Java Property.NOT_CONFIGURABLE属性代码示例

NativeStrictArguments(final Object[] values, final int numParams,final ScriptObject proto, final PropertyMap map) {
    super(proto, map);
    setIsArguments();

    final ScriptFunction func = Global.instance().getTypeErrorThrower();
    // We have to fill user accessor functions late as these are stored
    // in this object rather than in the PropertyMap of this object.
    final int flags = Property.NOT_ENUMERABLE | Property.NOT_CONFIGURABLE;
    initUserAccessors("caller", flags, func, func);
    initUserAccessors("callee", flags, func, func);

    setArray(ArrayData.allocate(values));
    this.length = values.length;

    // extend/truncate named arg array as needed and copy values
    this.namedArgs = new Object[numParams];
    if (numParams > values.length) {
        Arrays.fill(namedArgs, UNDEFINED);
    }
    System.arraycopy(values, 0, namedArgs, 0, Math.min(namedArgs.length, values.length));
}
 

/**
 * Compute property flags given local state of a field. May be overridden and extended,
 *
 * @param symbol       symbol to check
 * @param hasArguments does the created object have an "arguments" property
 *
 * @return flags to use for fields
 */
protected int getPropertyFlags(final Symbol symbol, final boolean hasArguments) {
    int flags = 0;

    if (symbol.isParam()) {
        flags |= Property.IS_ALWAYS_OBJECT | Property.IS_PARAMETER;
    }

    if (hasArguments) {
        flags |= Property.IS_ALWAYS_OBJECT | Property.HAS_ARGUMENTS;
    }

    if (symbol.isScope()) {
        flags |= Property.NOT_CONFIGURABLE;
    }

    if (symbol.canBePrimitive()) {
        flags |= Property.CAN_BE_PRIMITIVE;
    }

    if (symbol.canBeUndefined()) {
        flags |= Property.CAN_BE_UNDEFINED;
    }

    return flags;
}
 

private static PropertyMap createStrictModeMap(final PropertyMap map) {
    final int flags = Property.NOT_ENUMERABLE | Property.NOT_CONFIGURABLE;
    PropertyMap newMap = map;
    // Need to add properties directly to map since slots are assigned speculatively by newUserAccessors.
    newMap = newMap.addPropertyNoHistory(map.newUserAccessors("arguments", flags));
    newMap = newMap.addPropertyNoHistory(map.newUserAccessors("caller", flags));
    return newMap;
}
 

private ScriptObject createNashornGlobal(final ScriptContext ctxt) {
    final ScriptObject newGlobal = AccessController.doPrivileged(new PrivilegedAction<ScriptObject>() {
        @Override
        public ScriptObject run() {
            try {
                return nashornContext.newGlobal();
            } catch (final RuntimeException e) {
                if (Context.DEBUG) {
                    e.printStackTrace();
                }
                throw e;
            }
        }
    }, CREATE_GLOBAL_ACC_CTXT);

    nashornContext.initGlobal(newGlobal);

    final int NON_ENUMERABLE_CONSTANT = Property.NOT_ENUMERABLE | Property.NOT_CONFIGURABLE | Property.NOT_WRITABLE;
    // current ScriptContext exposed as "context"
    // "context" is non-writable from script - but script engine still
    // needs to set it and so save the context Property object
    contextProperty = newGlobal.addOwnProperty("context", NON_ENUMERABLE_CONSTANT, ctxt);
    // current ScriptEngine instance exposed as "engine". We added @SuppressWarnings("LeakingThisInConstructor") as
    // NetBeans identifies this assignment as such a leak - this is a false positive as we're setting this property
    // in the Global of a Context we just created - both the Context and the Global were just created and can not be
    // seen from another thread outside of this constructor.
    newGlobal.addOwnProperty("engine", NON_ENUMERABLE_CONSTANT, this);
    // global script arguments with undefined value
    newGlobal.addOwnProperty("arguments", Property.NOT_ENUMERABLE, UNDEFINED);
    // file name default is null
    newGlobal.addOwnProperty(ScriptEngine.FILENAME, Property.NOT_ENUMERABLE, null);
    // evaluate engine.js initialization script this new global object
    try {
        evalImpl(compileImpl(ENGINE_SCRIPT_SRC, newGlobal), ctxt, newGlobal);
    } catch (final ScriptException exp) {
        throw new RuntimeException(exp);
    }
    return newGlobal;
}
 

private static PropertyMap createStrictModeMap(final PropertyMap map) {
    final int flags = Property.NOT_ENUMERABLE | Property.NOT_CONFIGURABLE;
    PropertyMap newMap = map;
    // Need to add properties directly to map since slots are assigned speculatively by newUserAccessors.
    newMap = newMap.addProperty(map.newUserAccessors("arguments", flags));
    newMap = newMap.addProperty(map.newUserAccessors("caller", flags));
    return newMap;
}
 

/**
 * Compute property flags given local state of a field. May be overridden and extended,
 *
 * @param symbol       symbol to check
 * @param hasArguments does the created object have an "arguments" property
 *
 * @return flags to use for fields
 */
protected int getPropertyFlags(final Symbol symbol, final boolean hasArguments) {
    int flags = 0;

    if (symbol.isParam()) {
        flags |= Property.IS_ALWAYS_OBJECT | Property.IS_PARAMETER;
    }

    if (hasArguments) {
        flags |= Property.IS_ALWAYS_OBJECT | Property.HAS_ARGUMENTS;
    }

    if (symbol.isScope()) {
        flags |= Property.NOT_CONFIGURABLE;
    }

    if (symbol.canBePrimitive()) {
        flags |= Property.CAN_BE_PRIMITIVE;
    }

    if (symbol.canBeUndefined()) {
        flags |= Property.CAN_BE_UNDEFINED;
    }

    if (symbol.isFunctionDeclaration()) {
        flags |= Property.IS_FUNCTION_DECLARATION;
    }

    return flags;
}
 

/**
 * Compute property flags given local state of a field. May be overridden and extended,
 *
 * @param symbol       symbol to check
 * @param hasArguments does the created object have an "arguments" property
 *
 * @return flags to use for fields
 */
static int getPropertyFlags(final Symbol symbol, final boolean hasArguments, final boolean evalCode) {
    int flags = 0;

    if (symbol.isParam()) {
        flags |= Property.IS_PARAMETER;
    }

    if (hasArguments) {
        flags |= Property.HAS_ARGUMENTS;
    }

    // See ECMA 5.1 10.5 Declaration Binding Instantiation.
    // Step 2  If code is eval code, then let configurableBindings
    // be true else let configurableBindings be false.
    // We have to make vars, functions declared in 'eval' code
    // configurable. But vars, functions from any other code is
    // not configurable.
    if (symbol.isScope() && !evalCode) {
        flags |= Property.NOT_CONFIGURABLE;
    }

    if (symbol.isFunctionDeclaration()) {
        flags |= Property.IS_FUNCTION_DECLARATION;
    }

    if (symbol.isConst()) {
        flags |= Property.NOT_WRITABLE;
    }

    if (symbol.isBlockScoped()) {
        flags |= Property.IS_LEXICAL_BINDING;
    }

    // Mark symbol as needing declaration. Access before declaration will throw a ReferenceError.
    if (symbol.isBlockScoped() && symbol.isScope()) {
        flags |= Property.NEEDS_DECLARATION;
    }

    return flags;
}
 

/**
 * Compute property flags given local state of a field. May be overridden and extended,
 *
 * @param symbol       symbol to check
 * @param hasArguments does the created object have an "arguments" property
 *
 * @return flags to use for fields
 */
static int getPropertyFlags(final Symbol symbol, final boolean hasArguments, final boolean evalCode, final boolean dualFields) {
    int flags = 0;

    if (symbol.isParam()) {
        flags |= Property.IS_PARAMETER;
    }

    if (hasArguments) {
        flags |= Property.HAS_ARGUMENTS;
    }

    // See ECMA 5.1 10.5 Declaration Binding Instantiation.
    // Step 2  If code is eval code, then let configurableBindings
    // be true else let configurableBindings be false.
    // We have to make vars, functions declared in 'eval' code
    // configurable. But vars, functions from any other code is
    // not configurable.
    if (symbol.isScope() && !evalCode) {
        flags |= Property.NOT_CONFIGURABLE;
    }

    if (symbol.isFunctionDeclaration()) {
        flags |= Property.IS_FUNCTION_DECLARATION;
    }

    if (symbol.isConst()) {
        flags |= Property.NOT_WRITABLE;
    }

    if (symbol.isBlockScoped()) {
        flags |= Property.IS_LEXICAL_BINDING;
    }

    // Mark symbol as needing declaration. Access before declaration will throw a ReferenceError.
    if (symbol.isBlockScoped() && symbol.isScope()) {
        flags |= Property.NEEDS_DECLARATION;
    }

    if (dualFields) {
        flags |= Property.DUAL_FIELDS;
    }

    return flags;
}