Re: Prefix for file in source directory used in ./configure?

[Jason Sewall]

Ralf Wildenhues <Ralf.Wildenhues <at> gmx.de> writes:
> $ac_top_srcdir, as documented in "info Autoconf 'Configuration Actions'".
> Since configure is always run the top build directory, it should suffice
> to use $srcdir though.

Well, perhaps I understand less of autoconf than I thought I did.  I
tried to put GIT_VERSION=`$(ac_top_srcdir)/GIT-VERSION-GEN` in there
before even looking for help here, but $(ac_top_srcdir) isn't set at
that point.  I literally have

GIT_VERSION=`./GIT-VERSION-GEN`
AC_SUBST(GIT_VERSION)
AH_TEMPLATE([GIT_VERSION],
            [Git revision of this build])

in my configure.ac file.  It seems like AC_CONFIG_COMMAND runs too
late for the variables to be put in config.h, is that right?

I suspect I'm revealing a deep ignorance of what is actually going on
under the hood here, but I really appreciate the help.

Jason