summaryrefslogtreecommitdiff
path: root/line-log.c
blob: 24e21731c4315f414578b33178a7b784176bb24d (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
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
#include "git-compat-util.h"
#include "line-range.h"
#include "cache.h"
#include "tag.h"
#include "blob.h"
#include "tree.h"
#include "diff.h"
#include "commit.h"
#include "decorate.h"
#include "revision.h"
#include "xdiff-interface.h"
#include "strbuf.h"
#include "log-tree.h"
#include "graph.h"
#include "userdiff.h"
#include "line-log.h"
#include "argv-array.h"
 
static void range_set_grow(struct range_set *rs, size_t extra)
{
	ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
}
 
/* Either initialization would be fine */
#define RANGE_SET_INIT {0}
 
void range_set_init(struct range_set *rs, size_t prealloc)
{
	rs->alloc = rs->nr = 0;
	rs->ranges = NULL;
	if (prealloc)
		range_set_grow(rs, prealloc);
}
 
void range_set_release(struct range_set *rs)
{
	FREE_AND_NULL(rs->ranges);
	rs->alloc = rs->nr = 0;
}
 
/* dst must be uninitialized! */
static void range_set_copy(struct range_set *dst, struct range_set *src)
{
	range_set_init(dst, src->nr);
	COPY_ARRAY(dst->ranges, src->ranges, src->nr);
	dst->nr = src->nr;
}
 
static void range_set_move(struct range_set *dst, struct range_set *src)
{
	range_set_release(dst);
	dst->ranges = src->ranges;
	dst->nr = src->nr;
	dst->alloc = src->alloc;
	src->ranges = NULL;
	src->alloc = src->nr = 0;
}
 
/* tack on a _new_ range _at the end_ */
void range_set_append_unsafe(struct range_set *rs, long a, long b)
{
	assert(a <= b);
	range_set_grow(rs, 1);
	rs->ranges[rs->nr].start = a;
	rs->ranges[rs->nr].end = b;
	rs->nr++;
}
 
void range_set_append(struct range_set *rs, long a, long b)
{
	assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
	range_set_append_unsafe(rs, a, b);
}
 
static int range_cmp(const void *_r, const void *_s)
{
	const struct range *r = _r;
	const struct range *s = _s;
 
	/* this could be simply 'return r.start-s.start', but for the types */
	if (r->start == s->start)
		return 0;
	if (r->start < s->start)
		return -1;
	return 1;
}
 
/*
 * Check that the ranges are non-empty, sorted and non-overlapping
 */
static void range_set_check_invariants(struct range_set *rs)
{
	unsigned int i;
 
	if (!rs)
		return;
 
	if (rs->nr)
		assert(rs->ranges[0].start < rs->ranges[0].end);
 
	for (i = 1; i < rs->nr; i++) {
		assert(rs->ranges[i-1].end < rs->ranges[i].start);
		assert(rs->ranges[i].start < rs->ranges[i].end);
	}
}
 
/*
 * In-place pass of sorting and merging the ranges in the range set,
 * to establish the invariants when we get the ranges from the user
 */
void sort_and_merge_range_set(struct range_set *rs)
{
	unsigned int i;
	unsigned int o = 0; /* output cursor */
 
	QSORT(rs->ranges, rs->nr, range_cmp);
 
	for (i = 0; i < rs->nr; i++) {
		if (rs->ranges[i].start == rs->ranges[i].end)
			continue;
		if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
			if (rs->ranges[o-1].end < rs->ranges[i].end)
				rs->ranges[o-1].end = rs->ranges[i].end;
		} else {
			rs->ranges[o].start = rs->ranges[i].start;
			rs->ranges[o].end = rs->ranges[i].end;
			o++;
		}
	}
	assert(o <= rs->nr);
	rs->nr = o;
 
	range_set_check_invariants(rs);
}
 
/*
 * Union of range sets (i.e., sets of line numbers).  Used to merge
 * them when searches meet at a common ancestor.
 *
 * This is also where the ranges are consolidated into canonical form:
 * overlapping and adjacent ranges are merged, and empty ranges are
 * removed.
 */
static void range_set_union(struct range_set *out,
			     struct range_set *a, struct range_set *b)
{
	unsigned int i = 0, j = 0;
	struct range *ra = a->ranges;
	struct range *rb = b->ranges;
	/* cannot make an alias of out->ranges: it may change during grow */
 
	assert(out->nr == 0);
	while (i < a->nr || j < b->nr) {
		struct range *new_range;
		if (i < a->nr && j < b->nr) {
			if (ra[i].start < rb[j].start)
				new_range = &ra[i++];
			else if (ra[i].start > rb[j].start)
				new_range = &rb[j++];
			else if (ra[i].end < rb[j].end)
				new_range = &ra[i++];
			else
				new_range = &rb[j++];
		} else if (i < a->nr)      /* b exhausted */
			new_range = &ra[i++];
		else                       /* a exhausted */
			new_range = &rb[j++];
		if (new_range->start == new_range->end)
			; /* empty range */
		else if (!out->nr || out->ranges[out->nr-1].end < new_range->start) {
			range_set_grow(out, 1);
			out->ranges[out->nr].start = new_range->start;
			out->ranges[out->nr].end = new_range->end;
			out->nr++;
		} else if (out->ranges[out->nr-1].end < new_range->end) {
			out->ranges[out->nr-1].end = new_range->end;
		}
	}
}
 
/*
 * Difference of range sets (out = a \ b).  Pass the "interesting"
 * ranges as 'a' and the target side of the diff as 'b': it removes
 * the ranges for which the commit is responsible.
 */
static void range_set_difference(struct range_set *out,
				  struct range_set *a, struct range_set *b)
{
	unsigned int i, j =  0;
	for (i = 0; i < a->nr; i++) {
		long start = a->ranges[i].start;
		long end = a->ranges[i].end;
		while (start < end) {
			while (j < b->nr && start >= b->ranges[j].end)
				/*
				 * a:         |-------
				 * b: ------|
				 */
				j++;
			if (j >= b->nr || end < b->ranges[j].start) {
				/*
				 * b exhausted, or
				 * a:  ----|
				 * b:         |----
				 */
				range_set_append(out, start, end);
				break;
			}
			if (start >= b->ranges[j].start) {
				/*
				 * a:     |--????
				 * b: |------|
				 */
				start = b->ranges[j].end;
			} else if (end > b->ranges[j].start) {
				/*
				 * a: |-----|
				 * b:    |--?????
				 */
				if (start < b->ranges[j].start)
					range_set_append(out, start, b->ranges[j].start);
				start = b->ranges[j].end;
			}
		}
	}
}
 
static void diff_ranges_init(struct diff_ranges *diff)
{
	range_set_init(&diff->parent, 0);
	range_set_init(&diff->target, 0);
}
 
static void diff_ranges_release(struct diff_ranges *diff)
{
	range_set_release(&diff->parent);
	range_set_release(&diff->target);
}
 
static void line_log_data_init(struct line_log_data *r)
{
	memset(r, 0, sizeof(struct line_log_data));
	range_set_init(&r->ranges, 0);
}
 
static void line_log_data_clear(struct line_log_data *r)
{
	range_set_release(&r->ranges);
	if (r->pair)
		diff_free_filepair(r->pair);
}
 
static void free_line_log_data(struct line_log_data *r)
{
	while (r) {
		struct line_log_data *next = r->next;
		line_log_data_clear(r);
		free(r);
		r = next;
	}
}
 
static struct line_log_data *
search_line_log_data(struct line_log_data *list, const char *path,
		     struct line_log_data **insertion_point)
{
	struct line_log_data *p = list;
	if (insertion_point)
		*insertion_point = NULL;
	while (p) {
		int cmp = strcmp(p->path, path);
		if (!cmp)
			return p;
		if (insertion_point && cmp < 0)
			*insertion_point = p;
		p = p->next;
	}
	return NULL;
}
 
/*
 * Note: takes ownership of 'path', which happens to be what the only
 * caller needs.
 */
static void line_log_data_insert(struct line_log_data **list,
				 char *path,
				 long begin, long end)
{
	struct line_log_data *ip;
	struct line_log_data *p = search_line_log_data(*list, path, &ip);
 
	if (p) {
		range_set_append_unsafe(&p->ranges, begin, end);
		free(path);
		return;
	}
 
	p = xcalloc(1, sizeof(struct line_log_data));
	p->path = path;
	range_set_append(&p->ranges, begin, end);
	if (ip) {
		p->next = ip->next;
		ip->next = p;
	} else {
		p->next = *list;
		*list = p;
	}
}
 
struct collect_diff_cbdata {
	struct diff_ranges *diff;
};
 
static int collect_diff_cb(long start_a, long count_a,
			   long start_b, long count_b,
			   void *data)
{
	struct collect_diff_cbdata *d = data;
 
	if (count_a >= 0)
		range_set_append(&d->diff->parent, start_a, start_a + count_a);
	if (count_b >= 0)
		range_set_append(&d->diff->target, start_b, start_b + count_b);
 
	return 0;
}
 
static int collect_diff(mmfile_t *parent, mmfile_t *target, struct diff_ranges *out)
{
	struct collect_diff_cbdata cbdata = {NULL};
	xpparam_t xpp;
	xdemitconf_t xecfg;
	xdemitcb_t ecb;
 
	memset(&xpp, 0, sizeof(xpp));
	memset(&xecfg, 0, sizeof(xecfg));
	xecfg.ctxlen = xecfg.interhunkctxlen = 0;
 
	cbdata.diff = out;
	xecfg.hunk_func = collect_diff_cb;
	memset(&ecb, 0, sizeof(ecb));
	ecb.priv = &cbdata;
	return xdi_diff(parent, target, &xpp, &xecfg, &ecb);
}
 
/*
 * These are handy for debugging.  Removing them with #if 0 silences
 * the "unused function" warning.
 */
#if 0
static void dump_range_set(struct range_set *rs, const char *desc)
{
	int i;
	printf("range set %s (%d items):\n", desc, rs->nr);
	for (i = 0; i < rs->nr; i++)
		printf("\t[%ld,%ld]\n", rs->ranges[i].start, rs->ranges[i].end);
}
 
static void dump_line_log_data(struct line_log_data *r)
{
	char buf[4096];
	while (r) {
		snprintf(buf, 4096, "file %s\n", r->path);
		dump_range_set(&r->ranges, buf);
		r = r->next;
	}
}
 
static void dump_diff_ranges(struct diff_ranges *diff, const char *desc)
{
	int i;
	assert(diff->parent.nr == diff->target.nr);
	printf("diff ranges %s (%d items):\n", desc, diff->parent.nr);
	printf("\tparent\ttarget\n");
	for (i = 0; i < diff->parent.nr; i++) {
		printf("\t[%ld,%ld]\t[%ld,%ld]\n",
		       diff->parent.ranges[i].start,
		       diff->parent.ranges[i].end,
		       diff->target.ranges[i].start,
		       diff->target.ranges[i].end);
	}
}
#endif
 
 
static int ranges_overlap(struct range *a, struct range *b)
{
	return !(a->end <= b->start || b->end <= a->start);
}
 
/*
 * Given a diff and the set of interesting ranges, determine all hunks
 * of the diff which touch (overlap) at least one of the interesting
 * ranges in the target.
 */
static void diff_ranges_filter_touched(struct diff_ranges *out,
				       struct diff_ranges *diff,
				       struct range_set *rs)
{
	unsigned int i, j = 0;
 
	assert(out->target.nr == 0);
 
	for (i = 0; i < diff->target.nr; i++) {
		while (diff->target.ranges[i].start > rs->ranges[j].end) {
			j++;
			if (j == rs->nr)
				return;
		}
		if (ranges_overlap(&diff->target.ranges[i], &rs->ranges[j])) {
			range_set_append(&out->parent,
					 diff->parent.ranges[i].start,
					 diff->parent.ranges[i].end);
			range_set_append(&out->target,
					 diff->target.ranges[i].start,
					 diff->target.ranges[i].end);
		}
	}
}
 
/*
 * Adjust the line counts in 'rs' to account for the lines
 * added/removed in the diff.
 */
static void range_set_shift_diff(struct range_set *out,
				 struct range_set *rs,
				 struct diff_ranges *diff)
{
	unsigned int i, j = 0;
	long offset = 0;
	struct range *src = rs->ranges;
	struct range *target = diff->target.ranges;
	struct range *parent = diff->parent.ranges;
 
	for (i = 0; i < rs->nr; i++) {
		while (j < diff->target.nr && src[i].start >= target[j].start) {
			offset += (parent[j].end-parent[j].start)
				- (target[j].end-target[j].start);
			j++;
		}
		range_set_append(out, src[i].start+offset, src[i].end+offset);
	}
}
 
/*
 * Given a diff and the set of interesting ranges, map the ranges
 * across the diff.  That is: observe that the target commit takes
 * blame for all the + (target-side) ranges.  So for every pair of
 * ranges in the diff that was touched, we remove the latter and add
 * its parent side.
 */
static void range_set_map_across_diff(struct range_set *out,
				      struct range_set *rs,
				      struct diff_ranges *diff,
				      struct diff_ranges **touched_out)
{
	struct diff_ranges *touched = xmalloc(sizeof(*touched));
	struct range_set tmp1 = RANGE_SET_INIT;
	struct range_set tmp2 = RANGE_SET_INIT;
 
	diff_ranges_init(touched);
	diff_ranges_filter_touched(touched, diff, rs);
	range_set_difference(&tmp1, rs, &touched->target);
	range_set_shift_diff(&tmp2, &tmp1, diff);
	range_set_union(out, &tmp2, &touched->parent);
	range_set_release(&tmp1);
	range_set_release(&tmp2);
 
	*touched_out = touched;
}
 
static struct commit *check_single_commit(struct rev_info *revs)
{
	struct object *commit = NULL;
	int found = -1;
	int i;
 
	for (i = 0; i < revs->pending.nr; i++) {
		struct object *obj = revs->pending.objects[i].item;
		if (obj->flags & UNINTERESTING)
			continue;
		obj = deref_tag(revs->repo, obj, NULL, 0);
		if (obj->type != OBJ_COMMIT)
			die("Non commit %s?", revs->pending.objects[i].name);
		if (commit)
			die("More than one commit to dig from: %s and %s?",
			    revs->pending.objects[i].name,
			    revs->pending.objects[found].name);
		commit = obj;
		found = i;
	}
 
	if (!commit)
		die("No commit specified?");
 
	return (struct commit *) commit;
}
 
static void fill_blob_sha1(struct commit *commit, struct diff_filespec *spec)
{
	unsigned mode;
	struct object_id oid;
 
	if (get_tree_entry(&commit->object.oid, spec->path, &oid, &mode))
		die("There is no path %s in the commit", spec->path);
	fill_filespec(spec, &oid, 1, mode);
 
	return;
}
 
static void fill_line_ends(struct repository *r,
			   struct diff_filespec *spec,
			   long *lines,
			   unsigned long **line_ends)
{
	int num = 0, size = 50;
	long cur = 0;
	unsigned long *ends = NULL;
	char *data = NULL;
 
	if (diff_populate_filespec(r, spec, 0))
		die("Cannot read blob %s", oid_to_hex(&spec->oid));
 
	ALLOC_ARRAY(ends, size);
	ends[cur++] = 0;
	data = spec->data;
	while (num < spec->size) {
		if (data[num] == '\n' || num == spec->size - 1) {
			ALLOC_GROW(ends, (cur + 1), size);
			ends[cur++] = num;
		}
		num++;
	}
 
	/* shrink the array to fit the elements */
	REALLOC_ARRAY(ends, cur);
	*lines = cur-1;
	*line_ends = ends;
}
 
struct nth_line_cb {
	struct diff_filespec *spec;
	long lines;
	unsigned long *line_ends;
};
 
static const char *nth_line(void *data, long line)
{
	struct nth_line_cb *d = data;
	assert(d && line <= d->lines);
	assert(d->spec && d->spec->data);
 
	if (line == 0)
		return (char *)d->spec->data;
	else
		return (char *)d->spec->data + d->line_ends[line] + 1;
}
 
static struct line_log_data *
parse_lines(struct repository *r, struct commit *commit,
	    const char *prefix, struct string_list *args)
{
	long lines = 0;
	unsigned long *ends = NULL;
	struct nth_line_cb cb_data;
	struct string_list_item *item;
	struct line_log_data *ranges = NULL;
	struct line_log_data *p;
 
	for_each_string_list_item(item, args) {
		const char *name_part, *range_part;
		char *full_name;
		struct diff_filespec *spec;
		long begin = 0, end = 0;
		long anchor;
 
		name_part = skip_range_arg(item->string, r->index);
		if (!name_part || *name_part != ':' || !name_part[1])
			die("-L argument not 'start,end:file' or ':funcname:file': %s",
			    item->string);
		range_part = xstrndup(item->string, name_part - item->string);
		name_part++;
 
		full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
					name_part);
 
		spec = alloc_filespec(full_name);
		fill_blob_sha1(commit, spec);
		fill_line_ends(r, spec, &lines, &ends);
		cb_data.spec = spec;
		cb_data.lines = lines;
		cb_data.line_ends = ends;
 
		p = search_line_log_data(ranges, full_name, NULL);
		if (p && p->ranges.nr)
			anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
		else
			anchor = 1;
 
		if (parse_range_arg(range_part, nth_line, &cb_data,
				    lines, anchor, &begin, &end,
				    full_name, r->index))
			die("malformed -L argument '%s'", range_part);
		if ((!lines && (begin || end)) || lines < begin)
			die("file %s has only %lu lines", name_part, lines);
		if (begin < 1)
			begin = 1;
		if (end < 1 || lines < end)
			end = lines;
		begin--;
		line_log_data_insert(&ranges, full_name, begin, end);
 
		free_filespec(spec);
		FREE_AND_NULL(ends);
	}
 
	for (p = ranges; p; p = p->next)
		sort_and_merge_range_set(&p->ranges);
 
	return ranges;
}
 
static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
{
	struct line_log_data *ret = xmalloc(sizeof(*ret));
 
	assert(r);
	line_log_data_init(ret);
	range_set_copy(&ret->ranges, &r->ranges);
 
	ret->path = xstrdup(r->path);
 
	return ret;
}
 
static struct line_log_data *
line_log_data_copy(struct line_log_data *r)
{
	struct line_log_data *ret = NULL;
	struct line_log_data *tmp = NULL, *prev = NULL;
 
	assert(r);
	ret = tmp = prev = line_log_data_copy_one(r);
	r = r->next;
	while (r) {
		tmp = line_log_data_copy_one(r);
		prev->next = tmp;
		prev = tmp;
		r = r->next;
	}
 
	return ret;
}
 
/* merge two range sets across files */
static struct line_log_data *line_log_data_merge(struct line_log_data *a,
						 struct line_log_data *b)
{
	struct line_log_data *head = NULL, **pp = &head;
 
	while (a || b) {
		struct line_log_data *src;
		struct line_log_data *src2 = NULL;
		struct line_log_data *d;
		int cmp;
		if (!a)
			cmp = 1;
		else if (!b)
			cmp = -1;
		else
			cmp = strcmp(a->path, b->path);
		if (cmp < 0) {
			src = a;
			a = a->next;
		} else if (cmp == 0) {
			src = a;
			a = a->next;
			src2 = b;
			b = b->next;
		} else {
			src = b;
			b = b->next;
		}
		d = xmalloc(sizeof(struct line_log_data));
		line_log_data_init(d);
		d->path = xstrdup(src->path);
		*pp = d;
		pp = &d->next;
		if (src2)
			range_set_union(&d->ranges, &src->ranges, &src2->ranges);
		else
			range_set_copy(&d->ranges, &src->ranges);
	}
 
	return head;
}
 
static void add_line_range(struct rev_info *revs, struct commit *commit,
			   struct line_log_data *range)
{
	struct line_log_data *old_line = NULL;
	struct line_log_data *new_line = NULL;
 
	old_line = lookup_decoration(&revs->line_log_data, &commit->object);
	if (old_line && range) {
		new_line = line_log_data_merge(old_line, range);
		free_line_log_data(old_line);
	} else if (range)
		new_line = line_log_data_copy(range);
 
	if (new_line)
		add_decoration(&revs->line_log_data, &commit->object, new_line);
}
 
static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
{
	struct line_log_data *r;
	r = lookup_decoration(&revs->line_log_data, &commit->object);
	if (!r)
		return;
	free_line_log_data(r);
	add_decoration(&revs->line_log_data, &commit->object, NULL);
}
 
static struct line_log_data *lookup_line_range(struct rev_info *revs,
					       struct commit *commit)
{
	struct line_log_data *ret = NULL;
	struct line_log_data *d;
 
	ret = lookup_decoration(&revs->line_log_data, &commit->object);
 
	for (d = ret; d; d = d->next)
		range_set_check_invariants(&d->ranges);
 
	return ret;
}
 
void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
{
	struct commit *commit = NULL;
	struct line_log_data *range;
 
	commit = check_single_commit(rev);
	range = parse_lines(rev->diffopt.repo, commit, prefix, args);
	add_line_range(rev, commit, range);
 
	if (!rev->diffopt.detect_rename) {
		struct line_log_data *r;
		struct argv_array array = ARGV_ARRAY_INIT;
		const char **paths;
 
		for (r = range; r; r = r->next)
			argv_array_push(&array, r->path);
		paths = argv_array_detach(&array);
 
		parse_pathspec(&rev->diffopt.pathspec, 0,
			       PATHSPEC_PREFER_FULL, "", paths);
		/* strings are now owned by pathspec */
		free(paths);
	}
}
 
static void move_diff_queue(struct diff_queue_struct *dst,
			    struct diff_queue_struct *src)
{
	assert(src != dst);
	memcpy(dst, src, sizeof(struct diff_queue_struct));
	DIFF_QUEUE_CLEAR(src);
}
 
static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
{
	int i;
	struct diff_queue_struct outq;
	DIFF_QUEUE_CLEAR(&outq);
 
	for (i = 0; i < diff_queued_diff.nr; i++) {
		struct diff_filepair *p = diff_queued_diff.queue[i];
		struct line_log_data *rg = NULL;
 
		if (!DIFF_FILE_VALID(p->two)) {
			if (keep_deletions)
				diff_q(&outq, p);
			else
				diff_free_filepair(p);
			continue;
		}
		for (rg = range; rg; rg = rg->next) {
			if (!strcmp(rg->path, p->two->path))
				break;
		}
		if (rg)
			diff_q(&outq, p);
		else
			diff_free_filepair(p);
	}
	free(diff_queued_diff.queue);
	diff_queued_diff = outq;
}
 
static inline int diff_might_be_rename(void)
{
	int i;
	for (i = 0; i < diff_queued_diff.nr; i++)
		if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
			/* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
			/* 	diff_queued_diff.queue[i]->two->path); */
			return 1;
		}
	return 0;
}
 
static void queue_diffs(struct line_log_data *range,
			struct diff_options *opt,
			struct diff_queue_struct *queue,
			struct commit *commit, struct commit *parent)
{
	assert(commit);
 
	DIFF_QUEUE_CLEAR(&diff_queued_diff);
	diff_tree_oid(parent ? get_commit_tree_oid(parent) : NULL,
		      get_commit_tree_oid(commit), "", opt);
	if (opt->detect_rename) {
		filter_diffs_for_paths(range, 1);
		if (diff_might_be_rename())
			diffcore_std(opt);
		filter_diffs_for_paths(range, 0);
	}
	move_diff_queue(queue, &diff_queued_diff);
}
 
static char *get_nth_line(long line, unsigned long *ends, void *data)
{
	if (line == 0)
		return (char *)data;
	else
		return (char *)data + ends[line] + 1;
}
 
static void print_line(const char *prefix, char first,
		       long line, unsigned long *ends, void *data,
		       const char *color, const char *reset, FILE *file)
{
	char *begin = get_nth_line(line, ends, data);
	char *end = get_nth_line(line+1, ends, data);
	int had_nl = 0;
 
	if (end > begin && end[-1] == '\n') {
		end--;
		had_nl = 1;
	}
 
	fputs(prefix, file);
	fputs(color, file);
	putc(first, file);
	fwrite(begin, 1, end-begin, file);
	fputs(reset, file);
	putc('\n', file);
	if (!had_nl)
		fputs("\\ No newline at end of file\n", file);
}
 
static char *output_prefix(struct diff_options *opt)
{
	char *prefix = "";
 
	if (opt->output_prefix) {
		struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
		prefix = sb->buf;
	}
 
	return prefix;
}
 
static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
{
	unsigned int i, j = 0;
	long p_lines, t_lines;
	unsigned long *p_ends = NULL, *t_ends = NULL;
	struct diff_filepair *pair = range->pair;
	struct diff_ranges *diff = &range->diff;
 
	struct diff_options *opt = &rev->diffopt;
	char *prefix = output_prefix(opt);
	const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
	const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
	const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
	const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
	const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
	const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
 
	if (!pair || !diff)
		return;
 
	if (pair->one->oid_valid)
		fill_line_ends(rev->diffopt.repo, pair->one, &p_lines, &p_ends);
	fill_line_ends(rev->diffopt.repo, pair->two, &t_lines, &t_ends);
 
	fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
	fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
	       pair->one->oid_valid ? "a/" : "",
	       pair->one->oid_valid ? pair->one->path : "/dev/null",
	       c_reset);
	fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
	for (i = 0; i < range->ranges.nr; i++) {
		long p_start, p_end;
		long t_start = range->ranges.ranges[i].start;
		long t_end = range->ranges.ranges[i].end;
		long t_cur = t_start;
		unsigned int j_last;
 
		while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
			j++;
		if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
			continue;
 
		/* Scan ahead to determine the last diff that falls in this range */
		j_last = j;
		while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
			j_last++;
		if (j_last > j)
			j_last--;
 
		/*
		 * Compute parent hunk headers: we know that the diff
		 * has the correct line numbers (but not all hunks).
		 * So it suffices to shift the start/end according to
		 * the line numbers of the first/last hunk(s) that
		 * fall in this range.
		 */
		if (t_start < diff->target.ranges[j].start)
			p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
		else
			p_start = diff->parent.ranges[j].start;
		if (t_end > diff->target.ranges[j_last].end)
			p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
		else
			p_end = diff->parent.ranges[j_last].end;
 
		if (!p_start && !p_end) {
			p_start = -1;
			p_end = -1;
		}
 
		/* Now output a diff hunk for this range */
		fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
		       prefix, c_frag,
		       p_start+1, p_end-p_start, t_start+1, t_end-t_start,
		       c_reset);
		while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
			int k;
			for (; t_cur < diff->target.ranges[j].start; t_cur++)
				print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
					   c_context, c_reset, opt->file);
			for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
				print_line(prefix, '-', k, p_ends, pair->one->data,
					   c_old, c_reset, opt->file);
			for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
				print_line(prefix, '+', t_cur, t_ends, pair->two->data,
					   c_new, c_reset, opt->file);
			j++;
		}
		for (; t_cur < t_end; t_cur++)
			print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
				   c_context, c_reset, opt->file);
	}
 
	free(p_ends);
	free(t_ends);
}
 
/*
 * NEEDSWORK: manually building a diff here is not the Right
 * Thing(tm).  log -L should be built into the diff pipeline.
 */
static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
{
	fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
	while (range) {
		dump_diff_hacky_one(rev, range);
		range = range->next;
	}
}
 
/*
 * Unlike most other functions, this destructively operates on
 * 'range'.
 */
static int process_diff_filepair(struct rev_info *rev,
				 struct diff_filepair *pair,
				 struct line_log_data *range,
				 struct diff_ranges **diff_out)
{
	struct line_log_data *rg = range;
	struct range_set tmp;
	struct diff_ranges diff;
	mmfile_t file_parent, file_target;
 
	assert(pair->two->path);
	while (rg) {
		assert(rg->path);
		if (!strcmp(rg->path, pair->two->path))
			break;
		rg = rg->next;
	}
 
	if (!rg)
		return 0;
	if (rg->ranges.nr == 0)
		return 0;
 
	assert(pair->two->oid_valid);
	diff_populate_filespec(rev->diffopt.repo, pair->two, 0);
	file_target.ptr = pair->two->data;
	file_target.size = pair->two->size;
 
	if (pair->one->oid_valid) {
		diff_populate_filespec(rev->diffopt.repo, pair->one, 0);
		file_parent.ptr = pair->one->data;
		file_parent.size = pair->one->size;
	} else {
		file_parent.ptr = "";
		file_parent.size = 0;
	}
 
	diff_ranges_init(&diff);
	if (collect_diff(&file_parent, &file_target, &diff))
		die("unable to generate diff for %s", pair->one->path);
 
	/* NEEDSWORK should apply some heuristics to prevent mismatches */
	free(rg->path);
	rg->path = xstrdup(pair->one->path);
 
	range_set_init(&tmp, 0);
	range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
	range_set_release(&rg->ranges);
	range_set_move(&rg->ranges, &tmp);
 
	diff_ranges_release(&diff);
 
	return ((*diff_out)->parent.nr > 0);
}
 
static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
{
	struct diff_filepair *new_filepair = xmalloc(sizeof(struct diff_filepair));
	new_filepair->one = pair->one;
	new_filepair->two = pair->two;
	new_filepair->one->count++;
	new_filepair->two->count++;
	return new_filepair;
}
 
static void free_diffqueues(int n, struct diff_queue_struct *dq)
{
	int i, j;
	for (i = 0; i < n; i++)
		for (j = 0; j < dq[i].nr; j++)
			diff_free_filepair(dq[i].queue[j]);
	free(dq);
}
 
static int process_all_files(struct line_log_data **range_out,
			     struct rev_info *rev,
			     struct diff_queue_struct *queue,
			     struct line_log_data *range)
{
	int i, changed = 0;
 
	*range_out = line_log_data_copy(range);
 
	for (i = 0; i < queue->nr; i++) {
		struct diff_ranges *pairdiff = NULL;
		struct diff_filepair *pair = queue->queue[i];
		if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
			/*
			 * Store away the diff for later output.  We
			 * tuck it in the ranges we got as _input_,
			 * since that's the commit that caused the
			 * diff.
			 *
			 * NEEDSWORK not enough when we get around to
			 * doing something interesting with merges;
			 * currently each invocation on a merge parent
			 * trashes the previous one's diff.
			 *
			 * NEEDSWORK tramples over data structures not owned here
			 */
			struct line_log_data *rg = range;
			changed++;
			while (rg && strcmp(rg->path, pair->two->path))
				rg = rg->next;
			assert(rg);
			rg->pair = diff_filepair_dup(queue->queue[i]);
			memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
		}
		free(pairdiff);
	}
 
	return changed;
}
 
int line_log_print(struct rev_info *rev, struct commit *commit)
{
	struct line_log_data *range = lookup_line_range(rev, commit);
 
	show_log(rev);
	dump_diff_hacky(rev, range);
	return 1;
}
 
static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
					  struct line_log_data *range)
{
	struct commit *parent = NULL;
	struct diff_queue_struct queue;
	struct line_log_data *parent_range;
	int changed;
 
	if (commit->parents)
		parent = commit->parents->item;
 
	queue_diffs(range, &rev->diffopt, &queue, commit, parent);
	changed = process_all_files(&parent_range, rev, &queue, range);
	if (parent)
		add_line_range(rev, parent, parent_range);
	free_line_log_data(parent_range);
	return changed;
}
 
static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
				       struct line_log_data *range)
{
	struct diff_queue_struct *diffqueues;
	struct line_log_data **cand;
	struct commit **parents;
	struct commit_list *p;
	int i;
	int nparents = commit_list_count(commit->parents);
 
	if (nparents > 1 && rev->first_parent_only)
		nparents = 1;
 
	ALLOC_ARRAY(diffqueues, nparents);
	ALLOC_ARRAY(cand, nparents);
	ALLOC_ARRAY(parents, nparents);
 
	p = commit->parents;
	for (i = 0; i < nparents; i++) {
		parents[i] = p->item;
		p = p->next;
		queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
	}
 
	for (i = 0; i < nparents; i++) {
		int changed;
		cand[i] = NULL;
		changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
		if (!changed) {
			/*
			 * This parent can take all the blame, so we
			 * don't follow any other path in history
			 */
			add_line_range(rev, parents[i], cand[i]);
			clear_commit_line_range(rev, commit);
			commit_list_append(parents[i], &commit->parents);
			free(parents);
			free(cand);
			free_diffqueues(nparents, diffqueues);
			/* NEEDSWORK leaking like a sieve */
			return 0;
		}
	}
 
	/*
	 * No single parent took the blame.  We add the candidates
	 * from the above loop to the parents.
	 */
	for (i = 0; i < nparents; i++) {
		add_line_range(rev, parents[i], cand[i]);
	}
 
	clear_commit_line_range(rev, commit);
	free(parents);
	free(cand);
	free_diffqueues(nparents, diffqueues);
	return 1;
 
	/* NEEDSWORK evil merge detection stuff */
	/* NEEDSWORK leaking like a sieve */
}
 
static int process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
{
	struct line_log_data *range = lookup_line_range(rev, commit);
	int changed = 0;
 
	if (range) {
		if (!commit->parents || !commit->parents->next)
			changed = process_ranges_ordinary_commit(rev, commit, range);
		else
			changed = process_ranges_merge_commit(rev, commit, range);
	}
 
	if (!changed)
		commit->object.flags |= TREESAME;
 
	return changed;
}
 
static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
{
	for (;;) {
		struct commit *p = *pp;
		if (p->parents && p->parents->next)
			return rewrite_one_ok;
		if (p->object.flags & UNINTERESTING)
			return rewrite_one_ok;
		if (!(p->object.flags & TREESAME))
			return rewrite_one_ok;
		if (!p->parents)
			return rewrite_one_noparents;
		*pp = p->parents->item;
	}
}
 
int line_log_filter(struct rev_info *rev)
{
	struct commit *commit;
	struct commit_list *list = rev->commits;
	struct commit_list *out = NULL, **pp = &out;
 
	while (list) {
		struct commit_list *to_free = NULL;
		commit = list->item;
		if (process_ranges_arbitrary_commit(rev, commit)) {
			*pp = list;
			pp = &list->next;
		} else
			to_free = list;
		list = list->next;
		free(to_free);
	}
	*pp = NULL;
 
	for (list = out; list; list = list->next)
		rewrite_parents(rev, list->item, line_log_rewrite_one);
 
	rev->commits = out;
 
	return 0;
}