The Short Version:
I believe that we should change PState.setSuccess to take as an argument a 
PState.Mark and revert the diagnostics that have occurred since that Mark. The 
current uses of setSuccess leave diagnostics in the PState that should be 
discarded. Does this ruffle anyone’s feathers?

Long Version:

Pursuing Steve Lawrence’s comment in the pull request (#444) – I attempted to 
add an assert to the TDMLRunner’s doParseExpectSuccess that requires a 
successful test case to produce no error level diagnostics if it returns a 
success and an infoset.

e.g.
val actual = processor.parse(…)
val diagObjs = actual.getDiagnostics

if (actual.isProcessingError) {
  …
 // unrelated failure stuff
  …
} else {
  // If we think we've succeeded, verify there are no errors
  // captured in the diagnostics. Otherwise there's probably
  // an internal bug causing us to miss setting isProcessingError
  val hasErrorDiags = diagObjs.exists { diag =>
    diag.isError && !diag.isValidation
    }
    Assert.invariant(!hasErrorDiags)
}

This revealed that at least 35 test cases produce errors even though they 
succeed and provide an infoset. At first glance, I thought we just had more 
occurrences of AbsentRep and MissingSeparator being misused, but it appears the 
actual cause might be the use of
PState.setSuccess() to mask errors.

setSuccess appears to reset only the overall error/success state, but not 
affect diagnostics. This seems like an oversight. I would like to modify 
setSuccess:

final def setSuccess(pou: PState.Mark): Unit = {
    _processorStatus = Success
    this.diagnostics = pou.diagnostics
  }

Modifying the state without fully reverting to a PoU seems dangerous, but the 
other option seems to be rethinking our 7 uses of setSuccess entirely. Thoughts 
on this change?


[A picture containing object, clock  Description automatically generated]       
   Ian Carlson | Software Engineer
[Owl Cyber Defense]
W  icarl...@owlcyberdefense.com<https://owlcyberdefense.com/>
Connect with us!
Facebook<https://www.facebook.com/owlcyberdefense/> | 
LinkedIn<https://www.linkedin.com/company/owlcyberdefense/> | 
Twitter<https://twitter.com/owlcyberdefense>

[Find us at our next event. Click 
Here.]<https://owlcyberdefense.com/resources/events/?utm_source=owl-cyber-defense&utm_medium=email&utm_content=banner&utm_campaign=2020-events>

The information contained in this transmission is for the personal and 
confidential use of the individual or entity to which it is addressed.
If the reader is not the intended recipient, you are hereby notified that any 
review, dissemination, or copying of this communication is strictly prohibited.
If you have received this transmission in error, please notify the sender 
immediately


From: Beckerle, Mike<mailto:mbecke...@owlcyberdefense.com>
Sent: Monday, October 26, 2020 11:27 AM
To: dev@daffodil.apache.org<mailto:dev@daffodil.apache.org>
Subject: Re: 2399 - Changing error code for missing separators

There's some discussion in the PR, but for this mailing list I wanted to 
comment that this is indeed a deep area of algorithmic complexity in the 
Daffodil runtime.

Whether the code is actually factored adequately such that it enables 
implementing the right DFDL behavior is not entirely clear, but it is 
encouraging that this fix seems to be a small change without requiring 
refactoring.

I am sure there are other bugs in this general area of the code and getting 
everything exactly right so that every nuance of the DFDL spec is properly 
implemented is quite difficult and will require development of an extensive 
collection of tests that cover all these various combinations of features of 
DFDL.

I think right now, the important thing is no regression on any known existing 
DFDL schemas.

________________________________
From: Carlson, Ian <icarl...@owlcyberdefense.com>
Sent: Wednesday, October 21, 2020 6:04 PM
To: dev@daffodil.apache.org <dev@daffodil.apache.org>
Subject: 2399 - Changing error code for missing separators


All,



I’ve done a great deal of digging to find the cause of the bug DAFFODIL-2399. 
It appears to come down to

SeparatedSequenceChildParseResultHelper.scala line 282. In this case, we have 
found an out of scope delimiter %NL; before finding any elements, and as a 
result we abort parsing the sequence. We sensibly set the return status to 
ParseAttemptStatus.MissingSeparator. However, since the requiredOptional field 
is true, we have a status of success.



So far so good – everything works out until we roll back up to 
SequenceParserBases.scala, line 270. The MissingSeparator status again sets a 
status to success and terminates parsing of the sequence, but does not reset to 
a PoU. This is the reason our errors aren’t being discarded.



My suggested solution is simply to replace ParseAttemptStatus.MissingSeparator 
with ParseAttemptStatus.AbsentRep.



I bring this up to the mailing list because while this does seem to solve the 
problem without breaking any other tests, this is a very deep behavior in our 
parsing routine, and I want to see if anyone sees any potential dangers with 
the change.



I’ve created a pull request: 
https://github.com/apache/incubator-daffodil/pull/444 with this change for 
review.



[A picture containing object, clock  Description automatically generated]       
   Ian Carlson | Software Engineer

[Owl Cyber Defense]

W  icarl...@owlcyberdefense.com<https://owlcyberdefense.com/>

Connect with us!

Facebook<https://www.facebook.com/owlcyberdefense/> | 
LinkedIn<https://www.linkedin.com/company/owlcyberdefense/> | 
Twitter<https://twitter.com/owlcyberdefense>



[Find us at our next event. Click 
Here.]<https://owlcyberdefense.com/resources/events/?utm_source=owl-cyber-defense&utm_medium=email&utm_content=banner&utm_campaign=2020-events>



The information contained in this transmission is for the personal and 
confidential use of the individual or entity to which it is addressed.

If the reader is not the intended recipient, you are hereby notified that any 
review, dissemination, or copying of this communication is strictly prohibited.

If you have received this transmission in error, please notify the sender 
immediately




Reply via email to