r199247 - Clarify driver/frontend -fms-compatibility help text

[Nico Rieck]

On 16.01.2014 19:04, Reid Kleckner wrote:
> I think "full" here is OK.  In general, I *want* people to file bugs if
> there code compiles with cl and not clang -fms-compatibility, but I agree
> there are limits to how compatible we can be.  There are some areas where
> we can never be compatible, and we'll have to close them with wontfix /
> infeasible.  Users should be able to understand that.

How are warnings treated there?

For example currently Clang ignores dllimport on typedefs and enums
without warning with -fms-extensions. Aside from the fact that this, if
at all, belongs to -fms-compatibility, the question remains. The
original problem that introduced this is on rdar so I don't know what it
is. I'd much rather axe that special treatment.

And if -fms-compatibility is supposed to be required to compile with
WinSDK headers, it would be a shame if these workarounds must always be
applied globally.

There's already the case with -fdelayed-template-parsing that Clang
accepts broken user-code without any notice and bails on certain valid
things (like template and constexpr combinations), and it's enabled by
default.

-Nico