Re: Automatically keeping "last modified" up to date

[Hans-Bernhard B. <HBB...@t-...>]

On 07.08.2013 19:49, sfeam (Ethan Merritt) wrote:

> How about changing version.c to something like
>
> #ifndef LAST_MODIFIED
> #define LAST_MODIFIED "2012-06-19"
> #endif
> const char gnuplot_date[] = LAST_MODIFIED;
>
> And then using some autotools magic that I would have to hunt for
> do something along the lines of

It would have to be different magic, I'm afraid.  Autotools isn't run at 
the point in time that counts: a simple re-make of an already configured 
source tree.

> LAST_MODIFIED = <some magic involving awk or grep>
> DEFS = $DEFS -DLAST_MODIFIED=${LAST_MODIFIED}

> That should reproduce the current behavior without modifying
> any source files.

Not quite.  Changes to non-source files (like the Makefile) don't 
trigger re-builds of version.o.  There has to be some artificial 
dependence of version.o on ChangeLog added to the generated Makefile.