[PATCH util-macros] XORG_WITH_XSLTPROC: add XSLT processor command line tool

[Gaetan Nadon]

The primary use will be for DocBook/XML cross links database generation.

XSLT (Extensible Stylesheet Language Transformations) is a declarative,
XML-based language used for the transformation of XML documents.
The xsltproc command line tool is for applying XSLT stylesheets
to XML documents.

It is used under the cover by xmlto to generate html files from DocBook/XML.
The XSLT processor is often used as a standalone tool for transformations.
It should not be assumed that it is used only to work with documnetation.

Signed-off-by: Gaetan Nadon <memsize at videotron.ca>
---
 xorg-macros.m4.in |   63 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 63 insertions(+), 0 deletions(-)

diff --git a/xorg-macros.m4.in b/xorg-macros.m4.in
index c7df523..44038e1 100644
--- a/xorg-macros.m4.in
+++ b/xorg-macros.m4.in
@@ -432,6 +432,69 @@ AM_CONDITIONAL([HAVE_XMLTO_TEXT], [test $have_xmlto_text = yes])
 AM_CONDITIONAL([HAVE_XMLTO], [test "$have_xmlto" = yes])
 ]) # XORG_WITH_XMLTO
 
+# XORG_WITH_XSLTPROC([MIN-VERSION], [DEFAULT])
+# --------------------------------------------
+# Minimum version: 1.12.0
+# Minimum version for optional DEFAULT argument: 1.12.0
+#
+# XSLT (Extensible Stylesheet Language Transformations) is a declarative,
+# XML-based language used for the transformation of XML documents.
+# The xsltproc command line tool is for applying XSLT stylesheets to XML documents.
+# It is used under the cover by xmlto to generate html files from DocBook/XML.
+# The XSLT processor is often used as a standalone tool for transformations.
+# It should not be assumed that this tool is used only to work with documnetation.
+# When DEFAULT is not specified, --with-xsltproc assumes 'auto'.
+#
+# Interface to module:
+# HAVE_XSLTPROC: used in makefiles to conditionally generate documentation
+# XSLTPROC:	 returns the path of the xsltproc program found
+#		 returns the path set by the user in the environment
+# --with-xsltproc: 'yes' user instructs the module to use xsltproc
+#		  'no' user instructs the module not to use xsltproc
+# have_xsltproc: returns yes if xsltproc found in PATH or no
+#
+# If the user sets the value of XSLTPROC, AC_PATH_PROG skips testing the path.
+#
+AC_DEFUN([XORG_WITH_XSLTPROC],[
+AC_ARG_VAR([XSLTPROC], [Path to xsltproc command])
+m4_define([_defopt], m4_default([$2], [auto]))
+AC_ARG_WITH(xsltproc,
+	AS_HELP_STRING([--with-xsltproc],
+	   [Use xsltproc for the transformation of XML documents (default: ]_defopt[)]),
+	   [use_xsltproc=$withval], [use_xsltproc=]_defopt)
+m4_undefine([_defopt])
+
+if test "x$use_xsltproc" = x"auto"; then
+   AC_PATH_PROG([XSLTPROC], [xsltproc])
+   if test "x$XSLTPROC" = "x"; then
+        AC_MSG_WARN([xsltproc not found - cannot transform XML documents])
+	have_xsltproc=no
+   else
+        have_xsltproc=yes
+   fi
+elif test "x$use_xsltproc" = x"yes" ; then
+   AC_PATH_PROG([XSLTPROC], [xsltproc])
+   if test "x$XSLTPROC" = "x"; then
+        AC_MSG_ERROR([--with-xsltproc=yes specified but xsltproc not found in PATH])
+   fi
+   have_xsltproc=yes
+elif test "x$use_xsltproc" = x"no" ; then
+   if test "x$XSLTPROC" != "x"; then
+      AC_MSG_WARN([ignoring XSLTPROC environment variable since --with-xsltproc=no was specified])
+   fi
+   have_xsltproc=no
+else
+   AC_MSG_ERROR([--with-xsltproc expects 'yes' or 'no'])
+fi
+
+# Checking for minimum version is not implemented
+# but we want to keep the interface consistent with other commands
+m4_ifval([$1],[AC_MSG_WARN(Checking for MIN-VERSION is not implemented.)])
+
+AM_CONDITIONAL([HAVE_XSLTPROC], [test "$have_xsltproc" = yes])
+]) # XORG_WITH_XSLTPROC
+
+
 # XORG_WITH_ASCIIDOC([MIN-VERSION], [DEFAULT])
 # ----------------
 # Minimum version: 1.5.0
-- 
1.6.0.4