1 // symtab.h -- the gold symbol table -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
34 #include "parameters.h"
35 #include "stringpool.h"
44 template<int size
, bool big_endian
>
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 to 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_
; }
124 // Return whether this version is the default for this symbol name
125 // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only
126 // meaningful for versioned symbols.
130 gold_assert(this->version_
!= NULL
);
131 return this->is_def_
;
134 // Set that this version is the default for this symbol name.
137 { this->is_def_
= true; }
139 // Return the symbol source.
142 { return this->source_
; }
144 // Return the object with which this symbol is associated.
148 gold_assert(this->source_
== FROM_OBJECT
);
149 return this->u_
.from_object
.object
;
152 // Return the index of the section in the input relocatable or
153 // dynamic object file.
155 shndx(bool* is_ordinary
) const
157 gold_assert(this->source_
== FROM_OBJECT
);
158 *is_ordinary
= this->is_ordinary_shndx_
;
159 return this->u_
.from_object
.shndx
;
162 // Return the output data section with which this symbol is
163 // associated, if the symbol was specially defined with respect to
164 // an output data section.
168 gold_assert(this->source_
== IN_OUTPUT_DATA
);
169 return this->u_
.in_output_data
.output_data
;
172 // If this symbol was defined with respect to an output data
173 // section, return whether the value is an offset from end.
175 offset_is_from_end() const
177 gold_assert(this->source_
== IN_OUTPUT_DATA
);
178 return this->u_
.in_output_data
.offset_is_from_end
;
181 // Return the output segment with which this symbol is associated,
182 // if the symbol was specially defined with respect to an output
185 output_segment() const
187 gold_assert(this->source_
== IN_OUTPUT_SEGMENT
);
188 return this->u_
.in_output_segment
.output_segment
;
191 // If this symbol was defined with respect to an output segment,
192 // return the offset base.
196 gold_assert(this->source_
== IN_OUTPUT_SEGMENT
);
197 return this->u_
.in_output_segment
.offset_base
;
200 // Return the symbol binding.
203 { return this->binding_
; }
205 // Return the symbol type.
208 { return this->type_
; }
210 // Return true for function symbol.
214 return (this->type_
== elfcpp::STT_FUNC
215 || this->type_
== elfcpp::STT_GNU_IFUNC
);
218 // Return the symbol visibility.
221 { return this->visibility_
; }
223 // Set the visibility.
225 set_visibility(elfcpp::STV visibility
)
226 { this->visibility_
= visibility
; }
228 // Override symbol visibility.
230 override_visibility(elfcpp::STV
);
232 // Set whether the symbol was originally a weak undef or a regular undef
233 // when resolved by a dynamic def.
235 set_undef_binding(elfcpp::STB bind
)
237 if (!this->undef_binding_set_
|| this->undef_binding_weak_
)
239 this->undef_binding_weak_
= bind
== elfcpp::STB_WEAK
;
240 this->undef_binding_set_
= true;
244 // Return TRUE if a weak undef was resolved by a dynamic def.
246 is_undef_binding_weak() const
247 { return this->undef_binding_weak_
; }
249 // Return the non-visibility part of the st_other field.
252 { return this->nonvis_
; }
254 // Return whether this symbol is a forwarder. This will never be
255 // true of a symbol found in the hash table, but may be true of
256 // symbol pointers attached to object files.
259 { return this->is_forwarder_
; }
261 // Mark this symbol as a forwarder.
264 { this->is_forwarder_
= true; }
266 // Return whether this symbol has an alias in the weak aliases table
270 { return this->has_alias_
; }
272 // Mark this symbol as having an alias.
275 { this->has_alias_
= true; }
277 // Return whether this symbol needs an entry in the dynamic symbol
280 needs_dynsym_entry() const
282 return (this->needs_dynsym_entry_
285 && this->is_externally_visible()));
288 // Mark this symbol as needing an entry in the dynamic symbol table.
290 set_needs_dynsym_entry()
291 { this->needs_dynsym_entry_
= true; }
293 // Return whether this symbol should be added to the dynamic symbol
296 should_add_dynsym_entry(Symbol_table
*) const;
298 // Return whether this symbol has been seen in a regular object.
301 { return this->in_reg_
; }
303 // Mark this symbol as having been seen in a regular object.
306 { this->in_reg_
= true; }
308 // Return whether this symbol has been seen in a dynamic object.
311 { return this->in_dyn_
; }
313 // Mark this symbol as having been seen in a dynamic object.
316 { this->in_dyn_
= true; }
318 // Return whether this symbol has been seen in a real ELF object.
319 // (IN_REG will return TRUE if the symbol has been seen in either
320 // a real ELF object or an object claimed by a plugin.)
323 { return this->in_real_elf_
; }
325 // Mark this symbol as having been seen in a real ELF object.
328 { this->in_real_elf_
= true; }
330 // Return whether this symbol was defined in a section that was
331 // discarded from the link. This is used to control some error
334 is_defined_in_discarded_section() const
335 { return this->is_defined_in_discarded_section_
; }
337 // Mark this symbol as having been defined in a discarded section.
339 set_is_defined_in_discarded_section()
340 { this->is_defined_in_discarded_section_
= true; }
342 // Return the index of this symbol in the output file symbol table.
343 // A value of -1U means that this symbol is not going into the
344 // output file. This starts out as zero, and is set to a non-zero
345 // value by Symbol_table::finalize. It is an error to ask for the
346 // symbol table index before it has been set.
350 gold_assert(this->symtab_index_
!= 0);
351 return this->symtab_index_
;
354 // Set the index of the symbol in the output file symbol table.
356 set_symtab_index(unsigned int index
)
358 gold_assert(index
!= 0);
359 this->symtab_index_
= index
;
362 // Return whether this symbol already has an index in the output
363 // file symbol table.
365 has_symtab_index() const
366 { return this->symtab_index_
!= 0; }
368 // Return the index of this symbol in the dynamic symbol table. A
369 // value of -1U means that this symbol is not going into the dynamic
370 // symbol table. This starts out as zero, and is set to a non-zero
371 // during Layout::finalize. It is an error to ask for the dynamic
372 // symbol table index before it has been set.
376 gold_assert(this->dynsym_index_
!= 0);
377 return this->dynsym_index_
;
380 // Set the index of the symbol in the dynamic symbol table.
382 set_dynsym_index(unsigned int index
)
384 gold_assert(index
!= 0);
385 this->dynsym_index_
= index
;
388 // Return whether this symbol already has an index in the dynamic
391 has_dynsym_index() const
392 { return this->dynsym_index_
!= 0; }
394 // Return whether this symbol has an entry in the GOT section.
395 // For a TLS symbol, this GOT entry will hold its tp-relative offset.
397 has_got_offset(unsigned int got_type
) const
398 { return this->got_offsets_
.get_offset(got_type
) != -1U; }
400 // Return the offset into the GOT section of this symbol.
402 got_offset(unsigned int got_type
) const
404 unsigned int got_offset
= this->got_offsets_
.get_offset(got_type
);
405 gold_assert(got_offset
!= -1U);
409 // Set the GOT offset of this symbol.
411 set_got_offset(unsigned int got_type
, unsigned int got_offset
)
412 { this->got_offsets_
.set_offset(got_type
, got_offset
); }
414 // Return the GOT offset list.
415 const Got_offset_list
*
416 got_offset_list() const
417 { return this->got_offsets_
.get_list(); }
419 // Return whether this symbol has an entry in the PLT section.
421 has_plt_offset() const
422 { return this->plt_offset_
!= -1U; }
424 // Return the offset into the PLT section of this symbol.
428 gold_assert(this->has_plt_offset());
429 return this->plt_offset_
;
432 // Set the PLT offset of this symbol.
434 set_plt_offset(unsigned int plt_offset
)
436 gold_assert(plt_offset
!= -1U);
437 this->plt_offset_
= plt_offset
;
440 // Return whether this dynamic symbol needs a special value in the
441 // dynamic symbol table.
443 needs_dynsym_value() const
444 { return this->needs_dynsym_value_
; }
446 // Set that this dynamic symbol needs a special value in the dynamic
449 set_needs_dynsym_value()
451 gold_assert(this->object()->is_dynamic());
452 this->needs_dynsym_value_
= true;
455 // Return true if the final value of this symbol is known at link
458 final_value_is_known() const;
460 // Return true if SHNDX represents a common symbol. This depends on
463 is_common_shndx(unsigned int shndx
);
465 // Return whether this is a defined symbol (not undefined or
471 if (this->source_
!= FROM_OBJECT
)
472 return this->source_
!= IS_UNDEFINED
;
473 unsigned int shndx
= this->shndx(&is_ordinary
);
475 ? shndx
!= elfcpp::SHN_UNDEF
476 : !Symbol::is_common_shndx(shndx
));
479 // Return true if this symbol is from a dynamic object.
481 is_from_dynobj() const
483 return this->source_
== FROM_OBJECT
&& this->object()->is_dynamic();
486 // Return whether this is a placeholder symbol from a plugin object.
488 is_placeholder() const
490 return this->source_
== FROM_OBJECT
&& this->object()->pluginobj() != NULL
;
493 // Return whether this is an undefined symbol.
498 return ((this->source_
== FROM_OBJECT
499 && this->shndx(&is_ordinary
) == elfcpp::SHN_UNDEF
501 || this->source_
== IS_UNDEFINED
);
504 // Return whether this is a weak undefined symbol.
506 is_weak_undefined() const
507 { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK
; }
509 // Return whether this is an absolute symbol.
514 return ((this->source_
== FROM_OBJECT
515 && this->shndx(&is_ordinary
) == elfcpp::SHN_ABS
517 || this->source_
== IS_CONSTANT
);
520 // Return whether this is a common symbol.
524 if (this->source_
!= FROM_OBJECT
)
526 if (this->type_
== elfcpp::STT_COMMON
)
529 unsigned int shndx
= this->shndx(&is_ordinary
);
530 return !is_ordinary
&& Symbol::is_common_shndx(shndx
);
533 // Return whether this symbol can be seen outside this object.
535 is_externally_visible() const
537 return (this->visibility_
== elfcpp::STV_DEFAULT
538 || this->visibility_
== elfcpp::STV_PROTECTED
);
541 // Return true if this symbol can be preempted by a definition in
542 // another link unit.
544 is_preemptible() const
546 // It doesn't make sense to ask whether a symbol defined in
547 // another object is preemptible.
548 gold_assert(!this->is_from_dynobj());
550 // It doesn't make sense to ask whether an undefined symbol
552 gold_assert(!this->is_undefined());
554 // If a symbol does not have default visibility, it can not be
555 // seen outside this link unit and therefore is not preemptible.
556 if (this->visibility_
!= elfcpp::STV_DEFAULT
)
559 // If this symbol has been forced to be a local symbol by a
560 // version script, then it is not visible outside this link unit
561 // and is not preemptible.
562 if (this->is_forced_local_
)
565 // If we are not producing a shared library, then nothing is
567 if (!parameters
->options().shared())
570 // If the user used -Bsymbolic, then nothing is preemptible.
571 if (parameters
->options().Bsymbolic())
574 // If the user used -Bsymbolic-functions, then functions are not
575 // preemptible. We explicitly check for not being STT_OBJECT,
576 // rather than for being STT_FUNC, because that is what the GNU
578 if (this->type() != elfcpp::STT_OBJECT
579 && parameters
->options().Bsymbolic_functions())
582 // Otherwise the symbol is preemptible.
586 // Return true if this symbol is a function that needs a PLT entry.
588 needs_plt_entry() const
590 // An undefined symbol from an executable does not need a PLT entry.
591 if (this->is_undefined() && !parameters
->options().shared())
594 // An STT_GNU_IFUNC symbol always needs a PLT entry, even when
595 // doing a static link.
596 if (this->type() == elfcpp::STT_GNU_IFUNC
)
599 // We only need a PLT entry for a function.
600 if (!this->is_func())
603 // If we're doing a static link or a -pie link, we don't create
605 if (parameters
->doing_static_link()
606 || parameters
->options().pie())
609 // We need a PLT entry if the function is defined in a dynamic
610 // object, or is undefined when building a shared object, or if it
611 // is subject to pre-emption.
612 return (this->is_from_dynobj()
613 || this->is_undefined()
614 || this->is_preemptible());
617 // When determining whether a reference to a symbol needs a dynamic
618 // relocation, we need to know several things about the reference.
619 // These flags may be or'ed together. 0 means that the symbol
620 // isn't referenced at all.
623 // A reference to the symbol's absolute address. This includes
624 // references that cause an absolute address to be stored in the GOT.
626 // A reference that calculates the offset of the symbol from some
627 // anchor point, such as the PC or GOT.
629 // A TLS-related reference.
631 // A reference that can always be treated as a function call.
635 // Given a direct absolute or pc-relative static relocation against
636 // the global symbol, this function returns whether a dynamic relocation
640 needs_dynamic_reloc(int flags
) const
642 // No dynamic relocations in a static link!
643 if (parameters
->doing_static_link())
646 // A reference to an undefined symbol from an executable should be
647 // statically resolved to 0, and does not need a dynamic relocation.
648 // This matches gnu ld behavior.
649 if (this->is_undefined() && !parameters
->options().shared())
652 // A reference to an absolute symbol does not need a dynamic relocation.
653 if (this->is_absolute())
656 // An absolute reference within a position-independent output file
657 // will need a dynamic relocation.
658 if ((flags
& ABSOLUTE_REF
)
659 && parameters
->options().output_is_position_independent())
662 // A function call that can branch to a local PLT entry does not need
663 // a dynamic relocation.
664 if ((flags
& FUNCTION_CALL
) && this->has_plt_offset())
667 // A reference to any PLT entry in a non-position-independent executable
668 // does not need a dynamic relocation.
669 if (!parameters
->options().output_is_position_independent()
670 && this->has_plt_offset())
673 // A reference to a symbol defined in a dynamic object or to a
674 // symbol that is preemptible will need a dynamic relocation.
675 if (this->is_from_dynobj()
676 || this->is_undefined()
677 || this->is_preemptible())
680 // For all other cases, return FALSE.
684 // Whether we should use the PLT offset associated with a symbol for
685 // a relocation. FLAGS is a set of Reference_flags.
688 use_plt_offset(int flags
) const
690 // If the symbol doesn't have a PLT offset, then naturally we
691 // don't want to use it.
692 if (!this->has_plt_offset())
695 // For a STT_GNU_IFUNC symbol we always have to use the PLT entry.
696 if (this->type() == elfcpp::STT_GNU_IFUNC
)
699 // If we are going to generate a dynamic relocation, then we will
700 // wind up using that, so no need to use the PLT entry.
701 if (this->needs_dynamic_reloc(flags
))
704 // If the symbol is from a dynamic object, we need to use the PLT
706 if (this->is_from_dynobj())
709 // If we are generating a shared object, and this symbol is
710 // undefined or preemptible, we need to use the PLT entry.
711 if (parameters
->options().shared()
712 && (this->is_undefined() || this->is_preemptible()))
715 // If this is a call to a weak undefined symbol, we need to use
716 // the PLT entry; the symbol may be defined by a library loaded
718 if ((flags
& FUNCTION_CALL
) && this->is_weak_undefined())
721 // Otherwise we can use the regular definition.
725 // Given a direct absolute static relocation against
726 // the global symbol, where a dynamic relocation is needed, this
727 // function returns whether a relative dynamic relocation can be used.
728 // The caller must determine separately whether the static relocation
729 // is compatible with a relative relocation.
732 can_use_relative_reloc(bool is_function_call
) const
734 // A function call that can branch to a local PLT entry can
735 // use a RELATIVE relocation.
736 if (is_function_call
&& this->has_plt_offset())
739 // A reference to a symbol defined in a dynamic object or to a
740 // symbol that is preemptible can not use a RELATIVE relocation.
741 if (this->is_from_dynobj()
742 || this->is_undefined()
743 || this->is_preemptible())
746 // For all other cases, return TRUE.
750 // Return the output section where this symbol is defined. Return
751 // NULL if the symbol has an absolute value.
753 output_section() const;
755 // Set the symbol's output section. This is used for symbols
756 // defined in scripts. This should only be called after the symbol
757 // table has been finalized.
759 set_output_section(Output_section
*);
761 // Return whether there should be a warning for references to this
765 { return this->has_warning_
; }
767 // Mark this symbol as having a warning.
770 { this->has_warning_
= true; }
772 // Return whether this symbol is defined by a COPY reloc from a
775 is_copied_from_dynobj() const
776 { return this->is_copied_from_dynobj_
; }
778 // Mark this symbol as defined by a COPY reloc.
780 set_is_copied_from_dynobj()
781 { this->is_copied_from_dynobj_
= true; }
783 // Return whether this symbol is forced to visibility STB_LOCAL
784 // by a "local:" entry in a version script.
786 is_forced_local() const
787 { return this->is_forced_local_
; }
789 // Mark this symbol as forced to STB_LOCAL visibility.
791 set_is_forced_local()
792 { this->is_forced_local_
= true; }
794 // Return true if this may need a COPY relocation.
795 // References from an executable object to non-function symbols
796 // defined in a dynamic object may need a COPY relocation.
798 may_need_copy_reloc() const
800 return (!parameters
->options().output_is_position_independent()
801 && parameters
->options().copyreloc()
802 && this->is_from_dynobj()
803 && !this->is_func());
806 // Return true if this symbol was predefined by the linker.
808 is_predefined() const
809 { return this->is_predefined_
; }
812 // Instances of this class should always be created at a specific
815 { memset(this, 0, sizeof *this); }
817 // Initialize the general fields.
819 init_fields(const char* name
, const char* version
,
820 elfcpp::STT type
, elfcpp::STB binding
,
821 elfcpp::STV visibility
, unsigned char nonvis
);
823 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
824 // section index, IS_ORDINARY is whether it is a normal section
825 // index rather than a special code.
826 template<int size
, bool big_endian
>
828 init_base_object(const char* name
, const char* version
, Object
* object
,
829 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
832 // Initialize fields for an Output_data.
834 init_base_output_data(const char* name
, const char* version
, Output_data
*,
835 elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
836 unsigned char nonvis
, bool offset_is_from_end
,
839 // Initialize fields for an Output_segment.
841 init_base_output_segment(const char* name
, const char* version
,
842 Output_segment
* os
, elfcpp::STT type
,
843 elfcpp::STB binding
, elfcpp::STV visibility
,
844 unsigned char nonvis
,
845 Segment_offset_base offset_base
,
848 // Initialize fields for a constant.
850 init_base_constant(const char* name
, const char* version
, elfcpp::STT type
,
851 elfcpp::STB binding
, elfcpp::STV visibility
,
852 unsigned char nonvis
, bool is_predefined
);
854 // Initialize fields for an undefined symbol.
856 init_base_undefined(const char* name
, const char* version
, elfcpp::STT type
,
857 elfcpp::STB binding
, elfcpp::STV visibility
,
858 unsigned char nonvis
);
860 // Override existing symbol.
861 template<int size
, bool big_endian
>
863 override_base(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
864 bool is_ordinary
, Object
* object
, const char* version
);
866 // Override existing symbol with a special symbol.
868 override_base_with_special(const Symbol
* from
);
870 // Override symbol version.
872 override_version(const char* version
);
874 // Allocate a common symbol by giving it a location in the output
877 allocate_base_common(Output_data
*);
880 Symbol(const Symbol
&);
881 Symbol
& operator=(const Symbol
&);
883 // Symbol name (expected to point into a Stringpool).
885 // Symbol version (expected to point into a Stringpool). This may
887 const char* version_
;
891 // This struct is used if SOURCE_ == FROM_OBJECT.
894 // Object in which symbol is defined, or in which it was first
897 // Section number in object_ in which symbol is defined.
901 // This struct is used if SOURCE_ == IN_OUTPUT_DATA.
904 // Output_data in which symbol is defined. Before
905 // Layout::finalize the symbol's value is an offset within the
907 Output_data
* output_data
;
908 // True if the offset is from the end, false if the offset is
909 // from the beginning.
910 bool offset_is_from_end
;
913 // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT.
916 // Output_segment in which the symbol is defined. Before
917 // Layout::finalize the symbol's value is an offset.
918 Output_segment
* output_segment
;
919 // The base to use for the offset before Layout::finalize.
920 Segment_offset_base offset_base
;
924 // The index of this symbol in the output file. If the symbol is
925 // not going into the output file, this value is -1U. This field
926 // starts as always holding zero. It is set to a non-zero value by
927 // Symbol_table::finalize.
928 unsigned int symtab_index_
;
930 // The index of this symbol in the dynamic symbol table. If the
931 // symbol is not going into the dynamic symbol table, this value is
932 // -1U. This field starts as always holding zero. It is set to a
933 // non-zero value during Layout::finalize.
934 unsigned int dynsym_index_
;
936 // The GOT section entries for this symbol. A symbol may have more
937 // than one GOT offset (e.g., when mixing modules compiled with two
938 // different TLS models), but will usually have at most one.
939 Got_offset_list got_offsets_
;
941 // If this symbol has an entry in the PLT section, then this is the
942 // offset from the start of the PLT section. This is -1U if there
944 unsigned int plt_offset_
;
946 // Symbol type (bits 0 to 3).
947 elfcpp::STT type_
: 4;
948 // Symbol binding (bits 4 to 7).
949 elfcpp::STB binding_
: 4;
950 // Symbol visibility (bits 8 to 9).
951 elfcpp::STV visibility_
: 2;
952 // Rest of symbol st_other field (bits 10 to 15).
953 unsigned int nonvis_
: 6;
954 // The type of symbol (bits 16 to 18).
956 // True if this is the default version of the symbol (bit 19).
958 // True if this symbol really forwards to another symbol. This is
959 // used when we discover after the fact that two different entries
960 // in the hash table really refer to the same symbol. This will
961 // never be set for a symbol found in the hash table, but may be set
962 // for a symbol found in the list of symbols attached to an Object.
963 // It forwards to the symbol found in the forwarders_ map of
964 // Symbol_table (bit 20).
965 bool is_forwarder_
: 1;
966 // True if the symbol has an alias in the weak_aliases table in
967 // Symbol_table (bit 21).
969 // True if this symbol needs to be in the dynamic symbol table (bit
971 bool needs_dynsym_entry_
: 1;
972 // True if we've seen this symbol in a regular object (bit 23).
974 // True if we've seen this symbol in a dynamic object (bit 24).
976 // True if this is a dynamic symbol which needs a special value in
977 // the dynamic symbol table (bit 25).
978 bool needs_dynsym_value_
: 1;
979 // True if there is a warning for this symbol (bit 26).
980 bool has_warning_
: 1;
981 // True if we are using a COPY reloc for this symbol, so that the
982 // real definition lives in a dynamic object (bit 27).
983 bool is_copied_from_dynobj_
: 1;
984 // True if this symbol was forced to local visibility by a version
986 bool is_forced_local_
: 1;
987 // True if the field u_.from_object.shndx is an ordinary section
988 // index, not one of the special codes from SHN_LORESERVE to
989 // SHN_HIRESERVE (bit 29).
990 bool is_ordinary_shndx_
: 1;
991 // True if we've seen this symbol in a real ELF object (bit 30).
992 bool in_real_elf_
: 1;
993 // True if this symbol is defined in a section which was discarded
995 bool is_defined_in_discarded_section_
: 1;
996 // True if UNDEF_BINDING_WEAK_ has been set (bit 32).
997 bool undef_binding_set_
: 1;
998 // True if this symbol was a weak undef resolved by a dynamic def
1000 bool undef_binding_weak_
: 1;
1001 // True if this symbol is a predefined linker symbol (bit 34).
1002 bool is_predefined_
: 1;
1005 // The parts of a symbol which are size specific. Using a template
1006 // derived class like this helps us use less space on a 32-bit system.
1009 class Sized_symbol
: public Symbol
1012 typedef typename
elfcpp::Elf_types
<size
>::Elf_Addr Value_type
;
1013 typedef typename
elfcpp::Elf_types
<size
>::Elf_WXword Size_type
;
1018 // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the
1019 // section index, IS_ORDINARY is whether it is a normal section
1020 // index rather than a special code.
1021 template<bool big_endian
>
1023 init_object(const char* name
, const char* version
, Object
* object
,
1024 const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1027 // Initialize fields for an Output_data.
1029 init_output_data(const char* name
, const char* version
, Output_data
*,
1030 Value_type value
, Size_type symsize
, elfcpp::STT
,
1031 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1032 bool offset_is_from_end
, bool is_predefined
);
1034 // Initialize fields for an Output_segment.
1036 init_output_segment(const char* name
, const char* version
, Output_segment
*,
1037 Value_type value
, Size_type symsize
, elfcpp::STT
,
1038 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
,
1039 Segment_offset_base offset_base
, bool is_predefined
);
1041 // Initialize fields for a constant.
1043 init_constant(const char* name
, const char* version
, Value_type value
,
1044 Size_type symsize
, elfcpp::STT
, elfcpp::STB
, elfcpp::STV
,
1045 unsigned char nonvis
, bool is_predefined
);
1047 // Initialize fields for an undefined symbol.
1049 init_undefined(const char* name
, const char* version
, elfcpp::STT
,
1050 elfcpp::STB
, elfcpp::STV
, unsigned char nonvis
);
1052 // Override existing symbol.
1053 template<bool big_endian
>
1055 override(const elfcpp::Sym
<size
, big_endian
>&, unsigned int st_shndx
,
1056 bool is_ordinary
, Object
* object
, const char* version
);
1058 // Override existing symbol with a special symbol.
1060 override_with_special(const Sized_symbol
<size
>*);
1062 // Return the symbol's value.
1065 { return this->value_
; }
1067 // Return the symbol's size (we can't call this 'size' because that
1068 // is a template parameter).
1071 { return this->symsize_
; }
1073 // Set the symbol size. This is used when resolving common symbols.
1075 set_symsize(Size_type symsize
)
1076 { this->symsize_
= symsize
; }
1078 // Set the symbol value. This is called when we store the final
1079 // values of the symbols into the symbol table.
1081 set_value(Value_type value
)
1082 { this->value_
= value
; }
1084 // Allocate a common symbol by giving it a location in the output
1087 allocate_common(Output_data
*, Value_type value
);
1090 Sized_symbol(const Sized_symbol
&);
1091 Sized_symbol
& operator=(const Sized_symbol
&);
1093 // Symbol value. Before Layout::finalize this is the offset in the
1094 // input section. This is set to the final value during
1095 // Layout::finalize.
1101 // A struct describing a symbol defined by the linker, where the value
1102 // of the symbol is defined based on an output section. This is used
1103 // for symbols defined by the linker, like "_init_array_start".
1105 struct Define_symbol_in_section
1109 // The name of the output section with which this symbol should be
1110 // associated. If there is no output section with that name, the
1111 // symbol will be defined as zero.
1112 const char* output_section
;
1113 // The offset of the symbol within the output section. This is an
1114 // offset from the start of the output section, unless start_at_end
1115 // is true, in which case this is an offset from the end of the
1118 // The size of the symbol.
1122 // The symbol binding.
1123 elfcpp::STB binding
;
1124 // The symbol visibility.
1125 elfcpp::STV visibility
;
1126 // The rest of the st_other field.
1127 unsigned char nonvis
;
1128 // If true, the value field is an offset from the end of the output
1130 bool offset_is_from_end
;
1131 // If true, this symbol is defined only if we see a reference to it.
1135 // A struct describing a symbol defined by the linker, where the value
1136 // of the symbol is defined based on a segment. This is used for
1137 // symbols defined by the linker, like "_end". We describe the
1138 // segment with which the symbol should be associated by its
1139 // characteristics. If no segment meets these characteristics, the
1140 // symbol will be defined as zero. If there is more than one segment
1141 // which meets these characteristics, we will use the first one.
1143 struct Define_symbol_in_segment
1147 // The segment type where the symbol should be defined, typically
1149 elfcpp::PT segment_type
;
1150 // Bitmask of segment flags which must be set.
1151 elfcpp::PF segment_flags_set
;
1152 // Bitmask of segment flags which must be clear.
1153 elfcpp::PF segment_flags_clear
;
1154 // The offset of the symbol within the segment. The offset is
1155 // calculated from the position set by offset_base.
1157 // The size of the symbol.
1161 // The symbol binding.
1162 elfcpp::STB binding
;
1163 // The symbol visibility.
1164 elfcpp::STV visibility
;
1165 // The rest of the st_other field.
1166 unsigned char nonvis
;
1167 // The base from which we compute the offset.
1168 Symbol::Segment_offset_base offset_base
;
1169 // If true, this symbol is defined only if we see a reference to it.
1173 // This class manages warnings. Warnings are a GNU extension. When
1174 // we see a section named .gnu.warning.SYM in an object file, and if
1175 // we wind using the definition of SYM from that object file, then we
1176 // will issue a warning for any relocation against SYM from a
1177 // different object file. The text of the warning is the contents of
1178 // the section. This is not precisely the definition used by the old
1179 // GNU linker; the old GNU linker treated an occurrence of
1180 // .gnu.warning.SYM as defining a warning symbol. A warning symbol
1181 // would trigger a warning on any reference. However, it was
1182 // inconsistent in that a warning in a dynamic object only triggered
1183 // if there was no definition in a regular object. This linker is
1184 // different in that we only issue a warning if we use the symbol
1185 // definition from the same object file as the warning section.
1194 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1197 add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
1198 const std::string
& warning
);
1200 // For each symbol for which we should give a warning, make a note
1203 note_warnings(Symbol_table
* symtab
);
1205 // Issue a warning for a reference to SYM at RELINFO's location.
1206 template<int size
, bool big_endian
>
1208 issue_warning(const Symbol
* sym
, const Relocate_info
<size
, big_endian
>*,
1209 size_t relnum
, off_t reloffset
) const;
1212 Warnings(const Warnings
&);
1213 Warnings
& operator=(const Warnings
&);
1215 // What we need to know to get the warning text.
1216 struct Warning_location
1218 // The object the warning is in.
1220 // The warning text.
1224 : object(NULL
), text()
1228 set(Object
* o
, const std::string
& t
)
1235 // A mapping from warning symbol names (canonicalized in
1236 // Symbol_table's namepool_ field) to warning information.
1237 typedef Unordered_map
<const char*, Warning_location
> Warning_table
;
1239 Warning_table warnings_
;
1242 // The main linker symbol table.
1247 // The different places where a symbol definition can come from.
1250 // Defined in an object file--the normal case.
1252 // Defined for a COPY reloc.
1254 // Defined on the command line using --defsym.
1256 // Defined (so to speak) on the command line using -u.
1258 // Defined in a linker script.
1260 // Predefined by the linker.
1262 // Defined by the linker during an incremental base link, but not
1263 // a predefined symbol (e.g., common, defined in script).
1267 // The order in which we sort common symbols.
1268 enum Sort_commons_order
1270 SORT_COMMONS_BY_SIZE_DESCENDING
,
1271 SORT_COMMONS_BY_ALIGNMENT_DESCENDING
,
1272 SORT_COMMONS_BY_ALIGNMENT_ASCENDING
1275 // COUNT is an estimate of how many symbols will be inserted in the
1276 // symbol table. It's ok to put 0 if you don't know; a correct
1277 // guess will just save some CPU by reducing hashtable resizes.
1278 Symbol_table(unsigned int count
, const Version_script_info
& version_script
);
1284 { this->icf_
= icf
;}
1288 { return this->icf_
; }
1290 // Returns true if ICF determined that this is a duplicate section.
1292 is_section_folded(Object
* obj
, unsigned int shndx
) const;
1295 set_gc(Garbage_collection
* gc
)
1300 { return this->gc_
; }
1302 // During garbage collection, this keeps undefined symbols.
1304 gc_mark_undef_symbols(Layout
*);
1306 // During garbage collection, this ensures externally visible symbols
1307 // are not treated as garbage while building shared objects.
1309 gc_mark_symbol_for_shlib(Symbol
* sym
);
1311 // During garbage collection, this keeps sections that correspond to
1312 // symbols seen in dynamic objects.
1314 gc_mark_dyn_syms(Symbol
* sym
);
1316 // Add COUNT external symbols from the relocatable object RELOBJ to
1317 // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
1318 // offset in the symbol table of the first symbol, SYM_NAMES is
1319 // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
1320 // SYMPOINTERS to point to the symbols in the symbol table. It sets
1321 // *DEFINED to the number of defined symbols.
1322 template<int size
, bool big_endian
>
1324 add_from_relobj(Sized_relobj_file
<size
, big_endian
>* relobj
,
1325 const unsigned char* syms
, size_t count
,
1326 size_t symndx_offset
, const char* sym_names
,
1327 size_t sym_name_size
,
1328 typename Sized_relobj_file
<size
, big_endian
>::Symbols
*,
1331 // Add one external symbol from the plugin object OBJ to the symbol table.
1332 // Returns a pointer to the resolved symbol in the symbol table.
1333 template<int size
, bool big_endian
>
1335 add_from_pluginobj(Sized_pluginobj
<size
, big_endian
>* obj
,
1336 const char* name
, const char* ver
,
1337 elfcpp::Sym
<size
, big_endian
>* sym
);
1339 // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
1340 // symbol table. SYMS is the symbols. SYM_NAMES is their names.
1341 // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are
1342 // symbol version data.
1343 template<int size
, bool big_endian
>
1345 add_from_dynobj(Sized_dynobj
<size
, big_endian
>* dynobj
,
1346 const unsigned char* syms
, size_t count
,
1347 const char* sym_names
, size_t sym_name_size
,
1348 const unsigned char* versym
, size_t versym_size
,
1349 const std::vector
<const char*>*,
1350 typename Sized_relobj_file
<size
, big_endian
>::Symbols
*,
1353 // Add one external symbol from the incremental object OBJ to the symbol
1354 // table. Returns a pointer to the resolved symbol in the symbol table.
1355 template<int size
, bool big_endian
>
1357 add_from_incrobj(Object
* obj
, const char* name
,
1358 const char* ver
, elfcpp::Sym
<size
, big_endian
>* sym
);
1360 // Define a special symbol based on an Output_data. It is a
1361 // multiple definition error if this symbol is already defined.
1363 define_in_output_data(const char* name
, const char* version
, Defined
,
1364 Output_data
*, uint64_t value
, uint64_t symsize
,
1365 elfcpp::STT type
, elfcpp::STB binding
,
1366 elfcpp::STV visibility
, unsigned char nonvis
,
1367 bool offset_is_from_end
, bool only_if_ref
);
1369 // Define a special symbol based on an Output_segment. It is a
1370 // multiple definition error if this symbol is already defined.
1372 define_in_output_segment(const char* name
, const char* version
, Defined
,
1373 Output_segment
*, uint64_t value
, uint64_t symsize
,
1374 elfcpp::STT type
, elfcpp::STB binding
,
1375 elfcpp::STV visibility
, unsigned char nonvis
,
1376 Symbol::Segment_offset_base
, bool only_if_ref
);
1378 // Define a special symbol with a constant value. It is a multiple
1379 // definition error if this symbol is already defined.
1381 define_as_constant(const char* name
, const char* version
, Defined
,
1382 uint64_t value
, uint64_t symsize
, elfcpp::STT type
,
1383 elfcpp::STB binding
, elfcpp::STV visibility
,
1384 unsigned char nonvis
, bool only_if_ref
,
1385 bool force_override
);
1387 // Define a set of symbols in output sections. If ONLY_IF_REF is
1388 // true, only define them if they are referenced.
1390 define_symbols(const Layout
*, int count
, const Define_symbol_in_section
*,
1393 // Define a set of symbols in output segments. If ONLY_IF_REF is
1394 // true, only defined them if they are referenced.
1396 define_symbols(const Layout
*, int count
, const Define_symbol_in_segment
*,
1399 // Define SYM using a COPY reloc. POSD is the Output_data where the
1400 // symbol should be defined--typically a .dyn.bss section. VALUE is
1401 // the offset within POSD.
1404 define_with_copy_reloc(Sized_symbol
<size
>* sym
, Output_data
* posd
,
1405 typename
elfcpp::Elf_types
<size
>::Elf_Addr
);
1407 // Look up a symbol.
1409 lookup(const char*, const char* version
= NULL
) const;
1411 // Return the real symbol associated with the forwarder symbol FROM.
1413 resolve_forwards(const Symbol
* from
) const;
1415 // Return the sized version of a symbol in this table.
1418 get_sized_symbol(Symbol
*) const;
1421 const Sized_symbol
<size
>*
1422 get_sized_symbol(const Symbol
*) const;
1424 // Return the count of undefined symbols seen.
1426 saw_undefined() const
1427 { return this->saw_undefined_
; }
1429 // Allocate the common symbols
1431 allocate_commons(Layout
*, Mapfile
*);
1433 // Add a warning for symbol NAME in object OBJ. WARNING is the text
1436 add_warning(const char* name
, Object
* obj
, const std::string
& warning
)
1437 { this->warnings_
.add_warning(this, name
, obj
, warning
); }
1439 // Canonicalize a symbol name for use in the hash table.
1441 canonicalize_name(const char* name
)
1442 { return this->namepool_
.add(name
, true, NULL
); }
1444 // Possibly issue a warning for a reference to SYM at LOCATION which
1446 template<int size
, bool big_endian
>
1448 issue_warning(const Symbol
* sym
,
1449 const Relocate_info
<size
, big_endian
>* relinfo
,
1450 size_t relnum
, off_t reloffset
) const
1451 { this->warnings_
.issue_warning(sym
, relinfo
, relnum
, reloffset
); }
1453 // Check candidate_odr_violations_ to find symbols with the same name
1454 // but apparently different definitions (different source-file/line-no).
1456 detect_odr_violations(const Task
*, const char* output_file_name
) const;
1458 // Add any undefined symbols named on the command line to the symbol
1461 add_undefined_symbols_from_command_line(Layout
*);
1463 // SYM is defined using a COPY reloc. Return the dynamic object
1464 // where the original definition was found.
1466 get_copy_source(const Symbol
* sym
) const;
1468 // Set the dynamic symbol indexes. INDEX is the index of the first
1469 // global dynamic symbol. Pointers to the symbols are stored into
1470 // the vector. The names are stored into the Stringpool. This
1471 // returns an updated dynamic symbol index.
1473 set_dynsym_indexes(unsigned int index
, std::vector
<Symbol
*>*,
1474 Stringpool
*, Versions
*);
1476 // Finalize the symbol table after we have set the final addresses
1477 // of all the input sections. This sets the final symbol indexes,
1478 // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the
1479 // index of the first global symbol. OFF is the file offset of the
1480 // global symbol table, DYNOFF is the offset of the globals in the
1481 // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first
1482 // global dynamic symbol, and DYNCOUNT is the number of global
1483 // dynamic symbols. This records the parameters, and returns the
1484 // new file offset. It updates *PLOCAL_SYMCOUNT if it created any
1487 finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
, size_t dyncount
,
1488 Stringpool
* pool
, unsigned int* plocal_symcount
);
1490 // Set the final file offset of the symbol table.
1492 set_file_offset(off_t off
)
1493 { this->offset_
= off
; }
1495 // Status code of Symbol_table::compute_final_value.
1496 enum Compute_final_value_status
1500 // Unsupported symbol section.
1501 CFVS_UNSUPPORTED_SYMBOL_SECTION
,
1502 // No output section.
1503 CFVS_NO_OUTPUT_SECTION
1506 // Compute the final value of SYM and store status in location PSTATUS.
1507 // During relaxation, this may be called multiple times for a symbol to
1508 // compute its would-be final value in each relaxation pass.
1511 typename Sized_symbol
<size
>::Value_type
1512 compute_final_value(const Sized_symbol
<size
>* sym
,
1513 Compute_final_value_status
* pstatus
) const;
1515 // Return the index of the first global symbol.
1517 first_global_index() const
1518 { return this->first_global_index_
; }
1520 // Return the total number of symbols in the symbol table.
1522 output_count() const
1523 { return this->output_count_
; }
1525 // Write out the global symbols.
1527 write_globals(const Stringpool
*, const Stringpool
*,
1528 Output_symtab_xindex
*, Output_symtab_xindex
*,
1529 Output_file
*) const;
1531 // Write out a section symbol. Return the updated offset.
1533 write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1534 Output_file
*, off_t
) const;
1536 // Loop over all symbols, applying the function F to each.
1537 template<int size
, typename F
>
1539 for_all_symbols(F f
) const
1541 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1542 p
!= this->table_
.end();
1545 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1550 // Dump statistical information to stderr.
1552 print_stats() const;
1554 // Return the version script information.
1555 const Version_script_info
&
1556 version_script() const
1557 { return version_script_
; }
1560 Symbol_table(const Symbol_table
&);
1561 Symbol_table
& operator=(const Symbol_table
&);
1563 // The type of the list of common symbols.
1564 typedef std::vector
<Symbol
*> Commons_type
;
1566 // The type of the symbol hash table.
1568 typedef std::pair
<Stringpool::Key
, Stringpool::Key
> Symbol_table_key
;
1570 // The hash function. The key values are Stringpool keys.
1571 struct Symbol_table_hash
1574 operator()(const Symbol_table_key
& key
) const
1576 return key
.first
^ key
.second
;
1580 struct Symbol_table_eq
1583 operator()(const Symbol_table_key
&, const Symbol_table_key
&) const;
1586 typedef Unordered_map
<Symbol_table_key
, Symbol
*, Symbol_table_hash
,
1587 Symbol_table_eq
> Symbol_table_type
;
1589 // A map from symbol name (as a pointer into the namepool) to all
1590 // the locations the symbols is (weakly) defined (and certain other
1591 // conditions are met). This map will be used later to detect
1592 // possible One Definition Rule (ODR) violations.
1593 struct Symbol_location
1595 Object
* object
; // Object where the symbol is defined.
1596 unsigned int shndx
; // Section-in-object where the symbol is defined.
1597 off_t offset
; // Offset-in-section where the symbol is defined.
1598 bool operator==(const Symbol_location
& that
) const
1600 return (this->object
== that
.object
1601 && this->shndx
== that
.shndx
1602 && this->offset
== that
.offset
);
1606 struct Symbol_location_hash
1608 size_t operator()(const Symbol_location
& loc
) const
1609 { return reinterpret_cast<uintptr_t>(loc
.object
) ^ loc
.offset
^ loc
.shndx
; }
1612 typedef Unordered_map
<const char*,
1613 Unordered_set
<Symbol_location
, Symbol_location_hash
> >
1616 // Make FROM a forwarder symbol to TO.
1618 make_forwarder(Symbol
* from
, Symbol
* to
);
1621 template<int size
, bool big_endian
>
1623 add_from_object(Object
*, const char* name
, Stringpool::Key name_key
,
1624 const char* version
, Stringpool::Key version_key
,
1625 bool def
, const elfcpp::Sym
<size
, big_endian
>& sym
,
1626 unsigned int st_shndx
, bool is_ordinary
,
1627 unsigned int orig_st_shndx
);
1629 // Define a default symbol.
1630 template<int size
, bool big_endian
>
1632 define_default_version(Sized_symbol
<size
>*, bool,
1633 Symbol_table_type::iterator
);
1636 template<int size
, bool big_endian
>
1638 resolve(Sized_symbol
<size
>* to
,
1639 const elfcpp::Sym
<size
, big_endian
>& sym
,
1640 unsigned int st_shndx
, bool is_ordinary
,
1641 unsigned int orig_st_shndx
,
1642 Object
*, const char* version
);
1644 template<int size
, bool big_endian
>
1646 resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
);
1648 // Record that a symbol is forced to be local by a version script or
1651 force_local(Symbol
*);
1653 // Adjust NAME and *NAME_KEY for wrapping.
1655 wrap_symbol(const char* name
, Stringpool::Key
* name_key
);
1657 // Whether we should override a symbol, based on flags in
1660 should_override(const Symbol
*, unsigned int, Defined
, Object
*, bool*, bool*);
1662 // Report a problem in symbol resolution.
1664 report_resolve_problem(bool is_error
, const char* msg
, const Symbol
* to
,
1665 Defined
, Object
* object
);
1667 // Override a symbol.
1668 template<int size
, bool big_endian
>
1670 override(Sized_symbol
<size
>* tosym
,
1671 const elfcpp::Sym
<size
, big_endian
>& fromsym
,
1672 unsigned int st_shndx
, bool is_ordinary
,
1673 Object
* object
, const char* version
);
1675 // Whether we should override a symbol with a special symbol which
1676 // is automatically defined by the linker.
1678 should_override_with_special(const Symbol
*, Defined
);
1680 // Override a symbol with a special symbol.
1683 override_with_special(Sized_symbol
<size
>* tosym
,
1684 const Sized_symbol
<size
>* fromsym
);
1686 // Record all weak alias sets for a dynamic object.
1689 record_weak_aliases(std::vector
<Sized_symbol
<size
>*>*);
1691 // Define a special symbol.
1692 template<int size
, bool big_endian
>
1694 define_special_symbol(const char** pname
, const char** pversion
,
1695 bool only_if_ref
, Sized_symbol
<size
>** poldsym
,
1696 bool* resolve_oldsym
);
1698 // Define a symbol in an Output_data, sized version.
1701 do_define_in_output_data(const char* name
, const char* version
, Defined
,
1703 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1704 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1705 elfcpp::STT type
, elfcpp::STB binding
,
1706 elfcpp::STV visibility
, unsigned char nonvis
,
1707 bool offset_is_from_end
, bool only_if_ref
);
1709 // Define a symbol in an Output_segment, sized version.
1712 do_define_in_output_segment(
1713 const char* name
, const char* version
, Defined
, Output_segment
* os
,
1714 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1715 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1716 elfcpp::STT type
, elfcpp::STB binding
,
1717 elfcpp::STV visibility
, unsigned char nonvis
,
1718 Symbol::Segment_offset_base offset_base
, bool only_if_ref
);
1720 // Define a symbol as a constant, sized version.
1723 do_define_as_constant(
1724 const char* name
, const char* version
, Defined
,
1725 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1726 typename
elfcpp::Elf_types
<size
>::Elf_WXword ssize
,
1727 elfcpp::STT type
, elfcpp::STB binding
,
1728 elfcpp::STV visibility
, unsigned char nonvis
,
1729 bool only_if_ref
, bool force_override
);
1731 // Add any undefined symbols named on the command line to the symbol
1732 // table, sized version.
1735 do_add_undefined_symbols_from_command_line(Layout
*);
1737 // Add one undefined symbol.
1740 add_undefined_symbol_from_command_line(const char* name
);
1742 // Types of common symbols.
1744 enum Commons_section_type
1752 // Allocate the common symbols, sized version.
1755 do_allocate_commons(Layout
*, Mapfile
*, Sort_commons_order
);
1757 // Allocate the common symbols from one list.
1760 do_allocate_commons_list(Layout
*, Commons_section_type
, Commons_type
*,
1761 Mapfile
*, Sort_commons_order
);
1763 // Returns all of the lines attached to LOC, not just the one the
1764 // instruction actually came from. This helps the ODR checker avoid
1766 static std::vector
<std::string
>
1767 linenos_from_loc(const Task
* task
, const Symbol_location
& loc
);
1769 // Implement detect_odr_violations.
1770 template<int size
, bool big_endian
>
1772 sized_detect_odr_violations() const;
1774 // Finalize symbols specialized for size.
1777 sized_finalize(off_t
, Stringpool
*, unsigned int*);
1779 // Finalize a symbol. Return whether it should be added to the
1783 sized_finalize_symbol(Symbol
*);
1785 // Add a symbol the final symtab by setting its index.
1788 add_to_final_symtab(Symbol
*, Stringpool
*, unsigned int* pindex
, off_t
* poff
);
1790 // Write globals specialized for size and endianness.
1791 template<int size
, bool big_endian
>
1793 sized_write_globals(const Stringpool
*, const Stringpool
*,
1794 Output_symtab_xindex
*, Output_symtab_xindex
*,
1795 Output_file
*) const;
1797 // Write out a symbol to P.
1798 template<int size
, bool big_endian
>
1800 sized_write_symbol(Sized_symbol
<size
>*,
1801 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1802 unsigned int shndx
, elfcpp::STB
,
1803 const Stringpool
*, unsigned char* p
) const;
1805 // Possibly warn about an undefined symbol from a dynamic object.
1807 warn_about_undefined_dynobj_symbol(Symbol
*) const;
1809 // Write out a section symbol, specialized for size and endianness.
1810 template<int size
, bool big_endian
>
1812 sized_write_section_symbol(const Output_section
*, Output_symtab_xindex
*,
1813 Output_file
*, off_t
) const;
1815 // The type of the list of symbols which have been forced local.
1816 typedef std::vector
<Symbol
*> Forced_locals
;
1818 // A map from symbols with COPY relocs to the dynamic objects where
1819 // they are defined.
1820 typedef Unordered_map
<const Symbol
*, Dynobj
*> Copied_symbol_dynobjs
;
1822 // We increment this every time we see a new undefined symbol, for
1823 // use in archive groups.
1824 size_t saw_undefined_
;
1825 // The index of the first global symbol in the output file.
1826 unsigned int first_global_index_
;
1827 // The file offset within the output symtab section where we should
1830 // The number of global symbols we want to write out.
1831 unsigned int output_count_
;
1832 // The file offset of the global dynamic symbols, or 0 if none.
1833 off_t dynamic_offset_
;
1834 // The index of the first global dynamic symbol.
1835 unsigned int first_dynamic_global_index_
;
1836 // The number of global dynamic symbols, or 0 if none.
1837 unsigned int dynamic_count_
;
1838 // The symbol hash table.
1839 Symbol_table_type table_
;
1840 // A pool of symbol names. This is used for all global symbols.
1841 // Entries in the hash table point into this pool.
1842 Stringpool namepool_
;
1843 // Forwarding symbols.
1844 Unordered_map
<const Symbol
*, Symbol
*> forwarders_
;
1845 // Weak aliases. A symbol in this list points to the next alias.
1846 // The aliases point to each other in a circular list.
1847 Unordered_map
<Symbol
*, Symbol
*> weak_aliases_
;
1848 // We don't expect there to be very many common symbols, so we keep
1849 // a list of them. When we find a common symbol we add it to this
1850 // list. It is possible that by the time we process the list the
1851 // symbol is no longer a common symbol. It may also have become a
1853 Commons_type commons_
;
1854 // This is like the commons_ field, except that it holds TLS common
1856 Commons_type tls_commons_
;
1857 // This is for small common symbols.
1858 Commons_type small_commons_
;
1859 // This is for large common symbols.
1860 Commons_type large_commons_
;
1861 // A list of symbols which have been forced to be local. We don't
1862 // expect there to be very many of them, so we keep a list of them
1863 // rather than walking the whole table to find them.
1864 Forced_locals forced_locals_
;
1865 // Manage symbol warnings.
1867 // Manage potential One Definition Rule (ODR) violations.
1868 Odr_map candidate_odr_violations_
;
1870 // When we emit a COPY reloc for a symbol, we define it in an
1871 // Output_data. When it's time to emit version information for it,
1872 // we need to know the dynamic object in which we found the original
1873 // definition. This maps symbols with COPY relocs to the dynamic
1874 // object where they were defined.
1875 Copied_symbol_dynobjs copied_symbol_dynobjs_
;
1876 // Information parsed from the version script, if any.
1877 const Version_script_info
& version_script_
;
1878 Garbage_collection
* gc_
;
1882 // We inline get_sized_symbol for efficiency.
1886 Symbol_table::get_sized_symbol(Symbol
* sym
) const
1888 gold_assert(size
== parameters
->target().get_size());
1889 return static_cast<Sized_symbol
<size
>*>(sym
);
1893 const Sized_symbol
<size
>*
1894 Symbol_table::get_sized_symbol(const Symbol
* sym
) const
1896 gold_assert(size
== parameters
->target().get_size());
1897 return static_cast<const Sized_symbol
<size
>*>(sym
);
1900 } // End namespace gold.
1902 #endif // !defined(GOLD_SYMTAB_H)