* errors.cc (Errors::info): New function.
[binutils-gdb.git] / gold / symtab.cc
1 // symtab.cc -- the gold symbol table
2
3 // Copyright 2006, 2007, 2008 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 "object.h"
34 #include "dwarf_reader.h"
35 #include "dynobj.h"
36 #include "output.h"
37 #include "target.h"
38 #include "workqueue.h"
39 #include "symtab.h"
40
41 namespace gold
42 {
43
44 // Class Symbol.
45
46 // Initialize fields in Symbol. This initializes everything except u_
47 // and source_.
48
49 void
50 Symbol::init_fields(const char* name, const char* version,
51 elfcpp::STT type, elfcpp::STB binding,
52 elfcpp::STV visibility, unsigned char nonvis)
53 {
54 this->name_ = name;
55 this->version_ = version;
56 this->symtab_index_ = 0;
57 this->dynsym_index_ = 0;
58 this->got_offsets_.init();
59 this->plt_offset_ = 0;
60 this->type_ = type;
61 this->binding_ = binding;
62 this->visibility_ = visibility;
63 this->nonvis_ = nonvis;
64 this->is_target_special_ = false;
65 this->is_def_ = false;
66 this->is_forwarder_ = false;
67 this->has_alias_ = false;
68 this->needs_dynsym_entry_ = false;
69 this->in_reg_ = false;
70 this->in_dyn_ = false;
71 this->has_plt_offset_ = false;
72 this->has_warning_ = false;
73 this->is_copied_from_dynobj_ = false;
74 this->is_forced_local_ = false;
75 }
76
77 // Return the demangled version of the symbol's name, but only
78 // if the --demangle flag was set.
79
80 static std::string
81 demangle(const char* name)
82 {
83 if (!parameters->options().do_demangle())
84 return name;
85
86 // cplus_demangle allocates memory for the result it returns,
87 // and returns NULL if the name is already demangled.
88 char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
89 if (demangled_name == NULL)
90 return name;
91
92 std::string retval(demangled_name);
93 free(demangled_name);
94 return retval;
95 }
96
97 std::string
98 Symbol::demangled_name() const
99 {
100 return demangle(this->name());
101 }
102
103 // Initialize the fields in the base class Symbol for SYM in OBJECT.
104
105 template<int size, bool big_endian>
106 void
107 Symbol::init_base(const char* name, const char* version, Object* object,
108 const elfcpp::Sym<size, big_endian>& sym)
109 {
110 this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
111 sym.get_st_visibility(), sym.get_st_nonvis());
112 this->u_.from_object.object = object;
113 // FIXME: Handle SHN_XINDEX.
114 this->u_.from_object.shndx = sym.get_st_shndx();
115 this->source_ = FROM_OBJECT;
116 this->in_reg_ = !object->is_dynamic();
117 this->in_dyn_ = object->is_dynamic();
118 }
119
120 // Initialize the fields in the base class Symbol for a symbol defined
121 // in an Output_data.
122
123 void
124 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
125 elfcpp::STB binding, elfcpp::STV visibility,
126 unsigned char nonvis, bool offset_is_from_end)
127 {
128 this->init_fields(name, NULL, type, binding, visibility, nonvis);
129 this->u_.in_output_data.output_data = od;
130 this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
131 this->source_ = IN_OUTPUT_DATA;
132 this->in_reg_ = true;
133 }
134
135 // Initialize the fields in the base class Symbol for a symbol defined
136 // in an Output_segment.
137
138 void
139 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
140 elfcpp::STB binding, elfcpp::STV visibility,
141 unsigned char nonvis, Segment_offset_base offset_base)
142 {
143 this->init_fields(name, NULL, type, binding, visibility, nonvis);
144 this->u_.in_output_segment.output_segment = os;
145 this->u_.in_output_segment.offset_base = offset_base;
146 this->source_ = IN_OUTPUT_SEGMENT;
147 this->in_reg_ = true;
148 }
149
150 // Initialize the fields in the base class Symbol for a symbol defined
151 // as a constant.
152
153 void
154 Symbol::init_base(const char* name, elfcpp::STT type,
155 elfcpp::STB binding, elfcpp::STV visibility,
156 unsigned char nonvis)
157 {
158 this->init_fields(name, NULL, type, binding, visibility, nonvis);
159 this->source_ = CONSTANT;
160 this->in_reg_ = true;
161 }
162
163 // Allocate a common symbol in the base.
164
165 void
166 Symbol::allocate_base_common(Output_data* od)
167 {
168 gold_assert(this->is_common());
169 this->source_ = IN_OUTPUT_DATA;
170 this->u_.in_output_data.output_data = od;
171 this->u_.in_output_data.offset_is_from_end = false;
172 }
173
174 // Initialize the fields in Sized_symbol for SYM in OBJECT.
175
176 template<int size>
177 template<bool big_endian>
178 void
179 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
180 const elfcpp::Sym<size, big_endian>& sym)
181 {
182 this->init_base(name, version, object, sym);
183 this->value_ = sym.get_st_value();
184 this->symsize_ = sym.get_st_size();
185 }
186
187 // Initialize the fields in Sized_symbol for a symbol defined in an
188 // Output_data.
189
190 template<int size>
191 void
192 Sized_symbol<size>::init(const char* name, Output_data* od,
193 Value_type value, Size_type symsize,
194 elfcpp::STT type, elfcpp::STB binding,
195 elfcpp::STV visibility, unsigned char nonvis,
196 bool offset_is_from_end)
197 {
198 this->init_base(name, od, type, binding, visibility, nonvis,
199 offset_is_from_end);
200 this->value_ = value;
201 this->symsize_ = symsize;
202 }
203
204 // Initialize the fields in Sized_symbol for a symbol defined in an
205 // Output_segment.
206
207 template<int size>
208 void
209 Sized_symbol<size>::init(const char* name, Output_segment* os,
210 Value_type value, Size_type symsize,
211 elfcpp::STT type, elfcpp::STB binding,
212 elfcpp::STV visibility, unsigned char nonvis,
213 Segment_offset_base offset_base)
214 {
215 this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
216 this->value_ = value;
217 this->symsize_ = symsize;
218 }
219
220 // Initialize the fields in Sized_symbol for a symbol defined as a
221 // constant.
222
223 template<int size>
224 void
225 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
226 elfcpp::STT type, elfcpp::STB binding,
227 elfcpp::STV visibility, unsigned char nonvis)
228 {
229 this->init_base(name, type, binding, visibility, nonvis);
230 this->value_ = value;
231 this->symsize_ = symsize;
232 }
233
234 // Allocate a common symbol.
235
236 template<int size>
237 void
238 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
239 {
240 this->allocate_base_common(od);
241 this->value_ = value;
242 }
243
244 // Return true if this symbol should be added to the dynamic symbol
245 // table.
246
247 inline bool
248 Symbol::should_add_dynsym_entry() const
249 {
250 // If the symbol is used by a dynamic relocation, we need to add it.
251 if (this->needs_dynsym_entry())
252 return true;
253
254 // If the symbol was forced local in a version script, do not add it.
255 if (this->is_forced_local())
256 return false;
257
258 // If exporting all symbols or building a shared library,
259 // and the symbol is defined in a regular object and is
260 // externally visible, we need to add it.
261 if ((parameters->options().export_dynamic() || parameters->options().shared())
262 && !this->is_from_dynobj()
263 && this->is_externally_visible())
264 return true;
265
266 return false;
267 }
268
269 // Return true if the final value of this symbol is known at link
270 // time.
271
272 bool
273 Symbol::final_value_is_known() const
274 {
275 // If we are not generating an executable, then no final values are
276 // known, since they will change at runtime.
277 if (parameters->options().shared() || parameters->options().relocatable())
278 return false;
279
280 // If the symbol is not from an object file, then it is defined, and
281 // known.
282 if (this->source_ != FROM_OBJECT)
283 return true;
284
285 // If the symbol is from a dynamic object, then the final value is
286 // not known.
287 if (this->object()->is_dynamic())
288 return false;
289
290 // If the symbol is not undefined (it is defined or common), then
291 // the final value is known.
292 if (!this->is_undefined())
293 return true;
294
295 // If the symbol is undefined, then whether the final value is known
296 // depends on whether we are doing a static link. If we are doing a
297 // dynamic link, then the final value could be filled in at runtime.
298 // This could reasonably be the case for a weak undefined symbol.
299 return parameters->doing_static_link();
300 }
301
302 // Return the output section where this symbol is defined.
303
304 Output_section*
305 Symbol::output_section() const
306 {
307 switch (this->source_)
308 {
309 case FROM_OBJECT:
310 {
311 unsigned int shndx = this->u_.from_object.shndx;
312 if (shndx != elfcpp::SHN_UNDEF && shndx < elfcpp::SHN_LORESERVE)
313 {
314 gold_assert(!this->u_.from_object.object->is_dynamic());
315 Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
316 section_offset_type dummy;
317 return relobj->output_section(shndx, &dummy);
318 }
319 return NULL;
320 }
321
322 case IN_OUTPUT_DATA:
323 return this->u_.in_output_data.output_data->output_section();
324
325 case IN_OUTPUT_SEGMENT:
326 case CONSTANT:
327 return NULL;
328
329 default:
330 gold_unreachable();
331 }
332 }
333
334 // Set the symbol's output section. This is used for symbols defined
335 // in scripts. This should only be called after the symbol table has
336 // been finalized.
337
338 void
339 Symbol::set_output_section(Output_section* os)
340 {
341 switch (this->source_)
342 {
343 case FROM_OBJECT:
344 case IN_OUTPUT_DATA:
345 gold_assert(this->output_section() == os);
346 break;
347 case CONSTANT:
348 this->source_ = IN_OUTPUT_DATA;
349 this->u_.in_output_data.output_data = os;
350 this->u_.in_output_data.offset_is_from_end = false;
351 break;
352 case IN_OUTPUT_SEGMENT:
353 default:
354 gold_unreachable();
355 }
356 }
357
358 // Class Symbol_table.
359
360 Symbol_table::Symbol_table(unsigned int count,
361 const Version_script_info& version_script)
362 : saw_undefined_(0), offset_(0), table_(count), namepool_(),
363 forwarders_(), commons_(), tls_commons_(), forced_locals_(), warnings_(),
364 version_script_(version_script)
365 {
366 namepool_.reserve(count);
367 }
368
369 Symbol_table::~Symbol_table()
370 {
371 }
372
373 // The hash function. The key values are Stringpool keys.
374
375 inline size_t
376 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
377 {
378 return key.first ^ key.second;
379 }
380
381 // The symbol table key equality function. This is called with
382 // Stringpool keys.
383
384 inline bool
385 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
386 const Symbol_table_key& k2) const
387 {
388 return k1.first == k2.first && k1.second == k2.second;
389 }
390
391 // Make TO a symbol which forwards to FROM.
392
393 void
394 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
395 {
396 gold_assert(from != to);
397 gold_assert(!from->is_forwarder() && !to->is_forwarder());
398 this->forwarders_[from] = to;
399 from->set_forwarder();
400 }
401
402 // Resolve the forwards from FROM, returning the real symbol.
403
404 Symbol*
405 Symbol_table::resolve_forwards(const Symbol* from) const
406 {
407 gold_assert(from->is_forwarder());
408 Unordered_map<const Symbol*, Symbol*>::const_iterator p =
409 this->forwarders_.find(from);
410 gold_assert(p != this->forwarders_.end());
411 return p->second;
412 }
413
414 // Look up a symbol by name.
415
416 Symbol*
417 Symbol_table::lookup(const char* name, const char* version) const
418 {
419 Stringpool::Key name_key;
420 name = this->namepool_.find(name, &name_key);
421 if (name == NULL)
422 return NULL;
423
424 Stringpool::Key version_key = 0;
425 if (version != NULL)
426 {
427 version = this->namepool_.find(version, &version_key);
428 if (version == NULL)
429 return NULL;
430 }
431
432 Symbol_table_key key(name_key, version_key);
433 Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
434 if (p == this->table_.end())
435 return NULL;
436 return p->second;
437 }
438
439 // Resolve a Symbol with another Symbol. This is only used in the
440 // unusual case where there are references to both an unversioned
441 // symbol and a symbol with a version, and we then discover that that
442 // version is the default version. Because this is unusual, we do
443 // this the slow way, by converting back to an ELF symbol.
444
445 template<int size, bool big_endian>
446 void
447 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
448 const char* version)
449 {
450 unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
451 elfcpp::Sym_write<size, big_endian> esym(buf);
452 // We don't bother to set the st_name field.
453 esym.put_st_value(from->value());
454 esym.put_st_size(from->symsize());
455 esym.put_st_info(from->binding(), from->type());
456 esym.put_st_other(from->visibility(), from->nonvis());
457 esym.put_st_shndx(from->shndx());
458 this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
459 if (from->in_reg())
460 to->set_in_reg();
461 if (from->in_dyn())
462 to->set_in_dyn();
463 }
464
465 // Record that a symbol is forced to be local by a version script.
466
467 void
468 Symbol_table::force_local(Symbol* sym)
469 {
470 if (!sym->is_defined() && !sym->is_common())
471 return;
472 if (sym->is_forced_local())
473 {
474 // We already got this one.
475 return;
476 }
477 sym->set_is_forced_local();
478 this->forced_locals_.push_back(sym);
479 }
480
481 // Adjust NAME for wrapping, and update *NAME_KEY if necessary. This
482 // is only called for undefined symbols, when at least one --wrap
483 // option was used.
484
485 const char*
486 Symbol_table::wrap_symbol(Object* object, const char* name,
487 Stringpool::Key* name_key)
488 {
489 // For some targets, we need to ignore a specific character when
490 // wrapping, and add it back later.
491 char prefix = '\0';
492 if (name[0] == object->target()->wrap_char())
493 {
494 prefix = name[0];
495 ++name;
496 }
497
498 if (parameters->options().is_wrap(name))
499 {
500 // Turn NAME into __wrap_NAME.
501 std::string s;
502 if (prefix != '\0')
503 s += prefix;
504 s += "__wrap_";
505 s += name;
506
507 // This will give us both the old and new name in NAMEPOOL_, but
508 // that is OK. Only the versions we need will wind up in the
509 // real string table in the output file.
510 return this->namepool_.add(s.c_str(), true, name_key);
511 }
512
513 const char* const real_prefix = "__real_";
514 const size_t real_prefix_length = strlen(real_prefix);
515 if (strncmp(name, real_prefix, real_prefix_length) == 0
516 && parameters->options().is_wrap(name + real_prefix_length))
517 {
518 // Turn __real_NAME into NAME.
519 std::string s;
520 if (prefix != '\0')
521 s += prefix;
522 s += name + real_prefix_length;
523 return this->namepool_.add(s.c_str(), true, name_key);
524 }
525
526 return name;
527 }
528
529 // Add one symbol from OBJECT to the symbol table. NAME is symbol
530 // name and VERSION is the version; both are canonicalized. DEF is
531 // whether this is the default version.
532
533 // If DEF is true, then this is the definition of a default version of
534 // a symbol. That means that any lookup of NAME/NULL and any lookup
535 // of NAME/VERSION should always return the same symbol. This is
536 // obvious for references, but in particular we want to do this for
537 // definitions: overriding NAME/NULL should also override
538 // NAME/VERSION. If we don't do that, it would be very hard to
539 // override functions in a shared library which uses versioning.
540
541 // We implement this by simply making both entries in the hash table
542 // point to the same Symbol structure. That is easy enough if this is
543 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
544 // that we have seen both already, in which case they will both have
545 // independent entries in the symbol table. We can't simply change
546 // the symbol table entry, because we have pointers to the entries
547 // attached to the object files. So we mark the entry attached to the
548 // object file as a forwarder, and record it in the forwarders_ map.
549 // Note that entries in the hash table will never be marked as
550 // forwarders.
551 //
552 // SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
553 // symbol exactly as it existed in the input file. SYM is usually
554 // that as well, but can be modified, for instance if we determine
555 // it's in a to-be-discarded section.
556
557 template<int size, bool big_endian>
558 Sized_symbol<size>*
559 Symbol_table::add_from_object(Object* object,
560 const char *name,
561 Stringpool::Key name_key,
562 const char *version,
563 Stringpool::Key version_key,
564 bool def,
565 const elfcpp::Sym<size, big_endian>& sym,
566 const elfcpp::Sym<size, big_endian>& orig_sym)
567 {
568 // Print a message if this symbol is being traced.
569 if (parameters->options().is_trace_symbol(name))
570 {
571 if (orig_sym.get_st_shndx() == elfcpp::SHN_UNDEF)
572 gold_info(_("%s: reference to %s"), object->name().c_str(), name);
573 else
574 gold_info(_("%s: definition of %s"), object->name().c_str(), name);
575 }
576
577 // For an undefined symbol, we may need to adjust the name using
578 // --wrap.
579 if (orig_sym.get_st_shndx() == elfcpp::SHN_UNDEF
580 && parameters->options().any_wrap())
581 {
582 const char* wrap_name = this->wrap_symbol(object, name, &name_key);
583 if (wrap_name != name)
584 {
585 // If we see a reference to malloc with version GLIBC_2.0,
586 // and we turn it into a reference to __wrap_malloc, then we
587 // discard the version number. Otherwise the user would be
588 // required to specify the correct version for
589 // __wrap_malloc.
590 version = NULL;
591 version_key = 0;
592 name = wrap_name;
593 }
594 }
595
596 Symbol* const snull = NULL;
597 std::pair<typename Symbol_table_type::iterator, bool> ins =
598 this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
599 snull));
600
601 std::pair<typename Symbol_table_type::iterator, bool> insdef =
602 std::make_pair(this->table_.end(), false);
603 if (def)
604 {
605 const Stringpool::Key vnull_key = 0;
606 insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
607 vnull_key),
608 snull));
609 }
610
611 // ins.first: an iterator, which is a pointer to a pair.
612 // ins.first->first: the key (a pair of name and version).
613 // ins.first->second: the value (Symbol*).
614 // ins.second: true if new entry was inserted, false if not.
615
616 Sized_symbol<size>* ret;
617 bool was_undefined;
618 bool was_common;
619 if (!ins.second)
620 {
621 // We already have an entry for NAME/VERSION.
622 ret = this->get_sized_symbol<size>(ins.first->second);
623 gold_assert(ret != NULL);
624
625 was_undefined = ret->is_undefined();
626 was_common = ret->is_common();
627
628 this->resolve(ret, sym, orig_sym, object, version);
629
630 if (def)
631 {
632 if (insdef.second)
633 {
634 // This is the first time we have seen NAME/NULL. Make
635 // NAME/NULL point to NAME/VERSION.
636 insdef.first->second = ret;
637 }
638 else if (insdef.first->second != ret
639 && insdef.first->second->is_undefined())
640 {
641 // This is the unfortunate case where we already have
642 // entries for both NAME/VERSION and NAME/NULL. Note
643 // that we don't want to combine them if the existing
644 // symbol is going to override the new one. FIXME: We
645 // currently just test is_undefined, but this may not do
646 // the right thing if the existing symbol is from a
647 // shared library and the new one is from a regular
648 // object.
649
650 const Sized_symbol<size>* sym2;
651 sym2 = this->get_sized_symbol<size>(insdef.first->second);
652 Symbol_table::resolve<size, big_endian>(ret, sym2, version);
653 this->make_forwarder(insdef.first->second, ret);
654 insdef.first->second = ret;
655 }
656 else
657 def = false;
658 }
659 }
660 else
661 {
662 // This is the first time we have seen NAME/VERSION.
663 gold_assert(ins.first->second == NULL);
664
665 if (def && !insdef.second)
666 {
667 // We already have an entry for NAME/NULL. If we override
668 // it, then change it to NAME/VERSION.
669 ret = this->get_sized_symbol<size>(insdef.first->second);
670
671 was_undefined = ret->is_undefined();
672 was_common = ret->is_common();
673
674 this->resolve(ret, sym, orig_sym, object, version);
675 ins.first->second = ret;
676 }
677 else
678 {
679 was_undefined = false;
680 was_common = false;
681
682 Sized_target<size, big_endian>* target =
683 object->sized_target<size, big_endian>();
684 if (!target->has_make_symbol())
685 ret = new Sized_symbol<size>();
686 else
687 {
688 ret = target->make_symbol();
689 if (ret == NULL)
690 {
691 // This means that we don't want a symbol table
692 // entry after all.
693 if (!def)
694 this->table_.erase(ins.first);
695 else
696 {
697 this->table_.erase(insdef.first);
698 // Inserting insdef invalidated ins.
699 this->table_.erase(std::make_pair(name_key,
700 version_key));
701 }
702 return NULL;
703 }
704 }
705
706 ret->init(name, version, object, sym);
707
708 ins.first->second = ret;
709 if (def)
710 {
711 // This is the first time we have seen NAME/NULL. Point
712 // it at the new entry for NAME/VERSION.
713 gold_assert(insdef.second);
714 insdef.first->second = ret;
715 }
716 }
717 }
718
719 // Record every time we see a new undefined symbol, to speed up
720 // archive groups.
721 if (!was_undefined && ret->is_undefined())
722 ++this->saw_undefined_;
723
724 // Keep track of common symbols, to speed up common symbol
725 // allocation.
726 if (!was_common && ret->is_common())
727 {
728 if (ret->type() != elfcpp::STT_TLS)
729 this->commons_.push_back(ret);
730 else
731 this->tls_commons_.push_back(ret);
732 }
733
734 if (def)
735 ret->set_is_default();
736 return ret;
737 }
738
739 // Add all the symbols in a relocatable object to the hash table.
740
741 template<int size, bool big_endian>
742 void
743 Symbol_table::add_from_relobj(
744 Sized_relobj<size, big_endian>* relobj,
745 const unsigned char* syms,
746 size_t count,
747 const char* sym_names,
748 size_t sym_name_size,
749 typename Sized_relobj<size, big_endian>::Symbols* sympointers)
750 {
751 gold_assert(size == relobj->target()->get_size());
752 gold_assert(size == parameters->target().get_size());
753
754 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
755
756 const bool just_symbols = relobj->just_symbols();
757
758 const unsigned char* p = syms;
759 for (size_t i = 0; i < count; ++i, p += sym_size)
760 {
761 elfcpp::Sym<size, big_endian> sym(p);
762 elfcpp::Sym<size, big_endian>* psym = &sym;
763
764 unsigned int st_name = psym->get_st_name();
765 if (st_name >= sym_name_size)
766 {
767 relobj->error(_("bad global symbol name offset %u at %zu"),
768 st_name, i);
769 continue;
770 }
771
772 const char* name = sym_names + st_name;
773
774 // A symbol defined in a section which we are not including must
775 // be treated as an undefined symbol.
776 unsigned char symbuf[sym_size];
777 elfcpp::Sym<size, big_endian> sym2(symbuf);
778 unsigned int st_shndx = psym->get_st_shndx();
779 if (st_shndx != elfcpp::SHN_UNDEF
780 && st_shndx < elfcpp::SHN_LORESERVE
781 && !relobj->is_section_included(st_shndx))
782 {
783 memcpy(symbuf, p, sym_size);
784 elfcpp::Sym_write<size, big_endian> sw(symbuf);
785 sw.put_st_shndx(elfcpp::SHN_UNDEF);
786 psym = &sym2;
787 }
788
789 // In an object file, an '@' in the name separates the symbol
790 // name from the version name. If there are two '@' characters,
791 // this is the default version.
792 const char* ver = strchr(name, '@');
793 int namelen = 0;
794 // DEF: is the version default? LOCAL: is the symbol forced local?
795 bool def = false;
796 bool local = false;
797
798 if (ver != NULL)
799 {
800 // The symbol name is of the form foo@VERSION or foo@@VERSION
801 namelen = ver - name;
802 ++ver;
803 if (*ver == '@')
804 {
805 def = true;
806 ++ver;
807 }
808 }
809 // We don't want to assign a version to an undefined symbol,
810 // even if it is listed in the version script. FIXME: What
811 // about a common symbol?
812 else if (!version_script_.empty()
813 && psym->get_st_shndx() != elfcpp::SHN_UNDEF)
814 {
815 // The symbol name did not have a version, but
816 // the version script may assign a version anyway.
817 namelen = strlen(name);
818 def = true;
819 // Check the global: entries from the version script.
820 const std::string& version =
821 version_script_.get_symbol_version(name);
822 if (!version.empty())
823 ver = version.c_str();
824 // Check the local: entries from the version script
825 if (version_script_.symbol_is_local(name))
826 local = true;
827 }
828
829 if (just_symbols)
830 {
831 if (psym != &sym2)
832 memcpy(symbuf, p, sym_size);
833 elfcpp::Sym_write<size, big_endian> sw(symbuf);
834 sw.put_st_shndx(elfcpp::SHN_ABS);
835 if (st_shndx != elfcpp::SHN_UNDEF
836 && st_shndx < elfcpp::SHN_LORESERVE)
837 {
838 // Symbol values in object files are section relative.
839 // This is normally what we want, but since here we are
840 // converting the symbol to absolute we need to add the
841 // section address. The section address in an object
842 // file is normally zero, but people can use a linker
843 // script to change it.
844 sw.put_st_value(sym2.get_st_value()
845 + relobj->section_address(st_shndx));
846 }
847 psym = &sym2;
848 }
849
850 Sized_symbol<size>* res;
851 if (ver == NULL)
852 {
853 Stringpool::Key name_key;
854 name = this->namepool_.add(name, true, &name_key);
855 res = this->add_from_object(relobj, name, name_key, NULL, 0,
856 false, *psym, sym);
857 if (local)
858 this->force_local(res);
859 }
860 else
861 {
862 Stringpool::Key name_key;
863 name = this->namepool_.add_with_length(name, namelen, true,
864 &name_key);
865 Stringpool::Key ver_key;
866 ver = this->namepool_.add(ver, true, &ver_key);
867
868 res = this->add_from_object(relobj, name, name_key, ver, ver_key,
869 def, *psym, sym);
870 }
871
872 (*sympointers)[i] = res;
873 }
874 }
875
876 // Add all the symbols in a dynamic object to the hash table.
877
878 template<int size, bool big_endian>
879 void
880 Symbol_table::add_from_dynobj(
881 Sized_dynobj<size, big_endian>* dynobj,
882 const unsigned char* syms,
883 size_t count,
884 const char* sym_names,
885 size_t sym_name_size,
886 const unsigned char* versym,
887 size_t versym_size,
888 const std::vector<const char*>* version_map)
889 {
890 gold_assert(size == dynobj->target()->get_size());
891 gold_assert(size == parameters->target().get_size());
892
893 if (dynobj->just_symbols())
894 {
895 gold_error(_("--just-symbols does not make sense with a shared object"));
896 return;
897 }
898
899 if (versym != NULL && versym_size / 2 < count)
900 {
901 dynobj->error(_("too few symbol versions"));
902 return;
903 }
904
905 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
906
907 // We keep a list of all STT_OBJECT symbols, so that we can resolve
908 // weak aliases. This is necessary because if the dynamic object
909 // provides the same variable under two names, one of which is a
910 // weak definition, and the regular object refers to the weak
911 // definition, we have to put both the weak definition and the
912 // strong definition into the dynamic symbol table. Given a weak
913 // definition, the only way that we can find the corresponding
914 // strong definition, if any, is to search the symbol table.
915 std::vector<Sized_symbol<size>*> object_symbols;
916
917 const unsigned char* p = syms;
918 const unsigned char* vs = versym;
919 for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
920 {
921 elfcpp::Sym<size, big_endian> sym(p);
922
923 // Ignore symbols with local binding or that have
924 // internal or hidden visibility.
925 if (sym.get_st_bind() == elfcpp::STB_LOCAL
926 || sym.get_st_visibility() == elfcpp::STV_INTERNAL
927 || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
928 continue;
929
930 unsigned int st_name = sym.get_st_name();
931 if (st_name >= sym_name_size)
932 {
933 dynobj->error(_("bad symbol name offset %u at %zu"),
934 st_name, i);
935 continue;
936 }
937
938 const char* name = sym_names + st_name;
939
940 Sized_symbol<size>* res;
941
942 if (versym == NULL)
943 {
944 Stringpool::Key name_key;
945 name = this->namepool_.add(name, true, &name_key);
946 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
947 false, sym, sym);
948 }
949 else
950 {
951 // Read the version information.
952
953 unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
954
955 bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
956 v &= elfcpp::VERSYM_VERSION;
957
958 // The Sun documentation says that V can be VER_NDX_LOCAL,
959 // or VER_NDX_GLOBAL, or a version index. The meaning of
960 // VER_NDX_LOCAL is defined as "Symbol has local scope."
961 // The old GNU linker will happily generate VER_NDX_LOCAL
962 // for an undefined symbol. I don't know what the Sun
963 // linker will generate.
964
965 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
966 && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
967 {
968 // This symbol should not be visible outside the object.
969 continue;
970 }
971
972 // At this point we are definitely going to add this symbol.
973 Stringpool::Key name_key;
974 name = this->namepool_.add(name, true, &name_key);
975
976 if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
977 || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
978 {
979 // This symbol does not have a version.
980 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
981 false, sym, sym);
982 }
983 else
984 {
985 if (v >= version_map->size())
986 {
987 dynobj->error(_("versym for symbol %zu out of range: %u"),
988 i, v);
989 continue;
990 }
991
992 const char* version = (*version_map)[v];
993 if (version == NULL)
994 {
995 dynobj->error(_("versym for symbol %zu has no name: %u"),
996 i, v);
997 continue;
998 }
999
1000 Stringpool::Key version_key;
1001 version = this->namepool_.add(version, true, &version_key);
1002
1003 // If this is an absolute symbol, and the version name
1004 // and symbol name are the same, then this is the
1005 // version definition symbol. These symbols exist to
1006 // support using -u to pull in particular versions. We
1007 // do not want to record a version for them.
1008 if (sym.get_st_shndx() == elfcpp::SHN_ABS
1009 && name_key == version_key)
1010 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1011 false, sym, sym);
1012 else
1013 {
1014 const bool def = (!hidden
1015 && (sym.get_st_shndx()
1016 != elfcpp::SHN_UNDEF));
1017 res = this->add_from_object(dynobj, name, name_key, version,
1018 version_key, def, sym, sym);
1019 }
1020 }
1021 }
1022
1023 // Note that it is possible that RES was overridden by an
1024 // earlier object, in which case it can't be aliased here.
1025 if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
1026 && sym.get_st_type() == elfcpp::STT_OBJECT
1027 && res->source() == Symbol::FROM_OBJECT
1028 && res->object() == dynobj)
1029 object_symbols.push_back(res);
1030 }
1031
1032 this->record_weak_aliases(&object_symbols);
1033 }
1034
1035 // This is used to sort weak aliases. We sort them first by section
1036 // index, then by offset, then by weak ahead of strong.
1037
1038 template<int size>
1039 class Weak_alias_sorter
1040 {
1041 public:
1042 bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1043 };
1044
1045 template<int size>
1046 bool
1047 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1048 const Sized_symbol<size>* s2) const
1049 {
1050 if (s1->shndx() != s2->shndx())
1051 return s1->shndx() < s2->shndx();
1052 if (s1->value() != s2->value())
1053 return s1->value() < s2->value();
1054 if (s1->binding() != s2->binding())
1055 {
1056 if (s1->binding() == elfcpp::STB_WEAK)
1057 return true;
1058 if (s2->binding() == elfcpp::STB_WEAK)
1059 return false;
1060 }
1061 return std::string(s1->name()) < std::string(s2->name());
1062 }
1063
1064 // SYMBOLS is a list of object symbols from a dynamic object. Look
1065 // for any weak aliases, and record them so that if we add the weak
1066 // alias to the dynamic symbol table, we also add the corresponding
1067 // strong symbol.
1068
1069 template<int size>
1070 void
1071 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1072 {
1073 // Sort the vector by section index, then by offset, then by weak
1074 // ahead of strong.
1075 std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1076
1077 // Walk through the vector. For each weak definition, record
1078 // aliases.
1079 for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1080 symbols->begin();
1081 p != symbols->end();
1082 ++p)
1083 {
1084 if ((*p)->binding() != elfcpp::STB_WEAK)
1085 continue;
1086
1087 // Build a circular list of weak aliases. Each symbol points to
1088 // the next one in the circular list.
1089
1090 Sized_symbol<size>* from_sym = *p;
1091 typename std::vector<Sized_symbol<size>*>::const_iterator q;
1092 for (q = p + 1; q != symbols->end(); ++q)
1093 {
1094 if ((*q)->shndx() != from_sym->shndx()
1095 || (*q)->value() != from_sym->value())
1096 break;
1097
1098 this->weak_aliases_[from_sym] = *q;
1099 from_sym->set_has_alias();
1100 from_sym = *q;
1101 }
1102
1103 if (from_sym != *p)
1104 {
1105 this->weak_aliases_[from_sym] = *p;
1106 from_sym->set_has_alias();
1107 }
1108
1109 p = q - 1;
1110 }
1111 }
1112
1113 // Create and return a specially defined symbol. If ONLY_IF_REF is
1114 // true, then only create the symbol if there is a reference to it.
1115 // If this does not return NULL, it sets *POLDSYM to the existing
1116 // symbol if there is one. This canonicalizes *PNAME and *PVERSION.
1117
1118 template<int size, bool big_endian>
1119 Sized_symbol<size>*
1120 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1121 bool only_if_ref,
1122 Sized_symbol<size>** poldsym)
1123 {
1124 Symbol* oldsym;
1125 Sized_symbol<size>* sym;
1126 bool add_to_table = false;
1127 typename Symbol_table_type::iterator add_loc = this->table_.end();
1128
1129 // If the caller didn't give us a version, see if we get one from
1130 // the version script.
1131 if (*pversion == NULL)
1132 {
1133 const std::string& v(this->version_script_.get_symbol_version(*pname));
1134 if (!v.empty())
1135 *pversion = v.c_str();
1136 }
1137
1138 if (only_if_ref)
1139 {
1140 oldsym = this->lookup(*pname, *pversion);
1141 if (oldsym == NULL || !oldsym->is_undefined())
1142 return NULL;
1143
1144 *pname = oldsym->name();
1145 *pversion = oldsym->version();
1146 }
1147 else
1148 {
1149 // Canonicalize NAME and VERSION.
1150 Stringpool::Key name_key;
1151 *pname = this->namepool_.add(*pname, true, &name_key);
1152
1153 Stringpool::Key version_key = 0;
1154 if (*pversion != NULL)
1155 *pversion = this->namepool_.add(*pversion, true, &version_key);
1156
1157 Symbol* const snull = NULL;
1158 std::pair<typename Symbol_table_type::iterator, bool> ins =
1159 this->table_.insert(std::make_pair(std::make_pair(name_key,
1160 version_key),
1161 snull));
1162
1163 if (!ins.second)
1164 {
1165 // We already have a symbol table entry for NAME/VERSION.
1166 oldsym = ins.first->second;
1167 gold_assert(oldsym != NULL);
1168 }
1169 else
1170 {
1171 // We haven't seen this symbol before.
1172 gold_assert(ins.first->second == NULL);
1173 add_to_table = true;
1174 add_loc = ins.first;
1175 oldsym = NULL;
1176 }
1177 }
1178
1179 const Target& target = parameters->target();
1180 if (!target.has_make_symbol())
1181 sym = new Sized_symbol<size>();
1182 else
1183 {
1184 gold_assert(target.get_size() == size);
1185 gold_assert(target.is_big_endian() ? big_endian : !big_endian);
1186 typedef Sized_target<size, big_endian> My_target;
1187 const My_target* sized_target =
1188 static_cast<const My_target*>(&target);
1189 sym = sized_target->make_symbol();
1190 if (sym == NULL)
1191 return NULL;
1192 }
1193
1194 if (add_to_table)
1195 add_loc->second = sym;
1196 else
1197 gold_assert(oldsym != NULL);
1198
1199 *poldsym = this->get_sized_symbol<size>(oldsym);
1200
1201 return sym;
1202 }
1203
1204 // Define a symbol based on an Output_data.
1205
1206 Symbol*
1207 Symbol_table::define_in_output_data(const char* name,
1208 const char* version,
1209 Output_data* od,
1210 uint64_t value,
1211 uint64_t symsize,
1212 elfcpp::STT type,
1213 elfcpp::STB binding,
1214 elfcpp::STV visibility,
1215 unsigned char nonvis,
1216 bool offset_is_from_end,
1217 bool only_if_ref)
1218 {
1219 if (parameters->target().get_size() == 32)
1220 {
1221 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1222 return this->do_define_in_output_data<32>(name, version, od,
1223 value, symsize, type, binding,
1224 visibility, nonvis,
1225 offset_is_from_end,
1226 only_if_ref);
1227 #else
1228 gold_unreachable();
1229 #endif
1230 }
1231 else if (parameters->target().get_size() == 64)
1232 {
1233 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1234 return this->do_define_in_output_data<64>(name, version, od,
1235 value, symsize, type, binding,
1236 visibility, nonvis,
1237 offset_is_from_end,
1238 only_if_ref);
1239 #else
1240 gold_unreachable();
1241 #endif
1242 }
1243 else
1244 gold_unreachable();
1245 }
1246
1247 // Define a symbol in an Output_data, sized version.
1248
1249 template<int size>
1250 Sized_symbol<size>*
1251 Symbol_table::do_define_in_output_data(
1252 const char* name,
1253 const char* version,
1254 Output_data* od,
1255 typename elfcpp::Elf_types<size>::Elf_Addr value,
1256 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1257 elfcpp::STT type,
1258 elfcpp::STB binding,
1259 elfcpp::STV visibility,
1260 unsigned char nonvis,
1261 bool offset_is_from_end,
1262 bool only_if_ref)
1263 {
1264 Sized_symbol<size>* sym;
1265 Sized_symbol<size>* oldsym;
1266
1267 if (parameters->target().is_big_endian())
1268 {
1269 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1270 sym = this->define_special_symbol<size, true>(&name, &version,
1271 only_if_ref, &oldsym);
1272 #else
1273 gold_unreachable();
1274 #endif
1275 }
1276 else
1277 {
1278 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1279 sym = this->define_special_symbol<size, false>(&name, &version,
1280 only_if_ref, &oldsym);
1281 #else
1282 gold_unreachable();
1283 #endif
1284 }
1285
1286 if (sym == NULL)
1287 return NULL;
1288
1289 gold_assert(version == NULL || oldsym != NULL);
1290 sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1291 offset_is_from_end);
1292
1293 if (oldsym == NULL)
1294 {
1295 if (binding == elfcpp::STB_LOCAL
1296 || this->version_script_.symbol_is_local(name))
1297 this->force_local(sym);
1298 return sym;
1299 }
1300
1301 if (Symbol_table::should_override_with_special(oldsym))
1302 this->override_with_special(oldsym, sym);
1303 delete sym;
1304 return oldsym;
1305 }
1306
1307 // Define a symbol based on an Output_segment.
1308
1309 Symbol*
1310 Symbol_table::define_in_output_segment(const char* name,
1311 const char* version, Output_segment* os,
1312 uint64_t value,
1313 uint64_t symsize,
1314 elfcpp::STT type,
1315 elfcpp::STB binding,
1316 elfcpp::STV visibility,
1317 unsigned char nonvis,
1318 Symbol::Segment_offset_base offset_base,
1319 bool only_if_ref)
1320 {
1321 if (parameters->target().get_size() == 32)
1322 {
1323 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1324 return this->do_define_in_output_segment<32>(name, version, os,
1325 value, symsize, type,
1326 binding, visibility, nonvis,
1327 offset_base, only_if_ref);
1328 #else
1329 gold_unreachable();
1330 #endif
1331 }
1332 else if (parameters->target().get_size() == 64)
1333 {
1334 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1335 return this->do_define_in_output_segment<64>(name, version, os,
1336 value, symsize, type,
1337 binding, visibility, nonvis,
1338 offset_base, only_if_ref);
1339 #else
1340 gold_unreachable();
1341 #endif
1342 }
1343 else
1344 gold_unreachable();
1345 }
1346
1347 // Define a symbol in an Output_segment, sized version.
1348
1349 template<int size>
1350 Sized_symbol<size>*
1351 Symbol_table::do_define_in_output_segment(
1352 const char* name,
1353 const char* version,
1354 Output_segment* os,
1355 typename elfcpp::Elf_types<size>::Elf_Addr value,
1356 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1357 elfcpp::STT type,
1358 elfcpp::STB binding,
1359 elfcpp::STV visibility,
1360 unsigned char nonvis,
1361 Symbol::Segment_offset_base offset_base,
1362 bool only_if_ref)
1363 {
1364 Sized_symbol<size>* sym;
1365 Sized_symbol<size>* oldsym;
1366
1367 if (parameters->target().is_big_endian())
1368 {
1369 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1370 sym = this->define_special_symbol<size, true>(&name, &version,
1371 only_if_ref, &oldsym);
1372 #else
1373 gold_unreachable();
1374 #endif
1375 }
1376 else
1377 {
1378 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1379 sym = this->define_special_symbol<size, false>(&name, &version,
1380 only_if_ref, &oldsym);
1381 #else
1382 gold_unreachable();
1383 #endif
1384 }
1385
1386 if (sym == NULL)
1387 return NULL;
1388
1389 gold_assert(version == NULL || oldsym != NULL);
1390 sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1391 offset_base);
1392
1393 if (oldsym == NULL)
1394 {
1395 if (binding == elfcpp::STB_LOCAL
1396 || this->version_script_.symbol_is_local(name))
1397 this->force_local(sym);
1398 return sym;
1399 }
1400
1401 if (Symbol_table::should_override_with_special(oldsym))
1402 this->override_with_special(oldsym, sym);
1403 delete sym;
1404 return oldsym;
1405 }
1406
1407 // Define a special symbol with a constant value. It is a multiple
1408 // definition error if this symbol is already defined.
1409
1410 Symbol*
1411 Symbol_table::define_as_constant(const char* name,
1412 const char* version,
1413 uint64_t value,
1414 uint64_t symsize,
1415 elfcpp::STT type,
1416 elfcpp::STB binding,
1417 elfcpp::STV visibility,
1418 unsigned char nonvis,
1419 bool only_if_ref,
1420 bool force_override)
1421 {
1422 if (parameters->target().get_size() == 32)
1423 {
1424 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1425 return this->do_define_as_constant<32>(name, version, value,
1426 symsize, type, binding,
1427 visibility, nonvis, only_if_ref,
1428 force_override);
1429 #else
1430 gold_unreachable();
1431 #endif
1432 }
1433 else if (parameters->target().get_size() == 64)
1434 {
1435 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1436 return this->do_define_as_constant<64>(name, version, value,
1437 symsize, type, binding,
1438 visibility, nonvis, only_if_ref,
1439 force_override);
1440 #else
1441 gold_unreachable();
1442 #endif
1443 }
1444 else
1445 gold_unreachable();
1446 }
1447
1448 // Define a symbol as a constant, sized version.
1449
1450 template<int size>
1451 Sized_symbol<size>*
1452 Symbol_table::do_define_as_constant(
1453 const char* name,
1454 const char* version,
1455 typename elfcpp::Elf_types<size>::Elf_Addr value,
1456 typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1457 elfcpp::STT type,
1458 elfcpp::STB binding,
1459 elfcpp::STV visibility,
1460 unsigned char nonvis,
1461 bool only_if_ref,
1462 bool force_override)
1463 {
1464 Sized_symbol<size>* sym;
1465 Sized_symbol<size>* oldsym;
1466
1467 if (parameters->target().is_big_endian())
1468 {
1469 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1470 sym = this->define_special_symbol<size, true>(&name, &version,
1471 only_if_ref, &oldsym);
1472 #else
1473 gold_unreachable();
1474 #endif
1475 }
1476 else
1477 {
1478 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1479 sym = this->define_special_symbol<size, false>(&name, &version,
1480 only_if_ref, &oldsym);
1481 #else
1482 gold_unreachable();
1483 #endif
1484 }
1485
1486 if (sym == NULL)
1487 return NULL;
1488
1489 gold_assert(version == NULL || version == name || oldsym != NULL);
1490 sym->init(name, value, symsize, type, binding, visibility, nonvis);
1491
1492 if (oldsym == NULL)
1493 {
1494 // Version symbols are absolute symbols with name == version.
1495 // We don't want to force them to be local.
1496 if ((version == NULL
1497 || name != version
1498 || value != 0)
1499 && (binding == elfcpp::STB_LOCAL
1500 || this->version_script_.symbol_is_local(name)))
1501 this->force_local(sym);
1502 return sym;
1503 }
1504
1505 if (force_override || Symbol_table::should_override_with_special(oldsym))
1506 this->override_with_special(oldsym, sym);
1507 delete sym;
1508 return oldsym;
1509 }
1510
1511 // Define a set of symbols in output sections.
1512
1513 void
1514 Symbol_table::define_symbols(const Layout* layout, int count,
1515 const Define_symbol_in_section* p,
1516 bool only_if_ref)
1517 {
1518 for (int i = 0; i < count; ++i, ++p)
1519 {
1520 Output_section* os = layout->find_output_section(p->output_section);
1521 if (os != NULL)
1522 this->define_in_output_data(p->name, NULL, os, p->value,
1523 p->size, p->type, p->binding,
1524 p->visibility, p->nonvis,
1525 p->offset_is_from_end,
1526 only_if_ref || p->only_if_ref);
1527 else
1528 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1529 p->binding, p->visibility, p->nonvis,
1530 only_if_ref || p->only_if_ref,
1531 false);
1532 }
1533 }
1534
1535 // Define a set of symbols in output segments.
1536
1537 void
1538 Symbol_table::define_symbols(const Layout* layout, int count,
1539 const Define_symbol_in_segment* p,
1540 bool only_if_ref)
1541 {
1542 for (int i = 0; i < count; ++i, ++p)
1543 {
1544 Output_segment* os = layout->find_output_segment(p->segment_type,
1545 p->segment_flags_set,
1546 p->segment_flags_clear);
1547 if (os != NULL)
1548 this->define_in_output_segment(p->name, NULL, os, p->value,
1549 p->size, p->type, p->binding,
1550 p->visibility, p->nonvis,
1551 p->offset_base,
1552 only_if_ref || p->only_if_ref);
1553 else
1554 this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1555 p->binding, p->visibility, p->nonvis,
1556 only_if_ref || p->only_if_ref,
1557 false);
1558 }
1559 }
1560
1561 // Define CSYM using a COPY reloc. POSD is the Output_data where the
1562 // symbol should be defined--typically a .dyn.bss section. VALUE is
1563 // the offset within POSD.
1564
1565 template<int size>
1566 void
1567 Symbol_table::define_with_copy_reloc(
1568 Sized_symbol<size>* csym,
1569 Output_data* posd,
1570 typename elfcpp::Elf_types<size>::Elf_Addr value)
1571 {
1572 gold_assert(csym->is_from_dynobj());
1573 gold_assert(!csym->is_copied_from_dynobj());
1574 Object* object = csym->object();
1575 gold_assert(object->is_dynamic());
1576 Dynobj* dynobj = static_cast<Dynobj*>(object);
1577
1578 // Our copied variable has to override any variable in a shared
1579 // library.
1580 elfcpp::STB binding = csym->binding();
1581 if (binding == elfcpp::STB_WEAK)
1582 binding = elfcpp::STB_GLOBAL;
1583
1584 this->define_in_output_data(csym->name(), csym->version(),
1585 posd, value, csym->symsize(),
1586 csym->type(), binding,
1587 csym->visibility(), csym->nonvis(),
1588 false, false);
1589
1590 csym->set_is_copied_from_dynobj();
1591 csym->set_needs_dynsym_entry();
1592
1593 this->copied_symbol_dynobjs_[csym] = dynobj;
1594
1595 // We have now defined all aliases, but we have not entered them all
1596 // in the copied_symbol_dynobjs_ map.
1597 if (csym->has_alias())
1598 {
1599 Symbol* sym = csym;
1600 while (true)
1601 {
1602 sym = this->weak_aliases_[sym];
1603 if (sym == csym)
1604 break;
1605 gold_assert(sym->output_data() == posd);
1606
1607 sym->set_is_copied_from_dynobj();
1608 this->copied_symbol_dynobjs_[sym] = dynobj;
1609 }
1610 }
1611 }
1612
1613 // SYM is defined using a COPY reloc. Return the dynamic object where
1614 // the original definition was found.
1615
1616 Dynobj*
1617 Symbol_table::get_copy_source(const Symbol* sym) const
1618 {
1619 gold_assert(sym->is_copied_from_dynobj());
1620 Copied_symbol_dynobjs::const_iterator p =
1621 this->copied_symbol_dynobjs_.find(sym);
1622 gold_assert(p != this->copied_symbol_dynobjs_.end());
1623 return p->second;
1624 }
1625
1626 // Set the dynamic symbol indexes. INDEX is the index of the first
1627 // global dynamic symbol. Pointers to the symbols are stored into the
1628 // vector SYMS. The names are added to DYNPOOL. This returns an
1629 // updated dynamic symbol index.
1630
1631 unsigned int
1632 Symbol_table::set_dynsym_indexes(unsigned int index,
1633 std::vector<Symbol*>* syms,
1634 Stringpool* dynpool,
1635 Versions* versions)
1636 {
1637 for (Symbol_table_type::iterator p = this->table_.begin();
1638 p != this->table_.end();
1639 ++p)
1640 {
1641 Symbol* sym = p->second;
1642
1643 // Note that SYM may already have a dynamic symbol index, since
1644 // some symbols appear more than once in the symbol table, with
1645 // and without a version.
1646
1647 if (!sym->should_add_dynsym_entry())
1648 sym->set_dynsym_index(-1U);
1649 else if (!sym->has_dynsym_index())
1650 {
1651 sym->set_dynsym_index(index);
1652 ++index;
1653 syms->push_back(sym);
1654 dynpool->add(sym->name(), false, NULL);
1655
1656 // Record any version information.
1657 if (sym->version() != NULL)
1658 versions->record_version(this, dynpool, sym);
1659 }
1660 }
1661
1662 // Finish up the versions. In some cases this may add new dynamic
1663 // symbols.
1664 index = versions->finalize(this, index, syms);
1665
1666 return index;
1667 }
1668
1669 // Set the final values for all the symbols. The index of the first
1670 // global symbol in the output file is *PLOCAL_SYMCOUNT. Record the
1671 // file offset OFF. Add their names to POOL. Return the new file
1672 // offset. Update *PLOCAL_SYMCOUNT if necessary.
1673
1674 off_t
1675 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
1676 size_t dyncount, Stringpool* pool,
1677 unsigned int *plocal_symcount)
1678 {
1679 off_t ret;
1680
1681 gold_assert(*plocal_symcount != 0);
1682 this->first_global_index_ = *plocal_symcount;
1683
1684 this->dynamic_offset_ = dynoff;
1685 this->first_dynamic_global_index_ = dyn_global_index;
1686 this->dynamic_count_ = dyncount;
1687
1688 if (parameters->target().get_size() == 32)
1689 {
1690 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1691 ret = this->sized_finalize<32>(off, pool, plocal_symcount);
1692 #else
1693 gold_unreachable();
1694 #endif
1695 }
1696 else if (parameters->target().get_size() == 64)
1697 {
1698 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1699 ret = this->sized_finalize<64>(off, pool, plocal_symcount);
1700 #else
1701 gold_unreachable();
1702 #endif
1703 }
1704 else
1705 gold_unreachable();
1706
1707 // Now that we have the final symbol table, we can reliably note
1708 // which symbols should get warnings.
1709 this->warnings_.note_warnings(this);
1710
1711 return ret;
1712 }
1713
1714 // SYM is going into the symbol table at *PINDEX. Add the name to
1715 // POOL, update *PINDEX and *POFF.
1716
1717 template<int size>
1718 void
1719 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
1720 unsigned int* pindex, off_t* poff)
1721 {
1722 sym->set_symtab_index(*pindex);
1723 pool->add(sym->name(), false, NULL);
1724 ++*pindex;
1725 *poff += elfcpp::Elf_sizes<size>::sym_size;
1726 }
1727
1728 // Set the final value for all the symbols. This is called after
1729 // Layout::finalize, so all the output sections have their final
1730 // address.
1731
1732 template<int size>
1733 off_t
1734 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
1735 unsigned int* plocal_symcount)
1736 {
1737 off = align_address(off, size >> 3);
1738 this->offset_ = off;
1739
1740 unsigned int index = *plocal_symcount;
1741 const unsigned int orig_index = index;
1742
1743 // First do all the symbols which have been forced to be local, as
1744 // they must appear before all global symbols.
1745 for (Forced_locals::iterator p = this->forced_locals_.begin();
1746 p != this->forced_locals_.end();
1747 ++p)
1748 {
1749 Symbol* sym = *p;
1750 gold_assert(sym->is_forced_local());
1751 if (this->sized_finalize_symbol<size>(sym))
1752 {
1753 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1754 ++*plocal_symcount;
1755 }
1756 }
1757
1758 // Now do all the remaining symbols.
1759 for (Symbol_table_type::iterator p = this->table_.begin();
1760 p != this->table_.end();
1761 ++p)
1762 {
1763 Symbol* sym = p->second;
1764 if (this->sized_finalize_symbol<size>(sym))
1765 this->add_to_final_symtab<size>(sym, pool, &index, &off);
1766 }
1767
1768 this->output_count_ = index - orig_index;
1769
1770 return off;
1771 }
1772
1773 // Finalize the symbol SYM. This returns true if the symbol should be
1774 // added to the symbol table, false otherwise.
1775
1776 template<int size>
1777 bool
1778 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
1779 {
1780 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
1781
1782 // The default version of a symbol may appear twice in the symbol
1783 // table. We only need to finalize it once.
1784 if (sym->has_symtab_index())
1785 return false;
1786
1787 if (!sym->in_reg())
1788 {
1789 gold_assert(!sym->has_symtab_index());
1790 sym->set_symtab_index(-1U);
1791 gold_assert(sym->dynsym_index() == -1U);
1792 return false;
1793 }
1794
1795 typename Sized_symbol<size>::Value_type value;
1796
1797 switch (sym->source())
1798 {
1799 case Symbol::FROM_OBJECT:
1800 {
1801 unsigned int shndx = sym->shndx();
1802
1803 // FIXME: We need some target specific support here.
1804 if (shndx >= elfcpp::SHN_LORESERVE
1805 && shndx != elfcpp::SHN_ABS
1806 && shndx != elfcpp::SHN_COMMON)
1807 {
1808 gold_error(_("%s: unsupported symbol section 0x%x"),
1809 sym->demangled_name().c_str(), shndx);
1810 shndx = elfcpp::SHN_UNDEF;
1811 }
1812
1813 Object* symobj = sym->object();
1814 if (symobj->is_dynamic())
1815 {
1816 value = 0;
1817 shndx = elfcpp::SHN_UNDEF;
1818 }
1819 else if (shndx == elfcpp::SHN_UNDEF)
1820 value = 0;
1821 else if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
1822 value = sym->value();
1823 else
1824 {
1825 Relobj* relobj = static_cast<Relobj*>(symobj);
1826 section_offset_type secoff;
1827 Output_section* os = relobj->output_section(shndx, &secoff);
1828
1829 if (os == NULL)
1830 {
1831 sym->set_symtab_index(-1U);
1832 gold_assert(sym->dynsym_index() == -1U);
1833 return false;
1834 }
1835
1836 if (sym->type() == elfcpp::STT_TLS)
1837 value = sym->value() + os->tls_offset() + secoff;
1838 else
1839 value = sym->value() + os->address() + secoff;
1840 }
1841 }
1842 break;
1843
1844 case Symbol::IN_OUTPUT_DATA:
1845 {
1846 Output_data* od = sym->output_data();
1847 value = sym->value();
1848 if (sym->type() != elfcpp::STT_TLS)
1849 value += od->address();
1850 else
1851 {
1852 Output_section* os = od->output_section();
1853 gold_assert(os != NULL);
1854 value += os->tls_offset() + (od->address() - os->address());
1855 }
1856 if (sym->offset_is_from_end())
1857 value += od->data_size();
1858 }
1859 break;
1860
1861 case Symbol::IN_OUTPUT_SEGMENT:
1862 {
1863 Output_segment* os = sym->output_segment();
1864 value = sym->value();
1865 if (sym->type() != elfcpp::STT_TLS)
1866 value += os->vaddr();
1867 switch (sym->offset_base())
1868 {
1869 case Symbol::SEGMENT_START:
1870 break;
1871 case Symbol::SEGMENT_END:
1872 value += os->memsz();
1873 break;
1874 case Symbol::SEGMENT_BSS:
1875 value += os->filesz();
1876 break;
1877 default:
1878 gold_unreachable();
1879 }
1880 }
1881 break;
1882
1883 case Symbol::CONSTANT:
1884 value = sym->value();
1885 break;
1886
1887 default:
1888 gold_unreachable();
1889 }
1890
1891 sym->set_value(value);
1892
1893 if (parameters->options().strip_all())
1894 {
1895 sym->set_symtab_index(-1U);
1896 return false;
1897 }
1898
1899 return true;
1900 }
1901
1902 // Write out the global symbols.
1903
1904 void
1905 Symbol_table::write_globals(const Input_objects* input_objects,
1906 const Stringpool* sympool,
1907 const Stringpool* dynpool, Output_file* of) const
1908 {
1909 switch (parameters->size_and_endianness())
1910 {
1911 #ifdef HAVE_TARGET_32_LITTLE
1912 case Parameters::TARGET_32_LITTLE:
1913 this->sized_write_globals<32, false>(input_objects, sympool,
1914 dynpool, of);
1915 break;
1916 #endif
1917 #ifdef HAVE_TARGET_32_BIG
1918 case Parameters::TARGET_32_BIG:
1919 this->sized_write_globals<32, true>(input_objects, sympool,
1920 dynpool, of);
1921 break;
1922 #endif
1923 #ifdef HAVE_TARGET_64_LITTLE
1924 case Parameters::TARGET_64_LITTLE:
1925 this->sized_write_globals<64, false>(input_objects, sympool,
1926 dynpool, of);
1927 break;
1928 #endif
1929 #ifdef HAVE_TARGET_64_BIG
1930 case Parameters::TARGET_64_BIG:
1931 this->sized_write_globals<64, true>(input_objects, sympool,
1932 dynpool, of);
1933 break;
1934 #endif
1935 default:
1936 gold_unreachable();
1937 }
1938 }
1939
1940 // Write out the global symbols.
1941
1942 template<int size, bool big_endian>
1943 void
1944 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1945 const Stringpool* sympool,
1946 const Stringpool* dynpool,
1947 Output_file* of) const
1948 {
1949 const Target& target = parameters->target();
1950
1951 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1952
1953 const unsigned int output_count = this->output_count_;
1954 const section_size_type oview_size = output_count * sym_size;
1955 const unsigned int first_global_index = this->first_global_index_;
1956 unsigned char* psyms;
1957 if (this->offset_ == 0 || output_count == 0)
1958 psyms = NULL;
1959 else
1960 psyms = of->get_output_view(this->offset_, oview_size);
1961
1962 const unsigned int dynamic_count = this->dynamic_count_;
1963 const section_size_type dynamic_size = dynamic_count * sym_size;
1964 const unsigned int first_dynamic_global_index =
1965 this->first_dynamic_global_index_;
1966 unsigned char* dynamic_view;
1967 if (this->dynamic_offset_ == 0 || dynamic_count == 0)
1968 dynamic_view = NULL;
1969 else
1970 dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1971
1972 for (Symbol_table_type::const_iterator p = this->table_.begin();
1973 p != this->table_.end();
1974 ++p)
1975 {
1976 Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1977
1978 // Possibly warn about unresolved symbols in shared libraries.
1979 this->warn_about_undefined_dynobj_symbol(input_objects, sym);
1980
1981 unsigned int sym_index = sym->symtab_index();
1982 unsigned int dynsym_index;
1983 if (dynamic_view == NULL)
1984 dynsym_index = -1U;
1985 else
1986 dynsym_index = sym->dynsym_index();
1987
1988 if (sym_index == -1U && dynsym_index == -1U)
1989 {
1990 // This symbol is not included in the output file.
1991 continue;
1992 }
1993
1994 unsigned int shndx;
1995 typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
1996 typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
1997 switch (sym->source())
1998 {
1999 case Symbol::FROM_OBJECT:
2000 {
2001 unsigned int in_shndx = sym->shndx();
2002
2003 // FIXME: We need some target specific support here.
2004 if (in_shndx >= elfcpp::SHN_LORESERVE
2005 && in_shndx != elfcpp::SHN_ABS
2006 && in_shndx != elfcpp::SHN_COMMON)
2007 {
2008 gold_error(_("%s: unsupported symbol section 0x%x"),
2009 sym->demangled_name().c_str(), in_shndx);
2010 shndx = in_shndx;
2011 }
2012 else
2013 {
2014 Object* symobj = sym->object();
2015 if (symobj->is_dynamic())
2016 {
2017 if (sym->needs_dynsym_value())
2018 dynsym_value = target.dynsym_value(sym);
2019 shndx = elfcpp::SHN_UNDEF;
2020 }
2021 else if (in_shndx == elfcpp::SHN_UNDEF
2022 || in_shndx == elfcpp::SHN_ABS
2023 || in_shndx == elfcpp::SHN_COMMON)
2024 shndx = in_shndx;
2025 else
2026 {
2027 Relobj* relobj = static_cast<Relobj*>(symobj);
2028 section_offset_type secoff;
2029 Output_section* os = relobj->output_section(in_shndx,
2030 &secoff);
2031 gold_assert(os != NULL);
2032 shndx = os->out_shndx();
2033
2034 // In object files symbol values are section
2035 // relative.
2036 if (parameters->options().relocatable())
2037 sym_value -= os->address();
2038 }
2039 }
2040 }
2041 break;
2042
2043 case Symbol::IN_OUTPUT_DATA:
2044 shndx = sym->output_data()->out_shndx();
2045 break;
2046
2047 case Symbol::IN_OUTPUT_SEGMENT:
2048 shndx = elfcpp::SHN_ABS;
2049 break;
2050
2051 case Symbol::CONSTANT:
2052 shndx = elfcpp::SHN_ABS;
2053 break;
2054
2055 default:
2056 gold_unreachable();
2057 }
2058
2059 if (sym_index != -1U)
2060 {
2061 sym_index -= first_global_index;
2062 gold_assert(sym_index < output_count);
2063 unsigned char* ps = psyms + (sym_index * sym_size);
2064 this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2065 sympool, ps);
2066 }
2067
2068 if (dynsym_index != -1U)
2069 {
2070 dynsym_index -= first_dynamic_global_index;
2071 gold_assert(dynsym_index < dynamic_count);
2072 unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2073 this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2074 dynpool, pd);
2075 }
2076 }
2077
2078 of->write_output_view(this->offset_, oview_size, psyms);
2079 if (dynamic_view != NULL)
2080 of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2081 }
2082
2083 // Write out the symbol SYM, in section SHNDX, to P. POOL is the
2084 // strtab holding the name.
2085
2086 template<int size, bool big_endian>
2087 void
2088 Symbol_table::sized_write_symbol(
2089 Sized_symbol<size>* sym,
2090 typename elfcpp::Elf_types<size>::Elf_Addr value,
2091 unsigned int shndx,
2092 const Stringpool* pool,
2093 unsigned char* p) const
2094 {
2095 elfcpp::Sym_write<size, big_endian> osym(p);
2096 osym.put_st_name(pool->get_offset(sym->name()));
2097 osym.put_st_value(value);
2098 osym.put_st_size(sym->symsize());
2099 // A version script may have overridden the default binding.
2100 if (sym->is_forced_local())
2101 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2102 else
2103 osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2104 osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2105 osym.put_st_shndx(shndx);
2106 }
2107
2108 // Check for unresolved symbols in shared libraries. This is
2109 // controlled by the --allow-shlib-undefined option.
2110
2111 // We only warn about libraries for which we have seen all the
2112 // DT_NEEDED entries. We don't try to track down DT_NEEDED entries
2113 // which were not seen in this link. If we didn't see a DT_NEEDED
2114 // entry, we aren't going to be able to reliably report whether the
2115 // symbol is undefined.
2116
2117 // We also don't warn about libraries found in the system library
2118 // directory (the directory were we find libc.so); we assume that
2119 // those libraries are OK. This heuristic avoids problems in
2120 // GNU/Linux, in which -ldl can have undefined references satisfied by
2121 // ld-linux.so.
2122
2123 inline void
2124 Symbol_table::warn_about_undefined_dynobj_symbol(
2125 const Input_objects* input_objects,
2126 Symbol* sym) const
2127 {
2128 if (sym->source() == Symbol::FROM_OBJECT
2129 && sym->object()->is_dynamic()
2130 && sym->shndx() == elfcpp::SHN_UNDEF
2131 && sym->binding() != elfcpp::STB_WEAK
2132 && !parameters->options().allow_shlib_undefined()
2133 && !parameters->target().is_defined_by_abi(sym)
2134 && !input_objects->found_in_system_library_directory(sym->object()))
2135 {
2136 // A very ugly cast.
2137 Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2138 if (!dynobj->has_unknown_needed_entries())
2139 gold_error(_("%s: undefined reference to '%s'"),
2140 sym->object()->name().c_str(),
2141 sym->demangled_name().c_str());
2142 }
2143 }
2144
2145 // Write out a section symbol. Return the update offset.
2146
2147 void
2148 Symbol_table::write_section_symbol(const Output_section *os,
2149 Output_file* of,
2150 off_t offset) const
2151 {
2152 switch (parameters->size_and_endianness())
2153 {
2154 #ifdef HAVE_TARGET_32_LITTLE
2155 case Parameters::TARGET_32_LITTLE:
2156 this->sized_write_section_symbol<32, false>(os, of, offset);
2157 break;
2158 #endif
2159 #ifdef HAVE_TARGET_32_BIG
2160 case Parameters::TARGET_32_BIG:
2161 this->sized_write_section_symbol<32, true>(os, of, offset);
2162 break;
2163 #endif
2164 #ifdef HAVE_TARGET_64_LITTLE
2165 case Parameters::TARGET_64_LITTLE:
2166 this->sized_write_section_symbol<64, false>(os, of, offset);
2167 break;
2168 #endif
2169 #ifdef HAVE_TARGET_64_BIG
2170 case Parameters::TARGET_64_BIG:
2171 this->sized_write_section_symbol<64, true>(os, of, offset);
2172 break;
2173 #endif
2174 default:
2175 gold_unreachable();
2176 }
2177 }
2178
2179 // Write out a section symbol, specialized for size and endianness.
2180
2181 template<int size, bool big_endian>
2182 void
2183 Symbol_table::sized_write_section_symbol(const Output_section* os,
2184 Output_file* of,
2185 off_t offset) const
2186 {
2187 const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2188
2189 unsigned char* pov = of->get_output_view(offset, sym_size);
2190
2191 elfcpp::Sym_write<size, big_endian> osym(pov);
2192 osym.put_st_name(0);
2193 osym.put_st_value(os->address());
2194 osym.put_st_size(0);
2195 osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2196 elfcpp::STT_SECTION));
2197 osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2198 osym.put_st_shndx(os->out_shndx());
2199
2200 of->write_output_view(offset, sym_size, pov);
2201 }
2202
2203 // Print statistical information to stderr. This is used for --stats.
2204
2205 void
2206 Symbol_table::print_stats() const
2207 {
2208 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2209 fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2210 program_name, this->table_.size(), this->table_.bucket_count());
2211 #else
2212 fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2213 program_name, this->table_.size());
2214 #endif
2215 this->namepool_.print_stats("symbol table stringpool");
2216 }
2217
2218 // We check for ODR violations by looking for symbols with the same
2219 // name for which the debugging information reports that they were
2220 // defined in different source locations. When comparing the source
2221 // location, we consider instances with the same base filename and
2222 // line number to be the same. This is because different object
2223 // files/shared libraries can include the same header file using
2224 // different paths, and we don't want to report an ODR violation in
2225 // that case.
2226
2227 // This struct is used to compare line information, as returned by
2228 // Dwarf_line_info::one_addr2line. It implements a < comparison
2229 // operator used with std::set.
2230
2231 struct Odr_violation_compare
2232 {
2233 bool
2234 operator()(const std::string& s1, const std::string& s2) const
2235 {
2236 std::string::size_type pos1 = s1.rfind('/');
2237 std::string::size_type pos2 = s2.rfind('/');
2238 if (pos1 == std::string::npos
2239 || pos2 == std::string::npos)
2240 return s1 < s2;
2241 return s1.compare(pos1, std::string::npos,
2242 s2, pos2, std::string::npos) < 0;
2243 }
2244 };
2245
2246 // Check candidate_odr_violations_ to find symbols with the same name
2247 // but apparently different definitions (different source-file/line-no).
2248
2249 void
2250 Symbol_table::detect_odr_violations(const Task* task,
2251 const char* output_file_name) const
2252 {
2253 for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2254 it != candidate_odr_violations_.end();
2255 ++it)
2256 {
2257 const char* symbol_name = it->first;
2258 // We use a sorted set so the output is deterministic.
2259 std::set<std::string, Odr_violation_compare> line_nums;
2260
2261 for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2262 locs = it->second.begin();
2263 locs != it->second.end();
2264 ++locs)
2265 {
2266 // We need to lock the object in order to read it. This
2267 // means that we have to run in a singleton Task. If we
2268 // want to run this in a general Task for better
2269 // performance, we will need one Task for object, plus
2270 // appropriate locking to ensure that we don't conflict with
2271 // other uses of the object.
2272 Task_lock_obj<Object> tl(task, locs->object);
2273 std::string lineno = Dwarf_line_info::one_addr2line(
2274 locs->object, locs->shndx, locs->offset);
2275 if (!lineno.empty())
2276 line_nums.insert(lineno);
2277 }
2278
2279 if (line_nums.size() > 1)
2280 {
2281 gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2282 "places (possible ODR violation):"),
2283 output_file_name, demangle(symbol_name).c_str());
2284 for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2285 it2 != line_nums.end();
2286 ++it2)
2287 fprintf(stderr, " %s\n", it2->c_str());
2288 }
2289 }
2290 }
2291
2292 // Warnings functions.
2293
2294 // Add a new warning.
2295
2296 void
2297 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2298 const std::string& warning)
2299 {
2300 name = symtab->canonicalize_name(name);
2301 this->warnings_[name].set(obj, warning);
2302 }
2303
2304 // Look through the warnings and mark the symbols for which we should
2305 // warn. This is called during Layout::finalize when we know the
2306 // sources for all the symbols.
2307
2308 void
2309 Warnings::note_warnings(Symbol_table* symtab)
2310 {
2311 for (Warning_table::iterator p = this->warnings_.begin();
2312 p != this->warnings_.end();
2313 ++p)
2314 {
2315 Symbol* sym = symtab->lookup(p->first, NULL);
2316 if (sym != NULL
2317 && sym->source() == Symbol::FROM_OBJECT
2318 && sym->object() == p->second.object)
2319 sym->set_has_warning();
2320 }
2321 }
2322
2323 // Issue a warning. This is called when we see a relocation against a
2324 // symbol for which has a warning.
2325
2326 template<int size, bool big_endian>
2327 void
2328 Warnings::issue_warning(const Symbol* sym,
2329 const Relocate_info<size, big_endian>* relinfo,
2330 size_t relnum, off_t reloffset) const
2331 {
2332 gold_assert(sym->has_warning());
2333 Warning_table::const_iterator p = this->warnings_.find(sym->name());
2334 gold_assert(p != this->warnings_.end());
2335 gold_warning_at_location(relinfo, relnum, reloffset,
2336 "%s", p->second.text.c_str());
2337 }
2338
2339 // Instantiate the templates we need. We could use the configure
2340 // script to restrict this to only the ones needed for implemented
2341 // targets.
2342
2343 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2344 template
2345 void
2346 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2347 #endif
2348
2349 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2350 template
2351 void
2352 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2353 #endif
2354
2355 #ifdef HAVE_TARGET_32_LITTLE
2356 template
2357 void
2358 Symbol_table::add_from_relobj<32, false>(
2359 Sized_relobj<32, false>* relobj,
2360 const unsigned char* syms,
2361 size_t count,
2362 const char* sym_names,
2363 size_t sym_name_size,
2364 Sized_relobj<32, true>::Symbols* sympointers);
2365 #endif
2366
2367 #ifdef HAVE_TARGET_32_BIG
2368 template
2369 void
2370 Symbol_table::add_from_relobj<32, true>(
2371 Sized_relobj<32, true>* relobj,
2372 const unsigned char* syms,
2373 size_t count,
2374 const char* sym_names,
2375 size_t sym_name_size,
2376 Sized_relobj<32, false>::Symbols* sympointers);
2377 #endif
2378
2379 #ifdef HAVE_TARGET_64_LITTLE
2380 template
2381 void
2382 Symbol_table::add_from_relobj<64, false>(
2383 Sized_relobj<64, false>* relobj,
2384 const unsigned char* syms,
2385 size_t count,
2386 const char* sym_names,
2387 size_t sym_name_size,
2388 Sized_relobj<64, true>::Symbols* sympointers);
2389 #endif
2390
2391 #ifdef HAVE_TARGET_64_BIG
2392 template
2393 void
2394 Symbol_table::add_from_relobj<64, true>(
2395 Sized_relobj<64, true>* relobj,
2396 const unsigned char* syms,
2397 size_t count,
2398 const char* sym_names,
2399 size_t sym_name_size,
2400 Sized_relobj<64, false>::Symbols* sympointers);
2401 #endif
2402
2403 #ifdef HAVE_TARGET_32_LITTLE
2404 template
2405 void
2406 Symbol_table::add_from_dynobj<32, false>(
2407 Sized_dynobj<32, false>* dynobj,
2408 const unsigned char* syms,
2409 size_t count,
2410 const char* sym_names,
2411 size_t sym_name_size,
2412 const unsigned char* versym,
2413 size_t versym_size,
2414 const std::vector<const char*>* version_map);
2415 #endif
2416
2417 #ifdef HAVE_TARGET_32_BIG
2418 template
2419 void
2420 Symbol_table::add_from_dynobj<32, true>(
2421 Sized_dynobj<32, true>* dynobj,
2422 const unsigned char* syms,
2423 size_t count,
2424 const char* sym_names,
2425 size_t sym_name_size,
2426 const unsigned char* versym,
2427 size_t versym_size,
2428 const std::vector<const char*>* version_map);
2429 #endif
2430
2431 #ifdef HAVE_TARGET_64_LITTLE
2432 template
2433 void
2434 Symbol_table::add_from_dynobj<64, false>(
2435 Sized_dynobj<64, false>* dynobj,
2436 const unsigned char* syms,
2437 size_t count,
2438 const char* sym_names,
2439 size_t sym_name_size,
2440 const unsigned char* versym,
2441 size_t versym_size,
2442 const std::vector<const char*>* version_map);
2443 #endif
2444
2445 #ifdef HAVE_TARGET_64_BIG
2446 template
2447 void
2448 Symbol_table::add_from_dynobj<64, true>(
2449 Sized_dynobj<64, true>* dynobj,
2450 const unsigned char* syms,
2451 size_t count,
2452 const char* sym_names,
2453 size_t sym_name_size,
2454 const unsigned char* versym,
2455 size_t versym_size,
2456 const std::vector<const char*>* version_map);
2457 #endif
2458
2459 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2460 template
2461 void
2462 Symbol_table::define_with_copy_reloc<32>(
2463 Sized_symbol<32>* sym,
2464 Output_data* posd,
2465 elfcpp::Elf_types<32>::Elf_Addr value);
2466 #endif
2467
2468 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2469 template
2470 void
2471 Symbol_table::define_with_copy_reloc<64>(
2472 Sized_symbol<64>* sym,
2473 Output_data* posd,
2474 elfcpp::Elf_types<64>::Elf_Addr value);
2475 #endif
2476
2477 #ifdef HAVE_TARGET_32_LITTLE
2478 template
2479 void
2480 Warnings::issue_warning<32, false>(const Symbol* sym,
2481 const Relocate_info<32, false>* relinfo,
2482 size_t relnum, off_t reloffset) const;
2483 #endif
2484
2485 #ifdef HAVE_TARGET_32_BIG
2486 template
2487 void
2488 Warnings::issue_warning<32, true>(const Symbol* sym,
2489 const Relocate_info<32, true>* relinfo,
2490 size_t relnum, off_t reloffset) const;
2491 #endif
2492
2493 #ifdef HAVE_TARGET_64_LITTLE
2494 template
2495 void
2496 Warnings::issue_warning<64, false>(const Symbol* sym,
2497 const Relocate_info<64, false>* relinfo,
2498 size_t relnum, off_t reloffset) const;
2499 #endif
2500
2501 #ifdef HAVE_TARGET_64_BIG
2502 template
2503 void
2504 Warnings::issue_warning<64, true>(const Symbol* sym,
2505 const Relocate_info<64, true>* relinfo,
2506 size_t relnum, off_t reloffset) const;
2507 #endif
2508
2509 } // End namespace gold.