Unhandled Exception NPE - UnusedNestedClass

[nescohen]

Description of the problem / feature request:

An unhandled exception was thrown by the Error Prone static analysis plugin.
Please report this at https://github.com/google/error-prone/issues/new and include the following:
error-prone version: 2.3.3
BugPattern: UnusedNestedClass

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Follow instructions from https://errorprone.info/docs/installation to install error-prone on google/gson and build with mvn clean package (JDK 11)

What version of Error Prone are you using?

2.3.3

Full Stack Trace

[ERROR]      Stack Trace:
[ERROR]      java.lang.NullPointerException
[ERROR]         at com.google.errorprone.util.ASTHelpers.enclosingClass(ASTHelpers.java:880)
[ERROR]         at com.google.errorprone.bugpatterns.UnusedNestedClass$ClassUsageScanner.handle(UnusedNestedClass.java:116)
[ERROR]         at com.google.errorprone.bugpatterns.UnusedNestedClass$ClassUsageScanner.visitMemberSelect(UnusedNestedClass.java:105)
[ERROR]         at com.google.errorprone.bugpatterns.UnusedNestedClass$ClassUsageScanner.visitMemberSelect(UnusedNestedClass.java:87)
[ERROR]         at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:2118)
[ERROR]         at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:82)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.visitRequires(TreeScanner.java:880)
[ERROR]         at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCRequires.accept(JCTree.java:2852)
[ERROR]         at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:82)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:90)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:105)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:113)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.visitModule(TreeScanner.java:853)
[ERROR]         at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCModuleDecl.accept(JCTree.java:2701)
[ERROR]         at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:82)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:105)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:113)
[ERROR]         at jdk.compiler/com.sun.source.util.TreeScanner.visitCompilationUnit(TreeScanner.java:144)
[ERROR]         at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:591)
[ERROR]         at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:56)
[ERROR]         at com.google.errorprone.bugpatterns.UnusedNestedClass.matchCompilationUnit(UnusedNestedClass.java:62)
[ERROR]         at com.google.errorprone.scanner.ErrorProneScanner.processMatchers(ErrorProneScanner.java:433)
[ERROR]         at com.google.errorprone.scanner.ErrorProneScanner.visitCompilationUnit(ErrorProneScanner.java:541)
[ERROR]         at com.google.errorprone.scanner.ErrorProneScanner.visitCompilationUnit(ErrorProneScanner.java:150)
[ERROR]         at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:591)
[ERROR]         at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:56)
[ERROR]         at com.google.errorprone.scanner.Scanner.scan(Scanner.java:55)
[ERROR]         at com.google.errorprone.scanner.ErrorProneScannerTransformer.apply(ErrorProneScannerTransformer.java:43)
[ERROR]         at com.google.errorprone.ErrorProneAnalyzer.finished(ErrorProneAnalyzer.java:147)
[ERROR]         at jdk.compiler/com.sun.tools.javac.api.MultiTaskListener.finished(MultiTaskListener.java:132)
[ERROR]         at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1418)
[ERROR]         at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1365)
[ERROR]         at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:960)
[ERROR]         at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.lambda$doCall$0(JavacTaskImpl.java:104)
[ERROR]         at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.handleExceptions(JavacTaskImpl.java:147)
[ERROR]         at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:100)
[ERROR]         at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:94)
[ERROR]         at org.codehaus.plexus.compiler.javac.JavaxToolsCompiler.compileInProcess(JavaxToolsCompiler.java:126)
[ERROR]         at org.codehaus.plexus.compiler.javac.JavacCompiler.performCompile(JavacCompiler.java:174)
[ERROR]         at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:1129)
[ERROR]         at org.apache.maven.plugin.compiler.CompilerMojo.execute(CompilerMojo.java:188)
[ERROR]         at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
[ERROR]         at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
[ERROR]         at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
[ERROR]         at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
[ERROR]         at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
[ERROR]         at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
[ERROR]         at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56)
[ERROR]         at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
[ERROR]         at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305)
[ERROR]         at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192)
[ERROR]         at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105)
[ERROR]         at org.apache.maven.cli.MavenCli.execute(MavenCli.java:956)
[ERROR]         at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
[ERROR]         at org.apache.maven.cli.MavenCli.main(MavenCli.java:192)
[ERROR]         at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[ERROR]         at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[ERROR]         at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[ERROR]         at java.base/java.lang.reflect.Method.invoke(Method.java:566)
[ERROR]         at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
[ERROR]         at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
[ERROR]         at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
[ERROR]         at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)```

[cushon]

I can't reproduce this, please re-open if you're still seeing it