1 // resolve.cc -- symbol resolution for gold
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
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"));
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 if (parameters
->target().has_resolve())
250 Sized_target
<size
, big_endian
>* sized_target
;
251 sized_target
= parameters
->sized_target
<size
, big_endian
>();
252 sized_target
->resolve(to
, sym
, object
, version
);
256 if (!object
->is_dynamic())
258 // Record that we've seen this symbol in a regular object.
261 else if (st_shndx
== elfcpp::SHN_UNDEF
262 && (to
->visibility() == elfcpp::STV_HIDDEN
263 || to
->visibility() == elfcpp::STV_INTERNAL
))
265 // A dynamic object cannot reference a hidden or internal symbol
266 // defined in another object.
267 gold_warning(_("%s symbol '%s' in %s is referenced by DSO %s"),
268 (to
->visibility() == elfcpp::STV_HIDDEN
271 to
->demangled_name().c_str(),
272 to
->object()->name().c_str(),
273 object
->name().c_str());
278 // Record that we've seen this symbol in a dynamic object.
282 // Record if we've seen this symbol in a real ELF object (i.e., the
283 // symbol is referenced from outside the world known to the plugin).
284 if (object
->pluginobj() == NULL
)
285 to
->set_in_real_elf();
287 // If we're processing replacement files, allow new symbols to override
288 // the placeholders from the plugin objects.
289 if (to
->source() == Symbol::FROM_OBJECT
)
291 Pluginobj
* obj
= to
->object()->pluginobj();
293 && parameters
->options().plugins()->in_replacement_phase())
295 this->override(to
, sym
, st_shndx
, is_ordinary
, object
, version
);
300 unsigned int frombits
= symbol_to_bits(sym
.get_st_bind(),
301 object
->is_dynamic(),
302 st_shndx
, is_ordinary
,
305 bool adjust_common_sizes
;
306 typename Sized_symbol
<size
>::Size_type tosize
= to
->symsize();
307 if (Symbol_table::should_override(to
, frombits
, OBJECT
, object
,
308 &adjust_common_sizes
))
310 this->override(to
, sym
, st_shndx
, is_ordinary
, object
, version
);
311 if (adjust_common_sizes
&& tosize
> to
->symsize())
312 to
->set_symsize(tosize
);
316 if (adjust_common_sizes
&& sym
.get_st_size() > tosize
)
317 to
->set_symsize(sym
.get_st_size());
318 // The ELF ABI says that even for a reference to a symbol we
319 // merge the visibility.
320 to
->override_visibility(sym
.get_st_visibility());
323 if (adjust_common_sizes
&& parameters
->options().warn_common())
325 if (tosize
> sym
.get_st_size())
326 Symbol_table::report_resolve_problem(false,
327 _("common of '%s' overriding "
330 else if (tosize
< sym
.get_st_size())
331 Symbol_table::report_resolve_problem(false,
332 _("common of '%s' overidden by "
336 Symbol_table::report_resolve_problem(false,
337 _("multiple common of '%s'"),
341 // A new weak undefined reference, merging with an old weak
342 // reference, could be a One Definition Rule (ODR) violation --
343 // especially if the types or sizes of the references differ. We'll
344 // store such pairs and look them up later to make sure they
345 // actually refer to the same lines of code. (Note: not all ODR
346 // violations can be found this way, and not everything this finds
347 // is an ODR violation. But it's helpful to warn about.)
349 if (parameters
->options().detect_odr_violations()
350 && sym
.get_st_bind() == elfcpp::STB_WEAK
351 && to
->binding() == elfcpp::STB_WEAK
352 && orig_st_shndx
!= elfcpp::SHN_UNDEF
353 && to
->shndx(&to_is_ordinary
) != elfcpp::SHN_UNDEF
355 && sym
.get_st_size() != 0 // Ignore weird 0-sized symbols.
356 && to
->symsize() != 0
357 && (sym
.get_st_type() != to
->type()
358 || sym
.get_st_size() != to
->symsize())
359 // C does not have a concept of ODR, so we only need to do this
360 // on C++ symbols. These have (mangled) names starting with _Z.
361 && to
->name()[0] == '_' && to
->name()[1] == 'Z')
363 Symbol_location fromloc
364 = { object
, orig_st_shndx
, sym
.get_st_value() };
365 Symbol_location toloc
= { to
->object(), to
->shndx(&to_is_ordinary
),
367 this->candidate_odr_violations_
[to
->name()].insert(fromloc
);
368 this->candidate_odr_violations_
[to
->name()].insert(toloc
);
372 // Handle the core of symbol resolution. This is called with the
373 // existing symbol, TO, and a bitflag describing the new symbol. This
374 // returns true if we should override the existing symbol with the new
375 // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to
376 // true if we should set the symbol size to the maximum of the TO and
377 // FROM sizes. It handles error conditions.
380 Symbol_table::should_override(const Symbol
* to
, unsigned int frombits
,
381 Defined defined
, Object
* object
,
382 bool* adjust_common_sizes
)
384 *adjust_common_sizes
= false;
387 if (to
->source() == Symbol::IS_UNDEFINED
)
388 tobits
= symbol_to_bits(to
->binding(), false, elfcpp::SHN_UNDEF
, true,
390 else if (to
->source() != Symbol::FROM_OBJECT
)
391 tobits
= symbol_to_bits(to
->binding(), false, elfcpp::SHN_ABS
, false,
396 unsigned int shndx
= to
->shndx(&is_ordinary
);
397 tobits
= symbol_to_bits(to
->binding(),
398 to
->object()->is_dynamic(),
404 // FIXME: Warn if either but not both of TO and SYM are STT_TLS.
406 // We use a giant switch table for symbol resolution. This code is
407 // unwieldy, but: 1) it is efficient; 2) we definitely handle all
408 // cases; 3) it is easy to change the handling of a particular case.
409 // The alternative would be a series of conditionals, but it is easy
410 // to get the ordering wrong. This could also be done as a table,
411 // but that is no easier to understand than this large switch
414 // These are the values generated by the bit codes.
417 DEF
= global_flag
| regular_flag
| def_flag
,
418 WEAK_DEF
= weak_flag
| regular_flag
| def_flag
,
419 DYN_DEF
= global_flag
| dynamic_flag
| def_flag
,
420 DYN_WEAK_DEF
= weak_flag
| dynamic_flag
| def_flag
,
421 UNDEF
= global_flag
| regular_flag
| undef_flag
,
422 WEAK_UNDEF
= weak_flag
| regular_flag
| undef_flag
,
423 DYN_UNDEF
= global_flag
| dynamic_flag
| undef_flag
,
424 DYN_WEAK_UNDEF
= weak_flag
| dynamic_flag
| undef_flag
,
425 COMMON
= global_flag
| regular_flag
| common_flag
,
426 WEAK_COMMON
= weak_flag
| regular_flag
| common_flag
,
427 DYN_COMMON
= global_flag
| dynamic_flag
| common_flag
,
428 DYN_WEAK_COMMON
= weak_flag
| dynamic_flag
| common_flag
431 switch (tobits
* 16 + frombits
)
434 // Two definitions of the same symbol.
436 // If either symbol is defined by an object included using
437 // --just-symbols, then don't warn. This is for compatibility
438 // with the GNU linker. FIXME: This is a hack.
439 if ((to
->source() == Symbol::FROM_OBJECT
&& to
->object()->just_symbols())
440 || (object
!= NULL
&& object
->just_symbols()))
443 if (!parameters
->options().allow_multiple_definition()
444 && !parameters
->options().muldefs())
445 Symbol_table::report_resolve_problem(true,
446 _("multiple definition of '%s'"),
447 to
, defined
, object
);
450 case WEAK_DEF
* 16 + DEF
:
451 // We've seen a weak definition, and now we see a strong
452 // definition. In the original SVR4 linker, this was treated as
453 // a multiple definition error. In the Solaris linker and the
454 // GNU linker, a weak definition followed by a regular
455 // definition causes the weak definition to be overridden. We
456 // are currently compatible with the GNU linker. In the future
457 // we should add a target specific option to change this.
461 case DYN_DEF
* 16 + DEF
:
462 case DYN_WEAK_DEF
* 16 + DEF
:
463 // We've seen a definition in a dynamic object, and now we see a
464 // definition in a regular object. The definition in the
465 // regular object overrides the definition in the dynamic
469 case UNDEF
* 16 + DEF
:
470 case WEAK_UNDEF
* 16 + DEF
:
471 case DYN_UNDEF
* 16 + DEF
:
472 case DYN_WEAK_UNDEF
* 16 + DEF
:
473 // We've seen an undefined reference, and now we see a
474 // definition. We use the definition.
477 case COMMON
* 16 + DEF
:
478 case WEAK_COMMON
* 16 + DEF
:
479 case DYN_COMMON
* 16 + DEF
:
480 case DYN_WEAK_COMMON
* 16 + DEF
:
481 // We've seen a common symbol and now we see a definition. The
482 // definition overrides.
483 if (parameters
->options().warn_common())
484 Symbol_table::report_resolve_problem(false,
485 _("definition of '%s' overriding "
487 to
, defined
, object
);
490 case DEF
* 16 + WEAK_DEF
:
491 case WEAK_DEF
* 16 + WEAK_DEF
:
492 // We've seen a definition and now we see a weak definition. We
493 // ignore the new weak definition.
496 case DYN_DEF
* 16 + WEAK_DEF
:
497 case DYN_WEAK_DEF
* 16 + WEAK_DEF
:
498 // We've seen a dynamic definition and now we see a regular weak
499 // definition. The regular weak definition overrides.
502 case UNDEF
* 16 + WEAK_DEF
:
503 case WEAK_UNDEF
* 16 + WEAK_DEF
:
504 case DYN_UNDEF
* 16 + WEAK_DEF
:
505 case DYN_WEAK_UNDEF
* 16 + WEAK_DEF
:
506 // A weak definition of a currently undefined symbol.
509 case COMMON
* 16 + WEAK_DEF
:
510 case WEAK_COMMON
* 16 + WEAK_DEF
:
511 // A weak definition does not override a common definition.
514 case DYN_COMMON
* 16 + WEAK_DEF
:
515 case DYN_WEAK_COMMON
* 16 + WEAK_DEF
:
516 // A weak definition does override a definition in a dynamic
518 if (parameters
->options().warn_common())
519 Symbol_table::report_resolve_problem(false,
520 _("definition of '%s' overriding "
521 "dynamic common definition"),
522 to
, defined
, object
);
525 case DEF
* 16 + DYN_DEF
:
526 case WEAK_DEF
* 16 + DYN_DEF
:
527 case DYN_DEF
* 16 + DYN_DEF
:
528 case DYN_WEAK_DEF
* 16 + DYN_DEF
:
529 // Ignore a dynamic definition if we already have a definition.
532 case UNDEF
* 16 + DYN_DEF
:
533 case WEAK_UNDEF
* 16 + DYN_DEF
:
534 case DYN_UNDEF
* 16 + DYN_DEF
:
535 case DYN_WEAK_UNDEF
* 16 + DYN_DEF
:
536 // Use a dynamic definition if we have a reference.
539 case COMMON
* 16 + DYN_DEF
:
540 case WEAK_COMMON
* 16 + DYN_DEF
:
541 case DYN_COMMON
* 16 + DYN_DEF
:
542 case DYN_WEAK_COMMON
* 16 + DYN_DEF
:
543 // Ignore a dynamic definition if we already have a common
547 case DEF
* 16 + DYN_WEAK_DEF
:
548 case WEAK_DEF
* 16 + DYN_WEAK_DEF
:
549 case DYN_DEF
* 16 + DYN_WEAK_DEF
:
550 case DYN_WEAK_DEF
* 16 + DYN_WEAK_DEF
:
551 // Ignore a weak dynamic definition if we already have a
555 case UNDEF
* 16 + DYN_WEAK_DEF
:
556 case WEAK_UNDEF
* 16 + DYN_WEAK_DEF
:
557 case DYN_UNDEF
* 16 + DYN_WEAK_DEF
:
558 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_DEF
:
559 // Use a weak dynamic definition if we have a reference.
562 case COMMON
* 16 + DYN_WEAK_DEF
:
563 case WEAK_COMMON
* 16 + DYN_WEAK_DEF
:
564 case DYN_COMMON
* 16 + DYN_WEAK_DEF
:
565 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_DEF
:
566 // Ignore a weak dynamic definition if we already have a common
570 case DEF
* 16 + UNDEF
:
571 case WEAK_DEF
* 16 + UNDEF
:
572 case DYN_DEF
* 16 + UNDEF
:
573 case DYN_WEAK_DEF
* 16 + UNDEF
:
574 case UNDEF
* 16 + UNDEF
:
575 // A new undefined reference tells us nothing.
578 case WEAK_UNDEF
* 16 + UNDEF
:
579 case DYN_UNDEF
* 16 + UNDEF
:
580 case DYN_WEAK_UNDEF
* 16 + UNDEF
:
581 // A strong undef overrides a dynamic or weak undef.
584 case COMMON
* 16 + UNDEF
:
585 case WEAK_COMMON
* 16 + UNDEF
:
586 case DYN_COMMON
* 16 + UNDEF
:
587 case DYN_WEAK_COMMON
* 16 + UNDEF
:
588 // A new undefined reference tells us nothing.
591 case DEF
* 16 + WEAK_UNDEF
:
592 case WEAK_DEF
* 16 + WEAK_UNDEF
:
593 case DYN_DEF
* 16 + WEAK_UNDEF
:
594 case DYN_WEAK_DEF
* 16 + WEAK_UNDEF
:
595 case UNDEF
* 16 + WEAK_UNDEF
:
596 case WEAK_UNDEF
* 16 + WEAK_UNDEF
:
597 case DYN_UNDEF
* 16 + WEAK_UNDEF
:
598 case DYN_WEAK_UNDEF
* 16 + WEAK_UNDEF
:
599 case COMMON
* 16 + WEAK_UNDEF
:
600 case WEAK_COMMON
* 16 + WEAK_UNDEF
:
601 case DYN_COMMON
* 16 + WEAK_UNDEF
:
602 case DYN_WEAK_COMMON
* 16 + WEAK_UNDEF
:
603 // A new weak undefined reference tells us nothing.
606 case DEF
* 16 + DYN_UNDEF
:
607 case WEAK_DEF
* 16 + DYN_UNDEF
:
608 case DYN_DEF
* 16 + DYN_UNDEF
:
609 case DYN_WEAK_DEF
* 16 + DYN_UNDEF
:
610 case UNDEF
* 16 + DYN_UNDEF
:
611 case WEAK_UNDEF
* 16 + DYN_UNDEF
:
612 case DYN_UNDEF
* 16 + DYN_UNDEF
:
613 case DYN_WEAK_UNDEF
* 16 + DYN_UNDEF
:
614 case COMMON
* 16 + DYN_UNDEF
:
615 case WEAK_COMMON
* 16 + DYN_UNDEF
:
616 case DYN_COMMON
* 16 + DYN_UNDEF
:
617 case DYN_WEAK_COMMON
* 16 + DYN_UNDEF
:
618 // A new dynamic undefined reference tells us nothing.
621 case DEF
* 16 + DYN_WEAK_UNDEF
:
622 case WEAK_DEF
* 16 + DYN_WEAK_UNDEF
:
623 case DYN_DEF
* 16 + DYN_WEAK_UNDEF
:
624 case DYN_WEAK_DEF
* 16 + DYN_WEAK_UNDEF
:
625 case UNDEF
* 16 + DYN_WEAK_UNDEF
:
626 case WEAK_UNDEF
* 16 + DYN_WEAK_UNDEF
:
627 case DYN_UNDEF
* 16 + DYN_WEAK_UNDEF
:
628 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_UNDEF
:
629 case COMMON
* 16 + DYN_WEAK_UNDEF
:
630 case WEAK_COMMON
* 16 + DYN_WEAK_UNDEF
:
631 case DYN_COMMON
* 16 + DYN_WEAK_UNDEF
:
632 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_UNDEF
:
633 // A new weak dynamic undefined reference tells us nothing.
636 case DEF
* 16 + COMMON
:
637 // A common symbol does not override a definition.
638 if (parameters
->options().warn_common())
639 Symbol_table::report_resolve_problem(false,
640 _("common '%s' overridden by "
641 "previous definition"),
642 to
, defined
, object
);
645 case WEAK_DEF
* 16 + COMMON
:
646 case DYN_DEF
* 16 + COMMON
:
647 case DYN_WEAK_DEF
* 16 + COMMON
:
648 // A common symbol does override a weak definition or a dynamic
652 case UNDEF
* 16 + COMMON
:
653 case WEAK_UNDEF
* 16 + COMMON
:
654 case DYN_UNDEF
* 16 + COMMON
:
655 case DYN_WEAK_UNDEF
* 16 + COMMON
:
656 // A common symbol is a definition for a reference.
659 case COMMON
* 16 + COMMON
:
660 // Set the size to the maximum.
661 *adjust_common_sizes
= true;
664 case WEAK_COMMON
* 16 + COMMON
:
665 // I'm not sure just what a weak common symbol means, but
666 // presumably it can be overridden by a regular common symbol.
669 case DYN_COMMON
* 16 + COMMON
:
670 case DYN_WEAK_COMMON
* 16 + COMMON
:
671 // Use the real common symbol, but adjust the size if necessary.
672 *adjust_common_sizes
= true;
675 case DEF
* 16 + WEAK_COMMON
:
676 case WEAK_DEF
* 16 + WEAK_COMMON
:
677 case DYN_DEF
* 16 + WEAK_COMMON
:
678 case DYN_WEAK_DEF
* 16 + WEAK_COMMON
:
679 // Whatever a weak common symbol is, it won't override a
683 case UNDEF
* 16 + WEAK_COMMON
:
684 case WEAK_UNDEF
* 16 + WEAK_COMMON
:
685 case DYN_UNDEF
* 16 + WEAK_COMMON
:
686 case DYN_WEAK_UNDEF
* 16 + WEAK_COMMON
:
687 // A weak common symbol is better than an undefined symbol.
690 case COMMON
* 16 + WEAK_COMMON
:
691 case WEAK_COMMON
* 16 + WEAK_COMMON
:
692 case DYN_COMMON
* 16 + WEAK_COMMON
:
693 case DYN_WEAK_COMMON
* 16 + WEAK_COMMON
:
694 // Ignore a weak common symbol in the presence of a real common
698 case DEF
* 16 + DYN_COMMON
:
699 case WEAK_DEF
* 16 + DYN_COMMON
:
700 case DYN_DEF
* 16 + DYN_COMMON
:
701 case DYN_WEAK_DEF
* 16 + DYN_COMMON
:
702 // Ignore a dynamic common symbol in the presence of a
706 case UNDEF
* 16 + DYN_COMMON
:
707 case WEAK_UNDEF
* 16 + DYN_COMMON
:
708 case DYN_UNDEF
* 16 + DYN_COMMON
:
709 case DYN_WEAK_UNDEF
* 16 + DYN_COMMON
:
710 // A dynamic common symbol is a definition of sorts.
713 case COMMON
* 16 + DYN_COMMON
:
714 case WEAK_COMMON
* 16 + DYN_COMMON
:
715 case DYN_COMMON
* 16 + DYN_COMMON
:
716 case DYN_WEAK_COMMON
* 16 + DYN_COMMON
:
717 // Set the size to the maximum.
718 *adjust_common_sizes
= true;
721 case DEF
* 16 + DYN_WEAK_COMMON
:
722 case WEAK_DEF
* 16 + DYN_WEAK_COMMON
:
723 case DYN_DEF
* 16 + DYN_WEAK_COMMON
:
724 case DYN_WEAK_DEF
* 16 + DYN_WEAK_COMMON
:
725 // A common symbol is ignored in the face of a definition.
728 case UNDEF
* 16 + DYN_WEAK_COMMON
:
729 case WEAK_UNDEF
* 16 + DYN_WEAK_COMMON
:
730 case DYN_UNDEF
* 16 + DYN_WEAK_COMMON
:
731 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_COMMON
:
732 // I guess a weak common symbol is better than a definition.
735 case COMMON
* 16 + DYN_WEAK_COMMON
:
736 case WEAK_COMMON
* 16 + DYN_WEAK_COMMON
:
737 case DYN_COMMON
* 16 + DYN_WEAK_COMMON
:
738 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_COMMON
:
739 // Set the size to the maximum.
740 *adjust_common_sizes
= true;
748 // Issue an error or warning due to symbol resolution. IS_ERROR
749 // indicates an error rather than a warning. MSG is the error
750 // message; it is expected to have a %s for the symbol name. TO is
751 // the existing symbol. DEFINED/OBJECT is where the new symbol was
754 // FIXME: We should have better location information here. When the
755 // symbol is defined, we should be able to pull the location from the
756 // debug info if there is any.
759 Symbol_table::report_resolve_problem(bool is_error
, const char* msg
,
760 const Symbol
* to
, Defined defined
,
763 std::string
demangled(to
->demangled_name());
764 size_t len
= strlen(msg
) + demangled
.length() + 10;
765 char* buf
= new char[len
];
766 snprintf(buf
, len
, msg
, demangled
.c_str());
772 objname
= object
->name().c_str();
775 objname
= _("COPY reloc");
779 objname
= _("command line");
782 objname
= _("linker script");
785 objname
= _("linker defined");
792 gold_error("%s: %s", objname
, buf
);
794 gold_warning("%s: %s", objname
, buf
);
798 if (to
->source() == Symbol::FROM_OBJECT
)
799 objname
= to
->object()->name().c_str();
801 objname
= _("command line");
802 gold_info("%s: %s: previous definition here", program_name
, objname
);
805 // A special case of should_override which is only called for a strong
806 // defined symbol from a regular object file. This is used when
807 // defining special symbols.
810 Symbol_table::should_override_with_special(const Symbol
* to
, Defined defined
)
812 bool adjust_common_sizes
;
813 unsigned int frombits
= global_flag
| regular_flag
| def_flag
;
814 bool ret
= Symbol_table::should_override(to
, frombits
, defined
, NULL
,
815 &adjust_common_sizes
);
816 gold_assert(!adjust_common_sizes
);
820 // Override symbol base with a special symbol.
823 Symbol::override_base_with_special(const Symbol
* from
)
825 gold_assert(this->name_
== from
->name_
|| this->has_alias());
827 this->source_
= from
->source_
;
828 switch (from
->source_
)
831 this->u_
.from_object
= from
->u_
.from_object
;
834 this->u_
.in_output_data
= from
->u_
.in_output_data
;
836 case IN_OUTPUT_SEGMENT
:
837 this->u_
.in_output_segment
= from
->u_
.in_output_segment
;
847 this->override_version(from
->version_
);
848 this->type_
= from
->type_
;
849 this->binding_
= from
->binding_
;
850 this->override_visibility(from
->visibility_
);
851 this->nonvis_
= from
->nonvis_
;
853 // Special symbols are always considered to be regular symbols.
854 this->in_reg_
= true;
856 if (from
->needs_dynsym_entry_
)
857 this->needs_dynsym_entry_
= true;
858 if (from
->needs_dynsym_value_
)
859 this->needs_dynsym_value_
= true;
861 // We shouldn't see these flags. If we do, we need to handle them
863 gold_assert(!from
->is_target_special_
|| this->is_target_special_
);
864 gold_assert(!from
->is_forwarder_
);
865 gold_assert(!from
->has_plt_offset_
);
866 gold_assert(!from
->has_warning_
);
867 gold_assert(!from
->is_copied_from_dynobj_
);
868 gold_assert(!from
->is_forced_local_
);
871 // Override a symbol with a special symbol.
875 Sized_symbol
<size
>::override_with_special(const Sized_symbol
<size
>* from
)
877 this->override_base_with_special(from
);
878 this->value_
= from
->value_
;
879 this->symsize_
= from
->symsize_
;
882 // Override TOSYM with the special symbol FROMSYM. This handles all
887 Symbol_table::override_with_special(Sized_symbol
<size
>* tosym
,
888 const Sized_symbol
<size
>* fromsym
)
890 tosym
->override_with_special(fromsym
);
891 if (tosym
->has_alias())
893 Symbol
* sym
= this->weak_aliases_
[tosym
];
894 gold_assert(sym
!= NULL
);
895 Sized_symbol
<size
>* ssym
= this->get_sized_symbol
<size
>(sym
);
898 ssym
->override_with_special(fromsym
);
899 sym
= this->weak_aliases_
[ssym
];
900 gold_assert(sym
!= NULL
);
901 ssym
= this->get_sized_symbol
<size
>(sym
);
903 while (ssym
!= tosym
);
905 if (tosym
->binding() == elfcpp::STB_LOCAL
906 || ((tosym
->visibility() == elfcpp::STV_HIDDEN
907 || tosym
->visibility() == elfcpp::STV_INTERNAL
)
908 && (tosym
->binding() == elfcpp::STB_GLOBAL
909 || tosym
->binding() == elfcpp::STB_GNU_UNIQUE
910 || tosym
->binding() == elfcpp::STB_WEAK
)
911 && !parameters
->options().relocatable()))
912 this->force_local(tosym
);
915 // Instantiate the templates we need. We could use the configure
916 // script to restrict this to only the ones needed for implemented
919 #ifdef HAVE_TARGET_32_LITTLE
922 Symbol_table::resolve
<32, false>(
923 Sized_symbol
<32>* to
,
924 const elfcpp::Sym
<32, false>& sym
,
925 unsigned int st_shndx
,
927 unsigned int orig_st_shndx
,
929 const char* version
);
932 #ifdef HAVE_TARGET_32_BIG
935 Symbol_table::resolve
<32, true>(
936 Sized_symbol
<32>* to
,
937 const elfcpp::Sym
<32, true>& sym
,
938 unsigned int st_shndx
,
940 unsigned int orig_st_shndx
,
942 const char* version
);
945 #ifdef HAVE_TARGET_64_LITTLE
948 Symbol_table::resolve
<64, false>(
949 Sized_symbol
<64>* to
,
950 const elfcpp::Sym
<64, false>& sym
,
951 unsigned int st_shndx
,
953 unsigned int orig_st_shndx
,
955 const char* version
);
958 #ifdef HAVE_TARGET_64_BIG
961 Symbol_table::resolve
<64, true>(
962 Sized_symbol
<64>* to
,
963 const elfcpp::Sym
<64, true>& sym
,
964 unsigned int st_shndx
,
966 unsigned int orig_st_shndx
,
968 const char* version
);
971 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
974 Symbol_table::override_with_special
<32>(Sized_symbol
<32>*,
975 const Sized_symbol
<32>*);
978 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
981 Symbol_table::override_with_special
<64>(Sized_symbol
<64>*,
982 const Sized_symbol
<64>*);
985 } // End namespace gold.