/* * Copyright (c) 2014, 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. */ /* * @test * @bug 8058243 * @summary Reduce size of bytecode for large switch statements * @library /tools/lib * @build ToolBox * @run main SwitchMetricTest */ import java.net.URL; import java.util.List; public class SwitchMetricTest { public static void main(String... args) throws Exception { new SwitchMetricTest().run(); } // This code should produce a tableswitch class Test1 { int m(int x) { switch (x) { case 1: case 2: case 3: case 4: case 5: return 1; default: return 0; } } } // This code should produce a lookupswitch class Test2 { int m(int x) { switch (x) { case 1: case 2: case 3: case 4: case 50: return 1; default: return 0; } } } void check(String classfile, String bytecode) throws Exception { ToolBox tb = new ToolBox(); URL url = SwitchMetricTest.class.getResource(classfile); List result = tb.new JavapTask() .options("-c") .classes(url.getFile()) .run() .write(ToolBox.OutputKind.DIRECT) .getOutputLines(ToolBox.OutputKind.DIRECT); List matches = tb.grep(bytecode, result); if (matches.isEmpty()) throw new Exception(bytecode + " not found"); } void run() throws Exception { check("SwitchMetricTest$Test1.class", "tableswitch"); check("SwitchMetricTest$Test2.class", "lookupswitch"); } }