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
->options().do_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
->options().export_dynamic() || parameters
->options().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
->options().shared() || parameters
->options().relocatable())
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 the output section where this symbol is defined.
304 Symbol::output_section() const
306 switch (this->source_
)
310 unsigned int shndx
= this->u_
.from_object
.shndx
;
311 if (shndx
!= elfcpp::SHN_UNDEF
&& shndx
< elfcpp::SHN_LORESERVE
)
313 gold_assert(!this->u_
.from_object
.object
->is_dynamic());
314 Relobj
* relobj
= static_cast<Relobj
*>(this->u_
.from_object
.object
);
315 section_offset_type dummy
;
316 return relobj
->output_section(shndx
, &dummy
);
322 return this->u_
.in_output_data
.output_data
->output_section();
324 case IN_OUTPUT_SEGMENT
:
333 // Set the symbol's output section. This is used for symbols defined
334 // in scripts. This should only be called after the symbol table has
338 Symbol::set_output_section(Output_section
* os
)
340 switch (this->source_
)
344 gold_assert(this->output_section() == os
);
347 this->source_
= IN_OUTPUT_DATA
;
348 this->u_
.in_output_data
.output_data
= os
;
349 this->u_
.in_output_data
.offset_is_from_end
= false;
351 case IN_OUTPUT_SEGMENT
:
357 // Class Symbol_table.
359 Symbol_table::Symbol_table(unsigned int count
,
360 const Version_script_info
& version_script
)
361 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
362 forwarders_(), commons_(), forced_locals_(), warnings_(),
363 version_script_(version_script
)
365 namepool_
.reserve(count
);
368 Symbol_table::~Symbol_table()
372 // The hash function. The key values are Stringpool keys.
375 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key
& key
) const
377 return key
.first
^ key
.second
;
380 // The symbol table key equality function. This is called with
384 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
385 const Symbol_table_key
& k2
) const
387 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
390 // Make TO a symbol which forwards to FROM.
393 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
395 gold_assert(from
!= to
);
396 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
397 this->forwarders_
[from
] = to
;
398 from
->set_forwarder();
401 // Resolve the forwards from FROM, returning the real symbol.
404 Symbol_table::resolve_forwards(const Symbol
* from
) const
406 gold_assert(from
->is_forwarder());
407 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
408 this->forwarders_
.find(from
);
409 gold_assert(p
!= this->forwarders_
.end());
413 // Look up a symbol by name.
416 Symbol_table::lookup(const char* name
, const char* version
) const
418 Stringpool::Key name_key
;
419 name
= this->namepool_
.find(name
, &name_key
);
423 Stringpool::Key version_key
= 0;
426 version
= this->namepool_
.find(version
, &version_key
);
431 Symbol_table_key
key(name_key
, version_key
);
432 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
433 if (p
== this->table_
.end())
438 // Resolve a Symbol with another Symbol. This is only used in the
439 // unusual case where there are references to both an unversioned
440 // symbol and a symbol with a version, and we then discover that that
441 // version is the default version. Because this is unusual, we do
442 // this the slow way, by converting back to an ELF symbol.
444 template<int size
, bool big_endian
>
446 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
,
449 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
450 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
451 // We don't bother to set the st_name field.
452 esym
.put_st_value(from
->value());
453 esym
.put_st_size(from
->symsize());
454 esym
.put_st_info(from
->binding(), from
->type());
455 esym
.put_st_other(from
->visibility(), from
->nonvis());
456 esym
.put_st_shndx(from
->shndx());
457 this->resolve(to
, esym
.sym(), esym
.sym(), from
->object(), version
);
464 // Record that a symbol is forced to be local by a version script.
467 Symbol_table::force_local(Symbol
* sym
)
469 if (!sym
->is_defined() && !sym
->is_common())
471 if (sym
->is_forced_local())
473 // We already got this one.
476 sym
->set_is_forced_local();
477 this->forced_locals_
.push_back(sym
);
480 // Add one symbol from OBJECT to the symbol table. NAME is symbol
481 // name and VERSION is the version; both are canonicalized. DEF is
482 // whether this is the default version.
484 // If DEF is true, then this is the definition of a default version of
485 // a symbol. That means that any lookup of NAME/NULL and any lookup
486 // of NAME/VERSION should always return the same symbol. This is
487 // obvious for references, but in particular we want to do this for
488 // definitions: overriding NAME/NULL should also override
489 // NAME/VERSION. If we don't do that, it would be very hard to
490 // override functions in a shared library which uses versioning.
492 // We implement this by simply making both entries in the hash table
493 // point to the same Symbol structure. That is easy enough if this is
494 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
495 // that we have seen both already, in which case they will both have
496 // independent entries in the symbol table. We can't simply change
497 // the symbol table entry, because we have pointers to the entries
498 // attached to the object files. So we mark the entry attached to the
499 // object file as a forwarder, and record it in the forwarders_ map.
500 // Note that entries in the hash table will never be marked as
503 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
504 // symbol exactly as it existed in the input file. SYM is usually
505 // that as well, but can be modified, for instance if we determine
506 // it's in a to-be-discarded section.
508 template<int size
, bool big_endian
>
510 Symbol_table::add_from_object(Object
* object
,
512 Stringpool::Key name_key
,
514 Stringpool::Key version_key
,
516 const elfcpp::Sym
<size
, big_endian
>& sym
,
517 const elfcpp::Sym
<size
, big_endian
>& orig_sym
)
519 Symbol
* const snull
= NULL
;
520 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
521 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
524 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
525 std::make_pair(this->table_
.end(), false);
528 const Stringpool::Key vnull_key
= 0;
529 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
534 // ins.first: an iterator, which is a pointer to a pair.
535 // ins.first->first: the key (a pair of name and version).
536 // ins.first->second: the value (Symbol*).
537 // ins.second: true if new entry was inserted, false if not.
539 Sized_symbol
<size
>* ret
;
544 // We already have an entry for NAME/VERSION.
545 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
546 gold_assert(ret
!= NULL
);
548 was_undefined
= ret
->is_undefined();
549 was_common
= ret
->is_common();
551 this->resolve(ret
, sym
, orig_sym
, object
, version
);
557 // This is the first time we have seen NAME/NULL. Make
558 // NAME/NULL point to NAME/VERSION.
559 insdef
.first
->second
= ret
;
561 else if (insdef
.first
->second
!= ret
562 && insdef
.first
->second
->is_undefined())
564 // This is the unfortunate case where we already have
565 // entries for both NAME/VERSION and NAME/NULL. Note
566 // that we don't want to combine them if the existing
567 // symbol is going to override the new one. FIXME: We
568 // currently just test is_undefined, but this may not do
569 // the right thing if the existing symbol is from a
570 // shared library and the new one is from a regular
573 const Sized_symbol
<size
>* sym2
;
574 sym2
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
575 Symbol_table::resolve
<size
, big_endian
>(ret
, sym2
, version
);
576 this->make_forwarder(insdef
.first
->second
, ret
);
577 insdef
.first
->second
= ret
;
583 // This is the first time we have seen NAME/VERSION.
584 gold_assert(ins
.first
->second
== NULL
);
586 was_undefined
= false;
589 if (def
&& !insdef
.second
)
591 // We already have an entry for NAME/NULL. If we override
592 // it, then change it to NAME/VERSION.
593 ret
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
594 this->resolve(ret
, sym
, orig_sym
, object
, version
);
595 ins
.first
->second
= ret
;
599 Sized_target
<size
, big_endian
>* target
=
600 object
->sized_target
<size
, big_endian
>();
601 if (!target
->has_make_symbol())
602 ret
= new Sized_symbol
<size
>();
605 ret
= target
->make_symbol();
608 // This means that we don't want a symbol table
611 this->table_
.erase(ins
.first
);
614 this->table_
.erase(insdef
.first
);
615 // Inserting insdef invalidated ins.
616 this->table_
.erase(std::make_pair(name_key
,
623 ret
->init(name
, version
, object
, sym
);
625 ins
.first
->second
= ret
;
628 // This is the first time we have seen NAME/NULL. Point
629 // it at the new entry for NAME/VERSION.
630 gold_assert(insdef
.second
);
631 insdef
.first
->second
= ret
;
636 // Record every time we see a new undefined symbol, to speed up
638 if (!was_undefined
&& ret
->is_undefined())
639 ++this->saw_undefined_
;
641 // Keep track of common symbols, to speed up common symbol
643 if (!was_common
&& ret
->is_common())
644 this->commons_
.push_back(ret
);
647 ret
->set_is_default();
651 // Add all the symbols in a relocatable object to the hash table.
653 template<int size
, bool big_endian
>
655 Symbol_table::add_from_relobj(
656 Sized_relobj
<size
, big_endian
>* relobj
,
657 const unsigned char* syms
,
659 const char* sym_names
,
660 size_t sym_name_size
,
661 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
)
663 gold_assert(size
== relobj
->target()->get_size());
664 gold_assert(size
== parameters
->target().get_size());
666 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
668 const bool just_symbols
= relobj
->just_symbols();
670 const unsigned char* p
= syms
;
671 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
673 elfcpp::Sym
<size
, big_endian
> sym(p
);
674 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
676 unsigned int st_name
= psym
->get_st_name();
677 if (st_name
>= sym_name_size
)
679 relobj
->error(_("bad global symbol name offset %u at %zu"),
684 const char* name
= sym_names
+ st_name
;
686 // A symbol defined in a section which we are not including must
687 // be treated as an undefined symbol.
688 unsigned char symbuf
[sym_size
];
689 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
690 unsigned int st_shndx
= psym
->get_st_shndx();
691 if (st_shndx
!= elfcpp::SHN_UNDEF
692 && st_shndx
< elfcpp::SHN_LORESERVE
693 && !relobj
->is_section_included(st_shndx
))
695 memcpy(symbuf
, p
, sym_size
);
696 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
697 sw
.put_st_shndx(elfcpp::SHN_UNDEF
);
701 // In an object file, an '@' in the name separates the symbol
702 // name from the version name. If there are two '@' characters,
703 // this is the default version.
704 const char* ver
= strchr(name
, '@');
706 // DEF: is the version default? LOCAL: is the symbol forced local?
712 // The symbol name is of the form foo@VERSION or foo@@VERSION
713 namelen
= ver
- name
;
721 else if (!version_script_
.empty())
723 // The symbol name did not have a version, but
724 // the version script may assign a version anyway.
725 namelen
= strlen(name
);
727 // Check the global: entries from the version script.
728 const std::string
& version
=
729 version_script_
.get_symbol_version(name
);
730 if (!version
.empty())
731 ver
= version
.c_str();
732 // Check the local: entries from the version script
733 if (version_script_
.symbol_is_local(name
))
740 memcpy(symbuf
, p
, sym_size
);
741 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
742 sw
.put_st_shndx(elfcpp::SHN_ABS
);
743 if (st_shndx
!= elfcpp::SHN_UNDEF
744 && st_shndx
< elfcpp::SHN_LORESERVE
)
746 // Symbol values in object files are section relative.
747 // This is normally what we want, but since here we are
748 // converting the symbol to absolute we need to add the
749 // section address. The section address in an object
750 // file is normally zero, but people can use a linker
751 // script to change it.
752 sw
.put_st_value(sym2
.get_st_value()
753 + relobj
->section_address(st_shndx
));
758 Sized_symbol
<size
>* res
;
761 Stringpool::Key name_key
;
762 name
= this->namepool_
.add(name
, true, &name_key
);
763 res
= this->add_from_object(relobj
, name
, name_key
, NULL
, 0,
766 this->force_local(res
);
770 Stringpool::Key name_key
;
771 name
= this->namepool_
.add_with_length(name
, namelen
, true,
773 Stringpool::Key ver_key
;
774 ver
= this->namepool_
.add(ver
, true, &ver_key
);
776 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
780 (*sympointers
)[i
] = res
;
784 // Add all the symbols in a dynamic object to the hash table.
786 template<int size
, bool big_endian
>
788 Symbol_table::add_from_dynobj(
789 Sized_dynobj
<size
, big_endian
>* dynobj
,
790 const unsigned char* syms
,
792 const char* sym_names
,
793 size_t sym_name_size
,
794 const unsigned char* versym
,
796 const std::vector
<const char*>* version_map
)
798 gold_assert(size
== dynobj
->target()->get_size());
799 gold_assert(size
== parameters
->target().get_size());
801 if (dynobj
->just_symbols())
803 gold_error(_("--just-symbols does not make sense with a shared object"));
807 if (versym
!= NULL
&& versym_size
/ 2 < count
)
809 dynobj
->error(_("too few symbol versions"));
813 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
815 // We keep a list of all STT_OBJECT symbols, so that we can resolve
816 // weak aliases. This is necessary because if the dynamic object
817 // provides the same variable under two names, one of which is a
818 // weak definition, and the regular object refers to the weak
819 // definition, we have to put both the weak definition and the
820 // strong definition into the dynamic symbol table. Given a weak
821 // definition, the only way that we can find the corresponding
822 // strong definition, if any, is to search the symbol table.
823 std::vector
<Sized_symbol
<size
>*> object_symbols
;
825 const unsigned char* p
= syms
;
826 const unsigned char* vs
= versym
;
827 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
829 elfcpp::Sym
<size
, big_endian
> sym(p
);
831 // Ignore symbols with local binding or that have
832 // internal or hidden visibility.
833 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
834 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
835 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
838 unsigned int st_name
= sym
.get_st_name();
839 if (st_name
>= sym_name_size
)
841 dynobj
->error(_("bad symbol name offset %u at %zu"),
846 const char* name
= sym_names
+ st_name
;
848 Sized_symbol
<size
>* res
;
852 Stringpool::Key name_key
;
853 name
= this->namepool_
.add(name
, true, &name_key
);
854 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
859 // Read the version information.
861 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
863 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
864 v
&= elfcpp::VERSYM_VERSION
;
866 // The Sun documentation says that V can be VER_NDX_LOCAL,
867 // or VER_NDX_GLOBAL, or a version index. The meaning of
868 // VER_NDX_LOCAL is defined as "Symbol has local scope."
869 // The old GNU linker will happily generate VER_NDX_LOCAL
870 // for an undefined symbol. I don't know what the Sun
871 // linker will generate.
873 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
874 && sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
876 // This symbol should not be visible outside the object.
880 // At this point we are definitely going to add this symbol.
881 Stringpool::Key name_key
;
882 name
= this->namepool_
.add(name
, true, &name_key
);
884 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
885 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
887 // This symbol does not have a version.
888 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
893 if (v
>= version_map
->size())
895 dynobj
->error(_("versym for symbol %zu out of range: %u"),
900 const char* version
= (*version_map
)[v
];
903 dynobj
->error(_("versym for symbol %zu has no name: %u"),
908 Stringpool::Key version_key
;
909 version
= this->namepool_
.add(version
, true, &version_key
);
911 // If this is an absolute symbol, and the version name
912 // and symbol name are the same, then this is the
913 // version definition symbol. These symbols exist to
914 // support using -u to pull in particular versions. We
915 // do not want to record a version for them.
916 if (sym
.get_st_shndx() == elfcpp::SHN_ABS
917 && name_key
== version_key
)
918 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
922 const bool def
= (!hidden
923 && (sym
.get_st_shndx()
924 != elfcpp::SHN_UNDEF
));
925 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
926 version_key
, def
, sym
, sym
);
931 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
932 && sym
.get_st_type() == elfcpp::STT_OBJECT
)
933 object_symbols
.push_back(res
);
936 this->record_weak_aliases(&object_symbols
);
939 // This is used to sort weak aliases. We sort them first by section
940 // index, then by offset, then by weak ahead of strong.
943 class Weak_alias_sorter
946 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
951 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
952 const Sized_symbol
<size
>* s2
) const
954 if (s1
->shndx() != s2
->shndx())
955 return s1
->shndx() < s2
->shndx();
956 if (s1
->value() != s2
->value())
957 return s1
->value() < s2
->value();
958 if (s1
->binding() != s2
->binding())
960 if (s1
->binding() == elfcpp::STB_WEAK
)
962 if (s2
->binding() == elfcpp::STB_WEAK
)
965 return std::string(s1
->name()) < std::string(s2
->name());
968 // SYMBOLS is a list of object symbols from a dynamic object. Look
969 // for any weak aliases, and record them so that if we add the weak
970 // alias to the dynamic symbol table, we also add the corresponding
975 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
977 // Sort the vector by section index, then by offset, then by weak
979 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
981 // Walk through the vector. For each weak definition, record
983 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
988 if ((*p
)->binding() != elfcpp::STB_WEAK
)
991 // Build a circular list of weak aliases. Each symbol points to
992 // the next one in the circular list.
994 Sized_symbol
<size
>* from_sym
= *p
;
995 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
996 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
998 if ((*q
)->shndx() != from_sym
->shndx()
999 || (*q
)->value() != from_sym
->value())
1002 this->weak_aliases_
[from_sym
] = *q
;
1003 from_sym
->set_has_alias();
1009 this->weak_aliases_
[from_sym
] = *p
;
1010 from_sym
->set_has_alias();
1017 // Create and return a specially defined symbol. If ONLY_IF_REF is
1018 // true, then only create the symbol if there is a reference to it.
1019 // If this does not return NULL, it sets *POLDSYM to the existing
1020 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1022 template<int size
, bool big_endian
>
1024 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1026 Sized_symbol
<size
>** poldsym
)
1029 Sized_symbol
<size
>* sym
;
1030 bool add_to_table
= false;
1031 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1033 // If the caller didn't give us a version, see if we get one from
1034 // the version script.
1035 if (*pversion
== NULL
)
1037 const std::string
& v(this->version_script_
.get_symbol_version(*pname
));
1039 *pversion
= v
.c_str();
1044 oldsym
= this->lookup(*pname
, *pversion
);
1045 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1048 *pname
= oldsym
->name();
1049 *pversion
= oldsym
->version();
1053 // Canonicalize NAME and VERSION.
1054 Stringpool::Key name_key
;
1055 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1057 Stringpool::Key version_key
= 0;
1058 if (*pversion
!= NULL
)
1059 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1061 Symbol
* const snull
= NULL
;
1062 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1063 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1069 // We already have a symbol table entry for NAME/VERSION.
1070 oldsym
= ins
.first
->second
;
1071 gold_assert(oldsym
!= NULL
);
1075 // We haven't seen this symbol before.
1076 gold_assert(ins
.first
->second
== NULL
);
1077 add_to_table
= true;
1078 add_loc
= ins
.first
;
1083 const Target
& target
= parameters
->target();
1084 if (!target
.has_make_symbol())
1085 sym
= new Sized_symbol
<size
>();
1088 gold_assert(target
.get_size() == size
);
1089 gold_assert(target
.is_big_endian() ? big_endian
: !big_endian
);
1090 typedef Sized_target
<size
, big_endian
> My_target
;
1091 const My_target
* sized_target
=
1092 static_cast<const My_target
*>(&target
);
1093 sym
= sized_target
->make_symbol();
1099 add_loc
->second
= sym
;
1101 gold_assert(oldsym
!= NULL
);
1103 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1108 // Define a symbol based on an Output_data.
1111 Symbol_table::define_in_output_data(const char* name
,
1112 const char* version
,
1117 elfcpp::STB binding
,
1118 elfcpp::STV visibility
,
1119 unsigned char nonvis
,
1120 bool offset_is_from_end
,
1123 if (parameters
->target().get_size() == 32)
1125 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1126 return this->do_define_in_output_data
<32>(name
, version
, od
,
1127 value
, symsize
, type
, binding
,
1135 else if (parameters
->target().get_size() == 64)
1137 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1138 return this->do_define_in_output_data
<64>(name
, version
, od
,
1139 value
, symsize
, type
, binding
,
1151 // Define a symbol in an Output_data, sized version.
1155 Symbol_table::do_define_in_output_data(
1157 const char* version
,
1159 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1160 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1162 elfcpp::STB binding
,
1163 elfcpp::STV visibility
,
1164 unsigned char nonvis
,
1165 bool offset_is_from_end
,
1168 Sized_symbol
<size
>* sym
;
1169 Sized_symbol
<size
>* oldsym
;
1171 if (parameters
->target().is_big_endian())
1173 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1174 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1175 only_if_ref
, &oldsym
);
1182 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1183 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1184 only_if_ref
, &oldsym
);
1193 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1194 sym
->init(name
, od
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1195 offset_is_from_end
);
1199 if (binding
== elfcpp::STB_LOCAL
1200 || this->version_script_
.symbol_is_local(name
))
1201 this->force_local(sym
);
1205 if (Symbol_table::should_override_with_special(oldsym
))
1206 this->override_with_special(oldsym
, sym
);
1211 // Define a symbol based on an Output_segment.
1214 Symbol_table::define_in_output_segment(const char* name
,
1215 const char* version
, Output_segment
* os
,
1219 elfcpp::STB binding
,
1220 elfcpp::STV visibility
,
1221 unsigned char nonvis
,
1222 Symbol::Segment_offset_base offset_base
,
1225 if (parameters
->target().get_size() == 32)
1227 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1228 return this->do_define_in_output_segment
<32>(name
, version
, os
,
1229 value
, symsize
, type
,
1230 binding
, visibility
, nonvis
,
1231 offset_base
, only_if_ref
);
1236 else if (parameters
->target().get_size() == 64)
1238 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1239 return this->do_define_in_output_segment
<64>(name
, version
, os
,
1240 value
, symsize
, type
,
1241 binding
, visibility
, nonvis
,
1242 offset_base
, only_if_ref
);
1251 // Define a symbol in an Output_segment, sized version.
1255 Symbol_table::do_define_in_output_segment(
1257 const char* version
,
1259 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1260 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1262 elfcpp::STB binding
,
1263 elfcpp::STV visibility
,
1264 unsigned char nonvis
,
1265 Symbol::Segment_offset_base offset_base
,
1268 Sized_symbol
<size
>* sym
;
1269 Sized_symbol
<size
>* oldsym
;
1271 if (parameters
->target().is_big_endian())
1273 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1274 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1275 only_if_ref
, &oldsym
);
1282 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1283 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1284 only_if_ref
, &oldsym
);
1293 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1294 sym
->init(name
, os
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1299 if (binding
== elfcpp::STB_LOCAL
1300 || this->version_script_
.symbol_is_local(name
))
1301 this->force_local(sym
);
1305 if (Symbol_table::should_override_with_special(oldsym
))
1306 this->override_with_special(oldsym
, sym
);
1311 // Define a special symbol with a constant value. It is a multiple
1312 // definition error if this symbol is already defined.
1315 Symbol_table::define_as_constant(const char* name
,
1316 const char* version
,
1320 elfcpp::STB binding
,
1321 elfcpp::STV visibility
,
1322 unsigned char nonvis
,
1324 bool force_override
)
1326 if (parameters
->target().get_size() == 32)
1328 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1329 return this->do_define_as_constant
<32>(name
, version
, value
,
1330 symsize
, type
, binding
,
1331 visibility
, nonvis
, only_if_ref
,
1337 else if (parameters
->target().get_size() == 64)
1339 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1340 return this->do_define_as_constant
<64>(name
, version
, value
,
1341 symsize
, type
, binding
,
1342 visibility
, nonvis
, only_if_ref
,
1352 // Define a symbol as a constant, sized version.
1356 Symbol_table::do_define_as_constant(
1358 const char* version
,
1359 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1360 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1362 elfcpp::STB binding
,
1363 elfcpp::STV visibility
,
1364 unsigned char nonvis
,
1366 bool force_override
)
1368 Sized_symbol
<size
>* sym
;
1369 Sized_symbol
<size
>* oldsym
;
1371 if (parameters
->target().is_big_endian())
1373 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1374 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1375 only_if_ref
, &oldsym
);
1382 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1383 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1384 only_if_ref
, &oldsym
);
1393 gold_assert(version
== NULL
|| version
== name
|| oldsym
!= NULL
);
1394 sym
->init(name
, value
, symsize
, type
, binding
, visibility
, nonvis
);
1398 if (binding
== elfcpp::STB_LOCAL
1399 || this->version_script_
.symbol_is_local(name
))
1400 this->force_local(sym
);
1404 if (force_override
|| Symbol_table::should_override_with_special(oldsym
))
1405 this->override_with_special(oldsym
, sym
);
1410 // Define a set of symbols in output sections.
1413 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1414 const Define_symbol_in_section
* p
,
1417 for (int i
= 0; i
< count
; ++i
, ++p
)
1419 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1421 this->define_in_output_data(p
->name
, NULL
, os
, p
->value
,
1422 p
->size
, p
->type
, p
->binding
,
1423 p
->visibility
, p
->nonvis
,
1424 p
->offset_is_from_end
,
1425 only_if_ref
|| p
->only_if_ref
);
1427 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1428 p
->binding
, p
->visibility
, p
->nonvis
,
1429 only_if_ref
|| p
->only_if_ref
,
1434 // Define a set of symbols in output segments.
1437 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1438 const Define_symbol_in_segment
* p
,
1441 for (int i
= 0; i
< count
; ++i
, ++p
)
1443 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1444 p
->segment_flags_set
,
1445 p
->segment_flags_clear
);
1447 this->define_in_output_segment(p
->name
, NULL
, os
, p
->value
,
1448 p
->size
, p
->type
, p
->binding
,
1449 p
->visibility
, p
->nonvis
,
1451 only_if_ref
|| p
->only_if_ref
);
1453 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1454 p
->binding
, p
->visibility
, p
->nonvis
,
1455 only_if_ref
|| p
->only_if_ref
,
1460 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1461 // symbol should be defined--typically a .dyn.bss section. VALUE is
1462 // the offset within POSD.
1466 Symbol_table::define_with_copy_reloc(
1467 Sized_symbol
<size
>* csym
,
1469 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1471 gold_assert(csym
->is_from_dynobj());
1472 gold_assert(!csym
->is_copied_from_dynobj());
1473 Object
* object
= csym
->object();
1474 gold_assert(object
->is_dynamic());
1475 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1477 // Our copied variable has to override any variable in a shared
1479 elfcpp::STB binding
= csym
->binding();
1480 if (binding
== elfcpp::STB_WEAK
)
1481 binding
= elfcpp::STB_GLOBAL
;
1483 this->define_in_output_data(csym
->name(), csym
->version(),
1484 posd
, value
, csym
->symsize(),
1485 csym
->type(), binding
,
1486 csym
->visibility(), csym
->nonvis(),
1489 csym
->set_is_copied_from_dynobj();
1490 csym
->set_needs_dynsym_entry();
1492 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1494 // We have now defined all aliases, but we have not entered them all
1495 // in the copied_symbol_dynobjs_ map.
1496 if (csym
->has_alias())
1501 sym
= this->weak_aliases_
[sym
];
1504 gold_assert(sym
->output_data() == posd
);
1506 sym
->set_is_copied_from_dynobj();
1507 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1512 // SYM is defined using a COPY reloc. Return the dynamic object where
1513 // the original definition was found.
1516 Symbol_table::get_copy_source(const Symbol
* sym
) const
1518 gold_assert(sym
->is_copied_from_dynobj());
1519 Copied_symbol_dynobjs::const_iterator p
=
1520 this->copied_symbol_dynobjs_
.find(sym
);
1521 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1525 // Set the dynamic symbol indexes. INDEX is the index of the first
1526 // global dynamic symbol. Pointers to the symbols are stored into the
1527 // vector SYMS. The names are added to DYNPOOL. This returns an
1528 // updated dynamic symbol index.
1531 Symbol_table::set_dynsym_indexes(unsigned int index
,
1532 std::vector
<Symbol
*>* syms
,
1533 Stringpool
* dynpool
,
1536 for (Symbol_table_type::iterator p
= this->table_
.begin();
1537 p
!= this->table_
.end();
1540 Symbol
* sym
= p
->second
;
1542 // Note that SYM may already have a dynamic symbol index, since
1543 // some symbols appear more than once in the symbol table, with
1544 // and without a version.
1546 if (!sym
->should_add_dynsym_entry())
1547 sym
->set_dynsym_index(-1U);
1548 else if (!sym
->has_dynsym_index())
1550 sym
->set_dynsym_index(index
);
1552 syms
->push_back(sym
);
1553 dynpool
->add(sym
->name(), false, NULL
);
1555 // Record any version information.
1556 if (sym
->version() != NULL
)
1557 versions
->record_version(this, dynpool
, sym
);
1561 // Finish up the versions. In some cases this may add new dynamic
1563 index
= versions
->finalize(this, index
, syms
);
1568 // Set the final values for all the symbols. The index of the first
1569 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1570 // file offset OFF. Add their names to POOL. Return the new file
1571 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1574 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
1575 size_t dyncount
, Stringpool
* pool
,
1576 unsigned int *plocal_symcount
)
1580 gold_assert(*plocal_symcount
!= 0);
1581 this->first_global_index_
= *plocal_symcount
;
1583 this->dynamic_offset_
= dynoff
;
1584 this->first_dynamic_global_index_
= dyn_global_index
;
1585 this->dynamic_count_
= dyncount
;
1587 if (parameters
->target().get_size() == 32)
1589 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1590 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
1595 else if (parameters
->target().get_size() == 64)
1597 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1598 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
1606 // Now that we have the final symbol table, we can reliably note
1607 // which symbols should get warnings.
1608 this->warnings_
.note_warnings(this);
1613 // SYM is going into the symbol table at *PINDEX. Add the name to
1614 // POOL, update *PINDEX and *POFF.
1618 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
1619 unsigned int* pindex
, off_t
* poff
)
1621 sym
->set_symtab_index(*pindex
);
1622 pool
->add(sym
->name(), false, NULL
);
1624 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
1627 // Set the final value for all the symbols. This is called after
1628 // Layout::finalize, so all the output sections have their final
1633 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
1634 unsigned int* plocal_symcount
)
1636 off
= align_address(off
, size
>> 3);
1637 this->offset_
= off
;
1639 unsigned int index
= *plocal_symcount
;
1640 const unsigned int orig_index
= index
;
1642 // First do all the symbols which have been forced to be local, as
1643 // they must appear before all global symbols.
1644 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
1645 p
!= this->forced_locals_
.end();
1649 gold_assert(sym
->is_forced_local());
1650 if (this->sized_finalize_symbol
<size
>(sym
))
1652 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1657 // Now do all the remaining symbols.
1658 for (Symbol_table_type::iterator p
= this->table_
.begin();
1659 p
!= this->table_
.end();
1662 Symbol
* sym
= p
->second
;
1663 if (this->sized_finalize_symbol
<size
>(sym
))
1664 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1667 this->output_count_
= index
- orig_index
;
1672 // Finalize the symbol SYM. This returns true if the symbol should be
1673 // added to the symbol table, false otherwise.
1677 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
1679 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
1681 // The default version of a symbol may appear twice in the symbol
1682 // table. We only need to finalize it once.
1683 if (sym
->has_symtab_index())
1688 gold_assert(!sym
->has_symtab_index());
1689 sym
->set_symtab_index(-1U);
1690 gold_assert(sym
->dynsym_index() == -1U);
1694 typename Sized_symbol
<size
>::Value_type value
;
1696 switch (sym
->source())
1698 case Symbol::FROM_OBJECT
:
1700 unsigned int shndx
= sym
->shndx();
1702 // FIXME: We need some target specific support here.
1703 if (shndx
>= elfcpp::SHN_LORESERVE
1704 && shndx
!= elfcpp::SHN_ABS
1705 && shndx
!= elfcpp::SHN_COMMON
)
1707 gold_error(_("%s: unsupported symbol section 0x%x"),
1708 sym
->demangled_name().c_str(), shndx
);
1709 shndx
= elfcpp::SHN_UNDEF
;
1712 Object
* symobj
= sym
->object();
1713 if (symobj
->is_dynamic())
1716 shndx
= elfcpp::SHN_UNDEF
;
1718 else if (shndx
== elfcpp::SHN_UNDEF
)
1720 else if (shndx
== elfcpp::SHN_ABS
|| shndx
== elfcpp::SHN_COMMON
)
1721 value
= sym
->value();
1724 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1725 section_offset_type secoff
;
1726 Output_section
* os
= relobj
->output_section(shndx
, &secoff
);
1730 sym
->set_symtab_index(-1U);
1731 gold_assert(sym
->dynsym_index() == -1U);
1735 if (sym
->type() == elfcpp::STT_TLS
)
1736 value
= sym
->value() + os
->tls_offset() + secoff
;
1738 value
= sym
->value() + os
->address() + secoff
;
1743 case Symbol::IN_OUTPUT_DATA
:
1745 Output_data
* od
= sym
->output_data();
1746 value
= sym
->value() + od
->address();
1747 if (sym
->offset_is_from_end())
1748 value
+= od
->data_size();
1752 case Symbol::IN_OUTPUT_SEGMENT
:
1754 Output_segment
* os
= sym
->output_segment();
1755 value
= sym
->value() + os
->vaddr();
1756 switch (sym
->offset_base())
1758 case Symbol::SEGMENT_START
:
1760 case Symbol::SEGMENT_END
:
1761 value
+= os
->memsz();
1763 case Symbol::SEGMENT_BSS
:
1764 value
+= os
->filesz();
1772 case Symbol::CONSTANT
:
1773 value
= sym
->value();
1780 sym
->set_value(value
);
1782 if (parameters
->options().strip_all())
1784 sym
->set_symtab_index(-1U);
1791 // Write out the global symbols.
1794 Symbol_table::write_globals(const Input_objects
* input_objects
,
1795 const Stringpool
* sympool
,
1796 const Stringpool
* dynpool
, Output_file
* of
) const
1798 switch (parameters
->size_and_endianness())
1800 #ifdef HAVE_TARGET_32_LITTLE
1801 case Parameters::TARGET_32_LITTLE
:
1802 this->sized_write_globals
<32, false>(input_objects
, sympool
,
1806 #ifdef HAVE_TARGET_32_BIG
1807 case Parameters::TARGET_32_BIG
:
1808 this->sized_write_globals
<32, true>(input_objects
, sympool
,
1812 #ifdef HAVE_TARGET_64_LITTLE
1813 case Parameters::TARGET_64_LITTLE
:
1814 this->sized_write_globals
<64, false>(input_objects
, sympool
,
1818 #ifdef HAVE_TARGET_64_BIG
1819 case Parameters::TARGET_64_BIG
:
1820 this->sized_write_globals
<64, true>(input_objects
, sympool
,
1829 // Write out the global symbols.
1831 template<int size
, bool big_endian
>
1833 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
1834 const Stringpool
* sympool
,
1835 const Stringpool
* dynpool
,
1836 Output_file
* of
) const
1838 const Target
& target
= parameters
->target();
1840 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1842 const unsigned int output_count
= this->output_count_
;
1843 const section_size_type oview_size
= output_count
* sym_size
;
1844 const unsigned int first_global_index
= this->first_global_index_
;
1845 unsigned char* psyms
;
1846 if (this->offset_
== 0 || output_count
== 0)
1849 psyms
= of
->get_output_view(this->offset_
, oview_size
);
1851 const unsigned int dynamic_count
= this->dynamic_count_
;
1852 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
1853 const unsigned int first_dynamic_global_index
=
1854 this->first_dynamic_global_index_
;
1855 unsigned char* dynamic_view
;
1856 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
1857 dynamic_view
= NULL
;
1859 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
1861 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1862 p
!= this->table_
.end();
1865 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1867 // Possibly warn about unresolved symbols in shared libraries.
1868 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
1870 unsigned int sym_index
= sym
->symtab_index();
1871 unsigned int dynsym_index
;
1872 if (dynamic_view
== NULL
)
1875 dynsym_index
= sym
->dynsym_index();
1877 if (sym_index
== -1U && dynsym_index
== -1U)
1879 // This symbol is not included in the output file.
1884 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
1885 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
1886 switch (sym
->source())
1888 case Symbol::FROM_OBJECT
:
1890 unsigned int in_shndx
= sym
->shndx();
1892 // FIXME: We need some target specific support here.
1893 if (in_shndx
>= elfcpp::SHN_LORESERVE
1894 && in_shndx
!= elfcpp::SHN_ABS
1895 && in_shndx
!= elfcpp::SHN_COMMON
)
1897 gold_error(_("%s: unsupported symbol section 0x%x"),
1898 sym
->demangled_name().c_str(), in_shndx
);
1903 Object
* symobj
= sym
->object();
1904 if (symobj
->is_dynamic())
1906 if (sym
->needs_dynsym_value())
1907 dynsym_value
= target
.dynsym_value(sym
);
1908 shndx
= elfcpp::SHN_UNDEF
;
1910 else if (in_shndx
== elfcpp::SHN_UNDEF
1911 || in_shndx
== elfcpp::SHN_ABS
1912 || in_shndx
== elfcpp::SHN_COMMON
)
1916 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1917 section_offset_type secoff
;
1918 Output_section
* os
= relobj
->output_section(in_shndx
,
1920 gold_assert(os
!= NULL
);
1921 shndx
= os
->out_shndx();
1923 // In object files symbol values are section
1925 if (parameters
->options().relocatable())
1926 sym_value
-= os
->address();
1932 case Symbol::IN_OUTPUT_DATA
:
1933 shndx
= sym
->output_data()->out_shndx();
1936 case Symbol::IN_OUTPUT_SEGMENT
:
1937 shndx
= elfcpp::SHN_ABS
;
1940 case Symbol::CONSTANT
:
1941 shndx
= elfcpp::SHN_ABS
;
1948 if (sym_index
!= -1U)
1950 sym_index
-= first_global_index
;
1951 gold_assert(sym_index
< output_count
);
1952 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
1953 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
1957 if (dynsym_index
!= -1U)
1959 dynsym_index
-= first_dynamic_global_index
;
1960 gold_assert(dynsym_index
< dynamic_count
);
1961 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
1962 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
1967 of
->write_output_view(this->offset_
, oview_size
, psyms
);
1968 if (dynamic_view
!= NULL
)
1969 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
1972 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1973 // strtab holding the name.
1975 template<int size
, bool big_endian
>
1977 Symbol_table::sized_write_symbol(
1978 Sized_symbol
<size
>* sym
,
1979 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1981 const Stringpool
* pool
,
1982 unsigned char* p
) const
1984 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
1985 osym
.put_st_name(pool
->get_offset(sym
->name()));
1986 osym
.put_st_value(value
);
1987 osym
.put_st_size(sym
->symsize());
1988 // A version script may have overridden the default binding.
1989 if (sym
->is_forced_local())
1990 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, sym
->type()));
1992 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
1993 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
1994 osym
.put_st_shndx(shndx
);
1997 // Check for unresolved symbols in shared libraries. This is
1998 // controlled by the --allow-shlib-undefined option.
2000 // We only warn about libraries for which we have seen all the
2001 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2002 // which were not seen in this link. If we didn't see a DT_NEEDED
2003 // entry, we aren't going to be able to reliably report whether the
2004 // symbol is undefined.
2006 // We also don't warn about libraries found in the system library
2007 // directory (the directory were we find libc.so); we assume that
2008 // those libraries are OK. This heuristic avoids problems in
2009 // GNU/Linux, in which -ldl can have undefined references satisfied by
2013 Symbol_table::warn_about_undefined_dynobj_symbol(
2014 const Input_objects
* input_objects
,
2017 if (sym
->source() == Symbol::FROM_OBJECT
2018 && sym
->object()->is_dynamic()
2019 && sym
->shndx() == elfcpp::SHN_UNDEF
2020 && sym
->binding() != elfcpp::STB_WEAK
2021 && !parameters
->options().allow_shlib_undefined()
2022 && !parameters
->target().is_defined_by_abi(sym
)
2023 && !input_objects
->found_in_system_library_directory(sym
->object()))
2025 // A very ugly cast.
2026 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
2027 if (!dynobj
->has_unknown_needed_entries())
2028 gold_error(_("%s: undefined reference to '%s'"),
2029 sym
->object()->name().c_str(),
2030 sym
->demangled_name().c_str());
2034 // Write out a section symbol. Return the update offset.
2037 Symbol_table::write_section_symbol(const Output_section
*os
,
2041 switch (parameters
->size_and_endianness())
2043 #ifdef HAVE_TARGET_32_LITTLE
2044 case Parameters::TARGET_32_LITTLE
:
2045 this->sized_write_section_symbol
<32, false>(os
, of
, offset
);
2048 #ifdef HAVE_TARGET_32_BIG
2049 case Parameters::TARGET_32_BIG
:
2050 this->sized_write_section_symbol
<32, true>(os
, of
, offset
);
2053 #ifdef HAVE_TARGET_64_LITTLE
2054 case Parameters::TARGET_64_LITTLE
:
2055 this->sized_write_section_symbol
<64, false>(os
, of
, offset
);
2058 #ifdef HAVE_TARGET_64_BIG
2059 case Parameters::TARGET_64_BIG
:
2060 this->sized_write_section_symbol
<64, true>(os
, of
, offset
);
2068 // Write out a section symbol, specialized for size and endianness.
2070 template<int size
, bool big_endian
>
2072 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
2076 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2078 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
2080 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
2081 osym
.put_st_name(0);
2082 osym
.put_st_value(os
->address());
2083 osym
.put_st_size(0);
2084 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
2085 elfcpp::STT_SECTION
));
2086 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
2087 osym
.put_st_shndx(os
->out_shndx());
2089 of
->write_output_view(offset
, sym_size
, pov
);
2092 // Print statistical information to stderr. This is used for --stats.
2095 Symbol_table::print_stats() const
2097 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2098 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2099 program_name
, this->table_
.size(), this->table_
.bucket_count());
2101 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
2102 program_name
, this->table_
.size());
2104 this->namepool_
.print_stats("symbol table stringpool");
2107 // We check for ODR violations by looking for symbols with the same
2108 // name for which the debugging information reports that they were
2109 // defined in different source locations. When comparing the source
2110 // location, we consider instances with the same base filename and
2111 // line number to be the same. This is because different object
2112 // files/shared libraries can include the same header file using
2113 // different paths, and we don't want to report an ODR violation in
2116 // This struct is used to compare line information, as returned by
2117 // Dwarf_line_info::one_addr2line. It implements a < comparison
2118 // operator used with std::set.
2120 struct Odr_violation_compare
2123 operator()(const std::string
& s1
, const std::string
& s2
) const
2125 std::string::size_type pos1
= s1
.rfind('/');
2126 std::string::size_type pos2
= s2
.rfind('/');
2127 if (pos1
== std::string::npos
2128 || pos2
== std::string::npos
)
2130 return s1
.compare(pos1
, std::string::npos
,
2131 s2
, pos2
, std::string::npos
) < 0;
2135 // Check candidate_odr_violations_ to find symbols with the same name
2136 // but apparently different definitions (different source-file/line-no).
2139 Symbol_table::detect_odr_violations(const Task
* task
,
2140 const char* output_file_name
) const
2142 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
2143 it
!= candidate_odr_violations_
.end();
2146 const char* symbol_name
= it
->first
;
2147 // We use a sorted set so the output is deterministic.
2148 std::set
<std::string
, Odr_violation_compare
> line_nums
;
2150 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
2151 locs
= it
->second
.begin();
2152 locs
!= it
->second
.end();
2155 // We need to lock the object in order to read it. This
2156 // means that we have to run in a singleton Task. If we
2157 // want to run this in a general Task for better
2158 // performance, we will need one Task for object, plus
2159 // appropriate locking to ensure that we don't conflict with
2160 // other uses of the object.
2161 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2162 std::string lineno
= Dwarf_line_info::one_addr2line(
2163 locs
->object
, locs
->shndx
, locs
->offset
);
2164 if (!lineno
.empty())
2165 line_nums
.insert(lineno
);
2168 if (line_nums
.size() > 1)
2170 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2171 "places (possible ODR violation):"),
2172 output_file_name
, demangle(symbol_name
).c_str());
2173 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2174 it2
!= line_nums
.end();
2176 fprintf(stderr
, " %s\n", it2
->c_str());
2181 // Warnings functions.
2183 // Add a new warning.
2186 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2187 const std::string
& warning
)
2189 name
= symtab
->canonicalize_name(name
);
2190 this->warnings_
[name
].set(obj
, warning
);
2193 // Look through the warnings and mark the symbols for which we should
2194 // warn. This is called during Layout::finalize when we know the
2195 // sources for all the symbols.
2198 Warnings::note_warnings(Symbol_table
* symtab
)
2200 for (Warning_table::iterator p
= this->warnings_
.begin();
2201 p
!= this->warnings_
.end();
2204 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2206 && sym
->source() == Symbol::FROM_OBJECT
2207 && sym
->object() == p
->second
.object
)
2208 sym
->set_has_warning();
2212 // Issue a warning. This is called when we see a relocation against a
2213 // symbol for which has a warning.
2215 template<int size
, bool big_endian
>
2217 Warnings::issue_warning(const Symbol
* sym
,
2218 const Relocate_info
<size
, big_endian
>* relinfo
,
2219 size_t relnum
, off_t reloffset
) const
2221 gold_assert(sym
->has_warning());
2222 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2223 gold_assert(p
!= this->warnings_
.end());
2224 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2225 "%s", p
->second
.text
.c_str());
2228 // Instantiate the templates we need. We could use the configure
2229 // script to restrict this to only the ones needed for implemented
2232 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2235 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2238 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2241 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2244 #ifdef HAVE_TARGET_32_LITTLE
2247 Symbol_table::add_from_relobj
<32, false>(
2248 Sized_relobj
<32, false>* relobj
,
2249 const unsigned char* syms
,
2251 const char* sym_names
,
2252 size_t sym_name_size
,
2253 Sized_relobj
<32, true>::Symbols
* sympointers
);
2256 #ifdef HAVE_TARGET_32_BIG
2259 Symbol_table::add_from_relobj
<32, true>(
2260 Sized_relobj
<32, true>* relobj
,
2261 const unsigned char* syms
,
2263 const char* sym_names
,
2264 size_t sym_name_size
,
2265 Sized_relobj
<32, false>::Symbols
* sympointers
);
2268 #ifdef HAVE_TARGET_64_LITTLE
2271 Symbol_table::add_from_relobj
<64, false>(
2272 Sized_relobj
<64, false>* relobj
,
2273 const unsigned char* syms
,
2275 const char* sym_names
,
2276 size_t sym_name_size
,
2277 Sized_relobj
<64, true>::Symbols
* sympointers
);
2280 #ifdef HAVE_TARGET_64_BIG
2283 Symbol_table::add_from_relobj
<64, true>(
2284 Sized_relobj
<64, true>* relobj
,
2285 const unsigned char* syms
,
2287 const char* sym_names
,
2288 size_t sym_name_size
,
2289 Sized_relobj
<64, false>::Symbols
* sympointers
);
2292 #ifdef HAVE_TARGET_32_LITTLE
2295 Symbol_table::add_from_dynobj
<32, false>(
2296 Sized_dynobj
<32, false>* dynobj
,
2297 const unsigned char* syms
,
2299 const char* sym_names
,
2300 size_t sym_name_size
,
2301 const unsigned char* versym
,
2303 const std::vector
<const char*>* version_map
);
2306 #ifdef HAVE_TARGET_32_BIG
2309 Symbol_table::add_from_dynobj
<32, true>(
2310 Sized_dynobj
<32, true>* dynobj
,
2311 const unsigned char* syms
,
2313 const char* sym_names
,
2314 size_t sym_name_size
,
2315 const unsigned char* versym
,
2317 const std::vector
<const char*>* version_map
);
2320 #ifdef HAVE_TARGET_64_LITTLE
2323 Symbol_table::add_from_dynobj
<64, false>(
2324 Sized_dynobj
<64, false>* dynobj
,
2325 const unsigned char* syms
,
2327 const char* sym_names
,
2328 size_t sym_name_size
,
2329 const unsigned char* versym
,
2331 const std::vector
<const char*>* version_map
);
2334 #ifdef HAVE_TARGET_64_BIG
2337 Symbol_table::add_from_dynobj
<64, true>(
2338 Sized_dynobj
<64, true>* dynobj
,
2339 const unsigned char* syms
,
2341 const char* sym_names
,
2342 size_t sym_name_size
,
2343 const unsigned char* versym
,
2345 const std::vector
<const char*>* version_map
);
2348 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2351 Symbol_table::define_with_copy_reloc
<32>(
2352 Sized_symbol
<32>* sym
,
2354 elfcpp::Elf_types
<32>::Elf_Addr value
);
2357 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2360 Symbol_table::define_with_copy_reloc
<64>(
2361 Sized_symbol
<64>* sym
,
2363 elfcpp::Elf_types
<64>::Elf_Addr value
);
2366 #ifdef HAVE_TARGET_32_LITTLE
2369 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
2370 const Relocate_info
<32, false>* relinfo
,
2371 size_t relnum
, off_t reloffset
) const;
2374 #ifdef HAVE_TARGET_32_BIG
2377 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
2378 const Relocate_info
<32, true>* relinfo
,
2379 size_t relnum
, off_t reloffset
) const;
2382 #ifdef HAVE_TARGET_64_LITTLE
2385 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
2386 const Relocate_info
<64, false>* relinfo
,
2387 size_t relnum
, off_t reloffset
) const;
2390 #ifdef HAVE_TARGET_64_BIG
2393 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
2394 const Relocate_info
<64, true>* relinfo
,
2395 size_t relnum
, off_t reloffset
) const;
2398 } // End namespace gold.