1 // symtab.cc -- the gold symbol table
3 // Copyright (C) 2006-2016 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 Value_type value
, elfcpp::STT type
,
289 elfcpp::STB binding
, elfcpp::STV visibility
,
290 unsigned char nonvis
)
292 this->init_base_undefined(name
, version
, type
, binding
, visibility
, nonvis
);
293 this->value_
= value
;
297 // Return an allocated string holding the symbol's name as
298 // name@version. This is used for relocatable links.
301 Symbol::versioned_name() const
303 gold_assert(this->version_
!= NULL
);
304 std::string ret
= this->name_
;
308 ret
+= this->version_
;
312 // Return true if SHNDX represents a common symbol.
315 Symbol::is_common_shndx(unsigned int shndx
)
317 return (shndx
== elfcpp::SHN_COMMON
318 || shndx
== parameters
->target().small_common_shndx()
319 || shndx
== parameters
->target().large_common_shndx());
322 // Allocate a common symbol.
326 Sized_symbol
<size
>::allocate_common(Output_data
* od
, Value_type value
)
328 this->allocate_base_common(od
);
329 this->value_
= value
;
332 // The ""'s around str ensure str is a string literal, so sizeof works.
333 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
335 // Return true if this symbol should be added to the dynamic symbol
339 Symbol::should_add_dynsym_entry(Symbol_table
* symtab
) const
341 // If the symbol is only present on plugin files, the plugin decided we
343 if (!this->in_real_elf())
346 // If the symbol is used by a dynamic relocation, we need to add it.
347 if (this->needs_dynsym_entry())
350 // If this symbol's section is not added, the symbol need not be added.
351 // The section may have been GCed. Note that export_dynamic is being
352 // overridden here. This should not be done for shared objects.
353 if (parameters
->options().gc_sections()
354 && !parameters
->options().shared()
355 && this->source() == Symbol::FROM_OBJECT
356 && !this->object()->is_dynamic())
358 Relobj
* relobj
= static_cast<Relobj
*>(this->object());
360 unsigned int shndx
= this->shndx(&is_ordinary
);
361 if (is_ordinary
&& shndx
!= elfcpp::SHN_UNDEF
362 && !relobj
->is_section_included(shndx
)
363 && !symtab
->is_section_folded(relobj
, shndx
))
367 // If the symbol was forced dynamic in a --dynamic-list file
368 // or an --export-dynamic-symbol option, add it.
369 if (!this->is_from_dynobj()
370 && (parameters
->options().in_dynamic_list(this->name())
371 || parameters
->options().is_export_dynamic_symbol(this->name())))
373 if (!this->is_forced_local())
375 gold_warning(_("Cannot export local symbol '%s'"),
376 this->demangled_name().c_str());
380 // If the symbol was forced local in a version script, do not add it.
381 if (this->is_forced_local())
384 // If dynamic-list-data was specified, add any STT_OBJECT.
385 if (parameters
->options().dynamic_list_data()
386 && !this->is_from_dynobj()
387 && this->type() == elfcpp::STT_OBJECT
)
390 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
391 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
392 if ((parameters
->options().dynamic_list_cpp_new()
393 || parameters
->options().dynamic_list_cpp_typeinfo())
394 && !this->is_from_dynobj())
396 // TODO(csilvers): We could probably figure out if we're an operator
397 // new/delete or typeinfo without the need to demangle.
398 char* demangled_name
= cplus_demangle(this->name(),
399 DMGL_ANSI
| DMGL_PARAMS
);
400 if (demangled_name
== NULL
)
402 // Not a C++ symbol, so it can't satisfy these flags
404 else if (parameters
->options().dynamic_list_cpp_new()
405 && (strprefix(demangled_name
, "operator new")
406 || strprefix(demangled_name
, "operator delete")))
408 free(demangled_name
);
411 else if (parameters
->options().dynamic_list_cpp_typeinfo()
412 && (strprefix(demangled_name
, "typeinfo name for")
413 || strprefix(demangled_name
, "typeinfo for")))
415 free(demangled_name
);
419 free(demangled_name
);
422 // If exporting all symbols or building a shared library,
423 // or the symbol should be globally unique (GNU_UNIQUE),
424 // and the symbol is defined in a regular object and is
425 // externally visible, we need to add it.
426 if ((parameters
->options().export_dynamic()
427 || parameters
->options().shared()
428 || (parameters
->options().gnu_unique()
429 && this->binding() == elfcpp::STB_GNU_UNIQUE
))
430 && !this->is_from_dynobj()
431 && !this->is_undefined()
432 && this->is_externally_visible())
438 // Return true if the final value of this symbol is known at link
442 Symbol::final_value_is_known() const
444 // If we are not generating an executable, then no final values are
445 // known, since they will change at runtime, with the exception of
446 // TLS symbols in a position-independent executable.
447 if ((parameters
->options().output_is_position_independent()
448 || parameters
->options().relocatable())
449 && !(this->type() == elfcpp::STT_TLS
450 && parameters
->options().pie()))
453 // If the symbol is not from an object file, and is not undefined,
454 // then it is defined, and known.
455 if (this->source_
!= FROM_OBJECT
)
457 if (this->source_
!= IS_UNDEFINED
)
462 // If the symbol is from a dynamic object, then the final value
464 if (this->object()->is_dynamic())
467 // If the symbol is not undefined (it is defined or common),
468 // then the final value is known.
469 if (!this->is_undefined())
473 // If the symbol is undefined, then whether the final value is known
474 // depends on whether we are doing a static link. If we are doing a
475 // dynamic link, then the final value could be filled in at runtime.
476 // This could reasonably be the case for a weak undefined symbol.
477 return parameters
->doing_static_link();
480 // Return the output section where this symbol is defined.
483 Symbol::output_section() const
485 switch (this->source_
)
489 unsigned int shndx
= this->u_
.from_object
.shndx
;
490 if (shndx
!= elfcpp::SHN_UNDEF
&& this->is_ordinary_shndx_
)
492 gold_assert(!this->u_
.from_object
.object
->is_dynamic());
493 gold_assert(this->u_
.from_object
.object
->pluginobj() == NULL
);
494 Relobj
* relobj
= static_cast<Relobj
*>(this->u_
.from_object
.object
);
495 return relobj
->output_section(shndx
);
501 return this->u_
.in_output_data
.output_data
->output_section();
503 case IN_OUTPUT_SEGMENT
:
513 // Set the symbol's output section. This is used for symbols defined
514 // in scripts. This should only be called after the symbol table has
518 Symbol::set_output_section(Output_section
* os
)
520 switch (this->source_
)
524 gold_assert(this->output_section() == os
);
527 this->source_
= IN_OUTPUT_DATA
;
528 this->u_
.in_output_data
.output_data
= os
;
529 this->u_
.in_output_data
.offset_is_from_end
= false;
531 case IN_OUTPUT_SEGMENT
:
538 // Set the symbol's output segment. This is used for pre-defined
539 // symbols whose segments aren't known until after layout is done
540 // (e.g., __ehdr_start).
543 Symbol::set_output_segment(Output_segment
* os
, Segment_offset_base base
)
545 gold_assert(this->is_predefined_
);
546 this->source_
= IN_OUTPUT_SEGMENT
;
547 this->u_
.in_output_segment
.output_segment
= os
;
548 this->u_
.in_output_segment
.offset_base
= base
;
551 // Set the symbol to undefined. This is used for pre-defined
552 // symbols whose segments aren't known until after layout is done
553 // (e.g., __ehdr_start).
556 Symbol::set_undefined()
558 this->source_
= IS_UNDEFINED
;
559 this->is_predefined_
= false;
562 // Class Symbol_table.
564 Symbol_table::Symbol_table(unsigned int count
,
565 const Version_script_info
& version_script
)
566 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
567 forwarders_(), commons_(), tls_commons_(), small_commons_(),
568 large_commons_(), forced_locals_(), warnings_(),
569 version_script_(version_script
), gc_(NULL
), icf_(NULL
),
572 namepool_
.reserve(count
);
575 Symbol_table::~Symbol_table()
579 // The symbol table key equality function. This is called with
583 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
584 const Symbol_table_key
& k2
) const
586 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
590 Symbol_table::is_section_folded(Relobj
* obj
, unsigned int shndx
) const
592 return (parameters
->options().icf_enabled()
593 && this->icf_
->is_section_folded(obj
, shndx
));
596 // For symbols that have been listed with a -u or --export-dynamic-symbol
597 // option, add them to the work list to avoid gc'ing them.
600 Symbol_table::gc_mark_undef_symbols(Layout
* layout
)
602 for (options::String_set::const_iterator p
=
603 parameters
->options().undefined_begin();
604 p
!= parameters
->options().undefined_end();
607 const char* name
= p
->c_str();
608 Symbol
* sym
= this->lookup(name
);
609 gold_assert(sym
!= NULL
);
610 if (sym
->source() == Symbol::FROM_OBJECT
611 && !sym
->object()->is_dynamic())
613 this->gc_mark_symbol(sym
);
617 for (options::String_set::const_iterator p
=
618 parameters
->options().export_dynamic_symbol_begin();
619 p
!= parameters
->options().export_dynamic_symbol_end();
622 const char* name
= p
->c_str();
623 Symbol
* sym
= this->lookup(name
);
624 // It's not an error if a symbol named by --export-dynamic-symbol
627 && sym
->source() == Symbol::FROM_OBJECT
628 && !sym
->object()->is_dynamic())
630 this->gc_mark_symbol(sym
);
634 for (Script_options::referenced_const_iterator p
=
635 layout
->script_options()->referenced_begin();
636 p
!= layout
->script_options()->referenced_end();
639 Symbol
* sym
= this->lookup(p
->c_str());
640 gold_assert(sym
!= NULL
);
641 if (sym
->source() == Symbol::FROM_OBJECT
642 && !sym
->object()->is_dynamic())
644 this->gc_mark_symbol(sym
);
650 Symbol_table::gc_mark_symbol(Symbol
* sym
)
652 // Add the object and section to the work list.
654 unsigned int shndx
= sym
->shndx(&is_ordinary
);
655 if (is_ordinary
&& shndx
!= elfcpp::SHN_UNDEF
&& !sym
->object()->is_dynamic())
657 gold_assert(this->gc_
!= NULL
);
658 Relobj
* relobj
= static_cast<Relobj
*>(sym
->object());
659 this->gc_
->worklist().push_back(Section_id(relobj
, shndx
));
661 parameters
->target().gc_mark_symbol(this, sym
);
664 // When doing garbage collection, keep symbols that have been seen in
667 Symbol_table::gc_mark_dyn_syms(Symbol
* sym
)
669 if (sym
->in_dyn() && sym
->source() == Symbol::FROM_OBJECT
670 && !sym
->object()->is_dynamic())
671 this->gc_mark_symbol(sym
);
674 // Make TO a symbol which forwards to FROM.
677 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
679 gold_assert(from
!= to
);
680 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
681 this->forwarders_
[from
] = to
;
682 from
->set_forwarder();
685 // Resolve the forwards from FROM, returning the real symbol.
688 Symbol_table::resolve_forwards(const Symbol
* from
) const
690 gold_assert(from
->is_forwarder());
691 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
692 this->forwarders_
.find(from
);
693 gold_assert(p
!= this->forwarders_
.end());
697 // Look up a symbol by name.
700 Symbol_table::lookup(const char* name
, const char* version
) const
702 Stringpool::Key name_key
;
703 name
= this->namepool_
.find(name
, &name_key
);
707 Stringpool::Key version_key
= 0;
710 version
= this->namepool_
.find(version
, &version_key
);
715 Symbol_table_key
key(name_key
, version_key
);
716 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
717 if (p
== this->table_
.end())
722 // Resolve a Symbol with another Symbol. This is only used in the
723 // unusual case where there are references to both an unversioned
724 // symbol and a symbol with a version, and we then discover that that
725 // version is the default version. Because this is unusual, we do
726 // this the slow way, by converting back to an ELF symbol.
728 template<int size
, bool big_endian
>
730 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
)
732 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
733 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
734 // We don't bother to set the st_name or the st_shndx field.
735 esym
.put_st_value(from
->value());
736 esym
.put_st_size(from
->symsize());
737 esym
.put_st_info(from
->binding(), from
->type());
738 esym
.put_st_other(from
->visibility(), from
->nonvis());
740 unsigned int shndx
= from
->shndx(&is_ordinary
);
741 this->resolve(to
, esym
.sym(), shndx
, is_ordinary
, shndx
, from
->object(),
742 from
->version(), true);
747 if (parameters
->options().gc_sections())
748 this->gc_mark_dyn_syms(to
);
751 // Record that a symbol is forced to be local by a version script or
755 Symbol_table::force_local(Symbol
* sym
)
757 if (!sym
->is_defined() && !sym
->is_common())
759 if (sym
->is_forced_local())
761 // We already got this one.
764 sym
->set_is_forced_local();
765 this->forced_locals_
.push_back(sym
);
768 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
769 // is only called for undefined symbols, when at least one --wrap
773 Symbol_table::wrap_symbol(const char* name
, Stringpool::Key
* name_key
)
775 // For some targets, we need to ignore a specific character when
776 // wrapping, and add it back later.
778 if (name
[0] == parameters
->target().wrap_char())
784 if (parameters
->options().is_wrap(name
))
786 // Turn NAME into __wrap_NAME.
793 // This will give us both the old and new name in NAMEPOOL_, but
794 // that is OK. Only the versions we need will wind up in the
795 // real string table in the output file.
796 return this->namepool_
.add(s
.c_str(), true, name_key
);
799 const char* const real_prefix
= "__real_";
800 const size_t real_prefix_length
= strlen(real_prefix
);
801 if (strncmp(name
, real_prefix
, real_prefix_length
) == 0
802 && parameters
->options().is_wrap(name
+ real_prefix_length
))
804 // Turn __real_NAME into NAME.
808 s
+= name
+ real_prefix_length
;
809 return this->namepool_
.add(s
.c_str(), true, name_key
);
815 // This is called when we see a symbol NAME/VERSION, and the symbol
816 // already exists in the symbol table, and VERSION is marked as being
817 // the default version. SYM is the NAME/VERSION symbol we just added.
818 // DEFAULT_IS_NEW is true if this is the first time we have seen the
819 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
821 template<int size
, bool big_endian
>
823 Symbol_table::define_default_version(Sized_symbol
<size
>* sym
,
825 Symbol_table_type::iterator pdef
)
829 // This is the first time we have seen NAME/NULL. Make
830 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
833 sym
->set_is_default();
835 else if (pdef
->second
== sym
)
837 // NAME/NULL already points to NAME/VERSION. Don't mark the
838 // symbol as the default if it is not already the default.
842 // This is the unfortunate case where we already have entries
843 // for both NAME/VERSION and NAME/NULL. We now see a symbol
844 // NAME/VERSION where VERSION is the default version. We have
845 // already resolved this new symbol with the existing
846 // NAME/VERSION symbol.
848 // It's possible that NAME/NULL and NAME/VERSION are both
849 // defined in regular objects. This can only happen if one
850 // object file defines foo and another defines foo@@ver. This
851 // is somewhat obscure, but we call it a multiple definition
854 // It's possible that NAME/NULL actually has a version, in which
855 // case it won't be the same as VERSION. This happens with
856 // ver_test_7.so in the testsuite for the symbol t2_2. We see
857 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
858 // then see an unadorned t2_2 in an object file and give it
859 // version VER1 from the version script. This looks like a
860 // default definition for VER1, so it looks like we should merge
861 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
862 // not obvious that this is an error, either. So we just punt.
864 // If one of the symbols has non-default visibility, and the
865 // other is defined in a shared object, then they are different
868 // Otherwise, we just resolve the symbols as though they were
871 if (pdef
->second
->version() != NULL
)
872 gold_assert(pdef
->second
->version() != sym
->version());
873 else if (sym
->visibility() != elfcpp::STV_DEFAULT
874 && pdef
->second
->is_from_dynobj())
876 else if (pdef
->second
->visibility() != elfcpp::STV_DEFAULT
877 && sym
->is_from_dynobj())
881 const Sized_symbol
<size
>* symdef
;
882 symdef
= this->get_sized_symbol
<size
>(pdef
->second
);
883 Symbol_table::resolve
<size
, big_endian
>(sym
, symdef
);
884 this->make_forwarder(pdef
->second
, sym
);
886 sym
->set_is_default();
891 // Add one symbol from OBJECT to the symbol table. NAME is symbol
892 // name and VERSION is the version; both are canonicalized. DEF is
893 // whether this is the default version. ST_SHNDX is the symbol's
894 // section index; IS_ORDINARY is whether this is a normal section
895 // rather than a special code.
897 // If IS_DEFAULT_VERSION is true, then this is the definition of a
898 // default version of a symbol. That means that any lookup of
899 // NAME/NULL and any lookup of NAME/VERSION should always return the
900 // same symbol. This is obvious for references, but in particular we
901 // want to do this for definitions: overriding NAME/NULL should also
902 // override NAME/VERSION. If we don't do that, it would be very hard
903 // to override functions in a shared library which uses versioning.
905 // We implement this by simply making both entries in the hash table
906 // point to the same Symbol structure. That is easy enough if this is
907 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
908 // that we have seen both already, in which case they will both have
909 // independent entries in the symbol table. We can't simply change
910 // the symbol table entry, because we have pointers to the entries
911 // attached to the object files. So we mark the entry attached to the
912 // object file as a forwarder, and record it in the forwarders_ map.
913 // Note that entries in the hash table will never be marked as
916 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
917 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
918 // for a special section code. ST_SHNDX may be modified if the symbol
919 // is defined in a section being discarded.
921 template<int size
, bool big_endian
>
923 Symbol_table::add_from_object(Object
* object
,
925 Stringpool::Key name_key
,
927 Stringpool::Key version_key
,
928 bool is_default_version
,
929 const elfcpp::Sym
<size
, big_endian
>& sym
,
930 unsigned int st_shndx
,
932 unsigned int orig_st_shndx
)
934 // Print a message if this symbol is being traced.
935 if (parameters
->options().is_trace_symbol(name
))
937 if (orig_st_shndx
== elfcpp::SHN_UNDEF
)
938 gold_info(_("%s: reference to %s"), object
->name().c_str(), name
);
940 gold_info(_("%s: definition of %s"), object
->name().c_str(), name
);
943 // For an undefined symbol, we may need to adjust the name using
945 if (orig_st_shndx
== elfcpp::SHN_UNDEF
946 && parameters
->options().any_wrap())
948 const char* wrap_name
= this->wrap_symbol(name
, &name_key
);
949 if (wrap_name
!= name
)
951 // If we see a reference to malloc with version GLIBC_2.0,
952 // and we turn it into a reference to __wrap_malloc, then we
953 // discard the version number. Otherwise the user would be
954 // required to specify the correct version for
962 Symbol
* const snull
= NULL
;
963 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
964 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
967 std::pair
<typename
Symbol_table_type::iterator
, bool> insdefault
=
968 std::make_pair(this->table_
.end(), false);
969 if (is_default_version
)
971 const Stringpool::Key vnull_key
= 0;
972 insdefault
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
977 // ins.first: an iterator, which is a pointer to a pair.
978 // ins.first->first: the key (a pair of name and version).
979 // ins.first->second: the value (Symbol*).
980 // ins.second: true if new entry was inserted, false if not.
982 Sized_symbol
<size
>* ret
;
987 // We already have an entry for NAME/VERSION.
988 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
989 gold_assert(ret
!= NULL
);
991 was_undefined
= ret
->is_undefined();
992 // Commons from plugins are just placeholders.
993 was_common
= ret
->is_common() && ret
->object()->pluginobj() == NULL
;
995 this->resolve(ret
, sym
, st_shndx
, is_ordinary
, orig_st_shndx
, object
,
996 version
, is_default_version
);
997 if (parameters
->options().gc_sections())
998 this->gc_mark_dyn_syms(ret
);
1000 if (is_default_version
)
1001 this->define_default_version
<size
, big_endian
>(ret
, insdefault
.second
,
1007 && ret
->source() == Symbol::FROM_OBJECT
1008 && ret
->object() == object
1010 && ret
->shndx(&dummy
) == st_shndx
1011 && ret
->is_default())
1013 // We have seen NAME/VERSION already, and marked it as the
1014 // default version, but now we see a definition for
1015 // NAME/VERSION that is not the default version. This can
1016 // happen when the assembler generates two symbols for
1017 // a symbol as a result of a ".symver foo,foo@VER"
1018 // directive. We see the first unversioned symbol and
1019 // we may mark it as the default version (from a
1020 // version script); then we see the second versioned
1021 // symbol and we need to override the first.
1022 // In any other case, the two symbols should have generated
1023 // a multiple definition error.
1024 // (See PR gold/18703.)
1025 ret
->set_is_not_default();
1026 const Stringpool::Key vnull_key
= 0;
1027 this->table_
.erase(std::make_pair(name_key
, vnull_key
));
1033 // This is the first time we have seen NAME/VERSION.
1034 gold_assert(ins
.first
->second
== NULL
);
1036 if (is_default_version
&& !insdefault
.second
)
1038 // We already have an entry for NAME/NULL. If we override
1039 // it, then change it to NAME/VERSION.
1040 ret
= this->get_sized_symbol
<size
>(insdefault
.first
->second
);
1042 was_undefined
= ret
->is_undefined();
1043 // Commons from plugins are just placeholders.
1044 was_common
= ret
->is_common() && ret
->object()->pluginobj() == NULL
;
1046 this->resolve(ret
, sym
, st_shndx
, is_ordinary
, orig_st_shndx
, object
,
1047 version
, is_default_version
);
1048 if (parameters
->options().gc_sections())
1049 this->gc_mark_dyn_syms(ret
);
1050 ins
.first
->second
= ret
;
1054 was_undefined
= false;
1057 Sized_target
<size
, big_endian
>* target
=
1058 parameters
->sized_target
<size
, big_endian
>();
1059 if (!target
->has_make_symbol())
1060 ret
= new Sized_symbol
<size
>();
1063 ret
= target
->make_symbol(name
, sym
.get_st_type(), object
,
1064 st_shndx
, sym
.get_st_value());
1067 // This means that we don't want a symbol table
1069 if (!is_default_version
)
1070 this->table_
.erase(ins
.first
);
1073 this->table_
.erase(insdefault
.first
);
1074 // Inserting INSDEFAULT invalidated INS.
1075 this->table_
.erase(std::make_pair(name_key
,
1082 ret
->init_object(name
, version
, object
, sym
, st_shndx
, is_ordinary
);
1084 ins
.first
->second
= ret
;
1085 if (is_default_version
)
1087 // This is the first time we have seen NAME/NULL. Point
1088 // it at the new entry for NAME/VERSION.
1089 gold_assert(insdefault
.second
);
1090 insdefault
.first
->second
= ret
;
1094 if (is_default_version
)
1095 ret
->set_is_default();
1098 // Record every time we see a new undefined symbol, to speed up
1100 if (!was_undefined
&& ret
->is_undefined())
1102 ++this->saw_undefined_
;
1103 if (parameters
->options().has_plugins())
1104 parameters
->options().plugins()->new_undefined_symbol(ret
);
1107 // Keep track of common symbols, to speed up common symbol
1108 // allocation. Don't record commons from plugin objects;
1109 // we need to wait until we see the real symbol in the
1110 // replacement file.
1111 if (!was_common
&& ret
->is_common() && ret
->object()->pluginobj() == NULL
)
1113 if (ret
->type() == elfcpp::STT_TLS
)
1114 this->tls_commons_
.push_back(ret
);
1115 else if (!is_ordinary
1116 && st_shndx
== parameters
->target().small_common_shndx())
1117 this->small_commons_
.push_back(ret
);
1118 else if (!is_ordinary
1119 && st_shndx
== parameters
->target().large_common_shndx())
1120 this->large_commons_
.push_back(ret
);
1122 this->commons_
.push_back(ret
);
1125 // If we're not doing a relocatable link, then any symbol with
1126 // hidden or internal visibility is local.
1127 if ((ret
->visibility() == elfcpp::STV_HIDDEN
1128 || ret
->visibility() == elfcpp::STV_INTERNAL
)
1129 && (ret
->binding() == elfcpp::STB_GLOBAL
1130 || ret
->binding() == elfcpp::STB_GNU_UNIQUE
1131 || ret
->binding() == elfcpp::STB_WEAK
)
1132 && !parameters
->options().relocatable())
1133 this->force_local(ret
);
1138 // Add all the symbols in a relocatable object to the hash table.
1140 template<int size
, bool big_endian
>
1142 Symbol_table::add_from_relobj(
1143 Sized_relobj_file
<size
, big_endian
>* relobj
,
1144 const unsigned char* syms
,
1146 size_t symndx_offset
,
1147 const char* sym_names
,
1148 size_t sym_name_size
,
1149 typename Sized_relobj_file
<size
, big_endian
>::Symbols
* sympointers
,
1154 gold_assert(size
== parameters
->target().get_size());
1156 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1158 const bool just_symbols
= relobj
->just_symbols();
1160 const unsigned char* p
= syms
;
1161 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
1163 (*sympointers
)[i
] = NULL
;
1165 elfcpp::Sym
<size
, big_endian
> sym(p
);
1167 unsigned int st_name
= sym
.get_st_name();
1168 if (st_name
>= sym_name_size
)
1170 relobj
->error(_("bad global symbol name offset %u at %zu"),
1175 const char* name
= sym_names
+ st_name
;
1177 if (!parameters
->options().relocatable()
1178 && strcmp (name
, "__gnu_lto_slim") == 0)
1179 gold_info(_("%s: plugin needed to handle lto object"),
1180 relobj
->name().c_str());
1183 unsigned int st_shndx
= relobj
->adjust_sym_shndx(i
+ symndx_offset
,
1186 unsigned int orig_st_shndx
= st_shndx
;
1188 orig_st_shndx
= elfcpp::SHN_UNDEF
;
1190 if (st_shndx
!= elfcpp::SHN_UNDEF
)
1193 // A symbol defined in a section which we are not including must
1194 // be treated as an undefined symbol.
1195 bool is_defined_in_discarded_section
= false;
1196 if (st_shndx
!= elfcpp::SHN_UNDEF
1198 && !relobj
->is_section_included(st_shndx
)
1199 && !this->is_section_folded(relobj
, st_shndx
))
1201 st_shndx
= elfcpp::SHN_UNDEF
;
1202 is_defined_in_discarded_section
= true;
1205 // In an object file, an '@' in the name separates the symbol
1206 // name from the version name. If there are two '@' characters,
1207 // this is the default version.
1208 const char* ver
= strchr(name
, '@');
1209 Stringpool::Key ver_key
= 0;
1211 // IS_DEFAULT_VERSION: is the version default?
1212 // IS_FORCED_LOCAL: is the symbol forced local?
1213 bool is_default_version
= false;
1214 bool is_forced_local
= false;
1216 // FIXME: For incremental links, we don't store version information,
1217 // so we need to ignore version symbols for now.
1218 if (parameters
->incremental_update() && ver
!= NULL
)
1220 namelen
= ver
- name
;
1226 // The symbol name is of the form foo@VERSION or foo@@VERSION
1227 namelen
= ver
- name
;
1231 is_default_version
= true;
1234 ver
= this->namepool_
.add(ver
, true, &ver_key
);
1236 // We don't want to assign a version to an undefined symbol,
1237 // even if it is listed in the version script. FIXME: What
1238 // about a common symbol?
1241 namelen
= strlen(name
);
1242 if (!this->version_script_
.empty()
1243 && st_shndx
!= elfcpp::SHN_UNDEF
)
1245 // The symbol name did not have a version, but the
1246 // version script may assign a version anyway.
1247 std::string version
;
1249 if (this->version_script_
.get_symbol_version(name
, &version
,
1253 is_forced_local
= true;
1254 else if (!version
.empty())
1256 ver
= this->namepool_
.add_with_length(version
.c_str(),
1260 is_default_version
= true;
1266 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
1267 unsigned char symbuf
[sym_size
];
1268 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
1271 memcpy(symbuf
, p
, sym_size
);
1272 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1273 if (orig_st_shndx
!= elfcpp::SHN_UNDEF
1275 && relobj
->e_type() == elfcpp::ET_REL
)
1277 // Symbol values in relocatable object files are section
1278 // relative. This is normally what we want, but since here
1279 // we are converting the symbol to absolute we need to add
1280 // the section address. The section address in an object
1281 // file is normally zero, but people can use a linker
1282 // script to change it.
1283 sw
.put_st_value(sym
.get_st_value()
1284 + relobj
->section_address(orig_st_shndx
));
1286 st_shndx
= elfcpp::SHN_ABS
;
1287 is_ordinary
= false;
1291 // Fix up visibility if object has no-export set.
1292 if (relobj
->no_export()
1293 && (orig_st_shndx
!= elfcpp::SHN_UNDEF
|| !is_ordinary
))
1295 // We may have copied symbol already above.
1298 memcpy(symbuf
, p
, sym_size
);
1302 elfcpp::STV visibility
= sym2
.get_st_visibility();
1303 if (visibility
== elfcpp::STV_DEFAULT
1304 || visibility
== elfcpp::STV_PROTECTED
)
1306 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1307 unsigned char nonvis
= sym2
.get_st_nonvis();
1308 sw
.put_st_other(elfcpp::STV_HIDDEN
, nonvis
);
1312 Stringpool::Key name_key
;
1313 name
= this->namepool_
.add_with_length(name
, namelen
, true,
1316 Sized_symbol
<size
>* res
;
1317 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
1318 is_default_version
, *psym
, st_shndx
,
1319 is_ordinary
, orig_st_shndx
);
1321 if (is_forced_local
)
1322 this->force_local(res
);
1324 // Do not treat this symbol as garbage if this symbol will be
1325 // exported to the dynamic symbol table. This is true when
1326 // building a shared library or using --export-dynamic and
1327 // the symbol is externally visible.
1328 if (parameters
->options().gc_sections()
1329 && res
->is_externally_visible()
1330 && !res
->is_from_dynobj()
1331 && (parameters
->options().shared()
1332 || parameters
->options().export_dynamic()
1333 || parameters
->options().in_dynamic_list(res
->name())))
1334 this->gc_mark_symbol(res
);
1336 if (is_defined_in_discarded_section
)
1337 res
->set_is_defined_in_discarded_section();
1339 (*sympointers
)[i
] = res
;
1343 // Add a symbol from a plugin-claimed file.
1345 template<int size
, bool big_endian
>
1347 Symbol_table::add_from_pluginobj(
1348 Sized_pluginobj
<size
, big_endian
>* obj
,
1351 elfcpp::Sym
<size
, big_endian
>* sym
)
1353 unsigned int st_shndx
= sym
->get_st_shndx();
1354 bool is_ordinary
= st_shndx
< elfcpp::SHN_LORESERVE
;
1356 Stringpool::Key ver_key
= 0;
1357 bool is_default_version
= false;
1358 bool is_forced_local
= false;
1362 ver
= this->namepool_
.add(ver
, true, &ver_key
);
1364 // We don't want to assign a version to an undefined symbol,
1365 // even if it is listed in the version script. FIXME: What
1366 // about a common symbol?
1369 if (!this->version_script_
.empty()
1370 && st_shndx
!= elfcpp::SHN_UNDEF
)
1372 // The symbol name did not have a version, but the
1373 // version script may assign a version anyway.
1374 std::string version
;
1376 if (this->version_script_
.get_symbol_version(name
, &version
,
1380 is_forced_local
= true;
1381 else if (!version
.empty())
1383 ver
= this->namepool_
.add_with_length(version
.c_str(),
1387 is_default_version
= true;
1393 Stringpool::Key name_key
;
1394 name
= this->namepool_
.add(name
, true, &name_key
);
1396 Sized_symbol
<size
>* res
;
1397 res
= this->add_from_object(obj
, name
, name_key
, ver
, ver_key
,
1398 is_default_version
, *sym
, st_shndx
,
1399 is_ordinary
, st_shndx
);
1401 if (is_forced_local
)
1402 this->force_local(res
);
1407 // Add all the symbols in a dynamic object to the hash table.
1409 template<int size
, bool big_endian
>
1411 Symbol_table::add_from_dynobj(
1412 Sized_dynobj
<size
, big_endian
>* dynobj
,
1413 const unsigned char* syms
,
1415 const char* sym_names
,
1416 size_t sym_name_size
,
1417 const unsigned char* versym
,
1419 const std::vector
<const char*>* version_map
,
1420 typename Sized_relobj_file
<size
, big_endian
>::Symbols
* sympointers
,
1425 gold_assert(size
== parameters
->target().get_size());
1427 if (dynobj
->just_symbols())
1429 gold_error(_("--just-symbols does not make sense with a shared object"));
1433 // FIXME: For incremental links, we don't store version information,
1434 // so we need to ignore version symbols for now.
1435 if (parameters
->incremental_update())
1438 if (versym
!= NULL
&& versym_size
/ 2 < count
)
1440 dynobj
->error(_("too few symbol versions"));
1444 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1446 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1447 // weak aliases. This is necessary because if the dynamic object
1448 // provides the same variable under two names, one of which is a
1449 // weak definition, and the regular object refers to the weak
1450 // definition, we have to put both the weak definition and the
1451 // strong definition into the dynamic symbol table. Given a weak
1452 // definition, the only way that we can find the corresponding
1453 // strong definition, if any, is to search the symbol table.
1454 std::vector
<Sized_symbol
<size
>*> object_symbols
;
1456 const unsigned char* p
= syms
;
1457 const unsigned char* vs
= versym
;
1458 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
1460 elfcpp::Sym
<size
, big_endian
> sym(p
);
1462 if (sympointers
!= NULL
)
1463 (*sympointers
)[i
] = NULL
;
1465 // Ignore symbols with local binding or that have
1466 // internal or hidden visibility.
1467 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
1468 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
1469 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
1472 // A protected symbol in a shared library must be treated as a
1473 // normal symbol when viewed from outside the shared library.
1474 // Implement this by overriding the visibility here.
1475 // Likewise, an IFUNC symbol in a shared library must be treated
1476 // as a normal FUNC symbol.
1477 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
1478 unsigned char symbuf
[sym_size
];
1479 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
1480 if (sym
.get_st_visibility() == elfcpp::STV_PROTECTED
1481 || sym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1483 memcpy(symbuf
, p
, sym_size
);
1484 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1485 if (sym
.get_st_visibility() == elfcpp::STV_PROTECTED
)
1486 sw
.put_st_other(elfcpp::STV_DEFAULT
, sym
.get_st_nonvis());
1487 if (sym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1488 sw
.put_st_info(sym
.get_st_bind(), elfcpp::STT_FUNC
);
1492 unsigned int st_name
= psym
->get_st_name();
1493 if (st_name
>= sym_name_size
)
1495 dynobj
->error(_("bad symbol name offset %u at %zu"),
1500 const char* name
= sym_names
+ st_name
;
1503 unsigned int st_shndx
= dynobj
->adjust_sym_shndx(i
, psym
->get_st_shndx(),
1506 if (st_shndx
!= elfcpp::SHN_UNDEF
)
1509 Sized_symbol
<size
>* res
;
1513 Stringpool::Key name_key
;
1514 name
= this->namepool_
.add(name
, true, &name_key
);
1515 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1516 false, *psym
, st_shndx
, is_ordinary
,
1521 // Read the version information.
1523 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
1525 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
1526 v
&= elfcpp::VERSYM_VERSION
;
1528 // The Sun documentation says that V can be VER_NDX_LOCAL,
1529 // or VER_NDX_GLOBAL, or a version index. The meaning of
1530 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1531 // The old GNU linker will happily generate VER_NDX_LOCAL
1532 // for an undefined symbol. I don't know what the Sun
1533 // linker will generate.
1535 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
1536 && st_shndx
!= elfcpp::SHN_UNDEF
)
1538 // This symbol should not be visible outside the object.
1542 // At this point we are definitely going to add this symbol.
1543 Stringpool::Key name_key
;
1544 name
= this->namepool_
.add(name
, true, &name_key
);
1546 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
1547 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
1549 // This symbol does not have a version.
1550 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1551 false, *psym
, st_shndx
, is_ordinary
,
1556 if (v
>= version_map
->size())
1558 dynobj
->error(_("versym for symbol %zu out of range: %u"),
1563 const char* version
= (*version_map
)[v
];
1564 if (version
== NULL
)
1566 dynobj
->error(_("versym for symbol %zu has no name: %u"),
1571 Stringpool::Key version_key
;
1572 version
= this->namepool_
.add(version
, true, &version_key
);
1574 // If this is an absolute symbol, and the version name
1575 // and symbol name are the same, then this is the
1576 // version definition symbol. These symbols exist to
1577 // support using -u to pull in particular versions. We
1578 // do not want to record a version for them.
1579 if (st_shndx
== elfcpp::SHN_ABS
1581 && name_key
== version_key
)
1582 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1583 false, *psym
, st_shndx
, is_ordinary
,
1587 const bool is_default_version
=
1588 !hidden
&& st_shndx
!= elfcpp::SHN_UNDEF
;
1589 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
1590 version_key
, is_default_version
,
1592 is_ordinary
, st_shndx
);
1597 // Note that it is possible that RES was overridden by an
1598 // earlier object, in which case it can't be aliased here.
1599 if (st_shndx
!= elfcpp::SHN_UNDEF
1601 && psym
->get_st_type() == elfcpp::STT_OBJECT
1602 && res
->source() == Symbol::FROM_OBJECT
1603 && res
->object() == dynobj
)
1604 object_symbols
.push_back(res
);
1606 if (sympointers
!= NULL
)
1607 (*sympointers
)[i
] = res
;
1610 this->record_weak_aliases(&object_symbols
);
1613 // Add a symbol from a incremental object file.
1615 template<int size
, bool big_endian
>
1617 Symbol_table::add_from_incrobj(
1621 elfcpp::Sym
<size
, big_endian
>* sym
)
1623 unsigned int st_shndx
= sym
->get_st_shndx();
1624 bool is_ordinary
= st_shndx
< elfcpp::SHN_LORESERVE
;
1626 Stringpool::Key ver_key
= 0;
1627 bool is_default_version
= false;
1628 bool is_forced_local
= false;
1630 Stringpool::Key name_key
;
1631 name
= this->namepool_
.add(name
, true, &name_key
);
1633 Sized_symbol
<size
>* res
;
1634 res
= this->add_from_object(obj
, name
, name_key
, ver
, ver_key
,
1635 is_default_version
, *sym
, st_shndx
,
1636 is_ordinary
, st_shndx
);
1638 if (is_forced_local
)
1639 this->force_local(res
);
1644 // This is used to sort weak aliases. We sort them first by section
1645 // index, then by offset, then by weak ahead of strong.
1648 class Weak_alias_sorter
1651 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
1656 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
1657 const Sized_symbol
<size
>* s2
) const
1660 unsigned int s1_shndx
= s1
->shndx(&is_ordinary
);
1661 gold_assert(is_ordinary
);
1662 unsigned int s2_shndx
= s2
->shndx(&is_ordinary
);
1663 gold_assert(is_ordinary
);
1664 if (s1_shndx
!= s2_shndx
)
1665 return s1_shndx
< s2_shndx
;
1667 if (s1
->value() != s2
->value())
1668 return s1
->value() < s2
->value();
1669 if (s1
->binding() != s2
->binding())
1671 if (s1
->binding() == elfcpp::STB_WEAK
)
1673 if (s2
->binding() == elfcpp::STB_WEAK
)
1676 return std::string(s1
->name()) < std::string(s2
->name());
1679 // SYMBOLS is a list of object symbols from a dynamic object. Look
1680 // for any weak aliases, and record them so that if we add the weak
1681 // alias to the dynamic symbol table, we also add the corresponding
1686 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
1688 // Sort the vector by section index, then by offset, then by weak
1690 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
1692 // Walk through the vector. For each weak definition, record
1694 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
1696 p
!= symbols
->end();
1699 if ((*p
)->binding() != elfcpp::STB_WEAK
)
1702 // Build a circular list of weak aliases. Each symbol points to
1703 // the next one in the circular list.
1705 Sized_symbol
<size
>* from_sym
= *p
;
1706 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
1707 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
1710 if ((*q
)->shndx(&dummy
) != from_sym
->shndx(&dummy
)
1711 || (*q
)->value() != from_sym
->value())
1714 this->weak_aliases_
[from_sym
] = *q
;
1715 from_sym
->set_has_alias();
1721 this->weak_aliases_
[from_sym
] = *p
;
1722 from_sym
->set_has_alias();
1729 // Create and return a specially defined symbol. If ONLY_IF_REF is
1730 // true, then only create the symbol if there is a reference to it.
1731 // If this does not return NULL, it sets *POLDSYM to the existing
1732 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1733 // resolve the newly created symbol to the old one. This
1734 // canonicalizes *PNAME and *PVERSION.
1736 template<int size
, bool big_endian
>
1738 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1740 Sized_symbol
<size
>** poldsym
,
1741 bool* resolve_oldsym
)
1743 *resolve_oldsym
= false;
1746 // If the caller didn't give us a version, see if we get one from
1747 // the version script.
1749 bool is_default_version
= false;
1750 if (*pversion
== NULL
)
1753 if (this->version_script_
.get_symbol_version(*pname
, &v
, &is_global
))
1755 if (is_global
&& !v
.empty())
1757 *pversion
= v
.c_str();
1758 // If we get the version from a version script, then we
1759 // are also the default version.
1760 is_default_version
= true;
1766 Sized_symbol
<size
>* sym
;
1768 bool add_to_table
= false;
1769 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1770 bool add_def_to_table
= false;
1771 typename
Symbol_table_type::iterator add_def_loc
= this->table_
.end();
1775 oldsym
= this->lookup(*pname
, *pversion
);
1776 if (oldsym
== NULL
&& is_default_version
)
1777 oldsym
= this->lookup(*pname
, NULL
);
1778 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1781 *pname
= oldsym
->name();
1782 if (is_default_version
)
1783 *pversion
= this->namepool_
.add(*pversion
, true, NULL
);
1785 *pversion
= oldsym
->version();
1789 // Canonicalize NAME and VERSION.
1790 Stringpool::Key name_key
;
1791 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1793 Stringpool::Key version_key
= 0;
1794 if (*pversion
!= NULL
)
1795 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1797 Symbol
* const snull
= NULL
;
1798 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1799 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1803 std::pair
<typename
Symbol_table_type::iterator
, bool> insdefault
=
1804 std::make_pair(this->table_
.end(), false);
1805 if (is_default_version
)
1807 const Stringpool::Key vnull
= 0;
1809 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1816 // We already have a symbol table entry for NAME/VERSION.
1817 oldsym
= ins
.first
->second
;
1818 gold_assert(oldsym
!= NULL
);
1820 if (is_default_version
)
1822 Sized_symbol
<size
>* soldsym
=
1823 this->get_sized_symbol
<size
>(oldsym
);
1824 this->define_default_version
<size
, big_endian
>(soldsym
,
1831 // We haven't seen this symbol before.
1832 gold_assert(ins
.first
->second
== NULL
);
1834 add_to_table
= true;
1835 add_loc
= ins
.first
;
1837 if (is_default_version
&& !insdefault
.second
)
1839 // We are adding NAME/VERSION, and it is the default
1840 // version. We already have an entry for NAME/NULL.
1841 oldsym
= insdefault
.first
->second
;
1842 *resolve_oldsym
= true;
1848 if (is_default_version
)
1850 add_def_to_table
= true;
1851 add_def_loc
= insdefault
.first
;
1857 const Target
& target
= parameters
->target();
1858 if (!target
.has_make_symbol())
1859 sym
= new Sized_symbol
<size
>();
1862 Sized_target
<size
, big_endian
>* sized_target
=
1863 parameters
->sized_target
<size
, big_endian
>();
1864 sym
= sized_target
->make_symbol(*pname
, elfcpp::STT_NOTYPE
,
1865 NULL
, elfcpp::SHN_UNDEF
, 0);
1871 add_loc
->second
= sym
;
1873 gold_assert(oldsym
!= NULL
);
1875 if (add_def_to_table
)
1876 add_def_loc
->second
= sym
;
1878 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1883 // Define a symbol based on an Output_data.
1886 Symbol_table::define_in_output_data(const char* name
,
1887 const char* version
,
1893 elfcpp::STB binding
,
1894 elfcpp::STV visibility
,
1895 unsigned char nonvis
,
1896 bool offset_is_from_end
,
1899 if (parameters
->target().get_size() == 32)
1901 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1902 return this->do_define_in_output_data
<32>(name
, version
, defined
, od
,
1903 value
, symsize
, type
, binding
,
1911 else if (parameters
->target().get_size() == 64)
1913 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1914 return this->do_define_in_output_data
<64>(name
, version
, defined
, od
,
1915 value
, symsize
, type
, binding
,
1927 // Define a symbol in an Output_data, sized version.
1931 Symbol_table::do_define_in_output_data(
1933 const char* version
,
1936 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1937 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1939 elfcpp::STB binding
,
1940 elfcpp::STV visibility
,
1941 unsigned char nonvis
,
1942 bool offset_is_from_end
,
1945 Sized_symbol
<size
>* sym
;
1946 Sized_symbol
<size
>* oldsym
;
1947 bool resolve_oldsym
;
1949 if (parameters
->target().is_big_endian())
1951 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1952 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1953 only_if_ref
, &oldsym
,
1961 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1962 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1963 only_if_ref
, &oldsym
,
1973 sym
->init_output_data(name
, version
, od
, value
, symsize
, type
, binding
,
1974 visibility
, nonvis
, offset_is_from_end
,
1975 defined
== PREDEFINED
);
1979 if (binding
== elfcpp::STB_LOCAL
1980 || this->version_script_
.symbol_is_local(name
))
1981 this->force_local(sym
);
1982 else if (version
!= NULL
)
1983 sym
->set_is_default();
1987 if (Symbol_table::should_override_with_special(oldsym
, type
, defined
))
1988 this->override_with_special(oldsym
, sym
);
1994 if (defined
== PREDEFINED
1995 && (binding
== elfcpp::STB_LOCAL
1996 || this->version_script_
.symbol_is_local(name
)))
1997 this->force_local(oldsym
);
2003 // Define a symbol based on an Output_segment.
2006 Symbol_table::define_in_output_segment(const char* name
,
2007 const char* version
,
2013 elfcpp::STB binding
,
2014 elfcpp::STV visibility
,
2015 unsigned char nonvis
,
2016 Symbol::Segment_offset_base offset_base
,
2019 if (parameters
->target().get_size() == 32)
2021 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2022 return this->do_define_in_output_segment
<32>(name
, version
, defined
, os
,
2023 value
, symsize
, type
,
2024 binding
, visibility
, nonvis
,
2025 offset_base
, only_if_ref
);
2030 else if (parameters
->target().get_size() == 64)
2032 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2033 return this->do_define_in_output_segment
<64>(name
, version
, defined
, os
,
2034 value
, symsize
, type
,
2035 binding
, visibility
, nonvis
,
2036 offset_base
, only_if_ref
);
2045 // Define a symbol in an Output_segment, sized version.
2049 Symbol_table::do_define_in_output_segment(
2051 const char* version
,
2054 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
2055 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
2057 elfcpp::STB binding
,
2058 elfcpp::STV visibility
,
2059 unsigned char nonvis
,
2060 Symbol::Segment_offset_base offset_base
,
2063 Sized_symbol
<size
>* sym
;
2064 Sized_symbol
<size
>* oldsym
;
2065 bool resolve_oldsym
;
2067 if (parameters
->target().is_big_endian())
2069 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2070 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
2071 only_if_ref
, &oldsym
,
2079 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2080 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
2081 only_if_ref
, &oldsym
,
2091 sym
->init_output_segment(name
, version
, os
, value
, symsize
, type
, binding
,
2092 visibility
, nonvis
, offset_base
,
2093 defined
== PREDEFINED
);
2097 if (binding
== elfcpp::STB_LOCAL
2098 || this->version_script_
.symbol_is_local(name
))
2099 this->force_local(sym
);
2100 else if (version
!= NULL
)
2101 sym
->set_is_default();
2105 if (Symbol_table::should_override_with_special(oldsym
, type
, defined
))
2106 this->override_with_special(oldsym
, sym
);
2112 if (binding
== elfcpp::STB_LOCAL
2113 || this->version_script_
.symbol_is_local(name
))
2114 this->force_local(oldsym
);
2120 // Define a special symbol with a constant value. It is a multiple
2121 // definition error if this symbol is already defined.
2124 Symbol_table::define_as_constant(const char* name
,
2125 const char* version
,
2130 elfcpp::STB binding
,
2131 elfcpp::STV visibility
,
2132 unsigned char nonvis
,
2134 bool force_override
)
2136 if (parameters
->target().get_size() == 32)
2138 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2139 return this->do_define_as_constant
<32>(name
, version
, defined
, value
,
2140 symsize
, type
, binding
,
2141 visibility
, nonvis
, only_if_ref
,
2147 else if (parameters
->target().get_size() == 64)
2149 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2150 return this->do_define_as_constant
<64>(name
, version
, defined
, value
,
2151 symsize
, type
, binding
,
2152 visibility
, nonvis
, only_if_ref
,
2162 // Define a symbol as a constant, sized version.
2166 Symbol_table::do_define_as_constant(
2168 const char* version
,
2170 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
2171 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
2173 elfcpp::STB binding
,
2174 elfcpp::STV visibility
,
2175 unsigned char nonvis
,
2177 bool force_override
)
2179 Sized_symbol
<size
>* sym
;
2180 Sized_symbol
<size
>* oldsym
;
2181 bool resolve_oldsym
;
2183 if (parameters
->target().is_big_endian())
2185 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2186 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
2187 only_if_ref
, &oldsym
,
2195 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2196 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
2197 only_if_ref
, &oldsym
,
2207 sym
->init_constant(name
, version
, value
, symsize
, type
, binding
, visibility
,
2208 nonvis
, defined
== PREDEFINED
);
2212 // Version symbols are absolute symbols with name == version.
2213 // We don't want to force them to be local.
2214 if ((version
== NULL
2217 && (binding
== elfcpp::STB_LOCAL
2218 || this->version_script_
.symbol_is_local(name
)))
2219 this->force_local(sym
);
2220 else if (version
!= NULL
2221 && (name
!= version
|| value
!= 0))
2222 sym
->set_is_default();
2227 || Symbol_table::should_override_with_special(oldsym
, type
, defined
))
2228 this->override_with_special(oldsym
, sym
);
2234 if (binding
== elfcpp::STB_LOCAL
2235 || this->version_script_
.symbol_is_local(name
))
2236 this->force_local(oldsym
);
2242 // Define a set of symbols in output sections.
2245 Symbol_table::define_symbols(const Layout
* layout
, int count
,
2246 const Define_symbol_in_section
* p
,
2249 for (int i
= 0; i
< count
; ++i
, ++p
)
2251 Output_section
* os
= layout
->find_output_section(p
->output_section
);
2253 this->define_in_output_data(p
->name
, NULL
, PREDEFINED
, os
, p
->value
,
2254 p
->size
, p
->type
, p
->binding
,
2255 p
->visibility
, p
->nonvis
,
2256 p
->offset_is_from_end
,
2257 only_if_ref
|| p
->only_if_ref
);
2259 this->define_as_constant(p
->name
, NULL
, PREDEFINED
, 0, p
->size
,
2260 p
->type
, p
->binding
, p
->visibility
, p
->nonvis
,
2261 only_if_ref
|| p
->only_if_ref
,
2266 // Define a set of symbols in output segments.
2269 Symbol_table::define_symbols(const Layout
* layout
, int count
,
2270 const Define_symbol_in_segment
* p
,
2273 for (int i
= 0; i
< count
; ++i
, ++p
)
2275 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
2276 p
->segment_flags_set
,
2277 p
->segment_flags_clear
);
2279 this->define_in_output_segment(p
->name
, NULL
, PREDEFINED
, os
, p
->value
,
2280 p
->size
, p
->type
, p
->binding
,
2281 p
->visibility
, p
->nonvis
,
2283 only_if_ref
|| p
->only_if_ref
);
2285 this->define_as_constant(p
->name
, NULL
, PREDEFINED
, 0, p
->size
,
2286 p
->type
, p
->binding
, p
->visibility
, p
->nonvis
,
2287 only_if_ref
|| p
->only_if_ref
,
2292 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2293 // symbol should be defined--typically a .dyn.bss section. VALUE is
2294 // the offset within POSD.
2298 Symbol_table::define_with_copy_reloc(
2299 Sized_symbol
<size
>* csym
,
2301 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
2303 gold_assert(csym
->is_from_dynobj());
2304 gold_assert(!csym
->is_copied_from_dynobj());
2305 Object
* object
= csym
->object();
2306 gold_assert(object
->is_dynamic());
2307 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
2309 // Our copied variable has to override any variable in a shared
2311 elfcpp::STB binding
= csym
->binding();
2312 if (binding
== elfcpp::STB_WEAK
)
2313 binding
= elfcpp::STB_GLOBAL
;
2315 this->define_in_output_data(csym
->name(), csym
->version(), COPY
,
2316 posd
, value
, csym
->symsize(),
2317 csym
->type(), binding
,
2318 csym
->visibility(), csym
->nonvis(),
2321 csym
->set_is_copied_from_dynobj();
2322 csym
->set_needs_dynsym_entry();
2324 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
2326 // We have now defined all aliases, but we have not entered them all
2327 // in the copied_symbol_dynobjs_ map.
2328 if (csym
->has_alias())
2333 sym
= this->weak_aliases_
[sym
];
2336 gold_assert(sym
->output_data() == posd
);
2338 sym
->set_is_copied_from_dynobj();
2339 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
2344 // SYM is defined using a COPY reloc. Return the dynamic object where
2345 // the original definition was found.
2348 Symbol_table::get_copy_source(const Symbol
* sym
) const
2350 gold_assert(sym
->is_copied_from_dynobj());
2351 Copied_symbol_dynobjs::const_iterator p
=
2352 this->copied_symbol_dynobjs_
.find(sym
);
2353 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
2357 // Add any undefined symbols named on the command line.
2360 Symbol_table::add_undefined_symbols_from_command_line(Layout
* layout
)
2362 if (parameters
->options().any_undefined()
2363 || layout
->script_options()->any_unreferenced())
2365 if (parameters
->target().get_size() == 32)
2367 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2368 this->do_add_undefined_symbols_from_command_line
<32>(layout
);
2373 else if (parameters
->target().get_size() == 64)
2375 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2376 this->do_add_undefined_symbols_from_command_line
<64>(layout
);
2388 Symbol_table::do_add_undefined_symbols_from_command_line(Layout
* layout
)
2390 for (options::String_set::const_iterator p
=
2391 parameters
->options().undefined_begin();
2392 p
!= parameters
->options().undefined_end();
2394 this->add_undefined_symbol_from_command_line
<size
>(p
->c_str());
2396 for (options::String_set::const_iterator p
=
2397 parameters
->options().export_dynamic_symbol_begin();
2398 p
!= parameters
->options().export_dynamic_symbol_end();
2400 this->add_undefined_symbol_from_command_line
<size
>(p
->c_str());
2402 for (Script_options::referenced_const_iterator p
=
2403 layout
->script_options()->referenced_begin();
2404 p
!= layout
->script_options()->referenced_end();
2406 this->add_undefined_symbol_from_command_line
<size
>(p
->c_str());
2411 Symbol_table::add_undefined_symbol_from_command_line(const char* name
)
2413 if (this->lookup(name
) != NULL
)
2416 const char* version
= NULL
;
2418 Sized_symbol
<size
>* sym
;
2419 Sized_symbol
<size
>* oldsym
;
2420 bool resolve_oldsym
;
2421 if (parameters
->target().is_big_endian())
2423 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2424 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
2433 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2434 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
2442 gold_assert(oldsym
== NULL
);
2444 sym
->init_undefined(name
, version
, 0, elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
2445 elfcpp::STV_DEFAULT
, 0);
2446 ++this->saw_undefined_
;
2449 // Set the dynamic symbol indexes. INDEX is the index of the first
2450 // global dynamic symbol. Pointers to the symbols are stored into the
2451 // vector SYMS. The names are added to DYNPOOL. This returns an
2452 // updated dynamic symbol index.
2455 Symbol_table::set_dynsym_indexes(unsigned int index
,
2456 std::vector
<Symbol
*>* syms
,
2457 Stringpool
* dynpool
,
2460 std::vector
<Symbol
*> as_needed_sym
;
2462 // Allow a target to set dynsym indexes.
2463 if (parameters
->target().has_custom_set_dynsym_indexes())
2465 std::vector
<Symbol
*> dyn_symbols
;
2466 for (Symbol_table_type::iterator p
= this->table_
.begin();
2467 p
!= this->table_
.end();
2470 Symbol
* sym
= p
->second
;
2471 if (!sym
->should_add_dynsym_entry(this))
2472 sym
->set_dynsym_index(-1U);
2474 dyn_symbols
.push_back(sym
);
2477 return parameters
->target().set_dynsym_indexes(&dyn_symbols
, index
, syms
,
2478 dynpool
, versions
, this);
2481 for (Symbol_table_type::iterator p
= this->table_
.begin();
2482 p
!= this->table_
.end();
2485 Symbol
* sym
= p
->second
;
2487 // Note that SYM may already have a dynamic symbol index, since
2488 // some symbols appear more than once in the symbol table, with
2489 // and without a version.
2491 if (!sym
->should_add_dynsym_entry(this))
2492 sym
->set_dynsym_index(-1U);
2493 else if (!sym
->has_dynsym_index())
2495 sym
->set_dynsym_index(index
);
2497 syms
->push_back(sym
);
2498 dynpool
->add(sym
->name(), false, NULL
);
2500 // If the symbol is defined in a dynamic object and is
2501 // referenced strongly in a regular object, then mark the
2502 // dynamic object as needed. This is used to implement
2504 if (sym
->is_from_dynobj()
2506 && !sym
->is_undef_binding_weak())
2507 sym
->object()->set_is_needed();
2509 // Record any version information, except those from
2510 // as-needed libraries not seen to be needed. Note that the
2511 // is_needed state for such libraries can change in this loop.
2512 if (sym
->version() != NULL
)
2514 if (!sym
->is_from_dynobj()
2515 || !sym
->object()->as_needed()
2516 || sym
->object()->is_needed())
2517 versions
->record_version(this, dynpool
, sym
);
2519 as_needed_sym
.push_back(sym
);
2524 // Process version information for symbols from as-needed libraries.
2525 for (std::vector
<Symbol
*>::iterator p
= as_needed_sym
.begin();
2526 p
!= as_needed_sym
.end();
2531 if (sym
->object()->is_needed())
2532 versions
->record_version(this, dynpool
, sym
);
2534 sym
->clear_version();
2537 // Finish up the versions. In some cases this may add new dynamic
2539 index
= versions
->finalize(this, index
, syms
);
2541 // Process target-specific symbols.
2542 for (std::vector
<Symbol
*>::iterator p
= this->target_symbols_
.begin();
2543 p
!= this->target_symbols_
.end();
2546 (*p
)->set_dynsym_index(index
);
2548 syms
->push_back(*p
);
2549 dynpool
->add((*p
)->name(), false, NULL
);
2555 // Set the final values for all the symbols. The index of the first
2556 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2557 // file offset OFF. Add their names to POOL. Return the new file
2558 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2561 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
2562 size_t dyncount
, Stringpool
* pool
,
2563 unsigned int* plocal_symcount
)
2567 gold_assert(*plocal_symcount
!= 0);
2568 this->first_global_index_
= *plocal_symcount
;
2570 this->dynamic_offset_
= dynoff
;
2571 this->first_dynamic_global_index_
= dyn_global_index
;
2572 this->dynamic_count_
= dyncount
;
2574 if (parameters
->target().get_size() == 32)
2576 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2577 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
2582 else if (parameters
->target().get_size() == 64)
2584 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2585 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
2593 // Now that we have the final symbol table, we can reliably note
2594 // which symbols should get warnings.
2595 this->warnings_
.note_warnings(this);
2600 // SYM is going into the symbol table at *PINDEX. Add the name to
2601 // POOL, update *PINDEX and *POFF.
2605 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
2606 unsigned int* pindex
, off_t
* poff
)
2608 sym
->set_symtab_index(*pindex
);
2609 if (sym
->version() == NULL
|| !parameters
->options().relocatable())
2610 pool
->add(sym
->name(), false, NULL
);
2612 pool
->add(sym
->versioned_name(), true, NULL
);
2614 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
2617 // Set the final value for all the symbols. This is called after
2618 // Layout::finalize, so all the output sections have their final
2623 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
2624 unsigned int* plocal_symcount
)
2626 off
= align_address(off
, size
>> 3);
2627 this->offset_
= off
;
2629 unsigned int index
= *plocal_symcount
;
2630 const unsigned int orig_index
= index
;
2632 // First do all the symbols which have been forced to be local, as
2633 // they must appear before all global symbols.
2634 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
2635 p
!= this->forced_locals_
.end();
2639 gold_assert(sym
->is_forced_local());
2640 if (this->sized_finalize_symbol
<size
>(sym
))
2642 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
2647 // Now do all the remaining symbols.
2648 for (Symbol_table_type::iterator p
= this->table_
.begin();
2649 p
!= this->table_
.end();
2652 Symbol
* sym
= p
->second
;
2653 if (this->sized_finalize_symbol
<size
>(sym
))
2654 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
2657 // Now do target-specific symbols.
2658 for (std::vector
<Symbol
*>::iterator p
= this->target_symbols_
.begin();
2659 p
!= this->target_symbols_
.end();
2662 this->add_to_final_symtab
<size
>(*p
, pool
, &index
, &off
);
2665 this->output_count_
= index
- orig_index
;
2670 // Compute the final value of SYM and store status in location PSTATUS.
2671 // During relaxation, this may be called multiple times for a symbol to
2672 // compute its would-be final value in each relaxation pass.
2675 typename Sized_symbol
<size
>::Value_type
2676 Symbol_table::compute_final_value(
2677 const Sized_symbol
<size
>* sym
,
2678 Compute_final_value_status
* pstatus
) const
2680 typedef typename Sized_symbol
<size
>::Value_type Value_type
;
2683 switch (sym
->source())
2685 case Symbol::FROM_OBJECT
:
2688 unsigned int shndx
= sym
->shndx(&is_ordinary
);
2691 && shndx
!= elfcpp::SHN_ABS
2692 && !Symbol::is_common_shndx(shndx
))
2694 *pstatus
= CFVS_UNSUPPORTED_SYMBOL_SECTION
;
2698 Object
* symobj
= sym
->object();
2699 if (symobj
->is_dynamic())
2702 shndx
= elfcpp::SHN_UNDEF
;
2704 else if (symobj
->pluginobj() != NULL
)
2707 shndx
= elfcpp::SHN_UNDEF
;
2709 else if (shndx
== elfcpp::SHN_UNDEF
)
2711 else if (!is_ordinary
2712 && (shndx
== elfcpp::SHN_ABS
2713 || Symbol::is_common_shndx(shndx
)))
2714 value
= sym
->value();
2717 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
2718 Output_section
* os
= relobj
->output_section(shndx
);
2720 if (this->is_section_folded(relobj
, shndx
))
2722 gold_assert(os
== NULL
);
2723 // Get the os of the section it is folded onto.
2724 Section_id folded
= this->icf_
->get_folded_section(relobj
,
2726 gold_assert(folded
.first
!= NULL
);
2727 Relobj
* folded_obj
= reinterpret_cast<Relobj
*>(folded
.first
);
2728 unsigned folded_shndx
= folded
.second
;
2730 os
= folded_obj
->output_section(folded_shndx
);
2731 gold_assert(os
!= NULL
);
2733 // Replace (relobj, shndx) with canonical ICF input section.
2734 shndx
= folded_shndx
;
2735 relobj
= folded_obj
;
2738 uint64_t secoff64
= relobj
->output_section_offset(shndx
);
2741 bool static_or_reloc
= (parameters
->doing_static_link() ||
2742 parameters
->options().relocatable());
2743 gold_assert(static_or_reloc
|| sym
->dynsym_index() == -1U);
2745 *pstatus
= CFVS_NO_OUTPUT_SECTION
;
2749 if (secoff64
== -1ULL)
2751 // The section needs special handling (e.g., a merge section).
2753 value
= os
->output_address(relobj
, shndx
, sym
->value());
2758 convert_types
<Value_type
, uint64_t>(secoff64
);
2759 if (sym
->type() == elfcpp::STT_TLS
)
2760 value
= sym
->value() + os
->tls_offset() + secoff
;
2762 value
= sym
->value() + os
->address() + secoff
;
2768 case Symbol::IN_OUTPUT_DATA
:
2770 Output_data
* od
= sym
->output_data();
2771 value
= sym
->value();
2772 if (sym
->type() != elfcpp::STT_TLS
)
2773 value
+= od
->address();
2776 Output_section
* os
= od
->output_section();
2777 gold_assert(os
!= NULL
);
2778 value
+= os
->tls_offset() + (od
->address() - os
->address());
2780 if (sym
->offset_is_from_end())
2781 value
+= od
->data_size();
2785 case Symbol::IN_OUTPUT_SEGMENT
:
2787 Output_segment
* os
= sym
->output_segment();
2788 value
= sym
->value();
2789 if (sym
->type() != elfcpp::STT_TLS
)
2790 value
+= os
->vaddr();
2791 switch (sym
->offset_base())
2793 case Symbol::SEGMENT_START
:
2795 case Symbol::SEGMENT_END
:
2796 value
+= os
->memsz();
2798 case Symbol::SEGMENT_BSS
:
2799 value
+= os
->filesz();
2807 case Symbol::IS_CONSTANT
:
2808 value
= sym
->value();
2811 case Symbol::IS_UNDEFINED
:
2823 // Finalize the symbol SYM. This returns true if the symbol should be
2824 // added to the symbol table, false otherwise.
2828 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
2830 typedef typename Sized_symbol
<size
>::Value_type Value_type
;
2832 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
2834 // The default version of a symbol may appear twice in the symbol
2835 // table. We only need to finalize it once.
2836 if (sym
->has_symtab_index())
2841 gold_assert(!sym
->has_symtab_index());
2842 sym
->set_symtab_index(-1U);
2843 gold_assert(sym
->dynsym_index() == -1U);
2847 // If the symbol is only present on plugin files, the plugin decided we
2849 if (!sym
->in_real_elf())
2851 gold_assert(!sym
->has_symtab_index());
2852 sym
->set_symtab_index(-1U);
2856 // Compute final symbol value.
2857 Compute_final_value_status status
;
2858 Value_type value
= this->compute_final_value(sym
, &status
);
2864 case CFVS_UNSUPPORTED_SYMBOL_SECTION
:
2867 unsigned int shndx
= sym
->shndx(&is_ordinary
);
2868 gold_error(_("%s: unsupported symbol section 0x%x"),
2869 sym
->demangled_name().c_str(), shndx
);
2872 case CFVS_NO_OUTPUT_SECTION
:
2873 sym
->set_symtab_index(-1U);
2879 sym
->set_value(value
);
2881 if (parameters
->options().strip_all()
2882 || !parameters
->options().should_retain_symbol(sym
->name()))
2884 sym
->set_symtab_index(-1U);
2891 // Write out the global symbols.
2894 Symbol_table::write_globals(const Stringpool
* sympool
,
2895 const Stringpool
* dynpool
,
2896 Output_symtab_xindex
* symtab_xindex
,
2897 Output_symtab_xindex
* dynsym_xindex
,
2898 Output_file
* of
) const
2900 switch (parameters
->size_and_endianness())
2902 #ifdef HAVE_TARGET_32_LITTLE
2903 case Parameters::TARGET_32_LITTLE
:
2904 this->sized_write_globals
<32, false>(sympool
, dynpool
, symtab_xindex
,
2908 #ifdef HAVE_TARGET_32_BIG
2909 case Parameters::TARGET_32_BIG
:
2910 this->sized_write_globals
<32, true>(sympool
, dynpool
, symtab_xindex
,
2914 #ifdef HAVE_TARGET_64_LITTLE
2915 case Parameters::TARGET_64_LITTLE
:
2916 this->sized_write_globals
<64, false>(sympool
, dynpool
, symtab_xindex
,
2920 #ifdef HAVE_TARGET_64_BIG
2921 case Parameters::TARGET_64_BIG
:
2922 this->sized_write_globals
<64, true>(sympool
, dynpool
, symtab_xindex
,
2931 // Write out the global symbols.
2933 template<int size
, bool big_endian
>
2935 Symbol_table::sized_write_globals(const Stringpool
* sympool
,
2936 const Stringpool
* dynpool
,
2937 Output_symtab_xindex
* symtab_xindex
,
2938 Output_symtab_xindex
* dynsym_xindex
,
2939 Output_file
* of
) const
2941 const Target
& target
= parameters
->target();
2943 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2945 const unsigned int output_count
= this->output_count_
;
2946 const section_size_type oview_size
= output_count
* sym_size
;
2947 const unsigned int first_global_index
= this->first_global_index_
;
2948 unsigned char* psyms
;
2949 if (this->offset_
== 0 || output_count
== 0)
2952 psyms
= of
->get_output_view(this->offset_
, oview_size
);
2954 const unsigned int dynamic_count
= this->dynamic_count_
;
2955 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
2956 const unsigned int first_dynamic_global_index
=
2957 this->first_dynamic_global_index_
;
2958 unsigned char* dynamic_view
;
2959 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
2960 dynamic_view
= NULL
;
2962 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
2964 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
2965 p
!= this->table_
.end();
2968 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
2970 // Possibly warn about unresolved symbols in shared libraries.
2971 this->warn_about_undefined_dynobj_symbol(sym
);
2973 unsigned int sym_index
= sym
->symtab_index();
2974 unsigned int dynsym_index
;
2975 if (dynamic_view
== NULL
)
2978 dynsym_index
= sym
->dynsym_index();
2980 if (sym_index
== -1U && dynsym_index
== -1U)
2982 // This symbol is not included in the output file.
2987 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
2988 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
2989 elfcpp::STB binding
= sym
->binding();
2991 // If --weak-unresolved-symbols is set, change binding of unresolved
2992 // global symbols to STB_WEAK.
2993 if (parameters
->options().weak_unresolved_symbols()
2994 && binding
== elfcpp::STB_GLOBAL
2995 && sym
->is_undefined())
2996 binding
= elfcpp::STB_WEAK
;
2998 // If --no-gnu-unique is set, change STB_GNU_UNIQUE to STB_GLOBAL.
2999 if (binding
== elfcpp::STB_GNU_UNIQUE
3000 && !parameters
->options().gnu_unique())
3001 binding
= elfcpp::STB_GLOBAL
;
3003 switch (sym
->source())
3005 case Symbol::FROM_OBJECT
:
3008 unsigned int in_shndx
= sym
->shndx(&is_ordinary
);
3011 && in_shndx
!= elfcpp::SHN_ABS
3012 && !Symbol::is_common_shndx(in_shndx
))
3014 gold_error(_("%s: unsupported symbol section 0x%x"),
3015 sym
->demangled_name().c_str(), in_shndx
);
3020 Object
* symobj
= sym
->object();
3021 if (symobj
->is_dynamic())
3023 if (sym
->needs_dynsym_value())
3024 dynsym_value
= target
.dynsym_value(sym
);
3025 shndx
= elfcpp::SHN_UNDEF
;
3026 if (sym
->is_undef_binding_weak())
3027 binding
= elfcpp::STB_WEAK
;
3029 binding
= elfcpp::STB_GLOBAL
;
3031 else if (symobj
->pluginobj() != NULL
)
3032 shndx
= elfcpp::SHN_UNDEF
;
3033 else if (in_shndx
== elfcpp::SHN_UNDEF
3035 && (in_shndx
== elfcpp::SHN_ABS
3036 || Symbol::is_common_shndx(in_shndx
))))
3040 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
3041 Output_section
* os
= relobj
->output_section(in_shndx
);
3042 if (this->is_section_folded(relobj
, in_shndx
))
3044 // This global symbol must be written out even though
3046 // Get the os of the section it is folded onto.
3048 this->icf_
->get_folded_section(relobj
, in_shndx
);
3049 gold_assert(folded
.first
!=NULL
);
3050 Relobj
* folded_obj
=
3051 reinterpret_cast<Relobj
*>(folded
.first
);
3052 os
= folded_obj
->output_section(folded
.second
);
3053 gold_assert(os
!= NULL
);
3055 gold_assert(os
!= NULL
);
3056 shndx
= os
->out_shndx();
3058 if (shndx
>= elfcpp::SHN_LORESERVE
)
3060 if (sym_index
!= -1U)
3061 symtab_xindex
->add(sym_index
, shndx
);
3062 if (dynsym_index
!= -1U)
3063 dynsym_xindex
->add(dynsym_index
, shndx
);
3064 shndx
= elfcpp::SHN_XINDEX
;
3067 // In object files symbol values are section
3069 if (parameters
->options().relocatable())
3070 sym_value
-= os
->address();
3076 case Symbol::IN_OUTPUT_DATA
:
3078 Output_data
* od
= sym
->output_data();
3080 shndx
= od
->out_shndx();
3081 if (shndx
>= elfcpp::SHN_LORESERVE
)
3083 if (sym_index
!= -1U)
3084 symtab_xindex
->add(sym_index
, shndx
);
3085 if (dynsym_index
!= -1U)
3086 dynsym_xindex
->add(dynsym_index
, shndx
);
3087 shndx
= elfcpp::SHN_XINDEX
;
3090 // In object files symbol values are section
3092 if (parameters
->options().relocatable())
3093 sym_value
-= od
->address();
3097 case Symbol::IN_OUTPUT_SEGMENT
:
3098 shndx
= elfcpp::SHN_ABS
;
3101 case Symbol::IS_CONSTANT
:
3102 shndx
= elfcpp::SHN_ABS
;
3105 case Symbol::IS_UNDEFINED
:
3106 shndx
= elfcpp::SHN_UNDEF
;
3113 if (sym_index
!= -1U)
3115 sym_index
-= first_global_index
;
3116 gold_assert(sym_index
< output_count
);
3117 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
3118 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
3119 binding
, sympool
, ps
);
3122 if (dynsym_index
!= -1U)
3124 dynsym_index
-= first_dynamic_global_index
;
3125 gold_assert(dynsym_index
< dynamic_count
);
3126 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
3127 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
3128 binding
, dynpool
, pd
);
3129 // Allow a target to adjust dynamic symbol value.
3130 parameters
->target().adjust_dyn_symbol(sym
, pd
);
3134 // Write the target-specific symbols.
3135 for (std::vector
<Symbol
*>::const_iterator p
= this->target_symbols_
.begin();
3136 p
!= this->target_symbols_
.end();
3139 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(*p
);
3141 unsigned int sym_index
= sym
->symtab_index();
3142 unsigned int dynsym_index
;
3143 if (dynamic_view
== NULL
)
3146 dynsym_index
= sym
->dynsym_index();
3149 switch (sym
->source())
3151 case Symbol::IS_CONSTANT
:
3152 shndx
= elfcpp::SHN_ABS
;
3154 case Symbol::IS_UNDEFINED
:
3155 shndx
= elfcpp::SHN_UNDEF
;
3161 if (sym_index
!= -1U)
3163 sym_index
-= first_global_index
;
3164 gold_assert(sym_index
< output_count
);
3165 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
3166 this->sized_write_symbol
<size
, big_endian
>(sym
, sym
->value(), shndx
,
3167 sym
->binding(), sympool
,
3171 if (dynsym_index
!= -1U)
3173 dynsym_index
-= first_dynamic_global_index
;
3174 gold_assert(dynsym_index
< dynamic_count
);
3175 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
3176 this->sized_write_symbol
<size
, big_endian
>(sym
, sym
->value(), shndx
,
3177 sym
->binding(), dynpool
,
3182 of
->write_output_view(this->offset_
, oview_size
, psyms
);
3183 if (dynamic_view
!= NULL
)
3184 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
3187 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
3188 // strtab holding the name.
3190 template<int size
, bool big_endian
>
3192 Symbol_table::sized_write_symbol(
3193 Sized_symbol
<size
>* sym
,
3194 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
3196 elfcpp::STB binding
,
3197 const Stringpool
* pool
,
3198 unsigned char* p
) const
3200 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
3201 if (sym
->version() == NULL
|| !parameters
->options().relocatable())
3202 osym
.put_st_name(pool
->get_offset(sym
->name()));
3204 osym
.put_st_name(pool
->get_offset(sym
->versioned_name()));
3205 osym
.put_st_value(value
);
3206 // Use a symbol size of zero for undefined symbols from shared libraries.
3207 if (shndx
== elfcpp::SHN_UNDEF
&& sym
->is_from_dynobj())
3208 osym
.put_st_size(0);
3210 osym
.put_st_size(sym
->symsize());
3211 elfcpp::STT type
= sym
->type();
3212 gold_assert(type
!= elfcpp::STT_GNU_IFUNC
|| !sym
->is_from_dynobj());
3213 // A version script may have overridden the default binding.
3214 if (sym
->is_forced_local())
3215 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, type
));
3217 osym
.put_st_info(elfcpp::elf_st_info(binding
, type
));
3218 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
3219 osym
.put_st_shndx(shndx
);
3222 // Check for unresolved symbols in shared libraries. This is
3223 // controlled by the --allow-shlib-undefined option.
3225 // We only warn about libraries for which we have seen all the
3226 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
3227 // which were not seen in this link. If we didn't see a DT_NEEDED
3228 // entry, we aren't going to be able to reliably report whether the
3229 // symbol is undefined.
3231 // We also don't warn about libraries found in a system library
3232 // directory (e.g., /lib or /usr/lib); we assume that those libraries
3233 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
3234 // can have undefined references satisfied by ld-linux.so.
3237 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol
* sym
) const
3240 if (sym
->source() == Symbol::FROM_OBJECT
3241 && sym
->object()->is_dynamic()
3242 && sym
->shndx(&dummy
) == elfcpp::SHN_UNDEF
3243 && sym
->binding() != elfcpp::STB_WEAK
3244 && !parameters
->options().allow_shlib_undefined()
3245 && !parameters
->target().is_defined_by_abi(sym
)
3246 && !sym
->object()->is_in_system_directory())
3248 // A very ugly cast.
3249 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
3250 if (!dynobj
->has_unknown_needed_entries())
3251 gold_undefined_symbol(sym
);
3255 // Write out a section symbol. Return the update offset.
3258 Symbol_table::write_section_symbol(const Output_section
* os
,
3259 Output_symtab_xindex
* symtab_xindex
,
3263 switch (parameters
->size_and_endianness())
3265 #ifdef HAVE_TARGET_32_LITTLE
3266 case Parameters::TARGET_32_LITTLE
:
3267 this->sized_write_section_symbol
<32, false>(os
, symtab_xindex
, of
,
3271 #ifdef HAVE_TARGET_32_BIG
3272 case Parameters::TARGET_32_BIG
:
3273 this->sized_write_section_symbol
<32, true>(os
, symtab_xindex
, of
,
3277 #ifdef HAVE_TARGET_64_LITTLE
3278 case Parameters::TARGET_64_LITTLE
:
3279 this->sized_write_section_symbol
<64, false>(os
, symtab_xindex
, of
,
3283 #ifdef HAVE_TARGET_64_BIG
3284 case Parameters::TARGET_64_BIG
:
3285 this->sized_write_section_symbol
<64, true>(os
, symtab_xindex
, of
,
3294 // Write out a section symbol, specialized for size and endianness.
3296 template<int size
, bool big_endian
>
3298 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
3299 Output_symtab_xindex
* symtab_xindex
,
3303 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
3305 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
3307 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
3308 osym
.put_st_name(0);
3309 if (parameters
->options().relocatable())
3310 osym
.put_st_value(0);
3312 osym
.put_st_value(os
->address());
3313 osym
.put_st_size(0);
3314 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
3315 elfcpp::STT_SECTION
));
3316 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
3318 unsigned int shndx
= os
->out_shndx();
3319 if (shndx
>= elfcpp::SHN_LORESERVE
)
3321 symtab_xindex
->add(os
->symtab_index(), shndx
);
3322 shndx
= elfcpp::SHN_XINDEX
;
3324 osym
.put_st_shndx(shndx
);
3326 of
->write_output_view(offset
, sym_size
, pov
);
3329 // Print statistical information to stderr. This is used for --stats.
3332 Symbol_table::print_stats() const
3334 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
3335 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
3336 program_name
, this->table_
.size(), this->table_
.bucket_count());
3338 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
3339 program_name
, this->table_
.size());
3341 this->namepool_
.print_stats("symbol table stringpool");
3344 // We check for ODR violations by looking for symbols with the same
3345 // name for which the debugging information reports that they were
3346 // defined in disjoint source locations. When comparing the source
3347 // location, we consider instances with the same base filename to be
3348 // the same. This is because different object files/shared libraries
3349 // can include the same header file using different paths, and
3350 // different optimization settings can make the line number appear to
3351 // be a couple lines off, and we don't want to report an ODR violation
3354 // This struct is used to compare line information, as returned by
3355 // Dwarf_line_info::one_addr2line. It implements a < comparison
3356 // operator used with std::sort.
3358 struct Odr_violation_compare
3361 operator()(const std::string
& s1
, const std::string
& s2
) const
3363 // Inputs should be of the form "dirname/filename:linenum" where
3364 // "dirname/" is optional. We want to compare just the filename:linenum.
3366 // Find the last '/' in each string.
3367 std::string::size_type s1begin
= s1
.rfind('/');
3368 std::string::size_type s2begin
= s2
.rfind('/');
3369 // If there was no '/' in a string, start at the beginning.
3370 if (s1begin
== std::string::npos
)
3372 if (s2begin
== std::string::npos
)
3374 return s1
.compare(s1begin
, std::string::npos
,
3375 s2
, s2begin
, std::string::npos
) < 0;
3379 // Returns all of the lines attached to LOC, not just the one the
3380 // instruction actually came from.
3381 std::vector
<std::string
>
3382 Symbol_table::linenos_from_loc(const Task
* task
,
3383 const Symbol_location
& loc
)
3385 // We need to lock the object in order to read it. This
3386 // means that we have to run in a singleton Task. If we
3387 // want to run this in a general Task for better
3388 // performance, we will need one Task for object, plus
3389 // appropriate locking to ensure that we don't conflict with
3390 // other uses of the object. Also note, one_addr2line is not
3391 // currently thread-safe.
3392 Task_lock_obj
<Object
> tl(task
, loc
.object
);
3394 std::vector
<std::string
> result
;
3395 Symbol_location code_loc
= loc
;
3396 parameters
->target().function_location(&code_loc
);
3397 // 16 is the size of the object-cache that one_addr2line should use.
3398 std::string canonical_result
= Dwarf_line_info::one_addr2line(
3399 code_loc
.object
, code_loc
.shndx
, code_loc
.offset
, 16, &result
);
3400 if (!canonical_result
.empty())
3401 result
.push_back(canonical_result
);
3405 // OutputIterator that records if it was ever assigned to. This
3406 // allows it to be used with std::set_intersection() to check for
3407 // intersection rather than computing the intersection.
3408 struct Check_intersection
3410 Check_intersection()
3414 bool had_intersection() const
3415 { return this->value_
; }
3417 Check_intersection
& operator++()
3420 Check_intersection
& operator*()
3423 template<typename T
>
3424 Check_intersection
& operator=(const T
&)
3426 this->value_
= true;
3434 // Check candidate_odr_violations_ to find symbols with the same name
3435 // but apparently different definitions (different source-file/line-no
3436 // for each line assigned to the first instruction).
3439 Symbol_table::detect_odr_violations(const Task
* task
,
3440 const char* output_file_name
) const
3442 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
3443 it
!= candidate_odr_violations_
.end();
3446 const char* const symbol_name
= it
->first
;
3448 std::string first_object_name
;
3449 std::vector
<std::string
> first_object_linenos
;
3451 Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
3452 locs
= it
->second
.begin();
3453 const Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
3454 locs_end
= it
->second
.end();
3455 for (; locs
!= locs_end
&& first_object_linenos
.empty(); ++locs
)
3457 // Save the line numbers from the first definition to
3458 // compare to the other definitions. Ideally, we'd compare
3459 // every definition to every other, but we don't want to
3460 // take O(N^2) time to do this. This shortcut may cause
3461 // false negatives that appear or disappear depending on the
3462 // link order, but it won't cause false positives.
3463 first_object_name
= locs
->object
->name();
3464 first_object_linenos
= this->linenos_from_loc(task
, *locs
);
3466 if (first_object_linenos
.empty())
3469 // Sort by Odr_violation_compare to make std::set_intersection work.
3470 std::string first_object_canonical_result
= first_object_linenos
.back();
3471 std::sort(first_object_linenos
.begin(), first_object_linenos
.end(),
3472 Odr_violation_compare());
3474 for (; locs
!= locs_end
; ++locs
)
3476 std::vector
<std::string
> linenos
=
3477 this->linenos_from_loc(task
, *locs
);
3478 // linenos will be empty if we couldn't parse the debug info.
3479 if (linenos
.empty())
3481 // Sort by Odr_violation_compare to make std::set_intersection work.
3482 gold_assert(!linenos
.empty());
3483 std::string second_object_canonical_result
= linenos
.back();
3484 std::sort(linenos
.begin(), linenos
.end(), Odr_violation_compare());
3486 Check_intersection intersection_result
=
3487 std::set_intersection(first_object_linenos
.begin(),
3488 first_object_linenos
.end(),
3491 Check_intersection(),
3492 Odr_violation_compare());
3493 if (!intersection_result
.had_intersection())
3495 gold_warning(_("while linking %s: symbol '%s' defined in "
3496 "multiple places (possible ODR violation):"),
3497 output_file_name
, demangle(symbol_name
).c_str());
3498 // This only prints one location from each definition,
3499 // which may not be the location we expect to intersect
3500 // with another definition. We could print the whole
3501 // set of locations, but that seems too verbose.
3502 fprintf(stderr
, _(" %s from %s\n"),
3503 first_object_canonical_result
.c_str(),
3504 first_object_name
.c_str());
3505 fprintf(stderr
, _(" %s from %s\n"),
3506 second_object_canonical_result
.c_str(),
3507 locs
->object
->name().c_str());
3508 // Only print one broken pair, to avoid needing to
3509 // compare against a list of the disjoint definition
3510 // locations we've found so far. (If we kept comparing
3511 // against just the first one, we'd get a lot of
3512 // redundant complaints about the second definition
3518 // We only call one_addr2line() in this function, so we can clear its cache.
3519 Dwarf_line_info::clear_addr2line_cache();
3522 // Warnings functions.
3524 // Add a new warning.
3527 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
3528 const std::string
& warning
)
3530 name
= symtab
->canonicalize_name(name
);
3531 this->warnings_
[name
].set(obj
, warning
);
3534 // Look through the warnings and mark the symbols for which we should
3535 // warn. This is called during Layout::finalize when we know the
3536 // sources for all the symbols.
3539 Warnings::note_warnings(Symbol_table
* symtab
)
3541 for (Warning_table::iterator p
= this->warnings_
.begin();
3542 p
!= this->warnings_
.end();
3545 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
3547 && sym
->source() == Symbol::FROM_OBJECT
3548 && sym
->object() == p
->second
.object
)
3549 sym
->set_has_warning();
3553 // Issue a warning. This is called when we see a relocation against a
3554 // symbol for which has a warning.
3556 template<int size
, bool big_endian
>
3558 Warnings::issue_warning(const Symbol
* sym
,
3559 const Relocate_info
<size
, big_endian
>* relinfo
,
3560 size_t relnum
, off_t reloffset
) const
3562 gold_assert(sym
->has_warning());
3564 // We don't want to issue a warning for a relocation against the
3565 // symbol in the same object file in which the symbol is defined.
3566 if (sym
->object() == relinfo
->object
)
3569 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
3570 gold_assert(p
!= this->warnings_
.end());
3571 gold_warning_at_location(relinfo
, relnum
, reloffset
,
3572 "%s", p
->second
.text
.c_str());
3575 // Instantiate the templates we need. We could use the configure
3576 // script to restrict this to only the ones needed for implemented
3579 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3582 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
3585 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3588 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
3591 #ifdef HAVE_TARGET_32_LITTLE
3594 Symbol_table::add_from_relobj
<32, false>(
3595 Sized_relobj_file
<32, false>* relobj
,
3596 const unsigned char* syms
,
3598 size_t symndx_offset
,
3599 const char* sym_names
,
3600 size_t sym_name_size
,
3601 Sized_relobj_file
<32, false>::Symbols
* sympointers
,
3605 #ifdef HAVE_TARGET_32_BIG
3608 Symbol_table::add_from_relobj
<32, true>(
3609 Sized_relobj_file
<32, true>* relobj
,
3610 const unsigned char* syms
,
3612 size_t symndx_offset
,
3613 const char* sym_names
,
3614 size_t sym_name_size
,
3615 Sized_relobj_file
<32, true>::Symbols
* sympointers
,
3619 #ifdef HAVE_TARGET_64_LITTLE
3622 Symbol_table::add_from_relobj
<64, false>(
3623 Sized_relobj_file
<64, false>* relobj
,
3624 const unsigned char* syms
,
3626 size_t symndx_offset
,
3627 const char* sym_names
,
3628 size_t sym_name_size
,
3629 Sized_relobj_file
<64, false>::Symbols
* sympointers
,
3633 #ifdef HAVE_TARGET_64_BIG
3636 Symbol_table::add_from_relobj
<64, true>(
3637 Sized_relobj_file
<64, true>* relobj
,
3638 const unsigned char* syms
,
3640 size_t symndx_offset
,
3641 const char* sym_names
,
3642 size_t sym_name_size
,
3643 Sized_relobj_file
<64, true>::Symbols
* sympointers
,
3647 #ifdef HAVE_TARGET_32_LITTLE
3650 Symbol_table::add_from_pluginobj
<32, false>(
3651 Sized_pluginobj
<32, false>* obj
,
3654 elfcpp::Sym
<32, false>* sym
);
3657 #ifdef HAVE_TARGET_32_BIG
3660 Symbol_table::add_from_pluginobj
<32, true>(
3661 Sized_pluginobj
<32, true>* obj
,
3664 elfcpp::Sym
<32, true>* sym
);
3667 #ifdef HAVE_TARGET_64_LITTLE
3670 Symbol_table::add_from_pluginobj
<64, false>(
3671 Sized_pluginobj
<64, false>* obj
,
3674 elfcpp::Sym
<64, false>* sym
);
3677 #ifdef HAVE_TARGET_64_BIG
3680 Symbol_table::add_from_pluginobj
<64, true>(
3681 Sized_pluginobj
<64, true>* obj
,
3684 elfcpp::Sym
<64, true>* sym
);
3687 #ifdef HAVE_TARGET_32_LITTLE
3690 Symbol_table::add_from_dynobj
<32, false>(
3691 Sized_dynobj
<32, false>* dynobj
,
3692 const unsigned char* syms
,
3694 const char* sym_names
,
3695 size_t sym_name_size
,
3696 const unsigned char* versym
,
3698 const std::vector
<const char*>* version_map
,
3699 Sized_relobj_file
<32, false>::Symbols
* sympointers
,
3703 #ifdef HAVE_TARGET_32_BIG
3706 Symbol_table::add_from_dynobj
<32, true>(
3707 Sized_dynobj
<32, true>* dynobj
,
3708 const unsigned char* syms
,
3710 const char* sym_names
,
3711 size_t sym_name_size
,
3712 const unsigned char* versym
,
3714 const std::vector
<const char*>* version_map
,
3715 Sized_relobj_file
<32, true>::Symbols
* sympointers
,
3719 #ifdef HAVE_TARGET_64_LITTLE
3722 Symbol_table::add_from_dynobj
<64, false>(
3723 Sized_dynobj
<64, false>* dynobj
,
3724 const unsigned char* syms
,
3726 const char* sym_names
,
3727 size_t sym_name_size
,
3728 const unsigned char* versym
,
3730 const std::vector
<const char*>* version_map
,
3731 Sized_relobj_file
<64, false>::Symbols
* sympointers
,
3735 #ifdef HAVE_TARGET_64_BIG
3738 Symbol_table::add_from_dynobj
<64, true>(
3739 Sized_dynobj
<64, true>* dynobj
,
3740 const unsigned char* syms
,
3742 const char* sym_names
,
3743 size_t sym_name_size
,
3744 const unsigned char* versym
,
3746 const std::vector
<const char*>* version_map
,
3747 Sized_relobj_file
<64, true>::Symbols
* sympointers
,
3751 #ifdef HAVE_TARGET_32_LITTLE
3754 Symbol_table::add_from_incrobj(
3758 elfcpp::Sym
<32, false>* sym
);
3761 #ifdef HAVE_TARGET_32_BIG
3764 Symbol_table::add_from_incrobj(
3768 elfcpp::Sym
<32, true>* sym
);
3771 #ifdef HAVE_TARGET_64_LITTLE
3774 Symbol_table::add_from_incrobj(
3778 elfcpp::Sym
<64, false>* sym
);
3781 #ifdef HAVE_TARGET_64_BIG
3784 Symbol_table::add_from_incrobj(
3788 elfcpp::Sym
<64, true>* sym
);
3791 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3794 Symbol_table::define_with_copy_reloc
<32>(
3795 Sized_symbol
<32>* sym
,
3797 elfcpp::Elf_types
<32>::Elf_Addr value
);
3800 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3803 Symbol_table::define_with_copy_reloc
<64>(
3804 Sized_symbol
<64>* sym
,
3806 elfcpp::Elf_types
<64>::Elf_Addr value
);
3809 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3812 Sized_symbol
<32>::init_output_data(const char* name
, const char* version
,
3813 Output_data
* od
, Value_type value
,
3814 Size_type symsize
, elfcpp::STT type
,
3815 elfcpp::STB binding
,
3816 elfcpp::STV visibility
,
3817 unsigned char nonvis
,
3818 bool offset_is_from_end
,
3819 bool is_predefined
);
3823 Sized_symbol
<32>::init_constant(const char* name
, const char* version
,
3824 Value_type value
, Size_type symsize
,
3825 elfcpp::STT type
, elfcpp::STB binding
,
3826 elfcpp::STV visibility
, unsigned char nonvis
,
3827 bool is_predefined
);
3831 Sized_symbol
<32>::init_undefined(const char* name
, const char* version
,
3832 Value_type value
, elfcpp::STT type
,
3833 elfcpp::STB binding
, elfcpp::STV visibility
,
3834 unsigned char nonvis
);
3837 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3840 Sized_symbol
<64>::init_output_data(const char* name
, const char* version
,
3841 Output_data
* od
, Value_type value
,
3842 Size_type symsize
, elfcpp::STT type
,
3843 elfcpp::STB binding
,
3844 elfcpp::STV visibility
,
3845 unsigned char nonvis
,
3846 bool offset_is_from_end
,
3847 bool is_predefined
);
3851 Sized_symbol
<64>::init_constant(const char* name
, const char* version
,
3852 Value_type value
, Size_type symsize
,
3853 elfcpp::STT type
, elfcpp::STB binding
,
3854 elfcpp::STV visibility
, unsigned char nonvis
,
3855 bool is_predefined
);
3859 Sized_symbol
<64>::init_undefined(const char* name
, const char* version
,
3860 Value_type value
, elfcpp::STT type
,
3861 elfcpp::STB binding
, elfcpp::STV visibility
,
3862 unsigned char nonvis
);
3865 #ifdef HAVE_TARGET_32_LITTLE
3868 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
3869 const Relocate_info
<32, false>* relinfo
,
3870 size_t relnum
, off_t reloffset
) const;
3873 #ifdef HAVE_TARGET_32_BIG
3876 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
3877 const Relocate_info
<32, true>* relinfo
,
3878 size_t relnum
, off_t reloffset
) const;
3881 #ifdef HAVE_TARGET_64_LITTLE
3884 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
3885 const Relocate_info
<64, false>* relinfo
,
3886 size_t relnum
, off_t reloffset
) const;
3889 #ifdef HAVE_TARGET_64_BIG
3892 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
3893 const Relocate_info
<64, true>* relinfo
,
3894 size_t relnum
, off_t reloffset
) const;
3897 } // End namespace gold.