Error propagation in feature group type result in errors.

[philip-alldredge]

Summary

Expected and Current Behavior

It should be possible to define an error propagation in a feature group type. This currently results in an error.

Steps to Reproduce

1. Define an emv2 error propagation in a feature group type.
2. Errors regarding being unable to resolve the feature and the error are reported.

package emv2_test
public
	feature group fgt
	features 
		ip1: in data port;
		
		annex emv2 {**
			use types ErrorLibrary;
			error propagations
				ip1: in propagation {ServiceError};
			end propagations;
		**};
	end fgt;	

end emv2_test;

[philip-alldredge]

For reference: E.4 (L1), (L3), (21), and (22). Page 69 in the official SAE PDF is the portions of the standard that reference feature group types having error propagations.

[joeseibel]

There are a few different problems here that need to be fixed. First of all, the validator throws a ClassCastException when a subclause exists in a feature group type, even if the subclause is empty. Here is the exception:

java.lang.ClassCastException: org.osate.aadl2.impl.FeatureGroupTypeImpl cannot be cast to org.osate.aadl2.ComponentClassifier
	at org.osate.xtext.aadl2.errormodel.validation.ErrorModelValidator.checkDuplicateSubclause(ErrorModelValidator.java:558)
	at org.osate.xtext.aadl2.errormodel.validation.ErrorModelValidator.caseErrorModelSubclause(ErrorModelValidator.java:296)
	...

Secondly, the scope provider does not resolve the references to ip1 and ServiceError.

Thirdly, the validator throws another ClassCastException when an error propagation is in a feature group type:

java.lang.ClassCastException: org.osate.aadl2.impl.FeatureGroupTypeImpl cannot be cast to org.osate.aadl2.ComponentClassifier
	at org.osate.xtext.aadl2.errormodel.util.EMV2Util.getAssociatedClassifier(EMV2Util.java:203)
	at org.osate.xtext.aadl2.errormodel.util.EMV2Util.getAllContainingClassifierEMV2Subclauses(EMV2Util.java:176)
	at org.osate.xtext.aadl2.errormodel.util.EMV2Util.findErrorContainment(EMV2Util.java:381)
	at org.osate.xtext.aadl2.errormodel.validation.ErrorModelValidator.checkTypePropagationAndContainment(ErrorModelValidator.java:530)
	at org.osate.xtext.aadl2.errormodel.validation.ErrorModelValidator.caseErrorPropagation(ErrorModelValidator.java:209)
	...

These stack traces show that the validator and EMV2Util assume that a subclause is always in a ComponentClassifier. There are probably lots and lots of places in EMV2 code that make this assumption.

[lwrage]

It is not clear if this construct really makes sense. See saeaadl/emv2#50.

[lwrage]

We don't support error model annex subclauses in feature group types any longer.