[cairo] [PATCH v2 1/3] configure.ac: Quell warnings about AM_PROG_AR when using automake 1.12

[Bryce W. Harrington]

Without this, autogen.sh issues warnings like:

  /usr/share/automake-1.14/am/ltlibrary.am: warning: 'libcairoboilerplate_cxx.la': linking libtool libraries using a non-POSIX
  /usr/share/automake-1.14/am/ltlibrary.am: archiver requires 'AM_PROG_AR' in 'configure.ac'
  boilerplate/Makefile.am:18:   while processing Libtool library 'libcairoboilerplate_cxx.la'

AM_PROG_AR was introduced in automake 1.11.2.  As per the docs for
AM_PROG_AR, it is supposed to be included when the archiver ('ar') is
used, but prior to automake 1.12 the warning was only shown iff
-Wextra-portability was specified.  automake 1.12 introduced a change
that includes -Wextra-portability when -Wall is specified.

For further discussion of the issue, see:

  http://debbugs.gnu.org/cgi/bugreport.cgi?bug=11401
  http://lists.gnu.org/archive/html/automake/2012-05/msg00014.html

Signed-off-by: Bryce Harrington <b.harrington at samsung.com>
---
 configure.ac | 1 +
 1 file changed, 1 insertion(+)

diff --git a/configure.ac b/configure.ac
index 04479ff..9f38d30 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,6 +15,7 @@ AC_CHECK_HEADERS([unistd.h sys/ioctl.h])
 
 AM_INIT_AUTOMAKE([1.11 foreign -Wall no-define no-dist-gzip dist-xz])
 AM_SILENT_RULES([yes])
+m4_ifdef([AM_PROG_AR], [AM_PROG_AR]) dnl Workaround for Automake 1.12
 
 # Initialize libtool
 LT_PREREQ([2.2])
-- 
1.9.1