[cfe-dev] of -fno-exceptions, ObjC++, __EXCEPTIONS, Mac vs. Linux ... and Qt

[René J. V. Bertin via cfe-dev]

David Chisnall via cfe-dev wrote:


> but it is not defined for Objective-C++ or C++ when exceptions are
> enabled by default. 

That seems like yet something else, but how can this be an Apple bug (it happens 
with Ubuntu builds from llvm.org too when targetting Darwin)? What's more, how 
can it be a bug if it's documented and explained? 

I can imagine why __EXCEPTIONS would be set if any kind of exceptions are 
enabled; it's only for history reasons one might expect that token to be C++-
specific (cf. the -fcxx-exceptions argument; I haven't yet checked if -
fexceptions actually controls both C++ and ObjC exceptions). 

> This bug is also present in clang 4.0, but only with a
> macos target (e.g. x86_64-apple-macos), but not with an ios target.

The lack of consistency certainly seems to be a bug.