--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/beans/SingleDynamicMethod.java Wed Jul 05 21:04:26 2017 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,312 +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.beans;
-
-import java.lang.invoke.MethodHandle;
-import java.lang.invoke.MethodHandles;
-import java.lang.invoke.MethodType;
-import java.lang.reflect.Array;
-import java.util.StringTokenizer;
-import jdk.internal.dynalink.CallSiteDescriptor;
-import jdk.internal.dynalink.linker.LinkerServices;
-import jdk.internal.dynalink.linker.support.Guards;
-import jdk.internal.dynalink.linker.support.Lookup;
-
-/**
- * Base class for dynamic methods that dispatch to a single target Java method or constructor. Handles adaptation of the
- * target method to a call site type (including mapping variable arity methods to a call site signature with different
- * arity).
- */
-abstract class SingleDynamicMethod extends DynamicMethod {
-
- private static final MethodHandle CAN_CONVERT_TO = Lookup.findOwnStatic(MethodHandles.lookup(), "canConvertTo", boolean.class, LinkerServices.class, Class.class, Object.class);
-
- SingleDynamicMethod(final String name) {
- super(name);
- }
-
- /**
- * Returns true if this method is variable arity.
- * @return true if this method is variable arity.
- */
- abstract boolean isVarArgs();
-
- /**
- * Returns this method's native type.
- * @return this method's native type.
- */
- abstract MethodType getMethodType();
-
- /**
- * Given a specified call site descriptor, returns a method handle to this method's target. The target
- * should only depend on the descriptor's lookup, and it should only retrieve it (as a privileged
- * operation) when it is absolutely needed.
- * @param desc the call site descriptor to use.
- * @return the handle to this method's target method.
- */
- abstract MethodHandle getTarget(CallSiteDescriptor desc);
-
- @Override
- MethodHandle getInvocation(final CallSiteDescriptor callSiteDescriptor, final LinkerServices linkerServices) {
- return getInvocation(getTarget(callSiteDescriptor), callSiteDescriptor.getMethodType(),
- linkerServices);
- }
-
- @Override
- SingleDynamicMethod getMethodForExactParamTypes(final String paramTypes) {
- return typeMatchesDescription(paramTypes, getMethodType()) ? this : null;
- }
-
- @Override
- boolean contains(final SingleDynamicMethod method) {
- return getMethodType().parameterList().equals(method.getMethodType().parameterList());
- }
-
- static String getMethodNameWithSignature(final MethodType type, final String methodName, final boolean withReturnType) {
- final String typeStr = type.toString();
- final int retTypeIndex = typeStr.lastIndexOf(')') + 1;
- int secondParamIndex = typeStr.indexOf(',') + 1;
- if(secondParamIndex == 0) {
- secondParamIndex = retTypeIndex - 1;
- }
- final StringBuilder b = new StringBuilder();
- if (withReturnType) {
- b.append(typeStr, retTypeIndex, typeStr.length()).append(' ');
- }
- return b.append(methodName).append('(').append(typeStr, secondParamIndex, retTypeIndex).toString();
- }
-
- /**
- * Given a method handle and a call site type, adapts the method handle to the call site type. Performs type
- * conversions as needed using the specified linker services, and in case that the method handle is a vararg
- * collector, matches it to the arity of the call site. The type of the return value is only changed if it can be
- * converted using a conversion that loses neither precision nor magnitude, see
- * {@link LinkerServices#asTypeLosslessReturn(MethodHandle, MethodType)}.
- * @param target the method handle to adapt
- * @param callSiteType the type of the call site
- * @param linkerServices the linker services used for type conversions
- * @return the adapted method handle.
- */
- static MethodHandle getInvocation(final MethodHandle target, final MethodType callSiteType, final LinkerServices linkerServices) {
- final MethodHandle filteredTarget = linkerServices.filterInternalObjects(target);
- final MethodType methodType = filteredTarget.type();
- final int paramsLen = methodType.parameterCount();
- final boolean varArgs = target.isVarargsCollector();
- final MethodHandle fixTarget = varArgs ? filteredTarget.asFixedArity() : filteredTarget;
- final int fixParamsLen = varArgs ? paramsLen - 1 : paramsLen;
- final int argsLen = callSiteType.parameterCount();
- if(argsLen < fixParamsLen) {
- // Less actual arguments than number of fixed declared arguments; can't invoke.
- return null;
- }
- // Method handle has the same number of fixed arguments as the call site type
- if(argsLen == fixParamsLen) {
- // Method handle that matches the number of actual arguments as the number of fixed arguments
- final MethodHandle matchedMethod;
- if(varArgs) {
- // If vararg, add a zero-length array of the expected type as the last argument to signify no variable
- // arguments.
- matchedMethod = MethodHandles.insertArguments(fixTarget, fixParamsLen, Array.newInstance(
- methodType.parameterType(fixParamsLen).getComponentType(), 0));
- } else {
- // Otherwise, just use the method
- matchedMethod = fixTarget;
- }
- return createConvertingInvocation(matchedMethod, linkerServices, callSiteType);
- }
-
- // What's below only works for varargs
- if(!varArgs) {
- return null;
- }
-
- final Class<?> varArgType = methodType.parameterType(fixParamsLen);
- // Handle a somewhat sinister corner case: caller passes exactly one argument in the vararg position, and we
- // must handle both a prepacked vararg array as well as a genuine 1-long vararg sequence.
- if(argsLen == paramsLen) {
- final Class<?> callSiteLastArgType = callSiteType.parameterType(fixParamsLen);
- if(varArgType.isAssignableFrom(callSiteLastArgType)) {
- // Call site signature guarantees we'll always be passed a single compatible array; just link directly
- // to the method, introducing necessary conversions. Also, preserve it being a variable arity method.
- return createConvertingInvocation(filteredTarget, linkerServices, callSiteType).asVarargsCollector(
- callSiteLastArgType);
- }
-
- // This method handle takes the single argument and packs it into a newly allocated single-element array. It
- // will be used when the incoming argument can't be converted to the vararg array type (the "vararg packer"
- // method).
- final MethodHandle varArgCollectingInvocation = createConvertingInvocation(collectArguments(fixTarget,
- argsLen), linkerServices, callSiteType);
-
- // Is call site type assignable from an array type (e.g. Object:int[], or Object[]:String[])
- final boolean isAssignableFromArray = callSiteLastArgType.isAssignableFrom(varArgType);
- // Do we have a custom conversion that can potentially convert the call site type to an array?
- final boolean isCustomConvertible = linkerServices.canConvert(callSiteLastArgType, varArgType);
- if(!isAssignableFromArray && !isCustomConvertible) {
- // Call site signature guarantees the argument can definitely not be converted to an array (i.e. it is
- // primitive), and no conversion can help with it either. Link immediately to a vararg-packing method
- // handle.
- return varArgCollectingInvocation;
- }
-
- // This method handle employs language-specific conversions to convert the last argument into an array of
- // vararg type.
- final MethodHandle arrayConvertingInvocation = createConvertingInvocation(MethodHandles.filterArguments(
- fixTarget, fixParamsLen, linkerServices.getTypeConverter(callSiteLastArgType, varArgType)),
- linkerServices, callSiteType);
-
- // This method handle determines whether the value can be converted to the array of vararg type using a
- // language-specific conversion.
- final MethodHandle canConvertArgToArray = MethodHandles.insertArguments(CAN_CONVERT_TO, 0, linkerServices,
- varArgType);
-
- // This one adjusts the previous one for the location of the argument and the call site type.
- final MethodHandle canConvertLastArgToArray = MethodHandles.dropArguments(canConvertArgToArray, 0,
- MethodType.genericMethodType(fixParamsLen).parameterList()).asType(callSiteType.changeReturnType(boolean.class));
-
- // This one takes the previous ones and combines them into a method handle that converts the argument into
- // a vararg array when it can, otherwise falls back to the vararg packer.
- final MethodHandle convertToArrayWhenPossible = MethodHandles.guardWithTest(canConvertLastArgToArray,
- arrayConvertingInvocation, varArgCollectingInvocation);
-
- if(isAssignableFromArray) {
- return MethodHandles.guardWithTest(
- // Is incoming parameter already a compatible array?
- Guards.isInstance(varArgType, fixParamsLen, callSiteType),
- // Yes: just pass it to the method
- createConvertingInvocation(fixTarget, linkerServices, callSiteType),
- // No: either go through a custom conversion, or if it is not possible, go directly to the
- // vararg packer.
- isCustomConvertible ? convertToArrayWhenPossible : varArgCollectingInvocation);
- }
-
- // Just do the custom conversion with fallback to the vararg packer logic.
- assert isCustomConvertible;
- return convertToArrayWhenPossible;
- }
-
- // Remaining case: more than one vararg.
- return createConvertingInvocation(collectArguments(fixTarget, argsLen), linkerServices, callSiteType);
- }
-
- @SuppressWarnings("unused")
- private static boolean canConvertTo(final LinkerServices linkerServices, final Class<?> to, final Object obj) {
- return obj == null ? false : linkerServices.canConvert(obj.getClass(), to);
- }
-
- /**
- * Creates a method handle out of the original target that will collect the varargs for the exact component type of
- * the varArg array. Note that this will nicely trigger language-specific type converters for exactly those varargs
- * for which it is necessary when later passed to linkerServices.convertArguments().
- *
- * @param target the original method handle
- * @param parameterCount the total number of arguments in the new method handle
- * @return a collecting method handle
- */
- static MethodHandle collectArguments(final MethodHandle target, final int parameterCount) {
- final MethodType methodType = target.type();
- final int fixParamsLen = methodType.parameterCount() - 1;
- final Class<?> arrayType = methodType.parameterType(fixParamsLen);
- return target.asCollector(arrayType, parameterCount - fixParamsLen);
- }
-
- private static MethodHandle createConvertingInvocation(final MethodHandle sizedMethod,
- final LinkerServices linkerServices, final MethodType callSiteType) {
- return linkerServices.asTypeLosslessReturn(sizedMethod, callSiteType);
- }
-
- private static boolean typeMatchesDescription(final String paramTypes, final MethodType type) {
- final StringTokenizer tok = new StringTokenizer(paramTypes, ", ");
- for(int i = 1; i < type.parameterCount(); ++i) { // i = 1 as we ignore the receiver
- if(!(tok.hasMoreTokens() && typeNameMatches(tok.nextToken(), type.parameterType(i)))) {
- return false;
- }
- }
- return !tok.hasMoreTokens();
- }
-
- private static boolean typeNameMatches(final String typeName, final Class<?> type) {
- return typeName.equals(typeName.indexOf('.') == -1 ? type.getSimpleName() : type.getCanonicalName());
- }
-}