doc: Check documentation generation requirements with autoconf

Adds --enable-doc/--disable-doc, if omitted doc will only be build
if requirements are met. If explicitely enabled, configure script
will fail if requirements are not met.

4 files changed, 188 insertions, 2 deletions

diff --git a/configure.in b/configure.in
index f676371..ed059c3 100644
--- a/configure.in
+++ b/configure.in
@@ -73,6 +73,68 @@ AC_PROG_YACC
 AC_C_CONST
 AC_C_INLINE
 
+#
+# Generating the documentation
+#
+AC_ARG_ENABLE([doc],
+	      AS_HELP_STRING([--disable-doc], [Do not generate documentation]),
+	      [generate_doc="$enableval"], [generate_doc=auto])
+
+if test "x$generate_doc" != "xno"; then
+	AC_PROG_SED
+	AC_PROG_EGREP
+
+	AX_PYTHON
+
+	AC_CHECK_PROG(HAVE_DOXYGEN, [doxygen], yes, no)
+	if test "x$HAVE_DOXYGEN" = "xno" -a "x$generate_doc" = "xyes"; then
+		AC_MSG_ERROR([*** doxygen package required to generate documentation])
+	fi
+
+	link_doc=yes
+	AC_CHECK_PROG(HAVE_XMLSTARLET, [xmlstarlet], yes, no)
+	if test "x$HAVE_XMLSTARLET" = "xno"; then
+		if test "x$generate_doc" = "xyes"; then
+			AC_MSG_ERROR([*** xmlstarlet package required to generate documentation])
+		else
+			AC_MSG_WARN([*** xmlstarlet not found, linking to APi reference disabled])
+			link_doc=no
+		fi
+	fi
+
+	AC_CHECK_PROG(HAVE_ASCIIDOC, [asciidoc], yes, no)
+	if test "x$HAVE_ASCIIDOC" = "xno"; then
+		if test "x$generate_doc" = "xyes"; then
+			AC_MSG_ERROR([*** asciidoc package required to generate documentation])
+		else
+			AC_MSG_WARN([*** asciidoc not found, disabling building of guides])
+		fi
+	fi
+
+	AC_CHECK_PROG(HAVE_MSCGEN, [mscgen], yes, no)
+	if test "x$HAVE_MSCGEN" = "xno"; then
+		AC_MSG_WARN([*** mscgen not found, get it at http://www.mcternan.me.uk/mscgen/])
+		if test "x$generate_doc" = "xyes"; then
+			AC_MSG_ERROR([*** mscgen package required to generate documentation])
+		else
+			AC_MSG_WARN([*** Disabling building of guides])
+			HAVE_ASCIIDOC=no
+			HAVE_DOXYGEN=no
+		fi
+	fi
+
+	if test "x$HAVE_DOXYGEN" = "xno"; then
+		AC_MSG_WARN([*** Disabling API linking due to missing doxygen package])
+		link_doc=no
+	fi
+
+	AM_CONDITIONAL([LINK_DOC], [test "x$link_doc" = "xyes"])
+	AM_CONDITIONAL([HAVE_DOXYGEN], [test "x$HAVE_DOXYGEN" = "xyes"])
+	AM_CONDITIONAL([HAVE_ASCIIDOC], [test "x$HAVE_ASCIIDOC" = "xyes"])
+fi
+
+AM_CONDITIONAL([GENERATE_DOC], [test "x$generate_doc" != "xno"])
+
 AC_ARG_WITH([pkgconfigdir], AS_HELP_STRING([--with-pkgconfigdir=PATH],
 	[Path to the pkgconfig directory [[LIBDIR/pkgconfig]]]),
 	[pkgconfigdir="$withval"], [pkgconfigdir='${libdir}/pkgconfig'])
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 6f574dd..142dc31 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -79,20 +79,43 @@ EXTRA_DIST = \
 	images/icons/callouts/15.png
 
 %.html: %.txt
+if LINK_DOC
 	./resolve-asciidoc-refs.py $< > asciidoc.tmp
 	asciidoc $(ASCIIDOCOPTS) -o $@ asciidoc.tmp
 	./doxygen-link.py libnl.dict $@ > asciidoc.tmp
 	mv asciidoc.tmp $@
+else
+	asciidoc $(ASCIIDOCOPTS) -o $@ $<
+endif
 
 asciidoc: core.html route.html index.html
 
+link_doc:
+if LINK_DOC
+	./gen-tags.sh | ./tags2dict.sh > libnl.dict
+else
+	@echo "Warning: Linking to API reference is disabled, check configure output"
+endif
+
 api_ref:
 	doxygen Doxyfile;
-	./gen-tags.sh | ./tags2dict.sh > libnl.dict
+	$(MAKE) link_doc
 
 gendoc:
+if GENERATE_DOC
+if HAVE_DOXYGEN
 	$(MAKE) api_ref
+else
+	@echo "Warning: Building of API reference (doxygen) is disabled, check autoconf logs"
+endif
+if HAVE_ASCIIDOC
 	$(MAKE) asciidoc
+else
+	@echo "Warning: Building of asciidoc files is disabled, check autoconf logs"
+endif
+else
+	@echo "Warning: Building of documentation disabled by user or autoconf"
+endif
 
 clean-local:
 	rm -f api/* libnl.dict *.html;
diff --git a/doc/README b/doc/README
index f4d1211..0c230a2 100644
--- a/doc/README
+++ b/doc/README
@@ -1,6 +1,10 @@
 Requirements to build documentation
 
 mscgen
-asciidoc 8.6.5
+  http://www.mcternan.me.uk/mscgen/
+
 mscgen-filter-1.2
+  http://code.google.com/p/asciidoc-mscgen-filter/
+
+asciidoc 8.6.x
 doxygen
diff --git a/m4/ax_python.m4 b/m4/ax_python.m4
new file mode 100644
index 0000000..1bc9d8a
--- /dev/null
+++ b/m4/ax_python.m4
@@ -0,0 +1,97 @@
+# ===========================================================================
+#         http://www.gnu.org/software/autoconf-archive/ax_python.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PYTHON
+#
+# DESCRIPTION
+#
+#   This macro does a complete Python development environment check.
+#
+#   It recurses through several python versions (from 2.1 to 2.6 in this
+#   version), looking for an executable. When it finds an executable, it
+#   looks to find the header files and library.
+#
+#   It sets PYTHON_BIN to the name of the python executable,
+#   PYTHON_INCLUDE_DIR to the directory holding the header files, and
+#   PYTHON_LIB to the name of the Python library.
+#
+#   This macro calls AC_SUBST on PYTHON_BIN (via AC_CHECK_PROG),
+#   PYTHON_INCLUDE_DIR and PYTHON_LIB.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Michael Tindal
+#
+#   This program is free software; you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation; either version 2 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 9
+
+AC_DEFUN([AX_PYTHON],
+[AC_MSG_CHECKING(for python build information)
+AC_MSG_RESULT([])
+for python in python2.6 python2.5 python2.4 python2.3 python2.2 python2.1 python; do
+AC_CHECK_PROGS(PYTHON_BIN, [$python])
+ax_python_bin=$PYTHON_BIN
+if test x$ax_python_bin != x; then
+   AC_CHECK_LIB($ax_python_bin, main, ax_python_lib=$ax_python_bin, ax_python_lib=no)
+   AC_CHECK_HEADER([$ax_python_bin/Python.h],
+   [[ax_python_header=`locate $ax_python_bin/Python.h | sed -e s,/Python.h,,`]],
+   ax_python_header=no)
+   if test $ax_python_lib != no; then
+     if test $ax_python_header != no; then
+       break;
+     fi
+   fi
+fi
+done
+if test x$ax_python_bin = x; then
+   ax_python_bin=no
+fi
+if test x$ax_python_header = x; then
+   ax_python_header=no
+fi
+if test x$ax_python_lib = x; then
+   ax_python_lib=no
+fi
+
+AC_MSG_RESULT([  results of the Python check:])
+AC_MSG_RESULT([    Binary:      $ax_python_bin])
+AC_MSG_RESULT([    Library:     $ax_python_lib])
+AC_MSG_RESULT([    Include Dir: $ax_python_header])
+
+if test x$ax_python_header != xno; then
+  PYTHON_INCLUDE_DIR=$ax_python_header
+  AC_SUBST(PYTHON_INCLUDE_DIR)
+fi
+if test x$ax_python_lib != xno; then
+  PYTHON_LIB=$ax_python_lib
+  AC_SUBST(PYTHON_LIB)
+fi
+])dnl