> > What we need is a rule that forces a rebuild when data.h
> is missing.
> >
> > data.c: data.foo
> > foo data.foo
> > data.h: data.c
> > @if test -f $@; then :; else \
> > rm -f data.c; \
> > $(MAKE) $(AM_MAKEFLAGS) data.c; \
> > fi
> >
>
> I believe this fails on the following corner case. Suppose the
> date ordering is like this (with data.h being the oldest):
> data.h data.foo data.c
>
> data.h is out of date with respect to data.foo, so one wants to
> rebuild it, but I don't think that will happen:
> - data.c is up to date with respect to data.foo, so the first
> rule doesn't fire
> - data.h is out of date with respect to data.c, so the second
> rule does fire, but its action doesn't do anything because
> data.h already exists
Wouldn't this help somewhat for a case like this:
data.h: data.c
@if test -f $@; then \
touch $@; \
else \
rm -f data.c; \
$(MAKE) $(AM_MAKEFLAGS) data.c; \
fi
It wouldn't do anything about the contents of the file (but, like
Robert said, the user made a boo-boo by editing/touching data.c
in the first place), but it would prevent rerunning this rule's
commands on every subsequent make invocation.
