git-commit-vandalism/git-bisect.sh
Christian Couder d3e54c8829 git-bisect: make "start", "good" and "skip" succeed or fail atomically
Before this patch, when "git bisect start", "git bisect good" or
"git bisect skip" were called with many revisions, they could fail
after having already marked some revisions as "good", "bad" or
"skip".

This could be especilally bad for "git bisect start" because as
the file ".git/BISECT_NAMES" would not have been written, there
would have been no attempt to clear the marked revisions on a
"git bisect reset". That's because if there is no
".git/BISECT_NAMES" file, nothing is done to clean things up, as
the bisect session is not supposed to have started.

While at it, let's also create the ".git/BISECT_START" file, only
after ".git/BISECT_NAMES" as been created.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-16 00:11:37 -07:00

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#!/bin/sh
USAGE='[start|bad|good|skip|next|reset|visualize|replay|log|run]'
LONG_USAGE='git bisect start [<bad> [<good>...]] [--] [<pathspec>...]
reset bisect state and start bisection.
git bisect bad [<rev>]
mark <rev> a known-bad revision.
git bisect good [<rev>...]
mark <rev>... known-good revisions.
git bisect skip [<rev>...]
mark <rev>... untestable revisions.
git bisect next
find next bisection to test and check it out.
git bisect reset [<branch>]
finish bisection search and go back to branch.
git bisect visualize
show bisect status in gitk.
git bisect replay <logfile>
replay bisection log.
git bisect log
show bisect log.
git bisect run <cmd>...
use <cmd>... to automatically bisect.'
OPTIONS_SPEC=
. git-sh-setup
require_work_tree
_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
sq() {
@@PERL@@ -e '
for (@ARGV) {
s/'\''/'\'\\\\\'\''/g;
print " '\''$_'\''";
}
print "\n";
' "$@"
}
bisect_autostart() {
test -f "$GIT_DIR/BISECT_NAMES" || {
echo >&2 'You need to start by "git bisect start"'
if test -t 0
then
echo >&2 -n 'Do you want me to do it for you [Y/n]? '
read yesno
case "$yesno" in
[Nn]*)
exit ;;
esac
bisect_start
else
exit 1
fi
}
}
bisect_start() {
#
# Verify HEAD. If we were bisecting before this, reset to the
# top-of-line master first!
#
head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) ||
head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
die "Bad HEAD - I need a HEAD"
start_head=''
case "$head" in
refs/heads/bisect)
if [ -s "$GIT_DIR/BISECT_START" ]; then
branch=`cat "$GIT_DIR/BISECT_START"`
else
branch=master
fi
git checkout $branch || exit
;;
refs/heads/*|$_x40)
# This error message should only be triggered by cogito usage,
# and cogito users should understand it relates to cg-seek.
[ -s "$GIT_DIR/head-name" ] && die "won't bisect on seeked tree"
start_head="${head#refs/heads/}"
;;
*)
die "Bad HEAD - strange symbolic ref"
;;
esac
#
# Get rid of any old bisect state
#
bisect_clean_state
#
# Check for one bad and then some good revisions.
#
has_double_dash=0
for arg; do
case "$arg" in --) has_double_dash=1; break ;; esac
done
orig_args=$(sq "$@")
bad_seen=0
eval=''
while [ $# -gt 0 ]; do
arg="$1"
case "$arg" in
--)
shift
break
;;
*)
rev=$(git rev-parse --verify "$arg^{commit}" 2>/dev/null) || {
test $has_double_dash -eq 1 &&
die "'$arg' does not appear to be a valid revision"
break
}
case $bad_seen in
0) state='bad' ; bad_seen=1 ;;
*) state='good' ;;
esac
eval="$eval bisect_write '$state' '$rev' 'nolog'; "
shift
;;
esac
done
sq "$@" >"$GIT_DIR/BISECT_NAMES"
test -n "$start_head" && echo "$start_head" >"$GIT_DIR/BISECT_START"
eval "$eval"
echo "git-bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG"
bisect_auto_next
}
bisect_write() {
state="$1"
rev="$2"
nolog="$3"
case "$state" in
bad) tag="$state" ;;
good|skip) tag="$state"-"$rev" ;;
*) die "Bad bisect_write argument: $state" ;;
esac
git update-ref "refs/bisect/$tag" "$rev"
echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
test -z "$nolog" && echo "git-bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
}
bisect_state() {
bisect_autostart
state=$1
case "$#,$state" in
0,*)
die "Please call 'bisect_state' with at least one argument." ;;
1,bad|1,good|1,skip)
rev=$(git rev-parse --verify HEAD) ||
die "Bad rev input: HEAD"
bisect_write "$state" "$rev" ;;
2,bad|*,good|*,skip)
shift
eval=''
for rev in "$@"
do
sha=$(git rev-parse --verify "$rev^{commit}") ||
die "Bad rev input: $rev"
eval="$eval bisect_write '$state' '$sha'; "
done
eval "$eval" ;;
*,bad)
die "'git bisect bad' can take only one argument." ;;
*)
usage ;;
esac
bisect_auto_next
}
bisect_next_check() {
missing_good= missing_bad=
git show-ref -q --verify refs/bisect/bad || missing_bad=t
test -n "$(git for-each-ref "refs/bisect/good-*")" || missing_good=t
case "$missing_good,$missing_bad,$1" in
,,*)
: have both good and bad - ok
;;
*,)
# do not have both but not asked to fail - just report.
false
;;
t,,good)
# have bad but not good. we could bisect although
# this is less optimum.
echo >&2 'Warning: bisecting only with a bad commit.'
if test -t 0
then
printf >&2 'Are you sure [Y/n]? '
case "$(read yesno)" in [Nn]*) exit 1 ;; esac
fi
: bisect without good...
;;
*)
THEN=''
test -f "$GIT_DIR/BISECT_NAMES" || {
echo >&2 'You need to start by "git bisect start".'
THEN='then '
}
echo >&2 'You '$THEN'need to give me at least one good' \
'and one bad revisions.'
echo >&2 '(You can use "git bisect bad" and' \
'"git bisect good" for that.)'
exit 1 ;;
esac
}
bisect_auto_next() {
bisect_next_check && bisect_next || :
}
filter_skipped() {
_eval="$1"
_skip="$2"
if [ -z "$_skip" ]; then
eval $_eval
return
fi
# Let's parse the output of:
# "git rev-list --bisect-vars --bisect-all ..."
eval $_eval | while read hash line
do
case "$VARS,$FOUND,$TRIED,$hash" in
# We display some vars.
1,*,*,*) echo "$hash $line" ;;
# Split line.
,*,*,---*) ;;
# We had nothing to search.
,,,bisect_rev*)
echo "bisect_rev="
VARS=1
;;
# We did not find a good bisect rev.
# This should happen only if the "bad"
# commit is also a "skip" commit.
,,*,bisect_rev*)
echo "bisect_rev=$TRIED"
VARS=1
;;
# We are searching.
,,*,*)
TRIED="${TRIED:+$TRIED|}$hash"
case "$_skip" in
*$hash*) ;;
*)
echo "bisect_rev=$hash"
echo "bisect_tried=\"$TRIED\""
FOUND=1
;;
esac
;;
# We have already found a rev to be tested.
,1,*,bisect_rev*) VARS=1 ;;
,1,*,*) ;;
# ???
*) die "filter_skipped error " \
"VARS: '$VARS' " \
"FOUND: '$FOUND' " \
"TRIED: '$TRIED' " \
"hash: '$hash' " \
"line: '$line'"
;;
esac
done
}
exit_if_skipped_commits () {
_tried=$1
if expr "$_tried" : ".*[|].*" > /dev/null ; then
echo "There are only 'skip'ped commit left to test."
echo "The first bad commit could be any of:"
echo "$_tried" | tr '[|]' '[\012]'
echo "We cannot bisect more!"
exit 2
fi
}
bisect_next() {
case "$#" in 0) ;; *) usage ;; esac
bisect_autostart
bisect_next_check good
skip=$(git for-each-ref --format='%(objectname)' \
"refs/bisect/skip-*" | tr '[\012]' ' ') || exit
BISECT_OPT=''
test -n "$skip" && BISECT_OPT='--bisect-all'
bad=$(git rev-parse --verify refs/bisect/bad) &&
good=$(git for-each-ref --format='^%(objectname)' \
"refs/bisect/good-*" | tr '[\012]' ' ') &&
eval="git rev-list --bisect-vars $BISECT_OPT $good $bad --" &&
eval="$eval $(cat "$GIT_DIR/BISECT_NAMES")" &&
eval=$(filter_skipped "$eval" "$skip") &&
eval "$eval" || exit
if [ -z "$bisect_rev" ]; then
echo "$bad was both good and bad"
exit 1
fi
if [ "$bisect_rev" = "$bad" ]; then
exit_if_skipped_commits "$bisect_tried"
echo "$bisect_rev is first bad commit"
git diff-tree --pretty $bisect_rev
exit 0
fi
# We should exit here only if the "bad"
# commit is also a "skip" commit (see above).
exit_if_skipped_commits "$bisect_rev"
echo "Bisecting: $bisect_nr revisions left to test after this"
git branch -f new-bisect "$bisect_rev"
git checkout -q new-bisect || exit
git branch -M new-bisect bisect
git show-branch "$bisect_rev"
}
bisect_visualize() {
bisect_next_check fail
if test $# = 0
then
case "${DISPLAY+set}" in
'') set git log ;;
set) set gitk ;;
esac
else
case "$1" in
git*|tig) ;;
-*) set git log "$@" ;;
*) set git "$@" ;;
esac
fi
not=$(git for-each-ref --format='%(refname)' "refs/bisect/good-*")
eval '"$@"' refs/bisect/bad --not $not -- $(cat "$GIT_DIR/BISECT_NAMES")
}
bisect_reset() {
test -f "$GIT_DIR/BISECT_NAMES" || {
echo "We are not bisecting."
return
}
case "$#" in
0) if [ -s "$GIT_DIR/BISECT_START" ]; then
branch=`cat "$GIT_DIR/BISECT_START"`
else
branch=master
fi ;;
1) git show-ref --verify --quiet -- "refs/heads/$1" ||
die "$1 does not seem to be a valid branch"
branch="$1" ;;
*)
usage ;;
esac
if git checkout "$branch"; then
# Cleanup head-name if it got left by an old version of git-bisect
rm -f "$GIT_DIR/head-name"
rm -f "$GIT_DIR/BISECT_START"
bisect_clean_state
fi
}
bisect_clean_state() {
# There may be some refs packed during bisection.
git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* refs/heads/bisect |
while read ref hash
do
git update-ref -d $ref $hash
done
rm -f "$GIT_DIR/BISECT_LOG"
rm -f "$GIT_DIR/BISECT_NAMES"
rm -f "$GIT_DIR/BISECT_RUN"
}
bisect_replay () {
test -r "$1" || die "cannot read $1 for replaying"
bisect_reset
while read bisect command rev
do
test "$bisect" = "git-bisect" || continue
case "$command" in
start)
cmd="bisect_start $rev"
eval "$cmd" ;;
good|bad|skip)
bisect_write "$command" "$rev" ;;
*)
die "?? what are you talking about?" ;;
esac
done <"$1"
bisect_auto_next
}
bisect_run () {
bisect_next_check fail
while true
do
echo "running $@"
"$@"
res=$?
# Check for really bad run error.
if [ $res -lt 0 -o $res -ge 128 ]; then
echo >&2 "bisect run failed:"
echo >&2 "exit code $res from '$@' is < 0 or >= 128"
exit $res
fi
# Find current state depending on run success or failure.
# A special exit code of 125 means cannot test.
if [ $res -eq 125 ]; then
state='skip'
elif [ $res -gt 0 ]; then
state='bad'
else
state='good'
fi
# We have to use a subshell because "bisect_state" can exit.
( bisect_state $state > "$GIT_DIR/BISECT_RUN" )
res=$?
cat "$GIT_DIR/BISECT_RUN"
if grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
> /dev/null; then
echo >&2 "bisect run cannot continue any more"
exit $res
fi
if [ $res -ne 0 ]; then
echo >&2 "bisect run failed:"
echo >&2 "'bisect_state $state' exited with error code $res"
exit $res
fi
if grep "is first bad commit" "$GIT_DIR/BISECT_RUN" > /dev/null; then
echo "bisect run success"
exit 0;
fi
done
}
case "$#" in
0)
usage ;;
*)
cmd="$1"
shift
case "$cmd" in
start)
bisect_start "$@" ;;
bad|good|skip)
bisect_state "$cmd" "$@" ;;
next)
# Not sure we want "next" at the UI level anymore.
bisect_next "$@" ;;
visualize|view)
bisect_visualize "$@" ;;
reset)
bisect_reset "$@" ;;
replay)
bisect_replay "$@" ;;
log)
cat "$GIT_DIR/BISECT_LOG" ;;
run)
bisect_run "$@" ;;
*)
usage ;;
esac
esac