vptr.hh revision 1762 
1/*
2 * Copyright (c) 2004-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef __ARCH_ALPHA_VPTR_HH__
30#define __ARCH_ALPHA_VPTR_HH__
31
32#include "arch/alpha/vtophys.hh"
33
34class ExecContext;
35
36template <class T>
37class VPtr
38{
39  public:
40    typedef T Type;
41
42  private:
43    ExecContext *xc;
44    Addr ptr;
45
46  public:
47    ExecContext *GetXC() const { return xc; }
48    Addr GetPointer() const { return ptr; }
49
50  public:
51    explicit VPtr(ExecContext *_xc, Addr p = 0) : xc(_xc), ptr(p) { }
52    template <class U>
53    VPtr(const VPtr<U> &vp) : xc(vp.GetXC()), ptr(vp.GetPointer()) {}
54    ~VPtr() {}
55
56    bool operator!() const
57    {
58        return ptr == 0;
59    }
60
61    VPtr<T> operator+(int offset)
62    {
63        VPtr<T> ptr(*this);
64        ptr += offset;
65
66        return ptr;
67    }
68
69    const VPtr<T> &operator+=(int offset)
70    {
71        ptr += offset;
72        assert((ptr & (AlphaISA::PageBytes - 1)) + sizeof(T)
73               < AlphaISA::PageBytes);
74
75        return *this;
76    }
77
78    const VPtr<T> &operator=(Addr p)
79    {
80        assert((p & (AlphaISA::PageBytes)) + sizeof(T) < AlphaISA::PageBytes);
81        ptr = p;
82
83        return *this;
84    }
85
86    template <class U>
87    const VPtr<T> &operator=(const VPtr<U> &vp)
88    {
89        xc = vp.GetXC();
90        ptr = vp.GetPointer();
91
92        return *this;
93    }
94
95    operator T *()
96    {
97        void *addr = vtomem(xc, ptr, sizeof(T));
98        return (T *)addr;
99    }
100
101    T *operator->()
102    {
103        void *addr = vtomem(xc, ptr, sizeof(T));
104        return (T *)addr;
105    }
106
107    T &operator*()
108    {
109        void *addr = vtomem(xc, ptr, sizeof(T));
110        return *(T *)addr;
111    }
112};
113
114#endif // __ARCH_ALPHA_VPTR_HH__
115