1/*
2 * Copyright (C) 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef RegisterID_h
30#define RegisterID_h
31
32#include <wtf/Assertions.h>
33#include <wtf/Noncopyable.h>
34#include <wtf/VectorTraits.h>
35
36namespace JSC {
37
38    class RegisterID : public Noncopyable {
39    public:
40        RegisterID()
41            : m_refCount(0)
42            , m_isTemporary(false)
43#ifndef NDEBUG
44            , m_didSetIndex(false)
45#endif
46        {
47        }
48
49        explicit RegisterID(int index)
50            : m_refCount(0)
51            , m_index(index)
52            , m_isTemporary(false)
53#ifndef NDEBUG
54            , m_didSetIndex(true)
55#endif
56        {
57        }
58
59        void setIndex(int index)
60        {
61            ASSERT(!m_refCount);
62#ifndef NDEBUG
63            m_didSetIndex = true;
64#endif
65            m_index = index;
66        }
67
68        void setTemporary()
69        {
70            m_isTemporary = true;
71        }
72
73        int index() const
74        {
75            ASSERT(m_didSetIndex);
76            return m_index;
77        }
78
79        bool isTemporary()
80        {
81            return m_isTemporary;
82        }
83
84        void ref()
85        {
86            ++m_refCount;
87        }
88
89        void deref()
90        {
91            --m_refCount;
92            ASSERT(m_refCount >= 0);
93        }
94
95        int refCount() const
96        {
97            return m_refCount;
98        }
99
100    private:
101
102        int m_refCount;
103        int m_index;
104        bool m_isTemporary;
105#ifndef NDEBUG
106        bool m_didSetIndex;
107#endif
108    };
109
110} // namespace JSC
111
112namespace WTF {
113
114    template<> struct VectorTraits<JSC::RegisterID> : VectorTraitsBase<true, JSC::RegisterID> {
115        static const bool needsInitialization = true;
116        static const bool canInitializeWithMemset = true; // Default initialization just sets everything to 0 or false, so this is safe.
117    };
118
119} // namespace WTF
120
121#endif // RegisterID_h
122