1 /*

     2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 /*

    25  * @test

    26  * @bug 8058243

    27  * @summary Reduce size of bytecode for large switch statements

    28  * @library /tools/lib

    29  * @build ToolBox

    30  * @run main SwitchMetricTest

    31  */

    32 

    33 import java.net.URL;

    34 import java.util.List;

    35 

    36 public class SwitchMetricTest {

    37     public static void main(String... args) throws Exception {

    38         new SwitchMetricTest().run();

    39     }

    40 

    41     // This code should produce a tableswitch

    42     class Test1 {

    43         int m(int x) {

    44             switch (x) {

    45             case 1:

    46             case 2:

    47             case 3:

    48             case 4:

    49             case 5: return 1;

    50             default: return 0;

    51             }

    52         }

    53     }

    54 

    55     // This code should produce a lookupswitch

    56     class Test2 {

    57         int m(int x) {

    58             switch (x) {

    59             case 1:

    60             case 2:

    61             case 3:

    62             case 4:

    63             case 50: return 1;

    64             default: return 0;

    65             }

    66         }

    67     }

    68 

    69     void check(String classfile, String bytecode) throws Exception {

    70         ToolBox tb = new ToolBox();

    71         URL url = SwitchMetricTest.class.getResource(classfile);

    72         List<String> result = tb.new JavapTask()

    73                 .options("-c")

    74                 .classes(url.getFile())

    75                 .run()

    76                 .write(ToolBox.OutputKind.DIRECT)

    77                 .getOutputLines(ToolBox.OutputKind.DIRECT);

    78 

    79         List<String> matches = tb.grep(bytecode, result);

    80         if (matches.isEmpty())

    81             throw new Exception(bytecode + " not found");

    82     }

    83 

    84     void run() throws Exception {

    85         check("SwitchMetricTest$Test1.class", "tableswitch");

    86         check("SwitchMetricTest$Test2.class", "lookupswitch");

    87     }

    88 }