summaryrefslogtreecommitdiff
path: root/builtin/blame.c
blob: 7d9e322d4571e9cbc5cac9289922e9584f7f6573 (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
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
/*
 * Blame
 *
 * Copyright (c) 2006, 2014 by its authors
 * See COPYING for licensing conditions
 */

#include "cache.h"
#include "builtin.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "quote.h"
#include "string-list.h"
#include "mailmap.h"
#include "parse-options.h"
#include "prio-queue.h"
#include "utf8.h"
#include "userdiff.h"
#include "line-range.h"
#include "line-log.h"
#include "dir.h"
#include "progress.h"
#include "blame.h"

static char blame_usage[] = N_("git blame [<options>] [<rev-opts>] [<rev>] [--] <file>");

static const char *blame_opt_usage[] = {
	blame_usage,
	"",
	N_("<rev-opts> are documented in git-rev-list(1)"),
	NULL
};

static int longest_file;
static int longest_author;
static int max_orig_digits;
static int max_digits;
static int max_score_digits;
static int show_root;
static int reverse;
static int blank_boundary;
static int incremental;
static int xdl_opts;
static int abbrev = -1;
static int no_whole_file_rename;
static int show_progress;

static struct date_mode blame_date_mode = { DATE_ISO8601 };
static size_t blame_date_width;

static struct string_list mailmap = STRING_LIST_INIT_NODUP;

#ifndef DEBUG
#define DEBUG 0
#endif

static unsigned blame_move_score;
static unsigned blame_copy_score;

/* Remember to update object flag allocation in object.h */
#define METAINFO_SHOWN		(1u<<12)
#define MORE_THAN_ONE_PATH	(1u<<13)

struct progress_info {
	struct progress *progress;
	int blamed_lines;
};

static const char *nth_line_cb(void *data, long lno)
{
	return blame_nth_line((struct blame_scoreboard *)data, lno);
}

/*
 * Information on commits, used for output.
 */
struct commit_info {
	struct strbuf author;
	struct strbuf author_mail;
	timestamp_t author_time;
	struct strbuf author_tz;

	/* filled only when asked for details */
	struct strbuf committer;
	struct strbuf committer_mail;
	timestamp_t committer_time;
	struct strbuf committer_tz;

	struct strbuf summary;
};

/*
 * Parse author/committer line in the commit object buffer
 */
static void get_ac_line(const char *inbuf, const char *what,
	struct strbuf *name, struct strbuf *mail,
	timestamp_t *time, struct strbuf *tz)
{
	struct ident_split ident;
	size_t len, maillen, namelen;
	char *tmp, *endp;
	const char *namebuf, *mailbuf;

	tmp = strstr(inbuf, what);
	if (!tmp)
		goto error_out;
	tmp += strlen(what);
	endp = strchr(tmp, '\n');
	if (!endp)
		len = strlen(tmp);
	else
		len = endp - tmp;

	if (split_ident_line(&ident, tmp, len)) {
	error_out:
		/* Ugh */
		tmp = "(unknown)";
		strbuf_addstr(name, tmp);
		strbuf_addstr(mail, tmp);
		strbuf_addstr(tz, tmp);
		*time = 0;
		return;
	}

	namelen = ident.name_end - ident.name_begin;
	namebuf = ident.name_begin;

	maillen = ident.mail_end - ident.mail_begin;
	mailbuf = ident.mail_begin;

	if (ident.date_begin && ident.date_end)
		*time = strtoul(ident.date_begin, NULL, 10);
	else
		*time = 0;

	if (ident.tz_begin && ident.tz_end)
		strbuf_add(tz, ident.tz_begin, ident.tz_end - ident.tz_begin);
	else
		strbuf_addstr(tz, "(unknown)");

	/*
	 * Now, convert both name and e-mail using mailmap
	 */
	map_user(&mailmap, &mailbuf, &maillen,
		 &namebuf, &namelen);

	strbuf_addf(mail, "<%.*s>", (int)maillen, mailbuf);
	strbuf_add(name, namebuf, namelen);
}

static void commit_info_init(struct commit_info *ci)
{

	strbuf_init(&ci->author, 0);
	strbuf_init(&ci->author_mail, 0);
	strbuf_init(&ci->author_tz, 0);
	strbuf_init(&ci->committer, 0);
	strbuf_init(&ci->committer_mail, 0);
	strbuf_init(&ci->committer_tz, 0);
	strbuf_init(&ci->summary, 0);
}

static void commit_info_destroy(struct commit_info *ci)
{

	strbuf_release(&ci->author);
	strbuf_release(&ci->author_mail);
	strbuf_release(&ci->author_tz);
	strbuf_release(&ci->committer);
	strbuf_release(&ci->committer_mail);
	strbuf_release(&ci->committer_tz);
	strbuf_release(&ci->summary);
}

static void get_commit_info(struct commit *commit,
			    struct commit_info *ret,
			    int detailed)
{
	int len;
	const char *subject, *encoding;
	const char *message;

	commit_info_init(ret);

	encoding = get_log_output_encoding();
	message = logmsg_reencode(commit, NULL, encoding);
	get_ac_line(message, "\nauthor ",
		    &ret->author, &ret->author_mail,
		    &ret->author_time, &ret->author_tz);

	if (!detailed) {
		unuse_commit_buffer(commit, message);
		return;
	}

	get_ac_line(message, "\ncommitter ",
		    &ret->committer, &ret->committer_mail,
		    &ret->committer_time, &ret->committer_tz);

	len = find_commit_subject(message, &subject);
	if (len)
		strbuf_add(&ret->summary, subject, len);
	else
		strbuf_addf(&ret->summary, "(%s)", oid_to_hex(&commit->object.oid));

	unuse_commit_buffer(commit, message);
}

/*
 * Write out any suspect information which depends on the path. This must be
 * handled separately from emit_one_suspect_detail(), because a given commit
 * may have changes in multiple paths. So this needs to appear each time
 * we mention a new group.
 *
 * To allow LF and other nonportable characters in pathnames,
 * they are c-style quoted as needed.
 */
static void write_filename_info(struct blame_origin *suspect)
{
	if (suspect->previous) {
		struct blame_origin *prev = suspect->previous;
		printf("previous %s ", oid_to_hex(&prev->commit->object.oid));
		write_name_quoted(prev->path, stdout, '\n');
	}
	printf("filename ");
	write_name_quoted(suspect->path, stdout, '\n');
}

/*
 * Porcelain/Incremental format wants to show a lot of details per
 * commit.  Instead of repeating this every line, emit it only once,
 * the first time each commit appears in the output (unless the
 * user has specifically asked for us to repeat).
 */
static int emit_one_suspect_detail(struct blame_origin *suspect, int repeat)
{
	struct commit_info ci;

	if (!repeat && (suspect->commit->object.flags & METAINFO_SHOWN))
		return 0;

	suspect->commit->object.flags |= METAINFO_SHOWN;
	get_commit_info(suspect->commit, &ci, 1);
	printf("author %s\n", ci.author.buf);
	printf("author-mail %s\n", ci.author_mail.buf);
	printf("author-time %"PRItime"\n", ci.author_time);
	printf("author-tz %s\n", ci.author_tz.buf);
	printf("committer %s\n", ci.committer.buf);
	printf("committer-mail %s\n", ci.committer_mail.buf);
	printf("committer-time %"PRItime"\n", ci.committer_time);
	printf("committer-tz %s\n", ci.committer_tz.buf);
	printf("summary %s\n", ci.summary.buf);
	if (suspect->commit->object.flags & UNINTERESTING)
		printf("boundary\n");

	commit_info_destroy(&ci);

	return 1;
}

/*
 * The blame_entry is found to be guilty for the range.
 * Show it in incremental output.
 */
static void found_guilty_entry(struct blame_entry *ent, void *data)
{
	struct progress_info *pi = (struct progress_info *)data;

	if (incremental) {
		struct blame_origin *suspect = ent->suspect;

		printf("%s %d %d %d\n",
		       oid_to_hex(&suspect->commit->object.oid),
		       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
		emit_one_suspect_detail(suspect, 0);
		write_filename_info(suspect);
		maybe_flush_or_die(stdout, "stdout");
	}
	pi->blamed_lines += ent->num_lines;
	display_progress(pi->progress, pi->blamed_lines);
}

static const char *format_time(timestamp_t time, const char *tz_str,
			       int show_raw_time)
{
	static struct strbuf time_buf = STRBUF_INIT;

	strbuf_reset(&time_buf);
	if (show_raw_time) {
		strbuf_addf(&time_buf, "%"PRItime" %s", time, tz_str);
	}
	else {
		const char *time_str;
		size_t time_width;
		int tz;
		tz = atoi(tz_str);
		time_str = show_date(time, tz, &blame_date_mode);
		strbuf_addstr(&time_buf, time_str);
		/*
		 * Add space paddings to time_buf to display a fixed width
		 * string, and use time_width for display width calibration.
		 */
		for (time_width = utf8_strwidth(time_str);
		     time_width < blame_date_width;
		     time_width++)
			strbuf_addch(&time_buf, ' ');
	}
	return time_buf.buf;
}

#define OUTPUT_ANNOTATE_COMPAT	001
#define OUTPUT_LONG_OBJECT_NAME	002
#define OUTPUT_RAW_TIMESTAMP	004
#define OUTPUT_PORCELAIN	010
#define OUTPUT_SHOW_NAME	020
#define OUTPUT_SHOW_NUMBER	040
#define OUTPUT_SHOW_SCORE      0100
#define OUTPUT_NO_AUTHOR       0200
#define OUTPUT_SHOW_EMAIL	0400
#define OUTPUT_LINE_PORCELAIN 01000

static void emit_porcelain_details(struct blame_origin *suspect, int repeat)
{
	if (emit_one_suspect_detail(suspect, repeat) ||
	    (suspect->commit->object.flags & MORE_THAN_ONE_PATH))
		write_filename_info(suspect);
}

static void emit_porcelain(struct blame_scoreboard *sb, struct blame_entry *ent,
			   int opt)
{
	int repeat = opt & OUTPUT_LINE_PORCELAIN;
	int cnt;
	const char *cp;
	struct blame_origin *suspect = ent->suspect;
	char hex[GIT_MAX_HEXSZ + 1];

	oid_to_hex_r(hex, &suspect->commit->object.oid);
	printf("%s %d %d %d\n",
	       hex,
	       ent->s_lno + 1,
	       ent->lno + 1,
	       ent->num_lines);
	emit_porcelain_details(suspect, repeat);

	cp = blame_nth_line(sb, ent->lno);
	for (cnt = 0; cnt < ent->num_lines; cnt++) {
		char ch;
		if (cnt) {
			printf("%s %d %d\n", hex,
			       ent->s_lno + 1 + cnt,
			       ent->lno + 1 + cnt);
			if (repeat)
				emit_porcelain_details(suspect, 1);
		}
		putchar('\t');
		do {
			ch = *cp++;
			putchar(ch);
		} while (ch != '\n' &&
			 cp < sb->final_buf + sb->final_buf_size);
	}

	if (sb->final_buf_size && cp[-1] != '\n')
		putchar('\n');
}

static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent, int opt)
{
	int cnt;
	const char *cp;
	struct blame_origin *suspect = ent->suspect;
	struct commit_info ci;
	char hex[GIT_MAX_HEXSZ + 1];
	int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);

	get_commit_info(suspect->commit, &ci, 1);
	oid_to_hex_r(hex, &suspect->commit->object.oid);

	cp = blame_nth_line(sb, ent->lno);
	for (cnt = 0; cnt < ent->num_lines; cnt++) {
		char ch;
		int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? GIT_SHA1_HEXSZ : abbrev;

		if (suspect->commit->object.flags & UNINTERESTING) {
			if (blank_boundary)
				memset(hex, ' ', length);
			else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
				length--;
				putchar('^');
			}
		}

		printf("%.*s", length, hex);
		if (opt & OUTPUT_ANNOTATE_COMPAT) {
			const char *name;
			if (opt & OUTPUT_SHOW_EMAIL)
				name = ci.author_mail.buf;
			else
				name = ci.author.buf;
			printf("\t(%10s\t%10s\t%d)", name,
			       format_time(ci.author_time, ci.author_tz.buf,
					   show_raw_time),
			       ent->lno + 1 + cnt);
		} else {
			if (opt & OUTPUT_SHOW_SCORE)
				printf(" %*d %02d",
				       max_score_digits, ent->score,
				       ent->suspect->refcnt);
			if (opt & OUTPUT_SHOW_NAME)
				printf(" %-*.*s", longest_file, longest_file,
				       suspect->path);
			if (opt & OUTPUT_SHOW_NUMBER)
				printf(" %*d", max_orig_digits,
				       ent->s_lno + 1 + cnt);

			if (!(opt & OUTPUT_NO_AUTHOR)) {
				const char *name;
				int pad;
				if (opt & OUTPUT_SHOW_EMAIL)
					name = ci.author_mail.buf;
				else
					name = ci.author.buf;
				pad = longest_author - utf8_strwidth(name);
				printf(" (%s%*s %10s",
				       name, pad, "",
				       format_time(ci.author_time,
						   ci.author_tz.buf,
						   show_raw_time));
			}
			printf(" %*d) ",
			       max_digits, ent->lno + 1 + cnt);
		}
		do {
			ch = *cp++;
			putchar(ch);
		} while (ch != '\n' &&
			 cp < sb->final_buf + sb->final_buf_size);
	}

	if (sb->final_buf_size && cp[-1] != '\n')
		putchar('\n');

	commit_info_destroy(&ci);
}

static void output(struct blame_scoreboard *sb, int option)
{
	struct blame_entry *ent;

	if (option & OUTPUT_PORCELAIN) {
		for (ent = sb->ent; ent; ent = ent->next) {
			int count = 0;
			struct blame_origin *suspect;
			struct commit *commit = ent->suspect->commit;
			if (commit->object.flags & MORE_THAN_ONE_PATH)
				continue;
			for (suspect = commit->util; suspect; suspect = suspect->next) {
				if (suspect->guilty && count++) {
					commit->object.flags |= MORE_THAN_ONE_PATH;
					break;
				}
			}
		}
	}

	for (ent = sb->ent; ent; ent = ent->next) {
		if (option & OUTPUT_PORCELAIN)
			emit_porcelain(sb, ent, option);
		else {
			emit_other(sb, ent, option);
		}
	}
}

/*
 * Add phony grafts for use with -S; this is primarily to
 * support git's cvsserver that wants to give a linear history
 * to its clients.
 */
static int read_ancestry(const char *graft_file)
{
	FILE *fp = fopen(graft_file, "r");
	struct strbuf buf = STRBUF_INIT;
	if (!fp)
		return -1;
	while (!strbuf_getwholeline(&buf, fp, '\n')) {
		/* The format is just "Commit Parent1 Parent2 ...\n" */
		struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
		if (graft)
			register_commit_graft(graft, 0);
	}
	fclose(fp);
	strbuf_release(&buf);
	return 0;
}

static int update_auto_abbrev(int auto_abbrev, struct blame_origin *suspect)
{
	const char *uniq = find_unique_abbrev(suspect->commit->object.oid.hash,
					      auto_abbrev);
	int len = strlen(uniq);
	if (auto_abbrev < len)
		return len;
	return auto_abbrev;
}

/*
 * How many columns do we need to show line numbers, authors,
 * and filenames?
 */
static void find_alignment(struct blame_scoreboard *sb, int *option)
{
	int longest_src_lines = 0;
	int longest_dst_lines = 0;
	unsigned largest_score = 0;
	struct blame_entry *e;
	int compute_auto_abbrev = (abbrev < 0);
	int auto_abbrev = DEFAULT_ABBREV;

	for (e = sb->ent; e; e = e->next) {
		struct blame_origin *suspect = e->suspect;
		int num;

		if (compute_auto_abbrev)
			auto_abbrev = update_auto_abbrev(auto_abbrev, suspect);
		if (strcmp(suspect->path, sb->path))
			*option |= OUTPUT_SHOW_NAME;
		num = strlen(suspect->path);
		if (longest_file < num)
			longest_file = num;
		if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
			struct commit_info ci;
			suspect->commit->object.flags |= METAINFO_SHOWN;
			get_commit_info(suspect->commit, &ci, 1);
			if (*option & OUTPUT_SHOW_EMAIL)
				num = utf8_strwidth(ci.author_mail.buf);
			else
				num = utf8_strwidth(ci.author.buf);
			if (longest_author < num)
				longest_author = num;
			commit_info_destroy(&ci);
		}
		num = e->s_lno + e->num_lines;
		if (longest_src_lines < num)
			longest_src_lines = num;
		num = e->lno + e->num_lines;
		if (longest_dst_lines < num)
			longest_dst_lines = num;
		if (largest_score < blame_entry_score(sb, e))
			largest_score = blame_entry_score(sb, e);
	}
	max_orig_digits = decimal_width(longest_src_lines);
	max_digits = decimal_width(longest_dst_lines);
	max_score_digits = decimal_width(largest_score);

	if (compute_auto_abbrev)
		/* one more abbrev length is needed for the boundary commit */
		abbrev = auto_abbrev + 1;
}

static void sanity_check_on_fail(struct blame_scoreboard *sb, int baa)
{
	int opt = OUTPUT_SHOW_SCORE | OUTPUT_SHOW_NUMBER | OUTPUT_SHOW_NAME;
	find_alignment(sb, &opt);
	output(sb, opt);
	die("Baa %d!", baa);
}

static unsigned parse_score(const char *arg)
{
	char *end;
	unsigned long score = strtoul(arg, &end, 10);
	if (*end)
		return 0;
	return score;
}

static const char *add_prefix(const char *prefix, const char *path)
{
	return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
}

static int git_blame_config(const char *var, const char *value, void *cb)
{
	if (!strcmp(var, "blame.showroot")) {
		show_root = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp(var, "blame.blankboundary")) {
		blank_boundary = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp(var, "blame.showemail")) {
		int *output_option = cb;
		if (git_config_bool(var, value))
			*output_option |= OUTPUT_SHOW_EMAIL;
		else
			*output_option &= ~OUTPUT_SHOW_EMAIL;
		return 0;
	}
	if (!strcmp(var, "blame.date")) {
		if (!value)
			return config_error_nonbool(var);
		parse_date_format(value, &blame_date_mode);
		return 0;
	}

	if (git_diff_heuristic_config(var, value, cb) < 0)
		return -1;
	if (userdiff_config(var, value) < 0)
		return -1;

	return git_default_config(var, value, cb);
}

static int blame_copy_callback(const struct option *option, const char *arg, int unset)
{
	int *opt = option->value;

	/*
	 * -C enables copy from removed files;
	 * -C -C enables copy from existing files, but only
	 *       when blaming a new file;
	 * -C -C -C enables copy from existing files for
	 *          everybody
	 */
	if (*opt & PICKAXE_BLAME_COPY_HARDER)
		*opt |= PICKAXE_BLAME_COPY_HARDEST;
	if (*opt & PICKAXE_BLAME_COPY)
		*opt |= PICKAXE_BLAME_COPY_HARDER;
	*opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;

	if (arg)
		blame_copy_score = parse_score(arg);
	return 0;
}

static int blame_move_callback(const struct option *option, const char *arg, int unset)
{
	int *opt = option->value;

	*opt |= PICKAXE_BLAME_MOVE;

	if (arg)
		blame_move_score = parse_score(arg);
	return 0;
}

struct blame_entry *blame_entry_prepend(struct blame_entry *head,
					long start, long end,
					struct blame_origin *o)
{
	struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry));
	new_head->lno = start;
	new_head->num_lines = end - start;
	new_head->suspect = o;
	new_head->s_lno = start;
	new_head->next = head;
	blame_origin_incref(o);
	return new_head;
}

int cmd_blame(int argc, const char **argv, const char *prefix)
{
	struct rev_info revs;
	const char *path;
	struct blame_scoreboard sb;
	struct blame_origin *o;
	struct blame_entry *ent = NULL;
	long dashdash_pos, lno;
	struct progress_info pi = { NULL, 0 };

	struct string_list range_list = STRING_LIST_INIT_NODUP;
	int output_option = 0, opt = 0;
	int show_stats = 0;
	const char *revs_file = NULL;
	const char *contents_from = NULL;
	const struct option options[] = {
		OPT_BOOL(0, "incremental", &incremental, N_("Show blame entries as we find them, incrementally")),
		OPT_BOOL('b', NULL, &blank_boundary, N_("Show blank SHA-1 for boundary commits (Default: off)")),
		OPT_BOOL(0, "root", &show_root, N_("Do not treat root commits as boundaries (Default: off)")),
		OPT_BOOL(0, "show-stats", &show_stats, N_("Show work cost statistics")),
		OPT_BOOL(0, "progress", &show_progress, N_("Force progress reporting")),
		OPT_BIT(0, "score-debug", &output_option, N_("Show output score for blame entries"), OUTPUT_SHOW_SCORE),
		OPT_BIT('f', "show-name", &output_option, N_("Show original filename (Default: auto)"), OUTPUT_SHOW_NAME),
		OPT_BIT('n', "show-number", &output_option, N_("Show original linenumber (Default: off)"), OUTPUT_SHOW_NUMBER),
		OPT_BIT('p', "porcelain", &output_option, N_("Show in a format designed for machine consumption"), OUTPUT_PORCELAIN),
		OPT_BIT(0, "line-porcelain", &output_option, N_("Show porcelain format with per-line commit information"), OUTPUT_PORCELAIN|OUTPUT_LINE_PORCELAIN),
		OPT_BIT('c', NULL, &output_option, N_("Use the same output mode as git-annotate (Default: off)"), OUTPUT_ANNOTATE_COMPAT),
		OPT_BIT('t', NULL, &output_option, N_("Show raw timestamp (Default: off)"), OUTPUT_RAW_TIMESTAMP),
		OPT_BIT('l', NULL, &output_option, N_("Show long commit SHA1 (Default: off)"), OUTPUT_LONG_OBJECT_NAME),
		OPT_BIT('s', NULL, &output_option, N_("Suppress author name and timestamp (Default: off)"), OUTPUT_NO_AUTHOR),
		OPT_BIT('e', "show-email", &output_option, N_("Show author email instead of name (Default: off)"), OUTPUT_SHOW_EMAIL),
		OPT_BIT('w', NULL, &xdl_opts, N_("Ignore whitespace differences"), XDF_IGNORE_WHITESPACE),

		/*
		 * The following two options are parsed by parse_revision_opt()
		 * and are only included here to get included in the "-h"
		 * output:
		 */
		{ OPTION_LOWLEVEL_CALLBACK, 0, "indent-heuristic", NULL, NULL, N_("Use an experimental heuristic to improve diffs"), PARSE_OPT_NOARG, parse_opt_unknown_cb },

		OPT_BIT(0, "minimal", &xdl_opts, N_("Spend extra cycles to find better match"), XDF_NEED_MINIMAL),
		OPT_STRING('S', NULL, &revs_file, N_("file"), N_("Use revisions from <file> instead of calling git-rev-list")),
		OPT_STRING(0, "contents", &contents_from, N_("file"), N_("Use <file>'s contents as the final image")),
		{ OPTION_CALLBACK, 'C', NULL, &opt, N_("score"), N_("Find line copies within and across files"), PARSE_OPT_OPTARG, blame_copy_callback },
		{ OPTION_CALLBACK, 'M', NULL, &opt, N_("score"), N_("Find line movements within and across files"), PARSE_OPT_OPTARG, blame_move_callback },
		OPT_STRING_LIST('L', NULL, &range_list, N_("n,m"), N_("Process only line range n,m, counting from 1")),
		OPT__ABBREV(&abbrev),
		OPT_END()
	};

	struct parse_opt_ctx_t ctx;
	int cmd_is_annotate = !strcmp(argv[0], "annotate");
	struct range_set ranges;
	unsigned int range_i;
	long anchor;

	git_config(git_blame_config, &output_option);
	init_revisions(&revs, NULL);
	revs.date_mode = blame_date_mode;
	DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
	DIFF_OPT_SET(&revs.diffopt, FOLLOW_RENAMES);

	save_commit_buffer = 0;
	dashdash_pos = 0;
	show_progress = -1;

	parse_options_start(&ctx, argc, argv, prefix, options,
			    PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_ARGV0);
	for (;;) {
		switch (parse_options_step(&ctx, options, blame_opt_usage)) {
		case PARSE_OPT_HELP:
			exit(129);
		case PARSE_OPT_DONE:
			if (ctx.argv[0])
				dashdash_pos = ctx.cpidx;
			goto parse_done;
		}

		if (!strcmp(ctx.argv[0], "--reverse")) {
			ctx.argv[0] = "--children";
			reverse = 1;
		}
		parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
	}
parse_done:
	no_whole_file_rename = !DIFF_OPT_TST(&revs.diffopt, FOLLOW_RENAMES);
	xdl_opts |= revs.diffopt.xdl_opts & XDF_INDENT_HEURISTIC;
	DIFF_OPT_CLR(&revs.diffopt, FOLLOW_RENAMES);
	argc = parse_options_end(&ctx);

	if (incremental || (output_option & OUTPUT_PORCELAIN)) {
		if (show_progress > 0)
			die(_("--progress can't be used with --incremental or porcelain formats"));
		show_progress = 0;
	} else if (show_progress < 0)
		show_progress = isatty(2);

	if (0 < abbrev && abbrev < GIT_SHA1_HEXSZ)
		/* one more abbrev length is needed for the boundary commit */
		abbrev++;
	else if (!abbrev)
		abbrev = GIT_SHA1_HEXSZ;

	if (revs_file && read_ancestry(revs_file))
		die_errno("reading graft file '%s' failed", revs_file);

	if (cmd_is_annotate) {
		output_option |= OUTPUT_ANNOTATE_COMPAT;
		blame_date_mode.type = DATE_ISO8601;
	} else {
		blame_date_mode = revs.date_mode;
	}

	/* The maximum width used to show the dates */
	switch (blame_date_mode.type) {
	case DATE_RFC2822:
		blame_date_width = sizeof("Thu, 19 Oct 2006 16:00:04 -0700");
		break;
	case DATE_ISO8601_STRICT:
		blame_date_width = sizeof("2006-10-19T16:00:04-07:00");
		break;
	case DATE_ISO8601:
		blame_date_width = sizeof("2006-10-19 16:00:04 -0700");
		break;
	case DATE_RAW:
		blame_date_width = sizeof("1161298804 -0700");
		break;
	case DATE_UNIX:
		blame_date_width = sizeof("1161298804");
		break;
	case DATE_SHORT:
		blame_date_width = sizeof("2006-10-19");
		break;
	case DATE_RELATIVE:
		/* TRANSLATORS: This string is used to tell us the maximum
		   display width for a relative timestamp in "git blame"
		   output.  For C locale, "4 years, 11 months ago", which
		   takes 22 places, is the longest among various forms of
		   relative timestamps, but your language may need more or
		   fewer display columns. */
		blame_date_width = utf8_strwidth(_("4 years, 11 months ago")) + 1; /* add the null */
		break;
	case DATE_NORMAL:
		blame_date_width = sizeof("Thu Oct 19 16:00:04 2006 -0700");
		break;
	case DATE_STRFTIME:
		blame_date_width = strlen(show_date(0, 0, &blame_date_mode)) + 1; /* add the null */
		break;
	}
	blame_date_width -= 1; /* strip the null */

	if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
		opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
			PICKAXE_BLAME_COPY_HARDER);

	/*
	 * We have collected options unknown to us in argv[1..unk]
	 * which are to be passed to revision machinery if we are
	 * going to do the "bottom" processing.
	 *
	 * The remaining are:
	 *
	 * (1) if dashdash_pos != 0, it is either
	 *     "blame [revisions] -- <path>" or
	 *     "blame -- <path> <rev>"
	 *
	 * (2) otherwise, it is one of the two:
	 *     "blame [revisions] <path>"
	 *     "blame <path> <rev>"
	 *
	 * Note that we must strip out <path> from the arguments: we do not
	 * want the path pruning but we may want "bottom" processing.
	 */
	if (dashdash_pos) {
		switch (argc - dashdash_pos - 1) {
		case 2: /* (1b) */
			if (argc != 4)
				usage_with_options(blame_opt_usage, options);
			/* reorder for the new way: <rev> -- <path> */
			argv[1] = argv[3];
			argv[3] = argv[2];
			argv[2] = "--";
			/* FALLTHROUGH */
		case 1: /* (1a) */
			path = add_prefix(prefix, argv[--argc]);
			argv[argc] = NULL;
			break;
		default:
			usage_with_options(blame_opt_usage, options);
		}
	} else {
		if (argc < 2)
			usage_with_options(blame_opt_usage, options);
		path = add_prefix(prefix, argv[argc - 1]);
		if (argc == 3 && !file_exists(path)) { /* (2b) */
			path = add_prefix(prefix, argv[1]);
			argv[1] = argv[2];
		}
		argv[argc - 1] = "--";

		setup_work_tree();
		if (!file_exists(path))
			die_errno("cannot stat path '%s'", path);
	}

	revs.disable_stdin = 1;
	setup_revisions(argc, argv, &revs, NULL);

	init_scoreboard(&sb);
	sb.revs = &revs;
	sb.contents_from = contents_from;
	sb.reverse = reverse;
	setup_scoreboard(&sb, path, &o);
	lno = sb.num_lines;

	if (lno && !range_list.nr)
		string_list_append(&range_list, "1");

	anchor = 1;
	range_set_init(&ranges, range_list.nr);
	for (range_i = 0; range_i < range_list.nr; ++range_i) {
		long bottom, top;
		if (parse_range_arg(range_list.items[range_i].string,
				    nth_line_cb, &sb, lno, anchor,
				    &bottom, &top, sb.path))
			usage(blame_usage);
		if (lno < top || ((lno || bottom) && lno < bottom))
			die(Q_("file %s has only %lu line",
			       "file %s has only %lu lines",
			       lno), path, lno);
		if (bottom < 1)
			bottom = 1;
		if (top < 1)
			top = lno;
		bottom--;
		range_set_append_unsafe(&ranges, bottom, top);
		anchor = top + 1;
	}
	sort_and_merge_range_set(&ranges);

	for (range_i = ranges.nr; range_i > 0; --range_i) {
		const struct range *r = &ranges.ranges[range_i - 1];
		ent = blame_entry_prepend(ent, r->start, r->end, o);
	}

	o->suspects = ent;
	prio_queue_put(&sb.commits, o->commit);

	blame_origin_decref(o);

	range_set_release(&ranges);
	string_list_clear(&range_list, 0);

	sb.ent = NULL;
	sb.path = path;

	if (blame_move_score)
		sb.move_score = blame_move_score;
	if (blame_copy_score)
		sb.copy_score = blame_copy_score;

	sb.debug = DEBUG;
	sb.on_sanity_fail = &sanity_check_on_fail;

	sb.show_root = show_root;
	sb.xdl_opts = xdl_opts;
	sb.no_whole_file_rename = no_whole_file_rename;

	read_mailmap(&mailmap, NULL);

	sb.found_guilty_entry = &found_guilty_entry;
	sb.found_guilty_entry_data = &pi;
	if (show_progress)
		pi.progress = start_progress_delay(_("Blaming lines"),
						   sb.num_lines, 50, 1);

	assign_blame(&sb, opt);

	stop_progress(&pi.progress);

	if (!incremental)
		setup_pager();
	else
		return 0;

	blame_sort_final(&sb);

	blame_coalesce(&sb);

	if (!(output_option & OUTPUT_PORCELAIN))
		find_alignment(&sb, &output_option);

	output(&sb, output_option);
	free((void *)sb.final_buf);
	for (ent = sb.ent; ent; ) {
		struct blame_entry *e = ent->next;
		free(ent);
		ent = e;
	}

	if (show_stats) {
		printf("num read blob: %d\n", sb.num_read_blob);
		printf("num get patch: %d\n", sb.num_get_patch);
		printf("num commits: %d\n", sb.num_commits);
	}
	return 0;
}