[MCOMPILER-415] NullPointerException from javac when compiling AntlrWorks-Jank

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Invalid
• Affects Version/s: 3.1
• Environment: macOS 10.14.6, iMac Pro, AdoptOpenJDK 9, OpenJDK 11.0.2, AdoptOpenJDK 13.0.2
• Assignee: Robert Scholte
• Reporter: Andrew Janke
• Created: 08/May/20 07:12
• Updated: 19/Mar/22 22:48
• Resolved: 11/Sep/21 09:33

Description

I'm working on a project called AntlrWorks-Jank, an attempt to revive the defunct ANTLRWorks application. https://github.com/apjanke/antlrworks2-jank

When compiling the latest work-in-progress version of my code, I'm getting a NullPointerException apparently raised inside the javac code when it's called by the Maven Compiler Plugin.

[antlrworks-jank] $ mvn -e compile
[INFO] Error stacktraces are turned on.
[...]
[INFO] works-editor-antlr4 ................................ FAILURE [  1.026 s]
[INFO] antlr-works-editor ................................. SKIPPED
[INFO] tvl-editor-whitespace .............................. SKIPPED
[INFO] works-editor-antlr3 ................................ SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.028 s
[INFO] Finished at: 2020-05-08T03:01:54-04:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project works-editor-antlr4: Fatal error compiling: CompilerException: NullPointerException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project works-editor-antlr4: Fatal error compiling
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
[...]
Caused by: java.lang.NullPointerException
    at com.sun.tools.javac.main.JavaCompiler.readSourceFile (JavaCompiler.java:825)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment$ImplicitCompleter.complete (JavacProcessingEnvironment.java:1510)
    at com.sun.tools.javac.code.Symbol.complete (Symbol.java:633)
    at com.sun.tools.javac.code.Symbol$ClassSymbol.complete (Symbol.java:1314)
    at com.sun.tools.javac.code.Type$ClassType.complete (Type.java:1139)
    at com.sun.tools.javac.code.Type$ClassType.getTypeArguments (Type.java:1065)
    at com.sun.tools.javac.code.Printer.visitClassType (Printer.java:237)
    at com.sun.tools.javac.code.Printer.visitClassType (Printer.java:52)
    at com.sun.tools.javac.code.Type$ClassType.accept (Type.java:992)
    at com.sun.tools.javac.code.Printer.visit (Printer.java:136)
    at com.sun.tools.javac.util.AbstractDiagnosticFormatter.formatArgument (AbstractDiagnosticFormatter.java:197)
    at com.sun.tools.javac.util.AbstractDiagnosticFormatter.formatArguments (AbstractDiagnosticFormatter.java:165)
    at com.sun.tools.javac.util.BasicDiagnosticFormatter.formatMessage (BasicDiagnosticFormatter.java:111)
    at com.sun.tools.javac.util.BasicDiagnosticFormatter.formatMessage (BasicDiagnosticFormatter.java:67)
    at com.sun.tools.javac.util.AbstractDiagnosticFormatter.formatArgument (AbstractDiagnosticFormatter.java:183)
    at com.sun.tools.javac.util.AbstractDiagnosticFormatter.formatArguments (AbstractDiagnosticFormatter.java:165)
    at com.sun.tools.javac.util.BasicDiagnosticFormatter.formatMessage (BasicDiagnosticFormatter.java:111)
    at com.sun.tools.javac.util.BasicDiagnosticFormatter.formatMessage (BasicDiagnosticFormatter.java:67)
    at com.sun.tools.javac.util.JCDiagnostic.getMessage (JCDiagnostic.java:771)
    at com.sun.tools.javac.api.ClientCodeWrapper$DiagnosticSourceUnwrapper.getMessage (ClientCodeWrapper.java:799)
    at org.codehaus.plexus.compiler.javac.JavaxToolsCompiler.compileInProcess (JavaxToolsCompiler.java:149)
    at org.codehaus.plexus.compiler.javac.JavacCompiler.performCompile (JavacCompiler.java:169)
    at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute (AbstractCompilerMojo.java:785)
    at org.apache.maven.plugin.compiler.CompilerMojo.execute (CompilerMojo.java:129)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)

The full code to reproduce is on the NPE-during-compile tag in that repo: https://github.com/apjanke/antlrworks2-jank/tree/NPE-during-compile.

I think I'm running the latest 3.8.1 version of maven-compiler-plugin, since I'm not specifying a version for it in my POMs. Seems to happen with Java 9, 11, and 13 (which I'm selecting by setting the $JAVA_HOME environment variable before running `mvn -e compile`).

Would this be a bug in maven-compiler-plugin? Or actually a bug in javac? Or something else?

Find output of `mvn -e compile &>antlrworks-jank-mvn-compile-NPE.log` and `mvn -X -e compile &>antlrworks-jank-mvn-compile-NPE-debug.log` attached.

Issue Links

• links to: JDK-8216202