1 // symtab.cc -- the gold symbol table
3 // Copyright (C) 2006-2015 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.
35 #include "dwarf_reader.h"
39 #include "workqueue.h"
43 #include "incremental.h"
50 // Initialize fields in Symbol. This initializes everything except u_
54 Symbol::init_fields(const char* name
, const char* version
,
55 elfcpp::STT type
, elfcpp::STB binding
,
56 elfcpp::STV visibility
, unsigned char nonvis
)
59 this->version_
= version
;
60 this->symtab_index_
= 0;
61 this->dynsym_index_
= 0;
62 this->got_offsets_
.init();
63 this->plt_offset_
= -1U;
65 this->binding_
= binding
;
66 this->visibility_
= visibility
;
67 this->nonvis_
= nonvis
;
68 this->is_def_
= false;
69 this->is_forwarder_
= false;
70 this->has_alias_
= false;
71 this->needs_dynsym_entry_
= false;
72 this->in_reg_
= false;
73 this->in_dyn_
= false;
74 this->has_warning_
= false;
75 this->is_copied_from_dynobj_
= false;
76 this->is_forced_local_
= false;
77 this->is_ordinary_shndx_
= false;
78 this->in_real_elf_
= false;
79 this->is_defined_in_discarded_section_
= false;
80 this->undef_binding_set_
= false;
81 this->undef_binding_weak_
= false;
82 this->is_predefined_
= false;
85 // Return the demangled version of the symbol's name, but only
86 // if the --demangle flag was set.
89 demangle(const char* name
)
91 if (!parameters
->options().do_demangle())
94 // cplus_demangle allocates memory for the result it returns,
95 // and returns NULL if the name is already demangled.
96 char* demangled_name
= cplus_demangle(name
, DMGL_ANSI
| DMGL_PARAMS
);
97 if (demangled_name
== NULL
)
100 std::string
retval(demangled_name
);
101 free(demangled_name
);
106 Symbol::demangled_name() const
108 return demangle(this->name());
111 // Initialize the fields in the base class Symbol for SYM in OBJECT.
113 template<int size
, bool big_endian
>
115 Symbol::init_base_object(const char* name
, const char* version
, Object
* object
,
116 const elfcpp::Sym
<size
, big_endian
>& sym
,
117 unsigned int st_shndx
, bool is_ordinary
)
119 this->init_fields(name
, version
, sym
.get_st_type(), sym
.get_st_bind(),
120 sym
.get_st_visibility(), sym
.get_st_nonvis());
121 this->u_
.from_object
.object
= object
;
122 this->u_
.from_object
.shndx
= st_shndx
;
123 this->is_ordinary_shndx_
= is_ordinary
;
124 this->source_
= FROM_OBJECT
;
125 this->in_reg_
= !object
->is_dynamic();
126 this->in_dyn_
= object
->is_dynamic();
127 this->in_real_elf_
= object
->pluginobj() == NULL
;
130 // Initialize the fields in the base class Symbol for a symbol defined
131 // in an Output_data.
134 Symbol::init_base_output_data(const char* name
, const char* version
,
135 Output_data
* od
, elfcpp::STT type
,
136 elfcpp::STB binding
, elfcpp::STV visibility
,
137 unsigned char nonvis
, bool offset_is_from_end
,
140 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
141 this->u_
.in_output_data
.output_data
= od
;
142 this->u_
.in_output_data
.offset_is_from_end
= offset_is_from_end
;
143 this->source_
= IN_OUTPUT_DATA
;
144 this->in_reg_
= true;
145 this->in_real_elf_
= true;
146 this->is_predefined_
= is_predefined
;
149 // Initialize the fields in the base class Symbol for a symbol defined
150 // in an Output_segment.
153 Symbol::init_base_output_segment(const char* name
, const char* version
,
154 Output_segment
* os
, elfcpp::STT type
,
155 elfcpp::STB binding
, elfcpp::STV visibility
,
156 unsigned char nonvis
,
157 Segment_offset_base offset_base
,
160 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
161 this->u_
.in_output_segment
.output_segment
= os
;
162 this->u_
.in_output_segment
.offset_base
= offset_base
;
163 this->source_
= IN_OUTPUT_SEGMENT
;
164 this->in_reg_
= true;
165 this->in_real_elf_
= true;
166 this->is_predefined_
= is_predefined
;
169 // Initialize the fields in the base class Symbol for a symbol defined
173 Symbol::init_base_constant(const char* name
, const char* version
,
174 elfcpp::STT type
, elfcpp::STB binding
,
175 elfcpp::STV visibility
, unsigned char nonvis
,
178 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
179 this->source_
= IS_CONSTANT
;
180 this->in_reg_
= true;
181 this->in_real_elf_
= true;
182 this->is_predefined_
= is_predefined
;
185 // Initialize the fields in the base class Symbol for an undefined
189 Symbol::init_base_undefined(const char* name
, const char* version
,
190 elfcpp::STT type
, elfcpp::STB binding
,
191 elfcpp::STV visibility
, unsigned char nonvis
)
193 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
194 this->dynsym_index_
= -1U;
195 this->source_
= IS_UNDEFINED
;
196 this->in_reg_
= true;
197 this->in_real_elf_
= true;
200 // Allocate a common symbol in the base.
203 Symbol::allocate_base_common(Output_data
* od
)
205 gold_assert(this->is_common());
206 this->source_
= IN_OUTPUT_DATA
;
207 this->u_
.in_output_data
.output_data
= od
;
208 this->u_
.in_output_data
.offset_is_from_end
= false;
211 // Initialize the fields in Sized_symbol for SYM in OBJECT.
214 template<bool big_endian
>
216 Sized_symbol
<size
>::init_object(const char* name
, const char* version
,
218 const elfcpp::Sym
<size
, big_endian
>& sym
,
219 unsigned int st_shndx
, bool is_ordinary
)
221 this->init_base_object(name
, version
, object
, sym
, st_shndx
, is_ordinary
);
222 this->value_
= sym
.get_st_value();
223 this->symsize_
= sym
.get_st_size();
226 // Initialize the fields in Sized_symbol for a symbol defined in an
231 Sized_symbol
<size
>::init_output_data(const char* name
, const char* version
,
232 Output_data
* od
, Value_type value
,
233 Size_type symsize
, elfcpp::STT type
,
235 elfcpp::STV visibility
,
236 unsigned char nonvis
,
237 bool offset_is_from_end
,
240 this->init_base_output_data(name
, version
, od
, type
, binding
, visibility
,
241 nonvis
, offset_is_from_end
, is_predefined
);
242 this->value_
= value
;
243 this->symsize_
= symsize
;
246 // Initialize the fields in Sized_symbol for a symbol defined in an
251 Sized_symbol
<size
>::init_output_segment(const char* name
, const char* version
,
252 Output_segment
* os
, Value_type value
,
253 Size_type symsize
, elfcpp::STT type
,
255 elfcpp::STV visibility
,
256 unsigned char nonvis
,
257 Segment_offset_base offset_base
,
260 this->init_base_output_segment(name
, version
, os
, type
, binding
, visibility
,
261 nonvis
, offset_base
, is_predefined
);
262 this->value_
= value
;
263 this->symsize_
= symsize
;
266 // Initialize the fields in Sized_symbol for a symbol defined as a
271 Sized_symbol
<size
>::init_constant(const char* name
, const char* version
,
272 Value_type value
, Size_type symsize
,
273 elfcpp::STT type
, elfcpp::STB binding
,
274 elfcpp::STV visibility
, unsigned char nonvis
,
277 this->init_base_constant(name
, version
, type
, binding
, visibility
, nonvis
,
279 this->value_
= value
;
280 this->symsize_
= symsize
;
283 // Initialize the fields in Sized_symbol for an undefined symbol.
287 Sized_symbol
<size
>::init_undefined(const char* name
, const char* version
,
288 elfcpp::STT type
, elfcpp::STB binding
,
289 elfcpp::STV visibility
, unsigned char nonvis
)
291 this->init_base_undefined(name
, version
, type
, binding
, visibility
, nonvis
);
296 // Return an allocated string holding the symbol's name as
297 // name@version. This is used for relocatable links.
300 Symbol::versioned_name() const
302 gold_assert(this->version_
!= NULL
);
303 std::string ret
= this->name_
;
307 ret
+= this->version_
;
311 // Return true if SHNDX represents a common symbol.
314 Symbol::is_common_shndx(unsigned int shndx
)
316 return (shndx
== elfcpp::SHN_COMMON
317 || shndx
== parameters
->target().small_common_shndx()
318 || shndx
== parameters
->target().large_common_shndx());
321 // Allocate a common symbol.
325 Sized_symbol
<size
>::allocate_common(Output_data
* od
, Value_type value
)
327 this->allocate_base_common(od
);
328 this->value_
= value
;
331 // The ""'s around str ensure str is a string literal, so sizeof works.
332 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
334 // Return true if this symbol should be added to the dynamic symbol
338 Symbol::should_add_dynsym_entry(Symbol_table
* symtab
) const
340 // If the symbol is only present on plugin files, the plugin decided we
342 if (!this->in_real_elf())
345 // If the symbol is used by a dynamic relocation, we need to add it.
346 if (this->needs_dynsym_entry())
349 // If this symbol's section is not added, the symbol need not be added.
350 // The section may have been GCed. Note that export_dynamic is being
351 // overridden here. This should not be done for shared objects.
352 if (parameters
->options().gc_sections()
353 && !parameters
->options().shared()
354 && this->source() == Symbol::FROM_OBJECT
355 && !this->object()->is_dynamic())
357 Relobj
* relobj
= static_cast<Relobj
*>(this->object());
359 unsigned int shndx
= this->shndx(&is_ordinary
);
360 if (is_ordinary
&& shndx
!= elfcpp::SHN_UNDEF
361 && !relobj
->is_section_included(shndx
)
362 && !symtab
->is_section_folded(relobj
, shndx
))
366 // If the symbol was forced dynamic in a --dynamic-list file
367 // or an --export-dynamic-symbol option, add it.
368 if (!this->is_from_dynobj()
369 && (parameters
->options().in_dynamic_list(this->name())
370 || parameters
->options().is_export_dynamic_symbol(this->name())))
372 if (!this->is_forced_local())
374 gold_warning(_("Cannot export local symbol '%s'"),
375 this->demangled_name().c_str());
379 // If the symbol was forced local in a version script, do not add it.
380 if (this->is_forced_local())
383 // If dynamic-list-data was specified, add any STT_OBJECT.
384 if (parameters
->options().dynamic_list_data()
385 && !this->is_from_dynobj()
386 && this->type() == elfcpp::STT_OBJECT
)
389 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
390 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
391 if ((parameters
->options().dynamic_list_cpp_new()
392 || parameters
->options().dynamic_list_cpp_typeinfo())
393 && !this->is_from_dynobj())
395 // TODO(csilvers): We could probably figure out if we're an operator
396 // new/delete or typeinfo without the need to demangle.
397 char* demangled_name
= cplus_demangle(this->name(),
398 DMGL_ANSI
| DMGL_PARAMS
);
399 if (demangled_name
== NULL
)
401 // Not a C++ symbol, so it can't satisfy these flags
403 else if (parameters
->options().dynamic_list_cpp_new()
404 && (strprefix(demangled_name
, "operator new")
405 || strprefix(demangled_name
, "operator delete")))
407 free(demangled_name
);
410 else if (parameters
->options().dynamic_list_cpp_typeinfo()
411 && (strprefix(demangled_name
, "typeinfo name for")
412 || strprefix(demangled_name
, "typeinfo for")))
414 free(demangled_name
);
418 free(demangled_name
);
421 // If exporting all symbols or building a shared library,
422 // or the symbol should be globally unique (GNU_UNIQUE),
423 // and the symbol is defined in a regular object and is
424 // externally visible, we need to add it.
425 if ((parameters
->options().export_dynamic()
426 || parameters
->options().shared()
427 || (parameters
->options().gnu_unique()
428 && this->binding() == elfcpp::STB_GNU_UNIQUE
))
429 && !this->is_from_dynobj()
430 && !this->is_undefined()
431 && this->is_externally_visible())
437 // Return true if the final value of this symbol is known at link
441 Symbol::final_value_is_known() const
443 // If we are not generating an executable, then no final values are
444 // known, since they will change at runtime, with the exception of
445 // TLS symbols in a position-independent executable.
446 if ((parameters
->options().output_is_position_independent()
447 || parameters
->options().relocatable())
448 && !(this->type() == elfcpp::STT_TLS
449 && parameters
->options().pie()))
452 // If the symbol is not from an object file, and is not undefined,
453 // then it is defined, and known.
454 if (this->source_
!= FROM_OBJECT
)
456 if (this->source_
!= IS_UNDEFINED
)
461 // If the symbol is from a dynamic object, then the final value
463 if (this->object()->is_dynamic())
466 // If the symbol is not undefined (it is defined or common),
467 // then the final value is known.
468 if (!this->is_undefined())
472 // If the symbol is undefined, then whether the final value is known
473 // depends on whether we are doing a static link. If we are doing a
474 // dynamic link, then the final value could be filled in at runtime.
475 // This could reasonably be the case for a weak undefined symbol.
476 return parameters
->doing_static_link();
479 // Return the output section where this symbol is defined.
482 Symbol::output_section() const
484 switch (this->source_
)
488 unsigned int shndx
= this->u_
.from_object
.shndx
;
489 if (shndx
!= elfcpp::SHN_UNDEF
&& this->is_ordinary_shndx_
)
491 gold_assert(!this->u_
.from_object
.object
->is_dynamic());
492 gold_assert(this->u_
.from_object
.object
->pluginobj() == NULL
);
493 Relobj
* relobj
= static_cast<Relobj
*>(this->u_
.from_object
.object
);
494 return relobj
->output_section(shndx
);
500 return this->u_
.in_output_data
.output_data
->output_section();
502 case IN_OUTPUT_SEGMENT
:
512 // Set the symbol's output section. This is used for symbols defined
513 // in scripts. This should only be called after the symbol table has
517 Symbol::set_output_section(Output_section
* os
)
519 switch (this->source_
)
523 gold_assert(this->output_section() == os
);
526 this->source_
= IN_OUTPUT_DATA
;
527 this->u_
.in_output_data
.output_data
= os
;
528 this->u_
.in_output_data
.offset_is_from_end
= false;
530 case IN_OUTPUT_SEGMENT
:
537 // Set the symbol's output segment. This is used for pre-defined
538 // symbols whose segments aren't known until after layout is done
539 // (e.g., __ehdr_start).
542 Symbol::set_output_segment(Output_segment
* os
, Segment_offset_base base
)
544 gold_assert(this->is_predefined_
);
545 this->source_
= IN_OUTPUT_SEGMENT
;
546 this->u_
.in_output_segment
.output_segment
= os
;
547 this->u_
.in_output_segment
.offset_base
= base
;
550 // Set the symbol to undefined. This is used for pre-defined
551 // symbols whose segments aren't known until after layout is done
552 // (e.g., __ehdr_start).
555 Symbol::set_undefined()
557 this->source_
= IS_UNDEFINED
;
558 this->is_predefined_
= false;
561 // Class Symbol_table.
563 Symbol_table::Symbol_table(unsigned int count
,
564 const Version_script_info
& version_script
)
565 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
566 forwarders_(), commons_(), tls_commons_(), small_commons_(),
567 large_commons_(), forced_locals_(), warnings_(),
568 version_script_(version_script
), gc_(NULL
), icf_(NULL
)
570 namepool_
.reserve(count
);
573 Symbol_table::~Symbol_table()
577 // The symbol table key equality function. This is called with
581 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
582 const Symbol_table_key
& k2
) const
584 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
588 Symbol_table::is_section_folded(Relobj
* obj
, unsigned int shndx
) const
590 return (parameters
->options().icf_enabled()
591 && this->icf_
->is_section_folded(obj
, shndx
));
594 // For symbols that have been listed with a -u or --export-dynamic-symbol
595 // option, add them to the work list to avoid gc'ing them.
598 Symbol_table::gc_mark_undef_symbols(Layout
* layout
)
600 for (options::String_set::const_iterator p
=
601 parameters
->options().undefined_begin();
602 p
!= parameters
->options().undefined_end();
605 const char* name
= p
->c_str();
606 Symbol
* sym
= this->lookup(name
);
607 gold_assert(sym
!= NULL
);
608 if (sym
->source() == Symbol::FROM_OBJECT
609 && !sym
->object()->is_dynamic())
611 this->gc_mark_symbol(sym
);
615 for (options::String_set::const_iterator p
=
616 parameters
->options().export_dynamic_symbol_begin();
617 p
!= parameters
->options().export_dynamic_symbol_end();
620 const char* name
= p
->c_str();
621 Symbol
* sym
= this->lookup(name
);
622 // It's not an error if a symbol named by --export-dynamic-symbol
625 && sym
->source() == Symbol::FROM_OBJECT
626 && !sym
->object()->is_dynamic())
628 this->gc_mark_symbol(sym
);
632 for (Script_options::referenced_const_iterator p
=
633 layout
->script_options()->referenced_begin();
634 p
!= layout
->script_options()->referenced_end();
637 Symbol
* sym
= this->lookup(p
->c_str());
638 gold_assert(sym
!= NULL
);
639 if (sym
->source() == Symbol::FROM_OBJECT
640 && !sym
->object()->is_dynamic())
642 this->gc_mark_symbol(sym
);
648 Symbol_table::gc_mark_symbol(Symbol
* sym
)
650 // Add the object and section to the work list.
652 unsigned int shndx
= sym
->shndx(&is_ordinary
);
653 if (is_ordinary
&& shndx
!= elfcpp::SHN_UNDEF
&& !sym
->object()->is_dynamic())
655 gold_assert(this->gc_
!= NULL
);
656 Relobj
* relobj
= static_cast<Relobj
*>(sym
->object());
657 this->gc_
->worklist().push_back(Section_id(relobj
, shndx
));
659 parameters
->target().gc_mark_symbol(this, sym
);
662 // When doing garbage collection, keep symbols that have been seen in
665 Symbol_table::gc_mark_dyn_syms(Symbol
* sym
)
667 if (sym
->in_dyn() && sym
->source() == Symbol::FROM_OBJECT
668 && !sym
->object()->is_dynamic())
669 this->gc_mark_symbol(sym
);
672 // Make TO a symbol which forwards to FROM.
675 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
677 gold_assert(from
!= to
);
678 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
679 this->forwarders_
[from
] = to
;
680 from
->set_forwarder();
683 // Resolve the forwards from FROM, returning the real symbol.
686 Symbol_table::resolve_forwards(const Symbol
* from
) const
688 gold_assert(from
->is_forwarder());
689 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
690 this->forwarders_
.find(from
);
691 gold_assert(p
!= this->forwarders_
.end());
695 // Look up a symbol by name.
698 Symbol_table::lookup(const char* name
, const char* version
) const
700 Stringpool::Key name_key
;
701 name
= this->namepool_
.find(name
, &name_key
);
705 Stringpool::Key version_key
= 0;
708 version
= this->namepool_
.find(version
, &version_key
);
713 Symbol_table_key
key(name_key
, version_key
);
714 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
715 if (p
== this->table_
.end())
720 // Resolve a Symbol with another Symbol. This is only used in the
721 // unusual case where there are references to both an unversioned
722 // symbol and a symbol with a version, and we then discover that that
723 // version is the default version. Because this is unusual, we do
724 // this the slow way, by converting back to an ELF symbol.
726 template<int size
, bool big_endian
>
728 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
)
730 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
731 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
732 // We don't bother to set the st_name or the st_shndx field.
733 esym
.put_st_value(from
->value());
734 esym
.put_st_size(from
->symsize());
735 esym
.put_st_info(from
->binding(), from
->type());
736 esym
.put_st_other(from
->visibility(), from
->nonvis());
738 unsigned int shndx
= from
->shndx(&is_ordinary
);
739 this->resolve(to
, esym
.sym(), shndx
, is_ordinary
, shndx
, from
->object(),
740 from
->version(), true);
745 if (parameters
->options().gc_sections())
746 this->gc_mark_dyn_syms(to
);
749 // Record that a symbol is forced to be local by a version script or
753 Symbol_table::force_local(Symbol
* sym
)
755 if (!sym
->is_defined() && !sym
->is_common())
757 if (sym
->is_forced_local())
759 // We already got this one.
762 sym
->set_is_forced_local();
763 this->forced_locals_
.push_back(sym
);
766 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
767 // is only called for undefined symbols, when at least one --wrap
771 Symbol_table::wrap_symbol(const char* name
, Stringpool::Key
* name_key
)
773 // For some targets, we need to ignore a specific character when
774 // wrapping, and add it back later.
776 if (name
[0] == parameters
->target().wrap_char())
782 if (parameters
->options().is_wrap(name
))
784 // Turn NAME into __wrap_NAME.
791 // This will give us both the old and new name in NAMEPOOL_, but
792 // that is OK. Only the versions we need will wind up in the
793 // real string table in the output file.
794 return this->namepool_
.add(s
.c_str(), true, name_key
);
797 const char* const real_prefix
= "__real_";
798 const size_t real_prefix_length
= strlen(real_prefix
);
799 if (strncmp(name
, real_prefix
, real_prefix_length
) == 0
800 && parameters
->options().is_wrap(name
+ real_prefix_length
))
802 // Turn __real_NAME into NAME.
806 s
+= name
+ real_prefix_length
;
807 return this->namepool_
.add(s
.c_str(), true, name_key
);
813 // This is called when we see a symbol NAME/VERSION, and the symbol
814 // already exists in the symbol table, and VERSION is marked as being
815 // the default version. SYM is the NAME/VERSION symbol we just added.
816 // DEFAULT_IS_NEW is true if this is the first time we have seen the
817 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
819 template<int size
, bool big_endian
>
821 Symbol_table::define_default_version(Sized_symbol
<size
>* sym
,
823 Symbol_table_type::iterator pdef
)
827 // This is the first time we have seen NAME/NULL. Make
828 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
831 sym
->set_is_default();
833 else if (pdef
->second
== sym
)
835 // NAME/NULL already points to NAME/VERSION. Don't mark the
836 // symbol as the default if it is not already the default.
840 // This is the unfortunate case where we already have entries
841 // for both NAME/VERSION and NAME/NULL. We now see a symbol
842 // NAME/VERSION where VERSION is the default version. We have
843 // already resolved this new symbol with the existing
844 // NAME/VERSION symbol.
846 // It's possible that NAME/NULL and NAME/VERSION are both
847 // defined in regular objects. This can only happen if one
848 // object file defines foo and another defines foo@@ver. This
849 // is somewhat obscure, but we call it a multiple definition
852 // It's possible that NAME/NULL actually has a version, in which
853 // case it won't be the same as VERSION. This happens with
854 // ver_test_7.so in the testsuite for the symbol t2_2. We see
855 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
856 // then see an unadorned t2_2 in an object file and give it
857 // version VER1 from the version script. This looks like a
858 // default definition for VER1, so it looks like we should merge
859 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
860 // not obvious that this is an error, either. So we just punt.
862 // If one of the symbols has non-default visibility, and the
863 // other is defined in a shared object, then they are different
866 // Otherwise, we just resolve the symbols as though they were
869 if (pdef
->second
->version() != NULL
)
870 gold_assert(pdef
->second
->version() != sym
->version());
871 else if (sym
->visibility() != elfcpp::STV_DEFAULT
872 && pdef
->second
->is_from_dynobj())
874 else if (pdef
->second
->visibility() != elfcpp::STV_DEFAULT
875 && sym
->is_from_dynobj())
879 const Sized_symbol
<size
>* symdef
;
880 symdef
= this->get_sized_symbol
<size
>(pdef
->second
);
881 Symbol_table::resolve
<size
, big_endian
>(sym
, symdef
);
882 this->make_forwarder(pdef
->second
, sym
);
884 sym
->set_is_default();
889 // Add one symbol from OBJECT to the symbol table. NAME is symbol
890 // name and VERSION is the version; both are canonicalized. DEF is
891 // whether this is the default version. ST_SHNDX is the symbol's
892 // section index; IS_ORDINARY is whether this is a normal section
893 // rather than a special code.
895 // If IS_DEFAULT_VERSION is true, then this is the definition of a
896 // default version of a symbol. That means that any lookup of
897 // NAME/NULL and any lookup of NAME/VERSION should always return the
898 // same symbol. This is obvious for references, but in particular we
899 // want to do this for definitions: overriding NAME/NULL should also
900 // override NAME/VERSION. If we don't do that, it would be very hard
901 // to override functions in a shared library which uses versioning.
903 // We implement this by simply making both entries in the hash table
904 // point to the same Symbol structure. That is easy enough if this is
905 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
906 // that we have seen both already, in which case they will both have
907 // independent entries in the symbol table. We can't simply change
908 // the symbol table entry, because we have pointers to the entries
909 // attached to the object files. So we mark the entry attached to the
910 // object file as a forwarder, and record it in the forwarders_ map.
911 // Note that entries in the hash table will never be marked as
914 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
915 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
916 // for a special section code. ST_SHNDX may be modified if the symbol
917 // is defined in a section being discarded.
919 template<int size
, bool big_endian
>
921 Symbol_table::add_from_object(Object
* object
,
923 Stringpool::Key name_key
,
925 Stringpool::Key version_key
,
926 bool is_default_version
,
927 const elfcpp::Sym
<size
, big_endian
>& sym
,
928 unsigned int st_shndx
,
930 unsigned int orig_st_shndx
)
932 // Print a message if this symbol is being traced.
933 if (parameters
->options().is_trace_symbol(name
))
935 if (orig_st_shndx
== elfcpp::SHN_UNDEF
)
936 gold_info(_("%s: reference to %s"), object
->name().c_str(), name
);
938 gold_info(_("%s: definition of %s"), object
->name().c_str(), name
);
941 // For an undefined symbol, we may need to adjust the name using
943 if (orig_st_shndx
== elfcpp::SHN_UNDEF
944 && parameters
->options().any_wrap())
946 const char* wrap_name
= this->wrap_symbol(name
, &name_key
);
947 if (wrap_name
!= name
)
949 // If we see a reference to malloc with version GLIBC_2.0,
950 // and we turn it into a reference to __wrap_malloc, then we
951 // discard the version number. Otherwise the user would be
952 // required to specify the correct version for
960 Symbol
* const snull
= NULL
;
961 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
962 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
965 std::pair
<typename
Symbol_table_type::iterator
, bool> insdefault
=
966 std::make_pair(this->table_
.end(), false);
967 if (is_default_version
)
969 const Stringpool::Key vnull_key
= 0;
970 insdefault
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
975 // ins.first: an iterator, which is a pointer to a pair.
976 // ins.first->first: the key (a pair of name and version).
977 // ins.first->second: the value (Symbol*).
978 // ins.second: true if new entry was inserted, false if not.
980 Sized_symbol
<size
>* ret
;
985 // We already have an entry for NAME/VERSION.
986 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
987 gold_assert(ret
!= NULL
);
989 was_undefined
= ret
->is_undefined();
990 // Commons from plugins are just placeholders.
991 was_common
= ret
->is_common() && ret
->object()->pluginobj() == NULL
;
993 this->resolve(ret
, sym
, st_shndx
, is_ordinary
, orig_st_shndx
, object
,
994 version
, is_default_version
);
995 if (parameters
->options().gc_sections())
996 this->gc_mark_dyn_syms(ret
);
998 if (is_default_version
)
999 this->define_default_version
<size
, big_endian
>(ret
, insdefault
.second
,
1005 && ret
->source() == Symbol::FROM_OBJECT
1006 && ret
->object() == object
1008 && ret
->shndx(&dummy
) == st_shndx
1009 && ret
->is_default())
1011 // We have seen NAME/VERSION already, and marked it as the
1012 // default version, but now we see a definition for
1013 // NAME/VERSION that is not the default version. This can
1014 // happen when the assembler generates two symbols for
1015 // a symbol as a result of a ".symver foo,foo@VER"
1016 // directive. We see the first unversioned symbol and
1017 // we may mark it as the default version (from a
1018 // version script); then we see the second versioned
1019 // symbol and we need to override the first.
1020 // In any other case, the two symbols should have generated
1021 // a multiple definition error.
1022 // (See PR gold/18703.)
1023 ret
->set_is_not_default();
1024 const Stringpool::Key vnull_key
= 0;
1025 this->table_
.erase(std::make_pair(name_key
, vnull_key
));
1031 // This is the first time we have seen NAME/VERSION.
1032 gold_assert(ins
.first
->second
== NULL
);
1034 if (is_default_version
&& !insdefault
.second
)
1036 // We already have an entry for NAME/NULL. If we override
1037 // it, then change it to NAME/VERSION.
1038 ret
= this->get_sized_symbol
<size
>(insdefault
.first
->second
);
1040 was_undefined
= ret
->is_undefined();
1041 // Commons from plugins are just placeholders.
1042 was_common
= ret
->is_common() && ret
->object()->pluginobj() == NULL
;
1044 this->resolve(ret
, sym
, st_shndx
, is_ordinary
, orig_st_shndx
, object
,
1045 version
, is_default_version
);
1046 if (parameters
->options().gc_sections())
1047 this->gc_mark_dyn_syms(ret
);
1048 ins
.first
->second
= ret
;
1052 was_undefined
= false;
1055 Sized_target
<size
, big_endian
>* target
=
1056 parameters
->sized_target
<size
, big_endian
>();
1057 if (!target
->has_make_symbol())
1058 ret
= new Sized_symbol
<size
>();
1061 ret
= target
->make_symbol();
1064 // This means that we don't want a symbol table
1066 if (!is_default_version
)
1067 this->table_
.erase(ins
.first
);
1070 this->table_
.erase(insdefault
.first
);
1071 // Inserting INSDEFAULT invalidated INS.
1072 this->table_
.erase(std::make_pair(name_key
,
1079 ret
->init_object(name
, version
, object
, sym
, st_shndx
, is_ordinary
);
1081 ins
.first
->second
= ret
;
1082 if (is_default_version
)
1084 // This is the first time we have seen NAME/NULL. Point
1085 // it at the new entry for NAME/VERSION.
1086 gold_assert(insdefault
.second
);
1087 insdefault
.first
->second
= ret
;
1091 if (is_default_version
)
1092 ret
->set_is_default();
1095 // Record every time we see a new undefined symbol, to speed up
1097 if (!was_undefined
&& ret
->is_undefined())
1099 ++this->saw_undefined_
;
1100 if (parameters
->options().has_plugins())
1101 parameters
->options().plugins()->new_undefined_symbol(ret
);
1104 // Keep track of common symbols, to speed up common symbol
1105 // allocation. Don't record commons from plugin objects;
1106 // we need to wait until we see the real symbol in the
1107 // replacement file.
1108 if (!was_common
&& ret
->is_common() && ret
->object()->pluginobj() == NULL
)
1110 if (ret
->type() == elfcpp::STT_TLS
)
1111 this->tls_commons_
.push_back(ret
);
1112 else if (!is_ordinary
1113 && st_shndx
== parameters
->target().small_common_shndx())
1114 this->small_commons_
.push_back(ret
);
1115 else if (!is_ordinary
1116 && st_shndx
== parameters
->target().large_common_shndx())
1117 this->large_commons_
.push_back(ret
);
1119 this->commons_
.push_back(ret
);
1122 // If we're not doing a relocatable link, then any symbol with
1123 // hidden or internal visibility is local.
1124 if ((ret
->visibility() == elfcpp::STV_HIDDEN
1125 || ret
->visibility() == elfcpp::STV_INTERNAL
)
1126 && (ret
->binding() == elfcpp::STB_GLOBAL
1127 || ret
->binding() == elfcpp::STB_GNU_UNIQUE
1128 || ret
->binding() == elfcpp::STB_WEAK
)
1129 && !parameters
->options().relocatable())
1130 this->force_local(ret
);
1135 // Add all the symbols in a relocatable object to the hash table.
1137 template<int size
, bool big_endian
>
1139 Symbol_table::add_from_relobj(
1140 Sized_relobj_file
<size
, big_endian
>* relobj
,
1141 const unsigned char* syms
,
1143 size_t symndx_offset
,
1144 const char* sym_names
,
1145 size_t sym_name_size
,
1146 typename Sized_relobj_file
<size
, big_endian
>::Symbols
* sympointers
,
1151 gold_assert(size
== parameters
->target().get_size());
1153 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1155 const bool just_symbols
= relobj
->just_symbols();
1157 const unsigned char* p
= syms
;
1158 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
1160 (*sympointers
)[i
] = NULL
;
1162 elfcpp::Sym
<size
, big_endian
> sym(p
);
1164 unsigned int st_name
= sym
.get_st_name();
1165 if (st_name
>= sym_name_size
)
1167 relobj
->error(_("bad global symbol name offset %u at %zu"),
1172 const char* name
= sym_names
+ st_name
;
1174 if (strcmp (name
, "__gnu_lto_slim") == 0)
1175 gold_info(_("%s: plugin needed to handle lto object"),
1176 relobj
->name().c_str());
1179 unsigned int st_shndx
= relobj
->adjust_sym_shndx(i
+ symndx_offset
,
1182 unsigned int orig_st_shndx
= st_shndx
;
1184 orig_st_shndx
= elfcpp::SHN_UNDEF
;
1186 if (st_shndx
!= elfcpp::SHN_UNDEF
)
1189 // A symbol defined in a section which we are not including must
1190 // be treated as an undefined symbol.
1191 bool is_defined_in_discarded_section
= false;
1192 if (st_shndx
!= elfcpp::SHN_UNDEF
1194 && !relobj
->is_section_included(st_shndx
)
1195 && !this->is_section_folded(relobj
, st_shndx
))
1197 st_shndx
= elfcpp::SHN_UNDEF
;
1198 is_defined_in_discarded_section
= true;
1201 // In an object file, an '@' in the name separates the symbol
1202 // name from the version name. If there are two '@' characters,
1203 // this is the default version.
1204 const char* ver
= strchr(name
, '@');
1205 Stringpool::Key ver_key
= 0;
1207 // IS_DEFAULT_VERSION: is the version default?
1208 // IS_FORCED_LOCAL: is the symbol forced local?
1209 bool is_default_version
= false;
1210 bool is_forced_local
= false;
1212 // FIXME: For incremental links, we don't store version information,
1213 // so we need to ignore version symbols for now.
1214 if (parameters
->incremental_update() && ver
!= NULL
)
1216 namelen
= ver
- name
;
1222 // The symbol name is of the form foo@VERSION or foo@@VERSION
1223 namelen
= ver
- name
;
1227 is_default_version
= true;
1230 ver
= this->namepool_
.add(ver
, true, &ver_key
);
1232 // We don't want to assign a version to an undefined symbol,
1233 // even if it is listed in the version script. FIXME: What
1234 // about a common symbol?
1237 namelen
= strlen(name
);
1238 if (!this->version_script_
.empty()
1239 && st_shndx
!= elfcpp::SHN_UNDEF
)
1241 // The symbol name did not have a version, but the
1242 // version script may assign a version anyway.
1243 std::string version
;
1245 if (this->version_script_
.get_symbol_version(name
, &version
,
1249 is_forced_local
= true;
1250 else if (!version
.empty())
1252 ver
= this->namepool_
.add_with_length(version
.c_str(),
1256 is_default_version
= true;
1262 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
1263 unsigned char symbuf
[sym_size
];
1264 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
1267 memcpy(symbuf
, p
, sym_size
);
1268 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1269 if (orig_st_shndx
!= elfcpp::SHN_UNDEF
1271 && relobj
->e_type() == elfcpp::ET_REL
)
1273 // Symbol values in relocatable object files are section
1274 // relative. This is normally what we want, but since here
1275 // we are converting the symbol to absolute we need to add
1276 // the section address. The section address in an object
1277 // file is normally zero, but people can use a linker
1278 // script to change it.
1279 sw
.put_st_value(sym
.get_st_value()
1280 + relobj
->section_address(orig_st_shndx
));
1282 st_shndx
= elfcpp::SHN_ABS
;
1283 is_ordinary
= false;
1287 // Fix up visibility if object has no-export set.
1288 if (relobj
->no_export()
1289 && (orig_st_shndx
!= elfcpp::SHN_UNDEF
|| !is_ordinary
))
1291 // We may have copied symbol already above.
1294 memcpy(symbuf
, p
, sym_size
);
1298 elfcpp::STV visibility
= sym2
.get_st_visibility();
1299 if (visibility
== elfcpp::STV_DEFAULT
1300 || visibility
== elfcpp::STV_PROTECTED
)
1302 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1303 unsigned char nonvis
= sym2
.get_st_nonvis();
1304 sw
.put_st_other(elfcpp::STV_HIDDEN
, nonvis
);
1308 Stringpool::Key name_key
;
1309 name
= this->namepool_
.add_with_length(name
, namelen
, true,
1312 Sized_symbol
<size
>* res
;
1313 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
1314 is_default_version
, *psym
, st_shndx
,
1315 is_ordinary
, orig_st_shndx
);
1317 if (is_forced_local
)
1318 this->force_local(res
);
1320 // Do not treat this symbol as garbage if this symbol will be
1321 // exported to the dynamic symbol table. This is true when
1322 // building a shared library or using --export-dynamic and
1323 // the symbol is externally visible.
1324 if (parameters
->options().gc_sections()
1325 && res
->is_externally_visible()
1326 && !res
->is_from_dynobj()
1327 && (parameters
->options().shared()
1328 || parameters
->options().export_dynamic()
1329 || parameters
->options().in_dynamic_list(res
->name())))
1330 this->gc_mark_symbol(res
);
1332 if (is_defined_in_discarded_section
)
1333 res
->set_is_defined_in_discarded_section();
1335 (*sympointers
)[i
] = res
;
1339 // Add a symbol from a plugin-claimed file.
1341 template<int size
, bool big_endian
>
1343 Symbol_table::add_from_pluginobj(
1344 Sized_pluginobj
<size
, big_endian
>* obj
,
1347 elfcpp::Sym
<size
, big_endian
>* sym
)
1349 unsigned int st_shndx
= sym
->get_st_shndx();
1350 bool is_ordinary
= st_shndx
< elfcpp::SHN_LORESERVE
;
1352 Stringpool::Key ver_key
= 0;
1353 bool is_default_version
= false;
1354 bool is_forced_local
= false;
1358 ver
= this->namepool_
.add(ver
, true, &ver_key
);
1360 // We don't want to assign a version to an undefined symbol,
1361 // even if it is listed in the version script. FIXME: What
1362 // about a common symbol?
1365 if (!this->version_script_
.empty()
1366 && st_shndx
!= elfcpp::SHN_UNDEF
)
1368 // The symbol name did not have a version, but the
1369 // version script may assign a version anyway.
1370 std::string version
;
1372 if (this->version_script_
.get_symbol_version(name
, &version
,
1376 is_forced_local
= true;
1377 else if (!version
.empty())
1379 ver
= this->namepool_
.add_with_length(version
.c_str(),
1383 is_default_version
= true;
1389 Stringpool::Key name_key
;
1390 name
= this->namepool_
.add(name
, true, &name_key
);
1392 Sized_symbol
<size
>* res
;
1393 res
= this->add_from_object(obj
, name
, name_key
, ver
, ver_key
,
1394 is_default_version
, *sym
, st_shndx
,
1395 is_ordinary
, st_shndx
);
1397 if (is_forced_local
)
1398 this->force_local(res
);
1403 // Add all the symbols in a dynamic object to the hash table.
1405 template<int size
, bool big_endian
>
1407 Symbol_table::add_from_dynobj(
1408 Sized_dynobj
<size
, big_endian
>* dynobj
,
1409 const unsigned char* syms
,
1411 const char* sym_names
,
1412 size_t sym_name_size
,
1413 const unsigned char* versym
,
1415 const std::vector
<const char*>* version_map
,
1416 typename Sized_relobj_file
<size
, big_endian
>::Symbols
* sympointers
,
1421 gold_assert(size
== parameters
->target().get_size());
1423 if (dynobj
->just_symbols())
1425 gold_error(_("--just-symbols does not make sense with a shared object"));
1429 // FIXME: For incremental links, we don't store version information,
1430 // so we need to ignore version symbols for now.
1431 if (parameters
->incremental_update())
1434 if (versym
!= NULL
&& versym_size
/ 2 < count
)
1436 dynobj
->error(_("too few symbol versions"));
1440 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1442 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1443 // weak aliases. This is necessary because if the dynamic object
1444 // provides the same variable under two names, one of which is a
1445 // weak definition, and the regular object refers to the weak
1446 // definition, we have to put both the weak definition and the
1447 // strong definition into the dynamic symbol table. Given a weak
1448 // definition, the only way that we can find the corresponding
1449 // strong definition, if any, is to search the symbol table.
1450 std::vector
<Sized_symbol
<size
>*> object_symbols
;
1452 const unsigned char* p
= syms
;
1453 const unsigned char* vs
= versym
;
1454 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
1456 elfcpp::Sym
<size
, big_endian
> sym(p
);
1458 if (sympointers
!= NULL
)
1459 (*sympointers
)[i
] = NULL
;
1461 // Ignore symbols with local binding or that have
1462 // internal or hidden visibility.
1463 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
1464 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
1465 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
1468 // A protected symbol in a shared library must be treated as a
1469 // normal symbol when viewed from outside the shared library.
1470 // Implement this by overriding the visibility here.
1471 // Likewise, an IFUNC symbol in a shared library must be treated
1472 // as a normal FUNC symbol.
1473 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
1474 unsigned char symbuf
[sym_size
];
1475 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
1476 if (sym
.get_st_visibility() == elfcpp::STV_PROTECTED
1477 || sym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1479 memcpy(symbuf
, p
, sym_size
);
1480 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1481 if (sym
.get_st_visibility() == elfcpp::STV_PROTECTED
)
1482 sw
.put_st_other(elfcpp::STV_DEFAULT
, sym
.get_st_nonvis());
1483 if (sym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1484 sw
.put_st_info(sym
.get_st_bind(), elfcpp::STT_FUNC
);
1488 unsigned int st_name
= psym
->get_st_name();
1489 if (st_name
>= sym_name_size
)
1491 dynobj
->error(_("bad symbol name offset %u at %zu"),
1496 const char* name
= sym_names
+ st_name
;
1499 unsigned int st_shndx
= dynobj
->adjust_sym_shndx(i
, psym
->get_st_shndx(),
1502 if (st_shndx
!= elfcpp::SHN_UNDEF
)
1505 Sized_symbol
<size
>* res
;
1509 Stringpool::Key name_key
;
1510 name
= this->namepool_
.add(name
, true, &name_key
);
1511 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1512 false, *psym
, st_shndx
, is_ordinary
,
1517 // Read the version information.
1519 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
1521 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
1522 v
&= elfcpp::VERSYM_VERSION
;
1524 // The Sun documentation says that V can be VER_NDX_LOCAL,
1525 // or VER_NDX_GLOBAL, or a version index. The meaning of
1526 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1527 // The old GNU linker will happily generate VER_NDX_LOCAL
1528 // for an undefined symbol. I don't know what the Sun
1529 // linker will generate.
1531 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
1532 && st_shndx
!= elfcpp::SHN_UNDEF
)
1534 // This symbol should not be visible outside the object.
1538 // At this point we are definitely going to add this symbol.
1539 Stringpool::Key name_key
;
1540 name
= this->namepool_
.add(name
, true, &name_key
);
1542 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
1543 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
1545 // This symbol does not have a version.
1546 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1547 false, *psym
, st_shndx
, is_ordinary
,
1552 if (v
>= version_map
->size())
1554 dynobj
->error(_("versym for symbol %zu out of range: %u"),
1559 const char* version
= (*version_map
)[v
];
1560 if (version
== NULL
)
1562 dynobj
->error(_("versym for symbol %zu has no name: %u"),
1567 Stringpool::Key version_key
;
1568 version
= this->namepool_
.add(version
, true, &version_key
);
1570 // If this is an absolute symbol, and the version name
1571 // and symbol name are the same, then this is the
1572 // version definition symbol. These symbols exist to
1573 // support using -u to pull in particular versions. We
1574 // do not want to record a version for them.
1575 if (st_shndx
== elfcpp::SHN_ABS
1577 && name_key
== version_key
)
1578 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1579 false, *psym
, st_shndx
, is_ordinary
,
1583 const bool is_default_version
=
1584 !hidden
&& st_shndx
!= elfcpp::SHN_UNDEF
;
1585 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
1586 version_key
, is_default_version
,
1588 is_ordinary
, st_shndx
);
1593 // Note that it is possible that RES was overridden by an
1594 // earlier object, in which case it can't be aliased here.
1595 if (st_shndx
!= elfcpp::SHN_UNDEF
1597 && psym
->get_st_type() == elfcpp::STT_OBJECT
1598 && res
->source() == Symbol::FROM_OBJECT
1599 && res
->object() == dynobj
)
1600 object_symbols
.push_back(res
);
1602 if (sympointers
!= NULL
)
1603 (*sympointers
)[i
] = res
;
1606 this->record_weak_aliases(&object_symbols
);
1609 // Add a symbol from a incremental object file.
1611 template<int size
, bool big_endian
>
1613 Symbol_table::add_from_incrobj(
1617 elfcpp::Sym
<size
, big_endian
>* sym
)
1619 unsigned int st_shndx
= sym
->get_st_shndx();
1620 bool is_ordinary
= st_shndx
< elfcpp::SHN_LORESERVE
;
1622 Stringpool::Key ver_key
= 0;
1623 bool is_default_version
= false;
1624 bool is_forced_local
= false;
1626 Stringpool::Key name_key
;
1627 name
= this->namepool_
.add(name
, true, &name_key
);
1629 Sized_symbol
<size
>* res
;
1630 res
= this->add_from_object(obj
, name
, name_key
, ver
, ver_key
,
1631 is_default_version
, *sym
, st_shndx
,
1632 is_ordinary
, st_shndx
);
1634 if (is_forced_local
)
1635 this->force_local(res
);
1640 // This is used to sort weak aliases. We sort them first by section
1641 // index, then by offset, then by weak ahead of strong.
1644 class Weak_alias_sorter
1647 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
1652 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
1653 const Sized_symbol
<size
>* s2
) const
1656 unsigned int s1_shndx
= s1
->shndx(&is_ordinary
);
1657 gold_assert(is_ordinary
);
1658 unsigned int s2_shndx
= s2
->shndx(&is_ordinary
);
1659 gold_assert(is_ordinary
);
1660 if (s1_shndx
!= s2_shndx
)
1661 return s1_shndx
< s2_shndx
;
1663 if (s1
->value() != s2
->value())
1664 return s1
->value() < s2
->value();
1665 if (s1
->binding() != s2
->binding())
1667 if (s1
->binding() == elfcpp::STB_WEAK
)
1669 if (s2
->binding() == elfcpp::STB_WEAK
)
1672 return std::string(s1
->name()) < std::string(s2
->name());
1675 // SYMBOLS is a list of object symbols from a dynamic object. Look
1676 // for any weak aliases, and record them so that if we add the weak
1677 // alias to the dynamic symbol table, we also add the corresponding
1682 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
1684 // Sort the vector by section index, then by offset, then by weak
1686 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
1688 // Walk through the vector. For each weak definition, record
1690 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
1692 p
!= symbols
->end();
1695 if ((*p
)->binding() != elfcpp::STB_WEAK
)
1698 // Build a circular list of weak aliases. Each symbol points to
1699 // the next one in the circular list.
1701 Sized_symbol
<size
>* from_sym
= *p
;
1702 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
1703 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
1706 if ((*q
)->shndx(&dummy
) != from_sym
->shndx(&dummy
)
1707 || (*q
)->value() != from_sym
->value())
1710 this->weak_aliases_
[from_sym
] = *q
;
1711 from_sym
->set_has_alias();
1717 this->weak_aliases_
[from_sym
] = *p
;
1718 from_sym
->set_has_alias();
1725 // Create and return a specially defined symbol. If ONLY_IF_REF is
1726 // true, then only create the symbol if there is a reference to it.
1727 // If this does not return NULL, it sets *POLDSYM to the existing
1728 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1729 // resolve the newly created symbol to the old one. This
1730 // canonicalizes *PNAME and *PVERSION.
1732 template<int size
, bool big_endian
>
1734 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1736 Sized_symbol
<size
>** poldsym
,
1737 bool* resolve_oldsym
)
1739 *resolve_oldsym
= false;
1742 // If the caller didn't give us a version, see if we get one from
1743 // the version script.
1745 bool is_default_version
= false;
1746 if (*pversion
== NULL
)
1749 if (this->version_script_
.get_symbol_version(*pname
, &v
, &is_global
))
1751 if (is_global
&& !v
.empty())
1753 *pversion
= v
.c_str();
1754 // If we get the version from a version script, then we
1755 // are also the default version.
1756 is_default_version
= true;
1762 Sized_symbol
<size
>* sym
;
1764 bool add_to_table
= false;
1765 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1766 bool add_def_to_table
= false;
1767 typename
Symbol_table_type::iterator add_def_loc
= this->table_
.end();
1771 oldsym
= this->lookup(*pname
, *pversion
);
1772 if (oldsym
== NULL
&& is_default_version
)
1773 oldsym
= this->lookup(*pname
, NULL
);
1774 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1777 *pname
= oldsym
->name();
1778 if (is_default_version
)
1779 *pversion
= this->namepool_
.add(*pversion
, true, NULL
);
1781 *pversion
= oldsym
->version();
1785 // Canonicalize NAME and VERSION.
1786 Stringpool::Key name_key
;
1787 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1789 Stringpool::Key version_key
= 0;
1790 if (*pversion
!= NULL
)
1791 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1793 Symbol
* const snull
= NULL
;
1794 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1795 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1799 std::pair
<typename
Symbol_table_type::iterator
, bool> insdefault
=
1800 std::make_pair(this->table_
.end(), false);
1801 if (is_default_version
)
1803 const Stringpool::Key vnull
= 0;
1805 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1812 // We already have a symbol table entry for NAME/VERSION.
1813 oldsym
= ins
.first
->second
;
1814 gold_assert(oldsym
!= NULL
);
1816 if (is_default_version
)
1818 Sized_symbol
<size
>* soldsym
=
1819 this->get_sized_symbol
<size
>(oldsym
);
1820 this->define_default_version
<size
, big_endian
>(soldsym
,
1827 // We haven't seen this symbol before.
1828 gold_assert(ins
.first
->second
== NULL
);
1830 add_to_table
= true;
1831 add_loc
= ins
.first
;
1833 if (is_default_version
&& !insdefault
.second
)
1835 // We are adding NAME/VERSION, and it is the default
1836 // version. We already have an entry for NAME/NULL.
1837 oldsym
= insdefault
.first
->second
;
1838 *resolve_oldsym
= true;
1844 if (is_default_version
)
1846 add_def_to_table
= true;
1847 add_def_loc
= insdefault
.first
;
1853 const Target
& target
= parameters
->target();
1854 if (!target
.has_make_symbol())
1855 sym
= new Sized_symbol
<size
>();
1858 Sized_target
<size
, big_endian
>* sized_target
=
1859 parameters
->sized_target
<size
, big_endian
>();
1860 sym
= sized_target
->make_symbol();
1866 add_loc
->second
= sym
;
1868 gold_assert(oldsym
!= NULL
);
1870 if (add_def_to_table
)
1871 add_def_loc
->second
= sym
;
1873 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1878 // Define a symbol based on an Output_data.
1881 Symbol_table::define_in_output_data(const char* name
,
1882 const char* version
,
1888 elfcpp::STB binding
,
1889 elfcpp::STV visibility
,
1890 unsigned char nonvis
,
1891 bool offset_is_from_end
,
1894 if (parameters
->target().get_size() == 32)
1896 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1897 return this->do_define_in_output_data
<32>(name
, version
, defined
, od
,
1898 value
, symsize
, type
, binding
,
1906 else if (parameters
->target().get_size() == 64)
1908 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1909 return this->do_define_in_output_data
<64>(name
, version
, defined
, od
,
1910 value
, symsize
, type
, binding
,
1922 // Define a symbol in an Output_data, sized version.
1926 Symbol_table::do_define_in_output_data(
1928 const char* version
,
1931 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1932 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1934 elfcpp::STB binding
,
1935 elfcpp::STV visibility
,
1936 unsigned char nonvis
,
1937 bool offset_is_from_end
,
1940 Sized_symbol
<size
>* sym
;
1941 Sized_symbol
<size
>* oldsym
;
1942 bool resolve_oldsym
;
1944 if (parameters
->target().is_big_endian())
1946 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1947 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1948 only_if_ref
, &oldsym
,
1956 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1957 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1958 only_if_ref
, &oldsym
,
1968 sym
->init_output_data(name
, version
, od
, value
, symsize
, type
, binding
,
1969 visibility
, nonvis
, offset_is_from_end
,
1970 defined
== PREDEFINED
);
1974 if (binding
== elfcpp::STB_LOCAL
1975 || this->version_script_
.symbol_is_local(name
))
1976 this->force_local(sym
);
1977 else if (version
!= NULL
)
1978 sym
->set_is_default();
1982 if (Symbol_table::should_override_with_special(oldsym
, type
, defined
))
1983 this->override_with_special(oldsym
, sym
);
1989 if (binding
== elfcpp::STB_LOCAL
1990 || this->version_script_
.symbol_is_local(name
))
1991 this->force_local(oldsym
);
1997 // Define a symbol based on an Output_segment.
2000 Symbol_table::define_in_output_segment(const char* name
,
2001 const char* version
,
2007 elfcpp::STB binding
,
2008 elfcpp::STV visibility
,
2009 unsigned char nonvis
,
2010 Symbol::Segment_offset_base offset_base
,
2013 if (parameters
->target().get_size() == 32)
2015 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2016 return this->do_define_in_output_segment
<32>(name
, version
, defined
, os
,
2017 value
, symsize
, type
,
2018 binding
, visibility
, nonvis
,
2019 offset_base
, only_if_ref
);
2024 else if (parameters
->target().get_size() == 64)
2026 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2027 return this->do_define_in_output_segment
<64>(name
, version
, defined
, os
,
2028 value
, symsize
, type
,
2029 binding
, visibility
, nonvis
,
2030 offset_base
, only_if_ref
);
2039 // Define a symbol in an Output_segment, sized version.
2043 Symbol_table::do_define_in_output_segment(
2045 const char* version
,
2048 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
2049 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
2051 elfcpp::STB binding
,
2052 elfcpp::STV visibility
,
2053 unsigned char nonvis
,
2054 Symbol::Segment_offset_base offset_base
,
2057 Sized_symbol
<size
>* sym
;
2058 Sized_symbol
<size
>* oldsym
;
2059 bool resolve_oldsym
;
2061 if (parameters
->target().is_big_endian())
2063 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2064 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
2065 only_if_ref
, &oldsym
,
2073 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2074 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
2075 only_if_ref
, &oldsym
,
2085 sym
->init_output_segment(name
, version
, os
, value
, symsize
, type
, binding
,
2086 visibility
, nonvis
, offset_base
,
2087 defined
== PREDEFINED
);
2091 if (binding
== elfcpp::STB_LOCAL
2092 || this->version_script_
.symbol_is_local(name
))
2093 this->force_local(sym
);
2094 else if (version
!= NULL
)
2095 sym
->set_is_default();
2099 if (Symbol_table::should_override_with_special(oldsym
, type
, defined
))
2100 this->override_with_special(oldsym
, sym
);
2106 if (binding
== elfcpp::STB_LOCAL
2107 || this->version_script_
.symbol_is_local(name
))
2108 this->force_local(oldsym
);
2114 // Define a special symbol with a constant value. It is a multiple
2115 // definition error if this symbol is already defined.
2118 Symbol_table::define_as_constant(const char* name
,
2119 const char* version
,
2124 elfcpp::STB binding
,
2125 elfcpp::STV visibility
,
2126 unsigned char nonvis
,
2128 bool force_override
)
2130 if (parameters
->target().get_size() == 32)
2132 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2133 return this->do_define_as_constant
<32>(name
, version
, defined
, value
,
2134 symsize
, type
, binding
,
2135 visibility
, nonvis
, only_if_ref
,
2141 else if (parameters
->target().get_size() == 64)
2143 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2144 return this->do_define_as_constant
<64>(name
, version
, defined
, value
,
2145 symsize
, type
, binding
,
2146 visibility
, nonvis
, only_if_ref
,
2156 // Define a symbol as a constant, sized version.
2160 Symbol_table::do_define_as_constant(
2162 const char* version
,
2164 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
2165 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
2167 elfcpp::STB binding
,
2168 elfcpp::STV visibility
,
2169 unsigned char nonvis
,
2171 bool force_override
)
2173 Sized_symbol
<size
>* sym
;
2174 Sized_symbol
<size
>* oldsym
;
2175 bool resolve_oldsym
;
2177 if (parameters
->target().is_big_endian())
2179 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2180 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
2181 only_if_ref
, &oldsym
,
2189 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2190 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
2191 only_if_ref
, &oldsym
,
2201 sym
->init_constant(name
, version
, value
, symsize
, type
, binding
, visibility
,
2202 nonvis
, defined
== PREDEFINED
);
2206 // Version symbols are absolute symbols with name == version.
2207 // We don't want to force them to be local.
2208 if ((version
== NULL
2211 && (binding
== elfcpp::STB_LOCAL
2212 || this->version_script_
.symbol_is_local(name
)))
2213 this->force_local(sym
);
2214 else if (version
!= NULL
2215 && (name
!= version
|| value
!= 0))
2216 sym
->set_is_default();
2221 || Symbol_table::should_override_with_special(oldsym
, type
, defined
))
2222 this->override_with_special(oldsym
, sym
);
2228 if (binding
== elfcpp::STB_LOCAL
2229 || this->version_script_
.symbol_is_local(name
))
2230 this->force_local(oldsym
);
2236 // Define a set of symbols in output sections.
2239 Symbol_table::define_symbols(const Layout
* layout
, int count
,
2240 const Define_symbol_in_section
* p
,
2243 for (int i
= 0; i
< count
; ++i
, ++p
)
2245 Output_section
* os
= layout
->find_output_section(p
->output_section
);
2247 this->define_in_output_data(p
->name
, NULL
, PREDEFINED
, os
, p
->value
,
2248 p
->size
, p
->type
, p
->binding
,
2249 p
->visibility
, p
->nonvis
,
2250 p
->offset_is_from_end
,
2251 only_if_ref
|| p
->only_if_ref
);
2253 this->define_as_constant(p
->name
, NULL
, PREDEFINED
, 0, p
->size
,
2254 p
->type
, p
->binding
, p
->visibility
, p
->nonvis
,
2255 only_if_ref
|| p
->only_if_ref
,
2260 // Define a set of symbols in output segments.
2263 Symbol_table::define_symbols(const Layout
* layout
, int count
,
2264 const Define_symbol_in_segment
* p
,
2267 for (int i
= 0; i
< count
; ++i
, ++p
)
2269 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
2270 p
->segment_flags_set
,
2271 p
->segment_flags_clear
);
2273 this->define_in_output_segment(p
->name
, NULL
, PREDEFINED
, os
, p
->value
,
2274 p
->size
, p
->type
, p
->binding
,
2275 p
->visibility
, p
->nonvis
,
2277 only_if_ref
|| p
->only_if_ref
);
2279 this->define_as_constant(p
->name
, NULL
, PREDEFINED
, 0, p
->size
,
2280 p
->type
, p
->binding
, p
->visibility
, p
->nonvis
,
2281 only_if_ref
|| p
->only_if_ref
,
2286 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2287 // symbol should be defined--typically a .dyn.bss section. VALUE is
2288 // the offset within POSD.
2292 Symbol_table::define_with_copy_reloc(
2293 Sized_symbol
<size
>* csym
,
2295 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
2297 gold_assert(csym
->is_from_dynobj());
2298 gold_assert(!csym
->is_copied_from_dynobj());
2299 Object
* object
= csym
->object();
2300 gold_assert(object
->is_dynamic());
2301 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
2303 // Our copied variable has to override any variable in a shared
2305 elfcpp::STB binding
= csym
->binding();
2306 if (binding
== elfcpp::STB_WEAK
)
2307 binding
= elfcpp::STB_GLOBAL
;
2309 this->define_in_output_data(csym
->name(), csym
->version(), COPY
,
2310 posd
, value
, csym
->symsize(),
2311 csym
->type(), binding
,
2312 csym
->visibility(), csym
->nonvis(),
2315 csym
->set_is_copied_from_dynobj();
2316 csym
->set_needs_dynsym_entry();
2318 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
2320 // We have now defined all aliases, but we have not entered them all
2321 // in the copied_symbol_dynobjs_ map.
2322 if (csym
->has_alias())
2327 sym
= this->weak_aliases_
[sym
];
2330 gold_assert(sym
->output_data() == posd
);
2332 sym
->set_is_copied_from_dynobj();
2333 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
2338 // SYM is defined using a COPY reloc. Return the dynamic object where
2339 // the original definition was found.
2342 Symbol_table::get_copy_source(const Symbol
* sym
) const
2344 gold_assert(sym
->is_copied_from_dynobj());
2345 Copied_symbol_dynobjs::const_iterator p
=
2346 this->copied_symbol_dynobjs_
.find(sym
);
2347 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
2351 // Add any undefined symbols named on the command line.
2354 Symbol_table::add_undefined_symbols_from_command_line(Layout
* layout
)
2356 if (parameters
->options().any_undefined()
2357 || layout
->script_options()->any_unreferenced())
2359 if (parameters
->target().get_size() == 32)
2361 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2362 this->do_add_undefined_symbols_from_command_line
<32>(layout
);
2367 else if (parameters
->target().get_size() == 64)
2369 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2370 this->do_add_undefined_symbols_from_command_line
<64>(layout
);
2382 Symbol_table::do_add_undefined_symbols_from_command_line(Layout
* layout
)
2384 for (options::String_set::const_iterator p
=
2385 parameters
->options().undefined_begin();
2386 p
!= parameters
->options().undefined_end();
2388 this->add_undefined_symbol_from_command_line
<size
>(p
->c_str());
2390 for (options::String_set::const_iterator p
=
2391 parameters
->options().export_dynamic_symbol_begin();
2392 p
!= parameters
->options().export_dynamic_symbol_end();
2394 this->add_undefined_symbol_from_command_line
<size
>(p
->c_str());
2396 for (Script_options::referenced_const_iterator p
=
2397 layout
->script_options()->referenced_begin();
2398 p
!= layout
->script_options()->referenced_end();
2400 this->add_undefined_symbol_from_command_line
<size
>(p
->c_str());
2405 Symbol_table::add_undefined_symbol_from_command_line(const char* name
)
2407 if (this->lookup(name
) != NULL
)
2410 const char* version
= NULL
;
2412 Sized_symbol
<size
>* sym
;
2413 Sized_symbol
<size
>* oldsym
;
2414 bool resolve_oldsym
;
2415 if (parameters
->target().is_big_endian())
2417 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2418 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
2427 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2428 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
2436 gold_assert(oldsym
== NULL
);
2438 sym
->init_undefined(name
, version
, elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
2439 elfcpp::STV_DEFAULT
, 0);
2440 ++this->saw_undefined_
;
2443 // Set the dynamic symbol indexes. INDEX is the index of the first
2444 // global dynamic symbol. Pointers to the symbols are stored into the
2445 // vector SYMS. The names are added to DYNPOOL. This returns an
2446 // updated dynamic symbol index.
2449 Symbol_table::set_dynsym_indexes(unsigned int index
,
2450 std::vector
<Symbol
*>* syms
,
2451 Stringpool
* dynpool
,
2454 std::vector
<Symbol
*> as_needed_sym
;
2456 // Allow a target to set dynsym indexes.
2457 if (parameters
->target().has_custom_set_dynsym_indexes())
2459 std::vector
<Symbol
*> dyn_symbols
;
2460 for (Symbol_table_type::iterator p
= this->table_
.begin();
2461 p
!= this->table_
.end();
2464 Symbol
* sym
= p
->second
;
2465 if (!sym
->should_add_dynsym_entry(this))
2466 sym
->set_dynsym_index(-1U);
2468 dyn_symbols
.push_back(sym
);
2471 return parameters
->target().set_dynsym_indexes(&dyn_symbols
, index
, syms
,
2472 dynpool
, versions
, this);
2475 for (Symbol_table_type::iterator p
= this->table_
.begin();
2476 p
!= this->table_
.end();
2479 Symbol
* sym
= p
->second
;
2481 // Note that SYM may already have a dynamic symbol index, since
2482 // some symbols appear more than once in the symbol table, with
2483 // and without a version.
2485 if (!sym
->should_add_dynsym_entry(this))
2486 sym
->set_dynsym_index(-1U);
2487 else if (!sym
->has_dynsym_index())
2489 sym
->set_dynsym_index(index
);
2491 syms
->push_back(sym
);
2492 dynpool
->add(sym
->name(), false, NULL
);
2494 // If the symbol is defined in a dynamic object and is
2495 // referenced strongly in a regular object, then mark the
2496 // dynamic object as needed. This is used to implement
2498 if (sym
->is_from_dynobj()
2500 && !sym
->is_undef_binding_weak())
2501 sym
->object()->set_is_needed();
2503 // Record any version information, except those from
2504 // as-needed libraries not seen to be needed. Note that the
2505 // is_needed state for such libraries can change in this loop.
2506 if (sym
->version() != NULL
)
2508 if (!sym
->is_from_dynobj()
2509 || !sym
->object()->as_needed()
2510 || sym
->object()->is_needed())
2511 versions
->record_version(this, dynpool
, sym
);
2513 as_needed_sym
.push_back(sym
);
2518 // Process version information for symbols from as-needed libraries.
2519 for (std::vector
<Symbol
*>::iterator p
= as_needed_sym
.begin();
2520 p
!= as_needed_sym
.end();
2525 if (sym
->object()->is_needed())
2526 versions
->record_version(this, dynpool
, sym
);
2528 sym
->clear_version();
2531 // Finish up the versions. In some cases this may add new dynamic
2533 index
= versions
->finalize(this, index
, syms
);
2538 // Set the final values for all the symbols. The index of the first
2539 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2540 // file offset OFF. Add their names to POOL. Return the new file
2541 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2544 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
2545 size_t dyncount
, Stringpool
* pool
,
2546 unsigned int* plocal_symcount
)
2550 gold_assert(*plocal_symcount
!= 0);
2551 this->first_global_index_
= *plocal_symcount
;
2553 this->dynamic_offset_
= dynoff
;
2554 this->first_dynamic_global_index_
= dyn_global_index
;
2555 this->dynamic_count_
= dyncount
;
2557 if (parameters
->target().get_size() == 32)
2559 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2560 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
2565 else if (parameters
->target().get_size() == 64)
2567 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2568 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
2576 // Now that we have the final symbol table, we can reliably note
2577 // which symbols should get warnings.
2578 this->warnings_
.note_warnings(this);
2583 // SYM is going into the symbol table at *PINDEX. Add the name to
2584 // POOL, update *PINDEX and *POFF.
2588 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
2589 unsigned int* pindex
, off_t
* poff
)
2591 sym
->set_symtab_index(*pindex
);
2592 if (sym
->version() == NULL
|| !parameters
->options().relocatable())
2593 pool
->add(sym
->name(), false, NULL
);
2595 pool
->add(sym
->versioned_name(), true, NULL
);
2597 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
2600 // Set the final value for all the symbols. This is called after
2601 // Layout::finalize, so all the output sections have their final
2606 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
2607 unsigned int* plocal_symcount
)
2609 off
= align_address(off
, size
>> 3);
2610 this->offset_
= off
;
2612 unsigned int index
= *plocal_symcount
;
2613 const unsigned int orig_index
= index
;
2615 // First do all the symbols which have been forced to be local, as
2616 // they must appear before all global symbols.
2617 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
2618 p
!= this->forced_locals_
.end();
2622 gold_assert(sym
->is_forced_local());
2623 if (this->sized_finalize_symbol
<size
>(sym
))
2625 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
2630 // Now do all the remaining symbols.
2631 for (Symbol_table_type::iterator p
= this->table_
.begin();
2632 p
!= this->table_
.end();
2635 Symbol
* sym
= p
->second
;
2636 if (this->sized_finalize_symbol
<size
>(sym
))
2637 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
2640 this->output_count_
= index
- orig_index
;
2645 // Compute the final value of SYM and store status in location PSTATUS.
2646 // During relaxation, this may be called multiple times for a symbol to
2647 // compute its would-be final value in each relaxation pass.
2650 typename Sized_symbol
<size
>::Value_type
2651 Symbol_table::compute_final_value(
2652 const Sized_symbol
<size
>* sym
,
2653 Compute_final_value_status
* pstatus
) const
2655 typedef typename Sized_symbol
<size
>::Value_type Value_type
;
2658 switch (sym
->source())
2660 case Symbol::FROM_OBJECT
:
2663 unsigned int shndx
= sym
->shndx(&is_ordinary
);
2666 && shndx
!= elfcpp::SHN_ABS
2667 && !Symbol::is_common_shndx(shndx
))
2669 *pstatus
= CFVS_UNSUPPORTED_SYMBOL_SECTION
;
2673 Object
* symobj
= sym
->object();
2674 if (symobj
->is_dynamic())
2677 shndx
= elfcpp::SHN_UNDEF
;
2679 else if (symobj
->pluginobj() != NULL
)
2682 shndx
= elfcpp::SHN_UNDEF
;
2684 else if (shndx
== elfcpp::SHN_UNDEF
)
2686 else if (!is_ordinary
2687 && (shndx
== elfcpp::SHN_ABS
2688 || Symbol::is_common_shndx(shndx
)))
2689 value
= sym
->value();
2692 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
2693 Output_section
* os
= relobj
->output_section(shndx
);
2695 if (this->is_section_folded(relobj
, shndx
))
2697 gold_assert(os
== NULL
);
2698 // Get the os of the section it is folded onto.
2699 Section_id folded
= this->icf_
->get_folded_section(relobj
,
2701 gold_assert(folded
.first
!= NULL
);
2702 Relobj
* folded_obj
= reinterpret_cast<Relobj
*>(folded
.first
);
2703 unsigned folded_shndx
= folded
.second
;
2705 os
= folded_obj
->output_section(folded_shndx
);
2706 gold_assert(os
!= NULL
);
2708 // Replace (relobj, shndx) with canonical ICF input section.
2709 shndx
= folded_shndx
;
2710 relobj
= folded_obj
;
2713 uint64_t secoff64
= relobj
->output_section_offset(shndx
);
2716 bool static_or_reloc
= (parameters
->doing_static_link() ||
2717 parameters
->options().relocatable());
2718 gold_assert(static_or_reloc
|| sym
->dynsym_index() == -1U);
2720 *pstatus
= CFVS_NO_OUTPUT_SECTION
;
2724 if (secoff64
== -1ULL)
2726 // The section needs special handling (e.g., a merge section).
2728 value
= os
->output_address(relobj
, shndx
, sym
->value());
2733 convert_types
<Value_type
, uint64_t>(secoff64
);
2734 if (sym
->type() == elfcpp::STT_TLS
)
2735 value
= sym
->value() + os
->tls_offset() + secoff
;
2737 value
= sym
->value() + os
->address() + secoff
;
2743 case Symbol::IN_OUTPUT_DATA
:
2745 Output_data
* od
= sym
->output_data();
2746 value
= sym
->value();
2747 if (sym
->type() != elfcpp::STT_TLS
)
2748 value
+= od
->address();
2751 Output_section
* os
= od
->output_section();
2752 gold_assert(os
!= NULL
);
2753 value
+= os
->tls_offset() + (od
->address() - os
->address());
2755 if (sym
->offset_is_from_end())
2756 value
+= od
->data_size();
2760 case Symbol::IN_OUTPUT_SEGMENT
:
2762 Output_segment
* os
= sym
->output_segment();
2763 value
= sym
->value();
2764 if (sym
->type() != elfcpp::STT_TLS
)
2765 value
+= os
->vaddr();
2766 switch (sym
->offset_base())
2768 case Symbol::SEGMENT_START
:
2770 case Symbol::SEGMENT_END
:
2771 value
+= os
->memsz();
2773 case Symbol::SEGMENT_BSS
:
2774 value
+= os
->filesz();
2782 case Symbol::IS_CONSTANT
:
2783 value
= sym
->value();
2786 case Symbol::IS_UNDEFINED
:
2798 // Finalize the symbol SYM. This returns true if the symbol should be
2799 // added to the symbol table, false otherwise.
2803 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
2805 typedef typename Sized_symbol
<size
>::Value_type Value_type
;
2807 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
2809 // The default version of a symbol may appear twice in the symbol
2810 // table. We only need to finalize it once.
2811 if (sym
->has_symtab_index())
2816 gold_assert(!sym
->has_symtab_index());
2817 sym
->set_symtab_index(-1U);
2818 gold_assert(sym
->dynsym_index() == -1U);
2822 // If the symbol is only present on plugin files, the plugin decided we
2824 if (!sym
->in_real_elf())
2826 gold_assert(!sym
->has_symtab_index());
2827 sym
->set_symtab_index(-1U);
2831 // Compute final symbol value.
2832 Compute_final_value_status status
;
2833 Value_type value
= this->compute_final_value(sym
, &status
);
2839 case CFVS_UNSUPPORTED_SYMBOL_SECTION
:
2842 unsigned int shndx
= sym
->shndx(&is_ordinary
);
2843 gold_error(_("%s: unsupported symbol section 0x%x"),
2844 sym
->demangled_name().c_str(), shndx
);
2847 case CFVS_NO_OUTPUT_SECTION
:
2848 sym
->set_symtab_index(-1U);
2854 sym
->set_value(value
);
2856 if (parameters
->options().strip_all()
2857 || !parameters
->options().should_retain_symbol(sym
->name()))
2859 sym
->set_symtab_index(-1U);
2866 // Write out the global symbols.
2869 Symbol_table::write_globals(const Stringpool
* sympool
,
2870 const Stringpool
* dynpool
,
2871 Output_symtab_xindex
* symtab_xindex
,
2872 Output_symtab_xindex
* dynsym_xindex
,
2873 Output_file
* of
) const
2875 switch (parameters
->size_and_endianness())
2877 #ifdef HAVE_TARGET_32_LITTLE
2878 case Parameters::TARGET_32_LITTLE
:
2879 this->sized_write_globals
<32, false>(sympool
, dynpool
, symtab_xindex
,
2883 #ifdef HAVE_TARGET_32_BIG
2884 case Parameters::TARGET_32_BIG
:
2885 this->sized_write_globals
<32, true>(sympool
, dynpool
, symtab_xindex
,
2889 #ifdef HAVE_TARGET_64_LITTLE
2890 case Parameters::TARGET_64_LITTLE
:
2891 this->sized_write_globals
<64, false>(sympool
, dynpool
, symtab_xindex
,
2895 #ifdef HAVE_TARGET_64_BIG
2896 case Parameters::TARGET_64_BIG
:
2897 this->sized_write_globals
<64, true>(sympool
, dynpool
, symtab_xindex
,
2906 // Write out the global symbols.
2908 template<int size
, bool big_endian
>
2910 Symbol_table::sized_write_globals(const Stringpool
* sympool
,
2911 const Stringpool
* dynpool
,
2912 Output_symtab_xindex
* symtab_xindex
,
2913 Output_symtab_xindex
* dynsym_xindex
,
2914 Output_file
* of
) const
2916 const Target
& target
= parameters
->target();
2918 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2920 const unsigned int output_count
= this->output_count_
;
2921 const section_size_type oview_size
= output_count
* sym_size
;
2922 const unsigned int first_global_index
= this->first_global_index_
;
2923 unsigned char* psyms
;
2924 if (this->offset_
== 0 || output_count
== 0)
2927 psyms
= of
->get_output_view(this->offset_
, oview_size
);
2929 const unsigned int dynamic_count
= this->dynamic_count_
;
2930 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
2931 const unsigned int first_dynamic_global_index
=
2932 this->first_dynamic_global_index_
;
2933 unsigned char* dynamic_view
;
2934 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
2935 dynamic_view
= NULL
;
2937 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
2939 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
2940 p
!= this->table_
.end();
2943 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
2945 // Possibly warn about unresolved symbols in shared libraries.
2946 this->warn_about_undefined_dynobj_symbol(sym
);
2948 unsigned int sym_index
= sym
->symtab_index();
2949 unsigned int dynsym_index
;
2950 if (dynamic_view
== NULL
)
2953 dynsym_index
= sym
->dynsym_index();
2955 if (sym_index
== -1U && dynsym_index
== -1U)
2957 // This symbol is not included in the output file.
2962 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
2963 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
2964 elfcpp::STB binding
= sym
->binding();
2966 // If --weak-unresolved-symbols is set, change binding of unresolved
2967 // global symbols to STB_WEAK.
2968 if (parameters
->options().weak_unresolved_symbols()
2969 && binding
== elfcpp::STB_GLOBAL
2970 && sym
->is_undefined())
2971 binding
= elfcpp::STB_WEAK
;
2973 // If --no-gnu-unique is set, change STB_GNU_UNIQUE to STB_GLOBAL.
2974 if (binding
== elfcpp::STB_GNU_UNIQUE
2975 && !parameters
->options().gnu_unique())
2976 binding
= elfcpp::STB_GLOBAL
;
2978 switch (sym
->source())
2980 case Symbol::FROM_OBJECT
:
2983 unsigned int in_shndx
= sym
->shndx(&is_ordinary
);
2986 && in_shndx
!= elfcpp::SHN_ABS
2987 && !Symbol::is_common_shndx(in_shndx
))
2989 gold_error(_("%s: unsupported symbol section 0x%x"),
2990 sym
->demangled_name().c_str(), in_shndx
);
2995 Object
* symobj
= sym
->object();
2996 if (symobj
->is_dynamic())
2998 if (sym
->needs_dynsym_value())
2999 dynsym_value
= target
.dynsym_value(sym
);
3000 shndx
= elfcpp::SHN_UNDEF
;
3001 if (sym
->is_undef_binding_weak())
3002 binding
= elfcpp::STB_WEAK
;
3004 binding
= elfcpp::STB_GLOBAL
;
3006 else if (symobj
->pluginobj() != NULL
)
3007 shndx
= elfcpp::SHN_UNDEF
;
3008 else if (in_shndx
== elfcpp::SHN_UNDEF
3010 && (in_shndx
== elfcpp::SHN_ABS
3011 || Symbol::is_common_shndx(in_shndx
))))
3015 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
3016 Output_section
* os
= relobj
->output_section(in_shndx
);
3017 if (this->is_section_folded(relobj
, in_shndx
))
3019 // This global symbol must be written out even though
3021 // Get the os of the section it is folded onto.
3023 this->icf_
->get_folded_section(relobj
, in_shndx
);
3024 gold_assert(folded
.first
!=NULL
);
3025 Relobj
* folded_obj
=
3026 reinterpret_cast<Relobj
*>(folded
.first
);
3027 os
= folded_obj
->output_section(folded
.second
);
3028 gold_assert(os
!= NULL
);
3030 gold_assert(os
!= NULL
);
3031 shndx
= os
->out_shndx();
3033 if (shndx
>= elfcpp::SHN_LORESERVE
)
3035 if (sym_index
!= -1U)
3036 symtab_xindex
->add(sym_index
, shndx
);
3037 if (dynsym_index
!= -1U)
3038 dynsym_xindex
->add(dynsym_index
, shndx
);
3039 shndx
= elfcpp::SHN_XINDEX
;
3042 // In object files symbol values are section
3044 if (parameters
->options().relocatable())
3045 sym_value
-= os
->address();
3051 case Symbol::IN_OUTPUT_DATA
:
3053 Output_data
* od
= sym
->output_data();
3055 shndx
= od
->out_shndx();
3056 if (shndx
>= elfcpp::SHN_LORESERVE
)
3058 if (sym_index
!= -1U)
3059 symtab_xindex
->add(sym_index
, shndx
);
3060 if (dynsym_index
!= -1U)
3061 dynsym_xindex
->add(dynsym_index
, shndx
);
3062 shndx
= elfcpp::SHN_XINDEX
;
3065 // In object files symbol values are section
3067 if (parameters
->options().relocatable())
3068 sym_value
-= od
->address();
3072 case Symbol::IN_OUTPUT_SEGMENT
:
3073 shndx
= elfcpp::SHN_ABS
;
3076 case Symbol::IS_CONSTANT
:
3077 shndx
= elfcpp::SHN_ABS
;
3080 case Symbol::IS_UNDEFINED
:
3081 shndx
= elfcpp::SHN_UNDEF
;
3088 if (sym_index
!= -1U)
3090 sym_index
-= first_global_index
;
3091 gold_assert(sym_index
< output_count
);
3092 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
3093 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
3094 binding
, sympool
, ps
);
3097 if (dynsym_index
!= -1U)
3099 dynsym_index
-= first_dynamic_global_index
;
3100 gold_assert(dynsym_index
< dynamic_count
);
3101 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
3102 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
3103 binding
, dynpool
, pd
);
3104 // Allow a target to adjust dynamic symbol value.
3105 parameters
->target().adjust_dyn_symbol(sym
, pd
);
3109 of
->write_output_view(this->offset_
, oview_size
, psyms
);
3110 if (dynamic_view
!= NULL
)
3111 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
3114 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
3115 // strtab holding the name.
3117 template<int size
, bool big_endian
>
3119 Symbol_table::sized_write_symbol(
3120 Sized_symbol
<size
>* sym
,
3121 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
3123 elfcpp::STB binding
,
3124 const Stringpool
* pool
,
3125 unsigned char* p
) const
3127 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
3128 if (sym
->version() == NULL
|| !parameters
->options().relocatable())
3129 osym
.put_st_name(pool
->get_offset(sym
->name()));
3131 osym
.put_st_name(pool
->get_offset(sym
->versioned_name()));
3132 osym
.put_st_value(value
);
3133 // Use a symbol size of zero for undefined symbols from shared libraries.
3134 if (shndx
== elfcpp::SHN_UNDEF
&& sym
->is_from_dynobj())
3135 osym
.put_st_size(0);
3137 osym
.put_st_size(sym
->symsize());
3138 elfcpp::STT type
= sym
->type();
3139 gold_assert(type
!= elfcpp::STT_GNU_IFUNC
|| !sym
->is_from_dynobj());
3140 // A version script may have overridden the default binding.
3141 if (sym
->is_forced_local())
3142 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, type
));
3144 osym
.put_st_info(elfcpp::elf_st_info(binding
, type
));
3145 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
3146 osym
.put_st_shndx(shndx
);
3149 // Check for unresolved symbols in shared libraries. This is
3150 // controlled by the --allow-shlib-undefined option.
3152 // We only warn about libraries for which we have seen all the
3153 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
3154 // which were not seen in this link. If we didn't see a DT_NEEDED
3155 // entry, we aren't going to be able to reliably report whether the
3156 // symbol is undefined.
3158 // We also don't warn about libraries found in a system library
3159 // directory (e.g., /lib or /usr/lib); we assume that those libraries
3160 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
3161 // can have undefined references satisfied by ld-linux.so.
3164 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol
* sym
) const
3167 if (sym
->source() == Symbol::FROM_OBJECT
3168 && sym
->object()->is_dynamic()
3169 && sym
->shndx(&dummy
) == elfcpp::SHN_UNDEF
3170 && sym
->binding() != elfcpp::STB_WEAK
3171 && !parameters
->options().allow_shlib_undefined()
3172 && !parameters
->target().is_defined_by_abi(sym
)
3173 && !sym
->object()->is_in_system_directory())
3175 // A very ugly cast.
3176 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
3177 if (!dynobj
->has_unknown_needed_entries())
3178 gold_undefined_symbol(sym
);
3182 // Write out a section symbol. Return the update offset.
3185 Symbol_table::write_section_symbol(const Output_section
* os
,
3186 Output_symtab_xindex
* symtab_xindex
,
3190 switch (parameters
->size_and_endianness())
3192 #ifdef HAVE_TARGET_32_LITTLE
3193 case Parameters::TARGET_32_LITTLE
:
3194 this->sized_write_section_symbol
<32, false>(os
, symtab_xindex
, of
,
3198 #ifdef HAVE_TARGET_32_BIG
3199 case Parameters::TARGET_32_BIG
:
3200 this->sized_write_section_symbol
<32, true>(os
, symtab_xindex
, of
,
3204 #ifdef HAVE_TARGET_64_LITTLE
3205 case Parameters::TARGET_64_LITTLE
:
3206 this->sized_write_section_symbol
<64, false>(os
, symtab_xindex
, of
,
3210 #ifdef HAVE_TARGET_64_BIG
3211 case Parameters::TARGET_64_BIG
:
3212 this->sized_write_section_symbol
<64, true>(os
, symtab_xindex
, of
,
3221 // Write out a section symbol, specialized for size and endianness.
3223 template<int size
, bool big_endian
>
3225 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
3226 Output_symtab_xindex
* symtab_xindex
,
3230 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
3232 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
3234 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
3235 osym
.put_st_name(0);
3236 if (parameters
->options().relocatable())
3237 osym
.put_st_value(0);
3239 osym
.put_st_value(os
->address());
3240 osym
.put_st_size(0);
3241 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
3242 elfcpp::STT_SECTION
));
3243 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
3245 unsigned int shndx
= os
->out_shndx();
3246 if (shndx
>= elfcpp::SHN_LORESERVE
)
3248 symtab_xindex
->add(os
->symtab_index(), shndx
);
3249 shndx
= elfcpp::SHN_XINDEX
;
3251 osym
.put_st_shndx(shndx
);
3253 of
->write_output_view(offset
, sym_size
, pov
);
3256 // Print statistical information to stderr. This is used for --stats.
3259 Symbol_table::print_stats() const
3261 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
3262 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
3263 program_name
, this->table_
.size(), this->table_
.bucket_count());
3265 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
3266 program_name
, this->table_
.size());
3268 this->namepool_
.print_stats("symbol table stringpool");
3271 // We check for ODR violations by looking for symbols with the same
3272 // name for which the debugging information reports that they were
3273 // defined in disjoint source locations. When comparing the source
3274 // location, we consider instances with the same base filename to be
3275 // the same. This is because different object files/shared libraries
3276 // can include the same header file using different paths, and
3277 // different optimization settings can make the line number appear to
3278 // be a couple lines off, and we don't want to report an ODR violation
3281 // This struct is used to compare line information, as returned by
3282 // Dwarf_line_info::one_addr2line. It implements a < comparison
3283 // operator used with std::sort.
3285 struct Odr_violation_compare
3288 operator()(const std::string
& s1
, const std::string
& s2
) const
3290 // Inputs should be of the form "dirname/filename:linenum" where
3291 // "dirname/" is optional. We want to compare just the filename:linenum.
3293 // Find the last '/' in each string.
3294 std::string::size_type s1begin
= s1
.rfind('/');
3295 std::string::size_type s2begin
= s2
.rfind('/');
3296 // If there was no '/' in a string, start at the beginning.
3297 if (s1begin
== std::string::npos
)
3299 if (s2begin
== std::string::npos
)
3301 return s1
.compare(s1begin
, std::string::npos
,
3302 s2
, s2begin
, std::string::npos
) < 0;
3306 // Returns all of the lines attached to LOC, not just the one the
3307 // instruction actually came from.
3308 std::vector
<std::string
>
3309 Symbol_table::linenos_from_loc(const Task
* task
,
3310 const Symbol_location
& loc
)
3312 // We need to lock the object in order to read it. This
3313 // means that we have to run in a singleton Task. If we
3314 // want to run this in a general Task for better
3315 // performance, we will need one Task for object, plus
3316 // appropriate locking to ensure that we don't conflict with
3317 // other uses of the object. Also note, one_addr2line is not
3318 // currently thread-safe.
3319 Task_lock_obj
<Object
> tl(task
, loc
.object
);
3321 std::vector
<std::string
> result
;
3322 Symbol_location code_loc
= loc
;
3323 parameters
->target().function_location(&code_loc
);
3324 // 16 is the size of the object-cache that one_addr2line should use.
3325 std::string canonical_result
= Dwarf_line_info::one_addr2line(
3326 code_loc
.object
, code_loc
.shndx
, code_loc
.offset
, 16, &result
);
3327 if (!canonical_result
.empty())
3328 result
.push_back(canonical_result
);
3332 // OutputIterator that records if it was ever assigned to. This
3333 // allows it to be used with std::set_intersection() to check for
3334 // intersection rather than computing the intersection.
3335 struct Check_intersection
3337 Check_intersection()
3341 bool had_intersection() const
3342 { return this->value_
; }
3344 Check_intersection
& operator++()
3347 Check_intersection
& operator*()
3350 template<typename T
>
3351 Check_intersection
& operator=(const T
&)
3353 this->value_
= true;
3361 // Check candidate_odr_violations_ to find symbols with the same name
3362 // but apparently different definitions (different source-file/line-no
3363 // for each line assigned to the first instruction).
3366 Symbol_table::detect_odr_violations(const Task
* task
,
3367 const char* output_file_name
) const
3369 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
3370 it
!= candidate_odr_violations_
.end();
3373 const char* const symbol_name
= it
->first
;
3375 std::string first_object_name
;
3376 std::vector
<std::string
> first_object_linenos
;
3378 Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
3379 locs
= it
->second
.begin();
3380 const Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
3381 locs_end
= it
->second
.end();
3382 for (; locs
!= locs_end
&& first_object_linenos
.empty(); ++locs
)
3384 // Save the line numbers from the first definition to
3385 // compare to the other definitions. Ideally, we'd compare
3386 // every definition to every other, but we don't want to
3387 // take O(N^2) time to do this. This shortcut may cause
3388 // false negatives that appear or disappear depending on the
3389 // link order, but it won't cause false positives.
3390 first_object_name
= locs
->object
->name();
3391 first_object_linenos
= this->linenos_from_loc(task
, *locs
);
3393 if (first_object_linenos
.empty())
3396 // Sort by Odr_violation_compare to make std::set_intersection work.
3397 std::string first_object_canonical_result
= first_object_linenos
.back();
3398 std::sort(first_object_linenos
.begin(), first_object_linenos
.end(),
3399 Odr_violation_compare());
3401 for (; locs
!= locs_end
; ++locs
)
3403 std::vector
<std::string
> linenos
=
3404 this->linenos_from_loc(task
, *locs
);
3405 // linenos will be empty if we couldn't parse the debug info.
3406 if (linenos
.empty())
3408 // Sort by Odr_violation_compare to make std::set_intersection work.
3409 gold_assert(!linenos
.empty());
3410 std::string second_object_canonical_result
= linenos
.back();
3411 std::sort(linenos
.begin(), linenos
.end(), Odr_violation_compare());
3413 Check_intersection intersection_result
=
3414 std::set_intersection(first_object_linenos
.begin(),
3415 first_object_linenos
.end(),
3418 Check_intersection(),
3419 Odr_violation_compare());
3420 if (!intersection_result
.had_intersection())
3422 gold_warning(_("while linking %s: symbol '%s' defined in "
3423 "multiple places (possible ODR violation):"),
3424 output_file_name
, demangle(symbol_name
).c_str());
3425 // This only prints one location from each definition,
3426 // which may not be the location we expect to intersect
3427 // with another definition. We could print the whole
3428 // set of locations, but that seems too verbose.
3429 fprintf(stderr
, _(" %s from %s\n"),
3430 first_object_canonical_result
.c_str(),
3431 first_object_name
.c_str());
3432 fprintf(stderr
, _(" %s from %s\n"),
3433 second_object_canonical_result
.c_str(),
3434 locs
->object
->name().c_str());
3435 // Only print one broken pair, to avoid needing to
3436 // compare against a list of the disjoint definition
3437 // locations we've found so far. (If we kept comparing
3438 // against just the first one, we'd get a lot of
3439 // redundant complaints about the second definition
3445 // We only call one_addr2line() in this function, so we can clear its cache.
3446 Dwarf_line_info::clear_addr2line_cache();
3449 // Warnings functions.
3451 // Add a new warning.
3454 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
3455 const std::string
& warning
)
3457 name
= symtab
->canonicalize_name(name
);
3458 this->warnings_
[name
].set(obj
, warning
);
3461 // Look through the warnings and mark the symbols for which we should
3462 // warn. This is called during Layout::finalize when we know the
3463 // sources for all the symbols.
3466 Warnings::note_warnings(Symbol_table
* symtab
)
3468 for (Warning_table::iterator p
= this->warnings_
.begin();
3469 p
!= this->warnings_
.end();
3472 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
3474 && sym
->source() == Symbol::FROM_OBJECT
3475 && sym
->object() == p
->second
.object
)
3476 sym
->set_has_warning();
3480 // Issue a warning. This is called when we see a relocation against a
3481 // symbol for which has a warning.
3483 template<int size
, bool big_endian
>
3485 Warnings::issue_warning(const Symbol
* sym
,
3486 const Relocate_info
<size
, big_endian
>* relinfo
,
3487 size_t relnum
, off_t reloffset
) const
3489 gold_assert(sym
->has_warning());
3491 // We don't want to issue a warning for a relocation against the
3492 // symbol in the same object file in which the symbol is defined.
3493 if (sym
->object() == relinfo
->object
)
3496 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
3497 gold_assert(p
!= this->warnings_
.end());
3498 gold_warning_at_location(relinfo
, relnum
, reloffset
,
3499 "%s", p
->second
.text
.c_str());
3502 // Instantiate the templates we need. We could use the configure
3503 // script to restrict this to only the ones needed for implemented
3506 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3509 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
3512 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3515 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
3518 #ifdef HAVE_TARGET_32_LITTLE
3521 Symbol_table::add_from_relobj
<32, false>(
3522 Sized_relobj_file
<32, false>* relobj
,
3523 const unsigned char* syms
,
3525 size_t symndx_offset
,
3526 const char* sym_names
,
3527 size_t sym_name_size
,
3528 Sized_relobj_file
<32, false>::Symbols
* sympointers
,
3532 #ifdef HAVE_TARGET_32_BIG
3535 Symbol_table::add_from_relobj
<32, true>(
3536 Sized_relobj_file
<32, true>* relobj
,
3537 const unsigned char* syms
,
3539 size_t symndx_offset
,
3540 const char* sym_names
,
3541 size_t sym_name_size
,
3542 Sized_relobj_file
<32, true>::Symbols
* sympointers
,
3546 #ifdef HAVE_TARGET_64_LITTLE
3549 Symbol_table::add_from_relobj
<64, false>(
3550 Sized_relobj_file
<64, false>* relobj
,
3551 const unsigned char* syms
,
3553 size_t symndx_offset
,
3554 const char* sym_names
,
3555 size_t sym_name_size
,
3556 Sized_relobj_file
<64, false>::Symbols
* sympointers
,
3560 #ifdef HAVE_TARGET_64_BIG
3563 Symbol_table::add_from_relobj
<64, true>(
3564 Sized_relobj_file
<64, true>* relobj
,
3565 const unsigned char* syms
,
3567 size_t symndx_offset
,
3568 const char* sym_names
,
3569 size_t sym_name_size
,
3570 Sized_relobj_file
<64, true>::Symbols
* sympointers
,
3574 #ifdef HAVE_TARGET_32_LITTLE
3577 Symbol_table::add_from_pluginobj
<32, false>(
3578 Sized_pluginobj
<32, false>* obj
,
3581 elfcpp::Sym
<32, false>* sym
);
3584 #ifdef HAVE_TARGET_32_BIG
3587 Symbol_table::add_from_pluginobj
<32, true>(
3588 Sized_pluginobj
<32, true>* obj
,
3591 elfcpp::Sym
<32, true>* sym
);
3594 #ifdef HAVE_TARGET_64_LITTLE
3597 Symbol_table::add_from_pluginobj
<64, false>(
3598 Sized_pluginobj
<64, false>* obj
,
3601 elfcpp::Sym
<64, false>* sym
);
3604 #ifdef HAVE_TARGET_64_BIG
3607 Symbol_table::add_from_pluginobj
<64, true>(
3608 Sized_pluginobj
<64, true>* obj
,
3611 elfcpp::Sym
<64, true>* sym
);
3614 #ifdef HAVE_TARGET_32_LITTLE
3617 Symbol_table::add_from_dynobj
<32, false>(
3618 Sized_dynobj
<32, false>* dynobj
,
3619 const unsigned char* syms
,
3621 const char* sym_names
,
3622 size_t sym_name_size
,
3623 const unsigned char* versym
,
3625 const std::vector
<const char*>* version_map
,
3626 Sized_relobj_file
<32, false>::Symbols
* sympointers
,
3630 #ifdef HAVE_TARGET_32_BIG
3633 Symbol_table::add_from_dynobj
<32, true>(
3634 Sized_dynobj
<32, true>* dynobj
,
3635 const unsigned char* syms
,
3637 const char* sym_names
,
3638 size_t sym_name_size
,
3639 const unsigned char* versym
,
3641 const std::vector
<const char*>* version_map
,
3642 Sized_relobj_file
<32, true>::Symbols
* sympointers
,
3646 #ifdef HAVE_TARGET_64_LITTLE
3649 Symbol_table::add_from_dynobj
<64, false>(
3650 Sized_dynobj
<64, false>* dynobj
,
3651 const unsigned char* syms
,
3653 const char* sym_names
,
3654 size_t sym_name_size
,
3655 const unsigned char* versym
,
3657 const std::vector
<const char*>* version_map
,
3658 Sized_relobj_file
<64, false>::Symbols
* sympointers
,
3662 #ifdef HAVE_TARGET_64_BIG
3665 Symbol_table::add_from_dynobj
<64, true>(
3666 Sized_dynobj
<64, true>* dynobj
,
3667 const unsigned char* syms
,
3669 const char* sym_names
,
3670 size_t sym_name_size
,
3671 const unsigned char* versym
,
3673 const std::vector
<const char*>* version_map
,
3674 Sized_relobj_file
<64, true>::Symbols
* sympointers
,
3678 #ifdef HAVE_TARGET_32_LITTLE
3681 Symbol_table::add_from_incrobj(
3685 elfcpp::Sym
<32, false>* sym
);
3688 #ifdef HAVE_TARGET_32_BIG
3691 Symbol_table::add_from_incrobj(
3695 elfcpp::Sym
<32, true>* sym
);
3698 #ifdef HAVE_TARGET_64_LITTLE
3701 Symbol_table::add_from_incrobj(
3705 elfcpp::Sym
<64, false>* sym
);
3708 #ifdef HAVE_TARGET_64_BIG
3711 Symbol_table::add_from_incrobj(
3715 elfcpp::Sym
<64, true>* sym
);
3718 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3721 Symbol_table::define_with_copy_reloc
<32>(
3722 Sized_symbol
<32>* sym
,
3724 elfcpp::Elf_types
<32>::Elf_Addr value
);
3727 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3730 Symbol_table::define_with_copy_reloc
<64>(
3731 Sized_symbol
<64>* sym
,
3733 elfcpp::Elf_types
<64>::Elf_Addr value
);
3736 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3739 Sized_symbol
<32>::init_output_data(const char* name
, const char* version
,
3740 Output_data
* od
, Value_type value
,
3741 Size_type symsize
, elfcpp::STT type
,
3742 elfcpp::STB binding
,
3743 elfcpp::STV visibility
,
3744 unsigned char nonvis
,
3745 bool offset_is_from_end
,
3746 bool is_predefined
);
3749 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3752 Sized_symbol
<64>::init_output_data(const char* name
, const char* version
,
3753 Output_data
* od
, Value_type value
,
3754 Size_type symsize
, elfcpp::STT type
,
3755 elfcpp::STB binding
,
3756 elfcpp::STV visibility
,
3757 unsigned char nonvis
,
3758 bool offset_is_from_end
,
3759 bool is_predefined
);
3762 #ifdef HAVE_TARGET_32_LITTLE
3765 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
3766 const Relocate_info
<32, false>* relinfo
,
3767 size_t relnum
, off_t reloffset
) const;
3770 #ifdef HAVE_TARGET_32_BIG
3773 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
3774 const Relocate_info
<32, true>* relinfo
,
3775 size_t relnum
, off_t reloffset
) const;
3778 #ifdef HAVE_TARGET_64_LITTLE
3781 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
3782 const Relocate_info
<64, false>* relinfo
,
3783 size_t relnum
, off_t reloffset
) const;
3786 #ifdef HAVE_TARGET_64_BIG
3789 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
3790 const Relocate_info
<64, true>* relinfo
,
3791 size_t relnum
, off_t reloffset
) const;
3794 } // End namespace gold.