Require an exact Autoconf version.

diff --git a/ChangeLog b/ChangeLog
index d85ffee..a762760 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-11-02  Roland McGrath  <roland@hack.frob.com>
+
+       * aclocal.m4 (GLIBC_AUTOCONF_VERSION): New macro.
+       Check that AC_AUTOCONF_VERSION matches it and m4_fatal at
+       autoconf-time if not.
+       * configure.in: Remove AC_PREREQ.
+
 2012-11-02  Tulio Magno Quites Machado Filho  <tuliom@linux.vnet.ibm.com>
 
        * sysdeps/powerpc/sys/platform/ppc.h (__ppc_get_timebase): Use

diff --git a/aclocal.m4 b/aclocal.m4
index 60a5fea..3e61dc8 100644 (file)
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1,3 +1,13 @@
+dnl We require that everyone use exactly the same Autoconf version so that
+dnl the internal functions defined and used by the main configure script
+dnl match those expected by the fragments.
+m4_define([GLIBC_AUTOCONF_VERSION], [2.68])
+m4_if(m4_defn([AC_AUTOCONF_VERSION]), GLIBC_AUTOCONF_VERSION, [],
+      [m4_fatal(m4_flatten(
+Exactly version GLIBC_AUTOCONF_VERSION of Autoconf is required but you have
+m4_defn([AC_AUTOCONF_VERSION])
+), [63])])dnl
+dnl
 dnl We define the macro GLIBC_PROVIDES to do an AC_PROVIDE for each macro
 dnl which appears in configure.in before the sysdep configure scripts are run.
 dnl Each sysdep configure.in does GLIBC_PROVIDES first, to avoid any

diff --git a/configure.in b/configure.in
index 928b7b6..5e35b98 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -1,5 +1,5 @@
 dnl Process this file with autoconf to produce a configure script.
-AC_PREREQ(2.53)dnl             dnl Minimum Autoconf version required.
+dnl Note we do not use AC_PREREQ here!  See aclocal.m4 for what we use instead.
 AC_INIT([GNU C Library], [(see version.h)], [http://sourceware.org/bugzilla/], [glibc])
 AC_CONFIG_SRCDIR([include/features.h])
 AC_CONFIG_HEADERS([config.h])