1 /*
   2  * Copyright (c) 2014, 2015, 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 8015927
  27  * @summary Class reference duplicates in constant pool
  28  * @modules jdk.jdeps/com.sun.tools.classfile
  29  * @clean ClassRefDupInConstantPoolTest$Duplicates.class
  30  * @run main ClassRefDupInConstantPoolTest
  31  */
  32 
  33 import java.util.TreeSet;
  34 
  35 import com.sun.tools.classfile.*;
  36 import com.sun.tools.classfile.ConstantPool.*;
  37 
  38 public class ClassRefDupInConstantPoolTest {
  39     public static void main(String[] args) throws Exception {
  40         ClassFile cls = ClassFile.read(ClassRefDupInConstantPoolTest.class.
  41                                        getResourceAsStream("ClassRefDupInConstantPoolTest$Duplicates.class"));
  42         ConstantPool pool = cls.constant_pool;
  43 
  44         int duplicates = 0;
  45         TreeSet<Integer> set = new TreeSet<>();
  46         for (CPInfo i : pool.entries()) {
  47             if (i.getTag() == ConstantPool.CONSTANT_Class) {
  48                 CONSTANT_Class_info ci = (CONSTANT_Class_info)i;
  49                 if (!set.add(ci.name_index)) {
  50                     duplicates++;
  51                     System.out.println("DUPLICATE CLASS REF " + ci.getName());
  52                 }
  53             }
  54         }
  55         if (duplicates > 0)
  56             throw new Exception("Test Failed");
  57     }
  58 
  59     class Duplicates {
  60         String concat(String s1, String s2) {
  61             return s1 + (s2 == s1 ? " " : s2);
  62         }
  63     }
  64 }