Description Theodora Yeung 2005-10-06 14:21:46 EDT

Stack trace:
java.lang.NullPointerException
	at org.eclipse.jdt.internal.compiler.ast.FieldReference.getConstantFor
(FieldReference.java:408)
	at 
org.eclipse.jdt.internal.compiler.ast.QualifiedNameReference.getOtherFieldBindi
ngs(QualifiedNameReference.java:657)
	at 
org.eclipse.jdt.internal.compiler.ast.QualifiedNameReference.resolveType
(QualifiedNameReference.java:880)
	at 
org.eclipse.jdt.internal.compiler.ast.MemberValuePair.resolveTypeExpecting
(MemberValuePair.java:70)
	at org.eclipse.jdt.internal.compiler.ast.Annotation.resolveType
(Annotation.java:255)
	at org.eclipse.jdt.internal.compiler.ast.ASTNode.resolveAnnotations
(ASTNode.java:466)
	at 
org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding.getAnnotationTagBits
(SourceTypeBinding.java:720)
	at 
org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding.faultInTypesForField
sAndMethods(SourceTypeBinding.java:618)
	at 
org.eclipse.jdt.internal.compiler.lookup.CompilationUnitScope.faultInTypes
(CompilationUnitScope.java:420)
	at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve
(CompilationUnitResolver.java:721)
	at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve
(CompilationUnitResolver.java:460)
	at org.eclipse.jdt.core.dom.ASTParser.createASTs(ASTParser.java:664)
	at fp.MyAnnoProcessor.process(MyAnnoProcessor.java:45)
	at 
org.eclipse.jdt.apt.core.internal.APTDispatchRunnable.runAPTInFileBasedMode
(APTDispatchRunnable.java:309)
	at org.eclipse.jdt.apt.core.internal.APTDispatchRunnable.runAPT
(APTDispatchRunnable.java:536)
	at org.eclipse.jdt.apt.core.internal.APTDispatchRunnable.runAPT
(APTDispatchRunnable.java:442)
	at org.eclipse.jdt.apt.core.internal.APTDispatchRunnable.run
(APTDispatchRunnable.java:192)
	at org.eclipse.jdt.apt.core.internal.APTDispatch.runAPT
(APTDispatch.java:99)
	at org.eclipse.jdt.apt.core.internal.APTDispatch.runAPTDuringReconcile
(APTDispatch.java:58)
	at 
org.eclipse.jdt.apt.core.internal.AptCompilationParticipant.preReconcileNotify
(AptCompilationParticipant.java:180)
	at org.eclipse.jdt.apt.core.internal.AptCompilationParticipant.notify
(AptCompilationParticipant.java:88)
	at 
org.eclipse.jdt.internal.core.ReconcileWorkingCopyOperation.notifyCompilationPa
rticipants(ReconcileWorkingCopyOperation.java:144)
	at 
org.eclipse.jdt.internal.core.ReconcileWorkingCopyOperation.executeOperation
(ReconcileWorkingCopyOperation.java:58)
	at org.eclipse.jdt.internal.core.JavaModelOperation.run
(JavaModelOperation.java:718)
	at org.eclipse.jdt.internal.core.JavaModelOperation.runOperation
(JavaModelOperation.java:777)
	at org.eclipse.jdt.internal.core.CompilationUnit.reconcile
(CompilationUnit.java:1081)
	at org.eclipse.jdt.internal.ui.text.java.JavaReconcilingStrategy$1.run
(JavaReconcilingStrategy.java:98)
	at org.eclipse.core.internal.runtime.InternalPlatform.run
(InternalPlatform.java:1044)
	at org.eclipse.core.runtime.Platform.run(Platform.java:783)
	at 
org.eclipse.jdt.internal.ui.text.java.JavaReconcilingStrategy.reconcile
(JavaReconcilingStrategy.java:82)
	at 
org.eclipse.jdt.internal.ui.text.java.JavaReconcilingStrategy.reconcile
(JavaReconcilingStrategy.java:147)
	at 
org.eclipse.jdt.internal.ui.text.CompositeReconcilingStrategy.reconcile
(CompositeReconcilingStrategy.java:86)
	at 
org.eclipse.jdt.internal.ui.text.JavaCompositeReconcilingStrategy.reconcile
(JavaCompositeReconcilingStrategy.java:94)
	at org.eclipse.jface.text.reconciler.MonoReconciler.process
(MonoReconciler.java:75)
	at org.eclipse.jdt.internal.ui.text.JavaReconciler.process
(JavaReconciler.java:339)
	at 
org.eclipse.jface.text.reconciler.AbstractReconciler$BackgroundThread.run
(AbstractReconciler.java:204)


Repro: 
Create a java project with the following three java files.
package pkg;
RefAnnoAndClassWithAnno.java :
public class RefMyAnnoAndClassWithAnno {
	final Class anno = MyAnno.class;
	final Class withAnno = ClassWithAnnotation.class;	
}

MyAnno.java :
public @interface MyAnno {	
	public enum EnumColor{
		BLUE, RED, WHITE;
	}	
	EnumColor aEnum();
}

ClassWithAnnotation.java:
package pkg;
import pkg.MyAnno.EnumColor;

@MyAnno(aEnum = EnumColor.BLUE)
public class ClassWithAnnotation {}


If you invoke the following code against the project you just created, you 
will get the NPE.

/* Ask for type "pkg.RefMyAnnoAndClassWithAnno" through 
 DOMParser.createASTs() passing in only the binding key and no compilation 
unit*/
void process(){
    class BindingRequestor extends ASTRequestor{}
    String key = BindingKey.createTypeBindingKey
("pkg.RefMyAnnoAndClassWithAnno");
    final ASTParser parser = ASTParser.newParser(AST.JLS3);
    final BindingRequestor requestor = new BindingRequestor();
    parser.setResolveBindings(true);		
    parser.setProject(/*the java project with the three java files*/);
    parser.createASTs(new ICompilationUnit[0], new String[]{key}, requestor, 
null);
}

On my machine, i used APT to dispatch to an annotation processor that runs the 
above process() code that's why the stack trace contains APT in it. APT does 
not do anything that would influence the behavior of the bug. 
(Let me know if you need anything else to repro the problem.)

It does not matter whether the process() code is invoked during reconcile or 
build. 

What I observed:
1) CompilationUnitResolver.resolve(ICompilationUnit[], String[], ASTRequestor 
astRequestor, int, Map, WorkingCopyOwner) calls Compiler.process(..) and 
resolve type "pkg.RefMyAnnoAndClassWithAnno".
2) Compiler.process() puts "pkg.MyAnno" and "pkg.ClassWithAnnotation" on the 
queue (unitsToProcess) to be processed.
3) resolution of "pkg.RefMyAnnoAndClassWithAnno" completes, reports the 
binding. Then cuts the reference to the AST for the type.
4) calls faultInTypes() on "pkg.MyAnno". At completion, cuts the AST.
5) calls faultInTypes() on "pkg.ClassWithAnnotation".
6) Since "pkg.ClassWithAnnotation" has an annotation, then the compiler go 
resolve the annotations. 
7) NPE occurs since the annotation reference an enum constant in "pkg.MyAnno" 
and the constant has never been resolved and the AST for it is already cut.