Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the 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. */ package org.codehaus.groovy.runtime.callsite; import org.codehaus.groovy.classgen.GeneratorContext; import org.codehaus.groovy.classgen.asm.BytecodeHelper; import org.codehaus.groovy.reflection.CachedClass; import org.codehaus.groovy.reflection.CachedMethod; import org.codehaus.groovy.reflection.android.AndroidSupport; import org.codehaus.groovy.vmplugin.VMPluginFactory; import org.objectweb.asm.ClassWriter; import org.objectweb.asm.Label; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; import java.lang.reflect.Constructor; import java.lang.reflect.Modifier; public class CallSiteGenerator { private CallSiteGenerator() { } private static MethodVisitor writeMethod(ClassWriter cw, String name, int argumentCount, final String superClass, CachedMethod cachedMethod, String receiverType, String parameterDescription, boolean useArray) { MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "call" + name, "(L" + receiverType + ";" + parameterDescription + ")Ljava/lang/Object;", null, null); mv.visitCode(); final Label tryStart = new Label(); mv.visitLabel(tryStart); // call for checking if method is still valid for (int i = 0; i < argumentCount; ++i) mv.visitVarInsn(Opcodes.ALOAD, i); mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, superClass, "checkCall", "(Ljava/lang/Object;" + parameterDescription + ")Z", false); Label l0 = new Label(); mv.visitJumpInsn(Opcodes.IFEQ, l0); // valid method branch Class callClass = cachedMethod.getDeclaringClass().getTheClass(); boolean useInterface = callClass.isInterface(); String type = BytecodeHelper.getClassInternalName(callClass.getName()); String descriptor = BytecodeHelper.getMethodDescriptor(cachedMethod.getReturnType(), cachedMethod.getNativeParameterTypes()); // prepare call int invokeMethodCode = Opcodes.INVOKEVIRTUAL; if (cachedMethod.isStatic()) { invokeMethodCode = Opcodes.INVOKESTATIC; } else { mv.visitVarInsn(Opcodes.ALOAD, 1); BytecodeHelper.doCast(mv, callClass); if (useInterface) invokeMethodCode = Opcodes.INVOKEINTERFACE; } Class<?>[] parameters = cachedMethod.getPT(); int size = parameters.length; for (int i = 0; i < size; i++) { if (useArray) { // unpack argument from Object[] mv.visitVarInsn(Opcodes.ALOAD, 2); BytecodeHelper.pushConstant(mv, i); mv.visitInsn(Opcodes.AALOAD); } else { mv.visitVarInsn(Opcodes.ALOAD, i + 2); } // cast argument to parameter class, inclusive unboxing // for methods with primitive types BytecodeHelper.doCast(mv, parameters[i]); } // make call mv.visitMethodInsn(invokeMethodCode, type, cachedMethod.getName(), descriptor, useInterface); // produce result BytecodeHelper.box(mv, cachedMethod.getReturnType()); if (cachedMethod.getReturnType() == void.class) { mv.visitInsn(Opcodes.ACONST_NULL); } // return mv.visitInsn(Opcodes.ARETURN); // fall back after method change mv.visitLabel(l0); for (int i = 0; i < argumentCount; ++i) mv.visitVarInsn(Opcodes.ALOAD, i); if (!useArray) { mv.visitMethodInsn(Opcodes.INVOKESTATIC, "org/codehaus/groovy/runtime/ArrayUtil", "createArray", "(" + parameterDescription + ")[Ljava/lang/Object;", false); } mv.visitMethodInsn(Opcodes.INVOKESTATIC, "org/codehaus/groovy/runtime/callsite/CallSiteArray", "defaultCall" + name, "(Lorg/codehaus/groovy/runtime/callsite/CallSite;L" + receiverType + ";[Ljava/lang/Object;)Ljava/lang/Object;", false); mv.visitInsn(Opcodes.ARETURN); // exception unwrapping for stackless exceptions final Label tryEnd = new Label(); mv.visitLabel(tryEnd); final Label catchStart = new Label(); mv.visitLabel(catchStart); mv.visitMethodInsn(Opcodes.INVOKESTATIC, "org/codehaus/groovy/runtime/ScriptBytecodeAdapter", "unwrap", "(Lgroovy/lang/GroovyRuntimeException;)Ljava/lang/Throwable;", false); mv.visitInsn(Opcodes.ATHROW); mv.visitTryCatchBlock(tryStart, tryEnd, catchStart, "groovy/lang/GroovyRuntimeException"); mv.visitMaxs(0, 0); mv.visitEnd(); return mv; } public static void genCallWithFixedParams(ClassWriter cw, String name, final String superClass, CachedMethod cachedMethod, String receiverType) { if (cachedMethod.getParamsCount() > 4) return; StringBuilder pdescb = new StringBuilder(); final int pc = cachedMethod.getParamsCount(); for (int i = 0; i != pc; ++i) pdescb.append("Ljava/lang/Object;"); writeMethod(cw, name, pc + 2, superClass, cachedMethod, receiverType, pdescb.toString(), false); } public static void genCallXxxWithArray(ClassWriter cw, final String name, final String superClass, CachedMethod cachedMethod, String receiverType) { writeMethod(cw, name, 3, superClass, cachedMethod, receiverType, "[Ljava/lang/Object;", true); } private static void genConstructor(ClassWriter cw, final String superClass, String internalName) { MethodVisitor mv; mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "(Lorg/codehaus/groovy/runtime/callsite/CallSite;Lgroovy/lang/MetaClassImpl;Lgroovy/lang/MetaMethod;[Ljava/lang/Class;Ljava/lang/reflect/Constructor;)V", null, null); mv.visitCode(); mv.visitVarInsn(Opcodes.ALOAD, 0); mv.visitVarInsn(Opcodes.ALOAD, 1); mv.visitVarInsn(Opcodes.ALOAD, 2); mv.visitVarInsn(Opcodes.ALOAD, 3); mv.visitVarInsn(Opcodes.ALOAD, 4); mv.visitMethodInsn(Opcodes.INVOKESPECIAL, superClass, "<init>", "(Lorg/codehaus/groovy/runtime/callsite/CallSite;Lgroovy/lang/MetaClassImpl;Lgroovy/lang/MetaMethod;[Ljava/lang/Class;)V", false); mv.visitVarInsn(Opcodes.ALOAD, 5); mv.visitFieldInsn(Opcodes.PUTSTATIC, internalName, "__constructor__", "Ljava/lang/reflect/Constructor;"); mv.visitInsn(Opcodes.RETURN); mv.visitMaxs(0, 0); mv.visitEnd(); } private static void classHeader(ClassWriter cw, String internalName, String superName) { if (VMPluginFactory.getPlugin().getVersion() >= 8) { cw.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC | Opcodes.ACC_SYNTHETIC, internalName, null, superName, null); } else { cw.visit(Opcodes.V1_4, Opcodes.ACC_PUBLIC | Opcodes.ACC_SYNTHETIC, internalName, null, superName, null); } } public static byte[] genPogoMetaMethodSite(CachedMethod cachedMethod, ClassWriter cw, String name) { String internalName = name.replace('.', '/'); classHeader(cw, internalName, "org/codehaus/groovy/runtime/callsite/PogoMetaMethodSite"); cw.visitField(Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC, "__constructor__", "Ljava/lang/reflect/Constructor;", null, null); genConstructor(cw, "org/codehaus/groovy/runtime/callsite/PogoMetaMethodSite", internalName); genCallXxxWithArray(cw, "Current", "org/codehaus/groovy/runtime/callsite/PogoMetaMethodSite", cachedMethod, "groovy/lang/GroovyObject"); genCallXxxWithArray(cw, "", "org/codehaus/groovy/runtime/callsite/PogoMetaMethodSite", cachedMethod, "java/lang/Object"); genCallWithFixedParams(cw, "Current", "org/codehaus/groovy/runtime/callsite/PogoMetaMethodSite", cachedMethod, "groovy/lang/GroovyObject"); genCallWithFixedParams(cw, "", "org/codehaus/groovy/runtime/callsite/PogoMetaMethodSite", cachedMethod, "java/lang/Object"); cw.visitEnd(); return cw.toByteArray(); } public static byte[] genPojoMetaMethodSite(CachedMethod cachedMethod, ClassWriter cw, String name) { String internalName = name.replace('.', '/'); classHeader(cw, internalName, "org/codehaus/groovy/runtime/callsite/PojoMetaMethodSite"); cw.visitField(Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC, "__constructor__", "Ljava/lang/reflect/Constructor;", null, null); genConstructor(cw, "org/codehaus/groovy/runtime/callsite/PojoMetaMethodSite", internalName); genCallXxxWithArray(cw, "", "org/codehaus/groovy/runtime/callsite/PojoMetaMethodSite", cachedMethod, "java/lang/Object"); genCallWithFixedParams(cw, "", "org/codehaus/groovy/runtime/callsite/PojoMetaMethodSite", cachedMethod, "java/lang/Object"); cw.visitEnd(); return cw.toByteArray(); } public static byte[] genStaticMetaMethodSite(CachedMethod cachedMethod, ClassWriter cw, String name) { String internalName = name.replace('.', '/'); classHeader(cw, internalName, "org/codehaus/groovy/runtime/callsite/StaticMetaMethodSite"); cw.visitField(Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC, "__constructor__", "Ljava/lang/reflect/Constructor;", null, null); genConstructor(cw, "org/codehaus/groovy/runtime/callsite/StaticMetaMethodSite", internalName); genCallXxxWithArray(cw, "", "org/codehaus/groovy/runtime/callsite/StaticMetaMethodSite", cachedMethod, "java/lang/Object"); genCallXxxWithArray(cw, "Static", "org/codehaus/groovy/runtime/callsite/StaticMetaMethodSite", cachedMethod, "java/lang/Class"); genCallWithFixedParams(cw, "", "org/codehaus/groovy/runtime/callsite/StaticMetaMethodSite", cachedMethod, "java/lang/Object"); genCallWithFixedParams(cw, "Static", "org/codehaus/groovy/runtime/callsite/StaticMetaMethodSite", cachedMethod, "java/lang/Class"); cw.visitEnd(); return cw.toByteArray(); } private static ClassWriter makeClassWriter() { if (VMPluginFactory.getPlugin().getVersion() >= 8) { return new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES); } else { return new ClassWriter(ClassWriter.COMPUTE_MAXS); } } public static Constructor compilePogoMethod(CachedMethod cachedMethod) { ClassWriter cw = makeClassWriter(); final CachedClass declClass = cachedMethod.getDeclaringClass(); final CallSiteClassLoader callSiteLoader = declClass.getCallSiteLoader(); final String name = callSiteLoader.createClassName(cachedMethod.getName()); final byte[] bytes = genPogoMetaMethodSite(cachedMethod, cw, name); return callSiteLoader.defineClassAndGetConstructor(name, bytes); } public static Constructor compilePojoMethod(CachedMethod cachedMethod) { ClassWriter cw = makeClassWriter(); final CachedClass declClass = cachedMethod.getDeclaringClass(); final CallSiteClassLoader callSiteLoader = declClass.getCallSiteLoader(); final String name = callSiteLoader.createClassName(cachedMethod.getName()); final byte[] bytes = genPojoMetaMethodSite(cachedMethod, cw, name); return callSiteLoader.defineClassAndGetConstructor(name, bytes); } public static Constructor compileStaticMethod(CachedMethod cachedMethod) { ClassWriter cw = makeClassWriter(); final CachedClass declClass = cachedMethod.getDeclaringClass(); final CallSiteClassLoader callSiteLoader = declClass.getCallSiteLoader(); final String name = callSiteLoader.createClassName(cachedMethod.getName()); final byte[] bytes = genStaticMetaMethodSite(cachedMethod, cw, name); return callSiteLoader.defineClassAndGetConstructor(name, bytes); } public static boolean isCompilable(CachedMethod method) { return (GroovySunClassLoader.sunVM != null || Modifier.isPublic(method.cachedClass.getModifiers()) && method.isPublic() && publicParams(method)) && !AndroidSupport.isRunningAndroid() && containsOnlyValidChars(method.getName()); } private static boolean publicParams(CachedMethod method) { for (Class nativeParamType : method.getNativeParameterTypes()) { if (!Modifier.isPublic(nativeParamType.getModifiers())) return false; } return true; } private static boolean containsOnlyValidChars(String name) { // TODO: this might not do enough or too much // But it is a good start without spreading logic everywhere String encoded = GeneratorContext.encodeAsValidClassName(name); return encoded.equals(name); } }