* symtab.cc (Symbol_table::add_from_object): Rename def parameter
[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_ = 0;
63 this->type_ = type;
64 this->binding_ = binding;
65 this->visibility_ = visibility;
66 this->nonvis_ = nonvis;
67 this->is_target_special_ = false;
68 this->is_def_ = false;
69 this->is_forwarder_ = false;
70 this->has_alias_ = false;
71 this->needs_dynsym_entry_ = false;
72 this->in_reg_ = false;
73 this->in_dyn_ = false;
74 this->has_plt_offset_ = false;
75 this->has_warning_ = false;
76 this->is_copied_from_dynobj_ = false;
77 this->is_forced_local_ = false;
78 this->is_ordinary_shndx_ = false;
79 this->in_real_elf_ = false;
80 }
81
82 // Return the demangled version of the symbol's name, but only
83 // if the --demangle flag was set.
84
85 static std::string
86 demangle(const char* name)
87 {
88 if (!parameters->options().do_demangle())
89 return name;
90
91 // cplus_demangle allocates memory for the result it returns,
92 // and returns NULL if the name is already demangled.
93 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
94 if (demangled_name == NULL)
95 return name;
96
97 std::string retval(demangled_name);
98 free(demangled_name);
99 return retval;
100 }
101
102 std::string
103 Symbol::demangled_name() const
104 {
105 return demangle(this->name());
106 }
107
108 // Initialize the fields in the base class Symbol for SYM in OBJECT.
109
110 template<int size, bool big_endian>
111 void
112 Symbol::init_base_object(const char* name, const char* version, Object* object,
113 const elfcpp::Sym<size, big_endian>& sym,
114 unsigned int st_shndx, bool is_ordinary)
115 {
116 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
117 sym.get_st_visibility(), sym.get_st_nonvis());
118 this->u_.from_object.object = object;
119 this->u_.from_object.shndx = st_shndx;
120 this->is_ordinary_shndx_ = is_ordinary;
121 this->source_ = FROM_OBJECT;
122 this->in_reg_ = !object->is_dynamic();
123 this->in_dyn_ = object->is_dynamic();
124 this->in_real_elf_ = object->pluginobj() == NULL;
125 }
126
127 // Initialize the fields in the base class Symbol for a symbol defined
128 // in an Output_data.
129
130 void
131 Symbol::init_base_output_data(const char* name, const char* version,
132 Output_data* od, elfcpp::STT type,
133 elfcpp::STB binding, elfcpp::STV visibility,
134 unsigned char nonvis, bool offset_is_from_end)
135 {
136 this->init_fields(name, version, type, binding, visibility, nonvis);
137 this->u_.in_output_data.output_data = od;
138 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
139 this->source_ = IN_OUTPUT_DATA;
140 this->in_reg_ = true;
141 this->in_real_elf_ = true;
142 }
143
144 // Initialize the fields in the base class Symbol for a symbol defined
145 // in an Output_segment.
146
147 void
148 Symbol::init_base_output_segment(const char* name, const char* version,
149 Output_segment* os, elfcpp::STT type,
150 elfcpp::STB binding, elfcpp::STV visibility,
151 unsigned char nonvis,
152 Segment_offset_base offset_base)
153 {
154 this->init_fields(name, version, type, binding, visibility, nonvis);
155 this->u_.in_output_segment.output_segment = os;
156 this->u_.in_output_segment.offset_base = offset_base;
157 this->source_ = IN_OUTPUT_SEGMENT;
158 this->in_reg_ = true;
159 this->in_real_elf_ = true;
160 }
161
162 // Initialize the fields in the base class Symbol for a symbol defined
163 // as a constant.
164
165 void
166 Symbol::init_base_constant(const char* name, const char* version,
167 elfcpp::STT type, elfcpp::STB binding,
168 elfcpp::STV visibility, unsigned char nonvis)
169 {
170 this->init_fields(name, version, type, binding, visibility, nonvis);
171 this->source_ = IS_CONSTANT;
172 this->in_reg_ = true;
173 this->in_real_elf_ = true;
174 }
175
176 // Initialize the fields in the base class Symbol for an undefined
177 // symbol.
178
179 void
180 Symbol::init_base_undefined(const char* name, const char* version,
181 elfcpp::STT type, elfcpp::STB binding,
182 elfcpp::STV visibility, unsigned char nonvis)
183 {
184 this->init_fields(name, version, type, binding, visibility, nonvis);
185 this->dynsym_index_ = -1U;
186 this->source_ = IS_UNDEFINED;
187 this->in_reg_ = true;
188 this->in_real_elf_ = true;
189 }
190
191 // Allocate a common symbol in the base.
192
193 void
194 Symbol::allocate_base_common(Output_data* od)
195 {
196 gold_assert(this->is_common());
197 this->source_ = IN_OUTPUT_DATA;
198 this->u_.in_output_data.output_data = od;
199 this->u_.in_output_data.offset_is_from_end = false;
200 }
201
202 // Initialize the fields in Sized_symbol for SYM in OBJECT.
203
204 template<int size>
205 template<bool big_endian>
206 void
207 Sized_symbol<size>::init_object(const char* name, const char* version,
208 Object* object,
209 const elfcpp::Sym<size, big_endian>& sym,
210 unsigned int st_shndx, bool is_ordinary)
211 {
212 this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
213 this->value_ = sym.get_st_value();
214 this->symsize_ = sym.get_st_size();
215 }
216
217 // Initialize the fields in Sized_symbol for a symbol defined in an
218 // Output_data.
219
220 template<int size>
221 void
222 Sized_symbol<size>::init_output_data(const char* name, const char* version,
223 Output_data* od, Value_type value,
224 Size_type symsize, elfcpp::STT type,
225 elfcpp::STB binding,
226 elfcpp::STV visibility,
227 unsigned char nonvis,
228 bool offset_is_from_end)
229 {
230 this->init_base_output_data(name, version, od, type, binding, visibility,
231 nonvis, offset_is_from_end);
232 this->value_ = value;
233 this->symsize_ = symsize;
234 }
235
236 // Initialize the fields in Sized_symbol for a symbol defined in an
237 // Output_segment.
238
239 template<int size>
240 void
241 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
242 Output_segment* os, Value_type value,
243 Size_type symsize, elfcpp::STT type,
244 elfcpp::STB binding,
245 elfcpp::STV visibility,
246 unsigned char nonvis,
247 Segment_offset_base offset_base)
248 {
249 this->init_base_output_segment(name, version, os, type, binding, visibility,
250 nonvis, offset_base);
251 this->value_ = value;
252 this->symsize_ = symsize;
253 }
254
255 // Initialize the fields in Sized_symbol for a symbol defined as a
256 // constant.
257
258 template<int size>
259 void
260 Sized_symbol<size>::init_constant(const char* name, const char* version,
261 Value_type value, Size_type symsize,
262 elfcpp::STT type, elfcpp::STB binding,
263 elfcpp::STV visibility, unsigned char nonvis)
264 {
265 this->init_base_constant(name, version, type, binding, visibility, nonvis);
266 this->value_ = value;
267 this->symsize_ = symsize;
268 }
269
270 // Initialize the fields in Sized_symbol for an undefined symbol.
271
272 template<int size>
273 void
274 Sized_symbol<size>::init_undefined(const char* name, const char* version,
275 elfcpp::STT type, elfcpp::STB binding,
276 elfcpp::STV visibility, unsigned char nonvis)
277 {
278 this->init_base_undefined(name, version, type, binding, visibility, nonvis);
279 this->value_ = 0;
280 this->symsize_ = 0;
281 }
282
283 // Return true if SHNDX represents a common symbol.
284
285 bool
286 Symbol::is_common_shndx(unsigned int shndx)
287 {
288 return (shndx == elfcpp::SHN_COMMON
289 || shndx == parameters->target().small_common_shndx()
290 || shndx == parameters->target().large_common_shndx());
291 }
292
293 // Allocate a common symbol.
294
295 template<int size>
296 void
297 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
298 {
299 this->allocate_base_common(od);
300 this->value_ = value;
301 }
302
303 // The ""'s around str ensure str is a string literal, so sizeof works.
304 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
305
306 // Return true if this symbol should be added to the dynamic symbol
307 // table.
308
309 inline bool
310 Symbol::should_add_dynsym_entry() const
311 {
312 // If the symbol is used by a dynamic relocation, we need to add it.
313 if (this->needs_dynsym_entry())
314 return true;
315
316 // If this symbol's section is not added, the symbol need not be added.
317 // The section may have been GCed. Note that export_dynamic is being
318 // overridden here. This should not be done for shared objects.
319 if (parameters->options().gc_sections()
320 && !parameters->options().shared()
321 && this->source() == Symbol::FROM_OBJECT
322 && !this->object()->is_dynamic())
323 {
324 Relobj* relobj = static_cast<Relobj*>(this->object());
325 bool is_ordinary;
326 unsigned int shndx = this->shndx(&is_ordinary);
327 if (is_ordinary && shndx != elfcpp::SHN_UNDEF
328 && !relobj->is_section_included(shndx))
329 return false;
330 }
331
332 // If the symbol was forced local in a version script, do not add it.
333 if (this->is_forced_local())
334 return false;
335
336 // If the symbol was forced dynamic in a --dynamic-list file, add it.
337 if (parameters->options().in_dynamic_list(this->name()))
338 return true;
339
340 // If dynamic-list-data was specified, add any STT_OBJECT.
341 if (parameters->options().dynamic_list_data()
342 && !this->is_from_dynobj()
343 && this->type() == elfcpp::STT_OBJECT)
344 return true;
345
346 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
347 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
348 if ((parameters->options().dynamic_list_cpp_new()
349 || parameters->options().dynamic_list_cpp_typeinfo())
350 && !this->is_from_dynobj())
351 {
352 // TODO(csilvers): We could probably figure out if we're an operator
353 // new/delete or typeinfo without the need to demangle.
354 char* demangled_name = cplus_demangle(this->name(),
355 DMGL_ANSI | DMGL_PARAMS);
356 if (demangled_name == NULL)
357 {
358 // Not a C++ symbol, so it can't satisfy these flags
359 }
360 else if (parameters->options().dynamic_list_cpp_new()
361 && (strprefix(demangled_name, "operator new")
362 || strprefix(demangled_name, "operator delete")))
363 {
364 free(demangled_name);
365 return true;
366 }
367 else if (parameters->options().dynamic_list_cpp_typeinfo()
368 && (strprefix(demangled_name, "typeinfo name for")
369 || strprefix(demangled_name, "typeinfo for")))
370 {
371 free(demangled_name);
372 return true;
373 }
374 else
375 free(demangled_name);
376 }
377
378 // If exporting all symbols or building a shared library,
379 // and the symbol is defined in a regular object and is
380 // externally visible, we need to add it.
381 if ((parameters->options().export_dynamic() || parameters->options().shared())
382 && !this->is_from_dynobj()
383 && this->is_externally_visible())
384 return true;
385
386 return false;
387 }
388
389 // Return true if the final value of this symbol is known at link
390 // time.
391
392 bool
393 Symbol::final_value_is_known() const
394 {
395 // If we are not generating an executable, then no final values are
396 // known, since they will change at runtime.
397 if (parameters->options().output_is_position_independent()
398 || parameters->options().relocatable())
399 return false;
400
401 // If the symbol is not from an object file, and is not undefined,
402 // then it is defined, and known.
403 if (this->source_ != FROM_OBJECT)
404 {
405 if (this->source_ != IS_UNDEFINED)
406 return true;
407 }
408 else
409 {
410 // If the symbol is from a dynamic object, then the final value
411 // is not known.
412 if (this->object()->is_dynamic())
413 return false;
414
415 // If the symbol is not undefined (it is defined or common),
416 // then the final value is known.
417 if (!this->is_undefined())
418 return true;
419 }
420
421 // If the symbol is undefined, then whether the final value is known
422 // depends on whether we are doing a static link. If we are doing a
423 // dynamic link, then the final value could be filled in at runtime.
424 // This could reasonably be the case for a weak undefined symbol.
425 return parameters->doing_static_link();
426 }
427
428 // Return the output section where this symbol is defined.
429
430 Output_section*
431 Symbol::output_section() const
432 {
433 switch (this->source_)
434 {
435 case FROM_OBJECT:
436 {
437 unsigned int shndx = this->u_.from_object.shndx;
438 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
439 {
440 gold_assert(!this->u_.from_object.object->is_dynamic());
441 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
442 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
443 return relobj->output_section(shndx);
444 }
445 return NULL;
446 }
447
448 case IN_OUTPUT_DATA:
449 return this->u_.in_output_data.output_data->output_section();
450
451 case IN_OUTPUT_SEGMENT:
452 case IS_CONSTANT:
453 case IS_UNDEFINED:
454 return NULL;
455
456 default:
457 gold_unreachable();
458 }
459 }
460
461 // Set the symbol's output section. This is used for symbols defined
462 // in scripts. This should only be called after the symbol table has
463 // been finalized.
464
465 void
466 Symbol::set_output_section(Output_section* os)
467 {
468 switch (this->source_)
469 {
470 case FROM_OBJECT:
471 case IN_OUTPUT_DATA:
472 gold_assert(this->output_section() == os);
473 break;
474 case IS_CONSTANT:
475 this->source_ = IN_OUTPUT_DATA;
476 this->u_.in_output_data.output_data = os;
477 this->u_.in_output_data.offset_is_from_end = false;
478 break;
479 case IN_OUTPUT_SEGMENT:
480 case IS_UNDEFINED:
481 default:
482 gold_unreachable();
483 }
484 }
485
486 // Class Symbol_table.
487
488 Symbol_table::Symbol_table(unsigned int count,
489 const Version_script_info& version_script)
490 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
491 forwarders_(), commons_(), tls_commons_(), small_commons_(),
492 large_commons_(), forced_locals_(), warnings_(),
493 version_script_(version_script), gc_(NULL), icf_(NULL)
494 {
495 namepool_.reserve(count);
496 }
497
498 Symbol_table::~Symbol_table()
499 {
500 }
501
502 // The hash function. The key values are Stringpool keys.
503
504 inline size_t
505 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
506 {
507 return key.first ^ key.second;
508 }
509
510 // The symbol table key equality function. This is called with
511 // Stringpool keys.
512
513 inline bool
514 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
515 const Symbol_table_key& k2) const
516 {
517 return k1.first == k2.first && k1.second == k2.second;
518 }
519
520 bool
521 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
522 {
523 return (parameters->options().icf_enabled()
524 && this->icf_->is_section_folded(obj, shndx));
525 }
526
527 // For symbols that have been listed with -u option, add them to the
528 // work list to avoid gc'ing them.
529
530 void
531 Symbol_table::gc_mark_undef_symbols()
532 {
533 for (options::String_set::const_iterator p =
534 parameters->options().undefined_begin();
535 p != parameters->options().undefined_end();
536 ++p)
537 {
538 const char* name = p->c_str();
539 Symbol* sym = this->lookup(name);
540 gold_assert (sym != NULL);
541 if (sym->source() == Symbol::FROM_OBJECT
542 && !sym->object()->is_dynamic())
543 {
544 Relobj* obj = static_cast<Relobj*>(sym->object());
545 bool is_ordinary;
546 unsigned int shndx = sym->shndx(&is_ordinary);
547 if (is_ordinary)
548 {
549 gold_assert(this->gc_ != NULL);
550 this->gc_->worklist().push(Section_id(obj, shndx));
551 }
552 }
553 }
554 }
555
556 void
557 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
558 {
559 if (!sym->is_from_dynobj()
560 && sym->is_externally_visible())
561 {
562 //Add the object and section to the work list.
563 Relobj* obj = static_cast<Relobj*>(sym->object());
564 bool is_ordinary;
565 unsigned int shndx = sym->shndx(&is_ordinary);
566 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
567 {
568 gold_assert(this->gc_!= NULL);
569 this->gc_->worklist().push(Section_id(obj, shndx));
570 }
571 }
572 }
573
574 // When doing garbage collection, keep symbols that have been seen in
575 // dynamic objects.
576 inline void
577 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
578 {
579 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
580 && !sym->object()->is_dynamic())
581 {
582 Relobj *obj = static_cast<Relobj*>(sym->object());
583 bool is_ordinary;
584 unsigned int shndx = sym->shndx(&is_ordinary);
585 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
586 {
587 gold_assert(this->gc_ != NULL);
588 this->gc_->worklist().push(Section_id(obj, shndx));
589 }
590 }
591 }
592
593 // Make TO a symbol which forwards to FROM.
594
595 void
596 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
597 {
598 gold_assert(from != to);
599 gold_assert(!from->is_forwarder() && !to->is_forwarder());
600 this->forwarders_[from] = to;
601 from->set_forwarder();
602 }
603
604 // Resolve the forwards from FROM, returning the real symbol.
605
606 Symbol*
607 Symbol_table::resolve_forwards(const Symbol* from) const
608 {
609 gold_assert(from->is_forwarder());
610 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
611 this->forwarders_.find(from);
612 gold_assert(p != this->forwarders_.end());
613 return p->second;
614 }
615
616 // Look up a symbol by name.
617
618 Symbol*
619 Symbol_table::lookup(const char* name, const char* version) const
620 {
621 Stringpool::Key name_key;
622 name = this->namepool_.find(name, &name_key);
623 if (name == NULL)
624 return NULL;
625
626 Stringpool::Key version_key = 0;
627 if (version != NULL)
628 {
629 version = this->namepool_.find(version, &version_key);
630 if (version == NULL)
631 return NULL;
632 }
633
634 Symbol_table_key key(name_key, version_key);
635 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
636 if (p == this->table_.end())
637 return NULL;
638 return p->second;
639 }
640
641 // Resolve a Symbol with another Symbol. This is only used in the
642 // unusual case where there are references to both an unversioned
643 // symbol and a symbol with a version, and we then discover that that
644 // version is the default version. Because this is unusual, we do
645 // this the slow way, by converting back to an ELF symbol.
646
647 template<int size, bool big_endian>
648 void
649 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
650 {
651 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
652 elfcpp::Sym_write<size, big_endian> esym(buf);
653 // We don't bother to set the st_name or the st_shndx field.
654 esym.put_st_value(from->value());
655 esym.put_st_size(from->symsize());
656 esym.put_st_info(from->binding(), from->type());
657 esym.put_st_other(from->visibility(), from->nonvis());
658 bool is_ordinary;
659 unsigned int shndx = from->shndx(&is_ordinary);
660 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
661 from->version());
662 if (from->in_reg())
663 to->set_in_reg();
664 if (from->in_dyn())
665 to->set_in_dyn();
666 if (parameters->options().gc_sections())
667 this->gc_mark_dyn_syms(to);
668 }
669
670 // Record that a symbol is forced to be local by a version script or
671 // by visibility.
672
673 void
674 Symbol_table::force_local(Symbol* sym)
675 {
676 if (!sym->is_defined() && !sym->is_common())
677 return;
678 if (sym->is_forced_local())
679 {
680 // We already got this one.
681 return;
682 }
683 sym->set_is_forced_local();
684 this->forced_locals_.push_back(sym);
685 }
686
687 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
688 // is only called for undefined symbols, when at least one --wrap
689 // option was used.
690
691 const char*
692 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
693 {
694 // For some targets, we need to ignore a specific character when
695 // wrapping, and add it back later.
696 char prefix = '\0';
697 if (name[0] == parameters->target().wrap_char())
698 {
699 prefix = name[0];
700 ++name;
701 }
702
703 if (parameters->options().is_wrap(name))
704 {
705 // Turn NAME into __wrap_NAME.
706 std::string s;
707 if (prefix != '\0')
708 s += prefix;
709 s += "__wrap_";
710 s += name;
711
712 // This will give us both the old and new name in NAMEPOOL_, but
713 // that is OK. Only the versions we need will wind up in the
714 // real string table in the output file.
715 return this->namepool_.add(s.c_str(), true, name_key);
716 }
717
718 const char* const real_prefix = "__real_";
719 const size_t real_prefix_length = strlen(real_prefix);
720 if (strncmp(name, real_prefix, real_prefix_length) == 0
721 && parameters->options().is_wrap(name + real_prefix_length))
722 {
723 // Turn __real_NAME into NAME.
724 std::string s;
725 if (prefix != '\0')
726 s += prefix;
727 s += name + real_prefix_length;
728 return this->namepool_.add(s.c_str(), true, name_key);
729 }
730
731 return name;
732 }
733
734 // This is called when we see a symbol NAME/VERSION, and the symbol
735 // already exists in the symbol table, and VERSION is marked as being
736 // the default version. SYM is the NAME/VERSION symbol we just added.
737 // DEFAULT_IS_NEW is true if this is the first time we have seen the
738 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
739
740 template<int size, bool big_endian>
741 void
742 Symbol_table::define_default_version(Sized_symbol<size>* sym,
743 bool default_is_new,
744 Symbol_table_type::iterator pdef)
745 {
746 if (default_is_new)
747 {
748 // This is the first time we have seen NAME/NULL. Make
749 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
750 // version.
751 pdef->second = sym;
752 sym->set_is_default();
753 }
754 else if (pdef->second == sym)
755 {
756 // NAME/NULL already points to NAME/VERSION. Don't mark the
757 // symbol as the default if it is not already the default.
758 }
759 else
760 {
761 // This is the unfortunate case where we already have entries
762 // for both NAME/VERSION and NAME/NULL. We now see a symbol
763 // NAME/VERSION where VERSION is the default version. We have
764 // already resolved this new symbol with the existing
765 // NAME/VERSION symbol.
766
767 // It's possible that NAME/NULL and NAME/VERSION are both
768 // defined in regular objects. This can only happen if one
769 // object file defines foo and another defines foo@@ver. This
770 // is somewhat obscure, but we call it a multiple definition
771 // error.
772
773 // It's possible that NAME/NULL actually has a version, in which
774 // case it won't be the same as VERSION. This happens with
775 // ver_test_7.so in the testsuite for the symbol t2_2. We see
776 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
777 // then see an unadorned t2_2 in an object file and give it
778 // version VER1 from the version script. This looks like a
779 // default definition for VER1, so it looks like we should merge
780 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
781 // not obvious that this is an error, either. So we just punt.
782
783 // If one of the symbols has non-default visibility, and the
784 // other is defined in a shared object, then they are different
785 // symbols.
786
787 // Otherwise, we just resolve the symbols as though they were
788 // the same.
789
790 if (pdef->second->version() != NULL)
791 gold_assert(pdef->second->version() != sym->version());
792 else if (sym->visibility() != elfcpp::STV_DEFAULT
793 && pdef->second->is_from_dynobj())
794 ;
795 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
796 && sym->is_from_dynobj())
797 ;
798 else
799 {
800 const Sized_symbol<size>* symdef;
801 symdef = this->get_sized_symbol<size>(pdef->second);
802 Symbol_table::resolve<size, big_endian>(sym, symdef);
803 this->make_forwarder(pdef->second, sym);
804 pdef->second = sym;
805 sym->set_is_default();
806 }
807 }
808 }
809
810 // Add one symbol from OBJECT to the symbol table. NAME is symbol
811 // name and VERSION is the version; both are canonicalized. DEF is
812 // whether this is the default version. ST_SHNDX is the symbol's
813 // section index; IS_ORDINARY is whether this is a normal section
814 // rather than a special code.
815
816 // If IS_DEFAULT_VERSION is true, then this is the definition of a
817 // default version of a symbol. That means that any lookup of
818 // NAME/NULL and any lookup of NAME/VERSION should always return the
819 // same symbol. This is obvious for references, but in particular we
820 // want to do this for definitions: overriding NAME/NULL should also
821 // override NAME/VERSION. If we don't do that, it would be very hard
822 // to override functions in a shared library which uses versioning.
823
824 // We implement this by simply making both entries in the hash table
825 // point to the same Symbol structure. That is easy enough if this is
826 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
827 // that we have seen both already, in which case they will both have
828 // independent entries in the symbol table. We can't simply change
829 // the symbol table entry, because we have pointers to the entries
830 // attached to the object files. So we mark the entry attached to the
831 // object file as a forwarder, and record it in the forwarders_ map.
832 // Note that entries in the hash table will never be marked as
833 // forwarders.
834 //
835 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
836 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
837 // for a special section code. ST_SHNDX may be modified if the symbol
838 // is defined in a section being discarded.
839
840 template<int size, bool big_endian>
841 Sized_symbol<size>*
842 Symbol_table::add_from_object(Object* object,
843 const char *name,
844 Stringpool::Key name_key,
845 const char *version,
846 Stringpool::Key version_key,
847 bool is_default_version,
848 const elfcpp::Sym<size, big_endian>& sym,
849 unsigned int st_shndx,
850 bool is_ordinary,
851 unsigned int orig_st_shndx)
852 {
853 // Print a message if this symbol is being traced.
854 if (parameters->options().is_trace_symbol(name))
855 {
856 if (orig_st_shndx == elfcpp::SHN_UNDEF)
857 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
858 else
859 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
860 }
861
862 // For an undefined symbol, we may need to adjust the name using
863 // --wrap.
864 if (orig_st_shndx == elfcpp::SHN_UNDEF
865 && parameters->options().any_wrap())
866 {
867 const char* wrap_name = this->wrap_symbol(name, &name_key);
868 if (wrap_name != name)
869 {
870 // If we see a reference to malloc with version GLIBC_2.0,
871 // and we turn it into a reference to __wrap_malloc, then we
872 // discard the version number. Otherwise the user would be
873 // required to specify the correct version for
874 // __wrap_malloc.
875 version = NULL;
876 version_key = 0;
877 name = wrap_name;
878 }
879 }
880
881 Symbol* const snull = NULL;
882 std::pair<typename Symbol_table_type::iterator, bool> ins =
883 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
884 snull));
885
886 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
887 std::make_pair(this->table_.end(), false);
888 if (is_default_version)
889 {
890 const Stringpool::Key vnull_key = 0;
891 insdefault = this->table_.insert(std::make_pair(std::make_pair(name_key,
892 vnull_key),
893 snull));
894 }
895
896 // ins.first: an iterator, which is a pointer to a pair.
897 // ins.first->first: the key (a pair of name and version).
898 // ins.first->second: the value (Symbol*).
899 // ins.second: true if new entry was inserted, false if not.
900
901 Sized_symbol<size>* ret;
902 bool was_undefined;
903 bool was_common;
904 if (!ins.second)
905 {
906 // We already have an entry for NAME/VERSION.
907 ret = this->get_sized_symbol<size>(ins.first->second);
908 gold_assert(ret != NULL);
909
910 was_undefined = ret->is_undefined();
911 was_common = ret->is_common();
912
913 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
914 version);
915 if (parameters->options().gc_sections())
916 this->gc_mark_dyn_syms(ret);
917
918 if (is_default_version)
919 this->define_default_version<size, big_endian>(ret, insdefault.second,
920 insdefault.first);
921 }
922 else
923 {
924 // This is the first time we have seen NAME/VERSION.
925 gold_assert(ins.first->second == NULL);
926
927 if (is_default_version && !insdefault.second)
928 {
929 // We already have an entry for NAME/NULL. If we override
930 // it, then change it to NAME/VERSION.
931 ret = this->get_sized_symbol<size>(insdefault.first->second);
932
933 was_undefined = ret->is_undefined();
934 was_common = ret->is_common();
935
936 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
937 version);
938 if (parameters->options().gc_sections())
939 this->gc_mark_dyn_syms(ret);
940 ins.first->second = ret;
941 }
942 else
943 {
944 was_undefined = false;
945 was_common = false;
946
947 Sized_target<size, big_endian>* target =
948 parameters->sized_target<size, big_endian>();
949 if (!target->has_make_symbol())
950 ret = new Sized_symbol<size>();
951 else
952 {
953 ret = target->make_symbol();
954 if (ret == NULL)
955 {
956 // This means that we don't want a symbol table
957 // entry after all.
958 if (!is_default_version)
959 this->table_.erase(ins.first);
960 else
961 {
962 this->table_.erase(insdefault.first);
963 // Inserting INSDEFAULT invalidated INS.
964 this->table_.erase(std::make_pair(name_key,
965 version_key));
966 }
967 return NULL;
968 }
969 }
970
971 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
972
973 ins.first->second = ret;
974 if (is_default_version)
975 {
976 // This is the first time we have seen NAME/NULL. Point
977 // it at the new entry for NAME/VERSION.
978 gold_assert(insdefault.second);
979 insdefault.first->second = ret;
980 }
981 }
982
983 if (is_default_version)
984 ret->set_is_default();
985 }
986
987 // Record every time we see a new undefined symbol, to speed up
988 // archive groups.
989 if (!was_undefined && ret->is_undefined())
990 ++this->saw_undefined_;
991
992 // Keep track of common symbols, to speed up common symbol
993 // allocation.
994 if (!was_common && ret->is_common())
995 {
996 if (ret->type() == elfcpp::STT_TLS)
997 this->tls_commons_.push_back(ret);
998 else if (!is_ordinary
999 && st_shndx == parameters->target().small_common_shndx())
1000 this->small_commons_.push_back(ret);
1001 else if (!is_ordinary
1002 && st_shndx == parameters->target().large_common_shndx())
1003 this->large_commons_.push_back(ret);
1004 else
1005 this->commons_.push_back(ret);
1006 }
1007
1008 // If we're not doing a relocatable link, then any symbol with
1009 // hidden or internal visibility is local.
1010 if ((ret->visibility() == elfcpp::STV_HIDDEN
1011 || ret->visibility() == elfcpp::STV_INTERNAL)
1012 && (ret->binding() == elfcpp::STB_GLOBAL
1013 || ret->binding() == elfcpp::STB_GNU_UNIQUE
1014 || ret->binding() == elfcpp::STB_WEAK)
1015 && !parameters->options().relocatable())
1016 this->force_local(ret);
1017
1018 return ret;
1019 }
1020
1021 // Add all the symbols in a relocatable object to the hash table.
1022
1023 template<int size, bool big_endian>
1024 void
1025 Symbol_table::add_from_relobj(
1026 Sized_relobj<size, big_endian>* relobj,
1027 const unsigned char* syms,
1028 size_t count,
1029 size_t symndx_offset,
1030 const char* sym_names,
1031 size_t sym_name_size,
1032 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1033 size_t *defined)
1034 {
1035 *defined = 0;
1036
1037 gold_assert(size == parameters->target().get_size());
1038
1039 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1040
1041 const bool just_symbols = relobj->just_symbols();
1042
1043 const unsigned char* p = syms;
1044 for (size_t i = 0; i < count; ++i, p += sym_size)
1045 {
1046 (*sympointers)[i] = NULL;
1047
1048 elfcpp::Sym<size, big_endian> sym(p);
1049
1050 unsigned int st_name = sym.get_st_name();
1051 if (st_name >= sym_name_size)
1052 {
1053 relobj->error(_("bad global symbol name offset %u at %zu"),
1054 st_name, i);
1055 continue;
1056 }
1057
1058 const char* name = sym_names + st_name;
1059
1060 bool is_ordinary;
1061 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1062 sym.get_st_shndx(),
1063 &is_ordinary);
1064 unsigned int orig_st_shndx = st_shndx;
1065 if (!is_ordinary)
1066 orig_st_shndx = elfcpp::SHN_UNDEF;
1067
1068 if (st_shndx != elfcpp::SHN_UNDEF)
1069 ++*defined;
1070
1071 // A symbol defined in a section which we are not including must
1072 // be treated as an undefined symbol.
1073 if (st_shndx != elfcpp::SHN_UNDEF
1074 && is_ordinary
1075 && !relobj->is_section_included(st_shndx))
1076 st_shndx = elfcpp::SHN_UNDEF;
1077
1078 // In an object file, an '@' in the name separates the symbol
1079 // name from the version name. If there are two '@' characters,
1080 // this is the default version.
1081 const char* ver = strchr(name, '@');
1082 Stringpool::Key ver_key = 0;
1083 int namelen = 0;
1084 // IS_DEFAULT_VERSION: is the version default?
1085 // IS_FORCED_LOCAL: is the symbol forced local?
1086 bool is_default_version = false;
1087 bool is_forced_local = false;
1088
1089 if (ver != NULL)
1090 {
1091 // The symbol name is of the form foo@VERSION or foo@@VERSION
1092 namelen = ver - name;
1093 ++ver;
1094 if (*ver == '@')
1095 {
1096 is_default_version = true;
1097 ++ver;
1098 }
1099 ver = this->namepool_.add(ver, true, &ver_key);
1100 }
1101 // We don't want to assign a version to an undefined symbol,
1102 // even if it is listed in the version script. FIXME: What
1103 // about a common symbol?
1104 else
1105 {
1106 namelen = strlen(name);
1107 if (!this->version_script_.empty()
1108 && st_shndx != elfcpp::SHN_UNDEF)
1109 {
1110 // The symbol name did not have a version, but the
1111 // version script may assign a version anyway.
1112 std::string version;
1113 if (this->version_script_.get_symbol_version(name, &version))
1114 {
1115 // The version can be empty if the version script is
1116 // only used to force some symbols to be local.
1117 if (!version.empty())
1118 {
1119 ver = this->namepool_.add_with_length(version.c_str(),
1120 version.length(),
1121 true,
1122 &ver_key);
1123 is_default_version = true;
1124 }
1125 }
1126 else if (this->version_script_.symbol_is_local(name))
1127 is_forced_local = true;
1128 }
1129 }
1130
1131 elfcpp::Sym<size, big_endian>* psym = &sym;
1132 unsigned char symbuf[sym_size];
1133 elfcpp::Sym<size, big_endian> sym2(symbuf);
1134 if (just_symbols)
1135 {
1136 memcpy(symbuf, p, sym_size);
1137 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1138 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1139 {
1140 // Symbol values in object files are section relative.
1141 // This is normally what we want, but since here we are
1142 // converting the symbol to absolute we need to add the
1143 // section address. The section address in an object
1144 // file is normally zero, but people can use a linker
1145 // script to change it.
1146 sw.put_st_value(sym.get_st_value()
1147 + relobj->section_address(orig_st_shndx));
1148 }
1149 st_shndx = elfcpp::SHN_ABS;
1150 is_ordinary = false;
1151 psym = &sym2;
1152 }
1153
1154 // Fix up visibility if object has no-export set.
1155 if (relobj->no_export()
1156 && (orig_st_shndx != elfcpp::SHN_UNDEF || !is_ordinary))
1157 {
1158 // We may have copied symbol already above.
1159 if (psym != &sym2)
1160 {
1161 memcpy(symbuf, p, sym_size);
1162 psym = &sym2;
1163 }
1164
1165 elfcpp::STV visibility = sym2.get_st_visibility();
1166 if (visibility == elfcpp::STV_DEFAULT
1167 || visibility == elfcpp::STV_PROTECTED)
1168 {
1169 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1170 unsigned char nonvis = sym2.get_st_nonvis();
1171 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1172 }
1173 }
1174
1175 Stringpool::Key name_key;
1176 name = this->namepool_.add_with_length(name, namelen, true,
1177 &name_key);
1178
1179 Sized_symbol<size>* res;
1180 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1181 is_default_version, *psym, st_shndx,
1182 is_ordinary, orig_st_shndx);
1183
1184 // If building a shared library using garbage collection, do not
1185 // treat externally visible symbols as garbage.
1186 if (parameters->options().gc_sections()
1187 && parameters->options().shared())
1188 this->gc_mark_symbol_for_shlib(res);
1189
1190 if (is_forced_local)
1191 this->force_local(res);
1192
1193 (*sympointers)[i] = res;
1194 }
1195 }
1196
1197 // Add a symbol from a plugin-claimed file.
1198
1199 template<int size, bool big_endian>
1200 Symbol*
1201 Symbol_table::add_from_pluginobj(
1202 Sized_pluginobj<size, big_endian>* obj,
1203 const char* name,
1204 const char* ver,
1205 elfcpp::Sym<size, big_endian>* sym)
1206 {
1207 unsigned int st_shndx = sym->get_st_shndx();
1208 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1209
1210 Stringpool::Key ver_key = 0;
1211 bool is_default_version = false;
1212 bool is_forced_local = false;
1213
1214 if (ver != NULL)
1215 {
1216 ver = this->namepool_.add(ver, true, &ver_key);
1217 }
1218 // We don't want to assign a version to an undefined symbol,
1219 // even if it is listed in the version script. FIXME: What
1220 // about a common symbol?
1221 else
1222 {
1223 if (!this->version_script_.empty()
1224 && st_shndx != elfcpp::SHN_UNDEF)
1225 {
1226 // The symbol name did not have a version, but the
1227 // version script may assign a version anyway.
1228 std::string version;
1229 if (this->version_script_.get_symbol_version(name, &version))
1230 {
1231 // The version can be empty if the version script is
1232 // only used to force some symbols to be local.
1233 if (!version.empty())
1234 {
1235 ver = this->namepool_.add_with_length(version.c_str(),
1236 version.length(),
1237 true,
1238 &ver_key);
1239 is_default_version = true;
1240 }
1241 }
1242 else if (this->version_script_.symbol_is_local(name))
1243 is_forced_local = true;
1244 }
1245 }
1246
1247 Stringpool::Key name_key;
1248 name = this->namepool_.add(name, true, &name_key);
1249
1250 Sized_symbol<size>* res;
1251 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1252 is_default_version, *sym, st_shndx,
1253 is_ordinary, st_shndx);
1254
1255 if (is_forced_local)
1256 this->force_local(res);
1257
1258 return res;
1259 }
1260
1261 // Add all the symbols in a dynamic object to the hash table.
1262
1263 template<int size, bool big_endian>
1264 void
1265 Symbol_table::add_from_dynobj(
1266 Sized_dynobj<size, big_endian>* dynobj,
1267 const unsigned char* syms,
1268 size_t count,
1269 const char* sym_names,
1270 size_t sym_name_size,
1271 const unsigned char* versym,
1272 size_t versym_size,
1273 const std::vector<const char*>* version_map,
1274 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1275 size_t* defined)
1276 {
1277 *defined = 0;
1278
1279 gold_assert(size == parameters->target().get_size());
1280
1281 if (dynobj->just_symbols())
1282 {
1283 gold_error(_("--just-symbols does not make sense with a shared object"));
1284 return;
1285 }
1286
1287 if (versym != NULL && versym_size / 2 < count)
1288 {
1289 dynobj->error(_("too few symbol versions"));
1290 return;
1291 }
1292
1293 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1294
1295 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1296 // weak aliases. This is necessary because if the dynamic object
1297 // provides the same variable under two names, one of which is a
1298 // weak definition, and the regular object refers to the weak
1299 // definition, we have to put both the weak definition and the
1300 // strong definition into the dynamic symbol table. Given a weak
1301 // definition, the only way that we can find the corresponding
1302 // strong definition, if any, is to search the symbol table.
1303 std::vector<Sized_symbol<size>*> object_symbols;
1304
1305 const unsigned char* p = syms;
1306 const unsigned char* vs = versym;
1307 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1308 {
1309 elfcpp::Sym<size, big_endian> sym(p);
1310
1311 if (sympointers != NULL)
1312 (*sympointers)[i] = NULL;
1313
1314 // Ignore symbols with local binding or that have
1315 // internal or hidden visibility.
1316 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1317 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1318 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1319 continue;
1320
1321 // A protected symbol in a shared library must be treated as a
1322 // normal symbol when viewed from outside the shared library.
1323 // Implement this by overriding the visibility here.
1324 elfcpp::Sym<size, big_endian>* psym = &sym;
1325 unsigned char symbuf[sym_size];
1326 elfcpp::Sym<size, big_endian> sym2(symbuf);
1327 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1328 {
1329 memcpy(symbuf, p, sym_size);
1330 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1331 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1332 psym = &sym2;
1333 }
1334
1335 unsigned int st_name = psym->get_st_name();
1336 if (st_name >= sym_name_size)
1337 {
1338 dynobj->error(_("bad symbol name offset %u at %zu"),
1339 st_name, i);
1340 continue;
1341 }
1342
1343 const char* name = sym_names + st_name;
1344
1345 bool is_ordinary;
1346 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1347 &is_ordinary);
1348
1349 if (st_shndx != elfcpp::SHN_UNDEF)
1350 ++*defined;
1351
1352 Sized_symbol<size>* res;
1353
1354 if (versym == NULL)
1355 {
1356 Stringpool::Key name_key;
1357 name = this->namepool_.add(name, true, &name_key);
1358 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1359 false, *psym, st_shndx, is_ordinary,
1360 st_shndx);
1361 }
1362 else
1363 {
1364 // Read the version information.
1365
1366 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1367
1368 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1369 v &= elfcpp::VERSYM_VERSION;
1370
1371 // The Sun documentation says that V can be VER_NDX_LOCAL,
1372 // or VER_NDX_GLOBAL, or a version index. The meaning of
1373 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1374 // The old GNU linker will happily generate VER_NDX_LOCAL
1375 // for an undefined symbol. I don't know what the Sun
1376 // linker will generate.
1377
1378 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1379 && st_shndx != elfcpp::SHN_UNDEF)
1380 {
1381 // This symbol should not be visible outside the object.
1382 continue;
1383 }
1384
1385 // At this point we are definitely going to add this symbol.
1386 Stringpool::Key name_key;
1387 name = this->namepool_.add(name, true, &name_key);
1388
1389 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1390 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1391 {
1392 // This symbol does not have a version.
1393 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1394 false, *psym, st_shndx, is_ordinary,
1395 st_shndx);
1396 }
1397 else
1398 {
1399 if (v >= version_map->size())
1400 {
1401 dynobj->error(_("versym for symbol %zu out of range: %u"),
1402 i, v);
1403 continue;
1404 }
1405
1406 const char* version = (*version_map)[v];
1407 if (version == NULL)
1408 {
1409 dynobj->error(_("versym for symbol %zu has no name: %u"),
1410 i, v);
1411 continue;
1412 }
1413
1414 Stringpool::Key version_key;
1415 version = this->namepool_.add(version, true, &version_key);
1416
1417 // If this is an absolute symbol, and the version name
1418 // and symbol name are the same, then this is the
1419 // version definition symbol. These symbols exist to
1420 // support using -u to pull in particular versions. We
1421 // do not want to record a version for them.
1422 if (st_shndx == elfcpp::SHN_ABS
1423 && !is_ordinary
1424 && name_key == version_key)
1425 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1426 false, *psym, st_shndx, is_ordinary,
1427 st_shndx);
1428 else
1429 {
1430 const bool is_default_version =
1431 !hidden && st_shndx != elfcpp::SHN_UNDEF;
1432 res = this->add_from_object(dynobj, name, name_key, version,
1433 version_key, is_default_version,
1434 *psym, st_shndx,
1435 is_ordinary, st_shndx);
1436 }
1437 }
1438 }
1439
1440 // Note that it is possible that RES was overridden by an
1441 // earlier object, in which case it can't be aliased here.
1442 if (st_shndx != elfcpp::SHN_UNDEF
1443 && is_ordinary
1444 && psym->get_st_type() == elfcpp::STT_OBJECT
1445 && res->source() == Symbol::FROM_OBJECT
1446 && res->object() == dynobj)
1447 object_symbols.push_back(res);
1448
1449 if (sympointers != NULL)
1450 (*sympointers)[i] = res;
1451 }
1452
1453 this->record_weak_aliases(&object_symbols);
1454 }
1455
1456 // This is used to sort weak aliases. We sort them first by section
1457 // index, then by offset, then by weak ahead of strong.
1458
1459 template<int size>
1460 class Weak_alias_sorter
1461 {
1462 public:
1463 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1464 };
1465
1466 template<int size>
1467 bool
1468 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1469 const Sized_symbol<size>* s2) const
1470 {
1471 bool is_ordinary;
1472 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1473 gold_assert(is_ordinary);
1474 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1475 gold_assert(is_ordinary);
1476 if (s1_shndx != s2_shndx)
1477 return s1_shndx < s2_shndx;
1478
1479 if (s1->value() != s2->value())
1480 return s1->value() < s2->value();
1481 if (s1->binding() != s2->binding())
1482 {
1483 if (s1->binding() == elfcpp::STB_WEAK)
1484 return true;
1485 if (s2->binding() == elfcpp::STB_WEAK)
1486 return false;
1487 }
1488 return std::string(s1->name()) < std::string(s2->name());
1489 }
1490
1491 // SYMBOLS is a list of object symbols from a dynamic object. Look
1492 // for any weak aliases, and record them so that if we add the weak
1493 // alias to the dynamic symbol table, we also add the corresponding
1494 // strong symbol.
1495
1496 template<int size>
1497 void
1498 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1499 {
1500 // Sort the vector by section index, then by offset, then by weak
1501 // ahead of strong.
1502 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1503
1504 // Walk through the vector. For each weak definition, record
1505 // aliases.
1506 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1507 symbols->begin();
1508 p != symbols->end();
1509 ++p)
1510 {
1511 if ((*p)->binding() != elfcpp::STB_WEAK)
1512 continue;
1513
1514 // Build a circular list of weak aliases. Each symbol points to
1515 // the next one in the circular list.
1516
1517 Sized_symbol<size>* from_sym = *p;
1518 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1519 for (q = p + 1; q != symbols->end(); ++q)
1520 {
1521 bool dummy;
1522 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1523 || (*q)->value() != from_sym->value())
1524 break;
1525
1526 this->weak_aliases_[from_sym] = *q;
1527 from_sym->set_has_alias();
1528 from_sym = *q;
1529 }
1530
1531 if (from_sym != *p)
1532 {
1533 this->weak_aliases_[from_sym] = *p;
1534 from_sym->set_has_alias();
1535 }
1536
1537 p = q - 1;
1538 }
1539 }
1540
1541 // Create and return a specially defined symbol. If ONLY_IF_REF is
1542 // true, then only create the symbol if there is a reference to it.
1543 // If this does not return NULL, it sets *POLDSYM to the existing
1544 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1545 // resolve the newly created symbol to the old one. This
1546 // canonicalizes *PNAME and *PVERSION.
1547
1548 template<int size, bool big_endian>
1549 Sized_symbol<size>*
1550 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1551 bool only_if_ref,
1552 Sized_symbol<size>** poldsym,
1553 bool *resolve_oldsym)
1554 {
1555 *resolve_oldsym = false;
1556
1557 // If the caller didn't give us a version, see if we get one from
1558 // the version script.
1559 std::string v;
1560 bool is_default_version = false;
1561 if (*pversion == NULL)
1562 {
1563 if (this->version_script_.get_symbol_version(*pname, &v))
1564 {
1565 if (!v.empty())
1566 *pversion = v.c_str();
1567
1568 // If we get the version from a version script, then we are
1569 // also the default version.
1570 is_default_version = true;
1571 }
1572 }
1573
1574 Symbol* oldsym;
1575 Sized_symbol<size>* sym;
1576
1577 bool add_to_table = false;
1578 typename Symbol_table_type::iterator add_loc = this->table_.end();
1579 bool add_def_to_table = false;
1580 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1581
1582 if (only_if_ref)
1583 {
1584 oldsym = this->lookup(*pname, *pversion);
1585 if (oldsym == NULL && is_default_version)
1586 oldsym = this->lookup(*pname, NULL);
1587 if (oldsym == NULL || !oldsym->is_undefined())
1588 return NULL;
1589
1590 *pname = oldsym->name();
1591 if (!is_default_version)
1592 *pversion = oldsym->version();
1593 }
1594 else
1595 {
1596 // Canonicalize NAME and VERSION.
1597 Stringpool::Key name_key;
1598 *pname = this->namepool_.add(*pname, true, &name_key);
1599
1600 Stringpool::Key version_key = 0;
1601 if (*pversion != NULL)
1602 *pversion = this->namepool_.add(*pversion, true, &version_key);
1603
1604 Symbol* const snull = NULL;
1605 std::pair<typename Symbol_table_type::iterator, bool> ins =
1606 this->table_.insert(std::make_pair(std::make_pair(name_key,
1607 version_key),
1608 snull));
1609
1610 std::pair<typename Symbol_table_type::iterator, bool> insdefault =
1611 std::make_pair(this->table_.end(), false);
1612 if (is_default_version)
1613 {
1614 const Stringpool::Key vnull = 0;
1615 insdefault =
1616 this->table_.insert(std::make_pair(std::make_pair(name_key,
1617 vnull),
1618 snull));
1619 }
1620
1621 if (!ins.second)
1622 {
1623 // We already have a symbol table entry for NAME/VERSION.
1624 oldsym = ins.first->second;
1625 gold_assert(oldsym != NULL);
1626
1627 if (is_default_version)
1628 {
1629 Sized_symbol<size>* soldsym =
1630 this->get_sized_symbol<size>(oldsym);
1631 this->define_default_version<size, big_endian>(soldsym,
1632 insdefault.second,
1633 insdefault.first);
1634 }
1635 }
1636 else
1637 {
1638 // We haven't seen this symbol before.
1639 gold_assert(ins.first->second == NULL);
1640
1641 add_to_table = true;
1642 add_loc = ins.first;
1643
1644 if (is_default_version && !insdefault.second)
1645 {
1646 // We are adding NAME/VERSION, and it is the default
1647 // version. We already have an entry for NAME/NULL.
1648 oldsym = insdefault.first->second;
1649 *resolve_oldsym = true;
1650 }
1651 else
1652 {
1653 oldsym = NULL;
1654
1655 if (is_default_version)
1656 {
1657 add_def_to_table = true;
1658 add_def_loc = insdefault.first;
1659 }
1660 }
1661 }
1662 }
1663
1664 const Target& target = parameters->target();
1665 if (!target.has_make_symbol())
1666 sym = new Sized_symbol<size>();
1667 else
1668 {
1669 Sized_target<size, big_endian>* sized_target =
1670 parameters->sized_target<size, big_endian>();
1671 sym = sized_target->make_symbol();
1672 if (sym == NULL)
1673 return NULL;
1674 }
1675
1676 if (add_to_table)
1677 add_loc->second = sym;
1678 else
1679 gold_assert(oldsym != NULL);
1680
1681 if (add_def_to_table)
1682 add_def_loc->second = sym;
1683
1684 *poldsym = this->get_sized_symbol<size>(oldsym);
1685
1686 return sym;
1687 }
1688
1689 // Define a symbol based on an Output_data.
1690
1691 Symbol*
1692 Symbol_table::define_in_output_data(const char* name,
1693 const char* version,
1694 Defined defined,
1695 Output_data* od,
1696 uint64_t value,
1697 uint64_t symsize,
1698 elfcpp::STT type,
1699 elfcpp::STB binding,
1700 elfcpp::STV visibility,
1701 unsigned char nonvis,
1702 bool offset_is_from_end,
1703 bool only_if_ref)
1704 {
1705 if (parameters->target().get_size() == 32)
1706 {
1707 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1708 return this->do_define_in_output_data<32>(name, version, defined, od,
1709 value, symsize, type, binding,
1710 visibility, nonvis,
1711 offset_is_from_end,
1712 only_if_ref);
1713 #else
1714 gold_unreachable();
1715 #endif
1716 }
1717 else if (parameters->target().get_size() == 64)
1718 {
1719 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1720 return this->do_define_in_output_data<64>(name, version, defined, od,
1721 value, symsize, type, binding,
1722 visibility, nonvis,
1723 offset_is_from_end,
1724 only_if_ref);
1725 #else
1726 gold_unreachable();
1727 #endif
1728 }
1729 else
1730 gold_unreachable();
1731 }
1732
1733 // Define a symbol in an Output_data, sized version.
1734
1735 template<int size>
1736 Sized_symbol<size>*
1737 Symbol_table::do_define_in_output_data(
1738 const char* name,
1739 const char* version,
1740 Defined defined,
1741 Output_data* od,
1742 typename elfcpp::Elf_types<size>::Elf_Addr value,
1743 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1744 elfcpp::STT type,
1745 elfcpp::STB binding,
1746 elfcpp::STV visibility,
1747 unsigned char nonvis,
1748 bool offset_is_from_end,
1749 bool only_if_ref)
1750 {
1751 Sized_symbol<size>* sym;
1752 Sized_symbol<size>* oldsym;
1753 bool resolve_oldsym;
1754
1755 if (parameters->target().is_big_endian())
1756 {
1757 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1758 sym = this->define_special_symbol<size, true>(&name, &version,
1759 only_if_ref, &oldsym,
1760 &resolve_oldsym);
1761 #else
1762 gold_unreachable();
1763 #endif
1764 }
1765 else
1766 {
1767 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1768 sym = this->define_special_symbol<size, false>(&name, &version,
1769 only_if_ref, &oldsym,
1770 &resolve_oldsym);
1771 #else
1772 gold_unreachable();
1773 #endif
1774 }
1775
1776 if (sym == NULL)
1777 return NULL;
1778
1779 sym->init_output_data(name, version, od, value, symsize, type, binding,
1780 visibility, nonvis, offset_is_from_end);
1781
1782 if (oldsym == NULL)
1783 {
1784 if (binding == elfcpp::STB_LOCAL
1785 || this->version_script_.symbol_is_local(name))
1786 this->force_local(sym);
1787 else if (version != NULL)
1788 sym->set_is_default();
1789 return sym;
1790 }
1791
1792 if (Symbol_table::should_override_with_special(oldsym, defined))
1793 this->override_with_special(oldsym, sym);
1794
1795 if (resolve_oldsym)
1796 return sym;
1797 else
1798 {
1799 delete sym;
1800 return oldsym;
1801 }
1802 }
1803
1804 // Define a symbol based on an Output_segment.
1805
1806 Symbol*
1807 Symbol_table::define_in_output_segment(const char* name,
1808 const char* version,
1809 Defined defined,
1810 Output_segment* os,
1811 uint64_t value,
1812 uint64_t symsize,
1813 elfcpp::STT type,
1814 elfcpp::STB binding,
1815 elfcpp::STV visibility,
1816 unsigned char nonvis,
1817 Symbol::Segment_offset_base offset_base,
1818 bool only_if_ref)
1819 {
1820 if (parameters->target().get_size() == 32)
1821 {
1822 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1823 return this->do_define_in_output_segment<32>(name, version, defined, os,
1824 value, symsize, type,
1825 binding, visibility, nonvis,
1826 offset_base, only_if_ref);
1827 #else
1828 gold_unreachable();
1829 #endif
1830 }
1831 else if (parameters->target().get_size() == 64)
1832 {
1833 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1834 return this->do_define_in_output_segment<64>(name, version, defined, os,
1835 value, symsize, type,
1836 binding, visibility, nonvis,
1837 offset_base, only_if_ref);
1838 #else
1839 gold_unreachable();
1840 #endif
1841 }
1842 else
1843 gold_unreachable();
1844 }
1845
1846 // Define a symbol in an Output_segment, sized version.
1847
1848 template<int size>
1849 Sized_symbol<size>*
1850 Symbol_table::do_define_in_output_segment(
1851 const char* name,
1852 const char* version,
1853 Defined defined,
1854 Output_segment* os,
1855 typename elfcpp::Elf_types<size>::Elf_Addr value,
1856 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1857 elfcpp::STT type,
1858 elfcpp::STB binding,
1859 elfcpp::STV visibility,
1860 unsigned char nonvis,
1861 Symbol::Segment_offset_base offset_base,
1862 bool only_if_ref)
1863 {
1864 Sized_symbol<size>* sym;
1865 Sized_symbol<size>* oldsym;
1866 bool resolve_oldsym;
1867
1868 if (parameters->target().is_big_endian())
1869 {
1870 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1871 sym = this->define_special_symbol<size, true>(&name, &version,
1872 only_if_ref, &oldsym,
1873 &resolve_oldsym);
1874 #else
1875 gold_unreachable();
1876 #endif
1877 }
1878 else
1879 {
1880 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1881 sym = this->define_special_symbol<size, false>(&name, &version,
1882 only_if_ref, &oldsym,
1883 &resolve_oldsym);
1884 #else
1885 gold_unreachable();
1886 #endif
1887 }
1888
1889 if (sym == NULL)
1890 return NULL;
1891
1892 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1893 visibility, nonvis, offset_base);
1894
1895 if (oldsym == NULL)
1896 {
1897 if (binding == elfcpp::STB_LOCAL
1898 || this->version_script_.symbol_is_local(name))
1899 this->force_local(sym);
1900 else if (version != NULL)
1901 sym->set_is_default();
1902 return sym;
1903 }
1904
1905 if (Symbol_table::should_override_with_special(oldsym, defined))
1906 this->override_with_special(oldsym, sym);
1907
1908 if (resolve_oldsym)
1909 return sym;
1910 else
1911 {
1912 delete sym;
1913 return oldsym;
1914 }
1915 }
1916
1917 // Define a special symbol with a constant value. It is a multiple
1918 // definition error if this symbol is already defined.
1919
1920 Symbol*
1921 Symbol_table::define_as_constant(const char* name,
1922 const char* version,
1923 Defined defined,
1924 uint64_t value,
1925 uint64_t symsize,
1926 elfcpp::STT type,
1927 elfcpp::STB binding,
1928 elfcpp::STV visibility,
1929 unsigned char nonvis,
1930 bool only_if_ref,
1931 bool force_override)
1932 {
1933 if (parameters->target().get_size() == 32)
1934 {
1935 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1936 return this->do_define_as_constant<32>(name, version, defined, value,
1937 symsize, type, binding,
1938 visibility, nonvis, only_if_ref,
1939 force_override);
1940 #else
1941 gold_unreachable();
1942 #endif
1943 }
1944 else if (parameters->target().get_size() == 64)
1945 {
1946 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1947 return this->do_define_as_constant<64>(name, version, defined, value,
1948 symsize, type, binding,
1949 visibility, nonvis, only_if_ref,
1950 force_override);
1951 #else
1952 gold_unreachable();
1953 #endif
1954 }
1955 else
1956 gold_unreachable();
1957 }
1958
1959 // Define a symbol as a constant, sized version.
1960
1961 template<int size>
1962 Sized_symbol<size>*
1963 Symbol_table::do_define_as_constant(
1964 const char* name,
1965 const char* version,
1966 Defined defined,
1967 typename elfcpp::Elf_types<size>::Elf_Addr value,
1968 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1969 elfcpp::STT type,
1970 elfcpp::STB binding,
1971 elfcpp::STV visibility,
1972 unsigned char nonvis,
1973 bool only_if_ref,
1974 bool force_override)
1975 {
1976 Sized_symbol<size>* sym;
1977 Sized_symbol<size>* oldsym;
1978 bool resolve_oldsym;
1979
1980 if (parameters->target().is_big_endian())
1981 {
1982 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1983 sym = this->define_special_symbol<size, true>(&name, &version,
1984 only_if_ref, &oldsym,
1985 &resolve_oldsym);
1986 #else
1987 gold_unreachable();
1988 #endif
1989 }
1990 else
1991 {
1992 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1993 sym = this->define_special_symbol<size, false>(&name, &version,
1994 only_if_ref, &oldsym,
1995 &resolve_oldsym);
1996 #else
1997 gold_unreachable();
1998 #endif
1999 }
2000
2001 if (sym == NULL)
2002 return NULL;
2003
2004 sym->init_constant(name, version, value, symsize, type, binding, visibility,
2005 nonvis);
2006
2007 if (oldsym == NULL)
2008 {
2009 // Version symbols are absolute symbols with name == version.
2010 // We don't want to force them to be local.
2011 if ((version == NULL
2012 || name != version
2013 || value != 0)
2014 && (binding == elfcpp::STB_LOCAL
2015 || this->version_script_.symbol_is_local(name)))
2016 this->force_local(sym);
2017 else if (version != NULL
2018 && (name != version || value != 0))
2019 sym->set_is_default();
2020 return sym;
2021 }
2022
2023 if (force_override
2024 || Symbol_table::should_override_with_special(oldsym, defined))
2025 this->override_with_special(oldsym, sym);
2026
2027 if (resolve_oldsym)
2028 return sym;
2029 else
2030 {
2031 delete sym;
2032 return oldsym;
2033 }
2034 }
2035
2036 // Define a set of symbols in output sections.
2037
2038 void
2039 Symbol_table::define_symbols(const Layout* layout, int count,
2040 const Define_symbol_in_section* p,
2041 bool only_if_ref)
2042 {
2043 for (int i = 0; i < count; ++i, ++p)
2044 {
2045 Output_section* os = layout->find_output_section(p->output_section);
2046 if (os != NULL)
2047 this->define_in_output_data(p->name, NULL, PREDEFINED, os, p->value,
2048 p->size, p->type, p->binding,
2049 p->visibility, p->nonvis,
2050 p->offset_is_from_end,
2051 only_if_ref || p->only_if_ref);
2052 else
2053 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2054 p->type, p->binding, p->visibility, p->nonvis,
2055 only_if_ref || p->only_if_ref,
2056 false);
2057 }
2058 }
2059
2060 // Define a set of symbols in output segments.
2061
2062 void
2063 Symbol_table::define_symbols(const Layout* layout, int count,
2064 const Define_symbol_in_segment* p,
2065 bool only_if_ref)
2066 {
2067 for (int i = 0; i < count; ++i, ++p)
2068 {
2069 Output_segment* os = layout->find_output_segment(p->segment_type,
2070 p->segment_flags_set,
2071 p->segment_flags_clear);
2072 if (os != NULL)
2073 this->define_in_output_segment(p->name, NULL, PREDEFINED, os, p->value,
2074 p->size, p->type, p->binding,
2075 p->visibility, p->nonvis,
2076 p->offset_base,
2077 only_if_ref || p->only_if_ref);
2078 else
2079 this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2080 p->type, p->binding, p->visibility, p->nonvis,
2081 only_if_ref || p->only_if_ref,
2082 false);
2083 }
2084 }
2085
2086 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2087 // symbol should be defined--typically a .dyn.bss section. VALUE is
2088 // the offset within POSD.
2089
2090 template<int size>
2091 void
2092 Symbol_table::define_with_copy_reloc(
2093 Sized_symbol<size>* csym,
2094 Output_data* posd,
2095 typename elfcpp::Elf_types<size>::Elf_Addr value)
2096 {
2097 gold_assert(csym->is_from_dynobj());
2098 gold_assert(!csym->is_copied_from_dynobj());
2099 Object* object = csym->object();
2100 gold_assert(object->is_dynamic());
2101 Dynobj* dynobj = static_cast<Dynobj*>(object);
2102
2103 // Our copied variable has to override any variable in a shared
2104 // library.
2105 elfcpp::STB binding = csym->binding();
2106 if (binding == elfcpp::STB_WEAK)
2107 binding = elfcpp::STB_GLOBAL;
2108
2109 this->define_in_output_data(csym->name(), csym->version(), COPY,
2110 posd, value, csym->symsize(),
2111 csym->type(), binding,
2112 csym->visibility(), csym->nonvis(),
2113 false, false);
2114
2115 csym->set_is_copied_from_dynobj();
2116 csym->set_needs_dynsym_entry();
2117
2118 this->copied_symbol_dynobjs_[csym] = dynobj;
2119
2120 // We have now defined all aliases, but we have not entered them all
2121 // in the copied_symbol_dynobjs_ map.
2122 if (csym->has_alias())
2123 {
2124 Symbol* sym = csym;
2125 while (true)
2126 {
2127 sym = this->weak_aliases_[sym];
2128 if (sym == csym)
2129 break;
2130 gold_assert(sym->output_data() == posd);
2131
2132 sym->set_is_copied_from_dynobj();
2133 this->copied_symbol_dynobjs_[sym] = dynobj;
2134 }
2135 }
2136 }
2137
2138 // SYM is defined using a COPY reloc. Return the dynamic object where
2139 // the original definition was found.
2140
2141 Dynobj*
2142 Symbol_table::get_copy_source(const Symbol* sym) const
2143 {
2144 gold_assert(sym->is_copied_from_dynobj());
2145 Copied_symbol_dynobjs::const_iterator p =
2146 this->copied_symbol_dynobjs_.find(sym);
2147 gold_assert(p != this->copied_symbol_dynobjs_.end());
2148 return p->second;
2149 }
2150
2151 // Add any undefined symbols named on the command line.
2152
2153 void
2154 Symbol_table::add_undefined_symbols_from_command_line()
2155 {
2156 if (parameters->options().any_undefined())
2157 {
2158 if (parameters->target().get_size() == 32)
2159 {
2160 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2161 this->do_add_undefined_symbols_from_command_line<32>();
2162 #else
2163 gold_unreachable();
2164 #endif
2165 }
2166 else if (parameters->target().get_size() == 64)
2167 {
2168 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2169 this->do_add_undefined_symbols_from_command_line<64>();
2170 #else
2171 gold_unreachable();
2172 #endif
2173 }
2174 else
2175 gold_unreachable();
2176 }
2177 }
2178
2179 template<int size>
2180 void
2181 Symbol_table::do_add_undefined_symbols_from_command_line()
2182 {
2183 for (options::String_set::const_iterator p =
2184 parameters->options().undefined_begin();
2185 p != parameters->options().undefined_end();
2186 ++p)
2187 {
2188 const char* name = p->c_str();
2189
2190 if (this->lookup(name) != NULL)
2191 continue;
2192
2193 const char* version = NULL;
2194
2195 Sized_symbol<size>* sym;
2196 Sized_symbol<size>* oldsym;
2197 bool resolve_oldsym;
2198 if (parameters->target().is_big_endian())
2199 {
2200 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2201 sym = this->define_special_symbol<size, true>(&name, &version,
2202 false, &oldsym,
2203 &resolve_oldsym);
2204 #else
2205 gold_unreachable();
2206 #endif
2207 }
2208 else
2209 {
2210 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2211 sym = this->define_special_symbol<size, false>(&name, &version,
2212 false, &oldsym,
2213 &resolve_oldsym);
2214 #else
2215 gold_unreachable();
2216 #endif
2217 }
2218
2219 gold_assert(oldsym == NULL);
2220
2221 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2222 elfcpp::STV_DEFAULT, 0);
2223 ++this->saw_undefined_;
2224 }
2225 }
2226
2227 // Set the dynamic symbol indexes. INDEX is the index of the first
2228 // global dynamic symbol. Pointers to the symbols are stored into the
2229 // vector SYMS. The names are added to DYNPOOL. This returns an
2230 // updated dynamic symbol index.
2231
2232 unsigned int
2233 Symbol_table::set_dynsym_indexes(unsigned int index,
2234 std::vector<Symbol*>* syms,
2235 Stringpool* dynpool,
2236 Versions* versions)
2237 {
2238 for (Symbol_table_type::iterator p = this->table_.begin();
2239 p != this->table_.end();
2240 ++p)
2241 {
2242 Symbol* sym = p->second;
2243
2244 // Note that SYM may already have a dynamic symbol index, since
2245 // some symbols appear more than once in the symbol table, with
2246 // and without a version.
2247
2248 if (!sym->should_add_dynsym_entry())
2249 sym->set_dynsym_index(-1U);
2250 else if (!sym->has_dynsym_index())
2251 {
2252 sym->set_dynsym_index(index);
2253 ++index;
2254 syms->push_back(sym);
2255 dynpool->add(sym->name(), false, NULL);
2256
2257 // Record any version information.
2258 if (sym->version() != NULL)
2259 versions->record_version(this, dynpool, sym);
2260
2261 // If the symbol is defined in a dynamic object and is
2262 // referenced in a regular object, then mark the dynamic
2263 // object as needed. This is used to implement --as-needed.
2264 if (sym->is_from_dynobj() && sym->in_reg())
2265 sym->object()->set_is_needed();
2266 }
2267 }
2268
2269 // Finish up the versions. In some cases this may add new dynamic
2270 // symbols.
2271 index = versions->finalize(this, index, syms);
2272
2273 return index;
2274 }
2275
2276 // Set the final values for all the symbols. The index of the first
2277 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2278 // file offset OFF. Add their names to POOL. Return the new file
2279 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2280
2281 off_t
2282 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2283 size_t dyncount, Stringpool* pool,
2284 unsigned int *plocal_symcount)
2285 {
2286 off_t ret;
2287
2288 gold_assert(*plocal_symcount != 0);
2289 this->first_global_index_ = *plocal_symcount;
2290
2291 this->dynamic_offset_ = dynoff;
2292 this->first_dynamic_global_index_ = dyn_global_index;
2293 this->dynamic_count_ = dyncount;
2294
2295 if (parameters->target().get_size() == 32)
2296 {
2297 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2298 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2299 #else
2300 gold_unreachable();
2301 #endif
2302 }
2303 else if (parameters->target().get_size() == 64)
2304 {
2305 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2306 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2307 #else
2308 gold_unreachable();
2309 #endif
2310 }
2311 else
2312 gold_unreachable();
2313
2314 // Now that we have the final symbol table, we can reliably note
2315 // which symbols should get warnings.
2316 this->warnings_.note_warnings(this);
2317
2318 return ret;
2319 }
2320
2321 // SYM is going into the symbol table at *PINDEX. Add the name to
2322 // POOL, update *PINDEX and *POFF.
2323
2324 template<int size>
2325 void
2326 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2327 unsigned int* pindex, off_t* poff)
2328 {
2329 sym->set_symtab_index(*pindex);
2330 pool->add(sym->name(), false, NULL);
2331 ++*pindex;
2332 *poff += elfcpp::Elf_sizes<size>::sym_size;
2333 }
2334
2335 // Set the final value for all the symbols. This is called after
2336 // Layout::finalize, so all the output sections have their final
2337 // address.
2338
2339 template<int size>
2340 off_t
2341 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2342 unsigned int* plocal_symcount)
2343 {
2344 off = align_address(off, size >> 3);
2345 this->offset_ = off;
2346
2347 unsigned int index = *plocal_symcount;
2348 const unsigned int orig_index = index;
2349
2350 // First do all the symbols which have been forced to be local, as
2351 // they must appear before all global symbols.
2352 for (Forced_locals::iterator p = this->forced_locals_.begin();
2353 p != this->forced_locals_.end();
2354 ++p)
2355 {
2356 Symbol* sym = *p;
2357 gold_assert(sym->is_forced_local());
2358 if (this->sized_finalize_symbol<size>(sym))
2359 {
2360 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2361 ++*plocal_symcount;
2362 }
2363 }
2364
2365 // Now do all the remaining symbols.
2366 for (Symbol_table_type::iterator p = this->table_.begin();
2367 p != this->table_.end();
2368 ++p)
2369 {
2370 Symbol* sym = p->second;
2371 if (this->sized_finalize_symbol<size>(sym))
2372 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2373 }
2374
2375 this->output_count_ = index - orig_index;
2376
2377 return off;
2378 }
2379
2380 // Compute the final value of SYM and store status in location PSTATUS.
2381 // During relaxation, this may be called multiple times for a symbol to
2382 // compute its would-be final value in each relaxation pass.
2383
2384 template<int size>
2385 typename Sized_symbol<size>::Value_type
2386 Symbol_table::compute_final_value(
2387 const Sized_symbol<size>* sym,
2388 Compute_final_value_status* pstatus) const
2389 {
2390 typedef typename Sized_symbol<size>::Value_type Value_type;
2391 Value_type value;
2392
2393 switch (sym->source())
2394 {
2395 case Symbol::FROM_OBJECT:
2396 {
2397 bool is_ordinary;
2398 unsigned int shndx = sym->shndx(&is_ordinary);
2399
2400 if (!is_ordinary
2401 && shndx != elfcpp::SHN_ABS
2402 && !Symbol::is_common_shndx(shndx))
2403 {
2404 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2405 return 0;
2406 }
2407
2408 Object* symobj = sym->object();
2409 if (symobj->is_dynamic())
2410 {
2411 value = 0;
2412 shndx = elfcpp::SHN_UNDEF;
2413 }
2414 else if (symobj->pluginobj() != NULL)
2415 {
2416 value = 0;
2417 shndx = elfcpp::SHN_UNDEF;
2418 }
2419 else if (shndx == elfcpp::SHN_UNDEF)
2420 value = 0;
2421 else if (!is_ordinary
2422 && (shndx == elfcpp::SHN_ABS
2423 || Symbol::is_common_shndx(shndx)))
2424 value = sym->value();
2425 else
2426 {
2427 Relobj* relobj = static_cast<Relobj*>(symobj);
2428 Output_section* os = relobj->output_section(shndx);
2429
2430 if (this->is_section_folded(relobj, shndx))
2431 {
2432 gold_assert(os == NULL);
2433 // Get the os of the section it is folded onto.
2434 Section_id folded = this->icf_->get_folded_section(relobj,
2435 shndx);
2436 gold_assert(folded.first != NULL);
2437 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2438 unsigned folded_shndx = folded.second;
2439
2440 os = folded_obj->output_section(folded_shndx);
2441 gold_assert(os != NULL);
2442
2443 // Replace (relobj, shndx) with canonical ICF input section.
2444 shndx = folded_shndx;
2445 relobj = folded_obj;
2446 }
2447
2448 uint64_t secoff64 = relobj->output_section_offset(shndx);
2449 if (os == NULL)
2450 {
2451 bool static_or_reloc = (parameters->doing_static_link() ||
2452 parameters->options().relocatable());
2453 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2454
2455 *pstatus = CFVS_NO_OUTPUT_SECTION;
2456 return 0;
2457 }
2458
2459 if (secoff64 == -1ULL)
2460 {
2461 // The section needs special handling (e.g., a merge section).
2462
2463 value = os->output_address(relobj, shndx, sym->value());
2464 }
2465 else
2466 {
2467 Value_type secoff =
2468 convert_types<Value_type, uint64_t>(secoff64);
2469 if (sym->type() == elfcpp::STT_TLS)
2470 value = sym->value() + os->tls_offset() + secoff;
2471 else
2472 value = sym->value() + os->address() + secoff;
2473 }
2474 }
2475 }
2476 break;
2477
2478 case Symbol::IN_OUTPUT_DATA:
2479 {
2480 Output_data* od = sym->output_data();
2481 value = sym->value();
2482 if (sym->type() != elfcpp::STT_TLS)
2483 value += od->address();
2484 else
2485 {
2486 Output_section* os = od->output_section();
2487 gold_assert(os != NULL);
2488 value += os->tls_offset() + (od->address() - os->address());
2489 }
2490 if (sym->offset_is_from_end())
2491 value += od->data_size();
2492 }
2493 break;
2494
2495 case Symbol::IN_OUTPUT_SEGMENT:
2496 {
2497 Output_segment* os = sym->output_segment();
2498 value = sym->value();
2499 if (sym->type() != elfcpp::STT_TLS)
2500 value += os->vaddr();
2501 switch (sym->offset_base())
2502 {
2503 case Symbol::SEGMENT_START:
2504 break;
2505 case Symbol::SEGMENT_END:
2506 value += os->memsz();
2507 break;
2508 case Symbol::SEGMENT_BSS:
2509 value += os->filesz();
2510 break;
2511 default:
2512 gold_unreachable();
2513 }
2514 }
2515 break;
2516
2517 case Symbol::IS_CONSTANT:
2518 value = sym->value();
2519 break;
2520
2521 case Symbol::IS_UNDEFINED:
2522 value = 0;
2523 break;
2524
2525 default:
2526 gold_unreachable();
2527 }
2528
2529 *pstatus = CFVS_OK;
2530 return value;
2531 }
2532
2533 // Finalize the symbol SYM. This returns true if the symbol should be
2534 // added to the symbol table, false otherwise.
2535
2536 template<int size>
2537 bool
2538 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2539 {
2540 typedef typename Sized_symbol<size>::Value_type Value_type;
2541
2542 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2543
2544 // The default version of a symbol may appear twice in the symbol
2545 // table. We only need to finalize it once.
2546 if (sym->has_symtab_index())
2547 return false;
2548
2549 if (!sym->in_reg())
2550 {
2551 gold_assert(!sym->has_symtab_index());
2552 sym->set_symtab_index(-1U);
2553 gold_assert(sym->dynsym_index() == -1U);
2554 return false;
2555 }
2556
2557 // Compute final symbol value.
2558 Compute_final_value_status status;
2559 Value_type value = this->compute_final_value(sym, &status);
2560
2561 switch (status)
2562 {
2563 case CFVS_OK:
2564 break;
2565 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2566 {
2567 bool is_ordinary;
2568 unsigned int shndx = sym->shndx(&is_ordinary);
2569 gold_error(_("%s: unsupported symbol section 0x%x"),
2570 sym->demangled_name().c_str(), shndx);
2571 }
2572 break;
2573 case CFVS_NO_OUTPUT_SECTION:
2574 sym->set_symtab_index(-1U);
2575 return false;
2576 default:
2577 gold_unreachable();
2578 }
2579
2580 sym->set_value(value);
2581
2582 if (parameters->options().strip_all()
2583 || !parameters->options().should_retain_symbol(sym->name()))
2584 {
2585 sym->set_symtab_index(-1U);
2586 return false;
2587 }
2588
2589 return true;
2590 }
2591
2592 // Write out the global symbols.
2593
2594 void
2595 Symbol_table::write_globals(const Stringpool* sympool,
2596 const Stringpool* dynpool,
2597 Output_symtab_xindex* symtab_xindex,
2598 Output_symtab_xindex* dynsym_xindex,
2599 Output_file* of) const
2600 {
2601 switch (parameters->size_and_endianness())
2602 {
2603 #ifdef HAVE_TARGET_32_LITTLE
2604 case Parameters::TARGET_32_LITTLE:
2605 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2606 dynsym_xindex, of);
2607 break;
2608 #endif
2609 #ifdef HAVE_TARGET_32_BIG
2610 case Parameters::TARGET_32_BIG:
2611 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2612 dynsym_xindex, of);
2613 break;
2614 #endif
2615 #ifdef HAVE_TARGET_64_LITTLE
2616 case Parameters::TARGET_64_LITTLE:
2617 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2618 dynsym_xindex, of);
2619 break;
2620 #endif
2621 #ifdef HAVE_TARGET_64_BIG
2622 case Parameters::TARGET_64_BIG:
2623 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2624 dynsym_xindex, of);
2625 break;
2626 #endif
2627 default:
2628 gold_unreachable();
2629 }
2630 }
2631
2632 // Write out the global symbols.
2633
2634 template<int size, bool big_endian>
2635 void
2636 Symbol_table::sized_write_globals(const Stringpool* sympool,
2637 const Stringpool* dynpool,
2638 Output_symtab_xindex* symtab_xindex,
2639 Output_symtab_xindex* dynsym_xindex,
2640 Output_file* of) const
2641 {
2642 const Target& target = parameters->target();
2643
2644 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2645
2646 const unsigned int output_count = this->output_count_;
2647 const section_size_type oview_size = output_count * sym_size;
2648 const unsigned int first_global_index = this->first_global_index_;
2649 unsigned char* psyms;
2650 if (this->offset_ == 0 || output_count == 0)
2651 psyms = NULL;
2652 else
2653 psyms = of->get_output_view(this->offset_, oview_size);
2654
2655 const unsigned int dynamic_count = this->dynamic_count_;
2656 const section_size_type dynamic_size = dynamic_count * sym_size;
2657 const unsigned int first_dynamic_global_index =
2658 this->first_dynamic_global_index_;
2659 unsigned char* dynamic_view;
2660 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2661 dynamic_view = NULL;
2662 else
2663 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2664
2665 for (Symbol_table_type::const_iterator p = this->table_.begin();
2666 p != this->table_.end();
2667 ++p)
2668 {
2669 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2670
2671 // Possibly warn about unresolved symbols in shared libraries.
2672 this->warn_about_undefined_dynobj_symbol(sym);
2673
2674 unsigned int sym_index = sym->symtab_index();
2675 unsigned int dynsym_index;
2676 if (dynamic_view == NULL)
2677 dynsym_index = -1U;
2678 else
2679 dynsym_index = sym->dynsym_index();
2680
2681 if (sym_index == -1U && dynsym_index == -1U)
2682 {
2683 // This symbol is not included in the output file.
2684 continue;
2685 }
2686
2687 unsigned int shndx;
2688 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2689 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2690 switch (sym->source())
2691 {
2692 case Symbol::FROM_OBJECT:
2693 {
2694 bool is_ordinary;
2695 unsigned int in_shndx = sym->shndx(&is_ordinary);
2696
2697 if (!is_ordinary
2698 && in_shndx != elfcpp::SHN_ABS
2699 && !Symbol::is_common_shndx(in_shndx))
2700 {
2701 gold_error(_("%s: unsupported symbol section 0x%x"),
2702 sym->demangled_name().c_str(), in_shndx);
2703 shndx = in_shndx;
2704 }
2705 else
2706 {
2707 Object* symobj = sym->object();
2708 if (symobj->is_dynamic())
2709 {
2710 if (sym->needs_dynsym_value())
2711 dynsym_value = target.dynsym_value(sym);
2712 shndx = elfcpp::SHN_UNDEF;
2713 }
2714 else if (symobj->pluginobj() != NULL)
2715 shndx = elfcpp::SHN_UNDEF;
2716 else if (in_shndx == elfcpp::SHN_UNDEF
2717 || (!is_ordinary
2718 && (in_shndx == elfcpp::SHN_ABS
2719 || Symbol::is_common_shndx(in_shndx))))
2720 shndx = in_shndx;
2721 else
2722 {
2723 Relobj* relobj = static_cast<Relobj*>(symobj);
2724 Output_section* os = relobj->output_section(in_shndx);
2725 if (this->is_section_folded(relobj, in_shndx))
2726 {
2727 // This global symbol must be written out even though
2728 // it is folded.
2729 // Get the os of the section it is folded onto.
2730 Section_id folded =
2731 this->icf_->get_folded_section(relobj, in_shndx);
2732 gold_assert(folded.first !=NULL);
2733 Relobj* folded_obj =
2734 reinterpret_cast<Relobj*>(folded.first);
2735 os = folded_obj->output_section(folded.second);
2736 gold_assert(os != NULL);
2737 }
2738 gold_assert(os != NULL);
2739 shndx = os->out_shndx();
2740
2741 if (shndx >= elfcpp::SHN_LORESERVE)
2742 {
2743 if (sym_index != -1U)
2744 symtab_xindex->add(sym_index, shndx);
2745 if (dynsym_index != -1U)
2746 dynsym_xindex->add(dynsym_index, shndx);
2747 shndx = elfcpp::SHN_XINDEX;
2748 }
2749
2750 // In object files symbol values are section
2751 // relative.
2752 if (parameters->options().relocatable())
2753 sym_value -= os->address();
2754 }
2755 }
2756 }
2757 break;
2758
2759 case Symbol::IN_OUTPUT_DATA:
2760 shndx = sym->output_data()->out_shndx();
2761 if (shndx >= elfcpp::SHN_LORESERVE)
2762 {
2763 if (sym_index != -1U)
2764 symtab_xindex->add(sym_index, shndx);
2765 if (dynsym_index != -1U)
2766 dynsym_xindex->add(dynsym_index, shndx);
2767 shndx = elfcpp::SHN_XINDEX;
2768 }
2769 break;
2770
2771 case Symbol::IN_OUTPUT_SEGMENT:
2772 shndx = elfcpp::SHN_ABS;
2773 break;
2774
2775 case Symbol::IS_CONSTANT:
2776 shndx = elfcpp::SHN_ABS;
2777 break;
2778
2779 case Symbol::IS_UNDEFINED:
2780 shndx = elfcpp::SHN_UNDEF;
2781 break;
2782
2783 default:
2784 gold_unreachable();
2785 }
2786
2787 if (sym_index != -1U)
2788 {
2789 sym_index -= first_global_index;
2790 gold_assert(sym_index < output_count);
2791 unsigned char* ps = psyms + (sym_index * sym_size);
2792 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2793 sympool, ps);
2794 }
2795
2796 if (dynsym_index != -1U)
2797 {
2798 dynsym_index -= first_dynamic_global_index;
2799 gold_assert(dynsym_index < dynamic_count);
2800 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2801 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2802 dynpool, pd);
2803 }
2804 }
2805
2806 of->write_output_view(this->offset_, oview_size, psyms);
2807 if (dynamic_view != NULL)
2808 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2809 }
2810
2811 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2812 // strtab holding the name.
2813
2814 template<int size, bool big_endian>
2815 void
2816 Symbol_table::sized_write_symbol(
2817 Sized_symbol<size>* sym,
2818 typename elfcpp::Elf_types<size>::Elf_Addr value,
2819 unsigned int shndx,
2820 const Stringpool* pool,
2821 unsigned char* p) const
2822 {
2823 elfcpp::Sym_write<size, big_endian> osym(p);
2824 osym.put_st_name(pool->get_offset(sym->name()));
2825 osym.put_st_value(value);
2826 // Use a symbol size of zero for undefined symbols from shared libraries.
2827 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2828 osym.put_st_size(0);
2829 else
2830 osym.put_st_size(sym->symsize());
2831 elfcpp::STT type = sym->type();
2832 // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2833 if (type == elfcpp::STT_GNU_IFUNC
2834 && sym->is_from_dynobj())
2835 type = elfcpp::STT_FUNC;
2836 // A version script may have overridden the default binding.
2837 if (sym->is_forced_local())
2838 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2839 else
2840 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), type));
2841 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2842 osym.put_st_shndx(shndx);
2843 }
2844
2845 // Check for unresolved symbols in shared libraries. This is
2846 // controlled by the --allow-shlib-undefined option.
2847
2848 // We only warn about libraries for which we have seen all the
2849 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2850 // which were not seen in this link. If we didn't see a DT_NEEDED
2851 // entry, we aren't going to be able to reliably report whether the
2852 // symbol is undefined.
2853
2854 // We also don't warn about libraries found in a system library
2855 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2856 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2857 // can have undefined references satisfied by ld-linux.so.
2858
2859 inline void
2860 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2861 {
2862 bool dummy;
2863 if (sym->source() == Symbol::FROM_OBJECT
2864 && sym->object()->is_dynamic()
2865 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2866 && sym->binding() != elfcpp::STB_WEAK
2867 && !parameters->options().allow_shlib_undefined()
2868 && !parameters->target().is_defined_by_abi(sym)
2869 && !sym->object()->is_in_system_directory())
2870 {
2871 // A very ugly cast.
2872 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2873 if (!dynobj->has_unknown_needed_entries())
2874 gold_undefined_symbol(sym);
2875 }
2876 }
2877
2878 // Write out a section symbol. Return the update offset.
2879
2880 void
2881 Symbol_table::write_section_symbol(const Output_section *os,
2882 Output_symtab_xindex* symtab_xindex,
2883 Output_file* of,
2884 off_t offset) const
2885 {
2886 switch (parameters->size_and_endianness())
2887 {
2888 #ifdef HAVE_TARGET_32_LITTLE
2889 case Parameters::TARGET_32_LITTLE:
2890 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2891 offset);
2892 break;
2893 #endif
2894 #ifdef HAVE_TARGET_32_BIG
2895 case Parameters::TARGET_32_BIG:
2896 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2897 offset);
2898 break;
2899 #endif
2900 #ifdef HAVE_TARGET_64_LITTLE
2901 case Parameters::TARGET_64_LITTLE:
2902 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2903 offset);
2904 break;
2905 #endif
2906 #ifdef HAVE_TARGET_64_BIG
2907 case Parameters::TARGET_64_BIG:
2908 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2909 offset);
2910 break;
2911 #endif
2912 default:
2913 gold_unreachable();
2914 }
2915 }
2916
2917 // Write out a section symbol, specialized for size and endianness.
2918
2919 template<int size, bool big_endian>
2920 void
2921 Symbol_table::sized_write_section_symbol(const Output_section* os,
2922 Output_symtab_xindex* symtab_xindex,
2923 Output_file* of,
2924 off_t offset) const
2925 {
2926 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2927
2928 unsigned char* pov = of->get_output_view(offset, sym_size);
2929
2930 elfcpp::Sym_write<size, big_endian> osym(pov);
2931 osym.put_st_name(0);
2932 if (parameters->options().relocatable())
2933 osym.put_st_value(0);
2934 else
2935 osym.put_st_value(os->address());
2936 osym.put_st_size(0);
2937 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2938 elfcpp::STT_SECTION));
2939 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2940
2941 unsigned int shndx = os->out_shndx();
2942 if (shndx >= elfcpp::SHN_LORESERVE)
2943 {
2944 symtab_xindex->add(os->symtab_index(), shndx);
2945 shndx = elfcpp::SHN_XINDEX;
2946 }
2947 osym.put_st_shndx(shndx);
2948
2949 of->write_output_view(offset, sym_size, pov);
2950 }
2951
2952 // Print statistical information to stderr. This is used for --stats.
2953
2954 void
2955 Symbol_table::print_stats() const
2956 {
2957 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2958 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2959 program_name, this->table_.size(), this->table_.bucket_count());
2960 #else
2961 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2962 program_name, this->table_.size());
2963 #endif
2964 this->namepool_.print_stats("symbol table stringpool");
2965 }
2966
2967 // We check for ODR violations by looking for symbols with the same
2968 // name for which the debugging information reports that they were
2969 // defined in different source locations. When comparing the source
2970 // location, we consider instances with the same base filename and
2971 // line number to be the same. This is because different object
2972 // files/shared libraries can include the same header file using
2973 // different paths, and we don't want to report an ODR violation in
2974 // that case.
2975
2976 // This struct is used to compare line information, as returned by
2977 // Dwarf_line_info::one_addr2line. It implements a < comparison
2978 // operator used with std::set.
2979
2980 struct Odr_violation_compare
2981 {
2982 bool
2983 operator()(const std::string& s1, const std::string& s2) const
2984 {
2985 std::string::size_type pos1 = s1.rfind('/');
2986 std::string::size_type pos2 = s2.rfind('/');
2987 if (pos1 == std::string::npos
2988 || pos2 == std::string::npos)
2989 return s1 < s2;
2990 return s1.compare(pos1, std::string::npos,
2991 s2, pos2, std::string::npos) < 0;
2992 }
2993 };
2994
2995 // Check candidate_odr_violations_ to find symbols with the same name
2996 // but apparently different definitions (different source-file/line-no).
2997
2998 void
2999 Symbol_table::detect_odr_violations(const Task* task,
3000 const char* output_file_name) const
3001 {
3002 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
3003 it != candidate_odr_violations_.end();
3004 ++it)
3005 {
3006 const char* symbol_name = it->first;
3007 // We use a sorted set so the output is deterministic.
3008 std::set<std::string, Odr_violation_compare> line_nums;
3009
3010 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3011 locs = it->second.begin();
3012 locs != it->second.end();
3013 ++locs)
3014 {
3015 // We need to lock the object in order to read it. This
3016 // means that we have to run in a singleton Task. If we
3017 // want to run this in a general Task for better
3018 // performance, we will need one Task for object, plus
3019 // appropriate locking to ensure that we don't conflict with
3020 // other uses of the object. Also note, one_addr2line is not
3021 // currently thread-safe.
3022 Task_lock_obj<Object> tl(task, locs->object);
3023 // 16 is the size of the object-cache that one_addr2line should use.
3024 std::string lineno = Dwarf_line_info::one_addr2line(
3025 locs->object, locs->shndx, locs->offset, 16);
3026 if (!lineno.empty())
3027 line_nums.insert(lineno);
3028 }
3029
3030 if (line_nums.size() > 1)
3031 {
3032 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3033 "places (possible ODR violation):"),
3034 output_file_name, demangle(symbol_name).c_str());
3035 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
3036 it2 != line_nums.end();
3037 ++it2)
3038 fprintf(stderr, " %s\n", it2->c_str());
3039 }
3040 }
3041 // We only call one_addr2line() in this function, so we can clear its cache.
3042 Dwarf_line_info::clear_addr2line_cache();
3043 }
3044
3045 // Warnings functions.
3046
3047 // Add a new warning.
3048
3049 void
3050 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3051 const std::string& warning)
3052 {
3053 name = symtab->canonicalize_name(name);
3054 this->warnings_[name].set(obj, warning);
3055 }
3056
3057 // Look through the warnings and mark the symbols for which we should
3058 // warn. This is called during Layout::finalize when we know the
3059 // sources for all the symbols.
3060
3061 void
3062 Warnings::note_warnings(Symbol_table* symtab)
3063 {
3064 for (Warning_table::iterator p = this->warnings_.begin();
3065 p != this->warnings_.end();
3066 ++p)
3067 {
3068 Symbol* sym = symtab->lookup(p->first, NULL);
3069 if (sym != NULL
3070 && sym->source() == Symbol::FROM_OBJECT
3071 && sym->object() == p->second.object)
3072 sym->set_has_warning();
3073 }
3074 }
3075
3076 // Issue a warning. This is called when we see a relocation against a
3077 // symbol for which has a warning.
3078
3079 template<int size, bool big_endian>
3080 void
3081 Warnings::issue_warning(const Symbol* sym,
3082 const Relocate_info<size, big_endian>* relinfo,
3083 size_t relnum, off_t reloffset) const
3084 {
3085 gold_assert(sym->has_warning());
3086 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3087 gold_assert(p != this->warnings_.end());
3088 gold_warning_at_location(relinfo, relnum, reloffset,
3089 "%s", p->second.text.c_str());
3090 }
3091
3092 // Instantiate the templates we need. We could use the configure
3093 // script to restrict this to only the ones needed for implemented
3094 // targets.
3095
3096 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3097 template
3098 void
3099 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3100 #endif
3101
3102 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3103 template
3104 void
3105 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3106 #endif
3107
3108 #ifdef HAVE_TARGET_32_LITTLE
3109 template
3110 void
3111 Symbol_table::add_from_relobj<32, false>(
3112 Sized_relobj<32, false>* relobj,
3113 const unsigned char* syms,
3114 size_t count,
3115 size_t symndx_offset,
3116 const char* sym_names,
3117 size_t sym_name_size,
3118 Sized_relobj<32, false>::Symbols* sympointers,
3119 size_t* defined);
3120 #endif
3121
3122 #ifdef HAVE_TARGET_32_BIG
3123 template
3124 void
3125 Symbol_table::add_from_relobj<32, true>(
3126 Sized_relobj<32, true>* relobj,
3127 const unsigned char* syms,
3128 size_t count,
3129 size_t symndx_offset,
3130 const char* sym_names,
3131 size_t sym_name_size,
3132 Sized_relobj<32, true>::Symbols* sympointers,
3133 size_t* defined);
3134 #endif
3135
3136 #ifdef HAVE_TARGET_64_LITTLE
3137 template
3138 void
3139 Symbol_table::add_from_relobj<64, false>(
3140 Sized_relobj<64, false>* relobj,
3141 const unsigned char* syms,
3142 size_t count,
3143 size_t symndx_offset,
3144 const char* sym_names,
3145 size_t sym_name_size,
3146 Sized_relobj<64, false>::Symbols* sympointers,
3147 size_t* defined);
3148 #endif
3149
3150 #ifdef HAVE_TARGET_64_BIG
3151 template
3152 void
3153 Symbol_table::add_from_relobj<64, true>(
3154 Sized_relobj<64, true>* relobj,
3155 const unsigned char* syms,
3156 size_t count,
3157 size_t symndx_offset,
3158 const char* sym_names,
3159 size_t sym_name_size,
3160 Sized_relobj<64, true>::Symbols* sympointers,
3161 size_t* defined);
3162 #endif
3163
3164 #ifdef HAVE_TARGET_32_LITTLE
3165 template
3166 Symbol*
3167 Symbol_table::add_from_pluginobj<32, false>(
3168 Sized_pluginobj<32, false>* obj,
3169 const char* name,
3170 const char* ver,
3171 elfcpp::Sym<32, false>* sym);
3172 #endif
3173
3174 #ifdef HAVE_TARGET_32_BIG
3175 template
3176 Symbol*
3177 Symbol_table::add_from_pluginobj<32, true>(
3178 Sized_pluginobj<32, true>* obj,
3179 const char* name,
3180 const char* ver,
3181 elfcpp::Sym<32, true>* sym);
3182 #endif
3183
3184 #ifdef HAVE_TARGET_64_LITTLE
3185 template
3186 Symbol*
3187 Symbol_table::add_from_pluginobj<64, false>(
3188 Sized_pluginobj<64, false>* obj,
3189 const char* name,
3190 const char* ver,
3191 elfcpp::Sym<64, false>* sym);
3192 #endif
3193
3194 #ifdef HAVE_TARGET_64_BIG
3195 template
3196 Symbol*
3197 Symbol_table::add_from_pluginobj<64, true>(
3198 Sized_pluginobj<64, true>* obj,
3199 const char* name,
3200 const char* ver,
3201 elfcpp::Sym<64, true>* sym);
3202 #endif
3203
3204 #ifdef HAVE_TARGET_32_LITTLE
3205 template
3206 void
3207 Symbol_table::add_from_dynobj<32, false>(
3208 Sized_dynobj<32, false>* dynobj,
3209 const unsigned char* syms,
3210 size_t count,
3211 const char* sym_names,
3212 size_t sym_name_size,
3213 const unsigned char* versym,
3214 size_t versym_size,
3215 const std::vector<const char*>* version_map,
3216 Sized_relobj<32, false>::Symbols* sympointers,
3217 size_t* defined);
3218 #endif
3219
3220 #ifdef HAVE_TARGET_32_BIG
3221 template
3222 void
3223 Symbol_table::add_from_dynobj<32, true>(
3224 Sized_dynobj<32, true>* dynobj,
3225 const unsigned char* syms,
3226 size_t count,
3227 const char* sym_names,
3228 size_t sym_name_size,
3229 const unsigned char* versym,
3230 size_t versym_size,
3231 const std::vector<const char*>* version_map,
3232 Sized_relobj<32, true>::Symbols* sympointers,
3233 size_t* defined);
3234 #endif
3235
3236 #ifdef HAVE_TARGET_64_LITTLE
3237 template
3238 void
3239 Symbol_table::add_from_dynobj<64, false>(
3240 Sized_dynobj<64, false>* dynobj,
3241 const unsigned char* syms,
3242 size_t count,
3243 const char* sym_names,
3244 size_t sym_name_size,
3245 const unsigned char* versym,
3246 size_t versym_size,
3247 const std::vector<const char*>* version_map,
3248 Sized_relobj<64, false>::Symbols* sympointers,
3249 size_t* defined);
3250 #endif
3251
3252 #ifdef HAVE_TARGET_64_BIG
3253 template
3254 void
3255 Symbol_table::add_from_dynobj<64, true>(
3256 Sized_dynobj<64, true>* dynobj,
3257 const unsigned char* syms,
3258 size_t count,
3259 const char* sym_names,
3260 size_t sym_name_size,
3261 const unsigned char* versym,
3262 size_t versym_size,
3263 const std::vector<const char*>* version_map,
3264 Sized_relobj<64, true>::Symbols* sympointers,
3265 size_t* defined);
3266 #endif
3267
3268 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3269 template
3270 void
3271 Symbol_table::define_with_copy_reloc<32>(
3272 Sized_symbol<32>* sym,
3273 Output_data* posd,
3274 elfcpp::Elf_types<32>::Elf_Addr value);
3275 #endif
3276
3277 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3278 template
3279 void
3280 Symbol_table::define_with_copy_reloc<64>(
3281 Sized_symbol<64>* sym,
3282 Output_data* posd,
3283 elfcpp::Elf_types<64>::Elf_Addr value);
3284 #endif
3285
3286 #ifdef HAVE_TARGET_32_LITTLE
3287 template
3288 void
3289 Warnings::issue_warning<32, false>(const Symbol* sym,
3290 const Relocate_info<32, false>* relinfo,
3291 size_t relnum, off_t reloffset) const;
3292 #endif
3293
3294 #ifdef HAVE_TARGET_32_BIG
3295 template
3296 void
3297 Warnings::issue_warning<32, true>(const Symbol* sym,
3298 const Relocate_info<32, true>* relinfo,
3299 size_t relnum, off_t reloffset) const;
3300 #endif
3301
3302 #ifdef HAVE_TARGET_64_LITTLE
3303 template
3304 void
3305 Warnings::issue_warning<64, false>(const Symbol* sym,
3306 const Relocate_info<64, false>* relinfo,
3307 size_t relnum, off_t reloffset) const;
3308 #endif
3309
3310 #ifdef HAVE_TARGET_64_BIG
3311 template
3312 void
3313 Warnings::issue_warning<64, true>(const Symbol* sym,
3314 const Relocate_info<64, true>* relinfo,
3315 size_t relnum, off_t reloffset) const;
3316 #endif
3317
3318 } // End namespace gold.
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