RFR: 8344159: Add lint warnings for unnecessary warning suppression

[Joe Darcy]

On Tue, 16 Sep 2025 20:03:45 GMT, Archie Cobbs <acobbs at openjdk.org> wrote:

>> Hi @archiecobbs , are there bugs filed to clean the causes of the warnings?
>
>> Hi @archiecobbs , are there bugs filed to clean the causes of the warnings?
> 
> Hi @jddarcy,
> 
> At the beginning of this project as a preliminary step I filed a bunch of bugs+PR's to remove unnecessary `@SuppressWarnings` annotations. These were accepted, but they affected every area of the JDK and people kept adding new ones so it was impractical to keep up. The only way to make this cleanup operation "stick" is to fail the build whenever anyone violates it, and of course that requires that this PR be integrated first. If/when that happens I plan to do one final "mop up" round that should finally stick :)
> 
> Here is the list of earlier clean up PR's:
> 
> * #22906
> * #21859 
> * #21858 
> * #21857 
> * #21856 
> * #21855
> * #21854 
> * #21853 
> * #21852 
> * #21851
> * #21850 
> * #21844

> > Hi @archiecobbs , are there bugs filed to clean the causes of the warnings?
> 
> Hi @jddarcy,
> 
> At the beginning of this project as a preliminary step I filed a bunch of bugs+PR's to remove unnecessary `@SuppressWarnings` annotations. These were accepted, but they affected every area of the JDK and people kept adding new ones so it was impractical to keep up. The only way to make this cleanup operation "stick" is to fail the build whenever anyone violates it, and of course that requires that this PR be integrated first. If/when that happens I plan to do one final "mop up" round that should finally stick :)
> 
> Here is the list of earlier clean up PR's:
> 
>     * [8346953: Remove unnecessary @SuppressWarnings annotations (client, #2) #22906](https://github.com/openjdk/jdk/pull/22906)
> 
>     * [8343486: Remove unnecessary @SuppressWarnings annotations and -Xlint:-foo options #21859](https://github.com/openjdk/jdk/pull/21859)
> 
>     * [8343484: Remove unnecessary @SuppressWarnings annotations (nio) #21858](https://github.com/openjdk/jdk/pull/21858)
> 
>     * [8343483: Remove unnecessary @SuppressWarnings annotations (serviceability) #21857](https://github.com/openjdk/jdk/pull/21857)
> 
>     * [8343482: Remove unnecessary @SuppressWarnings annotations (net) #21856](https://github.com/openjdk/jdk/pull/21856)
> 
>     * [8343481: Remove unnecessary @SuppressWarnings annotations (kulla) #21855](https://github.com/openjdk/jdk/pull/21855)
> 
>     * [8343480: Remove unnecessary @SuppressWarnings annotations (javadoc) #21854](https://github.com/openjdk/jdk/pull/21854)
> 
>     * [8343479: Remove unnecessary @SuppressWarnings annotations (hotspot) #21853](https://github.com/openjdk/jdk/pull/21853)
> 
>     * [8343478: Remove unnecessary @SuppressWarnings annotations (core-libs) #21852](https://github.com/openjdk/jdk/pull/21852)
> 
>     * [8343477: Remove unnecessary @SuppressWarnings annotations (compiler) #21851](https://github.com/openjdk/jdk/pull/21851)
> 
>     * [8343476: Remove unnecessary @SuppressWarnings annotations (client) #21850](https://github.com/openjdk/jdk/pull/21850)
> 
>     * [8343467: Remove unnecessary @SuppressWarnings annotations (security) #21844](https://github.com/openjdk/jdk/pull/21844)

Sounds good; I linked the umbrella issue for the earlier round of cleanup to this issue in JBS.

My interest is getting back to at least a subset of modules, including java.base, compiling under "-Xlint:all -Werror" and it sounds like that is the plan as follow-up work after this PR goes in; thanks.

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PR Comment: https://git.openjdk.org/jdk/pull/25167#issuecomment-3300210592