aboutsummaryrefslogtreecommitdiff
path: root/revision.c
blob: 713f27e3ce2b8b3491e20720f7dba2c641b4422a (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
#include "cache.h"
#include "tag.h"
#include "blob.h"
#include "tree.h"
#include "commit.h"
#include "diff.h"
#include "refs.h"
#include "revision.h"

static char *path_name(struct name_path *path, const char *name)
{
	struct name_path *p;
	char *n, *m;
	int nlen = strlen(name);
	int len = nlen + 1;

	for (p = path; p; p = p->up) {
		if (p->elem_len)
			len += p->elem_len + 1;
	}
	n = xmalloc(len);
	m = n + len - (nlen + 1);
	strcpy(m, name);
	for (p = path; p; p = p->up) {
		if (p->elem_len) {
			m -= p->elem_len + 1;
			memcpy(m, p->elem, p->elem_len);
			m[p->elem_len] = '/';
		}
	}
	return n;
}

struct object_list **add_object(struct object *obj,
				       struct object_list **p,
				       struct name_path *path,
				       const char *name)
{
	struct object_list *entry = xmalloc(sizeof(*entry));
	entry->item = obj;
	entry->next = *p;
	entry->name = path_name(path, name);
	*p = entry;
	return &entry->next;
}

static void mark_blob_uninteresting(struct blob *blob)
{
	if (blob->object.flags & UNINTERESTING)
		return;
	blob->object.flags |= UNINTERESTING;
}

void mark_tree_uninteresting(struct tree *tree)
{
	struct object *obj = &tree->object;
	struct tree_entry_list *entry;

	if (obj->flags & UNINTERESTING)
		return;
	obj->flags |= UNINTERESTING;
	if (!has_sha1_file(obj->sha1))
		return;
	if (parse_tree(tree) < 0)
		die("bad tree %s", sha1_to_hex(obj->sha1));
	entry = tree->entries;
	tree->entries = NULL;
	while (entry) {
		struct tree_entry_list *next = entry->next;
		if (entry->directory)
			mark_tree_uninteresting(entry->item.tree);
		else
			mark_blob_uninteresting(entry->item.blob);
		free(entry);
		entry = next;
	}
}

void mark_parents_uninteresting(struct commit *commit)
{
	struct commit_list *parents = commit->parents;

	while (parents) {
		struct commit *commit = parents->item;
		if (!(commit->object.flags & UNINTERESTING)) {
			commit->object.flags |= UNINTERESTING;

			/*
			 * Normally we haven't parsed the parent
			 * yet, so we won't have a parent of a parent
			 * here. However, it may turn out that we've
			 * reached this commit some other way (where it
			 * wasn't uninteresting), in which case we need
			 * to mark its parents recursively too..
			 */
			if (commit->parents)
				mark_parents_uninteresting(commit);
		}

		/*
		 * A missing commit is ok iff its parent is marked
		 * uninteresting.
		 *
		 * We just mark such a thing parsed, so that when
		 * it is popped next time around, we won't be trying
		 * to parse it and get an error.
		 */
		if (!has_sha1_file(commit->object.sha1))
			commit->object.parsed = 1;
		parents = parents->next;
	}
}

static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
{
	add_object(obj, &revs->pending_objects, NULL, name);
}

static struct commit *get_commit_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
{
	struct object *object;

	object = parse_object(sha1);
	if (!object)
		die("bad object %s", name);

	/*
	 * Tag object? Look what it points to..
	 */
	while (object->type == tag_type) {
		struct tag *tag = (struct tag *) object;
		object->flags |= flags;
		if (revs->tag_objects && !(object->flags & UNINTERESTING))
			add_pending_object(revs, object, tag->tag);
		object = parse_object(tag->tagged->sha1);
		if (!object)
			die("bad object %s", sha1_to_hex(tag->tagged->sha1));
	}

	/*
	 * Commit object? Just return it, we'll do all the complex
	 * reachability crud.
	 */
	if (object->type == commit_type) {
		struct commit *commit = (struct commit *)object;
		object->flags |= flags;
		if (parse_commit(commit) < 0)
			die("unable to parse commit %s", name);
		if (flags & UNINTERESTING) {
			mark_parents_uninteresting(commit);
			revs->limited = 1;
		}
		return commit;
	}

	/*
	 * Tree object? Either mark it uniniteresting, or add it
	 * to the list of objects to look at later..
	 */
	if (object->type == tree_type) {
		struct tree *tree = (struct tree *)object;
		if (!revs->tree_objects)
			return NULL;
		if (flags & UNINTERESTING) {
			mark_tree_uninteresting(tree);
			return NULL;
		}
		add_pending_object(revs, object, "");
		return NULL;
	}

	/*
	 * Blob object? You know the drill by now..
	 */
	if (object->type == blob_type) {
		struct blob *blob = (struct blob *)object;
		if (!revs->blob_objects)
			return NULL;
		if (flags & UNINTERESTING) {
			mark_blob_uninteresting(blob);
			return NULL;
		}
		add_pending_object(revs, object, "");
		return NULL;
	}
	die("%s is unknown object", name);
}

static int everybody_uninteresting(struct commit_list *orig)
{
	struct commit_list *list = orig;
	while (list) {
		struct commit *commit = list->item;
		list = list->next;
		if (commit->object.flags & UNINTERESTING)
			continue;
		return 0;
	}
	return 1;
}

#define TREE_SAME	0
#define TREE_NEW	1
#define TREE_DIFFERENT	2
static int tree_difference = TREE_SAME;

static void file_add_remove(struct diff_options *options,
		    int addremove, unsigned mode,
		    const unsigned char *sha1,
		    const char *base, const char *path)
{
	int diff = TREE_DIFFERENT;

	/*
	 * Is it an add of a new file? It means that
	 * the old tree didn't have it at all, so we
	 * will turn "TREE_SAME" -> "TREE_NEW", but
	 * leave any "TREE_DIFFERENT" alone (and if
	 * it already was "TREE_NEW", we'll keep it
	 * "TREE_NEW" of course).
	 */
	if (addremove == '+') {
		diff = tree_difference;
		if (diff != TREE_SAME)
			return;
		diff = TREE_NEW;
	}
	tree_difference = diff;
}

static void file_change(struct diff_options *options,
		 unsigned old_mode, unsigned new_mode,
		 const unsigned char *old_sha1,
		 const unsigned char *new_sha1,
		 const char *base, const char *path)
{
	tree_difference = TREE_DIFFERENT;
}

static struct diff_options diff_opt = {
	.recursive = 1,
	.add_remove = file_add_remove,
	.change = file_change,
};

static int compare_tree(struct tree *t1, struct tree *t2)
{
	if (!t1)
		return TREE_NEW;
	if (!t2)
		return TREE_DIFFERENT;
	tree_difference = TREE_SAME;
	if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
		return TREE_DIFFERENT;
	return tree_difference;
}

static int same_tree_as_empty(struct tree *t1)
{
	int retval;
	void *tree;
	struct tree_desc empty, real;

	if (!t1)
		return 0;

	tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
	if (!tree)
		return 0;
	real.buf = tree;

	empty.buf = "";
	empty.size = 0;

	tree_difference = 0;
	retval = diff_tree(&empty, &real, "", &diff_opt);
	free(tree);

	return retval >= 0 && !tree_difference;
}

static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
{
	struct commit_list **pp, *parent;

	if (!commit->tree)
		return;

	if (!commit->parents) {
		if (!same_tree_as_empty(commit->tree))
			commit->object.flags |= TREECHANGE;
		return;
	}

	pp = &commit->parents;
	while ((parent = *pp) != NULL) {
		struct commit *p = parent->item;

		if (p->object.flags & UNINTERESTING) {
			pp = &parent->next;
			continue;
		}

		parse_commit(p);
		switch (compare_tree(p->tree, commit->tree)) {
		case TREE_SAME:
			parent->next = NULL;
			commit->parents = parent;
			return;

		case TREE_NEW:
			if (revs->remove_empty_trees && same_tree_as_empty(p->tree)) {
				*pp = parent->next;
				continue;
			}
		/* fallthrough */
		case TREE_DIFFERENT:
			pp = &parent->next;
			continue;
		}
		die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
	}
	commit->object.flags |= TREECHANGE;
}

static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
{
	struct commit_list *parent = commit->parents;

	/*
	 * If the commit is uninteresting, don't try to
	 * prune parents - we want the maximal uninteresting
	 * set.
	 *
	 * Normally we haven't parsed the parent
	 * yet, so we won't have a parent of a parent
	 * here. However, it may turn out that we've
	 * reached this commit some other way (where it
	 * wasn't uninteresting), in which case we need
	 * to mark its parents recursively too..
	 */
	if (commit->object.flags & UNINTERESTING) {
		while (parent) {
			struct commit *p = parent->item;
			parent = parent->next;
			parse_commit(p);
			p->object.flags |= UNINTERESTING;
			if (p->parents)
				mark_parents_uninteresting(p);
			if (p->object.flags & SEEN)
				continue;
			p->object.flags |= SEEN;
			insert_by_date(p, list);
		}
		return;
	}

	/*
	 * Ok, the commit wasn't uninteresting. Try to
	 * simplify the commit history and find the parent
	 * that has no differences in the path set if one exists.
	 */
	if (revs->paths)
		try_to_simplify_commit(revs, commit);

	parent = commit->parents;
	while (parent) {
		struct commit *p = parent->item;

		parent = parent->next;

		parse_commit(p);
		if (p->object.flags & SEEN)
			continue;
		p->object.flags |= SEEN;
		insert_by_date(p, list);
	}
}

static void limit_list(struct rev_info *revs)
{
	struct commit_list *list = revs->commits;
	struct commit_list *newlist = NULL;
	struct commit_list **p = &newlist;

	if (revs->paths)
		diff_tree_setup_paths(revs->paths);

	while (list) {
		struct commit_list *entry = list;
		struct commit *commit = list->item;
		struct object *obj = &commit->object;

		list = list->next;
		free(entry);

		if (revs->max_age != -1 && (commit->date < revs->max_age))
			obj->flags |= UNINTERESTING;
		if (revs->unpacked && has_sha1_pack(obj->sha1))
			obj->flags |= UNINTERESTING;
		add_parents_to_list(revs, commit, &list);
		if (obj->flags & UNINTERESTING) {
			mark_parents_uninteresting(commit);
			if (everybody_uninteresting(list))
				break;
			continue;
		}
		if (revs->min_age != -1 && (commit->date > revs->min_age))
			continue;
		p = &commit_list_insert(commit, p)->next;
	}
	revs->commits = newlist;
}

static void add_one_commit(struct commit *commit, struct rev_info *revs)
{
	if (!commit || (commit->object.flags & SEEN))
		return;
	commit->object.flags |= SEEN;
	commit_list_insert(commit, &revs->commits);
}

static int all_flags;
static struct rev_info *all_revs;

static int handle_one_ref(const char *path, const unsigned char *sha1)
{
	struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
	add_one_commit(commit, all_revs);
	return 0;
}

static void handle_all(struct rev_info *revs, unsigned flags)
{
	all_revs = revs;
	all_flags = flags;
	for_each_ref(handle_one_ref);
}

/*
 * Parse revision information, filling in the "rev_info" structure,
 * and removing the used arguments from the argument list.
 *
 * Returns the number of arguments left that weren't recognized
 * (which are also moved to the head of the argument list)
 */
int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
{
	int i, flags, seen_dashdash;
	const char **unrecognized = argv + 1;
	int left = 1;

	memset(revs, 0, sizeof(*revs));
	revs->lifo = 1;
	revs->dense = 1;
	revs->prefix = setup_git_directory();
	revs->max_age = -1;
	revs->min_age = -1;
	revs->max_count = -1;

	/* First, search for "--" */
	seen_dashdash = 0;
	for (i = 1; i < argc; i++) {
		const char *arg = argv[i];
		if (strcmp(arg, "--"))
			continue;
		argv[i] = NULL;
		argc = i;
		revs->paths = get_pathspec(revs->prefix, argv + i + 1);
		seen_dashdash = 1;
		break;
	}

	flags = 0;
	for (i = 1; i < argc; i++) {
		struct commit *commit;
		const char *arg = argv[i];
		unsigned char sha1[20];
		char *dotdot;
		int local_flags;

		if (*arg == '-') {
			if (!strncmp(arg, "--max-count=", 12)) {
				revs->max_count = atoi(arg + 12);
				continue;
			}
			/* accept -<digit>, like traditilnal "head" */
			if ((*arg == '-') && isdigit(arg[1])) {
				revs->max_count = atoi(arg + 1);
				continue;
			}
			if (!strcmp(arg, "-n")) {
				if (argc <= i + 1)
					die("-n requires an argument");
				revs->max_count = atoi(argv[++i]);
				continue;
			}
			if (!strncmp(arg,"-n",2)) {
				revs->max_count = atoi(arg + 2);
				continue;
			}
			if (!strncmp(arg, "--max-age=", 10)) {
				revs->max_age = atoi(arg + 10);
				revs->limited = 1;
				continue;
			}
			if (!strncmp(arg, "--min-age=", 10)) {
				revs->min_age = atoi(arg + 10);
				revs->limited = 1;
				continue;
			}
			if (!strncmp(arg, "--since=", 8)) {
				revs->max_age = approxidate(arg + 8);
				revs->limited = 1;
				continue;
			}
			if (!strncmp(arg, "--after=", 8)) {
				revs->max_age = approxidate(arg + 8);
				revs->limited = 1;
				continue;
			}
			if (!strncmp(arg, "--before=", 9)) {
				revs->min_age = approxidate(arg + 9);
				revs->limited = 1;
				continue;
			}
			if (!strncmp(arg, "--until=", 8)) {
				revs->min_age = approxidate(arg + 8);
				revs->limited = 1;
				continue;
			}
			if (!strcmp(arg, "--all")) {
				handle_all(revs, flags);
				continue;
			}
			if (!strcmp(arg, "--not")) {
				flags ^= UNINTERESTING;
				continue;
			}
			if (!strcmp(arg, "--default")) {
				if (++i >= argc)
					die("bad --default argument");
				def = argv[i];
				continue;
			}
			if (!strcmp(arg, "--topo-order")) {
				revs->topo_order = 1;
				revs->limited = 1;
				continue;
			}
			if (!strcmp(arg, "--date-order")) {
				revs->lifo = 0;
				revs->topo_order = 1;
				revs->limited = 1;
				continue;
			}
			if (!strcmp(arg, "--dense")) {
				revs->dense = 1;
				continue;
			}
			if (!strcmp(arg, "--sparse")) {
				revs->dense = 0;
				continue;
			}
			if (!strcmp(arg, "--remove-empty")) {
				revs->remove_empty_trees = 1;
				continue;
			}
			if (!strncmp(arg, "--no-merges", 11)) {
				revs->no_merges = 1;
				continue;
			}
			if (!strcmp(arg, "--objects")) {
				revs->tag_objects = 1;
				revs->tree_objects = 1;
				revs->blob_objects = 1;
				continue;
			}
			if (!strcmp(arg, "--objects-edge")) {
				revs->tag_objects = 1;
				revs->tree_objects = 1;
				revs->blob_objects = 1;
				revs->edge_hint = 1;
				continue;
			}
			if (!strcmp(arg, "--unpacked")) {
				revs->unpacked = 1;
				revs->limited = 1;
				continue;
			}
			*unrecognized++ = arg;
			left++;
			continue;
		}
		dotdot = strstr(arg, "..");
		if (dotdot) {
			unsigned char from_sha1[20];
			char *next = dotdot + 2;
			*dotdot = 0;
			if (!*next)
				next = "HEAD";
			if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
				struct commit *exclude;
				struct commit *include;

				exclude = get_commit_reference(revs, arg, from_sha1, flags ^ UNINTERESTING);
				include = get_commit_reference(revs, next, sha1, flags);
				if (!exclude || !include)
					die("Invalid revision range %s..%s", arg, next);
				add_one_commit(exclude, revs);
				add_one_commit(include, revs);
				continue;
			}
			*dotdot = '.';
		}
		local_flags = 0;
		if (*arg == '^') {
			local_flags = UNINTERESTING;
			arg++;
		}
		if (get_sha1(arg, sha1) < 0) {
			struct stat st;
			int j;

			if (seen_dashdash || local_flags)
				die("bad revision '%s'", arg);

			/* If we didn't have a "--", all filenames must exist */
			for (j = i; j < argc; j++) {
				if (lstat(argv[j], &st) < 0)
					die("'%s': %s", arg, strerror(errno));
			}
			revs->paths = get_pathspec(revs->prefix, argv + i);
			break;
		}
		commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
		add_one_commit(commit, revs);
	}
	if (def && !revs->commits) {
		unsigned char sha1[20];
		struct commit *commit;
		if (get_sha1(def, sha1) < 0)
			die("bad default revision '%s'", def);
		commit = get_commit_reference(revs, def, sha1, 0);
		add_one_commit(commit, revs);
	}
	if (revs->paths)
		revs->limited = 1;
	return left;
}

void prepare_revision_walk(struct rev_info *revs)
{
	sort_by_date(&revs->commits);
	if (revs->limited)
		limit_list(revs);
	if (revs->topo_order)
		sort_in_topological_order(&revs->commits, revs->lifo);
}

static int rewrite_one(struct commit **pp)
{
	for (;;) {
		struct commit *p = *pp;
		if (p->object.flags & (TREECHANGE | UNINTERESTING))
			return 0;
		if (!p->parents)
			return -1;
		*pp = p->parents->item;
	}
}

static void rewrite_parents(struct commit *commit)
{
	struct commit_list **pp = &commit->parents;
	while (*pp) {
		struct commit_list *parent = *pp;
		if (rewrite_one(&parent->item) < 0) {
			*pp = parent->next;
			continue;
		}
		pp = &parent->next;
	}
}

struct commit *get_revision(struct rev_info *revs)
{
	struct commit_list *list = revs->commits;

	if (!list)
		return NULL;

	/* Check the max_count ... */
	switch (revs->max_count) {
	case -1:
		break;
	case 0:
		return NULL;
	default:
		revs->max_count--;
	}

	do {
		struct commit *commit = revs->commits->item;

		if (commit->object.flags & (UNINTERESTING|SHOWN))
			goto next;
		if (revs->min_age != -1 && (commit->date > revs->min_age))
			goto next;
		if (revs->max_age != -1 && (commit->date < revs->max_age))
			return NULL;
		if (revs->no_merges && commit->parents && commit->parents->next)
			goto next;
		if (revs->paths && revs->dense) {
			if (!(commit->object.flags & TREECHANGE))
				goto next;
			rewrite_parents(commit);
		}
		/* More to go? */
		if (revs->max_count)
			pop_most_recent_commit(&revs->commits, SEEN);
		commit->object.flags |= SHOWN;
		return commit;
next:
		pop_most_recent_commit(&revs->commits, SEEN);
	} while (revs->commits);
	return NULL;
}