| /* |
| * 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. |
| * |
| * 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 vm.compiler.coverage.parentheses.share; |
| |
| import java.lang.reflect.Field; |
| import jdk.internal.org.objectweb.asm.ClassWriter; |
| import jdk.internal.org.objectweb.asm.MethodVisitor; |
| import jdk.internal.misc.Unsafe; |
| |
| import static jdk.internal.org.objectweb.asm.Opcodes.*; |
| |
| |
| import java.lang.reflect.Method; |
| import java.util.List; |
| |
| /** |
| * This class convert instructions sequence to java class file, load it to same JVM and then execute. |
| * This class uses Unsafe.defineAnonymousClass for class loading |
| */ |
| public class HotspotInstructionsExecutor implements InstructionsExecutor { |
| |
| private static final Object[] NO_CP_PATCHES = new Object[0]; |
| |
| private int stackSize; |
| |
| public HotspotInstructionsExecutor(int stackSize) { |
| this.stackSize = stackSize; |
| } |
| |
| @Override |
| public int execute(List<Instruction> instructions) throws ReflectiveOperationException { |
| Class execClass = generateClass(instructions); |
| Method execMethod = execClass.getMethod("exec"); |
| return (Integer) execMethod.invoke(null); |
| } |
| |
| private Class generateClass(List<Instruction> instructions) throws ClassNotFoundException { |
| String classNameForASM = "ExecClass"; |
| |
| ClassWriter cw = new ClassWriter(0); |
| cw.visit(V1_1, ACC_PUBLIC, classNameForASM, null, "java/lang/Object", null); |
| |
| // creates a MethodWriter for the 'main' method |
| MethodVisitor mw = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "exec", "()I", null, null); |
| |
| for (Instruction instruction : instructions) { |
| mw.visitInsn(instruction.opCode); |
| } |
| |
| mw.visitInsn(IRETURN); |
| mw.visitMaxs(stackSize, 2); |
| mw.visitEnd(); |
| |
| return getUnsafe().defineAnonymousClass(ClassWriter.class, cw.toByteArray(), NO_CP_PATCHES); |
| } |
| |
| private static Unsafe getUnsafe() { |
| return Unsafe.getUnsafe(); |
| } |
| } |