gold/parameters.h

   1 // parameters.h -- general parameters for a link using gold  -*- C++ -*-
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 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 #ifndef GOLD_PARAMETERS_H
  24 #define GOLD_PARAMETERS_H
  25
  26 namespace gold
  27 {
  28
  29 class General_options;
  30 class Errors;
  31 class Target;
  32 template<int size, bool big_endian>
  33 class Sized_target;
  34 class Set_parameters_target_once;
  35
  36 // Here we define the Parameters class which simply holds simple
  37 // general parameters which apply to the entire link.  We use a global
  38 // variable for this.  The parameters class holds three types of data:
  39 //    1) An Errors struct.  Any part of the code that wants to log an
  40 //       error can use parameters->errors().
  41 //    2) A const General_options.  These are the options as read on
  42 //       the commandline.
  43 //    3) Target information, such as size and endian-ness.  This is
  44 //       available as soon as we've decided on the Target (after
  45 //       parsing the first .o file).
  46 //    4) Whether we're doing a static link or not.  This is set
  47 //       after all inputs have been read and we know if any is a
  48 //       dynamic library.
  49
  50 class Parameters
  51 {
  52  public:
  53   Parameters();
  54
  55   // These should be called as soon as they are known.
  56   void
  57   set_errors(Errors* errors);
  58
  59   void
  60   set_options(const General_options* options);
  61
  62   void
  63   set_target(Target* target);
  64
  65   void
  66   set_doing_static_link(bool doing_static_link);
  67
  68   // Return the error object.
  69   Errors*
  70   errors() const
  71   { return this->errors_; }
  72
  73   // Whether the options are valid.  This should not normally be
  74   // called, but it is needed by gold_exit.
  75   bool
  76   options_valid() const
  77   { return this->options_ != NULL; }
  78
  79   // Return the options object.
  80   const General_options&
  81   options() const
  82   {
  83     gold_assert(this->options_valid());
  84     return *this->options_;
  85   }
  86
  87   // Return whether the target field has been set.
  88   bool
  89   target_valid() const
  90   { return this->target_ != NULL; }
  91
  92   // The target of the output file we are generating.
  93   const Target&
  94   target() const
  95   {
  96     gold_assert(this->target_valid());
  97     return *this->target_;
  98   }
  99
 100   // The Sized_target of the output file.  The caller must request the
 101   // right size and endianness.
 102   template<int size, bool big_endian>
 103   Sized_target<size, big_endian>*
 104   sized_target() const
 105   {
 106     gold_assert(this->target_valid());
 107     return static_cast<Sized_target<size, big_endian>*>(this->target_);
 108   }
 109
 110   // Clear the target, for testing.
 111   void
 112   clear_target();
 113
 114   // Return true if TARGET is compatible with the current target.
 115   bool
 116   is_compatible_target(const Target*) const;
 117
 118   bool
 119   doing_static_link() const
 120   {
 121     gold_assert(this->doing_static_link_valid_);
 122     return this->doing_static_link_;
 123   }
 124
 125   // This is just a copy of options().debug().  We make a copy so we
 126   // don't have to #include options.h in order to inline
 127   // is_debugging_enabled, below.
 128   int
 129   debug() const
 130   {
 131     // This can be called before the options are set up.
 132     if (!this->options_valid())
 133       return 0;
 134     return debug_;
 135   }
 136
 137   // Return the name of the entry symbol.
 138   const char*
 139   entry() const;
 140
 141   // A convenience routine for combining size and endianness.  It also
 142   // checks the HAVE_TARGET_FOO configure options and dies if the
 143   // current target's size/endianness is not supported according to
 144   // HAVE_TARGET_FOO.  Otherwise it returns this enum
 145   enum Target_size_endianness
 146   { TARGET_32_LITTLE, TARGET_32_BIG, TARGET_64_LITTLE, TARGET_64_BIG };
 147
 148   Target_size_endianness
 149   size_and_endianness() const;
 150
 151   // Set the incremental linking mode to INCREMENTAL_FULL.  Used when
 152   // the linker determines that an incremental update is not possible.
 153   // Returns false if the incremental mode was INCREMENTAL_UPDATE,
 154   // indicating that the linker should exit if an update is not possible.
 155   bool
 156   set_incremental_full();
 157
 158   // Return true if we need to prepare incremental linking information.
 159   bool
 160   incremental() const;
 161
 162   // Return true if we are doing an incremental update.
 163   bool
 164   incremental_update() const;
 165
 166  private:
 167   void
 168   set_target_once(Target*);
 169
 170   void
 171   check_target_endianness();
 172
 173   friend class Set_parameters_target_once;
 174
 175   Errors* errors_;
 176   const General_options* options_;
 177   Target* target_;
 178   bool doing_static_link_valid_;
 179   bool doing_static_link_;
 180   int debug_;
 181   int incremental_mode_;
 182   Set_parameters_target_once* set_parameters_target_once_;
 183 };
 184
 185 // This is a global variable.
 186 extern const Parameters* parameters;
 187
 188 // We use free functions for these since they affect a global variable
 189 // that is internal to parameters.cc.
 190
 191 extern void
 192 set_parameters_errors(Errors* errors);
 193
 194 extern void
 195 set_parameters_options(const General_options* options);
 196
 197 extern void
 198 set_parameters_target(Target* target);
 199
 200 extern void
 201 set_parameters_doing_static_link(bool doing_static_link);
 202
 203 extern bool
 204 set_parameters_incremental_full();
 205
 206 // Ensure that the target to be valid by using the default target if
 207 // necessary.
 208
 209 extern void
 210 parameters_force_valid_target();
 211
 212 // Clear the current target, for testing.
 213
 214 extern void
 215 parameters_clear_target();
 216
 217 // Return whether we are doing a particular debugging type.  The
 218 // argument is one of the flags from debug.h.
 219
 220 inline bool
 221 is_debugging_enabled(unsigned int type)
 222 { return (parameters->debug() & type) != 0; }
 223
 224 } // End namespace gold.
 225
 226 #endif // !defined(GOLD_PARAMETERS_H)