runtime/JSCallee.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 JSCallee_h
  27 #define JSCallee_h
  28
  29 #include "JSGlobalObject.h"
  30 #include "JSObject.h"
  31 #include "JSScope.h"
  32
  33 namespace JSC {
  34
  35 class JSGlobalObject;
  36 class LLIntOffsetsExtractor;
  37
  38
  39 class JSCallee : public JSNonFinalObject {
  40     friend class JIT;
  41 #if ENABLE(DFG_JIT)
  42     friend class DFG::SpeculativeJIT;
  43     friend class DFG::JITCompiler;
  44 #endif
  45     friend class VM;
  46
  47 public:
  48     typedef JSNonFinalObject Base;
  49     const static unsigned StructureFlags = Base::StructureFlags | ImplementsHasInstance;
  50
  51     static JSCallee* create(VM& vm, JSGlobalObject* globalObject, JSScope* scope)
  52     {
  53         JSCallee* callee = new (NotNull, allocateCell<JSCallee>(vm.heap)) JSCallee(vm, scope, globalObject->calleeStructure());
  54         callee->finishCreation(vm);
  55         return callee;
  56     }
  57
  58     JSScope* scope()
  59     {
  60         return m_scope.get();
  61     }
  62
  63     // This method may be called for host functions, in which case it
  64     // will return an arbitrary value. This should only be used for
  65     // optimized paths in which the return value does not matter for
  66     // host functions, and checking whether the function is a host
  67     // function is deemed too expensive.
  68     JSScope* scopeUnchecked()
  69     {
  70         return m_scope.get();
  71     }
  72
  73     void setScope(VM& vm, JSScope* scope)
  74     {
  75         m_scope.set(vm, this, scope);
  76     }
  77
  78     DECLARE_EXPORT_INFO;
  79
  80     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
  81     {
  82         ASSERT(globalObject);
  83         return Structure::create(vm, globalObject, prototype, TypeInfo(JSCalleeType, StructureFlags), info());
  84     }
  85
  86     static inline ptrdiff_t offsetOfScopeChain()
  87     {
  88         return OBJECT_OFFSETOF(JSCallee, m_scope);
  89     }
  90
  91 protected:
  92     JS_EXPORT_PRIVATE JSCallee(VM&, JSGlobalObject*, Structure*);
  93     JSCallee(VM&, JSScope*, Structure*);
  94
  95     void finishCreation(VM&);
  96     using Base::finishCreation;
  97
  98     static void visitChildren(JSCell*, SlotVisitor&);
  99
 100 private:
 101     friend class LLIntOffsetsExtractor;
 102
 103     WriteBarrier<JSScope> m_scope;
 104 };
 105
 106 } // namespace JSC
 107
 108 #endif // JSCallee_h