C++ JSValue::isFunction方法代码示例

RuntimeType TypeSet::getRuntimeTypeForValue(JSValue v)
{
    RuntimeType ret;
    if (v.isFunction())
        ret = TypeFunction;
    else if (v.isUndefined())
        ret = TypeUndefined;
    else if (v.isNull())
        ret = TypeNull;
    else if (v.isBoolean())
        ret = TypeBoolean;
    else if (v.isMachineInt())
        ret = TypeMachineInt;
    else if (v.isNumber())
        ret = TypeNumber;
    else if (v.isString())
        ret = TypeString;
    else if (v.isPrimitive())
        ret = TypePrimitive;
    else if (v.isObject())
        ret = TypeObject;
    else
        CRASH();

    return ret;
}

RuntimeType runtimeTypeForValue(JSValue value)
{
    if (UNLIKELY(!value))
        return TypeNothing;

    if (value.isUndefined())
        return TypeUndefined;
    if (value.isNull())
        return TypeNull;
    if (value.isAnyInt())
        return TypeAnyInt;
    if (value.isNumber())
        return TypeNumber;
    if (value.isString())
        return TypeString;
    if (value.isBoolean())
        return TypeBoolean;
    if (value.isObject())
        return TypeObject;
    if (value.isFunction())
        return TypeFunction;
    if (value.isSymbol())
        return TypeSymbol;

    return TypeNothing;
}

static JSObject* getCustomElementCallback(ExecState& state, JSObject& prototype, const Identifier& id)
{
    JSValue callback = prototype.get(&state, id);
    if (state.hadException())
        return nullptr;
    if (callback.isUndefined())
        return nullptr;
    if (!callback.isFunction()) {
        throwTypeError(&state, ASCIILiteral("A custom element callback must be a function"));
        return nullptr;
    }
    return callback.getObject();
}

JSValue JSWorkerGlobalScope::queueMicrotask(ExecState& state)
{
    VM& vm = state.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    if (UNLIKELY(state.argumentCount() < 1))
        return throwException(&state, scope, createNotEnoughArgumentsError(&state));

    JSValue functionValue = state.uncheckedArgument(0);
    if (UNLIKELY(!functionValue.isFunction(vm)))
        return JSValue::decode(throwArgumentMustBeFunctionError(state, scope, 0, "callback", "WorkerGlobalScope", "queueMicrotask"));

    scope.release();
    Base::queueMicrotask(JSC::createJSMicrotask(vm, functionValue));
    return jsUndefined();
}

JSPromise* ReadableJSStream::invoke(ExecState& state, const char* propertyName, JSValue parameter)
{
    JSValue function = getPropertyFromObject(state, *m_source.get(), propertyName);
    if (state.hadException())
        return nullptr;

    if (!function.isFunction()) {
        if (!function.isUndefined())
            throwVMError(&state, createTypeError(&state, ASCIILiteral("ReadableStream trying to call a property that is not callable")));
        return nullptr;
    }

    MarkedArgumentBuffer arguments;
    arguments.append(parameter);

    JSPromise* promise = jsDynamicCast<JSPromise*>(callFunction(state, function, m_source.get(), arguments));

    ASSERT(!(promise && state.hadException()));
    return promise;
}

void WASMModuleParser::parseFunctionImportSection(ExecState* exec)
{
    uint32_t numberOfFunctionImports;
    uint32_t numberOfFunctionImportSignatures;
    READ_COMPACT_UINT32_OR_FAIL(numberOfFunctionImports, "Cannot read the number of function imports.");
    READ_COMPACT_UINT32_OR_FAIL(numberOfFunctionImportSignatures, "Cannot read the number of function import signatures.");
    m_module->functionImports().reserveInitialCapacity(numberOfFunctionImports);
    m_module->functionImportSignatures().reserveInitialCapacity(numberOfFunctionImportSignatures);
    m_module->importedFunctions().reserveInitialCapacity(numberOfFunctionImports);

    for (uint32_t functionImportIndex = 0; functionImportIndex < numberOfFunctionImports; ++functionImportIndex) {
        WASMFunctionImport functionImport;
        READ_STRING_OR_FAIL(functionImport.functionName, "Cannot read the function import name.");
        m_module->functionImports().uncheckedAppend(functionImport);

        uint32_t numberOfSignatures;
        READ_COMPACT_UINT32_OR_FAIL(numberOfSignatures, "Cannot read the number of signatures.");
        FAIL_IF_FALSE(numberOfSignatures <= numberOfFunctionImportSignatures - m_module->functionImportSignatures().size(), "The number of signatures is incorrect.");

        for (uint32_t i = 0; i < numberOfSignatures; ++i) {
            WASMFunctionImportSignature functionImportSignature;
            READ_COMPACT_UINT32_OR_FAIL(functionImportSignature.signatureIndex, "Cannot read the signature index.");
            FAIL_IF_FALSE(functionImportSignature.signatureIndex < m_module->signatures().size(), "The signature index is incorrect.");
            functionImportSignature.functionImportIndex = functionImportIndex;
            m_module->functionImportSignatures().uncheckedAppend(functionImportSignature);
        }

        JSValue value;
        getImportedValue(exec, functionImport.functionName, value);
        PROPAGATE_ERROR();
        FAIL_IF_FALSE(value.isFunction(), "\"" + functionImport.functionName + "\" is not a function.");
        JSFunction* function = jsCast<JSFunction*>(value.asCell());
        m_module->importedFunctions().uncheckedAppend(WriteBarrier<JSFunction>(m_vm, m_module.get(), function));
    }
    FAIL_IF_FALSE(m_module->functionImportSignatures().size() == numberOfFunctionImportSignatures, "The number of function import signatures is incorrect.");
}

static EncodedJSValue JSC_HOST_CALL constructJSWebAssemblyInstance(ExecState* exec)
{
    auto& vm = exec->vm();
    auto throwScope = DECLARE_THROW_SCOPE(vm);
    auto* globalObject = exec->lexicalGlobalObject();

    // If moduleObject is not a WebAssembly.Module instance, a TypeError is thrown.
    JSWebAssemblyModule* jsModule = jsDynamicCast<JSWebAssemblyModule*>(vm, exec->argument(0));
    if (!jsModule)
        return JSValue::encode(throwException(exec, throwScope, createTypeError(exec, ASCIILiteral("first argument to WebAssembly.Instance must be a WebAssembly.Module"), defaultSourceAppender, runtimeTypeForValue(exec->argument(0)))));
    const Wasm::ModuleInformation& moduleInformation = jsModule->moduleInformation();

    // If the importObject parameter is not undefined and Type(importObject) is not Object, a TypeError is thrown.
    JSValue importArgument = exec->argument(1);
    JSObject* importObject = importArgument.getObject();
    if (!importArgument.isUndefined() && !importObject)
        return JSValue::encode(throwException(exec, throwScope, createTypeError(exec, ASCIILiteral("second argument to WebAssembly.Instance must be undefined or an Object"), defaultSourceAppender, runtimeTypeForValue(importArgument))));

    // If the list of module.imports is not empty and Type(importObject) is not Object, a TypeError is thrown.
    if (moduleInformation.imports.size() && !importObject)
        return JSValue::encode(throwException(exec, throwScope, createTypeError(exec, ASCIILiteral("second argument to WebAssembly.Instance must be Object because the WebAssembly.Module has imports"), defaultSourceAppender, runtimeTypeForValue(importArgument))));

    Identifier moduleKey = Identifier::fromUid(PrivateName(PrivateName::Description, "WebAssemblyInstance"));
    WebAssemblyModuleRecord* moduleRecord = WebAssemblyModuleRecord::create(exec, vm, globalObject->webAssemblyModuleRecordStructure(), moduleKey, moduleInformation);
    RETURN_IF_EXCEPTION(throwScope, encodedJSValue());

    Structure* instanceStructure = InternalFunction::createSubclassStructure(exec, exec->newTarget(), globalObject->WebAssemblyInstanceStructure());
    RETURN_IF_EXCEPTION(throwScope, encodedJSValue());

    JSWebAssemblyInstance* instance = JSWebAssemblyInstance::create(vm, instanceStructure, jsModule, moduleRecord->getModuleNamespace(exec));
    RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
    {
        // Always start with a dummy Memory, so that wasm -> wasm thunks avoid checking for a nullptr Memory when trying to set pinned registers.
        Wasm::Memory memory;
        instance->setMemory(vm, JSWebAssemblyMemory::create(vm, exec->lexicalGlobalObject()->WebAssemblyMemoryStructure(), WTFMove(memory)));
    }

    // Let funcs, memories and tables be initially-empty lists of callable JavaScript objects, WebAssembly.Memory objects and WebAssembly.Table objects, respectively.
    // Let imports be an initially-empty list of external values.
    unsigned numImportFunctions = 0;
    unsigned numImportGlobals = 0;

    bool hasMemoryImport = false;
    bool hasTableImport = false;
    // For each import i in module.imports:
    for (auto& import : moduleInformation.imports) {
        // 1. Let o be the resultant value of performing Get(importObject, i.module_name).
        JSValue importModuleValue = importObject->get(exec, import.module);
        RETURN_IF_EXCEPTION(throwScope, encodedJSValue());
        // 2. If Type(o) is not Object, throw a TypeError.
        if (!importModuleValue.isObject())
            return JSValue::encode(throwException(exec, throwScope, createTypeError(exec, ASCIILiteral("import must be an object"), defaultSourceAppender, runtimeTypeForValue(importModuleValue))));

        // 3. Let v be the value of performing Get(o, i.item_name)
        JSObject* object = jsCast<JSObject*>(importModuleValue);
        JSValue value = object->get(exec, import.field);
        RETURN_IF_EXCEPTION(throwScope, encodedJSValue());

        switch (import.kind) {
        case Wasm::ExternalKind::Function: {
            // 4. If i is a function import:
            // i. If IsCallable(v) is false, throw a WebAssembly.LinkError.
            if (!value.isFunction())
                return JSValue::encode(throwException(exec, throwScope, createJSWebAssemblyLinkError(exec, vm, ASCIILiteral("import function must be callable"))));
            JSCell* cell = value.asCell();
            // ii. If v is an Exported Function Exotic Object:
            if (WebAssemblyFunction* importedExport = jsDynamicCast<WebAssemblyFunction*>(vm, cell)) {
                // a. If the signature of v does not match the signature of i, throw a WebAssembly.LinkError.
                Wasm::SignatureIndex importedSignatureIndex = importedExport->signatureIndex();
                Wasm::SignatureIndex expectedSignatureIndex = moduleInformation.importFunctionSignatureIndices[import.kindIndex];
                if (importedSignatureIndex != expectedSignatureIndex)
                    return JSValue::encode(throwException(exec, throwScope, createJSWebAssemblyLinkError(exec, vm, ASCIILiteral("imported function's signature doesn't match the provided WebAssembly function's signature"))));
                // b. Let closure be v.[[Closure]].
            }
            // iii. Otherwise:
            // a. Let closure be a new host function of the given signature which calls v by coercing WebAssembly arguments to JavaScript arguments via ToJSValue and returns the result, if any, by coercing via ToWebAssemblyValue.
            // Note: done as part of Plan compilation.
            // iv. Append v to funcs.
            // Note: adding the JSCell to the instance list fulfills closure requirements b. above (the WebAssembly.Instance wil be kept alive) and v. below (the JSFunction).
            instance->setImportFunction(vm, cell, numImportFunctions++);
            // v. Append closure to imports.
            break;
        }
        case Wasm::ExternalKind::Table: {
            RELEASE_ASSERT(!hasTableImport); // This should be guaranteed by a validation failure.
            // 7. Otherwise (i is a table import):
            hasTableImport = true;
            JSWebAssemblyTable* table = jsDynamicCast<JSWebAssemblyTable*>(vm, value);
            // i. If v is not a WebAssembly.Table object, throw a WebAssembly.LinkError.
            if (!table)
                return JSValue::encode(throwException(exec, throwScope, createJSWebAssemblyLinkError(exec, vm, ASCIILiteral("Table import is not an instance of WebAssembly.Table"))));

            uint32_t expectedInitial = moduleInformation.tableInformation.initial();
            uint32_t actualInitial = table->size();
            if (actualInitial < expectedInitial)
                return JSValue::encode(throwException(exec, throwScope, createJSWebAssemblyLinkError(exec, vm, ASCIILiteral("Table import provided an 'initial' that is too small"))));

            if (std::optional<uint32_t> expectedMaximum = moduleInformation.tableInformation.maximum()) {
                std::optional<uint32_t> actualMaximum = table->maximum();
                if (!actualMaximum) {
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