[PATCH] __FreeBSD_kernel__

[Ed Maste]

On Sun, Jul 03, 2011 at 12:45:12PM -0700, Julian Elischer wrote:

> On 7/3/11 7:35 AM, Alexander Kabaev wrote:
> >__linux__ is exactly what __FreeBSD__ is and dies not identify kernel
> >but rather Linux as whole OS, whatever that might be these days.
> >
> >There does not appear to be an universal macro that identifies
> >environment as using Linux kernel regardless of the rest of components
> >used (say, to identify Android and Ubuntu or something embedded with
> >ucLibc as running Linux kernel with different userland
> >implementations).
> I thought it was (__linux__ && __KERNEL__)

I corresponded with Julian off-list, but for the sake of the archives
I'll summarize here.

This is not correct because __KERNEL__ is used for code or header files
to detect that they are targetting the kernel (e.g., a device driver)
while what we're looking for here is a macro for userland code to detect
that it is being compiled to run _on_ a given kernel (Linux or FreeBSD).

-Ed