[clang-tidy] Add fix descriptions to clang-tidy checks.
Summary:
Motivation/Context: in the code review system integrating with clang-tidy,
clang-tidy doesn't provide a human-readable description of the fix. Usually
developers have to preview a code diff (before vs after apply the fix) to
understand what the fix does before applying a fix.
This patch proposes that each clang-tidy check provides a short and
actional fix description that can be shown in the UI, so that users can know
what the fix does without previewing diff.
This patch extends clang-tidy framework to support fix descriptions (will add implementations for
existing checks in the future). Fix descriptions and fixes are emitted via diagnostic::Note (rather than
attaching the main warning diagnostic).
Before this patch:
```
void MyCheck::check(...) {
...
diag(loc, "my check warning") << FixtItHint::CreateReplacement(...);
}
```
After:
```
void MyCheck::check(...) {
...
diag(loc, "my check warning"); // Emit a check warning
diag(loc, "fix description", DiagnosticIDs::Note) << FixtItHint::CreateReplacement(...); // Emit a diagnostic note and a fix
}
```
Reviewers: sammccall, alexfh
Reviewed By: alexfh
Subscribers: MyDeveloperDay, Eugene.Zelenko, aaron.ballman, JonasToth, xazax.hun, jdoerfert, cfe-commits
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D59932
llvm-svn: 358576
24 files changed