build: add autotools support for the 'doc' subdir

'nft' documentation is originally contained in the XML file 'doc/nft.xml'.
Processing this file with the proper tools we can obtain a PDF document,
 'nft.pdf', and a unix man page, 'nft.8'.

To produce the PDF we need the tool 'dblatex' (current release
pypi.python.org/pypi/dblatex/0.3.5).

To produce the man page we use the tool 'docbook2man'; it is part of the
package 'docbook2X' (docbook2x.sourceforge.net). On some linux
distributions the tool can have slightly different names as 'docbook2x-man'
or 'db2x_docbook2man' so we search for all three names and use the first
one found and issue the command:

 # ${DB2MAN} --xinclude $<

Signed-off-by: Giorgio Dal Molin <giorgio.nicole@arcor.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 38 insertions, 42 deletions

diff --git a/Makefile.am b/Makefile.am
index 8d301f62..b7fdc42c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,5 @@
 ACLOCAL_AMFLAGS	= -I m4
 
 SUBDIRS = 	src	\
-		include
+		include	\
+		doc
diff --git a/configure.ac b/configure.ac
index e71dcedf..7bbd86ef 100644
--- a/configure.ac
+++ b/configure.ac
@@ -49,29 +49,24 @@ then
         exit 1
 fi
 
-AC_CHECK_PROG(CONFIG_MAN1, [docbook2x-man], [y], [n])
-if test "$CONFIG_MAN1" == "y"
-then
-	CONFIG_MAN=y
-	DB2MAN=docbook2x-man
-else
-	AC_CHECK_PROG(CONFIG_MAN2, [db2x_docbook2man], [y], [n])
-	if test "$CONFIG_MAN2" == "y"
-	then
-		CONFIG_MAN=y
-		DB2MAN=db2x_docbook2man
-	else
-		AC_MSG_WARN([docbookx2-man/db2x_docbook2man not found, no manpages will be built])
-	fi
-fi
-AC_SUBST(CONFIG_MAN)
+AC_CHECK_PROG(DOCBOOK2X_MAN, [docbook2x-man], [docbook2x-man], [no])
+AC_CHECK_PROG(DOCBOOK2MAN, [docbook2man], [docbook2man], [no])
+AC_CHECK_PROG(DB2X_DOCBOOK2MAN, [db2x_docbook2man], [db2x_docbook2man], [no])
+AS_IF([test "$DOCBOOK2X_MAN" != "no"], [DB2MAN="$DOCBOOK2X_MAN"],
+	[AS_IF([test "$DOCBOOK2MAN" != "no"], [DB2MAN="$DOCBOOK2MAN"],
+		[AS_IF([test "$DB2X_DOCBOOK2MAN" != "no"], [DB2MAN="$DB2X_DOCBOOK2MAN"],
+			[AC_MSG_WARN([docbookx2-man/db2x_docbook2man not found, no manpages will be built])]
+		)]
+	)]
+)
 AC_SUBST(DB2MAN)
+AM_CONDITIONAL([BUILD_MAN], [test -n "$DB2MAN"])
 
-AC_CHECK_PROG(CONFIG_PDF, dblatex, y, n)
-if test "$CONFIG_PDF" != "y"
-then
-	AC_MSG_WARN([dblatex not found, no PDF manpages will be built])
-fi
+AC_CHECK_PROG(DBLATEX, [dblatex], [found], [no])
+AS_IF([test "$DBLATEX" == "no"],
+	[AC_MSG_WARN([dblatex not found, no PDF manpages will be built])]
+)
+AM_CONDITIONAL([BUILD_PDF], [test "$DBLATEX" == "found"])
 
 # Checks for libraries.
 PKG_CHECK_MODULES([LIBMNL], [libmnl >= 1.0.3])
@@ -125,6 +120,7 @@ AC_CONFIG_FILES([					\
 		include/Makefile			\
 		include/linux/Makefile			\
 		include/linux/netfilter/Makefile	\
+		doc/Makefile				\
 		])
 AC_OUTPUT
 
diff --git a/doc/Makefile.am b/doc/Makefile.am
new file mode 100644
index 00000000..a92de7f5
--- /dev/null
+++ b/doc/Makefile.am
@@ -0,0 +1,19 @@
+if BUILD_MAN
+man_MANS = nft.8
+endif
+
+if BUILD_PDF
+pdf_DATA = nft.pdf
+endif
+
+pdfdir=${docdir}/pdf
+
+.xml.pdf:
+	${AM_V_GEN}dblatex -q -t pdf -o $@ $<
+
+.xml.8:
+	${AM_V_GEN}${DB2MAN} --xinclude $<
+
+EXTRA_DIST = nft.xml
+
+CLEANFILES = nft.pdf nft.8 *~
diff --git a/doc/Makefile.in b/doc/Makefile.in
deleted file mode 100644
index 1ec856c9..00000000
--- a/doc/Makefile.in
+++ /dev/null
@@ -1,20 +0,0 @@
-mandocs-@CONFIG_MAN@	+= doc/nft.8
-pdfdocs-@CONFIG_PDF@	+= doc/nft.pdf
-
-all:		$(mandocs-y) $(pdfdocs-y)
-clean:
-		@echo -e "  CLEAN\t\tdoc"
-		$(RM) $(mandocs-y) $(pdfdocs-y)
-
-install:	$(mandocs-y) $(pdfdocs-y)
-		@echo -e "  INSTALL\tdoc"
-		if test -n "$(mandocs-y)"; then \
-			$(MKDIR_P) $(DESTDIR)/${mandir}/man8 ;\
-			$(INSTALL) -m 755 -p $(mandocs-y) \
-					$(DESTDIR)/${mandir}/man8/ ;\
-		fi
-		if test -n "$(pdfdocs-y)"; then \
-			$(MKDIR_P) $(DESTDIR)/${pdfdir} ;\
-			$(INSTALL) -m 755 -p $(pdfdocs-y) \
-					$(DESTDIR)/${pdfdir}/ ;\
-		fi