__IMPLEMENT_CALLCONTEXT_CLASS defines its ActivityClassName constructor as taking a formatString parameter annotated as _In_opt_ _Printf_format_string_, then passes this formatString to SetMessage().
Unfortunately, SetMessage is annotated as _Printf_format_string_ (null not allowed), which results in a C28218 warning, which appears to be an internal compiler error since after you unpack the macros, it ultimately complains that a declaration isn't consistent with itself.
Turns out we never pass null as the formatString to the ActivityClassName constructor, the _In_opt_ annotation was unnecessarily generous. Change it from _In_opt_ to _In_ to avoid the warning.
__IMPLEMENT_CALLCONTEXT_CLASSdefines itsActivityClassNameconstructor as taking aformatStringparameter annotated as_In_opt_ _Printf_format_string_, then passes thisformatStringtoSetMessage().https://github.com/microsoft/wil/blob/5f63f8d577e0718cc57261f821faa5ea7da5cbb9/include/wil/Tracelogging.h#L1511-L1516
Unfortunately, SetMessage is annotated as
_Printf_format_string_(null not allowed), which results in a C28218 warning, which appears to be an internal compiler error since after you unpack the macros, it ultimately complains that a declaration isn't consistent with itself.https://github.com/microsoft/wil/blob/5f63f8d577e0718cc57261f821faa5ea7da5cbb9/include/wil/Tracelogging.h#L311
Turns out we never pass null as the
formatStringto theActivityClassNameconstructor, the_In_opt_annotation was unnecessarily generous. Change it from_In_opt_to_In_to avoid the warning.