gold/target-select.cc

   1 // target-select.cc -- select a target for an object file
   2
   3 // Copyright 2006, 2007, 2008 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 <cstring>
  26
  27 #include "elfcpp.h"
  28 #include "target-select.h"
  29
  30 namespace
  31 {
  32
  33 // The start of the list of target selectors.
  34
  35 gold::Target_selector* target_selectors;
  36
  37 } // End anonymous namespace.
  38
  39 namespace gold
  40 {
  41
  42 // Construct a Target_selector, which means adding it to the linked
  43 // list.  This runs at global constructor time, so we want it to be
  44 // fast.
  45
  46 Target_selector::Target_selector(int machine, int size, bool is_big_endian,
  47                                  const char* bfd_name)
  48   : machine_(machine), size_(size), is_big_endian_(is_big_endian),
  49     bfd_name_(bfd_name), instantiated_target_(NULL), lock_(NULL),
  50     initialize_lock_(&this->lock_)
  51
  52 {
  53   this->next_ = target_selectors;
  54   target_selectors = this;
  55 }
  56
  57 // Instantiate the target and return it.  Use a lock to avoid
  58 // instantiating two instances of the same target.
  59
  60 Target*
  61 Target_selector::instantiate_target()
  62 {
  63   this->initialize_lock_.initialize();
  64   Hold_optional_lock hl(this->lock_);
  65   if (this->instantiated_target_ == NULL)
  66     this->instantiated_target_ = this->do_instantiate_target();
  67   return this->instantiated_target_;
  68 }
  69
  70 // Find the target for an ELF file.
  71
  72 Target*
  73 select_target(int machine, int size, bool is_big_endian, int osabi,
  74               int abiversion)
  75 {
  76   for (Target_selector* p = target_selectors; p != NULL; p = p->next())
  77     {
  78       int pmach = p->machine();
  79       if ((pmach == machine || pmach == elfcpp::EM_NONE)
  80           && p->get_size() == size
  81           && (p->is_big_endian() ? is_big_endian : !is_big_endian))
  82         {
  83           Target* ret = p->recognize(machine, osabi, abiversion);
  84           if (ret != NULL)
  85             return ret;
  86         }
  87     }
  88   return NULL;
  89 }
  90
  91 // Find a target using a BFD name.  This is used to support the
  92 // --oformat option.
  93
  94 Target*
  95 select_target_by_name(const char* name)
  96 {
  97   for (Target_selector* p = target_selectors; p != NULL; p = p->next())
  98     {
  99       const char* pname = p->bfd_name();
 100       if (pname == NULL || strcmp(pname, name) == 0)
 101         {
 102           Target* ret = p->recognize_by_name(name);
 103           if (ret != NULL)
 104             return ret;
 105         }
 106     }
 107   return NULL;
 108 }
 109
 110 // Push all the supported BFD names onto a vector.
 111
 112 void
 113 supported_target_names(std::vector<const char*>* names)
 114 {
 115   for (Target_selector* p = target_selectors; p != NULL; p = p->next())
 116     p->supported_names(names);
 117 }
 118
 119 } // End namespace gold.