would it serve your purpose to set the time on T in the rule that creates it to be the time on O (instead of the current time)
~Malcolm > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Brian > J. Murrell > Sent: Friday, December 07, 2012 10:42 AM > To: [email protected] > Subject: Re: using the date relationship of two older files as a prerequisite > > On 12-12-07 10:53 AM, Mason wrote: > > > > OK, so "O" is just like a normal source file; it is not created by make, > > and it is created/updated by your text editor. > > Correct. "O" is not created by make, but it's not created in real-time > either like an editor file is. That is, it can get updated but even > when it does while it will be newer than it was before, it will still be > older than the target "T". > > > This paragraph does not make sense (to me). > > > > At some point, "O" is modified (possibly several times). > > Correct. > > > Suppose the "O" was last modified at T1. > > Then you call make, which builds "T" at T2. > > Right. > > > Obviously T1 < T2 > > Correct. > > > If "O" is modified (possibly several times) at T3, > > then "O" is obviously newer than "T" since T2 < T3. > > No. O is modified at let's call it T1.5. (not T3). It's newer than T1 > but older than T2. > > > What am I missing? > > I think you were missing that O is modified at T1.5 after T was rebuilt > at T2. > > The reason O can have a time of T1.5 after T2 is because O lives in an > external source that make can see. That source can be updated but the > latency between it being updated and made available to make is so long > that the updated O is still some time in the past, before T2 in most cases. > > b. > _______________________________________________ Help-make mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-make
