1// target-select.cc -- select a target for an object file 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#include "gold.h" 24 25#include <cstring> 26 27#include "elfcpp.h" 28#include "target-select.h" 29 30namespace 31{ 32 33// The start of the list of target selectors. 34 35gold::Target_selector* target_selectors; 36 37} // End anonymous namespace. 38 39namespace gold 40{ 41 42// Class Set_target_once. 43 44void 45Set_target_once::do_run_once(void*) 46{ 47 this->target_selector_->set_target(); 48} 49 50// Construct a Target_selector, which means adding it to the linked 51// list. This runs at global constructor time, so we want it to be 52// fast. 53 54Target_selector::Target_selector(int machine, int size, bool is_big_endian, 55 const char* bfd_name) 56 : machine_(machine), size_(size), is_big_endian_(is_big_endian), 57 bfd_name_(bfd_name), instantiated_target_(NULL), set_target_once_(this) 58{ 59 this->next_ = target_selectors; 60 target_selectors = this; 61} 62 63// Instantiate the target and return it. Use SET_TARGET_ONCE_ to 64// avoid instantiating two instances of the same target. 65 66Target* 67Target_selector::instantiate_target() 68{ 69 this->set_target_once_.run_once(NULL); 70 return this->instantiated_target_; 71} 72 73// Instantiate the target. This is called at most once. 74 75void 76Target_selector::set_target() 77{ 78 gold_assert(this->instantiated_target_ == NULL); 79 this->instantiated_target_ = this->do_instantiate_target(); 80} 81 82// Find the target for an ELF file. 83 84Target* 85select_target(int machine, int size, bool is_big_endian, int osabi, 86 int abiversion) 87{ 88 for (Target_selector* p = target_selectors; p != NULL; p = p->next()) 89 { 90 int pmach = p->machine(); 91 if ((pmach == machine || pmach == elfcpp::EM_NONE) 92 && p->get_size() == size 93 && (p->is_big_endian() ? is_big_endian : !is_big_endian)) 94 { 95 Target* ret = p->recognize(machine, osabi, abiversion); 96 if (ret != NULL) 97 return ret; 98 } 99 } 100 return NULL; 101} 102 103// Find a target using a BFD name. This is used to support the 104// --oformat option. 105 106Target* 107select_target_by_name(const char* name) 108{ 109 for (Target_selector* p = target_selectors; p != NULL; p = p->next()) 110 { 111 const char* pname = p->bfd_name(); 112 if (pname == NULL || strcmp(pname, name) == 0) 113 { 114 Target* ret = p->recognize_by_name(name); 115 if (ret != NULL) 116 return ret; 117 } 118 } 119 return NULL; 120} 121 122// Push all the supported BFD names onto a vector. 123 124void 125supported_target_names(std::vector<const char*>* names) 126{ 127 for (Target_selector* p = target_selectors; p != NULL; p = p->next()) 128 p->supported_names(names); 129} 130 131} // End namespace gold. 132