gold/parameters.cc

   1 // parameters.cc -- general parameters for a link using gold
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
   4 // Free Software Foundation, Inc.
   5 // Written by Ian Lance Taylor <iant@google.com>.
   6
   7 // This file is part of gold.
   8
   9 // This program is free software; you can redistribute it and/or modify
  10 // it under the terms of the GNU General Public License as published by
  11 // the Free Software Foundation; either version 3 of the License, or
  12 // (at your option) any later version.
  13
  14 // This program is distributed in the hope that it will be useful,
  15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 // GNU General Public License for more details.
  18
  19 // You should have received a copy of the GNU General Public License
  20 // along with this program; if not, write to the Free Software
  21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  22 // MA 02110-1301, USA.
  23
  24 #include "gold.h"
  25
  26 #include "debug.h"
  27 #include "options.h"
  28 #include "target.h"
  29 #include "target-select.h"
  30
  31 namespace gold
  32 {
  33
  34 // Our local version of the variable, which is not const.
  35
  36 static Parameters static_parameters;
  37
  38 // The global variable.
  39
  40 const Parameters* parameters = &static_parameters;
  41
  42 // A helper class to set the target once.
  43
  44 class Set_parameters_target_once : public Once
  45 {
  46  public:
  47   Set_parameters_target_once(Parameters* parameters)
  48     : parameters_(parameters)
  49   { }
  50
  51  protected:
  52   void
  53   do_run_once(void* arg)
  54   { this->parameters_->set_target_once(static_cast<Target*>(arg)); }
  55
  56  private:
  57   Parameters* parameters_;
  58 };
  59
  60 // We only need one Set_parameters_target_once.
  61
  62 static
  63 Set_parameters_target_once set_parameters_target_once(&static_parameters);
  64
  65 // Class Parameters.
  66
  67 Parameters::Parameters()
  68    : errors_(NULL), timer_(NULL), options_(NULL), target_(NULL),
  69      doing_static_link_valid_(false), doing_static_link_(false),
  70      debug_(0), incremental_mode_(General_options::INCREMENTAL_OFF),
  71      set_parameters_target_once_(&set_parameters_target_once)
  72  {
  73  }
  74
  75 void
  76 Parameters::set_errors(Errors* errors)
  77 {
  78   gold_assert(this->errors_ == NULL);
  79   this->errors_ = errors;
  80 }
  81
  82 void
  83 Parameters::set_timer(Timer* timer)
  84 {
  85   gold_assert(this->timer_ == NULL);
  86   this->timer_ = timer;
  87 }
  88
  89 void
  90 Parameters::set_options(const General_options* options)
  91 {
  92   gold_assert(!this->options_valid());
  93   this->options_ = options;
  94   // For speed, we convert the options() debug var from a string to an
  95   // enum (from debug.h).
  96   this->debug_ = debug_string_to_enum(this->options().debug());
  97   // Set incremental_mode_ based on the value of the --incremental option.
  98   // We copy the mode into parameters because it can change based on inputs.
  99   this->incremental_mode_ = this->options().incremental_mode();
 100   // If --verbose is set, it acts as "--debug=files".
 101   if (options->verbose())
 102     this->debug_ |= DEBUG_FILES;
 103   if (this->target_valid())
 104     this->check_target_endianness();
 105 }
 106
 107 void
 108 Parameters::set_doing_static_link(bool doing_static_link)
 109 {
 110   gold_assert(!this->doing_static_link_valid_);
 111   this->doing_static_link_ = doing_static_link;
 112   this->doing_static_link_valid_ = true;
 113 }
 114
 115 void
 116 Parameters::set_target(Target* target)
 117 {
 118   this->set_parameters_target_once_->run_once(static_cast<void*>(target));
 119   gold_assert(target == this->target_);
 120 }
 121
 122 // This is called at most once.
 123
 124 void
 125 Parameters::set_target_once(Target* target)
 126 {
 127   gold_assert(this->target_ == NULL);
 128   this->target_ = target;
 129   if (this->options_valid())
 130     {
 131       this->check_target_endianness();
 132       this->check_rodata_segment();
 133     }
 134 }
 135
 136 // Clear the target, for testing.
 137
 138 void
 139 Parameters::clear_target()
 140 {
 141   this->target_ = NULL;
 142   // We need a new Set_parameters_target_once so that we can set the
 143   // target again.
 144   this->set_parameters_target_once_ = new Set_parameters_target_once(this);
 145 }
 146
 147 // Return whether TARGET is compatible with the target we are using.
 148
 149 bool
 150 Parameters::is_compatible_target(const Target* target) const
 151 {
 152   if (this->target_ == NULL)
 153     return true;
 154   return target == this->target_;
 155 }
 156
 157 Parameters::Target_size_endianness
 158 Parameters::size_and_endianness() const
 159 {
 160   if (this->target().get_size() == 32)
 161     {
 162       if (!this->target().is_big_endian())
 163         {
 164 #ifdef HAVE_TARGET_32_LITTLE
 165           return TARGET_32_LITTLE;
 166 #else
 167           gold_unreachable();
 168 #endif
 169         }
 170       else
 171         {
 172 #ifdef HAVE_TARGET_32_BIG
 173           return TARGET_32_BIG;
 174 #else
 175           gold_unreachable();
 176 #endif
 177         }
 178     }
 179   else if (parameters->target().get_size() == 64)
 180     {
 181       if (!parameters->target().is_big_endian())
 182         {
 183 #ifdef HAVE_TARGET_64_LITTLE
 184           return TARGET_64_LITTLE;
 185 #else
 186           gold_unreachable();
 187 #endif
 188         }
 189       else
 190         {
 191 #ifdef HAVE_TARGET_64_BIG
 192           return TARGET_64_BIG;
 193 #else
 194           gold_unreachable();
 195 #endif
 196         }
 197     }
 198   else
 199     gold_unreachable();
 200 }
 201
 202 // If output endianness is specified in command line, check that it does
 203 // not conflict with the target.
 204
 205 void
 206 Parameters::check_target_endianness()
 207 {
 208   General_options::Endianness endianness = this->options().endianness();
 209   if (endianness != General_options::ENDIANNESS_NOT_SET)
 210     {
 211       bool big_endian;
 212       if (endianness == General_options::ENDIANNESS_BIG)
 213         big_endian = true;
 214       else
 215         {
 216           gold_assert(endianness == General_options::ENDIANNESS_LITTLE);
 217           big_endian = false;;
 218         }
 219
 220       if (this->target().is_big_endian() != big_endian)
 221         gold_error(_("input file does not match -EB/EL option"));
 222     }
 223 }
 224
 225 void
 226 Parameters::check_rodata_segment()
 227 {
 228   if (this->options().user_set_Trodata_segment()
 229       && !this->options().rosegment()
 230       && !this->target().isolate_execinstr())
 231     gold_error(_("-Trodata-segment is meaningless without --rosegment"));
 232 }
 233
 234 // Return the name of the entry symbol.
 235
 236 const char*
 237 Parameters::entry() const
 238 {
 239   const char* ret = this->options().entry();
 240   if (ret == NULL)
 241     ret = parameters->target().entry_symbol_name();
 242   return ret;
 243 }
 244
 245 // Set the incremental linking mode to INCREMENTAL_FULL.  Used when
 246 // the linker determines that an incremental update is not possible.
 247 // Returns false if the incremental mode was INCREMENTAL_UPDATE,
 248 // indicating that the linker should exit if an update is not possible.
 249
 250 bool
 251 Parameters::set_incremental_full()
 252 {
 253   gold_assert(this->incremental_mode_ != General_options::INCREMENTAL_OFF);
 254   if (this->incremental_mode_ == General_options::INCREMENTAL_UPDATE)
 255     return false;
 256   this->incremental_mode_ = General_options::INCREMENTAL_FULL;
 257   return true;
 258 }
 259
 260 // Return true if we need to prepare incremental linking information.
 261
 262 bool
 263 Parameters::incremental() const
 264 {
 265   return this->incremental_mode_ != General_options::INCREMENTAL_OFF;
 266 }
 267
 268 // Return true if we are doing a full incremental link.
 269
 270 bool
 271 Parameters::incremental_full() const
 272 {
 273   return this->incremental_mode_ == General_options::INCREMENTAL_FULL;
 274 }
 275
 276 // Return true if we are doing an incremental update.
 277
 278 bool
 279 Parameters::incremental_update() const
 280 {
 281   return (this->incremental_mode_ == General_options::INCREMENTAL_UPDATE
 282           || this->incremental_mode_ == General_options::INCREMENTAL_AUTO);
 283 }
 284
 285 void
 286 set_parameters_errors(Errors* errors)
 287 { static_parameters.set_errors(errors); }
 288
 289 void
 290 set_parameters_timer(Timer* timer)
 291 { static_parameters.set_timer(timer); }
 292
 293 void
 294 set_parameters_options(const General_options* options)
 295 { static_parameters.set_options(options); }
 296
 297 void
 298 set_parameters_target(Target* target)
 299 {
 300   static_parameters.set_target(target);
 301   target->select_as_default_target();
 302 }
 303
 304 void
 305 set_parameters_doing_static_link(bool doing_static_link)
 306 { static_parameters.set_doing_static_link(doing_static_link); }
 307
 308 // Set the incremental linking mode to INCREMENTAL_FULL.  Used when
 309 // the linker determines that an incremental update is not possible.
 310 // Returns false if the incremental mode was INCREMENTAL_UPDATE,
 311 // indicating that the linker should exit if an update is not possible.
 312 bool
 313 set_parameters_incremental_full()
 314 { return static_parameters.set_incremental_full(); }
 315
 316 // Force the target to be valid by using the default.  Use the
 317 // --oformat option is set; this supports the x86_64 kernel build,
 318 // which converts a binary file to an object file using -r --format
 319 // binary --oformat elf32-i386 foo.o.  Otherwise use the configured
 320 // default.
 321
 322 void
 323 parameters_force_valid_target()
 324 {
 325   if (parameters->target_valid())
 326     return;
 327
 328   gold_assert(parameters->options_valid());
 329   if (parameters->options().user_set_oformat())
 330     {
 331       const char* bfd_name = parameters->options().oformat();
 332       Target* target = select_target_by_bfd_name(bfd_name);
 333       if (target != NULL)
 334         {
 335           set_parameters_target(target);
 336           return;
 337         }
 338
 339       gold_error(_("unrecognized output format %s"), bfd_name);
 340     }
 341
 342   if (parameters->options().user_set_m())
 343     {
 344       const char* emulation = parameters->options().m();
 345       Target* target = select_target_by_emulation(emulation);
 346       if (target != NULL)
 347         {
 348           set_parameters_target(target);
 349           return;
 350         }
 351
 352       gold_error(_("unrecognized emulation %s"), emulation);
 353     }
 354
 355   // The GOLD_DEFAULT_xx macros are defined by the configure script.
 356   bool is_big_endian;
 357   General_options::Endianness endianness = parameters->options().endianness();
 358   if (endianness == General_options::ENDIANNESS_BIG)
 359     is_big_endian = true;
 360   else if (endianness == General_options::ENDIANNESS_LITTLE)
 361     is_big_endian = false;
 362   else
 363     is_big_endian = GOLD_DEFAULT_BIG_ENDIAN;
 364
 365   Target* target = select_target(NULL, 0,
 366                                  elfcpp::GOLD_DEFAULT_MACHINE,
 367                                  GOLD_DEFAULT_SIZE,
 368                                  is_big_endian,
 369                                  elfcpp::GOLD_DEFAULT_OSABI,
 370                                  0);
 371
 372   if (target == NULL)
 373     {
 374       gold_assert(is_big_endian != GOLD_DEFAULT_BIG_ENDIAN);
 375       gold_fatal(_("no supported target for -EB/-EL option"));
 376     }
 377
 378   set_parameters_target(target);
 379 }
 380
 381 // Clear the current target, for testing.
 382
 383 void
 384 parameters_clear_target()
 385 {
 386   static_parameters.clear_target();
 387 }
 388
 389 } // End namespace gold.