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Regression Tester Report

(comment created at 2026-03-29 10:58:53+00:00 for 1ed4ab7)

@adangel I noticed the regression report does not include this rule -- did I do something wrong here?

@adangel I noticed the regression report does not include this rule -- did I do something wrong here?

Good catch. If the rule doesn't appear in the regression report, this means, there are no instances of violations detected. We only list rules, where there is a violation. That's why there are no rules with 0 violations (either for base or patch).

The ruleset that is used for regression testing is simply this one: https://github.com/pmd/pmd/blob/main/.ci/files/all-regression-rules.xml - which contains java/multihreading.xml which contains OverridingThreadRun

I've tested this rule now separately - it seems to be working.

Now: With the help of IntelliJ I could identify a subclass of thread in java.base, that should have been found: https://github.com/openjdk/jdk/blob/da75f3c4ad5bdf25167a3ed80e51f567ab3dbd01/src/java.base/share/classes/java/lang/ref/Finalizer.java#L151
Note - we don't analyse the whole openjdk 11 source, but only subfolder java.base:

After tinkering a bit, I found the problem: The XPath expression is not correct - it uses count(//FormalParameter) - which searches for formal parameters in the whole compilation unit. So - as soon as there is a single method with one parameter somewhere in the same file, the rule won't find anything anymore.

The better XPath is:

//ClassDeclaration[ pmd-java:typeIs('java.lang.Thread') ]/ClassBody
    /MethodDeclaration[@Name="run"][FormalParameters/@Size=0]

@zbynek Can you please open a new PR to fix this? Then you should see violation in the report...

However, this doesn't find anonymous classes, e.g.

public class Foo {
    public static void main(String[] args) {
      new Thread() {
        public void run() {
          
        }
      }.start();
    }
}

Unfortunately, //AnonymousClassDeclaration[pmd-java:typeIs('java.lang.Thread')] doesn't find this anonymous thread - there is something missing in the type system in PMD. So, this fix wouldn't be straightforward.