assembler/CodeLocation.h

   1 /*
   2  * Copyright (C) 2009 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  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. 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  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef CodeLocation_h
  27 #define CodeLocation_h
  28
  29
  30 #include <MacroAssemblerCodeRef.h>
  31
  32 #if ENABLE(ASSEMBLER)
  33
  34 namespace JSC {
  35
  36 class CodeLocationInstruction;
  37 class CodeLocationLabel;
  38 class CodeLocationJump;
  39 class CodeLocationCall;
  40 class CodeLocationNearCall;
  41 class CodeLocationDataLabel32;
  42 class CodeLocationDataLabelPtr;
  43
  44 // The CodeLocation* types are all pretty much do-nothing wrappers around
  45 // CodePtr (or MacroAssemblerCodePtr, to give it its full name).  These
  46 // classes only exist to provide type-safety when linking and patching code.
  47 //
  48 // The one new piece of functionallity introduced by these classes is the
  49 // ability to create (or put another way, to re-discover) another CodeLocation
  50 // at an offset from one you already know.  When patching code to optimize it
  51 // we often want to patch a number of instructions that are short, fixed
  52 // offsets apart.  To reduce memory overhead we will only retain a pointer to
  53 // one of the instructions, and we will use the *AtOffset methods provided by
  54 // CodeLocationCommon to find the other points in the code to modify.
  55 class CodeLocationCommon : public MacroAssemblerCodePtr {
  56 public:
  57     CodeLocationInstruction instructionAtOffset(int offset);
  58     CodeLocationLabel labelAtOffset(int offset);
  59     CodeLocationJump jumpAtOffset(int offset);
  60     CodeLocationCall callAtOffset(int offset);
  61     CodeLocationNearCall nearCallAtOffset(int offset);
  62     CodeLocationDataLabelPtr dataLabelPtrAtOffset(int offset);
  63     CodeLocationDataLabel32 dataLabel32AtOffset(int offset);
  64
  65 protected:
  66     CodeLocationCommon()
  67     {
  68     }
  69
  70     CodeLocationCommon(MacroAssemblerCodePtr location)
  71         : MacroAssemblerCodePtr(location)
  72     {
  73     }
  74 };
  75
  76 class CodeLocationInstruction : public CodeLocationCommon {
  77 public:
  78     CodeLocationInstruction() {}
  79     explicit CodeLocationInstruction(MacroAssemblerCodePtr location)
  80         : CodeLocationCommon(location) {}
  81     explicit CodeLocationInstruction(void* location)
  82         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
  83 };
  84
  85 class CodeLocationLabel : public CodeLocationCommon {
  86 public:
  87     CodeLocationLabel() {}
  88     explicit CodeLocationLabel(MacroAssemblerCodePtr location)
  89         : CodeLocationCommon(location) {}
  90     explicit CodeLocationLabel(void* location)
  91         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
  92 };
  93
  94 class CodeLocationJump : public CodeLocationCommon {
  95 public:
  96     CodeLocationJump() {}
  97     explicit CodeLocationJump(MacroAssemblerCodePtr location)
  98         : CodeLocationCommon(location) {}
  99     explicit CodeLocationJump(void* location)
 100         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 101 };
 102
 103 class CodeLocationCall : public CodeLocationCommon {
 104 public:
 105     CodeLocationCall() {}
 106     explicit CodeLocationCall(MacroAssemblerCodePtr location)
 107         : CodeLocationCommon(location) {}
 108     explicit CodeLocationCall(void* location)
 109         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 110 };
 111
 112 class CodeLocationNearCall : public CodeLocationCommon {
 113 public:
 114     CodeLocationNearCall() {}
 115     explicit CodeLocationNearCall(MacroAssemblerCodePtr location)
 116         : CodeLocationCommon(location) {}
 117     explicit CodeLocationNearCall(void* location)
 118         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 119 };
 120
 121 class CodeLocationDataLabel32 : public CodeLocationCommon {
 122 public:
 123     CodeLocationDataLabel32() {}
 124     explicit CodeLocationDataLabel32(MacroAssemblerCodePtr location)
 125         : CodeLocationCommon(location) {}
 126     explicit CodeLocationDataLabel32(void* location)
 127         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 128 };
 129
 130 class CodeLocationDataLabelPtr : public CodeLocationCommon {
 131 public:
 132     CodeLocationDataLabelPtr() {}
 133     explicit CodeLocationDataLabelPtr(MacroAssemblerCodePtr location)
 134         : CodeLocationCommon(location) {}
 135     explicit CodeLocationDataLabelPtr(void* location)
 136         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 137 };
 138
 139 inline CodeLocationInstruction CodeLocationCommon::instructionAtOffset(int offset)
 140 {
 141     ASSERT_VALID_CODE_OFFSET(offset);
 142     return CodeLocationInstruction(reinterpret_cast<char*>(dataLocation()) + offset);
 143 }
 144
 145 inline CodeLocationLabel CodeLocationCommon::labelAtOffset(int offset)
 146 {
 147     ASSERT_VALID_CODE_OFFSET(offset);
 148     return CodeLocationLabel(reinterpret_cast<char*>(dataLocation()) + offset);
 149 }
 150
 151 inline CodeLocationJump CodeLocationCommon::jumpAtOffset(int offset)
 152 {
 153     ASSERT_VALID_CODE_OFFSET(offset);
 154     return CodeLocationJump(reinterpret_cast<char*>(dataLocation()) + offset);
 155 }
 156
 157 inline CodeLocationCall CodeLocationCommon::callAtOffset(int offset)
 158 {
 159     ASSERT_VALID_CODE_OFFSET(offset);
 160     return CodeLocationCall(reinterpret_cast<char*>(dataLocation()) + offset);
 161 }
 162
 163 inline CodeLocationNearCall CodeLocationCommon::nearCallAtOffset(int offset)
 164 {
 165     ASSERT_VALID_CODE_OFFSET(offset);
 166     return CodeLocationNearCall(reinterpret_cast<char*>(dataLocation()) + offset);
 167 }
 168
 169 inline CodeLocationDataLabelPtr CodeLocationCommon::dataLabelPtrAtOffset(int offset)
 170 {
 171     ASSERT_VALID_CODE_OFFSET(offset);
 172     return CodeLocationDataLabelPtr(reinterpret_cast<char*>(dataLocation()) + offset);
 173 }
 174
 175 inline CodeLocationDataLabel32 CodeLocationCommon::dataLabel32AtOffset(int offset)
 176 {
 177     ASSERT_VALID_CODE_OFFSET(offset);
 178     return CodeLocationDataLabel32(reinterpret_cast<char*>(dataLocation()) + offset);
 179 }
 180
 181 } // namespace JSC
 182
 183 #endif // ENABLE(ASSEMBLER)
 184
 185 #endif // CodeLocation_h