redhat-developer / redhat-developer/vscode-java

experimental javac compiler: tree.kind is null

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bug javac
Dominant language
TypeScript
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Avg merge
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Merged PRs (30d)
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Description

Hello,

I'm trying the experimental javac compiler and getting the following error:

!ENTRY org.eclipse.jdt.core 4 0 2025-12-29 17:07:42.568
!MESSAGE Error while analyzing
!STACK 0
java.lang.IllegalStateException: java.lang.NullPointerException: Cannot invoke "com.sun.tools.javac.tree.JCTree$JCMemberReference$ReferenceKind.ordinal()" because "tree.kind" is null
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:383)
	at org.eclipse.jdt.core.dom.JavacCompilationUnitResolver.parse(JavacCompilationUnitResolver.java:1025)
	at org.eclipse.jdt.core.dom.JavacCompilationUnitResolver.toCompilationUnit(JavacCompilationUnitResolver.java:602)
	at org.eclipse.jdt.core.dom.ASTParser.internalCreateASTCached(ASTParser.java:1410)
	at org.eclipse.jdt.core.dom.ASTParser.lambda$1(ASTParser.java:1289)
	at org.eclipse.jdt.internal.core.JavaModelManager.cacheZipFiles(JavaModelManager.java:5709)
	at org.eclipse.jdt.core.dom.ASTParser.internalCreateAST(ASTParser.java:1289)
	at org.eclipse.jdt.core.dom.ASTParser.createAST(ASTParser.java:933)
	at org.eclipse.jdt.internal.core.CompilationUnit.buildStructure(CompilationUnit.java:175)
	at org.eclipse.jdt.internal.core.Openable.generateInfos(Openable.java:250)
	at org.eclipse.jdt.internal.core.JavaElement.openWhenClosed(JavaElement.java:571)
	at org.eclipse.jdt.internal.core.JavaElement.getElementInfo(JavaElement.java:294)
	at org.eclipse.jdt.internal.core.JavaElement.getElementInfo(JavaElement.java:280)
	at org.eclipse.jdt.internal.core.CompilationUnit.getCompilationUnitElementInfo(CompilationUnit.java:1605)
	at org.eclipse.jdt.internal.core.CompilationUnit.getCustomOptions(CompilationUnit.java:1583)
	at org.eclipse.jdt.core.ICompilationUnit.getOptions(ICompilationUnit.java:607)
	at org.eclipse.jdt.core.dom.ASTParser.setSource(ASTParser.java:677)
	at org.eclipse.jdt.internal.core.search.indexing.SourceIndexer.indexDocumentFromDOM(SourceIndexer.java:415)
	at org.eclipse.jdt.internal.core.search.indexing.SourceIndexer.indexDocument(SourceIndexer.java:104)
	at org.eclipse.jdt.internal.core.search.JavaSearchParticipant.indexDocument(JavaSearchParticipant.java:91)
	at org.eclipse.jdt.internal.core.search.indexing.IndexManager.indexDocument(IndexManager.java:664)
	at org.eclipse.jdt.internal.core.search.indexing.IndexManager$2.execute(IndexManager.java:1269)
	at org.eclipse.jdt.internal.core.search.processing.JobManager.indexerLoop(JobManager.java:541)
	at java.base/java.lang.Thread.run(Thread.java:1474)
Caused by: java.lang.NullPointerException: Cannot invoke "com.sun.tools.javac.tree.JCTree$JCMemberReference$ReferenceKind.ordinal()" because "tree.kind" is null
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitReference(ThisEscapeAnalyzer.java:972)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMemberReference.accept(JCTree.java:2657)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.invokeUnknown(ThisEscapeAnalyzer.java:685)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.invoke(ThisEscapeAnalyzer.java:594)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitApply(ThisEscapeAnalyzer.java:535)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1860)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitSelect(ThisEscapeAnalyzer.java:934)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:2576)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitApply(ThisEscapeAnalyzer.java:510)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1860)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitAssign(ThisEscapeAnalyzer.java:912)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCAssign.accept(JCTree.java:2105)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitExec(ThisEscapeAnalyzer.java:1080)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1647)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:58)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.visitBlock(TreeScanner.java:150)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.lambda$visitBlock$0(ThisEscapeAnalyzer.java:762)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitScoped(ThisEscapeAnalyzer.java:1274)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitBlock(ThisEscapeAnalyzer.java:762)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1136)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitIf(ThisEscapeAnalyzer.java:1074)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCIf.accept(JCTree.java:1616)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:58)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.visitBlock(TreeScanner.java:150)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.lambda$visitBlock$0(ThisEscapeAnalyzer.java:762)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitScoped(ThisEscapeAnalyzer.java:1274)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitBlock(ThisEscapeAnalyzer.java:762)
	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1136)
	at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.scan(ThisEscapeAnalyzer.java:460)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.lambda$analyzeConstructor$0(ThisEscapeAnalyzer.java:1221)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.visitScoped(ThisEscapeAnalyzer.java:1274)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.analyzeConstructor(ThisEscapeAnalyzer.java:1221)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:186)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1939)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:570)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:560)
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:153)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:176)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:265)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:632)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.doAnalyzeTree(ThisEscapeAnalyzer.java:376)
	at jdk.compiler/com.sun.tools.javac.comp.ThisEscapeAnalyzer.analyzeTree(ThisEscapeAnalyzer.java:244)
	at jdk.compiler/com.sun.tools.javac.comp.WarningAnalyzer.analyzeTree(WarningAnalyzer.java:61)
	at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.warn(JavaCompiler.java:1469)
	at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.warn(JavaCompiler.java:1436)
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:404)
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.lambda$analyze$0(JavacTaskImpl.java:379)
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.invocationHelper(JavacTaskImpl.java:152)
	at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.analyze(JavacTaskImpl.java:379)
	... 23 more

I'm not sure what I can share to be usefull

    "java.jdt.ls.java.home": "~/.asdf/installs/java/openjdk-25/",
    "java.jdt.ls.javac.enabled": "on",
Image

There is no issue compiling with ecj

I can't share the source code of the project but if you tell me where to look with more debugging I can help

Regards

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the reported stack entries in JavacCompilationUnitResolver.parse and jdk.compiler's ThisEscapeAnalyzer.visitReference, using the provided java.jdt.ls.javac.enabled and Java 25 settings. Reproduce the failure with a minimal Java example or obtain a shareable source case; done means the triggering case is isolated and the javac-backed analysis no longer crashes.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
devtools
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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