summaryrefslogtreecommitdiff
path: root/git-bisect.sh
blob: df0ae63b4e40f9aa7373269e9a7fb7eeeb66cd18 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
#!/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>|<range>)...]
        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_skip() {
        all=''
	for arg in "$@"
	do
	    case "$arg" in
            *..*)
                revs=$(git rev-list "$arg") || die "Bad rev input: $arg" ;;
            *)
                revs=$(sq "$arg") ;;
	    esac
            all="$all $revs"
        done
        eval bisect_state 'skip' $all
}

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" | {
			while read line
			do
				echo "$line &&"
			done
			echo ':'
		}
		return
	fi

	# Let's parse the output of:
	# "git rev-list --bisect-vars --bisect-all ..."
	eval "$_eval" | {
		VARS= FOUND= TRIED=
		while read hash line
		do
			case "$VARS,$FOUND,$TRIED,$hash" in
			1,*,*,*)
				# "bisect_foo=bar" read from rev-list output.
				echo "$hash &&"
				;;
			,*,*,---*)
				# Separator
				;;
			,,,bisect_rev*)
				# We had nothing to search.
				echo "bisect_rev= &&"
				VARS=1
				;;
			,,*,bisect_rev*)
				# We did not find a good bisect rev.
				# This should happen only if the "bad"
				# commit is also a "skip" commit.
				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
				;;
			,1,*,bisect_rev*)
				# We have already found a rev to be tested.
				VARS=1
				;;
			,1,*,*)
				;;
			*)
				# Unexpected input
				echo "die 'filter_skipped error'"
				die "filter_skipped error " \
				    "VARS: '$VARS' " \
				    "FOUND: '$FOUND' " \
				    "TRIED: '$TRIED' " \
				    "hash: '$hash' " \
				    "line: '$line'"
				;;
			esac
		done
		echo ':'
	}
}

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' ' ') || exit

	# 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 (roughly $bisect_steps steps)"
}

bisect_visualize() {
	bisect_next_check fail

	if test $# = 0
	then
		case "${DISPLAY+set}${SESSIONNAME+set}${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 "$@" ;;
    bad|good)
        bisect_state "$cmd" "$@" ;;
    skip)
        bisect_skip "$@" ;;
    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