setlocalversion: Include post Linus git tags in LOCALVERSION_AUTO

The localversion detection script assumes that if there's a tag
describing the commit the toplevel Makefile would indicate what
that version is. This is usually true because Linus tags a commit
and updates the Makefile at the same time to make a release.
Unfortunately this means that any other tags made on the kernel
are ignored and not used in the localversion output.

For example, consider Linus tagged v3.0-rc5 and I have worked on
a bunch of commits based off that tag and then tagged my branch
with another tag called "changes-for-linus". Ideally I would like
to see the kernel is based off v3.0-rc5 at the tag
changes-for-linus. When localversion detects the version it
assumes that the kernel is v3.0-rc5 because a tag is on the
current commit but it doesn't confirm that the tag matches the
Makefile. It then proceeds to throw away everything after the
patch level and git commit hash from git describe output so we
lost the tag changes-for-linus and are left with:

  v3.0-rc5-0003-g234ad

Instead of doing that always try to describe the tree regardless
of whether or not there is an exact match (unless we are doing
--short output and just want to put a + after the version).
Include the hash of the tag so that we get a bit more information
about the tree that was built, but be sure to throw away any tags
from Linus himself that start with v3.* so that we get output
like:

  v3.0-rc5-g1561da-linus-0003-g234ad

Change-Id: I9c4d03c61650658676f221680c61899305c6217a
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 19 insertions, 4 deletions

diff --git a/scripts/setlocalversion b/scripts/setlocalversion
index 63d91e22ed7c..43f29132a28c 100755
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -48,7 +48,20 @@ scm_version()
 
 		# If we are at a tagged commit (like "v2.6.30-rc6"), we ignore
 		# it, because this version is defined in the top level Makefile.
-		if [ -z "`git describe --exact-match 2>/dev/null`" ]; then
+		if atag="`git describe --exact-match --abbrev=0 2>/dev/null`"; then
+			# Make sure we're at the tag that matches the Makefile.
+			# If not place the hash of the tag as well for
+			# v2.6.30-rc5-g314aef
+			if [ "x$atag" != "x$VERSION" ]; then
+				# If only the short version is requested,
+				# don't bother running further git commands
+				if $short; then
+					echo "+"
+					return
+				fi
+				printf '%s%s' -g "`git show-ref -s --abbrev --tags $atag 2>/dev/null`"
+			fi
+		else
 
 			# If only the short version is requested, don't bother
 			# running further git commands
@@ -57,10 +70,12 @@ scm_version()
 				return
 			fi
 			# If we are past a tagged commit (like
-			# "v2.6.30-rc5-302-g72357d5"), we pretty print it.
+			# "v2.6.30-rc5-302-g72357d5"), we pretty print it and
+			# include the hash of any new tag on top.
 			if atag="`git describe 2>/dev/null`"; then
-				echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'
-
+				tag="`git describe --abbrev=0 2>/dev/null`"
+				commit="`echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'`"
+				printf '%s%s%s' -g "`git show-ref -s --abbrev --tags $tag 2>/dev/null`" $commit
 			# If we don't have a tag at all we print -g{commitish}.
 			else
 				printf '%s%s' -g $head