Andrew's git / gitweb.git / builtin/describe.c
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builtin / describe.con commit Sync with maint (3e7a5b4)
   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
  11#define SEEN            (1u<<0)
  12#define MAX_TAGS        (FLAG_BITS - 1)
  13
  14static const char * const describe_usage[] = {
  15        N_("git describe [options] <committish>*"),
  16        N_("git describe [options] --dirty"),
  17        NULL
  18};
  19
  20static int debug;       /* Display lots of verbose info */
  21static int all; /* Any valid ref can be used */
  22static int tags;        /* Allow lightweight tags */
  23static int longformat;
  24static int first_parent;
  25static int abbrev = -1; /* unspecified */
  26static int max_candidates = 10;
  27static struct hash_table names;
  28static int have_util;
  29static const char *pattern;
  30static int always;
  31static const char *dirty;
  32
  33/* diff-index command arguments to check if working tree is dirty. */
  34static const char *diff_index_args[] = {
  35        "diff-index", "--quiet", "HEAD", "--", NULL
  36};
  37
  38
  39struct commit_name {
  40        struct commit_name *next;
  41        unsigned char peeled[20];
  42        struct tag *tag;
  43        unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  44        unsigned name_checked:1;
  45        unsigned char sha1[20];
  46        char *path;
  47};
  48static const char *prio_names[] = {
  49        "head", "lightweight", "annotated",
  50};
  51
  52static inline unsigned int hash_sha1(const unsigned char *sha1)
  53{
  54        unsigned int hash;
  55        memcpy(&hash, sha1, sizeof(hash));
  56        return hash;
  57}
  58
  59static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  60{
  61        struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  62        while (n && !!hashcmp(peeled, n->peeled))
  63                n = n->next;
  64        return n;
  65}
  66
  67static int set_util(void *chain, void *data)
  68{
  69        struct commit_name *n;
  70        for (n = chain; n; n = n->next) {
  71                struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
  72                if (c)
  73                        c->util = n;
  74        }
  75        return 0;
  76}
  77
  78static int replace_name(struct commit_name *e,
  79                               int prio,
  80                               const unsigned char *sha1,
  81                               struct tag **tag)
  82{
  83        if (!e || e->prio < prio)
  84                return 1;
  85
  86        if (e->prio == 2 && prio == 2) {
  87                /* Multiple annotated tags point to the same commit.
  88                 * Select one to keep based upon their tagger date.
  89                 */
  90                struct tag *t;
  91
  92                if (!e->tag) {
  93                        t = lookup_tag(e->sha1);
  94                        if (!t || parse_tag(t))
  95                                return 1;
  96                        e->tag = t;
  97                }
  98
  99                t = lookup_tag(sha1);
 100                if (!t || parse_tag(t))
 101                        return 0;
 102                *tag = t;
 103
 104                if (e->tag->date < t->date)
 105                        return 1;
 106        }
 107
 108        return 0;
 109}
 110
 111static void add_to_known_names(const char *path,
 112                               const unsigned char *peeled,
 113                               int prio,
 114                               const unsigned char *sha1)
 115{
 116        struct commit_name *e = find_commit_name(peeled);
 117        struct tag *tag = NULL;
 118        if (replace_name(e, prio, sha1, &tag)) {
 119                if (!e) {
 120                        void **pos;
 121                        e = xmalloc(sizeof(struct commit_name));
 122                        hashcpy(e->peeled, peeled);
 123                        pos = insert_hash(hash_sha1(peeled), e, &names);
 124                        if (pos) {
 125                                e->next = *pos;
 126                                *pos = e;
 127                        } else {
 128                                e->next = NULL;
 129                        }
 130                        e->path = NULL;
 131                }
 132                e->tag = tag;
 133                e->prio = prio;
 134                e->name_checked = 0;
 135                hashcpy(e->sha1, sha1);
 136                free(e->path);
 137                e->path = xstrdup(path);
 138        }
 139}
 140
 141static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 142{
 143        int is_tag = !prefixcmp(path, "refs/tags/");
 144        unsigned char peeled[20];
 145        int is_annotated, prio;
 146
 147        /* Reject anything outside refs/tags/ unless --all */
 148        if (!all && !is_tag)
 149                return 0;
 150
 151        /* Accept only tags that match the pattern, if given */
 152        if (pattern && (!is_tag || fnmatch(pattern, path + 10, 0)))
 153                return 0;
 154
 155        /* Is it annotated? */
 156        if (!peel_ref(path, peeled)) {
 157                is_annotated = !!hashcmp(sha1, peeled);
 158        } else {
 159                hashcpy(peeled, sha1);
 160                is_annotated = 0;
 161        }
 162
 163        /*
 164         * By default, we only use annotated tags, but with --tags
 165         * we fall back to lightweight ones (even without --tags,
 166         * we still remember lightweight ones, only to give hints
 167         * in an error message).  --all allows any refs to be used.
 168         */
 169        if (is_annotated)
 170                prio = 2;
 171        else if (is_tag)
 172                prio = 1;
 173        else
 174                prio = 0;
 175
 176        add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 177        return 0;
 178}
 179
 180struct possible_tag {
 181        struct commit_name *name;
 182        int depth;
 183        int found_order;
 184        unsigned flag_within;
 185};
 186
 187static int compare_pt(const void *a_, const void *b_)
 188{
 189        struct possible_tag *a = (struct possible_tag *)a_;
 190        struct possible_tag *b = (struct possible_tag *)b_;
 191        if (a->depth != b->depth)
 192                return a->depth - b->depth;
 193        if (a->found_order != b->found_order)
 194                return a->found_order - b->found_order;
 195        return 0;
 196}
 197
 198static unsigned long finish_depth_computation(
 199        struct commit_list **list,
 200        struct possible_tag *best)
 201{
 202        unsigned long seen_commits = 0;
 203        while (*list) {
 204                struct commit *c = pop_commit(list);
 205                struct commit_list *parents = c->parents;
 206                seen_commits++;
 207                if (c->object.flags & best->flag_within) {
 208                        struct commit_list *a = *list;
 209                        while (a) {
 210                                struct commit *i = a->item;
 211                                if (!(i->object.flags & best->flag_within))
 212                                        break;
 213                                a = a->next;
 214                        }
 215                        if (!a)
 216                                break;
 217                } else
 218                        best->depth++;
 219                while (parents) {
 220                        struct commit *p = parents->item;
 221                        parse_commit(p);
 222                        if (!(p->object.flags & SEEN))
 223                                commit_list_insert_by_date(p, list);
 224                        p->object.flags |= c->object.flags;
 225                        parents = parents->next;
 226                }
 227        }
 228        return seen_commits;
 229}
 230
 231static void display_name(struct commit_name *n)
 232{
 233        if (n->prio == 2 && !n->tag) {
 234                n->tag = lookup_tag(n->sha1);
 235                if (!n->tag || parse_tag(n->tag))
 236                        die(_("annotated tag %s not available"), n->path);
 237        }
 238        if (n->tag && !n->name_checked) {
 239                if (!n->tag->tag)
 240                        die(_("annotated tag %s has no embedded name"), n->path);
 241                if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 242                        warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 243                n->name_checked = 1;
 244        }
 245
 246        if (n->tag)
 247                printf("%s", n->tag->tag);
 248        else
 249                printf("%s", n->path);
 250}
 251
 252static void show_suffix(int depth, const unsigned char *sha1)
 253{
 254        printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 255}
 256
 257static void describe(const char *arg, int last_one)
 258{
 259        unsigned char sha1[20];
 260        struct commit *cmit, *gave_up_on = NULL;
 261        struct commit_list *list;
 262        struct commit_name *n;
 263        struct possible_tag all_matches[MAX_TAGS];
 264        unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 265        unsigned long seen_commits = 0;
 266        unsigned int unannotated_cnt = 0;
 267
 268        if (get_sha1(arg, sha1))
 269                die(_("Not a valid object name %s"), arg);
 270        cmit = lookup_commit_reference(sha1);
 271        if (!cmit)
 272                die(_("%s is not a valid '%s' object"), arg, commit_type);
 273
 274        n = find_commit_name(cmit->object.sha1);
 275        if (n && (tags || all || n->prio == 2)) {
 276                /*
 277                 * Exact match to an existing ref.
 278                 */
 279                display_name(n);
 280                if (longformat)
 281                        show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 282                if (dirty)
 283                        printf("%s", dirty);
 284                printf("\n");
 285                return;
 286        }
 287
 288        if (!max_candidates)
 289                die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 290        if (debug)
 291                fprintf(stderr, _("searching to describe %s\n"), arg);
 292
 293        if (!have_util) {
 294                for_each_hash(&names, set_util, NULL);
 295                have_util = 1;
 296        }
 297
 298        list = NULL;
 299        cmit->object.flags = SEEN;
 300        commit_list_insert(cmit, &list);
 301        while (list) {
 302                struct commit *c = pop_commit(&list);
 303                struct commit_list *parents = c->parents;
 304                seen_commits++;
 305                n = c->util;
 306                if (n) {
 307                        if (!tags && !all && n->prio < 2) {
 308                                unannotated_cnt++;
 309                        } else if (match_cnt < max_candidates) {
 310                                struct possible_tag *t = &all_matches[match_cnt++];
 311                                t->name = n;
 312                                t->depth = seen_commits - 1;
 313                                t->flag_within = 1u << match_cnt;
 314                                t->found_order = match_cnt;
 315                                c->object.flags |= t->flag_within;
 316                                if (n->prio == 2)
 317                                        annotated_cnt++;
 318                        }
 319                        else {
 320                                gave_up_on = c;
 321                                break;
 322                        }
 323                }
 324                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 325                        struct possible_tag *t = &all_matches[cur_match];
 326                        if (!(c->object.flags & t->flag_within))
 327                                t->depth++;
 328                }
 329                if (annotated_cnt && !list) {
 330                        if (debug)
 331                                fprintf(stderr, _("finished search at %s\n"),
 332                                        sha1_to_hex(c->object.sha1));
 333                        break;
 334                }
 335                while (parents) {
 336                        struct commit *p = parents->item;
 337                        parse_commit(p);
 338                        if (!(p->object.flags & SEEN))
 339                                commit_list_insert_by_date(p, &list);
 340                        p->object.flags |= c->object.flags;
 341                        parents = parents->next;
 342
 343                        if (first_parent)
 344                                break;
 345                }
 346        }
 347
 348        if (!match_cnt) {
 349                const unsigned char *sha1 = cmit->object.sha1;
 350                if (always) {
 351                        printf("%s", find_unique_abbrev(sha1, abbrev));
 352                        if (dirty)
 353                                printf("%s", dirty);
 354                        printf("\n");
 355                        return;
 356                }
 357                if (unannotated_cnt)
 358                        die(_("No annotated tags can describe '%s'.\n"
 359                            "However, there were unannotated tags: try --tags."),
 360                            sha1_to_hex(sha1));
 361                else
 362                        die(_("No tags can describe '%s'.\n"
 363                            "Try --always, or create some tags."),
 364                            sha1_to_hex(sha1));
 365        }
 366
 367        qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 368
 369        if (gave_up_on) {
 370                commit_list_insert_by_date(gave_up_on, &list);
 371                seen_commits--;
 372        }
 373        seen_commits += finish_depth_computation(&list, &all_matches[0]);
 374        free_commit_list(list);
 375
 376        if (debug) {
 377                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 378                        struct possible_tag *t = &all_matches[cur_match];
 379                        fprintf(stderr, " %-11s %8d %s\n",
 380                                prio_names[t->name->prio],
 381                                t->depth, t->name->path);
 382                }
 383                fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 384                if (gave_up_on) {
 385                        fprintf(stderr,
 386                                _("more than %i tags found; listed %i most recent\n"
 387                                "gave up search at %s\n"),
 388                                max_candidates, max_candidates,
 389                                sha1_to_hex(gave_up_on->object.sha1));
 390                }
 391        }
 392
 393        display_name(all_matches[0].name);
 394        if (abbrev)
 395                show_suffix(all_matches[0].depth, cmit->object.sha1);
 396        if (dirty)
 397                printf("%s", dirty);
 398        printf("\n");
 399
 400        if (!last_one)
 401                clear_commit_marks(cmit, -1);
 402}
 403
 404int cmd_describe(int argc, const char **argv, const char *prefix)
 405{
 406        int contains = 0;
 407        struct option options[] = {
 408                OPT_BOOLEAN(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 409                OPT_BOOLEAN(0, "debug",      &debug, N_("debug search strategy on stderr")),
 410                OPT_BOOLEAN(0, "all",        &all, N_("use any ref")),
 411                OPT_BOOLEAN(0, "tags",       &tags, N_("use any tag, even unannotated")),
 412                OPT_BOOLEAN(0, "long",       &longformat, N_("always use long format")),
 413                OPT_BOOLEAN(0, "first-parent", &first_parent, N_("only follow first parent")),
 414                OPT__ABBREV(&abbrev),
 415                OPT_SET_INT(0, "exact-match", &max_candidates,
 416                            N_("only output exact matches"), 0),
 417                OPT_INTEGER(0, "candidates", &max_candidates,
 418                            N_("consider <n> most recent tags (default: 10)")),
 419                OPT_STRING(0, "match",       &pattern, N_("pattern"),
 420                           N_("only consider tags matching <pattern>")),
 421                OPT_BOOLEAN(0, "always",     &always,
 422                           N_("show abbreviated commit object as fallback")),
 423                {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 424                           N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 425                 PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 426                OPT_END(),
 427        };
 428
 429        git_config(git_default_config, NULL);
 430        argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 431        if (abbrev < 0)
 432                abbrev = DEFAULT_ABBREV;
 433
 434        if (max_candidates < 0)
 435                max_candidates = 0;
 436        else if (max_candidates > MAX_TAGS)
 437                max_candidates = MAX_TAGS;
 438
 439        save_commit_buffer = 0;
 440
 441        if (longformat && abbrev == 0)
 442                die(_("--long is incompatible with --abbrev=0"));
 443
 444        if (contains) {
 445                const char **args = xmalloc((7 + argc) * sizeof(char *));
 446                int i = 0;
 447                args[i++] = "name-rev";
 448                args[i++] = "--name-only";
 449                args[i++] = "--no-undefined";
 450                if (always)
 451                        args[i++] = "--always";
 452                if (!all) {
 453                        args[i++] = "--tags";
 454                        if (pattern) {
 455                                char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 456                                sprintf(s, "--refs=refs/tags/%s", pattern);
 457                                args[i++] = s;
 458                        }
 459                }
 460                memcpy(args + i, argv, argc * sizeof(char *));
 461                args[i + argc] = NULL;
 462                return cmd_name_rev(i + argc, args, 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}