1 // symtab.h -- the gold symbol table -*- C++ -*-
3 // Copyright (C) 2006-2014 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 or provided a --dynamic-list script,
608 // then nothing (else) is preemptible.
609 if (parameters
->options().Bsymbolic()
610 || parameters
->options().have_dynamic_list())
613 // If the user used -Bsymbolic-functions, then functions are not
614 // preemptible. We explicitly check for not being STT_OBJECT,
615 // rather than for being STT_FUNC, because that is what the GNU
617 if (this->type() != elfcpp::STT_OBJECT
618 && parameters
->options().Bsymbolic_functions())
621 // Otherwise the symbol is preemptible.
625 // Return true if this symbol is a function that needs a PLT entry.
627 needs_plt_entry() const
629 // An undefined symbol from an executable does not need a PLT entry.
630 if (this->is_undefined() && !parameters
->options().shared())
633 // An STT_GNU_IFUNC symbol always needs a PLT entry, even when
634 // doing a static link.
635 if (this->type() == elfcpp::STT_GNU_IFUNC
)
638 // We only need a PLT entry for a function.
639 if (!this->is_func())
642 // If we're doing a static link or a -pie link, we don't create
644 if (parameters
->doing_static_link()
645 || parameters
->options().pie())
648 // We need a PLT entry if the function is defined in a dynamic
649 // object, or is undefined when building a shared object, or if it
650 // is subject to pre-emption.
651 return (this->is_from_dynobj()
652 || this->is_undefined()
653 || this->is_preemptible());
656 // When determining whether a reference to a symbol needs a dynamic
657 // relocation, we need to know several things about the reference.
658 // These flags may be or'ed together. 0 means that the symbol
659 // isn't referenced at all.
662 // A reference to the symbol's absolute address. This includes
663 // references that cause an absolute address to be stored in the GOT.
665 // A reference that calculates the offset of the symbol from some
666 // anchor point, such as the PC or GOT.
668 // A TLS-related reference.
670 // A reference that can always be treated as a function call.
672 // When set, says that dynamic relocations are needed even if a
673 // symbol has a plt entry.
677 // Given a direct absolute or pc-relative static relocation against
678 // the global symbol, this function returns whether a dynamic relocation
682 needs_dynamic_reloc(int flags
) const
684 // No dynamic relocations in a static link!
685 if (parameters
->doing_static_link())
688 // A reference to an undefined symbol from an executable should be
689 // statically resolved to 0, and does not need a dynamic relocation.
690 // This matches gnu ld behavior.
691 if (this->is_undefined() && !parameters
->options().shared())
694 // A reference to an absolute symbol does not need a dynamic relocation.
695 if (this->is_absolute())
698 // An absolute reference within a position-independent output file
699 // will need a dynamic relocation.
700 if ((flags
& ABSOLUTE_REF
)
701 && parameters
->options().output_is_position_independent())
704 // A function call that can branch to a local PLT entry does not need
705 // a dynamic relocation.
706 if ((flags
& FUNCTION_CALL
) && this->has_plt_offset())
709 // A reference to any PLT entry in a non-position-independent executable
710 // does not need a dynamic relocation.
711 if (!(flags
& FUNC_DESC_ABI
)
712 && !parameters
->options().output_is_position_independent()
713 && this->has_plt_offset())
716 // A reference to a symbol defined in a dynamic object or to a
717 // symbol that is preemptible will need a dynamic relocation.
718 if (this->is_from_dynobj()
719 || this->is_undefined()
720 || this->is_preemptible())
723 // For all other cases, return FALSE.
727 // Whether we should use the PLT offset associated with a symbol for
728 // a relocation. FLAGS is a set of Reference_flags.
731 use_plt_offset(int flags
) const
733 // If the symbol doesn't have a PLT offset, then naturally we
734 // don't want to use it.
735 if (!this->has_plt_offset())
738 // For a STT_GNU_IFUNC symbol we always have to use the PLT entry.
739 if (this->type() == elfcpp::STT_GNU_IFUNC
)
742 // If we are going to generate a dynamic relocation, then we will
743 // wind up using that, so no need to use the PLT entry.
744 if (this->needs_dynamic_reloc(flags
))
747 // If the symbol is from a dynamic object, we need to use the PLT
749 if (this->is_from_dynobj())
752 // If we are generating a shared object, and this symbol is
753 // undefined or preemptible, we need to use the PLT entry.
754 if (parameters
->options().shared()
755 && (this->is_undefined() || this->is_preemptible()))
758 // If this is a call to a weak undefined symbol, we need to use
759 // the PLT entry; the symbol may be defined by a library loaded
761 if ((flags
& FUNCTION_CALL
) && this->is_weak_undefined())
764 // Otherwise we can use the regular definition.
768 // Given a direct absolute static relocation against
769 // the global symbol, where a dynamic relocation is needed, this
770 // function returns whether a relative dynamic relocation can be used.
771 // The caller must determine separately whether the static relocation
772 // is compatible with a relative relocation.
775 can_use_relative_reloc(bool is_function_call
) const
777 // A function call that can branch to a local PLT entry can
778 // use a RELATIVE relocation.
779 if (is_function_call
&& this->has_plt_offset())
782 // A reference to a symbol defined in a dynamic object or to a
783 // symbol that is preemptible can not use a RELATIVE relocation.
784 if (this->is_from_dynobj()
785 || this->is_undefined()
786 || this->is_preemptible())
789 // For all other cases, return TRUE.
793 // Return the output section where this symbol is defined. Return
794 // NULL if the symbol has an absolute value.
796 output_section() const;
798 // Set the symbol's output section. This is used for symbols
799 // defined in scripts. This should only be called after the symbol
800 // table has been finalized.
802 set_output_section(Output_section
*);
804 // Set the symbol's output segment. This is used for pre-defined
805 // symbols whose segments aren't known until after layout is done
806 // (e.g., __ehdr_start).
808 set_output_segment(Output_segment
*, Segment_offset_base
);
810 // Set the symbol to undefined. This is used for pre-defined
811 // symbols whose segments aren't known until after layout is done
812 // (e.g., __ehdr_start).
816 // Return whether there should be a warning for references to this
820 { return this->has_warning_
; }
822 // Mark this symbol as having a warning.
825 { this->has_warning_
= true; }
827 // Return whether this symbol is defined by a COPY reloc from a
830 is_copied_from_dynobj() const
831 { return this->is_copied_from_dynobj_
; }
833 // Mark this symbol as defined by a COPY reloc.
835 set_is_copied_from_dynobj()
836 { this->is_copied_from_dynobj_
= true; }
838 // Return whether this symbol is forced to visibility STB_LOCAL
839 // by a "local:" entry in a version script.
841 is_forced_local() const
842 { return this->is_forced_local_
; }
844 // Mark this symbol as forced to STB_LOCAL visibility.
846 set_is_forced_local()
847 { this->is_forced_local_
= true; }
849 // Return true if this may need a COPY relocation.
850 // References from an executable object to non-function symbols
851 // defined in a dynamic object may need a COPY relocation.
853 may_need_copy_reloc() const
855 return (parameters
->options().copyreloc()
856 && this->is_from_dynobj()
857 && !this->is_func());
860 // Return true if this symbol was predefined by the linker.
862 is_predefined() const
863 { return this->is_predefined_
; }
865 // Return true if this is a C++ vtable symbol.
867 is_cxx_vtable() const
868 { return is_prefix_of("_ZTV", this->name_
); }
871 // Instances of this class should always be created at a specific
874 { memset(this, 0, sizeof *this); }
876 // Initialize the general fields.
878 init_fields(const char* name
, const char* version
,
879 elfcpp::STT type
, elfcpp::STB binding
,
880 elfcpp::STV visibility
, unsigned char nonvis
);
882 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
883 // section index, IS_ORDINARY is whether it is a normal section
884 // index rather than a special code.
885 template<int size
, bool big_endian
>
887 init_base_object(const char* name
, const char* version
, Object
* object
,
888 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
891 // Initialize fields for an Output_data.
893 init_base_output_data(const char* name
, const char* version
, Output_data
*,
894 elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
895 unsigned char nonvis
, bool offset_is_from_end
,
898 // Initialize fields for an Output_segment.
900 init_base_output_segment(const char* name
, const char* version
,
901 Output_segment
* os
, elfcpp::STT type
,
902 elfcpp::STB binding
, elfcpp::STV visibility
,
903 unsigned char nonvis
,
904 Segment_offset_base offset_base
,
907 // Initialize fields for a constant.
909 init_base_constant(const char* name
, const char* version
, elfcpp::STT type
,
910 elfcpp::STB binding
, elfcpp::STV visibility
,
911 unsigned char nonvis
, bool is_predefined
);
913 // Initialize fields for an undefined symbol.
915 init_base_undefined(const char* name
, const char* version
, elfcpp::STT type
,
916 elfcpp::STB binding
, elfcpp::STV visibility
,
917 unsigned char nonvis
);
919 // Override existing symbol.
920 template<int size
, bool big_endian
>
922 override_base(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
923 bool is_ordinary
, Object
* object
, const char* version
);
925 // Override existing symbol with a special symbol.
927 override_base_with_special(const Symbol
* from
);
929 // Override symbol version.
931 override_version(const char* version
);
933 // Allocate a common symbol by giving it a location in the output
936 allocate_base_common(Output_data
*);
939 Symbol(const Symbol
&);
940 Symbol
& operator=(const Symbol
&);
942 // Symbol name (expected to point into a Stringpool).
944 // Symbol version (expected to point into a Stringpool). This may
946 const char* version_
;
950 // This struct is used if SOURCE_ == FROM_OBJECT.
953 // Object in which symbol is defined, or in which it was first
956 // Section number in object_ in which symbol is defined.
960 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
963 // Output_data in which symbol is defined. Before
964 // Layout::finalize the symbol's value is an offset within the
966 Output_data
* output_data
;
967 // True if the offset is from the end, false if the offset is
968 // from the beginning.
969 bool offset_is_from_end
;
972 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
975 // Output_segment in which the symbol is defined. Before
976 // Layout::finalize the symbol's value is an offset.
977 Output_segment
* output_segment
;
978 // The base to use for the offset before Layout::finalize.
979 Segment_offset_base offset_base
;
983 // The index of this symbol in the output file. If the symbol is
984 // not going into the output file, this value is -1U. This field
985 // starts as always holding zero. It is set to a non-zero value by
986 // Symbol_table::finalize.
987 unsigned int symtab_index_
;
989 // The index of this symbol in the dynamic symbol table. If the
990 // symbol is not going into the dynamic symbol table, this value is
991 // -1U. This field starts as always holding zero. It is set to a
992 // non-zero value during Layout::finalize.
993 unsigned int dynsym_index_
;
995 // The GOT section entries for this symbol. A symbol may have more
996 // than one GOT offset (e.g., when mixing modules compiled with two
997 // different TLS models), but will usually have at most one.
998 Got_offset_list got_offsets_
;
1000 // If this symbol has an entry in the PLT section, then this is the
1001 // offset from the start of the PLT section. This is -1U if there
1003 unsigned int plt_offset_
;
1005 // Symbol type (bits 0 to 3).
1006 elfcpp::STT type_
: 4;
1007 // Symbol binding (bits 4 to 7).
1008 elfcpp::STB binding_
: 4;
1009 // Symbol visibility (bits 8 to 9).
1010 elfcpp::STV visibility_
: 2;
1011 // Rest of symbol st_other field (bits 10 to 15).
1012 unsigned int nonvis_
: 6;
1013 // The type of symbol (bits 16 to 18).
1015 // True if this is the default version of the symbol (bit 19).
1017 // True if this symbol really forwards to another symbol. This is
1018 // used when we discover after the fact that two different entries
1019 // in the hash table really refer to the same symbol. This will
1020 // never be set for a symbol found in the hash table, but may be set
1021 // for a symbol found in the list of symbols attached to an Object.
1022 // It forwards to the symbol found in the forwarders_ map of
1023 // Symbol_table (bit 20).
1024 bool is_forwarder_
: 1;
1025 // True if the symbol has an alias in the weak_aliases table in
1026 // Symbol_table (bit 21).
1027 bool has_alias_
: 1;
1028 // True if this symbol needs to be in the dynamic symbol table (bit
1030 bool needs_dynsym_entry_
: 1;
1031 // True if we've seen this symbol in a regular object (bit 23).
1033 // True if we've seen this symbol in a dynamic object (bit 24).
1035 // True if this is a dynamic symbol which needs a special value in
1036 // the dynamic symbol table (bit 25).
1037 bool needs_dynsym_value_
: 1;
1038 // True if there is a warning for this symbol (bit 26).
1039 bool has_warning_
: 1;
1040 // True if we are using a COPY reloc for this symbol, so that the
1041 // real definition lives in a dynamic object (bit 27).
1042 bool is_copied_from_dynobj_
: 1;
1043 // True if this symbol was forced to local visibility by a version
1045 bool is_forced_local_
: 1;
1046 // True if the field u_.from_object.shndx is an ordinary section
1047 // index, not one of the special codes from SHN_LORESERVE to
1048 // SHN_HIRESERVE (bit 29).
1049 bool is_ordinary_shndx_
: 1;
1050 // True if we've seen this symbol in a "real" ELF object (bit 30).
1051 // If the symbol has been seen in a relocatable, non-IR, object file,
1052 // it's known to be referenced from outside the IR. A reference from
1053 // a dynamic object doesn't count as a "real" ELF, and we'll simply
1054 // mark the symbol as "visible" from outside the IR. The compiler
1055 // can use this distinction to guide its handling of COMDAT symbols.
1056 bool in_real_elf_
: 1;
1057 // True if this symbol is defined in a section which was discarded
1059 bool is_defined_in_discarded_section_
: 1;
1060 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
1061 bool undef_binding_set_
: 1;
1062 // True if this symbol was a weak undef resolved by a dynamic def
1063 // or by a special symbol (bit 33).
1064 bool undef_binding_weak_
: 1;
1065 // True if this symbol is a predefined linker symbol (bit 34).
1066 bool is_predefined_
: 1;
1069 // The parts of a symbol which are size specific. Using a template
1070 // derived class like this helps us use less space on a 32-bit system.
1073 class Sized_symbol
: public Symbol
1076 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value_type
;
1077 typedef typename
elfcpp::Elf_types
<size
>::Elf_WXword Size_type
;
1082 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
1083 // section index, IS_ORDINARY is whether it is a normal section
1084 // index rather than a special code.
1085 template<bool big_endian
>
1087 init_object(const char* name
, const char* version
, Object
* object
,
1088 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1091 // Initialize fields for an Output_data.
1093 init_output_data(const char* name
, const char* version
, Output_data
*,
1094 Value_type value
, Size_type symsize
, elfcpp::STT
,
1095 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1096 bool offset_is_from_end
, bool is_predefined
);
1098 // Initialize fields for an Output_segment.
1100 init_output_segment(const char* name
, const char* version
, Output_segment
*,
1101 Value_type value
, Size_type symsize
, elfcpp::STT
,
1102 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1103 Segment_offset_base offset_base
, bool is_predefined
);
1105 // Initialize fields for a constant.
1107 init_constant(const char* name
, const char* version
, Value_type value
,
1108 Size_type symsize
, elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
1109 unsigned char nonvis
, bool is_predefined
);
1111 // Initialize fields for an undefined symbol.
1113 init_undefined(const char* name
, const char* version
, elfcpp::STT
,
1114 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
);
1116 // Override existing symbol.
1117 template<bool big_endian
>
1119 override(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1120 bool is_ordinary
, Object
* object
, const char* version
);
1122 // Override existing symbol with a special symbol.
1124 override_with_special(const Sized_symbol
<size
>*);
1126 // Return the symbol's value.
1129 { return this->value_
; }
1131 // Return the symbol's size (we can't call this 'size' because that
1132 // is a template parameter).
1135 { return this->symsize_
; }
1137 // Set the symbol size. This is used when resolving common symbols.
1139 set_symsize(Size_type symsize
)
1140 { this->symsize_
= symsize
; }
1142 // Set the symbol value. This is called when we store the final
1143 // values of the symbols into the symbol table.
1145 set_value(Value_type value
)
1146 { this->value_
= value
; }
1148 // Allocate a common symbol by giving it a location in the output
1151 allocate_common(Output_data
*, Value_type value
);
1154 Sized_symbol(const Sized_symbol
&);
1155 Sized_symbol
& operator=(const Sized_symbol
&);
1157 // Symbol value. Before Layout::finalize this is the offset in the
1158 // input section. This is set to the final value during
1159 // Layout::finalize.
1165 // A struct describing a symbol defined by the linker, where the value
1166 // of the symbol is defined based on an output section. This is used
1167 // for symbols defined by the linker, like "_init_array_start".
1169 struct Define_symbol_in_section
1173 // The name of the output section with which this symbol should be
1174 // associated. If there is no output section with that name, the
1175 // symbol will be defined as zero.
1176 const char* output_section
;
1177 // The offset of the symbol within the output section. This is an
1178 // offset from the start of the output section, unless start_at_end
1179 // is true, in which case this is an offset from the end of the
1182 // The size of the symbol.
1186 // The symbol binding.
1187 elfcpp::STB binding
;
1188 // The symbol visibility.
1189 elfcpp::STV visibility
;
1190 // The rest of the st_other field.
1191 unsigned char nonvis
;
1192 // If true, the value field is an offset from the end of the output
1194 bool offset_is_from_end
;
1195 // If true, this symbol is defined only if we see a reference to it.
1199 // A struct describing a symbol defined by the linker, where the value
1200 // of the symbol is defined based on a segment. This is used for
1201 // symbols defined by the linker, like "_end". We describe the
1202 // segment with which the symbol should be associated by its
1203 // characteristics. If no segment meets these characteristics, the
1204 // symbol will be defined as zero. If there is more than one segment
1205 // which meets these characteristics, we will use the first one.
1207 struct Define_symbol_in_segment
1211 // The segment type where the symbol should be defined, typically
1213 elfcpp::PT segment_type
;
1214 // Bitmask of segment flags which must be set.
1215 elfcpp::PF segment_flags_set
;
1216 // Bitmask of segment flags which must be clear.
1217 elfcpp::PF segment_flags_clear
;
1218 // The offset of the symbol within the segment. The offset is
1219 // calculated from the position set by offset_base.
1221 // The size of the symbol.
1225 // The symbol binding.
1226 elfcpp::STB binding
;
1227 // The symbol visibility.
1228 elfcpp::STV visibility
;
1229 // The rest of the st_other field.
1230 unsigned char nonvis
;
1231 // The base from which we compute the offset.
1232 Symbol::Segment_offset_base offset_base
;
1233 // If true, this symbol is defined only if we see a reference to it.
1237 // Specify an object/section/offset location. Used by ODR code.
1239 struct Symbol_location
1241 // Object where the symbol is defined.
1243 // Section-in-object where the symbol is defined.
1245 // For relocatable objects, offset-in-section where the symbol is defined.
1246 // For dynamic objects, address where the symbol is defined.
1248 bool operator==(const Symbol_location
& that
) const
1250 return (this->object
== that
.object
1251 && this->shndx
== that
.shndx
1252 && this->offset
== that
.offset
);
1256 // This class manages warnings. Warnings are a GNU extension. When
1257 // we see a section named .gnu.warning.SYM in an object file, and if
1258 // we wind using the definition of SYM from that object file, then we
1259 // will issue a warning for any relocation against SYM from a
1260 // different object file. The text of the warning is the contents of
1261 // the section. This is not precisely the definition used by the old
1262 // GNU linker; the old GNU linker treated an occurrence of
1263 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1264 // would trigger a warning on any reference. However, it was
1265 // inconsistent in that a warning in a dynamic object only triggered
1266 // if there was no definition in a regular object. This linker is
1267 // different in that we only issue a warning if we use the symbol
1268 // definition from the same object file as the warning section.
1277 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1280 add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
1281 const std::string
& warning
);
1283 // For each symbol for which we should give a warning, make a note
1286 note_warnings(Symbol_table
* symtab
);
1288 // Issue a warning for a reference to SYM at RELINFO's location.
1289 template<int size
, bool big_endian
>
1291 issue_warning(const Symbol
* sym
, const Relocate_info
<size
, big_endian
>*,
1292 size_t relnum
, off_t reloffset
) const;
1295 Warnings(const Warnings
&);
1296 Warnings
& operator=(const Warnings
&);
1298 // What we need to know to get the warning text.
1299 struct Warning_location
1301 // The object the warning is in.
1303 // The warning text.
1307 : object(NULL
), text()
1311 set(Object
* o
, const std::string
& t
)
1318 // A mapping from warning symbol names (canonicalized in
1319 // Symbol_table's namepool_ field) to warning information.
1320 typedef Unordered_map
<const char*, Warning_location
> Warning_table
;
1322 Warning_table warnings_
;
1325 // The main linker symbol table.
1330 // The different places where a symbol definition can come from.
1333 // Defined in an object file--the normal case.
1335 // Defined for a COPY reloc.
1337 // Defined on the command line using --defsym.
1339 // Defined (so to speak) on the command line using -u.
1341 // Defined in a linker script.
1343 // Predefined by the linker.
1345 // Defined by the linker during an incremental base link, but not
1346 // a predefined symbol (e.g., common, defined in script).
1350 // The order in which we sort common symbols.
1351 enum Sort_commons_order
1353 SORT_COMMONS_BY_SIZE_DESCENDING
,
1354 SORT_COMMONS_BY_ALIGNMENT_DESCENDING
,
1355 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1358 // COUNT is an estimate of how many symbols will be inserted in the
1359 // symbol table. It's ok to put 0 if you don't know; a correct
1360 // guess will just save some CPU by reducing hashtable resizes.
1361 Symbol_table(unsigned int count
, const Version_script_info
& version_script
);
1367 { this->icf_
= icf
;}
1371 { return this->icf_
; }
1373 // Returns true if ICF determined that this is a duplicate section.
1375 is_section_folded(Object
* obj
, unsigned int shndx
) const;
1378 set_gc(Garbage_collection
* gc
)
1383 { return this->gc_
; }
1385 // During garbage collection, this keeps undefined symbols.
1387 gc_mark_undef_symbols(Layout
*);
1389 // This tells garbage collection that this symbol is referenced.
1391 gc_mark_symbol(Symbol
* sym
);
1393 // During garbage collection, this keeps sections that correspond to
1394 // symbols seen in dynamic objects.
1396 gc_mark_dyn_syms(Symbol
* sym
);
1398 // Add COUNT external symbols from the relocatable object RELOBJ to
1399 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1400 // offset in the symbol table of the first symbol, SYM_NAMES is
1401 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1402 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1403 // *DEFINED to the number of defined symbols.
1404 template<int size
, bool big_endian
>
1406 add_from_relobj(Sized_relobj_file
<size
, big_endian
>* relobj
,
1407 const unsigned char* syms
, size_t count
,
1408 size_t symndx_offset
, const char* sym_names
,
1409 size_t sym_name_size
,
1410 typename Sized_relobj_file
<size
, big_endian
>::Symbols
*,
1413 // Add one external symbol from the plugin object OBJ to the symbol table.
1414 // Returns a pointer to the resolved symbol in the symbol table.
1415 template<int size
, bool big_endian
>
1417 add_from_pluginobj(Sized_pluginobj
<size
, big_endian
>* obj
,
1418 const char* name
, const char* ver
,
1419 elfcpp::Sym
<size
, big_endian
>* sym
);
1421 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1422 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1423 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1424 // symbol version data.
1425 template<int size
, bool big_endian
>
1427 add_from_dynobj(Sized_dynobj
<size
, big_endian
>* dynobj
,
1428 const unsigned char* syms
, size_t count
,
1429 const char* sym_names
, size_t sym_name_size
,
1430 const unsigned char* versym
, size_t versym_size
,
1431 const std::vector
<const char*>*,
1432 typename Sized_relobj_file
<size
, big_endian
>::Symbols
*,
1435 // Add one external symbol from the incremental object OBJ to the symbol
1436 // table. Returns a pointer to the resolved symbol in the symbol table.
1437 template<int size
, bool big_endian
>
1439 add_from_incrobj(Object
* obj
, const char* name
,
1440 const char* ver
, elfcpp::Sym
<size
, big_endian
>* sym
);
1442 // Define a special symbol based on an Output_data. It is a
1443 // multiple definition error if this symbol is already defined.
1445 define_in_output_data(const char* name
, const char* version
, Defined
,
1446 Output_data
*, uint64_t value
, uint64_t symsize
,
1447 elfcpp::STT type
, elfcpp::STB binding
,
1448 elfcpp::STV visibility
, unsigned char nonvis
,
1449 bool offset_is_from_end
, bool only_if_ref
);
1451 // Define a special symbol based on an Output_segment. It is a
1452 // multiple definition error if this symbol is already defined.
1454 define_in_output_segment(const char* name
, const char* version
, Defined
,
1455 Output_segment
*, uint64_t value
, uint64_t symsize
,
1456 elfcpp::STT type
, elfcpp::STB binding
,
1457 elfcpp::STV visibility
, unsigned char nonvis
,
1458 Symbol::Segment_offset_base
, bool only_if_ref
);
1460 // Define a special symbol with a constant value. It is a multiple
1461 // definition error if this symbol is already defined.
1463 define_as_constant(const char* name
, const char* version
, Defined
,
1464 uint64_t value
, uint64_t symsize
, elfcpp::STT type
,
1465 elfcpp::STB binding
, elfcpp::STV visibility
,
1466 unsigned char nonvis
, bool only_if_ref
,
1467 bool force_override
);
1469 // Define a set of symbols in output sections. If ONLY_IF_REF is
1470 // true, only define them if they are referenced.
1472 define_symbols(const Layout
*, int count
, const Define_symbol_in_section
*,
1475 // Define a set of symbols in output segments. If ONLY_IF_REF is
1476 // true, only defined them if they are referenced.
1478 define_symbols(const Layout
*, int count
, const Define_symbol_in_segment
*,
1481 // Define SYM using a COPY reloc. POSD is the Output_data where the
1482 // symbol should be defined--typically a .dyn.bss section. VALUE is
1483 // the offset within POSD.
1486 define_with_copy_reloc(Sized_symbol
<size
>* sym
, Output_data
* posd
,
1487 typename
elfcpp::Elf_types
<size
>::Elf_Addr
);
1489 // Look up a symbol.
1491 lookup(const char*, const char* version
= NULL
) const;
1493 // Return the real symbol associated with the forwarder symbol FROM.
1495 resolve_forwards(const Symbol
* from
) const;
1497 // Return the sized version of a symbol in this table.
1500 get_sized_symbol(Symbol
*) const;
1503 const Sized_symbol
<size
>*
1504 get_sized_symbol(const Symbol
*) const;
1506 // Return the count of undefined symbols seen.
1508 saw_undefined() const
1509 { return this->saw_undefined_
; }
1511 // Allocate the common symbols
1513 allocate_commons(Layout
*, Mapfile
*);
1515 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1518 add_warning(const char* name
, Object
* obj
, const std::string
& warning
)
1519 { this->warnings_
.add_warning(this, name
, obj
, warning
); }
1521 // Canonicalize a symbol name for use in the hash table.
1523 canonicalize_name(const char* name
)
1524 { return this->namepool_
.add(name
, true, NULL
); }
1526 // Possibly issue a warning for a reference to SYM at LOCATION which
1528 template<int size
, bool big_endian
>
1530 issue_warning(const Symbol
* sym
,
1531 const Relocate_info
<size
, big_endian
>* relinfo
,
1532 size_t relnum
, off_t reloffset
) const
1533 { this->warnings_
.issue_warning(sym
, relinfo
, relnum
, reloffset
); }
1535 // Check candidate_odr_violations_ to find symbols with the same name
1536 // but apparently different definitions (different source-file/line-no).
1538 detect_odr_violations(const Task
*, const char* output_file_name
) const;
1540 // Add any undefined symbols named on the command line to the symbol
1543 add_undefined_symbols_from_command_line(Layout
*);
1545 // SYM is defined using a COPY reloc. Return the dynamic object
1546 // where the original definition was found.
1548 get_copy_source(const Symbol
* sym
) const;
1550 // Set the dynamic symbol indexes. INDEX is the index of the first
1551 // global dynamic symbol. Pointers to the symbols are stored into
1552 // the vector. The names are stored into the Stringpool. This
1553 // returns an updated dynamic symbol index.
1555 set_dynsym_indexes(unsigned int index
, std::vector
<Symbol
*>*,
1556 Stringpool
*, Versions
*);
1558 // Finalize the symbol table after we have set the final addresses
1559 // of all the input sections. This sets the final symbol indexes,
1560 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1561 // index of the first global symbol. OFF is the file offset of the
1562 // global symbol table, DYNOFF is the offset of the globals in the
1563 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1564 // global dynamic symbol, and DYNCOUNT is the number of global
1565 // dynamic symbols. This records the parameters, and returns the
1566 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1569 finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
, size_t dyncount
,
1570 Stringpool
* pool
, unsigned int* plocal_symcount
);
1572 // Set the final file offset of the symbol table.
1574 set_file_offset(off_t off
)
1575 { this->offset_
= off
; }
1577 // Status code of Symbol_table::compute_final_value.
1578 enum Compute_final_value_status
1582 // Unsupported symbol section.
1583 CFVS_UNSUPPORTED_SYMBOL_SECTION
,
1584 // No output section.
1585 CFVS_NO_OUTPUT_SECTION
1588 // Compute the final value of SYM and store status in location PSTATUS.
1589 // During relaxation, this may be called multiple times for a symbol to
1590 // compute its would-be final value in each relaxation pass.
1593 typename Sized_symbol
<size
>::Value_type
1594 compute_final_value(const Sized_symbol
<size
>* sym
,
1595 Compute_final_value_status
* pstatus
) const;
1597 // Return the index of the first global symbol.
1599 first_global_index() const
1600 { return this->first_global_index_
; }
1602 // Return the total number of symbols in the symbol table.
1604 output_count() const
1605 { return this->output_count_
; }
1607 // Write out the global symbols.
1609 write_globals(const Stringpool
*, const Stringpool
*,
1610 Output_symtab_xindex
*, Output_symtab_xindex
*,
1611 Output_file
*) const;
1613 // Write out a section symbol. Return the updated offset.
1615 write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1616 Output_file
*, off_t
) const;
1618 // Loop over all symbols, applying the function F to each.
1619 template<int size
, typename F
>
1621 for_all_symbols(F f
) const
1623 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1624 p
!= this->table_
.end();
1627 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1632 // Dump statistical information to stderr.
1634 print_stats() const;
1636 // Return the version script information.
1637 const Version_script_info
&
1638 version_script() const
1639 { return version_script_
; }
1642 Symbol_table(const Symbol_table
&);
1643 Symbol_table
& operator=(const Symbol_table
&);
1645 // The type of the list of common symbols.
1646 typedef std::vector
<Symbol
*> Commons_type
;
1648 // The type of the symbol hash table.
1650 typedef std::pair
<Stringpool::Key
, Stringpool::Key
> Symbol_table_key
;
1652 // The hash function. The key values are Stringpool keys.
1653 struct Symbol_table_hash
1656 operator()(const Symbol_table_key
& key
) const
1658 return key
.first
^ key
.second
;
1662 struct Symbol_table_eq
1665 operator()(const Symbol_table_key
&, const Symbol_table_key
&) const;
1668 typedef Unordered_map
<Symbol_table_key
, Symbol
*, Symbol_table_hash
,
1669 Symbol_table_eq
> Symbol_table_type
;
1671 // A map from symbol name (as a pointer into the namepool) to all
1672 // the locations the symbols is (weakly) defined (and certain other
1673 // conditions are met). This map will be used later to detect
1674 // possible One Definition Rule (ODR) violations.
1675 struct Symbol_location_hash
1677 size_t operator()(const Symbol_location
& loc
) const
1678 { return reinterpret_cast<uintptr_t>(loc
.object
) ^ loc
.offset
^ loc
.shndx
; }
1681 typedef Unordered_map
<const char*,
1682 Unordered_set
<Symbol_location
, Symbol_location_hash
> >
1685 // Make FROM a forwarder symbol to TO.
1687 make_forwarder(Symbol
* from
, Symbol
* to
);
1690 template<int size
, bool big_endian
>
1692 add_from_object(Object
*, const char* name
, Stringpool::Key name_key
,
1693 const char* version
, Stringpool::Key version_key
,
1694 bool def
, const elfcpp::Sym
<size
, big_endian
>& sym
,
1695 unsigned int st_shndx
, bool is_ordinary
,
1696 unsigned int orig_st_shndx
);
1698 // Define a default symbol.
1699 template<int size
, bool big_endian
>
1701 define_default_version(Sized_symbol
<size
>*, bool,
1702 Symbol_table_type::iterator
);
1705 template<int size
, bool big_endian
>
1707 resolve(Sized_symbol
<size
>* to
,
1708 const elfcpp::Sym
<size
, big_endian
>& sym
,
1709 unsigned int st_shndx
, bool is_ordinary
,
1710 unsigned int orig_st_shndx
,
1711 Object
*, const char* version
);
1713 template<int size
, bool big_endian
>
1715 resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
);
1717 // Record that a symbol is forced to be local by a version script or
1720 force_local(Symbol
*);
1722 // Adjust NAME and *NAME_KEY for wrapping.
1724 wrap_symbol(const char* name
, Stringpool::Key
* name_key
);
1726 // Whether we should override a symbol, based on flags in
1729 should_override(const Symbol
*, unsigned int, elfcpp::STT
, Defined
,
1730 Object
*, bool*, bool*);
1732 // Report a problem in symbol resolution.
1734 report_resolve_problem(bool is_error
, const char* msg
, const Symbol
* to
,
1735 Defined
, Object
* object
);
1737 // Override a symbol.
1738 template<int size
, bool big_endian
>
1740 override(Sized_symbol
<size
>* tosym
,
1741 const elfcpp::Sym
<size
, big_endian
>& fromsym
,
1742 unsigned int st_shndx
, bool is_ordinary
,
1743 Object
* object
, const char* version
);
1745 // Whether we should override a symbol with a special symbol which
1746 // is automatically defined by the linker.
1748 should_override_with_special(const Symbol
*, elfcpp::STT
, Defined
);
1750 // Override a symbol with a special symbol.
1753 override_with_special(Sized_symbol
<size
>* tosym
,
1754 const Sized_symbol
<size
>* fromsym
);
1756 // Record all weak alias sets for a dynamic object.
1759 record_weak_aliases(std::vector
<Sized_symbol
<size
>*>*);
1761 // Define a special symbol.
1762 template<int size
, bool big_endian
>
1764 define_special_symbol(const char** pname
, const char** pversion
,
1765 bool only_if_ref
, Sized_symbol
<size
>** poldsym
,
1766 bool* resolve_oldsym
);
1768 // Define a symbol in an Output_data, sized version.
1771 do_define_in_output_data(const char* name
, const char* version
, Defined
,
1773 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1774 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1775 elfcpp::STT type
, elfcpp::STB binding
,
1776 elfcpp::STV visibility
, unsigned char nonvis
,
1777 bool offset_is_from_end
, bool only_if_ref
);
1779 // Define a symbol in an Output_segment, sized version.
1782 do_define_in_output_segment(
1783 const char* name
, const char* version
, Defined
, Output_segment
* os
,
1784 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1785 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1786 elfcpp::STT type
, elfcpp::STB binding
,
1787 elfcpp::STV visibility
, unsigned char nonvis
,
1788 Symbol::Segment_offset_base offset_base
, bool only_if_ref
);
1790 // Define a symbol as a constant, sized version.
1793 do_define_as_constant(
1794 const char* name
, const char* version
, Defined
,
1795 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1796 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1797 elfcpp::STT type
, elfcpp::STB binding
,
1798 elfcpp::STV visibility
, unsigned char nonvis
,
1799 bool only_if_ref
, bool force_override
);
1801 // Add any undefined symbols named on the command line to the symbol
1802 // table, sized version.
1805 do_add_undefined_symbols_from_command_line(Layout
*);
1807 // Add one undefined symbol.
1810 add_undefined_symbol_from_command_line(const char* name
);
1812 // Types of common symbols.
1814 enum Commons_section_type
1822 // Allocate the common symbols, sized version.
1825 do_allocate_commons(Layout
*, Mapfile
*, Sort_commons_order
);
1827 // Allocate the common symbols from one list.
1830 do_allocate_commons_list(Layout
*, Commons_section_type
, Commons_type
*,
1831 Mapfile
*, Sort_commons_order
);
1833 // Returns all of the lines attached to LOC, not just the one the
1834 // instruction actually came from. This helps the ODR checker avoid
1836 static std::vector
<std::string
>
1837 linenos_from_loc(const Task
* task
, const Symbol_location
& loc
);
1839 // Implement detect_odr_violations.
1840 template<int size
, bool big_endian
>
1842 sized_detect_odr_violations() const;
1844 // Finalize symbols specialized for size.
1847 sized_finalize(off_t
, Stringpool
*, unsigned int*);
1849 // Finalize a symbol. Return whether it should be added to the
1853 sized_finalize_symbol(Symbol
*);
1855 // Add a symbol the final symtab by setting its index.
1858 add_to_final_symtab(Symbol
*, Stringpool
*, unsigned int* pindex
, off_t
* poff
);
1860 // Write globals specialized for size and endianness.
1861 template<int size
, bool big_endian
>
1863 sized_write_globals(const Stringpool
*, const Stringpool
*,
1864 Output_symtab_xindex
*, Output_symtab_xindex
*,
1865 Output_file
*) const;
1867 // Write out a symbol to P.
1868 template<int size
, bool big_endian
>
1870 sized_write_symbol(Sized_symbol
<size
>*,
1871 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1872 unsigned int shndx
, elfcpp::STB
,
1873 const Stringpool
*, unsigned char* p
) const;
1875 // Possibly warn about an undefined symbol from a dynamic object.
1877 warn_about_undefined_dynobj_symbol(Symbol
*) const;
1879 // Write out a section symbol, specialized for size and endianness.
1880 template<int size
, bool big_endian
>
1882 sized_write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1883 Output_file
*, off_t
) const;
1885 // The type of the list of symbols which have been forced local.
1886 typedef std::vector
<Symbol
*> Forced_locals
;
1888 // A map from symbols with COPY relocs to the dynamic objects where
1889 // they are defined.
1890 typedef Unordered_map
<const Symbol
*, Dynobj
*> Copied_symbol_dynobjs
;
1892 // We increment this every time we see a new undefined symbol, for
1893 // use in archive groups.
1894 size_t saw_undefined_
;
1895 // The index of the first global symbol in the output file.
1896 unsigned int first_global_index_
;
1897 // The file offset within the output symtab section where we should
1900 // The number of global symbols we want to write out.
1901 unsigned int output_count_
;
1902 // The file offset of the global dynamic symbols, or 0 if none.
1903 off_t dynamic_offset_
;
1904 // The index of the first global dynamic symbol.
1905 unsigned int first_dynamic_global_index_
;
1906 // The number of global dynamic symbols, or 0 if none.
1907 unsigned int dynamic_count_
;
1908 // The symbol hash table.
1909 Symbol_table_type table_
;
1910 // A pool of symbol names. This is used for all global symbols.
1911 // Entries in the hash table point into this pool.
1912 Stringpool namepool_
;
1913 // Forwarding symbols.
1914 Unordered_map
<const Symbol
*, Symbol
*> forwarders_
;
1915 // Weak aliases. A symbol in this list points to the next alias.
1916 // The aliases point to each other in a circular list.
1917 Unordered_map
<Symbol
*, Symbol
*> weak_aliases_
;
1918 // We don't expect there to be very many common symbols, so we keep
1919 // a list of them. When we find a common symbol we add it to this
1920 // list. It is possible that by the time we process the list the
1921 // symbol is no longer a common symbol. It may also have become a
1923 Commons_type commons_
;
1924 // This is like the commons_ field, except that it holds TLS common
1926 Commons_type tls_commons_
;
1927 // This is for small common symbols.
1928 Commons_type small_commons_
;
1929 // This is for large common symbols.
1930 Commons_type large_commons_
;
1931 // A list of symbols which have been forced to be local. We don't
1932 // expect there to be very many of them, so we keep a list of them
1933 // rather than walking the whole table to find them.
1934 Forced_locals forced_locals_
;
1935 // Manage symbol warnings.
1937 // Manage potential One Definition Rule (ODR) violations.
1938 Odr_map candidate_odr_violations_
;
1940 // When we emit a COPY reloc for a symbol, we define it in an
1941 // Output_data. When it's time to emit version information for it,
1942 // we need to know the dynamic object in which we found the original
1943 // definition. This maps symbols with COPY relocs to the dynamic
1944 // object where they were defined.
1945 Copied_symbol_dynobjs copied_symbol_dynobjs_
;
1946 // Information parsed from the version script, if any.
1947 const Version_script_info
& version_script_
;
1948 Garbage_collection
* gc_
;
1952 // We inline get_sized_symbol for efficiency.
1956 Symbol_table::get_sized_symbol(Symbol
* sym
) const
1958 gold_assert(size
== parameters
->target().get_size());
1959 return static_cast<Sized_symbol
<size
>*>(sym
);
1963 const Sized_symbol
<size
>*
1964 Symbol_table::get_sized_symbol(const Symbol
* sym
) const
1966 gold_assert(size
== parameters
->target().get_size());
1967 return static_cast<const Sized_symbol
<size
>*>(sym
);
1970 } // End namespace gold.
1972 #endif // !defined(GOLD_SYMTAB_H)