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 jdk.internal.org.objectweb.asm.ClassWriter;
  29 import jdk.internal.org.objectweb.asm.Opcodes;
  30 import sun.invoke.util.Wrapper;
  31 
  32 import java.util.ArrayList;
  33 import java.util.HashSet;
  34 import java.util.List;
  35 import java.util.Map;
  36 
  37 /**
  38  * Helper class to assist the GenerateJLIClassesPlugin to get access to
  39  * generate classes ahead of time.
  40  */
  41 class GenerateJLIClassesHelper {
  42 
  43     static byte[] generateBasicFormsClassBytes(String className) {
  44         ArrayList<LambdaForm> forms = new ArrayList<>();
  45         ArrayList<String> names = new ArrayList<>();
  46         HashSet<String> dedupSet = new HashSet<>();
  47         for (LambdaForm.BasicType type : LambdaForm.BasicType.values()) {
  48             LambdaForm zero = LambdaForm.zeroForm(type);
  49             String name = zero.kind.defaultLambdaName
  50                    + "_" + zero.returnType().basicTypeChar();
  51             if (dedupSet.add(name)) {
  52                 names.add(name);
  53                 forms.add(zero);
  54             }
  55 
  56             LambdaForm identity = LambdaForm.identityForm(type);
  57             name = identity.kind.defaultLambdaName
  58                    + "_" + identity.returnType().basicTypeChar();
  59             if (dedupSet.add(name)) {
  60                 names.add(name);
  61                 forms.add(identity);
  62             }
  63         }
  64         return generateCodeBytesForLFs(className,
  65                 names.toArray(new String[0]),
  66                 forms.toArray(new LambdaForm[0]));
  67     }
  68 
  69     static byte[] generateDirectMethodHandleHolderClassBytes(String className,
  70             MethodType[] methodTypes, int[] types) {
  71         ArrayList<LambdaForm> forms = new ArrayList<>();
  72         ArrayList<String> names = new ArrayList<>();
  73         for (int i = 0; i < methodTypes.length; i++) {
  74             LambdaForm form = DirectMethodHandle
  75                     .makePreparedLambdaForm(methodTypes[i], types[i]);
  76             forms.add(form);
  77             names.add(form.kind.defaultLambdaName);
  78         }
  79         for (Wrapper wrapper : Wrapper.values()) {
  80             if (wrapper == Wrapper.VOID) {
  81                 continue;
  82             }
  83             for (byte b = DirectMethodHandle.AF_GETFIELD; b < DirectMethodHandle.AF_LIMIT; b++) {
  84                 int ftype = DirectMethodHandle.ftypeKind(wrapper.primitiveType());
  85                 LambdaForm form = DirectMethodHandle
  86                         .makePreparedFieldLambdaForm(b, /*isVolatile*/false, ftype);
  87                 if (form.kind != LambdaForm.Kind.GENERIC) {
  88                     forms.add(form);
  89                     names.add(form.kind.defaultLambdaName);
  90                 }
  91                 // volatile
  92                 form = DirectMethodHandle
  93                         .makePreparedFieldLambdaForm(b, /*isVolatile*/true, ftype);
  94                 if (form.kind != LambdaForm.Kind.GENERIC) {
  95                     forms.add(form);
  96                     names.add(form.kind.defaultLambdaName);
  97                 }
  98             }
  99         }
 100         return generateCodeBytesForLFs(className,
 101                 names.toArray(new String[0]),
 102                 forms.toArray(new LambdaForm[0]));
 103     }
 104 
 105     static byte[] generateDelegatingMethodHandleHolderClassBytes(String className,
 106             MethodType[] methodTypes) {
 107 
 108         HashSet<MethodType> dedupSet = new HashSet<>();
 109         ArrayList<LambdaForm> forms = new ArrayList<>();
 110         ArrayList<String> names = new ArrayList<>();
 111         for (int i = 0; i < methodTypes.length; i++) {
 112             // generate methods representing the DelegatingMethodHandle
 113             if (dedupSet.add(methodTypes[i])) {
 114                 // reinvokers are variant with the associated SpeciesData
 115                 // and shape of the target LF, but we can easily pregenerate
 116                 // the basic reinvokers associated with Species_L. Ultimately we
 117                 // may want to consider pregenerating more of these, which will
 118                 // require an even more complex naming scheme
 119                 LambdaForm reinvoker = makeReinvokerFor(methodTypes[i]);
 120                 forms.add(reinvoker);
 121                 String speciesSig = BoundMethodHandle.formSpeciesData(reinvoker).key();
 122                 assert(speciesSig.equals("L"));
 123                 names.add(reinvoker.kind.defaultLambdaName + "_" + speciesSig);
 124 
 125                 LambdaForm delegate = makeDelegateFor(methodTypes[i]);
 126                 forms.add(delegate);
 127                 names.add(delegate.kind.defaultLambdaName);
 128             }
 129         }
 130         return generateCodeBytesForLFs(className,
 131                 names.toArray(new String[0]),
 132                 forms.toArray(new LambdaForm[0]));
 133     }
 134 
 135     static byte[] generateInvokersHolderClassBytes(String className,
 136             MethodType[] methodTypes) {
 137 
 138         HashSet<MethodType> dedupSet = new HashSet<>();
 139         ArrayList<LambdaForm> forms = new ArrayList<>();
 140         ArrayList<String> names = new ArrayList<>();
 141         int[] types = {
 142             MethodTypeForm.LF_EX_LINKER,
 143             MethodTypeForm.LF_EX_INVOKER,
 144             MethodTypeForm.LF_GEN_LINKER,
 145             MethodTypeForm.LF_GEN_INVOKER
 146         };
 147         for (int i = 0; i < methodTypes.length; i++) {
 148             // generate methods representing invokers of the specified type
 149             if (dedupSet.add(methodTypes[i])) {
 150                 for (int type : types) {
 151                     LambdaForm invokerForm = Invokers.invokeHandleForm(methodTypes[i],
 152                             /*customized*/false, type);
 153                     forms.add(invokerForm);
 154                     names.add(invokerForm.kind.defaultLambdaName);
 155                 }
 156             }
 157         }
 158         return generateCodeBytesForLFs(className,
 159                 names.toArray(new String[0]),
 160                 forms.toArray(new LambdaForm[0]));
 161     }
 162 
 163     /*
 164      * Generate customized code for a set of LambdaForms of specified types into
 165      * a class with a specified name.
 166      */
 167     private static byte[] generateCodeBytesForLFs(String className,
 168             String[] names, LambdaForm[] forms) {
 169 
 170         ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
 171         cw.visit(Opcodes.V1_8, Opcodes.ACC_PRIVATE + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
 172                 className, null, InvokerBytecodeGenerator.INVOKER_SUPER_NAME, null);
 173         cw.visitSource(className.substring(className.lastIndexOf('/') + 1), null);
 174 
 175         for (int i = 0; i < forms.length; i++) {
 176             addMethod(className, names[i], forms[i],
 177                     forms[i].methodType(), cw);
 178         }
 179         return cw.toByteArray();
 180     }
 181 
 182     private static void addMethod(String className, String methodName, LambdaForm form,
 183             MethodType type, ClassWriter cw) {
 184         InvokerBytecodeGenerator g
 185                 = new InvokerBytecodeGenerator(className, methodName, form, type);
 186         g.setClassWriter(cw);
 187         g.addMethod();
 188     }
 189 
 190     private static LambdaForm makeReinvokerFor(MethodType type) {
 191         MethodHandle emptyHandle = MethodHandles.empty(type);
 192         return DelegatingMethodHandle.makeReinvokerForm(emptyHandle,
 193                 MethodTypeForm.LF_REBIND,
 194                 BoundMethodHandle.speciesData_L(),
 195                 BoundMethodHandle.speciesData_L().getterFunction(0));
 196     }
 197 
 198     private static LambdaForm makeDelegateFor(MethodType type) {
 199         MethodHandle handle = MethodHandles.empty(type);
 200         return DelegatingMethodHandle.makeReinvokerForm(
 201                 handle,
 202                 MethodTypeForm.LF_DELEGATE,
 203                 DelegatingMethodHandle.class,
 204                 DelegatingMethodHandle.NF_getTarget);
 205     }
 206 
 207     @SuppressWarnings({"rawtypes", "unchecked"})
 208     static Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
 209             final String types) {
 210         for (char c : types.toCharArray()) {
 211             if ("LIJFD".indexOf(c) < 0) {
 212                 throw new IllegalArgumentException("All characters must "
 213                         + "correspond to a basic field type: LIJFD");
 214             }
 215         }
 216         final BoundMethodHandle.BMHSpecies species = BoundMethodHandle.SPECIALIZER.findSpecies(types);
 217         final String className = species.speciesCode().getName();
 218         final ClassSpecializer.Factory factory = BoundMethodHandle.SPECIALIZER.factory();
 219         final byte[] code = factory.generateConcreteSpeciesCodeFile(className, species);
 220         return Map.entry(className, code);
 221     }
 222 
 223 }