Unable to build llvm/clang 10.0.1 sources using visual studio 2017 compiler

Hi Team,
I downloaded the llvm/clang sources version 10.0.1 ,built the visual studio solution using cmake. I am using Windows as my platform and visual studio version is 2017 community edition.

I get the compilation error as shown in the below screenshot.
Is llvm/clang 10.0.1 buildable using MSVC 2017 or is there a known issue.
Please guide me.
Thanks in advance

Thanks and Regards
Sudhindra Kulkarni

We do still support the VS 2017 compiler series, but we don’t support the earliest release. Try updating VS 2017.

I looked at the code in raw_ostream.h, reduced it, and did some experiments with it on godbolt:


As you can see, MSVC 19.10 rejects this code, but 19.14 and newer accept this code. So, my recommendation is to update the compiler. You don’t have to upgrade to VS 2019, you just need to run the updater inside Visual Studio.

Coincidentally, we recently raised our minimum _MSC_VER from 1910 to 1914 for unrelated reasons:

If upgrading is impossible, you can simply delete the enum tag in the declaration of changeColors.