Re: CVS commit: syssrc/sys/conf

[Jason R Thorpe <thorpej%wasabisystems.com@localhost>]

On Thu, Dec 27, 2001 at 12:00:06AM -0500, Nathan J. Williams wrote:

 > > Log Message:
 > > Add -ffreestanding to kernel builds.  It's not always safe to
 > > use GCC's built-ins.
 > 
 > Could you elaborate on the reasoning here? Adding -ffreestanding broke
 > everything that used alloca(), which seems to include a chunk of
 > cardbus, macppc kernels, and the generic ofw_subr code.

Ah.  Then please add a macro that expands it to __builtin_alloca() in
libkern.h.

Anyway, simply put, using GCC built-in's is not always safe in the kernel
environment.  This is especially true with GCC 3.x.

-- 
        -- Jason R. Thorpe <thorpej%wasabisystems.com@localhost>