1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007, 2008, 2009 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"
41 #include "demangle.h" // needed for --dynamic-list-cpp-new
49 // Initialize fields in Symbol. This initializes everything except u_
53 Symbol::init_fields(const char* name
, const char* version
,
54 elfcpp::STT type
, elfcpp::STB binding
,
55 elfcpp::STV visibility
, unsigned char nonvis
)
58 this->version_
= version
;
59 this->symtab_index_
= 0;
60 this->dynsym_index_
= 0;
61 this->got_offsets_
.init();
62 this->plt_offset_
= 0;
64 this->binding_
= binding
;
65 this->visibility_
= visibility
;
66 this->nonvis_
= nonvis
;
67 this->is_target_special_
= false;
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_plt_offset_
= false;
75 this->has_warning_
= false;
76 this->is_copied_from_dynobj_
= false;
77 this->is_forced_local_
= false;
78 this->is_ordinary_shndx_
= false;
79 this->in_real_elf_
= false;
82 // Return the demangled version of the symbol's name, but only
83 // if the --demangle flag was set.
86 demangle(const char* name
)
88 if (!parameters
->options().do_demangle())
91 // cplus_demangle allocates memory for the result it returns,
92 // and returns NULL if the name is already demangled.
93 char* demangled_name
= cplus_demangle(name
, DMGL_ANSI
| DMGL_PARAMS
);
94 if (demangled_name
== NULL
)
97 std::string
retval(demangled_name
);
103 Symbol::demangled_name() const
105 return demangle(this->name());
108 // Initialize the fields in the base class Symbol for SYM in OBJECT.
110 template<int size
, bool big_endian
>
112 Symbol::init_base_object(const char* name
, const char* version
, Object
* object
,
113 const elfcpp::Sym
<size
, big_endian
>& sym
,
114 unsigned int st_shndx
, bool is_ordinary
)
116 this->init_fields(name
, version
, sym
.get_st_type(), sym
.get_st_bind(),
117 sym
.get_st_visibility(), sym
.get_st_nonvis());
118 this->u_
.from_object
.object
= object
;
119 this->u_
.from_object
.shndx
= st_shndx
;
120 this->is_ordinary_shndx_
= is_ordinary
;
121 this->source_
= FROM_OBJECT
;
122 this->in_reg_
= !object
->is_dynamic();
123 this->in_dyn_
= object
->is_dynamic();
124 this->in_real_elf_
= object
->pluginobj() == NULL
;
127 // Initialize the fields in the base class Symbol for a symbol defined
128 // in an Output_data.
131 Symbol::init_base_output_data(const char* name
, const char* version
,
132 Output_data
* od
, elfcpp::STT type
,
133 elfcpp::STB binding
, elfcpp::STV visibility
,
134 unsigned char nonvis
, bool offset_is_from_end
)
136 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
137 this->u_
.in_output_data
.output_data
= od
;
138 this->u_
.in_output_data
.offset_is_from_end
= offset_is_from_end
;
139 this->source_
= IN_OUTPUT_DATA
;
140 this->in_reg_
= true;
141 this->in_real_elf_
= true;
144 // Initialize the fields in the base class Symbol for a symbol defined
145 // in an Output_segment.
148 Symbol::init_base_output_segment(const char* name
, const char* version
,
149 Output_segment
* os
, elfcpp::STT type
,
150 elfcpp::STB binding
, elfcpp::STV visibility
,
151 unsigned char nonvis
,
152 Segment_offset_base offset_base
)
154 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
155 this->u_
.in_output_segment
.output_segment
= os
;
156 this->u_
.in_output_segment
.offset_base
= offset_base
;
157 this->source_
= IN_OUTPUT_SEGMENT
;
158 this->in_reg_
= true;
159 this->in_real_elf_
= true;
162 // Initialize the fields in the base class Symbol for a symbol defined
166 Symbol::init_base_constant(const char* name
, const char* version
,
167 elfcpp::STT type
, elfcpp::STB binding
,
168 elfcpp::STV visibility
, unsigned char nonvis
)
170 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
171 this->source_
= IS_CONSTANT
;
172 this->in_reg_
= true;
173 this->in_real_elf_
= true;
176 // Initialize the fields in the base class Symbol for an undefined
180 Symbol::init_base_undefined(const char* name
, const char* version
,
181 elfcpp::STT type
, elfcpp::STB binding
,
182 elfcpp::STV visibility
, unsigned char nonvis
)
184 this->init_fields(name
, version
, type
, binding
, visibility
, nonvis
);
185 this->dynsym_index_
= -1U;
186 this->source_
= IS_UNDEFINED
;
187 this->in_reg_
= true;
188 this->in_real_elf_
= true;
191 // Allocate a common symbol in the base.
194 Symbol::allocate_base_common(Output_data
* od
)
196 gold_assert(this->is_common());
197 this->source_
= IN_OUTPUT_DATA
;
198 this->u_
.in_output_data
.output_data
= od
;
199 this->u_
.in_output_data
.offset_is_from_end
= false;
202 // Initialize the fields in Sized_symbol for SYM in OBJECT.
205 template<bool big_endian
>
207 Sized_symbol
<size
>::init_object(const char* name
, const char* version
,
209 const elfcpp::Sym
<size
, big_endian
>& sym
,
210 unsigned int st_shndx
, bool is_ordinary
)
212 this->init_base_object(name
, version
, object
, sym
, st_shndx
, is_ordinary
);
213 this->value_
= sym
.get_st_value();
214 this->symsize_
= sym
.get_st_size();
217 // Initialize the fields in Sized_symbol for a symbol defined in an
222 Sized_symbol
<size
>::init_output_data(const char* name
, const char* version
,
223 Output_data
* od
, Value_type value
,
224 Size_type symsize
, elfcpp::STT type
,
226 elfcpp::STV visibility
,
227 unsigned char nonvis
,
228 bool offset_is_from_end
)
230 this->init_base_output_data(name
, version
, od
, type
, binding
, visibility
,
231 nonvis
, offset_is_from_end
);
232 this->value_
= value
;
233 this->symsize_
= symsize
;
236 // Initialize the fields in Sized_symbol for a symbol defined in an
241 Sized_symbol
<size
>::init_output_segment(const char* name
, const char* version
,
242 Output_segment
* os
, Value_type value
,
243 Size_type symsize
, elfcpp::STT type
,
245 elfcpp::STV visibility
,
246 unsigned char nonvis
,
247 Segment_offset_base offset_base
)
249 this->init_base_output_segment(name
, version
, os
, type
, binding
, visibility
,
250 nonvis
, offset_base
);
251 this->value_
= value
;
252 this->symsize_
= symsize
;
255 // Initialize the fields in Sized_symbol for a symbol defined as a
260 Sized_symbol
<size
>::init_constant(const char* name
, const char* version
,
261 Value_type value
, Size_type symsize
,
262 elfcpp::STT type
, elfcpp::STB binding
,
263 elfcpp::STV visibility
, unsigned char nonvis
)
265 this->init_base_constant(name
, version
, type
, binding
, visibility
, nonvis
);
266 this->value_
= value
;
267 this->symsize_
= symsize
;
270 // Initialize the fields in Sized_symbol for an undefined symbol.
274 Sized_symbol
<size
>::init_undefined(const char* name
, const char* version
,
275 elfcpp::STT type
, elfcpp::STB binding
,
276 elfcpp::STV visibility
, unsigned char nonvis
)
278 this->init_base_undefined(name
, version
, type
, binding
, visibility
, nonvis
);
283 // Allocate a common symbol.
287 Sized_symbol
<size
>::allocate_common(Output_data
* od
, Value_type value
)
289 this->allocate_base_common(od
);
290 this->value_
= value
;
293 // The ""'s around str ensure str is a string literal, so sizeof works.
294 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
296 // Return true if this symbol should be added to the dynamic symbol
300 Symbol::should_add_dynsym_entry() const
302 // If the symbol is used by a dynamic relocation, we need to add it.
303 if (this->needs_dynsym_entry())
306 // If this symbol's section is not added, the symbol need not be added.
307 // The section may have been GCed. Note that export_dynamic is being
308 // overridden here. This should not be done for shared objects.
309 if (parameters
->options().gc_sections()
310 && !parameters
->options().shared()
311 && this->source() == Symbol::FROM_OBJECT
312 && !this->object()->is_dynamic())
314 Relobj
* relobj
= static_cast<Relobj
*>(this->object());
316 unsigned int shndx
= this->shndx(&is_ordinary
);
317 if (is_ordinary
&& shndx
!= elfcpp::SHN_UNDEF
318 && !relobj
->is_section_included(shndx
))
322 // If the symbol was forced local in a version script, do not add it.
323 if (this->is_forced_local())
326 // If the symbol was forced dynamic in a --dynamic-list file, add it.
327 if (parameters
->options().in_dynamic_list(this->name()))
330 // If dynamic-list-data was specified, add any STT_OBJECT.
331 if (parameters
->options().dynamic_list_data()
332 && !this->is_from_dynobj()
333 && this->type() == elfcpp::STT_OBJECT
)
336 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
337 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
338 if ((parameters
->options().dynamic_list_cpp_new()
339 || parameters
->options().dynamic_list_cpp_typeinfo())
340 && !this->is_from_dynobj())
342 // TODO(csilvers): We could probably figure out if we're an operator
343 // new/delete or typeinfo without the need to demangle.
344 char* demangled_name
= cplus_demangle(this->name(),
345 DMGL_ANSI
| DMGL_PARAMS
);
346 if (demangled_name
== NULL
)
348 // Not a C++ symbol, so it can't satisfy these flags
350 else if (parameters
->options().dynamic_list_cpp_new()
351 && (strprefix(demangled_name
, "operator new")
352 || strprefix(demangled_name
, "operator delete")))
354 free(demangled_name
);
357 else if (parameters
->options().dynamic_list_cpp_typeinfo()
358 && (strprefix(demangled_name
, "typeinfo name for")
359 || strprefix(demangled_name
, "typeinfo for")))
361 free(demangled_name
);
365 free(demangled_name
);
368 // If exporting all symbols or building a shared library,
369 // and the symbol is defined in a regular object and is
370 // externally visible, we need to add it.
371 if ((parameters
->options().export_dynamic() || parameters
->options().shared())
372 && !this->is_from_dynobj()
373 && this->is_externally_visible())
379 // Return true if the final value of this symbol is known at link
383 Symbol::final_value_is_known() const
385 // If we are not generating an executable, then no final values are
386 // known, since they will change at runtime.
387 if (parameters
->options().shared() || parameters
->options().relocatable())
390 // If the symbol is not from an object file, and is not undefined,
391 // then it is defined, and known.
392 if (this->source_
!= FROM_OBJECT
)
394 if (this->source_
!= IS_UNDEFINED
)
399 // If the symbol is from a dynamic object, then the final value
401 if (this->object()->is_dynamic())
404 // If the symbol is not undefined (it is defined or common),
405 // then the final value is known.
406 if (!this->is_undefined())
410 // If the symbol is undefined, then whether the final value is known
411 // depends on whether we are doing a static link. If we are doing a
412 // dynamic link, then the final value could be filled in at runtime.
413 // This could reasonably be the case for a weak undefined symbol.
414 return parameters
->doing_static_link();
417 // Return the output section where this symbol is defined.
420 Symbol::output_section() const
422 switch (this->source_
)
426 unsigned int shndx
= this->u_
.from_object
.shndx
;
427 if (shndx
!= elfcpp::SHN_UNDEF
&& this->is_ordinary_shndx_
)
429 gold_assert(!this->u_
.from_object
.object
->is_dynamic());
430 gold_assert(this->u_
.from_object
.object
->pluginobj() == NULL
);
431 Relobj
* relobj
= static_cast<Relobj
*>(this->u_
.from_object
.object
);
432 return relobj
->output_section(shndx
);
438 return this->u_
.in_output_data
.output_data
->output_section();
440 case IN_OUTPUT_SEGMENT
:
450 // Set the symbol's output section. This is used for symbols defined
451 // in scripts. This should only be called after the symbol table has
455 Symbol::set_output_section(Output_section
* os
)
457 switch (this->source_
)
461 gold_assert(this->output_section() == os
);
464 this->source_
= IN_OUTPUT_DATA
;
465 this->u_
.in_output_data
.output_data
= os
;
466 this->u_
.in_output_data
.offset_is_from_end
= false;
468 case IN_OUTPUT_SEGMENT
:
475 // Class Symbol_table.
477 Symbol_table::Symbol_table(unsigned int count
,
478 const Version_script_info
& version_script
)
479 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
480 forwarders_(), commons_(), tls_commons_(), forced_locals_(), warnings_(),
481 version_script_(version_script
), gc_(NULL
)
483 namepool_
.reserve(count
);
486 Symbol_table::~Symbol_table()
490 // The hash function. The key values are Stringpool keys.
493 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key
& key
) const
495 return key
.first
^ key
.second
;
498 // The symbol table key equality function. This is called with
502 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
503 const Symbol_table_key
& k2
) const
505 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
508 // For symbols that have been listed with -u option, add them to the
509 // work list to avoid gc'ing them.
512 Symbol_table::gc_mark_undef_symbols()
514 for (options::String_set::const_iterator p
=
515 parameters
->options().undefined_begin();
516 p
!= parameters
->options().undefined_end();
519 const char* name
= p
->c_str();
520 Symbol
* sym
= this->lookup(name
);
521 gold_assert (sym
!= NULL
);
522 if (sym
->source() == Symbol::FROM_OBJECT
523 && !sym
->object()->is_dynamic())
525 Relobj
* obj
= static_cast<Relobj
*>(sym
->object());
527 unsigned int shndx
= sym
->shndx(&is_ordinary
);
530 gold_assert(this->gc_
!= NULL
);
531 this->gc_
->worklist().push(Section_id(obj
, shndx
));
538 Symbol_table::gc_mark_symbol_for_shlib(Symbol
* sym
)
540 if (!sym
->is_from_dynobj()
541 && sym
->is_externally_visible())
543 //Add the object and section to the work list.
544 Relobj
* obj
= static_cast<Relobj
*>(sym
->object());
546 unsigned int shndx
= sym
->shndx(&is_ordinary
);
547 if (is_ordinary
&& shndx
!= elfcpp::SHN_UNDEF
)
549 gold_assert(this->gc_
!= NULL
);
550 this->gc_
->worklist().push(Section_id(obj
, shndx
));
555 // When doing garbage collection, keep symbols that have been seen in
558 Symbol_table::gc_mark_dyn_syms(Symbol
* sym
)
560 if (sym
->in_dyn() && sym
->source() == Symbol::FROM_OBJECT
561 && !sym
->object()->is_dynamic())
563 Relobj
*obj
= static_cast<Relobj
*>(sym
->object());
565 unsigned int shndx
= sym
->shndx(&is_ordinary
);
566 if (is_ordinary
&& shndx
!= elfcpp::SHN_UNDEF
)
568 gold_assert(this->gc_
!= NULL
);
569 this->gc_
->worklist().push(Section_id(obj
, shndx
));
574 // Make TO a symbol which forwards to FROM.
577 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
579 gold_assert(from
!= to
);
580 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
581 this->forwarders_
[from
] = to
;
582 from
->set_forwarder();
585 // Resolve the forwards from FROM, returning the real symbol.
588 Symbol_table::resolve_forwards(const Symbol
* from
) const
590 gold_assert(from
->is_forwarder());
591 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
592 this->forwarders_
.find(from
);
593 gold_assert(p
!= this->forwarders_
.end());
597 // Look up a symbol by name.
600 Symbol_table::lookup(const char* name
, const char* version
) const
602 Stringpool::Key name_key
;
603 name
= this->namepool_
.find(name
, &name_key
);
607 Stringpool::Key version_key
= 0;
610 version
= this->namepool_
.find(version
, &version_key
);
615 Symbol_table_key
key(name_key
, version_key
);
616 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
617 if (p
== this->table_
.end())
622 // Resolve a Symbol with another Symbol. This is only used in the
623 // unusual case where there are references to both an unversioned
624 // symbol and a symbol with a version, and we then discover that that
625 // version is the default version. Because this is unusual, we do
626 // this the slow way, by converting back to an ELF symbol.
628 template<int size
, bool big_endian
>
630 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
)
632 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
633 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
634 // We don't bother to set the st_name or the st_shndx field.
635 esym
.put_st_value(from
->value());
636 esym
.put_st_size(from
->symsize());
637 esym
.put_st_info(from
->binding(), from
->type());
638 esym
.put_st_other(from
->visibility(), from
->nonvis());
640 unsigned int shndx
= from
->shndx(&is_ordinary
);
641 this->resolve(to
, esym
.sym(), shndx
, is_ordinary
, shndx
, from
->object(),
647 if (parameters
->options().gc_sections())
648 this->gc_mark_dyn_syms(to
);
651 // Record that a symbol is forced to be local by a version script or
655 Symbol_table::force_local(Symbol
* sym
)
657 if (!sym
->is_defined() && !sym
->is_common())
659 if (sym
->is_forced_local())
661 // We already got this one.
664 sym
->set_is_forced_local();
665 this->forced_locals_
.push_back(sym
);
668 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
669 // is only called for undefined symbols, when at least one --wrap
673 Symbol_table::wrap_symbol(Object
* object
, const char* name
,
674 Stringpool::Key
* name_key
)
676 // For some targets, we need to ignore a specific character when
677 // wrapping, and add it back later.
679 if (name
[0] == object
->target()->wrap_char())
685 if (parameters
->options().is_wrap(name
))
687 // Turn NAME into __wrap_NAME.
694 // This will give us both the old and new name in NAMEPOOL_, but
695 // that is OK. Only the versions we need will wind up in the
696 // real string table in the output file.
697 return this->namepool_
.add(s
.c_str(), true, name_key
);
700 const char* const real_prefix
= "__real_";
701 const size_t real_prefix_length
= strlen(real_prefix
);
702 if (strncmp(name
, real_prefix
, real_prefix_length
) == 0
703 && parameters
->options().is_wrap(name
+ real_prefix_length
))
705 // Turn __real_NAME into NAME.
709 s
+= name
+ real_prefix_length
;
710 return this->namepool_
.add(s
.c_str(), true, name_key
);
716 // Add one symbol from OBJECT to the symbol table. NAME is symbol
717 // name and VERSION is the version; both are canonicalized. DEF is
718 // whether this is the default version. ST_SHNDX is the symbol's
719 // section index; IS_ORDINARY is whether this is a normal section
720 // rather than a special code.
722 // If DEF is true, then this is the definition of a default version of
723 // a symbol. That means that any lookup of NAME/NULL and any lookup
724 // of NAME/VERSION should always return the same symbol. This is
725 // obvious for references, but in particular we want to do this for
726 // definitions: overriding NAME/NULL should also override
727 // NAME/VERSION. If we don't do that, it would be very hard to
728 // override functions in a shared library which uses versioning.
730 // We implement this by simply making both entries in the hash table
731 // point to the same Symbol structure. That is easy enough if this is
732 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
733 // that we have seen both already, in which case they will both have
734 // independent entries in the symbol table. We can't simply change
735 // the symbol table entry, because we have pointers to the entries
736 // attached to the object files. So we mark the entry attached to the
737 // object file as a forwarder, and record it in the forwarders_ map.
738 // Note that entries in the hash table will never be marked as
741 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
742 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
743 // for a special section code. ST_SHNDX may be modified if the symbol
744 // is defined in a section being discarded.
746 template<int size
, bool big_endian
>
748 Symbol_table::add_from_object(Object
* object
,
750 Stringpool::Key name_key
,
752 Stringpool::Key version_key
,
754 const elfcpp::Sym
<size
, big_endian
>& sym
,
755 unsigned int st_shndx
,
757 unsigned int orig_st_shndx
)
759 // Print a message if this symbol is being traced.
760 if (parameters
->options().is_trace_symbol(name
))
762 if (orig_st_shndx
== elfcpp::SHN_UNDEF
)
763 gold_info(_("%s: reference to %s"), object
->name().c_str(), name
);
765 gold_info(_("%s: definition of %s"), object
->name().c_str(), name
);
768 // For an undefined symbol, we may need to adjust the name using
770 if (orig_st_shndx
== elfcpp::SHN_UNDEF
771 && parameters
->options().any_wrap())
773 const char* wrap_name
= this->wrap_symbol(object
, name
, &name_key
);
774 if (wrap_name
!= name
)
776 // If we see a reference to malloc with version GLIBC_2.0,
777 // and we turn it into a reference to __wrap_malloc, then we
778 // discard the version number. Otherwise the user would be
779 // required to specify the correct version for
787 Symbol
* const snull
= NULL
;
788 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
789 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
792 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
793 std::make_pair(this->table_
.end(), false);
796 const Stringpool::Key vnull_key
= 0;
797 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
802 // ins.first: an iterator, which is a pointer to a pair.
803 // ins.first->first: the key (a pair of name and version).
804 // ins.first->second: the value (Symbol*).
805 // ins.second: true if new entry was inserted, false if not.
807 Sized_symbol
<size
>* ret
;
812 // We already have an entry for NAME/VERSION.
813 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
814 gold_assert(ret
!= NULL
);
816 was_undefined
= ret
->is_undefined();
817 was_common
= ret
->is_common();
819 this->resolve(ret
, sym
, st_shndx
, is_ordinary
, orig_st_shndx
, object
,
821 if (parameters
->options().gc_sections())
822 this->gc_mark_dyn_syms(ret
);
828 // This is the first time we have seen NAME/NULL. Make
829 // NAME/NULL point to NAME/VERSION.
830 insdef
.first
->second
= ret
;
832 else if (insdef
.first
->second
!= ret
)
834 // This is the unfortunate case where we already have
835 // entries for both NAME/VERSION and NAME/NULL. We now
836 // see a symbol NAME/VERSION where VERSION is the
837 // default version. We have already resolved this new
838 // symbol with the existing NAME/VERSION symbol.
840 // It's possible that NAME/NULL and NAME/VERSION are
841 // both defined in regular objects. This can only
842 // happen if one object file defines foo and another
843 // defines foo@@ver. This is somewhat obscure, but we
844 // call it a multiple definition error.
846 // It's possible that NAME/NULL actually has a version,
847 // in which case it won't be the same as VERSION. This
848 // happens with ver_test_7.so in the testsuite for the
849 // symbol t2_2. We see t2_2@@VER2, so we define both
850 // t2_2/VER2 and t2_2/NULL. We then see an unadorned
851 // t2_2 in an object file and give it version VER1 from
852 // the version script. This looks like a default
853 // definition for VER1, so it looks like we should merge
854 // t2_2/NULL with t2_2/VER1. That doesn't make sense,
855 // but it's not obvious that this is an error, either.
858 // If one of the symbols has non-default visibility, and
859 // the other is defined in a shared object, then they
860 // are different symbols.
862 // Otherwise, we just resolve the symbols as though they
865 if (insdef
.first
->second
->version() != NULL
)
867 gold_assert(insdef
.first
->second
->version() != version
);
870 else if (ret
->visibility() != elfcpp::STV_DEFAULT
871 && insdef
.first
->second
->is_from_dynobj())
873 else if (insdef
.first
->second
->visibility() != elfcpp::STV_DEFAULT
874 && ret
->is_from_dynobj())
878 const Sized_symbol
<size
>* sym2
;
879 sym2
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
880 Symbol_table::resolve
<size
, big_endian
>(ret
, sym2
);
881 this->make_forwarder(insdef
.first
->second
, ret
);
882 insdef
.first
->second
= ret
;
891 // This is the first time we have seen NAME/VERSION.
892 gold_assert(ins
.first
->second
== NULL
);
894 if (def
&& !insdef
.second
)
896 // We already have an entry for NAME/NULL. If we override
897 // it, then change it to NAME/VERSION.
898 ret
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
900 was_undefined
= ret
->is_undefined();
901 was_common
= ret
->is_common();
903 this->resolve(ret
, sym
, st_shndx
, is_ordinary
, orig_st_shndx
, object
,
905 if (parameters
->options().gc_sections())
906 this->gc_mark_dyn_syms(ret
);
907 ins
.first
->second
= ret
;
911 was_undefined
= false;
914 Sized_target
<size
, big_endian
>* target
=
915 object
->sized_target
<size
, big_endian
>();
916 if (!target
->has_make_symbol())
917 ret
= new Sized_symbol
<size
>();
920 ret
= target
->make_symbol();
923 // This means that we don't want a symbol table
926 this->table_
.erase(ins
.first
);
929 this->table_
.erase(insdef
.first
);
930 // Inserting insdef invalidated ins.
931 this->table_
.erase(std::make_pair(name_key
,
938 ret
->init_object(name
, version
, object
, sym
, st_shndx
, is_ordinary
);
940 ins
.first
->second
= ret
;
943 // This is the first time we have seen NAME/NULL. Point
944 // it at the new entry for NAME/VERSION.
945 gold_assert(insdef
.second
);
946 insdef
.first
->second
= ret
;
951 // Record every time we see a new undefined symbol, to speed up
953 if (!was_undefined
&& ret
->is_undefined())
954 ++this->saw_undefined_
;
956 // Keep track of common symbols, to speed up common symbol
958 if (!was_common
&& ret
->is_common())
960 if (ret
->type() != elfcpp::STT_TLS
)
961 this->commons_
.push_back(ret
);
963 this->tls_commons_
.push_back(ret
);
966 // If we're not doing a relocatable link, then any symbol with
967 // hidden or internal visibility is local.
968 if ((ret
->visibility() == elfcpp::STV_HIDDEN
969 || ret
->visibility() == elfcpp::STV_INTERNAL
)
970 && (ret
->binding() == elfcpp::STB_GLOBAL
971 || ret
->binding() == elfcpp::STB_WEAK
)
972 && !parameters
->options().relocatable())
973 this->force_local(ret
);
976 ret
->set_is_default();
980 // Add all the symbols in a relocatable object to the hash table.
982 template<int size
, bool big_endian
>
984 Symbol_table::add_from_relobj(
985 Sized_relobj
<size
, big_endian
>* relobj
,
986 const unsigned char* syms
,
988 size_t symndx_offset
,
989 const char* sym_names
,
990 size_t sym_name_size
,
991 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
,
996 gold_assert(size
== relobj
->target()->get_size());
997 gold_assert(size
== parameters
->target().get_size());
999 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1001 const bool just_symbols
= relobj
->just_symbols();
1003 const unsigned char* p
= syms
;
1004 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
1006 (*sympointers
)[i
] = NULL
;
1008 elfcpp::Sym
<size
, big_endian
> sym(p
);
1010 unsigned int st_name
= sym
.get_st_name();
1011 if (st_name
>= sym_name_size
)
1013 relobj
->error(_("bad global symbol name offset %u at %zu"),
1018 const char* name
= sym_names
+ st_name
;
1021 unsigned int st_shndx
= relobj
->adjust_sym_shndx(i
+ symndx_offset
,
1024 unsigned int orig_st_shndx
= st_shndx
;
1026 orig_st_shndx
= elfcpp::SHN_UNDEF
;
1028 if (st_shndx
!= elfcpp::SHN_UNDEF
)
1031 // A symbol defined in a section which we are not including must
1032 // be treated as an undefined symbol.
1033 if (st_shndx
!= elfcpp::SHN_UNDEF
1035 && !relobj
->is_section_included(st_shndx
))
1036 st_shndx
= elfcpp::SHN_UNDEF
;
1038 // In an object file, an '@' in the name separates the symbol
1039 // name from the version name. If there are two '@' characters,
1040 // this is the default version.
1041 const char* ver
= strchr(name
, '@');
1042 Stringpool::Key ver_key
= 0;
1044 // DEF: is the version default? LOCAL: is the symbol forced local?
1050 // The symbol name is of the form foo@VERSION or foo@@VERSION
1051 namelen
= ver
- name
;
1058 ver
= this->namepool_
.add(ver
, true, &ver_key
);
1060 // We don't want to assign a version to an undefined symbol,
1061 // even if it is listed in the version script. FIXME: What
1062 // about a common symbol?
1065 namelen
= strlen(name
);
1066 if (!this->version_script_
.empty()
1067 && st_shndx
!= elfcpp::SHN_UNDEF
)
1069 // The symbol name did not have a version, but the
1070 // version script may assign a version anyway.
1071 std::string version
;
1072 if (this->version_script_
.get_symbol_version(name
, &version
))
1074 // The version can be empty if the version script is
1075 // only used to force some symbols to be local.
1076 if (!version
.empty())
1078 ver
= this->namepool_
.add_with_length(version
.c_str(),
1085 else if (this->version_script_
.symbol_is_local(name
))
1090 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
1091 unsigned char symbuf
[sym_size
];
1092 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
1095 memcpy(symbuf
, p
, sym_size
);
1096 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1097 if (orig_st_shndx
!= elfcpp::SHN_UNDEF
&& is_ordinary
)
1099 // Symbol values in object files are section relative.
1100 // This is normally what we want, but since here we are
1101 // converting the symbol to absolute we need to add the
1102 // section address. The section address in an object
1103 // file is normally zero, but people can use a linker
1104 // script to change it.
1105 sw
.put_st_value(sym
.get_st_value()
1106 + relobj
->section_address(orig_st_shndx
));
1108 st_shndx
= elfcpp::SHN_ABS
;
1109 is_ordinary
= false;
1113 Stringpool::Key name_key
;
1114 name
= this->namepool_
.add_with_length(name
, namelen
, true,
1117 Sized_symbol
<size
>* res
;
1118 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
1119 def
, *psym
, st_shndx
, is_ordinary
,
1122 // If building a shared library using garbage collection, do not
1123 // treat externally visible symbols as garbage.
1124 if (parameters
->options().gc_sections()
1125 && parameters
->options().shared())
1126 this->gc_mark_symbol_for_shlib(res
);
1129 this->force_local(res
);
1131 (*sympointers
)[i
] = res
;
1135 // Add a symbol from a plugin-claimed file.
1137 template<int size
, bool big_endian
>
1139 Symbol_table::add_from_pluginobj(
1140 Sized_pluginobj
<size
, big_endian
>* obj
,
1143 elfcpp::Sym
<size
, big_endian
>* sym
)
1145 unsigned int st_shndx
= sym
->get_st_shndx();
1147 Stringpool::Key ver_key
= 0;
1153 ver
= this->namepool_
.add(ver
, true, &ver_key
);
1155 // We don't want to assign a version to an undefined symbol,
1156 // even if it is listed in the version script. FIXME: What
1157 // about a common symbol?
1160 if (!this->version_script_
.empty()
1161 && st_shndx
!= elfcpp::SHN_UNDEF
)
1163 // The symbol name did not have a version, but the
1164 // version script may assign a version anyway.
1165 std::string version
;
1166 if (this->version_script_
.get_symbol_version(name
, &version
))
1168 // The version can be empty if the version script is
1169 // only used to force some symbols to be local.
1170 if (!version
.empty())
1172 ver
= this->namepool_
.add_with_length(version
.c_str(),
1179 else if (this->version_script_
.symbol_is_local(name
))
1184 Stringpool::Key name_key
;
1185 name
= this->namepool_
.add(name
, true, &name_key
);
1187 Sized_symbol
<size
>* res
;
1188 res
= this->add_from_object(obj
, name
, name_key
, ver
, ver_key
,
1189 def
, *sym
, st_shndx
, true, st_shndx
);
1192 this->force_local(res
);
1197 // Add all the symbols in a dynamic object to the hash table.
1199 template<int size
, bool big_endian
>
1201 Symbol_table::add_from_dynobj(
1202 Sized_dynobj
<size
, big_endian
>* dynobj
,
1203 const unsigned char* syms
,
1205 const char* sym_names
,
1206 size_t sym_name_size
,
1207 const unsigned char* versym
,
1209 const std::vector
<const char*>* version_map
,
1210 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
,
1215 gold_assert(size
== dynobj
->target()->get_size());
1216 gold_assert(size
== parameters
->target().get_size());
1218 if (dynobj
->just_symbols())
1220 gold_error(_("--just-symbols does not make sense with a shared object"));
1224 if (versym
!= NULL
&& versym_size
/ 2 < count
)
1226 dynobj
->error(_("too few symbol versions"));
1230 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1232 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1233 // weak aliases. This is necessary because if the dynamic object
1234 // provides the same variable under two names, one of which is a
1235 // weak definition, and the regular object refers to the weak
1236 // definition, we have to put both the weak definition and the
1237 // strong definition into the dynamic symbol table. Given a weak
1238 // definition, the only way that we can find the corresponding
1239 // strong definition, if any, is to search the symbol table.
1240 std::vector
<Sized_symbol
<size
>*> object_symbols
;
1242 const unsigned char* p
= syms
;
1243 const unsigned char* vs
= versym
;
1244 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
1246 elfcpp::Sym
<size
, big_endian
> sym(p
);
1248 if (sympointers
!= NULL
)
1249 (*sympointers
)[i
] = NULL
;
1251 // Ignore symbols with local binding or that have
1252 // internal or hidden visibility.
1253 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
1254 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
1255 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
1258 // A protected symbol in a shared library must be treated as a
1259 // normal symbol when viewed from outside the shared library.
1260 // Implement this by overriding the visibility here.
1261 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
1262 unsigned char symbuf
[sym_size
];
1263 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
1264 if (sym
.get_st_visibility() == elfcpp::STV_PROTECTED
)
1266 memcpy(symbuf
, p
, sym_size
);
1267 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
1268 sw
.put_st_other(elfcpp::STV_DEFAULT
, sym
.get_st_nonvis());
1272 unsigned int st_name
= psym
->get_st_name();
1273 if (st_name
>= sym_name_size
)
1275 dynobj
->error(_("bad symbol name offset %u at %zu"),
1280 const char* name
= sym_names
+ st_name
;
1283 unsigned int st_shndx
= dynobj
->adjust_sym_shndx(i
, psym
->get_st_shndx(),
1286 if (st_shndx
!= elfcpp::SHN_UNDEF
)
1289 Sized_symbol
<size
>* res
;
1293 Stringpool::Key name_key
;
1294 name
= this->namepool_
.add(name
, true, &name_key
);
1295 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1296 false, *psym
, st_shndx
, is_ordinary
,
1301 // Read the version information.
1303 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
1305 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
1306 v
&= elfcpp::VERSYM_VERSION
;
1308 // The Sun documentation says that V can be VER_NDX_LOCAL,
1309 // or VER_NDX_GLOBAL, or a version index. The meaning of
1310 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1311 // The old GNU linker will happily generate VER_NDX_LOCAL
1312 // for an undefined symbol. I don't know what the Sun
1313 // linker will generate.
1315 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
1316 && st_shndx
!= elfcpp::SHN_UNDEF
)
1318 // This symbol should not be visible outside the object.
1322 // At this point we are definitely going to add this symbol.
1323 Stringpool::Key name_key
;
1324 name
= this->namepool_
.add(name
, true, &name_key
);
1326 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
1327 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
1329 // This symbol does not have a version.
1330 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1331 false, *psym
, st_shndx
, is_ordinary
,
1336 if (v
>= version_map
->size())
1338 dynobj
->error(_("versym for symbol %zu out of range: %u"),
1343 const char* version
= (*version_map
)[v
];
1344 if (version
== NULL
)
1346 dynobj
->error(_("versym for symbol %zu has no name: %u"),
1351 Stringpool::Key version_key
;
1352 version
= this->namepool_
.add(version
, true, &version_key
);
1354 // If this is an absolute symbol, and the version name
1355 // and symbol name are the same, then this is the
1356 // version definition symbol. These symbols exist to
1357 // support using -u to pull in particular versions. We
1358 // do not want to record a version for them.
1359 if (st_shndx
== elfcpp::SHN_ABS
1361 && name_key
== version_key
)
1362 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1363 false, *psym
, st_shndx
, is_ordinary
,
1367 const bool def
= (!hidden
1368 && st_shndx
!= elfcpp::SHN_UNDEF
);
1369 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
1370 version_key
, def
, *psym
, st_shndx
,
1371 is_ordinary
, st_shndx
);
1376 // Note that it is possible that RES was overridden by an
1377 // earlier object, in which case it can't be aliased here.
1378 if (st_shndx
!= elfcpp::SHN_UNDEF
1380 && psym
->get_st_type() == elfcpp::STT_OBJECT
1381 && res
->source() == Symbol::FROM_OBJECT
1382 && res
->object() == dynobj
)
1383 object_symbols
.push_back(res
);
1385 if (sympointers
!= NULL
)
1386 (*sympointers
)[i
] = res
;
1389 this->record_weak_aliases(&object_symbols
);
1392 // This is used to sort weak aliases. We sort them first by section
1393 // index, then by offset, then by weak ahead of strong.
1396 class Weak_alias_sorter
1399 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
1404 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
1405 const Sized_symbol
<size
>* s2
) const
1408 unsigned int s1_shndx
= s1
->shndx(&is_ordinary
);
1409 gold_assert(is_ordinary
);
1410 unsigned int s2_shndx
= s2
->shndx(&is_ordinary
);
1411 gold_assert(is_ordinary
);
1412 if (s1_shndx
!= s2_shndx
)
1413 return s1_shndx
< s2_shndx
;
1415 if (s1
->value() != s2
->value())
1416 return s1
->value() < s2
->value();
1417 if (s1
->binding() != s2
->binding())
1419 if (s1
->binding() == elfcpp::STB_WEAK
)
1421 if (s2
->binding() == elfcpp::STB_WEAK
)
1424 return std::string(s1
->name()) < std::string(s2
->name());
1427 // SYMBOLS is a list of object symbols from a dynamic object. Look
1428 // for any weak aliases, and record them so that if we add the weak
1429 // alias to the dynamic symbol table, we also add the corresponding
1434 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
1436 // Sort the vector by section index, then by offset, then by weak
1438 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
1440 // Walk through the vector. For each weak definition, record
1442 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
1444 p
!= symbols
->end();
1447 if ((*p
)->binding() != elfcpp::STB_WEAK
)
1450 // Build a circular list of weak aliases. Each symbol points to
1451 // the next one in the circular list.
1453 Sized_symbol
<size
>* from_sym
= *p
;
1454 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
1455 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
1458 if ((*q
)->shndx(&dummy
) != from_sym
->shndx(&dummy
)
1459 || (*q
)->value() != from_sym
->value())
1462 this->weak_aliases_
[from_sym
] = *q
;
1463 from_sym
->set_has_alias();
1469 this->weak_aliases_
[from_sym
] = *p
;
1470 from_sym
->set_has_alias();
1477 // Create and return a specially defined symbol. If ONLY_IF_REF is
1478 // true, then only create the symbol if there is a reference to it.
1479 // If this does not return NULL, it sets *POLDSYM to the existing
1480 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1482 template<int size
, bool big_endian
>
1484 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1486 Sized_symbol
<size
>** poldsym
)
1489 Sized_symbol
<size
>* sym
;
1490 bool add_to_table
= false;
1491 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1493 // If the caller didn't give us a version, see if we get one from
1494 // the version script.
1496 if (*pversion
== NULL
)
1498 if (this->version_script_
.get_symbol_version(*pname
, &v
))
1501 *pversion
= v
.c_str();
1507 oldsym
= this->lookup(*pname
, *pversion
);
1508 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1511 *pname
= oldsym
->name();
1512 *pversion
= oldsym
->version();
1516 // Canonicalize NAME and VERSION.
1517 Stringpool::Key name_key
;
1518 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1520 Stringpool::Key version_key
= 0;
1521 if (*pversion
!= NULL
)
1522 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1524 Symbol
* const snull
= NULL
;
1525 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1526 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1532 // We already have a symbol table entry for NAME/VERSION.
1533 oldsym
= ins
.first
->second
;
1534 gold_assert(oldsym
!= NULL
);
1538 // We haven't seen this symbol before.
1539 gold_assert(ins
.first
->second
== NULL
);
1540 add_to_table
= true;
1541 add_loc
= ins
.first
;
1546 const Target
& target
= parameters
->target();
1547 if (!target
.has_make_symbol())
1548 sym
= new Sized_symbol
<size
>();
1551 gold_assert(target
.get_size() == size
);
1552 gold_assert(target
.is_big_endian() ? big_endian
: !big_endian
);
1553 typedef Sized_target
<size
, big_endian
> My_target
;
1554 const My_target
* sized_target
=
1555 static_cast<const My_target
*>(&target
);
1556 sym
= sized_target
->make_symbol();
1562 add_loc
->second
= sym
;
1564 gold_assert(oldsym
!= NULL
);
1566 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1571 // Define a symbol based on an Output_data.
1574 Symbol_table::define_in_output_data(const char* name
,
1575 const char* version
,
1580 elfcpp::STB binding
,
1581 elfcpp::STV visibility
,
1582 unsigned char nonvis
,
1583 bool offset_is_from_end
,
1586 if (parameters
->target().get_size() == 32)
1588 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1589 return this->do_define_in_output_data
<32>(name
, version
, od
,
1590 value
, symsize
, type
, binding
,
1598 else if (parameters
->target().get_size() == 64)
1600 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1601 return this->do_define_in_output_data
<64>(name
, version
, od
,
1602 value
, symsize
, type
, binding
,
1614 // Define a symbol in an Output_data, sized version.
1618 Symbol_table::do_define_in_output_data(
1620 const char* version
,
1622 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1623 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1625 elfcpp::STB binding
,
1626 elfcpp::STV visibility
,
1627 unsigned char nonvis
,
1628 bool offset_is_from_end
,
1631 Sized_symbol
<size
>* sym
;
1632 Sized_symbol
<size
>* oldsym
;
1634 if (parameters
->target().is_big_endian())
1636 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1637 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1638 only_if_ref
, &oldsym
);
1645 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1646 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1647 only_if_ref
, &oldsym
);
1656 sym
->init_output_data(name
, version
, od
, value
, symsize
, type
, binding
,
1657 visibility
, nonvis
, offset_is_from_end
);
1661 if (binding
== elfcpp::STB_LOCAL
1662 || this->version_script_
.symbol_is_local(name
))
1663 this->force_local(sym
);
1664 else if (version
!= NULL
)
1665 sym
->set_is_default();
1669 if (Symbol_table::should_override_with_special(oldsym
))
1670 this->override_with_special(oldsym
, sym
);
1675 // Define a symbol based on an Output_segment.
1678 Symbol_table::define_in_output_segment(const char* name
,
1679 const char* version
, Output_segment
* os
,
1683 elfcpp::STB binding
,
1684 elfcpp::STV visibility
,
1685 unsigned char nonvis
,
1686 Symbol::Segment_offset_base offset_base
,
1689 if (parameters
->target().get_size() == 32)
1691 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1692 return this->do_define_in_output_segment
<32>(name
, version
, os
,
1693 value
, symsize
, type
,
1694 binding
, visibility
, nonvis
,
1695 offset_base
, only_if_ref
);
1700 else if (parameters
->target().get_size() == 64)
1702 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1703 return this->do_define_in_output_segment
<64>(name
, version
, os
,
1704 value
, symsize
, type
,
1705 binding
, visibility
, nonvis
,
1706 offset_base
, only_if_ref
);
1715 // Define a symbol in an Output_segment, sized version.
1719 Symbol_table::do_define_in_output_segment(
1721 const char* version
,
1723 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1724 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1726 elfcpp::STB binding
,
1727 elfcpp::STV visibility
,
1728 unsigned char nonvis
,
1729 Symbol::Segment_offset_base offset_base
,
1732 Sized_symbol
<size
>* sym
;
1733 Sized_symbol
<size
>* oldsym
;
1735 if (parameters
->target().is_big_endian())
1737 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1738 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1739 only_if_ref
, &oldsym
);
1746 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1747 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1748 only_if_ref
, &oldsym
);
1757 sym
->init_output_segment(name
, version
, os
, value
, symsize
, type
, binding
,
1758 visibility
, nonvis
, offset_base
);
1762 if (binding
== elfcpp::STB_LOCAL
1763 || this->version_script_
.symbol_is_local(name
))
1764 this->force_local(sym
);
1765 else if (version
!= NULL
)
1766 sym
->set_is_default();
1770 if (Symbol_table::should_override_with_special(oldsym
))
1771 this->override_with_special(oldsym
, sym
);
1776 // Define a special symbol with a constant value. It is a multiple
1777 // definition error if this symbol is already defined.
1780 Symbol_table::define_as_constant(const char* name
,
1781 const char* version
,
1785 elfcpp::STB binding
,
1786 elfcpp::STV visibility
,
1787 unsigned char nonvis
,
1789 bool force_override
)
1791 if (parameters
->target().get_size() == 32)
1793 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1794 return this->do_define_as_constant
<32>(name
, version
, value
,
1795 symsize
, type
, binding
,
1796 visibility
, nonvis
, only_if_ref
,
1802 else if (parameters
->target().get_size() == 64)
1804 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1805 return this->do_define_as_constant
<64>(name
, version
, value
,
1806 symsize
, type
, binding
,
1807 visibility
, nonvis
, only_if_ref
,
1817 // Define a symbol as a constant, sized version.
1821 Symbol_table::do_define_as_constant(
1823 const char* version
,
1824 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1825 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1827 elfcpp::STB binding
,
1828 elfcpp::STV visibility
,
1829 unsigned char nonvis
,
1831 bool force_override
)
1833 Sized_symbol
<size
>* sym
;
1834 Sized_symbol
<size
>* oldsym
;
1836 if (parameters
->target().is_big_endian())
1838 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1839 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1840 only_if_ref
, &oldsym
);
1847 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1848 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1849 only_if_ref
, &oldsym
);
1858 sym
->init_constant(name
, version
, value
, symsize
, type
, binding
, visibility
,
1863 // Version symbols are absolute symbols with name == version.
1864 // We don't want to force them to be local.
1865 if ((version
== NULL
1868 && (binding
== elfcpp::STB_LOCAL
1869 || this->version_script_
.symbol_is_local(name
)))
1870 this->force_local(sym
);
1871 else if (version
!= NULL
1872 && (name
!= version
|| value
!= 0))
1873 sym
->set_is_default();
1877 if (force_override
|| Symbol_table::should_override_with_special(oldsym
))
1878 this->override_with_special(oldsym
, sym
);
1883 // Define a set of symbols in output sections.
1886 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1887 const Define_symbol_in_section
* p
,
1890 for (int i
= 0; i
< count
; ++i
, ++p
)
1892 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1894 this->define_in_output_data(p
->name
, NULL
, os
, p
->value
,
1895 p
->size
, p
->type
, p
->binding
,
1896 p
->visibility
, p
->nonvis
,
1897 p
->offset_is_from_end
,
1898 only_if_ref
|| p
->only_if_ref
);
1900 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1901 p
->binding
, p
->visibility
, p
->nonvis
,
1902 only_if_ref
|| p
->only_if_ref
,
1907 // Define a set of symbols in output segments.
1910 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1911 const Define_symbol_in_segment
* p
,
1914 for (int i
= 0; i
< count
; ++i
, ++p
)
1916 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1917 p
->segment_flags_set
,
1918 p
->segment_flags_clear
);
1920 this->define_in_output_segment(p
->name
, NULL
, os
, p
->value
,
1921 p
->size
, p
->type
, p
->binding
,
1922 p
->visibility
, p
->nonvis
,
1924 only_if_ref
|| p
->only_if_ref
);
1926 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1927 p
->binding
, p
->visibility
, p
->nonvis
,
1928 only_if_ref
|| p
->only_if_ref
,
1933 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1934 // symbol should be defined--typically a .dyn.bss section. VALUE is
1935 // the offset within POSD.
1939 Symbol_table::define_with_copy_reloc(
1940 Sized_symbol
<size
>* csym
,
1942 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1944 gold_assert(csym
->is_from_dynobj());
1945 gold_assert(!csym
->is_copied_from_dynobj());
1946 Object
* object
= csym
->object();
1947 gold_assert(object
->is_dynamic());
1948 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1950 // Our copied variable has to override any variable in a shared
1952 elfcpp::STB binding
= csym
->binding();
1953 if (binding
== elfcpp::STB_WEAK
)
1954 binding
= elfcpp::STB_GLOBAL
;
1956 this->define_in_output_data(csym
->name(), csym
->version(),
1957 posd
, value
, csym
->symsize(),
1958 csym
->type(), binding
,
1959 csym
->visibility(), csym
->nonvis(),
1962 csym
->set_is_copied_from_dynobj();
1963 csym
->set_needs_dynsym_entry();
1965 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1967 // We have now defined all aliases, but we have not entered them all
1968 // in the copied_symbol_dynobjs_ map.
1969 if (csym
->has_alias())
1974 sym
= this->weak_aliases_
[sym
];
1977 gold_assert(sym
->output_data() == posd
);
1979 sym
->set_is_copied_from_dynobj();
1980 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1985 // SYM is defined using a COPY reloc. Return the dynamic object where
1986 // the original definition was found.
1989 Symbol_table::get_copy_source(const Symbol
* sym
) const
1991 gold_assert(sym
->is_copied_from_dynobj());
1992 Copied_symbol_dynobjs::const_iterator p
=
1993 this->copied_symbol_dynobjs_
.find(sym
);
1994 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1998 // Add any undefined symbols named on the command line.
2001 Symbol_table::add_undefined_symbols_from_command_line()
2003 if (parameters
->options().any_undefined())
2005 if (parameters
->target().get_size() == 32)
2007 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2008 this->do_add_undefined_symbols_from_command_line
<32>();
2013 else if (parameters
->target().get_size() == 64)
2015 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2016 this->do_add_undefined_symbols_from_command_line
<64>();
2028 Symbol_table::do_add_undefined_symbols_from_command_line()
2030 for (options::String_set::const_iterator p
=
2031 parameters
->options().undefined_begin();
2032 p
!= parameters
->options().undefined_end();
2035 const char* name
= p
->c_str();
2037 if (this->lookup(name
) != NULL
)
2040 const char* version
= NULL
;
2042 Sized_symbol
<size
>* sym
;
2043 Sized_symbol
<size
>* oldsym
;
2044 if (parameters
->target().is_big_endian())
2046 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2047 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
2055 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2056 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
2063 gold_assert(oldsym
== NULL
);
2065 sym
->init_undefined(name
, version
, elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
2066 elfcpp::STV_DEFAULT
, 0);
2067 ++this->saw_undefined_
;
2071 // Set the dynamic symbol indexes. INDEX is the index of the first
2072 // global dynamic symbol. Pointers to the symbols are stored into the
2073 // vector SYMS. The names are added to DYNPOOL. This returns an
2074 // updated dynamic symbol index.
2077 Symbol_table::set_dynsym_indexes(unsigned int index
,
2078 std::vector
<Symbol
*>* syms
,
2079 Stringpool
* dynpool
,
2082 for (Symbol_table_type::iterator p
= this->table_
.begin();
2083 p
!= this->table_
.end();
2086 Symbol
* sym
= p
->second
;
2088 // Note that SYM may already have a dynamic symbol index, since
2089 // some symbols appear more than once in the symbol table, with
2090 // and without a version.
2092 if (!sym
->should_add_dynsym_entry())
2093 sym
->set_dynsym_index(-1U);
2094 else if (!sym
->has_dynsym_index())
2096 sym
->set_dynsym_index(index
);
2098 syms
->push_back(sym
);
2099 dynpool
->add(sym
->name(), false, NULL
);
2101 // Record any version information.
2102 if (sym
->version() != NULL
)
2103 versions
->record_version(this, dynpool
, sym
);
2107 // Finish up the versions. In some cases this may add new dynamic
2109 index
= versions
->finalize(this, index
, syms
);
2114 // Set the final values for all the symbols. The index of the first
2115 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2116 // file offset OFF. Add their names to POOL. Return the new file
2117 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2120 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
2121 size_t dyncount
, Stringpool
* pool
,
2122 unsigned int *plocal_symcount
)
2126 gold_assert(*plocal_symcount
!= 0);
2127 this->first_global_index_
= *plocal_symcount
;
2129 this->dynamic_offset_
= dynoff
;
2130 this->first_dynamic_global_index_
= dyn_global_index
;
2131 this->dynamic_count_
= dyncount
;
2133 if (parameters
->target().get_size() == 32)
2135 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2136 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
2141 else if (parameters
->target().get_size() == 64)
2143 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2144 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
2152 // Now that we have the final symbol table, we can reliably note
2153 // which symbols should get warnings.
2154 this->warnings_
.note_warnings(this);
2159 // SYM is going into the symbol table at *PINDEX. Add the name to
2160 // POOL, update *PINDEX and *POFF.
2164 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
2165 unsigned int* pindex
, off_t
* poff
)
2167 sym
->set_symtab_index(*pindex
);
2168 pool
->add(sym
->name(), false, NULL
);
2170 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
2173 // Set the final value for all the symbols. This is called after
2174 // Layout::finalize, so all the output sections have their final
2179 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
2180 unsigned int* plocal_symcount
)
2182 off
= align_address(off
, size
>> 3);
2183 this->offset_
= off
;
2185 unsigned int index
= *plocal_symcount
;
2186 const unsigned int orig_index
= index
;
2188 // First do all the symbols which have been forced to be local, as
2189 // they must appear before all global symbols.
2190 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
2191 p
!= this->forced_locals_
.end();
2195 gold_assert(sym
->is_forced_local());
2196 if (this->sized_finalize_symbol
<size
>(sym
))
2198 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
2203 // Now do all the remaining symbols.
2204 for (Symbol_table_type::iterator p
= this->table_
.begin();
2205 p
!= this->table_
.end();
2208 Symbol
* sym
= p
->second
;
2209 if (this->sized_finalize_symbol
<size
>(sym
))
2210 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
2213 this->output_count_
= index
- orig_index
;
2218 // Finalize the symbol SYM. This returns true if the symbol should be
2219 // added to the symbol table, false otherwise.
2223 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
2225 typedef typename Sized_symbol
<size
>::Value_type Value_type
;
2227 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
2229 // The default version of a symbol may appear twice in the symbol
2230 // table. We only need to finalize it once.
2231 if (sym
->has_symtab_index())
2236 gold_assert(!sym
->has_symtab_index());
2237 sym
->set_symtab_index(-1U);
2238 gold_assert(sym
->dynsym_index() == -1U);
2244 switch (sym
->source())
2246 case Symbol::FROM_OBJECT
:
2249 unsigned int shndx
= sym
->shndx(&is_ordinary
);
2251 // FIXME: We need some target specific support here.
2253 && shndx
!= elfcpp::SHN_ABS
2254 && shndx
!= elfcpp::SHN_COMMON
)
2256 gold_error(_("%s: unsupported symbol section 0x%x"),
2257 sym
->demangled_name().c_str(), shndx
);
2258 shndx
= elfcpp::SHN_UNDEF
;
2261 Object
* symobj
= sym
->object();
2262 if (symobj
->is_dynamic())
2265 shndx
= elfcpp::SHN_UNDEF
;
2267 else if (symobj
->pluginobj() != NULL
)
2270 shndx
= elfcpp::SHN_UNDEF
;
2272 else if (shndx
== elfcpp::SHN_UNDEF
)
2274 else if (!is_ordinary
2275 && (shndx
== elfcpp::SHN_ABS
|| shndx
== elfcpp::SHN_COMMON
))
2276 value
= sym
->value();
2279 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
2280 Output_section
* os
= relobj
->output_section(shndx
);
2284 sym
->set_symtab_index(-1U);
2285 bool static_or_reloc
= (parameters
->doing_static_link() ||
2286 parameters
->options().relocatable());
2287 gold_assert(static_or_reloc
|| sym
->dynsym_index() == -1U);
2292 uint64_t secoff64
= relobj
->output_section_offset(shndx
);
2293 if (secoff64
== -1ULL)
2295 // The section needs special handling (e.g., a merge section).
2296 value
= os
->output_address(relobj
, shndx
, sym
->value());
2301 convert_types
<Value_type
, uint64_t>(secoff64
);
2302 if (sym
->type() == elfcpp::STT_TLS
)
2303 value
= sym
->value() + os
->tls_offset() + secoff
;
2305 value
= sym
->value() + os
->address() + secoff
;
2311 case Symbol::IN_OUTPUT_DATA
:
2313 Output_data
* od
= sym
->output_data();
2314 value
= sym
->value();
2315 if (sym
->type() != elfcpp::STT_TLS
)
2316 value
+= od
->address();
2319 Output_section
* os
= od
->output_section();
2320 gold_assert(os
!= NULL
);
2321 value
+= os
->tls_offset() + (od
->address() - os
->address());
2323 if (sym
->offset_is_from_end())
2324 value
+= od
->data_size();
2328 case Symbol::IN_OUTPUT_SEGMENT
:
2330 Output_segment
* os
= sym
->output_segment();
2331 value
= sym
->value();
2332 if (sym
->type() != elfcpp::STT_TLS
)
2333 value
+= os
->vaddr();
2334 switch (sym
->offset_base())
2336 case Symbol::SEGMENT_START
:
2338 case Symbol::SEGMENT_END
:
2339 value
+= os
->memsz();
2341 case Symbol::SEGMENT_BSS
:
2342 value
+= os
->filesz();
2350 case Symbol::IS_CONSTANT
:
2351 value
= sym
->value();
2354 case Symbol::IS_UNDEFINED
:
2362 sym
->set_value(value
);
2364 if (parameters
->options().strip_all())
2366 sym
->set_symtab_index(-1U);
2373 // Write out the global symbols.
2376 Symbol_table::write_globals(const Input_objects
* input_objects
,
2377 const Stringpool
* sympool
,
2378 const Stringpool
* dynpool
,
2379 Output_symtab_xindex
* symtab_xindex
,
2380 Output_symtab_xindex
* dynsym_xindex
,
2381 Output_file
* of
) const
2383 switch (parameters
->size_and_endianness())
2385 #ifdef HAVE_TARGET_32_LITTLE
2386 case Parameters::TARGET_32_LITTLE
:
2387 this->sized_write_globals
<32, false>(input_objects
, sympool
,
2388 dynpool
, symtab_xindex
,
2392 #ifdef HAVE_TARGET_32_BIG
2393 case Parameters::TARGET_32_BIG
:
2394 this->sized_write_globals
<32, true>(input_objects
, sympool
,
2395 dynpool
, symtab_xindex
,
2399 #ifdef HAVE_TARGET_64_LITTLE
2400 case Parameters::TARGET_64_LITTLE
:
2401 this->sized_write_globals
<64, false>(input_objects
, sympool
,
2402 dynpool
, symtab_xindex
,
2406 #ifdef HAVE_TARGET_64_BIG
2407 case Parameters::TARGET_64_BIG
:
2408 this->sized_write_globals
<64, true>(input_objects
, sympool
,
2409 dynpool
, symtab_xindex
,
2418 // Write out the global symbols.
2420 template<int size
, bool big_endian
>
2422 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
2423 const Stringpool
* sympool
,
2424 const Stringpool
* dynpool
,
2425 Output_symtab_xindex
* symtab_xindex
,
2426 Output_symtab_xindex
* dynsym_xindex
,
2427 Output_file
* of
) const
2429 const Target
& target
= parameters
->target();
2431 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2433 const unsigned int output_count
= this->output_count_
;
2434 const section_size_type oview_size
= output_count
* sym_size
;
2435 const unsigned int first_global_index
= this->first_global_index_
;
2436 unsigned char* psyms
;
2437 if (this->offset_
== 0 || output_count
== 0)
2440 psyms
= of
->get_output_view(this->offset_
, oview_size
);
2442 const unsigned int dynamic_count
= this->dynamic_count_
;
2443 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
2444 const unsigned int first_dynamic_global_index
=
2445 this->first_dynamic_global_index_
;
2446 unsigned char* dynamic_view
;
2447 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
2448 dynamic_view
= NULL
;
2450 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
2452 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
2453 p
!= this->table_
.end();
2456 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
2458 // Possibly warn about unresolved symbols in shared libraries.
2459 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
2461 unsigned int sym_index
= sym
->symtab_index();
2462 unsigned int dynsym_index
;
2463 if (dynamic_view
== NULL
)
2466 dynsym_index
= sym
->dynsym_index();
2468 if (sym_index
== -1U && dynsym_index
== -1U)
2470 // This symbol is not included in the output file.
2475 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
2476 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
2477 switch (sym
->source())
2479 case Symbol::FROM_OBJECT
:
2482 unsigned int in_shndx
= sym
->shndx(&is_ordinary
);
2484 // FIXME: We need some target specific support here.
2486 && in_shndx
!= elfcpp::SHN_ABS
2487 && in_shndx
!= elfcpp::SHN_COMMON
)
2489 gold_error(_("%s: unsupported symbol section 0x%x"),
2490 sym
->demangled_name().c_str(), in_shndx
);
2495 Object
* symobj
= sym
->object();
2496 if (symobj
->is_dynamic())
2498 if (sym
->needs_dynsym_value())
2499 dynsym_value
= target
.dynsym_value(sym
);
2500 shndx
= elfcpp::SHN_UNDEF
;
2502 else if (symobj
->pluginobj() != NULL
)
2503 shndx
= elfcpp::SHN_UNDEF
;
2504 else if (in_shndx
== elfcpp::SHN_UNDEF
2506 && (in_shndx
== elfcpp::SHN_ABS
2507 || in_shndx
== elfcpp::SHN_COMMON
)))
2511 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
2512 Output_section
* os
= relobj
->output_section(in_shndx
);
2513 gold_assert(os
!= NULL
);
2514 shndx
= os
->out_shndx();
2516 if (shndx
>= elfcpp::SHN_LORESERVE
)
2518 if (sym_index
!= -1U)
2519 symtab_xindex
->add(sym_index
, shndx
);
2520 if (dynsym_index
!= -1U)
2521 dynsym_xindex
->add(dynsym_index
, shndx
);
2522 shndx
= elfcpp::SHN_XINDEX
;
2525 // In object files symbol values are section
2527 if (parameters
->options().relocatable())
2528 sym_value
-= os
->address();
2534 case Symbol::IN_OUTPUT_DATA
:
2535 shndx
= sym
->output_data()->out_shndx();
2536 if (shndx
>= elfcpp::SHN_LORESERVE
)
2538 if (sym_index
!= -1U)
2539 symtab_xindex
->add(sym_index
, shndx
);
2540 if (dynsym_index
!= -1U)
2541 dynsym_xindex
->add(dynsym_index
, shndx
);
2542 shndx
= elfcpp::SHN_XINDEX
;
2546 case Symbol::IN_OUTPUT_SEGMENT
:
2547 shndx
= elfcpp::SHN_ABS
;
2550 case Symbol::IS_CONSTANT
:
2551 shndx
= elfcpp::SHN_ABS
;
2554 case Symbol::IS_UNDEFINED
:
2555 shndx
= elfcpp::SHN_UNDEF
;
2562 if (sym_index
!= -1U)
2564 sym_index
-= first_global_index
;
2565 gold_assert(sym_index
< output_count
);
2566 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
2567 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
2571 if (dynsym_index
!= -1U)
2573 dynsym_index
-= first_dynamic_global_index
;
2574 gold_assert(dynsym_index
< dynamic_count
);
2575 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
2576 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
2581 of
->write_output_view(this->offset_
, oview_size
, psyms
);
2582 if (dynamic_view
!= NULL
)
2583 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
2586 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2587 // strtab holding the name.
2589 template<int size
, bool big_endian
>
2591 Symbol_table::sized_write_symbol(
2592 Sized_symbol
<size
>* sym
,
2593 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
2595 const Stringpool
* pool
,
2596 unsigned char* p
) const
2598 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
2599 osym
.put_st_name(pool
->get_offset(sym
->name()));
2600 osym
.put_st_value(value
);
2601 // Use a symbol size of zero for undefined symbols from shared libraries.
2602 if (shndx
== elfcpp::SHN_UNDEF
&& sym
->is_from_dynobj())
2603 osym
.put_st_size(0);
2605 osym
.put_st_size(sym
->symsize());
2606 // A version script may have overridden the default binding.
2607 if (sym
->is_forced_local())
2608 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, sym
->type()));
2610 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
2611 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
2612 osym
.put_st_shndx(shndx
);
2615 // Check for unresolved symbols in shared libraries. This is
2616 // controlled by the --allow-shlib-undefined option.
2618 // We only warn about libraries for which we have seen all the
2619 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2620 // which were not seen in this link. If we didn't see a DT_NEEDED
2621 // entry, we aren't going to be able to reliably report whether the
2622 // symbol is undefined.
2624 // We also don't warn about libraries found in the system library
2625 // directory (the directory were we find libc.so); we assume that
2626 // those libraries are OK. This heuristic avoids problems in
2627 // GNU/Linux, in which -ldl can have undefined references satisfied by
2631 Symbol_table::warn_about_undefined_dynobj_symbol(
2632 const Input_objects
* input_objects
,
2636 if (sym
->source() == Symbol::FROM_OBJECT
2637 && sym
->object()->is_dynamic()
2638 && sym
->shndx(&dummy
) == elfcpp::SHN_UNDEF
2639 && sym
->binding() != elfcpp::STB_WEAK
2640 && !parameters
->options().allow_shlib_undefined()
2641 && !parameters
->target().is_defined_by_abi(sym
)
2642 && !input_objects
->found_in_system_library_directory(sym
->object()))
2644 // A very ugly cast.
2645 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
2646 if (!dynobj
->has_unknown_needed_entries())
2647 gold_undefined_symbol(sym
);
2651 // Write out a section symbol. Return the update offset.
2654 Symbol_table::write_section_symbol(const Output_section
*os
,
2655 Output_symtab_xindex
* symtab_xindex
,
2659 switch (parameters
->size_and_endianness())
2661 #ifdef HAVE_TARGET_32_LITTLE
2662 case Parameters::TARGET_32_LITTLE
:
2663 this->sized_write_section_symbol
<32, false>(os
, symtab_xindex
, of
,
2667 #ifdef HAVE_TARGET_32_BIG
2668 case Parameters::TARGET_32_BIG
:
2669 this->sized_write_section_symbol
<32, true>(os
, symtab_xindex
, of
,
2673 #ifdef HAVE_TARGET_64_LITTLE
2674 case Parameters::TARGET_64_LITTLE
:
2675 this->sized_write_section_symbol
<64, false>(os
, symtab_xindex
, of
,
2679 #ifdef HAVE_TARGET_64_BIG
2680 case Parameters::TARGET_64_BIG
:
2681 this->sized_write_section_symbol
<64, true>(os
, symtab_xindex
, of
,
2690 // Write out a section symbol, specialized for size and endianness.
2692 template<int size
, bool big_endian
>
2694 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
2695 Output_symtab_xindex
* symtab_xindex
,
2699 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2701 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
2703 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
2704 osym
.put_st_name(0);
2705 osym
.put_st_value(os
->address());
2706 osym
.put_st_size(0);
2707 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
2708 elfcpp::STT_SECTION
));
2709 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
2711 unsigned int shndx
= os
->out_shndx();
2712 if (shndx
>= elfcpp::SHN_LORESERVE
)
2714 symtab_xindex
->add(os
->symtab_index(), shndx
);
2715 shndx
= elfcpp::SHN_XINDEX
;
2717 osym
.put_st_shndx(shndx
);
2719 of
->write_output_view(offset
, sym_size
, pov
);
2722 // Print statistical information to stderr. This is used for --stats.
2725 Symbol_table::print_stats() const
2727 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2728 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2729 program_name
, this->table_
.size(), this->table_
.bucket_count());
2731 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
2732 program_name
, this->table_
.size());
2734 this->namepool_
.print_stats("symbol table stringpool");
2737 // We check for ODR violations by looking for symbols with the same
2738 // name for which the debugging information reports that they were
2739 // defined in different source locations. When comparing the source
2740 // location, we consider instances with the same base filename and
2741 // line number to be the same. This is because different object
2742 // files/shared libraries can include the same header file using
2743 // different paths, and we don't want to report an ODR violation in
2746 // This struct is used to compare line information, as returned by
2747 // Dwarf_line_info::one_addr2line. It implements a < comparison
2748 // operator used with std::set.
2750 struct Odr_violation_compare
2753 operator()(const std::string
& s1
, const std::string
& s2
) const
2755 std::string::size_type pos1
= s1
.rfind('/');
2756 std::string::size_type pos2
= s2
.rfind('/');
2757 if (pos1
== std::string::npos
2758 || pos2
== std::string::npos
)
2760 return s1
.compare(pos1
, std::string::npos
,
2761 s2
, pos2
, std::string::npos
) < 0;
2765 // Check candidate_odr_violations_ to find symbols with the same name
2766 // but apparently different definitions (different source-file/line-no).
2769 Symbol_table::detect_odr_violations(const Task
* task
,
2770 const char* output_file_name
) const
2772 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
2773 it
!= candidate_odr_violations_
.end();
2776 const char* symbol_name
= it
->first
;
2777 // We use a sorted set so the output is deterministic.
2778 std::set
<std::string
, Odr_violation_compare
> line_nums
;
2780 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
2781 locs
= it
->second
.begin();
2782 locs
!= it
->second
.end();
2785 // We need to lock the object in order to read it. This
2786 // means that we have to run in a singleton Task. If we
2787 // want to run this in a general Task for better
2788 // performance, we will need one Task for object, plus
2789 // appropriate locking to ensure that we don't conflict with
2790 // other uses of the object. Also note, one_addr2line is not
2791 // currently thread-safe.
2792 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2793 // 16 is the size of the object-cache that one_addr2line should use.
2794 std::string lineno
= Dwarf_line_info::one_addr2line(
2795 locs
->object
, locs
->shndx
, locs
->offset
, 16);
2796 if (!lineno
.empty())
2797 line_nums
.insert(lineno
);
2800 if (line_nums
.size() > 1)
2802 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2803 "places (possible ODR violation):"),
2804 output_file_name
, demangle(symbol_name
).c_str());
2805 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2806 it2
!= line_nums
.end();
2808 fprintf(stderr
, " %s\n", it2
->c_str());
2811 // We only call one_addr2line() in this function, so we can clear its cache.
2812 Dwarf_line_info::clear_addr2line_cache();
2815 // Warnings functions.
2817 // Add a new warning.
2820 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2821 const std::string
& warning
)
2823 name
= symtab
->canonicalize_name(name
);
2824 this->warnings_
[name
].set(obj
, warning
);
2827 // Look through the warnings and mark the symbols for which we should
2828 // warn. This is called during Layout::finalize when we know the
2829 // sources for all the symbols.
2832 Warnings::note_warnings(Symbol_table
* symtab
)
2834 for (Warning_table::iterator p
= this->warnings_
.begin();
2835 p
!= this->warnings_
.end();
2838 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2840 && sym
->source() == Symbol::FROM_OBJECT
2841 && sym
->object() == p
->second
.object
)
2842 sym
->set_has_warning();
2846 // Issue a warning. This is called when we see a relocation against a
2847 // symbol for which has a warning.
2849 template<int size
, bool big_endian
>
2851 Warnings::issue_warning(const Symbol
* sym
,
2852 const Relocate_info
<size
, big_endian
>* relinfo
,
2853 size_t relnum
, off_t reloffset
) const
2855 gold_assert(sym
->has_warning());
2856 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2857 gold_assert(p
!= this->warnings_
.end());
2858 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2859 "%s", p
->second
.text
.c_str());
2862 // Instantiate the templates we need. We could use the configure
2863 // script to restrict this to only the ones needed for implemented
2866 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2869 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2872 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2875 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2878 #ifdef HAVE_TARGET_32_LITTLE
2881 Symbol_table::add_from_relobj
<32, false>(
2882 Sized_relobj
<32, false>* relobj
,
2883 const unsigned char* syms
,
2885 size_t symndx_offset
,
2886 const char* sym_names
,
2887 size_t sym_name_size
,
2888 Sized_relobj
<32, false>::Symbols
* sympointers
,
2892 #ifdef HAVE_TARGET_32_BIG
2895 Symbol_table::add_from_relobj
<32, true>(
2896 Sized_relobj
<32, true>* relobj
,
2897 const unsigned char* syms
,
2899 size_t symndx_offset
,
2900 const char* sym_names
,
2901 size_t sym_name_size
,
2902 Sized_relobj
<32, true>::Symbols
* sympointers
,
2906 #ifdef HAVE_TARGET_64_LITTLE
2909 Symbol_table::add_from_relobj
<64, false>(
2910 Sized_relobj
<64, false>* relobj
,
2911 const unsigned char* syms
,
2913 size_t symndx_offset
,
2914 const char* sym_names
,
2915 size_t sym_name_size
,
2916 Sized_relobj
<64, false>::Symbols
* sympointers
,
2920 #ifdef HAVE_TARGET_64_BIG
2923 Symbol_table::add_from_relobj
<64, true>(
2924 Sized_relobj
<64, true>* relobj
,
2925 const unsigned char* syms
,
2927 size_t symndx_offset
,
2928 const char* sym_names
,
2929 size_t sym_name_size
,
2930 Sized_relobj
<64, true>::Symbols
* sympointers
,
2934 #ifdef HAVE_TARGET_32_LITTLE
2937 Symbol_table::add_from_pluginobj
<32, false>(
2938 Sized_pluginobj
<32, false>* obj
,
2941 elfcpp::Sym
<32, false>* sym
);
2944 #ifdef HAVE_TARGET_32_BIG
2947 Symbol_table::add_from_pluginobj
<32, true>(
2948 Sized_pluginobj
<32, true>* obj
,
2951 elfcpp::Sym
<32, true>* sym
);
2954 #ifdef HAVE_TARGET_64_LITTLE
2957 Symbol_table::add_from_pluginobj
<64, false>(
2958 Sized_pluginobj
<64, false>* obj
,
2961 elfcpp::Sym
<64, false>* sym
);
2964 #ifdef HAVE_TARGET_64_BIG
2967 Symbol_table::add_from_pluginobj
<64, true>(
2968 Sized_pluginobj
<64, true>* obj
,
2971 elfcpp::Sym
<64, true>* sym
);
2974 #ifdef HAVE_TARGET_32_LITTLE
2977 Symbol_table::add_from_dynobj
<32, false>(
2978 Sized_dynobj
<32, false>* dynobj
,
2979 const unsigned char* syms
,
2981 const char* sym_names
,
2982 size_t sym_name_size
,
2983 const unsigned char* versym
,
2985 const std::vector
<const char*>* version_map
,
2986 Sized_relobj
<32, false>::Symbols
* sympointers
,
2990 #ifdef HAVE_TARGET_32_BIG
2993 Symbol_table::add_from_dynobj
<32, true>(
2994 Sized_dynobj
<32, true>* dynobj
,
2995 const unsigned char* syms
,
2997 const char* sym_names
,
2998 size_t sym_name_size
,
2999 const unsigned char* versym
,
3001 const std::vector
<const char*>* version_map
,
3002 Sized_relobj
<32, true>::Symbols
* sympointers
,
3006 #ifdef HAVE_TARGET_64_LITTLE
3009 Symbol_table::add_from_dynobj
<64, false>(
3010 Sized_dynobj
<64, false>* dynobj
,
3011 const unsigned char* syms
,
3013 const char* sym_names
,
3014 size_t sym_name_size
,
3015 const unsigned char* versym
,
3017 const std::vector
<const char*>* version_map
,
3018 Sized_relobj
<64, false>::Symbols
* sympointers
,
3022 #ifdef HAVE_TARGET_64_BIG
3025 Symbol_table::add_from_dynobj
<64, true>(
3026 Sized_dynobj
<64, true>* dynobj
,
3027 const unsigned char* syms
,
3029 const char* sym_names
,
3030 size_t sym_name_size
,
3031 const unsigned char* versym
,
3033 const std::vector
<const char*>* version_map
,
3034 Sized_relobj
<64, true>::Symbols
* sympointers
,
3038 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3041 Symbol_table::define_with_copy_reloc
<32>(
3042 Sized_symbol
<32>* sym
,
3044 elfcpp::Elf_types
<32>::Elf_Addr value
);
3047 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3050 Symbol_table::define_with_copy_reloc
<64>(
3051 Sized_symbol
<64>* sym
,
3053 elfcpp::Elf_types
<64>::Elf_Addr value
);
3056 #ifdef HAVE_TARGET_32_LITTLE
3059 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
3060 const Relocate_info
<32, false>* relinfo
,
3061 size_t relnum
, off_t reloffset
) const;
3064 #ifdef HAVE_TARGET_32_BIG
3067 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
3068 const Relocate_info
<32, true>* relinfo
,
3069 size_t relnum
, off_t reloffset
) const;
3072 #ifdef HAVE_TARGET_64_LITTLE
3075 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
3076 const Relocate_info
<64, false>* relinfo
,
3077 size_t relnum
, off_t reloffset
) const;
3080 #ifdef HAVE_TARGET_64_BIG
3083 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
3084 const Relocate_info
<64, true>* relinfo
,
3085 size_t relnum
, off_t reloffset
) const;
3088 } // End namespace gold.