cmake: disable warnings for operands with different enum types

With a recent upgrade to a newer version of MSVC we now get a bunch of
warnings when two operands use different enum types. While sensible in
theory, in practice we have a couple of non-public enums that extend
public enums, like for example with `GIT_SUBMODULE_STATUS`.

Let's for now disable this warning to unblock our builds. The
alternative would be to add casts all over the place, but that feels
rather cumbersome.

diff --git a/cmake/DefaultCFlags.cmake b/cmake/DefaultCFlags.cmake
index 25a7f82..5abe0c8 100644 (file)
--- a/cmake/DefaultCFlags.cmake
+++ b/cmake/DefaultCFlags.cmake
@@ -13,6 +13,9 @@ if(MSVC)
        # /Gd - explicitly set cdecl calling convention
        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /Gd")
 
+       # Remove warnings about operands that use different enum types.
+       set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /wd5287")
+
        if(NOT (MSVC_VERSION LESS 1900))
                # /guard:cf - Enable Control Flow Guard
                set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /guard:cf")