builtin-describe.con commit Merge branch 'jc/maint-1.6.0-read-tree-overlay' into maint (0e1aa2f)
   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; /* Any valid ref can be used */
  19static int tags;        /* Allow lightweight tags */
  20static int longformat;
  21static int abbrev = DEFAULT_ABBREV;
  22static int max_candidates = 10;
  23static const char *pattern;
  24static int always;
  25
  26struct commit_name {
  27        struct tag *tag;
  28        int prio; /* annotated tag = 2, tag = 1, head = 0 */
  29        unsigned char sha1[20];
  30        char path[FLEX_ARRAY]; /* more */
  31};
  32static const char *prio_names[] = {
  33        "head", "lightweight", "annotated",
  34};
  35
  36static void add_to_known_names(const char *path,
  37                               struct commit *commit,
  38                               int prio,
  39                               const unsigned char *sha1)
  40{
  41        struct commit_name *e = commit->util;
  42        if (!e || e->prio < prio) {
  43                size_t len = strlen(path)+1;
  44                free(e);
  45                e = xmalloc(sizeof(struct commit_name) + len);
  46                e->tag = NULL;
  47                e->prio = prio;
  48                hashcpy(e->sha1, sha1);
  49                memcpy(e->path, path, len);
  50                commit->util = e;
  51        }
  52}
  53
  54static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  55{
  56        int might_be_tag = !prefixcmp(path, "refs/tags/");
  57        struct commit *commit;
  58        struct object *object;
  59        unsigned char peeled[20];
  60        int is_tag, prio;
  61
  62        if (!all && !might_be_tag)
  63                return 0;
  64
  65        if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
  66                commit = lookup_commit_reference_gently(peeled, 1);
  67                if (!commit)
  68                        return 0;
  69                is_tag = !!hashcmp(sha1, commit->object.sha1);
  70        } else {
  71                commit = lookup_commit_reference_gently(sha1, 1);
  72                object = parse_object(sha1);
  73                if (!commit || !object)
  74                        return 0;
  75                is_tag = object->type == OBJ_TAG;
  76        }
  77
  78        /* If --all, then any refs are used.
  79         * If --tags, then any tags are used.
  80         * Otherwise only annotated tags are used.
  81         */
  82        if (might_be_tag) {
  83                if (is_tag)
  84                        prio = 2;
  85                else
  86                        prio = 1;
  87
  88                if (pattern && fnmatch(pattern, path + 10, 0))
  89                        prio = 0;
  90        }
  91        else
  92                prio = 0;
  93
  94        if (!all) {
  95                if (!prio)
  96                        return 0;
  97                if (!tags && prio < 2)
  98                        return 0;
  99        }
 100        add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 101        return 0;
 102}
 103
 104struct possible_tag {
 105        struct commit_name *name;
 106        int depth;
 107        int found_order;
 108        unsigned flag_within;
 109};
 110
 111static int compare_pt(const void *a_, const void *b_)
 112{
 113        struct possible_tag *a = (struct possible_tag *)a_;
 114        struct possible_tag *b = (struct possible_tag *)b_;
 115        if (a->depth != b->depth)
 116                return a->depth - b->depth;
 117        if (a->found_order != b->found_order)
 118                return a->found_order - b->found_order;
 119        return 0;
 120}
 121
 122static unsigned long finish_depth_computation(
 123        struct commit_list **list,
 124        struct possible_tag *best)
 125{
 126        unsigned long seen_commits = 0;
 127        while (*list) {
 128                struct commit *c = pop_commit(list);
 129                struct commit_list *parents = c->parents;
 130                seen_commits++;
 131                if (c->object.flags & best->flag_within) {
 132                        struct commit_list *a = *list;
 133                        while (a) {
 134                                struct commit *i = a->item;
 135                                if (!(i->object.flags & best->flag_within))
 136                                        break;
 137                                a = a->next;
 138                        }
 139                        if (!a)
 140                                break;
 141                } else
 142                        best->depth++;
 143                while (parents) {
 144                        struct commit *p = parents->item;
 145                        parse_commit(p);
 146                        if (!(p->object.flags & SEEN))
 147                                insert_by_date(p, list);
 148                        p->object.flags |= c->object.flags;
 149                        parents = parents->next;
 150                }
 151        }
 152        return seen_commits;
 153}
 154
 155static void display_name(struct commit_name *n)
 156{
 157        if (n->prio == 2 && !n->tag) {
 158                n->tag = lookup_tag(n->sha1);
 159                if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
 160                        die("annotated tag %s not available", n->path);
 161                if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 162                        warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 163        }
 164
 165        if (n->tag)
 166                printf("%s", n->tag->tag);
 167        else
 168                printf("%s", n->path);
 169}
 170
 171static void show_suffix(int depth, const unsigned char *sha1)
 172{
 173        printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 174}
 175
 176static void describe(const char *arg, int last_one)
 177{
 178        unsigned char sha1[20];
 179        struct commit *cmit, *gave_up_on = NULL;
 180        struct commit_list *list;
 181        static int initialized = 0;
 182        struct commit_name *n;
 183        struct possible_tag all_matches[MAX_TAGS];
 184        unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 185        unsigned long seen_commits = 0;
 186
 187        if (get_sha1(arg, sha1))
 188                die("Not a valid object name %s", arg);
 189        cmit = lookup_commit_reference(sha1);
 190        if (!cmit)
 191                die("%s is not a valid '%s' object", arg, commit_type);
 192
 193        if (!initialized) {
 194                initialized = 1;
 195                for_each_ref(get_name, NULL);
 196        }
 197
 198        n = cmit->util;
 199        if (n) {
 200                /*
 201                 * Exact match to an existing ref.
 202                 */
 203                display_name(n);
 204                if (longformat)
 205                        show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 206                printf("\n");
 207                return;
 208        }
 209
 210        if (!max_candidates)
 211                die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 212        if (debug)
 213                fprintf(stderr, "searching to describe %s\n", arg);
 214
 215        list = NULL;
 216        cmit->object.flags = SEEN;
 217        commit_list_insert(cmit, &list);
 218        while (list) {
 219                struct commit *c = pop_commit(&list);
 220                struct commit_list *parents = c->parents;
 221                seen_commits++;
 222                n = c->util;
 223                if (n) {
 224                        if (match_cnt < max_candidates) {
 225                                struct possible_tag *t = &all_matches[match_cnt++];
 226                                t->name = n;
 227                                t->depth = seen_commits - 1;
 228                                t->flag_within = 1u << match_cnt;
 229                                t->found_order = match_cnt;
 230                                c->object.flags |= t->flag_within;
 231                                if (n->prio == 2)
 232                                        annotated_cnt++;
 233                        }
 234                        else {
 235                                gave_up_on = c;
 236                                break;
 237                        }
 238                }
 239                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 240                        struct possible_tag *t = &all_matches[cur_match];
 241                        if (!(c->object.flags & t->flag_within))
 242                                t->depth++;
 243                }
 244                if (annotated_cnt && !list) {
 245                        if (debug)
 246                                fprintf(stderr, "finished search at %s\n",
 247                                        sha1_to_hex(c->object.sha1));
 248                        break;
 249                }
 250                while (parents) {
 251                        struct commit *p = parents->item;
 252                        parse_commit(p);
 253                        if (!(p->object.flags & SEEN))
 254                                insert_by_date(p, &list);
 255                        p->object.flags |= c->object.flags;
 256                        parents = parents->next;
 257                }
 258        }
 259
 260        if (!match_cnt) {
 261                const unsigned char *sha1 = cmit->object.sha1;
 262                if (always) {
 263                        printf("%s\n", find_unique_abbrev(sha1, abbrev));
 264                        return;
 265                }
 266                die("cannot describe '%s'", sha1_to_hex(sha1));
 267        }
 268
 269        qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 270
 271        if (gave_up_on) {
 272                insert_by_date(gave_up_on, &list);
 273                seen_commits--;
 274        }
 275        seen_commits += finish_depth_computation(&list, &all_matches[0]);
 276        free_commit_list(list);
 277
 278        if (debug) {
 279                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 280                        struct possible_tag *t = &all_matches[cur_match];
 281                        fprintf(stderr, " %-11s %8d %s\n",
 282                                prio_names[t->name->prio],
 283                                t->depth, t->name->path);
 284                }
 285                fprintf(stderr, "traversed %lu commits\n", seen_commits);
 286                if (gave_up_on) {
 287                        fprintf(stderr,
 288                                "more than %i tags found; listed %i most recent\n"
 289                                "gave up search at %s\n",
 290                                max_candidates, max_candidates,
 291                                sha1_to_hex(gave_up_on->object.sha1));
 292                }
 293        }
 294
 295        display_name(all_matches[0].name);
 296        if (abbrev)
 297                show_suffix(all_matches[0].depth, cmit->object.sha1);
 298        printf("\n");
 299
 300        if (!last_one)
 301                clear_commit_marks(cmit, -1);
 302}
 303
 304int cmd_describe(int argc, const char **argv, const char *prefix)
 305{
 306        int contains = 0;
 307        struct option options[] = {
 308                OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 309                OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 310                OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 311                OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 312                OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 313                OPT__ABBREV(&abbrev),
 314                OPT_SET_INT(0, "exact-match", &max_candidates,
 315                            "only output exact matches", 0),
 316                OPT_INTEGER(0, "candidates", &max_candidates,
 317                            "consider <n> most recent tags (default: 10)"),
 318                OPT_STRING(0, "match",       &pattern, "pattern",
 319                           "only consider tags matching <pattern>"),
 320                OPT_BOOLEAN(0, "always",     &always,
 321                           "show abbreviated commit object as fallback"),
 322                OPT_END(),
 323        };
 324
 325        argc = parse_options(argc, argv, options, describe_usage, 0);
 326        if (max_candidates < 0)
 327                max_candidates = 0;
 328        else if (max_candidates > MAX_TAGS)
 329                max_candidates = MAX_TAGS;
 330
 331        save_commit_buffer = 0;
 332
 333        if (longformat && abbrev == 0)
 334                die("--long is incompatible with --abbrev=0");
 335
 336        if (contains) {
 337                const char **args = xmalloc((7 + argc) * sizeof(char*));
 338                int i = 0;
 339                args[i++] = "name-rev";
 340                args[i++] = "--name-only";
 341                args[i++] = "--no-undefined";
 342                if (always)
 343                        args[i++] = "--always";
 344                if (!all) {
 345                        args[i++] = "--tags";
 346                        if (pattern) {
 347                                char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 348                                sprintf(s, "--refs=refs/tags/%s", pattern);
 349                                args[i++] = s;
 350                        }
 351                }
 352                memcpy(args + i, argv, argc * sizeof(char*));
 353                args[i + argc] = NULL;
 354                return cmd_name_rev(i + argc, args, prefix);
 355        }
 356
 357        if (argc == 0) {
 358                describe("HEAD", 1);
 359        } else {
 360                while (argc-- > 0) {
 361                        describe(*argv++, argc == 0);
 362                }
 363        }
 364        return 0;
 365}