kbuild: add GNU GLOBAL tags generation

GNU GLOBAL (http://www.gnu.org/software/global/) is a source code tagging system
It is really cheap to support it in kbuild system.

Signed-off-by: Jianbin Kang <kjbmail@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

2 files changed, 13 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index 6619720f50dd..d4a9d5b81a14 100644
--- a/Makefile
+++ b/Makefile
@@ -420,7 +420,7 @@ endif
 # of make so .config is not included in this case either (for *config).
 
 no-dot-config-targets := clean mrproper distclean \
-                         cscope TAGS tags help %docs check% coccicheck \
+                         cscope gtags TAGS tags help %docs check% coccicheck \
                          include/linux/version.h headers_% \
                          kernelversion %src-pkg
 
@@ -1134,7 +1134,7 @@ CLEAN_FILES +=	vmlinux System.map \
 MRPROPER_DIRS  += include/config usr/include include/generated
 MRPROPER_FILES += .config .config.old .version .old_version             \
                   include/linux/version.h                               \
-                  Module.symvers tags TAGS cscope*
+                  Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
 
 # clean - Delete most, but leave enough to build external modules
 #
@@ -1221,6 +1221,7 @@ help:
         @echo  '  modules_prepare - Set up for building external modules'
         @echo  '  tags/TAGS       - Generate tags file for editors'
         @echo  '  cscope          - Generate cscope index'
+        @echo  '  gtags           - Generate GNU GLOBAL index'
         @echo  '  kernelrelease   - Output the release version string'
         @echo  '  kernelversion   - Output the version stored in Makefile'
         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
@@ -1379,7 +1380,7 @@ clean: $(clean-dirs)
 quiet_cmd_tags = GEN     $@
       cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
 
-tags TAGS cscope: FORCE
+tags TAGS cscope gtags: FORCE
         $(call cmd,tags)
 
 # Scripts to check various things for consistency
diff --git a/scripts/tags.sh b/scripts/tags.sh
index e091db312ddb..5d17c71a8161 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -114,6 +114,11 @@ docscope()
         cscope -b -f cscope.out
 }
 
+dogtags()
+{
+        all_sources | gtags -f -
+}
+
 exuberant()
 {
         all_sources | xargs $1 -a                               \
@@ -185,6 +190,10 @@ case "$1" in
                 docscope
                 ;;
 
+        "gtags")
+                dogtags
+                ;;
+
         "tags")
                 rm -f tags
                 xtags ctags