Messages in this thread |  | | From | (Matthias Urlichs) | Subject | Re: source dependencies cleanup? | Date | 5 Dec 1996 00:22:36 +0100 |
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In linux.dev.kernel, article <199612040008.AAA00373@oboe.it.uc3m.es>, "Peter T. Breuer" <ptb@oboe.it.uc3m.es> writes: > > > Not a major pain as the kernel takes a while to compile on this machine > > anyway but I believe (after a quick perusal of the .depend files) that > > mkdep is fast mainly because it skips stuff. > > Absolutely wrong (i.e. "that turns out not to be the case" :). It is
Sorry, but Linus' mkdep _does_ skip stuff.
Assume that a1.c and a2.c both include b.h which in turn includes c.h.
GCC -M output would be a1.o: a1.c b.h c.h a2.o: a1.c b.h c.h
Linus' mkdep instead depends on being executed on the heders too: a1.o: a1.c b.h a2.o: a1.c b.h b.h: c.h touch b.h
This all works out perfectly well. Well... almost. The big advantage of the latter is that you scan b.h only once; gcc scans it twice. The big disadvantage is that you can't keep your kernel sources on a readonly partition.
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