From ce75f5d34e56d7e7e4139da1be2f8d8f6c872eeb Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Wed, 8 Feb 2012 20:43:30 +0100
Subject: [PATCH] build system: Check for a2x and xsltproc.

If these tools are not found, don't try to build the documentation.
---
 Makefile.am     |  5 ++++-
 configure.ac    | 27 +++++++++++++++++++++++++++
 doc/Makefile.am |  2 +-
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 76a1016..3fab3fa 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,7 @@
-SUBDIRS = doc src
+SUBDIRS = src
+if BUILD_DOCUMENTATION
+SUBDIRS += doc
+endif
 
 EXTRA_DIST = autogen.sh version-gen.sh
 
diff --git a/configure.ac b/configure.ac
index 715639b..5f0be65 100644
--- a/configure.ac
+++ b/configure.ac
@@ -193,6 +193,26 @@ AC_SUBST([STRICT_CFLAGS])
 
 AC_CHECK_HEADERS(libgen.h)
 
+dnl Check for dependencies.
+build_documentation="yes"
+
+have_xsltproc="yes"
+AC_PATH_PROG([XSLTPROC], [xsltproc])
+if test "x$XSLTPROC" = "x"; then
+       have_xsltproc="no"
+       build_documentation="no (missing xsltproc)"
+fi
+
+have_a2x="yes"
+AC_PATH_PROG([A2X], [a2x])
+if test "x$A2X" = "x"; then
+       have_a2x="no"
+       build_documentation="no (missing a2x)"
+fi
+AC_SUBST([A2X])
+
+AM_CONDITIONAL([BUILD_DOCUMENTATION], test "x$build_documentation" = "xyes")
+
 AC_CONFIG_FILES([Makefile doc/Makefile src/Makefile])
 AC_OUTPUT
 
@@ -208,6 +228,13 @@ Configuration summary:
   package version: $PACKAGE_VERSION
   build date: `date --utc '+%F %T'` (UTC)
 
+  Tools:
+    AsciiDoc (a2x): . . . . . . $have_a2x
+    xsltproc: . . . . . . . . . $have_xsltproc
+
+  Features:
+    documentation:  . . . . . . $build_documentation
+
 This package is maintained by $PACKAGE_MAINTAINER.
 Please report bugs to $PACKAGE_BUGREPORT.
 
diff --git a/doc/Makefile.am b/doc/Makefile.am
index aca1d7e..f25dab5 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -6,7 +6,7 @@ man_MANS = fb.1
 fb.1: fb.txt ../version
 
 .txt.1:
-	a2x -d manpage -f manpage \
+	@A2X@ -d manpage -f manpage \
 		-apackage_version=$(PACKAGE_VERSION) \
 		-abuild_date="$$( date --utc '+%F' )" \
 		$<
-- 
2.30.2