autoconf: Add information about the --x-* options to --help output

Try to tell the user that the --x-* options are only used when the X
libraries can't be found by pkg-config.

diff --git a/configure.ac b/configure.ac
index dbd81909f1520707ae69d3055025326a5a704fbb..ec8b5ddbc7505e1a33cf125572c80c6414b29db9 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -456,7 +456,7 @@ esac
 
 dnl
 dnl Find out if X is available. The variable have_x is set if libX11 is
-dnl to mimic AC_PATH_XTRA.
+dnl found to mimic AC_PATH_XTRA.
 dnl
 if test -n "$PKG_CONFIG"; then
     AC_MSG_CHECKING([pkg-config files for X11 are available])
@@ -475,6 +475,12 @@ if test "$x11_pkgconfig" = no; then
     AC_PATH_XTRA
 fi
 
+dnl Try to tell the user that the --x-* options are only used when
+dnl pkg-config is not available. This must be right after AC_PATH_XTRA.
+m4_divert_once([HELP_BEGIN],
+[These options are only used when the X libraries cannot be found by the
+pkg-config utility.])
+
 dnl We need X for xlib and dri, so bomb now if it's not found
 case "$mesa_driver" in
 xlib|dri)