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
:
184 case elfcpp::STB_WEAK
:
188 case elfcpp::STB_LOCAL
:
189 // We should only see externally visible symbols in the symbol
191 gold_error(_("invalid STB_LOCAL symbol in external symbols"));
195 // Any target which wants to handle STB_LOOS, etc., needs to
196 // define a resolve method.
197 gold_error(_("unsupported symbol binding"));
202 bits
|= dynamic_flag
;
204 bits
|= regular_flag
;
208 case elfcpp::SHN_UNDEF
:
212 case elfcpp::SHN_COMMON
:
218 if (type
== elfcpp::STT_COMMON
)
220 else if (!is_ordinary
&& Symbol::is_common_shndx(shndx
))
230 // Resolve a symbol. This is called the second and subsequent times
231 // we see a symbol. TO is the pre-existing symbol. ST_SHNDX is the
232 // section index for SYM, possibly adjusted for many sections.
233 // IS_ORDINARY is whether ST_SHNDX is a normal section index rather
234 // than a special code. ORIG_ST_SHNDX is the original section index,
235 // before any munging because of discarded sections, except that all
236 // non-ordinary section indexes are mapped to SHN_UNDEF. VERSION is
237 // the version of SYM.
239 template<int size
, bool big_endian
>
241 Symbol_table::resolve(Sized_symbol
<size
>* to
,
242 const elfcpp::Sym
<size
, big_endian
>& sym
,
243 unsigned int st_shndx
, bool is_ordinary
,
244 unsigned int orig_st_shndx
,
245 Object
* object
, const char* version
)
247 if (object
->target()->has_resolve())
249 Sized_target
<size
, big_endian
>* sized_target
;
250 sized_target
= object
->sized_target
<size
, big_endian
>();
251 sized_target
->resolve(to
, sym
, object
, version
);
255 if (!object
->is_dynamic())
257 // Record that we've seen this symbol in a regular object.
260 else if (to
->visibility() == elfcpp::STV_HIDDEN
261 || to
->visibility() == elfcpp::STV_INTERNAL
)
263 // A dynamic object cannot reference a hidden or internal symbol
264 // defined in another object.
265 gold_warning(_("%s symbol '%s' in %s is referenced by DSO %s"),
266 (to
->visibility() == elfcpp::STV_HIDDEN
269 to
->demangled_name().c_str(),
270 to
->object()->name().c_str(),
271 object
->name().c_str());
276 // Record that we've seen this symbol in a dynamic object.
280 // Record if we've seen this symbol in a real ELF object (i.e., the
281 // symbol is referenced from outside the world known to the plugin).
282 if (object
->pluginobj() == NULL
)
283 to
->set_in_real_elf();
285 // If we're processing replacement files, allow new symbols to override
286 // the placeholders from the plugin objects.
287 if (to
->source() == Symbol::FROM_OBJECT
)
289 Pluginobj
* obj
= to
->object()->pluginobj();
291 && parameters
->options().plugins()->in_replacement_phase())
293 this->override(to
, sym
, st_shndx
, is_ordinary
, object
, version
);
298 unsigned int frombits
= symbol_to_bits(sym
.get_st_bind(),
299 object
->is_dynamic(),
300 st_shndx
, is_ordinary
,
303 bool adjust_common_sizes
;
304 if (Symbol_table::should_override(to
, frombits
, object
,
305 &adjust_common_sizes
))
307 typename Sized_symbol
<size
>::Size_type tosize
= to
->symsize();
309 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() > to
->symsize())
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 // A new weak undefined reference, merging with an old weak
324 // reference, could be a One Definition Rule (ODR) violation --
325 // especially if the types or sizes of the references differ. We'll
326 // store such pairs and look them up later to make sure they
327 // actually refer to the same lines of code. (Note: not all ODR
328 // violations can be found this way, and not everything this finds
329 // is an ODR violation. But it's helpful to warn about.)
331 if (parameters
->options().detect_odr_violations()
332 && sym
.get_st_bind() == elfcpp::STB_WEAK
333 && to
->binding() == elfcpp::STB_WEAK
334 && orig_st_shndx
!= elfcpp::SHN_UNDEF
335 && to
->shndx(&to_is_ordinary
) != elfcpp::SHN_UNDEF
337 && sym
.get_st_size() != 0 // Ignore weird 0-sized symbols.
338 && to
->symsize() != 0
339 && (sym
.get_st_type() != to
->type()
340 || sym
.get_st_size() != to
->symsize())
341 // C does not have a concept of ODR, so we only need to do this
342 // on C++ symbols. These have (mangled) names starting with _Z.
343 && to
->name()[0] == '_' && to
->name()[1] == 'Z')
345 Symbol_location fromloc
346 = { object
, orig_st_shndx
, sym
.get_st_value() };
347 Symbol_location toloc
= { to
->object(), to
->shndx(&to_is_ordinary
),
349 this->candidate_odr_violations_
[to
->name()].insert(fromloc
);
350 this->candidate_odr_violations_
[to
->name()].insert(toloc
);
354 // Handle the core of symbol resolution. This is called with the
355 // existing symbol, TO, and a bitflag describing the new symbol. This
356 // returns true if we should override the existing symbol with the new
357 // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to
358 // true if we should set the symbol size to the maximum of the TO and
359 // FROM sizes. It handles error conditions.
362 Symbol_table::should_override(const Symbol
* to
, unsigned int frombits
,
363 Object
* object
, bool* adjust_common_sizes
)
365 *adjust_common_sizes
= false;
368 if (to
->source() == Symbol::IS_UNDEFINED
)
369 tobits
= symbol_to_bits(to
->binding(), false, elfcpp::SHN_UNDEF
, true,
371 else if (to
->source() != Symbol::FROM_OBJECT
)
372 tobits
= symbol_to_bits(to
->binding(), false, elfcpp::SHN_ABS
, false,
377 unsigned int shndx
= to
->shndx(&is_ordinary
);
378 tobits
= symbol_to_bits(to
->binding(),
379 to
->object()->is_dynamic(),
385 // FIXME: Warn if either but not both of TO and SYM are STT_TLS.
387 // We use a giant switch table for symbol resolution. This code is
388 // unwieldy, but: 1) it is efficient; 2) we definitely handle all
389 // cases; 3) it is easy to change the handling of a particular case.
390 // The alternative would be a series of conditionals, but it is easy
391 // to get the ordering wrong. This could also be done as a table,
392 // but that is no easier to understand than this large switch
395 // These are the values generated by the bit codes.
398 DEF
= global_flag
| regular_flag
| def_flag
,
399 WEAK_DEF
= weak_flag
| regular_flag
| def_flag
,
400 DYN_DEF
= global_flag
| dynamic_flag
| def_flag
,
401 DYN_WEAK_DEF
= weak_flag
| dynamic_flag
| def_flag
,
402 UNDEF
= global_flag
| regular_flag
| undef_flag
,
403 WEAK_UNDEF
= weak_flag
| regular_flag
| undef_flag
,
404 DYN_UNDEF
= global_flag
| dynamic_flag
| undef_flag
,
405 DYN_WEAK_UNDEF
= weak_flag
| dynamic_flag
| undef_flag
,
406 COMMON
= global_flag
| regular_flag
| common_flag
,
407 WEAK_COMMON
= weak_flag
| regular_flag
| common_flag
,
408 DYN_COMMON
= global_flag
| dynamic_flag
| common_flag
,
409 DYN_WEAK_COMMON
= weak_flag
| dynamic_flag
| common_flag
412 switch (tobits
* 16 + frombits
)
415 // Two definitions of the same symbol.
417 // If either symbol is defined by an object included using
418 // --just-symbols, then don't warn. This is for compatibility
419 // with the GNU linker. FIXME: This is a hack.
420 if ((to
->source() == Symbol::FROM_OBJECT
&& to
->object()->just_symbols())
421 || object
->just_symbols())
424 // FIXME: Do a better job of reporting locations.
425 gold_error(_("%s: multiple definition of %s"),
426 object
!= NULL
? object
->name().c_str() : _("command line"),
427 to
->demangled_name().c_str());
428 gold_error(_("%s: previous definition here"),
429 (to
->source() == Symbol::FROM_OBJECT
430 ? to
->object()->name().c_str()
431 : _("command line")));
434 case WEAK_DEF
* 16 + DEF
:
435 // We've seen a weak definition, and now we see a strong
436 // definition. In the original SVR4 linker, this was treated as
437 // a multiple definition error. In the Solaris linker and the
438 // GNU linker, a weak definition followed by a regular
439 // definition causes the weak definition to be overridden. We
440 // are currently compatible with the GNU linker. In the future
441 // we should add a target specific option to change this.
445 case DYN_DEF
* 16 + DEF
:
446 case DYN_WEAK_DEF
* 16 + DEF
:
447 // We've seen a definition in a dynamic object, and now we see a
448 // definition in a regular object. The definition in the
449 // regular object overrides the definition in the dynamic
453 case UNDEF
* 16 + DEF
:
454 case WEAK_UNDEF
* 16 + DEF
:
455 case DYN_UNDEF
* 16 + DEF
:
456 case DYN_WEAK_UNDEF
* 16 + DEF
:
457 // We've seen an undefined reference, and now we see a
458 // definition. We use the definition.
461 case COMMON
* 16 + DEF
:
462 case WEAK_COMMON
* 16 + DEF
:
463 case DYN_COMMON
* 16 + DEF
:
464 case DYN_WEAK_COMMON
* 16 + DEF
:
465 // We've seen a common symbol and now we see a definition. The
466 // definition overrides. FIXME: We should optionally issue, version a
470 case DEF
* 16 + WEAK_DEF
:
471 case WEAK_DEF
* 16 + WEAK_DEF
:
472 // We've seen a definition and now we see a weak definition. We
473 // ignore the new weak definition.
476 case DYN_DEF
* 16 + WEAK_DEF
:
477 case DYN_WEAK_DEF
* 16 + WEAK_DEF
:
478 // We've seen a dynamic definition and now we see a regular weak
479 // definition. The regular weak definition overrides.
482 case UNDEF
* 16 + WEAK_DEF
:
483 case WEAK_UNDEF
* 16 + WEAK_DEF
:
484 case DYN_UNDEF
* 16 + WEAK_DEF
:
485 case DYN_WEAK_UNDEF
* 16 + WEAK_DEF
:
486 // A weak definition of a currently undefined symbol.
489 case COMMON
* 16 + WEAK_DEF
:
490 case WEAK_COMMON
* 16 + WEAK_DEF
:
491 // A weak definition does not override a common definition.
494 case DYN_COMMON
* 16 + WEAK_DEF
:
495 case DYN_WEAK_COMMON
* 16 + WEAK_DEF
:
496 // A weak definition does override a definition in a dynamic
497 // object. FIXME: We should optionally issue a warning.
500 case DEF
* 16 + DYN_DEF
:
501 case WEAK_DEF
* 16 + DYN_DEF
:
502 case DYN_DEF
* 16 + DYN_DEF
:
503 case DYN_WEAK_DEF
* 16 + DYN_DEF
:
504 // Ignore a dynamic definition if we already have a definition.
507 case UNDEF
* 16 + DYN_DEF
:
508 case WEAK_UNDEF
* 16 + DYN_DEF
:
509 case DYN_UNDEF
* 16 + DYN_DEF
:
510 case DYN_WEAK_UNDEF
* 16 + DYN_DEF
:
511 // Use a dynamic definition if we have a reference.
514 case COMMON
* 16 + DYN_DEF
:
515 case WEAK_COMMON
* 16 + DYN_DEF
:
516 case DYN_COMMON
* 16 + DYN_DEF
:
517 case DYN_WEAK_COMMON
* 16 + DYN_DEF
:
518 // Ignore a dynamic definition if we already have a common
522 case DEF
* 16 + DYN_WEAK_DEF
:
523 case WEAK_DEF
* 16 + DYN_WEAK_DEF
:
524 case DYN_DEF
* 16 + DYN_WEAK_DEF
:
525 case DYN_WEAK_DEF
* 16 + DYN_WEAK_DEF
:
526 // Ignore a weak dynamic definition if we already have a
530 case UNDEF
* 16 + DYN_WEAK_DEF
:
531 case WEAK_UNDEF
* 16 + DYN_WEAK_DEF
:
532 case DYN_UNDEF
* 16 + DYN_WEAK_DEF
:
533 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_DEF
:
534 // Use a weak dynamic definition if we have a reference.
537 case COMMON
* 16 + DYN_WEAK_DEF
:
538 case WEAK_COMMON
* 16 + DYN_WEAK_DEF
:
539 case DYN_COMMON
* 16 + DYN_WEAK_DEF
:
540 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_DEF
:
541 // Ignore a weak dynamic definition if we already have a common
545 case DEF
* 16 + UNDEF
:
546 case WEAK_DEF
* 16 + UNDEF
:
547 case DYN_DEF
* 16 + UNDEF
:
548 case DYN_WEAK_DEF
* 16 + UNDEF
:
549 case UNDEF
* 16 + UNDEF
:
550 // A new undefined reference tells us nothing.
553 case WEAK_UNDEF
* 16 + UNDEF
:
554 case DYN_UNDEF
* 16 + UNDEF
:
555 case DYN_WEAK_UNDEF
* 16 + UNDEF
:
556 // A strong undef overrides a dynamic or weak undef.
559 case COMMON
* 16 + UNDEF
:
560 case WEAK_COMMON
* 16 + UNDEF
:
561 case DYN_COMMON
* 16 + UNDEF
:
562 case DYN_WEAK_COMMON
* 16 + UNDEF
:
563 // A new undefined reference tells us nothing.
566 case DEF
* 16 + WEAK_UNDEF
:
567 case WEAK_DEF
* 16 + WEAK_UNDEF
:
568 case DYN_DEF
* 16 + WEAK_UNDEF
:
569 case DYN_WEAK_DEF
* 16 + WEAK_UNDEF
:
570 case UNDEF
* 16 + WEAK_UNDEF
:
571 case WEAK_UNDEF
* 16 + WEAK_UNDEF
:
572 case DYN_UNDEF
* 16 + WEAK_UNDEF
:
573 case DYN_WEAK_UNDEF
* 16 + WEAK_UNDEF
:
574 case COMMON
* 16 + WEAK_UNDEF
:
575 case WEAK_COMMON
* 16 + WEAK_UNDEF
:
576 case DYN_COMMON
* 16 + WEAK_UNDEF
:
577 case DYN_WEAK_COMMON
* 16 + WEAK_UNDEF
:
578 // A new weak undefined reference tells us nothing.
581 case DEF
* 16 + DYN_UNDEF
:
582 case WEAK_DEF
* 16 + DYN_UNDEF
:
583 case DYN_DEF
* 16 + DYN_UNDEF
:
584 case DYN_WEAK_DEF
* 16 + DYN_UNDEF
:
585 case UNDEF
* 16 + DYN_UNDEF
:
586 case WEAK_UNDEF
* 16 + DYN_UNDEF
:
587 case DYN_UNDEF
* 16 + DYN_UNDEF
:
588 case DYN_WEAK_UNDEF
* 16 + DYN_UNDEF
:
589 case COMMON
* 16 + DYN_UNDEF
:
590 case WEAK_COMMON
* 16 + DYN_UNDEF
:
591 case DYN_COMMON
* 16 + DYN_UNDEF
:
592 case DYN_WEAK_COMMON
* 16 + DYN_UNDEF
:
593 // A new dynamic undefined reference tells us nothing.
596 case DEF
* 16 + DYN_WEAK_UNDEF
:
597 case WEAK_DEF
* 16 + DYN_WEAK_UNDEF
:
598 case DYN_DEF
* 16 + DYN_WEAK_UNDEF
:
599 case DYN_WEAK_DEF
* 16 + DYN_WEAK_UNDEF
:
600 case UNDEF
* 16 + DYN_WEAK_UNDEF
:
601 case WEAK_UNDEF
* 16 + DYN_WEAK_UNDEF
:
602 case DYN_UNDEF
* 16 + DYN_WEAK_UNDEF
:
603 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_UNDEF
:
604 case COMMON
* 16 + DYN_WEAK_UNDEF
:
605 case WEAK_COMMON
* 16 + DYN_WEAK_UNDEF
:
606 case DYN_COMMON
* 16 + DYN_WEAK_UNDEF
:
607 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_UNDEF
:
608 // A new weak dynamic undefined reference tells us nothing.
611 case DEF
* 16 + COMMON
:
612 // A common symbol does not override a definition.
615 case WEAK_DEF
* 16 + COMMON
:
616 case DYN_DEF
* 16 + COMMON
:
617 case DYN_WEAK_DEF
* 16 + COMMON
:
618 // A common symbol does override a weak definition or a dynamic
622 case UNDEF
* 16 + COMMON
:
623 case WEAK_UNDEF
* 16 + COMMON
:
624 case DYN_UNDEF
* 16 + COMMON
:
625 case DYN_WEAK_UNDEF
* 16 + COMMON
:
626 // A common symbol is a definition for a reference.
629 case COMMON
* 16 + COMMON
:
630 // Set the size to the maximum.
631 *adjust_common_sizes
= true;
634 case WEAK_COMMON
* 16 + COMMON
:
635 // I'm not sure just what a weak common symbol means, but
636 // presumably it can be overridden by a regular common symbol.
639 case DYN_COMMON
* 16 + COMMON
:
640 case DYN_WEAK_COMMON
* 16 + COMMON
:
641 // Use the real common symbol, but adjust the size if necessary.
642 *adjust_common_sizes
= true;
645 case DEF
* 16 + WEAK_COMMON
:
646 case WEAK_DEF
* 16 + WEAK_COMMON
:
647 case DYN_DEF
* 16 + WEAK_COMMON
:
648 case DYN_WEAK_DEF
* 16 + WEAK_COMMON
:
649 // Whatever a weak common symbol is, it won't override a
653 case UNDEF
* 16 + WEAK_COMMON
:
654 case WEAK_UNDEF
* 16 + WEAK_COMMON
:
655 case DYN_UNDEF
* 16 + WEAK_COMMON
:
656 case DYN_WEAK_UNDEF
* 16 + WEAK_COMMON
:
657 // A weak common symbol is better than an undefined symbol.
660 case COMMON
* 16 + WEAK_COMMON
:
661 case WEAK_COMMON
* 16 + WEAK_COMMON
:
662 case DYN_COMMON
* 16 + WEAK_COMMON
:
663 case DYN_WEAK_COMMON
* 16 + WEAK_COMMON
:
664 // Ignore a weak common symbol in the presence of a real common
668 case DEF
* 16 + DYN_COMMON
:
669 case WEAK_DEF
* 16 + DYN_COMMON
:
670 case DYN_DEF
* 16 + DYN_COMMON
:
671 case DYN_WEAK_DEF
* 16 + DYN_COMMON
:
672 // Ignore a dynamic common symbol in the presence of a
676 case UNDEF
* 16 + DYN_COMMON
:
677 case WEAK_UNDEF
* 16 + DYN_COMMON
:
678 case DYN_UNDEF
* 16 + DYN_COMMON
:
679 case DYN_WEAK_UNDEF
* 16 + DYN_COMMON
:
680 // A dynamic common symbol is a definition of sorts.
683 case COMMON
* 16 + DYN_COMMON
:
684 case WEAK_COMMON
* 16 + DYN_COMMON
:
685 case DYN_COMMON
* 16 + DYN_COMMON
:
686 case DYN_WEAK_COMMON
* 16 + DYN_COMMON
:
687 // Set the size to the maximum.
688 *adjust_common_sizes
= true;
691 case DEF
* 16 + DYN_WEAK_COMMON
:
692 case WEAK_DEF
* 16 + DYN_WEAK_COMMON
:
693 case DYN_DEF
* 16 + DYN_WEAK_COMMON
:
694 case DYN_WEAK_DEF
* 16 + DYN_WEAK_COMMON
:
695 // A common symbol is ignored in the face of a definition.
698 case UNDEF
* 16 + DYN_WEAK_COMMON
:
699 case WEAK_UNDEF
* 16 + DYN_WEAK_COMMON
:
700 case DYN_UNDEF
* 16 + DYN_WEAK_COMMON
:
701 case DYN_WEAK_UNDEF
* 16 + DYN_WEAK_COMMON
:
702 // I guess a weak common symbol is better than a definition.
705 case COMMON
* 16 + DYN_WEAK_COMMON
:
706 case WEAK_COMMON
* 16 + DYN_WEAK_COMMON
:
707 case DYN_COMMON
* 16 + DYN_WEAK_COMMON
:
708 case DYN_WEAK_COMMON
* 16 + DYN_WEAK_COMMON
:
709 // Set the size to the maximum.
710 *adjust_common_sizes
= true;
718 // A special case of should_override which is only called for a strong
719 // defined symbol from a regular object file. This is used when
720 // defining special symbols.
723 Symbol_table::should_override_with_special(const Symbol
* to
)
725 bool adjust_common_sizes
;
726 unsigned int frombits
= global_flag
| regular_flag
| def_flag
;
727 bool ret
= Symbol_table::should_override(to
, frombits
, NULL
,
728 &adjust_common_sizes
);
729 gold_assert(!adjust_common_sizes
);
733 // Override symbol base with a special symbol.
736 Symbol::override_base_with_special(const Symbol
* from
)
738 gold_assert(this->name_
== from
->name_
|| this->has_alias());
740 this->source_
= from
->source_
;
741 switch (from
->source_
)
744 this->u_
.from_object
= from
->u_
.from_object
;
747 this->u_
.in_output_data
= from
->u_
.in_output_data
;
749 case IN_OUTPUT_SEGMENT
:
750 this->u_
.in_output_segment
= from
->u_
.in_output_segment
;
760 this->override_version(from
->version_
);
761 this->type_
= from
->type_
;
762 this->binding_
= from
->binding_
;
763 this->override_visibility(from
->visibility_
);
764 this->nonvis_
= from
->nonvis_
;
766 // Special symbols are always considered to be regular symbols.
767 this->in_reg_
= true;
769 if (from
->needs_dynsym_entry_
)
770 this->needs_dynsym_entry_
= true;
771 if (from
->needs_dynsym_value_
)
772 this->needs_dynsym_value_
= true;
774 // We shouldn't see these flags. If we do, we need to handle them
776 gold_assert(!from
->is_target_special_
|| this->is_target_special_
);
777 gold_assert(!from
->is_forwarder_
);
778 gold_assert(!from
->has_plt_offset_
);
779 gold_assert(!from
->has_warning_
);
780 gold_assert(!from
->is_copied_from_dynobj_
);
781 gold_assert(!from
->is_forced_local_
);
784 // Override a symbol with a special symbol.
788 Sized_symbol
<size
>::override_with_special(const Sized_symbol
<size
>* from
)
790 this->override_base_with_special(from
);
791 this->value_
= from
->value_
;
792 this->symsize_
= from
->symsize_
;
795 // Override TOSYM with the special symbol FROMSYM. This handles all
800 Symbol_table::override_with_special(Sized_symbol
<size
>* tosym
,
801 const Sized_symbol
<size
>* fromsym
)
803 tosym
->override_with_special(fromsym
);
804 if (tosym
->has_alias())
806 Symbol
* sym
= this->weak_aliases_
[tosym
];
807 gold_assert(sym
!= NULL
);
808 Sized_symbol
<size
>* ssym
= this->get_sized_symbol
<size
>(sym
);
811 ssym
->override_with_special(fromsym
);
812 sym
= this->weak_aliases_
[ssym
];
813 gold_assert(sym
!= NULL
);
814 ssym
= this->get_sized_symbol
<size
>(sym
);
816 while (ssym
!= tosym
);
818 if (tosym
->binding() == elfcpp::STB_LOCAL
819 || ((tosym
->visibility() == elfcpp::STV_HIDDEN
820 || tosym
->visibility() == elfcpp::STV_INTERNAL
)
821 && (tosym
->binding() == elfcpp::STB_GLOBAL
822 || tosym
->binding() == elfcpp::STB_WEAK
)
823 && !parameters
->options().relocatable()))
824 this->force_local(tosym
);
827 // Instantiate the templates we need. We could use the configure
828 // script to restrict this to only the ones needed for implemented
831 #ifdef HAVE_TARGET_32_LITTLE
834 Symbol_table::resolve
<32, false>(
835 Sized_symbol
<32>* to
,
836 const elfcpp::Sym
<32, false>& sym
,
837 unsigned int st_shndx
,
839 unsigned int orig_st_shndx
,
841 const char* version
);
844 #ifdef HAVE_TARGET_32_BIG
847 Symbol_table::resolve
<32, true>(
848 Sized_symbol
<32>* to
,
849 const elfcpp::Sym
<32, true>& sym
,
850 unsigned int st_shndx
,
852 unsigned int orig_st_shndx
,
854 const char* version
);
857 #ifdef HAVE_TARGET_64_LITTLE
860 Symbol_table::resolve
<64, false>(
861 Sized_symbol
<64>* to
,
862 const elfcpp::Sym
<64, false>& sym
,
863 unsigned int st_shndx
,
865 unsigned int orig_st_shndx
,
867 const char* version
);
870 #ifdef HAVE_TARGET_64_BIG
873 Symbol_table::resolve
<64, true>(
874 Sized_symbol
<64>* to
,
875 const elfcpp::Sym
<64, true>& sym
,
876 unsigned int st_shndx
,
878 unsigned int orig_st_shndx
,
880 const char* version
);
883 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
886 Symbol_table::override_with_special
<32>(Sized_symbol
<32>*,
887 const Sized_symbol
<32>*);
890 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
893 Symbol_table::override_with_special
<64>(Sized_symbol
<64>*,
894 const Sized_symbol
<64>*);
897 } // End namespace gold.