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) && parameters->options().shared()))
663 // A reference to any PLT entry in a non-position-independent executable
664 // does not need a dynamic relocation.
665 if (!parameters->options().output_is_position_independent()
666 && this->has_plt_offset())
669 // A reference to a symbol defined in a dynamic object or to a
670 // symbol that is preemptible will need a dynamic relocation.
671 if (this->is_from_dynobj()
672 || this->is_undefined()
673 || this->is_preemptible())
676 // For all other cases, return FALSE.
680 // Whether we should use the PLT offset associated with a symbol for
681 // a relocation. IS_NON_PIC_REFERENCE is true if this is a non-PIC
682 // reloc--the same set of relocs for which we would pass NON_PIC_REF
683 // to the needs_dynamic_reloc function.
686 use_plt_offset(bool is_non_pic_reference) const
688 // If the symbol doesn't have a PLT offset, then naturally we
689 // don't want to use it.
690 if (!this->has_plt_offset())
693 // For a STT_GNU_IFUNC symbol we always have to use the PLT entry.
694 if (this->type() == elfcpp::STT_GNU_IFUNC)
697 // If we are going to generate a dynamic relocation, then we will
698 // wind up using that, so no need to use the PLT entry.
699 if (this->needs_dynamic_reloc(FUNCTION_CALL
700 | (is_non_pic_reference
705 // If the symbol is from a dynamic object, we need to use the PLT
707 if (this->is_from_dynobj())
710 // If we are generating a shared object, and this symbol is
711 // undefined or preemptible, we need to use the PLT entry.
712 if (parameters->options().shared()
713 && (this->is_undefined() || this->is_preemptible()))
716 // If this is a weak undefined symbol, we need to use the PLT
717 // entry; the symbol may be defined by a library loaded at
719 if (this->is_weak_undefined())
722 // Otherwise we can use the regular definition.
726 // Given a direct absolute static relocation against
727 // the global symbol, where a dynamic relocation is needed, this
728 // function returns whether a relative dynamic relocation can be used.
729 // The caller must determine separately whether the static relocation
730 // is compatible with a relative relocation.
733 can_use_relative_reloc(bool is_function_call) const
735 // A function call that can branch to a local PLT entry can
736 // use a RELATIVE relocation.
737 if (is_function_call && this->has_plt_offset())
740 // A reference to a symbol defined in a dynamic object or to a
741 // symbol that is preemptible can not use a RELATIVE relocaiton.
742 if (this->is_from_dynobj()
743 || this->is_undefined()
744 || this->is_preemptible())
747 // For all other cases, return TRUE.
751 // Return the output section where this symbol is defined. Return
752 // NULL if the symbol has an absolute value.
754 output_section() const;
756 // Set the symbol's output section. This is used for symbols
757 // defined in scripts. This should only be called after the symbol
758 // table has been finalized.
760 set_output_section(Output_section*);
762 // Return whether there should be a warning for references to this
766 { return this->has_warning_; }
768 // Mark this symbol as having a warning.
771 { this->has_warning_ = true; }
773 // Return whether this symbol is defined by a COPY reloc from a
776 is_copied_from_dynobj() const
777 { return this->is_copied_from_dynobj_; }
779 // Mark this symbol as defined by a COPY reloc.
781 set_is_copied_from_dynobj()
782 { this->is_copied_from_dynobj_ = true; }
784 // Return whether this symbol is forced to visibility STB_LOCAL
785 // by a "local:" entry in a version script.
787 is_forced_local() const
788 { return this->is_forced_local_; }
790 // Mark this symbol as forced to STB_LOCAL visibility.
792 set_is_forced_local()
793 { this->is_forced_local_ = true; }
795 // Return true if this may need a COPY relocation.
796 // References from an executable object to non-function symbols
797 // defined in a dynamic object may need a COPY relocation.
799 may_need_copy_reloc() const
801 return (!parameters->options().shared()
802 && parameters->options().copyreloc()
803 && this->is_from_dynobj()
804 && !this->is_func());
808 // Instances of this class should always be created at a specific
811 { memset(this, 0, sizeof *this); }
813 // Initialize the general fields.
815 init_fields(const char* name, const char* version,
816 elfcpp::STT type, elfcpp::STB binding,
817 elfcpp::STV visibility, unsigned char nonvis);
819 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
820 // section index, IS_ORDINARY is whether it is a normal section
821 // index rather than a special code.
822 template<int size, bool big_endian>
824 init_base_object(const char* name, const char* version, Object* object,
825 const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
828 // Initialize fields for an Output_data.
830 init_base_output_data(const char* name, const char* version, Output_data*,
831 elfcpp::STT, elfcpp::STB, elfcpp::STV,
832 unsigned char nonvis, bool offset_is_from_end);
834 // Initialize fields for an Output_segment.
836 init_base_output_segment(const char* name, const char* version,
837 Output_segment* os, elfcpp::STT type,
838 elfcpp::STB binding, elfcpp::STV visibility,
839 unsigned char nonvis,
840 Segment_offset_base offset_base);
842 // Initialize fields for a constant.
844 init_base_constant(const char* name, const char* version, elfcpp::STT type,
845 elfcpp::STB binding, elfcpp::STV visibility,
846 unsigned char nonvis);
848 // Initialize fields for an undefined symbol.
850 init_base_undefined(const char* name, const char* version, elfcpp::STT type,
851 elfcpp::STB binding, elfcpp::STV visibility,
852 unsigned char nonvis);
854 // Override existing symbol.
855 template<int size, bool big_endian>
857 override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
858 bool is_ordinary, Object* object, const char* version);
860 // Override existing symbol with a special symbol.
862 override_base_with_special(const Symbol* from);
864 // Override symbol version.
866 override_version(const char* version);
868 // Allocate a common symbol by giving it a location in the output
871 allocate_base_common(Output_data*);
874 Symbol(const Symbol&);
875 Symbol& operator=(const Symbol&);
877 // Symbol name (expected to point into a Stringpool).
879 // Symbol version (expected to point into a Stringpool). This may
881 const char* version_;
885 // This struct is used if SOURCE_ == FROM_OBJECT.
888 // Object in which symbol is defined, or in which it was first
891 // Section number in object_ in which symbol is defined.
895 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
898 // Output_data in which symbol is defined. Before
899 // Layout::finalize the symbol's value is an offset within the
901 Output_data* output_data;
902 // True if the offset is from the end, false if the offset is
903 // from the beginning.
904 bool offset_is_from_end;
907 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
910 // Output_segment in which the symbol is defined. Before
911 // Layout::finalize the symbol's value is an offset.
912 Output_segment* output_segment;
913 // The base to use for the offset before Layout::finalize.
914 Segment_offset_base offset_base;
918 // The index of this symbol in the output file. If the symbol is
919 // not going into the output file, this value is -1U. This field
920 // starts as always holding zero. It is set to a non-zero value by
921 // Symbol_table::finalize.
922 unsigned int symtab_index_;
924 // The index of this symbol in the dynamic symbol table. If the
925 // symbol is not going into the dynamic symbol table, this value is
926 // -1U. This field starts as always holding zero. It is set to a
927 // non-zero value during Layout::finalize.
928 unsigned int dynsym_index_;
930 // The GOT section entries for this symbol. A symbol may have more
931 // than one GOT offset (e.g., when mixing modules compiled with two
932 // different TLS models), but will usually have at most one.
933 Got_offset_list got_offsets_;
935 // If this symbol has an entry in the PLT section, then this is the
936 // offset from the start of the PLT section. This is -1U if there
938 unsigned int plt_offset_;
940 // Symbol type (bits 0 to 3).
941 elfcpp::STT type_ : 4;
942 // Symbol binding (bits 4 to 7).
943 elfcpp::STB binding_ : 4;
944 // Symbol visibility (bits 8 to 9).
945 elfcpp::STV visibility_ : 2;
946 // Rest of symbol st_other field (bits 10 to 15).
947 unsigned int nonvis_ : 6;
948 // The type of symbol (bits 16 to 18).
950 // True if this is the default version of the symbol (bit 19).
952 // True if this symbol really forwards to another symbol. This is
953 // used when we discover after the fact that two different entries
954 // in the hash table really refer to the same symbol. This will
955 // never be set for a symbol found in the hash table, but may be set
956 // for a symbol found in the list of symbols attached to an Object.
957 // It forwards to the symbol found in the forwarders_ map of
958 // Symbol_table (bit 20).
959 bool is_forwarder_ : 1;
960 // True if the symbol has an alias in the weak_aliases table in
961 // Symbol_table (bit 21).
963 // True if this symbol needs to be in the dynamic symbol table (bit
965 bool needs_dynsym_entry_ : 1;
966 // True if we've seen this symbol in a regular object (bit 23).
968 // True if we've seen this symbol in a dynamic object (bit 24).
970 // True if this is a dynamic symbol which needs a special value in
971 // the dynamic symbol table (bit 25).
972 bool needs_dynsym_value_ : 1;
973 // True if there is a warning for this symbol (bit 26).
974 bool has_warning_ : 1;
975 // True if we are using a COPY reloc for this symbol, so that the
976 // real definition lives in a dynamic object (bit 27).
977 bool is_copied_from_dynobj_ : 1;
978 // True if this symbol was forced to local visibility by a version
980 bool is_forced_local_ : 1;
981 // True if the field u_.from_object.shndx is an ordinary section
982 // index, not one of the special codes from SHN_LORESERVE to
983 // SHN_HIRESERVE (bit 29).
984 bool is_ordinary_shndx_ : 1;
985 // True if we've seen this symbol in a real ELF object (bit 30).
986 bool in_real_elf_ : 1;
987 // True if this symbol is defined in a section which was discarded
989 bool is_defined_in_discarded_section_ : 1;
990 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
991 bool undef_binding_set_ : 1;
992 // True if this symbol was a weak undef resolved by a dynamic def
994 bool undef_binding_weak_ : 1;
997 // The parts of a symbol which are size specific. Using a template
998 // derived class like this helps us use less space on a 32-bit system.
1001 class Sized_symbol : public Symbol
1004 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type;
1005 typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type;
1010 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
1011 // section index, IS_ORDINARY is whether it is a normal section
1012 // index rather than a special code.
1013 template<bool big_endian>
1015 init_object(const char* name, const char* version, Object* object,
1016 const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
1019 // Initialize fields for an Output_data.
1021 init_output_data(const char* name, const char* version, Output_data*,
1022 Value_type value, Size_type symsize, elfcpp::STT,
1023 elfcpp::STB, elfcpp::STV, unsigned char nonvis,
1024 bool offset_is_from_end);
1026 // Initialize fields for an Output_segment.
1028 init_output_segment(const char* name, const char* version, Output_segment*,
1029 Value_type value, Size_type symsize, elfcpp::STT,
1030 elfcpp::STB, elfcpp::STV, unsigned char nonvis,
1031 Segment_offset_base offset_base);
1033 // Initialize fields for a constant.
1035 init_constant(const char* name, const char* version, Value_type value,
1036 Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV,
1037 unsigned char nonvis);
1039 // Initialize fields for an undefined symbol.
1041 init_undefined(const char* name, const char* version, elfcpp::STT,
1042 elfcpp::STB, elfcpp::STV, unsigned char nonvis);
1044 // Override existing symbol.
1045 template<bool big_endian>
1047 override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
1048 bool is_ordinary, Object* object, const char* version);
1050 // Override existing symbol with a special symbol.
1052 override_with_special(const Sized_symbol<size>*);
1054 // Return the symbol's value.
1057 { return this->value_; }
1059 // Return the symbol's size (we can't call this 'size' because that
1060 // is a template parameter).
1063 { return this->symsize_; }
1065 // Set the symbol size. This is used when resolving common symbols.
1067 set_symsize(Size_type symsize)
1068 { this->symsize_ = symsize; }
1070 // Set the symbol value. This is called when we store the final
1071 // values of the symbols into the symbol table.
1073 set_value(Value_type value)
1074 { this->value_ = value; }
1076 // Allocate a common symbol by giving it a location in the output
1079 allocate_common(Output_data*, Value_type value);
1082 Sized_symbol(const Sized_symbol&);
1083 Sized_symbol& operator=(const Sized_symbol&);
1085 // Symbol value. Before Layout::finalize this is the offset in the
1086 // input section. This is set to the final value during
1087 // Layout::finalize.
1093 // A struct describing a symbol defined by the linker, where the value
1094 // of the symbol is defined based on an output section. This is used
1095 // for symbols defined by the linker, like "_init_array_start".
1097 struct Define_symbol_in_section
1101 // The name of the output section with which this symbol should be
1102 // associated. If there is no output section with that name, the
1103 // symbol will be defined as zero.
1104 const char* output_section;
1105 // The offset of the symbol within the output section. This is an
1106 // offset from the start of the output section, unless start_at_end
1107 // is true, in which case this is an offset from the end of the
1110 // The size of the symbol.
1114 // The symbol binding.
1115 elfcpp::STB binding;
1116 // The symbol visibility.
1117 elfcpp::STV visibility;
1118 // The rest of the st_other field.
1119 unsigned char nonvis;
1120 // If true, the value field is an offset from the end of the output
1122 bool offset_is_from_end;
1123 // If true, this symbol is defined only if we see a reference to it.
1127 // A struct describing a symbol defined by the linker, where the value
1128 // of the symbol is defined based on a segment. This is used for
1129 // symbols defined by the linker, like "_end". We describe the
1130 // segment with which the symbol should be associated by its
1131 // characteristics. If no segment meets these characteristics, the
1132 // symbol will be defined as zero. If there is more than one segment
1133 // which meets these characteristics, we will use the first one.
1135 struct Define_symbol_in_segment
1139 // The segment type where the symbol should be defined, typically
1141 elfcpp::PT segment_type;
1142 // Bitmask of segment flags which must be set.
1143 elfcpp::PF segment_flags_set;
1144 // Bitmask of segment flags which must be clear.
1145 elfcpp::PF segment_flags_clear;
1146 // The offset of the symbol within the segment. The offset is
1147 // calculated from the position set by offset_base.
1149 // The size of the symbol.
1153 // The symbol binding.
1154 elfcpp::STB binding;
1155 // The symbol visibility.
1156 elfcpp::STV visibility;
1157 // The rest of the st_other field.
1158 unsigned char nonvis;
1159 // The base from which we compute the offset.
1160 Symbol::Segment_offset_base offset_base;
1161 // If true, this symbol is defined only if we see a reference to it.
1165 // This class manages warnings. Warnings are a GNU extension. When
1166 // we see a section named .gnu.warning.SYM in an object file, and if
1167 // we wind using the definition of SYM from that object file, then we
1168 // will issue a warning for any relocation against SYM from a
1169 // different object file. The text of the warning is the contents of
1170 // the section. This is not precisely the definition used by the old
1171 // GNU linker; the old GNU linker treated an occurrence of
1172 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1173 // would trigger a warning on any reference. However, it was
1174 // inconsistent in that a warning in a dynamic object only triggered
1175 // if there was no definition in a regular object. This linker is
1176 // different in that we only issue a warning if we use the symbol
1177 // definition from the same object file as the warning section.
1186 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1189 add_warning(Symbol_table* symtab, const char* name, Object* obj,
1190 const std::string& warning);
1192 // For each symbol for which we should give a warning, make a note
1195 note_warnings(Symbol_table* symtab);
1197 // Issue a warning for a reference to SYM at RELINFO's location.
1198 template<int size, bool big_endian>
1200 issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*,
1201 size_t relnum, off_t reloffset) const;
1204 Warnings(const Warnings&);
1205 Warnings& operator=(const Warnings&);
1207 // What we need to know to get the warning text.
1208 struct Warning_location
1210 // The object the warning is in.
1212 // The warning text.
1216 : object(NULL), text()
1220 set(Object* o, const std::string& t)
1227 // A mapping from warning symbol names (canonicalized in
1228 // Symbol_table's namepool_ field) to warning information.
1229 typedef Unordered_map<const char*, Warning_location> Warning_table;
1231 Warning_table warnings_;
1234 // The main linker symbol table.
1239 // The different places where a symbol definition can come from.
1242 // Defined in an object file--the normal case.
1244 // Defined for a COPY reloc.
1246 // Defined on the command line using --defsym.
1248 // Defined (so to speak) on the command line using -u.
1250 // Defined in a linker script.
1252 // Predefined by the linker.
1256 // The order in which we sort common symbols.
1257 enum Sort_commons_order
1259 SORT_COMMONS_BY_SIZE_DESCENDING,
1260 SORT_COMMONS_BY_ALIGNMENT_DESCENDING,
1261 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1264 // COUNT is an estimate of how many symbosl will be inserted in the
1265 // symbol table. It's ok to put 0 if you don't know; a correct
1266 // guess will just save some CPU by reducing hashtable resizes.
1267 Symbol_table(unsigned int count, const Version_script_info& version_script);
1273 { this->icf_ = icf;}
1277 { return this->icf_; }
1279 // Returns true if ICF determined that this is a duplicate section.
1281 is_section_folded(Object* obj, unsigned int shndx) const;
1284 set_gc(Garbage_collection* gc)
1289 { return this->gc_; }
1291 // During garbage collection, this keeps undefined symbols.
1293 gc_mark_undef_symbols(Layout*);
1295 // During garbage collection, this ensures externally visible symbols
1296 // are not treated as garbage while building shared objects.
1298 gc_mark_symbol_for_shlib(Symbol* sym);
1300 // During garbage collection, this keeps sections that correspond to
1301 // symbols seen in dynamic objects.
1303 gc_mark_dyn_syms(Symbol* sym);
1305 // Add COUNT external symbols from the relocatable object RELOBJ to
1306 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1307 // offset in the symbol table of the first symbol, SYM_NAMES is
1308 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1309 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1310 // *DEFINED to the number of defined symbols.
1311 template<int size, bool big_endian>
1313 add_from_relobj(Sized_relobj<size, big_endian>* relobj,
1314 const unsigned char* syms, size_t count,
1315 size_t symndx_offset, const char* sym_names,
1316 size_t sym_name_size,
1317 typename Sized_relobj<size, big_endian>::Symbols*,
1320 // Add one external symbol from the plugin object OBJ to the symbol table.
1321 // Returns a pointer to the resolved symbol in the symbol table.
1322 template<int size, bool big_endian>
1324 add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj,
1325 const char* name, const char* ver,
1326 elfcpp::Sym<size, big_endian>* sym);
1328 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1329 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1330 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1331 // symbol version data.
1332 template<int size, bool big_endian>
1334 add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj,
1335 const unsigned char* syms, size_t count,
1336 const char* sym_names, size_t sym_name_size,
1337 const unsigned char* versym, size_t versym_size,
1338 const std::vector<const char*>*,
1339 typename Sized_relobj<size, big_endian>::Symbols*,
1342 // Define a special symbol based on an Output_data. It is a
1343 // multiple definition error if this symbol is already defined.
1345 define_in_output_data(const char* name, const char* version, Defined,
1346 Output_data*, uint64_t value, uint64_t symsize,
1347 elfcpp::STT type, elfcpp::STB binding,
1348 elfcpp::STV visibility, unsigned char nonvis,
1349 bool offset_is_from_end, bool only_if_ref);
1351 // Define a special symbol based on an Output_segment. It is a
1352 // multiple definition error if this symbol is already defined.
1354 define_in_output_segment(const char* name, const char* version, Defined,
1355 Output_segment*, uint64_t value, uint64_t symsize,
1356 elfcpp::STT type, elfcpp::STB binding,
1357 elfcpp::STV visibility, unsigned char nonvis,
1358 Symbol::Segment_offset_base, bool only_if_ref);
1360 // Define a special symbol with a constant value. It is a multiple
1361 // definition error if this symbol is already defined.
1363 define_as_constant(const char* name, const char* version, Defined,
1364 uint64_t value, uint64_t symsize, elfcpp::STT type,
1365 elfcpp::STB binding, elfcpp::STV visibility,
1366 unsigned char nonvis, bool only_if_ref,
1367 bool force_override);
1369 // Define a set of symbols in output sections. If ONLY_IF_REF is
1370 // true, only define them if they are referenced.
1372 define_symbols(const Layout*, int count, const Define_symbol_in_section*,
1375 // Define a set of symbols in output segments. If ONLY_IF_REF is
1376 // true, only defined them if they are referenced.
1378 define_symbols(const Layout*, int count, const Define_symbol_in_segment*,
1381 // Define SYM using a COPY reloc. POSD is the Output_data where the
1382 // symbol should be defined--typically a .dyn.bss section. VALUE is
1383 // the offset within POSD.
1386 define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd,
1387 typename elfcpp::Elf_types<size>::Elf_Addr);
1389 // Look up a symbol.
1391 lookup(const char*, const char* version = NULL) const;
1393 // Return the real symbol associated with the forwarder symbol FROM.
1395 resolve_forwards(const Symbol* from) const;
1397 // Return the sized version of a symbol in this table.
1400 get_sized_symbol(Symbol*) const;
1403 const Sized_symbol<size>*
1404 get_sized_symbol(const Symbol*) const;
1406 // Return the count of undefined symbols seen.
1408 saw_undefined() const
1409 { return this->saw_undefined_; }
1411 // Allocate the common symbols
1413 allocate_commons(Layout*, Mapfile*);
1415 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1418 add_warning(const char* name, Object* obj, const std::string& warning)
1419 { this->warnings_.add_warning(this, name, obj, warning); }
1421 // Canonicalize a symbol name for use in the hash table.
1423 canonicalize_name(const char* name)
1424 { return this->namepool_.add(name, true, NULL); }
1426 // Possibly issue a warning for a reference to SYM at LOCATION which
1428 template<int size, bool big_endian>
1430 issue_warning(const Symbol* sym,
1431 const Relocate_info<size, big_endian>* relinfo,
1432 size_t relnum, off_t reloffset) const
1433 { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); }
1435 // Check candidate_odr_violations_ to find symbols with the same name
1436 // but apparently different definitions (different source-file/line-no).
1438 detect_odr_violations(const Task*, const char* output_file_name) const;
1440 // Add any undefined symbols named on the command line to the symbol
1443 add_undefined_symbols_from_command_line(Layout*);
1445 // SYM is defined using a COPY reloc. Return the dynamic object
1446 // where the original definition was found.
1448 get_copy_source(const Symbol* sym) const;
1450 // Set the dynamic symbol indexes. INDEX is the index of the first
1451 // global dynamic symbol. Pointers to the symbols are stored into
1452 // the vector. The names are stored into the Stringpool. This
1453 // returns an updated dynamic symbol index.
1455 set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*,
1456 Stringpool*, Versions*);
1458 // Finalize the symbol table after we have set the final addresses
1459 // of all the input sections. This sets the final symbol indexes,
1460 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1461 // index of the first global symbol. OFF is the file offset of the
1462 // global symbol table, DYNOFF is the offset of the globals in the
1463 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1464 // global dynamic symbol, and DYNCOUNT is the number of global
1465 // dynamic symbols. This records the parameters, and returns the
1466 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1469 finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount,
1470 Stringpool* pool, unsigned int* plocal_symcount);
1472 // Status code of Symbol_table::compute_final_value.
1473 enum Compute_final_value_status
1477 // Unspported symbol section.
1478 CFVS_UNSUPPORTED_SYMBOL_SECTION,
1479 // No output section.
1480 CFVS_NO_OUTPUT_SECTION
1483 // Compute the final value of SYM and store status in location PSTATUS.
1484 // During relaxation, this may be called multiple times for a symbol to
1485 // compute its would-be final value in each relaxation pass.
1488 typename Sized_symbol<size>::Value_type
1489 compute_final_value(const Sized_symbol<size>* sym,
1490 Compute_final_value_status* pstatus) const;
1492 // Return the index of the first global symbol.
1494 first_global_index() const
1495 { return this->first_global_index_; }
1497 // Return the total number of symbols in the symbol table.
1499 output_count() const
1500 { return this->output_count_; }
1502 // Write out the global symbols.
1504 write_globals(const Stringpool*, const Stringpool*,
1505 Output_symtab_xindex*, Output_symtab_xindex*,
1506 Output_file*) const;
1508 // Write out a section symbol. Return the updated offset.
1510 write_section_symbol(const Output_section*, Output_symtab_xindex*,
1511 Output_file*, off_t) const;
1513 // Loop over all symbols, applying the function F to each.
1514 template<int size, typename F>
1516 for_all_symbols(F f) const
1518 for (Symbol_table_type::const_iterator p = this->table_.begin();
1519 p != this->table_.end();
1522 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1527 // Dump statistical information to stderr.
1529 print_stats() const;
1531 // Return the version script information.
1532 const Version_script_info&
1533 version_script() const
1534 { return version_script_; }
1537 Symbol_table(const Symbol_table&);
1538 Symbol_table& operator=(const Symbol_table&);
1540 // The type of the list of common symbols.
1541 typedef std::vector<Symbol*> Commons_type;
1543 // The type of the symbol hash table.
1545 typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
1547 struct Symbol_table_hash
1550 operator()(const Symbol_table_key&) const;
1553 struct Symbol_table_eq
1556 operator()(const Symbol_table_key&, const Symbol_table_key&) const;
1559 typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
1560 Symbol_table_eq> Symbol_table_type;
1562 // Make FROM a forwarder symbol to TO.
1564 make_forwarder(Symbol* from, Symbol* to);
1567 template<int size, bool big_endian>
1569 add_from_object(Object*, const char* name, Stringpool::Key name_key,
1570 const char* version, Stringpool::Key version_key,
1571 bool def, const elfcpp::Sym<size, big_endian>& sym,
1572 unsigned int st_shndx, bool is_ordinary,
1573 unsigned int orig_st_shndx);
1575 // Define a default symbol.
1576 template<int size, bool big_endian>
1578 define_default_version(Sized_symbol<size>*, bool,
1579 Symbol_table_type::iterator);
1582 template<int size, bool big_endian>
1584 resolve(Sized_symbol<size>* to,
1585 const elfcpp::Sym<size, big_endian>& sym,
1586 unsigned int st_shndx, bool is_ordinary,
1587 unsigned int orig_st_shndx,
1588 Object*, const char* version);
1590 template<int size, bool big_endian>
1592 resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from);
1594 // Record that a symbol is forced to be local by a version script or
1597 force_local(Symbol*);
1599 // Adjust NAME and *NAME_KEY for wrapping.
1601 wrap_symbol(const char* name, Stringpool::Key* name_key);
1603 // Whether we should override a symbol, based on flags in
1606 should_override(const Symbol*, unsigned int, Defined, Object*, bool*, bool*);
1608 // Report a problem in symbol resolution.
1610 report_resolve_problem(bool is_error, const char* msg, const Symbol* to,
1611 Defined, Object* object);
1613 // Override a symbol.
1614 template<int size, bool big_endian>
1616 override(Sized_symbol<size>* tosym,
1617 const elfcpp::Sym<size, big_endian>& fromsym,
1618 unsigned int st_shndx, bool is_ordinary,
1619 Object* object, const char* version);
1621 // Whether we should override a symbol with a special symbol which
1622 // is automatically defined by the linker.
1624 should_override_with_special(const Symbol*, Defined);
1626 // Override a symbol with a special symbol.
1629 override_with_special(Sized_symbol<size>* tosym,
1630 const Sized_symbol<size>* fromsym);
1632 // Record all weak alias sets for a dynamic object.
1635 record_weak_aliases(std::vector<Sized_symbol<size>*>*);
1637 // Define a special symbol.
1638 template<int size, bool big_endian>
1640 define_special_symbol(const char** pname, const char** pversion,
1641 bool only_if_ref, Sized_symbol<size>** poldsym,
1642 bool* resolve_oldsym);
1644 // Define a symbol in an Output_data, sized version.
1647 do_define_in_output_data(const char* name, const char* version, Defined,
1649 typename elfcpp::Elf_types<size>::Elf_Addr value,
1650 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1651 elfcpp::STT type, elfcpp::STB binding,
1652 elfcpp::STV visibility, unsigned char nonvis,
1653 bool offset_is_from_end, bool only_if_ref);
1655 // Define a symbol in an Output_segment, sized version.
1658 do_define_in_output_segment(
1659 const char* name, const char* version, Defined, Output_segment* os,
1660 typename elfcpp::Elf_types<size>::Elf_Addr value,
1661 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1662 elfcpp::STT type, elfcpp::STB binding,
1663 elfcpp::STV visibility, unsigned char nonvis,
1664 Symbol::Segment_offset_base offset_base, bool only_if_ref);
1666 // Define a symbol as a constant, sized version.
1669 do_define_as_constant(
1670 const char* name, const char* version, Defined,
1671 typename elfcpp::Elf_types<size>::Elf_Addr value,
1672 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1673 elfcpp::STT type, elfcpp::STB binding,
1674 elfcpp::STV visibility, unsigned char nonvis,
1675 bool only_if_ref, bool force_override);
1677 // Add any undefined symbols named on the command line to the symbol
1678 // table, sized version.
1681 do_add_undefined_symbols_from_command_line(Layout*);
1683 // Add one undefined symbol.
1686 add_undefined_symbol_from_command_line(const char* name);
1688 // Types of common symbols.
1690 enum Commons_section_type
1698 // Allocate the common symbols, sized version.
1701 do_allocate_commons(Layout*, Mapfile*, Sort_commons_order);
1703 // Allocate the common symbols from one list.
1706 do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*,
1707 Mapfile*, Sort_commons_order);
1709 // Implement detect_odr_violations.
1710 template<int size, bool big_endian>
1712 sized_detect_odr_violations() const;
1714 // Finalize symbols specialized for size.
1717 sized_finalize(off_t, Stringpool*, unsigned int*);
1719 // Finalize a symbol. Return whether it should be added to the
1723 sized_finalize_symbol(Symbol*);
1725 // Add a symbol the final symtab by setting its index.
1728 add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff);
1730 // Write globals specialized for size and endianness.
1731 template<int size, bool big_endian>
1733 sized_write_globals(const Stringpool*, const Stringpool*,
1734 Output_symtab_xindex*, Output_symtab_xindex*,
1735 Output_file*) const;
1737 // Write out a symbol to P.
1738 template<int size, bool big_endian>
1740 sized_write_symbol(Sized_symbol<size>*,
1741 typename elfcpp::Elf_types<size>::Elf_Addr value,
1742 unsigned int shndx, elfcpp::STB,
1743 const Stringpool*, unsigned char* p) const;
1745 // Possibly warn about an undefined symbol from a dynamic object.
1747 warn_about_undefined_dynobj_symbol(Symbol*) const;
1749 // Write out a section symbol, specialized for size and endianness.
1750 template<int size, bool big_endian>
1752 sized_write_section_symbol(const Output_section*, Output_symtab_xindex*,
1753 Output_file*, off_t) const;
1755 // The type of the list of symbols which have been forced local.
1756 typedef std::vector<Symbol*> Forced_locals;
1758 // A map from symbols with COPY relocs to the dynamic objects where
1759 // they are defined.
1760 typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs;
1762 // A map from symbol name (as a pointer into the namepool) to all
1763 // the locations the symbols is (weakly) defined (and certain other
1764 // conditions are met). This map will be used later to detect
1765 // possible One Definition Rule (ODR) violations.
1766 struct Symbol_location
1768 Object* object; // Object where the symbol is defined.
1769 unsigned int shndx; // Section-in-object where the symbol is defined.
1770 off_t offset; // Offset-in-section where the symbol is defined.
1771 bool operator==(const Symbol_location& that) const
1773 return (this->object == that.object
1774 && this->shndx == that.shndx
1775 && this->offset == that.offset);
1779 struct Symbol_location_hash
1781 size_t operator()(const Symbol_location& loc) const
1782 { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; }
1785 typedef Unordered_map<const char*,
1786 Unordered_set<Symbol_location, Symbol_location_hash> >
1789 // We increment this every time we see a new undefined symbol, for
1790 // use in archive groups.
1791 size_t saw_undefined_;
1792 // The index of the first global symbol in the output file.
1793 unsigned int first_global_index_;
1794 // The file offset within the output symtab section where we should
1797 // The number of global symbols we want to write out.
1798 unsigned int output_count_;
1799 // The file offset of the global dynamic symbols, or 0 if none.
1800 off_t dynamic_offset_;
1801 // The index of the first global dynamic symbol.
1802 unsigned int first_dynamic_global_index_;
1803 // The number of global dynamic symbols, or 0 if none.
1804 unsigned int dynamic_count_;
1805 // The symbol hash table.
1806 Symbol_table_type table_;
1807 // A pool of symbol names. This is used for all global symbols.
1808 // Entries in the hash table point into this pool.
1809 Stringpool namepool_;
1810 // Forwarding symbols.
1811 Unordered_map<const Symbol*, Symbol*> forwarders_;
1812 // Weak aliases. A symbol in this list points to the next alias.
1813 // The aliases point to each other in a circular list.
1814 Unordered_map<Symbol*, Symbol*> weak_aliases_;
1815 // We don't expect there to be very many common symbols, so we keep
1816 // a list of them. When we find a common symbol we add it to this
1817 // list. It is possible that by the time we process the list the
1818 // symbol is no longer a common symbol. It may also have become a
1820 Commons_type commons_;
1821 // This is like the commons_ field, except that it holds TLS common
1823 Commons_type tls_commons_;
1824 // This is for small common symbols.
1825 Commons_type small_commons_;
1826 // This is for large common symbols.
1827 Commons_type large_commons_;
1828 // A list of symbols which have been forced to be local. We don't
1829 // expect there to be very many of them, so we keep a list of them
1830 // rather than walking the whole table to find them.
1831 Forced_locals forced_locals_;
1832 // Manage symbol warnings.
1834 // Manage potential One Definition Rule (ODR) violations.
1835 Odr_map candidate_odr_violations_;
1837 // When we emit a COPY reloc for a symbol, we define it in an
1838 // Output_data. When it's time to emit version information for it,
1839 // we need to know the dynamic object in which we found the original
1840 // definition. This maps symbols with COPY relocs to the dynamic
1841 // object where they were defined.
1842 Copied_symbol_dynobjs copied_symbol_dynobjs_;
1843 // Information parsed from the version script, if any.
1844 const Version_script_info& version_script_;
1845 Garbage_collection* gc_;
1849 // We inline get_sized_symbol for efficiency.
1853 Symbol_table::get_sized_symbol(Symbol* sym) const
1855 gold_assert(size == parameters->target().get_size());
1856 return static_cast<Sized_symbol<size>*>(sym);
1860 const Sized_symbol<size>*
1861 Symbol_table::get_sized_symbol(const Symbol* sym) const
1863 gold_assert(size == parameters->target().get_size());
1864 return static_cast<const Sized_symbol<size>*>(sym);
1867 } // End namespace gold.
1869 #endif // !defined(GOLD_SYMTAB_H)