* symtab.h (class Symbol_table): Add enum Defined.
[deliverable/binutils-gdb.git] / gold / symtab.cc
1 // symtab.cc -- the gold symbol table
2
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
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.
12
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.
17
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.
22
23 #include "gold.h"
24
25 #include <cstring>
26 #include <stdint.h>
27 #include <algorithm>
28 #include <set>
29 #include <string>
30 #include <utility>
31 #include "demangle.h"
32
33 #include "gc.h"
34 #include "object.h"
35 #include "dwarf_reader.h"
36 #include "dynobj.h"
37 #include "output.h"
38 #include "target.h"
39 #include "workqueue.h"
40 #include "symtab.h"
41 #include "demangle.h" // needed for --dynamic-list-cpp-new
42 #include "plugin.h"
43
44 namespace gold
45 {
46
47 // Class Symbol.
48
49 // Initialize fields in Symbol. This initializes everything except u_
50 // and source_.
51
52 void
53 Symbol::init_fields(const char* name, const char* version,
54 elfcpp::STT type, elfcpp::STB binding,
55 elfcpp::STV visibility, unsigned char nonvis)
56 {
57 this->name_ = name;
58 this->version_ = version;
59 this->symtab_index_ = 0;
60 this->dynsym_index_ = 0;
61 this->got_offsets_.init();
62 this->plt_offset_ = 0;
63 this->type_ = type;
64 this->binding_ = binding;
65 this->visibility_ = visibility;
66 this->nonvis_ = nonvis;
67 this->is_target_special_ = false;
68 this->is_def_ = false;
69 this->is_forwarder_ = false;
70 this->has_alias_ = false;
71 this->needs_dynsym_entry_ = false;
72 this->in_reg_ = false;
73 this->in_dyn_ = false;
74 this->has_plt_offset_ = false;
75 this->has_warning_ = false;
76 this->is_copied_from_dynobj_ = false;
77 this->is_forced_local_ = false;
78 this->is_ordinary_shndx_ = false;
79 this->in_real_elf_ = false;
80 }
81
82 // Return the demangled version of the symbol's name, but only
83 // if the --demangle flag was set.
84
85 static std::string
86 demangle(const char* name)
87 {
88 if (!parameters->options().do_demangle())
89 return name;
90
91 // cplus_demangle allocates memory for the result it returns,
92 // and returns NULL if the name is already demangled.
93 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
94 if (demangled_name == NULL)
95 return name;
96
97 std::string retval(demangled_name);
98 free(demangled_name);
99 return retval;
100 }
101
102 std::string
103 Symbol::demangled_name() const
104 {
105 return demangle(this->name());
106 }
107
108 // Initialize the fields in the base class Symbol for SYM in OBJECT.
109
110 template<int size, bool big_endian>
111 void
112 Symbol::init_base_object(const char* name, const char* version, Object* object,
113 const elfcpp::Sym<size, big_endian>& sym,
114 unsigned int st_shndx, bool is_ordinary)
115 {
116 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
117 sym.get_st_visibility(), sym.get_st_nonvis());
118 this->u_.from_object.object = object;
119 this->u_.from_object.shndx = st_shndx;
120 this->is_ordinary_shndx_ = is_ordinary;
121 this->source_ = FROM_OBJECT;
122 this->in_reg_ = !object->is_dynamic();
123 this->in_dyn_ = object->is_dynamic();
124 this->in_real_elf_ = object->pluginobj() == NULL;
125 }
126
127 // Initialize the fields in the base class Symbol for a symbol defined
128 // in an Output_data.
129
130 void
131 Symbol::init_base_output_data(const char* name, const char* version,
132 Output_data* od, elfcpp::STT type,
133 elfcpp::STB binding, elfcpp::STV visibility,
134 unsigned char nonvis, bool offset_is_from_end)
135 {
136 this->init_fields(name, version, type, binding, visibility, nonvis);
137 this->u_.in_output_data.output_data = od;
138 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
139 this->source_ = IN_OUTPUT_DATA;
140 this->in_reg_ = true;
141 this->in_real_elf_ = true;
142 }
143
144 // Initialize the fields in the base class Symbol for a symbol defined
145 // in an Output_segment.
146
147 void
148 Symbol::init_base_output_segment(const char* name, const char* version,
149 Output_segment* os, elfcpp::STT type,
150 elfcpp::STB binding, elfcpp::STV visibility,
151 unsigned char nonvis,
152 Segment_offset_base offset_base)
153 {
154 this->init_fields(name, version, type, binding, visibility, nonvis);
155 this->u_.in_output_segment.output_segment = os;
156 this->u_.in_output_segment.offset_base = offset_base;
157 this->source_ = IN_OUTPUT_SEGMENT;
158 this->in_reg_ = true;
159 this->in_real_elf_ = true;
160 }
161
162 // Initialize the fields in the base class Symbol for a symbol defined
163 // as a constant.
164
165 void
166 Symbol::init_base_constant(const char* name, const char* version,
167 elfcpp::STT type, elfcpp::STB binding,
168 elfcpp::STV visibility, unsigned char nonvis)
169 {
170 this->init_fields(name, version, type, binding, visibility, nonvis);
171 this->source_ = IS_CONSTANT;
172 this->in_reg_ = true;
173 this->in_real_elf_ = true;
174 }
175
176 // Initialize the fields in the base class Symbol for an undefined
177 // symbol.
178
179 void
180 Symbol::init_base_undefined(const char* name, const char* version,
181 elfcpp::STT type, elfcpp::STB binding,
182 elfcpp::STV visibility, unsigned char nonvis)
183 {
184 this->init_fields(name, version, type, binding, visibility, nonvis);
185 this->dynsym_index_ = -1U;
186 this->source_ = IS_UNDEFINED;
187 this->in_reg_ = true;
188 this->in_real_elf_ = true;
189 }
190
191 // Allocate a common symbol in the base.
192
193 void
194 Symbol::allocate_base_common(Output_data* od)
195 {
196 gold_assert(this->is_common());
197 this->source_ = IN_OUTPUT_DATA;
198 this->u_.in_output_data.output_data = od;
199 this->u_.in_output_data.offset_is_from_end = false;
200 }
201
202 // Initialize the fields in Sized_symbol for SYM in OBJECT.
203
204 template<int size>
205 template<bool big_endian>
206 void
207 Sized_symbol<size>::init_object(const char* name, const char* version,
208 Object* object,
209 const elfcpp::Sym<size, big_endian>& sym,
210 unsigned int st_shndx, bool is_ordinary)
211 {
212 this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
213 this->value_ = sym.get_st_value();
214 this->symsize_ = sym.get_st_size();
215 }
216
217 // Initialize the fields in Sized_symbol for a symbol defined in an
218 // Output_data.
219
220 template<int size>
221 void
222 Sized_symbol<size>::init_output_data(const char* name, const char* version,
223 Output_data* od, Value_type value,
224 Size_type symsize, elfcpp::STT type,
225 elfcpp::STB binding,
226 elfcpp::STV visibility,
227 unsigned char nonvis,
228 bool offset_is_from_end)
229 {
230 this->init_base_output_data(name, version, od, type, binding, visibility,
231 nonvis, offset_is_from_end);
232 this->value_ = value;
233 this->symsize_ = symsize;
234 }
235
236 // Initialize the fields in Sized_symbol for a symbol defined in an
237 // Output_segment.
238
239 template<int size>
240 void
241 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
242 Output_segment* os, Value_type value,
243 Size_type symsize, elfcpp::STT type,
244 elfcpp::STB binding,
245 elfcpp::STV visibility,
246 unsigned char nonvis,
247 Segment_offset_base offset_base)
248 {
249 this->init_base_output_segment(name, version, os, type, binding, visibility,
250 nonvis, offset_base);
251 this->value_ = value;
252 this->symsize_ = symsize;
253 }
254
255 // Initialize the fields in Sized_symbol for a symbol defined as a
256 // constant.
257
258 template<int size>
259 void
260 Sized_symbol<size>::init_constant(const char* name, const char* version,
261 Value_type value, Size_type symsize,
262 elfcpp::STT type, elfcpp::STB binding,
263 elfcpp::STV visibility, unsigned char nonvis)
264 {
265 this->init_base_constant(name, version, type, binding, visibility, nonvis);
266 this->value_ = value;
267 this->symsize_ = symsize;
268 }
269
270 // Initialize the fields in Sized_symbol for an undefined symbol.
271
272 template<int size>
273 void
274 Sized_symbol<size>::init_undefined(const char* name, const char* version,
275 elfcpp::STT type, elfcpp::STB binding,
276 elfcpp::STV visibility, unsigned char nonvis)
277 {
278 this->init_base_undefined(name, version, type, binding, visibility, nonvis);
279 this->value_ = 0;
280 this->symsize_ = 0;
281 }
282
283 // Return true if SHNDX represents a common symbol.
284
285 bool
286 Symbol::is_common_shndx(unsigned int shndx)
287 {
288 return (shndx == elfcpp::SHN_COMMON
289 || shndx == parameters->target().small_common_shndx()
290 || shndx == parameters->target().large_common_shndx());
291 }
292
293 // Allocate a common symbol.
294
295 template<int size>
296 void
297 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
298 {
299 this->allocate_base_common(od);
300 this->value_ = value;
301 }
302
303 // The ""'s around str ensure str is a string literal, so sizeof works.
304 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
305
306 // Return true if this symbol should be added to the dynamic symbol
307 // table.
308
309 inline bool
310 Symbol::should_add_dynsym_entry() const
311 {
312 // If the symbol is used by a dynamic relocation, we need to add it.
313 if (this->needs_dynsym_entry())
314 return true;
315
316 // If this symbol's section is not added, the symbol need not be added.
317 // The section may have been GCed. Note that export_dynamic is being
318 // overridden here. This should not be done for shared objects.
319 if (parameters->options().gc_sections()
320 && !parameters->options().shared()
321 && this->source() == Symbol::FROM_OBJECT
322 && !this->object()->is_dynamic())
323 {
324 Relobj* relobj = static_cast<Relobj*>(this->object());
325 bool is_ordinary;
326 unsigned int shndx = this->shndx(&is_ordinary);
327 if (is_ordinary && shndx != elfcpp::SHN_UNDEF
328 && !relobj->is_section_included(shndx))
329 return false;
330 }
331
332 // If the symbol was forced local in a version script, do not add it.
333 if (this->is_forced_local())
334 return false;
335
336 // If the symbol was forced dynamic in a --dynamic-list file, add it.
337 if (parameters->options().in_dynamic_list(this->name()))
338 return true;
339
340 // If dynamic-list-data was specified, add any STT_OBJECT.
341 if (parameters->options().dynamic_list_data()
342 && !this->is_from_dynobj()
343 && this->type() == elfcpp::STT_OBJECT)
344 return true;
345
346 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
347 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
348 if ((parameters->options().dynamic_list_cpp_new()
349 || parameters->options().dynamic_list_cpp_typeinfo())
350 && !this->is_from_dynobj())
351 {
352 // TODO(csilvers): We could probably figure out if we're an operator
353 // new/delete or typeinfo without the need to demangle.
354 char* demangled_name = cplus_demangle(this->name(),
355 DMGL_ANSI | DMGL_PARAMS);
356 if (demangled_name == NULL)
357 {
358 // Not a C++ symbol, so it can't satisfy these flags
359 }
360 else if (parameters->options().dynamic_list_cpp_new()
361 && (strprefix(demangled_name, "operator new")
362 || strprefix(demangled_name, "operator delete")))
363 {
364 free(demangled_name);
365 return true;
366 }
367 else if (parameters->options().dynamic_list_cpp_typeinfo()
368 && (strprefix(demangled_name, "typeinfo name for")
369 || strprefix(demangled_name, "typeinfo for")))
370 {
371 free(demangled_name);
372 return true;
373 }
374 else
375 free(demangled_name);
376 }
377
378 // If exporting all symbols or building a shared library,
379 // and the symbol is defined in a regular object and is
380 // externally visible, we need to add it.
381 if ((parameters->options().export_dynamic() || parameters->options().shared())
382 && !this->is_from_dynobj()
383 && this->is_externally_visible())
384 return true;
385
386 return false;
387 }
388
389 // Return true if the final value of this symbol is known at link
390 // time.
391
392 bool
393 Symbol::final_value_is_known() const
394 {
395 // If we are not generating an executable, then no final values are
396 // known, since they will change at runtime.
397 if (parameters->options().output_is_position_independent()
398 || parameters->options().relocatable())
399 return false;
400
401 // If the symbol is not from an object file, and is not undefined,
402 // then it is defined, and known.
403 if (this->source_ != FROM_OBJECT)
404 {
405 if (this->source_ != IS_UNDEFINED)
406 return true;
407 }
408 else
409 {
410 // If the symbol is from a dynamic object, then the final value
411 // is not known.
412 if (this->object()->is_dynamic())
413 return false;
414
415 // If the symbol is not undefined (it is defined or common),
416 // then the final value is known.
417 if (!this->is_undefined())
418 return true;
419 }
420
421 // If the symbol is undefined, then whether the final value is known
422 // depends on whether we are doing a static link. If we are doing a
423 // dynamic link, then the final value could be filled in at runtime.
424 // This could reasonably be the case for a weak undefined symbol.
425 return parameters->doing_static_link();
426 }
427
428 // Return the output section where this symbol is defined.
429
430 Output_section*
431 Symbol::output_section() const
432 {
433 switch (this->source_)
434 {
435 case FROM_OBJECT:
436 {
437 unsigned int shndx = this->u_.from_object.shndx;
438 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
439 {
440 gold_assert(!this->u_.from_object.object->is_dynamic());
441 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
442 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
443 return relobj->output_section(shndx);
444 }
445 return NULL;
446 }
447
448 case IN_OUTPUT_DATA:
449 return this->u_.in_output_data.output_data->output_section();
450
451 case IN_OUTPUT_SEGMENT:
452 case IS_CONSTANT:
453 case IS_UNDEFINED:
454 return NULL;
455
456 default:
457 gold_unreachable();
458 }
459 }
460
461 // Set the symbol's output section. This is used for symbols defined
462 // in scripts. This should only be called after the symbol table has
463 // been finalized.
464
465 void
466 Symbol::set_output_section(Output_section* os)
467 {
468 switch (this->source_)
469 {
470 case FROM_OBJECT:
471 case IN_OUTPUT_DATA:
472 gold_assert(this->output_section() == os);
473 break;
474 case IS_CONSTANT:
475 this->source_ = IN_OUTPUT_DATA;
476 this->u_.in_output_data.output_data = os;
477 this->u_.in_output_data.offset_is_from_end = false;
478 break;
479 case IN_OUTPUT_SEGMENT:
480 case IS_UNDEFINED:
481 default:
482 gold_unreachable();
483 }
484 }
485
486 // Class Symbol_table.
487
488 Symbol_table::Symbol_table(unsigned int count,
489 const Version_script_info& version_script)
490 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
491 forwarders_(), commons_(), tls_commons_(), small_commons_(),
492 large_commons_(), forced_locals_(), warnings_(),
493 version_script_(version_script), gc_(NULL), icf_(NULL)
494 {
495 namepool_.reserve(count);
496 }
497
498 Symbol_table::~Symbol_table()
499 {
500 }
501
502 // The hash function. The key values are Stringpool keys.
503
504 inline size_t
505 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
506 {
507 return key.first ^ key.second;
508 }
509
510 // The symbol table key equality function. This is called with
511 // Stringpool keys.
512
513 inline bool
514 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
515 const Symbol_table_key& k2) const
516 {
517 return k1.first == k2.first && k1.second == k2.second;
518 }
519
520 bool
521 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
522 {
523 return (parameters->options().icf_enabled()
524 && this->icf_->is_section_folded(obj, shndx));
525 }
526
527 // For symbols that have been listed with -u option, add them to the
528 // work list to avoid gc'ing them.
529
530 void
531 Symbol_table::gc_mark_undef_symbols()
532 {
533 for (options::String_set::const_iterator p =
534 parameters->options().undefined_begin();
535 p != parameters->options().undefined_end();
536 ++p)
537 {
538 const char* name = p->c_str();
539 Symbol* sym = this->lookup(name);
540 gold_assert (sym != NULL);
541 if (sym->source() == Symbol::FROM_OBJECT
542 && !sym->object()->is_dynamic())
543 {
544 Relobj* obj = static_cast<Relobj*>(sym->object());
545 bool is_ordinary;
546 unsigned int shndx = sym->shndx(&is_ordinary);
547 if (is_ordinary)
548 {
549 gold_assert(this->gc_ != NULL);
550 this->gc_->worklist().push(Section_id(obj, shndx));
551 }
552 }
553 }
554 }
555
556 void
557 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
558 {
559 if (!sym->is_from_dynobj()
560 && sym->is_externally_visible())
561 {
562 //Add the object and section to the work list.
563 Relobj* obj = static_cast<Relobj*>(sym->object());
564 bool is_ordinary;
565 unsigned int shndx = sym->shndx(&is_ordinary);
566 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
567 {
568 gold_assert(this->gc_!= NULL);
569 this->gc_->worklist().push(Section_id(obj, shndx));
570 }
571 }
572 }
573
574 // When doing garbage collection, keep symbols that have been seen in
575 // dynamic objects.
576 inline void
577 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
578 {
579 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
580 && !sym->object()->is_dynamic())
581 {
582 Relobj *obj = static_cast<Relobj*>(sym->object());
583 bool is_ordinary;
584 unsigned int shndx = sym->shndx(&is_ordinary);
585 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
586 {
587 gold_assert(this->gc_ != NULL);
588 this->gc_->worklist().push(Section_id(obj, shndx));
589 }
590 }
591 }
592
593 // Make TO a symbol which forwards to FROM.
594
595 void
596 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
597 {
598 gold_assert(from != to);
599 gold_assert(!from->is_forwarder() && !to->is_forwarder());
600 this->forwarders_[from] = to;
601 from->set_forwarder();
602 }
603
604 // Resolve the forwards from FROM, returning the real symbol.
605
606 Symbol*
607 Symbol_table::resolve_forwards(const Symbol* from) const
608 {
609 gold_assert(from->is_forwarder());
610 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
611 this->forwarders_.find(from);
612 gold_assert(p != this->forwarders_.end());
613 return p->second;
614 }
615
616 // Look up a symbol by name.
617
618 Symbol*
619 Symbol_table::lookup(const char* name, const char* version) const
620 {
621 Stringpool::Key name_key;
622 name = this->namepool_.find(name, &name_key);
623 if (name == NULL)
624 return NULL;
625
626 Stringpool::Key version_key = 0;
627 if (version != NULL)
628 {
629 version = this->namepool_.find(version, &version_key);
630 if (version == NULL)
631 return NULL;
632 }
633
634 Symbol_table_key key(name_key, version_key);
635 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
636 if (p == this->table_.end())
637 return NULL;
638 return p->second;
639 }
640
641 // Resolve a Symbol with another Symbol. This is only used in the
642 // unusual case where there are references to both an unversioned
643 // symbol and a symbol with a version, and we then discover that that
644 // version is the default version. Because this is unusual, we do
645 // this the slow way, by converting back to an ELF symbol.
646
647 template<int size, bool big_endian>
648 void
649 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
650 {
651 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
652 elfcpp::Sym_write<size, big_endian> esym(buf);
653 // We don't bother to set the st_name or the st_shndx field.
654 esym.put_st_value(from->value());
655 esym.put_st_size(from->symsize());
656 esym.put_st_info(from->binding(), from->type());
657 esym.put_st_other(from->visibility(), from->nonvis());
658 bool is_ordinary;
659 unsigned int shndx = from->shndx(&is_ordinary);
660 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
661 from->version());
662 if (from->in_reg())
663 to->set_in_reg();
664 if (from->in_dyn())
665 to->set_in_dyn();
666 if (parameters->options().gc_sections())
667 this->gc_mark_dyn_syms(to);
668 }
669
670 // Record that a symbol is forced to be local by a version script or
671 // by visibility.
672
673 void
674 Symbol_table::force_local(Symbol* sym)
675 {
676 if (!sym->is_defined() && !sym->is_common())
677 return;
678 if (sym->is_forced_local())
679 {
680 // We already got this one.
681 return;
682 }
683 sym->set_is_forced_local();
684 this->forced_locals_.push_back(sym);
685 }
686
687 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
688 // is only called for undefined symbols, when at least one --wrap
689 // option was used.
690
691 const char*
692 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
693 {
694 // For some targets, we need to ignore a specific character when
695 // wrapping, and add it back later.
696 char prefix = '\0';
697 if (name[0] == parameters->target().wrap_char())
698 {
699 prefix = name[0];
700 ++name;
701 }
702
703 if (parameters->options().is_wrap(name))
704 {
705 // Turn NAME into __wrap_NAME.
706 std::string s;
707 if (prefix != '\0')
708 s += prefix;
709 s += "__wrap_";
710 s += name;
711
712 // This will give us both the old and new name in NAMEPOOL_, but
713 // that is OK. Only the versions we need will wind up in the
714 // real string table in the output file.
715 return this->namepool_.add(s.c_str(), true, name_key);
716 }
717
718 const char* const real_prefix = "__real_";
719 const size_t real_prefix_length = strlen(real_prefix);
720 if (strncmp(name, real_prefix, real_prefix_length) == 0
721 && parameters->options().is_wrap(name + real_prefix_length))
722 {
723 // Turn __real_NAME into NAME.
724 std::string s;
725 if (prefix != '\0')
726 s += prefix;
727 s += name + real_prefix_length;
728 return this->namepool_.add(s.c_str(), true, name_key);
729 }
730
731 return name;
732 }
733
734 // This is called when we see a symbol NAME/VERSION, and the symbol
735 // already exists in the symbol table, and VERSION is marked as being
736 // the default version. SYM is the NAME/VERSION symbol we just added.
737 // DEFAULT_IS_NEW is true if this is the first time we have seen the
738 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
739
740 template<int size, bool big_endian>
741 void
742 Symbol_table::define_default_version(Sized_symbol<size>* sym,
743 bool default_is_new,
744 Symbol_table_type::iterator pdef)
745 {
746 if (default_is_new)
747 {
748 // This is the first time we have seen NAME/NULL. Make
749 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
750 // version.
751 pdef->second = sym;
752 sym->set_is_default();
753 }
754 else if (pdef->second == sym)
755 {
756 // NAME/NULL already points to NAME/VERSION. Don't mark the
757 // symbol as the default if it is not already the default.
758 }
759 else
760 {
761 // This is the unfortunate case where we already have entries
762 // for both NAME/VERSION and NAME/NULL. We now see a symbol
763 // NAME/VERSION where VERSION is the default version. We have
764 // already resolved this new symbol with the existing
765 // NAME/VERSION symbol.
766
767 // It's possible that NAME/NULL and NAME/VERSION are both
768 // defined in regular objects. This can only happen if one
769 // object file defines foo and another defines foo@@ver. This
770 // is somewhat obscure, but we call it a multiple definition
771 // error.
772
773 // It's possible that NAME/NULL actually has a version, in which
774 // case it won't be the same as VERSION. This happens with
775 // ver_test_7.so in the testsuite for the symbol t2_2. We see
776 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
777 // then see an unadorned t2_2 in an object file and give it
778 // version VER1 from the version script. This looks like a
779 // default definition for VER1, so it looks like we should merge
780 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
781 // not obvious that this is an error, either. So we just punt.
782
783 // If one of the symbols has non-default visibility, and the
784 // other is defined in a shared object, then they are different
785 // symbols.
786
787 // Otherwise, we just resolve the symbols as though they were
788 // the same.
789
790 if (pdef->second->version() != NULL)
791 gold_assert(pdef->second->version() != sym->version());
792 else if (sym->visibility() != elfcpp::STV_DEFAULT
793 && pdef->second->is_from_dynobj())
794 ;
795 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
796 && sym->is_from_dynobj())
797 ;
798 else
799 {
800 const Sized_symbol<size>* symdef;
801 symdef = this->get_sized_symbol<size>(pdef->second);
802 Symbol_table::resolve<size, big_endian>(sym, symdef);
803 this->make_forwarder(pdef->second, sym);
804 pdef->second = sym;
805 sym->set_is_default();
806 }
807 }
808 }
809
810 // Add one symbol from OBJECT to the symbol table. NAME is symbol
811 // name and VERSION is the version; both are canonicalized. DEF is
812 // whether this is the default version. ST_SHNDX is the symbol's
813 // section index; IS_ORDINARY is whether this is a normal section
814 // rather than a special code.
815
816 // If DEF is true, then this is the definition of a default version of
817 // a symbol. That means that any lookup of NAME/NULL and any lookup
818 // of NAME/VERSION should always return the same symbol. This is
819 // obvious for references, but in particular we want to do this for
820 // definitions: overriding NAME/NULL should also override
821 // NAME/VERSION. If we don't do that, it would be very hard to
822 // override functions in a shared library which uses versioning.
823
824 // We implement this by simply making both entries in the hash table
825 // point to the same Symbol structure. That is easy enough if this is
826 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
827 // that we have seen both already, in which case they will both have
828 // independent entries in the symbol table. We can't simply change
829 // the symbol table entry, because we have pointers to the entries
830 // attached to the object files. So we mark the entry attached to the
831 // object file as a forwarder, and record it in the forwarders_ map.
832 // Note that entries in the hash table will never be marked as
833 // forwarders.
834 //
835 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
836 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
837 // for a special section code. ST_SHNDX may be modified if the symbol
838 // is defined in a section being discarded.
839
840 template<int size, bool big_endian>
841 Sized_symbol<size>*
842 Symbol_table::add_from_object(Object* object,
843 const char *name,
844 Stringpool::Key name_key,
845 const char *version,
846 Stringpool::Key version_key,
847 bool def,
848 const elfcpp::Sym<size, big_endian>& sym,
849 unsigned int st_shndx,
850 bool is_ordinary,
851 unsigned int orig_st_shndx)
852 {
853 // Print a message if this symbol is being traced.
854 if (parameters->options().is_trace_symbol(name))
855 {
856 if (orig_st_shndx == elfcpp::SHN_UNDEF)
857 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
858 else
859 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
860 }
861
862 // For an undefined symbol, we may need to adjust the name using
863 // --wrap.
864 if (orig_st_shndx == elfcpp::SHN_UNDEF
865 && parameters->options().any_wrap())
866 {
867 const char* wrap_name = this->wrap_symbol(name, &name_key);
868 if (wrap_name != name)
869 {
870 // If we see a reference to malloc with version GLIBC_2.0,
871 // and we turn it into a reference to __wrap_malloc, then we
872 // discard the version number. Otherwise the user would be
873 // required to specify the correct version for
874 // __wrap_malloc.
875 version = NULL;
876 version_key = 0;
877 name = wrap_name;
878 }
879 }
880
881 Symbol* const snull = NULL;
882 std::pair<typename Symbol_table_type::iterator, bool> ins =
883 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
884 snull));
885
886 std::pair<typename Symbol_table_type::iterator, bool> insdef =
887 std::make_pair(this->table_.end(), false);
888 if (def)
889 {
890 const Stringpool::Key vnull_key = 0;
891 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
892 vnull_key),
893 snull));
894 }
895
896 // ins.first: an iterator, which is a pointer to a pair.
897 // ins.first->first: the key (a pair of name and version).
898 // ins.first->second: the value (Symbol*).
899 // ins.second: true if new entry was inserted, false if not.
900
901 Sized_symbol<size>* ret;
902 bool was_undefined;
903 bool was_common;
904 if (!ins.second)
905 {
906 // We already have an entry for NAME/VERSION.
907 ret = this->get_sized_symbol<size>(ins.first->second);
908 gold_assert(ret != NULL);
909
910 was_undefined = ret->is_undefined();
911 was_common = ret->is_common();
912
913 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
914 version);
915 if (parameters->options().gc_sections())
916 this->gc_mark_dyn_syms(ret);
917
918 if (def)
919 this->define_default_version<size, big_endian>(ret, insdef.second,
920 insdef.first);
921 }
922 else
923 {
924 // This is the first time we have seen NAME/VERSION.
925 gold_assert(ins.first->second == NULL);
926
927 if (def && !insdef.second)
928 {
929 // We already have an entry for NAME/NULL. If we override
930 // it, then change it to NAME/VERSION.
931 ret = this->get_sized_symbol<size>(insdef.first->second);
932
933 was_undefined = ret->is_undefined();
934 was_common = ret->is_common();
935
936 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
937 version);
938 if (parameters->options().gc_sections())
939 this->gc_mark_dyn_syms(ret);
940 ins.first->second = ret;
941 }
942 else
943 {
944 was_undefined = false;
945 was_common = false;
946
947 Sized_target<size, big_endian>* target =
948 parameters->sized_target<size, big_endian>();
949 if (!target->has_make_symbol())
950 ret = new Sized_symbol<size>();
951 else
952 {
953 ret = target->make_symbol();
954 if (ret == NULL)
955 {
956 // This means that we don't want a symbol table
957 // entry after all.
958 if (!def)
959 this->table_.erase(ins.first);
960 else
961 {
962 this->table_.erase(insdef.first);
963 // Inserting insdef invalidated ins.
964 this->table_.erase(std::make_pair(name_key,
965 version_key));
966 }
967 return NULL;
968 }
969 }
970
971 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
972
973 ins.first->second = ret;
974 if (def)
975 {
976 // This is the first time we have seen NAME/NULL. Point
977 // it at the new entry for NAME/VERSION.
978 gold_assert(insdef.second);
979 insdef.first->second = ret;
980 }
981 }
982
983 if (def)
984 ret->set_is_default();
985 }
986
987 // Record every time we see a new undefined symbol, to speed up
988 // archive groups.
989 if (!was_undefined && ret->is_undefined())
990 ++this->saw_undefined_;
991
992 // Keep track of common symbols, to speed up common symbol
993 // allocation.
994 if (!was_common && ret->is_common())
995 {
996 if (ret->type() == elfcpp::STT_TLS)
997 this->tls_commons_.push_back(ret);
998 else if (!is_ordinary
999 && st_shndx == parameters->target().small_common_shndx())
1000 this->small_commons_.push_back(ret);
1001 else if (!is_ordinary
1002 && st_shndx == parameters->target().large_common_shndx())
1003 this->large_commons_.push_back(ret);
1004 else
1005 this->commons_.push_back(ret);
1006 }
1007
1008 // If we're not doing a relocatable link, then any symbol with
1009 // hidden or internal visibility is local.
1010 if ((ret->visibility() == elfcpp::STV_HIDDEN
1011 || ret->visibility() == elfcpp::STV_INTERNAL)
1012 && (ret->binding() == elfcpp::STB_GLOBAL
1013 || ret->binding() == elfcpp::STB_GNU_UNIQUE
1014 || ret->binding() == elfcpp::STB_WEAK)
1015 && !parameters->options().relocatable())
1016 this->force_local(ret);
1017
1018 return ret;
1019 }
1020
1021 // Add all the symbols in a relocatable object to the hash table.
1022
1023 template<int size, bool big_endian>
1024 void
1025 Symbol_table::add_from_relobj(
1026 Sized_relobj<size, big_endian>* relobj,
1027 const unsigned char* syms,
1028 size_t count,
1029 size_t symndx_offset,
1030 const char* sym_names,
1031 size_t sym_name_size,
1032 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1033 size_t *defined)
1034 {
1035 *defined = 0;
1036
1037 gold_assert(size == parameters->target().get_size());
1038
1039 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1040
1041 const bool just_symbols = relobj->just_symbols();
1042
1043 const unsigned char* p = syms;
1044 for (size_t i = 0; i < count; ++i, p += sym_size)
1045 {
1046 (*sympointers)[i] = NULL;
1047
1048 elfcpp::Sym<size, big_endian> sym(p);
1049
1050 unsigned int st_name = sym.get_st_name();
1051 if (st_name >= sym_name_size)
1052 {
1053 relobj->error(_("bad global symbol name offset %u at %zu"),
1054 st_name, i);
1055 continue;
1056 }
1057
1058 const char* name = sym_names + st_name;
1059
1060 bool is_ordinary;
1061 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1062 sym.get_st_shndx(),
1063 &is_ordinary);
1064 unsigned int orig_st_shndx = st_shndx;
1065 if (!is_ordinary)
1066 orig_st_shndx = elfcpp::SHN_UNDEF;
1067
1068 if (st_shndx != elfcpp::SHN_UNDEF)
1069 ++*defined;
1070
1071 // A symbol defined in a section which we are not including must
1072 // be treated as an undefined symbol.
1073 if (st_shndx != elfcpp::SHN_UNDEF
1074 && is_ordinary
1075 && !relobj->is_section_included(st_shndx))
1076 st_shndx = elfcpp::SHN_UNDEF;
1077
1078 // In an object file, an '@' in the name separates the symbol
1079 // name from the version name. If there are two '@' characters,
1080 // this is the default version.
1081 const char* ver = strchr(name, '@');
1082 Stringpool::Key ver_key = 0;
1083 int namelen = 0;
1084 // DEF: is the version default? LOCAL: is the symbol forced local?
1085 bool def = false;
1086 bool local = false;
1087
1088 if (ver != NULL)
1089 {
1090 // The symbol name is of the form foo@VERSION or foo@@VERSION
1091 namelen = ver - name;
1092 ++ver;
1093 if (*ver == '@')
1094 {
1095 def = true;
1096 ++ver;
1097 }
1098 ver = this->namepool_.add(ver, true, &ver_key);
1099 }
1100 // We don't want to assign a version to an undefined symbol,
1101 // even if it is listed in the version script. FIXME: What
1102 // about a common symbol?
1103 else
1104 {
1105 namelen = strlen(name);
1106 if (!this->version_script_.empty()
1107 && st_shndx != elfcpp::SHN_UNDEF)
1108 {
1109 // The symbol name did not have a version, but the
1110 // version script may assign a version anyway.
1111 std::string version;
1112 if (this->version_script_.get_symbol_version(name, &version))
1113 {
1114 // The version can be empty if the version script is
1115 // only used to force some symbols to be local.
1116 if (!version.empty())
1117 {
1118 ver = this->namepool_.add_with_length(version.c_str(),
1119 version.length(),
1120 true,
1121 &ver_key);
1122 def = true;
1123 }
1124 }
1125 else if (this->version_script_.symbol_is_local(name))
1126 local = true;
1127 }
1128 }
1129
1130 elfcpp::Sym<size, big_endian>* psym = &sym;
1131 unsigned char symbuf[sym_size];
1132 elfcpp::Sym<size, big_endian> sym2(symbuf);
1133 if (just_symbols)
1134 {
1135 memcpy(symbuf, p, sym_size);
1136 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1137 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1138 {
1139 // Symbol values in object files are section relative.
1140 // This is normally what we want, but since here we are
1141 // converting the symbol to absolute we need to add the
1142 // section address. The section address in an object
1143 // file is normally zero, but people can use a linker
1144 // script to change it.
1145 sw.put_st_value(sym.get_st_value()
1146 + relobj->section_address(orig_st_shndx));
1147 }
1148 st_shndx = elfcpp::SHN_ABS;
1149 is_ordinary = false;
1150 psym = &sym2;
1151 }
1152
1153 // Fix up visibility if object has no-export set.
1154 if (relobj->no_export())
1155 {
1156 // We may have copied symbol already above.
1157 if (psym != &sym2)
1158 {
1159 memcpy(symbuf, p, sym_size);
1160 psym = &sym2;
1161 }
1162
1163 elfcpp::STV visibility = sym2.get_st_visibility();
1164 if (visibility == elfcpp::STV_DEFAULT
1165 || visibility == elfcpp::STV_PROTECTED)
1166 {
1167 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1168 unsigned char nonvis = sym2.get_st_nonvis();
1169 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1170 }
1171 }
1172
1173 Stringpool::Key name_key;
1174 name = this->namepool_.add_with_length(name, namelen, true,
1175 &name_key);
1176
1177 Sized_symbol<size>* res;
1178 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1179 def, *psym, st_shndx, is_ordinary,
1180 orig_st_shndx);
1181
1182 // If building a shared library using garbage collection, do not
1183 // treat externally visible symbols as garbage.
1184 if (parameters->options().gc_sections()
1185 && parameters->options().shared())
1186 this->gc_mark_symbol_for_shlib(res);
1187
1188 if (local)
1189 this->force_local(res);
1190
1191 (*sympointers)[i] = res;
1192 }
1193 }
1194
1195 // Add a symbol from a plugin-claimed file.
1196
1197 template<int size, bool big_endian>
1198 Symbol*
1199 Symbol_table::add_from_pluginobj(
1200 Sized_pluginobj<size, big_endian>* obj,
1201 const char* name,
1202 const char* ver,
1203 elfcpp::Sym<size, big_endian>* sym)
1204 {
1205 unsigned int st_shndx = sym->get_st_shndx();
1206 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1207
1208 Stringpool::Key ver_key = 0;
1209 bool def = false;
1210 bool local = false;
1211
1212 if (ver != NULL)
1213 {
1214 ver = this->namepool_.add(ver, true, &ver_key);
1215 }
1216 // We don't want to assign a version to an undefined symbol,
1217 // even if it is listed in the version script. FIXME: What
1218 // about a common symbol?
1219 else
1220 {
1221 if (!this->version_script_.empty()
1222 && st_shndx != elfcpp::SHN_UNDEF)
1223 {
1224 // The symbol name did not have a version, but the
1225 // version script may assign a version anyway.
1226 std::string version;
1227 if (this->version_script_.get_symbol_version(name, &version))
1228 {
1229 // The version can be empty if the version script is
1230 // only used to force some symbols to be local.
1231 if (!version.empty())
1232 {
1233 ver = this->namepool_.add_with_length(version.c_str(),
1234 version.length(),
1235 true,
1236 &ver_key);
1237 def = true;
1238 }
1239 }
1240 else if (this->version_script_.symbol_is_local(name))
1241 local = true;
1242 }
1243 }
1244
1245 Stringpool::Key name_key;
1246 name = this->namepool_.add(name, true, &name_key);
1247
1248 Sized_symbol<size>* res;
1249 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1250 def, *sym, st_shndx, is_ordinary, st_shndx);
1251
1252 if (local)
1253 this->force_local(res);
1254
1255 return res;
1256 }
1257
1258 // Add all the symbols in a dynamic object to the hash table.
1259
1260 template<int size, bool big_endian>
1261 void
1262 Symbol_table::add_from_dynobj(
1263 Sized_dynobj<size, big_endian>* dynobj,
1264 const unsigned char* syms,
1265 size_t count,
1266 const char* sym_names,
1267 size_t sym_name_size,
1268 const unsigned char* versym,
1269 size_t versym_size,
1270 const std::vector<const char*>* version_map,
1271 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1272 size_t* defined)
1273 {
1274 *defined = 0;
1275
1276 gold_assert(size == parameters->target().get_size());
1277
1278 if (dynobj->just_symbols())
1279 {
1280 gold_error(_("--just-symbols does not make sense with a shared object"));
1281 return;
1282 }
1283
1284 if (versym != NULL && versym_size / 2 < count)
1285 {
1286 dynobj->error(_("too few symbol versions"));
1287 return;
1288 }
1289
1290 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1291
1292 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1293 // weak aliases. This is necessary because if the dynamic object
1294 // provides the same variable under two names, one of which is a
1295 // weak definition, and the regular object refers to the weak
1296 // definition, we have to put both the weak definition and the
1297 // strong definition into the dynamic symbol table. Given a weak
1298 // definition, the only way that we can find the corresponding
1299 // strong definition, if any, is to search the symbol table.
1300 std::vector<Sized_symbol<size>*> object_symbols;
1301
1302 const unsigned char* p = syms;
1303 const unsigned char* vs = versym;
1304 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1305 {
1306 elfcpp::Sym<size, big_endian> sym(p);
1307
1308 if (sympointers != NULL)
1309 (*sympointers)[i] = NULL;
1310
1311 // Ignore symbols with local binding or that have
1312 // internal or hidden visibility.
1313 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1314 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1315 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1316 continue;
1317
1318 // A protected symbol in a shared library must be treated as a
1319 // normal symbol when viewed from outside the shared library.
1320 // Implement this by overriding the visibility here.
1321 elfcpp::Sym<size, big_endian>* psym = &sym;
1322 unsigned char symbuf[sym_size];
1323 elfcpp::Sym<size, big_endian> sym2(symbuf);
1324 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1325 {
1326 memcpy(symbuf, p, sym_size);
1327 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1328 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1329 psym = &sym2;
1330 }
1331
1332 unsigned int st_name = psym->get_st_name();
1333 if (st_name >= sym_name_size)
1334 {
1335 dynobj->error(_("bad symbol name offset %u at %zu"),
1336 st_name, i);
1337 continue;
1338 }
1339
1340 const char* name = sym_names + st_name;
1341
1342 bool is_ordinary;
1343 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1344 &is_ordinary);
1345
1346 if (st_shndx != elfcpp::SHN_UNDEF)
1347 ++*defined;
1348
1349 Sized_symbol<size>* res;
1350
1351 if (versym == NULL)
1352 {
1353 Stringpool::Key name_key;
1354 name = this->namepool_.add(name, true, &name_key);
1355 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1356 false, *psym, st_shndx, is_ordinary,
1357 st_shndx);
1358 }
1359 else
1360 {
1361 // Read the version information.
1362
1363 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1364
1365 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1366 v &= elfcpp::VERSYM_VERSION;
1367
1368 // The Sun documentation says that V can be VER_NDX_LOCAL,
1369 // or VER_NDX_GLOBAL, or a version index. The meaning of
1370 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1371 // The old GNU linker will happily generate VER_NDX_LOCAL
1372 // for an undefined symbol. I don't know what the Sun
1373 // linker will generate.
1374
1375 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1376 && st_shndx != elfcpp::SHN_UNDEF)
1377 {
1378 // This symbol should not be visible outside the object.
1379 continue;
1380 }
1381
1382 // At this point we are definitely going to add this symbol.
1383 Stringpool::Key name_key;
1384 name = this->namepool_.add(name, true, &name_key);
1385
1386 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1387 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1388 {
1389 // This symbol does not have a version.
1390 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1391 false, *psym, st_shndx, is_ordinary,
1392 st_shndx);
1393 }
1394 else
1395 {
1396 if (v >= version_map->size())
1397 {
1398 dynobj->error(_("versym for symbol %zu out of range: %u"),
1399 i, v);
1400 continue;
1401 }
1402
1403 const char* version = (*version_map)[v];
1404 if (version == NULL)
1405 {
1406 dynobj->error(_("versym for symbol %zu has no name: %u"),
1407 i, v);
1408 continue;
1409 }
1410
1411 Stringpool::Key version_key;
1412 version = this->namepool_.add(version, true, &version_key);
1413
1414 // If this is an absolute symbol, and the version name
1415 // and symbol name are the same, then this is the
1416 // version definition symbol. These symbols exist to
1417 // support using -u to pull in particular versions. We
1418 // do not want to record a version for them.
1419 if (st_shndx == elfcpp::SHN_ABS
1420 && !is_ordinary
1421 && name_key == version_key)
1422 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1423 false, *psym, st_shndx, is_ordinary,
1424 st_shndx);
1425 else
1426 {
1427 const bool def = (!hidden
1428 && st_shndx != elfcpp::SHN_UNDEF);
1429 res = this->add_from_object(dynobj, name, name_key, version,
1430 version_key, def, *psym, st_shndx,
1431 is_ordinary, st_shndx);
1432 }
1433 }
1434 }
1435
1436 // Note that it is possible that RES was overridden by an
1437 // earlier object, in which case it can't be aliased here.
1438 if (st_shndx != elfcpp::SHN_UNDEF
1439 && is_ordinary
1440 && psym->get_st_type() == elfcpp::STT_OBJECT
1441 && res->source() == Symbol::FROM_OBJECT
1442 && res->object() == dynobj)
1443 object_symbols.push_back(res);
1444
1445 if (sympointers != NULL)
1446 (*sympointers)[i] = res;
1447 }
1448
1449 this->record_weak_aliases(&object_symbols);
1450 }
1451
1452 // This is used to sort weak aliases. We sort them first by section
1453 // index, then by offset, then by weak ahead of strong.
1454
1455 template<int size>
1456 class Weak_alias_sorter
1457 {
1458 public:
1459 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1460 };
1461
1462 template<int size>
1463 bool
1464 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1465 const Sized_symbol<size>* s2) const
1466 {
1467 bool is_ordinary;
1468 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1469 gold_assert(is_ordinary);
1470 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1471 gold_assert(is_ordinary);
1472 if (s1_shndx != s2_shndx)
1473 return s1_shndx < s2_shndx;
1474
1475 if (s1->value() != s2->value())
1476 return s1->value() < s2->value();
1477 if (s1->binding() != s2->binding())
1478 {
1479 if (s1->binding() == elfcpp::STB_WEAK)
1480 return true;
1481 if (s2->binding() == elfcpp::STB_WEAK)
1482 return false;
1483 }
1484 return std::string(s1->name()) < std::string(s2->name());
1485 }
1486
1487 // SYMBOLS is a list of object symbols from a dynamic object. Look
1488 // for any weak aliases, and record them so that if we add the weak
1489 // alias to the dynamic symbol table, we also add the corresponding
1490 // strong symbol.
1491
1492 template<int size>
1493 void
1494 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1495 {
1496 // Sort the vector by section index, then by offset, then by weak
1497 // ahead of strong.
1498 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1499
1500 // Walk through the vector. For each weak definition, record
1501 // aliases.
1502 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1503 symbols->begin();
1504 p != symbols->end();
1505 ++p)
1506 {
1507 if ((*p)->binding() != elfcpp::STB_WEAK)
1508 continue;
1509
1510 // Build a circular list of weak aliases. Each symbol points to
1511 // the next one in the circular list.
1512
1513 Sized_symbol<size>* from_sym = *p;
1514 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1515 for (q = p + 1; q != symbols->end(); ++q)
1516 {
1517 bool dummy;
1518 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1519 || (*q)->value() != from_sym->value())
1520 break;
1521
1522 this->weak_aliases_[from_sym] = *q;
1523 from_sym->set_has_alias();
1524 from_sym = *q;
1525 }
1526
1527 if (from_sym != *p)
1528 {
1529 this->weak_aliases_[from_sym] = *p;
1530 from_sym->set_has_alias();
1531 }
1532
1533 p = q - 1;
1534 }
1535 }
1536
1537 // Create and return a specially defined symbol. If ONLY_IF_REF is
1538 // true, then only create the symbol if there is a reference to it.
1539 // If this does not return NULL, it sets *POLDSYM to the existing
1540 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1541 // resolve the newly created symbol to the old one. This
1542 // canonicalizes *PNAME and *PVERSION.
1543
1544 template<int size, bool big_endian>
1545 Sized_symbol<size>*
1546 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1547 bool only_if_ref,
1548 Sized_symbol<size>** poldsym,
1549 bool *resolve_oldsym)
1550 {
1551 *resolve_oldsym = false;
1552
1553 // If the caller didn't give us a version, see if we get one from
1554 // the version script.
1555 std::string v;
1556 bool is_default_version = false;
1557 if (*pversion == NULL)
1558 {
1559 if (this->version_script_.get_symbol_version(*pname, &v))
1560 {
1561 if (!v.empty())
1562 *pversion = v.c_str();
1563
1564 // If we get the version from a version script, then we are
1565 // also the default version.
1566 is_default_version = true;
1567 }
1568 }
1569
1570 Symbol* oldsym;
1571 Sized_symbol<size>* sym;
1572
1573 bool add_to_table = false;
1574 typename Symbol_table_type::iterator add_loc = this->table_.end();
1575 bool add_def_to_table = false;
1576 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1577
1578 if (only_if_ref)
1579 {
1580 oldsym = this->lookup(*pname, *pversion);
1581 if (oldsym == NULL && is_default_version)
1582 oldsym = this->lookup(*pname, NULL);
1583 if (oldsym == NULL || !oldsym->is_undefined())
1584 return NULL;
1585
1586 *pname = oldsym->name();
1587 if (!is_default_version)
1588 *pversion = oldsym->version();
1589 }
1590 else
1591 {
1592 // Canonicalize NAME and VERSION.
1593 Stringpool::Key name_key;
1594 *pname = this->namepool_.add(*pname, true, &name_key);
1595
1596 Stringpool::Key version_key = 0;
1597 if (*pversion != NULL)
1598 *pversion = this->namepool_.add(*pversion, true, &version_key);
1599
1600 Symbol* const snull = NULL;
1601 std::pair<typename Symbol_table_type::iterator, bool> ins =
1602 this->table_.insert(std::make_pair(std::make_pair(name_key,
1603 version_key),
1604 snull));
1605
1606 std::pair<typename Symbol_table_type::iterator, bool> insdef =
1607 std::make_pair(this->table_.end(), false);
1608 if (is_default_version)
1609 {
1610 const Stringpool::Key vnull = 0;
1611 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
1612 vnull),
1613 snull));
1614 }
1615
1616 if (!ins.second)
1617 {
1618 // We already have a symbol table entry for NAME/VERSION.
1619 oldsym = ins.first->second;
1620 gold_assert(oldsym != NULL);
1621
1622 if (is_default_version)
1623 {
1624 Sized_symbol<size>* soldsym =
1625 this->get_sized_symbol<size>(oldsym);
1626 this->define_default_version<size, big_endian>(soldsym,
1627 insdef.second,
1628 insdef.first);
1629 }
1630 }
1631 else
1632 {
1633 // We haven't seen this symbol before.
1634 gold_assert(ins.first->second == NULL);
1635
1636 add_to_table = true;
1637 add_loc = ins.first;
1638
1639 if (is_default_version && !insdef.second)
1640 {
1641 // We are adding NAME/VERSION, and it is the default
1642 // version. We already have an entry for NAME/NULL.
1643 oldsym = insdef.first->second;
1644 *resolve_oldsym = true;
1645 }
1646 else
1647 {
1648 oldsym = NULL;
1649
1650 if (is_default_version)
1651 {
1652 add_def_to_table = true;
1653 add_def_loc = insdef.first;
1654 }
1655 }
1656 }
1657 }
1658
1659 const Target& target = parameters->target();
1660 if (!target.has_make_symbol())
1661 sym = new Sized_symbol<size>();
1662 else
1663 {
1664 Sized_target<size, big_endian>* sized_target =
1665 parameters->sized_target<size, big_endian>();
1666 sym = sized_target->make_symbol();
1667 if (sym == NULL)
1668 return NULL;
1669 }
1670
1671 if (add_to_table)
1672 add_loc->second = sym;
1673 else
1674 gold_assert(oldsym != NULL);
1675
1676 if (add_def_to_table)
1677 add_def_loc->second = sym;
1678
1679 *poldsym = this->get_sized_symbol<size>(oldsym);
1680
1681 return sym;
1682 }
1683
1684 // Define a symbol based on an Output_data.
1685
1686 Symbol*
1687 Symbol_table::define_in_output_data(const char* name,
1688 const char* version,
1689 Defined defined,
1690 Output_data* od,
1691 uint64_t value,
1692 uint64_t symsize,
1693 elfcpp::STT type,
1694 elfcpp::STB binding,
1695 elfcpp::STV visibility,
1696 unsigned char nonvis,
1697 bool offset_is_from_end,
1698 bool only_if_ref)
1699 {
1700 if (parameters->target().get_size() == 32)
1701 {
1702 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1703 return this->do_define_in_output_data<32>(name, version, defined, od,
1704 value, symsize, type, binding,
1705 visibility, nonvis,
1706 offset_is_from_end,
1707 only_if_ref);
1708 #else
1709 gold_unreachable();
1710 #endif
1711 }
1712 else if (parameters->target().get_size() == 64)
1713 {
1714 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1715 return this->do_define_in_output_data<64>(name, version, defined, od,
1716 value, symsize, type, binding,
1717 visibility, nonvis,
1718 offset_is_from_end,
1719 only_if_ref);
1720 #else
1721 gold_unreachable();
1722 #endif
1723 }
1724 else
1725 gold_unreachable();
1726 }
1727
1728 // Define a symbol in an Output_data, sized version.
1729
1730 template<int size>
1731 Sized_symbol<size>*
1732 Symbol_table::do_define_in_output_data(
1733 const char* name,
1734 const char* version,
1735 Defined defined,
1736 Output_data* od,
1737 typename elfcpp::Elf_types<size>::Elf_Addr value,
1738 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1739 elfcpp::STT type,
1740 elfcpp::STB binding,
1741 elfcpp::STV visibility,
1742 unsigned char nonvis,
1743 bool offset_is_from_end,
1744 bool only_if_ref)
1745 {
1746 Sized_symbol<size>* sym;
1747 Sized_symbol<size>* oldsym;
1748 bool resolve_oldsym;
1749
1750 if (parameters->target().is_big_endian())
1751 {
1752 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1753 sym = this->define_special_symbol<size, true>(&name, &version,
1754 only_if_ref, &oldsym,
1755 &resolve_oldsym);
1756 #else
1757 gold_unreachable();
1758 #endif
1759 }
1760 else
1761 {
1762 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1763 sym = this->define_special_symbol<size, false>(&name, &version,
1764 only_if_ref, &oldsym,
1765 &resolve_oldsym);
1766 #else
1767 gold_unreachable();
1768 #endif
1769 }
1770
1771 if (sym == NULL)
1772 return NULL;
1773
1774 sym->init_output_data(name, version, od, value, symsize, type, binding,
1775 visibility, nonvis, offset_is_from_end);
1776
1777 if (oldsym == NULL)
1778 {
1779 if (binding == elfcpp::STB_LOCAL
1780 || this->version_script_.symbol_is_local(name))
1781 this->force_local(sym);
1782 else if (version != NULL)
1783 sym->set_is_default();
1784 return sym;
1785 }
1786
1787 if (Symbol_table::should_override_with_special(oldsym, defined))
1788 this->override_with_special(oldsym, sym);
1789
1790 if (resolve_oldsym)
1791 return sym;
1792 else
1793 {
1794 delete sym;
1795 return oldsym;
1796 }
1797 }
1798
1799 // Define a symbol based on an Output_segment.
1800
1801 Symbol*
1802 Symbol_table::define_in_output_segment(const char* name,
1803 const char* version,
1804 Defined defined,
1805 Output_segment* os,
1806 uint64_t value,
1807 uint64_t symsize,
1808 elfcpp::STT type,
1809 elfcpp::STB binding,
1810 elfcpp::STV visibility,
1811 unsigned char nonvis,
1812 Symbol::Segment_offset_base offset_base,
1813 bool only_if_ref)
1814 {
1815 if (parameters->target().get_size() == 32)
1816 {
1817 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1818 return this->do_define_in_output_segment<32>(name, version, defined, os,
1819 value, symsize, type,
1820 binding, visibility, nonvis,
1821 offset_base, only_if_ref);
1822 #else
1823 gold_unreachable();
1824 #endif
1825 }
1826 else if (parameters->target().get_size() == 64)
1827 {
1828 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1829 return this->do_define_in_output_segment<64>(name, version, defined, os,
1830 value, symsize, type,
1831 binding, visibility, nonvis,
1832 offset_base, only_if_ref);
1833 #else
1834 gold_unreachable();
1835 #endif
1836 }
1837 else
1838 gold_unreachable();
1839 }
1840
1841 // Define a symbol in an Output_segment, sized version.
1842
1843 template<int size>
1844 Sized_symbol<size>*
1845 Symbol_table::do_define_in_output_segment(
1846 const char* name,
1847 const char* version,
1848 Defined defined,
1849 Output_segment* os,
1850 typename elfcpp::Elf_types<size>::Elf_Addr value,
1851 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1852 elfcpp::STT type,
1853 elfcpp::STB binding,
1854 elfcpp::STV visibility,
1855 unsigned char nonvis,
1856 Symbol::Segment_offset_base offset_base,
1857 bool only_if_ref)
1858 {
1859 Sized_symbol<size>* sym;
1860 Sized_symbol<size>* oldsym;
1861 bool resolve_oldsym;
1862
1863 if (parameters->target().is_big_endian())
1864 {
1865 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1866 sym = this->define_special_symbol<size, true>(&name, &version,
1867 only_if_ref, &oldsym,
1868 &resolve_oldsym);
1869 #else
1870 gold_unreachable();
1871 #endif
1872 }
1873 else
1874 {
1875 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1876 sym = this->define_special_symbol<size, false>(&name, &version,
1877 only_if_ref, &oldsym,
1878 &resolve_oldsym);
1879 #else
1880 gold_unreachable();
1881 #endif
1882 }
1883
1884 if (sym == NULL)
1885 return NULL;
1886
1887 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1888 visibility, nonvis, offset_base);
1889
1890 if (oldsym == NULL)
1891 {
1892 if (binding == elfcpp::STB_LOCAL
1893 || this->version_script_.symbol_is_local(name))
1894 this->force_local(sym);
1895 else if (version != NULL)
1896 sym->set_is_default();
1897 return sym;
1898 }
1899
1900 if (Symbol_table::should_override_with_special(oldsym, defined))
1901 this->override_with_special(oldsym, sym);
1902
1903 if (resolve_oldsym)
1904 return sym;
1905 else
1906 {
1907 delete sym;
1908 return oldsym;
1909 }
1910 }
1911
1912 // Define a special symbol with a constant value. It is a multiple
1913 // definition error if this symbol is already defined.
1914
1915 Symbol*
1916 Symbol_table::define_as_constant(const char* name,
1917 const char* version,
1918 Defined defined,
1919 uint64_t value,
1920 uint64_t symsize,
1921 elfcpp::STT type,
1922 elfcpp::STB binding,
1923 elfcpp::STV visibility,
1924 unsigned char nonvis,
1925 bool only_if_ref,
1926 bool force_override)
1927 {
1928 if (parameters->target().get_size() == 32)
1929 {
1930 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1931 return this->do_define_as_constant<32>(name, version, defined, value,
1932 symsize, type, binding,
1933 visibility, nonvis, only_if_ref,
1934 force_override);
1935 #else
1936 gold_unreachable();
1937 #endif
1938 }
1939 else if (parameters->target().get_size() == 64)
1940 {
1941 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1942 return this->do_define_as_constant<64>(name, version, defined, value,
1943 symsize, type, binding,
1944 visibility, nonvis, only_if_ref,
1945 force_override);
1946 #else
1947 gold_unreachable();
1948 #endif
1949 }
1950 else
1951 gold_unreachable();
1952 }
1953
1954 // Define a symbol as a constant, sized version.
1955
1956 template<int size>
1957 Sized_symbol<size>*
1958 Symbol_table::do_define_as_constant(
1959 const char* name,
1960 const char* version,
1961 Defined defined,
1962 typename elfcpp::Elf_types<size>::Elf_Addr value,
1963 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1964 elfcpp::STT type,
1965 elfcpp::STB binding,
1966 elfcpp::STV visibility,
1967 unsigned char nonvis,
1968 bool only_if_ref,
1969 bool force_override)
1970 {
1971 Sized_symbol<size>* sym;
1972 Sized_symbol<size>* oldsym;
1973 bool resolve_oldsym;
1974
1975 if (parameters->target().is_big_endian())
1976 {
1977 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1978 sym = this->define_special_symbol<size, true>(&name, &version,
1979 only_if_ref, &oldsym,
1980 &resolve_oldsym);
1981 #else
1982 gold_unreachable();
1983 #endif
1984 }
1985 else
1986 {
1987 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1988 sym = this->define_special_symbol<size, false>(&name, &version,
1989 only_if_ref, &oldsym,
1990 &resolve_oldsym);
1991 #else
1992 gold_unreachable();
1993 #endif
1994 }
1995
1996 if (sym == NULL)
1997 return NULL;
1998
1999 sym->init_constant(name, version, value, symsize, type, binding, visibility,
2000 nonvis);
2001
2002 if (oldsym == NULL)
2003 {
2004 // Version symbols are absolute symbols with name == version.
2005 // We don't want to force them to be local.
2006 if ((version == NULL
2007 || name != version
2008 || value != 0)
2009 && (binding == elfcpp::STB_LOCAL
2010 || this->version_script_.symbol_is_local(name)))
2011 this->force_local(sym);
2012 else if (version != NULL
2013 && (name != version || value != 0))
2014 sym->set_is_default();
2015 return sym;
2016 }
2017
2018 if (force_override
2019 || Symbol_table::should_override_with_special(oldsym, defined))
2020 this->override_with_special(oldsym, sym);
2021
2022 if (resolve_oldsym)
2023 return sym;
2024 else
2025 {
2026 delete sym;
2027 return oldsym;
2028 }
2029 }
2030
2031 // Define a set of symbols in output sections.
2032
2033 void
2034 Symbol_table::define_symbols(const Layout* layout, int count,
2035 const Define_symbol_in_section* p,
2036 bool only_if_ref)
2037 {
2038 for (int i = 0; i < count; ++i, ++p)
2039 {
2040 Output_section* os = layout->find_output_section(p->output_section);
2041 if (os != NULL)
2042 this->define_in_output_data(p->name, NULL, PREDEFINED, os, p->value,
2043 p->size, p->type, p->binding,
2044 p->visibility, p->nonvis,
2045 p->offset_is_from_end,
2046 only_if_ref || p->only_if_ref);
2047 else
2048 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2049 p->type, p->binding, p->visibility, p->nonvis,
2050 only_if_ref || p->only_if_ref,
2051 false);
2052 }
2053 }
2054
2055 // Define a set of symbols in output segments.
2056
2057 void
2058 Symbol_table::define_symbols(const Layout* layout, int count,
2059 const Define_symbol_in_segment* p,
2060 bool only_if_ref)
2061 {
2062 for (int i = 0; i < count; ++i, ++p)
2063 {
2064 Output_segment* os = layout->find_output_segment(p->segment_type,
2065 p->segment_flags_set,
2066 p->segment_flags_clear);
2067 if (os != NULL)
2068 this->define_in_output_segment(p->name, NULL, PREDEFINED, os, p->value,
2069 p->size, p->type, p->binding,
2070 p->visibility, p->nonvis,
2071 p->offset_base,
2072 only_if_ref || p->only_if_ref);
2073 else
2074 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2075 p->type, p->binding, p->visibility, p->nonvis,
2076 only_if_ref || p->only_if_ref,
2077 false);
2078 }
2079 }
2080
2081 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2082 // symbol should be defined--typically a .dyn.bss section. VALUE is
2083 // the offset within POSD.
2084
2085 template<int size>
2086 void
2087 Symbol_table::define_with_copy_reloc(
2088 Sized_symbol<size>* csym,
2089 Output_data* posd,
2090 typename elfcpp::Elf_types<size>::Elf_Addr value)
2091 {
2092 gold_assert(csym->is_from_dynobj());
2093 gold_assert(!csym->is_copied_from_dynobj());
2094 Object* object = csym->object();
2095 gold_assert(object->is_dynamic());
2096 Dynobj* dynobj = static_cast<Dynobj*>(object);
2097
2098 // Our copied variable has to override any variable in a shared
2099 // library.
2100 elfcpp::STB binding = csym->binding();
2101 if (binding == elfcpp::STB_WEAK)
2102 binding = elfcpp::STB_GLOBAL;
2103
2104 this->define_in_output_data(csym->name(), csym->version(), COPY,
2105 posd, value, csym->symsize(),
2106 csym->type(), binding,
2107 csym->visibility(), csym->nonvis(),
2108 false, false);
2109
2110 csym->set_is_copied_from_dynobj();
2111 csym->set_needs_dynsym_entry();
2112
2113 this->copied_symbol_dynobjs_[csym] = dynobj;
2114
2115 // We have now defined all aliases, but we have not entered them all
2116 // in the copied_symbol_dynobjs_ map.
2117 if (csym->has_alias())
2118 {
2119 Symbol* sym = csym;
2120 while (true)
2121 {
2122 sym = this->weak_aliases_[sym];
2123 if (sym == csym)
2124 break;
2125 gold_assert(sym->output_data() == posd);
2126
2127 sym->set_is_copied_from_dynobj();
2128 this->copied_symbol_dynobjs_[sym] = dynobj;
2129 }
2130 }
2131 }
2132
2133 // SYM is defined using a COPY reloc. Return the dynamic object where
2134 // the original definition was found.
2135
2136 Dynobj*
2137 Symbol_table::get_copy_source(const Symbol* sym) const
2138 {
2139 gold_assert(sym->is_copied_from_dynobj());
2140 Copied_symbol_dynobjs::const_iterator p =
2141 this->copied_symbol_dynobjs_.find(sym);
2142 gold_assert(p != this->copied_symbol_dynobjs_.end());
2143 return p->second;
2144 }
2145
2146 // Add any undefined symbols named on the command line.
2147
2148 void
2149 Symbol_table::add_undefined_symbols_from_command_line()
2150 {
2151 if (parameters->options().any_undefined())
2152 {
2153 if (parameters->target().get_size() == 32)
2154 {
2155 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2156 this->do_add_undefined_symbols_from_command_line<32>();
2157 #else
2158 gold_unreachable();
2159 #endif
2160 }
2161 else if (parameters->target().get_size() == 64)
2162 {
2163 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2164 this->do_add_undefined_symbols_from_command_line<64>();
2165 #else
2166 gold_unreachable();
2167 #endif
2168 }
2169 else
2170 gold_unreachable();
2171 }
2172 }
2173
2174 template<int size>
2175 void
2176 Symbol_table::do_add_undefined_symbols_from_command_line()
2177 {
2178 for (options::String_set::const_iterator p =
2179 parameters->options().undefined_begin();
2180 p != parameters->options().undefined_end();
2181 ++p)
2182 {
2183 const char* name = p->c_str();
2184
2185 if (this->lookup(name) != NULL)
2186 continue;
2187
2188 const char* version = NULL;
2189
2190 Sized_symbol<size>* sym;
2191 Sized_symbol<size>* oldsym;
2192 bool resolve_oldsym;
2193 if (parameters->target().is_big_endian())
2194 {
2195 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2196 sym = this->define_special_symbol<size, true>(&name, &version,
2197 false, &oldsym,
2198 &resolve_oldsym);
2199 #else
2200 gold_unreachable();
2201 #endif
2202 }
2203 else
2204 {
2205 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2206 sym = this->define_special_symbol<size, false>(&name, &version,
2207 false, &oldsym,
2208 &resolve_oldsym);
2209 #else
2210 gold_unreachable();
2211 #endif
2212 }
2213
2214 gold_assert(oldsym == NULL);
2215
2216 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2217 elfcpp::STV_DEFAULT, 0);
2218 ++this->saw_undefined_;
2219 }
2220 }
2221
2222 // Set the dynamic symbol indexes. INDEX is the index of the first
2223 // global dynamic symbol. Pointers to the symbols are stored into the
2224 // vector SYMS. The names are added to DYNPOOL. This returns an
2225 // updated dynamic symbol index.
2226
2227 unsigned int
2228 Symbol_table::set_dynsym_indexes(unsigned int index,
2229 std::vector<Symbol*>* syms,
2230 Stringpool* dynpool,
2231 Versions* versions)
2232 {
2233 for (Symbol_table_type::iterator p = this->table_.begin();
2234 p != this->table_.end();
2235 ++p)
2236 {
2237 Symbol* sym = p->second;
2238
2239 // Note that SYM may already have a dynamic symbol index, since
2240 // some symbols appear more than once in the symbol table, with
2241 // and without a version.
2242
2243 if (!sym->should_add_dynsym_entry())
2244 sym->set_dynsym_index(-1U);
2245 else if (!sym->has_dynsym_index())
2246 {
2247 sym->set_dynsym_index(index);
2248 ++index;
2249 syms->push_back(sym);
2250 dynpool->add(sym->name(), false, NULL);
2251
2252 // Record any version information.
2253 if (sym->version() != NULL)
2254 versions->record_version(this, dynpool, sym);
2255
2256 // If the symbol is defined in a dynamic object and is
2257 // referenced in a regular object, then mark the dynamic
2258 // object as needed. This is used to implement --as-needed.
2259 if (sym->is_from_dynobj() && sym->in_reg())
2260 sym->object()->set_is_needed();
2261 }
2262 }
2263
2264 // Finish up the versions. In some cases this may add new dynamic
2265 // symbols.
2266 index = versions->finalize(this, index, syms);
2267
2268 return index;
2269 }
2270
2271 // Set the final values for all the symbols. The index of the first
2272 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2273 // file offset OFF. Add their names to POOL. Return the new file
2274 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2275
2276 off_t
2277 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2278 size_t dyncount, Stringpool* pool,
2279 unsigned int *plocal_symcount)
2280 {
2281 off_t ret;
2282
2283 gold_assert(*plocal_symcount != 0);
2284 this->first_global_index_ = *plocal_symcount;
2285
2286 this->dynamic_offset_ = dynoff;
2287 this->first_dynamic_global_index_ = dyn_global_index;
2288 this->dynamic_count_ = dyncount;
2289
2290 if (parameters->target().get_size() == 32)
2291 {
2292 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2293 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2294 #else
2295 gold_unreachable();
2296 #endif
2297 }
2298 else if (parameters->target().get_size() == 64)
2299 {
2300 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2301 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2302 #else
2303 gold_unreachable();
2304 #endif
2305 }
2306 else
2307 gold_unreachable();
2308
2309 // Now that we have the final symbol table, we can reliably note
2310 // which symbols should get warnings.
2311 this->warnings_.note_warnings(this);
2312
2313 return ret;
2314 }
2315
2316 // SYM is going into the symbol table at *PINDEX. Add the name to
2317 // POOL, update *PINDEX and *POFF.
2318
2319 template<int size>
2320 void
2321 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2322 unsigned int* pindex, off_t* poff)
2323 {
2324 sym->set_symtab_index(*pindex);
2325 pool->add(sym->name(), false, NULL);
2326 ++*pindex;
2327 *poff += elfcpp::Elf_sizes<size>::sym_size;
2328 }
2329
2330 // Set the final value for all the symbols. This is called after
2331 // Layout::finalize, so all the output sections have their final
2332 // address.
2333
2334 template<int size>
2335 off_t
2336 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2337 unsigned int* plocal_symcount)
2338 {
2339 off = align_address(off, size >> 3);
2340 this->offset_ = off;
2341
2342 unsigned int index = *plocal_symcount;
2343 const unsigned int orig_index = index;
2344
2345 // First do all the symbols which have been forced to be local, as
2346 // they must appear before all global symbols.
2347 for (Forced_locals::iterator p = this->forced_locals_.begin();
2348 p != this->forced_locals_.end();
2349 ++p)
2350 {
2351 Symbol* sym = *p;
2352 gold_assert(sym->is_forced_local());
2353 if (this->sized_finalize_symbol<size>(sym))
2354 {
2355 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2356 ++*plocal_symcount;
2357 }
2358 }
2359
2360 // Now do all the remaining symbols.
2361 for (Symbol_table_type::iterator p = this->table_.begin();
2362 p != this->table_.end();
2363 ++p)
2364 {
2365 Symbol* sym = p->second;
2366 if (this->sized_finalize_symbol<size>(sym))
2367 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2368 }
2369
2370 this->output_count_ = index - orig_index;
2371
2372 return off;
2373 }
2374
2375 // Compute the final value of SYM and store status in location PSTATUS.
2376 // During relaxation, this may be called multiple times for a symbol to
2377 // compute its would-be final value in each relaxation pass.
2378
2379 template<int size>
2380 typename Sized_symbol<size>::Value_type
2381 Symbol_table::compute_final_value(
2382 const Sized_symbol<size>* sym,
2383 Compute_final_value_status* pstatus) const
2384 {
2385 typedef typename Sized_symbol<size>::Value_type Value_type;
2386 Value_type value;
2387
2388 switch (sym->source())
2389 {
2390 case Symbol::FROM_OBJECT:
2391 {
2392 bool is_ordinary;
2393 unsigned int shndx = sym->shndx(&is_ordinary);
2394
2395 if (!is_ordinary
2396 && shndx != elfcpp::SHN_ABS
2397 && !Symbol::is_common_shndx(shndx))
2398 {
2399 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2400 return 0;
2401 }
2402
2403 Object* symobj = sym->object();
2404 if (symobj->is_dynamic())
2405 {
2406 value = 0;
2407 shndx = elfcpp::SHN_UNDEF;
2408 }
2409 else if (symobj->pluginobj() != NULL)
2410 {
2411 value = 0;
2412 shndx = elfcpp::SHN_UNDEF;
2413 }
2414 else if (shndx == elfcpp::SHN_UNDEF)
2415 value = 0;
2416 else if (!is_ordinary
2417 && (shndx == elfcpp::SHN_ABS
2418 || Symbol::is_common_shndx(shndx)))
2419 value = sym->value();
2420 else
2421 {
2422 Relobj* relobj = static_cast<Relobj*>(symobj);
2423 Output_section* os = relobj->output_section(shndx);
2424
2425 if (this->is_section_folded(relobj, shndx))
2426 {
2427 gold_assert(os == NULL);
2428 // Get the os of the section it is folded onto.
2429 Section_id folded = this->icf_->get_folded_section(relobj,
2430 shndx);
2431 gold_assert(folded.first != NULL);
2432 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2433 unsigned folded_shndx = folded.second;
2434
2435 os = folded_obj->output_section(folded_shndx);
2436 gold_assert(os != NULL);
2437
2438 // Replace (relobj, shndx) with canonical ICF input section.
2439 shndx = folded_shndx;
2440 relobj = folded_obj;
2441 }
2442
2443 uint64_t secoff64 = relobj->output_section_offset(shndx);
2444 if (os == NULL)
2445 {
2446 bool static_or_reloc = (parameters->doing_static_link() ||
2447 parameters->options().relocatable());
2448 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2449
2450 *pstatus = CFVS_NO_OUTPUT_SECTION;
2451 return 0;
2452 }
2453
2454 if (secoff64 == -1ULL)
2455 {
2456 // The section needs special handling (e.g., a merge section).
2457
2458 value = os->output_address(relobj, shndx, sym->value());
2459 }
2460 else
2461 {
2462 Value_type secoff =
2463 convert_types<Value_type, uint64_t>(secoff64);
2464 if (sym->type() == elfcpp::STT_TLS)
2465 value = sym->value() + os->tls_offset() + secoff;
2466 else
2467 value = sym->value() + os->address() + secoff;
2468 }
2469 }
2470 }
2471 break;
2472
2473 case Symbol::IN_OUTPUT_DATA:
2474 {
2475 Output_data* od = sym->output_data();
2476 value = sym->value();
2477 if (sym->type() != elfcpp::STT_TLS)
2478 value += od->address();
2479 else
2480 {
2481 Output_section* os = od->output_section();
2482 gold_assert(os != NULL);
2483 value += os->tls_offset() + (od->address() - os->address());
2484 }
2485 if (sym->offset_is_from_end())
2486 value += od->data_size();
2487 }
2488 break;
2489
2490 case Symbol::IN_OUTPUT_SEGMENT:
2491 {
2492 Output_segment* os = sym->output_segment();
2493 value = sym->value();
2494 if (sym->type() != elfcpp::STT_TLS)
2495 value += os->vaddr();
2496 switch (sym->offset_base())
2497 {
2498 case Symbol::SEGMENT_START:
2499 break;
2500 case Symbol::SEGMENT_END:
2501 value += os->memsz();
2502 break;
2503 case Symbol::SEGMENT_BSS:
2504 value += os->filesz();
2505 break;
2506 default:
2507 gold_unreachable();
2508 }
2509 }
2510 break;
2511
2512 case Symbol::IS_CONSTANT:
2513 value = sym->value();
2514 break;
2515
2516 case Symbol::IS_UNDEFINED:
2517 value = 0;
2518 break;
2519
2520 default:
2521 gold_unreachable();
2522 }
2523
2524 *pstatus = CFVS_OK;
2525 return value;
2526 }
2527
2528 // Finalize the symbol SYM. This returns true if the symbol should be
2529 // added to the symbol table, false otherwise.
2530
2531 template<int size>
2532 bool
2533 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2534 {
2535 typedef typename Sized_symbol<size>::Value_type Value_type;
2536
2537 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2538
2539 // The default version of a symbol may appear twice in the symbol
2540 // table. We only need to finalize it once.
2541 if (sym->has_symtab_index())
2542 return false;
2543
2544 if (!sym->in_reg())
2545 {
2546 gold_assert(!sym->has_symtab_index());
2547 sym->set_symtab_index(-1U);
2548 gold_assert(sym->dynsym_index() == -1U);
2549 return false;
2550 }
2551
2552 // Compute final symbol value.
2553 Compute_final_value_status status;
2554 Value_type value = this->compute_final_value(sym, &status);
2555
2556 switch (status)
2557 {
2558 case CFVS_OK:
2559 break;
2560 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2561 {
2562 bool is_ordinary;
2563 unsigned int shndx = sym->shndx(&is_ordinary);
2564 gold_error(_("%s: unsupported symbol section 0x%x"),
2565 sym->demangled_name().c_str(), shndx);
2566 }
2567 break;
2568 case CFVS_NO_OUTPUT_SECTION:
2569 sym->set_symtab_index(-1U);
2570 return false;
2571 default:
2572 gold_unreachable();
2573 }
2574
2575 sym->set_value(value);
2576
2577 if (parameters->options().strip_all()
2578 || !parameters->options().should_retain_symbol(sym->name()))
2579 {
2580 sym->set_symtab_index(-1U);
2581 return false;
2582 }
2583
2584 return true;
2585 }
2586
2587 // Write out the global symbols.
2588
2589 void
2590 Symbol_table::write_globals(const Stringpool* sympool,
2591 const Stringpool* dynpool,
2592 Output_symtab_xindex* symtab_xindex,
2593 Output_symtab_xindex* dynsym_xindex,
2594 Output_file* of) const
2595 {
2596 switch (parameters->size_and_endianness())
2597 {
2598 #ifdef HAVE_TARGET_32_LITTLE
2599 case Parameters::TARGET_32_LITTLE:
2600 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2601 dynsym_xindex, of);
2602 break;
2603 #endif
2604 #ifdef HAVE_TARGET_32_BIG
2605 case Parameters::TARGET_32_BIG:
2606 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2607 dynsym_xindex, of);
2608 break;
2609 #endif
2610 #ifdef HAVE_TARGET_64_LITTLE
2611 case Parameters::TARGET_64_LITTLE:
2612 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2613 dynsym_xindex, of);
2614 break;
2615 #endif
2616 #ifdef HAVE_TARGET_64_BIG
2617 case Parameters::TARGET_64_BIG:
2618 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2619 dynsym_xindex, of);
2620 break;
2621 #endif
2622 default:
2623 gold_unreachable();
2624 }
2625 }
2626
2627 // Write out the global symbols.
2628
2629 template<int size, bool big_endian>
2630 void
2631 Symbol_table::sized_write_globals(const Stringpool* sympool,
2632 const Stringpool* dynpool,
2633 Output_symtab_xindex* symtab_xindex,
2634 Output_symtab_xindex* dynsym_xindex,
2635 Output_file* of) const
2636 {
2637 const Target& target = parameters->target();
2638
2639 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2640
2641 const unsigned int output_count = this->output_count_;
2642 const section_size_type oview_size = output_count * sym_size;
2643 const unsigned int first_global_index = this->first_global_index_;
2644 unsigned char* psyms;
2645 if (this->offset_ == 0 || output_count == 0)
2646 psyms = NULL;
2647 else
2648 psyms = of->get_output_view(this->offset_, oview_size);
2649
2650 const unsigned int dynamic_count = this->dynamic_count_;
2651 const section_size_type dynamic_size = dynamic_count * sym_size;
2652 const unsigned int first_dynamic_global_index =
2653 this->first_dynamic_global_index_;
2654 unsigned char* dynamic_view;
2655 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2656 dynamic_view = NULL;
2657 else
2658 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2659
2660 for (Symbol_table_type::const_iterator p = this->table_.begin();
2661 p != this->table_.end();
2662 ++p)
2663 {
2664 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2665
2666 // Possibly warn about unresolved symbols in shared libraries.
2667 this->warn_about_undefined_dynobj_symbol(sym);
2668
2669 unsigned int sym_index = sym->symtab_index();
2670 unsigned int dynsym_index;
2671 if (dynamic_view == NULL)
2672 dynsym_index = -1U;
2673 else
2674 dynsym_index = sym->dynsym_index();
2675
2676 if (sym_index == -1U && dynsym_index == -1U)
2677 {
2678 // This symbol is not included in the output file.
2679 continue;
2680 }
2681
2682 unsigned int shndx;
2683 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2684 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2685 switch (sym->source())
2686 {
2687 case Symbol::FROM_OBJECT:
2688 {
2689 bool is_ordinary;
2690 unsigned int in_shndx = sym->shndx(&is_ordinary);
2691
2692 if (!is_ordinary
2693 && in_shndx != elfcpp::SHN_ABS
2694 && !Symbol::is_common_shndx(in_shndx))
2695 {
2696 gold_error(_("%s: unsupported symbol section 0x%x"),
2697 sym->demangled_name().c_str(), in_shndx);
2698 shndx = in_shndx;
2699 }
2700 else
2701 {
2702 Object* symobj = sym->object();
2703 if (symobj->is_dynamic())
2704 {
2705 if (sym->needs_dynsym_value())
2706 dynsym_value = target.dynsym_value(sym);
2707 shndx = elfcpp::SHN_UNDEF;
2708 }
2709 else if (symobj->pluginobj() != NULL)
2710 shndx = elfcpp::SHN_UNDEF;
2711 else if (in_shndx == elfcpp::SHN_UNDEF
2712 || (!is_ordinary
2713 && (in_shndx == elfcpp::SHN_ABS
2714 || Symbol::is_common_shndx(in_shndx))))
2715 shndx = in_shndx;
2716 else
2717 {
2718 Relobj* relobj = static_cast<Relobj*>(symobj);
2719 Output_section* os = relobj->output_section(in_shndx);
2720 if (this->is_section_folded(relobj, in_shndx))
2721 {
2722 // This global symbol must be written out even though
2723 // it is folded.
2724 // Get the os of the section it is folded onto.
2725 Section_id folded =
2726 this->icf_->get_folded_section(relobj, in_shndx);
2727 gold_assert(folded.first !=NULL);
2728 Relobj* folded_obj =
2729 reinterpret_cast<Relobj*>(folded.first);
2730 os = folded_obj->output_section(folded.second);
2731 gold_assert(os != NULL);
2732 }
2733 gold_assert(os != NULL);
2734 shndx = os->out_shndx();
2735
2736 if (shndx >= elfcpp::SHN_LORESERVE)
2737 {
2738 if (sym_index != -1U)
2739 symtab_xindex->add(sym_index, shndx);
2740 if (dynsym_index != -1U)
2741 dynsym_xindex->add(dynsym_index, shndx);
2742 shndx = elfcpp::SHN_XINDEX;
2743 }
2744
2745 // In object files symbol values are section
2746 // relative.
2747 if (parameters->options().relocatable())
2748 sym_value -= os->address();
2749 }
2750 }
2751 }
2752 break;
2753
2754 case Symbol::IN_OUTPUT_DATA:
2755 shndx = sym->output_data()->out_shndx();
2756 if (shndx >= elfcpp::SHN_LORESERVE)
2757 {
2758 if (sym_index != -1U)
2759 symtab_xindex->add(sym_index, shndx);
2760 if (dynsym_index != -1U)
2761 dynsym_xindex->add(dynsym_index, shndx);
2762 shndx = elfcpp::SHN_XINDEX;
2763 }
2764 break;
2765
2766 case Symbol::IN_OUTPUT_SEGMENT:
2767 shndx = elfcpp::SHN_ABS;
2768 break;
2769
2770 case Symbol::IS_CONSTANT:
2771 shndx = elfcpp::SHN_ABS;
2772 break;
2773
2774 case Symbol::IS_UNDEFINED:
2775 shndx = elfcpp::SHN_UNDEF;
2776 break;
2777
2778 default:
2779 gold_unreachable();
2780 }
2781
2782 if (sym_index != -1U)
2783 {
2784 sym_index -= first_global_index;
2785 gold_assert(sym_index < output_count);
2786 unsigned char* ps = psyms + (sym_index * sym_size);
2787 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2788 sympool, ps);
2789 }
2790
2791 if (dynsym_index != -1U)
2792 {
2793 dynsym_index -= first_dynamic_global_index;
2794 gold_assert(dynsym_index < dynamic_count);
2795 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2796 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2797 dynpool, pd);
2798 }
2799 }
2800
2801 of->write_output_view(this->offset_, oview_size, psyms);
2802 if (dynamic_view != NULL)
2803 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2804 }
2805
2806 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2807 // strtab holding the name.
2808
2809 template<int size, bool big_endian>
2810 void
2811 Symbol_table::sized_write_symbol(
2812 Sized_symbol<size>* sym,
2813 typename elfcpp::Elf_types<size>::Elf_Addr value,
2814 unsigned int shndx,
2815 const Stringpool* pool,
2816 unsigned char* p) const
2817 {
2818 elfcpp::Sym_write<size, big_endian> osym(p);
2819 osym.put_st_name(pool->get_offset(sym->name()));
2820 osym.put_st_value(value);
2821 // Use a symbol size of zero for undefined symbols from shared libraries.
2822 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2823 osym.put_st_size(0);
2824 else
2825 osym.put_st_size(sym->symsize());
2826 elfcpp::STT type = sym->type();
2827 // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2828 if (type == elfcpp::STT_GNU_IFUNC
2829 && sym->is_from_dynobj())
2830 type = elfcpp::STT_FUNC;
2831 // A version script may have overridden the default binding.
2832 if (sym->is_forced_local())
2833 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2834 else
2835 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), type));
2836 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2837 osym.put_st_shndx(shndx);
2838 }
2839
2840 // Check for unresolved symbols in shared libraries. This is
2841 // controlled by the --allow-shlib-undefined option.
2842
2843 // We only warn about libraries for which we have seen all the
2844 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2845 // which were not seen in this link. If we didn't see a DT_NEEDED
2846 // entry, we aren't going to be able to reliably report whether the
2847 // symbol is undefined.
2848
2849 // We also don't warn about libraries found in a system library
2850 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2851 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2852 // can have undefined references satisfied by ld-linux.so.
2853
2854 inline void
2855 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2856 {
2857 bool dummy;
2858 if (sym->source() == Symbol::FROM_OBJECT
2859 && sym->object()->is_dynamic()
2860 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2861 && sym->binding() != elfcpp::STB_WEAK
2862 && !parameters->options().allow_shlib_undefined()
2863 && !parameters->target().is_defined_by_abi(sym)
2864 && !sym->object()->is_in_system_directory())
2865 {
2866 // A very ugly cast.
2867 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2868 if (!dynobj->has_unknown_needed_entries())
2869 gold_undefined_symbol(sym);
2870 }
2871 }
2872
2873 // Write out a section symbol. Return the update offset.
2874
2875 void
2876 Symbol_table::write_section_symbol(const Output_section *os,
2877 Output_symtab_xindex* symtab_xindex,
2878 Output_file* of,
2879 off_t offset) const
2880 {
2881 switch (parameters->size_and_endianness())
2882 {
2883 #ifdef HAVE_TARGET_32_LITTLE
2884 case Parameters::TARGET_32_LITTLE:
2885 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2886 offset);
2887 break;
2888 #endif
2889 #ifdef HAVE_TARGET_32_BIG
2890 case Parameters::TARGET_32_BIG:
2891 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2892 offset);
2893 break;
2894 #endif
2895 #ifdef HAVE_TARGET_64_LITTLE
2896 case Parameters::TARGET_64_LITTLE:
2897 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2898 offset);
2899 break;
2900 #endif
2901 #ifdef HAVE_TARGET_64_BIG
2902 case Parameters::TARGET_64_BIG:
2903 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2904 offset);
2905 break;
2906 #endif
2907 default:
2908 gold_unreachable();
2909 }
2910 }
2911
2912 // Write out a section symbol, specialized for size and endianness.
2913
2914 template<int size, bool big_endian>
2915 void
2916 Symbol_table::sized_write_section_symbol(const Output_section* os,
2917 Output_symtab_xindex* symtab_xindex,
2918 Output_file* of,
2919 off_t offset) const
2920 {
2921 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2922
2923 unsigned char* pov = of->get_output_view(offset, sym_size);
2924
2925 elfcpp::Sym_write<size, big_endian> osym(pov);
2926 osym.put_st_name(0);
2927 if (parameters->options().relocatable())
2928 osym.put_st_value(0);
2929 else
2930 osym.put_st_value(os->address());
2931 osym.put_st_size(0);
2932 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2933 elfcpp::STT_SECTION));
2934 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2935
2936 unsigned int shndx = os->out_shndx();
2937 if (shndx >= elfcpp::SHN_LORESERVE)
2938 {
2939 symtab_xindex->add(os->symtab_index(), shndx);
2940 shndx = elfcpp::SHN_XINDEX;
2941 }
2942 osym.put_st_shndx(shndx);
2943
2944 of->write_output_view(offset, sym_size, pov);
2945 }
2946
2947 // Print statistical information to stderr. This is used for --stats.
2948
2949 void
2950 Symbol_table::print_stats() const
2951 {
2952 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2953 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2954 program_name, this->table_.size(), this->table_.bucket_count());
2955 #else
2956 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2957 program_name, this->table_.size());
2958 #endif
2959 this->namepool_.print_stats("symbol table stringpool");
2960 }
2961
2962 // We check for ODR violations by looking for symbols with the same
2963 // name for which the debugging information reports that they were
2964 // defined in different source locations. When comparing the source
2965 // location, we consider instances with the same base filename and
2966 // line number to be the same. This is because different object
2967 // files/shared libraries can include the same header file using
2968 // different paths, and we don't want to report an ODR violation in
2969 // that case.
2970
2971 // This struct is used to compare line information, as returned by
2972 // Dwarf_line_info::one_addr2line. It implements a < comparison
2973 // operator used with std::set.
2974
2975 struct Odr_violation_compare
2976 {
2977 bool
2978 operator()(const std::string& s1, const std::string& s2) const
2979 {
2980 std::string::size_type pos1 = s1.rfind('/');
2981 std::string::size_type pos2 = s2.rfind('/');
2982 if (pos1 == std::string::npos
2983 || pos2 == std::string::npos)
2984 return s1 < s2;
2985 return s1.compare(pos1, std::string::npos,
2986 s2, pos2, std::string::npos) < 0;
2987 }
2988 };
2989
2990 // Check candidate_odr_violations_ to find symbols with the same name
2991 // but apparently different definitions (different source-file/line-no).
2992
2993 void
2994 Symbol_table::detect_odr_violations(const Task* task,
2995 const char* output_file_name) const
2996 {
2997 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2998 it != candidate_odr_violations_.end();
2999 ++it)
3000 {
3001 const char* symbol_name = it->first;
3002 // We use a sorted set so the output is deterministic.
3003 std::set<std::string, Odr_violation_compare> line_nums;
3004
3005 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3006 locs = it->second.begin();
3007 locs != it->second.end();
3008 ++locs)
3009 {
3010 // We need to lock the object in order to read it. This
3011 // means that we have to run in a singleton Task. If we
3012 // want to run this in a general Task for better
3013 // performance, we will need one Task for object, plus
3014 // appropriate locking to ensure that we don't conflict with
3015 // other uses of the object. Also note, one_addr2line is not
3016 // currently thread-safe.
3017 Task_lock_obj<Object> tl(task, locs->object);
3018 // 16 is the size of the object-cache that one_addr2line should use.
3019 std::string lineno = Dwarf_line_info::one_addr2line(
3020 locs->object, locs->shndx, locs->offset, 16);
3021 if (!lineno.empty())
3022 line_nums.insert(lineno);
3023 }
3024
3025 if (line_nums.size() > 1)
3026 {
3027 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3028 "places (possible ODR violation):"),
3029 output_file_name, demangle(symbol_name).c_str());
3030 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
3031 it2 != line_nums.end();
3032 ++it2)
3033 fprintf(stderr, " %s\n", it2->c_str());
3034 }
3035 }
3036 // We only call one_addr2line() in this function, so we can clear its cache.
3037 Dwarf_line_info::clear_addr2line_cache();
3038 }
3039
3040 // Warnings functions.
3041
3042 // Add a new warning.
3043
3044 void
3045 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3046 const std::string& warning)
3047 {
3048 name = symtab->canonicalize_name(name);
3049 this->warnings_[name].set(obj, warning);
3050 }
3051
3052 // Look through the warnings and mark the symbols for which we should
3053 // warn. This is called during Layout::finalize when we know the
3054 // sources for all the symbols.
3055
3056 void
3057 Warnings::note_warnings(Symbol_table* symtab)
3058 {
3059 for (Warning_table::iterator p = this->warnings_.begin();
3060 p != this->warnings_.end();
3061 ++p)
3062 {
3063 Symbol* sym = symtab->lookup(p->first, NULL);
3064 if (sym != NULL
3065 && sym->source() == Symbol::FROM_OBJECT
3066 && sym->object() == p->second.object)
3067 sym->set_has_warning();
3068 }
3069 }
3070
3071 // Issue a warning. This is called when we see a relocation against a
3072 // symbol for which has a warning.
3073
3074 template<int size, bool big_endian>
3075 void
3076 Warnings::issue_warning(const Symbol* sym,
3077 const Relocate_info<size, big_endian>* relinfo,
3078 size_t relnum, off_t reloffset) const
3079 {
3080 gold_assert(sym->has_warning());
3081 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3082 gold_assert(p != this->warnings_.end());
3083 gold_warning_at_location(relinfo, relnum, reloffset,
3084 "%s", p->second.text.c_str());
3085 }
3086
3087 // Instantiate the templates we need. We could use the configure
3088 // script to restrict this to only the ones needed for implemented
3089 // targets.
3090
3091 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3092 template
3093 void
3094 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3095 #endif
3096
3097 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3098 template
3099 void
3100 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3101 #endif
3102
3103 #ifdef HAVE_TARGET_32_LITTLE
3104 template
3105 void
3106 Symbol_table::add_from_relobj<32, false>(
3107 Sized_relobj<32, false>* relobj,
3108 const unsigned char* syms,
3109 size_t count,
3110 size_t symndx_offset,
3111 const char* sym_names,
3112 size_t sym_name_size,
3113 Sized_relobj<32, false>::Symbols* sympointers,
3114 size_t* defined);
3115 #endif
3116
3117 #ifdef HAVE_TARGET_32_BIG
3118 template
3119 void
3120 Symbol_table::add_from_relobj<32, true>(
3121 Sized_relobj<32, true>* relobj,
3122 const unsigned char* syms,
3123 size_t count,
3124 size_t symndx_offset,
3125 const char* sym_names,
3126 size_t sym_name_size,
3127 Sized_relobj<32, true>::Symbols* sympointers,
3128 size_t* defined);
3129 #endif
3130
3131 #ifdef HAVE_TARGET_64_LITTLE
3132 template
3133 void
3134 Symbol_table::add_from_relobj<64, false>(
3135 Sized_relobj<64, false>* relobj,
3136 const unsigned char* syms,
3137 size_t count,
3138 size_t symndx_offset,
3139 const char* sym_names,
3140 size_t sym_name_size,
3141 Sized_relobj<64, false>::Symbols* sympointers,
3142 size_t* defined);
3143 #endif
3144
3145 #ifdef HAVE_TARGET_64_BIG
3146 template
3147 void
3148 Symbol_table::add_from_relobj<64, true>(
3149 Sized_relobj<64, true>* relobj,
3150 const unsigned char* syms,
3151 size_t count,
3152 size_t symndx_offset,
3153 const char* sym_names,
3154 size_t sym_name_size,
3155 Sized_relobj<64, true>::Symbols* sympointers,
3156 size_t* defined);
3157 #endif
3158
3159 #ifdef HAVE_TARGET_32_LITTLE
3160 template
3161 Symbol*
3162 Symbol_table::add_from_pluginobj<32, false>(
3163 Sized_pluginobj<32, false>* obj,
3164 const char* name,
3165 const char* ver,
3166 elfcpp::Sym<32, false>* sym);
3167 #endif
3168
3169 #ifdef HAVE_TARGET_32_BIG
3170 template
3171 Symbol*
3172 Symbol_table::add_from_pluginobj<32, true>(
3173 Sized_pluginobj<32, true>* obj,
3174 const char* name,
3175 const char* ver,
3176 elfcpp::Sym<32, true>* sym);
3177 #endif
3178
3179 #ifdef HAVE_TARGET_64_LITTLE
3180 template
3181 Symbol*
3182 Symbol_table::add_from_pluginobj<64, false>(
3183 Sized_pluginobj<64, false>* obj,
3184 const char* name,
3185 const char* ver,
3186 elfcpp::Sym<64, false>* sym);
3187 #endif
3188
3189 #ifdef HAVE_TARGET_64_BIG
3190 template
3191 Symbol*
3192 Symbol_table::add_from_pluginobj<64, true>(
3193 Sized_pluginobj<64, true>* obj,
3194 const char* name,
3195 const char* ver,
3196 elfcpp::Sym<64, true>* sym);
3197 #endif
3198
3199 #ifdef HAVE_TARGET_32_LITTLE
3200 template
3201 void
3202 Symbol_table::add_from_dynobj<32, false>(
3203 Sized_dynobj<32, false>* dynobj,
3204 const unsigned char* syms,
3205 size_t count,
3206 const char* sym_names,
3207 size_t sym_name_size,
3208 const unsigned char* versym,
3209 size_t versym_size,
3210 const std::vector<const char*>* version_map,
3211 Sized_relobj<32, false>::Symbols* sympointers,
3212 size_t* defined);
3213 #endif
3214
3215 #ifdef HAVE_TARGET_32_BIG
3216 template
3217 void
3218 Symbol_table::add_from_dynobj<32, true>(
3219 Sized_dynobj<32, true>* dynobj,
3220 const unsigned char* syms,
3221 size_t count,
3222 const char* sym_names,
3223 size_t sym_name_size,
3224 const unsigned char* versym,
3225 size_t versym_size,
3226 const std::vector<const char*>* version_map,
3227 Sized_relobj<32, true>::Symbols* sympointers,
3228 size_t* defined);
3229 #endif
3230
3231 #ifdef HAVE_TARGET_64_LITTLE
3232 template
3233 void
3234 Symbol_table::add_from_dynobj<64, false>(
3235 Sized_dynobj<64, false>* dynobj,
3236 const unsigned char* syms,
3237 size_t count,
3238 const char* sym_names,
3239 size_t sym_name_size,
3240 const unsigned char* versym,
3241 size_t versym_size,
3242 const std::vector<const char*>* version_map,
3243 Sized_relobj<64, false>::Symbols* sympointers,
3244 size_t* defined);
3245 #endif
3246
3247 #ifdef HAVE_TARGET_64_BIG
3248 template
3249 void
3250 Symbol_table::add_from_dynobj<64, true>(
3251 Sized_dynobj<64, true>* dynobj,
3252 const unsigned char* syms,
3253 size_t count,
3254 const char* sym_names,
3255 size_t sym_name_size,
3256 const unsigned char* versym,
3257 size_t versym_size,
3258 const std::vector<const char*>* version_map,
3259 Sized_relobj<64, true>::Symbols* sympointers,
3260 size_t* defined);
3261 #endif
3262
3263 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3264 template
3265 void
3266 Symbol_table::define_with_copy_reloc<32>(
3267 Sized_symbol<32>* sym,
3268 Output_data* posd,
3269 elfcpp::Elf_types<32>::Elf_Addr value);
3270 #endif
3271
3272 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3273 template
3274 void
3275 Symbol_table::define_with_copy_reloc<64>(
3276 Sized_symbol<64>* sym,
3277 Output_data* posd,
3278 elfcpp::Elf_types<64>::Elf_Addr value);
3279 #endif
3280
3281 #ifdef HAVE_TARGET_32_LITTLE
3282 template
3283 void
3284 Warnings::issue_warning<32, false>(const Symbol* sym,
3285 const Relocate_info<32, false>* relinfo,
3286 size_t relnum, off_t reloffset) const;
3287 #endif
3288
3289 #ifdef HAVE_TARGET_32_BIG
3290 template
3291 void
3292 Warnings::issue_warning<32, true>(const Symbol* sym,
3293 const Relocate_info<32, true>* relinfo,
3294 size_t relnum, off_t reloffset) const;
3295 #endif
3296
3297 #ifdef HAVE_TARGET_64_LITTLE
3298 template
3299 void
3300 Warnings::issue_warning<64, false>(const Symbol* sym,
3301 const Relocate_info<64, false>* relinfo,
3302 size_t relnum, off_t reloffset) const;
3303 #endif
3304
3305 #ifdef HAVE_TARGET_64_BIG
3306 template
3307 void
3308 Warnings::issue_warning<64, true>(const Symbol* sym,
3309 const Relocate_info<64, true>* relinfo,
3310 size_t relnum, off_t reloffset) const;
3311 #endif
3312
3313 } // End namespace gold.
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