C++ JSGlobalObject::hasProperty方法代码示例

JSObject* ProgramExecutable::initializeGlobalProperties(JSGlobalData& globalData, CallFrame* callFrame, JSScope* scope)
{
    ASSERT(scope);
    JSGlobalObject* globalObject = scope->globalObject();
    ASSERT(globalObject);
    ASSERT(&globalObject->globalData() == &globalData);

    JSObject* exception = 0;
    UnlinkedProgramCodeBlock* unlinkedCode = globalObject->createProgramCodeBlock(callFrame, this, &exception);
    if (exception)
        return exception;

    m_unlinkedProgramCodeBlock.set(globalData, this, unlinkedCode);

    BatchedTransitionOptimizer optimizer(globalData, globalObject);

    const UnlinkedProgramCodeBlock::VariableDeclations& variableDeclarations = unlinkedCode->variableDeclarations();
    const UnlinkedProgramCodeBlock::FunctionDeclations& functionDeclarations = unlinkedCode->functionDeclarations();

    size_t newGlobals = variableDeclarations.size() + functionDeclarations.size();
    if (!newGlobals)
        return 0;
    globalObject->addRegisters(newGlobals);
    CallFrame* globalExec = globalObject->globalExec();

    for (size_t i = 0; i < functionDeclarations.size(); ++i) {
        bool propertyDidExist = globalObject->removeDirect(globalData, functionDeclarations[i].first); // Newly declared functions overwrite existing properties.
        UnlinkedFunctionExecutable* unlinkedFunctionExecutable = functionDeclarations[i].second.get();
        JSValue value = JSFunction::create(globalExec, unlinkedFunctionExecutable->link(globalData, m_source, lineNo(), 0), scope);
        int index = addGlobalVar(globalObject, functionDeclarations[i].first, IsVariable,
            !propertyDidExist ? IsFunctionToSpecialize : NotFunctionOrNotSpecializable);
        globalObject->registerAt(index).set(globalData, globalObject, value);
    }

    for (size_t i = 0; i < variableDeclarations.size(); ++i) {
        if (globalObject->hasProperty(globalExec, variableDeclarations[i].first))
            continue;
        addGlobalVar(globalObject, variableDeclarations[i].first,
            (variableDeclarations[i].second & DeclarationStacks::IsConstant) ? IsConstant : IsVariable,
            NotFunctionOrNotSpecializable);
    }
    return 0;
}

JSObject* ProgramExecutable::initializeGlobalProperties(VM& vm, CallFrame* callFrame, JSScope* scope)
{
    auto throwScope = DECLARE_THROW_SCOPE(vm);
    RELEASE_ASSERT(scope);
    JSGlobalObject* globalObject = scope->globalObject();
    RELEASE_ASSERT(globalObject);
    ASSERT(&globalObject->vm() == &vm);

    ParserError error;
    JSParserStrictMode strictMode = isStrictMode() ? JSParserStrictMode::Strict : JSParserStrictMode::NotStrict;
    DebuggerMode debuggerMode = globalObject->hasInteractiveDebugger() ? DebuggerOn : DebuggerOff;

    UnlinkedProgramCodeBlock* unlinkedCodeBlock = vm.codeCache()->getUnlinkedProgramCodeBlock(
        vm, this, source(), strictMode, debuggerMode, error);

    if (globalObject->hasDebugger())
        globalObject->debugger()->sourceParsed(callFrame, source().provider(), error.line(), error.message());

    if (error.isValid())
        return error.toErrorObject(globalObject, source());

    JSValue nextPrototype = globalObject->getPrototypeDirect();
    while (nextPrototype && nextPrototype.isObject()) {
        if (UNLIKELY(asObject(nextPrototype)->type() == ProxyObjectType)) {
            ExecState* exec = globalObject->globalExec();
            return createTypeError(exec, ASCIILiteral("Proxy is not allowed in the global prototype chain."));
        }
        nextPrototype = asObject(nextPrototype)->getPrototypeDirect();
    }
    
    JSGlobalLexicalEnvironment* globalLexicalEnvironment = globalObject->globalLexicalEnvironment();
    const VariableEnvironment& variableDeclarations = unlinkedCodeBlock->variableDeclarations();
    const VariableEnvironment& lexicalDeclarations = unlinkedCodeBlock->lexicalDeclarations();
    // The ES6 spec says that no vars/global properties/let/const can be duplicated in the global scope.
    // This carried out section 15.1.8 of the ES6 spec: http://www.ecma-international.org/ecma-262/6.0/index.html#sec-globaldeclarationinstantiation
    {
        ExecState* exec = globalObject->globalExec();
        // Check for intersection of "var" and "let"/"const"/"class"
        for (auto& entry : lexicalDeclarations) {
            if (variableDeclarations.contains(entry.key))
                return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
        }

        // Check if any new "let"/"const"/"class" will shadow any pre-existing global property names, or "var"/"let"/"const" variables.
        // It's an error to introduce a shadow.
        for (auto& entry : lexicalDeclarations) {
            bool hasProperty = globalObject->hasProperty(exec, entry.key.get());
            RETURN_IF_EXCEPTION(throwScope, throwScope.exception());
            if (hasProperty) {
                // The ES6 spec says that just RestrictedGlobalProperty can't be shadowed
                // This carried out section 8.1.1.4.14 of the ES6 spec: http://www.ecma-international.org/ecma-262/6.0/index.html#sec-hasrestrictedglobalproperty
                PropertyDescriptor descriptor;
                globalObject->getOwnPropertyDescriptor(exec, entry.key.get(), descriptor);
                
                if (descriptor.value() != jsUndefined() && !descriptor.configurable())
                    return createSyntaxError(exec, makeString("Can't create duplicate variable that shadows a global property: '", String(entry.key.get()), "'"));
            }

            hasProperty = globalLexicalEnvironment->hasProperty(exec, entry.key.get());
            RETURN_IF_EXCEPTION(throwScope, throwScope.exception());
            if (hasProperty) {
                if (UNLIKELY(entry.value.isConst() && !vm.globalConstRedeclarationShouldThrow() && !isStrictMode())) {
                    // We only allow "const" duplicate declarations under this setting.
                    // For example, we don't "let" variables to be overridden by "const" variables.
                    if (globalLexicalEnvironment->isConstVariable(entry.key.get()))
                        continue;
                }
                return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
            }
        }

        // Check if any new "var"s will shadow any previous "let"/"const"/"class" names.
        // It's an error to introduce a shadow.
        if (!globalLexicalEnvironment->isEmpty()) {
            for (auto& entry : variableDeclarations) {
                bool hasProperty = globalLexicalEnvironment->hasProperty(exec, entry.key.get());
                RETURN_IF_EXCEPTION(throwScope, throwScope.exception());
                if (hasProperty)
                    return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
            }
        }
    }


    m_unlinkedProgramCodeBlock.set(vm, this, unlinkedCodeBlock);

    BatchedTransitionOptimizer optimizer(vm, globalObject);

    for (size_t i = 0, numberOfFunctions = unlinkedCodeBlock->numberOfFunctionDecls(); i < numberOfFunctions; ++i) {
        UnlinkedFunctionExecutable* unlinkedFunctionExecutable = unlinkedCodeBlock->functionDecl(i);
        ASSERT(!unlinkedFunctionExecutable->name().isEmpty());
        globalObject->addFunction(callFrame, unlinkedFunctionExecutable->name());
        if (vm.typeProfiler() || vm.controlFlowProfiler()) {
            vm.functionHasExecutedCache()->insertUnexecutedRange(sourceID(), 
                unlinkedFunctionExecutable->typeProfilingStartOffset(), 
                unlinkedFunctionExecutable->typeProfilingEndOffset());
        }
    }

    for (auto& entry : variableDeclarations) {
//.........这里部分代码省略.........

JSObject* ProgramExecutable::initializeGlobalProperties(VM& vm, CallFrame* callFrame, JSScope* scope)
{
    RELEASE_ASSERT(scope);
    JSGlobalObject* globalObject = scope->globalObject();
    RELEASE_ASSERT(globalObject);
    ASSERT(&globalObject->vm() == &vm);

    JSObject* exception = 0;
    UnlinkedProgramCodeBlock* unlinkedCodeBlock = globalObject->createProgramCodeBlock(callFrame, this, &exception);
    if (exception)
        return exception;

    JSGlobalLexicalEnvironment* globalLexicalEnvironment = globalObject->globalLexicalEnvironment();
    const VariableEnvironment& variableDeclarations = unlinkedCodeBlock->variableDeclarations();
    const VariableEnvironment& lexicalDeclarations = unlinkedCodeBlock->lexicalDeclarations();
    // The ES6 spec says that no vars/global properties/let/const can be duplicated in the global scope.
    // This carried out section 15.1.8 of the ES6 spec: http://www.ecma-international.org/ecma-262/6.0/index.html#sec-globaldeclarationinstantiation
    {
        ExecState* exec = globalObject->globalExec();
        // Check for intersection of "var" and "let"/"const"/"class"
        for (auto& entry : lexicalDeclarations) {
            if (variableDeclarations.contains(entry.key))
                return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
        }

        // Check if any new "let"/"const"/"class" will shadow any pre-existing global property names, or "var"/"let"/"const" variables.
        // It's an error to introduce a shadow.
        for (auto& entry : lexicalDeclarations) {
            if (globalObject->hasProperty(exec, entry.key.get()))
                return createSyntaxError(exec, makeString("Can't create duplicate variable that shadows a global property: '", String(entry.key.get()), "'"));

            if (globalLexicalEnvironment->hasProperty(exec, entry.key.get()))
                return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
        }

        // Check if any new "var"s will shadow any previous "let"/"const"/"class" names.
        // It's an error to introduce a shadow.
        if (!globalLexicalEnvironment->isEmpty()) {
            for (auto& entry : variableDeclarations) {
                if (globalLexicalEnvironment->hasProperty(exec, entry.key.get()))
                    return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
            }
        }
    }


    m_unlinkedProgramCodeBlock.set(vm, this, unlinkedCodeBlock);

    BatchedTransitionOptimizer optimizer(vm, globalObject);

    for (size_t i = 0, numberOfFunctions = unlinkedCodeBlock->numberOfFunctionDecls(); i < numberOfFunctions; ++i) {
        UnlinkedFunctionExecutable* unlinkedFunctionExecutable = unlinkedCodeBlock->functionDecl(i);
        ASSERT(!unlinkedFunctionExecutable->name().isEmpty());
        globalObject->addFunction(callFrame, unlinkedFunctionExecutable->name());
        if (vm.typeProfiler() || vm.controlFlowProfiler()) {
            vm.functionHasExecutedCache()->insertUnexecutedRange(sourceID(), 
                unlinkedFunctionExecutable->typeProfilingStartOffset(), 
                unlinkedFunctionExecutable->typeProfilingEndOffset());
        }
    }

    for (auto& entry : variableDeclarations) {
        ASSERT(entry.value.isVar());
        globalObject->addVar(callFrame, Identifier::fromUid(&vm, entry.key.get()));
    }

    {
        JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(globalObject->globalScope());
        SymbolTable* symbolTable = globalLexicalEnvironment->symbolTable();
        ConcurrentJITLocker locker(symbolTable->m_lock);
        for (auto& entry : lexicalDeclarations) {
            ScopeOffset offset = symbolTable->takeNextScopeOffset(locker);
            SymbolTableEntry newEntry(VarOffset(offset), entry.value.isConst() ? ReadOnly : 0);
            newEntry.prepareToWatch();
            symbolTable->add(locker, entry.key.get(), newEntry);
            
            ScopeOffset offsetForAssert = globalLexicalEnvironment->addVariables(1, jsTDZValue());
            RELEASE_ASSERT(offsetForAssert == offset);
        }
    }
    return 0;
}