git/git-bisect.sh
Christian Couder 6a54d976f6 bisect: remove "checkout_done" variable used when checking merge bases
Using return values from the following functions:

- check_merge_bases
- check_good_are_ancestors_of_bad

seems simpler.

While at it, let's add some comments to better document the above
functions.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-05 22:31:43 -07:00

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#!/bin/sh
USAGE='[help|start|bad|good|skip|next|reset|visualize|replay|log|run]'
LONG_USAGE='git bisect help
print this long help message.
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.
Please use "git help bisect" to get the full man page.'
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 -s "$GIT_DIR/BISECT_START" || {
echo >&2 'You need to start by "git bisect start"'
if test -t 0
then
echo >&2 -n 'Do you want me to do it for you [Y/n]? '
read yesno
case "$yesno" in
[Nn]*)
exit ;;
esac
bisect_start
else
exit 1
fi
}
}
bisect_start() {
#
# Verify HEAD.
#
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"
#
# Check if we are bisecting.
#
start_head=''
if test -s "$GIT_DIR/BISECT_START"
then
# Reset to the rev from where we started.
start_head=$(cat "$GIT_DIR/BISECT_START")
git checkout "$start_head" || exit
else
# Get rev from where we start.
case "$head" in
refs/heads/*|$_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
fi
#
# Get rid of any old bisect state.
#
bisect_clean_state || exit
#
# 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=$(git rev-parse -q --verify "$arg^{commit}") || {
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
#
# Change state.
# In case of mistaken revs or checkout error, or signals received,
# "bisect_auto_next" below may exit or misbehave.
# We have to trap this to be able to clean up using
# "bisect_clean_state".
#
trap 'bisect_clean_state' 0
trap 'exit 255' 1 2 3 15
#
# Write new start state.
#
echo "$start_head" >"$GIT_DIR/BISECT_START" &&
sq "$@" >"$GIT_DIR/BISECT_NAMES" &&
eval "$eval" &&
echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
#
# Check if we can proceed to the next bisect state.
#
bisect_auto_next
trap '-' 0
}
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" || exit
echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
test -n "$nolog" || echo "git bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
}
is_expected_rev() {
test -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
test "$1" = $(cat "$GIT_DIR/BISECT_EXPECTED_REV")
}
mark_expected_rev() {
echo "$1" > "$GIT_DIR/BISECT_EXPECTED_REV"
}
check_expected_revs() {
for _rev in "$@"; do
if ! is_expected_rev "$_rev"; then
rm -f "$GIT_DIR/BISECT_ANCESTORS_OK"
rm -f "$GIT_DIR/BISECT_EXPECTED_REV"
return
fi
done
}
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"
check_expected_revs "$rev" ;;
2,bad|*,good|*,skip)
shift
eval=''
for rev in "$@"
do
sha=$(git rev-parse --verify "$rev^{commit}") ||
die "Bad rev input: $rev"
eval="$eval bisect_write '$state' '$sha'; "
done
eval "$eval"
check_expected_revs "$@" ;;
*,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,$1" in
,,*)
: have both good and bad - ok
;;
*,)
# do not have both but not asked to fail - just report.
false
;;
t,,good)
# have bad but not good. we could bisect although
# this is less optimum.
echo >&2 'Warning: bisecting only with a bad commit.'
if test -t 0
then
printf >&2 'Are you sure [Y/n]? '
read yesno
case "$yesno" in [Nn]*) exit 1 ;; esac
fi
: bisect without good...
;;
*)
THEN=''
test -s "$GIT_DIR/BISECT_START" || {
echo >&2 'You need to start by "git bisect start".'
THEN='then '
}
echo >&2 'You '$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_checkout() {
_rev="$1"
_msg="$2"
echo "Bisecting: $_msg"
mark_expected_rev "$_rev"
git checkout -q "$_rev" || exit
git show-branch "$_rev"
}
is_among() {
_rev="$1"
_list="$2"
case "$_list" in *$_rev*) return 0 ;; esac
return 1
}
handle_bad_merge_base() {
_badmb="$1"
_good="$2"
if is_expected_rev "$_badmb"; then
cat >&2 <<EOF
The merge base $_badmb is bad.
This means the bug has been fixed between $_badmb and [$_good].
EOF
exit 3
else
cat >&2 <<EOF
Some good revs are not ancestor of the bad rev.
git bisect cannot work properly in this case.
Maybe you mistake good and bad revs?
EOF
exit 1
fi
}
handle_skipped_merge_base() {
_mb="$1"
_bad="$2"
_good="$3"
cat >&2 <<EOF
Warning: the merge base between $_bad and [$_good] must be skipped.
So we cannot be sure the first bad commit is between $_mb and $_bad.
We continue anyway.
EOF
}
#
# "check_merge_bases" checks that merge bases are not "bad".
#
# - If one is "good", that's good, we have nothing to do.
# - If one is "bad", it means the user assumed something wrong
# and we must exit.
# - If one is "skipped", we can't know but we should warn.
# - If we don't know, we should check it out and ask the user to test.
#
# In the last case we will return 1, and otherwise 0.
#
check_merge_bases() {
_bad="$1"
_good="$2"
_skip="$3"
for _mb in $(git merge-base --all $_bad $_good)
do
if is_among "$_mb" "$_good"; then
continue
elif test "$_mb" = "$_bad"; then
handle_bad_merge_base "$_bad" "$_good"
elif is_among "$_mb" "$_skip"; then
handle_skipped_merge_base "$_mb" "$_bad" "$_good"
else
bisect_checkout "$_mb" "a merge base must be tested"
return 1
fi
done
return 0
}
#
# "check_good_are_ancestors_of_bad" checks that all "good" revs are
# ancestor of the "bad" rev.
#
# If that's not the case, we need to check the merge bases.
# If a merge base must be tested by the user we return 1 and
# otherwise 0.
#
check_good_are_ancestors_of_bad() {
test -f "$GIT_DIR/BISECT_ANCESTORS_OK" &&
return
_bad="$1"
_good=$(echo $2 | sed -e 's/\^//g')
_skip="$3"
# Bisecting with no good rev is ok
test -z "$_good" && return
_side=$(git rev-list $_good ^$_bad)
if test -n "$_side"; then
# Return if a checkout was done
check_merge_bases "$_bad" "$_good" "$_skip" || return
fi
: > "$GIT_DIR/BISECT_ANCESTORS_OK"
return 0
}
bisect_next() {
case "$#" in 0) ;; *) usage ;; esac
bisect_autostart
bisect_next_check good
# Get bad, good and skipped revs
bad=$(git rev-parse --verify refs/bisect/bad) &&
good=$(git for-each-ref --format='^%(objectname)' \
"refs/bisect/good-*" | tr '\012' ' ') &&
skip=$(git for-each-ref --format='%(objectname)' \
"refs/bisect/skip-*" | tr '\012' ' ') &&
# Maybe some merge bases must be tested first
check_good_are_ancestors_of_bad "$bad" "$good" "$skip"
# Return now if a checkout has already been done
test "$?" -eq "1" && return
# Get bisection information
BISECT_OPT=''
test -n "$skip" && BISECT_OPT='--bisect-all'
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"
bisect_checkout "$bisect_rev" "$bisect_nr revisions left to test after this"
}
bisect_visualize() {
bisect_next_check fail
if test $# = 0
then
case "${DISPLAY+set}${MSYSTEM+set}${SECURITYSESSIONID+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 -s "$GIT_DIR/BISECT_START" || {
echo "We are not bisecting."
return
}
case "$#" in
0) branch=$(cat "$GIT_DIR/BISECT_START") ;;
1) git show-ref --verify --quiet -- "refs/heads/$1" ||
die "$1 does not seem to be a valid branch"
branch="$1" ;;
*)
usage ;;
esac
git checkout "$branch" && bisect_clean_state
}
bisect_clean_state() {
# There may be some refs packed during bisection.
git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* |
while read ref hash
do
git update-ref -d $ref $hash || exit
done
rm -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
rm -f "$GIT_DIR/BISECT_ANCESTORS_OK" &&
rm -f "$GIT_DIR/BISECT_LOG" &&
rm -f "$GIT_DIR/BISECT_NAMES" &&
rm -f "$GIT_DIR/BISECT_RUN" &&
# 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_replay () {
test -r "$1" || die "cannot read $1 for replaying"
bisect_reset
while read git bisect command rev
do
test "$git $bisect" = "git bisect" -o "$git" = "git-bisect" || continue
if test "$git" = "git-bisect"; then
rev="$command"
command="$bisect"
fi
case "$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
help)
git bisect -h ;;
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