[PATCH] Use AC_SUBST_FILE to replace @DEPEND@ with contents of .depend

[Michael Forney]

Damien Miller <djm at mindrot.org> wrote:
> On Sun, 18 Apr 2021, Michael Forney wrote:
> 
> > AC_SUBST_FILE[0] is similar to AC_SUBST, but instead of replacing
> > a variable with its value, it replaces a variable with the contents
> > of the file named by the value. This is exactly what we want in
> > order to insert the contents of .depend at the end of the Makefile.
> > 
> > Using AC_SUBST for this purpose poses some problems if $as_echo
> > involves running an external command (i.e. printf is not built-in),
> > in which case the size of .depend may exceed the operating system's
> > argument size limit. In particular, since autoconf 2.70, $as_echo
> > no longer uses `print -r` on ksh shells[1], causing the following
> > message when creating config.log on Linux with oksh:
> > 
> >   ./configure: printf: Argument list too long
> > 
> > AC_SUBST_FILE requires the substitution string to be on its own
> > line, so drop the unneeded leading comment (the first line of .depend
> > has a '#' of its own).
> 
> I actually have a few workflows that run make against the Makefile.in
> (e.g. generating cat format manpages as part of release) and these
> break with @DEPEND@ on it's own, uncommented line. I'll need to adjust
> these before merging this.

Hi,

Since newer autoconf is now being used to generate configure in
release archives (for a while now, since 9.1p1), I was wondering
if we might be able to revisit this.

While the printf error message at the end of configure output turns
out to be benign (it affects what's in config.log, not the actual
substitution), it does look like something went wrong.