9c958bd84b839cb501c977ecb7a23ce5400c3f2c
   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5#include "builtin.h"
   6#include "exec_cmd.h"
   7#include "parse-options.h"
   8
   9#define SEEN            (1u<<0)
  10#define MAX_TAGS        (FLAG_BITS - 1)
  11
  12static const char * const describe_usage[] = {
  13        "git-describe [options] <committish>*",
  14        NULL
  15};
  16
  17static int debug;       /* Display lots of verbose info */
  18static int all; /* Default to annotated tags only */
  19static int tags;        /* But allow any tags if --tags is specified */
  20static int abbrev = DEFAULT_ABBREV;
  21static int max_candidates = 10;
  22const char *pattern = NULL;
  23
  24struct commit_name {
  25        int prio; /* annotated tag = 2, tag = 1, head = 0 */
  26        char path[FLEX_ARRAY]; /* more */
  27};
  28static const char *prio_names[] = {
  29        "head", "lightweight", "annotated",
  30};
  31
  32static void add_to_known_names(const char *path,
  33                               struct commit *commit,
  34                               int prio)
  35{
  36        struct commit_name *e = commit->util;
  37        if (!e || e->prio < prio) {
  38                size_t len = strlen(path)+1;
  39                free(e);
  40                e = xmalloc(sizeof(struct commit_name) + len);
  41                e->prio = prio;
  42                memcpy(e->path, path, len);
  43                commit->util = e;
  44        }
  45}
  46
  47static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  48{
  49        int might_be_tag = !prefixcmp(path, "refs/tags/");
  50        struct commit *commit;
  51        struct object *object;
  52        unsigned char peeled[20];
  53        int is_tag, prio;
  54
  55        if (!all && !might_be_tag)
  56                return 0;
  57
  58        if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  59                commit = lookup_commit_reference_gently(peeled, 1);
  60                if (!commit)
  61                        return 0;
  62                is_tag = !!hashcmp(sha1, commit->object.sha1);
  63        } else {
  64                commit = lookup_commit_reference_gently(sha1, 1);
  65                object = parse_object(sha1);
  66                if (!commit || !object)
  67                        return 0;
  68                is_tag = object->type == OBJ_TAG;
  69        }
  70
  71        /* If --all, then any refs are used.
  72         * If --tags, then any tags are used.
  73         * Otherwise only annotated tags are used.
  74         */
  75        if (might_be_tag) {
  76                if (is_tag) {
  77                        prio = 2;
  78                        if (pattern && fnmatch(pattern, path + 10, 0))
  79                                prio = 0;
  80                } else
  81                        prio = 1;
  82        }
  83        else
  84                prio = 0;
  85
  86        if (!all) {
  87                if (!prio)
  88                        return 0;
  89                if (!tags && prio < 2)
  90                        return 0;
  91        }
  92        add_to_known_names(all ? path + 5 : path + 10, commit, prio);
  93        return 0;
  94}
  95
  96struct possible_tag {
  97        struct commit_name *name;
  98        int depth;
  99        int found_order;
 100        unsigned flag_within;
 101};
 102
 103static int compare_pt(const void *a_, const void *b_)
 104{
 105        struct possible_tag *a = (struct possible_tag *)a_;
 106        struct possible_tag *b = (struct possible_tag *)b_;
 107        if (a->name->prio != b->name->prio)
 108                return b->name->prio - a->name->prio;
 109        if (a->depth != b->depth)
 110                return a->depth - b->depth;
 111        if (a->found_order != b->found_order)
 112                return a->found_order - b->found_order;
 113        return 0;
 114}
 115
 116static unsigned long finish_depth_computation(
 117        struct commit_list **list,
 118        struct possible_tag *best)
 119{
 120        unsigned long seen_commits = 0;
 121        while (*list) {
 122                struct commit *c = pop_commit(list);
 123                struct commit_list *parents = c->parents;
 124                seen_commits++;
 125                if (c->object.flags & best->flag_within) {
 126                        struct commit_list *a = *list;
 127                        while (a) {
 128                                struct commit *i = a->item;
 129                                if (!(i->object.flags & best->flag_within))
 130                                        break;
 131                                a = a->next;
 132                        }
 133                        if (!a)
 134                                break;
 135                } else
 136                        best->depth++;
 137                while (parents) {
 138                        struct commit *p = parents->item;
 139                        parse_commit(p);
 140                        if (!(p->object.flags & SEEN))
 141                                insert_by_date(p, list);
 142                        p->object.flags |= c->object.flags;
 143                        parents = parents->next;
 144                }
 145        }
 146        return seen_commits;
 147}
 148
 149static void describe(const char *arg, int last_one)
 150{
 151        unsigned char sha1[20];
 152        struct commit *cmit, *gave_up_on = NULL;
 153        struct commit_list *list;
 154        static int initialized = 0;
 155        struct commit_name *n;
 156        struct possible_tag all_matches[MAX_TAGS];
 157        unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 158        unsigned long seen_commits = 0;
 159
 160        if (get_sha1(arg, sha1))
 161                die("Not a valid object name %s", arg);
 162        cmit = lookup_commit_reference(sha1);
 163        if (!cmit)
 164                die("%s is not a valid '%s' object", arg, commit_type);
 165
 166        if (!initialized) {
 167                initialized = 1;
 168                for_each_ref(get_name, NULL);
 169        }
 170
 171        n = cmit->util;
 172        if (n) {
 173                printf("%s\n", n->path);
 174                return;
 175        }
 176
 177        if (debug)
 178                fprintf(stderr, "searching to describe %s\n", arg);
 179
 180        list = NULL;
 181        cmit->object.flags = SEEN;
 182        commit_list_insert(cmit, &list);
 183        while (list) {
 184                struct commit *c = pop_commit(&list);
 185                struct commit_list *parents = c->parents;
 186                seen_commits++;
 187                n = c->util;
 188                if (n) {
 189                        if (match_cnt < max_candidates) {
 190                                struct possible_tag *t = &all_matches[match_cnt++];
 191                                t->name = n;
 192                                t->depth = seen_commits - 1;
 193                                t->flag_within = 1u << match_cnt;
 194                                t->found_order = match_cnt;
 195                                c->object.flags |= t->flag_within;
 196                                if (n->prio == 2)
 197                                        annotated_cnt++;
 198                        }
 199                        else {
 200                                gave_up_on = c;
 201                                break;
 202                        }
 203                }
 204                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 205                        struct possible_tag *t = &all_matches[cur_match];
 206                        if (!(c->object.flags & t->flag_within))
 207                                t->depth++;
 208                }
 209                if (annotated_cnt && !list) {
 210                        if (debug)
 211                                fprintf(stderr, "finished search at %s\n",
 212                                        sha1_to_hex(c->object.sha1));
 213                        break;
 214                }
 215                while (parents) {
 216                        struct commit *p = parents->item;
 217                        parse_commit(p);
 218                        if (!(p->object.flags & SEEN))
 219                                insert_by_date(p, &list);
 220                        p->object.flags |= c->object.flags;
 221                        parents = parents->next;
 222                }
 223        }
 224
 225        if (!match_cnt)
 226                die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 227
 228        qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 229
 230        if (gave_up_on) {
 231                insert_by_date(gave_up_on, &list);
 232                seen_commits--;
 233        }
 234        seen_commits += finish_depth_computation(&list, &all_matches[0]);
 235        free_commit_list(list);
 236
 237        if (debug) {
 238                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 239                        struct possible_tag *t = &all_matches[cur_match];
 240                        fprintf(stderr, " %-11s %8d %s\n",
 241                                prio_names[t->name->prio],
 242                                t->depth, t->name->path);
 243                }
 244                fprintf(stderr, "traversed %lu commits\n", seen_commits);
 245                if (gave_up_on) {
 246                        fprintf(stderr,
 247                                "more than %i tags found; listed %i most recent\n"
 248                                "gave up search at %s\n",
 249                                max_candidates, max_candidates,
 250                                sha1_to_hex(gave_up_on->object.sha1));
 251                }
 252        }
 253        if (abbrev == 0)
 254                printf("%s\n", all_matches[0].name->path );
 255        else
 256                printf("%s-%d-g%s\n", all_matches[0].name->path,
 257                       all_matches[0].depth,
 258                       find_unique_abbrev(cmit->object.sha1, abbrev));
 259
 260        if (!last_one)
 261                clear_commit_marks(cmit, -1);
 262}
 263
 264int cmd_describe(int argc, const char **argv, const char *prefix)
 265{
 266        int contains = 0;
 267        struct option options[] = {
 268                OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 269                OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 270                OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 271                OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 272                OPT__ABBREV(&abbrev),
 273                OPT_INTEGER(0, "candidates", &max_candidates,
 274                            "consider <n> most recent tags (default: 10)"),
 275                OPT_STRING(0, "match",       &pattern, "pattern",
 276                           "only consider tags matching <pattern>"),
 277                OPT_END(),
 278        };
 279
 280        argc = parse_options(argc, argv, options, describe_usage, 0);
 281        if (max_candidates < 1)
 282                max_candidates = 1;
 283        else if (max_candidates > MAX_TAGS)
 284                max_candidates = MAX_TAGS;
 285
 286        save_commit_buffer = 0;
 287
 288        if (contains) {
 289                const char **args = xmalloc((6 + argc) * sizeof(char*));
 290                int i = 0;
 291                args[i++] = "name-rev";
 292                args[i++] = "--name-only";
 293                args[i++] = "--no-undefined";
 294                if (!all) {
 295                        args[i++] = "--tags";
 296                        if (pattern) {
 297                                char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 298                                sprintf(s, "--refs=refs/tags/%s", pattern);
 299                                args[i++] = s;
 300                        }
 301                }
 302                memcpy(args + i, argv, argc * sizeof(char*));
 303                args[i + argc] = NULL;
 304                return cmd_name_rev(i + argc, args, prefix);
 305        }
 306
 307        if (argc == 0) {
 308                describe("HEAD", 1);
 309        } else {
 310                while (argc-- > 0) {
 311                        describe(*argv++, argc == 0);
 312                }
 313        }
 314        return 0;
 315}