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Bug 354150

Summary:	Nameprovider cannot access references
Product:	[Modeling] TMF	Reporter:	Christian Dietrich <christian.dietrich.opensource>
Component:	Xtext	Assignee:	Project Inbox <tmf.xtext-inbox>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	normal
Priority:	P3	CC:	sebastian.zarnekow
Version:	unspecified
Target Milestone:	---
Hardware:	PC
OS:	Windows XP
Whiteboard:

Description Christian Dietrich

2011-08-08 11:08:02 EDT

Build Identifier: 2.0.0

It is impossible to access references from within an IQualifiedNameProvider

Having this simple Grammar

grammar org.xtext.example.mydsl.MyDsl with org.eclipse.xtext.common.Terminals

generate myDsl "http://www.xtext.org/example/mydsl/MyDsl"

Model:
	entities+=Entity*
	usages+=Usage*
;

Entity:
	"entity" name=ID 
;


Usage:
	"usage" entity=[Entity]
;

and this simple nameprovider

public class MyDslNameProvider extends DefaultDeclarativeQualifiedNameProvider {

	QualifiedName qualifiedName(Usage u) {
		return QualifiedName.create(u.getEntity().getName());
	}
	
}

i get java.lang.AssertionError: Cyclic resolution of lazy links : Usage.entity->Usage.entity
	at org.eclipse.xtext.linking.lazy.LazyLinkingResource.handleCyclicResolution(LazyLinkingResource.java:206)
	at org.eclipse.xtext.linking.lazy.LazyLinkingResource.getEObject(LazyLinkingResource.java:159)
	at org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.getEObject(ResourceSetImpl.java:219)
	at org.eclipse.emf.ecore.util.EcoreUtil.resolve(EcoreUtil.java:203)
	at org.eclipse.emf.ecore.util.EcoreUtil.resolve(EcoreUtil.java:263)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eResolveProxy(BasicEObjectImpl.java:1483)
	at org.xtext.example.mydsl.myDsl.impl.UsageImpl.getEntity(UsageImpl.java:77)
	at org.xtext.example.mydsl.naming.MyDslNameProvider.qualifiedName(MyDslNameProvider.java:10)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.xtext.util.PolymorphicDispatcher.invoke(PolymorphicDispatcher.java:291)
	at org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider$2.get(DefaultDeclarativeQualifiedNameProvider.java:62)
	at org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider$2.get(DefaultDeclarativeQualifiedNameProvider.java:1)
	at org.eclipse.xtext.util.OnChangeEvictingCache.get(OnChangeEvictingCache.java:46)
	at org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider.getFullyQualifiedName(DefaultDeclarativeQualifiedNameProvider.java:58)
	at org.eclipse.xtext.naming.IQualifiedNameProvider$AbstractImpl.apply(IQualifiedNameProvider.java:31)
	at org.eclipse.xtext.naming.IQualifiedNameProvider$AbstractImpl.apply(IQualifiedNameProvider.java:1)
	at org.eclipse.xtext.scoping.Scopes$2.apply(Scopes.java:90)
	at org.eclipse.xtext.scoping.Scopes$2.apply(Scopes.java:1)
	at com.google.common.collect.Iterators$8.next(Iterators.java:697)
	at com.google.common.collect.Iterators$7.computeNext(Iterators.java:602)
	at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:135)
	at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:130)
	at org.eclipse.xtext.scoping.impl.MultimapBasedSelectable.setExportedObjects(MultimapBasedSelectable.java:97)
	at org.eclipse.xtext.scoping.impl.MultimapBasedSelectable.<init>(MultimapBasedSelectable.java:36)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider.internalGetAllDescriptions(ImportedNamespaceAwareLocalScopeProvider.java:216)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider$2.get(ImportedNamespaceAwareLocalScopeProvider.java:204)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider$2.get(ImportedNamespaceAwareLocalScopeProvider.java:1)
	at org.eclipse.xtext.util.OnChangeEvictingCache.get(OnChangeEvictingCache.java:46)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider.getAllDescriptions(ImportedNamespaceAwareLocalScopeProvider.java:202)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider.getResourceScope(ImportedNamespaceAwareLocalScopeProvider.java:112)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider.getResourceScope(ImportedNamespaceAwareLocalScopeProvider.java:101)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider.getScope(ImportedNamespaceAwareLocalScopeProvider.java:89)
	at org.eclipse.xtext.scoping.impl.ImportedNamespaceAwareLocalScopeProvider.getScope(ImportedNamespaceAwareLocalScopeProvider.java:87)
	at org.eclipse.xtext.scoping.impl.AbstractDeclarativeScopeProvider.delegateGetScope(AbstractDeclarativeScopeProvider.java:72)
	at org.eclipse.xtext.scoping.impl.AbstractDeclarativeScopeProvider.getScope(AbstractDeclarativeScopeProvider.java:102)
	at org.eclipse.xtext.linking.impl.DefaultLinkingService.getScope(DefaultLinkingService.java:59)
	at org.eclipse.xtext.linking.impl.DefaultLinkingService.getLinkedObjects(DefaultLinkingService.java:119)
	at org.eclipse.xtext.linking.lazy.LazyLinkingResource.getEObject(LazyLinkingResource.java:169)
	at org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.getEObject(ResourceSetImpl.java:219)
	at org.eclipse.emf.ecore.util.EcoreUtil.resolve(EcoreUtil.java:203)
	at org.eclipse.emf.ecore.util.EcoreUtil.resolve(EcoreUtil.java:263)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eResolveProxy(BasicEObjectImpl.java:1483)
	at org.xtext.example.mydsl.myDsl.impl.UsageImpl.getEntity(UsageImpl.java:77)
	at org.xtext.example.mydsl.naming.MyDslNameProvider.qualifiedName(MyDslNameProvider.java:10)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.xtext.util.PolymorphicDispatcher.invoke(PolymorphicDispatcher.java:291)
	at org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider$2.get(DefaultDeclarativeQualifiedNameProvider.java:62)
	at org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider$2.get(DefaultDeclarativeQualifiedNameProvider.java:1)
	at org.eclipse.xtext.util.OnChangeEvictingCache.get(OnChangeEvictingCache.java:46)
	at org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider.getFullyQualifiedName(DefaultDeclarativeQualifiedNameProvider.java:58)
	at org.eclipse.xtext.resource.impl.DefaultResourceDescriptionStrategy.createEObjectDescriptions(DefaultResourceDescriptionStrategy.java:65)
	at org.eclipse.xtext.resource.impl.DefaultResourceDescription.computeExportedObjects(DefaultResourceDescription.java:88)
	at org.eclipse.xtext.resource.impl.DefaultResourceDescription$4.get(DefaultResourceDescription.java:172)
	at org.eclipse.xtext.resource.impl.DefaultResourceDescription$4.get(DefaultResourceDescription.java:1)
	at org.eclipse.xtext.util.OnChangeEvictingCache.get(OnChangeEvictingCache.java:46)
	at org.eclipse.xtext.resource.impl.DefaultResourceDescription.getLookUp(DefaultResourceDescription.java:167)
	at org.eclipse.xtext.resource.impl.AbstractResourceDescription.getExportedObjects(AbstractResourceDescription.java:32)
	at org.eclipse.xtext.ui.editor.StatefulResourceDescription.copyExportedObjects(StatefulResourceDescription.java:46)
	at org.eclipse.xtext.ui.editor.StatefulResourceDescription.<init>(StatefulResourceDescription.java:42)
	at org.eclipse.xtext.ui.editor.DocumentBasedDirtyResource.copyState(DocumentBasedDirtyResource.java:93)
	at org.eclipse.xtext.ui.editor.DocumentBasedDirtyResource.initiallyProcessResource(DocumentBasedDirtyResource.java:53)
	at org.eclipse.xtext.builder.impl.PersistentDataAwareDirtyResource.initiallyProcessResource(PersistentDataAwareDirtyResource.java:35)
	at org.eclipse.xtext.ui.editor.DocumentBasedDirtyResource$1.process(DocumentBasedDirtyResource.java:40)
	at org.eclipse.xtext.ui.editor.DocumentBasedDirtyResource$1.process(DocumentBasedDirtyResource.java:1)
	at org.eclipse.xtext.util.concurrent.IUnitOfWork$Void.exec(IUnitOfWork.java:36)
	at org.eclipse.xtext.util.concurrent.AbstractReadWriteAcces.readOnly(AbstractReadWriteAcces.java:32)
	at org.eclipse.xtext.ui.editor.model.XtextDocument.readOnly(XtextDocument.java:86)
	at org.eclipse.xtext.ui.editor.DocumentBasedDirtyResource.connect(DocumentBasedDirtyResource.java:36)
	at org.eclipse.xtext.ui.editor.DirtyStateEditorSupport.initDirtyResource(DirtyStateEditorSupport.java:261)
	at org.eclipse.xtext.ui.editor.DirtyStateEditorSupport.initializeDirtyStateSupport(DirtyStateEditorSupport.java:221)
	at org.eclipse.xtext.ui.editor.AbstractDirtyStateAwareEditorCallback.afterCreatePartControl(AbstractDirtyStateAwareEditorCallback.java:32)
	at org.eclipse.xtext.builder.nature.NatureAddingEditorCallback.afterCreatePartControl(NatureAddingEditorCallback.java:29)
	at org.eclipse.xtext.ui.editor.CompoundXtextEditorCallback.afterCreatePartControl(CompoundXtextEditorCallback.java:49)
	at org.eclipse.xtext.ui.editor.XtextEditor.createPartControl(XtextEditor.java:381)
	at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:670)
	at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:465)
	at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
	at org.eclipse.ui.internal.EditorReference.getEditor(EditorReference.java:289)
	at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2945)
	at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2850)
	at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2842)
	at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2793)
	at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2789)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2773)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2764)
	at org.eclipse.ui.ide.IDE.openEditor(IDE.java:651)
	at org.eclipse.ui.ide.IDE.openEditor(IDE.java:610)
	at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:355)
	at org.eclipse.jdt.internal.ui.javaeditor.EditorUtility.openInEditor(EditorUtility.java:164)
	at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:249)
	at org.eclipse.jdt.ui.actions.OpenAction.run(OpenAction.java:228)
	at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:275)
	at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:251)
	at org.eclipse.jdt.internal.ui.packageview.PackageExplorerActionGroup.handleOpen(PackageExplorerActionGroup.java:376)
	at org.eclipse.jdt.internal.ui.packageview.PackageExplorerPart$4.open(PackageExplorerPart.java:538)
	at org.eclipse.ui.OpenAndLinkWithEditorHelper$InternalListener.open(OpenAndLinkWithEditorHelper.java:48)
	at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:866)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
	at org.eclipse.jface.viewers.StructuredViewer.fireOpen(StructuredViewer.java:864)
	at org.eclipse.jface.viewers.StructuredViewer.handleOpen(StructuredViewer.java:1152)
	at org.eclipse.jface.viewers.StructuredViewer$6.handleOpen(StructuredViewer.java:1256)
	at org.eclipse.jface.util.OpenStrategy.fireOpenEvent(OpenStrategy.java:275)
	at org.eclipse.jface.util.OpenStrategy.access$2(OpenStrategy.java:269)
	at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:309)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
	at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2696)
	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2660)
	at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2494)
	at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:674)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:667)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1386)


The problem is the ImportedNamespaceAwareLocalScopeProvider
that needs the name it is actually used to be calculated itself.



Reproducible: Always

Comment 1 Sebastian Zarnekow

2011-08-08 11:25:02 EDT

We won't remove this assertion since it reveals actual bugs (like relying on cross references to compute a name).

Comment 2 Christian Dietrich

2011-08-08 11:36:57 EDT

so that is the intended way to workarround this?

using NodeModelUtils to read the Xtext?

Comment 3 Sebastian Zarnekow

2011-08-08 11:47:41 EDT

(In reply to comment #2)
> so that is the intended way to workarround this?
> 
> using NodeModelUtils to read the Xtext?

That would be only a partial solution since the resolved entity may have a longer qualified name due to imports etc. but it may work in some cases. Another option would be to customize the scoping for instances of 'Usage' to make sure that their qualified name is computed locally.