1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007, 2008 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.
32 #include "dwarf_reader.h"
36 #include "workqueue.h"
44 // Initialize fields in Symbol. This initializes everything except u_
48 Symbol::init_fields(const char* name
, const char* version
,
49 elfcpp::STT type
, elfcpp::STB binding
,
50 elfcpp::STV visibility
, unsigned char nonvis
)
53 this->version_
= version
;
54 this->symtab_index_
= 0;
55 this->dynsym_index_
= 0;
56 this->got_offset_
= 0;
57 this->plt_offset_
= 0;
59 this->binding_
= binding
;
60 this->visibility_
= visibility
;
61 this->nonvis_
= nonvis
;
62 this->is_target_special_
= false;
63 this->is_def_
= false;
64 this->is_forwarder_
= false;
65 this->has_alias_
= false;
66 this->needs_dynsym_entry_
= false;
67 this->in_reg_
= false;
68 this->in_dyn_
= false;
69 this->has_got_offset_
= false;
70 this->has_plt_offset_
= false;
71 this->has_warning_
= false;
72 this->is_copied_from_dynobj_
= false;
73 this->is_forced_local_
= false;
76 // Return the demangled version of the symbol's name, but only
77 // if the --demangle flag was set.
80 demangle(const char* name
)
82 if (!parameters
->demangle())
85 // cplus_demangle allocates memory for the result it returns,
86 // and returns NULL if the name is already demangled.
87 char* demangled_name
= cplus_demangle(name
, DMGL_ANSI
| DMGL_PARAMS
);
88 if (demangled_name
== NULL
)
91 std::string
retval(demangled_name
);
97 Symbol::demangled_name() const
99 return demangle(this->name());
102 // Initialize the fields in the base class Symbol for SYM in OBJECT.
104 template<int size
, bool big_endian
>
106 Symbol::init_base(const char* name
, const char* version
, Object
* object
,
107 const elfcpp::Sym
<size
, big_endian
>& sym
)
109 this->init_fields(name
, version
, sym
.get_st_type(), sym
.get_st_bind(),
110 sym
.get_st_visibility(), sym
.get_st_nonvis());
111 this->u_
.from_object
.object
= object
;
112 // FIXME: Handle SHN_XINDEX.
113 this->u_
.from_object
.shndx
= sym
.get_st_shndx();
114 this->source_
= FROM_OBJECT
;
115 this->in_reg_
= !object
->is_dynamic();
116 this->in_dyn_
= object
->is_dynamic();
119 // Initialize the fields in the base class Symbol for a symbol defined
120 // in an Output_data.
123 Symbol::init_base(const char* name
, Output_data
* od
, elfcpp::STT type
,
124 elfcpp::STB binding
, elfcpp::STV visibility
,
125 unsigned char nonvis
, bool offset_is_from_end
)
127 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
128 this->u_
.in_output_data
.output_data
= od
;
129 this->u_
.in_output_data
.offset_is_from_end
= offset_is_from_end
;
130 this->source_
= IN_OUTPUT_DATA
;
131 this->in_reg_
= true;
134 // Initialize the fields in the base class Symbol for a symbol defined
135 // in an Output_segment.
138 Symbol::init_base(const char* name
, Output_segment
* os
, elfcpp::STT type
,
139 elfcpp::STB binding
, elfcpp::STV visibility
,
140 unsigned char nonvis
, Segment_offset_base offset_base
)
142 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
143 this->u_
.in_output_segment
.output_segment
= os
;
144 this->u_
.in_output_segment
.offset_base
= offset_base
;
145 this->source_
= IN_OUTPUT_SEGMENT
;
146 this->in_reg_
= true;
149 // Initialize the fields in the base class Symbol for a symbol defined
153 Symbol::init_base(const char* name
, elfcpp::STT type
,
154 elfcpp::STB binding
, elfcpp::STV visibility
,
155 unsigned char nonvis
)
157 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
158 this->source_
= CONSTANT
;
159 this->in_reg_
= true;
162 // Allocate a common symbol in the base.
165 Symbol::allocate_base_common(Output_data
* od
)
167 gold_assert(this->is_common());
168 this->source_
= IN_OUTPUT_DATA
;
169 this->u_
.in_output_data
.output_data
= od
;
170 this->u_
.in_output_data
.offset_is_from_end
= false;
173 // Initialize the fields in Sized_symbol for SYM in OBJECT.
176 template<bool big_endian
>
178 Sized_symbol
<size
>::init(const char* name
, const char* version
, Object
* object
,
179 const elfcpp::Sym
<size
, big_endian
>& sym
)
181 this->init_base(name
, version
, object
, sym
);
182 this->value_
= sym
.get_st_value();
183 this->symsize_
= sym
.get_st_size();
186 // Initialize the fields in Sized_symbol for a symbol defined in an
191 Sized_symbol
<size
>::init(const char* name
, Output_data
* od
,
192 Value_type value
, Size_type symsize
,
193 elfcpp::STT type
, elfcpp::STB binding
,
194 elfcpp::STV visibility
, unsigned char nonvis
,
195 bool offset_is_from_end
)
197 this->init_base(name
, od
, type
, binding
, visibility
, nonvis
,
199 this->value_
= value
;
200 this->symsize_
= symsize
;
203 // Initialize the fields in Sized_symbol for a symbol defined in an
208 Sized_symbol
<size
>::init(const char* name
, Output_segment
* os
,
209 Value_type value
, Size_type symsize
,
210 elfcpp::STT type
, elfcpp::STB binding
,
211 elfcpp::STV visibility
, unsigned char nonvis
,
212 Segment_offset_base offset_base
)
214 this->init_base(name
, os
, type
, binding
, visibility
, nonvis
, offset_base
);
215 this->value_
= value
;
216 this->symsize_
= symsize
;
219 // Initialize the fields in Sized_symbol for a symbol defined as a
224 Sized_symbol
<size
>::init(const char* name
, Value_type value
, Size_type symsize
,
225 elfcpp::STT type
, elfcpp::STB binding
,
226 elfcpp::STV visibility
, unsigned char nonvis
)
228 this->init_base(name
, type
, binding
, visibility
, nonvis
);
229 this->value_
= value
;
230 this->symsize_
= symsize
;
233 // Allocate a common symbol.
237 Sized_symbol
<size
>::allocate_common(Output_data
* od
, Value_type value
)
239 this->allocate_base_common(od
);
240 this->value_
= value
;
243 // Return true if this symbol should be added to the dynamic symbol
247 Symbol::should_add_dynsym_entry() const
249 // If the symbol is used by a dynamic relocation, we need to add it.
250 if (this->needs_dynsym_entry())
253 // If the symbol was forced local in a version script, do not add it.
254 if (this->is_forced_local())
257 // If exporting all symbols or building a shared library,
258 // and the symbol is defined in a regular object and is
259 // externally visible, we need to add it.
260 if ((parameters
->export_dynamic() || parameters
->output_is_shared())
261 && !this->is_from_dynobj()
262 && this->is_externally_visible())
268 // Return true if the final value of this symbol is known at link
272 Symbol::final_value_is_known() const
274 // If we are not generating an executable, then no final values are
275 // known, since they will change at runtime.
276 if (!parameters
->output_is_executable())
279 // If the symbol is not from an object file, then it is defined, and
281 if (this->source_
!= FROM_OBJECT
)
284 // If the symbol is from a dynamic object, then the final value is
286 if (this->object()->is_dynamic())
289 // If the symbol is not undefined (it is defined or common), then
290 // the final value is known.
291 if (!this->is_undefined())
294 // If the symbol is undefined, then whether the final value is known
295 // depends on whether we are doing a static link. If we are doing a
296 // dynamic link, then the final value could be filled in at runtime.
297 // This could reasonably be the case for a weak undefined symbol.
298 return parameters
->doing_static_link();
301 // Return whether the symbol has an absolute value.
304 Symbol::value_is_absolute() const
306 switch (this->source_
)
309 return this->u_
.from_object
.shndx
== elfcpp::SHN_ABS
;
311 case IN_OUTPUT_SEGMENT
:
320 // Class Symbol_table.
322 Symbol_table::Symbol_table(unsigned int count
,
323 const Version_script_info
& version_script
)
324 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
325 forwarders_(), commons_(), forced_locals_(), warnings_(),
326 version_script_(version_script
)
328 namepool_
.reserve(count
);
331 Symbol_table::~Symbol_table()
335 // The hash function. The key values are Stringpool keys.
338 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key
& key
) const
340 return key
.first
^ key
.second
;
343 // The symbol table key equality function. This is called with
347 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
348 const Symbol_table_key
& k2
) const
350 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
353 // Make TO a symbol which forwards to FROM.
356 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
358 gold_assert(from
!= to
);
359 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
360 this->forwarders_
[from
] = to
;
361 from
->set_forwarder();
364 // Resolve the forwards from FROM, returning the real symbol.
367 Symbol_table::resolve_forwards(const Symbol
* from
) const
369 gold_assert(from
->is_forwarder());
370 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
371 this->forwarders_
.find(from
);
372 gold_assert(p
!= this->forwarders_
.end());
376 // Look up a symbol by name.
379 Symbol_table::lookup(const char* name
, const char* version
) const
381 Stringpool::Key name_key
;
382 name
= this->namepool_
.find(name
, &name_key
);
386 Stringpool::Key version_key
= 0;
389 version
= this->namepool_
.find(version
, &version_key
);
394 Symbol_table_key
key(name_key
, version_key
);
395 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
396 if (p
== this->table_
.end())
401 // Resolve a Symbol with another Symbol. This is only used in the
402 // unusual case where there are references to both an unversioned
403 // symbol and a symbol with a version, and we then discover that that
404 // version is the default version. Because this is unusual, we do
405 // this the slow way, by converting back to an ELF symbol.
407 template<int size
, bool big_endian
>
409 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
,
410 const char* version ACCEPT_SIZE_ENDIAN
)
412 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
413 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
414 // We don't bother to set the st_name field.
415 esym
.put_st_value(from
->value());
416 esym
.put_st_size(from
->symsize());
417 esym
.put_st_info(from
->binding(), from
->type());
418 esym
.put_st_other(from
->visibility(), from
->nonvis());
419 esym
.put_st_shndx(from
->shndx());
420 this->resolve(to
, esym
.sym(), esym
.sym(), from
->object(), version
);
427 // Record that a symbol is forced to be local by a version script.
430 Symbol_table::force_local(Symbol
* sym
)
432 if (!sym
->is_defined() && !sym
->is_common())
434 if (sym
->is_forced_local())
436 // We already got this one.
439 sym
->set_is_forced_local();
440 this->forced_locals_
.push_back(sym
);
443 // Add one symbol from OBJECT to the symbol table. NAME is symbol
444 // name and VERSION is the version; both are canonicalized. DEF is
445 // whether this is the default version.
447 // If DEF is true, then this is the definition of a default version of
448 // a symbol. That means that any lookup of NAME/NULL and any lookup
449 // of NAME/VERSION should always return the same symbol. This is
450 // obvious for references, but in particular we want to do this for
451 // definitions: overriding NAME/NULL should also override
452 // NAME/VERSION. If we don't do that, it would be very hard to
453 // override functions in a shared library which uses versioning.
455 // We implement this by simply making both entries in the hash table
456 // point to the same Symbol structure. That is easy enough if this is
457 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
458 // that we have seen both already, in which case they will both have
459 // independent entries in the symbol table. We can't simply change
460 // the symbol table entry, because we have pointers to the entries
461 // attached to the object files. So we mark the entry attached to the
462 // object file as a forwarder, and record it in the forwarders_ map.
463 // Note that entries in the hash table will never be marked as
466 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
467 // symbol exactly as it existed in the input file. SYM is usually
468 // that as well, but can be modified, for instance if we determine
469 // it's in a to-be-discarded section.
471 template<int size
, bool big_endian
>
473 Symbol_table::add_from_object(Object
* object
,
475 Stringpool::Key name_key
,
477 Stringpool::Key version_key
,
479 const elfcpp::Sym
<size
, big_endian
>& sym
,
480 const elfcpp::Sym
<size
, big_endian
>& orig_sym
)
482 Symbol
* const snull
= NULL
;
483 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
484 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
487 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
488 std::make_pair(this->table_
.end(), false);
491 const Stringpool::Key vnull_key
= 0;
492 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
497 // ins.first: an iterator, which is a pointer to a pair.
498 // ins.first->first: the key (a pair of name and version).
499 // ins.first->second: the value (Symbol*).
500 // ins.second: true if new entry was inserted, false if not.
502 Sized_symbol
<size
>* ret
;
507 // We already have an entry for NAME/VERSION.
508 ret
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (ins
.first
->second
510 gold_assert(ret
!= NULL
);
512 was_undefined
= ret
->is_undefined();
513 was_common
= ret
->is_common();
515 this->resolve(ret
, sym
, orig_sym
, object
, version
);
521 // This is the first time we have seen NAME/NULL. Make
522 // NAME/NULL point to NAME/VERSION.
523 insdef
.first
->second
= ret
;
525 else if (insdef
.first
->second
!= ret
526 && insdef
.first
->second
->is_undefined())
528 // This is the unfortunate case where we already have
529 // entries for both NAME/VERSION and NAME/NULL. Note
530 // that we don't want to combine them if the existing
531 // symbol is going to override the new one. FIXME: We
532 // currently just test is_undefined, but this may not do
533 // the right thing if the existing symbol is from a
534 // shared library and the new one is from a regular
537 const Sized_symbol
<size
>* sym2
;
538 sym2
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (
541 Symbol_table::resolve
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
542 ret
, sym2
, version
SELECT_SIZE_ENDIAN(size
, big_endian
));
543 this->make_forwarder(insdef
.first
->second
, ret
);
544 insdef
.first
->second
= ret
;
550 // This is the first time we have seen NAME/VERSION.
551 gold_assert(ins
.first
->second
== NULL
);
553 was_undefined
= false;
556 if (def
&& !insdef
.second
)
558 // We already have an entry for NAME/NULL. If we override
559 // it, then change it to NAME/VERSION.
560 ret
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (
563 this->resolve(ret
, sym
, orig_sym
, object
, version
);
564 ins
.first
->second
= ret
;
568 Sized_target
<size
, big_endian
>* target
=
569 object
->sized_target
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
570 SELECT_SIZE_ENDIAN_ONLY(size
, big_endian
));
571 if (!target
->has_make_symbol())
572 ret
= new Sized_symbol
<size
>();
575 ret
= target
->make_symbol();
578 // This means that we don't want a symbol table
581 this->table_
.erase(ins
.first
);
584 this->table_
.erase(insdef
.first
);
585 // Inserting insdef invalidated ins.
586 this->table_
.erase(std::make_pair(name_key
,
593 ret
->init(name
, version
, object
, sym
);
595 ins
.first
->second
= ret
;
598 // This is the first time we have seen NAME/NULL. Point
599 // it at the new entry for NAME/VERSION.
600 gold_assert(insdef
.second
);
601 insdef
.first
->second
= ret
;
606 // Record every time we see a new undefined symbol, to speed up
608 if (!was_undefined
&& ret
->is_undefined())
609 ++this->saw_undefined_
;
611 // Keep track of common symbols, to speed up common symbol
613 if (!was_common
&& ret
->is_common())
614 this->commons_
.push_back(ret
);
616 ret
->set_is_default(def
);
620 // Add all the symbols in a relocatable object to the hash table.
622 template<int size
, bool big_endian
>
624 Symbol_table::add_from_relobj(
625 Sized_relobj
<size
, big_endian
>* relobj
,
626 const unsigned char* syms
,
628 const char* sym_names
,
629 size_t sym_name_size
,
630 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
)
632 gold_assert(size
== relobj
->target()->get_size());
633 gold_assert(size
== parameters
->get_size());
635 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
637 const unsigned char* p
= syms
;
638 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
640 elfcpp::Sym
<size
, big_endian
> sym(p
);
641 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
643 unsigned int st_name
= psym
->get_st_name();
644 if (st_name
>= sym_name_size
)
646 relobj
->error(_("bad global symbol name offset %u at %zu"),
651 const char* name
= sym_names
+ st_name
;
653 // A symbol defined in a section which we are not including must
654 // be treated as an undefined symbol.
655 unsigned char symbuf
[sym_size
];
656 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
657 unsigned int st_shndx
= psym
->get_st_shndx();
658 if (st_shndx
!= elfcpp::SHN_UNDEF
659 && st_shndx
< elfcpp::SHN_LORESERVE
660 && !relobj
->is_section_included(st_shndx
))
662 memcpy(symbuf
, p
, sym_size
);
663 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
664 sw
.put_st_shndx(elfcpp::SHN_UNDEF
);
668 // In an object file, an '@' in the name separates the symbol
669 // name from the version name. If there are two '@' characters,
670 // this is the default version.
671 const char* ver
= strchr(name
, '@');
673 // DEF: is the version default? LOCAL: is the symbol forced local?
679 // The symbol name is of the form foo@VERSION or foo@@VERSION
680 namelen
= ver
- name
;
688 else if (!version_script_
.empty())
690 // The symbol name did not have a version, but
691 // the version script may assign a version anyway.
692 namelen
= strlen(name
);
694 // Check the global: entries from the version script.
695 const std::string
& version
=
696 version_script_
.get_symbol_version(name
);
697 if (!version
.empty())
698 ver
= version
.c_str();
699 // Check the local: entries from the version script
700 if (version_script_
.symbol_is_local(name
))
704 Sized_symbol
<size
>* res
;
707 Stringpool::Key name_key
;
708 name
= this->namepool_
.add(name
, true, &name_key
);
709 res
= this->add_from_object(relobj
, name
, name_key
, NULL
, 0,
712 this->force_local(res
);
716 Stringpool::Key name_key
;
717 name
= this->namepool_
.add_with_length(name
, namelen
, true,
719 Stringpool::Key ver_key
;
720 ver
= this->namepool_
.add(ver
, true, &ver_key
);
722 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
726 (*sympointers
)[i
] = res
;
730 // Add all the symbols in a dynamic object to the hash table.
732 template<int size
, bool big_endian
>
734 Symbol_table::add_from_dynobj(
735 Sized_dynobj
<size
, big_endian
>* dynobj
,
736 const unsigned char* syms
,
738 const char* sym_names
,
739 size_t sym_name_size
,
740 const unsigned char* versym
,
742 const std::vector
<const char*>* version_map
)
744 gold_assert(size
== dynobj
->target()->get_size());
745 gold_assert(size
== parameters
->get_size());
747 if (versym
!= NULL
&& versym_size
/ 2 < count
)
749 dynobj
->error(_("too few symbol versions"));
753 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
755 // We keep a list of all STT_OBJECT symbols, so that we can resolve
756 // weak aliases. This is necessary because if the dynamic object
757 // provides the same variable under two names, one of which is a
758 // weak definition, and the regular object refers to the weak
759 // definition, we have to put both the weak definition and the
760 // strong definition into the dynamic symbol table. Given a weak
761 // definition, the only way that we can find the corresponding
762 // strong definition, if any, is to search the symbol table.
763 std::vector
<Sized_symbol
<size
>*> object_symbols
;
765 const unsigned char* p
= syms
;
766 const unsigned char* vs
= versym
;
767 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
769 elfcpp::Sym
<size
, big_endian
> sym(p
);
771 // Ignore symbols with local binding or that have
772 // internal or hidden visibility.
773 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
774 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
775 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
778 unsigned int st_name
= sym
.get_st_name();
779 if (st_name
>= sym_name_size
)
781 dynobj
->error(_("bad symbol name offset %u at %zu"),
786 const char* name
= sym_names
+ st_name
;
788 Sized_symbol
<size
>* res
;
792 Stringpool::Key name_key
;
793 name
= this->namepool_
.add(name
, true, &name_key
);
794 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
799 // Read the version information.
801 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
803 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
804 v
&= elfcpp::VERSYM_VERSION
;
806 // The Sun documentation says that V can be VER_NDX_LOCAL,
807 // or VER_NDX_GLOBAL, or a version index. The meaning of
808 // VER_NDX_LOCAL is defined as "Symbol has local scope."
809 // The old GNU linker will happily generate VER_NDX_LOCAL
810 // for an undefined symbol. I don't know what the Sun
811 // linker will generate.
813 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
814 && sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
816 // This symbol should not be visible outside the object.
820 // At this point we are definitely going to add this symbol.
821 Stringpool::Key name_key
;
822 name
= this->namepool_
.add(name
, true, &name_key
);
824 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
825 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
827 // This symbol does not have a version.
828 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
833 if (v
>= version_map
->size())
835 dynobj
->error(_("versym for symbol %zu out of range: %u"),
840 const char* version
= (*version_map
)[v
];
843 dynobj
->error(_("versym for symbol %zu has no name: %u"),
848 Stringpool::Key version_key
;
849 version
= this->namepool_
.add(version
, true, &version_key
);
851 // If this is an absolute symbol, and the version name
852 // and symbol name are the same, then this is the
853 // version definition symbol. These symbols exist to
854 // support using -u to pull in particular versions. We
855 // do not want to record a version for them.
856 if (sym
.get_st_shndx() == elfcpp::SHN_ABS
857 && name_key
== version_key
)
858 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
862 const bool def
= (!hidden
863 && (sym
.get_st_shndx()
864 != elfcpp::SHN_UNDEF
));
865 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
866 version_key
, def
, sym
, sym
);
871 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
872 && sym
.get_st_type() == elfcpp::STT_OBJECT
)
873 object_symbols
.push_back(res
);
876 this->record_weak_aliases(&object_symbols
);
879 // This is used to sort weak aliases. We sort them first by section
880 // index, then by offset, then by weak ahead of strong.
883 class Weak_alias_sorter
886 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
891 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
892 const Sized_symbol
<size
>* s2
) const
894 if (s1
->shndx() != s2
->shndx())
895 return s1
->shndx() < s2
->shndx();
896 if (s1
->value() != s2
->value())
897 return s1
->value() < s2
->value();
898 if (s1
->binding() != s2
->binding())
900 if (s1
->binding() == elfcpp::STB_WEAK
)
902 if (s2
->binding() == elfcpp::STB_WEAK
)
905 return std::string(s1
->name()) < std::string(s2
->name());
908 // SYMBOLS is a list of object symbols from a dynamic object. Look
909 // for any weak aliases, and record them so that if we add the weak
910 // alias to the dynamic symbol table, we also add the corresponding
915 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
917 // Sort the vector by section index, then by offset, then by weak
919 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
921 // Walk through the vector. For each weak definition, record
923 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
928 if ((*p
)->binding() != elfcpp::STB_WEAK
)
931 // Build a circular list of weak aliases. Each symbol points to
932 // the next one in the circular list.
934 Sized_symbol
<size
>* from_sym
= *p
;
935 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
936 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
938 if ((*q
)->shndx() != from_sym
->shndx()
939 || (*q
)->value() != from_sym
->value())
942 this->weak_aliases_
[from_sym
] = *q
;
943 from_sym
->set_has_alias();
949 this->weak_aliases_
[from_sym
] = *p
;
950 from_sym
->set_has_alias();
957 // Create and return a specially defined symbol. If ONLY_IF_REF is
958 // true, then only create the symbol if there is a reference to it.
959 // If this does not return NULL, it sets *POLDSYM to the existing
960 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
962 template<int size
, bool big_endian
>
964 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
966 Sized_symbol
<size
>** poldsym
970 Sized_symbol
<size
>* sym
;
971 bool add_to_table
= false;
972 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
974 // If the caller didn't give us a version, see if we get one from
975 // the version script.
976 if (*pversion
== NULL
)
978 const std::string
& v(this->version_script_
.get_symbol_version(*pname
));
980 *pversion
= v
.c_str();
985 oldsym
= this->lookup(*pname
, *pversion
);
986 if (oldsym
== NULL
|| !oldsym
->is_undefined())
989 *pname
= oldsym
->name();
990 *pversion
= oldsym
->version();
994 // Canonicalize NAME and VERSION.
995 Stringpool::Key name_key
;
996 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
998 Stringpool::Key version_key
= 0;
999 if (*pversion
!= NULL
)
1000 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1002 Symbol
* const snull
= NULL
;
1003 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1004 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1010 // We already have a symbol table entry for NAME/VERSION.
1011 oldsym
= ins
.first
->second
;
1012 gold_assert(oldsym
!= NULL
);
1016 // We haven't seen this symbol before.
1017 gold_assert(ins
.first
->second
== NULL
);
1018 add_to_table
= true;
1019 add_loc
= ins
.first
;
1024 const Target
* target
= parameters
->target();
1025 if (!target
->has_make_symbol())
1026 sym
= new Sized_symbol
<size
>();
1029 gold_assert(target
->get_size() == size
);
1030 gold_assert(target
->is_big_endian() ? big_endian
: !big_endian
);
1031 typedef Sized_target
<size
, big_endian
> My_target
;
1032 const My_target
* sized_target
=
1033 static_cast<const My_target
*>(target
);
1034 sym
= sized_target
->make_symbol();
1040 add_loc
->second
= sym
;
1042 gold_assert(oldsym
!= NULL
);
1044 *poldsym
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (oldsym
1050 // Define a symbol based on an Output_data.
1053 Symbol_table::define_in_output_data(const char* name
,
1054 const char* version
,
1059 elfcpp::STB binding
,
1060 elfcpp::STV visibility
,
1061 unsigned char nonvis
,
1062 bool offset_is_from_end
,
1065 if (parameters
->get_size() == 32)
1067 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1068 return this->do_define_in_output_data
<32>(name
, version
, od
,
1069 value
, symsize
, type
, binding
,
1077 else if (parameters
->get_size() == 64)
1079 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1080 return this->do_define_in_output_data
<64>(name
, version
, od
,
1081 value
, symsize
, type
, binding
,
1093 // Define a symbol in an Output_data, sized version.
1097 Symbol_table::do_define_in_output_data(
1099 const char* version
,
1101 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1102 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1104 elfcpp::STB binding
,
1105 elfcpp::STV visibility
,
1106 unsigned char nonvis
,
1107 bool offset_is_from_end
,
1110 Sized_symbol
<size
>* sym
;
1111 Sized_symbol
<size
>* oldsym
;
1113 if (parameters
->is_big_endian())
1115 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1116 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, true) (
1117 &name
, &version
, only_if_ref
, &oldsym
1118 SELECT_SIZE_ENDIAN(size
, true));
1125 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1126 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, false) (
1127 &name
, &version
, only_if_ref
, &oldsym
1128 SELECT_SIZE_ENDIAN(size
, false));
1137 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1138 sym
->init(name
, od
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1139 offset_is_from_end
);
1143 if (binding
== elfcpp::STB_LOCAL
1144 || this->version_script_
.symbol_is_local(name
))
1145 this->force_local(sym
);
1149 if (Symbol_table::should_override_with_special(oldsym
))
1150 this->override_with_special(oldsym
, sym
);
1155 // Define a symbol based on an Output_segment.
1158 Symbol_table::define_in_output_segment(const char* name
,
1159 const char* version
, Output_segment
* os
,
1163 elfcpp::STB binding
,
1164 elfcpp::STV visibility
,
1165 unsigned char nonvis
,
1166 Symbol::Segment_offset_base offset_base
,
1169 if (parameters
->get_size() == 32)
1171 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1172 return this->do_define_in_output_segment
<32>(name
, version
, os
,
1173 value
, symsize
, type
,
1174 binding
, visibility
, nonvis
,
1175 offset_base
, only_if_ref
);
1180 else if (parameters
->get_size() == 64)
1182 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1183 return this->do_define_in_output_segment
<64>(name
, version
, os
,
1184 value
, symsize
, type
,
1185 binding
, visibility
, nonvis
,
1186 offset_base
, only_if_ref
);
1195 // Define a symbol in an Output_segment, sized version.
1199 Symbol_table::do_define_in_output_segment(
1201 const char* version
,
1203 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1204 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1206 elfcpp::STB binding
,
1207 elfcpp::STV visibility
,
1208 unsigned char nonvis
,
1209 Symbol::Segment_offset_base offset_base
,
1212 Sized_symbol
<size
>* sym
;
1213 Sized_symbol
<size
>* oldsym
;
1215 if (parameters
->is_big_endian())
1217 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1218 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, true) (
1219 &name
, &version
, only_if_ref
, &oldsym
1220 SELECT_SIZE_ENDIAN(size
, true));
1227 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1228 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, false) (
1229 &name
, &version
, only_if_ref
, &oldsym
1230 SELECT_SIZE_ENDIAN(size
, false));
1239 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1240 sym
->init(name
, os
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1245 if (binding
== elfcpp::STB_LOCAL
1246 || this->version_script_
.symbol_is_local(name
))
1247 this->force_local(sym
);
1251 if (Symbol_table::should_override_with_special(oldsym
))
1252 this->override_with_special(oldsym
, sym
);
1257 // Define a special symbol with a constant value. It is a multiple
1258 // definition error if this symbol is already defined.
1261 Symbol_table::define_as_constant(const char* name
,
1262 const char* version
,
1266 elfcpp::STB binding
,
1267 elfcpp::STV visibility
,
1268 unsigned char nonvis
,
1271 if (parameters
->get_size() == 32)
1273 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1274 return this->do_define_as_constant
<32>(name
, version
, value
,
1275 symsize
, type
, binding
,
1276 visibility
, nonvis
, only_if_ref
);
1281 else if (parameters
->get_size() == 64)
1283 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1284 return this->do_define_as_constant
<64>(name
, version
, value
,
1285 symsize
, type
, binding
,
1286 visibility
, nonvis
, only_if_ref
);
1295 // Define a symbol as a constant, sized version.
1299 Symbol_table::do_define_as_constant(
1301 const char* version
,
1302 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1303 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1305 elfcpp::STB binding
,
1306 elfcpp::STV visibility
,
1307 unsigned char nonvis
,
1310 Sized_symbol
<size
>* sym
;
1311 Sized_symbol
<size
>* oldsym
;
1313 if (parameters
->is_big_endian())
1315 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1316 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, true) (
1317 &name
, &version
, only_if_ref
, &oldsym
1318 SELECT_SIZE_ENDIAN(size
, true));
1325 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1326 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, false) (
1327 &name
, &version
, only_if_ref
, &oldsym
1328 SELECT_SIZE_ENDIAN(size
, false));
1337 gold_assert(version
== NULL
|| version
== name
|| oldsym
!= NULL
);
1338 sym
->init(name
, value
, symsize
, type
, binding
, visibility
, nonvis
);
1342 if (binding
== elfcpp::STB_LOCAL
1343 || this->version_script_
.symbol_is_local(name
))
1344 this->force_local(sym
);
1348 if (Symbol_table::should_override_with_special(oldsym
))
1349 this->override_with_special(oldsym
, sym
);
1354 // Define a set of symbols in output sections.
1357 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1358 const Define_symbol_in_section
* p
,
1361 for (int i
= 0; i
< count
; ++i
, ++p
)
1363 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1365 this->define_in_output_data(p
->name
, NULL
, os
, p
->value
,
1366 p
->size
, p
->type
, p
->binding
,
1367 p
->visibility
, p
->nonvis
,
1368 p
->offset_is_from_end
,
1369 only_if_ref
|| p
->only_if_ref
);
1371 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1372 p
->binding
, p
->visibility
, p
->nonvis
,
1373 only_if_ref
|| p
->only_if_ref
);
1377 // Define a set of symbols in output segments.
1380 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1381 const Define_symbol_in_segment
* p
,
1384 for (int i
= 0; i
< count
; ++i
, ++p
)
1386 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1387 p
->segment_flags_set
,
1388 p
->segment_flags_clear
);
1390 this->define_in_output_segment(p
->name
, NULL
, os
, p
->value
,
1391 p
->size
, p
->type
, p
->binding
,
1392 p
->visibility
, p
->nonvis
,
1394 only_if_ref
|| p
->only_if_ref
);
1396 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1397 p
->binding
, p
->visibility
, p
->nonvis
,
1398 only_if_ref
|| p
->only_if_ref
);
1402 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1403 // symbol should be defined--typically a .dyn.bss section. VALUE is
1404 // the offset within POSD.
1408 Symbol_table::define_with_copy_reloc(
1409 Sized_symbol
<size
>* csym
,
1411 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1413 gold_assert(csym
->is_from_dynobj());
1414 gold_assert(!csym
->is_copied_from_dynobj());
1415 Object
* object
= csym
->object();
1416 gold_assert(object
->is_dynamic());
1417 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1419 // Our copied variable has to override any variable in a shared
1421 elfcpp::STB binding
= csym
->binding();
1422 if (binding
== elfcpp::STB_WEAK
)
1423 binding
= elfcpp::STB_GLOBAL
;
1425 this->define_in_output_data(csym
->name(), csym
->version(),
1426 posd
, value
, csym
->symsize(),
1427 csym
->type(), binding
,
1428 csym
->visibility(), csym
->nonvis(),
1431 csym
->set_is_copied_from_dynobj();
1432 csym
->set_needs_dynsym_entry();
1434 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1436 // We have now defined all aliases, but we have not entered them all
1437 // in the copied_symbol_dynobjs_ map.
1438 if (csym
->has_alias())
1443 sym
= this->weak_aliases_
[sym
];
1446 gold_assert(sym
->output_data() == posd
);
1448 sym
->set_is_copied_from_dynobj();
1449 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1454 // SYM is defined using a COPY reloc. Return the dynamic object where
1455 // the original definition was found.
1458 Symbol_table::get_copy_source(const Symbol
* sym
) const
1460 gold_assert(sym
->is_copied_from_dynobj());
1461 Copied_symbol_dynobjs::const_iterator p
=
1462 this->copied_symbol_dynobjs_
.find(sym
);
1463 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1467 // Set the dynamic symbol indexes. INDEX is the index of the first
1468 // global dynamic symbol. Pointers to the symbols are stored into the
1469 // vector SYMS. The names are added to DYNPOOL. This returns an
1470 // updated dynamic symbol index.
1473 Symbol_table::set_dynsym_indexes(unsigned int index
,
1474 std::vector
<Symbol
*>* syms
,
1475 Stringpool
* dynpool
,
1478 for (Symbol_table_type::iterator p
= this->table_
.begin();
1479 p
!= this->table_
.end();
1482 Symbol
* sym
= p
->second
;
1484 // Note that SYM may already have a dynamic symbol index, since
1485 // some symbols appear more than once in the symbol table, with
1486 // and without a version.
1488 if (!sym
->should_add_dynsym_entry())
1489 sym
->set_dynsym_index(-1U);
1490 else if (!sym
->has_dynsym_index())
1492 sym
->set_dynsym_index(index
);
1494 syms
->push_back(sym
);
1495 dynpool
->add(sym
->name(), false, NULL
);
1497 // Record any version information.
1498 if (sym
->version() != NULL
)
1499 versions
->record_version(this, dynpool
, sym
);
1503 // Finish up the versions. In some cases this may add new dynamic
1505 index
= versions
->finalize(this, index
, syms
);
1510 // Set the final values for all the symbols. The index of the first
1511 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1512 // file offset OFF. Add their names to POOL. Return the new file
1513 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1516 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
1517 size_t dyncount
, Stringpool
* pool
,
1518 unsigned int *plocal_symcount
)
1522 gold_assert(*plocal_symcount
!= 0);
1523 this->first_global_index_
= *plocal_symcount
;
1525 this->dynamic_offset_
= dynoff
;
1526 this->first_dynamic_global_index_
= dyn_global_index
;
1527 this->dynamic_count_
= dyncount
;
1529 if (parameters
->get_size() == 32)
1531 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1532 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
1537 else if (parameters
->get_size() == 64)
1539 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1540 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
1548 // Now that we have the final symbol table, we can reliably note
1549 // which symbols should get warnings.
1550 this->warnings_
.note_warnings(this);
1555 // SYM is going into the symbol table at *PINDEX. Add the name to
1556 // POOL, update *PINDEX and *POFF.
1560 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
1561 unsigned int* pindex
, off_t
* poff
)
1563 sym
->set_symtab_index(*pindex
);
1564 pool
->add(sym
->name(), false, NULL
);
1566 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
1569 // Set the final value for all the symbols. This is called after
1570 // Layout::finalize, so all the output sections have their final
1575 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
1576 unsigned int* plocal_symcount
)
1578 off
= align_address(off
, size
>> 3);
1579 this->offset_
= off
;
1581 unsigned int index
= *plocal_symcount
;
1582 const unsigned int orig_index
= index
;
1584 // First do all the symbols which have been forced to be local, as
1585 // they must appear before all global symbols.
1586 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
1587 p
!= this->forced_locals_
.end();
1591 gold_assert(sym
->is_forced_local());
1592 if (this->sized_finalize_symbol
<size
>(sym
))
1594 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1599 // Now do all the remaining symbols.
1600 for (Symbol_table_type::iterator p
= this->table_
.begin();
1601 p
!= this->table_
.end();
1604 Symbol
* sym
= p
->second
;
1605 if (this->sized_finalize_symbol
<size
>(sym
))
1606 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1609 this->output_count_
= index
- orig_index
;
1614 // Finalize the symbol SYM. This returns true if the symbol should be
1615 // added to the symbol table, false otherwise.
1619 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
1621 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
1623 // The default version of a symbol may appear twice in the symbol
1624 // table. We only need to finalize it once.
1625 if (sym
->has_symtab_index())
1630 gold_assert(!sym
->has_symtab_index());
1631 sym
->set_symtab_index(-1U);
1632 gold_assert(sym
->dynsym_index() == -1U);
1636 typename Sized_symbol
<size
>::Value_type value
;
1638 switch (sym
->source())
1640 case Symbol::FROM_OBJECT
:
1642 unsigned int shndx
= sym
->shndx();
1644 // FIXME: We need some target specific support here.
1645 if (shndx
>= elfcpp::SHN_LORESERVE
1646 && shndx
!= elfcpp::SHN_ABS
)
1648 gold_error(_("%s: unsupported symbol section 0x%x"),
1649 sym
->demangled_name().c_str(), shndx
);
1650 shndx
= elfcpp::SHN_UNDEF
;
1653 Object
* symobj
= sym
->object();
1654 if (symobj
->is_dynamic())
1657 shndx
= elfcpp::SHN_UNDEF
;
1659 else if (shndx
== elfcpp::SHN_UNDEF
)
1661 else if (shndx
== elfcpp::SHN_ABS
)
1662 value
= sym
->value();
1665 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1666 section_offset_type secoff
;
1667 Output_section
* os
= relobj
->output_section(shndx
, &secoff
);
1671 sym
->set_symtab_index(-1U);
1672 gold_assert(sym
->dynsym_index() == -1U);
1676 if (sym
->type() == elfcpp::STT_TLS
)
1677 value
= sym
->value() + os
->tls_offset() + secoff
;
1679 value
= sym
->value() + os
->address() + secoff
;
1684 case Symbol::IN_OUTPUT_DATA
:
1686 Output_data
* od
= sym
->output_data();
1687 value
= sym
->value() + od
->address();
1688 if (sym
->offset_is_from_end())
1689 value
+= od
->data_size();
1693 case Symbol::IN_OUTPUT_SEGMENT
:
1695 Output_segment
* os
= sym
->output_segment();
1696 value
= sym
->value() + os
->vaddr();
1697 switch (sym
->offset_base())
1699 case Symbol::SEGMENT_START
:
1701 case Symbol::SEGMENT_END
:
1702 value
+= os
->memsz();
1704 case Symbol::SEGMENT_BSS
:
1705 value
+= os
->filesz();
1713 case Symbol::CONSTANT
:
1714 value
= sym
->value();
1721 sym
->set_value(value
);
1723 if (parameters
->strip_all())
1725 sym
->set_symtab_index(-1U);
1732 // Write out the global symbols.
1735 Symbol_table::write_globals(const Input_objects
* input_objects
,
1736 const Stringpool
* sympool
,
1737 const Stringpool
* dynpool
, Output_file
* of
) const
1739 if (parameters
->get_size() == 32)
1741 if (parameters
->is_big_endian())
1743 #ifdef HAVE_TARGET_32_BIG
1744 this->sized_write_globals
<32, true>(input_objects
, sympool
,
1752 #ifdef HAVE_TARGET_32_LITTLE
1753 this->sized_write_globals
<32, false>(input_objects
, sympool
,
1760 else if (parameters
->get_size() == 64)
1762 if (parameters
->is_big_endian())
1764 #ifdef HAVE_TARGET_64_BIG
1765 this->sized_write_globals
<64, true>(input_objects
, sympool
,
1773 #ifdef HAVE_TARGET_64_LITTLE
1774 this->sized_write_globals
<64, false>(input_objects
, sympool
,
1785 // Write out the global symbols.
1787 template<int size
, bool big_endian
>
1789 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
1790 const Stringpool
* sympool
,
1791 const Stringpool
* dynpool
,
1792 Output_file
* of
) const
1794 const Target
* const target
= input_objects
->target();
1796 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1798 const unsigned int output_count
= this->output_count_
;
1799 const section_size_type oview_size
= output_count
* sym_size
;
1800 const unsigned int first_global_index
= this->first_global_index_
;
1801 unsigned char* const psyms
= of
->get_output_view(this->offset_
, oview_size
);
1803 const unsigned int dynamic_count
= this->dynamic_count_
;
1804 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
1805 const unsigned int first_dynamic_global_index
=
1806 this->first_dynamic_global_index_
;
1807 unsigned char* dynamic_view
;
1808 if (this->dynamic_offset_
== 0)
1809 dynamic_view
= NULL
;
1811 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
1813 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1814 p
!= this->table_
.end();
1817 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1819 // Possibly warn about unresolved symbols in shared libraries.
1820 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
1822 unsigned int sym_index
= sym
->symtab_index();
1823 unsigned int dynsym_index
;
1824 if (dynamic_view
== NULL
)
1827 dynsym_index
= sym
->dynsym_index();
1829 if (sym_index
== -1U && dynsym_index
== -1U)
1831 // This symbol is not included in the output file.
1836 typename
elfcpp::Elf_types
<32>::Elf_Addr value
= sym
->value();
1837 switch (sym
->source())
1839 case Symbol::FROM_OBJECT
:
1841 unsigned int in_shndx
= sym
->shndx();
1843 // FIXME: We need some target specific support here.
1844 if (in_shndx
>= elfcpp::SHN_LORESERVE
1845 && in_shndx
!= elfcpp::SHN_ABS
)
1847 gold_error(_("%s: unsupported symbol section 0x%x"),
1848 sym
->demangled_name().c_str(), in_shndx
);
1853 Object
* symobj
= sym
->object();
1854 if (symobj
->is_dynamic())
1856 if (sym
->needs_dynsym_value())
1857 value
= target
->dynsym_value(sym
);
1858 shndx
= elfcpp::SHN_UNDEF
;
1860 else if (in_shndx
== elfcpp::SHN_UNDEF
1861 || in_shndx
== elfcpp::SHN_ABS
)
1865 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1866 section_offset_type secoff
;
1867 Output_section
* os
= relobj
->output_section(in_shndx
,
1869 gold_assert(os
!= NULL
);
1870 shndx
= os
->out_shndx();
1876 case Symbol::IN_OUTPUT_DATA
:
1877 shndx
= sym
->output_data()->out_shndx();
1880 case Symbol::IN_OUTPUT_SEGMENT
:
1881 shndx
= elfcpp::SHN_ABS
;
1884 case Symbol::CONSTANT
:
1885 shndx
= elfcpp::SHN_ABS
;
1892 if (sym_index
!= -1U)
1894 sym_index
-= first_global_index
;
1895 gold_assert(sym_index
< output_count
);
1896 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
1897 this->sized_write_symbol
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
1898 sym
, sym
->value(), shndx
, sympool
, ps
1899 SELECT_SIZE_ENDIAN(size
, big_endian
));
1902 if (dynsym_index
!= -1U)
1904 dynsym_index
-= first_dynamic_global_index
;
1905 gold_assert(dynsym_index
< dynamic_count
);
1906 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
1907 this->sized_write_symbol
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
1908 sym
, value
, shndx
, dynpool
, pd
1909 SELECT_SIZE_ENDIAN(size
, big_endian
));
1913 of
->write_output_view(this->offset_
, oview_size
, psyms
);
1914 if (dynamic_view
!= NULL
)
1915 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
1918 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1919 // strtab holding the name.
1921 template<int size
, bool big_endian
>
1923 Symbol_table::sized_write_symbol(
1924 Sized_symbol
<size
>* sym
,
1925 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1927 const Stringpool
* pool
,
1929 ACCEPT_SIZE_ENDIAN
) const
1931 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
1932 osym
.put_st_name(pool
->get_offset(sym
->name()));
1933 osym
.put_st_value(value
);
1934 osym
.put_st_size(sym
->symsize());
1935 // A version script may have overridden the default binding.
1936 if (sym
->is_forced_local())
1937 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, sym
->type()));
1939 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
1940 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
1941 osym
.put_st_shndx(shndx
);
1944 // Check for unresolved symbols in shared libraries. This is
1945 // controlled by the --allow-shlib-undefined option.
1947 // We only warn about libraries for which we have seen all the
1948 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
1949 // which were not seen in this link. If we didn't see a DT_NEEDED
1950 // entry, we aren't going to be able to reliably report whether the
1951 // symbol is undefined.
1953 // We also don't warn about libraries found in the system library
1954 // directory (the directory were we find libc.so); we assume that
1955 // those libraries are OK. This heuristic avoids problems in
1956 // GNU/Linux, in which -ldl can have undefined references satisfied by
1960 Symbol_table::warn_about_undefined_dynobj_symbol(
1961 const Input_objects
* input_objects
,
1964 if (sym
->source() == Symbol::FROM_OBJECT
1965 && sym
->object()->is_dynamic()
1966 && sym
->shndx() == elfcpp::SHN_UNDEF
1967 && sym
->binding() != elfcpp::STB_WEAK
1968 && !parameters
->allow_shlib_undefined()
1969 && !input_objects
->target()->is_defined_by_abi(sym
)
1970 && !input_objects
->found_in_system_library_directory(sym
->object()))
1972 // A very ugly cast.
1973 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
1974 if (!dynobj
->has_unknown_needed_entries())
1975 gold_error(_("%s: undefined reference to '%s'"),
1976 sym
->object()->name().c_str(),
1977 sym
->demangled_name().c_str());
1981 // Write out a section symbol. Return the update offset.
1984 Symbol_table::write_section_symbol(const Output_section
*os
,
1988 if (parameters
->get_size() == 32)
1990 if (parameters
->is_big_endian())
1992 #ifdef HAVE_TARGET_32_BIG
1993 this->sized_write_section_symbol
<32, true>(os
, of
, offset
);
2000 #ifdef HAVE_TARGET_32_LITTLE
2001 this->sized_write_section_symbol
<32, false>(os
, of
, offset
);
2007 else if (parameters
->get_size() == 64)
2009 if (parameters
->is_big_endian())
2011 #ifdef HAVE_TARGET_64_BIG
2012 this->sized_write_section_symbol
<64, true>(os
, of
, offset
);
2019 #ifdef HAVE_TARGET_64_LITTLE
2020 this->sized_write_section_symbol
<64, false>(os
, of
, offset
);
2030 // Write out a section symbol, specialized for size and endianness.
2032 template<int size
, bool big_endian
>
2034 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
2038 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2040 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
2042 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
2043 osym
.put_st_name(0);
2044 osym
.put_st_value(os
->address());
2045 osym
.put_st_size(0);
2046 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
2047 elfcpp::STT_SECTION
));
2048 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
2049 osym
.put_st_shndx(os
->out_shndx());
2051 of
->write_output_view(offset
, sym_size
, pov
);
2054 // Print statistical information to stderr. This is used for --stats.
2057 Symbol_table::print_stats() const
2059 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2060 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2061 program_name
, this->table_
.size(), this->table_
.bucket_count());
2063 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
2064 program_name
, this->table_
.size());
2066 this->namepool_
.print_stats("symbol table stringpool");
2069 // We check for ODR violations by looking for symbols with the same
2070 // name for which the debugging information reports that they were
2071 // defined in different source locations. When comparing the source
2072 // location, we consider instances with the same base filename and
2073 // line number to be the same. This is because different object
2074 // files/shared libraries can include the same header file using
2075 // different paths, and we don't want to report an ODR violation in
2078 // This struct is used to compare line information, as returned by
2079 // Dwarf_line_info::one_addr2line. It implements a < comparison
2080 // operator used with std::set.
2082 struct Odr_violation_compare
2085 operator()(const std::string
& s1
, const std::string
& s2
) const
2087 std::string::size_type pos1
= s1
.rfind('/');
2088 std::string::size_type pos2
= s2
.rfind('/');
2089 if (pos1
== std::string::npos
2090 || pos2
== std::string::npos
)
2092 return s1
.compare(pos1
, std::string::npos
,
2093 s2
, pos2
, std::string::npos
) < 0;
2097 // Check candidate_odr_violations_ to find symbols with the same name
2098 // but apparently different definitions (different source-file/line-no).
2101 Symbol_table::detect_odr_violations(const Task
* task
,
2102 const char* output_file_name
) const
2104 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
2105 it
!= candidate_odr_violations_
.end();
2108 const char* symbol_name
= it
->first
;
2109 // We use a sorted set so the output is deterministic.
2110 std::set
<std::string
, Odr_violation_compare
> line_nums
;
2112 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
2113 locs
= it
->second
.begin();
2114 locs
!= it
->second
.end();
2117 // We need to lock the object in order to read it. This
2118 // means that we have to run in a singleton Task. If we
2119 // want to run this in a general Task for better
2120 // performance, we will need one Task for object, plus
2121 // appropriate locking to ensure that we don't conflict with
2122 // other uses of the object.
2123 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2124 std::string lineno
= Dwarf_line_info::one_addr2line(
2125 locs
->object
, locs
->shndx
, locs
->offset
);
2126 if (!lineno
.empty())
2127 line_nums
.insert(lineno
);
2130 if (line_nums
.size() > 1)
2132 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2133 "places (possible ODR violation):"),
2134 output_file_name
, demangle(symbol_name
).c_str());
2135 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2136 it2
!= line_nums
.end();
2138 fprintf(stderr
, " %s\n", it2
->c_str());
2143 // Warnings functions.
2145 // Add a new warning.
2148 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2149 const std::string
& warning
)
2151 name
= symtab
->canonicalize_name(name
);
2152 this->warnings_
[name
].set(obj
, warning
);
2155 // Look through the warnings and mark the symbols for which we should
2156 // warn. This is called during Layout::finalize when we know the
2157 // sources for all the symbols.
2160 Warnings::note_warnings(Symbol_table
* symtab
)
2162 for (Warning_table::iterator p
= this->warnings_
.begin();
2163 p
!= this->warnings_
.end();
2166 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2168 && sym
->source() == Symbol::FROM_OBJECT
2169 && sym
->object() == p
->second
.object
)
2170 sym
->set_has_warning();
2174 // Issue a warning. This is called when we see a relocation against a
2175 // symbol for which has a warning.
2177 template<int size
, bool big_endian
>
2179 Warnings::issue_warning(const Symbol
* sym
,
2180 const Relocate_info
<size
, big_endian
>* relinfo
,
2181 size_t relnum
, off_t reloffset
) const
2183 gold_assert(sym
->has_warning());
2184 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2185 gold_assert(p
!= this->warnings_
.end());
2186 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2187 "%s", p
->second
.text
.c_str());
2190 // Instantiate the templates we need. We could use the configure
2191 // script to restrict this to only the ones needed for implemented
2194 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2197 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2200 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2203 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2206 #ifdef HAVE_TARGET_32_LITTLE
2209 Symbol_table::add_from_relobj
<32, false>(
2210 Sized_relobj
<32, false>* relobj
,
2211 const unsigned char* syms
,
2213 const char* sym_names
,
2214 size_t sym_name_size
,
2215 Sized_relobj
<32, true>::Symbols
* sympointers
);
2218 #ifdef HAVE_TARGET_32_BIG
2221 Symbol_table::add_from_relobj
<32, true>(
2222 Sized_relobj
<32, true>* relobj
,
2223 const unsigned char* syms
,
2225 const char* sym_names
,
2226 size_t sym_name_size
,
2227 Sized_relobj
<32, false>::Symbols
* sympointers
);
2230 #ifdef HAVE_TARGET_64_LITTLE
2233 Symbol_table::add_from_relobj
<64, false>(
2234 Sized_relobj
<64, false>* relobj
,
2235 const unsigned char* syms
,
2237 const char* sym_names
,
2238 size_t sym_name_size
,
2239 Sized_relobj
<64, true>::Symbols
* sympointers
);
2242 #ifdef HAVE_TARGET_64_BIG
2245 Symbol_table::add_from_relobj
<64, true>(
2246 Sized_relobj
<64, true>* relobj
,
2247 const unsigned char* syms
,
2249 const char* sym_names
,
2250 size_t sym_name_size
,
2251 Sized_relobj
<64, false>::Symbols
* sympointers
);
2254 #ifdef HAVE_TARGET_32_LITTLE
2257 Symbol_table::add_from_dynobj
<32, false>(
2258 Sized_dynobj
<32, false>* dynobj
,
2259 const unsigned char* syms
,
2261 const char* sym_names
,
2262 size_t sym_name_size
,
2263 const unsigned char* versym
,
2265 const std::vector
<const char*>* version_map
);
2268 #ifdef HAVE_TARGET_32_BIG
2271 Symbol_table::add_from_dynobj
<32, true>(
2272 Sized_dynobj
<32, true>* dynobj
,
2273 const unsigned char* syms
,
2275 const char* sym_names
,
2276 size_t sym_name_size
,
2277 const unsigned char* versym
,
2279 const std::vector
<const char*>* version_map
);
2282 #ifdef HAVE_TARGET_64_LITTLE
2285 Symbol_table::add_from_dynobj
<64, false>(
2286 Sized_dynobj
<64, false>* dynobj
,
2287 const unsigned char* syms
,
2289 const char* sym_names
,
2290 size_t sym_name_size
,
2291 const unsigned char* versym
,
2293 const std::vector
<const char*>* version_map
);
2296 #ifdef HAVE_TARGET_64_BIG
2299 Symbol_table::add_from_dynobj
<64, true>(
2300 Sized_dynobj
<64, true>* dynobj
,
2301 const unsigned char* syms
,
2303 const char* sym_names
,
2304 size_t sym_name_size
,
2305 const unsigned char* versym
,
2307 const std::vector
<const char*>* version_map
);
2310 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2313 Symbol_table::define_with_copy_reloc
<32>(
2314 Sized_symbol
<32>* sym
,
2316 elfcpp::Elf_types
<32>::Elf_Addr value
);
2319 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2322 Symbol_table::define_with_copy_reloc
<64>(
2323 Sized_symbol
<64>* sym
,
2325 elfcpp::Elf_types
<64>::Elf_Addr value
);
2328 #ifdef HAVE_TARGET_32_LITTLE
2331 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
2332 const Relocate_info
<32, false>* relinfo
,
2333 size_t relnum
, off_t reloffset
) const;
2336 #ifdef HAVE_TARGET_32_BIG
2339 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
2340 const Relocate_info
<32, true>* relinfo
,
2341 size_t relnum
, off_t reloffset
) const;
2344 #ifdef HAVE_TARGET_64_LITTLE
2347 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
2348 const Relocate_info
<64, false>* relinfo
,
2349 size_t relnum
, off_t reloffset
) const;
2352 #ifdef HAVE_TARGET_64_BIG
2355 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
2356 const Relocate_info
<64, true>* relinfo
,
2357 size_t relnum
, off_t reloffset
) const;
2360 } // End namespace gold.