On Wed, Jul 09, 2008 at 06:32:12PM +0200, Sam Ravnborg wrote:
> So the expalnation seems that gcc for mips define much more
> than the usual gcc does.
> My gcc define 76 symbols for i386.
> And we use this stuff in the kernel.
How much of it do we really use? Let's see - on i386 gcc-4.1.2 I see
79 symbols. 64 simply never occur in the tree. At all. Out of remaining
15, we have
__GNUC__, __GNUC_MAJOR__, __GNUC_PATCHLEVEL__ - provided by sparse.
__STDC__: few users, provided by sparse.
__SIZE_TYPE__: one odd user, defined by sparse anyway
__PTRDIFF_TYPE__: one odd user, defined by sparse anyway
__linux__ - few users, explicitly added in top-level Makefile
linux - 3 users. Defined in top-level Makefile.
unix - no real users (some instances, of course, but none outside of comments,
#include pathnames and string constants). Defined in top-level Makefile,
__USER_LABEL_PREFIX__, __REGISTER_PREFIX__ - arch/m68knommu/lib/*.S; not
a sparse fodder anyway *and* defaults are given in files themselves.
__ELF__: arch/alpha/boot/tools/objstrip.c (userland helper, actually, *and*
misplaced there; it's used as a proxy for type of kernel image)
__i386__: a bunch
__i386: one user, redundant (__i386__ *and* i386 in the same #if)
i386: 3 users besides the aforementioned one.
So... Only 3 symbols out of the entire bunch are arch-dependent *and* not
provided by sparse itself. Absolute majority of the rest is never ever
used in the tree.
I very much doubt that mips situation is seriously different...