Andrew's git - gitweb.git/blob - builtin/merge-base.c

   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
  10static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
  11{
  12        struct commit_list *result;
  13
  14        result = get_merge_bases_many_dirty(rev[0], rev_nr - 1, rev + 1);
  15
  16        if (!result)
  17                return 1;
  18
  19        while (result) {
  20                printf("%s\n", oid_to_hex(&result->item->object.oid));
  21                if (!show_all)
  22                        return 0;
  23                result = result->next;
  24        }
  25
  26        return 0;
  27}
  28
  29static const char * const merge_base_usage[] = {
  30        N_("git merge-base [-a | --all] <commit> <commit>..."),
  31        N_("git merge-base [-a | --all] --octopus <commit>..."),
  32        N_("git merge-base --independent <commit>..."),
  33        N_("git merge-base --is-ancestor <commit> <commit>"),
  34        N_("git merge-base --fork-point <ref> [<commit>]"),
  35        NULL
  36};
  37
  38static struct commit *get_commit_reference(const char *arg)
  39{
  40        struct object_id revkey;
  41        struct commit *r;
  42
  43        if (get_oid(arg, &revkey))
  44                die("Not a valid object name %s", arg);
  45        r = lookup_commit_reference(&revkey);
  46        if (!r)
  47                die("Not a valid commit name %s", arg);
  48
  49        return r;
  50}
  51
  52static int handle_independent(int count, const char **args)
  53{
  54        struct commit_list *revs = NULL;
  55        struct commit_list *result;
  56        int i;
  57
  58        for (i = count - 1; i >= 0; i--)
  59                commit_list_insert(get_commit_reference(args[i]), &revs);
  60
  61        result = reduce_heads(revs);
  62        if (!result)
  63                return 1;
  64
  65        while (result) {
  66                printf("%s\n", oid_to_hex(&result->item->object.oid));
  67                result = result->next;
  68        }
  69        return 0;
  70}
  71
  72static int handle_octopus(int count, const char **args, int show_all)
  73{
  74        struct commit_list *revs = NULL;
  75        struct commit_list *result;
  76        int i;
  77
  78        for (i = count - 1; i >= 0; i--)
  79                commit_list_insert(get_commit_reference(args[i]), &revs);
  80
  81        result = reduce_heads(get_octopus_merge_bases(revs));
  82
  83        if (!result)
  84                return 1;
  85
  86        while (result) {
  87                printf("%s\n", oid_to_hex(&result->item->object.oid));
  88                if (!show_all)
  89                        return 0;
  90                result = result->next;
  91        }
  92
  93        return 0;
  94}
  95
  96static int handle_is_ancestor(int argc, const char **argv)
  97{
  98        struct commit *one, *two;
  99
 100        if (argc != 2)
 101                die("--is-ancestor takes exactly two commits");
 102        one = get_commit_reference(argv[0]);
 103        two = get_commit_reference(argv[1]);
 104        if (in_merge_bases(one, two))
 105                return 0;
 106        else
 107                return 1;
 108}
 109
 110struct rev_collect {
 111        struct commit **commit;
 112        int nr;
 113        int alloc;
 114        unsigned int initial : 1;
 115};
 116
 117static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
 118{
 119        struct commit *commit;
 120
 121        if (is_null_oid(oid))
 122                return;
 123
 124        commit = lookup_commit(oid);
 125        if (!commit ||
 126            (commit->object.flags & TMP_MARK) ||
 127            parse_commit(commit))
 128                return;
 129
 130        ALLOC_GROW(revs->commit, revs->nr + 1, revs->alloc);
 131        revs->commit[revs->nr++] = commit;
 132        commit->object.flags |= TMP_MARK;
 133}
 134
 135static int collect_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 136                                  const char *ident, timestamp_t timestamp,
 137                                  int tz, const char *message, void *cbdata)
 138{
 139        struct rev_collect *revs = cbdata;
 140
 141        if (revs->initial) {
 142                revs->initial = 0;
 143                add_one_commit(ooid, revs);
 144        }
 145        add_one_commit(noid, revs);
 146        return 0;
 147}
 148
 149static int handle_fork_point(int argc, const char **argv)
 150{
 151        struct object_id oid;
 152        char *refname;
 153        const char *commitname;
 154        struct rev_collect revs;
 155        struct commit *derived;
 156        struct commit_list *bases;
 157        int i, ret = 0;
 158
 159        switch (dwim_ref(argv[0], strlen(argv[0]), oid.hash, &refname)) {
 160        case 0:
 161                die("No such ref: '%s'", argv[0]);
 162        case 1:
 163                break; /* good */
 164        default:
 165                die("Ambiguous refname: '%s'", argv[0]);
 166        }
 167
 168        commitname = (argc == 2) ? argv[1] : "HEAD";
 169        if (get_oid(commitname, &oid))
 170                die("Not a valid object name: '%s'", commitname);
 171
 172        derived = lookup_commit_reference(&oid);
 173        memset(&revs, 0, sizeof(revs));
 174        revs.initial = 1;
 175        for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
 176
 177        if (!revs.nr && !get_oid(refname, &oid))
 178                add_one_commit(&oid, &revs);
 179
 180        for (i = 0; i < revs.nr; i++)
 181                revs.commit[i]->object.flags &= ~TMP_MARK;
 182
 183        bases = get_merge_bases_many_dirty(derived, revs.nr, revs.commit);
 184
 185        /*
 186         * There should be one and only one merge base, when we found
 187         * a common ancestor among reflog entries.
 188         */
 189        if (!bases || bases->next) {
 190                ret = 1;
 191                goto cleanup_return;
 192        }
 193
 194        /* And the found one must be one of the reflog entries */
 195        for (i = 0; i < revs.nr; i++)
 196                if (&bases->item->object == &revs.commit[i]->object)
 197                        break; /* found */
 198        if (revs.nr <= i) {
 199                ret = 1; /* not found */
 200                goto cleanup_return;
 201        }
 202
 203        printf("%s\n", oid_to_hex(&bases->item->object.oid));
 204
 205cleanup_return:
 206        free_commit_list(bases);
 207        return ret;
 208}
 209
 210int cmd_merge_base(int argc, const char **argv, const char *prefix)
 211{
 212        struct commit **rev;
 213        int rev_nr = 0;
 214        int show_all = 0;
 215        int cmdmode = 0;
 216
 217        struct option options[] = {
 218                OPT_BOOL('a', "all", &show_all, N_("output all common ancestors")),
 219                OPT_CMDMODE(0, "octopus", &cmdmode,
 220                            N_("find ancestors for a single n-way merge"), 'o'),
 221                OPT_CMDMODE(0, "independent", &cmdmode,
 222                            N_("list revs not reachable from others"), 'r'),
 223                OPT_CMDMODE(0, "is-ancestor", &cmdmode,
 224                            N_("is the first one ancestor of the other?"), 'a'),
 225                OPT_CMDMODE(0, "fork-point", &cmdmode,
 226                            N_("find where <commit> forked from reflog of <ref>"), 'f'),
 227                OPT_END()
 228        };
 229
 230        git_config(git_default_config, NULL);
 231        argc = parse_options(argc, argv, prefix, options, merge_base_usage, 0);
 232
 233        if (cmdmode == 'a') {
 234                if (argc < 2)
 235                        usage_with_options(merge_base_usage, options);
 236                if (show_all)
 237                        die("--is-ancestor cannot be used with --all");
 238                return handle_is_ancestor(argc, argv);
 239        }
 240
 241        if (cmdmode == 'r' && show_all)
 242                die("--independent cannot be used with --all");
 243
 244        if (cmdmode == 'o')
 245                return handle_octopus(argc, argv, show_all);
 246
 247        if (cmdmode == 'r')
 248                return handle_independent(argc, argv);
 249
 250        if (cmdmode == 'f') {
 251                if (argc < 1 || 2 < argc)
 252                        usage_with_options(merge_base_usage, options);
 253                return handle_fork_point(argc, argv);
 254        }
 255
 256        if (argc < 2)
 257                usage_with_options(merge_base_usage, options);
 258
 259        ALLOC_ARRAY(rev, argc);
 260        while (argc-- > 0)
 261                rev[rev_nr++] = get_commit_reference(*argv++);
 262        return show_merge_base(rev, rev_nr, show_all);
 263}