[PATCH] D150966: [clang] Don't define predefined macros multiple times

Fri May 19 09:09:10 PDT 2023

barannikov88 added a comment.

In D150966#4356695 <https://reviews.llvm.org/D150966#4356695>, @john.brawn wrote:

>> Q: What is it the -Wsystem-header can warn about? I mean, no system header is included by the test, what can go wrong?
>
> The <built-in> buffer is treated as a system header. I've expanded on the comment to explain this more.

Thanks, I didn't know that <built-in> is treated as a system header, but I was mostly interested in this part

  Check that the predefined macros don't contain anything that causes a warning

What is 'anything', exactly? Does it include duplicate predefined macros, or it tests something else?
Sorry for the silly question.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D150966/new/

https://reviews.llvm.org/D150966