1 #include "builtin.h"
2 #include "cache.h"
3 #include "config.h"
4 #include "commit.h"
5 #include "refs.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "parse-options.h"
9 #include "repository.h"
10 #include "commit-reach.h"
11 
show_merge_base(struct commit ** rev,int rev_nr,int show_all)12 static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
13 {
14 	struct commit_list *result, *r;
15 
16 	result = get_merge_bases_many_dirty(rev[0], rev_nr - 1, rev + 1);
17 
18 	if (!result)
19 		return 1;
20 
21 	for (r = result; r; r = r->next) {
22 		printf("%s\n", oid_to_hex(&r->item->object.oid));
23 		if (!show_all)
24 			break;
25 	}
26 
27 	free_commit_list(result);
28 	return 0;
29 }
30 
31 static const char * const merge_base_usage[] = {
32 	N_("git merge-base [-a | --all] <commit> <commit>..."),
33 	N_("git merge-base [-a | --all] --octopus <commit>..."),
34 	N_("git merge-base --independent <commit>..."),
35 	N_("git merge-base --is-ancestor <commit> <commit>"),
36 	N_("git merge-base --fork-point <ref> [<commit>]"),
37 	NULL
38 };
39 
get_commit_reference(const char * arg)40 static struct commit *get_commit_reference(const char *arg)
41 {
42 	struct object_id revkey;
43 	struct commit *r;
44 
45 	if (get_oid(arg, &revkey))
46 		die("Not a valid object name %s", arg);
47 	r = lookup_commit_reference(the_repository, &revkey);
48 	if (!r)
49 		die("Not a valid commit name %s", arg);
50 
51 	return r;
52 }
53 
handle_independent(int count,const char ** args)54 static int handle_independent(int count, const char **args)
55 {
56 	struct commit_list *revs = NULL, *rev;
57 	int i;
58 
59 	for (i = count - 1; i >= 0; i--)
60 		commit_list_insert(get_commit_reference(args[i]), &revs);
61 
62 	reduce_heads_replace(&revs);
63 
64 	if (!revs)
65 		return 1;
66 
67 	for (rev = revs; rev; rev = rev->next)
68 		printf("%s\n", oid_to_hex(&rev->item->object.oid));
69 
70 	free_commit_list(revs);
71 	return 0;
72 }
73 
handle_octopus(int count,const char ** args,int show_all)74 static int handle_octopus(int count, const char **args, int show_all)
75 {
76 	struct commit_list *revs = NULL;
77 	struct commit_list *result, *rev;
78 	int i;
79 
80 	for (i = count - 1; i >= 0; i--)
81 		commit_list_insert(get_commit_reference(args[i]), &revs);
82 
83 	result = get_octopus_merge_bases(revs);
84 	free_commit_list(revs);
85 	reduce_heads_replace(&result);
86 
87 	if (!result)
88 		return 1;
89 
90 	for (rev = result; rev; rev = rev->next) {
91 		printf("%s\n", oid_to_hex(&rev->item->object.oid));
92 		if (!show_all)
93 			break;
94 	}
95 
96 	free_commit_list(result);
97 	return 0;
98 }
99 
handle_is_ancestor(int argc,const char ** argv)100 static int handle_is_ancestor(int argc, const char **argv)
101 {
102 	struct commit *one, *two;
103 
104 	if (argc != 2)
105 		die("--is-ancestor takes exactly two commits");
106 	one = get_commit_reference(argv[0]);
107 	two = get_commit_reference(argv[1]);
108 	if (in_merge_bases(one, two))
109 		return 0;
110 	else
111 		return 1;
112 }
113 
handle_fork_point(int argc,const char ** argv)114 static int handle_fork_point(int argc, const char **argv)
115 {
116 	struct object_id oid;
117 	struct commit *derived, *fork_point;
118 	const char *commitname;
119 
120 	commitname = (argc == 2) ? argv[1] : "HEAD";
121 	if (get_oid(commitname, &oid))
122 		die("Not a valid object name: '%s'", commitname);
123 
124 	derived = lookup_commit_reference(the_repository, &oid);
125 
126 	fork_point = get_fork_point(argv[0], derived);
127 
128 	if (!fork_point)
129 		return 1;
130 
131 	printf("%s\n", oid_to_hex(&fork_point->object.oid));
132 	return 0;
133 }
134 
cmd_merge_base(int argc,const char ** argv,const char * prefix)135 int cmd_merge_base(int argc, const char **argv, const char *prefix)
136 {
137 	struct commit **rev;
138 	int rev_nr = 0;
139 	int show_all = 0;
140 	int cmdmode = 0;
141 
142 	struct option options[] = {
143 		OPT_BOOL('a', "all", &show_all, N_("output all common ancestors")),
144 		OPT_CMDMODE(0, "octopus", &cmdmode,
145 			    N_("find ancestors for a single n-way merge"), 'o'),
146 		OPT_CMDMODE(0, "independent", &cmdmode,
147 			    N_("list revs not reachable from others"), 'r'),
148 		OPT_CMDMODE(0, "is-ancestor", &cmdmode,
149 			    N_("is the first one ancestor of the other?"), 'a'),
150 		OPT_CMDMODE(0, "fork-point", &cmdmode,
151 			    N_("find where <commit> forked from reflog of <ref>"), 'f'),
152 		OPT_END()
153 	};
154 
155 	git_config(git_default_config, NULL);
156 	argc = parse_options(argc, argv, prefix, options, merge_base_usage, 0);
157 
158 	if (cmdmode == 'a') {
159 		if (argc < 2)
160 			usage_with_options(merge_base_usage, options);
161 		if (show_all)
162 			die("--is-ancestor cannot be used with --all");
163 		return handle_is_ancestor(argc, argv);
164 	}
165 
166 	if (cmdmode == 'r' && show_all)
167 		die("--independent cannot be used with --all");
168 
169 	if (cmdmode == 'o')
170 		return handle_octopus(argc, argv, show_all);
171 
172 	if (cmdmode == 'r')
173 		return handle_independent(argc, argv);
174 
175 	if (cmdmode == 'f') {
176 		if (argc < 1 || 2 < argc)
177 			usage_with_options(merge_base_usage, options);
178 		return handle_fork_point(argc, argv);
179 	}
180 
181 	if (argc < 2)
182 		usage_with_options(merge_base_usage, options);
183 
184 	ALLOC_ARRAY(rev, argc);
185 	while (argc-- > 0)
186 		rev[rev_nr++] = get_commit_reference(*argv++);
187 	return show_merge_base(rev, rev_nr, show_all);
188 }
189