+ $(MAKE) -C $@
+
+doc_inner:
+ $(MAKE) -C $@
+
+clean: clean_src clean_gtags clean_test clean_doc clean_doc_inner
+
+clean_src:
+ @$(MAKE) -sC src clean
+
+clean_gtags:
+ @$(RMF) GPATH GRTAGS GSYMS GTAGS
+
+clean_test:
+ @$(MAKE) -sC test clean
+
+clean_doc:
+ @$(MAKE) -sC doc clean