build: doc: Allow to specify whether to produce man pages, html, neither or both

New default action is: run doxygen (if installed) to produce man pages only.
This adds 124 KB to the build tree (and to the install tree, after
`make install`).
For finer control of built documentation, the old --with-doxygen configure
option is removed. Instead there are 2 new options:
  --enable-html-doc      # +1160 KB
  --disable-man-pages    #  -124 KB
If doxygen is not installed, configure outputs a warning that man pages will not
be built. configure --disable-man-pages avoids this warning.
After --enable-html-doc
 - `make install` installs built pages in htmldir instead of just leaving them
   in the build tree.
 - If the 'dot' program is not installed, configure outputs a warning that
   interactive diagrams will be missing and to install graphviz to get them.
   (There is an interactive diagram at the head of some modules, e.g.
    User-space network packet buffer).

[ a few configure.ac edits to keep it in sync with libnetfilter_log --pablo]

Signed-off-by: Duncan Roe <duncan_roe@optusnet.com.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 44 insertions, 16 deletions

diff --git a/configure.ac b/configure.ac
index 4721eeb..416d58b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,6 +13,22 @@ m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
 dnl kernel style compile messages
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
+AC_ARG_ENABLE([html-doc],
+	      AS_HELP_STRING([--enable-html-doc], [Enable html documentation]),
+	      [], [enable_html_doc=no])
+AM_CONDITIONAL([BUILD_HTML], [test "$enable_html_doc" = yes])
+AS_IF([test "$enable_html_doc" = yes],
+	[AC_SUBST(GEN_HTML, YES)],
+	[AC_SUBST(GEN_HTML, NO)])
+
+AC_ARG_ENABLE([man-pages],
+	      AS_HELP_STRING([--disable-man-pages], [Disable man page documentation]),
+	      [], [enable_man_pages=yes])
+AM_CONDITIONAL([BUILD_MAN], [test "$enable_man_pages" = yes])
+AS_IF([test "$enable_man_pages" = yes],
+	[AC_SUBST(GEN_MAN, YES)],
+	[AC_SUBST(GEN_MAN, NO)])
+
 AC_PROG_CC
 AM_PROG_CC_C_O
 AC_DISABLE_STATIC
@@ -29,19 +45,11 @@ dnl Dependencies
 PKG_CHECK_MODULES([LIBNFNETLINK], [libnfnetlink >= 0.0.41])
 PKG_CHECK_MODULES([LIBMNL], [libmnl >= 1.0.3])
 
-dnl Output the makefiles
-AC_CONFIG_FILES([Makefile src/Makefile utils/Makefile examples/Makefile
-	libnetfilter_queue.pc
-	include/Makefile include/libnetfilter_queue/Makefile
-	doxygen/Makefile doxygen/doxygen.cfg
-	include/linux/Makefile include/linux/netfilter/Makefile])
-
-AC_ARG_WITH([doxygen], [AS_HELP_STRING([--with-doxygen],
-	    [create doxygen documentation])],
-	    [with_doxygen="$withval"], [with_doxygen=yes])
+AS_IF([test "$enable_man_pages" = no -a "$enable_html_doc" = no],
+      [with_doxygen=no], [with_doxygen=yes])
 
 AS_IF([test "x$with_doxygen" != xno], [
-	AC_CHECK_PROGS([DOXYGEN], [doxygen])
+	AC_CHECK_PROGS([DOXYGEN], [doxygen], [""])
 	AC_CHECK_PROGS([DOT], [dot], [""])
 	AS_IF([test "x$DOT" != "x"],
 	      [AC_SUBST(HAVE_DOT, YES)],
@@ -52,12 +60,22 @@ AM_CONDITIONAL([HAVE_DOXYGEN], [test -n "$DOXYGEN"])
 AS_IF([test "x$DOXYGEN" = x], [
 	AS_IF([test "x$with_doxygen" != xno], [
 		dnl Only run doxygen Makefile if doxygen installed
-		AC_MSG_WARN([Doxygen not found - continuing without Doxygen support])
-		with_doxygen=no
+		AC_MSG_WARN([Doxygen not found - not building documentation])
+		enable_html_doc=no
+		enable_man_pages=no
 	])
 ])
+
+dnl Output the makefiles
+AC_CONFIG_FILES([Makefile src/Makefile utils/Makefile examples/Makefile
+	libnetfilter_queue.pc
+	include/Makefile include/libnetfilter_queue/Makefile
+	doxygen/Makefile doxygen/doxygen.cfg
+	include/linux/Makefile include/linux/netfilter/Makefile])
+
 AC_OUTPUT
 
 echo "
 libnetfilter_queue configuration:
-  doxygen:                      ${with_doxygen}"
+man pages:                      ${enable_man_pages}
+html docs:                      ${enable_html_doc}"
diff --git a/doxygen/Makefile.am b/doxygen/Makefile.am
index 5a7fdd5..c6eeed7 100644
--- a/doxygen/Makefile.am
+++ b/doxygen/Makefile.am
@@ -14,7 +14,9 @@ doxyfile.stamp: $(doc_srcs) Makefile
 	rm -rf html man
 	doxygen doxygen.cfg >/dev/null
 
+if BUILD_MAN
 	$(abs_top_srcdir)/doxygen/build_man.sh
+endif
 
 	touch doxyfile.stamp
 
@@ -24,13 +26,20 @@ all-local: doxyfile.stamp
 clean-local:
 	rm -rf man html
 install-data-local:
+if BUILD_MAN
 	mkdir -p $(DESTDIR)$(mandir)/man3
 	cp --no-dereference --preserve=links,mode,timestamps man/man3/*.3\
 	  $(DESTDIR)$(mandir)/man3/
+endif
+if BUILD_HTML
+	mkdir  -p $(DESTDIR)$(htmldir)
+	cp  --no-dereference --preserve=links,mode,timestamps html/*\
+		$(DESTDIR)$(htmldir)
+endif
 
 # make distcheck needs uninstall-local
 uninstall-local:
-	rm -r $(DESTDIR)$(mandir) man html doxyfile.stamp
+	rm -rf $(DESTDIR)$(mandir) man html doxyfile.stamp $(DESTDIR)$(htmldir)
 endif
 
 EXTRA_DIST = build_man.sh
diff --git a/doxygen/doxygen.cfg.in b/doxygen/doxygen.cfg.in
index 99b5c90..14bd0cf 100644
--- a/doxygen/doxygen.cfg.in
+++ b/doxygen/doxygen.cfg.in
@@ -21,7 +21,8 @@ ALPHABETICAL_INDEX     = NO
 SEARCHENGINE           = NO
 GENERATE_LATEX         = NO
 LATEX_CMD_NAME         = latex
-GENERATE_MAN           = YES
+GENERATE_MAN           = @GEN_MAN@
+GENERATE_HTML          = @GEN_HTML@
 MAN_LINKS              = YES
 HAVE_DOT               = @HAVE_DOT@
 DOT_TRANSPARENT        = YES