[8_hours_ago]

Large and complex pieces of software, and operating systems in particular, tend to be tightly tied to their compilers. It is never easy and in some cases practically impossible to port to a different compiler. I expect that Microsoft has come to terms with the fact that Windows will only support being compiled by their compiler.

When a different toolchain introduces a new feature for finding bugs that would be useful for Windows, the Microsoft compiler team can add that functionality to their own tools instead of porting Windows. An advantage of this is that they can customize the feature for exactly their use case. Yes, this is the definition of NIH syndrome, but that’s how large companies work.

[xorblurb]

Large pieces of sw have been able to switch some plateform specific code to other compilers (chrome for windows comes to mind).

This is probably way smaller than the whole Windows, but I would not be surprised if some MS dev are already internally compiling some of their components with clang for their own dev/testing (even if just for extra warnings, etc.)

And a major part of the work of the MSVC team today seems to be about standard compliance.

But yes, I do not really expect that they switch, and actually they probably don't even have the beginning of a serious reason to do so. This is not even a case of NIH. Their compiler derives from an ancient codebase and has been continuously maintained for several decades. They "invented" it. The only modern serious competition (that cares enough about Windows compat and some of their specific techs) has been started way after... They probably also have all kind of patents and whatnot about some security mitigations that are implemented by collaboration between the generated code and (the most modern versions of) low level parts of the Windows platform.