make prefix_path() never return NULL
[git] / git-bisect.sh
1 #!/bin/sh
2
3 USAGE='[help|start|bad|good|skip|next|reset|visualize|replay|log|run]'
4 LONG_USAGE='git bisect help
5         print this long help message.
6 git bisect start [<bad> [<good>...]] [--] [<pathspec>...]
7         reset bisect state and start bisection.
8 git bisect bad [<rev>]
9         mark <rev> a known-bad revision.
10 git bisect good [<rev>...]
11         mark <rev>... known-good revisions.
12 git bisect skip [<rev>...]
13         mark <rev>... untestable revisions.
14 git bisect next
15         find next bisection to test and check it out.
16 git bisect reset [<branch>]
17         finish bisection search and go back to branch.
18 git bisect visualize
19         show bisect status in gitk.
20 git bisect replay <logfile>
21         replay bisection log.
22 git bisect log
23         show bisect log.
24 git bisect run <cmd>...
25         use <cmd>... to automatically bisect.
26
27 Please use "git help bisect" to get the full man page.'
28
29 OPTIONS_SPEC=
30 . git-sh-setup
31 require_work_tree
32
33 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
34 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
35
36 sq() {
37         @@PERL@@ -e '
38                 for (@ARGV) {
39                         s/'\''/'\'\\\\\'\''/g;
40                         print " '\''$_'\''";
41                 }
42                 print "\n";
43         ' "$@"
44 }
45
46 bisect_autostart() {
47         test -s "$GIT_DIR/BISECT_START" || {
48                 echo >&2 'You need to start by "git bisect start"'
49                 if test -t 0
50                 then
51                         echo >&2 -n 'Do you want me to do it for you [Y/n]? '
52                         read yesno
53                         case "$yesno" in
54                         [Nn]*)
55                                 exit ;;
56                         esac
57                         bisect_start
58                 else
59                         exit 1
60                 fi
61         }
62 }
63
64 bisect_start() {
65         #
66         # Verify HEAD.
67         #
68         head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) ||
69         head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
70         die "Bad HEAD - I need a HEAD"
71
72         #
73         # Check if we are bisecting.
74         #
75         start_head=''
76         if test -s "$GIT_DIR/BISECT_START"
77         then
78                 # Reset to the rev from where we started.
79                 start_head=$(cat "$GIT_DIR/BISECT_START")
80                 git checkout "$start_head" || exit
81         else
82                 # Get rev from where we start.
83                 case "$head" in
84                 refs/heads/*|$_x40)
85                         # This error message should only be triggered by
86                         # cogito usage, and cogito users should understand
87                         # it relates to cg-seek.
88                         [ -s "$GIT_DIR/head-name" ] &&
89                                 die "won't bisect on seeked tree"
90                         start_head="${head#refs/heads/}"
91                         ;;
92                 *)
93                         die "Bad HEAD - strange symbolic ref"
94                         ;;
95                 esac
96         fi
97
98         #
99         # Get rid of any old bisect state.
100         #
101         bisect_clean_state || exit
102
103         #
104         # Check for one bad and then some good revisions.
105         #
106         has_double_dash=0
107         for arg; do
108             case "$arg" in --) has_double_dash=1; break ;; esac
109         done
110         orig_args=$(sq "$@")
111         bad_seen=0
112         eval=''
113         while [ $# -gt 0 ]; do
114             arg="$1"
115             case "$arg" in
116             --)
117                 shift
118                 break
119                 ;;
120             *)
121                 rev=$(git rev-parse -q --verify "$arg^{commit}") || {
122                     test $has_double_dash -eq 1 &&
123                         die "'$arg' does not appear to be a valid revision"
124                     break
125                 }
126                 case $bad_seen in
127                 0) state='bad' ; bad_seen=1 ;;
128                 *) state='good' ;;
129                 esac
130                 eval="$eval bisect_write '$state' '$rev' 'nolog'; "
131                 shift
132                 ;;
133             esac
134         done
135
136         #
137         # Change state.
138         # In case of mistaken revs or checkout error, or signals received,
139         # "bisect_auto_next" below may exit or misbehave.
140         # We have to trap this to be able to clean up using
141         # "bisect_clean_state".
142         #
143         trap 'bisect_clean_state' 0
144         trap 'exit 255' 1 2 3 15
145
146         #
147         # Write new start state.
148         #
149         echo "$start_head" >"$GIT_DIR/BISECT_START" &&
150         sq "$@" >"$GIT_DIR/BISECT_NAMES" &&
151         eval "$eval" &&
152         echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
153         #
154         # Check if we can proceed to the next bisect state.
155         #
156         bisect_auto_next
157
158         trap '-' 0
159 }
160
161 bisect_write() {
162         state="$1"
163         rev="$2"
164         nolog="$3"
165         case "$state" in
166                 bad)            tag="$state" ;;
167                 good|skip)      tag="$state"-"$rev" ;;
168                 *)              die "Bad bisect_write argument: $state" ;;
169         esac
170         git update-ref "refs/bisect/$tag" "$rev" || exit
171         echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
172         test -n "$nolog" || echo "git bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
173 }
174
175 bisect_state() {
176         bisect_autostart
177         state=$1
178         case "$#,$state" in
179         0,*)
180                 die "Please call 'bisect_state' with at least one argument." ;;
181         1,bad|1,good|1,skip)
182                 rev=$(git rev-parse --verify HEAD) ||
183                         die "Bad rev input: HEAD"
184                 bisect_write "$state" "$rev" ;;
185         2,bad|*,good|*,skip)
186                 shift
187                 eval=''
188                 for rev in "$@"
189                 do
190                         sha=$(git rev-parse --verify "$rev^{commit}") ||
191                                 die "Bad rev input: $rev"
192                         eval="$eval bisect_write '$state' '$sha'; "
193                 done
194                 eval "$eval" ;;
195         *,bad)
196                 die "'git bisect bad' can take only one argument." ;;
197         *)
198                 usage ;;
199         esac
200         bisect_auto_next
201 }
202
203 bisect_next_check() {
204         missing_good= missing_bad=
205         git show-ref -q --verify refs/bisect/bad || missing_bad=t
206         test -n "$(git for-each-ref "refs/bisect/good-*")" || missing_good=t
207
208         case "$missing_good,$missing_bad,$1" in
209         ,,*)
210                 : have both good and bad - ok
211                 ;;
212         *,)
213                 # do not have both but not asked to fail - just report.
214                 false
215                 ;;
216         t,,good)
217                 # have bad but not good.  we could bisect although
218                 # this is less optimum.
219                 echo >&2 'Warning: bisecting only with a bad commit.'
220                 if test -t 0
221                 then
222                         printf >&2 'Are you sure [Y/n]? '
223                         read yesno
224                         case "$yesno" in [Nn]*) exit 1 ;; esac
225                 fi
226                 : bisect without good...
227                 ;;
228         *)
229                 THEN=''
230                 test -s "$GIT_DIR/BISECT_START" || {
231                         echo >&2 'You need to start by "git bisect start".'
232                         THEN='then '
233                 }
234                 echo >&2 'You '$THEN'need to give me at least one good' \
235                         'and one bad revisions.'
236                 echo >&2 '(You can use "git bisect bad" and' \
237                         '"git bisect good" for that.)'
238                 exit 1 ;;
239         esac
240 }
241
242 bisect_auto_next() {
243         bisect_next_check && bisect_next || :
244 }
245
246 eval_rev_list() {
247         _eval="$1"
248
249         eval $_eval
250         res=$?
251
252         if [ $res -ne 0 ]; then
253                 echo >&2 "'git rev-list --bisect-vars' failed:"
254                 echo >&2 "maybe you mistake good and bad revs?"
255                 exit $res
256         fi
257
258         return $res
259 }
260
261 filter_skipped() {
262         _eval="$1"
263         _skip="$2"
264
265         if [ -z "$_skip" ]; then
266                 eval_rev_list "$_eval"
267                 return
268         fi
269
270         # Let's parse the output of:
271         # "git rev-list --bisect-vars --bisect-all ..."
272         eval_rev_list "$_eval" | while read hash line
273         do
274                 case "$VARS,$FOUND,$TRIED,$hash" in
275                         # We display some vars.
276                         1,*,*,*) echo "$hash $line" ;;
277
278                         # Split line.
279                         ,*,*,---*) ;;
280
281                         # We had nothing to search.
282                         ,,,bisect_rev*)
283                                 echo "bisect_rev="
284                                 VARS=1
285                                 ;;
286
287                         # We did not find a good bisect rev.
288                         # This should happen only if the "bad"
289                         # commit is also a "skip" commit.
290                         ,,*,bisect_rev*)
291                                 echo "bisect_rev=$TRIED"
292                                 VARS=1
293                                 ;;
294
295                         # We are searching.
296                         ,,*,*)
297                                 TRIED="${TRIED:+$TRIED|}$hash"
298                                 case "$_skip" in
299                                 *$hash*) ;;
300                                 *)
301                                         echo "bisect_rev=$hash"
302                                         echo "bisect_tried=\"$TRIED\""
303                                         FOUND=1
304                                         ;;
305                                 esac
306                                 ;;
307
308                         # We have already found a rev to be tested.
309                         ,1,*,bisect_rev*) VARS=1 ;;
310                         ,1,*,*) ;;
311
312                         # ???
313                         *) die "filter_skipped error " \
314                             "VARS: '$VARS' " \
315                             "FOUND: '$FOUND' " \
316                             "TRIED: '$TRIED' " \
317                             "hash: '$hash' " \
318                             "line: '$line'"
319                         ;;
320                 esac
321         done
322 }
323
324 exit_if_skipped_commits () {
325         _tried=$1
326         if expr "$_tried" : ".*[|].*" > /dev/null ; then
327                 echo "There are only 'skip'ped commit left to test."
328                 echo "The first bad commit could be any of:"
329                 echo "$_tried" | tr '[|]' '[\012]'
330                 echo "We cannot bisect more!"
331                 exit 2
332         fi
333 }
334
335 bisect_next() {
336         case "$#" in 0) ;; *) usage ;; esac
337         bisect_autostart
338         bisect_next_check good
339
340         skip=$(git for-each-ref --format='%(objectname)' \
341                 "refs/bisect/skip-*" | tr '\012' ' ') || exit
342
343         BISECT_OPT=''
344         test -n "$skip" && BISECT_OPT='--bisect-all'
345
346         bad=$(git rev-parse --verify refs/bisect/bad) &&
347         good=$(git for-each-ref --format='^%(objectname)' \
348                 "refs/bisect/good-*" | tr '\012' ' ') &&
349         eval="git rev-list --bisect-vars $BISECT_OPT $good $bad --" &&
350         eval="$eval $(cat "$GIT_DIR/BISECT_NAMES")" &&
351         eval=$(filter_skipped "$eval" "$skip") &&
352         eval "$eval" || exit
353
354         if [ -z "$bisect_rev" ]; then
355                 echo "$bad was both good and bad"
356                 exit 1
357         fi
358         if [ "$bisect_rev" = "$bad" ]; then
359                 exit_if_skipped_commits "$bisect_tried"
360                 echo "$bisect_rev is first bad commit"
361                 git diff-tree --pretty $bisect_rev
362                 exit 0
363         fi
364
365         # We should exit here only if the "bad"
366         # commit is also a "skip" commit (see above).
367         exit_if_skipped_commits "$bisect_rev"
368
369         echo "Bisecting: $bisect_nr revisions left to test after this"
370         git checkout -q "$bisect_rev" || exit
371         git show-branch "$bisect_rev"
372 }
373
374 bisect_visualize() {
375         bisect_next_check fail
376
377         if test $# = 0
378         then
379                 case "${DISPLAY+set}${MSYSTEM+set}${SECURITYSESSIONID+set}" in
380                 '')     set git log ;;
381                 set*)   set gitk ;;
382                 esac
383         else
384                 case "$1" in
385                 git*|tig) ;;
386                 -*)     set git log "$@" ;;
387                 *)      set git "$@" ;;
388                 esac
389         fi
390
391         not=$(git for-each-ref --format='%(refname)' "refs/bisect/good-*")
392         eval '"$@"' refs/bisect/bad --not $not -- $(cat "$GIT_DIR/BISECT_NAMES")
393 }
394
395 bisect_reset() {
396         test -s "$GIT_DIR/BISECT_START" || {
397                 echo "We are not bisecting."
398                 return
399         }
400         case "$#" in
401         0) branch=$(cat "$GIT_DIR/BISECT_START") ;;
402         1) git show-ref --verify --quiet -- "refs/heads/$1" ||
403                die "$1 does not seem to be a valid branch"
404            branch="$1" ;;
405         *)
406             usage ;;
407         esac
408         git checkout "$branch" && bisect_clean_state
409 }
410
411 bisect_clean_state() {
412         # There may be some refs packed during bisection.
413         git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* |
414         while read ref hash
415         do
416                 git update-ref -d $ref $hash || exit
417         done
418         rm -f "$GIT_DIR/BISECT_LOG" &&
419         rm -f "$GIT_DIR/BISECT_NAMES" &&
420         rm -f "$GIT_DIR/BISECT_RUN" &&
421         # Cleanup head-name if it got left by an old version of git-bisect
422         rm -f "$GIT_DIR/head-name" &&
423
424         rm -f "$GIT_DIR/BISECT_START"
425 }
426
427 bisect_replay () {
428         test -r "$1" || die "cannot read $1 for replaying"
429         bisect_reset
430         while read git bisect command rev
431         do
432                 test "$git $bisect" = "git bisect" -o "$git" = "git-bisect" || continue
433                 if test "$git" = "git-bisect"; then
434                         rev="$command"
435                         command="$bisect"
436                 fi
437                 case "$command" in
438                 start)
439                         cmd="bisect_start $rev"
440                         eval "$cmd" ;;
441                 good|bad|skip)
442                         bisect_write "$command" "$rev" ;;
443                 *)
444                         die "?? what are you talking about?" ;;
445                 esac
446         done <"$1"
447         bisect_auto_next
448 }
449
450 bisect_run () {
451     bisect_next_check fail
452
453     while true
454     do
455       echo "running $@"
456       "$@"
457       res=$?
458
459       # Check for really bad run error.
460       if [ $res -lt 0 -o $res -ge 128 ]; then
461           echo >&2 "bisect run failed:"
462           echo >&2 "exit code $res from '$@' is < 0 or >= 128"
463           exit $res
464       fi
465
466       # Find current state depending on run success or failure.
467       # A special exit code of 125 means cannot test.
468       if [ $res -eq 125 ]; then
469           state='skip'
470       elif [ $res -gt 0 ]; then
471           state='bad'
472       else
473           state='good'
474       fi
475
476       # We have to use a subshell because "bisect_state" can exit.
477       ( bisect_state $state > "$GIT_DIR/BISECT_RUN" )
478       res=$?
479
480       cat "$GIT_DIR/BISECT_RUN"
481
482       if grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
483                 > /dev/null; then
484           echo >&2 "bisect run cannot continue any more"
485           exit $res
486       fi
487
488       if [ $res -ne 0 ]; then
489           echo >&2 "bisect run failed:"
490           echo >&2 "'bisect_state $state' exited with error code $res"
491           exit $res
492       fi
493
494       if grep "is first bad commit" "$GIT_DIR/BISECT_RUN" > /dev/null; then
495           echo "bisect run success"
496           exit 0;
497       fi
498
499     done
500 }
501
502
503 case "$#" in
504 0)
505     usage ;;
506 *)
507     cmd="$1"
508     shift
509     case "$cmd" in
510     help)
511         git bisect -h ;;
512     start)
513         bisect_start "$@" ;;
514     bad|good|skip)
515         bisect_state "$cmd" "$@" ;;
516     next)
517         # Not sure we want "next" at the UI level anymore.
518         bisect_next "$@" ;;
519     visualize|view)
520         bisect_visualize "$@" ;;
521     reset)
522         bisect_reset "$@" ;;
523     replay)
524         bisect_replay "$@" ;;
525     log)
526         cat "$GIT_DIR/BISECT_LOG" ;;
527     run)
528         bisect_run "$@" ;;
529     *)
530         usage ;;
531     esac
532 esac