[clang] [clang] Improve `_Alignas` on a `struct` declaration diagnostic (PR #65638)

[Jerin Philip via cfe-commits]

================
@@ -94,7 +94,7 @@ class AttributeCommonInfo {
           IsRegularKeywordAttribute(IsRegularKeywordAttribute) {}
     constexpr Form(tok::TokenKind Tok)
         : SyntaxUsed(AS_Keyword), SpellingIndex(SpellingNotCalculated),
-          IsAlignas(Tok == tok::kw_alignas),
+          IsAlignas(Tok == tok::kw_alignas || Tok == tok::kw__Alignas),
----------------
jerinphilip wrote:

Looking at the activated codepaths, `_Alignas` goes through this (attribute) 
infrastructure for C parsing as well, but fails to disambiguate the `_Alignas` 
vs `alignas` information at `isAlignAs` with this change. Ideas in 
https://github.com/llvm/llvm-project/pull/65638#discussion_r1367333111 requires 
retaining the distinction rather than mixing with an `||`. 

https://github.com/llvm/llvm-project/pull/65638
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits