Re: AC_ARG_VAR 2.53

[Pontus Skoeld]

Akim Demaille <address@hidden> writes:

> Pontus> if test -z "$FOO_PROG"; then
> Pontus> AC_PATH_PROG(FOO_PROG,foo,missing) fi
> 
> Pontus> AC_ARG_VAR(FOO_PROG)
> 
> Pontus> and if the user runs
> 
> Pontus> $ PATH=$PATH:/path/to/foo ./configure
> 
> Pontus> config.status --recheck will pass FOO_PROG to configure, but
> Pontus> that seems not to be the case.
> 
> Yes, that's the correct behavior: what is actually precious is the
> value specified by the user, not what the script computes.
 
Ok.
 
> Actually, it seems to me that you suggest that PATH be precious.
> That's a good idea.

That was my intended work-around (and for me, right now, they are
equivalent). 
 
> Pontus> If this is not a bug but the way that precious variables are
> Pontus> supposed to be used (i.e. it's impossible to "create" precious
> Pontus> variables) I think it should be stressed in the documentation
> Pontus> for AC_ARG_VAR.
> 
> Please, suggest a better wording!

How about something like 

address@hidden:/tmp/autoconf-2.53/doc$ diff -u autoconf.texi.old autoconf.texi
--- autoconf.texi.old   Thu Sep  5 08:39:03 2002
+++ autoconf.texi       Thu Sep  5 09:04:10 2002
@@ -6041,6 +6041,14 @@
 @end itemize
 @end defmac
 
+Note that what's precious is the actual user supplied configuration
+(be it explicit to @command{configure} or implicit through an
+environment variable). Thus, you cannot make just any variable
+precious and expect it to be treated as such, if the user doesn't
+supply the given variable, @code{AC_ARG_VAR} does nothing.
+
+Certain variables are considered precious by default and neet not be
+marked as precious, these are currently ...
 
 @node Caching Results
 @section Caching Results
address@hidden:/tmp/autoconf-2.53/doc$ 

Where "does nothing" may need to be changed if the above statement is
not true and it may possibly be better to note that variables are
precious where they are normally defined instead of listing them here.

        /Pontus
-- 

Pontus Sköld, see <URL:http://soua.net/> for more information.