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 #include <wtf/Platform.h>
  30
  31 #include <MacroAssemblerCodeRef.h>
  32
  33 #if ENABLE(ASSEMBLER)
  34
  35 namespace JSC {
  36
  37 class CodeLocationInstruction;
  38 class CodeLocationLabel;
  39 class CodeLocationJump;
  40 class CodeLocationCall;
  41 class CodeLocationNearCall;
  42 class CodeLocationDataLabel32;
  43 class CodeLocationDataLabelPtr;
  44
  45 // The CodeLocation* types are all pretty much do-nothing wrappers around
  46 // CodePtr (or MacroAssemblerCodePtr, to give it its full name).  These
  47 // classes only exist to provide type-safety when linking and patching code.
  48 //
  49 // The one new piece of functionallity introduced by these classes is the
  50 // ability to create (or put another way, to re-discover) another CodeLocation
  51 // at an offset from one you already know.  When patching code to optimize it
  52 // we often want to patch a number of instructions that are short, fixed
  53 // offsets apart.  To reduce memory overhead we will only retain a pointer to
  54 // one of the instructions, and we will use the *AtOffset methods provided by
  55 // CodeLocationCommon to find the other points in the code to modify.
  56 class CodeLocationCommon : public MacroAssemblerCodePtr {
  57 public:
  58     CodeLocationInstruction instructionAtOffset(int offset);
  59     CodeLocationLabel labelAtOffset(int offset);
  60     CodeLocationJump jumpAtOffset(int offset);
  61     CodeLocationCall callAtOffset(int offset);
  62     CodeLocationNearCall nearCallAtOffset(int offset);
  63     CodeLocationDataLabelPtr dataLabelPtrAtOffset(int offset);
  64     CodeLocationDataLabel32 dataLabel32AtOffset(int offset);
  65
  66 protected:
  67     CodeLocationCommon()
  68     {
  69     }
  70
  71     CodeLocationCommon(MacroAssemblerCodePtr location)
  72         : MacroAssemblerCodePtr(location)
  73     {
  74     }
  75 };
  76
  77 class CodeLocationInstruction : public CodeLocationCommon {
  78 public:
  79     CodeLocationInstruction() {}
  80     explicit CodeLocationInstruction(MacroAssemblerCodePtr location)
  81         : CodeLocationCommon(location) {}
  82     explicit CodeLocationInstruction(void* location)
  83         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
  84 };
  85
  86 class CodeLocationLabel : public CodeLocationCommon {
  87 public:
  88     CodeLocationLabel() {}
  89     explicit CodeLocationLabel(MacroAssemblerCodePtr location)
  90         : CodeLocationCommon(location) {}
  91     explicit CodeLocationLabel(void* location)
  92         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
  93 };
  94
  95 class CodeLocationJump : public CodeLocationCommon {
  96 public:
  97     CodeLocationJump() {}
  98     explicit CodeLocationJump(MacroAssemblerCodePtr location)
  99         : CodeLocationCommon(location) {}
 100     explicit CodeLocationJump(void* location)
 101         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 102 };
 103
 104 class CodeLocationCall : public CodeLocationCommon {
 105 public:
 106     CodeLocationCall() {}
 107     explicit CodeLocationCall(MacroAssemblerCodePtr location)
 108         : CodeLocationCommon(location) {}
 109     explicit CodeLocationCall(void* location)
 110         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 111 };
 112
 113 class CodeLocationNearCall : public CodeLocationCommon {
 114 public:
 115     CodeLocationNearCall() {}
 116     explicit CodeLocationNearCall(MacroAssemblerCodePtr location)
 117         : CodeLocationCommon(location) {}
 118     explicit CodeLocationNearCall(void* location)
 119         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 120 };
 121
 122 class CodeLocationDataLabel32 : public CodeLocationCommon {
 123 public:
 124     CodeLocationDataLabel32() {}
 125     explicit CodeLocationDataLabel32(MacroAssemblerCodePtr location)
 126         : CodeLocationCommon(location) {}
 127     explicit CodeLocationDataLabel32(void* location)
 128         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 129 };
 130
 131 class CodeLocationDataLabelPtr : public CodeLocationCommon {
 132 public:
 133     CodeLocationDataLabelPtr() {}
 134     explicit CodeLocationDataLabelPtr(MacroAssemblerCodePtr location)
 135         : CodeLocationCommon(location) {}
 136     explicit CodeLocationDataLabelPtr(void* location)
 137         : CodeLocationCommon(MacroAssemblerCodePtr(location)) {}
 138 };
 139
 140 inline CodeLocationInstruction CodeLocationCommon::instructionAtOffset(int offset)
 141 {
 142     ASSERT_VALID_CODE_OFFSET(offset);
 143     return CodeLocationInstruction(reinterpret_cast<char*>(dataLocation()) + offset);
 144 }
 145
 146 inline CodeLocationLabel CodeLocationCommon::labelAtOffset(int offset)
 147 {
 148     ASSERT_VALID_CODE_OFFSET(offset);
 149     return CodeLocationLabel(reinterpret_cast<char*>(dataLocation()) + offset);
 150 }
 151
 152 inline CodeLocationJump CodeLocationCommon::jumpAtOffset(int offset)
 153 {
 154     ASSERT_VALID_CODE_OFFSET(offset);
 155     return CodeLocationJump(reinterpret_cast<char*>(dataLocation()) + offset);
 156 }
 157
 158 inline CodeLocationCall CodeLocationCommon::callAtOffset(int offset)
 159 {
 160     ASSERT_VALID_CODE_OFFSET(offset);
 161     return CodeLocationCall(reinterpret_cast<char*>(dataLocation()) + offset);
 162 }
 163
 164 inline CodeLocationNearCall CodeLocationCommon::nearCallAtOffset(int offset)
 165 {
 166     ASSERT_VALID_CODE_OFFSET(offset);
 167     return CodeLocationNearCall(reinterpret_cast<char*>(dataLocation()) + offset);
 168 }
 169
 170 inline CodeLocationDataLabelPtr CodeLocationCommon::dataLabelPtrAtOffset(int offset)
 171 {
 172     ASSERT_VALID_CODE_OFFSET(offset);
 173     return CodeLocationDataLabelPtr(reinterpret_cast<char*>(dataLocation()) + offset);
 174 }
 175
 176 inline CodeLocationDataLabel32 CodeLocationCommon::dataLabel32AtOffset(int offset)
 177 {
 178     ASSERT_VALID_CODE_OFFSET(offset);
 179     return CodeLocationDataLabel32(reinterpret_cast<char*>(dataLocation()) + offset);
 180 }
 181
 182 } // namespace JSC
 183
 184 #endif // ENABLE(ASSEMBLER)
 185
 186 #endif // CodeLocation_h