On Thu, 24 Feb 2005, Paul Eggert wrote: > Dan Manthey <dan_manthey@xxxxxxxxxxx> writes: > > > AS_PACKAGE_SUGGEST([flex 2.5.x],[http://gnu.org/whereever_flex_is.html]) > > OK, but what is the practical difference between that, and something > like this? > > AC_MSG_FAILURE([you need a suitable implementation of "lex" to build > this package. We suggest the latest stable version of flex > <http://www.gnu.org/software/flex/>.]) I was thinking of AS_PACKAGE_SUGGEST (which I'm sure is a bad name) as simply a formatting macro. It might be reasonable to have it as a macro rather than simple next because it might allow collecting all such messages into a single place (like the putative DEPENDENCIES file discussed). > my_warning='you lack a suitable implementation of "lex", so you won't > be able to build this program reliably if you modify .l files.' > > and then append something like this to your configure.ac file: > > case $my_warning in > ?*) AC_MSG_WARN("$my_warning");; > esac I figured this would basically be what AC_MSG_END would do, except possibly push it off to a file rather than a variable, in case the contents were large (which seems more likely if the errors include long explanations of what kind of package is needed and where to find it). > An advantage of this sort of approach is that one can experiment with > these ideas now, to accomplish something in this area. That is, one > can implement them with one's own macros; they don't require any > changes to Autoconf. Later, if the ideas work well in practice, we > can think about how to add Autoconf macros for them (perhaps simply by > incorporating the experimental macros). Indeed, though it is worth noting that sensible use of these ideas may be dependent on conditional tests, which I don't think Stepan's AC_DEFUN'ing AC_IF quite solves (as helpful as it is as an interim solution). It looks like Hugh would _strongly_ desire an actual macro AC_MSG_END (even if it's as simple as Paul's code above) for the simple fact that it would encourage use of such messages. -Dan _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
