Description Roman Zimmer 2010-09-23 05:03:47 EDT

Created attachment 179440 [details]
Sample project

I was trying to take advantage of the incremental generation process in Xpand (latest version from official update site).

When executing the workflow, the initial generation works flawless. However, if I regenerate my project, I get a NPE independently if I changed my model or not.

Here is a stack trace:

java.lang.NullPointerException
	at org.eclipse.xpand2.incremental.IncrementalGenerationCallback.hasRelevantChangeForFile(IncrementalGenerationCallback.java:181)
	at org.eclipse.xpand2.incremental.IncrementalGenerationCallback.handleFileStatement(IncrementalGenerationCallback.java:143)
	at org.eclipse.xpand2.incremental.IncrementalGenerationCallback.pre(IncrementalGenerationCallback.java:123)
	at org.eclipse.xpand2.incremental.IncrementalGenerationFacade.pre(IncrementalGenerationFacade.java:163)
	at org.eclipse.internal.xpand2.ast.Statement.evaluate(Statement.java:35)
	at org.eclipse.internal.xpand2.ast.AbstractDefinition.evaluate(AbstractDefinition.java:180)
	at org.eclipse.internal.xpand2.ast.ExpandStatement.invokeDefinition(ExpandStatement.java:246)
	at org.eclipse.internal.xpand2.ast.ExpandStatement.evaluateInternal(ExpandStatement.java:191)
	at org.eclipse.internal.xpand2.ast.Statement.evaluate(Statement.java:41)
	at org.eclipse.internal.xpand2.ast.AbstractDefinition.evaluate(AbstractDefinition.java:180)
	at org.eclipse.internal.xpand2.ast.ExpandStatement.invokeDefinition(ExpandStatement.java:246)
	at org.eclipse.internal.xpand2.ast.ExpandStatement.evaluateInternal(ExpandStatement.java:226)
	at org.eclipse.internal.xpand2.ast.Statement.evaluate(Statement.java:41)
	at org.eclipse.xpand2.Generator.invokeInternal2(Generator.java:333)
	at org.eclipse.xtend.expression.AbstractExpressionsUsingWorkflowComponent.invokeInternal(AbstractExpressionsUsingWorkflowComponent.java:239)
	at org.eclipse.emf.mwe.core.lib.AbstractWorkflowComponent.invoke(AbstractWorkflowComponent.java:126)
	at org.eclipse.emf.mwe.core.container.CompositeComponent.internalInvoke(CompositeComponent.java:104)
	at org.eclipse.emf.mwe.core.container.CompositeComponent.invoke(CompositeComponent.java:89)
	at org.eclipse.emf.mwe.core.WorkflowRunner.executeWorkflow(WorkflowRunner.java:408)
	at org.eclipse.emf.mwe.core.WorkflowRunner.run(WorkflowRunner.java:293)
	at org.eclipse.emf.mwe.core.WorkflowRunner.main(WorkflowRunner.java:241)

I tried to debug. Obviously there seems to be a wrong handling of null values. The NPE arises when checking files that have not changed since the last generation.

I attached a sample project to reproduce the issue. When first running src/main/resources/incremental.mwe, it should work. The second time it will crash and delete all perviously generated files. This would continue infinitely.

If you need further information, I'll try my best to provide them!