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), 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_options(const General_options* options)
  83 {
  84   gold_assert(!this->options_valid());
  85   this->options_ = options;
  86   // For speed, we convert the options() debug var from a string to an
  87   // enum (from debug.h).
  88   this->debug_ = debug_string_to_enum(this->options().debug());
  89   // Set incremental_mode_ based on the value of the --incremental option.
  90   // We copy the mode into parameters because it can change based on inputs.
  91   this->incremental_mode_ = this->options().incremental_mode();
  92   // If --verbose is set, it acts as "--debug=files".
  93   if (options->verbose())
  94     this->debug_ |= DEBUG_FILES;
  95   if (this->target_valid())
  96     this->check_target_endianness();
  97 }
  98
  99 void
 100 Parameters::set_doing_static_link(bool doing_static_link)
 101 {
 102   gold_assert(!this->doing_static_link_valid_);
 103   this->doing_static_link_ = doing_static_link;
 104   this->doing_static_link_valid_ = true;
 105 }
 106
 107 void
 108 Parameters::set_target(Target* target)
 109 {
 110   this->set_parameters_target_once_->run_once(static_cast<void*>(target));
 111   gold_assert(target == this->target_);
 112 }
 113
 114 // This is called at most once.
 115
 116 void
 117 Parameters::set_target_once(Target* target)
 118 {
 119   gold_assert(this->target_ == NULL);
 120   this->target_ = target;
 121   if (this->options_valid())
 122     this->check_target_endianness();
 123 }
 124
 125 // Clear the target, for testing.
 126
 127 void
 128 Parameters::clear_target()
 129 {
 130   this->target_ = NULL;
 131   // We need a new Set_parameters_target_once so that we can set the
 132   // target again.
 133   this->set_parameters_target_once_ = new Set_parameters_target_once(this);
 134 }
 135
 136 // Return whether TARGET is compatible with the target we are using.
 137
 138 bool
 139 Parameters::is_compatible_target(const Target* target) const
 140 {
 141   if (this->target_ == NULL)
 142     return true;
 143   return target == this->target_;
 144 }
 145
 146 Parameters::Target_size_endianness
 147 Parameters::size_and_endianness() const
 148 {
 149   if (this->target().get_size() == 32)
 150     {
 151       if (!this->target().is_big_endian())
 152         {
 153 #ifdef HAVE_TARGET_32_LITTLE
 154           return TARGET_32_LITTLE;
 155 #else
 156           gold_unreachable();
 157 #endif
 158         }
 159       else
 160         {
 161 #ifdef HAVE_TARGET_32_BIG
 162           return TARGET_32_BIG;
 163 #else
 164           gold_unreachable();
 165 #endif
 166         }
 167     }
 168   else if (parameters->target().get_size() == 64)
 169     {
 170       if (!parameters->target().is_big_endian())
 171         {
 172 #ifdef HAVE_TARGET_64_LITTLE
 173           return TARGET_64_LITTLE;
 174 #else
 175           gold_unreachable();
 176 #endif
 177         }
 178       else
 179         {
 180 #ifdef HAVE_TARGET_64_BIG
 181           return TARGET_64_BIG;
 182 #else
 183           gold_unreachable();
 184 #endif
 185         }
 186     }
 187   else
 188     gold_unreachable();
 189 }
 190
 191 // If output endianness is specified in command line, check that it does
 192 // not conflict with the target.
 193
 194 void
 195 Parameters::check_target_endianness()
 196 {
 197   General_options::Endianness endianness = this->options().endianness();
 198   if (endianness != General_options::ENDIANNESS_NOT_SET)
 199     {
 200       bool big_endian;
 201       if (endianness == General_options::ENDIANNESS_BIG)
 202         big_endian = true;
 203       else
 204         {
 205           gold_assert(endianness == General_options::ENDIANNESS_LITTLE);
 206           big_endian = false;;
 207         }
 208
 209       if (this->target().is_big_endian() != big_endian)
 210         gold_error(_("input file does not match -EB/EL option"));
 211     }
 212 }
 213
 214 // Return the name of the entry symbol.
 215
 216 const char*
 217 Parameters::entry() const
 218 {
 219   const char* ret = this->options().entry();
 220   if (ret == NULL)
 221     {
 222       // FIXME: Need to support target specific entry symbol.
 223       ret = "_start";
 224     }
 225   return ret;
 226 }
 227
 228 // Set the incremental linking mode to INCREMENTAL_FULL.  Used when
 229 // the linker determines that an incremental update is not possible.
 230 // Returns false if the incremental mode was INCREMENTAL_UPDATE,
 231 // indicating that the linker should exit if an update is not possible.
 232
 233 bool
 234 Parameters::set_incremental_full()
 235 {
 236   gold_assert(this->incremental_mode_ != General_options::INCREMENTAL_OFF);
 237   if (this->incremental_mode_ == General_options::INCREMENTAL_UPDATE)
 238     return false;
 239   this->incremental_mode_ = General_options::INCREMENTAL_FULL;
 240   return true;
 241 }
 242
 243 // Return true if we need to prepare incremental linking information.
 244
 245 bool
 246 Parameters::incremental() const
 247 {
 248   return this->incremental_mode_ != General_options::INCREMENTAL_OFF;
 249 }
 250
 251 // Return true if we are doing a full incremental link.
 252
 253 bool
 254 Parameters::incremental_full() const
 255 {
 256   return this->incremental_mode_ == General_options::INCREMENTAL_FULL;
 257 }
 258
 259 // Return true if we are doing an incremental update.
 260
 261 bool
 262 Parameters::incremental_update() const
 263 {
 264   return (this->incremental_mode_ == General_options::INCREMENTAL_UPDATE
 265           || this->incremental_mode_ == General_options::INCREMENTAL_AUTO);
 266 }
 267
 268 void
 269 set_parameters_errors(Errors* errors)
 270 { static_parameters.set_errors(errors); }
 271
 272 void
 273 set_parameters_options(const General_options* options)
 274 { static_parameters.set_options(options); }
 275
 276 void
 277 set_parameters_target(Target* target)
 278 {
 279   static_parameters.set_target(target);
 280   target->select_as_default_target();
 281 }
 282
 283 void
 284 set_parameters_doing_static_link(bool doing_static_link)
 285 { static_parameters.set_doing_static_link(doing_static_link); }
 286
 287 // Set the incremental linking mode to INCREMENTAL_FULL.  Used when
 288 // the linker determines that an incremental update is not possible.
 289 // Returns false if the incremental mode was INCREMENTAL_UPDATE,
 290 // indicating that the linker should exit if an update is not possible.
 291 bool
 292 set_parameters_incremental_full()
 293 { return static_parameters.set_incremental_full(); }
 294
 295 // Force the target to be valid by using the default.  Use the
 296 // --oformat option is set; this supports the x86_64 kernel build,
 297 // which converts a binary file to an object file using -r --format
 298 // binary --oformat elf32-i386 foo.o.  Otherwise use the configured
 299 // default.
 300
 301 void
 302 parameters_force_valid_target()
 303 {
 304   if (parameters->target_valid())
 305     return;
 306
 307   gold_assert(parameters->options_valid());
 308   if (parameters->options().user_set_oformat())
 309     {
 310       const char* bfd_name = parameters->options().oformat();
 311       Target* target = select_target_by_bfd_name(bfd_name);
 312       if (target != NULL)
 313         {
 314           set_parameters_target(target);
 315           return;
 316         }
 317
 318       gold_error(_("unrecognized output format %s"), bfd_name);
 319     }
 320
 321   if (parameters->options().user_set_m())
 322     {
 323       const char* emulation = parameters->options().m();
 324       Target* target = select_target_by_emulation(emulation);
 325       if (target != NULL)
 326         {
 327           set_parameters_target(target);
 328           return;
 329         }
 330
 331       gold_error(_("unrecognized emulation %s"), emulation);
 332     }
 333
 334   // The GOLD_DEFAULT_xx macros are defined by the configure script.
 335   bool is_big_endian;
 336   General_options::Endianness endianness = parameters->options().endianness();
 337   if (endianness == General_options::ENDIANNESS_BIG)
 338     is_big_endian = true;
 339   else if (endianness == General_options::ENDIANNESS_LITTLE)
 340     is_big_endian = false;
 341   else
 342     is_big_endian = GOLD_DEFAULT_BIG_ENDIAN;
 343
 344   Target* target = select_target(elfcpp::GOLD_DEFAULT_MACHINE,
 345                                  GOLD_DEFAULT_SIZE,
 346                                  is_big_endian,
 347                                  elfcpp::GOLD_DEFAULT_OSABI,
 348                                  0);
 349   gold_assert(target != NULL);
 350   set_parameters_target(target);
 351 }
 352
 353 // Clear the current target, for testing.
 354
 355 void
 356 parameters_clear_target()
 357 {
 358   static_parameters.clear_target();
 359 }
 360
 361 } // End namespace gold.