On Tue, Mar 18, 2025 at 8:06 AM Paul Smith <psm...@gnu.org> wrote: > I see from the patch: you don't mean "never" you mean, only if the > prerequisite does not exist will it be updated.
Right. > I agree this preserves probably the most common reason for using OO > prereqs (to create directories) This preserves the directory creation use case and also the use of order-only prerequisites for synchronization as sentinel files instead of .WAIT. > but I don't think I like this change. > For one thing it feels too different from normal make behavior, in that > we do "consider" a prerequisite but we do so only to check for > existence, not for out-of-date-ness, which feels odd to me. > > Secondly, I believe the behavior provided by your patch is available > already; you can use $(wildcard ...) to check if a file exists. Isn't > something like this (the gross bits can be hidden in a macro I suppose) > the equivalent of the change in the patch? > > xyz: foo | $(if $(wildcard bar),,bar) ; > > foo bar: ; > > If bar exists then we expand to nothing, else we expand to bar. > It is equivalent, as far as i can tell. What do you think we should do? regards, Dmitry
