Andrew's git / gitweb.git / builtin/describe.c
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builtin / describe.con commit name-rev: differentiate between tags and commits they point at (118aa4a)
   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#include "diff.h"
   9#include "hash.h"
  10#include "argv-array.h"
  11
  12#define SEEN            (1u<<0)
  13#define MAX_TAGS        (FLAG_BITS - 1)
  14
  15static const char * const describe_usage[] = {
  16        N_("git describe [options] <committish>*"),
  17        N_("git describe [options] --dirty"),
  18        NULL
  19};
  20
  21static int debug;       /* Display lots of verbose info */
  22static int all; /* Any valid ref can be used */
  23static int tags;        /* Allow lightweight tags */
  24static int longformat;
  25static int first_parent;
  26static int abbrev = -1; /* unspecified */
  27static int max_candidates = 10;
  28static struct hash_table names;
  29static int have_util;
  30static const char *pattern;
  31static int always;
  32static const char *dirty;
  33
  34/* diff-index command arguments to check if working tree is dirty. */
  35static const char *diff_index_args[] = {
  36        "diff-index", "--quiet", "HEAD", "--", NULL
  37};
  38
  39
  40struct commit_name {
  41        struct commit_name *next;
  42        unsigned char peeled[20];
  43        struct tag *tag;
  44        unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  45        unsigned name_checked:1;
  46        unsigned char sha1[20];
  47        char *path;
  48};
  49static const char *prio_names[] = {
  50        "head", "lightweight", "annotated",
  51};
  52
  53static inline unsigned int hash_sha1(const unsigned char *sha1)
  54{
  55        unsigned int hash;
  56        memcpy(&hash, sha1, sizeof(hash));
  57        return hash;
  58}
  59
  60static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  61{
  62        struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  63        while (n && !!hashcmp(peeled, n->peeled))
  64                n = n->next;
  65        return n;
  66}
  67
  68static int set_util(void *chain, void *data)
  69{
  70        struct commit_name *n;
  71        for (n = chain; n; n = n->next) {
  72                struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
  73                if (c)
  74                        c->util = n;
  75        }
  76        return 0;
  77}
  78
  79static int replace_name(struct commit_name *e,
  80                               int prio,
  81                               const unsigned char *sha1,
  82                               struct tag **tag)
  83{
  84        if (!e || e->prio < prio)
  85                return 1;
  86
  87        if (e->prio == 2 && prio == 2) {
  88                /* Multiple annotated tags point to the same commit.
  89                 * Select one to keep based upon their tagger date.
  90                 */
  91                struct tag *t;
  92
  93                if (!e->tag) {
  94                        t = lookup_tag(e->sha1);
  95                        if (!t || parse_tag(t))
  96                                return 1;
  97                        e->tag = t;
  98                }
  99
 100                t = lookup_tag(sha1);
 101                if (!t || parse_tag(t))
 102                        return 0;
 103                *tag = t;
 104
 105                if (e->tag->date < t->date)
 106                        return 1;
 107        }
 108
 109        return 0;
 110}
 111
 112static void add_to_known_names(const char *path,
 113                               const unsigned char *peeled,
 114                               int prio,
 115                               const unsigned char *sha1)
 116{
 117        struct commit_name *e = find_commit_name(peeled);
 118        struct tag *tag = NULL;
 119        if (replace_name(e, prio, sha1, &tag)) {
 120                if (!e) {
 121                        void **pos;
 122                        e = xmalloc(sizeof(struct commit_name));
 123                        hashcpy(e->peeled, peeled);
 124                        pos = insert_hash(hash_sha1(peeled), e, &names);
 125                        if (pos) {
 126                                e->next = *pos;
 127                                *pos = e;
 128                        } else {
 129                                e->next = NULL;
 130                        }
 131                        e->path = NULL;
 132                }
 133                e->tag = tag;
 134                e->prio = prio;
 135                e->name_checked = 0;
 136                hashcpy(e->sha1, sha1);
 137                free(e->path);
 138                e->path = xstrdup(path);
 139        }
 140}
 141
 142static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 143{
 144        int is_tag = !prefixcmp(path, "refs/tags/");
 145        unsigned char peeled[20];
 146        int is_annotated, prio;
 147
 148        /* Reject anything outside refs/tags/ unless --all */
 149        if (!all && !is_tag)
 150                return 0;
 151
 152        /* Accept only tags that match the pattern, if given */
 153        if (pattern && (!is_tag || fnmatch(pattern, path + 10, 0)))
 154                return 0;
 155
 156        /* Is it annotated? */
 157        if (!peel_ref(path, peeled)) {
 158                is_annotated = !!hashcmp(sha1, peeled);
 159        } else {
 160                hashcpy(peeled, sha1);
 161                is_annotated = 0;
 162        }
 163
 164        /*
 165         * By default, we only use annotated tags, but with --tags
 166         * we fall back to lightweight ones (even without --tags,
 167         * we still remember lightweight ones, only to give hints
 168         * in an error message).  --all allows any refs to be used.
 169         */
 170        if (is_annotated)
 171                prio = 2;
 172        else if (is_tag)
 173                prio = 1;
 174        else
 175                prio = 0;
 176
 177        add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 178        return 0;
 179}
 180
 181struct possible_tag {
 182        struct commit_name *name;
 183        int depth;
 184        int found_order;
 185        unsigned flag_within;
 186};
 187
 188static int compare_pt(const void *a_, const void *b_)
 189{
 190        struct possible_tag *a = (struct possible_tag *)a_;
 191        struct possible_tag *b = (struct possible_tag *)b_;
 192        if (a->depth != b->depth)
 193                return a->depth - b->depth;
 194        if (a->found_order != b->found_order)
 195                return a->found_order - b->found_order;
 196        return 0;
 197}
 198
 199static unsigned long finish_depth_computation(
 200        struct commit_list **list,
 201        struct possible_tag *best)
 202{
 203        unsigned long seen_commits = 0;
 204        while (*list) {
 205                struct commit *c = pop_commit(list);
 206                struct commit_list *parents = c->parents;
 207                seen_commits++;
 208                if (c->object.flags & best->flag_within) {
 209                        struct commit_list *a = *list;
 210                        while (a) {
 211                                struct commit *i = a->item;
 212                                if (!(i->object.flags & best->flag_within))
 213                                        break;
 214                                a = a->next;
 215                        }
 216                        if (!a)
 217                                break;
 218                } else
 219                        best->depth++;
 220                while (parents) {
 221                        struct commit *p = parents->item;
 222                        parse_commit(p);
 223                        if (!(p->object.flags & SEEN))
 224                                commit_list_insert_by_date(p, list);
 225                        p->object.flags |= c->object.flags;
 226                        parents = parents->next;
 227                }
 228        }
 229        return seen_commits;
 230}
 231
 232static void display_name(struct commit_name *n)
 233{
 234        if (n->prio == 2 && !n->tag) {
 235                n->tag = lookup_tag(n->sha1);
 236                if (!n->tag || parse_tag(n->tag))
 237                        die(_("annotated tag %s not available"), n->path);
 238        }
 239        if (n->tag && !n->name_checked) {
 240                if (!n->tag->tag)
 241                        die(_("annotated tag %s has no embedded name"), n->path);
 242                if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 243                        warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 244                n->name_checked = 1;
 245        }
 246
 247        if (n->tag)
 248                printf("%s", n->tag->tag);
 249        else
 250                printf("%s", n->path);
 251}
 252
 253static void show_suffix(int depth, const unsigned char *sha1)
 254{
 255        printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 256}
 257
 258static void describe(const char *arg, int last_one)
 259{
 260        unsigned char sha1[20];
 261        struct commit *cmit, *gave_up_on = NULL;
 262        struct commit_list *list;
 263        struct commit_name *n;
 264        struct possible_tag all_matches[MAX_TAGS];
 265        unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 266        unsigned long seen_commits = 0;
 267        unsigned int unannotated_cnt = 0;
 268
 269        if (get_sha1(arg, sha1))
 270                die(_("Not a valid object name %s"), arg);
 271        cmit = lookup_commit_reference(sha1);
 272        if (!cmit)
 273                die(_("%s is not a valid '%s' object"), arg, commit_type);
 274
 275        n = find_commit_name(cmit->object.sha1);
 276        if (n && (tags || all || n->prio == 2)) {
 277                /*
 278                 * Exact match to an existing ref.
 279                 */
 280                display_name(n);
 281                if (longformat)
 282                        show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 283                if (dirty)
 284                        printf("%s", dirty);
 285                printf("\n");
 286                return;
 287        }
 288
 289        if (!max_candidates)
 290                die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 291        if (debug)
 292                fprintf(stderr, _("searching to describe %s\n"), arg);
 293
 294        if (!have_util) {
 295                for_each_hash(&names, set_util, NULL);
 296                have_util = 1;
 297        }
 298
 299        list = NULL;
 300        cmit->object.flags = SEEN;
 301        commit_list_insert(cmit, &list);
 302        while (list) {
 303                struct commit *c = pop_commit(&list);
 304                struct commit_list *parents = c->parents;
 305                seen_commits++;
 306                n = c->util;
 307                if (n) {
 308                        if (!tags && !all && n->prio < 2) {
 309                                unannotated_cnt++;
 310                        } else if (match_cnt < max_candidates) {
 311                                struct possible_tag *t = &all_matches[match_cnt++];
 312                                t->name = n;
 313                                t->depth = seen_commits - 1;
 314                                t->flag_within = 1u << match_cnt;
 315                                t->found_order = match_cnt;
 316                                c->object.flags |= t->flag_within;
 317                                if (n->prio == 2)
 318                                        annotated_cnt++;
 319                        }
 320                        else {
 321                                gave_up_on = c;
 322                                break;
 323                        }
 324                }
 325                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 326                        struct possible_tag *t = &all_matches[cur_match];
 327                        if (!(c->object.flags & t->flag_within))
 328                                t->depth++;
 329                }
 330                if (annotated_cnt && !list) {
 331                        if (debug)
 332                                fprintf(stderr, _("finished search at %s\n"),
 333                                        sha1_to_hex(c->object.sha1));
 334                        break;
 335                }
 336                while (parents) {
 337                        struct commit *p = parents->item;
 338                        parse_commit(p);
 339                        if (!(p->object.flags & SEEN))
 340                                commit_list_insert_by_date(p, &list);
 341                        p->object.flags |= c->object.flags;
 342                        parents = parents->next;
 343
 344                        if (first_parent)
 345                                break;
 346                }
 347        }
 348
 349        if (!match_cnt) {
 350                const unsigned char *sha1 = cmit->object.sha1;
 351                if (always) {
 352                        printf("%s", find_unique_abbrev(sha1, abbrev));
 353                        if (dirty)
 354                                printf("%s", dirty);
 355                        printf("\n");
 356                        return;
 357                }
 358                if (unannotated_cnt)
 359                        die(_("No annotated tags can describe '%s'.\n"
 360                            "However, there were unannotated tags: try --tags."),
 361                            sha1_to_hex(sha1));
 362                else
 363                        die(_("No tags can describe '%s'.\n"
 364                            "Try --always, or create some tags."),
 365                            sha1_to_hex(sha1));
 366        }
 367
 368        qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 369
 370        if (gave_up_on) {
 371                commit_list_insert_by_date(gave_up_on, &list);
 372                seen_commits--;
 373        }
 374        seen_commits += finish_depth_computation(&list, &all_matches[0]);
 375        free_commit_list(list);
 376
 377        if (debug) {
 378                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 379                        struct possible_tag *t = &all_matches[cur_match];
 380                        fprintf(stderr, " %-11s %8d %s\n",
 381                                prio_names[t->name->prio],
 382                                t->depth, t->name->path);
 383                }
 384                fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 385                if (gave_up_on) {
 386                        fprintf(stderr,
 387                                _("more than %i tags found; listed %i most recent\n"
 388                                "gave up search at %s\n"),
 389                                max_candidates, max_candidates,
 390                                sha1_to_hex(gave_up_on->object.sha1));
 391                }
 392        }
 393
 394        display_name(all_matches[0].name);
 395        if (abbrev)
 396                show_suffix(all_matches[0].depth, cmit->object.sha1);
 397        if (dirty)
 398                printf("%s", dirty);
 399        printf("\n");
 400
 401        if (!last_one)
 402                clear_commit_marks(cmit, -1);
 403}
 404
 405int cmd_describe(int argc, const char **argv, const char *prefix)
 406{
 407        int contains = 0;
 408        struct option options[] = {
 409                OPT_BOOLEAN(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 410                OPT_BOOLEAN(0, "debug",      &debug, N_("debug search strategy on stderr")),
 411                OPT_BOOLEAN(0, "all",        &all, N_("use any ref")),
 412                OPT_BOOLEAN(0, "tags",       &tags, N_("use any tag, even unannotated")),
 413                OPT_BOOLEAN(0, "long",       &longformat, N_("always use long format")),
 414                OPT_BOOLEAN(0, "first-parent", &first_parent, N_("only follow first parent")),
 415                OPT__ABBREV(&abbrev),
 416                OPT_SET_INT(0, "exact-match", &max_candidates,
 417                            N_("only output exact matches"), 0),
 418                OPT_INTEGER(0, "candidates", &max_candidates,
 419                            N_("consider <n> most recent tags (default: 10)")),
 420                OPT_STRING(0, "match",       &pattern, N_("pattern"),
 421                           N_("only consider tags matching <pattern>")),
 422                OPT_BOOLEAN(0, "always",     &always,
 423                           N_("show abbreviated commit object as fallback")),
 424                {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 425                           N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 426                 PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 427                OPT_END(),
 428        };
 429
 430        git_config(git_default_config, NULL);
 431        argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 432        if (abbrev < 0)
 433                abbrev = DEFAULT_ABBREV;
 434
 435        if (max_candidates < 0)
 436                max_candidates = 0;
 437        else if (max_candidates > MAX_TAGS)
 438                max_candidates = MAX_TAGS;
 439
 440        save_commit_buffer = 0;
 441
 442        if (longformat && abbrev == 0)
 443                die(_("--long is incompatible with --abbrev=0"));
 444
 445        if (contains) {
 446                struct argv_array args;
 447
 448                argv_array_init(&args);
 449                argv_array_pushl(&args, "name-rev", "--name-only", "--no-undefined",
 450                                 NULL);
 451                if (always)
 452                        argv_array_push(&args, "--always");
 453                if (!all) {
 454                        argv_array_push(&args, "--tags");
 455                        if (pattern)
 456                                argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
 457                }
 458                while (*argv) {
 459                        argv_array_push(&args, *argv);
 460                        argv++;
 461                }
 462                return cmd_name_rev(args.argc, args.argv, prefix);
 463        }
 464
 465        init_hash(&names);
 466        for_each_rawref(get_name, NULL);
 467        if (!names.nr && !always)
 468                die(_("No names found, cannot describe anything."));
 469
 470        if (argc == 0) {
 471                if (dirty) {
 472                        static struct lock_file index_lock;
 473                        int fd;
 474
 475                        read_cache_preload(NULL);
 476                        refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 477                                      NULL, NULL, NULL);
 478                        fd = hold_locked_index(&index_lock, 0);
 479                        if (0 <= fd)
 480                                update_index_if_able(&the_index, &index_lock);
 481
 482                        if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 483                                            diff_index_args, prefix))
 484                                dirty = NULL;
 485                }
 486                describe("HEAD", 1);
 487        } else if (dirty) {
 488                die(_("--dirty is incompatible with committishes"));
 489        } else {
 490                while (argc-- > 0) {
 491                        describe(*argv++, argc == 0);
 492                }
 493        }
 494        return 0;
 495}