[yelp/wip/kill-gnome-common: 12/16] Use AX_REQUIRE_DEFINED to check for M4 macros

[David King <davidk src gnome org>]

commit b03f78622e3f1edb0a5e84219ee219a917238dce
Author: David King <amigadave amigadave com>
Date:   Wed Jan 28 13:59:01 2015 +0000

    Use AX_REQUIRE_DEFINED to check for M4 macros
    
    https://wiki.gnome.org/Projects/GnomeCommon/Migration

 configure.ac             |    2 ++
 m4/ax_require_defined.m4 |   37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index afd59b4..530855d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -60,6 +60,7 @@ if test "x$GCC" = "xyes"; then
 fi
 
 # i18n stuff
+AX_REQUIRE_DEFINED([IT_PROG_INTLTOOL])
 IT_PROG_INTLTOOL([0.41.0])
 
 ALL_LINGUAS="`grep -v '^#' "$srcdir/po/LINGUAS" | tr '\n' ' '`"
@@ -167,6 +168,7 @@ AC_SUBST([AM_CPPFLAGS])
 AC_SUBST([AM_CFLAGS])
 AC_SUBST([AM_LDFLAGS])
 
+AX_REQUIRE_DEFINED([GTK_DOC_CHECK])
 GTK_DOC_CHECK([1.13],[--flavour no-tmpl])
 
 AC_CONFIG_FILES([
diff --git a/m4/ax_require_defined.m4 b/m4/ax_require_defined.m4
new file mode 100644
index 0000000..cae1111
--- /dev/null
+++ b/m4/ax_require_defined.m4
@@ -0,0 +1,37 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_require_defined.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_REQUIRE_DEFINED(MACRO)
+#
+# DESCRIPTION
+#
+#   AX_REQUIRE_DEFINED is a simple helper for making sure other macros have
+#   been defined and thus are available for use.  This avoids random issues
+#   where a macro isn't expanded.  Instead the configure script emits a
+#   non-fatal:
+#
+#     ./configure: line 1673: AX_CFLAGS_WARN_ALL: command not found
+#
+#   It's like AC_REQUIRE except it doesn't expand the required macro.
+#
+#   Here's an example:
+#
+#     AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
+#
+# LICENSE
+#
+#   Copyright (c) 2014 Mike Frysinger <vapier gentoo org>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 1
+
+AC_DEFUN([AX_REQUIRE_DEFINED], [dnl
+  m4_ifndef([$1], [m4_fatal([macro ]$1[ is not defined; is a m4 file missing?])])
+])dnl AX_REQUIRE_DEFINED