bytecode/GetByIdStatus.h

   1 /*
   2  * Copyright (C) 2012, 2013, 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 GetByIdStatus_h
  27 #define GetByIdStatus_h
  28
  29 #include "CodeOrigin.h"
  30 #include "ConcurrentJITLock.h"
  31 #include "ExitingJITType.h"
  32 #include "GetByIdVariant.h"
  33 #include "StructureStubInfo.h"
  34
  35 namespace JSC {
  36
  37 class CodeBlock;
  38
  39 class GetByIdStatus {
  40 public:
  41     enum State {
  42         NoInformation,  // It's uncached so we have no information.
  43         Simple,         // It's cached for a simple access to a known object property with
  44                         // a possible structure chain and a possible specific value.
  45         TakesSlowPath,  // It's known to often take slow path.
  46         MakesCalls      // It's known to take paths that make calls.
  47     };
  48
  49     GetByIdStatus()
  50         : m_state(NoInformation)
  51     {
  52     }
  53
  54     explicit GetByIdStatus(State state)
  55         : m_state(state)
  56     {
  57         ASSERT(state == NoInformation || state == TakesSlowPath || state == MakesCalls);
  58     }
  59
  60     GetByIdStatus(
  61         State state, bool wasSeenInJIT, const GetByIdVariant& variant = GetByIdVariant())
  62         : m_state(state)
  63         , m_wasSeenInJIT(wasSeenInJIT)
  64     {
  65         ASSERT((state == Simple) == variant.isSet());
  66         m_variants.append(variant);
  67     }
  68
  69     static GetByIdStatus computeFor(CodeBlock*, StubInfoMap&, unsigned bytecodeIndex, StringImpl* uid);
  70     static GetByIdStatus computeFor(VM&, Structure*, StringImpl* uid);
  71
  72     static GetByIdStatus computeFor(CodeBlock* baselineBlock, CodeBlock* dfgBlock, StubInfoMap& baselineMap, StubInfoMap& dfgMap, CodeOrigin, StringImpl* uid);
  73
  74     State state() const { return m_state; }
  75
  76     bool isSet() const { return m_state != NoInformation; }
  77     bool operator!() const { return !isSet(); }
  78     bool isSimple() const { return m_state == Simple; }
  79
  80     size_t numVariants() const { return m_variants.size(); }
  81     const Vector<GetByIdVariant, 1>& variants() const { return m_variants; }
  82     const GetByIdVariant& at(size_t index) const { return m_variants[index]; }
  83     const GetByIdVariant& operator[](size_t index) const { return at(index); }
  84
  85     bool takesSlowPath() const { return m_state == TakesSlowPath || m_state == MakesCalls; }
  86     bool makesCalls() const { return m_state == MakesCalls; }
  87
  88     bool wasSeenInJIT() const { return m_wasSeenInJIT; }
  89
  90     void dump(PrintStream&) const;
  91
  92 private:
  93 #if ENABLE(DFG_JIT)
  94     static bool hasExitSite(const ConcurrentJITLocker&, CodeBlock*, unsigned bytecodeIndex, ExitingJITType = ExitFromAnything);
  95 #endif
  96 #if ENABLE(JIT)
  97     static GetByIdStatus computeForStubInfo(const ConcurrentJITLocker&, CodeBlock*, StructureStubInfo*, StringImpl* uid);
  98 #endif
  99     bool computeForChain(CodeBlock*, StringImpl* uid, PassRefPtr<IntendedStructureChain>);
 100     static GetByIdStatus computeFromLLInt(CodeBlock*, unsigned bytecodeIndex, StringImpl* uid);
 101
 102     bool appendVariant(const GetByIdVariant&);
 103
 104     State m_state;
 105     Vector<GetByIdVariant, 1> m_variants;
 106     bool m_wasSeenInJIT;
 107 };
 108
 109 } // namespace JSC
 110
 111 #endif // PropertyAccessStatus_h
 112