Re: [PATCH 0/7] minmax: reduce compilation time

Geert Uytterhoeven
2024-07-28T17:57:28Z

Hi Lorenzo,

On Fri, Jul 26, 2024 at 8:57 PM Lorenzo Stoakes
<lorenzo.stoakes@oracle.com> wrote:
> On Fri, Jul 26, 2024 at 11:24:09AM GMT, Linus Torvalds wrote:
> > On Fri, 26 Jul 2024 at 11:13, Lorenzo Stoakes
> > <lorenzo.stoakes@oracle.com> wrote:
> > >
> > > 5,447,539 ./arch/x86/xen/setup.o.pre
> >
> > Can you perhaps do some kind of "max expansion" on all the
> > preprocessor files (you seem to have done it by changing the ".c.o"
> > rule to just spit it out as "o.pre", which sounds fine).
>
> Yeah I simply hacked in a gcc -E, ugly but effective, e.g. prepending
> cmd_cc_o_c in scripts/Makefile.build with:
>
> cmd_cc_o_c = $(CC) $(c_flags) -E $< > $@.pre; \

Kbuild already knows how to build a preprocessed file (.i),
so making any .o depend on its .i should work, too?

Or am I missing something?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds