[PATCH util-macros] XORG_WITH_DOXYGEN: check for the dot graphics utility

[Gaetan Nadon]

It is part of the graphviz package and it may be used by doxygen if
the HAVE_DOT is set to "yes" in the doxygen configuration file.

The calling module handles if the tool is mandatory or not.
Doxygen will work fine without it, but no fancy graphics.

Signed-off-by: Gaetan Nadon <memsize at videotron.ca>
---
 xorg-macros.m4.in |   18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/xorg-macros.m4.in b/xorg-macros.m4.in
index b2f903e..20a0bd0 100644
--- a/xorg-macros.m4.in
+++ b/xorg-macros.m4.in
@@ -619,9 +619,10 @@ AM_CONDITIONAL([HAVE_ASCIIDOC], [test "$have_asciidoc" = yes])
 ]) # XORG_WITH_ASCIIDOC
 
 # XORG_WITH_DOXYGEN([MIN-VERSION], [DEFAULT])
-# --------------------------------
+# -------------------------------------------
 # Minimum version: 1.5.0
 # Minimum version for optional DEFAULT argument: 1.11.0
+# Minimum version for optional DOT checking: 1.18.0
 #
 # Documentation tools are not always available on all platforms and sometimes
 # not at the appropriate level. This macro enables a module to test for the
@@ -641,6 +642,7 @@ AM_CONDITIONAL([HAVE_ASCIIDOC], [test "$have_asciidoc" = yes])
 #
 AC_DEFUN([XORG_WITH_DOXYGEN],[
 AC_ARG_VAR([DOXYGEN], [Path to doxygen command])
+AC_ARG_VAR([DOT], [Path to the dot graphics utility])
 m4_define([_defopt], m4_default([$2], [auto]))
 AC_ARG_WITH(doxygen,
 	AS_HELP_STRING([--with-doxygen],
@@ -684,6 +686,20 @@ m4_ifval([$1],
             AC_MSG_ERROR([doxygen version $doxygen_version found, but $1 needed])
         fi])
 fi])
+
+dnl Check for DOT if we have doxygen. The caller decides if it is mandatory
+dnl HAVE_DOT is a variable that can be used in your doxygen.in config file:
+dnl 	HAVE_DOT = @HAVE_DOT@
+HAVE_DOT=no
+if test "x$have_doxygen" = "xyes"; then
+  AC_PATH_PROG([DOT], [dot])
+    if test "x$DOT" != "x"; then
+      HAVE_DOT=yes
+    fi
+fi
+
+AC_SUBST([HAVE_DOT])
+AM_CONDITIONAL([HAVE_DOT], [test "$HAVE_DOT" = "yes"])
 AM_CONDITIONAL([HAVE_DOXYGEN], [test "$have_doxygen" = yes])
 ]) # XORG_WITH_DOXYGEN
 
-- 
1.7.9.5