4 Replies Latest reply on Feb 21, 2008 8:35 AM by mburger

    Byte code limits?

    tdrums
    tdrums Sep 26, 2005 9:37 PM

      Are there limits (beyond normal VM limits) on how much code can be generated for a class? In my experiments it appears that after roughly 8,200 statements within a class, the offsets in the opcode get stored wrong to where I get a ClassCastException thrown from within ConstPool.getMethodrefName(). It appears an instance of NameAndTypeInfo is being returned instead of a MethodrefInfo.

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        • 1. Re: Byte code limits?
          mburger
          mburger Feb 20, 2008 9:32 AM (in response to tdrums)

          Hello!

          I have similar problems, while instrumenting classes I get various exceptions:

          Caused by: java.lang.NullPointerException
 at javassist.bytecode.ConstPool.getInterfaceMethodrefClassName(ConstPool.java:413)
 at javassist.expr.MethodCall.getClassName(MethodCall.java:91)
 at javassist.expr.MethodCall.getCtClass(MethodCall.java:75)
 at javassist.expr.MethodCall.getMethod(MethodCall.java:114)


          And: 

          Caused by: java.lang.ClassCastException: javassist.bytecode.ClassInfo
 at javassist.bytecode.ConstPool.getFieldrefClassName(ConstPool.java:254)
 at javassist.expr.FieldAccess.getClassName(FieldAccess.java:97)
 at javassist.expr.FieldAccess.getCtClass(FieldAccess.java:89)
 at javassist.expr.FieldAccess.getField(FieldAccess.java:112)


          Any idea what causes these failures?

          Regards

          Martin

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          • 2. Re: Byte code limits?
            mburger
            mburger Feb 20, 2008 9:52 AM (in response to tdrums)

             

            "mburger" wrote:
            I have similar problems, while instrumenting classes I get various exceptions:


            I just submitted an issue: http://jira.jboss.com/jira/browse/JASSIST-43

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            • 3. Re: Byte code limits?
              chiba
              chiba Feb 21, 2008 8:21 AM (in response to tdrums)

              Did you adjust the cursor of your ExprEditor subclass
              after inserting or deleting some bytecodes?

              The cursor might point to a wrong byte.

              (I submitted the same comment to JIRA)

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              • 4. Re: Byte code limits?
                mburger
                mburger Feb 21, 2008 8:35 AM (in response to tdrums)

                 

                "chiba" wrote:
                (I submitted the same comment to JIRA)


                Thanks for your fast reply. I continued the thread in JIRA. I think that is the right place in order to document the issue.

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