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;
75 // Return the demangled version of the symbol's name, but only
76 // if the --demangle flag was set.
79 demangle(const char* name
)
81 if (!parameters
->demangle())
84 // cplus_demangle allocates memory for the result it returns,
85 // and returns NULL if the name is already demangled.
86 char* demangled_name
= cplus_demangle(name
, DMGL_ANSI
| DMGL_PARAMS
);
87 if (demangled_name
== NULL
)
90 std::string
retval(demangled_name
);
96 Symbol::demangled_name() const
98 return demangle(this->name());
101 // Initialize the fields in the base class Symbol for SYM in OBJECT.
103 template<int size
, bool big_endian
>
105 Symbol::init_base(const char* name
, const char* version
, Object
* object
,
106 const elfcpp::Sym
<size
, big_endian
>& sym
)
108 this->init_fields(name
, version
, sym
.get_st_type(), sym
.get_st_bind(),
109 sym
.get_st_visibility(), sym
.get_st_nonvis());
110 this->u_
.from_object
.object
= object
;
111 // FIXME: Handle SHN_XINDEX.
112 this->u_
.from_object
.shndx
= sym
.get_st_shndx();
113 this->source_
= FROM_OBJECT
;
114 this->in_reg_
= !object
->is_dynamic();
115 this->in_dyn_
= object
->is_dynamic();
118 // Initialize the fields in the base class Symbol for a symbol defined
119 // in an Output_data.
122 Symbol::init_base(const char* name
, Output_data
* od
, elfcpp::STT type
,
123 elfcpp::STB binding
, elfcpp::STV visibility
,
124 unsigned char nonvis
, bool offset_is_from_end
)
126 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
127 this->u_
.in_output_data
.output_data
= od
;
128 this->u_
.in_output_data
.offset_is_from_end
= offset_is_from_end
;
129 this->source_
= IN_OUTPUT_DATA
;
130 this->in_reg_
= true;
133 // Initialize the fields in the base class Symbol for a symbol defined
134 // in an Output_segment.
137 Symbol::init_base(const char* name
, Output_segment
* os
, elfcpp::STT type
,
138 elfcpp::STB binding
, elfcpp::STV visibility
,
139 unsigned char nonvis
, Segment_offset_base offset_base
)
141 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
142 this->u_
.in_output_segment
.output_segment
= os
;
143 this->u_
.in_output_segment
.offset_base
= offset_base
;
144 this->source_
= IN_OUTPUT_SEGMENT
;
145 this->in_reg_
= true;
148 // Initialize the fields in the base class Symbol for a symbol defined
152 Symbol::init_base(const char* name
, elfcpp::STT type
,
153 elfcpp::STB binding
, elfcpp::STV visibility
,
154 unsigned char nonvis
)
156 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
157 this->source_
= CONSTANT
;
158 this->in_reg_
= true;
161 // Allocate a common symbol in the base.
164 Symbol::allocate_base_common(Output_data
* od
)
166 gold_assert(this->is_common());
167 this->source_
= IN_OUTPUT_DATA
;
168 this->u_
.in_output_data
.output_data
= od
;
169 this->u_
.in_output_data
.offset_is_from_end
= false;
172 // Initialize the fields in Sized_symbol for SYM in OBJECT.
175 template<bool big_endian
>
177 Sized_symbol
<size
>::init(const char* name
, const char* version
, Object
* object
,
178 const elfcpp::Sym
<size
, big_endian
>& sym
)
180 this->init_base(name
, version
, object
, sym
);
181 this->value_
= sym
.get_st_value();
182 this->symsize_
= sym
.get_st_size();
185 // Initialize the fields in Sized_symbol for a symbol defined in an
190 Sized_symbol
<size
>::init(const char* name
, Output_data
* od
,
191 Value_type value
, Size_type symsize
,
192 elfcpp::STT type
, elfcpp::STB binding
,
193 elfcpp::STV visibility
, unsigned char nonvis
,
194 bool offset_is_from_end
)
196 this->init_base(name
, od
, type
, binding
, visibility
, nonvis
,
198 this->value_
= value
;
199 this->symsize_
= symsize
;
202 // Initialize the fields in Sized_symbol for a symbol defined in an
207 Sized_symbol
<size
>::init(const char* name
, Output_segment
* os
,
208 Value_type value
, Size_type symsize
,
209 elfcpp::STT type
, elfcpp::STB binding
,
210 elfcpp::STV visibility
, unsigned char nonvis
,
211 Segment_offset_base offset_base
)
213 this->init_base(name
, os
, type
, binding
, visibility
, nonvis
, offset_base
);
214 this->value_
= value
;
215 this->symsize_
= symsize
;
218 // Initialize the fields in Sized_symbol for a symbol defined as a
223 Sized_symbol
<size
>::init(const char* name
, Value_type value
, Size_type symsize
,
224 elfcpp::STT type
, elfcpp::STB binding
,
225 elfcpp::STV visibility
, unsigned char nonvis
)
227 this->init_base(name
, type
, binding
, visibility
, nonvis
);
228 this->value_
= value
;
229 this->symsize_
= symsize
;
232 // Allocate a common symbol.
236 Sized_symbol
<size
>::allocate_common(Output_data
* od
, Value_type value
)
238 this->allocate_base_common(od
);
239 this->value_
= value
;
242 // Return true if this symbol should be added to the dynamic symbol
246 Symbol::should_add_dynsym_entry() const
248 // If the symbol is used by a dynamic relocation, we need to add it.
249 if (this->needs_dynsym_entry())
252 // If exporting all symbols or building a shared library,
253 // and the symbol is defined in a regular object and is
254 // externally visible, we need to add it.
255 if ((parameters
->export_dynamic() || parameters
->output_is_shared())
256 && !this->is_from_dynobj()
257 && this->is_externally_visible())
263 // Return true if the final value of this symbol is known at link
267 Symbol::final_value_is_known() const
269 // If we are not generating an executable, then no final values are
270 // known, since they will change at runtime.
271 if (!parameters
->output_is_executable())
274 // If the symbol is not from an object file, then it is defined, and
276 if (this->source_
!= FROM_OBJECT
)
279 // If the symbol is from a dynamic object, then the final value is
281 if (this->object()->is_dynamic())
284 // If the symbol is not undefined (it is defined or common), then
285 // the final value is known.
286 if (!this->is_undefined())
289 // If the symbol is undefined, then whether the final value is known
290 // depends on whether we are doing a static link. If we are doing a
291 // dynamic link, then the final value could be filled in at runtime.
292 // This could reasonably be the case for a weak undefined symbol.
293 return parameters
->doing_static_link();
296 // Class Symbol_table.
298 Symbol_table::Symbol_table(unsigned int count
,
299 const Version_script_info
& version_script
)
300 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
301 forwarders_(), commons_(), warnings_(), version_script_(version_script
)
303 namepool_
.reserve(count
);
306 Symbol_table::~Symbol_table()
310 // The hash function. The key values are Stringpool keys.
313 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key
& key
) const
315 return key
.first
^ key
.second
;
318 // The symbol table key equality function. This is called with
322 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
323 const Symbol_table_key
& k2
) const
325 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
328 // Make TO a symbol which forwards to FROM.
331 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
333 gold_assert(from
!= to
);
334 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
335 this->forwarders_
[from
] = to
;
336 from
->set_forwarder();
339 // Resolve the forwards from FROM, returning the real symbol.
342 Symbol_table::resolve_forwards(const Symbol
* from
) const
344 gold_assert(from
->is_forwarder());
345 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
346 this->forwarders_
.find(from
);
347 gold_assert(p
!= this->forwarders_
.end());
351 // Look up a symbol by name.
354 Symbol_table::lookup(const char* name
, const char* version
) const
356 Stringpool::Key name_key
;
357 name
= this->namepool_
.find(name
, &name_key
);
361 Stringpool::Key version_key
= 0;
364 version
= this->namepool_
.find(version
, &version_key
);
369 Symbol_table_key
key(name_key
, version_key
);
370 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
371 if (p
== this->table_
.end())
376 // Resolve a Symbol with another Symbol. This is only used in the
377 // unusual case where there are references to both an unversioned
378 // symbol and a symbol with a version, and we then discover that that
379 // version is the default version. Because this is unusual, we do
380 // this the slow way, by converting back to an ELF symbol.
382 template<int size
, bool big_endian
>
384 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
,
385 const char* version ACCEPT_SIZE_ENDIAN
)
387 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
388 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
389 // We don't bother to set the st_name field.
390 esym
.put_st_value(from
->value());
391 esym
.put_st_size(from
->symsize());
392 esym
.put_st_info(from
->binding(), from
->type());
393 esym
.put_st_other(from
->visibility(), from
->nonvis());
394 esym
.put_st_shndx(from
->shndx());
395 this->resolve(to
, esym
.sym(), esym
.sym(), from
->object(), version
);
402 // Add one symbol from OBJECT to the symbol table. NAME is symbol
403 // name and VERSION is the version; both are canonicalized. DEF is
404 // whether this is the default version.
406 // If DEF is true, then this is the definition of a default version of
407 // a symbol. That means that any lookup of NAME/NULL and any lookup
408 // of NAME/VERSION should always return the same symbol. This is
409 // obvious for references, but in particular we want to do this for
410 // definitions: overriding NAME/NULL should also override
411 // NAME/VERSION. If we don't do that, it would be very hard to
412 // override functions in a shared library which uses versioning.
414 // We implement this by simply making both entries in the hash table
415 // point to the same Symbol structure. That is easy enough if this is
416 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
417 // that we have seen both already, in which case they will both have
418 // independent entries in the symbol table. We can't simply change
419 // the symbol table entry, because we have pointers to the entries
420 // attached to the object files. So we mark the entry attached to the
421 // object file as a forwarder, and record it in the forwarders_ map.
422 // Note that entries in the hash table will never be marked as
425 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
426 // symbol exactly as it existed in the input file. SYM is usually
427 // that as well, but can be modified, for instance if we determine
428 // it's in a to-be-discarded section.
430 template<int size
, bool big_endian
>
432 Symbol_table::add_from_object(Object
* object
,
434 Stringpool::Key name_key
,
436 Stringpool::Key version_key
,
438 const elfcpp::Sym
<size
, big_endian
>& sym
,
439 const elfcpp::Sym
<size
, big_endian
>& orig_sym
)
441 Symbol
* const snull
= NULL
;
442 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
443 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
446 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
447 std::make_pair(this->table_
.end(), false);
450 const Stringpool::Key vnull_key
= 0;
451 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
456 // ins.first: an iterator, which is a pointer to a pair.
457 // ins.first->first: the key (a pair of name and version).
458 // ins.first->second: the value (Symbol*).
459 // ins.second: true if new entry was inserted, false if not.
461 Sized_symbol
<size
>* ret
;
466 // We already have an entry for NAME/VERSION.
467 ret
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (ins
.first
->second
469 gold_assert(ret
!= NULL
);
471 was_undefined
= ret
->is_undefined();
472 was_common
= ret
->is_common();
474 this->resolve(ret
, sym
, orig_sym
, object
, version
);
480 // This is the first time we have seen NAME/NULL. Make
481 // NAME/NULL point to NAME/VERSION.
482 insdef
.first
->second
= ret
;
484 else if (insdef
.first
->second
!= ret
485 && insdef
.first
->second
->is_undefined())
487 // This is the unfortunate case where we already have
488 // entries for both NAME/VERSION and NAME/NULL. Note
489 // that we don't want to combine them if the existing
490 // symbol is going to override the new one. FIXME: We
491 // currently just test is_undefined, but this may not do
492 // the right thing if the existing symbol is from a
493 // shared library and the new one is from a regular
496 const Sized_symbol
<size
>* sym2
;
497 sym2
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (
500 Symbol_table::resolve
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
501 ret
, sym2
, version
SELECT_SIZE_ENDIAN(size
, big_endian
));
502 this->make_forwarder(insdef
.first
->second
, ret
);
503 insdef
.first
->second
= ret
;
509 // This is the first time we have seen NAME/VERSION.
510 gold_assert(ins
.first
->second
== NULL
);
512 was_undefined
= false;
515 if (def
&& !insdef
.second
)
517 // We already have an entry for NAME/NULL. If we override
518 // it, then change it to NAME/VERSION.
519 ret
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (
522 this->resolve(ret
, sym
, orig_sym
, object
, version
);
523 ins
.first
->second
= ret
;
527 Sized_target
<size
, big_endian
>* target
=
528 object
->sized_target
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
529 SELECT_SIZE_ENDIAN_ONLY(size
, big_endian
));
530 if (!target
->has_make_symbol())
531 ret
= new Sized_symbol
<size
>();
534 ret
= target
->make_symbol();
537 // This means that we don't want a symbol table
540 this->table_
.erase(ins
.first
);
543 this->table_
.erase(insdef
.first
);
544 // Inserting insdef invalidated ins.
545 this->table_
.erase(std::make_pair(name_key
,
552 ret
->init(name
, version
, object
, sym
);
554 ins
.first
->second
= ret
;
557 // This is the first time we have seen NAME/NULL. Point
558 // it at the new entry for NAME/VERSION.
559 gold_assert(insdef
.second
);
560 insdef
.first
->second
= ret
;
565 // Record every time we see a new undefined symbol, to speed up
567 if (!was_undefined
&& ret
->is_undefined())
568 ++this->saw_undefined_
;
570 // Keep track of common symbols, to speed up common symbol
572 if (!was_common
&& ret
->is_common())
573 this->commons_
.push_back(ret
);
575 ret
->set_is_default(def
);
579 // Add all the symbols in a relocatable object to the hash table.
581 template<int size
, bool big_endian
>
583 Symbol_table::add_from_relobj(
584 Sized_relobj
<size
, big_endian
>* relobj
,
585 const unsigned char* syms
,
587 const char* sym_names
,
588 size_t sym_name_size
,
589 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
)
591 gold_assert(size
== relobj
->target()->get_size());
592 gold_assert(size
== parameters
->get_size());
594 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
596 const unsigned char* p
= syms
;
597 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
599 elfcpp::Sym
<size
, big_endian
> sym(p
);
600 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
602 unsigned int st_name
= psym
->get_st_name();
603 if (st_name
>= sym_name_size
)
605 relobj
->error(_("bad global symbol name offset %u at %zu"),
610 const char* name
= sym_names
+ st_name
;
612 // A symbol defined in a section which we are not including must
613 // be treated as an undefined symbol.
614 unsigned char symbuf
[sym_size
];
615 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
616 unsigned int st_shndx
= psym
->get_st_shndx();
617 if (st_shndx
!= elfcpp::SHN_UNDEF
618 && st_shndx
< elfcpp::SHN_LORESERVE
619 && !relobj
->is_section_included(st_shndx
))
621 memcpy(symbuf
, p
, sym_size
);
622 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
623 sw
.put_st_shndx(elfcpp::SHN_UNDEF
);
627 // In an object file, an '@' in the name separates the symbol
628 // name from the version name. If there are two '@' characters,
629 // this is the default version.
630 const char* ver
= strchr(name
, '@');
636 // The symbol name is of the form foo@VERSION or foo@@VERSION
637 namelen
= ver
- name
;
645 else if (!version_script_
.empty())
647 // The symbol name did not have a version, but
648 // the version script may assign a version anyway.
649 namelen
= strlen(name
);
651 const std::string
& version
=
652 version_script_
.get_symbol_version(name
);
653 if (!version
.empty())
654 ver
= version
.c_str();
657 Sized_symbol
<size
>* res
;
660 Stringpool::Key name_key
;
661 name
= this->namepool_
.add(name
, true, &name_key
);
662 res
= this->add_from_object(relobj
, name
, name_key
, NULL
, 0,
667 Stringpool::Key name_key
;
668 name
= this->namepool_
.add_with_length(name
, namelen
, true,
670 Stringpool::Key ver_key
;
671 ver
= this->namepool_
.add(ver
, true, &ver_key
);
673 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
677 (*sympointers
)[i
] = res
;
681 // Add all the symbols in a dynamic object to the hash table.
683 template<int size
, bool big_endian
>
685 Symbol_table::add_from_dynobj(
686 Sized_dynobj
<size
, big_endian
>* dynobj
,
687 const unsigned char* syms
,
689 const char* sym_names
,
690 size_t sym_name_size
,
691 const unsigned char* versym
,
693 const std::vector
<const char*>* version_map
)
695 gold_assert(size
== dynobj
->target()->get_size());
696 gold_assert(size
== parameters
->get_size());
698 if (versym
!= NULL
&& versym_size
/ 2 < count
)
700 dynobj
->error(_("too few symbol versions"));
704 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
706 // We keep a list of all STT_OBJECT symbols, so that we can resolve
707 // weak aliases. This is necessary because if the dynamic object
708 // provides the same variable under two names, one of which is a
709 // weak definition, and the regular object refers to the weak
710 // definition, we have to put both the weak definition and the
711 // strong definition into the dynamic symbol table. Given a weak
712 // definition, the only way that we can find the corresponding
713 // strong definition, if any, is to search the symbol table.
714 std::vector
<Sized_symbol
<size
>*> object_symbols
;
716 const unsigned char* p
= syms
;
717 const unsigned char* vs
= versym
;
718 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
720 elfcpp::Sym
<size
, big_endian
> sym(p
);
722 // Ignore symbols with local binding.
723 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
)
726 unsigned int st_name
= sym
.get_st_name();
727 if (st_name
>= sym_name_size
)
729 dynobj
->error(_("bad symbol name offset %u at %zu"),
734 const char* name
= sym_names
+ st_name
;
736 Sized_symbol
<size
>* res
;
740 Stringpool::Key name_key
;
741 name
= this->namepool_
.add(name
, true, &name_key
);
742 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
747 // Read the version information.
749 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
751 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
752 v
&= elfcpp::VERSYM_VERSION
;
754 // The Sun documentation says that V can be VER_NDX_LOCAL,
755 // or VER_NDX_GLOBAL, or a version index. The meaning of
756 // VER_NDX_LOCAL is defined as "Symbol has local scope."
757 // The old GNU linker will happily generate VER_NDX_LOCAL
758 // for an undefined symbol. I don't know what the Sun
759 // linker will generate.
761 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
762 && sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
764 // This symbol should not be visible outside the object.
768 // At this point we are definitely going to add this symbol.
769 Stringpool::Key name_key
;
770 name
= this->namepool_
.add(name
, true, &name_key
);
772 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
773 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
775 // This symbol does not have a version.
776 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
781 if (v
>= version_map
->size())
783 dynobj
->error(_("versym for symbol %zu out of range: %u"),
788 const char* version
= (*version_map
)[v
];
791 dynobj
->error(_("versym for symbol %zu has no name: %u"),
796 Stringpool::Key version_key
;
797 version
= this->namepool_
.add(version
, true, &version_key
);
799 // If this is an absolute symbol, and the version name
800 // and symbol name are the same, then this is the
801 // version definition symbol. These symbols exist to
802 // support using -u to pull in particular versions. We
803 // do not want to record a version for them.
804 if (sym
.get_st_shndx() == elfcpp::SHN_ABS
805 && name_key
== version_key
)
806 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
810 const bool def
= (!hidden
811 && (sym
.get_st_shndx()
812 != elfcpp::SHN_UNDEF
));
813 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
814 version_key
, def
, sym
, sym
);
819 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
820 && sym
.get_st_type() == elfcpp::STT_OBJECT
)
821 object_symbols
.push_back(res
);
824 this->record_weak_aliases(&object_symbols
);
827 // This is used to sort weak aliases. We sort them first by section
828 // index, then by offset, then by weak ahead of strong.
831 class Weak_alias_sorter
834 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
839 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
840 const Sized_symbol
<size
>* s2
) const
842 if (s1
->shndx() != s2
->shndx())
843 return s1
->shndx() < s2
->shndx();
844 if (s1
->value() != s2
->value())
845 return s1
->value() < s2
->value();
846 if (s1
->binding() != s2
->binding())
848 if (s1
->binding() == elfcpp::STB_WEAK
)
850 if (s2
->binding() == elfcpp::STB_WEAK
)
853 return std::string(s1
->name()) < std::string(s2
->name());
856 // SYMBOLS is a list of object symbols from a dynamic object. Look
857 // for any weak aliases, and record them so that if we add the weak
858 // alias to the dynamic symbol table, we also add the corresponding
863 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
865 // Sort the vector by section index, then by offset, then by weak
867 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
869 // Walk through the vector. For each weak definition, record
871 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
876 if ((*p
)->binding() != elfcpp::STB_WEAK
)
879 // Build a circular list of weak aliases. Each symbol points to
880 // the next one in the circular list.
882 Sized_symbol
<size
>* from_sym
= *p
;
883 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
884 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
886 if ((*q
)->shndx() != from_sym
->shndx()
887 || (*q
)->value() != from_sym
->value())
890 this->weak_aliases_
[from_sym
] = *q
;
891 from_sym
->set_has_alias();
897 this->weak_aliases_
[from_sym
] = *p
;
898 from_sym
->set_has_alias();
905 // Create and return a specially defined symbol. If ONLY_IF_REF is
906 // true, then only create the symbol if there is a reference to it.
907 // If this does not return NULL, it sets *POLDSYM to the existing
908 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
910 template<int size
, bool big_endian
>
912 Symbol_table::define_special_symbol(const Target
* target
, const char** pname
,
913 const char** pversion
, bool only_if_ref
,
914 Sized_symbol
<size
>** poldsym
918 Sized_symbol
<size
>* sym
;
919 bool add_to_table
= false;
920 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
924 oldsym
= this->lookup(*pname
, *pversion
);
925 if (oldsym
== NULL
|| !oldsym
->is_undefined())
928 *pname
= oldsym
->name();
929 *pversion
= oldsym
->version();
933 // Canonicalize NAME and VERSION.
934 Stringpool::Key name_key
;
935 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
937 Stringpool::Key version_key
= 0;
938 if (*pversion
!= NULL
)
939 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
941 Symbol
* const snull
= NULL
;
942 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
943 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
949 // We already have a symbol table entry for NAME/VERSION.
950 oldsym
= ins
.first
->second
;
951 gold_assert(oldsym
!= NULL
);
955 // We haven't seen this symbol before.
956 gold_assert(ins
.first
->second
== NULL
);
963 if (!target
->has_make_symbol())
964 sym
= new Sized_symbol
<size
>();
967 gold_assert(target
->get_size() == size
);
968 gold_assert(target
->is_big_endian() ? big_endian
: !big_endian
);
969 typedef Sized_target
<size
, big_endian
> My_target
;
970 const My_target
* sized_target
=
971 static_cast<const My_target
*>(target
);
972 sym
= sized_target
->make_symbol();
978 add_loc
->second
= sym
;
980 gold_assert(oldsym
!= NULL
);
982 *poldsym
= this->get_sized_symbol
SELECT_SIZE_NAME(size
) (oldsym
988 // Define a symbol based on an Output_data.
991 Symbol_table::define_in_output_data(const Target
* target
, const char* name
,
992 const char* version
, Output_data
* od
,
993 uint64_t value
, uint64_t symsize
,
994 elfcpp::STT type
, elfcpp::STB binding
,
995 elfcpp::STV visibility
,
996 unsigned char nonvis
,
997 bool offset_is_from_end
,
1000 if (parameters
->get_size() == 32)
1002 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1003 return this->do_define_in_output_data
<32>(target
, name
, version
, od
,
1004 value
, symsize
, type
, binding
,
1012 else if (parameters
->get_size() == 64)
1014 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1015 return this->do_define_in_output_data
<64>(target
, name
, version
, od
,
1016 value
, symsize
, type
, binding
,
1028 // Define a symbol in an Output_data, sized version.
1032 Symbol_table::do_define_in_output_data(
1033 const Target
* target
,
1035 const char* version
,
1037 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1038 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1040 elfcpp::STB binding
,
1041 elfcpp::STV visibility
,
1042 unsigned char nonvis
,
1043 bool offset_is_from_end
,
1046 Sized_symbol
<size
>* sym
;
1047 Sized_symbol
<size
>* oldsym
;
1049 if (parameters
->is_big_endian())
1051 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1052 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, true) (
1053 target
, &name
, &version
, only_if_ref
, &oldsym
1054 SELECT_SIZE_ENDIAN(size
, true));
1061 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1062 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, false) (
1063 target
, &name
, &version
, only_if_ref
, &oldsym
1064 SELECT_SIZE_ENDIAN(size
, false));
1073 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1074 sym
->init(name
, od
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1075 offset_is_from_end
);
1080 if (Symbol_table::should_override_with_special(oldsym
))
1081 this->override_with_special(oldsym
, sym
);
1086 // Define a symbol based on an Output_segment.
1089 Symbol_table::define_in_output_segment(const Target
* target
, const char* name
,
1090 const char* version
, Output_segment
* os
,
1091 uint64_t value
, uint64_t symsize
,
1092 elfcpp::STT type
, elfcpp::STB binding
,
1093 elfcpp::STV visibility
,
1094 unsigned char nonvis
,
1095 Symbol::Segment_offset_base offset_base
,
1098 if (parameters
->get_size() == 32)
1100 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1101 return this->do_define_in_output_segment
<32>(target
, name
, version
, os
,
1102 value
, symsize
, type
,
1103 binding
, visibility
, nonvis
,
1104 offset_base
, only_if_ref
);
1109 else if (parameters
->get_size() == 64)
1111 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1112 return this->do_define_in_output_segment
<64>(target
, name
, version
, os
,
1113 value
, symsize
, type
,
1114 binding
, visibility
, nonvis
,
1115 offset_base
, only_if_ref
);
1124 // Define a symbol in an Output_segment, sized version.
1128 Symbol_table::do_define_in_output_segment(
1129 const Target
* target
,
1131 const char* version
,
1133 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1134 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1136 elfcpp::STB binding
,
1137 elfcpp::STV visibility
,
1138 unsigned char nonvis
,
1139 Symbol::Segment_offset_base offset_base
,
1142 Sized_symbol
<size
>* sym
;
1143 Sized_symbol
<size
>* oldsym
;
1145 if (parameters
->is_big_endian())
1147 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1148 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, true) (
1149 target
, &name
, &version
, only_if_ref
, &oldsym
1150 SELECT_SIZE_ENDIAN(size
, true));
1157 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1158 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, false) (
1159 target
, &name
, &version
, only_if_ref
, &oldsym
1160 SELECT_SIZE_ENDIAN(size
, false));
1169 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1170 sym
->init(name
, os
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1176 if (Symbol_table::should_override_with_special(oldsym
))
1177 this->override_with_special(oldsym
, sym
);
1182 // Define a special symbol with a constant value. It is a multiple
1183 // definition error if this symbol is already defined.
1186 Symbol_table::define_as_constant(const Target
* target
, const char* name
,
1187 const char* version
, uint64_t value
,
1188 uint64_t symsize
, elfcpp::STT type
,
1189 elfcpp::STB binding
, elfcpp::STV visibility
,
1190 unsigned char nonvis
, bool only_if_ref
)
1192 if (parameters
->get_size() == 32)
1194 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1195 return this->do_define_as_constant
<32>(target
, name
, version
, value
,
1196 symsize
, type
, binding
,
1197 visibility
, nonvis
, only_if_ref
);
1202 else if (parameters
->get_size() == 64)
1204 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1205 return this->do_define_as_constant
<64>(target
, name
, version
, value
,
1206 symsize
, type
, binding
,
1207 visibility
, nonvis
, only_if_ref
);
1216 // Define a symbol as a constant, sized version.
1220 Symbol_table::do_define_as_constant(
1221 const Target
* target
,
1223 const char* version
,
1224 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1225 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1227 elfcpp::STB binding
,
1228 elfcpp::STV visibility
,
1229 unsigned char nonvis
,
1232 Sized_symbol
<size
>* sym
;
1233 Sized_symbol
<size
>* oldsym
;
1235 if (parameters
->is_big_endian())
1237 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1238 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, true) (
1239 target
, &name
, &version
, only_if_ref
, &oldsym
1240 SELECT_SIZE_ENDIAN(size
, true));
1247 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1248 sym
= this->define_special_symbol
SELECT_SIZE_ENDIAN_NAME(size
, false) (
1249 target
, &name
, &version
, only_if_ref
, &oldsym
1250 SELECT_SIZE_ENDIAN(size
, false));
1259 gold_assert(version
== NULL
|| version
== name
|| oldsym
!= NULL
);
1260 sym
->init(name
, value
, symsize
, type
, binding
, visibility
, nonvis
);
1265 if (Symbol_table::should_override_with_special(oldsym
))
1266 this->override_with_special(oldsym
, sym
);
1271 // Define a set of symbols in output sections.
1274 Symbol_table::define_symbols(const Layout
* layout
, const Target
* target
,
1275 int count
, const Define_symbol_in_section
* p
)
1277 for (int i
= 0; i
< count
; ++i
, ++p
)
1279 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1281 this->define_in_output_data(target
, p
->name
, NULL
, os
, p
->value
,
1282 p
->size
, p
->type
, p
->binding
,
1283 p
->visibility
, p
->nonvis
,
1284 p
->offset_is_from_end
, p
->only_if_ref
);
1286 this->define_as_constant(target
, p
->name
, NULL
, 0, p
->size
, p
->type
,
1287 p
->binding
, p
->visibility
, p
->nonvis
,
1292 // Define a set of symbols in output segments.
1295 Symbol_table::define_symbols(const Layout
* layout
, const Target
* target
,
1296 int count
, const Define_symbol_in_segment
* p
)
1298 for (int i
= 0; i
< count
; ++i
, ++p
)
1300 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1301 p
->segment_flags_set
,
1302 p
->segment_flags_clear
);
1304 this->define_in_output_segment(target
, p
->name
, NULL
, os
, p
->value
,
1305 p
->size
, p
->type
, p
->binding
,
1306 p
->visibility
, p
->nonvis
,
1307 p
->offset_base
, p
->only_if_ref
);
1309 this->define_as_constant(target
, p
->name
, NULL
, 0, p
->size
, p
->type
,
1310 p
->binding
, p
->visibility
, p
->nonvis
,
1315 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1316 // symbol should be defined--typically a .dyn.bss section. VALUE is
1317 // the offset within POSD.
1321 Symbol_table::define_with_copy_reloc(
1322 const Target
* target
,
1323 Sized_symbol
<size
>* csym
,
1325 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1327 gold_assert(csym
->is_from_dynobj());
1328 gold_assert(!csym
->is_copied_from_dynobj());
1329 Object
* object
= csym
->object();
1330 gold_assert(object
->is_dynamic());
1331 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1333 // Our copied variable has to override any variable in a shared
1335 elfcpp::STB binding
= csym
->binding();
1336 if (binding
== elfcpp::STB_WEAK
)
1337 binding
= elfcpp::STB_GLOBAL
;
1339 this->define_in_output_data(target
, csym
->name(), csym
->version(),
1340 posd
, value
, csym
->symsize(),
1341 csym
->type(), binding
,
1342 csym
->visibility(), csym
->nonvis(),
1345 csym
->set_is_copied_from_dynobj();
1346 csym
->set_needs_dynsym_entry();
1348 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1350 // We have now defined all aliases, but we have not entered them all
1351 // in the copied_symbol_dynobjs_ map.
1352 if (csym
->has_alias())
1357 sym
= this->weak_aliases_
[sym
];
1360 gold_assert(sym
->output_data() == posd
);
1362 sym
->set_is_copied_from_dynobj();
1363 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1368 // SYM is defined using a COPY reloc. Return the dynamic object where
1369 // the original definition was found.
1372 Symbol_table::get_copy_source(const Symbol
* sym
) const
1374 gold_assert(sym
->is_copied_from_dynobj());
1375 Copied_symbol_dynobjs::const_iterator p
=
1376 this->copied_symbol_dynobjs_
.find(sym
);
1377 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1381 // Set the dynamic symbol indexes. INDEX is the index of the first
1382 // global dynamic symbol. Pointers to the symbols are stored into the
1383 // vector SYMS. The names are added to DYNPOOL. This returns an
1384 // updated dynamic symbol index.
1387 Symbol_table::set_dynsym_indexes(const Target
* target
,
1389 std::vector
<Symbol
*>* syms
,
1390 Stringpool
* dynpool
,
1393 for (Symbol_table_type::iterator p
= this->table_
.begin();
1394 p
!= this->table_
.end();
1397 Symbol
* sym
= p
->second
;
1399 // Note that SYM may already have a dynamic symbol index, since
1400 // some symbols appear more than once in the symbol table, with
1401 // and without a version.
1403 if (!sym
->should_add_dynsym_entry())
1404 sym
->set_dynsym_index(-1U);
1405 else if (!sym
->has_dynsym_index())
1407 sym
->set_dynsym_index(index
);
1409 syms
->push_back(sym
);
1410 dynpool
->add(sym
->name(), false, NULL
);
1412 // Record any version information.
1413 if (sym
->version() != NULL
)
1414 versions
->record_version(this, dynpool
, sym
);
1418 // Finish up the versions. In some cases this may add new dynamic
1420 index
= versions
->finalize(target
, this, index
, syms
);
1425 // Set the final values for all the symbols. The index of the first
1426 // global symbol in the output file is INDEX. Record the file offset
1427 // OFF. Add their names to POOL. Return the new file offset.
1430 Symbol_table::finalize(unsigned int index
, off_t off
, off_t dynoff
,
1431 size_t dyn_global_index
, size_t dyncount
,
1436 gold_assert(index
!= 0);
1437 this->first_global_index_
= index
;
1439 this->dynamic_offset_
= dynoff
;
1440 this->first_dynamic_global_index_
= dyn_global_index
;
1441 this->dynamic_count_
= dyncount
;
1443 if (parameters
->get_size() == 32)
1445 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1446 ret
= this->sized_finalize
<32>(index
, off
, pool
);
1451 else if (parameters
->get_size() == 64)
1453 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1454 ret
= this->sized_finalize
<64>(index
, off
, pool
);
1462 // Now that we have the final symbol table, we can reliably note
1463 // which symbols should get warnings.
1464 this->warnings_
.note_warnings(this);
1469 // Set the final value for all the symbols. This is called after
1470 // Layout::finalize, so all the output sections have their final
1475 Symbol_table::sized_finalize(unsigned index
, off_t off
, Stringpool
* pool
)
1477 off
= align_address(off
, size
>> 3);
1478 this->offset_
= off
;
1480 size_t orig_index
= index
;
1482 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1483 for (Symbol_table_type::iterator p
= this->table_
.begin();
1484 p
!= this->table_
.end();
1487 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1489 // FIXME: Here we need to decide which symbols should go into
1490 // the output file, based on --strip.
1492 // The default version of a symbol may appear twice in the
1493 // symbol table. We only need to finalize it once.
1494 if (sym
->has_symtab_index())
1499 gold_assert(!sym
->has_symtab_index());
1500 sym
->set_symtab_index(-1U);
1501 gold_assert(sym
->dynsym_index() == -1U);
1505 typename Sized_symbol
<size
>::Value_type value
;
1507 switch (sym
->source())
1509 case Symbol::FROM_OBJECT
:
1511 unsigned int shndx
= sym
->shndx();
1513 // FIXME: We need some target specific support here.
1514 if (shndx
>= elfcpp::SHN_LORESERVE
1515 && shndx
!= elfcpp::SHN_ABS
)
1517 gold_error(_("%s: unsupported symbol section 0x%x"),
1518 sym
->demangled_name().c_str(), shndx
);
1519 shndx
= elfcpp::SHN_UNDEF
;
1522 Object
* symobj
= sym
->object();
1523 if (symobj
->is_dynamic())
1526 shndx
= elfcpp::SHN_UNDEF
;
1528 else if (shndx
== elfcpp::SHN_UNDEF
)
1530 else if (shndx
== elfcpp::SHN_ABS
)
1531 value
= sym
->value();
1534 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1535 section_offset_type secoff
;
1536 Output_section
* os
= relobj
->output_section(shndx
, &secoff
);
1540 sym
->set_symtab_index(-1U);
1541 gold_assert(sym
->dynsym_index() == -1U);
1545 if (sym
->type() == elfcpp::STT_TLS
)
1546 value
= sym
->value() + os
->tls_offset() + secoff
;
1548 value
= sym
->value() + os
->address() + secoff
;
1553 case Symbol::IN_OUTPUT_DATA
:
1555 Output_data
* od
= sym
->output_data();
1556 value
= sym
->value() + od
->address();
1557 if (sym
->offset_is_from_end())
1558 value
+= od
->data_size();
1562 case Symbol::IN_OUTPUT_SEGMENT
:
1564 Output_segment
* os
= sym
->output_segment();
1565 value
= sym
->value() + os
->vaddr();
1566 switch (sym
->offset_base())
1568 case Symbol::SEGMENT_START
:
1570 case Symbol::SEGMENT_END
:
1571 value
+= os
->memsz();
1573 case Symbol::SEGMENT_BSS
:
1574 value
+= os
->filesz();
1582 case Symbol::CONSTANT
:
1583 value
= sym
->value();
1590 sym
->set_value(value
);
1592 if (parameters
->strip_all())
1593 sym
->set_symtab_index(-1U);
1596 sym
->set_symtab_index(index
);
1597 pool
->add(sym
->name(), false, NULL
);
1603 this->output_count_
= index
- orig_index
;
1608 // Write out the global symbols.
1611 Symbol_table::write_globals(const Input_objects
* input_objects
,
1612 const Stringpool
* sympool
,
1613 const Stringpool
* dynpool
, Output_file
* of
) const
1615 if (parameters
->get_size() == 32)
1617 if (parameters
->is_big_endian())
1619 #ifdef HAVE_TARGET_32_BIG
1620 this->sized_write_globals
<32, true>(input_objects
, sympool
,
1628 #ifdef HAVE_TARGET_32_LITTLE
1629 this->sized_write_globals
<32, false>(input_objects
, sympool
,
1636 else if (parameters
->get_size() == 64)
1638 if (parameters
->is_big_endian())
1640 #ifdef HAVE_TARGET_64_BIG
1641 this->sized_write_globals
<64, true>(input_objects
, sympool
,
1649 #ifdef HAVE_TARGET_64_LITTLE
1650 this->sized_write_globals
<64, false>(input_objects
, sympool
,
1661 // Write out the global symbols.
1663 template<int size
, bool big_endian
>
1665 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
1666 const Stringpool
* sympool
,
1667 const Stringpool
* dynpool
,
1668 Output_file
* of
) const
1670 const Target
* const target
= input_objects
->target();
1672 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1673 unsigned int index
= this->first_global_index_
;
1674 const off_t oview_size
= this->output_count_
* sym_size
;
1675 unsigned char* const psyms
= of
->get_output_view(this->offset_
, oview_size
);
1677 unsigned int dynamic_count
= this->dynamic_count_
;
1678 off_t dynamic_size
= dynamic_count
* sym_size
;
1679 unsigned int first_dynamic_global_index
= this->first_dynamic_global_index_
;
1680 unsigned char* dynamic_view
;
1681 if (this->dynamic_offset_
== 0)
1682 dynamic_view
= NULL
;
1684 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
1686 unsigned char* ps
= psyms
;
1687 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1688 p
!= this->table_
.end();
1691 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1693 // Possibly warn about unresolved symbols in shared libraries.
1694 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
1696 unsigned int sym_index
= sym
->symtab_index();
1697 unsigned int dynsym_index
;
1698 if (dynamic_view
== NULL
)
1701 dynsym_index
= sym
->dynsym_index();
1703 if (sym_index
== -1U && dynsym_index
== -1U)
1705 // This symbol is not included in the output file.
1709 if (sym_index
== index
)
1711 else if (sym_index
!= -1U)
1713 // We have already seen this symbol, because it has a
1715 gold_assert(sym_index
< index
);
1716 if (dynsym_index
== -1U)
1722 typename
elfcpp::Elf_types
<32>::Elf_Addr value
= sym
->value();
1723 switch (sym
->source())
1725 case Symbol::FROM_OBJECT
:
1727 unsigned int in_shndx
= sym
->shndx();
1729 // FIXME: We need some target specific support here.
1730 if (in_shndx
>= elfcpp::SHN_LORESERVE
1731 && in_shndx
!= elfcpp::SHN_ABS
)
1733 gold_error(_("%s: unsupported symbol section 0x%x"),
1734 sym
->demangled_name().c_str(), in_shndx
);
1739 Object
* symobj
= sym
->object();
1740 if (symobj
->is_dynamic())
1742 if (sym
->needs_dynsym_value())
1743 value
= target
->dynsym_value(sym
);
1744 shndx
= elfcpp::SHN_UNDEF
;
1746 else if (in_shndx
== elfcpp::SHN_UNDEF
1747 || in_shndx
== elfcpp::SHN_ABS
)
1751 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1752 section_offset_type secoff
;
1753 Output_section
* os
= relobj
->output_section(in_shndx
,
1755 gold_assert(os
!= NULL
);
1756 shndx
= os
->out_shndx();
1762 case Symbol::IN_OUTPUT_DATA
:
1763 shndx
= sym
->output_data()->out_shndx();
1766 case Symbol::IN_OUTPUT_SEGMENT
:
1767 shndx
= elfcpp::SHN_ABS
;
1770 case Symbol::CONSTANT
:
1771 shndx
= elfcpp::SHN_ABS
;
1778 if (sym_index
!= -1U)
1780 this->sized_write_symbol
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
1781 sym
, sym
->value(), shndx
, sympool
, ps
1782 SELECT_SIZE_ENDIAN(size
, big_endian
));
1786 if (dynsym_index
!= -1U)
1788 dynsym_index
-= first_dynamic_global_index
;
1789 gold_assert(dynsym_index
< dynamic_count
);
1790 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
1791 this->sized_write_symbol
SELECT_SIZE_ENDIAN_NAME(size
, big_endian
) (
1792 sym
, value
, shndx
, dynpool
, pd
1793 SELECT_SIZE_ENDIAN(size
, big_endian
));
1797 gold_assert(ps
- psyms
== oview_size
);
1799 of
->write_output_view(this->offset_
, oview_size
, psyms
);
1800 if (dynamic_view
!= NULL
)
1801 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
1804 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1805 // strtab holding the name.
1807 template<int size
, bool big_endian
>
1809 Symbol_table::sized_write_symbol(
1810 Sized_symbol
<size
>* sym
,
1811 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1813 const Stringpool
* pool
,
1815 ACCEPT_SIZE_ENDIAN
) const
1817 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
1818 osym
.put_st_name(pool
->get_offset(sym
->name()));
1819 osym
.put_st_value(value
);
1820 osym
.put_st_size(sym
->symsize());
1821 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
1822 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
1823 osym
.put_st_shndx(shndx
);
1826 // Check for unresolved symbols in shared libraries. This is
1827 // controlled by the --allow-shlib-undefined option.
1829 // We only warn about libraries for which we have seen all the
1830 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
1831 // which were not seen in this link. If we didn't see a DT_NEEDED
1832 // entry, we aren't going to be able to reliably report whether the
1833 // symbol is undefined.
1835 // We also don't warn about libraries found in the system library
1836 // directory (the directory were we find libc.so); we assume that
1837 // those libraries are OK. This heuristic avoids problems in
1838 // GNU/Linux, in which -ldl can have undefined references satisfied by
1842 Symbol_table::warn_about_undefined_dynobj_symbol(
1843 const Input_objects
* input_objects
,
1846 if (sym
->source() == Symbol::FROM_OBJECT
1847 && sym
->object()->is_dynamic()
1848 && sym
->shndx() == elfcpp::SHN_UNDEF
1849 && sym
->binding() != elfcpp::STB_WEAK
1850 && !parameters
->allow_shlib_undefined()
1851 && !input_objects
->target()->is_defined_by_abi(sym
)
1852 && !input_objects
->found_in_system_library_directory(sym
->object()))
1854 // A very ugly cast.
1855 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
1856 if (!dynobj
->has_unknown_needed_entries())
1857 gold_error(_("%s: undefined reference to '%s'"),
1858 sym
->object()->name().c_str(),
1859 sym
->demangled_name().c_str());
1863 // Write out a section symbol. Return the update offset.
1866 Symbol_table::write_section_symbol(const Output_section
*os
,
1870 if (parameters
->get_size() == 32)
1872 if (parameters
->is_big_endian())
1874 #ifdef HAVE_TARGET_32_BIG
1875 this->sized_write_section_symbol
<32, true>(os
, of
, offset
);
1882 #ifdef HAVE_TARGET_32_LITTLE
1883 this->sized_write_section_symbol
<32, false>(os
, of
, offset
);
1889 else if (parameters
->get_size() == 64)
1891 if (parameters
->is_big_endian())
1893 #ifdef HAVE_TARGET_64_BIG
1894 this->sized_write_section_symbol
<64, true>(os
, of
, offset
);
1901 #ifdef HAVE_TARGET_64_LITTLE
1902 this->sized_write_section_symbol
<64, false>(os
, of
, offset
);
1912 // Write out a section symbol, specialized for size and endianness.
1914 template<int size
, bool big_endian
>
1916 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
1920 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1922 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
1924 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
1925 osym
.put_st_name(0);
1926 osym
.put_st_value(os
->address());
1927 osym
.put_st_size(0);
1928 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
1929 elfcpp::STT_SECTION
));
1930 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
1931 osym
.put_st_shndx(os
->out_shndx());
1933 of
->write_output_view(offset
, sym_size
, pov
);
1936 // Print statistical information to stderr. This is used for --stats.
1939 Symbol_table::print_stats() const
1941 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
1942 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
1943 program_name
, this->table_
.size(), this->table_
.bucket_count());
1945 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
1946 program_name
, this->table_
.size());
1948 this->namepool_
.print_stats("symbol table stringpool");
1951 // We check for ODR violations by looking for symbols with the same
1952 // name for which the debugging information reports that they were
1953 // defined in different source locations. When comparing the source
1954 // location, we consider instances with the same base filename and
1955 // line number to be the same. This is because different object
1956 // files/shared libraries can include the same header file using
1957 // different paths, and we don't want to report an ODR violation in
1960 // This struct is used to compare line information, as returned by
1961 // Dwarf_line_info::one_addr2line. It implements a < comparison
1962 // operator used with std::set.
1964 struct Odr_violation_compare
1967 operator()(const std::string
& s1
, const std::string
& s2
) const
1969 std::string::size_type pos1
= s1
.rfind('/');
1970 std::string::size_type pos2
= s2
.rfind('/');
1971 if (pos1
== std::string::npos
1972 || pos2
== std::string::npos
)
1974 return s1
.compare(pos1
, std::string::npos
,
1975 s2
, pos2
, std::string::npos
) < 0;
1979 // Check candidate_odr_violations_ to find symbols with the same name
1980 // but apparently different definitions (different source-file/line-no).
1983 Symbol_table::detect_odr_violations(const Task
* task
,
1984 const char* output_file_name
) const
1986 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
1987 it
!= candidate_odr_violations_
.end();
1990 const char* symbol_name
= it
->first
;
1991 // We use a sorted set so the output is deterministic.
1992 std::set
<std::string
, Odr_violation_compare
> line_nums
;
1994 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
1995 locs
= it
->second
.begin();
1996 locs
!= it
->second
.end();
1999 // We need to lock the object in order to read it. This
2000 // means that we have to run in a singleton Task. If we
2001 // want to run this in a general Task for better
2002 // performance, we will need one Task for object, plus
2003 // appropriate locking to ensure that we don't conflict with
2004 // other uses of the object.
2005 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2006 std::string lineno
= Dwarf_line_info::one_addr2line(
2007 locs
->object
, locs
->shndx
, locs
->offset
);
2008 if (!lineno
.empty())
2009 line_nums
.insert(lineno
);
2012 if (line_nums
.size() > 1)
2014 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2015 "places (possible ODR violation):"),
2016 output_file_name
, demangle(symbol_name
).c_str());
2017 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2018 it2
!= line_nums
.end();
2020 fprintf(stderr
, " %s\n", it2
->c_str());
2025 // Warnings functions.
2027 // Add a new warning.
2030 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2031 const std::string
& warning
)
2033 name
= symtab
->canonicalize_name(name
);
2034 this->warnings_
[name
].set(obj
, warning
);
2037 // Look through the warnings and mark the symbols for which we should
2038 // warn. This is called during Layout::finalize when we know the
2039 // sources for all the symbols.
2042 Warnings::note_warnings(Symbol_table
* symtab
)
2044 for (Warning_table::iterator p
= this->warnings_
.begin();
2045 p
!= this->warnings_
.end();
2048 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2050 && sym
->source() == Symbol::FROM_OBJECT
2051 && sym
->object() == p
->second
.object
)
2052 sym
->set_has_warning();
2056 // Issue a warning. This is called when we see a relocation against a
2057 // symbol for which has a warning.
2059 template<int size
, bool big_endian
>
2061 Warnings::issue_warning(const Symbol
* sym
,
2062 const Relocate_info
<size
, big_endian
>* relinfo
,
2063 size_t relnum
, off_t reloffset
) const
2065 gold_assert(sym
->has_warning());
2066 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2067 gold_assert(p
!= this->warnings_
.end());
2068 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2069 "%s", p
->second
.text
.c_str());
2072 // Instantiate the templates we need. We could use the configure
2073 // script to restrict this to only the ones needed for implemented
2076 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2079 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2082 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2085 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2088 #ifdef HAVE_TARGET_32_LITTLE
2091 Symbol_table::add_from_relobj
<32, false>(
2092 Sized_relobj
<32, false>* relobj
,
2093 const unsigned char* syms
,
2095 const char* sym_names
,
2096 size_t sym_name_size
,
2097 Sized_relobj
<32, true>::Symbols
* sympointers
);
2100 #ifdef HAVE_TARGET_32_BIG
2103 Symbol_table::add_from_relobj
<32, true>(
2104 Sized_relobj
<32, true>* relobj
,
2105 const unsigned char* syms
,
2107 const char* sym_names
,
2108 size_t sym_name_size
,
2109 Sized_relobj
<32, false>::Symbols
* sympointers
);
2112 #ifdef HAVE_TARGET_64_LITTLE
2115 Symbol_table::add_from_relobj
<64, false>(
2116 Sized_relobj
<64, false>* relobj
,
2117 const unsigned char* syms
,
2119 const char* sym_names
,
2120 size_t sym_name_size
,
2121 Sized_relobj
<64, true>::Symbols
* sympointers
);
2124 #ifdef HAVE_TARGET_64_BIG
2127 Symbol_table::add_from_relobj
<64, true>(
2128 Sized_relobj
<64, true>* relobj
,
2129 const unsigned char* syms
,
2131 const char* sym_names
,
2132 size_t sym_name_size
,
2133 Sized_relobj
<64, false>::Symbols
* sympointers
);
2136 #ifdef HAVE_TARGET_32_LITTLE
2139 Symbol_table::add_from_dynobj
<32, false>(
2140 Sized_dynobj
<32, false>* dynobj
,
2141 const unsigned char* syms
,
2143 const char* sym_names
,
2144 size_t sym_name_size
,
2145 const unsigned char* versym
,
2147 const std::vector
<const char*>* version_map
);
2150 #ifdef HAVE_TARGET_32_BIG
2153 Symbol_table::add_from_dynobj
<32, true>(
2154 Sized_dynobj
<32, true>* dynobj
,
2155 const unsigned char* syms
,
2157 const char* sym_names
,
2158 size_t sym_name_size
,
2159 const unsigned char* versym
,
2161 const std::vector
<const char*>* version_map
);
2164 #ifdef HAVE_TARGET_64_LITTLE
2167 Symbol_table::add_from_dynobj
<64, false>(
2168 Sized_dynobj
<64, false>* dynobj
,
2169 const unsigned char* syms
,
2171 const char* sym_names
,
2172 size_t sym_name_size
,
2173 const unsigned char* versym
,
2175 const std::vector
<const char*>* version_map
);
2178 #ifdef HAVE_TARGET_64_BIG
2181 Symbol_table::add_from_dynobj
<64, true>(
2182 Sized_dynobj
<64, true>* dynobj
,
2183 const unsigned char* syms
,
2185 const char* sym_names
,
2186 size_t sym_name_size
,
2187 const unsigned char* versym
,
2189 const std::vector
<const char*>* version_map
);
2192 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2195 Symbol_table::define_with_copy_reloc
<32>(
2196 const Target
* target
,
2197 Sized_symbol
<32>* sym
,
2199 elfcpp::Elf_types
<32>::Elf_Addr value
);
2202 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2205 Symbol_table::define_with_copy_reloc
<64>(
2206 const Target
* target
,
2207 Sized_symbol
<64>* sym
,
2209 elfcpp::Elf_types
<64>::Elf_Addr value
);
2212 #ifdef HAVE_TARGET_32_LITTLE
2215 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
2216 const Relocate_info
<32, false>* relinfo
,
2217 size_t relnum
, off_t reloffset
) const;
2220 #ifdef HAVE_TARGET_32_BIG
2223 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
2224 const Relocate_info
<32, true>* relinfo
,
2225 size_t relnum
, off_t reloffset
) const;
2228 #ifdef HAVE_TARGET_64_LITTLE
2231 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
2232 const Relocate_info
<64, false>* relinfo
,
2233 size_t relnum
, off_t reloffset
) const;
2236 #ifdef HAVE_TARGET_64_BIG
2239 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
2240 const Relocate_info
<64, true>* relinfo
,
2241 size_t relnum
, off_t reloffset
) const;
2244 } // End namespace gold.