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Home » Modeling » TMF (Xtext) » dangling reference error in XBlockExpression when accessing properties(define JvmType of property programmatically)
icon5.gif  dangling reference error in XBlockExpression when accessing properties [message #755124] Mon, 07 November 2011 13:26 Go to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Hallo,

I am new to Xtext and have a problem with my DSL. It is derived from the domainmodel example (using xtext 2.0.1):
...
Entity:
	{Entity}
	abstract?='abstract'? 'entity' name=ValidID ('extends' superType=[Entity|QualifiedName])? '{'
		(properties+=Property ("," properties+=Property)*)?
		methods+=Method*
	'}';
Property:
	ToOneAssociation | ... ;
ToOneAssociation:
	{ToOneAssociation}
	(protected?='#'|'-')?
	name=ValidID ':' access=AccessConfig? 'ref'
	fromMany?='*'?
	entity=[Entity|QualifiedName]
	('backref' backReference=[Property|ValidID])?
	notNull?='notNull'?
	unique?='unique'?
	validator=[Validator|QualifiedName]?;
...


Entities and field types with getters and setters are mapped to JvmTypes in an IJvmModelInferrer like this:
	@Inject extension IJvmModelAssociator jvmModelAssociator
	@Inject TypeReferences types
	@Inject extension IJvmModelAssociations associations
	...
	def transform(Entity entity) {
		val jvmType = typesFactory.createJvmGenericType

		jvmType.simpleName = entity.name
		jvmType.packageName = entity.packageName
		jvmType.visibility = JvmVisibility::PUBLIC

		entity.associatePrimary(jvmType)
		
		for (p : entity.properties)
			associateProperty(p, jvmType)
		
		newArrayList(jvmType as JvmDeclaredType)
	}

	def dispatch associateProperty(ToOneAssociation p, JvmGenericType jvmType) {
		transformProperty(property, jvmTypeRef(property.entity), jvmType)
	}
	... {more dispatched associateProperty methods} ...

	def void transformProperty(Property property, JvmTypeReference fieldType, JvmGenericType jvmType) {
		val jvmField = typesFactory.createJvmField
		val access = property.access
		
		jvmField.simpleName = property.name
		jvmField.type = cloneWithProxies(fieldType)
		jvmField.visibility = jvmVisibility(property)
		jvmType.members += jvmField
		
		property.associatePrimary(jvmField)
		
		if (access == null || access.getter) {
			val jvmGetter = typesFactory.createJvmOperation
		
			jvmGetter.simpleName = "get" + property.name.toFirstUpper
			jvmGetter.returnType = cloneWithProxies(fieldType)
			jvmGetter.visibility = JvmVisibility::PUBLIC
			jvmType.members += jvmGetter
			
			property.associatePrimary(jvmGetter)
		}
		
		if (access == null || access.setter) {
			val jvmSetter = typesFactory.createJvmOperation
			val parameter = typesFactory.createJvmFormalParameter
		
			parameter.name = property.name.toFirstUpper
			parameter.parameterType = cloneWithProxies(fieldType)
			jvmSetter.simpleName = "set" + property.name.toFirstUpper
			jvmSetter.visibility = JvmVisibility::PUBLIC
			jvmSetter.parameters += parameter
			jvmType.members += jvmSetter
			
			property.associatePrimary(jvmSetter)
		}
	}

	def JvmTypeReference jvmTypeRef(Entity type) {
		var jvmType = type.jvmElements.filter(typeof(JvmType)).head
		
		if (jvmType == null) {
			transform(type)
			
			jvmType = type.jvmElements.filter(typeof(JvmType)).head
			
			if (jvmType == null)
				throw new IllegalArgumentException("Cannot resolve type " + type.name)
		}
		
		types.createTypeRef(jvmType)
	}

The following example code with my DSL shows what I want to do and contains my problem:
package test {
	entity A {
		created : java.util.Date,
		propertyToB : ref B
		
		testOp() : void {
			propertyToB.[color=red]propertyToA[/color].created.^time
		}
	}
	
	entity B {
		propertyToA : ref A
	}
}

I can access every property with autocompletion. But afterwards Eclipse marks the nested property access propertyToA as error but not the propertyB access before and not the following java.util.Date property which type is included by the xbase grammar rule JvmTypeReference.
The error says:
Quote:
The feature 'feature' of 'org.eclipse.xtext.xbase.impl.XMemberFeatureCallImplCustom@2c405913{platform:/resource/Testxy/src/SampleEntities.crudsl#/0/@elements.3/@elements.1/@methods.0/@body/@expressions.1/@memberCallTarget}'
contains a dangling reference 'org.eclipse.xtext.common.types.impl.JvmOperationImpl@5b6a3d73{#///@members.7}'
and eclipse throws a NullPointerException at org.eclipse.xtext.resource.IGlobalServiceProvider$ResourceServiceProviderImpl.findService(IGlobalServiceProvider.java:59)


I've read that every persistent element in an EMF model has to be registered in Resource.contents to be indexed. Makes sense. Although it says that xbase registers its used JvmTypes by itself in the model root I tried to register every entity's JvmType in the transform(entity) method by writing
entity.eResource.contents.add(jvmType)

This makes my access error disappear but comes up with an eclipse exception with dialog window:
Quote:
!MESSAGE org.eclipse.xtext.linking.lazy.LazyLinkingResource - resolution of uriFragment 'xtextLink_::0.0.3.1.2.4.0.6::1::/0' failed.

!STACK 0
org.eclipse.emf.common.util.BasicEList$BasicIndexOutOfBoundsException: index=3, size=0
at org.eclipse.emf.common.util.BasicEList.get(BasicEList.java:352)
at org.eclipse.xtext.linking.lazy.LazyURIEncoder.resolveShortFragment(LazyURIEncoder.java:100)
at org.eclipse.xtext.linking.lazy.LazyURIEncoder.decode(LazyURIEncoder.java:80)
at org.eclipse.xtext.linking.lazy.LazyLinkingResource.getEObject(LazyLinkingResource.java:157)
at org.eclipse.xtext.linking.lazy.LazyLinkingResource.resolveLazyCrossReference(LazyLinkingResource.java:139)
at org.eclipse.xtext.linking.lazy.LazyLinkingResource.resolveLazyCrossReferences(LazyLinkingResource.java:103)
at org.eclipse.xtext.EcoreUtil2.resolveLazyCrossReferences(EcoreUtil2.java:417)
at org.eclipse.xtext.validation.ResourceValidatorImpl.resolveProxies(ResourceValidatorImpl.java:127)
at org.eclipse.xtext.validation.ResourceValidatorImpl.validate(ResourceValidatorImpl.java:62)
at org.eclipse.xtext.ui.editor.validation.ValidationJob$1.exec(ValidationJob.java:79)
at org.eclipse.xtext.ui.editor.validation.ValidationJob$1.exec(ValidationJob.java:1)
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.validation.ValidationJob.createIssues(ValidationJob.java:75)
at org.eclipse.xtext.ui.editor.validation.ValidationJob.run(ValidationJob.java:64)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)


HELP, PLEASE!

Simply, I want to access properties with JvmTypes of my entities in a XBlockExpression having defined the JvmType of every property programmatically because I do not want users create associations to other java types than the defined entities.

regards,
Max

[Updated on: Tue, 08 November 2011 03:46]

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Re: dangling reference error in XBlockExpression when accessing properties [message #755506 is a reply to message #755124] Tue, 08 November 2011 16:42 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
I am stuck on this problem!!!
I do not understand this.

My problem in a few words:
I want to have a grammar similar to that from the domain model example but without declaration of specific java types. Instead I want to define the types programmatically. In case of an entity reference I use the JvmGenericType declared for that entity but in the DSL the grammar rule for that is not [JvmTypeReference] but ref (*) [Entity]. Lists shall also not be declared as explicit java types in the DSL but as keywords list or set with the optional keyword * afterwards marking that property as manyToMany association. Inside the IJvmModelInferrer instance I declare properties with these keywords as JvmTypeReference of java.util.List/Set. With such limitations I want to be able to define the grammar context free but dependent of special types.
Shorter: I want to have a clear context free separation of *toMany/*toOne associations and normal attributes without analysing the given JvmTypeReferences and collection types.

Help, please!!!

regards,
Max

[Updated on: Tue, 08 November 2011 16:42]

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Re: dangling reference error in XBlockExpression when accessing properties [message #755548 is a reply to message #755506] Tue, 08 November 2011 19:08 Go to previous messageGo to next message
Sebastian Zarnekow is currently offline Sebastian ZarnekowFriend
Messages: 3108
Registered: July 2009
Senior Member
Hi Max,

please make sure that the XbaseLazyLinker is bound for your language.

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com

On 08.11.11 17:42, Max wrote:
> I am stuck on this problem!!!
> I do not understand this.
>
> My problem in a few words:
> I want have a grammar similar to that from the domain model example but
> without declaration of specific java types. Instead I want to define the
> types programmatically. In case of an entity reference I use the
> JvmGenericType declared for that entity but in the DSL the grammar rule
> for that is not [JvmTypeReference] but ref (*) [Entity]. Lists shall
> also not be declared as explicit java types in the DSL but as keywords
> list or set with the optional keyword * afterwards marking that property
> as manyToMany association. Inside the IJvmModelInferrer instance I
> declare properties with these keywords as JvmTypeReference of
> java.util.List/Set. With such limitations I want to be able to define
> the grammar context free but dependent of special types.
> Shorter: I want to have a clear context free separation of
> *toMany/*toOne associations and normal attributes without analysing the
> given JvmTypeReferences and collection types.
>
> Help, please!!!
>
> regards,
> Max
Re: dangling reference error in XBlockExpression when accessing properties [message #755569 is a reply to message #755548] Tue, 08 November 2011 20:08 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Hey,

My grammar extends org.eclipse.xtext.xbase.Xbase.

Included in GenerateCrudsl.mwe2:
fragment = xbase.XbaseGeneratorFragment {}

For this reason generated in AbstractCrudslRuntime
public Class<? extends org.eclipse.xtext.linking.ILinker> bindILinker() {
	return org.eclipse.xtext.xbase.jvmmodel.JvmModelXbaseLazyLinker.class;
}


Any other idea?

The example dsl code once again:
package test {
	entity A {
		propertyToB : ref B
		
		testOp() : void {
			propertyToB.propertyToA
		}
	}
	
	entity B {
		propertyToA : ref A
	}
}

In testOp(): Access to propertyToB is valid. Access to propertyToA is marked as error:
The feature 'feature' of 'org.eclipse.xtext.xbase.impl.XMemberFeatureCallImplCustom@7ed655a8{platform:/resource/Testxy/src/SampleEntities.crudsl#/0/@elements.3/@elements.0/@methods.0/@body/@expressions.1/@memberCallTarget/@memberCallTarget}'
   contains a dangling reference 'org.eclipse.xtext.common.types.impl.JvmOperationImpl@6a85a2b6{#///@members.4}'


regards,
Max

[Updated on: Tue, 08 November 2011 20:16]

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Re: dangling reference error in XBlockExpression when accessing properties [message #755574 is a reply to message #755569] Tue, 08 November 2011 20:28 Go to previous messageGo to next message
Sebastian Zarnekow is currently offline Sebastian ZarnekowFriend
Messages: 3108
Registered: July 2009
Senior Member
Hi Max,

please make sure that you invoke disassociate on the root element of
your resource prior to adding new associations.

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com


On 08.11.11 21:08, Max wrote:
> Hey,
> My grammar extends org.eclipse.xtext.xbase.Xbase.
>
> Included in GenerateMyLang.mwe2:
> fragment = xbase.XbaseGeneratorFragment {}
>
> For this reason generated in AbstractMyLanguageRuntime
> public Class<? extends org.eclipse.xtext.linking.ILinker> bindILinker() {
> return org.eclipse.xtext.xbase.jvmmodel.JvmModelXbaseLazyLinker.class;
> }
>
> Any other idea?
>
> regards,
> Max
Re: dangling reference error in XBlockExpression when accessing properties [message #755589 is a reply to message #755574] Tue, 08 November 2011 21:20 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Hey Sebastian,

I call sourceObj.disassociate() once before I start mapping like in domainmodel example:
	override List<? extends JvmDeclaredType> inferJvmModel(EObject sourceObject) {
		sourceObject.disassociate()
		transform(sourceObject).toList()
	}
	
	def dispatch Iterable<JvmDeclaredType> transform(Crudsl model) {
		model.elements.map(e | transform(e)).flatten
	}
	 
	def dispatch Iterable<JvmDeclaredType> transform(PackageDeclaration packageDecl) {
		packageDecl.elements.map(e | transform(e)).flatten
	}
	
	def dispatch Iterable<JvmDeclaredType> transform(Entity entity) {...


Entities and Properties are mapped via associatePrimary() as you can see in my first post.

Another idea? Confused

The error may rely on the jvmTypeRef() method (see #1)?

regards,
Max

[Updated on: Wed, 09 November 2011 18:46]

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Re: dangling reference error in XBlockExpression when accessing properties [message #755897 is a reply to message #755589] Thu, 10 November 2011 05:38 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Now I realised that Xtext 2.1 is already available using the update site. I had installed Xtext 2.0.1 from eclipse marketplace before that.
With Xtext 2.1 everything works. Great!
Thanks for your help, Sebastian.

The only thing is I iterate over the whole grammar twice register types first and their elements afterwards to create bidirectional references.
Is there a better approach?
I expected the initializer closures of the JvmTypesBuilder.toClass() method calls beeing called after all elements are mapped to JvmTypes but it is called directly after every single type mapping. Sad

regards,
Max

[Updated on: Thu, 10 November 2011 06:01]

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Re: dangling reference error in XBlockExpression when accessing properties [message #755902 is a reply to message #755897] Thu, 10 November 2011 06:27 Go to previous messageGo to next message
Sebastian Zarnekow is currently offline Sebastian ZarnekowFriend
Messages: 3108
Registered: July 2009
Senior Member
On 10.11.11 06:38, Max wrote:
> Now I realised that Xtext 2.1 is already available using the update
> site. I had installed Xtext 2.0.1 from eclipse marketplace before that.
> With Xtext 2.1 everything works. Great!
>
> The only thing is I iterate over the whole grammar twice register types
> first and their elements afterwards to create bidirectional references.
> Is there a better approach?
> I expected the initializer closures of the JvmTypesBuilder.toClass()
> method calls beeing called after every element is mapped to a JvmType
> but it is called directly after every single type mapping. :(
> regards,
> Max

Hi Max,

you may want to use create functions for that purpose:
http://www.eclipse.org/Xtext/documentation/2_1_0/02-Xtend_Classes_Functions.php#CreateFunctions

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com
Re: dangling reference error in XBlockExpression when accessing properties [message #756069 is a reply to message #755902] Thu, 10 November 2011 18:42 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Thanks a lot!!! Very good approach.

But there seems to be a problem with the scope in the java code generator of Xtend:
class CrudslJvmModelInferrer extends AbstractModelInferrer {

	@Inject extension JvmTypesBuilder

	@Inject extension IQualifiedNameProvider

	def dispatch infer(Type type, IAcceptor<JvmDeclaredType> acceptor, boolean prelinkingPhase) {
		acceptor.accept(type.toJvmType())
	}
	
	def create jvmType: type.toClass(type.fullyQualifiedName, null) toJvmType(Type type) {
		... {initialize: associate type's fields with jvmType's fields} ...
	}
	
	...
}

generates:
  public JvmGenericType toJvmType(final Type type) {
    final ArrayList<?>_cacheKey = CollectionLiterals.newArrayList(type);
    final JvmGenericType _result;
    synchronized (_createCache_toJvmType) {
      if (_createCache_toJvmType.containsKey(_cacheKey)) {
        return _createCache_toJvmType.get(_cacheKey);
      }
->    CrudslJvmModelInferrer _CrudslJvmModelInferrer = CrudslJvmModelInferrer;
->    CrudslJvmModelInferrer _CrudslJvmModelInferrer_1 = CrudslJvmModelInferrer;
      QualifiedName _fullyQualifiedName = _CrudslJvmModelInferrer_1._iQualifiedNameProvider.getFullyQualifiedName(type);
      JvmGenericType _class = _CrudslJvmModelInferrer._jvmTypesBuilder.toClass(type, _fullyQualifiedName, null);
      _result = _class;
      _createCache_toJvmType.put(_cacheKey, _result);
    }
    _init_toJvmType(_result, type);
    return _result;
  }

"CrudslJvmModelInferrer _CrudslJvmModelInferrer = CrudslJvmModelInferrer;" is an error. It should be
"CrudslJvmModelInferrer _CrudslJvmModelInferrer = this;" and is not neccessary. "this" could also be used, directly.

Somehow, I cannot access "this"/extensions in the first expression of the create function.

Is it a bug or a feature?

regards,
Max

[Updated on: Thu, 10 November 2011 20:55]

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Re: dangling reference error in XBlockExpression when accessing properties [message #756093 is a reply to message #756069] Thu, 10 November 2011 20:37 Go to previous messageGo to next message
Sebastian Zarnekow is currently offline Sebastian ZarnekowFriend
Messages: 3108
Registered: July 2009
Senior Member
Max,

thanks for the report. This was already fixed for 2.1.1 which will be
available tomorrow.

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com


On 10.11.11 19:42, Max wrote:
> Thanks a lot!!! Very good approach. But there seems to be a problem with
> the scope in the java code generator of Xtend:
> class CrudslJvmModelInferrer extends AbstractModelInferrer {
>
> @Inject extension JvmTypesBuilder
>
> @Inject extension IQualifiedNameProvider
>
> def dispatch infer(Type type, IAcceptor<JvmDeclaredType> acceptor,
> boolean prelinkingPhase) {
> acceptor.accept(type.toJvmType())
> }
>
> def create jvmType: type.toClass(type.fullyQualifiedName, null)
> toJvmType(Type type) {
> ... {initialize} ...
> }
>
> ...
> }
> generates:
> public JvmGenericType toJvmType(final Type type) {
> final ArrayList<?>_cacheKey = CollectionLiterals.newArrayList(type);
> final JvmGenericType _result;
> synchronized (_createCache_toJvmType) {
> if (_createCache_toJvmType.containsKey(_cacheKey)) {
> return _createCache_toJvmType.get(_cacheKey);
> }
> CrudslJvmModelInferrer _CrudslJvmModelInferrer = CrudslJvmModelInferrer;
> CrudslJvmModelInferrer _CrudslJvmModelInferrer_1 = CrudslJvmModelInferrer;
> QualifiedName _fullyQualifiedName =
> _CrudslJvmModelInferrer_1._iQualifiedNameProvider.getFullyQualifiedName(type);
>
> JvmGenericType _class =
> _CrudslJvmModelInferrer._jvmTypesBuilder.toClass(type,
> _fullyQualifiedName, null);
> _result = _class;
> _createCache_toJvmType.put(_cacheKey, _result);
> }
> _init_toJvmType(_result, type);
> return _result;
> }
> "CrudslJvmModelInferrer _CrudslJvmModelInferrer =
> CrudslJvmModelInferrer;" is an error. It should be
> "CrudslJvmModelInferrer _CrudslJvmModelInferrer = this;" and is not
> neccessary. "this" could also be used, directly.
>
> Is this a bug or do I not understand sth?
>
> regards,
> Max
Re: dangling reference error in XBlockExpression when accessing properties [message #756098 is a reply to message #756093] Thu, 10 November 2011 21:01 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Great, just in time!!! Laughing
Re: dangling reference error in XBlockExpression when accessing properties [message #756320 is a reply to message #756098] Fri, 11 November 2011 23:22 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Hey,

now I've installed Xtext 2.1.0 release + Xtext 2.1.1 nightly build but wiring bidirectional references does not work with this create function. It throws a StackOverflowError.
Xtend:
class CrudslJvmModelInferrer extends AbstractModelInferrer {

	@Inject extension JvmTypesBuilder
	@Inject extension IQualifiedNameProvider	
	@Inject extension TypeReferences types

	def dispatch infer(Type type, IAcceptor<JvmDeclaredType> acceptor, boolean prelinkingPhase) {
		acceptor.accept(type.jvmType)
	}
	
	def create jvmType: type.toClass(type.fullyQualifiedName, null) jvmType(Type type) {
   		for (p : entity.properties) {
   			val type = p.jvmTypeRef(jvmType)
   			
			jvmType.members += p.toField(p.name, type)
	
			if (p.access == null || p.access.getter)
				jvmType.members += p.toGetter(p.name, type)
			
   			if (p.access == null || p.access.setter)
				jvmType.members += p.toSetter(p.name, type)
		}
	}

	def dispatch JvmTypeReference jvmTypeRef(ToOneAssociation p, JvmGenericType jvmType) {
		p.entity.jvmType.createTypeRef()
	}

	... {more dispatched jvmTypeRef() methods} ...
}

generated java:
...
  public JvmGenericType jvmType(final Type type) {
    final ArrayList<?>_cacheKey = CollectionLiterals.newArrayList(type);
    final JvmGenericType _result;
    synchronized (_createCache_jvmType) {
      if (_createCache_jvmType.containsKey(_cacheKey)) {
        return _createCache_jvmType.get(_cacheKey);
      }
      QualifiedName _fullyQualifiedName = this._iQualifiedNameProvider.getFullyQualifiedName(type);
      JvmGenericType _class = this._jvmTypesBuilder.toClass(type, _fullyQualifiedName, null);
      _result = _class;
      _createCache_jvmType.put(_cacheKey, _result);
    }
    _init_jvmType(_result, type);
    return _result;
  }
...

Here the _init_jvmType() method is called directly after instantiating a new object. It doesn't work because initialization requires existing types, which are not yet instantiated. I thought somehow the create function's initializer is called after every element is instantiated?!
In the documentation it seems to be possible to map bidirectional references like this: http://www.eclipse.org/Xtext/documentation/2_1_0/02-Xtend_Classes_Functions.php#CreateFunctions.

What am I doing wrong?

regards,
Max
Re: dangling reference error in XBlockExpression when accessing properties [message #756322 is a reply to message #756320] Fri, 11 November 2011 23:43 Go to previous messageGo to next message
Christian Dietrich is currently offline Christian DietrichFriend
Messages: 13667
Registered: July 2009
Senior Member
Hi,

i guess you have a missunderstanding what a create function does:

(1) it looks up the parameter in a cache and if it finds something then this something is return
(2) else it creates a new instance using the "factory" expression
(3) then it calls the "initializer" expression
(4) the result is stored to the cache.

=> you can call the conversion to jvm class at every place you need it, so matter if it is at the for loop
when you iterate over all entities, nor if you want to get the jvm type of the references to another entity
since the caching is done before calling the initializer expression there should be no problem with an endless loop
/ stackoverflow.

=> is it really the jvmType function that causes the stackoverflow?

~Christian


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[Updated on: Fri, 11 November 2011 23:45]

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Re: dangling reference error in XBlockExpression when accessing properties [message #756325 is a reply to message #756322] Sat, 12 November 2011 01:24 Go to previous messageGo to next message
Max Goltzsche is currently offline Max GoltzscheFriend
Messages: 40
Registered: November 2011
Member
Thank you for your answer.
You're right: The jvmType method works well but there seems to be a problem with the result of a create method passed to acceptor.accept(). It may be a proxy because my test eclipse instance has the StackOverflow while resolving proxies (stacktrace only visible when shutting eclipse down for some reason else I only get a window with that short error information):
Error while informing user about event loop exception:
java.lang.StackOverflowError
	at org.eclipse.xtext.common.types.impl.JvmDeclaredTypeImpl.getMembers(JvmDeclaredTypeImpl.java:285)
	at org.eclipse.xtext.common.types.impl.JvmDeclaredTypeImpl.eGet(JvmDeclaredTypeImpl.java:489)
	at org.eclipse.xtext.common.types.impl.JvmGenericTypeImpl.eGet(JvmGenericTypeImpl.java:232)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eGet(BasicEObjectImpl.java:1021)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eGet(BasicEObjectImpl.java:1013)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eObjectForURIFragmentSegment(BasicEObjectImpl.java:533)
	at org.eclipse.emf.ecore.resource.impl.ResourceImpl.getEObject(ResourceImpl.java:780)
	at org.eclipse.emf.ecore.resource.impl.ResourceImpl.getEObject(ResourceImpl.java:756)
	at org.eclipse.xtext.resource.XtextResource.access$1(XtextResource.java:1)
	at org.eclipse.xtext.resource.XtextResource$1.getEObject(XtextResource.java:102)
	at org.eclipse.xtext.resource.DefaultFragmentProvider.getEObject(DefaultFragmentProvider.java:26)
	at org.eclipse.xtext.resource.XtextResource.getEObject(XtextResource.java:286)
	at org.eclipse.xtext.linking.lazy.LazyLinkingResource.getEObject(LazyLinkingResource.java:211)
	at org.eclipse.xtext.xbase.resource.XbaseResource.access$0(XbaseResource.java:1)
	at org.eclipse.xtext.xbase.resource.XbaseResource$2.exec(XbaseResource.java:227)
	at org.eclipse.xtext.xbase.resource.XbaseResource$2.exec(XbaseResource.java:1)
	at org.eclipse.xtext.util.OnChangeEvictingCache.execWithoutCacheClear(OnChangeEvictingCache.java:121)
	at org.eclipse.xtext.xbase.resource.XbaseResource.getEObject(XbaseResource.java:225)
	at org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.getEObject(ResourceSetImpl.java:219)
	at org.eclipse.emf.ecore.util.EcoreUtil.resolve(EcoreUtil.java:203)
	at org.eclipse.emf.ecore.util.EcoreUtil.resolve(EcoreUtil.java:263)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eResolveProxy(BasicEObjectImpl.java:1483)
	at org.eclipse.emf.ecore.util.EcoreEList.resolveProxy(EcoreEList.java:212)
	at org.eclipse.emf.ecore.util.EcoreEList.resolve(EcoreEList.java:167)
	at org.eclipse.emf.ecore.util.EObjectContainmentWithInverseEList$Resolving.resolve(EObjectContainmentWithInverseEList.java:111)
	at org.eclipse.emf.common.util.BasicEList.get(BasicEList.java:354)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eObjectForURIFragmentSegment(BasicEObjectImpl.java:545)
	at org.eclipse.emf.ecore.resource.impl.ResourceImpl.getEObject(ResourceImpl.java:780)
	at org.eclipse.emf.ecore.resource.impl.ResourceImpl.getEObject(ResourceImpl.java:756)
	at org.eclipse.xtext.resource.XtextResource.access$1(XtextResource.java:1)
	at org.eclipse.xtext.resource.XtextResource$1.getEObject(XtextResource.java:102)
	at org.eclipse.xtext.resource.DefaultFragmentProvider.getEObject(DefaultFragmentProvider.java:26)
	at org.eclipse.xtext.resource.XtextResource.getEObject(XtextResource.java:286)
	at org.eclipse.xtext.linking.lazy.LazyLinkingResource.getEObject(LazyLinkingResource.java:211)
	at org.eclipse.xtext.xbase.resource.XbaseResource.access$0(XbaseResource.java:1)
	at org.eclipse.xtext.xbase.resource.XbaseResource$2.exec(XbaseResource.java:227)
	at org.eclipse.xtext.xbase.resource.XbaseResource$2.exec(XbaseResource.java:1)
	at org.eclipse.xtext.util.OnChangeEvictingCache.execWithoutCacheClear
...


works:
	def dispatch void infer(Type type, IAcceptor<JvmDeclaredType> acceptor, boolean prelinkingPhase) {
		acceptor.accept(type.toClass(type.fullyQualifiedName, null))
	}

works:
	def dispatch void infer(Type type, IAcceptor<JvmDeclaredType> acceptor, boolean prelinkingPhase) {
		type.jvmType
	}

results in the exception above:
	def dispatch void infer(Type type, IAcceptor<JvmDeclaredType> acceptor, boolean prelinkingPhase) {
		acceptor.accept(type.jvmType)
	}

	def create jvmType: type.toClass(type.fullyQualifiedName, null) jvmType(Type type) {

	}


This is weird.

regards,
Max

[Updated on: Sat, 12 November 2011 01:32]

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Re: dangling reference error in XBlockExpression when accessing properties [message #871322 is a reply to message #755589] Fri, 11 May 2012 23:11 Go to previous message
Brad Riching is currently offline Brad RichingFriend
Messages: 20
Registered: May 2012
Junior Member
Max, where does this code reside? I tried extending AbstractModelInferrer but there doesn't appear to be a method signature "inferJvmModel" that I can override. Perhaps it is because I'm using Xtext 2.2. I too am having the same problem with dangling references through hierarchical path references when the path traverses an entity in the currently-being-edited (dirty) file.

Best wishes,

Brad


Max wrote on Tue, 08 November 2011 16:20
Hey Sebastian,

I call sourceObj.disassociate() once before I start mapping like in domainmodel example:
	override List<? extends JvmDeclaredType> inferJvmModel(EObject sourceObject) {
		sourceObject.disassociate()
		transform(sourceObject).toList()
	}
	
	def dispatch Iterable<JvmDeclaredType> transform(Crudsl model) {
		model.elements.map(e | transform(e)).flatten
	}
	 
	def dispatch Iterable<JvmDeclaredType> transform(PackageDeclaration packageDecl) {
		packageDecl.elements.map(e | transform(e)).flatten
	}
	
	def dispatch Iterable<JvmDeclaredType> transform(Entity entity) {...


Entities and Properties are mapped via associatePrimary() as you can see in my first post.

Another idea? Confused

The error may rely on the jvmTypeRef() method (see #1)?

regards,
Max

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