bytecode/GetByIdStatus.h

   1 /*
   2  * Copyright (C) 2012 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 GetByIdStatus_h
  27 #define GetByIdStatus_h
  28
  29 #include "StructureSet.h"
  30 #include <wtf/NotFound.h>
  31
  32 namespace JSC {
  33
  34 class CodeBlock;
  35 class Identifier;
  36
  37 class GetByIdStatus {
  38 public:
  39     enum State {
  40         NoInformation,  // It's uncached so we have no information.
  41         SimpleDirect,   // It's cached for a direct access to a known object property.
  42         TakesSlowPath,  // It's known to often take slow path.
  43         MakesCalls      // It's known to take paths that make calls.
  44     };
  45
  46     GetByIdStatus()
  47         : m_state(NoInformation)
  48         , m_offset(notFound)
  49     {
  50     }
  51
  52     GetByIdStatus(State state, const StructureSet& structureSet, size_t offset, bool wasSeenInJIT)
  53         : m_state(state)
  54         , m_structureSet(structureSet)
  55         , m_offset(offset)
  56         , m_wasSeenInJIT(wasSeenInJIT)
  57     {
  58         ASSERT((state == SimpleDirect) == (offset != notFound));
  59     }
  60
  61     static GetByIdStatus computeFor(CodeBlock*, unsigned bytecodeIndex, Identifier&);
  62
  63     State state() const { return m_state; }
  64
  65     bool isSet() const { return m_state != NoInformation; }
  66     bool operator!() const { return !isSet(); }
  67     bool isSimpleDirect() const { return m_state == SimpleDirect; }
  68     bool takesSlowPath() const { return m_state == TakesSlowPath || m_state == MakesCalls; }
  69     bool makesCalls() const { return m_state == MakesCalls; }
  70
  71     const StructureSet& structureSet() const { return m_structureSet; }
  72     size_t offset() const { return m_offset; }
  73
  74     bool wasSeenInJIT() const { return m_wasSeenInJIT; }
  75
  76 private:
  77     static GetByIdStatus computeFromLLInt(CodeBlock*, unsigned bytecodeIndex, Identifier&);
  78
  79     State m_state;
  80     StructureSet m_structureSet;
  81     size_t m_offset;
  82     bool m_wasSeenInJIT;
  83 };
  84
  85 } // namespace JSC
  86
  87 #endif // PropertyAccessStatus_h
  88