[PATCH] D44826: Add -Wunused-using, a warning that finds unused using declarations.

[Carlos Alberto Enciso via Phabricator via cfe-commits]

CarlosAlbertoEnciso added inline comments.


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Comment at: include/clang/Basic/DiagnosticSemaKinds.td:282-290
+def warn_unused_using_declaration : Warning<
+  "unused using declaration %0">,
+  InGroup<UnusedUsing>, DefaultIgnore;
+def warn_unused_using_directive : Warning<
+  "unused using directive %0">,
+  InGroup<UnusedUsing>, DefaultIgnore;
+def warn_unused_using_alias : Warning<
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lebedev.ri wrote:
> JFYI you can condense it down to just
> ```
> def warn_unused_using_declaration : Warning<
>   "unused %select{using declaration|using directive|namespace alias}0 %1">,
>   InGroup<UnusedUsing>, DefaultIgnore;
> ```
> if that simplifies the code that actually emits that warning.
Thanks for the suggestion.

I will have a look at it and see if that simplifies the code that emits the warning.


https://reviews.llvm.org/D44826