> even GCC may not support 100% of the GCC extensions! For example, you can > find hacked GCC's out there which disable nested function support by > default (I think Apple did this).
I'd think that such hacked versions aren't really GCC anymore. > Even more problematic IMO than testing __GNUC__ is code that tests for > particular versions of GCC. There are versions of GCC which have backported > features from more recent GCC's (eg: GNAT from Ada Core Technologies is like > this). Essentially every vendor is like this. And not only for GCC, but for the kernel, etc. But most of them do things properly and stay compatible. -- Eric Botcazou