Re: Re%3A%5BPATCH%5D%20document%20the%20use%20of%20stamps%20in%20gcc%2FMakefile.in

["Rafael EspÃndola" <rafael dot espindola at gmail dot com>]

> The old, deprecated, non-side-effect automatic dependency
> computation.  There are better ways to do this that don't force the
> early creation of such files.
From the GNU make manual:
----------------------------------------------
The practice we recommend for automatic prerequisite generation is
to have one makefile corresponding to each source file.  For each
source file `NAME.c' there is a makefile `NAME.d' which lists what
files the object file `NAME.o' depends on.  That way only the source
files that have changed need to be rescanned to produce the new
prerequisites.
----------------------------------------------
A bit off-topic, but what is the recommended way of doing automatic
dependency computation?

> > It is a way of informing GCC that we have messed with its
> > dependency graph and that it should reconsider.
>
> I really don't see how touching an empty header file would accomplish
> anything like that, though.
Touching a file present in a "include" will cause make to restart (and
rebuild the graph)

> > In this case, the next time that it starts, the stamp will no longer
> > exist and make will work correctly.
>
> Ah, you're talking about removing the stamp file?  That would work,
> but might cause one undesirable build failure.  In the absence of a
> better solution, we might go with that, but it would be ideal to get
> it to do the right thing always.
Yes. The only difference in my proposal is that make is restarted
after removing the stamp to force the recreation of the dependency
graph.

Rafael