kbuild: Extend kbuild/defconfig tags support to exuberant ctags

The following patch extends kbuild/defconfig tags support to exuberant
ctags.  The previous support is only for emacs ctags/etags programs.

This patch also corrects the kconfig regex for the emacs invocation.
Previously it would miss some instances because it assumed /^config
instead of /^[ \t]*config

Signed-off-by: Aron Griffis <aron@hp.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Makefile

@@ -1273,6 +1273,31 @@ define all-defconfigs
 	$(call find-sources,'defconfig')
 endef
 
+define xtags
+	if $1 --version 2>&1 | grep -iq exuberant; then \
+	    $(all-sources) | xargs $1 -a \
+		-I __initdata,__exitdata,__acquires,__releases \
+		-I EXPORT_SYMBOL,EXPORT_SYMBOL_GPL \
+		--extra=+f --c-kinds=+px; \
+	    $(all-kconfigs) | xargs $1 -a \
+		--langdef=kconfig \
+		--language-force=kconfig \
+		--regex-kconfig='/^[[:blank:]]*config[[:blank:]]+([[:alnum:]_]+)/\1/'; \
+	    $(all-defconfigs) | xargs $1 -a \
+		--langdef=dotconfig \
+		--language-force=dotconfig \
+		--regex-dotconfig='/^#?[[:blank:]]*(CONFIG_[[:alnum:]_]+)/\1/'; \
+	elif $1 --version 2>&1 | grep -iq emacs; then \
+	    $(all-sources) | xargs $1 -a; \
+	    $(all-kconfigs) | xargs $1 -a \
+		--regex='/^[ \t]*config[ \t]+\([a-zA-Z0-9_]+\)/\1/'; \
+	    $(all-defconfigs) | xargs $1 -a \
+		--regex='/^#?[ \t]?\(CONFIG_[a-zA-Z0-9_]+\)/\1/'; \
+	else \
+	    $(all-sources) | xargs $1 -a; \
+	fi
+endef
+
 quiet_cmd_cscope-file = FILELST cscope.files
       cmd_cscope-file = (echo \-k; echo \-q; $(all-sources)) > cscope.files
 
@@ -1286,31 +1311,16 @@ cscope: FORCE
 quiet_cmd_TAGS = MAKE   $@
 define cmd_TAGS
 	rm -f $@; \
-	ETAGSF=`etags --version | grep -i exuberant >/dev/null &&     \
-                echo "-I __initdata,__exitdata,__acquires,__releases  \
-                      -I EXPORT_SYMBOL,EXPORT_SYMBOL_GPL              \
-                      --extra=+f --c-kinds=+px"`;                     \
-                $(all-sources) | xargs etags $$ETAGSF -a;             \
-	if test "x$$ETAGSF" = x; then                                 \
-		$(all-kconfigs) | xargs etags -a                      \
-		--regex='/^config[ \t]+\([a-zA-Z0-9_]+\)/\1/';        \
-		$(all-defconfigs) | xargs etags -a                    \
-		--regex='/^#?[ \t]?\(CONFIG_[a-zA-Z0-9_]+\)/\1/';     \
-	fi
+	$(call xtags,etags)
 endef
 
 TAGS: FORCE
 	$(call cmd,TAGS)
 
-
 quiet_cmd_tags = MAKE   $@
 define cmd_tags
 	rm -f $@; \
-	CTAGSF=`ctags --version | grep -i exuberant >/dev/null &&     \
-                echo "-I __initdata,__exitdata,__acquires,__releases  \
-                      -I EXPORT_SYMBOL,EXPORT_SYMBOL_GPL              \
-                      --extra=+f --c-kinds=+px"`;                     \
-                $(all-sources) | xargs ctags $$CTAGSF -a
+	$(call xtags,ctags)
 endef
 
 tags: FORCE