1 // resolve.cc -- symbol resolution for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 // Symbol methods used in this file.
36 // This symbol is being overridden by another symbol whose version is
37 // VERSION. Update the VERSION_ field accordingly.
40 Symbol::override_version(const char* version
)
44 // This is the case where this symbol is NAME/VERSION, and the
45 // version was not marked as hidden. That makes it the default
46 // version, so we create NAME/NULL. Later we see another symbol
47 // NAME/NULL, and that symbol is overriding this one. In this
48 // case, since NAME/VERSION is the default, we make NAME/NULL
49 // override NAME/VERSION as well. They are already the same
50 // Symbol structure. Setting the VERSION_ field to NULL ensures
51 // that it will be output with the correct, empty, version.
52 this->version_
= version
;
56 // This is the case where this symbol is NAME/VERSION_ONE, and
57 // now we see NAME/VERSION_TWO, and NAME/VERSION_TWO is
58 // overriding NAME. If VERSION_ONE and VERSION_TWO are
59 // different, then this can only happen when VERSION_ONE is NULL
60 // and VERSION_TWO is not hidden.
61 gold_assert(this->version_
== version
|| this->version_
== NULL
);
62 this->version_
= version
;
66 // This symbol is being overidden by another symbol whose visibility
67 // is VISIBILITY. Updated the VISIBILITY_ field accordingly.
70 Symbol::override_visibility(elfcpp::STV visibility
)
72 // The rule for combining visibility is that we always choose the
73 // most constrained visibility. In order of increasing constraint,
74 // visibility goes PROTECTED, HIDDEN, INTERNAL. This is the reverse
75 // of the numeric values, so the effect is that we always want the
76 // smallest non-zero value.
77 if (visibility
!= elfcpp::STV_DEFAULT
)
79 if (this->visibility_
== elfcpp::STV_DEFAULT
)
80 this->visibility_
= visibility
;
81 else if (this->visibility_
> visibility
)
82 this->visibility_
= visibility
;
86 // Override the fields in Symbol.
88 template<int size
, bool big_endian
>
90 Symbol::override_base(const elfcpp::Sym
<size
, big_endian
>& sym
,
91 unsigned int st_shndx
, bool is_ordinary
,
92 Object
* object
, const char* version
)
94 gold_assert(this->source_
== FROM_OBJECT
);
95 this->u_
.from_object
.object
= object
;
96 this->override_version(version
);
97 this->u_
.from_object
.shndx
= st_shndx
;
98 this->is_ordinary_shndx_
= is_ordinary
;
99 this->type_
= sym
.get_st_type();
100 this->binding_
= sym
.get_st_bind();
101 this->override_visibility(sym
.get_st_visibility());
102 this->nonvis_
= sym
.get_st_nonvis();
103 if (object
->is_dynamic())
104 this->in_dyn_
= true;
106 this->in_reg_
= true;
109 // Override the fields in Sized_symbol.
112 template<bool big_endian
>
114 Sized_symbol
<size
>::override(const elfcpp::Sym
<size
, big_endian
>& sym
,
115 unsigned st_shndx
, bool is_ordinary
,
116 Object
* object
, const char* version
)
118 this->override_base(sym
, st_shndx
, is_ordinary
, object
, version
);
119 this->value_
= sym
.get_st_value();
120 this->symsize_
= sym
.get_st_size();
123 // Override TOSYM with symbol FROMSYM, defined in OBJECT, with version
124 // VERSION. This handles all aliases of TOSYM.
126 template<int size
, bool big_endian
>
128 Symbol_table::override(Sized_symbol
<size
>* tosym
,
129 const elfcpp::Sym
<size
, big_endian
>& fromsym
,
130 unsigned int st_shndx
, bool is_ordinary
,
131 Object
* object
, const char* version
)
133 tosym
->override(fromsym
, st_shndx
, is_ordinary
, object
, version
);
134 if (tosym
->has_alias())
136 Symbol
* sym
= this->weak_aliases_
[tosym
];
137 gold_assert(sym
!= NULL
);
138 Sized_symbol
<size
>* ssym
= this->get_sized_symbol
<size
>(sym
);
141 ssym
->override(fromsym
, st_shndx
, is_ordinary
, object
, version
);
142 sym
= this->weak_aliases_
[ssym
];
143 gold_assert(sym
!= NULL
);
144 ssym
= this->get_sized_symbol
<size
>(sym
);
146 while (ssym
!= tosym
);
150 // The resolve functions build a little code for each symbol.
151 // Bit 0: 0 for global, 1 for weak.
152 // Bit 1: 0 for regular object, 1 for shared object
153 // Bits 2-3: 0 for normal, 1 for undefined, 2 for common
154 // This gives us values from 0 to 11.
156 static const int global_or_weak_shift
= 0;
157 static const unsigned int global_flag
= 0 << global_or_weak_shift
;
158 static const unsigned int weak_flag
= 1 << global_or_weak_shift
;
160 static const int regular_or_dynamic_shift
= 1;
161 static const unsigned int regular_flag
= 0 << regular_or_dynamic_shift
;
162 static const unsigned int dynamic_flag
= 1 << regular_or_dynamic_shift
;
164 static const int def_undef_or_common_shift
= 2;
165 static const unsigned int def_flag
= 0 << def_undef_or_common_shift
;
166 static const unsigned int undef_flag
= 1 << def_undef_or_common_shift
;
167 static const unsigned int common_flag
= 2 << def_undef_or_common_shift
;
169 // This convenience function combines all the flags based on facts
173 symbol_to_bits(elfcpp::STB binding
, bool is_dynamic
,
174 unsigned int shndx
, bool is_ordinary
, elfcpp::STT type
)
180 case elfcpp::STB_GLOBAL
:
181 case elfcpp::STB_GNU_UNIQUE
:
185 case elfcpp::STB_WEAK
:
189 case elfcpp::STB_LOCAL
:
190 // We should only see externally visible symbols in the symbol
192 gold_error(_("invalid STB_LOCAL symbol in external symbols"));
196 // Any target which wants to handle STB_LOOS, etc., needs to
197 // define a resolve method.
198 gold_error(_("unsupported symbol binding %d"), static_cast<int>(binding
));
203 bits
|= dynamic_flag
;
205 bits
|= regular_flag
;
209 case elfcpp::SHN_UNDEF
:
213 case elfcpp::SHN_COMMON
:
219 if (type
== elfcpp::STT_COMMON
)
221 else if (!is_ordinary
&& Symbol::is_common_shndx(shndx
))
231 // Resolve a symbol. This is called the second and subsequent times
232 // we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the
233 // section index for SYM, possibly adjusted for many sections.
234 // IS_ORDINARY is whether ST_SHNDX is a normal section index rather
235 // than a special code. ORIG_ST_SHNDX is the original section index,
236 // before any munging because of discarded sections, except that all
237 // non-ordinary section indexes are mapped to SHN_UNDEF. VERSION is
238 // the version of SYM.
240 template<int size
, bool big_endian
>
242 Symbol_table::resolve(Sized_symbol
<size
>* to
,
243 const elfcpp::Sym
<size
, big_endian
>& sym
,
244 unsigned int st_shndx
, bool is_ordinary
,
245 unsigned int orig_st_shndx
,
246 Object
* object
, const char* version
)
248 // It's possible for a symbol to be defined in an object file
249 // using .symver to give it a version, and for there to also be
250 // a linker script giving that symbol the same version. We
251 // don't want to give a multiple-definition error for this
252 // harmless redefinition.
254 if (to
->source() == Symbol::FROM_OBJECT
255 && to
->object() == object
258 && to
->shndx(&to_is_ordinary
) == st_shndx
260 && to
->value() == sym
.get_st_value())
263 if (parameters
->target().has_resolve())
265 Sized_target
<size
, big_endian
>* sized_target
;
266 sized_target
= parameters
->sized_target
<size
, big_endian
>();
267 sized_target
->resolve(to
, sym
, object
, version
);
271 if (!object
->is_dynamic())
273 // Record that we've seen this symbol in a regular object.
276 else if (st_shndx
== elfcpp::SHN_UNDEF
277 && (to
->visibility() == elfcpp::STV_HIDDEN
278 || to
->visibility() == elfcpp::STV_INTERNAL
))
280 // A dynamic object cannot reference a hidden or internal symbol
281 // defined in another object.
282 gold_warning(_("%s symbol '%s' in %s is referenced by DSO %s"),
283 (to
->visibility() == elfcpp::STV_HIDDEN
286 to
->demangled_name().c_str(),
287 to
->object()->name().c_str(),
288 object
->name().c_str());
293 // Record that we've seen this symbol in a dynamic object.
297 // Record if we've seen this symbol in a real ELF object (i.e., the
298 // symbol is referenced from outside the world known to the plugin).
299 if (object
->pluginobj() == NULL
)
300 to
->set_in_real_elf();
302 // If we're processing replacement files, allow new symbols to override
303 // the placeholders from the plugin objects.
304 if (to
->source() == Symbol::FROM_OBJECT
)
306 Pluginobj
* obj
= to
->object()->pluginobj();
308 && parameters
->options().plugins()->in_replacement_phase())
310 this->override(to
, sym
, st_shndx
, is_ordinary
, object
, version
);
315 // A new weak undefined reference, merging with an old weak
316 // reference, could be a One Definition Rule (ODR) violation --
317 // especially if the types or sizes of the references differ. We'll
318 // store such pairs and look them up later to make sure they
319 // actually refer to the same lines of code. We also check
320 // combinations of weak and strong, which might occur if one case is
321 // inline and the other is not. (Note: not all ODR violations can
322 // be found this way, and not everything this finds is an ODR
323 // violation. But it's helpful to warn about.)
324 if (parameters
->options().detect_odr_violations()
325 && (sym
.get_st_bind() == elfcpp::STB_WEAK
326 || to
->binding() == elfcpp::STB_WEAK
)
327 && orig_st_shndx
!= elfcpp::SHN_UNDEF
328 && to
->shndx(&to_is_ordinary
) != elfcpp::SHN_UNDEF
330 && sym
.get_st_size() != 0 // Ignore weird 0-sized symbols.
331 && to
->symsize() != 0
332 && (sym
.get_st_type() != to
->type()
333 || sym
.get_st_size() != to
->symsize())
334 // C does not have a concept of ODR, so we only need to do this
335 // on C++ symbols. These have (mangled) names starting with _Z.
336 && to
->name()[0] == '_' && to
->name()[1] == 'Z')
338 Symbol_location fromloc
339 = { object
, orig_st_shndx
, sym
.get_st_value() };
340 Symbol_location toloc
= { to
->object(), to
->shndx(&to_is_ordinary
),
342 this->candidate_odr_violations_
[to
->name()].insert(fromloc
);
343 this->candidate_odr_violations_
[to
->name()].insert(toloc
);
346 unsigned int frombits
= symbol_to_bits(sym
.get_st_bind(),
347 object
->is_dynamic(),
348 st_shndx
, is_ordinary
,
351 bool adjust_common_sizes
;
353 typename Sized_symbol
<size
>::Size_type tosize
= to
->symsize();
354 if (Symbol_table::should_override(to
, frombits
, OBJECT
, object
,
355 &adjust_common_sizes
,
358 elfcpp::STB tobinding
= to
->binding();
359 this->override(to
, sym
, st_shndx
, is_ordinary
, object
, version
);
360 if (adjust_common_sizes
&& tosize
> to
->symsize())
361 to
->set_symsize(tosize
);
364 // We are overriding an UNDEF or WEAK UNDEF with a DYN DEF.
365 // Remember which kind of UNDEF it was for future reference.
366 to
->set_undef_binding(tobinding
);
371 if (adjust_common_sizes
&& sym
.get_st_size() > tosize
)
372 to
->set_symsize(sym
.get_st_size());
375 // We are keeping a DYN DEF after seeing an UNDEF or WEAK UNDEF.
376 // Remember which kind of UNDEF it was.
377 to
->set_undef_binding(sym
.get_st_bind());
379 // The ELF ABI says that even for a reference to a symbol we
380 // merge the visibility.
381 to
->override_visibility(sym
.get_st_visibility());
384 if (adjust_common_sizes
&& parameters
->options().warn_common())
386 if (tosize
> sym
.get_st_size())
387 Symbol_table::report_resolve_problem(false,
388 _("common of '%s' overriding "
391 else if (tosize
< sym
.get_st_size())
392 Symbol_table::report_resolve_problem(false,
393 _("common of '%s' overidden by "
397 Symbol_table::report_resolve_problem(false,
398 _("multiple common of '%s'"),
403 // Handle the core of symbol resolution. This is called with the
404 // existing symbol, TO, and a bitflag describing the new symbol. This
405 // returns true if we should override the existing symbol with the new
406 // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to
407 // true if we should set the symbol size to the maximum of the TO and
408 // FROM sizes. It handles error conditions.
411 Symbol_table::should_override(const Symbol
* to
, unsigned int frombits
,
412 Defined defined
, Object
* object
,
413 bool* adjust_common_sizes
,
416 *adjust_common_sizes
= false;
417 *adjust_dyndef
= false;
420 if (to
->source() == Symbol::IS_UNDEFINED
)
421 tobits
= symbol_to_bits(to
->binding(), false, elfcpp::SHN_UNDEF
, true,
423 else if (to
->source() != Symbol::FROM_OBJECT
)
424 tobits
= symbol_to_bits(to
->binding(), false, elfcpp::SHN_ABS
, false,
429 unsigned int shndx
= to
->shndx(&is_ordinary
);
430 tobits
= symbol_to_bits(to
->binding(),
431 to
->object()->is_dynamic(),
437 // FIXME: Warn if either but not both of TO and SYM are STT_TLS.
439 // We use a giant switch table for symbol resolution. This code is
440 // unwieldy, but: 1) it is efficient; 2) we definitely handle all
441 // cases; 3) it is easy to change the handling of a particular case.
442 // The alternative would be a series of conditionals, but it is easy
443 // to get the ordering wrong. This could also be done as a table,
444 // but that is no easier to understand than this large switch
447 // These are the values generated by the bit codes.
450 DEF
= global_flag
| regular_flag
| def_flag
,
451 WEAK_DEF
= weak_flag
| regular_flag
| def_flag
,
452 DYN_DEF
= global_flag
| dynamic_flag
| def_flag
,
453 DYN_WEAK_DEF
= weak_flag
| dynamic_flag
| def_flag
,
454 UNDEF
= global_flag
| regular_flag
| undef_flag
,
455 WEAK_UNDEF
= weak_flag
| regular_flag
| undef_flag
,
456 DYN_UNDEF
= global_flag
| dynamic_flag
| undef_flag
,
457 DYN_WEAK_UNDEF
= weak_flag
| dynamic_flag
| undef_flag
,
458 COMMON
= global_flag
| regular_flag
| common_flag
,
459 WEAK_COMMON
= weak_flag
| regular_flag
| common_flag
,
460 DYN_COMMON
= global_flag
| dynamic_flag
| common_flag
,
461 DYN_WEAK_COMMON
= weak_flag
| dynamic_flag
| common_flag
464 switch (tobits
* 16 + frombits
)
467 // Two definitions of the same symbol.
469 // If either symbol is defined by an object included using
470 // --just-symbols, then don't warn. This is for compatibility
471 // with the GNU linker. FIXME: This is a hack.
472 if ((to
->source() == Symbol::FROM_OBJECT
&& to
->object()->just_symbols())
473 || (object
!= NULL
&& object
->just_symbols()))
476 if (!parameters
->options().muldefs())
477 Symbol_table::report_resolve_problem(true,
478 _("multiple definition of '%s'"),
479 to
, defined
, object
);
482 case WEAK_DEF
* 16 + DEF
:
483 // We've seen a weak definition, and now we see a strong
484 // definition. In the original SVR4 linker, this was treated as
485 // a multiple definition error. In the Solaris linker and the
486 // GNU linker, a weak definition followed by a regular
487 // definition causes the weak definition to be overridden. We
488 // are currently compatible with the GNU linker. In the future
489 // we should add a target specific option to change this.
493 case DYN_DEF
* 16 + DEF
:
494 case DYN_WEAK_DEF
* 16 + DEF
:
495 // We've seen a definition in a dynamic object, and now we see a
496 // definition in a regular object. The definition in the
497 // regular object overrides the definition in the dynamic
501 case UNDEF
* 16 + DEF
:
502 case WEAK_UNDEF
* 16 + DEF
:
503 case DYN_UNDEF
* 16 + DEF
:
504 case DYN_WEAK_UNDEF
* 16 + DEF
:
505 // We've seen an undefined reference, and now we see a
506 // definition. We use the definition.
509 case COMMON
* 16 + DEF
:
510 case WEAK_COMMON
* 16 + DEF
:
511 case DYN_COMMON
* 16 + DEF
:
512 case DYN_WEAK_COMMON
* 16 + DEF
:
513 // We've seen a common symbol and now we see a definition. The
514 // definition overrides.
515 if (parameters
->options().warn_common())
516 Symbol_table::report_resolve_problem(false,
517 _("definition of '%s' overriding "
519 to
, defined
, object
);
522 case DEF
* 16 + WEAK_DEF
:
523 case WEAK_DEF
* 16 + WEAK_DEF
:
524 // We've seen a definition and now we see a weak definition. We
525 // ignore the new weak definition.
528 case DYN_DEF
* 16 + WEAK_DEF
:
529 case DYN_WEAK_DEF
* 16 + WEAK_DEF
:
530 // We've seen a dynamic definition and now we see a regular weak
531 // definition. The regular weak definition overrides.
534 case UNDEF
* 16 + WEAK_DEF
:
535 case WEAK_UNDEF
* 16 + WEAK_DEF
:
536 case DYN_UNDEF
* 16 + WEAK_DEF
:
537 case DYN_WEAK_UNDEF
* 16 + WEAK_DEF
:
538 // A weak definition of a currently undefined symbol.
541 case COMMON
* 16 + WEAK_DEF
:
542 case WEAK_COMMON
* 16 + WEAK_DEF
:
543 // A weak definition does not override a common definition.
546 case DYN_COMMON
* 16 + WEAK_DEF
:
547 case DYN_WEAK_COMMON
* 16 + WEAK_DEF
:
548 // A weak definition does override a definition in a dynamic
550 if (parameters
->options().warn_common())
551 Symbol_table::report_resolve_problem(false,
552 _("definition of '%s' overriding "
553 "dynamic common definition"),
554 to
, defined
, object
);
557 case DEF
* 16 + DYN_DEF
:
558 case WEAK_DEF
* 16 + DYN_DEF
:
559 case DYN_DEF
* 16 + DYN_DEF
:
560 case DYN_WEAK_DEF
* 16 + DYN_DEF
:
561 // Ignore a dynamic definition if we already have a definition.
564 case UNDEF
* 16 + DYN_DEF
:
565 case DYN_UNDEF
* 16 + DYN_DEF
:
566 case DYN_WEAK_UNDEF
* 16 + DYN_DEF
:
567 // Use a dynamic definition if we have a reference.
570 case WEAK_UNDEF
* 16 + DYN_DEF
:
571 // When overriding a weak undef by a dynamic definition,
572 // we need to remember that the original undef was weak.
573 *adjust_dyndef
= true;
576 case COMMON
* 16 + DYN_DEF
:
577 case WEAK_COMMON
* 16 + DYN_DEF
:
578 case DYN_COMMON
* 16 + DYN_DEF
:
579 case DYN_WEAK_COMMON
* 16 + DYN_DEF
:
580 // Ignore a dynamic definition if we already have a common
584 case DEF
* 16 + DYN_WEAK_DEF
:
585 case WEAK_DEF
* 16 + DYN_WEAK_DEF
:
586 case DYN_DEF
* 16 + DYN_WEAK_DEF
:
587 case DYN_WEAK_DEF
* 16 + DYN_WEAK_DEF
:
588 // Ignore a weak dynamic definition if we already have a
592 case UNDEF
* 16 + DYN_WEAK_DEF
:
593 // When overriding an undef by a dynamic weak definition,
594 // we need to remember that the original undef was not weak.
595 *adjust_dyndef
= true;
598 case DYN_UNDEF
* 16 + DYN_WEAK_DEF
:
599 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_DEF
:
600 // Use a weak dynamic definition if we have a reference.
603 case WEAK_UNDEF
* 16 + DYN_WEAK_DEF
:
604 // When overriding a weak undef by a dynamic definition,
605 // we need to remember that the original undef was weak.
606 *adjust_dyndef
= true;
609 case COMMON
* 16 + DYN_WEAK_DEF
:
610 case WEAK_COMMON
* 16 + DYN_WEAK_DEF
:
611 case DYN_COMMON
* 16 + DYN_WEAK_DEF
:
612 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_DEF
:
613 // Ignore a weak dynamic definition if we already have a common
617 case DEF
* 16 + UNDEF
:
618 case WEAK_DEF
* 16 + UNDEF
:
619 case UNDEF
* 16 + UNDEF
:
620 // A new undefined reference tells us nothing.
623 case DYN_DEF
* 16 + UNDEF
:
624 case DYN_WEAK_DEF
* 16 + UNDEF
:
625 // For a dynamic def, we need to remember which kind of undef we see.
626 *adjust_dyndef
= true;
629 case WEAK_UNDEF
* 16 + UNDEF
:
630 case DYN_UNDEF
* 16 + UNDEF
:
631 case DYN_WEAK_UNDEF
* 16 + UNDEF
:
632 // A strong undef overrides a dynamic or weak undef.
635 case COMMON
* 16 + UNDEF
:
636 case WEAK_COMMON
* 16 + UNDEF
:
637 case DYN_COMMON
* 16 + UNDEF
:
638 case DYN_WEAK_COMMON
* 16 + UNDEF
:
639 // A new undefined reference tells us nothing.
642 case DEF
* 16 + WEAK_UNDEF
:
643 case WEAK_DEF
* 16 + WEAK_UNDEF
:
644 case UNDEF
* 16 + WEAK_UNDEF
:
645 case WEAK_UNDEF
* 16 + WEAK_UNDEF
:
646 case DYN_UNDEF
* 16 + WEAK_UNDEF
:
647 case COMMON
* 16 + WEAK_UNDEF
:
648 case WEAK_COMMON
* 16 + WEAK_UNDEF
:
649 case DYN_COMMON
* 16 + WEAK_UNDEF
:
650 case DYN_WEAK_COMMON
* 16 + WEAK_UNDEF
:
651 // A new weak undefined reference tells us nothing unless the
652 // exisiting symbol is a dynamic weak reference.
655 case DYN_WEAK_UNDEF
* 16 + WEAK_UNDEF
:
656 // A new weak reference overrides an existing dynamic weak reference.
657 // This is necessary because a dynamic weak reference remembers
658 // the old binding, which may not be weak. If we keeps the existing
659 // dynamic weak reference, the weakness may be dropped in the output.
662 case DYN_DEF
* 16 + WEAK_UNDEF
:
663 case DYN_WEAK_DEF
* 16 + WEAK_UNDEF
:
664 // For a dynamic def, we need to remember which kind of undef we see.
665 *adjust_dyndef
= true;
668 case DEF
* 16 + DYN_UNDEF
:
669 case WEAK_DEF
* 16 + DYN_UNDEF
:
670 case DYN_DEF
* 16 + DYN_UNDEF
:
671 case DYN_WEAK_DEF
* 16 + DYN_UNDEF
:
672 case UNDEF
* 16 + DYN_UNDEF
:
673 case WEAK_UNDEF
* 16 + DYN_UNDEF
:
674 case DYN_UNDEF
* 16 + DYN_UNDEF
:
675 case DYN_WEAK_UNDEF
* 16 + DYN_UNDEF
:
676 case COMMON
* 16 + DYN_UNDEF
:
677 case WEAK_COMMON
* 16 + DYN_UNDEF
:
678 case DYN_COMMON
* 16 + DYN_UNDEF
:
679 case DYN_WEAK_COMMON
* 16 + DYN_UNDEF
:
680 // A new dynamic undefined reference tells us nothing.
683 case DEF
* 16 + DYN_WEAK_UNDEF
:
684 case WEAK_DEF
* 16 + DYN_WEAK_UNDEF
:
685 case DYN_DEF
* 16 + DYN_WEAK_UNDEF
:
686 case DYN_WEAK_DEF
* 16 + DYN_WEAK_UNDEF
:
687 case UNDEF
* 16 + DYN_WEAK_UNDEF
:
688 case WEAK_UNDEF
* 16 + DYN_WEAK_UNDEF
:
689 case DYN_UNDEF
* 16 + DYN_WEAK_UNDEF
:
690 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_UNDEF
:
691 case COMMON
* 16 + DYN_WEAK_UNDEF
:
692 case WEAK_COMMON
* 16 + DYN_WEAK_UNDEF
:
693 case DYN_COMMON
* 16 + DYN_WEAK_UNDEF
:
694 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_UNDEF
:
695 // A new weak dynamic undefined reference tells us nothing.
698 case DEF
* 16 + COMMON
:
699 // A common symbol does not override a definition.
700 if (parameters
->options().warn_common())
701 Symbol_table::report_resolve_problem(false,
702 _("common '%s' overridden by "
703 "previous definition"),
704 to
, defined
, object
);
707 case WEAK_DEF
* 16 + COMMON
:
708 case DYN_DEF
* 16 + COMMON
:
709 case DYN_WEAK_DEF
* 16 + COMMON
:
710 // A common symbol does override a weak definition or a dynamic
714 case UNDEF
* 16 + COMMON
:
715 case WEAK_UNDEF
* 16 + COMMON
:
716 case DYN_UNDEF
* 16 + COMMON
:
717 case DYN_WEAK_UNDEF
* 16 + COMMON
:
718 // A common symbol is a definition for a reference.
721 case COMMON
* 16 + COMMON
:
722 // Set the size to the maximum.
723 *adjust_common_sizes
= true;
726 case WEAK_COMMON
* 16 + COMMON
:
727 // I'm not sure just what a weak common symbol means, but
728 // presumably it can be overridden by a regular common symbol.
731 case DYN_COMMON
* 16 + COMMON
:
732 case DYN_WEAK_COMMON
* 16 + COMMON
:
733 // Use the real common symbol, but adjust the size if necessary.
734 *adjust_common_sizes
= true;
737 case DEF
* 16 + WEAK_COMMON
:
738 case WEAK_DEF
* 16 + WEAK_COMMON
:
739 case DYN_DEF
* 16 + WEAK_COMMON
:
740 case DYN_WEAK_DEF
* 16 + WEAK_COMMON
:
741 // Whatever a weak common symbol is, it won't override a
745 case UNDEF
* 16 + WEAK_COMMON
:
746 case WEAK_UNDEF
* 16 + WEAK_COMMON
:
747 case DYN_UNDEF
* 16 + WEAK_COMMON
:
748 case DYN_WEAK_UNDEF
* 16 + WEAK_COMMON
:
749 // A weak common symbol is better than an undefined symbol.
752 case COMMON
* 16 + WEAK_COMMON
:
753 case WEAK_COMMON
* 16 + WEAK_COMMON
:
754 case DYN_COMMON
* 16 + WEAK_COMMON
:
755 case DYN_WEAK_COMMON
* 16 + WEAK_COMMON
:
756 // Ignore a weak common symbol in the presence of a real common
760 case DEF
* 16 + DYN_COMMON
:
761 case WEAK_DEF
* 16 + DYN_COMMON
:
762 case DYN_DEF
* 16 + DYN_COMMON
:
763 case DYN_WEAK_DEF
* 16 + DYN_COMMON
:
764 // Ignore a dynamic common symbol in the presence of a
768 case UNDEF
* 16 + DYN_COMMON
:
769 case WEAK_UNDEF
* 16 + DYN_COMMON
:
770 case DYN_UNDEF
* 16 + DYN_COMMON
:
771 case DYN_WEAK_UNDEF
* 16 + DYN_COMMON
:
772 // A dynamic common symbol is a definition of sorts.
775 case COMMON
* 16 + DYN_COMMON
:
776 case WEAK_COMMON
* 16 + DYN_COMMON
:
777 case DYN_COMMON
* 16 + DYN_COMMON
:
778 case DYN_WEAK_COMMON
* 16 + DYN_COMMON
:
779 // Set the size to the maximum.
780 *adjust_common_sizes
= true;
783 case DEF
* 16 + DYN_WEAK_COMMON
:
784 case WEAK_DEF
* 16 + DYN_WEAK_COMMON
:
785 case DYN_DEF
* 16 + DYN_WEAK_COMMON
:
786 case DYN_WEAK_DEF
* 16 + DYN_WEAK_COMMON
:
787 // A common symbol is ignored in the face of a definition.
790 case UNDEF
* 16 + DYN_WEAK_COMMON
:
791 case WEAK_UNDEF
* 16 + DYN_WEAK_COMMON
:
792 case DYN_UNDEF
* 16 + DYN_WEAK_COMMON
:
793 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_COMMON
:
794 // I guess a weak common symbol is better than a definition.
797 case COMMON
* 16 + DYN_WEAK_COMMON
:
798 case WEAK_COMMON
* 16 + DYN_WEAK_COMMON
:
799 case DYN_COMMON
* 16 + DYN_WEAK_COMMON
:
800 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_COMMON
:
801 // Set the size to the maximum.
802 *adjust_common_sizes
= true;
810 // Issue an error or warning due to symbol resolution. IS_ERROR
811 // indicates an error rather than a warning. MSG is the error
812 // message; it is expected to have a %s for the symbol name. TO is
813 // the existing symbol. DEFINED/OBJECT is where the new symbol was
816 // FIXME: We should have better location information here. When the
817 // symbol is defined, we should be able to pull the location from the
818 // debug info if there is any.
821 Symbol_table::report_resolve_problem(bool is_error
, const char* msg
,
822 const Symbol
* to
, Defined defined
,
825 std::string
demangled(to
->demangled_name());
826 size_t len
= strlen(msg
) + demangled
.length() + 10;
827 char* buf
= new char[len
];
828 snprintf(buf
, len
, msg
, demangled
.c_str());
834 objname
= object
->name().c_str();
837 objname
= _("COPY reloc");
841 objname
= _("command line");
844 objname
= _("linker script");
847 case INCREMENTAL_BASE
:
848 objname
= _("linker defined");
855 gold_error("%s: %s", objname
, buf
);
857 gold_warning("%s: %s", objname
, buf
);
861 if (to
->source() == Symbol::FROM_OBJECT
)
862 objname
= to
->object()->name().c_str();
864 objname
= _("command line");
865 gold_info("%s: %s: previous definition here", program_name
, objname
);
868 // A special case of should_override which is only called for a strong
869 // defined symbol from a regular object file. This is used when
870 // defining special symbols.
873 Symbol_table::should_override_with_special(const Symbol
* to
, Defined defined
)
875 bool adjust_common_sizes
;
877 unsigned int frombits
= global_flag
| regular_flag
| def_flag
;
878 bool ret
= Symbol_table::should_override(to
, frombits
, defined
, NULL
,
879 &adjust_common_sizes
,
881 gold_assert(!adjust_common_sizes
&& !adjust_dyn_def
);
885 // Override symbol base with a special symbol.
888 Symbol::override_base_with_special(const Symbol
* from
)
890 bool same_name
= this->name_
== from
->name_
;
891 gold_assert(same_name
|| this->has_alias());
893 this->source_
= from
->source_
;
894 switch (from
->source_
)
897 this->u_
.from_object
= from
->u_
.from_object
;
900 this->u_
.in_output_data
= from
->u_
.in_output_data
;
902 case IN_OUTPUT_SEGMENT
:
903 this->u_
.in_output_segment
= from
->u_
.in_output_segment
;
914 this->override_version(from
->version_
);
915 this->type_
= from
->type_
;
916 this->binding_
= from
->binding_
;
917 this->override_visibility(from
->visibility_
);
918 this->nonvis_
= from
->nonvis_
;
920 // Special symbols are always considered to be regular symbols.
921 this->in_reg_
= true;
923 if (from
->needs_dynsym_entry_
)
924 this->needs_dynsym_entry_
= true;
925 if (from
->needs_dynsym_value_
)
926 this->needs_dynsym_value_
= true;
928 this->is_predefined_
= from
->is_predefined_
;
930 // We shouldn't see these flags. If we do, we need to handle them
932 gold_assert(!from
->is_forwarder_
);
933 gold_assert(!from
->has_plt_offset());
934 gold_assert(!from
->has_warning_
);
935 gold_assert(!from
->is_copied_from_dynobj_
);
936 gold_assert(!from
->is_forced_local_
);
939 // Override a symbol with a special symbol.
943 Sized_symbol
<size
>::override_with_special(const Sized_symbol
<size
>* from
)
945 this->override_base_with_special(from
);
946 this->value_
= from
->value_
;
947 this->symsize_
= from
->symsize_
;
950 // Override TOSYM with the special symbol FROMSYM. This handles all
955 Symbol_table::override_with_special(Sized_symbol
<size
>* tosym
,
956 const Sized_symbol
<size
>* fromsym
)
958 tosym
->override_with_special(fromsym
);
959 if (tosym
->has_alias())
961 Symbol
* sym
= this->weak_aliases_
[tosym
];
962 gold_assert(sym
!= NULL
);
963 Sized_symbol
<size
>* ssym
= this->get_sized_symbol
<size
>(sym
);
966 ssym
->override_with_special(fromsym
);
967 sym
= this->weak_aliases_
[ssym
];
968 gold_assert(sym
!= NULL
);
969 ssym
= this->get_sized_symbol
<size
>(sym
);
971 while (ssym
!= tosym
);
973 if (tosym
->binding() == elfcpp::STB_LOCAL
974 || ((tosym
->visibility() == elfcpp::STV_HIDDEN
975 || tosym
->visibility() == elfcpp::STV_INTERNAL
)
976 && (tosym
->binding() == elfcpp::STB_GLOBAL
977 || tosym
->binding() == elfcpp::STB_GNU_UNIQUE
978 || tosym
->binding() == elfcpp::STB_WEAK
)
979 && !parameters
->options().relocatable()))
980 this->force_local(tosym
);
983 // Instantiate the templates we need. We could use the configure
984 // script to restrict this to only the ones needed for implemented
987 // We have to instantiate both big and little endian versions because
988 // these are used by other templates that depends on size only.
990 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
993 Symbol_table::resolve
<32, false>(
994 Sized_symbol
<32>* to
,
995 const elfcpp::Sym
<32, false>& sym
,
996 unsigned int st_shndx
,
998 unsigned int orig_st_shndx
,
1000 const char* version
);
1004 Symbol_table::resolve
<32, true>(
1005 Sized_symbol
<32>* to
,
1006 const elfcpp::Sym
<32, true>& sym
,
1007 unsigned int st_shndx
,
1009 unsigned int orig_st_shndx
,
1011 const char* version
);
1014 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1017 Symbol_table::resolve
<64, false>(
1018 Sized_symbol
<64>* to
,
1019 const elfcpp::Sym
<64, false>& sym
,
1020 unsigned int st_shndx
,
1022 unsigned int orig_st_shndx
,
1024 const char* version
);
1028 Symbol_table::resolve
<64, true>(
1029 Sized_symbol
<64>* to
,
1030 const elfcpp::Sym
<64, true>& sym
,
1031 unsigned int st_shndx
,
1033 unsigned int orig_st_shndx
,
1035 const char* version
);
1038 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1041 Symbol_table::override_with_special
<32>(Sized_symbol
<32>*,
1042 const Sized_symbol
<32>*);
1045 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1048 Symbol_table::override_with_special
<64>(Sized_symbol
<64>*,
1049 const Sized_symbol
<64>*);
1052 } // End namespace gold.