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    SubjectRe: source dependencies cleanup?
    Date

    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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    of opinion that makes horse races.
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