build: combine handling of setting docs and man pages

Building the man pages via xsltproc requires "docbook.xsl"
which is part of docbook.

Previously, we would build the man pages solely based on
"--enable-introspection", which checks for the presence of
xsltproc, but not docbook. This can lead to build failure
when docbook is not available, but "--enable-introspection"
is given.

Instead of adding yet another configure option to fine-tune
and say "--with-docbook --disable-gtk-doc", just simplify it.

Now, documentation (both man pages and setting docs) will be generated
with "--enable-gtk-doc" and "--enable-introspection".
If the documentation is not about to be generated, pre-generated docs
will be installed if they are available. That is commonly the case
with a source tarball, but not with a git checkout.
Finally, if documentation is nither generated nor pre-generated,
no documentation will be installed *duh*.

This removes the possibility to treat man pages separate from settings
docs. Now you either generate both, install both pre-generated, or don't
get any of them.

https://bugzilla.gnome.org/show_bug.cgi?id=778551

Makefile.am

@@ -86,7 +86,7 @@ SUBDIRS = \
 	. \
 	po
 
-if BUILD_SETTING_DOCS
+if HAVE_DOCS
 
 SUBDIRS += \
 	docs/libnm \
@@ -128,7 +128,7 @@ DISTCHECK_CONFIGURE_FLAGS = \
 dist-configure-check:
 	@echo "*** 'make dist' requires '--enable-gtk-doc --enable-introspection --with-libnm-glib'. ***"
 	@false
-if !BUILD_SETTING_DOCS
+if !BUILD_DOCS
 dist_configure_check += dist-configure-check
 endif
 if !WITH_LEGACY_LIBRARIES
@@ -3953,7 +3953,7 @@ xsltproc_flags = \
 	--stringparam man.authors.section.enabled 0 \
 	--stringparam man.copyright.section.enabled 0
 
-if HAVE_INTROSPECTION
+if BUILD_DOCS
 
 man/%.1 man/%.5 man/%.7 man/%.8: man/%.xml man/common.ent
 	$(AM_V_GEN) $(XSLTPROC) --output $@ $(xsltproc_flags) http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl $<
@@ -4021,22 +4021,16 @@ uninstall-hook-man:
 
 uninstall_hook += uninstall-hook-man
 
-if HAVE_INTROSPECTION
+if HAVE_DOCS
 install_manpages = true
 man_MANS += $(man_pages)
-CLEANFILES += $(man_pages)
-if SETTING_DOCS_AVAILABLE
 man_MANS += $(man_pages_autogen)
+endif
+
+if BUILD_DOCS
+CLEANFILES += $(man_pages)
 CLEANFILES += $(man_pages_autogen)
 endif
-else
-if INSTALL_PREGEN_MANPAGES
-install_manpages = true
-man_MANS += \
-	$(man_pages) \
-	$(man_pages_autogen)
-endif
-endif
 
 dist_dependencies += $(man_pages)
 dist_dependencies += $(man_pages_autogen)

configure.ac

@@ -1089,7 +1089,7 @@ AC_DEFINE_UNQUOTED(TEST_NM_PYTHON, "$PYTHON", [Define python path for test binar
 GTK_DOC_CHECK(1.0)
 
 # check if we can build setting property documentation
-build_setting_docs=no
+build_docs=no
 if test -n "$INTROSPECTION_MAKEFILE"; then
     # If g-i is installed we know we have python, but we might not have pygobject
     if ! "$PYTHON" -c 'from gi.repository import GObject' >& /dev/null; then
@@ -1101,7 +1101,7 @@ if test -n "$INTROSPECTION_MAKEFILE"; then
 
     have_introspection=yes
     if test "$enable_gtk_doc" = "yes"; then
-        build_setting_docs=yes
+        build_docs=yes
     fi
 else
     if test "$enable_gtk_doc" = "yes"; then
@@ -1112,20 +1112,9 @@ else
     have_introspection=no
 fi
 
-# check for pre-built setting docs
-if test "$build_setting_docs" != "yes" \
-    -a -f man/nm-settings.xml \
-    -a -f man/nm-settings-keyfile.xml \
-    -a -f man/nm-settings-ifcfg-rh.xml \
-    \
-    -a -f docs/api/settings-spec.xml \
-    ; then
-    have_setting_docs=yes
-fi
-
-# check for pregenerated manpages to be installed
-install_pregen_manpages=no
-if test "$enable_gtk_doc" != "yes" \
+# check for pregenerated manpages and documentation to be installed
+use_pregen_docs=no
+if test "$build_docs" != "yes" \
     -a -f man/NetworkManager.8 \
     -a -f man/NetworkManager.conf.5 \
     -a -f man/nm-online.1 \
@@ -1136,13 +1125,18 @@ if test "$enable_gtk_doc" != "yes" \
     -a -f man/nm-settings-ifcfg-rh.5 \
     -a -f man/nm-settings-keyfile.5 \
     -a -f man/nm-settings.5 \
+    \
+    -a -f man/nm-settings.xml \
+    -a -f man/nm-settings-keyfile.xml \
+    -a -f man/nm-settings-ifcfg-rh.xml \
+    \
+    -a -f docs/api/settings-spec.xml \
     ; then
-	install_pregen_manpages=yes
+	use_pregen_docs=yes
 fi
 
-AM_CONDITIONAL(BUILD_SETTING_DOCS, test "$build_setting_docs" = "yes")
-AM_CONDITIONAL(SETTING_DOCS_AVAILABLE, test "$build_setting_docs" = "yes" -o "$have_setting_docs" = "yes")
-AM_CONDITIONAL(INSTALL_PREGEN_MANPAGES, test "$install_pregen_manpages" = "yes")
+AM_CONDITIONAL(BUILD_DOCS, test "$build_docs" = "yes")
+AM_CONDITIONAL(HAVE_DOCS, test "$build_docs" = "yes" -o "$use_pregen_docs" = "yes")
 
 AC_CONFIG_FILES([
 Makefile
@@ -1232,9 +1226,9 @@ echo "  dhcpcd-supports-ipv6: $with_dhcpcd_supports_ipv6"
 echo
 
 echo "Miscellaneous:"
-echo "  documentation: $enable_gtk_doc"
-echo "  documentation-settings: $build_setting_docs"
-echo "  introspection: $have_introspection"
+echo "  have introspection: $have_introspection"
+echo "  build documentation and manpages: $build_docs"
+echo "  install pregenerated documentation and manpages: $use_pregen_docs"
 echo "  tests: $enable_tests"
 echo "  more-asserts: $more_asserts"
 echo "  more-logging: $enable_more_logging"

docs/api/Makefile.am

@@ -5,7 +5,7 @@ XMLS = $(wildcard $(top_srcdir)/introspection/nm-*.xml)
 
 GENERATED_FILES =
 
-if SETTING_DOCS_AVAILABLE
+if BUILD_DOCS
 
 settings-spec.xml: settings-spec.xsl $(top_builddir)/libnm/nm-settings-docs.xml
 	$(AM_V_GEN) xsltproc --output $@ $^