DLS_DEAD_LOCAL_STORE SuppressWarnings FindBugs false positive

Question

I'm trying to eliminate a false positive for DLS_DEAD_LOCAL_STORE

Here's what I have tried so far:

@SuppressWarnings("DLS_DEAD_LOCAL_STORE")

@edu.umd.cs.findbugs.annotations.SuppressWarnings("DLS_DEAD_LOCAL_STORE")

(based on SuppressWarnings not working on FindBugs)

@edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "DLS_DEAD_LOCAL_STORE", justification = "please go away")

based on http://osdir.com/ml/java-findbugs-general/2010-06/msg00017.html

But none of the options is helping. Please advice. Using Eclipse Indigo.

score 9 · Accepted Answer · answered Jul 22 '13 at 23:17

More Googling + Experimenting and I finally figured out a way to do this.

Check Section 6 under http://findbugs.sourceforge.net/manual/filter.html .

You need to create your own XML file with all the custom supressions in there. You'll then need let build.xml file know about this file via findbugs.exclude.filter

 <Match>
   <Class name="com.foobar.MyClass" />
   <Method name="someMethod" />
   <Bug pattern="DLS_DEAD_LOCAL_STORE" />
 </Match>

No need to add the @SuppressWarnings tag in the method once this is there in the XML.

Hope this helps someone!

If you are looking for a solution to fix Android build, add following to build.gradle: findbugs { excludeFilter = file("findBugsFilter.xml") } — Abhijeet, Jun 01 '17 at 01:40

score 7 · Answer 2 · answered May 25 '14 at 17:01

I just had the same problem with this code:

@Test
public void testSomething() {

    @SuppressWarnings("unused")
    @SuppressFBWarnings(value = "DLS_DEAD_LOCAL_STORE")
    final SomeMockClass mock = new SomeMockClass();
    ...
    }
}

The @SuppressFBWarnings does not work here.

The solution here was to move the @SuppressFBWarnings up to the method level:

@Test
@SuppressFBWarnings(value = "DLS_DEAD_LOCAL_STORE")
public void testSomething() {

    @SuppressWarnings("unused")
    final SomeMockClass mock = new SomeMockClass();
    ...
    }
}

I like to keep the scope of these annotations as small as possible, so they don't suppress real problems. Here it seems to be necessary to annotate the whole method.

The actual problem seems to be that FindBugs doesn't allow suppressing `DLS_DEAD_LOCAL_STORE` for **final** local variables (as in your example) when using Sun/Oracle's javac compiler, [as explained here](http://findbugs.sourceforge.net/bugDescriptions.html). — Andres F., Jul 27 '16 at 14:45

score 3 · Answer 3 · answered Jul 27 '16 at 14:48

As explained in FindBugs documentation, apparently Sun/Oracle's javac compiler often generates dead stores for final local variables. These DLS_DEAD_LOCAL_STORE warnings cannot be easily suppressed.

Not sure why the XML filter does work (as in the accepted answer), though.

DLS_DEAD_LOCAL_STORE SuppressWarnings FindBugs false positive

3 Answers3