bytecode/PutByIdVariant.h

   1 /*
   2  * Copyright (C) 2014 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 PutByIdVariant_h
  27 #define PutByIdVariant_h
  28
  29 #include "IntendedStructureChain.h"
  30 #include "PropertyOffset.h"
  31 #include "StructureSet.h"
  32
  33 namespace JSC {
  34
  35 class CallLinkStatus;
  36
  37 class PutByIdVariant {
  38 public:
  39     enum Kind {
  40         NotSet,
  41         Replace,
  42         Transition,
  43         Setter
  44     };
  45
  46     PutByIdVariant()
  47         : m_kind(NotSet)
  48         , m_newStructure(nullptr)
  49         , m_alternateBase(nullptr)
  50         , m_offset(invalidOffset)
  51     {
  52     }
  53
  54     PutByIdVariant(const PutByIdVariant&);
  55     PutByIdVariant& operator=(const PutByIdVariant&);
  56
  57     static PutByIdVariant replace(
  58         const StructureSet& structure, PropertyOffset offset);
  59
  60     static PutByIdVariant transition(
  61         const StructureSet& oldStructure, Structure* newStructure,
  62         const IntendedStructureChain* structureChain, PropertyOffset offset);
  63
  64     static PutByIdVariant setter(
  65         const StructureSet& structure, PropertyOffset offset,
  66         IntendedStructureChain* chain, std::unique_ptr<CallLinkStatus> callLinkStatus);
  67
  68     Kind kind() const { return m_kind; }
  69
  70     bool isSet() const { return kind() != NotSet; }
  71     bool operator!() const { return !isSet(); }
  72
  73     const StructureSet& structure() const
  74     {
  75         ASSERT(kind() == Replace || kind() == Setter);
  76         return m_oldStructure;
  77     }
  78
  79     const StructureSet& oldStructure() const
  80     {
  81         ASSERT(kind() == Transition || kind() == Replace || kind() == Setter);
  82         return m_oldStructure;
  83     }
  84
  85     StructureSet& oldStructure()
  86     {
  87         ASSERT(kind() == Transition || kind() == Replace || kind() == Setter);
  88         return m_oldStructure;
  89     }
  90
  91     Structure* oldStructureForTransition() const;
  92
  93     Structure* newStructure() const
  94     {
  95         ASSERT(kind() == Transition);
  96         return m_newStructure;
  97     }
  98
  99     bool writesStructures() const;
 100     bool reallocatesStorage() const;
 101     bool makesCalls() const;
 102
 103     const ConstantStructureCheckVector& constantChecks() const
 104     {
 105         return m_constantChecks;
 106     }
 107
 108     PropertyOffset offset() const
 109     {
 110         ASSERT(isSet());
 111         return m_offset;
 112     }
 113
 114     JSObject* alternateBase() const
 115     {
 116         ASSERT(kind() == Setter);
 117         return m_alternateBase;
 118     }
 119
 120     StructureSet baseStructure() const;
 121
 122     CallLinkStatus* callLinkStatus() const
 123     {
 124         ASSERT(kind() == Setter);
 125         return m_callLinkStatus.get();
 126     }
 127
 128     bool attemptToMerge(const PutByIdVariant& other);
 129
 130     void dump(PrintStream&) const;
 131     void dumpInContext(PrintStream&, DumpContext*) const;
 132
 133 private:
 134     bool attemptToMergeTransitionWithReplace(const PutByIdVariant& replace);
 135
 136     Kind m_kind;
 137     StructureSet m_oldStructure;
 138     Structure* m_newStructure;
 139     ConstantStructureCheckVector m_constantChecks;
 140     JSObject* m_alternateBase;
 141     PropertyOffset m_offset;
 142     std::unique_ptr<CallLinkStatus> m_callLinkStatus;
 143 };
 144
 145 } // namespace JSC
 146
 147 #endif // PutByIdVariant_h
 148