LCOV - code coverage report
Current view: directory - js/src/assembler/assembler - MacroAssemblerCodeRef.h (source / functions) Found Hit Coverage
Test: app.info Lines: 32 32 100.0 %
Date: 2012-06-02 Functions: 11 11 100.0 %

       1                 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
       2                 :  * vim: set ts=8 sw=4 et tw=79:
       3                 :  *
       4                 :  * ***** BEGIN LICENSE BLOCK *****
       5                 :  * Copyright (C) 2009 Apple Inc. All rights reserved.
       6                 :  *
       7                 :  * Redistribution and use in source and binary forms, with or without
       8                 :  * modification, are permitted provided that the following conditions
       9                 :  * are met:
      10                 :  * 1. Redistributions of source code must retain the above copyright
      11                 :  *    notice, this list of conditions and the following disclaimer.
      12                 :  * 2. Redistributions in binary form must reproduce the above copyright
      13                 :  *    notice, this list of conditions and the following disclaimer in the
      14                 :  *    documentation and/or other materials provided with the distribution.
      15                 :  *
      16                 :  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
      17                 :  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      18                 :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
      19                 :  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
      20                 :  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
      21                 :  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
      22                 :  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
      23                 :  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
      24                 :  * 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                 :  * ***** END LICENSE BLOCK ***** */
      29                 : 
      30                 : #ifndef MacroAssemblerCodeRef_h
      31                 : #define MacroAssemblerCodeRef_h
      32                 : 
      33                 : #include "assembler/wtf/Platform.h"
      34                 : #include "assembler/jit/ExecutableAllocator.h"
      35                 : 
      36                 : #if ENABLE_ASSEMBLER
      37                 : 
      38                 : // ASSERT_VALID_CODE_POINTER checks that ptr is a non-null pointer, and that it is a valid
      39                 : // instruction address on the platform (for example, check any alignment requirements).
      40                 : #if WTF_CPU_ARM_THUMB2
      41                 : // ARM/thumb instructions must be 16-bit aligned, but all code pointers to be loaded
      42                 : // into the processor are decorated with the bottom bit set, indicating that this is
      43                 : // thumb code (as oposed to 32-bit traditional ARM).  The first test checks for both
      44                 : // decorated and undectorated null, and the second test ensures that the pointer is
      45                 : // decorated.
      46                 : #define ASSERT_VALID_CODE_POINTER(ptr) \
      47                 :     ASSERT(reinterpret_cast<intptr_t>(ptr) & ~1); \
      48                 :     ASSERT(reinterpret_cast<intptr_t>(ptr) & 1)
      49                 : #define ASSERT_VALID_CODE_OFFSET(offset) \
      50                 :     ASSERT(!(offset & 1)) // Must be multiple of 2.
      51                 : #else
      52                 : #define ASSERT_VALID_CODE_POINTER(ptr) \
      53                 :     ASSERT(ptr)
      54                 : #define ASSERT_VALID_CODE_OFFSET(offset) // Anything goes!
      55                 : #endif
      56                 : 
      57                 : namespace JSC {
      58                 : 
      59                 : // FunctionPtr:
      60                 : //
      61                 : // FunctionPtr should be used to wrap pointers to C/C++ functions in JSC
      62                 : // (particularly, the stub functions).
      63                 : class FunctionPtr {
      64                 : public:
      65                 :     FunctionPtr()
      66                 :         : m_value(0)
      67                 :     {
      68                 :     }
      69                 : 
      70                 :     template<typename FunctionType>
      71         4972081 :     explicit FunctionPtr(FunctionType* value)
      72                 : #if WTF_COMPILER_RVCT
      73                 :      // RVTC compiler needs C-style cast as it fails with the following error
      74                 :      // Error:  #694: reinterpret_cast cannot cast away const or other type qualifiers
      75                 :         : m_value((void*)(value))
      76                 : #else
      77         4972081 :         : m_value(reinterpret_cast<void*>(value))
      78                 : #endif
      79                 :     {
      80         4972081 :         ASSERT_VALID_CODE_POINTER(m_value);
      81         4972081 :     }
      82                 : 
      83         4905105 :     void* value() const { return m_value; }
      84           66466 :     void* executableAddress() const { return m_value; }
      85                 : 
      86                 : 
      87                 : private:
      88                 :     void* m_value;
      89                 : };
      90                 : 
      91                 : // ReturnAddressPtr:
      92                 : //
      93                 : // ReturnAddressPtr should be used to wrap return addresses generated by processor
      94                 : // 'call' instructions exectued in JIT code.  We use return addresses to look up
      95                 : // exception and optimization information, and to repatch the call instruction
      96                 : // that is the source of the return address.
      97                 : class ReturnAddressPtr {
      98                 : public:
      99                 :     ReturnAddressPtr()
     100                 :         : m_value(0)
     101                 :     {
     102                 :     }
     103                 : 
     104                 :     explicit ReturnAddressPtr(void* value)
     105                 :         : m_value(value)
     106                 :     {
     107                 :         ASSERT_VALID_CODE_POINTER(m_value);
     108                 :     }
     109                 : 
     110                 :     explicit ReturnAddressPtr(FunctionPtr function)
     111                 :         : m_value(function.value())
     112                 :     {
     113                 :         ASSERT_VALID_CODE_POINTER(m_value);
     114                 :     }
     115                 : 
     116                 :     void* value() const { return m_value; }
     117                 : 
     118                 : private:
     119                 :     void* m_value;
     120                 : };
     121                 : 
     122                 : // MacroAssemblerCodePtr:
     123                 : //
     124                 : // MacroAssemblerCodePtr should be used to wrap pointers to JIT generated code.
     125                 : class MacroAssemblerCodePtr {
     126                 : public:
     127         3805799 :     MacroAssemblerCodePtr()
     128         3805799 :         : m_value(0)
     129                 :     {
     130         3805799 :     }
     131                 : 
     132        21304096 :     explicit MacroAssemblerCodePtr(void* value)
     133                 : #if WTF_CPU_ARM_THUMB2
     134                 :         // Decorate the pointer as a thumb code pointer.
     135                 :         : m_value(reinterpret_cast<char*>(value) + 1)
     136                 : #else
     137        21304096 :         : m_value(value)
     138                 : #endif
     139                 :     {
     140        21304096 :         ASSERT_VALID_CODE_POINTER(m_value);
     141        21304096 :     }
     142                 : 
     143                 :     explicit MacroAssemblerCodePtr(ReturnAddressPtr ra)
     144                 :         : m_value(ra.value())
     145                 :     {
     146                 :         ASSERT_VALID_CODE_POINTER(m_value);
     147                 :     }
     148                 : 
     149        10901957 :     void* executableAddress() const {
     150        10901957 :         return m_value;
     151                 :     }
     152                 : #if WTF_CPU_ARM_THUMB2
     153                 :     // To use this pointer as a data address remove the decoration.
     154                 :     void* dataLocation() const { ASSERT_VALID_CODE_POINTER(m_value); return reinterpret_cast<char*>(m_value) - 1; }
     155                 : #else
     156        13864731 :     void* dataLocation() const { ASSERT_VALID_CODE_POINTER(m_value); return m_value; }
     157                 : #endif
     158                 : 
     159                 :     bool operator!()
     160                 :     {
     161                 :         return !m_value;
     162                 :     }
     163                 : 
     164         1975904 :     ptrdiff_t operator -(const MacroAssemblerCodePtr &other) const
     165                 :     {
     166         1975904 :         JS_ASSERT(m_value);
     167                 :         return reinterpret_cast<uint8_t *>(m_value) -
     168         1975904 :                reinterpret_cast<uint8_t *>(other.m_value);
     169                 :     }
     170                 : 
     171                 : private:
     172                 :     void* m_value;
     173                 : };
     174                 : 
     175                 : // MacroAssemblerCodeRef:
     176                 : //
     177                 : // A reference to a section of JIT generated code.  A CodeRef consists of a
     178                 : // pointer to the code, and a ref pointer to the pool from within which it
     179                 : // was allocated.
     180                 : class MacroAssemblerCodeRef {
     181                 : public:
     182          187071 :     MacroAssemblerCodeRef()
     183                 :         : m_executablePool(NULL),
     184          187071 :           m_size(0)
     185                 :     {
     186          187071 :     }
     187                 : 
     188          184096 :     MacroAssemblerCodeRef(void* code, ExecutablePool* executablePool, size_t size)
     189                 :         : m_code(code)
     190                 :         , m_executablePool(executablePool)
     191          184096 :         , m_size(size)
     192                 :     {
     193          184096 :     }
     194                 : 
     195                 :     // Release the code memory in this code ref.
     196          187071 :     void release()
     197                 :     {
     198          187071 :         if (!m_executablePool)
     199            2975 :             return;
     200                 : 
     201                 : #if defined DEBUG && (defined WTF_CPU_X86 || defined WTF_CPU_X86_64) 
     202          184096 :         void *addr = m_code.executableAddress();
     203          184096 :         memset(addr, 0xcc, m_size);
     204                 : #endif
     205          184096 :         m_executablePool->release();
     206          184096 :         m_executablePool = NULL;
     207                 :     }
     208                 : 
     209                 :     MacroAssemblerCodePtr m_code;
     210                 :     ExecutablePool* m_executablePool;
     211                 :     size_t m_size;
     212                 : };
     213                 : 
     214                 : } // namespace JSC
     215                 : 
     216                 : #endif // ENABLE(ASSEMBLER)
     217                 : 
     218                 : #endif // MacroAssemblerCodeRef_h

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