* object.cc (Xindex::initialize_symtab_xindex): 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   this->is_ordinary_shndx_ = false;
76 }
77
78 // Return the demangled version of the symbol's name, but only
79 // if the --demangle flag was set.
80
81 static std::string
82 demangle(const char* name)
83 {
84   if (!parameters->options().do_demangle())
85     return name;
86
87   // cplus_demangle allocates memory for the result it returns,
88   // and returns NULL if the name is already demangled.
89   char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
90   if (demangled_name == NULL)
91     return name;
92
93   std::string retval(demangled_name);
94   free(demangled_name);
95   return retval;
96 }
97
98 std::string
99 Symbol::demangled_name() const
100 {
101   return demangle(this->name());
102 }
103
104 // Initialize the fields in the base class Symbol for SYM in OBJECT.
105
106 template<int size, bool big_endian>
107 void
108 Symbol::init_base(const char* name, const char* version, Object* object,
109                   const elfcpp::Sym<size, big_endian>& sym,
110                   unsigned int st_shndx, bool is_ordinary)
111 {
112   this->init_fields(name, version, sym.get_st_type(), sym.get_st_bind(),
113                     sym.get_st_visibility(), sym.get_st_nonvis());
114   this->u_.from_object.object = object;
115   this->u_.from_object.shndx = st_shndx;
116   this->is_ordinary_shndx_ = is_ordinary;
117   this->source_ = FROM_OBJECT;
118   this->in_reg_ = !object->is_dynamic();
119   this->in_dyn_ = object->is_dynamic();
120 }
121
122 // Initialize the fields in the base class Symbol for a symbol defined
123 // in an Output_data.
124
125 void
126 Symbol::init_base(const char* name, Output_data* od, elfcpp::STT type,
127                   elfcpp::STB binding, elfcpp::STV visibility,
128                   unsigned char nonvis, bool offset_is_from_end)
129 {
130   this->init_fields(name, NULL, type, binding, visibility, nonvis);
131   this->u_.in_output_data.output_data = od;
132   this->u_.in_output_data.offset_is_from_end = offset_is_from_end;
133   this->source_ = IN_OUTPUT_DATA;
134   this->in_reg_ = true;
135 }
136
137 // Initialize the fields in the base class Symbol for a symbol defined
138 // in an Output_segment.
139
140 void
141 Symbol::init_base(const char* name, Output_segment* os, elfcpp::STT type,
142                   elfcpp::STB binding, elfcpp::STV visibility,
143                   unsigned char nonvis, Segment_offset_base offset_base)
144 {
145   this->init_fields(name, NULL, type, binding, visibility, nonvis);
146   this->u_.in_output_segment.output_segment = os;
147   this->u_.in_output_segment.offset_base = offset_base;
148   this->source_ = IN_OUTPUT_SEGMENT;
149   this->in_reg_ = true;
150 }
151
152 // Initialize the fields in the base class Symbol for a symbol defined
153 // as a constant.
154
155 void
156 Symbol::init_base(const char* name, elfcpp::STT type,
157                   elfcpp::STB binding, elfcpp::STV visibility,
158                   unsigned char nonvis)
159 {
160   this->init_fields(name, NULL, type, binding, visibility, nonvis);
161   this->source_ = CONSTANT;
162   this->in_reg_ = true;
163 }
164
165 // Allocate a common symbol in the base.
166
167 void
168 Symbol::allocate_base_common(Output_data* od)
169 {
170   gold_assert(this->is_common());
171   this->source_ = IN_OUTPUT_DATA;
172   this->u_.in_output_data.output_data = od;
173   this->u_.in_output_data.offset_is_from_end = false;
174 }
175
176 // Initialize the fields in Sized_symbol for SYM in OBJECT.
177
178 template<int size>
179 template<bool big_endian>
180 void
181 Sized_symbol<size>::init(const char* name, const char* version, Object* object,
182                          const elfcpp::Sym<size, big_endian>& sym,
183                          unsigned int st_shndx, bool is_ordinary)
184 {
185   this->init_base(name, version, object, sym, st_shndx, is_ordinary);
186   this->value_ = sym.get_st_value();
187   this->symsize_ = sym.get_st_size();
188 }
189
190 // Initialize the fields in Sized_symbol for a symbol defined in an
191 // Output_data.
192
193 template<int size>
194 void
195 Sized_symbol<size>::init(const char* name, Output_data* od,
196                          Value_type value, Size_type symsize,
197                          elfcpp::STT type, elfcpp::STB binding,
198                          elfcpp::STV visibility, unsigned char nonvis,
199                          bool offset_is_from_end)
200 {
201   this->init_base(name, od, type, binding, visibility, nonvis,
202                   offset_is_from_end);
203   this->value_ = value;
204   this->symsize_ = symsize;
205 }
206
207 // Initialize the fields in Sized_symbol for a symbol defined in an
208 // Output_segment.
209
210 template<int size>
211 void
212 Sized_symbol<size>::init(const char* name, Output_segment* os,
213                          Value_type value, Size_type symsize,
214                          elfcpp::STT type, elfcpp::STB binding,
215                          elfcpp::STV visibility, unsigned char nonvis,
216                          Segment_offset_base offset_base)
217 {
218   this->init_base(name, os, type, binding, visibility, nonvis, offset_base);
219   this->value_ = value;
220   this->symsize_ = symsize;
221 }
222
223 // Initialize the fields in Sized_symbol for a symbol defined as a
224 // constant.
225
226 template<int size>
227 void
228 Sized_symbol<size>::init(const char* name, Value_type value, Size_type symsize,
229                          elfcpp::STT type, elfcpp::STB binding,
230                          elfcpp::STV visibility, unsigned char nonvis)
231 {
232   this->init_base(name, type, binding, visibility, nonvis);
233   this->value_ = value;
234   this->symsize_ = symsize;
235 }
236
237 // Allocate a common symbol.
238
239 template<int size>
240 void
241 Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
242 {
243   this->allocate_base_common(od);
244   this->value_ = value;
245 }
246
247 // Return true if this symbol should be added to the dynamic symbol
248 // table.
249
250 inline bool
251 Symbol::should_add_dynsym_entry() const
252 {
253   // If the symbol is used by a dynamic relocation, we need to add it.
254   if (this->needs_dynsym_entry())
255     return true;
256
257   // If the symbol was forced local in a version script, do not add it.
258   if (this->is_forced_local())
259     return false;
260
261   // If exporting all symbols or building a shared library,
262   // and the symbol is defined in a regular object and is
263   // externally visible, we need to add it.
264   if ((parameters->options().export_dynamic() || parameters->options().shared())
265       && !this->is_from_dynobj()
266       && this->is_externally_visible())
267     return true;
268
269   return false;
270 }
271
272 // Return true if the final value of this symbol is known at link
273 // time.
274
275 bool
276 Symbol::final_value_is_known() const
277 {
278   // If we are not generating an executable, then no final values are
279   // known, since they will change at runtime.
280   if (parameters->options().shared() || parameters->options().relocatable())
281     return false;
282
283   // If the symbol is not from an object file, then it is defined, and
284   // known.
285   if (this->source_ != FROM_OBJECT)
286     return true;
287
288   // If the symbol is from a dynamic object, then the final value is
289   // not known.
290   if (this->object()->is_dynamic())
291     return false;
292
293   // If the symbol is not undefined (it is defined or common), then
294   // the final value is known.
295   if (!this->is_undefined())
296     return true;
297
298   // If the symbol is undefined, then whether the final value is known
299   // depends on whether we are doing a static link.  If we are doing a
300   // dynamic link, then the final value could be filled in at runtime.
301   // This could reasonably be the case for a weak undefined symbol.
302   return parameters->doing_static_link();
303 }
304
305 // Return the output section where this symbol is defined.
306
307 Output_section*
308 Symbol::output_section() const
309 {
310   switch (this->source_)
311     {
312     case FROM_OBJECT:
313       {
314         unsigned int shndx = this->u_.from_object.shndx;
315         if (shndx != elfcpp::SHN_UNDEF && this->is_ordinary_shndx_)
316           {
317             gold_assert(!this->u_.from_object.object->is_dynamic());
318             Relobj* relobj = static_cast<Relobj*>(this->u_.from_object.object);
319             section_offset_type dummy;
320             return relobj->output_section(shndx, &dummy);
321           }
322         return NULL;
323       }
324
325     case IN_OUTPUT_DATA:
326       return this->u_.in_output_data.output_data->output_section();
327
328     case IN_OUTPUT_SEGMENT:
329     case CONSTANT:
330       return NULL;
331
332     default:
333       gold_unreachable();
334     }
335 }
336
337 // Set the symbol's output section.  This is used for symbols defined
338 // in scripts.  This should only be called after the symbol table has
339 // been finalized.
340
341 void
342 Symbol::set_output_section(Output_section* os)
343 {
344   switch (this->source_)
345     {
346     case FROM_OBJECT:
347     case IN_OUTPUT_DATA:
348       gold_assert(this->output_section() == os);
349       break;
350     case CONSTANT:
351       this->source_ = IN_OUTPUT_DATA;
352       this->u_.in_output_data.output_data = os;
353       this->u_.in_output_data.offset_is_from_end = false;
354       break;
355     case IN_OUTPUT_SEGMENT:
356     default:
357       gold_unreachable();
358     }
359 }
360
361 // Class Symbol_table.
362
363 Symbol_table::Symbol_table(unsigned int count,
364                            const Version_script_info& version_script)
365   : saw_undefined_(0), offset_(0), table_(count), namepool_(),
366     forwarders_(), commons_(), tls_commons_(), forced_locals_(), warnings_(),
367     version_script_(version_script)
368 {
369   namepool_.reserve(count);
370 }
371
372 Symbol_table::~Symbol_table()
373 {
374 }
375
376 // The hash function.  The key values are Stringpool keys.
377
378 inline size_t
379 Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
380 {
381   return key.first ^ key.second;
382 }
383
384 // The symbol table key equality function.  This is called with
385 // Stringpool keys.
386
387 inline bool
388 Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
389                                           const Symbol_table_key& k2) const
390 {
391   return k1.first == k2.first && k1.second == k2.second;
392 }
393
394 // Make TO a symbol which forwards to FROM.
395
396 void
397 Symbol_table::make_forwarder(Symbol* from, Symbol* to)
398 {
399   gold_assert(from != to);
400   gold_assert(!from->is_forwarder() && !to->is_forwarder());
401   this->forwarders_[from] = to;
402   from->set_forwarder();
403 }
404
405 // Resolve the forwards from FROM, returning the real symbol.
406
407 Symbol*
408 Symbol_table::resolve_forwards(const Symbol* from) const
409 {
410   gold_assert(from->is_forwarder());
411   Unordered_map<const Symbol*, Symbol*>::const_iterator p =
412     this->forwarders_.find(from);
413   gold_assert(p != this->forwarders_.end());
414   return p->second;
415 }
416
417 // Look up a symbol by name.
418
419 Symbol*
420 Symbol_table::lookup(const char* name, const char* version) const
421 {
422   Stringpool::Key name_key;
423   name = this->namepool_.find(name, &name_key);
424   if (name == NULL)
425     return NULL;
426
427   Stringpool::Key version_key = 0;
428   if (version != NULL)
429     {
430       version = this->namepool_.find(version, &version_key);
431       if (version == NULL)
432         return NULL;
433     }
434
435   Symbol_table_key key(name_key, version_key);
436   Symbol_table::Symbol_table_type::const_iterator p = this->table_.find(key);
437   if (p == this->table_.end())
438     return NULL;
439   return p->second;
440 }
441
442 // Resolve a Symbol with another Symbol.  This is only used in the
443 // unusual case where there are references to both an unversioned
444 // symbol and a symbol with a version, and we then discover that that
445 // version is the default version.  Because this is unusual, we do
446 // this the slow way, by converting back to an ELF symbol.
447
448 template<int size, bool big_endian>
449 void
450 Symbol_table::resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
451                       const char* version)
452 {
453   unsigned char buf[elfcpp::Elf_sizes<size>::sym_size];
454   elfcpp::Sym_write<size, big_endian> esym(buf);
455   // We don't bother to set the st_name or the st_shndx field.
456   esym.put_st_value(from->value());
457   esym.put_st_size(from->symsize());
458   esym.put_st_info(from->binding(), from->type());
459   esym.put_st_other(from->visibility(), from->nonvis());
460   bool is_ordinary;
461   unsigned int shndx = from->shndx(&is_ordinary);
462   this->resolve(to, esym.sym(), shndx, is_ordinary, shndx, from->object(),
463                 version);
464   if (from->in_reg())
465     to->set_in_reg();
466   if (from->in_dyn())
467     to->set_in_dyn();
468 }
469
470 // Record that a symbol is forced to be local by a version script.
471
472 void
473 Symbol_table::force_local(Symbol* sym)
474 {
475   if (!sym->is_defined() && !sym->is_common())
476     return;
477   if (sym->is_forced_local())
478     {
479       // We already got this one.
480       return;
481     }
482   sym->set_is_forced_local();
483   this->forced_locals_.push_back(sym);
484 }
485
486 // Adjust NAME for wrapping, and update *NAME_KEY if necessary.  This
487 // is only called for undefined symbols, when at least one --wrap
488 // option was used.
489
490 const char*
491 Symbol_table::wrap_symbol(Object* object, const char* name,
492                           Stringpool::Key* name_key)
493 {
494   // For some targets, we need to ignore a specific character when
495   // wrapping, and add it back later.
496   char prefix = '\0';
497   if (name[0] == object->target()->wrap_char())
498     {
499       prefix = name[0];
500       ++name;
501     }
502
503   if (parameters->options().is_wrap(name))
504     {
505       // Turn NAME into __wrap_NAME.
506       std::string s;
507       if (prefix != '\0')
508         s += prefix;
509       s += "__wrap_";
510       s += name;
511
512       // This will give us both the old and new name in NAMEPOOL_, but
513       // that is OK.  Only the versions we need will wind up in the
514       // real string table in the output file.
515       return this->namepool_.add(s.c_str(), true, name_key);
516     }
517
518   const char* const real_prefix = "__real_";
519   const size_t real_prefix_length = strlen(real_prefix);
520   if (strncmp(name, real_prefix, real_prefix_length) == 0
521       && parameters->options().is_wrap(name + real_prefix_length))
522     {
523       // Turn __real_NAME into NAME.
524       std::string s;
525       if (prefix != '\0')
526         s += prefix;
527       s += name + real_prefix_length;
528       return this->namepool_.add(s.c_str(), true, name_key);
529     }
530
531   return name;
532 }
533
534 // Add one symbol from OBJECT to the symbol table.  NAME is symbol
535 // name and VERSION is the version; both are canonicalized.  DEF is
536 // whether this is the default version.  ST_SHNDX is the symbol's
537 // section index; IS_ORDINARY is whether this is a normal section
538 // rather than a special code.
539
540 // If DEF is true, then this is the definition of a default version of
541 // a symbol.  That means that any lookup of NAME/NULL and any lookup
542 // of NAME/VERSION should always return the same symbol.  This is
543 // obvious for references, but in particular we want to do this for
544 // definitions: overriding NAME/NULL should also override
545 // NAME/VERSION.  If we don't do that, it would be very hard to
546 // override functions in a shared library which uses versioning.
547
548 // We implement this by simply making both entries in the hash table
549 // point to the same Symbol structure.  That is easy enough if this is
550 // the first time we see NAME/NULL or NAME/VERSION, but it is possible
551 // that we have seen both already, in which case they will both have
552 // independent entries in the symbol table.  We can't simply change
553 // the symbol table entry, because we have pointers to the entries
554 // attached to the object files.  So we mark the entry attached to the
555 // object file as a forwarder, and record it in the forwarders_ map.
556 // Note that entries in the hash table will never be marked as
557 // forwarders.
558 //
559 // ORIG_ST_SHNDX and ST_SHNDX are almost always the same.
560 // ORIG_ST_SHNDX is the section index in the input file, or SHN_UNDEF
561 // for a special section code.  ST_SHNDX may be modified if the symbol
562 // is defined in a section being discarded.
563
564 template<int size, bool big_endian>
565 Sized_symbol<size>*
566 Symbol_table::add_from_object(Object* object,
567                               const char *name,
568                               Stringpool::Key name_key,
569                               const char *version,
570                               Stringpool::Key version_key,
571                               bool def,
572                               const elfcpp::Sym<size, big_endian>& sym,
573                               unsigned int st_shndx,
574                               bool is_ordinary,
575                               unsigned int orig_st_shndx)
576 {
577   // Print a message if this symbol is being traced.
578   if (parameters->options().is_trace_symbol(name))
579     {
580       if (orig_st_shndx == elfcpp::SHN_UNDEF)
581         gold_info(_("%s: reference to %s"), object->name().c_str(), name);
582       else
583         gold_info(_("%s: definition of %s"), object->name().c_str(), name);
584     }
585
586   // For an undefined symbol, we may need to adjust the name using
587   // --wrap.
588   if (orig_st_shndx == elfcpp::SHN_UNDEF
589       && parameters->options().any_wrap())
590     {
591       const char* wrap_name = this->wrap_symbol(object, name, &name_key);
592       if (wrap_name != name)
593         {
594           // If we see a reference to malloc with version GLIBC_2.0,
595           // and we turn it into a reference to __wrap_malloc, then we
596           // discard the version number.  Otherwise the user would be
597           // required to specify the correct version for
598           // __wrap_malloc.
599           version = NULL;
600           version_key = 0;
601           name = wrap_name;
602         }
603     }
604
605   Symbol* const snull = NULL;
606   std::pair<typename Symbol_table_type::iterator, bool> ins =
607     this->table_.insert(std::make_pair(std::make_pair(name_key, version_key),
608                                        snull));
609
610   std::pair<typename Symbol_table_type::iterator, bool> insdef =
611     std::make_pair(this->table_.end(), false);
612   if (def)
613     {
614       const Stringpool::Key vnull_key = 0;
615       insdef = this->table_.insert(std::make_pair(std::make_pair(name_key,
616                                                                  vnull_key),
617                                                   snull));
618     }
619
620   // ins.first: an iterator, which is a pointer to a pair.
621   // ins.first->first: the key (a pair of name and version).
622   // ins.first->second: the value (Symbol*).
623   // ins.second: true if new entry was inserted, false if not.
624
625   Sized_symbol<size>* ret;
626   bool was_undefined;
627   bool was_common;
628   if (!ins.second)
629     {
630       // We already have an entry for NAME/VERSION.
631       ret = this->get_sized_symbol<size>(ins.first->second);
632       gold_assert(ret != NULL);
633
634       was_undefined = ret->is_undefined();
635       was_common = ret->is_common();
636
637       this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
638                     version);
639
640       if (def)
641         {
642           if (insdef.second)
643             {
644               // This is the first time we have seen NAME/NULL.  Make
645               // NAME/NULL point to NAME/VERSION.
646               insdef.first->second = ret;
647             }
648           else if (insdef.first->second != ret
649                    && insdef.first->second->is_undefined())
650             {
651               // This is the unfortunate case where we already have
652               // entries for both NAME/VERSION and NAME/NULL.  Note
653               // that we don't want to combine them if the existing
654               // symbol is going to override the new one.  FIXME: We
655               // currently just test is_undefined, but this may not do
656               // the right thing if the existing symbol is from a
657               // shared library and the new one is from a regular
658               // object.
659
660               const Sized_symbol<size>* sym2;
661               sym2 = this->get_sized_symbol<size>(insdef.first->second);
662               Symbol_table::resolve<size, big_endian>(ret, sym2, version);
663               this->make_forwarder(insdef.first->second, ret);
664               insdef.first->second = ret;
665             }
666           else
667             def = false;
668         }
669     }
670   else
671     {
672       // This is the first time we have seen NAME/VERSION.
673       gold_assert(ins.first->second == NULL);
674
675       if (def && !insdef.second)
676         {
677           // We already have an entry for NAME/NULL.  If we override
678           // it, then change it to NAME/VERSION.
679           ret = this->get_sized_symbol<size>(insdef.first->second);
680
681           was_undefined = ret->is_undefined();
682           was_common = ret->is_common();
683
684           this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
685                         version);
686           ins.first->second = ret;
687         }
688       else
689         {
690           was_undefined = false;
691           was_common = false;
692
693           Sized_target<size, big_endian>* target =
694             object->sized_target<size, big_endian>();
695           if (!target->has_make_symbol())
696             ret = new Sized_symbol<size>();
697           else
698             {
699               ret = target->make_symbol();
700               if (ret == NULL)
701                 {
702                   // This means that we don't want a symbol table
703                   // entry after all.
704                   if (!def)
705                     this->table_.erase(ins.first);
706                   else
707                     {
708                       this->table_.erase(insdef.first);
709                       // Inserting insdef invalidated ins.
710                       this->table_.erase(std::make_pair(name_key,
711                                                         version_key));
712                     }
713                   return NULL;
714                 }
715             }
716
717           ret->init(name, version, object, sym, st_shndx, is_ordinary);
718
719           ins.first->second = ret;
720           if (def)
721             {
722               // This is the first time we have seen NAME/NULL.  Point
723               // it at the new entry for NAME/VERSION.
724               gold_assert(insdef.second);
725               insdef.first->second = ret;
726             }
727         }
728     }
729
730   // Record every time we see a new undefined symbol, to speed up
731   // archive groups.
732   if (!was_undefined && ret->is_undefined())
733     ++this->saw_undefined_;
734
735   // Keep track of common symbols, to speed up common symbol
736   // allocation.
737   if (!was_common && ret->is_common())
738     {
739       if (ret->type() != elfcpp::STT_TLS)
740         this->commons_.push_back(ret);
741       else
742         this->tls_commons_.push_back(ret);
743     }
744
745   if (def)
746     ret->set_is_default();
747   return ret;
748 }
749
750 // Add all the symbols in a relocatable object to the hash table.
751
752 template<int size, bool big_endian>
753 void
754 Symbol_table::add_from_relobj(
755     Sized_relobj<size, big_endian>* relobj,
756     const unsigned char* syms,
757     size_t count,
758     size_t symndx_offset,
759     const char* sym_names,
760     size_t sym_name_size,
761     typename Sized_relobj<size, big_endian>::Symbols* sympointers)
762 {
763   gold_assert(size == relobj->target()->get_size());
764   gold_assert(size == parameters->target().get_size());
765
766   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
767
768   const bool just_symbols = relobj->just_symbols();
769
770   const unsigned char* p = syms;
771   for (size_t i = 0; i < count; ++i, p += sym_size)
772     {
773       elfcpp::Sym<size, big_endian> sym(p);
774
775       unsigned int st_name = sym.get_st_name();
776       if (st_name >= sym_name_size)
777         {
778           relobj->error(_("bad global symbol name offset %u at %zu"),
779                         st_name, i);
780           continue;
781         }
782
783       const char* name = sym_names + st_name;
784
785       bool is_ordinary;
786       unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
787                                                        sym.get_st_shndx(),
788                                                        &is_ordinary);
789       unsigned int orig_st_shndx = st_shndx;
790       if (!is_ordinary)
791         orig_st_shndx = elfcpp::SHN_UNDEF;
792
793       // A symbol defined in a section which we are not including must
794       // be treated as an undefined symbol.
795       if (st_shndx != elfcpp::SHN_UNDEF
796           && is_ordinary
797           && !relobj->is_section_included(st_shndx))
798         st_shndx = elfcpp::SHN_UNDEF;
799
800       // In an object file, an '@' in the name separates the symbol
801       // name from the version name.  If there are two '@' characters,
802       // this is the default version.
803       const char* ver = strchr(name, '@');
804       int namelen = 0;
805       // DEF: is the version default?  LOCAL: is the symbol forced local?
806       bool def = false;
807       bool local = false;
808
809       if (ver != NULL)
810         {
811           // The symbol name is of the form foo@VERSION or foo@@VERSION
812           namelen = ver - name;
813           ++ver;
814           if (*ver == '@')
815             {
816               def = true;
817               ++ver;
818             }
819         }
820       // We don't want to assign a version to an undefined symbol,
821       // even if it is listed in the version script.  FIXME: What
822       // about a common symbol?
823       else if (!version_script_.empty()
824                && st_shndx != elfcpp::SHN_UNDEF)
825         {
826           // The symbol name did not have a version, but
827           // the version script may assign a version anyway.
828           namelen = strlen(name);
829           def = true;
830           // Check the global: entries from the version script.
831           const std::string& version =
832               version_script_.get_symbol_version(name);
833           if (!version.empty())
834             ver = version.c_str();
835           // Check the local: entries from the version script
836           if (version_script_.symbol_is_local(name))
837             local = true;
838         }
839
840       elfcpp::Sym<size, big_endian>* psym = &sym;
841       unsigned char symbuf[sym_size];
842       elfcpp::Sym<size, big_endian> sym2(symbuf);
843       if (just_symbols)
844         {
845           memcpy(symbuf, p, sym_size);
846           elfcpp::Sym_write<size, big_endian> sw(symbuf);
847           if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
848             {
849               // Symbol values in object files are section relative.
850               // This is normally what we want, but since here we are
851               // converting the symbol to absolute we need to add the
852               // section address.  The section address in an object
853               // file is normally zero, but people can use a linker
854               // script to change it.
855               sw.put_st_value(sym.get_st_value()
856                               + relobj->section_address(orig_st_shndx));
857             }
858           st_shndx = elfcpp::SHN_ABS;
859           is_ordinary = false;
860           psym = &sym2;
861         }
862
863       Sized_symbol<size>* res;
864       if (ver == NULL)
865         {
866           Stringpool::Key name_key;
867           name = this->namepool_.add(name, true, &name_key);
868           res = this->add_from_object(relobj, name, name_key, NULL, 0,
869                                       false, *psym, st_shndx, is_ordinary,
870                                       orig_st_shndx);
871           if (local)
872             this->force_local(res);
873         }
874       else
875         {
876           Stringpool::Key name_key;
877           name = this->namepool_.add_with_length(name, namelen, true,
878                                                  &name_key);
879           Stringpool::Key ver_key;
880           ver = this->namepool_.add(ver, true, &ver_key);
881
882           res = this->add_from_object(relobj, name, name_key, ver, ver_key,
883                                       def, *psym, st_shndx, is_ordinary,
884                                       orig_st_shndx);
885         }
886
887       (*sympointers)[i] = res;
888     }
889 }
890
891 // Add all the symbols in a dynamic object to the hash table.
892
893 template<int size, bool big_endian>
894 void
895 Symbol_table::add_from_dynobj(
896     Sized_dynobj<size, big_endian>* dynobj,
897     const unsigned char* syms,
898     size_t count,
899     const char* sym_names,
900     size_t sym_name_size,
901     const unsigned char* versym,
902     size_t versym_size,
903     const std::vector<const char*>* version_map)
904 {
905   gold_assert(size == dynobj->target()->get_size());
906   gold_assert(size == parameters->target().get_size());
907
908   if (dynobj->just_symbols())
909     {
910       gold_error(_("--just-symbols does not make sense with a shared object"));
911       return;
912     }
913
914   if (versym != NULL && versym_size / 2 < count)
915     {
916       dynobj->error(_("too few symbol versions"));
917       return;
918     }
919
920   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
921
922   // We keep a list of all STT_OBJECT symbols, so that we can resolve
923   // weak aliases.  This is necessary because if the dynamic object
924   // provides the same variable under two names, one of which is a
925   // weak definition, and the regular object refers to the weak
926   // definition, we have to put both the weak definition and the
927   // strong definition into the dynamic symbol table.  Given a weak
928   // definition, the only way that we can find the corresponding
929   // strong definition, if any, is to search the symbol table.
930   std::vector<Sized_symbol<size>*> object_symbols;
931
932   const unsigned char* p = syms;
933   const unsigned char* vs = versym;
934   for (size_t i = 0; i < count; ++i, p += sym_size, vs += 2)
935     {
936       elfcpp::Sym<size, big_endian> sym(p);
937
938       // Ignore symbols with local binding or that have
939       // internal or hidden visibility.
940       if (sym.get_st_bind() == elfcpp::STB_LOCAL
941           || sym.get_st_visibility() == elfcpp::STV_INTERNAL
942           || sym.get_st_visibility() == elfcpp::STV_HIDDEN)
943         continue;
944
945       unsigned int st_name = sym.get_st_name();
946       if (st_name >= sym_name_size)
947         {
948           dynobj->error(_("bad symbol name offset %u at %zu"),
949                         st_name, i);
950           continue;
951         }
952
953       const char* name = sym_names + st_name;
954
955       bool is_ordinary;
956       unsigned int st_shndx = dynobj->adjust_sym_shndx(i, sym.get_st_shndx(),
957                                                        &is_ordinary);
958
959       Sized_symbol<size>* res;
960
961       if (versym == NULL)
962         {
963           Stringpool::Key name_key;
964           name = this->namepool_.add(name, true, &name_key);
965           res = this->add_from_object(dynobj, name, name_key, NULL, 0,
966                                       false, sym, st_shndx, is_ordinary,
967                                       st_shndx);
968         }
969       else
970         {
971           // Read the version information.
972
973           unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
974
975           bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
976           v &= elfcpp::VERSYM_VERSION;
977
978           // The Sun documentation says that V can be VER_NDX_LOCAL,
979           // or VER_NDX_GLOBAL, or a version index.  The meaning of
980           // VER_NDX_LOCAL is defined as "Symbol has local scope."
981           // The old GNU linker will happily generate VER_NDX_LOCAL
982           // for an undefined symbol.  I don't know what the Sun
983           // linker will generate.
984
985           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
986               && st_shndx != elfcpp::SHN_UNDEF)
987             {
988               // This symbol should not be visible outside the object.
989               continue;
990             }
991
992           // At this point we are definitely going to add this symbol.
993           Stringpool::Key name_key;
994           name = this->namepool_.add(name, true, &name_key);
995
996           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
997               || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
998             {
999               // This symbol does not have a version.
1000               res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1001                                           false, sym, st_shndx, is_ordinary,
1002                                           st_shndx);
1003             }
1004           else
1005             {
1006               if (v >= version_map->size())
1007                 {
1008                   dynobj->error(_("versym for symbol %zu out of range: %u"),
1009                                 i, v);
1010                   continue;
1011                 }
1012
1013               const char* version = (*version_map)[v];
1014               if (version == NULL)
1015                 {
1016                   dynobj->error(_("versym for symbol %zu has no name: %u"),
1017                                 i, v);
1018                   continue;
1019                 }
1020
1021               Stringpool::Key version_key;
1022               version = this->namepool_.add(version, true, &version_key);
1023
1024               // If this is an absolute symbol, and the version name
1025               // and symbol name are the same, then this is the
1026               // version definition symbol.  These symbols exist to
1027               // support using -u to pull in particular versions.  We
1028               // do not want to record a version for them.
1029               if (st_shndx == elfcpp::SHN_ABS
1030                   && !is_ordinary
1031                   && name_key == version_key)
1032                 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1033                                             false, sym, st_shndx, is_ordinary,
1034                                             st_shndx);
1035               else
1036                 {
1037                   const bool def = (!hidden
1038                                     && st_shndx != elfcpp::SHN_UNDEF);
1039                   res = this->add_from_object(dynobj, name, name_key, version,
1040                                               version_key, def, sym, st_shndx,
1041                                               is_ordinary, st_shndx);
1042                 }
1043             }
1044         }
1045
1046       // Note that it is possible that RES was overridden by an
1047       // earlier object, in which case it can't be aliased here.
1048       if (st_shndx != elfcpp::SHN_UNDEF
1049           && is_ordinary
1050           && sym.get_st_type() == elfcpp::STT_OBJECT
1051           && res->source() == Symbol::FROM_OBJECT
1052           && res->object() == dynobj)
1053         object_symbols.push_back(res);
1054     }
1055
1056   this->record_weak_aliases(&object_symbols);
1057 }
1058
1059 // This is used to sort weak aliases.  We sort them first by section
1060 // index, then by offset, then by weak ahead of strong.
1061
1062 template<int size>
1063 class Weak_alias_sorter
1064 {
1065  public:
1066   bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1067 };
1068
1069 template<int size>
1070 bool
1071 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1072                                     const Sized_symbol<size>* s2) const
1073 {
1074   bool is_ordinary;
1075   unsigned int s1_shndx = s1->shndx(&is_ordinary);
1076   gold_assert(is_ordinary);
1077   unsigned int s2_shndx = s2->shndx(&is_ordinary);
1078   gold_assert(is_ordinary);
1079   if (s1_shndx != s2_shndx)
1080     return s1_shndx < s2_shndx;
1081
1082   if (s1->value() != s2->value())
1083     return s1->value() < s2->value();
1084   if (s1->binding() != s2->binding())
1085     {
1086       if (s1->binding() == elfcpp::STB_WEAK)
1087         return true;
1088       if (s2->binding() == elfcpp::STB_WEAK)
1089         return false;
1090     }
1091   return std::string(s1->name()) < std::string(s2->name());
1092 }
1093
1094 // SYMBOLS is a list of object symbols from a dynamic object.  Look
1095 // for any weak aliases, and record them so that if we add the weak
1096 // alias to the dynamic symbol table, we also add the corresponding
1097 // strong symbol.
1098
1099 template<int size>
1100 void
1101 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1102 {
1103   // Sort the vector by section index, then by offset, then by weak
1104   // ahead of strong.
1105   std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1106
1107   // Walk through the vector.  For each weak definition, record
1108   // aliases.
1109   for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1110          symbols->begin();
1111        p != symbols->end();
1112        ++p)
1113     {
1114       if ((*p)->binding() != elfcpp::STB_WEAK)
1115         continue;
1116
1117       // Build a circular list of weak aliases.  Each symbol points to
1118       // the next one in the circular list.
1119
1120       Sized_symbol<size>* from_sym = *p;
1121       typename std::vector<Sized_symbol<size>*>::const_iterator q;
1122       for (q = p + 1; q != symbols->end(); ++q)
1123         {
1124           bool dummy;
1125           if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1126               || (*q)->value() != from_sym->value())
1127             break;
1128
1129           this->weak_aliases_[from_sym] = *q;
1130           from_sym->set_has_alias();
1131           from_sym = *q;
1132         }
1133
1134       if (from_sym != *p)
1135         {
1136           this->weak_aliases_[from_sym] = *p;
1137           from_sym->set_has_alias();
1138         }
1139
1140       p = q - 1;
1141     }
1142 }
1143
1144 // Create and return a specially defined symbol.  If ONLY_IF_REF is
1145 // true, then only create the symbol if there is a reference to it.
1146 // If this does not return NULL, it sets *POLDSYM to the existing
1147 // symbol if there is one.  This canonicalizes *PNAME and *PVERSION.
1148
1149 template<int size, bool big_endian>
1150 Sized_symbol<size>*
1151 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1152                                     bool only_if_ref,
1153                                     Sized_symbol<size>** poldsym)
1154 {
1155   Symbol* oldsym;
1156   Sized_symbol<size>* sym;
1157   bool add_to_table = false;
1158   typename Symbol_table_type::iterator add_loc = this->table_.end();
1159
1160   // If the caller didn't give us a version, see if we get one from
1161   // the version script.
1162   if (*pversion == NULL)
1163     {
1164       const std::string& v(this->version_script_.get_symbol_version(*pname));
1165       if (!v.empty())
1166         *pversion = v.c_str();
1167     }
1168
1169   if (only_if_ref)
1170     {
1171       oldsym = this->lookup(*pname, *pversion);
1172       if (oldsym == NULL || !oldsym->is_undefined())
1173         return NULL;
1174
1175       *pname = oldsym->name();
1176       *pversion = oldsym->version();
1177     }
1178   else
1179     {
1180       // Canonicalize NAME and VERSION.
1181       Stringpool::Key name_key;
1182       *pname = this->namepool_.add(*pname, true, &name_key);
1183
1184       Stringpool::Key version_key = 0;
1185       if (*pversion != NULL)
1186         *pversion = this->namepool_.add(*pversion, true, &version_key);
1187
1188       Symbol* const snull = NULL;
1189       std::pair<typename Symbol_table_type::iterator, bool> ins =
1190         this->table_.insert(std::make_pair(std::make_pair(name_key,
1191                                                           version_key),
1192                                            snull));
1193
1194       if (!ins.second)
1195         {
1196           // We already have a symbol table entry for NAME/VERSION.
1197           oldsym = ins.first->second;
1198           gold_assert(oldsym != NULL);
1199         }
1200       else
1201         {
1202           // We haven't seen this symbol before.
1203           gold_assert(ins.first->second == NULL);
1204           add_to_table = true;
1205           add_loc = ins.first;
1206           oldsym = NULL;
1207         }
1208     }
1209
1210   const Target& target = parameters->target();
1211   if (!target.has_make_symbol())
1212     sym = new Sized_symbol<size>();
1213   else
1214     {
1215       gold_assert(target.get_size() == size);
1216       gold_assert(target.is_big_endian() ? big_endian : !big_endian);
1217       typedef Sized_target<size, big_endian> My_target;
1218       const My_target* sized_target =
1219           static_cast<const My_target*>(&target);
1220       sym = sized_target->make_symbol();
1221       if (sym == NULL)
1222         return NULL;
1223     }
1224
1225   if (add_to_table)
1226     add_loc->second = sym;
1227   else
1228     gold_assert(oldsym != NULL);
1229
1230   *poldsym = this->get_sized_symbol<size>(oldsym);
1231
1232   return sym;
1233 }
1234
1235 // Define a symbol based on an Output_data.
1236
1237 Symbol*
1238 Symbol_table::define_in_output_data(const char* name,
1239                                     const char* version,
1240                                     Output_data* od,
1241                                     uint64_t value,
1242                                     uint64_t symsize,
1243                                     elfcpp::STT type,
1244                                     elfcpp::STB binding,
1245                                     elfcpp::STV visibility,
1246                                     unsigned char nonvis,
1247                                     bool offset_is_from_end,
1248                                     bool only_if_ref)
1249 {
1250   if (parameters->target().get_size() == 32)
1251     {
1252 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1253       return this->do_define_in_output_data<32>(name, version, od,
1254                                                 value, symsize, type, binding,
1255                                                 visibility, nonvis,
1256                                                 offset_is_from_end,
1257                                                 only_if_ref);
1258 #else
1259       gold_unreachable();
1260 #endif
1261     }
1262   else if (parameters->target().get_size() == 64)
1263     {
1264 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1265       return this->do_define_in_output_data<64>(name, version, od,
1266                                                 value, symsize, type, binding,
1267                                                 visibility, nonvis,
1268                                                 offset_is_from_end,
1269                                                 only_if_ref);
1270 #else
1271       gold_unreachable();
1272 #endif
1273     }
1274   else
1275     gold_unreachable();
1276 }
1277
1278 // Define a symbol in an Output_data, sized version.
1279
1280 template<int size>
1281 Sized_symbol<size>*
1282 Symbol_table::do_define_in_output_data(
1283     const char* name,
1284     const char* version,
1285     Output_data* od,
1286     typename elfcpp::Elf_types<size>::Elf_Addr value,
1287     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1288     elfcpp::STT type,
1289     elfcpp::STB binding,
1290     elfcpp::STV visibility,
1291     unsigned char nonvis,
1292     bool offset_is_from_end,
1293     bool only_if_ref)
1294 {
1295   Sized_symbol<size>* sym;
1296   Sized_symbol<size>* oldsym;
1297
1298   if (parameters->target().is_big_endian())
1299     {
1300 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1301       sym = this->define_special_symbol<size, true>(&name, &version,
1302                                                     only_if_ref, &oldsym);
1303 #else
1304       gold_unreachable();
1305 #endif
1306     }
1307   else
1308     {
1309 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1310       sym = this->define_special_symbol<size, false>(&name, &version,
1311                                                      only_if_ref, &oldsym);
1312 #else
1313       gold_unreachable();
1314 #endif
1315     }
1316
1317   if (sym == NULL)
1318     return NULL;
1319
1320   gold_assert(version == NULL || oldsym != NULL);
1321   sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1322             offset_is_from_end);
1323
1324   if (oldsym == NULL)
1325     {
1326       if (binding == elfcpp::STB_LOCAL
1327           || this->version_script_.symbol_is_local(name))
1328         this->force_local(sym);
1329       return sym;
1330     }
1331
1332   if (Symbol_table::should_override_with_special(oldsym))
1333     this->override_with_special(oldsym, sym);
1334   delete sym;
1335   return oldsym;
1336 }
1337
1338 // Define a symbol based on an Output_segment.
1339
1340 Symbol*
1341 Symbol_table::define_in_output_segment(const char* name,
1342                                        const char* version, Output_segment* os,
1343                                        uint64_t value,
1344                                        uint64_t symsize,
1345                                        elfcpp::STT type,
1346                                        elfcpp::STB binding,
1347                                        elfcpp::STV visibility,
1348                                        unsigned char nonvis,
1349                                        Symbol::Segment_offset_base offset_base,
1350                                        bool only_if_ref)
1351 {
1352   if (parameters->target().get_size() == 32)
1353     {
1354 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1355       return this->do_define_in_output_segment<32>(name, version, os,
1356                                                    value, symsize, type,
1357                                                    binding, visibility, nonvis,
1358                                                    offset_base, only_if_ref);
1359 #else
1360       gold_unreachable();
1361 #endif
1362     }
1363   else if (parameters->target().get_size() == 64)
1364     {
1365 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1366       return this->do_define_in_output_segment<64>(name, version, os,
1367                                                    value, symsize, type,
1368                                                    binding, visibility, nonvis,
1369                                                    offset_base, only_if_ref);
1370 #else
1371       gold_unreachable();
1372 #endif
1373     }
1374   else
1375     gold_unreachable();
1376 }
1377
1378 // Define a symbol in an Output_segment, sized version.
1379
1380 template<int size>
1381 Sized_symbol<size>*
1382 Symbol_table::do_define_in_output_segment(
1383     const char* name,
1384     const char* version,
1385     Output_segment* os,
1386     typename elfcpp::Elf_types<size>::Elf_Addr value,
1387     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1388     elfcpp::STT type,
1389     elfcpp::STB binding,
1390     elfcpp::STV visibility,
1391     unsigned char nonvis,
1392     Symbol::Segment_offset_base offset_base,
1393     bool only_if_ref)
1394 {
1395   Sized_symbol<size>* sym;
1396   Sized_symbol<size>* oldsym;
1397
1398   if (parameters->target().is_big_endian())
1399     {
1400 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1401       sym = this->define_special_symbol<size, true>(&name, &version,
1402                                                     only_if_ref, &oldsym);
1403 #else
1404       gold_unreachable();
1405 #endif
1406     }
1407   else
1408     {
1409 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1410       sym = this->define_special_symbol<size, false>(&name, &version,
1411                                                      only_if_ref, &oldsym);
1412 #else
1413       gold_unreachable();
1414 #endif
1415     }
1416
1417   if (sym == NULL)
1418     return NULL;
1419
1420   gold_assert(version == NULL || oldsym != NULL);
1421   sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1422             offset_base);
1423
1424   if (oldsym == NULL)
1425     {
1426       if (binding == elfcpp::STB_LOCAL
1427           || this->version_script_.symbol_is_local(name))
1428         this->force_local(sym);
1429       return sym;
1430     }
1431
1432   if (Symbol_table::should_override_with_special(oldsym))
1433     this->override_with_special(oldsym, sym);
1434   delete sym;
1435   return oldsym;
1436 }
1437
1438 // Define a special symbol with a constant value.  It is a multiple
1439 // definition error if this symbol is already defined.
1440
1441 Symbol*
1442 Symbol_table::define_as_constant(const char* name,
1443                                  const char* version,
1444                                  uint64_t value,
1445                                  uint64_t symsize,
1446                                  elfcpp::STT type,
1447                                  elfcpp::STB binding,
1448                                  elfcpp::STV visibility,
1449                                  unsigned char nonvis,
1450                                  bool only_if_ref,
1451                                  bool force_override)
1452 {
1453   if (parameters->target().get_size() == 32)
1454     {
1455 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1456       return this->do_define_as_constant<32>(name, version, value,
1457                                              symsize, type, binding,
1458                                              visibility, nonvis, only_if_ref,
1459                                              force_override);
1460 #else
1461       gold_unreachable();
1462 #endif
1463     }
1464   else if (parameters->target().get_size() == 64)
1465     {
1466 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1467       return this->do_define_as_constant<64>(name, version, value,
1468                                              symsize, type, binding,
1469                                              visibility, nonvis, only_if_ref,
1470                                              force_override);
1471 #else
1472       gold_unreachable();
1473 #endif
1474     }
1475   else
1476     gold_unreachable();
1477 }
1478
1479 // Define a symbol as a constant, sized version.
1480
1481 template<int size>
1482 Sized_symbol<size>*
1483 Symbol_table::do_define_as_constant(
1484     const char* name,
1485     const char* version,
1486     typename elfcpp::Elf_types<size>::Elf_Addr value,
1487     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1488     elfcpp::STT type,
1489     elfcpp::STB binding,
1490     elfcpp::STV visibility,
1491     unsigned char nonvis,
1492     bool only_if_ref,
1493     bool force_override)
1494 {
1495   Sized_symbol<size>* sym;
1496   Sized_symbol<size>* oldsym;
1497
1498   if (parameters->target().is_big_endian())
1499     {
1500 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1501       sym = this->define_special_symbol<size, true>(&name, &version,
1502                                                     only_if_ref, &oldsym);
1503 #else
1504       gold_unreachable();
1505 #endif
1506     }
1507   else
1508     {
1509 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1510       sym = this->define_special_symbol<size, false>(&name, &version,
1511                                                      only_if_ref, &oldsym);
1512 #else
1513       gold_unreachable();
1514 #endif
1515     }
1516
1517   if (sym == NULL)
1518     return NULL;
1519
1520   gold_assert(version == NULL || version == name || oldsym != NULL);
1521   sym->init(name, value, symsize, type, binding, visibility, nonvis);
1522
1523   if (oldsym == NULL)
1524     {
1525       // Version symbols are absolute symbols with name == version.
1526       // We don't want to force them to be local.
1527       if ((version == NULL
1528            || name != version
1529            || value != 0)
1530           && (binding == elfcpp::STB_LOCAL
1531               || this->version_script_.symbol_is_local(name)))
1532         this->force_local(sym);
1533       return sym;
1534     }
1535
1536   if (force_override || Symbol_table::should_override_with_special(oldsym))
1537     this->override_with_special(oldsym, sym);
1538   delete sym;
1539   return oldsym;
1540 }
1541
1542 // Define a set of symbols in output sections.
1543
1544 void
1545 Symbol_table::define_symbols(const Layout* layout, int count,
1546                              const Define_symbol_in_section* p,
1547                              bool only_if_ref)
1548 {
1549   for (int i = 0; i < count; ++i, ++p)
1550     {
1551       Output_section* os = layout->find_output_section(p->output_section);
1552       if (os != NULL)
1553         this->define_in_output_data(p->name, NULL, os, p->value,
1554                                     p->size, p->type, p->binding,
1555                                     p->visibility, p->nonvis,
1556                                     p->offset_is_from_end,
1557                                     only_if_ref || p->only_if_ref);
1558       else
1559         this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1560                                  p->binding, p->visibility, p->nonvis,
1561                                  only_if_ref || p->only_if_ref,
1562                                  false);
1563     }
1564 }
1565
1566 // Define a set of symbols in output segments.
1567
1568 void
1569 Symbol_table::define_symbols(const Layout* layout, int count,
1570                              const Define_symbol_in_segment* p,
1571                              bool only_if_ref)
1572 {
1573   for (int i = 0; i < count; ++i, ++p)
1574     {
1575       Output_segment* os = layout->find_output_segment(p->segment_type,
1576                                                        p->segment_flags_set,
1577                                                        p->segment_flags_clear);
1578       if (os != NULL)
1579         this->define_in_output_segment(p->name, NULL, os, p->value,
1580                                        p->size, p->type, p->binding,
1581                                        p->visibility, p->nonvis,
1582                                        p->offset_base,
1583                                        only_if_ref || p->only_if_ref);
1584       else
1585         this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1586                                  p->binding, p->visibility, p->nonvis,
1587                                  only_if_ref || p->only_if_ref,
1588                                  false);
1589     }
1590 }
1591
1592 // Define CSYM using a COPY reloc.  POSD is the Output_data where the
1593 // symbol should be defined--typically a .dyn.bss section.  VALUE is
1594 // the offset within POSD.
1595
1596 template<int size>
1597 void
1598 Symbol_table::define_with_copy_reloc(
1599     Sized_symbol<size>* csym,
1600     Output_data* posd,
1601     typename elfcpp::Elf_types<size>::Elf_Addr value)
1602 {
1603   gold_assert(csym->is_from_dynobj());
1604   gold_assert(!csym->is_copied_from_dynobj());
1605   Object* object = csym->object();
1606   gold_assert(object->is_dynamic());
1607   Dynobj* dynobj = static_cast<Dynobj*>(object);
1608
1609   // Our copied variable has to override any variable in a shared
1610   // library.
1611   elfcpp::STB binding = csym->binding();
1612   if (binding == elfcpp::STB_WEAK)
1613     binding = elfcpp::STB_GLOBAL;
1614
1615   this->define_in_output_data(csym->name(), csym->version(),
1616                               posd, value, csym->symsize(),
1617                               csym->type(), binding,
1618                               csym->visibility(), csym->nonvis(),
1619                               false, false);
1620
1621   csym->set_is_copied_from_dynobj();
1622   csym->set_needs_dynsym_entry();
1623
1624   this->copied_symbol_dynobjs_[csym] = dynobj;
1625
1626   // We have now defined all aliases, but we have not entered them all
1627   // in the copied_symbol_dynobjs_ map.
1628   if (csym->has_alias())
1629     {
1630       Symbol* sym = csym;
1631       while (true)
1632         {
1633           sym = this->weak_aliases_[sym];
1634           if (sym == csym)
1635             break;
1636           gold_assert(sym->output_data() == posd);
1637
1638           sym->set_is_copied_from_dynobj();
1639           this->copied_symbol_dynobjs_[sym] = dynobj;
1640         }
1641     }
1642 }
1643
1644 // SYM is defined using a COPY reloc.  Return the dynamic object where
1645 // the original definition was found.
1646
1647 Dynobj*
1648 Symbol_table::get_copy_source(const Symbol* sym) const
1649 {
1650   gold_assert(sym->is_copied_from_dynobj());
1651   Copied_symbol_dynobjs::const_iterator p =
1652     this->copied_symbol_dynobjs_.find(sym);
1653   gold_assert(p != this->copied_symbol_dynobjs_.end());
1654   return p->second;
1655 }
1656
1657 // Set the dynamic symbol indexes.  INDEX is the index of the first
1658 // global dynamic symbol.  Pointers to the symbols are stored into the
1659 // vector SYMS.  The names are added to DYNPOOL.  This returns an
1660 // updated dynamic symbol index.
1661
1662 unsigned int
1663 Symbol_table::set_dynsym_indexes(unsigned int index,
1664                                  std::vector<Symbol*>* syms,
1665                                  Stringpool* dynpool,
1666                                  Versions* versions)
1667 {
1668   for (Symbol_table_type::iterator p = this->table_.begin();
1669        p != this->table_.end();
1670        ++p)
1671     {
1672       Symbol* sym = p->second;
1673
1674       // Note that SYM may already have a dynamic symbol index, since
1675       // some symbols appear more than once in the symbol table, with
1676       // and without a version.
1677
1678       if (!sym->should_add_dynsym_entry())
1679         sym->set_dynsym_index(-1U);
1680       else if (!sym->has_dynsym_index())
1681         {
1682           sym->set_dynsym_index(index);
1683           ++index;
1684           syms->push_back(sym);
1685           dynpool->add(sym->name(), false, NULL);
1686
1687           // Record any version information.
1688           if (sym->version() != NULL)
1689             versions->record_version(this, dynpool, sym);
1690         }
1691     }
1692
1693   // Finish up the versions.  In some cases this may add new dynamic
1694   // symbols.
1695   index = versions->finalize(this, index, syms);
1696
1697   return index;
1698 }
1699
1700 // Set the final values for all the symbols.  The index of the first
1701 // global symbol in the output file is *PLOCAL_SYMCOUNT.  Record the
1702 // file offset OFF.  Add their names to POOL.  Return the new file
1703 // offset.  Update *PLOCAL_SYMCOUNT if necessary.
1704
1705 off_t
1706 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
1707                        size_t dyncount, Stringpool* pool,
1708                        unsigned int *plocal_symcount)
1709 {
1710   off_t ret;
1711
1712   gold_assert(*plocal_symcount != 0);
1713   this->first_global_index_ = *plocal_symcount;
1714
1715   this->dynamic_offset_ = dynoff;
1716   this->first_dynamic_global_index_ = dyn_global_index;
1717   this->dynamic_count_ = dyncount;
1718
1719   if (parameters->target().get_size() == 32)
1720     {
1721 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1722       ret = this->sized_finalize<32>(off, pool, plocal_symcount);
1723 #else
1724       gold_unreachable();
1725 #endif
1726     }
1727   else if (parameters->target().get_size() == 64)
1728     {
1729 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1730       ret = this->sized_finalize<64>(off, pool, plocal_symcount);
1731 #else
1732       gold_unreachable();
1733 #endif
1734     }
1735   else
1736     gold_unreachable();
1737
1738   // Now that we have the final symbol table, we can reliably note
1739   // which symbols should get warnings.
1740   this->warnings_.note_warnings(this);
1741
1742   return ret;
1743 }
1744
1745 // SYM is going into the symbol table at *PINDEX.  Add the name to
1746 // POOL, update *PINDEX and *POFF.
1747
1748 template<int size>
1749 void
1750 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
1751                                   unsigned int* pindex, off_t* poff)
1752 {
1753   sym->set_symtab_index(*pindex);
1754   pool->add(sym->name(), false, NULL);
1755   ++*pindex;
1756   *poff += elfcpp::Elf_sizes<size>::sym_size;
1757 }
1758
1759 // Set the final value for all the symbols.  This is called after
1760 // Layout::finalize, so all the output sections have their final
1761 // address.
1762
1763 template<int size>
1764 off_t
1765 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
1766                              unsigned int* plocal_symcount)
1767 {
1768   off = align_address(off, size >> 3);
1769   this->offset_ = off;
1770
1771   unsigned int index = *plocal_symcount;
1772   const unsigned int orig_index = index;
1773
1774   // First do all the symbols which have been forced to be local, as
1775   // they must appear before all global symbols.
1776   for (Forced_locals::iterator p = this->forced_locals_.begin();
1777        p != this->forced_locals_.end();
1778        ++p)
1779     {
1780       Symbol* sym = *p;
1781       gold_assert(sym->is_forced_local());
1782       if (this->sized_finalize_symbol<size>(sym))
1783         {
1784           this->add_to_final_symtab<size>(sym, pool, &index, &off);
1785           ++*plocal_symcount;
1786         }
1787     }
1788
1789   // Now do all the remaining symbols.
1790   for (Symbol_table_type::iterator p = this->table_.begin();
1791        p != this->table_.end();
1792        ++p)
1793     {
1794       Symbol* sym = p->second;
1795       if (this->sized_finalize_symbol<size>(sym))
1796         this->add_to_final_symtab<size>(sym, pool, &index, &off);
1797     }
1798
1799   this->output_count_ = index - orig_index;
1800
1801   return off;
1802 }
1803
1804 // Finalize the symbol SYM.  This returns true if the symbol should be
1805 // added to the symbol table, false otherwise.
1806
1807 template<int size>
1808 bool
1809 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
1810 {
1811   Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
1812
1813   // The default version of a symbol may appear twice in the symbol
1814   // table.  We only need to finalize it once.
1815   if (sym->has_symtab_index())
1816     return false;
1817
1818   if (!sym->in_reg())
1819     {
1820       gold_assert(!sym->has_symtab_index());
1821       sym->set_symtab_index(-1U);
1822       gold_assert(sym->dynsym_index() == -1U);
1823       return false;
1824     }
1825
1826   typename Sized_symbol<size>::Value_type value;
1827
1828   switch (sym->source())
1829     {
1830     case Symbol::FROM_OBJECT:
1831       {
1832         bool is_ordinary;
1833         unsigned int shndx = sym->shndx(&is_ordinary);
1834
1835         // FIXME: We need some target specific support here.
1836         if (!is_ordinary
1837             && shndx != elfcpp::SHN_ABS
1838             && shndx != elfcpp::SHN_COMMON)
1839           {
1840             gold_error(_("%s: unsupported symbol section 0x%x"),
1841                        sym->demangled_name().c_str(), shndx);
1842             shndx = elfcpp::SHN_UNDEF;
1843           }
1844
1845         Object* symobj = sym->object();
1846         if (symobj->is_dynamic())
1847           {
1848             value = 0;
1849             shndx = elfcpp::SHN_UNDEF;
1850           }
1851         else if (shndx == elfcpp::SHN_UNDEF)
1852           value = 0;
1853         else if (!is_ordinary
1854                  && (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON))
1855           value = sym->value();
1856         else
1857           {
1858             Relobj* relobj = static_cast<Relobj*>(symobj);
1859             section_offset_type secoff;
1860             Output_section* os = relobj->output_section(shndx, &secoff);
1861
1862             if (os == NULL)
1863               {
1864                 sym->set_symtab_index(-1U);
1865                 gold_assert(sym->dynsym_index() == -1U);
1866                 return false;
1867               }
1868
1869             if (sym->type() == elfcpp::STT_TLS)
1870               value = sym->value() + os->tls_offset() + secoff;
1871             else
1872               value = sym->value() + os->address() + secoff;
1873           }
1874       }
1875       break;
1876
1877     case Symbol::IN_OUTPUT_DATA:
1878       {
1879         Output_data* od = sym->output_data();
1880         value = sym->value();
1881         if (sym->type() != elfcpp::STT_TLS)
1882           value += od->address();
1883         else
1884           {
1885             Output_section* os = od->output_section();
1886             gold_assert(os != NULL);
1887             value += os->tls_offset() + (od->address() - os->address());
1888           }
1889         if (sym->offset_is_from_end())
1890           value += od->data_size();
1891       }
1892       break;
1893
1894     case Symbol::IN_OUTPUT_SEGMENT:
1895       {
1896         Output_segment* os = sym->output_segment();
1897         value = sym->value();
1898         if (sym->type() != elfcpp::STT_TLS)
1899           value += os->vaddr();
1900         switch (sym->offset_base())
1901           {
1902           case Symbol::SEGMENT_START:
1903             break;
1904           case Symbol::SEGMENT_END:
1905             value += os->memsz();
1906             break;
1907           case Symbol::SEGMENT_BSS:
1908             value += os->filesz();
1909             break;
1910           default:
1911             gold_unreachable();
1912           }
1913       }
1914       break;
1915
1916     case Symbol::CONSTANT:
1917       value = sym->value();
1918       break;
1919
1920     default:
1921       gold_unreachable();
1922     }
1923
1924   sym->set_value(value);
1925
1926   if (parameters->options().strip_all())
1927     {
1928       sym->set_symtab_index(-1U);
1929       return false;
1930     }
1931
1932   return true;
1933 }
1934
1935 // Write out the global symbols.
1936
1937 void
1938 Symbol_table::write_globals(const Input_objects* input_objects,
1939                             const Stringpool* sympool,
1940                             const Stringpool* dynpool,
1941                             Output_symtab_xindex* symtab_xindex,
1942                             Output_symtab_xindex* dynsym_xindex,
1943                             Output_file* of) const
1944 {
1945   switch (parameters->size_and_endianness())
1946     {
1947 #ifdef HAVE_TARGET_32_LITTLE
1948     case Parameters::TARGET_32_LITTLE:
1949       this->sized_write_globals<32, false>(input_objects, sympool,
1950                                            dynpool, symtab_xindex,
1951                                            dynsym_xindex, of);
1952       break;
1953 #endif
1954 #ifdef HAVE_TARGET_32_BIG
1955     case Parameters::TARGET_32_BIG:
1956       this->sized_write_globals<32, true>(input_objects, sympool,
1957                                           dynpool, symtab_xindex,
1958                                           dynsym_xindex, of);
1959       break;
1960 #endif
1961 #ifdef HAVE_TARGET_64_LITTLE
1962     case Parameters::TARGET_64_LITTLE:
1963       this->sized_write_globals<64, false>(input_objects, sympool,
1964                                            dynpool, symtab_xindex,
1965                                            dynsym_xindex, of);
1966       break;
1967 #endif
1968 #ifdef HAVE_TARGET_64_BIG
1969     case Parameters::TARGET_64_BIG:
1970       this->sized_write_globals<64, true>(input_objects, sympool,
1971                                           dynpool, symtab_xindex,
1972                                           dynsym_xindex, of);
1973       break;
1974 #endif
1975     default:
1976       gold_unreachable();
1977     }
1978 }
1979
1980 // Write out the global symbols.
1981
1982 template<int size, bool big_endian>
1983 void
1984 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1985                                   const Stringpool* sympool,
1986                                   const Stringpool* dynpool,
1987                                   Output_symtab_xindex* symtab_xindex,
1988                                   Output_symtab_xindex* dynsym_xindex,
1989                                   Output_file* of) const
1990 {
1991   const Target& target = parameters->target();
1992
1993   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
1994
1995   const unsigned int output_count = this->output_count_;
1996   const section_size_type oview_size = output_count * sym_size;
1997   const unsigned int first_global_index = this->first_global_index_;
1998   unsigned char* psyms;
1999   if (this->offset_ == 0 || output_count == 0)
2000     psyms = NULL;
2001   else
2002     psyms = of->get_output_view(this->offset_, oview_size);
2003
2004   const unsigned int dynamic_count = this->dynamic_count_;
2005   const section_size_type dynamic_size = dynamic_count * sym_size;
2006   const unsigned int first_dynamic_global_index =
2007     this->first_dynamic_global_index_;
2008   unsigned char* dynamic_view;
2009   if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2010     dynamic_view = NULL;
2011   else
2012     dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2013
2014   for (Symbol_table_type::const_iterator p = this->table_.begin();
2015        p != this->table_.end();
2016        ++p)
2017     {
2018       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2019
2020       // Possibly warn about unresolved symbols in shared libraries.
2021       this->warn_about_undefined_dynobj_symbol(input_objects, sym);
2022
2023       unsigned int sym_index = sym->symtab_index();
2024       unsigned int dynsym_index;
2025       if (dynamic_view == NULL)
2026         dynsym_index = -1U;
2027       else
2028         dynsym_index = sym->dynsym_index();
2029
2030       if (sym_index == -1U && dynsym_index == -1U)
2031         {
2032           // This symbol is not included in the output file.
2033           continue;
2034         }
2035
2036       unsigned int shndx;
2037       typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2038       typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2039       switch (sym->source())
2040         {
2041         case Symbol::FROM_OBJECT:
2042           {
2043             bool is_ordinary;
2044             unsigned int in_shndx = sym->shndx(&is_ordinary);
2045
2046             // FIXME: We need some target specific support here.
2047             if (!is_ordinary
2048                 && in_shndx != elfcpp::SHN_ABS
2049                 && in_shndx != elfcpp::SHN_COMMON)
2050               {
2051                 gold_error(_("%s: unsupported symbol section 0x%x"),
2052                            sym->demangled_name().c_str(), in_shndx);
2053                 shndx = in_shndx;
2054               }
2055             else
2056               {
2057                 Object* symobj = sym->object();
2058                 if (symobj->is_dynamic())
2059                   {
2060                     if (sym->needs_dynsym_value())
2061                       dynsym_value = target.dynsym_value(sym);
2062                     shndx = elfcpp::SHN_UNDEF;
2063                   }
2064                 else if (in_shndx == elfcpp::SHN_UNDEF
2065                          || (!is_ordinary
2066                              && (in_shndx == elfcpp::SHN_ABS
2067                                  || in_shndx == elfcpp::SHN_COMMON)))
2068                   shndx = in_shndx;
2069                 else
2070                   {
2071                     Relobj* relobj = static_cast<Relobj*>(symobj);
2072                     section_offset_type secoff;
2073                     Output_section* os = relobj->output_section(in_shndx,
2074                                                                 &secoff);
2075                     gold_assert(os != NULL);
2076                     shndx = os->out_shndx();
2077
2078                     if (shndx >= elfcpp::SHN_LORESERVE)
2079                       {
2080                         if (sym_index != -1U)
2081                           symtab_xindex->add(sym_index, shndx);
2082                         if (dynsym_index != -1U)
2083                           dynsym_xindex->add(dynsym_index, shndx);
2084                         shndx = elfcpp::SHN_XINDEX;
2085                       }
2086
2087                     // In object files symbol values are section
2088                     // relative.
2089                     if (parameters->options().relocatable())
2090                       sym_value -= os->address();
2091                   }
2092               }
2093           }
2094           break;
2095
2096         case Symbol::IN_OUTPUT_DATA:
2097           shndx = sym->output_data()->out_shndx();
2098           if (shndx >= elfcpp::SHN_LORESERVE)
2099             {
2100               if (sym_index != -1U)
2101                 symtab_xindex->add(sym_index, shndx);
2102               if (dynsym_index != -1U)
2103                 dynsym_xindex->add(dynsym_index, shndx);
2104               shndx = elfcpp::SHN_XINDEX;
2105             }
2106           break;
2107
2108         case Symbol::IN_OUTPUT_SEGMENT:
2109           shndx = elfcpp::SHN_ABS;
2110           break;
2111
2112         case Symbol::CONSTANT:
2113           shndx = elfcpp::SHN_ABS;
2114           break;
2115
2116         default:
2117           gold_unreachable();
2118         }
2119
2120       if (sym_index != -1U)
2121         {
2122           sym_index -= first_global_index;
2123           gold_assert(sym_index < output_count);
2124           unsigned char* ps = psyms + (sym_index * sym_size);
2125           this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2126                                                      sympool, ps);
2127         }
2128
2129       if (dynsym_index != -1U)
2130         {
2131           dynsym_index -= first_dynamic_global_index;
2132           gold_assert(dynsym_index < dynamic_count);
2133           unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2134           this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2135                                                      dynpool, pd);
2136         }
2137     }
2138
2139   of->write_output_view(this->offset_, oview_size, psyms);
2140   if (dynamic_view != NULL)
2141     of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2142 }
2143
2144 // Write out the symbol SYM, in section SHNDX, to P.  POOL is the
2145 // strtab holding the name.
2146
2147 template<int size, bool big_endian>
2148 void
2149 Symbol_table::sized_write_symbol(
2150     Sized_symbol<size>* sym,
2151     typename elfcpp::Elf_types<size>::Elf_Addr value,
2152     unsigned int shndx,
2153     const Stringpool* pool,
2154     unsigned char* p) const
2155 {
2156   elfcpp::Sym_write<size, big_endian> osym(p);
2157   osym.put_st_name(pool->get_offset(sym->name()));
2158   osym.put_st_value(value);
2159   osym.put_st_size(sym->symsize());
2160   // A version script may have overridden the default binding.
2161   if (sym->is_forced_local())
2162     osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2163   else
2164     osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2165   osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2166   osym.put_st_shndx(shndx);
2167 }
2168
2169 // Check for unresolved symbols in shared libraries.  This is
2170 // controlled by the --allow-shlib-undefined option.
2171
2172 // We only warn about libraries for which we have seen all the
2173 // DT_NEEDED entries.  We don't try to track down DT_NEEDED entries
2174 // which were not seen in this link.  If we didn't see a DT_NEEDED
2175 // entry, we aren't going to be able to reliably report whether the
2176 // symbol is undefined.
2177
2178 // We also don't warn about libraries found in the system library
2179 // directory (the directory were we find libc.so); we assume that
2180 // those libraries are OK.  This heuristic avoids problems in
2181 // GNU/Linux, in which -ldl can have undefined references satisfied by
2182 // ld-linux.so.
2183
2184 inline void
2185 Symbol_table::warn_about_undefined_dynobj_symbol(
2186     const Input_objects* input_objects,
2187     Symbol* sym) const
2188 {
2189   bool dummy;
2190   if (sym->source() == Symbol::FROM_OBJECT
2191       && sym->object()->is_dynamic()
2192       && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2193       && sym->binding() != elfcpp::STB_WEAK
2194       && !parameters->options().allow_shlib_undefined()
2195       && !parameters->target().is_defined_by_abi(sym)
2196       && !input_objects->found_in_system_library_directory(sym->object()))
2197     {
2198       // A very ugly cast.
2199       Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2200       if (!dynobj->has_unknown_needed_entries())
2201         gold_error(_("%s: undefined reference to '%s'"),
2202                    sym->object()->name().c_str(),
2203                    sym->demangled_name().c_str());
2204     }
2205 }
2206
2207 // Write out a section symbol.  Return the update offset.
2208
2209 void
2210 Symbol_table::write_section_symbol(const Output_section *os,
2211                                    Output_symtab_xindex* symtab_xindex,
2212                                    Output_file* of,
2213                                    off_t offset) const
2214 {
2215   switch (parameters->size_and_endianness())
2216     {
2217 #ifdef HAVE_TARGET_32_LITTLE
2218     case Parameters::TARGET_32_LITTLE:
2219       this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2220                                                   offset);
2221       break;
2222 #endif
2223 #ifdef HAVE_TARGET_32_BIG
2224     case Parameters::TARGET_32_BIG:
2225       this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2226                                                  offset);
2227       break;
2228 #endif
2229 #ifdef HAVE_TARGET_64_LITTLE
2230     case Parameters::TARGET_64_LITTLE:
2231       this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2232                                                   offset);
2233       break;
2234 #endif
2235 #ifdef HAVE_TARGET_64_BIG
2236     case Parameters::TARGET_64_BIG:
2237       this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2238                                                  offset);
2239       break;
2240 #endif
2241     default:
2242       gold_unreachable();
2243     }
2244 }
2245
2246 // Write out a section symbol, specialized for size and endianness.
2247
2248 template<int size, bool big_endian>
2249 void
2250 Symbol_table::sized_write_section_symbol(const Output_section* os,
2251                                          Output_symtab_xindex* symtab_xindex,
2252                                          Output_file* of,
2253                                          off_t offset) const
2254 {
2255   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2256
2257   unsigned char* pov = of->get_output_view(offset, sym_size);
2258
2259   elfcpp::Sym_write<size, big_endian> osym(pov);
2260   osym.put_st_name(0);
2261   osym.put_st_value(os->address());
2262   osym.put_st_size(0);
2263   osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2264                                        elfcpp::STT_SECTION));
2265   osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2266
2267   unsigned int shndx = os->out_shndx();
2268   if (shndx >= elfcpp::SHN_LORESERVE)
2269     {
2270       symtab_xindex->add(os->symtab_index(), shndx);
2271       shndx = elfcpp::SHN_XINDEX;
2272     }
2273   osym.put_st_shndx(shndx);
2274
2275   of->write_output_view(offset, sym_size, pov);
2276 }
2277
2278 // Print statistical information to stderr.  This is used for --stats.
2279
2280 void
2281 Symbol_table::print_stats() const
2282 {
2283 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2284   fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2285           program_name, this->table_.size(), this->table_.bucket_count());
2286 #else
2287   fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2288           program_name, this->table_.size());
2289 #endif
2290   this->namepool_.print_stats("symbol table stringpool");
2291 }
2292
2293 // We check for ODR violations by looking for symbols with the same
2294 // name for which the debugging information reports that they were
2295 // defined in different source locations.  When comparing the source
2296 // location, we consider instances with the same base filename and
2297 // line number to be the same.  This is because different object
2298 // files/shared libraries can include the same header file using
2299 // different paths, and we don't want to report an ODR violation in
2300 // that case.
2301
2302 // This struct is used to compare line information, as returned by
2303 // Dwarf_line_info::one_addr2line.  It implements a < comparison
2304 // operator used with std::set.
2305
2306 struct Odr_violation_compare
2307 {
2308   bool
2309   operator()(const std::string& s1, const std::string& s2) const
2310   {
2311     std::string::size_type pos1 = s1.rfind('/');
2312     std::string::size_type pos2 = s2.rfind('/');
2313     if (pos1 == std::string::npos
2314         || pos2 == std::string::npos)
2315       return s1 < s2;
2316     return s1.compare(pos1, std::string::npos,
2317                       s2, pos2, std::string::npos) < 0;
2318   }
2319 };
2320
2321 // Check candidate_odr_violations_ to find symbols with the same name
2322 // but apparently different definitions (different source-file/line-no).
2323
2324 void
2325 Symbol_table::detect_odr_violations(const Task* task,
2326                                     const char* output_file_name) const
2327 {
2328   for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2329        it != candidate_odr_violations_.end();
2330        ++it)
2331     {
2332       const char* symbol_name = it->first;
2333       // We use a sorted set so the output is deterministic.
2334       std::set<std::string, Odr_violation_compare> line_nums;
2335
2336       for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2337                locs = it->second.begin();
2338            locs != it->second.end();
2339            ++locs)
2340         {
2341           // We need to lock the object in order to read it.  This
2342           // means that we have to run in a singleton Task.  If we
2343           // want to run this in a general Task for better
2344           // performance, we will need one Task for object, plus
2345           // appropriate locking to ensure that we don't conflict with
2346           // other uses of the object.
2347           Task_lock_obj<Object> tl(task, locs->object);
2348           std::string lineno = Dwarf_line_info::one_addr2line(
2349               locs->object, locs->shndx, locs->offset);
2350           if (!lineno.empty())
2351             line_nums.insert(lineno);
2352         }
2353
2354       if (line_nums.size() > 1)
2355         {
2356           gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2357                          "places (possible ODR violation):"),
2358                        output_file_name, demangle(symbol_name).c_str());
2359           for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2360                it2 != line_nums.end();
2361                ++it2)
2362             fprintf(stderr, "  %s\n", it2->c_str());
2363         }
2364     }
2365 }
2366
2367 // Warnings functions.
2368
2369 // Add a new warning.
2370
2371 void
2372 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2373                       const std::string& warning)
2374 {
2375   name = symtab->canonicalize_name(name);
2376   this->warnings_[name].set(obj, warning);
2377 }
2378
2379 // Look through the warnings and mark the symbols for which we should
2380 // warn.  This is called during Layout::finalize when we know the
2381 // sources for all the symbols.
2382
2383 void
2384 Warnings::note_warnings(Symbol_table* symtab)
2385 {
2386   for (Warning_table::iterator p = this->warnings_.begin();
2387        p != this->warnings_.end();
2388        ++p)
2389     {
2390       Symbol* sym = symtab->lookup(p->first, NULL);
2391       if (sym != NULL
2392           && sym->source() == Symbol::FROM_OBJECT
2393           && sym->object() == p->second.object)
2394         sym->set_has_warning();
2395     }
2396 }
2397
2398 // Issue a warning.  This is called when we see a relocation against a
2399 // symbol for which has a warning.
2400
2401 template<int size, bool big_endian>
2402 void
2403 Warnings::issue_warning(const Symbol* sym,
2404                         const Relocate_info<size, big_endian>* relinfo,
2405                         size_t relnum, off_t reloffset) const
2406 {
2407   gold_assert(sym->has_warning());
2408   Warning_table::const_iterator p = this->warnings_.find(sym->name());
2409   gold_assert(p != this->warnings_.end());
2410   gold_warning_at_location(relinfo, relnum, reloffset,
2411                            "%s", p->second.text.c_str());
2412 }
2413
2414 // Instantiate the templates we need.  We could use the configure
2415 // script to restrict this to only the ones needed for implemented
2416 // targets.
2417
2418 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2419 template
2420 void
2421 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2422 #endif
2423
2424 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2425 template
2426 void
2427 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2428 #endif
2429
2430 #ifdef HAVE_TARGET_32_LITTLE
2431 template
2432 void
2433 Symbol_table::add_from_relobj<32, false>(
2434     Sized_relobj<32, false>* relobj,
2435     const unsigned char* syms,
2436     size_t count,
2437     size_t symndx_offset,
2438     const char* sym_names,
2439     size_t sym_name_size,
2440     Sized_relobj<32, true>::Symbols* sympointers);
2441 #endif
2442
2443 #ifdef HAVE_TARGET_32_BIG
2444 template
2445 void
2446 Symbol_table::add_from_relobj<32, true>(
2447     Sized_relobj<32, true>* relobj,
2448     const unsigned char* syms,
2449     size_t count,
2450     size_t symndx_offset,
2451     const char* sym_names,
2452     size_t sym_name_size,
2453     Sized_relobj<32, false>::Symbols* sympointers);
2454 #endif
2455
2456 #ifdef HAVE_TARGET_64_LITTLE
2457 template
2458 void
2459 Symbol_table::add_from_relobj<64, false>(
2460     Sized_relobj<64, false>* relobj,
2461     const unsigned char* syms,
2462     size_t count,
2463     size_t symndx_offset,
2464     const char* sym_names,
2465     size_t sym_name_size,
2466     Sized_relobj<64, true>::Symbols* sympointers);
2467 #endif
2468
2469 #ifdef HAVE_TARGET_64_BIG
2470 template
2471 void
2472 Symbol_table::add_from_relobj<64, true>(
2473     Sized_relobj<64, true>* relobj,
2474     const unsigned char* syms,
2475     size_t count,
2476     size_t symndx_offset,
2477     const char* sym_names,
2478     size_t sym_name_size,
2479     Sized_relobj<64, false>::Symbols* sympointers);
2480 #endif
2481
2482 #ifdef HAVE_TARGET_32_LITTLE
2483 template
2484 void
2485 Symbol_table::add_from_dynobj<32, false>(
2486     Sized_dynobj<32, false>* dynobj,
2487     const unsigned char* syms,
2488     size_t count,
2489     const char* sym_names,
2490     size_t sym_name_size,
2491     const unsigned char* versym,
2492     size_t versym_size,
2493     const std::vector<const char*>* version_map);
2494 #endif
2495
2496 #ifdef HAVE_TARGET_32_BIG
2497 template
2498 void
2499 Symbol_table::add_from_dynobj<32, true>(
2500     Sized_dynobj<32, true>* dynobj,
2501     const unsigned char* syms,
2502     size_t count,
2503     const char* sym_names,
2504     size_t sym_name_size,
2505     const unsigned char* versym,
2506     size_t versym_size,
2507     const std::vector<const char*>* version_map);
2508 #endif
2509
2510 #ifdef HAVE_TARGET_64_LITTLE
2511 template
2512 void
2513 Symbol_table::add_from_dynobj<64, false>(
2514     Sized_dynobj<64, false>* dynobj,
2515     const unsigned char* syms,
2516     size_t count,
2517     const char* sym_names,
2518     size_t sym_name_size,
2519     const unsigned char* versym,
2520     size_t versym_size,
2521     const std::vector<const char*>* version_map);
2522 #endif
2523
2524 #ifdef HAVE_TARGET_64_BIG
2525 template
2526 void
2527 Symbol_table::add_from_dynobj<64, true>(
2528     Sized_dynobj<64, true>* dynobj,
2529     const unsigned char* syms,
2530     size_t count,
2531     const char* sym_names,
2532     size_t sym_name_size,
2533     const unsigned char* versym,
2534     size_t versym_size,
2535     const std::vector<const char*>* version_map);
2536 #endif
2537
2538 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2539 template
2540 void
2541 Symbol_table::define_with_copy_reloc<32>(
2542     Sized_symbol<32>* sym,
2543     Output_data* posd,
2544     elfcpp::Elf_types<32>::Elf_Addr value);
2545 #endif
2546
2547 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2548 template
2549 void
2550 Symbol_table::define_with_copy_reloc<64>(
2551     Sized_symbol<64>* sym,
2552     Output_data* posd,
2553     elfcpp::Elf_types<64>::Elf_Addr value);
2554 #endif
2555
2556 #ifdef HAVE_TARGET_32_LITTLE
2557 template
2558 void
2559 Warnings::issue_warning<32, false>(const Symbol* sym,
2560                                    const Relocate_info<32, false>* relinfo,
2561                                    size_t relnum, off_t reloffset) const;
2562 #endif
2563
2564 #ifdef HAVE_TARGET_32_BIG
2565 template
2566 void
2567 Warnings::issue_warning<32, true>(const Symbol* sym,
2568                                   const Relocate_info<32, true>* relinfo,
2569                                   size_t relnum, off_t reloffset) const;
2570 #endif
2571
2572 #ifdef HAVE_TARGET_64_LITTLE
2573 template
2574 void
2575 Warnings::issue_warning<64, false>(const Symbol* sym,
2576                                    const Relocate_info<64, false>* relinfo,
2577                                    size_t relnum, off_t reloffset) const;
2578 #endif
2579
2580 #ifdef HAVE_TARGET_64_BIG
2581 template
2582 void
2583 Warnings::issue_warning<64, true>(const Symbol* sym,
2584                                   const Relocate_info<64, true>* relinfo,
2585                                   size_t relnum, off_t reloffset) const;
2586 #endif
2587
2588 } // End namespace gold.