1/*
2 * Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
3 * Copyright (C) 2007-2008, 2016 Apple Inc. All rights reserved.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 */
20
21#pragma once
22
23#include "JSWrapperObject.h"
24#include "JSString.h"
25
26namespace JSC {
27
28class StringObject : public JSWrapperObject {
29public:
30 using Base = JSWrapperObject;
31 static const unsigned StructureFlags = Base::StructureFlags | OverridesGetOwnPropertySlot | InterceptsGetOwnPropertySlotByIndexEvenWhenLengthIsNotZero | OverridesGetPropertyNames;
32
33 static StringObject* create(VM& vm, Structure* structure)
34 {
35 JSString* string = jsEmptyString(&vm);
36 StringObject* object = new (NotNull, allocateCell<StringObject>(vm.heap)) StringObject(vm, structure);
37 object->finishCreation(vm, string);
38 return object;
39 }
40 static StringObject* create(VM& vm, Structure* structure, JSString* string)
41 {
42 StringObject* object = new (NotNull, allocateCell<StringObject>(vm.heap)) StringObject(vm, structure);
43 object->finishCreation(vm, string);
44 return object;
45 }
46 static StringObject* create(VM&, JSGlobalObject*, JSString*);
47
48 JS_EXPORT_PRIVATE static bool getOwnPropertySlot(JSObject*, ExecState*, PropertyName, PropertySlot&);
49 JS_EXPORT_PRIVATE static bool getOwnPropertySlotByIndex(JSObject*, ExecState*, unsigned propertyName, PropertySlot&);
50
51 JS_EXPORT_PRIVATE static bool put(JSCell*, ExecState*, PropertyName, JSValue, PutPropertySlot&);
52 JS_EXPORT_PRIVATE static bool putByIndex(JSCell*, ExecState*, unsigned propertyName, JSValue, bool shouldThrow);
53
54 JS_EXPORT_PRIVATE static bool deleteProperty(JSCell*, ExecState*, PropertyName);
55 JS_EXPORT_PRIVATE static bool deletePropertyByIndex(JSCell*, ExecState*, unsigned propertyName);
56 JS_EXPORT_PRIVATE static void getOwnPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
57 JS_EXPORT_PRIVATE static void getOwnNonIndexPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
58 JS_EXPORT_PRIVATE static bool defineOwnProperty(JSObject*, ExecState*, PropertyName, const PropertyDescriptor&, bool shouldThrow);
59
60 DECLARE_EXPORT_INFO;
61
62 JSString* internalValue() const { return asString(JSWrapperObject::internalValue()); }
63
64 static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
65 {
66 return Structure::create(vm, globalObject, prototype, TypeInfo(StringObjectType, StructureFlags), info());
67 }
68
69protected:
70 JS_EXPORT_PRIVATE void finishCreation(VM&, JSString*);
71 JS_EXPORT_PRIVATE StringObject(VM&, Structure*);
72};
73
74JS_EXPORT_PRIVATE StringObject* constructString(VM&, JSGlobalObject*, JSValue);
75
76// Helper for producing a JSString for 'string', where 'string' was been produced by
77// calling ToString on 'originalValue'. In cases where 'originalValue' already was a
78// string primitive we can just use this, otherwise we need to allocate a new JSString.
79// FIXME: Basically any use of this is bad. toString() returns a JSString* so we don't need to
80// pass around the originalValue; we could just pass around the JSString*. Then you don't need
81// this function. You just use the JSString* that toString() returned.
82static inline JSString* jsStringWithReuse(ExecState* exec, JSValue originalValue, const String& string)
83{
84 if (originalValue.isString()) {
85 ASSERT(asString(originalValue)->value(exec) == string);
86 return asString(originalValue);
87 }
88 return jsString(&exec->vm(), string);
89}
90
91// Helper that tries to use the JSString substring sharing mechanism if 'originalValue' is a JSString.
92// FIXME: Basically any use of this is bad. toString() returns a JSString* so we don't need to
93// pass around the originalValue; we could just pass around the JSString*. And since we've
94// resolved it, we know that we can just allocate the substring cell directly.
95// https://bugs.webkit.org/show_bug.cgi?id=158140
96static inline JSString* jsSubstring(ExecState* exec, JSValue originalValue, const String& string, unsigned offset, unsigned length)
97{
98 if (originalValue.isString()) {
99 ASSERT(asString(originalValue)->value(exec) == string);
100 return jsSubstring(exec, asString(originalValue), offset, length);
101 }
102 return jsSubstring(&exec->vm(), string, offset, length);
103}
104
105} // namespace JSC
106