[gtk+] Deprecate GTK_CHECK_BACKEND in favour of PKG_CHECK_MODULES

[Simon McVittie <smcv src gnome org>]

commit d975cd5baa119bd72c8cadd11c589d076c753fa1
Author: Simon McVittie <smcv debian org>
Date:   Wed Aug 6 11:23:53 2014 +0100

    Deprecate GTK_CHECK_BACKEND in favour of PKG_CHECK_MODULES
    
    This is easy to do with pkg-config too.
    
    Bug: https://bugzilla.gnome.org/show_bug.cgi?id=641638
    Bug-Debian: https://bugs.debian.org/756476
    Reviewed-by: Matthias Clasen

 m4macros/gtk-3.0.m4 |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/m4macros/gtk-3.0.m4 b/m4macros/gtk-3.0.m4
index 274cd32..d9b0a2d 100644
--- a/m4macros/gtk-3.0.m4
+++ b/m4macros/gtk-3.0.m4
@@ -199,7 +199,7 @@ dnl GTK_CHECK_BACKEND(BACKEND-NAME [, MINIMUM-VERSION [, ACTION-IF-FOUND [, ACTI
 dnl   Tests for BACKEND-NAME in the GTK targets list
 dnl
 AC_DEFUN([GTK_CHECK_BACKEND],
-[
+[m4_warn([obsolete], [GTK_CHECK_BACKEND is deprecated, use PKG_CHECK_MODULES([GTK_X11], [gtk+-x11-3.0]) or 
similar instead])
   pkg_config_args=ifelse([$1],,gtk+-3.0, gtk+-$1-3.0)
   min_gtk_version=ifelse([$2],,3.0.0,$2)
   pkg_config_args="$pkg_config_args >= $min_gtk_version"