builtin/merge-base.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "commit.h"
   4 #include "parse-options.h"
   5
   6 static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
   7 {
   8         struct commit_list *result;
   9
  10         result = get_merge_bases_many(rev[0], rev_nr - 1, rev + 1, 0);
  11
  12         if (!result)
  13                 return 1;
  14
  15         while (result) {
  16                 printf("%s\n", sha1_to_hex(result->item->object.sha1));
  17                 if (!show_all)
  18                         return 0;
  19                 result = result->next;
  20         }
  21
  22         return 0;
  23 }
  24
  25 static const char * const merge_base_usage[] = {
  26         N_("git merge-base [-a|--all] <commit> <commit>..."),
  27         N_("git merge-base [-a|--all] --octopus <commit>..."),
  28         N_("git merge-base --independent <commit>..."),
  29         N_("git merge-base --is-ancestor <commit> <commit>"),
  30         NULL
  31 };
  32
  33 static struct commit *get_commit_reference(const char *arg)
  34 {
  35         unsigned char revkey[20];
  36         struct commit *r;
  37
  38         if (get_sha1(arg, revkey))
  39                 die("Not a valid object name %s", arg);
  40         r = lookup_commit_reference(revkey);
  41         if (!r)
  42                 die("Not a valid commit name %s", arg);
  43
  44         return r;
  45 }
  46
  47 static int handle_octopus(int count, const char **args, int reduce, int show_all)
  48 {
  49         struct commit_list *revs = NULL;
  50         struct commit_list *result;
  51         int i;
  52
  53         if (reduce)
  54                 show_all = 1;
  55
  56         for (i = count - 1; i >= 0; i--)
  57                 commit_list_insert(get_commit_reference(args[i]), &revs);
  58
  59         result = reduce ? reduce_heads(revs) : get_octopus_merge_bases(revs);
  60
  61         if (!result)
  62                 return 1;
  63
  64         while (result) {
  65                 printf("%s\n", sha1_to_hex(result->item->object.sha1));
  66                 if (!show_all)
  67                         return 0;
  68                 result = result->next;
  69         }
  70
  71         return 0;
  72 }
  73
  74 static int handle_is_ancestor(int argc, const char **argv)
  75 {
  76         struct commit *one, *two;
  77
  78         if (argc != 2)
  79                 die("--is-ancestor takes exactly two commits");
  80         one = get_commit_reference(argv[0]);
  81         two = get_commit_reference(argv[1]);
  82         if (in_merge_bases(one, two))
  83                 return 0;
  84         else
  85                 return 1;
  86 }
  87
  88 int cmd_merge_base(int argc, const char **argv, const char *prefix)
  89 {
  90         struct commit **rev;
  91         int rev_nr = 0;
  92         int show_all = 0;
  93         int octopus = 0;
  94         int reduce = 0;
  95         int is_ancestor = 0;
  96
  97         struct option options[] = {
  98                 OPT_BOOLEAN('a', "all", &show_all, N_("output all common ancestors")),
  99                 OPT_BOOLEAN(0, "octopus", &octopus, N_("find ancestors for a single n-way merge")),
 100                 OPT_BOOLEAN(0, "independent", &reduce, N_("list revs not reachable from others")),
 101                 OPT_BOOLEAN(0, "is-ancestor", &is_ancestor,
 102                             N_("is the first one ancestor of the other?")),
 103                 OPT_END()
 104         };
 105
 106         git_config(git_default_config, NULL);
 107         argc = parse_options(argc, argv, prefix, options, merge_base_usage, 0);
 108         if (!octopus && !reduce && argc < 2)
 109                 usage_with_options(merge_base_usage, options);
 110         if (is_ancestor && (show_all | octopus | reduce))
 111                 die("--is-ancestor cannot be used with other options");
 112         if (is_ancestor)
 113                 return handle_is_ancestor(argc, argv);
 114         if (reduce && (show_all || octopus))
 115                 die("--independent cannot be used with other options");
 116
 117         if (octopus || reduce)
 118                 return handle_octopus(argc, argv, reduce, show_all);
 119
 120         rev = xmalloc(argc * sizeof(*rev));
 121         while (argc-- > 0)
 122                 rev[rev_nr++] = get_commit_reference(*argv++);
 123         return show_merge_base(rev, rev_nr, show_all);
 124 }