tags and cscope support really belongs in a shell script
as they do not benefit from the make functionality.

Moving the support to a shell script has several benefits:
- The readability of the code has increased a lot
- More people is able to extend the tags support
- We see less changes to the top-level Makefile

The shell script version includes improvements from:
Alexey Dobriyan <adobriyan@gmail.com> (jump to kconfig symbols)
Alexey Dobriyan <adobriyan@gmail.com> (drop ./ in paths)
Ian Campbell <ijc@hellion.org.uk> (simplified find algorithms)

This version has a few caveats:
=> It does not support ALLSOURCE_ARCHS
   - it is easy to add if it is really used
=> It assumes all archs have moved to arch/$ARCH/include
   - until that happens we have a few additional hits in the archs

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Tested-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/Makefile b/Makefile
index 3a6ac68..be462cf 100644
--- a/Makefile
+++ b/Makefile
@@ -1409,123 +1409,12 @@
 
 # Generate tags for editors
 # ---------------------------------------------------------------------------
+quiet_cmd_tags = GEN     $@
+      cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
 
-#We want __srctree to totally vanish out when KBUILD_OUTPUT is not set
-#(which is the most common case IMHO) to avoid unneeded clutter in the big tags file.
-#Adding $(srctree) adds about 20M on i386 to the size of the output file!
-
-ifeq ($(src),$(obj))
-__srctree =
-else
-__srctree = $(srctree)/
-endif
-
-ifeq ($(ALLSOURCE_ARCHS),)
-ifeq ($(ARCH),um)
-ALLINCLUDE_ARCHS := $(ARCH) $(SUBARCH)
-else
-ALLINCLUDE_ARCHS := $(SRCARCH)
-endif
-else
-#Allow user to specify only ALLSOURCE_PATHS on the command line, keeping existing behaviour.
-ALLINCLUDE_ARCHS := $(ALLSOURCE_ARCHS)
-endif
-
-ALLSOURCE_ARCHS := $(SRCARCH)
-
-define find-sources
-        ( for arch in $(ALLSOURCE_ARCHS) ; do \
-	       find $(__srctree)arch/$${arch} $(RCS_FIND_IGNORE) \
-		    -wholename $(__srctree)arch/$${arch}/include/asm -type d -prune \
-	            -o -name $1 -print; \
-	  done ; \
-	  find $(__srctree)security/selinux/include $(RCS_FIND_IGNORE) \
-	       -name $1 -print; \
-	  find $(__srctree)include $(RCS_FIND_IGNORE) \
-	       \( -name config -o -name 'asm-*' \) -prune \
-	       -o -name $1 -print; \
-	  for arch in $(ALLINCLUDE_ARCHS) ; do \
-	       test -e $(__srctree)include/asm-$${arch} && \
-                 find $(__srctree)include/asm-$${arch} $(RCS_FIND_IGNORE) \
-	            -name $1 -print; \
-	       test -e $(__srctree)arch/$${arch}/include/asm && \
-	         find $(__srctree)arch/$${arch}/include/asm $(RCS_FIND_IGNORE) \
-	            -name $1 -print; \
-	  done ; \
-	  find $(__srctree)include/asm-generic $(RCS_FIND_IGNORE) \
-	       -name $1 -print; \
-	  find $(__srctree) $(RCS_FIND_IGNORE) \
-	       \( -name include -o -name arch -o -name '.tmp_*' \) -prune -o \
-	       -name $1 -print; \
-	  )
-endef
-
-define all-sources
-	$(call find-sources,'*.[chS]')
-endef
-define all-kconfigs
-	$(call find-sources,'Kconfig*')
-endef
-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 __read_mostly,____cacheline_aligned,____cacheline_aligned_in_smp,____cacheline_internodealigned_in_smp \
-		-I EXPORT_SYMBOL,EXPORT_SYMBOL_GPL \
-		--extra=+f --c-kinds=+px \
-		--regex-asm='/^ENTRY\(([^)]*)\).*/\1/'; \
-	    $(all-kconfigs) | xargs $1 -a \
-		--langdef=kconfig \
-		--language-force=kconfig \
-		--regex-kconfig='/^[[:blank:]]*(menu|)config[[:blank:]]+([[:alnum:]_]+)/\2/'; \
-	    $(all-defconfigs) | xargs -r $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]*\(\(menu\)*config\)[ \t]+\([a-zA-Z0-9_]+\)/\3/'; \
-	    $(all-defconfigs) | xargs -r $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
-
-quiet_cmd_cscope = MAKE    cscope.out
-      cmd_cscope = cscope -b -f cscope.out
-
-cscope: FORCE
-	$(call cmd,cscope-file)
-	$(call cmd,cscope)
-
-quiet_cmd_TAGS = MAKE   $@
-define cmd_TAGS
-	rm -f $@; \
-	$(call xtags,etags)
-endef
-
-TAGS: FORCE
-	$(call cmd,TAGS)
-
-quiet_cmd_tags = MAKE   $@
-define cmd_tags
-	rm -f $@; \
-	$(call xtags,ctags)
-endef
-
-tags: FORCE
+tags TAGS cscope: FORCE
 	$(call cmd,tags)
 
-
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------