--- /dev/null 2020-01-02 04:43:18.583999853 +0000 +++ new/src/share/classes/jdk/jfr/internal/instrument/ConstructorTracerWriter.java 2020-01-30 06:27:03.449855717 +0000 @@ -0,0 +1,86 @@ +/* + * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. Oracle designates this + * particular file as subject to the "Classpath" exception as provided + * by Oracle in the LICENSE file that accompanied this code. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +package jdk.jfr.internal.instrument; + +import java.io.ByteArrayInputStream; +import java.io.IOException; +import java.io.InputStream; + +import jdk.internal.org.objectweb.asm.ClassReader; +import jdk.internal.org.objectweb.asm.ClassVisitor; +import jdk.internal.org.objectweb.asm.ClassWriter; +import jdk.internal.org.objectweb.asm.MethodVisitor; +import jdk.internal.org.objectweb.asm.Opcodes; +import jdk.internal.org.objectweb.asm.Type; + +final class ConstructorTracerWriter extends ClassVisitor { + + private ConstructorWriter useInputParameter, noUseInputParameter; + + static byte[] generateBytes(Class clz, byte[] oldBytes) throws IOException { + InputStream in = new ByteArrayInputStream(oldBytes); + ClassReader cr = new ClassReader(in); + ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS); + ConstructorTracerWriter ctw = new ConstructorTracerWriter(cw, clz); + cr.accept(ctw, 0); + return cw.toByteArray(); + } + + private ConstructorTracerWriter(ClassVisitor cv, Class classToChange) { + super(Opcodes.ASM5, cv); + useInputParameter = new ConstructorWriter(classToChange, true); + noUseInputParameter = new ConstructorWriter(classToChange, false); + } + + private boolean isConstructor(String name) { + return name.equals(""); + } + + private boolean takesStringParameter(String desc) { + Type[] types = Type.getArgumentTypes(desc); + if (types.length > 0 && types[0].getClassName().equals(String.class.getName())) { + return true; + } + return false; + } + + @Override + public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) { + + MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions); + + // Get a hold of the constructors that takes a String as a parameter + if (isConstructor(name)) { + if (takesStringParameter(desc)) { + useInputParameter.setMethodVisitor(mv); + return useInputParameter; + } + noUseInputParameter.setMethodVisitor(mv); + return noUseInputParameter; + } + return mv; + } +}