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