1 // symtab.h -- the gold symbol table -*- C++ -*-
3 // Copyright (C) 2006-2015 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>
45 class Sized_relobj_file;
46 template<int size, bool big_endian>
47 class Sized_pluginobj;
49 template<int size, bool big_endian>
51 template<int size, bool big_endian>
54 class Version_script_info;
60 class Output_symtab_xindex;
61 class Garbage_collection;
64 // The base class of an entry in the symbol table. The symbol table
65 // can have a lot of entries, so we don't want this class too big.
66 // Size dependent fields can be found in the template class
67 // Sized_symbol. Targets may support their own derived classes.
72 // Because we want the class to be small, we don't use any virtual
73 // functions. But because symbols can be defined in different
74 // places, we need to classify them. This enum is the different
75 // sources of symbols we support.
78 // Symbol defined in a relocatable or dynamic input file--this is
79 // the most common case.
81 // Symbol defined in an Output_data, a special section created by
84 // Symbol defined in an Output_segment, with no associated
87 // Symbol value is constant.
89 // Symbol is undefined.
93 // When the source is IN_OUTPUT_SEGMENT, we need to describe what
95 enum Segment_offset_base
97 // From the start of the segment.
99 // From the end of the segment.
101 // From the filesz of the segment--i.e., after the loaded bytes
102 // but before the bytes which are allocated but zeroed.
106 // Return the symbol name.
109 { return this->name_; }
111 // Return the (ANSI) demangled version of the name, if
112 // parameters.demangle() is true. Otherwise, return the name. This
113 // is intended to be used only for logging errors, so it's not
116 demangled_name() const;
118 // Return the symbol version. This will return NULL for an
119 // unversioned symbol.
122 { return this->version_; }
126 { this->version_ = NULL; }
128 // Return whether this version is the default for this symbol name
129 // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only
130 // meaningful for versioned symbols.
134 gold_assert(this->version_ != NULL);
135 return this->is_def_;
138 // Set that this version is the default for this symbol name.
141 { this->is_def_ = true; }
143 // Return the symbol's name as name@version (or name@@version).
145 versioned_name() const;
147 // Return the symbol source.
150 { return this->source_; }
152 // Return the object with which this symbol is associated.
156 gold_assert(this->source_ == FROM_OBJECT);
157 return this->u_.from_object.object;
160 // Return the index of the section in the input relocatable or
161 // dynamic object file.
163 shndx(bool* is_ordinary) const
165 gold_assert(this->source_ == FROM_OBJECT);
166 *is_ordinary = this->is_ordinary_shndx_;
167 return this->u_.from_object.shndx;
170 // Return the output data section with which this symbol is
171 // associated, if the symbol was specially defined with respect to
172 // an output data section.
176 gold_assert(this->source_ == IN_OUTPUT_DATA);
177 return this->u_.in_output_data.output_data;
180 // If this symbol was defined with respect to an output data
181 // section, return whether the value is an offset from end.
183 offset_is_from_end() const
185 gold_assert(this->source_ == IN_OUTPUT_DATA);
186 return this->u_.in_output_data.offset_is_from_end;
189 // Return the output segment with which this symbol is associated,
190 // if the symbol was specially defined with respect to an output
193 output_segment() const
195 gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
196 return this->u_.in_output_segment.output_segment;
199 // If this symbol was defined with respect to an output segment,
200 // return the offset base.
204 gold_assert(this->source_ == IN_OUTPUT_SEGMENT);
205 return this->u_.in_output_segment.offset_base;
208 // Return the symbol binding.
211 { return this->binding_; }
213 // Return the symbol type.
216 { return this->type_; }
218 // Set the symbol type.
220 set_type(elfcpp::STT type)
221 { this->type_ = type; }
223 // Return true for function symbol.
227 return (this->type_ == elfcpp::STT_FUNC
228 || this->type_ == elfcpp::STT_GNU_IFUNC);
231 // Return the symbol visibility.
234 { return this->visibility_; }
236 // Set the visibility.
238 set_visibility(elfcpp::STV visibility)
239 { this->visibility_ = visibility; }
241 // Override symbol visibility.
243 override_visibility(elfcpp::STV);
245 // Set whether the symbol was originally a weak undef or a regular undef
246 // when resolved by a dynamic def or by a special symbol.
248 set_undef_binding(elfcpp::STB bind)
250 if (!this->undef_binding_set_ || this->undef_binding_weak_)
252 this->undef_binding_weak_ = bind == elfcpp::STB_WEAK;
253 this->undef_binding_set_ = true;
257 // Return TRUE if a weak undef was resolved by a dynamic def or
258 // by a special symbol.
260 is_undef_binding_weak() const
261 { return this->undef_binding_weak_; }
263 // Return the non-visibility part of the st_other field.
266 { return this->nonvis_; }
268 // Set the non-visibility part of the st_other field.
270 set_nonvis(unsigned int nonvis)
271 { this->nonvis_ = nonvis; }
273 // Return whether this symbol is a forwarder. This will never be
274 // true of a symbol found in the hash table, but may be true of
275 // symbol pointers attached to object files.
278 { return this->is_forwarder_; }
280 // Mark this symbol as a forwarder.
283 { this->is_forwarder_ = true; }
285 // Return whether this symbol has an alias in the weak aliases table
289 { return this->has_alias_; }
291 // Mark this symbol as having an alias.
294 { this->has_alias_ = true; }
296 // Return whether this symbol needs an entry in the dynamic symbol
299 needs_dynsym_entry() const
301 return (this->needs_dynsym_entry_
304 && this->is_externally_visible()));
307 // Mark this symbol as needing an entry in the dynamic symbol table.
309 set_needs_dynsym_entry()
310 { this->needs_dynsym_entry_ = true; }
312 // Return whether this symbol should be added to the dynamic symbol
315 should_add_dynsym_entry(Symbol_table*) const;
317 // Return whether this symbol has been seen in a regular object.
320 { return this->in_reg_; }
322 // Mark this symbol as having been seen in a regular object.
325 { this->in_reg_ = true; }
327 // Return whether this symbol has been seen in a dynamic object.
330 { return this->in_dyn_; }
332 // Mark this symbol as having been seen in a dynamic object.
335 { this->in_dyn_ = true; }
337 // Return whether this symbol has been seen in a real ELF object.
338 // (IN_REG will return TRUE if the symbol has been seen in either
339 // a real ELF object or an object claimed by a plugin.)
342 { return this->in_real_elf_; }
344 // Mark this symbol as having been seen in a real ELF object.
347 { this->in_real_elf_ = true; }
349 // Return whether this symbol was defined in a section that was
350 // discarded from the link. This is used to control some error
353 is_defined_in_discarded_section() const
354 { return this->is_defined_in_discarded_section_; }
356 // Mark this symbol as having been defined in a discarded section.
358 set_is_defined_in_discarded_section()
359 { this->is_defined_in_discarded_section_ = true; }
361 // Return the index of this symbol in the output file symbol table.
362 // A value of -1U means that this symbol is not going into the
363 // output file. This starts out as zero, and is set to a non-zero
364 // value by Symbol_table::finalize. It is an error to ask for the
365 // symbol table index before it has been set.
369 gold_assert(this->symtab_index_ != 0);
370 return this->symtab_index_;
373 // Set the index of the symbol in the output file symbol table.
375 set_symtab_index(unsigned int index)
377 gold_assert(index != 0);
378 this->symtab_index_ = index;
381 // Return whether this symbol already has an index in the output
382 // file symbol table.
384 has_symtab_index() const
385 { return this->symtab_index_ != 0; }
387 // Return the index of this symbol in the dynamic symbol table. A
388 // value of -1U means that this symbol is not going into the dynamic
389 // symbol table. This starts out as zero, and is set to a non-zero
390 // during Layout::finalize. It is an error to ask for the dynamic
391 // symbol table index before it has been set.
395 gold_assert(this->dynsym_index_ != 0);
396 return this->dynsym_index_;
399 // Set the index of the symbol in the dynamic symbol table.
401 set_dynsym_index(unsigned int index)
403 gold_assert(index != 0);
404 this->dynsym_index_ = index;
407 // Return whether this symbol already has an index in the dynamic
410 has_dynsym_index() const
411 { return this->dynsym_index_ != 0; }
413 // Return whether this symbol has an entry in the GOT section.
414 // For a TLS symbol, this GOT entry will hold its tp-relative offset.
416 has_got_offset(unsigned int got_type) const
417 { return this->got_offsets_.get_offset(got_type) != -1U; }
419 // Return the offset into the GOT section of this symbol.
421 got_offset(unsigned int got_type) const
423 unsigned int got_offset = this->got_offsets_.get_offset(got_type);
424 gold_assert(got_offset != -1U);
428 // Set the GOT offset of this symbol.
430 set_got_offset(unsigned int got_type, unsigned int got_offset)
431 { this->got_offsets_.set_offset(got_type, got_offset); }
433 // Return the GOT offset list.
434 const Got_offset_list*
435 got_offset_list() const
436 { return this->got_offsets_.get_list(); }
438 // Return whether this symbol has an entry in the PLT section.
440 has_plt_offset() const
441 { return this->plt_offset_ != -1U; }
443 // Return the offset into the PLT section of this symbol.
447 gold_assert(this->has_plt_offset());
448 return this->plt_offset_;
451 // Set the PLT offset of this symbol.
453 set_plt_offset(unsigned int plt_offset)
455 gold_assert(plt_offset != -1U);
456 this->plt_offset_ = plt_offset;
459 // Return whether this dynamic symbol needs a special value in the
460 // dynamic symbol table.
462 needs_dynsym_value() const
463 { return this->needs_dynsym_value_; }
465 // Set that this dynamic symbol needs a special value in the dynamic
468 set_needs_dynsym_value()
470 gold_assert(this->object()->is_dynamic());
471 this->needs_dynsym_value_ = true;
474 // Return true if the final value of this symbol is known at link
477 final_value_is_known() const;
479 // Return true if SHNDX represents a common symbol. This depends on
482 is_common_shndx(unsigned int shndx);
484 // Return whether this is a defined symbol (not undefined or
490 if (this->source_ != FROM_OBJECT)
491 return this->source_ != IS_UNDEFINED;
492 unsigned int shndx = this->shndx(&is_ordinary);
494 ? shndx != elfcpp::SHN_UNDEF
495 : !Symbol::is_common_shndx(shndx));
498 // Return true if this symbol is from a dynamic object.
500 is_from_dynobj() const
502 return this->source_ == FROM_OBJECT && this->object()->is_dynamic();
505 // Return whether this is a placeholder symbol from a plugin object.
507 is_placeholder() const
509 return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL;
512 // Return whether this is an undefined symbol.
517 return ((this->source_ == FROM_OBJECT
518 && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF
520 || this->source_ == IS_UNDEFINED);
523 // Return whether this is a weak undefined symbol.
525 is_weak_undefined() const
527 return (this->is_undefined()
528 && (this->binding() == elfcpp::STB_WEAK
529 || this->is_undef_binding_weak()));
532 // Return whether this is a strong undefined symbol.
534 is_strong_undefined() const
536 return (this->is_undefined()
537 && this->binding() != elfcpp::STB_WEAK
538 && !this->is_undef_binding_weak());
541 // Return whether this is an absolute symbol.
546 return ((this->source_ == FROM_OBJECT
547 && this->shndx(&is_ordinary) == elfcpp::SHN_ABS
549 || this->source_ == IS_CONSTANT);
552 // Return whether this is a common symbol.
556 if (this->source_ != FROM_OBJECT)
558 if (this->type_ == elfcpp::STT_COMMON)
561 unsigned int shndx = this->shndx(&is_ordinary);
562 return !is_ordinary && Symbol::is_common_shndx(shndx);
565 // Return whether this symbol can be seen outside this object.
567 is_externally_visible() const
569 return ((this->visibility_ == elfcpp::STV_DEFAULT
570 || this->visibility_ == elfcpp::STV_PROTECTED)
571 && !this->is_forced_local_);
574 // Return true if this symbol can be preempted by a definition in
575 // another link unit.
577 is_preemptible() const
579 // It doesn't make sense to ask whether a symbol defined in
580 // another object is preemptible.
581 gold_assert(!this->is_from_dynobj());
583 // It doesn't make sense to ask whether an undefined symbol
585 gold_assert(!this->is_undefined());
587 // If a symbol does not have default visibility, it can not be
588 // seen outside this link unit and therefore is not preemptible.
589 if (this->visibility_ != elfcpp::STV_DEFAULT)
592 // If this symbol has been forced to be a local symbol by a
593 // version script, then it is not visible outside this link unit
594 // and is not preemptible.
595 if (this->is_forced_local_)
598 // If we are not producing a shared library, then nothing is
600 if (!parameters->options().shared())
603 // If the symbol was named in a --dynamic-list script, it is preemptible.
604 if (parameters->options().in_dynamic_list(this->name()))
607 // If the user used -Bsymbolic, then nothing (else) is preemptible.
608 if (parameters->options().Bsymbolic())
611 // If the user used -Bsymbolic-functions, then functions are not
612 // preemptible. We explicitly check for not being STT_OBJECT,
613 // rather than for being STT_FUNC, because that is what the GNU
615 if (this->type() != elfcpp::STT_OBJECT
616 && parameters->options().Bsymbolic_functions())
619 // Otherwise the symbol is preemptible.
623 // Return true if this symbol is a function that needs a PLT entry.
625 needs_plt_entry() const
627 // An undefined symbol from an executable does not need a PLT entry.
628 if (this->is_undefined() && !parameters->options().shared())
631 // An STT_GNU_IFUNC symbol always needs a PLT entry, even when
632 // doing a static link.
633 if (this->type() == elfcpp::STT_GNU_IFUNC)
636 // We only need a PLT entry for a function.
637 if (!this->is_func())
640 // If we're doing a static link or a -pie link, we don't create
642 if (parameters->doing_static_link()
643 || parameters->options().pie())
646 // We need a PLT entry if the function is defined in a dynamic
647 // object, or is undefined when building a shared object, or if it
648 // is subject to pre-emption.
649 return (this->is_from_dynobj()
650 || this->is_undefined()
651 || this->is_preemptible());
654 // When determining whether a reference to a symbol needs a dynamic
655 // relocation, we need to know several things about the reference.
656 // These flags may be or'ed together. 0 means that the symbol
657 // isn't referenced at all.
660 // A reference to the symbol's absolute address. This includes
661 // references that cause an absolute address to be stored in the GOT.
663 // A reference that calculates the offset of the symbol from some
664 // anchor point, such as the PC or GOT.
666 // A TLS-related reference.
668 // A reference that can always be treated as a function call.
670 // When set, says that dynamic relocations are needed even if a
671 // symbol has a plt entry.
675 // Given a direct absolute or pc-relative static relocation against
676 // the global symbol, this function returns whether a dynamic relocation
680 needs_dynamic_reloc(int flags) const
682 // No dynamic relocations in a static link!
683 if (parameters->doing_static_link())
686 // A reference to an undefined symbol from an executable should be
687 // statically resolved to 0, and does not need a dynamic relocation.
688 // This matches gnu ld behavior.
689 if (this->is_undefined() && !parameters->options().shared())
692 // A reference to an absolute symbol does not need a dynamic relocation.
693 if (this->is_absolute())
696 // An absolute reference within a position-independent output file
697 // will need a dynamic relocation.
698 if ((flags & ABSOLUTE_REF)
699 && parameters->options().output_is_position_independent())
702 // A function call that can branch to a local PLT entry does not need
703 // a dynamic relocation.
704 if ((flags & FUNCTION_CALL) && this->has_plt_offset())
707 // A reference to any PLT entry in a non-position-independent executable
708 // does not need a dynamic relocation.
709 if (!(flags & FUNC_DESC_ABI)
710 && !parameters->options().output_is_position_independent()
711 && this->has_plt_offset())
714 // A reference to a symbol defined in a dynamic object or to a
715 // symbol that is preemptible will need a dynamic relocation.
716 if (this->is_from_dynobj()
717 || this->is_undefined()
718 || this->is_preemptible())
721 // For all other cases, return FALSE.
725 // Whether we should use the PLT offset associated with a symbol for
726 // a relocation. FLAGS is a set of Reference_flags.
729 use_plt_offset(int flags) const
731 // If the symbol doesn't have a PLT offset, then naturally we
732 // don't want to use it.
733 if (!this->has_plt_offset())
736 // For a STT_GNU_IFUNC symbol we always have to use the PLT entry.
737 if (this->type() == elfcpp::STT_GNU_IFUNC)
740 // If we are going to generate a dynamic relocation, then we will
741 // wind up using that, so no need to use the PLT entry.
742 if (this->needs_dynamic_reloc(flags))
745 // If the symbol is from a dynamic object, we need to use the PLT
747 if (this->is_from_dynobj())
750 // If we are generating a shared object, and this symbol is
751 // undefined or preemptible, we need to use the PLT entry.
752 if (parameters->options().shared()
753 && (this->is_undefined() || this->is_preemptible()))
756 // If this is a call to a weak undefined symbol, we need to use
757 // the PLT entry; the symbol may be defined by a library loaded
759 if ((flags & FUNCTION_CALL) && this->is_weak_undefined())
762 // Otherwise we can use the regular definition.
766 // Given a direct absolute static relocation against
767 // the global symbol, where a dynamic relocation is needed, this
768 // function returns whether a relative dynamic relocation can be used.
769 // The caller must determine separately whether the static relocation
770 // is compatible with a relative relocation.
773 can_use_relative_reloc(bool is_function_call) const
775 // A function call that can branch to a local PLT entry can
776 // use a RELATIVE relocation.
777 if (is_function_call && this->has_plt_offset())
780 // A reference to a symbol defined in a dynamic object or to a
781 // symbol that is preemptible can not use a RELATIVE relocation.
782 if (this->is_from_dynobj()
783 || this->is_undefined()
784 || this->is_preemptible())
787 // For all other cases, return TRUE.
791 // Return the output section where this symbol is defined. Return
792 // NULL if the symbol has an absolute value.
794 output_section() const;
796 // Set the symbol's output section. This is used for symbols
797 // defined in scripts. This should only be called after the symbol
798 // table has been finalized.
800 set_output_section(Output_section*);
802 // Set the symbol's output segment. This is used for pre-defined
803 // symbols whose segments aren't known until after layout is done
804 // (e.g., __ehdr_start).
806 set_output_segment(Output_segment*, Segment_offset_base);
808 // Set the symbol to undefined. This is used for pre-defined
809 // symbols whose segments aren't known until after layout is done
810 // (e.g., __ehdr_start).
814 // Return whether there should be a warning for references to this
818 { return this->has_warning_; }
820 // Mark this symbol as having a warning.
823 { this->has_warning_ = true; }
825 // Return whether this symbol is defined by a COPY reloc from a
828 is_copied_from_dynobj() const
829 { return this->is_copied_from_dynobj_; }
831 // Mark this symbol as defined by a COPY reloc.
833 set_is_copied_from_dynobj()
834 { this->is_copied_from_dynobj_ = true; }
836 // Return whether this symbol is forced to visibility STB_LOCAL
837 // by a "local:" entry in a version script.
839 is_forced_local() const
840 { return this->is_forced_local_; }
842 // Mark this symbol as forced to STB_LOCAL visibility.
844 set_is_forced_local()
845 { this->is_forced_local_ = true; }
847 // Return true if this may need a COPY relocation.
848 // References from an executable object to non-function symbols
849 // defined in a dynamic object may need a COPY relocation.
851 may_need_copy_reloc() const
853 return (parameters->options().copyreloc()
854 && this->is_from_dynobj()
855 && !this->is_func());
858 // Return true if this symbol was predefined by the linker.
860 is_predefined() const
861 { return this->is_predefined_; }
863 // Return true if this is a C++ vtable symbol.
865 is_cxx_vtable() const
866 { return is_prefix_of("_ZTV", this->name_); }
869 // Instances of this class should always be created at a specific
872 { memset(this, 0, sizeof *this); }
874 // Initialize the general fields.
876 init_fields(const char* name, const char* version,
877 elfcpp::STT type, elfcpp::STB binding,
878 elfcpp::STV visibility, unsigned char nonvis);
880 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
881 // section index, IS_ORDINARY is whether it is a normal section
882 // index rather than a special code.
883 template<int size, bool big_endian>
885 init_base_object(const char* name, const char* version, Object* object,
886 const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
889 // Initialize fields for an Output_data.
891 init_base_output_data(const char* name, const char* version, Output_data*,
892 elfcpp::STT, elfcpp::STB, elfcpp::STV,
893 unsigned char nonvis, bool offset_is_from_end,
896 // Initialize fields for an Output_segment.
898 init_base_output_segment(const char* name, const char* version,
899 Output_segment* os, elfcpp::STT type,
900 elfcpp::STB binding, elfcpp::STV visibility,
901 unsigned char nonvis,
902 Segment_offset_base offset_base,
905 // Initialize fields for a constant.
907 init_base_constant(const char* name, const char* version, elfcpp::STT type,
908 elfcpp::STB binding, elfcpp::STV visibility,
909 unsigned char nonvis, bool is_predefined);
911 // Initialize fields for an undefined symbol.
913 init_base_undefined(const char* name, const char* version, elfcpp::STT type,
914 elfcpp::STB binding, elfcpp::STV visibility,
915 unsigned char nonvis);
917 // Override existing symbol.
918 template<int size, bool big_endian>
920 override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
921 bool is_ordinary, Object* object, const char* version);
923 // Override existing symbol with a special symbol.
925 override_base_with_special(const Symbol* from);
927 // Override symbol version.
929 override_version(const char* version);
931 // Allocate a common symbol by giving it a location in the output
934 allocate_base_common(Output_data*);
937 Symbol(const Symbol&);
938 Symbol& operator=(const Symbol&);
940 // Symbol name (expected to point into a Stringpool).
942 // Symbol version (expected to point into a Stringpool). This may
944 const char* version_;
948 // This struct is used if SOURCE_ == FROM_OBJECT.
951 // Object in which symbol is defined, or in which it was first
954 // Section number in object_ in which symbol is defined.
958 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
961 // Output_data in which symbol is defined. Before
962 // Layout::finalize the symbol's value is an offset within the
964 Output_data* output_data;
965 // True if the offset is from the end, false if the offset is
966 // from the beginning.
967 bool offset_is_from_end;
970 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
973 // Output_segment in which the symbol is defined. Before
974 // Layout::finalize the symbol's value is an offset.
975 Output_segment* output_segment;
976 // The base to use for the offset before Layout::finalize.
977 Segment_offset_base offset_base;
981 // The index of this symbol in the output file. If the symbol is
982 // not going into the output file, this value is -1U. This field
983 // starts as always holding zero. It is set to a non-zero value by
984 // Symbol_table::finalize.
985 unsigned int symtab_index_;
987 // The index of this symbol in the dynamic symbol table. If the
988 // symbol is not going into the dynamic symbol table, this value is
989 // -1U. This field starts as always holding zero. It is set to a
990 // non-zero value during Layout::finalize.
991 unsigned int dynsym_index_;
993 // The GOT section entries for this symbol. A symbol may have more
994 // than one GOT offset (e.g., when mixing modules compiled with two
995 // different TLS models), but will usually have at most one.
996 Got_offset_list got_offsets_;
998 // If this symbol has an entry in the PLT section, then this is the
999 // offset from the start of the PLT section. This is -1U if there
1001 unsigned int plt_offset_;
1003 // Symbol type (bits 0 to 3).
1004 elfcpp::STT type_ : 4;
1005 // Symbol binding (bits 4 to 7).
1006 elfcpp::STB binding_ : 4;
1007 // Symbol visibility (bits 8 to 9).
1008 elfcpp::STV visibility_ : 2;
1009 // Rest of symbol st_other field (bits 10 to 15).
1010 unsigned int nonvis_ : 6;
1011 // The type of symbol (bits 16 to 18).
1013 // True if this is the default version of the symbol (bit 19).
1015 // True if this symbol really forwards to another symbol. This is
1016 // used when we discover after the fact that two different entries
1017 // in the hash table really refer to the same symbol. This will
1018 // never be set for a symbol found in the hash table, but may be set
1019 // for a symbol found in the list of symbols attached to an Object.
1020 // It forwards to the symbol found in the forwarders_ map of
1021 // Symbol_table (bit 20).
1022 bool is_forwarder_ : 1;
1023 // True if the symbol has an alias in the weak_aliases table in
1024 // Symbol_table (bit 21).
1025 bool has_alias_ : 1;
1026 // True if this symbol needs to be in the dynamic symbol table (bit
1028 bool needs_dynsym_entry_ : 1;
1029 // True if we've seen this symbol in a regular object (bit 23).
1031 // True if we've seen this symbol in a dynamic object (bit 24).
1033 // True if this is a dynamic symbol which needs a special value in
1034 // the dynamic symbol table (bit 25).
1035 bool needs_dynsym_value_ : 1;
1036 // True if there is a warning for this symbol (bit 26).
1037 bool has_warning_ : 1;
1038 // True if we are using a COPY reloc for this symbol, so that the
1039 // real definition lives in a dynamic object (bit 27).
1040 bool is_copied_from_dynobj_ : 1;
1041 // True if this symbol was forced to local visibility by a version
1043 bool is_forced_local_ : 1;
1044 // True if the field u_.from_object.shndx is an ordinary section
1045 // index, not one of the special codes from SHN_LORESERVE to
1046 // SHN_HIRESERVE (bit 29).
1047 bool is_ordinary_shndx_ : 1;
1048 // True if we've seen this symbol in a "real" ELF object (bit 30).
1049 // If the symbol has been seen in a relocatable, non-IR, object file,
1050 // it's known to be referenced from outside the IR. A reference from
1051 // a dynamic object doesn't count as a "real" ELF, and we'll simply
1052 // mark the symbol as "visible" from outside the IR. The compiler
1053 // can use this distinction to guide its handling of COMDAT symbols.
1054 bool in_real_elf_ : 1;
1055 // True if this symbol is defined in a section which was discarded
1057 bool is_defined_in_discarded_section_ : 1;
1058 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
1059 bool undef_binding_set_ : 1;
1060 // True if this symbol was a weak undef resolved by a dynamic def
1061 // or by a special symbol (bit 33).
1062 bool undef_binding_weak_ : 1;
1063 // True if this symbol is a predefined linker symbol (bit 34).
1064 bool is_predefined_ : 1;
1067 // The parts of a symbol which are size specific. Using a template
1068 // derived class like this helps us use less space on a 32-bit system.
1071 class Sized_symbol : public Symbol
1074 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type;
1075 typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type;
1080 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
1081 // section index, IS_ORDINARY is whether it is a normal section
1082 // index rather than a special code.
1083 template<bool big_endian>
1085 init_object(const char* name, const char* version, Object* object,
1086 const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
1089 // Initialize fields for an Output_data.
1091 init_output_data(const char* name, const char* version, Output_data*,
1092 Value_type value, Size_type symsize, elfcpp::STT,
1093 elfcpp::STB, elfcpp::STV, unsigned char nonvis,
1094 bool offset_is_from_end, bool is_predefined);
1096 // Initialize fields for an Output_segment.
1098 init_output_segment(const char* name, const char* version, Output_segment*,
1099 Value_type value, Size_type symsize, elfcpp::STT,
1100 elfcpp::STB, elfcpp::STV, unsigned char nonvis,
1101 Segment_offset_base offset_base, bool is_predefined);
1103 // Initialize fields for a constant.
1105 init_constant(const char* name, const char* version, Value_type value,
1106 Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV,
1107 unsigned char nonvis, bool is_predefined);
1109 // Initialize fields for an undefined symbol.
1111 init_undefined(const char* name, const char* version, elfcpp::STT,
1112 elfcpp::STB, elfcpp::STV, unsigned char nonvis);
1114 // Override existing symbol.
1115 template<bool big_endian>
1117 override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
1118 bool is_ordinary, Object* object, const char* version);
1120 // Override existing symbol with a special symbol.
1122 override_with_special(const Sized_symbol<size>*);
1124 // Return the symbol's value.
1127 { return this->value_; }
1129 // Return the symbol's size (we can't call this 'size' because that
1130 // is a template parameter).
1133 { return this->symsize_; }
1135 // Set the symbol size. This is used when resolving common symbols.
1137 set_symsize(Size_type symsize)
1138 { this->symsize_ = symsize; }
1140 // Set the symbol value. This is called when we store the final
1141 // values of the symbols into the symbol table.
1143 set_value(Value_type value)
1144 { this->value_ = value; }
1146 // Allocate a common symbol by giving it a location in the output
1149 allocate_common(Output_data*, Value_type value);
1152 Sized_symbol(const Sized_symbol&);
1153 Sized_symbol& operator=(const Sized_symbol&);
1155 // Symbol value. Before Layout::finalize this is the offset in the
1156 // input section. This is set to the final value during
1157 // Layout::finalize.
1163 // A struct describing a symbol defined by the linker, where the value
1164 // of the symbol is defined based on an output section. This is used
1165 // for symbols defined by the linker, like "_init_array_start".
1167 struct Define_symbol_in_section
1171 // The name of the output section with which this symbol should be
1172 // associated. If there is no output section with that name, the
1173 // symbol will be defined as zero.
1174 const char* output_section;
1175 // The offset of the symbol within the output section. This is an
1176 // offset from the start of the output section, unless start_at_end
1177 // is true, in which case this is an offset from the end of the
1180 // The size of the symbol.
1184 // The symbol binding.
1185 elfcpp::STB binding;
1186 // The symbol visibility.
1187 elfcpp::STV visibility;
1188 // The rest of the st_other field.
1189 unsigned char nonvis;
1190 // If true, the value field is an offset from the end of the output
1192 bool offset_is_from_end;
1193 // If true, this symbol is defined only if we see a reference to it.
1197 // A struct describing a symbol defined by the linker, where the value
1198 // of the symbol is defined based on a segment. This is used for
1199 // symbols defined by the linker, like "_end". We describe the
1200 // segment with which the symbol should be associated by its
1201 // characteristics. If no segment meets these characteristics, the
1202 // symbol will be defined as zero. If there is more than one segment
1203 // which meets these characteristics, we will use the first one.
1205 struct Define_symbol_in_segment
1209 // The segment type where the symbol should be defined, typically
1211 elfcpp::PT segment_type;
1212 // Bitmask of segment flags which must be set.
1213 elfcpp::PF segment_flags_set;
1214 // Bitmask of segment flags which must be clear.
1215 elfcpp::PF segment_flags_clear;
1216 // The offset of the symbol within the segment. The offset is
1217 // calculated from the position set by offset_base.
1219 // The size of the symbol.
1223 // The symbol binding.
1224 elfcpp::STB binding;
1225 // The symbol visibility.
1226 elfcpp::STV visibility;
1227 // The rest of the st_other field.
1228 unsigned char nonvis;
1229 // The base from which we compute the offset.
1230 Symbol::Segment_offset_base offset_base;
1231 // If true, this symbol is defined only if we see a reference to it.
1235 // Specify an object/section/offset location. Used by ODR code.
1237 struct Symbol_location
1239 // Object where the symbol is defined.
1241 // Section-in-object where the symbol is defined.
1243 // For relocatable objects, offset-in-section where the symbol is defined.
1244 // For dynamic objects, address where the symbol is defined.
1246 bool operator==(const Symbol_location& that) const
1248 return (this->object == that.object
1249 && this->shndx == that.shndx
1250 && this->offset == that.offset);
1254 // This class manages warnings. Warnings are a GNU extension. When
1255 // we see a section named .gnu.warning.SYM in an object file, and if
1256 // we wind using the definition of SYM from that object file, then we
1257 // will issue a warning for any relocation against SYM from a
1258 // different object file. The text of the warning is the contents of
1259 // the section. This is not precisely the definition used by the old
1260 // GNU linker; the old GNU linker treated an occurrence of
1261 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1262 // would trigger a warning on any reference. However, it was
1263 // inconsistent in that a warning in a dynamic object only triggered
1264 // if there was no definition in a regular object. This linker is
1265 // different in that we only issue a warning if we use the symbol
1266 // definition from the same object file as the warning section.
1275 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1278 add_warning(Symbol_table* symtab, const char* name, Object* obj,
1279 const std::string& warning);
1281 // For each symbol for which we should give a warning, make a note
1284 note_warnings(Symbol_table* symtab);
1286 // Issue a warning for a reference to SYM at RELINFO's location.
1287 template<int size, bool big_endian>
1289 issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*,
1290 size_t relnum, off_t reloffset) const;
1293 Warnings(const Warnings&);
1294 Warnings& operator=(const Warnings&);
1296 // What we need to know to get the warning text.
1297 struct Warning_location
1299 // The object the warning is in.
1301 // The warning text.
1305 : object(NULL), text()
1309 set(Object* o, const std::string& t)
1316 // A mapping from warning symbol names (canonicalized in
1317 // Symbol_table's namepool_ field) to warning information.
1318 typedef Unordered_map<const char*, Warning_location> Warning_table;
1320 Warning_table warnings_;
1323 // The main linker symbol table.
1328 // The different places where a symbol definition can come from.
1331 // Defined in an object file--the normal case.
1333 // Defined for a COPY reloc.
1335 // Defined on the command line using --defsym.
1337 // Defined (so to speak) on the command line using -u.
1339 // Defined in a linker script.
1341 // Predefined by the linker.
1343 // Defined by the linker during an incremental base link, but not
1344 // a predefined symbol (e.g., common, defined in script).
1348 // The order in which we sort common symbols.
1349 enum Sort_commons_order
1351 SORT_COMMONS_BY_SIZE_DESCENDING,
1352 SORT_COMMONS_BY_ALIGNMENT_DESCENDING,
1353 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1356 // COUNT is an estimate of how many symbols will be inserted in the
1357 // symbol table. It's ok to put 0 if you don't know; a correct
1358 // guess will just save some CPU by reducing hashtable resizes.
1359 Symbol_table(unsigned int count, const Version_script_info& version_script);
1365 { this->icf_ = icf;}
1369 { return this->icf_; }
1371 // Returns true if ICF determined that this is a duplicate section.
1373 is_section_folded(Object* obj, unsigned int shndx) const;
1376 set_gc(Garbage_collection* gc)
1381 { return this->gc_; }
1383 // During garbage collection, this keeps undefined symbols.
1385 gc_mark_undef_symbols(Layout*);
1387 // This tells garbage collection that this symbol is referenced.
1389 gc_mark_symbol(Symbol* sym);
1391 // During garbage collection, this keeps sections that correspond to
1392 // symbols seen in dynamic objects.
1394 gc_mark_dyn_syms(Symbol* sym);
1396 // Add COUNT external symbols from the relocatable object RELOBJ to
1397 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1398 // offset in the symbol table of the first symbol, SYM_NAMES is
1399 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1400 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1401 // *DEFINED to the number of defined symbols.
1402 template<int size, bool big_endian>
1404 add_from_relobj(Sized_relobj_file<size, big_endian>* relobj,
1405 const unsigned char* syms, size_t count,
1406 size_t symndx_offset, const char* sym_names,
1407 size_t sym_name_size,
1408 typename Sized_relobj_file<size, big_endian>::Symbols*,
1411 // Add one external symbol from the plugin object OBJ to the symbol table.
1412 // Returns a pointer to the resolved symbol in the symbol table.
1413 template<int size, bool big_endian>
1415 add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj,
1416 const char* name, const char* ver,
1417 elfcpp::Sym<size, big_endian>* sym);
1419 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1420 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1421 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1422 // symbol version data.
1423 template<int size, bool big_endian>
1425 add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj,
1426 const unsigned char* syms, size_t count,
1427 const char* sym_names, size_t sym_name_size,
1428 const unsigned char* versym, size_t versym_size,
1429 const std::vector<const char*>*,
1430 typename Sized_relobj_file<size, big_endian>::Symbols*,
1433 // Add one external symbol from the incremental object OBJ to the symbol
1434 // table. Returns a pointer to the resolved symbol in the symbol table.
1435 template<int size, bool big_endian>
1437 add_from_incrobj(Object* obj, const char* name,
1438 const char* ver, elfcpp::Sym<size, big_endian>* sym);
1440 // Define a special symbol based on an Output_data. It is a
1441 // multiple definition error if this symbol is already defined.
1443 define_in_output_data(const char* name, const char* version, Defined,
1444 Output_data*, uint64_t value, uint64_t symsize,
1445 elfcpp::STT type, elfcpp::STB binding,
1446 elfcpp::STV visibility, unsigned char nonvis,
1447 bool offset_is_from_end, bool only_if_ref);
1449 // Define a special symbol based on an Output_segment. It is a
1450 // multiple definition error if this symbol is already defined.
1452 define_in_output_segment(const char* name, const char* version, Defined,
1453 Output_segment*, uint64_t value, uint64_t symsize,
1454 elfcpp::STT type, elfcpp::STB binding,
1455 elfcpp::STV visibility, unsigned char nonvis,
1456 Symbol::Segment_offset_base, bool only_if_ref);
1458 // Define a special symbol with a constant value. It is a multiple
1459 // definition error if this symbol is already defined.
1461 define_as_constant(const char* name, const char* version, Defined,
1462 uint64_t value, uint64_t symsize, elfcpp::STT type,
1463 elfcpp::STB binding, elfcpp::STV visibility,
1464 unsigned char nonvis, bool only_if_ref,
1465 bool force_override);
1467 // Define a set of symbols in output sections. If ONLY_IF_REF is
1468 // true, only define them if they are referenced.
1470 define_symbols(const Layout*, int count, const Define_symbol_in_section*,
1473 // Define a set of symbols in output segments. If ONLY_IF_REF is
1474 // true, only defined them if they are referenced.
1476 define_symbols(const Layout*, int count, const Define_symbol_in_segment*,
1479 // Define SYM using a COPY reloc. POSD is the Output_data where the
1480 // symbol should be defined--typically a .dyn.bss section. VALUE is
1481 // the offset within POSD.
1484 define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd,
1485 typename elfcpp::Elf_types<size>::Elf_Addr);
1487 // Look up a symbol.
1489 lookup(const char*, const char* version = NULL) const;
1491 // Return the real symbol associated with the forwarder symbol FROM.
1493 resolve_forwards(const Symbol* from) const;
1495 // Return the sized version of a symbol in this table.
1498 get_sized_symbol(Symbol*) const;
1501 const Sized_symbol<size>*
1502 get_sized_symbol(const Symbol*) const;
1504 // Return the count of undefined symbols seen.
1506 saw_undefined() const
1507 { return this->saw_undefined_; }
1509 // Allocate the common symbols
1511 allocate_commons(Layout*, Mapfile*);
1513 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1516 add_warning(const char* name, Object* obj, const std::string& warning)
1517 { this->warnings_.add_warning(this, name, obj, warning); }
1519 // Canonicalize a symbol name for use in the hash table.
1521 canonicalize_name(const char* name)
1522 { return this->namepool_.add(name, true, NULL); }
1524 // Possibly issue a warning for a reference to SYM at LOCATION which
1526 template<int size, bool big_endian>
1528 issue_warning(const Symbol* sym,
1529 const Relocate_info<size, big_endian>* relinfo,
1530 size_t relnum, off_t reloffset) const
1531 { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); }
1533 // Check candidate_odr_violations_ to find symbols with the same name
1534 // but apparently different definitions (different source-file/line-no).
1536 detect_odr_violations(const Task*, const char* output_file_name) const;
1538 // Add any undefined symbols named on the command line to the symbol
1541 add_undefined_symbols_from_command_line(Layout*);
1543 // SYM is defined using a COPY reloc. Return the dynamic object
1544 // where the original definition was found.
1546 get_copy_source(const Symbol* sym) const;
1548 // Set the dynamic symbol indexes. INDEX is the index of the first
1549 // global dynamic symbol. Pointers to the symbols are stored into
1550 // the vector. The names are stored into the Stringpool. This
1551 // returns an updated dynamic symbol index.
1553 set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*,
1554 Stringpool*, Versions*);
1556 // Finalize the symbol table after we have set the final addresses
1557 // of all the input sections. This sets the final symbol indexes,
1558 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1559 // index of the first global symbol. OFF is the file offset of the
1560 // global symbol table, DYNOFF is the offset of the globals in the
1561 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1562 // global dynamic symbol, and DYNCOUNT is the number of global
1563 // dynamic symbols. This records the parameters, and returns the
1564 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1567 finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount,
1568 Stringpool* pool, unsigned int* plocal_symcount);
1570 // Set the final file offset of the symbol table.
1572 set_file_offset(off_t off)
1573 { this->offset_ = off; }
1575 // Status code of Symbol_table::compute_final_value.
1576 enum Compute_final_value_status
1580 // Unsupported symbol section.
1581 CFVS_UNSUPPORTED_SYMBOL_SECTION,
1582 // No output section.
1583 CFVS_NO_OUTPUT_SECTION
1586 // Compute the final value of SYM and store status in location PSTATUS.
1587 // During relaxation, this may be called multiple times for a symbol to
1588 // compute its would-be final value in each relaxation pass.
1591 typename Sized_symbol<size>::Value_type
1592 compute_final_value(const Sized_symbol<size>* sym,
1593 Compute_final_value_status* pstatus) const;
1595 // Return the index of the first global symbol.
1597 first_global_index() const
1598 { return this->first_global_index_; }
1600 // Return the total number of symbols in the symbol table.
1602 output_count() const
1603 { return this->output_count_; }
1605 // Write out the global symbols.
1607 write_globals(const Stringpool*, const Stringpool*,
1608 Output_symtab_xindex*, Output_symtab_xindex*,
1609 Output_file*) const;
1611 // Write out a section symbol. Return the updated offset.
1613 write_section_symbol(const Output_section*, Output_symtab_xindex*,
1614 Output_file*, off_t) const;
1616 // Loop over all symbols, applying the function F to each.
1617 template<int size, typename F>
1619 for_all_symbols(F f) const
1621 for (Symbol_table_type::const_iterator p = this->table_.begin();
1622 p != this->table_.end();
1625 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1630 // Dump statistical information to stderr.
1632 print_stats() const;
1634 // Return the version script information.
1635 const Version_script_info&
1636 version_script() const
1637 { return version_script_; }
1640 Symbol_table(const Symbol_table&);
1641 Symbol_table& operator=(const Symbol_table&);
1643 // The type of the list of common symbols.
1644 typedef std::vector<Symbol*> Commons_type;
1646 // The type of the symbol hash table.
1648 typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
1650 // The hash function. The key values are Stringpool keys.
1651 struct Symbol_table_hash
1654 operator()(const Symbol_table_key& key) const
1656 return key.first ^ key.second;
1660 struct Symbol_table_eq
1663 operator()(const Symbol_table_key&, const Symbol_table_key&) const;
1666 typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
1667 Symbol_table_eq> Symbol_table_type;
1669 // A map from symbol name (as a pointer into the namepool) to all
1670 // the locations the symbols is (weakly) defined (and certain other
1671 // conditions are met). This map will be used later to detect
1672 // possible One Definition Rule (ODR) violations.
1673 struct Symbol_location_hash
1675 size_t operator()(const Symbol_location& loc) const
1676 { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; }
1679 typedef Unordered_map<const char*,
1680 Unordered_set<Symbol_location, Symbol_location_hash> >
1683 // Make FROM a forwarder symbol to TO.
1685 make_forwarder(Symbol* from, Symbol* to);
1688 template<int size, bool big_endian>
1690 add_from_object(Object*, const char* name, Stringpool::Key name_key,
1691 const char* version, Stringpool::Key version_key,
1692 bool def, const elfcpp::Sym<size, big_endian>& sym,
1693 unsigned int st_shndx, bool is_ordinary,
1694 unsigned int orig_st_shndx);
1696 // Define a default symbol.
1697 template<int size, bool big_endian>
1699 define_default_version(Sized_symbol<size>*, bool,
1700 Symbol_table_type::iterator);
1703 template<int size, bool big_endian>
1705 resolve(Sized_symbol<size>* to,
1706 const elfcpp::Sym<size, big_endian>& sym,
1707 unsigned int st_shndx, bool is_ordinary,
1708 unsigned int orig_st_shndx,
1709 Object*, const char* version);
1711 template<int size, bool big_endian>
1713 resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from);
1715 // Record that a symbol is forced to be local by a version script or
1718 force_local(Symbol*);
1720 // Adjust NAME and *NAME_KEY for wrapping.
1722 wrap_symbol(const char* name, Stringpool::Key* name_key);
1724 // Whether we should override a symbol, based on flags in
1727 should_override(const Symbol*, unsigned int, elfcpp::STT, Defined,
1728 Object*, bool*, bool*);
1730 // Report a problem in symbol resolution.
1732 report_resolve_problem(bool is_error, const char* msg, const Symbol* to,
1733 Defined, Object* object);
1735 // Override a symbol.
1736 template<int size, bool big_endian>
1738 override(Sized_symbol<size>* tosym,
1739 const elfcpp::Sym<size, big_endian>& fromsym,
1740 unsigned int st_shndx, bool is_ordinary,
1741 Object* object, const char* version);
1743 // Whether we should override a symbol with a special symbol which
1744 // is automatically defined by the linker.
1746 should_override_with_special(const Symbol*, elfcpp::STT, Defined);
1748 // Override a symbol with a special symbol.
1751 override_with_special(Sized_symbol<size>* tosym,
1752 const Sized_symbol<size>* fromsym);
1754 // Record all weak alias sets for a dynamic object.
1757 record_weak_aliases(std::vector<Sized_symbol<size>*>*);
1759 // Define a special symbol.
1760 template<int size, bool big_endian>
1762 define_special_symbol(const char** pname, const char** pversion,
1763 bool only_if_ref, Sized_symbol<size>** poldsym,
1764 bool* resolve_oldsym);
1766 // Define a symbol in an Output_data, sized version.
1769 do_define_in_output_data(const char* name, const char* version, Defined,
1771 typename elfcpp::Elf_types<size>::Elf_Addr value,
1772 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1773 elfcpp::STT type, elfcpp::STB binding,
1774 elfcpp::STV visibility, unsigned char nonvis,
1775 bool offset_is_from_end, bool only_if_ref);
1777 // Define a symbol in an Output_segment, sized version.
1780 do_define_in_output_segment(
1781 const char* name, const char* version, Defined, Output_segment* os,
1782 typename elfcpp::Elf_types<size>::Elf_Addr value,
1783 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1784 elfcpp::STT type, elfcpp::STB binding,
1785 elfcpp::STV visibility, unsigned char nonvis,
1786 Symbol::Segment_offset_base offset_base, bool only_if_ref);
1788 // Define a symbol as a constant, sized version.
1791 do_define_as_constant(
1792 const char* name, const char* version, Defined,
1793 typename elfcpp::Elf_types<size>::Elf_Addr value,
1794 typename elfcpp::Elf_types<size>::Elf_WXword ssize,
1795 elfcpp::STT type, elfcpp::STB binding,
1796 elfcpp::STV visibility, unsigned char nonvis,
1797 bool only_if_ref, bool force_override);
1799 // Add any undefined symbols named on the command line to the symbol
1800 // table, sized version.
1803 do_add_undefined_symbols_from_command_line(Layout*);
1805 // Add one undefined symbol.
1808 add_undefined_symbol_from_command_line(const char* name);
1810 // Types of common symbols.
1812 enum Commons_section_type
1820 // Allocate the common symbols, sized version.
1823 do_allocate_commons(Layout*, Mapfile*, Sort_commons_order);
1825 // Allocate the common symbols from one list.
1828 do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*,
1829 Mapfile*, Sort_commons_order);
1831 // Returns all of the lines attached to LOC, not just the one the
1832 // instruction actually came from. This helps the ODR checker avoid
1834 static std::vector<std::string>
1835 linenos_from_loc(const Task* task, const Symbol_location& loc);
1837 // Implement detect_odr_violations.
1838 template<int size, bool big_endian>
1840 sized_detect_odr_violations() const;
1842 // Finalize symbols specialized for size.
1845 sized_finalize(off_t, Stringpool*, unsigned int*);
1847 // Finalize a symbol. Return whether it should be added to the
1851 sized_finalize_symbol(Symbol*);
1853 // Add a symbol the final symtab by setting its index.
1856 add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff);
1858 // Write globals specialized for size and endianness.
1859 template<int size, bool big_endian>
1861 sized_write_globals(const Stringpool*, const Stringpool*,
1862 Output_symtab_xindex*, Output_symtab_xindex*,
1863 Output_file*) const;
1865 // Write out a symbol to P.
1866 template<int size, bool big_endian>
1868 sized_write_symbol(Sized_symbol<size>*,
1869 typename elfcpp::Elf_types<size>::Elf_Addr value,
1870 unsigned int shndx, elfcpp::STB,
1871 const Stringpool*, unsigned char* p) const;
1873 // Possibly warn about an undefined symbol from a dynamic object.
1875 warn_about_undefined_dynobj_symbol(Symbol*) const;
1877 // Write out a section symbol, specialized for size and endianness.
1878 template<int size, bool big_endian>
1880 sized_write_section_symbol(const Output_section*, Output_symtab_xindex*,
1881 Output_file*, off_t) const;
1883 // The type of the list of symbols which have been forced local.
1884 typedef std::vector<Symbol*> Forced_locals;
1886 // A map from symbols with COPY relocs to the dynamic objects where
1887 // they are defined.
1888 typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs;
1890 // We increment this every time we see a new undefined symbol, for
1891 // use in archive groups.
1892 size_t saw_undefined_;
1893 // The index of the first global symbol in the output file.
1894 unsigned int first_global_index_;
1895 // The file offset within the output symtab section where we should
1898 // The number of global symbols we want to write out.
1899 unsigned int output_count_;
1900 // The file offset of the global dynamic symbols, or 0 if none.
1901 off_t dynamic_offset_;
1902 // The index of the first global dynamic symbol.
1903 unsigned int first_dynamic_global_index_;
1904 // The number of global dynamic symbols, or 0 if none.
1905 unsigned int dynamic_count_;
1906 // The symbol hash table.
1907 Symbol_table_type table_;
1908 // A pool of symbol names. This is used for all global symbols.
1909 // Entries in the hash table point into this pool.
1910 Stringpool namepool_;
1911 // Forwarding symbols.
1912 Unordered_map<const Symbol*, Symbol*> forwarders_;
1913 // Weak aliases. A symbol in this list points to the next alias.
1914 // The aliases point to each other in a circular list.
1915 Unordered_map<Symbol*, Symbol*> weak_aliases_;
1916 // We don't expect there to be very many common symbols, so we keep
1917 // a list of them. When we find a common symbol we add it to this
1918 // list. It is possible that by the time we process the list the
1919 // symbol is no longer a common symbol. It may also have become a
1921 Commons_type commons_;
1922 // This is like the commons_ field, except that it holds TLS common
1924 Commons_type tls_commons_;
1925 // This is for small common symbols.
1926 Commons_type small_commons_;
1927 // This is for large common symbols.
1928 Commons_type large_commons_;
1929 // A list of symbols which have been forced to be local. We don't
1930 // expect there to be very many of them, so we keep a list of them
1931 // rather than walking the whole table to find them.
1932 Forced_locals forced_locals_;
1933 // Manage symbol warnings.
1935 // Manage potential One Definition Rule (ODR) violations.
1936 Odr_map candidate_odr_violations_;
1938 // When we emit a COPY reloc for a symbol, we define it in an
1939 // Output_data. When it's time to emit version information for it,
1940 // we need to know the dynamic object in which we found the original
1941 // definition. This maps symbols with COPY relocs to the dynamic
1942 // object where they were defined.
1943 Copied_symbol_dynobjs copied_symbol_dynobjs_;
1944 // Information parsed from the version script, if any.
1945 const Version_script_info& version_script_;
1946 Garbage_collection* gc_;
1950 // We inline get_sized_symbol for efficiency.
1954 Symbol_table::get_sized_symbol(Symbol* sym) const
1956 gold_assert(size == parameters->target().get_size());
1957 return static_cast<Sized_symbol<size>*>(sym);
1961 const Sized_symbol<size>*
1962 Symbol_table::get_sized_symbol(const Symbol* sym) const
1964 gold_assert(size == parameters->target().get_size());
1965 return static_cast<const Sized_symbol<size>*>(sym);
1968 } // End namespace gold.
1970 #endif // !defined(GOLD_SYMTAB_H)