1 // resolve.cc -- symbol resolution for gold
3 // Copyright 2006, 2007, 2008, 2009, 2010 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().muldefs())
444 Symbol_table::report_resolve_problem(true,
445 _("multiple definition of '%s'"),
446 to, defined, object);
449 case WEAK_DEF * 16 + DEF:
450 // We've seen a weak definition, and now we see a strong
451 // definition. In the original SVR4 linker, this was treated as
452 // a multiple definition error. In the Solaris linker and the
453 // GNU linker, a weak definition followed by a regular
454 // definition causes the weak definition to be overridden. We
455 // are currently compatible with the GNU linker. In the future
456 // we should add a target specific option to change this.
460 case DYN_DEF * 16 + DEF:
461 case DYN_WEAK_DEF * 16 + DEF:
462 // We've seen a definition in a dynamic object, and now we see a
463 // definition in a regular object. The definition in the
464 // regular object overrides the definition in the dynamic
468 case UNDEF * 16 + DEF:
469 case WEAK_UNDEF * 16 + DEF:
470 case DYN_UNDEF * 16 + DEF:
471 case DYN_WEAK_UNDEF * 16 + DEF:
472 // We've seen an undefined reference, and now we see a
473 // definition. We use the definition.
476 case COMMON * 16 + DEF:
477 case WEAK_COMMON * 16 + DEF:
478 case DYN_COMMON * 16 + DEF:
479 case DYN_WEAK_COMMON * 16 + DEF:
480 // We've seen a common symbol and now we see a definition. The
481 // definition overrides.
482 if (parameters->options().warn_common())
483 Symbol_table::report_resolve_problem(false,
484 _("definition of '%s' overriding "
486 to, defined, object);
489 case DEF * 16 + WEAK_DEF:
490 case WEAK_DEF * 16 + WEAK_DEF:
491 // We've seen a definition and now we see a weak definition. We
492 // ignore the new weak definition.
495 case DYN_DEF * 16 + WEAK_DEF:
496 case DYN_WEAK_DEF * 16 + WEAK_DEF:
497 // We've seen a dynamic definition and now we see a regular weak
498 // definition. The regular weak definition overrides.
501 case UNDEF * 16 + WEAK_DEF:
502 case WEAK_UNDEF * 16 + WEAK_DEF:
503 case DYN_UNDEF * 16 + WEAK_DEF:
504 case DYN_WEAK_UNDEF * 16 + WEAK_DEF:
505 // A weak definition of a currently undefined symbol.
508 case COMMON * 16 + WEAK_DEF:
509 case WEAK_COMMON * 16 + WEAK_DEF:
510 // A weak definition does not override a common definition.
513 case DYN_COMMON * 16 + WEAK_DEF:
514 case DYN_WEAK_COMMON * 16 + WEAK_DEF:
515 // A weak definition does override a definition in a dynamic
517 if (parameters->options().warn_common())
518 Symbol_table::report_resolve_problem(false,
519 _("definition of '%s' overriding "
520 "dynamic common definition"),
521 to, defined, object);
524 case DEF * 16 + DYN_DEF:
525 case WEAK_DEF * 16 + DYN_DEF:
526 case DYN_DEF * 16 + DYN_DEF:
527 case DYN_WEAK_DEF * 16 + DYN_DEF:
528 // Ignore a dynamic definition if we already have a definition.
531 case UNDEF * 16 + DYN_DEF:
532 case WEAK_UNDEF * 16 + DYN_DEF:
533 case DYN_UNDEF * 16 + DYN_DEF:
534 case DYN_WEAK_UNDEF * 16 + DYN_DEF:
535 // Use a dynamic definition if we have a reference.
538 case COMMON * 16 + DYN_DEF:
539 case WEAK_COMMON * 16 + DYN_DEF:
540 case DYN_COMMON * 16 + DYN_DEF:
541 case DYN_WEAK_COMMON * 16 + DYN_DEF:
542 // Ignore a dynamic definition if we already have a common
546 case DEF * 16 + DYN_WEAK_DEF:
547 case WEAK_DEF * 16 + DYN_WEAK_DEF:
548 case DYN_DEF * 16 + DYN_WEAK_DEF:
549 case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF:
550 // Ignore a weak dynamic definition if we already have a
554 case UNDEF * 16 + DYN_WEAK_DEF:
555 case WEAK_UNDEF * 16 + DYN_WEAK_DEF:
556 case DYN_UNDEF * 16 + DYN_WEAK_DEF:
557 case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF:
558 // Use a weak dynamic definition if we have a reference.
561 case COMMON * 16 + DYN_WEAK_DEF:
562 case WEAK_COMMON * 16 + DYN_WEAK_DEF:
563 case DYN_COMMON * 16 + DYN_WEAK_DEF:
564 case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF:
565 // Ignore a weak dynamic definition if we already have a common
569 case DEF * 16 + UNDEF:
570 case WEAK_DEF * 16 + UNDEF:
571 case DYN_DEF * 16 + UNDEF:
572 case DYN_WEAK_DEF * 16 + UNDEF:
573 case UNDEF * 16 + UNDEF:
574 // A new undefined reference tells us nothing.
577 case WEAK_UNDEF * 16 + UNDEF:
578 case DYN_UNDEF * 16 + UNDEF:
579 case DYN_WEAK_UNDEF * 16 + UNDEF:
580 // A strong undef overrides a dynamic or weak undef.
583 case COMMON * 16 + UNDEF:
584 case WEAK_COMMON * 16 + UNDEF:
585 case DYN_COMMON * 16 + UNDEF:
586 case DYN_WEAK_COMMON * 16 + UNDEF:
587 // A new undefined reference tells us nothing.
590 case DEF * 16 + WEAK_UNDEF:
591 case WEAK_DEF * 16 + WEAK_UNDEF:
592 case DYN_DEF * 16 + WEAK_UNDEF:
593 case DYN_WEAK_DEF * 16 + WEAK_UNDEF:
594 case UNDEF * 16 + WEAK_UNDEF:
595 case WEAK_UNDEF * 16 + WEAK_UNDEF:
596 case DYN_UNDEF * 16 + WEAK_UNDEF:
597 case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF:
598 case COMMON * 16 + WEAK_UNDEF:
599 case WEAK_COMMON * 16 + WEAK_UNDEF:
600 case DYN_COMMON * 16 + WEAK_UNDEF:
601 case DYN_WEAK_COMMON * 16 + WEAK_UNDEF:
602 // A new weak undefined reference tells us nothing.
605 case DEF * 16 + DYN_UNDEF:
606 case WEAK_DEF * 16 + DYN_UNDEF:
607 case DYN_DEF * 16 + DYN_UNDEF:
608 case DYN_WEAK_DEF * 16 + DYN_UNDEF:
609 case UNDEF * 16 + DYN_UNDEF:
610 case WEAK_UNDEF * 16 + DYN_UNDEF:
611 case DYN_UNDEF * 16 + DYN_UNDEF:
612 case DYN_WEAK_UNDEF * 16 + DYN_UNDEF:
613 case COMMON * 16 + DYN_UNDEF:
614 case WEAK_COMMON * 16 + DYN_UNDEF:
615 case DYN_COMMON * 16 + DYN_UNDEF:
616 case DYN_WEAK_COMMON * 16 + DYN_UNDEF:
617 // A new dynamic undefined reference tells us nothing.
620 case DEF * 16 + DYN_WEAK_UNDEF:
621 case WEAK_DEF * 16 + DYN_WEAK_UNDEF:
622 case DYN_DEF * 16 + DYN_WEAK_UNDEF:
623 case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF:
624 case UNDEF * 16 + DYN_WEAK_UNDEF:
625 case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
626 case DYN_UNDEF * 16 + DYN_WEAK_UNDEF:
627 case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
628 case COMMON * 16 + DYN_WEAK_UNDEF:
629 case WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
630 case DYN_COMMON * 16 + DYN_WEAK_UNDEF:
631 case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
632 // A new weak dynamic undefined reference tells us nothing.
635 case DEF * 16 + COMMON:
636 // A common symbol does not override a definition.
637 if (parameters->options().warn_common())
638 Symbol_table::report_resolve_problem(false,
639 _("common '%s' overridden by "
640 "previous definition"),
641 to, defined, object);
644 case WEAK_DEF * 16 + COMMON:
645 case DYN_DEF * 16 + COMMON:
646 case DYN_WEAK_DEF * 16 + COMMON:
647 // A common symbol does override a weak definition or a dynamic
651 case UNDEF * 16 + COMMON:
652 case WEAK_UNDEF * 16 + COMMON:
653 case DYN_UNDEF * 16 + COMMON:
654 case DYN_WEAK_UNDEF * 16 + COMMON:
655 // A common symbol is a definition for a reference.
658 case COMMON * 16 + COMMON:
659 // Set the size to the maximum.
660 *adjust_common_sizes = true;
663 case WEAK_COMMON * 16 + COMMON:
664 // I'm not sure just what a weak common symbol means, but
665 // presumably it can be overridden by a regular common symbol.
668 case DYN_COMMON * 16 + COMMON:
669 case DYN_WEAK_COMMON * 16 + COMMON:
670 // Use the real common symbol, but adjust the size if necessary.
671 *adjust_common_sizes = true;
674 case DEF * 16 + WEAK_COMMON:
675 case WEAK_DEF * 16 + WEAK_COMMON:
676 case DYN_DEF * 16 + WEAK_COMMON:
677 case DYN_WEAK_DEF * 16 + WEAK_COMMON:
678 // Whatever a weak common symbol is, it won't override a
682 case UNDEF * 16 + WEAK_COMMON:
683 case WEAK_UNDEF * 16 + WEAK_COMMON:
684 case DYN_UNDEF * 16 + WEAK_COMMON:
685 case DYN_WEAK_UNDEF * 16 + WEAK_COMMON:
686 // A weak common symbol is better than an undefined symbol.
689 case COMMON * 16 + WEAK_COMMON:
690 case WEAK_COMMON * 16 + WEAK_COMMON:
691 case DYN_COMMON * 16 + WEAK_COMMON:
692 case DYN_WEAK_COMMON * 16 + WEAK_COMMON:
693 // Ignore a weak common symbol in the presence of a real common
697 case DEF * 16 + DYN_COMMON:
698 case WEAK_DEF * 16 + DYN_COMMON:
699 case DYN_DEF * 16 + DYN_COMMON:
700 case DYN_WEAK_DEF * 16 + DYN_COMMON:
701 // Ignore a dynamic common symbol in the presence of a
705 case UNDEF * 16 + DYN_COMMON:
706 case WEAK_UNDEF * 16 + DYN_COMMON:
707 case DYN_UNDEF * 16 + DYN_COMMON:
708 case DYN_WEAK_UNDEF * 16 + DYN_COMMON:
709 // A dynamic common symbol is a definition of sorts.
712 case COMMON * 16 + DYN_COMMON:
713 case WEAK_COMMON * 16 + DYN_COMMON:
714 case DYN_COMMON * 16 + DYN_COMMON:
715 case DYN_WEAK_COMMON * 16 + DYN_COMMON:
716 // Set the size to the maximum.
717 *adjust_common_sizes = true;
720 case DEF * 16 + DYN_WEAK_COMMON:
721 case WEAK_DEF * 16 + DYN_WEAK_COMMON:
722 case DYN_DEF * 16 + DYN_WEAK_COMMON:
723 case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON:
724 // A common symbol is ignored in the face of a definition.
727 case UNDEF * 16 + DYN_WEAK_COMMON:
728 case WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
729 case DYN_UNDEF * 16 + DYN_WEAK_COMMON:
730 case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
731 // I guess a weak common symbol is better than a definition.
734 case COMMON * 16 + DYN_WEAK_COMMON:
735 case WEAK_COMMON * 16 + DYN_WEAK_COMMON:
736 case DYN_COMMON * 16 + DYN_WEAK_COMMON:
737 case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON:
738 // Set the size to the maximum.
739 *adjust_common_sizes = true;
747 // Issue an error or warning due to symbol resolution. IS_ERROR
748 // indicates an error rather than a warning. MSG is the error
749 // message; it is expected to have a %s for the symbol name. TO is
750 // the existing symbol. DEFINED/OBJECT is where the new symbol was
753 // FIXME: We should have better location information here. When the
754 // symbol is defined, we should be able to pull the location from the
755 // debug info if there is any.
758 Symbol_table::report_resolve_problem(bool is_error, const char* msg,
759 const Symbol* to, Defined defined,
762 std::string demangled(to->demangled_name());
763 size_t len = strlen(msg) + demangled.length() + 10;
764 char* buf = new char[len];
765 snprintf(buf, len, msg, demangled.c_str());
771 objname = object->name().c_str();
774 objname = _("COPY reloc");
778 objname = _("command line");
781 objname = _("linker script");
784 objname = _("linker defined");
791 gold_error("%s: %s", objname, buf);
793 gold_warning("%s: %s", objname, buf);
797 if (to->source() == Symbol::FROM_OBJECT)
798 objname = to->object()->name().c_str();
800 objname = _("command line");
801 gold_info("%s: %s: previous definition here", program_name, objname);
804 // A special case of should_override which is only called for a strong
805 // defined symbol from a regular object file. This is used when
806 // defining special symbols.
809 Symbol_table::should_override_with_special(const Symbol* to, Defined defined)
811 bool adjust_common_sizes;
812 unsigned int frombits = global_flag | regular_flag | def_flag;
813 bool ret = Symbol_table::should_override(to, frombits, defined, NULL,
814 &adjust_common_sizes);
815 gold_assert(!adjust_common_sizes);
819 // Override symbol base with a special symbol.
822 Symbol::override_base_with_special(const Symbol* from)
824 gold_assert(this->name_ == from->name_ || this->has_alias());
826 this->source_ = from->source_;
827 switch (from->source_)
830 this->u_.from_object = from->u_.from_object;
833 this->u_.in_output_data = from->u_.in_output_data;
835 case IN_OUTPUT_SEGMENT:
836 this->u_.in_output_segment = from->u_.in_output_segment;
846 this->override_version(from->version_);
847 this->type_ = from->type_;
848 this->binding_ = from->binding_;
849 this->override_visibility(from->visibility_);
850 this->nonvis_ = from->nonvis_;
852 // Special symbols are always considered to be regular symbols.
853 this->in_reg_ = true;
855 if (from->needs_dynsym_entry_)
856 this->needs_dynsym_entry_ = true;
857 if (from->needs_dynsym_value_)
858 this->needs_dynsym_value_ = true;
860 // We shouldn't see these flags. If we do, we need to handle them
862 gold_assert(!from->is_forwarder_);
863 gold_assert(!from->has_plt_offset());
864 gold_assert(!from->has_warning_);
865 gold_assert(!from->is_copied_from_dynobj_);
866 gold_assert(!from->is_forced_local_);
869 // Override a symbol with a special symbol.
873 Sized_symbol<size>::override_with_special(const Sized_symbol<size>* from)
875 this->override_base_with_special(from);
876 this->value_ = from->value_;
877 this->symsize_ = from->symsize_;
880 // Override TOSYM with the special symbol FROMSYM. This handles all
885 Symbol_table::override_with_special(Sized_symbol<size>* tosym,
886 const Sized_symbol<size>* fromsym)
888 tosym->override_with_special(fromsym);
889 if (tosym->has_alias())
891 Symbol* sym = this->weak_aliases_[tosym];
892 gold_assert(sym != NULL);
893 Sized_symbol<size>* ssym = this->get_sized_symbol<size>(sym);
896 ssym->override_with_special(fromsym);
897 sym = this->weak_aliases_[ssym];
898 gold_assert(sym != NULL);
899 ssym = this->get_sized_symbol<size>(sym);
901 while (ssym != tosym);
903 if (tosym->binding() == elfcpp::STB_LOCAL
904 || ((tosym->visibility() == elfcpp::STV_HIDDEN
905 || tosym->visibility() == elfcpp::STV_INTERNAL)
906 && (tosym->binding() == elfcpp::STB_GLOBAL
907 || tosym->binding() == elfcpp::STB_GNU_UNIQUE
908 || tosym->binding() == elfcpp::STB_WEAK)
909 && !parameters->options().relocatable()))
910 this->force_local(tosym);
913 // Instantiate the templates we need. We could use the configure
914 // script to restrict this to only the ones needed for implemented
917 #ifdef HAVE_TARGET_32_LITTLE
920 Symbol_table::resolve<32, false>(
921 Sized_symbol<32>* to,
922 const elfcpp::Sym<32, false>& sym,
923 unsigned int st_shndx,
925 unsigned int orig_st_shndx,
927 const char* version);
930 #ifdef HAVE_TARGET_32_BIG
933 Symbol_table::resolve<32, true>(
934 Sized_symbol<32>* to,
935 const elfcpp::Sym<32, true>& sym,
936 unsigned int st_shndx,
938 unsigned int orig_st_shndx,
940 const char* version);
943 #ifdef HAVE_TARGET_64_LITTLE
946 Symbol_table::resolve<64, false>(
947 Sized_symbol<64>* to,
948 const elfcpp::Sym<64, false>& sym,
949 unsigned int st_shndx,
951 unsigned int orig_st_shndx,
953 const char* version);
956 #ifdef HAVE_TARGET_64_BIG
959 Symbol_table::resolve<64, true>(
960 Sized_symbol<64>* to,
961 const elfcpp::Sym<64, true>& sym,
962 unsigned int st_shndx,
964 unsigned int orig_st_shndx,
966 const char* version);
969 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
972 Symbol_table::override_with_special<32>(Sized_symbol<32>*,
973 const Sized_symbol<32>*);
976 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
979 Symbol_table::override_with_special<64>(Sized_symbol<64>*,
980 const Sized_symbol<64>*);
983 } // End namespace gold.