1 // object.h -- support for an object file for linking in gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
30 #include "elfcpp_file.h"
38 class General_options
;
45 class Output_symtab_xindex
;
48 class Object_merge_map
;
49 class Relocatable_relocs
;
52 template<typename Stringpool_char
>
53 class Stringpool_template
;
55 // Data to pass from read_symbols() to add_symbols().
57 struct Read_symbols_data
60 : section_headers(NULL
), section_names(NULL
), symbols(NULL
),
61 symbol_names(NULL
), versym(NULL
), verdef(NULL
), verneed(NULL
)
67 File_view
* section_headers
;
69 File_view
* section_names
;
70 // Size of section name data in bytes.
71 section_size_type section_names_size
;
74 // Size of symbol data in bytes.
75 section_size_type symbols_size
;
76 // Offset of external symbols within symbol data. This structure
77 // sometimes contains only external symbols, in which case this will
78 // be zero. Sometimes it contains all symbols.
79 section_offset_type external_symbols_offset
;
81 File_view
* symbol_names
;
82 // Size of symbol name data in bytes.
83 section_size_type symbol_names_size
;
85 // Version information. This is only used on dynamic objects.
86 // Version symbol data (from SHT_GNU_versym section).
88 section_size_type versym_size
;
89 // Version definition data (from SHT_GNU_verdef section).
91 section_size_type verdef_size
;
92 unsigned int verdef_info
;
93 // Needed version data (from SHT_GNU_verneed section).
95 section_size_type verneed_size
;
96 unsigned int verneed_info
;
99 // Information used to print error messages.
101 struct Symbol_location_info
103 std::string source_file
;
104 std::string enclosing_symbol_name
;
108 // Data about a single relocation section. This is read in
109 // read_relocs and processed in scan_relocs.
111 struct Section_relocs
118 { delete this->contents
; }
120 // Index of reloc section.
121 unsigned int reloc_shndx
;
122 // Index of section that relocs apply to.
123 unsigned int data_shndx
;
124 // Contents of reloc section.
126 // Reloc section type.
127 unsigned int sh_type
;
128 // Number of reloc entries.
131 Output_section
* output_section
;
132 // Whether this section has special handling for offsets.
133 bool needs_special_offset_handling
;
134 // Whether the data section is allocated (has the SHF_ALLOC flag set).
135 bool is_data_section_allocated
;
138 // Relocations in an object file. This is read in read_relocs and
139 // processed in scan_relocs.
141 struct Read_relocs_data
144 : local_symbols(NULL
)
148 { delete this->local_symbols
; }
150 typedef std::vector
<Section_relocs
> Relocs_list
;
153 // The local symbols.
154 File_view
* local_symbols
;
157 // The Xindex class manages section indexes for objects with more than
163 Xindex(int large_shndx_offset
)
164 : large_shndx_offset_(large_shndx_offset
), symtab_xindex_()
167 // Initialize the symtab_xindex_ array, given the object and the
168 // section index of the symbol table to use.
169 template<int size
, bool big_endian
>
171 initialize_symtab_xindex(Object
*, unsigned int symtab_shndx
);
173 // Read in the symtab_xindex_ array, given its section index.
174 // PSHDRS may optionally point to the section headers.
175 template<int size
, bool big_endian
>
177 read_symtab_xindex(Object
*, unsigned int xindex_shndx
,
178 const unsigned char* pshdrs
);
180 // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
181 // real section index.
183 sym_xindex_to_shndx(Object
* object
, unsigned int symndx
);
186 // The type of the array giving the real section index for symbols
187 // whose st_shndx field holds SHN_XINDEX.
188 typedef std::vector
<unsigned int> Symtab_xindex
;
190 // Adjust a section index if necessary. This should only be called
191 // for ordinary section indexes.
193 adjust_shndx(unsigned int shndx
)
195 if (shndx
>= elfcpp::SHN_LORESERVE
)
196 shndx
+= this->large_shndx_offset_
;
200 // Adjust to apply to large section indexes.
201 int large_shndx_offset_
;
202 // The data from the SHT_SYMTAB_SHNDX section.
203 Symtab_xindex symtab_xindex_
;
206 // A GOT offset list. A symbol may have more than one GOT offset
207 // (e.g., when mixing modules compiled with two different TLS models),
208 // but will usually have at most one. GOT_TYPE identifies the type of
209 // GOT entry; its values are specific to each target.
211 class Got_offset_list
215 : got_type_(-1U), got_offset_(0), got_next_(NULL
)
218 Got_offset_list(unsigned int got_type
, unsigned int got_offset
)
219 : got_type_(got_type
), got_offset_(got_offset
), got_next_(NULL
)
224 if (this->got_next_
!= NULL
)
226 delete this->got_next_
;
227 this->got_next_
= NULL
;
231 // Initialize the fields to their default values.
235 this->got_type_
= -1U;
236 this->got_offset_
= 0;
237 this->got_next_
= NULL
;
240 // Set the offset for the GOT entry of type GOT_TYPE.
242 set_offset(unsigned int got_type
, unsigned int got_offset
)
244 if (this->got_type_
== -1U)
246 this->got_type_
= got_type
;
247 this->got_offset_
= got_offset
;
251 for (Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
253 if (g
->got_type_
== got_type
)
255 g
->got_offset_
= got_offset
;
259 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
260 g
->got_next_
= this->got_next_
;
265 // Return the offset for a GOT entry of type GOT_TYPE.
267 get_offset(unsigned int got_type
) const
269 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
271 if (g
->got_type_
== got_type
)
272 return g
->got_offset_
;
277 // Return a pointer to the list, or NULL if the list is empty.
278 const Got_offset_list
*
281 if (this->got_type_
== -1U)
286 // Abstract visitor class for iterating over GOT offsets.
298 visit(unsigned int, unsigned int) = 0;
301 // Loop over all GOT offset entries, calling a visitor class V for each.
303 for_all_got_offsets(Visitor
* v
) const
305 if (this->got_type_
== -1U)
307 for (const Got_offset_list
* g
= this; g
!= NULL
; g
= g
->got_next_
)
308 v
->visit(g
->got_type_
, g
->got_offset_
);
312 unsigned int got_type_
;
313 unsigned int got_offset_
;
314 Got_offset_list
* got_next_
;
317 // Object is an abstract base class which represents either a 32-bit
318 // or a 64-bit input object. This can be a regular object file
319 // (ET_REL) or a shared object (ET_DYN).
324 typedef std::vector
<Symbol
*> Symbols
;
326 // NAME is the name of the object as we would report it to the user
327 // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
328 // used to read the file. OFFSET is the offset within the input
329 // file--0 for a .o or .so file, something else for a .a file.
330 Object(const std::string
& name
, Input_file
* input_file
, bool is_dynamic
,
332 : name_(name
), input_file_(input_file
), offset_(offset
), shnum_(-1U),
333 is_dynamic_(is_dynamic
), is_needed_(false), uses_split_stack_(false),
334 has_no_split_stack_(false), no_export_(false),
335 is_in_system_directory_(false), as_needed_(false), xindex_(NULL
)
337 if (input_file
!= NULL
)
339 input_file
->file().add_object();
340 this->is_in_system_directory_
= input_file
->is_in_system_directory();
341 this->as_needed_
= input_file
->options().as_needed();
347 if (this->input_file_
!= NULL
)
348 this->input_file_
->file().remove_object();
351 // Return the name of the object as we would report it to the tuser.
354 { return this->name_
; }
356 // Get the offset into the file.
359 { return this->offset_
; }
361 // Return whether this is a dynamic object.
364 { return this->is_dynamic_
; }
366 // Return whether this object is needed--true if it is a dynamic
367 // object which defines some symbol referenced by a regular object.
368 // We keep the flag here rather than in Dynobj for convenience when
372 { return this->is_needed_
; }
374 // Record that this object is needed.
377 { this->is_needed_
= true; }
379 // Return whether this object was compiled with -fsplit-stack.
381 uses_split_stack() const
382 { return this->uses_split_stack_
; }
384 // Return whether this object contains any functions compiled with
385 // the no_split_stack attribute.
387 has_no_split_stack() const
388 { return this->has_no_split_stack_
; }
390 // Returns NULL for Objects that are not dynamic objects. This method
391 // is overridden in the Dynobj class.
394 { return this->do_dynobj(); }
396 // Returns NULL for Objects that are not plugin objects. This method
397 // is overridden in the Pluginobj class.
400 { return this->do_pluginobj(); }
402 // Get the file. We pass on const-ness.
406 gold_assert(this->input_file_
!= NULL
);
407 return this->input_file_
;
413 gold_assert(this->input_file_
!= NULL
);
414 return this->input_file_
;
417 // Lock the underlying file.
421 if (this->input_file_
!= NULL
)
422 this->input_file_
->file().lock(t
);
425 // Unlock the underlying file.
427 unlock(const Task
* t
)
429 if (this->input_file_
!= NULL
)
430 this->input_file()->file().unlock(t
);
433 // Return whether the underlying file is locked.
436 { return this->input_file_
!= NULL
&& this->input_file_
->file().is_locked(); }
438 // Return the token, so that the task can be queued.
442 if (this->input_file_
== NULL
)
444 return this->input_file()->file().token();
447 // Release the underlying file.
451 if (this->input_file_
!= NULL
)
452 this->input_file()->file().release();
455 // Return whether we should just read symbols from this file.
458 { return this->input_file()->just_symbols(); }
460 // Return whether this is an incremental object.
462 is_incremental() const
463 { return this->do_is_incremental(); }
465 // Return the last modified time of the file.
468 { return this->do_get_mtime(); }
470 // Get the number of sections.
473 { return this->shnum_
; }
475 // Return a view of the contents of a section. Set *PLEN to the
476 // size. CACHE is a hint as in File_read::get_view.
478 section_contents(unsigned int shndx
, section_size_type
* plen
, bool cache
);
480 // Adjust a symbol's section index as needed. SYMNDX is the index
481 // of the symbol and SHNDX is the symbol's section from
482 // get_st_shndx. This returns the section index. It sets
483 // *IS_ORDINARY to indicate whether this is a normal section index,
484 // rather than a special code between SHN_LORESERVE and
487 adjust_sym_shndx(unsigned int symndx
, unsigned int shndx
, bool* is_ordinary
)
489 if (shndx
< elfcpp::SHN_LORESERVE
)
491 else if (shndx
== elfcpp::SHN_XINDEX
)
493 if (this->xindex_
== NULL
)
494 this->xindex_
= this->do_initialize_xindex();
495 shndx
= this->xindex_
->sym_xindex_to_shndx(this, symndx
);
499 *is_ordinary
= false;
503 // Return the size of a section given a section index.
505 section_size(unsigned int shndx
)
506 { return this->do_section_size(shndx
); }
508 // Return the name of a section given a section index.
510 section_name(unsigned int shndx
)
511 { return this->do_section_name(shndx
); }
513 // Return the section flags given a section index.
515 section_flags(unsigned int shndx
)
516 { return this->do_section_flags(shndx
); }
518 // Return the section entsize given a section index.
520 section_entsize(unsigned int shndx
)
521 { return this->do_section_entsize(shndx
); }
523 // Return the section address given a section index.
525 section_address(unsigned int shndx
)
526 { return this->do_section_address(shndx
); }
528 // Return the section type given a section index.
530 section_type(unsigned int shndx
)
531 { return this->do_section_type(shndx
); }
533 // Return the section link field given a section index.
535 section_link(unsigned int shndx
)
536 { return this->do_section_link(shndx
); }
538 // Return the section info field given a section index.
540 section_info(unsigned int shndx
)
541 { return this->do_section_info(shndx
); }
543 // Return the required section alignment given a section index.
545 section_addralign(unsigned int shndx
)
546 { return this->do_section_addralign(shndx
); }
548 // Return the output section given a section index.
550 output_section(unsigned int shndx
) const
551 { return this->do_output_section(shndx
); }
553 // Given a section index, return the offset in the Output_section.
554 // The return value will be -1U if the section is specially mapped,
555 // such as a merge section.
557 output_section_offset(unsigned int shndx
) const
558 { return this->do_output_section_offset(shndx
); }
560 // Read the symbol information.
562 read_symbols(Read_symbols_data
* sd
)
563 { return this->do_read_symbols(sd
); }
565 // Pass sections which should be included in the link to the Layout
566 // object, and record where the sections go in the output file.
568 layout(Symbol_table
* symtab
, Layout
* layout
, Read_symbols_data
* sd
)
569 { this->do_layout(symtab
, layout
, sd
); }
571 // Add symbol information to the global symbol table.
573 add_symbols(Symbol_table
* symtab
, Read_symbols_data
* sd
, Layout
*layout
)
574 { this->do_add_symbols(symtab
, sd
, layout
); }
576 // Add symbol information to the global symbol table.
577 Archive::Should_include
578 should_include_member(Symbol_table
* symtab
, Layout
* layout
,
579 Read_symbols_data
* sd
, std::string
* why
)
580 { return this->do_should_include_member(symtab
, layout
, sd
, why
); }
582 // Iterate over global symbols, calling a visitor class V for each.
584 for_all_global_symbols(Read_symbols_data
* sd
,
585 Library_base::Symbol_visitor_base
* v
)
586 { return this->do_for_all_global_symbols(sd
, v
); }
588 // Iterate over local symbols, calling a visitor class V for each GOT offset
589 // associated with a local symbol.
591 for_all_local_got_entries(Got_offset_list::Visitor
* v
) const
592 { this->do_for_all_local_got_entries(v
); }
594 // Functions and types for the elfcpp::Elf_file interface. This
595 // permit us to use Object as the File template parameter for
598 // The View class is returned by view. It must support a single
599 // method, data(). This is trivial, because get_view does what we
604 View(const unsigned char* p
)
613 const unsigned char* p_
;
618 view(off_t file_offset
, section_size_type data_size
)
619 { return View(this->get_view(file_offset
, data_size
, true, true)); }
623 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
625 // A location in the file.
631 Location(off_t fo
, section_size_type ds
)
632 : file_offset(fo
), data_size(ds
)
636 // Get a View given a Location.
637 View
view(Location loc
)
638 { return View(this->get_view(loc
.file_offset
, loc
.data_size
, true, true)); }
640 // Get a view into the underlying file.
642 get_view(off_t start
, section_size_type size
, bool aligned
, bool cache
)
644 return this->input_file()->file().get_view(this->offset_
, start
, size
,
648 // Get a lasting view into the underlying file.
650 get_lasting_view(off_t start
, section_size_type size
, bool aligned
,
653 return this->input_file()->file().get_lasting_view(this->offset_
, start
,
654 size
, aligned
, cache
);
657 // Read data from the underlying file.
659 read(off_t start
, section_size_type size
, void* p
)
660 { this->input_file()->file().read(start
+ this->offset_
, size
, p
); }
662 // Read multiple data from the underlying file.
664 read_multiple(const File_read::Read_multiple
& rm
)
665 { this->input_file()->file().read_multiple(this->offset_
, rm
); }
667 // Stop caching views in the underlying file.
669 clear_view_cache_marks()
671 if (this->input_file_
!= NULL
)
672 this->input_file_
->file().clear_view_cache_marks();
675 // Get the number of global symbols defined by this object, and the
676 // number of the symbols whose final definition came from this
679 get_global_symbol_counts(const Symbol_table
* symtab
, size_t* defined
,
681 { this->do_get_global_symbol_counts(symtab
, defined
, used
); }
683 // Get the symbols defined in this object.
685 get_global_symbols() const
686 { return this->do_get_global_symbols(); }
688 // Set flag that this object was found in a system directory.
690 set_is_in_system_directory()
691 { this->is_in_system_directory_
= true; }
693 // Return whether this object was found in a system directory.
695 is_in_system_directory() const
696 { return this->is_in_system_directory_
; }
698 // Set flag that this object was linked with --as-needed.
701 { this->as_needed_
= true; }
703 // Return whether this object was linked with --as-needed.
706 { return this->as_needed_
; }
708 // Return whether we found this object by searching a directory.
711 { return this->input_file()->will_search_for(); }
715 { return this->no_export_
; }
718 set_no_export(bool value
)
719 { this->no_export_
= value
; }
721 // Return TRUE if the section is a compressed debug section, and set
722 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
724 section_is_compressed(unsigned int shndx
,
725 section_size_type
* uncompressed_size
) const
726 { return this->do_section_is_compressed(shndx
, uncompressed_size
); }
728 // Return a view of the decompressed contents of a section. Set *PLEN
729 // to the size. Set *IS_NEW to true if the contents need to be freed
732 decompressed_section_contents(unsigned int shndx
, section_size_type
* plen
,
734 { return this->do_decompressed_section_contents(shndx
, plen
, is_cached
); }
736 // Discard any buffers of decompressed sections. This is done
737 // at the end of the Add_symbols task.
739 discard_decompressed_sections()
740 { this->do_discard_decompressed_sections(); }
742 // Return the index of the first incremental relocation for symbol SYMNDX.
744 get_incremental_reloc_base(unsigned int symndx
) const
745 { return this->do_get_incremental_reloc_base(symndx
); }
747 // Return the number of incremental relocations for symbol SYMNDX.
749 get_incremental_reloc_count(unsigned int symndx
) const
750 { return this->do_get_incremental_reloc_count(symndx
); }
753 // Returns NULL for Objects that are not dynamic objects. This method
754 // is overridden in the Dynobj class.
759 // Returns NULL for Objects that are not plugin objects. This method
760 // is overridden in the Pluginobj class.
765 // Return TRUE if this is an incremental (unchanged) input file.
766 // We return FALSE by default; the incremental object classes
767 // override this method.
769 do_is_incremental() const
772 // Return the last modified time of the file. This method may be
773 // overridden for subclasses that don't use an actual file (e.g.,
774 // Incremental objects).
777 { return this->input_file()->file().get_mtime(); }
779 // Read the symbols--implemented by child class.
781 do_read_symbols(Read_symbols_data
*) = 0;
783 // Lay out sections--implemented by child class.
785 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*) = 0;
787 // Add symbol information to the global symbol table--implemented by
790 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*) = 0;
792 virtual Archive::Should_include
793 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
794 std::string
* why
) = 0;
796 // Iterate over global symbols, calling a visitor class V for each.
798 do_for_all_global_symbols(Read_symbols_data
* sd
,
799 Library_base::Symbol_visitor_base
* v
) = 0;
801 // Iterate over local symbols, calling a visitor class V for each GOT offset
802 // associated with a local symbol.
804 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const = 0;
806 // Return the location of the contents of a section. Implemented by
808 virtual const unsigned char*
809 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
812 // Get the size of a section--implemented by child class.
814 do_section_size(unsigned int shndx
) = 0;
816 // Get the name of a section--implemented by child class.
818 do_section_name(unsigned int shndx
) = 0;
820 // Get section flags--implemented by child class.
822 do_section_flags(unsigned int shndx
) = 0;
824 // Get section entsize--implemented by child class.
826 do_section_entsize(unsigned int shndx
) = 0;
828 // Get section address--implemented by child class.
830 do_section_address(unsigned int shndx
) = 0;
832 // Get section type--implemented by child class.
834 do_section_type(unsigned int shndx
) = 0;
836 // Get section link field--implemented by child class.
838 do_section_link(unsigned int shndx
) = 0;
840 // Get section info field--implemented by child class.
842 do_section_info(unsigned int shndx
) = 0;
844 // Get section alignment--implemented by child class.
846 do_section_addralign(unsigned int shndx
) = 0;
848 // Return the output section given a section index--implemented
850 virtual Output_section
*
851 do_output_section(unsigned int) const
852 { gold_unreachable(); }
854 // Get the offset of a section--implemented by child class.
856 do_output_section_offset(unsigned int) const
857 { gold_unreachable(); }
859 // Return the Xindex structure to use.
861 do_initialize_xindex() = 0;
863 // Implement get_global_symbol_counts--implemented by child class.
865 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const = 0;
867 virtual const Symbols
*
868 do_get_global_symbols() const = 0;
870 // Set the number of sections.
873 { this->shnum_
= shnum
; }
875 // Functions used by both Sized_relobj_file and Sized_dynobj.
877 // Read the section data into a Read_symbols_data object.
878 template<int size
, bool big_endian
>
880 read_section_data(elfcpp::Elf_file
<size
, big_endian
, Object
>*,
883 // Let the child class initialize the xindex object directly.
885 set_xindex(Xindex
* xindex
)
887 gold_assert(this->xindex_
== NULL
);
888 this->xindex_
= xindex
;
891 // If NAME is the name of a special .gnu.warning section, arrange
892 // for the warning to be issued. SHNDX is the section index.
893 // Return whether it is a warning section.
895 handle_gnu_warning_section(const char* name
, unsigned int shndx
,
898 // If NAME is the name of the special section which indicates that
899 // this object was compiled with -fsplit-stack, mark it accordingly,
900 // and return true. Otherwise return false.
902 handle_split_stack_section(const char* name
);
904 // Return TRUE if the section is a compressed debug section, and set
905 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
907 do_section_is_compressed(unsigned int, section_size_type
*) const
910 // Return a view of the decompressed contents of a section. Set *PLEN
911 // to the size. This default implementation simply returns the
912 // raw section contents and sets *IS_NEW to false to indicate
913 // that the contents do not need to be freed by the caller.
914 // This function must be overridden for any types of object files
915 // that might contain compressed sections.
916 virtual const unsigned char*
917 do_decompressed_section_contents(unsigned int shndx
,
918 section_size_type
* plen
,
922 return this->do_section_contents(shndx
, plen
, false);
925 // Discard any buffers of decompressed sections. This is done
926 // at the end of the Add_symbols task.
928 do_discard_decompressed_sections()
931 // Return the index of the first incremental relocation for symbol SYMNDX--
932 // implemented by child class.
934 do_get_incremental_reloc_base(unsigned int) const
935 { gold_unreachable(); }
937 // Return the number of incremental relocations for symbol SYMNDX--
938 // implemented by child class.
940 do_get_incremental_reloc_count(unsigned int) const
941 { gold_unreachable(); }
944 // This class may not be copied.
945 Object(const Object
&);
946 Object
& operator=(const Object
&);
948 // Name of object as printed to user.
950 // For reading the file.
951 Input_file
* input_file_
;
952 // Offset within the file--0 for an object file, non-0 for an
955 // Number of input sections.
957 // Whether this is a dynamic object.
958 bool is_dynamic_
: 1;
959 // Whether this object is needed. This is only set for dynamic
960 // objects, and means that the object defined a symbol which was
961 // used by a reference from a regular object.
963 // Whether this object was compiled with -fsplit-stack.
964 bool uses_split_stack_
: 1;
965 // Whether this object contains any functions compiled with the
966 // no_split_stack attribute.
967 bool has_no_split_stack_
: 1;
968 // True if exclude this object from automatic symbol export.
969 // This is used only for archive objects.
971 // True if the object was found in a system directory.
972 bool is_in_system_directory_
: 1;
973 // True if the object was linked with --as-needed.
975 // Many sections for objects with more than SHN_LORESERVE sections.
979 // A regular object (ET_REL). This is an abstract base class itself.
980 // The implementation is the template class Sized_relobj_file.
982 class Relobj
: public Object
985 Relobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
986 : Object(name
, input_file
, false, offset
),
988 map_to_relocatable_relocs_(NULL
),
989 object_merge_map_(NULL
),
990 relocs_must_follow_section_writes_(false),
998 // During garbage collection, the Read_symbols_data pass for
999 // each object is stored as layout needs to be done after
1000 // reloc processing.
1003 { return this->sd_
; }
1005 // Decides which section names have to be included in the worklist
1008 is_section_name_included(const char* name
);
1011 copy_symbols_data(Symbols_data
* gc_sd
, Read_symbols_data
* sd
,
1012 unsigned int section_header_size
);
1015 set_symbols_data(Symbols_data
* sd
)
1018 // During garbage collection, the Read_relocs pass for all objects
1019 // is done before scanning the relocs. In that case, this->rd_ is
1020 // used to store the information from Read_relocs for each object.
1021 // This data is also used to compute the list of relevant sections.
1024 { return this->rd_
; }
1027 set_relocs_data(Read_relocs_data
* rd
)
1031 is_output_section_offset_invalid(unsigned int shndx
) const = 0;
1035 read_relocs(Read_relocs_data
* rd
)
1036 { return this->do_read_relocs(rd
); }
1038 // Process the relocs, during garbage collection only.
1040 gc_process_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1041 { return this->do_gc_process_relocs(symtab
, layout
, rd
); }
1043 // Scan the relocs and adjust the symbol table.
1045 scan_relocs(Symbol_table
* symtab
, Layout
* layout
, Read_relocs_data
* rd
)
1046 { return this->do_scan_relocs(symtab
, layout
, rd
); }
1048 // Return the value of the local symbol whose index is SYMNDX, plus
1049 // ADDEND. ADDEND is passed in so that we can correctly handle the
1050 // section symbol for a merge section.
1052 local_symbol_value(unsigned int symndx
, uint64_t addend
) const
1053 { return this->do_local_symbol_value(symndx
, addend
); }
1055 // Return the PLT offset for a local symbol. It is an error to call
1056 // this if it doesn't have one.
1058 local_plt_offset(unsigned int symndx
) const
1059 { return this->do_local_plt_offset(symndx
); }
1061 // Return whether the local symbol SYMNDX has a GOT offset of type
1064 local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1065 { return this->do_local_has_got_offset(symndx
, got_type
); }
1067 // Return the GOT offset of type GOT_TYPE of the local symbol
1068 // SYMNDX. It is an error to call this if the symbol does not have
1069 // a GOT offset of the specified type.
1071 local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1072 { return this->do_local_got_offset(symndx
, got_type
); }
1074 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1077 set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1078 unsigned int got_offset
)
1079 { this->do_set_local_got_offset(symndx
, got_type
, got_offset
); }
1081 // The number of local symbols in the input symbol table.
1082 virtual unsigned int
1083 local_symbol_count() const
1084 { return this->do_local_symbol_count(); }
1086 // The number of local symbols in the output symbol table.
1087 virtual unsigned int
1088 output_local_symbol_count() const
1089 { return this->do_output_local_symbol_count(); }
1091 // The file offset for local symbols in the output symbol table.
1093 local_symbol_offset() const
1094 { return this->do_local_symbol_offset(); }
1096 // Initial local symbol processing: count the number of local symbols
1097 // in the output symbol table and dynamic symbol table; add local symbol
1098 // names to *POOL and *DYNPOOL.
1100 count_local_symbols(Stringpool_template
<char>* pool
,
1101 Stringpool_template
<char>* dynpool
)
1102 { return this->do_count_local_symbols(pool
, dynpool
); }
1104 // Set the values of the local symbols, set the output symbol table
1105 // indexes for the local variables, and set the offset where local
1106 // symbol information will be stored. Returns the new local symbol index.
1108 finalize_local_symbols(unsigned int index
, off_t off
, Symbol_table
* symtab
)
1109 { return this->do_finalize_local_symbols(index
, off
, symtab
); }
1111 // Set the output dynamic symbol table indexes for the local variables.
1113 set_local_dynsym_indexes(unsigned int index
)
1114 { return this->do_set_local_dynsym_indexes(index
); }
1116 // Set the offset where local dynamic symbol information will be stored.
1118 set_local_dynsym_offset(off_t off
)
1119 { return this->do_set_local_dynsym_offset(off
); }
1121 // Record a dynamic relocation against an input section from this object.
1123 add_dyn_reloc(unsigned int index
)
1125 if (this->dyn_reloc_count_
== 0)
1126 this->first_dyn_reloc_
= index
;
1127 ++this->dyn_reloc_count_
;
1130 // Return the index of the first dynamic relocation.
1132 first_dyn_reloc() const
1133 { return this->first_dyn_reloc_
; }
1135 // Return the count of dynamic relocations.
1137 dyn_reloc_count() const
1138 { return this->dyn_reloc_count_
; }
1140 // Relocate the input sections and write out the local symbols.
1142 relocate(const Symbol_table
* symtab
, const Layout
* layout
, Output_file
* of
)
1143 { return this->do_relocate(symtab
, layout
, of
); }
1145 // Return whether an input section is being included in the link.
1147 is_section_included(unsigned int shndx
) const
1149 gold_assert(shndx
< this->output_sections_
.size());
1150 return this->output_sections_
[shndx
] != NULL
;
1153 // The the output section of the input section with index SHNDX.
1154 // This is only used currently to remove a section from the link in
1157 set_output_section(unsigned int shndx
, Output_section
* os
)
1159 gold_assert(shndx
< this->output_sections_
.size());
1160 this->output_sections_
[shndx
] = os
;
1163 // Set the offset of an input section within its output section.
1165 set_section_offset(unsigned int shndx
, uint64_t off
)
1166 { this->do_set_section_offset(shndx
, off
); }
1168 // Return true if we need to wait for output sections to be written
1169 // before we can apply relocations. This is true if the object has
1170 // any relocations for sections which require special handling, such
1171 // as the exception frame section.
1173 relocs_must_follow_section_writes() const
1174 { return this->relocs_must_follow_section_writes_
; }
1176 // Return the object merge map.
1179 { return this->object_merge_map_
; }
1181 // Set the object merge map.
1183 set_merge_map(Object_merge_map
* object_merge_map
)
1185 gold_assert(this->object_merge_map_
== NULL
);
1186 this->object_merge_map_
= object_merge_map
;
1189 // Record the relocatable reloc info for an input reloc section.
1191 set_relocatable_relocs(unsigned int reloc_shndx
, Relocatable_relocs
* rr
)
1193 gold_assert(reloc_shndx
< this->shnum());
1194 (*this->map_to_relocatable_relocs_
)[reloc_shndx
] = rr
;
1197 // Get the relocatable reloc info for an input reloc section.
1199 relocatable_relocs(unsigned int reloc_shndx
)
1201 gold_assert(reloc_shndx
< this->shnum());
1202 return (*this->map_to_relocatable_relocs_
)[reloc_shndx
];
1205 // Layout sections whose layout was deferred while waiting for
1206 // input files from a plugin.
1208 layout_deferred_sections(Layout
* layout
)
1209 { this->do_layout_deferred_sections(layout
); }
1211 // Return the index of the first incremental relocation for symbol SYMNDX.
1212 virtual unsigned int
1213 do_get_incremental_reloc_base(unsigned int symndx
) const
1214 { return this->reloc_bases_
[symndx
]; }
1216 // Return the number of incremental relocations for symbol SYMNDX.
1217 virtual unsigned int
1218 do_get_incremental_reloc_count(unsigned int symndx
) const
1219 { return this->reloc_counts_
[symndx
]; }
1222 // The output section to be used for each input section, indexed by
1223 // the input section number. The output section is NULL if the
1224 // input section is to be discarded.
1225 typedef std::vector
<Output_section
*> Output_sections
;
1227 // Read the relocs--implemented by child class.
1229 do_read_relocs(Read_relocs_data
*) = 0;
1231 // Process the relocs--implemented by child class.
1233 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1235 // Scan the relocs--implemented by child class.
1237 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*) = 0;
1239 // Return the value of a local symbol.
1241 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const = 0;
1243 // Return the PLT offset of a local symbol.
1244 virtual unsigned int
1245 do_local_plt_offset(unsigned int symndx
) const = 0;
1247 // Return whether a local symbol has a GOT offset of a given type.
1249 do_local_has_got_offset(unsigned int symndx
,
1250 unsigned int got_type
) const = 0;
1252 // Return the GOT offset of a given type of a local symbol.
1253 virtual unsigned int
1254 do_local_got_offset(unsigned int symndx
, unsigned int got_type
) const = 0;
1256 // Set the GOT offset with a given type for a local symbol.
1258 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1259 unsigned int got_offset
) = 0;
1261 // Return the number of local symbols--implemented by child class.
1262 virtual unsigned int
1263 do_local_symbol_count() const = 0;
1265 // Return the number of output local symbols--implemented by child class.
1266 virtual unsigned int
1267 do_output_local_symbol_count() const = 0;
1269 // Return the file offset for local symbols--implemented by child class.
1271 do_local_symbol_offset() const = 0;
1273 // Count local symbols--implemented by child class.
1275 do_count_local_symbols(Stringpool_template
<char>*,
1276 Stringpool_template
<char>*) = 0;
1278 // Finalize the local symbols. Set the output symbol table indexes
1279 // for the local variables, and set the offset where local symbol
1280 // information will be stored.
1281 virtual unsigned int
1282 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*) = 0;
1284 // Set the output dynamic symbol table indexes for the local variables.
1285 virtual unsigned int
1286 do_set_local_dynsym_indexes(unsigned int) = 0;
1288 // Set the offset where local dynamic symbol information will be stored.
1289 virtual unsigned int
1290 do_set_local_dynsym_offset(off_t
) = 0;
1292 // Relocate the input sections and write out the local
1293 // symbols--implemented by child class.
1295 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
) = 0;
1297 // Set the offset of a section--implemented by child class.
1299 do_set_section_offset(unsigned int shndx
, uint64_t off
) = 0;
1301 // Layout sections whose layout was deferred while waiting for
1302 // input files from a plugin--implemented by child class.
1304 do_layout_deferred_sections(Layout
*) = 0;
1306 // Given a section index, return the corresponding Output_section.
1307 // The return value will be NULL if the section is not included in
1310 do_output_section(unsigned int shndx
) const
1312 gold_assert(shndx
< this->output_sections_
.size());
1313 return this->output_sections_
[shndx
];
1316 // Return the vector mapping input sections to output sections.
1319 { return this->output_sections_
; }
1321 const Output_sections
&
1322 output_sections() const
1323 { return this->output_sections_
; }
1325 // Set the size of the relocatable relocs array.
1327 size_relocatable_relocs()
1329 this->map_to_relocatable_relocs_
=
1330 new std::vector
<Relocatable_relocs
*>(this->shnum());
1333 // Record that we must wait for the output sections to be written
1334 // before applying relocations.
1336 set_relocs_must_follow_section_writes()
1337 { this->relocs_must_follow_section_writes_
= true; }
1339 // Allocate the array for counting incremental relocations.
1341 allocate_incremental_reloc_counts()
1343 unsigned int nsyms
= this->do_get_global_symbols()->size();
1344 this->reloc_counts_
= new unsigned int[nsyms
];
1345 gold_assert(this->reloc_counts_
!= NULL
);
1346 memset(this->reloc_counts_
, 0, nsyms
* sizeof(unsigned int));
1349 // Record a relocation in this object referencing global symbol SYMNDX.
1350 // Used for tracking incremental link information.
1352 count_incremental_reloc(unsigned int symndx
)
1354 unsigned int nsyms
= this->do_get_global_symbols()->size();
1355 gold_assert(symndx
< nsyms
);
1356 gold_assert(this->reloc_counts_
!= NULL
);
1357 ++this->reloc_counts_
[symndx
];
1360 // Finalize the incremental relocation information.
1362 finalize_incremental_relocs(Layout
* layout
, bool clear_counts
);
1364 // Return the index of the next relocation to be written for global symbol
1365 // SYMNDX. Only valid after finalize_incremental_relocs() has been called.
1367 next_incremental_reloc_index(unsigned int symndx
)
1369 unsigned int nsyms
= this->do_get_global_symbols()->size();
1371 gold_assert(this->reloc_counts_
!= NULL
);
1372 gold_assert(this->reloc_bases_
!= NULL
);
1373 gold_assert(symndx
< nsyms
);
1375 unsigned int counter
= this->reloc_counts_
[symndx
]++;
1376 return this->reloc_bases_
[symndx
] + counter
;
1380 // Mapping from input sections to output section.
1381 Output_sections output_sections_
;
1382 // Mapping from input section index to the information recorded for
1383 // the relocations. This is only used for a relocatable link.
1384 std::vector
<Relocatable_relocs
*>* map_to_relocatable_relocs_
;
1385 // Mappings for merge sections. This is managed by the code in the
1387 Object_merge_map
* object_merge_map_
;
1388 // Whether we need to wait for output sections to be written before
1389 // we can apply relocations.
1390 bool relocs_must_follow_section_writes_
;
1391 // Used to store the relocs data computed by the Read_relocs pass.
1392 // Used during garbage collection of unused sections.
1393 Read_relocs_data
* rd_
;
1394 // Used to store the symbols data computed by the Read_symbols pass.
1395 // Again used during garbage collection when laying out referenced
1397 gold::Symbols_data
* sd_
;
1398 // Per-symbol counts of relocations, for incremental links.
1399 unsigned int* reloc_counts_
;
1400 // Per-symbol base indexes of relocations, for incremental links.
1401 unsigned int* reloc_bases_
;
1402 // Index of the first dynamic relocation for this object.
1403 unsigned int first_dyn_reloc_
;
1404 // Count of dynamic relocations for this object.
1405 unsigned int dyn_reloc_count_
;
1408 // This class is used to handle relocations against a section symbol
1409 // in an SHF_MERGE section. For such a symbol, we need to know the
1410 // addend of the relocation before we can determine the final value.
1411 // The addend gives us the location in the input section, and we can
1412 // determine how it is mapped to the output section. For a
1413 // non-section symbol, we apply the addend to the final value of the
1414 // symbol; that is done in finalize_local_symbols, and does not use
1418 class Merged_symbol_value
1421 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1423 // We use a hash table to map offsets in the input section to output
1425 typedef Unordered_map
<section_offset_type
, Value
> Output_addresses
;
1427 Merged_symbol_value(Value input_value
, Value output_start_address
)
1428 : input_value_(input_value
), output_start_address_(output_start_address
),
1432 // Initialize the hash table.
1434 initialize_input_to_output_map(const Relobj
*, unsigned int input_shndx
);
1436 // Release the hash table to save space.
1438 free_input_to_output_map()
1439 { this->output_addresses_
.clear(); }
1441 // Get the output value corresponding to an addend. The object and
1442 // input section index are passed in because the caller will have
1443 // them; otherwise we could store them here.
1445 value(const Relobj
* object
, unsigned int input_shndx
, Value addend
) const
1447 // This is a relocation against a section symbol. ADDEND is the
1448 // offset in the section. The result should be the start of some
1449 // merge area. If the object file wants something else, it should
1450 // use a regular symbol rather than a section symbol.
1451 // Unfortunately, PR 6658 shows a case in which the object file
1452 // refers to the section symbol, but uses a negative ADDEND to
1453 // compensate for a PC relative reloc. We can't handle the
1454 // general case. However, we can handle the special case of a
1455 // negative addend, by assuming that it refers to the start of the
1456 // section. Of course, that means that we have to guess when
1457 // ADDEND is negative. It is normal to see a 32-bit value here
1458 // even when the template parameter size is 64, as 64-bit object
1459 // file formats have 32-bit relocations. We know this is a merge
1460 // section, so we know it has to fit into memory. So we assume
1461 // that we won't see a value larger than a large 32-bit unsigned
1462 // value. This will break objects with very very large merge
1463 // sections; they probably break in other ways anyhow.
1464 Value input_offset
= this->input_value_
;
1465 if (addend
< 0xffffff00)
1467 input_offset
+= addend
;
1470 typename
Output_addresses::const_iterator p
=
1471 this->output_addresses_
.find(input_offset
);
1472 if (p
!= this->output_addresses_
.end())
1473 return p
->second
+ addend
;
1475 return (this->value_from_output_section(object
, input_shndx
, input_offset
)
1480 // Get the output value for an input offset if we couldn't find it
1481 // in the hash table.
1483 value_from_output_section(const Relobj
*, unsigned int input_shndx
,
1484 Value input_offset
) const;
1486 // The value of the section symbol in the input file. This is
1487 // normally zero, but could in principle be something else.
1489 // The start address of this merged section in the output file.
1490 Value output_start_address_
;
1491 // A hash table which maps offsets in the input section to output
1492 // addresses. This only maps specific offsets, not all offsets.
1493 Output_addresses output_addresses_
;
1496 // This POD class is holds the value of a symbol. This is used for
1497 // local symbols, and for all symbols during relocation processing.
1498 // For special sections, such as SHF_MERGE sections, this calls a
1499 // function to get the final symbol value.
1505 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value
;
1508 : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
1509 is_ordinary_shndx_(false), is_section_symbol_(false),
1510 is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true)
1511 { this->u_
.value
= 0; }
1515 if (!this->has_output_value_
)
1516 delete this->u_
.merged_symbol_value
;
1519 // Get the value of this symbol. OBJECT is the object in which this
1520 // symbol is defined, and ADDEND is an addend to add to the value.
1521 template<bool big_endian
>
1523 value(const Sized_relobj_file
<size
, big_endian
>* object
, Value addend
) const
1525 if (this->has_output_value_
)
1526 return this->u_
.value
+ addend
;
1529 gold_assert(this->is_ordinary_shndx_
);
1530 return this->u_
.merged_symbol_value
->value(object
, this->input_shndx_
,
1535 // Set the value of this symbol in the output symbol table.
1537 set_output_value(Value value
)
1538 { this->u_
.value
= value
; }
1540 // For a section symbol in a merged section, we need more
1543 set_merged_symbol_value(Merged_symbol_value
<size
>* msv
)
1545 gold_assert(this->is_section_symbol_
);
1546 this->has_output_value_
= false;
1547 this->u_
.merged_symbol_value
= msv
;
1550 // Initialize the input to output map for a section symbol in a
1551 // merged section. We also initialize the value of a non-section
1552 // symbol in a merged section.
1554 initialize_input_to_output_map(const Relobj
* object
)
1556 if (!this->has_output_value_
)
1558 gold_assert(this->is_section_symbol_
&& this->is_ordinary_shndx_
);
1559 Merged_symbol_value
<size
>* msv
= this->u_
.merged_symbol_value
;
1560 msv
->initialize_input_to_output_map(object
, this->input_shndx_
);
1564 // Free the input to output map for a section symbol in a merged
1567 free_input_to_output_map()
1569 if (!this->has_output_value_
)
1570 this->u_
.merged_symbol_value
->free_input_to_output_map();
1573 // Set the value of the symbol from the input file. This is only
1574 // called by count_local_symbols, to communicate the value to
1575 // finalize_local_symbols.
1577 set_input_value(Value value
)
1578 { this->u_
.value
= value
; }
1580 // Return the input value. This is only called by
1581 // finalize_local_symbols and (in special cases) relocate_section.
1584 { return this->u_
.value
; }
1586 // Return whether we have set the index in the output symbol table
1589 is_output_symtab_index_set() const
1591 return (this->output_symtab_index_
!= 0
1592 && this->output_symtab_index_
!= -2U);
1595 // Return whether this symbol may be discarded from the normal
1598 may_be_discarded_from_output_symtab() const
1600 gold_assert(!this->is_output_symtab_index_set());
1601 return this->output_symtab_index_
!= -2U;
1604 // Return whether this symbol has an entry in the output symbol
1607 has_output_symtab_entry() const
1609 gold_assert(this->is_output_symtab_index_set());
1610 return this->output_symtab_index_
!= -1U;
1613 // Return the index in the output symbol table.
1615 output_symtab_index() const
1617 gold_assert(this->is_output_symtab_index_set()
1618 && this->output_symtab_index_
!= -1U);
1619 return this->output_symtab_index_
;
1622 // Set the index in the output symbol table.
1624 set_output_symtab_index(unsigned int i
)
1626 gold_assert(!this->is_output_symtab_index_set());
1627 gold_assert(i
!= 0 && i
!= -1U && i
!= -2U);
1628 this->output_symtab_index_
= i
;
1631 // Record that this symbol should not go into the output symbol
1634 set_no_output_symtab_entry()
1636 gold_assert(this->output_symtab_index_
== 0);
1637 this->output_symtab_index_
= -1U;
1640 // Record that this symbol must go into the output symbol table,
1641 // because it there is a relocation that uses it.
1643 set_must_have_output_symtab_entry()
1645 gold_assert(!this->is_output_symtab_index_set());
1646 this->output_symtab_index_
= -2U;
1649 // Set the index in the output dynamic symbol table.
1651 set_needs_output_dynsym_entry()
1653 gold_assert(!this->is_section_symbol());
1654 this->output_dynsym_index_
= 0;
1657 // Return whether this symbol should go into the dynamic symbol
1660 needs_output_dynsym_entry() const
1662 return this->output_dynsym_index_
!= -1U;
1665 // Return whether this symbol has an entry in the dynamic symbol
1668 has_output_dynsym_entry() const
1670 gold_assert(this->output_dynsym_index_
!= 0);
1671 return this->output_dynsym_index_
!= -1U;
1674 // Record that this symbol should go into the dynamic symbol table.
1676 set_output_dynsym_index(unsigned int i
)
1678 gold_assert(this->output_dynsym_index_
== 0);
1679 gold_assert(i
!= 0 && i
!= -1U);
1680 this->output_dynsym_index_
= i
;
1683 // Return the index in the output dynamic symbol table.
1685 output_dynsym_index() const
1687 gold_assert(this->output_dynsym_index_
!= 0
1688 && this->output_dynsym_index_
!= -1U);
1689 return this->output_dynsym_index_
;
1692 // Set the index of the input section in the input file.
1694 set_input_shndx(unsigned int i
, bool is_ordinary
)
1696 this->input_shndx_
= i
;
1697 // input_shndx_ field is a bitfield, so make sure that the value
1699 gold_assert(this->input_shndx_
== i
);
1700 this->is_ordinary_shndx_
= is_ordinary
;
1703 // Return the index of the input section in the input file.
1705 input_shndx(bool* is_ordinary
) const
1707 *is_ordinary
= this->is_ordinary_shndx_
;
1708 return this->input_shndx_
;
1711 // Whether this is a section symbol.
1713 is_section_symbol() const
1714 { return this->is_section_symbol_
; }
1716 // Record that this is a section symbol.
1718 set_is_section_symbol()
1720 gold_assert(!this->needs_output_dynsym_entry());
1721 this->is_section_symbol_
= true;
1724 // Record that this is a TLS symbol.
1727 { this->is_tls_symbol_
= true; }
1729 // Return true if this is a TLS symbol.
1731 is_tls_symbol() const
1732 { return this->is_tls_symbol_
; }
1734 // Record that this is an IFUNC symbol.
1736 set_is_ifunc_symbol()
1737 { this->is_ifunc_symbol_
= true; }
1739 // Return true if this is an IFUNC symbol.
1741 is_ifunc_symbol() const
1742 { return this->is_ifunc_symbol_
; }
1744 // Return true if this has output value.
1746 has_output_value() const
1747 { return this->has_output_value_
; }
1750 // The index of this local symbol in the output symbol table. This
1751 // will be 0 if no value has been assigned yet, and the symbol may
1752 // be omitted. This will be -1U if the symbol should not go into
1753 // the symbol table. This will be -2U if the symbol must go into
1754 // the symbol table, but no index has been assigned yet.
1755 unsigned int output_symtab_index_
;
1756 // The index of this local symbol in the dynamic symbol table. This
1757 // will be -1U if the symbol should not go into the symbol table.
1758 unsigned int output_dynsym_index_
;
1759 // The section index in the input file in which this symbol is
1761 unsigned int input_shndx_
: 27;
1762 // Whether the section index is an ordinary index, not a special
1764 bool is_ordinary_shndx_
: 1;
1765 // Whether this is a STT_SECTION symbol.
1766 bool is_section_symbol_
: 1;
1767 // Whether this is a STT_TLS symbol.
1768 bool is_tls_symbol_
: 1;
1769 // Whether this is a STT_GNU_IFUNC symbol.
1770 bool is_ifunc_symbol_
: 1;
1771 // Whether this symbol has a value for the output file. This is
1772 // normally set to true during Layout::finalize, by
1773 // finalize_local_symbols. It will be false for a section symbol in
1774 // a merge section, as for such symbols we can not determine the
1775 // value to use in a relocation until we see the addend.
1776 bool has_output_value_
: 1;
1779 // This is used if has_output_value_ is true. Between
1780 // count_local_symbols and finalize_local_symbols, this is the
1781 // value in the input file. After finalize_local_symbols, it is
1782 // the value in the output file.
1784 // This is used if has_output_value_ is false. It points to the
1785 // information we need to get the value for a merge section.
1786 Merged_symbol_value
<size
>* merged_symbol_value
;
1790 // This type is used to modify relocations for -fsplit-stack. It is
1791 // indexed by relocation index, and means that the relocation at that
1792 // index should use the symbol from the vector, rather than the one
1793 // indicated by the relocation.
1795 class Reloc_symbol_changes
1798 Reloc_symbol_changes(size_t count
)
1803 set(size_t i
, Symbol
* sym
)
1804 { this->vec_
[i
] = sym
; }
1807 operator[](size_t i
) const
1808 { return this->vec_
[i
]; }
1811 std::vector
<Symbol
*> vec_
;
1814 // Type for mapping section index to uncompressed size and contents.
1816 struct Compressed_section_info
1818 section_size_type size
;
1819 const unsigned char* contents
;
1821 typedef std::map
<unsigned int, Compressed_section_info
> Compressed_section_map
;
1823 // Abstract base class for a regular object file, either a real object file
1824 // or an incremental (unchanged) object. This is size and endian specific.
1826 template<int size
, bool big_endian
>
1827 class Sized_relobj
: public Relobj
1830 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1831 typedef Relobj::Symbols Symbols
;
1833 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1835 Sized_relobj(const std::string
& name
, Input_file
* input_file
)
1836 : Relobj(name
, input_file
), local_got_offsets_(), section_offsets_()
1839 Sized_relobj(const std::string
& name
, Input_file
* input_file
,
1841 : Relobj(name
, input_file
, offset
), local_got_offsets_(), section_offsets_()
1847 // If this is a regular object, return a pointer to the Sized_relobj_file
1848 // object. Otherwise, return NULL.
1849 virtual Sized_relobj_file
<size
, big_endian
>*
1853 const virtual Sized_relobj_file
<size
, big_endian
>*
1854 sized_relobj() const
1857 // Checks if the offset of input section SHNDX within its output
1858 // section is invalid.
1860 is_output_section_offset_invalid(unsigned int shndx
) const
1861 { return this->get_output_section_offset(shndx
) == invalid_address
; }
1863 // Get the offset of input section SHNDX within its output section.
1864 // This is -1 if the input section requires a special mapping, such
1865 // as a merge section. The output section can be found in the
1866 // output_sections_ field of the parent class Relobj.
1868 get_output_section_offset(unsigned int shndx
) const
1870 gold_assert(shndx
< this->section_offsets_
.size());
1871 return this->section_offsets_
[shndx
];
1874 // Iterate over local symbols, calling a visitor class V for each GOT offset
1875 // associated with a local symbol.
1877 do_for_all_local_got_entries(Got_offset_list::Visitor
* v
) const;
1880 typedef Relobj::Output_sections Output_sections
;
1882 // Clear the local symbol information.
1885 { this->local_got_offsets_
.clear(); }
1887 // Return the vector of section offsets.
1888 std::vector
<Address
>&
1890 { return this->section_offsets_
; }
1892 // Get the offset of a section.
1894 do_output_section_offset(unsigned int shndx
) const
1896 Address off
= this->get_output_section_offset(shndx
);
1897 if (off
== invalid_address
)
1902 // Set the offset of a section.
1904 do_set_section_offset(unsigned int shndx
, uint64_t off
)
1906 gold_assert(shndx
< this->section_offsets_
.size());
1907 this->section_offsets_
[shndx
] =
1908 (off
== static_cast<uint64_t>(-1)
1910 : convert_types
<Address
, uint64_t>(off
));
1913 // Return whether the local symbol SYMNDX has a GOT offset of type
1916 do_local_has_got_offset(unsigned int symndx
, unsigned int got_type
) const
1918 Local_got_offsets::const_iterator p
=
1919 this->local_got_offsets_
.find(symndx
);
1920 return (p
!= this->local_got_offsets_
.end()
1921 && p
->second
->get_offset(got_type
) != -1U);
1924 // Return the GOT offset of type GOT_TYPE of the local symbol
1927 do_local_got_offset(unsigned int symndx
, unsigned int got_type
) const
1929 Local_got_offsets::const_iterator p
=
1930 this->local_got_offsets_
.find(symndx
);
1931 gold_assert(p
!= this->local_got_offsets_
.end());
1932 unsigned int off
= p
->second
->get_offset(got_type
);
1933 gold_assert(off
!= -1U);
1937 // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX
1940 do_set_local_got_offset(unsigned int symndx
, unsigned int got_type
,
1941 unsigned int got_offset
)
1943 Local_got_offsets::const_iterator p
=
1944 this->local_got_offsets_
.find(symndx
);
1945 if (p
!= this->local_got_offsets_
.end())
1946 p
->second
->set_offset(got_type
, got_offset
);
1949 Got_offset_list
* g
= new Got_offset_list(got_type
, got_offset
);
1950 std::pair
<Local_got_offsets::iterator
, bool> ins
=
1951 this->local_got_offsets_
.insert(std::make_pair(symndx
, g
));
1952 gold_assert(ins
.second
);
1957 // The GOT offsets of local symbols. This map also stores GOT offsets
1958 // for tp-relative offsets for TLS symbols.
1959 typedef Unordered_map
<unsigned int, Got_offset_list
*> Local_got_offsets
;
1961 // GOT offsets for local non-TLS symbols, and tp-relative offsets
1962 // for TLS symbols, indexed by symbol number.
1963 Local_got_offsets local_got_offsets_
;
1964 // For each input section, the offset of the input section in its
1965 // output section. This is INVALID_ADDRESS if the input section requires a
1967 std::vector
<Address
> section_offsets_
;
1970 // A regular object file. This is size and endian specific.
1972 template<int size
, bool big_endian
>
1973 class Sized_relobj_file
: public Sized_relobj
<size
, big_endian
>
1976 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Address
;
1977 typedef typename Sized_relobj
<size
, big_endian
>::Symbols Symbols
;
1978 typedef std::vector
<Symbol_value
<size
> > Local_values
;
1980 static const Address invalid_address
= static_cast<Address
>(0) - 1;
1982 enum Compute_final_local_value_status
1986 // An error occurred.
1988 // The local symbol has no output section.
1992 Sized_relobj_file(const std::string
& name
,
1993 Input_file
* input_file
,
1995 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
1997 ~Sized_relobj_file();
1999 // Set up the object file based on TARGET.
2002 { this->do_setup(); }
2004 // Return a pointer to the Sized_relobj_file object.
2005 Sized_relobj_file
<size
, big_endian
>*
2009 const Sized_relobj_file
<size
, big_endian
>*
2010 sized_relobj() const
2013 // Return the ELF file type.
2016 { return this->e_type_
; }
2018 // Return the number of symbols. This is only valid after
2019 // Object::add_symbols has been called.
2021 symbol_count() const
2022 { return this->local_symbol_count_
+ this->symbols_
.size(); }
2024 // If SYM is the index of a global symbol in the object file's
2025 // symbol table, return the Symbol object. Otherwise, return NULL.
2027 global_symbol(unsigned int sym
) const
2029 if (sym
>= this->local_symbol_count_
)
2031 gold_assert(sym
- this->local_symbol_count_
< this->symbols_
.size());
2032 return this->symbols_
[sym
- this->local_symbol_count_
];
2037 // Return the section index of symbol SYM. Set *VALUE to its value
2038 // in the object file. Set *IS_ORDINARY if this is an ordinary
2039 // section index, not a special code between SHN_LORESERVE and
2040 // SHN_HIRESERVE. Note that for a symbol which is not defined in
2041 // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
2042 // it will not return the final value of the symbol in the link.
2044 symbol_section_and_value(unsigned int sym
, Address
* value
, bool* is_ordinary
);
2046 // Return a pointer to the Symbol_value structure which holds the
2047 // value of a local symbol.
2048 const Symbol_value
<size
>*
2049 local_symbol(unsigned int sym
) const
2051 gold_assert(sym
< this->local_values_
.size());
2052 return &this->local_values_
[sym
];
2055 // Return the index of local symbol SYM in the ordinary symbol
2056 // table. A value of -1U means that the symbol is not being output.
2058 symtab_index(unsigned int sym
) const
2060 gold_assert(sym
< this->local_values_
.size());
2061 return this->local_values_
[sym
].output_symtab_index();
2064 // Return the index of local symbol SYM in the dynamic symbol
2065 // table. A value of -1U means that the symbol is not being output.
2067 dynsym_index(unsigned int sym
) const
2069 gold_assert(sym
< this->local_values_
.size());
2070 return this->local_values_
[sym
].output_dynsym_index();
2073 // Return the input section index of local symbol SYM.
2075 local_symbol_input_shndx(unsigned int sym
, bool* is_ordinary
) const
2077 gold_assert(sym
< this->local_values_
.size());
2078 return this->local_values_
[sym
].input_shndx(is_ordinary
);
2081 // Record that local symbol SYM must be in the output symbol table.
2083 set_must_have_output_symtab_entry(unsigned int sym
)
2085 gold_assert(sym
< this->local_values_
.size());
2086 this->local_values_
[sym
].set_must_have_output_symtab_entry();
2089 // Record that local symbol SYM needs a dynamic symbol entry.
2091 set_needs_output_dynsym_entry(unsigned int sym
)
2093 gold_assert(sym
< this->local_values_
.size());
2094 this->local_values_
[sym
].set_needs_output_dynsym_entry();
2097 // Return whether the local symbol SYMNDX has a PLT offset.
2099 local_has_plt_offset(unsigned int symndx
) const;
2101 // Set the PLT offset of the local symbol SYMNDX.
2103 set_local_plt_offset(unsigned int symndx
, unsigned int plt_offset
);
2105 // Return the name of the symbol that spans the given offset in the
2106 // specified section in this object. This is used only for error
2107 // messages and is not particularly efficient.
2109 get_symbol_location_info(unsigned int shndx
, off_t offset
,
2110 Symbol_location_info
* info
);
2112 // Look for a kept section corresponding to the given discarded section,
2113 // and return its output address. This is used only for relocations in
2114 // debugging sections.
2116 map_to_kept_section(unsigned int shndx
, bool* found
) const;
2118 // Compute final local symbol value. R_SYM is the local symbol index.
2119 // LV_IN points to a local symbol value containing the input value.
2120 // LV_OUT points to a local symbol value storing the final output value,
2121 // which must not be a merged symbol value since before calling this
2122 // method to avoid memory leak. SYMTAB points to a symbol table.
2124 // The method returns a status code at return. If the return status is
2125 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2126 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2127 // *LV_OUT is not modified.
2128 Compute_final_local_value_status
2129 compute_final_local_value(unsigned int r_sym
,
2130 const Symbol_value
<size
>* lv_in
,
2131 Symbol_value
<size
>* lv_out
,
2132 const Symbol_table
* symtab
);
2135 typedef typename Sized_relobj
<size
, big_endian
>::Output_sections
2142 // Read the symbols.
2144 do_read_symbols(Read_symbols_data
*);
2146 // Return the value of a local symbol.
2148 do_local_symbol_value(unsigned int symndx
, uint64_t addend
) const
2150 const Symbol_value
<size
>* symval
= this->local_symbol(symndx
);
2151 return symval
->value(this, addend
);
2154 // Return the PLT offset for a local symbol. It is an error to call
2155 // this if it doesn't have one.
2157 do_local_plt_offset(unsigned int symndx
) const;
2159 // Return the number of local symbols.
2161 do_local_symbol_count() const
2162 { return this->local_symbol_count_
; }
2164 // Return the number of local symbols in the output symbol table.
2166 do_output_local_symbol_count() const
2167 { return this->output_local_symbol_count_
; }
2169 // Return the number of local symbols in the output symbol table.
2171 do_local_symbol_offset() const
2172 { return this->local_symbol_offset_
; }
2174 // Lay out the input sections.
2176 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
2178 // Layout sections whose layout was deferred while waiting for
2179 // input files from a plugin.
2181 do_layout_deferred_sections(Layout
*);
2183 // Add the symbols to the symbol table.
2185 do_add_symbols(Symbol_table
*, Read_symbols_data
*, Layout
*);
2187 Archive::Should_include
2188 do_should_include_member(Symbol_table
* symtab
, Layout
*, Read_symbols_data
*,
2191 // Iterate over global symbols, calling a visitor class V for each.
2193 do_for_all_global_symbols(Read_symbols_data
* sd
,
2194 Library_base::Symbol_visitor_base
* v
);
2198 do_read_relocs(Read_relocs_data
*);
2200 // Process the relocs to find list of referenced sections. Used only
2201 // during garbage collection.
2203 do_gc_process_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2205 // Scan the relocs and adjust the symbol table.
2207 do_scan_relocs(Symbol_table
*, Layout
*, Read_relocs_data
*);
2209 // Count the local symbols.
2211 do_count_local_symbols(Stringpool_template
<char>*,
2212 Stringpool_template
<char>*);
2214 // Finalize the local symbols.
2216 do_finalize_local_symbols(unsigned int, off_t
, Symbol_table
*);
2218 // Set the offset where local dynamic symbol information will be stored.
2220 do_set_local_dynsym_indexes(unsigned int);
2222 // Set the offset where local dynamic symbol information will be stored.
2224 do_set_local_dynsym_offset(off_t
);
2226 // Relocate the input sections and write out the local symbols.
2228 do_relocate(const Symbol_table
* symtab
, const Layout
*, Output_file
* of
);
2230 // Get the size of a section.
2232 do_section_size(unsigned int shndx
)
2233 { return this->elf_file_
.section_size(shndx
); }
2235 // Get the name of a section.
2237 do_section_name(unsigned int shndx
)
2238 { return this->elf_file_
.section_name(shndx
); }
2240 // Return the location of the contents of a section.
2241 const unsigned char*
2242 do_section_contents(unsigned int shndx
, section_size_type
* plen
,
2245 Object::Location
loc(this->elf_file_
.section_contents(shndx
));
2246 *plen
= convert_to_section_size_type(loc
.data_size
);
2249 static const unsigned char empty
[1] = { '\0' };
2252 return this->get_view(loc
.file_offset
, *plen
, true, cache
);
2255 // Return section flags.
2257 do_section_flags(unsigned int shndx
);
2259 // Return section entsize.
2261 do_section_entsize(unsigned int shndx
);
2263 // Return section address.
2265 do_section_address(unsigned int shndx
)
2266 { return this->elf_file_
.section_addr(shndx
); }
2268 // Return section type.
2270 do_section_type(unsigned int shndx
)
2271 { return this->elf_file_
.section_type(shndx
); }
2273 // Return the section link field.
2275 do_section_link(unsigned int shndx
)
2276 { return this->elf_file_
.section_link(shndx
); }
2278 // Return the section info field.
2280 do_section_info(unsigned int shndx
)
2281 { return this->elf_file_
.section_info(shndx
); }
2283 // Return the section alignment.
2285 do_section_addralign(unsigned int shndx
)
2286 { return this->elf_file_
.section_addralign(shndx
); }
2288 // Return the Xindex structure to use.
2290 do_initialize_xindex();
2292 // Get symbol counts.
2294 do_get_global_symbol_counts(const Symbol_table
*, size_t*, size_t*) const;
2296 // Get the global symbols.
2298 do_get_global_symbols() const
2299 { return &this->symbols_
; }
2301 // Adjust a section index if necessary.
2303 adjust_shndx(unsigned int shndx
)
2305 if (shndx
>= elfcpp::SHN_LORESERVE
)
2306 shndx
+= this->elf_file_
.large_shndx_offset();
2310 // Initialize input to output maps for section symbols in merged
2313 initialize_input_to_output_maps();
2315 // Free the input to output maps for section symbols in merged
2318 free_input_to_output_maps();
2320 // Return symbol table section index.
2322 symtab_shndx() const
2323 { return this->symtab_shndx_
; }
2325 // Allow a child class to access the ELF file.
2326 elfcpp::Elf_file
<size
, big_endian
, Object
>*
2328 { return &this->elf_file_
; }
2330 // Allow a child class to access the local values.
2333 { return &this->local_values_
; }
2335 // Views and sizes when relocating.
2338 unsigned char* view
;
2339 typename
elfcpp::Elf_types
<size
>::Elf_Addr address
;
2341 section_size_type view_size
;
2342 bool is_input_output_view
;
2343 bool is_postprocessing_view
;
2344 bool is_ctors_reverse_view
;
2347 typedef std::vector
<View_size
> Views
;
2349 // This may be overriden by a child class.
2351 do_relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2352 const unsigned char* pshdrs
, Output_file
* of
,
2355 // Allow a child to set output local symbol count.
2357 set_output_local_symbol_count(unsigned int value
)
2358 { this->output_local_symbol_count_
= value
; }
2360 // Return TRUE if the section is a compressed debug section, and set
2361 // *UNCOMPRESSED_SIZE to the size of the uncompressed data.
2363 do_section_is_compressed(unsigned int shndx
,
2364 section_size_type
* uncompressed_size
) const
2366 if (this->compressed_sections_
== NULL
)
2368 Compressed_section_map::const_iterator p
=
2369 this->compressed_sections_
->find(shndx
);
2370 if (p
!= this->compressed_sections_
->end())
2372 if (uncompressed_size
!= NULL
)
2373 *uncompressed_size
= p
->second
.size
;
2379 // Return a view of the uncompressed contents of a section. Set *PLEN
2380 // to the size. Set *IS_NEW to true if the contents need to be deleted
2382 const unsigned char*
2383 do_decompressed_section_contents(unsigned int shndx
,
2384 section_size_type
* plen
,
2387 // Discard any buffers of decompressed sections. This is done
2388 // at the end of the Add_symbols task.
2390 do_discard_decompressed_sections();
2394 typedef Sized_relobj_file
<size
, big_endian
> This
;
2395 static const int ehdr_size
= elfcpp::Elf_sizes
<size
>::ehdr_size
;
2396 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2397 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2398 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
2400 // To keep track of discarded comdat sections, we need to map a member
2401 // section index to the object and section index of the corresponding
2403 struct Kept_comdat_section
2405 Kept_comdat_section(Relobj
* a_object
, unsigned int a_shndx
)
2406 : object(a_object
), shndx(a_shndx
)
2411 typedef std::map
<unsigned int, Kept_comdat_section
>
2412 Kept_comdat_section_table
;
2414 // Find the SHT_SYMTAB section, given the section headers.
2416 find_symtab(const unsigned char* pshdrs
);
2418 // Return whether SHDR has the right flags for a GNU style exception
2421 check_eh_frame_flags(const elfcpp::Shdr
<size
, big_endian
>* shdr
) const;
2423 // Return whether there is a section named .eh_frame which might be
2424 // a GNU style exception frame section.
2426 find_eh_frame(const unsigned char* pshdrs
, const char* names
,
2427 section_size_type names_size
) const;
2429 // Whether to include a section group in the link.
2431 include_section_group(Symbol_table
*, Layout
*, unsigned int, const char*,
2432 const unsigned char*, const char*, section_size_type
,
2433 std::vector
<bool>*);
2435 // Whether to include a linkonce section in the link.
2437 include_linkonce_section(Layout
*, unsigned int, const char*,
2438 const elfcpp::Shdr
<size
, big_endian
>&);
2440 // Layout an input section.
2442 layout_section(Layout
* layout
, unsigned int shndx
, const char* name
,
2443 const typename
This::Shdr
& shdr
, unsigned int reloc_shndx
,
2444 unsigned int reloc_type
);
2446 // Layout an input .eh_frame section.
2448 layout_eh_frame_section(Layout
* layout
, const unsigned char* symbols_data
,
2449 section_size_type symbols_size
,
2450 const unsigned char* symbol_names_data
,
2451 section_size_type symbol_names_size
,
2452 unsigned int shndx
, const typename
This::Shdr
&,
2453 unsigned int reloc_shndx
, unsigned int reloc_type
);
2455 // Write section data to the output file. Record the views and
2456 // sizes in VIEWS for use when relocating.
2458 write_sections(const Layout
*, const unsigned char* pshdrs
, Output_file
*,
2461 // Relocate the sections in the output file.
2463 relocate_sections(const Symbol_table
* symtab
, const Layout
* layout
,
2464 const unsigned char* pshdrs
, Output_file
* of
,
2466 { this->do_relocate_sections(symtab
, layout
, pshdrs
, of
, pviews
); }
2468 // Reverse the words in a section. Used for .ctors sections mapped
2469 // to .init_array sections.
2471 reverse_words(unsigned char*, section_size_type
);
2473 // Scan the input relocations for --emit-relocs.
2475 emit_relocs_scan(Symbol_table
*, Layout
*, const unsigned char* plocal_syms
,
2476 const Read_relocs_data::Relocs_list::iterator
&);
2478 // Scan the input relocations for --emit-relocs, templatized on the
2479 // type of the relocation section.
2480 template<int sh_type
>
2482 emit_relocs_scan_reltype(Symbol_table
*, Layout
*,
2483 const unsigned char* plocal_syms
,
2484 const Read_relocs_data::Relocs_list::iterator
&,
2485 Relocatable_relocs
*);
2487 // Emit the relocs for --emit-relocs.
2489 emit_relocs(const Relocate_info
<size
, big_endian
>*, unsigned int,
2490 unsigned int sh_type
, const unsigned char* prelocs
,
2491 size_t reloc_count
, Output_section
*, Address output_offset
,
2492 unsigned char* view
, Address address
,
2493 section_size_type view_size
,
2494 unsigned char* reloc_view
, section_size_type reloc_view_size
);
2496 // Emit the relocs for --emit-relocs, templatized on the type of the
2497 // relocation section.
2498 template<int sh_type
>
2500 emit_relocs_reltype(const Relocate_info
<size
, big_endian
>*, unsigned int,
2501 const unsigned char* prelocs
, size_t reloc_count
,
2502 Output_section
*, Address output_offset
,
2503 unsigned char* view
, Address address
,
2504 section_size_type view_size
,
2505 unsigned char* reloc_view
,
2506 section_size_type reloc_view_size
);
2508 // Scan the input relocations for --incremental.
2510 incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator
&);
2512 // Scan the input relocations for --incremental, templatized on the
2513 // type of the relocation section.
2514 template<int sh_type
>
2516 incremental_relocs_scan_reltype(
2517 const Read_relocs_data::Relocs_list::iterator
&);
2520 incremental_relocs_write(const Relocate_info
<size
, big_endian
>*,
2521 unsigned int sh_type
,
2522 const unsigned char* prelocs
,
2525 Address output_offset
,
2528 template<int sh_type
>
2530 incremental_relocs_write_reltype(const Relocate_info
<size
, big_endian
>*,
2531 const unsigned char* prelocs
,
2534 Address output_offset
,
2537 // A type shared by split_stack_adjust_reltype and find_functions.
2538 typedef std::map
<section_offset_type
, section_size_type
> Function_offsets
;
2540 // Check for -fsplit-stack routines calling non-split-stack routines.
2542 split_stack_adjust(const Symbol_table
*, const unsigned char* pshdrs
,
2543 unsigned int sh_type
, unsigned int shndx
,
2544 const unsigned char* prelocs
, size_t reloc_count
,
2545 unsigned char* view
, section_size_type view_size
,
2546 Reloc_symbol_changes
** reloc_map
);
2548 template<int sh_type
>
2550 split_stack_adjust_reltype(const Symbol_table
*, const unsigned char* pshdrs
,
2551 unsigned int shndx
, const unsigned char* prelocs
,
2552 size_t reloc_count
, unsigned char* view
,
2553 section_size_type view_size
,
2554 Reloc_symbol_changes
** reloc_map
);
2556 // Find all functions in a section.
2558 find_functions(const unsigned char* pshdrs
, unsigned int shndx
,
2561 // Write out the local symbols.
2563 write_local_symbols(Output_file
*,
2564 const Stringpool_template
<char>*,
2565 const Stringpool_template
<char>*,
2566 Output_symtab_xindex
*,
2567 Output_symtab_xindex
*,
2570 // Record a mapping from discarded section SHNDX to the corresponding
2573 set_kept_comdat_section(unsigned int shndx
, Relobj
* kept_object
,
2574 unsigned int kept_shndx
)
2576 Kept_comdat_section
kept(kept_object
, kept_shndx
);
2577 this->kept_comdat_sections_
.insert(std::make_pair(shndx
, kept
));
2580 // Find the kept section corresponding to the discarded section
2581 // SHNDX. Return true if found.
2583 get_kept_comdat_section(unsigned int shndx
, Relobj
** kept_object
,
2584 unsigned int* kept_shndx
) const
2586 typename
Kept_comdat_section_table::const_iterator p
=
2587 this->kept_comdat_sections_
.find(shndx
);
2588 if (p
== this->kept_comdat_sections_
.end())
2590 *kept_object
= p
->second
.object
;
2591 *kept_shndx
= p
->second
.shndx
;
2595 // Compute final local symbol value. R_SYM is the local symbol index.
2596 // LV_IN points to a local symbol value containing the input value.
2597 // LV_OUT points to a local symbol value storing the final output value,
2598 // which must not be a merged symbol value since before calling this
2599 // method to avoid memory leak. RELOCATABLE indicates whether we are
2600 // linking a relocatable output. OUT_SECTIONS is an array of output
2601 // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB
2602 // points to a symbol table.
2604 // The method returns a status code at return. If the return status is
2605 // CFLV_OK, *LV_OUT contains the final value. If the return status is
2606 // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED,
2607 // *LV_OUT is not modified.
2608 inline Compute_final_local_value_status
2609 compute_final_local_value_internal(unsigned int r_sym
,
2610 const Symbol_value
<size
>* lv_in
,
2611 Symbol_value
<size
>* lv_out
,
2613 const Output_sections
& out_sections
,
2614 const std::vector
<Address
>& out_offsets
,
2615 const Symbol_table
* symtab
);
2617 // The PLT offsets of local symbols.
2618 typedef Unordered_map
<unsigned int, unsigned int> Local_plt_offsets
;
2620 // Saved information for sections whose layout was deferred.
2621 struct Deferred_layout
2623 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
2624 Deferred_layout(unsigned int shndx
, const char* name
,
2625 const unsigned char* pshdr
,
2626 unsigned int reloc_shndx
, unsigned int reloc_type
)
2627 : shndx_(shndx
), name_(name
), reloc_shndx_(reloc_shndx
),
2628 reloc_type_(reloc_type
)
2630 memcpy(this->shdr_data_
, pshdr
, shdr_size
);
2632 unsigned int shndx_
;
2634 unsigned int reloc_shndx_
;
2635 unsigned int reloc_type_
;
2636 unsigned char shdr_data_
[shdr_size
];
2639 // General access to the ELF file.
2640 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
2641 // Type of ELF file (ET_REL or ET_EXEC). ET_EXEC files are allowed
2642 // as input files only for the --just-symbols option.
2644 // Index of SHT_SYMTAB section.
2645 unsigned int symtab_shndx_
;
2646 // The number of local symbols.
2647 unsigned int local_symbol_count_
;
2648 // The number of local symbols which go into the output file.
2649 unsigned int output_local_symbol_count_
;
2650 // The number of local symbols which go into the output file's dynamic
2652 unsigned int output_local_dynsym_count_
;
2653 // The entries in the symbol table for the external symbols.
2655 // Number of symbols defined in object file itself.
2656 size_t defined_count_
;
2657 // File offset for local symbols (relative to start of symbol table).
2658 off_t local_symbol_offset_
;
2659 // File offset for local dynamic symbols (absolute).
2660 off_t local_dynsym_offset_
;
2661 // Values of local symbols.
2662 Local_values local_values_
;
2663 // PLT offsets for local symbols.
2664 Local_plt_offsets local_plt_offsets_
;
2665 // Table mapping discarded comdat sections to corresponding kept sections.
2666 Kept_comdat_section_table kept_comdat_sections_
;
2667 // Whether this object has a GNU style .eh_frame section.
2669 // If this object has a GNU style .eh_frame section that is discarded in
2670 // output, record the index here. Otherwise it is -1U.
2671 unsigned int discarded_eh_frame_shndx_
;
2672 // The list of sections whose layout was deferred.
2673 std::vector
<Deferred_layout
> deferred_layout_
;
2674 // The list of relocation sections whose layout was deferred.
2675 std::vector
<Deferred_layout
> deferred_layout_relocs_
;
2676 // For compressed debug sections, map section index to uncompressed size
2678 Compressed_section_map
* compressed_sections_
;
2681 // A class to manage the list of all objects.
2687 : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL
)
2690 // The type of the list of input relocateable objects.
2691 typedef std::vector
<Relobj
*> Relobj_list
;
2692 typedef Relobj_list::const_iterator Relobj_iterator
;
2694 // The type of the list of input dynamic objects.
2695 typedef std::vector
<Dynobj
*> Dynobj_list
;
2696 typedef Dynobj_list::const_iterator Dynobj_iterator
;
2698 // Add an object to the list. Return true if all is well, or false
2699 // if this object should be ignored.
2701 add_object(Object
*);
2703 // Start processing an archive.
2705 archive_start(Archive
*);
2707 // Stop processing an archive.
2709 archive_stop(Archive
*);
2711 // For each dynamic object, check whether we've seen all of its
2712 // explicit dependencies.
2714 check_dynamic_dependencies() const;
2716 // Return whether an object was found in the system library
2719 found_in_system_library_directory(const Object
*) const;
2721 // Print symbol counts.
2723 print_symbol_counts(const Symbol_table
*) const;
2725 // Print a cross reference table.
2727 print_cref(const Symbol_table
*, FILE*) const;
2729 // Iterate over all regular objects.
2732 relobj_begin() const
2733 { return this->relobj_list_
.begin(); }
2737 { return this->relobj_list_
.end(); }
2739 // Iterate over all dynamic objects.
2742 dynobj_begin() const
2743 { return this->dynobj_list_
.begin(); }
2747 { return this->dynobj_list_
.end(); }
2749 // Return whether we have seen any dynamic objects.
2752 { return !this->dynobj_list_
.empty(); }
2754 // Return the number of non dynamic objects.
2756 number_of_relobjs() const
2757 { return this->relobj_list_
.size(); }
2759 // Return the number of input objects.
2761 number_of_input_objects() const
2762 { return this->relobj_list_
.size() + this->dynobj_list_
.size(); }
2765 Input_objects(const Input_objects
&);
2766 Input_objects
& operator=(const Input_objects
&);
2768 // The list of ordinary objects included in the link.
2769 Relobj_list relobj_list_
;
2770 // The list of dynamic objects included in the link.
2771 Dynobj_list dynobj_list_
;
2772 // SONAMEs that we have seen.
2773 Unordered_set
<std::string
> sonames_
;
2774 // Manage cross-references if requested.
2778 // Some of the information we pass to the relocation routines. We
2779 // group this together to avoid passing a dozen different arguments.
2781 template<int size
, bool big_endian
>
2782 struct Relocate_info
2785 const Symbol_table
* symtab
;
2787 const Layout
* layout
;
2788 // Object being relocated.
2789 Sized_relobj_file
<size
, big_endian
>* object
;
2790 // Section index of relocation section.
2791 unsigned int reloc_shndx
;
2792 // Section header of relocation section.
2793 const unsigned char* reloc_shdr
;
2794 // Section index of section being relocated.
2795 unsigned int data_shndx
;
2796 // Section header of data section.
2797 const unsigned char* data_shdr
;
2799 // Return a string showing the location of a relocation. This is
2800 // only used for error messages.
2802 location(size_t relnum
, off_t reloffset
) const;
2805 // This is used to represent a section in an object and is used as the
2806 // key type for various section maps.
2807 typedef std::pair
<Object
*, unsigned int> Section_id
;
2809 // This is similar to Section_id but is used when the section
2810 // pointers are const.
2811 typedef std::pair
<const Object
*, unsigned int> Const_section_id
;
2813 // The hash value is based on the address of an object in memory during
2814 // linking. It is okay to use this for looking up sections but never use
2815 // this in an unordered container that we want to traverse in a repeatable
2818 struct Section_id_hash
2820 size_t operator()(const Section_id
& loc
) const
2821 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2824 struct Const_section_id_hash
2826 size_t operator()(const Const_section_id
& loc
) const
2827 { return reinterpret_cast<uintptr_t>(loc
.first
) ^ loc
.second
; }
2830 // Return whether INPUT_FILE contains an ELF object start at file
2831 // offset OFFSET. This sets *START to point to a view of the start of
2832 // the file. It sets *READ_SIZE to the number of bytes in the view.
2835 is_elf_object(Input_file
* input_file
, off_t offset
,
2836 const unsigned char** start
, int* read_size
);
2838 // Return an Object appropriate for the input file. P is BYTES long,
2839 // and holds the ELF header. If PUNCONFIGURED is not NULL, then if
2840 // this sees an object the linker is not configured to support, it
2841 // sets *PUNCONFIGURED to true and returns NULL without giving an
2845 make_elf_object(const std::string
& name
, Input_file
*,
2846 off_t offset
, const unsigned char* p
,
2847 section_offset_type bytes
, bool* punconfigured
);
2849 } // end namespace gold
2851 #endif // !defined(GOLD_OBJECT_H)