PR symtab/12302
[external/binutils.git] / gold / symtab.cc
1 // symtab.cc -- the gold symbol table
2
3 // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cstring>
26 #include <stdint.h>
27 #include <algorithm>
28 #include <set>
29 #include <string>
30 #include <utility>
31 #include "demangle.h"
32
33 #include "gc.h"
34 #include "object.h"
35 #include "dwarf_reader.h"
36 #include "dynobj.h"
37 #include "output.h"
38 #include "target.h"
39 #include "workqueue.h"
40 #include "symtab.h"
41 #include "script.h"
42 #include "plugin.h"
43
44 namespace gold
45 {
46
47 // Class Symbol.
48
49 // Initialize fields in Symbol.  This initializes everything except u_
50 // and source_.
51
52 void
53 Symbol::init_fields(const char* name, const char* version,
54                     elfcpp::STT type, elfcpp::STB binding,
55                     elfcpp::STV visibility, unsigned char nonvis)
56 {
57   this->name_ = name;
58   this->version_ = version;
59   this->symtab_index_ = 0;
60   this->dynsym_index_ = 0;
61   this->got_offsets_.init();
62   this->plt_offset_ = -1U;
63   this->type_ = type;
64   this->binding_ = binding;
65   this->visibility_ = visibility;
66   this->nonvis_ = nonvis;
67   this->is_def_ = false;
68   this->is_forwarder_ = false;
69   this->has_alias_ = false;
70   this->needs_dynsym_entry_ = false;
71   this->in_reg_ = false;
72   this->in_dyn_ = false;
73   this->has_warning_ = false;
74   this->is_copied_from_dynobj_ = false;
75   this->is_forced_local_ = false;
76   this->is_ordinary_shndx_ = false;
77   this->in_real_elf_ = false;
78   this->is_defined_in_discarded_section_ = false;
79   this->undef_binding_set_ = false;
80   this->undef_binding_weak_ = false;
81 }
82
83 // Return the demangled version of the symbol's name, but only
84 // if the --demangle flag was set.
85
86 static std::string
87 demangle(const char* name)
88 {
89   if (!parameters->options().do_demangle())
90     return name;
91
92   // cplus_demangle allocates memory for the result it returns,
93   // and returns NULL if the name is already demangled.
94   char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
95   if (demangled_name == NULL)
96     return name;
97
98   std::string retval(demangled_name);
99   free(demangled_name);
100   return retval;
101 }
102
103 std::string
104 Symbol::demangled_name() const
105 {
106   return demangle(this->name());
107 }
108
109 // Initialize the fields in the base class Symbol for SYM in OBJECT.
110
111 template<int size, bool big_endian>
112 void
113 Symbol::init_base_object(const char* name, const char* version, Object* object,
114                          const elfcpp::Sym<size, big_endian>& sym,
115                          unsigned int st_shndx, bool is_ordinary)
116 {
117   this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
118                     sym.get_st_visibility(), sym.get_st_nonvis());
119   this->u_.from_object.object = object;
120   this->u_.from_object.shndx = st_shndx;
121   this->is_ordinary_shndx_ = is_ordinary;
122   this->source_ = FROM_OBJECT;
123   this->in_reg_ = !object->is_dynamic();
124   this->in_dyn_ = object->is_dynamic();
125   this->in_real_elf_ = object->pluginobj() == NULL;
126 }
127
128 // Initialize the fields in the base class Symbol for a symbol defined
129 // in an Output_data.
130
131 void
132 Symbol::init_base_output_data(const char* name, const char* version,
133                               Output_data* od, elfcpp::STT type,
134                               elfcpp::STB binding, elfcpp::STV visibility,
135                               unsigned char nonvis, bool offset_is_from_end)
136 {
137   this->init_fields(name, version, type, binding, visibility, nonvis);
138   this->u_.in_output_data.output_data = od;
139   this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
140   this->source_ = IN_OUTPUT_DATA;
141   this->in_reg_ = true;
142   this->in_real_elf_ = true;
143 }
144
145 // Initialize the fields in the base class Symbol for a symbol defined
146 // in an Output_segment.
147
148 void
149 Symbol::init_base_output_segment(const char* name, const char* version,
150                                  Output_segment* os, elfcpp::STT type,
151                                  elfcpp::STB binding, elfcpp::STV visibility,
152                                  unsigned char nonvis,
153                                  Segment_offset_base offset_base)
154 {
155   this->init_fields(name, version, type, binding, visibility, nonvis);
156   this->u_.in_output_segment.output_segment = os;
157   this->u_.in_output_segment.offset_base = offset_base;
158   this->source_ = IN_OUTPUT_SEGMENT;
159   this->in_reg_ = true;
160   this->in_real_elf_ = true;
161 }
162
163 // Initialize the fields in the base class Symbol for a symbol defined
164 // as a constant.
165
166 void
167 Symbol::init_base_constant(const char* name, const char* version,
168                            elfcpp::STT type, elfcpp::STB binding,
169                            elfcpp::STV visibility, unsigned char nonvis)
170 {
171   this->init_fields(name, version, type, binding, visibility, nonvis);
172   this->source_ = IS_CONSTANT;
173   this->in_reg_ = true;
174   this->in_real_elf_ = true;
175 }
176
177 // Initialize the fields in the base class Symbol for an undefined
178 // symbol.
179
180 void
181 Symbol::init_base_undefined(const char* name, const char* version,
182                             elfcpp::STT type, elfcpp::STB binding,
183                             elfcpp::STV visibility, unsigned char nonvis)
184 {
185   this->init_fields(name, version, type, binding, visibility, nonvis);
186   this->dynsym_index_ = -1U;
187   this->source_ = IS_UNDEFINED;
188   this->in_reg_ = true;
189   this->in_real_elf_ = true;
190 }
191
192 // Allocate a common symbol in the base.
193
194 void
195 Symbol::allocate_base_common(Output_data* od)
196 {
197   gold_assert(this->is_common());
198   this->source_ = IN_OUTPUT_DATA;
199   this->u_.in_output_data.output_data = od;
200   this->u_.in_output_data.offset_is_from_end = false;
201 }
202
203 // Initialize the fields in Sized_symbol for SYM in OBJECT.
204
205 template<int size>
206 template<bool big_endian>
207 void
208 Sized_symbol<size>::init_object(const char* name, const char* version,
209                                 Object* object,
210                                 const elfcpp::Sym<size, big_endian>& sym,
211                                 unsigned int st_shndx, bool is_ordinary)
212 {
213   this->init_base_object(name, version, object, sym, st_shndx, is_ordinary);
214   this->value_ = sym.get_st_value();
215   this->symsize_ = sym.get_st_size();
216 }
217
218 // Initialize the fields in Sized_symbol for a symbol defined in an
219 // Output_data.
220
221 template<int size>
222 void
223 Sized_symbol<size>::init_output_data(const char* name, const char* version,
224                                      Output_data* od, Value_type value,
225                                      Size_type symsize, elfcpp::STT type,
226                                      elfcpp::STB binding,
227                                      elfcpp::STV visibility,
228                                      unsigned char nonvis,
229                                      bool offset_is_from_end)
230 {
231   this->init_base_output_data(name, version, od, type, binding, visibility,
232                               nonvis, offset_is_from_end);
233   this->value_ = value;
234   this->symsize_ = symsize;
235 }
236
237 // Initialize the fields in Sized_symbol for a symbol defined in an
238 // Output_segment.
239
240 template<int size>
241 void
242 Sized_symbol<size>::init_output_segment(const char* name, const char* version,
243                                         Output_segment* os, Value_type value,
244                                         Size_type symsize, elfcpp::STT type,
245                                         elfcpp::STB binding,
246                                         elfcpp::STV visibility,
247                                         unsigned char nonvis,
248                                         Segment_offset_base offset_base)
249 {
250   this->init_base_output_segment(name, version, os, type, binding, visibility,
251                                  nonvis, offset_base);
252   this->value_ = value;
253   this->symsize_ = symsize;
254 }
255
256 // Initialize the fields in Sized_symbol for a symbol defined as a
257 // constant.
258
259 template<int size>
260 void
261 Sized_symbol<size>::init_constant(const char* name, const char* version,
262                                   Value_type value, Size_type symsize,
263                                   elfcpp::STT type, elfcpp::STB binding,
264                                   elfcpp::STV visibility, unsigned char nonvis)
265 {
266   this->init_base_constant(name, version, type, binding, visibility, nonvis);
267   this->value_ = value;
268   this->symsize_ = symsize;
269 }
270
271 // Initialize the fields in Sized_symbol for an undefined symbol.
272
273 template<int size>
274 void
275 Sized_symbol<size>::init_undefined(const char* name, const char* version,
276                                    elfcpp::STT type, elfcpp::STB binding,
277                                    elfcpp::STV visibility, unsigned char nonvis)
278 {
279   this->init_base_undefined(name, version, type, binding, visibility, nonvis);
280   this->value_ = 0;
281   this->symsize_ = 0;
282 }
283
284 // Return true if SHNDX represents a common symbol.
285
286 bool
287 Symbol::is_common_shndx(unsigned int shndx)
288 {
289   return (shndx == elfcpp::SHN_COMMON
290           || shndx == parameters->target().small_common_shndx()
291           || shndx == parameters->target().large_common_shndx());
292 }
293
294 // Allocate a common symbol.
295
296 template<int size>
297 void
298 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
299 {
300   this->allocate_base_common(od);
301   this->value_ = value;
302 }
303
304 // The ""'s around str ensure str is a string literal, so sizeof works.
305 #define strprefix(var, str)   (strncmp(var, str, sizeof("" str "") - 1) == 0)
306
307 // Return true if this symbol should be added to the dynamic symbol
308 // table.
309
310 inline bool
311 Symbol::should_add_dynsym_entry(Symbol_table* symtab) const
312 {
313   // If the symbol is used by a dynamic relocation, we need to add it.
314   if (this->needs_dynsym_entry())
315     return true;
316
317   // If this symbol's section is not added, the symbol need not be added. 
318   // The section may have been GCed.  Note that export_dynamic is being 
319   // overridden here.  This should not be done for shared objects.
320   if (parameters->options().gc_sections() 
321       && !parameters->options().shared()
322       && this->source() == Symbol::FROM_OBJECT
323       && !this->object()->is_dynamic())
324     {
325       Relobj* relobj = static_cast<Relobj*>(this->object());
326       bool is_ordinary;
327       unsigned int shndx = this->shndx(&is_ordinary);
328       if (is_ordinary && shndx != elfcpp::SHN_UNDEF
329           && !relobj->is_section_included(shndx)
330           && !symtab->is_section_folded(relobj, shndx))
331         return false;
332     }
333
334   // If the symbol was forced local in a version script, do not add it.
335   if (this->is_forced_local())
336     return false;
337
338   // If the symbol was forced dynamic in a --dynamic-list file, add it.
339   if (parameters->options().in_dynamic_list(this->name()))
340     return true;
341
342   // If dynamic-list-data was specified, add any STT_OBJECT.
343   if (parameters->options().dynamic_list_data()
344       && !this->is_from_dynobj()
345       && this->type() == elfcpp::STT_OBJECT)
346     return true;
347
348   // If --dynamic-list-cpp-new was specified, add any new/delete symbol.
349   // If --dynamic-list-cpp-typeinfo was specified, add any typeinfo symbols.
350   if ((parameters->options().dynamic_list_cpp_new()
351        || parameters->options().dynamic_list_cpp_typeinfo())
352       && !this->is_from_dynobj())
353     {
354       // TODO(csilvers): We could probably figure out if we're an operator
355       //                 new/delete or typeinfo without the need to demangle.
356       char* demangled_name = cplus_demangle(this->name(),
357                                             DMGL_ANSI | DMGL_PARAMS);
358       if (demangled_name == NULL)
359         {
360           // Not a C++ symbol, so it can't satisfy these flags
361         }
362       else if (parameters->options().dynamic_list_cpp_new()
363                && (strprefix(demangled_name, "operator new")
364                    || strprefix(demangled_name, "operator delete")))
365         {
366           free(demangled_name);
367           return true;
368         }
369       else if (parameters->options().dynamic_list_cpp_typeinfo()
370                && (strprefix(demangled_name, "typeinfo name for")
371                    || strprefix(demangled_name, "typeinfo for")))
372         {
373           free(demangled_name);
374           return true;
375         }
376       else
377         free(demangled_name);
378     }
379
380   // If exporting all symbols or building a shared library,
381   // and the symbol is defined in a regular object and is
382   // externally visible, we need to add it.
383   if ((parameters->options().export_dynamic() || parameters->options().shared())
384       && !this->is_from_dynobj()
385       && this->is_externally_visible())
386     return true;
387
388   return false;
389 }
390
391 // Return true if the final value of this symbol is known at link
392 // time.
393
394 bool
395 Symbol::final_value_is_known() const
396 {
397   // If we are not generating an executable, then no final values are
398   // known, since they will change at runtime.
399   if (parameters->options().output_is_position_independent()
400       || parameters->options().relocatable())
401     return false;
402
403   // If the symbol is not from an object file, and is not undefined,
404   // then it is defined, and known.
405   if (this->source_ != FROM_OBJECT)
406     {
407       if (this->source_ != IS_UNDEFINED)
408         return true;
409     }
410   else
411     {
412       // If the symbol is from a dynamic object, then the final value
413       // is not known.
414       if (this->object()->is_dynamic())
415         return false;
416
417       // If the symbol is not undefined (it is defined or common),
418       // then the final value is known.
419       if (!this->is_undefined())
420         return true;
421     }
422
423   // If the symbol is undefined, then whether the final value is known
424   // depends on whether we are doing a static link.  If we are doing a
425   // dynamic link, then the final value could be filled in at runtime.
426   // This could reasonably be the case for a weak undefined symbol.
427   return parameters->doing_static_link();
428 }
429
430 // Return the output section where this symbol is defined.
431
432 Output_section*
433 Symbol::output_section() const
434 {
435   switch (this->source_)
436     {
437     case FROM_OBJECT:
438       {
439         unsigned int shndx = this->u_.from_object.shndx;
440         if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
441           {
442             gold_assert(!this->u_.from_object.object->is_dynamic());
443             gold_assert(this->u_.from_object.object->pluginobj() == NULL);
444             Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
445             return relobj->output_section(shndx);
446           }
447         return NULL;
448       }
449
450     case IN_OUTPUT_DATA:
451       return this->u_.in_output_data.output_data->output_section();
452
453     case IN_OUTPUT_SEGMENT:
454     case IS_CONSTANT:
455     case IS_UNDEFINED:
456       return NULL;
457
458     default:
459       gold_unreachable();
460     }
461 }
462
463 // Set the symbol's output section.  This is used for symbols defined
464 // in scripts.  This should only be called after the symbol table has
465 // been finalized.
466
467 void
468 Symbol::set_output_section(Output_section* os)
469 {
470   switch (this->source_)
471     {
472     case FROM_OBJECT:
473     case IN_OUTPUT_DATA:
474       gold_assert(this->output_section() == os);
475       break;
476     case IS_CONSTANT:
477       this->source_ = IN_OUTPUT_DATA;
478       this->u_.in_output_data.output_data = os;
479       this->u_.in_output_data.offset_is_from_end = false;
480       break;
481     case IN_OUTPUT_SEGMENT:
482     case IS_UNDEFINED:
483     default:
484       gold_unreachable();
485     }
486 }
487
488 // Class Symbol_table.
489
490 Symbol_table::Symbol_table(unsigned int count,
491                            const Version_script_info& version_script)
492   : saw_undefined_(0), offset_(0), table_(count), namepool_(),
493     forwarders_(), commons_(), tls_commons_(), small_commons_(),
494     large_commons_(), forced_locals_(), warnings_(),
495     version_script_(version_script), gc_(NULL), icf_(NULL)
496 {
497   namepool_.reserve(count);
498 }
499
500 Symbol_table::~Symbol_table()
501 {
502 }
503
504 // The symbol table key equality function.  This is called with
505 // Stringpool keys.
506
507 inline bool
508 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
509                                           const Symbol_table_key& k2) const
510 {
511   return k1.first == k2.first && k1.second == k2.second;
512 }
513
514 bool
515 Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
516 {
517   return (parameters->options().icf_enabled()
518           && this->icf_->is_section_folded(obj, shndx));
519 }
520
521 // For symbols that have been listed with -u option, add them to the
522 // work list to avoid gc'ing them.
523
524 void 
525 Symbol_table::gc_mark_undef_symbols(Layout* layout)
526 {
527   for (options::String_set::const_iterator p =
528          parameters->options().undefined_begin();
529        p != parameters->options().undefined_end();
530        ++p)
531     {
532       const char* name = p->c_str();
533       Symbol* sym = this->lookup(name);
534       gold_assert(sym != NULL);
535       if (sym->source() == Symbol::FROM_OBJECT 
536           && !sym->object()->is_dynamic())
537         {
538           Relobj* obj = static_cast<Relobj*>(sym->object());
539           bool is_ordinary;
540           unsigned int shndx = sym->shndx(&is_ordinary);
541           if (is_ordinary)
542             {
543               gold_assert(this->gc_ != NULL);
544               this->gc_->worklist().push(Section_id(obj, shndx));
545             }
546         }
547     }
548
549   for (Script_options::referenced_const_iterator p =
550          layout->script_options()->referenced_begin();
551        p != layout->script_options()->referenced_end();
552        ++p)
553     {
554       Symbol* sym = this->lookup(p->c_str());
555       gold_assert(sym != NULL);
556       if (sym->source() == Symbol::FROM_OBJECT
557           && !sym->object()->is_dynamic())
558         {
559           Relobj* obj = static_cast<Relobj*>(sym->object());
560           bool is_ordinary;
561           unsigned int shndx = sym->shndx(&is_ordinary);
562           if (is_ordinary)
563             {
564               gold_assert(this->gc_ != NULL);
565               this->gc_->worklist().push(Section_id(obj, shndx));
566             }
567         }
568     }
569 }
570
571 void
572 Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
573 {
574   if (!sym->is_from_dynobj() 
575       && sym->is_externally_visible())
576     {
577       //Add the object and section to the work list.
578       Relobj* obj = static_cast<Relobj*>(sym->object());
579       bool is_ordinary;
580       unsigned int shndx = sym->shndx(&is_ordinary);
581       if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
582         {
583           gold_assert(this->gc_!= NULL);
584           this->gc_->worklist().push(Section_id(obj, shndx));
585         }
586     }
587 }
588
589 // When doing garbage collection, keep symbols that have been seen in
590 // dynamic objects.
591 inline void 
592 Symbol_table::gc_mark_dyn_syms(Symbol* sym)
593 {
594   if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
595       && !sym->object()->is_dynamic())
596     {
597       Relobj* obj = static_cast<Relobj*>(sym->object()); 
598       bool is_ordinary;
599       unsigned int shndx = sym->shndx(&is_ordinary);
600       if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
601         {
602           gold_assert(this->gc_ != NULL);
603           this->gc_->worklist().push(Section_id(obj, shndx));
604         }
605     }
606 }
607
608 // Make TO a symbol which forwards to FROM.
609
610 void
611 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
612 {
613   gold_assert(from != to);
614   gold_assert(!from->is_forwarder() && !to->is_forwarder());
615   this->forwarders_[from] = to;
616   from->set_forwarder();
617 }
618
619 // Resolve the forwards from FROM, returning the real symbol.
620
621 Symbol*
622 Symbol_table::resolve_forwards(const Symbol* from) const
623 {
624   gold_assert(from->is_forwarder());
625   Unordered_map<const Symbol*, Symbol*>::const_iterator p =
626     this->forwarders_.find(from);
627   gold_assert(p != this->forwarders_.end());
628   return p->second;
629 }
630
631 // Look up a symbol by name.
632
633 Symbol*
634 Symbol_table::lookup(const char* name, const char* version) const
635 {
636   Stringpool::Key name_key;
637   name = this->namepool_.find(name, &name_key);
638   if (name == NULL)
639     return NULL;
640
641   Stringpool::Key version_key = 0;
642   if (version != NULL)
643     {
644       version = this->namepool_.find(version, &version_key);
645       if (version == NULL)
646         return NULL;
647     }
648
649   Symbol_table_key key(name_key, version_key);
650   Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
651   if (p == this->table_.end())
652     return NULL;
653   return p->second;
654 }
655
656 // Resolve a Symbol with another Symbol.  This is only used in the
657 // unusual case where there are references to both an unversioned
658 // symbol and a symbol with a version, and we then discover that that
659 // version is the default version.  Because this is unusual, we do
660 // this the slow way, by converting back to an ELF symbol.
661
662 template<int size, bool big_endian>
663 void
664 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from)
665 {
666   unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
667   elfcpp::Sym_write<size, big_endian> esym(buf);
668   // We don't bother to set the st_name or the st_shndx field.
669   esym.put_st_value(from->value());
670   esym.put_st_size(from->symsize());
671   esym.put_st_info(from->binding(), from->type());
672   esym.put_st_other(from->visibility(), from->nonvis());
673   bool is_ordinary;
674   unsigned int shndx = from->shndx(&is_ordinary);
675   this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
676                 from->version());
677   if (from->in_reg())
678     to->set_in_reg();
679   if (from->in_dyn())
680     to->set_in_dyn();
681   if (parameters->options().gc_sections())
682     this->gc_mark_dyn_syms(to);
683 }
684
685 // Record that a symbol is forced to be local by a version script or
686 // by visibility.
687
688 void
689 Symbol_table::force_local(Symbol* sym)
690 {
691   if (!sym->is_defined() && !sym->is_common())
692     return;
693   if (sym->is_forced_local())
694     {
695       // We already got this one.
696       return;
697     }
698   sym->set_is_forced_local();
699   this->forced_locals_.push_back(sym);
700 }
701
702 // Adjust NAME for wrapping, and update *NAME_KEY if necessary.  This
703 // is only called for undefined symbols, when at least one --wrap
704 // option was used.
705
706 const char*
707 Symbol_table::wrap_symbol(const char* name, Stringpool::Key* name_key)
708 {
709   // For some targets, we need to ignore a specific character when
710   // wrapping, and add it back later.
711   char prefix = '\0';
712   if (name[0] == parameters->target().wrap_char())
713     {
714       prefix = name[0];
715       ++name;
716     }
717
718   if (parameters->options().is_wrap(name))
719     {
720       // Turn NAME into __wrap_NAME.
721       std::string s;
722       if (prefix != '\0')
723         s += prefix;
724       s += "__wrap_";
725       s += name;
726
727       // This will give us both the old and new name in NAMEPOOL_, but
728       // that is OK.  Only the versions we need will wind up in the
729       // real string table in the output file.
730       return this->namepool_.add(s.c_str(), true, name_key);
731     }
732
733   const char* const real_prefix = "__real_";
734   const size_t real_prefix_length = strlen(real_prefix);
735   if (strncmp(name, real_prefix, real_prefix_length) == 0
736       && parameters->options().is_wrap(name + real_prefix_length))
737     {
738       // Turn __real_NAME into NAME.
739       std::string s;
740       if (prefix != '\0')
741         s += prefix;
742       s += name + real_prefix_length;
743       return this->namepool_.add(s.c_str(), true, name_key);
744     }
745
746   return name;
747 }
748
749 // This is called when we see a symbol NAME/VERSION, and the symbol
750 // already exists in the symbol table, and VERSION is marked as being
751 // the default version.  SYM is the NAME/VERSION symbol we just added.
752 // DEFAULT_IS_NEW is true if this is the first time we have seen the
753 // symbol NAME/NULL.  PDEF points to the entry for NAME/NULL.
754
755 template<int size, bool big_endian>
756 void
757 Symbol_table::define_default_version(Sized_symbol<size>* sym,
758                                      bool default_is_new,
759                                      Symbol_table_type::iterator pdef)
760 {
761   if (default_is_new)
762     {
763       // This is the first time we have seen NAME/NULL.  Make
764       // NAME/NULL point to NAME/VERSION, and mark SYM as the default
765       // version.
766       pdef->second = sym;
767       sym->set_is_default();
768     }
769   else if (pdef->second == sym)
770     {
771       // NAME/NULL already points to NAME/VERSION.  Don't mark the
772       // symbol as the default if it is not already the default.
773     }
774   else
775     {
776       // This is the unfortunate case where we already have entries
777       // for both NAME/VERSION and NAME/NULL.  We now see a symbol
778       // NAME/VERSION where VERSION is the default version.  We have
779       // already resolved this new symbol with the existing
780       // NAME/VERSION symbol.
781
782       // It's possible that NAME/NULL and NAME/VERSION are both
783       // defined in regular objects.  This can only happen if one
784       // object file defines foo and another defines foo@@ver.  This
785       // is somewhat obscure, but we call it a multiple definition
786       // error.
787
788       // It's possible that NAME/NULL actually has a version, in which
789       // case it won't be the same as VERSION.  This happens with
790       // ver_test_7.so in the testsuite for the symbol t2_2.  We see
791       // t2_2@@VER2, so we define both t2_2/VER2 and t2_2/NULL.  We
792       // then see an unadorned t2_2 in an object file and give it
793       // version VER1 from the version script.  This looks like a
794       // default definition for VER1, so it looks like we should merge
795       // t2_2/NULL with t2_2/VER1.  That doesn't make sense, but it's
796       // not obvious that this is an error, either.  So we just punt.
797
798       // If one of the symbols has non-default visibility, and the
799       // other is defined in a shared object, then they are different
800       // symbols.
801
802       // Otherwise, we just resolve the symbols as though they were
803       // the same.
804
805       if (pdef->second->version() != NULL)
806         gold_assert(pdef->second->version() != sym->version());
807       else if (sym->visibility() != elfcpp::STV_DEFAULT
808                && pdef->second->is_from_dynobj())
809         ;
810       else if (pdef->second->visibility() != elfcpp::STV_DEFAULT
811                && sym->is_from_dynobj())
812         ;
813       else
814         {
815           const Sized_symbol<size>* symdef;
816           symdef = this->get_sized_symbol<size>(pdef->second);
817           Symbol_table::resolve<size, big_endian>(sym, symdef);
818           this->make_forwarder(pdef->second, sym);
819           pdef->second = sym;
820           sym->set_is_default();
821         }
822     }
823 }
824
825 // Add one symbol from OBJECT to the symbol table.  NAME is symbol
826 // name and VERSION is the version; both are canonicalized.  DEF is
827 // whether this is the default version.  ST_SHNDX is the symbol's
828 // section index; IS_ORDINARY is whether this is a normal section
829 // rather than a special code.
830
831 // If IS_DEFAULT_VERSION is true, then this is the definition of a
832 // default version of a symbol.  That means that any lookup of
833 // NAME/NULL and any lookup of NAME/VERSION should always return the
834 // same symbol.  This is obvious for references, but in particular we
835 // want to do this for definitions: overriding NAME/NULL should also
836 // override NAME/VERSION.  If we don't do that, it would be very hard
837 // to override functions in a shared library which uses versioning.
838
839 // We implement this by simply making both entries in the hash table
840 // point to the same Symbol structure.  That is easy enough if this is
841 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
842 // that we have seen both already, in which case they will both have
843 // independent entries in the symbol table.  We can't simply change
844 // the symbol table entry, because we have pointers to the entries
845 // attached to the object files.  So we mark the entry attached to the
846 // object file as a forwarder, and record it in the forwarders_ map.
847 // Note that entries in the hash table will never be marked as
848 // forwarders.
849 //
850 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
851 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
852 // for a special section code.  ST_SHNDX may be modified if the symbol
853 // is defined in a section being discarded.
854
855 template<int size, bool big_endian>
856 Sized_symbol<size>*
857 Symbol_table::add_from_object(Object* object,
858                               const char* name,
859                               Stringpool::Key name_key,
860                               const char* version,
861                               Stringpool::Key version_key,
862                               bool is_default_version,
863                               const elfcpp::Sym<size, big_endian>& sym,
864                               unsigned int st_shndx,
865                               bool is_ordinary,
866                               unsigned int orig_st_shndx)
867 {
868   // Print a message if this symbol is being traced.
869   if (parameters->options().is_trace_symbol(name))
870     {
871       if (orig_st_shndx == elfcpp::SHN_UNDEF)
872         gold_info(_("%s: reference to %s"), object->name().c_str(), name);
873       else
874         gold_info(_("%s: definition of %s"), object->name().c_str(), name);
875     }
876
877   // For an undefined symbol, we may need to adjust the name using
878   // --wrap.
879   if (orig_st_shndx == elfcpp::SHN_UNDEF
880       && parameters->options().any_wrap())
881     {
882       const char* wrap_name = this->wrap_symbol(name, &name_key);
883       if (wrap_name != name)
884         {
885           // If we see a reference to malloc with version GLIBC_2.0,
886           // and we turn it into a reference to __wrap_malloc, then we
887           // discard the version number.  Otherwise the user would be
888           // required to specify the correct version for
889           // __wrap_malloc.
890           version = NULL;
891           version_key = 0;
892           name = wrap_name;
893         }
894     }
895
896   Symbol* const snull = NULL;
897   std::pair<typename Symbol_table_type::iterator, bool> ins =
898     this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
899                                        snull));
900
901   std::pair<typename Symbol_table_type::iterator, bool> insdefault =
902     std::make_pair(this->table_.end(), false);
903   if (is_default_version)
904     {
905       const Stringpool::Key vnull_key = 0;
906       insdefault = this->table_.insert(std::make_pair(std::make_pair(name_key,
907                                                                      vnull_key),
908                                                       snull));
909     }
910
911   // ins.first: an iterator, which is a pointer to a pair.
912   // ins.first->first: the key (a pair of name and version).
913   // ins.first->second: the value (Symbol*).
914   // ins.second: true if new entry was inserted, false if not.
915
916   Sized_symbol<size>* ret;
917   bool was_undefined;
918   bool was_common;
919   if (!ins.second)
920     {
921       // We already have an entry for NAME/VERSION.
922       ret = this->get_sized_symbol<size>(ins.first->second);
923       gold_assert(ret != NULL);
924
925       was_undefined = ret->is_undefined();
926       was_common = ret->is_common();
927
928       this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
929                     version);
930       if (parameters->options().gc_sections())
931         this->gc_mark_dyn_syms(ret);
932
933       if (is_default_version)
934         this->define_default_version<size, big_endian>(ret, insdefault.second,
935                                                        insdefault.first);
936     }
937   else
938     {
939       // This is the first time we have seen NAME/VERSION.
940       gold_assert(ins.first->second == NULL);
941
942       if (is_default_version && !insdefault.second)
943         {
944           // We already have an entry for NAME/NULL.  If we override
945           // it, then change it to NAME/VERSION.
946           ret = this->get_sized_symbol<size>(insdefault.first->second);
947
948           was_undefined = ret->is_undefined();
949           was_common = ret->is_common();
950
951           this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
952                         version);
953           if (parameters->options().gc_sections())
954             this->gc_mark_dyn_syms(ret);
955           ins.first->second = ret;
956         }
957       else
958         {
959           was_undefined = false;
960           was_common = false;
961
962           Sized_target<size, big_endian>* target =
963             parameters->sized_target<size, big_endian>();
964           if (!target->has_make_symbol())
965             ret = new Sized_symbol<size>();
966           else
967             {
968               ret = target->make_symbol();
969               if (ret == NULL)
970                 {
971                   // This means that we don't want a symbol table
972                   // entry after all.
973                   if (!is_default_version)
974                     this->table_.erase(ins.first);
975                   else
976                     {
977                       this->table_.erase(insdefault.first);
978                       // Inserting INSDEFAULT invalidated INS.
979                       this->table_.erase(std::make_pair(name_key,
980                                                         version_key));
981                     }
982                   return NULL;
983                 }
984             }
985
986           ret->init_object(name, version, object, sym, st_shndx, is_ordinary);
987
988           ins.first->second = ret;
989           if (is_default_version)
990             {
991               // This is the first time we have seen NAME/NULL.  Point
992               // it at the new entry for NAME/VERSION.
993               gold_assert(insdefault.second);
994               insdefault.first->second = ret;
995             }
996         }
997
998       if (is_default_version)
999         ret->set_is_default();
1000     }
1001
1002   // Record every time we see a new undefined symbol, to speed up
1003   // archive groups.
1004   if (!was_undefined && ret->is_undefined())
1005     ++this->saw_undefined_;
1006
1007   // Keep track of common symbols, to speed up common symbol
1008   // allocation.
1009   if (!was_common && ret->is_common())
1010     {
1011       if (ret->type() == elfcpp::STT_TLS)
1012         this->tls_commons_.push_back(ret);
1013       else if (!is_ordinary
1014                && st_shndx == parameters->target().small_common_shndx())
1015         this->small_commons_.push_back(ret);
1016       else if (!is_ordinary
1017                && st_shndx == parameters->target().large_common_shndx())
1018         this->large_commons_.push_back(ret);
1019       else
1020         this->commons_.push_back(ret);
1021     }
1022
1023   // If we're not doing a relocatable link, then any symbol with
1024   // hidden or internal visibility is local.
1025   if ((ret->visibility() == elfcpp::STV_HIDDEN
1026        || ret->visibility() == elfcpp::STV_INTERNAL)
1027       && (ret->binding() == elfcpp::STB_GLOBAL
1028           || ret->binding() == elfcpp::STB_GNU_UNIQUE
1029           || ret->binding() == elfcpp::STB_WEAK)
1030       && !parameters->options().relocatable())
1031     this->force_local(ret);
1032
1033   return ret;
1034 }
1035
1036 // Add all the symbols in a relocatable object to the hash table.
1037
1038 template<int size, bool big_endian>
1039 void
1040 Symbol_table::add_from_relobj(
1041     Sized_relobj<size, big_endian>* relobj,
1042     const unsigned char* syms,
1043     size_t count,
1044     size_t symndx_offset,
1045     const char* sym_names,
1046     size_t sym_name_size,
1047     typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1048     size_t* defined)
1049 {
1050   *defined = 0;
1051
1052   gold_assert(size == parameters->target().get_size());
1053
1054   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1055
1056   const bool just_symbols = relobj->just_symbols();
1057
1058   const unsigned char* p = syms;
1059   for (size_t i = 0; i < count; ++i, p += sym_size)
1060     {
1061       (*sympointers)[i] = NULL;
1062
1063       elfcpp::Sym<size, big_endian> sym(p);
1064
1065       unsigned int st_name = sym.get_st_name();
1066       if (st_name >= sym_name_size)
1067         {
1068           relobj->error(_("bad global symbol name offset %u at %zu"),
1069                         st_name, i);
1070           continue;
1071         }
1072
1073       const char* name = sym_names + st_name;
1074
1075       bool is_ordinary;
1076       unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
1077                                                        sym.get_st_shndx(),
1078                                                        &is_ordinary);
1079       unsigned int orig_st_shndx = st_shndx;
1080       if (!is_ordinary)
1081         orig_st_shndx = elfcpp::SHN_UNDEF;
1082
1083       if (st_shndx != elfcpp::SHN_UNDEF)
1084         ++*defined;
1085
1086       // A symbol defined in a section which we are not including must
1087       // be treated as an undefined symbol.
1088       bool is_defined_in_discarded_section = false;
1089       if (st_shndx != elfcpp::SHN_UNDEF
1090           && is_ordinary
1091           && !relobj->is_section_included(st_shndx)
1092           && !this->is_section_folded(relobj, st_shndx))
1093         {
1094           st_shndx = elfcpp::SHN_UNDEF;
1095           is_defined_in_discarded_section = true;
1096         }
1097
1098       // In an object file, an '@' in the name separates the symbol
1099       // name from the version name.  If there are two '@' characters,
1100       // this is the default version.
1101       const char* ver = strchr(name, '@');
1102       Stringpool::Key ver_key = 0;
1103       int namelen = 0;
1104       // IS_DEFAULT_VERSION: is the version default?
1105       // IS_FORCED_LOCAL: is the symbol forced local?
1106       bool is_default_version = false;
1107       bool is_forced_local = false;
1108
1109       if (ver != NULL)
1110         {
1111           // The symbol name is of the form foo@VERSION or foo@@VERSION
1112           namelen = ver - name;
1113           ++ver;
1114           if (*ver == '@')
1115             {
1116               is_default_version = true;
1117               ++ver;
1118             }
1119           ver = this->namepool_.add(ver, true, &ver_key);
1120         }
1121       // We don't want to assign a version to an undefined symbol,
1122       // even if it is listed in the version script.  FIXME: What
1123       // about a common symbol?
1124       else
1125         {
1126           namelen = strlen(name);
1127           if (!this->version_script_.empty()
1128               && st_shndx != elfcpp::SHN_UNDEF)
1129             {
1130               // The symbol name did not have a version, but the
1131               // version script may assign a version anyway.
1132               std::string version;
1133               bool is_global;
1134               if (this->version_script_.get_symbol_version(name, &version,
1135                                                            &is_global))
1136                 {
1137                   if (!is_global)
1138                     is_forced_local = true;
1139                   else if (!version.empty())
1140                     {
1141                       ver = this->namepool_.add_with_length(version.c_str(),
1142                                                             version.length(),
1143                                                             true,
1144                                                             &ver_key);
1145                       is_default_version = true;
1146                     }
1147                 }
1148             }
1149         }
1150
1151       elfcpp::Sym<size, big_endian>* psym = &sym;
1152       unsigned char symbuf[sym_size];
1153       elfcpp::Sym<size, big_endian> sym2(symbuf);
1154       if (just_symbols)
1155         {
1156           memcpy(symbuf, p, sym_size);
1157           elfcpp::Sym_write<size, big_endian> sw(symbuf);
1158           if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
1159             {
1160               // Symbol values in object files are section relative.
1161               // This is normally what we want, but since here we are
1162               // converting the symbol to absolute we need to add the
1163               // section address.  The section address in an object
1164               // file is normally zero, but people can use a linker
1165               // script to change it.
1166               sw.put_st_value(sym.get_st_value()
1167                               + relobj->section_address(orig_st_shndx));
1168             }
1169           st_shndx = elfcpp::SHN_ABS;
1170           is_ordinary = false;
1171           psym = &sym2;
1172         }
1173
1174       // Fix up visibility if object has no-export set.
1175       if (relobj->no_export()
1176           && (orig_st_shndx != elfcpp::SHN_UNDEF || !is_ordinary))
1177         {
1178           // We may have copied symbol already above.
1179           if (psym != &sym2)
1180             {
1181               memcpy(symbuf, p, sym_size);
1182               psym = &sym2;
1183             }
1184
1185           elfcpp::STV visibility = sym2.get_st_visibility();
1186           if (visibility == elfcpp::STV_DEFAULT
1187               || visibility == elfcpp::STV_PROTECTED)
1188             {
1189               elfcpp::Sym_write<size, big_endian> sw(symbuf);
1190               unsigned char nonvis = sym2.get_st_nonvis();
1191               sw.put_st_other(elfcpp::STV_HIDDEN, nonvis);
1192             }
1193         }
1194
1195       Stringpool::Key name_key;
1196       name = this->namepool_.add_with_length(name, namelen, true,
1197                                              &name_key);
1198
1199       Sized_symbol<size>* res;
1200       res = this->add_from_object(relobj, name, name_key, ver, ver_key,
1201                                   is_default_version, *psym, st_shndx,
1202                                   is_ordinary, orig_st_shndx);
1203       
1204       // If building a shared library using garbage collection, do not 
1205       // treat externally visible symbols as garbage.
1206       if (parameters->options().gc_sections() 
1207           && parameters->options().shared())
1208         this->gc_mark_symbol_for_shlib(res);
1209
1210       if (is_forced_local)
1211         this->force_local(res);
1212
1213       if (is_defined_in_discarded_section)
1214         res->set_is_defined_in_discarded_section();
1215
1216       (*sympointers)[i] = res;
1217     }
1218 }
1219
1220 // Add a symbol from a plugin-claimed file.
1221
1222 template<int size, bool big_endian>
1223 Symbol*
1224 Symbol_table::add_from_pluginobj(
1225     Sized_pluginobj<size, big_endian>* obj,
1226     const char* name,
1227     const char* ver,
1228     elfcpp::Sym<size, big_endian>* sym)
1229 {
1230   unsigned int st_shndx = sym->get_st_shndx();
1231   bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
1232
1233   Stringpool::Key ver_key = 0;
1234   bool is_default_version = false;
1235   bool is_forced_local = false;
1236
1237   if (ver != NULL)
1238     {
1239       ver = this->namepool_.add(ver, true, &ver_key);
1240     }
1241   // We don't want to assign a version to an undefined symbol,
1242   // even if it is listed in the version script.  FIXME: What
1243   // about a common symbol?
1244   else
1245     {
1246       if (!this->version_script_.empty()
1247           && st_shndx != elfcpp::SHN_UNDEF)
1248         {
1249           // The symbol name did not have a version, but the
1250           // version script may assign a version anyway.
1251           std::string version;
1252           bool is_global;
1253           if (this->version_script_.get_symbol_version(name, &version,
1254                                                        &is_global))
1255             {
1256               if (!is_global)
1257                 is_forced_local = true;
1258               else if (!version.empty())
1259                 {
1260                   ver = this->namepool_.add_with_length(version.c_str(),
1261                                                         version.length(),
1262                                                         true,
1263                                                         &ver_key);
1264                   is_default_version = true;
1265                 }
1266             }
1267         }
1268     }
1269
1270   Stringpool::Key name_key;
1271   name = this->namepool_.add(name, true, &name_key);
1272
1273   Sized_symbol<size>* res;
1274   res = this->add_from_object(obj, name, name_key, ver, ver_key,
1275                               is_default_version, *sym, st_shndx,
1276                               is_ordinary, st_shndx);
1277
1278   if (is_forced_local)
1279     this->force_local(res);
1280
1281   return res;
1282 }
1283
1284 // Add all the symbols in a dynamic object to the hash table.
1285
1286 template<int size, bool big_endian>
1287 void
1288 Symbol_table::add_from_dynobj(
1289     Sized_dynobj<size, big_endian>* dynobj,
1290     const unsigned char* syms,
1291     size_t count,
1292     const char* sym_names,
1293     size_t sym_name_size,
1294     const unsigned char* versym,
1295     size_t versym_size,
1296     const std::vector<const char*>* version_map,
1297     typename Sized_relobj<size, big_endian>::Symbols* sympointers,
1298     size_t* defined)
1299 {
1300   *defined = 0;
1301
1302   gold_assert(size == parameters->target().get_size());
1303
1304   if (dynobj->just_symbols())
1305     {
1306       gold_error(_("--just-symbols does not make sense with a shared object"));
1307       return;
1308     }
1309
1310   if (versym != NULL && versym_size / 2 < count)
1311     {
1312       dynobj->error(_("too few symbol versions"));
1313       return;
1314     }
1315
1316   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1317
1318   // We keep a list of all STT_OBJECT symbols, so that we can resolve
1319   // weak aliases.  This is necessary because if the dynamic object
1320   // provides the same variable under two names, one of which is a
1321   // weak definition, and the regular object refers to the weak
1322   // definition, we have to put both the weak definition and the
1323   // strong definition into the dynamic symbol table.  Given a weak
1324   // definition, the only way that we can find the corresponding
1325   // strong definition, if any, is to search the symbol table.
1326   std::vector<Sized_symbol<size>*> object_symbols;
1327
1328   const unsigned char* p = syms;
1329   const unsigned char* vs = versym;
1330   for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
1331     {
1332       elfcpp::Sym<size, big_endian> sym(p);
1333
1334       if (sympointers != NULL)
1335         (*sympointers)[i] = NULL;
1336
1337       // Ignore symbols with local binding or that have
1338       // internal or hidden visibility.
1339       if (sym.get_st_bind() == elfcpp::STB_LOCAL
1340           || sym.get_st_visibility() == elfcpp::STV_INTERNAL
1341           || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
1342         continue;
1343
1344       // A protected symbol in a shared library must be treated as a
1345       // normal symbol when viewed from outside the shared library.
1346       // Implement this by overriding the visibility here.
1347       elfcpp::Sym<size, big_endian>* psym = &sym;
1348       unsigned char symbuf[sym_size];
1349       elfcpp::Sym<size, big_endian> sym2(symbuf);
1350       if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
1351         {
1352           memcpy(symbuf, p, sym_size);
1353           elfcpp::Sym_write<size, big_endian> sw(symbuf);
1354           sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
1355           psym = &sym2;
1356         }
1357
1358       unsigned int st_name = psym->get_st_name();
1359       if (st_name >= sym_name_size)
1360         {
1361           dynobj->error(_("bad symbol name offset %u at %zu"),
1362                         st_name, i);
1363           continue;
1364         }
1365
1366       const char* name = sym_names + st_name;
1367
1368       bool is_ordinary;
1369       unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
1370                                                        &is_ordinary);
1371
1372       if (st_shndx != elfcpp::SHN_UNDEF)
1373         ++*defined;
1374
1375       Sized_symbol<size>* res;
1376
1377       if (versym == NULL)
1378         {
1379           Stringpool::Key name_key;
1380           name = this->namepool_.add(name, true, &name_key);
1381           res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1382                                       false, *psym, st_shndx, is_ordinary,
1383                                       st_shndx);
1384         }
1385       else
1386         {
1387           // Read the version information.
1388
1389           unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
1390
1391           bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
1392           v &= elfcpp::VERSYM_VERSION;
1393
1394           // The Sun documentation says that V can be VER_NDX_LOCAL,
1395           // or VER_NDX_GLOBAL, or a version index.  The meaning of
1396           // VER_NDX_LOCAL is defined as "Symbol has local scope."
1397           // The old GNU linker will happily generate VER_NDX_LOCAL
1398           // for an undefined symbol.  I don't know what the Sun
1399           // linker will generate.
1400
1401           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1402               && st_shndx != elfcpp::SHN_UNDEF)
1403             {
1404               // This symbol should not be visible outside the object.
1405               continue;
1406             }
1407
1408           // At this point we are definitely going to add this symbol.
1409           Stringpool::Key name_key;
1410           name = this->namepool_.add(name, true, &name_key);
1411
1412           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1413               || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1414             {
1415               // This symbol does not have a version.
1416               res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1417                                           false, *psym, st_shndx, is_ordinary,
1418                                           st_shndx);
1419             }
1420           else
1421             {
1422               if (v >= version_map->size())
1423                 {
1424                   dynobj->error(_("versym for symbol %zu out of range: %u"),
1425                                 i, v);
1426                   continue;
1427                 }
1428
1429               const char* version = (*version_map)[v];
1430               if (version == NULL)
1431                 {
1432                   dynobj->error(_("versym for symbol %zu has no name: %u"),
1433                                 i, v);
1434                   continue;
1435                 }
1436
1437               Stringpool::Key version_key;
1438               version = this->namepool_.add(version, true, &version_key);
1439
1440               // If this is an absolute symbol, and the version name
1441               // and symbol name are the same, then this is the
1442               // version definition symbol.  These symbols exist to
1443               // support using -u to pull in particular versions.  We
1444               // do not want to record a version for them.
1445               if (st_shndx == elfcpp::SHN_ABS
1446                   && !is_ordinary
1447                   && name_key == version_key)
1448                 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1449                                             false, *psym, st_shndx, is_ordinary,
1450                                             st_shndx);
1451               else
1452                 {
1453                   const bool is_default_version =
1454                     !hidden && st_shndx != elfcpp::SHN_UNDEF;
1455                   res = this->add_from_object(dynobj, name, name_key, version,
1456                                               version_key, is_default_version,
1457                                               *psym, st_shndx,
1458                                               is_ordinary, st_shndx);
1459                 }
1460             }
1461         }
1462
1463       // Note that it is possible that RES was overridden by an
1464       // earlier object, in which case it can't be aliased here.
1465       if (st_shndx != elfcpp::SHN_UNDEF
1466           && is_ordinary
1467           && psym->get_st_type() == elfcpp::STT_OBJECT
1468           && res->source() == Symbol::FROM_OBJECT
1469           && res->object() == dynobj)
1470         object_symbols.push_back(res);
1471
1472       if (sympointers != NULL)
1473         (*sympointers)[i] = res;
1474     }
1475
1476   this->record_weak_aliases(&object_symbols);
1477 }
1478
1479 // This is used to sort weak aliases.  We sort them first by section
1480 // index, then by offset, then by weak ahead of strong.
1481
1482 template<int size>
1483 class Weak_alias_sorter
1484 {
1485  public:
1486   bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1487 };
1488
1489 template<int size>
1490 bool
1491 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1492                                     const Sized_symbol<size>* s2) const
1493 {
1494   bool is_ordinary;
1495   unsigned int s1_shndx = s1->shndx(&is_ordinary);
1496   gold_assert(is_ordinary);
1497   unsigned int s2_shndx = s2->shndx(&is_ordinary);
1498   gold_assert(is_ordinary);
1499   if (s1_shndx != s2_shndx)
1500     return s1_shndx < s2_shndx;
1501
1502   if (s1->value() != s2->value())
1503     return s1->value() < s2->value();
1504   if (s1->binding() != s2->binding())
1505     {
1506       if (s1->binding() == elfcpp::STB_WEAK)
1507         return true;
1508       if (s2->binding() == elfcpp::STB_WEAK)
1509         return false;
1510     }
1511   return std::string(s1->name()) < std::string(s2->name());
1512 }
1513
1514 // SYMBOLS is a list of object symbols from a dynamic object.  Look
1515 // for any weak aliases, and record them so that if we add the weak
1516 // alias to the dynamic symbol table, we also add the corresponding
1517 // strong symbol.
1518
1519 template<int size>
1520 void
1521 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1522 {
1523   // Sort the vector by section index, then by offset, then by weak
1524   // ahead of strong.
1525   std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1526
1527   // Walk through the vector.  For each weak definition, record
1528   // aliases.
1529   for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1530          symbols->begin();
1531        p != symbols->end();
1532        ++p)
1533     {
1534       if ((*p)->binding() != elfcpp::STB_WEAK)
1535         continue;
1536
1537       // Build a circular list of weak aliases.  Each symbol points to
1538       // the next one in the circular list.
1539
1540       Sized_symbol<size>* from_sym = *p;
1541       typename std::vector<Sized_symbol<size>*>::const_iterator q;
1542       for (q = p + 1; q != symbols->end(); ++q)
1543         {
1544           bool dummy;
1545           if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1546               || (*q)->value() != from_sym->value())
1547             break;
1548
1549           this->weak_aliases_[from_sym] = *q;
1550           from_sym->set_has_alias();
1551           from_sym = *q;
1552         }
1553
1554       if (from_sym != *p)
1555         {
1556           this->weak_aliases_[from_sym] = *p;
1557           from_sym->set_has_alias();
1558         }
1559
1560       p = q - 1;
1561     }
1562 }
1563
1564 // Create and return a specially defined symbol.  If ONLY_IF_REF is
1565 // true, then only create the symbol if there is a reference to it.
1566 // If this does not return NULL, it sets *POLDSYM to the existing
1567 // symbol if there is one.  This sets *RESOLVE_OLDSYM if we should
1568 // resolve the newly created symbol to the old one.  This
1569 // canonicalizes *PNAME and *PVERSION.
1570
1571 template<int size, bool big_endian>
1572 Sized_symbol<size>*
1573 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1574                                     bool only_if_ref,
1575                                     Sized_symbol<size>** poldsym,
1576                                     bool* resolve_oldsym)
1577 {
1578   *resolve_oldsym = false;
1579
1580   // If the caller didn't give us a version, see if we get one from
1581   // the version script.
1582   std::string v;
1583   bool is_default_version = false;
1584   if (*pversion == NULL)
1585     {
1586       bool is_global;
1587       if (this->version_script_.get_symbol_version(*pname, &v, &is_global))
1588         {
1589           if (is_global && !v.empty())
1590             {
1591               *pversion = v.c_str();
1592               // If we get the version from a version script, then we
1593               // are also the default version.
1594               is_default_version = true;
1595             }
1596         }
1597     }
1598
1599   Symbol* oldsym;
1600   Sized_symbol<size>* sym;
1601
1602   bool add_to_table = false;
1603   typename Symbol_table_type::iterator add_loc = this->table_.end();
1604   bool add_def_to_table = false;
1605   typename Symbol_table_type::iterator add_def_loc = this->table_.end();
1606
1607   if (only_if_ref)
1608     {
1609       oldsym = this->lookup(*pname, *pversion);
1610       if (oldsym == NULL && is_default_version)
1611         oldsym = this->lookup(*pname, NULL);
1612       if (oldsym == NULL || !oldsym->is_undefined())
1613         return NULL;
1614
1615       *pname = oldsym->name();
1616       if (!is_default_version)
1617         *pversion = oldsym->version();
1618     }
1619   else
1620     {
1621       // Canonicalize NAME and VERSION.
1622       Stringpool::Key name_key;
1623       *pname = this->namepool_.add(*pname, true, &name_key);
1624
1625       Stringpool::Key version_key = 0;
1626       if (*pversion != NULL)
1627         *pversion = this->namepool_.add(*pversion, true, &version_key);
1628
1629       Symbol* const snull = NULL;
1630       std::pair<typename Symbol_table_type::iterator, bool> ins =
1631         this->table_.insert(std::make_pair(std::make_pair(name_key,
1632                                                           version_key),
1633                                            snull));
1634
1635       std::pair<typename Symbol_table_type::iterator, bool> insdefault =
1636         std::make_pair(this->table_.end(), false);
1637       if (is_default_version)
1638         {
1639           const Stringpool::Key vnull = 0;
1640           insdefault =
1641             this->table_.insert(std::make_pair(std::make_pair(name_key,
1642                                                               vnull),
1643                                                snull));
1644         }
1645
1646       if (!ins.second)
1647         {
1648           // We already have a symbol table entry for NAME/VERSION.
1649           oldsym = ins.first->second;
1650           gold_assert(oldsym != NULL);
1651
1652           if (is_default_version)
1653             {
1654               Sized_symbol<size>* soldsym =
1655                 this->get_sized_symbol<size>(oldsym);
1656               this->define_default_version<size, big_endian>(soldsym,
1657                                                              insdefault.second,
1658                                                              insdefault.first);
1659             }
1660         }
1661       else
1662         {
1663           // We haven't seen this symbol before.
1664           gold_assert(ins.first->second == NULL);
1665
1666           add_to_table = true;
1667           add_loc = ins.first;
1668
1669           if (is_default_version && !insdefault.second)
1670             {
1671               // We are adding NAME/VERSION, and it is the default
1672               // version.  We already have an entry for NAME/NULL.
1673               oldsym = insdefault.first->second;
1674               *resolve_oldsym = true;
1675             }
1676           else
1677             {
1678               oldsym = NULL;
1679
1680               if (is_default_version)
1681                 {
1682                   add_def_to_table = true;
1683                   add_def_loc = insdefault.first;
1684                 }
1685             }
1686         }
1687     }
1688
1689   const Target& target = parameters->target();
1690   if (!target.has_make_symbol())
1691     sym = new Sized_symbol<size>();
1692   else
1693     {
1694       Sized_target<size, big_endian>* sized_target =
1695         parameters->sized_target<size, big_endian>();
1696       sym = sized_target->make_symbol();
1697       if (sym == NULL)
1698         return NULL;
1699     }
1700
1701   if (add_to_table)
1702     add_loc->second = sym;
1703   else
1704     gold_assert(oldsym != NULL);
1705
1706   if (add_def_to_table)
1707     add_def_loc->second = sym;
1708
1709   *poldsym = this->get_sized_symbol<size>(oldsym);
1710
1711   return sym;
1712 }
1713
1714 // Define a symbol based on an Output_data.
1715
1716 Symbol*
1717 Symbol_table::define_in_output_data(const char* name,
1718                                     const char* version,
1719                                     Defined defined,
1720                                     Output_data* od,
1721                                     uint64_t value,
1722                                     uint64_t symsize,
1723                                     elfcpp::STT type,
1724                                     elfcpp::STB binding,
1725                                     elfcpp::STV visibility,
1726                                     unsigned char nonvis,
1727                                     bool offset_is_from_end,
1728                                     bool only_if_ref)
1729 {
1730   if (parameters->target().get_size() == 32)
1731     {
1732 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1733       return this->do_define_in_output_data<32>(name, version, defined, od,
1734                                                 value, symsize, type, binding,
1735                                                 visibility, nonvis,
1736                                                 offset_is_from_end,
1737                                                 only_if_ref);
1738 #else
1739       gold_unreachable();
1740 #endif
1741     }
1742   else if (parameters->target().get_size() == 64)
1743     {
1744 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1745       return this->do_define_in_output_data<64>(name, version, defined, od,
1746                                                 value, symsize, type, binding,
1747                                                 visibility, nonvis,
1748                                                 offset_is_from_end,
1749                                                 only_if_ref);
1750 #else
1751       gold_unreachable();
1752 #endif
1753     }
1754   else
1755     gold_unreachable();
1756 }
1757
1758 // Define a symbol in an Output_data, sized version.
1759
1760 template<int size>
1761 Sized_symbol<size>*
1762 Symbol_table::do_define_in_output_data(
1763     const char* name,
1764     const char* version,
1765     Defined defined,
1766     Output_data* od,
1767     typename elfcpp::Elf_types<size>::Elf_Addr value,
1768     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1769     elfcpp::STT type,
1770     elfcpp::STB binding,
1771     elfcpp::STV visibility,
1772     unsigned char nonvis,
1773     bool offset_is_from_end,
1774     bool only_if_ref)
1775 {
1776   Sized_symbol<size>* sym;
1777   Sized_symbol<size>* oldsym;
1778   bool resolve_oldsym;
1779
1780   if (parameters->target().is_big_endian())
1781     {
1782 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1783       sym = this->define_special_symbol<size, true>(&name, &version,
1784                                                     only_if_ref, &oldsym,
1785                                                     &resolve_oldsym);
1786 #else
1787       gold_unreachable();
1788 #endif
1789     }
1790   else
1791     {
1792 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1793       sym = this->define_special_symbol<size, false>(&name, &version,
1794                                                      only_if_ref, &oldsym,
1795                                                      &resolve_oldsym);
1796 #else
1797       gold_unreachable();
1798 #endif
1799     }
1800
1801   if (sym == NULL)
1802     return NULL;
1803
1804   sym->init_output_data(name, version, od, value, symsize, type, binding,
1805                         visibility, nonvis, offset_is_from_end);
1806
1807   if (oldsym == NULL)
1808     {
1809       if (binding == elfcpp::STB_LOCAL
1810           || this->version_script_.symbol_is_local(name))
1811         this->force_local(sym);
1812       else if (version != NULL)
1813         sym->set_is_default();
1814       return sym;
1815     }
1816
1817   if (Symbol_table::should_override_with_special(oldsym, defined))
1818     this->override_with_special(oldsym, sym);
1819
1820   if (resolve_oldsym)
1821     return sym;
1822   else
1823     {
1824       delete sym;
1825       return oldsym;
1826     }
1827 }
1828
1829 // Define a symbol based on an Output_segment.
1830
1831 Symbol*
1832 Symbol_table::define_in_output_segment(const char* name,
1833                                        const char* version,
1834                                        Defined defined,
1835                                        Output_segment* os,
1836                                        uint64_t value,
1837                                        uint64_t symsize,
1838                                        elfcpp::STT type,
1839                                        elfcpp::STB binding,
1840                                        elfcpp::STV visibility,
1841                                        unsigned char nonvis,
1842                                        Symbol::Segment_offset_base offset_base,
1843                                        bool only_if_ref)
1844 {
1845   if (parameters->target().get_size() == 32)
1846     {
1847 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1848       return this->do_define_in_output_segment<32>(name, version, defined, os,
1849                                                    value, symsize, type,
1850                                                    binding, visibility, nonvis,
1851                                                    offset_base, only_if_ref);
1852 #else
1853       gold_unreachable();
1854 #endif
1855     }
1856   else if (parameters->target().get_size() == 64)
1857     {
1858 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1859       return this->do_define_in_output_segment<64>(name, version, defined, os,
1860                                                    value, symsize, type,
1861                                                    binding, visibility, nonvis,
1862                                                    offset_base, only_if_ref);
1863 #else
1864       gold_unreachable();
1865 #endif
1866     }
1867   else
1868     gold_unreachable();
1869 }
1870
1871 // Define a symbol in an Output_segment, sized version.
1872
1873 template<int size>
1874 Sized_symbol<size>*
1875 Symbol_table::do_define_in_output_segment(
1876     const char* name,
1877     const char* version,
1878     Defined defined,
1879     Output_segment* os,
1880     typename elfcpp::Elf_types<size>::Elf_Addr value,
1881     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1882     elfcpp::STT type,
1883     elfcpp::STB binding,
1884     elfcpp::STV visibility,
1885     unsigned char nonvis,
1886     Symbol::Segment_offset_base offset_base,
1887     bool only_if_ref)
1888 {
1889   Sized_symbol<size>* sym;
1890   Sized_symbol<size>* oldsym;
1891   bool resolve_oldsym;
1892
1893   if (parameters->target().is_big_endian())
1894     {
1895 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1896       sym = this->define_special_symbol<size, true>(&name, &version,
1897                                                     only_if_ref, &oldsym,
1898                                                     &resolve_oldsym);
1899 #else
1900       gold_unreachable();
1901 #endif
1902     }
1903   else
1904     {
1905 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1906       sym = this->define_special_symbol<size, false>(&name, &version,
1907                                                      only_if_ref, &oldsym,
1908                                                      &resolve_oldsym);
1909 #else
1910       gold_unreachable();
1911 #endif
1912     }
1913
1914   if (sym == NULL)
1915     return NULL;
1916
1917   sym->init_output_segment(name, version, os, value, symsize, type, binding,
1918                            visibility, nonvis, offset_base);
1919
1920   if (oldsym == NULL)
1921     {
1922       if (binding == elfcpp::STB_LOCAL
1923           || this->version_script_.symbol_is_local(name))
1924         this->force_local(sym);
1925       else if (version != NULL)
1926         sym->set_is_default();
1927       return sym;
1928     }
1929
1930   if (Symbol_table::should_override_with_special(oldsym, defined))
1931     this->override_with_special(oldsym, sym);
1932
1933   if (resolve_oldsym)
1934     return sym;
1935   else
1936     {
1937       delete sym;
1938       return oldsym;
1939     }
1940 }
1941
1942 // Define a special symbol with a constant value.  It is a multiple
1943 // definition error if this symbol is already defined.
1944
1945 Symbol*
1946 Symbol_table::define_as_constant(const char* name,
1947                                  const char* version,
1948                                  Defined defined,
1949                                  uint64_t value,
1950                                  uint64_t symsize,
1951                                  elfcpp::STT type,
1952                                  elfcpp::STB binding,
1953                                  elfcpp::STV visibility,
1954                                  unsigned char nonvis,
1955                                  bool only_if_ref,
1956                                  bool force_override)
1957 {
1958   if (parameters->target().get_size() == 32)
1959     {
1960 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1961       return this->do_define_as_constant<32>(name, version, defined, value,
1962                                              symsize, type, binding,
1963                                              visibility, nonvis, only_if_ref,
1964                                              force_override);
1965 #else
1966       gold_unreachable();
1967 #endif
1968     }
1969   else if (parameters->target().get_size() == 64)
1970     {
1971 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1972       return this->do_define_as_constant<64>(name, version, defined, value,
1973                                              symsize, type, binding,
1974                                              visibility, nonvis, only_if_ref,
1975                                              force_override);
1976 #else
1977       gold_unreachable();
1978 #endif
1979     }
1980   else
1981     gold_unreachable();
1982 }
1983
1984 // Define a symbol as a constant, sized version.
1985
1986 template<int size>
1987 Sized_symbol<size>*
1988 Symbol_table::do_define_as_constant(
1989     const char* name,
1990     const char* version,
1991     Defined defined,
1992     typename elfcpp::Elf_types<size>::Elf_Addr value,
1993     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1994     elfcpp::STT type,
1995     elfcpp::STB binding,
1996     elfcpp::STV visibility,
1997     unsigned char nonvis,
1998     bool only_if_ref,
1999     bool force_override)
2000 {
2001   Sized_symbol<size>* sym;
2002   Sized_symbol<size>* oldsym;
2003   bool resolve_oldsym;
2004
2005   if (parameters->target().is_big_endian())
2006     {
2007 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2008       sym = this->define_special_symbol<size, true>(&name, &version,
2009                                                     only_if_ref, &oldsym,
2010                                                     &resolve_oldsym);
2011 #else
2012       gold_unreachable();
2013 #endif
2014     }
2015   else
2016     {
2017 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2018       sym = this->define_special_symbol<size, false>(&name, &version,
2019                                                      only_if_ref, &oldsym,
2020                                                      &resolve_oldsym);
2021 #else
2022       gold_unreachable();
2023 #endif
2024     }
2025
2026   if (sym == NULL)
2027     return NULL;
2028
2029   sym->init_constant(name, version, value, symsize, type, binding, visibility,
2030                      nonvis);
2031
2032   if (oldsym == NULL)
2033     {
2034       // Version symbols are absolute symbols with name == version.
2035       // We don't want to force them to be local.
2036       if ((version == NULL
2037            || name != version
2038            || value != 0)
2039           && (binding == elfcpp::STB_LOCAL
2040               || this->version_script_.symbol_is_local(name)))
2041         this->force_local(sym);
2042       else if (version != NULL
2043                && (name != version || value != 0))
2044         sym->set_is_default();
2045       return sym;
2046     }
2047
2048   if (force_override
2049       || Symbol_table::should_override_with_special(oldsym, defined))
2050     this->override_with_special(oldsym, sym);
2051
2052   if (resolve_oldsym)
2053     return sym;
2054   else
2055     {
2056       delete sym;
2057       return oldsym;
2058     }
2059 }
2060
2061 // Define a set of symbols in output sections.
2062
2063 void
2064 Symbol_table::define_symbols(const Layout* layout, int count,
2065                              const Define_symbol_in_section* p,
2066                              bool only_if_ref)
2067 {
2068   for (int i = 0; i < count; ++i, ++p)
2069     {
2070       Output_section* os = layout->find_output_section(p->output_section);
2071       if (os != NULL)
2072         this->define_in_output_data(p->name, NULL, PREDEFINED, os, p->value,
2073                                     p->size, p->type, p->binding,
2074                                     p->visibility, p->nonvis,
2075                                     p->offset_is_from_end,
2076                                     only_if_ref || p->only_if_ref);
2077       else
2078         this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2079                                  p->type, p->binding, p->visibility, p->nonvis,
2080                                  only_if_ref || p->only_if_ref,
2081                                  false);
2082     }
2083 }
2084
2085 // Define a set of symbols in output segments.
2086
2087 void
2088 Symbol_table::define_symbols(const Layout* layout, int count,
2089                              const Define_symbol_in_segment* p,
2090                              bool only_if_ref)
2091 {
2092   for (int i = 0; i < count; ++i, ++p)
2093     {
2094       Output_segment* os = layout->find_output_segment(p->segment_type,
2095                                                        p->segment_flags_set,
2096                                                        p->segment_flags_clear);
2097       if (os != NULL)
2098         this->define_in_output_segment(p->name, NULL, PREDEFINED, os, p->value,
2099                                        p->size, p->type, p->binding,
2100                                        p->visibility, p->nonvis,
2101                                        p->offset_base,
2102                                        only_if_ref || p->only_if_ref);
2103       else
2104         this->define_as_constant(p->name, NULL, PREDEFINED, 0, p->size,
2105                                  p->type, p->binding, p->visibility, p->nonvis,
2106                                  only_if_ref || p->only_if_ref,
2107                                  false);
2108     }
2109 }
2110
2111 // Define CSYM using a COPY reloc.  POSD is the Output_data where the
2112 // symbol should be defined--typically a .dyn.bss section.  VALUE is
2113 // the offset within POSD.
2114
2115 template<int size>
2116 void
2117 Symbol_table::define_with_copy_reloc(
2118     Sized_symbol<size>* csym,
2119     Output_data* posd,
2120     typename elfcpp::Elf_types<size>::Elf_Addr value)
2121 {
2122   gold_assert(csym->is_from_dynobj());
2123   gold_assert(!csym->is_copied_from_dynobj());
2124   Object* object = csym->object();
2125   gold_assert(object->is_dynamic());
2126   Dynobj* dynobj = static_cast<Dynobj*>(object);
2127
2128   // Our copied variable has to override any variable in a shared
2129   // library.
2130   elfcpp::STB binding = csym->binding();
2131   if (binding == elfcpp::STB_WEAK)
2132     binding = elfcpp::STB_GLOBAL;
2133
2134   this->define_in_output_data(csym->name(), csym->version(), COPY,
2135                               posd, value, csym->symsize(),
2136                               csym->type(), binding,
2137                               csym->visibility(), csym->nonvis(),
2138                               false, false);
2139
2140   csym->set_is_copied_from_dynobj();
2141   csym->set_needs_dynsym_entry();
2142
2143   this->copied_symbol_dynobjs_[csym] = dynobj;
2144
2145   // We have now defined all aliases, but we have not entered them all
2146   // in the copied_symbol_dynobjs_ map.
2147   if (csym->has_alias())
2148     {
2149       Symbol* sym = csym;
2150       while (true)
2151         {
2152           sym = this->weak_aliases_[sym];
2153           if (sym == csym)
2154             break;
2155           gold_assert(sym->output_data() == posd);
2156
2157           sym->set_is_copied_from_dynobj();
2158           this->copied_symbol_dynobjs_[sym] = dynobj;
2159         }
2160     }
2161 }
2162
2163 // SYM is defined using a COPY reloc.  Return the dynamic object where
2164 // the original definition was found.
2165
2166 Dynobj*
2167 Symbol_table::get_copy_source(const Symbol* sym) const
2168 {
2169   gold_assert(sym->is_copied_from_dynobj());
2170   Copied_symbol_dynobjs::const_iterator p =
2171     this->copied_symbol_dynobjs_.find(sym);
2172   gold_assert(p != this->copied_symbol_dynobjs_.end());
2173   return p->second;
2174 }
2175
2176 // Add any undefined symbols named on the command line.
2177
2178 void
2179 Symbol_table::add_undefined_symbols_from_command_line(Layout* layout)
2180 {
2181   if (parameters->options().any_undefined()
2182       || layout->script_options()->any_unreferenced())
2183     {
2184       if (parameters->target().get_size() == 32)
2185         {
2186 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2187           this->do_add_undefined_symbols_from_command_line<32>(layout);
2188 #else
2189           gold_unreachable();
2190 #endif
2191         }
2192       else if (parameters->target().get_size() == 64)
2193         {
2194 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2195           this->do_add_undefined_symbols_from_command_line<64>(layout);
2196 #else
2197           gold_unreachable();
2198 #endif
2199         }
2200       else
2201         gold_unreachable();
2202     }
2203 }
2204
2205 template<int size>
2206 void
2207 Symbol_table::do_add_undefined_symbols_from_command_line(Layout* layout)
2208 {
2209   for (options::String_set::const_iterator p =
2210          parameters->options().undefined_begin();
2211        p != parameters->options().undefined_end();
2212        ++p)
2213     this->add_undefined_symbol_from_command_line<size>(p->c_str());
2214
2215   for (Script_options::referenced_const_iterator p =
2216          layout->script_options()->referenced_begin();
2217        p != layout->script_options()->referenced_end();
2218        ++p)
2219     this->add_undefined_symbol_from_command_line<size>(p->c_str());
2220 }
2221
2222 template<int size>
2223 void
2224 Symbol_table::add_undefined_symbol_from_command_line(const char* name)
2225 {
2226   if (this->lookup(name) != NULL)
2227     return;
2228
2229   const char* version = NULL;
2230
2231   Sized_symbol<size>* sym;
2232   Sized_symbol<size>* oldsym;
2233   bool resolve_oldsym;
2234   if (parameters->target().is_big_endian())
2235     {
2236 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
2237       sym = this->define_special_symbol<size, true>(&name, &version,
2238                                                     false, &oldsym,
2239                                                     &resolve_oldsym);
2240 #else
2241       gold_unreachable();
2242 #endif
2243     }
2244   else
2245     {
2246 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
2247       sym = this->define_special_symbol<size, false>(&name, &version,
2248                                                      false, &oldsym,
2249                                                      &resolve_oldsym);
2250 #else
2251       gold_unreachable();
2252 #endif
2253     }
2254
2255   gold_assert(oldsym == NULL);
2256
2257   sym->init_undefined(name, version, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
2258                       elfcpp::STV_DEFAULT, 0);
2259   ++this->saw_undefined_;
2260 }
2261
2262 // Set the dynamic symbol indexes.  INDEX is the index of the first
2263 // global dynamic symbol.  Pointers to the symbols are stored into the
2264 // vector SYMS.  The names are added to DYNPOOL.  This returns an
2265 // updated dynamic symbol index.
2266
2267 unsigned int
2268 Symbol_table::set_dynsym_indexes(unsigned int index,
2269                                  std::vector<Symbol*>* syms,
2270                                  Stringpool* dynpool,
2271                                  Versions* versions)
2272 {
2273   for (Symbol_table_type::iterator p = this->table_.begin();
2274        p != this->table_.end();
2275        ++p)
2276     {
2277       Symbol* sym = p->second;
2278
2279       // Note that SYM may already have a dynamic symbol index, since
2280       // some symbols appear more than once in the symbol table, with
2281       // and without a version.
2282
2283       if (!sym->should_add_dynsym_entry(this))
2284         sym->set_dynsym_index(-1U);
2285       else if (!sym->has_dynsym_index())
2286         {
2287           sym->set_dynsym_index(index);
2288           ++index;
2289           syms->push_back(sym);
2290           dynpool->add(sym->name(), false, NULL);
2291
2292           // Record any version information.
2293           if (sym->version() != NULL)
2294             versions->record_version(this, dynpool, sym);
2295
2296           // If the symbol is defined in a dynamic object and is
2297           // referenced in a regular object, then mark the dynamic
2298           // object as needed.  This is used to implement --as-needed.
2299           if (sym->is_from_dynobj() && sym->in_reg())
2300             sym->object()->set_is_needed();
2301         }
2302     }
2303
2304   // Finish up the versions.  In some cases this may add new dynamic
2305   // symbols.
2306   index = versions->finalize(this, index, syms);
2307
2308   return index;
2309 }
2310
2311 // Set the final values for all the symbols.  The index of the first
2312 // global symbol in the output file is *PLOCAL_SYMCOUNT.  Record the
2313 // file offset OFF.  Add their names to POOL.  Return the new file
2314 // offset.  Update *PLOCAL_SYMCOUNT if necessary.
2315
2316 off_t
2317 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
2318                        size_t dyncount, Stringpool* pool,
2319                        unsigned int* plocal_symcount)
2320 {
2321   off_t ret;
2322
2323   gold_assert(*plocal_symcount != 0);
2324   this->first_global_index_ = *plocal_symcount;
2325
2326   this->dynamic_offset_ = dynoff;
2327   this->first_dynamic_global_index_ = dyn_global_index;
2328   this->dynamic_count_ = dyncount;
2329
2330   if (parameters->target().get_size() == 32)
2331     {
2332 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
2333       ret = this->sized_finalize<32>(off, pool, plocal_symcount);
2334 #else
2335       gold_unreachable();
2336 #endif
2337     }
2338   else if (parameters->target().get_size() == 64)
2339     {
2340 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
2341       ret = this->sized_finalize<64>(off, pool, plocal_symcount);
2342 #else
2343       gold_unreachable();
2344 #endif
2345     }
2346   else
2347     gold_unreachable();
2348
2349   // Now that we have the final symbol table, we can reliably note
2350   // which symbols should get warnings.
2351   this->warnings_.note_warnings(this);
2352
2353   return ret;
2354 }
2355
2356 // SYM is going into the symbol table at *PINDEX.  Add the name to
2357 // POOL, update *PINDEX and *POFF.
2358
2359 template<int size>
2360 void
2361 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
2362                                   unsigned int* pindex, off_t* poff)
2363 {
2364   sym->set_symtab_index(*pindex);
2365   pool->add(sym->name(), false, NULL);
2366   ++*pindex;
2367   *poff += elfcpp::Elf_sizes<size>::sym_size;
2368 }
2369
2370 // Set the final value for all the symbols.  This is called after
2371 // Layout::finalize, so all the output sections have their final
2372 // address.
2373
2374 template<int size>
2375 off_t
2376 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
2377                              unsigned int* plocal_symcount)
2378 {
2379   off = align_address(off, size >> 3);
2380   this->offset_ = off;
2381
2382   unsigned int index = *plocal_symcount;
2383   const unsigned int orig_index = index;
2384
2385   // First do all the symbols which have been forced to be local, as
2386   // they must appear before all global symbols.
2387   for (Forced_locals::iterator p = this->forced_locals_.begin();
2388        p != this->forced_locals_.end();
2389        ++p)
2390     {
2391       Symbol* sym = *p;
2392       gold_assert(sym->is_forced_local());
2393       if (this->sized_finalize_symbol<size>(sym))
2394         {
2395           this->add_to_final_symtab<size>(sym, pool, &index, &off);
2396           ++*plocal_symcount;
2397         }
2398     }
2399
2400   // Now do all the remaining symbols.
2401   for (Symbol_table_type::iterator p = this->table_.begin();
2402        p != this->table_.end();
2403        ++p)
2404     {
2405       Symbol* sym = p->second;
2406       if (this->sized_finalize_symbol<size>(sym))
2407         this->add_to_final_symtab<size>(sym, pool, &index, &off);
2408     }
2409
2410   this->output_count_ = index - orig_index;
2411
2412   return off;
2413 }
2414
2415 // Compute the final value of SYM and store status in location PSTATUS.
2416 // During relaxation, this may be called multiple times for a symbol to
2417 // compute its would-be final value in each relaxation pass.
2418
2419 template<int size>
2420 typename Sized_symbol<size>::Value_type
2421 Symbol_table::compute_final_value(
2422     const Sized_symbol<size>* sym,
2423     Compute_final_value_status* pstatus) const
2424 {
2425   typedef typename Sized_symbol<size>::Value_type Value_type;
2426   Value_type value;
2427
2428   switch (sym->source())
2429     {
2430     case Symbol::FROM_OBJECT:
2431       {
2432         bool is_ordinary;
2433         unsigned int shndx = sym->shndx(&is_ordinary);
2434
2435         if (!is_ordinary
2436             && shndx != elfcpp::SHN_ABS
2437             && !Symbol::is_common_shndx(shndx))
2438           {
2439             *pstatus = CFVS_UNSUPPORTED_SYMBOL_SECTION;
2440             return 0;
2441           }
2442
2443         Object* symobj = sym->object();
2444         if (symobj->is_dynamic())
2445           {
2446             value = 0;
2447             shndx = elfcpp::SHN_UNDEF;
2448           }
2449         else if (symobj->pluginobj() != NULL)
2450           {
2451             value = 0;
2452             shndx = elfcpp::SHN_UNDEF;
2453           }
2454         else if (shndx == elfcpp::SHN_UNDEF)
2455           value = 0;
2456         else if (!is_ordinary
2457                  && (shndx == elfcpp::SHN_ABS
2458                      || Symbol::is_common_shndx(shndx)))
2459           value = sym->value();
2460         else
2461           {
2462             Relobj* relobj = static_cast<Relobj*>(symobj);
2463             Output_section* os = relobj->output_section(shndx);
2464
2465             if (this->is_section_folded(relobj, shndx))
2466               {
2467                 gold_assert(os == NULL);
2468                 // Get the os of the section it is folded onto.
2469                 Section_id folded = this->icf_->get_folded_section(relobj,
2470                                                                    shndx);
2471                 gold_assert(folded.first != NULL);
2472                 Relobj* folded_obj = reinterpret_cast<Relobj*>(folded.first);
2473                 unsigned folded_shndx = folded.second;
2474
2475                 os = folded_obj->output_section(folded_shndx);  
2476                 gold_assert(os != NULL);
2477
2478                 // Replace (relobj, shndx) with canonical ICF input section.
2479                 shndx = folded_shndx;
2480                 relobj = folded_obj;
2481               }
2482
2483             uint64_t secoff64 = relobj->output_section_offset(shndx);
2484             if (os == NULL)
2485               {
2486                 bool static_or_reloc = (parameters->doing_static_link() ||
2487                                         parameters->options().relocatable());
2488                 gold_assert(static_or_reloc || sym->dynsym_index() == -1U);
2489
2490                 *pstatus = CFVS_NO_OUTPUT_SECTION;
2491                 return 0;
2492               }
2493
2494             if (secoff64 == -1ULL)
2495               {
2496                 // The section needs special handling (e.g., a merge section).
2497
2498                 value = os->output_address(relobj, shndx, sym->value());
2499               }
2500             else
2501               {
2502                 Value_type secoff =
2503                   convert_types<Value_type, uint64_t>(secoff64);
2504                 if (sym->type() == elfcpp::STT_TLS)
2505                   value = sym->value() + os->tls_offset() + secoff;
2506                 else
2507                   value = sym->value() + os->address() + secoff;
2508               }
2509           }
2510       }
2511       break;
2512
2513     case Symbol::IN_OUTPUT_DATA:
2514       {
2515         Output_data* od = sym->output_data();
2516         value = sym->value();
2517         if (sym->type() != elfcpp::STT_TLS)
2518           value += od->address();
2519         else
2520           {
2521             Output_section* os = od->output_section();
2522             gold_assert(os != NULL);
2523             value += os->tls_offset() + (od->address() - os->address());
2524           }
2525         if (sym->offset_is_from_end())
2526           value += od->data_size();
2527       }
2528       break;
2529
2530     case Symbol::IN_OUTPUT_SEGMENT:
2531       {
2532         Output_segment* os = sym->output_segment();
2533         value = sym->value();
2534         if (sym->type() != elfcpp::STT_TLS)
2535           value += os->vaddr();
2536         switch (sym->offset_base())
2537           {
2538           case Symbol::SEGMENT_START:
2539             break;
2540           case Symbol::SEGMENT_END:
2541             value += os->memsz();
2542             break;
2543           case Symbol::SEGMENT_BSS:
2544             value += os->filesz();
2545             break;
2546           default:
2547             gold_unreachable();
2548           }
2549       }
2550       break;
2551
2552     case Symbol::IS_CONSTANT:
2553       value = sym->value();
2554       break;
2555
2556     case Symbol::IS_UNDEFINED:
2557       value = 0;
2558       break;
2559
2560     default:
2561       gold_unreachable();
2562     }
2563
2564   *pstatus = CFVS_OK;
2565   return value;
2566 }
2567
2568 // Finalize the symbol SYM.  This returns true if the symbol should be
2569 // added to the symbol table, false otherwise.
2570
2571 template<int size>
2572 bool
2573 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
2574 {
2575   typedef typename Sized_symbol<size>::Value_type Value_type;
2576
2577   Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
2578
2579   // The default version of a symbol may appear twice in the symbol
2580   // table.  We only need to finalize it once.
2581   if (sym->has_symtab_index())
2582     return false;
2583
2584   if (!sym->in_reg())
2585     {
2586       gold_assert(!sym->has_symtab_index());
2587       sym->set_symtab_index(-1U);
2588       gold_assert(sym->dynsym_index() == -1U);
2589       return false;
2590     }
2591
2592   // Compute final symbol value.
2593   Compute_final_value_status status;
2594   Value_type value = this->compute_final_value(sym, &status);
2595
2596   switch (status)
2597     {
2598     case CFVS_OK:
2599       break;
2600     case CFVS_UNSUPPORTED_SYMBOL_SECTION:
2601       {
2602         bool is_ordinary;
2603         unsigned int shndx = sym->shndx(&is_ordinary);
2604         gold_error(_("%s: unsupported symbol section 0x%x"),
2605                    sym->demangled_name().c_str(), shndx);
2606       }
2607       break;
2608     case CFVS_NO_OUTPUT_SECTION:
2609       sym->set_symtab_index(-1U);
2610       return false;
2611     default:
2612       gold_unreachable();
2613     }
2614
2615   sym->set_value(value);
2616
2617   if (parameters->options().strip_all()
2618       || !parameters->options().should_retain_symbol(sym->name()))
2619     {
2620       sym->set_symtab_index(-1U);
2621       return false;
2622     }
2623
2624   return true;
2625 }
2626
2627 // Write out the global symbols.
2628
2629 void
2630 Symbol_table::write_globals(const Stringpool* sympool,
2631                             const Stringpool* dynpool,
2632                             Output_symtab_xindex* symtab_xindex,
2633                             Output_symtab_xindex* dynsym_xindex,
2634                             Output_file* of) const
2635 {
2636   switch (parameters->size_and_endianness())
2637     {
2638 #ifdef HAVE_TARGET_32_LITTLE
2639     case Parameters::TARGET_32_LITTLE:
2640       this->sized_write_globals<32, false>(sympool, dynpool, symtab_xindex,
2641                                            dynsym_xindex, of);
2642       break;
2643 #endif
2644 #ifdef HAVE_TARGET_32_BIG
2645     case Parameters::TARGET_32_BIG:
2646       this->sized_write_globals<32, true>(sympool, dynpool, symtab_xindex,
2647                                           dynsym_xindex, of);
2648       break;
2649 #endif
2650 #ifdef HAVE_TARGET_64_LITTLE
2651     case Parameters::TARGET_64_LITTLE:
2652       this->sized_write_globals<64, false>(sympool, dynpool, symtab_xindex,
2653                                            dynsym_xindex, of);
2654       break;
2655 #endif
2656 #ifdef HAVE_TARGET_64_BIG
2657     case Parameters::TARGET_64_BIG:
2658       this->sized_write_globals<64, true>(sympool, dynpool, symtab_xindex,
2659                                           dynsym_xindex, of);
2660       break;
2661 #endif
2662     default:
2663       gold_unreachable();
2664     }
2665 }
2666
2667 // Write out the global symbols.
2668
2669 template<int size, bool big_endian>
2670 void
2671 Symbol_table::sized_write_globals(const Stringpool* sympool,
2672                                   const Stringpool* dynpool,
2673                                   Output_symtab_xindex* symtab_xindex,
2674                                   Output_symtab_xindex* dynsym_xindex,
2675                                   Output_file* of) const
2676 {
2677   const Target& target = parameters->target();
2678
2679   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2680
2681   const unsigned int output_count = this->output_count_;
2682   const section_size_type oview_size = output_count * sym_size;
2683   const unsigned int first_global_index = this->first_global_index_;
2684   unsigned char* psyms;
2685   if (this->offset_ == 0 || output_count == 0)
2686     psyms = NULL;
2687   else
2688     psyms = of->get_output_view(this->offset_, oview_size);
2689
2690   const unsigned int dynamic_count = this->dynamic_count_;
2691   const section_size_type dynamic_size = dynamic_count * sym_size;
2692   const unsigned int first_dynamic_global_index =
2693     this->first_dynamic_global_index_;
2694   unsigned char* dynamic_view;
2695   if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2696     dynamic_view = NULL;
2697   else
2698     dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2699
2700   for (Symbol_table_type::const_iterator p = this->table_.begin();
2701        p != this->table_.end();
2702        ++p)
2703     {
2704       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2705
2706       // Possibly warn about unresolved symbols in shared libraries.
2707       this->warn_about_undefined_dynobj_symbol(sym);
2708
2709       unsigned int sym_index = sym->symtab_index();
2710       unsigned int dynsym_index;
2711       if (dynamic_view == NULL)
2712         dynsym_index = -1U;
2713       else
2714         dynsym_index = sym->dynsym_index();
2715
2716       if (sym_index == -1U && dynsym_index == -1U)
2717         {
2718           // This symbol is not included in the output file.
2719           continue;
2720         }
2721
2722       unsigned int shndx;
2723       typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2724       typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2725       elfcpp::STB binding = sym->binding();
2726       switch (sym->source())
2727         {
2728         case Symbol::FROM_OBJECT:
2729           {
2730             bool is_ordinary;
2731             unsigned int in_shndx = sym->shndx(&is_ordinary);
2732
2733             if (!is_ordinary
2734                 && in_shndx != elfcpp::SHN_ABS
2735                 && !Symbol::is_common_shndx(in_shndx))
2736               {
2737                 gold_error(_("%s: unsupported symbol section 0x%x"),
2738                            sym->demangled_name().c_str(), in_shndx);
2739                 shndx = in_shndx;
2740               }
2741             else
2742               {
2743                 Object* symobj = sym->object();
2744                 if (symobj->is_dynamic())
2745                   {
2746                     if (sym->needs_dynsym_value())
2747                       dynsym_value = target.dynsym_value(sym);
2748                     shndx = elfcpp::SHN_UNDEF;
2749                     if (sym->is_undef_binding_weak())
2750                       binding = elfcpp::STB_WEAK;
2751                     else
2752                       binding = elfcpp::STB_GLOBAL;
2753                   }
2754                 else if (symobj->pluginobj() != NULL)
2755                   shndx = elfcpp::SHN_UNDEF;
2756                 else if (in_shndx == elfcpp::SHN_UNDEF
2757                          || (!is_ordinary
2758                              && (in_shndx == elfcpp::SHN_ABS
2759                                  || Symbol::is_common_shndx(in_shndx))))
2760                   shndx = in_shndx;
2761                 else
2762                   {
2763                     Relobj* relobj = static_cast<Relobj*>(symobj);
2764                     Output_section* os = relobj->output_section(in_shndx);
2765                     if (this->is_section_folded(relobj, in_shndx))
2766                       {
2767                         // This global symbol must be written out even though
2768                         // it is folded.
2769                         // Get the os of the section it is folded onto.
2770                         Section_id folded =
2771                              this->icf_->get_folded_section(relobj, in_shndx);
2772                         gold_assert(folded.first !=NULL);
2773                         Relobj* folded_obj = 
2774                           reinterpret_cast<Relobj*>(folded.first);
2775                         os = folded_obj->output_section(folded.second);  
2776                         gold_assert(os != NULL);
2777                       }
2778                     gold_assert(os != NULL);
2779                     shndx = os->out_shndx();
2780
2781                     if (shndx >= elfcpp::SHN_LORESERVE)
2782                       {
2783                         if (sym_index != -1U)
2784                           symtab_xindex->add(sym_index, shndx);
2785                         if (dynsym_index != -1U)
2786                           dynsym_xindex->add(dynsym_index, shndx);
2787                         shndx = elfcpp::SHN_XINDEX;
2788                       }
2789
2790                     // In object files symbol values are section
2791                     // relative.
2792                     if (parameters->options().relocatable())
2793                       sym_value -= os->address();
2794                   }
2795               }
2796           }
2797           break;
2798
2799         case Symbol::IN_OUTPUT_DATA:
2800           shndx = sym->output_data()->out_shndx();
2801           if (shndx >= elfcpp::SHN_LORESERVE)
2802             {
2803               if (sym_index != -1U)
2804                 symtab_xindex->add(sym_index, shndx);
2805               if (dynsym_index != -1U)
2806                 dynsym_xindex->add(dynsym_index, shndx);
2807               shndx = elfcpp::SHN_XINDEX;
2808             }
2809           break;
2810
2811         case Symbol::IN_OUTPUT_SEGMENT:
2812           shndx = elfcpp::SHN_ABS;
2813           break;
2814
2815         case Symbol::IS_CONSTANT:
2816           shndx = elfcpp::SHN_ABS;
2817           break;
2818
2819         case Symbol::IS_UNDEFINED:
2820           shndx = elfcpp::SHN_UNDEF;
2821           break;
2822
2823         default:
2824           gold_unreachable();
2825         }
2826
2827       if (sym_index != -1U)
2828         {
2829           sym_index -= first_global_index;
2830           gold_assert(sym_index < output_count);
2831           unsigned char* ps = psyms + (sym_index * sym_size);
2832           this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2833                                                      binding, sympool, ps);
2834         }
2835
2836       if (dynsym_index != -1U)
2837         {
2838           dynsym_index -= first_dynamic_global_index;
2839           gold_assert(dynsym_index < dynamic_count);
2840           unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2841           this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2842                                                      binding, dynpool, pd);
2843         }
2844     }
2845
2846   of->write_output_view(this->offset_, oview_size, psyms);
2847   if (dynamic_view != NULL)
2848     of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2849 }
2850
2851 // Write out the symbol SYM, in section SHNDX, to P.  POOL is the
2852 // strtab holding the name.
2853
2854 template<int size, bool big_endian>
2855 void
2856 Symbol_table::sized_write_symbol(
2857     Sized_symbol<size>* sym,
2858     typename elfcpp::Elf_types<size>::Elf_Addr value,
2859     unsigned int shndx,
2860     elfcpp::STB binding,
2861     const Stringpool* pool,
2862     unsigned char* p) const
2863 {
2864   elfcpp::Sym_write<size, big_endian> osym(p);
2865   osym.put_st_name(pool->get_offset(sym->name()));
2866   osym.put_st_value(value);
2867   // Use a symbol size of zero for undefined symbols from shared libraries.
2868   if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
2869     osym.put_st_size(0);
2870   else
2871     osym.put_st_size(sym->symsize());
2872   elfcpp::STT type = sym->type();
2873   // Turn IFUNC symbols from shared libraries into normal FUNC symbols.
2874   if (type == elfcpp::STT_GNU_IFUNC
2875       && sym->is_from_dynobj())
2876     type = elfcpp::STT_FUNC;
2877   // A version script may have overridden the default binding.
2878   if (sym->is_forced_local())
2879     osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, type));
2880   else
2881     osym.put_st_info(elfcpp::elf_st_info(binding, type));
2882   osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2883   osym.put_st_shndx(shndx);
2884 }
2885
2886 // Check for unresolved symbols in shared libraries.  This is
2887 // controlled by the --allow-shlib-undefined option.
2888
2889 // We only warn about libraries for which we have seen all the
2890 // DT_NEEDED entries.  We don't try to track down DT_NEEDED entries
2891 // which were not seen in this link.  If we didn't see a DT_NEEDED
2892 // entry, we aren't going to be able to reliably report whether the
2893 // symbol is undefined.
2894
2895 // We also don't warn about libraries found in a system library
2896 // directory (e.g., /lib or /usr/lib); we assume that those libraries
2897 // are OK.  This heuristic avoids problems on GNU/Linux, in which -ldl
2898 // can have undefined references satisfied by ld-linux.so.
2899
2900 inline void
2901 Symbol_table::warn_about_undefined_dynobj_symbol(Symbol* sym) const
2902 {
2903   bool dummy;
2904   if (sym->source() == Symbol::FROM_OBJECT
2905       && sym->object()->is_dynamic()
2906       && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2907       && sym->binding() != elfcpp::STB_WEAK
2908       && !parameters->options().allow_shlib_undefined()
2909       && !parameters->target().is_defined_by_abi(sym)
2910       && !sym->object()->is_in_system_directory())
2911     {
2912       // A very ugly cast.
2913       Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2914       if (!dynobj->has_unknown_needed_entries())
2915         gold_undefined_symbol(sym);
2916     }
2917 }
2918
2919 // Write out a section symbol.  Return the update offset.
2920
2921 void
2922 Symbol_table::write_section_symbol(const Output_section* os,
2923                                    Output_symtab_xindex* symtab_xindex,
2924                                    Output_file* of,
2925                                    off_t offset) const
2926 {
2927   switch (parameters->size_and_endianness())
2928     {
2929 #ifdef HAVE_TARGET_32_LITTLE
2930     case Parameters::TARGET_32_LITTLE:
2931       this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2932                                                   offset);
2933       break;
2934 #endif
2935 #ifdef HAVE_TARGET_32_BIG
2936     case Parameters::TARGET_32_BIG:
2937       this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2938                                                  offset);
2939       break;
2940 #endif
2941 #ifdef HAVE_TARGET_64_LITTLE
2942     case Parameters::TARGET_64_LITTLE:
2943       this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2944                                                   offset);
2945       break;
2946 #endif
2947 #ifdef HAVE_TARGET_64_BIG
2948     case Parameters::TARGET_64_BIG:
2949       this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2950                                                  offset);
2951       break;
2952 #endif
2953     default:
2954       gold_unreachable();
2955     }
2956 }
2957
2958 // Write out a section symbol, specialized for size and endianness.
2959
2960 template<int size, bool big_endian>
2961 void
2962 Symbol_table::sized_write_section_symbol(const Output_section* os,
2963                                          Output_symtab_xindex* symtab_xindex,
2964                                          Output_file* of,
2965                                          off_t offset) const
2966 {
2967   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2968
2969   unsigned char* pov = of->get_output_view(offset, sym_size);
2970
2971   elfcpp::Sym_write<size, big_endian> osym(pov);
2972   osym.put_st_name(0);
2973   if (parameters->options().relocatable())
2974     osym.put_st_value(0);
2975   else
2976     osym.put_st_value(os->address());
2977   osym.put_st_size(0);
2978   osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2979                                        elfcpp::STT_SECTION));
2980   osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2981
2982   unsigned int shndx = os->out_shndx();
2983   if (shndx >= elfcpp::SHN_LORESERVE)
2984     {
2985       symtab_xindex->add(os->symtab_index(), shndx);
2986       shndx = elfcpp::SHN_XINDEX;
2987     }
2988   osym.put_st_shndx(shndx);
2989
2990   of->write_output_view(offset, sym_size, pov);
2991 }
2992
2993 // Print statistical information to stderr.  This is used for --stats.
2994
2995 void
2996 Symbol_table::print_stats() const
2997 {
2998 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2999   fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
3000           program_name, this->table_.size(), this->table_.bucket_count());
3001 #else
3002   fprintf(stderr, _("%s: symbol table entries: %zu\n"),
3003           program_name, this->table_.size());
3004 #endif
3005   this->namepool_.print_stats("symbol table stringpool");
3006 }
3007
3008 // We check for ODR violations by looking for symbols with the same
3009 // name for which the debugging information reports that they were
3010 // defined in different source locations.  When comparing the source
3011 // location, we consider instances with the same base filename and
3012 // line number to be the same.  This is because different object
3013 // files/shared libraries can include the same header file using
3014 // different paths, and we don't want to report an ODR violation in
3015 // that case.
3016
3017 // This struct is used to compare line information, as returned by
3018 // Dwarf_line_info::one_addr2line.  It implements a < comparison
3019 // operator used with std::set.
3020
3021 struct Odr_violation_compare
3022 {
3023   bool
3024   operator()(const std::string& s1, const std::string& s2) const
3025   {
3026     std::string::size_type pos1 = s1.rfind('/');
3027     std::string::size_type pos2 = s2.rfind('/');
3028     if (pos1 == std::string::npos
3029         || pos2 == std::string::npos)
3030       return s1 < s2;
3031     return s1.compare(pos1, std::string::npos,
3032                       s2, pos2, std::string::npos) < 0;
3033   }
3034 };
3035
3036 // Check candidate_odr_violations_ to find symbols with the same name
3037 // but apparently different definitions (different source-file/line-no).
3038
3039 void
3040 Symbol_table::detect_odr_violations(const Task* task,
3041                                     const char* output_file_name) const
3042 {
3043   for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
3044        it != candidate_odr_violations_.end();
3045        ++it)
3046     {
3047       const char* symbol_name = it->first;
3048       // Maps from symbol location to a sample object file we found
3049       // that location in.  We use a sorted map so the location order
3050       // is deterministic, but we only store an arbitrary object file
3051       // to avoid copying lots of names.
3052       std::map<std::string, std::string, Odr_violation_compare> line_nums;
3053
3054       for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
3055                locs = it->second.begin();
3056            locs != it->second.end();
3057            ++locs)
3058         {
3059           // We need to lock the object in order to read it.  This
3060           // means that we have to run in a singleton Task.  If we
3061           // want to run this in a general Task for better
3062           // performance, we will need one Task for object, plus
3063           // appropriate locking to ensure that we don't conflict with
3064           // other uses of the object.  Also note, one_addr2line is not
3065           // currently thread-safe.
3066           Task_lock_obj<Object> tl(task, locs->object);
3067           // 16 is the size of the object-cache that one_addr2line should use.
3068           std::string lineno = Dwarf_line_info::one_addr2line(
3069               locs->object, locs->shndx, locs->offset, 16);
3070           if (!lineno.empty())
3071             {
3072               std::string& sample_object = line_nums[lineno];
3073               if (sample_object.empty())
3074                 sample_object = locs->object->name();
3075             }
3076         }
3077
3078       if (line_nums.size() > 1)
3079         {
3080           gold_warning(_("while linking %s: symbol '%s' defined in multiple "
3081                          "places (possible ODR violation):"),
3082                        output_file_name, demangle(symbol_name).c_str());
3083           for (std::map<std::string, std::string>::const_iterator it2 =
3084                  line_nums.begin();
3085                it2 != line_nums.end();
3086                ++it2)
3087             fprintf(stderr, _("  %s from %s\n"),
3088                     it2->first.c_str(), it2->second.c_str());
3089         }
3090     }
3091   // We only call one_addr2line() in this function, so we can clear its cache.
3092   Dwarf_line_info::clear_addr2line_cache();
3093 }
3094
3095 // Warnings functions.
3096
3097 // Add a new warning.
3098
3099 void
3100 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
3101                       const std::string& warning)
3102 {
3103   name = symtab->canonicalize_name(name);
3104   this->warnings_[name].set(obj, warning);
3105 }
3106
3107 // Look through the warnings and mark the symbols for which we should
3108 // warn.  This is called during Layout::finalize when we know the
3109 // sources for all the symbols.
3110
3111 void
3112 Warnings::note_warnings(Symbol_table* symtab)
3113 {
3114   for (Warning_table::iterator p = this->warnings_.begin();
3115        p != this->warnings_.end();
3116        ++p)
3117     {
3118       Symbol* sym = symtab->lookup(p->first, NULL);
3119       if (sym != NULL
3120           && sym->source() == Symbol::FROM_OBJECT
3121           && sym->object() == p->second.object)
3122         sym->set_has_warning();
3123     }
3124 }
3125
3126 // Issue a warning.  This is called when we see a relocation against a
3127 // symbol for which has a warning.
3128
3129 template<int size, bool big_endian>
3130 void
3131 Warnings::issue_warning(const Symbol* sym,
3132                         const Relocate_info<size, big_endian>* relinfo,
3133                         size_t relnum, off_t reloffset) const
3134 {
3135   gold_assert(sym->has_warning());
3136   Warning_table::const_iterator p = this->warnings_.find(sym->name());
3137   gold_assert(p != this->warnings_.end());
3138   gold_warning_at_location(relinfo, relnum, reloffset,
3139                            "%s", p->second.text.c_str());
3140 }
3141
3142 // Instantiate the templates we need.  We could use the configure
3143 // script to restrict this to only the ones needed for implemented
3144 // targets.
3145
3146 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3147 template
3148 void
3149 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
3150 #endif
3151
3152 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3153 template
3154 void
3155 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
3156 #endif
3157
3158 #ifdef HAVE_TARGET_32_LITTLE
3159 template
3160 void
3161 Symbol_table::add_from_relobj<32, false>(
3162     Sized_relobj<32, false>* relobj,
3163     const unsigned char* syms,
3164     size_t count,
3165     size_t symndx_offset,
3166     const char* sym_names,
3167     size_t sym_name_size,
3168     Sized_relobj<32, false>::Symbols* sympointers,
3169     size_t* defined);
3170 #endif
3171
3172 #ifdef HAVE_TARGET_32_BIG
3173 template
3174 void
3175 Symbol_table::add_from_relobj<32, true>(
3176     Sized_relobj<32, true>* relobj,
3177     const unsigned char* syms,
3178     size_t count,
3179     size_t symndx_offset,
3180     const char* sym_names,
3181     size_t sym_name_size,
3182     Sized_relobj<32, true>::Symbols* sympointers,
3183     size_t* defined);
3184 #endif
3185
3186 #ifdef HAVE_TARGET_64_LITTLE
3187 template
3188 void
3189 Symbol_table::add_from_relobj<64, false>(
3190     Sized_relobj<64, false>* relobj,
3191     const unsigned char* syms,
3192     size_t count,
3193     size_t symndx_offset,
3194     const char* sym_names,
3195     size_t sym_name_size,
3196     Sized_relobj<64, false>::Symbols* sympointers,
3197     size_t* defined);
3198 #endif
3199
3200 #ifdef HAVE_TARGET_64_BIG
3201 template
3202 void
3203 Symbol_table::add_from_relobj<64, true>(
3204     Sized_relobj<64, true>* relobj,
3205     const unsigned char* syms,
3206     size_t count,
3207     size_t symndx_offset,
3208     const char* sym_names,
3209     size_t sym_name_size,
3210     Sized_relobj<64, true>::Symbols* sympointers,
3211     size_t* defined);
3212 #endif
3213
3214 #ifdef HAVE_TARGET_32_LITTLE
3215 template
3216 Symbol*
3217 Symbol_table::add_from_pluginobj<32, false>(
3218     Sized_pluginobj<32, false>* obj,
3219     const char* name,
3220     const char* ver,
3221     elfcpp::Sym<32, false>* sym);
3222 #endif
3223
3224 #ifdef HAVE_TARGET_32_BIG
3225 template
3226 Symbol*
3227 Symbol_table::add_from_pluginobj<32, true>(
3228     Sized_pluginobj<32, true>* obj,
3229     const char* name,
3230     const char* ver,
3231     elfcpp::Sym<32, true>* sym);
3232 #endif
3233
3234 #ifdef HAVE_TARGET_64_LITTLE
3235 template
3236 Symbol*
3237 Symbol_table::add_from_pluginobj<64, false>(
3238     Sized_pluginobj<64, false>* obj,
3239     const char* name,
3240     const char* ver,
3241     elfcpp::Sym<64, false>* sym);
3242 #endif
3243
3244 #ifdef HAVE_TARGET_64_BIG
3245 template
3246 Symbol*
3247 Symbol_table::add_from_pluginobj<64, true>(
3248     Sized_pluginobj<64, true>* obj,
3249     const char* name,
3250     const char* ver,
3251     elfcpp::Sym<64, true>* sym);
3252 #endif
3253
3254 #ifdef HAVE_TARGET_32_LITTLE
3255 template
3256 void
3257 Symbol_table::add_from_dynobj<32, false>(
3258     Sized_dynobj<32, false>* dynobj,
3259     const unsigned char* syms,
3260     size_t count,
3261     const char* sym_names,
3262     size_t sym_name_size,
3263     const unsigned char* versym,
3264     size_t versym_size,
3265     const std::vector<const char*>* version_map,
3266     Sized_relobj<32, false>::Symbols* sympointers,
3267     size_t* defined);
3268 #endif
3269
3270 #ifdef HAVE_TARGET_32_BIG
3271 template
3272 void
3273 Symbol_table::add_from_dynobj<32, true>(
3274     Sized_dynobj<32, true>* dynobj,
3275     const unsigned char* syms,
3276     size_t count,
3277     const char* sym_names,
3278     size_t sym_name_size,
3279     const unsigned char* versym,
3280     size_t versym_size,
3281     const std::vector<const char*>* version_map,
3282     Sized_relobj<32, true>::Symbols* sympointers,
3283     size_t* defined);
3284 #endif
3285
3286 #ifdef HAVE_TARGET_64_LITTLE
3287 template
3288 void
3289 Symbol_table::add_from_dynobj<64, false>(
3290     Sized_dynobj<64, false>* dynobj,
3291     const unsigned char* syms,
3292     size_t count,
3293     const char* sym_names,
3294     size_t sym_name_size,
3295     const unsigned char* versym,
3296     size_t versym_size,
3297     const std::vector<const char*>* version_map,
3298     Sized_relobj<64, false>::Symbols* sympointers,
3299     size_t* defined);
3300 #endif
3301
3302 #ifdef HAVE_TARGET_64_BIG
3303 template
3304 void
3305 Symbol_table::add_from_dynobj<64, true>(
3306     Sized_dynobj<64, true>* dynobj,
3307     const unsigned char* syms,
3308     size_t count,
3309     const char* sym_names,
3310     size_t sym_name_size,
3311     const unsigned char* versym,
3312     size_t versym_size,
3313     const std::vector<const char*>* version_map,
3314     Sized_relobj<64, true>::Symbols* sympointers,
3315     size_t* defined);
3316 #endif
3317
3318 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
3319 template
3320 void
3321 Symbol_table::define_with_copy_reloc<32>(
3322     Sized_symbol<32>* sym,
3323     Output_data* posd,
3324     elfcpp::Elf_types<32>::Elf_Addr value);
3325 #endif
3326
3327 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
3328 template
3329 void
3330 Symbol_table::define_with_copy_reloc<64>(
3331     Sized_symbol<64>* sym,
3332     Output_data* posd,
3333     elfcpp::Elf_types<64>::Elf_Addr value);
3334 #endif
3335
3336 #ifdef HAVE_TARGET_32_LITTLE
3337 template
3338 void
3339 Warnings::issue_warning<32, false>(const Symbol* sym,
3340                                    const Relocate_info<32, false>* relinfo,
3341                                    size_t relnum, off_t reloffset) const;
3342 #endif
3343
3344 #ifdef HAVE_TARGET_32_BIG
3345 template
3346 void
3347 Warnings::issue_warning<32, true>(const Symbol* sym,
3348                                   const Relocate_info<32, true>* relinfo,
3349                                   size_t relnum, off_t reloffset) const;
3350 #endif
3351
3352 #ifdef HAVE_TARGET_64_LITTLE
3353 template
3354 void
3355 Warnings::issue_warning<64, false>(const Symbol* sym,
3356                                    const Relocate_info<64, false>* relinfo,
3357                                    size_t relnum, off_t reloffset) const;
3358 #endif
3359
3360 #ifdef HAVE_TARGET_64_BIG
3361 template
3362 void
3363 Warnings::issue_warning<64, true>(const Symbol* sym,
3364                                   const Relocate_info<64, true>* relinfo,
3365                                   size_t relnum, off_t reloffset) const;
3366 #endif
3367
3368 } // End namespace gold.