1/*
2 * Copyright (C) 2013-2017 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#include "config.h"
27#include "StructureCache.h"
28
29#include "IndexingType.h"
30#include "JSGlobalObject.h"
31#include "JSCInlines.h"
32
33namespace JSC {
34
35inline Structure* StructureCache::createEmptyStructure(JSGlobalObject* globalObject, JSObject* prototype, const TypeInfo& typeInfo, const ClassInfo* classInfo, IndexingType indexingType, unsigned inlineCapacity, bool makePolyProtoStructure, FunctionExecutable* executable)
36{
37 RELEASE_ASSERT(!!prototype); // We use nullptr inside the HashMap for prototype to mean poly proto, so user's of this API must provide non-null prototypes.
38
39 PrototypeKey key { makePolyProtoStructure ? nullptr : prototype, executable, inlineCapacity, classInfo, globalObject };
40 if (Structure* structure = m_structures.get(key)) {
41 if (makePolyProtoStructure) {
42 prototype->didBecomePrototype();
43 RELEASE_ASSERT(structure->hasPolyProto());
44 } else
45 RELEASE_ASSERT(structure->hasMonoProto());
46 ASSERT(prototype->mayBePrototype());
47 return structure;
48 }
49
50 prototype->didBecomePrototype();
51
52 VM& vm = globalObject->vm();
53 Structure* structure;
54 if (makePolyProtoStructure) {
55 structure = Structure::create(
56 Structure::PolyProto, vm, globalObject, prototype, typeInfo, classInfo, indexingType, inlineCapacity);
57 } else {
58 structure = Structure::create(
59 vm, globalObject, prototype, typeInfo, classInfo, indexingType, inlineCapacity);
60 }
61 m_structures.set(key, structure);
62
63 return structure;
64}
65
66Structure* StructureCache::emptyStructureForPrototypeFromBaseStructure(JSGlobalObject* globalObject, JSObject* prototype, Structure* baseStructure)
67{
68 // We currently do not have inline capacity static analysis for subclasses and all internal function constructors have a default inline capacity of 0.
69 IndexingType indexingType = baseStructure->indexingType();
70 if (prototype->anyObjectInChainMayInterceptIndexedAccesses(globalObject->vm()) && hasIndexedProperties(indexingType))
71 indexingType = (indexingType & ~IndexingShapeMask) | SlowPutArrayStorageShape;
72
73 return createEmptyStructure(globalObject, prototype, baseStructure->typeInfo(), baseStructure->classInfo(), indexingType, 0, false, nullptr);
74}
75
76Structure* StructureCache::emptyObjectStructureForPrototype(JSGlobalObject* globalObject, JSObject* prototype, unsigned inlineCapacity, bool makePolyProtoStructure, FunctionExecutable* executable)
77{
78 return createEmptyStructure(globalObject, prototype, JSFinalObject::typeInfo(), JSFinalObject::info(), JSFinalObject::defaultIndexingType, inlineCapacity, makePolyProtoStructure, executable);
79}
80
81} // namespace JSC
82