On 2016-07-26, Rainer Gerhards <rgerhards@xxxxxxxxx> wrote: > I want to add the AX_COMPILE_FLAGS macro to my projects in order to > produce better code. Unfortunately, this macro (more precise: it's > helpers) require at least autoconf 2.64. This is not available on a > number of platforms, Centos 6 is an example (2.61). I don't want to > prevent users from building my projects just because the > AX_COMPILE_FLAGS macro requires newer autoconf -- after all, this is > more or less a development aid. Most users shouldn't need any particular version of autoconf: One of the main features of autoconf is that autoconf is not required simply to build the package: its output is a portable shell script which should be included in your distribution tarballs. For the same reason, making features conditional on the autoconf version has a major problem: distributions built with older autoconf will be missing features that suddenly appear when people autoreconf with a newer autoconf. Autoconf is not hard to install, it's only needed when regenerating the configure script, so IMO it's not too much to ask those users to install a newer version as a dependency. Nevertheless, what you're asking for is still possible. As you observed, AC_AUTOCONF_VERSION was added in version 2.62. But your extra feature requires 2.64, so it won't work in older versions anyway. Thus you can use m4_ifdef to test the existence of AC_AUTOCONF_VERSION, then if it exists test the actual version string, then only if all checks out expand your version-dependent macros. > I initially tried to disable it based on the autoconf version. But I > found out that the macro that obtains this version requires 2.62, > which I also do not have on many platforms. So I tried to add a > conditional switch to disable this macro: > > https://github.com/rsyslog/liblognorm/pull/213/commits/61306142e0f4c972df820d161cc960db563afa53 This link seems to be dead: "We went looking everywhere, but couldn't find those commits". For the benefit of the mailing list archives, it is best to include your code (ideally a small, reproducible test case) directly in the body of your message. Hope that helps, Nick _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
