PR 11108
[deliverable/binutils-gdb.git] / gold / symtab.cc
1 // symtab.cc -- the gold symbol table
2
3 // Copyright 2006, 2007, 2008, 2009, 2010 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_ = -1U;
63 this->type_ = type;
64 this->binding_ = binding;
65 this->visibility_ = visibility;
66 this->nonvis_ = nonvis;
67 this->is_def_ = false;
68 this->is_forwarder_ = false;
69 this->has_alias_ = false;
70 this->needs_dynsym_entry_ = false;
71 this->in_reg_ = false;
72 this->in_dyn_ = false;
73 this->has_warning_ = false;
74 this->is_copied_from_dynobj_ = false;
75 this->is_forced_local_ = false;
76 this->is_ordinary_shndx_ = false;
77 this->in_real_elf_ = false;
78 this->is_defined_in_discarded_section_ = false;
79 }
80
81 // Return the demangled version of the symbol's name, but only
82 // if the --demangle flag was set.
83
84 static std::string
85 demangle(const char* name)
86 {
87 if (!parameters->options().do_demangle())
88 return name;
89
90 // cplus_demangle allocates memory for the result it returns,
91 // and returns NULL if the name is already demangled.
92 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
93 if (demangled_name == NULL)
94 return name;
95
96 std::string retval(demangled_name);
97 free(demangled_name);
98 return retval;
99 }
100
101 std::string
102 Symbol::demangled_name() const
103 {
104 return demangle(this->name());
105 }
106
107 // Initialize the fields in the base class Symbol for SYM in OBJECT.
108
109 template<int size, bool big_endian>
110 void
111 Symbol::init_base_object(const char* name, const char* version, Object* object,
112 const elfcpp::Sym<size, big_endian>& sym,
113 unsigned int st_shndx, bool is_ordinary)
114 {
115 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
116 sym.get_st_visibility(), sym.get_st_nonvis());
117 this->u_.from_object.object = object;
118 this->u_.from_object.shndx = st_shndx;
119 this->is_ordinary_shndx_ = is_ordinary;
120 this->source_ = FROM_OBJECT;
121 this->in_reg_ = !object->is_dynamic();
122 this->in_dyn_ = object->is_dynamic();
123 this->in_real_elf_ = object->pluginobj() == NULL;
124 }
125
126 // Initialize the fields in the base class Symbol for a symbol defined
127 // in an Output_data.
128
129 void
130 Symbol::init_base_output_data(const char* name, const char* version,
131 Output_data* od, elfcpp::STT type,
132 elfcpp::STB binding, elfcpp::STV visibility,
133 unsigned char nonvis, bool offset_is_from_end)
134 {
135 this->init_fields(name, version, type, binding, visibility, nonvis);
136 this->u_.in_output_data.output_data = od;
137 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
138 this->source_ = IN_OUTPUT_DATA;
139 this->in_reg_ = true;
140 this->in_real_elf_ = true;
141 }
142
143 // Initialize the fields in the base class Symbol for a symbol defined
144 // in an Output_segment.
145
146 void
147 Symbol::init_base_output_segment(const char* name, const char* version,
148 Output_segment* os, elfcpp::STT type,
149 elfcpp::STB binding, elfcpp::STV visibility,
150 unsigned char nonvis,
151 Segment_offset_base offset_base)
152 {
153 this->init_fields(name, version, type, binding, visibility, nonvis);
154 this->u_.in_output_segment.output_segment = os;
155 this->u_.in_output_segment.offset_base = offset_base;
156 this->source_ = IN_OUTPUT_SEGMENT;
157 this->in_reg_ = true;
158 this->in_real_elf_ = true;
159 }
160
161 // Initialize the fields in the base class Symbol for a symbol defined
162 // as a constant.
163
164 void
165 Symbol::init_base_constant(const char* name, const char* version,
166 elfcpp::STT type, elfcpp::STB binding,
167 elfcpp::STV visibility, unsigned char nonvis)
168 {
169 this->init_fields(name, version, type, binding, visibility, nonvis);
170 this->source_ = IS_CONSTANT;
171 this->in_reg_ = true;
172 this->in_real_elf_ = true;
173 }
174
175 // Initialize the fields in the base class Symbol for an undefined
176 // symbol.
177
178 void
179 Symbol::init_base_undefined(const char* name, const char* version,
180 elfcpp::STT type, elfcpp::STB binding,
181 elfcpp::STV visibility, unsigned char nonvis)
182 {
183 this->init_fields(name, version, type, binding, visibility, nonvis);
184 this->dynsym_index_ = -1U;
185 this->source_ = IS_UNDEFINED;
186 this->in_reg_ = true;
187 this->in_real_elf_ = true;
188 }
189
190 // Allocate a common symbol in the base.
191
192 void
193 Symbol::allocate_base_common(Output_data* od)
194 {
195 gold_assert(this->is_common());
196 this->source_ = IN_OUTPUT_DATA;
197 this->u_.in_output_data.output_data = od;
198 this->u_.in_output_data.offset_is_from_end = false;
199 }
200
201 // Initialize the fields in Sized_symbol for SYM in OBJECT.
202
203 template<int size>
204 template<bool big_endian>
205 void
206 Sized_symbol<size>::init_object(const char* name, const char* version,
207 Object* object,
208 const elfcpp::Sym<size, big_endian>& sym,
209 unsigned int st_shndx, bool is_ordinary)
210 {
211 this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
212 this->value_ = sym.get_st_value();
213 this->symsize_ = sym.get_st_size();
214 }
215
216 // Initialize the fields in Sized_symbol for a symbol defined in an
217 // Output_data.
218
219 template<int size>
220 void
221 Sized_symbol<size>::init_output_data(const char* name, const char* version,
222 Output_data* od, Value_type value,
223 Size_type symsize, elfcpp::STT type,
224 elfcpp::STB binding,
225 elfcpp::STV visibility,
226 unsigned char nonvis,
227 bool offset_is_from_end)
228 {
229 this->init_base_output_data(name, version, od, type, binding, visibility,
230 nonvis, offset_is_from_end);
231 this->value_ = value;
232 this->symsize_ = symsize;
233 }
234
235 // Initialize the fields in Sized_symbol for a symbol defined in an
236 // Output_segment.
237
238 template<int size>
239 void
240 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
241 Output_segment* os, Value_type value,
242 Size_type symsize, elfcpp::STT type,
243 elfcpp::STB binding,
244 elfcpp::STV visibility,
245 unsigned char nonvis,
246 Segment_offset_base offset_base)
247 {
248 this->init_base_output_segment(name, version, os, type, binding, visibility,
249 nonvis, offset_base);
250 this->value_ = value;
251 this->symsize_ = symsize;
252 }
253
254 // Initialize the fields in Sized_symbol for a symbol defined as a
255 // constant.
256
257 template<int size>
258 void
259 Sized_symbol<size>::init_constant(const char* name, const char* version,
260 Value_type value, Size_type symsize,
261 elfcpp::STT type, elfcpp::STB binding,
262 elfcpp::STV visibility, unsigned char nonvis)
263 {
264 this->init_base_constant(name, version, type, binding, visibility, nonvis);
265 this->value_ = value;
266 this->symsize_ = symsize;
267 }
268
269 // Initialize the fields in Sized_symbol for an undefined symbol.
270
271 template<int size>
272 void
273 Sized_symbol<size>::init_undefined(const char* name, const char* version,
274 elfcpp::STT type, elfcpp::STB binding,
275 elfcpp::STV visibility, unsigned char nonvis)
276 {
277 this->init_base_undefined(name, version, type, binding, visibility, nonvis);
278 this->value_ = 0;
279 this->symsize_ = 0;
280 }
281
282 // Return true if SHNDX represents a common symbol.
283
284 bool
285 Symbol::is_common_shndx(unsigned int shndx)
286 {
287 return (shndx == elfcpp::SHN_COMMON
288 || shndx == parameters->target().small_common_shndx()
289 || shndx == parameters->target().large_common_shndx());
290 }
291
292 // Allocate a common symbol.
293
294 template<int size>
295 void
296 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
297 {
298 this->allocate_base_common(od);
299 this->value_ = value;
300 }
301
302 // The ""'s around str ensure str is a string literal, so sizeof works.
303 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
304
305 // Return true if this symbol should be added to the dynamic symbol
306 // table.
307
308 inline bool
309 Symbol::should_add_dynsym_entry() const
310 {
311 // If the symbol is used by a dynamic relocation, we need to add it.
312 if (this->needs_dynsym_entry())
313 return true;
314
315 // If this symbol's section is not added, the symbol need not be added.
316 // The section may have been GCed. Note that export_dynamic is being
317 // overridden here. This should not be done for shared objects.
318 if (parameters->options().gc_sections()
319 && !parameters->options().shared()
320 && this->source() == Symbol::FROM_OBJECT
321 && !this->object()->is_dynamic())
322 {
323 Relobj* relobj = static_cast<Relobj*>(this->object());
324 bool is_ordinary;
325 unsigned int shndx = this->shndx(&is_ordinary);
326 if (is_ordinary && shndx != elfcpp::SHN_UNDEF
327 && !relobj->is_section_included(shndx))
328 return false;
329 }
330
331 // If the symbol was forced local in a version script, do not add it.
332 if (this->is_forced_local())
333 return false;
334
335 // If the symbol was forced dynamic in a --dynamic-list file, add it.
336 if (parameters->options().in_dynamic_list(this->name()))
337 return true;
338
339 // If dynamic-list-data was specified, add any STT_OBJECT.
340 if (parameters->options().dynamic_list_data()
341 && !this->is_from_dynobj()
342 && this->type() == elfcpp::STT_OBJECT)
343 return true;
344
345 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
346 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
347 if ((parameters->options().dynamic_list_cpp_new()
348 || parameters->options().dynamic_list_cpp_typeinfo())
349 && !this->is_from_dynobj())
350 {
351 // TODO(csilvers): We could probably figure out if we're an operator
352 // new/delete or typeinfo without the need to demangle.
353 char* demangled_name = cplus_demangle(this->name(),
354 DMGL_ANSI | DMGL_PARAMS);
355 if (demangled_name == NULL)
356 {
357 // Not a C++ symbol, so it can't satisfy these flags
358 }
359 else if (parameters->options().dynamic_list_cpp_new()
360 && (strprefix(demangled_name, "operator new")
361 || strprefix(demangled_name, "operator delete")))
362 {
363 free(demangled_name);
364 return true;
365 }
366 else if (parameters->options().dynamic_list_cpp_typeinfo()
367 && (strprefix(demangled_name, "typeinfo name for")
368 || strprefix(demangled_name, "typeinfo for")))
369 {
370 free(demangled_name);
371 return true;
372 }
373 else
374 free(demangled_name);
375 }
376
377 // If exporting all symbols or building a shared library,
378 // and the symbol is defined in a regular object and is
379 // externally visible, we need to add it.
380 if ((parameters->options().export_dynamic() || parameters->options().shared())
381 && !this->is_from_dynobj()
382 && this->is_externally_visible())
383 return true;
384
385 return false;
386 }
387
388 // Return true if the final value of this symbol is known at link
389 // time.
390
391 bool
392 Symbol::final_value_is_known() const
393 {
394 // If we are not generating an executable, then no final values are
395 // known, since they will change at runtime.
396 if (parameters->options().output_is_position_independent()
397 || parameters->options().relocatable())
398 return false;
399
400 // If the symbol is not from an object file, and is not undefined,
401 // then it is defined, and known.
402 if (this->source_ != FROM_OBJECT)
403 {
404 if (this->source_ != IS_UNDEFINED)
405 return true;
406 }
407 else
408 {
409 // If the symbol is from a dynamic object, then the final value
410 // is not known.
411 if (this->object()->is_dynamic())
412 return false;
413
414 // If the symbol is not undefined (it is defined or common),
415 // then the final value is known.
416 if (!this->is_undefined())
417 return true;
418 }
419
420 // If the symbol is undefined, then whether the final value is known
421 // depends on whether we are doing a static link. If we are doing a
422 // dynamic link, then the final value could be filled in at runtime.
423 // This could reasonably be the case for a weak undefined symbol.
424 return parameters->doing_static_link();
425 }
426
427 // Return the output section where this symbol is defined.
428
429 Output_section*
430 Symbol::output_section() const
431 {
432 switch (this->source_)
433 {
434 case FROM_OBJECT:
435 {
436 unsigned int shndx = this->u_.from_object.shndx;
437 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
438 {
439 gold_assert(!this->u_.from_object.object->is_dynamic());
440 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
441 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
442 return relobj->output_section(shndx);
443 }
444 return NULL;
445 }
446
447 case IN_OUTPUT_DATA:
448 return this->u_.in_output_data.output_data->output_section();
449
450 case IN_OUTPUT_SEGMENT:
451 case IS_CONSTANT:
452 case IS_UNDEFINED:
453 return NULL;
454
455 default:
456 gold_unreachable();
457 }
458 }
459
460 // Set the symbol's output section. This is used for symbols defined
461 // in scripts. This should only be called after the symbol table has
462 // been finalized.
463
464 void
465 Symbol::set_output_section(Output_section* os)
466 {
467 switch (this->source_)
468 {
469 case FROM_OBJECT:
470 case IN_OUTPUT_DATA:
471 gold_assert(this->output_section() == os);
472 break;
473 case IS_CONSTANT:
474 this->source_ = IN_OUTPUT_DATA;
475 this->u_.in_output_data.output_data = os;
476 this->u_.in_output_data.offset_is_from_end = false;
477 break;
478 case IN_OUTPUT_SEGMENT:
479 case IS_UNDEFINED:
480 default:
481 gold_unreachable();
482 }
483 }
484
485 // Class Symbol_table.
486
487 Symbol_table::Symbol_table(unsigned int count,
488 const Version_script_info& version_script)
489 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
490 forwarders_(), commons_(), tls_commons_(), small_commons_(),
491 large_commons_(), forced_locals_(), warnings_(),
492 version_script_(version_script), gc_(NULL), icf_(NULL)
493 {
494 namepool_.reserve(count);
495 }
496
497 Symbol_table::~Symbol_table()
498 {
499 }
500
501 // The hash function. The key values are Stringpool keys.
502
503 inline size_t
504 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
505 {
506 return key.first ^ key.second;
507 }
508
509 // The symbol table key equality function. This is called with
510 // Stringpool keys.
511
512 inline bool
513 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
514 const Symbol_table_key& k2) const
515 {
516 return k1.first == k2.first && k1.second == k2.second;
517 }
518
519 bool
520 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
521 {
522 return (parameters->options().icf_enabled()
523 && this->icf_->is_section_folded(obj, shndx));
524 }
525
526 // For symbols that have been listed with -u option, add them to the
527 // work list to avoid gc'ing them.
528
529 void
530 Symbol_table::gc_mark_undef_symbols()
531 {
532 for (options::String_set::const_iterator p =
533 parameters->options().undefined_begin();
534 p != parameters->options().undefined_end();
535 ++p)
536 {
537 const char* name = p->c_str();
538 Symbol* sym = this->lookup(name);
539 gold_assert (sym != NULL);
540 if (sym->source() == Symbol::FROM_OBJECT
541 && !sym->object()->is_dynamic())
542 {
543 Relobj* obj = static_cast<Relobj*>(sym->object());
544 bool is_ordinary;
545 unsigned int shndx = sym->shndx(&is_ordinary);
546 if (is_ordinary)
547 {
548 gold_assert(this->gc_ != NULL);
549 this->gc_->worklist().push(Section_id(obj, shndx));
550 }
551 }
552 }
553 }
554
555 void
556 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
557 {
558 if (!sym->is_from_dynobj()
559 && sym->is_externally_visible())
560 {
561 //Add the object and section to the work list.
562 Relobj* obj = static_cast<Relobj*>(sym->object());
563 bool is_ordinary;
564 unsigned int shndx = sym->shndx(&is_ordinary);
565 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
566 {
567 gold_assert(this->gc_!= NULL);
568 this->gc_->worklist().push(Section_id(obj, shndx));
569 }
570 }
571 }
572
573 // When doing garbage collection, keep symbols that have been seen in
574 // dynamic objects.
575 inline void
576 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
577 {
578 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
579 && !sym->object()->is_dynamic())
580 {
581 Relobj *obj = static_cast<Relobj*>(sym->object());
582 bool is_ordinary;
583 unsigned int shndx = sym->shndx(&is_ordinary);
584 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
585 {
586 gold_assert(this->gc_ != NULL);
587 this->gc_->worklist().push(Section_id(obj, shndx));
588 }
589 }
590 }
591
592 // Make TO a symbol which forwards to FROM.
593
594 void
595 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
596 {
597 gold_assert(from != to);
598 gold_assert(!from->is_forwarder() && !to->is_forwarder());
599 this->forwarders_[from] = to;
600 from->set_forwarder();
601 }
602
603 // Resolve the forwards from FROM, returning the real symbol.
604
605 Symbol*
606 Symbol_table::resolve_forwards(const Symbol* from) const
607 {
608 gold_assert(from->is_forwarder());
609 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
610 this->forwarders_.find(from);
611 gold_assert(p != this->forwarders_.end());
612 return p->second;
613 }
614
615 // Look up a symbol by name.
616
617 Symbol*
618 Symbol_table::lookup(const char* name, const char* version) const
619 {
620 Stringpool::Key name_key;
621 name = this->namepool_.find(name, &name_key);
622 if (name == NULL)
623 return NULL;
624
625 Stringpool::Key version_key = 0;
626 if (version != NULL)
627 {
628 version = this->namepool_.find(version, &version_key);
629 if (version == NULL)
630 return NULL;
631 }
632
633 Symbol_table_key key(name_key, version_key);
634 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
635 if (p == this->table_.end())
636 return NULL;
637 return p->second;
638 }
639
640 // Resolve a Symbol with another Symbol. This is only used in the
641 // unusual case where there are references to both an unversioned
642 // symbol and a symbol with a version, and we then discover that that
643 // version is the default version. Because this is unusual, we do
644 // this the slow way, by converting back to an ELF symbol.
645
646 template<int size, bool big_endian>
647 void
648 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
649 {
650 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
651 elfcpp::Sym_write<size, big_endian> esym(buf);
652 // We don't bother to set the st_name or the st_shndx field.
653 esym.put_st_value(from->value());
654 esym.put_st_size(from->symsize());
655 esym.put_st_info(from->binding(), from->type());
656 esym.put_st_other(from->visibility(), from->nonvis());
657 bool is_ordinary;
658 unsigned int shndx = from->shndx(&is_ordinary);
659 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
660 from->version());
661 if (from->in_reg())
662 to->set_in_reg();
663 if (from->in_dyn())
664 to->set_in_dyn();
665 if (parameters->options().gc_sections())
666 this->gc_mark_dyn_syms(to);
667 }
668
669 // Record that a symbol is forced to be local by a version script or
670 // by visibility.
671
672 void
673 Symbol_table::force_local(Symbol* sym)
674 {
675 if (!sym->is_defined() && !sym->is_common())
676 return;
677 if (sym->is_forced_local())
678 {
679 // We already got this one.
680 return;
681 }
682 sym->set_is_forced_local();
683 this->forced_locals_.push_back(sym);
684 }
685
686 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
687 // is only called for undefined symbols, when at least one --wrap
688 // option was used.
689
690 const char*
691 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
692 {
693 // For some targets, we need to ignore a specific character when
694 // wrapping, and add it back later.
695 char prefix = '\0';
696 if (name[0] == parameters->target().wrap_char())
697 {
698 prefix = name[0];
699 ++name;
700 }
701
702 if (parameters->options().is_wrap(name))
703 {
704 // Turn NAME into __wrap_NAME.
705 std::string s;
706 if (prefix != '\0')
707 s += prefix;
708 s += "__wrap_";
709 s += name;
710
711 // This will give us both the old and new name in NAMEPOOL_, but
712 // that is OK. Only the versions we need will wind up in the
713 // real string table in the output file.
714 return this->namepool_.add(s.c_str(), true, name_key);
715 }
716
717 const char* const real_prefix = "__real_";
718 const size_t real_prefix_length = strlen(real_prefix);
719 if (strncmp(name, real_prefix, real_prefix_length) == 0
720 && parameters->options().is_wrap(name + real_prefix_length))
721 {
722 // Turn __real_NAME into NAME.
723 std::string s;
724 if (prefix != '\0')
725 s += prefix;
726 s += name + real_prefix_length;
727 return this->namepool_.add(s.c_str(), true, name_key);
728 }
729
730 return name;
731 }
732
733 // This is called when we see a symbol NAME/VERSION, and the symbol
734 // already exists in the symbol table, and VERSION is marked as being
735 // the default version. SYM is the NAME/VERSION symbol we just added.
736 // DEFAULT_IS_NEW is true if this is the first time we have seen the
737 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
738
739 template<int size, bool big_endian>
740 void
741 Symbol_table::define_default_version(Sized_symbol<size>* sym,
742 bool default_is_new,
743 Symbol_table_type::iterator pdef)
744 {
745 if (default_is_new)
746 {
747 // This is the first time we have seen NAME/NULL. Make
748 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
749 // version.
750 pdef->second = sym;
751 sym->set_is_default();
752 }
753 else if (pdef->second == sym)
754 {
755 // NAME/NULL already points to NAME/VERSION. Don't mark the
756 // symbol as the default if it is not already the default.
757 }
758 else
759 {
760 // This is the unfortunate case where we already have entries
761 // for both NAME/VERSION and NAME/NULL. We now see a symbol
762 // NAME/VERSION where VERSION is the default version. We have
763 // already resolved this new symbol with the existing
764 // NAME/VERSION symbol.
765
766 // It's possible that NAME/NULL and NAME/VERSION are both
767 // defined in regular objects. This can only happen if one
768 // object file defines foo and another defines foo@@ver. This
769 // is somewhat obscure, but we call it a multiple definition
770 // error.
771
772 // It's possible that NAME/NULL actually has a version, in which
773 // case it won't be the same as VERSION. This happens with
774 // ver_test_7.so in the testsuite for the symbol t2_2. We see
775 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
776 // then see an unadorned t2_2 in an object file and give it
777 // version VER1 from the version script. This looks like a
778 // default definition for VER1, so it looks like we should merge
779 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
780 // not obvious that this is an error, either. So we just punt.
781
782 // If one of the symbols has non-default visibility, and the
783 // other is defined in a shared object, then they are different
784 // symbols.
785
786 // Otherwise, we just resolve the symbols as though they were
787 // the same.
788
789 if (pdef->second->version() != NULL)
790 gold_assert(pdef->second->version() != sym->version());
791 else if (sym->visibility() != elfcpp::STV_DEFAULT
792 && pdef->second->is_from_dynobj())
793 ;
794 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
795 && sym->is_from_dynobj())
796 ;
797 else
798 {
799 const Sized_symbol<size>* symdef;
800 symdef = this->get_sized_symbol<size>(pdef->second);
801 Symbol_table::resolve<size, big_endian>(sym, symdef);
802 this->make_forwarder(pdef->second, sym);
803 pdef->second = sym;
804 sym->set_is_default();
805 }
806 }
807 }
808
809 // Add one symbol from OBJECT to the symbol table. NAME is symbol
810 // name and VERSION is the version; both are canonicalized. DEF is
811 // whether this is the default version. ST_SHNDX is the symbol's
812 // section index; IS_ORDINARY is whether this is a normal section
813 // rather than a special code.
814
815 // If IS_DEFAULT_VERSION is true, then this is the definition of a
816 // default version of a symbol. That means that any lookup of
817 // NAME/NULL and any lookup of NAME/VERSION should always return the
818 // same symbol. This is obvious for references, but in particular we
819 // want to do this for definitions: overriding NAME/NULL should also
820 // override NAME/VERSION. If we don't do that, it would be very hard
821 // to override functions in a shared library which uses versioning.
822
823 // We implement this by simply making both entries in the hash table
824 // point to the same Symbol structure. That is easy enough if this is
825 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
826 // that we have seen both already, in which case they will both have
827 // independent entries in the symbol table. We can't simply change
828 // the symbol table entry, because we have pointers to the entries
829 // attached to the object files. So we mark the entry attached to the
830 // object file as a forwarder, and record it in the forwarders_ map.
831 // Note that entries in the hash table will never be marked as
832 // forwarders.
833 //
834 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
835 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
836 // for a special section code. ST_SHNDX may be modified if the symbol
837 // is defined in a section being discarded.
838
839 template<int size, bool big_endian>
840 Sized_symbol<size>*
841 Symbol_table::add_from_object(Object* object,
842 const char *name,
843 Stringpool::Key name_key,
844 const char *version,
845 Stringpool::Key version_key,
846 bool is_default_version,
847 const elfcpp::Sym<size, big_endian>& sym,
848 unsigned int st_shndx,
849 bool is_ordinary,
850 unsigned int orig_st_shndx)
851 {
852 // Print a message if this symbol is being traced.
853 if (parameters->options().is_trace_symbol(name))
854 {
855 if (orig_st_shndx == elfcpp::SHN_UNDEF)
856 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
857 else
858 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
859 }
860
861 // For an undefined symbol, we may need to adjust the name using
862 // --wrap.
863 if (orig_st_shndx == elfcpp::SHN_UNDEF
864 && parameters->options().any_wrap())
865 {
866 const char* wrap_name = this->wrap_symbol(name, &name_key);
867 if (wrap_name != name)
868 {
869 // If we see a reference to malloc with version GLIBC_2.0,
870 // and we turn it into a reference to __wrap_malloc, then we
871 // discard the version number. Otherwise the user would be
872 // required to specify the correct version for
873 // __wrap_malloc.
874 version = NULL;
875 version_key = 0;
876 name = wrap_name;
877 }
878 }
879
880 Symbol* const snull = NULL;
881 std::pair<typename Symbol_table_type::iterator, bool> ins =
882 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
883 snull));
884
885 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
886 std::make_pair(this->table_.end(), false);
887 if (is_default_version)
888 {
889 const Stringpool::Key vnull_key = 0;
890 insdefault = this->table_.insert(std::make_pair(std::make_pair(name_key,
891 vnull_key),
892 snull));
893 }
894
895 // ins.first: an iterator, which is a pointer to a pair.
896 // ins.first->first: the key (a pair of name and version).
897 // ins.first->second: the value (Symbol*).
898 // ins.second: true if new entry was inserted, false if not.
899
900 Sized_symbol<size>* ret;
901 bool was_undefined;
902 bool was_common;
903 if (!ins.second)
904 {
905 // We already have an entry for NAME/VERSION.
906 ret = this->get_sized_symbol<size>(ins.first->second);
907 gold_assert(ret != NULL);
908
909 was_undefined = ret->is_undefined();
910 was_common = ret->is_common();
911
912 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
913 version);
914 if (parameters->options().gc_sections())
915 this->gc_mark_dyn_syms(ret);
916
917 if (is_default_version)
918 this->define_default_version<size, big_endian>(ret, insdefault.second,
919 insdefault.first);
920 }
921 else
922 {
923 // This is the first time we have seen NAME/VERSION.
924 gold_assert(ins.first->second == NULL);
925
926 if (is_default_version && !insdefault.second)
927 {
928 // We already have an entry for NAME/NULL. If we override
929 // it, then change it to NAME/VERSION.
930 ret = this->get_sized_symbol<size>(insdefault.first->second);
931
932 was_undefined = ret->is_undefined();
933 was_common = ret->is_common();
934
935 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
936 version);
937 if (parameters->options().gc_sections())
938 this->gc_mark_dyn_syms(ret);
939 ins.first->second = ret;
940 }
941 else
942 {
943 was_undefined = false;
944 was_common = false;
945
946 Sized_target<size, big_endian>* target =
947 parameters->sized_target<size, big_endian>();
948 if (!target->has_make_symbol())
949 ret = new Sized_symbol<size>();
950 else
951 {
952 ret = target->make_symbol();
953 if (ret == NULL)
954 {
955 // This means that we don't want a symbol table
956 // entry after all.
957 if (!is_default_version)
958 this->table_.erase(ins.first);
959 else
960 {
961 this->table_.erase(insdefault.first);
962 // Inserting INSDEFAULT invalidated INS.
963 this->table_.erase(std::make_pair(name_key,
964 version_key));
965 }
966 return NULL;
967 }
968 }
969
970 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
971
972 ins.first->second = ret;
973 if (is_default_version)
974 {
975 // This is the first time we have seen NAME/NULL. Point
976 // it at the new entry for NAME/VERSION.
977 gold_assert(insdefault.second);
978 insdefault.first->second = ret;
979 }
980 }
981
982 if (is_default_version)
983 ret->set_is_default();
984 }
985
986 // Record every time we see a new undefined symbol, to speed up
987 // archive groups.
988 if (!was_undefined && ret->is_undefined())
989 ++this->saw_undefined_;
990
991 // Keep track of common symbols, to speed up common symbol
992 // allocation.
993 if (!was_common && ret->is_common())
994 {
995 if (ret->type() == elfcpp::STT_TLS)
996 this->tls_commons_.push_back(ret);
997 else if (!is_ordinary
998 && st_shndx == parameters->target().small_common_shndx())
999 this->small_commons_.push_back(ret);
1000 else if (!is_ordinary
1001 && st_shndx == parameters->target().large_common_shndx())
1002 this->large_commons_.push_back(ret);
1003 else
1004 this->commons_.push_back(ret);
1005 }
1006
1007 // If we're not doing a relocatable link, then any symbol with
1008 // hidden or internal visibility is local.
1009 if ((ret->visibility() == elfcpp::STV_HIDDEN
1010 || ret->visibility() == elfcpp::STV_INTERNAL)
1011 && (ret->binding() == elfcpp::STB_GLOBAL
1012 || ret->binding() == elfcpp::STB_GNU_UNIQUE
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 bool is_defined_in_discarded_section = false;
1073 if (st_shndx != elfcpp::SHN_UNDEF
1074 && is_ordinary
1075 && !relobj->is_section_included(st_shndx))
1076 {
1077 st_shndx = elfcpp::SHN_UNDEF;
1078 is_defined_in_discarded_section = true;
1079 }
1080
1081 // In an object file, an '@' in the name separates the symbol
1082 // name from the version name. If there are two '@' characters,
1083 // this is the default version.
1084 const char* ver = strchr(name, '@');
1085 Stringpool::Key ver_key = 0;
1086 int namelen = 0;
1087 // IS_DEFAULT_VERSION: is the version default?
1088 // IS_FORCED_LOCAL: is the symbol forced local?
1089 bool is_default_version = false;
1090 bool is_forced_local = false;
1091
1092 if (ver != NULL)
1093 {
1094 // The symbol name is of the form foo@VERSION or foo@@VERSION
1095 namelen = ver - name;
1096 ++ver;
1097 if (*ver == '@')
1098 {
1099 is_default_version = true;
1100 ++ver;
1101 }
1102 ver = this->namepool_.add(ver, true, &ver_key);
1103 }
1104 // We don't want to assign a version to an undefined symbol,
1105 // even if it is listed in the version script. FIXME: What
1106 // about a common symbol?
1107 else
1108 {
1109 namelen = strlen(name);
1110 if (!this->version_script_.empty()
1111 && st_shndx != elfcpp::SHN_UNDEF)
1112 {
1113 // The symbol name did not have a version, but the
1114 // version script may assign a version anyway.
1115 std::string version;
1116 if (this->version_script_.get_symbol_version(name, &version))
1117 {
1118 // The version can be empty if the version script is
1119 // only used to force some symbols to be local.
1120 if (!version.empty())
1121 {
1122 ver = this->namepool_.add_with_length(version.c_str(),
1123 version.length(),
1124 true,
1125 &ver_key);
1126 is_default_version = true;
1127 }
1128 }
1129 else if (this->version_script_.symbol_is_local(name))
1130 is_forced_local = true;
1131 }
1132 }
1133
1134 elfcpp::Sym<size, big_endian>* psym = &sym;
1135 unsigned char symbuf[sym_size];
1136 elfcpp::Sym<size, big_endian> sym2(symbuf);
1137 if (just_symbols)
1138 {
1139 memcpy(symbuf, p, sym_size);
1140 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1141 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1142 {
1143 // Symbol values in object files are section relative.
1144 // This is normally what we want, but since here we are
1145 // converting the symbol to absolute we need to add the
1146 // section address. The section address in an object
1147 // file is normally zero, but people can use a linker
1148 // script to change it.
1149 sw.put_st_value(sym.get_st_value()
1150 + relobj->section_address(orig_st_shndx));
1151 }
1152 st_shndx = elfcpp::SHN_ABS;
1153 is_ordinary = false;
1154 psym = &sym2;
1155 }
1156
1157 // Fix up visibility if object has no-export set.
1158 if (relobj->no_export()
1159 && (orig_st_shndx != elfcpp::SHN_UNDEF || !is_ordinary))
1160 {
1161 // We may have copied symbol already above.
1162 if (psym != &sym2)
1163 {
1164 memcpy(symbuf, p, sym_size);
1165 psym = &sym2;
1166 }
1167
1168 elfcpp::STV visibility = sym2.get_st_visibility();
1169 if (visibility == elfcpp::STV_DEFAULT
1170 || visibility == elfcpp::STV_PROTECTED)
1171 {
1172 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1173 unsigned char nonvis = sym2.get_st_nonvis();
1174 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1175 }
1176 }
1177
1178 Stringpool::Key name_key;
1179 name = this->namepool_.add_with_length(name, namelen, true,
1180 &name_key);
1181
1182 Sized_symbol<size>* res;
1183 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1184 is_default_version, *psym, st_shndx,
1185 is_ordinary, orig_st_shndx);
1186
1187 // If building a shared library using garbage collection, do not
1188 // treat externally visible symbols as garbage.
1189 if (parameters->options().gc_sections()
1190 && parameters->options().shared())
1191 this->gc_mark_symbol_for_shlib(res);
1192
1193 if (is_forced_local)
1194 this->force_local(res);
1195
1196 if (is_defined_in_discarded_section)
1197 res->set_is_defined_in_discarded_section();
1198
1199 (*sympointers)[i] = res;
1200 }
1201 }
1202
1203 // Add a symbol from a plugin-claimed file.
1204
1205 template<int size, bool big_endian>
1206 Symbol*
1207 Symbol_table::add_from_pluginobj(
1208 Sized_pluginobj<size, big_endian>* obj,
1209 const char* name,
1210 const char* ver,
1211 elfcpp::Sym<size, big_endian>* sym)
1212 {
1213 unsigned int st_shndx = sym->get_st_shndx();
1214 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1215
1216 Stringpool::Key ver_key = 0;
1217 bool is_default_version = false;
1218 bool is_forced_local = false;
1219
1220 if (ver != NULL)
1221 {
1222 ver = this->namepool_.add(ver, true, &ver_key);
1223 }
1224 // We don't want to assign a version to an undefined symbol,
1225 // even if it is listed in the version script. FIXME: What
1226 // about a common symbol?
1227 else
1228 {
1229 if (!this->version_script_.empty()
1230 && st_shndx != elfcpp::SHN_UNDEF)
1231 {
1232 // The symbol name did not have a version, but the
1233 // version script may assign a version anyway.
1234 std::string version;
1235 if (this->version_script_.get_symbol_version(name, &version))
1236 {
1237 // The version can be empty if the version script is
1238 // only used to force some symbols to be local.
1239 if (!version.empty())
1240 {
1241 ver = this->namepool_.add_with_length(version.c_str(),
1242 version.length(),
1243 true,
1244 &ver_key);
1245 is_default_version = true;
1246 }
1247 }
1248 else if (this->version_script_.symbol_is_local(name))
1249 is_forced_local = true;
1250 }
1251 }
1252
1253 Stringpool::Key name_key;
1254 name = this->namepool_.add(name, true, &name_key);
1255
1256 Sized_symbol<size>* res;
1257 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1258 is_default_version, *sym, st_shndx,
1259 is_ordinary, st_shndx);
1260
1261 if (is_forced_local)
1262 this->force_local(res);
1263
1264 return res;
1265 }
1266
1267 // Add all the symbols in a dynamic object to the hash table.
1268
1269 template<int size, bool big_endian>
1270 void
1271 Symbol_table::add_from_dynobj(
1272 Sized_dynobj<size, big_endian>* dynobj,
1273 const unsigned char* syms,
1274 size_t count,
1275 const char* sym_names,
1276 size_t sym_name_size,
1277 const unsigned char* versym,
1278 size_t versym_size,
1279 const std::vector<const char*>* version_map,
1280 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1281 size_t* defined)
1282 {
1283 *defined = 0;
1284
1285 gold_assert(size == parameters->target().get_size());
1286
1287 if (dynobj->just_symbols())
1288 {
1289 gold_error(_("--just-symbols does not make sense with a shared object"));
1290 return;
1291 }
1292
1293 if (versym != NULL && versym_size / 2 < count)
1294 {
1295 dynobj->error(_("too few symbol versions"));
1296 return;
1297 }
1298
1299 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1300
1301 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1302 // weak aliases. This is necessary because if the dynamic object
1303 // provides the same variable under two names, one of which is a
1304 // weak definition, and the regular object refers to the weak
1305 // definition, we have to put both the weak definition and the
1306 // strong definition into the dynamic symbol table. Given a weak
1307 // definition, the only way that we can find the corresponding
1308 // strong definition, if any, is to search the symbol table.
1309 std::vector<Sized_symbol<size>*> object_symbols;
1310
1311 const unsigned char* p = syms;
1312 const unsigned char* vs = versym;
1313 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1314 {
1315 elfcpp::Sym<size, big_endian> sym(p);
1316
1317 if (sympointers != NULL)
1318 (*sympointers)[i] = NULL;
1319
1320 // Ignore symbols with local binding or that have
1321 // internal or hidden visibility.
1322 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1323 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1324 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1325 continue;
1326
1327 // A protected symbol in a shared library must be treated as a
1328 // normal symbol when viewed from outside the shared library.
1329 // Implement this by overriding the visibility here.
1330 elfcpp::Sym<size, big_endian>* psym = &sym;
1331 unsigned char symbuf[sym_size];
1332 elfcpp::Sym<size, big_endian> sym2(symbuf);
1333 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1334 {
1335 memcpy(symbuf, p, sym_size);
1336 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1337 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1338 psym = &sym2;
1339 }
1340
1341 unsigned int st_name = psym->get_st_name();
1342 if (st_name >= sym_name_size)
1343 {
1344 dynobj->error(_("bad symbol name offset %u at %zu"),
1345 st_name, i);
1346 continue;
1347 }
1348
1349 const char* name = sym_names + st_name;
1350
1351 bool is_ordinary;
1352 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1353 &is_ordinary);
1354
1355 if (st_shndx != elfcpp::SHN_UNDEF)
1356 ++*defined;
1357
1358 Sized_symbol<size>* res;
1359
1360 if (versym == NULL)
1361 {
1362 Stringpool::Key name_key;
1363 name = this->namepool_.add(name, true, &name_key);
1364 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1365 false, *psym, st_shndx, is_ordinary,
1366 st_shndx);
1367 }
1368 else
1369 {
1370 // Read the version information.
1371
1372 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1373
1374 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1375 v &= elfcpp::VERSYM_VERSION;
1376
1377 // The Sun documentation says that V can be VER_NDX_LOCAL,
1378 // or VER_NDX_GLOBAL, or a version index. The meaning of
1379 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1380 // The old GNU linker will happily generate VER_NDX_LOCAL
1381 // for an undefined symbol. I don't know what the Sun
1382 // linker will generate.
1383
1384 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1385 && st_shndx != elfcpp::SHN_UNDEF)
1386 {
1387 // This symbol should not be visible outside the object.
1388 continue;
1389 }
1390
1391 // At this point we are definitely going to add this symbol.
1392 Stringpool::Key name_key;
1393 name = this->namepool_.add(name, true, &name_key);
1394
1395 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1396 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1397 {
1398 // This symbol does not have a version.
1399 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1400 false, *psym, st_shndx, is_ordinary,
1401 st_shndx);
1402 }
1403 else
1404 {
1405 if (v >= version_map->size())
1406 {
1407 dynobj->error(_("versym for symbol %zu out of range: %u"),
1408 i, v);
1409 continue;
1410 }
1411
1412 const char* version = (*version_map)[v];
1413 if (version == NULL)
1414 {
1415 dynobj->error(_("versym for symbol %zu has no name: %u"),
1416 i, v);
1417 continue;
1418 }
1419
1420 Stringpool::Key version_key;
1421 version = this->namepool_.add(version, true, &version_key);
1422
1423 // If this is an absolute symbol, and the version name
1424 // and symbol name are the same, then this is the
1425 // version definition symbol. These symbols exist to
1426 // support using -u to pull in particular versions. We
1427 // do not want to record a version for them.
1428 if (st_shndx == elfcpp::SHN_ABS
1429 && !is_ordinary
1430 && name_key == version_key)
1431 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1432 false, *psym, st_shndx, is_ordinary,
1433 st_shndx);
1434 else
1435 {
1436 const bool is_default_version =
1437 !hidden && st_shndx != elfcpp::SHN_UNDEF;
1438 res = this->add_from_object(dynobj, name, name_key, version,
1439 version_key, is_default_version,
1440 *psym, st_shndx,
1441 is_ordinary, st_shndx);
1442 }
1443 }
1444 }
1445
1446 // Note that it is possible that RES was overridden by an
1447 // earlier object, in which case it can't be aliased here.
1448 if (st_shndx != elfcpp::SHN_UNDEF
1449 && is_ordinary
1450 && psym->get_st_type() == elfcpp::STT_OBJECT
1451 && res->source() == Symbol::FROM_OBJECT
1452 && res->object() == dynobj)
1453 object_symbols.push_back(res);
1454
1455 if (sympointers != NULL)
1456 (*sympointers)[i] = res;
1457 }
1458
1459 this->record_weak_aliases(&object_symbols);
1460 }
1461
1462 // This is used to sort weak aliases. We sort them first by section
1463 // index, then by offset, then by weak ahead of strong.
1464
1465 template<int size>
1466 class Weak_alias_sorter
1467 {
1468 public:
1469 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1470 };
1471
1472 template<int size>
1473 bool
1474 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1475 const Sized_symbol<size>* s2) const
1476 {
1477 bool is_ordinary;
1478 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1479 gold_assert(is_ordinary);
1480 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1481 gold_assert(is_ordinary);
1482 if (s1_shndx != s2_shndx)
1483 return s1_shndx < s2_shndx;
1484
1485 if (s1->value() != s2->value())
1486 return s1->value() < s2->value();
1487 if (s1->binding() != s2->binding())
1488 {
1489 if (s1->binding() == elfcpp::STB_WEAK)
1490 return true;
1491 if (s2->binding() == elfcpp::STB_WEAK)
1492 return false;
1493 }
1494 return std::string(s1->name()) < std::string(s2->name());
1495 }
1496
1497 // SYMBOLS is a list of object symbols from a dynamic object. Look
1498 // for any weak aliases, and record them so that if we add the weak
1499 // alias to the dynamic symbol table, we also add the corresponding
1500 // strong symbol.
1501
1502 template<int size>
1503 void
1504 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1505 {
1506 // Sort the vector by section index, then by offset, then by weak
1507 // ahead of strong.
1508 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1509
1510 // Walk through the vector. For each weak definition, record
1511 // aliases.
1512 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1513 symbols->begin();
1514 p != symbols->end();
1515 ++p)
1516 {
1517 if ((*p)->binding() != elfcpp::STB_WEAK)
1518 continue;
1519
1520 // Build a circular list of weak aliases. Each symbol points to
1521 // the next one in the circular list.
1522
1523 Sized_symbol<size>* from_sym = *p;
1524 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1525 for (q = p + 1; q != symbols->end(); ++q)
1526 {
1527 bool dummy;
1528 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1529 || (*q)->value() != from_sym->value())
1530 break;
1531
1532 this->weak_aliases_[from_sym] = *q;
1533 from_sym->set_has_alias();
1534 from_sym = *q;
1535 }
1536
1537 if (from_sym != *p)
1538 {
1539 this->weak_aliases_[from_sym] = *p;
1540 from_sym->set_has_alias();
1541 }
1542
1543 p = q - 1;
1544 }
1545 }
1546
1547 // Create and return a specially defined symbol. If ONLY_IF_REF is
1548 // true, then only create the symbol if there is a reference to it.
1549 // If this does not return NULL, it sets *POLDSYM to the existing
1550 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1551 // resolve the newly created symbol to the old one. This
1552 // canonicalizes *PNAME and *PVERSION.
1553
1554 template<int size, bool big_endian>
1555 Sized_symbol<size>*
1556 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1557 bool only_if_ref,
1558 Sized_symbol<size>** poldsym,
1559 bool *resolve_oldsym)
1560 {
1561 *resolve_oldsym = false;
1562
1563 // If the caller didn't give us a version, see if we get one from
1564 // the version script.
1565 std::string v;
1566 bool is_default_version = false;
1567 if (*pversion == NULL)
1568 {
1569 if (this->version_script_.get_symbol_version(*pname, &v))
1570 {
1571 if (!v.empty())
1572 *pversion = v.c_str();
1573
1574 // If we get the version from a version script, then we are
1575 // also the default version.
1576 is_default_version = true;
1577 }
1578 }
1579
1580 Symbol* oldsym;
1581 Sized_symbol<size>* sym;
1582
1583 bool add_to_table = false;
1584 typename Symbol_table_type::iterator add_loc = this->table_.end();
1585 bool add_def_to_table = false;
1586 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1587
1588 if (only_if_ref)
1589 {
1590 oldsym = this->lookup(*pname, *pversion);
1591 if (oldsym == NULL && is_default_version)
1592 oldsym = this->lookup(*pname, NULL);
1593 if (oldsym == NULL || !oldsym->is_undefined())
1594 return NULL;
1595
1596 *pname = oldsym->name();
1597 if (!is_default_version)
1598 *pversion = oldsym->version();
1599 }
1600 else
1601 {
1602 // Canonicalize NAME and VERSION.
1603 Stringpool::Key name_key;
1604 *pname = this->namepool_.add(*pname, true, &name_key);
1605
1606 Stringpool::Key version_key = 0;
1607 if (*pversion != NULL)
1608 *pversion = this->namepool_.add(*pversion, true, &version_key);
1609
1610 Symbol* const snull = NULL;
1611 std::pair<typename Symbol_table_type::iterator, bool> ins =
1612 this->table_.insert(std::make_pair(std::make_pair(name_key,
1613 version_key),
1614 snull));
1615
1616 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
1617 std::make_pair(this->table_.end(), false);
1618 if (is_default_version)
1619 {
1620 const Stringpool::Key vnull = 0;
1621 insdefault =
1622 this->table_.insert(std::make_pair(std::make_pair(name_key,
1623 vnull),
1624 snull));
1625 }
1626
1627 if (!ins.second)
1628 {
1629 // We already have a symbol table entry for NAME/VERSION.
1630 oldsym = ins.first->second;
1631 gold_assert(oldsym != NULL);
1632
1633 if (is_default_version)
1634 {
1635 Sized_symbol<size>* soldsym =
1636 this->get_sized_symbol<size>(oldsym);
1637 this->define_default_version<size, big_endian>(soldsym,
1638 insdefault.second,
1639 insdefault.first);
1640 }
1641 }
1642 else
1643 {
1644 // We haven't seen this symbol before.
1645 gold_assert(ins.first->second == NULL);
1646
1647 add_to_table = true;
1648 add_loc = ins.first;
1649
1650 if (is_default_version && !insdefault.second)
1651 {
1652 // We are adding NAME/VERSION, and it is the default
1653 // version. We already have an entry for NAME/NULL.
1654 oldsym = insdefault.first->second;
1655 *resolve_oldsym = true;
1656 }
1657 else
1658 {
1659 oldsym = NULL;
1660
1661 if (is_default_version)
1662 {
1663 add_def_to_table = true;
1664 add_def_loc = insdefault.first;
1665 }
1666 }
1667 }
1668 }
1669
1670 const Target& target = parameters->target();
1671 if (!target.has_make_symbol())
1672 sym = new Sized_symbol<size>();
1673 else
1674 {
1675 Sized_target<size, big_endian>* sized_target =
1676 parameters->sized_target<size, big_endian>();
1677 sym = sized_target->make_symbol();
1678 if (sym == NULL)
1679 return NULL;
1680 }
1681
1682 if (add_to_table)
1683 add_loc->second = sym;
1684 else
1685 gold_assert(oldsym != NULL);
1686
1687 if (add_def_to_table)
1688 add_def_loc->second = sym;
1689
1690 *poldsym = this->get_sized_symbol<size>(oldsym);
1691
1692 return sym;
1693 }
1694
1695 // Define a symbol based on an Output_data.
1696
1697 Symbol*
1698 Symbol_table::define_in_output_data(const char* name,
1699 const char* version,
1700 Defined defined,
1701 Output_data* od,
1702 uint64_t value,
1703 uint64_t symsize,
1704 elfcpp::STT type,
1705 elfcpp::STB binding,
1706 elfcpp::STV visibility,
1707 unsigned char nonvis,
1708 bool offset_is_from_end,
1709 bool only_if_ref)
1710 {
1711 if (parameters->target().get_size() == 32)
1712 {
1713 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1714 return this->do_define_in_output_data<32>(name, version, defined, od,
1715 value, symsize, type, binding,
1716 visibility, nonvis,
1717 offset_is_from_end,
1718 only_if_ref);
1719 #else
1720 gold_unreachable();
1721 #endif
1722 }
1723 else if (parameters->target().get_size() == 64)
1724 {
1725 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1726 return this->do_define_in_output_data<64>(name, version, defined, od,
1727 value, symsize, type, binding,
1728 visibility, nonvis,
1729 offset_is_from_end,
1730 only_if_ref);
1731 #else
1732 gold_unreachable();
1733 #endif
1734 }
1735 else
1736 gold_unreachable();
1737 }
1738
1739 // Define a symbol in an Output_data, sized version.
1740
1741 template<int size>
1742 Sized_symbol<size>*
1743 Symbol_table::do_define_in_output_data(
1744 const char* name,
1745 const char* version,
1746 Defined defined,
1747 Output_data* od,
1748 typename elfcpp::Elf_types<size>::Elf_Addr value,
1749 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1750 elfcpp::STT type,
1751 elfcpp::STB binding,
1752 elfcpp::STV visibility,
1753 unsigned char nonvis,
1754 bool offset_is_from_end,
1755 bool only_if_ref)
1756 {
1757 Sized_symbol<size>* sym;
1758 Sized_symbol<size>* oldsym;
1759 bool resolve_oldsym;
1760
1761 if (parameters->target().is_big_endian())
1762 {
1763 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1764 sym = this->define_special_symbol<size, true>(&name, &version,
1765 only_if_ref, &oldsym,
1766 &resolve_oldsym);
1767 #else
1768 gold_unreachable();
1769 #endif
1770 }
1771 else
1772 {
1773 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1774 sym = this->define_special_symbol<size, false>(&name, &version,
1775 only_if_ref, &oldsym,
1776 &resolve_oldsym);
1777 #else
1778 gold_unreachable();
1779 #endif
1780 }
1781
1782 if (sym == NULL)
1783 return NULL;
1784
1785 sym->init_output_data(name, version, od, value, symsize, type, binding,
1786 visibility, nonvis, offset_is_from_end);
1787
1788 if (oldsym == NULL)
1789 {
1790 if (binding == elfcpp::STB_LOCAL
1791 || this->version_script_.symbol_is_local(name))
1792 this->force_local(sym);
1793 else if (version != NULL)
1794 sym->set_is_default();
1795 return sym;
1796 }
1797
1798 if (Symbol_table::should_override_with_special(oldsym, defined))
1799 this->override_with_special(oldsym, sym);
1800
1801 if (resolve_oldsym)
1802 return sym;
1803 else
1804 {
1805 delete sym;
1806 return oldsym;
1807 }
1808 }
1809
1810 // Define a symbol based on an Output_segment.
1811
1812 Symbol*
1813 Symbol_table::define_in_output_segment(const char* name,
1814 const char* version,
1815 Defined defined,
1816 Output_segment* os,
1817 uint64_t value,
1818 uint64_t symsize,
1819 elfcpp::STT type,
1820 elfcpp::STB binding,
1821 elfcpp::STV visibility,
1822 unsigned char nonvis,
1823 Symbol::Segment_offset_base offset_base,
1824 bool only_if_ref)
1825 {
1826 if (parameters->target().get_size() == 32)
1827 {
1828 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1829 return this->do_define_in_output_segment<32>(name, version, defined, os,
1830 value, symsize, type,
1831 binding, visibility, nonvis,
1832 offset_base, only_if_ref);
1833 #else
1834 gold_unreachable();
1835 #endif
1836 }
1837 else if (parameters->target().get_size() == 64)
1838 {
1839 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1840 return this->do_define_in_output_segment<64>(name, version, defined, os,
1841 value, symsize, type,
1842 binding, visibility, nonvis,
1843 offset_base, only_if_ref);
1844 #else
1845 gold_unreachable();
1846 #endif
1847 }
1848 else
1849 gold_unreachable();
1850 }
1851
1852 // Define a symbol in an Output_segment, sized version.
1853
1854 template<int size>
1855 Sized_symbol<size>*
1856 Symbol_table::do_define_in_output_segment(
1857 const char* name,
1858 const char* version,
1859 Defined defined,
1860 Output_segment* os,
1861 typename elfcpp::Elf_types<size>::Elf_Addr value,
1862 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1863 elfcpp::STT type,
1864 elfcpp::STB binding,
1865 elfcpp::STV visibility,
1866 unsigned char nonvis,
1867 Symbol::Segment_offset_base offset_base,
1868 bool only_if_ref)
1869 {
1870 Sized_symbol<size>* sym;
1871 Sized_symbol<size>* oldsym;
1872 bool resolve_oldsym;
1873
1874 if (parameters->target().is_big_endian())
1875 {
1876 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1877 sym = this->define_special_symbol<size, true>(&name, &version,
1878 only_if_ref, &oldsym,
1879 &resolve_oldsym);
1880 #else
1881 gold_unreachable();
1882 #endif
1883 }
1884 else
1885 {
1886 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1887 sym = this->define_special_symbol<size, false>(&name, &version,
1888 only_if_ref, &oldsym,
1889 &resolve_oldsym);
1890 #else
1891 gold_unreachable();
1892 #endif
1893 }
1894
1895 if (sym == NULL)
1896 return NULL;
1897
1898 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1899 visibility, nonvis, offset_base);
1900
1901 if (oldsym == NULL)
1902 {
1903 if (binding == elfcpp::STB_LOCAL
1904 || this->version_script_.symbol_is_local(name))
1905 this->force_local(sym);
1906 else if (version != NULL)
1907 sym->set_is_default();
1908 return sym;
1909 }
1910
1911 if (Symbol_table::should_override_with_special(oldsym, defined))
1912 this->override_with_special(oldsym, sym);
1913
1914 if (resolve_oldsym)
1915 return sym;
1916 else
1917 {
1918 delete sym;
1919 return oldsym;
1920 }
1921 }
1922
1923 // Define a special symbol with a constant value. It is a multiple
1924 // definition error if this symbol is already defined.
1925
1926 Symbol*
1927 Symbol_table::define_as_constant(const char* name,
1928 const char* version,
1929 Defined defined,
1930 uint64_t value,
1931 uint64_t symsize,
1932 elfcpp::STT type,
1933 elfcpp::STB binding,
1934 elfcpp::STV visibility,
1935 unsigned char nonvis,
1936 bool only_if_ref,
1937 bool force_override)
1938 {
1939 if (parameters->target().get_size() == 32)
1940 {
1941 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1942 return this->do_define_as_constant<32>(name, version, defined, value,
1943 symsize, type, binding,
1944 visibility, nonvis, only_if_ref,
1945 force_override);
1946 #else
1947 gold_unreachable();
1948 #endif
1949 }
1950 else if (parameters->target().get_size() == 64)
1951 {
1952 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1953 return this->do_define_as_constant<64>(name, version, defined, value,
1954 symsize, type, binding,
1955 visibility, nonvis, only_if_ref,
1956 force_override);
1957 #else
1958 gold_unreachable();
1959 #endif
1960 }
1961 else
1962 gold_unreachable();
1963 }
1964
1965 // Define a symbol as a constant, sized version.
1966
1967 template<int size>
1968 Sized_symbol<size>*
1969 Symbol_table::do_define_as_constant(
1970 const char* name,
1971 const char* version,
1972 Defined defined,
1973 typename elfcpp::Elf_types<size>::Elf_Addr value,
1974 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1975 elfcpp::STT type,
1976 elfcpp::STB binding,
1977 elfcpp::STV visibility,
1978 unsigned char nonvis,
1979 bool only_if_ref,
1980 bool force_override)
1981 {
1982 Sized_symbol<size>* sym;
1983 Sized_symbol<size>* oldsym;
1984 bool resolve_oldsym;
1985
1986 if (parameters->target().is_big_endian())
1987 {
1988 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1989 sym = this->define_special_symbol<size, true>(&name, &version,
1990 only_if_ref, &oldsym,
1991 &resolve_oldsym);
1992 #else
1993 gold_unreachable();
1994 #endif
1995 }
1996 else
1997 {
1998 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1999 sym = this->define_special_symbol<size, false>(&name, &version,
2000 only_if_ref, &oldsym,
2001 &resolve_oldsym);
2002 #else
2003 gold_unreachable();
2004 #endif
2005 }
2006
2007 if (sym == NULL)
2008 return NULL;
2009
2010 sym->init_constant(name, version, value, symsize, type, binding, visibility,
2011 nonvis);
2012
2013 if (oldsym == NULL)
2014 {
2015 // Version symbols are absolute symbols with name == version.
2016 // We don't want to force them to be local.
2017 if ((version == NULL
2018 || name != version
2019 || value != 0)
2020 && (binding == elfcpp::STB_LOCAL
2021 || this->version_script_.symbol_is_local(name)))
2022 this->force_local(sym);
2023 else if (version != NULL
2024 && (name != version || value != 0))
2025 sym->set_is_default();
2026 return sym;
2027 }
2028
2029 if (force_override
2030 || Symbol_table::should_override_with_special(oldsym, defined))
2031 this->override_with_special(oldsym, sym);
2032
2033 if (resolve_oldsym)
2034 return sym;
2035 else
2036 {
2037 delete sym;
2038 return oldsym;
2039 }
2040 }
2041
2042 // Define a set of symbols in output sections.
2043
2044 void
2045 Symbol_table::define_symbols(const Layout* layout, int count,
2046 const Define_symbol_in_section* p,
2047 bool only_if_ref)
2048 {
2049 for (int i = 0; i < count; ++i, ++p)
2050 {
2051 Output_section* os = layout->find_output_section(p->output_section);
2052 if (os != NULL)
2053 this->define_in_output_data(p->name, NULL, PREDEFINED, os, p->value,
2054 p->size, p->type, p->binding,
2055 p->visibility, p->nonvis,
2056 p->offset_is_from_end,
2057 only_if_ref || p->only_if_ref);
2058 else
2059 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2060 p->type, p->binding, p->visibility, p->nonvis,
2061 only_if_ref || p->only_if_ref,
2062 false);
2063 }
2064 }
2065
2066 // Define a set of symbols in output segments.
2067
2068 void
2069 Symbol_table::define_symbols(const Layout* layout, int count,
2070 const Define_symbol_in_segment* p,
2071 bool only_if_ref)
2072 {
2073 for (int i = 0; i < count; ++i, ++p)
2074 {
2075 Output_segment* os = layout->find_output_segment(p->segment_type,
2076 p->segment_flags_set,
2077 p->segment_flags_clear);
2078 if (os != NULL)
2079 this->define_in_output_segment(p->name, NULL, PREDEFINED, os, p->value,
2080 p->size, p->type, p->binding,
2081 p->visibility, p->nonvis,
2082 p->offset_base,
2083 only_if_ref || p->only_if_ref);
2084 else
2085 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2086 p->type, p->binding, p->visibility, p->nonvis,
2087 only_if_ref || p->only_if_ref,
2088 false);
2089 }
2090 }
2091
2092 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2093 // symbol should be defined--typically a .dyn.bss section. VALUE is
2094 // the offset within POSD.
2095
2096 template<int size>
2097 void
2098 Symbol_table::define_with_copy_reloc(
2099 Sized_symbol<size>* csym,
2100 Output_data* posd,
2101 typename elfcpp::Elf_types<size>::Elf_Addr value)
2102 {
2103 gold_assert(csym->is_from_dynobj());
2104 gold_assert(!csym->is_copied_from_dynobj());
2105 Object* object = csym->object();
2106 gold_assert(object->is_dynamic());
2107 Dynobj* dynobj = static_cast<Dynobj*>(object);
2108
2109 // Our copied variable has to override any variable in a shared
2110 // library.
2111 elfcpp::STB binding = csym->binding();
2112 if (binding == elfcpp::STB_WEAK)
2113 binding = elfcpp::STB_GLOBAL;
2114
2115 this->define_in_output_data(csym->name(), csym->version(), COPY,
2116 posd, value, csym->symsize(),
2117 csym->type(), binding,
2118 csym->visibility(), csym->nonvis(),
2119 false, false);
2120
2121 csym->set_is_copied_from_dynobj();
2122 csym->set_needs_dynsym_entry();
2123
2124 this->copied_symbol_dynobjs_[csym] = dynobj;
2125
2126 // We have now defined all aliases, but we have not entered them all
2127 // in the copied_symbol_dynobjs_ map.
2128 if (csym->has_alias())
2129 {
2130 Symbol* sym = csym;
2131 while (true)
2132 {
2133 sym = this->weak_aliases_[sym];
2134 if (sym == csym)
2135 break;
2136 gold_assert(sym->output_data() == posd);
2137
2138 sym->set_is_copied_from_dynobj();
2139 this->copied_symbol_dynobjs_[sym] = dynobj;
2140 }
2141 }
2142 }
2143
2144 // SYM is defined using a COPY reloc. Return the dynamic object where
2145 // the original definition was found.
2146
2147 Dynobj*
2148 Symbol_table::get_copy_source(const Symbol* sym) const
2149 {
2150 gold_assert(sym->is_copied_from_dynobj());
2151 Copied_symbol_dynobjs::const_iterator p =
2152 this->copied_symbol_dynobjs_.find(sym);
2153 gold_assert(p != this->copied_symbol_dynobjs_.end());
2154 return p->second;
2155 }
2156
2157 // Add any undefined symbols named on the command line.
2158
2159 void
2160 Symbol_table::add_undefined_symbols_from_command_line()
2161 {
2162 if (parameters->options().any_undefined())
2163 {
2164 if (parameters->target().get_size() == 32)
2165 {
2166 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2167 this->do_add_undefined_symbols_from_command_line<32>();
2168 #else
2169 gold_unreachable();
2170 #endif
2171 }
2172 else if (parameters->target().get_size() == 64)
2173 {
2174 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2175 this->do_add_undefined_symbols_from_command_line<64>();
2176 #else
2177 gold_unreachable();
2178 #endif
2179 }
2180 else
2181 gold_unreachable();
2182 }
2183 }
2184
2185 template<int size>
2186 void
2187 Symbol_table::do_add_undefined_symbols_from_command_line()
2188 {
2189 for (options::String_set::const_iterator p =
2190 parameters->options().undefined_begin();
2191 p != parameters->options().undefined_end();
2192 ++p)
2193 {
2194 const char* name = p->c_str();
2195
2196 if (this->lookup(name) != NULL)
2197 continue;
2198
2199 const char* version = NULL;
2200
2201 Sized_symbol<size>* sym;
2202 Sized_symbol<size>* oldsym;
2203 bool resolve_oldsym;
2204 if (parameters->target().is_big_endian())
2205 {
2206 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2207 sym = this->define_special_symbol<size, true>(&name, &version,
2208 false, &oldsym,
2209 &resolve_oldsym);
2210 #else
2211 gold_unreachable();
2212 #endif
2213 }
2214 else
2215 {
2216 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2217 sym = this->define_special_symbol<size, false>(&name, &version,
2218 false, &oldsym,
2219 &resolve_oldsym);
2220 #else
2221 gold_unreachable();
2222 #endif
2223 }
2224
2225 gold_assert(oldsym == NULL);
2226
2227 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2228 elfcpp::STV_DEFAULT, 0);
2229 ++this->saw_undefined_;
2230 }
2231 }
2232
2233 // Set the dynamic symbol indexes. INDEX is the index of the first
2234 // global dynamic symbol. Pointers to the symbols are stored into the
2235 // vector SYMS. The names are added to DYNPOOL. This returns an
2236 // updated dynamic symbol index.
2237
2238 unsigned int
2239 Symbol_table::set_dynsym_indexes(unsigned int index,
2240 std::vector<Symbol*>* syms,
2241 Stringpool* dynpool,
2242 Versions* versions)
2243 {
2244 for (Symbol_table_type::iterator p = this->table_.begin();
2245 p != this->table_.end();
2246 ++p)
2247 {
2248 Symbol* sym = p->second;
2249
2250 // Note that SYM may already have a dynamic symbol index, since
2251 // some symbols appear more than once in the symbol table, with
2252 // and without a version.
2253
2254 if (!sym->should_add_dynsym_entry())
2255 sym->set_dynsym_index(-1U);
2256 else if (!sym->has_dynsym_index())
2257 {
2258 sym->set_dynsym_index(index);
2259 ++index;
2260 syms->push_back(sym);
2261 dynpool->add(sym->name(), false, NULL);
2262
2263 // Record any version information.
2264 if (sym->version() != NULL)
2265 versions->record_version(this, dynpool, sym);
2266
2267 // If the symbol is defined in a dynamic object and is
2268 // referenced in a regular object, then mark the dynamic
2269 // object as needed. This is used to implement --as-needed.
2270 if (sym->is_from_dynobj() && sym->in_reg())
2271 sym->object()->set_is_needed();
2272 }
2273 }
2274
2275 // Finish up the versions. In some cases this may add new dynamic
2276 // symbols.
2277 index = versions->finalize(this, index, syms);
2278
2279 return index;
2280 }
2281
2282 // Set the final values for all the symbols. The index of the first
2283 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2284 // file offset OFF. Add their names to POOL. Return the new file
2285 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2286
2287 off_t
2288 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2289 size_t dyncount, Stringpool* pool,
2290 unsigned int *plocal_symcount)
2291 {
2292 off_t ret;
2293
2294 gold_assert(*plocal_symcount != 0);
2295 this->first_global_index_ = *plocal_symcount;
2296
2297 this->dynamic_offset_ = dynoff;
2298 this->first_dynamic_global_index_ = dyn_global_index;
2299 this->dynamic_count_ = dyncount;
2300
2301 if (parameters->target().get_size() == 32)
2302 {
2303 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2304 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2305 #else
2306 gold_unreachable();
2307 #endif
2308 }
2309 else if (parameters->target().get_size() == 64)
2310 {
2311 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2312 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2313 #else
2314 gold_unreachable();
2315 #endif
2316 }
2317 else
2318 gold_unreachable();
2319
2320 // Now that we have the final symbol table, we can reliably note
2321 // which symbols should get warnings.
2322 this->warnings_.note_warnings(this);
2323
2324 return ret;
2325 }
2326
2327 // SYM is going into the symbol table at *PINDEX. Add the name to
2328 // POOL, update *PINDEX and *POFF.
2329
2330 template<int size>
2331 void
2332 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2333 unsigned int* pindex, off_t* poff)
2334 {
2335 sym->set_symtab_index(*pindex);
2336 pool->add(sym->name(), false, NULL);
2337 ++*pindex;
2338 *poff += elfcpp::Elf_sizes<size>::sym_size;
2339 }
2340
2341 // Set the final value for all the symbols. This is called after
2342 // Layout::finalize, so all the output sections have their final
2343 // address.
2344
2345 template<int size>
2346 off_t
2347 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2348 unsigned int* plocal_symcount)
2349 {
2350 off = align_address(off, size >> 3);
2351 this->offset_ = off;
2352
2353 unsigned int index = *plocal_symcount;
2354 const unsigned int orig_index = index;
2355
2356 // First do all the symbols which have been forced to be local, as
2357 // they must appear before all global symbols.
2358 for (Forced_locals::iterator p = this->forced_locals_.begin();
2359 p != this->forced_locals_.end();
2360 ++p)
2361 {
2362 Symbol* sym = *p;
2363 gold_assert(sym->is_forced_local());
2364 if (this->sized_finalize_symbol<size>(sym))
2365 {
2366 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2367 ++*plocal_symcount;
2368 }
2369 }
2370
2371 // Now do all the remaining symbols.
2372 for (Symbol_table_type::iterator p = this->table_.begin();
2373 p != this->table_.end();
2374 ++p)
2375 {
2376 Symbol* sym = p->second;
2377 if (this->sized_finalize_symbol<size>(sym))
2378 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2379 }
2380
2381 this->output_count_ = index - orig_index;
2382
2383 return off;
2384 }
2385
2386 // Compute the final value of SYM and store status in location PSTATUS.
2387 // During relaxation, this may be called multiple times for a symbol to
2388 // compute its would-be final value in each relaxation pass.
2389
2390 template<int size>
2391 typename Sized_symbol<size>::Value_type
2392 Symbol_table::compute_final_value(
2393 const Sized_symbol<size>* sym,
2394 Compute_final_value_status* pstatus) const
2395 {
2396 typedef typename Sized_symbol<size>::Value_type Value_type;
2397 Value_type value;
2398
2399 switch (sym->source())
2400 {
2401 case Symbol::FROM_OBJECT:
2402 {
2403 bool is_ordinary;
2404 unsigned int shndx = sym->shndx(&is_ordinary);
2405
2406 if (!is_ordinary
2407 && shndx != elfcpp::SHN_ABS
2408 && !Symbol::is_common_shndx(shndx))
2409 {
2410 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2411 return 0;
2412 }
2413
2414 Object* symobj = sym->object();
2415 if (symobj->is_dynamic())
2416 {
2417 value = 0;
2418 shndx = elfcpp::SHN_UNDEF;
2419 }
2420 else if (symobj->pluginobj() != NULL)
2421 {
2422 value = 0;
2423 shndx = elfcpp::SHN_UNDEF;
2424 }
2425 else if (shndx == elfcpp::SHN_UNDEF)
2426 value = 0;
2427 else if (!is_ordinary
2428 && (shndx == elfcpp::SHN_ABS
2429 || Symbol::is_common_shndx(shndx)))
2430 value = sym->value();
2431 else
2432 {
2433 Relobj* relobj = static_cast<Relobj*>(symobj);
2434 Output_section* os = relobj->output_section(shndx);
2435
2436 if (this->is_section_folded(relobj, shndx))
2437 {
2438 gold_assert(os == NULL);
2439 // Get the os of the section it is folded onto.
2440 Section_id folded = this->icf_->get_folded_section(relobj,
2441 shndx);
2442 gold_assert(folded.first != NULL);
2443 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2444 unsigned folded_shndx = folded.second;
2445
2446 os = folded_obj->output_section(folded_shndx);
2447 gold_assert(os != NULL);
2448
2449 // Replace (relobj, shndx) with canonical ICF input section.
2450 shndx = folded_shndx;
2451 relobj = folded_obj;
2452 }
2453
2454 uint64_t secoff64 = relobj->output_section_offset(shndx);
2455 if (os == NULL)
2456 {
2457 bool static_or_reloc = (parameters->doing_static_link() ||
2458 parameters->options().relocatable());
2459 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2460
2461 *pstatus = CFVS_NO_OUTPUT_SECTION;
2462 return 0;
2463 }
2464
2465 if (secoff64 == -1ULL)
2466 {
2467 // The section needs special handling (e.g., a merge section).
2468
2469 value = os->output_address(relobj, shndx, sym->value());
2470 }
2471 else
2472 {
2473 Value_type secoff =
2474 convert_types<Value_type, uint64_t>(secoff64);
2475 if (sym->type() == elfcpp::STT_TLS)
2476 value = sym->value() + os->tls_offset() + secoff;
2477 else
2478 value = sym->value() + os->address() + secoff;
2479 }
2480 }
2481 }
2482 break;
2483
2484 case Symbol::IN_OUTPUT_DATA:
2485 {
2486 Output_data* od = sym->output_data();
2487 value = sym->value();
2488 if (sym->type() != elfcpp::STT_TLS)
2489 value += od->address();
2490 else
2491 {
2492 Output_section* os = od->output_section();
2493 gold_assert(os != NULL);
2494 value += os->tls_offset() + (od->address() - os->address());
2495 }
2496 if (sym->offset_is_from_end())
2497 value += od->data_size();
2498 }
2499 break;
2500
2501 case Symbol::IN_OUTPUT_SEGMENT:
2502 {
2503 Output_segment* os = sym->output_segment();
2504 value = sym->value();
2505 if (sym->type() != elfcpp::STT_TLS)
2506 value += os->vaddr();
2507 switch (sym->offset_base())
2508 {
2509 case Symbol::SEGMENT_START:
2510 break;
2511 case Symbol::SEGMENT_END:
2512 value += os->memsz();
2513 break;
2514 case Symbol::SEGMENT_BSS:
2515 value += os->filesz();
2516 break;
2517 default:
2518 gold_unreachable();
2519 }
2520 }
2521 break;
2522
2523 case Symbol::IS_CONSTANT:
2524 value = sym->value();
2525 break;
2526
2527 case Symbol::IS_UNDEFINED:
2528 value = 0;
2529 break;
2530
2531 default:
2532 gold_unreachable();
2533 }
2534
2535 *pstatus = CFVS_OK;
2536 return value;
2537 }
2538
2539 // Finalize the symbol SYM. This returns true if the symbol should be
2540 // added to the symbol table, false otherwise.
2541
2542 template<int size>
2543 bool
2544 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2545 {
2546 typedef typename Sized_symbol<size>::Value_type Value_type;
2547
2548 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2549
2550 // The default version of a symbol may appear twice in the symbol
2551 // table. We only need to finalize it once.
2552 if (sym->has_symtab_index())
2553 return false;
2554
2555 if (!sym->in_reg())
2556 {
2557 gold_assert(!sym->has_symtab_index());
2558 sym->set_symtab_index(-1U);
2559 gold_assert(sym->dynsym_index() == -1U);
2560 return false;
2561 }
2562
2563 // Compute final symbol value.
2564 Compute_final_value_status status;
2565 Value_type value = this->compute_final_value(sym, &status);
2566
2567 switch (status)
2568 {
2569 case CFVS_OK:
2570 break;
2571 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2572 {
2573 bool is_ordinary;
2574 unsigned int shndx = sym->shndx(&is_ordinary);
2575 gold_error(_("%s: unsupported symbol section 0x%x"),
2576 sym->demangled_name().c_str(), shndx);
2577 }
2578 break;
2579 case CFVS_NO_OUTPUT_SECTION:
2580 sym->set_symtab_index(-1U);
2581 return false;
2582 default:
2583 gold_unreachable();
2584 }
2585
2586 sym->set_value(value);
2587
2588 if (parameters->options().strip_all()
2589 || !parameters->options().should_retain_symbol(sym->name()))
2590 {
2591 sym->set_symtab_index(-1U);
2592 return false;
2593 }
2594
2595 return true;
2596 }
2597
2598 // Write out the global symbols.
2599
2600 void
2601 Symbol_table::write_globals(const Stringpool* sympool,
2602 const Stringpool* dynpool,
2603 Output_symtab_xindex* symtab_xindex,
2604 Output_symtab_xindex* dynsym_xindex,
2605 Output_file* of) const
2606 {
2607 switch (parameters->size_and_endianness())
2608 {
2609 #ifdef HAVE_TARGET_32_LITTLE
2610 case Parameters::TARGET_32_LITTLE:
2611 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2612 dynsym_xindex, of);
2613 break;
2614 #endif
2615 #ifdef HAVE_TARGET_32_BIG
2616 case Parameters::TARGET_32_BIG:
2617 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2618 dynsym_xindex, of);
2619 break;
2620 #endif
2621 #ifdef HAVE_TARGET_64_LITTLE
2622 case Parameters::TARGET_64_LITTLE:
2623 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2624 dynsym_xindex, of);
2625 break;
2626 #endif
2627 #ifdef HAVE_TARGET_64_BIG
2628 case Parameters::TARGET_64_BIG:
2629 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2630 dynsym_xindex, of);
2631 break;
2632 #endif
2633 default:
2634 gold_unreachable();
2635 }
2636 }
2637
2638 // Write out the global symbols.
2639
2640 template<int size, bool big_endian>
2641 void
2642 Symbol_table::sized_write_globals(const Stringpool* sympool,
2643 const Stringpool* dynpool,
2644 Output_symtab_xindex* symtab_xindex,
2645 Output_symtab_xindex* dynsym_xindex,
2646 Output_file* of) const
2647 {
2648 const Target& target = parameters->target();
2649
2650 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2651
2652 const unsigned int output_count = this->output_count_;
2653 const section_size_type oview_size = output_count * sym_size;
2654 const unsigned int first_global_index = this->first_global_index_;
2655 unsigned char* psyms;
2656 if (this->offset_ == 0 || output_count == 0)
2657 psyms = NULL;
2658 else
2659 psyms = of->get_output_view(this->offset_, oview_size);
2660
2661 const unsigned int dynamic_count = this->dynamic_count_;
2662 const section_size_type dynamic_size = dynamic_count * sym_size;
2663 const unsigned int first_dynamic_global_index =
2664 this->first_dynamic_global_index_;
2665 unsigned char* dynamic_view;
2666 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2667 dynamic_view = NULL;
2668 else
2669 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2670
2671 for (Symbol_table_type::const_iterator p = this->table_.begin();
2672 p != this->table_.end();
2673 ++p)
2674 {
2675 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2676
2677 // Possibly warn about unresolved symbols in shared libraries.
2678 this->warn_about_undefined_dynobj_symbol(sym);
2679
2680 unsigned int sym_index = sym->symtab_index();
2681 unsigned int dynsym_index;
2682 if (dynamic_view == NULL)
2683 dynsym_index = -1U;
2684 else
2685 dynsym_index = sym->dynsym_index();
2686
2687 if (sym_index == -1U && dynsym_index == -1U)
2688 {
2689 // This symbol is not included in the output file.
2690 continue;
2691 }
2692
2693 unsigned int shndx;
2694 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2695 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2696 switch (sym->source())
2697 {
2698 case Symbol::FROM_OBJECT:
2699 {
2700 bool is_ordinary;
2701 unsigned int in_shndx = sym->shndx(&is_ordinary);
2702
2703 if (!is_ordinary
2704 && in_shndx != elfcpp::SHN_ABS
2705 && !Symbol::is_common_shndx(in_shndx))
2706 {
2707 gold_error(_("%s: unsupported symbol section 0x%x"),
2708 sym->demangled_name().c_str(), in_shndx);
2709 shndx = in_shndx;
2710 }
2711 else
2712 {
2713 Object* symobj = sym->object();
2714 if (symobj->is_dynamic())
2715 {
2716 if (sym->needs_dynsym_value())
2717 dynsym_value = target.dynsym_value(sym);
2718 shndx = elfcpp::SHN_UNDEF;
2719 }
2720 else if (symobj->pluginobj() != NULL)
2721 shndx = elfcpp::SHN_UNDEF;
2722 else if (in_shndx == elfcpp::SHN_UNDEF
2723 || (!is_ordinary
2724 && (in_shndx == elfcpp::SHN_ABS
2725 || Symbol::is_common_shndx(in_shndx))))
2726 shndx = in_shndx;
2727 else
2728 {
2729 Relobj* relobj = static_cast<Relobj*>(symobj);
2730 Output_section* os = relobj->output_section(in_shndx);
2731 if (this->is_section_folded(relobj, in_shndx))
2732 {
2733 // This global symbol must be written out even though
2734 // it is folded.
2735 // Get the os of the section it is folded onto.
2736 Section_id folded =
2737 this->icf_->get_folded_section(relobj, in_shndx);
2738 gold_assert(folded.first !=NULL);
2739 Relobj* folded_obj =
2740 reinterpret_cast<Relobj*>(folded.first);
2741 os = folded_obj->output_section(folded.second);
2742 gold_assert(os != NULL);
2743 }
2744 gold_assert(os != NULL);
2745 shndx = os->out_shndx();
2746
2747 if (shndx >= elfcpp::SHN_LORESERVE)
2748 {
2749 if (sym_index != -1U)
2750 symtab_xindex->add(sym_index, shndx);
2751 if (dynsym_index != -1U)
2752 dynsym_xindex->add(dynsym_index, shndx);
2753 shndx = elfcpp::SHN_XINDEX;
2754 }
2755
2756 // In object files symbol values are section
2757 // relative.
2758 if (parameters->options().relocatable())
2759 sym_value -= os->address();
2760 }
2761 }
2762 }
2763 break;
2764
2765 case Symbol::IN_OUTPUT_DATA:
2766 shndx = sym->output_data()->out_shndx();
2767 if (shndx >= elfcpp::SHN_LORESERVE)
2768 {
2769 if (sym_index != -1U)
2770 symtab_xindex->add(sym_index, shndx);
2771 if (dynsym_index != -1U)
2772 dynsym_xindex->add(dynsym_index, shndx);
2773 shndx = elfcpp::SHN_XINDEX;
2774 }
2775 break;
2776
2777 case Symbol::IN_OUTPUT_SEGMENT:
2778 shndx = elfcpp::SHN_ABS;
2779 break;
2780
2781 case Symbol::IS_CONSTANT:
2782 shndx = elfcpp::SHN_ABS;
2783 break;
2784
2785 case Symbol::IS_UNDEFINED:
2786 shndx = elfcpp::SHN_UNDEF;
2787 break;
2788
2789 default:
2790 gold_unreachable();
2791 }
2792
2793 if (sym_index != -1U)
2794 {
2795 sym_index -= first_global_index;
2796 gold_assert(sym_index < output_count);
2797 unsigned char* ps = psyms + (sym_index * sym_size);
2798 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2799 sympool, ps);
2800 }
2801
2802 if (dynsym_index != -1U)
2803 {
2804 dynsym_index -= first_dynamic_global_index;
2805 gold_assert(dynsym_index < dynamic_count);
2806 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2807 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2808 dynpool, pd);
2809 }
2810 }
2811
2812 of->write_output_view(this->offset_, oview_size, psyms);
2813 if (dynamic_view != NULL)
2814 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2815 }
2816
2817 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2818 // strtab holding the name.
2819
2820 template<int size, bool big_endian>
2821 void
2822 Symbol_table::sized_write_symbol(
2823 Sized_symbol<size>* sym,
2824 typename elfcpp::Elf_types<size>::Elf_Addr value,
2825 unsigned int shndx,
2826 const Stringpool* pool,
2827 unsigned char* p) const
2828 {
2829 elfcpp::Sym_write<size, big_endian> osym(p);
2830 osym.put_st_name(pool->get_offset(sym->name()));
2831 osym.put_st_value(value);
2832 // Use a symbol size of zero for undefined symbols from shared libraries.
2833 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2834 osym.put_st_size(0);
2835 else
2836 osym.put_st_size(sym->symsize());
2837 elfcpp::STT type = sym->type();
2838 // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2839 if (type == elfcpp::STT_GNU_IFUNC
2840 && sym->is_from_dynobj())
2841 type = elfcpp::STT_FUNC;
2842 // A version script may have overridden the default binding.
2843 if (sym->is_forced_local())
2844 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2845 else
2846 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), type));
2847 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2848 osym.put_st_shndx(shndx);
2849 }
2850
2851 // Check for unresolved symbols in shared libraries. This is
2852 // controlled by the --allow-shlib-undefined option.
2853
2854 // We only warn about libraries for which we have seen all the
2855 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2856 // which were not seen in this link. If we didn't see a DT_NEEDED
2857 // entry, we aren't going to be able to reliably report whether the
2858 // symbol is undefined.
2859
2860 // We also don't warn about libraries found in a system library
2861 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2862 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2863 // can have undefined references satisfied by ld-linux.so.
2864
2865 inline void
2866 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2867 {
2868 bool dummy;
2869 if (sym->source() == Symbol::FROM_OBJECT
2870 && sym->object()->is_dynamic()
2871 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2872 && sym->binding() != elfcpp::STB_WEAK
2873 && !parameters->options().allow_shlib_undefined()
2874 && !parameters->target().is_defined_by_abi(sym)
2875 && !sym->object()->is_in_system_directory())
2876 {
2877 // A very ugly cast.
2878 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2879 if (!dynobj->has_unknown_needed_entries())
2880 gold_undefined_symbol(sym);
2881 }
2882 }
2883
2884 // Write out a section symbol. Return the update offset.
2885
2886 void
2887 Symbol_table::write_section_symbol(const Output_section *os,
2888 Output_symtab_xindex* symtab_xindex,
2889 Output_file* of,
2890 off_t offset) const
2891 {
2892 switch (parameters->size_and_endianness())
2893 {
2894 #ifdef HAVE_TARGET_32_LITTLE
2895 case Parameters::TARGET_32_LITTLE:
2896 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2897 offset);
2898 break;
2899 #endif
2900 #ifdef HAVE_TARGET_32_BIG
2901 case Parameters::TARGET_32_BIG:
2902 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2903 offset);
2904 break;
2905 #endif
2906 #ifdef HAVE_TARGET_64_LITTLE
2907 case Parameters::TARGET_64_LITTLE:
2908 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2909 offset);
2910 break;
2911 #endif
2912 #ifdef HAVE_TARGET_64_BIG
2913 case Parameters::TARGET_64_BIG:
2914 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2915 offset);
2916 break;
2917 #endif
2918 default:
2919 gold_unreachable();
2920 }
2921 }
2922
2923 // Write out a section symbol, specialized for size and endianness.
2924
2925 template<int size, bool big_endian>
2926 void
2927 Symbol_table::sized_write_section_symbol(const Output_section* os,
2928 Output_symtab_xindex* symtab_xindex,
2929 Output_file* of,
2930 off_t offset) const
2931 {
2932 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2933
2934 unsigned char* pov = of->get_output_view(offset, sym_size);
2935
2936 elfcpp::Sym_write<size, big_endian> osym(pov);
2937 osym.put_st_name(0);
2938 if (parameters->options().relocatable())
2939 osym.put_st_value(0);
2940 else
2941 osym.put_st_value(os->address());
2942 osym.put_st_size(0);
2943 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2944 elfcpp::STT_SECTION));
2945 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2946
2947 unsigned int shndx = os->out_shndx();
2948 if (shndx >= elfcpp::SHN_LORESERVE)
2949 {
2950 symtab_xindex->add(os->symtab_index(), shndx);
2951 shndx = elfcpp::SHN_XINDEX;
2952 }
2953 osym.put_st_shndx(shndx);
2954
2955 of->write_output_view(offset, sym_size, pov);
2956 }
2957
2958 // Print statistical information to stderr. This is used for --stats.
2959
2960 void
2961 Symbol_table::print_stats() const
2962 {
2963 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2964 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2965 program_name, this->table_.size(), this->table_.bucket_count());
2966 #else
2967 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2968 program_name, this->table_.size());
2969 #endif
2970 this->namepool_.print_stats("symbol table stringpool");
2971 }
2972
2973 // We check for ODR violations by looking for symbols with the same
2974 // name for which the debugging information reports that they were
2975 // defined in different source locations. When comparing the source
2976 // location, we consider instances with the same base filename and
2977 // line number to be the same. This is because different object
2978 // files/shared libraries can include the same header file using
2979 // different paths, and we don't want to report an ODR violation in
2980 // that case.
2981
2982 // This struct is used to compare line information, as returned by
2983 // Dwarf_line_info::one_addr2line. It implements a < comparison
2984 // operator used with std::set.
2985
2986 struct Odr_violation_compare
2987 {
2988 bool
2989 operator()(const std::string& s1, const std::string& s2) const
2990 {
2991 std::string::size_type pos1 = s1.rfind('/');
2992 std::string::size_type pos2 = s2.rfind('/');
2993 if (pos1 == std::string::npos
2994 || pos2 == std::string::npos)
2995 return s1 < s2;
2996 return s1.compare(pos1, std::string::npos,
2997 s2, pos2, std::string::npos) < 0;
2998 }
2999 };
3000
3001 // Check candidate_odr_violations_ to find symbols with the same name
3002 // but apparently different definitions (different source-file/line-no).
3003
3004 void
3005 Symbol_table::detect_odr_violations(const Task* task,
3006 const char* output_file_name) const
3007 {
3008 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
3009 it != candidate_odr_violations_.end();
3010 ++it)
3011 {
3012 const char* symbol_name = it->first;
3013 // We use a sorted set so the output is deterministic.
3014 std::set<std::string, Odr_violation_compare> line_nums;
3015
3016 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3017 locs = it->second.begin();
3018 locs != it->second.end();
3019 ++locs)
3020 {
3021 // We need to lock the object in order to read it. This
3022 // means that we have to run in a singleton Task. If we
3023 // want to run this in a general Task for better
3024 // performance, we will need one Task for object, plus
3025 // appropriate locking to ensure that we don't conflict with
3026 // other uses of the object. Also note, one_addr2line is not
3027 // currently thread-safe.
3028 Task_lock_obj<Object> tl(task, locs->object);
3029 // 16 is the size of the object-cache that one_addr2line should use.
3030 std::string lineno = Dwarf_line_info::one_addr2line(
3031 locs->object, locs->shndx, locs->offset, 16);
3032 if (!lineno.empty())
3033 line_nums.insert(lineno);
3034 }
3035
3036 if (line_nums.size() > 1)
3037 {
3038 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3039 "places (possible ODR violation):"),
3040 output_file_name, demangle(symbol_name).c_str());
3041 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
3042 it2 != line_nums.end();
3043 ++it2)
3044 fprintf(stderr, " %s\n", it2->c_str());
3045 }
3046 }
3047 // We only call one_addr2line() in this function, so we can clear its cache.
3048 Dwarf_line_info::clear_addr2line_cache();
3049 }
3050
3051 // Warnings functions.
3052
3053 // Add a new warning.
3054
3055 void
3056 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3057 const std::string& warning)
3058 {
3059 name = symtab->canonicalize_name(name);
3060 this->warnings_[name].set(obj, warning);
3061 }
3062
3063 // Look through the warnings and mark the symbols for which we should
3064 // warn. This is called during Layout::finalize when we know the
3065 // sources for all the symbols.
3066
3067 void
3068 Warnings::note_warnings(Symbol_table* symtab)
3069 {
3070 for (Warning_table::iterator p = this->warnings_.begin();
3071 p != this->warnings_.end();
3072 ++p)
3073 {
3074 Symbol* sym = symtab->lookup(p->first, NULL);
3075 if (sym != NULL
3076 && sym->source() == Symbol::FROM_OBJECT
3077 && sym->object() == p->second.object)
3078 sym->set_has_warning();
3079 }
3080 }
3081
3082 // Issue a warning. This is called when we see a relocation against a
3083 // symbol for which has a warning.
3084
3085 template<int size, bool big_endian>
3086 void
3087 Warnings::issue_warning(const Symbol* sym,
3088 const Relocate_info<size, big_endian>* relinfo,
3089 size_t relnum, off_t reloffset) const
3090 {
3091 gold_assert(sym->has_warning());
3092 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3093 gold_assert(p != this->warnings_.end());
3094 gold_warning_at_location(relinfo, relnum, reloffset,
3095 "%s", p->second.text.c_str());
3096 }
3097
3098 // Instantiate the templates we need. We could use the configure
3099 // script to restrict this to only the ones needed for implemented
3100 // targets.
3101
3102 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3103 template
3104 void
3105 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3106 #endif
3107
3108 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3109 template
3110 void
3111 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3112 #endif
3113
3114 #ifdef HAVE_TARGET_32_LITTLE
3115 template
3116 void
3117 Symbol_table::add_from_relobj<32, false>(
3118 Sized_relobj<32, false>* relobj,
3119 const unsigned char* syms,
3120 size_t count,
3121 size_t symndx_offset,
3122 const char* sym_names,
3123 size_t sym_name_size,
3124 Sized_relobj<32, false>::Symbols* sympointers,
3125 size_t* defined);
3126 #endif
3127
3128 #ifdef HAVE_TARGET_32_BIG
3129 template
3130 void
3131 Symbol_table::add_from_relobj<32, true>(
3132 Sized_relobj<32, true>* relobj,
3133 const unsigned char* syms,
3134 size_t count,
3135 size_t symndx_offset,
3136 const char* sym_names,
3137 size_t sym_name_size,
3138 Sized_relobj<32, true>::Symbols* sympointers,
3139 size_t* defined);
3140 #endif
3141
3142 #ifdef HAVE_TARGET_64_LITTLE
3143 template
3144 void
3145 Symbol_table::add_from_relobj<64, false>(
3146 Sized_relobj<64, false>* relobj,
3147 const unsigned char* syms,
3148 size_t count,
3149 size_t symndx_offset,
3150 const char* sym_names,
3151 size_t sym_name_size,
3152 Sized_relobj<64, false>::Symbols* sympointers,
3153 size_t* defined);
3154 #endif
3155
3156 #ifdef HAVE_TARGET_64_BIG
3157 template
3158 void
3159 Symbol_table::add_from_relobj<64, true>(
3160 Sized_relobj<64, true>* relobj,
3161 const unsigned char* syms,
3162 size_t count,
3163 size_t symndx_offset,
3164 const char* sym_names,
3165 size_t sym_name_size,
3166 Sized_relobj<64, true>::Symbols* sympointers,
3167 size_t* defined);
3168 #endif
3169
3170 #ifdef HAVE_TARGET_32_LITTLE
3171 template
3172 Symbol*
3173 Symbol_table::add_from_pluginobj<32, false>(
3174 Sized_pluginobj<32, false>* obj,
3175 const char* name,
3176 const char* ver,
3177 elfcpp::Sym<32, false>* sym);
3178 #endif
3179
3180 #ifdef HAVE_TARGET_32_BIG
3181 template
3182 Symbol*
3183 Symbol_table::add_from_pluginobj<32, true>(
3184 Sized_pluginobj<32, true>* obj,
3185 const char* name,
3186 const char* ver,
3187 elfcpp::Sym<32, true>* sym);
3188 #endif
3189
3190 #ifdef HAVE_TARGET_64_LITTLE
3191 template
3192 Symbol*
3193 Symbol_table::add_from_pluginobj<64, false>(
3194 Sized_pluginobj<64, false>* obj,
3195 const char* name,
3196 const char* ver,
3197 elfcpp::Sym<64, false>* sym);
3198 #endif
3199
3200 #ifdef HAVE_TARGET_64_BIG
3201 template
3202 Symbol*
3203 Symbol_table::add_from_pluginobj<64, true>(
3204 Sized_pluginobj<64, true>* obj,
3205 const char* name,
3206 const char* ver,
3207 elfcpp::Sym<64, true>* sym);
3208 #endif
3209
3210 #ifdef HAVE_TARGET_32_LITTLE
3211 template
3212 void
3213 Symbol_table::add_from_dynobj<32, false>(
3214 Sized_dynobj<32, false>* dynobj,
3215 const unsigned char* syms,
3216 size_t count,
3217 const char* sym_names,
3218 size_t sym_name_size,
3219 const unsigned char* versym,
3220 size_t versym_size,
3221 const std::vector<const char*>* version_map,
3222 Sized_relobj<32, false>::Symbols* sympointers,
3223 size_t* defined);
3224 #endif
3225
3226 #ifdef HAVE_TARGET_32_BIG
3227 template
3228 void
3229 Symbol_table::add_from_dynobj<32, true>(
3230 Sized_dynobj<32, true>* dynobj,
3231 const unsigned char* syms,
3232 size_t count,
3233 const char* sym_names,
3234 size_t sym_name_size,
3235 const unsigned char* versym,
3236 size_t versym_size,
3237 const std::vector<const char*>* version_map,
3238 Sized_relobj<32, true>::Symbols* sympointers,
3239 size_t* defined);
3240 #endif
3241
3242 #ifdef HAVE_TARGET_64_LITTLE
3243 template
3244 void
3245 Symbol_table::add_from_dynobj<64, false>(
3246 Sized_dynobj<64, false>* dynobj,
3247 const unsigned char* syms,
3248 size_t count,
3249 const char* sym_names,
3250 size_t sym_name_size,
3251 const unsigned char* versym,
3252 size_t versym_size,
3253 const std::vector<const char*>* version_map,
3254 Sized_relobj<64, false>::Symbols* sympointers,
3255 size_t* defined);
3256 #endif
3257
3258 #ifdef HAVE_TARGET_64_BIG
3259 template
3260 void
3261 Symbol_table::add_from_dynobj<64, true>(
3262 Sized_dynobj<64, true>* dynobj,
3263 const unsigned char* syms,
3264 size_t count,
3265 const char* sym_names,
3266 size_t sym_name_size,
3267 const unsigned char* versym,
3268 size_t versym_size,
3269 const std::vector<const char*>* version_map,
3270 Sized_relobj<64, true>::Symbols* sympointers,
3271 size_t* defined);
3272 #endif
3273
3274 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3275 template
3276 void
3277 Symbol_table::define_with_copy_reloc<32>(
3278 Sized_symbol<32>* sym,
3279 Output_data* posd,
3280 elfcpp::Elf_types<32>::Elf_Addr value);
3281 #endif
3282
3283 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3284 template
3285 void
3286 Symbol_table::define_with_copy_reloc<64>(
3287 Sized_symbol<64>* sym,
3288 Output_data* posd,
3289 elfcpp::Elf_types<64>::Elf_Addr value);
3290 #endif
3291
3292 #ifdef HAVE_TARGET_32_LITTLE
3293 template
3294 void
3295 Warnings::issue_warning<32, false>(const Symbol* sym,
3296 const Relocate_info<32, false>* relinfo,
3297 size_t relnum, off_t reloffset) const;
3298 #endif
3299
3300 #ifdef HAVE_TARGET_32_BIG
3301 template
3302 void
3303 Warnings::issue_warning<32, true>(const Symbol* sym,
3304 const Relocate_info<32, true>* relinfo,
3305 size_t relnum, off_t reloffset) const;
3306 #endif
3307
3308 #ifdef HAVE_TARGET_64_LITTLE
3309 template
3310 void
3311 Warnings::issue_warning<64, false>(const Symbol* sym,
3312 const Relocate_info<64, false>* relinfo,
3313 size_t relnum, off_t reloffset) const;
3314 #endif
3315
3316 #ifdef HAVE_TARGET_64_BIG
3317 template
3318 void
3319 Warnings::issue_warning<64, true>(const Symbol* sym,
3320 const Relocate_info<64, true>* relinfo,
3321 size_t relnum, off_t reloffset) const;
3322 #endif
3323
3324 } // End namespace gold.
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