AaronBallman wrote: > > This should be controllable via -fms-extensions/-fno-ms-extensions; having > > its own dialect flag is a bit novel but I'm not strongly opposed. CC > > @MaskRay @jansvoboda11 for driver/options opinions > > For this feedback I intentionally didn't do this because this ms extension > isn't one intended to be always enabled. -fms-extensions enables extensions > that are always valid to use with msvc such as the `__try` and `__finally` > keywords for SEH.
That's kind of the crux of this -- `-fms-extensions` enables Microsoft extensions, and this is a Microsoft extension. Our documentation is pretty quiet about what it means to "enable Microsoft extensions": https://clang.llvm.org/docs/UsersManual.html#microsoft-extensions > MSVC allows controlling this option independently here, > [/Zc:ReferenceBinding](https://learn.microsoft.com/en-us/cpp/build/reference/zc-referencebinding-enforce-reference-binding-rules?view=msvc-170). > MSVC `/permissive-` disables this reference binding extension, however > `__try` and friends are still available as they are vital for operating > within a Win32 environment. Newer C++ modes like C++20 also implicitly > disable this reference binding extension in MSVC as they move towards proper > C++ conformance by default. > > This is a one off extension similar to -fms-volatile or -fms-define-stdc. I > would like to keep it a separate option that can be individually controlled > instead of grouping it with -fms-extensions. Oh, I think it should still be individually controlled via its own flag. The scenario I am thinking about is when the user passed `-fms-extensions` and no other individual flags. I think that mode should enable all of the Microsoft extensions. Then users can opt out of whatever extensions they don't want to enable. But I think it's confusing if `-fms-extensions` still requires the user to explicitly opt in to other Microsoft-specific extensions. CC @zmodem @rnk for additional opinions. https://github.com/llvm/llvm-project/pull/99833 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
