NashornBottomLinker.java revision 1265:6af2ee7b09a9
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; 29import static jdk.nashorn.internal.runtime.ECMAErrors.typeError; 30import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED; 31 32import java.lang.invoke.MethodHandle; 33import java.util.HashMap; 34import java.util.Map; 35import jdk.internal.dynalink.CallSiteDescriptor; 36import jdk.internal.dynalink.beans.BeansLinker; 37import jdk.internal.dynalink.linker.GuardedInvocation; 38import jdk.internal.dynalink.linker.GuardedTypeConversion; 39import jdk.internal.dynalink.linker.GuardingDynamicLinker; 40import jdk.internal.dynalink.linker.GuardingTypeConverterFactory; 41import jdk.internal.dynalink.linker.LinkRequest; 42import jdk.internal.dynalink.linker.LinkerServices; 43import jdk.internal.dynalink.support.Guards; 44import jdk.nashorn.internal.codegen.types.Type; 45import jdk.nashorn.internal.runtime.JSType; 46import jdk.nashorn.internal.runtime.ScriptRuntime; 47import jdk.nashorn.internal.runtime.UnwarrantedOptimismException; 48 49/** 50 * Nashorn bottom linker; used as a last-resort catch-all linker for all linking requests that fall through all other 51 * linkers (see how {@link Bootstrap} class configures the dynamic linker in its static initializer). It will throw 52 * appropriate ECMAScript errors for attempts to invoke operations on {@code null}, link no-op property getters and 53 * setters for Java objects that couldn't be linked by any other linker, and throw appropriate ECMAScript errors for 54 * attempts to invoke arbitrary Java objects as functions or constructors. 55 */ 56final class NashornBottomLinker implements GuardingDynamicLinker, GuardingTypeConverterFactory { 57 58 @Override 59 public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) 60 throws Exception { 61 final Object self = linkRequest.getReceiver(); 62 63 if (self == null) { 64 return linkNull(linkRequest); 65 } 66 67 // None of the objects that can be linked by NashornLinker should ever reach here. Basically, anything below 68 // this point is a generic Java bean. Therefore, reaching here with a ScriptObject is a Nashorn bug. 69 assert isExpectedObject(self) : "Couldn't link " + linkRequest.getCallSiteDescriptor() + " for " + self.getClass().getName(); 70 71 return linkBean(linkRequest, linkerServices); 72 } 73 74 private static final MethodHandle EMPTY_PROP_GETTER = 75 MH.dropArguments(MH.constant(Object.class, UNDEFINED), 0, Object.class); 76 private static final MethodHandle EMPTY_ELEM_GETTER = 77 MH.dropArguments(EMPTY_PROP_GETTER, 0, Object.class); 78 private static final MethodHandle EMPTY_PROP_SETTER = 79 MH.asType(EMPTY_ELEM_GETTER, EMPTY_ELEM_GETTER.type().changeReturnType(void.class)); 80 private static final MethodHandle EMPTY_ELEM_SETTER = 81 MH.dropArguments(EMPTY_PROP_SETTER, 0, Object.class); 82 83 private static GuardedInvocation linkBean(final LinkRequest linkRequest, final LinkerServices linkerServices) throws Exception { 84 final NashornCallSiteDescriptor desc = (NashornCallSiteDescriptor)linkRequest.getCallSiteDescriptor(); 85 final Object self = linkRequest.getReceiver(); 86 final String operator = desc.getFirstOperator(); 87 switch (operator) { 88 case "new": 89 if(BeansLinker.isDynamicConstructor(self)) { 90 throw typeError("no.constructor.matches.args", ScriptRuntime.safeToString(self)); 91 } 92 if(BeansLinker.isDynamicMethod(self)) { 93 throw typeError("method.not.constructor", ScriptRuntime.safeToString(self)); 94 } 95 throw typeError("not.a.function", ScriptRuntime.safeToString(self)); 96 case "call": 97 if(BeansLinker.isDynamicConstructor(self)) { 98 throw typeError("constructor.requires.new", ScriptRuntime.safeToString(self)); 99 } 100 if(BeansLinker.isDynamicMethod(self)) { 101 throw typeError("no.method.matches.args", ScriptRuntime.safeToString(self)); 102 } 103 throw typeError("not.a.function", ScriptRuntime.safeToString(self)); 104 case "callMethod": 105 case "getMethod": 106 throw typeError("no.such.function", getArgument(linkRequest), ScriptRuntime.safeToString(self)); 107 case "getProp": 108 case "getElem": 109 if(NashornCallSiteDescriptor.isOptimistic(desc)) { 110 throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT); 111 } 112 if (desc.getOperand() != null) { 113 return getInvocation(EMPTY_PROP_GETTER, self, linkerServices, desc); 114 } 115 return getInvocation(EMPTY_ELEM_GETTER, self, linkerServices, desc); 116 case "setProp": 117 case "setElem": { 118 final boolean strict = NashornCallSiteDescriptor.isStrict(desc); 119 if (strict) { 120 throw typeError("cant.set.property", getArgument(linkRequest), ScriptRuntime.safeToString(self)); 121 } 122 if (desc.getOperand() != null) { 123 return getInvocation(EMPTY_PROP_SETTER, self, linkerServices, desc); 124 } 125 return getInvocation(EMPTY_ELEM_SETTER, self, linkerServices, desc); 126 } 127 default: 128 break; 129 } 130 throw new AssertionError("unknown call type " + desc); 131 } 132 133 @Override 134 public GuardedTypeConversion convertToType(final Class<?> sourceType, final Class<?> targetType) throws Exception { 135 final GuardedInvocation gi = convertToTypeNoCast(sourceType, targetType); 136 return gi == null ? null : new GuardedTypeConversion(gi.asType(MH.type(targetType, sourceType)), true); 137 } 138 139 /** 140 * Main part of the implementation of {@link GuardingTypeConverterFactory#convertToType(Class, Class)} that doesn't 141 * care about adapting the method signature; that's done by the invoking method. Returns conversion from Object to String/number/boolean (JS primitive types). 142 * @param sourceType the source type 143 * @param targetType the target type 144 * @return a guarded invocation that converts from the source type to the target type. 145 * @throws Exception if something goes wrong 146 */ 147 private static GuardedInvocation convertToTypeNoCast(final Class<?> sourceType, final Class<?> targetType) throws Exception { 148 final MethodHandle mh = CONVERTERS.get(targetType); 149 if (mh != null) { 150 return new GuardedInvocation(mh); 151 } 152 153 return null; 154 } 155 156 private static GuardedInvocation getInvocation(final MethodHandle handle, final Object self, final LinkerServices linkerServices, final CallSiteDescriptor desc) { 157 return Bootstrap.asTypeSafeReturn(new GuardedInvocation(handle, Guards.getClassGuard(self.getClass())), linkerServices, desc); 158 } 159 160 // Used solely in an assertion to figure out if the object we get here is something we in fact expect. Objects 161 // linked by NashornLinker should never reach here. 162 private static boolean isExpectedObject(final Object obj) { 163 return !(NashornLinker.canLinkTypeStatic(obj.getClass())); 164 } 165 166 private static GuardedInvocation linkNull(final LinkRequest linkRequest) { 167 final NashornCallSiteDescriptor desc = (NashornCallSiteDescriptor)linkRequest.getCallSiteDescriptor(); 168 final String operator = desc.getFirstOperator(); 169 switch (operator) { 170 case "new": 171 case "call": 172 throw typeError("not.a.function", "null"); 173 case "callMethod": 174 case "getMethod": 175 throw typeError("no.such.function", getArgument(linkRequest), "null"); 176 case "getProp": 177 case "getElem": 178 throw typeError("cant.get.property", getArgument(linkRequest), "null"); 179 case "setProp": 180 case "setElem": 181 throw typeError("cant.set.property", getArgument(linkRequest), "null"); 182 default: 183 break; 184 } 185 throw new AssertionError("unknown call type " + desc); 186 } 187 188 private static final Map<Class<?>, MethodHandle> CONVERTERS = new HashMap<>(); 189 static { 190 CONVERTERS.put(boolean.class, JSType.TO_BOOLEAN.methodHandle()); 191 CONVERTERS.put(double.class, JSType.TO_NUMBER.methodHandle()); 192 CONVERTERS.put(int.class, JSType.TO_INTEGER.methodHandle()); 193 CONVERTERS.put(long.class, JSType.TO_LONG.methodHandle()); 194 CONVERTERS.put(String.class, JSType.TO_STRING.methodHandle()); 195 } 196 197 private static String getArgument(final LinkRequest linkRequest) { 198 final CallSiteDescriptor desc = linkRequest.getCallSiteDescriptor(); 199 if (desc.getNameTokenCount() > 2) { 200 return desc.getNameToken(2); 201 } 202 return ScriptRuntime.safeToString(linkRequest.getArguments()[1]); 203 } 204} 205