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