patchset.sh: generate patchset from git repo

patchset.sh

#!/bin/bash
# Generate patch set in git repo. With this script, you can easily obtain a
# patchset that can be used for Linux kernel development.
#
# Copyright (C) 2022-2026 Rong Tao
#
# https://gist.github.com/Rtoax/15abb95b38ba3d4fbb5e7271f2502c61
#
set -e

readonly VERSION="v1.1.2"
readonly WHERE_AM_I=$(dirname $(realpath $0))

subject_prefix=
downer_commit=
upper_commit=

pure_diff=
no_cover_letter=

dry_run=
output_dir=patchset.patch

declare -a patch_files
declare -a abbrev_commits

. ${WHERE_AM_I}/liblog.sh

__patchset_usage__()
{
	echo -e "
${BOLD}NAME${RST}
	patchset - Generate patchset

${BOLD}SYNOPSIS${RST}
	patchset [options] -- [COMMIT1|COMMIT2|...] [FILE1|FILE2|...]

${BOLD}DESCRIPTION${RST}
	Generate patchset to send email.

${BOLD}ARGUMENT${RST}
	${BOLD}Generate patchset arguments:${RST}
	--subject-prefix [STR]   specify Subject prefix
	--from [COMMIT]          specify downer/older commit, see git log --oneline
	--to [COMMIT]            specify upper/newer commit, see git log --oneline
	--no-cover-letter        no cover letter
	--pure-diff              Output pure 'diff' format.
	-o, --output [DIR]       specify output directory, default: ${output_dir}

	${BOLD}Patch operate arguments:${RST}
	-p, --patch [FILE]       specify a patch file

	${BOLD}Common arguments:${RST}
	-n, --dry-run            dump command instead execute
	-h, --help               show this help information
	-v, --verbose            show detail during running
	-V, --version            show version

${BOLD}DEVELOPE GIT PATCHSET${RST}
	$ git rebase ${BOLD}<parent commit of modified commit>${RST} --interactive
	${GRAY}# Then, change the '${RST}${GREEN}pick${RST}${GRAY}' in front of the commit that needs to be
	# changed to '${RST}${GREEN}edit${RST}${GRAY}', then, save and exit;${RST}
	${GRAY}# Then, modify the code.${RST}
	$ git add ${BOLD}<files>${RST} ${GRAY}[--all]${RST}
	$ git commit --amend
	$ git rebase --continue

${BOLD}BARE GIT EXAMPLES${RST}
	${GRAY}# Generate single one pretty patch${RST}
	$ git format-patch ${UL}-1${RST} --pretty=fuller HEAD
	${GRAY}# Generate single one patch with e-mail${RST}
	$ git format-patch ${UL}-1${RST} HEAD --to=${UL}rtoax@foxmail.com${RST} \\
				 --cc=${UL}linux-kernel@vger.kernel.org${RST}
	${GRAY}# Generate 2 patches patchset with cover letter${RST}
	$ git format-patch ${UL}-2${RST} -s --cover-letter --thread \\
			--subject-prefix=\"${UL}PATCH v3${RST}\"
	${GRAY}# Then, send-email, see below.${RST}

${BOLD}PATCHSET EXAMPLES${RST}
	${GRAY}# Submit a patchset:${RST}
	$ patchset --from ${UL}[commit1]${RST} --to ${UL}[commit2]${RST} --subject-prefix=\"${UL}PATCH bpf-next v3${RST}\"
	${GRAY}# Then, modify 0000-cover-letter.patch${RST}
	${GRAY}# check patches (scripts/checkpatch.pl if linux)${RST}
	$ git send-email ${dry_run:+--dry-run} ${GRAY}[--to|--cc|--to-cmd=] --confirm=[always|never|cc|compose|auto]${RST} ${output_dir}/*.patch

${BOLD}GIT EXAMPLES${RST}
	${GRAY}# Check patchset for single file between two commits/tags:${RST}
	$ git log v5.15.131^..v5.15.191 -p Makefile
	${GRAY}# Compare two branches${RST}
	$ git diff ${UL}BRANCH1${RST} ${UL}BRANCH2${RST} ${GRAY}-- FILE${RST}
	$ git log ${UL}BRANCH1${RST}..${UL}BRANCH2${RST} ${GRAY}--oneline${RST}

${BOLD}SEE ALSO${RST}
	git(1), git‐format‐patch(1), git‐send‐email(1)

${BOLD}AUTHOR${RST}
	Rong Tao

${BOLD}LINKS${RST}
	1. https://kernelnewbies.org/FirstKernelPatch
	2. https://www.kernel.org/doc/html/latest/process/submitting-patches.html
" | more
	exit ${1-0}
}

warning() {
	echo -e >&2 "${RED}WARNING: ${@}${RST}"
}

__patchset_getopt__()
{
	local TEMP=$(getopt \
		--options o:p:nvhV \
		--long subject-prefix: \
		--long from: \
		--long to: \
		--long no-cover-letter \
		--long pure-diff \
		--long output: \
		--long patch: \
		--long dry-run \
		--long verbose \
		--long version \
		--long help \
		-n patchset -- "$@")

	test $? != 0 && __patchset_usage__ 1

	eval set -- "$TEMP"

	while true; do
		case $1 in
		--subject-prefix)
			shift
			subject_prefix="$1"
			if ! [[ " ${subject_prefix} " =~ " PATCH " ]]; then
				error "Not found 'PATCH' in subject prefix, example: 'PATCH bpf-next'"
			fi
			shift
			;;
		--from)
			shift
			downer_commit="$1"
			shift
			;;
		--to)
			shift
			if [[ -z ${downer_commit} ]]; then
				error "specify --from first"
			fi
			upper_commit="$1"
			shift
			;;
		--no-cover-letter)
			shift
			no_cover_letter=YES
			;;
		--pure-diff)
			shift
			pure_diff=YES
			;;
		-o|--output)
			shift
			output_dir=$1
			shift
			;;
		-p|--patch)
			shift
			if [[ ! -f $1 ]]; then
				error "File $1 is not exist."
			fi
			patch_files+=( $1 )
			shift
			;;
		-n|--dry-run)
			shift
			dry_run=YES
			;;
		-h|--help)
			shift
			__patchset_usage__
			;;
		-v|--verbose)
			shift
			export PS4='+${BASH_SOURCE}:${LINENO}:${FUNCNAME[0]}: '
			set -x
			;;
		-V|--version)
			shift
			echo "${VERSION}"
			exit 0
			;;
		--)
			shift
			abbrev_commits+=( $@ )
			break
			;;
		esac
	done
}

my_eval()
{
	if [[ $dry_run == YES ]]; then
		echo "$@"
	else
		eval "$@"
	fi
}

# $1 - one file
file2commits() {
	git log --follow --abbrev=12 --pretty=format:%h $1 2>/dev/null
}

# Submit multi-patches at one time
# ref: https://kernelnewbies.org/FirstKernelPatch
generate_patchset()
{
	local args

	if [[ -z ${downer_commit} ]] || [[ -z ${upper_commit} ]]; then
		__patchset_usage__ | cat
		error "Must specify --from and --to at the same time"
	fi

	if [[ -e ${output_dir} ]] && [[ ! -d ${output_dir} ]]; then
		error "${output_dir} is already exist and is not directory"
	fi

	args+=( --numbered )
	args+=( --thread=shallow )

	if [[ ${no_cover_letter} ]]; then
		args+=( --no-cover-letter )
	else
		args+=( --cover-letter )
	fi

	if [[ ${pure_diff} ]]; then
		if [[ -z ${no_cover_letter} ]]; then
			error "Pure diff must without cover letter"
		fi
		args+=( --pretty=format:'' --no-prefix --no-stat )
		# Git 2.11+, disable seperator '--' in the end of patch.
		args+=( --no-signature )
	fi

	my_eval git format-patch \
		${args[@]} \
		${subject_prefix:+--subject-prefix="'${subject_prefix}'"} \
		${downer_commit}^..${upper_commit} \
		-o ${output_dir}
}

patch_operate()
{
	local patch subject
	for patch in ${patch_files[@]}; do
		subject="$(grep -A1 ^Subject: ${patch} | \
			   tr -d '\n' | \
			   sed 's/^Subject: //g' | \
			   sed 's#\[PATCH [0-9]\+/[0-9]\+\] ##')"
		echo "${subject}"
	done
}

__patchset_getopt__ "$@"

# If the -- parameter is specified, a summary of the
# commit is displayed.
if [[ " ${@} " =~ " -- " ]]; then
	git_cmd="git log"
	if [[ ${#abbrev_commits[@]} -ge 1 ]]; then
		git_cmd="git show --no-patch"
		for ((i = 0; i < ${#abbrev_commits[@]}; i++)); do
			commit=${abbrev_commits[$i]}
			if [[ -f ${commit} ]]; then
				unset abbrev_commits[$i]
				abbrev_commits+=( $(file2commits ${commit}) )
			fi
		done
	fi
	# NOTE: linux kernel 'Fixes:' don't need 'commit' prefix.
	my_eval ${git_cmd} --abbrev=12 --pretty=format:\''commit %h ("%s")'\' ${abbrev_commits[@]}
fi

if [[ ${downer_commit} ]] || [[ ${upper_commit} ]]; then
	generate_patchset
fi

if [[ ${patch_files} ]]; then
	patch_operate
fi