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This is yet another NullPointerException thrown from the Eclipse's Java compiler: ----- eclipse.buildId=4.17.0.I20200902-1800 java.version=11.0.8 java.vendor=AdoptOpenJDK BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=cs_CZ Framework arguments: -product org.eclipse.epp.package.jee.product -product org.eclipse.epp.package.jee.product Command-line arguments: -os win32 -ws win32 -arch x86_64 -product org.eclipse.epp.package.jee.product -data d:\workspace\eclipse-compiler-npe -product org.eclipse.epp.package.jee.product ... org.eclipse.jdt.core.manipulation Error Sat Oct 10 17:09:11 CEST 2020 Error in JDT Core during AST creation java.lang.NullPointerException at org.eclipse.jdt.internal.compiler.ast.ASTNode.checkInvocationArgument(ASTNode.java:363) at org.eclipse.jdt.internal.compiler.ast.ASTNode.checkInvocationArguments(ASTNode.java:449) at org.eclipse.jdt.internal.compiler.ast.MessageSend.resolveType(MessageSend.java:953) at org.eclipse.jdt.internal.compiler.ast.LocalDeclaration.resolve(LocalDeclaration.java:409) at org.eclipse.jdt.internal.compiler.ast.LocalDeclaration.resolve(LocalDeclaration.java:270) at org.eclipse.jdt.internal.compiler.ast.Block.resolve(Block.java:131) at org.eclipse.jdt.internal.compiler.ast.LambdaExpression.resolveType(LambdaExpression.java:458) at org.eclipse.jdt.internal.compiler.ast.LambdaExpression.cachedResolvedCopy(LambdaExpression.java:975) at org.eclipse.jdt.internal.compiler.ast.LambdaExpression.resolveExpressionExpecting(LambdaExpression.java:1005) at org.eclipse.jdt.internal.compiler.lookup.InferenceContext18.addConstraintsToC_OneExpr(InferenceContext18.java:681) at org.eclipse.jdt.internal.compiler.lookup.InferenceContext18.addConstraintsToC(InferenceContext18.java:649) at org.eclipse.jdt.internal.compiler.lookup.InferenceContext18.inferInvocationType(InferenceContext18.java:433) at org.eclipse.jdt.internal.compiler.lookup.ParameterizedGenericMethodBinding.computeCompatibleMethod18(ParameterizedGenericMethodBinding.java:271) at org.eclipse.jdt.internal.compiler.ast.MessageSend.isCompatibleWith(MessageSend.java:1100) at org.eclipse.jdt.internal.compiler.lookup.PolyTypeBinding.isCompatibleWith(PolyTypeBinding.java:43) at org.eclipse.jdt.internal.compiler.lookup.Scope.parameterCompatibilityLevel(Scope.java:5068) at org.eclipse.jdt.internal.compiler.lookup.Scope.parameterCompatibilityLevel(Scope.java:5032) at org.eclipse.jdt.internal.compiler.lookup.Scope.computeCompatibleMethod(Scope.java:871) at org.eclipse.jdt.internal.compiler.lookup.Scope.computeCompatibleMethod(Scope.java:798) at org.eclipse.jdt.internal.compiler.lookup.Scope.findMethod0(Scope.java:1756) at org.eclipse.jdt.internal.compiler.lookup.Scope.findMethod(Scope.java:1657) at org.eclipse.jdt.internal.compiler.lookup.Scope.getMethod(Scope.java:3046) at org.eclipse.jdt.internal.compiler.ast.MessageSend.findMethodBinding(MessageSend.java:1017) at org.eclipse.jdt.internal.compiler.ast.MessageSend.resolveType(MessageSend.java:838) at org.eclipse.jdt.internal.compiler.ast.Expression.resolve(Expression.java:1082) at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolveStatements(AbstractMethodDeclaration.java:664) at org.eclipse.jdt.internal.compiler.ast.MethodDeclaration.resolveStatements(MethodDeclaration.java:361) at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolve(AbstractMethodDeclaration.java:573) at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1490) at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1615) at org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration.resolve(CompilationUnitDeclaration.java:662) at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:1243) at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:714) at org.eclipse.jdt.core.dom.ASTParser.internalCreateAST(ASTParser.java:1205) at org.eclipse.jdt.core.dom.ASTParser.createAST(ASTParser.java:820) 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:167) at org.eclipse.jdt.internal.ui.viewsupport.SelectionListenerWithASTManager$PartListenerGroup$1.run(SelectionListenerWithASTManager.java:152) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63) ----- This error happens when having a Java code like in the following highly artificial MRE (the problematic line is marked with "// BUG"; in real life, result of calling `Unchecked.consumer()` would be typically passed to a `forEach` method of a stream): package snippet; import org.jooq.lambda.Unchecked; import lombok.val; public class Snippet { public static void main(String[] args) { Unchecked.consumer(item -> { val res = transform(item.toString());// BUG }); } protected static String transform(Object obj) { return "test: " + obj; } } Here are my findings so far: * The error happens when combining Lombok's `val` and jOOL's `Unchecked.consumer()` as shown above. * It doesn't matter if target Java version is 8 or 11. * There are various ways of how to avoid the error: * use `var` or `final var` instead of `val` since Java 10 * call `Unchecked.<TypeName>consumer()` instead of `Unchecked.consumer()` * don't pass the variable to a method - do inline evaluation of the same stuff * don't call any method on the variable when passing it to a method - so just `transform(item)` in this case Details: * Reproduced also with Eclipse 4.16, i. e. 2020-06. * Lombok version: 1.18.12 (the latest 1.18.14 introduces another bug in Eclipse `java.lang.NoClassDefFoundError: lombok/launch/PatchFixesHider$Transform` -> for another issue) * jOOL version: 0.9.14 * A real life example: [DefaultCasConfigurationPropertiesSourceLocator.java](https://raw.githubusercontent.com/apereo/cas/v6.2.2/core/cas-server-core-configuration-api/src/main/java/org/apereo/cas/configuration/DefaultCasConfigurationPropertiesSourceLocator.java) from CAS project (probably one of the reasons why they don't support Eclipse for building from source).
Created attachment 284418 [details] An example pom.xml for a quick testing project setup
If it helps, I have obtained another error that is probably caused by the same root reason: ----- java.lang.NullPointerException at org.eclipse.jdt.internal.compiler.lookup.Scope.getMethod(Scope.java:3028) at org.eclipse.jdt.internal.compiler.ast.MessageSend.findMethodBinding(MessageSend.java:1017) at org.eclipse.jdt.internal.compiler.ast.MessageSend.resolveType(MessageSend.java:838) at org.eclipse.jdt.internal.compiler.ast.LocalDeclaration.resolve(LocalDeclaration.java:409) at org.eclipse.jdt.internal.compiler.ast.LocalDeclaration.resolve(LocalDeclaration.java:270) at org.eclipse.jdt.internal.compiler.ast.Block.resolve(Block.java:131) at org.eclipse.jdt.internal.compiler.ast.LambdaExpression.resolveType(LambdaExpression.java:458) at org.eclipse.jdt.internal.compiler.ast.ASTNode.resolvePolyExpressionArguments(ASTNode.java:718) at org.eclipse.jdt.internal.compiler.ast.MessageSend.findMethodBinding(MessageSend.java:1024) at org.eclipse.jdt.internal.compiler.ast.MessageSend.resolveType(MessageSend.java:838) at org.eclipse.jdt.internal.compiler.ast.Expression.resolve(Expression.java:1082) at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolveStatements(AbstractMethodDeclaration.java:664) at org.eclipse.jdt.internal.compiler.ast.MethodDeclaration.resolveStatements(MethodDeclaration.java:361) at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolve(AbstractMethodDeclaration.java:573) at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1490) at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1615) at org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration.resolve(CompilationUnitDeclaration.java:662) at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:1243) at org.eclipse.jdt.core.dom.CompilationUnitResolver.resolve(CompilationUnitResolver.java:714) at org.eclipse.jdt.core.dom.ASTParser.internalCreateAST(ASTParser.java:1205) at org.eclipse.jdt.core.dom.ASTParser.createAST(ASTParser.java:820) ... ----- This is thrown when `Unchecked.function()` is used within this code: [ReturnEncryptedAttributeReleasePolicy.java](https://github.com/apereo/cas/blob/v6.2.2/core/cas-server-core-authentication-attributes/src/main/java/org/apereo/cas/services/ReturnEncryptedAttributeReleasePolicy.java). And again, changing `val` to `var` helps to solve the problem...
This bug hasn't had any activity in quite some time. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet. If you have further information on the current state of the bug, please add it. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant. -- The automated Eclipse Genie.
