PrimitiveLookup.java revision 1015:8a4af0397070
1/* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package jdk.nashorn.internal.runtime.linker; 27 28import static jdk.nashorn.internal.lookup.Lookup.MH; 29 30import java.lang.invoke.MethodHandle; 31import java.lang.invoke.MethodType; 32import jdk.internal.dynalink.CallSiteDescriptor; 33import jdk.internal.dynalink.linker.GuardedInvocation; 34import jdk.internal.dynalink.linker.LinkRequest; 35import jdk.internal.dynalink.support.Guards; 36import jdk.nashorn.internal.runtime.FindProperty; 37import jdk.nashorn.internal.runtime.ScriptObject; 38import jdk.nashorn.internal.runtime.UserAccessorProperty; 39 40/** 41 * Implements lookup of methods to link for dynamic operations on JavaScript primitive values (booleans, strings, and 42 * numbers). This class is only public so it can be accessed by classes in the {@code jdk.nashorn.internal.objects} 43 * package. 44 */ 45public final class PrimitiveLookup { 46 47 private PrimitiveLookup() { 48 } 49 50 /** 51 * Returns a guarded invocation representing the linkage for a dynamic operation on a primitive Java value. 52 * @param request the link request for the dynamic call site. 53 * @param receiverClass the class of the receiver value (e.g., {@link java.lang.Boolean}, {@link java.lang.String} etc.) 54 * @param wrappedReceiver a transient JavaScript native wrapper object created as the object proxy for the primitive 55 * value; see ECMAScript 5.1, section 8.7.1 for discussion of using {@code [[Get]]} on a property reference with a 56 * primitive base value. This instance will be used to delegate actual lookup. 57 * @param wrapFilter A method handle that takes a primitive value of type specified in the {@code receiverClass} and 58 * creates a transient native wrapper of the same type as {@code wrappedReceiver} for subsequent invocations of the 59 * method - it will be combined into the returned invocation as an argument filter on the receiver. 60 * @return a guarded invocation representing the operation at the call site when performed on a JavaScript primitive 61 * @param protoFilter A method handle that walks up the proto chain of this receiver object 62 * type {@code receiverClass}. 63 */ 64 public static GuardedInvocation lookupPrimitive(final LinkRequest request, final Class<?> receiverClass, 65 final ScriptObject wrappedReceiver, final MethodHandle wrapFilter, 66 final MethodHandle protoFilter) { 67 return lookupPrimitive(request, Guards.getInstanceOfGuard(receiverClass), wrappedReceiver, wrapFilter, protoFilter); 68 } 69 70 /** 71 * Returns a guarded invocation representing the linkage for a dynamic operation on a primitive Java value. 72 * @param request the link request for the dynamic call site. 73 * @param guard an explicit guard that will be used for the returned guarded invocation. 74 * @param wrappedReceiver a transient JavaScript native wrapper object created as the object proxy for the primitive 75 * value; see ECMAScript 5.1, section 8.7.1 for discussion of using {@code [[Get]]} on a property reference with a 76 * primitive base value. This instance will be used to delegate actual lookup. 77 * @param wrapFilter A method handle that takes a primitive value of type guarded by the {@code guard} and 78 * creates a transient native wrapper of the same type as {@code wrappedReceiver} for subsequent invocations of the 79 * method - it will be combined into the returned invocation as an argument filter on the receiver. 80 * @param protoFilter A method handle that walks up the proto chain of this receiver object 81 * @return a guarded invocation representing the operation at the call site when performed on a JavaScript primitive 82 * type (that is implied by both {@code guard} and {@code wrappedReceiver}). 83 */ 84 public static GuardedInvocation lookupPrimitive(final LinkRequest request, final MethodHandle guard, 85 final ScriptObject wrappedReceiver, final MethodHandle wrapFilter, 86 final MethodHandle protoFilter) { 87 final CallSiteDescriptor desc = request.getCallSiteDescriptor(); 88 89 if(desc.getNameTokenCount() > 2) { 90 final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND); 91 final FindProperty find = wrappedReceiver.findProperty(name, true); 92 if(find == null) { 93 // Give up early, give chance to BeanLinker and NashornBottomLinker to deal with it. 94 return null; 95 } else if (find.isInherited() && !(find.getProperty() instanceof UserAccessorProperty)) { 96 // If property is found in the prototype object bind the method handle directly to 97 // the proto filter instead of going through wrapper instantiation below. 98 final ScriptObject proto = wrappedReceiver.getProto(); 99 final GuardedInvocation link = proto.lookup(desc, request); 100 101 if (link != null) { 102 final MethodHandle invocation = link.getInvocation(); 103 final MethodHandle adaptedInvocation = MH.asType(invocation, invocation.type().changeParameterType(0, Object.class)); 104 final MethodHandle method = MH.filterArguments(adaptedInvocation, 0, protoFilter); 105 final MethodHandle protoGuard = MH.filterArguments(link.getGuard(), 0, protoFilter); 106 return new GuardedInvocation(method, NashornGuards.combineGuards(guard, protoGuard)); 107 } 108 } 109 } 110 final GuardedInvocation link = wrappedReceiver.lookup(desc, request); 111 if (link != null) { 112 MethodHandle method = link.getInvocation(); 113 final Class<?> receiverType = method.type().parameterType(0); 114 if (receiverType != Object.class) { 115 final MethodType wrapType = wrapFilter.type(); 116 assert receiverType.isAssignableFrom(wrapType.returnType()); 117 method = MH.filterArguments(method, 0, MH.asType(wrapFilter, wrapType.changeReturnType(receiverType))); 118 } 119 return new GuardedInvocation(method, guard, link.getSwitchPoints(), null); 120 } 121 return null; 122 } 123} 124