1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0
3#
4# This scripts adds local version information from the version
5# control system git.
6#
7# If something goes wrong, send a mail the kernel build mailinglist
8# (see MAINTAINERS) and CC Nico Schottelius
9# <nico-linuxsetlocalversion -at- schottelius.org>.
10#
11#
12
13set -e
14
15usage() {
16	echo "Usage: $0 [--no-local] [srctree]" >&2
17	exit 1
18}
19
20no_local=false
21if test "$1" = "--no-local"; then
22	no_local=true
23	shift
24fi
25
26srctree=.
27if test $# -gt 0; then
28	srctree=$1
29	shift
30fi
31if test $# -gt 0 -o ! -d "$srctree"; then
32	usage
33fi
34
35try_tag() {
36	tag="$1"
37
38	# Is $tag an annotated tag?
39	if [ "$(git cat-file -t "$tag" 2> /dev/null)" != tag ]; then
40		 return
41	fi
42
43	# Is it an ancestor of HEAD, and if so, how many commits are in $tag..HEAD?
44	# shellcheck disable=SC2046 # word splitting is the point here
45	set -- $(git rev-list --count --left-right "$tag"...HEAD 2> /dev/null)
46
47	# $1 is 0 if and only if $tag is an ancestor of HEAD. Use
48	# string comparison, because $1 is empty if the 'git rev-list'
49	# command somehow failed.
50	if [ "$1" != 0 ]; then
51		return
52	fi
53
54	# $2 is the number of commits in the range $tag..HEAD, possibly 0.
55	count="$2"
56}
57
58scm_version()
59{
60	local short=false
61	local no_dirty=false
62	local tag
63
64	while [ $# -gt 0 ];
65	do
66		case "$1" in
67		--short)
68			short=true;;
69		--no-dirty)
70			no_dirty=true;;
71		esac
72		shift
73	done
74
75	cd "$srctree"
76	if test -e .scmversion; then
77		cat .scmversion
78		return
79	fi
80
81	if test -n "$(git rev-parse --show-cdup 2>/dev/null)"; then
82		return
83	fi
84
85	if ! head=$(git rev-parse --verify HEAD 2>/dev/null); then
86		return
87	fi
88
89	# mainline kernel:  6.2.0-rc5  ->  v6.2-rc5
90	# stable kernel:    6.1.7      ->  v6.1.7
91	version_tag=v$(echo "${KERNELVERSION}" | sed -E 's/^([0-9]+\.[0-9]+)\.0(.*)$/\1\2/')
92
93	# try_tag initializes count if the tag is usable.
94	count=
95
96	# If a localversion* file exists, and the corresponding
97	# annotated tag exists and is an ancestor of HEAD, use
98	# it. This is the case in linux-next.
99	if [ -n "${file_localversion#-}" ] ; then
100		try_tag "${file_localversion#-}"
101	fi
102
103	# Otherwise, if a localversion* file exists, and the tag
104	# obtained by appending it to the tag derived from
105	# KERNELVERSION exists and is an ancestor of HEAD, use
106	# it. This is e.g. the case in linux-rt.
107	if [ -z "${count}" ] && [ -n "${file_localversion}" ]; then
108		try_tag "${version_tag}${file_localversion}"
109	fi
110
111	# Otherwise, default to the annotated tag derived from KERNELVERSION.
112	if [ -z "${count}" ]; then
113		try_tag "${version_tag}"
114	fi
115
116	# If we are at the tagged commit, we ignore it because the
117	# version is well-defined. If none of the attempted tags exist
118	# or were usable, $count is still empty.
119	if [ -z "${count}" ] || [ "${count}" -gt 0 ]; then
120
121		# If only the short version is requested, don't bother
122		# running further git commands
123		if $short; then
124			echo "+"
125			return
126		fi
127
128		# If we are past the tagged commit, we pretty print it.
129		# (like 6.1.0-14595-g292a089d78d3)
130		if [ -n "${count}" ]; then
131			printf "%s%05d" "-" "${count}"
132		fi
133
134		# Add -g and exactly 12 hex chars.
135		printf '%s%.12s' -g "$head"
136	fi
137
138	if ${no_dirty}; then
139		return
140	fi
141
142	# Check for uncommitted changes.
143	# This script must avoid any write attempt to the source tree, which
144	# might be read-only.
145	# You cannot use 'git describe --dirty' because it tries to create
146	# .git/index.lock .
147	# First, with git-status, but --no-optional-locks is only supported in
148	# git >= 2.14, so fall back to git-diff-index if it fails. Note that
149	# git-diff-index does not refresh the index, so it may give misleading
150	# results.
151	# See git-update-index(1), git-diff-index(1), and git-status(1).
152	if {
153		git --no-optional-locks status -uno --porcelain 2>/dev/null ||
154		git diff-index --name-only HEAD
155	} | read dummy; then
156		printf '%s' -dirty
157	fi
158}
159
160collect_files()
161{
162	local file res=
163
164	for file; do
165		case "$file" in
166		*\~*)
167			continue
168			;;
169		esac
170		if test -e "$file"; then
171			res="$res$(cat "$file")"
172		fi
173	done
174	echo "$res"
175}
176
177if [ -z "${KERNELVERSION}" ]; then
178	echo "KERNELVERSION is not set" >&2
179	exit 1
180fi
181
182# localversion* files in the build and source directory
183file_localversion="$(collect_files localversion*)"
184if test ! "$srctree" -ef .; then
185	file_localversion="${file_localversion}$(collect_files "$srctree"/localversion*)"
186fi
187
188if ${no_local}; then
189	echo "${KERNELVERSION}$(scm_version --no-dirty)"
190	exit 0
191fi
192
193if ! test -e include/config/auto.conf; then
194	echo "Error: kernelrelease not valid - run 'make prepare' to update it" >&2
195	exit 1
196fi
197
198# version string from CONFIG_LOCALVERSION
199config_localversion=$(sed -n 's/^CONFIG_LOCALVERSION=\(.*\)$/\1/p' include/config/auto.conf | tr -d '"')
200
201# scm version string if not at the kernel version tag or at the file_localversion
202if grep -q "^CONFIG_LOCALVERSION_AUTO=y$" include/config/auto.conf; then
203	# full scm version string
204	scm_version="$(scm_version)"
205elif [ "${LOCALVERSION+set}" != "set" ]; then
206	# If the variable LOCALVERSION is not set, append a plus
207	# sign if the repository is not in a clean annotated or
208	# signed tagged state (as git describe only looks at signed
209	# or annotated tags - git tag -a/-s).
210	#
211	# If the variable LOCALVERSION is set (including being set
212	# to an empty string), we don't want to append a plus sign.
213	scm_version="$(scm_version --short)"
214fi
215
216echo "${KERNELVERSION}${file_localversion}${config_localversion}${LOCALVERSION}${scm_version}"
217