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 // A new weak undefined reference, merging with an old weak
301 // reference, could be a One Definition Rule (ODR) violation --
302 // especially if the types or sizes of the references differ. We'll
303 // store such pairs and look them up later to make sure they
304 // actually refer to the same lines of code. We also check
305 // combinations of weak and strong, which might occur if one case is
306 // inline and the other is not. (Note: not all ODR violations can
307 // be found this way, and not everything this finds is an ODR
308 // violation. But it's helpful to warn about.)
310 if (parameters->options().detect_odr_violations()
311 && (sym.get_st_bind() == elfcpp::STB_WEAK
312 || to->binding() == elfcpp::STB_WEAK)
313 && orig_st_shndx != elfcpp::SHN_UNDEF
314 && to->shndx(&to_is_ordinary) != elfcpp::SHN_UNDEF
316 && sym.get_st_size() != 0 // Ignore weird 0-sized symbols.
317 && to->symsize() != 0
318 && (sym.get_st_type() != to->type()
319 || sym.get_st_size() != to->symsize())
320 // C does not have a concept of ODR, so we only need to do this
321 // on C++ symbols. These have (mangled) names starting with _Z.
322 && to->name()[0] == '_' && to->name()[1] == 'Z')
324 Symbol_location fromloc
325 = { object, orig_st_shndx, sym.get_st_value() };
326 Symbol_location toloc = { to->object(), to->shndx(&to_is_ordinary),
328 this->candidate_odr_violations_[to->name()].insert(fromloc);
329 this->candidate_odr_violations_[to->name()].insert(toloc);
332 unsigned int frombits = symbol_to_bits(sym.get_st_bind(),
333 object->is_dynamic(),
334 st_shndx, is_ordinary,
337 bool adjust_common_sizes;
338 typename Sized_symbol<size>::Size_type tosize = to->symsize();
339 if (Symbol_table::should_override(to, frombits, OBJECT, object,
340 &adjust_common_sizes))
342 this->override(to, sym, st_shndx, is_ordinary, object, version);
343 if (adjust_common_sizes && tosize > to->symsize())
344 to->set_symsize(tosize);
348 if (adjust_common_sizes && sym.get_st_size() > tosize)
349 to->set_symsize(sym.get_st_size());
350 // The ELF ABI says that even for a reference to a symbol we
351 // merge the visibility.
352 to->override_visibility(sym.get_st_visibility());
355 if (adjust_common_sizes && parameters->options().warn_common())
357 if (tosize > sym.get_st_size())
358 Symbol_table::report_resolve_problem(false,
359 _("common of '%s' overriding "
362 else if (tosize < sym.get_st_size())
363 Symbol_table::report_resolve_problem(false,
364 _("common of '%s' overidden by "
368 Symbol_table::report_resolve_problem(false,
369 _("multiple common of '%s'"),
374 // Handle the core of symbol resolution. This is called with the
375 // existing symbol, TO, and a bitflag describing the new symbol. This
376 // returns true if we should override the existing symbol with the new
377 // one, and returns false otherwise. It sets *ADJUST_COMMON_SIZES to
378 // true if we should set the symbol size to the maximum of the TO and
379 // FROM sizes. It handles error conditions.
382 Symbol_table::should_override(const Symbol* to, unsigned int frombits,
383 Defined defined, Object* object,
384 bool* adjust_common_sizes)
386 *adjust_common_sizes = false;
389 if (to->source() == Symbol::IS_UNDEFINED)
390 tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_UNDEF, true,
392 else if (to->source() != Symbol::FROM_OBJECT)
393 tobits = symbol_to_bits(to->binding(), false, elfcpp::SHN_ABS, false,
398 unsigned int shndx = to->shndx(&is_ordinary);
399 tobits = symbol_to_bits(to->binding(),
400 to->object()->is_dynamic(),
406 // FIXME: Warn if either but not both of TO and SYM are STT_TLS.
408 // We use a giant switch table for symbol resolution. This code is
409 // unwieldy, but: 1) it is efficient; 2) we definitely handle all
410 // cases; 3) it is easy to change the handling of a particular case.
411 // The alternative would be a series of conditionals, but it is easy
412 // to get the ordering wrong. This could also be done as a table,
413 // but that is no easier to understand than this large switch
416 // These are the values generated by the bit codes.
419 DEF = global_flag | regular_flag | def_flag,
420 WEAK_DEF = weak_flag | regular_flag | def_flag,
421 DYN_DEF = global_flag | dynamic_flag | def_flag,
422 DYN_WEAK_DEF = weak_flag | dynamic_flag | def_flag,
423 UNDEF = global_flag | regular_flag | undef_flag,
424 WEAK_UNDEF = weak_flag | regular_flag | undef_flag,
425 DYN_UNDEF = global_flag | dynamic_flag | undef_flag,
426 DYN_WEAK_UNDEF = weak_flag | dynamic_flag | undef_flag,
427 COMMON = global_flag | regular_flag | common_flag,
428 WEAK_COMMON = weak_flag | regular_flag | common_flag,
429 DYN_COMMON = global_flag | dynamic_flag | common_flag,
430 DYN_WEAK_COMMON = weak_flag | dynamic_flag | common_flag
433 switch (tobits * 16 + frombits)
436 // Two definitions of the same symbol.
438 // If either symbol is defined by an object included using
439 // --just-symbols, then don't warn. This is for compatibility
440 // with the GNU linker. FIXME: This is a hack.
441 if ((to->source() == Symbol::FROM_OBJECT && to->object()->just_symbols())
442 || (object != NULL && object->just_symbols()))
445 if (!parameters->options().muldefs())
446 Symbol_table::report_resolve_problem(true,
447 _("multiple definition of '%s'"),
448 to, defined, object);
451 case WEAK_DEF * 16 + DEF:
452 // We've seen a weak definition, and now we see a strong
453 // definition. In the original SVR4 linker, this was treated as
454 // a multiple definition error. In the Solaris linker and the
455 // GNU linker, a weak definition followed by a regular
456 // definition causes the weak definition to be overridden. We
457 // are currently compatible with the GNU linker. In the future
458 // we should add a target specific option to change this.
462 case DYN_DEF * 16 + DEF:
463 case DYN_WEAK_DEF * 16 + DEF:
464 // We've seen a definition in a dynamic object, and now we see a
465 // definition in a regular object. The definition in the
466 // regular object overrides the definition in the dynamic
470 case UNDEF * 16 + DEF:
471 case WEAK_UNDEF * 16 + DEF:
472 case DYN_UNDEF * 16 + DEF:
473 case DYN_WEAK_UNDEF * 16 + DEF:
474 // We've seen an undefined reference, and now we see a
475 // definition. We use the definition.
478 case COMMON * 16 + DEF:
479 case WEAK_COMMON * 16 + DEF:
480 case DYN_COMMON * 16 + DEF:
481 case DYN_WEAK_COMMON * 16 + DEF:
482 // We've seen a common symbol and now we see a definition. The
483 // definition overrides.
484 if (parameters->options().warn_common())
485 Symbol_table::report_resolve_problem(false,
486 _("definition of '%s' overriding "
488 to, defined, object);
491 case DEF * 16 + WEAK_DEF:
492 case WEAK_DEF * 16 + WEAK_DEF:
493 // We've seen a definition and now we see a weak definition. We
494 // ignore the new weak definition.
497 case DYN_DEF * 16 + WEAK_DEF:
498 case DYN_WEAK_DEF * 16 + WEAK_DEF:
499 // We've seen a dynamic definition and now we see a regular weak
500 // definition. The regular weak definition overrides.
503 case UNDEF * 16 + WEAK_DEF:
504 case WEAK_UNDEF * 16 + WEAK_DEF:
505 case DYN_UNDEF * 16 + WEAK_DEF:
506 case DYN_WEAK_UNDEF * 16 + WEAK_DEF:
507 // A weak definition of a currently undefined symbol.
510 case COMMON * 16 + WEAK_DEF:
511 case WEAK_COMMON * 16 + WEAK_DEF:
512 // A weak definition does not override a common definition.
515 case DYN_COMMON * 16 + WEAK_DEF:
516 case DYN_WEAK_COMMON * 16 + WEAK_DEF:
517 // A weak definition does override a definition in a dynamic
519 if (parameters->options().warn_common())
520 Symbol_table::report_resolve_problem(false,
521 _("definition of '%s' overriding "
522 "dynamic common definition"),
523 to, defined, object);
526 case DEF * 16 + DYN_DEF:
527 case WEAK_DEF * 16 + DYN_DEF:
528 case DYN_DEF * 16 + DYN_DEF:
529 case DYN_WEAK_DEF * 16 + DYN_DEF:
530 // Ignore a dynamic definition if we already have a definition.
533 case UNDEF * 16 + DYN_DEF:
534 case WEAK_UNDEF * 16 + DYN_DEF:
535 case DYN_UNDEF * 16 + DYN_DEF:
536 case DYN_WEAK_UNDEF * 16 + DYN_DEF:
537 // Use a dynamic definition if we have a reference.
540 case COMMON * 16 + DYN_DEF:
541 case WEAK_COMMON * 16 + DYN_DEF:
542 case DYN_COMMON * 16 + DYN_DEF:
543 case DYN_WEAK_COMMON * 16 + DYN_DEF:
544 // Ignore a dynamic definition if we already have a common
548 case DEF * 16 + DYN_WEAK_DEF:
549 case WEAK_DEF * 16 + DYN_WEAK_DEF:
550 case DYN_DEF * 16 + DYN_WEAK_DEF:
551 case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF:
552 // Ignore a weak dynamic definition if we already have a
556 case UNDEF * 16 + DYN_WEAK_DEF:
557 case WEAK_UNDEF * 16 + DYN_WEAK_DEF:
558 case DYN_UNDEF * 16 + DYN_WEAK_DEF:
559 case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF:
560 // Use a weak dynamic definition if we have a reference.
563 case COMMON * 16 + DYN_WEAK_DEF:
564 case WEAK_COMMON * 16 + DYN_WEAK_DEF:
565 case DYN_COMMON * 16 + DYN_WEAK_DEF:
566 case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF:
567 // Ignore a weak dynamic definition if we already have a common
571 case DEF * 16 + UNDEF:
572 case WEAK_DEF * 16 + UNDEF:
573 case DYN_DEF * 16 + UNDEF:
574 case DYN_WEAK_DEF * 16 + UNDEF:
575 case UNDEF * 16 + UNDEF:
576 // A new undefined reference tells us nothing.
579 case WEAK_UNDEF * 16 + UNDEF:
580 case DYN_UNDEF * 16 + UNDEF:
581 case DYN_WEAK_UNDEF * 16 + UNDEF:
582 // A strong undef overrides a dynamic or weak undef.
585 case COMMON * 16 + UNDEF:
586 case WEAK_COMMON * 16 + UNDEF:
587 case DYN_COMMON * 16 + UNDEF:
588 case DYN_WEAK_COMMON * 16 + UNDEF:
589 // A new undefined reference tells us nothing.
592 case DEF * 16 + WEAK_UNDEF:
593 case WEAK_DEF * 16 + WEAK_UNDEF:
594 case DYN_DEF * 16 + WEAK_UNDEF:
595 case DYN_WEAK_DEF * 16 + WEAK_UNDEF:
596 case UNDEF * 16 + WEAK_UNDEF:
597 case WEAK_UNDEF * 16 + WEAK_UNDEF:
598 case DYN_UNDEF * 16 + WEAK_UNDEF:
599 case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF:
600 case COMMON * 16 + WEAK_UNDEF:
601 case WEAK_COMMON * 16 + WEAK_UNDEF:
602 case DYN_COMMON * 16 + WEAK_UNDEF:
603 case DYN_WEAK_COMMON * 16 + WEAK_UNDEF:
604 // A new weak undefined reference tells us nothing.
607 case DEF * 16 + DYN_UNDEF:
608 case WEAK_DEF * 16 + DYN_UNDEF:
609 case DYN_DEF * 16 + DYN_UNDEF:
610 case DYN_WEAK_DEF * 16 + DYN_UNDEF:
611 case UNDEF * 16 + DYN_UNDEF:
612 case WEAK_UNDEF * 16 + DYN_UNDEF:
613 case DYN_UNDEF * 16 + DYN_UNDEF:
614 case DYN_WEAK_UNDEF * 16 + DYN_UNDEF:
615 case COMMON * 16 + DYN_UNDEF:
616 case WEAK_COMMON * 16 + DYN_UNDEF:
617 case DYN_COMMON * 16 + DYN_UNDEF:
618 case DYN_WEAK_COMMON * 16 + DYN_UNDEF:
619 // A new dynamic undefined reference tells us nothing.
622 case DEF * 16 + DYN_WEAK_UNDEF:
623 case WEAK_DEF * 16 + DYN_WEAK_UNDEF:
624 case DYN_DEF * 16 + DYN_WEAK_UNDEF:
625 case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF:
626 case UNDEF * 16 + DYN_WEAK_UNDEF:
627 case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
628 case DYN_UNDEF * 16 + DYN_WEAK_UNDEF:
629 case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
630 case COMMON * 16 + DYN_WEAK_UNDEF:
631 case WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
632 case DYN_COMMON * 16 + DYN_WEAK_UNDEF:
633 case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
634 // A new weak dynamic undefined reference tells us nothing.
637 case DEF * 16 + COMMON:
638 // A common symbol does not override a definition.
639 if (parameters->options().warn_common())
640 Symbol_table::report_resolve_problem(false,
641 _("common '%s' overridden by "
642 "previous definition"),
643 to, defined, object);
646 case WEAK_DEF * 16 + COMMON:
647 case DYN_DEF * 16 + COMMON:
648 case DYN_WEAK_DEF * 16 + COMMON:
649 // A common symbol does override a weak definition or a dynamic
653 case UNDEF * 16 + COMMON:
654 case WEAK_UNDEF * 16 + COMMON:
655 case DYN_UNDEF * 16 + COMMON:
656 case DYN_WEAK_UNDEF * 16 + COMMON:
657 // A common symbol is a definition for a reference.
660 case COMMON * 16 + COMMON:
661 // Set the size to the maximum.
662 *adjust_common_sizes = true;
665 case WEAK_COMMON * 16 + COMMON:
666 // I'm not sure just what a weak common symbol means, but
667 // presumably it can be overridden by a regular common symbol.
670 case DYN_COMMON * 16 + COMMON:
671 case DYN_WEAK_COMMON * 16 + COMMON:
672 // Use the real common symbol, but adjust the size if necessary.
673 *adjust_common_sizes = true;
676 case DEF * 16 + WEAK_COMMON:
677 case WEAK_DEF * 16 + WEAK_COMMON:
678 case DYN_DEF * 16 + WEAK_COMMON:
679 case DYN_WEAK_DEF * 16 + WEAK_COMMON:
680 // Whatever a weak common symbol is, it won't override a
684 case UNDEF * 16 + WEAK_COMMON:
685 case WEAK_UNDEF * 16 + WEAK_COMMON:
686 case DYN_UNDEF * 16 + WEAK_COMMON:
687 case DYN_WEAK_UNDEF * 16 + WEAK_COMMON:
688 // A weak common symbol is better than an undefined symbol.
691 case COMMON * 16 + WEAK_COMMON:
692 case WEAK_COMMON * 16 + WEAK_COMMON:
693 case DYN_COMMON * 16 + WEAK_COMMON:
694 case DYN_WEAK_COMMON * 16 + WEAK_COMMON:
695 // Ignore a weak common symbol in the presence of a real common
699 case DEF * 16 + DYN_COMMON:
700 case WEAK_DEF * 16 + DYN_COMMON:
701 case DYN_DEF * 16 + DYN_COMMON:
702 case DYN_WEAK_DEF * 16 + DYN_COMMON:
703 // Ignore a dynamic common symbol in the presence of a
707 case UNDEF * 16 + DYN_COMMON:
708 case WEAK_UNDEF * 16 + DYN_COMMON:
709 case DYN_UNDEF * 16 + DYN_COMMON:
710 case DYN_WEAK_UNDEF * 16 + DYN_COMMON:
711 // A dynamic common symbol is a definition of sorts.
714 case COMMON * 16 + DYN_COMMON:
715 case WEAK_COMMON * 16 + DYN_COMMON:
716 case DYN_COMMON * 16 + DYN_COMMON:
717 case DYN_WEAK_COMMON * 16 + DYN_COMMON:
718 // Set the size to the maximum.
719 *adjust_common_sizes = true;
722 case DEF * 16 + DYN_WEAK_COMMON:
723 case WEAK_DEF * 16 + DYN_WEAK_COMMON:
724 case DYN_DEF * 16 + DYN_WEAK_COMMON:
725 case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON:
726 // A common symbol is ignored in the face of a definition.
729 case UNDEF * 16 + DYN_WEAK_COMMON:
730 case WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
731 case DYN_UNDEF * 16 + DYN_WEAK_COMMON:
732 case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
733 // I guess a weak common symbol is better than a definition.
736 case COMMON * 16 + DYN_WEAK_COMMON:
737 case WEAK_COMMON * 16 + DYN_WEAK_COMMON:
738 case DYN_COMMON * 16 + DYN_WEAK_COMMON:
739 case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON:
740 // Set the size to the maximum.
741 *adjust_common_sizes = true;
749 // Issue an error or warning due to symbol resolution. IS_ERROR
750 // indicates an error rather than a warning. MSG is the error
751 // message; it is expected to have a %s for the symbol name. TO is
752 // the existing symbol. DEFINED/OBJECT is where the new symbol was
755 // FIXME: We should have better location information here. When the
756 // symbol is defined, we should be able to pull the location from the
757 // debug info if there is any.
760 Symbol_table::report_resolve_problem(bool is_error, const char* msg,
761 const Symbol* to, Defined defined,
764 std::string demangled(to->demangled_name());
765 size_t len = strlen(msg) + demangled.length() + 10;
766 char* buf = new char[len];
767 snprintf(buf, len, msg, demangled.c_str());
773 objname = object->name().c_str();
776 objname = _("COPY reloc");
780 objname = _("command line");
783 objname = _("linker script");
786 objname = _("linker defined");
793 gold_error("%s: %s", objname, buf);
795 gold_warning("%s: %s", objname, buf);
799 if (to->source() == Symbol::FROM_OBJECT)
800 objname = to->object()->name().c_str();
802 objname = _("command line");
803 gold_info("%s: %s: previous definition here", program_name, objname);
806 // A special case of should_override which is only called for a strong
807 // defined symbol from a regular object file. This is used when
808 // defining special symbols.
811 Symbol_table::should_override_with_special(const Symbol* to, Defined defined)
813 bool adjust_common_sizes;
814 unsigned int frombits = global_flag | regular_flag | def_flag;
815 bool ret = Symbol_table::should_override(to, frombits, defined, NULL,
816 &adjust_common_sizes);
817 gold_assert(!adjust_common_sizes);
821 // Override symbol base with a special symbol.
824 Symbol::override_base_with_special(const Symbol* from)
826 gold_assert(this->name_ == from->name_ || this->has_alias());
828 this->source_ = from->source_;
829 switch (from->source_)
832 this->u_.from_object = from->u_.from_object;
835 this->u_.in_output_data = from->u_.in_output_data;
837 case IN_OUTPUT_SEGMENT:
838 this->u_.in_output_segment = from->u_.in_output_segment;
848 this->override_version(from->version_);
849 this->type_ = from->type_;
850 this->binding_ = from->binding_;
851 this->override_visibility(from->visibility_);
852 this->nonvis_ = from->nonvis_;
854 // Special symbols are always considered to be regular symbols.
855 this->in_reg_ = true;
857 if (from->needs_dynsym_entry_)
858 this->needs_dynsym_entry_ = true;
859 if (from->needs_dynsym_value_)
860 this->needs_dynsym_value_ = true;
862 // We shouldn't see these flags. If we do, we need to handle them
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 // We have to instantiate both big and little endian versions because
920 // these are used by other templates that depends on size only.
922 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
925 Symbol_table::resolve<32, false>(
926 Sized_symbol<32>* to,
927 const elfcpp::Sym<32, false>& sym,
928 unsigned int st_shndx,
930 unsigned int orig_st_shndx,
932 const char* version);
936 Symbol_table::resolve<32, true>(
937 Sized_symbol<32>* to,
938 const elfcpp::Sym<32, true>& sym,
939 unsigned int st_shndx,
941 unsigned int orig_st_shndx,
943 const char* version);
946 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
949 Symbol_table::resolve<64, false>(
950 Sized_symbol<64>* to,
951 const elfcpp::Sym<64, false>& sym,
952 unsigned int st_shndx,
954 unsigned int orig_st_shndx,
956 const char* version);
960 Symbol_table::resolve<64, true>(
961 Sized_symbol<64>* to,
962 const elfcpp::Sym<64, true>& sym,
963 unsigned int st_shndx,
965 unsigned int orig_st_shndx,
967 const char* version);
970 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
973 Symbol_table::override_with_special<32>(Sized_symbol<32>*,
974 const Sized_symbol<32>*);
977 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
980 Symbol_table::override_with_special<64>(Sized_symbol<64>*,
981 const Sized_symbol<64>*);
984 } // End namespace gold.