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_(), tls_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 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
482 // is only called for undefined symbols, when at least one --wrap
486 Symbol_table::wrap_symbol(Object
* object
, const char* name
,
487 Stringpool::Key
* name_key
)
489 // For some targets, we need to ignore a specific character when
490 // wrapping, and add it back later.
492 if (name
[0] == object
->target()->wrap_char())
498 if (parameters
->options().is_wrap(name
))
500 // Turn NAME into __wrap_NAME.
507 // This will give us both the old and new name in NAMEPOOL_, but
508 // that is OK. Only the versions we need will wind up in the
509 // real string table in the output file.
510 return this->namepool_
.add(s
.c_str(), true, name_key
);
513 const char* const real_prefix
= "__real_";
514 const size_t real_prefix_length
= strlen(real_prefix
);
515 if (strncmp(name
, real_prefix
, real_prefix_length
) == 0
516 && parameters
->options().is_wrap(name
+ real_prefix_length
))
518 // Turn __real_NAME into NAME.
522 s
+= name
+ real_prefix_length
;
523 return this->namepool_
.add(s
.c_str(), true, name_key
);
529 // Add one symbol from OBJECT to the symbol table. NAME is symbol
530 // name and VERSION is the version; both are canonicalized. DEF is
531 // whether this is the default version.
533 // If DEF is true, then this is the definition of a default version of
534 // a symbol. That means that any lookup of NAME/NULL and any lookup
535 // of NAME/VERSION should always return the same symbol. This is
536 // obvious for references, but in particular we want to do this for
537 // definitions: overriding NAME/NULL should also override
538 // NAME/VERSION. If we don't do that, it would be very hard to
539 // override functions in a shared library which uses versioning.
541 // We implement this by simply making both entries in the hash table
542 // point to the same Symbol structure. That is easy enough if this is
543 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
544 // that we have seen both already, in which case they will both have
545 // independent entries in the symbol table. We can't simply change
546 // the symbol table entry, because we have pointers to the entries
547 // attached to the object files. So we mark the entry attached to the
548 // object file as a forwarder, and record it in the forwarders_ map.
549 // Note that entries in the hash table will never be marked as
552 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
553 // symbol exactly as it existed in the input file. SYM is usually
554 // that as well, but can be modified, for instance if we determine
555 // it's in a to-be-discarded section.
557 template<int size
, bool big_endian
>
559 Symbol_table::add_from_object(Object
* object
,
561 Stringpool::Key name_key
,
563 Stringpool::Key version_key
,
565 const elfcpp::Sym
<size
, big_endian
>& sym
,
566 const elfcpp::Sym
<size
, big_endian
>& orig_sym
)
568 // Print a message if this symbol is being traced.
569 if (parameters
->options().is_trace_symbol(name
))
571 if (orig_sym
.get_st_shndx() == elfcpp::SHN_UNDEF
)
572 gold_info(_("%s: reference to %s"), object
->name().c_str(), name
);
574 gold_info(_("%s: definition of %s"), object
->name().c_str(), name
);
577 // For an undefined symbol, we may need to adjust the name using
579 if (orig_sym
.get_st_shndx() == elfcpp::SHN_UNDEF
580 && parameters
->options().any_wrap())
582 const char* wrap_name
= this->wrap_symbol(object
, name
, &name_key
);
583 if (wrap_name
!= name
)
585 // If we see a reference to malloc with version GLIBC_2.0,
586 // and we turn it into a reference to __wrap_malloc, then we
587 // discard the version number. Otherwise the user would be
588 // required to specify the correct version for
596 Symbol
* const snull
= NULL
;
597 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
598 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
601 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
602 std::make_pair(this->table_
.end(), false);
605 const Stringpool::Key vnull_key
= 0;
606 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
611 // ins.first: an iterator, which is a pointer to a pair.
612 // ins.first->first: the key (a pair of name and version).
613 // ins.first->second: the value (Symbol*).
614 // ins.second: true if new entry was inserted, false if not.
616 Sized_symbol
<size
>* ret
;
621 // We already have an entry for NAME/VERSION.
622 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
623 gold_assert(ret
!= NULL
);
625 was_undefined
= ret
->is_undefined();
626 was_common
= ret
->is_common();
628 this->resolve(ret
, sym
, orig_sym
, object
, version
);
634 // This is the first time we have seen NAME/NULL. Make
635 // NAME/NULL point to NAME/VERSION.
636 insdef
.first
->second
= ret
;
638 else if (insdef
.first
->second
!= ret
639 && insdef
.first
->second
->is_undefined())
641 // This is the unfortunate case where we already have
642 // entries for both NAME/VERSION and NAME/NULL. Note
643 // that we don't want to combine them if the existing
644 // symbol is going to override the new one. FIXME: We
645 // currently just test is_undefined, but this may not do
646 // the right thing if the existing symbol is from a
647 // shared library and the new one is from a regular
650 const Sized_symbol
<size
>* sym2
;
651 sym2
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
652 Symbol_table::resolve
<size
, big_endian
>(ret
, sym2
, version
);
653 this->make_forwarder(insdef
.first
->second
, ret
);
654 insdef
.first
->second
= ret
;
662 // This is the first time we have seen NAME/VERSION.
663 gold_assert(ins
.first
->second
== NULL
);
665 if (def
&& !insdef
.second
)
667 // We already have an entry for NAME/NULL. If we override
668 // it, then change it to NAME/VERSION.
669 ret
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
671 was_undefined
= ret
->is_undefined();
672 was_common
= ret
->is_common();
674 this->resolve(ret
, sym
, orig_sym
, object
, version
);
675 ins
.first
->second
= ret
;
679 was_undefined
= false;
682 Sized_target
<size
, big_endian
>* target
=
683 object
->sized_target
<size
, big_endian
>();
684 if (!target
->has_make_symbol())
685 ret
= new Sized_symbol
<size
>();
688 ret
= target
->make_symbol();
691 // This means that we don't want a symbol table
694 this->table_
.erase(ins
.first
);
697 this->table_
.erase(insdef
.first
);
698 // Inserting insdef invalidated ins.
699 this->table_
.erase(std::make_pair(name_key
,
706 ret
->init(name
, version
, object
, sym
);
708 ins
.first
->second
= ret
;
711 // This is the first time we have seen NAME/NULL. Point
712 // it at the new entry for NAME/VERSION.
713 gold_assert(insdef
.second
);
714 insdef
.first
->second
= ret
;
719 // Record every time we see a new undefined symbol, to speed up
721 if (!was_undefined
&& ret
->is_undefined())
722 ++this->saw_undefined_
;
724 // Keep track of common symbols, to speed up common symbol
726 if (!was_common
&& ret
->is_common())
728 if (ret
->type() != elfcpp::STT_TLS
)
729 this->commons_
.push_back(ret
);
731 this->tls_commons_
.push_back(ret
);
735 ret
->set_is_default();
739 // Add all the symbols in a relocatable object to the hash table.
741 template<int size
, bool big_endian
>
743 Symbol_table::add_from_relobj(
744 Sized_relobj
<size
, big_endian
>* relobj
,
745 const unsigned char* syms
,
747 const char* sym_names
,
748 size_t sym_name_size
,
749 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
)
751 gold_assert(size
== relobj
->target()->get_size());
752 gold_assert(size
== parameters
->target().get_size());
754 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
756 const bool just_symbols
= relobj
->just_symbols();
758 const unsigned char* p
= syms
;
759 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
761 elfcpp::Sym
<size
, big_endian
> sym(p
);
762 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
764 unsigned int st_name
= psym
->get_st_name();
765 if (st_name
>= sym_name_size
)
767 relobj
->error(_("bad global symbol name offset %u at %zu"),
772 const char* name
= sym_names
+ st_name
;
774 // A symbol defined in a section which we are not including must
775 // be treated as an undefined symbol.
776 unsigned char symbuf
[sym_size
];
777 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
778 unsigned int st_shndx
= psym
->get_st_shndx();
779 if (st_shndx
!= elfcpp::SHN_UNDEF
780 && st_shndx
< elfcpp::SHN_LORESERVE
781 && !relobj
->is_section_included(st_shndx
))
783 memcpy(symbuf
, p
, sym_size
);
784 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
785 sw
.put_st_shndx(elfcpp::SHN_UNDEF
);
789 // In an object file, an '@' in the name separates the symbol
790 // name from the version name. If there are two '@' characters,
791 // this is the default version.
792 const char* ver
= strchr(name
, '@');
794 // DEF: is the version default? LOCAL: is the symbol forced local?
800 // The symbol name is of the form foo@VERSION or foo@@VERSION
801 namelen
= ver
- name
;
809 // We don't want to assign a version to an undefined symbol,
810 // even if it is listed in the version script. FIXME: What
811 // about a common symbol?
812 else if (!version_script_
.empty()
813 && psym
->get_st_shndx() != elfcpp::SHN_UNDEF
)
815 // The symbol name did not have a version, but
816 // the version script may assign a version anyway.
817 namelen
= strlen(name
);
819 // Check the global: entries from the version script.
820 const std::string
& version
=
821 version_script_
.get_symbol_version(name
);
822 if (!version
.empty())
823 ver
= version
.c_str();
824 // Check the local: entries from the version script
825 if (version_script_
.symbol_is_local(name
))
832 memcpy(symbuf
, p
, sym_size
);
833 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
834 sw
.put_st_shndx(elfcpp::SHN_ABS
);
835 if (st_shndx
!= elfcpp::SHN_UNDEF
836 && st_shndx
< elfcpp::SHN_LORESERVE
)
838 // Symbol values in object files are section relative.
839 // This is normally what we want, but since here we are
840 // converting the symbol to absolute we need to add the
841 // section address. The section address in an object
842 // file is normally zero, but people can use a linker
843 // script to change it.
844 sw
.put_st_value(sym2
.get_st_value()
845 + relobj
->section_address(st_shndx
));
850 Sized_symbol
<size
>* res
;
853 Stringpool::Key name_key
;
854 name
= this->namepool_
.add(name
, true, &name_key
);
855 res
= this->add_from_object(relobj
, name
, name_key
, NULL
, 0,
858 this->force_local(res
);
862 Stringpool::Key name_key
;
863 name
= this->namepool_
.add_with_length(name
, namelen
, true,
865 Stringpool::Key ver_key
;
866 ver
= this->namepool_
.add(ver
, true, &ver_key
);
868 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
872 (*sympointers
)[i
] = res
;
876 // Add all the symbols in a dynamic object to the hash table.
878 template<int size
, bool big_endian
>
880 Symbol_table::add_from_dynobj(
881 Sized_dynobj
<size
, big_endian
>* dynobj
,
882 const unsigned char* syms
,
884 const char* sym_names
,
885 size_t sym_name_size
,
886 const unsigned char* versym
,
888 const std::vector
<const char*>* version_map
)
890 gold_assert(size
== dynobj
->target()->get_size());
891 gold_assert(size
== parameters
->target().get_size());
893 if (dynobj
->just_symbols())
895 gold_error(_("--just-symbols does not make sense with a shared object"));
899 if (versym
!= NULL
&& versym_size
/ 2 < count
)
901 dynobj
->error(_("too few symbol versions"));
905 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
907 // We keep a list of all STT_OBJECT symbols, so that we can resolve
908 // weak aliases. This is necessary because if the dynamic object
909 // provides the same variable under two names, one of which is a
910 // weak definition, and the regular object refers to the weak
911 // definition, we have to put both the weak definition and the
912 // strong definition into the dynamic symbol table. Given a weak
913 // definition, the only way that we can find the corresponding
914 // strong definition, if any, is to search the symbol table.
915 std::vector
<Sized_symbol
<size
>*> object_symbols
;
917 const unsigned char* p
= syms
;
918 const unsigned char* vs
= versym
;
919 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
921 elfcpp::Sym
<size
, big_endian
> sym(p
);
923 // Ignore symbols with local binding or that have
924 // internal or hidden visibility.
925 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
926 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
927 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
930 unsigned int st_name
= sym
.get_st_name();
931 if (st_name
>= sym_name_size
)
933 dynobj
->error(_("bad symbol name offset %u at %zu"),
938 const char* name
= sym_names
+ st_name
;
940 Sized_symbol
<size
>* res
;
944 Stringpool::Key name_key
;
945 name
= this->namepool_
.add(name
, true, &name_key
);
946 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
951 // Read the version information.
953 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
955 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
956 v
&= elfcpp::VERSYM_VERSION
;
958 // The Sun documentation says that V can be VER_NDX_LOCAL,
959 // or VER_NDX_GLOBAL, or a version index. The meaning of
960 // VER_NDX_LOCAL is defined as "Symbol has local scope."
961 // The old GNU linker will happily generate VER_NDX_LOCAL
962 // for an undefined symbol. I don't know what the Sun
963 // linker will generate.
965 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
966 && sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
968 // This symbol should not be visible outside the object.
972 // At this point we are definitely going to add this symbol.
973 Stringpool::Key name_key
;
974 name
= this->namepool_
.add(name
, true, &name_key
);
976 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
977 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
979 // This symbol does not have a version.
980 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
985 if (v
>= version_map
->size())
987 dynobj
->error(_("versym for symbol %zu out of range: %u"),
992 const char* version
= (*version_map
)[v
];
995 dynobj
->error(_("versym for symbol %zu has no name: %u"),
1000 Stringpool::Key version_key
;
1001 version
= this->namepool_
.add(version
, true, &version_key
);
1003 // If this is an absolute symbol, and the version name
1004 // and symbol name are the same, then this is the
1005 // version definition symbol. These symbols exist to
1006 // support using -u to pull in particular versions. We
1007 // do not want to record a version for them.
1008 if (sym
.get_st_shndx() == elfcpp::SHN_ABS
1009 && name_key
== version_key
)
1010 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1014 const bool def
= (!hidden
1015 && (sym
.get_st_shndx()
1016 != elfcpp::SHN_UNDEF
));
1017 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
1018 version_key
, def
, sym
, sym
);
1023 // Note that it is possible that RES was overridden by an
1024 // earlier object, in which case it can't be aliased here.
1025 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
1026 && sym
.get_st_type() == elfcpp::STT_OBJECT
1027 && res
->source() == Symbol::FROM_OBJECT
1028 && res
->object() == dynobj
)
1029 object_symbols
.push_back(res
);
1032 this->record_weak_aliases(&object_symbols
);
1035 // This is used to sort weak aliases. We sort them first by section
1036 // index, then by offset, then by weak ahead of strong.
1039 class Weak_alias_sorter
1042 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
1047 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
1048 const Sized_symbol
<size
>* s2
) const
1050 if (s1
->shndx() != s2
->shndx())
1051 return s1
->shndx() < s2
->shndx();
1052 if (s1
->value() != s2
->value())
1053 return s1
->value() < s2
->value();
1054 if (s1
->binding() != s2
->binding())
1056 if (s1
->binding() == elfcpp::STB_WEAK
)
1058 if (s2
->binding() == elfcpp::STB_WEAK
)
1061 return std::string(s1
->name()) < std::string(s2
->name());
1064 // SYMBOLS is a list of object symbols from a dynamic object. Look
1065 // for any weak aliases, and record them so that if we add the weak
1066 // alias to the dynamic symbol table, we also add the corresponding
1071 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
1073 // Sort the vector by section index, then by offset, then by weak
1075 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
1077 // Walk through the vector. For each weak definition, record
1079 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
1081 p
!= symbols
->end();
1084 if ((*p
)->binding() != elfcpp::STB_WEAK
)
1087 // Build a circular list of weak aliases. Each symbol points to
1088 // the next one in the circular list.
1090 Sized_symbol
<size
>* from_sym
= *p
;
1091 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
1092 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
1094 if ((*q
)->shndx() != from_sym
->shndx()
1095 || (*q
)->value() != from_sym
->value())
1098 this->weak_aliases_
[from_sym
] = *q
;
1099 from_sym
->set_has_alias();
1105 this->weak_aliases_
[from_sym
] = *p
;
1106 from_sym
->set_has_alias();
1113 // Create and return a specially defined symbol. If ONLY_IF_REF is
1114 // true, then only create the symbol if there is a reference to it.
1115 // If this does not return NULL, it sets *POLDSYM to the existing
1116 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1118 template<int size
, bool big_endian
>
1120 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1122 Sized_symbol
<size
>** poldsym
)
1125 Sized_symbol
<size
>* sym
;
1126 bool add_to_table
= false;
1127 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1129 // If the caller didn't give us a version, see if we get one from
1130 // the version script.
1131 if (*pversion
== NULL
)
1133 const std::string
& v(this->version_script_
.get_symbol_version(*pname
));
1135 *pversion
= v
.c_str();
1140 oldsym
= this->lookup(*pname
, *pversion
);
1141 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1144 *pname
= oldsym
->name();
1145 *pversion
= oldsym
->version();
1149 // Canonicalize NAME and VERSION.
1150 Stringpool::Key name_key
;
1151 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1153 Stringpool::Key version_key
= 0;
1154 if (*pversion
!= NULL
)
1155 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1157 Symbol
* const snull
= NULL
;
1158 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1159 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1165 // We already have a symbol table entry for NAME/VERSION.
1166 oldsym
= ins
.first
->second
;
1167 gold_assert(oldsym
!= NULL
);
1171 // We haven't seen this symbol before.
1172 gold_assert(ins
.first
->second
== NULL
);
1173 add_to_table
= true;
1174 add_loc
= ins
.first
;
1179 const Target
& target
= parameters
->target();
1180 if (!target
.has_make_symbol())
1181 sym
= new Sized_symbol
<size
>();
1184 gold_assert(target
.get_size() == size
);
1185 gold_assert(target
.is_big_endian() ? big_endian
: !big_endian
);
1186 typedef Sized_target
<size
, big_endian
> My_target
;
1187 const My_target
* sized_target
=
1188 static_cast<const My_target
*>(&target
);
1189 sym
= sized_target
->make_symbol();
1195 add_loc
->second
= sym
;
1197 gold_assert(oldsym
!= NULL
);
1199 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1204 // Define a symbol based on an Output_data.
1207 Symbol_table::define_in_output_data(const char* name
,
1208 const char* version
,
1213 elfcpp::STB binding
,
1214 elfcpp::STV visibility
,
1215 unsigned char nonvis
,
1216 bool offset_is_from_end
,
1219 if (parameters
->target().get_size() == 32)
1221 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1222 return this->do_define_in_output_data
<32>(name
, version
, od
,
1223 value
, symsize
, type
, binding
,
1231 else if (parameters
->target().get_size() == 64)
1233 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1234 return this->do_define_in_output_data
<64>(name
, version
, od
,
1235 value
, symsize
, type
, binding
,
1247 // Define a symbol in an Output_data, sized version.
1251 Symbol_table::do_define_in_output_data(
1253 const char* version
,
1255 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1256 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1258 elfcpp::STB binding
,
1259 elfcpp::STV visibility
,
1260 unsigned char nonvis
,
1261 bool offset_is_from_end
,
1264 Sized_symbol
<size
>* sym
;
1265 Sized_symbol
<size
>* oldsym
;
1267 if (parameters
->target().is_big_endian())
1269 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1270 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1271 only_if_ref
, &oldsym
);
1278 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1279 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1280 only_if_ref
, &oldsym
);
1289 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1290 sym
->init(name
, od
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1291 offset_is_from_end
);
1295 if (binding
== elfcpp::STB_LOCAL
1296 || this->version_script_
.symbol_is_local(name
))
1297 this->force_local(sym
);
1301 if (Symbol_table::should_override_with_special(oldsym
))
1302 this->override_with_special(oldsym
, sym
);
1307 // Define a symbol based on an Output_segment.
1310 Symbol_table::define_in_output_segment(const char* name
,
1311 const char* version
, Output_segment
* os
,
1315 elfcpp::STB binding
,
1316 elfcpp::STV visibility
,
1317 unsigned char nonvis
,
1318 Symbol::Segment_offset_base offset_base
,
1321 if (parameters
->target().get_size() == 32)
1323 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1324 return this->do_define_in_output_segment
<32>(name
, version
, os
,
1325 value
, symsize
, type
,
1326 binding
, visibility
, nonvis
,
1327 offset_base
, only_if_ref
);
1332 else if (parameters
->target().get_size() == 64)
1334 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1335 return this->do_define_in_output_segment
<64>(name
, version
, os
,
1336 value
, symsize
, type
,
1337 binding
, visibility
, nonvis
,
1338 offset_base
, only_if_ref
);
1347 // Define a symbol in an Output_segment, sized version.
1351 Symbol_table::do_define_in_output_segment(
1353 const char* version
,
1355 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1356 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1358 elfcpp::STB binding
,
1359 elfcpp::STV visibility
,
1360 unsigned char nonvis
,
1361 Symbol::Segment_offset_base offset_base
,
1364 Sized_symbol
<size
>* sym
;
1365 Sized_symbol
<size
>* oldsym
;
1367 if (parameters
->target().is_big_endian())
1369 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1370 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1371 only_if_ref
, &oldsym
);
1378 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1379 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1380 only_if_ref
, &oldsym
);
1389 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1390 sym
->init(name
, os
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1395 if (binding
== elfcpp::STB_LOCAL
1396 || this->version_script_
.symbol_is_local(name
))
1397 this->force_local(sym
);
1401 if (Symbol_table::should_override_with_special(oldsym
))
1402 this->override_with_special(oldsym
, sym
);
1407 // Define a special symbol with a constant value. It is a multiple
1408 // definition error if this symbol is already defined.
1411 Symbol_table::define_as_constant(const char* name
,
1412 const char* version
,
1416 elfcpp::STB binding
,
1417 elfcpp::STV visibility
,
1418 unsigned char nonvis
,
1420 bool force_override
)
1422 if (parameters
->target().get_size() == 32)
1424 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1425 return this->do_define_as_constant
<32>(name
, version
, value
,
1426 symsize
, type
, binding
,
1427 visibility
, nonvis
, only_if_ref
,
1433 else if (parameters
->target().get_size() == 64)
1435 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1436 return this->do_define_as_constant
<64>(name
, version
, value
,
1437 symsize
, type
, binding
,
1438 visibility
, nonvis
, only_if_ref
,
1448 // Define a symbol as a constant, sized version.
1452 Symbol_table::do_define_as_constant(
1454 const char* version
,
1455 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1456 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1458 elfcpp::STB binding
,
1459 elfcpp::STV visibility
,
1460 unsigned char nonvis
,
1462 bool force_override
)
1464 Sized_symbol
<size
>* sym
;
1465 Sized_symbol
<size
>* oldsym
;
1467 if (parameters
->target().is_big_endian())
1469 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1470 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1471 only_if_ref
, &oldsym
);
1478 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1479 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1480 only_if_ref
, &oldsym
);
1489 gold_assert(version
== NULL
|| version
== name
|| oldsym
!= NULL
);
1490 sym
->init(name
, value
, symsize
, type
, binding
, visibility
, nonvis
);
1494 // Version symbols are absolute symbols with name == version.
1495 // We don't want to force them to be local.
1496 if ((version
== NULL
1499 && (binding
== elfcpp::STB_LOCAL
1500 || this->version_script_
.symbol_is_local(name
)))
1501 this->force_local(sym
);
1505 if (force_override
|| Symbol_table::should_override_with_special(oldsym
))
1506 this->override_with_special(oldsym
, sym
);
1511 // Define a set of symbols in output sections.
1514 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1515 const Define_symbol_in_section
* p
,
1518 for (int i
= 0; i
< count
; ++i
, ++p
)
1520 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1522 this->define_in_output_data(p
->name
, NULL
, os
, p
->value
,
1523 p
->size
, p
->type
, p
->binding
,
1524 p
->visibility
, p
->nonvis
,
1525 p
->offset_is_from_end
,
1526 only_if_ref
|| p
->only_if_ref
);
1528 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1529 p
->binding
, p
->visibility
, p
->nonvis
,
1530 only_if_ref
|| p
->only_if_ref
,
1535 // Define a set of symbols in output segments.
1538 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1539 const Define_symbol_in_segment
* p
,
1542 for (int i
= 0; i
< count
; ++i
, ++p
)
1544 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1545 p
->segment_flags_set
,
1546 p
->segment_flags_clear
);
1548 this->define_in_output_segment(p
->name
, NULL
, os
, p
->value
,
1549 p
->size
, p
->type
, p
->binding
,
1550 p
->visibility
, p
->nonvis
,
1552 only_if_ref
|| p
->only_if_ref
);
1554 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1555 p
->binding
, p
->visibility
, p
->nonvis
,
1556 only_if_ref
|| p
->only_if_ref
,
1561 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1562 // symbol should be defined--typically a .dyn.bss section. VALUE is
1563 // the offset within POSD.
1567 Symbol_table::define_with_copy_reloc(
1568 Sized_symbol
<size
>* csym
,
1570 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1572 gold_assert(csym
->is_from_dynobj());
1573 gold_assert(!csym
->is_copied_from_dynobj());
1574 Object
* object
= csym
->object();
1575 gold_assert(object
->is_dynamic());
1576 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1578 // Our copied variable has to override any variable in a shared
1580 elfcpp::STB binding
= csym
->binding();
1581 if (binding
== elfcpp::STB_WEAK
)
1582 binding
= elfcpp::STB_GLOBAL
;
1584 this->define_in_output_data(csym
->name(), csym
->version(),
1585 posd
, value
, csym
->symsize(),
1586 csym
->type(), binding
,
1587 csym
->visibility(), csym
->nonvis(),
1590 csym
->set_is_copied_from_dynobj();
1591 csym
->set_needs_dynsym_entry();
1593 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1595 // We have now defined all aliases, but we have not entered them all
1596 // in the copied_symbol_dynobjs_ map.
1597 if (csym
->has_alias())
1602 sym
= this->weak_aliases_
[sym
];
1605 gold_assert(sym
->output_data() == posd
);
1607 sym
->set_is_copied_from_dynobj();
1608 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1613 // SYM is defined using a COPY reloc. Return the dynamic object where
1614 // the original definition was found.
1617 Symbol_table::get_copy_source(const Symbol
* sym
) const
1619 gold_assert(sym
->is_copied_from_dynobj());
1620 Copied_symbol_dynobjs::const_iterator p
=
1621 this->copied_symbol_dynobjs_
.find(sym
);
1622 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1626 // Set the dynamic symbol indexes. INDEX is the index of the first
1627 // global dynamic symbol. Pointers to the symbols are stored into the
1628 // vector SYMS. The names are added to DYNPOOL. This returns an
1629 // updated dynamic symbol index.
1632 Symbol_table::set_dynsym_indexes(unsigned int index
,
1633 std::vector
<Symbol
*>* syms
,
1634 Stringpool
* dynpool
,
1637 for (Symbol_table_type::iterator p
= this->table_
.begin();
1638 p
!= this->table_
.end();
1641 Symbol
* sym
= p
->second
;
1643 // Note that SYM may already have a dynamic symbol index, since
1644 // some symbols appear more than once in the symbol table, with
1645 // and without a version.
1647 if (!sym
->should_add_dynsym_entry())
1648 sym
->set_dynsym_index(-1U);
1649 else if (!sym
->has_dynsym_index())
1651 sym
->set_dynsym_index(index
);
1653 syms
->push_back(sym
);
1654 dynpool
->add(sym
->name(), false, NULL
);
1656 // Record any version information.
1657 if (sym
->version() != NULL
)
1658 versions
->record_version(this, dynpool
, sym
);
1662 // Finish up the versions. In some cases this may add new dynamic
1664 index
= versions
->finalize(this, index
, syms
);
1669 // Set the final values for all the symbols. The index of the first
1670 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1671 // file offset OFF. Add their names to POOL. Return the new file
1672 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1675 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
1676 size_t dyncount
, Stringpool
* pool
,
1677 unsigned int *plocal_symcount
)
1681 gold_assert(*plocal_symcount
!= 0);
1682 this->first_global_index_
= *plocal_symcount
;
1684 this->dynamic_offset_
= dynoff
;
1685 this->first_dynamic_global_index_
= dyn_global_index
;
1686 this->dynamic_count_
= dyncount
;
1688 if (parameters
->target().get_size() == 32)
1690 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1691 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
1696 else if (parameters
->target().get_size() == 64)
1698 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1699 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
1707 // Now that we have the final symbol table, we can reliably note
1708 // which symbols should get warnings.
1709 this->warnings_
.note_warnings(this);
1714 // SYM is going into the symbol table at *PINDEX. Add the name to
1715 // POOL, update *PINDEX and *POFF.
1719 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
1720 unsigned int* pindex
, off_t
* poff
)
1722 sym
->set_symtab_index(*pindex
);
1723 pool
->add(sym
->name(), false, NULL
);
1725 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
1728 // Set the final value for all the symbols. This is called after
1729 // Layout::finalize, so all the output sections have their final
1734 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
1735 unsigned int* plocal_symcount
)
1737 off
= align_address(off
, size
>> 3);
1738 this->offset_
= off
;
1740 unsigned int index
= *plocal_symcount
;
1741 const unsigned int orig_index
= index
;
1743 // First do all the symbols which have been forced to be local, as
1744 // they must appear before all global symbols.
1745 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
1746 p
!= this->forced_locals_
.end();
1750 gold_assert(sym
->is_forced_local());
1751 if (this->sized_finalize_symbol
<size
>(sym
))
1753 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1758 // Now do all the remaining symbols.
1759 for (Symbol_table_type::iterator p
= this->table_
.begin();
1760 p
!= this->table_
.end();
1763 Symbol
* sym
= p
->second
;
1764 if (this->sized_finalize_symbol
<size
>(sym
))
1765 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1768 this->output_count_
= index
- orig_index
;
1773 // Finalize the symbol SYM. This returns true if the symbol should be
1774 // added to the symbol table, false otherwise.
1778 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
1780 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
1782 // The default version of a symbol may appear twice in the symbol
1783 // table. We only need to finalize it once.
1784 if (sym
->has_symtab_index())
1789 gold_assert(!sym
->has_symtab_index());
1790 sym
->set_symtab_index(-1U);
1791 gold_assert(sym
->dynsym_index() == -1U);
1795 typename Sized_symbol
<size
>::Value_type value
;
1797 switch (sym
->source())
1799 case Symbol::FROM_OBJECT
:
1801 unsigned int shndx
= sym
->shndx();
1803 // FIXME: We need some target specific support here.
1804 if (shndx
>= elfcpp::SHN_LORESERVE
1805 && shndx
!= elfcpp::SHN_ABS
1806 && shndx
!= elfcpp::SHN_COMMON
)
1808 gold_error(_("%s: unsupported symbol section 0x%x"),
1809 sym
->demangled_name().c_str(), shndx
);
1810 shndx
= elfcpp::SHN_UNDEF
;
1813 Object
* symobj
= sym
->object();
1814 if (symobj
->is_dynamic())
1817 shndx
= elfcpp::SHN_UNDEF
;
1819 else if (shndx
== elfcpp::SHN_UNDEF
)
1821 else if (shndx
== elfcpp::SHN_ABS
|| shndx
== elfcpp::SHN_COMMON
)
1822 value
= sym
->value();
1825 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1826 section_offset_type secoff
;
1827 Output_section
* os
= relobj
->output_section(shndx
, &secoff
);
1831 sym
->set_symtab_index(-1U);
1832 gold_assert(sym
->dynsym_index() == -1U);
1836 if (sym
->type() == elfcpp::STT_TLS
)
1837 value
= sym
->value() + os
->tls_offset() + secoff
;
1839 value
= sym
->value() + os
->address() + secoff
;
1844 case Symbol::IN_OUTPUT_DATA
:
1846 Output_data
* od
= sym
->output_data();
1847 value
= sym
->value();
1848 if (sym
->type() != elfcpp::STT_TLS
)
1849 value
+= od
->address();
1852 Output_section
* os
= od
->output_section();
1853 gold_assert(os
!= NULL
);
1854 value
+= os
->tls_offset() + (od
->address() - os
->address());
1856 if (sym
->offset_is_from_end())
1857 value
+= od
->data_size();
1861 case Symbol::IN_OUTPUT_SEGMENT
:
1863 Output_segment
* os
= sym
->output_segment();
1864 value
= sym
->value();
1865 if (sym
->type() != elfcpp::STT_TLS
)
1866 value
+= os
->vaddr();
1867 switch (sym
->offset_base())
1869 case Symbol::SEGMENT_START
:
1871 case Symbol::SEGMENT_END
:
1872 value
+= os
->memsz();
1874 case Symbol::SEGMENT_BSS
:
1875 value
+= os
->filesz();
1883 case Symbol::CONSTANT
:
1884 value
= sym
->value();
1891 sym
->set_value(value
);
1893 if (parameters
->options().strip_all())
1895 sym
->set_symtab_index(-1U);
1902 // Write out the global symbols.
1905 Symbol_table::write_globals(const Input_objects
* input_objects
,
1906 const Stringpool
* sympool
,
1907 const Stringpool
* dynpool
, Output_file
* of
) const
1909 switch (parameters
->size_and_endianness())
1911 #ifdef HAVE_TARGET_32_LITTLE
1912 case Parameters::TARGET_32_LITTLE
:
1913 this->sized_write_globals
<32, false>(input_objects
, sympool
,
1917 #ifdef HAVE_TARGET_32_BIG
1918 case Parameters::TARGET_32_BIG
:
1919 this->sized_write_globals
<32, true>(input_objects
, sympool
,
1923 #ifdef HAVE_TARGET_64_LITTLE
1924 case Parameters::TARGET_64_LITTLE
:
1925 this->sized_write_globals
<64, false>(input_objects
, sympool
,
1929 #ifdef HAVE_TARGET_64_BIG
1930 case Parameters::TARGET_64_BIG
:
1931 this->sized_write_globals
<64, true>(input_objects
, sympool
,
1940 // Write out the global symbols.
1942 template<int size
, bool big_endian
>
1944 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
1945 const Stringpool
* sympool
,
1946 const Stringpool
* dynpool
,
1947 Output_file
* of
) const
1949 const Target
& target
= parameters
->target();
1951 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1953 const unsigned int output_count
= this->output_count_
;
1954 const section_size_type oview_size
= output_count
* sym_size
;
1955 const unsigned int first_global_index
= this->first_global_index_
;
1956 unsigned char* psyms
;
1957 if (this->offset_
== 0 || output_count
== 0)
1960 psyms
= of
->get_output_view(this->offset_
, oview_size
);
1962 const unsigned int dynamic_count
= this->dynamic_count_
;
1963 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
1964 const unsigned int first_dynamic_global_index
=
1965 this->first_dynamic_global_index_
;
1966 unsigned char* dynamic_view
;
1967 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
1968 dynamic_view
= NULL
;
1970 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
1972 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1973 p
!= this->table_
.end();
1976 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1978 // Possibly warn about unresolved symbols in shared libraries.
1979 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
1981 unsigned int sym_index
= sym
->symtab_index();
1982 unsigned int dynsym_index
;
1983 if (dynamic_view
== NULL
)
1986 dynsym_index
= sym
->dynsym_index();
1988 if (sym_index
== -1U && dynsym_index
== -1U)
1990 // This symbol is not included in the output file.
1995 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
1996 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
1997 switch (sym
->source())
1999 case Symbol::FROM_OBJECT
:
2001 unsigned int in_shndx
= sym
->shndx();
2003 // FIXME: We need some target specific support here.
2004 if (in_shndx
>= elfcpp::SHN_LORESERVE
2005 && in_shndx
!= elfcpp::SHN_ABS
2006 && in_shndx
!= elfcpp::SHN_COMMON
)
2008 gold_error(_("%s: unsupported symbol section 0x%x"),
2009 sym
->demangled_name().c_str(), in_shndx
);
2014 Object
* symobj
= sym
->object();
2015 if (symobj
->is_dynamic())
2017 if (sym
->needs_dynsym_value())
2018 dynsym_value
= target
.dynsym_value(sym
);
2019 shndx
= elfcpp::SHN_UNDEF
;
2021 else if (in_shndx
== elfcpp::SHN_UNDEF
2022 || in_shndx
== elfcpp::SHN_ABS
2023 || in_shndx
== elfcpp::SHN_COMMON
)
2027 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
2028 section_offset_type secoff
;
2029 Output_section
* os
= relobj
->output_section(in_shndx
,
2031 gold_assert(os
!= NULL
);
2032 shndx
= os
->out_shndx();
2034 // In object files symbol values are section
2036 if (parameters
->options().relocatable())
2037 sym_value
-= os
->address();
2043 case Symbol::IN_OUTPUT_DATA
:
2044 shndx
= sym
->output_data()->out_shndx();
2047 case Symbol::IN_OUTPUT_SEGMENT
:
2048 shndx
= elfcpp::SHN_ABS
;
2051 case Symbol::CONSTANT
:
2052 shndx
= elfcpp::SHN_ABS
;
2059 if (sym_index
!= -1U)
2061 sym_index
-= first_global_index
;
2062 gold_assert(sym_index
< output_count
);
2063 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
2064 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
2068 if (dynsym_index
!= -1U)
2070 dynsym_index
-= first_dynamic_global_index
;
2071 gold_assert(dynsym_index
< dynamic_count
);
2072 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
2073 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
2078 of
->write_output_view(this->offset_
, oview_size
, psyms
);
2079 if (dynamic_view
!= NULL
)
2080 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
2083 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2084 // strtab holding the name.
2086 template<int size
, bool big_endian
>
2088 Symbol_table::sized_write_symbol(
2089 Sized_symbol
<size
>* sym
,
2090 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
2092 const Stringpool
* pool
,
2093 unsigned char* p
) const
2095 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
2096 osym
.put_st_name(pool
->get_offset(sym
->name()));
2097 osym
.put_st_value(value
);
2098 osym
.put_st_size(sym
->symsize());
2099 // A version script may have overridden the default binding.
2100 if (sym
->is_forced_local())
2101 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, sym
->type()));
2103 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
2104 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
2105 osym
.put_st_shndx(shndx
);
2108 // Check for unresolved symbols in shared libraries. This is
2109 // controlled by the --allow-shlib-undefined option.
2111 // We only warn about libraries for which we have seen all the
2112 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2113 // which were not seen in this link. If we didn't see a DT_NEEDED
2114 // entry, we aren't going to be able to reliably report whether the
2115 // symbol is undefined.
2117 // We also don't warn about libraries found in the system library
2118 // directory (the directory were we find libc.so); we assume that
2119 // those libraries are OK. This heuristic avoids problems in
2120 // GNU/Linux, in which -ldl can have undefined references satisfied by
2124 Symbol_table::warn_about_undefined_dynobj_symbol(
2125 const Input_objects
* input_objects
,
2128 if (sym
->source() == Symbol::FROM_OBJECT
2129 && sym
->object()->is_dynamic()
2130 && sym
->shndx() == elfcpp::SHN_UNDEF
2131 && sym
->binding() != elfcpp::STB_WEAK
2132 && !parameters
->options().allow_shlib_undefined()
2133 && !parameters
->target().is_defined_by_abi(sym
)
2134 && !input_objects
->found_in_system_library_directory(sym
->object()))
2136 // A very ugly cast.
2137 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
2138 if (!dynobj
->has_unknown_needed_entries())
2139 gold_error(_("%s: undefined reference to '%s'"),
2140 sym
->object()->name().c_str(),
2141 sym
->demangled_name().c_str());
2145 // Write out a section symbol. Return the update offset.
2148 Symbol_table::write_section_symbol(const Output_section
*os
,
2152 switch (parameters
->size_and_endianness())
2154 #ifdef HAVE_TARGET_32_LITTLE
2155 case Parameters::TARGET_32_LITTLE
:
2156 this->sized_write_section_symbol
<32, false>(os
, of
, offset
);
2159 #ifdef HAVE_TARGET_32_BIG
2160 case Parameters::TARGET_32_BIG
:
2161 this->sized_write_section_symbol
<32, true>(os
, of
, offset
);
2164 #ifdef HAVE_TARGET_64_LITTLE
2165 case Parameters::TARGET_64_LITTLE
:
2166 this->sized_write_section_symbol
<64, false>(os
, of
, offset
);
2169 #ifdef HAVE_TARGET_64_BIG
2170 case Parameters::TARGET_64_BIG
:
2171 this->sized_write_section_symbol
<64, true>(os
, of
, offset
);
2179 // Write out a section symbol, specialized for size and endianness.
2181 template<int size
, bool big_endian
>
2183 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
2187 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2189 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
2191 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
2192 osym
.put_st_name(0);
2193 osym
.put_st_value(os
->address());
2194 osym
.put_st_size(0);
2195 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
2196 elfcpp::STT_SECTION
));
2197 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
2198 osym
.put_st_shndx(os
->out_shndx());
2200 of
->write_output_view(offset
, sym_size
, pov
);
2203 // Print statistical information to stderr. This is used for --stats.
2206 Symbol_table::print_stats() const
2208 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2209 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2210 program_name
, this->table_
.size(), this->table_
.bucket_count());
2212 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
2213 program_name
, this->table_
.size());
2215 this->namepool_
.print_stats("symbol table stringpool");
2218 // We check for ODR violations by looking for symbols with the same
2219 // name for which the debugging information reports that they were
2220 // defined in different source locations. When comparing the source
2221 // location, we consider instances with the same base filename and
2222 // line number to be the same. This is because different object
2223 // files/shared libraries can include the same header file using
2224 // different paths, and we don't want to report an ODR violation in
2227 // This struct is used to compare line information, as returned by
2228 // Dwarf_line_info::one_addr2line. It implements a < comparison
2229 // operator used with std::set.
2231 struct Odr_violation_compare
2234 operator()(const std::string
& s1
, const std::string
& s2
) const
2236 std::string::size_type pos1
= s1
.rfind('/');
2237 std::string::size_type pos2
= s2
.rfind('/');
2238 if (pos1
== std::string::npos
2239 || pos2
== std::string::npos
)
2241 return s1
.compare(pos1
, std::string::npos
,
2242 s2
, pos2
, std::string::npos
) < 0;
2246 // Check candidate_odr_violations_ to find symbols with the same name
2247 // but apparently different definitions (different source-file/line-no).
2250 Symbol_table::detect_odr_violations(const Task
* task
,
2251 const char* output_file_name
) const
2253 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
2254 it
!= candidate_odr_violations_
.end();
2257 const char* symbol_name
= it
->first
;
2258 // We use a sorted set so the output is deterministic.
2259 std::set
<std::string
, Odr_violation_compare
> line_nums
;
2261 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
2262 locs
= it
->second
.begin();
2263 locs
!= it
->second
.end();
2266 // We need to lock the object in order to read it. This
2267 // means that we have to run in a singleton Task. If we
2268 // want to run this in a general Task for better
2269 // performance, we will need one Task for object, plus
2270 // appropriate locking to ensure that we don't conflict with
2271 // other uses of the object.
2272 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2273 std::string lineno
= Dwarf_line_info::one_addr2line(
2274 locs
->object
, locs
->shndx
, locs
->offset
);
2275 if (!lineno
.empty())
2276 line_nums
.insert(lineno
);
2279 if (line_nums
.size() > 1)
2281 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2282 "places (possible ODR violation):"),
2283 output_file_name
, demangle(symbol_name
).c_str());
2284 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2285 it2
!= line_nums
.end();
2287 fprintf(stderr
, " %s\n", it2
->c_str());
2292 // Warnings functions.
2294 // Add a new warning.
2297 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2298 const std::string
& warning
)
2300 name
= symtab
->canonicalize_name(name
);
2301 this->warnings_
[name
].set(obj
, warning
);
2304 // Look through the warnings and mark the symbols for which we should
2305 // warn. This is called during Layout::finalize when we know the
2306 // sources for all the symbols.
2309 Warnings::note_warnings(Symbol_table
* symtab
)
2311 for (Warning_table::iterator p
= this->warnings_
.begin();
2312 p
!= this->warnings_
.end();
2315 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2317 && sym
->source() == Symbol::FROM_OBJECT
2318 && sym
->object() == p
->second
.object
)
2319 sym
->set_has_warning();
2323 // Issue a warning. This is called when we see a relocation against a
2324 // symbol for which has a warning.
2326 template<int size
, bool big_endian
>
2328 Warnings::issue_warning(const Symbol
* sym
,
2329 const Relocate_info
<size
, big_endian
>* relinfo
,
2330 size_t relnum
, off_t reloffset
) const
2332 gold_assert(sym
->has_warning());
2333 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2334 gold_assert(p
!= this->warnings_
.end());
2335 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2336 "%s", p
->second
.text
.c_str());
2339 // Instantiate the templates we need. We could use the configure
2340 // script to restrict this to only the ones needed for implemented
2343 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2346 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2349 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2352 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2355 #ifdef HAVE_TARGET_32_LITTLE
2358 Symbol_table::add_from_relobj
<32, false>(
2359 Sized_relobj
<32, false>* relobj
,
2360 const unsigned char* syms
,
2362 const char* sym_names
,
2363 size_t sym_name_size
,
2364 Sized_relobj
<32, true>::Symbols
* sympointers
);
2367 #ifdef HAVE_TARGET_32_BIG
2370 Symbol_table::add_from_relobj
<32, true>(
2371 Sized_relobj
<32, true>* relobj
,
2372 const unsigned char* syms
,
2374 const char* sym_names
,
2375 size_t sym_name_size
,
2376 Sized_relobj
<32, false>::Symbols
* sympointers
);
2379 #ifdef HAVE_TARGET_64_LITTLE
2382 Symbol_table::add_from_relobj
<64, false>(
2383 Sized_relobj
<64, false>* relobj
,
2384 const unsigned char* syms
,
2386 const char* sym_names
,
2387 size_t sym_name_size
,
2388 Sized_relobj
<64, true>::Symbols
* sympointers
);
2391 #ifdef HAVE_TARGET_64_BIG
2394 Symbol_table::add_from_relobj
<64, true>(
2395 Sized_relobj
<64, true>* relobj
,
2396 const unsigned char* syms
,
2398 const char* sym_names
,
2399 size_t sym_name_size
,
2400 Sized_relobj
<64, false>::Symbols
* sympointers
);
2403 #ifdef HAVE_TARGET_32_LITTLE
2406 Symbol_table::add_from_dynobj
<32, false>(
2407 Sized_dynobj
<32, false>* dynobj
,
2408 const unsigned char* syms
,
2410 const char* sym_names
,
2411 size_t sym_name_size
,
2412 const unsigned char* versym
,
2414 const std::vector
<const char*>* version_map
);
2417 #ifdef HAVE_TARGET_32_BIG
2420 Symbol_table::add_from_dynobj
<32, true>(
2421 Sized_dynobj
<32, true>* dynobj
,
2422 const unsigned char* syms
,
2424 const char* sym_names
,
2425 size_t sym_name_size
,
2426 const unsigned char* versym
,
2428 const std::vector
<const char*>* version_map
);
2431 #ifdef HAVE_TARGET_64_LITTLE
2434 Symbol_table::add_from_dynobj
<64, false>(
2435 Sized_dynobj
<64, false>* dynobj
,
2436 const unsigned char* syms
,
2438 const char* sym_names
,
2439 size_t sym_name_size
,
2440 const unsigned char* versym
,
2442 const std::vector
<const char*>* version_map
);
2445 #ifdef HAVE_TARGET_64_BIG
2448 Symbol_table::add_from_dynobj
<64, true>(
2449 Sized_dynobj
<64, true>* dynobj
,
2450 const unsigned char* syms
,
2452 const char* sym_names
,
2453 size_t sym_name_size
,
2454 const unsigned char* versym
,
2456 const std::vector
<const char*>* version_map
);
2459 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2462 Symbol_table::define_with_copy_reloc
<32>(
2463 Sized_symbol
<32>* sym
,
2465 elfcpp::Elf_types
<32>::Elf_Addr value
);
2468 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2471 Symbol_table::define_with_copy_reloc
<64>(
2472 Sized_symbol
<64>* sym
,
2474 elfcpp::Elf_types
<64>::Elf_Addr value
);
2477 #ifdef HAVE_TARGET_32_LITTLE
2480 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
2481 const Relocate_info
<32, false>* relinfo
,
2482 size_t relnum
, off_t reloffset
) const;
2485 #ifdef HAVE_TARGET_32_BIG
2488 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
2489 const Relocate_info
<32, true>* relinfo
,
2490 size_t relnum
, off_t reloffset
) const;
2493 #ifdef HAVE_TARGET_64_LITTLE
2496 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
2497 const Relocate_info
<64, false>* relinfo
,
2498 size_t relnum
, off_t reloffset
) const;
2501 #ifdef HAVE_TARGET_64_BIG
2504 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
2505 const Relocate_info
<64, true>* relinfo
,
2506 size_t relnum
, off_t reloffset
) const;
2509 } // End namespace gold.