Description Olivier Demeijer 2021-12-28 09:05:10 EST

Hi,

What steps will reproduce the problem?
1. Open a Maven project with some lambda
2. Watch it fails while compiling, randomly on one of the class where there is at least a lambda

I have this very same problem since at least 2021-06, and have no idea how to fix that.
Way to fix it : even in a class containing more than one method using lambda, the one that causes the compilation failure seems to always be the last one. Within the method, if i convert the lambda to "good old java code", class compiles, and no other compilation error pops up, no matter the size of the project.

Olivier

-- Error Details --
Date: Tue Dec 28 14:55:50 CET 2021
Message: Error in JDT Core during AST creation
Severity: Error
Product: Eclipse IDE 4.22.0.20211202-1200 (org.eclipse.epp.package.java.product)
Plugin: org.eclipse.jdt.core.manipulation
Session Data:
eclipse.buildId=4.22.0.I20211124-1800
java.version=14.0.2
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_GB
Framework arguments:  -product org.eclipse.epp.package.java.product -product org.eclipse.epp.package.java.product
Command-line arguments:  -os win32 -ws win32 -arch x86_64 -product org.eclipse.epp.package.java.product -data file:/C:/Users/odemeijer/eclipse-workspace/ -product org.eclipse.epp.package.java.product

Exception Stack Trace:
java.lang.NullPointerException
	at org.eclipse.jdt.internal.compiler.ast.LambdaExpression.internalIsCompatibleWith(LambdaExpression.java:906)
	at org.eclipse.jdt.internal.compiler.ast.LambdaExpression.isCompatibleWith(LambdaExpression.java:886)
	at org.eclipse.jdt.internal.compiler.lookup.ConstraintExpressionFormula.reduce(ConstraintExpressionFormula.java:75)
	at org.eclipse.jdt.internal.compiler.lookup.BoundSet.reduceOneConstraint(BoundSet.java:985)
	at org.eclipse.jdt.internal.compiler.lookup.InferenceContext18.reduce(InferenceContext18.java:1072)
	at org.eclipse.jdt.internal.compiler.lookup.InferenceContext18.solve(InferenceContext18.java:1023)
	at org.eclipse.jdt.internal.compiler.lookup.ParameterizedGenericMethodBinding.computeCompatibleMethod18(ParameterizedGenericMethodBinding.java:249)
	at org.eclipse.jdt.internal.compiler.lookup.ParameterizedGenericMethodBinding.computeCompatibleMethod(ParameterizedGenericMethodBinding.java:92)
	at org.eclipse.jdt.internal.compiler.lookup.Scope.computeCompatibleMethod(Scope.java:841)
	at org.eclipse.jdt.internal.compiler.lookup.Scope.computeCompatibleMethod(Scope.java:798)
	at org.eclipse.jdt.internal.compiler.lookup.Scope.getStaticFactory(Scope.java:5297)
	at org.eclipse.jdt.internal.compiler.ast.AllocationExpression.inferElidedTypes(AllocationExpression.java:644)
	at org.eclipse.jdt.internal.compiler.ast.AllocationExpression.checkTypeArgumentRedundancy(AllocationExpression.java:680)
	at org.eclipse.jdt.internal.compiler.ast.AllocationExpression.resolveType(AllocationExpression.java:516)
	at org.eclipse.jdt.internal.compiler.ast.MessageSend.resolveType(MessageSend.java:790)
	at org.eclipse.jdt.internal.compiler.ast.MessageSend.resolveType(MessageSend.java:790)
	at org.eclipse.jdt.internal.compiler.ast.ReturnStatement.resolve(ReturnStatement.java:337)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolveStatements(AbstractMethodDeclaration.java:661)
	at org.eclipse.jdt.internal.compiler.ast.MethodDeclaration.resolveStatements(MethodDeclaration.java:362)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolve(AbstractMethodDeclaration.java:570)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1503)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1628)
	at org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration.resolve(CompilationUnitDeclaration.java:667)
	at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:1240)
	at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:712)
	at org.eclipse.jdt.core.dom.ASTParser.internalCreateAST(ASTParser.java:1245)
	at org.eclipse.jdt.core.dom.ASTParser.createAST(ASTParser.java:868)
	at org.eclipse.jdt.core.manipulation.CoreASTProvider$1.run(CoreASTProvider.java:272)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45)
	at org.eclipse.jdt.core.manipulation.CoreASTProvider.createAST(CoreASTProvider.java:264)
	at org.eclipse.jdt.core.manipulation.CoreASTProvider.getAST(CoreASTProvider.java:197)
	at org.eclipse.jdt.core.manipulation.SharedASTProviderCore.getAST(SharedASTProviderCore.java:138)
	at org.eclipse.jdt.internal.ui.viewsupport.SelectionListenerWithASTManager$PartListenerGroup.calculateASTandInform(SelectionListenerWithASTManager.java:166)
	at org.eclipse.jdt.internal.ui.viewsupport.SelectionListenerWithASTManager$PartListenerGroup$1.run(SelectionListenerWithASTManager.java:151)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)