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[binutils.git] / gold / target-select.h
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1 // target-select.h -- select a target for an object file -*- C++ -*-
3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
23 #ifndef GOLD_TARGET_SELECT_H
24 #define GOLD_TARGET_SELECT_H
26 #include <vector>
28 namespace gold
31 class Target;
33 // We want to avoid a master list of targets, which implies using a
34 // global constructor. And we also want the program to start up as
35 // quickly as possible, which implies avoiding global constructors.
36 // We compromise on a very simple global constructor. We use a target
37 // selector, which specifies an ELF machine number and a recognition
38 // function. We use global constructors to build a linked list of
39 // target selectors--a simple pointer list, not a std::list.
41 class Target_selector
43 public:
44 // Create a target selector for a specific machine number, size (32
45 // or 64), and endianness. The machine number can be EM_NONE to
46 // test for any machine number. BFD_NAME is the name of the target
47 // used by the GNU linker, for backward compatibility; it may be
48 // NULL.
49 Target_selector(int machine, int size, bool is_big_endian,
50 const char* bfd_name);
52 virtual ~Target_selector()
53 { }
55 // If we can handle this target, return a pointer to a target
56 // structure. The size and endianness are known.
57 Target*
58 recognize(int machine, int osabi, int abiversion)
59 { return this->do_recognize(machine, osabi, abiversion); }
61 // If NAME matches the target, return a pointer to a target
62 // structure.
63 Target*
64 recognize_by_name(const char* name)
65 { return this->do_recognize_by_name(name); }
67 // Push all supported names onto the vector. This is only used for
68 // help output.
69 void
70 supported_names(std::vector<const char*>* names)
71 { this->do_supported_names(names); }
73 // Return the next Target_selector in the linked list.
74 Target_selector*
75 next() const
76 { return this->next_; }
78 // Return the machine number this selector is looking for. This can
79 // be EM_NONE to match any machine number, in which case the
80 // do_recognize hook will be responsible for matching the machine
81 // number.
82 int
83 machine() const
84 { return this->machine_; }
86 // Return the size this is looking for (32 or 64).
87 int
88 get_size() const
89 { return this->size_; }
91 // Return the endianness this is looking for.
92 bool
93 is_big_endian() const
94 { return this->is_big_endian_; }
96 // Return the BFD name. This may return NULL, in which case the
97 // do_recognize_by_name hook will be responsible for matching the
98 // BFD name.
99 const char*
100 bfd_name() const
101 { return this->bfd_name_; }
103 protected:
104 // Return an instance of the real target. This must be implemented
105 // by the child class.
106 virtual Target*
107 do_instantiate_target() = 0;
109 // Recognize an object file given a machine code, size, and
110 // endianness. When this is called we already know that they match
111 // the machine_, size_, and is_big_endian_ fields. The child class
112 // may implement a different version of this to do additional
113 // checks, or to check for multiple machine codes if the machine_
114 // field is EM_NONE.
115 virtual Target*
116 do_recognize(int, int, int)
117 { return this->instantiate_target(); }
119 // Recognize a target by name. When this is called we already know
120 // that the name matches (or that the bfd_name_ field is NULL). The
121 // child class may implement a different version of this to
122 // recognize more than one name.
123 virtual Target*
124 do_recognize_by_name(const char*)
125 { return this->instantiate_target(); }
127 // Return a list of supported BFD names. The child class may
128 // implement a different version of this to handle more than one
129 // name.
130 virtual void
131 do_supported_names(std::vector<const char*>* names)
133 gold_assert(this->bfd_name_ != NULL);
134 names->push_back(this->bfd_name_);
137 private:
138 // Instantiate the target and return it.
139 Target*
140 instantiate_target()
142 if (this->instantiated_target_ == NULL)
143 this->instantiated_target_ = this->do_instantiate_target();
144 return this->instantiated_target_;
147 // ELF machine code.
148 const int machine_;
149 // Target size--32 or 64.
150 const int size_;
151 // Whether the target is big endian.
152 const bool is_big_endian_;
153 // BFD name of target, for compatibility.
154 const char* const bfd_name_;
155 // Next entry in list built at global constructor time.
156 Target_selector* next_;
157 // The singleton Target structure--this points to an instance of the
158 // real implementation.
159 Target* instantiated_target_;
162 // Select the target for an ELF file.
164 extern Target*
165 select_target(int machine, int size, bool big_endian, int osabi,
166 int abiversion);
168 // Select a target using a BFD name.
170 extern Target*
171 select_target_by_name(const char* name);
173 // Fill in a vector with the list of supported targets. This returns
174 // a list of BFD names.
176 extern void
177 supported_target_names(std::vector<const char*>*);
179 } // End namespace gold.
181 #endif // !defined(GOLD_TARGET_SELECT_H)