runtime/IntendedStructureChain.h

   1 /*
   2  * Copyright (C) 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 IntendedStructureChain_h
  27 #define IntendedStructureChain_h
  28
  29 #include "ConstantStructureCheck.h"
  30 #include "Structure.h"
  31 #include <wtf/RefCounted.h>
  32
  33 namespace JSC {
  34
  35 class CodeBlock;
  36 class JSGlobalObject;
  37 class StructureChain;
  38 class VM;
  39 struct DumpContext;
  40
  41 class IntendedStructureChain : public RefCounted<IntendedStructureChain> {
  42 public:
  43     IntendedStructureChain(JSGlobalObject* globalObject, JSValue prototype);
  44     IntendedStructureChain(JSGlobalObject* globalObject, Structure*);
  45     IntendedStructureChain(CodeBlock* codeBlock, Structure* head, Structure* prototypeStructure);
  46     IntendedStructureChain(CodeBlock* codeBlock, Structure* head, StructureChain* chain);
  47     IntendedStructureChain(CodeBlock* codeBlock, Structure* head, StructureChain* chain, unsigned count);
  48     ~IntendedStructureChain();
  49
  50     bool isStillValid() const;
  51     bool matches(StructureChain*) const;
  52     bool mayInterceptStoreTo(UniquedStringImpl* uid);
  53     bool isNormalized();
  54
  55     bool takesSlowPathInDFGForImpureProperty();
  56
  57     JSValue prototype() const { return m_prototype; }
  58
  59     size_t size() const { return m_vector.size(); }
  60     Structure* at(size_t index) const { return m_vector[index]; }
  61     Structure* operator[](size_t index) const { return at(index); }
  62
  63     JSObject* terminalPrototype() const;
  64
  65     Structure* last() const { return m_vector.last(); }
  66
  67     bool operator==(const IntendedStructureChain&) const;
  68     bool operator!=(const IntendedStructureChain& other) const
  69     {
  70         return !(*this == other);
  71     }
  72
  73     void gatherChecks(ConstantStructureCheckVector&) const;
  74
  75     void visitChildren(SlotVisitor&);
  76     void dump(PrintStream&) const;
  77     void dumpInContext(PrintStream&, DumpContext*) const;
  78
  79 private:
  80     JSGlobalObject* m_globalObject;
  81     JSValue m_prototype;
  82     Vector<Structure*> m_vector;
  83 };
  84
  85 } // namespace JSC
  86
  87 #endif // IntendedStructureChain_h