Re: [abc] RE: bug in TM codegen?

I'm somewhat confused about how that change in TMStateMachine could have
produced the problem you reported. TMStateMachine is, unless I'm very
mistaken, a highly compile-time concept. It is our representation of the
NFA, which is in effect partially evaluated to produce specialised code.
There is no representation of the state machine at runtime. So, if this
were indeed the cause of your issue, I would expect a compile-time NPE
rather than a runtime one.

Having said that, personally I tend to use LinkedHashSets for their
predictable iteration order whenever possible -- we've been bitten too
often by nondeterministic iteration-order bugs.

- Pavel

Eric Bodden wrote:

>Ok, I found out what was causing this. In TMStateMachine I had replaced the LinkedHashSet for nodes with an IdentityHashSet. Apparently however the indexing codegen relies on the iteration order of this hash set. (I am not entirely sure in what way, but it seems to be the case. - Any thoughts?) So I just switched back to LinkedHashSet and that did the trick.
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>Eric
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>>-----Original Message-----
>>From: Eric Bodden
>>Sent: Monday, October 23, 2006 12:16 PM
>>To: 'abc@comlab.ox.ac.uk'
>>Subject: RE: bug in TM codegen?
>>
>>Please ignore my previous mail. It works properly with the HEAD
>>version. So it's a fault on my side. Sorry!!
>>
>>Eric
>>
>>
>>
>>
>>>-----Original Message-----
>>>From: Eric Bodden
>>>Sent: Monday, October 23, 2006 12:05 PM
>>>To: 'abc@comlab.ox.ac.uk'
>>>Subject: bug in TM codegen?
>>>
>>>Hi.
>>>
>>>I found something that looks a lot like a bug in the code generation.
>>>First I thought it was me doing something silly but the same happens
>>>
>>>
>>in
>>
>>
>>>the main abc branch, too.
>>>
>>>If I just compile the attached tracematch with the abc standard
>>>options, and then run ASyncIteration, I get the following exception:
>>>
>>>mucuna ~/workspaces/abc/Test/out $ java -cp .:../../abc-
>>>
>>>
>>tmopt/lib/abc-
>>
>>
>>>runtime.jar ASyncIteration Exception in thread "main"
>>>java.lang.NullPointerException
>>> at Constraint$tracematch$0.lookup1(Jasmin)
>>> at Constraint$tracematch$0.queue(Jasmin)
>>> at
>>>ASyncIteration$SyncCheck.afterReturning$1(ASyncIteration.java)
>>> at ASyncIteration.main(ASyncIteration.java:18)
>>>
>>>This happens regardless of whether indexing is enabled or disabled,
>>>
>>>
>>so
>>
>>
>>>I assume that the bug is in ASyncIteration and not in the conjuct or
>>>disjunct class.
>>>
>>>I have the generated jimple attached. It would be great if you guys
>>>could look into this ASAP because it prevents some of my benchmarks
>>>from running.
>>>
>>>Cheers,
>>>Eric
>>>
>>>--
>>>Eric Bodden
>>>Sable Research Group, McGill University
>>>Montréal, Québec, Canada
>>>
>>>
>>>
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Received on Mon Oct 23 17:57:14 2006