* errors.cc (Errors::info): New function.
[external/binutils.git] / gold / symtab.cc
1 // symtab.cc -- the gold symbol table
2
3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cstring>
26 #include <stdint.h>
27 #include <algorithm>
28 #include <set>
29 #include <string>
30 #include <utility>
31 #include "demangle.h"
32
33 #include "object.h"
34 #include "dwarf_reader.h"
35 #include "dynobj.h"
36 #include "output.h"
37 #include "target.h"
38 #include "workqueue.h"
39 #include "symtab.h"
40
41 namespace gold
42 {
43
44 // Class Symbol.
45
46 // Initialize fields in Symbol.  This initializes everything except u_
47 // and source_.
48
49 void
50 Symbol::init_fields(const char* name, const char* version,
51                     elfcpp::STT type, elfcpp::STB binding,
52                     elfcpp::STV visibility, unsigned char nonvis)
53 {
54   this->name_ = name;
55   this->version_ = version;
56   this->symtab_index_ = 0;
57   this->dynsym_index_ = 0;
58   this->got_offsets_.init();
59   this->plt_offset_ = 0;
60   this->type_ = type;
61   this->binding_ = binding;
62   this->visibility_ = visibility;
63   this->nonvis_ = nonvis;
64   this->is_target_special_ = false;
65   this->is_def_ = false;
66   this->is_forwarder_ = false;
67   this->has_alias_ = false;
68   this->needs_dynsym_entry_ = false;
69   this->in_reg_ = false;
70   this->in_dyn_ = false;
71   this->has_plt_offset_ = false;
72   this->has_warning_ = false;
73   this->is_copied_from_dynobj_ = false;
74   this->is_forced_local_ = false;
75 }
76
77 // Return the demangled version of the symbol's name, but only
78 // if the --demangle flag was set.
79
80 static std::string
81 demangle(const char* name)
82 {
83   if (!parameters->options().do_demangle())
84     return name;
85
86   // cplus_demangle allocates memory for the result it returns,
87   // and returns NULL if the name is already demangled.
88   char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
89   if (demangled_name == NULL)
90     return name;
91
92   std::string retval(demangled_name);
93   free(demangled_name);
94   return retval;
95 }
96
97 std::string
98 Symbol::demangled_name() const
99 {
100   return demangle(this->name());
101 }
102
103 // Initialize the fields in the base class Symbol for SYM in OBJECT.
104
105 template<int size, bool big_endian>
106 void
107 Symbol::init_base(const char* name, const char* version, Object* object,
108                   const elfcpp::Sym<size, big_endian>& sym)
109 {
110   this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
111                     sym.get_st_visibility(), sym.get_st_nonvis());
112   this->u_.from_object.object = object;
113   // FIXME: Handle SHN_XINDEX.
114   this->u_.from_object.shndx = sym.get_st_shndx();
115   this->source_ = FROM_OBJECT;
116   this->in_reg_ = !object->is_dynamic();
117   this->in_dyn_ = object->is_dynamic();
118 }
119
120 // Initialize the fields in the base class Symbol for a symbol defined
121 // in an Output_data.
122
123 void
124 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
125                   elfcpp::STB binding, elfcpp::STV visibility,
126                   unsigned char nonvis, bool offset_is_from_end)
127 {
128   this->init_fields(name, NULL, type, binding, visibility, nonvis);
129   this->u_.in_output_data.output_data = od;
130   this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
131   this->source_ = IN_OUTPUT_DATA;
132   this->in_reg_ = true;
133 }
134
135 // Initialize the fields in the base class Symbol for a symbol defined
136 // in an Output_segment.
137
138 void
139 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
140                   elfcpp::STB binding, elfcpp::STV visibility,
141                   unsigned char nonvis, Segment_offset_base offset_base)
142 {
143   this->init_fields(name, NULL, type, binding, visibility, nonvis);
144   this->u_.in_output_segment.output_segment = os;
145   this->u_.in_output_segment.offset_base = offset_base;
146   this->source_ = IN_OUTPUT_SEGMENT;
147   this->in_reg_ = true;
148 }
149
150 // Initialize the fields in the base class Symbol for a symbol defined
151 // as a constant.
152
153 void
154 Symbol::init_base(const char* name, elfcpp::STT type,
155                   elfcpp::STB binding, elfcpp::STV visibility,
156                   unsigned char nonvis)
157 {
158   this->init_fields(name, NULL, type, binding, visibility, nonvis);
159   this->source_ = CONSTANT;
160   this->in_reg_ = true;
161 }
162
163 // Allocate a common symbol in the base.
164
165 void
166 Symbol::allocate_base_common(Output_data* od)
167 {
168   gold_assert(this->is_common());
169   this->source_ = IN_OUTPUT_DATA;
170   this->u_.in_output_data.output_data = od;
171   this->u_.in_output_data.offset_is_from_end = false;
172 }
173
174 // Initialize the fields in Sized_symbol for SYM in OBJECT.
175
176 template<int size>
177 template<bool big_endian>
178 void
179 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
180                          const elfcpp::Sym<size, big_endian>& sym)
181 {
182   this->init_base(name, version, object, sym);
183   this->value_ = sym.get_st_value();
184   this->symsize_ = sym.get_st_size();
185 }
186
187 // Initialize the fields in Sized_symbol for a symbol defined in an
188 // Output_data.
189
190 template<int size>
191 void
192 Sized_symbol<size>::init(const char* name, Output_data* od,
193                          Value_type value, Size_type symsize,
194                          elfcpp::STT type, elfcpp::STB binding,
195                          elfcpp::STV visibility, unsigned char nonvis,
196                          bool offset_is_from_end)
197 {
198   this->init_base(name, od, type, binding, visibility, nonvis,
199                   offset_is_from_end);
200   this->value_ = value;
201   this->symsize_ = symsize;
202 }
203
204 // Initialize the fields in Sized_symbol for a symbol defined in an
205 // Output_segment.
206
207 template<int size>
208 void
209 Sized_symbol<size>::init(const char* name, Output_segment* os,
210                          Value_type value, Size_type symsize,
211                          elfcpp::STT type, elfcpp::STB binding,
212                          elfcpp::STV visibility, unsigned char nonvis,
213                          Segment_offset_base offset_base)
214 {
215   this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
216   this->value_ = value;
217   this->symsize_ = symsize;
218 }
219
220 // Initialize the fields in Sized_symbol for a symbol defined as a
221 // constant.
222
223 template<int size>
224 void
225 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
226                          elfcpp::STT type, elfcpp::STB binding,
227                          elfcpp::STV visibility, unsigned char nonvis)
228 {
229   this->init_base(name, type, binding, visibility, nonvis);
230   this->value_ = value;
231   this->symsize_ = symsize;
232 }
233
234 // Allocate a common symbol.
235
236 template<int size>
237 void
238 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
239 {
240   this->allocate_base_common(od);
241   this->value_ = value;
242 }
243
244 // Return true if this symbol should be added to the dynamic symbol
245 // table.
246
247 inline bool
248 Symbol::should_add_dynsym_entry() const
249 {
250   // If the symbol is used by a dynamic relocation, we need to add it.
251   if (this->needs_dynsym_entry())
252     return true;
253
254   // If the symbol was forced local in a version script, do not add it.
255   if (this->is_forced_local())
256     return false;
257
258   // If exporting all symbols or building a shared library,
259   // and the symbol is defined in a regular object and is
260   // externally visible, we need to add it.
261   if ((parameters->options().export_dynamic() || parameters->options().shared())
262       && !this->is_from_dynobj()
263       && this->is_externally_visible())
264     return true;
265
266   return false;
267 }
268
269 // Return true if the final value of this symbol is known at link
270 // time.
271
272 bool
273 Symbol::final_value_is_known() const
274 {
275   // If we are not generating an executable, then no final values are
276   // known, since they will change at runtime.
277   if (parameters->options().shared() || parameters->options().relocatable())
278     return false;
279
280   // If the symbol is not from an object file, then it is defined, and
281   // known.
282   if (this->source_ != FROM_OBJECT)
283     return true;
284
285   // If the symbol is from a dynamic object, then the final value is
286   // not known.
287   if (this->object()->is_dynamic())
288     return false;
289
290   // If the symbol is not undefined (it is defined or common), then
291   // the final value is known.
292   if (!this->is_undefined())
293     return true;
294
295   // If the symbol is undefined, then whether the final value is known
296   // depends on whether we are doing a static link.  If we are doing a
297   // dynamic link, then the final value could be filled in at runtime.
298   // This could reasonably be the case for a weak undefined symbol.
299   return parameters->doing_static_link();
300 }
301
302 // Return the output section where this symbol is defined.
303
304 Output_section*
305 Symbol::output_section() const
306 {
307   switch (this->source_)
308     {
309     case FROM_OBJECT:
310       {
311         unsigned int shndx = this->u_.from_object.shndx;
312         if (shndx != elfcpp::SHN_UNDEF && shndx < elfcpp::SHN_LORESERVE)
313           {
314             gold_assert(!this->u_.from_object.object->is_dynamic());
315             Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
316             section_offset_type dummy;
317             return relobj->output_section(shndx, &dummy);
318           }
319         return NULL;
320       }
321
322     case IN_OUTPUT_DATA:
323       return this->u_.in_output_data.output_data->output_section();
324
325     case IN_OUTPUT_SEGMENT:
326     case CONSTANT:
327       return NULL;
328
329     default:
330       gold_unreachable();
331     }
332 }
333
334 // Set the symbol's output section.  This is used for symbols defined
335 // in scripts.  This should only be called after the symbol table has
336 // been finalized.
337
338 void
339 Symbol::set_output_section(Output_section* os)
340 {
341   switch (this->source_)
342     {
343     case FROM_OBJECT:
344     case IN_OUTPUT_DATA:
345       gold_assert(this->output_section() == os);
346       break;
347     case CONSTANT:
348       this->source_ = IN_OUTPUT_DATA;
349       this->u_.in_output_data.output_data = os;
350       this->u_.in_output_data.offset_is_from_end = false;
351       break;
352     case IN_OUTPUT_SEGMENT:
353     default:
354       gold_unreachable();
355     }
356 }
357
358 // Class Symbol_table.
359
360 Symbol_table::Symbol_table(unsigned int count,
361                            const Version_script_info& version_script)
362   : saw_undefined_(0), offset_(0), table_(count), namepool_(),
363     forwarders_(), commons_(), tls_commons_(), forced_locals_(), warnings_(),
364     version_script_(version_script)
365 {
366   namepool_.reserve(count);
367 }
368
369 Symbol_table::~Symbol_table()
370 {
371 }
372
373 // The hash function.  The key values are Stringpool keys.
374
375 inline size_t
376 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
377 {
378   return key.first ^ key.second;
379 }
380
381 // The symbol table key equality function.  This is called with
382 // Stringpool keys.
383
384 inline bool
385 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
386                                           const Symbol_table_key& k2) const
387 {
388   return k1.first == k2.first && k1.second == k2.second;
389 }
390
391 // Make TO a symbol which forwards to FROM.
392
393 void
394 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
395 {
396   gold_assert(from != to);
397   gold_assert(!from->is_forwarder() && !to->is_forwarder());
398   this->forwarders_[from] = to;
399   from->set_forwarder();
400 }
401
402 // Resolve the forwards from FROM, returning the real symbol.
403
404 Symbol*
405 Symbol_table::resolve_forwards(const Symbol* from) const
406 {
407   gold_assert(from->is_forwarder());
408   Unordered_map<const Symbol*, Symbol*>::const_iterator p =
409     this->forwarders_.find(from);
410   gold_assert(p != this->forwarders_.end());
411   return p->second;
412 }
413
414 // Look up a symbol by name.
415
416 Symbol*
417 Symbol_table::lookup(const char* name, const char* version) const
418 {
419   Stringpool::Key name_key;
420   name = this->namepool_.find(name, &name_key);
421   if (name == NULL)
422     return NULL;
423
424   Stringpool::Key version_key = 0;
425   if (version != NULL)
426     {
427       version = this->namepool_.find(version, &version_key);
428       if (version == NULL)
429         return NULL;
430     }
431
432   Symbol_table_key key(name_key, version_key);
433   Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
434   if (p == this->table_.end())
435     return NULL;
436   return p->second;
437 }
438
439 // Resolve a Symbol with another Symbol.  This is only used in the
440 // unusual case where there are references to both an unversioned
441 // symbol and a symbol with a version, and we then discover that that
442 // version is the default version.  Because this is unusual, we do
443 // this the slow way, by converting back to an ELF symbol.
444
445 template<int size, bool big_endian>
446 void
447 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
448                       const char* version)
449 {
450   unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
451   elfcpp::Sym_write<size, big_endian> esym(buf);
452   // We don't bother to set the st_name field.
453   esym.put_st_value(from->value());
454   esym.put_st_size(from->symsize());
455   esym.put_st_info(from->binding(), from->type());
456   esym.put_st_other(from->visibility(), from->nonvis());
457   esym.put_st_shndx(from->shndx());
458   this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
459   if (from->in_reg())
460     to->set_in_reg();
461   if (from->in_dyn())
462     to->set_in_dyn();
463 }
464
465 // Record that a symbol is forced to be local by a version script.
466
467 void
468 Symbol_table::force_local(Symbol* sym)
469 {
470   if (!sym->is_defined() && !sym->is_common())
471     return;
472   if (sym->is_forced_local())
473     {
474       // We already got this one.
475       return;
476     }
477   sym->set_is_forced_local();
478   this->forced_locals_.push_back(sym);
479 }
480
481 // Adjust NAME for wrapping, and update *NAME_KEY if necessary.  This
482 // is only called for undefined symbols, when at least one --wrap
483 // option was used.
484
485 const char*
486 Symbol_table::wrap_symbol(Object* object, const char* name,
487                           Stringpool::Key* name_key)
488 {
489   // For some targets, we need to ignore a specific character when
490   // wrapping, and add it back later.
491   char prefix = '\0';
492   if (name[0] == object->target()->wrap_char())
493     {
494       prefix = name[0];
495       ++name;
496     }
497
498   if (parameters->options().is_wrap(name))
499     {
500       // Turn NAME into __wrap_NAME.
501       std::string s;
502       if (prefix != '\0')
503         s += prefix;
504       s += "__wrap_";
505       s += name;
506
507       // This will give us both the old and new name in NAMEPOOL_, but
508       // that is OK.  Only the versions we need will wind up in the
509       // real string table in the output file.
510       return this->namepool_.add(s.c_str(), true, name_key);
511     }
512
513   const char* const real_prefix = "__real_";
514   const size_t real_prefix_length = strlen(real_prefix);
515   if (strncmp(name, real_prefix, real_prefix_length) == 0
516       && parameters->options().is_wrap(name + real_prefix_length))
517     {
518       // Turn __real_NAME into NAME.
519       std::string s;
520       if (prefix != '\0')
521         s += prefix;
522       s += name + real_prefix_length;
523       return this->namepool_.add(s.c_str(), true, name_key);
524     }
525
526   return name;
527 }
528
529 // Add one symbol from OBJECT to the symbol table.  NAME is symbol
530 // name and VERSION is the version; both are canonicalized.  DEF is
531 // whether this is the default version.
532
533 // If DEF is true, then this is the definition of a default version of
534 // a symbol.  That means that any lookup of NAME/NULL and any lookup
535 // of NAME/VERSION should always return the same symbol.  This is
536 // obvious for references, but in particular we want to do this for
537 // definitions: overriding NAME/NULL should also override
538 // NAME/VERSION.  If we don't do that, it would be very hard to
539 // override functions in a shared library which uses versioning.
540
541 // We implement this by simply making both entries in the hash table
542 // point to the same Symbol structure.  That is easy enough if this is
543 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
544 // that we have seen both already, in which case they will both have
545 // independent entries in the symbol table.  We can't simply change
546 // the symbol table entry, because we have pointers to the entries
547 // attached to the object files.  So we mark the entry attached to the
548 // object file as a forwarder, and record it in the forwarders_ map.
549 // Note that entries in the hash table will never be marked as
550 // forwarders.
551 //
552 // SYM and ORIG_SYM are almost always the same.  ORIG_SYM is the
553 // symbol exactly as it existed in the input file.  SYM is usually
554 // that as well, but can be modified, for instance if we determine
555 // it's in a to-be-discarded section.
556
557 template<int size, bool big_endian>
558 Sized_symbol<size>*
559 Symbol_table::add_from_object(Object* object,
560                               const char *name,
561                               Stringpool::Key name_key,
562                               const char *version,
563                               Stringpool::Key version_key,
564                               bool def,
565                               const elfcpp::Sym<size, big_endian>& sym,
566                               const elfcpp::Sym<size, big_endian>& orig_sym)
567 {
568   // Print a message if this symbol is being traced.
569   if (parameters->options().is_trace_symbol(name))
570     {
571       if (orig_sym.get_st_shndx() == elfcpp::SHN_UNDEF)
572         gold_info(_("%s: reference to %s"), object->name().c_str(), name);
573       else
574         gold_info(_("%s: definition of %s"), object->name().c_str(), name);
575     }
576
577   // For an undefined symbol, we may need to adjust the name using
578   // --wrap.
579   if (orig_sym.get_st_shndx() == elfcpp::SHN_UNDEF
580       && parameters->options().any_wrap())
581     {
582       const char* wrap_name = this->wrap_symbol(object, name, &name_key);
583       if (wrap_name != name)
584         {
585           // If we see a reference to malloc with version GLIBC_2.0,
586           // and we turn it into a reference to __wrap_malloc, then we
587           // discard the version number.  Otherwise the user would be
588           // required to specify the correct version for
589           // __wrap_malloc.
590           version = NULL;
591           version_key = 0;
592           name = wrap_name;
593         }
594     }
595
596   Symbol* const snull = NULL;
597   std::pair<typename Symbol_table_type::iterator, bool> ins =
598     this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
599                                        snull));
600
601   std::pair<typename Symbol_table_type::iterator, bool> insdef =
602     std::make_pair(this->table_.end(), false);
603   if (def)
604     {
605       const Stringpool::Key vnull_key = 0;
606       insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
607                                                                  vnull_key),
608                                                   snull));
609     }
610
611   // ins.first: an iterator, which is a pointer to a pair.
612   // ins.first->first: the key (a pair of name and version).
613   // ins.first->second: the value (Symbol*).
614   // ins.second: true if new entry was inserted, false if not.
615
616   Sized_symbol<size>* ret;
617   bool was_undefined;
618   bool was_common;
619   if (!ins.second)
620     {
621       // We already have an entry for NAME/VERSION.
622       ret = this->get_sized_symbol<size>(ins.first->second);
623       gold_assert(ret != NULL);
624
625       was_undefined = ret->is_undefined();
626       was_common = ret->is_common();
627
628       this->resolve(ret, sym, orig_sym, object, version);
629
630       if (def)
631         {
632           if (insdef.second)
633             {
634               // This is the first time we have seen NAME/NULL.  Make
635               // NAME/NULL point to NAME/VERSION.
636               insdef.first->second = ret;
637             }
638           else if (insdef.first->second != ret
639                    && insdef.first->second->is_undefined())
640             {
641               // This is the unfortunate case where we already have
642               // entries for both NAME/VERSION and NAME/NULL.  Note
643               // that we don't want to combine them if the existing
644               // symbol is going to override the new one.  FIXME: We
645               // currently just test is_undefined, but this may not do
646               // the right thing if the existing symbol is from a
647               // shared library and the new one is from a regular
648               // object.
649
650               const Sized_symbol<size>* sym2;
651               sym2 = this->get_sized_symbol<size>(insdef.first->second);
652               Symbol_table::resolve<size, big_endian>(ret, sym2, version);
653               this->make_forwarder(insdef.first->second, ret);
654               insdef.first->second = ret;
655             }
656           else
657             def = false;
658         }
659     }
660   else
661     {
662       // This is the first time we have seen NAME/VERSION.
663       gold_assert(ins.first->second == NULL);
664
665       if (def && !insdef.second)
666         {
667           // We already have an entry for NAME/NULL.  If we override
668           // it, then change it to NAME/VERSION.
669           ret = this->get_sized_symbol<size>(insdef.first->second);
670
671           was_undefined = ret->is_undefined();
672           was_common = ret->is_common();
673
674           this->resolve(ret, sym, orig_sym, object, version);
675           ins.first->second = ret;
676         }
677       else
678         {
679           was_undefined = false;
680           was_common = false;
681
682           Sized_target<size, big_endian>* target =
683             object->sized_target<size, big_endian>();
684           if (!target->has_make_symbol())
685             ret = new Sized_symbol<size>();
686           else
687             {
688               ret = target->make_symbol();
689               if (ret == NULL)
690                 {
691                   // This means that we don't want a symbol table
692                   // entry after all.
693                   if (!def)
694                     this->table_.erase(ins.first);
695                   else
696                     {
697                       this->table_.erase(insdef.first);
698                       // Inserting insdef invalidated ins.
699                       this->table_.erase(std::make_pair(name_key,
700                                                         version_key));
701                     }
702                   return NULL;
703                 }
704             }
705
706           ret->init(name, version, object, sym);
707
708           ins.first->second = ret;
709           if (def)
710             {
711               // This is the first time we have seen NAME/NULL.  Point
712               // it at the new entry for NAME/VERSION.
713               gold_assert(insdef.second);
714               insdef.first->second = ret;
715             }
716         }
717     }
718
719   // Record every time we see a new undefined symbol, to speed up
720   // archive groups.
721   if (!was_undefined && ret->is_undefined())
722     ++this->saw_undefined_;
723
724   // Keep track of common symbols, to speed up common symbol
725   // allocation.
726   if (!was_common && ret->is_common())
727     {
728       if (ret->type() != elfcpp::STT_TLS)
729         this->commons_.push_back(ret);
730       else
731         this->tls_commons_.push_back(ret);
732     }
733
734   if (def)
735     ret->set_is_default();
736   return ret;
737 }
738
739 // Add all the symbols in a relocatable object to the hash table.
740
741 template<int size, bool big_endian>
742 void
743 Symbol_table::add_from_relobj(
744     Sized_relobj<size, big_endian>* relobj,
745     const unsigned char* syms,
746     size_t count,
747     const char* sym_names,
748     size_t sym_name_size,
749     typename Sized_relobj<size, big_endian>::Symbols* sympointers)
750 {
751   gold_assert(size == relobj->target()->get_size());
752   gold_assert(size == parameters->target().get_size());
753
754   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
755
756   const bool just_symbols = relobj->just_symbols();
757
758   const unsigned char* p = syms;
759   for (size_t i = 0; i < count; ++i, p += sym_size)
760     {
761       elfcpp::Sym<size, big_endian> sym(p);
762       elfcpp::Sym<size, big_endian>* psym = &sym;
763
764       unsigned int st_name = psym->get_st_name();
765       if (st_name >= sym_name_size)
766         {
767           relobj->error(_("bad global symbol name offset %u at %zu"),
768                         st_name, i);
769           continue;
770         }
771
772       const char* name = sym_names + st_name;
773
774       // A symbol defined in a section which we are not including must
775       // be treated as an undefined symbol.
776       unsigned char symbuf[sym_size];
777       elfcpp::Sym<size, big_endian> sym2(symbuf);
778       unsigned int st_shndx = psym->get_st_shndx();
779       if (st_shndx != elfcpp::SHN_UNDEF
780           && st_shndx < elfcpp::SHN_LORESERVE
781           && !relobj->is_section_included(st_shndx))
782         {
783           memcpy(symbuf, p, sym_size);
784           elfcpp::Sym_write<size, big_endian> sw(symbuf);
785           sw.put_st_shndx(elfcpp::SHN_UNDEF);
786           psym = &sym2;
787         }
788
789       // In an object file, an '@' in the name separates the symbol
790       // name from the version name.  If there are two '@' characters,
791       // this is the default version.
792       const char* ver = strchr(name, '@');
793       int namelen = 0;
794       // DEF: is the version default?  LOCAL: is the symbol forced local?
795       bool def = false;
796       bool local = false;
797
798       if (ver != NULL)
799         {
800           // The symbol name is of the form foo@VERSION or foo@@VERSION
801           namelen = ver - name;
802           ++ver;
803           if (*ver == '@')
804             {
805               def = true;
806               ++ver;
807             }
808         }
809       // We don't want to assign a version to an undefined symbol,
810       // even if it is listed in the version script.  FIXME: What
811       // about a common symbol?
812       else if (!version_script_.empty()
813                && psym->get_st_shndx() != elfcpp::SHN_UNDEF)
814         {
815           // The symbol name did not have a version, but
816           // the version script may assign a version anyway.
817           namelen = strlen(name);
818           def = true;
819           // Check the global: entries from the version script.
820           const std::string& version =
821               version_script_.get_symbol_version(name);
822           if (!version.empty())
823             ver = version.c_str();
824           // Check the local: entries from the version script
825           if (version_script_.symbol_is_local(name))
826             local = true;
827         }
828
829       if (just_symbols)
830         {
831           if (psym != &sym2)
832             memcpy(symbuf, p, sym_size);
833           elfcpp::Sym_write<size, big_endian> sw(symbuf);
834           sw.put_st_shndx(elfcpp::SHN_ABS);
835           if (st_shndx != elfcpp::SHN_UNDEF
836               && st_shndx < elfcpp::SHN_LORESERVE)
837             {
838               // Symbol values in object files are section relative.
839               // This is normally what we want, but since here we are
840               // converting the symbol to absolute we need to add the
841               // section address.  The section address in an object
842               // file is normally zero, but people can use a linker
843               // script to change it.
844               sw.put_st_value(sym2.get_st_value()
845                               + relobj->section_address(st_shndx));
846             }
847           psym = &sym2;
848         }
849
850       Sized_symbol<size>* res;
851       if (ver == NULL)
852         {
853           Stringpool::Key name_key;
854           name = this->namepool_.add(name, true, &name_key);
855           res = this->add_from_object(relobj, name, name_key, NULL, 0,
856                                       false, *psym, sym);
857           if (local)
858             this->force_local(res);
859         }
860       else
861         {
862           Stringpool::Key name_key;
863           name = this->namepool_.add_with_length(name, namelen, true,
864                                                  &name_key);
865           Stringpool::Key ver_key;
866           ver = this->namepool_.add(ver, true, &ver_key);
867
868           res = this->add_from_object(relobj, name, name_key, ver, ver_key,
869                                       def, *psym, sym);
870         }
871
872       (*sympointers)[i] = res;
873     }
874 }
875
876 // Add all the symbols in a dynamic object to the hash table.
877
878 template<int size, bool big_endian>
879 void
880 Symbol_table::add_from_dynobj(
881     Sized_dynobj<size, big_endian>* dynobj,
882     const unsigned char* syms,
883     size_t count,
884     const char* sym_names,
885     size_t sym_name_size,
886     const unsigned char* versym,
887     size_t versym_size,
888     const std::vector<const char*>* version_map)
889 {
890   gold_assert(size == dynobj->target()->get_size());
891   gold_assert(size == parameters->target().get_size());
892
893   if (dynobj->just_symbols())
894     {
895       gold_error(_("--just-symbols does not make sense with a shared object"));
896       return;
897     }
898
899   if (versym != NULL && versym_size / 2 < count)
900     {
901       dynobj->error(_("too few symbol versions"));
902       return;
903     }
904
905   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
906
907   // We keep a list of all STT_OBJECT symbols, so that we can resolve
908   // weak aliases.  This is necessary because if the dynamic object
909   // provides the same variable under two names, one of which is a
910   // weak definition, and the regular object refers to the weak
911   // definition, we have to put both the weak definition and the
912   // strong definition into the dynamic symbol table.  Given a weak
913   // definition, the only way that we can find the corresponding
914   // strong definition, if any, is to search the symbol table.
915   std::vector<Sized_symbol<size>*> object_symbols;
916
917   const unsigned char* p = syms;
918   const unsigned char* vs = versym;
919   for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
920     {
921       elfcpp::Sym<size, big_endian> sym(p);
922
923       // Ignore symbols with local binding or that have
924       // internal or hidden visibility.
925       if (sym.get_st_bind() == elfcpp::STB_LOCAL
926           || sym.get_st_visibility() == elfcpp::STV_INTERNAL
927           || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
928         continue;
929
930       unsigned int st_name = sym.get_st_name();
931       if (st_name >= sym_name_size)
932         {
933           dynobj->error(_("bad symbol name offset %u at %zu"),
934                         st_name, i);
935           continue;
936         }
937
938       const char* name = sym_names + st_name;
939
940       Sized_symbol<size>* res;
941
942       if (versym == NULL)
943         {
944           Stringpool::Key name_key;
945           name = this->namepool_.add(name, true, &name_key);
946           res = this->add_from_object(dynobj, name, name_key, NULL, 0,
947                                       false, sym, sym);
948         }
949       else
950         {
951           // Read the version information.
952
953           unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
954
955           bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
956           v &= elfcpp::VERSYM_VERSION;
957
958           // The Sun documentation says that V can be VER_NDX_LOCAL,
959           // or VER_NDX_GLOBAL, or a version index.  The meaning of
960           // VER_NDX_LOCAL is defined as "Symbol has local scope."
961           // The old GNU linker will happily generate VER_NDX_LOCAL
962           // for an undefined symbol.  I don't know what the Sun
963           // linker will generate.
964
965           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
966               && sym.get_st_shndx() != elfcpp::SHN_UNDEF)
967             {
968               // This symbol should not be visible outside the object.
969               continue;
970             }
971
972           // At this point we are definitely going to add this symbol.
973           Stringpool::Key name_key;
974           name = this->namepool_.add(name, true, &name_key);
975
976           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
977               || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
978             {
979               // This symbol does not have a version.
980               res = this->add_from_object(dynobj, name, name_key, NULL, 0,
981                                           false, sym, sym);
982             }
983           else
984             {
985               if (v >= version_map->size())
986                 {
987                   dynobj->error(_("versym for symbol %zu out of range: %u"),
988                                 i, v);
989                   continue;
990                 }
991
992               const char* version = (*version_map)[v];
993               if (version == NULL)
994                 {
995                   dynobj->error(_("versym for symbol %zu has no name: %u"),
996                                 i, v);
997                   continue;
998                 }
999
1000               Stringpool::Key version_key;
1001               version = this->namepool_.add(version, true, &version_key);
1002
1003               // If this is an absolute symbol, and the version name
1004               // and symbol name are the same, then this is the
1005               // version definition symbol.  These symbols exist to
1006               // support using -u to pull in particular versions.  We
1007               // do not want to record a version for them.
1008               if (sym.get_st_shndx() == elfcpp::SHN_ABS
1009                   && name_key == version_key)
1010                 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1011                                             false, sym, sym);
1012               else
1013                 {
1014                   const bool def = (!hidden
1015                                     && (sym.get_st_shndx()
1016                                         != elfcpp::SHN_UNDEF));
1017                   res = this->add_from_object(dynobj, name, name_key, version,
1018                                               version_key, def, sym, sym);
1019                 }
1020             }
1021         }
1022
1023       // Note that it is possible that RES was overridden by an
1024       // earlier object, in which case it can't be aliased here.
1025       if (sym.get_st_shndx() != elfcpp::SHN_UNDEF
1026           && sym.get_st_type() == elfcpp::STT_OBJECT
1027           && res->source() == Symbol::FROM_OBJECT
1028           && res->object() == dynobj)
1029         object_symbols.push_back(res);
1030     }
1031
1032   this->record_weak_aliases(&object_symbols);
1033 }
1034
1035 // This is used to sort weak aliases.  We sort them first by section
1036 // index, then by offset, then by weak ahead of strong.
1037
1038 template<int size>
1039 class Weak_alias_sorter
1040 {
1041  public:
1042   bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1043 };
1044
1045 template<int size>
1046 bool
1047 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1048                                     const Sized_symbol<size>* s2) const
1049 {
1050   if (s1->shndx() != s2->shndx())
1051     return s1->shndx() < s2->shndx();
1052   if (s1->value() != s2->value())
1053     return s1->value() < s2->value();
1054   if (s1->binding() != s2->binding())
1055     {
1056       if (s1->binding() == elfcpp::STB_WEAK)
1057         return true;
1058       if (s2->binding() == elfcpp::STB_WEAK)
1059         return false;
1060     }
1061   return std::string(s1->name()) < std::string(s2->name());
1062 }
1063
1064 // SYMBOLS is a list of object symbols from a dynamic object.  Look
1065 // for any weak aliases, and record them so that if we add the weak
1066 // alias to the dynamic symbol table, we also add the corresponding
1067 // strong symbol.
1068
1069 template<int size>
1070 void
1071 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1072 {
1073   // Sort the vector by section index, then by offset, then by weak
1074   // ahead of strong.
1075   std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1076
1077   // Walk through the vector.  For each weak definition, record
1078   // aliases.
1079   for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1080          symbols->begin();
1081        p != symbols->end();
1082        ++p)
1083     {
1084       if ((*p)->binding() != elfcpp::STB_WEAK)
1085         continue;
1086
1087       // Build a circular list of weak aliases.  Each symbol points to
1088       // the next one in the circular list.
1089
1090       Sized_symbol<size>* from_sym = *p;
1091       typename std::vector<Sized_symbol<size>*>::const_iterator q;
1092       for (q = p + 1; q != symbols->end(); ++q)
1093         {
1094           if ((*q)->shndx() != from_sym->shndx()
1095               || (*q)->value() != from_sym->value())
1096             break;
1097
1098           this->weak_aliases_[from_sym] = *q;
1099           from_sym->set_has_alias();
1100           from_sym = *q;
1101         }
1102
1103       if (from_sym != *p)
1104         {
1105           this->weak_aliases_[from_sym] = *p;
1106           from_sym->set_has_alias();
1107         }
1108
1109       p = q - 1;
1110     }
1111 }
1112
1113 // Create and return a specially defined symbol.  If ONLY_IF_REF is
1114 // true, then only create the symbol if there is a reference to it.
1115 // If this does not return NULL, it sets *POLDSYM to the existing
1116 // symbol if there is one.  This canonicalizes *PNAME and *PVERSION.
1117
1118 template<int size, bool big_endian>
1119 Sized_symbol<size>*
1120 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1121                                     bool only_if_ref,
1122                                     Sized_symbol<size>** poldsym)
1123 {
1124   Symbol* oldsym;
1125   Sized_symbol<size>* sym;
1126   bool add_to_table = false;
1127   typename Symbol_table_type::iterator add_loc = this->table_.end();
1128
1129   // If the caller didn't give us a version, see if we get one from
1130   // the version script.
1131   if (*pversion == NULL)
1132     {
1133       const std::string& v(this->version_script_.get_symbol_version(*pname));
1134       if (!v.empty())
1135         *pversion = v.c_str();
1136     }
1137
1138   if (only_if_ref)
1139     {
1140       oldsym = this->lookup(*pname, *pversion);
1141       if (oldsym == NULL || !oldsym->is_undefined())
1142         return NULL;
1143
1144       *pname = oldsym->name();
1145       *pversion = oldsym->version();
1146     }
1147   else
1148     {
1149       // Canonicalize NAME and VERSION.
1150       Stringpool::Key name_key;
1151       *pname = this->namepool_.add(*pname, true, &name_key);
1152
1153       Stringpool::Key version_key = 0;
1154       if (*pversion != NULL)
1155         *pversion = this->namepool_.add(*pversion, true, &version_key);
1156
1157       Symbol* const snull = NULL;
1158       std::pair<typename Symbol_table_type::iterator, bool> ins =
1159         this->table_.insert(std::make_pair(std::make_pair(name_key,
1160                                                           version_key),
1161                                            snull));
1162
1163       if (!ins.second)
1164         {
1165           // We already have a symbol table entry for NAME/VERSION.
1166           oldsym = ins.first->second;
1167           gold_assert(oldsym != NULL);
1168         }
1169       else
1170         {
1171           // We haven't seen this symbol before.
1172           gold_assert(ins.first->second == NULL);
1173           add_to_table = true;
1174           add_loc = ins.first;
1175           oldsym = NULL;
1176         }
1177     }
1178
1179   const Target& target = parameters->target();
1180   if (!target.has_make_symbol())
1181     sym = new Sized_symbol<size>();
1182   else
1183     {
1184       gold_assert(target.get_size() == size);
1185       gold_assert(target.is_big_endian() ? big_endian : !big_endian);
1186       typedef Sized_target<size, big_endian> My_target;
1187       const My_target* sized_target =
1188           static_cast<const My_target*>(&target);
1189       sym = sized_target->make_symbol();
1190       if (sym == NULL)
1191         return NULL;
1192     }
1193
1194   if (add_to_table)
1195     add_loc->second = sym;
1196   else
1197     gold_assert(oldsym != NULL);
1198
1199   *poldsym = this->get_sized_symbol<size>(oldsym);
1200
1201   return sym;
1202 }
1203
1204 // Define a symbol based on an Output_data.
1205
1206 Symbol*
1207 Symbol_table::define_in_output_data(const char* name,
1208                                     const char* version,
1209                                     Output_data* od,
1210                                     uint64_t value,
1211                                     uint64_t symsize,
1212                                     elfcpp::STT type,
1213                                     elfcpp::STB binding,
1214                                     elfcpp::STV visibility,
1215                                     unsigned char nonvis,
1216                                     bool offset_is_from_end,
1217                                     bool only_if_ref)
1218 {
1219   if (parameters->target().get_size() == 32)
1220     {
1221 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1222       return this->do_define_in_output_data<32>(name, version, od,
1223                                                 value, symsize, type, binding,
1224                                                 visibility, nonvis,
1225                                                 offset_is_from_end,
1226                                                 only_if_ref);
1227 #else
1228       gold_unreachable();
1229 #endif
1230     }
1231   else if (parameters->target().get_size() == 64)
1232     {
1233 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1234       return this->do_define_in_output_data<64>(name, version, od,
1235                                                 value, symsize, type, binding,
1236                                                 visibility, nonvis,
1237                                                 offset_is_from_end,
1238                                                 only_if_ref);
1239 #else
1240       gold_unreachable();
1241 #endif
1242     }
1243   else
1244     gold_unreachable();
1245 }
1246
1247 // Define a symbol in an Output_data, sized version.
1248
1249 template<int size>
1250 Sized_symbol<size>*
1251 Symbol_table::do_define_in_output_data(
1252     const char* name,
1253     const char* version,
1254     Output_data* od,
1255     typename elfcpp::Elf_types<size>::Elf_Addr value,
1256     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1257     elfcpp::STT type,
1258     elfcpp::STB binding,
1259     elfcpp::STV visibility,
1260     unsigned char nonvis,
1261     bool offset_is_from_end,
1262     bool only_if_ref)
1263 {
1264   Sized_symbol<size>* sym;
1265   Sized_symbol<size>* oldsym;
1266
1267   if (parameters->target().is_big_endian())
1268     {
1269 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1270       sym = this->define_special_symbol<size, true>(&name, &version,
1271                                                     only_if_ref, &oldsym);
1272 #else
1273       gold_unreachable();
1274 #endif
1275     }
1276   else
1277     {
1278 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1279       sym = this->define_special_symbol<size, false>(&name, &version,
1280                                                      only_if_ref, &oldsym);
1281 #else
1282       gold_unreachable();
1283 #endif
1284     }
1285
1286   if (sym == NULL)
1287     return NULL;
1288
1289   gold_assert(version == NULL || oldsym != NULL);
1290   sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1291             offset_is_from_end);
1292
1293   if (oldsym == NULL)
1294     {
1295       if (binding == elfcpp::STB_LOCAL
1296           || this->version_script_.symbol_is_local(name))
1297         this->force_local(sym);
1298       return sym;
1299     }
1300
1301   if (Symbol_table::should_override_with_special(oldsym))
1302     this->override_with_special(oldsym, sym);
1303   delete sym;
1304   return oldsym;
1305 }
1306
1307 // Define a symbol based on an Output_segment.
1308
1309 Symbol*
1310 Symbol_table::define_in_output_segment(const char* name,
1311                                        const char* version, Output_segment* os,
1312                                        uint64_t value,
1313                                        uint64_t symsize,
1314                                        elfcpp::STT type,
1315                                        elfcpp::STB binding,
1316                                        elfcpp::STV visibility,
1317                                        unsigned char nonvis,
1318                                        Symbol::Segment_offset_base offset_base,
1319                                        bool only_if_ref)
1320 {
1321   if (parameters->target().get_size() == 32)
1322     {
1323 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1324       return this->do_define_in_output_segment<32>(name, version, os,
1325                                                    value, symsize, type,
1326                                                    binding, visibility, nonvis,
1327                                                    offset_base, only_if_ref);
1328 #else
1329       gold_unreachable();
1330 #endif
1331     }
1332   else if (parameters->target().get_size() == 64)
1333     {
1334 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1335       return this->do_define_in_output_segment<64>(name, version, os,
1336                                                    value, symsize, type,
1337                                                    binding, visibility, nonvis,
1338                                                    offset_base, only_if_ref);
1339 #else
1340       gold_unreachable();
1341 #endif
1342     }
1343   else
1344     gold_unreachable();
1345 }
1346
1347 // Define a symbol in an Output_segment, sized version.
1348
1349 template<int size>
1350 Sized_symbol<size>*
1351 Symbol_table::do_define_in_output_segment(
1352     const char* name,
1353     const char* version,
1354     Output_segment* os,
1355     typename elfcpp::Elf_types<size>::Elf_Addr value,
1356     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1357     elfcpp::STT type,
1358     elfcpp::STB binding,
1359     elfcpp::STV visibility,
1360     unsigned char nonvis,
1361     Symbol::Segment_offset_base offset_base,
1362     bool only_if_ref)
1363 {
1364   Sized_symbol<size>* sym;
1365   Sized_symbol<size>* oldsym;
1366
1367   if (parameters->target().is_big_endian())
1368     {
1369 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1370       sym = this->define_special_symbol<size, true>(&name, &version,
1371                                                     only_if_ref, &oldsym);
1372 #else
1373       gold_unreachable();
1374 #endif
1375     }
1376   else
1377     {
1378 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1379       sym = this->define_special_symbol<size, false>(&name, &version,
1380                                                      only_if_ref, &oldsym);
1381 #else
1382       gold_unreachable();
1383 #endif
1384     }
1385
1386   if (sym == NULL)
1387     return NULL;
1388
1389   gold_assert(version == NULL || oldsym != NULL);
1390   sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1391             offset_base);
1392
1393   if (oldsym == NULL)
1394     {
1395       if (binding == elfcpp::STB_LOCAL
1396           || this->version_script_.symbol_is_local(name))
1397         this->force_local(sym);
1398       return sym;
1399     }
1400
1401   if (Symbol_table::should_override_with_special(oldsym))
1402     this->override_with_special(oldsym, sym);
1403   delete sym;
1404   return oldsym;
1405 }
1406
1407 // Define a special symbol with a constant value.  It is a multiple
1408 // definition error if this symbol is already defined.
1409
1410 Symbol*
1411 Symbol_table::define_as_constant(const char* name,
1412                                  const char* version,
1413                                  uint64_t value,
1414                                  uint64_t symsize,
1415                                  elfcpp::STT type,
1416                                  elfcpp::STB binding,
1417                                  elfcpp::STV visibility,
1418                                  unsigned char nonvis,
1419                                  bool only_if_ref,
1420                                  bool force_override)
1421 {
1422   if (parameters->target().get_size() == 32)
1423     {
1424 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1425       return this->do_define_as_constant<32>(name, version, value,
1426                                              symsize, type, binding,
1427                                              visibility, nonvis, only_if_ref,
1428                                              force_override);
1429 #else
1430       gold_unreachable();
1431 #endif
1432     }
1433   else if (parameters->target().get_size() == 64)
1434     {
1435 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1436       return this->do_define_as_constant<64>(name, version, value,
1437                                              symsize, type, binding,
1438                                              visibility, nonvis, only_if_ref,
1439                                              force_override);
1440 #else
1441       gold_unreachable();
1442 #endif
1443     }
1444   else
1445     gold_unreachable();
1446 }
1447
1448 // Define a symbol as a constant, sized version.
1449
1450 template<int size>
1451 Sized_symbol<size>*
1452 Symbol_table::do_define_as_constant(
1453     const char* name,
1454     const char* version,
1455     typename elfcpp::Elf_types<size>::Elf_Addr value,
1456     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1457     elfcpp::STT type,
1458     elfcpp::STB binding,
1459     elfcpp::STV visibility,
1460     unsigned char nonvis,
1461     bool only_if_ref,
1462     bool force_override)
1463 {
1464   Sized_symbol<size>* sym;
1465   Sized_symbol<size>* oldsym;
1466
1467   if (parameters->target().is_big_endian())
1468     {
1469 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1470       sym = this->define_special_symbol<size, true>(&name, &version,
1471                                                     only_if_ref, &oldsym);
1472 #else
1473       gold_unreachable();
1474 #endif
1475     }
1476   else
1477     {
1478 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1479       sym = this->define_special_symbol<size, false>(&name, &version,
1480                                                      only_if_ref, &oldsym);
1481 #else
1482       gold_unreachable();
1483 #endif
1484     }
1485
1486   if (sym == NULL)
1487     return NULL;
1488
1489   gold_assert(version == NULL || version == name || oldsym != NULL);
1490   sym->init(name, value, symsize, type, binding, visibility, nonvis);
1491
1492   if (oldsym == NULL)
1493     {
1494       // Version symbols are absolute symbols with name == version.
1495       // We don't want to force them to be local.
1496       if ((version == NULL
1497            || name != version
1498            || value != 0)
1499           && (binding == elfcpp::STB_LOCAL
1500               || this->version_script_.symbol_is_local(name)))
1501         this->force_local(sym);
1502       return sym;
1503     }
1504
1505   if (force_override || Symbol_table::should_override_with_special(oldsym))
1506     this->override_with_special(oldsym, sym);
1507   delete sym;
1508   return oldsym;
1509 }
1510
1511 // Define a set of symbols in output sections.
1512
1513 void
1514 Symbol_table::define_symbols(const Layout* layout, int count,
1515                              const Define_symbol_in_section* p,
1516                              bool only_if_ref)
1517 {
1518   for (int i = 0; i < count; ++i, ++p)
1519     {
1520       Output_section* os = layout->find_output_section(p->output_section);
1521       if (os != NULL)
1522         this->define_in_output_data(p->name, NULL, os, p->value,
1523                                     p->size, p->type, p->binding,
1524                                     p->visibility, p->nonvis,
1525                                     p->offset_is_from_end,
1526                                     only_if_ref || p->only_if_ref);
1527       else
1528         this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1529                                  p->binding, p->visibility, p->nonvis,
1530                                  only_if_ref || p->only_if_ref,
1531                                  false);
1532     }
1533 }
1534
1535 // Define a set of symbols in output segments.
1536
1537 void
1538 Symbol_table::define_symbols(const Layout* layout, int count,
1539                              const Define_symbol_in_segment* p,
1540                              bool only_if_ref)
1541 {
1542   for (int i = 0; i < count; ++i, ++p)
1543     {
1544       Output_segment* os = layout->find_output_segment(p->segment_type,
1545                                                        p->segment_flags_set,
1546                                                        p->segment_flags_clear);
1547       if (os != NULL)
1548         this->define_in_output_segment(p->name, NULL, os, p->value,
1549                                        p->size, p->type, p->binding,
1550                                        p->visibility, p->nonvis,
1551                                        p->offset_base,
1552                                        only_if_ref || p->only_if_ref);
1553       else
1554         this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1555                                  p->binding, p->visibility, p->nonvis,
1556                                  only_if_ref || p->only_if_ref,
1557                                  false);
1558     }
1559 }
1560
1561 // Define CSYM using a COPY reloc.  POSD is the Output_data where the
1562 // symbol should be defined--typically a .dyn.bss section.  VALUE is
1563 // the offset within POSD.
1564
1565 template<int size>
1566 void
1567 Symbol_table::define_with_copy_reloc(
1568     Sized_symbol<size>* csym,
1569     Output_data* posd,
1570     typename elfcpp::Elf_types<size>::Elf_Addr value)
1571 {
1572   gold_assert(csym->is_from_dynobj());
1573   gold_assert(!csym->is_copied_from_dynobj());
1574   Object* object = csym->object();
1575   gold_assert(object->is_dynamic());
1576   Dynobj* dynobj = static_cast<Dynobj*>(object);
1577
1578   // Our copied variable has to override any variable in a shared
1579   // library.
1580   elfcpp::STB binding = csym->binding();
1581   if (binding == elfcpp::STB_WEAK)
1582     binding = elfcpp::STB_GLOBAL;
1583
1584   this->define_in_output_data(csym->name(), csym->version(),
1585                               posd, value, csym->symsize(),
1586                               csym->type(), binding,
1587                               csym->visibility(), csym->nonvis(),
1588                               false, false);
1589
1590   csym->set_is_copied_from_dynobj();
1591   csym->set_needs_dynsym_entry();
1592
1593   this->copied_symbol_dynobjs_[csym] = dynobj;
1594
1595   // We have now defined all aliases, but we have not entered them all
1596   // in the copied_symbol_dynobjs_ map.
1597   if (csym->has_alias())
1598     {
1599       Symbol* sym = csym;
1600       while (true)
1601         {
1602           sym = this->weak_aliases_[sym];
1603           if (sym == csym)
1604             break;
1605           gold_assert(sym->output_data() == posd);
1606
1607           sym->set_is_copied_from_dynobj();
1608           this->copied_symbol_dynobjs_[sym] = dynobj;
1609         }
1610     }
1611 }
1612
1613 // SYM is defined using a COPY reloc.  Return the dynamic object where
1614 // the original definition was found.
1615
1616 Dynobj*
1617 Symbol_table::get_copy_source(const Symbol* sym) const
1618 {
1619   gold_assert(sym->is_copied_from_dynobj());
1620   Copied_symbol_dynobjs::const_iterator p =
1621     this->copied_symbol_dynobjs_.find(sym);
1622   gold_assert(p != this->copied_symbol_dynobjs_.end());
1623   return p->second;
1624 }
1625
1626 // Set the dynamic symbol indexes.  INDEX is the index of the first
1627 // global dynamic symbol.  Pointers to the symbols are stored into the
1628 // vector SYMS.  The names are added to DYNPOOL.  This returns an
1629 // updated dynamic symbol index.
1630
1631 unsigned int
1632 Symbol_table::set_dynsym_indexes(unsigned int index,
1633                                  std::vector<Symbol*>* syms,
1634                                  Stringpool* dynpool,
1635                                  Versions* versions)
1636 {
1637   for (Symbol_table_type::iterator p = this->table_.begin();
1638        p != this->table_.end();
1639        ++p)
1640     {
1641       Symbol* sym = p->second;
1642
1643       // Note that SYM may already have a dynamic symbol index, since
1644       // some symbols appear more than once in the symbol table, with
1645       // and without a version.
1646
1647       if (!sym->should_add_dynsym_entry())
1648         sym->set_dynsym_index(-1U);
1649       else if (!sym->has_dynsym_index())
1650         {
1651           sym->set_dynsym_index(index);
1652           ++index;
1653           syms->push_back(sym);
1654           dynpool->add(sym->name(), false, NULL);
1655
1656           // Record any version information.
1657           if (sym->version() != NULL)
1658             versions->record_version(this, dynpool, sym);
1659         }
1660     }
1661
1662   // Finish up the versions.  In some cases this may add new dynamic
1663   // symbols.
1664   index = versions->finalize(this, index, syms);
1665
1666   return index;
1667 }
1668
1669 // Set the final values for all the symbols.  The index of the first
1670 // global symbol in the output file is *PLOCAL_SYMCOUNT.  Record the
1671 // file offset OFF.  Add their names to POOL.  Return the new file
1672 // offset.  Update *PLOCAL_SYMCOUNT if necessary.
1673
1674 off_t
1675 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
1676                        size_t dyncount, Stringpool* pool,
1677                        unsigned int *plocal_symcount)
1678 {
1679   off_t ret;
1680
1681   gold_assert(*plocal_symcount != 0);
1682   this->first_global_index_ = *plocal_symcount;
1683
1684   this->dynamic_offset_ = dynoff;
1685   this->first_dynamic_global_index_ = dyn_global_index;
1686   this->dynamic_count_ = dyncount;
1687
1688   if (parameters->target().get_size() == 32)
1689     {
1690 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1691       ret = this->sized_finalize<32>(off, pool, plocal_symcount);
1692 #else
1693       gold_unreachable();
1694 #endif
1695     }
1696   else if (parameters->target().get_size() == 64)
1697     {
1698 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1699       ret = this->sized_finalize<64>(off, pool, plocal_symcount);
1700 #else
1701       gold_unreachable();
1702 #endif
1703     }
1704   else
1705     gold_unreachable();
1706
1707   // Now that we have the final symbol table, we can reliably note
1708   // which symbols should get warnings.
1709   this->warnings_.note_warnings(this);
1710
1711   return ret;
1712 }
1713
1714 // SYM is going into the symbol table at *PINDEX.  Add the name to
1715 // POOL, update *PINDEX and *POFF.
1716
1717 template<int size>
1718 void
1719 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
1720                                   unsigned int* pindex, off_t* poff)
1721 {
1722   sym->set_symtab_index(*pindex);
1723   pool->add(sym->name(), false, NULL);
1724   ++*pindex;
1725   *poff += elfcpp::Elf_sizes<size>::sym_size;
1726 }
1727
1728 // Set the final value for all the symbols.  This is called after
1729 // Layout::finalize, so all the output sections have their final
1730 // address.
1731
1732 template<int size>
1733 off_t
1734 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
1735                              unsigned int* plocal_symcount)
1736 {
1737   off = align_address(off, size >> 3);
1738   this->offset_ = off;
1739
1740   unsigned int index = *plocal_symcount;
1741   const unsigned int orig_index = index;
1742
1743   // First do all the symbols which have been forced to be local, as
1744   // they must appear before all global symbols.
1745   for (Forced_locals::iterator p = this->forced_locals_.begin();
1746        p != this->forced_locals_.end();
1747        ++p)
1748     {
1749       Symbol* sym = *p;
1750       gold_assert(sym->is_forced_local());
1751       if (this->sized_finalize_symbol<size>(sym))
1752         {
1753           this->add_to_final_symtab<size>(sym, pool, &index, &off);
1754           ++*plocal_symcount;
1755         }
1756     }
1757
1758   // Now do all the remaining symbols.
1759   for (Symbol_table_type::iterator p = this->table_.begin();
1760        p != this->table_.end();
1761        ++p)
1762     {
1763       Symbol* sym = p->second;
1764       if (this->sized_finalize_symbol<size>(sym))
1765         this->add_to_final_symtab<size>(sym, pool, &index, &off);
1766     }
1767
1768   this->output_count_ = index - orig_index;
1769
1770   return off;
1771 }
1772
1773 // Finalize the symbol SYM.  This returns true if the symbol should be
1774 // added to the symbol table, false otherwise.
1775
1776 template<int size>
1777 bool
1778 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
1779 {
1780   Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
1781
1782   // The default version of a symbol may appear twice in the symbol
1783   // table.  We only need to finalize it once.
1784   if (sym->has_symtab_index())
1785     return false;
1786
1787   if (!sym->in_reg())
1788     {
1789       gold_assert(!sym->has_symtab_index());
1790       sym->set_symtab_index(-1U);
1791       gold_assert(sym->dynsym_index() == -1U);
1792       return false;
1793     }
1794
1795   typename Sized_symbol<size>::Value_type value;
1796
1797   switch (sym->source())
1798     {
1799     case Symbol::FROM_OBJECT:
1800       {
1801         unsigned int shndx = sym->shndx();
1802
1803         // FIXME: We need some target specific support here.
1804         if (shndx >= elfcpp::SHN_LORESERVE
1805             && shndx != elfcpp::SHN_ABS
1806             && shndx != elfcpp::SHN_COMMON)
1807           {
1808             gold_error(_("%s: unsupported symbol section 0x%x"),
1809                        sym->demangled_name().c_str(), shndx);
1810             shndx = elfcpp::SHN_UNDEF;
1811           }
1812
1813         Object* symobj = sym->object();
1814         if (symobj->is_dynamic())
1815           {
1816             value = 0;
1817             shndx = elfcpp::SHN_UNDEF;
1818           }
1819         else if (shndx == elfcpp::SHN_UNDEF)
1820           value = 0;
1821         else if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
1822           value = sym->value();
1823         else
1824           {
1825             Relobj* relobj = static_cast<Relobj*>(symobj);
1826             section_offset_type secoff;
1827             Output_section* os = relobj->output_section(shndx, &secoff);
1828
1829             if (os == NULL)
1830               {
1831                 sym->set_symtab_index(-1U);
1832                 gold_assert(sym->dynsym_index() == -1U);
1833                 return false;
1834               }
1835
1836             if (sym->type() == elfcpp::STT_TLS)
1837               value = sym->value() + os->tls_offset() + secoff;
1838             else
1839               value = sym->value() + os->address() + secoff;
1840           }
1841       }
1842       break;
1843
1844     case Symbol::IN_OUTPUT_DATA:
1845       {
1846         Output_data* od = sym->output_data();
1847         value = sym->value();
1848         if (sym->type() != elfcpp::STT_TLS)
1849           value += od->address();
1850         else
1851           {
1852             Output_section* os = od->output_section();
1853             gold_assert(os != NULL);
1854             value += os->tls_offset() + (od->address() - os->address());
1855           }
1856         if (sym->offset_is_from_end())
1857           value += od->data_size();
1858       }
1859       break;
1860
1861     case Symbol::IN_OUTPUT_SEGMENT:
1862       {
1863         Output_segment* os = sym->output_segment();
1864         value = sym->value();
1865         if (sym->type() != elfcpp::STT_TLS)
1866           value += os->vaddr();
1867         switch (sym->offset_base())
1868           {
1869           case Symbol::SEGMENT_START:
1870             break;
1871           case Symbol::SEGMENT_END:
1872             value += os->memsz();
1873             break;
1874           case Symbol::SEGMENT_BSS:
1875             value += os->filesz();
1876             break;
1877           default:
1878             gold_unreachable();
1879           }
1880       }
1881       break;
1882
1883     case Symbol::CONSTANT:
1884       value = sym->value();
1885       break;
1886
1887     default:
1888       gold_unreachable();
1889     }
1890
1891   sym->set_value(value);
1892
1893   if (parameters->options().strip_all())
1894     {
1895       sym->set_symtab_index(-1U);
1896       return false;
1897     }
1898
1899   return true;
1900 }
1901
1902 // Write out the global symbols.
1903
1904 void
1905 Symbol_table::write_globals(const Input_objects* input_objects,
1906                             const Stringpool* sympool,
1907                             const Stringpool* dynpool, Output_file* of) const
1908 {
1909   switch (parameters->size_and_endianness())
1910     {
1911 #ifdef HAVE_TARGET_32_LITTLE
1912     case Parameters::TARGET_32_LITTLE:
1913       this->sized_write_globals<32, false>(input_objects, sympool,
1914                                            dynpool, of);
1915       break;
1916 #endif
1917 #ifdef HAVE_TARGET_32_BIG
1918     case Parameters::TARGET_32_BIG:
1919       this->sized_write_globals<32, true>(input_objects, sympool,
1920                                           dynpool, of);
1921       break;
1922 #endif
1923 #ifdef HAVE_TARGET_64_LITTLE
1924     case Parameters::TARGET_64_LITTLE:
1925       this->sized_write_globals<64, false>(input_objects, sympool,
1926                                            dynpool, of);
1927       break;
1928 #endif
1929 #ifdef HAVE_TARGET_64_BIG
1930     case Parameters::TARGET_64_BIG:
1931       this->sized_write_globals<64, true>(input_objects, sympool,
1932                                           dynpool, of);
1933       break;
1934 #endif
1935     default:
1936       gold_unreachable();
1937     }
1938 }
1939
1940 // Write out the global symbols.
1941
1942 template<int size, bool big_endian>
1943 void
1944 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1945                                   const Stringpool* sympool,
1946                                   const Stringpool* dynpool,
1947                                   Output_file* of) const
1948 {
1949   const Target& target = parameters->target();
1950
1951   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1952
1953   const unsigned int output_count = this->output_count_;
1954   const section_size_type oview_size = output_count * sym_size;
1955   const unsigned int first_global_index = this->first_global_index_;
1956   unsigned char* psyms;
1957   if (this->offset_ == 0 || output_count == 0)
1958     psyms = NULL;
1959   else
1960     psyms = of->get_output_view(this->offset_, oview_size);
1961
1962   const unsigned int dynamic_count = this->dynamic_count_;
1963   const section_size_type dynamic_size = dynamic_count * sym_size;
1964   const unsigned int first_dynamic_global_index =
1965     this->first_dynamic_global_index_;
1966   unsigned char* dynamic_view;
1967   if (this->dynamic_offset_ == 0 || dynamic_count == 0)
1968     dynamic_view = NULL;
1969   else
1970     dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
1971
1972   for (Symbol_table_type::const_iterator p = this->table_.begin();
1973        p != this->table_.end();
1974        ++p)
1975     {
1976       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
1977
1978       // Possibly warn about unresolved symbols in shared libraries.
1979       this->warn_about_undefined_dynobj_symbol(input_objects, sym);
1980
1981       unsigned int sym_index = sym->symtab_index();
1982       unsigned int dynsym_index;
1983       if (dynamic_view == NULL)
1984         dynsym_index = -1U;
1985       else
1986         dynsym_index = sym->dynsym_index();
1987
1988       if (sym_index == -1U && dynsym_index == -1U)
1989         {
1990           // This symbol is not included in the output file.
1991           continue;
1992         }
1993
1994       unsigned int shndx;
1995       typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
1996       typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
1997       switch (sym->source())
1998         {
1999         case Symbol::FROM_OBJECT:
2000           {
2001             unsigned int in_shndx = sym->shndx();
2002
2003             // FIXME: We need some target specific support here.
2004             if (in_shndx >= elfcpp::SHN_LORESERVE
2005                 && in_shndx != elfcpp::SHN_ABS
2006                 && in_shndx != elfcpp::SHN_COMMON)
2007               {
2008                 gold_error(_("%s: unsupported symbol section 0x%x"),
2009                            sym->demangled_name().c_str(), in_shndx);
2010                 shndx = in_shndx;
2011               }
2012             else
2013               {
2014                 Object* symobj = sym->object();
2015                 if (symobj->is_dynamic())
2016                   {
2017                     if (sym->needs_dynsym_value())
2018                       dynsym_value = target.dynsym_value(sym);
2019                     shndx = elfcpp::SHN_UNDEF;
2020                   }
2021                 else if (in_shndx == elfcpp::SHN_UNDEF
2022                          || in_shndx == elfcpp::SHN_ABS
2023                          || in_shndx == elfcpp::SHN_COMMON)
2024                   shndx = in_shndx;
2025                 else
2026                   {
2027                     Relobj* relobj = static_cast<Relobj*>(symobj);
2028                     section_offset_type secoff;
2029                     Output_section* os = relobj->output_section(in_shndx,
2030                                                                 &secoff);
2031                     gold_assert(os != NULL);
2032                     shndx = os->out_shndx();
2033
2034                     // In object files symbol values are section
2035                     // relative.
2036                     if (parameters->options().relocatable())
2037                       sym_value -= os->address();
2038                   }
2039               }
2040           }
2041           break;
2042
2043         case Symbol::IN_OUTPUT_DATA:
2044           shndx = sym->output_data()->out_shndx();
2045           break;
2046
2047         case Symbol::IN_OUTPUT_SEGMENT:
2048           shndx = elfcpp::SHN_ABS;
2049           break;
2050
2051         case Symbol::CONSTANT:
2052           shndx = elfcpp::SHN_ABS;
2053           break;
2054
2055         default:
2056           gold_unreachable();
2057         }
2058
2059       if (sym_index != -1U)
2060         {
2061           sym_index -= first_global_index;
2062           gold_assert(sym_index < output_count);
2063           unsigned char* ps = psyms + (sym_index * sym_size);
2064           this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2065                                                      sympool, ps);
2066         }
2067
2068       if (dynsym_index != -1U)
2069         {
2070           dynsym_index -= first_dynamic_global_index;
2071           gold_assert(dynsym_index < dynamic_count);
2072           unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2073           this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2074                                                      dynpool, pd);
2075         }
2076     }
2077
2078   of->write_output_view(this->offset_, oview_size, psyms);
2079   if (dynamic_view != NULL)
2080     of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2081 }
2082
2083 // Write out the symbol SYM, in section SHNDX, to P.  POOL is the
2084 // strtab holding the name.
2085
2086 template<int size, bool big_endian>
2087 void
2088 Symbol_table::sized_write_symbol(
2089     Sized_symbol<size>* sym,
2090     typename elfcpp::Elf_types<size>::Elf_Addr value,
2091     unsigned int shndx,
2092     const Stringpool* pool,
2093     unsigned char* p) const
2094 {
2095   elfcpp::Sym_write<size, big_endian> osym(p);
2096   osym.put_st_name(pool->get_offset(sym->name()));
2097   osym.put_st_value(value);
2098   osym.put_st_size(sym->symsize());
2099   // A version script may have overridden the default binding.
2100   if (sym->is_forced_local())
2101     osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2102   else
2103     osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2104   osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2105   osym.put_st_shndx(shndx);
2106 }
2107
2108 // Check for unresolved symbols in shared libraries.  This is
2109 // controlled by the --allow-shlib-undefined option.
2110
2111 // We only warn about libraries for which we have seen all the
2112 // DT_NEEDED entries.  We don't try to track down DT_NEEDED entries
2113 // which were not seen in this link.  If we didn't see a DT_NEEDED
2114 // entry, we aren't going to be able to reliably report whether the
2115 // symbol is undefined.
2116
2117 // We also don't warn about libraries found in the system library
2118 // directory (the directory were we find libc.so); we assume that
2119 // those libraries are OK.  This heuristic avoids problems in
2120 // GNU/Linux, in which -ldl can have undefined references satisfied by
2121 // ld-linux.so.
2122
2123 inline void
2124 Symbol_table::warn_about_undefined_dynobj_symbol(
2125     const Input_objects* input_objects,
2126     Symbol* sym) const
2127 {
2128   if (sym->source() == Symbol::FROM_OBJECT
2129       && sym->object()->is_dynamic()
2130       && sym->shndx() == elfcpp::SHN_UNDEF
2131       && sym->binding() != elfcpp::STB_WEAK
2132       && !parameters->options().allow_shlib_undefined()
2133       && !parameters->target().is_defined_by_abi(sym)
2134       && !input_objects->found_in_system_library_directory(sym->object()))
2135     {
2136       // A very ugly cast.
2137       Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2138       if (!dynobj->has_unknown_needed_entries())
2139         gold_error(_("%s: undefined reference to '%s'"),
2140                    sym->object()->name().c_str(),
2141                    sym->demangled_name().c_str());
2142     }
2143 }
2144
2145 // Write out a section symbol.  Return the update offset.
2146
2147 void
2148 Symbol_table::write_section_symbol(const Output_section *os,
2149                                    Output_file* of,
2150                                    off_t offset) const
2151 {
2152   switch (parameters->size_and_endianness())
2153     {
2154 #ifdef HAVE_TARGET_32_LITTLE
2155     case Parameters::TARGET_32_LITTLE:
2156       this->sized_write_section_symbol<32, false>(os, of, offset);
2157       break;
2158 #endif
2159 #ifdef HAVE_TARGET_32_BIG
2160     case Parameters::TARGET_32_BIG:
2161       this->sized_write_section_symbol<32, true>(os, of, offset);
2162       break;
2163 #endif
2164 #ifdef HAVE_TARGET_64_LITTLE
2165     case Parameters::TARGET_64_LITTLE:
2166       this->sized_write_section_symbol<64, false>(os, of, offset);
2167       break;
2168 #endif
2169 #ifdef HAVE_TARGET_64_BIG
2170     case Parameters::TARGET_64_BIG:
2171       this->sized_write_section_symbol<64, true>(os, of, offset);
2172       break;
2173 #endif
2174     default:
2175       gold_unreachable();
2176     }
2177 }
2178
2179 // Write out a section symbol, specialized for size and endianness.
2180
2181 template<int size, bool big_endian>
2182 void
2183 Symbol_table::sized_write_section_symbol(const Output_section* os,
2184                                          Output_file* of,
2185                                          off_t offset) const
2186 {
2187   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2188
2189   unsigned char* pov = of->get_output_view(offset, sym_size);
2190
2191   elfcpp::Sym_write<size, big_endian> osym(pov);
2192   osym.put_st_name(0);
2193   osym.put_st_value(os->address());
2194   osym.put_st_size(0);
2195   osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2196                                        elfcpp::STT_SECTION));
2197   osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2198   osym.put_st_shndx(os->out_shndx());
2199
2200   of->write_output_view(offset, sym_size, pov);
2201 }
2202
2203 // Print statistical information to stderr.  This is used for --stats.
2204
2205 void
2206 Symbol_table::print_stats() const
2207 {
2208 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2209   fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2210           program_name, this->table_.size(), this->table_.bucket_count());
2211 #else
2212   fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2213           program_name, this->table_.size());
2214 #endif
2215   this->namepool_.print_stats("symbol table stringpool");
2216 }
2217
2218 // We check for ODR violations by looking for symbols with the same
2219 // name for which the debugging information reports that they were
2220 // defined in different source locations.  When comparing the source
2221 // location, we consider instances with the same base filename and
2222 // line number to be the same.  This is because different object
2223 // files/shared libraries can include the same header file using
2224 // different paths, and we don't want to report an ODR violation in
2225 // that case.
2226
2227 // This struct is used to compare line information, as returned by
2228 // Dwarf_line_info::one_addr2line.  It implements a < comparison
2229 // operator used with std::set.
2230
2231 struct Odr_violation_compare
2232 {
2233   bool
2234   operator()(const std::string& s1, const std::string& s2) const
2235   {
2236     std::string::size_type pos1 = s1.rfind('/');
2237     std::string::size_type pos2 = s2.rfind('/');
2238     if (pos1 == std::string::npos
2239         || pos2 == std::string::npos)
2240       return s1 < s2;
2241     return s1.compare(pos1, std::string::npos,
2242                       s2, pos2, std::string::npos) < 0;
2243   }
2244 };
2245
2246 // Check candidate_odr_violations_ to find symbols with the same name
2247 // but apparently different definitions (different source-file/line-no).
2248
2249 void
2250 Symbol_table::detect_odr_violations(const Task* task,
2251                                     const char* output_file_name) const
2252 {
2253   for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2254        it != candidate_odr_violations_.end();
2255        ++it)
2256     {
2257       const char* symbol_name = it->first;
2258       // We use a sorted set so the output is deterministic.
2259       std::set<std::string, Odr_violation_compare> line_nums;
2260
2261       for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2262                locs = it->second.begin();
2263            locs != it->second.end();
2264            ++locs)
2265         {
2266           // We need to lock the object in order to read it.  This
2267           // means that we have to run in a singleton Task.  If we
2268           // want to run this in a general Task for better
2269           // performance, we will need one Task for object, plus
2270           // appropriate locking to ensure that we don't conflict with
2271           // other uses of the object.
2272           Task_lock_obj<Object> tl(task, locs->object);
2273           std::string lineno = Dwarf_line_info::one_addr2line(
2274               locs->object, locs->shndx, locs->offset);
2275           if (!lineno.empty())
2276             line_nums.insert(lineno);
2277         }
2278
2279       if (line_nums.size() > 1)
2280         {
2281           gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2282                          "places (possible ODR violation):"),
2283                        output_file_name, demangle(symbol_name).c_str());
2284           for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2285                it2 != line_nums.end();
2286                ++it2)
2287             fprintf(stderr, "  %s\n", it2->c_str());
2288         }
2289     }
2290 }
2291
2292 // Warnings functions.
2293
2294 // Add a new warning.
2295
2296 void
2297 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2298                       const std::string& warning)
2299 {
2300   name = symtab->canonicalize_name(name);
2301   this->warnings_[name].set(obj, warning);
2302 }
2303
2304 // Look through the warnings and mark the symbols for which we should
2305 // warn.  This is called during Layout::finalize when we know the
2306 // sources for all the symbols.
2307
2308 void
2309 Warnings::note_warnings(Symbol_table* symtab)
2310 {
2311   for (Warning_table::iterator p = this->warnings_.begin();
2312        p != this->warnings_.end();
2313        ++p)
2314     {
2315       Symbol* sym = symtab->lookup(p->first, NULL);
2316       if (sym != NULL
2317           && sym->source() == Symbol::FROM_OBJECT
2318           && sym->object() == p->second.object)
2319         sym->set_has_warning();
2320     }
2321 }
2322
2323 // Issue a warning.  This is called when we see a relocation against a
2324 // symbol for which has a warning.
2325
2326 template<int size, bool big_endian>
2327 void
2328 Warnings::issue_warning(const Symbol* sym,
2329                         const Relocate_info<size, big_endian>* relinfo,
2330                         size_t relnum, off_t reloffset) const
2331 {
2332   gold_assert(sym->has_warning());
2333   Warning_table::const_iterator p = this->warnings_.find(sym->name());
2334   gold_assert(p != this->warnings_.end());
2335   gold_warning_at_location(relinfo, relnum, reloffset,
2336                            "%s", p->second.text.c_str());
2337 }
2338
2339 // Instantiate the templates we need.  We could use the configure
2340 // script to restrict this to only the ones needed for implemented
2341 // targets.
2342
2343 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2344 template
2345 void
2346 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2347 #endif
2348
2349 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2350 template
2351 void
2352 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2353 #endif
2354
2355 #ifdef HAVE_TARGET_32_LITTLE
2356 template
2357 void
2358 Symbol_table::add_from_relobj<32, false>(
2359     Sized_relobj<32, false>* relobj,
2360     const unsigned char* syms,
2361     size_t count,
2362     const char* sym_names,
2363     size_t sym_name_size,
2364     Sized_relobj<32, true>::Symbols* sympointers);
2365 #endif
2366
2367 #ifdef HAVE_TARGET_32_BIG
2368 template
2369 void
2370 Symbol_table::add_from_relobj<32, true>(
2371     Sized_relobj<32, true>* relobj,
2372     const unsigned char* syms,
2373     size_t count,
2374     const char* sym_names,
2375     size_t sym_name_size,
2376     Sized_relobj<32, false>::Symbols* sympointers);
2377 #endif
2378
2379 #ifdef HAVE_TARGET_64_LITTLE
2380 template
2381 void
2382 Symbol_table::add_from_relobj<64, false>(
2383     Sized_relobj<64, false>* relobj,
2384     const unsigned char* syms,
2385     size_t count,
2386     const char* sym_names,
2387     size_t sym_name_size,
2388     Sized_relobj<64, true>::Symbols* sympointers);
2389 #endif
2390
2391 #ifdef HAVE_TARGET_64_BIG
2392 template
2393 void
2394 Symbol_table::add_from_relobj<64, true>(
2395     Sized_relobj<64, true>* relobj,
2396     const unsigned char* syms,
2397     size_t count,
2398     const char* sym_names,
2399     size_t sym_name_size,
2400     Sized_relobj<64, false>::Symbols* sympointers);
2401 #endif
2402
2403 #ifdef HAVE_TARGET_32_LITTLE
2404 template
2405 void
2406 Symbol_table::add_from_dynobj<32, false>(
2407     Sized_dynobj<32, false>* dynobj,
2408     const unsigned char* syms,
2409     size_t count,
2410     const char* sym_names,
2411     size_t sym_name_size,
2412     const unsigned char* versym,
2413     size_t versym_size,
2414     const std::vector<const char*>* version_map);
2415 #endif
2416
2417 #ifdef HAVE_TARGET_32_BIG
2418 template
2419 void
2420 Symbol_table::add_from_dynobj<32, true>(
2421     Sized_dynobj<32, true>* dynobj,
2422     const unsigned char* syms,
2423     size_t count,
2424     const char* sym_names,
2425     size_t sym_name_size,
2426     const unsigned char* versym,
2427     size_t versym_size,
2428     const std::vector<const char*>* version_map);
2429 #endif
2430
2431 #ifdef HAVE_TARGET_64_LITTLE
2432 template
2433 void
2434 Symbol_table::add_from_dynobj<64, false>(
2435     Sized_dynobj<64, false>* dynobj,
2436     const unsigned char* syms,
2437     size_t count,
2438     const char* sym_names,
2439     size_t sym_name_size,
2440     const unsigned char* versym,
2441     size_t versym_size,
2442     const std::vector<const char*>* version_map);
2443 #endif
2444
2445 #ifdef HAVE_TARGET_64_BIG
2446 template
2447 void
2448 Symbol_table::add_from_dynobj<64, true>(
2449     Sized_dynobj<64, true>* dynobj,
2450     const unsigned char* syms,
2451     size_t count,
2452     const char* sym_names,
2453     size_t sym_name_size,
2454     const unsigned char* versym,
2455     size_t versym_size,
2456     const std::vector<const char*>* version_map);
2457 #endif
2458
2459 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2460 template
2461 void
2462 Symbol_table::define_with_copy_reloc<32>(
2463     Sized_symbol<32>* sym,
2464     Output_data* posd,
2465     elfcpp::Elf_types<32>::Elf_Addr value);
2466 #endif
2467
2468 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2469 template
2470 void
2471 Symbol_table::define_with_copy_reloc<64>(
2472     Sized_symbol<64>* sym,
2473     Output_data* posd,
2474     elfcpp::Elf_types<64>::Elf_Addr value);
2475 #endif
2476
2477 #ifdef HAVE_TARGET_32_LITTLE
2478 template
2479 void
2480 Warnings::issue_warning<32, false>(const Symbol* sym,
2481                                    const Relocate_info<32, false>* relinfo,
2482                                    size_t relnum, off_t reloffset) const;
2483 #endif
2484
2485 #ifdef HAVE_TARGET_32_BIG
2486 template
2487 void
2488 Warnings::issue_warning<32, true>(const Symbol* sym,
2489                                   const Relocate_info<32, true>* relinfo,
2490                                   size_t relnum, off_t reloffset) const;
2491 #endif
2492
2493 #ifdef HAVE_TARGET_64_LITTLE
2494 template
2495 void
2496 Warnings::issue_warning<64, false>(const Symbol* sym,
2497                                    const Relocate_info<64, false>* relinfo,
2498                                    size_t relnum, off_t reloffset) const;
2499 #endif
2500
2501 #ifdef HAVE_TARGET_64_BIG
2502 template
2503 void
2504 Warnings::issue_warning<64, true>(const Symbol* sym,
2505                                   const Relocate_info<64, true>* relinfo,
2506                                   size_t relnum, off_t reloffset) const;
2507 #endif
2508
2509 } // End namespace gold.