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 8028553

    27  * @summary Test that VerifyError is not thrown when 'overriding' a static method.

    28  * @run main FinalStatic

    29  */

    30 

    31 import java.lang.reflect.*;

    32 import jdk.internal.org.objectweb.asm.ClassWriter;

    33 import jdk.internal.org.objectweb.asm.MethodVisitor;

    34 import jdk.internal.org.objectweb.asm.Opcodes;

    35 

    36 /*

    37  *  class A { static final int m() {return FAIL; } }

    38  *  class B extends A { int m() { return PASS; } }

    39  *  class FinalStatic {

    40  *      public static void main () {

    41  *          Object b = new B();

    42  *          b.m();

    43  *      }

    44  *  }

    45  */

    46 public class FinalStatic {

    47 

    48     static final String CLASS_NAME_A = "A";

    49     static final String CLASS_NAME_B = "B";

    50     static final int FAILED = 0;

    51     static final int EXPECTED = 1234;

    52 

    53     static class TestClassLoader extends ClassLoader implements Opcodes {

    54 

    55         @Override

    56         public Class findClass(String name) throws ClassNotFoundException {

    57             byte[] b;

    58             try {

    59                 b = loadClassData(name);

    60             } catch (Throwable th) {

    61                 // th.printStackTrace();

    62                 throw new ClassNotFoundException("Loading error", th);

    63             }

    64             return defineClass(name, b, 0, b.length);

    65         }

    66 

    67         private byte[] loadClassData(String name) throws Exception {

    68             ClassWriter cw = new ClassWriter(0);

    69             MethodVisitor mv;

    70             switch (name) {

    71                case CLASS_NAME_A:

    72                     cw.visit(52, ACC_SUPER | ACC_PUBLIC, CLASS_NAME_A, null, "java/lang/Object", null);

    73                     {

    74                         mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);

    75                         mv.visitCode();

    76                         mv.visitVarInsn(ALOAD, 0);

    77                         mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");

    78                         mv.visitInsn(RETURN);

    79                         mv.visitMaxs(1, 1);

    80                         mv.visitEnd();

    81 

    82                         mv = cw.visitMethod(ACC_FINAL | ACC_STATIC, "m", "()I", null, null);

    83                         mv.visitCode();

    84                         mv.visitLdcInsn(FAILED);

    85                         mv.visitInsn(IRETURN);

    86                         mv.visitMaxs(1, 1);

    87                         mv.visitEnd();

    88                     }

    89                     break;

    90                 case CLASS_NAME_B:

    91                     cw.visit(52, ACC_SUPER | ACC_PUBLIC, CLASS_NAME_B, null, CLASS_NAME_A, null);

    92                     {

    93                         mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);

    94                         mv.visitCode();

    95                         mv.visitVarInsn(ALOAD, 0);

    96                         mv.visitMethodInsn(INVOKESPECIAL, CLASS_NAME_A, "<init>", "()V");

    97                         mv.visitInsn(RETURN);

    98                         mv.visitMaxs(1, 1);

    99                         mv.visitEnd();

   100 

   101                         mv = cw.visitMethod(ACC_PUBLIC, "m", "()I", null, null);

   102                         mv.visitCode();

   103                         mv.visitLdcInsn(EXPECTED);

   104                         mv.visitInsn(IRETURN);

   105                         mv.visitMaxs(1, 1);

   106                         mv.visitEnd();

   107 

   108                     }

   109                     break;

   110                 default:

   111                     break;

   112             }

   113             cw.visitEnd();

   114 

   115             return cw.toByteArray();

   116         }

   117     }

   118 

   119     public static void main(String[] args) throws Exception {

   120         TestClassLoader tcl = new TestClassLoader();

   121         Class<?> a = tcl.loadClass(CLASS_NAME_A);

   122         Class<?> b = tcl.loadClass(CLASS_NAME_B);

   123         Object inst = b.newInstance();

   124         Method[] meths = b.getDeclaredMethods();

   125 

   126         Method m = meths[0];

   127         int mod = m.getModifiers();

   128         if ((mod & Modifier.FINAL) != 0) {

   129             throw new Exception("FAILED: " + m + " is FINAL");

   130         }

   131         if ((mod & Modifier.STATIC) != 0) {

   132             throw new Exception("FAILED: " + m + " is STATIC");

   133         }

   134 

   135         m.setAccessible(true);

   136         if (!m.invoke(inst).equals(EXPECTED)) {

   137               throw new Exception("FAILED: " + EXPECTED + " from " + m);

   138         }

   139 

   140         System.out.println("Passed.");

   141     }

   142 }