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 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
482 // is only called for undefined symbols, when at least one --wrap
486 Symbol_table::wrap_symbol(Object
* object
, const char* name
,
487 Stringpool::Key
* name_key
)
489 // For some targets, we need to ignore a specific character when
490 // wrapping, and add it back later.
492 if (name
[0] == object
->target()->wrap_char())
498 if (parameters
->options().is_wrap_symbol(name
))
500 // Turn NAME into __wrap_NAME.
507 // This will give us both the old and new name in NAMEPOOL_, but
508 // that is OK. Only the versions we need will wind up in the
509 // real string table in the output file.
510 return this->namepool_
.add(s
.c_str(), true, name_key
);
513 const char* const real_prefix
= "__real_";
514 const size_t real_prefix_length
= strlen(real_prefix
);
515 if (strncmp(name
, real_prefix
, real_prefix_length
) == 0
516 && parameters
->options().is_wrap_symbol(name
+ real_prefix_length
))
518 // Turn __real_NAME into NAME.
522 s
+= name
+ real_prefix_length
;
523 return this->namepool_
.add(s
.c_str(), true, name_key
);
529 // Add one symbol from OBJECT to the symbol table. NAME is symbol
530 // name and VERSION is the version; both are canonicalized. DEF is
531 // whether this is the default version.
533 // If DEF is true, then this is the definition of a default version of
534 // a symbol. That means that any lookup of NAME/NULL and any lookup
535 // of NAME/VERSION should always return the same symbol. This is
536 // obvious for references, but in particular we want to do this for
537 // definitions: overriding NAME/NULL should also override
538 // NAME/VERSION. If we don't do that, it would be very hard to
539 // override functions in a shared library which uses versioning.
541 // We implement this by simply making both entries in the hash table
542 // point to the same Symbol structure. That is easy enough if this is
543 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
544 // that we have seen both already, in which case they will both have
545 // independent entries in the symbol table. We can't simply change
546 // the symbol table entry, because we have pointers to the entries
547 // attached to the object files. So we mark the entry attached to the
548 // object file as a forwarder, and record it in the forwarders_ map.
549 // Note that entries in the hash table will never be marked as
552 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
553 // symbol exactly as it existed in the input file. SYM is usually
554 // that as well, but can be modified, for instance if we determine
555 // it's in a to-be-discarded section.
557 template<int size
, bool big_endian
>
559 Symbol_table::add_from_object(Object
* object
,
561 Stringpool::Key name_key
,
563 Stringpool::Key version_key
,
565 const elfcpp::Sym
<size
, big_endian
>& sym
,
566 const elfcpp::Sym
<size
, big_endian
>& orig_sym
)
568 // For an undefined symbol, we may need to adjust the name using
570 if (orig_sym
.get_st_shndx() == elfcpp::SHN_UNDEF
571 && parameters
->options().any_wrap_symbols())
573 const char* wrap_name
= this->wrap_symbol(object
, name
, &name_key
);
574 if (wrap_name
!= name
)
576 // If we see a reference to malloc with version GLIBC_2.0,
577 // and we turn it into a reference to __wrap_malloc, then we
578 // discard the version number. Otherwise the user would be
579 // required to specify the correct version for
587 Symbol
* const snull
= NULL
;
588 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
589 this->table_
.insert(std::make_pair(std::make_pair(name_key
, version_key
),
592 std::pair
<typename
Symbol_table_type::iterator
, bool> insdef
=
593 std::make_pair(this->table_
.end(), false);
596 const Stringpool::Key vnull_key
= 0;
597 insdef
= this->table_
.insert(std::make_pair(std::make_pair(name_key
,
602 // ins.first: an iterator, which is a pointer to a pair.
603 // ins.first->first: the key (a pair of name and version).
604 // ins.first->second: the value (Symbol*).
605 // ins.second: true if new entry was inserted, false if not.
607 Sized_symbol
<size
>* ret
;
612 // We already have an entry for NAME/VERSION.
613 ret
= this->get_sized_symbol
<size
>(ins
.first
->second
);
614 gold_assert(ret
!= NULL
);
616 was_undefined
= ret
->is_undefined();
617 was_common
= ret
->is_common();
619 this->resolve(ret
, sym
, orig_sym
, object
, version
);
625 // This is the first time we have seen NAME/NULL. Make
626 // NAME/NULL point to NAME/VERSION.
627 insdef
.first
->second
= ret
;
629 else if (insdef
.first
->second
!= ret
630 && insdef
.first
->second
->is_undefined())
632 // This is the unfortunate case where we already have
633 // entries for both NAME/VERSION and NAME/NULL. Note
634 // that we don't want to combine them if the existing
635 // symbol is going to override the new one. FIXME: We
636 // currently just test is_undefined, but this may not do
637 // the right thing if the existing symbol is from a
638 // shared library and the new one is from a regular
641 const Sized_symbol
<size
>* sym2
;
642 sym2
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
643 Symbol_table::resolve
<size
, big_endian
>(ret
, sym2
, version
);
644 this->make_forwarder(insdef
.first
->second
, ret
);
645 insdef
.first
->second
= ret
;
653 // This is the first time we have seen NAME/VERSION.
654 gold_assert(ins
.first
->second
== NULL
);
656 if (def
&& !insdef
.second
)
658 // We already have an entry for NAME/NULL. If we override
659 // it, then change it to NAME/VERSION.
660 ret
= this->get_sized_symbol
<size
>(insdef
.first
->second
);
662 was_undefined
= ret
->is_undefined();
663 was_common
= ret
->is_common();
665 this->resolve(ret
, sym
, orig_sym
, object
, version
);
666 ins
.first
->second
= ret
;
670 was_undefined
= false;
673 Sized_target
<size
, big_endian
>* target
=
674 object
->sized_target
<size
, big_endian
>();
675 if (!target
->has_make_symbol())
676 ret
= new Sized_symbol
<size
>();
679 ret
= target
->make_symbol();
682 // This means that we don't want a symbol table
685 this->table_
.erase(ins
.first
);
688 this->table_
.erase(insdef
.first
);
689 // Inserting insdef invalidated ins.
690 this->table_
.erase(std::make_pair(name_key
,
697 ret
->init(name
, version
, object
, sym
);
699 ins
.first
->second
= ret
;
702 // This is the first time we have seen NAME/NULL. Point
703 // it at the new entry for NAME/VERSION.
704 gold_assert(insdef
.second
);
705 insdef
.first
->second
= ret
;
710 // Record every time we see a new undefined symbol, to speed up
712 if (!was_undefined
&& ret
->is_undefined())
713 ++this->saw_undefined_
;
715 // Keep track of common symbols, to speed up common symbol
717 if (!was_common
&& ret
->is_common())
718 this->commons_
.push_back(ret
);
721 ret
->set_is_default();
725 // Add all the symbols in a relocatable object to the hash table.
727 template<int size
, bool big_endian
>
729 Symbol_table::add_from_relobj(
730 Sized_relobj
<size
, big_endian
>* relobj
,
731 const unsigned char* syms
,
733 const char* sym_names
,
734 size_t sym_name_size
,
735 typename Sized_relobj
<size
, big_endian
>::Symbols
* sympointers
)
737 gold_assert(size
== relobj
->target()->get_size());
738 gold_assert(size
== parameters
->target().get_size());
740 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
742 const bool just_symbols
= relobj
->just_symbols();
744 const unsigned char* p
= syms
;
745 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
)
747 elfcpp::Sym
<size
, big_endian
> sym(p
);
748 elfcpp::Sym
<size
, big_endian
>* psym
= &sym
;
750 unsigned int st_name
= psym
->get_st_name();
751 if (st_name
>= sym_name_size
)
753 relobj
->error(_("bad global symbol name offset %u at %zu"),
758 const char* name
= sym_names
+ st_name
;
760 // A symbol defined in a section which we are not including must
761 // be treated as an undefined symbol.
762 unsigned char symbuf
[sym_size
];
763 elfcpp::Sym
<size
, big_endian
> sym2(symbuf
);
764 unsigned int st_shndx
= psym
->get_st_shndx();
765 if (st_shndx
!= elfcpp::SHN_UNDEF
766 && st_shndx
< elfcpp::SHN_LORESERVE
767 && !relobj
->is_section_included(st_shndx
))
769 memcpy(symbuf
, p
, sym_size
);
770 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
771 sw
.put_st_shndx(elfcpp::SHN_UNDEF
);
775 // In an object file, an '@' in the name separates the symbol
776 // name from the version name. If there are two '@' characters,
777 // this is the default version.
778 const char* ver
= strchr(name
, '@');
780 // DEF: is the version default? LOCAL: is the symbol forced local?
786 // The symbol name is of the form foo@VERSION or foo@@VERSION
787 namelen
= ver
- name
;
795 // We don't want to assign a version to an undefined symbol,
796 // even if it is listed in the version script. FIXME: What
797 // about a common symbol?
798 else if (!version_script_
.empty()
799 && psym
->get_st_shndx() != elfcpp::SHN_UNDEF
)
801 // The symbol name did not have a version, but
802 // the version script may assign a version anyway.
803 namelen
= strlen(name
);
805 // Check the global: entries from the version script.
806 const std::string
& version
=
807 version_script_
.get_symbol_version(name
);
808 if (!version
.empty())
809 ver
= version
.c_str();
810 // Check the local: entries from the version script
811 if (version_script_
.symbol_is_local(name
))
818 memcpy(symbuf
, p
, sym_size
);
819 elfcpp::Sym_write
<size
, big_endian
> sw(symbuf
);
820 sw
.put_st_shndx(elfcpp::SHN_ABS
);
821 if (st_shndx
!= elfcpp::SHN_UNDEF
822 && st_shndx
< elfcpp::SHN_LORESERVE
)
824 // Symbol values in object files are section relative.
825 // This is normally what we want, but since here we are
826 // converting the symbol to absolute we need to add the
827 // section address. The section address in an object
828 // file is normally zero, but people can use a linker
829 // script to change it.
830 sw
.put_st_value(sym2
.get_st_value()
831 + relobj
->section_address(st_shndx
));
836 Sized_symbol
<size
>* res
;
839 Stringpool::Key name_key
;
840 name
= this->namepool_
.add(name
, true, &name_key
);
841 res
= this->add_from_object(relobj
, name
, name_key
, NULL
, 0,
844 this->force_local(res
);
848 Stringpool::Key name_key
;
849 name
= this->namepool_
.add_with_length(name
, namelen
, true,
851 Stringpool::Key ver_key
;
852 ver
= this->namepool_
.add(ver
, true, &ver_key
);
854 res
= this->add_from_object(relobj
, name
, name_key
, ver
, ver_key
,
858 (*sympointers
)[i
] = res
;
862 // Add all the symbols in a dynamic object to the hash table.
864 template<int size
, bool big_endian
>
866 Symbol_table::add_from_dynobj(
867 Sized_dynobj
<size
, big_endian
>* dynobj
,
868 const unsigned char* syms
,
870 const char* sym_names
,
871 size_t sym_name_size
,
872 const unsigned char* versym
,
874 const std::vector
<const char*>* version_map
)
876 gold_assert(size
== dynobj
->target()->get_size());
877 gold_assert(size
== parameters
->target().get_size());
879 if (dynobj
->just_symbols())
881 gold_error(_("--just-symbols does not make sense with a shared object"));
885 if (versym
!= NULL
&& versym_size
/ 2 < count
)
887 dynobj
->error(_("too few symbol versions"));
891 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
893 // We keep a list of all STT_OBJECT symbols, so that we can resolve
894 // weak aliases. This is necessary because if the dynamic object
895 // provides the same variable under two names, one of which is a
896 // weak definition, and the regular object refers to the weak
897 // definition, we have to put both the weak definition and the
898 // strong definition into the dynamic symbol table. Given a weak
899 // definition, the only way that we can find the corresponding
900 // strong definition, if any, is to search the symbol table.
901 std::vector
<Sized_symbol
<size
>*> object_symbols
;
903 const unsigned char* p
= syms
;
904 const unsigned char* vs
= versym
;
905 for (size_t i
= 0; i
< count
; ++i
, p
+= sym_size
, vs
+= 2)
907 elfcpp::Sym
<size
, big_endian
> sym(p
);
909 // Ignore symbols with local binding or that have
910 // internal or hidden visibility.
911 if (sym
.get_st_bind() == elfcpp::STB_LOCAL
912 || sym
.get_st_visibility() == elfcpp::STV_INTERNAL
913 || sym
.get_st_visibility() == elfcpp::STV_HIDDEN
)
916 unsigned int st_name
= sym
.get_st_name();
917 if (st_name
>= sym_name_size
)
919 dynobj
->error(_("bad symbol name offset %u at %zu"),
924 const char* name
= sym_names
+ st_name
;
926 Sized_symbol
<size
>* res
;
930 Stringpool::Key name_key
;
931 name
= this->namepool_
.add(name
, true, &name_key
);
932 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
937 // Read the version information.
939 unsigned int v
= elfcpp::Swap
<16, big_endian
>::readval(vs
);
941 bool hidden
= (v
& elfcpp::VERSYM_HIDDEN
) != 0;
942 v
&= elfcpp::VERSYM_VERSION
;
944 // The Sun documentation says that V can be VER_NDX_LOCAL,
945 // or VER_NDX_GLOBAL, or a version index. The meaning of
946 // VER_NDX_LOCAL is defined as "Symbol has local scope."
947 // The old GNU linker will happily generate VER_NDX_LOCAL
948 // for an undefined symbol. I don't know what the Sun
949 // linker will generate.
951 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
952 && sym
.get_st_shndx() != elfcpp::SHN_UNDEF
)
954 // This symbol should not be visible outside the object.
958 // At this point we are definitely going to add this symbol.
959 Stringpool::Key name_key
;
960 name
= this->namepool_
.add(name
, true, &name_key
);
962 if (v
== static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL
)
963 || v
== static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL
))
965 // This symbol does not have a version.
966 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
971 if (v
>= version_map
->size())
973 dynobj
->error(_("versym for symbol %zu out of range: %u"),
978 const char* version
= (*version_map
)[v
];
981 dynobj
->error(_("versym for symbol %zu has no name: %u"),
986 Stringpool::Key version_key
;
987 version
= this->namepool_
.add(version
, true, &version_key
);
989 // If this is an absolute symbol, and the version name
990 // and symbol name are the same, then this is the
991 // version definition symbol. These symbols exist to
992 // support using -u to pull in particular versions. We
993 // do not want to record a version for them.
994 if (sym
.get_st_shndx() == elfcpp::SHN_ABS
995 && name_key
== version_key
)
996 res
= this->add_from_object(dynobj
, name
, name_key
, NULL
, 0,
1000 const bool def
= (!hidden
1001 && (sym
.get_st_shndx()
1002 != elfcpp::SHN_UNDEF
));
1003 res
= this->add_from_object(dynobj
, name
, name_key
, version
,
1004 version_key
, def
, sym
, sym
);
1009 if (sym
.get_st_shndx() != elfcpp::SHN_UNDEF
1010 && sym
.get_st_type() == elfcpp::STT_OBJECT
)
1011 object_symbols
.push_back(res
);
1014 this->record_weak_aliases(&object_symbols
);
1017 // This is used to sort weak aliases. We sort them first by section
1018 // index, then by offset, then by weak ahead of strong.
1021 class Weak_alias_sorter
1024 bool operator()(const Sized_symbol
<size
>*, const Sized_symbol
<size
>*) const;
1029 Weak_alias_sorter
<size
>::operator()(const Sized_symbol
<size
>* s1
,
1030 const Sized_symbol
<size
>* s2
) const
1032 if (s1
->shndx() != s2
->shndx())
1033 return s1
->shndx() < s2
->shndx();
1034 if (s1
->value() != s2
->value())
1035 return s1
->value() < s2
->value();
1036 if (s1
->binding() != s2
->binding())
1038 if (s1
->binding() == elfcpp::STB_WEAK
)
1040 if (s2
->binding() == elfcpp::STB_WEAK
)
1043 return std::string(s1
->name()) < std::string(s2
->name());
1046 // SYMBOLS is a list of object symbols from a dynamic object. Look
1047 // for any weak aliases, and record them so that if we add the weak
1048 // alias to the dynamic symbol table, we also add the corresponding
1053 Symbol_table::record_weak_aliases(std::vector
<Sized_symbol
<size
>*>* symbols
)
1055 // Sort the vector by section index, then by offset, then by weak
1057 std::sort(symbols
->begin(), symbols
->end(), Weak_alias_sorter
<size
>());
1059 // Walk through the vector. For each weak definition, record
1061 for (typename
std::vector
<Sized_symbol
<size
>*>::const_iterator p
=
1063 p
!= symbols
->end();
1066 if ((*p
)->binding() != elfcpp::STB_WEAK
)
1069 // Build a circular list of weak aliases. Each symbol points to
1070 // the next one in the circular list.
1072 Sized_symbol
<size
>* from_sym
= *p
;
1073 typename
std::vector
<Sized_symbol
<size
>*>::const_iterator q
;
1074 for (q
= p
+ 1; q
!= symbols
->end(); ++q
)
1076 if ((*q
)->shndx() != from_sym
->shndx()
1077 || (*q
)->value() != from_sym
->value())
1080 this->weak_aliases_
[from_sym
] = *q
;
1081 from_sym
->set_has_alias();
1087 this->weak_aliases_
[from_sym
] = *p
;
1088 from_sym
->set_has_alias();
1095 // Create and return a specially defined symbol. If ONLY_IF_REF is
1096 // true, then only create the symbol if there is a reference to it.
1097 // If this does not return NULL, it sets *POLDSYM to the existing
1098 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1100 template<int size
, bool big_endian
>
1102 Symbol_table::define_special_symbol(const char** pname
, const char** pversion
,
1104 Sized_symbol
<size
>** poldsym
)
1107 Sized_symbol
<size
>* sym
;
1108 bool add_to_table
= false;
1109 typename
Symbol_table_type::iterator add_loc
= this->table_
.end();
1111 // If the caller didn't give us a version, see if we get one from
1112 // the version script.
1113 if (*pversion
== NULL
)
1115 const std::string
& v(this->version_script_
.get_symbol_version(*pname
));
1117 *pversion
= v
.c_str();
1122 oldsym
= this->lookup(*pname
, *pversion
);
1123 if (oldsym
== NULL
|| !oldsym
->is_undefined())
1126 *pname
= oldsym
->name();
1127 *pversion
= oldsym
->version();
1131 // Canonicalize NAME and VERSION.
1132 Stringpool::Key name_key
;
1133 *pname
= this->namepool_
.add(*pname
, true, &name_key
);
1135 Stringpool::Key version_key
= 0;
1136 if (*pversion
!= NULL
)
1137 *pversion
= this->namepool_
.add(*pversion
, true, &version_key
);
1139 Symbol
* const snull
= NULL
;
1140 std::pair
<typename
Symbol_table_type::iterator
, bool> ins
=
1141 this->table_
.insert(std::make_pair(std::make_pair(name_key
,
1147 // We already have a symbol table entry for NAME/VERSION.
1148 oldsym
= ins
.first
->second
;
1149 gold_assert(oldsym
!= NULL
);
1153 // We haven't seen this symbol before.
1154 gold_assert(ins
.first
->second
== NULL
);
1155 add_to_table
= true;
1156 add_loc
= ins
.first
;
1161 const Target
& target
= parameters
->target();
1162 if (!target
.has_make_symbol())
1163 sym
= new Sized_symbol
<size
>();
1166 gold_assert(target
.get_size() == size
);
1167 gold_assert(target
.is_big_endian() ? big_endian
: !big_endian
);
1168 typedef Sized_target
<size
, big_endian
> My_target
;
1169 const My_target
* sized_target
=
1170 static_cast<const My_target
*>(&target
);
1171 sym
= sized_target
->make_symbol();
1177 add_loc
->second
= sym
;
1179 gold_assert(oldsym
!= NULL
);
1181 *poldsym
= this->get_sized_symbol
<size
>(oldsym
);
1186 // Define a symbol based on an Output_data.
1189 Symbol_table::define_in_output_data(const char* name
,
1190 const char* version
,
1195 elfcpp::STB binding
,
1196 elfcpp::STV visibility
,
1197 unsigned char nonvis
,
1198 bool offset_is_from_end
,
1201 if (parameters
->target().get_size() == 32)
1203 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1204 return this->do_define_in_output_data
<32>(name
, version
, od
,
1205 value
, symsize
, type
, binding
,
1213 else if (parameters
->target().get_size() == 64)
1215 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1216 return this->do_define_in_output_data
<64>(name
, version
, od
,
1217 value
, symsize
, type
, binding
,
1229 // Define a symbol in an Output_data, sized version.
1233 Symbol_table::do_define_in_output_data(
1235 const char* version
,
1237 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1238 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1240 elfcpp::STB binding
,
1241 elfcpp::STV visibility
,
1242 unsigned char nonvis
,
1243 bool offset_is_from_end
,
1246 Sized_symbol
<size
>* sym
;
1247 Sized_symbol
<size
>* oldsym
;
1249 if (parameters
->target().is_big_endian())
1251 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1252 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1253 only_if_ref
, &oldsym
);
1260 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1261 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1262 only_if_ref
, &oldsym
);
1271 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1272 sym
->init(name
, od
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1273 offset_is_from_end
);
1277 if (binding
== elfcpp::STB_LOCAL
1278 || this->version_script_
.symbol_is_local(name
))
1279 this->force_local(sym
);
1283 if (Symbol_table::should_override_with_special(oldsym
))
1284 this->override_with_special(oldsym
, sym
);
1289 // Define a symbol based on an Output_segment.
1292 Symbol_table::define_in_output_segment(const char* name
,
1293 const char* version
, Output_segment
* os
,
1297 elfcpp::STB binding
,
1298 elfcpp::STV visibility
,
1299 unsigned char nonvis
,
1300 Symbol::Segment_offset_base offset_base
,
1303 if (parameters
->target().get_size() == 32)
1305 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1306 return this->do_define_in_output_segment
<32>(name
, version
, os
,
1307 value
, symsize
, type
,
1308 binding
, visibility
, nonvis
,
1309 offset_base
, only_if_ref
);
1314 else if (parameters
->target().get_size() == 64)
1316 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1317 return this->do_define_in_output_segment
<64>(name
, version
, os
,
1318 value
, symsize
, type
,
1319 binding
, visibility
, nonvis
,
1320 offset_base
, only_if_ref
);
1329 // Define a symbol in an Output_segment, sized version.
1333 Symbol_table::do_define_in_output_segment(
1335 const char* version
,
1337 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1338 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1340 elfcpp::STB binding
,
1341 elfcpp::STV visibility
,
1342 unsigned char nonvis
,
1343 Symbol::Segment_offset_base offset_base
,
1346 Sized_symbol
<size
>* sym
;
1347 Sized_symbol
<size
>* oldsym
;
1349 if (parameters
->target().is_big_endian())
1351 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1352 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1353 only_if_ref
, &oldsym
);
1360 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1361 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1362 only_if_ref
, &oldsym
);
1371 gold_assert(version
== NULL
|| oldsym
!= NULL
);
1372 sym
->init(name
, os
, value
, symsize
, type
, binding
, visibility
, nonvis
,
1377 if (binding
== elfcpp::STB_LOCAL
1378 || this->version_script_
.symbol_is_local(name
))
1379 this->force_local(sym
);
1383 if (Symbol_table::should_override_with_special(oldsym
))
1384 this->override_with_special(oldsym
, sym
);
1389 // Define a special symbol with a constant value. It is a multiple
1390 // definition error if this symbol is already defined.
1393 Symbol_table::define_as_constant(const char* name
,
1394 const char* version
,
1398 elfcpp::STB binding
,
1399 elfcpp::STV visibility
,
1400 unsigned char nonvis
,
1402 bool force_override
)
1404 if (parameters
->target().get_size() == 32)
1406 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1407 return this->do_define_as_constant
<32>(name
, version
, value
,
1408 symsize
, type
, binding
,
1409 visibility
, nonvis
, only_if_ref
,
1415 else if (parameters
->target().get_size() == 64)
1417 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1418 return this->do_define_as_constant
<64>(name
, version
, value
,
1419 symsize
, type
, binding
,
1420 visibility
, nonvis
, only_if_ref
,
1430 // Define a symbol as a constant, sized version.
1434 Symbol_table::do_define_as_constant(
1436 const char* version
,
1437 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
1438 typename
elfcpp::Elf_types
<size
>::Elf_WXword symsize
,
1440 elfcpp::STB binding
,
1441 elfcpp::STV visibility
,
1442 unsigned char nonvis
,
1444 bool force_override
)
1446 Sized_symbol
<size
>* sym
;
1447 Sized_symbol
<size
>* oldsym
;
1449 if (parameters
->target().is_big_endian())
1451 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1452 sym
= this->define_special_symbol
<size
, true>(&name
, &version
,
1453 only_if_ref
, &oldsym
);
1460 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1461 sym
= this->define_special_symbol
<size
, false>(&name
, &version
,
1462 only_if_ref
, &oldsym
);
1471 gold_assert(version
== NULL
|| version
== name
|| oldsym
!= NULL
);
1472 sym
->init(name
, value
, symsize
, type
, binding
, visibility
, nonvis
);
1476 // Version symbols are absolute symbols with name == version.
1477 // We don't want to force them to be local.
1478 if ((version
== NULL
1481 && (binding
== elfcpp::STB_LOCAL
1482 || this->version_script_
.symbol_is_local(name
)))
1483 this->force_local(sym
);
1487 if (force_override
|| Symbol_table::should_override_with_special(oldsym
))
1488 this->override_with_special(oldsym
, sym
);
1493 // Define a set of symbols in output sections.
1496 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1497 const Define_symbol_in_section
* p
,
1500 for (int i
= 0; i
< count
; ++i
, ++p
)
1502 Output_section
* os
= layout
->find_output_section(p
->output_section
);
1504 this->define_in_output_data(p
->name
, NULL
, os
, p
->value
,
1505 p
->size
, p
->type
, p
->binding
,
1506 p
->visibility
, p
->nonvis
,
1507 p
->offset_is_from_end
,
1508 only_if_ref
|| p
->only_if_ref
);
1510 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1511 p
->binding
, p
->visibility
, p
->nonvis
,
1512 only_if_ref
|| p
->only_if_ref
,
1517 // Define a set of symbols in output segments.
1520 Symbol_table::define_symbols(const Layout
* layout
, int count
,
1521 const Define_symbol_in_segment
* p
,
1524 for (int i
= 0; i
< count
; ++i
, ++p
)
1526 Output_segment
* os
= layout
->find_output_segment(p
->segment_type
,
1527 p
->segment_flags_set
,
1528 p
->segment_flags_clear
);
1530 this->define_in_output_segment(p
->name
, NULL
, os
, p
->value
,
1531 p
->size
, p
->type
, p
->binding
,
1532 p
->visibility
, p
->nonvis
,
1534 only_if_ref
|| p
->only_if_ref
);
1536 this->define_as_constant(p
->name
, NULL
, 0, p
->size
, p
->type
,
1537 p
->binding
, p
->visibility
, p
->nonvis
,
1538 only_if_ref
|| p
->only_if_ref
,
1543 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1544 // symbol should be defined--typically a .dyn.bss section. VALUE is
1545 // the offset within POSD.
1549 Symbol_table::define_with_copy_reloc(
1550 Sized_symbol
<size
>* csym
,
1552 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
)
1554 gold_assert(csym
->is_from_dynobj());
1555 gold_assert(!csym
->is_copied_from_dynobj());
1556 Object
* object
= csym
->object();
1557 gold_assert(object
->is_dynamic());
1558 Dynobj
* dynobj
= static_cast<Dynobj
*>(object
);
1560 // Our copied variable has to override any variable in a shared
1562 elfcpp::STB binding
= csym
->binding();
1563 if (binding
== elfcpp::STB_WEAK
)
1564 binding
= elfcpp::STB_GLOBAL
;
1566 this->define_in_output_data(csym
->name(), csym
->version(),
1567 posd
, value
, csym
->symsize(),
1568 csym
->type(), binding
,
1569 csym
->visibility(), csym
->nonvis(),
1572 csym
->set_is_copied_from_dynobj();
1573 csym
->set_needs_dynsym_entry();
1575 this->copied_symbol_dynobjs_
[csym
] = dynobj
;
1577 // We have now defined all aliases, but we have not entered them all
1578 // in the copied_symbol_dynobjs_ map.
1579 if (csym
->has_alias())
1584 sym
= this->weak_aliases_
[sym
];
1587 gold_assert(sym
->output_data() == posd
);
1589 sym
->set_is_copied_from_dynobj();
1590 this->copied_symbol_dynobjs_
[sym
] = dynobj
;
1595 // SYM is defined using a COPY reloc. Return the dynamic object where
1596 // the original definition was found.
1599 Symbol_table::get_copy_source(const Symbol
* sym
) const
1601 gold_assert(sym
->is_copied_from_dynobj());
1602 Copied_symbol_dynobjs::const_iterator p
=
1603 this->copied_symbol_dynobjs_
.find(sym
);
1604 gold_assert(p
!= this->copied_symbol_dynobjs_
.end());
1608 // Set the dynamic symbol indexes. INDEX is the index of the first
1609 // global dynamic symbol. Pointers to the symbols are stored into the
1610 // vector SYMS. The names are added to DYNPOOL. This returns an
1611 // updated dynamic symbol index.
1614 Symbol_table::set_dynsym_indexes(unsigned int index
,
1615 std::vector
<Symbol
*>* syms
,
1616 Stringpool
* dynpool
,
1619 for (Symbol_table_type::iterator p
= this->table_
.begin();
1620 p
!= this->table_
.end();
1623 Symbol
* sym
= p
->second
;
1625 // Note that SYM may already have a dynamic symbol index, since
1626 // some symbols appear more than once in the symbol table, with
1627 // and without a version.
1629 if (!sym
->should_add_dynsym_entry())
1630 sym
->set_dynsym_index(-1U);
1631 else if (!sym
->has_dynsym_index())
1633 sym
->set_dynsym_index(index
);
1635 syms
->push_back(sym
);
1636 dynpool
->add(sym
->name(), false, NULL
);
1638 // Record any version information.
1639 if (sym
->version() != NULL
)
1640 versions
->record_version(this, dynpool
, sym
);
1644 // Finish up the versions. In some cases this may add new dynamic
1646 index
= versions
->finalize(this, index
, syms
);
1651 // Set the final values for all the symbols. The index of the first
1652 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1653 // file offset OFF. Add their names to POOL. Return the new file
1654 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1657 Symbol_table::finalize(off_t off
, off_t dynoff
, size_t dyn_global_index
,
1658 size_t dyncount
, Stringpool
* pool
,
1659 unsigned int *plocal_symcount
)
1663 gold_assert(*plocal_symcount
!= 0);
1664 this->first_global_index_
= *plocal_symcount
;
1666 this->dynamic_offset_
= dynoff
;
1667 this->first_dynamic_global_index_
= dyn_global_index
;
1668 this->dynamic_count_
= dyncount
;
1670 if (parameters
->target().get_size() == 32)
1672 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1673 ret
= this->sized_finalize
<32>(off
, pool
, plocal_symcount
);
1678 else if (parameters
->target().get_size() == 64)
1680 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1681 ret
= this->sized_finalize
<64>(off
, pool
, plocal_symcount
);
1689 // Now that we have the final symbol table, we can reliably note
1690 // which symbols should get warnings.
1691 this->warnings_
.note_warnings(this);
1696 // SYM is going into the symbol table at *PINDEX. Add the name to
1697 // POOL, update *PINDEX and *POFF.
1701 Symbol_table::add_to_final_symtab(Symbol
* sym
, Stringpool
* pool
,
1702 unsigned int* pindex
, off_t
* poff
)
1704 sym
->set_symtab_index(*pindex
);
1705 pool
->add(sym
->name(), false, NULL
);
1707 *poff
+= elfcpp::Elf_sizes
<size
>::sym_size
;
1710 // Set the final value for all the symbols. This is called after
1711 // Layout::finalize, so all the output sections have their final
1716 Symbol_table::sized_finalize(off_t off
, Stringpool
* pool
,
1717 unsigned int* plocal_symcount
)
1719 off
= align_address(off
, size
>> 3);
1720 this->offset_
= off
;
1722 unsigned int index
= *plocal_symcount
;
1723 const unsigned int orig_index
= index
;
1725 // First do all the symbols which have been forced to be local, as
1726 // they must appear before all global symbols.
1727 for (Forced_locals::iterator p
= this->forced_locals_
.begin();
1728 p
!= this->forced_locals_
.end();
1732 gold_assert(sym
->is_forced_local());
1733 if (this->sized_finalize_symbol
<size
>(sym
))
1735 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1740 // Now do all the remaining symbols.
1741 for (Symbol_table_type::iterator p
= this->table_
.begin();
1742 p
!= this->table_
.end();
1745 Symbol
* sym
= p
->second
;
1746 if (this->sized_finalize_symbol
<size
>(sym
))
1747 this->add_to_final_symtab
<size
>(sym
, pool
, &index
, &off
);
1750 this->output_count_
= index
- orig_index
;
1755 // Finalize the symbol SYM. This returns true if the symbol should be
1756 // added to the symbol table, false otherwise.
1760 Symbol_table::sized_finalize_symbol(Symbol
* unsized_sym
)
1762 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(unsized_sym
);
1764 // The default version of a symbol may appear twice in the symbol
1765 // table. We only need to finalize it once.
1766 if (sym
->has_symtab_index())
1771 gold_assert(!sym
->has_symtab_index());
1772 sym
->set_symtab_index(-1U);
1773 gold_assert(sym
->dynsym_index() == -1U);
1777 typename Sized_symbol
<size
>::Value_type value
;
1779 switch (sym
->source())
1781 case Symbol::FROM_OBJECT
:
1783 unsigned int shndx
= sym
->shndx();
1785 // FIXME: We need some target specific support here.
1786 if (shndx
>= elfcpp::SHN_LORESERVE
1787 && shndx
!= elfcpp::SHN_ABS
1788 && shndx
!= elfcpp::SHN_COMMON
)
1790 gold_error(_("%s: unsupported symbol section 0x%x"),
1791 sym
->demangled_name().c_str(), shndx
);
1792 shndx
= elfcpp::SHN_UNDEF
;
1795 Object
* symobj
= sym
->object();
1796 if (symobj
->is_dynamic())
1799 shndx
= elfcpp::SHN_UNDEF
;
1801 else if (shndx
== elfcpp::SHN_UNDEF
)
1803 else if (shndx
== elfcpp::SHN_ABS
|| shndx
== elfcpp::SHN_COMMON
)
1804 value
= sym
->value();
1807 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
1808 section_offset_type secoff
;
1809 Output_section
* os
= relobj
->output_section(shndx
, &secoff
);
1813 sym
->set_symtab_index(-1U);
1814 gold_assert(sym
->dynsym_index() == -1U);
1818 if (sym
->type() == elfcpp::STT_TLS
)
1819 value
= sym
->value() + os
->tls_offset() + secoff
;
1821 value
= sym
->value() + os
->address() + secoff
;
1826 case Symbol::IN_OUTPUT_DATA
:
1828 Output_data
* od
= sym
->output_data();
1829 value
= sym
->value() + od
->address();
1830 if (sym
->offset_is_from_end())
1831 value
+= od
->data_size();
1835 case Symbol::IN_OUTPUT_SEGMENT
:
1837 Output_segment
* os
= sym
->output_segment();
1838 value
= sym
->value() + os
->vaddr();
1839 switch (sym
->offset_base())
1841 case Symbol::SEGMENT_START
:
1843 case Symbol::SEGMENT_END
:
1844 value
+= os
->memsz();
1846 case Symbol::SEGMENT_BSS
:
1847 value
+= os
->filesz();
1855 case Symbol::CONSTANT
:
1856 value
= sym
->value();
1863 sym
->set_value(value
);
1865 if (parameters
->options().strip_all())
1867 sym
->set_symtab_index(-1U);
1874 // Write out the global symbols.
1877 Symbol_table::write_globals(const Input_objects
* input_objects
,
1878 const Stringpool
* sympool
,
1879 const Stringpool
* dynpool
, Output_file
* of
) const
1881 switch (parameters
->size_and_endianness())
1883 #ifdef HAVE_TARGET_32_LITTLE
1884 case Parameters::TARGET_32_LITTLE
:
1885 this->sized_write_globals
<32, false>(input_objects
, sympool
,
1889 #ifdef HAVE_TARGET_32_BIG
1890 case Parameters::TARGET_32_BIG
:
1891 this->sized_write_globals
<32, true>(input_objects
, sympool
,
1895 #ifdef HAVE_TARGET_64_LITTLE
1896 case Parameters::TARGET_64_LITTLE
:
1897 this->sized_write_globals
<64, false>(input_objects
, sympool
,
1901 #ifdef HAVE_TARGET_64_BIG
1902 case Parameters::TARGET_64_BIG
:
1903 this->sized_write_globals
<64, true>(input_objects
, sympool
,
1912 // Write out the global symbols.
1914 template<int size
, bool big_endian
>
1916 Symbol_table::sized_write_globals(const Input_objects
* input_objects
,
1917 const Stringpool
* sympool
,
1918 const Stringpool
* dynpool
,
1919 Output_file
* of
) const
1921 const Target
& target
= parameters
->target();
1923 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
1925 const unsigned int output_count
= this->output_count_
;
1926 const section_size_type oview_size
= output_count
* sym_size
;
1927 const unsigned int first_global_index
= this->first_global_index_
;
1928 unsigned char* psyms
;
1929 if (this->offset_
== 0 || output_count
== 0)
1932 psyms
= of
->get_output_view(this->offset_
, oview_size
);
1934 const unsigned int dynamic_count
= this->dynamic_count_
;
1935 const section_size_type dynamic_size
= dynamic_count
* sym_size
;
1936 const unsigned int first_dynamic_global_index
=
1937 this->first_dynamic_global_index_
;
1938 unsigned char* dynamic_view
;
1939 if (this->dynamic_offset_
== 0 || dynamic_count
== 0)
1940 dynamic_view
= NULL
;
1942 dynamic_view
= of
->get_output_view(this->dynamic_offset_
, dynamic_size
);
1944 for (Symbol_table_type::const_iterator p
= this->table_
.begin();
1945 p
!= this->table_
.end();
1948 Sized_symbol
<size
>* sym
= static_cast<Sized_symbol
<size
>*>(p
->second
);
1950 // Possibly warn about unresolved symbols in shared libraries.
1951 this->warn_about_undefined_dynobj_symbol(input_objects
, sym
);
1953 unsigned int sym_index
= sym
->symtab_index();
1954 unsigned int dynsym_index
;
1955 if (dynamic_view
== NULL
)
1958 dynsym_index
= sym
->dynsym_index();
1960 if (sym_index
== -1U && dynsym_index
== -1U)
1962 // This symbol is not included in the output file.
1967 typename
elfcpp::Elf_types
<size
>::Elf_Addr sym_value
= sym
->value();
1968 typename
elfcpp::Elf_types
<size
>::Elf_Addr dynsym_value
= sym_value
;
1969 switch (sym
->source())
1971 case Symbol::FROM_OBJECT
:
1973 unsigned int in_shndx
= sym
->shndx();
1975 // FIXME: We need some target specific support here.
1976 if (in_shndx
>= elfcpp::SHN_LORESERVE
1977 && in_shndx
!= elfcpp::SHN_ABS
1978 && in_shndx
!= elfcpp::SHN_COMMON
)
1980 gold_error(_("%s: unsupported symbol section 0x%x"),
1981 sym
->demangled_name().c_str(), in_shndx
);
1986 Object
* symobj
= sym
->object();
1987 if (symobj
->is_dynamic())
1989 if (sym
->needs_dynsym_value())
1990 dynsym_value
= target
.dynsym_value(sym
);
1991 shndx
= elfcpp::SHN_UNDEF
;
1993 else if (in_shndx
== elfcpp::SHN_UNDEF
1994 || in_shndx
== elfcpp::SHN_ABS
1995 || in_shndx
== elfcpp::SHN_COMMON
)
1999 Relobj
* relobj
= static_cast<Relobj
*>(symobj
);
2000 section_offset_type secoff
;
2001 Output_section
* os
= relobj
->output_section(in_shndx
,
2003 gold_assert(os
!= NULL
);
2004 shndx
= os
->out_shndx();
2006 // In object files symbol values are section
2008 if (parameters
->options().relocatable())
2009 sym_value
-= os
->address();
2015 case Symbol::IN_OUTPUT_DATA
:
2016 shndx
= sym
->output_data()->out_shndx();
2019 case Symbol::IN_OUTPUT_SEGMENT
:
2020 shndx
= elfcpp::SHN_ABS
;
2023 case Symbol::CONSTANT
:
2024 shndx
= elfcpp::SHN_ABS
;
2031 if (sym_index
!= -1U)
2033 sym_index
-= first_global_index
;
2034 gold_assert(sym_index
< output_count
);
2035 unsigned char* ps
= psyms
+ (sym_index
* sym_size
);
2036 this->sized_write_symbol
<size
, big_endian
>(sym
, sym_value
, shndx
,
2040 if (dynsym_index
!= -1U)
2042 dynsym_index
-= first_dynamic_global_index
;
2043 gold_assert(dynsym_index
< dynamic_count
);
2044 unsigned char* pd
= dynamic_view
+ (dynsym_index
* sym_size
);
2045 this->sized_write_symbol
<size
, big_endian
>(sym
, dynsym_value
, shndx
,
2050 of
->write_output_view(this->offset_
, oview_size
, psyms
);
2051 if (dynamic_view
!= NULL
)
2052 of
->write_output_view(this->dynamic_offset_
, dynamic_size
, dynamic_view
);
2055 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2056 // strtab holding the name.
2058 template<int size
, bool big_endian
>
2060 Symbol_table::sized_write_symbol(
2061 Sized_symbol
<size
>* sym
,
2062 typename
elfcpp::Elf_types
<size
>::Elf_Addr value
,
2064 const Stringpool
* pool
,
2065 unsigned char* p
) const
2067 elfcpp::Sym_write
<size
, big_endian
> osym(p
);
2068 osym
.put_st_name(pool
->get_offset(sym
->name()));
2069 osym
.put_st_value(value
);
2070 osym
.put_st_size(sym
->symsize());
2071 // A version script may have overridden the default binding.
2072 if (sym
->is_forced_local())
2073 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
, sym
->type()));
2075 osym
.put_st_info(elfcpp::elf_st_info(sym
->binding(), sym
->type()));
2076 osym
.put_st_other(elfcpp::elf_st_other(sym
->visibility(), sym
->nonvis()));
2077 osym
.put_st_shndx(shndx
);
2080 // Check for unresolved symbols in shared libraries. This is
2081 // controlled by the --allow-shlib-undefined option.
2083 // We only warn about libraries for which we have seen all the
2084 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2085 // which were not seen in this link. If we didn't see a DT_NEEDED
2086 // entry, we aren't going to be able to reliably report whether the
2087 // symbol is undefined.
2089 // We also don't warn about libraries found in the system library
2090 // directory (the directory were we find libc.so); we assume that
2091 // those libraries are OK. This heuristic avoids problems in
2092 // GNU/Linux, in which -ldl can have undefined references satisfied by
2096 Symbol_table::warn_about_undefined_dynobj_symbol(
2097 const Input_objects
* input_objects
,
2100 if (sym
->source() == Symbol::FROM_OBJECT
2101 && sym
->object()->is_dynamic()
2102 && sym
->shndx() == elfcpp::SHN_UNDEF
2103 && sym
->binding() != elfcpp::STB_WEAK
2104 && !parameters
->options().allow_shlib_undefined()
2105 && !parameters
->target().is_defined_by_abi(sym
)
2106 && !input_objects
->found_in_system_library_directory(sym
->object()))
2108 // A very ugly cast.
2109 Dynobj
* dynobj
= static_cast<Dynobj
*>(sym
->object());
2110 if (!dynobj
->has_unknown_needed_entries())
2111 gold_error(_("%s: undefined reference to '%s'"),
2112 sym
->object()->name().c_str(),
2113 sym
->demangled_name().c_str());
2117 // Write out a section symbol. Return the update offset.
2120 Symbol_table::write_section_symbol(const Output_section
*os
,
2124 switch (parameters
->size_and_endianness())
2126 #ifdef HAVE_TARGET_32_LITTLE
2127 case Parameters::TARGET_32_LITTLE
:
2128 this->sized_write_section_symbol
<32, false>(os
, of
, offset
);
2131 #ifdef HAVE_TARGET_32_BIG
2132 case Parameters::TARGET_32_BIG
:
2133 this->sized_write_section_symbol
<32, true>(os
, of
, offset
);
2136 #ifdef HAVE_TARGET_64_LITTLE
2137 case Parameters::TARGET_64_LITTLE
:
2138 this->sized_write_section_symbol
<64, false>(os
, of
, offset
);
2141 #ifdef HAVE_TARGET_64_BIG
2142 case Parameters::TARGET_64_BIG
:
2143 this->sized_write_section_symbol
<64, true>(os
, of
, offset
);
2151 // Write out a section symbol, specialized for size and endianness.
2153 template<int size
, bool big_endian
>
2155 Symbol_table::sized_write_section_symbol(const Output_section
* os
,
2159 const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
2161 unsigned char* pov
= of
->get_output_view(offset
, sym_size
);
2163 elfcpp::Sym_write
<size
, big_endian
> osym(pov
);
2164 osym
.put_st_name(0);
2165 osym
.put_st_value(os
->address());
2166 osym
.put_st_size(0);
2167 osym
.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL
,
2168 elfcpp::STT_SECTION
));
2169 osym
.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT
, 0));
2170 osym
.put_st_shndx(os
->out_shndx());
2172 of
->write_output_view(offset
, sym_size
, pov
);
2175 // Print statistical information to stderr. This is used for --stats.
2178 Symbol_table::print_stats() const
2180 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2181 fprintf(stderr
, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2182 program_name
, this->table_
.size(), this->table_
.bucket_count());
2184 fprintf(stderr
, _("%s: symbol table entries: %zu\n"),
2185 program_name
, this->table_
.size());
2187 this->namepool_
.print_stats("symbol table stringpool");
2190 // We check for ODR violations by looking for symbols with the same
2191 // name for which the debugging information reports that they were
2192 // defined in different source locations. When comparing the source
2193 // location, we consider instances with the same base filename and
2194 // line number to be the same. This is because different object
2195 // files/shared libraries can include the same header file using
2196 // different paths, and we don't want to report an ODR violation in
2199 // This struct is used to compare line information, as returned by
2200 // Dwarf_line_info::one_addr2line. It implements a < comparison
2201 // operator used with std::set.
2203 struct Odr_violation_compare
2206 operator()(const std::string
& s1
, const std::string
& s2
) const
2208 std::string::size_type pos1
= s1
.rfind('/');
2209 std::string::size_type pos2
= s2
.rfind('/');
2210 if (pos1
== std::string::npos
2211 || pos2
== std::string::npos
)
2213 return s1
.compare(pos1
, std::string::npos
,
2214 s2
, pos2
, std::string::npos
) < 0;
2218 // Check candidate_odr_violations_ to find symbols with the same name
2219 // but apparently different definitions (different source-file/line-no).
2222 Symbol_table::detect_odr_violations(const Task
* task
,
2223 const char* output_file_name
) const
2225 for (Odr_map::const_iterator it
= candidate_odr_violations_
.begin();
2226 it
!= candidate_odr_violations_
.end();
2229 const char* symbol_name
= it
->first
;
2230 // We use a sorted set so the output is deterministic.
2231 std::set
<std::string
, Odr_violation_compare
> line_nums
;
2233 for (Unordered_set
<Symbol_location
, Symbol_location_hash
>::const_iterator
2234 locs
= it
->second
.begin();
2235 locs
!= it
->second
.end();
2238 // We need to lock the object in order to read it. This
2239 // means that we have to run in a singleton Task. If we
2240 // want to run this in a general Task for better
2241 // performance, we will need one Task for object, plus
2242 // appropriate locking to ensure that we don't conflict with
2243 // other uses of the object.
2244 Task_lock_obj
<Object
> tl(task
, locs
->object
);
2245 std::string lineno
= Dwarf_line_info::one_addr2line(
2246 locs
->object
, locs
->shndx
, locs
->offset
);
2247 if (!lineno
.empty())
2248 line_nums
.insert(lineno
);
2251 if (line_nums
.size() > 1)
2253 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2254 "places (possible ODR violation):"),
2255 output_file_name
, demangle(symbol_name
).c_str());
2256 for (std::set
<std::string
>::const_iterator it2
= line_nums
.begin();
2257 it2
!= line_nums
.end();
2259 fprintf(stderr
, " %s\n", it2
->c_str());
2264 // Warnings functions.
2266 // Add a new warning.
2269 Warnings::add_warning(Symbol_table
* symtab
, const char* name
, Object
* obj
,
2270 const std::string
& warning
)
2272 name
= symtab
->canonicalize_name(name
);
2273 this->warnings_
[name
].set(obj
, warning
);
2276 // Look through the warnings and mark the symbols for which we should
2277 // warn. This is called during Layout::finalize when we know the
2278 // sources for all the symbols.
2281 Warnings::note_warnings(Symbol_table
* symtab
)
2283 for (Warning_table::iterator p
= this->warnings_
.begin();
2284 p
!= this->warnings_
.end();
2287 Symbol
* sym
= symtab
->lookup(p
->first
, NULL
);
2289 && sym
->source() == Symbol::FROM_OBJECT
2290 && sym
->object() == p
->second
.object
)
2291 sym
->set_has_warning();
2295 // Issue a warning. This is called when we see a relocation against a
2296 // symbol for which has a warning.
2298 template<int size
, bool big_endian
>
2300 Warnings::issue_warning(const Symbol
* sym
,
2301 const Relocate_info
<size
, big_endian
>* relinfo
,
2302 size_t relnum
, off_t reloffset
) const
2304 gold_assert(sym
->has_warning());
2305 Warning_table::const_iterator p
= this->warnings_
.find(sym
->name());
2306 gold_assert(p
!= this->warnings_
.end());
2307 gold_warning_at_location(relinfo
, relnum
, reloffset
,
2308 "%s", p
->second
.text
.c_str());
2311 // Instantiate the templates we need. We could use the configure
2312 // script to restrict this to only the ones needed for implemented
2315 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2318 Sized_symbol
<32>::allocate_common(Output_data
*, Value_type
);
2321 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2324 Sized_symbol
<64>::allocate_common(Output_data
*, Value_type
);
2327 #ifdef HAVE_TARGET_32_LITTLE
2330 Symbol_table::add_from_relobj
<32, false>(
2331 Sized_relobj
<32, false>* relobj
,
2332 const unsigned char* syms
,
2334 const char* sym_names
,
2335 size_t sym_name_size
,
2336 Sized_relobj
<32, true>::Symbols
* sympointers
);
2339 #ifdef HAVE_TARGET_32_BIG
2342 Symbol_table::add_from_relobj
<32, true>(
2343 Sized_relobj
<32, true>* relobj
,
2344 const unsigned char* syms
,
2346 const char* sym_names
,
2347 size_t sym_name_size
,
2348 Sized_relobj
<32, false>::Symbols
* sympointers
);
2351 #ifdef HAVE_TARGET_64_LITTLE
2354 Symbol_table::add_from_relobj
<64, false>(
2355 Sized_relobj
<64, false>* relobj
,
2356 const unsigned char* syms
,
2358 const char* sym_names
,
2359 size_t sym_name_size
,
2360 Sized_relobj
<64, true>::Symbols
* sympointers
);
2363 #ifdef HAVE_TARGET_64_BIG
2366 Symbol_table::add_from_relobj
<64, true>(
2367 Sized_relobj
<64, true>* relobj
,
2368 const unsigned char* syms
,
2370 const char* sym_names
,
2371 size_t sym_name_size
,
2372 Sized_relobj
<64, false>::Symbols
* sympointers
);
2375 #ifdef HAVE_TARGET_32_LITTLE
2378 Symbol_table::add_from_dynobj
<32, false>(
2379 Sized_dynobj
<32, false>* dynobj
,
2380 const unsigned char* syms
,
2382 const char* sym_names
,
2383 size_t sym_name_size
,
2384 const unsigned char* versym
,
2386 const std::vector
<const char*>* version_map
);
2389 #ifdef HAVE_TARGET_32_BIG
2392 Symbol_table::add_from_dynobj
<32, true>(
2393 Sized_dynobj
<32, true>* dynobj
,
2394 const unsigned char* syms
,
2396 const char* sym_names
,
2397 size_t sym_name_size
,
2398 const unsigned char* versym
,
2400 const std::vector
<const char*>* version_map
);
2403 #ifdef HAVE_TARGET_64_LITTLE
2406 Symbol_table::add_from_dynobj
<64, false>(
2407 Sized_dynobj
<64, false>* dynobj
,
2408 const unsigned char* syms
,
2410 const char* sym_names
,
2411 size_t sym_name_size
,
2412 const unsigned char* versym
,
2414 const std::vector
<const char*>* version_map
);
2417 #ifdef HAVE_TARGET_64_BIG
2420 Symbol_table::add_from_dynobj
<64, true>(
2421 Sized_dynobj
<64, true>* dynobj
,
2422 const unsigned char* syms
,
2424 const char* sym_names
,
2425 size_t sym_name_size
,
2426 const unsigned char* versym
,
2428 const std::vector
<const char*>* version_map
);
2431 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2434 Symbol_table::define_with_copy_reloc
<32>(
2435 Sized_symbol
<32>* sym
,
2437 elfcpp::Elf_types
<32>::Elf_Addr value
);
2440 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2443 Symbol_table::define_with_copy_reloc
<64>(
2444 Sized_symbol
<64>* sym
,
2446 elfcpp::Elf_types
<64>::Elf_Addr value
);
2449 #ifdef HAVE_TARGET_32_LITTLE
2452 Warnings::issue_warning
<32, false>(const Symbol
* sym
,
2453 const Relocate_info
<32, false>* relinfo
,
2454 size_t relnum
, off_t reloffset
) const;
2457 #ifdef HAVE_TARGET_32_BIG
2460 Warnings::issue_warning
<32, true>(const Symbol
* sym
,
2461 const Relocate_info
<32, true>* relinfo
,
2462 size_t relnum
, off_t reloffset
) const;
2465 #ifdef HAVE_TARGET_64_LITTLE
2468 Warnings::issue_warning
<64, false>(const Symbol
* sym
,
2469 const Relocate_info
<64, false>* relinfo
,
2470 size_t relnum
, off_t reloffset
) const;
2473 #ifdef HAVE_TARGET_64_BIG
2476 Warnings::issue_warning
<64, true>(const Symbol
* sym
,
2477 const Relocate_info
<64, true>* relinfo
,
2478 size_t relnum
, off_t reloffset
) const;
2481 } // End namespace gold.