Source/JavaScriptCore/runtime/JSModuleEnvironment.h

/*
 * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 */

#pragma once

#include "JSLexicalEnvironment.h"

namespace JSC {

class AbstractModuleRecord;
class Register;

class JSModuleEnvironment final : public JSLexicalEnvironment {
    friend class JIT;
    friend class LLIntOffsetsExtractor;
public:
    using Base = JSLexicalEnvironment;
    static constexpr unsigned StructureFlags = Base::StructureFlags | OverridesGetOwnPropertySlot | OverridesAnyFormOfGetPropertyNames;

    static JSModuleEnvironment* create(VM& vm, JSGlobalObject* globalObject, JSScope* currentScope, SymbolTable* symbolTable, JSValue initialValue, AbstractModuleRecord* moduleRecord)
    {
        Structure* structure = globalObject->moduleEnvironmentStructure();
        return create(vm, structure, currentScope, symbolTable, initialValue, moduleRecord);
    }

    DECLARE_INFO;

    static Structure* createStructure(VM& vm, JSGlobalObject* globalObject)
    {
        return Structure::create(vm, globalObject, jsNull(), TypeInfo(ModuleEnvironmentType, StructureFlags), info());
    }

    static size_t offsetOfModuleRecord(SymbolTable* symbolTable)
    {
        size_t offset = Base::allocationSize(symbolTable);
        ASSERT(WTF::roundUpToMultipleOf<sizeof(WriteBarrier<AbstractModuleRecord>)>(offset) == offset);
        return offset;
    }

    static size_t allocationSize(SymbolTable* symbolTable)
    {
        return offsetOfModuleRecord(symbolTable) + sizeof(WriteBarrier<AbstractModuleRecord>);
    }

    AbstractModuleRecord* moduleRecord()
    {
        return moduleRecordSlot().get();
    }

    static bool getOwnPropertySlot(JSObject*, JSGlobalObject*, PropertyName, PropertySlot&);
    static void getOwnNonIndexPropertyNames(JSObject*, JSGlobalObject*, PropertyNameArray&, EnumerationMode);
    static bool put(JSCell*, JSGlobalObject*, PropertyName, JSValue, PutPropertySlot&);
    static bool deleteProperty(JSCell*, JSGlobalObject*, PropertyName, DeletePropertySlot&);

private:
    JSModuleEnvironment(VM&, Structure*, JSScope*, SymbolTable*);

    static JSModuleEnvironment* create(VM&, Structure*, JSScope*, SymbolTable*, JSValue initialValue, AbstractModuleRecord*);

    void finishCreation(VM&, JSValue initialValue, AbstractModuleRecord*);

    WriteBarrierBase<AbstractModuleRecord>& moduleRecordSlot()
    {
        return *bitwise_cast<WriteBarrierBase<AbstractModuleRecord>*>(bitwise_cast<char*>(this) + offsetOfModuleRecord(symbolTable()));
    }

    static void visitChildren(JSCell*, SlotVisitor&);
};

inline JSModuleEnvironment::JSModuleEnvironment(VM& vm, Structure* structure, JSScope* currentScope, SymbolTable* symbolTable)
    : Base(vm, structure, currentScope, symbolTable)
{
}

} // namespace JSC