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 whether this symbol has an entry in the PLT section.
414 has_plt_offset() const
415 { return this->plt_offset_ != -1U; }
417 // Return the offset into the PLT section of this symbol.
421 gold_assert(this->has_plt_offset());
422 return this->plt_offset_;
425 // Set the PLT offset of this symbol.
427 set_plt_offset(unsigned int plt_offset)
429 gold_assert(plt_offset != -1U);
430 this->plt_offset_ = plt_offset;
433 // Return whether this dynamic symbol needs a special value in the
434 // dynamic symbol table.
436 needs_dynsym_value() const
437 { return this->needs_dynsym_value_; }
439 // Set that this dynamic symbol needs a special value in the dynamic
442 set_needs_dynsym_value()
444 gold_assert(this->object()->is_dynamic());
445 this->needs_dynsym_value_ = true;
448 // Return true if the final value of this symbol is known at link
451 final_value_is_known() const;
453 // Return true if SHNDX represents a common symbol. This depends on
456 is_common_shndx(unsigned int shndx);
458 // Return whether this is a defined symbol (not undefined or
464 if (this->source_ != FROM_OBJECT)
465 return this->source_ != IS_UNDEFINED;
466 unsigned int shndx = this->shndx(&is_ordinary);
468 ? shndx != elfcpp::SHN_UNDEF
469 : !Symbol::is_common_shndx(shndx));
472 // Return true if this symbol is from a dynamic object.
474 is_from_dynobj() const
476 return this->source_ == FROM_OBJECT && this->object()->is_dynamic();
479 // Return whether this is a placeholder symbol from a plugin object.
481 is_placeholder() const
483 return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL;
486 // Return whether this is an undefined symbol.
491 return ((this->source_ == FROM_OBJECT
492 && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF
494 || this->source_ == IS_UNDEFINED);
497 // Return whether this is a weak undefined symbol.
499 is_weak_undefined() const
500 { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK; }
502 // Return whether this is an absolute symbol.
507 return ((this->source_ == FROM_OBJECT
508 && this->shndx(&is_ordinary) == elfcpp::SHN_ABS
510 || this->source_ == IS_CONSTANT);
513 // Return whether this is a common symbol.
517 if (this->source_ != FROM_OBJECT)
519 if (this->type_ == elfcpp::STT_COMMON)
522 unsigned int shndx = this->shndx(&is_ordinary);
523 return !is_ordinary && Symbol::is_common_shndx(shndx);
526 // Return whether this symbol can be seen outside this object.
528 is_externally_visible() const
530 return (this->visibility_ == elfcpp::STV_DEFAULT
531 || this->visibility_ == elfcpp::STV_PROTECTED);
534 // Return true if this symbol can be preempted by a definition in
535 // another link unit.
537 is_preemptible() const
539 // It doesn't make sense to ask whether a symbol defined in
540 // another object is preemptible.
541 gold_assert(!this->is_from_dynobj());
543 // It doesn't make sense to ask whether an undefined symbol
545 gold_assert(!this->is_undefined());
547 // If a symbol does not have default visibility, it can not be
548 // seen outside this link unit and therefore is not preemptible.
549 if (this->visibility_ != elfcpp::STV_DEFAULT)
552 // If this symbol has been forced to be a local symbol by a
553 // version script, then it is not visible outside this link unit
554 // and is not preemptible.
555 if (this->is_forced_local_)
558 // If we are not producing a shared library, then nothing is
560 if (!parameters->options().shared())
563 // If the user used -Bsymbolic, then nothing is preemptible.
564 if (parameters->options().Bsymbolic())
567 // If the user used -Bsymbolic-functions, then functions are not
568 // preemptible. We explicitly check for not being STT_OBJECT,
569 // rather than for being STT_FUNC, because that is what the GNU
571 if (this->type() != elfcpp::STT_OBJECT
572 && parameters->options().Bsymbolic_functions())
575 // Otherwise the symbol is preemptible.
579 // Return true if this symbol is a function that needs a PLT entry.
580 // If the symbol is defined in a dynamic object or if it is subject
581 // to pre-emption, we need to make a PLT entry. If we're doing a
582 // static link or a -pie link, we don't create PLT entries.
584 needs_plt_entry() const
586 // An undefined symbol from an executable does not need a PLT entry.
587 if (this->is_undefined() && !parameters->options().shared())
590 return (!parameters->doing_static_link()
591 && !parameters->options().pie()
593 && (this->is_from_dynobj()
594 || this->is_undefined()
595 || this->is_preemptible()));
598 // When determining whether a reference to a symbol needs a dynamic
599 // relocation, we need to know several things about the reference.
600 // These flags may be or'ed together.
603 // Reference to the symbol's absolute address.
605 // A non-PIC reference.
611 // Given a direct absolute or pc-relative static relocation against
612 // the global symbol, this function returns whether a dynamic relocation
616 needs_dynamic_reloc(int flags) const
618 // No dynamic relocations in a static link!
619 if (parameters->doing_static_link())
622 // A reference to an undefined symbol from an executable should be
623 // statically resolved to 0, and does not need a dynamic relocation.
624 // This matches gnu ld behavior.
625 if (this->is_undefined() && !parameters->options().shared())
628 // A reference to an absolute symbol does not need a dynamic relocation.
629 if (this->is_absolute())
632 // An absolute reference within a position-independent output file
633 // will need a dynamic relocation.
634 if ((flags & ABSOLUTE_REF)
635 && parameters->options().output_is_position_independent())
638 // A function call that can branch to a local PLT entry does not need
639 // a dynamic relocation. A non-pic pc-relative function call in a
640 // shared library cannot use a PLT entry.
641 if ((flags & FUNCTION_CALL)
642 && this->has_plt_offset()
643 && !((flags & NON_PIC_REF) && parameters->options().shared()))
646 // A reference to any PLT entry in a non-position-independent executable
647 // does not need a dynamic relocation.
648 if (!parameters->options().output_is_position_independent()
649 && this->has_plt_offset())
652 // A reference to a symbol defined in a dynamic object or to a
653 // symbol that is preemptible will need a dynamic relocation.
654 if (this->is_from_dynobj()
655 || this->is_undefined()
656 || this->is_preemptible())
659 // For all other cases, return FALSE.
663 // Whether we should use the PLT offset associated with a symbol for
664 // a relocation. IS_NON_PIC_REFERENCE is true if this is a non-PIC
665 // reloc--the same set of relocs for which we would pass NON_PIC_REF
666 // to the needs_dynamic_reloc function.
669 use_plt_offset(bool is_non_pic_reference) const
671 // If the symbol doesn't have a PLT offset, then naturally we
672 // don't want to use it.
673 if (!this->has_plt_offset())
676 // If we are going to generate a dynamic relocation, then we will
677 // wind up using that, so no need to use the PLT entry.
678 if (this->needs_dynamic_reloc(FUNCTION_CALL
679 | (is_non_pic_reference
684 // If the symbol is from a dynamic object, we need to use the PLT
686 if (this->is_from_dynobj())
689 // If we are generating a shared object, and this symbol is
690 // undefined or preemptible, we need to use the PLT entry.
691 if (parameters->options().shared()
692 && (this->is_undefined() || this->is_preemptible()))
695 // If this is a weak undefined symbol, we need to use the PLT
696 // entry; the symbol may be defined by a library loaded at
698 if (this->is_weak_undefined())
701 // Otherwise we can use the regular definition.
705 // Given a direct absolute static relocation against
706 // the global symbol, where a dynamic relocation is needed, this
707 // function returns whether a relative dynamic relocation can be used.
708 // The caller must determine separately whether the static relocation
709 // is compatible with a relative relocation.
712 can_use_relative_reloc(bool is_function_call) const
714 // A function call that can branch to a local PLT entry can
715 // use a RELATIVE relocation.
716 if (is_function_call && this->has_plt_offset())
719 // A reference to a symbol defined in a dynamic object or to a
720 // symbol that is preemptible can not use a RELATIVE relocaiton.
721 if (this->is_from_dynobj()
722 || this->is_undefined()
723 || this->is_preemptible())
726 // For all other cases, return TRUE.
730 // Return the output section where this symbol is defined. Return
731 // NULL if the symbol has an absolute value.
733 output_section() const;
735 // Set the symbol's output section. This is used for symbols
736 // defined in scripts. This should only be called after the symbol
737 // table has been finalized.
739 set_output_section(Output_section*);
741 // Return whether there should be a warning for references to this
745 { return this->has_warning_; }
747 // Mark this symbol as having a warning.
750 { this->has_warning_ = true; }
752 // Return whether this symbol is defined by a COPY reloc from a
755 is_copied_from_dynobj() const
756 { return this->is_copied_from_dynobj_; }
758 // Mark this symbol as defined by a COPY reloc.
760 set_is_copied_from_dynobj()
761 { this->is_copied_from_dynobj_ = true; }
763 // Return whether this symbol is forced to visibility STB_LOCAL
764 // by a "local:" entry in a version script.
766 is_forced_local() const
767 { return this->is_forced_local_; }
769 // Mark this symbol as forced to STB_LOCAL visibility.
771 set_is_forced_local()
772 { this->is_forced_local_ = true; }
774 // Return true if this may need a COPY relocation.
775 // References from an executable object to non-function symbols
776 // defined in a dynamic object may need a COPY relocation.
778 may_need_copy_reloc() const
780 return (!parameters->options().shared()
781 && parameters->options().copyreloc()
782 && this->is_from_dynobj()
783 && !this->is_func());
787 // Instances of this class should always be created at a specific
790 { memset(this, 0, sizeof *this); }
792 // Initialize the general fields.
794 init_fields(const char* name, const char* version,
795 elfcpp::STT type, elfcpp::STB binding,
796 elfcpp::STV visibility, unsigned char nonvis);
798 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
799 // section index, IS_ORDINARY is whether it is a normal section
800 // index rather than a special code.
801 template<int size, bool big_endian>
803 init_base_object(const char *name, const char* version, Object* object,
804 const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
807 // Initialize fields for an Output_data.
809 init_base_output_data(const char* name, const char* version, Output_data*,
810 elfcpp::STT, elfcpp::STB, elfcpp::STV,
811 unsigned char nonvis, bool offset_is_from_end);
813 // Initialize fields for an Output_segment.
815 init_base_output_segment(const char* name, const char* version,
816 Output_segment* os, elfcpp::STT type,
817 elfcpp::STB binding, elfcpp::STV visibility,
818 unsigned char nonvis,
819 Segment_offset_base offset_base);
821 // Initialize fields for a constant.
823 init_base_constant(const char* name, const char* version, elfcpp::STT type,
824 elfcpp::STB binding, elfcpp::STV visibility,
825 unsigned char nonvis);
827 // Initialize fields for an undefined symbol.
829 init_base_undefined(const char* name, const char* version, elfcpp::STT type,
830 elfcpp::STB binding, elfcpp::STV visibility,
831 unsigned char nonvis);
833 // Override existing symbol.
834 template<int size, bool big_endian>
836 override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
837 bool is_ordinary, Object* object, const char* version);
839 // Override existing symbol with a special symbol.
841 override_base_with_special(const Symbol* from);
843 // Override symbol version.
845 override_version(const char* version);
847 // Allocate a common symbol by giving it a location in the output
850 allocate_base_common(Output_data*);
853 Symbol(const Symbol&);
854 Symbol& operator=(const Symbol&);
856 // Symbol name (expected to point into a Stringpool).
858 // Symbol version (expected to point into a Stringpool). This may
860 const char* version_;
864 // This struct is used if SOURCE_ == FROM_OBJECT.
867 // Object in which symbol is defined, or in which it was first
870 // Section number in object_ in which symbol is defined.
874 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
877 // Output_data in which symbol is defined. Before
878 // Layout::finalize the symbol's value is an offset within the
880 Output_data* output_data;
881 // True if the offset is from the end, false if the offset is
882 // from the beginning.
883 bool offset_is_from_end;
886 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
889 // Output_segment in which the symbol is defined. Before
890 // Layout::finalize the symbol's value is an offset.
891 Output_segment* output_segment;
892 // The base to use for the offset before Layout::finalize.
893 Segment_offset_base offset_base;
897 // The index of this symbol in the output file. If the symbol is
898 // not going into the output file, this value is -1U. This field
899 // starts as always holding zero. It is set to a non-zero value by
900 // Symbol_table::finalize.
901 unsigned int symtab_index_;
903 // The index of this symbol in the dynamic symbol table. If the
904 // symbol is not going into the dynamic symbol table, this value is
905 // -1U. This field starts as always holding zero. It is set to a
906 // non-zero value during Layout::finalize.
907 unsigned int dynsym_index_;
909 // The GOT section entries for this symbol. A symbol may have more
910 // than one GOT offset (e.g., when mixing modules compiled with two
911 // different TLS models), but will usually have at most one.
912 Got_offset_list got_offsets_;
914 // If this symbol has an entry in the PLT section, then this is the
915 // offset from the start of the PLT section. This is -1U if there
917 unsigned int plt_offset_;
919 // Symbol type (bits 0 to 3).
920 elfcpp::STT type_ : 4;
921 // Symbol binding (bits 4 to 7).
922 elfcpp::STB binding_ : 4;
923 // Symbol visibility (bits 8 to 9).
924 elfcpp::STV visibility_ : 2;
925 // Rest of symbol st_other field (bits 10 to 15).
926 unsigned int nonvis_ : 6;
927 // The type of symbol (bits 16 to 18).
929 // True if this is the default version of the symbol (bit 19).
931 // True if this symbol really forwards to another symbol. This is
932 // used when we discover after the fact that two different entries
933 // in the hash table really refer to the same symbol. This will
934 // never be set for a symbol found in the hash table, but may be set
935 // for a symbol found in the list of symbols attached to an Object.
936 // It forwards to the symbol found in the forwarders_ map of
937 // Symbol_table (bit 20).
938 bool is_forwarder_ : 1;
939 // True if the symbol has an alias in the weak_aliases table in
940 // Symbol_table (bit 21).
942 // True if this symbol needs to be in the dynamic symbol table (bit
944 bool needs_dynsym_entry_ : 1;
945 // True if we've seen this symbol in a regular object (bit 23).
947 // True if we've seen this symbol in a dynamic object (bit 24).
949 // True if this is a dynamic symbol which needs a special value in
950 // the dynamic symbol table (bit 25).
951 bool needs_dynsym_value_ : 1;
952 // True if there is a warning for this symbol (bit 26).
953 bool has_warning_ : 1;
954 // True if we are using a COPY reloc for this symbol, so that the
955 // real definition lives in a dynamic object (bit 27).
956 bool is_copied_from_dynobj_ : 1;
957 // True if this symbol was forced to local visibility by a version
959 bool is_forced_local_ : 1;
960 // True if the field u_.from_object.shndx is an ordinary section
961 // index, not one of the special codes from SHN_LORESERVE to
962 // SHN_HIRESERVE (bit 29).
963 bool is_ordinary_shndx_ : 1;
964 // True if we've seen this symbol in a real ELF object (bit 30).
965 bool in_real_elf_ : 1;
966 // True if this symbol is defined in a section which was discarded
968 bool is_defined_in_discarded_section_ : 1;
969 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
970 bool undef_binding_set_ : 1;
971 // True if this symbol was a weak undef resolved by a dynamic def
973 bool undef_binding_weak_ : 1;
976 // The parts of a symbol which are size specific. Using a template
977 // derived class like this helps us use less space on a 32-bit system.
980 class Sized_symbol : public Symbol
983 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type;
984 typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type;
989 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
990 // section index, IS_ORDINARY is whether it is a normal section
991 // index rather than a special code.
992 template<bool big_endian>
994 init_object(const char *name, const char* version, Object* object,
995 const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
998 // Initialize fields for an Output_data.
1000 init_output_data(const char* name, const char* version, Output_data*,
1001 Value_type value, Size_type symsize, elfcpp::STT,
1002 elfcpp::STB, elfcpp::STV, unsigned char nonvis,
1003 bool offset_is_from_end);
1005 // Initialize fields for an Output_segment.
1007 init_output_segment(const char* name, const char* version, Output_segment*,
1008 Value_type value, Size_type symsize, elfcpp::STT,
1009 elfcpp::STB, elfcpp::STV, unsigned char nonvis,
1010 Segment_offset_base offset_base);
1012 // Initialize fields for a constant.
1014 init_constant(const char* name, const char* version, Value_type value,
1015 Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV,
1016 unsigned char nonvis);
1018 // Initialize fields for an undefined symbol.
1020 init_undefined(const char* name, const char* version, elfcpp::STT,
1021 elfcpp::STB, elfcpp::STV, unsigned char nonvis);
1023 // Override existing symbol.
1024 template<bool big_endian>
1026 override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
1027 bool is_ordinary, Object* object, const char* version);
1029 // Override existing symbol with a special symbol.
1031 override_with_special(const Sized_symbol<size>*);
1033 // Return the symbol's value.
1036 { return this->value_; }
1038 // Return the symbol's size (we can't call this 'size' because that
1039 // is a template parameter).
1042 { return this->symsize_; }
1044 // Set the symbol size. This is used when resolving common symbols.
1046 set_symsize(Size_type symsize)
1047 { this->symsize_ = symsize; }
1049 // Set the symbol value. This is called when we store the final
1050 // values of the symbols into the symbol table.
1052 set_value(Value_type value)
1053 { this->value_ = value; }
1055 // Allocate a common symbol by giving it a location in the output
1058 allocate_common(Output_data*, Value_type value);
1061 Sized_symbol(const Sized_symbol&);
1062 Sized_symbol& operator=(const Sized_symbol&);
1064 // Symbol value. Before Layout::finalize this is the offset in the
1065 // input section. This is set to the final value during
1066 // Layout::finalize.
1072 // A struct describing a symbol defined by the linker, where the value
1073 // of the symbol is defined based on an output section. This is used
1074 // for symbols defined by the linker, like "_init_array_start".
1076 struct Define_symbol_in_section
1080 // The name of the output section with which this symbol should be
1081 // associated. If there is no output section with that name, the
1082 // symbol will be defined as zero.
1083 const char* output_section;
1084 // The offset of the symbol within the output section. This is an
1085 // offset from the start of the output section, unless start_at_end
1086 // is true, in which case this is an offset from the end of the
1089 // The size of the symbol.
1093 // The symbol binding.
1094 elfcpp::STB binding;
1095 // The symbol visibility.
1096 elfcpp::STV visibility;
1097 // The rest of the st_other field.
1098 unsigned char nonvis;
1099 // If true, the value field is an offset from the end of the output
1101 bool offset_is_from_end;
1102 // If true, this symbol is defined only if we see a reference to it.
1106 // A struct describing a symbol defined by the linker, where the value
1107 // of the symbol is defined based on a segment. This is used for
1108 // symbols defined by the linker, like "_end". We describe the
1109 // segment with which the symbol should be associated by its
1110 // characteristics. If no segment meets these characteristics, the
1111 // symbol will be defined as zero. If there is more than one segment
1112 // which meets these characteristics, we will use the first one.
1114 struct Define_symbol_in_segment
1118 // The segment type where the symbol should be defined, typically
1120 elfcpp::PT segment_type;
1121 // Bitmask of segment flags which must be set.
1122 elfcpp::PF segment_flags_set;
1123 // Bitmask of segment flags which must be clear.
1124 elfcpp::PF segment_flags_clear;
1125 // The offset of the symbol within the segment. The offset is
1126 // calculated from the position set by offset_base.
1128 // The size of the symbol.
1132 // The symbol binding.
1133 elfcpp::STB binding;
1134 // The symbol visibility.
1135 elfcpp::STV visibility;
1136 // The rest of the st_other field.
1137 unsigned char nonvis;
1138 // The base from which we compute the offset.
1139 Symbol::Segment_offset_base offset_base;
1140 // If true, this symbol is defined only if we see a reference to it.
1144 // This class manages warnings. Warnings are a GNU extension. When
1145 // we see a section named .gnu.warning.SYM in an object file, and if
1146 // we wind using the definition of SYM from that object file, then we
1147 // will issue a warning for any relocation against SYM from a
1148 // different object file. The text of the warning is the contents of
1149 // the section. This is not precisely the definition used by the old
1150 // GNU linker; the old GNU linker treated an occurrence of
1151 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1152 // would trigger a warning on any reference. However, it was
1153 // inconsistent in that a warning in a dynamic object only triggered
1154 // if there was no definition in a regular object. This linker is
1155 // different in that we only issue a warning if we use the symbol
1156 // definition from the same object file as the warning section.
1165 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1168 add_warning(Symbol_table* symtab, const char* name, Object* obj,
1169 const std::string& warning);
1171 // For each symbol for which we should give a warning, make a note
1174 note_warnings(Symbol_table* symtab);
1176 // Issue a warning for a reference to SYM at RELINFO's location.
1177 template<int size, bool big_endian>
1179 issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*,
1180 size_t relnum, off_t reloffset) const;
1183 Warnings(const Warnings&);
1184 Warnings& operator=(const Warnings&);
1186 // What we need to know to get the warning text.
1187 struct Warning_location
1189 // The object the warning is in.
1191 // The warning text.
1195 : object(NULL), text()
1199 set(Object* o, const std::string& t)
1206 // A mapping from warning symbol names (canonicalized in
1207 // Symbol_table's namepool_ field) to warning information.
1208 typedef Unordered_map<const char*, Warning_location> Warning_table;
1210 Warning_table warnings_;
1213 // The main linker symbol table.
1218 // The different places where a symbol definition can come from.
1221 // Defined in an object file--the normal case.
1223 // Defined for a COPY reloc.
1225 // Defined on the command line using --defsym.
1227 // Defined (so to speak) on the command line using -u.
1229 // Defined in a linker script.
1231 // Predefined by the linker.
1235 // The order in which we sort common symbols.
1236 enum Sort_commons_order
1238 SORT_COMMONS_BY_SIZE_DESCENDING,
1239 SORT_COMMONS_BY_ALIGNMENT_DESCENDING,
1240 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1243 // COUNT is an estimate of how many symbosl will be inserted in the
1244 // symbol table. It's ok to put 0 if you don't know; a correct
1245 // guess will just save some CPU by reducing hashtable resizes.
1246 Symbol_table(unsigned int count, const Version_script_info& version_script);
1252 { this->icf_ = icf;}
1256 { return this->icf_; }
1258 // Returns true if ICF determined that this is a duplicate section.
1260 is_section_folded(Object* obj, unsigned int shndx) const;
1263 set_gc(Garbage_collection* gc)
1268 { return this->gc_; }
1270 // During garbage collection, this keeps undefined symbols.
1272 gc_mark_undef_symbols(Layout*);
1274 // During garbage collection, this ensures externally visible symbols
1275 // are not treated as garbage while building shared objects.
1277 gc_mark_symbol_for_shlib(Symbol* sym);
1279 // During garbage collection, this keeps sections that correspond to
1280 // symbols seen in dynamic objects.
1282 gc_mark_dyn_syms(Symbol* sym);
1284 // Add COUNT external symbols from the relocatable object RELOBJ to
1285 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1286 // offset in the symbol table of the first symbol, SYM_NAMES is
1287 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1288 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1289 // *DEFINED to the number of defined symbols.
1290 template<int size, bool big_endian>
1292 add_from_relobj(Sized_relobj<size, big_endian>* relobj,
1293 const unsigned char* syms, size_t count,
1294 size_t symndx_offset, const char* sym_names,
1295 size_t sym_name_size,
1296 typename Sized_relobj<size, big_endian>::Symbols*,
1299 // Add one external symbol from the plugin object OBJ to the symbol table.
1300 // Returns a pointer to the resolved symbol in the symbol table.
1301 template<int size, bool big_endian>
1303 add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj,
1304 const char* name, const char* ver,
1305 elfcpp::Sym<size, big_endian>* sym);
1307 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1308 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1309 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1310 // symbol version data.
1311 template<int size, bool big_endian>
1313 add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj,
1314 const unsigned char* syms, size_t count,
1315 const char* sym_names, size_t sym_name_size,
1316 const unsigned char* versym, size_t versym_size,
1317 const std::vector<const char*>*,
1318 typename Sized_relobj<size, big_endian>::Symbols*,
1321 // Define a special symbol based on an Output_data. It is a
1322 // multiple definition error if this symbol is already defined.
1324 define_in_output_data(const char* name, const char* version, Defined,
1325 Output_data*, uint64_t value, uint64_t symsize,
1326 elfcpp::STT type, elfcpp::STB binding,
1327 elfcpp::STV visibility, unsigned char nonvis,
1328 bool offset_is_from_end, bool only_if_ref);
1330 // Define a special symbol based on an Output_segment. It is a
1331 // multiple definition error if this symbol is already defined.
1333 define_in_output_segment(const char* name, const char* version, Defined,
1334 Output_segment*, uint64_t value, uint64_t symsize,
1335 elfcpp::STT type, elfcpp::STB binding,
1336 elfcpp::STV visibility, unsigned char nonvis,
1337 Symbol::Segment_offset_base, bool only_if_ref);
1339 // Define a special symbol with a constant value. It is a multiple
1340 // definition error if this symbol is already defined.
1342 define_as_constant(const char* name, const char* version, Defined,
1343 uint64_t value, uint64_t symsize, elfcpp::STT type,
1344 elfcpp::STB binding, elfcpp::STV visibility,
1345 unsigned char nonvis, bool only_if_ref,
1346 bool force_override);
1348 // Define a set of symbols in output sections. If ONLY_IF_REF is
1349 // true, only define them if they are referenced.
1351 define_symbols(const Layout*, int count, const Define_symbol_in_section*,
1354 // Define a set of symbols in output segments. If ONLY_IF_REF is
1355 // true, only defined them if they are referenced.
1357 define_symbols(const Layout*, int count, const Define_symbol_in_segment*,
1360 // Define SYM using a COPY reloc. POSD is the Output_data where the
1361 // symbol should be defined--typically a .dyn.bss section. VALUE is
1362 // the offset within POSD.
1365 define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd,
1366 typename elfcpp::Elf_types<size>::Elf_Addr);
1368 // Look up a symbol.
1370 lookup(const char*, const char* version = NULL) const;
1372 // Return the real symbol associated with the forwarder symbol FROM.
1374 resolve_forwards(const Symbol* from) const;
1376 // Return the sized version of a symbol in this table.
1379 get_sized_symbol(Symbol*) const;
1382 const Sized_symbol<size>*
1383 get_sized_symbol(const Symbol*) const;
1385 // Return the count of undefined symbols seen.
1387 saw_undefined() const
1388 { return this->saw_undefined_; }
1390 // Allocate the common symbols
1392 allocate_commons(Layout*, Mapfile*);
1394 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1397 add_warning(const char* name, Object* obj, const std::string& warning)
1398 { this->warnings_.add_warning(this, name, obj, warning); }
1400 // Canonicalize a symbol name for use in the hash table.
1402 canonicalize_name(const char* name)
1403 { return this->namepool_.add(name, true, NULL); }
1405 // Possibly issue a warning for a reference to SYM at LOCATION which
1407 template<int size, bool big_endian>
1409 issue_warning(const Symbol* sym,
1410 const Relocate_info<size, big_endian>* relinfo,
1411 size_t relnum, off_t reloffset) const
1412 { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); }
1414 // Check candidate_odr_violations_ to find symbols with the same name
1415 // but apparently different definitions (different source-file/line-no).
1417 detect_odr_violations(const Task*, const char* output_file_name) const;
1419 // Add any undefined symbols named on the command line to the symbol
1422 add_undefined_symbols_from_command_line(Layout*);
1424 // SYM is defined using a COPY reloc. Return the dynamic object
1425 // where the original definition was found.
1427 get_copy_source(const Symbol* sym) const;
1429 // Set the dynamic symbol indexes. INDEX is the index of the first
1430 // global dynamic symbol. Pointers to the symbols are stored into
1431 // the vector. The names are stored into the Stringpool. This
1432 // returns an updated dynamic symbol index.
1434 set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*,
1435 Stringpool*, Versions*);
1437 // Finalize the symbol table after we have set the final addresses
1438 // of all the input sections. This sets the final symbol indexes,
1439 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1440 // index of the first global symbol. OFF is the file offset of the
1441 // global symbol table, DYNOFF is the offset of the globals in the
1442 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1443 // global dynamic symbol, and DYNCOUNT is the number of global
1444 // dynamic symbols. This records the parameters, and returns the
1445 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1448 finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount,
1449 Stringpool* pool, unsigned int *plocal_symcount);
1451 // Status code of Symbol_table::compute_final_value.
1452 enum Compute_final_value_status
1456 // Unspported symbol section.
1457 CFVS_UNSUPPORTED_SYMBOL_SECTION,
1458 // No output section.
1459 CFVS_NO_OUTPUT_SECTION
1462 // Compute the final value of SYM and store status in location PSTATUS.
1463 // During relaxation, this may be called multiple times for a symbol to
1464 // compute its would-be final value in each relaxation pass.
1467 typename Sized_symbol<size>::Value_type
1468 compute_final_value(const Sized_symbol<size>* sym,
1469 Compute_final_value_status* pstatus) const;
1471 // Write out the global symbols.
1473 write_globals(const Stringpool*, const Stringpool*,
1474 Output_symtab_xindex*, Output_symtab_xindex*,
1475 Output_file*) const;
1477 // Write out a section symbol. Return the updated offset.
1479 write_section_symbol(const Output_section*, Output_symtab_xindex*,
1480 Output_file*, off_t) const;
1482 // Dump statistical information to stderr.
1484 print_stats() const;
1486 // Return the version script information.
1487 const Version_script_info&
1488 version_script() const
1489 { return version_script_; }
1492 Symbol_table(const Symbol_table&);
1493 Symbol_table& operator=(const Symbol_table&);
1495 // The type of the list of common symbols.
1496 typedef std::vector<Symbol*> Commons_type;
1498 // The type of the symbol hash table.
1500 typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
1502 struct Symbol_table_hash
1505 operator()(const Symbol_table_key&) const;
1508 struct Symbol_table_eq
1511 operator()(const Symbol_table_key&, const Symbol_table_key&) const;
1514 typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
1515 Symbol_table_eq> Symbol_table_type;
1517 // Make FROM a forwarder symbol to TO.
1519 make_forwarder(Symbol* from, Symbol* to);
1522 template<int size, bool big_endian>
1524 add_from_object(Object*, const char *name, Stringpool::Key name_key,
1525 const char *version, Stringpool::Key version_key,
1526 bool def, const elfcpp::Sym<size, big_endian>& sym,
1527 unsigned int st_shndx, bool is_ordinary,
1528 unsigned int orig_st_shndx);
1530 // Define a default symbol.
1531 template<int size, bool big_endian>
1533 define_default_version(Sized_symbol<size>*, bool,
1534 Symbol_table_type::iterator);
1537 template<int size, bool big_endian>
1539 resolve(Sized_symbol<size>* to,
1540 const elfcpp::Sym<size, big_endian>& sym,
1541 unsigned int st_shndx, bool is_ordinary,
1542 unsigned int orig_st_shndx,
1543 Object*, const char* version);
1545 template<int size, bool big_endian>
1547 resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from);
1549 // Record that a symbol is forced to be local by a version script or
1552 force_local(Symbol*);
1554 // Adjust NAME and *NAME_KEY for wrapping.
1556 wrap_symbol(const char* name, Stringpool::Key* name_key);
1558 // Whether we should override a symbol, based on flags in
1561 should_override(const Symbol*, unsigned int, Defined, Object*, bool*, bool*);
1563 // Report a problem in symbol resolution.
1565 report_resolve_problem(bool is_error, const char* msg, const Symbol* to,
1566 Defined, Object* object);
1568 // Override a symbol.
1569 template<int size, bool big_endian>
1571 override(Sized_symbol<size>* tosym,
1572 const elfcpp::Sym<size, big_endian>& fromsym,
1573 unsigned int st_shndx, bool is_ordinary,
1574 Object* object, const char* version);
1576 // Whether we should override a symbol with a special symbol which
1577 // is automatically defined by the linker.
1579 should_override_with_special(const Symbol*, Defined);
1581 // Override a symbol with a special symbol.
1584 override_with_special(Sized_symbol<size>* tosym,
1585 const Sized_symbol<size>* fromsym);
1587 // Record all weak alias sets for a dynamic object.
1590 record_weak_aliases(std::vector<Sized_symbol<size>*>*);
1592 // Define a special symbol.
1593 template<int size, bool big_endian>
1595 define_special_symbol(const char** pname, const char** pversion,
1596 bool only_if_ref, Sized_symbol<size>** poldsym,
1597 bool* resolve_oldsym);
1599 // Define a symbol in an Output_data, sized version.
1602 do_define_in_output_data(const char* name, const char* version, Defined,
1604 typename elfcpp::Elf_types<size>::Elf_Addr value,
1605 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1606 elfcpp::STT type, elfcpp::STB binding,
1607 elfcpp::STV visibility, unsigned char nonvis,
1608 bool offset_is_from_end, bool only_if_ref);
1610 // Define a symbol in an Output_segment, sized version.
1613 do_define_in_output_segment(
1614 const char* name, const char* version, Defined, Output_segment* os,
1615 typename elfcpp::Elf_types<size>::Elf_Addr value,
1616 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1617 elfcpp::STT type, elfcpp::STB binding,
1618 elfcpp::STV visibility, unsigned char nonvis,
1619 Symbol::Segment_offset_base offset_base, bool only_if_ref);
1621 // Define a symbol as a constant, sized version.
1624 do_define_as_constant(
1625 const char* name, const char* version, Defined,
1626 typename elfcpp::Elf_types<size>::Elf_Addr value,
1627 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1628 elfcpp::STT type, elfcpp::STB binding,
1629 elfcpp::STV visibility, unsigned char nonvis,
1630 bool only_if_ref, bool force_override);
1632 // Add any undefined symbols named on the command line to the symbol
1633 // table, sized version.
1636 do_add_undefined_symbols_from_command_line(Layout*);
1638 // Add one undefined symbol.
1641 add_undefined_symbol_from_command_line(const char* name);
1643 // Types of common symbols.
1645 enum Commons_section_type
1653 // Allocate the common symbols, sized version.
1656 do_allocate_commons(Layout*, Mapfile*, Sort_commons_order);
1658 // Allocate the common symbols from one list.
1661 do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*,
1662 Mapfile*, Sort_commons_order);
1664 // Implement detect_odr_violations.
1665 template<int size, bool big_endian>
1667 sized_detect_odr_violations() const;
1669 // Finalize symbols specialized for size.
1672 sized_finalize(off_t, Stringpool*, unsigned int*);
1674 // Finalize a symbol. Return whether it should be added to the
1678 sized_finalize_symbol(Symbol*);
1680 // Add a symbol the final symtab by setting its index.
1683 add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff);
1685 // Write globals specialized for size and endianness.
1686 template<int size, bool big_endian>
1688 sized_write_globals(const Stringpool*, const Stringpool*,
1689 Output_symtab_xindex*, Output_symtab_xindex*,
1690 Output_file*) const;
1692 // Write out a symbol to P.
1693 template<int size, bool big_endian>
1695 sized_write_symbol(Sized_symbol<size>*,
1696 typename elfcpp::Elf_types<size>::Elf_Addr value,
1697 unsigned int shndx, elfcpp::STB,
1698 const Stringpool*, unsigned char* p) const;
1700 // Possibly warn about an undefined symbol from a dynamic object.
1702 warn_about_undefined_dynobj_symbol(Symbol*) const;
1704 // Write out a section symbol, specialized for size and endianness.
1705 template<int size, bool big_endian>
1707 sized_write_section_symbol(const Output_section*, Output_symtab_xindex*,
1708 Output_file*, off_t) const;
1710 // The type of the list of symbols which have been forced local.
1711 typedef std::vector<Symbol*> Forced_locals;
1713 // A map from symbols with COPY relocs to the dynamic objects where
1714 // they are defined.
1715 typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs;
1717 // A map from symbol name (as a pointer into the namepool) to all
1718 // the locations the symbols is (weakly) defined (and certain other
1719 // conditions are met). This map will be used later to detect
1720 // possible One Definition Rule (ODR) violations.
1721 struct Symbol_location
1723 Object* object; // Object where the symbol is defined.
1724 unsigned int shndx; // Section-in-object where the symbol is defined.
1725 off_t offset; // Offset-in-section where the symbol is defined.
1726 bool operator==(const Symbol_location& that) const
1728 return (this->object == that.object
1729 && this->shndx == that.shndx
1730 && this->offset == that.offset);
1734 struct Symbol_location_hash
1736 size_t operator()(const Symbol_location& loc) const
1737 { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; }
1740 typedef Unordered_map<const char*,
1741 Unordered_set<Symbol_location, Symbol_location_hash> >
1744 // We increment this every time we see a new undefined symbol, for
1745 // use in archive groups.
1746 size_t saw_undefined_;
1747 // The index of the first global symbol in the output file.
1748 unsigned int first_global_index_;
1749 // The file offset within the output symtab section where we should
1752 // The number of global symbols we want to write out.
1753 unsigned int output_count_;
1754 // The file offset of the global dynamic symbols, or 0 if none.
1755 off_t dynamic_offset_;
1756 // The index of the first global dynamic symbol.
1757 unsigned int first_dynamic_global_index_;
1758 // The number of global dynamic symbols, or 0 if none.
1759 unsigned int dynamic_count_;
1760 // The symbol hash table.
1761 Symbol_table_type table_;
1762 // A pool of symbol names. This is used for all global symbols.
1763 // Entries in the hash table point into this pool.
1764 Stringpool namepool_;
1765 // Forwarding symbols.
1766 Unordered_map<const Symbol*, Symbol*> forwarders_;
1767 // Weak aliases. A symbol in this list points to the next alias.
1768 // The aliases point to each other in a circular list.
1769 Unordered_map<Symbol*, Symbol*> weak_aliases_;
1770 // We don't expect there to be very many common symbols, so we keep
1771 // a list of them. When we find a common symbol we add it to this
1772 // list. It is possible that by the time we process the list the
1773 // symbol is no longer a common symbol. It may also have become a
1775 Commons_type commons_;
1776 // This is like the commons_ field, except that it holds TLS common
1778 Commons_type tls_commons_;
1779 // This is for small common symbols.
1780 Commons_type small_commons_;
1781 // This is for large common symbols.
1782 Commons_type large_commons_;
1783 // A list of symbols which have been forced to be local. We don't
1784 // expect there to be very many of them, so we keep a list of them
1785 // rather than walking the whole table to find them.
1786 Forced_locals forced_locals_;
1787 // Manage symbol warnings.
1789 // Manage potential One Definition Rule (ODR) violations.
1790 Odr_map candidate_odr_violations_;
1792 // When we emit a COPY reloc for a symbol, we define it in an
1793 // Output_data. When it's time to emit version information for it,
1794 // we need to know the dynamic object in which we found the original
1795 // definition. This maps symbols with COPY relocs to the dynamic
1796 // object where they were defined.
1797 Copied_symbol_dynobjs copied_symbol_dynobjs_;
1798 // Information parsed from the version script, if any.
1799 const Version_script_info& version_script_;
1800 Garbage_collection* gc_;
1804 // We inline get_sized_symbol for efficiency.
1808 Symbol_table::get_sized_symbol(Symbol* sym) const
1810 gold_assert(size == parameters->target().get_size());
1811 return static_cast<Sized_symbol<size>*>(sym);
1815 const Sized_symbol<size>*
1816 Symbol_table::get_sized_symbol(const Symbol* sym) const
1818 gold_assert(size == parameters->target().get_size());
1819 return static_cast<const Sized_symbol<size>*>(sym);
1822 } // End namespace gold.
1824 #endif // !defined(GOLD_SYMTAB_H)