source: webkit/trunk/JavaScriptCore/runtime/JSFunction.h@ 48048

Last change on this file since 48048 was 47780, checked in by [email protected], 16 years ago

[ES5] Implement getOwnPropertyDescriptor
https://bugs.webkit.org/show_bug.cgi?id=28724

Reviewed by Gavin Barraclough.

JavaScriptCore:
Implement the core runtime support for getOwnPropertyDescriptor.
This adds a virtual getOwnPropertyDescriptor method to every class
that implements getOwnPropertySlot that shadows the behaviour of
getOwnPropertySlot. The alternative would be to make getOwnPropertySlot
(or PropertySlots in general) provide property attribute information,
but quick testing showed this to be a regression.

WebCore:
Implement the WebCore side of getOwnPropertyDescriptor. This
requires a custom implementation of getOwnPropertyDescriptor
for every class with a custom implementation of getOwnPropertySlot.

The bindings generator has been updated to generate appropriate
versions of getOwnPropertyDescriptor for the general case where
a custom getOwnPropertyDescriptor is not needed. ES5 is vague
about how getOwnPropertyDescriptor should work in the context of
"host" functions with polymorphic GetOwnProperty, so it seems
okay that occasionally we "guess" what attributes -- eg. determining
whether a property is writable.

Test: fast/js/getOwnPropertyDescriptor.html

  • Property svn:eol-style set to native
File size: 4.5 KB
Line 
1/*
2 * Copyright (C) 1999-2000 Harri Porten ([email protected])
3 * Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
4 * Copyright (C) 2007 Cameron Zwarich ([email protected])
5 * Copyright (C) 2007 Maks Orlovich
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
16 *
17 * You should have received a copy of the GNU Library General Public License
18 * along with this library; see the file COPYING.LIB. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
21 *
22 */
23
24#ifndef JSFunction_h
25#define JSFunction_h
26
27#include "InternalFunction.h"
28
29namespace JSC {
30
31 class ExecutableBase;
32 class FunctionExecutable;
33 class FunctionPrototype;
34 class JSActivation;
35 class JSGlobalObject;
36
37 class JSFunction : public InternalFunction {
38 friend class JIT;
39 friend struct VPtrSet;
40
41 typedef InternalFunction Base;
42
43 public:
44 JSFunction(ExecState*, PassRefPtr<Structure>, int length, const Identifier&, NativeFunction);
45 JSFunction(ExecState*, PassRefPtr<FunctionExecutable>, ScopeChainNode*);
46 virtual ~JSFunction();
47
48 JSObject* construct(ExecState*, const ArgList&);
49 JSValue call(ExecState*, JSValue thisValue, const ArgList&);
50
51 void setScope(const ScopeChain& scopeChain) { setScopeChain(scopeChain); }
52 ScopeChain& scope() { return scopeChain(); }
53
54 ExecutableBase* executable() const { return m_executable.get(); }
55
56 // To call either of these methods include Executable.h
57 inline bool isHostFunction() const;
58 FunctionExecutable* jsExecutable() const;
59
60 static JS_EXPORTDATA const ClassInfo info;
61
62 static PassRefPtr<Structure> createStructure(JSValue prototype)
63 {
64 return Structure::create(prototype, TypeInfo(ObjectType, ImplementsHasInstance));
65 }
66
67 NativeFunction nativeFunction()
68 {
69 return *reinterpret_cast<NativeFunction*>(m_data);
70 }
71
72 virtual ConstructType getConstructData(ConstructData&);
73 virtual CallType getCallData(CallData&);
74
75 private:
76 JSFunction(PassRefPtr<Structure>);
77
78 bool isHostFunctionNonInline() const;
79
80 virtual bool getOwnPropertySlot(ExecState*, const Identifier&, PropertySlot&);
81 virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);
82 virtual void put(ExecState*, const Identifier& propertyName, JSValue, PutPropertySlot&);
83 virtual bool deleteProperty(ExecState*, const Identifier& propertyName);
84
85 virtual void markChildren(MarkStack&);
86
87 virtual const ClassInfo* classInfo() const { return &info; }
88
89 static JSValue argumentsGetter(ExecState*, const Identifier&, const PropertySlot&);
90 static JSValue callerGetter(ExecState*, const Identifier&, const PropertySlot&);
91 static JSValue lengthGetter(ExecState*, const Identifier&, const PropertySlot&);
92
93 RefPtr<ExecutableBase> m_executable;
94 ScopeChain& scopeChain()
95 {
96 ASSERT(!isHostFunctionNonInline());
97 return *reinterpret_cast<ScopeChain*>(m_data);
98 }
99 void clearScopeChain()
100 {
101 ASSERT(!isHostFunctionNonInline());
102 new (m_data) ScopeChain(NoScopeChain());
103 }
104 void setScopeChain(ScopeChainNode* sc)
105 {
106 ASSERT(!isHostFunctionNonInline());
107 new (m_data) ScopeChain(sc);
108 }
109 void setScopeChain(const ScopeChain& sc)
110 {
111 ASSERT(!isHostFunctionNonInline());
112 *reinterpret_cast<ScopeChain*>(m_data) = sc;
113 }
114 void setNativeFunction(NativeFunction func)
115 {
116 *reinterpret_cast<NativeFunction*>(m_data) = func;
117 }
118 unsigned char m_data[sizeof(void*)];
119 };
120
121 JSFunction* asFunction(JSValue);
122
123 inline JSFunction* asFunction(JSValue value)
124 {
125 ASSERT(asObject(value)->inherits(&JSFunction::info));
126 return static_cast<JSFunction*>(asObject(value));
127 }
128
129} // namespace JSC
130
131#endif // JSFunction_h
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