[PATCH] D114382: [clang] Fix wrong -Wunused-local-typedef warning within a template function

[Kristina Bessonova via Phabricator via cfe-commits]

krisb added inline comments.


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Comment at: clang/test/SemaCXX/warn-unused-local-typedef.cpp:246
+      typedef int Int; // no-diag
+      typedef char Char; // expected-warning {{unused typedef 'Char'}}
+      Int m;
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Quuxplusone wrote:
> I haven't tried to understand the main point of this PR, but FWIW, have you seen https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61596 ? This looks suspiciously like that exact case. (I just filed its dup https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104792 the other day.)
This patch prevents clang from warning on used typedefs (`Int` case), if those typedefs are defined within a local class of a templated function or a member function of a templated class.
For `Char` case, which is unused in this example, the patch changes nothing.

Regarding https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104792, those typedefs seem well known, so could we just make clang skipping any checks for those particular names?
Alternatively, we would likely need to stop warning on any typedefs defined within a function-local class (but those warnings may still be useful like in the test from this patch).


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D114382/new/

https://reviews.llvm.org/D114382