RFR: 8244681: Add a warning for possibly lossy conversion in compound assignments [v16]

[Adam Sotona]

On Wed, 14 Sep 2022 11:10:15 GMT, Adam Sotona <asotona at openjdk.org> wrote:

>> Please review this patch adding new lint option, **lossy-conversions**, to javac to warn about type casts in compound assignments with possible lossy conversions.
>> 
>> The new lint warning is shown if the type of the right-hand operand of a compound assignment is not assignment compatible with the type of the variable.
>> 
>> The implementation of the warning is based on similar check performed to emit "possible lossy conversion" compilation error for simple assignments. 
>> 
>> Proposed patch also include complex matrix-style test with positive and negative test cases of lossy conversions in compound assignments.
>> 
>> Proposed patch also disables this new lint option in all affected JDK modules and libraries to allow smooth JDK build. Individual cases to address possibly lossy conversions warnings in JDK are already addressed in a separate umbrella issue and its sub-tasks.
>> 
>> Thanks for your review,
>> Adam
>
> Adam Sotona has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 20 commits:
> 
>  - Merge branch 'openjdk:master' into JDK-8244681
>  - Merge branch 'openjdk:master' into JDK-8244681
>  - re-enabled lossy conversions warnings for java.security.jgss, jdk.crypto.ec and jdk.internal.le
>  - Merge branch 'openjdk:master' into JDK-8244681
>  - Merge branch 'openjdk:master' into JDK-8244681
>  - Merge branch 'openjdk:master' into JDK-8244681
>  - re-enabled lossy-conversion javac warnings in JDK Build Tools and jdk.compiler module
>  - Added man-page line about lossy-conversion lint
>  - Merge branch 'openjdk:master' into JDK-8244681
>  - 8244681: Add a warning for possibly lossy conversion in compound assignments
>    re-enabled warnings for java.base, java.rmi and java.smartcardio
>  - ... and 10 more: https://git.openjdk.org/jdk/compare/7f3250d7...4b78b1c5

Please review also linked Release Note issue.

Thanks,
Adam

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PR: https://git.openjdk.org/jdk/pull/8599