gold/cref.cc

   1 // cref.cc -- cross reference for gold
   2
   3 // Copyright (C) 2008-2019 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 <cerrno>
  26 #include <cstdio>
  27 #include <cstring>
  28 #include <map>
  29 #include <string>
  30 #include <vector>
  31
  32 #include "object.h"
  33 #include "archive.h"
  34 #include "symtab.h"
  35 #include "cref.h"
  36
  37 namespace gold
  38 {
  39
  40 // Class Cref_inputs.  This is used to hold the list of input files
  41 // for cross referencing.
  42
  43 class Cref_inputs
  44 {
  45  public:
  46   Cref_inputs()
  47     : objects_(), archives_(), current_(&this->objects_)
  48   { }
  49
  50   // Add an input object file.
  51   void
  52   add_object(Object* object);
  53
  54   // Start adding an archive.  We support nested archives for future
  55   // flexibility.
  56   void
  57   add_archive_start(Archive*);
  58
  59   // Finish adding an archive.
  60   void
  61   add_archive_stop(Archive*);
  62
  63   // Report symbol counts.
  64   void
  65   print_symbol_counts(const Symbol_table*, FILE*) const;
  66
  67   // Print a cross reference table.
  68   void
  69   print_cref(const Symbol_table*, FILE*) const;
  70
  71  private:
  72   // A list of input objects.
  73   typedef std::vector<Object*> Objects;
  74
  75   // Information we record for an archive.
  76   struct Archive_info
  77   {
  78     // Archive name.
  79     std::string name;
  80     // List of objects included from the archive.
  81     Objects* objects;
  82     // Number of archive members.
  83     size_t member_count;
  84   };
  85
  86   // A mapping from the name of an archive to the list of objects in
  87   // that archive.
  88   typedef std::map<std::string, Archive_info> Archives;
  89
  90   // For --cref, we build a cross reference table which maps from
  91   // symbols to lists of objects.  The symbols are sorted
  92   // alphabetically.
  93
  94   class Cref_table_compare
  95   {
  96   public:
  97     bool
  98     operator()(const Symbol*, const Symbol*) const;
  99   };
 100
 101   typedef std::map<const Symbol*, Objects*, Cref_table_compare> Cref_table;
 102
 103   // Report symbol counts for a list of Objects.
 104   void
 105   print_objects_symbol_counts(const Symbol_table*, FILE*, const Objects*) const;
 106
 107   // Report symbol counts for an object.
 108   void
 109   print_object_symbol_counts(const Symbol_table*, FILE*, const Object*) const;
 110
 111   // Gather cross reference information.
 112   void
 113   gather_cref(const Objects*, Cref_table*) const;
 114
 115   // List of input objects.
 116   Objects objects_;
 117   // List of input archives.  This is a mapping from the archive file
 118   // name to the list of objects.
 119   Archives archives_;
 120   // The list to which we are currently adding objects.
 121   Objects* current_;
 122 };
 123
 124 // Add an object.
 125
 126 void
 127 Cref_inputs::add_object(Object* object)
 128 {
 129   this->current_->push_back(object);
 130 }
 131
 132 // Start adding an archive.
 133
 134 void
 135 Cref_inputs::add_archive_start(Archive* archive)
 136 {
 137   gold_assert(this->current_ == &this->objects_);
 138   if (this->archives_.find(archive->name()) == this->archives_.end())
 139     {
 140       Archive_info* pai = &this->archives_[archive->name()];
 141       pai->name = archive->filename();
 142       pai->objects = new Objects();
 143       pai->member_count = archive->count_members();
 144     }
 145   this->current_ = this->archives_[archive->name()].objects;
 146 }
 147
 148 // Stop adding an archive.
 149
 150 void
 151 Cref_inputs::add_archive_stop(Archive*)
 152 {
 153   gold_assert(this->current_ != &this->objects_);
 154   this->current_ = &this->objects_;
 155 }
 156
 157 // Report symbol counts for an object.
 158
 159 void
 160 Cref_inputs::print_object_symbol_counts(const Symbol_table* symtab,
 161                                         FILE* f,
 162                                         const Object* object) const
 163 {
 164   size_t defined, used;
 165   object->get_global_symbol_counts(symtab, &defined, &used);
 166   fprintf(f, "symbols %s %zu %zu\n", object->name().c_str(), defined, used);
 167 }
 168
 169 // Report symbol counts for a list of inputs.
 170
 171 void
 172 Cref_inputs::print_objects_symbol_counts(const Symbol_table* symtab,
 173                                          FILE* f,
 174                                          const Objects* objects) const
 175 {
 176   for (Objects::const_iterator p = objects->begin();
 177        p != objects->end();
 178        ++p)
 179     this->print_object_symbol_counts(symtab, f, *p);
 180 }
 181
 182 // Print symbol counts.  This implements --print-symbol-counts.  This
 183 // is intended to be easily read by a program.  This outputs a series
 184 // of lines.  There are two different types of lines.
 185
 186 // The first is "symbols FILENAME DEFINED USED".  FILENAME is the name
 187 // of an object file included in the link; for an archive, this will
 188 // be ARCHIVEFILENAME(MEMBERNAME).  DEFINED is the number of symbols
 189 // which the object file defines.  USED is the number of symbols which
 190 // are used in the final output; this is the number of symbols which
 191 // appear in the final output table as having been defined by this
 192 // object.  These numbers will be different when weak symbols are
 193 // used, and they will be different for dynamic objects.
 194
 195 // The second is "archives FILENAME MEMBERS USED".  FILENAME is the
 196 // name of an archive file included in the link.  MEMBERS is the
 197 // number of members of the archive.  USED is the number of archive
 198 // members included in the link.
 199
 200 void
 201 Cref_inputs::print_symbol_counts(const Symbol_table* symtab, FILE* f) const
 202 {
 203   this->print_objects_symbol_counts(symtab, f, &this->objects_);
 204   for (Archives::const_iterator p = this->archives_.begin();
 205        p != this->archives_.end();
 206        ++p)
 207     {
 208       fprintf(f, "archive %s %zu %zu\n", p->second.name.c_str(),
 209              p->second.member_count, p->second.objects->size());
 210       this->print_objects_symbol_counts(symtab, f, p->second.objects);
 211     }
 212 }
 213
 214 // Sort symbols for the cross reference table.
 215
 216 bool
 217 Cref_inputs::Cref_table_compare::operator()(const Symbol* s1,
 218                                             const Symbol* s2) const
 219 {
 220   int i = strcmp(s1->name(), s2->name());
 221   if (i != 0)
 222     return i < 0;
 223
 224   if (s1->version() == NULL)
 225     {
 226       if (s2->version() != NULL)
 227         return true;
 228     }
 229   else if (s2->version() == NULL)
 230     return false;
 231   else
 232     {
 233       i = strcmp(s1->version(), s2->version());
 234       if (i != 0)
 235         return i < 0;
 236     }
 237
 238   // We should never have two different symbols with the same name and
 239   // version, where one doesn't forward to the other.
 240   if (s1 == s2)
 241     return false;
 242   if (s1->is_forwarder() && !s2->is_forwarder())
 243     return true;
 244   if (!s1->is_forwarder() && s2->is_forwarder())
 245     return false;
 246   gold_unreachable();
 247 }
 248
 249 // Gather cross reference information from a list of inputs.
 250
 251 void
 252 Cref_inputs::gather_cref(const Objects* objects, Cref_table* table) const
 253 {
 254   for (Objects::const_iterator po = objects->begin();
 255        po != objects->end();
 256        ++po)
 257     {
 258       const Object::Symbols* symbols = (*po)->get_global_symbols();
 259       if (symbols == NULL)
 260         continue;
 261       for (Object::Symbols::const_iterator ps = symbols->begin();
 262            ps != symbols->end();
 263            ++ps)
 264         {
 265           const Symbol* sym = *ps;
 266           if (sym == NULL)
 267             continue;
 268           Objects* const onull = NULL;
 269           std::pair<Cref_table::iterator, bool> ins =
 270             table->insert(std::make_pair(sym, onull));
 271           Cref_table::iterator pc = ins.first;
 272           if (ins.second)
 273             pc->second = new Objects();
 274           if (sym->source() == Symbol::FROM_OBJECT
 275               && sym->object() == *po
 276               && sym->is_defined())
 277             pc->second->insert(pc->second->begin(), *po);
 278           else
 279             pc->second->push_back(*po);
 280         }
 281     }
 282 }
 283
 284 // The column where the file name starts in a cross reference table.
 285
 286 static const size_t filecol = 50;
 287
 288 // Print a cross reference table.
 289
 290 void
 291 Cref_inputs::print_cref(const Symbol_table*, FILE* f) const
 292 {
 293   Cref_table table;
 294   this->gather_cref(&this->objects_, &table);
 295   for (Archives::const_iterator p = this->archives_.begin();
 296        p != this->archives_.end();
 297        ++p)
 298     this->gather_cref(p->second.objects, &table);
 299
 300   for (Cref_table::const_iterator pc = table.begin();
 301        pc != table.end();
 302        ++pc)
 303     {
 304       // If all the objects are dynamic, skip this symbol.
 305       const Symbol* sym = pc->first;
 306       const Objects* objects = pc->second;
 307       Objects::const_iterator po;
 308       for (po = objects->begin(); po != objects->end(); ++po)
 309         if (!(*po)->is_dynamic())
 310           break;
 311       if (po == objects->end())
 312         continue;
 313
 314       std::string s = sym->demangled_name();
 315       if (sym->version() != NULL)
 316         {
 317           s += '@';
 318           if (sym->is_default())
 319             s += '@';
 320           s += sym->version();
 321         }
 322
 323       fputs(s.c_str(), f);
 324
 325       size_t len = s.length();
 326
 327       for (po = objects->begin(); po != objects->end(); ++po)
 328         {
 329           int n = len < filecol ? filecol - len : 1;
 330           fprintf(f, "%*c%s\n", n, ' ', (*po)->name().c_str());
 331           len = 0;
 332         }
 333     }
 334 }
 335
 336 // Class Cref.
 337
 338 // Make sure the Cref_inputs object has been created.
 339
 340 void
 341 Cref::need_inputs()
 342 {
 343   if (this->inputs_ == NULL)
 344     this->inputs_ = new Cref_inputs();
 345 }
 346
 347 // Add an input object file.
 348
 349 void
 350 Cref::add_object(Object* object)
 351 {
 352   this->need_inputs();
 353   this->inputs_->add_object(object);
 354 }
 355
 356 // Start adding an archive.
 357
 358 void
 359 Cref::add_archive_start(Archive* archive)
 360 {
 361   this->need_inputs();
 362   this->inputs_->add_archive_start(archive);
 363 }
 364
 365 // Stop adding an archive.
 366
 367 void
 368 Cref::add_archive_stop(Archive* archive)
 369 {
 370   this->inputs_->add_archive_stop(archive);
 371 }
 372
 373 // Print symbol counts.
 374
 375 void
 376 Cref::print_symbol_counts(const Symbol_table* symtab) const
 377 {
 378   if (parameters->options().user_set_print_symbol_counts()
 379       && this->inputs_ != NULL)
 380     {
 381       FILE* f;
 382       if (strcmp(parameters->options().print_symbol_counts(), "-") == 0)
 383         f = stdout;
 384       else
 385         {
 386           f = fopen(parameters->options().print_symbol_counts(), "w");
 387           if (f == NULL)
 388             gold_error(_("cannot open symbol count file %s: %s"),
 389                        parameters->options().print_symbol_counts(),
 390                        strerror(errno));
 391         }
 392       if (f != NULL)
 393         this->inputs_->print_symbol_counts(symtab, f);
 394     }
 395 }
 396
 397 // Print a cross reference table.
 398
 399 void
 400 Cref::print_cref(const Symbol_table* symtab, FILE* f) const
 401 {
 402   fprintf(f, _("\nCross Reference Table\n\n"));
 403   const char* msg = _("Symbol");
 404   int len = filecol - strlen(msg);
 405   fprintf(f, "%s%*c%s\n", msg, len, ' ', _("File"));
 406
 407   if (parameters->options().cref() && this->inputs_ != NULL)
 408     this->inputs_->print_cref(symtab, f);
 409 }
 410
 411 } // End namespace gold.