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.
586 needs_plt_entry() const
588 // An undefined symbol from an executable does not need a PLT entry.
589 if (this->is_undefined() && !parameters
->options().shared())
592 // An STT_GNU_IFUNC symbol always needs a PLT entry, even when
593 // doing a static link.
594 if (this->type() == elfcpp::STT_GNU_IFUNC
)
597 // We only need a PLT entry for a function.
598 if (!this->is_func())
601 // If we're doing a static link or a -pie link, we don't create
603 if (parameters
->doing_static_link()
604 || parameters
->options().pie())
607 // We need a PLT entry if the function is defined in a dynamic
608 // object, or is undefined when building a shared object, or if it
609 // is subject to pre-emption.
610 return (this->is_from_dynobj()
611 || this->is_undefined()
612 || this->is_preemptible());
615 // When determining whether a reference to a symbol needs a dynamic
616 // relocation, we need to know several things about the reference.
617 // These flags may be or'ed together.
620 // Reference to the symbol's absolute address.
622 // A non-PIC reference.
628 // Given a direct absolute or pc-relative static relocation against
629 // the global symbol, this function returns whether a dynamic relocation
633 needs_dynamic_reloc(int flags
) const
635 // No dynamic relocations in a static link!
636 if (parameters
->doing_static_link())
639 // A reference to an undefined symbol from an executable should be
640 // statically resolved to 0, and does not need a dynamic relocation.
641 // This matches gnu ld behavior.
642 if (this->is_undefined() && !parameters
->options().shared())
645 // A reference to an absolute symbol does not need a dynamic relocation.
646 if (this->is_absolute())
649 // An absolute reference within a position-independent output file
650 // will need a dynamic relocation.
651 if ((flags
& ABSOLUTE_REF
)
652 && parameters
->options().output_is_position_independent())
655 // A function call that can branch to a local PLT entry does not need
656 // a dynamic relocation. A non-pic pc-relative function call in a
657 // shared library cannot use a PLT entry.
658 if ((flags
& FUNCTION_CALL
)
659 && this->has_plt_offset()
660 && !((flags
& NON_PIC_REF
)
661 && parameters
->options().output_is_position_independent()))
664 // A reference to any PLT entry in a non-position-independent executable
665 // does not need a dynamic relocation.
666 if (!parameters
->options().output_is_position_independent()
667 && this->has_plt_offset())
670 // A reference to a symbol defined in a dynamic object or to a
671 // symbol that is preemptible will need a dynamic relocation.
672 if (this->is_from_dynobj()
673 || this->is_undefined()
674 || this->is_preemptible())
677 // For all other cases, return FALSE.
681 // Whether we should use the PLT offset associated with a symbol for
682 // a relocation. IS_NON_PIC_REFERENCE is true if this is a non-PIC
683 // reloc--the same set of relocs for which we would pass NON_PIC_REF
684 // to the needs_dynamic_reloc function.
687 use_plt_offset(bool is_non_pic_reference
) const
689 // If the symbol doesn't have a PLT offset, then naturally we
690 // don't want to use it.
691 if (!this->has_plt_offset())
694 // For a STT_GNU_IFUNC symbol we always have to use the PLT entry.
695 if (this->type() == elfcpp::STT_GNU_IFUNC
)
698 // If we are going to generate a dynamic relocation, then we will
699 // wind up using that, so no need to use the PLT entry.
700 if (this->needs_dynamic_reloc(FUNCTION_CALL
701 | (is_non_pic_reference
706 // If the symbol is from a dynamic object, we need to use the PLT
708 if (this->is_from_dynobj())
711 // If we are generating a shared object, and this symbol is
712 // undefined or preemptible, we need to use the PLT entry.
713 if (parameters
->options().shared()
714 && (this->is_undefined() || this->is_preemptible()))
717 // If this is a weak undefined symbol, we need to use the PLT
718 // entry; the symbol may be defined by a library loaded at
720 if (this->is_weak_undefined())
723 // Otherwise we can use the regular definition.
727 // Given a direct absolute static relocation against
728 // the global symbol, where a dynamic relocation is needed, this
729 // function returns whether a relative dynamic relocation can be used.
730 // The caller must determine separately whether the static relocation
731 // is compatible with a relative relocation.
734 can_use_relative_reloc(bool is_function_call
) const
736 // A function call that can branch to a local PLT entry can
737 // use a RELATIVE relocation.
738 if (is_function_call
&& this->has_plt_offset())
741 // A reference to a symbol defined in a dynamic object or to a
742 // symbol that is preemptible can not use a RELATIVE relocaiton.
743 if (this->is_from_dynobj()
744 || this->is_undefined()
745 || this->is_preemptible())
748 // For all other cases, return TRUE.
752 // Return the output section where this symbol is defined. Return
753 // NULL if the symbol has an absolute value.
755 output_section() const;
757 // Set the symbol's output section. This is used for symbols
758 // defined in scripts. This should only be called after the symbol
759 // table has been finalized.
761 set_output_section(Output_section
*);
763 // Return whether there should be a warning for references to this
767 { return this->has_warning_
; }
769 // Mark this symbol as having a warning.
772 { this->has_warning_
= true; }
774 // Return whether this symbol is defined by a COPY reloc from a
777 is_copied_from_dynobj() const
778 { return this->is_copied_from_dynobj_
; }
780 // Mark this symbol as defined by a COPY reloc.
782 set_is_copied_from_dynobj()
783 { this->is_copied_from_dynobj_
= true; }
785 // Return whether this symbol is forced to visibility STB_LOCAL
786 // by a "local:" entry in a version script.
788 is_forced_local() const
789 { return this->is_forced_local_
; }
791 // Mark this symbol as forced to STB_LOCAL visibility.
793 set_is_forced_local()
794 { this->is_forced_local_
= true; }
796 // Return true if this may need a COPY relocation.
797 // References from an executable object to non-function symbols
798 // defined in a dynamic object may need a COPY relocation.
800 may_need_copy_reloc() const
802 return (!parameters
->options().output_is_position_independent()
803 && parameters
->options().copyreloc()
804 && this->is_from_dynobj()
805 && !this->is_func());
809 // Instances of this class should always be created at a specific
812 { memset(this, 0, sizeof *this); }
814 // Initialize the general fields.
816 init_fields(const char* name
, const char* version
,
817 elfcpp::STT type
, elfcpp::STB binding
,
818 elfcpp::STV visibility
, unsigned char nonvis
);
820 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
821 // section index, IS_ORDINARY is whether it is a normal section
822 // index rather than a special code.
823 template<int size
, bool big_endian
>
825 init_base_object(const char* name
, const char* version
, Object
* object
,
826 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
829 // Initialize fields for an Output_data.
831 init_base_output_data(const char* name
, const char* version
, Output_data
*,
832 elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
833 unsigned char nonvis
, bool offset_is_from_end
);
835 // Initialize fields for an Output_segment.
837 init_base_output_segment(const char* name
, const char* version
,
838 Output_segment
* os
, elfcpp::STT type
,
839 elfcpp::STB binding
, elfcpp::STV visibility
,
840 unsigned char nonvis
,
841 Segment_offset_base offset_base
);
843 // Initialize fields for a constant.
845 init_base_constant(const char* name
, const char* version
, elfcpp::STT type
,
846 elfcpp::STB binding
, elfcpp::STV visibility
,
847 unsigned char nonvis
);
849 // Initialize fields for an undefined symbol.
851 init_base_undefined(const char* name
, const char* version
, elfcpp::STT type
,
852 elfcpp::STB binding
, elfcpp::STV visibility
,
853 unsigned char nonvis
);
855 // Override existing symbol.
856 template<int size
, bool big_endian
>
858 override_base(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
859 bool is_ordinary
, Object
* object
, const char* version
);
861 // Override existing symbol with a special symbol.
863 override_base_with_special(const Symbol
* from
);
865 // Override symbol version.
867 override_version(const char* version
);
869 // Allocate a common symbol by giving it a location in the output
872 allocate_base_common(Output_data
*);
875 Symbol(const Symbol
&);
876 Symbol
& operator=(const Symbol
&);
878 // Symbol name (expected to point into a Stringpool).
880 // Symbol version (expected to point into a Stringpool). This may
882 const char* version_
;
886 // This struct is used if SOURCE_ == FROM_OBJECT.
889 // Object in which symbol is defined, or in which it was first
892 // Section number in object_ in which symbol is defined.
896 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
899 // Output_data in which symbol is defined. Before
900 // Layout::finalize the symbol's value is an offset within the
902 Output_data
* output_data
;
903 // True if the offset is from the end, false if the offset is
904 // from the beginning.
905 bool offset_is_from_end
;
908 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
911 // Output_segment in which the symbol is defined. Before
912 // Layout::finalize the symbol's value is an offset.
913 Output_segment
* output_segment
;
914 // The base to use for the offset before Layout::finalize.
915 Segment_offset_base offset_base
;
919 // The index of this symbol in the output file. If the symbol is
920 // not going into the output file, this value is -1U. This field
921 // starts as always holding zero. It is set to a non-zero value by
922 // Symbol_table::finalize.
923 unsigned int symtab_index_
;
925 // The index of this symbol in the dynamic symbol table. If the
926 // symbol is not going into the dynamic symbol table, this value is
927 // -1U. This field starts as always holding zero. It is set to a
928 // non-zero value during Layout::finalize.
929 unsigned int dynsym_index_
;
931 // The GOT section entries for this symbol. A symbol may have more
932 // than one GOT offset (e.g., when mixing modules compiled with two
933 // different TLS models), but will usually have at most one.
934 Got_offset_list got_offsets_
;
936 // If this symbol has an entry in the PLT section, then this is the
937 // offset from the start of the PLT section. This is -1U if there
939 unsigned int plt_offset_
;
941 // Symbol type (bits 0 to 3).
942 elfcpp::STT type_
: 4;
943 // Symbol binding (bits 4 to 7).
944 elfcpp::STB binding_
: 4;
945 // Symbol visibility (bits 8 to 9).
946 elfcpp::STV visibility_
: 2;
947 // Rest of symbol st_other field (bits 10 to 15).
948 unsigned int nonvis_
: 6;
949 // The type of symbol (bits 16 to 18).
951 // True if this is the default version of the symbol (bit 19).
953 // True if this symbol really forwards to another symbol. This is
954 // used when we discover after the fact that two different entries
955 // in the hash table really refer to the same symbol. This will
956 // never be set for a symbol found in the hash table, but may be set
957 // for a symbol found in the list of symbols attached to an Object.
958 // It forwards to the symbol found in the forwarders_ map of
959 // Symbol_table (bit 20).
960 bool is_forwarder_
: 1;
961 // True if the symbol has an alias in the weak_aliases table in
962 // Symbol_table (bit 21).
964 // True if this symbol needs to be in the dynamic symbol table (bit
966 bool needs_dynsym_entry_
: 1;
967 // True if we've seen this symbol in a regular object (bit 23).
969 // True if we've seen this symbol in a dynamic object (bit 24).
971 // True if this is a dynamic symbol which needs a special value in
972 // the dynamic symbol table (bit 25).
973 bool needs_dynsym_value_
: 1;
974 // True if there is a warning for this symbol (bit 26).
975 bool has_warning_
: 1;
976 // True if we are using a COPY reloc for this symbol, so that the
977 // real definition lives in a dynamic object (bit 27).
978 bool is_copied_from_dynobj_
: 1;
979 // True if this symbol was forced to local visibility by a version
981 bool is_forced_local_
: 1;
982 // True if the field u_.from_object.shndx is an ordinary section
983 // index, not one of the special codes from SHN_LORESERVE to
984 // SHN_HIRESERVE (bit 29).
985 bool is_ordinary_shndx_
: 1;
986 // True if we've seen this symbol in a real ELF object (bit 30).
987 bool in_real_elf_
: 1;
988 // True if this symbol is defined in a section which was discarded
990 bool is_defined_in_discarded_section_
: 1;
991 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
992 bool undef_binding_set_
: 1;
993 // True if this symbol was a weak undef resolved by a dynamic def
995 bool undef_binding_weak_
: 1;
998 // The parts of a symbol which are size specific. Using a template
999 // derived class like this helps us use less space on a 32-bit system.
1002 class Sized_symbol
: public Symbol
1005 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value_type
;
1006 typedef typename
elfcpp::Elf_types
<size
>::Elf_WXword Size_type
;
1011 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
1012 // section index, IS_ORDINARY is whether it is a normal section
1013 // index rather than a special code.
1014 template<bool big_endian
>
1016 init_object(const char* name
, const char* version
, Object
* object
,
1017 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1020 // Initialize fields for an Output_data.
1022 init_output_data(const char* name
, const char* version
, Output_data
*,
1023 Value_type value
, Size_type symsize
, elfcpp::STT
,
1024 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1025 bool offset_is_from_end
);
1027 // Initialize fields for an Output_segment.
1029 init_output_segment(const char* name
, const char* version
, Output_segment
*,
1030 Value_type value
, Size_type symsize
, elfcpp::STT
,
1031 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1032 Segment_offset_base offset_base
);
1034 // Initialize fields for a constant.
1036 init_constant(const char* name
, const char* version
, Value_type value
,
1037 Size_type symsize
, elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
1038 unsigned char nonvis
);
1040 // Initialize fields for an undefined symbol.
1042 init_undefined(const char* name
, const char* version
, elfcpp::STT
,
1043 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
);
1045 // Override existing symbol.
1046 template<bool big_endian
>
1048 override(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1049 bool is_ordinary
, Object
* object
, const char* version
);
1051 // Override existing symbol with a special symbol.
1053 override_with_special(const Sized_symbol
<size
>*);
1055 // Return the symbol's value.
1058 { return this->value_
; }
1060 // Return the symbol's size (we can't call this 'size' because that
1061 // is a template parameter).
1064 { return this->symsize_
; }
1066 // Set the symbol size. This is used when resolving common symbols.
1068 set_symsize(Size_type symsize
)
1069 { this->symsize_
= symsize
; }
1071 // Set the symbol value. This is called when we store the final
1072 // values of the symbols into the symbol table.
1074 set_value(Value_type value
)
1075 { this->value_
= value
; }
1077 // Allocate a common symbol by giving it a location in the output
1080 allocate_common(Output_data
*, Value_type value
);
1083 Sized_symbol(const Sized_symbol
&);
1084 Sized_symbol
& operator=(const Sized_symbol
&);
1086 // Symbol value. Before Layout::finalize this is the offset in the
1087 // input section. This is set to the final value during
1088 // Layout::finalize.
1094 // A struct describing a symbol defined by the linker, where the value
1095 // of the symbol is defined based on an output section. This is used
1096 // for symbols defined by the linker, like "_init_array_start".
1098 struct Define_symbol_in_section
1102 // The name of the output section with which this symbol should be
1103 // associated. If there is no output section with that name, the
1104 // symbol will be defined as zero.
1105 const char* output_section
;
1106 // The offset of the symbol within the output section. This is an
1107 // offset from the start of the output section, unless start_at_end
1108 // is true, in which case this is an offset from the end of the
1111 // The size of the symbol.
1115 // The symbol binding.
1116 elfcpp::STB binding
;
1117 // The symbol visibility.
1118 elfcpp::STV visibility
;
1119 // The rest of the st_other field.
1120 unsigned char nonvis
;
1121 // If true, the value field is an offset from the end of the output
1123 bool offset_is_from_end
;
1124 // If true, this symbol is defined only if we see a reference to it.
1128 // A struct describing a symbol defined by the linker, where the value
1129 // of the symbol is defined based on a segment. This is used for
1130 // symbols defined by the linker, like "_end". We describe the
1131 // segment with which the symbol should be associated by its
1132 // characteristics. If no segment meets these characteristics, the
1133 // symbol will be defined as zero. If there is more than one segment
1134 // which meets these characteristics, we will use the first one.
1136 struct Define_symbol_in_segment
1140 // The segment type where the symbol should be defined, typically
1142 elfcpp::PT segment_type
;
1143 // Bitmask of segment flags which must be set.
1144 elfcpp::PF segment_flags_set
;
1145 // Bitmask of segment flags which must be clear.
1146 elfcpp::PF segment_flags_clear
;
1147 // The offset of the symbol within the segment. The offset is
1148 // calculated from the position set by offset_base.
1150 // The size of the symbol.
1154 // The symbol binding.
1155 elfcpp::STB binding
;
1156 // The symbol visibility.
1157 elfcpp::STV visibility
;
1158 // The rest of the st_other field.
1159 unsigned char nonvis
;
1160 // The base from which we compute the offset.
1161 Symbol::Segment_offset_base offset_base
;
1162 // If true, this symbol is defined only if we see a reference to it.
1166 // This class manages warnings. Warnings are a GNU extension. When
1167 // we see a section named .gnu.warning.SYM in an object file, and if
1168 // we wind using the definition of SYM from that object file, then we
1169 // will issue a warning for any relocation against SYM from a
1170 // different object file. The text of the warning is the contents of
1171 // the section. This is not precisely the definition used by the old
1172 // GNU linker; the old GNU linker treated an occurrence of
1173 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1174 // would trigger a warning on any reference. However, it was
1175 // inconsistent in that a warning in a dynamic object only triggered
1176 // if there was no definition in a regular object. This linker is
1177 // different in that we only issue a warning if we use the symbol
1178 // definition from the same object file as the warning section.
1187 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1190 add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
1191 const std::string
& warning
);
1193 // For each symbol for which we should give a warning, make a note
1196 note_warnings(Symbol_table
* symtab
);
1198 // Issue a warning for a reference to SYM at RELINFO's location.
1199 template<int size
, bool big_endian
>
1201 issue_warning(const Symbol
* sym
, const Relocate_info
<size
, big_endian
>*,
1202 size_t relnum
, off_t reloffset
) const;
1205 Warnings(const Warnings
&);
1206 Warnings
& operator=(const Warnings
&);
1208 // What we need to know to get the warning text.
1209 struct Warning_location
1211 // The object the warning is in.
1213 // The warning text.
1217 : object(NULL
), text()
1221 set(Object
* o
, const std::string
& t
)
1228 // A mapping from warning symbol names (canonicalized in
1229 // Symbol_table's namepool_ field) to warning information.
1230 typedef Unordered_map
<const char*, Warning_location
> Warning_table
;
1232 Warning_table warnings_
;
1235 // The main linker symbol table.
1240 // The different places where a symbol definition can come from.
1243 // Defined in an object file--the normal case.
1245 // Defined for a COPY reloc.
1247 // Defined on the command line using --defsym.
1249 // Defined (so to speak) on the command line using -u.
1251 // Defined in a linker script.
1253 // Predefined by the linker.
1257 // The order in which we sort common symbols.
1258 enum Sort_commons_order
1260 SORT_COMMONS_BY_SIZE_DESCENDING
,
1261 SORT_COMMONS_BY_ALIGNMENT_DESCENDING
,
1262 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1265 // COUNT is an estimate of how many symbosl will be inserted in the
1266 // symbol table. It's ok to put 0 if you don't know; a correct
1267 // guess will just save some CPU by reducing hashtable resizes.
1268 Symbol_table(unsigned int count
, const Version_script_info
& version_script
);
1274 { this->icf_
= icf
;}
1278 { return this->icf_
; }
1280 // Returns true if ICF determined that this is a duplicate section.
1282 is_section_folded(Object
* obj
, unsigned int shndx
) const;
1285 set_gc(Garbage_collection
* gc
)
1290 { return this->gc_
; }
1292 // During garbage collection, this keeps undefined symbols.
1294 gc_mark_undef_symbols(Layout
*);
1296 // During garbage collection, this ensures externally visible symbols
1297 // are not treated as garbage while building shared objects.
1299 gc_mark_symbol_for_shlib(Symbol
* sym
);
1301 // During garbage collection, this keeps sections that correspond to
1302 // symbols seen in dynamic objects.
1304 gc_mark_dyn_syms(Symbol
* sym
);
1306 // Add COUNT external symbols from the relocatable object RELOBJ to
1307 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1308 // offset in the symbol table of the first symbol, SYM_NAMES is
1309 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1310 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1311 // *DEFINED to the number of defined symbols.
1312 template<int size
, bool big_endian
>
1314 add_from_relobj(Sized_relobj
<size
, big_endian
>* relobj
,
1315 const unsigned char* syms
, size_t count
,
1316 size_t symndx_offset
, const char* sym_names
,
1317 size_t sym_name_size
,
1318 typename Sized_relobj
<size
, big_endian
>::Symbols
*,
1321 // Add one external symbol from the plugin object OBJ to the symbol table.
1322 // Returns a pointer to the resolved symbol in the symbol table.
1323 template<int size
, bool big_endian
>
1325 add_from_pluginobj(Sized_pluginobj
<size
, big_endian
>* obj
,
1326 const char* name
, const char* ver
,
1327 elfcpp::Sym
<size
, big_endian
>* sym
);
1329 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1330 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1331 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1332 // symbol version data.
1333 template<int size
, bool big_endian
>
1335 add_from_dynobj(Sized_dynobj
<size
, big_endian
>* dynobj
,
1336 const unsigned char* syms
, size_t count
,
1337 const char* sym_names
, size_t sym_name_size
,
1338 const unsigned char* versym
, size_t versym_size
,
1339 const std::vector
<const char*>*,
1340 typename Sized_relobj
<size
, big_endian
>::Symbols
*,
1343 // Define a special symbol based on an Output_data. It is a
1344 // multiple definition error if this symbol is already defined.
1346 define_in_output_data(const char* name
, const char* version
, Defined
,
1347 Output_data
*, uint64_t value
, uint64_t symsize
,
1348 elfcpp::STT type
, elfcpp::STB binding
,
1349 elfcpp::STV visibility
, unsigned char nonvis
,
1350 bool offset_is_from_end
, bool only_if_ref
);
1352 // Define a special symbol based on an Output_segment. It is a
1353 // multiple definition error if this symbol is already defined.
1355 define_in_output_segment(const char* name
, const char* version
, Defined
,
1356 Output_segment
*, uint64_t value
, uint64_t symsize
,
1357 elfcpp::STT type
, elfcpp::STB binding
,
1358 elfcpp::STV visibility
, unsigned char nonvis
,
1359 Symbol::Segment_offset_base
, bool only_if_ref
);
1361 // Define a special symbol with a constant value. It is a multiple
1362 // definition error if this symbol is already defined.
1364 define_as_constant(const char* name
, const char* version
, Defined
,
1365 uint64_t value
, uint64_t symsize
, elfcpp::STT type
,
1366 elfcpp::STB binding
, elfcpp::STV visibility
,
1367 unsigned char nonvis
, bool only_if_ref
,
1368 bool force_override
);
1370 // Define a set of symbols in output sections. If ONLY_IF_REF is
1371 // true, only define them if they are referenced.
1373 define_symbols(const Layout
*, int count
, const Define_symbol_in_section
*,
1376 // Define a set of symbols in output segments. If ONLY_IF_REF is
1377 // true, only defined them if they are referenced.
1379 define_symbols(const Layout
*, int count
, const Define_symbol_in_segment
*,
1382 // Define SYM using a COPY reloc. POSD is the Output_data where the
1383 // symbol should be defined--typically a .dyn.bss section. VALUE is
1384 // the offset within POSD.
1387 define_with_copy_reloc(Sized_symbol
<size
>* sym
, Output_data
* posd
,
1388 typename
elfcpp::Elf_types
<size
>::Elf_Addr
);
1390 // Look up a symbol.
1392 lookup(const char*, const char* version
= NULL
) const;
1394 // Return the real symbol associated with the forwarder symbol FROM.
1396 resolve_forwards(const Symbol
* from
) const;
1398 // Return the sized version of a symbol in this table.
1401 get_sized_symbol(Symbol
*) const;
1404 const Sized_symbol
<size
>*
1405 get_sized_symbol(const Symbol
*) const;
1407 // Return the count of undefined symbols seen.
1409 saw_undefined() const
1410 { return this->saw_undefined_
; }
1412 // Allocate the common symbols
1414 allocate_commons(Layout
*, Mapfile
*);
1416 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1419 add_warning(const char* name
, Object
* obj
, const std::string
& warning
)
1420 { this->warnings_
.add_warning(this, name
, obj
, warning
); }
1422 // Canonicalize a symbol name for use in the hash table.
1424 canonicalize_name(const char* name
)
1425 { return this->namepool_
.add(name
, true, NULL
); }
1427 // Possibly issue a warning for a reference to SYM at LOCATION which
1429 template<int size
, bool big_endian
>
1431 issue_warning(const Symbol
* sym
,
1432 const Relocate_info
<size
, big_endian
>* relinfo
,
1433 size_t relnum
, off_t reloffset
) const
1434 { this->warnings_
.issue_warning(sym
, relinfo
, relnum
, reloffset
); }
1436 // Check candidate_odr_violations_ to find symbols with the same name
1437 // but apparently different definitions (different source-file/line-no).
1439 detect_odr_violations(const Task
*, const char* output_file_name
) const;
1441 // Add any undefined symbols named on the command line to the symbol
1444 add_undefined_symbols_from_command_line(Layout
*);
1446 // SYM is defined using a COPY reloc. Return the dynamic object
1447 // where the original definition was found.
1449 get_copy_source(const Symbol
* sym
) const;
1451 // Set the dynamic symbol indexes. INDEX is the index of the first
1452 // global dynamic symbol. Pointers to the symbols are stored into
1453 // the vector. The names are stored into the Stringpool. This
1454 // returns an updated dynamic symbol index.
1456 set_dynsym_indexes(unsigned int index
, std::vector
<Symbol
*>*,
1457 Stringpool
*, Versions
*);
1459 // Finalize the symbol table after we have set the final addresses
1460 // of all the input sections. This sets the final symbol indexes,
1461 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1462 // index of the first global symbol. OFF is the file offset of the
1463 // global symbol table, DYNOFF is the offset of the globals in the
1464 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1465 // global dynamic symbol, and DYNCOUNT is the number of global
1466 // dynamic symbols. This records the parameters, and returns the
1467 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1470 finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
, size_t dyncount
,
1471 Stringpool
* pool
, unsigned int* plocal_symcount
);
1473 // Status code of Symbol_table::compute_final_value.
1474 enum Compute_final_value_status
1478 // Unspported symbol section.
1479 CFVS_UNSUPPORTED_SYMBOL_SECTION
,
1480 // No output section.
1481 CFVS_NO_OUTPUT_SECTION
1484 // Compute the final value of SYM and store status in location PSTATUS.
1485 // During relaxation, this may be called multiple times for a symbol to
1486 // compute its would-be final value in each relaxation pass.
1489 typename Sized_symbol
<size
>::Value_type
1490 compute_final_value(const Sized_symbol
<size
>* sym
,
1491 Compute_final_value_status
* pstatus
) const;
1493 // Return the index of the first global symbol.
1495 first_global_index() const
1496 { return this->first_global_index_
; }
1498 // Return the total number of symbols in the symbol table.
1500 output_count() const
1501 { return this->output_count_
; }
1503 // Write out the global symbols.
1505 write_globals(const Stringpool
*, const Stringpool
*,
1506 Output_symtab_xindex
*, Output_symtab_xindex
*,
1507 Output_file
*) const;
1509 // Write out a section symbol. Return the updated offset.
1511 write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1512 Output_file
*, off_t
) const;
1514 // Loop over all symbols, applying the function F to each.
1515 template<int size
, typename F
>
1517 for_all_symbols(F f
) const
1519 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1520 p
!= this->table_
.end();
1523 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1528 // Dump statistical information to stderr.
1530 print_stats() const;
1532 // Return the version script information.
1533 const Version_script_info
&
1534 version_script() const
1535 { return version_script_
; }
1538 Symbol_table(const Symbol_table
&);
1539 Symbol_table
& operator=(const Symbol_table
&);
1541 // The type of the list of common symbols.
1542 typedef std::vector
<Symbol
*> Commons_type
;
1544 // The type of the symbol hash table.
1546 typedef std::pair
<Stringpool::Key
, Stringpool::Key
> Symbol_table_key
;
1548 // The hash function. The key values are Stringpool keys.
1549 struct Symbol_table_hash
1552 operator()(const Symbol_table_key
& key
) const
1554 return key
.first
^ key
.second
;
1558 struct Symbol_table_eq
1561 operator()(const Symbol_table_key
&, const Symbol_table_key
&) const;
1564 typedef Unordered_map
<Symbol_table_key
, Symbol
*, Symbol_table_hash
,
1565 Symbol_table_eq
> Symbol_table_type
;
1567 // Make FROM a forwarder symbol to TO.
1569 make_forwarder(Symbol
* from
, Symbol
* to
);
1572 template<int size
, bool big_endian
>
1574 add_from_object(Object
*, const char* name
, Stringpool::Key name_key
,
1575 const char* version
, Stringpool::Key version_key
,
1576 bool def
, const elfcpp::Sym
<size
, big_endian
>& sym
,
1577 unsigned int st_shndx
, bool is_ordinary
,
1578 unsigned int orig_st_shndx
);
1580 // Define a default symbol.
1581 template<int size
, bool big_endian
>
1583 define_default_version(Sized_symbol
<size
>*, bool,
1584 Symbol_table_type::iterator
);
1587 template<int size
, bool big_endian
>
1589 resolve(Sized_symbol
<size
>* to
,
1590 const elfcpp::Sym
<size
, big_endian
>& sym
,
1591 unsigned int st_shndx
, bool is_ordinary
,
1592 unsigned int orig_st_shndx
,
1593 Object
*, const char* version
);
1595 template<int size
, bool big_endian
>
1597 resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
);
1599 // Record that a symbol is forced to be local by a version script or
1602 force_local(Symbol
*);
1604 // Adjust NAME and *NAME_KEY for wrapping.
1606 wrap_symbol(const char* name
, Stringpool::Key
* name_key
);
1608 // Whether we should override a symbol, based on flags in
1611 should_override(const Symbol
*, unsigned int, Defined
, Object
*, bool*, bool*);
1613 // Report a problem in symbol resolution.
1615 report_resolve_problem(bool is_error
, const char* msg
, const Symbol
* to
,
1616 Defined
, Object
* object
);
1618 // Override a symbol.
1619 template<int size
, bool big_endian
>
1621 override(Sized_symbol
<size
>* tosym
,
1622 const elfcpp::Sym
<size
, big_endian
>& fromsym
,
1623 unsigned int st_shndx
, bool is_ordinary
,
1624 Object
* object
, const char* version
);
1626 // Whether we should override a symbol with a special symbol which
1627 // is automatically defined by the linker.
1629 should_override_with_special(const Symbol
*, Defined
);
1631 // Override a symbol with a special symbol.
1634 override_with_special(Sized_symbol
<size
>* tosym
,
1635 const Sized_symbol
<size
>* fromsym
);
1637 // Record all weak alias sets for a dynamic object.
1640 record_weak_aliases(std::vector
<Sized_symbol
<size
>*>*);
1642 // Define a special symbol.
1643 template<int size
, bool big_endian
>
1645 define_special_symbol(const char** pname
, const char** pversion
,
1646 bool only_if_ref
, Sized_symbol
<size
>** poldsym
,
1647 bool* resolve_oldsym
);
1649 // Define a symbol in an Output_data, sized version.
1652 do_define_in_output_data(const char* name
, const char* version
, Defined
,
1654 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1655 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1656 elfcpp::STT type
, elfcpp::STB binding
,
1657 elfcpp::STV visibility
, unsigned char nonvis
,
1658 bool offset_is_from_end
, bool only_if_ref
);
1660 // Define a symbol in an Output_segment, sized version.
1663 do_define_in_output_segment(
1664 const char* name
, const char* version
, Defined
, Output_segment
* os
,
1665 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1666 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1667 elfcpp::STT type
, elfcpp::STB binding
,
1668 elfcpp::STV visibility
, unsigned char nonvis
,
1669 Symbol::Segment_offset_base offset_base
, bool only_if_ref
);
1671 // Define a symbol as a constant, sized version.
1674 do_define_as_constant(
1675 const char* name
, const char* version
, Defined
,
1676 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1677 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1678 elfcpp::STT type
, elfcpp::STB binding
,
1679 elfcpp::STV visibility
, unsigned char nonvis
,
1680 bool only_if_ref
, bool force_override
);
1682 // Add any undefined symbols named on the command line to the symbol
1683 // table, sized version.
1686 do_add_undefined_symbols_from_command_line(Layout
*);
1688 // Add one undefined symbol.
1691 add_undefined_symbol_from_command_line(const char* name
);
1693 // Types of common symbols.
1695 enum Commons_section_type
1703 // Allocate the common symbols, sized version.
1706 do_allocate_commons(Layout
*, Mapfile
*, Sort_commons_order
);
1708 // Allocate the common symbols from one list.
1711 do_allocate_commons_list(Layout
*, Commons_section_type
, Commons_type
*,
1712 Mapfile
*, Sort_commons_order
);
1714 // Implement detect_odr_violations.
1715 template<int size
, bool big_endian
>
1717 sized_detect_odr_violations() const;
1719 // Finalize symbols specialized for size.
1722 sized_finalize(off_t
, Stringpool
*, unsigned int*);
1724 // Finalize a symbol. Return whether it should be added to the
1728 sized_finalize_symbol(Symbol
*);
1730 // Add a symbol the final symtab by setting its index.
1733 add_to_final_symtab(Symbol
*, Stringpool
*, unsigned int* pindex
, off_t
* poff
);
1735 // Write globals specialized for size and endianness.
1736 template<int size
, bool big_endian
>
1738 sized_write_globals(const Stringpool
*, const Stringpool
*,
1739 Output_symtab_xindex
*, Output_symtab_xindex
*,
1740 Output_file
*) const;
1742 // Write out a symbol to P.
1743 template<int size
, bool big_endian
>
1745 sized_write_symbol(Sized_symbol
<size
>*,
1746 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1747 unsigned int shndx
, elfcpp::STB
,
1748 const Stringpool
*, unsigned char* p
) const;
1750 // Possibly warn about an undefined symbol from a dynamic object.
1752 warn_about_undefined_dynobj_symbol(Symbol
*) const;
1754 // Write out a section symbol, specialized for size and endianness.
1755 template<int size
, bool big_endian
>
1757 sized_write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1758 Output_file
*, off_t
) const;
1760 // The type of the list of symbols which have been forced local.
1761 typedef std::vector
<Symbol
*> Forced_locals
;
1763 // A map from symbols with COPY relocs to the dynamic objects where
1764 // they are defined.
1765 typedef Unordered_map
<const Symbol
*, Dynobj
*> Copied_symbol_dynobjs
;
1767 // A map from symbol name (as a pointer into the namepool) to all
1768 // the locations the symbols is (weakly) defined (and certain other
1769 // conditions are met). This map will be used later to detect
1770 // possible One Definition Rule (ODR) violations.
1771 struct Symbol_location
1773 Object
* object
; // Object where the symbol is defined.
1774 unsigned int shndx
; // Section-in-object where the symbol is defined.
1775 off_t offset
; // Offset-in-section where the symbol is defined.
1776 bool operator==(const Symbol_location
& that
) const
1778 return (this->object
== that
.object
1779 && this->shndx
== that
.shndx
1780 && this->offset
== that
.offset
);
1784 struct Symbol_location_hash
1786 size_t operator()(const Symbol_location
& loc
) const
1787 { return reinterpret_cast<uintptr_t>(loc
.object
) ^ loc
.offset
^ loc
.shndx
; }
1790 typedef Unordered_map
<const char*,
1791 Unordered_set
<Symbol_location
, Symbol_location_hash
> >
1794 // We increment this every time we see a new undefined symbol, for
1795 // use in archive groups.
1796 size_t saw_undefined_
;
1797 // The index of the first global symbol in the output file.
1798 unsigned int first_global_index_
;
1799 // The file offset within the output symtab section where we should
1802 // The number of global symbols we want to write out.
1803 unsigned int output_count_
;
1804 // The file offset of the global dynamic symbols, or 0 if none.
1805 off_t dynamic_offset_
;
1806 // The index of the first global dynamic symbol.
1807 unsigned int first_dynamic_global_index_
;
1808 // The number of global dynamic symbols, or 0 if none.
1809 unsigned int dynamic_count_
;
1810 // The symbol hash table.
1811 Symbol_table_type table_
;
1812 // A pool of symbol names. This is used for all global symbols.
1813 // Entries in the hash table point into this pool.
1814 Stringpool namepool_
;
1815 // Forwarding symbols.
1816 Unordered_map
<const Symbol
*, Symbol
*> forwarders_
;
1817 // Weak aliases. A symbol in this list points to the next alias.
1818 // The aliases point to each other in a circular list.
1819 Unordered_map
<Symbol
*, Symbol
*> weak_aliases_
;
1820 // We don't expect there to be very many common symbols, so we keep
1821 // a list of them. When we find a common symbol we add it to this
1822 // list. It is possible that by the time we process the list the
1823 // symbol is no longer a common symbol. It may also have become a
1825 Commons_type commons_
;
1826 // This is like the commons_ field, except that it holds TLS common
1828 Commons_type tls_commons_
;
1829 // This is for small common symbols.
1830 Commons_type small_commons_
;
1831 // This is for large common symbols.
1832 Commons_type large_commons_
;
1833 // A list of symbols which have been forced to be local. We don't
1834 // expect there to be very many of them, so we keep a list of them
1835 // rather than walking the whole table to find them.
1836 Forced_locals forced_locals_
;
1837 // Manage symbol warnings.
1839 // Manage potential One Definition Rule (ODR) violations.
1840 Odr_map candidate_odr_violations_
;
1842 // When we emit a COPY reloc for a symbol, we define it in an
1843 // Output_data. When it's time to emit version information for it,
1844 // we need to know the dynamic object in which we found the original
1845 // definition. This maps symbols with COPY relocs to the dynamic
1846 // object where they were defined.
1847 Copied_symbol_dynobjs copied_symbol_dynobjs_
;
1848 // Information parsed from the version script, if any.
1849 const Version_script_info
& version_script_
;
1850 Garbage_collection
* gc_
;
1854 // We inline get_sized_symbol for efficiency.
1858 Symbol_table::get_sized_symbol(Symbol
* sym
) const
1860 gold_assert(size
== parameters
->target().get_size());
1861 return static_cast<Sized_symbol
<size
>*>(sym
);
1865 const Sized_symbol
<size
>*
1866 Symbol_table::get_sized_symbol(const Symbol
* sym
) const
1868 gold_assert(size
== parameters
->target().get_size());
1869 return static_cast<const Sized_symbol
<size
>*>(sym
);
1872 } // End namespace gold.
1874 #endif // !defined(GOLD_SYMTAB_H)