1/*
2 * Copyright (C) 2007, 2008 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 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef JSVariableObject_h
30#define JSVariableObject_h
31
32#include "JSObject.h"
33#include "Register.h"
34#include "SymbolTable.h"
35#include "UnusedParam.h"
36#include <wtf/OwnArrayPtr.h>
37#include <wtf/UnusedParam.h>
38
39namespace JSC {
40
41 class Register;
42
43 class JSVariableObject : public JSObject {
44 friend class JIT;
45
46 public:
47 SymbolTable& symbolTable() const { return *d->symbolTable; }
48
49 virtual void putWithAttributes(ExecState*, const Identifier&, JSValue, unsigned attributes) = 0;
50
51 virtual bool deleteProperty(ExecState*, const Identifier&);
52 virtual void getOwnPropertyNames(ExecState*, PropertyNameArray&, EnumerationMode mode = ExcludeDontEnumProperties);
53
54 virtual bool isVariableObject() const;
55 virtual bool isDynamicScope() const = 0;
56
57 Register& registerAt(int index) const { return d->registers[index]; }
58
59 static PassRefPtr<Structure> createStructure(JSValue prototype)
60 {
61 return Structure::create(prototype, typeInfo: TypeInfo(ObjectType, StructureFlags));
62 }
63
64 protected:
65 static const unsigned StructureFlags = OverridesGetPropertyNames | JSObject::StructureFlags;
66 // Subclasses of JSVariableObject can subclass this struct to add data
67 // without increasing their own size (since there's a hard limit on the
68 // size of a JSCell).
69 struct JSVariableObjectData {
70 JSVariableObjectData(SymbolTable* symbolTable, Register* registers)
71 : symbolTable(symbolTable)
72 , registers(registers)
73 {
74 ASSERT(symbolTable);
75 }
76
77 SymbolTable* symbolTable; // Maps name -> offset from "r" in register file.
78 Register* registers; // "r" in the register file.
79 OwnArrayPtr<Register> registerArray; // Independent copy of registers, used when a variable object copies its registers out of the register file.
80
81 private:
82 JSVariableObjectData(const JSVariableObjectData&);
83 JSVariableObjectData& operator=(const JSVariableObjectData&);
84 };
85
86 JSVariableObject(NonNullPassRefPtr<Structure> structure, JSVariableObjectData* data)
87 : JSObject(structure)
88 , d(data) // Subclass owns this pointer.
89 {
90 }
91
92 Register* copyRegisterArray(Register* src, size_t count);
93 void setRegisters(Register* r, Register* registerArray);
94
95 bool symbolTableGet(const Identifier&, PropertySlot&);
96 bool symbolTableGet(const Identifier&, PropertyDescriptor&);
97 bool symbolTableGet(const Identifier&, PropertySlot&, bool& slotIsWriteable);
98 bool symbolTablePut(const Identifier&, JSValue);
99 bool symbolTablePutWithAttributes(const Identifier&, JSValue, unsigned attributes);
100
101 JSVariableObjectData* d;
102 };
103
104 inline bool JSVariableObject::symbolTableGet(const Identifier& propertyName, PropertySlot& slot)
105 {
106 SymbolTableEntry entry = symbolTable().inlineGet(key: propertyName.ustring().rep());
107 if (!entry.isNull()) {
108 slot.setRegisterSlot(&registerAt(index: entry.getIndex()));
109 return true;
110 }
111 return false;
112 }
113
114 inline bool JSVariableObject::symbolTableGet(const Identifier& propertyName, PropertySlot& slot, bool& slotIsWriteable)
115 {
116 SymbolTableEntry entry = symbolTable().inlineGet(key: propertyName.ustring().rep());
117 if (!entry.isNull()) {
118 slot.setRegisterSlot(&registerAt(index: entry.getIndex()));
119 slotIsWriteable = !entry.isReadOnly();
120 return true;
121 }
122 return false;
123 }
124
125 inline bool JSVariableObject::symbolTablePut(const Identifier& propertyName, JSValue value)
126 {
127 ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
128
129 SymbolTableEntry entry = symbolTable().inlineGet(key: propertyName.ustring().rep());
130 if (entry.isNull())
131 return false;
132 if (entry.isReadOnly())
133 return true;
134 registerAt(index: entry.getIndex()) = value;
135 return true;
136 }
137
138 inline bool JSVariableObject::symbolTablePutWithAttributes(const Identifier& propertyName, JSValue value, unsigned attributes)
139 {
140 ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
141
142 SymbolTable::iterator iter = symbolTable().find(key: propertyName.ustring().rep());
143 if (iter == symbolTable().end())
144 return false;
145 SymbolTableEntry& entry = iter->second;
146 ASSERT(!entry.isNull());
147 entry.setAttributes(attributes);
148 registerAt(index: entry.getIndex()) = value;
149 return true;
150 }
151
152 inline Register* JSVariableObject::copyRegisterArray(Register* src, size_t count)
153 {
154 Register* registerArray = new Register[count];
155 memcpy(dest: registerArray, src: src, n: count * sizeof(Register));
156
157 return registerArray;
158 }
159
160 inline void JSVariableObject::setRegisters(Register* registers, Register* registerArray)
161 {
162 ASSERT(registerArray != d->registerArray.get());
163 d->registerArray.set(registerArray);
164 d->registers = registers;
165 }
166
167} // namespace JSC
168
169#endif // JSVariableObject_h
170

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/runtime/JSVariableObject.h