blob: 0f4382bec4c22d2314ff910af30fc86c3032bdc7 [file] [log] [blame]
#!/bin/bash
#
# Compares multiple branches against a reference and shows which ones contain
# each commit, and the level of backports since the origin or its own ancestors.
#
# Copyright (c) 2016 Willy Tarreau <w@1wt.eu>
#
# The purpose is to make it easy to visualize what backports might be missing
# in a maintenance branch, and to easily spot the ones that are needed and the
# ones that are not. It solely relies on the "cherry-picked from" tags in the
# commit messages to find what commit is available where, and can even find a
# reference commit's ancestor in another branch's commit ancestors as well to
# detect that the patch is present. When done with the proper references and
# a correct ordering of the branches, it can be used to quickly apply a set of
# fixes to a branch since it dumps suggested commands at the end. When doing
# so it is a good idea to use "HEAD" as the last branch to avoid doing mistakes.
#
# Examples :
# - find what's in master and not in current branch :
# show-backports -q -m -r master HEAD
# - find what's in 1.6/master and in hapee-maint-1.5r2 but not in current branch :
# show-backports -q -m -r 1.6/master hapee-maint-1.5r2 HEAD | grep ' [a-f0-9]\{8\}[-+][0-9] '
# - check that no recent fix from master is missing in any maintenance branch :
# show-backports -r master hapee-maint-1.5r2 aloha-7.5 hapee-maint-1.5r1 aloha-7.0
# - see what was recently merged into 1.6 and has no equivalent in local master :
# show-backports -q -m -r 1.6/master -b "1.6/master@{1 week ago}" master
# - check what extra backports are present in hapee-r2 compared to hapee-r1 :
# show-backports -q -m -r hapee-r2 hapee-r1
USAGE="Usage: ${0##*/} [-q] [-m] [-r reference] [-l logexpr] [-s subject] [-b base] branch [...]"
BRANCHES=( )
REF=master
BASE=
QUIET=
LOGEXPR=
SUBJECT=
MISSING=
die() {
[ "$#" -eq 0 ] || echo "$*" >&2
exit 1
}
err() {
echo "$*" >&2
}
quit() {
[ "$#" -eq 0 ] || echo "$*"
exit 0
}
short() {
# git rev-parse --short $1
echo "${1::8}"
}
dump_commit_matrix() {
title=":$REF:"
for branch in "${BRANCHES[@]}"; do
#echo -n " $branch"
title="$title :${branch}:"
done
title="$title |"
count=0
# now look up commits
while read ref subject; do
if [ -n "$MISSING" -a "${subject:0:9}" = "[RELEASE]" ]; then
continue
fi
upstream="none"
missing=0
line="$(short $ref)"
for branch in "${BRANCHES[@]}"; do
set -- $(grep -m 1 $ref "$WORK/${branch//\//_}")
newhash=$1 ; shift
# count the number of cherry-picks after this one. Since we shift,
# the result is in "$#"
while [ -n "$1" -a "$1" != "$ref" ]; do
shift
done
if [ -n "$newhash" ]; then
line="${line} $(short $newhash)-$#"
else
# before giving up we can check if our current commit was
# itself cherry-picked and check this again. In order not
# to have to do it all the time, we can cache the result
# for the current line. If a match is found we report it
# with the '+' delimiter instead of '-'.
if [ "$upstream" = "none" ]; then
upstream=( $(git log -1 --pretty --format=%B "$ref" | \
sed -n 's/^commit \([^)]*\) upstream\.$/\1/p;s/^(cherry picked from commit \([^)]*\))/\1/p') )
fi
newhash=""
for h in ${upstream[@]}; do
set -- $(grep -m 1 $h "$WORK/${branch//\//_}")
newhash=$1 ; shift
while [ -n "$1" -a "$1" != "$h" ]; do
shift
done
if [ -n "$newhash" ]; then
line="${line} $(short $newhash)+$#"
break
fi
done
if [ -z "$newhash" ]; then
line="${line} -"
missing=1
fi
fi
done
line="${line} |"
if [ -z "$MISSING" -o $missing -gt 0 ]; then
[ $((count++)) -gt 0 ] || echo $title
[ "$QUIET" != "" -o $count -lt 20 ] || count=0
echo "$line"
fi
done < "$WORK/${REF//\//_}"
}
while [ -n "$1" -a -z "${1##-*}" ]; do
case "$1" in
-b) BASE="$2" ; shift 2 ;;
-r) REF="$2" ; shift 2 ;;
-l) LOGEXPR="$2" ; shift 2 ;;
-s) SUBJECT="$2" ; shift 2 ;;
-q) QUIET=1 ; shift ;;
-m) MISSING=1 ; shift ;;
-h|--help) quit "$USAGE" ;;
*) die "$USAGE" ;;
esac
done
BRANCHES=( "$@" )
if [ ${#BRANCHES[@]} = 0 ]; then
die "$USAGE"
fi
for branch in "$REF" "${BRANCHES[@]}"; do
if ! git rev-parse --verify -q "$branch" >/dev/null; then
die "Failed to check git branch $branch."
fi
done
if [ -z "$BASE" ]; then
err "Warning! No base specified, looking for common ancestor."
BASE=$(git merge-base --all "$REF" "${BRANCHES[@]}")
if [ -z "$BASE" ]; then
die "Couldn't find a common ancestor between these branches"
fi
fi
# we want to go to the git root dir
DIR="$PWD"
cd $(git rev-parse --show-toplevel)
mkdir -p .git/.show-backports #|| die "Can't create .git/.show-backports"
WORK=.git/.show-backports
rm -f "$WORK/${REF//\//_}"
git log --reverse ${LOGEXPR:+--grep $LOGEXPR} --pretty="%H %s" "$BASE".."$REF" | grep "${SUBJECT}" > "$WORK/${branch//\//_}" > "$WORK/${REF//\//_}"
# for each branch, enumerate all commits and their ancestry
for branch in "${BRANCHES[@]}"; do
rm -f "$WORK/${branch//\//_}"
git log --reverse --pretty="%H %s" "$BASE".."$branch" | grep "${SUBJECT}" | while read h subject; do
echo "$h" $(git log -1 --pretty --format=%B "$h" | \
sed -n 's/^commit \([^)]*\) upstream\.$/\1/p;s/^(cherry picked from commit \([^)]*\))/\1/p')
done > "$WORK/${branch//\//_}"
done
count=0
dump_commit_matrix | column -t | \
(
left_commits=( )
right_commits=( )
while read line; do
# append the subject at the end of the line
set -- $line
echo -n "$line "
if [ "${line::1}" = ":" ]; then
echo "---- Subject ----"
else
# doing it this way prevents git from abusing the terminal
echo $(git log -1 --pretty="%s" "$1")
left_commits[${#left_commits[@]}]="$1"
comm=""
while [ -n "$1" -a "$1" != "-" -a "$1" != "|" ]; do
comm="${1%-*}"
shift
done
right_commits[${#right_commits[@]}]="$comm"
fi
done
if [ -n "$MISSING" -a ${#left_commits[@]} -eq 0 ]; then
echo "No missing commit to apply."
elif [ -n "$MISSING" ]; then
echo
echo "In order to apply all leftmost commits to current branch :"
echo " git cherry-pick -x ${left_commits[@]}"
echo
echo "In order to apply all rightmost commits to current branch :"
echo " git cherry-pick -x ${right_commits[@]}"
fi
)