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!
-------------
Commit messages:
- Fix regression
- Separate LintWarnings from Warnings in CompilerProperties
- Simplify code
- All langtools tests pass
- All tests pass
- Use diagnostic info line to declare lint category
- Builds ok
- Tweak warning keys in compiler.properties
Changes: https://git.openjdk.org/jdk/pull/22553/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22553&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8345263
Stats: 598 lines in 24 files changed: 234 ins; 110 del; 254 mod
Patch: https://git.openjdk.org/jdk/pull/22553.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/22553/head:pull/22553
PR: https://git.openjdk.org/jdk/pull/22553
