| /* |
| * 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.apache.felix.scrplugin.helper; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| |
| import org.apache.felix.scrplugin.Log; |
| import org.apache.felix.scrplugin.SCRDescriptorException; |
| import org.objectweb.asm.ClassReader; |
| import org.objectweb.asm.ClassWriter; |
| import org.objectweb.asm.Label; |
| import org.objectweb.asm.MethodVisitor; |
| import org.objectweb.asm.Opcodes; |
| import org.objectweb.asm.tree.ClassNode; |
| |
| /** |
| * Helper class for injecting/generating accessor methods for |
| * unary references. |
| */ |
| public abstract class ClassModifier { |
| |
| /** |
| * Add bind/unbind methods |
| * @param className The class name in which the methods are injected |
| * @param referenceName Name of the reference |
| * @param referenceType Type of the reference |
| * @param fieldName Name of the field |
| * @param fieldType Type of the field |
| * @param createBind Name of the bind method or null |
| * @param createUnbind Name of the unbind method or null |
| * @param outputDirectory Output directory where the class file is stored |
| * @throws SCRDescriptorException |
| */ |
| public static void addMethods(final String className, |
| final String referenceName, |
| final String referenceType, |
| final String fieldName, |
| final String fieldType, |
| final boolean createBind, |
| final boolean createUnbind, |
| final ClassLoader classLoader, |
| final String outputDirectory, |
| final Log logger) |
| throws SCRDescriptorException { |
| // now do byte code manipulation |
| final String fileName = outputDirectory + File.separatorChar + className.replace('.', File.separatorChar) + ".class"; |
| final ClassNode cn = new ClassNode(); |
| try { |
| final FileInputStream fis = new FileInputStream(fileName); |
| try { |
| final ClassReader reader = new ClassReader(fis); |
| reader.accept(cn, 0); |
| } |
| finally { |
| fis.close(); |
| } |
| |
| // For target Java7 and above use: ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES |
| final int mask = (cn.version > 50 ? ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES : 0); |
| final ClassWriter writer = new ClassWriter(mask) { |
| |
| @Override |
| protected String getCommonSuperClass(final String type1, final String type2) { |
| Class<?> c, d; |
| try { |
| c = classLoader.loadClass(type1.replace('/', '.')); |
| d = classLoader.loadClass(type2.replace('/', '.')); |
| } catch (final Exception e) { |
| throw new RuntimeException(e.toString(), e); |
| } |
| if (c.isAssignableFrom(d)) { |
| return type1; |
| } |
| if (d.isAssignableFrom(c)) { |
| return type2; |
| } |
| if (c.isInterface() || d.isInterface()) { |
| return "java/lang/Object"; |
| } |
| do { |
| c = c.getSuperclass(); |
| } while (!c.isAssignableFrom(d)); |
| return c.getName().replace('.', '/'); |
| } |
| |
| }; |
| |
| cn.accept(writer); |
| if ( createBind ) { |
| logger.debug("Adding bind " + className + " " + fieldName); |
| |
| createMethod(writer, className, referenceName, referenceType, fieldName, fieldType, true); |
| } |
| if ( createUnbind ) { |
| logger.debug("Adding unbind " + className + " " + fieldName); |
| |
| createMethod(writer, className, referenceName, referenceType, fieldName, fieldType, false); |
| } |
| |
| final FileOutputStream fos = new FileOutputStream(fileName); |
| try { |
| fos.write(writer.toByteArray()); |
| } |
| finally { |
| fos.close(); |
| } |
| } catch (final Exception e) { |
| throw new SCRDescriptorException("Unable to add methods to " + className, referenceType, e); |
| } |
| } |
| |
| private static void createMethod(final ClassWriter cw, final String className, final String referenceName, final String referenceTypeName, final String fieldName, final String fieldTypeName, final boolean bind) { |
| final org.objectweb.asm.Type referenceType = org.objectweb.asm.Type.getType("L" + referenceTypeName.replace('.', '/') + ";"); |
| final org.objectweb.asm.Type fieldType = org.objectweb.asm.Type.getType("L" + fieldTypeName.replace('.', '/') + ";"); |
| final String methodName = (bind ? "" : "un") + "bind" + referenceName.substring(0, 1).toUpperCase() + referenceName.substring(1); |
| final MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PROTECTED, methodName, "(" + referenceType.toString() + ")V", null, null); |
| mv.visitVarInsn(Opcodes.ALOAD, 0); |
| if ( bind ) { |
| mv.visitVarInsn(referenceType.getOpcode(Opcodes.ILOAD), 1); |
| mv.visitFieldInsn(Opcodes.PUTFIELD, className.replace('.', '/'), fieldName, fieldType.toString()); |
| } else { |
| mv.visitFieldInsn(Opcodes.GETFIELD, className.replace('.', '/'), fieldName, fieldType.toString()); |
| mv.visitVarInsn(Opcodes.ALOAD, 1); |
| final Label jmpLabel = new Label(); |
| mv.visitJumpInsn(Opcodes.IF_ACMPNE, jmpLabel); |
| mv.visitVarInsn(Opcodes.ALOAD, 0); |
| mv.visitInsn(Opcodes.ACONST_NULL); |
| mv.visitFieldInsn(Opcodes.PUTFIELD, className.replace('.', '/'), fieldName, fieldType.toString()); |
| mv.visitLabel(jmpLabel); |
| } |
| mv.visitInsn(Opcodes.RETURN); |
| mv.visitMaxs(2, 2); |
| } |
| } |