Resource Leak processor throws an exception when @MustCall is annotated on a Type Variable

[weijunkong]

Commands
./checker-framework-3.16.0/checker/bin/javac -processor resourceleak MustCallBug.java

Inputs

\\ MustCallBug.java
import java.util.List;
import org.checkerframework.checker.mustcall.qual.MustCall;
import org.checkerframework.checker.mustcall.qual.Owning;

public class MustCallBug {
  public <T extends Component> void initialize(
      List<T> list,
      @Owning @MustCall("initialize") T object) {
    object.initialize();
    list.add(object);
  }

  private static class Component {
    void initialize() {}
  }
}

Outputs

error: Unexpected null argument:  areSameByName(null, @org.checkerframework.checker.calledmethods.qual.CalledMethodsBottom)
  ; The Checker Framework crashed.  Please report the crash.
  Compilation unit: MustCallBug.java
  Last visited tree at line 5 column 1:
  public class MustCallBug {
  Exception: java.lang.Throwable; java.lang.Throwable
        at org.checkerframework.javacutil.BugInCF.<init>(BugInCF.java:32)
        at org.checkerframework.javacutil.AnnotationUtils.areSameByName(AnnotationUtils.java:131)
        at org.checkerframework.javacutil.AnnotationUtils.areSame(AnnotationUtils.java:110)
        at org.checkerframework.common.accumulation.AccumulationAnnotatedTypeFactory$AccumulationQualifierHierarchy.isSubtype(AccumulationAnnotatedTypeFactory.java:467)
        at org.checkerframework.checker.resourceleak.MustCallConsistencyAnalyzer.calledMethodsSatisfyMustCall(MustCallConsistencyAnalyzer.java:1581)
        at org.checkerframework.checker.resourceleak.MustCallConsistencyAnalyzer.checkMustCall(MustCallConsistencyAnalyzer.java:1494)
        at org.checkerframework.checker.resourceleak.MustCallConsistencyAnalyzer.handleSuccessorBlocks(MustCallConsistencyAnalyzer.java:1286)
        at org.checkerframework.checker.resourceleak.MustCallConsistencyAnalyzer.analyze(MustCallConsistencyAnalyzer.java:203)
        at org.checkerframework.checker.resourceleak.ResourceLeakAnnotatedTypeFactory.postAnalyze(ResourceLeakAnnotatedTypeFactory.java:109)
        at org.checkerframework.framework.type.GenericAnnotatedTypeFactory.analyze(GenericAnnotatedTypeFactory.java:1543)
        at org.checkerframework.framework.type.GenericAnnotatedTypeFactory.performFlowAnalysis(GenericAnnotatedTypeFactory.java:1391)
        at org.checkerframework.framework.type.GenericAnnotatedTypeFactory.checkAndPerformFlowAnalysis(GenericAnnotatedTypeFactory.java:1812)
        at org.checkerframework.framework.type.GenericAnnotatedTypeFactory.preProcessClassTree(GenericAnnotatedTypeFactory.java:412)
        at org.checkerframework.common.basetype.BaseTypeVisitor.visitClass(BaseTypeVisitor.java:479)
        at org.checkerframework.common.basetype.BaseTypeVisitor.visitClass(BaseTypeVisitor.java:190)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:808)
        at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:56)
        at org.checkerframework.framework.source.SourceVisitor.visit(SourceVisitor.java:82)
        at org.checkerframework.framework.source.SourceChecker.typeProcess(SourceChecker.java:989)
        at org.checkerframework.common.basetype.BaseTypeChecker.typeProcess(BaseTypeChecker.java:542)
        at org.checkerframework.javacutil.AbstractTypeProcessor$AttributionTaskListener.finished(AbstractTypeProcessor.java:188)
        at jdk.compiler/com.sun.tools.javac.api.ClientCodeWrapper$WrappedTaskListener.finished(ClientCodeWrapper.java:828)
        at jdk.compiler/com.sun.tools.javac.api.MultiTaskListener.finished(MultiTaskListener.java:132)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1394)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1351)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:947)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:311)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:170)
        at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
        at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)
1 error

Expectation
Checker Framework should be able to handle this example and not throw an exception.

[mernst]

Thank you for reporting the crash! We appreciate it.

I have committed the test case as checker/tests/resourceleak/Issue4815.java.

The crash does not occur when running the Must Call Checker with -processor mustcall.

[kelloggm]

#4821 resolves the crash. A false positive error is still issued by the checker (which isn't ideal), but I think that's a separate issue (I don't think the Called Methods Checker handles type variables very precisely).

[msridhar]

Should we file a follow-up issue to fix the false positive, or keep this issue open for that problem as well?

[kelloggm]

I think a follow up issue would be better. I'll wait until this one is closed, though.

[kelloggm]

Closed in favor of #4837, which describes only the false positive. The crash (which this issue represents) has been fixed.