Re: [PATCH] Document AC_FUNC_FORK cache variables

[Ralf Wildenhues]

Hello Eric,

in
http://thread.gmane.org/gmane.comp.sysutils.autoconf.patches/7500/focus=7501
I asked the following:

* Ralf Wildenhues wrote on Mon, Dec 20, 2010 at 07:57:11AM CET:
> * Colin Watson wrote on Mon, Dec 20, 2010 at 12:33:46AM CET:
> > I maintain a package where I'd like to fail at configure time if fork
> > doesn't work.  This is slightly awkward because 'info autoconf' doesn't
> > document the cache variables for AC_FUNC_FORK, so I don't know whether I
> > can rely on them in future versions of Autoconf.  Would you be willing
> > to document them as follows and thereby promise that they will continue
> > to work?
> 
> The reason we didn't document them right away was because the semantics
> are a bit more complex: while you can read the results in these
> variables, you cannot override the test completely by setting these
> variables.  ac_cv_func_fork and ac_cv_func_vfork are also involved.
> 
> We could change the macro so that the _works variables are not
> overridden when set, or just document the need to also set the
> other two.  Below is a (fairly untested) patch for the former
> (4 new lines plus large reindent).  However, this still differs
> in configure output (the _works result is not communicated in the
> cache case) so I'm not sure this is the better approach.
> 
> Probably easier to append "In order to override the test, you also
> need to set the @code{ac_cv_func_fork} and @code{ac_cv_func_vfork}
> variables."  Eric?

My preference would be to drop my proposed patch (see link above)
and instead push the following in Colin's name, and add him to THANKS.

Any issues with that?

Thanks,
Ralf

2011-03-04  Colin Watson  <...>  (tiny change)
            Ralf Wildenhues  <...>

        * doc/autoconf.texi (Particular Functions): Document AC_FUNC_FORK
        cache variables.
        * THANKS: Update.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index e87b8b4..eea6bc7 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -5004,6 +5004,11 @@ Particular Functions
 #endif
 @end group
 @end example
+
+The results of this macro are cached in the @code{ac_cv_func_fork_works}
+and @code{ac_cv_func_vfork_works} variables.  In order to override the
+test, you also need to set the @code{ac_cv_func_fork} and
address@hidden variables.
 @end defmac
 
 @defmac AC_FUNC_FSEEKO