Add support for -pie.
[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_WEAK)
1014 && !parameters->options().relocatable())
1015 this->force_local(ret);
1016
1017 return ret;
1018 }
1019
1020 // Add all the symbols in a relocatable object to the hash table.
1021
1022 template<int size, bool big_endian>
1023 void
1024 Symbol_table::add_from_relobj(
1025 Sized_relobj<size, big_endian>* relobj,
1026 const unsigned char* syms,
1027 size_t count,
1028 size_t symndx_offset,
1029 const char* sym_names,
1030 size_t sym_name_size,
1031 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1032 size_t *defined)
1033 {
1034 *defined = 0;
1035
1036 gold_assert(size == parameters->target().get_size());
1037
1038 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1039
1040 const bool just_symbols = relobj->just_symbols();
1041
1042 const unsigned char* p = syms;
1043 for (size_t i = 0; i < count; ++i, p += sym_size)
1044 {
1045 (*sympointers)[i] = NULL;
1046
1047 elfcpp::Sym<size, big_endian> sym(p);
1048
1049 unsigned int st_name = sym.get_st_name();
1050 if (st_name >= sym_name_size)
1051 {
1052 relobj->error(_("bad global symbol name offset %u at %zu"),
1053 st_name, i);
1054 continue;
1055 }
1056
1057 const char* name = sym_names + st_name;
1058
1059 bool is_ordinary;
1060 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1061 sym.get_st_shndx(),
1062 &is_ordinary);
1063 unsigned int orig_st_shndx = st_shndx;
1064 if (!is_ordinary)
1065 orig_st_shndx = elfcpp::SHN_UNDEF;
1066
1067 if (st_shndx != elfcpp::SHN_UNDEF)
1068 ++*defined;
1069
1070 // A symbol defined in a section which we are not including must
1071 // be treated as an undefined symbol.
1072 if (st_shndx != elfcpp::SHN_UNDEF
1073 && is_ordinary
1074 && !relobj->is_section_included(st_shndx))
1075 st_shndx = elfcpp::SHN_UNDEF;
1076
1077 // In an object file, an '@' in the name separates the symbol
1078 // name from the version name. If there are two '@' characters,
1079 // this is the default version.
1080 const char* ver = strchr(name, '@');
1081 Stringpool::Key ver_key = 0;
1082 int namelen = 0;
1083 // DEF: is the version default? LOCAL: is the symbol forced local?
1084 bool def = false;
1085 bool local = false;
1086
1087 if (ver != NULL)
1088 {
1089 // The symbol name is of the form foo@VERSION or foo@@VERSION
1090 namelen = ver - name;
1091 ++ver;
1092 if (*ver == '@')
1093 {
1094 def = true;
1095 ++ver;
1096 }
1097 ver = this->namepool_.add(ver, true, &ver_key);
1098 }
1099 // We don't want to assign a version to an undefined symbol,
1100 // even if it is listed in the version script. FIXME: What
1101 // about a common symbol?
1102 else
1103 {
1104 namelen = strlen(name);
1105 if (!this->version_script_.empty()
1106 && st_shndx != elfcpp::SHN_UNDEF)
1107 {
1108 // The symbol name did not have a version, but the
1109 // version script may assign a version anyway.
1110 std::string version;
1111 if (this->version_script_.get_symbol_version(name, &version))
1112 {
1113 // The version can be empty if the version script is
1114 // only used to force some symbols to be local.
1115 if (!version.empty())
1116 {
1117 ver = this->namepool_.add_with_length(version.c_str(),
1118 version.length(),
1119 true,
1120 &ver_key);
1121 def = true;
1122 }
1123 }
1124 else if (this->version_script_.symbol_is_local(name))
1125 local = true;
1126 }
1127 }
1128
1129 elfcpp::Sym<size, big_endian>* psym = &sym;
1130 unsigned char symbuf[sym_size];
1131 elfcpp::Sym<size, big_endian> sym2(symbuf);
1132 if (just_symbols)
1133 {
1134 memcpy(symbuf, p, sym_size);
1135 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1136 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1137 {
1138 // Symbol values in object files are section relative.
1139 // This is normally what we want, but since here we are
1140 // converting the symbol to absolute we need to add the
1141 // section address. The section address in an object
1142 // file is normally zero, but people can use a linker
1143 // script to change it.
1144 sw.put_st_value(sym.get_st_value()
1145 + relobj->section_address(orig_st_shndx));
1146 }
1147 st_shndx = elfcpp::SHN_ABS;
1148 is_ordinary = false;
1149 psym = &sym2;
1150 }
1151
1152 // Fix up visibility if object has no-export set.
1153 if (relobj->no_export())
1154 {
1155 // We may have copied symbol already above.
1156 if (psym != &sym2)
1157 {
1158 memcpy(symbuf, p, sym_size);
1159 psym = &sym2;
1160 }
1161
1162 elfcpp::STV visibility = sym2.get_st_visibility();
1163 if (visibility == elfcpp::STV_DEFAULT
1164 || visibility == elfcpp::STV_PROTECTED)
1165 {
1166 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1167 unsigned char nonvis = sym2.get_st_nonvis();
1168 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1169 }
1170 }
1171
1172 Stringpool::Key name_key;
1173 name = this->namepool_.add_with_length(name, namelen, true,
1174 &name_key);
1175
1176 Sized_symbol<size>* res;
1177 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1178 def, *psym, st_shndx, is_ordinary,
1179 orig_st_shndx);
1180
1181 // If building a shared library using garbage collection, do not
1182 // treat externally visible symbols as garbage.
1183 if (parameters->options().gc_sections()
1184 && parameters->options().shared())
1185 this->gc_mark_symbol_for_shlib(res);
1186
1187 if (local)
1188 this->force_local(res);
1189
1190 (*sympointers)[i] = res;
1191 }
1192 }
1193
1194 // Add a symbol from a plugin-claimed file.
1195
1196 template<int size, bool big_endian>
1197 Symbol*
1198 Symbol_table::add_from_pluginobj(
1199 Sized_pluginobj<size, big_endian>* obj,
1200 const char* name,
1201 const char* ver,
1202 elfcpp::Sym<size, big_endian>* sym)
1203 {
1204 unsigned int st_shndx = sym->get_st_shndx();
1205
1206 Stringpool::Key ver_key = 0;
1207 bool def = false;
1208 bool local = false;
1209
1210 if (ver != NULL)
1211 {
1212 ver = this->namepool_.add(ver, true, &ver_key);
1213 }
1214 // We don't want to assign a version to an undefined symbol,
1215 // even if it is listed in the version script. FIXME: What
1216 // about a common symbol?
1217 else
1218 {
1219 if (!this->version_script_.empty()
1220 && st_shndx != elfcpp::SHN_UNDEF)
1221 {
1222 // The symbol name did not have a version, but the
1223 // version script may assign a version anyway.
1224 std::string version;
1225 if (this->version_script_.get_symbol_version(name, &version))
1226 {
1227 // The version can be empty if the version script is
1228 // only used to force some symbols to be local.
1229 if (!version.empty())
1230 {
1231 ver = this->namepool_.add_with_length(version.c_str(),
1232 version.length(),
1233 true,
1234 &ver_key);
1235 def = true;
1236 }
1237 }
1238 else if (this->version_script_.symbol_is_local(name))
1239 local = true;
1240 }
1241 }
1242
1243 Stringpool::Key name_key;
1244 name = this->namepool_.add(name, true, &name_key);
1245
1246 Sized_symbol<size>* res;
1247 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1248 def, *sym, st_shndx, true, st_shndx);
1249
1250 if (local)
1251 this->force_local(res);
1252
1253 return res;
1254 }
1255
1256 // Add all the symbols in a dynamic object to the hash table.
1257
1258 template<int size, bool big_endian>
1259 void
1260 Symbol_table::add_from_dynobj(
1261 Sized_dynobj<size, big_endian>* dynobj,
1262 const unsigned char* syms,
1263 size_t count,
1264 const char* sym_names,
1265 size_t sym_name_size,
1266 const unsigned char* versym,
1267 size_t versym_size,
1268 const std::vector<const char*>* version_map,
1269 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1270 size_t* defined)
1271 {
1272 *defined = 0;
1273
1274 gold_assert(size == parameters->target().get_size());
1275
1276 if (dynobj->just_symbols())
1277 {
1278 gold_error(_("--just-symbols does not make sense with a shared object"));
1279 return;
1280 }
1281
1282 if (versym != NULL && versym_size / 2 < count)
1283 {
1284 dynobj->error(_("too few symbol versions"));
1285 return;
1286 }
1287
1288 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1289
1290 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1291 // weak aliases. This is necessary because if the dynamic object
1292 // provides the same variable under two names, one of which is a
1293 // weak definition, and the regular object refers to the weak
1294 // definition, we have to put both the weak definition and the
1295 // strong definition into the dynamic symbol table. Given a weak
1296 // definition, the only way that we can find the corresponding
1297 // strong definition, if any, is to search the symbol table.
1298 std::vector<Sized_symbol<size>*> object_symbols;
1299
1300 const unsigned char* p = syms;
1301 const unsigned char* vs = versym;
1302 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1303 {
1304 elfcpp::Sym<size, big_endian> sym(p);
1305
1306 if (sympointers != NULL)
1307 (*sympointers)[i] = NULL;
1308
1309 // Ignore symbols with local binding or that have
1310 // internal or hidden visibility.
1311 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1312 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1313 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1314 continue;
1315
1316 // A protected symbol in a shared library must be treated as a
1317 // normal symbol when viewed from outside the shared library.
1318 // Implement this by overriding the visibility here.
1319 elfcpp::Sym<size, big_endian>* psym = &sym;
1320 unsigned char symbuf[sym_size];
1321 elfcpp::Sym<size, big_endian> sym2(symbuf);
1322 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1323 {
1324 memcpy(symbuf, p, sym_size);
1325 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1326 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1327 psym = &sym2;
1328 }
1329
1330 unsigned int st_name = psym->get_st_name();
1331 if (st_name >= sym_name_size)
1332 {
1333 dynobj->error(_("bad symbol name offset %u at %zu"),
1334 st_name, i);
1335 continue;
1336 }
1337
1338 const char* name = sym_names + st_name;
1339
1340 bool is_ordinary;
1341 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1342 &is_ordinary);
1343
1344 if (st_shndx != elfcpp::SHN_UNDEF)
1345 ++*defined;
1346
1347 Sized_symbol<size>* res;
1348
1349 if (versym == NULL)
1350 {
1351 Stringpool::Key name_key;
1352 name = this->namepool_.add(name, true, &name_key);
1353 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1354 false, *psym, st_shndx, is_ordinary,
1355 st_shndx);
1356 }
1357 else
1358 {
1359 // Read the version information.
1360
1361 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1362
1363 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1364 v &= elfcpp::VERSYM_VERSION;
1365
1366 // The Sun documentation says that V can be VER_NDX_LOCAL,
1367 // or VER_NDX_GLOBAL, or a version index. The meaning of
1368 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1369 // The old GNU linker will happily generate VER_NDX_LOCAL
1370 // for an undefined symbol. I don't know what the Sun
1371 // linker will generate.
1372
1373 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1374 && st_shndx != elfcpp::SHN_UNDEF)
1375 {
1376 // This symbol should not be visible outside the object.
1377 continue;
1378 }
1379
1380 // At this point we are definitely going to add this symbol.
1381 Stringpool::Key name_key;
1382 name = this->namepool_.add(name, true, &name_key);
1383
1384 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1385 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1386 {
1387 // This symbol does not have a version.
1388 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1389 false, *psym, st_shndx, is_ordinary,
1390 st_shndx);
1391 }
1392 else
1393 {
1394 if (v >= version_map->size())
1395 {
1396 dynobj->error(_("versym for symbol %zu out of range: %u"),
1397 i, v);
1398 continue;
1399 }
1400
1401 const char* version = (*version_map)[v];
1402 if (version == NULL)
1403 {
1404 dynobj->error(_("versym for symbol %zu has no name: %u"),
1405 i, v);
1406 continue;
1407 }
1408
1409 Stringpool::Key version_key;
1410 version = this->namepool_.add(version, true, &version_key);
1411
1412 // If this is an absolute symbol, and the version name
1413 // and symbol name are the same, then this is the
1414 // version definition symbol. These symbols exist to
1415 // support using -u to pull in particular versions. We
1416 // do not want to record a version for them.
1417 if (st_shndx == elfcpp::SHN_ABS
1418 && !is_ordinary
1419 && name_key == version_key)
1420 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1421 false, *psym, st_shndx, is_ordinary,
1422 st_shndx);
1423 else
1424 {
1425 const bool def = (!hidden
1426 && st_shndx != elfcpp::SHN_UNDEF);
1427 res = this->add_from_object(dynobj, name, name_key, version,
1428 version_key, def, *psym, st_shndx,
1429 is_ordinary, st_shndx);
1430 }
1431 }
1432 }
1433
1434 // Note that it is possible that RES was overridden by an
1435 // earlier object, in which case it can't be aliased here.
1436 if (st_shndx != elfcpp::SHN_UNDEF
1437 && is_ordinary
1438 && psym->get_st_type() == elfcpp::STT_OBJECT
1439 && res->source() == Symbol::FROM_OBJECT
1440 && res->object() == dynobj)
1441 object_symbols.push_back(res);
1442
1443 if (sympointers != NULL)
1444 (*sympointers)[i] = res;
1445 }
1446
1447 this->record_weak_aliases(&object_symbols);
1448 }
1449
1450 // This is used to sort weak aliases. We sort them first by section
1451 // index, then by offset, then by weak ahead of strong.
1452
1453 template<int size>
1454 class Weak_alias_sorter
1455 {
1456 public:
1457 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1458 };
1459
1460 template<int size>
1461 bool
1462 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1463 const Sized_symbol<size>* s2) const
1464 {
1465 bool is_ordinary;
1466 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1467 gold_assert(is_ordinary);
1468 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1469 gold_assert(is_ordinary);
1470 if (s1_shndx != s2_shndx)
1471 return s1_shndx < s2_shndx;
1472
1473 if (s1->value() != s2->value())
1474 return s1->value() < s2->value();
1475 if (s1->binding() != s2->binding())
1476 {
1477 if (s1->binding() == elfcpp::STB_WEAK)
1478 return true;
1479 if (s2->binding() == elfcpp::STB_WEAK)
1480 return false;
1481 }
1482 return std::string(s1->name()) < std::string(s2->name());
1483 }
1484
1485 // SYMBOLS is a list of object symbols from a dynamic object. Look
1486 // for any weak aliases, and record them so that if we add the weak
1487 // alias to the dynamic symbol table, we also add the corresponding
1488 // strong symbol.
1489
1490 template<int size>
1491 void
1492 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1493 {
1494 // Sort the vector by section index, then by offset, then by weak
1495 // ahead of strong.
1496 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1497
1498 // Walk through the vector. For each weak definition, record
1499 // aliases.
1500 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1501 symbols->begin();
1502 p != symbols->end();
1503 ++p)
1504 {
1505 if ((*p)->binding() != elfcpp::STB_WEAK)
1506 continue;
1507
1508 // Build a circular list of weak aliases. Each symbol points to
1509 // the next one in the circular list.
1510
1511 Sized_symbol<size>* from_sym = *p;
1512 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1513 for (q = p + 1; q != symbols->end(); ++q)
1514 {
1515 bool dummy;
1516 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1517 || (*q)->value() != from_sym->value())
1518 break;
1519
1520 this->weak_aliases_[from_sym] = *q;
1521 from_sym->set_has_alias();
1522 from_sym = *q;
1523 }
1524
1525 if (from_sym != *p)
1526 {
1527 this->weak_aliases_[from_sym] = *p;
1528 from_sym->set_has_alias();
1529 }
1530
1531 p = q - 1;
1532 }
1533 }
1534
1535 // Create and return a specially defined symbol. If ONLY_IF_REF is
1536 // true, then only create the symbol if there is a reference to it.
1537 // If this does not return NULL, it sets *POLDSYM to the existing
1538 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1539 // resolve the newly created symbol to the old one. This
1540 // canonicalizes *PNAME and *PVERSION.
1541
1542 template<int size, bool big_endian>
1543 Sized_symbol<size>*
1544 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1545 bool only_if_ref,
1546 Sized_symbol<size>** poldsym,
1547 bool *resolve_oldsym)
1548 {
1549 *resolve_oldsym = false;
1550
1551 // If the caller didn't give us a version, see if we get one from
1552 // the version script.
1553 std::string v;
1554 bool is_default_version = false;
1555 if (*pversion == NULL)
1556 {
1557 if (this->version_script_.get_symbol_version(*pname, &v))
1558 {
1559 if (!v.empty())
1560 *pversion = v.c_str();
1561
1562 // If we get the version from a version script, then we are
1563 // also the default version.
1564 is_default_version = true;
1565 }
1566 }
1567
1568 Symbol* oldsym;
1569 Sized_symbol<size>* sym;
1570
1571 bool add_to_table = false;
1572 typename Symbol_table_type::iterator add_loc = this->table_.end();
1573 bool add_def_to_table = false;
1574 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1575
1576 if (only_if_ref)
1577 {
1578 oldsym = this->lookup(*pname, *pversion);
1579 if (oldsym == NULL && is_default_version)
1580 oldsym = this->lookup(*pname, NULL);
1581 if (oldsym == NULL || !oldsym->is_undefined())
1582 return NULL;
1583
1584 *pname = oldsym->name();
1585 if (!is_default_version)
1586 *pversion = oldsym->version();
1587 }
1588 else
1589 {
1590 // Canonicalize NAME and VERSION.
1591 Stringpool::Key name_key;
1592 *pname = this->namepool_.add(*pname, true, &name_key);
1593
1594 Stringpool::Key version_key = 0;
1595 if (*pversion != NULL)
1596 *pversion = this->namepool_.add(*pversion, true, &version_key);
1597
1598 Symbol* const snull = NULL;
1599 std::pair<typename Symbol_table_type::iterator, bool> ins =
1600 this->table_.insert(std::make_pair(std::make_pair(name_key,
1601 version_key),
1602 snull));
1603
1604 std::pair<typename Symbol_table_type::iterator, bool> insdef =
1605 std::make_pair(this->table_.end(), false);
1606 if (is_default_version)
1607 {
1608 const Stringpool::Key vnull = 0;
1609 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
1610 vnull),
1611 snull));
1612 }
1613
1614 if (!ins.second)
1615 {
1616 // We already have a symbol table entry for NAME/VERSION.
1617 oldsym = ins.first->second;
1618 gold_assert(oldsym != NULL);
1619
1620 if (is_default_version)
1621 {
1622 Sized_symbol<size>* soldsym =
1623 this->get_sized_symbol<size>(oldsym);
1624 this->define_default_version<size, big_endian>(soldsym,
1625 insdef.second,
1626 insdef.first);
1627 }
1628 }
1629 else
1630 {
1631 // We haven't seen this symbol before.
1632 gold_assert(ins.first->second == NULL);
1633
1634 add_to_table = true;
1635 add_loc = ins.first;
1636
1637 if (is_default_version && !insdef.second)
1638 {
1639 // We are adding NAME/VERSION, and it is the default
1640 // version. We already have an entry for NAME/NULL.
1641 oldsym = insdef.first->second;
1642 *resolve_oldsym = true;
1643 }
1644 else
1645 {
1646 oldsym = NULL;
1647
1648 if (is_default_version)
1649 {
1650 add_def_to_table = true;
1651 add_def_loc = insdef.first;
1652 }
1653 }
1654 }
1655 }
1656
1657 const Target& target = parameters->target();
1658 if (!target.has_make_symbol())
1659 sym = new Sized_symbol<size>();
1660 else
1661 {
1662 Sized_target<size, big_endian>* sized_target =
1663 parameters->sized_target<size, big_endian>();
1664 sym = sized_target->make_symbol();
1665 if (sym == NULL)
1666 return NULL;
1667 }
1668
1669 if (add_to_table)
1670 add_loc->second = sym;
1671 else
1672 gold_assert(oldsym != NULL);
1673
1674 if (add_def_to_table)
1675 add_def_loc->second = sym;
1676
1677 *poldsym = this->get_sized_symbol<size>(oldsym);
1678
1679 return sym;
1680 }
1681
1682 // Define a symbol based on an Output_data.
1683
1684 Symbol*
1685 Symbol_table::define_in_output_data(const char* name,
1686 const char* version,
1687 Output_data* od,
1688 uint64_t value,
1689 uint64_t symsize,
1690 elfcpp::STT type,
1691 elfcpp::STB binding,
1692 elfcpp::STV visibility,
1693 unsigned char nonvis,
1694 bool offset_is_from_end,
1695 bool only_if_ref)
1696 {
1697 if (parameters->target().get_size() == 32)
1698 {
1699 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1700 return this->do_define_in_output_data<32>(name, version, od,
1701 value, symsize, type, binding,
1702 visibility, nonvis,
1703 offset_is_from_end,
1704 only_if_ref);
1705 #else
1706 gold_unreachable();
1707 #endif
1708 }
1709 else if (parameters->target().get_size() == 64)
1710 {
1711 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1712 return this->do_define_in_output_data<64>(name, version, od,
1713 value, symsize, type, binding,
1714 visibility, nonvis,
1715 offset_is_from_end,
1716 only_if_ref);
1717 #else
1718 gold_unreachable();
1719 #endif
1720 }
1721 else
1722 gold_unreachable();
1723 }
1724
1725 // Define a symbol in an Output_data, sized version.
1726
1727 template<int size>
1728 Sized_symbol<size>*
1729 Symbol_table::do_define_in_output_data(
1730 const char* name,
1731 const char* version,
1732 Output_data* od,
1733 typename elfcpp::Elf_types<size>::Elf_Addr value,
1734 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1735 elfcpp::STT type,
1736 elfcpp::STB binding,
1737 elfcpp::STV visibility,
1738 unsigned char nonvis,
1739 bool offset_is_from_end,
1740 bool only_if_ref)
1741 {
1742 Sized_symbol<size>* sym;
1743 Sized_symbol<size>* oldsym;
1744 bool resolve_oldsym;
1745
1746 if (parameters->target().is_big_endian())
1747 {
1748 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1749 sym = this->define_special_symbol<size, true>(&name, &version,
1750 only_if_ref, &oldsym,
1751 &resolve_oldsym);
1752 #else
1753 gold_unreachable();
1754 #endif
1755 }
1756 else
1757 {
1758 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1759 sym = this->define_special_symbol<size, false>(&name, &version,
1760 only_if_ref, &oldsym,
1761 &resolve_oldsym);
1762 #else
1763 gold_unreachable();
1764 #endif
1765 }
1766
1767 if (sym == NULL)
1768 return NULL;
1769
1770 sym->init_output_data(name, version, od, value, symsize, type, binding,
1771 visibility, nonvis, offset_is_from_end);
1772
1773 if (oldsym == NULL)
1774 {
1775 if (binding == elfcpp::STB_LOCAL
1776 || this->version_script_.symbol_is_local(name))
1777 this->force_local(sym);
1778 else if (version != NULL)
1779 sym->set_is_default();
1780 return sym;
1781 }
1782
1783 if (Symbol_table::should_override_with_special(oldsym))
1784 this->override_with_special(oldsym, sym);
1785
1786 if (resolve_oldsym)
1787 return sym;
1788 else
1789 {
1790 delete sym;
1791 return oldsym;
1792 }
1793 }
1794
1795 // Define a symbol based on an Output_segment.
1796
1797 Symbol*
1798 Symbol_table::define_in_output_segment(const char* name,
1799 const char* version, Output_segment* os,
1800 uint64_t value,
1801 uint64_t symsize,
1802 elfcpp::STT type,
1803 elfcpp::STB binding,
1804 elfcpp::STV visibility,
1805 unsigned char nonvis,
1806 Symbol::Segment_offset_base offset_base,
1807 bool only_if_ref)
1808 {
1809 if (parameters->target().get_size() == 32)
1810 {
1811 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1812 return this->do_define_in_output_segment<32>(name, version, os,
1813 value, symsize, type,
1814 binding, visibility, nonvis,
1815 offset_base, only_if_ref);
1816 #else
1817 gold_unreachable();
1818 #endif
1819 }
1820 else if (parameters->target().get_size() == 64)
1821 {
1822 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1823 return this->do_define_in_output_segment<64>(name, version, os,
1824 value, symsize, type,
1825 binding, visibility, nonvis,
1826 offset_base, only_if_ref);
1827 #else
1828 gold_unreachable();
1829 #endif
1830 }
1831 else
1832 gold_unreachable();
1833 }
1834
1835 // Define a symbol in an Output_segment, sized version.
1836
1837 template<int size>
1838 Sized_symbol<size>*
1839 Symbol_table::do_define_in_output_segment(
1840 const char* name,
1841 const char* version,
1842 Output_segment* os,
1843 typename elfcpp::Elf_types<size>::Elf_Addr value,
1844 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1845 elfcpp::STT type,
1846 elfcpp::STB binding,
1847 elfcpp::STV visibility,
1848 unsigned char nonvis,
1849 Symbol::Segment_offset_base offset_base,
1850 bool only_if_ref)
1851 {
1852 Sized_symbol<size>* sym;
1853 Sized_symbol<size>* oldsym;
1854 bool resolve_oldsym;
1855
1856 if (parameters->target().is_big_endian())
1857 {
1858 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1859 sym = this->define_special_symbol<size, true>(&name, &version,
1860 only_if_ref, &oldsym,
1861 &resolve_oldsym);
1862 #else
1863 gold_unreachable();
1864 #endif
1865 }
1866 else
1867 {
1868 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1869 sym = this->define_special_symbol<size, false>(&name, &version,
1870 only_if_ref, &oldsym,
1871 &resolve_oldsym);
1872 #else
1873 gold_unreachable();
1874 #endif
1875 }
1876
1877 if (sym == NULL)
1878 return NULL;
1879
1880 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1881 visibility, nonvis, offset_base);
1882
1883 if (oldsym == NULL)
1884 {
1885 if (binding == elfcpp::STB_LOCAL
1886 || this->version_script_.symbol_is_local(name))
1887 this->force_local(sym);
1888 else if (version != NULL)
1889 sym->set_is_default();
1890 return sym;
1891 }
1892
1893 if (Symbol_table::should_override_with_special(oldsym))
1894 this->override_with_special(oldsym, sym);
1895
1896 if (resolve_oldsym)
1897 return sym;
1898 else
1899 {
1900 delete sym;
1901 return oldsym;
1902 }
1903 }
1904
1905 // Define a special symbol with a constant value. It is a multiple
1906 // definition error if this symbol is already defined.
1907
1908 Symbol*
1909 Symbol_table::define_as_constant(const char* name,
1910 const char* version,
1911 uint64_t value,
1912 uint64_t symsize,
1913 elfcpp::STT type,
1914 elfcpp::STB binding,
1915 elfcpp::STV visibility,
1916 unsigned char nonvis,
1917 bool only_if_ref,
1918 bool force_override)
1919 {
1920 if (parameters->target().get_size() == 32)
1921 {
1922 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1923 return this->do_define_as_constant<32>(name, version, value,
1924 symsize, type, binding,
1925 visibility, nonvis, only_if_ref,
1926 force_override);
1927 #else
1928 gold_unreachable();
1929 #endif
1930 }
1931 else if (parameters->target().get_size() == 64)
1932 {
1933 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1934 return this->do_define_as_constant<64>(name, version, value,
1935 symsize, type, binding,
1936 visibility, nonvis, only_if_ref,
1937 force_override);
1938 #else
1939 gold_unreachable();
1940 #endif
1941 }
1942 else
1943 gold_unreachable();
1944 }
1945
1946 // Define a symbol as a constant, sized version.
1947
1948 template<int size>
1949 Sized_symbol<size>*
1950 Symbol_table::do_define_as_constant(
1951 const char* name,
1952 const char* version,
1953 typename elfcpp::Elf_types<size>::Elf_Addr value,
1954 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1955 elfcpp::STT type,
1956 elfcpp::STB binding,
1957 elfcpp::STV visibility,
1958 unsigned char nonvis,
1959 bool only_if_ref,
1960 bool force_override)
1961 {
1962 Sized_symbol<size>* sym;
1963 Sized_symbol<size>* oldsym;
1964 bool resolve_oldsym;
1965
1966 if (parameters->target().is_big_endian())
1967 {
1968 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1969 sym = this->define_special_symbol<size, true>(&name, &version,
1970 only_if_ref, &oldsym,
1971 &resolve_oldsym);
1972 #else
1973 gold_unreachable();
1974 #endif
1975 }
1976 else
1977 {
1978 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1979 sym = this->define_special_symbol<size, false>(&name, &version,
1980 only_if_ref, &oldsym,
1981 &resolve_oldsym);
1982 #else
1983 gold_unreachable();
1984 #endif
1985 }
1986
1987 if (sym == NULL)
1988 return NULL;
1989
1990 sym->init_constant(name, version, value, symsize, type, binding, visibility,
1991 nonvis);
1992
1993 if (oldsym == NULL)
1994 {
1995 // Version symbols are absolute symbols with name == version.
1996 // We don't want to force them to be local.
1997 if ((version == NULL
1998 || name != version
1999 || value != 0)
2000 && (binding == elfcpp::STB_LOCAL
2001 || this->version_script_.symbol_is_local(name)))
2002 this->force_local(sym);
2003 else if (version != NULL
2004 && (name != version || value != 0))
2005 sym->set_is_default();
2006 return sym;
2007 }
2008
2009 if (force_override || Symbol_table::should_override_with_special(oldsym))
2010 this->override_with_special(oldsym, sym);
2011
2012 if (resolve_oldsym)
2013 return sym;
2014 else
2015 {
2016 delete sym;
2017 return oldsym;
2018 }
2019 }
2020
2021 // Define a set of symbols in output sections.
2022
2023 void
2024 Symbol_table::define_symbols(const Layout* layout, int count,
2025 const Define_symbol_in_section* p,
2026 bool only_if_ref)
2027 {
2028 for (int i = 0; i < count; ++i, ++p)
2029 {
2030 Output_section* os = layout->find_output_section(p->output_section);
2031 if (os != NULL)
2032 this->define_in_output_data(p->name, NULL, os, p->value,
2033 p->size, p->type, p->binding,
2034 p->visibility, p->nonvis,
2035 p->offset_is_from_end,
2036 only_if_ref || p->only_if_ref);
2037 else
2038 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2039 p->binding, p->visibility, p->nonvis,
2040 only_if_ref || p->only_if_ref,
2041 false);
2042 }
2043 }
2044
2045 // Define a set of symbols in output segments.
2046
2047 void
2048 Symbol_table::define_symbols(const Layout* layout, int count,
2049 const Define_symbol_in_segment* p,
2050 bool only_if_ref)
2051 {
2052 for (int i = 0; i < count; ++i, ++p)
2053 {
2054 Output_segment* os = layout->find_output_segment(p->segment_type,
2055 p->segment_flags_set,
2056 p->segment_flags_clear);
2057 if (os != NULL)
2058 this->define_in_output_segment(p->name, NULL, os, p->value,
2059 p->size, p->type, p->binding,
2060 p->visibility, p->nonvis,
2061 p->offset_base,
2062 only_if_ref || p->only_if_ref);
2063 else
2064 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2065 p->binding, p->visibility, p->nonvis,
2066 only_if_ref || p->only_if_ref,
2067 false);
2068 }
2069 }
2070
2071 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2072 // symbol should be defined--typically a .dyn.bss section. VALUE is
2073 // the offset within POSD.
2074
2075 template<int size>
2076 void
2077 Symbol_table::define_with_copy_reloc(
2078 Sized_symbol<size>* csym,
2079 Output_data* posd,
2080 typename elfcpp::Elf_types<size>::Elf_Addr value)
2081 {
2082 gold_assert(csym->is_from_dynobj());
2083 gold_assert(!csym->is_copied_from_dynobj());
2084 Object* object = csym->object();
2085 gold_assert(object->is_dynamic());
2086 Dynobj* dynobj = static_cast<Dynobj*>(object);
2087
2088 // Our copied variable has to override any variable in a shared
2089 // library.
2090 elfcpp::STB binding = csym->binding();
2091 if (binding == elfcpp::STB_WEAK)
2092 binding = elfcpp::STB_GLOBAL;
2093
2094 this->define_in_output_data(csym->name(), csym->version(),
2095 posd, value, csym->symsize(),
2096 csym->type(), binding,
2097 csym->visibility(), csym->nonvis(),
2098 false, false);
2099
2100 csym->set_is_copied_from_dynobj();
2101 csym->set_needs_dynsym_entry();
2102
2103 this->copied_symbol_dynobjs_[csym] = dynobj;
2104
2105 // We have now defined all aliases, but we have not entered them all
2106 // in the copied_symbol_dynobjs_ map.
2107 if (csym->has_alias())
2108 {
2109 Symbol* sym = csym;
2110 while (true)
2111 {
2112 sym = this->weak_aliases_[sym];
2113 if (sym == csym)
2114 break;
2115 gold_assert(sym->output_data() == posd);
2116
2117 sym->set_is_copied_from_dynobj();
2118 this->copied_symbol_dynobjs_[sym] = dynobj;
2119 }
2120 }
2121 }
2122
2123 // SYM is defined using a COPY reloc. Return the dynamic object where
2124 // the original definition was found.
2125
2126 Dynobj*
2127 Symbol_table::get_copy_source(const Symbol* sym) const
2128 {
2129 gold_assert(sym->is_copied_from_dynobj());
2130 Copied_symbol_dynobjs::const_iterator p =
2131 this->copied_symbol_dynobjs_.find(sym);
2132 gold_assert(p != this->copied_symbol_dynobjs_.end());
2133 return p->second;
2134 }
2135
2136 // Add any undefined symbols named on the command line.
2137
2138 void
2139 Symbol_table::add_undefined_symbols_from_command_line()
2140 {
2141 if (parameters->options().any_undefined())
2142 {
2143 if (parameters->target().get_size() == 32)
2144 {
2145 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2146 this->do_add_undefined_symbols_from_command_line<32>();
2147 #else
2148 gold_unreachable();
2149 #endif
2150 }
2151 else if (parameters->target().get_size() == 64)
2152 {
2153 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2154 this->do_add_undefined_symbols_from_command_line<64>();
2155 #else
2156 gold_unreachable();
2157 #endif
2158 }
2159 else
2160 gold_unreachable();
2161 }
2162 }
2163
2164 template<int size>
2165 void
2166 Symbol_table::do_add_undefined_symbols_from_command_line()
2167 {
2168 for (options::String_set::const_iterator p =
2169 parameters->options().undefined_begin();
2170 p != parameters->options().undefined_end();
2171 ++p)
2172 {
2173 const char* name = p->c_str();
2174
2175 if (this->lookup(name) != NULL)
2176 continue;
2177
2178 const char* version = NULL;
2179
2180 Sized_symbol<size>* sym;
2181 Sized_symbol<size>* oldsym;
2182 bool resolve_oldsym;
2183 if (parameters->target().is_big_endian())
2184 {
2185 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2186 sym = this->define_special_symbol<size, true>(&name, &version,
2187 false, &oldsym,
2188 &resolve_oldsym);
2189 #else
2190 gold_unreachable();
2191 #endif
2192 }
2193 else
2194 {
2195 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2196 sym = this->define_special_symbol<size, false>(&name, &version,
2197 false, &oldsym,
2198 &resolve_oldsym);
2199 #else
2200 gold_unreachable();
2201 #endif
2202 }
2203
2204 gold_assert(oldsym == NULL);
2205
2206 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2207 elfcpp::STV_DEFAULT, 0);
2208 ++this->saw_undefined_;
2209 }
2210 }
2211
2212 // Set the dynamic symbol indexes. INDEX is the index of the first
2213 // global dynamic symbol. Pointers to the symbols are stored into the
2214 // vector SYMS. The names are added to DYNPOOL. This returns an
2215 // updated dynamic symbol index.
2216
2217 unsigned int
2218 Symbol_table::set_dynsym_indexes(unsigned int index,
2219 std::vector<Symbol*>* syms,
2220 Stringpool* dynpool,
2221 Versions* versions)
2222 {
2223 for (Symbol_table_type::iterator p = this->table_.begin();
2224 p != this->table_.end();
2225 ++p)
2226 {
2227 Symbol* sym = p->second;
2228
2229 // Note that SYM may already have a dynamic symbol index, since
2230 // some symbols appear more than once in the symbol table, with
2231 // and without a version.
2232
2233 if (!sym->should_add_dynsym_entry())
2234 sym->set_dynsym_index(-1U);
2235 else if (!sym->has_dynsym_index())
2236 {
2237 sym->set_dynsym_index(index);
2238 ++index;
2239 syms->push_back(sym);
2240 dynpool->add(sym->name(), false, NULL);
2241
2242 // Record any version information.
2243 if (sym->version() != NULL)
2244 versions->record_version(this, dynpool, sym);
2245 }
2246 }
2247
2248 // Finish up the versions. In some cases this may add new dynamic
2249 // symbols.
2250 index = versions->finalize(this, index, syms);
2251
2252 return index;
2253 }
2254
2255 // Set the final values for all the symbols. The index of the first
2256 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2257 // file offset OFF. Add their names to POOL. Return the new file
2258 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2259
2260 off_t
2261 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2262 size_t dyncount, Stringpool* pool,
2263 unsigned int *plocal_symcount)
2264 {
2265 off_t ret;
2266
2267 gold_assert(*plocal_symcount != 0);
2268 this->first_global_index_ = *plocal_symcount;
2269
2270 this->dynamic_offset_ = dynoff;
2271 this->first_dynamic_global_index_ = dyn_global_index;
2272 this->dynamic_count_ = dyncount;
2273
2274 if (parameters->target().get_size() == 32)
2275 {
2276 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2277 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2278 #else
2279 gold_unreachable();
2280 #endif
2281 }
2282 else if (parameters->target().get_size() == 64)
2283 {
2284 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2285 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2286 #else
2287 gold_unreachable();
2288 #endif
2289 }
2290 else
2291 gold_unreachable();
2292
2293 // Now that we have the final symbol table, we can reliably note
2294 // which symbols should get warnings.
2295 this->warnings_.note_warnings(this);
2296
2297 return ret;
2298 }
2299
2300 // SYM is going into the symbol table at *PINDEX. Add the name to
2301 // POOL, update *PINDEX and *POFF.
2302
2303 template<int size>
2304 void
2305 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2306 unsigned int* pindex, off_t* poff)
2307 {
2308 sym->set_symtab_index(*pindex);
2309 pool->add(sym->name(), false, NULL);
2310 ++*pindex;
2311 *poff += elfcpp::Elf_sizes<size>::sym_size;
2312 }
2313
2314 // Set the final value for all the symbols. This is called after
2315 // Layout::finalize, so all the output sections have their final
2316 // address.
2317
2318 template<int size>
2319 off_t
2320 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2321 unsigned int* plocal_symcount)
2322 {
2323 off = align_address(off, size >> 3);
2324 this->offset_ = off;
2325
2326 unsigned int index = *plocal_symcount;
2327 const unsigned int orig_index = index;
2328
2329 // First do all the symbols which have been forced to be local, as
2330 // they must appear before all global symbols.
2331 for (Forced_locals::iterator p = this->forced_locals_.begin();
2332 p != this->forced_locals_.end();
2333 ++p)
2334 {
2335 Symbol* sym = *p;
2336 gold_assert(sym->is_forced_local());
2337 if (this->sized_finalize_symbol<size>(sym))
2338 {
2339 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2340 ++*plocal_symcount;
2341 }
2342 }
2343
2344 // Now do all the remaining symbols.
2345 for (Symbol_table_type::iterator p = this->table_.begin();
2346 p != this->table_.end();
2347 ++p)
2348 {
2349 Symbol* sym = p->second;
2350 if (this->sized_finalize_symbol<size>(sym))
2351 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2352 }
2353
2354 this->output_count_ = index - orig_index;
2355
2356 return off;
2357 }
2358
2359 // Compute the final value of SYM and store status in location PSTATUS.
2360 // During relaxation, this may be called multiple times for a symbol to
2361 // compute its would-be final value in each relaxation pass.
2362
2363 template<int size>
2364 typename Sized_symbol<size>::Value_type
2365 Symbol_table::compute_final_value(
2366 const Sized_symbol<size>* sym,
2367 Compute_final_value_status* pstatus) const
2368 {
2369 typedef typename Sized_symbol<size>::Value_type Value_type;
2370 Value_type value;
2371
2372 switch (sym->source())
2373 {
2374 case Symbol::FROM_OBJECT:
2375 {
2376 bool is_ordinary;
2377 unsigned int shndx = sym->shndx(&is_ordinary);
2378
2379 if (!is_ordinary
2380 && shndx != elfcpp::SHN_ABS
2381 && !Symbol::is_common_shndx(shndx))
2382 {
2383 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2384 return 0;
2385 }
2386
2387 Object* symobj = sym->object();
2388 if (symobj->is_dynamic())
2389 {
2390 value = 0;
2391 shndx = elfcpp::SHN_UNDEF;
2392 }
2393 else if (symobj->pluginobj() != NULL)
2394 {
2395 value = 0;
2396 shndx = elfcpp::SHN_UNDEF;
2397 }
2398 else if (shndx == elfcpp::SHN_UNDEF)
2399 value = 0;
2400 else if (!is_ordinary
2401 && (shndx == elfcpp::SHN_ABS
2402 || Symbol::is_common_shndx(shndx)))
2403 value = sym->value();
2404 else
2405 {
2406 Relobj* relobj = static_cast<Relobj*>(symobj);
2407 Output_section* os = relobj->output_section(shndx);
2408 uint64_t secoff64 = relobj->output_section_offset(shndx);
2409
2410 if (this->is_section_folded(relobj, shndx))
2411 {
2412 gold_assert(os == NULL);
2413 // Get the os of the section it is folded onto.
2414 Section_id folded = this->icf_->get_folded_section(relobj,
2415 shndx);
2416 gold_assert(folded.first != NULL);
2417 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2418 os = folded_obj->output_section(folded.second);
2419 gold_assert(os != NULL);
2420 secoff64 = folded_obj->output_section_offset(folded.second);
2421 }
2422
2423 if (os == NULL)
2424 {
2425 bool static_or_reloc = (parameters->doing_static_link() ||
2426 parameters->options().relocatable());
2427 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2428
2429 *pstatus = CFVS_NO_OUTPUT_SECTION;
2430 return 0;
2431 }
2432
2433 if (secoff64 == -1ULL)
2434 {
2435 // The section needs special handling (e.g., a merge section).
2436
2437 value = os->output_address(relobj, shndx, sym->value());
2438 }
2439 else
2440 {
2441 Value_type secoff =
2442 convert_types<Value_type, uint64_t>(secoff64);
2443 if (sym->type() == elfcpp::STT_TLS)
2444 value = sym->value() + os->tls_offset() + secoff;
2445 else
2446 value = sym->value() + os->address() + secoff;
2447 }
2448 }
2449 }
2450 break;
2451
2452 case Symbol::IN_OUTPUT_DATA:
2453 {
2454 Output_data* od = sym->output_data();
2455 value = sym->value();
2456 if (sym->type() != elfcpp::STT_TLS)
2457 value += od->address();
2458 else
2459 {
2460 Output_section* os = od->output_section();
2461 gold_assert(os != NULL);
2462 value += os->tls_offset() + (od->address() - os->address());
2463 }
2464 if (sym->offset_is_from_end())
2465 value += od->data_size();
2466 }
2467 break;
2468
2469 case Symbol::IN_OUTPUT_SEGMENT:
2470 {
2471 Output_segment* os = sym->output_segment();
2472 value = sym->value();
2473 if (sym->type() != elfcpp::STT_TLS)
2474 value += os->vaddr();
2475 switch (sym->offset_base())
2476 {
2477 case Symbol::SEGMENT_START:
2478 break;
2479 case Symbol::SEGMENT_END:
2480 value += os->memsz();
2481 break;
2482 case Symbol::SEGMENT_BSS:
2483 value += os->filesz();
2484 break;
2485 default:
2486 gold_unreachable();
2487 }
2488 }
2489 break;
2490
2491 case Symbol::IS_CONSTANT:
2492 value = sym->value();
2493 break;
2494
2495 case Symbol::IS_UNDEFINED:
2496 value = 0;
2497 break;
2498
2499 default:
2500 gold_unreachable();
2501 }
2502
2503 *pstatus = CFVS_OK;
2504 return value;
2505 }
2506
2507 // Finalize the symbol SYM. This returns true if the symbol should be
2508 // added to the symbol table, false otherwise.
2509
2510 template<int size>
2511 bool
2512 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2513 {
2514 typedef typename Sized_symbol<size>::Value_type Value_type;
2515
2516 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2517
2518 // The default version of a symbol may appear twice in the symbol
2519 // table. We only need to finalize it once.
2520 if (sym->has_symtab_index())
2521 return false;
2522
2523 if (!sym->in_reg())
2524 {
2525 gold_assert(!sym->has_symtab_index());
2526 sym->set_symtab_index(-1U);
2527 gold_assert(sym->dynsym_index() == -1U);
2528 return false;
2529 }
2530
2531 // Compute final symbol value.
2532 Compute_final_value_status status;
2533 Value_type value = this->compute_final_value(sym, &status);
2534
2535 switch (status)
2536 {
2537 case CFVS_OK:
2538 break;
2539 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2540 {
2541 bool is_ordinary;
2542 unsigned int shndx = sym->shndx(&is_ordinary);
2543 gold_error(_("%s: unsupported symbol section 0x%x"),
2544 sym->demangled_name().c_str(), shndx);
2545 }
2546 break;
2547 case CFVS_NO_OUTPUT_SECTION:
2548 sym->set_symtab_index(-1U);
2549 return false;
2550 default:
2551 gold_unreachable();
2552 }
2553
2554 sym->set_value(value);
2555
2556 if (parameters->options().strip_all()
2557 || !parameters->options().should_retain_symbol(sym->name()))
2558 {
2559 sym->set_symtab_index(-1U);
2560 return false;
2561 }
2562
2563 return true;
2564 }
2565
2566 // Write out the global symbols.
2567
2568 void
2569 Symbol_table::write_globals(const Stringpool* sympool,
2570 const Stringpool* dynpool,
2571 Output_symtab_xindex* symtab_xindex,
2572 Output_symtab_xindex* dynsym_xindex,
2573 Output_file* of) const
2574 {
2575 switch (parameters->size_and_endianness())
2576 {
2577 #ifdef HAVE_TARGET_32_LITTLE
2578 case Parameters::TARGET_32_LITTLE:
2579 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2580 dynsym_xindex, of);
2581 break;
2582 #endif
2583 #ifdef HAVE_TARGET_32_BIG
2584 case Parameters::TARGET_32_BIG:
2585 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2586 dynsym_xindex, of);
2587 break;
2588 #endif
2589 #ifdef HAVE_TARGET_64_LITTLE
2590 case Parameters::TARGET_64_LITTLE:
2591 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2592 dynsym_xindex, of);
2593 break;
2594 #endif
2595 #ifdef HAVE_TARGET_64_BIG
2596 case Parameters::TARGET_64_BIG:
2597 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2598 dynsym_xindex, of);
2599 break;
2600 #endif
2601 default:
2602 gold_unreachable();
2603 }
2604 }
2605
2606 // Write out the global symbols.
2607
2608 template<int size, bool big_endian>
2609 void
2610 Symbol_table::sized_write_globals(const Stringpool* sympool,
2611 const Stringpool* dynpool,
2612 Output_symtab_xindex* symtab_xindex,
2613 Output_symtab_xindex* dynsym_xindex,
2614 Output_file* of) const
2615 {
2616 const Target& target = parameters->target();
2617
2618 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2619
2620 const unsigned int output_count = this->output_count_;
2621 const section_size_type oview_size = output_count * sym_size;
2622 const unsigned int first_global_index = this->first_global_index_;
2623 unsigned char* psyms;
2624 if (this->offset_ == 0 || output_count == 0)
2625 psyms = NULL;
2626 else
2627 psyms = of->get_output_view(this->offset_, oview_size);
2628
2629 const unsigned int dynamic_count = this->dynamic_count_;
2630 const section_size_type dynamic_size = dynamic_count * sym_size;
2631 const unsigned int first_dynamic_global_index =
2632 this->first_dynamic_global_index_;
2633 unsigned char* dynamic_view;
2634 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2635 dynamic_view = NULL;
2636 else
2637 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2638
2639 for (Symbol_table_type::const_iterator p = this->table_.begin();
2640 p != this->table_.end();
2641 ++p)
2642 {
2643 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2644
2645 // Possibly warn about unresolved symbols in shared libraries.
2646 this->warn_about_undefined_dynobj_symbol(sym);
2647
2648 unsigned int sym_index = sym->symtab_index();
2649 unsigned int dynsym_index;
2650 if (dynamic_view == NULL)
2651 dynsym_index = -1U;
2652 else
2653 dynsym_index = sym->dynsym_index();
2654
2655 if (sym_index == -1U && dynsym_index == -1U)
2656 {
2657 // This symbol is not included in the output file.
2658 continue;
2659 }
2660
2661 unsigned int shndx;
2662 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2663 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2664 switch (sym->source())
2665 {
2666 case Symbol::FROM_OBJECT:
2667 {
2668 bool is_ordinary;
2669 unsigned int in_shndx = sym->shndx(&is_ordinary);
2670
2671 if (!is_ordinary
2672 && in_shndx != elfcpp::SHN_ABS
2673 && !Symbol::is_common_shndx(in_shndx))
2674 {
2675 gold_error(_("%s: unsupported symbol section 0x%x"),
2676 sym->demangled_name().c_str(), in_shndx);
2677 shndx = in_shndx;
2678 }
2679 else
2680 {
2681 Object* symobj = sym->object();
2682 if (symobj->is_dynamic())
2683 {
2684 if (sym->needs_dynsym_value())
2685 dynsym_value = target.dynsym_value(sym);
2686 shndx = elfcpp::SHN_UNDEF;
2687 }
2688 else if (symobj->pluginobj() != NULL)
2689 shndx = elfcpp::SHN_UNDEF;
2690 else if (in_shndx == elfcpp::SHN_UNDEF
2691 || (!is_ordinary
2692 && (in_shndx == elfcpp::SHN_ABS
2693 || Symbol::is_common_shndx(in_shndx))))
2694 shndx = in_shndx;
2695 else
2696 {
2697 Relobj* relobj = static_cast<Relobj*>(symobj);
2698 Output_section* os = relobj->output_section(in_shndx);
2699 if (this->is_section_folded(relobj, in_shndx))
2700 {
2701 // This global symbol must be written out even though
2702 // it is folded.
2703 // Get the os of the section it is folded onto.
2704 Section_id folded =
2705 this->icf_->get_folded_section(relobj, in_shndx);
2706 gold_assert(folded.first !=NULL);
2707 Relobj* folded_obj =
2708 reinterpret_cast<Relobj*>(folded.first);
2709 os = folded_obj->output_section(folded.second);
2710 gold_assert(os != NULL);
2711 }
2712 gold_assert(os != NULL);
2713 shndx = os->out_shndx();
2714
2715 if (shndx >= elfcpp::SHN_LORESERVE)
2716 {
2717 if (sym_index != -1U)
2718 symtab_xindex->add(sym_index, shndx);
2719 if (dynsym_index != -1U)
2720 dynsym_xindex->add(dynsym_index, shndx);
2721 shndx = elfcpp::SHN_XINDEX;
2722 }
2723
2724 // In object files symbol values are section
2725 // relative.
2726 if (parameters->options().relocatable())
2727 sym_value -= os->address();
2728 }
2729 }
2730 }
2731 break;
2732
2733 case Symbol::IN_OUTPUT_DATA:
2734 shndx = sym->output_data()->out_shndx();
2735 if (shndx >= elfcpp::SHN_LORESERVE)
2736 {
2737 if (sym_index != -1U)
2738 symtab_xindex->add(sym_index, shndx);
2739 if (dynsym_index != -1U)
2740 dynsym_xindex->add(dynsym_index, shndx);
2741 shndx = elfcpp::SHN_XINDEX;
2742 }
2743 break;
2744
2745 case Symbol::IN_OUTPUT_SEGMENT:
2746 shndx = elfcpp::SHN_ABS;
2747 break;
2748
2749 case Symbol::IS_CONSTANT:
2750 shndx = elfcpp::SHN_ABS;
2751 break;
2752
2753 case Symbol::IS_UNDEFINED:
2754 shndx = elfcpp::SHN_UNDEF;
2755 break;
2756
2757 default:
2758 gold_unreachable();
2759 }
2760
2761 if (sym_index != -1U)
2762 {
2763 sym_index -= first_global_index;
2764 gold_assert(sym_index < output_count);
2765 unsigned char* ps = psyms + (sym_index * sym_size);
2766 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2767 sympool, ps);
2768 }
2769
2770 if (dynsym_index != -1U)
2771 {
2772 dynsym_index -= first_dynamic_global_index;
2773 gold_assert(dynsym_index < dynamic_count);
2774 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2775 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2776 dynpool, pd);
2777 }
2778 }
2779
2780 of->write_output_view(this->offset_, oview_size, psyms);
2781 if (dynamic_view != NULL)
2782 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2783 }
2784
2785 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2786 // strtab holding the name.
2787
2788 template<int size, bool big_endian>
2789 void
2790 Symbol_table::sized_write_symbol(
2791 Sized_symbol<size>* sym,
2792 typename elfcpp::Elf_types<size>::Elf_Addr value,
2793 unsigned int shndx,
2794 const Stringpool* pool,
2795 unsigned char* p) const
2796 {
2797 elfcpp::Sym_write<size, big_endian> osym(p);
2798 osym.put_st_name(pool->get_offset(sym->name()));
2799 osym.put_st_value(value);
2800 // Use a symbol size of zero for undefined symbols from shared libraries.
2801 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2802 osym.put_st_size(0);
2803 else
2804 osym.put_st_size(sym->symsize());
2805 // A version script may have overridden the default binding.
2806 if (sym->is_forced_local())
2807 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2808 else
2809 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2810 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2811 osym.put_st_shndx(shndx);
2812 }
2813
2814 // Check for unresolved symbols in shared libraries. This is
2815 // controlled by the --allow-shlib-undefined option.
2816
2817 // We only warn about libraries for which we have seen all the
2818 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2819 // which were not seen in this link. If we didn't see a DT_NEEDED
2820 // entry, we aren't going to be able to reliably report whether the
2821 // symbol is undefined.
2822
2823 // We also don't warn about libraries found in a system library
2824 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2825 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2826 // can have undefined references satisfied by ld-linux.so.
2827
2828 inline void
2829 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2830 {
2831 bool dummy;
2832 if (sym->source() == Symbol::FROM_OBJECT
2833 && sym->object()->is_dynamic()
2834 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2835 && sym->binding() != elfcpp::STB_WEAK
2836 && !parameters->options().allow_shlib_undefined()
2837 && !parameters->target().is_defined_by_abi(sym)
2838 && !sym->object()->is_in_system_directory())
2839 {
2840 // A very ugly cast.
2841 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2842 if (!dynobj->has_unknown_needed_entries())
2843 gold_undefined_symbol(sym);
2844 }
2845 }
2846
2847 // Write out a section symbol. Return the update offset.
2848
2849 void
2850 Symbol_table::write_section_symbol(const Output_section *os,
2851 Output_symtab_xindex* symtab_xindex,
2852 Output_file* of,
2853 off_t offset) const
2854 {
2855 switch (parameters->size_and_endianness())
2856 {
2857 #ifdef HAVE_TARGET_32_LITTLE
2858 case Parameters::TARGET_32_LITTLE:
2859 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2860 offset);
2861 break;
2862 #endif
2863 #ifdef HAVE_TARGET_32_BIG
2864 case Parameters::TARGET_32_BIG:
2865 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2866 offset);
2867 break;
2868 #endif
2869 #ifdef HAVE_TARGET_64_LITTLE
2870 case Parameters::TARGET_64_LITTLE:
2871 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2872 offset);
2873 break;
2874 #endif
2875 #ifdef HAVE_TARGET_64_BIG
2876 case Parameters::TARGET_64_BIG:
2877 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2878 offset);
2879 break;
2880 #endif
2881 default:
2882 gold_unreachable();
2883 }
2884 }
2885
2886 // Write out a section symbol, specialized for size and endianness.
2887
2888 template<int size, bool big_endian>
2889 void
2890 Symbol_table::sized_write_section_symbol(const Output_section* os,
2891 Output_symtab_xindex* symtab_xindex,
2892 Output_file* of,
2893 off_t offset) const
2894 {
2895 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2896
2897 unsigned char* pov = of->get_output_view(offset, sym_size);
2898
2899 elfcpp::Sym_write<size, big_endian> osym(pov);
2900 osym.put_st_name(0);
2901 if (parameters->options().relocatable())
2902 osym.put_st_value(0);
2903 else
2904 osym.put_st_value(os->address());
2905 osym.put_st_size(0);
2906 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2907 elfcpp::STT_SECTION));
2908 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2909
2910 unsigned int shndx = os->out_shndx();
2911 if (shndx >= elfcpp::SHN_LORESERVE)
2912 {
2913 symtab_xindex->add(os->symtab_index(), shndx);
2914 shndx = elfcpp::SHN_XINDEX;
2915 }
2916 osym.put_st_shndx(shndx);
2917
2918 of->write_output_view(offset, sym_size, pov);
2919 }
2920
2921 // Print statistical information to stderr. This is used for --stats.
2922
2923 void
2924 Symbol_table::print_stats() const
2925 {
2926 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2927 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2928 program_name, this->table_.size(), this->table_.bucket_count());
2929 #else
2930 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2931 program_name, this->table_.size());
2932 #endif
2933 this->namepool_.print_stats("symbol table stringpool");
2934 }
2935
2936 // We check for ODR violations by looking for symbols with the same
2937 // name for which the debugging information reports that they were
2938 // defined in different source locations. When comparing the source
2939 // location, we consider instances with the same base filename and
2940 // line number to be the same. This is because different object
2941 // files/shared libraries can include the same header file using
2942 // different paths, and we don't want to report an ODR violation in
2943 // that case.
2944
2945 // This struct is used to compare line information, as returned by
2946 // Dwarf_line_info::one_addr2line. It implements a < comparison
2947 // operator used with std::set.
2948
2949 struct Odr_violation_compare
2950 {
2951 bool
2952 operator()(const std::string& s1, const std::string& s2) const
2953 {
2954 std::string::size_type pos1 = s1.rfind('/');
2955 std::string::size_type pos2 = s2.rfind('/');
2956 if (pos1 == std::string::npos
2957 || pos2 == std::string::npos)
2958 return s1 < s2;
2959 return s1.compare(pos1, std::string::npos,
2960 s2, pos2, std::string::npos) < 0;
2961 }
2962 };
2963
2964 // Check candidate_odr_violations_ to find symbols with the same name
2965 // but apparently different definitions (different source-file/line-no).
2966
2967 void
2968 Symbol_table::detect_odr_violations(const Task* task,
2969 const char* output_file_name) const
2970 {
2971 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2972 it != candidate_odr_violations_.end();
2973 ++it)
2974 {
2975 const char* symbol_name = it->first;
2976 // We use a sorted set so the output is deterministic.
2977 std::set<std::string, Odr_violation_compare> line_nums;
2978
2979 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2980 locs = it->second.begin();
2981 locs != it->second.end();
2982 ++locs)
2983 {
2984 // We need to lock the object in order to read it. This
2985 // means that we have to run in a singleton Task. If we
2986 // want to run this in a general Task for better
2987 // performance, we will need one Task for object, plus
2988 // appropriate locking to ensure that we don't conflict with
2989 // other uses of the object. Also note, one_addr2line is not
2990 // currently thread-safe.
2991 Task_lock_obj<Object> tl(task, locs->object);
2992 // 16 is the size of the object-cache that one_addr2line should use.
2993 std::string lineno = Dwarf_line_info::one_addr2line(
2994 locs->object, locs->shndx, locs->offset, 16);
2995 if (!lineno.empty())
2996 line_nums.insert(lineno);
2997 }
2998
2999 if (line_nums.size() > 1)
3000 {
3001 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3002 "places (possible ODR violation):"),
3003 output_file_name, demangle(symbol_name).c_str());
3004 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
3005 it2 != line_nums.end();
3006 ++it2)
3007 fprintf(stderr, " %s\n", it2->c_str());
3008 }
3009 }
3010 // We only call one_addr2line() in this function, so we can clear its cache.
3011 Dwarf_line_info::clear_addr2line_cache();
3012 }
3013
3014 // Warnings functions.
3015
3016 // Add a new warning.
3017
3018 void
3019 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3020 const std::string& warning)
3021 {
3022 name = symtab->canonicalize_name(name);
3023 this->warnings_[name].set(obj, warning);
3024 }
3025
3026 // Look through the warnings and mark the symbols for which we should
3027 // warn. This is called during Layout::finalize when we know the
3028 // sources for all the symbols.
3029
3030 void
3031 Warnings::note_warnings(Symbol_table* symtab)
3032 {
3033 for (Warning_table::iterator p = this->warnings_.begin();
3034 p != this->warnings_.end();
3035 ++p)
3036 {
3037 Symbol* sym = symtab->lookup(p->first, NULL);
3038 if (sym != NULL
3039 && sym->source() == Symbol::FROM_OBJECT
3040 && sym->object() == p->second.object)
3041 sym->set_has_warning();
3042 }
3043 }
3044
3045 // Issue a warning. This is called when we see a relocation against a
3046 // symbol for which has a warning.
3047
3048 template<int size, bool big_endian>
3049 void
3050 Warnings::issue_warning(const Symbol* sym,
3051 const Relocate_info<size, big_endian>* relinfo,
3052 size_t relnum, off_t reloffset) const
3053 {
3054 gold_assert(sym->has_warning());
3055 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3056 gold_assert(p != this->warnings_.end());
3057 gold_warning_at_location(relinfo, relnum, reloffset,
3058 "%s", p->second.text.c_str());
3059 }
3060
3061 // Instantiate the templates we need. We could use the configure
3062 // script to restrict this to only the ones needed for implemented
3063 // targets.
3064
3065 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3066 template
3067 void
3068 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3069 #endif
3070
3071 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3072 template
3073 void
3074 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3075 #endif
3076
3077 #ifdef HAVE_TARGET_32_LITTLE
3078 template
3079 void
3080 Symbol_table::add_from_relobj<32, false>(
3081 Sized_relobj<32, false>* relobj,
3082 const unsigned char* syms,
3083 size_t count,
3084 size_t symndx_offset,
3085 const char* sym_names,
3086 size_t sym_name_size,
3087 Sized_relobj<32, false>::Symbols* sympointers,
3088 size_t* defined);
3089 #endif
3090
3091 #ifdef HAVE_TARGET_32_BIG
3092 template
3093 void
3094 Symbol_table::add_from_relobj<32, true>(
3095 Sized_relobj<32, true>* relobj,
3096 const unsigned char* syms,
3097 size_t count,
3098 size_t symndx_offset,
3099 const char* sym_names,
3100 size_t sym_name_size,
3101 Sized_relobj<32, true>::Symbols* sympointers,
3102 size_t* defined);
3103 #endif
3104
3105 #ifdef HAVE_TARGET_64_LITTLE
3106 template
3107 void
3108 Symbol_table::add_from_relobj<64, false>(
3109 Sized_relobj<64, false>* relobj,
3110 const unsigned char* syms,
3111 size_t count,
3112 size_t symndx_offset,
3113 const char* sym_names,
3114 size_t sym_name_size,
3115 Sized_relobj<64, false>::Symbols* sympointers,
3116 size_t* defined);
3117 #endif
3118
3119 #ifdef HAVE_TARGET_64_BIG
3120 template
3121 void
3122 Symbol_table::add_from_relobj<64, true>(
3123 Sized_relobj<64, true>* relobj,
3124 const unsigned char* syms,
3125 size_t count,
3126 size_t symndx_offset,
3127 const char* sym_names,
3128 size_t sym_name_size,
3129 Sized_relobj<64, true>::Symbols* sympointers,
3130 size_t* defined);
3131 #endif
3132
3133 #ifdef HAVE_TARGET_32_LITTLE
3134 template
3135 Symbol*
3136 Symbol_table::add_from_pluginobj<32, false>(
3137 Sized_pluginobj<32, false>* obj,
3138 const char* name,
3139 const char* ver,
3140 elfcpp::Sym<32, false>* sym);
3141 #endif
3142
3143 #ifdef HAVE_TARGET_32_BIG
3144 template
3145 Symbol*
3146 Symbol_table::add_from_pluginobj<32, true>(
3147 Sized_pluginobj<32, true>* obj,
3148 const char* name,
3149 const char* ver,
3150 elfcpp::Sym<32, true>* sym);
3151 #endif
3152
3153 #ifdef HAVE_TARGET_64_LITTLE
3154 template
3155 Symbol*
3156 Symbol_table::add_from_pluginobj<64, false>(
3157 Sized_pluginobj<64, false>* obj,
3158 const char* name,
3159 const char* ver,
3160 elfcpp::Sym<64, false>* sym);
3161 #endif
3162
3163 #ifdef HAVE_TARGET_64_BIG
3164 template
3165 Symbol*
3166 Symbol_table::add_from_pluginobj<64, true>(
3167 Sized_pluginobj<64, true>* obj,
3168 const char* name,
3169 const char* ver,
3170 elfcpp::Sym<64, true>* sym);
3171 #endif
3172
3173 #ifdef HAVE_TARGET_32_LITTLE
3174 template
3175 void
3176 Symbol_table::add_from_dynobj<32, false>(
3177 Sized_dynobj<32, false>* dynobj,
3178 const unsigned char* syms,
3179 size_t count,
3180 const char* sym_names,
3181 size_t sym_name_size,
3182 const unsigned char* versym,
3183 size_t versym_size,
3184 const std::vector<const char*>* version_map,
3185 Sized_relobj<32, false>::Symbols* sympointers,
3186 size_t* defined);
3187 #endif
3188
3189 #ifdef HAVE_TARGET_32_BIG
3190 template
3191 void
3192 Symbol_table::add_from_dynobj<32, true>(
3193 Sized_dynobj<32, true>* dynobj,
3194 const unsigned char* syms,
3195 size_t count,
3196 const char* sym_names,
3197 size_t sym_name_size,
3198 const unsigned char* versym,
3199 size_t versym_size,
3200 const std::vector<const char*>* version_map,
3201 Sized_relobj<32, true>::Symbols* sympointers,
3202 size_t* defined);
3203 #endif
3204
3205 #ifdef HAVE_TARGET_64_LITTLE
3206 template
3207 void
3208 Symbol_table::add_from_dynobj<64, false>(
3209 Sized_dynobj<64, false>* dynobj,
3210 const unsigned char* syms,
3211 size_t count,
3212 const char* sym_names,
3213 size_t sym_name_size,
3214 const unsigned char* versym,
3215 size_t versym_size,
3216 const std::vector<const char*>* version_map,
3217 Sized_relobj<64, false>::Symbols* sympointers,
3218 size_t* defined);
3219 #endif
3220
3221 #ifdef HAVE_TARGET_64_BIG
3222 template
3223 void
3224 Symbol_table::add_from_dynobj<64, true>(
3225 Sized_dynobj<64, true>* dynobj,
3226 const unsigned char* syms,
3227 size_t count,
3228 const char* sym_names,
3229 size_t sym_name_size,
3230 const unsigned char* versym,
3231 size_t versym_size,
3232 const std::vector<const char*>* version_map,
3233 Sized_relobj<64, true>::Symbols* sympointers,
3234 size_t* defined);
3235 #endif
3236
3237 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3238 template
3239 void
3240 Symbol_table::define_with_copy_reloc<32>(
3241 Sized_symbol<32>* sym,
3242 Output_data* posd,
3243 elfcpp::Elf_types<32>::Elf_Addr value);
3244 #endif
3245
3246 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3247 template
3248 void
3249 Symbol_table::define_with_copy_reloc<64>(
3250 Sized_symbol<64>* sym,
3251 Output_data* posd,
3252 elfcpp::Elf_types<64>::Elf_Addr value);
3253 #endif
3254
3255 #ifdef HAVE_TARGET_32_LITTLE
3256 template
3257 void
3258 Warnings::issue_warning<32, false>(const Symbol* sym,
3259 const Relocate_info<32, false>* relinfo,
3260 size_t relnum, off_t reloffset) const;
3261 #endif
3262
3263 #ifdef HAVE_TARGET_32_BIG
3264 template
3265 void
3266 Warnings::issue_warning<32, true>(const Symbol* sym,
3267 const Relocate_info<32, true>* relinfo,
3268 size_t relnum, off_t reloffset) const;
3269 #endif
3270
3271 #ifdef HAVE_TARGET_64_LITTLE
3272 template
3273 void
3274 Warnings::issue_warning<64, false>(const Symbol* sym,
3275 const Relocate_info<64, false>* relinfo,
3276 size_t relnum, off_t reloffset) const;
3277 #endif
3278
3279 #ifdef HAVE_TARGET_64_BIG
3280 template
3281 void
3282 Warnings::issue_warning<64, true>(const Symbol* sym,
3283 const Relocate_info<64, true>* relinfo,
3284 size_t relnum, off_t reloffset) const;
3285 #endif
3286
3287 } // End namespace gold.
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