gold/parameters.cc

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