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.
34 #include "dwarf_reader.h"
38 #include "workqueue.h"
46 // Initialize fields in Symbol. This initializes everything except u_
50 Symbol::init_fields(const char* name
, const char* version
,
51 elfcpp::STT type
, elfcpp::STB binding
,
52 elfcpp::STV visibility
, unsigned char nonvis
)
55 this->version_
= version
;
56 this->symtab_index_
= 0;
57 this->dynsym_index_
= 0;
58 this->got_offsets_
.init();
59 this->plt_offset_
= 0;
61 this->binding_
= binding
;
62 this->visibility_
= visibility
;
63 this->nonvis_
= nonvis
;
64 this->is_target_special_
= false;
65 this->is_def_
= false;
66 this->is_forwarder_
= false;
67 this->has_alias_
= false;
68 this->needs_dynsym_entry_
= false;
69 this->in_reg_
= false;
70 this->in_dyn_
= false;
71 this->has_plt_offset_
= false;
72 this->has_warning_
= false;
73 this->is_copied_from_dynobj_
= false;
74 this->is_forced_local_
= false;
77 // Return the demangled version of the symbol's name, but only
78 // if the --demangle flag was set.
81 demangle(const char* name
)
83 if (!parameters
->options().do_demangle())
86 // cplus_demangle allocates memory for the result it returns,
87 // and returns NULL if the name is already demangled.
88 char* demangled_name
= cplus_demangle(name
, DMGL_ANSI
| DMGL_PARAMS
);
89 if (demangled_name
== NULL
)
92 std::string
retval(demangled_name
);
98 Symbol::demangled_name() const
100 return demangle(this->name());
103 // Initialize the fields in the base class Symbol for SYM in OBJECT.
105 template<int size
, bool big_endian
>
107 Symbol::init_base(const char* name
, const char* version
, Object
* object
,
108 const elfcpp::Sym
<size
, big_endian
>& sym
)
110 this->init_fields(name
, version
, sym
.get_st_type(), sym
.get_st_bind(),
111 sym
.get_st_visibility(), sym
.get_st_nonvis());
112 this->u_
.from_object
.object
= object
;
113 // FIXME: Handle SHN_XINDEX.
114 this->u_
.from_object
.shndx
= sym
.get_st_shndx();
115 this->source_
= FROM_OBJECT
;
116 this->in_reg_
= !object
->is_dynamic();
117 this->in_dyn_
= object
->is_dynamic();
120 // Initialize the fields in the base class Symbol for a symbol defined
121 // in an Output_data.
124 Symbol::init_base(const char* name
, Output_data
* od
, elfcpp::STT type
,
125 elfcpp::STB binding
, elfcpp::STV visibility
,
126 unsigned char nonvis
, bool offset_is_from_end
)
128 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
129 this->u_
.in_output_data
.output_data
= od
;
130 this->u_
.in_output_data
.offset_is_from_end
= offset_is_from_end
;
131 this->source_
= IN_OUTPUT_DATA
;
132 this->in_reg_
= true;
135 // Initialize the fields in the base class Symbol for a symbol defined
136 // in an Output_segment.
139 Symbol::init_base(const char* name
, Output_segment
* os
, elfcpp::STT type
,
140 elfcpp::STB binding
, elfcpp::STV visibility
,
141 unsigned char nonvis
, Segment_offset_base offset_base
)
143 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
144 this->u_
.in_output_segment
.output_segment
= os
;
145 this->u_
.in_output_segment
.offset_base
= offset_base
;
146 this->source_
= IN_OUTPUT_SEGMENT
;
147 this->in_reg_
= true;
150 // Initialize the fields in the base class Symbol for a symbol defined
154 Symbol::init_base(const char* name
, elfcpp::STT type
,
155 elfcpp::STB binding
, elfcpp::STV visibility
,
156 unsigned char nonvis
)
158 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
159 this->source_
= CONSTANT
;
160 this->in_reg_
= true;
163 // Allocate a common symbol in the base.
166 Symbol::allocate_base_common(Output_data
* od
)
168 gold_assert(this->is_common());
169 this->source_
= IN_OUTPUT_DATA
;
170 this->u_
.in_output_data
.output_data
= od
;
171 this->u_
.in_output_data
.offset_is_from_end
= false;
174 // Initialize the fields in Sized_symbol for SYM in OBJECT.
177 template<bool big_endian
>
179 Sized_symbol
<size
>::init(const char* name
, const char* version
, Object
* object
,
180 const elfcpp::Sym
<size
, big_endian
>& sym
)
182 this->init_base(name
, version
, object
, sym
);
183 this->value_
= sym
.get_st_value();
184 this->symsize_
= sym
.get_st_size();
187 // Initialize the fields in Sized_symbol for a symbol defined in an
192 Sized_symbol
<size
>::init(const char* name
, Output_data
* od
,
193 Value_type value
, Size_type symsize
,
194 elfcpp::STT type
, elfcpp::STB binding
,
195 elfcpp::STV visibility
, unsigned char nonvis
,
196 bool offset_is_from_end
)
198 this->init_base(name
, od
, type
, binding
, visibility
, nonvis
,
200 this->value_
= value
;
201 this->symsize_
= symsize
;
204 // Initialize the fields in Sized_symbol for a symbol defined in an
209 Sized_symbol
<size
>::init(const char* name
, Output_segment
* os
,
210 Value_type value
, Size_type symsize
,
211 elfcpp::STT type
, elfcpp::STB binding
,
212 elfcpp::STV visibility
, unsigned char nonvis
,
213 Segment_offset_base offset_base
)
215 this->init_base(name
, os
, type
, binding
, visibility
, nonvis
, offset_base
);
216 this->value_
= value
;
217 this->symsize_
= symsize
;
220 // Initialize the fields in Sized_symbol for a symbol defined as a
225 Sized_symbol
<size
>::init(const char* name
, Value_type value
, Size_type symsize
,
226 elfcpp::STT type
, elfcpp::STB binding
,
227 elfcpp::STV visibility
, unsigned char nonvis
)
229 this->init_base(name
, type
, binding
, visibility
, nonvis
);
230 this->value_
= value
;
231 this->symsize_
= symsize
;
234 // Allocate a common symbol.
238 Sized_symbol
<size
>::allocate_common(Output_data
* od
, Value_type value
)
240 this->allocate_base_common(od
);
241 this->value_
= value
;
244 // Return true if this symbol should be added to the dynamic symbol
248 Symbol::should_add_dynsym_entry() const
250 // If the symbol is used by a dynamic relocation, we need to add it.
251 if (this->needs_dynsym_entry())
254 // If the symbol was forced local in a version script, do not add it.
255 if (this->is_forced_local())
258 // If exporting all symbols or building a shared library,
259 // and the symbol is defined in a regular object and is
260 // externally visible, we need to add it.
261 if ((parameters
->options().export_dynamic() || parameters
->options().shared())
262 && !this->is_from_dynobj()
263 && this->is_externally_visible())
269 // Return true if the final value of this symbol is known at link
273 Symbol::final_value_is_known() const
275 // If we are not generating an executable, then no final values are
276 // known, since they will change at runtime.
277 if (parameters
->options().shared() || parameters
->options().relocatable())
280 // If the symbol is not from an object file, then it is defined, and
282 if (this->source_
!= FROM_OBJECT
)
285 // If the symbol is from a dynamic object, then the final value is
287 if (this->object()->is_dynamic())
290 // If the symbol is not undefined (it is defined or common), then
291 // the final value is known.
292 if (!this->is_undefined())
295 // If the symbol is undefined, then whether the final value is known
296 // depends on whether we are doing a static link. If we are doing a
297 // dynamic link, then the final value could be filled in at runtime.
298 // This could reasonably be the case for a weak undefined symbol.
299 return parameters
->doing_static_link();
302 // Return the output section where this symbol is defined.
305 Symbol::output_section() const
307 switch (this->source_
)
311 unsigned int shndx
= this->u_
.from_object
.shndx
;
312 if (shndx
!= elfcpp::SHN_UNDEF
&& shndx
< elfcpp::SHN_LORESERVE
)
314 gold_assert(!this->u_
.from_object
.object
->is_dynamic());
315 Relobj
* relobj
= static_cast<Relobj
*>(this->u_
.from_object
.object
);
316 section_offset_type dummy
;
317 return relobj
->output_section(shndx
, &dummy
);
323 return this->u_
.in_output_data
.output_data
->output_section();
325 case IN_OUTPUT_SEGMENT
:
334 // Set the symbol's output section. This is used for symbols defined
335 // in scripts. This should only be called after the symbol table has
339 Symbol::set_output_section(Output_section
* os
)
341 switch (this->source_
)
345 gold_assert(this->output_section() == os
);
348 this->source_
= IN_OUTPUT_DATA
;
349 this->u_
.in_output_data
.output_data
= os
;
350 this->u_
.in_output_data
.offset_is_from_end
= false;
352 case IN_OUTPUT_SEGMENT
:
358 // Class Symbol_table.
360 Symbol_table::Symbol_table(unsigned int count
,
361 const Version_script_info
& version_script
)
362 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
363 forwarders_(), commons_(), forced_locals_(), warnings_(),
364 version_script_(version_script
)
366 namepool_
.reserve(count
);
369 Symbol_table::~Symbol_table()
373 // The hash function. The key values are Stringpool keys.
376 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key
& key
) const
378 return key
.first
^ key
.second
;
381 // The symbol table key equality function. This is called with
385 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
386 const Symbol_table_key
& k2
) const
388 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
391 // Make TO a symbol which forwards to FROM.
394 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
396 gold_assert(from
!= to
);
397 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
398 this->forwarders_
[from
] = to
;
399 from
->set_forwarder();
402 // Resolve the forwards from FROM, returning the real symbol.
405 Symbol_table::resolve_forwards(const Symbol
* from
) const
407 gold_assert(from
->is_forwarder());
408 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
409 this->forwarders_
.find(from
);
410 gold_assert(p
!= this->forwarders_
.end());
414 // Look up a symbol by name.
417 Symbol_table::lookup(const char* name
, const char* version
) const
419 Stringpool::Key name_key
;
420 name
= this->namepool_
.find(name
, &name_key
);
424 Stringpool::Key version_key
= 0;
427 version
= this->namepool_
.find(version
, &version_key
);
432 Symbol_table_key
key(name_key
, version_key
);
433 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
434 if (p
== this->table_
.end())
439 // Resolve a Symbol with another Symbol. This is only used in the
440 // unusual case where there are references to both an unversioned
441 // symbol and a symbol with a version, and we then discover that that
442 // version is the default version. Because this is unusual, we do
443 // this the slow way, by converting back to an ELF symbol.
445 template<int size
, bool big_endian
>
447 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
,
450 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
451 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
452 // We don't bother to set the st_name field.
453 esym
.put_st_value(from
->value());
454 esym
.put_st_size(from
->symsize());
455 esym
.put_st_info(from
->binding(), from
->type());
456 esym
.put_st_other(from
->visibility(), from
->nonvis());
457 esym
.put_st_shndx(from
->shndx());
458 this->resolve(to
, esym
.sym(), esym
.sym(), from
->object(), version
);
465 // Record that a symbol is forced to be local by a version script.
468 Symbol_table::force_local(Symbol
* sym
)
470 if (!sym
->is_defined() && !sym
->is_common())
472 if (sym
->is_forced_local())
474 // We already got this one.
477 sym
->set_is_forced_local();
478 this->forced_locals_
.push_back(sym
);
481 // Add one symbol from OBJECT to the symbol table. NAME is symbol
482 // name and VERSION is the version; both are canonicalized. DEF is
483 // whether this is the default version.
485 // If DEF is true, then this is the definition of a default version of
486 // a symbol. That means that any lookup of NAME/NULL and any lookup
487 // of NAME/VERSION should always return the same symbol. This is
488 // obvious for references, but in particular we want to do this for
489 // definitions: overriding NAME/NULL should also override
490 // NAME/VERSION. If we don't do that, it would be very hard to
491 // override functions in a shared library which uses versioning.
493 // We implement this by simply making both entries in the hash table
494 // point to the same Symbol structure. That is easy enough if this is
495 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
496 // that we have seen both already, in which case they will both have
497 // independent entries in the symbol table. We can't simply change
498 // the symbol table entry, because we have pointers to the entries
499 // attached to the object files. So we mark the entry attached to the
500 // object file as a forwarder, and record it in the forwarders_ map.
501 // Note that entries in the hash table will never be marked as
504 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
505 // symbol exactly as it existed in the input file. SYM is usually
506 // that as well, but can be modified, for instance if we determine
507 // it's in a to-be-discarded section.
509 template<int size
, bool big_endian
>
511 Symbol_table::add_from_object(Object
* object
,
513 Stringpool::Key name_key
,
515 Stringpool::Key version_key
,
517 const elfcpp::Sym
<size
, big_endian
>& sym
,
518 const elfcpp::Sym
<size
, big_endian
>& orig_sym
)
520 Symbol
* const snull
= NULL
;
521 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
522 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
525 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
526 std::make_pair(this->table_
.end(), false);
529 const Stringpool::Key vnull_key
= 0;
530 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
535 // ins.first: an iterator, which is a pointer to a pair.
536 // ins.first->first: the key (a pair of name and version).
537 // ins.first->second: the value (Symbol*).
538 // ins.second: true if new entry was inserted, false if not.
540 Sized_symbol
<size
>* ret
;
545 // We already have an entry for NAME/VERSION.
546 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
547 gold_assert(ret
!= NULL
);
549 was_undefined
= ret
->is_undefined();
550 was_common
= ret
->is_common();
552 this->resolve(ret
, sym
, orig_sym
, object
, version
);
558 // This is the first time we have seen NAME/NULL. Make
559 // NAME/NULL point to NAME/VERSION.
560 insdef
.first
->second
= ret
;
562 else if (insdef
.first
->second
!= ret
563 && insdef
.first
->second
->is_undefined())
565 // This is the unfortunate case where we already have
566 // entries for both NAME/VERSION and NAME/NULL. Note
567 // that we don't want to combine them if the existing
568 // symbol is going to override the new one. FIXME: We
569 // currently just test is_undefined, but this may not do
570 // the right thing if the existing symbol is from a
571 // shared library and the new one is from a regular
574 const Sized_symbol
<size
>* sym2
;
575 sym2
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
576 Symbol_table::resolve
<size
, big_endian
>(ret
, sym2
, version
);
577 this->make_forwarder(insdef
.first
->second
, ret
);
578 insdef
.first
->second
= ret
;
584 // This is the first time we have seen NAME/VERSION.
585 gold_assert(ins
.first
->second
== NULL
);
587 was_undefined
= false;
590 if (def
&& !insdef
.second
)
592 // We already have an entry for NAME/NULL. If we override
593 // it, then change it to NAME/VERSION.
594 ret
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
595 this->resolve(ret
, sym
, orig_sym
, object
, version
);
596 ins
.first
->second
= ret
;
600 Sized_target
<size
, big_endian
>* target
=
601 object
->sized_target
<size
, big_endian
>();
602 if (!target
->has_make_symbol())
603 ret
= new Sized_symbol
<size
>();
606 ret
= target
->make_symbol();
609 // This means that we don't want a symbol table
612 this->table_
.erase(ins
.first
);
615 this->table_
.erase(insdef
.first
);
616 // Inserting insdef invalidated ins.
617 this->table_
.erase(std::make_pair(name_key
,
624 ret
->init(name
, version
, object
, sym
);
626 ins
.first
->second
= ret
;
629 // This is the first time we have seen NAME/NULL. Point
630 // it at the new entry for NAME/VERSION.
631 gold_assert(insdef
.second
);
632 insdef
.first
->second
= ret
;
637 // Record every time we see a new undefined symbol, to speed up
639 if (!was_undefined
&& ret
->is_undefined())
640 ++this->saw_undefined_
;
642 // Keep track of common symbols, to speed up common symbol
644 if (!was_common
&& ret
->is_common())
645 this->commons_
.push_back(ret
);
648 ret
->set_is_default();
652 // Add all the symbols in a relocatable object to the hash table.
654 template<int size
, bool big_endian
>
656 Symbol_table::add_from_relobj(
657 Sized_relobj
<size
, big_endian
>* relobj
,
658 const unsigned char* syms
,
660 const char* sym_names
,
661 size_t sym_name_size
,
662 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
)
664 gold_assert(size
== relobj
->target()->get_size());
665 gold_assert(size
== parameters
->target().get_size());
667 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
669 const bool just_symbols
= relobj
->just_symbols();
671 const unsigned char* p
= syms
;
672 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
674 elfcpp::Sym
<size
, big_endian
> sym(p
);
675 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
677 unsigned int st_name
= psym
->get_st_name();
678 if (st_name
>= sym_name_size
)
680 relobj
->error(_("bad global symbol name offset %u at %zu"),
685 const char* name
= sym_names
+ st_name
;
687 // A symbol defined in a section which we are not including must
688 // be treated as an undefined symbol.
689 unsigned char symbuf
[sym_size
];
690 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
691 unsigned int st_shndx
= psym
->get_st_shndx();
692 if (st_shndx
!= elfcpp::SHN_UNDEF
693 && st_shndx
< elfcpp::SHN_LORESERVE
694 && !relobj
->is_section_included(st_shndx
))
696 memcpy(symbuf
, p
, sym_size
);
697 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
698 sw
.put_st_shndx(elfcpp::SHN_UNDEF
);
702 // In an object file, an '@' in the name separates the symbol
703 // name from the version name. If there are two '@' characters,
704 // this is the default version.
705 const char* ver
= strchr(name
, '@');
707 // DEF: is the version default? LOCAL: is the symbol forced local?
713 // The symbol name is of the form foo@VERSION or foo@@VERSION
714 namelen
= ver
- name
;
722 // We don't want to assign a version to an undefined symbol,
723 // even if it is listed in the version script. FIXME: What
724 // about a common symbol?
725 else if (!version_script_
.empty()
726 && psym
->get_st_shndx() != elfcpp::SHN_UNDEF
)
728 // The symbol name did not have a version, but
729 // the version script may assign a version anyway.
730 namelen
= strlen(name
);
732 // Check the global: entries from the version script.
733 const std::string
& version
=
734 version_script_
.get_symbol_version(name
);
735 if (!version
.empty())
736 ver
= version
.c_str();
737 // Check the local: entries from the version script
738 if (version_script_
.symbol_is_local(name
))
745 memcpy(symbuf
, p
, sym_size
);
746 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
747 sw
.put_st_shndx(elfcpp::SHN_ABS
);
748 if (st_shndx
!= elfcpp::SHN_UNDEF
749 && st_shndx
< elfcpp::SHN_LORESERVE
)
751 // Symbol values in object files are section relative.
752 // This is normally what we want, but since here we are
753 // converting the symbol to absolute we need to add the
754 // section address. The section address in an object
755 // file is normally zero, but people can use a linker
756 // script to change it.
757 sw
.put_st_value(sym2
.get_st_value()
758 + relobj
->section_address(st_shndx
));
763 Sized_symbol
<size
>* res
;
766 Stringpool::Key name_key
;
767 name
= this->namepool_
.add(name
, true, &name_key
);
768 res
= this->add_from_object(relobj
, name
, name_key
, NULL
, 0,
771 this->force_local(res
);
775 Stringpool::Key name_key
;
776 name
= this->namepool_
.add_with_length(name
, namelen
, true,
778 Stringpool::Key ver_key
;
779 ver
= this->namepool_
.add(ver
, true, &ver_key
);
781 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
785 (*sympointers
)[i
] = res
;
789 // Add all the symbols in a dynamic object to the hash table.
791 template<int size
, bool big_endian
>
793 Symbol_table::add_from_dynobj(
794 Sized_dynobj
<size
, big_endian
>* dynobj
,
795 const unsigned char* syms
,
797 const char* sym_names
,
798 size_t sym_name_size
,
799 const unsigned char* versym
,
801 const std::vector
<const char*>* version_map
)
803 gold_assert(size
== dynobj
->target()->get_size());
804 gold_assert(size
== parameters
->target().get_size());
806 if (dynobj
->just_symbols())
808 gold_error(_("--just-symbols does not make sense with a shared object"));
812 if (versym
!= NULL
&& versym_size
/ 2 < count
)
814 dynobj
->error(_("too few symbol versions"));
818 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
820 // We keep a list of all STT_OBJECT symbols, so that we can resolve
821 // weak aliases. This is necessary because if the dynamic object
822 // provides the same variable under two names, one of which is a
823 // weak definition, and the regular object refers to the weak
824 // definition, we have to put both the weak definition and the
825 // strong definition into the dynamic symbol table. Given a weak
826 // definition, the only way that we can find the corresponding
827 // strong definition, if any, is to search the symbol table.
828 std::vector
<Sized_symbol
<size
>*> object_symbols
;
830 const unsigned char* p
= syms
;
831 const unsigned char* vs
= versym
;
832 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
834 elfcpp::Sym
<size
, big_endian
> sym(p
);
836 // Ignore symbols with local binding or that have
837 // internal or hidden visibility.
838 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
839 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
840 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
843 unsigned int st_name
= sym
.get_st_name();
844 if (st_name
>= sym_name_size
)
846 dynobj
->error(_("bad symbol name offset %u at %zu"),
851 const char* name
= sym_names
+ st_name
;
853 Sized_symbol
<size
>* res
;
857 Stringpool::Key name_key
;
858 name
= this->namepool_
.add(name
, true, &name_key
);
859 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
864 // Read the version information.
866 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
868 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
869 v
&= elfcpp::VERSYM_VERSION
;
871 // The Sun documentation says that V can be VER_NDX_LOCAL,
872 // or VER_NDX_GLOBAL, or a version index. The meaning of
873 // VER_NDX_LOCAL is defined as "Symbol has local scope."
874 // The old GNU linker will happily generate VER_NDX_LOCAL
875 // for an undefined symbol. I don't know what the Sun
876 // linker will generate.
878 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
879 && sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
881 // This symbol should not be visible outside the object.
885 // At this point we are definitely going to add this symbol.
886 Stringpool::Key name_key
;
887 name
= this->namepool_
.add(name
, true, &name_key
);
889 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
890 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
892 // This symbol does not have a version.
893 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
898 if (v
>= version_map
->size())
900 dynobj
->error(_("versym for symbol %zu out of range: %u"),
905 const char* version
= (*version_map
)[v
];
908 dynobj
->error(_("versym for symbol %zu has no name: %u"),
913 Stringpool::Key version_key
;
914 version
= this->namepool_
.add(version
, true, &version_key
);
916 // If this is an absolute symbol, and the version name
917 // and symbol name are the same, then this is the
918 // version definition symbol. These symbols exist to
919 // support using -u to pull in particular versions. We
920 // do not want to record a version for them.
921 if (sym
.get_st_shndx() == elfcpp::SHN_ABS
922 && name_key
== version_key
)
923 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
927 const bool def
= (!hidden
928 && (sym
.get_st_shndx()
929 != elfcpp::SHN_UNDEF
));
930 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
931 version_key
, def
, sym
, sym
);
936 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
937 && sym
.get_st_type() == elfcpp::STT_OBJECT
)
938 object_symbols
.push_back(res
);
941 this->record_weak_aliases(&object_symbols
);
944 // This is used to sort weak aliases. We sort them first by section
945 // index, then by offset, then by weak ahead of strong.
948 class Weak_alias_sorter
951 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
956 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
957 const Sized_symbol
<size
>* s2
) const
959 if (s1
->shndx() != s2
->shndx())
960 return s1
->shndx() < s2
->shndx();
961 if (s1
->value() != s2
->value())
962 return s1
->value() < s2
->value();
963 if (s1
->binding() != s2
->binding())
965 if (s1
->binding() == elfcpp::STB_WEAK
)
967 if (s2
->binding() == elfcpp::STB_WEAK
)
970 return std::string(s1
->name()) < std::string(s2
->name());
973 // SYMBOLS is a list of object symbols from a dynamic object. Look
974 // for any weak aliases, and record them so that if we add the weak
975 // alias to the dynamic symbol table, we also add the corresponding
980 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
982 // Sort the vector by section index, then by offset, then by weak
984 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
986 // Walk through the vector. For each weak definition, record
988 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
993 if ((*p
)->binding() != elfcpp::STB_WEAK
)
996 // Build a circular list of weak aliases. Each symbol points to
997 // the next one in the circular list.
999 Sized_symbol
<size
>* from_sym
= *p
;
1000 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
1001 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
1003 if ((*q
)->shndx() != from_sym
->shndx()
1004 || (*q
)->value() != from_sym
->value())
1007 this->weak_aliases_
[from_sym
] = *q
;
1008 from_sym
->set_has_alias();
1014 this->weak_aliases_
[from_sym
] = *p
;
1015 from_sym
->set_has_alias();
1022 // Create and return a specially defined symbol. If ONLY_IF_REF is
1023 // true, then only create the symbol if there is a reference to it.
1024 // If this does not return NULL, it sets *POLDSYM to the existing
1025 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1027 template<int size
, bool big_endian
>
1029 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1031 Sized_symbol
<size
>** poldsym
)
1034 Sized_symbol
<size
>* sym
;
1035 bool add_to_table
= false;
1036 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1038 // If the caller didn't give us a version, see if we get one from
1039 // the version script.
1040 if (*pversion
== NULL
)
1042 const std::string
& v(this->version_script_
.get_symbol_version(*pname
));
1044 *pversion
= v
.c_str();
1049 oldsym
= this->lookup(*pname
, *pversion
);
1050 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1053 *pname
= oldsym
->name();
1054 *pversion
= oldsym
->version();
1058 // Canonicalize NAME and VERSION.
1059 Stringpool::Key name_key
;
1060 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1062 Stringpool::Key version_key
= 0;
1063 if (*pversion
!= NULL
)
1064 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1066 Symbol
* const snull
= NULL
;
1067 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1068 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1074 // We already have a symbol table entry for NAME/VERSION.
1075 oldsym
= ins
.first
->second
;
1076 gold_assert(oldsym
!= NULL
);
1080 // We haven't seen this symbol before.
1081 gold_assert(ins
.first
->second
== NULL
);
1082 add_to_table
= true;
1083 add_loc
= ins
.first
;
1088 const Target
& target
= parameters
->target();
1089 if (!target
.has_make_symbol())
1090 sym
= new Sized_symbol
<size
>();
1093 gold_assert(target
.get_size() == size
);
1094 gold_assert(target
.is_big_endian() ? big_endian
: !big_endian
);
1095 typedef Sized_target
<size
, big_endian
> My_target
;
1096 const My_target
* sized_target
=
1097 static_cast<const My_target
*>(&target
);
1098 sym
= sized_target
->make_symbol();
1104 add_loc
->second
= sym
;
1106 gold_assert(oldsym
!= NULL
);
1108 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1113 // Define a symbol based on an Output_data.
1116 Symbol_table::define_in_output_data(const char* name
,
1117 const char* version
,
1122 elfcpp::STB binding
,
1123 elfcpp::STV visibility
,
1124 unsigned char nonvis
,
1125 bool offset_is_from_end
,
1128 if (parameters
->target().get_size() == 32)
1130 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1131 return this->do_define_in_output_data
<32>(name
, version
, od
,
1132 value
, symsize
, type
, binding
,
1140 else if (parameters
->target().get_size() == 64)
1142 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1143 return this->do_define_in_output_data
<64>(name
, version
, od
,
1144 value
, symsize
, type
, binding
,
1156 // Define a symbol in an Output_data, sized version.
1160 Symbol_table::do_define_in_output_data(
1162 const char* version
,
1164 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1165 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1167 elfcpp::STB binding
,
1168 elfcpp::STV visibility
,
1169 unsigned char nonvis
,
1170 bool offset_is_from_end
,
1173 Sized_symbol
<size
>* sym
;
1174 Sized_symbol
<size
>* oldsym
;
1176 if (parameters
->target().is_big_endian())
1178 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1179 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1180 only_if_ref
, &oldsym
);
1187 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1188 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1189 only_if_ref
, &oldsym
);
1198 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1199 sym
->init(name
, od
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1200 offset_is_from_end
);
1204 if (binding
== elfcpp::STB_LOCAL
1205 || this->version_script_
.symbol_is_local(name
))
1206 this->force_local(sym
);
1210 if (Symbol_table::should_override_with_special(oldsym
))
1211 this->override_with_special(oldsym
, sym
);
1216 // Define a symbol based on an Output_segment.
1219 Symbol_table::define_in_output_segment(const char* name
,
1220 const char* version
, Output_segment
* os
,
1224 elfcpp::STB binding
,
1225 elfcpp::STV visibility
,
1226 unsigned char nonvis
,
1227 Symbol::Segment_offset_base offset_base
,
1230 if (parameters
->target().get_size() == 32)
1232 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1233 return this->do_define_in_output_segment
<32>(name
, version
, os
,
1234 value
, symsize
, type
,
1235 binding
, visibility
, nonvis
,
1236 offset_base
, only_if_ref
);
1241 else if (parameters
->target().get_size() == 64)
1243 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1244 return this->do_define_in_output_segment
<64>(name
, version
, os
,
1245 value
, symsize
, type
,
1246 binding
, visibility
, nonvis
,
1247 offset_base
, only_if_ref
);
1256 // Define a symbol in an Output_segment, sized version.
1260 Symbol_table::do_define_in_output_segment(
1262 const char* version
,
1264 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1265 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1267 elfcpp::STB binding
,
1268 elfcpp::STV visibility
,
1269 unsigned char nonvis
,
1270 Symbol::Segment_offset_base offset_base
,
1273 Sized_symbol
<size
>* sym
;
1274 Sized_symbol
<size
>* oldsym
;
1276 if (parameters
->target().is_big_endian())
1278 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1279 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1280 only_if_ref
, &oldsym
);
1287 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1288 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1289 only_if_ref
, &oldsym
);
1298 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1299 sym
->init(name
, os
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1304 if (binding
== elfcpp::STB_LOCAL
1305 || this->version_script_
.symbol_is_local(name
))
1306 this->force_local(sym
);
1310 if (Symbol_table::should_override_with_special(oldsym
))
1311 this->override_with_special(oldsym
, sym
);
1316 // Define a special symbol with a constant value. It is a multiple
1317 // definition error if this symbol is already defined.
1320 Symbol_table::define_as_constant(const char* name
,
1321 const char* version
,
1325 elfcpp::STB binding
,
1326 elfcpp::STV visibility
,
1327 unsigned char nonvis
,
1329 bool force_override
)
1331 if (parameters
->target().get_size() == 32)
1333 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1334 return this->do_define_as_constant
<32>(name
, version
, value
,
1335 symsize
, type
, binding
,
1336 visibility
, nonvis
, only_if_ref
,
1342 else if (parameters
->target().get_size() == 64)
1344 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1345 return this->do_define_as_constant
<64>(name
, version
, value
,
1346 symsize
, type
, binding
,
1347 visibility
, nonvis
, only_if_ref
,
1357 // Define a symbol as a constant, sized version.
1361 Symbol_table::do_define_as_constant(
1363 const char* version
,
1364 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1365 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1367 elfcpp::STB binding
,
1368 elfcpp::STV visibility
,
1369 unsigned char nonvis
,
1371 bool force_override
)
1373 Sized_symbol
<size
>* sym
;
1374 Sized_symbol
<size
>* oldsym
;
1376 if (parameters
->target().is_big_endian())
1378 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1379 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1380 only_if_ref
, &oldsym
);
1387 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1388 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1389 only_if_ref
, &oldsym
);
1398 gold_assert(version
== NULL
|| version
== name
|| oldsym
!= NULL
);
1399 sym
->init(name
, value
, symsize
, type
, binding
, visibility
, nonvis
);
1403 if (binding
== elfcpp::STB_LOCAL
1404 || this->version_script_
.symbol_is_local(name
))
1405 this->force_local(sym
);
1409 if (force_override
|| Symbol_table::should_override_with_special(oldsym
))
1410 this->override_with_special(oldsym
, sym
);
1415 // Define a set of symbols in output sections.
1418 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1419 const Define_symbol_in_section
* p
,
1422 for (int i
= 0; i
< count
; ++i
, ++p
)
1424 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1426 this->define_in_output_data(p
->name
, NULL
, os
, p
->value
,
1427 p
->size
, p
->type
, p
->binding
,
1428 p
->visibility
, p
->nonvis
,
1429 p
->offset_is_from_end
,
1430 only_if_ref
|| p
->only_if_ref
);
1432 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1433 p
->binding
, p
->visibility
, p
->nonvis
,
1434 only_if_ref
|| p
->only_if_ref
,
1439 // Define a set of symbols in output segments.
1442 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1443 const Define_symbol_in_segment
* p
,
1446 for (int i
= 0; i
< count
; ++i
, ++p
)
1448 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1449 p
->segment_flags_set
,
1450 p
->segment_flags_clear
);
1452 this->define_in_output_segment(p
->name
, NULL
, os
, p
->value
,
1453 p
->size
, p
->type
, p
->binding
,
1454 p
->visibility
, p
->nonvis
,
1456 only_if_ref
|| p
->only_if_ref
);
1458 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1459 p
->binding
, p
->visibility
, p
->nonvis
,
1460 only_if_ref
|| p
->only_if_ref
,
1465 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1466 // symbol should be defined--typically a .dyn.bss section. VALUE is
1467 // the offset within POSD.
1471 Symbol_table::define_with_copy_reloc(
1472 Sized_symbol
<size
>* csym
,
1474 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1476 gold_assert(csym
->is_from_dynobj());
1477 gold_assert(!csym
->is_copied_from_dynobj());
1478 Object
* object
= csym
->object();
1479 gold_assert(object
->is_dynamic());
1480 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1482 // Our copied variable has to override any variable in a shared
1484 elfcpp::STB binding
= csym
->binding();
1485 if (binding
== elfcpp::STB_WEAK
)
1486 binding
= elfcpp::STB_GLOBAL
;
1488 this->define_in_output_data(csym
->name(), csym
->version(),
1489 posd
, value
, csym
->symsize(),
1490 csym
->type(), binding
,
1491 csym
->visibility(), csym
->nonvis(),
1494 csym
->set_is_copied_from_dynobj();
1495 csym
->set_needs_dynsym_entry();
1497 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1499 // We have now defined all aliases, but we have not entered them all
1500 // in the copied_symbol_dynobjs_ map.
1501 if (csym
->has_alias())
1506 sym
= this->weak_aliases_
[sym
];
1509 gold_assert(sym
->output_data() == posd
);
1511 sym
->set_is_copied_from_dynobj();
1512 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1517 // SYM is defined using a COPY reloc. Return the dynamic object where
1518 // the original definition was found.
1521 Symbol_table::get_copy_source(const Symbol
* sym
) const
1523 gold_assert(sym
->is_copied_from_dynobj());
1524 Copied_symbol_dynobjs::const_iterator p
=
1525 this->copied_symbol_dynobjs_
.find(sym
);
1526 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1530 // Set the dynamic symbol indexes. INDEX is the index of the first
1531 // global dynamic symbol. Pointers to the symbols are stored into the
1532 // vector SYMS. The names are added to DYNPOOL. This returns an
1533 // updated dynamic symbol index.
1536 Symbol_table::set_dynsym_indexes(unsigned int index
,
1537 std::vector
<Symbol
*>* syms
,
1538 Stringpool
* dynpool
,
1541 for (Symbol_table_type::iterator p
= this->table_
.begin();
1542 p
!= this->table_
.end();
1545 Symbol
* sym
= p
->second
;
1547 // Note that SYM may already have a dynamic symbol index, since
1548 // some symbols appear more than once in the symbol table, with
1549 // and without a version.
1551 if (!sym
->should_add_dynsym_entry())
1552 sym
->set_dynsym_index(-1U);
1553 else if (!sym
->has_dynsym_index())
1555 sym
->set_dynsym_index(index
);
1557 syms
->push_back(sym
);
1558 dynpool
->add(sym
->name(), false, NULL
);
1560 // Record any version information.
1561 if (sym
->version() != NULL
)
1562 versions
->record_version(this, dynpool
, sym
);
1566 // Finish up the versions. In some cases this may add new dynamic
1568 index
= versions
->finalize(this, index
, syms
);
1573 // Set the final values for all the symbols. The index of the first
1574 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1575 // file offset OFF. Add their names to POOL. Return the new file
1576 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1579 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
1580 size_t dyncount
, Stringpool
* pool
,
1581 unsigned int *plocal_symcount
)
1585 gold_assert(*plocal_symcount
!= 0);
1586 this->first_global_index_
= *plocal_symcount
;
1588 this->dynamic_offset_
= dynoff
;
1589 this->first_dynamic_global_index_
= dyn_global_index
;
1590 this->dynamic_count_
= dyncount
;
1592 if (parameters
->target().get_size() == 32)
1594 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1595 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
1600 else if (parameters
->target().get_size() == 64)
1602 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1603 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
1611 // Now that we have the final symbol table, we can reliably note
1612 // which symbols should get warnings.
1613 this->warnings_
.note_warnings(this);
1618 // SYM is going into the symbol table at *PINDEX. Add the name to
1619 // POOL, update *PINDEX and *POFF.
1623 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
1624 unsigned int* pindex
, off_t
* poff
)
1626 sym
->set_symtab_index(*pindex
);
1627 pool
->add(sym
->name(), false, NULL
);
1629 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
1632 // Set the final value for all the symbols. This is called after
1633 // Layout::finalize, so all the output sections have their final
1638 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
1639 unsigned int* plocal_symcount
)
1641 off
= align_address(off
, size
>> 3);
1642 this->offset_
= off
;
1644 unsigned int index
= *plocal_symcount
;
1645 const unsigned int orig_index
= index
;
1647 // First do all the symbols which have been forced to be local, as
1648 // they must appear before all global symbols.
1649 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
1650 p
!= this->forced_locals_
.end();
1654 gold_assert(sym
->is_forced_local());
1655 if (this->sized_finalize_symbol
<size
>(sym
))
1657 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1662 // Now do all the remaining symbols.
1663 for (Symbol_table_type::iterator p
= this->table_
.begin();
1664 p
!= this->table_
.end();
1667 Symbol
* sym
= p
->second
;
1668 if (this->sized_finalize_symbol
<size
>(sym
))
1669 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1672 this->output_count_
= index
- orig_index
;
1677 // Finalize the symbol SYM. This returns true if the symbol should be
1678 // added to the symbol table, false otherwise.
1682 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
1684 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
1686 // The default version of a symbol may appear twice in the symbol
1687 // table. We only need to finalize it once.
1688 if (sym
->has_symtab_index())
1693 gold_assert(!sym
->has_symtab_index());
1694 sym
->set_symtab_index(-1U);
1695 gold_assert(sym
->dynsym_index() == -1U);
1699 typename Sized_symbol
<size
>::Value_type value
;
1701 switch (sym
->source())
1703 case Symbol::FROM_OBJECT
:
1705 unsigned int shndx
= sym
->shndx();
1707 // FIXME: We need some target specific support here.
1708 if (shndx
>= elfcpp::SHN_LORESERVE
1709 && shndx
!= elfcpp::SHN_ABS
1710 && shndx
!= elfcpp::SHN_COMMON
)
1712 gold_error(_("%s: unsupported symbol section 0x%x"),
1713 sym
->demangled_name().c_str(), shndx
);
1714 shndx
= elfcpp::SHN_UNDEF
;
1717 Object
* symobj
= sym
->object();
1718 if (symobj
->is_dynamic())
1721 shndx
= elfcpp::SHN_UNDEF
;
1723 else if (shndx
== elfcpp::SHN_UNDEF
)
1725 else if (shndx
== elfcpp::SHN_ABS
|| shndx
== elfcpp::SHN_COMMON
)
1726 value
= sym
->value();
1729 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1730 section_offset_type secoff
;
1731 Output_section
* os
= relobj
->output_section(shndx
, &secoff
);
1735 sym
->set_symtab_index(-1U);
1736 gold_assert(sym
->dynsym_index() == -1U);
1740 if (sym
->type() == elfcpp::STT_TLS
)
1741 value
= sym
->value() + os
->tls_offset() + secoff
;
1743 value
= sym
->value() + os
->address() + secoff
;
1748 case Symbol::IN_OUTPUT_DATA
:
1750 Output_data
* od
= sym
->output_data();
1751 value
= sym
->value() + od
->address();
1752 if (sym
->offset_is_from_end())
1753 value
+= od
->data_size();
1757 case Symbol::IN_OUTPUT_SEGMENT
:
1759 Output_segment
* os
= sym
->output_segment();
1760 value
= sym
->value() + os
->vaddr();
1761 switch (sym
->offset_base())
1763 case Symbol::SEGMENT_START
:
1765 case Symbol::SEGMENT_END
:
1766 value
+= os
->memsz();
1768 case Symbol::SEGMENT_BSS
:
1769 value
+= os
->filesz();
1777 case Symbol::CONSTANT
:
1778 value
= sym
->value();
1785 sym
->set_value(value
);
1787 if (parameters
->options().strip_all())
1789 sym
->set_symtab_index(-1U);
1796 // Write out the global symbols.
1799 Symbol_table::write_globals(const Input_objects
* input_objects
,
1800 const Stringpool
* sympool
,
1801 const Stringpool
* dynpool
, Output_file
* of
) const
1803 switch (parameters
->size_and_endianness())
1805 #ifdef HAVE_TARGET_32_LITTLE
1806 case Parameters::TARGET_32_LITTLE
:
1807 this->sized_write_globals
<32, false>(input_objects
, sympool
,
1811 #ifdef HAVE_TARGET_32_BIG
1812 case Parameters::TARGET_32_BIG
:
1813 this->sized_write_globals
<32, true>(input_objects
, sympool
,
1817 #ifdef HAVE_TARGET_64_LITTLE
1818 case Parameters::TARGET_64_LITTLE
:
1819 this->sized_write_globals
<64, false>(input_objects
, sympool
,
1823 #ifdef HAVE_TARGET_64_BIG
1824 case Parameters::TARGET_64_BIG
:
1825 this->sized_write_globals
<64, true>(input_objects
, sympool
,
1834 // Write out the global symbols.
1836 template<int size
, bool big_endian
>
1838 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
1839 const Stringpool
* sympool
,
1840 const Stringpool
* dynpool
,
1841 Output_file
* of
) const
1843 const Target
& target
= parameters
->target();
1845 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1847 const unsigned int output_count
= this->output_count_
;
1848 const section_size_type oview_size
= output_count
* sym_size
;
1849 const unsigned int first_global_index
= this->first_global_index_
;
1850 unsigned char* psyms
;
1851 if (this->offset_
== 0 || output_count
== 0)
1854 psyms
= of
->get_output_view(this->offset_
, oview_size
);
1856 const unsigned int dynamic_count
= this->dynamic_count_
;
1857 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
1858 const unsigned int first_dynamic_global_index
=
1859 this->first_dynamic_global_index_
;
1860 unsigned char* dynamic_view
;
1861 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
1862 dynamic_view
= NULL
;
1864 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
1866 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1867 p
!= this->table_
.end();
1870 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1872 // Possibly warn about unresolved symbols in shared libraries.
1873 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
1875 unsigned int sym_index
= sym
->symtab_index();
1876 unsigned int dynsym_index
;
1877 if (dynamic_view
== NULL
)
1880 dynsym_index
= sym
->dynsym_index();
1882 if (sym_index
== -1U && dynsym_index
== -1U)
1884 // This symbol is not included in the output file.
1889 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
1890 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
1891 switch (sym
->source())
1893 case Symbol::FROM_OBJECT
:
1895 unsigned int in_shndx
= sym
->shndx();
1897 // FIXME: We need some target specific support here.
1898 if (in_shndx
>= elfcpp::SHN_LORESERVE
1899 && in_shndx
!= elfcpp::SHN_ABS
1900 && in_shndx
!= elfcpp::SHN_COMMON
)
1902 gold_error(_("%s: unsupported symbol section 0x%x"),
1903 sym
->demangled_name().c_str(), in_shndx
);
1908 Object
* symobj
= sym
->object();
1909 if (symobj
->is_dynamic())
1911 if (sym
->needs_dynsym_value())
1912 dynsym_value
= target
.dynsym_value(sym
);
1913 shndx
= elfcpp::SHN_UNDEF
;
1915 else if (in_shndx
== elfcpp::SHN_UNDEF
1916 || in_shndx
== elfcpp::SHN_ABS
1917 || in_shndx
== elfcpp::SHN_COMMON
)
1921 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1922 section_offset_type secoff
;
1923 Output_section
* os
= relobj
->output_section(in_shndx
,
1925 gold_assert(os
!= NULL
);
1926 shndx
= os
->out_shndx();
1928 // In object files symbol values are section
1930 if (parameters
->options().relocatable())
1931 sym_value
-= os
->address();
1937 case Symbol::IN_OUTPUT_DATA
:
1938 shndx
= sym
->output_data()->out_shndx();
1941 case Symbol::IN_OUTPUT_SEGMENT
:
1942 shndx
= elfcpp::SHN_ABS
;
1945 case Symbol::CONSTANT
:
1946 shndx
= elfcpp::SHN_ABS
;
1953 if (sym_index
!= -1U)
1955 sym_index
-= first_global_index
;
1956 gold_assert(sym_index
< output_count
);
1957 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
1958 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
1962 if (dynsym_index
!= -1U)
1964 dynsym_index
-= first_dynamic_global_index
;
1965 gold_assert(dynsym_index
< dynamic_count
);
1966 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
1967 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
1972 of
->write_output_view(this->offset_
, oview_size
, psyms
);
1973 if (dynamic_view
!= NULL
)
1974 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
1977 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1978 // strtab holding the name.
1980 template<int size
, bool big_endian
>
1982 Symbol_table::sized_write_symbol(
1983 Sized_symbol
<size
>* sym
,
1984 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1986 const Stringpool
* pool
,
1987 unsigned char* p
) const
1989 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
1990 osym
.put_st_name(pool
->get_offset(sym
->name()));
1991 osym
.put_st_value(value
);
1992 osym
.put_st_size(sym
->symsize());
1993 // A version script may have overridden the default binding.
1994 if (sym
->is_forced_local())
1995 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, sym
->type()));
1997 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
1998 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
1999 osym
.put_st_shndx(shndx
);
2002 // Check for unresolved symbols in shared libraries. This is
2003 // controlled by the --allow-shlib-undefined option.
2005 // We only warn about libraries for which we have seen all the
2006 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2007 // which were not seen in this link. If we didn't see a DT_NEEDED
2008 // entry, we aren't going to be able to reliably report whether the
2009 // symbol is undefined.
2011 // We also don't warn about libraries found in the system library
2012 // directory (the directory were we find libc.so); we assume that
2013 // those libraries are OK. This heuristic avoids problems in
2014 // GNU/Linux, in which -ldl can have undefined references satisfied by
2018 Symbol_table::warn_about_undefined_dynobj_symbol(
2019 const Input_objects
* input_objects
,
2022 if (sym
->source() == Symbol::FROM_OBJECT
2023 && sym
->object()->is_dynamic()
2024 && sym
->shndx() == elfcpp::SHN_UNDEF
2025 && sym
->binding() != elfcpp::STB_WEAK
2026 && !parameters
->options().allow_shlib_undefined()
2027 && !parameters
->target().is_defined_by_abi(sym
)
2028 && !input_objects
->found_in_system_library_directory(sym
->object()))
2030 // A very ugly cast.
2031 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
2032 if (!dynobj
->has_unknown_needed_entries())
2033 gold_error(_("%s: undefined reference to '%s'"),
2034 sym
->object()->name().c_str(),
2035 sym
->demangled_name().c_str());
2039 // Write out a section symbol. Return the update offset.
2042 Symbol_table::write_section_symbol(const Output_section
*os
,
2046 switch (parameters
->size_and_endianness())
2048 #ifdef HAVE_TARGET_32_LITTLE
2049 case Parameters::TARGET_32_LITTLE
:
2050 this->sized_write_section_symbol
<32, false>(os
, of
, offset
);
2053 #ifdef HAVE_TARGET_32_BIG
2054 case Parameters::TARGET_32_BIG
:
2055 this->sized_write_section_symbol
<32, true>(os
, of
, offset
);
2058 #ifdef HAVE_TARGET_64_LITTLE
2059 case Parameters::TARGET_64_LITTLE
:
2060 this->sized_write_section_symbol
<64, false>(os
, of
, offset
);
2063 #ifdef HAVE_TARGET_64_BIG
2064 case Parameters::TARGET_64_BIG
:
2065 this->sized_write_section_symbol
<64, true>(os
, of
, offset
);
2073 // Write out a section symbol, specialized for size and endianness.
2075 template<int size
, bool big_endian
>
2077 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
2081 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2083 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
2085 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
2086 osym
.put_st_name(0);
2087 osym
.put_st_value(os
->address());
2088 osym
.put_st_size(0);
2089 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
2090 elfcpp::STT_SECTION
));
2091 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
2092 osym
.put_st_shndx(os
->out_shndx());
2094 of
->write_output_view(offset
, sym_size
, pov
);
2097 // Print statistical information to stderr. This is used for --stats.
2100 Symbol_table::print_stats() const
2102 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2103 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2104 program_name
, this->table_
.size(), this->table_
.bucket_count());
2106 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
2107 program_name
, this->table_
.size());
2109 this->namepool_
.print_stats("symbol table stringpool");
2112 // We check for ODR violations by looking for symbols with the same
2113 // name for which the debugging information reports that they were
2114 // defined in different source locations. When comparing the source
2115 // location, we consider instances with the same base filename and
2116 // line number to be the same. This is because different object
2117 // files/shared libraries can include the same header file using
2118 // different paths, and we don't want to report an ODR violation in
2121 // This struct is used to compare line information, as returned by
2122 // Dwarf_line_info::one_addr2line. It implements a < comparison
2123 // operator used with std::set.
2125 struct Odr_violation_compare
2128 operator()(const std::string
& s1
, const std::string
& s2
) const
2130 std::string::size_type pos1
= s1
.rfind('/');
2131 std::string::size_type pos2
= s2
.rfind('/');
2132 if (pos1
== std::string::npos
2133 || pos2
== std::string::npos
)
2135 return s1
.compare(pos1
, std::string::npos
,
2136 s2
, pos2
, std::string::npos
) < 0;
2140 // Check candidate_odr_violations_ to find symbols with the same name
2141 // but apparently different definitions (different source-file/line-no).
2144 Symbol_table::detect_odr_violations(const Task
* task
,
2145 const char* output_file_name
) const
2147 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
2148 it
!= candidate_odr_violations_
.end();
2151 const char* symbol_name
= it
->first
;
2152 // We use a sorted set so the output is deterministic.
2153 std::set
<std::string
, Odr_violation_compare
> line_nums
;
2155 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
2156 locs
= it
->second
.begin();
2157 locs
!= it
->second
.end();
2160 // We need to lock the object in order to read it. This
2161 // means that we have to run in a singleton Task. If we
2162 // want to run this in a general Task for better
2163 // performance, we will need one Task for object, plus
2164 // appropriate locking to ensure that we don't conflict with
2165 // other uses of the object.
2166 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2167 std::string lineno
= Dwarf_line_info::one_addr2line(
2168 locs
->object
, locs
->shndx
, locs
->offset
);
2169 if (!lineno
.empty())
2170 line_nums
.insert(lineno
);
2173 if (line_nums
.size() > 1)
2175 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2176 "places (possible ODR violation):"),
2177 output_file_name
, demangle(symbol_name
).c_str());
2178 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2179 it2
!= line_nums
.end();
2181 fprintf(stderr
, " %s\n", it2
->c_str());
2186 // Warnings functions.
2188 // Add a new warning.
2191 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2192 const std::string
& warning
)
2194 name
= symtab
->canonicalize_name(name
);
2195 this->warnings_
[name
].set(obj
, warning
);
2198 // Look through the warnings and mark the symbols for which we should
2199 // warn. This is called during Layout::finalize when we know the
2200 // sources for all the symbols.
2203 Warnings::note_warnings(Symbol_table
* symtab
)
2205 for (Warning_table::iterator p
= this->warnings_
.begin();
2206 p
!= this->warnings_
.end();
2209 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2211 && sym
->source() == Symbol::FROM_OBJECT
2212 && sym
->object() == p
->second
.object
)
2213 sym
->set_has_warning();
2217 // Issue a warning. This is called when we see a relocation against a
2218 // symbol for which has a warning.
2220 template<int size
, bool big_endian
>
2222 Warnings::issue_warning(const Symbol
* sym
,
2223 const Relocate_info
<size
, big_endian
>* relinfo
,
2224 size_t relnum
, off_t reloffset
) const
2226 gold_assert(sym
->has_warning());
2227 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2228 gold_assert(p
!= this->warnings_
.end());
2229 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2230 "%s", p
->second
.text
.c_str());
2233 // Instantiate the templates we need. We could use the configure
2234 // script to restrict this to only the ones needed for implemented
2237 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2240 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2243 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2246 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2249 #ifdef HAVE_TARGET_32_LITTLE
2252 Symbol_table::add_from_relobj
<32, false>(
2253 Sized_relobj
<32, false>* relobj
,
2254 const unsigned char* syms
,
2256 const char* sym_names
,
2257 size_t sym_name_size
,
2258 Sized_relobj
<32, true>::Symbols
* sympointers
);
2261 #ifdef HAVE_TARGET_32_BIG
2264 Symbol_table::add_from_relobj
<32, true>(
2265 Sized_relobj
<32, true>* relobj
,
2266 const unsigned char* syms
,
2268 const char* sym_names
,
2269 size_t sym_name_size
,
2270 Sized_relobj
<32, false>::Symbols
* sympointers
);
2273 #ifdef HAVE_TARGET_64_LITTLE
2276 Symbol_table::add_from_relobj
<64, false>(
2277 Sized_relobj
<64, false>* relobj
,
2278 const unsigned char* syms
,
2280 const char* sym_names
,
2281 size_t sym_name_size
,
2282 Sized_relobj
<64, true>::Symbols
* sympointers
);
2285 #ifdef HAVE_TARGET_64_BIG
2288 Symbol_table::add_from_relobj
<64, true>(
2289 Sized_relobj
<64, true>* relobj
,
2290 const unsigned char* syms
,
2292 const char* sym_names
,
2293 size_t sym_name_size
,
2294 Sized_relobj
<64, false>::Symbols
* sympointers
);
2297 #ifdef HAVE_TARGET_32_LITTLE
2300 Symbol_table::add_from_dynobj
<32, false>(
2301 Sized_dynobj
<32, false>* dynobj
,
2302 const unsigned char* syms
,
2304 const char* sym_names
,
2305 size_t sym_name_size
,
2306 const unsigned char* versym
,
2308 const std::vector
<const char*>* version_map
);
2311 #ifdef HAVE_TARGET_32_BIG
2314 Symbol_table::add_from_dynobj
<32, true>(
2315 Sized_dynobj
<32, true>* dynobj
,
2316 const unsigned char* syms
,
2318 const char* sym_names
,
2319 size_t sym_name_size
,
2320 const unsigned char* versym
,
2322 const std::vector
<const char*>* version_map
);
2325 #ifdef HAVE_TARGET_64_LITTLE
2328 Symbol_table::add_from_dynobj
<64, false>(
2329 Sized_dynobj
<64, false>* dynobj
,
2330 const unsigned char* syms
,
2332 const char* sym_names
,
2333 size_t sym_name_size
,
2334 const unsigned char* versym
,
2336 const std::vector
<const char*>* version_map
);
2339 #ifdef HAVE_TARGET_64_BIG
2342 Symbol_table::add_from_dynobj
<64, true>(
2343 Sized_dynobj
<64, true>* dynobj
,
2344 const unsigned char* syms
,
2346 const char* sym_names
,
2347 size_t sym_name_size
,
2348 const unsigned char* versym
,
2350 const std::vector
<const char*>* version_map
);
2353 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2356 Symbol_table::define_with_copy_reloc
<32>(
2357 Sized_symbol
<32>* sym
,
2359 elfcpp::Elf_types
<32>::Elf_Addr value
);
2362 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2365 Symbol_table::define_with_copy_reloc
<64>(
2366 Sized_symbol
<64>* sym
,
2368 elfcpp::Elf_types
<64>::Elf_Addr value
);
2371 #ifdef HAVE_TARGET_32_LITTLE
2374 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
2375 const Relocate_info
<32, false>* relinfo
,
2376 size_t relnum
, off_t reloffset
) const;
2379 #ifdef HAVE_TARGET_32_BIG
2382 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
2383 const Relocate_info
<32, true>* relinfo
,
2384 size_t relnum
, off_t reloffset
) const;
2387 #ifdef HAVE_TARGET_64_LITTLE
2390 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
2391 const Relocate_info
<64, false>* relinfo
,
2392 size_t relnum
, off_t reloffset
) const;
2395 #ifdef HAVE_TARGET_64_BIG
2398 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
2399 const Relocate_info
<64, true>* relinfo
,
2400 size_t relnum
, off_t reloffset
) const;
2403 } // End namespace gold.