Re: [abc] [Bug 18] New: jimple type assigner can interact badly with cast pointcuts in extreme cases

The AspectJ differences between bytecode and source are clearly a mess in
search of a solution; but I don't think we should be adding to them with
EAJ. I'm not suggesting we should be in a rush to fix this, but I think
refusing to fix it ever is unreasonable; it's not particularly hard to fix
(just tag the casts that either do or don't come from bytecode).

Ganesh

On Thu, 16 Sep 2004, Ondrej Lhotak wrote:

> I'm trying to decide whether to close this WONTFIX or INVALID, and I
> don't believe there should be a test case in our test suite for it.
> If I understand correctly, this bug cannot happen on code produced by
> javac. Soot was designed from the ground up to handle any bytecode,
> even that not produced by Java. Afaik, abc, and the AspectJ language
> itself, weren't. If you give it code that is not typeable without a
> cast, it's unlikely that we're ever going to process it without adding
> a cast as long as we're using Soot (hence WONTFIX). I'm sure we make
> plenty of other much more serious assumptions about the code coming
> from javac than this. Consider all the synthetic attribute stuff, the
> helper methods, initializers that we inline, inner class attributes,
> weaving in the presence of exception handlers and synchronization, and
> I'm sure there's lots more. If we do want to define the semantics in
> terms of bytecode rather than Java source, then that's a huge change in
> the design of the compiler and even the language. If it's a bug that
> the language is defined in terms of Java and not bytecode, then let's
> make such a bug, and put the countless other issues into it as well.
> Ohterwise, we have plenty of real bugs to fix; let's not clutter things
> with stuff like this.
>
> Ondrej
>
> ----- Forwarded message from abc-bugs@comlab.ox.ac.uk -----
>
> From: abc-bugs@comlab.ox.ac.uk
> To: abc-bugs@comlab.ox.ac.uk
> Subject: [Bug 18] New: jimple type assigner can interact badly with cast pointcuts in extreme cases
> Date: Fri, 17 Sep 2004 00:55:41 +0100
>
> http://abc.comlab.ox.ac.uk/cgi-bin/bugzilla/show_bug.cgi?id=18
>
> Summary: jimple type assigner can interact badly with cast
> pointcuts in extreme cases
> Product: abc
> Version: unspecified
> Platform: PC
> OS/Version: Linux
> Status: NEW
> Severity: minor
> Priority: P2
> Component: EAJ
> AssignedTo: abc-bugs@comlab.ox.ac.uk
> ReportedBy: ganesh@comlab.ox.ac.uk
>
>
> This is a rather obscure bug even by my standards :-)
>
> If you consult the SAS 2000 paper which roughly describes the Jimple typing
> algorithm (http://www.sable.mcgill.ca/publications/papers/#sas2000), you find
> that in certain corner cases on bytecode not produced from Java source, casts
> get inserted by the Jimplifier.
>
> This means that the cast pointcut might find itself applying at a point that
> didn't have a cast in the original bytecode.
>
> Test case 992 exposes this bug.
>
>
>
> ------- You are receiving this mail because: -------
> You are the assignee for the bug, or are watching the assignee.
>
>
> ----- End forwarded message -----
>
>
>
Received on Fri Sep 17 02:02:59 2004