Xtext Concrete Syntax Validation Error / Error Creating Abstract Feature Graphically

[philip-alldredge]

@lwrage I just found this issue and I'm not sure the best way to resolve. I would appreciate the thoughts of the appropriate SEI team members.

This is an issue that affects the graphical editor but it was triggered by a change in the core. Not sure if the best path forward is to modify the GE or the core.

When attempting to create an abstract feature graphically while the xtext document is not open, the feature is not created. The graphical editor calls validateConcreteSyntax() on the xtext resource and it returns the following error:

!MESSAGE org.osate.ge.internal.services.impl.DefaultAadlModificationService.modifySafely(): Feature AbstractFeature.featurePrototype must be set. Constraint: (featurePrototype|abstractFeatureClassifier?) Quantities: abstractFeatureClassifier:0, featurePrototype:0 Source: AadlPackage'midpoint_bug'.ownedPublicSection->PublicPackageSection'midpoint_bug_public'.ownedClassifier[1]->AbstractType'new_classifier'.ownedAbstractFeature[0]->AbstractFeature'new_classifier_new_feature2'

The graphical editor calls that function as a (potentially overcautious) precaution against saving an invalid model. If the check is removed, then everything seems to work correctly. However, if there is a fix on the core side, then that would be preferred.

I am guessing this is related to the fix for #883. Presumably xtext doesn't know how to serialize the feature.

[lwrage]

I'll have a look. Can you send me instruction how to reproduce the exception, please?

[philip-alldredge]

An exception isn't actually thrown, but the graphical editor does log the validation errors. This is an area where the GE needs to be improved with better error reporting.

Without having the AADL file open.

• Create an AADL Package (Graphical)
• Create an Abstract Type
• Attempt to create an Abstract Feature
• Messages will be logged in the error log of the running Eclipse and the console of the host/parent Eclipse. Any additional changes to the model will fail because of the same validation error. The fact that the change isn't reverted while not being serialized is another issue I need to look at.

!ENTRY org.osate.ge 1 0 2018-01-04 08:18:54.433 !MESSAGE org.osate.ge.internal.services.impl.DefaultAadlModificationService.modify(): Executing modification without a thread switch

!ENTRY org.osate.ge 4 0 2018-01-04 08:18:54.493 !MESSAGE org.osate.ge.internal.services.impl.DefaultAadlModificationService.modifySafely(): Error. Undoing modification

!ENTRY org.osate.ge 4 0 2018-01-04 08:18:54.493 !MESSAGE org.osate.ge.internal.services.impl.DefaultAadlModificationService.modifySafely(): Concrete Syntax Validation Errors:

!ENTRY org.osate.ge 4 0 2018-01-04 08:18:54.509 !MESSAGE org.osate.ge.internal.services.impl.DefaultAadlModificationService.modifySafely(): Feature AbstractFeature.featurePrototype must be set. Constraint: (featurePrototype|abstractFeatureClassifier?) Quantities: abstractFeatureClassifier:0, featurePrototype:0 Source: AadlPackage'abc'.ownedPublicSection->PublicPackageSection'abc_public'.ownedClassifier[0]->AbstractType'new_classifier'.ownedAbstractFeature[0]->AbstractFeature'new_classifier_new_feature'

[lwrage]

This looks like a bug in the concrete syntax validator: It determines that featurePrototype must be set, which is obviously wrong. BTW, I don't think it is necessary to call the concreteSyntaxValidator after you test serialization. AFAIK, the serializer never produces text with syntax or linking errors.

[lwrage]

I found that changing the grammar from ('prototype' featurePrototype | 'feature' featureClassifier?) to ('prototype' featurePrototype | 'feature' featureClassifier | 'feature') seems to be a work-around.

[philip-alldredge]

Okay. I'll disable the call to concreteSyntaxValidator to avoid similar issues in the future.