1 // symtab.h -- the gold symbol table -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
34 #include "parameters.h"
35 #include "stringpool.h"
44 template<int size
, bool big_endian
>
46 template<int size
, bool big_endian
>
47 class Sized_pluginobj
;
49 template<int size
, bool big_endian
>
52 class Version_script_info
;
58 class Output_symtab_xindex
;
59 class Garbage_collection
;
62 // The base class of an entry in the symbol table. The symbol table
63 // can have a lot of entries, so we don't want this class to big.
64 // Size dependent fields can be found in the template class
65 // Sized_symbol. Targets may support their own derived classes.
70 // Because we want the class to be small, we don't use any virtual
71 // functions. But because symbols can be defined in different
72 // places, we need to classify them. This enum is the different
73 // sources of symbols we support.
76 // Symbol defined in a relocatable or dynamic input file--this is
77 // the most common case.
79 // Symbol defined in an Output_data, a special section created by
82 // Symbol defined in an Output_segment, with no associated
85 // Symbol value is constant.
87 // Symbol is undefined.
91 // When the source is IN_OUTPUT_SEGMENT, we need to describe what
93 enum Segment_offset_base
95 // From the start of the segment.
97 // From the end of the segment.
99 // From the filesz of the segment--i.e., after the loaded bytes
100 // but before the bytes which are allocated but zeroed.
104 // Return the symbol name.
107 { return this->name_
; }
109 // Return the (ANSI) demangled version of the name, if
110 // parameters.demangle() is true. Otherwise, return the name. This
111 // is intended to be used only for logging errors, so it's not
114 demangled_name() const;
116 // Return the symbol version. This will return NULL for an
117 // unversioned symbol.
120 { return this->version_
; }
122 // Return whether this version is the default for this symbol name
123 // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only
124 // meaningful for versioned symbols.
128 gold_assert(this->version_
!= NULL
);
129 return this->is_def_
;
132 // Set that this version is the default for this symbol name.
135 { this->is_def_
= true; }
137 // Return the symbol source.
140 { return this->source_
; }
142 // Return the object with which this symbol is associated.
146 gold_assert(this->source_
== FROM_OBJECT
);
147 return this->u_
.from_object
.object
;
150 // Return the index of the section in the input relocatable or
151 // dynamic object file.
153 shndx(bool* is_ordinary
) const
155 gold_assert(this->source_
== FROM_OBJECT
);
156 *is_ordinary
= this->is_ordinary_shndx_
;
157 return this->u_
.from_object
.shndx
;
160 // Return the output data section with which this symbol is
161 // associated, if the symbol was specially defined with respect to
162 // an output data section.
166 gold_assert(this->source_
== IN_OUTPUT_DATA
);
167 return this->u_
.in_output_data
.output_data
;
170 // If this symbol was defined with respect to an output data
171 // section, return whether the value is an offset from end.
173 offset_is_from_end() const
175 gold_assert(this->source_
== IN_OUTPUT_DATA
);
176 return this->u_
.in_output_data
.offset_is_from_end
;
179 // Return the output segment with which this symbol is associated,
180 // if the symbol was specially defined with respect to an output
183 output_segment() const
185 gold_assert(this->source_
== IN_OUTPUT_SEGMENT
);
186 return this->u_
.in_output_segment
.output_segment
;
189 // If this symbol was defined with respect to an output segment,
190 // return the offset base.
194 gold_assert(this->source_
== IN_OUTPUT_SEGMENT
);
195 return this->u_
.in_output_segment
.offset_base
;
198 // Return the symbol binding.
201 { return this->binding_
; }
203 // Return the symbol type.
206 { return this->type_
; }
208 // Return true for function symbol.
212 return (this->type_
== elfcpp::STT_FUNC
213 || this->type_
== elfcpp::STT_GNU_IFUNC
);
216 // Return the symbol visibility.
219 { return this->visibility_
; }
221 // Set the visibility.
223 set_visibility(elfcpp::STV visibility
)
224 { this->visibility_
= visibility
; }
226 // Override symbol visibility.
228 override_visibility(elfcpp::STV
);
230 // Set whether the symbol was originally a weak undef or a regular undef
231 // when resolved by a dynamic def.
233 set_undef_binding(elfcpp::STB bind
)
235 if (!this->undef_binding_set_
|| this->undef_binding_weak_
)
237 this->undef_binding_weak_
= bind
== elfcpp::STB_WEAK
;
238 this->undef_binding_set_
= true;
242 // Return TRUE if a weak undef was resolved by a dynamic def.
244 is_undef_binding_weak() const
245 { return this->undef_binding_weak_
; }
247 // Return the non-visibility part of the st_other field.
250 { return this->nonvis_
; }
252 // Return whether this symbol is a forwarder. This will never be
253 // true of a symbol found in the hash table, but may be true of
254 // symbol pointers attached to object files.
257 { return this->is_forwarder_
; }
259 // Mark this symbol as a forwarder.
262 { this->is_forwarder_
= true; }
264 // Return whether this symbol has an alias in the weak aliases table
268 { return this->has_alias_
; }
270 // Mark this symbol as having an alias.
273 { this->has_alias_
= true; }
275 // Return whether this symbol needs an entry in the dynamic symbol
278 needs_dynsym_entry() const
280 return (this->needs_dynsym_entry_
283 && this->is_externally_visible()));
286 // Mark this symbol as needing an entry in the dynamic symbol table.
288 set_needs_dynsym_entry()
289 { this->needs_dynsym_entry_
= true; }
291 // Return whether this symbol should be added to the dynamic symbol
294 should_add_dynsym_entry(Symbol_table
*) const;
296 // Return whether this symbol has been seen in a regular object.
299 { return this->in_reg_
; }
301 // Mark this symbol as having been seen in a regular object.
304 { this->in_reg_
= true; }
306 // Return whether this symbol has been seen in a dynamic object.
309 { return this->in_dyn_
; }
311 // Mark this symbol as having been seen in a dynamic object.
314 { this->in_dyn_
= true; }
316 // Return whether this symbol has been seen in a real ELF object.
317 // (IN_REG will return TRUE if the symbol has been seen in either
318 // a real ELF object or an object claimed by a plugin.)
321 { return this->in_real_elf_
; }
323 // Mark this symbol as having been seen in a real ELF object.
326 { this->in_real_elf_
= true; }
328 // Return whether this symbol was defined in a section that was
329 // discarded from the link. This is used to control some error
332 is_defined_in_discarded_section() const
333 { return this->is_defined_in_discarded_section_
; }
335 // Mark this symbol as having been defined in a discarded section.
337 set_is_defined_in_discarded_section()
338 { this->is_defined_in_discarded_section_
= true; }
340 // Return the index of this symbol in the output file symbol table.
341 // A value of -1U means that this symbol is not going into the
342 // output file. This starts out as zero, and is set to a non-zero
343 // value by Symbol_table::finalize. It is an error to ask for the
344 // symbol table index before it has been set.
348 gold_assert(this->symtab_index_
!= 0);
349 return this->symtab_index_
;
352 // Set the index of the symbol in the output file symbol table.
354 set_symtab_index(unsigned int index
)
356 gold_assert(index
!= 0);
357 this->symtab_index_
= index
;
360 // Return whether this symbol already has an index in the output
361 // file symbol table.
363 has_symtab_index() const
364 { return this->symtab_index_
!= 0; }
366 // Return the index of this symbol in the dynamic symbol table. A
367 // value of -1U means that this symbol is not going into the dynamic
368 // symbol table. This starts out as zero, and is set to a non-zero
369 // during Layout::finalize. It is an error to ask for the dynamic
370 // symbol table index before it has been set.
374 gold_assert(this->dynsym_index_
!= 0);
375 return this->dynsym_index_
;
378 // Set the index of the symbol in the dynamic symbol table.
380 set_dynsym_index(unsigned int index
)
382 gold_assert(index
!= 0);
383 this->dynsym_index_
= index
;
386 // Return whether this symbol already has an index in the dynamic
389 has_dynsym_index() const
390 { return this->dynsym_index_
!= 0; }
392 // Return whether this symbol has an entry in the GOT section.
393 // For a TLS symbol, this GOT entry will hold its tp-relative offset.
395 has_got_offset(unsigned int got_type
) const
396 { return this->got_offsets_
.get_offset(got_type
) != -1U; }
398 // Return the offset into the GOT section of this symbol.
400 got_offset(unsigned int got_type
) const
402 unsigned int got_offset
= this->got_offsets_
.get_offset(got_type
);
403 gold_assert(got_offset
!= -1U);
407 // Set the GOT offset of this symbol.
409 set_got_offset(unsigned int got_type
, unsigned int got_offset
)
410 { this->got_offsets_
.set_offset(got_type
, got_offset
); }
412 // Return the GOT offset list.
413 const Got_offset_list
*
414 got_offset_list() const
415 { return this->got_offsets_
.get_list(); }
417 // Return whether this symbol has an entry in the PLT section.
419 has_plt_offset() const
420 { return this->plt_offset_
!= -1U; }
422 // Return the offset into the PLT section of this symbol.
426 gold_assert(this->has_plt_offset());
427 return this->plt_offset_
;
430 // Set the PLT offset of this symbol.
432 set_plt_offset(unsigned int plt_offset
)
434 gold_assert(plt_offset
!= -1U);
435 this->plt_offset_
= plt_offset
;
438 // Return whether this dynamic symbol needs a special value in the
439 // dynamic symbol table.
441 needs_dynsym_value() const
442 { return this->needs_dynsym_value_
; }
444 // Set that this dynamic symbol needs a special value in the dynamic
447 set_needs_dynsym_value()
449 gold_assert(this->object()->is_dynamic());
450 this->needs_dynsym_value_
= true;
453 // Return true if the final value of this symbol is known at link
456 final_value_is_known() const;
458 // Return true if SHNDX represents a common symbol. This depends on
461 is_common_shndx(unsigned int shndx
);
463 // Return whether this is a defined symbol (not undefined or
469 if (this->source_
!= FROM_OBJECT
)
470 return this->source_
!= IS_UNDEFINED
;
471 unsigned int shndx
= this->shndx(&is_ordinary
);
473 ? shndx
!= elfcpp::SHN_UNDEF
474 : !Symbol::is_common_shndx(shndx
));
477 // Return true if this symbol is from a dynamic object.
479 is_from_dynobj() const
481 return this->source_
== FROM_OBJECT
&& this->object()->is_dynamic();
484 // Return whether this is a placeholder symbol from a plugin object.
486 is_placeholder() const
488 return this->source_
== FROM_OBJECT
&& this->object()->pluginobj() != NULL
;
491 // Return whether this is an undefined symbol.
496 return ((this->source_
== FROM_OBJECT
497 && this->shndx(&is_ordinary
) == elfcpp::SHN_UNDEF
499 || this->source_
== IS_UNDEFINED
);
502 // Return whether this is a weak undefined symbol.
504 is_weak_undefined() const
505 { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK
; }
507 // Return whether this is an absolute symbol.
512 return ((this->source_
== FROM_OBJECT
513 && this->shndx(&is_ordinary
) == elfcpp::SHN_ABS
515 || this->source_
== IS_CONSTANT
);
518 // Return whether this is a common symbol.
522 if (this->source_
!= FROM_OBJECT
)
524 if (this->type_
== elfcpp::STT_COMMON
)
527 unsigned int shndx
= this->shndx(&is_ordinary
);
528 return !is_ordinary
&& Symbol::is_common_shndx(shndx
);
531 // Return whether this symbol can be seen outside this object.
533 is_externally_visible() const
535 return (this->visibility_
== elfcpp::STV_DEFAULT
536 || this->visibility_
== elfcpp::STV_PROTECTED
);
539 // Return true if this symbol can be preempted by a definition in
540 // another link unit.
542 is_preemptible() const
544 // It doesn't make sense to ask whether a symbol defined in
545 // another object is preemptible.
546 gold_assert(!this->is_from_dynobj());
548 // It doesn't make sense to ask whether an undefined symbol
550 gold_assert(!this->is_undefined());
552 // If a symbol does not have default visibility, it can not be
553 // seen outside this link unit and therefore is not preemptible.
554 if (this->visibility_
!= elfcpp::STV_DEFAULT
)
557 // If this symbol has been forced to be a local symbol by a
558 // version script, then it is not visible outside this link unit
559 // and is not preemptible.
560 if (this->is_forced_local_
)
563 // If we are not producing a shared library, then nothing is
565 if (!parameters
->options().shared())
568 // If the user used -Bsymbolic, then nothing is preemptible.
569 if (parameters
->options().Bsymbolic())
572 // If the user used -Bsymbolic-functions, then functions are not
573 // preemptible. We explicitly check for not being STT_OBJECT,
574 // rather than for being STT_FUNC, because that is what the GNU
576 if (this->type() != elfcpp::STT_OBJECT
577 && parameters
->options().Bsymbolic_functions())
580 // Otherwise the symbol is preemptible.
584 // Return true if this symbol is a function that needs a PLT entry.
585 // If the symbol is defined in a dynamic object or if it is subject
586 // to pre-emption, we need to make a PLT entry. If we're doing a
587 // static link or a -pie link, we don't create PLT entries.
589 needs_plt_entry() const
591 // An undefined symbol from an executable does not need a PLT entry.
592 if (this->is_undefined() && !parameters
->options().shared())
595 return (!parameters
->doing_static_link()
596 && !parameters
->options().pie()
598 && (this->is_from_dynobj()
599 || this->is_undefined()
600 || this->is_preemptible()));
603 // When determining whether a reference to a symbol needs a dynamic
604 // relocation, we need to know several things about the reference.
605 // These flags may be or'ed together.
608 // Reference to the symbol's absolute address.
610 // A non-PIC reference.
616 // Given a direct absolute or pc-relative static relocation against
617 // the global symbol, this function returns whether a dynamic relocation
621 needs_dynamic_reloc(int flags
) const
623 // No dynamic relocations in a static link!
624 if (parameters
->doing_static_link())
627 // A reference to an undefined symbol from an executable should be
628 // statically resolved to 0, and does not need a dynamic relocation.
629 // This matches gnu ld behavior.
630 if (this->is_undefined() && !parameters
->options().shared())
633 // A reference to an absolute symbol does not need a dynamic relocation.
634 if (this->is_absolute())
637 // An absolute reference within a position-independent output file
638 // will need a dynamic relocation.
639 if ((flags
& ABSOLUTE_REF
)
640 && parameters
->options().output_is_position_independent())
643 // A function call that can branch to a local PLT entry does not need
644 // a dynamic relocation. A non-pic pc-relative function call in a
645 // shared library cannot use a PLT entry.
646 if ((flags
& FUNCTION_CALL
)
647 && this->has_plt_offset()
648 && !((flags
& NON_PIC_REF
) && parameters
->options().shared()))
651 // A reference to any PLT entry in a non-position-independent executable
652 // does not need a dynamic relocation.
653 if (!parameters
->options().output_is_position_independent()
654 && this->has_plt_offset())
657 // A reference to a symbol defined in a dynamic object or to a
658 // symbol that is preemptible will need a dynamic relocation.
659 if (this->is_from_dynobj()
660 || this->is_undefined()
661 || this->is_preemptible())
664 // For all other cases, return FALSE.
668 // Whether we should use the PLT offset associated with a symbol for
669 // a relocation. IS_NON_PIC_REFERENCE is true if this is a non-PIC
670 // reloc--the same set of relocs for which we would pass NON_PIC_REF
671 // to the needs_dynamic_reloc function.
674 use_plt_offset(bool is_non_pic_reference
) const
676 // If the symbol doesn't have a PLT offset, then naturally we
677 // don't want to use it.
678 if (!this->has_plt_offset())
681 // If we are going to generate a dynamic relocation, then we will
682 // wind up using that, so no need to use the PLT entry.
683 if (this->needs_dynamic_reloc(FUNCTION_CALL
684 | (is_non_pic_reference
689 // If the symbol is from a dynamic object, we need to use the PLT
691 if (this->is_from_dynobj())
694 // If we are generating a shared object, and this symbol is
695 // undefined or preemptible, we need to use the PLT entry.
696 if (parameters
->options().shared()
697 && (this->is_undefined() || this->is_preemptible()))
700 // If this is a weak undefined symbol, we need to use the PLT
701 // entry; the symbol may be defined by a library loaded at
703 if (this->is_weak_undefined())
706 // Otherwise we can use the regular definition.
710 // Given a direct absolute static relocation against
711 // the global symbol, where a dynamic relocation is needed, this
712 // function returns whether a relative dynamic relocation can be used.
713 // The caller must determine separately whether the static relocation
714 // is compatible with a relative relocation.
717 can_use_relative_reloc(bool is_function_call
) const
719 // A function call that can branch to a local PLT entry can
720 // use a RELATIVE relocation.
721 if (is_function_call
&& this->has_plt_offset())
724 // A reference to a symbol defined in a dynamic object or to a
725 // symbol that is preemptible can not use a RELATIVE relocaiton.
726 if (this->is_from_dynobj()
727 || this->is_undefined()
728 || this->is_preemptible())
731 // For all other cases, return TRUE.
735 // Return the output section where this symbol is defined. Return
736 // NULL if the symbol has an absolute value.
738 output_section() const;
740 // Set the symbol's output section. This is used for symbols
741 // defined in scripts. This should only be called after the symbol
742 // table has been finalized.
744 set_output_section(Output_section
*);
746 // Return whether there should be a warning for references to this
750 { return this->has_warning_
; }
752 // Mark this symbol as having a warning.
755 { this->has_warning_
= true; }
757 // Return whether this symbol is defined by a COPY reloc from a
760 is_copied_from_dynobj() const
761 { return this->is_copied_from_dynobj_
; }
763 // Mark this symbol as defined by a COPY reloc.
765 set_is_copied_from_dynobj()
766 { this->is_copied_from_dynobj_
= true; }
768 // Return whether this symbol is forced to visibility STB_LOCAL
769 // by a "local:" entry in a version script.
771 is_forced_local() const
772 { return this->is_forced_local_
; }
774 // Mark this symbol as forced to STB_LOCAL visibility.
776 set_is_forced_local()
777 { this->is_forced_local_
= true; }
779 // Return true if this may need a COPY relocation.
780 // References from an executable object to non-function symbols
781 // defined in a dynamic object may need a COPY relocation.
783 may_need_copy_reloc() const
785 return (!parameters
->options().shared()
786 && parameters
->options().copyreloc()
787 && this->is_from_dynobj()
788 && !this->is_func());
792 // Instances of this class should always be created at a specific
795 { memset(this, 0, sizeof *this); }
797 // Initialize the general fields.
799 init_fields(const char* name
, const char* version
,
800 elfcpp::STT type
, elfcpp::STB binding
,
801 elfcpp::STV visibility
, unsigned char nonvis
);
803 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
804 // section index, IS_ORDINARY is whether it is a normal section
805 // index rather than a special code.
806 template<int size
, bool big_endian
>
808 init_base_object(const char *name
, const char* version
, Object
* object
,
809 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
812 // Initialize fields for an Output_data.
814 init_base_output_data(const char* name
, const char* version
, Output_data
*,
815 elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
816 unsigned char nonvis
, bool offset_is_from_end
);
818 // Initialize fields for an Output_segment.
820 init_base_output_segment(const char* name
, const char* version
,
821 Output_segment
* os
, elfcpp::STT type
,
822 elfcpp::STB binding
, elfcpp::STV visibility
,
823 unsigned char nonvis
,
824 Segment_offset_base offset_base
);
826 // Initialize fields for a constant.
828 init_base_constant(const char* name
, const char* version
, elfcpp::STT type
,
829 elfcpp::STB binding
, elfcpp::STV visibility
,
830 unsigned char nonvis
);
832 // Initialize fields for an undefined symbol.
834 init_base_undefined(const char* name
, const char* version
, elfcpp::STT type
,
835 elfcpp::STB binding
, elfcpp::STV visibility
,
836 unsigned char nonvis
);
838 // Override existing symbol.
839 template<int size
, bool big_endian
>
841 override_base(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
842 bool is_ordinary
, Object
* object
, const char* version
);
844 // Override existing symbol with a special symbol.
846 override_base_with_special(const Symbol
* from
);
848 // Override symbol version.
850 override_version(const char* version
);
852 // Allocate a common symbol by giving it a location in the output
855 allocate_base_common(Output_data
*);
858 Symbol(const Symbol
&);
859 Symbol
& operator=(const Symbol
&);
861 // Symbol name (expected to point into a Stringpool).
863 // Symbol version (expected to point into a Stringpool). This may
865 const char* version_
;
869 // This struct is used if SOURCE_ == FROM_OBJECT.
872 // Object in which symbol is defined, or in which it was first
875 // Section number in object_ in which symbol is defined.
879 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
882 // Output_data in which symbol is defined. Before
883 // Layout::finalize the symbol's value is an offset within the
885 Output_data
* output_data
;
886 // True if the offset is from the end, false if the offset is
887 // from the beginning.
888 bool offset_is_from_end
;
891 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
894 // Output_segment in which the symbol is defined. Before
895 // Layout::finalize the symbol's value is an offset.
896 Output_segment
* output_segment
;
897 // The base to use for the offset before Layout::finalize.
898 Segment_offset_base offset_base
;
902 // The index of this symbol in the output file. If the symbol is
903 // not going into the output file, this value is -1U. This field
904 // starts as always holding zero. It is set to a non-zero value by
905 // Symbol_table::finalize.
906 unsigned int symtab_index_
;
908 // The index of this symbol in the dynamic symbol table. If the
909 // symbol is not going into the dynamic symbol table, this value is
910 // -1U. This field starts as always holding zero. It is set to a
911 // non-zero value during Layout::finalize.
912 unsigned int dynsym_index_
;
914 // The GOT section entries for this symbol. A symbol may have more
915 // than one GOT offset (e.g., when mixing modules compiled with two
916 // different TLS models), but will usually have at most one.
917 Got_offset_list got_offsets_
;
919 // If this symbol has an entry in the PLT section, then this is the
920 // offset from the start of the PLT section. This is -1U if there
922 unsigned int plt_offset_
;
924 // Symbol type (bits 0 to 3).
925 elfcpp::STT type_
: 4;
926 // Symbol binding (bits 4 to 7).
927 elfcpp::STB binding_
: 4;
928 // Symbol visibility (bits 8 to 9).
929 elfcpp::STV visibility_
: 2;
930 // Rest of symbol st_other field (bits 10 to 15).
931 unsigned int nonvis_
: 6;
932 // The type of symbol (bits 16 to 18).
934 // True if this is the default version of the symbol (bit 19).
936 // True if this symbol really forwards to another symbol. This is
937 // used when we discover after the fact that two different entries
938 // in the hash table really refer to the same symbol. This will
939 // never be set for a symbol found in the hash table, but may be set
940 // for a symbol found in the list of symbols attached to an Object.
941 // It forwards to the symbol found in the forwarders_ map of
942 // Symbol_table (bit 20).
943 bool is_forwarder_
: 1;
944 // True if the symbol has an alias in the weak_aliases table in
945 // Symbol_table (bit 21).
947 // True if this symbol needs to be in the dynamic symbol table (bit
949 bool needs_dynsym_entry_
: 1;
950 // True if we've seen this symbol in a regular object (bit 23).
952 // True if we've seen this symbol in a dynamic object (bit 24).
954 // True if this is a dynamic symbol which needs a special value in
955 // the dynamic symbol table (bit 25).
956 bool needs_dynsym_value_
: 1;
957 // True if there is a warning for this symbol (bit 26).
958 bool has_warning_
: 1;
959 // True if we are using a COPY reloc for this symbol, so that the
960 // real definition lives in a dynamic object (bit 27).
961 bool is_copied_from_dynobj_
: 1;
962 // True if this symbol was forced to local visibility by a version
964 bool is_forced_local_
: 1;
965 // True if the field u_.from_object.shndx is an ordinary section
966 // index, not one of the special codes from SHN_LORESERVE to
967 // SHN_HIRESERVE (bit 29).
968 bool is_ordinary_shndx_
: 1;
969 // True if we've seen this symbol in a real ELF object (bit 30).
970 bool in_real_elf_
: 1;
971 // True if this symbol is defined in a section which was discarded
973 bool is_defined_in_discarded_section_
: 1;
974 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
975 bool undef_binding_set_
: 1;
976 // True if this symbol was a weak undef resolved by a dynamic def
978 bool undef_binding_weak_
: 1;
981 // The parts of a symbol which are size specific. Using a template
982 // derived class like this helps us use less space on a 32-bit system.
985 class Sized_symbol
: public Symbol
988 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value_type
;
989 typedef typename
elfcpp::Elf_types
<size
>::Elf_WXword Size_type
;
994 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
995 // section index, IS_ORDINARY is whether it is a normal section
996 // index rather than a special code.
997 template<bool big_endian
>
999 init_object(const char *name
, const char* version
, Object
* object
,
1000 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1003 // Initialize fields for an Output_data.
1005 init_output_data(const char* name
, const char* version
, Output_data
*,
1006 Value_type value
, Size_type symsize
, elfcpp::STT
,
1007 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1008 bool offset_is_from_end
);
1010 // Initialize fields for an Output_segment.
1012 init_output_segment(const char* name
, const char* version
, Output_segment
*,
1013 Value_type value
, Size_type symsize
, elfcpp::STT
,
1014 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1015 Segment_offset_base offset_base
);
1017 // Initialize fields for a constant.
1019 init_constant(const char* name
, const char* version
, Value_type value
,
1020 Size_type symsize
, elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
1021 unsigned char nonvis
);
1023 // Initialize fields for an undefined symbol.
1025 init_undefined(const char* name
, const char* version
, elfcpp::STT
,
1026 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
);
1028 // Override existing symbol.
1029 template<bool big_endian
>
1031 override(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1032 bool is_ordinary
, Object
* object
, const char* version
);
1034 // Override existing symbol with a special symbol.
1036 override_with_special(const Sized_symbol
<size
>*);
1038 // Return the symbol's value.
1041 { return this->value_
; }
1043 // Return the symbol's size (we can't call this 'size' because that
1044 // is a template parameter).
1047 { return this->symsize_
; }
1049 // Set the symbol size. This is used when resolving common symbols.
1051 set_symsize(Size_type symsize
)
1052 { this->symsize_
= symsize
; }
1054 // Set the symbol value. This is called when we store the final
1055 // values of the symbols into the symbol table.
1057 set_value(Value_type value
)
1058 { this->value_
= value
; }
1060 // Allocate a common symbol by giving it a location in the output
1063 allocate_common(Output_data
*, Value_type value
);
1066 Sized_symbol(const Sized_symbol
&);
1067 Sized_symbol
& operator=(const Sized_symbol
&);
1069 // Symbol value. Before Layout::finalize this is the offset in the
1070 // input section. This is set to the final value during
1071 // Layout::finalize.
1077 // A struct describing a symbol defined by the linker, where the value
1078 // of the symbol is defined based on an output section. This is used
1079 // for symbols defined by the linker, like "_init_array_start".
1081 struct Define_symbol_in_section
1085 // The name of the output section with which this symbol should be
1086 // associated. If there is no output section with that name, the
1087 // symbol will be defined as zero.
1088 const char* output_section
;
1089 // The offset of the symbol within the output section. This is an
1090 // offset from the start of the output section, unless start_at_end
1091 // is true, in which case this is an offset from the end of the
1094 // The size of the symbol.
1098 // The symbol binding.
1099 elfcpp::STB binding
;
1100 // The symbol visibility.
1101 elfcpp::STV visibility
;
1102 // The rest of the st_other field.
1103 unsigned char nonvis
;
1104 // If true, the value field is an offset from the end of the output
1106 bool offset_is_from_end
;
1107 // If true, this symbol is defined only if we see a reference to it.
1111 // A struct describing a symbol defined by the linker, where the value
1112 // of the symbol is defined based on a segment. This is used for
1113 // symbols defined by the linker, like "_end". We describe the
1114 // segment with which the symbol should be associated by its
1115 // characteristics. If no segment meets these characteristics, the
1116 // symbol will be defined as zero. If there is more than one segment
1117 // which meets these characteristics, we will use the first one.
1119 struct Define_symbol_in_segment
1123 // The segment type where the symbol should be defined, typically
1125 elfcpp::PT segment_type
;
1126 // Bitmask of segment flags which must be set.
1127 elfcpp::PF segment_flags_set
;
1128 // Bitmask of segment flags which must be clear.
1129 elfcpp::PF segment_flags_clear
;
1130 // The offset of the symbol within the segment. The offset is
1131 // calculated from the position set by offset_base.
1133 // The size of the symbol.
1137 // The symbol binding.
1138 elfcpp::STB binding
;
1139 // The symbol visibility.
1140 elfcpp::STV visibility
;
1141 // The rest of the st_other field.
1142 unsigned char nonvis
;
1143 // The base from which we compute the offset.
1144 Symbol::Segment_offset_base offset_base
;
1145 // If true, this symbol is defined only if we see a reference to it.
1149 // This class manages warnings. Warnings are a GNU extension. When
1150 // we see a section named .gnu.warning.SYM in an object file, and if
1151 // we wind using the definition of SYM from that object file, then we
1152 // will issue a warning for any relocation against SYM from a
1153 // different object file. The text of the warning is the contents of
1154 // the section. This is not precisely the definition used by the old
1155 // GNU linker; the old GNU linker treated an occurrence of
1156 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1157 // would trigger a warning on any reference. However, it was
1158 // inconsistent in that a warning in a dynamic object only triggered
1159 // if there was no definition in a regular object. This linker is
1160 // different in that we only issue a warning if we use the symbol
1161 // definition from the same object file as the warning section.
1170 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1173 add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
1174 const std::string
& warning
);
1176 // For each symbol for which we should give a warning, make a note
1179 note_warnings(Symbol_table
* symtab
);
1181 // Issue a warning for a reference to SYM at RELINFO's location.
1182 template<int size
, bool big_endian
>
1184 issue_warning(const Symbol
* sym
, const Relocate_info
<size
, big_endian
>*,
1185 size_t relnum
, off_t reloffset
) const;
1188 Warnings(const Warnings
&);
1189 Warnings
& operator=(const Warnings
&);
1191 // What we need to know to get the warning text.
1192 struct Warning_location
1194 // The object the warning is in.
1196 // The warning text.
1200 : object(NULL
), text()
1204 set(Object
* o
, const std::string
& t
)
1211 // A mapping from warning symbol names (canonicalized in
1212 // Symbol_table's namepool_ field) to warning information.
1213 typedef Unordered_map
<const char*, Warning_location
> Warning_table
;
1215 Warning_table warnings_
;
1218 // The main linker symbol table.
1223 // The different places where a symbol definition can come from.
1226 // Defined in an object file--the normal case.
1228 // Defined for a COPY reloc.
1230 // Defined on the command line using --defsym.
1232 // Defined (so to speak) on the command line using -u.
1234 // Defined in a linker script.
1236 // Predefined by the linker.
1240 // The order in which we sort common symbols.
1241 enum Sort_commons_order
1243 SORT_COMMONS_BY_SIZE_DESCENDING
,
1244 SORT_COMMONS_BY_ALIGNMENT_DESCENDING
,
1245 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1248 // COUNT is an estimate of how many symbosl will be inserted in the
1249 // symbol table. It's ok to put 0 if you don't know; a correct
1250 // guess will just save some CPU by reducing hashtable resizes.
1251 Symbol_table(unsigned int count
, const Version_script_info
& version_script
);
1257 { this->icf_
= icf
;}
1261 { return this->icf_
; }
1263 // Returns true if ICF determined that this is a duplicate section.
1265 is_section_folded(Object
* obj
, unsigned int shndx
) const;
1268 set_gc(Garbage_collection
* gc
)
1273 { return this->gc_
; }
1275 // During garbage collection, this keeps undefined symbols.
1277 gc_mark_undef_symbols(Layout
*);
1279 // During garbage collection, this ensures externally visible symbols
1280 // are not treated as garbage while building shared objects.
1282 gc_mark_symbol_for_shlib(Symbol
* sym
);
1284 // During garbage collection, this keeps sections that correspond to
1285 // symbols seen in dynamic objects.
1287 gc_mark_dyn_syms(Symbol
* sym
);
1289 // Add COUNT external symbols from the relocatable object RELOBJ to
1290 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1291 // offset in the symbol table of the first symbol, SYM_NAMES is
1292 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1293 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1294 // *DEFINED to the number of defined symbols.
1295 template<int size
, bool big_endian
>
1297 add_from_relobj(Sized_relobj
<size
, big_endian
>* relobj
,
1298 const unsigned char* syms
, size_t count
,
1299 size_t symndx_offset
, const char* sym_names
,
1300 size_t sym_name_size
,
1301 typename Sized_relobj
<size
, big_endian
>::Symbols
*,
1304 // Add one external symbol from the plugin object OBJ to the symbol table.
1305 // Returns a pointer to the resolved symbol in the symbol table.
1306 template<int size
, bool big_endian
>
1308 add_from_pluginobj(Sized_pluginobj
<size
, big_endian
>* obj
,
1309 const char* name
, const char* ver
,
1310 elfcpp::Sym
<size
, big_endian
>* sym
);
1312 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1313 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1314 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1315 // symbol version data.
1316 template<int size
, bool big_endian
>
1318 add_from_dynobj(Sized_dynobj
<size
, big_endian
>* dynobj
,
1319 const unsigned char* syms
, size_t count
,
1320 const char* sym_names
, size_t sym_name_size
,
1321 const unsigned char* versym
, size_t versym_size
,
1322 const std::vector
<const char*>*,
1323 typename Sized_relobj
<size
, big_endian
>::Symbols
*,
1326 // Define a special symbol based on an Output_data. It is a
1327 // multiple definition error if this symbol is already defined.
1329 define_in_output_data(const char* name
, const char* version
, Defined
,
1330 Output_data
*, uint64_t value
, uint64_t symsize
,
1331 elfcpp::STT type
, elfcpp::STB binding
,
1332 elfcpp::STV visibility
, unsigned char nonvis
,
1333 bool offset_is_from_end
, bool only_if_ref
);
1335 // Define a special symbol based on an Output_segment. It is a
1336 // multiple definition error if this symbol is already defined.
1338 define_in_output_segment(const char* name
, const char* version
, Defined
,
1339 Output_segment
*, uint64_t value
, uint64_t symsize
,
1340 elfcpp::STT type
, elfcpp::STB binding
,
1341 elfcpp::STV visibility
, unsigned char nonvis
,
1342 Symbol::Segment_offset_base
, bool only_if_ref
);
1344 // Define a special symbol with a constant value. It is a multiple
1345 // definition error if this symbol is already defined.
1347 define_as_constant(const char* name
, const char* version
, Defined
,
1348 uint64_t value
, uint64_t symsize
, elfcpp::STT type
,
1349 elfcpp::STB binding
, elfcpp::STV visibility
,
1350 unsigned char nonvis
, bool only_if_ref
,
1351 bool force_override
);
1353 // Define a set of symbols in output sections. If ONLY_IF_REF is
1354 // true, only define them if they are referenced.
1356 define_symbols(const Layout
*, int count
, const Define_symbol_in_section
*,
1359 // Define a set of symbols in output segments. If ONLY_IF_REF is
1360 // true, only defined them if they are referenced.
1362 define_symbols(const Layout
*, int count
, const Define_symbol_in_segment
*,
1365 // Define SYM using a COPY reloc. POSD is the Output_data where the
1366 // symbol should be defined--typically a .dyn.bss section. VALUE is
1367 // the offset within POSD.
1370 define_with_copy_reloc(Sized_symbol
<size
>* sym
, Output_data
* posd
,
1371 typename
elfcpp::Elf_types
<size
>::Elf_Addr
);
1373 // Look up a symbol.
1375 lookup(const char*, const char* version
= NULL
) const;
1377 // Return the real symbol associated with the forwarder symbol FROM.
1379 resolve_forwards(const Symbol
* from
) const;
1381 // Return the sized version of a symbol in this table.
1384 get_sized_symbol(Symbol
*) const;
1387 const Sized_symbol
<size
>*
1388 get_sized_symbol(const Symbol
*) const;
1390 // Return the count of undefined symbols seen.
1392 saw_undefined() const
1393 { return this->saw_undefined_
; }
1395 // Allocate the common symbols
1397 allocate_commons(Layout
*, Mapfile
*);
1399 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1402 add_warning(const char* name
, Object
* obj
, const std::string
& warning
)
1403 { this->warnings_
.add_warning(this, name
, obj
, warning
); }
1405 // Canonicalize a symbol name for use in the hash table.
1407 canonicalize_name(const char* name
)
1408 { return this->namepool_
.add(name
, true, NULL
); }
1410 // Possibly issue a warning for a reference to SYM at LOCATION which
1412 template<int size
, bool big_endian
>
1414 issue_warning(const Symbol
* sym
,
1415 const Relocate_info
<size
, big_endian
>* relinfo
,
1416 size_t relnum
, off_t reloffset
) const
1417 { this->warnings_
.issue_warning(sym
, relinfo
, relnum
, reloffset
); }
1419 // Check candidate_odr_violations_ to find symbols with the same name
1420 // but apparently different definitions (different source-file/line-no).
1422 detect_odr_violations(const Task
*, const char* output_file_name
) const;
1424 // Add any undefined symbols named on the command line to the symbol
1427 add_undefined_symbols_from_command_line(Layout
*);
1429 // SYM is defined using a COPY reloc. Return the dynamic object
1430 // where the original definition was found.
1432 get_copy_source(const Symbol
* sym
) const;
1434 // Set the dynamic symbol indexes. INDEX is the index of the first
1435 // global dynamic symbol. Pointers to the symbols are stored into
1436 // the vector. The names are stored into the Stringpool. This
1437 // returns an updated dynamic symbol index.
1439 set_dynsym_indexes(unsigned int index
, std::vector
<Symbol
*>*,
1440 Stringpool
*, Versions
*);
1442 // Finalize the symbol table after we have set the final addresses
1443 // of all the input sections. This sets the final symbol indexes,
1444 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1445 // index of the first global symbol. OFF is the file offset of the
1446 // global symbol table, DYNOFF is the offset of the globals in the
1447 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1448 // global dynamic symbol, and DYNCOUNT is the number of global
1449 // dynamic symbols. This records the parameters, and returns the
1450 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1453 finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
, size_t dyncount
,
1454 Stringpool
* pool
, unsigned int *plocal_symcount
);
1456 // Status code of Symbol_table::compute_final_value.
1457 enum Compute_final_value_status
1461 // Unspported symbol section.
1462 CFVS_UNSUPPORTED_SYMBOL_SECTION
,
1463 // No output section.
1464 CFVS_NO_OUTPUT_SECTION
1467 // Compute the final value of SYM and store status in location PSTATUS.
1468 // During relaxation, this may be called multiple times for a symbol to
1469 // compute its would-be final value in each relaxation pass.
1472 typename Sized_symbol
<size
>::Value_type
1473 compute_final_value(const Sized_symbol
<size
>* sym
,
1474 Compute_final_value_status
* pstatus
) const;
1476 // Return the index of the first global symbol.
1478 first_global_index() const
1479 { return this->first_global_index_
; }
1481 // Return the total number of symbols in the symbol table.
1483 output_count() const
1484 { return this->output_count_
; }
1486 // Write out the global symbols.
1488 write_globals(const Stringpool
*, const Stringpool
*,
1489 Output_symtab_xindex
*, Output_symtab_xindex
*,
1490 Output_file
*) const;
1492 // Write out a section symbol. Return the updated offset.
1494 write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1495 Output_file
*, off_t
) const;
1497 // Loop over all symbols, applying the function F to each.
1498 template<int size
, typename F
>
1500 for_all_symbols(F f
) const
1502 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1503 p
!= this->table_
.end();
1506 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1511 // Dump statistical information to stderr.
1513 print_stats() const;
1515 // Return the version script information.
1516 const Version_script_info
&
1517 version_script() const
1518 { return version_script_
; }
1521 Symbol_table(const Symbol_table
&);
1522 Symbol_table
& operator=(const Symbol_table
&);
1524 // The type of the list of common symbols.
1525 typedef std::vector
<Symbol
*> Commons_type
;
1527 // The type of the symbol hash table.
1529 typedef std::pair
<Stringpool::Key
, Stringpool::Key
> Symbol_table_key
;
1531 struct Symbol_table_hash
1534 operator()(const Symbol_table_key
&) const;
1537 struct Symbol_table_eq
1540 operator()(const Symbol_table_key
&, const Symbol_table_key
&) const;
1543 typedef Unordered_map
<Symbol_table_key
, Symbol
*, Symbol_table_hash
,
1544 Symbol_table_eq
> Symbol_table_type
;
1546 // Make FROM a forwarder symbol to TO.
1548 make_forwarder(Symbol
* from
, Symbol
* to
);
1551 template<int size
, bool big_endian
>
1553 add_from_object(Object
*, const char *name
, Stringpool::Key name_key
,
1554 const char *version
, Stringpool::Key version_key
,
1555 bool def
, const elfcpp::Sym
<size
, big_endian
>& sym
,
1556 unsigned int st_shndx
, bool is_ordinary
,
1557 unsigned int orig_st_shndx
);
1559 // Define a default symbol.
1560 template<int size
, bool big_endian
>
1562 define_default_version(Sized_symbol
<size
>*, bool,
1563 Symbol_table_type::iterator
);
1566 template<int size
, bool big_endian
>
1568 resolve(Sized_symbol
<size
>* to
,
1569 const elfcpp::Sym
<size
, big_endian
>& sym
,
1570 unsigned int st_shndx
, bool is_ordinary
,
1571 unsigned int orig_st_shndx
,
1572 Object
*, const char* version
);
1574 template<int size
, bool big_endian
>
1576 resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
);
1578 // Record that a symbol is forced to be local by a version script or
1581 force_local(Symbol
*);
1583 // Adjust NAME and *NAME_KEY for wrapping.
1585 wrap_symbol(const char* name
, Stringpool::Key
* name_key
);
1587 // Whether we should override a symbol, based on flags in
1590 should_override(const Symbol
*, unsigned int, Defined
, Object
*, bool*, bool*);
1592 // Report a problem in symbol resolution.
1594 report_resolve_problem(bool is_error
, const char* msg
, const Symbol
* to
,
1595 Defined
, Object
* object
);
1597 // Override a symbol.
1598 template<int size
, bool big_endian
>
1600 override(Sized_symbol
<size
>* tosym
,
1601 const elfcpp::Sym
<size
, big_endian
>& fromsym
,
1602 unsigned int st_shndx
, bool is_ordinary
,
1603 Object
* object
, const char* version
);
1605 // Whether we should override a symbol with a special symbol which
1606 // is automatically defined by the linker.
1608 should_override_with_special(const Symbol
*, Defined
);
1610 // Override a symbol with a special symbol.
1613 override_with_special(Sized_symbol
<size
>* tosym
,
1614 const Sized_symbol
<size
>* fromsym
);
1616 // Record all weak alias sets for a dynamic object.
1619 record_weak_aliases(std::vector
<Sized_symbol
<size
>*>*);
1621 // Define a special symbol.
1622 template<int size
, bool big_endian
>
1624 define_special_symbol(const char** pname
, const char** pversion
,
1625 bool only_if_ref
, Sized_symbol
<size
>** poldsym
,
1626 bool* resolve_oldsym
);
1628 // Define a symbol in an Output_data, sized version.
1631 do_define_in_output_data(const char* name
, const char* version
, Defined
,
1633 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1634 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1635 elfcpp::STT type
, elfcpp::STB binding
,
1636 elfcpp::STV visibility
, unsigned char nonvis
,
1637 bool offset_is_from_end
, bool only_if_ref
);
1639 // Define a symbol in an Output_segment, sized version.
1642 do_define_in_output_segment(
1643 const char* name
, const char* version
, Defined
, Output_segment
* os
,
1644 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1645 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1646 elfcpp::STT type
, elfcpp::STB binding
,
1647 elfcpp::STV visibility
, unsigned char nonvis
,
1648 Symbol::Segment_offset_base offset_base
, bool only_if_ref
);
1650 // Define a symbol as a constant, sized version.
1653 do_define_as_constant(
1654 const char* name
, const char* version
, Defined
,
1655 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1656 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1657 elfcpp::STT type
, elfcpp::STB binding
,
1658 elfcpp::STV visibility
, unsigned char nonvis
,
1659 bool only_if_ref
, bool force_override
);
1661 // Add any undefined symbols named on the command line to the symbol
1662 // table, sized version.
1665 do_add_undefined_symbols_from_command_line(Layout
*);
1667 // Add one undefined symbol.
1670 add_undefined_symbol_from_command_line(const char* name
);
1672 // Types of common symbols.
1674 enum Commons_section_type
1682 // Allocate the common symbols, sized version.
1685 do_allocate_commons(Layout
*, Mapfile
*, Sort_commons_order
);
1687 // Allocate the common symbols from one list.
1690 do_allocate_commons_list(Layout
*, Commons_section_type
, Commons_type
*,
1691 Mapfile
*, Sort_commons_order
);
1693 // Implement detect_odr_violations.
1694 template<int size
, bool big_endian
>
1696 sized_detect_odr_violations() const;
1698 // Finalize symbols specialized for size.
1701 sized_finalize(off_t
, Stringpool
*, unsigned int*);
1703 // Finalize a symbol. Return whether it should be added to the
1707 sized_finalize_symbol(Symbol
*);
1709 // Add a symbol the final symtab by setting its index.
1712 add_to_final_symtab(Symbol
*, Stringpool
*, unsigned int* pindex
, off_t
* poff
);
1714 // Write globals specialized for size and endianness.
1715 template<int size
, bool big_endian
>
1717 sized_write_globals(const Stringpool
*, const Stringpool
*,
1718 Output_symtab_xindex
*, Output_symtab_xindex
*,
1719 Output_file
*) const;
1721 // Write out a symbol to P.
1722 template<int size
, bool big_endian
>
1724 sized_write_symbol(Sized_symbol
<size
>*,
1725 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1726 unsigned int shndx
, elfcpp::STB
,
1727 const Stringpool
*, unsigned char* p
) const;
1729 // Possibly warn about an undefined symbol from a dynamic object.
1731 warn_about_undefined_dynobj_symbol(Symbol
*) const;
1733 // Write out a section symbol, specialized for size and endianness.
1734 template<int size
, bool big_endian
>
1736 sized_write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1737 Output_file
*, off_t
) const;
1739 // The type of the list of symbols which have been forced local.
1740 typedef std::vector
<Symbol
*> Forced_locals
;
1742 // A map from symbols with COPY relocs to the dynamic objects where
1743 // they are defined.
1744 typedef Unordered_map
<const Symbol
*, Dynobj
*> Copied_symbol_dynobjs
;
1746 // A map from symbol name (as a pointer into the namepool) to all
1747 // the locations the symbols is (weakly) defined (and certain other
1748 // conditions are met). This map will be used later to detect
1749 // possible One Definition Rule (ODR) violations.
1750 struct Symbol_location
1752 Object
* object
; // Object where the symbol is defined.
1753 unsigned int shndx
; // Section-in-object where the symbol is defined.
1754 off_t offset
; // Offset-in-section where the symbol is defined.
1755 bool operator==(const Symbol_location
& that
) const
1757 return (this->object
== that
.object
1758 && this->shndx
== that
.shndx
1759 && this->offset
== that
.offset
);
1763 struct Symbol_location_hash
1765 size_t operator()(const Symbol_location
& loc
) const
1766 { return reinterpret_cast<uintptr_t>(loc
.object
) ^ loc
.offset
^ loc
.shndx
; }
1769 typedef Unordered_map
<const char*,
1770 Unordered_set
<Symbol_location
, Symbol_location_hash
> >
1773 // We increment this every time we see a new undefined symbol, for
1774 // use in archive groups.
1775 size_t saw_undefined_
;
1776 // The index of the first global symbol in the output file.
1777 unsigned int first_global_index_
;
1778 // The file offset within the output symtab section where we should
1781 // The number of global symbols we want to write out.
1782 unsigned int output_count_
;
1783 // The file offset of the global dynamic symbols, or 0 if none.
1784 off_t dynamic_offset_
;
1785 // The index of the first global dynamic symbol.
1786 unsigned int first_dynamic_global_index_
;
1787 // The number of global dynamic symbols, or 0 if none.
1788 unsigned int dynamic_count_
;
1789 // The symbol hash table.
1790 Symbol_table_type table_
;
1791 // A pool of symbol names. This is used for all global symbols.
1792 // Entries in the hash table point into this pool.
1793 Stringpool namepool_
;
1794 // Forwarding symbols.
1795 Unordered_map
<const Symbol
*, Symbol
*> forwarders_
;
1796 // Weak aliases. A symbol in this list points to the next alias.
1797 // The aliases point to each other in a circular list.
1798 Unordered_map
<Symbol
*, Symbol
*> weak_aliases_
;
1799 // We don't expect there to be very many common symbols, so we keep
1800 // a list of them. When we find a common symbol we add it to this
1801 // list. It is possible that by the time we process the list the
1802 // symbol is no longer a common symbol. It may also have become a
1804 Commons_type commons_
;
1805 // This is like the commons_ field, except that it holds TLS common
1807 Commons_type tls_commons_
;
1808 // This is for small common symbols.
1809 Commons_type small_commons_
;
1810 // This is for large common symbols.
1811 Commons_type large_commons_
;
1812 // A list of symbols which have been forced to be local. We don't
1813 // expect there to be very many of them, so we keep a list of them
1814 // rather than walking the whole table to find them.
1815 Forced_locals forced_locals_
;
1816 // Manage symbol warnings.
1818 // Manage potential One Definition Rule (ODR) violations.
1819 Odr_map candidate_odr_violations_
;
1821 // When we emit a COPY reloc for a symbol, we define it in an
1822 // Output_data. When it's time to emit version information for it,
1823 // we need to know the dynamic object in which we found the original
1824 // definition. This maps symbols with COPY relocs to the dynamic
1825 // object where they were defined.
1826 Copied_symbol_dynobjs copied_symbol_dynobjs_
;
1827 // Information parsed from the version script, if any.
1828 const Version_script_info
& version_script_
;
1829 Garbage_collection
* gc_
;
1833 // We inline get_sized_symbol for efficiency.
1837 Symbol_table::get_sized_symbol(Symbol
* sym
) const
1839 gold_assert(size
== parameters
->target().get_size());
1840 return static_cast<Sized_symbol
<size
>*>(sym
);
1844 const Sized_symbol
<size
>*
1845 Symbol_table::get_sized_symbol(const Symbol
* sym
) const
1847 gold_assert(size
== parameters
->target().get_size());
1848 return static_cast<const Sized_symbol
<size
>*>(sym
);
1851 } // End namespace gold.
1853 #endif // !defined(GOLD_SYMTAB_H)