* symtab.cc (Symbol_table::add_from_dynobj): If we see a protected
[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       // A protected symbol in a shared library must be treated as a
946       // normal symbol when viewed from outside the shared library.
947       // Implement this by overriding the visibility here.
948       elfcpp::Sym<size, big_endian>* psym = &sym;
949       unsigned char symbuf[sym_size];
950       elfcpp::Sym<size, big_endian> sym2(symbuf);
951       if (sym.get_st_visibility() == elfcpp::STV_PROTECTED)
952         {
953           memcpy(symbuf, p, sym_size);
954           elfcpp::Sym_write<size, big_endian> sw(symbuf);
955           sw.put_st_other(elfcpp::STV_DEFAULT, sym.get_st_nonvis());
956           psym = &sym2;
957         }
958
959       unsigned int st_name = psym->get_st_name();
960       if (st_name >= sym_name_size)
961         {
962           dynobj->error(_("bad symbol name offset %u at %zu"),
963                         st_name, i);
964           continue;
965         }
966
967       const char* name = sym_names + st_name;
968
969       bool is_ordinary;
970       unsigned int st_shndx = dynobj->adjust_sym_shndx(i, psym->get_st_shndx(),
971                                                        &is_ordinary);
972
973       Sized_symbol<size>* res;
974
975       if (versym == NULL)
976         {
977           Stringpool::Key name_key;
978           name = this->namepool_.add(name, true, &name_key);
979           res = this->add_from_object(dynobj, name, name_key, NULL, 0,
980                                       false, *psym, st_shndx, is_ordinary,
981                                       st_shndx);
982         }
983       else
984         {
985           // Read the version information.
986
987           unsigned int v = elfcpp::Swap<16, big_endian>::readval(vs);
988
989           bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
990           v &= elfcpp::VERSYM_VERSION;
991
992           // The Sun documentation says that V can be VER_NDX_LOCAL,
993           // or VER_NDX_GLOBAL, or a version index.  The meaning of
994           // VER_NDX_LOCAL is defined as "Symbol has local scope."
995           // The old GNU linker will happily generate VER_NDX_LOCAL
996           // for an undefined symbol.  I don't know what the Sun
997           // linker will generate.
998
999           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1000               && st_shndx != elfcpp::SHN_UNDEF)
1001             {
1002               // This symbol should not be visible outside the object.
1003               continue;
1004             }
1005
1006           // At this point we are definitely going to add this symbol.
1007           Stringpool::Key name_key;
1008           name = this->namepool_.add(name, true, &name_key);
1009
1010           if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
1011               || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
1012             {
1013               // This symbol does not have a version.
1014               res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1015                                           false, *psym, st_shndx, is_ordinary,
1016                                           st_shndx);
1017             }
1018           else
1019             {
1020               if (v >= version_map->size())
1021                 {
1022                   dynobj->error(_("versym for symbol %zu out of range: %u"),
1023                                 i, v);
1024                   continue;
1025                 }
1026
1027               const char* version = (*version_map)[v];
1028               if (version == NULL)
1029                 {
1030                   dynobj->error(_("versym for symbol %zu has no name: %u"),
1031                                 i, v);
1032                   continue;
1033                 }
1034
1035               Stringpool::Key version_key;
1036               version = this->namepool_.add(version, true, &version_key);
1037
1038               // If this is an absolute symbol, and the version name
1039               // and symbol name are the same, then this is the
1040               // version definition symbol.  These symbols exist to
1041               // support using -u to pull in particular versions.  We
1042               // do not want to record a version for them.
1043               if (st_shndx == elfcpp::SHN_ABS
1044                   && !is_ordinary
1045                   && name_key == version_key)
1046                 res = this->add_from_object(dynobj, name, name_key, NULL, 0,
1047                                             false, *psym, st_shndx, is_ordinary,
1048                                             st_shndx);
1049               else
1050                 {
1051                   const bool def = (!hidden
1052                                     && st_shndx != elfcpp::SHN_UNDEF);
1053                   res = this->add_from_object(dynobj, name, name_key, version,
1054                                               version_key, def, *psym, st_shndx,
1055                                               is_ordinary, st_shndx);
1056                 }
1057             }
1058         }
1059
1060       // Note that it is possible that RES was overridden by an
1061       // earlier object, in which case it can't be aliased here.
1062       if (st_shndx != elfcpp::SHN_UNDEF
1063           && is_ordinary
1064           && psym->get_st_type() == elfcpp::STT_OBJECT
1065           && res->source() == Symbol::FROM_OBJECT
1066           && res->object() == dynobj)
1067         object_symbols.push_back(res);
1068     }
1069
1070   this->record_weak_aliases(&object_symbols);
1071 }
1072
1073 // This is used to sort weak aliases.  We sort them first by section
1074 // index, then by offset, then by weak ahead of strong.
1075
1076 template<int size>
1077 class Weak_alias_sorter
1078 {
1079  public:
1080   bool operator()(const Sized_symbol<size>*, const Sized_symbol<size>*) const;
1081 };
1082
1083 template<int size>
1084 bool
1085 Weak_alias_sorter<size>::operator()(const Sized_symbol<size>* s1,
1086                                     const Sized_symbol<size>* s2) const
1087 {
1088   bool is_ordinary;
1089   unsigned int s1_shndx = s1->shndx(&is_ordinary);
1090   gold_assert(is_ordinary);
1091   unsigned int s2_shndx = s2->shndx(&is_ordinary);
1092   gold_assert(is_ordinary);
1093   if (s1_shndx != s2_shndx)
1094     return s1_shndx < s2_shndx;
1095
1096   if (s1->value() != s2->value())
1097     return s1->value() < s2->value();
1098   if (s1->binding() != s2->binding())
1099     {
1100       if (s1->binding() == elfcpp::STB_WEAK)
1101         return true;
1102       if (s2->binding() == elfcpp::STB_WEAK)
1103         return false;
1104     }
1105   return std::string(s1->name()) < std::string(s2->name());
1106 }
1107
1108 // SYMBOLS is a list of object symbols from a dynamic object.  Look
1109 // for any weak aliases, and record them so that if we add the weak
1110 // alias to the dynamic symbol table, we also add the corresponding
1111 // strong symbol.
1112
1113 template<int size>
1114 void
1115 Symbol_table::record_weak_aliases(std::vector<Sized_symbol<size>*>* symbols)
1116 {
1117   // Sort the vector by section index, then by offset, then by weak
1118   // ahead of strong.
1119   std::sort(symbols->begin(), symbols->end(), Weak_alias_sorter<size>());
1120
1121   // Walk through the vector.  For each weak definition, record
1122   // aliases.
1123   for (typename std::vector<Sized_symbol<size>*>::const_iterator p =
1124          symbols->begin();
1125        p != symbols->end();
1126        ++p)
1127     {
1128       if ((*p)->binding() != elfcpp::STB_WEAK)
1129         continue;
1130
1131       // Build a circular list of weak aliases.  Each symbol points to
1132       // the next one in the circular list.
1133
1134       Sized_symbol<size>* from_sym = *p;
1135       typename std::vector<Sized_symbol<size>*>::const_iterator q;
1136       for (q = p + 1; q != symbols->end(); ++q)
1137         {
1138           bool dummy;
1139           if ((*q)->shndx(&dummy) != from_sym->shndx(&dummy)
1140               || (*q)->value() != from_sym->value())
1141             break;
1142
1143           this->weak_aliases_[from_sym] = *q;
1144           from_sym->set_has_alias();
1145           from_sym = *q;
1146         }
1147
1148       if (from_sym != *p)
1149         {
1150           this->weak_aliases_[from_sym] = *p;
1151           from_sym->set_has_alias();
1152         }
1153
1154       p = q - 1;
1155     }
1156 }
1157
1158 // Create and return a specially defined symbol.  If ONLY_IF_REF is
1159 // true, then only create the symbol if there is a reference to it.
1160 // If this does not return NULL, it sets *POLDSYM to the existing
1161 // symbol if there is one.  This canonicalizes *PNAME and *PVERSION.
1162
1163 template<int size, bool big_endian>
1164 Sized_symbol<size>*
1165 Symbol_table::define_special_symbol(const char** pname, const char** pversion,
1166                                     bool only_if_ref,
1167                                     Sized_symbol<size>** poldsym)
1168 {
1169   Symbol* oldsym;
1170   Sized_symbol<size>* sym;
1171   bool add_to_table = false;
1172   typename Symbol_table_type::iterator add_loc = this->table_.end();
1173
1174   // If the caller didn't give us a version, see if we get one from
1175   // the version script.
1176   if (*pversion == NULL)
1177     {
1178       const std::string& v(this->version_script_.get_symbol_version(*pname));
1179       if (!v.empty())
1180         *pversion = v.c_str();
1181     }
1182
1183   if (only_if_ref)
1184     {
1185       oldsym = this->lookup(*pname, *pversion);
1186       if (oldsym == NULL || !oldsym->is_undefined())
1187         return NULL;
1188
1189       *pname = oldsym->name();
1190       *pversion = oldsym->version();
1191     }
1192   else
1193     {
1194       // Canonicalize NAME and VERSION.
1195       Stringpool::Key name_key;
1196       *pname = this->namepool_.add(*pname, true, &name_key);
1197
1198       Stringpool::Key version_key = 0;
1199       if (*pversion != NULL)
1200         *pversion = this->namepool_.add(*pversion, true, &version_key);
1201
1202       Symbol* const snull = NULL;
1203       std::pair<typename Symbol_table_type::iterator, bool> ins =
1204         this->table_.insert(std::make_pair(std::make_pair(name_key,
1205                                                           version_key),
1206                                            snull));
1207
1208       if (!ins.second)
1209         {
1210           // We already have a symbol table entry for NAME/VERSION.
1211           oldsym = ins.first->second;
1212           gold_assert(oldsym != NULL);
1213         }
1214       else
1215         {
1216           // We haven't seen this symbol before.
1217           gold_assert(ins.first->second == NULL);
1218           add_to_table = true;
1219           add_loc = ins.first;
1220           oldsym = NULL;
1221         }
1222     }
1223
1224   const Target& target = parameters->target();
1225   if (!target.has_make_symbol())
1226     sym = new Sized_symbol<size>();
1227   else
1228     {
1229       gold_assert(target.get_size() == size);
1230       gold_assert(target.is_big_endian() ? big_endian : !big_endian);
1231       typedef Sized_target<size, big_endian> My_target;
1232       const My_target* sized_target =
1233           static_cast<const My_target*>(&target);
1234       sym = sized_target->make_symbol();
1235       if (sym == NULL)
1236         return NULL;
1237     }
1238
1239   if (add_to_table)
1240     add_loc->second = sym;
1241   else
1242     gold_assert(oldsym != NULL);
1243
1244   *poldsym = this->get_sized_symbol<size>(oldsym);
1245
1246   return sym;
1247 }
1248
1249 // Define a symbol based on an Output_data.
1250
1251 Symbol*
1252 Symbol_table::define_in_output_data(const char* name,
1253                                     const char* version,
1254                                     Output_data* od,
1255                                     uint64_t value,
1256                                     uint64_t symsize,
1257                                     elfcpp::STT type,
1258                                     elfcpp::STB binding,
1259                                     elfcpp::STV visibility,
1260                                     unsigned char nonvis,
1261                                     bool offset_is_from_end,
1262                                     bool only_if_ref)
1263 {
1264   if (parameters->target().get_size() == 32)
1265     {
1266 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1267       return this->do_define_in_output_data<32>(name, version, od,
1268                                                 value, symsize, type, binding,
1269                                                 visibility, nonvis,
1270                                                 offset_is_from_end,
1271                                                 only_if_ref);
1272 #else
1273       gold_unreachable();
1274 #endif
1275     }
1276   else if (parameters->target().get_size() == 64)
1277     {
1278 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1279       return this->do_define_in_output_data<64>(name, version, od,
1280                                                 value, symsize, type, binding,
1281                                                 visibility, nonvis,
1282                                                 offset_is_from_end,
1283                                                 only_if_ref);
1284 #else
1285       gold_unreachable();
1286 #endif
1287     }
1288   else
1289     gold_unreachable();
1290 }
1291
1292 // Define a symbol in an Output_data, sized version.
1293
1294 template<int size>
1295 Sized_symbol<size>*
1296 Symbol_table::do_define_in_output_data(
1297     const char* name,
1298     const char* version,
1299     Output_data* od,
1300     typename elfcpp::Elf_types<size>::Elf_Addr value,
1301     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1302     elfcpp::STT type,
1303     elfcpp::STB binding,
1304     elfcpp::STV visibility,
1305     unsigned char nonvis,
1306     bool offset_is_from_end,
1307     bool only_if_ref)
1308 {
1309   Sized_symbol<size>* sym;
1310   Sized_symbol<size>* oldsym;
1311
1312   if (parameters->target().is_big_endian())
1313     {
1314 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1315       sym = this->define_special_symbol<size, true>(&name, &version,
1316                                                     only_if_ref, &oldsym);
1317 #else
1318       gold_unreachable();
1319 #endif
1320     }
1321   else
1322     {
1323 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1324       sym = this->define_special_symbol<size, false>(&name, &version,
1325                                                      only_if_ref, &oldsym);
1326 #else
1327       gold_unreachable();
1328 #endif
1329     }
1330
1331   if (sym == NULL)
1332     return NULL;
1333
1334   gold_assert(version == NULL || oldsym != NULL);
1335   sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
1336             offset_is_from_end);
1337
1338   if (oldsym == NULL)
1339     {
1340       if (binding == elfcpp::STB_LOCAL
1341           || this->version_script_.symbol_is_local(name))
1342         this->force_local(sym);
1343       return sym;
1344     }
1345
1346   if (Symbol_table::should_override_with_special(oldsym))
1347     this->override_with_special(oldsym, sym);
1348   delete sym;
1349   return oldsym;
1350 }
1351
1352 // Define a symbol based on an Output_segment.
1353
1354 Symbol*
1355 Symbol_table::define_in_output_segment(const char* name,
1356                                        const char* version, Output_segment* os,
1357                                        uint64_t value,
1358                                        uint64_t symsize,
1359                                        elfcpp::STT type,
1360                                        elfcpp::STB binding,
1361                                        elfcpp::STV visibility,
1362                                        unsigned char nonvis,
1363                                        Symbol::Segment_offset_base offset_base,
1364                                        bool only_if_ref)
1365 {
1366   if (parameters->target().get_size() == 32)
1367     {
1368 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1369       return this->do_define_in_output_segment<32>(name, version, os,
1370                                                    value, symsize, type,
1371                                                    binding, visibility, nonvis,
1372                                                    offset_base, only_if_ref);
1373 #else
1374       gold_unreachable();
1375 #endif
1376     }
1377   else if (parameters->target().get_size() == 64)
1378     {
1379 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1380       return this->do_define_in_output_segment<64>(name, version, os,
1381                                                    value, symsize, type,
1382                                                    binding, visibility, nonvis,
1383                                                    offset_base, only_if_ref);
1384 #else
1385       gold_unreachable();
1386 #endif
1387     }
1388   else
1389     gold_unreachable();
1390 }
1391
1392 // Define a symbol in an Output_segment, sized version.
1393
1394 template<int size>
1395 Sized_symbol<size>*
1396 Symbol_table::do_define_in_output_segment(
1397     const char* name,
1398     const char* version,
1399     Output_segment* os,
1400     typename elfcpp::Elf_types<size>::Elf_Addr value,
1401     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1402     elfcpp::STT type,
1403     elfcpp::STB binding,
1404     elfcpp::STV visibility,
1405     unsigned char nonvis,
1406     Symbol::Segment_offset_base offset_base,
1407     bool only_if_ref)
1408 {
1409   Sized_symbol<size>* sym;
1410   Sized_symbol<size>* oldsym;
1411
1412   if (parameters->target().is_big_endian())
1413     {
1414 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1415       sym = this->define_special_symbol<size, true>(&name, &version,
1416                                                     only_if_ref, &oldsym);
1417 #else
1418       gold_unreachable();
1419 #endif
1420     }
1421   else
1422     {
1423 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1424       sym = this->define_special_symbol<size, false>(&name, &version,
1425                                                      only_if_ref, &oldsym);
1426 #else
1427       gold_unreachable();
1428 #endif
1429     }
1430
1431   if (sym == NULL)
1432     return NULL;
1433
1434   gold_assert(version == NULL || oldsym != NULL);
1435   sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
1436             offset_base);
1437
1438   if (oldsym == NULL)
1439     {
1440       if (binding == elfcpp::STB_LOCAL
1441           || this->version_script_.symbol_is_local(name))
1442         this->force_local(sym);
1443       return sym;
1444     }
1445
1446   if (Symbol_table::should_override_with_special(oldsym))
1447     this->override_with_special(oldsym, sym);
1448   delete sym;
1449   return oldsym;
1450 }
1451
1452 // Define a special symbol with a constant value.  It is a multiple
1453 // definition error if this symbol is already defined.
1454
1455 Symbol*
1456 Symbol_table::define_as_constant(const char* name,
1457                                  const char* version,
1458                                  uint64_t value,
1459                                  uint64_t symsize,
1460                                  elfcpp::STT type,
1461                                  elfcpp::STB binding,
1462                                  elfcpp::STV visibility,
1463                                  unsigned char nonvis,
1464                                  bool only_if_ref,
1465                                  bool force_override)
1466 {
1467   if (parameters->target().get_size() == 32)
1468     {
1469 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
1470       return this->do_define_as_constant<32>(name, version, value,
1471                                              symsize, type, binding,
1472                                              visibility, nonvis, only_if_ref,
1473                                              force_override);
1474 #else
1475       gold_unreachable();
1476 #endif
1477     }
1478   else if (parameters->target().get_size() == 64)
1479     {
1480 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
1481       return this->do_define_as_constant<64>(name, version, value,
1482                                              symsize, type, binding,
1483                                              visibility, nonvis, only_if_ref,
1484                                              force_override);
1485 #else
1486       gold_unreachable();
1487 #endif
1488     }
1489   else
1490     gold_unreachable();
1491 }
1492
1493 // Define a symbol as a constant, sized version.
1494
1495 template<int size>
1496 Sized_symbol<size>*
1497 Symbol_table::do_define_as_constant(
1498     const char* name,
1499     const char* version,
1500     typename elfcpp::Elf_types<size>::Elf_Addr value,
1501     typename elfcpp::Elf_types<size>::Elf_WXword symsize,
1502     elfcpp::STT type,
1503     elfcpp::STB binding,
1504     elfcpp::STV visibility,
1505     unsigned char nonvis,
1506     bool only_if_ref,
1507     bool force_override)
1508 {
1509   Sized_symbol<size>* sym;
1510   Sized_symbol<size>* oldsym;
1511
1512   if (parameters->target().is_big_endian())
1513     {
1514 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG)
1515       sym = this->define_special_symbol<size, true>(&name, &version,
1516                                                     only_if_ref, &oldsym);
1517 #else
1518       gold_unreachable();
1519 #endif
1520     }
1521   else
1522     {
1523 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE)
1524       sym = this->define_special_symbol<size, false>(&name, &version,
1525                                                      only_if_ref, &oldsym);
1526 #else
1527       gold_unreachable();
1528 #endif
1529     }
1530
1531   if (sym == NULL)
1532     return NULL;
1533
1534   gold_assert(version == NULL || version == name || oldsym != NULL);
1535   sym->init(name, value, symsize, type, binding, visibility, nonvis);
1536
1537   if (oldsym == NULL)
1538     {
1539       // Version symbols are absolute symbols with name == version.
1540       // We don't want to force them to be local.
1541       if ((version == NULL
1542            || name != version
1543            || value != 0)
1544           && (binding == elfcpp::STB_LOCAL
1545               || this->version_script_.symbol_is_local(name)))
1546         this->force_local(sym);
1547       return sym;
1548     }
1549
1550   if (force_override || Symbol_table::should_override_with_special(oldsym))
1551     this->override_with_special(oldsym, sym);
1552   delete sym;
1553   return oldsym;
1554 }
1555
1556 // Define a set of symbols in output sections.
1557
1558 void
1559 Symbol_table::define_symbols(const Layout* layout, int count,
1560                              const Define_symbol_in_section* p,
1561                              bool only_if_ref)
1562 {
1563   for (int i = 0; i < count; ++i, ++p)
1564     {
1565       Output_section* os = layout->find_output_section(p->output_section);
1566       if (os != NULL)
1567         this->define_in_output_data(p->name, NULL, os, p->value,
1568                                     p->size, p->type, p->binding,
1569                                     p->visibility, p->nonvis,
1570                                     p->offset_is_from_end,
1571                                     only_if_ref || p->only_if_ref);
1572       else
1573         this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1574                                  p->binding, p->visibility, p->nonvis,
1575                                  only_if_ref || p->only_if_ref,
1576                                  false);
1577     }
1578 }
1579
1580 // Define a set of symbols in output segments.
1581
1582 void
1583 Symbol_table::define_symbols(const Layout* layout, int count,
1584                              const Define_symbol_in_segment* p,
1585                              bool only_if_ref)
1586 {
1587   for (int i = 0; i < count; ++i, ++p)
1588     {
1589       Output_segment* os = layout->find_output_segment(p->segment_type,
1590                                                        p->segment_flags_set,
1591                                                        p->segment_flags_clear);
1592       if (os != NULL)
1593         this->define_in_output_segment(p->name, NULL, os, p->value,
1594                                        p->size, p->type, p->binding,
1595                                        p->visibility, p->nonvis,
1596                                        p->offset_base,
1597                                        only_if_ref || p->only_if_ref);
1598       else
1599         this->define_as_constant(p->name, NULL, 0, p->size, p->type,
1600                                  p->binding, p->visibility, p->nonvis,
1601                                  only_if_ref || p->only_if_ref,
1602                                  false);
1603     }
1604 }
1605
1606 // Define CSYM using a COPY reloc.  POSD is the Output_data where the
1607 // symbol should be defined--typically a .dyn.bss section.  VALUE is
1608 // the offset within POSD.
1609
1610 template<int size>
1611 void
1612 Symbol_table::define_with_copy_reloc(
1613     Sized_symbol<size>* csym,
1614     Output_data* posd,
1615     typename elfcpp::Elf_types<size>::Elf_Addr value)
1616 {
1617   gold_assert(csym->is_from_dynobj());
1618   gold_assert(!csym->is_copied_from_dynobj());
1619   Object* object = csym->object();
1620   gold_assert(object->is_dynamic());
1621   Dynobj* dynobj = static_cast<Dynobj*>(object);
1622
1623   // Our copied variable has to override any variable in a shared
1624   // library.
1625   elfcpp::STB binding = csym->binding();
1626   if (binding == elfcpp::STB_WEAK)
1627     binding = elfcpp::STB_GLOBAL;
1628
1629   this->define_in_output_data(csym->name(), csym->version(),
1630                               posd, value, csym->symsize(),
1631                               csym->type(), binding,
1632                               csym->visibility(), csym->nonvis(),
1633                               false, false);
1634
1635   csym->set_is_copied_from_dynobj();
1636   csym->set_needs_dynsym_entry();
1637
1638   this->copied_symbol_dynobjs_[csym] = dynobj;
1639
1640   // We have now defined all aliases, but we have not entered them all
1641   // in the copied_symbol_dynobjs_ map.
1642   if (csym->has_alias())
1643     {
1644       Symbol* sym = csym;
1645       while (true)
1646         {
1647           sym = this->weak_aliases_[sym];
1648           if (sym == csym)
1649             break;
1650           gold_assert(sym->output_data() == posd);
1651
1652           sym->set_is_copied_from_dynobj();
1653           this->copied_symbol_dynobjs_[sym] = dynobj;
1654         }
1655     }
1656 }
1657
1658 // SYM is defined using a COPY reloc.  Return the dynamic object where
1659 // the original definition was found.
1660
1661 Dynobj*
1662 Symbol_table::get_copy_source(const Symbol* sym) const
1663 {
1664   gold_assert(sym->is_copied_from_dynobj());
1665   Copied_symbol_dynobjs::const_iterator p =
1666     this->copied_symbol_dynobjs_.find(sym);
1667   gold_assert(p != this->copied_symbol_dynobjs_.end());
1668   return p->second;
1669 }
1670
1671 // Set the dynamic symbol indexes.  INDEX is the index of the first
1672 // global dynamic symbol.  Pointers to the symbols are stored into the
1673 // vector SYMS.  The names are added to DYNPOOL.  This returns an
1674 // updated dynamic symbol index.
1675
1676 unsigned int
1677 Symbol_table::set_dynsym_indexes(unsigned int index,
1678                                  std::vector<Symbol*>* syms,
1679                                  Stringpool* dynpool,
1680                                  Versions* versions)
1681 {
1682   for (Symbol_table_type::iterator p = this->table_.begin();
1683        p != this->table_.end();
1684        ++p)
1685     {
1686       Symbol* sym = p->second;
1687
1688       // Note that SYM may already have a dynamic symbol index, since
1689       // some symbols appear more than once in the symbol table, with
1690       // and without a version.
1691
1692       if (!sym->should_add_dynsym_entry())
1693         sym->set_dynsym_index(-1U);
1694       else if (!sym->has_dynsym_index())
1695         {
1696           sym->set_dynsym_index(index);
1697           ++index;
1698           syms->push_back(sym);
1699           dynpool->add(sym->name(), false, NULL);
1700
1701           // Record any version information.
1702           if (sym->version() != NULL)
1703             versions->record_version(this, dynpool, sym);
1704         }
1705     }
1706
1707   // Finish up the versions.  In some cases this may add new dynamic
1708   // symbols.
1709   index = versions->finalize(this, index, syms);
1710
1711   return index;
1712 }
1713
1714 // Set the final values for all the symbols.  The index of the first
1715 // global symbol in the output file is *PLOCAL_SYMCOUNT.  Record the
1716 // file offset OFF.  Add their names to POOL.  Return the new file
1717 // offset.  Update *PLOCAL_SYMCOUNT if necessary.
1718
1719 off_t
1720 Symbol_table::finalize(off_t off, off_t dynoff, size_t dyn_global_index,
1721                        size_t dyncount, Stringpool* pool,
1722                        unsigned int *plocal_symcount)
1723 {
1724   off_t ret;
1725
1726   gold_assert(*plocal_symcount != 0);
1727   this->first_global_index_ = *plocal_symcount;
1728
1729   this->dynamic_offset_ = dynoff;
1730   this->first_dynamic_global_index_ = dyn_global_index;
1731   this->dynamic_count_ = dyncount;
1732
1733   if (parameters->target().get_size() == 32)
1734     {
1735 #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_32_LITTLE)
1736       ret = this->sized_finalize<32>(off, pool, plocal_symcount);
1737 #else
1738       gold_unreachable();
1739 #endif
1740     }
1741   else if (parameters->target().get_size() == 64)
1742     {
1743 #if defined(HAVE_TARGET_64_BIG) || defined(HAVE_TARGET_64_LITTLE)
1744       ret = this->sized_finalize<64>(off, pool, plocal_symcount);
1745 #else
1746       gold_unreachable();
1747 #endif
1748     }
1749   else
1750     gold_unreachable();
1751
1752   // Now that we have the final symbol table, we can reliably note
1753   // which symbols should get warnings.
1754   this->warnings_.note_warnings(this);
1755
1756   return ret;
1757 }
1758
1759 // SYM is going into the symbol table at *PINDEX.  Add the name to
1760 // POOL, update *PINDEX and *POFF.
1761
1762 template<int size>
1763 void
1764 Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
1765                                   unsigned int* pindex, off_t* poff)
1766 {
1767   sym->set_symtab_index(*pindex);
1768   pool->add(sym->name(), false, NULL);
1769   ++*pindex;
1770   *poff += elfcpp::Elf_sizes<size>::sym_size;
1771 }
1772
1773 // Set the final value for all the symbols.  This is called after
1774 // Layout::finalize, so all the output sections have their final
1775 // address.
1776
1777 template<int size>
1778 off_t
1779 Symbol_table::sized_finalize(off_t off, Stringpool* pool,
1780                              unsigned int* plocal_symcount)
1781 {
1782   off = align_address(off, size >> 3);
1783   this->offset_ = off;
1784
1785   unsigned int index = *plocal_symcount;
1786   const unsigned int orig_index = index;
1787
1788   // First do all the symbols which have been forced to be local, as
1789   // they must appear before all global symbols.
1790   for (Forced_locals::iterator p = this->forced_locals_.begin();
1791        p != this->forced_locals_.end();
1792        ++p)
1793     {
1794       Symbol* sym = *p;
1795       gold_assert(sym->is_forced_local());
1796       if (this->sized_finalize_symbol<size>(sym))
1797         {
1798           this->add_to_final_symtab<size>(sym, pool, &index, &off);
1799           ++*plocal_symcount;
1800         }
1801     }
1802
1803   // Now do all the remaining symbols.
1804   for (Symbol_table_type::iterator p = this->table_.begin();
1805        p != this->table_.end();
1806        ++p)
1807     {
1808       Symbol* sym = p->second;
1809       if (this->sized_finalize_symbol<size>(sym))
1810         this->add_to_final_symtab<size>(sym, pool, &index, &off);
1811     }
1812
1813   this->output_count_ = index - orig_index;
1814
1815   return off;
1816 }
1817
1818 // Finalize the symbol SYM.  This returns true if the symbol should be
1819 // added to the symbol table, false otherwise.
1820
1821 template<int size>
1822 bool
1823 Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
1824 {
1825   Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(unsized_sym);
1826
1827   // The default version of a symbol may appear twice in the symbol
1828   // table.  We only need to finalize it once.
1829   if (sym->has_symtab_index())
1830     return false;
1831
1832   if (!sym->in_reg())
1833     {
1834       gold_assert(!sym->has_symtab_index());
1835       sym->set_symtab_index(-1U);
1836       gold_assert(sym->dynsym_index() == -1U);
1837       return false;
1838     }
1839
1840   typename Sized_symbol<size>::Value_type value;
1841
1842   switch (sym->source())
1843     {
1844     case Symbol::FROM_OBJECT:
1845       {
1846         bool is_ordinary;
1847         unsigned int shndx = sym->shndx(&is_ordinary);
1848
1849         // FIXME: We need some target specific support here.
1850         if (!is_ordinary
1851             && shndx != elfcpp::SHN_ABS
1852             && shndx != elfcpp::SHN_COMMON)
1853           {
1854             gold_error(_("%s: unsupported symbol section 0x%x"),
1855                        sym->demangled_name().c_str(), shndx);
1856             shndx = elfcpp::SHN_UNDEF;
1857           }
1858
1859         Object* symobj = sym->object();
1860         if (symobj->is_dynamic())
1861           {
1862             value = 0;
1863             shndx = elfcpp::SHN_UNDEF;
1864           }
1865         else if (shndx == elfcpp::SHN_UNDEF)
1866           value = 0;
1867         else if (!is_ordinary
1868                  && (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON))
1869           value = sym->value();
1870         else
1871           {
1872             Relobj* relobj = static_cast<Relobj*>(symobj);
1873             section_offset_type secoff;
1874             Output_section* os = relobj->output_section(shndx, &secoff);
1875
1876             if (os == NULL)
1877               {
1878                 sym->set_symtab_index(-1U);
1879                 gold_assert(sym->dynsym_index() == -1U);
1880                 return false;
1881               }
1882
1883             if (sym->type() == elfcpp::STT_TLS)
1884               value = sym->value() + os->tls_offset() + secoff;
1885             else
1886               value = sym->value() + os->address() + secoff;
1887           }
1888       }
1889       break;
1890
1891     case Symbol::IN_OUTPUT_DATA:
1892       {
1893         Output_data* od = sym->output_data();
1894         value = sym->value();
1895         if (sym->type() != elfcpp::STT_TLS)
1896           value += od->address();
1897         else
1898           {
1899             Output_section* os = od->output_section();
1900             gold_assert(os != NULL);
1901             value += os->tls_offset() + (od->address() - os->address());
1902           }
1903         if (sym->offset_is_from_end())
1904           value += od->data_size();
1905       }
1906       break;
1907
1908     case Symbol::IN_OUTPUT_SEGMENT:
1909       {
1910         Output_segment* os = sym->output_segment();
1911         value = sym->value();
1912         if (sym->type() != elfcpp::STT_TLS)
1913           value += os->vaddr();
1914         switch (sym->offset_base())
1915           {
1916           case Symbol::SEGMENT_START:
1917             break;
1918           case Symbol::SEGMENT_END:
1919             value += os->memsz();
1920             break;
1921           case Symbol::SEGMENT_BSS:
1922             value += os->filesz();
1923             break;
1924           default:
1925             gold_unreachable();
1926           }
1927       }
1928       break;
1929
1930     case Symbol::CONSTANT:
1931       value = sym->value();
1932       break;
1933
1934     default:
1935       gold_unreachable();
1936     }
1937
1938   sym->set_value(value);
1939
1940   if (parameters->options().strip_all())
1941     {
1942       sym->set_symtab_index(-1U);
1943       return false;
1944     }
1945
1946   return true;
1947 }
1948
1949 // Write out the global symbols.
1950
1951 void
1952 Symbol_table::write_globals(const Input_objects* input_objects,
1953                             const Stringpool* sympool,
1954                             const Stringpool* dynpool,
1955                             Output_symtab_xindex* symtab_xindex,
1956                             Output_symtab_xindex* dynsym_xindex,
1957                             Output_file* of) const
1958 {
1959   switch (parameters->size_and_endianness())
1960     {
1961 #ifdef HAVE_TARGET_32_LITTLE
1962     case Parameters::TARGET_32_LITTLE:
1963       this->sized_write_globals<32, false>(input_objects, sympool,
1964                                            dynpool, symtab_xindex,
1965                                            dynsym_xindex, of);
1966       break;
1967 #endif
1968 #ifdef HAVE_TARGET_32_BIG
1969     case Parameters::TARGET_32_BIG:
1970       this->sized_write_globals<32, true>(input_objects, sympool,
1971                                           dynpool, symtab_xindex,
1972                                           dynsym_xindex, of);
1973       break;
1974 #endif
1975 #ifdef HAVE_TARGET_64_LITTLE
1976     case Parameters::TARGET_64_LITTLE:
1977       this->sized_write_globals<64, false>(input_objects, sympool,
1978                                            dynpool, symtab_xindex,
1979                                            dynsym_xindex, of);
1980       break;
1981 #endif
1982 #ifdef HAVE_TARGET_64_BIG
1983     case Parameters::TARGET_64_BIG:
1984       this->sized_write_globals<64, true>(input_objects, sympool,
1985                                           dynpool, symtab_xindex,
1986                                           dynsym_xindex, of);
1987       break;
1988 #endif
1989     default:
1990       gold_unreachable();
1991     }
1992 }
1993
1994 // Write out the global symbols.
1995
1996 template<int size, bool big_endian>
1997 void
1998 Symbol_table::sized_write_globals(const Input_objects* input_objects,
1999                                   const Stringpool* sympool,
2000                                   const Stringpool* dynpool,
2001                                   Output_symtab_xindex* symtab_xindex,
2002                                   Output_symtab_xindex* dynsym_xindex,
2003                                   Output_file* of) const
2004 {
2005   const Target& target = parameters->target();
2006
2007   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2008
2009   const unsigned int output_count = this->output_count_;
2010   const section_size_type oview_size = output_count * sym_size;
2011   const unsigned int first_global_index = this->first_global_index_;
2012   unsigned char* psyms;
2013   if (this->offset_ == 0 || output_count == 0)
2014     psyms = NULL;
2015   else
2016     psyms = of->get_output_view(this->offset_, oview_size);
2017
2018   const unsigned int dynamic_count = this->dynamic_count_;
2019   const section_size_type dynamic_size = dynamic_count * sym_size;
2020   const unsigned int first_dynamic_global_index =
2021     this->first_dynamic_global_index_;
2022   unsigned char* dynamic_view;
2023   if (this->dynamic_offset_ == 0 || dynamic_count == 0)
2024     dynamic_view = NULL;
2025   else
2026     dynamic_view = of->get_output_view(this->dynamic_offset_, dynamic_size);
2027
2028   for (Symbol_table_type::const_iterator p = this->table_.begin();
2029        p != this->table_.end();
2030        ++p)
2031     {
2032       Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
2033
2034       // Possibly warn about unresolved symbols in shared libraries.
2035       this->warn_about_undefined_dynobj_symbol(input_objects, sym);
2036
2037       unsigned int sym_index = sym->symtab_index();
2038       unsigned int dynsym_index;
2039       if (dynamic_view == NULL)
2040         dynsym_index = -1U;
2041       else
2042         dynsym_index = sym->dynsym_index();
2043
2044       if (sym_index == -1U && dynsym_index == -1U)
2045         {
2046           // This symbol is not included in the output file.
2047           continue;
2048         }
2049
2050       unsigned int shndx;
2051       typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
2052       typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
2053       switch (sym->source())
2054         {
2055         case Symbol::FROM_OBJECT:
2056           {
2057             bool is_ordinary;
2058             unsigned int in_shndx = sym->shndx(&is_ordinary);
2059
2060             // FIXME: We need some target specific support here.
2061             if (!is_ordinary
2062                 && in_shndx != elfcpp::SHN_ABS
2063                 && in_shndx != elfcpp::SHN_COMMON)
2064               {
2065                 gold_error(_("%s: unsupported symbol section 0x%x"),
2066                            sym->demangled_name().c_str(), in_shndx);
2067                 shndx = in_shndx;
2068               }
2069             else
2070               {
2071                 Object* symobj = sym->object();
2072                 if (symobj->is_dynamic())
2073                   {
2074                     if (sym->needs_dynsym_value())
2075                       dynsym_value = target.dynsym_value(sym);
2076                     shndx = elfcpp::SHN_UNDEF;
2077                   }
2078                 else if (in_shndx == elfcpp::SHN_UNDEF
2079                          || (!is_ordinary
2080                              && (in_shndx == elfcpp::SHN_ABS
2081                                  || in_shndx == elfcpp::SHN_COMMON)))
2082                   shndx = in_shndx;
2083                 else
2084                   {
2085                     Relobj* relobj = static_cast<Relobj*>(symobj);
2086                     section_offset_type secoff;
2087                     Output_section* os = relobj->output_section(in_shndx,
2088                                                                 &secoff);
2089                     gold_assert(os != NULL);
2090                     shndx = os->out_shndx();
2091
2092                     if (shndx >= elfcpp::SHN_LORESERVE)
2093                       {
2094                         if (sym_index != -1U)
2095                           symtab_xindex->add(sym_index, shndx);
2096                         if (dynsym_index != -1U)
2097                           dynsym_xindex->add(dynsym_index, shndx);
2098                         shndx = elfcpp::SHN_XINDEX;
2099                       }
2100
2101                     // In object files symbol values are section
2102                     // relative.
2103                     if (parameters->options().relocatable())
2104                       sym_value -= os->address();
2105                   }
2106               }
2107           }
2108           break;
2109
2110         case Symbol::IN_OUTPUT_DATA:
2111           shndx = sym->output_data()->out_shndx();
2112           if (shndx >= elfcpp::SHN_LORESERVE)
2113             {
2114               if (sym_index != -1U)
2115                 symtab_xindex->add(sym_index, shndx);
2116               if (dynsym_index != -1U)
2117                 dynsym_xindex->add(dynsym_index, shndx);
2118               shndx = elfcpp::SHN_XINDEX;
2119             }
2120           break;
2121
2122         case Symbol::IN_OUTPUT_SEGMENT:
2123           shndx = elfcpp::SHN_ABS;
2124           break;
2125
2126         case Symbol::CONSTANT:
2127           shndx = elfcpp::SHN_ABS;
2128           break;
2129
2130         default:
2131           gold_unreachable();
2132         }
2133
2134       if (sym_index != -1U)
2135         {
2136           sym_index -= first_global_index;
2137           gold_assert(sym_index < output_count);
2138           unsigned char* ps = psyms + (sym_index * sym_size);
2139           this->sized_write_symbol<size, big_endian>(sym, sym_value, shndx,
2140                                                      sympool, ps);
2141         }
2142
2143       if (dynsym_index != -1U)
2144         {
2145           dynsym_index -= first_dynamic_global_index;
2146           gold_assert(dynsym_index < dynamic_count);
2147           unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
2148           this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
2149                                                      dynpool, pd);
2150         }
2151     }
2152
2153   of->write_output_view(this->offset_, oview_size, psyms);
2154   if (dynamic_view != NULL)
2155     of->write_output_view(this->dynamic_offset_, dynamic_size, dynamic_view);
2156 }
2157
2158 // Write out the symbol SYM, in section SHNDX, to P.  POOL is the
2159 // strtab holding the name.
2160
2161 template<int size, bool big_endian>
2162 void
2163 Symbol_table::sized_write_symbol(
2164     Sized_symbol<size>* sym,
2165     typename elfcpp::Elf_types<size>::Elf_Addr value,
2166     unsigned int shndx,
2167     const Stringpool* pool,
2168     unsigned char* p) const
2169 {
2170   elfcpp::Sym_write<size, big_endian> osym(p);
2171   osym.put_st_name(pool->get_offset(sym->name()));
2172   osym.put_st_value(value);
2173   osym.put_st_size(sym->symsize());
2174   // A version script may have overridden the default binding.
2175   if (sym->is_forced_local())
2176     osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL, sym->type()));
2177   else
2178     osym.put_st_info(elfcpp::elf_st_info(sym->binding(), sym->type()));
2179   osym.put_st_other(elfcpp::elf_st_other(sym->visibility(), sym->nonvis()));
2180   osym.put_st_shndx(shndx);
2181 }
2182
2183 // Check for unresolved symbols in shared libraries.  This is
2184 // controlled by the --allow-shlib-undefined option.
2185
2186 // We only warn about libraries for which we have seen all the
2187 // DT_NEEDED entries.  We don't try to track down DT_NEEDED entries
2188 // which were not seen in this link.  If we didn't see a DT_NEEDED
2189 // entry, we aren't going to be able to reliably report whether the
2190 // symbol is undefined.
2191
2192 // We also don't warn about libraries found in the system library
2193 // directory (the directory were we find libc.so); we assume that
2194 // those libraries are OK.  This heuristic avoids problems in
2195 // GNU/Linux, in which -ldl can have undefined references satisfied by
2196 // ld-linux.so.
2197
2198 inline void
2199 Symbol_table::warn_about_undefined_dynobj_symbol(
2200     const Input_objects* input_objects,
2201     Symbol* sym) const
2202 {
2203   bool dummy;
2204   if (sym->source() == Symbol::FROM_OBJECT
2205       && sym->object()->is_dynamic()
2206       && sym->shndx(&dummy) == elfcpp::SHN_UNDEF
2207       && sym->binding() != elfcpp::STB_WEAK
2208       && !parameters->options().allow_shlib_undefined()
2209       && !parameters->target().is_defined_by_abi(sym)
2210       && !input_objects->found_in_system_library_directory(sym->object()))
2211     {
2212       // A very ugly cast.
2213       Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
2214       if (!dynobj->has_unknown_needed_entries())
2215         gold_error(_("%s: undefined reference to '%s'"),
2216                    sym->object()->name().c_str(),
2217                    sym->demangled_name().c_str());
2218     }
2219 }
2220
2221 // Write out a section symbol.  Return the update offset.
2222
2223 void
2224 Symbol_table::write_section_symbol(const Output_section *os,
2225                                    Output_symtab_xindex* symtab_xindex,
2226                                    Output_file* of,
2227                                    off_t offset) const
2228 {
2229   switch (parameters->size_and_endianness())
2230     {
2231 #ifdef HAVE_TARGET_32_LITTLE
2232     case Parameters::TARGET_32_LITTLE:
2233       this->sized_write_section_symbol<32, false>(os, symtab_xindex, of,
2234                                                   offset);
2235       break;
2236 #endif
2237 #ifdef HAVE_TARGET_32_BIG
2238     case Parameters::TARGET_32_BIG:
2239       this->sized_write_section_symbol<32, true>(os, symtab_xindex, of,
2240                                                  offset);
2241       break;
2242 #endif
2243 #ifdef HAVE_TARGET_64_LITTLE
2244     case Parameters::TARGET_64_LITTLE:
2245       this->sized_write_section_symbol<64, false>(os, symtab_xindex, of,
2246                                                   offset);
2247       break;
2248 #endif
2249 #ifdef HAVE_TARGET_64_BIG
2250     case Parameters::TARGET_64_BIG:
2251       this->sized_write_section_symbol<64, true>(os, symtab_xindex, of,
2252                                                  offset);
2253       break;
2254 #endif
2255     default:
2256       gold_unreachable();
2257     }
2258 }
2259
2260 // Write out a section symbol, specialized for size and endianness.
2261
2262 template<int size, bool big_endian>
2263 void
2264 Symbol_table::sized_write_section_symbol(const Output_section* os,
2265                                          Output_symtab_xindex* symtab_xindex,
2266                                          Output_file* of,
2267                                          off_t offset) const
2268 {
2269   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
2270
2271   unsigned char* pov = of->get_output_view(offset, sym_size);
2272
2273   elfcpp::Sym_write<size, big_endian> osym(pov);
2274   osym.put_st_name(0);
2275   osym.put_st_value(os->address());
2276   osym.put_st_size(0);
2277   osym.put_st_info(elfcpp::elf_st_info(elfcpp::STB_LOCAL,
2278                                        elfcpp::STT_SECTION));
2279   osym.put_st_other(elfcpp::elf_st_other(elfcpp::STV_DEFAULT, 0));
2280
2281   unsigned int shndx = os->out_shndx();
2282   if (shndx >= elfcpp::SHN_LORESERVE)
2283     {
2284       symtab_xindex->add(os->symtab_index(), shndx);
2285       shndx = elfcpp::SHN_XINDEX;
2286     }
2287   osym.put_st_shndx(shndx);
2288
2289   of->write_output_view(offset, sym_size, pov);
2290 }
2291
2292 // Print statistical information to stderr.  This is used for --stats.
2293
2294 void
2295 Symbol_table::print_stats() const
2296 {
2297 #if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
2298   fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
2299           program_name, this->table_.size(), this->table_.bucket_count());
2300 #else
2301   fprintf(stderr, _("%s: symbol table entries: %zu\n"),
2302           program_name, this->table_.size());
2303 #endif
2304   this->namepool_.print_stats("symbol table stringpool");
2305 }
2306
2307 // We check for ODR violations by looking for symbols with the same
2308 // name for which the debugging information reports that they were
2309 // defined in different source locations.  When comparing the source
2310 // location, we consider instances with the same base filename and
2311 // line number to be the same.  This is because different object
2312 // files/shared libraries can include the same header file using
2313 // different paths, and we don't want to report an ODR violation in
2314 // that case.
2315
2316 // This struct is used to compare line information, as returned by
2317 // Dwarf_line_info::one_addr2line.  It implements a < comparison
2318 // operator used with std::set.
2319
2320 struct Odr_violation_compare
2321 {
2322   bool
2323   operator()(const std::string& s1, const std::string& s2) const
2324   {
2325     std::string::size_type pos1 = s1.rfind('/');
2326     std::string::size_type pos2 = s2.rfind('/');
2327     if (pos1 == std::string::npos
2328         || pos2 == std::string::npos)
2329       return s1 < s2;
2330     return s1.compare(pos1, std::string::npos,
2331                       s2, pos2, std::string::npos) < 0;
2332   }
2333 };
2334
2335 // Check candidate_odr_violations_ to find symbols with the same name
2336 // but apparently different definitions (different source-file/line-no).
2337
2338 void
2339 Symbol_table::detect_odr_violations(const Task* task,
2340                                     const char* output_file_name) const
2341 {
2342   for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
2343        it != candidate_odr_violations_.end();
2344        ++it)
2345     {
2346       const char* symbol_name = it->first;
2347       // We use a sorted set so the output is deterministic.
2348       std::set<std::string, Odr_violation_compare> line_nums;
2349
2350       for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
2351                locs = it->second.begin();
2352            locs != it->second.end();
2353            ++locs)
2354         {
2355           // We need to lock the object in order to read it.  This
2356           // means that we have to run in a singleton Task.  If we
2357           // want to run this in a general Task for better
2358           // performance, we will need one Task for object, plus
2359           // appropriate locking to ensure that we don't conflict with
2360           // other uses of the object.  Also note, one_addr2line is not
2361           // currently thread-safe.
2362           Task_lock_obj<Object> tl(task, locs->object);
2363           // 16 is the size of the object-cache that one_addr2line should use.
2364           std::string lineno = Dwarf_line_info::one_addr2line(
2365               locs->object, locs->shndx, locs->offset, 16);
2366           if (!lineno.empty())
2367             line_nums.insert(lineno);
2368         }
2369
2370       if (line_nums.size() > 1)
2371         {
2372           gold_warning(_("while linking %s: symbol '%s' defined in multiple "
2373                          "places (possible ODR violation):"),
2374                        output_file_name, demangle(symbol_name).c_str());
2375           for (std::set<std::string>::const_iterator it2 = line_nums.begin();
2376                it2 != line_nums.end();
2377                ++it2)
2378             fprintf(stderr, "  %s\n", it2->c_str());
2379         }
2380     }
2381   // We only call one_addr2line() in this function, so we can clear its cache.
2382   Dwarf_line_info::clear_addr2line_cache();
2383 }
2384
2385 // Warnings functions.
2386
2387 // Add a new warning.
2388
2389 void
2390 Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
2391                       const std::string& warning)
2392 {
2393   name = symtab->canonicalize_name(name);
2394   this->warnings_[name].set(obj, warning);
2395 }
2396
2397 // Look through the warnings and mark the symbols for which we should
2398 // warn.  This is called during Layout::finalize when we know the
2399 // sources for all the symbols.
2400
2401 void
2402 Warnings::note_warnings(Symbol_table* symtab)
2403 {
2404   for (Warning_table::iterator p = this->warnings_.begin();
2405        p != this->warnings_.end();
2406        ++p)
2407     {
2408       Symbol* sym = symtab->lookup(p->first, NULL);
2409       if (sym != NULL
2410           && sym->source() == Symbol::FROM_OBJECT
2411           && sym->object() == p->second.object)
2412         sym->set_has_warning();
2413     }
2414 }
2415
2416 // Issue a warning.  This is called when we see a relocation against a
2417 // symbol for which has a warning.
2418
2419 template<int size, bool big_endian>
2420 void
2421 Warnings::issue_warning(const Symbol* sym,
2422                         const Relocate_info<size, big_endian>* relinfo,
2423                         size_t relnum, off_t reloffset) const
2424 {
2425   gold_assert(sym->has_warning());
2426   Warning_table::const_iterator p = this->warnings_.find(sym->name());
2427   gold_assert(p != this->warnings_.end());
2428   gold_warning_at_location(relinfo, relnum, reloffset,
2429                            "%s", p->second.text.c_str());
2430 }
2431
2432 // Instantiate the templates we need.  We could use the configure
2433 // script to restrict this to only the ones needed for implemented
2434 // targets.
2435
2436 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2437 template
2438 void
2439 Sized_symbol<32>::allocate_common(Output_data*, Value_type);
2440 #endif
2441
2442 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2443 template
2444 void
2445 Sized_symbol<64>::allocate_common(Output_data*, Value_type);
2446 #endif
2447
2448 #ifdef HAVE_TARGET_32_LITTLE
2449 template
2450 void
2451 Symbol_table::add_from_relobj<32, false>(
2452     Sized_relobj<32, false>* relobj,
2453     const unsigned char* syms,
2454     size_t count,
2455     size_t symndx_offset,
2456     const char* sym_names,
2457     size_t sym_name_size,
2458     Sized_relobj<32, true>::Symbols* sympointers);
2459 #endif
2460
2461 #ifdef HAVE_TARGET_32_BIG
2462 template
2463 void
2464 Symbol_table::add_from_relobj<32, true>(
2465     Sized_relobj<32, true>* relobj,
2466     const unsigned char* syms,
2467     size_t count,
2468     size_t symndx_offset,
2469     const char* sym_names,
2470     size_t sym_name_size,
2471     Sized_relobj<32, false>::Symbols* sympointers);
2472 #endif
2473
2474 #ifdef HAVE_TARGET_64_LITTLE
2475 template
2476 void
2477 Symbol_table::add_from_relobj<64, false>(
2478     Sized_relobj<64, false>* relobj,
2479     const unsigned char* syms,
2480     size_t count,
2481     size_t symndx_offset,
2482     const char* sym_names,
2483     size_t sym_name_size,
2484     Sized_relobj<64, true>::Symbols* sympointers);
2485 #endif
2486
2487 #ifdef HAVE_TARGET_64_BIG
2488 template
2489 void
2490 Symbol_table::add_from_relobj<64, true>(
2491     Sized_relobj<64, true>* relobj,
2492     const unsigned char* syms,
2493     size_t count,
2494     size_t symndx_offset,
2495     const char* sym_names,
2496     size_t sym_name_size,
2497     Sized_relobj<64, false>::Symbols* sympointers);
2498 #endif
2499
2500 #ifdef HAVE_TARGET_32_LITTLE
2501 template
2502 void
2503 Symbol_table::add_from_dynobj<32, false>(
2504     Sized_dynobj<32, false>* dynobj,
2505     const unsigned char* syms,
2506     size_t count,
2507     const char* sym_names,
2508     size_t sym_name_size,
2509     const unsigned char* versym,
2510     size_t versym_size,
2511     const std::vector<const char*>* version_map);
2512 #endif
2513
2514 #ifdef HAVE_TARGET_32_BIG
2515 template
2516 void
2517 Symbol_table::add_from_dynobj<32, true>(
2518     Sized_dynobj<32, true>* dynobj,
2519     const unsigned char* syms,
2520     size_t count,
2521     const char* sym_names,
2522     size_t sym_name_size,
2523     const unsigned char* versym,
2524     size_t versym_size,
2525     const std::vector<const char*>* version_map);
2526 #endif
2527
2528 #ifdef HAVE_TARGET_64_LITTLE
2529 template
2530 void
2531 Symbol_table::add_from_dynobj<64, false>(
2532     Sized_dynobj<64, false>* dynobj,
2533     const unsigned char* syms,
2534     size_t count,
2535     const char* sym_names,
2536     size_t sym_name_size,
2537     const unsigned char* versym,
2538     size_t versym_size,
2539     const std::vector<const char*>* version_map);
2540 #endif
2541
2542 #ifdef HAVE_TARGET_64_BIG
2543 template
2544 void
2545 Symbol_table::add_from_dynobj<64, true>(
2546     Sized_dynobj<64, true>* dynobj,
2547     const unsigned char* syms,
2548     size_t count,
2549     const char* sym_names,
2550     size_t sym_name_size,
2551     const unsigned char* versym,
2552     size_t versym_size,
2553     const std::vector<const char*>* version_map);
2554 #endif
2555
2556 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
2557 template
2558 void
2559 Symbol_table::define_with_copy_reloc<32>(
2560     Sized_symbol<32>* sym,
2561     Output_data* posd,
2562     elfcpp::Elf_types<32>::Elf_Addr value);
2563 #endif
2564
2565 #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
2566 template
2567 void
2568 Symbol_table::define_with_copy_reloc<64>(
2569     Sized_symbol<64>* sym,
2570     Output_data* posd,
2571     elfcpp::Elf_types<64>::Elf_Addr value);
2572 #endif
2573
2574 #ifdef HAVE_TARGET_32_LITTLE
2575 template
2576 void
2577 Warnings::issue_warning<32, false>(const Symbol* sym,
2578                                    const Relocate_info<32, false>* relinfo,
2579                                    size_t relnum, off_t reloffset) const;
2580 #endif
2581
2582 #ifdef HAVE_TARGET_32_BIG
2583 template
2584 void
2585 Warnings::issue_warning<32, true>(const Symbol* sym,
2586                                   const Relocate_info<32, true>* relinfo,
2587                                   size_t relnum, off_t reloffset) const;
2588 #endif
2589
2590 #ifdef HAVE_TARGET_64_LITTLE
2591 template
2592 void
2593 Warnings::issue_warning<64, false>(const Symbol* sym,
2594                                    const Relocate_info<64, false>* relinfo,
2595                                    size_t relnum, off_t reloffset) const;
2596 #endif
2597
2598 #ifdef HAVE_TARGET_64_BIG
2599 template
2600 void
2601 Warnings::issue_warning<64, true>(const Symbol* sym,
2602                                   const Relocate_info<64, true>* relinfo,
2603                                   size_t relnum, off_t reloffset) const;
2604 #endif
2605
2606 } // End namespace gold.