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  1. JDK
  2. JDK-6689318

VerifyError thrown on previously verified class

    Details

    • Subcomponent:
    • CPU:
      x86
    • OS:
      windows_xp

      Description

      FULL PRODUCT VERSION :
      java version "1.6.0_05"
      Java(TM) SE Runtime Environment (build 1.6.0_05-b13)
      Java HotSpot(TM) Client VM (build 10.0-b19, mixed mode, sharing)

      ADDITIONAL OS VERSION INFORMATION :
      Microsoft Windows XP [Version 5.1.2600]

      A DESCRIPTION OF THE PROBLEM :
      The verfier in the latest 1.6.0 releases seem to behave different for this class file. The input class (and the source it was created from) is a bit silly, but I ran across this in the real world

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      Run this program with 1.6.0_04 (or 05) and you should get a VerifyError

      Running the same program with 1.6.0_03 (or 02) and no such error is thrown

      The setting of maxStack to zero is a reasonable outcome of class transformer that is recalculating max stack. The instructions from offset 3 to 5 are unreachable (see javap output below)

      public static void main(java.lang.String[]) throws java.sql.SQLException;
        Code:
         Stack=0, Locals=2, Args_size=1
         0: goto 6
         3: astore_1
         4: aload_1
         5: athrow
         6: return
        Exception table:
         from to target type
           3 4 3 any


      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      Not actually sure who is wrong in this equation. The verifier behavior difference is a little confusing, and it seems that it shouldn't bother with dead code paths with regards to maxStack.

      javac also seems to be producing a strange class to begin with, so maybe that is another issue.



      ERROR MESSAGES/STACK TRACES THAT OCCUR :
      Exception in thread "main" java.lang.VerifyError: (class: Foo, method: main signature: ([Ljava/lang/String;)V) Stack size too large
      at java.lang.Class.getDeclaredMethods0(Native Method)
      at java.lang.Class.privateGetDeclaredMethods(Class.java:2395)
      at java.lang.Class.getMethod0(Class.java:2642)
      at java.lang.Class.getMethod(Class.java:1579)
      at Test.defineAndInvokeMain(Test.java:15)
      at Test.main(Test.java:11)


      REPRODUCIBILITY :
      This bug can be reproduced always.

      ---------- BEGIN SOURCE ----------
      public class Test {

      public static void main(String[] args) throws Exception {
      defineAndInvokeMain(clazz);

      // change maxStack to zero for main([Ljava/lang/String;)V
      clazz[257] = 0;

      // Throws VerifyError with 1.6.0_04, 1.6.0_05, 1.5.0_14 and 1.5.0_15
      // No error on 1.6.0_02, 1.6.0_03, 1.5.0_13 (and probably others)
      defineAndInvokeMain(clazz);
      }

      static void defineAndInvokeMain(byte[] classBytes) throws Exception {
      new Loader().define("Foo", classBytes).getMethod("main",
      new Class[]{String[].class}).invoke(null,
      new Object[]{new String[]{}});
      System.err.println("class defined okay");
      }

      static class Loader extends ClassLoader {
      Class<?> define(String name, byte[] b) {
      return defineClass(name, b, 0, b.length);
      }
      }

      /**
      * This source code produced the class below using javac from sun 1.5.0_15
      * on winXP.
      *
      * <pre>
      * import java.sql.*;
      *
      * public class Foo {
      * public static void main(String[] args) throws SQLException {
      * try {
      * //
      * } catch (Exception e) {
      * System.out.println(e);
      * } finally {
      * //
      * }
      * }
      * }
      * </pre>
      */
      private static final byte[] clazz = new byte[]{(byte) 202, (byte) 254,
      (byte) 186, (byte) 190, (byte) 0, (byte) 0, (byte) 0, (byte) 49,
      (byte) 0, (byte) 18, (byte) 10, (byte) 0, (byte) 3, (byte) 0,
      (byte) 14, (byte) 7, (byte) 0, (byte) 15, (byte) 7, (byte) 0,
      (byte) 16, (byte) 1, (byte) 0, (byte) 6, (byte) 60, (byte) 105,
      (byte) 110, (byte) 105, (byte) 116, (byte) 62, (byte) 1, (byte) 0,
      (byte) 3, (byte) 40, (byte) 41, (byte) 86, (byte) 1, (byte) 0,
      (byte) 4, (byte) 67, (byte) 111, (byte) 100, (byte) 101, (byte) 1,
      (byte) 0, (byte) 15, (byte) 76, (byte) 105, (byte) 110, (byte) 101,
      (byte) 78, (byte) 117, (byte) 109, (byte) 98, (byte) 101,
      (byte) 114, (byte) 84, (byte) 97, (byte) 98, (byte) 108,
      (byte) 101, (byte) 1, (byte) 0, (byte) 4, (byte) 109, (byte) 97,
      (byte) 105, (byte) 110, (byte) 1, (byte) 0, (byte) 22, (byte) 40,
      (byte) 91, (byte) 76, (byte) 106, (byte) 97, (byte) 118, (byte) 97,
      (byte) 47, (byte) 108, (byte) 97, (byte) 110, (byte) 103,
      (byte) 47, (byte) 83, (byte) 116, (byte) 114, (byte) 105,
      (byte) 110, (byte) 103, (byte) 59, (byte) 41, (byte) 86, (byte) 1,
      (byte) 0, (byte) 10, (byte) 69, (byte) 120, (byte) 99, (byte) 101,
      (byte) 112, (byte) 116, (byte) 105, (byte) 111, (byte) 110,
      (byte) 115, (byte) 7, (byte) 0, (byte) 17, (byte) 1, (byte) 0,
      (byte) 10, (byte) 83, (byte) 111, (byte) 117, (byte) 114,
      (byte) 99, (byte) 101, (byte) 70, (byte) 105, (byte) 108,
      (byte) 101, (byte) 1, (byte) 0, (byte) 8, (byte) 70, (byte) 111,
      (byte) 111, (byte) 46, (byte) 106, (byte) 97, (byte) 118,
      (byte) 97, (byte) 12, (byte) 0, (byte) 4, (byte) 0, (byte) 5,
      (byte) 1, (byte) 0, (byte) 3, (byte) 70, (byte) 111, (byte) 111,
      (byte) 1, (byte) 0, (byte) 16, (byte) 106, (byte) 97, (byte) 118,
      (byte) 97, (byte) 47, (byte) 108, (byte) 97, (byte) 110,
      (byte) 103, (byte) 47, (byte) 79, (byte) 98, (byte) 106,
      (byte) 101, (byte) 99, (byte) 116, (byte) 1, (byte) 0, (byte) 21,
      (byte) 106, (byte) 97, (byte) 118, (byte) 97, (byte) 47,
      (byte) 115, (byte) 113, (byte) 108, (byte) 47, (byte) 83,
      (byte) 81, (byte) 76, (byte) 69, (byte) 120, (byte) 99, (byte) 101,
      (byte) 112, (byte) 116, (byte) 105, (byte) 111, (byte) 110,
      (byte) 0, (byte) 33, (byte) 0, (byte) 2, (byte) 0, (byte) 3,
      (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 2,
      (byte) 0, (byte) 1, (byte) 0, (byte) 4, (byte) 0, (byte) 5,
      (byte) 0, (byte) 1, (byte) 0, (byte) 6, (byte) 0, (byte) 0,
      (byte) 0, (byte) 29, (byte) 0, (byte) 1, (byte) 0, (byte) 1,
      (byte) 0, (byte) 0, (byte) 0, (byte) 5, (byte) 42, (byte) 183,
      (byte) 0, (byte) 1, (byte) 177, (byte) 0, (byte) 0, (byte) 0,
      (byte) 1, (byte) 0, (byte) 7, (byte) 0, (byte) 0, (byte) 0,
      (byte) 6, (byte) 0, (byte) 1, (byte) 0, (byte) 0, (byte) 0,
      (byte) 3, (byte) 0, (byte) 9, (byte) 0, (byte) 8, (byte) 0,
      (byte) 9, (byte) 0, (byte) 2, (byte) 0, (byte) 6, (byte) 0,
      (byte) 0, (byte) 0, (byte) 47, (byte) 0, (byte) 1, (byte) 0,
      (byte) 2, (byte) 0, (byte) 0, (byte) 0, (byte) 7, (byte) 167,
      (byte) 0, (byte) 6, (byte) 76, (byte) 43, (byte) 191, (byte) 177,
      (byte) 0, (byte) 1, (byte) 0, (byte) 3, (byte) 0, (byte) 4,
      (byte) 0, (byte) 3, (byte) 0, (byte) 0, (byte) 0, (byte) 1,
      (byte) 0, (byte) 7, (byte) 0, (byte) 0, (byte) 0, (byte) 14,
      (byte) 0, (byte) 3, (byte) 0, (byte) 0, (byte) 0, (byte) 11,
      (byte) 0, (byte) 3, (byte) 0, (byte) 9, (byte) 0, (byte) 6,
      (byte) 0, (byte) 12, (byte) 0, (byte) 10, (byte) 0, (byte) 0,
      (byte) 0, (byte) 4, (byte) 0, (byte) 1, (byte) 0, (byte) 11,
      (byte) 0, (byte) 1, (byte) 0, (byte) 12, (byte) 0, (byte) 0,
      (byte) 0, (byte) 2, (byte) 0, (byte) 13};
      }

      ---------- END SOURCE ----------

      Release Regression From : 6u3
      The above release value was the last known release where this
      bug was not reproducible. Since then there has been a regression.

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            • Assignee:
              abuckley Alex Buckley
              Reporter:
              ndcosta Nelson Dcosta (Inactive)
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                Updated:
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