1 /* 2 * Copyright (c) 2016, 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 26 package java.lang.invoke; 27 28 import java.util.Map; 29 import jdk.internal.org.objectweb.asm.ClassWriter; 30 import jdk.internal.org.objectweb.asm.Opcodes; 31 32 import java.util.ArrayList; 33 import java.util.HashSet; 34 35 /** 36 * Helper class to assist the GenerateJLIClassesPlugin to get access to 37 * generate classes ahead of time. 38 */ 39 class GenerateJLIClassesHelper { 40 41 static byte[] generateDirectMethodHandleHolderClassBytes(String className, 42 MethodType[] methodTypes, int[] types) { 43 LambdaForm[] forms = new LambdaForm[methodTypes.length]; 44 String[] names = new String[methodTypes.length]; 45 for (int i = 0; i < forms.length; i++) { 46 forms[i] = DirectMethodHandle.makePreparedLambdaForm(methodTypes[i], 47 types[i]); 48 names[i] = forms[i].kind.defaultLambdaName; 49 } 50 return generateCodeBytesForLFs(className, names, forms); 51 } 52 53 static byte[] generateDelegatingMethodHandleHolderClassBytes(String className, 54 MethodType[] methodTypes) { 55 56 // deduplicate 57 HashSet<MethodType> dedupSet = new HashSet<>(); 58 ArrayList<LambdaForm> forms = new ArrayList<>(); 59 ArrayList<String> names = new ArrayList<>(); 60 for (int i = 0; i < methodTypes.length; i++) { 61 // generate methods representing the DelegatingMethodHandle 62 if (!dedupSet.contains(methodTypes[i])) { 63 // reinvokers are variant with the associated SpeciesData 64 // and shape of the target LF, but we can easily pregenerate 65 // the basic reinvokers associated with Species_L. Ultimately we 66 // may want to consider pregenerating more of these, which will 67 // require an even more complex naming scheme 68 LambdaForm reinvoker = makeReinvokerFor(methodTypes[i]); 69 forms.add(reinvoker); 70 String speciesSig = BoundMethodHandle 71 .speciesData(reinvoker).fieldSignature(); 72 assert(speciesSig.equals("L")); 73 names.add(reinvoker.kind.defaultLambdaName + "_" + speciesSig); 74 75 LambdaForm delegate = makeDelegateFor(methodTypes[i]); 76 forms.add(delegate); 77 names.add(delegate.kind.defaultLambdaName); 78 79 dedupSet.add(methodTypes[i]); 80 } 81 } 82 return generateCodeBytesForLFs(className, 83 names.toArray(new String[0]), 84 forms.toArray(new LambdaForm[0])); 85 } 86 87 /* 88 * Generate customized code for a set of LambdaForms of specified types into 89 * a class with a specified name. 90 */ 91 private static byte[] generateCodeBytesForLFs(String className, 92 String[] names, LambdaForm[] forms) { 93 94 ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); 95 cw.visit(Opcodes.V1_8, Opcodes.ACC_PRIVATE + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, 96 className, null, InvokerBytecodeGenerator.INVOKER_SUPER_NAME, null); 97 cw.visitSource(className.substring(className.lastIndexOf('/') + 1), null); 98 99 for (int i = 0; i < forms.length; i++) { 100 addMethod(className, names[i], forms[i], 101 forms[i].methodType(), cw); 102 } 103 return cw.toByteArray(); 104 } 105 106 private static void addMethod(String className, String methodName, LambdaForm form, 107 MethodType type, ClassWriter cw) { 108 InvokerBytecodeGenerator g 109 = new InvokerBytecodeGenerator(className, methodName, form, type); 110 g.setClassWriter(cw); 111 g.addMethod(); 112 } 113 114 private static LambdaForm makeReinvokerFor(MethodType type) { 115 MethodHandle emptyHandle = MethodHandles.empty(type); 116 return DelegatingMethodHandle.makeReinvokerForm(emptyHandle, 117 MethodTypeForm.LF_REBIND, 118 BoundMethodHandle.speciesData_L(), 119 BoundMethodHandle.speciesData_L().getterFunction(0)); 120 } 121 122 private static LambdaForm makeDelegateFor(MethodType type) { 123 MethodHandle handle = MethodHandles.empty(type); 124 return DelegatingMethodHandle.makeReinvokerForm( 125 handle, 126 MethodTypeForm.LF_DELEGATE, 127 DelegatingMethodHandle.class, 128 DelegatingMethodHandle.NF_getTarget); 129 } 130 131 static Map.Entry<String, byte[]> generateConcreteBMHClassBytes( 132 final String types) { 133 for (char c : types.toCharArray()) { 134 if ("LIJFD".indexOf(c) < 0) { 135 throw new IllegalArgumentException("All characters must " 136 + "correspond to a basic field type: LIJFD"); 137 } 138 } 139 String shortTypes = LambdaForm.shortenSignature(types); 140 final String className = 141 BoundMethodHandle.Factory.speciesInternalClassName(shortTypes); 142 return Map.entry(className, 143 BoundMethodHandle.Factory.generateConcreteBMHClassBytes( 144 shortTypes, types, className)); 145 } 146 }