FULL PRODUCT VERSION :


A DESCRIPTION OF THE PROBLEM :
I used a SOOT's jimple file to generate two classes with different version numbers. When I run the two classes using hotspot 9, the verifier behaves different, even though I believe that there exists a bug in the class. Seems that a class of a low version number is not checked carefully.

THE PROBLEM WAS REPRODUCIBLE WITH -Xint FLAG: Yes

THE PROBLEM WAS REPRODUCIBLE WITH -server FLAG: Yes

EXPECTED VERSUS ACTUAL BEHAVIOR :
A java verifyerror should be reported. Reason:
(1) When we generate a class with version 51 and run it on hotspot, a verify error is generated. It explains that there exists some stack frame error.

(2) When we run the class (version 46) using gcj-java, it reports an error
Exception in thread "main" java.lang.NoClassDefFoundError: M1433584778S
   at java.lang.Class.initializeClass(libgcj.so.14)
Caused by: java.lang.VerifyError: verification failed at PC 6 in M1433584778S:encodeObject(()V): merging initialized and uninitialized types
   at java.lang.Class.initializeClass(libgcj.so.14)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
Jimple file:
public class M1433584778S extends java.lang.Object
{
    private void <init>()
    {
        M1433584778S r0;

        r0 := @this: M1433584778S;
        specialinvoke r0.<java.lang.Object: void <init>()>();
        return;
    }

    public static void encodeObject()
    {
        java.lang.String r1, r2;
        java.lang.Throwable r3;
        
     label0:
        r1 = new java.lang.String;
        
     label1:
        return;

     label2:
        r3 := @caughtexception;
        goto label1;
  
        catch java.lang.RuntimeException from label0 to label1 with label2;
    }
    
        public static void main(java.lang.String[])
    {
        return;
    }
}

class file:
public class M1433584778S
  minor version: 0
  major version: 46
  flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
   #1 = Utf8 ([Ljava/lang/String;)V
   #2 = Utf8 java/lang/Object
   #3 = Utf8 <init>
   #4 = Class #2 // java/lang/Object
   #5 = NameAndType #3:#7 // "<init>":()V
   #6 = Class #14 // java/lang/String
   #7 = Utf8 ()V
   #8 = Utf8 M1433584778S
   #9 = Utf8 Code
  #10 = Utf8 main
  #11 = Utf8 SourceFile
  #12 = Class #8 // M1433584778S
  #13 = Class #15 // java/lang/RuntimeException
  #14 = Utf8 java/lang/String
  #15 = Utf8 java/lang/RuntimeException
  #16 = Utf8 Jasmin
  #17 = Methodref #4.#5 // java/lang/Object."<init>":()V
  #18 = Utf8 encodeObject
{
  public static void encodeObject();
    descriptor: ()V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=1, args_size=0
         0: new #6 // class java/lang/String
         3: astore_0
         4: return
         5: astore_0
         6: goto 4
      Exception table:
         from to target type
             0 4 5 Class java/lang/RuntimeException

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=0, locals=1, args_size=1
         0: return
}
SourceFile: "Jasmin"

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