runtime/JSNameScope.h

   1 /*
   2  * Copyright (C) 2008, 2009 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 JSNameScope_h
  27 #define JSNameScope_h
  28
  29 #include "JSGlobalObject.h"
  30 #include "JSVariableObject.h"
  31
  32 namespace JSC {
  33
  34 // Used for scopes with a single named variable: catch and named function expression.
  35 class JSNameScope : public JSVariableObject {
  36 public:
  37     typedef JSVariableObject Base;
  38
  39     static JSNameScope* create(ExecState* exec, const Identifier& identifier, JSValue value, unsigned attributes)
  40     {
  41         JSNameScope* scopeObject = new (NotNull, allocateCell<JSNameScope>(*exec->heap())) JSNameScope(exec, exec->scope());
  42         scopeObject->finishCreation(exec, identifier, value, attributes);
  43         return scopeObject;
  44     }
  45
  46     static JSNameScope* create(ExecState* exec, const Identifier& identifier, JSValue value, unsigned attributes, JSScope* next)
  47     {
  48         JSNameScope* scopeObject = new (NotNull, allocateCell<JSNameScope>(*exec->heap())) JSNameScope(exec, next);
  49         scopeObject->finishCreation(exec, identifier, value, attributes);
  50         return scopeObject;
  51     }
  52
  53     static void visitChildren(JSCell*, SlotVisitor&);
  54     bool isDynamicScope(bool& requiresDynamicChecks) const;
  55     static JSObject* toThisObject(JSCell*, ExecState*);
  56     static bool getOwnPropertySlot(JSCell*, ExecState*, PropertyName, PropertySlot&);
  57     static void put(JSCell*, ExecState*, PropertyName, JSValue, PutPropertySlot&);
  58
  59     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue proto) { return Structure::create(vm, globalObject, proto, TypeInfo(NameScopeObjectType, StructureFlags), &s_info); }
  60
  61     static const ClassInfo s_info;
  62
  63 protected:
  64     void finishCreation(ExecState* exec, const Identifier& identifier, JSValue value, unsigned attributes)
  65     {
  66         Base::finishCreation(exec->vm());
  67         m_registerStore.set(exec->vm(), this, value);
  68         symbolTable()->add(identifier.impl(), SymbolTableEntry(-1, attributes));
  69     }
  70
  71     static const unsigned StructureFlags = OverridesGetOwnPropertySlot | OverridesVisitChildren | Base::StructureFlags;
  72
  73 private:
  74     JSNameScope(ExecState* exec, JSScope* next)
  75         : Base(
  76             exec->vm(),
  77             exec->lexicalGlobalObject()->nameScopeStructure(),
  78             reinterpret_cast<Register*>(&m_registerStore + 1),
  79             next
  80         )
  81     {
  82     }
  83
  84     WriteBarrier<Unknown> m_registerStore;
  85 };
  86
  87 inline bool JSNameScope::isDynamicScope(bool&) const
  88 {
  89     return false;
  90 }
  91
  92 }
  93
  94 #endif // JSNameScope_h