[PATCH] D150528: [Clang] Fix the diagnoses when the argument to alignas is an incomplete type

[Yurong via Phabricator via cfe-commits]

yronglin marked 3 inline comments as done.
yronglin added a comment.

Thanks a lot for your review @aaron.ballman ! BTW, does the most good approach is that we just add a new `ParsedAttribute` with `TypeSourceInfo` but not an `UnaryExprOrTypeTraitExpr`?



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Comment at: clang/docs/ReleaseNotes.rst:279-281
+- Clang now correctly diagnoses when the argument to alignas is an incomplete type.
+  (`#55175: <https://github.com/llvm/llvm-project/issues/55175>`_,
+  Incorrect mention of 'alignof' in a diagnostic about 'alignas').
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aaron.ballman wrote:
> 
+1, and add _Alignas


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Comment at: clang/lib/Sema/SemaExpr.cpp:4714
+/// [dcl.align] An alignment-specifier of the form alignas(type-id) has the same
+/// effect as alignas(​alignof(type-id)).
+ExprResult Sema::ActOnAlignasTypeArgument(StringRef KWName, ParsedType Ty,
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aaron.ballman wrote:
> It looks like a zero-width joiner was added here around the `!` that should be removed.
Thanks, removed.


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https://reviews.llvm.org/D150528