1 // symtab.h -- the gold symbol table -*- C++ -*-
3 // Copyright 2006, 2007 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.
31 #include "parameters.h"
32 #include "stringpool.h"
43 template<int size, bool big_endian>
46 template<int size, bool big_endian>
55 // The base class of an entry in the symbol table. The symbol table
56 // can have a lot of entries, so we don't want this class to big.
57 // Size dependent fields can be found in the template class
58 // Sized_symbol. Targets may support their own derived classes.
63 // Because we want the class to be small, we don't use any virtual
64 // functions. But because symbols can be defined in different
65 // places, we need to classify them. This enum is the different
66 // sources of symbols we support.
69 // Symbol defined in a relocatable or dynamic input file--this is
70 // the most common case.
72 // Symbol defined in an Output_data, a special section created by
75 // Symbol defined in an Output_segment, with no associated
78 // Symbol value is constant.
82 // When the source is IN_OUTPUT_SEGMENT, we need to describe what
84 enum Segment_offset_base
86 // From the start of the segment.
88 // From the end of the segment.
90 // From the filesz of the segment--i.e., after the loaded bytes
91 // but before the bytes which are allocated but zeroed.
95 // Return the symbol name.
98 { return this->name_; }
100 // Return the symbol version. This will return NULL for an
101 // unversioned symbol.
104 { return this->version_; }
106 // Return the symbol source.
109 { return this->source_; }
111 // Return the object with which this symbol is associated.
115 gold_assert(this->source_ == FROM_OBJECT);
116 return this->u_.from_object.object;
119 // Return the index of the section in the input relocatable or
120 // dynamic object file.
124 gold_assert(this->source_ == FROM_OBJECT);
125 return this->u_.from_object.shndx;
128 // Return the output data section with which this symbol is
129 // associated, if the symbol was specially defined with respect to
130 // an output data section.
134 gold_assert(this->source_ == IN_OUTPUT_DATA);
135 return this->u_.in_output_data.output_data;
138 // If this symbol was defined with respect to an output data
139 // section, return whether the value is an offset from end.
141 offset_is_from_end() const
143 gold_assert(this->source_ == IN_OUTPUT_DATA);
144 return this->u_.in_output_data.offset_is_from_end;
147 // Return the output segment with which this symbol is associated,
148 // if the symbol was specially defined with respect to an output
151 output_segment() const
153 gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
154 return this->u_.in_output_segment.output_segment;
157 // If this symbol was defined with respect to an output segment,
158 // return the offset base.
162 gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
163 return this->u_.in_output_segment.offset_base;
166 // Return the symbol binding.
169 { return this->binding_; }
171 // Return the symbol type.
174 { return this->type_; }
176 // Return the symbol visibility.
179 { return this->visibility_; }
181 // Return the non-visibility part of the st_other field.
184 { return this->nonvis_; }
186 // Return whether this symbol is a forwarder. This will never be
187 // true of a symbol found in the hash table, but may be true of
188 // symbol pointers attached to object files.
191 { return this->is_forwarder_; }
193 // Mark this symbol as a forwarder.
196 { this->is_forwarder_ = true; }
198 // Return whether this symbol has an alias in the weak aliases table
202 { return this->has_alias_; }
204 // Mark this symbol as having an alias.
207 { this->has_alias_ = true; }
209 // Return whether this symbol needs an entry in the dynamic symbol
212 needs_dynsym_entry() const
214 return (this->needs_dynsym_entry_
215 || (this->in_reg() && this->in_dyn()));
218 // Mark this symbol as needing an entry in the dynamic symbol table.
220 set_needs_dynsym_entry()
221 { this->needs_dynsym_entry_ = true; }
223 // Return whether this symbol has been seen in a regular object.
226 { return this->in_reg_; }
228 // Mark this symbol as having been seen in a regular object.
231 { this->in_reg_ = true; }
233 // Return whether this symbol has been seen in a dynamic object.
236 { return this->in_dyn_; }
238 // Mark this symbol as having been seen in a dynamic object.
241 { this->in_dyn_ = true; }
243 // Return the index of this symbol in the output file symbol table.
244 // A value of -1U means that this symbol is not going into the
245 // output file. This starts out as zero, and is set to a non-zero
246 // value by Symbol_table::finalize. It is an error to ask for the
247 // symbol table index before it has been set.
251 gold_assert(this->symtab_index_ != 0);
252 return this->symtab_index_;
255 // Set the index of the symbol in the output file symbol table.
257 set_symtab_index(unsigned int index)
259 gold_assert(index != 0);
260 this->symtab_index_ = index;
263 // Return whether this symbol already has an index in the output
264 // file symbol table.
266 has_symtab_index() const
267 { return this->symtab_index_ != 0; }
269 // Return the index of this symbol in the dynamic symbol table. A
270 // value of -1U means that this symbol is not going into the dynamic
271 // symbol table. This starts out as zero, and is set to a non-zero
272 // during Layout::finalize. It is an error to ask for the dynamic
273 // symbol table index before it has been set.
277 gold_assert(this->dynsym_index_ != 0);
278 return this->dynsym_index_;
281 // Set the index of the symbol in the dynamic symbol table.
283 set_dynsym_index(unsigned int index)
285 gold_assert(index != 0);
286 this->dynsym_index_ = index;
289 // Return whether this symbol already has an index in the dynamic
292 has_dynsym_index() const
293 { return this->dynsym_index_ != 0; }
295 // Return whether this symbol has an entry in the GOT section.
297 has_got_offset() const
298 { return this->has_got_offset_; }
300 // Return the offset into the GOT section of this symbol.
304 gold_assert(this->has_got_offset());
305 return this->got_offset_;
308 // Set the GOT offset of this symbol.
310 set_got_offset(unsigned int got_offset)
312 this->has_got_offset_ = true;
313 this->got_offset_ = got_offset;
316 // Return whether this symbol has an entry in the PLT section.
318 has_plt_offset() const
319 { return this->has_plt_offset_; }
321 // Return the offset into the PLT section of this symbol.
325 gold_assert(this->has_plt_offset());
326 return this->plt_offset_;
329 // Set the PLT offset of this symbol.
331 set_plt_offset(unsigned int plt_offset)
333 this->has_plt_offset_ = true;
334 this->plt_offset_ = plt_offset;
337 // Return whether this dynamic symbol needs a special value in the
338 // dynamic symbol table.
340 needs_dynsym_value() const
341 { return this->needs_dynsym_value_; }
343 // Set that this dynamic symbol needs a special value in the dynamic
346 set_needs_dynsym_value()
348 gold_assert(this->object()->is_dynamic());
349 this->needs_dynsym_value_ = true;
352 // Return true if the final value of this symbol is known at link
355 final_value_is_known() const;
357 // Return whether this is a defined symbol (not undefined or
362 return (this->source_ != FROM_OBJECT
363 || (this->shndx() != elfcpp::SHN_UNDEF
364 && this->shndx() != elfcpp::SHN_COMMON));
367 // Return true if this symbol is from a dynamic object.
369 is_from_dynobj() const
371 return this->source_ == FROM_OBJECT && this->object()->is_dynamic();
374 // Return whether this is an undefined symbol.
378 return this->source_ == FROM_OBJECT && this->shndx() == elfcpp::SHN_UNDEF;
381 // Return whether this is a common symbol.
385 return (this->source_ == FROM_OBJECT
386 && (this->shndx() == elfcpp::SHN_COMMON
387 || this->type_ == elfcpp::STT_COMMON));
390 // Return whether this symbol can be seen outside this object.
392 is_externally_visible() const
394 return (this->visibility_ == elfcpp::STV_DEFAULT
395 || this->visibility_ == elfcpp::STV_PROTECTED);
398 // Return whether there should be a warning for references to this
402 { return this->has_warning_; }
404 // Mark this symbol as having a warning.
407 { this->has_warning_ = true; }
410 // Instances of this class should always be created at a specific
413 { memset(this, 0, sizeof *this); }
415 // Initialize the general fields.
417 init_fields(const char* name, const char* version,
418 elfcpp::STT type, elfcpp::STB binding,
419 elfcpp::STV visibility, unsigned char nonvis);
421 // Initialize fields from an ELF symbol in OBJECT.
422 template<int size, bool big_endian>
424 init_base(const char *name, const char* version, Object* object,
425 const elfcpp::Sym<size, big_endian>&);
427 // Initialize fields for an Output_data.
429 init_base(const char* name, Output_data*, elfcpp::STT, elfcpp::STB,
430 elfcpp::STV, unsigned char nonvis, bool offset_is_from_end);
432 // Initialize fields for an Output_segment.
434 init_base(const char* name, Output_segment* os, elfcpp::STT type,
435 elfcpp::STB binding, elfcpp::STV visibility,
436 unsigned char nonvis, Segment_offset_base offset_base);
438 // Initialize fields for a constant.
440 init_base(const char* name, elfcpp::STT type, elfcpp::STB binding,
441 elfcpp::STV visibility, unsigned char nonvis);
443 // Override existing symbol.
444 template<int size, bool big_endian>
446 override_base(const elfcpp::Sym<size, big_endian>&, Object* object,
447 const char* version);
449 // Override existing symbol with a special symbol.
451 override_base_with_special(const Symbol* from);
454 Symbol(const Symbol&);
455 Symbol& operator=(const Symbol&);
457 // Symbol name (expected to point into a Stringpool).
459 // Symbol version (expected to point into a Stringpool). This may
461 const char* version_;
465 // This struct is used if SOURCE_ == FROM_OBJECT.
468 // Object in which symbol is defined, or in which it was first
471 // Section number in object_ in which symbol is defined.
475 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
478 // Output_data in which symbol is defined. Before
479 // Layout::finalize the symbol's value is an offset within the
481 Output_data* output_data;
482 // True if the offset is from the end, false if the offset is
483 // from the beginning.
484 bool offset_is_from_end;
487 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
490 // Output_segment in which the symbol is defined. Before
491 // Layout::finalize the symbol's value is an offset.
492 Output_segment* output_segment;
493 // The base to use for the offset before Layout::finalize.
494 Segment_offset_base offset_base;
498 // The index of this symbol in the output file. If the symbol is
499 // not going into the output file, this value is -1U. This field
500 // starts as always holding zero. It is set to a non-zero value by
501 // Symbol_table::finalize.
502 unsigned int symtab_index_;
504 // The index of this symbol in the dynamic symbol table. If the
505 // symbol is not going into the dynamic symbol table, this value is
506 // -1U. This field starts as always holding zero. It is set to a
507 // non-zero value during Layout::finalize.
508 unsigned int dynsym_index_;
510 // If this symbol has an entry in the GOT section (has_got_offset_
511 // is true), this is the offset from the start of the GOT section.
512 unsigned int got_offset_;
514 // If this symbol has an entry in the PLT section (has_plt_offset_
515 // is true), then this is the offset from the start of the PLT
517 unsigned int plt_offset_;
520 elfcpp::STT type_ : 4;
522 elfcpp::STB binding_ : 4;
523 // Symbol visibility.
524 elfcpp::STV visibility_ : 2;
525 // Rest of symbol st_other field.
526 unsigned int nonvis_ : 6;
527 // The type of symbol.
529 // True if this symbol always requires special target-specific
531 bool is_target_special_ : 1;
532 // True if this is the default version of the symbol.
534 // True if this symbol really forwards to another symbol. This is
535 // used when we discover after the fact that two different entries
536 // in the hash table really refer to the same symbol. This will
537 // never be set for a symbol found in the hash table, but may be set
538 // for a symbol found in the list of symbols attached to an Object.
539 // It forwards to the symbol found in the forwarders_ map of
541 bool is_forwarder_ : 1;
542 // True if the symbol has an alias in the weak_aliases table in
545 // True if this symbol needs to be in the dynamic symbol table.
546 bool needs_dynsym_entry_ : 1;
547 // True if we've seen this symbol in a regular object.
549 // True if we've seen this symbol in a dynamic object.
551 // True if the symbol has an entry in the GOT section.
552 bool has_got_offset_ : 1;
553 // True if the symbol has an entry in the PLT section.
554 bool has_plt_offset_ : 1;
555 // True if this is a dynamic symbol which needs a special value in
556 // the dynamic symbol table.
557 bool needs_dynsym_value_ : 1;
558 // True if there is a warning for this symbol.
559 bool has_warning_ : 1;
562 // The parts of a symbol which are size specific. Using a template
563 // derived class like this helps us use less space on a 32-bit system.
566 class Sized_symbol : public Symbol
569 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type;
570 typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type;
575 // Initialize fields from an ELF symbol in OBJECT.
576 template<bool big_endian>
578 init(const char *name, const char* version, Object* object,
579 const elfcpp::Sym<size, big_endian>&);
581 // Initialize fields for an Output_data.
583 init(const char* name, Output_data*, Value_type value, Size_type symsize,
584 elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis,
585 bool offset_is_from_end);
587 // Initialize fields for an Output_segment.
589 init(const char* name, Output_segment*, Value_type value, Size_type symsize,
590 elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis,
591 Segment_offset_base offset_base);
593 // Initialize fields for a constant.
595 init(const char* name, Value_type value, Size_type symsize,
596 elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis);
598 // Override existing symbol.
599 template<bool big_endian>
601 override(const elfcpp::Sym<size, big_endian>&, Object* object,
602 const char* version);
604 // Override existing symbol with a special symbol.
606 override_with_special(const Sized_symbol<size>*);
608 // Return the symbol's value.
611 { return this->value_; }
613 // Return the symbol's size (we can't call this 'size' because that
614 // is a template parameter).
617 { return this->symsize_; }
619 // Set the symbol size. This is used when resolving common symbols.
621 set_symsize(Size_type symsize)
622 { this->symsize_ = symsize; }
624 // Set the symbol value. This is called when we store the final
625 // values of the symbols into the symbol table.
627 set_value(Value_type value)
628 { this->value_ = value; }
631 Sized_symbol(const Sized_symbol&);
632 Sized_symbol& operator=(const Sized_symbol&);
634 // Symbol value. Before Layout::finalize this is the offset in the
635 // input section. This is set to the final value during
642 // A struct describing a symbol defined by the linker, where the value
643 // of the symbol is defined based on an output section. This is used
644 // for symbols defined by the linker, like "_init_array_start".
646 struct Define_symbol_in_section
650 // The name of the output section with which this symbol should be
651 // associated. If there is no output section with that name, the
652 // symbol will be defined as zero.
653 const char* output_section;
654 // The offset of the symbol within the output section. This is an
655 // offset from the start of the output section, unless start_at_end
656 // is true, in which case this is an offset from the end of the
659 // The size of the symbol.
663 // The symbol binding.
665 // The symbol visibility.
666 elfcpp::STV visibility;
667 // The rest of the st_other field.
668 unsigned char nonvis;
669 // If true, the value field is an offset from the end of the output
671 bool offset_is_from_end;
672 // If true, this symbol is defined only if we see a reference to it.
676 // A struct describing a symbol defined by the linker, where the value
677 // of the symbol is defined based on a segment. This is used for
678 // symbols defined by the linker, like "_end". We describe the
679 // segment with which the symbol should be associated by its
680 // characteristics. If no segment meets these characteristics, the
681 // symbol will be defined as zero. If there is more than one segment
682 // which meets these characteristics, we will use the first one.
684 struct Define_symbol_in_segment
688 // The segment type where the symbol should be defined, typically
690 elfcpp::PT segment_type;
691 // Bitmask of segment flags which must be set.
692 elfcpp::PF segment_flags_set;
693 // Bitmask of segment flags which must be clear.
694 elfcpp::PF segment_flags_clear;
695 // The offset of the symbol within the segment. The offset is
696 // calculated from the position set by offset_base.
698 // The size of the symbol.
702 // The symbol binding.
704 // The symbol visibility.
705 elfcpp::STV visibility;
706 // The rest of the st_other field.
707 unsigned char nonvis;
708 // The base from which we compute the offset.
709 Symbol::Segment_offset_base offset_base;
710 // If true, this symbol is defined only if we see a reference to it.
714 // This class manages warnings. Warnings are a GNU extension. When
715 // we see a section named .gnu.warning.SYM in an object file, and if
716 // we wind using the definition of SYM from that object file, then we
717 // will issue a warning for any relocation against SYM from a
718 // different object file. The text of the warning is the contents of
719 // the section. This is not precisely the definition used by the old
720 // GNU linker; the old GNU linker treated an occurrence of
721 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
722 // would trigger a warning on any reference. However, it was
723 // inconsistent in that a warning in a dynamic object only triggered
724 // if there was no definition in a regular object. This linker is
725 // different in that we only issue a warning if we use the symbol
726 // definition from the same object file as the warning section.
735 // Add a warning for symbol NAME in section SHNDX in object OBJ.
737 add_warning(Symbol_table* symtab, const char* name, Object* obj,
740 // For each symbol for which we should give a warning, make a note
743 note_warnings(Symbol_table* symtab);
745 // Issue a warning for a reference to SYM at RELINFO's location.
746 template<int size, bool big_endian>
748 issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*,
749 size_t relnum, off_t reloffset) const;
752 Warnings(const Warnings&);
753 Warnings& operator=(const Warnings&);
755 // What we need to know to get the warning text.
756 struct Warning_location
758 // The object the warning is in.
760 // The index of the warning section.
762 // The warning text if we have already loaded it.
766 : object(NULL), shndx(0), text()
770 set(Object* o, unsigned int s)
777 set_text(const char* t, off_t l)
778 { this->text.assign(t, l); }
781 // A mapping from warning symbol names (canonicalized in
782 // Symbol_table's namepool_ field) to
783 typedef Unordered_map<const char*, Warning_location> Warning_table;
785 Warning_table warnings_;
788 // The main linker symbol table.
797 // Add COUNT external symbols from the relocatable object RELOBJ to
798 // the symbol table. SYMS is the symbols, SYM_NAMES is their names,
799 // SYM_NAME_SIZE is the size of SYM_NAMES. This sets SYMPOINTERS to
800 // point to the symbols in the symbol table.
801 template<int size, bool big_endian>
803 add_from_relobj(Sized_relobj<size, big_endian>* relobj,
804 const unsigned char* syms, size_t count,
805 const char* sym_names, size_t sym_name_size,
806 Symbol** sympointers);
808 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
809 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
810 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
811 // symbol version data.
812 template<int size, bool big_endian>
814 add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj,
815 const unsigned char* syms, size_t count,
816 const char* sym_names, size_t sym_name_size,
817 const unsigned char* versym, size_t versym_size,
818 const std::vector<const char*>*);
820 // Define a special symbol based on an Output_data. It is a
821 // multiple definition error if this symbol is already defined.
823 define_in_output_data(const Target*, const char* name, const char* version,
824 Output_data*, uint64_t value, uint64_t symsize,
825 elfcpp::STT type, elfcpp::STB binding,
826 elfcpp::STV visibility, unsigned char nonvis,
827 bool offset_is_from_end, bool only_if_ref);
829 // Define a special symbol based on an Output_segment. It is a
830 // multiple definition error if this symbol is already defined.
832 define_in_output_segment(const Target*, const char* name,
833 const char* version, Output_segment*,
834 uint64_t value, uint64_t symsize,
835 elfcpp::STT type, elfcpp::STB binding,
836 elfcpp::STV visibility, unsigned char nonvis,
837 Symbol::Segment_offset_base, bool only_if_ref);
839 // Define a special symbol with a constant value. It is a multiple
840 // definition error if this symbol is already defined.
842 define_as_constant(const Target*, const char* name, const char* version,
843 uint64_t value, uint64_t symsize, elfcpp::STT type,
844 elfcpp::STB binding, elfcpp::STV visibility,
845 unsigned char nonvis, bool only_if_ref);
847 // Define a set of symbols in output sections.
849 define_symbols(const Layout*, const Target*, int count,
850 const Define_symbol_in_section*);
852 // Define a set of symbols in output segments.
854 define_symbols(const Layout*, const Target*, int count,
855 const Define_symbol_in_segment*);
859 lookup(const char*, const char* version = NULL) const;
861 // Return the real symbol associated with the forwarder symbol FROM.
863 resolve_forwards(const Symbol* from) const;
865 // Return the sized version of a symbol in this table.
868 get_sized_symbol(Symbol* ACCEPT_SIZE) const;
871 const Sized_symbol<size>*
872 get_sized_symbol(const Symbol* ACCEPT_SIZE) const;
874 // Return the count of undefined symbols seen.
876 saw_undefined() const
877 { return this->saw_undefined_; }
879 // Allocate the common symbols
881 allocate_commons(const General_options&, Layout*);
883 // Add a warning for symbol NAME in section SHNDX in object OBJ.
885 add_warning(const char* name, Object* obj, unsigned int shndx)
886 { this->warnings_.add_warning(this, name, obj, shndx); }
888 // Canonicalize a symbol name for use in the hash table.
890 canonicalize_name(const char* name)
891 { return this->namepool_.add(name, true, NULL); }
893 // Possibly issue a warning for a reference to SYM at LOCATION which
895 template<int size, bool big_endian>
897 issue_warning(const Symbol* sym,
898 const Relocate_info<size, big_endian>* relinfo,
899 size_t relnum, off_t reloffset) const
900 { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); }
902 // Set the dynamic symbol indexes. INDEX is the index of the first
903 // global dynamic symbol. Pointers to the symbols are stored into
904 // the vector. The names are stored into the Stringpool. This
905 // returns an updated dynamic symbol index.
907 set_dynsym_indexes(const General_options*, const Target*, unsigned int index,
908 std::vector<Symbol*>*, Stringpool*, Versions*);
910 // Finalize the symbol table after we have set the final addresses
911 // of all the input sections. This sets the final symbol indexes,
912 // values and adds the names to *POOL. INDEX is the index of the
913 // first global symbol. OFF is the file offset of the global symbol
914 // table, DYNOFF is the offset of the globals in the dynamic symbol
915 // table, DYN_GLOBAL_INDEX is the index of the first global dynamic
916 // symbol, and DYNCOUNT is the number of global dynamic symbols.
917 // This records the parameters, and returns the new file offset.
919 finalize(unsigned int index, off_t off, off_t dynoff,
920 size_t dyn_global_index, size_t dyncount, Stringpool* pool);
922 // Write out the global symbols.
924 write_globals(const Target*, const Stringpool*, const Stringpool*,
927 // Write out a section symbol. Return the updated offset.
929 write_section_symbol(const Output_section*, Output_file*, off_t) const;
932 Symbol_table(const Symbol_table&);
933 Symbol_table& operator=(const Symbol_table&);
935 // Make FROM a forwarder symbol to TO.
937 make_forwarder(Symbol* from, Symbol* to);
940 template<int size, bool big_endian>
942 add_from_object(Object*, const char *name, Stringpool::Key name_key,
943 const char *version, Stringpool::Key version_key,
944 bool def, const elfcpp::Sym<size, big_endian>& sym);
947 template<int size, bool big_endian>
949 resolve(Sized_symbol<size>* to,
950 const elfcpp::Sym<size, big_endian>& sym,
951 Object*, const char* version);
953 template<int size, bool big_endian>
955 resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
956 const char* version ACCEPT_SIZE_ENDIAN);
958 // Whether we should override a symbol, based on flags in
961 should_override(const Symbol*, unsigned int, Object*, bool*);
963 // Override a symbol.
964 template<int size, bool big_endian>
966 override(Sized_symbol<size>* tosym,
967 const elfcpp::Sym<size, big_endian>& fromsym,
968 Object* object, const char* version);
970 // Whether we should override a symbol with a special symbol which
971 // is automatically defined by the linker.
973 should_override_with_special(const Symbol*);
975 // Override a symbol with a special symbol.
978 override_with_special(Sized_symbol<size>* tosym,
979 const Sized_symbol<size>* fromsym);
981 // Record all weak alias sets for a dynamic object.
984 record_weak_aliases(std::vector<Sized_symbol<size>*>*);
986 // Define a special symbol.
987 template<int size, bool big_endian>
989 define_special_symbol(const Target* target, const char** pname,
990 const char** pversion, bool only_if_ref,
991 Sized_symbol<size>** poldsym ACCEPT_SIZE_ENDIAN);
993 // Define a symbol in an Output_data, sized version.
996 do_define_in_output_data(const Target*, const char* name,
997 const char* version, Output_data*,
998 typename elfcpp::Elf_types<size>::Elf_Addr value,
999 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1000 elfcpp::STT type, elfcpp::STB binding,
1001 elfcpp::STV visibility, unsigned char nonvis,
1002 bool offset_is_from_end, bool only_if_ref);
1004 // Define a symbol in an Output_segment, sized version.
1007 do_define_in_output_segment(
1008 const Target*, const char* name, const char* version, Output_segment* os,
1009 typename elfcpp::Elf_types<size>::Elf_Addr value,
1010 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1011 elfcpp::STT type, elfcpp::STB binding,
1012 elfcpp::STV visibility, unsigned char nonvis,
1013 Symbol::Segment_offset_base offset_base, bool only_if_ref);
1015 // Define a symbol as a constant, sized version.
1018 do_define_as_constant(
1019 const Target*, const char* name, const char* version,
1020 typename elfcpp::Elf_types<size>::Elf_Addr value,
1021 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1022 elfcpp::STT type, elfcpp::STB binding,
1023 elfcpp::STV visibility, unsigned char nonvis,
1026 // Allocate the common symbols, sized version.
1029 do_allocate_commons(const General_options&, Layout*);
1031 // Finalize symbols specialized for size.
1034 sized_finalize(unsigned int, off_t, Stringpool*);
1036 // Write globals specialized for size and endianness.
1037 template<int size, bool big_endian>
1039 sized_write_globals(const Target*, const Stringpool*, const Stringpool*,
1040 Output_file*) const;
1042 // Write out a symbol to P.
1043 template<int size, bool big_endian>
1045 sized_write_symbol(Sized_symbol<size>*,
1046 typename elfcpp::Elf_types<size>::Elf_Addr value,
1048 const Stringpool*, unsigned char* p
1049 ACCEPT_SIZE_ENDIAN) const;
1051 // Write out a section symbol, specialized for size and endianness.
1052 template<int size, bool big_endian>
1054 sized_write_section_symbol(const Output_section*, Output_file*, off_t) const;
1056 // The type of the symbol hash table.
1058 typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
1060 struct Symbol_table_hash
1063 operator()(const Symbol_table_key&) const;
1066 struct Symbol_table_eq
1069 operator()(const Symbol_table_key&, const Symbol_table_key&) const;
1072 typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
1073 Symbol_table_eq> Symbol_table_type;
1075 // The type of the list of common symbols.
1077 typedef std::vector<Symbol*> Commons_type;
1079 // We increment this every time we see a new undefined symbol, for
1080 // use in archive groups.
1083 // The index of the first global symbol in the output file.
1084 unsigned int first_global_index_;
1086 // The file offset within the output symtab section where we should
1090 // The number of global symbols we want to write out.
1091 size_t output_count_;
1093 // The file offset of the global dynamic symbols, or 0 if none.
1094 off_t dynamic_offset_;
1096 // The index of the first global dynamic symbol.
1097 unsigned int first_dynamic_global_index_;
1099 // The number of global dynamic symbols, or 0 if none.
1100 off_t dynamic_count_;
1102 // The symbol hash table.
1103 Symbol_table_type table_;
1105 // A pool of symbol names. This is used for all global symbols.
1106 // Entries in the hash table point into this pool.
1107 Stringpool namepool_;
1109 // Forwarding symbols.
1110 Unordered_map<const Symbol*, Symbol*> forwarders_;
1112 // Weak aliases. A symbol in this list points to the next alias.
1113 // The aliases point to each other in a circular list.
1114 Unordered_map<Symbol*, Symbol*> weak_aliases_;
1116 // We don't expect there to be very many common symbols, so we keep
1117 // a list of them. When we find a common symbol we add it to this
1118 // list. It is possible that by the time we process the list the
1119 // symbol is no longer a common symbol. It may also have become a
1121 Commons_type commons_;
1123 // Manage symbol warnings.
1127 // We inline get_sized_symbol for efficiency.
1131 Symbol_table::get_sized_symbol(Symbol* sym ACCEPT_SIZE) const
1133 gold_assert(size == parameters->get_size());
1134 return static_cast<Sized_symbol<size>*>(sym);
1138 const Sized_symbol<size>*
1139 Symbol_table::get_sized_symbol(const Symbol* sym ACCEPT_SIZE) const
1141 gold_assert(size == parameters->get_size());
1142 return static_cast<const Sized_symbol<size>*>(sym);
1145 } // End namespace gold.
1147 #endif // !defined(GOLD_SYMTAB_H)