From: Jérémie Galarneau Date: Mon, 11 Jan 2021 23:11:46 +0000 (-0500) Subject: Fix: configure: support Autoconf 2.70 X-Git-Tag: v2.13.0-rc1~379 X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=faa88ea855741f5c356d223011ff4b347576c7d2;hp=faa88ea855741f5c356d223011ff4b347576c7d2 Fix: configure: support Autoconf 2.70 The newly-released autoconf 2.70 introduces a number of breaking changes [1] and is being rolled-out by some distros. Amongst those changes, the AC_PROG_CC_STDC macro is marked as obsolete and was merged into AC_PROG_CC, which we already use. On 2.70, this results in a warning which we handle as an error. A version check is added to invoke the AC_PROG_CC_STDC macro only when running a pre-2.70 version of autoconf, fixing the issue. A single use of the AC_HELP_STRING macro is replaced by AS_HELP_STRING as the former was marked as obsolete. The AC_PROG_LEX now takes an argument, and the argument-less version is marked as obsolete. The macro is invoked with the `noyywrap` option, as recommended in the documentation. Also, the AX_PTHREAD macro makes use of the $as_echo built-in shell variable which no longer exists in 2.70. A patch was submitted to the GNU Autoconf archive in March, but there have been no signs of life given since then [2]. As such, our local copy is updated to the latest version and the patch (which looks fairly straight-forward / safe) is applied. This should minimize changes once we go back to an "official" version of the macro. [1] https://lwn.net/Articles/839395/ [2] https://savannah.gnu.org/patch/?9906 Signed-off-by: Jérémie Galarneau Reviewed-by: Michael Jeanson Change-Id: Ie949de73442770f60cbef55300265205527731c6 ---