1 // symtab.cc -- the gold symbol table
3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
34 #include "dwarf_reader.h"
38 #include "workqueue.h"
46 // Initialize fields in Symbol. This initializes everything except u_
50 Symbol::init_fields(const char* name
, const char* version
,
51 elfcpp::STT type
, elfcpp::STB binding
,
52 elfcpp::STV visibility
, unsigned char nonvis
)
55 this->version_
= version
;
56 this->symtab_index_
= 0;
57 this->dynsym_index_
= 0;
58 this->got_offsets_
.init();
59 this->plt_offset_
= 0;
61 this->binding_
= binding
;
62 this->visibility_
= visibility
;
63 this->nonvis_
= nonvis
;
64 this->is_target_special_
= false;
65 this->is_def_
= false;
66 this->is_forwarder_
= false;
67 this->has_alias_
= false;
68 this->needs_dynsym_entry_
= false;
69 this->in_reg_
= false;
70 this->in_dyn_
= false;
71 this->has_plt_offset_
= false;
72 this->has_warning_
= false;
73 this->is_copied_from_dynobj_
= false;
74 this->is_forced_local_
= false;
77 // Return the demangled version of the symbol's name, but only
78 // if the --demangle flag was set.
81 demangle(const char* name
)
83 if (!parameters
->options().do_demangle())
86 // cplus_demangle allocates memory for the result it returns,
87 // and returns NULL if the name is already demangled.
88 char* demangled_name
= cplus_demangle(name
, DMGL_ANSI
| DMGL_PARAMS
);
89 if (demangled_name
== NULL
)
92 std::string
retval(demangled_name
);
98 Symbol::demangled_name() const
100 return demangle(this->name());
103 // Initialize the fields in the base class Symbol for SYM in OBJECT.
105 template<int size
, bool big_endian
>
107 Symbol::init_base(const char* name
, const char* version
, Object
* object
,
108 const elfcpp::Sym
<size
, big_endian
>& sym
)
110 this->init_fields(name
, version
, sym
.get_st_type(), sym
.get_st_bind(),
111 sym
.get_st_visibility(), sym
.get_st_nonvis());
112 this->u_
.from_object
.object
= object
;
113 // FIXME: Handle SHN_XINDEX.
114 this->u_
.from_object
.shndx
= sym
.get_st_shndx();
115 this->source_
= FROM_OBJECT
;
116 this->in_reg_
= !object
->is_dynamic();
117 this->in_dyn_
= object
->is_dynamic();
120 // Initialize the fields in the base class Symbol for a symbol defined
121 // in an Output_data.
124 Symbol::init_base(const char* name
, Output_data
* od
, elfcpp::STT type
,
125 elfcpp::STB binding
, elfcpp::STV visibility
,
126 unsigned char nonvis
, bool offset_is_from_end
)
128 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
129 this->u_
.in_output_data
.output_data
= od
;
130 this->u_
.in_output_data
.offset_is_from_end
= offset_is_from_end
;
131 this->source_
= IN_OUTPUT_DATA
;
132 this->in_reg_
= true;
135 // Initialize the fields in the base class Symbol for a symbol defined
136 // in an Output_segment.
139 Symbol::init_base(const char* name
, Output_segment
* os
, elfcpp::STT type
,
140 elfcpp::STB binding
, elfcpp::STV visibility
,
141 unsigned char nonvis
, Segment_offset_base offset_base
)
143 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
144 this->u_
.in_output_segment
.output_segment
= os
;
145 this->u_
.in_output_segment
.offset_base
= offset_base
;
146 this->source_
= IN_OUTPUT_SEGMENT
;
147 this->in_reg_
= true;
150 // Initialize the fields in the base class Symbol for a symbol defined
154 Symbol::init_base(const char* name
, elfcpp::STT type
,
155 elfcpp::STB binding
, elfcpp::STV visibility
,
156 unsigned char nonvis
)
158 this->init_fields(name
, NULL
, type
, binding
, visibility
, nonvis
);
159 this->source_
= CONSTANT
;
160 this->in_reg_
= true;
163 // Allocate a common symbol in the base.
166 Symbol::allocate_base_common(Output_data
* od
)
168 gold_assert(this->is_common());
169 this->source_
= IN_OUTPUT_DATA
;
170 this->u_
.in_output_data
.output_data
= od
;
171 this->u_
.in_output_data
.offset_is_from_end
= false;
174 // Initialize the fields in Sized_symbol for SYM in OBJECT.
177 template<bool big_endian
>
179 Sized_symbol
<size
>::init(const char* name
, const char* version
, Object
* object
,
180 const elfcpp::Sym
<size
, big_endian
>& sym
)
182 this->init_base(name
, version
, object
, sym
);
183 this->value_
= sym
.get_st_value();
184 this->symsize_
= sym
.get_st_size();
187 // Initialize the fields in Sized_symbol for a symbol defined in an
192 Sized_symbol
<size
>::init(const char* name
, Output_data
* od
,
193 Value_type value
, Size_type symsize
,
194 elfcpp::STT type
, elfcpp::STB binding
,
195 elfcpp::STV visibility
, unsigned char nonvis
,
196 bool offset_is_from_end
)
198 this->init_base(name
, od
, type
, binding
, visibility
, nonvis
,
200 this->value_
= value
;
201 this->symsize_
= symsize
;
204 // Initialize the fields in Sized_symbol for a symbol defined in an
209 Sized_symbol
<size
>::init(const char* name
, Output_segment
* os
,
210 Value_type value
, Size_type symsize
,
211 elfcpp::STT type
, elfcpp::STB binding
,
212 elfcpp::STV visibility
, unsigned char nonvis
,
213 Segment_offset_base offset_base
)
215 this->init_base(name
, os
, type
, binding
, visibility
, nonvis
, offset_base
);
216 this->value_
= value
;
217 this->symsize_
= symsize
;
220 // Initialize the fields in Sized_symbol for a symbol defined as a
225 Sized_symbol
<size
>::init(const char* name
, Value_type value
, Size_type symsize
,
226 elfcpp::STT type
, elfcpp::STB binding
,
227 elfcpp::STV visibility
, unsigned char nonvis
)
229 this->init_base(name
, type
, binding
, visibility
, nonvis
);
230 this->value_
= value
;
231 this->symsize_
= symsize
;
234 // Allocate a common symbol.
238 Sized_symbol
<size
>::allocate_common(Output_data
* od
, Value_type value
)
240 this->allocate_base_common(od
);
241 this->value_
= value
;
244 // Return true if this symbol should be added to the dynamic symbol
248 Symbol::should_add_dynsym_entry() const
250 // If the symbol is used by a dynamic relocation, we need to add it.
251 if (this->needs_dynsym_entry())
254 // If the symbol was forced local in a version script, do not add it.
255 if (this->is_forced_local())
258 // If exporting all symbols or building a shared library,
259 // and the symbol is defined in a regular object and is
260 // externally visible, we need to add it.
261 if ((parameters
->options().export_dynamic() || parameters
->options().shared())
262 && !this->is_from_dynobj()
263 && this->is_externally_visible())
269 // Return true if the final value of this symbol is known at link
273 Symbol::final_value_is_known() const
275 // If we are not generating an executable, then no final values are
276 // known, since they will change at runtime.
277 if (parameters
->options().shared() || parameters
->options().relocatable())
280 // If the symbol is not from an object file, then it is defined, and
282 if (this->source_
!= FROM_OBJECT
)
285 // If the symbol is from a dynamic object, then the final value is
287 if (this->object()->is_dynamic())
290 // If the symbol is not undefined (it is defined or common), then
291 // the final value is known.
292 if (!this->is_undefined())
295 // If the symbol is undefined, then whether the final value is known
296 // depends on whether we are doing a static link. If we are doing a
297 // dynamic link, then the final value could be filled in at runtime.
298 // This could reasonably be the case for a weak undefined symbol.
299 return parameters
->doing_static_link();
302 // Return the output section where this symbol is defined.
305 Symbol::output_section() const
307 switch (this->source_
)
311 unsigned int shndx
= this->u_
.from_object
.shndx
;
312 if (shndx
!= elfcpp::SHN_UNDEF
&& shndx
< elfcpp::SHN_LORESERVE
)
314 gold_assert(!this->u_
.from_object
.object
->is_dynamic());
315 Relobj
* relobj
= static_cast<Relobj
*>(this->u_
.from_object
.object
);
316 section_offset_type dummy
;
317 return relobj
->output_section(shndx
, &dummy
);
323 return this->u_
.in_output_data
.output_data
->output_section();
325 case IN_OUTPUT_SEGMENT
:
334 // Set the symbol's output section. This is used for symbols defined
335 // in scripts. This should only be called after the symbol table has
339 Symbol::set_output_section(Output_section
* os
)
341 switch (this->source_
)
345 gold_assert(this->output_section() == os
);
348 this->source_
= IN_OUTPUT_DATA
;
349 this->u_
.in_output_data
.output_data
= os
;
350 this->u_
.in_output_data
.offset_is_from_end
= false;
352 case IN_OUTPUT_SEGMENT
:
358 // Class Symbol_table.
360 Symbol_table::Symbol_table(unsigned int count
,
361 const Version_script_info
& version_script
)
362 : saw_undefined_(0), offset_(0), table_(count
), namepool_(),
363 forwarders_(), commons_(), forced_locals_(), warnings_(),
364 version_script_(version_script
)
366 namepool_
.reserve(count
);
369 Symbol_table::~Symbol_table()
373 // The hash function. The key values are Stringpool keys.
376 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key
& key
) const
378 return key
.first
^ key
.second
;
381 // The symbol table key equality function. This is called with
385 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key
& k1
,
386 const Symbol_table_key
& k2
) const
388 return k1
.first
== k2
.first
&& k1
.second
== k2
.second
;
391 // Make TO a symbol which forwards to FROM.
394 Symbol_table::make_forwarder(Symbol
* from
, Symbol
* to
)
396 gold_assert(from
!= to
);
397 gold_assert(!from
->is_forwarder() && !to
->is_forwarder());
398 this->forwarders_
[from
] = to
;
399 from
->set_forwarder();
402 // Resolve the forwards from FROM, returning the real symbol.
405 Symbol_table::resolve_forwards(const Symbol
* from
) const
407 gold_assert(from
->is_forwarder());
408 Unordered_map
<const Symbol
*, Symbol
*>::const_iterator p
=
409 this->forwarders_
.find(from
);
410 gold_assert(p
!= this->forwarders_
.end());
414 // Look up a symbol by name.
417 Symbol_table::lookup(const char* name
, const char* version
) const
419 Stringpool::Key name_key
;
420 name
= this->namepool_
.find(name
, &name_key
);
424 Stringpool::Key version_key
= 0;
427 version
= this->namepool_
.find(version
, &version_key
);
432 Symbol_table_key
key(name_key
, version_key
);
433 Symbol_table::Symbol_table_type::const_iterator p
= this->table_
.find(key
);
434 if (p
== this->table_
.end())
439 // Resolve a Symbol with another Symbol. This is only used in the
440 // unusual case where there are references to both an unversioned
441 // symbol and a symbol with a version, and we then discover that that
442 // version is the default version. Because this is unusual, we do
443 // this the slow way, by converting back to an ELF symbol.
445 template<int size
, bool big_endian
>
447 Symbol_table::resolve(Sized_symbol
<size
>* to
, const Sized_symbol
<size
>* from
,
450 unsigned char buf
[elfcpp::Elf_sizes
<size
>::sym_size
];
451 elfcpp::Sym_write
<size
, big_endian
> esym(buf
);
452 // We don't bother to set the st_name field.
453 esym
.put_st_value(from
->value());
454 esym
.put_st_size(from
->symsize());
455 esym
.put_st_info(from
->binding(), from
->type());
456 esym
.put_st_other(from
->visibility(), from
->nonvis());
457 esym
.put_st_shndx(from
->shndx());
458 this->resolve(to
, esym
.sym(), esym
.sym(), from
->object(), version
);
465 // Record that a symbol is forced to be local by a version script.
468 Symbol_table::force_local(Symbol
* sym
)
470 if (!sym
->is_defined() && !sym
->is_common())
472 if (sym
->is_forced_local())
474 // We already got this one.
477 sym
->set_is_forced_local();
478 this->forced_locals_
.push_back(sym
);
481 // Add one symbol from OBJECT to the symbol table. NAME is symbol
482 // name and VERSION is the version; both are canonicalized. DEF is
483 // whether this is the default version.
485 // If DEF is true, then this is the definition of a default version of
486 // a symbol. That means that any lookup of NAME/NULL and any lookup
487 // of NAME/VERSION should always return the same symbol. This is
488 // obvious for references, but in particular we want to do this for
489 // definitions: overriding NAME/NULL should also override
490 // NAME/VERSION. If we don't do that, it would be very hard to
491 // override functions in a shared library which uses versioning.
493 // We implement this by simply making both entries in the hash table
494 // point to the same Symbol structure. That is easy enough if this is
495 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
496 // that we have seen both already, in which case they will both have
497 // independent entries in the symbol table. We can't simply change
498 // the symbol table entry, because we have pointers to the entries
499 // attached to the object files. So we mark the entry attached to the
500 // object file as a forwarder, and record it in the forwarders_ map.
501 // Note that entries in the hash table will never be marked as
504 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
505 // symbol exactly as it existed in the input file. SYM is usually
506 // that as well, but can be modified, for instance if we determine
507 // it's in a to-be-discarded section.
509 template<int size
, bool big_endian
>
511 Symbol_table::add_from_object(Object
* object
,
513 Stringpool::Key name_key
,
515 Stringpool::Key version_key
,
517 const elfcpp::Sym
<size
, big_endian
>& sym
,
518 const elfcpp::Sym
<size
, big_endian
>& orig_sym
)
520 Symbol
* const snull
= NULL
;
521 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
522 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
525 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
526 std::make_pair(this->table_
.end(), false);
529 const Stringpool::Key vnull_key
= 0;
530 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
535 // ins.first: an iterator, which is a pointer to a pair.
536 // ins.first->first: the key (a pair of name and version).
537 // ins.first->second: the value (Symbol*).
538 // ins.second: true if new entry was inserted, false if not.
540 Sized_symbol
<size
>* ret
;
545 // We already have an entry for NAME/VERSION.
546 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
547 gold_assert(ret
!= NULL
);
549 was_undefined
= ret
->is_undefined();
550 was_common
= ret
->is_common();
552 this->resolve(ret
, sym
, orig_sym
, object
, version
);
558 // This is the first time we have seen NAME/NULL. Make
559 // NAME/NULL point to NAME/VERSION.
560 insdef
.first
->second
= ret
;
562 else if (insdef
.first
->second
!= ret
563 && insdef
.first
->second
->is_undefined())
565 // This is the unfortunate case where we already have
566 // entries for both NAME/VERSION and NAME/NULL. Note
567 // that we don't want to combine them if the existing
568 // symbol is going to override the new one. FIXME: We
569 // currently just test is_undefined, but this may not do
570 // the right thing if the existing symbol is from a
571 // shared library and the new one is from a regular
574 const Sized_symbol
<size
>* sym2
;
575 sym2
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
576 Symbol_table::resolve
<size
, big_endian
>(ret
, sym2
, version
);
577 this->make_forwarder(insdef
.first
->second
, ret
);
578 insdef
.first
->second
= ret
;
586 // This is the first time we have seen NAME/VERSION.
587 gold_assert(ins
.first
->second
== NULL
);
589 if (def
&& !insdef
.second
)
591 // We already have an entry for NAME/NULL. If we override
592 // it, then change it to NAME/VERSION.
593 ret
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
595 was_undefined
= ret
->is_undefined();
596 was_common
= ret
->is_common();
598 this->resolve(ret
, sym
, orig_sym
, object
, version
);
599 ins
.first
->second
= ret
;
603 was_undefined
= false;
606 Sized_target
<size
, big_endian
>* target
=
607 object
->sized_target
<size
, big_endian
>();
608 if (!target
->has_make_symbol())
609 ret
= new Sized_symbol
<size
>();
612 ret
= target
->make_symbol();
615 // This means that we don't want a symbol table
618 this->table_
.erase(ins
.first
);
621 this->table_
.erase(insdef
.first
);
622 // Inserting insdef invalidated ins.
623 this->table_
.erase(std::make_pair(name_key
,
630 ret
->init(name
, version
, object
, sym
);
632 ins
.first
->second
= ret
;
635 // This is the first time we have seen NAME/NULL. Point
636 // it at the new entry for NAME/VERSION.
637 gold_assert(insdef
.second
);
638 insdef
.first
->second
= ret
;
643 // Record every time we see a new undefined symbol, to speed up
645 if (!was_undefined
&& ret
->is_undefined())
646 ++this->saw_undefined_
;
648 // Keep track of common symbols, to speed up common symbol
650 if (!was_common
&& ret
->is_common())
651 this->commons_
.push_back(ret
);
654 ret
->set_is_default();
658 // Add all the symbols in a relocatable object to the hash table.
660 template<int size
, bool big_endian
>
662 Symbol_table::add_from_relobj(
663 Sized_relobj
<size
, big_endian
>* relobj
,
664 const unsigned char* syms
,
666 const char* sym_names
,
667 size_t sym_name_size
,
668 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
)
670 gold_assert(size
== relobj
->target()->get_size());
671 gold_assert(size
== parameters
->target().get_size());
673 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
675 const bool just_symbols
= relobj
->just_symbols();
677 const unsigned char* p
= syms
;
678 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
680 elfcpp::Sym
<size
, big_endian
> sym(p
);
681 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
683 unsigned int st_name
= psym
->get_st_name();
684 if (st_name
>= sym_name_size
)
686 relobj
->error(_("bad global symbol name offset %u at %zu"),
691 const char* name
= sym_names
+ st_name
;
693 // A symbol defined in a section which we are not including must
694 // be treated as an undefined symbol.
695 unsigned char symbuf
[sym_size
];
696 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
697 unsigned int st_shndx
= psym
->get_st_shndx();
698 if (st_shndx
!= elfcpp::SHN_UNDEF
699 && st_shndx
< elfcpp::SHN_LORESERVE
700 && !relobj
->is_section_included(st_shndx
))
702 memcpy(symbuf
, p
, sym_size
);
703 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
704 sw
.put_st_shndx(elfcpp::SHN_UNDEF
);
708 // In an object file, an '@' in the name separates the symbol
709 // name from the version name. If there are two '@' characters,
710 // this is the default version.
711 const char* ver
= strchr(name
, '@');
713 // DEF: is the version default? LOCAL: is the symbol forced local?
719 // The symbol name is of the form foo@VERSION or foo@@VERSION
720 namelen
= ver
- name
;
728 // We don't want to assign a version to an undefined symbol,
729 // even if it is listed in the version script. FIXME: What
730 // about a common symbol?
731 else if (!version_script_
.empty()
732 && psym
->get_st_shndx() != elfcpp::SHN_UNDEF
)
734 // The symbol name did not have a version, but
735 // the version script may assign a version anyway.
736 namelen
= strlen(name
);
738 // Check the global: entries from the version script.
739 const std::string
& version
=
740 version_script_
.get_symbol_version(name
);
741 if (!version
.empty())
742 ver
= version
.c_str();
743 // Check the local: entries from the version script
744 if (version_script_
.symbol_is_local(name
))
751 memcpy(symbuf
, p
, sym_size
);
752 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
753 sw
.put_st_shndx(elfcpp::SHN_ABS
);
754 if (st_shndx
!= elfcpp::SHN_UNDEF
755 && st_shndx
< elfcpp::SHN_LORESERVE
)
757 // Symbol values in object files are section relative.
758 // This is normally what we want, but since here we are
759 // converting the symbol to absolute we need to add the
760 // section address. The section address in an object
761 // file is normally zero, but people can use a linker
762 // script to change it.
763 sw
.put_st_value(sym2
.get_st_value()
764 + relobj
->section_address(st_shndx
));
769 Sized_symbol
<size
>* res
;
772 Stringpool::Key name_key
;
773 name
= this->namepool_
.add(name
, true, &name_key
);
774 res
= this->add_from_object(relobj
, name
, name_key
, NULL
, 0,
777 this->force_local(res
);
781 Stringpool::Key name_key
;
782 name
= this->namepool_
.add_with_length(name
, namelen
, true,
784 Stringpool::Key ver_key
;
785 ver
= this->namepool_
.add(ver
, true, &ver_key
);
787 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
791 (*sympointers
)[i
] = res
;
795 // Add all the symbols in a dynamic object to the hash table.
797 template<int size
, bool big_endian
>
799 Symbol_table::add_from_dynobj(
800 Sized_dynobj
<size
, big_endian
>* dynobj
,
801 const unsigned char* syms
,
803 const char* sym_names
,
804 size_t sym_name_size
,
805 const unsigned char* versym
,
807 const std::vector
<const char*>* version_map
)
809 gold_assert(size
== dynobj
->target()->get_size());
810 gold_assert(size
== parameters
->target().get_size());
812 if (dynobj
->just_symbols())
814 gold_error(_("--just-symbols does not make sense with a shared object"));
818 if (versym
!= NULL
&& versym_size
/ 2 < count
)
820 dynobj
->error(_("too few symbol versions"));
824 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
826 // We keep a list of all STT_OBJECT symbols, so that we can resolve
827 // weak aliases. This is necessary because if the dynamic object
828 // provides the same variable under two names, one of which is a
829 // weak definition, and the regular object refers to the weak
830 // definition, we have to put both the weak definition and the
831 // strong definition into the dynamic symbol table. Given a weak
832 // definition, the only way that we can find the corresponding
833 // strong definition, if any, is to search the symbol table.
834 std::vector
<Sized_symbol
<size
>*> object_symbols
;
836 const unsigned char* p
= syms
;
837 const unsigned char* vs
= versym
;
838 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
840 elfcpp::Sym
<size
, big_endian
> sym(p
);
842 // Ignore symbols with local binding or that have
843 // internal or hidden visibility.
844 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
845 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
846 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
849 unsigned int st_name
= sym
.get_st_name();
850 if (st_name
>= sym_name_size
)
852 dynobj
->error(_("bad symbol name offset %u at %zu"),
857 const char* name
= sym_names
+ st_name
;
859 Sized_symbol
<size
>* res
;
863 Stringpool::Key name_key
;
864 name
= this->namepool_
.add(name
, true, &name_key
);
865 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
870 // Read the version information.
872 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
874 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
875 v
&= elfcpp::VERSYM_VERSION
;
877 // The Sun documentation says that V can be VER_NDX_LOCAL,
878 // or VER_NDX_GLOBAL, or a version index. The meaning of
879 // VER_NDX_LOCAL is defined as "Symbol has local scope."
880 // The old GNU linker will happily generate VER_NDX_LOCAL
881 // for an undefined symbol. I don't know what the Sun
882 // linker will generate.
884 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
885 && sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
887 // This symbol should not be visible outside the object.
891 // At this point we are definitely going to add this symbol.
892 Stringpool::Key name_key
;
893 name
= this->namepool_
.add(name
, true, &name_key
);
895 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
896 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
898 // This symbol does not have a version.
899 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
904 if (v
>= version_map
->size())
906 dynobj
->error(_("versym for symbol %zu out of range: %u"),
911 const char* version
= (*version_map
)[v
];
914 dynobj
->error(_("versym for symbol %zu has no name: %u"),
919 Stringpool::Key version_key
;
920 version
= this->namepool_
.add(version
, true, &version_key
);
922 // If this is an absolute symbol, and the version name
923 // and symbol name are the same, then this is the
924 // version definition symbol. These symbols exist to
925 // support using -u to pull in particular versions. We
926 // do not want to record a version for them.
927 if (sym
.get_st_shndx() == elfcpp::SHN_ABS
928 && name_key
== version_key
)
929 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
933 const bool def
= (!hidden
934 && (sym
.get_st_shndx()
935 != elfcpp::SHN_UNDEF
));
936 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
937 version_key
, def
, sym
, sym
);
942 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
943 && sym
.get_st_type() == elfcpp::STT_OBJECT
)
944 object_symbols
.push_back(res
);
947 this->record_weak_aliases(&object_symbols
);
950 // This is used to sort weak aliases. We sort them first by section
951 // index, then by offset, then by weak ahead of strong.
954 class Weak_alias_sorter
957 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
962 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
963 const Sized_symbol
<size
>* s2
) const
965 if (s1
->shndx() != s2
->shndx())
966 return s1
->shndx() < s2
->shndx();
967 if (s1
->value() != s2
->value())
968 return s1
->value() < s2
->value();
969 if (s1
->binding() != s2
->binding())
971 if (s1
->binding() == elfcpp::STB_WEAK
)
973 if (s2
->binding() == elfcpp::STB_WEAK
)
976 return std::string(s1
->name()) < std::string(s2
->name());
979 // SYMBOLS is a list of object symbols from a dynamic object. Look
980 // for any weak aliases, and record them so that if we add the weak
981 // alias to the dynamic symbol table, we also add the corresponding
986 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
988 // Sort the vector by section index, then by offset, then by weak
990 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
992 // Walk through the vector. For each weak definition, record
994 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
999 if ((*p
)->binding() != elfcpp::STB_WEAK
)
1002 // Build a circular list of weak aliases. Each symbol points to
1003 // the next one in the circular list.
1005 Sized_symbol
<size
>* from_sym
= *p
;
1006 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
1007 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
1009 if ((*q
)->shndx() != from_sym
->shndx()
1010 || (*q
)->value() != from_sym
->value())
1013 this->weak_aliases_
[from_sym
] = *q
;
1014 from_sym
->set_has_alias();
1020 this->weak_aliases_
[from_sym
] = *p
;
1021 from_sym
->set_has_alias();
1028 // Create and return a specially defined symbol. If ONLY_IF_REF is
1029 // true, then only create the symbol if there is a reference to it.
1030 // If this does not return NULL, it sets *POLDSYM to the existing
1031 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1033 template<int size
, bool big_endian
>
1035 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1037 Sized_symbol
<size
>** poldsym
)
1040 Sized_symbol
<size
>* sym
;
1041 bool add_to_table
= false;
1042 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1044 // If the caller didn't give us a version, see if we get one from
1045 // the version script.
1046 if (*pversion
== NULL
)
1048 const std::string
& v(this->version_script_
.get_symbol_version(*pname
));
1050 *pversion
= v
.c_str();
1055 oldsym
= this->lookup(*pname
, *pversion
);
1056 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1059 *pname
= oldsym
->name();
1060 *pversion
= oldsym
->version();
1064 // Canonicalize NAME and VERSION.
1065 Stringpool::Key name_key
;
1066 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1068 Stringpool::Key version_key
= 0;
1069 if (*pversion
!= NULL
)
1070 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1072 Symbol
* const snull
= NULL
;
1073 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1074 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1080 // We already have a symbol table entry for NAME/VERSION.
1081 oldsym
= ins
.first
->second
;
1082 gold_assert(oldsym
!= NULL
);
1086 // We haven't seen this symbol before.
1087 gold_assert(ins
.first
->second
== NULL
);
1088 add_to_table
= true;
1089 add_loc
= ins
.first
;
1094 const Target
& target
= parameters
->target();
1095 if (!target
.has_make_symbol())
1096 sym
= new Sized_symbol
<size
>();
1099 gold_assert(target
.get_size() == size
);
1100 gold_assert(target
.is_big_endian() ? big_endian
: !big_endian
);
1101 typedef Sized_target
<size
, big_endian
> My_target
;
1102 const My_target
* sized_target
=
1103 static_cast<const My_target
*>(&target
);
1104 sym
= sized_target
->make_symbol();
1110 add_loc
->second
= sym
;
1112 gold_assert(oldsym
!= NULL
);
1114 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1119 // Define a symbol based on an Output_data.
1122 Symbol_table::define_in_output_data(const char* name
,
1123 const char* version
,
1128 elfcpp::STB binding
,
1129 elfcpp::STV visibility
,
1130 unsigned char nonvis
,
1131 bool offset_is_from_end
,
1134 if (parameters
->target().get_size() == 32)
1136 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1137 return this->do_define_in_output_data
<32>(name
, version
, od
,
1138 value
, symsize
, type
, binding
,
1146 else if (parameters
->target().get_size() == 64)
1148 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1149 return this->do_define_in_output_data
<64>(name
, version
, od
,
1150 value
, symsize
, type
, binding
,
1162 // Define a symbol in an Output_data, sized version.
1166 Symbol_table::do_define_in_output_data(
1168 const char* version
,
1170 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1171 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1173 elfcpp::STB binding
,
1174 elfcpp::STV visibility
,
1175 unsigned char nonvis
,
1176 bool offset_is_from_end
,
1179 Sized_symbol
<size
>* sym
;
1180 Sized_symbol
<size
>* oldsym
;
1182 if (parameters
->target().is_big_endian())
1184 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1185 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1186 only_if_ref
, &oldsym
);
1193 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1194 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1195 only_if_ref
, &oldsym
);
1204 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1205 sym
->init(name
, od
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1206 offset_is_from_end
);
1210 if (binding
== elfcpp::STB_LOCAL
1211 || this->version_script_
.symbol_is_local(name
))
1212 this->force_local(sym
);
1216 if (Symbol_table::should_override_with_special(oldsym
))
1217 this->override_with_special(oldsym
, sym
);
1222 // Define a symbol based on an Output_segment.
1225 Symbol_table::define_in_output_segment(const char* name
,
1226 const char* version
, Output_segment
* os
,
1230 elfcpp::STB binding
,
1231 elfcpp::STV visibility
,
1232 unsigned char nonvis
,
1233 Symbol::Segment_offset_base offset_base
,
1236 if (parameters
->target().get_size() == 32)
1238 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1239 return this->do_define_in_output_segment
<32>(name
, version
, os
,
1240 value
, symsize
, type
,
1241 binding
, visibility
, nonvis
,
1242 offset_base
, only_if_ref
);
1247 else if (parameters
->target().get_size() == 64)
1249 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1250 return this->do_define_in_output_segment
<64>(name
, version
, os
,
1251 value
, symsize
, type
,
1252 binding
, visibility
, nonvis
,
1253 offset_base
, only_if_ref
);
1262 // Define a symbol in an Output_segment, sized version.
1266 Symbol_table::do_define_in_output_segment(
1268 const char* version
,
1270 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1271 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1273 elfcpp::STB binding
,
1274 elfcpp::STV visibility
,
1275 unsigned char nonvis
,
1276 Symbol::Segment_offset_base offset_base
,
1279 Sized_symbol
<size
>* sym
;
1280 Sized_symbol
<size
>* oldsym
;
1282 if (parameters
->target().is_big_endian())
1284 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1285 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1286 only_if_ref
, &oldsym
);
1293 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1294 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1295 only_if_ref
, &oldsym
);
1304 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1305 sym
->init(name
, os
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1310 if (binding
== elfcpp::STB_LOCAL
1311 || this->version_script_
.symbol_is_local(name
))
1312 this->force_local(sym
);
1316 if (Symbol_table::should_override_with_special(oldsym
))
1317 this->override_with_special(oldsym
, sym
);
1322 // Define a special symbol with a constant value. It is a multiple
1323 // definition error if this symbol is already defined.
1326 Symbol_table::define_as_constant(const char* name
,
1327 const char* version
,
1331 elfcpp::STB binding
,
1332 elfcpp::STV visibility
,
1333 unsigned char nonvis
,
1335 bool force_override
)
1337 if (parameters
->target().get_size() == 32)
1339 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1340 return this->do_define_as_constant
<32>(name
, version
, value
,
1341 symsize
, type
, binding
,
1342 visibility
, nonvis
, only_if_ref
,
1348 else if (parameters
->target().get_size() == 64)
1350 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1351 return this->do_define_as_constant
<64>(name
, version
, value
,
1352 symsize
, type
, binding
,
1353 visibility
, nonvis
, only_if_ref
,
1363 // Define a symbol as a constant, sized version.
1367 Symbol_table::do_define_as_constant(
1369 const char* version
,
1370 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1371 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1373 elfcpp::STB binding
,
1374 elfcpp::STV visibility
,
1375 unsigned char nonvis
,
1377 bool force_override
)
1379 Sized_symbol
<size
>* sym
;
1380 Sized_symbol
<size
>* oldsym
;
1382 if (parameters
->target().is_big_endian())
1384 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1385 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1386 only_if_ref
, &oldsym
);
1393 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1394 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1395 only_if_ref
, &oldsym
);
1404 gold_assert(version
== NULL
|| version
== name
|| oldsym
!= NULL
);
1405 sym
->init(name
, value
, symsize
, type
, binding
, visibility
, nonvis
);
1409 // Version symbols are absolute symbols with name == version.
1410 // We don't want to force them to be local.
1411 if ((version
== NULL
1414 && (binding
== elfcpp::STB_LOCAL
1415 || this->version_script_
.symbol_is_local(name
)))
1416 this->force_local(sym
);
1420 if (force_override
|| Symbol_table::should_override_with_special(oldsym
))
1421 this->override_with_special(oldsym
, sym
);
1426 // Define a set of symbols in output sections.
1429 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1430 const Define_symbol_in_section
* p
,
1433 for (int i
= 0; i
< count
; ++i
, ++p
)
1435 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1437 this->define_in_output_data(p
->name
, NULL
, os
, p
->value
,
1438 p
->size
, p
->type
, p
->binding
,
1439 p
->visibility
, p
->nonvis
,
1440 p
->offset_is_from_end
,
1441 only_if_ref
|| p
->only_if_ref
);
1443 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1444 p
->binding
, p
->visibility
, p
->nonvis
,
1445 only_if_ref
|| p
->only_if_ref
,
1450 // Define a set of symbols in output segments.
1453 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1454 const Define_symbol_in_segment
* p
,
1457 for (int i
= 0; i
< count
; ++i
, ++p
)
1459 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1460 p
->segment_flags_set
,
1461 p
->segment_flags_clear
);
1463 this->define_in_output_segment(p
->name
, NULL
, os
, p
->value
,
1464 p
->size
, p
->type
, p
->binding
,
1465 p
->visibility
, p
->nonvis
,
1467 only_if_ref
|| p
->only_if_ref
);
1469 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1470 p
->binding
, p
->visibility
, p
->nonvis
,
1471 only_if_ref
|| p
->only_if_ref
,
1476 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1477 // symbol should be defined--typically a .dyn.bss section. VALUE is
1478 // the offset within POSD.
1482 Symbol_table::define_with_copy_reloc(
1483 Sized_symbol
<size
>* csym
,
1485 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1487 gold_assert(csym
->is_from_dynobj());
1488 gold_assert(!csym
->is_copied_from_dynobj());
1489 Object
* object
= csym
->object();
1490 gold_assert(object
->is_dynamic());
1491 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1493 // Our copied variable has to override any variable in a shared
1495 elfcpp::STB binding
= csym
->binding();
1496 if (binding
== elfcpp::STB_WEAK
)
1497 binding
= elfcpp::STB_GLOBAL
;
1499 this->define_in_output_data(csym
->name(), csym
->version(),
1500 posd
, value
, csym
->symsize(),
1501 csym
->type(), binding
,
1502 csym
->visibility(), csym
->nonvis(),
1505 csym
->set_is_copied_from_dynobj();
1506 csym
->set_needs_dynsym_entry();
1508 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1510 // We have now defined all aliases, but we have not entered them all
1511 // in the copied_symbol_dynobjs_ map.
1512 if (csym
->has_alias())
1517 sym
= this->weak_aliases_
[sym
];
1520 gold_assert(sym
->output_data() == posd
);
1522 sym
->set_is_copied_from_dynobj();
1523 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1528 // SYM is defined using a COPY reloc. Return the dynamic object where
1529 // the original definition was found.
1532 Symbol_table::get_copy_source(const Symbol
* sym
) const
1534 gold_assert(sym
->is_copied_from_dynobj());
1535 Copied_symbol_dynobjs::const_iterator p
=
1536 this->copied_symbol_dynobjs_
.find(sym
);
1537 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1541 // Set the dynamic symbol indexes. INDEX is the index of the first
1542 // global dynamic symbol. Pointers to the symbols are stored into the
1543 // vector SYMS. The names are added to DYNPOOL. This returns an
1544 // updated dynamic symbol index.
1547 Symbol_table::set_dynsym_indexes(unsigned int index
,
1548 std::vector
<Symbol
*>* syms
,
1549 Stringpool
* dynpool
,
1552 for (Symbol_table_type::iterator p
= this->table_
.begin();
1553 p
!= this->table_
.end();
1556 Symbol
* sym
= p
->second
;
1558 // Note that SYM may already have a dynamic symbol index, since
1559 // some symbols appear more than once in the symbol table, with
1560 // and without a version.
1562 if (!sym
->should_add_dynsym_entry())
1563 sym
->set_dynsym_index(-1U);
1564 else if (!sym
->has_dynsym_index())
1566 sym
->set_dynsym_index(index
);
1568 syms
->push_back(sym
);
1569 dynpool
->add(sym
->name(), false, NULL
);
1571 // Record any version information.
1572 if (sym
->version() != NULL
)
1573 versions
->record_version(this, dynpool
, sym
);
1577 // Finish up the versions. In some cases this may add new dynamic
1579 index
= versions
->finalize(this, index
, syms
);
1584 // Set the final values for all the symbols. The index of the first
1585 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1586 // file offset OFF. Add their names to POOL. Return the new file
1587 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1590 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
1591 size_t dyncount
, Stringpool
* pool
,
1592 unsigned int *plocal_symcount
)
1596 gold_assert(*plocal_symcount
!= 0);
1597 this->first_global_index_
= *plocal_symcount
;
1599 this->dynamic_offset_
= dynoff
;
1600 this->first_dynamic_global_index_
= dyn_global_index
;
1601 this->dynamic_count_
= dyncount
;
1603 if (parameters
->target().get_size() == 32)
1605 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1606 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
1611 else if (parameters
->target().get_size() == 64)
1613 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1614 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
1622 // Now that we have the final symbol table, we can reliably note
1623 // which symbols should get warnings.
1624 this->warnings_
.note_warnings(this);
1629 // SYM is going into the symbol table at *PINDEX. Add the name to
1630 // POOL, update *PINDEX and *POFF.
1634 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
1635 unsigned int* pindex
, off_t
* poff
)
1637 sym
->set_symtab_index(*pindex
);
1638 pool
->add(sym
->name(), false, NULL
);
1640 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
1643 // Set the final value for all the symbols. This is called after
1644 // Layout::finalize, so all the output sections have their final
1649 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
1650 unsigned int* plocal_symcount
)
1652 off
= align_address(off
, size
>> 3);
1653 this->offset_
= off
;
1655 unsigned int index
= *plocal_symcount
;
1656 const unsigned int orig_index
= index
;
1658 // First do all the symbols which have been forced to be local, as
1659 // they must appear before all global symbols.
1660 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
1661 p
!= this->forced_locals_
.end();
1665 gold_assert(sym
->is_forced_local());
1666 if (this->sized_finalize_symbol
<size
>(sym
))
1668 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1673 // Now do all the remaining symbols.
1674 for (Symbol_table_type::iterator p
= this->table_
.begin();
1675 p
!= this->table_
.end();
1678 Symbol
* sym
= p
->second
;
1679 if (this->sized_finalize_symbol
<size
>(sym
))
1680 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1683 this->output_count_
= index
- orig_index
;
1688 // Finalize the symbol SYM. This returns true if the symbol should be
1689 // added to the symbol table, false otherwise.
1693 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
1695 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
1697 // The default version of a symbol may appear twice in the symbol
1698 // table. We only need to finalize it once.
1699 if (sym
->has_symtab_index())
1704 gold_assert(!sym
->has_symtab_index());
1705 sym
->set_symtab_index(-1U);
1706 gold_assert(sym
->dynsym_index() == -1U);
1710 typename Sized_symbol
<size
>::Value_type value
;
1712 switch (sym
->source())
1714 case Symbol::FROM_OBJECT
:
1716 unsigned int shndx
= sym
->shndx();
1718 // FIXME: We need some target specific support here.
1719 if (shndx
>= elfcpp::SHN_LORESERVE
1720 && shndx
!= elfcpp::SHN_ABS
1721 && shndx
!= elfcpp::SHN_COMMON
)
1723 gold_error(_("%s: unsupported symbol section 0x%x"),
1724 sym
->demangled_name().c_str(), shndx
);
1725 shndx
= elfcpp::SHN_UNDEF
;
1728 Object
* symobj
= sym
->object();
1729 if (symobj
->is_dynamic())
1732 shndx
= elfcpp::SHN_UNDEF
;
1734 else if (shndx
== elfcpp::SHN_UNDEF
)
1736 else if (shndx
== elfcpp::SHN_ABS
|| shndx
== elfcpp::SHN_COMMON
)
1737 value
= sym
->value();
1740 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1741 section_offset_type secoff
;
1742 Output_section
* os
= relobj
->output_section(shndx
, &secoff
);
1746 sym
->set_symtab_index(-1U);
1747 gold_assert(sym
->dynsym_index() == -1U);
1751 if (sym
->type() == elfcpp::STT_TLS
)
1752 value
= sym
->value() + os
->tls_offset() + secoff
;
1754 value
= sym
->value() + os
->address() + secoff
;
1759 case Symbol::IN_OUTPUT_DATA
:
1761 Output_data
* od
= sym
->output_data();
1762 value
= sym
->value() + od
->address();
1763 if (sym
->offset_is_from_end())
1764 value
+= od
->data_size();
1768 case Symbol::IN_OUTPUT_SEGMENT
:
1770 Output_segment
* os
= sym
->output_segment();
1771 value
= sym
->value() + os
->vaddr();
1772 switch (sym
->offset_base())
1774 case Symbol::SEGMENT_START
:
1776 case Symbol::SEGMENT_END
:
1777 value
+= os
->memsz();
1779 case Symbol::SEGMENT_BSS
:
1780 value
+= os
->filesz();
1788 case Symbol::CONSTANT
:
1789 value
= sym
->value();
1796 sym
->set_value(value
);
1798 if (parameters
->options().strip_all())
1800 sym
->set_symtab_index(-1U);
1807 // Write out the global symbols.
1810 Symbol_table::write_globals(const Input_objects
* input_objects
,
1811 const Stringpool
* sympool
,
1812 const Stringpool
* dynpool
, Output_file
* of
) const
1814 switch (parameters
->size_and_endianness())
1816 #ifdef HAVE_TARGET_32_LITTLE
1817 case Parameters::TARGET_32_LITTLE
:
1818 this->sized_write_globals
<32, false>(input_objects
, sympool
,
1822 #ifdef HAVE_TARGET_32_BIG
1823 case Parameters::TARGET_32_BIG
:
1824 this->sized_write_globals
<32, true>(input_objects
, sympool
,
1828 #ifdef HAVE_TARGET_64_LITTLE
1829 case Parameters::TARGET_64_LITTLE
:
1830 this->sized_write_globals
<64, false>(input_objects
, sympool
,
1834 #ifdef HAVE_TARGET_64_BIG
1835 case Parameters::TARGET_64_BIG
:
1836 this->sized_write_globals
<64, true>(input_objects
, sympool
,
1845 // Write out the global symbols.
1847 template<int size
, bool big_endian
>
1849 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
1850 const Stringpool
* sympool
,
1851 const Stringpool
* dynpool
,
1852 Output_file
* of
) const
1854 const Target
& target
= parameters
->target();
1856 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1858 const unsigned int output_count
= this->output_count_
;
1859 const section_size_type oview_size
= output_count
* sym_size
;
1860 const unsigned int first_global_index
= this->first_global_index_
;
1861 unsigned char* psyms
;
1862 if (this->offset_
== 0 || output_count
== 0)
1865 psyms
= of
->get_output_view(this->offset_
, oview_size
);
1867 const unsigned int dynamic_count
= this->dynamic_count_
;
1868 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
1869 const unsigned int first_dynamic_global_index
=
1870 this->first_dynamic_global_index_
;
1871 unsigned char* dynamic_view
;
1872 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
1873 dynamic_view
= NULL
;
1875 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
1877 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1878 p
!= this->table_
.end();
1881 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1883 // Possibly warn about unresolved symbols in shared libraries.
1884 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
1886 unsigned int sym_index
= sym
->symtab_index();
1887 unsigned int dynsym_index
;
1888 if (dynamic_view
== NULL
)
1891 dynsym_index
= sym
->dynsym_index();
1893 if (sym_index
== -1U && dynsym_index
== -1U)
1895 // This symbol is not included in the output file.
1900 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
1901 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
1902 switch (sym
->source())
1904 case Symbol::FROM_OBJECT
:
1906 unsigned int in_shndx
= sym
->shndx();
1908 // FIXME: We need some target specific support here.
1909 if (in_shndx
>= elfcpp::SHN_LORESERVE
1910 && in_shndx
!= elfcpp::SHN_ABS
1911 && in_shndx
!= elfcpp::SHN_COMMON
)
1913 gold_error(_("%s: unsupported symbol section 0x%x"),
1914 sym
->demangled_name().c_str(), in_shndx
);
1919 Object
* symobj
= sym
->object();
1920 if (symobj
->is_dynamic())
1922 if (sym
->needs_dynsym_value())
1923 dynsym_value
= target
.dynsym_value(sym
);
1924 shndx
= elfcpp::SHN_UNDEF
;
1926 else if (in_shndx
== elfcpp::SHN_UNDEF
1927 || in_shndx
== elfcpp::SHN_ABS
1928 || in_shndx
== elfcpp::SHN_COMMON
)
1932 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1933 section_offset_type secoff
;
1934 Output_section
* os
= relobj
->output_section(in_shndx
,
1936 gold_assert(os
!= NULL
);
1937 shndx
= os
->out_shndx();
1939 // In object files symbol values are section
1941 if (parameters
->options().relocatable())
1942 sym_value
-= os
->address();
1948 case Symbol::IN_OUTPUT_DATA
:
1949 shndx
= sym
->output_data()->out_shndx();
1952 case Symbol::IN_OUTPUT_SEGMENT
:
1953 shndx
= elfcpp::SHN_ABS
;
1956 case Symbol::CONSTANT
:
1957 shndx
= elfcpp::SHN_ABS
;
1964 if (sym_index
!= -1U)
1966 sym_index
-= first_global_index
;
1967 gold_assert(sym_index
< output_count
);
1968 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
1969 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
1973 if (dynsym_index
!= -1U)
1975 dynsym_index
-= first_dynamic_global_index
;
1976 gold_assert(dynsym_index
< dynamic_count
);
1977 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
1978 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
1983 of
->write_output_view(this->offset_
, oview_size
, psyms
);
1984 if (dynamic_view
!= NULL
)
1985 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
1988 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
1989 // strtab holding the name.
1991 template<int size
, bool big_endian
>
1993 Symbol_table::sized_write_symbol(
1994 Sized_symbol
<size
>* sym
,
1995 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1997 const Stringpool
* pool
,
1998 unsigned char* p
) const
2000 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
2001 osym
.put_st_name(pool
->get_offset(sym
->name()));
2002 osym
.put_st_value(value
);
2003 osym
.put_st_size(sym
->symsize());
2004 // A version script may have overridden the default binding.
2005 if (sym
->is_forced_local())
2006 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, sym
->type()));
2008 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
2009 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
2010 osym
.put_st_shndx(shndx
);
2013 // Check for unresolved symbols in shared libraries. This is
2014 // controlled by the --allow-shlib-undefined option.
2016 // We only warn about libraries for which we have seen all the
2017 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2018 // which were not seen in this link. If we didn't see a DT_NEEDED
2019 // entry, we aren't going to be able to reliably report whether the
2020 // symbol is undefined.
2022 // We also don't warn about libraries found in the system library
2023 // directory (the directory were we find libc.so); we assume that
2024 // those libraries are OK. This heuristic avoids problems in
2025 // GNU/Linux, in which -ldl can have undefined references satisfied by
2029 Symbol_table::warn_about_undefined_dynobj_symbol(
2030 const Input_objects
* input_objects
,
2033 if (sym
->source() == Symbol::FROM_OBJECT
2034 && sym
->object()->is_dynamic()
2035 && sym
->shndx() == elfcpp::SHN_UNDEF
2036 && sym
->binding() != elfcpp::STB_WEAK
2037 && !parameters
->options().allow_shlib_undefined()
2038 && !parameters
->target().is_defined_by_abi(sym
)
2039 && !input_objects
->found_in_system_library_directory(sym
->object()))
2041 // A very ugly cast.
2042 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
2043 if (!dynobj
->has_unknown_needed_entries())
2044 gold_error(_("%s: undefined reference to '%s'"),
2045 sym
->object()->name().c_str(),
2046 sym
->demangled_name().c_str());
2050 // Write out a section symbol. Return the update offset.
2053 Symbol_table::write_section_symbol(const Output_section
*os
,
2057 switch (parameters
->size_and_endianness())
2059 #ifdef HAVE_TARGET_32_LITTLE
2060 case Parameters::TARGET_32_LITTLE
:
2061 this->sized_write_section_symbol
<32, false>(os
, of
, offset
);
2064 #ifdef HAVE_TARGET_32_BIG
2065 case Parameters::TARGET_32_BIG
:
2066 this->sized_write_section_symbol
<32, true>(os
, of
, offset
);
2069 #ifdef HAVE_TARGET_64_LITTLE
2070 case Parameters::TARGET_64_LITTLE
:
2071 this->sized_write_section_symbol
<64, false>(os
, of
, offset
);
2074 #ifdef HAVE_TARGET_64_BIG
2075 case Parameters::TARGET_64_BIG
:
2076 this->sized_write_section_symbol
<64, true>(os
, of
, offset
);
2084 // Write out a section symbol, specialized for size and endianness.
2086 template<int size
, bool big_endian
>
2088 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
2092 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2094 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
2096 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
2097 osym
.put_st_name(0);
2098 osym
.put_st_value(os
->address());
2099 osym
.put_st_size(0);
2100 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
2101 elfcpp::STT_SECTION
));
2102 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
2103 osym
.put_st_shndx(os
->out_shndx());
2105 of
->write_output_view(offset
, sym_size
, pov
);
2108 // Print statistical information to stderr. This is used for --stats.
2111 Symbol_table::print_stats() const
2113 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2114 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2115 program_name
, this->table_
.size(), this->table_
.bucket_count());
2117 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
2118 program_name
, this->table_
.size());
2120 this->namepool_
.print_stats("symbol table stringpool");
2123 // We check for ODR violations by looking for symbols with the same
2124 // name for which the debugging information reports that they were
2125 // defined in different source locations. When comparing the source
2126 // location, we consider instances with the same base filename and
2127 // line number to be the same. This is because different object
2128 // files/shared libraries can include the same header file using
2129 // different paths, and we don't want to report an ODR violation in
2132 // This struct is used to compare line information, as returned by
2133 // Dwarf_line_info::one_addr2line. It implements a < comparison
2134 // operator used with std::set.
2136 struct Odr_violation_compare
2139 operator()(const std::string
& s1
, const std::string
& s2
) const
2141 std::string::size_type pos1
= s1
.rfind('/');
2142 std::string::size_type pos2
= s2
.rfind('/');
2143 if (pos1
== std::string::npos
2144 || pos2
== std::string::npos
)
2146 return s1
.compare(pos1
, std::string::npos
,
2147 s2
, pos2
, std::string::npos
) < 0;
2151 // Check candidate_odr_violations_ to find symbols with the same name
2152 // but apparently different definitions (different source-file/line-no).
2155 Symbol_table::detect_odr_violations(const Task
* task
,
2156 const char* output_file_name
) const
2158 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
2159 it
!= candidate_odr_violations_
.end();
2162 const char* symbol_name
= it
->first
;
2163 // We use a sorted set so the output is deterministic.
2164 std::set
<std::string
, Odr_violation_compare
> line_nums
;
2166 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
2167 locs
= it
->second
.begin();
2168 locs
!= it
->second
.end();
2171 // We need to lock the object in order to read it. This
2172 // means that we have to run in a singleton Task. If we
2173 // want to run this in a general Task for better
2174 // performance, we will need one Task for object, plus
2175 // appropriate locking to ensure that we don't conflict with
2176 // other uses of the object.
2177 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2178 std::string lineno
= Dwarf_line_info::one_addr2line(
2179 locs
->object
, locs
->shndx
, locs
->offset
);
2180 if (!lineno
.empty())
2181 line_nums
.insert(lineno
);
2184 if (line_nums
.size() > 1)
2186 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2187 "places (possible ODR violation):"),
2188 output_file_name
, demangle(symbol_name
).c_str());
2189 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2190 it2
!= line_nums
.end();
2192 fprintf(stderr
, " %s\n", it2
->c_str());
2197 // Warnings functions.
2199 // Add a new warning.
2202 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2203 const std::string
& warning
)
2205 name
= symtab
->canonicalize_name(name
);
2206 this->warnings_
[name
].set(obj
, warning
);
2209 // Look through the warnings and mark the symbols for which we should
2210 // warn. This is called during Layout::finalize when we know the
2211 // sources for all the symbols.
2214 Warnings::note_warnings(Symbol_table
* symtab
)
2216 for (Warning_table::iterator p
= this->warnings_
.begin();
2217 p
!= this->warnings_
.end();
2220 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2222 && sym
->source() == Symbol::FROM_OBJECT
2223 && sym
->object() == p
->second
.object
)
2224 sym
->set_has_warning();
2228 // Issue a warning. This is called when we see a relocation against a
2229 // symbol for which has a warning.
2231 template<int size
, bool big_endian
>
2233 Warnings::issue_warning(const Symbol
* sym
,
2234 const Relocate_info
<size
, big_endian
>* relinfo
,
2235 size_t relnum
, off_t reloffset
) const
2237 gold_assert(sym
->has_warning());
2238 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2239 gold_assert(p
!= this->warnings_
.end());
2240 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2241 "%s", p
->second
.text
.c_str());
2244 // Instantiate the templates we need. We could use the configure
2245 // script to restrict this to only the ones needed for implemented
2248 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2251 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2254 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2257 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2260 #ifdef HAVE_TARGET_32_LITTLE
2263 Symbol_table::add_from_relobj
<32, false>(
2264 Sized_relobj
<32, false>* relobj
,
2265 const unsigned char* syms
,
2267 const char* sym_names
,
2268 size_t sym_name_size
,
2269 Sized_relobj
<32, true>::Symbols
* sympointers
);
2272 #ifdef HAVE_TARGET_32_BIG
2275 Symbol_table::add_from_relobj
<32, true>(
2276 Sized_relobj
<32, true>* relobj
,
2277 const unsigned char* syms
,
2279 const char* sym_names
,
2280 size_t sym_name_size
,
2281 Sized_relobj
<32, false>::Symbols
* sympointers
);
2284 #ifdef HAVE_TARGET_64_LITTLE
2287 Symbol_table::add_from_relobj
<64, false>(
2288 Sized_relobj
<64, false>* relobj
,
2289 const unsigned char* syms
,
2291 const char* sym_names
,
2292 size_t sym_name_size
,
2293 Sized_relobj
<64, true>::Symbols
* sympointers
);
2296 #ifdef HAVE_TARGET_64_BIG
2299 Symbol_table::add_from_relobj
<64, true>(
2300 Sized_relobj
<64, true>* relobj
,
2301 const unsigned char* syms
,
2303 const char* sym_names
,
2304 size_t sym_name_size
,
2305 Sized_relobj
<64, false>::Symbols
* sympointers
);
2308 #ifdef HAVE_TARGET_32_LITTLE
2311 Symbol_table::add_from_dynobj
<32, false>(
2312 Sized_dynobj
<32, false>* dynobj
,
2313 const unsigned char* syms
,
2315 const char* sym_names
,
2316 size_t sym_name_size
,
2317 const unsigned char* versym
,
2319 const std::vector
<const char*>* version_map
);
2322 #ifdef HAVE_TARGET_32_BIG
2325 Symbol_table::add_from_dynobj
<32, true>(
2326 Sized_dynobj
<32, true>* dynobj
,
2327 const unsigned char* syms
,
2329 const char* sym_names
,
2330 size_t sym_name_size
,
2331 const unsigned char* versym
,
2333 const std::vector
<const char*>* version_map
);
2336 #ifdef HAVE_TARGET_64_LITTLE
2339 Symbol_table::add_from_dynobj
<64, false>(
2340 Sized_dynobj
<64, false>* dynobj
,
2341 const unsigned char* syms
,
2343 const char* sym_names
,
2344 size_t sym_name_size
,
2345 const unsigned char* versym
,
2347 const std::vector
<const char*>* version_map
);
2350 #ifdef HAVE_TARGET_64_BIG
2353 Symbol_table::add_from_dynobj
<64, true>(
2354 Sized_dynobj
<64, true>* dynobj
,
2355 const unsigned char* syms
,
2357 const char* sym_names
,
2358 size_t sym_name_size
,
2359 const unsigned char* versym
,
2361 const std::vector
<const char*>* version_map
);
2364 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2367 Symbol_table::define_with_copy_reloc
<32>(
2368 Sized_symbol
<32>* sym
,
2370 elfcpp::Elf_types
<32>::Elf_Addr value
);
2373 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2376 Symbol_table::define_with_copy_reloc
<64>(
2377 Sized_symbol
<64>* sym
,
2379 elfcpp::Elf_types
<64>::Elf_Addr value
);
2382 #ifdef HAVE_TARGET_32_LITTLE
2385 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
2386 const Relocate_info
<32, false>* relinfo
,
2387 size_t relnum
, off_t reloffset
) const;
2390 #ifdef HAVE_TARGET_32_BIG
2393 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
2394 const Relocate_info
<32, true>* relinfo
,
2395 size_t relnum
, off_t reloffset
) const;
2398 #ifdef HAVE_TARGET_64_LITTLE
2401 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
2402 const Relocate_info
<64, false>* relinfo
,
2403 size_t relnum
, off_t reloffset
) const;
2406 #ifdef HAVE_TARGET_64_BIG
2409 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
2410 const Relocate_info
<64, true>* relinfo
,
2411 size_t relnum
, off_t reloffset
) const;
2414 } // End namespace gold.