For the kernel, it would be logical to use -ffreestanding.  The kernel is
not a hosted environment with a standard C library.

The gcc option -ffreestanding is supported by both gcc 2.95 and 3.4, which
covers the whole range of currently supported compilers.

Regarding changes caused by this patch:

Andi Kleen reported:
  Newer gcc rewrites sprintf(buf,"%s",str) to strcpy(buf,str) transparently.

This is only true with unit-at-a-time (disabled on i386 but enabled on
x86_64).  The Linux kernel doesn't offer a standard C library, and such
transparent replacements of kernel functions with builtins are quite
fragile.

Even with -ffreestanding, it's still possilble to explicitely use a gcc
builtin if desired.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>