while waiting for
1569 // input files from a plugin.
1571 do_layout_deferred_sections(Layout
*);
1573 // Add the symbols to the symbol table.
1575 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
1579 do_read_relocs(Read_relocs_data
*);
1581 // Process the relocs to find list of referenced sections. Used only
1582 // during garbage collection.
1584 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1586 // Scan the relocs and adjust the symbol table.
1588 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
1590 // Count the local symbols.
1592 do_count_local_symbols(Stringpool_template
<char>*,
1593 Stringpool_template
<char>*);
1595 // Finalize the local symbols.
1597 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
1599 // Set the offset where local dynamic symbol information will be stored.
1601 do_set_local_dynsym_indexes(unsigned int);
1603 // Set the offset where local dynamic symbol information will be stored.
1605 do_set_local_dynsym_offset(off_t
);
1607 // Relocate the input sections and write out the local symbols.
1609 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
1611 // Get the size of a section.
1613 do_section_size(unsigned int shndx
)
1614 { return this->elf_file_
.section_size(shndx
); }
1616 // Get the name of a section.
1618 do_section_name(unsigned int shndx
)
1619 { return this->elf_file_
.section_name(shndx
); }
1621 // Return the location of the contents of a section.
1623 do_section_contents(unsigned int shndx
)
1624 { return this->elf_file_
.section_contents(shndx
); }
1626 // Return section flags.
1628 do_section_flags(unsigned int shndx
);
1630 // Return section entsize.
1632 do_section_entsize(unsigned int shndx
);
1634 // Return section address.
1636 do_section_address(unsigned int shndx
)
1637 { return this->elf_file_
.section_addr(shndx
); }
1639 // Return section type.
1641 do_section_type(unsigned int shndx
)
1642 { return this->elf_file_
.section_type(shndx
); }
1644 // Return the section link field.
1646 do_section_link(unsigned int shndx
)
1647 { return this->elf_file_
.section_link(shndx
); }
1649 // Return the section info field.
1651 do_section_info(unsigned int shndx
)
1652 { return this->elf_file_
.section_info(shndx
); }
1654 // Return the section alignment.
1656 do_section_addralign(unsigned int shndx
)
1657 { return this->elf_file_
.section_addralign(shndx
); }
1659 // Return the Xindex structure to use.
1661 do_initialize_xindex();
1663 // Get symbol counts.
1665 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
1667 // Get the global symbols.
1669 do_get_global_symbols() const
1670 { return &this->symbols_
; }
1672 // Get the offset of a section.
1674 do_output_section_offset(unsigned int shndx
) const
1676 Address off
= this->get_output_section_offset(shndx
);
1677 if (off
== invalid_address
)
1682 // Set the offset of a section.
1684 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1686 gold_assert(shndx
< this->section_offsets_
.size());
1687 this->section_offsets_
[shndx
] =
1688 (off
== static_cast<uint64_t>(-1)
1690 : convert_types
<Address
, uint64_t>(off
));
1693 // Adjust a section index if necessary.
1695 adjust_shndx(unsigned int shndx
)
1697 if (shndx
>= elfcpp::SHN_LORESERVE
)
1698 shndx
+= this->elf_file_
.large_shndx_offset();
1702 // Initialize input to output maps for section symbols in merged
1705 initialize_input_to_output_maps();
1707 // Free the input to output maps for section symbols in merged
1710 free_input_to_output_maps();
1712 // Return symbol table section index.
1714 symtab_shndx() const
1715 { return this->symtab_shndx_
; }
1717 // Allow a child class to access the ELF file.
1718 elfcpp::Elf_file
<size
, big_endian
, Object
>*
1720 { return &this->elf_file_
; }
1722 // Allow a child class to access the local values.
1725 { return &this->local_values_
; }
1727 // Views and sizes when relocating.
1730 unsigned char* view
;
1731 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
1733 section_size_type view_size
;
1734 bool is_input_output_view
;
1735 bool is_postprocessing_view
;
1738 typedef std::vector
<View_size
> Views
;
1740 // This may be overriden by a child class.
1742 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1743 const unsigned char* pshdrs
, Views
* pviews
);
1745 // Allow a child to set output local symbol count.
1747 set_output_local_symbol_count(unsigned int value
)
1748 { this->output_local_symbol_count_
= value
; }
1752 typedef Sized_relobj
<size
, big_endian
> This
;
1753 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
1754 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1755 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1756 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
1758 // To keep track of discarded comdat sections, we need to map a member
1759 // section index to the object and section index of the corresponding
1761 struct Kept_comdat_section
1763 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
1764 : object(a_object
), shndx(a_shndx
)
1769 typedef std::map
<unsigned int, Kept_comdat_section
>
1770 Kept_comdat_section_table
;
1772 // Find the SHT_SYMTAB section, given the section headers.
1774 find_symtab(const unsigned char* pshdrs
);
1776 // Return whether SHDR has the right flags for a GNU style exception
1779 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
1781 // Return whether there is a section named .eh_frame which might be
1782 // a GNU style exception frame section.
1784 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
1785 section_size_type names_size
) const;
1787 // Whether to include a section group in the link.
1789 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
1790 const unsigned char*, const char *, section_size_type
,
1791 std::vector
<bool>*);
1793 // Whether to include a linkonce section in the link.
1795 include_linkonce_section(Layout
*, unsigned int, const char*,
1796 const elfcpp::Shdr
<size
, big_endian
>&);
1798 // Layout an input section.
1800 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
1801 typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
1802 unsigned int reloc_type
);
1804 // Write section data to the output file. Record the views and
1805 // sizes in VIEWS for use when relocating.
1807 write_sections(const unsigned char* pshdrs
, Output_file
*, Views
*);
1809 // Relocate the sections in the output file.
1811 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
1812 const unsigned char* pshdrs
, Views
* pviews
)
1813 { this->do_relocate_sections(symtab
, layout
, pshdrs
, pviews
); }
1815 // Scan the input relocations for --emit-relocs.
1817 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
1818 const Read_relocs_data::Relocs_list::iterator
&);
1820 // Scan the input relocations for --emit-relocs, templatized on the
1821 // type of the relocation section.
1822 template<int sh_type
>
1824 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
1825 const unsigned char* plocal_syms
,
1826 const Read_relocs_data::Relocs_list::iterator
&,
1827 Relocatable_relocs
*);
1829 // Emit the relocs for --emit-relocs.
1831 emit_relocs(const Relocate_info
<size
, big_endian
>*, unsigned int,
1832 unsigned int sh_type
, const unsigned char* prelocs
,
1833 size_t reloc_count
, Output_section
*, Address output_offset
,
1834 unsigned char* view
, Address address
,
1835 section_size_type view_size
,
1836 unsigned char* reloc_view
, section_size_type reloc_view_size
);
1838 // Emit the relocs for --emit-relocs, templatized on the type of the
1839 // relocation section.
1840 template<int sh_type
>
1842 emit_relocs_reltype(const Relocate_info
<size
, big_endian
>*, unsigned int,
1843 const unsigned char* prelocs
, size_t reloc_count
,
1844 Output_section
*, Address output_offset
,
1845 unsigned char* view
, Address address
,
1846 section_size_type view_size
,
1847 unsigned char* reloc_view
,
1848 section_size_type reloc_view_size
);
1850 // A type shared by split_stack_adjust_reltype and find_functions.
1851 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
1853 // Check for -fsplit-stack routines calling non-split-stack routines.
1855 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
1856 unsigned int sh_type
, unsigned int shndx
,
1857 const unsigned char* prelocs
, size_t reloc_count
,
1858 unsigned char* view
, section_size_type view_size
,
1859 Reloc_symbol_changes
** reloc_map
);
1861 template<int sh_type
>
1863 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
1864 unsigned int shndx
, const unsigned char* prelocs
,
1865 size_t reloc_count
, unsigned char* view
,
1866 section_size_type view_size
,
1867 Reloc_symbol_changes
** reloc_map
);
1869 // Find all functions in a section.
1871 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
1874 // Write out the local symbols.
1876 write_local_symbols(Output_file
*,
1877 const Stringpool_template
<char>*,
1878 const Stringpool_template
<char>*,
1879 Output_symtab_xindex
*,
1880 Output_symtab_xindex
*);
1882 // Clear the local symbol information.
1884 clear_local_symbols()
1886 this->local_values_
.clear();
1887 this->local_got_offsets_
.clear();
1890 // Record a mapping from discarded section SHNDX to the corresponding
1893 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
1894 unsigned int kept_shndx
)
1896 Kept_comdat_section
kept(kept_object
, kept_shndx
);
1897 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
1900 // Find the kept section corresponding to the discarded section
1901 // SHNDX. Return true if found.
1903 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
1904 unsigned int* kept_shndx
) const
1906 typename
Kept_comdat_section_table::const_iterator p
=
1907 this->kept_comdat_sections_
.find(shndx
);
1908 if (p
== this->kept_comdat_sections_
.end())
1910 *kept_object
= p
->second
.object
;
1911 *kept_shndx
= p
->second
.shndx
;
1915 // The GOT offsets of local symbols. This map also stores GOT offsets
1916 // for tp-relative offsets for TLS symbols.
1917 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
1919 // The TLS GOT offsets of local symbols. The map stores the offsets
1920 // for either a single GOT entry that holds the module index of a TLS
1921 // symbol, or a pair of GOT entries containing the module index and
1922 // dtv-relative offset.
1923 struct Tls_got_entry
1925 Tls_got_entry(int got_offset
, bool have_pair
)
1926 : got_offset_(got_offset
),
1927 have_pair_(have_pair
)
1932 typedef Unordered_map
<unsigned int, Tls_got_entry
> Local_tls_got_offsets
;
1934 // Saved information for sections whose layout was deferred.
1935 struct Deferred_layout
1937 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
1938 Deferred_layout(unsigned int shndx
, const char* name
,
1939 const unsigned char* pshdr
,
1940 unsigned int reloc_shndx
, unsigned int reloc_type
)
1941 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
1942 reloc_type_(reloc_type
)
1944 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
1946 unsigned int shndx_
;
1948 unsigned int reloc_shndx_
;
1949 unsigned int reloc_type_
;
1950 unsigned char shdr_data_
[shdr_size
];
1953 // General access to the ELF file.
1954 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
1955 // Index of SHT_SYMTAB section.
1956 unsigned int symtab_shndx_
;
1957 // The number of local symbols.
1958 unsigned int local_symbol_count_
;
1959 // The number of local symbols which go into the output file.
1960 unsigned int output_local_symbol_count_
;
1961 // The number of local symbols which go into the output file's dynamic
1963 unsigned int output_local_dynsym_count_
;
1964 // The entries in the symbol table for the external symbols.
1966 // Number of symbols defined in object file itself.
1967 size_t defined_count_
;
1968 // File offset for local symbols.
1969 off_t local_symbol_offset_
;
1970 // File offset for local dynamic symbols.
1971 off_t local_dynsym_offset_
;
1972 // Values of local symbols.
1973 Local_values local_values_
;
1974 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1975 // for TLS symbols, indexed by symbol number.
1976 Local_got_offsets local_got_offsets_
;
1977 // For each input section, the offset of the input section in its
1978 // output section. This is INVALID_ADDRESS if the input section requires a
1980 std::vector
<Address
> section_offsets_
;
1981 // Table mapping discarded comdat sections to corresponding kept sections.
1982 Kept_comdat_section_table kept_comdat_sections_
;
1983 // Whether this object has a GNU style .eh_frame section.
1985 // If this object has a GNU style .eh_frame section that is discarded in
1986 // output, record the index here. Otherwise it is -1U.
1987 unsigned int discarded_eh_frame_shndx_
;
1988 // The list of sections whose layout was deferred.
1989 std::vector
<Deferred_layout
> deferred_layout_
;
1992 // A class to manage the list of all objects.
1998 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
2001 // The type of the list of input relocateable objects.
2002 typedef std::vector
<Relobj
*> Relobj_list
;
2003 typedef Relobj_list::const_iterator Relobj_iterator
;
2005 // The type of the list of input dynamic objects.
2006 typedef std::vector
<Dynobj
*> Dynobj_list
;
2007 typedef Dynobj_list::const_iterator Dynobj_iterator
;
2009 // Add an object to the list. Return true if all is well, or false
2010 // if this object should be ignored.
2012 add_object(Object
*);
2014 // Start processing an archive.
2016 archive_start(Archive
*);
2018 // Stop processing an archive.
2020 archive_stop(Archive
*);
2022 // For each dynamic object, check whether we've seen all of its
2023 // explicit dependencies.
2025 check_dynamic_dependencies() const;
2027 // Return whether an object was found in the system library
2030 found_in_system_library_directory(const Object
*) const;
2032 // Print symbol counts.
2034 print_symbol_counts(const Symbol_table
*) const;
2036 // Print a cross reference table.
2038 print_cref(const Symbol_table
*, FILE*) const;
2040 // Iterate over all regular objects.
2043 relobj_begin() const
2044 { return this->relobj_list_
.begin(); }
2048 { return this->relobj_list_
.end(); }
2050 // Iterate over all dynamic objects.
2053 dynobj_begin() const
2054 { return this->dynobj_list_
.begin(); }
2058 { return this->dynobj_list_
.end(); }
2060 // Return whether we have seen any dynamic objects.
2063 { return !this->dynobj_list_
.empty(); }
2065 // Return the number of non dynamic objects.
2067 number_of_relobjs() const
2068 { return this->relobj_list_
.size(); }
2070 // Return the number of input objects.
2072 number_of_input_objects() const
2073 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
2076 Input_objects(const Input_objects
&);
2077 Input_objects
& operator=(const Input_objects
&);
2079 // The list of ordinary objects included in the link.
2080 Relobj_list relobj_list_
;
2081 // The list of dynamic objects included in the link.
2082 Dynobj_list dynobj_list_
;
2083 // SONAMEs that we have seen.
2084 Unordered_set
<std::string
> sonames_
;
2085 // Manage cross-references if requested.
2089 // Some of the information we pass to the relocation routines. We
2090 // group this together to avoid passing a dozen different arguments.
2092 template<int size
, bool big_endian
>
2093 struct Relocate_info
2096 const Symbol_table
* symtab
;
2098 const Layout
* layout
;
2099 // Object being relocated.
2100 Sized_relobj
<size
, big_endian
>* object
;
2101 // Section index of relocation section.
2102 unsigned int reloc_shndx
;
2103 // Section header of relocation section.
2104 const unsigned char* reloc_shdr
;
2105 // Section index of section being relocated.
2106 unsigned int data_shndx
;
2107 // Section header of data section.
2108 const unsigned char* data_shdr
;
2110 // Return a string showing the location of a relocation. This is
2111 // only used for error messages.
2113 location(size_t relnum
, off_t reloffset
) const;
2116 // This is used to represent a section in an object and is used as the
2117 // key type for various section maps.
2118 typedef std::pair
<Object
*, unsigned int> Section_id
;
2120 // This is similar to Section_id but is used when the section
2121 // pointers are const.
2122 typedef std::pair
<const Object
*, unsigned int> Const_section_id
;
2124 // The hash value is based on the address of an object in memory during
2125 // linking. It is okay to use this for looking up sections but never use
2126 // this in an unordered container that we want to traverse in a repeatable
2129 struct Section_id_hash
2131 size_t operator()(const Section_id
& loc
) const
2132 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2135 struct Const_section_id_hash
2137 size_t operator()(const Const_section_id
& loc
) const
2138 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2141 // Return whether INPUT_FILE contains an ELF object start at file
2142 // offset OFFSET. This sets *START to point to a view of the start of
2143 // the file. It sets *READ_SIZE to the number of bytes in the view.
2146 is_elf_object(Input_file
* input_file
, off_t offset
,
2147 const unsigned char** start
, int *read_size
);
2149 // Return an Object appropriate for the input file. P is BYTES long,
2150 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2151 // this sees an object the linker is not configured to support, it
2152 // sets *PUNCONFIGURED to true and returns NULL without giving an
2156 make_elf_object(const std::string
& name
, Input_file
*,
2157 off_t offset
, const unsigned char* p
,
2158 section_offset_type bytes
, bool* punconfigured
);
2160 } // end namespace gold
2162 #endif // !defined(GOLD_OBJECT_H)