--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/linker/support/Guards.java Wed Jul 05 21:04:26 2017 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,338 +0,0 @@
-/*
- * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-/*
- * This file is available under and governed by the GNU General Public
- * License version 2 only, as published by the Free Software Foundation.
- * However, the following notice accompanied the original version of this
- * file, and Oracle licenses the original version of this file under the BSD
- * license:
- */
-/*
- Copyright 2009-2013 Attila Szegedi
-
- Licensed under both the Apache License, Version 2.0 (the "Apache License")
- and the BSD License (the "BSD License"), with licensee being free to
- choose either of the two at their discretion.
-
- You may not use this file except in compliance with either the Apache
- License or the BSD License.
-
- If you choose to use this file in compliance with the Apache License, the
- following notice applies to you:
-
- You may obtain a copy of the Apache License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
- implied. See the License for the specific language governing
- permissions and limitations under the License.
-
- If you choose to use this file in compliance with the BSD License, the
- following notice applies to you:
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are
- met:
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * 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.
- * Neither the name of the copyright holder nor the names of
- contributors may be used to endorse or promote products derived from
- this software without specific prior written permission.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
- IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
- PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
- BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
- BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-*/
-
-package jdk.internal.dynalink.linker.support;
-
-import java.lang.invoke.MethodHandle;
-import java.lang.invoke.MethodHandles;
-import java.lang.invoke.MethodType;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import jdk.internal.dynalink.DynamicLinker;
-import jdk.internal.dynalink.linker.LinkerServices;
-
-/**
- * Utility methods for creating typical guards for
- * {@link MethodHandles#guardWithTest(MethodHandle, MethodHandle, MethodHandle)}
- * and for adjusting their method types.
- */
-public final class Guards {
- private static final Logger LOG = Logger
- .getLogger(Guards.class.getName(), "jdk.internal.dynalink.support.messages");
-
- private Guards() {
- }
-
- /**
- * Creates a guard method handle with arguments of a specified type, but with boolean return value. When invoked, it
- * returns true if the first argument is of the specified class (exactly of it, not a subclass). The rest of the
- * arguments will be ignored.
- *
- * @param clazz the class of the first argument to test for
- * @param type the method type
- * @return a method handle testing whether its first argument is of the specified class.
- */
- @SuppressWarnings("boxing")
- public static MethodHandle isOfClass(final Class<?> clazz, final MethodType type) {
- final Class<?> declaredType = type.parameterType(0);
- if(clazz == declaredType) {
- LOG.log(Level.WARNING, "isOfClassGuardAlwaysTrue", new Object[] { clazz.getName(), 0, type, DynamicLinker.getLinkedCallSiteLocation() });
- return constantTrue(type);
- }
- if(!declaredType.isAssignableFrom(clazz)) {
- LOG.log(Level.WARNING, "isOfClassGuardAlwaysFalse", new Object[] { clazz.getName(), 0, type, DynamicLinker.getLinkedCallSiteLocation() });
- return constantFalse(type);
- }
- return getClassBoundArgumentTest(IS_OF_CLASS, clazz, 0, type);
- }
-
- /**
- * Creates a method handle with arguments of a specified type, but with boolean return value. When invoked, it
- * returns true if the first argument is instance of the specified class or its subclass). The rest of the arguments
- * will be ignored.
- *
- * @param clazz the class of the first argument to test for
- * @param type the method type
- * @return a method handle testing whether its first argument is of the specified class or subclass.
- */
- public static MethodHandle isInstance(final Class<?> clazz, final MethodType type) {
- return isInstance(clazz, 0, type);
- }
-
- /**
- * Creates a method handle with arguments of a specified type, but with boolean return value. When invoked, it
- * returns true if the n'th argument is instance of the specified class or its subclass). The rest of the arguments
- * will be ignored.
- *
- * @param clazz the class of the first argument to test for
- * @param pos the position on the argument list to test
- * @param type the method type
- * @return a method handle testing whether its first argument is of the specified class or subclass.
- */
- @SuppressWarnings("boxing")
- public static MethodHandle isInstance(final Class<?> clazz, final int pos, final MethodType type) {
- final Class<?> declaredType = type.parameterType(pos);
- if(clazz.isAssignableFrom(declaredType)) {
- LOG.log(Level.WARNING, "isInstanceGuardAlwaysTrue", new Object[] { clazz.getName(), pos, type, DynamicLinker.getLinkedCallSiteLocation() });
- return constantTrue(type);
- }
- if(!declaredType.isAssignableFrom(clazz)) {
- LOG.log(Level.WARNING, "isInstanceGuardAlwaysFalse", new Object[] { clazz.getName(), pos, type, DynamicLinker.getLinkedCallSiteLocation() });
- return constantFalse(type);
- }
- return getClassBoundArgumentTest(IS_INSTANCE, clazz, pos, type);
- }
-
- /**
- * Creates a method handle that returns true if the argument in the specified position is a Java array.
- *
- * @param pos the position in the argument lit
- * @param type the method type of the handle
- * @return a method handle that returns true if the argument in the specified position is a Java array; the rest of
- * the arguments are ignored.
- */
- @SuppressWarnings("boxing")
- public static MethodHandle isArray(final int pos, final MethodType type) {
- final Class<?> declaredType = type.parameterType(pos);
- if(declaredType.isArray()) {
- LOG.log(Level.WARNING, "isArrayGuardAlwaysTrue", new Object[] { pos, type, DynamicLinker.getLinkedCallSiteLocation() });
- return constantTrue(type);
- }
- if(!declaredType.isAssignableFrom(Object[].class)) {
- LOG.log(Level.WARNING, "isArrayGuardAlwaysFalse", new Object[] { pos, type, DynamicLinker.getLinkedCallSiteLocation() });
- return constantFalse(type);
- }
- return asType(IS_ARRAY, pos, type);
- }
-
- private static MethodHandle getClassBoundArgumentTest(final MethodHandle test, final Class<?> clazz, final int pos, final MethodType type) {
- // Bind the class to the first argument of the test
- return asType(test.bindTo(clazz), pos, type);
- }
-
- /**
- * Takes a method handle intended to be used as a guard, and adapts it to
- * the requested type, but returning a boolean. Applies
- * {@link MethodHandle#asType(MethodType)} to convert types and uses
- * {@link MethodHandles#dropArguments(MethodHandle, int, Class...)} to match
- * the requested type arity.
- * @param test the test method handle
- * @param type the type to adapt the method handle to
- * @return the adapted method handle
- */
- public static MethodHandle asType(final MethodHandle test, final MethodType type) {
- return test.asType(getTestType(test, type));
- }
-
- /**
- * Takes a method handle intended to be used as a guard, and adapts it to
- * the requested type, but returning a boolean. Applies
- * {@link LinkerServices#asType(MethodHandle, MethodType)} to convert types
- * and uses
- * {@link MethodHandles#dropArguments(MethodHandle, int, Class...)} to match
- * the requested type arity.
- * @param linkerServices the linker services to use for type conversions
- * @param test the test method handle
- * @param type the type to adapt the method handle to
- * @return the adapted method handle
- */
- public static MethodHandle asType(final LinkerServices linkerServices, final MethodHandle test, final MethodType type) {
- return linkerServices.asType(test, getTestType(test, type));
- }
-
- private static MethodType getTestType(final MethodHandle test, final MethodType type) {
- return type.dropParameterTypes(test.type().parameterCount(),
- type.parameterCount()).changeReturnType(boolean.class);
- }
-
- private static MethodHandle asType(final MethodHandle test, final int pos, final MethodType type) {
- assert test != null;
- assert type != null;
- assert type.parameterCount() > 0;
- assert pos >= 0 && pos < type.parameterCount();
- assert test.type().parameterCount() == 1;
- assert test.type().returnType() == Boolean.TYPE;
- return MethodHandles.permuteArguments(test.asType(test.type().changeParameterType(0, type.parameterType(pos))),
- type.changeReturnType(Boolean.TYPE), new int[] { pos });
- }
-
- private static final MethodHandle IS_INSTANCE = Lookup.PUBLIC.findVirtual(Class.class, "isInstance",
- MethodType.methodType(Boolean.TYPE, Object.class));
-
- private static final MethodHandle IS_OF_CLASS;
- private static final MethodHandle IS_ARRAY;
- private static final MethodHandle IS_IDENTICAL;
- private static final MethodHandle IS_NULL;
- private static final MethodHandle IS_NOT_NULL;
-
- static {
- final Lookup lookup = new Lookup(MethodHandles.lookup());
-
- IS_OF_CLASS = lookup.findOwnStatic("isOfClass", Boolean.TYPE, Class.class, Object.class);
- IS_ARRAY = lookup.findOwnStatic("isArray", Boolean.TYPE, Object.class);
- IS_IDENTICAL = lookup.findOwnStatic("isIdentical", Boolean.TYPE, Object.class, Object.class);
- IS_NULL = lookup.findOwnStatic("isNull", Boolean.TYPE, Object.class);
- IS_NOT_NULL = lookup.findOwnStatic("isNotNull", Boolean.TYPE, Object.class);
- }
-
- /**
- * Creates a guard method that tests its only argument for being of an exact particular class.
- * @param clazz the class to test for.
- * @return the desired guard method.
- */
- public static MethodHandle getClassGuard(final Class<?> clazz) {
- return IS_OF_CLASS.bindTo(clazz);
- }
-
- /**
- * Creates a guard method that tests its only argument for being an instance of a particular class.
- * @param clazz the class to test for.
- * @return the desired guard method.
- */
- public static MethodHandle getInstanceOfGuard(final Class<?> clazz) {
- return IS_INSTANCE.bindTo(clazz);
- }
-
- /**
- * Creates a guard method that tests its only argument for being referentially identical to another object
- * @param obj the object used as referential identity test
- * @return the desired guard method.
- */
- public static MethodHandle getIdentityGuard(final Object obj) {
- return IS_IDENTICAL.bindTo(obj);
- }
-
- /**
- * Returns a guard that tests whether the first argument is null.
- * @return a guard that tests whether the first argument is null.
- */
- public static MethodHandle isNull() {
- return IS_NULL;
- }
-
- /**
- * Returns a guard that tests whether the first argument is not null.
- * @return a guard that tests whether the first argument is not null.
- */
- public static MethodHandle isNotNull() {
- return IS_NOT_NULL;
- }
-
- @SuppressWarnings("unused")
- private static boolean isNull(final Object obj) {
- return obj == null;
- }
-
- @SuppressWarnings("unused")
- private static boolean isNotNull(final Object obj) {
- return obj != null;
- }
-
- @SuppressWarnings("unused")
- private static boolean isArray(final Object o) {
- return o != null && o.getClass().isArray();
- }
-
- @SuppressWarnings("unused")
- private static boolean isOfClass(final Class<?> c, final Object o) {
- return o != null && o.getClass() == c;
- }
-
- @SuppressWarnings("unused")
- private static boolean isIdentical(final Object o1, final Object o2) {
- return o1 == o2;
- }
-
- private static MethodHandle constantTrue(final MethodType type) {
- return constantBoolean(Boolean.TRUE, type);
- }
-
- private static MethodHandle constantFalse(final MethodType type) {
- return constantBoolean(Boolean.FALSE, type);
- }
-
- private static MethodHandle constantBoolean(final Boolean value, final MethodType type) {
- return MethodHandles.permuteArguments(MethodHandles.constant(Boolean.TYPE, value),
- type.changeReturnType(Boolean.TYPE));
- }
-}