1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
// target-select.h -- select a target for an object file -*- C++ -*-
// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
#ifndef GOLD_TARGET_SELECT_H
#define GOLD_TARGET_SELECT_H
#include <vector>
namespace gold
{
class Target;
// We want to avoid a master list of targets, which implies using a
// global constructor. And we also want the program to start up as
// quickly as possible, which implies avoiding global constructors.
// We compromise on a very simple global constructor. We use a target
// selector, which specifies an ELF machine number and a recognition
// function. We use global constructors to build a linked list of
// target selectors--a simple pointer list, not a std::list.
class Target_selector
{
public:
// Create a target selector for a specific machine number, size (32
// or 64), and endianness. The machine number can be EM_NONE to
// test for any machine number. BFD_NAME is the name of the target
// used by the GNU linker, for backward compatibility; it may be
// NULL.
Target_selector(int machine, int size, bool is_big_endian,
const char* bfd_name);
virtual ~Target_selector()
{ }
// If we can handle this target, return a pointer to a target
// structure. The size and endianness are known.
Target*
recognize(int machine, int osabi, int abiversion)
{ return this->do_recognize(machine, osabi, abiversion); }
// If NAME matches the target, return a pointer to a target
// structure.
Target*
recognize_by_name(const char* name)
{ return this->do_recognize_by_name(name); }
// Push all supported names onto the vector. This is only used for
// help output.
void
supported_names(std::vector<const char*>* names)
{ this->do_supported_names(names); }
// Return the next Target_selector in the linked list.
Target_selector*
next() const
{ return this->next_; }
// Return the machine number this selector is looking for. This can
// be EM_NONE to match any machine number, in which case the
// do_recognize hook will be responsible for matching the machine
// number.
int
machine() const
{ return this->machine_; }
// Return the size this is looking for (32 or 64).
int
get_size() const
{ return this->size_; }
// Return the endianness this is looking for.
bool
is_big_endian() const
{ return this->is_big_endian_; }
// Return the BFD name. This may return NULL, in which case the
// do_recognize_by_name hook will be responsible for matching the
// BFD name.
const char*
bfd_name() const
{ return this->bfd_name_; }
protected:
// Return an instance of the real target. This must be implemented
// by the child class.
virtual Target*
do_instantiate_target() = 0;
// Recognize an object file given a machine code, OSABI code, and
// ELF version value. When this is called we already know that they
// match the machine_, size_, and is_big_endian_ fields. The child
// class may implement a different version of this to do additional
// checks, or to check for multiple machine codes if the machine_
// field is EM_NONE.
virtual Target*
do_recognize(int, int, int)
{ return this->instantiate_target(); }
// Recognize a target by name. When this is called we already know
// that the name matches (or that the bfd_name_ field is NULL). The
// child class may implement a different version of this to
// recognize more than one name.
virtual Target*
do_recognize_by_name(const char*)
{ return this->instantiate_target(); }
// Return a list of supported BFD names. The child class may
// implement a different version of this to handle more than one
// name.
virtual void
do_supported_names(std::vector<const char*>* names)
{
gold_assert(this->bfd_name_ != NULL);
names->push_back(this->bfd_name_);
}
// Instantiate the target and return it.
Target*
instantiate_target()
{
if (this->instantiated_target_ == NULL)
this->instantiated_target_ = this->do_instantiate_target();
return this->instantiated_target_;
}
private:
// ELF machine code.
const int machine_;
// Target size--32 or 64.
const int size_;
// Whether the target is big endian.
const bool is_big_endian_;
// BFD name of target, for compatibility.
const char* const bfd_name_;
// Next entry in list built at global constructor time.
Target_selector* next_;
// The singleton Target structure--this points to an instance of the
// real implementation.
Target* instantiated_target_;
};
// Select the target for an ELF file.
extern Target*
select_target(int machine, int size, bool big_endian, int osabi,
int abiversion);
// Select a target using a BFD name.
extern Target*
select_target_by_name(const char* name);
// Fill in a vector with the list of supported targets. This returns
// a list of BFD names.
extern void
supported_target_names(std::vector<const char*>*);
} // End namespace gold.
#endif // !defined(GOLD_TARGET_SELECT_H)
|
