7e8a89021d979148128ca1aa0083f84ae8f6fd25
[deliverable/binutils-gdb.git] / gold / symtab.cc
1 // symtab.cc -- the gold symbol table
2
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cstring>
26 #include <stdint.h>
27 #include <algorithm>
28 #include <set>
29 #include <string>
30 #include <utility>
31 #include "demangle.h"
32
33 #include "gc.h"
34 #include "object.h"
35 #include "dwarf_reader.h"
36 #include "dynobj.h"
37 #include "output.h"
38 #include "target.h"
39 #include "workqueue.h"
40 #include "symtab.h"
41 #include "demangle.h" // needed for --dynamic-list-cpp-new
42 #include "plugin.h"
43
44 namespace gold
45 {
46
47 // Class Symbol.
48
49 // Initialize fields in Symbol. This initializes everything except u_
50 // and source_.
51
52 void
53 Symbol::init_fields(const char* name, const char* version,
54 elfcpp::STT type, elfcpp::STB binding,
55 elfcpp::STV visibility, unsigned char nonvis)
56 {
57 this->name_ = name;
58 this->version_ = version;
59 this->symtab_index_ = 0;
60 this->dynsym_index_ = 0;
61 this->got_offsets_.init();
62 this->plt_offset_ = 0;
63 this->type_ = type;
64 this->binding_ = binding;
65 this->visibility_ = visibility;
66 this->nonvis_ = nonvis;
67 this->is_target_special_ = false;
68 this->is_def_ = false;
69 this->is_forwarder_ = false;
70 this->has_alias_ = false;
71 this->needs_dynsym_entry_ = false;
72 this->in_reg_ = false;
73 this->in_dyn_ = false;
74 this->has_plt_offset_ = false;
75 this->has_warning_ = false;
76 this->is_copied_from_dynobj_ = false;
77 this->is_forced_local_ = false;
78 this->is_ordinary_shndx_ = false;
79 this->in_real_elf_ = false;
80 }
81
82 // Return the demangled version of the symbol's name, but only
83 // if the --demangle flag was set.
84
85 static std::string
86 demangle(const char* name)
87 {
88 if (!parameters->options().do_demangle())
89 return name;
90
91 // cplus_demangle allocates memory for the result it returns,
92 // and returns NULL if the name is already demangled.
93 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
94 if (demangled_name == NULL)
95 return name;
96
97 std::string retval(demangled_name);
98 free(demangled_name);
99 return retval;
100 }
101
102 std::string
103 Symbol::demangled_name() const
104 {
105 return demangle(this->name());
106 }
107
108 // Initialize the fields in the base class Symbol for SYM in OBJECT.
109
110 template<int size, bool big_endian>
111 void
112 Symbol::init_base_object(const char* name, const char* version, Object* object,
113 const elfcpp::Sym<size, big_endian>& sym,
114 unsigned int st_shndx, bool is_ordinary)
115 {
116 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
117 sym.get_st_visibility(), sym.get_st_nonvis());
118 this->u_.from_object.object = object;
119 this->u_.from_object.shndx = st_shndx;
120 this->is_ordinary_shndx_ = is_ordinary;
121 this->source_ = FROM_OBJECT;
122 this->in_reg_ = !object->is_dynamic();
123 this->in_dyn_ = object->is_dynamic();
124 this->in_real_elf_ = object->pluginobj() == NULL;
125 }
126
127 // Initialize the fields in the base class Symbol for a symbol defined
128 // in an Output_data.
129
130 void
131 Symbol::init_base_output_data(const char* name, const char* version,
132 Output_data* od, elfcpp::STT type,
133 elfcpp::STB binding, elfcpp::STV visibility,
134 unsigned char nonvis, bool offset_is_from_end)
135 {
136 this->init_fields(name, version, type, binding, visibility, nonvis);
137 this->u_.in_output_data.output_data = od;
138 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
139 this->source_ = IN_OUTPUT_DATA;
140 this->in_reg_ = true;
141 this->in_real_elf_ = true;
142 }
143
144 // Initialize the fields in the base class Symbol for a symbol defined
145 // in an Output_segment.
146
147 void
148 Symbol::init_base_output_segment(const char* name, const char* version,
149 Output_segment* os, elfcpp::STT type,
150 elfcpp::STB binding, elfcpp::STV visibility,
151 unsigned char nonvis,
152 Segment_offset_base offset_base)
153 {
154 this->init_fields(name, version, type, binding, visibility, nonvis);
155 this->u_.in_output_segment.output_segment = os;
156 this->u_.in_output_segment.offset_base = offset_base;
157 this->source_ = IN_OUTPUT_SEGMENT;
158 this->in_reg_ = true;
159 this->in_real_elf_ = true;
160 }
161
162 // Initialize the fields in the base class Symbol for a symbol defined
163 // as a constant.
164
165 void
166 Symbol::init_base_constant(const char* name, const char* version,
167 elfcpp::STT type, elfcpp::STB binding,
168 elfcpp::STV visibility, unsigned char nonvis)
169 {
170 this->init_fields(name, version, type, binding, visibility, nonvis);
171 this->source_ = IS_CONSTANT;
172 this->in_reg_ = true;
173 this->in_real_elf_ = true;
174 }
175
176 // Initialize the fields in the base class Symbol for an undefined
177 // symbol.
178
179 void
180 Symbol::init_base_undefined(const char* name, const char* version,
181 elfcpp::STT type, elfcpp::STB binding,
182 elfcpp::STV visibility, unsigned char nonvis)
183 {
184 this->init_fields(name, version, type, binding, visibility, nonvis);
185 this->dynsym_index_ = -1U;
186 this->source_ = IS_UNDEFINED;
187 this->in_reg_ = true;
188 this->in_real_elf_ = true;
189 }
190
191 // Allocate a common symbol in the base.
192
193 void
194 Symbol::allocate_base_common(Output_data* od)
195 {
196 gold_assert(this->is_common());
197 this->source_ = IN_OUTPUT_DATA;
198 this->u_.in_output_data.output_data = od;
199 this->u_.in_output_data.offset_is_from_end = false;
200 }
201
202 // Initialize the fields in Sized_symbol for SYM in OBJECT.
203
204 template<int size>
205 template<bool big_endian>
206 void
207 Sized_symbol<size>::init_object(const char* name, const char* version,
208 Object* object,
209 const elfcpp::Sym<size, big_endian>& sym,
210 unsigned int st_shndx, bool is_ordinary)
211 {
212 this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
213 this->value_ = sym.get_st_value();
214 this->symsize_ = sym.get_st_size();
215 }
216
217 // Initialize the fields in Sized_symbol for a symbol defined in an
218 // Output_data.
219
220 template<int size>
221 void
222 Sized_symbol<size>::init_output_data(const char* name, const char* version,
223 Output_data* od, Value_type value,
224 Size_type symsize, elfcpp::STT type,
225 elfcpp::STB binding,
226 elfcpp::STV visibility,
227 unsigned char nonvis,
228 bool offset_is_from_end)
229 {
230 this->init_base_output_data(name, version, od, type, binding, visibility,
231 nonvis, offset_is_from_end);
232 this->value_ = value;
233 this->symsize_ = symsize;
234 }
235
236 // Initialize the fields in Sized_symbol for a symbol defined in an
237 // Output_segment.
238
239 template<int size>
240 void
241 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
242 Output_segment* os, Value_type value,
243 Size_type symsize, elfcpp::STT type,
244 elfcpp::STB binding,
245 elfcpp::STV visibility,
246 unsigned char nonvis,
247 Segment_offset_base offset_base)
248 {
249 this->init_base_output_segment(name, version, os, type, binding, visibility,
250 nonvis, offset_base);
251 this->value_ = value;
252 this->symsize_ = symsize;
253 }
254
255 // Initialize the fields in Sized_symbol for a symbol defined as a
256 // constant.
257
258 template<int size>
259 void
260 Sized_symbol<size>::init_constant(const char* name, const char* version,
261 Value_type value, Size_type symsize,
262 elfcpp::STT type, elfcpp::STB binding,
263 elfcpp::STV visibility, unsigned char nonvis)
264 {
265 this->init_base_constant(name, version, type, binding, visibility, nonvis);
266 this->value_ = value;
267 this->symsize_ = symsize;
268 }
269
270 // Initialize the fields in Sized_symbol for an undefined symbol.
271
272 template<int size>
273 void
274 Sized_symbol<size>::init_undefined(const char* name, const char* version,
275 elfcpp::STT type, elfcpp::STB binding,
276 elfcpp::STV visibility, unsigned char nonvis)
277 {
278 this->init_base_undefined(name, version, type, binding, visibility, nonvis);
279 this->value_ = 0;
280 this->symsize_ = 0;
281 }
282
283 // Return true if SHNDX represents a common symbol.
284
285 bool
286 Symbol::is_common_shndx(unsigned int shndx)
287 {
288 return (shndx == elfcpp::SHN_COMMON
289 || shndx == parameters->target().small_common_shndx()
290 || shndx == parameters->target().large_common_shndx());
291 }
292
293 // Allocate a common symbol.
294
295 template<int size>
296 void
297 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
298 {
299 this->allocate_base_common(od);
300 this->value_ = value;
301 }
302
303 // The ""'s around str ensure str is a string literal, so sizeof works.
304 #define strprefix(var, str) (strncmp(var, str, sizeof("" str "") - 1) == 0)
305
306 // Return true if this symbol should be added to the dynamic symbol
307 // table.
308
309 inline bool
310 Symbol::should_add_dynsym_entry() const
311 {
312 // If the symbol is used by a dynamic relocation, we need to add it.
313 if (this->needs_dynsym_entry())
314 return true;
315
316 // If this symbol's section is not added, the symbol need not be added.
317 // The section may have been GCed. Note that export_dynamic is being
318 // overridden here. This should not be done for shared objects.
319 if (parameters->options().gc_sections()
320 && !parameters->options().shared()
321 && this->source() == Symbol::FROM_OBJECT
322 && !this->object()->is_dynamic())
323 {
324 Relobj* relobj = static_cast<Relobj*>(this->object());
325 bool is_ordinary;
326 unsigned int shndx = this->shndx(&is_ordinary);
327 if (is_ordinary && shndx != elfcpp::SHN_UNDEF
328 && !relobj->is_section_included(shndx))
329 return false;
330 }
331
332 // If the symbol was forced local in a version script, do not add it.
333 if (this->is_forced_local())
334 return false;
335
336 // If the symbol was forced dynamic in a --dynamic-list file, add it.
337 if (parameters->options().in_dynamic_list(this->name()))
338 return true;
339
340 // If dynamic-list-data was specified, add any STT_OBJECT.
341 if (parameters->options().dynamic_list_data()
342 && !this->is_from_dynobj()
343 && this->type() == elfcpp::STT_OBJECT)
344 return true;
345
346 // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
347 // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
348 if ((parameters->options().dynamic_list_cpp_new()
349 || parameters->options().dynamic_list_cpp_typeinfo())
350 && !this->is_from_dynobj())
351 {
352 // TODO(csilvers): We could probably figure out if we're an operator
353 // new/delete or typeinfo without the need to demangle.
354 char* demangled_name = cplus_demangle(this->name(),
355 DMGL_ANSI | DMGL_PARAMS);
356 if (demangled_name == NULL)
357 {
358 // Not a C++ symbol, so it can't satisfy these flags
359 }
360 else if (parameters->options().dynamic_list_cpp_new()
361 && (strprefix(demangled_name, "operator new")
362 || strprefix(demangled_name, "operator delete")))
363 {
364 free(demangled_name);
365 return true;
366 }
367 else if (parameters->options().dynamic_list_cpp_typeinfo()
368 && (strprefix(demangled_name, "typeinfo name for")
369 || strprefix(demangled_name, "typeinfo for")))
370 {
371 free(demangled_name);
372 return true;
373 }
374 else
375 free(demangled_name);
376 }
377
378 // If exporting all symbols or building a shared library,
379 // and the symbol is defined in a regular object and is
380 // externally visible, we need to add it.
381 if ((parameters->options().export_dynamic() || parameters->options().shared())
382 && !this->is_from_dynobj()
383 && this->is_externally_visible())
384 return true;
385
386 return false;
387 }
388
389 // Return true if the final value of this symbol is known at link
390 // time.
391
392 bool
393 Symbol::final_value_is_known() const
394 {
395 // If we are not generating an executable, then no final values are
396 // known, since they will change at runtime.
397 if (parameters->options().output_is_position_independent()
398 || parameters->options().relocatable())
399 return false;
400
401 // If the symbol is not from an object file, and is not undefined,
402 // then it is defined, and known.
403 if (this->source_ != FROM_OBJECT)
404 {
405 if (this->source_ != IS_UNDEFINED)
406 return true;
407 }
408 else
409 {
410 // If the symbol is from a dynamic object, then the final value
411 // is not known.
412 if (this->object()->is_dynamic())
413 return false;
414
415 // If the symbol is not undefined (it is defined or common),
416 // then the final value is known.
417 if (!this->is_undefined())
418 return true;
419 }
420
421 // If the symbol is undefined, then whether the final value is known
422 // depends on whether we are doing a static link. If we are doing a
423 // dynamic link, then the final value could be filled in at runtime.
424 // This could reasonably be the case for a weak undefined symbol.
425 return parameters->doing_static_link();
426 }
427
428 // Return the output section where this symbol is defined.
429
430 Output_section*
431 Symbol::output_section() const
432 {
433 switch (this->source_)
434 {
435 case FROM_OBJECT:
436 {
437 unsigned int shndx = this->u_.from_object.shndx;
438 if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
439 {
440 gold_assert(!this->u_.from_object.object->is_dynamic());
441 gold_assert(this->u_.from_object.object->pluginobj() == NULL);
442 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
443 return relobj->output_section(shndx);
444 }
445 return NULL;
446 }
447
448 case IN_OUTPUT_DATA:
449 return this->u_.in_output_data.output_data->output_section();
450
451 case IN_OUTPUT_SEGMENT:
452 case IS_CONSTANT:
453 case IS_UNDEFINED:
454 return NULL;
455
456 default:
457 gold_unreachable();
458 }
459 }
460
461 // Set the symbol's output section. This is used for symbols defined
462 // in scripts. This should only be called after the symbol table has
463 // been finalized.
464
465 void
466 Symbol::set_output_section(Output_section* os)
467 {
468 switch (this->source_)
469 {
470 case FROM_OBJECT:
471 case IN_OUTPUT_DATA:
472 gold_assert(this->output_section() == os);
473 break;
474 case IS_CONSTANT:
475 this->source_ = IN_OUTPUT_DATA;
476 this->u_.in_output_data.output_data = os;
477 this->u_.in_output_data.offset_is_from_end = false;
478 break;
479 case IN_OUTPUT_SEGMENT:
480 case IS_UNDEFINED:
481 default:
482 gold_unreachable();
483 }
484 }
485
486 // Class Symbol_table.
487
488 Symbol_table::Symbol_table(unsigned int count,
489 const Version_script_info& version_script)
490 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
491 forwarders_(), commons_(), tls_commons_(), small_commons_(),
492 large_commons_(), forced_locals_(), warnings_(),
493 version_script_(version_script), gc_(NULL), icf_(NULL)
494 {
495 namepool_.reserve(count);
496 }
497
498 Symbol_table::~Symbol_table()
499 {
500 }
501
502 // The hash function. The key values are Stringpool keys.
503
504 inline size_t
505 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
506 {
507 return key.first ^ key.second;
508 }
509
510 // The symbol table key equality function. This is called with
511 // Stringpool keys.
512
513 inline bool
514 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
515 const Symbol_table_key& k2) const
516 {
517 return k1.first == k2.first && k1.second == k2.second;
518 }
519
520 bool
521 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
522 {
523 return (parameters->options().icf_enabled()
524 && this->icf_->is_section_folded(obj, shndx));
525 }
526
527 // For symbols that have been listed with -u option, add them to the
528 // work list to avoid gc'ing them.
529
530 void
531 Symbol_table::gc_mark_undef_symbols()
532 {
533 for (options::String_set::const_iterator p =
534 parameters->options().undefined_begin();
535 p != parameters->options().undefined_end();
536 ++p)
537 {
538 const char* name = p->c_str();
539 Symbol* sym = this->lookup(name);
540 gold_assert (sym != NULL);
541 if (sym->source() == Symbol::FROM_OBJECT
542 && !sym->object()->is_dynamic())
543 {
544 Relobj* obj = static_cast<Relobj*>(sym->object());
545 bool is_ordinary;
546 unsigned int shndx = sym->shndx(&is_ordinary);
547 if (is_ordinary)
548 {
549 gold_assert(this->gc_ != NULL);
550 this->gc_->worklist().push(Section_id(obj, shndx));
551 }
552 }
553 }
554 }
555
556 void
557 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
558 {
559 if (!sym->is_from_dynobj()
560 && sym->is_externally_visible())
561 {
562 //Add the object and section to the work list.
563 Relobj* obj = static_cast<Relobj*>(sym->object());
564 bool is_ordinary;
565 unsigned int shndx = sym->shndx(&is_ordinary);
566 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
567 {
568 gold_assert(this->gc_!= NULL);
569 this->gc_->worklist().push(Section_id(obj, shndx));
570 }
571 }
572 }
573
574 // When doing garbage collection, keep symbols that have been seen in
575 // dynamic objects.
576 inline void
577 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
578 {
579 if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
580 && !sym->object()->is_dynamic())
581 {
582 Relobj *obj = static_cast<Relobj*>(sym->object());
583 bool is_ordinary;
584 unsigned int shndx = sym->shndx(&is_ordinary);
585 if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
586 {
587 gold_assert(this->gc_ != NULL);
588 this->gc_->worklist().push(Section_id(obj, shndx));
589 }
590 }
591 }
592
593 // Make TO a symbol which forwards to FROM.
594
595 void
596 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
597 {
598 gold_assert(from != to);
599 gold_assert(!from->is_forwarder() && !to->is_forwarder());
600 this->forwarders_[from] = to;
601 from->set_forwarder();
602 }
603
604 // Resolve the forwards from FROM, returning the real symbol.
605
606 Symbol*
607 Symbol_table::resolve_forwards(const Symbol* from) const
608 {
609 gold_assert(from->is_forwarder());
610 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
611 this->forwarders_.find(from);
612 gold_assert(p != this->forwarders_.end());
613 return p->second;
614 }
615
616 // Look up a symbol by name.
617
618 Symbol*
619 Symbol_table::lookup(const char* name, const char* version) const
620 {
621 Stringpool::Key name_key;
622 name = this->namepool_.find(name, &name_key);
623 if (name == NULL)
624 return NULL;
625
626 Stringpool::Key version_key = 0;
627 if (version != NULL)
628 {
629 version = this->namepool_.find(version, &version_key);
630 if (version == NULL)
631 return NULL;
632 }
633
634 Symbol_table_key key(name_key, version_key);
635 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
636 if (p == this->table_.end())
637 return NULL;
638 return p->second;
639 }
640
641 // Resolve a Symbol with another Symbol. This is only used in the
642 // unusual case where there are references to both an unversioned
643 // symbol and a symbol with a version, and we then discover that that
644 // version is the default version. Because this is unusual, we do
645 // this the slow way, by converting back to an ELF symbol.
646
647 template<int size, bool big_endian>
648 void
649 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
650 {
651 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
652 elfcpp::Sym_write<size, big_endian> esym(buf);
653 // We don't bother to set the st_name or the st_shndx field.
654 esym.put_st_value(from->value());
655 esym.put_st_size(from->symsize());
656 esym.put_st_info(from->binding(), from->type());
657 esym.put_st_other(from->visibility(), from->nonvis());
658 bool is_ordinary;
659 unsigned int shndx = from->shndx(&is_ordinary);
660 this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
661 from->version());
662 if (from->in_reg())
663 to->set_in_reg();
664 if (from->in_dyn())
665 to->set_in_dyn();
666 if (parameters->options().gc_sections())
667 this->gc_mark_dyn_syms(to);
668 }
669
670 // Record that a symbol is forced to be local by a version script or
671 // by visibility.
672
673 void
674 Symbol_table::force_local(Symbol* sym)
675 {
676 if (!sym->is_defined() && !sym->is_common())
677 return;
678 if (sym->is_forced_local())
679 {
680 // We already got this one.
681 return;
682 }
683 sym->set_is_forced_local();
684 this->forced_locals_.push_back(sym);
685 }
686
687 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
688 // is only called for undefined symbols, when at least one --wrap
689 // option was used.
690
691 const char*
692 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
693 {
694 // For some targets, we need to ignore a specific character when
695 // wrapping, and add it back later.
696 char prefix = '\0';
697 if (name[0] == parameters->target().wrap_char())
698 {
699 prefix = name[0];
700 ++name;
701 }
702
703 if (parameters->options().is_wrap(name))
704 {
705 // Turn NAME into __wrap_NAME.
706 std::string s;
707 if (prefix != '\0')
708 s += prefix;
709 s += "__wrap_";
710 s += name;
711
712 // This will give us both the old and new name in NAMEPOOL_, but
713 // that is OK. Only the versions we need will wind up in the
714 // real string table in the output file.
715 return this->namepool_.add(s.c_str(), true, name_key);
716 }
717
718 const char* const real_prefix = "__real_";
719 const size_t real_prefix_length = strlen(real_prefix);
720 if (strncmp(name, real_prefix, real_prefix_length) == 0
721 && parameters->options().is_wrap(name + real_prefix_length))
722 {
723 // Turn __real_NAME into NAME.
724 std::string s;
725 if (prefix != '\0')
726 s += prefix;
727 s += name + real_prefix_length;
728 return this->namepool_.add(s.c_str(), true, name_key);
729 }
730
731 return name;
732 }
733
734 // This is called when we see a symbol NAME/VERSION, and the symbol
735 // already exists in the symbol table, and VERSION is marked as being
736 // the default version. SYM is the NAME/VERSION symbol we just added.
737 // DEFAULT_IS_NEW is true if this is the first time we have seen the
738 // symbol NAME/NULL. PDEF points to the entry for NAME/NULL.
739
740 template<int size, bool big_endian>
741 void
742 Symbol_table::define_default_version(Sized_symbol<size>* sym,
743 bool default_is_new,
744 Symbol_table_type::iterator pdef)
745 {
746 if (default_is_new)
747 {
748 // This is the first time we have seen NAME/NULL. Make
749 // NAME/NULL point to NAME/VERSION, and mark SYM as the default
750 // version.
751 pdef->second = sym;
752 sym->set_is_default();
753 }
754 else if (pdef->second == sym)
755 {
756 // NAME/NULL already points to NAME/VERSION. Don't mark the
757 // symbol as the default if it is not already the default.
758 }
759 else
760 {
761 // This is the unfortunate case where we already have entries
762 // for both NAME/VERSION and NAME/NULL. We now see a symbol
763 // NAME/VERSION where VERSION is the default version. We have
764 // already resolved this new symbol with the existing
765 // NAME/VERSION symbol.
766
767 // It's possible that NAME/NULL and NAME/VERSION are both
768 // defined in regular objects. This can only happen if one
769 // object file defines foo and another defines foo@@ver. This
770 // is somewhat obscure, but we call it a multiple definition
771 // error.
772
773 // It's possible that NAME/NULL actually has a version, in which
774 // case it won't be the same as VERSION. This happens with
775 // ver_test_7.so in the testsuite for the symbol t2_2. We see
776 // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL. We
777 // then see an unadorned t2_2 in an object file and give it
778 // version VER1 from the version script. This looks like a
779 // default definition for VER1, so it looks like we should merge
780 // t2_2/NULL with t2_2/VER1. That doesn't make sense, but it's
781 // not obvious that this is an error, either. So we just punt.
782
783 // If one of the symbols has non-default visibility, and the
784 // other is defined in a shared object, then they are different
785 // symbols.
786
787 // Otherwise, we just resolve the symbols as though they were
788 // the same.
789
790 if (pdef->second->version() != NULL)
791 gold_assert(pdef->second->version() != sym->version());
792 else if (sym->visibility() != elfcpp::STV_DEFAULT
793 && pdef->second->is_from_dynobj())
794 ;
795 else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
796 && sym->is_from_dynobj())
797 ;
798 else
799 {
800 const Sized_symbol<size>* symdef;
801 symdef = this->get_sized_symbol<size>(pdef->second);
802 Symbol_table::resolve<size, big_endian>(sym, symdef);
803 this->make_forwarder(pdef->second, sym);
804 pdef->second = sym;
805 sym->set_is_default();
806 }
807 }
808 }
809
810 // Add one symbol from OBJECT to the symbol table. NAME is symbol
811 // name and VERSION is the version; both are canonicalized. DEF is
812 // whether this is the default version. ST_SHNDX is the symbol's
813 // section index; IS_ORDINARY is whether this is a normal section
814 // rather than a special code.
815
816 // If DEF is true, then this is the definition of a default version of
817 // a symbol. That means that any lookup of NAME/NULL and any lookup
818 // of NAME/VERSION should always return the same symbol. This is
819 // obvious for references, but in particular we want to do this for
820 // definitions: overriding NAME/NULL should also override
821 // NAME/VERSION. If we don't do that, it would be very hard to
822 // override functions in a shared library which uses versioning.
823
824 // We implement this by simply making both entries in the hash table
825 // point to the same Symbol structure. That is easy enough if this is
826 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
827 // that we have seen both already, in which case they will both have
828 // independent entries in the symbol table. We can't simply change
829 // the symbol table entry, because we have pointers to the entries
830 // attached to the object files. So we mark the entry attached to the
831 // object file as a forwarder, and record it in the forwarders_ map.
832 // Note that entries in the hash table will never be marked as
833 // forwarders.
834 //
835 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
836 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
837 // for a special section code. ST_SHNDX may be modified if the symbol
838 // is defined in a section being discarded.
839
840 template<int size, bool big_endian>
841 Sized_symbol<size>*
842 Symbol_table::add_from_object(Object* object,
843 const char *name,
844 Stringpool::Key name_key,
845 const char *version,
846 Stringpool::Key version_key,
847 bool def,
848 const elfcpp::Sym<size, big_endian>& sym,
849 unsigned int st_shndx,
850 bool is_ordinary,
851 unsigned int orig_st_shndx)
852 {
853 // Print a message if this symbol is being traced.
854 if (parameters->options().is_trace_symbol(name))
855 {
856 if (orig_st_shndx == elfcpp::SHN_UNDEF)
857 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
858 else
859 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
860 }
861
862 // For an undefined symbol, we may need to adjust the name using
863 // --wrap.
864 if (orig_st_shndx == elfcpp::SHN_UNDEF
865 && parameters->options().any_wrap())
866 {
867 const char* wrap_name = this->wrap_symbol(name, &name_key);
868 if (wrap_name != name)
869 {
870 // If we see a reference to malloc with version GLIBC_2.0,
871 // and we turn it into a reference to __wrap_malloc, then we
872 // discard the version number. Otherwise the user would be
873 // required to specify the correct version for
874 // __wrap_malloc.
875 version = NULL;
876 version_key = 0;
877 name = wrap_name;
878 }
879 }
880
881 Symbol* const snull = NULL;
882 std::pair<typename Symbol_table_type::iterator, bool> ins =
883 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
884 snull));
885
886 std::pair<typename Symbol_table_type::iterator, bool> insdef =
887 std::make_pair(this->table_.end(), false);
888 if (def)
889 {
890 const Stringpool::Key vnull_key = 0;
891 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
892 vnull_key),
893 snull));
894 }
895
896 // ins.first: an iterator, which is a pointer to a pair.
897 // ins.first->first: the key (a pair of name and version).
898 // ins.first->second: the value (Symbol*).
899 // ins.second: true if new entry was inserted, false if not.
900
901 Sized_symbol<size>* ret;
902 bool was_undefined;
903 bool was_common;
904 if (!ins.second)
905 {
906 // We already have an entry for NAME/VERSION.
907 ret = this->get_sized_symbol<size>(ins.first->second);
908 gold_assert(ret != NULL);
909
910 was_undefined = ret->is_undefined();
911 was_common = ret->is_common();
912
913 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
914 version);
915 if (parameters->options().gc_sections())
916 this->gc_mark_dyn_syms(ret);
917
918 if (def)
919 this->define_default_version<size, big_endian>(ret, insdef.second,
920 insdef.first);
921 }
922 else
923 {
924 // This is the first time we have seen NAME/VERSION.
925 gold_assert(ins.first->second == NULL);
926
927 if (def && !insdef.second)
928 {
929 // We already have an entry for NAME/NULL. If we override
930 // it, then change it to NAME/VERSION.
931 ret = this->get_sized_symbol<size>(insdef.first->second);
932
933 was_undefined = ret->is_undefined();
934 was_common = ret->is_common();
935
936 this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
937 version);
938 if (parameters->options().gc_sections())
939 this->gc_mark_dyn_syms(ret);
940 ins.first->second = ret;
941 }
942 else
943 {
944 was_undefined = false;
945 was_common = false;
946
947 Sized_target<size, big_endian>* target =
948 parameters->sized_target<size, big_endian>();
949 if (!target->has_make_symbol())
950 ret = new Sized_symbol<size>();
951 else
952 {
953 ret = target->make_symbol();
954 if (ret == NULL)
955 {
956 // This means that we don't want a symbol table
957 // entry after all.
958 if (!def)
959 this->table_.erase(ins.first);
960 else
961 {
962 this->table_.erase(insdef.first);
963 // Inserting insdef invalidated ins.
964 this->table_.erase(std::make_pair(name_key,
965 version_key));
966 }
967 return NULL;
968 }
969 }
970
971 ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
972
973 ins.first->second = ret;
974 if (def)
975 {
976 // This is the first time we have seen NAME/NULL. Point
977 // it at the new entry for NAME/VERSION.
978 gold_assert(insdef.second);
979 insdef.first->second = ret;
980 }
981 }
982
983 if (def)
984 ret->set_is_default();
985 }
986
987 // Record every time we see a new undefined symbol, to speed up
988 // archive groups.
989 if (!was_undefined && ret->is_undefined())
990 ++this->saw_undefined_;
991
992 // Keep track of common symbols, to speed up common symbol
993 // allocation.
994 if (!was_common && ret->is_common())
995 {
996 if (ret->type() == elfcpp::STT_TLS)
997 this->tls_commons_.push_back(ret);
998 else if (!is_ordinary
999 && st_shndx == parameters->target().small_common_shndx())
1000 this->small_commons_.push_back(ret);
1001 else if (!is_ordinary
1002 && st_shndx == parameters->target().large_common_shndx())
1003 this->large_commons_.push_back(ret);
1004 else
1005 this->commons_.push_back(ret);
1006 }
1007
1008 // If we're not doing a relocatable link, then any symbol with
1009 // hidden or internal visibility is local.
1010 if ((ret->visibility() == elfcpp::STV_HIDDEN
1011 || ret->visibility() == elfcpp::STV_INTERNAL)
1012 && (ret->binding() == elfcpp::STB_GLOBAL
1013 || ret->binding() == elfcpp::STB_GNU_UNIQUE
1014 || ret->binding() == elfcpp::STB_WEAK)
1015 && !parameters->options().relocatable())
1016 this->force_local(ret);
1017
1018 return ret;
1019 }
1020
1021 // Add all the symbols in a relocatable object to the hash table.
1022
1023 template<int size, bool big_endian>
1024 void
1025 Symbol_table::add_from_relobj(
1026 Sized_relobj<size, big_endian>* relobj,
1027 const unsigned char* syms,
1028 size_t count,
1029 size_t symndx_offset,
1030 const char* sym_names,
1031 size_t sym_name_size,
1032 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1033 size_t *defined)
1034 {
1035 *defined = 0;
1036
1037 gold_assert(size == parameters->target().get_size());
1038
1039 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1040
1041 const bool just_symbols = relobj->just_symbols();
1042
1043 const unsigned char* p = syms;
1044 for (size_t i = 0; i < count; ++i, p += sym_size)
1045 {
1046 (*sympointers)[i] = NULL;
1047
1048 elfcpp::Sym<size, big_endian> sym(p);
1049
1050 unsigned int st_name = sym.get_st_name();
1051 if (st_name >= sym_name_size)
1052 {
1053 relobj->error(_("bad global symbol name offset %u at %zu"),
1054 st_name, i);
1055 continue;
1056 }
1057
1058 const char* name = sym_names + st_name;
1059
1060 bool is_ordinary;
1061 unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1062 sym.get_st_shndx(),
1063 &is_ordinary);
1064 unsigned int orig_st_shndx = st_shndx;
1065 if (!is_ordinary)
1066 orig_st_shndx = elfcpp::SHN_UNDEF;
1067
1068 if (st_shndx != elfcpp::SHN_UNDEF)
1069 ++*defined;
1070
1071 // A symbol defined in a section which we are not including must
1072 // be treated as an undefined symbol.
1073 if (st_shndx != elfcpp::SHN_UNDEF
1074 && is_ordinary
1075 && !relobj->is_section_included(st_shndx))
1076 st_shndx = elfcpp::SHN_UNDEF;
1077
1078 // In an object file, an '@' in the name separates the symbol
1079 // name from the version name. If there are two '@' characters,
1080 // this is the default version.
1081 const char* ver = strchr(name, '@');
1082 Stringpool::Key ver_key = 0;
1083 int namelen = 0;
1084 // DEF: is the version default? LOCAL: is the symbol forced local?
1085 bool def = false;
1086 bool local = false;
1087
1088 if (ver != NULL)
1089 {
1090 // The symbol name is of the form foo@VERSION or foo@@VERSION
1091 namelen = ver - name;
1092 ++ver;
1093 if (*ver == '@')
1094 {
1095 def = true;
1096 ++ver;
1097 }
1098 ver = this->namepool_.add(ver, true, &ver_key);
1099 }
1100 // We don't want to assign a version to an undefined symbol,
1101 // even if it is listed in the version script. FIXME: What
1102 // about a common symbol?
1103 else
1104 {
1105 namelen = strlen(name);
1106 if (!this->version_script_.empty()
1107 && st_shndx != elfcpp::SHN_UNDEF)
1108 {
1109 // The symbol name did not have a version, but the
1110 // version script may assign a version anyway.
1111 std::string version;
1112 if (this->version_script_.get_symbol_version(name, &version))
1113 {
1114 // The version can be empty if the version script is
1115 // only used to force some symbols to be local.
1116 if (!version.empty())
1117 {
1118 ver = this->namepool_.add_with_length(version.c_str(),
1119 version.length(),
1120 true,
1121 &ver_key);
1122 def = true;
1123 }
1124 }
1125 else if (this->version_script_.symbol_is_local(name))
1126 local = true;
1127 }
1128 }
1129
1130 elfcpp::Sym<size, big_endian>* psym = &sym;
1131 unsigned char symbuf[sym_size];
1132 elfcpp::Sym<size, big_endian> sym2(symbuf);
1133 if (just_symbols)
1134 {
1135 memcpy(symbuf, p, sym_size);
1136 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1137 if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1138 {
1139 // Symbol values in object files are section relative.
1140 // This is normally what we want, but since here we are
1141 // converting the symbol to absolute we need to add the
1142 // section address. The section address in an object
1143 // file is normally zero, but people can use a linker
1144 // script to change it.
1145 sw.put_st_value(sym.get_st_value()
1146 + relobj->section_address(orig_st_shndx));
1147 }
1148 st_shndx = elfcpp::SHN_ABS;
1149 is_ordinary = false;
1150 psym = &sym2;
1151 }
1152
1153 // Fix up visibility if object has no-export set.
1154 if (relobj->no_export())
1155 {
1156 // We may have copied symbol already above.
1157 if (psym != &sym2)
1158 {
1159 memcpy(symbuf, p, sym_size);
1160 psym = &sym2;
1161 }
1162
1163 elfcpp::STV visibility = sym2.get_st_visibility();
1164 if (visibility == elfcpp::STV_DEFAULT
1165 || visibility == elfcpp::STV_PROTECTED)
1166 {
1167 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1168 unsigned char nonvis = sym2.get_st_nonvis();
1169 sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1170 }
1171 }
1172
1173 Stringpool::Key name_key;
1174 name = this->namepool_.add_with_length(name, namelen, true,
1175 &name_key);
1176
1177 Sized_symbol<size>* res;
1178 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1179 def, *psym, st_shndx, is_ordinary,
1180 orig_st_shndx);
1181
1182 // If building a shared library using garbage collection, do not
1183 // treat externally visible symbols as garbage.
1184 if (parameters->options().gc_sections()
1185 && parameters->options().shared())
1186 this->gc_mark_symbol_for_shlib(res);
1187
1188 if (local)
1189 this->force_local(res);
1190
1191 (*sympointers)[i] = res;
1192 }
1193 }
1194
1195 // Add a symbol from a plugin-claimed file.
1196
1197 template<int size, bool big_endian>
1198 Symbol*
1199 Symbol_table::add_from_pluginobj(
1200 Sized_pluginobj<size, big_endian>* obj,
1201 const char* name,
1202 const char* ver,
1203 elfcpp::Sym<size, big_endian>* sym)
1204 {
1205 unsigned int st_shndx = sym->get_st_shndx();
1206 bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1207
1208 Stringpool::Key ver_key = 0;
1209 bool def = false;
1210 bool local = false;
1211
1212 if (ver != NULL)
1213 {
1214 ver = this->namepool_.add(ver, true, &ver_key);
1215 }
1216 // We don't want to assign a version to an undefined symbol,
1217 // even if it is listed in the version script. FIXME: What
1218 // about a common symbol?
1219 else
1220 {
1221 if (!this->version_script_.empty()
1222 && st_shndx != elfcpp::SHN_UNDEF)
1223 {
1224 // The symbol name did not have a version, but the
1225 // version script may assign a version anyway.
1226 std::string version;
1227 if (this->version_script_.get_symbol_version(name, &version))
1228 {
1229 // The version can be empty if the version script is
1230 // only used to force some symbols to be local.
1231 if (!version.empty())
1232 {
1233 ver = this->namepool_.add_with_length(version.c_str(),
1234 version.length(),
1235 true,
1236 &ver_key);
1237 def = true;
1238 }
1239 }
1240 else if (this->version_script_.symbol_is_local(name))
1241 local = true;
1242 }
1243 }
1244
1245 Stringpool::Key name_key;
1246 name = this->namepool_.add(name, true, &name_key);
1247
1248 Sized_symbol<size>* res;
1249 res = this->add_from_object(obj, name, name_key, ver, ver_key,
1250 def, *sym, st_shndx, is_ordinary, st_shndx);
1251
1252 if (local)
1253 this->force_local(res);
1254
1255 return res;
1256 }
1257
1258 // Add all the symbols in a dynamic object to the hash table.
1259
1260 template<int size, bool big_endian>
1261 void
1262 Symbol_table::add_from_dynobj(
1263 Sized_dynobj<size, big_endian>* dynobj,
1264 const unsigned char* syms,
1265 size_t count,
1266 const char* sym_names,
1267 size_t sym_name_size,
1268 const unsigned char* versym,
1269 size_t versym_size,
1270 const std::vector<const char*>* version_map,
1271 typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1272 size_t* defined)
1273 {
1274 *defined = 0;
1275
1276 gold_assert(size == parameters->target().get_size());
1277
1278 if (dynobj->just_symbols())
1279 {
1280 gold_error(_("--just-symbols does not make sense with a shared object"));
1281 return;
1282 }
1283
1284 if (versym != NULL && versym_size / 2 < count)
1285 {
1286 dynobj->error(_("too few symbol versions"));
1287 return;
1288 }
1289
1290 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1291
1292 // We keep a list of all STT_OBJECT symbols, so that we can resolve
1293 // weak aliases. This is necessary because if the dynamic object
1294 // provides the same variable under two names, one of which is a
1295 // weak definition, and the regular object refers to the weak
1296 // definition, we have to put both the weak definition and the
1297 // strong definition into the dynamic symbol table. Given a weak
1298 // definition, the only way that we can find the corresponding
1299 // strong definition, if any, is to search the symbol table.
1300 std::vector<Sized_symbol<size>*> object_symbols;
1301
1302 const unsigned char* p = syms;
1303 const unsigned char* vs = versym;
1304 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1305 {
1306 elfcpp::Sym<size, big_endian> sym(p);
1307
1308 if (sympointers != NULL)
1309 (*sympointers)[i] = NULL;
1310
1311 // Ignore symbols with local binding or that have
1312 // internal or hidden visibility.
1313 if (sym.get_st_bind() == elfcpp::STB_LOCAL
1314 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1315 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1316 continue;
1317
1318 // A protected symbol in a shared library must be treated as a
1319 // normal symbol when viewed from outside the shared library.
1320 // Implement this by overriding the visibility here.
1321 elfcpp::Sym<size, big_endian>* psym = &sym;
1322 unsigned char symbuf[sym_size];
1323 elfcpp::Sym<size, big_endian> sym2(symbuf);
1324 if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1325 {
1326 memcpy(symbuf, p, sym_size);
1327 elfcpp::Sym_write<size, big_endian> sw(symbuf);
1328 sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1329 psym = &sym2;
1330 }
1331
1332 unsigned int st_name = psym->get_st_name();
1333 if (st_name >= sym_name_size)
1334 {
1335 dynobj->error(_("bad symbol name offset %u at %zu"),
1336 st_name, i);
1337 continue;
1338 }
1339
1340 const char* name = sym_names + st_name;
1341
1342 bool is_ordinary;
1343 unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1344 &is_ordinary);
1345
1346 if (st_shndx != elfcpp::SHN_UNDEF)
1347 ++*defined;
1348
1349 Sized_symbol<size>* res;
1350
1351 if (versym == NULL)
1352 {
1353 Stringpool::Key name_key;
1354 name = this->namepool_.add(name, true, &name_key);
1355 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1356 false, *psym, st_shndx, is_ordinary,
1357 st_shndx);
1358 }
1359 else
1360 {
1361 // Read the version information.
1362
1363 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1364
1365 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1366 v &= elfcpp::VERSYM_VERSION;
1367
1368 // The Sun documentation says that V can be VER_NDX_LOCAL,
1369 // or VER_NDX_GLOBAL, or a version index. The meaning of
1370 // VER_NDX_LOCAL is defined as "Symbol has local scope."
1371 // The old GNU linker will happily generate VER_NDX_LOCAL
1372 // for an undefined symbol. I don't know what the Sun
1373 // linker will generate.
1374
1375 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1376 && st_shndx != elfcpp::SHN_UNDEF)
1377 {
1378 // This symbol should not be visible outside the object.
1379 continue;
1380 }
1381
1382 // At this point we are definitely going to add this symbol.
1383 Stringpool::Key name_key;
1384 name = this->namepool_.add(name, true, &name_key);
1385
1386 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1387 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1388 {
1389 // This symbol does not have a version.
1390 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1391 false, *psym, st_shndx, is_ordinary,
1392 st_shndx);
1393 }
1394 else
1395 {
1396 if (v >= version_map->size())
1397 {
1398 dynobj->error(_("versym for symbol %zu out of range: %u"),
1399 i, v);
1400 continue;
1401 }
1402
1403 const char* version = (*version_map)[v];
1404 if (version == NULL)
1405 {
1406 dynobj->error(_("versym for symbol %zu has no name: %u"),
1407 i, v);
1408 continue;
1409 }
1410
1411 Stringpool::Key version_key;
1412 version = this->namepool_.add(version, true, &version_key);
1413
1414 // If this is an absolute symbol, and the version name
1415 // and symbol name are the same, then this is the
1416 // version definition symbol. These symbols exist to
1417 // support using -u to pull in particular versions. We
1418 // do not want to record a version for them.
1419 if (st_shndx == elfcpp::SHN_ABS
1420 && !is_ordinary
1421 && name_key == version_key)
1422 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1423 false, *psym, st_shndx, is_ordinary,
1424 st_shndx);
1425 else
1426 {
1427 const bool def = (!hidden
1428 && st_shndx != elfcpp::SHN_UNDEF);
1429 res = this->add_from_object(dynobj, name, name_key, version,
1430 version_key, def, *psym, st_shndx,
1431 is_ordinary, st_shndx);
1432 }
1433 }
1434 }
1435
1436 // Note that it is possible that RES was overridden by an
1437 // earlier object, in which case it can't be aliased here.
1438 if (st_shndx != elfcpp::SHN_UNDEF
1439 && is_ordinary
1440 && psym->get_st_type() == elfcpp::STT_OBJECT
1441 && res->source() == Symbol::FROM_OBJECT
1442 && res->object() == dynobj)
1443 object_symbols.push_back(res);
1444
1445 if (sympointers != NULL)
1446 (*sympointers)[i] = res;
1447 }
1448
1449 this->record_weak_aliases(&object_symbols);
1450 }
1451
1452 // This is used to sort weak aliases. We sort them first by section
1453 // index, then by offset, then by weak ahead of strong.
1454
1455 template<int size>
1456 class Weak_alias_sorter
1457 {
1458 public:
1459 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1460 };
1461
1462 template<int size>
1463 bool
1464 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1465 const Sized_symbol<size>* s2) const
1466 {
1467 bool is_ordinary;
1468 unsigned int s1_shndx = s1->shndx(&is_ordinary);
1469 gold_assert(is_ordinary);
1470 unsigned int s2_shndx = s2->shndx(&is_ordinary);
1471 gold_assert(is_ordinary);
1472 if (s1_shndx != s2_shndx)
1473 return s1_shndx < s2_shndx;
1474
1475 if (s1->value() != s2->value())
1476 return s1->value() < s2->value();
1477 if (s1->binding() != s2->binding())
1478 {
1479 if (s1->binding() == elfcpp::STB_WEAK)
1480 return true;
1481 if (s2->binding() == elfcpp::STB_WEAK)
1482 return false;
1483 }
1484 return std::string(s1->name()) < std::string(s2->name());
1485 }
1486
1487 // SYMBOLS is a list of object symbols from a dynamic object. Look
1488 // for any weak aliases, and record them so that if we add the weak
1489 // alias to the dynamic symbol table, we also add the corresponding
1490 // strong symbol.
1491
1492 template<int size>
1493 void
1494 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1495 {
1496 // Sort the vector by section index, then by offset, then by weak
1497 // ahead of strong.
1498 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1499
1500 // Walk through the vector. For each weak definition, record
1501 // aliases.
1502 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1503 symbols->begin();
1504 p != symbols->end();
1505 ++p)
1506 {
1507 if ((*p)->binding() != elfcpp::STB_WEAK)
1508 continue;
1509
1510 // Build a circular list of weak aliases. Each symbol points to
1511 // the next one in the circular list.
1512
1513 Sized_symbol<size>* from_sym = *p;
1514 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1515 for (q = p + 1; q != symbols->end(); ++q)
1516 {
1517 bool dummy;
1518 if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1519 || (*q)->value() != from_sym->value())
1520 break;
1521
1522 this->weak_aliases_[from_sym] = *q;
1523 from_sym->set_has_alias();
1524 from_sym = *q;
1525 }
1526
1527 if (from_sym != *p)
1528 {
1529 this->weak_aliases_[from_sym] = *p;
1530 from_sym->set_has_alias();
1531 }
1532
1533 p = q - 1;
1534 }
1535 }
1536
1537 // Create and return a specially defined symbol. If ONLY_IF_REF is
1538 // true, then only create the symbol if there is a reference to it.
1539 // If this does not return NULL, it sets *POLDSYM to the existing
1540 // symbol if there is one. This sets *RESOLVE_OLDSYM if we should
1541 // resolve the newly created symbol to the old one. This
1542 // canonicalizes *PNAME and *PVERSION.
1543
1544 template<int size, bool big_endian>
1545 Sized_symbol<size>*
1546 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1547 bool only_if_ref,
1548 Sized_symbol<size>** poldsym,
1549 bool *resolve_oldsym)
1550 {
1551 *resolve_oldsym = false;
1552
1553 // If the caller didn't give us a version, see if we get one from
1554 // the version script.
1555 std::string v;
1556 bool is_default_version = false;
1557 if (*pversion == NULL)
1558 {
1559 if (this->version_script_.get_symbol_version(*pname, &v))
1560 {
1561 if (!v.empty())
1562 *pversion = v.c_str();
1563
1564 // If we get the version from a version script, then we are
1565 // also the default version.
1566 is_default_version = true;
1567 }
1568 }
1569
1570 Symbol* oldsym;
1571 Sized_symbol<size>* sym;
1572
1573 bool add_to_table = false;
1574 typename Symbol_table_type::iterator add_loc = this->table_.end();
1575 bool add_def_to_table = false;
1576 typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1577
1578 if (only_if_ref)
1579 {
1580 oldsym = this->lookup(*pname, *pversion);
1581 if (oldsym == NULL && is_default_version)
1582 oldsym = this->lookup(*pname, NULL);
1583 if (oldsym == NULL || !oldsym->is_undefined())
1584 return NULL;
1585
1586 *pname = oldsym->name();
1587 if (!is_default_version)
1588 *pversion = oldsym->version();
1589 }
1590 else
1591 {
1592 // Canonicalize NAME and VERSION.
1593 Stringpool::Key name_key;
1594 *pname = this->namepool_.add(*pname, true, &name_key);
1595
1596 Stringpool::Key version_key = 0;
1597 if (*pversion != NULL)
1598 *pversion = this->namepool_.add(*pversion, true, &version_key);
1599
1600 Symbol* const snull = NULL;
1601 std::pair<typename Symbol_table_type::iterator, bool> ins =
1602 this->table_.insert(std::make_pair(std::make_pair(name_key,
1603 version_key),
1604 snull));
1605
1606 std::pair<typename Symbol_table_type::iterator, bool> insdef =
1607 std::make_pair(this->table_.end(), false);
1608 if (is_default_version)
1609 {
1610 const Stringpool::Key vnull = 0;
1611 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
1612 vnull),
1613 snull));
1614 }
1615
1616 if (!ins.second)
1617 {
1618 // We already have a symbol table entry for NAME/VERSION.
1619 oldsym = ins.first->second;
1620 gold_assert(oldsym != NULL);
1621
1622 if (is_default_version)
1623 {
1624 Sized_symbol<size>* soldsym =
1625 this->get_sized_symbol<size>(oldsym);
1626 this->define_default_version<size, big_endian>(soldsym,
1627 insdef.second,
1628 insdef.first);
1629 }
1630 }
1631 else
1632 {
1633 // We haven't seen this symbol before.
1634 gold_assert(ins.first->second == NULL);
1635
1636 add_to_table = true;
1637 add_loc = ins.first;
1638
1639 if (is_default_version && !insdef.second)
1640 {
1641 // We are adding NAME/VERSION, and it is the default
1642 // version. We already have an entry for NAME/NULL.
1643 oldsym = insdef.first->second;
1644 *resolve_oldsym = true;
1645 }
1646 else
1647 {
1648 oldsym = NULL;
1649
1650 if (is_default_version)
1651 {
1652 add_def_to_table = true;
1653 add_def_loc = insdef.first;
1654 }
1655 }
1656 }
1657 }
1658
1659 const Target& target = parameters->target();
1660 if (!target.has_make_symbol())
1661 sym = new Sized_symbol<size>();
1662 else
1663 {
1664 Sized_target<size, big_endian>* sized_target =
1665 parameters->sized_target<size, big_endian>();
1666 sym = sized_target->make_symbol();
1667 if (sym == NULL)
1668 return NULL;
1669 }
1670
1671 if (add_to_table)
1672 add_loc->second = sym;
1673 else
1674 gold_assert(oldsym != NULL);
1675
1676 if (add_def_to_table)
1677 add_def_loc->second = sym;
1678
1679 *poldsym = this->get_sized_symbol<size>(oldsym);
1680
1681 return sym;
1682 }
1683
1684 // Define a symbol based on an Output_data.
1685
1686 Symbol*
1687 Symbol_table::define_in_output_data(const char* name,
1688 const char* version,
1689 Output_data* od,
1690 uint64_t value,
1691 uint64_t symsize,
1692 elfcpp::STT type,
1693 elfcpp::STB binding,
1694 elfcpp::STV visibility,
1695 unsigned char nonvis,
1696 bool offset_is_from_end,
1697 bool only_if_ref)
1698 {
1699 if (parameters->target().get_size() == 32)
1700 {
1701 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1702 return this->do_define_in_output_data<32>(name, version, od,
1703 value, symsize, type, binding,
1704 visibility, nonvis,
1705 offset_is_from_end,
1706 only_if_ref);
1707 #else
1708 gold_unreachable();
1709 #endif
1710 }
1711 else if (parameters->target().get_size() == 64)
1712 {
1713 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1714 return this->do_define_in_output_data<64>(name, version, od,
1715 value, symsize, type, binding,
1716 visibility, nonvis,
1717 offset_is_from_end,
1718 only_if_ref);
1719 #else
1720 gold_unreachable();
1721 #endif
1722 }
1723 else
1724 gold_unreachable();
1725 }
1726
1727 // Define a symbol in an Output_data, sized version.
1728
1729 template<int size>
1730 Sized_symbol<size>*
1731 Symbol_table::do_define_in_output_data(
1732 const char* name,
1733 const char* version,
1734 Output_data* od,
1735 typename elfcpp::Elf_types<size>::Elf_Addr value,
1736 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1737 elfcpp::STT type,
1738 elfcpp::STB binding,
1739 elfcpp::STV visibility,
1740 unsigned char nonvis,
1741 bool offset_is_from_end,
1742 bool only_if_ref)
1743 {
1744 Sized_symbol<size>* sym;
1745 Sized_symbol<size>* oldsym;
1746 bool resolve_oldsym;
1747
1748 if (parameters->target().is_big_endian())
1749 {
1750 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1751 sym = this->define_special_symbol<size, true>(&name, &version,
1752 only_if_ref, &oldsym,
1753 &resolve_oldsym);
1754 #else
1755 gold_unreachable();
1756 #endif
1757 }
1758 else
1759 {
1760 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1761 sym = this->define_special_symbol<size, false>(&name, &version,
1762 only_if_ref, &oldsym,
1763 &resolve_oldsym);
1764 #else
1765 gold_unreachable();
1766 #endif
1767 }
1768
1769 if (sym == NULL)
1770 return NULL;
1771
1772 sym->init_output_data(name, version, od, value, symsize, type, binding,
1773 visibility, nonvis, offset_is_from_end);
1774
1775 if (oldsym == NULL)
1776 {
1777 if (binding == elfcpp::STB_LOCAL
1778 || this->version_script_.symbol_is_local(name))
1779 this->force_local(sym);
1780 else if (version != NULL)
1781 sym->set_is_default();
1782 return sym;
1783 }
1784
1785 if (Symbol_table::should_override_with_special(oldsym))
1786 this->override_with_special(oldsym, sym);
1787
1788 if (resolve_oldsym)
1789 return sym;
1790 else
1791 {
1792 delete sym;
1793 return oldsym;
1794 }
1795 }
1796
1797 // Define a symbol based on an Output_segment.
1798
1799 Symbol*
1800 Symbol_table::define_in_output_segment(const char* name,
1801 const char* version, Output_segment* os,
1802 uint64_t value,
1803 uint64_t symsize,
1804 elfcpp::STT type,
1805 elfcpp::STB binding,
1806 elfcpp::STV visibility,
1807 unsigned char nonvis,
1808 Symbol::Segment_offset_base offset_base,
1809 bool only_if_ref)
1810 {
1811 if (parameters->target().get_size() == 32)
1812 {
1813 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1814 return this->do_define_in_output_segment<32>(name, version, os,
1815 value, symsize, type,
1816 binding, visibility, nonvis,
1817 offset_base, only_if_ref);
1818 #else
1819 gold_unreachable();
1820 #endif
1821 }
1822 else if (parameters->target().get_size() == 64)
1823 {
1824 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1825 return this->do_define_in_output_segment<64>(name, version, os,
1826 value, symsize, type,
1827 binding, visibility, nonvis,
1828 offset_base, only_if_ref);
1829 #else
1830 gold_unreachable();
1831 #endif
1832 }
1833 else
1834 gold_unreachable();
1835 }
1836
1837 // Define a symbol in an Output_segment, sized version.
1838
1839 template<int size>
1840 Sized_symbol<size>*
1841 Symbol_table::do_define_in_output_segment(
1842 const char* name,
1843 const char* version,
1844 Output_segment* os,
1845 typename elfcpp::Elf_types<size>::Elf_Addr value,
1846 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1847 elfcpp::STT type,
1848 elfcpp::STB binding,
1849 elfcpp::STV visibility,
1850 unsigned char nonvis,
1851 Symbol::Segment_offset_base offset_base,
1852 bool only_if_ref)
1853 {
1854 Sized_symbol<size>* sym;
1855 Sized_symbol<size>* oldsym;
1856 bool resolve_oldsym;
1857
1858 if (parameters->target().is_big_endian())
1859 {
1860 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1861 sym = this->define_special_symbol<size, true>(&name, &version,
1862 only_if_ref, &oldsym,
1863 &resolve_oldsym);
1864 #else
1865 gold_unreachable();
1866 #endif
1867 }
1868 else
1869 {
1870 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1871 sym = this->define_special_symbol<size, false>(&name, &version,
1872 only_if_ref, &oldsym,
1873 &resolve_oldsym);
1874 #else
1875 gold_unreachable();
1876 #endif
1877 }
1878
1879 if (sym == NULL)
1880 return NULL;
1881
1882 sym->init_output_segment(name, version, os, value, symsize, type, binding,
1883 visibility, nonvis, offset_base);
1884
1885 if (oldsym == NULL)
1886 {
1887 if (binding == elfcpp::STB_LOCAL
1888 || this->version_script_.symbol_is_local(name))
1889 this->force_local(sym);
1890 else if (version != NULL)
1891 sym->set_is_default();
1892 return sym;
1893 }
1894
1895 if (Symbol_table::should_override_with_special(oldsym))
1896 this->override_with_special(oldsym, sym);
1897
1898 if (resolve_oldsym)
1899 return sym;
1900 else
1901 {
1902 delete sym;
1903 return oldsym;
1904 }
1905 }
1906
1907 // Define a special symbol with a constant value. It is a multiple
1908 // definition error if this symbol is already defined.
1909
1910 Symbol*
1911 Symbol_table::define_as_constant(const char* name,
1912 const char* version,
1913 uint64_t value,
1914 uint64_t symsize,
1915 elfcpp::STT type,
1916 elfcpp::STB binding,
1917 elfcpp::STV visibility,
1918 unsigned char nonvis,
1919 bool only_if_ref,
1920 bool force_override)
1921 {
1922 if (parameters->target().get_size() == 32)
1923 {
1924 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1925 return this->do_define_as_constant<32>(name, version, value,
1926 symsize, type, binding,
1927 visibility, nonvis, only_if_ref,
1928 force_override);
1929 #else
1930 gold_unreachable();
1931 #endif
1932 }
1933 else if (parameters->target().get_size() == 64)
1934 {
1935 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1936 return this->do_define_as_constant<64>(name, version, value,
1937 symsize, type, binding,
1938 visibility, nonvis, only_if_ref,
1939 force_override);
1940 #else
1941 gold_unreachable();
1942 #endif
1943 }
1944 else
1945 gold_unreachable();
1946 }
1947
1948 // Define a symbol as a constant, sized version.
1949
1950 template<int size>
1951 Sized_symbol<size>*
1952 Symbol_table::do_define_as_constant(
1953 const char* name,
1954 const char* version,
1955 typename elfcpp::Elf_types<size>::Elf_Addr value,
1956 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1957 elfcpp::STT type,
1958 elfcpp::STB binding,
1959 elfcpp::STV visibility,
1960 unsigned char nonvis,
1961 bool only_if_ref,
1962 bool force_override)
1963 {
1964 Sized_symbol<size>* sym;
1965 Sized_symbol<size>* oldsym;
1966 bool resolve_oldsym;
1967
1968 if (parameters->target().is_big_endian())
1969 {
1970 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1971 sym = this->define_special_symbol<size, true>(&name, &version,
1972 only_if_ref, &oldsym,
1973 &resolve_oldsym);
1974 #else
1975 gold_unreachable();
1976 #endif
1977 }
1978 else
1979 {
1980 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1981 sym = this->define_special_symbol<size, false>(&name, &version,
1982 only_if_ref, &oldsym,
1983 &resolve_oldsym);
1984 #else
1985 gold_unreachable();
1986 #endif
1987 }
1988
1989 if (sym == NULL)
1990 return NULL;
1991
1992 sym->init_constant(name, version, value, symsize, type, binding, visibility,
1993 nonvis);
1994
1995 if (oldsym == NULL)
1996 {
1997 // Version symbols are absolute symbols with name == version.
1998 // We don't want to force them to be local.
1999 if ((version == NULL
2000 || name != version
2001 || value != 0)
2002 && (binding == elfcpp::STB_LOCAL
2003 || this->version_script_.symbol_is_local(name)))
2004 this->force_local(sym);
2005 else if (version != NULL
2006 && (name != version || value != 0))
2007 sym->set_is_default();
2008 return sym;
2009 }
2010
2011 if (force_override || Symbol_table::should_override_with_special(oldsym))
2012 this->override_with_special(oldsym, sym);
2013
2014 if (resolve_oldsym)
2015 return sym;
2016 else
2017 {
2018 delete sym;
2019 return oldsym;
2020 }
2021 }
2022
2023 // Define a set of symbols in output sections.
2024
2025 void
2026 Symbol_table::define_symbols(const Layout* layout, int count,
2027 const Define_symbol_in_section* p,
2028 bool only_if_ref)
2029 {
2030 for (int i = 0; i < count; ++i, ++p)
2031 {
2032 Output_section* os = layout->find_output_section(p->output_section);
2033 if (os != NULL)
2034 this->define_in_output_data(p->name, NULL, os, p->value,
2035 p->size, p->type, p->binding,
2036 p->visibility, p->nonvis,
2037 p->offset_is_from_end,
2038 only_if_ref || p->only_if_ref);
2039 else
2040 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2041 p->binding, p->visibility, p->nonvis,
2042 only_if_ref || p->only_if_ref,
2043 false);
2044 }
2045 }
2046
2047 // Define a set of symbols in output segments.
2048
2049 void
2050 Symbol_table::define_symbols(const Layout* layout, int count,
2051 const Define_symbol_in_segment* p,
2052 bool only_if_ref)
2053 {
2054 for (int i = 0; i < count; ++i, ++p)
2055 {
2056 Output_segment* os = layout->find_output_segment(p->segment_type,
2057 p->segment_flags_set,
2058 p->segment_flags_clear);
2059 if (os != NULL)
2060 this->define_in_output_segment(p->name, NULL, os, p->value,
2061 p->size, p->type, p->binding,
2062 p->visibility, p->nonvis,
2063 p->offset_base,
2064 only_if_ref || p->only_if_ref);
2065 else
2066 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
2067 p->binding, p->visibility, p->nonvis,
2068 only_if_ref || p->only_if_ref,
2069 false);
2070 }
2071 }
2072
2073 // Define CSYM using a COPY reloc. POSD is the Output_data where the
2074 // symbol should be defined--typically a .dyn.bss section. VALUE is
2075 // the offset within POSD.
2076
2077 template<int size>
2078 void
2079 Symbol_table::define_with_copy_reloc(
2080 Sized_symbol<size>* csym,
2081 Output_data* posd,
2082 typename elfcpp::Elf_types<size>::Elf_Addr value)
2083 {
2084 gold_assert(csym->is_from_dynobj());
2085 gold_assert(!csym->is_copied_from_dynobj());
2086 Object* object = csym->object();
2087 gold_assert(object->is_dynamic());
2088 Dynobj* dynobj = static_cast<Dynobj*>(object);
2089
2090 // Our copied variable has to override any variable in a shared
2091 // library.
2092 elfcpp::STB binding = csym->binding();
2093 if (binding == elfcpp::STB_WEAK)
2094 binding = elfcpp::STB_GLOBAL;
2095
2096 this->define_in_output_data(csym->name(), csym->version(),
2097 posd, value, csym->symsize(),
2098 csym->type(), binding,
2099 csym->visibility(), csym->nonvis(),
2100 false, false);
2101
2102 csym->set_is_copied_from_dynobj();
2103 csym->set_needs_dynsym_entry();
2104
2105 this->copied_symbol_dynobjs_[csym] = dynobj;
2106
2107 // We have now defined all aliases, but we have not entered them all
2108 // in the copied_symbol_dynobjs_ map.
2109 if (csym->has_alias())
2110 {
2111 Symbol* sym = csym;
2112 while (true)
2113 {
2114 sym = this->weak_aliases_[sym];
2115 if (sym == csym)
2116 break;
2117 gold_assert(sym->output_data() == posd);
2118
2119 sym->set_is_copied_from_dynobj();
2120 this->copied_symbol_dynobjs_[sym] = dynobj;
2121 }
2122 }
2123 }
2124
2125 // SYM is defined using a COPY reloc. Return the dynamic object where
2126 // the original definition was found.
2127
2128 Dynobj*
2129 Symbol_table::get_copy_source(const Symbol* sym) const
2130 {
2131 gold_assert(sym->is_copied_from_dynobj());
2132 Copied_symbol_dynobjs::const_iterator p =
2133 this->copied_symbol_dynobjs_.find(sym);
2134 gold_assert(p != this->copied_symbol_dynobjs_.end());
2135 return p->second;
2136 }
2137
2138 // Add any undefined symbols named on the command line.
2139
2140 void
2141 Symbol_table::add_undefined_symbols_from_command_line()
2142 {
2143 if (parameters->options().any_undefined())
2144 {
2145 if (parameters->target().get_size() == 32)
2146 {
2147 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2148 this->do_add_undefined_symbols_from_command_line<32>();
2149 #else
2150 gold_unreachable();
2151 #endif
2152 }
2153 else if (parameters->target().get_size() == 64)
2154 {
2155 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2156 this->do_add_undefined_symbols_from_command_line<64>();
2157 #else
2158 gold_unreachable();
2159 #endif
2160 }
2161 else
2162 gold_unreachable();
2163 }
2164 }
2165
2166 template<int size>
2167 void
2168 Symbol_table::do_add_undefined_symbols_from_command_line()
2169 {
2170 for (options::String_set::const_iterator p =
2171 parameters->options().undefined_begin();
2172 p != parameters->options().undefined_end();
2173 ++p)
2174 {
2175 const char* name = p->c_str();
2176
2177 if (this->lookup(name) != NULL)
2178 continue;
2179
2180 const char* version = NULL;
2181
2182 Sized_symbol<size>* sym;
2183 Sized_symbol<size>* oldsym;
2184 bool resolve_oldsym;
2185 if (parameters->target().is_big_endian())
2186 {
2187 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2188 sym = this->define_special_symbol<size, true>(&name, &version,
2189 false, &oldsym,
2190 &resolve_oldsym);
2191 #else
2192 gold_unreachable();
2193 #endif
2194 }
2195 else
2196 {
2197 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2198 sym = this->define_special_symbol<size, false>(&name, &version,
2199 false, &oldsym,
2200 &resolve_oldsym);
2201 #else
2202 gold_unreachable();
2203 #endif
2204 }
2205
2206 gold_assert(oldsym == NULL);
2207
2208 sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2209 elfcpp::STV_DEFAULT, 0);
2210 ++this->saw_undefined_;
2211 }
2212 }
2213
2214 // Set the dynamic symbol indexes. INDEX is the index of the first
2215 // global dynamic symbol. Pointers to the symbols are stored into the
2216 // vector SYMS. The names are added to DYNPOOL. This returns an
2217 // updated dynamic symbol index.
2218
2219 unsigned int
2220 Symbol_table::set_dynsym_indexes(unsigned int index,
2221 std::vector<Symbol*>* syms,
2222 Stringpool* dynpool,
2223 Versions* versions)
2224 {
2225 for (Symbol_table_type::iterator p = this->table_.begin();
2226 p != this->table_.end();
2227 ++p)
2228 {
2229 Symbol* sym = p->second;
2230
2231 // Note that SYM may already have a dynamic symbol index, since
2232 // some symbols appear more than once in the symbol table, with
2233 // and without a version.
2234
2235 if (!sym->should_add_dynsym_entry())
2236 sym->set_dynsym_index(-1U);
2237 else if (!sym->has_dynsym_index())
2238 {
2239 sym->set_dynsym_index(index);
2240 ++index;
2241 syms->push_back(sym);
2242 dynpool->add(sym->name(), false, NULL);
2243
2244 // Record any version information.
2245 if (sym->version() != NULL)
2246 versions->record_version(this, dynpool, sym);
2247
2248 // If the symbol is defined in a dynamic object and is
2249 // referenced in a regular object, then mark the dynamic
2250 // object as needed. This is used to implement --as-needed.
2251 if (sym->is_from_dynobj() && sym->in_reg())
2252 sym->object()->set_is_needed();
2253 }
2254 }
2255
2256 // Finish up the versions. In some cases this may add new dynamic
2257 // symbols.
2258 index = versions->finalize(this, index, syms);
2259
2260 return index;
2261 }
2262
2263 // Set the final values for all the symbols. The index of the first
2264 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
2265 // file offset OFF. Add their names to POOL. Return the new file
2266 // offset. Update *PLOCAL_SYMCOUNT if necessary.
2267
2268 off_t
2269 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2270 size_t dyncount, Stringpool* pool,
2271 unsigned int *plocal_symcount)
2272 {
2273 off_t ret;
2274
2275 gold_assert(*plocal_symcount != 0);
2276 this->first_global_index_ = *plocal_symcount;
2277
2278 this->dynamic_offset_ = dynoff;
2279 this->first_dynamic_global_index_ = dyn_global_index;
2280 this->dynamic_count_ = dyncount;
2281
2282 if (parameters->target().get_size() == 32)
2283 {
2284 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2285 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2286 #else
2287 gold_unreachable();
2288 #endif
2289 }
2290 else if (parameters->target().get_size() == 64)
2291 {
2292 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2293 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2294 #else
2295 gold_unreachable();
2296 #endif
2297 }
2298 else
2299 gold_unreachable();
2300
2301 // Now that we have the final symbol table, we can reliably note
2302 // which symbols should get warnings.
2303 this->warnings_.note_warnings(this);
2304
2305 return ret;
2306 }
2307
2308 // SYM is going into the symbol table at *PINDEX. Add the name to
2309 // POOL, update *PINDEX and *POFF.
2310
2311 template<int size>
2312 void
2313 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2314 unsigned int* pindex, off_t* poff)
2315 {
2316 sym->set_symtab_index(*pindex);
2317 pool->add(sym->name(), false, NULL);
2318 ++*pindex;
2319 *poff += elfcpp::Elf_sizes<size>::sym_size;
2320 }
2321
2322 // Set the final value for all the symbols. This is called after
2323 // Layout::finalize, so all the output sections have their final
2324 // address.
2325
2326 template<int size>
2327 off_t
2328 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2329 unsigned int* plocal_symcount)
2330 {
2331 off = align_address(off, size >> 3);
2332 this->offset_ = off;
2333
2334 unsigned int index = *plocal_symcount;
2335 const unsigned int orig_index = index;
2336
2337 // First do all the symbols which have been forced to be local, as
2338 // they must appear before all global symbols.
2339 for (Forced_locals::iterator p = this->forced_locals_.begin();
2340 p != this->forced_locals_.end();
2341 ++p)
2342 {
2343 Symbol* sym = *p;
2344 gold_assert(sym->is_forced_local());
2345 if (this->sized_finalize_symbol<size>(sym))
2346 {
2347 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2348 ++*plocal_symcount;
2349 }
2350 }
2351
2352 // Now do all the remaining symbols.
2353 for (Symbol_table_type::iterator p = this->table_.begin();
2354 p != this->table_.end();
2355 ++p)
2356 {
2357 Symbol* sym = p->second;
2358 if (this->sized_finalize_symbol<size>(sym))
2359 this->add_to_final_symtab<size>(sym, pool, &index, &off);
2360 }
2361
2362 this->output_count_ = index - orig_index;
2363
2364 return off;
2365 }
2366
2367 // Compute the final value of SYM and store status in location PSTATUS.
2368 // During relaxation, this may be called multiple times for a symbol to
2369 // compute its would-be final value in each relaxation pass.
2370
2371 template<int size>
2372 typename Sized_symbol<size>::Value_type
2373 Symbol_table::compute_final_value(
2374 const Sized_symbol<size>* sym,
2375 Compute_final_value_status* pstatus) const
2376 {
2377 typedef typename Sized_symbol<size>::Value_type Value_type;
2378 Value_type value;
2379
2380 switch (sym->source())
2381 {
2382 case Symbol::FROM_OBJECT:
2383 {
2384 bool is_ordinary;
2385 unsigned int shndx = sym->shndx(&is_ordinary);
2386
2387 if (!is_ordinary
2388 && shndx != elfcpp::SHN_ABS
2389 && !Symbol::is_common_shndx(shndx))
2390 {
2391 *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2392 return 0;
2393 }
2394
2395 Object* symobj = sym->object();
2396 if (symobj->is_dynamic())
2397 {
2398 value = 0;
2399 shndx = elfcpp::SHN_UNDEF;
2400 }
2401 else if (symobj->pluginobj() != NULL)
2402 {
2403 value = 0;
2404 shndx = elfcpp::SHN_UNDEF;
2405 }
2406 else if (shndx == elfcpp::SHN_UNDEF)
2407 value = 0;
2408 else if (!is_ordinary
2409 && (shndx == elfcpp::SHN_ABS
2410 || Symbol::is_common_shndx(shndx)))
2411 value = sym->value();
2412 else
2413 {
2414 Relobj* relobj = static_cast<Relobj*>(symobj);
2415 Output_section* os = relobj->output_section(shndx);
2416 uint64_t secoff64 = relobj->output_section_offset(shndx);
2417
2418 if (this->is_section_folded(relobj, shndx))
2419 {
2420 gold_assert(os == NULL);
2421 // Get the os of the section it is folded onto.
2422 Section_id folded = this->icf_->get_folded_section(relobj,
2423 shndx);
2424 gold_assert(folded.first != NULL);
2425 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2426 os = folded_obj->output_section(folded.second);
2427 gold_assert(os != NULL);
2428 secoff64 = folded_obj->output_section_offset(folded.second);
2429 }
2430
2431 if (os == NULL)
2432 {
2433 bool static_or_reloc = (parameters->doing_static_link() ||
2434 parameters->options().relocatable());
2435 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2436
2437 *pstatus = CFVS_NO_OUTPUT_SECTION;
2438 return 0;
2439 }
2440
2441 if (secoff64 == -1ULL)
2442 {
2443 // The section needs special handling (e.g., a merge section).
2444
2445 value = os->output_address(relobj, shndx, sym->value());
2446 }
2447 else
2448 {
2449 Value_type secoff =
2450 convert_types<Value_type, uint64_t>(secoff64);
2451 if (sym->type() == elfcpp::STT_TLS)
2452 value = sym->value() + os->tls_offset() + secoff;
2453 else
2454 value = sym->value() + os->address() + secoff;
2455 }
2456 }
2457 }
2458 break;
2459
2460 case Symbol::IN_OUTPUT_DATA:
2461 {
2462 Output_data* od = sym->output_data();
2463 value = sym->value();
2464 if (sym->type() != elfcpp::STT_TLS)
2465 value += od->address();
2466 else
2467 {
2468 Output_section* os = od->output_section();
2469 gold_assert(os != NULL);
2470 value += os->tls_offset() + (od->address() - os->address());
2471 }
2472 if (sym->offset_is_from_end())
2473 value += od->data_size();
2474 }
2475 break;
2476
2477 case Symbol::IN_OUTPUT_SEGMENT:
2478 {
2479 Output_segment* os = sym->output_segment();
2480 value = sym->value();
2481 if (sym->type() != elfcpp::STT_TLS)
2482 value += os->vaddr();
2483 switch (sym->offset_base())
2484 {
2485 case Symbol::SEGMENT_START:
2486 break;
2487 case Symbol::SEGMENT_END:
2488 value += os->memsz();
2489 break;
2490 case Symbol::SEGMENT_BSS:
2491 value += os->filesz();
2492 break;
2493 default:
2494 gold_unreachable();
2495 }
2496 }
2497 break;
2498
2499 case Symbol::IS_CONSTANT:
2500 value = sym->value();
2501 break;
2502
2503 case Symbol::IS_UNDEFINED:
2504 value = 0;
2505 break;
2506
2507 default:
2508 gold_unreachable();
2509 }
2510
2511 *pstatus = CFVS_OK;
2512 return value;
2513 }
2514
2515 // Finalize the symbol SYM. This returns true if the symbol should be
2516 // added to the symbol table, false otherwise.
2517
2518 template<int size>
2519 bool
2520 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2521 {
2522 typedef typename Sized_symbol<size>::Value_type Value_type;
2523
2524 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2525
2526 // The default version of a symbol may appear twice in the symbol
2527 // table. We only need to finalize it once.
2528 if (sym->has_symtab_index())
2529 return false;
2530
2531 if (!sym->in_reg())
2532 {
2533 gold_assert(!sym->has_symtab_index());
2534 sym->set_symtab_index(-1U);
2535 gold_assert(sym->dynsym_index() == -1U);
2536 return false;
2537 }
2538
2539 // Compute final symbol value.
2540 Compute_final_value_status status;
2541 Value_type value = this->compute_final_value(sym, &status);
2542
2543 switch (status)
2544 {
2545 case CFVS_OK:
2546 break;
2547 case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2548 {
2549 bool is_ordinary;
2550 unsigned int shndx = sym->shndx(&is_ordinary);
2551 gold_error(_("%s: unsupported symbol section 0x%x"),
2552 sym->demangled_name().c_str(), shndx);
2553 }
2554 break;
2555 case CFVS_NO_OUTPUT_SECTION:
2556 sym->set_symtab_index(-1U);
2557 return false;
2558 default:
2559 gold_unreachable();
2560 }
2561
2562 sym->set_value(value);
2563
2564 if (parameters->options().strip_all()
2565 || !parameters->options().should_retain_symbol(sym->name()))
2566 {
2567 sym->set_symtab_index(-1U);
2568 return false;
2569 }
2570
2571 return true;
2572 }
2573
2574 // Write out the global symbols.
2575
2576 void
2577 Symbol_table::write_globals(const Stringpool* sympool,
2578 const Stringpool* dynpool,
2579 Output_symtab_xindex* symtab_xindex,
2580 Output_symtab_xindex* dynsym_xindex,
2581 Output_file* of) const
2582 {
2583 switch (parameters->size_and_endianness())
2584 {
2585 #ifdef HAVE_TARGET_32_LITTLE
2586 case Parameters::TARGET_32_LITTLE:
2587 this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2588 dynsym_xindex, of);
2589 break;
2590 #endif
2591 #ifdef HAVE_TARGET_32_BIG
2592 case Parameters::TARGET_32_BIG:
2593 this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2594 dynsym_xindex, of);
2595 break;
2596 #endif
2597 #ifdef HAVE_TARGET_64_LITTLE
2598 case Parameters::TARGET_64_LITTLE:
2599 this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2600 dynsym_xindex, of);
2601 break;
2602 #endif
2603 #ifdef HAVE_TARGET_64_BIG
2604 case Parameters::TARGET_64_BIG:
2605 this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2606 dynsym_xindex, of);
2607 break;
2608 #endif
2609 default:
2610 gold_unreachable();
2611 }
2612 }
2613
2614 // Write out the global symbols.
2615
2616 template<int size, bool big_endian>
2617 void
2618 Symbol_table::sized_write_globals(const Stringpool* sympool,
2619 const Stringpool* dynpool,
2620 Output_symtab_xindex* symtab_xindex,
2621 Output_symtab_xindex* dynsym_xindex,
2622 Output_file* of) const
2623 {
2624 const Target& target = parameters->target();
2625
2626 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2627
2628 const unsigned int output_count = this->output_count_;
2629 const section_size_type oview_size = output_count * sym_size;
2630 const unsigned int first_global_index = this->first_global_index_;
2631 unsigned char* psyms;
2632 if (this->offset_ == 0 || output_count == 0)
2633 psyms = NULL;
2634 else
2635 psyms = of->get_output_view(this->offset_, oview_size);
2636
2637 const unsigned int dynamic_count = this->dynamic_count_;
2638 const section_size_type dynamic_size = dynamic_count * sym_size;
2639 const unsigned int first_dynamic_global_index =
2640 this->first_dynamic_global_index_;
2641 unsigned char* dynamic_view;
2642 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2643 dynamic_view = NULL;
2644 else
2645 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2646
2647 for (Symbol_table_type::const_iterator p = this->table_.begin();
2648 p != this->table_.end();
2649 ++p)
2650 {
2651 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2652
2653 // Possibly warn about unresolved symbols in shared libraries.
2654 this->warn_about_undefined_dynobj_symbol(sym);
2655
2656 unsigned int sym_index = sym->symtab_index();
2657 unsigned int dynsym_index;
2658 if (dynamic_view == NULL)
2659 dynsym_index = -1U;
2660 else
2661 dynsym_index = sym->dynsym_index();
2662
2663 if (sym_index == -1U && dynsym_index == -1U)
2664 {
2665 // This symbol is not included in the output file.
2666 continue;
2667 }
2668
2669 unsigned int shndx;
2670 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2671 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2672 switch (sym->source())
2673 {
2674 case Symbol::FROM_OBJECT:
2675 {
2676 bool is_ordinary;
2677 unsigned int in_shndx = sym->shndx(&is_ordinary);
2678
2679 if (!is_ordinary
2680 && in_shndx != elfcpp::SHN_ABS
2681 && !Symbol::is_common_shndx(in_shndx))
2682 {
2683 gold_error(_("%s: unsupported symbol section 0x%x"),
2684 sym->demangled_name().c_str(), in_shndx);
2685 shndx = in_shndx;
2686 }
2687 else
2688 {
2689 Object* symobj = sym->object();
2690 if (symobj->is_dynamic())
2691 {
2692 if (sym->needs_dynsym_value())
2693 dynsym_value = target.dynsym_value(sym);
2694 shndx = elfcpp::SHN_UNDEF;
2695 }
2696 else if (symobj->pluginobj() != NULL)
2697 shndx = elfcpp::SHN_UNDEF;
2698 else if (in_shndx == elfcpp::SHN_UNDEF
2699 || (!is_ordinary
2700 && (in_shndx == elfcpp::SHN_ABS
2701 || Symbol::is_common_shndx(in_shndx))))
2702 shndx = in_shndx;
2703 else
2704 {
2705 Relobj* relobj = static_cast<Relobj*>(symobj);
2706 Output_section* os = relobj->output_section(in_shndx);
2707 if (this->is_section_folded(relobj, in_shndx))
2708 {
2709 // This global symbol must be written out even though
2710 // it is folded.
2711 // Get the os of the section it is folded onto.
2712 Section_id folded =
2713 this->icf_->get_folded_section(relobj, in_shndx);
2714 gold_assert(folded.first !=NULL);
2715 Relobj* folded_obj =
2716 reinterpret_cast<Relobj*>(folded.first);
2717 os = folded_obj->output_section(folded.second);
2718 gold_assert(os != NULL);
2719 }
2720 gold_assert(os != NULL);
2721 shndx = os->out_shndx();
2722
2723 if (shndx >= elfcpp::SHN_LORESERVE)
2724 {
2725 if (sym_index != -1U)
2726 symtab_xindex->add(sym_index, shndx);
2727 if (dynsym_index != -1U)
2728 dynsym_xindex->add(dynsym_index, shndx);
2729 shndx = elfcpp::SHN_XINDEX;
2730 }
2731
2732 // In object files symbol values are section
2733 // relative.
2734 if (parameters->options().relocatable())
2735 sym_value -= os->address();
2736 }
2737 }
2738 }
2739 break;
2740
2741 case Symbol::IN_OUTPUT_DATA:
2742 shndx = sym->output_data()->out_shndx();
2743 if (shndx >= elfcpp::SHN_LORESERVE)
2744 {
2745 if (sym_index != -1U)
2746 symtab_xindex->add(sym_index, shndx);
2747 if (dynsym_index != -1U)
2748 dynsym_xindex->add(dynsym_index, shndx);
2749 shndx = elfcpp::SHN_XINDEX;
2750 }
2751 break;
2752
2753 case Symbol::IN_OUTPUT_SEGMENT:
2754 shndx = elfcpp::SHN_ABS;
2755 break;
2756
2757 case Symbol::IS_CONSTANT:
2758 shndx = elfcpp::SHN_ABS;
2759 break;
2760
2761 case Symbol::IS_UNDEFINED:
2762 shndx = elfcpp::SHN_UNDEF;
2763 break;
2764
2765 default:
2766 gold_unreachable();
2767 }
2768
2769 if (sym_index != -1U)
2770 {
2771 sym_index -= first_global_index;
2772 gold_assert(sym_index < output_count);
2773 unsigned char* ps = psyms + (sym_index * sym_size);
2774 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2775 sympool, ps);
2776 }
2777
2778 if (dynsym_index != -1U)
2779 {
2780 dynsym_index -= first_dynamic_global_index;
2781 gold_assert(dynsym_index < dynamic_count);
2782 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2783 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2784 dynpool, pd);
2785 }
2786 }
2787
2788 of->write_output_view(this->offset_, oview_size, psyms);
2789 if (dynamic_view != NULL)
2790 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2791 }
2792
2793 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2794 // strtab holding the name.
2795
2796 template<int size, bool big_endian>
2797 void
2798 Symbol_table::sized_write_symbol(
2799 Sized_symbol<size>* sym,
2800 typename elfcpp::Elf_types<size>::Elf_Addr value,
2801 unsigned int shndx,
2802 const Stringpool* pool,
2803 unsigned char* p) const
2804 {
2805 elfcpp::Sym_write<size, big_endian> osym(p);
2806 osym.put_st_name(pool->get_offset(sym->name()));
2807 osym.put_st_value(value);
2808 // Use a symbol size of zero for undefined symbols from shared libraries.
2809 if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2810 osym.put_st_size(0);
2811 else
2812 osym.put_st_size(sym->symsize());
2813 elfcpp::STT type = sym->type();
2814 // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2815 if (type == elfcpp::STT_GNU_IFUNC
2816 && sym->is_from_dynobj())
2817 type = elfcpp::STT_FUNC;
2818 // A version script may have overridden the default binding.
2819 if (sym->is_forced_local())
2820 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2821 else
2822 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), type));
2823 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2824 osym.put_st_shndx(shndx);
2825 }
2826
2827 // Check for unresolved symbols in shared libraries. This is
2828 // controlled by the --allow-shlib-undefined option.
2829
2830 // We only warn about libraries for which we have seen all the
2831 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2832 // which were not seen in this link. If we didn't see a DT_NEEDED
2833 // entry, we aren't going to be able to reliably report whether the
2834 // symbol is undefined.
2835
2836 // We also don't warn about libraries found in a system library
2837 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2838 // are OK. This heuristic avoids problems on GNU/Linux, in which -ldl
2839 // can have undefined references satisfied by ld-linux.so.
2840
2841 inline void
2842 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2843 {
2844 bool dummy;
2845 if (sym->source() == Symbol::FROM_OBJECT
2846 && sym->object()->is_dynamic()
2847 && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2848 && sym->binding() != elfcpp::STB_WEAK
2849 && !parameters->options().allow_shlib_undefined()
2850 && !parameters->target().is_defined_by_abi(sym)
2851 && !sym->object()->is_in_system_directory())
2852 {
2853 // A very ugly cast.
2854 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2855 if (!dynobj->has_unknown_needed_entries())
2856 gold_undefined_symbol(sym);
2857 }
2858 }
2859
2860 // Write out a section symbol. Return the update offset.
2861
2862 void
2863 Symbol_table::write_section_symbol(const Output_section *os,
2864 Output_symtab_xindex* symtab_xindex,
2865 Output_file* of,
2866 off_t offset) const
2867 {
2868 switch (parameters->size_and_endianness())
2869 {
2870 #ifdef HAVE_TARGET_32_LITTLE
2871 case Parameters::TARGET_32_LITTLE:
2872 this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2873 offset);
2874 break;
2875 #endif
2876 #ifdef HAVE_TARGET_32_BIG
2877 case Parameters::TARGET_32_BIG:
2878 this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2879 offset);
2880 break;
2881 #endif
2882 #ifdef HAVE_TARGET_64_LITTLE
2883 case Parameters::TARGET_64_LITTLE:
2884 this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2885 offset);
2886 break;
2887 #endif
2888 #ifdef HAVE_TARGET_64_BIG
2889 case Parameters::TARGET_64_BIG:
2890 this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2891 offset);
2892 break;
2893 #endif
2894 default:
2895 gold_unreachable();
2896 }
2897 }
2898
2899 // Write out a section symbol, specialized for size and endianness.
2900
2901 template<int size, bool big_endian>
2902 void
2903 Symbol_table::sized_write_section_symbol(const Output_section* os,
2904 Output_symtab_xindex* symtab_xindex,
2905 Output_file* of,
2906 off_t offset) const
2907 {
2908 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2909
2910 unsigned char* pov = of->get_output_view(offset, sym_size);
2911
2912 elfcpp::Sym_write<size, big_endian> osym(pov);
2913 osym.put_st_name(0);
2914 if (parameters->options().relocatable())
2915 osym.put_st_value(0);
2916 else
2917 osym.put_st_value(os->address());
2918 osym.put_st_size(0);
2919 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2920 elfcpp::STT_SECTION));
2921 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2922
2923 unsigned int shndx = os->out_shndx();
2924 if (shndx >= elfcpp::SHN_LORESERVE)
2925 {
2926 symtab_xindex->add(os->symtab_index(), shndx);
2927 shndx = elfcpp::SHN_XINDEX;
2928 }
2929 osym.put_st_shndx(shndx);
2930
2931 of->write_output_view(offset, sym_size, pov);
2932 }
2933
2934 // Print statistical information to stderr. This is used for --stats.
2935
2936 void
2937 Symbol_table::print_stats() const
2938 {
2939 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2940 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2941 program_name, this->table_.size(), this->table_.bucket_count());
2942 #else
2943 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2944 program_name, this->table_.size());
2945 #endif
2946 this->namepool_.print_stats("symbol table stringpool");
2947 }
2948
2949 // We check for ODR violations by looking for symbols with the same
2950 // name for which the debugging information reports that they were
2951 // defined in different source locations. When comparing the source
2952 // location, we consider instances with the same base filename and
2953 // line number to be the same. This is because different object
2954 // files/shared libraries can include the same header file using
2955 // different paths, and we don't want to report an ODR violation in
2956 // that case.
2957
2958 // This struct is used to compare line information, as returned by
2959 // Dwarf_line_info::one_addr2line. It implements a < comparison
2960 // operator used with std::set.
2961
2962 struct Odr_violation_compare
2963 {
2964 bool
2965 operator()(const std::string& s1, const std::string& s2) const
2966 {
2967 std::string::size_type pos1 = s1.rfind('/');
2968 std::string::size_type pos2 = s2.rfind('/');
2969 if (pos1 == std::string::npos
2970 || pos2 == std::string::npos)
2971 return s1 < s2;
2972 return s1.compare(pos1, std::string::npos,
2973 s2, pos2, std::string::npos) < 0;
2974 }
2975 };
2976
2977 // Check candidate_odr_violations_ to find symbols with the same name
2978 // but apparently different definitions (different source-file/line-no).
2979
2980 void
2981 Symbol_table::detect_odr_violations(const Task* task,
2982 const char* output_file_name) const
2983 {
2984 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2985 it != candidate_odr_violations_.end();
2986 ++it)
2987 {
2988 const char* symbol_name = it->first;
2989 // We use a sorted set so the output is deterministic.
2990 std::set<std::string, Odr_violation_compare> line_nums;
2991
2992 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2993 locs = it->second.begin();
2994 locs != it->second.end();
2995 ++locs)
2996 {
2997 // We need to lock the object in order to read it. This
2998 // means that we have to run in a singleton Task. If we
2999 // want to run this in a general Task for better
3000 // performance, we will need one Task for object, plus
3001 // appropriate locking to ensure that we don't conflict with
3002 // other uses of the object. Also note, one_addr2line is not
3003 // currently thread-safe.
3004 Task_lock_obj<Object> tl(task, locs->object);
3005 // 16 is the size of the object-cache that one_addr2line should use.
3006 std::string lineno = Dwarf_line_info::one_addr2line(
3007 locs->object, locs->shndx, locs->offset, 16);
3008 if (!lineno.empty())
3009 line_nums.insert(lineno);
3010 }
3011
3012 if (line_nums.size() > 1)
3013 {
3014 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3015 "places (possible ODR violation):"),
3016 output_file_name, demangle(symbol_name).c_str());
3017 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
3018 it2 != line_nums.end();
3019 ++it2)
3020 fprintf(stderr, " %s\n", it2->c_str());
3021 }
3022 }
3023 // We only call one_addr2line() in this function, so we can clear its cache.
3024 Dwarf_line_info::clear_addr2line_cache();
3025 }
3026
3027 // Warnings functions.
3028
3029 // Add a new warning.
3030
3031 void
3032 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3033 const std::string& warning)
3034 {
3035 name = symtab->canonicalize_name(name);
3036 this->warnings_[name].set(obj, warning);
3037 }
3038
3039 // Look through the warnings and mark the symbols for which we should
3040 // warn. This is called during Layout::finalize when we know the
3041 // sources for all the symbols.
3042
3043 void
3044 Warnings::note_warnings(Symbol_table* symtab)
3045 {
3046 for (Warning_table::iterator p = this->warnings_.begin();
3047 p != this->warnings_.end();
3048 ++p)
3049 {
3050 Symbol* sym = symtab->lookup(p->first, NULL);
3051 if (sym != NULL
3052 && sym->source() == Symbol::FROM_OBJECT
3053 && sym->object() == p->second.object)
3054 sym->set_has_warning();
3055 }
3056 }
3057
3058 // Issue a warning. This is called when we see a relocation against a
3059 // symbol for which has a warning.
3060
3061 template<int size, bool big_endian>
3062 void
3063 Warnings::issue_warning(const Symbol* sym,
3064 const Relocate_info<size, big_endian>* relinfo,
3065 size_t relnum, off_t reloffset) const
3066 {
3067 gold_assert(sym->has_warning());
3068 Warning_table::const_iterator p = this->warnings_.find(sym->name());
3069 gold_assert(p != this->warnings_.end());
3070 gold_warning_at_location(relinfo, relnum, reloffset,
3071 "%s", p->second.text.c_str());
3072 }
3073
3074 // Instantiate the templates we need. We could use the configure
3075 // script to restrict this to only the ones needed for implemented
3076 // targets.
3077
3078 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3079 template
3080 void
3081 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3082 #endif
3083
3084 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3085 template
3086 void
3087 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3088 #endif
3089
3090 #ifdef HAVE_TARGET_32_LITTLE
3091 template
3092 void
3093 Symbol_table::add_from_relobj<32, false>(
3094 Sized_relobj<32, false>* relobj,
3095 const unsigned char* syms,
3096 size_t count,
3097 size_t symndx_offset,
3098 const char* sym_names,
3099 size_t sym_name_size,
3100 Sized_relobj<32, false>::Symbols* sympointers,
3101 size_t* defined);
3102 #endif
3103
3104 #ifdef HAVE_TARGET_32_BIG
3105 template
3106 void
3107 Symbol_table::add_from_relobj<32, true>(
3108 Sized_relobj<32, true>* relobj,
3109 const unsigned char* syms,
3110 size_t count,
3111 size_t symndx_offset,
3112 const char* sym_names,
3113 size_t sym_name_size,
3114 Sized_relobj<32, true>::Symbols* sympointers,
3115 size_t* defined);
3116 #endif
3117
3118 #ifdef HAVE_TARGET_64_LITTLE
3119 template
3120 void
3121 Symbol_table::add_from_relobj<64, false>(
3122 Sized_relobj<64, false>* relobj,
3123 const unsigned char* syms,
3124 size_t count,
3125 size_t symndx_offset,
3126 const char* sym_names,
3127 size_t sym_name_size,
3128 Sized_relobj<64, false>::Symbols* sympointers,
3129 size_t* defined);
3130 #endif
3131
3132 #ifdef HAVE_TARGET_64_BIG
3133 template
3134 void
3135 Symbol_table::add_from_relobj<64, true>(
3136 Sized_relobj<64, true>* relobj,
3137 const unsigned char* syms,
3138 size_t count,
3139 size_t symndx_offset,
3140 const char* sym_names,
3141 size_t sym_name_size,
3142 Sized_relobj<64, true>::Symbols* sympointers,
3143 size_t* defined);
3144 #endif
3145
3146 #ifdef HAVE_TARGET_32_LITTLE
3147 template
3148 Symbol*
3149 Symbol_table::add_from_pluginobj<32, false>(
3150 Sized_pluginobj<32, false>* obj,
3151 const char* name,
3152 const char* ver,
3153 elfcpp::Sym<32, false>* sym);
3154 #endif
3155
3156 #ifdef HAVE_TARGET_32_BIG
3157 template
3158 Symbol*
3159 Symbol_table::add_from_pluginobj<32, true>(
3160 Sized_pluginobj<32, true>* obj,
3161 const char* name,
3162 const char* ver,
3163 elfcpp::Sym<32, true>* sym);
3164 #endif
3165
3166 #ifdef HAVE_TARGET_64_LITTLE
3167 template
3168 Symbol*
3169 Symbol_table::add_from_pluginobj<64, false>(
3170 Sized_pluginobj<64, false>* obj,
3171 const char* name,
3172 const char* ver,
3173 elfcpp::Sym<64, false>* sym);
3174 #endif
3175
3176 #ifdef HAVE_TARGET_64_BIG
3177 template
3178 Symbol*
3179 Symbol_table::add_from_pluginobj<64, true>(
3180 Sized_pluginobj<64, true>* obj,
3181 const char* name,
3182 const char* ver,
3183 elfcpp::Sym<64, true>* sym);
3184 #endif
3185
3186 #ifdef HAVE_TARGET_32_LITTLE
3187 template
3188 void
3189 Symbol_table::add_from_dynobj<32, false>(
3190 Sized_dynobj<32, false>* dynobj,
3191 const unsigned char* syms,
3192 size_t count,
3193 const char* sym_names,
3194 size_t sym_name_size,
3195 const unsigned char* versym,
3196 size_t versym_size,
3197 const std::vector<const char*>* version_map,
3198 Sized_relobj<32, false>::Symbols* sympointers,
3199 size_t* defined);
3200 #endif
3201
3202 #ifdef HAVE_TARGET_32_BIG
3203 template
3204 void
3205 Symbol_table::add_from_dynobj<32, true>(
3206 Sized_dynobj<32, true>* dynobj,
3207 const unsigned char* syms,
3208 size_t count,
3209 const char* sym_names,
3210 size_t sym_name_size,
3211 const unsigned char* versym,
3212 size_t versym_size,
3213 const std::vector<const char*>* version_map,
3214 Sized_relobj<32, true>::Symbols* sympointers,
3215 size_t* defined);
3216 #endif
3217
3218 #ifdef HAVE_TARGET_64_LITTLE
3219 template
3220 void
3221 Symbol_table::add_from_dynobj<64, false>(
3222 Sized_dynobj<64, false>* dynobj,
3223 const unsigned char* syms,
3224 size_t count,
3225 const char* sym_names,
3226 size_t sym_name_size,
3227 const unsigned char* versym,
3228 size_t versym_size,
3229 const std::vector<const char*>* version_map,
3230 Sized_relobj<64, false>::Symbols* sympointers,
3231 size_t* defined);
3232 #endif
3233
3234 #ifdef HAVE_TARGET_64_BIG
3235 template
3236 void
3237 Symbol_table::add_from_dynobj<64, true>(
3238 Sized_dynobj<64, true>* dynobj,
3239 const unsigned char* syms,
3240 size_t count,
3241 const char* sym_names,
3242 size_t sym_name_size,
3243 const unsigned char* versym,
3244 size_t versym_size,
3245 const std::vector<const char*>* version_map,
3246 Sized_relobj<64, true>::Symbols* sympointers,
3247 size_t* defined);
3248 #endif
3249
3250 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3251 template
3252 void
3253 Symbol_table::define_with_copy_reloc<32>(
3254 Sized_symbol<32>* sym,
3255 Output_data* posd,
3256 elfcpp::Elf_types<32>::Elf_Addr value);
3257 #endif
3258
3259 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3260 template
3261 void
3262 Symbol_table::define_with_copy_reloc<64>(
3263 Sized_symbol<64>* sym,
3264 Output_data* posd,
3265 elfcpp::Elf_types<64>::Elf_Addr value);
3266 #endif
3267
3268 #ifdef HAVE_TARGET_32_LITTLE
3269 template
3270 void
3271 Warnings::issue_warning<32, false>(const Symbol* sym,
3272 const Relocate_info<32, false>* relinfo,
3273 size_t relnum, off_t reloffset) const;
3274 #endif
3275
3276 #ifdef HAVE_TARGET_32_BIG
3277 template
3278 void
3279 Warnings::issue_warning<32, true>(const Symbol* sym,
3280 const Relocate_info<32, true>* relinfo,
3281 size_t relnum, off_t reloffset) const;
3282 #endif
3283
3284 #ifdef HAVE_TARGET_64_LITTLE
3285 template
3286 void
3287 Warnings::issue_warning<64, false>(const Symbol* sym,
3288 const Relocate_info<64, false>* relinfo,
3289 size_t relnum, off_t reloffset) const;
3290 #endif
3291
3292 #ifdef HAVE_TARGET_64_BIG
3293 template
3294 void
3295 Warnings::issue_warning<64, true>(const Symbol* sym,
3296 const Relocate_info<64, true>* relinfo,
3297 size_t relnum, off_t reloffset) const;
3298 #endif
3299
3300 } // End namespace gold.
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