gold/parameters.cc

   1 // parameters.cc -- general parameters for a link using gold
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
   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     this->check_target_endianness();
 131 }
 132
 133 // Clear the target, for testing.
 134
 135 void
 136 Parameters::clear_target()
 137 {
 138   this->target_ = NULL;
 139   // We need a new Set_parameters_target_once so that we can set the
 140   // target again.
 141   this->set_parameters_target_once_ = new Set_parameters_target_once(this);
 142 }
 143
 144 // Return whether TARGET is compatible with the target we are using.
 145
 146 bool
 147 Parameters::is_compatible_target(const Target* target) const
 148 {
 149   if (this->target_ == NULL)
 150     return true;
 151   return target == this->target_;
 152 }
 153
 154 Parameters::Target_size_endianness
 155 Parameters::size_and_endianness() const
 156 {
 157   if (this->target().get_size() == 32)
 158     {
 159       if (!this->target().is_big_endian())
 160         {
 161 #ifdef HAVE_TARGET_32_LITTLE
 162           return TARGET_32_LITTLE;
 163 #else
 164           gold_unreachable();
 165 #endif
 166         }
 167       else
 168         {
 169 #ifdef HAVE_TARGET_32_BIG
 170           return TARGET_32_BIG;
 171 #else
 172           gold_unreachable();
 173 #endif
 174         }
 175     }
 176   else if (parameters->target().get_size() == 64)
 177     {
 178       if (!parameters->target().is_big_endian())
 179         {
 180 #ifdef HAVE_TARGET_64_LITTLE
 181           return TARGET_64_LITTLE;
 182 #else
 183           gold_unreachable();
 184 #endif
 185         }
 186       else
 187         {
 188 #ifdef HAVE_TARGET_64_BIG
 189           return TARGET_64_BIG;
 190 #else
 191           gold_unreachable();
 192 #endif
 193         }
 194     }
 195   else
 196     gold_unreachable();
 197 }
 198
 199 // If output endianness is specified in command line, check that it does
 200 // not conflict with the target.
 201
 202 void
 203 Parameters::check_target_endianness()
 204 {
 205   General_options::Endianness endianness = this->options().endianness();
 206   if (endianness != General_options::ENDIANNESS_NOT_SET)
 207     {
 208       bool big_endian;
 209       if (endianness == General_options::ENDIANNESS_BIG)
 210         big_endian = true;
 211       else
 212         {
 213           gold_assert(endianness == General_options::ENDIANNESS_LITTLE);
 214           big_endian = false;;
 215         }
 216
 217       if (this->target().is_big_endian() != big_endian)
 218         gold_error(_("input file does not match -EB/EL option"));
 219     }
 220 }
 221
 222 // Return the name of the entry symbol.
 223
 224 const char*
 225 Parameters::entry() const
 226 {
 227   const char* ret = this->options().entry();
 228   if (ret == NULL)
 229     {
 230       // FIXME: Need to support target specific entry symbol.
 231       ret = "_start";
 232     }
 233   return ret;
 234 }
 235
 236 // Set the incremental linking mode to INCREMENTAL_FULL.  Used when
 237 // the linker determines that an incremental update is not possible.
 238 // Returns false if the incremental mode was INCREMENTAL_UPDATE,
 239 // indicating that the linker should exit if an update is not possible.
 240
 241 bool
 242 Parameters::set_incremental_full()
 243 {
 244   gold_assert(this->incremental_mode_ != General_options::INCREMENTAL_OFF);
 245   if (this->incremental_mode_ == General_options::INCREMENTAL_UPDATE)
 246     return false;
 247   this->incremental_mode_ = General_options::INCREMENTAL_FULL;
 248   return true;
 249 }
 250
 251 // Return true if we need to prepare incremental linking information.
 252
 253 bool
 254 Parameters::incremental() const
 255 {
 256   return this->incremental_mode_ != General_options::INCREMENTAL_OFF;
 257 }
 258
 259 // Return true if we are doing a full incremental link.
 260
 261 bool
 262 Parameters::incremental_full() const
 263 {
 264   return this->incremental_mode_ == General_options::INCREMENTAL_FULL;
 265 }
 266
 267 // Return true if we are doing an incremental update.
 268
 269 bool
 270 Parameters::incremental_update() const
 271 {
 272   return (this->incremental_mode_ == General_options::INCREMENTAL_UPDATE
 273           || this->incremental_mode_ == General_options::INCREMENTAL_AUTO);
 274 }
 275
 276 void
 277 set_parameters_errors(Errors* errors)
 278 { static_parameters.set_errors(errors); }
 279
 280 void
 281 set_parameters_timer(Timer* timer)
 282 { static_parameters.set_timer(timer); }
 283
 284 void
 285 set_parameters_options(const General_options* options)
 286 { static_parameters.set_options(options); }
 287
 288 void
 289 set_parameters_target(Target* target)
 290 {
 291   static_parameters.set_target(target);
 292   target->select_as_default_target();
 293 }
 294
 295 void
 296 set_parameters_doing_static_link(bool doing_static_link)
 297 { static_parameters.set_doing_static_link(doing_static_link); }
 298
 299 // Set the incremental linking mode to INCREMENTAL_FULL.  Used when
 300 // the linker determines that an incremental update is not possible.
 301 // Returns false if the incremental mode was INCREMENTAL_UPDATE,
 302 // indicating that the linker should exit if an update is not possible.
 303 bool
 304 set_parameters_incremental_full()
 305 { return static_parameters.set_incremental_full(); }
 306
 307 // Force the target to be valid by using the default.  Use the
 308 // --oformat option is set; this supports the x86_64 kernel build,
 309 // which converts a binary file to an object file using -r --format
 310 // binary --oformat elf32-i386 foo.o.  Otherwise use the configured
 311 // default.
 312
 313 void
 314 parameters_force_valid_target()
 315 {
 316   if (parameters->target_valid())
 317     return;
 318
 319   gold_assert(parameters->options_valid());
 320   if (parameters->options().user_set_oformat())
 321     {
 322       const char* bfd_name = parameters->options().oformat();
 323       Target* target = select_target_by_bfd_name(bfd_name);
 324       if (target != NULL)
 325         {
 326           set_parameters_target(target);
 327           return;
 328         }
 329
 330       gold_error(_("unrecognized output format %s"), bfd_name);
 331     }
 332
 333   if (parameters->options().user_set_m())
 334     {
 335       const char* emulation = parameters->options().m();
 336       Target* target = select_target_by_emulation(emulation);
 337       if (target != NULL)
 338         {
 339           set_parameters_target(target);
 340           return;
 341         }
 342
 343       gold_error(_("unrecognized emulation %s"), emulation);
 344     }
 345
 346   // The GOLD_DEFAULT_xx macros are defined by the configure script.
 347   bool is_big_endian;
 348   General_options::Endianness endianness = parameters->options().endianness();
 349   if (endianness == General_options::ENDIANNESS_BIG)
 350     is_big_endian = true;
 351   else if (endianness == General_options::ENDIANNESS_LITTLE)
 352     is_big_endian = false;
 353   else
 354     is_big_endian = GOLD_DEFAULT_BIG_ENDIAN;
 355
 356   Target* target = select_target(NULL, 0,
 357                                  elfcpp::GOLD_DEFAULT_MACHINE,
 358                                  GOLD_DEFAULT_SIZE,
 359                                  is_big_endian,
 360                                  elfcpp::GOLD_DEFAULT_OSABI,
 361                                  0);
 362
 363   if (target == NULL)
 364     {
 365       gold_assert(is_big_endian != GOLD_DEFAULT_BIG_ENDIAN);
 366       gold_fatal(_("no supported target for -EB/-EL option"));
 367     }
 368
 369   set_parameters_target(target);
 370 }
 371
 372 // Clear the current target, for testing.
 373
 374 void
 375 parameters_clear_target()
 376 {
 377   static_parameters.clear_target();
 378 }
 379
 380 } // End namespace gold.