addCatch doesn't work

[rezahay]

I used addCatch as follows:

=================================================
for (int i = 0; i < allMethods.length; i++) {
CtMethod method = allMethods;
if (method.getName().startsWith("set")) {
StringBuffer insCode = new StringBuffer();
insCode.append('{');
//insCode.append("System.out.println($e);");
//insCode.append("System.out.println(\"8888888888888888\");");
//insCode.append("java.lang.StackTraceElement[] ste = $e.getStackTrace();");
//insCode.append("System.out.println(ste[0].getLineNumber());");
//insCode.append("System.out.println($e.getMessage());");
//insCode.append("System.out.println(\"9999999999999999\");");
insCode.append('}');
method.addCatch(insCode.toString(), expClass);
}
}
==================================================

When I look at the decompiled (by JAD) class-file, I see the instrumentation is done perfectly. But If I want to run the instrumented class-file I get the following error-msg from JVM:

================================================
java.lang.VerifyError: (class: nl/vu/cs/iids/MyPoint, method: setRectangular signature: (DD)V) Falling off the end of the code
==============================================

MyPoint is an example class with a number of set-methods. (It is the example class which is shiped by AspectJ).

I have tried also with the javassist 2.6. But I got the same problem.

Thanks

[chiba]

Ah...
Can you do

method.addCatch("{return;}", expClass);

and make sure it works?

There is a note in both the tutorial and the javadoc.

Note that the inserted code fragment must end with a throw or return statement.

Thank you!

[rezahay]

Thank you very, chiba for your response. I used {return;} and it works. But if there are methods with non-void return types then {return;} is not enough. Therefore I used (within my addCatch) {Object result; return ($r)result;}. But I get the following javassist compiler error:
==============================================

javassist.CannotCompileException: [source error] no such class: $r
at javassist.CtBehavior.addCatch(CtBehavior.java:722)
at javassist.CtBehavior.addCatch(CtBehavior.java:670)

==============================================

It seems that the javassist compiler doesn't recognize $r. Is it not allowed to use $r in the addCatch? Or do I do something wrong?

Thanks in advance

[chiba]

I think it's a bug of Javassist.
I'll fix this bug within a few days. Please wait for a while.
(Fixing that bug seems very easy but it takes time to write
test code etc. I could not have time to do it today.)