1 // symtab.h -- the gold symbol table -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 // Return true for function symbol.
222 return (this->type_
== elfcpp::STT_FUNC
223 || this->type_
== elfcpp::STT_GNU_IFUNC
);
226 // Return the symbol visibility.
229 { return this->visibility_
; }
231 // Set the visibility.
233 set_visibility(elfcpp::STV visibility
)
234 { this->visibility_
= visibility
; }
236 // Override symbol visibility.
238 override_visibility(elfcpp::STV
);
240 // Set whether the symbol was originally a weak undef or a regular undef
241 // when resolved by a dynamic def.
243 set_undef_binding(elfcpp::STB bind
)
245 if (!this->undef_binding_set_
|| this->undef_binding_weak_
)
247 this->undef_binding_weak_
= bind
== elfcpp::STB_WEAK
;
248 this->undef_binding_set_
= true;
252 // Return TRUE if a weak undef was resolved by a dynamic def.
254 is_undef_binding_weak() const
255 { return this->undef_binding_weak_
; }
257 // Return the non-visibility part of the st_other field.
260 { return this->nonvis_
; }
262 // Return whether this symbol is a forwarder. This will never be
263 // true of a symbol found in the hash table, but may be true of
264 // symbol pointers attached to object files.
267 { return this->is_forwarder_
; }
269 // Mark this symbol as a forwarder.
272 { this->is_forwarder_
= true; }
274 // Return whether this symbol has an alias in the weak aliases table
278 { return this->has_alias_
; }
280 // Mark this symbol as having an alias.
283 { this->has_alias_
= true; }
285 // Return whether this symbol needs an entry in the dynamic symbol
288 needs_dynsym_entry() const
290 return (this->needs_dynsym_entry_
293 && this->is_externally_visible()));
296 // Mark this symbol as needing an entry in the dynamic symbol table.
298 set_needs_dynsym_entry()
299 { this->needs_dynsym_entry_
= true; }
301 // Return whether this symbol should be added to the dynamic symbol
304 should_add_dynsym_entry(Symbol_table
*) const;
306 // Return whether this symbol has been seen in a regular object.
309 { return this->in_reg_
; }
311 // Mark this symbol as having been seen in a regular object.
314 { this->in_reg_
= true; }
316 // Return whether this symbol has been seen in a dynamic object.
319 { return this->in_dyn_
; }
321 // Mark this symbol as having been seen in a dynamic object.
324 { this->in_dyn_
= true; }
326 // Return whether this symbol has been seen in a real ELF object.
327 // (IN_REG will return TRUE if the symbol has been seen in either
328 // a real ELF object or an object claimed by a plugin.)
331 { return this->in_real_elf_
; }
333 // Mark this symbol as having been seen in a real ELF object.
336 { this->in_real_elf_
= true; }
338 // Return whether this symbol was defined in a section that was
339 // discarded from the link. This is used to control some error
342 is_defined_in_discarded_section() const
343 { return this->is_defined_in_discarded_section_
; }
345 // Mark this symbol as having been defined in a discarded section.
347 set_is_defined_in_discarded_section()
348 { this->is_defined_in_discarded_section_
= true; }
350 // Return the index of this symbol in the output file symbol table.
351 // A value of -1U means that this symbol is not going into the
352 // output file. This starts out as zero, and is set to a non-zero
353 // value by Symbol_table::finalize. It is an error to ask for the
354 // symbol table index before it has been set.
358 gold_assert(this->symtab_index_
!= 0);
359 return this->symtab_index_
;
362 // Set the index of the symbol in the output file symbol table.
364 set_symtab_index(unsigned int index
)
366 gold_assert(index
!= 0);
367 this->symtab_index_
= index
;
370 // Return whether this symbol already has an index in the output
371 // file symbol table.
373 has_symtab_index() const
374 { return this->symtab_index_
!= 0; }
376 // Return the index of this symbol in the dynamic symbol table. A
377 // value of -1U means that this symbol is not going into the dynamic
378 // symbol table. This starts out as zero, and is set to a non-zero
379 // during Layout::finalize. It is an error to ask for the dynamic
380 // symbol table index before it has been set.
384 gold_assert(this->dynsym_index_
!= 0);
385 return this->dynsym_index_
;
388 // Set the index of the symbol in the dynamic symbol table.
390 set_dynsym_index(unsigned int index
)
392 gold_assert(index
!= 0);
393 this->dynsym_index_
= index
;
396 // Return whether this symbol already has an index in the dynamic
399 has_dynsym_index() const
400 { return this->dynsym_index_
!= 0; }
402 // Return whether this symbol has an entry in the GOT section.
403 // For a TLS symbol, this GOT entry will hold its tp-relative offset.
405 has_got_offset(unsigned int got_type
) const
406 { return this->got_offsets_
.get_offset(got_type
) != -1U; }
408 // Return the offset into the GOT section of this symbol.
410 got_offset(unsigned int got_type
) const
412 unsigned int got_offset
= this->got_offsets_
.get_offset(got_type
);
413 gold_assert(got_offset
!= -1U);
417 // Set the GOT offset of this symbol.
419 set_got_offset(unsigned int got_type
, unsigned int got_offset
)
420 { this->got_offsets_
.set_offset(got_type
, got_offset
); }
422 // Return the GOT offset list.
423 const Got_offset_list
*
424 got_offset_list() const
425 { return this->got_offsets_
.get_list(); }
427 // Return whether this symbol has an entry in the PLT section.
429 has_plt_offset() const
430 { return this->plt_offset_
!= -1U; }
432 // Return the offset into the PLT section of this symbol.
436 gold_assert(this->has_plt_offset());
437 return this->plt_offset_
;
440 // Set the PLT offset of this symbol.
442 set_plt_offset(unsigned int plt_offset
)
444 gold_assert(plt_offset
!= -1U);
445 this->plt_offset_
= plt_offset
;
448 // Return whether this dynamic symbol needs a special value in the
449 // dynamic symbol table.
451 needs_dynsym_value() const
452 { return this->needs_dynsym_value_
; }
454 // Set that this dynamic symbol needs a special value in the dynamic
457 set_needs_dynsym_value()
459 gold_assert(this->object()->is_dynamic());
460 this->needs_dynsym_value_
= true;
463 // Return true if the final value of this symbol is known at link
466 final_value_is_known() const;
468 // Return true if SHNDX represents a common symbol. This depends on
471 is_common_shndx(unsigned int shndx
);
473 // Return whether this is a defined symbol (not undefined or
479 if (this->source_
!= FROM_OBJECT
)
480 return this->source_
!= IS_UNDEFINED
;
481 unsigned int shndx
= this->shndx(&is_ordinary
);
483 ? shndx
!= elfcpp::SHN_UNDEF
484 : !Symbol::is_common_shndx(shndx
));
487 // Return true if this symbol is from a dynamic object.
489 is_from_dynobj() const
491 return this->source_
== FROM_OBJECT
&& this->object()->is_dynamic();
494 // Return whether this is a placeholder symbol from a plugin object.
496 is_placeholder() const
498 return this->source_
== FROM_OBJECT
&& this->object()->pluginobj() != NULL
;
501 // Return whether this is an undefined symbol.
506 return ((this->source_
== FROM_OBJECT
507 && this->shndx(&is_ordinary
) == elfcpp::SHN_UNDEF
509 || this->source_
== IS_UNDEFINED
);
512 // Return whether this is a weak undefined symbol.
514 is_weak_undefined() const
515 { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK
; }
517 // Return whether this is an absolute symbol.
522 return ((this->source_
== FROM_OBJECT
523 && this->shndx(&is_ordinary
) == elfcpp::SHN_ABS
525 || this->source_
== IS_CONSTANT
);
528 // Return whether this is a common symbol.
532 if (this->source_
!= FROM_OBJECT
)
534 if (this->type_
== elfcpp::STT_COMMON
)
537 unsigned int shndx
= this->shndx(&is_ordinary
);
538 return !is_ordinary
&& Symbol::is_common_shndx(shndx
);
541 // Return whether this symbol can be seen outside this object.
543 is_externally_visible() const
545 return ((this->visibility_
== elfcpp::STV_DEFAULT
546 || this->visibility_
== elfcpp::STV_PROTECTED
)
547 && !this->is_forced_local_
);
550 // Return true if this symbol can be preempted by a definition in
551 // another link unit.
553 is_preemptible() const
555 // It doesn't make sense to ask whether a symbol defined in
556 // another object is preemptible.
557 gold_assert(!this->is_from_dynobj());
559 // It doesn't make sense to ask whether an undefined symbol
561 gold_assert(!this->is_undefined());
563 // If a symbol does not have default visibility, it can not be
564 // seen outside this link unit and therefore is not preemptible.
565 if (this->visibility_
!= elfcpp::STV_DEFAULT
)
568 // If this symbol has been forced to be a local symbol by a
569 // version script, then it is not visible outside this link unit
570 // and is not preemptible.
571 if (this->is_forced_local_
)
574 // If we are not producing a shared library, then nothing is
576 if (!parameters
->options().shared())
579 // If the user used -Bsymbolic, then nothing is preemptible.
580 if (parameters
->options().Bsymbolic())
583 // If the user used -Bsymbolic-functions, then functions are not
584 // preemptible. We explicitly check for not being STT_OBJECT,
585 // rather than for being STT_FUNC, because that is what the GNU
587 if (this->type() != elfcpp::STT_OBJECT
588 && parameters
->options().Bsymbolic_functions())
591 // Otherwise the symbol is preemptible.
595 // Return true if this symbol is a function that needs a PLT entry.
597 needs_plt_entry() const
599 // An undefined symbol from an executable does not need a PLT entry.
600 if (this->is_undefined() && !parameters
->options().shared())
603 // An STT_GNU_IFUNC symbol always needs a PLT entry, even when
604 // doing a static link.
605 if (this->type() == elfcpp::STT_GNU_IFUNC
)
608 // We only need a PLT entry for a function.
609 if (!this->is_func())
612 // If we're doing a static link or a -pie link, we don't create
614 if (parameters
->doing_static_link()
615 || parameters
->options().pie())
618 // We need a PLT entry if the function is defined in a dynamic
619 // object, or is undefined when building a shared object, or if it
620 // is subject to pre-emption.
621 return (this->is_from_dynobj()
622 || this->is_undefined()
623 || this->is_preemptible());
626 // When determining whether a reference to a symbol needs a dynamic
627 // relocation, we need to know several things about the reference.
628 // These flags may be or'ed together. 0 means that the symbol
629 // isn't referenced at all.
632 // A reference to the symbol's absolute address. This includes
633 // references that cause an absolute address to be stored in the GOT.
635 // A reference that calculates the offset of the symbol from some
636 // anchor point, such as the PC or GOT.
638 // A TLS-related reference.
640 // A reference that can always be treated as a function call.
642 // When set, says that dynamic relocations are needed even if a
643 // symbol has a plt entry.
647 // Given a direct absolute or pc-relative static relocation against
648 // the global symbol, this function returns whether a dynamic relocation
652 needs_dynamic_reloc(int flags
) const
654 // No dynamic relocations in a static link!
655 if (parameters
->doing_static_link())
658 // A reference to an undefined symbol from an executable should be
659 // statically resolved to 0, and does not need a dynamic relocation.
660 // This matches gnu ld behavior.
661 if (this->is_undefined() && !parameters
->options().shared())
664 // A reference to an absolute symbol does not need a dynamic relocation.
665 if (this->is_absolute())
668 // An absolute reference within a position-independent output file
669 // will need a dynamic relocation.
670 if ((flags
& ABSOLUTE_REF
)
671 && parameters
->options().output_is_position_independent())
674 // A function call that can branch to a local PLT entry does not need
675 // a dynamic relocation.
676 if ((flags
& FUNCTION_CALL
) && this->has_plt_offset())
679 // A reference to any PLT entry in a non-position-independent executable
680 // does not need a dynamic relocation.
681 if (!(flags
& FUNC_DESC_ABI
)
682 && !parameters
->options().output_is_position_independent()
683 && this->has_plt_offset())
686 // A reference to a symbol defined in a dynamic object or to a
687 // symbol that is preemptible will need a dynamic relocation.
688 if (this->is_from_dynobj()
689 || this->is_undefined()
690 || this->is_preemptible())
693 // For all other cases, return FALSE.
697 // Whether we should use the PLT offset associated with a symbol for
698 // a relocation. FLAGS is a set of Reference_flags.
701 use_plt_offset(int flags
) const
703 // If the symbol doesn't have a PLT offset, then naturally we
704 // don't want to use it.
705 if (!this->has_plt_offset())
708 // For a STT_GNU_IFUNC symbol we always have to use the PLT entry.
709 if (this->type() == elfcpp::STT_GNU_IFUNC
)
712 // If we are going to generate a dynamic relocation, then we will
713 // wind up using that, so no need to use the PLT entry.
714 if (this->needs_dynamic_reloc(flags
))
717 // If the symbol is from a dynamic object, we need to use the PLT
719 if (this->is_from_dynobj())
722 // If we are generating a shared object, and this symbol is
723 // undefined or preemptible, we need to use the PLT entry.
724 if (parameters
->options().shared()
725 && (this->is_undefined() || this->is_preemptible()))
728 // If this is a call to a weak undefined symbol, we need to use
729 // the PLT entry; the symbol may be defined by a library loaded
731 if ((flags
& FUNCTION_CALL
) && this->is_weak_undefined())
734 // Otherwise we can use the regular definition.
738 // Given a direct absolute static relocation against
739 // the global symbol, where a dynamic relocation is needed, this
740 // function returns whether a relative dynamic relocation can be used.
741 // The caller must determine separately whether the static relocation
742 // is compatible with a relative relocation.
745 can_use_relative_reloc(bool is_function_call
) const
747 // A function call that can branch to a local PLT entry can
748 // use a RELATIVE relocation.
749 if (is_function_call
&& this->has_plt_offset())
752 // A reference to a symbol defined in a dynamic object or to a
753 // symbol that is preemptible can not use a RELATIVE relocation.
754 if (this->is_from_dynobj()
755 || this->is_undefined()
756 || this->is_preemptible())
759 // For all other cases, return TRUE.
763 // Return the output section where this symbol is defined. Return
764 // NULL if the symbol has an absolute value.
766 output_section() const;
768 // Set the symbol's output section. This is used for symbols
769 // defined in scripts. This should only be called after the symbol
770 // table has been finalized.
772 set_output_section(Output_section
*);
774 // Return whether there should be a warning for references to this
778 { return this->has_warning_
; }
780 // Mark this symbol as having a warning.
783 { this->has_warning_
= true; }
785 // Return whether this symbol is defined by a COPY reloc from a
788 is_copied_from_dynobj() const
789 { return this->is_copied_from_dynobj_
; }
791 // Mark this symbol as defined by a COPY reloc.
793 set_is_copied_from_dynobj()
794 { this->is_copied_from_dynobj_
= true; }
796 // Return whether this symbol is forced to visibility STB_LOCAL
797 // by a "local:" entry in a version script.
799 is_forced_local() const
800 { return this->is_forced_local_
; }
802 // Mark this symbol as forced to STB_LOCAL visibility.
804 set_is_forced_local()
805 { this->is_forced_local_
= true; }
807 // Return true if this may need a COPY relocation.
808 // References from an executable object to non-function symbols
809 // defined in a dynamic object may need a COPY relocation.
811 may_need_copy_reloc() const
813 return (!parameters
->options().output_is_position_independent()
814 && parameters
->options().copyreloc()
815 && this->is_from_dynobj()
816 && !this->is_func());
819 // Return true if this symbol was predefined by the linker.
821 is_predefined() const
822 { return this->is_predefined_
; }
824 // Return true if this is a C++ vtable symbol.
826 is_cxx_vtable() const
827 { return is_prefix_of("_ZTV", this->name_
); }
830 // Instances of this class should always be created at a specific
833 { memset(this, 0, sizeof *this); }
835 // Initialize the general fields.
837 init_fields(const char* name
, const char* version
,
838 elfcpp::STT type
, elfcpp::STB binding
,
839 elfcpp::STV visibility
, unsigned char nonvis
);
841 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
842 // section index, IS_ORDINARY is whether it is a normal section
843 // index rather than a special code.
844 template<int size
, bool big_endian
>
846 init_base_object(const char* name
, const char* version
, Object
* object
,
847 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
850 // Initialize fields for an Output_data.
852 init_base_output_data(const char* name
, const char* version
, Output_data
*,
853 elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
854 unsigned char nonvis
, bool offset_is_from_end
,
857 // Initialize fields for an Output_segment.
859 init_base_output_segment(const char* name
, const char* version
,
860 Output_segment
* os
, elfcpp::STT type
,
861 elfcpp::STB binding
, elfcpp::STV visibility
,
862 unsigned char nonvis
,
863 Segment_offset_base offset_base
,
866 // Initialize fields for a constant.
868 init_base_constant(const char* name
, const char* version
, elfcpp::STT type
,
869 elfcpp::STB binding
, elfcpp::STV visibility
,
870 unsigned char nonvis
, bool is_predefined
);
872 // Initialize fields for an undefined symbol.
874 init_base_undefined(const char* name
, const char* version
, elfcpp::STT type
,
875 elfcpp::STB binding
, elfcpp::STV visibility
,
876 unsigned char nonvis
);
878 // Override existing symbol.
879 template<int size
, bool big_endian
>
881 override_base(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
882 bool is_ordinary
, Object
* object
, const char* version
);
884 // Override existing symbol with a special symbol.
886 override_base_with_special(const Symbol
* from
);
888 // Override symbol version.
890 override_version(const char* version
);
892 // Allocate a common symbol by giving it a location in the output
895 allocate_base_common(Output_data
*);
898 Symbol(const Symbol
&);
899 Symbol
& operator=(const Symbol
&);
901 // Symbol name (expected to point into a Stringpool).
903 // Symbol version (expected to point into a Stringpool). This may
905 const char* version_
;
909 // This struct is used if SOURCE_ == FROM_OBJECT.
912 // Object in which symbol is defined, or in which it was first
915 // Section number in object_ in which symbol is defined.
919 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
922 // Output_data in which symbol is defined. Before
923 // Layout::finalize the symbol's value is an offset within the
925 Output_data
* output_data
;
926 // True if the offset is from the end, false if the offset is
927 // from the beginning.
928 bool offset_is_from_end
;
931 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
934 // Output_segment in which the symbol is defined. Before
935 // Layout::finalize the symbol's value is an offset.
936 Output_segment
* output_segment
;
937 // The base to use for the offset before Layout::finalize.
938 Segment_offset_base offset_base
;
942 // The index of this symbol in the output file. If the symbol is
943 // not going into the output file, this value is -1U. This field
944 // starts as always holding zero. It is set to a non-zero value by
945 // Symbol_table::finalize.
946 unsigned int symtab_index_
;
948 // The index of this symbol in the dynamic symbol table. If the
949 // symbol is not going into the dynamic symbol table, this value is
950 // -1U. This field starts as always holding zero. It is set to a
951 // non-zero value during Layout::finalize.
952 unsigned int dynsym_index_
;
954 // The GOT section entries for this symbol. A symbol may have more
955 // than one GOT offset (e.g., when mixing modules compiled with two
956 // different TLS models), but will usually have at most one.
957 Got_offset_list got_offsets_
;
959 // If this symbol has an entry in the PLT section, then this is the
960 // offset from the start of the PLT section. This is -1U if there
962 unsigned int plt_offset_
;
964 // Symbol type (bits 0 to 3).
965 elfcpp::STT type_
: 4;
966 // Symbol binding (bits 4 to 7).
967 elfcpp::STB binding_
: 4;
968 // Symbol visibility (bits 8 to 9).
969 elfcpp::STV visibility_
: 2;
970 // Rest of symbol st_other field (bits 10 to 15).
971 unsigned int nonvis_
: 6;
972 // The type of symbol (bits 16 to 18).
974 // True if this is the default version of the symbol (bit 19).
976 // True if this symbol really forwards to another symbol. This is
977 // used when we discover after the fact that two different entries
978 // in the hash table really refer to the same symbol. This will
979 // never be set for a symbol found in the hash table, but may be set
980 // for a symbol found in the list of symbols attached to an Object.
981 // It forwards to the symbol found in the forwarders_ map of
982 // Symbol_table (bit 20).
983 bool is_forwarder_
: 1;
984 // True if the symbol has an alias in the weak_aliases table in
985 // Symbol_table (bit 21).
987 // True if this symbol needs to be in the dynamic symbol table (bit
989 bool needs_dynsym_entry_
: 1;
990 // True if we've seen this symbol in a regular object (bit 23).
992 // True if we've seen this symbol in a dynamic object (bit 24).
994 // True if this is a dynamic symbol which needs a special value in
995 // the dynamic symbol table (bit 25).
996 bool needs_dynsym_value_
: 1;
997 // True if there is a warning for this symbol (bit 26).
998 bool has_warning_
: 1;
999 // True if we are using a COPY reloc for this symbol, so that the
1000 // real definition lives in a dynamic object (bit 27).
1001 bool is_copied_from_dynobj_
: 1;
1002 // True if this symbol was forced to local visibility by a version
1004 bool is_forced_local_
: 1;
1005 // True if the field u_.from_object.shndx is an ordinary section
1006 // index, not one of the special codes from SHN_LORESERVE to
1007 // SHN_HIRESERVE (bit 29).
1008 bool is_ordinary_shndx_
: 1;
1009 // True if we've seen this symbol in a "real" ELF object (bit 30).
1010 // If the symbol has been seen in a relocatable, non-IR, object file,
1011 // it's known to be referenced from outside the IR. A reference from
1012 // a dynamic object doesn't count as a "real" ELF, and we'll simply
1013 // mark the symbol as "visible" from outside the IR. The compiler
1014 // can use this distinction to guide its handling of COMDAT symbols.
1015 bool in_real_elf_
: 1;
1016 // True if this symbol is defined in a section which was discarded
1018 bool is_defined_in_discarded_section_
: 1;
1019 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
1020 bool undef_binding_set_
: 1;
1021 // True if this symbol was a weak undef resolved by a dynamic def
1023 bool undef_binding_weak_
: 1;
1024 // True if this symbol is a predefined linker symbol (bit 34).
1025 bool is_predefined_
: 1;
1028 // The parts of a symbol which are size specific. Using a template
1029 // derived class like this helps us use less space on a 32-bit system.
1032 class Sized_symbol
: public Symbol
1035 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value_type
;
1036 typedef typename
elfcpp::Elf_types
<size
>::Elf_WXword Size_type
;
1041 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
1042 // section index, IS_ORDINARY is whether it is a normal section
1043 // index rather than a special code.
1044 template<bool big_endian
>
1046 init_object(const char* name
, const char* version
, Object
* object
,
1047 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1050 // Initialize fields for an Output_data.
1052 init_output_data(const char* name
, const char* version
, Output_data
*,
1053 Value_type value
, Size_type symsize
, elfcpp::STT
,
1054 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1055 bool offset_is_from_end
, bool is_predefined
);
1057 // Initialize fields for an Output_segment.
1059 init_output_segment(const char* name
, const char* version
, Output_segment
*,
1060 Value_type value
, Size_type symsize
, elfcpp::STT
,
1061 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1062 Segment_offset_base offset_base
, bool is_predefined
);
1064 // Initialize fields for a constant.
1066 init_constant(const char* name
, const char* version
, Value_type value
,
1067 Size_type symsize
, elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
1068 unsigned char nonvis
, bool is_predefined
);
1070 // Initialize fields for an undefined symbol.
1072 init_undefined(const char* name
, const char* version
, elfcpp::STT
,
1073 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
);
1075 // Override existing symbol.
1076 template<bool big_endian
>
1078 override(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1079 bool is_ordinary
, Object
* object
, const char* version
);
1081 // Override existing symbol with a special symbol.
1083 override_with_special(const Sized_symbol
<size
>*);
1085 // Return the symbol's value.
1088 { return this->value_
; }
1090 // Return the symbol's size (we can't call this 'size' because that
1091 // is a template parameter).
1094 { return this->symsize_
; }
1096 // Set the symbol size. This is used when resolving common symbols.
1098 set_symsize(Size_type symsize
)
1099 { this->symsize_
= symsize
; }
1101 // Set the symbol value. This is called when we store the final
1102 // values of the symbols into the symbol table.
1104 set_value(Value_type value
)
1105 { this->value_
= value
; }
1107 // Allocate a common symbol by giving it a location in the output
1110 allocate_common(Output_data
*, Value_type value
);
1113 Sized_symbol(const Sized_symbol
&);
1114 Sized_symbol
& operator=(const Sized_symbol
&);
1116 // Symbol value. Before Layout::finalize this is the offset in the
1117 // input section. This is set to the final value during
1118 // Layout::finalize.
1124 // A struct describing a symbol defined by the linker, where the value
1125 // of the symbol is defined based on an output section. This is used
1126 // for symbols defined by the linker, like "_init_array_start".
1128 struct Define_symbol_in_section
1132 // The name of the output section with which this symbol should be
1133 // associated. If there is no output section with that name, the
1134 // symbol will be defined as zero.
1135 const char* output_section
;
1136 // The offset of the symbol within the output section. This is an
1137 // offset from the start of the output section, unless start_at_end
1138 // is true, in which case this is an offset from the end of the
1141 // The size of the symbol.
1145 // The symbol binding.
1146 elfcpp::STB binding
;
1147 // The symbol visibility.
1148 elfcpp::STV visibility
;
1149 // The rest of the st_other field.
1150 unsigned char nonvis
;
1151 // If true, the value field is an offset from the end of the output
1153 bool offset_is_from_end
;
1154 // If true, this symbol is defined only if we see a reference to it.
1158 // A struct describing a symbol defined by the linker, where the value
1159 // of the symbol is defined based on a segment. This is used for
1160 // symbols defined by the linker, like "_end". We describe the
1161 // segment with which the symbol should be associated by its
1162 // characteristics. If no segment meets these characteristics, the
1163 // symbol will be defined as zero. If there is more than one segment
1164 // which meets these characteristics, we will use the first one.
1166 struct Define_symbol_in_segment
1170 // The segment type where the symbol should be defined, typically
1172 elfcpp::PT segment_type
;
1173 // Bitmask of segment flags which must be set.
1174 elfcpp::PF segment_flags_set
;
1175 // Bitmask of segment flags which must be clear.
1176 elfcpp::PF segment_flags_clear
;
1177 // The offset of the symbol within the segment. The offset is
1178 // calculated from the position set by offset_base.
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 // The base from which we compute the offset.
1191 Symbol::Segment_offset_base offset_base
;
1192 // If true, this symbol is defined only if we see a reference to it.
1196 // Specify an object/section/offset location. Used by ODR code.
1198 struct Symbol_location
1200 // Object where the symbol is defined.
1202 // Section-in-object where the symbol is defined.
1204 // For relocatable objects, offset-in-section where the symbol is defined.
1205 // For dynamic objects, address where the symbol is defined.
1207 bool operator==(const Symbol_location
& that
) const
1209 return (this->object
== that
.object
1210 && this->shndx
== that
.shndx
1211 && this->offset
== that
.offset
);
1215 // This class manages warnings. Warnings are a GNU extension. When
1216 // we see a section named .gnu.warning.SYM in an object file, and if
1217 // we wind using the definition of SYM from that object file, then we
1218 // will issue a warning for any relocation against SYM from a
1219 // different object file. The text of the warning is the contents of
1220 // the section. This is not precisely the definition used by the old
1221 // GNU linker; the old GNU linker treated an occurrence of
1222 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1223 // would trigger a warning on any reference. However, it was
1224 // inconsistent in that a warning in a dynamic object only triggered
1225 // if there was no definition in a regular object. This linker is
1226 // different in that we only issue a warning if we use the symbol
1227 // definition from the same object file as the warning section.
1236 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1239 add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
1240 const std::string
& warning
);
1242 // For each symbol for which we should give a warning, make a note
1245 note_warnings(Symbol_table
* symtab
);
1247 // Issue a warning for a reference to SYM at RELINFO's location.
1248 template<int size
, bool big_endian
>
1250 issue_warning(const Symbol
* sym
, const Relocate_info
<size
, big_endian
>*,
1251 size_t relnum
, off_t reloffset
) const;
1254 Warnings(const Warnings
&);
1255 Warnings
& operator=(const Warnings
&);
1257 // What we need to know to get the warning text.
1258 struct Warning_location
1260 // The object the warning is in.
1262 // The warning text.
1266 : object(NULL
), text()
1270 set(Object
* o
, const std::string
& t
)
1277 // A mapping from warning symbol names (canonicalized in
1278 // Symbol_table's namepool_ field) to warning information.
1279 typedef Unordered_map
<const char*, Warning_location
> Warning_table
;
1281 Warning_table warnings_
;
1284 // The main linker symbol table.
1289 // The different places where a symbol definition can come from.
1292 // Defined in an object file--the normal case.
1294 // Defined for a COPY reloc.
1296 // Defined on the command line using --defsym.
1298 // Defined (so to speak) on the command line using -u.
1300 // Defined in a linker script.
1302 // Predefined by the linker.
1304 // Defined by the linker during an incremental base link, but not
1305 // a predefined symbol (e.g., common, defined in script).
1309 // The order in which we sort common symbols.
1310 enum Sort_commons_order
1312 SORT_COMMONS_BY_SIZE_DESCENDING
,
1313 SORT_COMMONS_BY_ALIGNMENT_DESCENDING
,
1314 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1317 // COUNT is an estimate of how many symbols will be inserted in the
1318 // symbol table. It's ok to put 0 if you don't know; a correct
1319 // guess will just save some CPU by reducing hashtable resizes.
1320 Symbol_table(unsigned int count
, const Version_script_info
& version_script
);
1326 { this->icf_
= icf
;}
1330 { return this->icf_
; }
1332 // Returns true if ICF determined that this is a duplicate section.
1334 is_section_folded(Object
* obj
, unsigned int shndx
) const;
1337 set_gc(Garbage_collection
* gc
)
1342 { return this->gc_
; }
1344 // During garbage collection, this keeps undefined symbols.
1346 gc_mark_undef_symbols(Layout
*);
1348 // This tells garbage collection that this symbol is referenced.
1350 gc_mark_symbol(Symbol
* sym
);
1352 // During garbage collection, this keeps sections that correspond to
1353 // symbols seen in dynamic objects.
1355 gc_mark_dyn_syms(Symbol
* sym
);
1357 // Add COUNT external symbols from the relocatable object RELOBJ to
1358 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1359 // offset in the symbol table of the first symbol, SYM_NAMES is
1360 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1361 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1362 // *DEFINED to the number of defined symbols.
1363 template<int size
, bool big_endian
>
1365 add_from_relobj(Sized_relobj_file
<size
, big_endian
>* relobj
,
1366 const unsigned char* syms
, size_t count
,
1367 size_t symndx_offset
, const char* sym_names
,
1368 size_t sym_name_size
,
1369 typename Sized_relobj_file
<size
, big_endian
>::Symbols
*,
1372 // Add one external symbol from the plugin object OBJ to the symbol table.
1373 // Returns a pointer to the resolved symbol in the symbol table.
1374 template<int size
, bool big_endian
>
1376 add_from_pluginobj(Sized_pluginobj
<size
, big_endian
>* obj
,
1377 const char* name
, const char* ver
,
1378 elfcpp::Sym
<size
, big_endian
>* sym
);
1380 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1381 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1382 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1383 // symbol version data.
1384 template<int size
, bool big_endian
>
1386 add_from_dynobj(Sized_dynobj
<size
, big_endian
>* dynobj
,
1387 const unsigned char* syms
, size_t count
,
1388 const char* sym_names
, size_t sym_name_size
,
1389 const unsigned char* versym
, size_t versym_size
,
1390 const std::vector
<const char*>*,
1391 typename Sized_relobj_file
<size
, big_endian
>::Symbols
*,
1394 // Add one external symbol from the incremental object OBJ to the symbol
1395 // table. Returns a pointer to the resolved symbol in the symbol table.
1396 template<int size
, bool big_endian
>
1398 add_from_incrobj(Object
* obj
, const char* name
,
1399 const char* ver
, elfcpp::Sym
<size
, big_endian
>* sym
);
1401 // Define a special symbol based on an Output_data. It is a
1402 // multiple definition error if this symbol is already defined.
1404 define_in_output_data(const char* name
, const char* version
, Defined
,
1405 Output_data
*, uint64_t value
, uint64_t symsize
,
1406 elfcpp::STT type
, elfcpp::STB binding
,
1407 elfcpp::STV visibility
, unsigned char nonvis
,
1408 bool offset_is_from_end
, bool only_if_ref
);
1410 // Define a special symbol based on an Output_segment. It is a
1411 // multiple definition error if this symbol is already defined.
1413 define_in_output_segment(const char* name
, const char* version
, Defined
,
1414 Output_segment
*, uint64_t value
, uint64_t symsize
,
1415 elfcpp::STT type
, elfcpp::STB binding
,
1416 elfcpp::STV visibility
, unsigned char nonvis
,
1417 Symbol::Segment_offset_base
, bool only_if_ref
);
1419 // Define a special symbol with a constant value. It is a multiple
1420 // definition error if this symbol is already defined.
1422 define_as_constant(const char* name
, const char* version
, Defined
,
1423 uint64_t value
, uint64_t symsize
, elfcpp::STT type
,
1424 elfcpp::STB binding
, elfcpp::STV visibility
,
1425 unsigned char nonvis
, bool only_if_ref
,
1426 bool force_override
);
1428 // Define a set of symbols in output sections. If ONLY_IF_REF is
1429 // true, only define them if they are referenced.
1431 define_symbols(const Layout
*, int count
, const Define_symbol_in_section
*,
1434 // Define a set of symbols in output segments. If ONLY_IF_REF is
1435 // true, only defined them if they are referenced.
1437 define_symbols(const Layout
*, int count
, const Define_symbol_in_segment
*,
1440 // Define SYM using a COPY reloc. POSD is the Output_data where the
1441 // symbol should be defined--typically a .dyn.bss section. VALUE is
1442 // the offset within POSD.
1445 define_with_copy_reloc(Sized_symbol
<size
>* sym
, Output_data
* posd
,
1446 typename
elfcpp::Elf_types
<size
>::Elf_Addr
);
1448 // Look up a symbol.
1450 lookup(const char*, const char* version
= NULL
) const;
1452 // Return the real symbol associated with the forwarder symbol FROM.
1454 resolve_forwards(const Symbol
* from
) const;
1456 // Return the sized version of a symbol in this table.
1459 get_sized_symbol(Symbol
*) const;
1462 const Sized_symbol
<size
>*
1463 get_sized_symbol(const Symbol
*) const;
1465 // Return the count of undefined symbols seen.
1467 saw_undefined() const
1468 { return this->saw_undefined_
; }
1470 // Allocate the common symbols
1472 allocate_commons(Layout
*, Mapfile
*);
1474 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1477 add_warning(const char* name
, Object
* obj
, const std::string
& warning
)
1478 { this->warnings_
.add_warning(this, name
, obj
, warning
); }
1480 // Canonicalize a symbol name for use in the hash table.
1482 canonicalize_name(const char* name
)
1483 { return this->namepool_
.add(name
, true, NULL
); }
1485 // Possibly issue a warning for a reference to SYM at LOCATION which
1487 template<int size
, bool big_endian
>
1489 issue_warning(const Symbol
* sym
,
1490 const Relocate_info
<size
, big_endian
>* relinfo
,
1491 size_t relnum
, off_t reloffset
) const
1492 { this->warnings_
.issue_warning(sym
, relinfo
, relnum
, reloffset
); }
1494 // Check candidate_odr_violations_ to find symbols with the same name
1495 // but apparently different definitions (different source-file/line-no).
1497 detect_odr_violations(const Task
*, const char* output_file_name
) const;
1499 // Add any undefined symbols named on the command line to the symbol
1502 add_undefined_symbols_from_command_line(Layout
*);
1504 // SYM is defined using a COPY reloc. Return the dynamic object
1505 // where the original definition was found.
1507 get_copy_source(const Symbol
* sym
) const;
1509 // Set the dynamic symbol indexes. INDEX is the index of the first
1510 // global dynamic symbol. Pointers to the symbols are stored into
1511 // the vector. The names are stored into the Stringpool. This
1512 // returns an updated dynamic symbol index.
1514 set_dynsym_indexes(unsigned int index
, std::vector
<Symbol
*>*,
1515 Stringpool
*, Versions
*);
1517 // Finalize the symbol table after we have set the final addresses
1518 // of all the input sections. This sets the final symbol indexes,
1519 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1520 // index of the first global symbol. OFF is the file offset of the
1521 // global symbol table, DYNOFF is the offset of the globals in the
1522 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1523 // global dynamic symbol, and DYNCOUNT is the number of global
1524 // dynamic symbols. This records the parameters, and returns the
1525 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1528 finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
, size_t dyncount
,
1529 Stringpool
* pool
, unsigned int* plocal_symcount
);
1531 // Set the final file offset of the symbol table.
1533 set_file_offset(off_t off
)
1534 { this->offset_
= off
; }
1536 // Status code of Symbol_table::compute_final_value.
1537 enum Compute_final_value_status
1541 // Unsupported symbol section.
1542 CFVS_UNSUPPORTED_SYMBOL_SECTION
,
1543 // No output section.
1544 CFVS_NO_OUTPUT_SECTION
1547 // Compute the final value of SYM and store status in location PSTATUS.
1548 // During relaxation, this may be called multiple times for a symbol to
1549 // compute its would-be final value in each relaxation pass.
1552 typename Sized_symbol
<size
>::Value_type
1553 compute_final_value(const Sized_symbol
<size
>* sym
,
1554 Compute_final_value_status
* pstatus
) const;
1556 // Return the index of the first global symbol.
1558 first_global_index() const
1559 { return this->first_global_index_
; }
1561 // Return the total number of symbols in the symbol table.
1563 output_count() const
1564 { return this->output_count_
; }
1566 // Write out the global symbols.
1568 write_globals(const Stringpool
*, const Stringpool
*,
1569 Output_symtab_xindex
*, Output_symtab_xindex
*,
1570 Output_file
*) const;
1572 // Write out a section symbol. Return the updated offset.
1574 write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1575 Output_file
*, off_t
) const;
1577 // Loop over all symbols, applying the function F to each.
1578 template<int size
, typename F
>
1580 for_all_symbols(F f
) const
1582 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1583 p
!= this->table_
.end();
1586 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1591 // Dump statistical information to stderr.
1593 print_stats() const;
1595 // Return the version script information.
1596 const Version_script_info
&
1597 version_script() const
1598 { return version_script_
; }
1601 Symbol_table(const Symbol_table
&);
1602 Symbol_table
& operator=(const Symbol_table
&);
1604 // The type of the list of common symbols.
1605 typedef std::vector
<Symbol
*> Commons_type
;
1607 // The type of the symbol hash table.
1609 typedef std::pair
<Stringpool::Key
, Stringpool::Key
> Symbol_table_key
;
1611 // The hash function. The key values are Stringpool keys.
1612 struct Symbol_table_hash
1615 operator()(const Symbol_table_key
& key
) const
1617 return key
.first
^ key
.second
;
1621 struct Symbol_table_eq
1624 operator()(const Symbol_table_key
&, const Symbol_table_key
&) const;
1627 typedef Unordered_map
<Symbol_table_key
, Symbol
*, Symbol_table_hash
,
1628 Symbol_table_eq
> Symbol_table_type
;
1630 // A map from symbol name (as a pointer into the namepool) to all
1631 // the locations the symbols is (weakly) defined (and certain other
1632 // conditions are met). This map will be used later to detect
1633 // possible One Definition Rule (ODR) violations.
1634 struct Symbol_location_hash
1636 size_t operator()(const Symbol_location
& loc
) const
1637 { return reinterpret_cast<uintptr_t>(loc
.object
) ^ loc
.offset
^ loc
.shndx
; }
1640 typedef Unordered_map
<const char*,
1641 Unordered_set
<Symbol_location
, Symbol_location_hash
> >
1644 // Make FROM a forwarder symbol to TO.
1646 make_forwarder(Symbol
* from
, Symbol
* to
);
1649 template<int size
, bool big_endian
>
1651 add_from_object(Object
*, const char* name
, Stringpool::Key name_key
,
1652 const char* version
, Stringpool::Key version_key
,
1653 bool def
, const elfcpp::Sym
<size
, big_endian
>& sym
,
1654 unsigned int st_shndx
, bool is_ordinary
,
1655 unsigned int orig_st_shndx
);
1657 // Define a default symbol.
1658 template<int size
, bool big_endian
>
1660 define_default_version(Sized_symbol
<size
>*, bool,
1661 Symbol_table_type::iterator
);
1664 template<int size
, bool big_endian
>
1666 resolve(Sized_symbol
<size
>* to
,
1667 const elfcpp::Sym
<size
, big_endian
>& sym
,
1668 unsigned int st_shndx
, bool is_ordinary
,
1669 unsigned int orig_st_shndx
,
1670 Object
*, const char* version
);
1672 template<int size
, bool big_endian
>
1674 resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
);
1676 // Record that a symbol is forced to be local by a version script or
1679 force_local(Symbol
*);
1681 // Adjust NAME and *NAME_KEY for wrapping.
1683 wrap_symbol(const char* name
, Stringpool::Key
* name_key
);
1685 // Whether we should override a symbol, based on flags in
1688 should_override(const Symbol
*, unsigned int, elfcpp::STT
, Defined
,
1689 Object
*, bool*, bool*);
1691 // Report a problem in symbol resolution.
1693 report_resolve_problem(bool is_error
, const char* msg
, const Symbol
* to
,
1694 Defined
, Object
* object
);
1696 // Override a symbol.
1697 template<int size
, bool big_endian
>
1699 override(Sized_symbol
<size
>* tosym
,
1700 const elfcpp::Sym
<size
, big_endian
>& fromsym
,
1701 unsigned int st_shndx
, bool is_ordinary
,
1702 Object
* object
, const char* version
);
1704 // Whether we should override a symbol with a special symbol which
1705 // is automatically defined by the linker.
1707 should_override_with_special(const Symbol
*, elfcpp::STT
, Defined
);
1709 // Override a symbol with a special symbol.
1712 override_with_special(Sized_symbol
<size
>* tosym
,
1713 const Sized_symbol
<size
>* fromsym
);
1715 // Record all weak alias sets for a dynamic object.
1718 record_weak_aliases(std::vector
<Sized_symbol
<size
>*>*);
1720 // Define a special symbol.
1721 template<int size
, bool big_endian
>
1723 define_special_symbol(const char** pname
, const char** pversion
,
1724 bool only_if_ref
, Sized_symbol
<size
>** poldsym
,
1725 bool* resolve_oldsym
);
1727 // Define a symbol in an Output_data, sized version.
1730 do_define_in_output_data(const char* name
, const char* version
, Defined
,
1732 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1733 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1734 elfcpp::STT type
, elfcpp::STB binding
,
1735 elfcpp::STV visibility
, unsigned char nonvis
,
1736 bool offset_is_from_end
, bool only_if_ref
);
1738 // Define a symbol in an Output_segment, sized version.
1741 do_define_in_output_segment(
1742 const char* name
, const char* version
, Defined
, Output_segment
* os
,
1743 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1744 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1745 elfcpp::STT type
, elfcpp::STB binding
,
1746 elfcpp::STV visibility
, unsigned char nonvis
,
1747 Symbol::Segment_offset_base offset_base
, bool only_if_ref
);
1749 // Define a symbol as a constant, sized version.
1752 do_define_as_constant(
1753 const char* name
, const char* version
, Defined
,
1754 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1755 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1756 elfcpp::STT type
, elfcpp::STB binding
,
1757 elfcpp::STV visibility
, unsigned char nonvis
,
1758 bool only_if_ref
, bool force_override
);
1760 // Add any undefined symbols named on the command line to the symbol
1761 // table, sized version.
1764 do_add_undefined_symbols_from_command_line(Layout
*);
1766 // Add one undefined symbol.
1769 add_undefined_symbol_from_command_line(const char* name
);
1771 // Types of common symbols.
1773 enum Commons_section_type
1781 // Allocate the common symbols, sized version.
1784 do_allocate_commons(Layout
*, Mapfile
*, Sort_commons_order
);
1786 // Allocate the common symbols from one list.
1789 do_allocate_commons_list(Layout
*, Commons_section_type
, Commons_type
*,
1790 Mapfile
*, Sort_commons_order
);
1792 // Returns all of the lines attached to LOC, not just the one the
1793 // instruction actually came from. This helps the ODR checker avoid
1795 static std::vector
<std::string
>
1796 linenos_from_loc(const Task
* task
, const Symbol_location
& loc
);
1798 // Implement detect_odr_violations.
1799 template<int size
, bool big_endian
>
1801 sized_detect_odr_violations() const;
1803 // Finalize symbols specialized for size.
1806 sized_finalize(off_t
, Stringpool
*, unsigned int*);
1808 // Finalize a symbol. Return whether it should be added to the
1812 sized_finalize_symbol(Symbol
*);
1814 // Add a symbol the final symtab by setting its index.
1817 add_to_final_symtab(Symbol
*, Stringpool
*, unsigned int* pindex
, off_t
* poff
);
1819 // Write globals specialized for size and endianness.
1820 template<int size
, bool big_endian
>
1822 sized_write_globals(const Stringpool
*, const Stringpool
*,
1823 Output_symtab_xindex
*, Output_symtab_xindex
*,
1824 Output_file
*) const;
1826 // Write out a symbol to P.
1827 template<int size
, bool big_endian
>
1829 sized_write_symbol(Sized_symbol
<size
>*,
1830 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1831 unsigned int shndx
, elfcpp::STB
,
1832 const Stringpool
*, unsigned char* p
) const;
1834 // Possibly warn about an undefined symbol from a dynamic object.
1836 warn_about_undefined_dynobj_symbol(Symbol
*) const;
1838 // Write out a section symbol, specialized for size and endianness.
1839 template<int size
, bool big_endian
>
1841 sized_write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1842 Output_file
*, off_t
) const;
1844 // The type of the list of symbols which have been forced local.
1845 typedef std::vector
<Symbol
*> Forced_locals
;
1847 // A map from symbols with COPY relocs to the dynamic objects where
1848 // they are defined.
1849 typedef Unordered_map
<const Symbol
*, Dynobj
*> Copied_symbol_dynobjs
;
1851 // We increment this every time we see a new undefined symbol, for
1852 // use in archive groups.
1853 size_t saw_undefined_
;
1854 // The index of the first global symbol in the output file.
1855 unsigned int first_global_index_
;
1856 // The file offset within the output symtab section where we should
1859 // The number of global symbols we want to write out.
1860 unsigned int output_count_
;
1861 // The file offset of the global dynamic symbols, or 0 if none.
1862 off_t dynamic_offset_
;
1863 // The index of the first global dynamic symbol.
1864 unsigned int first_dynamic_global_index_
;
1865 // The number of global dynamic symbols, or 0 if none.
1866 unsigned int dynamic_count_
;
1867 // The symbol hash table.
1868 Symbol_table_type table_
;
1869 // A pool of symbol names. This is used for all global symbols.
1870 // Entries in the hash table point into this pool.
1871 Stringpool namepool_
;
1872 // Forwarding symbols.
1873 Unordered_map
<const Symbol
*, Symbol
*> forwarders_
;
1874 // Weak aliases. A symbol in this list points to the next alias.
1875 // The aliases point to each other in a circular list.
1876 Unordered_map
<Symbol
*, Symbol
*> weak_aliases_
;
1877 // We don't expect there to be very many common symbols, so we keep
1878 // a list of them. When we find a common symbol we add it to this
1879 // list. It is possible that by the time we process the list the
1880 // symbol is no longer a common symbol. It may also have become a
1882 Commons_type commons_
;
1883 // This is like the commons_ field, except that it holds TLS common
1885 Commons_type tls_commons_
;
1886 // This is for small common symbols.
1887 Commons_type small_commons_
;
1888 // This is for large common symbols.
1889 Commons_type large_commons_
;
1890 // A list of symbols which have been forced to be local. We don't
1891 // expect there to be very many of them, so we keep a list of them
1892 // rather than walking the whole table to find them.
1893 Forced_locals forced_locals_
;
1894 // Manage symbol warnings.
1896 // Manage potential One Definition Rule (ODR) violations.
1897 Odr_map candidate_odr_violations_
;
1899 // When we emit a COPY reloc for a symbol, we define it in an
1900 // Output_data. When it's time to emit version information for it,
1901 // we need to know the dynamic object in which we found the original
1902 // definition. This maps symbols with COPY relocs to the dynamic
1903 // object where they were defined.
1904 Copied_symbol_dynobjs copied_symbol_dynobjs_
;
1905 // Information parsed from the version script, if any.
1906 const Version_script_info
& version_script_
;
1907 Garbage_collection
* gc_
;
1911 // We inline get_sized_symbol for efficiency.
1915 Symbol_table::get_sized_symbol(Symbol
* sym
) const
1917 gold_assert(size
== parameters
->target().get_size());
1918 return static_cast<Sized_symbol
<size
>*>(sym
);
1922 const Sized_symbol
<size
>*
1923 Symbol_table::get_sized_symbol(const Symbol
* sym
) const
1925 gold_assert(size
== parameters
->target().get_size());
1926 return static_cast<const Sized_symbol
<size
>*>(sym
);
1929 } // End namespace gold.
1931 #endif // !defined(GOLD_SYMTAB_H)