[PATCH] D87962: [clang] Change the multi-character character constants from extension to implementation-defined.

Fri Oct 2 06:37:34 PDT 2020

aaron.ballman accepted this revision.
aaron.ballman added a comment.
This revision is now accepted and ready to land.

In D87962#2307824 <https://reviews.llvm.org/D87962#2307824>, @rsmith wrote:

> In D87962#2306043 <https://reviews.llvm.org/D87962#2306043>, @aaron.ballman wrote:
>
>> That doesn't sound like the right approach to me -- Remarks are usually for reporting backend decision-making to the frontend for things like optimization passes.
>
> To be clear: that's how they happen to most visibly be used, but the more general idea is that Remarks are for purely informational messages. One test for whether a diagnostic could reasonably be a remark is: can we imagine anyone ever reasonably wanting to promote it to an error as part of the flags for some project? If so, then use of a remark is inappropriate. That's certainly the case here: it's entirely reasonable to want to be able to reject use of non-portable functionality such as this. So I agree, this should not be a remark.

Thank you for the explanation!

The patch LGTM with a minor nit about the test case.

================
Comment at: clang/test/Lexer/multi-char-constants.c:6
+
+int main() {
+   return 0;
----------------
You can remove the empty `main()`.

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  https://reviews.llvm.org/D87962/new/

https://reviews.llvm.org/D87962