1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
7 // This file is part of gold.
9 // This program is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3 of the License, or
12 // (at your option) any later version.
14 // This program is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 // MA 02110-1301, USA.
31 #include "elfcpp_file.h"
39 class General_options
;
46 class Output_symtab_xindex
;
49 class Object_merge_map
;
50 class Relocatable_relocs
;
53 template<typename Stringpool_char
>
54 class Stringpool_template
;
56 // Data to pass from read_symbols() to add_symbols().
58 struct Read_symbols_data
61 : section_headers(NULL
), section_names(NULL
), symbols(NULL
),
62 symbol_names(NULL
), versym(NULL
), verdef(NULL
), verneed(NULL
)
68 File_view
* section_headers
;
70 File_view
* section_names
;
71 // Size of section name data in bytes.
72 section_size_type section_names_size
;
75 // Size of symbol data in bytes.
76 section_size_type symbols_size
;
77 // Offset of external symbols within symbol data. This structure
78 // sometimes contains only external symbols, in which case this will
79 // be zero. Sometimes it contains all symbols.
80 section_offset_type external_symbols_offset
;
82 File_view
* symbol_names
;
83 // Size of symbol name data in bytes.
84 section_size_type symbol_names_size
;
86 // Version information. This is only used on dynamic objects.
87 // Version symbol data (from SHT_GNU_versym section).
89 section_size_type versym_size
;
90 // Version definition data (from SHT_GNU_verdef section).
92 section_size_type verdef_size
;
93 unsigned int verdef_info
;
94 // Needed version data (from SHT_GNU_verneed section).
96 section_size_type verneed_size
;
97 unsigned int verneed_info
;
100 // Information used to print error messages.
102 struct Symbol_location_info
104 std::string source_file
;
105 std::string enclosing_symbol_name
;
109 // Data about a single relocation section. This is read in
110 // read_relocs and processed in scan_relocs.
112 struct Section_relocs
119 { delete this->contents
; }
121 // Index of reloc section.
122 unsigned int reloc_shndx
;
123 // Index of section that relocs apply to.
124 unsigned int data_shndx
;
125 // Contents of reloc section.
127 // Reloc section type.
128 unsigned int sh_type
;
129 // Number of reloc entries.
132 Output_section
* output_section
;
133 // Whether this section has special handling for offsets.
134 bool needs_special_offset_handling
;
135 // Whether the data section is allocated (has the SHF_ALLOC flag set).
136 bool is_data_section_allocated
;
139 // Relocations in an object file. This is read in read_relocs and
140 // processed in scan_relocs.
142 struct Read_relocs_data
145 : local_symbols(NULL
)
149 { delete this->local_symbols
; }
151 typedef std::vector
<Section_relocs
> Relocs_list
;
154 // The local symbols.
155 File_view
* local_symbols
;
158 // The Xindex class manages section indexes for objects with more than
164 Xindex(int large_shndx_offset
)
165 : large_shndx_offset_(large_shndx_offset
), symtab_xindex_()
168 // Initialize the symtab_xindex_ array, given the object and the
169 // section index of the symbol table to use.
170 template<int size
, bool big_endian
>
172 initialize_symtab_xindex(Object
*, unsigned int symtab_shndx
);
174 // Read in the symtab_xindex_ array, given its section index.
175 // PSHDRS may optionally point to the section headers.
176 template<int size
, bool big_endian
>
178 read_symtab_xindex(Object
*, unsigned int xindex_shndx
,
179 const unsigned char* pshdrs
);
181 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
182 // real section index.
184 sym_xindex_to_shndx(Object
* object
, unsigned int symndx
);
187 // The type of the array giving the real section index for symbols
188 // whose st_shndx field holds SHN_XINDEX.
189 typedef std::vector
<unsigned int> Symtab_xindex
;
191 // Adjust a section index if necessary. This should only be called
192 // for ordinary section indexes.
194 adjust_shndx(unsigned int shndx
)
196 if (shndx
>= elfcpp::SHN_LORESERVE
)
197 shndx
+= this->large_shndx_offset_
;
201 // Adjust to apply to large section indexes.
202 int large_shndx_offset_
;
203 // The data from the SHT_SYMTAB_SHNDX section.
204 Symtab_xindex symtab_xindex_
;
207 // A GOT offset list. A symbol may have more than one GOT offset
208 // (e.g., when mixing modules compiled with two different TLS models),
209 // but will usually have at most one. GOT_TYPE identifies the type of
210 // GOT entry; its values are specific to each target.
212 class Got_offset_list
216 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
219 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
220 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
225 if (this->got_next_
!= NULL
)
227 delete this->got_next_
;
228 this->got_next_
= NULL
;
232 // Initialize the fields to their default values.
236 this->got_type_
= -1U;
237 this->got_offset_
= 0;
238 this->got_next_
= NULL
;
241 // Set the offset for the GOT entry of type GOT_TYPE.
243 set_offset(unsigned int got_type
, unsigned int got_offset
)
245 if (this->got_type_
== -1U)
247 this->got_type_
= got_type
;
248 this->got_offset_
= got_offset
;
252 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
254 if (g
->got_type_
== got_type
)
256 g
->got_offset_
= got_offset
;
260 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
261 g
->got_next_
= this->got_next_
;
266 // Return the offset for a GOT entry of type GOT_TYPE.
268 get_offset(unsigned int got_type
) const
270 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
272 if (g
->got_type_
== got_type
)
273 return g
->got_offset_
;
278 // Return a pointer to the list, or NULL if the list is empty.
279 const Got_offset_list
*
282 if (this->got_type_
== -1U)
287 // Abstract visitor class for iterating over GOT offsets.
299 visit(unsigned int, unsigned int) = 0;
302 // Loop over all GOT offset entries, calling a visitor class V for each.
304 for_all_got_offsets(Visitor
* v
) const
306 if (this->got_type_
== -1U)
308 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
309 v
->visit(g
->got_type_
, g
->got_offset_
);
313 unsigned int got_type_
;
314 unsigned int got_offset_
;
315 Got_offset_list
* got_next_
;
318 // Object is an abstract base class which represents either a 32-bit
319 // or a 64-bit input object. This can be a regular object file
320 // (ET_REL) or a shared object (ET_DYN).
325 typedef std::vector
<Symbol
*> Symbols
;
327 // NAME is the name of the object as we would report it to the user
328 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
329 // used to read the file. OFFSET is the offset within the input
330 // file--0 for a .o or .so file, something else for a .a file.
331 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
333 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
334 is_dynamic_(is_dynamic
), is_needed_(false), uses_split_stack_(false),
335 has_no_split_stack_(false), no_export_(false),
336 is_in_system_directory_(false), as_needed_(false), xindex_(NULL
)
338 if (input_file
!= NULL
)
340 input_file
->file().add_object();
341 this->is_in_system_directory_
= input_file
->is_in_system_directory();
342 this->as_needed_
= input_file
->options().as_needed();
348 if (this->input_file_
!= NULL
)
349 this->input_file_
->file().remove_object();
352 // Return the name of the object as we would report it to the user.
355 { return this->name_
; }
357 // Get the offset into the file.
360 { return this->offset_
; }
362 // Return whether this is a dynamic object.
365 { return this->is_dynamic_
; }
367 // Return whether this object is needed--true if it is a dynamic
368 // object which defines some symbol referenced by a regular object.
369 // We keep the flag here rather than in Dynobj for convenience when
373 { return this->is_needed_
; }
375 // Record that this object is needed.
378 { this->is_needed_
= true; }
380 // Return whether this object was compiled with -fsplit-stack.
382 uses_split_stack() const
383 { return this->uses_split_stack_
; }
385 // Return whether this object contains any functions compiled with
386 // the no_split_stack attribute.
388 has_no_split_stack() const
389 { return this->has_no_split_stack_
; }
391 // Returns NULL for Objects that are not dynamic objects. This method
392 // is overridden in the Dynobj class.
395 { return this->do_dynobj(); }
397 // Returns NULL for Objects that are not plugin objects. This method
398 // is overridden in the Pluginobj class.
401 { return this->do_pluginobj(); }
403 // Get the file. We pass on const-ness.
407 gold_assert(this->input_file_
!= NULL
);
408 return this->input_file_
;
414 gold_assert(this->input_file_
!= NULL
);
415 return this->input_file_
;
418 // Lock the underlying file.
422 if (this->input_file_
!= NULL
)
423 this->input_file_
->file().lock(t
);
426 // Unlock the underlying file.
428 unlock(const Task
* t
)
430 if (this->input_file_
!= NULL
)
431 this->input_file()->file().unlock(t
);
434 // Return whether the underlying file is locked.
437 { return this->input_file_
!= NULL
&& this->input_file_
->file().is_locked(); }
439 // Return the token, so that the task can be queued.
443 if (this->input_file_
== NULL
)
445 return this->input_file()->file().token();
448 // Release the underlying file.
452 if (this->input_file_
!= NULL
)
453 this->input_file()->file().release();
456 // Return whether we should just read symbols from this file.
459 { return this->input_file()->just_symbols(); }
461 // Return whether this is an incremental object.
463 is_incremental() const
464 { return this->do_is_incremental(); }
466 // Return the last modified time of the file.
469 { return this->do_get_mtime(); }
471 // Get the number of sections.
474 { return this->shnum_
; }
476 // Return a view of the contents of a section. Set *PLEN to the
477 // size. CACHE is a hint as in File_read::get_view.
479 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
481 // Adjust a symbol's section index as needed. SYMNDX is the index
482 // of the symbol and SHNDX is the symbol's section from
483 // get_st_shndx. This returns the section index. It sets
484 // *IS_ORDINARY to indicate whether this is a normal section index,
485 // rather than a special code between SHN_LORESERVE and
488 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
490 if (shndx
< elfcpp::SHN_LORESERVE
)
492 else if (shndx
== elfcpp::SHN_XINDEX
)
494 if (this->xindex_
== NULL
)
495 this->xindex_
= this->do_initialize_xindex();
496 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
500 *is_ordinary
= false;
504 // Return the size of a section given a section index.
506 section_size(unsigned int shndx
)
507 { return this->do_section_size(shndx
); }
509 // Return the name of a section given a section index.
511 section_name(unsigned int shndx
)
512 { return this->do_section_name(shndx
); }
514 // Return the section flags given a section index.
516 section_flags(unsigned int shndx
)
517 { return this->do_section_flags(shndx
); }
519 // Return the section entsize given a section index.
521 section_entsize(unsigned int shndx
)
522 { return this->do_section_entsize(shndx
); }
524 // Return the section address given a section index.
526 section_address(unsigned int shndx
)
527 { return this->do_section_address(shndx
); }
529 // Return the section type given a section index.
531 section_type(unsigned int shndx
)
532 { return this->do_section_type(shndx
); }
534 // Return the section link field given a section index.
536 section_link(unsigned int shndx
)
537 { return this->do_section_link(shndx
); }
539 // Return the section info field given a section index.
541 section_info(unsigned int shndx
)
542 { return this->do_section_info(shndx
); }
544 // Return the required section alignment given a section index.
546 section_addralign(unsigned int shndx
)
547 { return this->do_section_addralign(shndx
); }
549 // Return the output section given a section index.
551 output_section(unsigned int shndx
) const
552 { return this->do_output_section(shndx
); }
554 // Given a section index, return the offset in the Output_section.
555 // The return value will be -1U if the section is specially mapped,
556 // such as a merge section.
558 output_section_offset(unsigned int shndx
) const
559 { return this->do_output_section_offset(shndx
); }
561 // Read the symbol information.
563 read_symbols(Read_symbols_data
* sd
)
564 { return this->do_read_symbols(sd
); }
566 // Pass sections which should be included in the link to the Layout
567 // object, and record where the sections go in the output file.
569 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
570 { this->do_layout(symtab
, layout
, sd
); }
572 // Add symbol information to the global symbol table.
574 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
575 { this->do_add_symbols(symtab
, sd
, layout
); }
577 // Add symbol information to the global symbol table.
578 Archive::Should_include
579 should_include_member(Symbol_table
* symtab
, Layout
* layout
,
580 Read_symbols_data
* sd
, std::string
* why
)
581 { return this->do_should_include_member(symtab
, layout
, sd
, why
); }
583 // Iterate over global symbols, calling a visitor class V for each.
585 for_all_global_symbols(Read_symbols_data
* sd
,
586 Library_base::Symbol_visitor_base
* v
)
587 { return this->do_for_all_global_symbols(sd
, v
); }
589 // Iterate over local symbols, calling a visitor class V for each GOT offset
590 // associated with a local symbol.
592 for_all_local_got_entries(Got_offset_list::Visitor
* v
) const
593 { this->do_for_all_local_got_entries(v
); }
595 // Functions and types for the elfcpp::Elf_file interface. This
596 // permit us to use Object as the File template parameter for
599 // The View class is returned by view. It must support a single
600 // method, data(). This is trivial, because get_view does what we
605 View(const unsigned char* p
)
614 const unsigned char* p_
;
619 view(off_t file_offset
, section_size_type data_size
)
620 { return View(this->get_view(file_offset
, data_size
, true, true)); }
624 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
626 // A location in the file.
632 Location(off_t fo
, section_size_type ds
)
633 : file_offset(fo
), data_size(ds
)
637 // Get a View given a Location.
638 View
view(Location loc
)
639 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
641 // Get a view into the underlying file.
643 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
645 return this->input_file()->file().get_view(this->offset_
, start
, size
,
649 // Get a lasting view into the underlying file.
651 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
654 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
655 size
, aligned
, cache
);
658 // Read data from the underlying file.
660 read(off_t start
, section_size_type size
, void* p
)
661 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
663 // Read multiple data from the underlying file.
665 read_multiple(const File_read::Read_multiple
& rm
)
666 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
668 // Stop caching views in the underlying file.
670 clear_view_cache_marks()
672 if (this->input_file_
!= NULL
)
673 this->input_file_
->file().clear_view_cache_marks();
676 // Get the number of global symbols defined by this object, and the
677 // number of the symbols whose final definition came from this
680 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
682 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
684 // Get the symbols defined in this object.
686 get_global_symbols() const
687 { return this->do_get_global_symbols(); }
689 // Set flag that this object was found in a system directory.
691 set_is_in_system_directory()
692 { this->is_in_system_directory_
= true; }
694 // Return whether this object was found in a system directory.
696 is_in_system_directory() const
697 { return this->is_in_system_directory_
; }
699 // Set flag that this object was linked with --as-needed.
702 { this->as_needed_
= true; }
704 // Return whether this object was linked with --as-needed.
707 { return this->as_needed_
; }
709 // Return whether we found this object by searching a directory.
712 { return this->input_file()->will_search_for(); }
716 { return this->no_export_
; }
719 set_no_export(bool value
)
720 { this->no_export_
= value
; }
722 // Return TRUE if the section is a compressed debug section, and set
723 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
725 section_is_compressed(unsigned int shndx
,
726 section_size_type
* uncompressed_size
) const
727 { return this->do_section_is_compressed(shndx
, uncompressed_size
); }
729 // Return a view of the decompressed contents of a section. Set *PLEN
730 // to the size. Set *IS_NEW to true if the contents need to be freed
733 decompressed_section_contents(unsigned int shndx
, section_size_type
* plen
,
735 { return this->do_decompressed_section_contents(shndx
, plen
, is_cached
); }
737 // Discard any buffers of decompressed sections. This is done
738 // at the end of the Add_symbols task.
740 discard_decompressed_sections()
741 { this->do_discard_decompressed_sections(); }
743 // Return the index of the first incremental relocation for symbol SYMNDX.
745 get_incremental_reloc_base(unsigned int symndx
) const
746 { return this->do_get_incremental_reloc_base(symndx
); }
748 // Return the number of incremental relocations for symbol SYMNDX.
750 get_incremental_reloc_count(unsigned int symndx
) const
751 { return this->do_get_incremental_reloc_count(symndx
); }
754 // Returns NULL for Objects that are not dynamic objects. This method
755 // is overridden in the Dynobj class.
760 // Returns NULL for Objects that are not plugin objects. This method
761 // is overridden in the Pluginobj class.
766 // Return TRUE if this is an incremental (unchanged) input file.
767 // We return FALSE by default; the incremental object classes
768 // override this method.
770 do_is_incremental() const
773 // Return the last modified time of the file. This method may be
774 // overridden for subclasses that don't use an actual file (e.g.,
775 // Incremental objects).
778 { return this->input_file()->file().get_mtime(); }
780 // Read the symbols--implemented by child class.
782 do_read_symbols(Read_symbols_data
*) = 0;
784 // Lay out sections--implemented by child class.
786 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
788 // Add symbol information to the global symbol table--implemented by
791 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
793 virtual Archive::Should_include
794 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
795 std::string
* why
) = 0;
797 // Iterate over global symbols, calling a visitor class V for each.
799 do_for_all_global_symbols(Read_symbols_data
* sd
,
800 Library_base::Symbol_visitor_base
* v
) = 0;
802 // Iterate over local symbols, calling a visitor class V for each GOT offset
803 // associated with a local symbol.
805 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const = 0;
807 // Return the location of the contents of a section. Implemented by
809 virtual const unsigned char*
810 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
813 // Get the size of a section--implemented by child class.
815 do_section_size(unsigned int shndx
) = 0;
817 // Get the name of a section--implemented by child class.
819 do_section_name(unsigned int shndx
) = 0;
821 // Get section flags--implemented by child class.
823 do_section_flags(unsigned int shndx
) = 0;
825 // Get section entsize--implemented by child class.
827 do_section_entsize(unsigned int shndx
) = 0;
829 // Get section address--implemented by child class.
831 do_section_address(unsigned int shndx
) = 0;
833 // Get section type--implemented by child class.
835 do_section_type(unsigned int shndx
) = 0;
837 // Get section link field--implemented by child class.
839 do_section_link(unsigned int shndx
) = 0;
841 // Get section info field--implemented by child class.
843 do_section_info(unsigned int shndx
) = 0;
845 // Get section alignment--implemented by child class.
847 do_section_addralign(unsigned int shndx
) = 0;
849 // Return the output section given a section index--implemented
851 virtual Output_section
*
852 do_output_section(unsigned int) const
853 { gold_unreachable(); }
855 // Get the offset of a section--implemented by child class.
857 do_output_section_offset(unsigned int) const
858 { gold_unreachable(); }
860 // Return the Xindex structure to use.
862 do_initialize_xindex() = 0;
864 // Implement get_global_symbol_counts--implemented by child class.
866 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
868 virtual const Symbols
*
869 do_get_global_symbols() const = 0;
871 // Set the number of sections.
874 { this->shnum_
= shnum
; }
876 // Functions used by both Sized_relobj_file and Sized_dynobj.
878 // Read the section data into a Read_symbols_data object.
879 template<int size
, bool big_endian
>
881 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
884 // Let the child class initialize the xindex object directly.
886 set_xindex(Xindex
* xindex
)
888 gold_assert(this->xindex_
== NULL
);
889 this->xindex_
= xindex
;
892 // If NAME is the name of a special .gnu.warning section, arrange
893 // for the warning to be issued. SHNDX is the section index.
894 // Return whether it is a warning section.
896 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
899 // If NAME is the name of the special section which indicates that
900 // this object was compiled with -fsplit-stack, mark it accordingly,
901 // and return true. Otherwise return false.
903 handle_split_stack_section(const char* name
);
905 // Return TRUE if the section is a compressed debug section, and set
906 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
908 do_section_is_compressed(unsigned int, section_size_type
*) const
911 // Return a view of the decompressed contents of a section. Set *PLEN
912 // to the size. This default implementation simply returns the
913 // raw section contents and sets *IS_NEW to false to indicate
914 // that the contents do not need to be freed by the caller.
915 // This function must be overridden for any types of object files
916 // that might contain compressed sections.
917 virtual const unsigned char*
918 do_decompressed_section_contents(unsigned int shndx
,
919 section_size_type
* plen
,
923 return this->do_section_contents(shndx
, plen
, false);
926 // Discard any buffers of decompressed sections. This is done
927 // at the end of the Add_symbols task.
929 do_discard_decompressed_sections()
932 // Return the index of the first incremental relocation for symbol SYMNDX--
933 // implemented by child class.
935 do_get_incremental_reloc_base(unsigned int) const
936 { gold_unreachable(); }
938 // Return the number of incremental relocations for symbol SYMNDX--
939 // implemented by child class.
941 do_get_incremental_reloc_count(unsigned int) const
942 { gold_unreachable(); }
945 // This class may not be copied.
946 Object(const Object
&);
947 Object
& operator=(const Object
&);
949 // Name of object as printed to user.
951 // For reading the file.
952 Input_file
* input_file_
;
953 // Offset within the file--0 for an object file, non-0 for an
956 // Number of input sections.
958 // Whether this is a dynamic object.
959 bool is_dynamic_
: 1;
960 // Whether this object is needed. This is only set for dynamic
961 // objects, and means that the object defined a symbol which was
962 // used by a reference from a regular object.
964 // Whether this object was compiled with -fsplit-stack.
965 bool uses_split_stack_
: 1;
966 // Whether this object contains any functions compiled with the
967 // no_split_stack attribute.
968 bool has_no_split_stack_
: 1;
969 // True if exclude this object from automatic symbol export.
970 // This is used only for archive objects.
972 // True if the object was found in a system directory.
973 bool is_in_system_directory_
: 1;
974 // True if the object was linked with --as-needed.
976 // Many sections for objects with more than SHN_LORESERVE sections.
980 // A regular object (ET_REL). This is an abstract base class itself.
981 // The implementation is the template class Sized_relobj_file.
983 class Relobj
: public Object
986 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
987 : Object(name
, input_file
, false, offset
),
989 map_to_relocatable_relocs_(NULL
),
990 object_merge_map_(NULL
),
991 relocs_must_follow_section_writes_(false),
999 // During garbage collection, the Read_symbols_data pass for
1000 // each object is stored as layout needs to be done after
1001 // reloc processing.
1004 { return this->sd_
; }
1006 // Decides which section names have to be included in the worklist
1009 is_section_name_included(const char* name
);
1012 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
1013 unsigned int section_header_size
);
1016 set_symbols_data(Symbols_data
* sd
)
1019 // During garbage collection, the Read_relocs pass for all objects
1020 // is done before scanning the relocs. In that case, this->rd_ is
1021 // used to store the information from Read_relocs for each object.
1022 // This data is also used to compute the list of relevant sections.
1025 { return this->rd_
; }
1028 set_relocs_data(Read_relocs_data
* rd
)
1032 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
1036 read_relocs(Read_relocs_data
* rd
)
1037 { return this->do_read_relocs(rd
); }
1039 // Process the relocs, during garbage collection only.
1041 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1042 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
1044 // Scan the relocs and adjust the symbol table.
1046 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1047 { return this->do_scan_relocs(symtab
, layout
, rd
); }
1049 // Return the value of the local symbol whose index is SYMNDX, plus
1050 // ADDEND. ADDEND is passed in so that we can correctly handle the
1051 // section symbol for a merge section.
1053 local_symbol_value(unsigned int symndx
, uint64_t addend
) const
1054 { return this->do_local_symbol_value(symndx
, addend
); }
1056 // Return the PLT offset for a local symbol. It is an error to call
1057 // this if it doesn't have one.
1059 local_plt_offset(unsigned int symndx
) const
1060 { return this->do_local_plt_offset(symndx
); }
1062 // Return whether the local symbol SYMNDX has a GOT offset of type
1065 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1066 { return this->do_local_has_got_offset(symndx
, got_type
); }
1068 // Return the GOT offset of type GOT_TYPE of the local symbol
1069 // SYMNDX. It is an error to call this if the symbol does not have
1070 // a GOT offset of the specified type.
1072 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1073 { return this->do_local_got_offset(symndx
, got_type
); }
1075 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1078 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1079 unsigned int got_offset
)
1080 { this->do_set_local_got_offset(symndx
, got_type
, got_offset
); }
1082 // Return whether the local symbol SYMNDX is a TLS symbol.
1084 local_is_tls(unsigned int symndx
) const
1085 { return this->do_local_is_tls(symndx
); }
1087 // The number of local symbols in the input symbol table.
1088 virtual unsigned int
1089 local_symbol_count() const
1090 { return this->do_local_symbol_count(); }
1092 // The number of local symbols in the output symbol table.
1093 virtual unsigned int
1094 output_local_symbol_count() const
1095 { return this->do_output_local_symbol_count(); }
1097 // The file offset for local symbols in the output symbol table.
1099 local_symbol_offset() const
1100 { return this->do_local_symbol_offset(); }
1102 // Initial local symbol processing: count the number of local symbols
1103 // in the output symbol table and dynamic symbol table; add local symbol
1104 // names to *POOL and *DYNPOOL.
1106 count_local_symbols(Stringpool_template
<char>* pool
,
1107 Stringpool_template
<char>* dynpool
)
1108 { return this->do_count_local_symbols(pool
, dynpool
); }
1110 // Set the values of the local symbols, set the output symbol table
1111 // indexes for the local variables, and set the offset where local
1112 // symbol information will be stored. Returns the new local symbol index.
1114 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
1115 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
1117 // Set the output dynamic symbol table indexes for the local variables.
1119 set_local_dynsym_indexes(unsigned int index
)
1120 { return this->do_set_local_dynsym_indexes(index
); }
1122 // Set the offset where local dynamic symbol information will be stored.
1124 set_local_dynsym_offset(off_t off
)
1125 { return this->do_set_local_dynsym_offset(off
); }
1127 // Record a dynamic relocation against an input section from this object.
1129 add_dyn_reloc(unsigned int index
)
1131 if (this->dyn_reloc_count_
== 0)
1132 this->first_dyn_reloc_
= index
;
1133 ++this->dyn_reloc_count_
;
1136 // Return the index of the first dynamic relocation.
1138 first_dyn_reloc() const
1139 { return this->first_dyn_reloc_
; }
1141 // Return the count of dynamic relocations.
1143 dyn_reloc_count() const
1144 { return this->dyn_reloc_count_
; }
1146 // Relocate the input sections and write out the local symbols.
1148 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
1149 { return this->do_relocate(symtab
, layout
, of
); }
1151 // Return whether an input section is being included in the link.
1153 is_section_included(unsigned int shndx
) const
1155 gold_assert(shndx
< this->output_sections_
.size());
1156 return this->output_sections_
[shndx
] != NULL
;
1159 // The the output section of the input section with index SHNDX.
1160 // This is only used currently to remove a section from the link in
1163 set_output_section(unsigned int shndx
, Output_section
* os
)
1165 gold_assert(shndx
< this->output_sections_
.size());
1166 this->output_sections_
[shndx
] = os
;
1169 // Set the offset of an input section within its output section.
1171 set_section_offset(unsigned int shndx
, uint64_t off
)
1172 { this->do_set_section_offset(shndx
, off
); }
1174 // Return true if we need to wait for output sections to be written
1175 // before we can apply relocations. This is true if the object has
1176 // any relocations for sections which require special handling, such
1177 // as the exception frame section.
1179 relocs_must_follow_section_writes() const
1180 { return this->relocs_must_follow_section_writes_
; }
1182 // Return the object merge map.
1185 { return this->object_merge_map_
; }
1187 // Set the object merge map.
1189 set_merge_map(Object_merge_map
* object_merge_map
)
1191 gold_assert(this->object_merge_map_
== NULL
);
1192 this->object_merge_map_
= object_merge_map
;
1195 // Record the relocatable reloc info for an input reloc section.
1197 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
1199 gold_assert(reloc_shndx
< this->shnum());
1200 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
1203 // Get the relocatable reloc info for an input reloc section.
1205 relocatable_relocs(unsigned int reloc_shndx
)
1207 gold_assert(reloc_shndx
< this->shnum());
1208 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
1211 // Layout sections whose layout was deferred while waiting for
1212 // input files from a plugin.
1214 layout_deferred_sections(Layout
* layout
)
1215 { this->do_layout_deferred_sections(layout
); }
1217 // Return the index of the first incremental relocation for symbol SYMNDX.
1218 virtual unsigned int
1219 do_get_incremental_reloc_base(unsigned int symndx
) const
1220 { return this->reloc_bases_
[symndx
]; }
1222 // Return the number of incremental relocations for symbol SYMNDX.
1223 virtual unsigned int
1224 do_get_incremental_reloc_count(unsigned int symndx
) const
1225 { return this->reloc_counts_
[symndx
]; }
1227 // Return the word size of the object file.
1230 { return this->do_elfsize(); }
1232 // Return TRUE if this is a big-endian object file.
1234 is_big_endian() const
1235 { return this->do_is_big_endian(); }
1238 // The output section to be used for each input section, indexed by
1239 // the input section number. The output section is NULL if the
1240 // input section is to be discarded.
1241 typedef std::vector
<Output_section
*> Output_sections
;
1243 // Read the relocs--implemented by child class.
1245 do_read_relocs(Read_relocs_data
*) = 0;
1247 // Process the relocs--implemented by child class.
1249 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1251 // Scan the relocs--implemented by child class.
1253 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1255 // Return the value of a local symbol.
1257 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const = 0;
1259 // Return the PLT offset of a local symbol.
1260 virtual unsigned int
1261 do_local_plt_offset(unsigned int symndx
) const = 0;
1263 // Return whether a local symbol has a GOT offset of a given type.
1265 do_local_has_got_offset(unsigned int symndx
,
1266 unsigned int got_type
) const = 0;
1268 // Return the GOT offset of a given type of a local symbol.
1269 virtual unsigned int
1270 do_local_got_offset(unsigned int symndx
, unsigned int got_type
) const = 0;
1272 // Set the GOT offset with a given type for a local symbol.
1274 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1275 unsigned int got_offset
) = 0;
1277 // Return whether local symbol SYMNDX is a TLS symbol.
1279 do_local_is_tls(unsigned int symndx
) const = 0;
1281 // Return the number of local symbols--implemented by child class.
1282 virtual unsigned int
1283 do_local_symbol_count() const = 0;
1285 // Return the number of output local symbols--implemented by child class.
1286 virtual unsigned int
1287 do_output_local_symbol_count() const = 0;
1289 // Return the file offset for local symbols--implemented by child class.
1291 do_local_symbol_offset() const = 0;
1293 // Count local symbols--implemented by child class.
1295 do_count_local_symbols(Stringpool_template
<char>*,
1296 Stringpool_template
<char>*) = 0;
1298 // Finalize the local symbols. Set the output symbol table indexes
1299 // for the local variables, and set the offset where local symbol
1300 // information will be stored.
1301 virtual unsigned int
1302 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
1304 // Set the output dynamic symbol table indexes for the local variables.
1305 virtual unsigned int
1306 do_set_local_dynsym_indexes(unsigned int) = 0;
1308 // Set the offset where local dynamic symbol information will be stored.
1309 virtual unsigned int
1310 do_set_local_dynsym_offset(off_t
) = 0;
1312 // Relocate the input sections and write out the local
1313 // symbols--implemented by child class.
1315 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
1317 // Set the offset of a section--implemented by child class.
1319 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
1321 // Layout sections whose layout was deferred while waiting for
1322 // input files from a plugin--implemented by child class.
1324 do_layout_deferred_sections(Layout
*) = 0;
1326 // Given a section index, return the corresponding Output_section.
1327 // The return value will be NULL if the section is not included in
1330 do_output_section(unsigned int shndx
) const
1332 gold_assert(shndx
< this->output_sections_
.size());
1333 return this->output_sections_
[shndx
];
1336 // Return the vector mapping input sections to output sections.
1339 { return this->output_sections_
; }
1341 const Output_sections
&
1342 output_sections() const
1343 { return this->output_sections_
; }
1345 // Set the size of the relocatable relocs array.
1347 size_relocatable_relocs()
1349 this->map_to_relocatable_relocs_
=
1350 new std::vector
<Relocatable_relocs
*>(this->shnum());
1353 // Record that we must wait for the output sections to be written
1354 // before applying relocations.
1356 set_relocs_must_follow_section_writes()
1357 { this->relocs_must_follow_section_writes_
= true; }
1359 // Allocate the array for counting incremental relocations.
1361 allocate_incremental_reloc_counts()
1363 unsigned int nsyms
= this->do_get_global_symbols()->size();
1364 this->reloc_counts_
= new unsigned int[nsyms
];
1365 gold_assert(this->reloc_counts_
!= NULL
);
1366 memset(this->reloc_counts_
, 0, nsyms
* sizeof(unsigned int));
1369 // Record a relocation in this object referencing global symbol SYMNDX.
1370 // Used for tracking incremental link information.
1372 count_incremental_reloc(unsigned int symndx
)
1374 unsigned int nsyms
= this->do_get_global_symbols()->size();
1375 gold_assert(symndx
< nsyms
);
1376 gold_assert(this->reloc_counts_
!= NULL
);
1377 ++this->reloc_counts_
[symndx
];
1380 // Finalize the incremental relocation information.
1382 finalize_incremental_relocs(Layout
* layout
, bool clear_counts
);
1384 // Return the index of the next relocation to be written for global symbol
1385 // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
1387 next_incremental_reloc_index(unsigned int symndx
)
1389 unsigned int nsyms
= this->do_get_global_symbols()->size();
1391 gold_assert(this->reloc_counts_
!= NULL
);
1392 gold_assert(this->reloc_bases_
!= NULL
);
1393 gold_assert(symndx
< nsyms
);
1395 unsigned int counter
= this->reloc_counts_
[symndx
]++;
1396 return this->reloc_bases_
[symndx
] + counter
;
1399 // Return the word size of the object file--
1400 // implemented by child class.
1402 do_elfsize() const = 0;
1404 // Return TRUE if this is a big-endian object file--
1405 // implemented by child class.
1407 do_is_big_endian() const = 0;
1410 // Mapping from input sections to output section.
1411 Output_sections output_sections_
;
1412 // Mapping from input section index to the information recorded for
1413 // the relocations. This is only used for a relocatable link.
1414 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
1415 // Mappings for merge sections. This is managed by the code in the
1417 Object_merge_map
* object_merge_map_
;
1418 // Whether we need to wait for output sections to be written before
1419 // we can apply relocations.
1420 bool relocs_must_follow_section_writes_
;
1421 // Used to store the relocs data computed by the Read_relocs pass.
1422 // Used during garbage collection of unused sections.
1423 Read_relocs_data
* rd_
;
1424 // Used to store the symbols data computed by the Read_symbols pass.
1425 // Again used during garbage collection when laying out referenced
1427 gold::Symbols_data
* sd_
;
1428 // Per-symbol counts of relocations, for incremental links.
1429 unsigned int* reloc_counts_
;
1430 // Per-symbol base indexes of relocations, for incremental links.
1431 unsigned int* reloc_bases_
;
1432 // Index of the first dynamic relocation for this object.
1433 unsigned int first_dyn_reloc_
;
1434 // Count of dynamic relocations for this object.
1435 unsigned int dyn_reloc_count_
;
1438 // This class is used to handle relocations against a section symbol
1439 // in an SHF_MERGE section. For such a symbol, we need to know the
1440 // addend of the relocation before we can determine the final value.
1441 // The addend gives us the location in the input section, and we can
1442 // determine how it is mapped to the output section. For a
1443 // non-section symbol, we apply the addend to the final value of the
1444 // symbol; that is done in finalize_local_symbols, and does not use
1448 class Merged_symbol_value
1451 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1453 // We use a hash table to map offsets in the input section to output
1455 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
1457 Merged_symbol_value(Value input_value
, Value output_start_address
)
1458 : input_value_(input_value
), output_start_address_(output_start_address
),
1462 // Initialize the hash table.
1464 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
1466 // Release the hash table to save space.
1468 free_input_to_output_map()
1469 { this->output_addresses_
.clear(); }
1471 // Get the output value corresponding to an addend. The object and
1472 // input section index are passed in because the caller will have
1473 // them; otherwise we could store them here.
1475 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
1477 // This is a relocation against a section symbol. ADDEND is the
1478 // offset in the section. The result should be the start of some
1479 // merge area. If the object file wants something else, it should
1480 // use a regular symbol rather than a section symbol.
1481 // Unfortunately, PR 6658 shows a case in which the object file
1482 // refers to the section symbol, but uses a negative ADDEND to
1483 // compensate for a PC relative reloc. We can't handle the
1484 // general case. However, we can handle the special case of a
1485 // negative addend, by assuming that it refers to the start of the
1486 // section. Of course, that means that we have to guess when
1487 // ADDEND is negative. It is normal to see a 32-bit value here
1488 // even when the template parameter size is 64, as 64-bit object
1489 // file formats have 32-bit relocations. We know this is a merge
1490 // section, so we know it has to fit into memory. So we assume
1491 // that we won't see a value larger than a large 32-bit unsigned
1492 // value. This will break objects with very very large merge
1493 // sections; they probably break in other ways anyhow.
1494 Value input_offset
= this->input_value_
;
1495 if (addend
< 0xffffff00)
1497 input_offset
+= addend
;
1500 typename
Output_addresses::const_iterator p
=
1501 this->output_addresses_
.find(input_offset
);
1502 if (p
!= this->output_addresses_
.end())
1503 return p
->second
+ addend
;
1505 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
1510 // Get the output value for an input offset if we couldn't find it
1511 // in the hash table.
1513 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
1514 Value input_offset
) const;
1516 // The value of the section symbol in the input file. This is
1517 // normally zero, but could in principle be something else.
1519 // The start address of this merged section in the output file.
1520 Value output_start_address_
;
1521 // A hash table which maps offsets in the input section to output
1522 // addresses. This only maps specific offsets, not all offsets.
1523 Output_addresses output_addresses_
;
1526 // This POD class is holds the value of a symbol. This is used for
1527 // local symbols, and for all symbols during relocation processing.
1528 // For special sections, such as SHF_MERGE sections, this calls a
1529 // function to get the final symbol value.
1535 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1538 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1539 is_ordinary_shndx_(false), is_section_symbol_(false),
1540 is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
1541 { this->u_
.value
= 0; }
1545 if (!this->has_output_value_
)
1546 delete this->u_
.merged_symbol_value
;
1549 // Get the value of this symbol. OBJECT is the object in which this
1550 // symbol is defined, and ADDEND is an addend to add to the value.
1551 template<bool big_endian
>
1553 value(const Sized_relobj_file
<size
, big_endian
>* object
, Value addend
) const
1555 if (this->has_output_value_
)
1556 return this->u_
.value
+ addend
;
1559 gold_assert(this->is_ordinary_shndx_
);
1560 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1565 // Set the value of this symbol in the output symbol table.
1567 set_output_value(Value value
)
1568 { this->u_
.value
= value
; }
1570 // For a section symbol in a merged section, we need more
1573 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1575 gold_assert(this->is_section_symbol_
);
1576 this->has_output_value_
= false;
1577 this->u_
.merged_symbol_value
= msv
;
1580 // Initialize the input to output map for a section symbol in a
1581 // merged section. We also initialize the value of a non-section
1582 // symbol in a merged section.
1584 initialize_input_to_output_map(const Relobj
* object
)
1586 if (!this->has_output_value_
)
1588 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1589 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1590 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1594 // Free the input to output map for a section symbol in a merged
1597 free_input_to_output_map()
1599 if (!this->has_output_value_
)
1600 this->u_
.merged_symbol_value
->free_input_to_output_map();
1603 // Set the value of the symbol from the input file. This is only
1604 // called by count_local_symbols, to communicate the value to
1605 // finalize_local_symbols.
1607 set_input_value(Value value
)
1608 { this->u_
.value
= value
; }
1610 // Return the input value. This is only called by
1611 // finalize_local_symbols and (in special cases) relocate_section.
1614 { return this->u_
.value
; }
1616 // Return whether we have set the index in the output symbol table
1619 is_output_symtab_index_set() const
1621 return (this->output_symtab_index_
!= 0
1622 && this->output_symtab_index_
!= -2U);
1625 // Return whether this symbol may be discarded from the normal
1628 may_be_discarded_from_output_symtab() const
1630 gold_assert(!this->is_output_symtab_index_set());
1631 return this->output_symtab_index_
!= -2U;
1634 // Return whether this symbol has an entry in the output symbol
1637 has_output_symtab_entry() const
1639 gold_assert(this->is_output_symtab_index_set());
1640 return this->output_symtab_index_
!= -1U;
1643 // Return the index in the output symbol table.
1645 output_symtab_index() const
1647 gold_assert(this->is_output_symtab_index_set()
1648 && this->output_symtab_index_
!= -1U);
1649 return this->output_symtab_index_
;
1652 // Set the index in the output symbol table.
1654 set_output_symtab_index(unsigned int i
)
1656 gold_assert(!this->is_output_symtab_index_set());
1657 gold_assert(i
!= 0 && i
!= -1U && i
!= -2U);
1658 this->output_symtab_index_
= i
;
1661 // Record that this symbol should not go into the output symbol
1664 set_no_output_symtab_entry()
1666 gold_assert(this->output_symtab_index_
== 0);
1667 this->output_symtab_index_
= -1U;
1670 // Record that this symbol must go into the output symbol table,
1671 // because it there is a relocation that uses it.
1673 set_must_have_output_symtab_entry()
1675 gold_assert(!this->is_output_symtab_index_set());
1676 this->output_symtab_index_
= -2U;
1679 // Set the index in the output dynamic symbol table.
1681 set_needs_output_dynsym_entry()
1683 gold_assert(!this->is_section_symbol());
1684 this->output_dynsym_index_
= 0;
1687 // Return whether this symbol should go into the dynamic symbol
1690 needs_output_dynsym_entry() const
1692 return this->output_dynsym_index_
!= -1U;
1695 // Return whether this symbol has an entry in the dynamic symbol
1698 has_output_dynsym_entry() const
1700 gold_assert(this->output_dynsym_index_
!= 0);
1701 return this->output_dynsym_index_
!= -1U;
1704 // Record that this symbol should go into the dynamic symbol table.
1706 set_output_dynsym_index(unsigned int i
)
1708 gold_assert(this->output_dynsym_index_
== 0);
1709 gold_assert(i
!= 0 && i
!= -1U);
1710 this->output_dynsym_index_
= i
;
1713 // Return the index in the output dynamic symbol table.
1715 output_dynsym_index() const
1717 gold_assert(this->output_dynsym_index_
!= 0
1718 && this->output_dynsym_index_
!= -1U);
1719 return this->output_dynsym_index_
;
1722 // Set the index of the input section in the input file.
1724 set_input_shndx(unsigned int i
, bool is_ordinary
)
1726 this->input_shndx_
= i
;
1727 // input_shndx_ field is a bitfield, so make sure that the value
1729 gold_assert(this->input_shndx_
== i
);
1730 this->is_ordinary_shndx_
= is_ordinary
;
1733 // Return the index of the input section in the input file.
1735 input_shndx(bool* is_ordinary
) const
1737 *is_ordinary
= this->is_ordinary_shndx_
;
1738 return this->input_shndx_
;
1741 // Whether this is a section symbol.
1743 is_section_symbol() const
1744 { return this->is_section_symbol_
; }
1746 // Record that this is a section symbol.
1748 set_is_section_symbol()
1750 gold_assert(!this->needs_output_dynsym_entry());
1751 this->is_section_symbol_
= true;
1754 // Record that this is a TLS symbol.
1757 { this->is_tls_symbol_
= true; }
1759 // Return true if this is a TLS symbol.
1761 is_tls_symbol() const
1762 { return this->is_tls_symbol_
; }
1764 // Record that this is an IFUNC symbol.
1766 set_is_ifunc_symbol()
1767 { this->is_ifunc_symbol_
= true; }
1769 // Return true if this is an IFUNC symbol.
1771 is_ifunc_symbol() const
1772 { return this->is_ifunc_symbol_
; }
1774 // Return true if this has output value.
1776 has_output_value() const
1777 { return this->has_output_value_
; }
1780 // The index of this local symbol in the output symbol table. This
1781 // will be 0 if no value has been assigned yet, and the symbol may
1782 // be omitted. This will be -1U if the symbol should not go into
1783 // the symbol table. This will be -2U if the symbol must go into
1784 // the symbol table, but no index has been assigned yet.
1785 unsigned int output_symtab_index_
;
1786 // The index of this local symbol in the dynamic symbol table. This
1787 // will be -1U if the symbol should not go into the symbol table.
1788 unsigned int output_dynsym_index_
;
1789 // The section index in the input file in which this symbol is
1791 unsigned int input_shndx_
: 27;
1792 // Whether the section index is an ordinary index, not a special
1794 bool is_ordinary_shndx_
: 1;
1795 // Whether this is a STT_SECTION symbol.
1796 bool is_section_symbol_
: 1;
1797 // Whether this is a STT_TLS symbol.
1798 bool is_tls_symbol_
: 1;
1799 // Whether this is a STT_GNU_IFUNC symbol.
1800 bool is_ifunc_symbol_
: 1;
1801 // Whether this symbol has a value for the output file. This is
1802 // normally set to true during Layout::finalize, by
1803 // finalize_local_symbols. It will be false for a section symbol in
1804 // a merge section, as for such symbols we can not determine the
1805 // value to use in a relocation until we see the addend.
1806 bool has_output_value_
: 1;
1809 // This is used if has_output_value_ is true. Between
1810 // count_local_symbols and finalize_local_symbols, this is the
1811 // value in the input file. After finalize_local_symbols, it is
1812 // the value in the output file.
1814 // This is used if has_output_value_ is false. It points to the
1815 // information we need to get the value for a merge section.
1816 Merged_symbol_value
<size
>* merged_symbol_value
;
1820 // This type is used to modify relocations for -fsplit-stack. It is
1821 // indexed by relocation index, and means that the relocation at that
1822 // index should use the symbol from the vector, rather than the one
1823 // indicated by the relocation.
1825 class Reloc_symbol_changes
1828 Reloc_symbol_changes(size_t count
)
1833 set(size_t i
, Symbol
* sym
)
1834 { this->vec_
[i
] = sym
; }
1837 operator[](size_t i
) const
1838 { return this->vec_
[i
]; }
1841 std::vector
<Symbol
*> vec_
;
1844 // Type for mapping section index to uncompressed size and contents.
1846 struct Compressed_section_info
1848 section_size_type size
;
1849 const unsigned char* contents
;
1851 typedef std::map
<unsigned int, Compressed_section_info
> Compressed_section_map
;
1853 // Abstract base class for a regular object file, either a real object file
1854 // or an incremental (unchanged) object. This is size and endian specific.
1856 template<int size
, bool big_endian
>
1857 class Sized_relobj
: public Relobj
1860 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1861 typedef Relobj::Symbols Symbols
;
1863 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1865 Sized_relobj(const std::string
& name
, Input_file
* input_file
)
1866 : Relobj(name
, input_file
), local_got_offsets_(), section_offsets_()
1869 Sized_relobj(const std::string
& name
, Input_file
* input_file
,
1871 : Relobj(name
, input_file
, offset
), local_got_offsets_(), section_offsets_()
1877 // If this is a regular object, return a pointer to the Sized_relobj_file
1878 // object. Otherwise, return NULL.
1879 virtual Sized_relobj_file
<size
, big_endian
>*
1883 const virtual Sized_relobj_file
<size
, big_endian
>*
1884 sized_relobj() const
1887 // Checks if the offset of input section SHNDX within its output
1888 // section is invalid.
1890 is_output_section_offset_invalid(unsigned int shndx
) const
1891 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1893 // Get the offset of input section SHNDX within its output section.
1894 // This is -1 if the input section requires a special mapping, such
1895 // as a merge section. The output section can be found in the
1896 // output_sections_ field of the parent class Relobj.
1898 get_output_section_offset(unsigned int shndx
) const
1900 gold_assert(shndx
< this->section_offsets_
.size());
1901 return this->section_offsets_
[shndx
];
1904 // Iterate over local symbols, calling a visitor class V for each GOT offset
1905 // associated with a local symbol.
1907 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const;
1910 typedef Relobj::Output_sections Output_sections
;
1912 // Clear the local symbol information.
1915 { this->local_got_offsets_
.clear(); }
1917 // Return the vector of section offsets.
1918 std::vector
<Address
>&
1920 { return this->section_offsets_
; }
1922 // Get the offset of a section.
1924 do_output_section_offset(unsigned int shndx
) const
1926 Address off
= this->get_output_section_offset(shndx
);
1927 if (off
== invalid_address
)
1932 // Set the offset of a section.
1934 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1936 gold_assert(shndx
< this->section_offsets_
.size());
1937 this->section_offsets_
[shndx
] =
1938 (off
== static_cast<uint64_t>(-1)
1940 : convert_types
<Address
, uint64_t>(off
));
1943 // Return whether the local symbol SYMNDX has a GOT offset of type
1946 do_local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1948 Local_got_offsets::const_iterator p
=
1949 this->local_got_offsets_
.find(symndx
);
1950 return (p
!= this->local_got_offsets_
.end()
1951 && p
->second
->get_offset(got_type
) != -1U);
1954 // Return the GOT offset of type GOT_TYPE of the local symbol
1957 do_local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1959 Local_got_offsets::const_iterator p
=
1960 this->local_got_offsets_
.find(symndx
);
1961 gold_assert(p
!= this->local_got_offsets_
.end());
1962 unsigned int off
= p
->second
->get_offset(got_type
);
1963 gold_assert(off
!= -1U);
1967 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1970 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1971 unsigned int got_offset
)
1973 Local_got_offsets::const_iterator p
=
1974 this->local_got_offsets_
.find(symndx
);
1975 if (p
!= this->local_got_offsets_
.end())
1976 p
->second
->set_offset(got_type
, got_offset
);
1979 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1980 std::pair
<Local_got_offsets::iterator
, bool> ins
=
1981 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
1982 gold_assert(ins
.second
);
1986 // Return the word size of the object file.
1991 // Return TRUE if this is a big-endian object file.
1993 do_is_big_endian() const
1994 { return big_endian
; }
1997 // The GOT offsets of local symbols. This map also stores GOT offsets
1998 // for tp-relative offsets for TLS symbols.
1999 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
2001 // GOT offsets for local non-TLS symbols, and tp-relative offsets
2002 // for TLS symbols, indexed by symbol number.
2003 Local_got_offsets local_got_offsets_
;
2004 // For each input section, the offset of the input section in its
2005 // output section. This is INVALID_ADDRESS if the input section requires a
2007 std::vector
<Address
> section_offsets_
;
2010 // A regular object file. This is size and endian specific.
2012 template<int size
, bool big_endian
>
2013 class Sized_relobj_file
: public Sized_relobj
<size
, big_endian
>
2016 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
2017 typedef typename Sized_relobj
<size
, big_endian
>::Symbols Symbols
;
2018 typedef std::vector
<Symbol_value
<size
> > Local_values
;
2020 static const Address invalid_address
= static_cast<Address
>(0) - 1;
2022 enum Compute_final_local_value_status
2026 // An error occurred.
2028 // The local symbol has no output section.
2032 Sized_relobj_file(const std::string
& name
,
2033 Input_file
* input_file
,
2035 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
2037 ~Sized_relobj_file();
2039 // Set up the object file based on TARGET.
2042 { this->do_setup(); }
2044 // Return a pointer to the Sized_relobj_file object.
2045 Sized_relobj_file
<size
, big_endian
>*
2049 const Sized_relobj_file
<size
, big_endian
>*
2050 sized_relobj() const
2053 // Return the ELF file type.
2056 { return this->e_type_
; }
2058 // Return the number of symbols. This is only valid after
2059 // Object::add_symbols has been called.
2061 symbol_count() const
2062 { return this->local_symbol_count_
+ this->symbols_
.size(); }
2064 // If SYM is the index of a global symbol in the object file's
2065 // symbol table, return the Symbol object. Otherwise, return NULL.
2067 global_symbol(unsigned int sym
) const
2069 if (sym
>= this->local_symbol_count_
)
2071 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
2072 return this->symbols_
[sym
- this->local_symbol_count_
];
2077 // Return the section index of symbol SYM. Set *VALUE to its value
2078 // in the object file. Set *IS_ORDINARY if this is an ordinary
2079 // section index, not a special code between SHN_LORESERVE and
2080 // SHN_HIRESERVE. Note that for a symbol which is not defined in
2081 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
2082 // it will not return the final value of the symbol in the link.
2084 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
2086 // Return a pointer to the Symbol_value structure which holds the
2087 // value of a local symbol.
2088 const Symbol_value
<size
>*
2089 local_symbol(unsigned int sym
) const
2091 gold_assert(sym
< this->local_values_
.size());
2092 return &this->local_values_
[sym
];
2095 // Return the index of local symbol SYM in the ordinary symbol
2096 // table. A value of -1U means that the symbol is not being output.
2098 symtab_index(unsigned int sym
) const
2100 gold_assert(sym
< this->local_values_
.size());
2101 return this->local_values_
[sym
].output_symtab_index();
2104 // Return the index of local symbol SYM in the dynamic symbol
2105 // table. A value of -1U means that the symbol is not being output.
2107 dynsym_index(unsigned int sym
) const
2109 gold_assert(sym
< this->local_values_
.size());
2110 return this->local_values_
[sym
].output_dynsym_index();
2113 // Return the input section index of local symbol SYM.
2115 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
2117 gold_assert(sym
< this->local_values_
.size());
2118 return this->local_values_
[sym
].input_shndx(is_ordinary
);
2121 // Record that local symbol SYM must be in the output symbol table.
2123 set_must_have_output_symtab_entry(unsigned int sym
)
2125 gold_assert(sym
< this->local_values_
.size());
2126 this->local_values_
[sym
].set_must_have_output_symtab_entry();
2129 // Record that local symbol SYM needs a dynamic symbol entry.
2131 set_needs_output_dynsym_entry(unsigned int sym
)
2133 gold_assert(sym
< this->local_values_
.size());
2134 this->local_values_
[sym
].set_needs_output_dynsym_entry();
2137 // Return whether the local symbol SYMNDX has a PLT offset.
2139 local_has_plt_offset(unsigned int symndx
) const;
2141 // Set the PLT offset of the local symbol SYMNDX.
2143 set_local_plt_offset(unsigned int symndx
, unsigned int plt_offset
);
2145 // Adjust this local symbol value. Return false if the symbol
2146 // should be discarded from the output file.
2148 adjust_local_symbol(Symbol_value
<size
>* lv
) const
2149 { return this->do_adjust_local_symbol(lv
); }
2151 // Return the name of the symbol that spans the given offset in the
2152 // specified section in this object. This is used only for error
2153 // messages and is not particularly efficient.
2155 get_symbol_location_info(unsigned int shndx
, off_t offset
,
2156 Symbol_location_info
* info
);
2158 // Look for a kept section corresponding to the given discarded section,
2159 // and return its output address. This is used only for relocations in
2160 // debugging sections.
2162 map_to_kept_section(unsigned int shndx
, bool* found
) const;
2164 // Find the section header with the given NAME. If HDR is non-NULL
2165 // then it is a section header returned from a previous call to this
2166 // function and the next section header with the same name will be
2168 const unsigned char*
2169 find_shdr(const unsigned char* pshdrs
, const char* name
,
2170 const char* names
, section_size_type names_size
,
2171 const unsigned char* hdr
) const;
2173 // Compute final local symbol value. R_SYM is the local symbol index.
2174 // LV_IN points to a local symbol value containing the input value.
2175 // LV_OUT points to a local symbol value storing the final output value,
2176 // which must not be a merged symbol value since before calling this
2177 // method to avoid memory leak. SYMTAB points to a symbol table.
2179 // The method returns a status code at return. If the return status is
2180 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2181 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2182 // *LV_OUT is not modified.
2183 Compute_final_local_value_status
2184 compute_final_local_value(unsigned int r_sym
,
2185 const Symbol_value
<size
>* lv_in
,
2186 Symbol_value
<size
>* lv_out
,
2187 const Symbol_table
* symtab
);
2190 typedef typename Sized_relobj
<size
, big_endian
>::Output_sections
2197 // Read the symbols.
2199 do_read_symbols(Read_symbols_data
*);
2201 // Return the value of a local symbol.
2203 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const
2205 const Symbol_value
<size
>* symval
= this->local_symbol(symndx
);
2206 return symval
->value(this, addend
);
2209 // Return the PLT offset for a local symbol. It is an error to call
2210 // this if it doesn't have one.
2212 do_local_plt_offset(unsigned int symndx
) const;
2214 // Return whether local symbol SYMNDX is a TLS symbol.
2216 do_local_is_tls(unsigned int symndx
) const
2217 { return this->local_symbol(symndx
)->is_tls_symbol(); }
2219 // Return the number of local symbols.
2221 do_local_symbol_count() const
2222 { return this->local_symbol_count_
; }
2224 // Return the number of local symbols in the output symbol table.
2226 do_output_local_symbol_count() const
2227 { return this->output_local_symbol_count_
; }
2229 // Return the number of local symbols in the output symbol table.
2231 do_local_symbol_offset() const
2232 { return this->local_symbol_offset_
; }
2234 // Lay out the input sections.
2236 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
2238 // Layout sections whose layout was deferred while waiting for
2239 // input files from a plugin.
2241 do_layout_deferred_sections(Layout
*);
2243 // Add the symbols to the symbol table.
2245 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
2247 Archive::Should_include
2248 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
2251 // Iterate over global symbols, calling a visitor class V for each.
2253 do_for_all_global_symbols(Read_symbols_data
* sd
,
2254 Library_base::Symbol_visitor_base
* v
);
2258 do_read_relocs(Read_relocs_data
*);
2260 // Process the relocs to find list of referenced sections. Used only
2261 // during garbage collection.
2263 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2265 // Scan the relocs and adjust the symbol table.
2267 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2269 // Count the local symbols.
2271 do_count_local_symbols(Stringpool_template
<char>*,
2272 Stringpool_template
<char>*);
2274 // Finalize the local symbols.
2276 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
2278 // Set the offset where local dynamic symbol information will be stored.
2280 do_set_local_dynsym_indexes(unsigned int);
2282 // Set the offset where local dynamic symbol information will be stored.
2284 do_set_local_dynsym_offset(off_t
);
2286 // Relocate the input sections and write out the local symbols.
2288 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
2290 // Get the size of a section.
2292 do_section_size(unsigned int shndx
)
2293 { return this->elf_file_
.section_size(shndx
); }
2295 // Get the name of a section.
2297 do_section_name(unsigned int shndx
)
2298 { return this->elf_file_
.section_name(shndx
); }
2300 // Return the location of the contents of a section.
2301 const unsigned char*
2302 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
2305 Object::Location
loc(this->elf_file_
.section_contents(shndx
));
2306 *plen
= convert_to_section_size_type(loc
.data_size
);
2309 static const unsigned char empty
[1] = { '\0' };
2312 return this->get_view(loc
.file_offset
, *plen
, true, cache
);
2315 // Return section flags.
2317 do_section_flags(unsigned int shndx
);
2319 // Return section entsize.
2321 do_section_entsize(unsigned int shndx
);
2323 // Return section address.
2325 do_section_address(unsigned int shndx
)
2326 { return this->elf_file_
.section_addr(shndx
); }
2328 // Return section type.
2330 do_section_type(unsigned int shndx
)
2331 { return this->elf_file_
.section_type(shndx
); }
2333 // Return the section link field.
2335 do_section_link(unsigned int shndx
)
2336 { return this->elf_file_
.section_link(shndx
); }
2338 // Return the section info field.
2340 do_section_info(unsigned int shndx
)
2341 { return this->elf_file_
.section_info(shndx
); }
2343 // Return the section alignment.
2345 do_section_addralign(unsigned int shndx
)
2346 { return this->elf_file_
.section_addralign(shndx
); }
2348 // Return the Xindex structure to use.
2350 do_initialize_xindex();
2352 // Get symbol counts.
2354 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
2356 // Get the global symbols.
2358 do_get_global_symbols() const
2359 { return &this->symbols_
; }
2361 // Adjust a section index if necessary.
2363 adjust_shndx(unsigned int shndx
)
2365 if (shndx
>= elfcpp::SHN_LORESERVE
)
2366 shndx
+= this->elf_file_
.large_shndx_offset();
2370 // Initialize input to output maps for section symbols in merged
2373 initialize_input_to_output_maps();
2375 // Free the input to output maps for section symbols in merged
2378 free_input_to_output_maps();
2380 // Return symbol table section index.
2382 symtab_shndx() const
2383 { return this->symtab_shndx_
; }
2385 // Allow a child class to access the ELF file.
2386 elfcpp::Elf_file
<size
, big_endian
, Object
>*
2388 { return &this->elf_file_
; }
2390 // Allow a child class to access the local values.
2393 { return &this->local_values_
; }
2395 // Views and sizes when relocating.
2398 unsigned char* view
;
2399 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
2401 section_size_type view_size
;
2402 bool is_input_output_view
;
2403 bool is_postprocessing_view
;
2404 bool is_ctors_reverse_view
;
2407 typedef std::vector
<View_size
> Views
;
2409 // Stash away info for a number of special sections.
2410 // Return true if any of the sections found require local symbols to be read.
2412 do_find_special_sections(Read_symbols_data
* sd
);
2414 // This may be overriden by a child class.
2416 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2417 const unsigned char* pshdrs
, Output_file
* of
,
2420 // Adjust this local symbol value. Return false if the symbol
2421 // should be discarded from the output file.
2423 do_adjust_local_symbol(Symbol_value
<size
>*) const
2426 // Allow a child to set output local symbol count.
2428 set_output_local_symbol_count(unsigned int value
)
2429 { this->output_local_symbol_count_
= value
; }
2431 // Return TRUE if the section is a compressed debug section, and set
2432 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
2434 do_section_is_compressed(unsigned int shndx
,
2435 section_size_type
* uncompressed_size
) const
2437 if (this->compressed_sections_
== NULL
)
2439 Compressed_section_map::const_iterator p
=
2440 this->compressed_sections_
->find(shndx
);
2441 if (p
!= this->compressed_sections_
->end())
2443 if (uncompressed_size
!= NULL
)
2444 *uncompressed_size
= p
->second
.size
;
2450 // Return a view of the uncompressed contents of a section. Set *PLEN
2451 // to the size. Set *IS_NEW to true if the contents need to be deleted
2453 const unsigned char*
2454 do_decompressed_section_contents(unsigned int shndx
,
2455 section_size_type
* plen
,
2458 // Discard any buffers of decompressed sections. This is done
2459 // at the end of the Add_symbols task.
2461 do_discard_decompressed_sections();
2465 typedef Sized_relobj_file
<size
, big_endian
> This
;
2466 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
2467 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2468 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2469 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
2471 // To keep track of discarded comdat sections, we need to map a member
2472 // section index to the object and section index of the corresponding
2474 struct Kept_comdat_section
2476 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
2477 : object(a_object
), shndx(a_shndx
)
2482 typedef std::map
<unsigned int, Kept_comdat_section
>
2483 Kept_comdat_section_table
;
2485 // Find the SHT_SYMTAB section, given the section headers.
2487 find_symtab(const unsigned char* pshdrs
);
2489 // Return whether SHDR has the right flags for a GNU style exception
2492 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
2494 // Return whether there is a section named .eh_frame which might be
2495 // a GNU style exception frame section.
2497 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
2498 section_size_type names_size
) const;
2500 // Whether to include a section group in the link.
2502 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
2503 const unsigned char*, const char*, section_size_type
,
2504 std::vector
<bool>*);
2506 // Whether to include a linkonce section in the link.
2508 include_linkonce_section(Layout
*, unsigned int, const char*,
2509 const elfcpp::Shdr
<size
, big_endian
>&);
2511 // Layout an input section.
2513 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
2514 const typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
2515 unsigned int reloc_type
);
2517 // Layout an input .eh_frame section.
2519 layout_eh_frame_section(Layout
* layout
, const unsigned char* symbols_data
,
2520 section_size_type symbols_size
,
2521 const unsigned char* symbol_names_data
,
2522 section_size_type symbol_names_size
,
2523 unsigned int shndx
, const typename
This::Shdr
&,
2524 unsigned int reloc_shndx
, unsigned int reloc_type
);
2526 // Write section data to the output file. Record the views and
2527 // sizes in VIEWS for use when relocating.
2529 write_sections(const Layout
*, const unsigned char* pshdrs
, Output_file
*,
2532 // Relocate the sections in the output file.
2534 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2535 const unsigned char* pshdrs
, Output_file
* of
,
2537 { this->do_relocate_sections(symtab
, layout
, pshdrs
, of
, pviews
); }
2539 // Reverse the words in a section. Used for .ctors sections mapped
2540 // to .init_array sections.
2542 reverse_words(unsigned char*, section_size_type
);
2544 // Scan the input relocations for --emit-relocs.
2546 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
2547 const Read_relocs_data::Relocs_list::iterator
&);
2549 // Scan the input relocations for --emit-relocs, templatized on the
2550 // type of the relocation section.
2551 template<int sh_type
>
2553 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
2554 const unsigned char* plocal_syms
,
2555 const Read_relocs_data::Relocs_list::iterator
&,
2556 Relocatable_relocs
*);
2558 // Scan the input relocations for --incremental.
2560 incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator
&);
2562 // Scan the input relocations for --incremental, templatized on the
2563 // type of the relocation section.
2564 template<int sh_type
>
2566 incremental_relocs_scan_reltype(
2567 const Read_relocs_data::Relocs_list::iterator
&);
2570 incremental_relocs_write(const Relocate_info
<size
, big_endian
>*,
2571 unsigned int sh_type
,
2572 const unsigned char* prelocs
,
2575 Address output_offset
,
2578 template<int sh_type
>
2580 incremental_relocs_write_reltype(const Relocate_info
<size
, big_endian
>*,
2581 const unsigned char* prelocs
,
2584 Address output_offset
,
2587 // A type shared by split_stack_adjust_reltype and find_functions.
2588 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
2590 // Check for -fsplit-stack routines calling non-split-stack routines.
2592 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
2593 unsigned int sh_type
, unsigned int shndx
,
2594 const unsigned char* prelocs
, size_t reloc_count
,
2595 unsigned char* view
, section_size_type view_size
,
2596 Reloc_symbol_changes
** reloc_map
);
2598 template<int sh_type
>
2600 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
2601 unsigned int shndx
, const unsigned char* prelocs
,
2602 size_t reloc_count
, unsigned char* view
,
2603 section_size_type view_size
,
2604 Reloc_symbol_changes
** reloc_map
);
2606 // Find all functions in a section.
2608 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
2611 // Write out the local symbols.
2613 write_local_symbols(Output_file
*,
2614 const Stringpool_template
<char>*,
2615 const Stringpool_template
<char>*,
2616 Output_symtab_xindex
*,
2617 Output_symtab_xindex
*,
2620 // Record a mapping from discarded section SHNDX to the corresponding
2623 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
2624 unsigned int kept_shndx
)
2626 Kept_comdat_section
kept(kept_object
, kept_shndx
);
2627 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
2630 // Find the kept section corresponding to the discarded section
2631 // SHNDX. Return true if found.
2633 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
2634 unsigned int* kept_shndx
) const
2636 typename
Kept_comdat_section_table::const_iterator p
=
2637 this->kept_comdat_sections_
.find(shndx
);
2638 if (p
== this->kept_comdat_sections_
.end())
2640 *kept_object
= p
->second
.object
;
2641 *kept_shndx
= p
->second
.shndx
;
2645 // Compute final local symbol value. R_SYM is the local symbol index.
2646 // LV_IN points to a local symbol value containing the input value.
2647 // LV_OUT points to a local symbol value storing the final output value,
2648 // which must not be a merged symbol value since before calling this
2649 // method to avoid memory leak. RELOCATABLE indicates whether we are
2650 // linking a relocatable output. OUT_SECTIONS is an array of output
2651 // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
2652 // points to a symbol table.
2654 // The method returns a status code at return. If the return status is
2655 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2656 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2657 // *LV_OUT is not modified.
2658 inline Compute_final_local_value_status
2659 compute_final_local_value_internal(unsigned int r_sym
,
2660 const Symbol_value
<size
>* lv_in
,
2661 Symbol_value
<size
>* lv_out
,
2663 const Output_sections
& out_sections
,
2664 const std::vector
<Address
>& out_offsets
,
2665 const Symbol_table
* symtab
);
2667 // The PLT offsets of local symbols.
2668 typedef Unordered_map
<unsigned int, unsigned int> Local_plt_offsets
;
2670 // Saved information for sections whose layout was deferred.
2671 struct Deferred_layout
2673 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2674 Deferred_layout(unsigned int shndx
, const char* name
,
2675 const unsigned char* pshdr
,
2676 unsigned int reloc_shndx
, unsigned int reloc_type
)
2677 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
2678 reloc_type_(reloc_type
)
2680 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
2682 unsigned int shndx_
;
2684 unsigned int reloc_shndx_
;
2685 unsigned int reloc_type_
;
2686 unsigned char shdr_data_
[shdr_size
];
2689 // General access to the ELF file.
2690 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
2691 // Type of ELF file (ET_REL or ET_EXEC). ET_EXEC files are allowed
2692 // as input files only for the --just-symbols option.
2694 // Index of SHT_SYMTAB section.
2695 unsigned int symtab_shndx_
;
2696 // The number of local symbols.
2697 unsigned int local_symbol_count_
;
2698 // The number of local symbols which go into the output file.
2699 unsigned int output_local_symbol_count_
;
2700 // The number of local symbols which go into the output file's dynamic
2702 unsigned int output_local_dynsym_count_
;
2703 // The entries in the symbol table for the external symbols.
2705 // Number of symbols defined in object file itself.
2706 size_t defined_count_
;
2707 // File offset for local symbols (relative to start of symbol table).
2708 off_t local_symbol_offset_
;
2709 // File offset for local dynamic symbols (absolute).
2710 off_t local_dynsym_offset_
;
2711 // Values of local symbols.
2712 Local_values local_values_
;
2713 // PLT offsets for local symbols.
2714 Local_plt_offsets local_plt_offsets_
;
2715 // Table mapping discarded comdat sections to corresponding kept sections.
2716 Kept_comdat_section_table kept_comdat_sections_
;
2717 // Whether this object has a GNU style .eh_frame section.
2719 // If this object has a GNU style .eh_frame section that is discarded in
2720 // output, record the index here. Otherwise it is -1U.
2721 unsigned int discarded_eh_frame_shndx_
;
2722 // The list of sections whose layout was deferred.
2723 std::vector
<Deferred_layout
> deferred_layout_
;
2724 // The list of relocation sections whose layout was deferred.
2725 std::vector
<Deferred_layout
> deferred_layout_relocs_
;
2726 // For compressed debug sections, map section index to uncompressed size
2728 Compressed_section_map
* compressed_sections_
;
2731 // A class to manage the list of all objects.
2737 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
2740 // The type of the list of input relocateable objects.
2741 typedef std::vector
<Relobj
*> Relobj_list
;
2742 typedef Relobj_list::const_iterator Relobj_iterator
;
2744 // The type of the list of input dynamic objects.
2745 typedef std::vector
<Dynobj
*> Dynobj_list
;
2746 typedef Dynobj_list::const_iterator Dynobj_iterator
;
2748 // Add an object to the list. Return true if all is well, or false
2749 // if this object should be ignored.
2751 add_object(Object
*);
2753 // Start processing an archive.
2755 archive_start(Archive
*);
2757 // Stop processing an archive.
2759 archive_stop(Archive
*);
2761 // For each dynamic object, check whether we've seen all of its
2762 // explicit dependencies.
2764 check_dynamic_dependencies() const;
2766 // Return whether an object was found in the system library
2769 found_in_system_library_directory(const Object
*) const;
2771 // Print symbol counts.
2773 print_symbol_counts(const Symbol_table
*) const;
2775 // Print a cross reference table.
2777 print_cref(const Symbol_table
*, FILE*) const;
2779 // Iterate over all regular objects.
2782 relobj_begin() const
2783 { return this->relobj_list_
.begin(); }
2787 { return this->relobj_list_
.end(); }
2789 // Iterate over all dynamic objects.
2792 dynobj_begin() const
2793 { return this->dynobj_list_
.begin(); }
2797 { return this->dynobj_list_
.end(); }
2799 // Return whether we have seen any dynamic objects.
2802 { return !this->dynobj_list_
.empty(); }
2804 // Return the number of non dynamic objects.
2806 number_of_relobjs() const
2807 { return this->relobj_list_
.size(); }
2809 // Return the number of input objects.
2811 number_of_input_objects() const
2812 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
2815 Input_objects(const Input_objects
&);
2816 Input_objects
& operator=(const Input_objects
&);
2818 // The list of ordinary objects included in the link.
2819 Relobj_list relobj_list_
;
2820 // The list of dynamic objects included in the link.
2821 Dynobj_list dynobj_list_
;
2822 // SONAMEs that we have seen.
2823 Unordered_set
<std::string
> sonames_
;
2824 // Manage cross-references if requested.
2828 // Some of the information we pass to the relocation routines. We
2829 // group this together to avoid passing a dozen different arguments.
2831 template<int size
, bool big_endian
>
2832 struct Relocate_info
2835 const Symbol_table
* symtab
;
2837 const Layout
* layout
;
2838 // Object being relocated.
2839 Sized_relobj_file
<size
, big_endian
>* object
;
2840 // Section index of relocation section.
2841 unsigned int reloc_shndx
;
2842 // Section header of relocation section.
2843 const unsigned char* reloc_shdr
;
2844 // Section index of section being relocated.
2845 unsigned int data_shndx
;
2846 // Section header of data section.
2847 const unsigned char* data_shdr
;
2849 // Return a string showing the location of a relocation. This is
2850 // only used for error messages.
2852 location(size_t relnum
, off_t reloffset
) const;
2855 // This is used to represent a section in an object and is used as the
2856 // key type for various section maps.
2857 typedef std::pair
<Object
*, unsigned int> Section_id
;
2859 // This is similar to Section_id but is used when the section
2860 // pointers are const.
2861 typedef std::pair
<const Object
*, unsigned int> Const_section_id
;
2863 // The hash value is based on the address of an object in memory during
2864 // linking. It is okay to use this for looking up sections but never use
2865 // this in an unordered container that we want to traverse in a repeatable
2868 struct Section_id_hash
2870 size_t operator()(const Section_id
& loc
) const
2871 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2874 struct Const_section_id_hash
2876 size_t operator()(const Const_section_id
& loc
) const
2877 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2880 // Return whether INPUT_FILE contains an ELF object start at file
2881 // offset OFFSET. This sets *START to point to a view of the start of
2882 // the file. It sets *READ_SIZE to the number of bytes in the view.
2885 is_elf_object(Input_file
* input_file
, off_t offset
,
2886 const unsigned char** start
, int* read_size
);
2888 // Return an Object appropriate for the input file. P is BYTES long,
2889 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2890 // this sees an object the linker is not configured to support, it
2891 // sets *PUNCONFIGURED to true and returns NULL without giving an
2895 make_elf_object(const std::string
& name
, Input_file
*,
2896 off_t offset
, const unsigned char* p
,
2897 section_offset_type bytes
, bool* punconfigured
);
2899 } // end namespace gold
2901 #endif // !defined(GOLD_OBJECT_H)