Build Doxygen documentation for make all.

This depends on GNU Make for the wildcard dependency on all the source
files in dbus/. If anyone objects very strongly to this, I'd welcome
suggestions of a more portable way to do this.

configure.in

@@ -14,7 +14,7 @@ AC_LIBTOOL_RC
 
 AC_CONFIG_MACRO_DIR([m4])
 
-AM_INIT_AUTOMAKE([1.9 tar-ustar])
+AM_INIT_AUTOMAKE([1.9 tar-ustar -Wno-portability])
 AM_CONFIG_HEADER(config.h)
 
 # Honor aclocal flags

doc/Makefile.am

@@ -19,7 +19,7 @@ HTML_FILES=					\
 	dbus-tutorial.html
 
 if DBUS_XML_DOCS_ENABLED
-all-local: $(HTML_FILES)
+all-local:: $(HTML_FILES)
 
 EXTRA_DIST += $(HTML_FILES)
 
@@ -37,5 +37,18 @@ dbus-faq.html: dbus-faq.xml
 
 endif
 
+if DBUS_DOXYGEN_DOCS_ENABLED
+# Use the index as a proxy for the entire doc tree.
+DOXYGEN_HTML_INDEX = api/html/index.html
+
+all-local:: $(DOXYGEN_HTML_INDEX)
+
+$(DOXYGEN_HTML_INDEX): $(wildcard $(top_srcdir)/dbus/*.[ch])
+	$(AM_V_GEN)cd $(top_builddir) && doxygen Doxyfile
+endif
+
+clean-local:
+	rm -rf api
+
 maintainer-clean-local:
 	rm -f $(HTML_FILES)