/* * Copyright 2018 the original author or authors. * * Licensed 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.glowroot.agent.weaving; import org.objectweb.asm.ClassWriter; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Type; import org.glowroot.agent.weaving.ClassLoaders.LazyDefinedClass; import static org.objectweb.asm.Opcodes.ACC_PUBLIC; import static org.objectweb.asm.Opcodes.ACC_SUPER; import static org.objectweb.asm.Opcodes.ALOAD; import static org.objectweb.asm.Opcodes.ASTORE; import static org.objectweb.asm.Opcodes.BASTORE; import static org.objectweb.asm.Opcodes.ICONST_0; import static org.objectweb.asm.Opcodes.ICONST_1; import static org.objectweb.asm.Opcodes.INVOKESPECIAL; import static org.objectweb.asm.Opcodes.NEWARRAY; import static org.objectweb.asm.Opcodes.RETURN; import static org.objectweb.asm.Opcodes.T_BOOLEAN; import static org.objectweb.asm.Opcodes.V1_7; // this is valid bytecode, but cannot be generated from valid Java code // e.g. jacoco does this public class GenerateHackedConstructorBytecode { static LazyDefinedClass generateHackedConstructorBytecode() throws Exception { ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS); MethodVisitor mv; cw.visit(V1_7, ACC_PUBLIC + ACC_SUPER, "HackedConstructorBytecode", null, Test.class.getName().replace('.', '/'), new String[] {}); { mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null); mv.visitCode(); mv.visitInsn(ICONST_1); mv.visitIntInsn(NEWARRAY, T_BOOLEAN); mv.visitVarInsn(ASTORE, 1); mv.visitVarInsn(ALOAD, 0); mv.visitMethodInsn(INVOKESPECIAL, Test.class.getName().replace('.', '/'), "<init>", "()V", false); mv.visitVarInsn(ALOAD, 1); mv.visitInsn(ICONST_0); mv.visitInsn(ICONST_1); mv.visitInsn(BASTORE); mv.visitInsn(RETURN); mv.visitMaxs(0, 0); mv.visitEnd(); } cw.visitEnd(); return ImmutableLazyDefinedClass.builder() .type(Type.getObjectType("HackedConstructorBytecode")) .bytes(cw.toByteArray()) .build(); } public static class Test {} }