Integrated: 8345263: Make sure that lint categories are used correctly when logging lint warnings

[Maurizio Cimadamore]

On Wed, 4 Dec 2024 17:11:26 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

> This PR tightens up the logic by which javac reports lint warnings. Currently, lint warnings are typically emitted using the following idiom:
> 
> 
> if (lint.isEnabled(LintCategory.DIVZERO) {
>     log.warning(LintCategory.DIVZERO, pos, Warnings.DIVZERO);
> }
> 
> There are some issues with this approach:
> 
> * logging a lint warning has to be preceded by the correct `isEnabled` check
> * the check and the `log::warning` call must share the same `LintCategory`
> * the selected warning key in the `Warnings` class must also make sense for the selected `LintCategory`
> 
> This PR addresses these issues, so that the above code is now written as follows:
> 
> 
> lint.logIfEnabled(pos, LintWarnings.DIVZERO);
> 
> 
> The new idiom builds on a number of small improvements:
> 
> * the lint category is now tracked directly in the `compiler.properties` file;
> * a new `LintWarning` class is added to `JCDiagnostic` to model a warning key that is also associated with a speicfic `LintCategory` enum constant;
> * the `CompilerProperties` class has a new group of compiler keys, nested in the new `LintWarnings` class. This class defines the `LintWarning` objects for all the warning keys in `compiler.properties` that have a lint category set
> * A new method `Lint::logIfEnabled(Position, LintWarning)` is added - which simplifies the logging of lint warnings in many common cases, by merging the `isEnabled` check together with the logging.
> 
> As bonus points, the signatures of some methods in `Check` and `MandatoryWarningHandler` have been tightened to accept not just a `Warning`, but a `LintWarning`. This makes it impossible, for instance, to use `Check::warnUnchecked` with a warning that is not a true lint warning.
> 
> Many thanks @archiecobbs for the useful discussions!

This pull request has now been integrated.

Changeset: dbffe332
Author:    Maurizio Cimadamore <mcimadamore at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/dbffe33251da4472945d97ab54c7e3354d7f42d2
Stats:     646 lines in 24 files changed: 254 ins; 116 del; 276 mod

8345263: Make sure that lint categories are used correctly when logging lint warnings

Reviewed-by: vromero, jlahoda

-------------

PR: https://git.openjdk.org/jdk/pull/22553