hans added a comment.
In https://reviews.llvm.org/D43108#1005904, @nruslan wrote:
> @hans: One real-world example is when it is used to compile UEFI code using
> PE/COFF targets natively. Obviously, UEFI uses ABI which is basically almost
> the same as MS ABI, except that chkstk is not used. It mostly works (I
> actually was able to get it running) except the cases when the code contains
> variable-sized arrays allocated on stacks. Unfortunately, stack-probe-size
> will only help with fixed sized array but will not help to solve the problem
> described in the bug description since stack usage is unknown at compile
> time. MinGW does not have this problem because it provides this flag.
I see, interesting. Might be worth mentioning in the commit message for others
wondering what the flag is useful for.
> @MatzeB : there is a test on LLVM side (related review). Do you think the
> test is needed for clang side? If so, please let me know, what kind of test
> it is supposed to be.
Yes please, I think think there should be on in test/Driver/ to check that
forwarding the flag to cc1 (and if we have a -mno-foo, there should maybe be a
-mfoo variant too?), and a test in test/CodeGen/ to check that the attribute
gets put on the functions correctly. Perhaps r321992 is a good example to look
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