[thirdparty/git.git] / revision.c

#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;
		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;
}
Commit	Line	Data
ae563542 LT	1	#include "cache.h"
	2	#include "tag.h"
	3	#include "blob.h"
	4	#include "tree.h"
	5	#include "commit.h"
a4a88b2b	6	#include "diff.h"
ae563542 LT	7	#include "refs.h"
	8	#include "revision.h"
	9
	10	static char path_name(struct name_path path, const char *name)
	11	{
	12	struct name_path *p;
	13	char n, m;
	14	int nlen = strlen(name);
	15	int len = nlen + 1;
	16
	17	for (p = path; p; p = p->up) {
	18	if (p->elem_len)
	19	len += p->elem_len + 1;
	20	}
	21	n = xmalloc(len);
	22	m = n + len - (nlen + 1);
	23	strcpy(m, name);
	24	for (p = path; p; p = p->up) {
	25	if (p->elem_len) {
	26	m -= p->elem_len + 1;
	27	memcpy(m, p->elem, p->elem_len);
	28	m[p->elem_len] = '/';
	29	}
	30	}
	31	return n;
	32	}
	33
	34	struct object_list *add_object(struct object obj,
	35	struct object_list **p,
	36	struct name_path *path,
	37	const char *name)
	38	{
	39	struct object_list entry = xmalloc(sizeof(entry));
	40	entry->item = obj;
	41	entry->next = *p;
	42	entry->name = path_name(path, name);
	43	*p = entry;
	44	return &entry->next;
	45	}
	46
	47	static void mark_blob_uninteresting(struct blob *blob)
	48	{
	49	if (blob->object.flags & UNINTERESTING)
	50	return;
	51	blob->object.flags \|= UNINTERESTING;
	52	}
	53
	54	void mark_tree_uninteresting(struct tree *tree)
	55	{
	56	struct object *obj = &tree->object;
	57	struct tree_entry_list *entry;
	58
	59	if (obj->flags & UNINTERESTING)
	60	return;
	61	obj->flags \|= UNINTERESTING;
	62	if (!has_sha1_file(obj->sha1))
	63	return;
	64	if (parse_tree(tree) < 0)
	65	die("bad tree %s", sha1_to_hex(obj->sha1));
	66	entry = tree->entries;
	67	tree->entries = NULL;
	68	while (entry) {
	69	struct tree_entry_list *next = entry->next;
	70	if (entry->directory)
71	mark_tree_uninteresting(entry->item.tree);
72	else
73	mark_blob_uninteresting(entry->item.blob);
74	free(entry);
75	entry = next;
76	}
77	}
78
79	void mark_parents_uninteresting(struct commit *commit)
80	{
81	struct commit_list *parents = commit->parents;
82
83	while (parents) {
84	struct commit *commit = parents->item;
85	commit->object.flags \|= UNINTERESTING;
86
87	/*
88	* Normally we haven't parsed the parent
89	* yet, so we won't have a parent of a parent
90	* here. However, it may turn out that we've
91	* reached this commit some other way (where it
92	* wasn't uninteresting), in which case we need
93	* to mark its parents recursively too..
94	*/
95	if (commit->parents)
96	mark_parents_uninteresting(commit);
97
98	/*
99	* A missing commit is ok iff its parent is marked
100	* uninteresting.
101	*
102	* We just mark such a thing parsed, so that when
103	* it is popped next time around, we won't be trying
104	* to parse it and get an error.
105	*/
106	if (!has_sha1_file(commit->object.sha1))
107	commit->object.parsed = 1;
108	parents = parents->next;
109	}
110	}
111
112	static void add_pending_object(struct rev_info revs, struct object obj, const char *name)
113	{
114	add_object(obj, &revs->pending_objects, NULL, name);
115	}
116
117	static struct commit get_commit_reference(struct rev_info revs, const char name, const unsigned char sha1, unsigned int flags)
118	{
119	struct object *object;
120
121	object = parse_object(sha1);
122	if (!object)
123	die("bad object %s", name);
124
125	/*
126	* Tag object? Look what it points to..
127	*/
128	while (object->type == tag_type) {
129	struct tag tag = (struct tag ) object;
130	object->flags \|= flags;
131	if (revs->tag_objects && !(object->flags & UNINTERESTING))
132	add_pending_object(revs, object, tag->tag);
133	object = parse_object(tag->tagged->sha1);
134	if (!object)
135	die("bad object %s", sha1_to_hex(tag->tagged->sha1));
136	}
137
138	/*
139	* Commit object? Just return it, we'll do all the complex
140	* reachability crud.
141	*/
142	if (object->type == commit_type) {
143	struct commit commit = (struct commit )object;
144	object->flags \|= flags;
145	if (parse_commit(commit) < 0)
146	die("unable to parse commit %s", name);
d9a83684	147	if (flags & UNINTERESTING) {
ae563542	148	mark_parents_uninteresting(commit);
d9a83684 LT	149	revs->limited = 1;
d9a83684 LT	150	}
ae563542 LT	151	return commit;
	152	}
	153
	154	/*
	155	* Tree object? Either mark it uniniteresting, or add it
	156	* to the list of objects to look at later..
	157	*/
	158	if (object->type == tree_type) {
	159	struct tree tree = (struct tree )object;
	160	if (!revs->tree_objects)
	161	return NULL;
	162	if (flags & UNINTERESTING) {
	163	mark_tree_uninteresting(tree);
	164	return NULL;
	165	}
	166	add_pending_object(revs, object, "");
	167	return NULL;
	168	}
	169
	170	/*
	171	* Blob object? You know the drill by now..
	172	*/
	173	if (object->type == blob_type) {
	174	struct blob blob = (struct blob )object;
	175	if (!revs->blob_objects)
	176	return NULL;
	177	if (flags & UNINTERESTING) {
	178	mark_blob_uninteresting(blob);
	179	return NULL;
	180	}
	181	add_pending_object(revs, object, "");
	182	return NULL;
	183	}
	184	die("%s is unknown object", name);
	185	}
	186
a4a88b2b LT	187	static int everybody_uninteresting(struct commit_list *orig)
	188	{
	189	struct commit_list *list = orig;
	190	while (list) {
	191	struct commit *commit = list->item;
	192	list = list->next;
	193	if (commit->object.flags & UNINTERESTING)
	194	continue;
	195	return 0;
	196	}
	197	return 1;
	198	}
	199
	200	#define TREE_SAME 0
	201	#define TREE_NEW 1
	202	#define TREE_DIFFERENT 2
	203	static int tree_difference = TREE_SAME;
	204
	205	static void file_add_remove(struct diff_options *options,
	206	int addremove, unsigned mode,
	207	const unsigned char *sha1,
	208	const char base, const char path)
	209	{
	210	int diff = TREE_DIFFERENT;
	211
	212	/*
	213	* Is it an add of a new file? It means that
	214	* the old tree didn't have it at all, so we
	215	* will turn "TREE_SAME" -> "TREE_NEW", but
	216	* leave any "TREE_DIFFERENT" alone (and if
	217	* it already was "TREE_NEW", we'll keep it
	218	* "TREE_NEW" of course).
	219	*/
	220	if (addremove == '+') {
	221	diff = tree_difference;
	222	if (diff != TREE_SAME)
	223	return;
	224	diff = TREE_NEW;
	225	}
	226	tree_difference = diff;
	227	}
	228
	229	static void file_change(struct diff_options *options,
	230	unsigned old_mode, unsigned new_mode,
	231	const unsigned char *old_sha1,
	232	const unsigned char *new_sha1,
	233	const char base, const char path)
	234	{
	235	tree_difference = TREE_DIFFERENT;
	236	}
	237
	238	static struct diff_options diff_opt = {
	239	.recursive = 1,
	240	.add_remove = file_add_remove,
	241	.change = file_change,
	242	};
	243
	244	static int compare_tree(struct tree t1, struct tree t2)
	245	{
	246	if (!t1)
	247	return TREE_NEW;
	248	if (!t2)
	249	return TREE_DIFFERENT;
	250	tree_difference = TREE_SAME;
251	if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
252	return TREE_DIFFERENT;
253	return tree_difference;
254	}
255
256	static int same_tree_as_empty(struct tree *t1)
257	{
258	int retval;
259	void *tree;
260	struct tree_desc empty, real;
261
262	if (!t1)
263	return 0;
264
265	tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
266	if (!tree)
267	return 0;
268	real.buf = tree;
269
270	empty.buf = "";
271	empty.size = 0;
272
273	tree_difference = 0;
274	retval = diff_tree(&empty, &real, "", &diff_opt);
275	free(tree);
276
277	return retval >= 0 && !tree_difference;
278	}
279
280	static void try_to_simplify_commit(struct rev_info revs, struct commit commit)
281	{
282	struct commit_list *pp, parent;
283
284	if (!commit->tree)
285	return;
286
287	if (!commit->parents) {
288	if (!same_tree_as_empty(commit->tree))
289	commit->object.flags \|= TREECHANGE;
290	return;
291	}
292
293	pp = &commit->parents;
294	while ((parent = *pp) != NULL) {
295	struct commit *p = parent->item;
296
297	if (p->object.flags & UNINTERESTING) {
298	pp = &parent->next;
299	continue;
300	}
301
302	parse_commit(p);
303	switch (compare_tree(p->tree, commit->tree)) {
304	case TREE_SAME:
305	parent->next = NULL;
306	commit->parents = parent;
307	return;
308
309	case TREE_NEW:
310	if (revs->remove_empty_trees && same_tree_as_empty(p->tree)) {
311	*pp = parent->next;
312	continue;
313	}
314	/* fallthrough */
315	case TREE_DIFFERENT:
316	pp = &parent->next;
317	continue;
318	}
319	die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
320	}
321	commit->object.flags \|= TREECHANGE;
322	}
323
324	static void add_parents_to_list(struct rev_info revs, struct commit commit, struct commit_list **list)
325	{
326	struct commit_list *parent = commit->parents;
327
328	/*
329	* If the commit is uninteresting, don't try to
330	* prune parents - we want the maximal uninteresting
331	* set.
332	*
333	* Normally we haven't parsed the parent
334	* yet, so we won't have a parent of a parent
335	* here. However, it may turn out that we've
336	* reached this commit some other way (where it
337	* wasn't uninteresting), in which case we need
338	* to mark its parents recursively too..
339	*/
340	if (commit->object.flags & UNINTERESTING) {
341	while (parent) {
342	struct commit *p = parent->item;
343	parent = parent->next;
344	parse_commit(p);
345	p->object.flags \|= UNINTERESTING;
346	if (p->parents)
347	mark_parents_uninteresting(p);
348	if (p->object.flags & SEEN)
349	continue;
350	p->object.flags \|= SEEN;
351	insert_by_date(p, list);
352	}
353	return;
354	}
355
356	/*
357	* Ok, the commit wasn't uninteresting. Try to
358	* simplify the commit history and find the parent
359	* that has no differences in the path set if one exists.
360	*/
361	if (revs->paths)
362	try_to_simplify_commit(revs, commit);
363
364	parent = commit->parents;
365	while (parent) {
366	struct commit *p = parent->item;
367
368	parent = parent->next;
369
370	parse_commit(p);
371	if (p->object.flags & SEEN)
372	continue;
373	p->object.flags \|= SEEN;
374	insert_by_date(p, list);
375	}
376	}
377
378	static void limit_list(struct rev_info *revs)
379	{
380	struct commit_list *list = revs->commits;
381	struct commit_list *newlist = NULL;
382	struct commit_list **p = &newlist;
383
765ac8ec LT	384	if (revs->paths)
	385	diff_tree_setup_paths(revs->paths);
	386
a4a88b2b LT	387	while (list) {
	388	struct commit_list *entry = list;
	389	struct commit *commit = list->item;
	390	struct object *obj = &commit->object;
	391
	392	list = list->next;
	393	free(entry);
	394
	395	if (revs->max_age != -1 && (commit->date < revs->max_age))
	396	obj->flags \|= UNINTERESTING;
	397	if (revs->unpacked && has_sha1_pack(obj->sha1))
	398	obj->flags \|= UNINTERESTING;
	399	add_parents_to_list(revs, commit, &list);
	400	if (obj->flags & UNINTERESTING) {
	401	mark_parents_uninteresting(commit);
	402	if (everybody_uninteresting(list))
	403	break;
	404	continue;
	405	}
	406	if (revs->min_age != -1 && (commit->date > revs->min_age))
	407	continue;
	408	p = &commit_list_insert(commit, p)->next;
	409	}
	410	revs->commits = newlist;
	411	}
	412
ae563542 LT	413	static void add_one_commit(struct commit commit, struct rev_info revs)
	414	{
	415	if (!commit \|\| (commit->object.flags & SEEN))
	416	return;
	417	commit->object.flags \|= SEEN;
	418	commit_list_insert(commit, &revs->commits);
	419	}
	420
	421	static int all_flags;
	422	static struct rev_info *all_revs;
	423
	424	static int handle_one_ref(const char path, const unsigned char sha1)
	425	{
	426	struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
	427	add_one_commit(commit, all_revs);
	428	return 0;
	429	}
	430
	431	static void handle_all(struct rev_info *revs, unsigned flags)
	432	{
	433	all_revs = revs;
	434	all_flags = flags;
	435	for_each_ref(handle_one_ref);
	436	}
	437
	438	/*
	439	* Parse revision information, filling in the "rev_info" structure,
	440	* and removing the used arguments from the argument list.
	441	*
765ac8ec LT	442	* Returns the number of arguments left that weren't recognized
765ac8ec LT	443	* (which are also moved to the head of the argument list)
ae563542	444	*/
a4a88b2b	445	int setup_revisions(int argc, const char *argv, struct rev_info revs, const char *def)
ae563542 LT	446	{
ae563542 LT	447	int i, flags, seen_dashdash;
765ac8ec	448	const char **unrecognized = argv + 1;
ae563542 LT	449	int left = 1;
	450
	451	memset(revs, 0, sizeof(*revs));
	452	revs->lifo = 1;
	453	revs->dense = 1;
	454	revs->prefix = setup_git_directory();
	455	revs->max_age = -1;
	456	revs->min_age = -1;
	457	revs->max_count = -1;
	458
	459	/* First, search for "--" */
	460	seen_dashdash = 0;
	461	for (i = 1; i < argc; i++) {
	462	const char *arg = argv[i];
	463	if (strcmp(arg, "--"))
	464	continue;
	465	argv[i] = NULL;
	466	argc = i;
	467	revs->paths = get_pathspec(revs->prefix, argv + i + 1);
	468	seen_dashdash = 1;
	469	break;
	470	}
	471
	472	flags = 0;
	473	for (i = 1; i < argc; i++) {
	474	struct commit *commit;
	475	const char *arg = argv[i];
	476	unsigned char sha1[20];
	477	char *dotdot;
	478	int local_flags;
	479
	480	if (*arg == '-') {
	481	if (!strncmp(arg, "--max-count=", 12)) {
	482	revs->max_count = atoi(arg + 12);
	483	continue;
	484	}
64bc6e3d JH	485	/* accept -<digit>, like traditilnal "head" */
	486	if ((*arg == '-') && isdigit(arg[1])) {
	487	revs->max_count = atoi(arg + 1);
	488	continue;
	489	}
	490	if (!strcmp(arg, "-n")) {
	491	if (argc <= i + 1)
	492	die("-n requires an argument");
	493	revs->max_count = atoi(argv[++i]);
	494	continue;
	495	}
	496	if (!strncmp(arg,"-n",2)) {
	497	revs->max_count = atoi(arg + 2);
	498	continue;
	499	}
ae563542 LT	500	if (!strncmp(arg, "--max-age=", 10)) {
ae563542 LT	501	revs->max_age = atoi(arg + 10);
d9a83684	502	revs->limited = 1;
ae563542 LT	503	continue;
	504	}
	505	if (!strncmp(arg, "--min-age=", 10)) {
	506	revs->min_age = atoi(arg + 10);
d9a83684	507	revs->limited = 1;
ae563542 LT	508	continue;
ae563542 LT	509	}
fd751667 JH	510	if (!strncmp(arg, "--since=", 8)) {
	511	revs->max_age = approxidate(arg + 8);
	512	revs->limited = 1;
	513	continue;
	514	}
	515	if (!strncmp(arg, "--after=", 8)) {
	516	revs->max_age = approxidate(arg + 8);
	517	revs->limited = 1;
	518	continue;
	519	}
	520	if (!strncmp(arg, "--before=", 9)) {
	521	revs->min_age = approxidate(arg + 9);
	522	revs->limited = 1;
	523	continue;
	524	}
	525	if (!strncmp(arg, "--until=", 8)) {
	526	revs->min_age = approxidate(arg + 8);
	527	revs->limited = 1;
	528	continue;
	529	}
ae563542 LT	530	if (!strcmp(arg, "--all")) {
	531	handle_all(revs, flags);
	532	continue;
	533	}
	534	if (!strcmp(arg, "--not")) {
	535	flags ^= UNINTERESTING;
	536	continue;
	537	}
	538	if (!strcmp(arg, "--default")) {
	539	if (++i >= argc)
	540	die("bad --default argument");
	541	def = argv[i];
	542	continue;
	543	}
	544	if (!strcmp(arg, "--topo-order")) {
	545	revs->topo_order = 1;
d9a83684	546	revs->limited = 1;
ae563542 LT	547	continue;
	548	}
	549	if (!strcmp(arg, "--date-order")) {
	550	revs->lifo = 0;
	551	revs->topo_order = 1;
d9a83684	552	revs->limited = 1;
ae563542 LT	553	continue;
	554	}
	555	if (!strcmp(arg, "--dense")) {
	556	revs->dense = 1;
	557	continue;
	558	}
	559	if (!strcmp(arg, "--sparse")) {
	560	revs->dense = 0;
	561	continue;
	562	}
	563	if (!strcmp(arg, "--remove-empty")) {
	564	revs->remove_empty_trees = 1;
	565	continue;
	566	}
765ac8ec LT	567	if (!strncmp(arg, "--no-merges", 11)) {
	568	revs->no_merges = 1;
	569	continue;
	570	}
ae563542 LT	571	if (!strcmp(arg, "--objects")) {
	572	revs->tag_objects = 1;
	573	revs->tree_objects = 1;
	574	revs->blob_objects = 1;
	575	continue;
	576	}
	577	if (!strcmp(arg, "--objects-edge")) {
	578	revs->tag_objects = 1;
	579	revs->tree_objects = 1;
	580	revs->blob_objects = 1;
	581	revs->edge_hint = 1;
	582	continue;
	583	}
d9a83684 LT	584	if (!strcmp(arg, "--unpacked")) {
	585	revs->unpacked = 1;
	586	revs->limited = 1;
	587	continue;
	588	}
ae563542 LT	589	*unrecognized++ = arg;
	590	left++;
	591	continue;
	592	}
	593	dotdot = strstr(arg, "..");
	594	if (dotdot) {
	595	unsigned char from_sha1[20];
	596	char *next = dotdot + 2;
	597	*dotdot = 0;
	598	if (!*next)
	599	next = "HEAD";
	600	if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
	601	struct commit *exclude;
	602	struct commit *include;
	603
	604	exclude = get_commit_reference(revs, arg, from_sha1, flags ^ UNINTERESTING);
	605	include = get_commit_reference(revs, next, sha1, flags);
	606	if (!exclude \|\| !include)
	607	die("Invalid revision range %s..%s", arg, next);
	608	add_one_commit(exclude, revs);
	609	add_one_commit(include, revs);
	610	continue;
	611	}
	612	*dotdot = '.';
	613	}
	614	local_flags = 0;
	615	if (*arg == '^') {
	616	local_flags = UNINTERESTING;
	617	arg++;
	618	}
	619	if (get_sha1(arg, sha1) < 0) {
	620	struct stat st;
	621	int j;
	622
	623	if (seen_dashdash \|\| local_flags)
	624	die("bad revision '%s'", arg);
	625
	626	/* If we didn't have a "--", all filenames must exist */
	627	for (j = i; j < argc; j++) {
	628	if (lstat(argv[j], &st) < 0)
	629	die("'%s': %s", arg, strerror(errno));
	630	}
	631	revs->paths = get_pathspec(revs->prefix, argv + i);
	632	break;
	633	}
	634	commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
	635	add_one_commit(commit, revs);
	636	}
	637	if (def && !revs->commits) {
	638	unsigned char sha1[20];
	639	struct commit *commit;
	640	if (get_sha1(def, sha1) < 0)
	641	die("bad default revision '%s'", def);
	642	commit = get_commit_reference(revs, def, sha1, 0);
	643	add_one_commit(commit, revs);
	644	}
d9a83684 LT	645	if (revs->paths)
d9a83684 LT	646	revs->limited = 1;
ae563542 LT	647	return left;
ae563542 LT	648	}
a4a88b2b LT	649
	650	void prepare_revision_walk(struct rev_info *revs)
	651	{
a4a88b2b LT	652	sort_by_date(&revs->commits);
	653	if (revs->limited)
	654	limit_list(revs);
	655	if (revs->topo_order)
	656	sort_in_topological_order(&revs->commits, revs->lifo);
	657	}
	658
765ac8ec LT	659	static int rewrite_one(struct commit **pp)
	660	{
	661	for (;;) {
	662	struct commit p = pp;
	663	if (p->object.flags & (TREECHANGE \| UNINTERESTING))
	664	return 0;
	665	if (!p->parents)
	666	return -1;
	667	*pp = p->parents->item;
	668	}
	669	}
	670
	671	static void rewrite_parents(struct commit *commit)
	672	{
	673	struct commit_list **pp = &commit->parents;
	674	while (*pp) {
	675	struct commit_list parent = pp;
	676	if (rewrite_one(&parent->item) < 0) {
	677	*pp = parent->next;
	678	continue;
	679	}
	680	pp = &parent->next;
	681	}
	682	}
	683
a4a88b2b LT	684	struct commit get_revision(struct rev_info revs)
a4a88b2b LT	685	{
765ac8ec	686	struct commit_list *list = revs->commits;
765ac8ec LT	687
765ac8ec LT	688	if (!list)
a4a88b2b	689	return NULL;
a4a88b2b	690
765ac8ec	691	/* Check the max_count ... */
765ac8ec LT	692	switch (revs->max_count) {
	693	case -1:
	694	break;
	695	case 0:
	696	return NULL;
	697	default:
	698	revs->max_count--;
	699	}
a4a88b2b	700
765ac8ec	701	do {
ea5ed3ab LT	702	struct commit *commit = revs->commits->item;
ea5ed3ab LT	703
765ac8ec	704	if (commit->object.flags & (UNINTERESTING\|SHOWN))
ea5ed3ab	705	goto next;
765ac8ec	706	if (revs->min_age != -1 && (commit->date > revs->min_age))
ea5ed3ab	707	goto next;
765ac8ec LT	708	if (revs->max_age != -1 && (commit->date < revs->max_age))
	709	return NULL;
	710	if (revs->no_merges && commit->parents && commit->parents->next)
ea5ed3ab	711	goto next;
765ac8ec LT	712	if (revs->paths && revs->dense) {
765ac8ec LT	713	if (!(commit->object.flags & TREECHANGE))
ea5ed3ab	714	goto next;
765ac8ec LT	715	rewrite_parents(commit);
765ac8ec LT	716	}
ea5ed3ab LT	717	/* More to go? */
	718	if (revs->max_count)
	719	pop_most_recent_commit(&revs->commits, SEEN);
765ac8ec LT	720	commit->object.flags \|= SHOWN;
765ac8ec LT	721	return commit;
ea5ed3ab LT	722	next:
ea5ed3ab LT	723	pop_most_recent_commit(&revs->commits, SEEN);
765ac8ec LT	724	} while (revs->commits);
	725	return NULL;
	726	}