7075548e6b4d5e1c3c899e033339202d46726358
   1#include "cache.h"
   2#include "refs.h"
   3#include "tag.h"
   4#include "commit.h"
   5#include "tree.h"
   6#include "blob.h"
   7#include "tree-walk.h"
   8#include "diff.h"
   9#include "revision.h"
  10#include "list-objects.h"
  11#include "builtin.h"
  12
  13/* bits #0-15 in revision.h */
  14
  15#define COUNTED         (1u<<16)
  16
  17static const char rev_list_usage[] =
  18"git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
  19"  limiting output:\n"
  20"    --max-count=nr\n"
  21"    --max-age=epoch\n"
  22"    --min-age=epoch\n"
  23"    --sparse\n"
  24"    --no-merges\n"
  25"    --remove-empty\n"
  26"    --all\n"
  27"    --stdin\n"
  28"  ordering output:\n"
  29"    --topo-order\n"
  30"    --date-order\n"
  31"  formatting output:\n"
  32"    --parents\n"
  33"    --objects | --objects-edge\n"
  34"    --unpacked\n"
  35"    --header | --pretty\n"
  36"    --abbrev=nr | --no-abbrev\n"
  37"    --abbrev-commit\n"
  38"  special purpose:\n"
  39"    --bisect\n"
  40"    --bisect-vars"
  41;
  42
  43static struct rev_info revs;
  44
  45static int bisect_list;
  46static int show_timestamp;
  47static int hdr_termination;
  48static const char *header_prefix;
  49
  50static void show_commit(struct commit *commit)
  51{
  52        if (show_timestamp)
  53                printf("%lu ", commit->date);
  54        if (header_prefix)
  55                fputs(header_prefix, stdout);
  56        if (commit->object.flags & BOUNDARY)
  57                putchar('-');
  58        else if (revs.left_right) {
  59                if (commit->object.flags & SYMMETRIC_LEFT)
  60                        putchar('<');
  61                else
  62                        putchar('>');
  63        }
  64        if (revs.abbrev_commit && revs.abbrev)
  65                fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
  66                      stdout);
  67        else
  68                fputs(sha1_to_hex(commit->object.sha1), stdout);
  69        if (revs.parents) {
  70                struct commit_list *parents = commit->parents;
  71                while (parents) {
  72                        struct object *o = &(parents->item->object);
  73                        parents = parents->next;
  74                        if (o->flags & TMP_MARK)
  75                                continue;
  76                        printf(" %s", sha1_to_hex(o->sha1));
  77                        o->flags |= TMP_MARK;
  78                }
  79                /* TMP_MARK is a general purpose flag that can
  80                 * be used locally, but the user should clean
  81                 * things up after it is done with them.
  82                 */
  83                for (parents = commit->parents;
  84                     parents;
  85                     parents = parents->next)
  86                        parents->item->object.flags &= ~TMP_MARK;
  87        }
  88        if (revs.commit_format == CMIT_FMT_ONELINE)
  89                putchar(' ');
  90        else
  91                putchar('\n');
  92
  93        if (revs.verbose_header) {
  94                static char pretty_header[16384];
  95                pretty_print_commit(revs.commit_format, commit, ~0,
  96                                    pretty_header, sizeof(pretty_header),
  97                                    revs.abbrev, NULL, NULL, revs.relative_date);
  98                printf("%s%c", pretty_header, hdr_termination);
  99        }
 100        fflush(stdout);
 101        if (commit->parents) {
 102                free_commit_list(commit->parents);
 103                commit->parents = NULL;
 104        }
 105        free(commit->buffer);
 106        commit->buffer = NULL;
 107}
 108
 109static void show_object(struct object_array_entry *p)
 110{
 111        /* An object with name "foo\n0000000..." can be used to
 112         * confuse downstream git-pack-objects very badly.
 113         */
 114        const char *ep = strchr(p->name, '\n');
 115        if (ep) {
 116                printf("%s %.*s\n", sha1_to_hex(p->item->sha1),
 117                       (int) (ep - p->name),
 118                       p->name);
 119        }
 120        else
 121                printf("%s %s\n", sha1_to_hex(p->item->sha1), p->name);
 122}
 123
 124static void show_edge(struct commit *commit)
 125{
 126        printf("-%s\n", sha1_to_hex(commit->object.sha1));
 127}
 128
 129/*
 130 * This is a truly stupid algorithm, but it's only
 131 * used for bisection, and we just don't care enough.
 132 *
 133 * We care just barely enough to avoid recursing for
 134 * non-merge entries.
 135 */
 136static int count_distance(struct commit_list *entry)
 137{
 138        int nr = 0;
 139
 140        while (entry) {
 141                struct commit *commit = entry->item;
 142                struct commit_list *p;
 143
 144                if (commit->object.flags & (UNINTERESTING | COUNTED))
 145                        break;
 146                if (!revs.prune_fn || (commit->object.flags & TREECHANGE))
 147                        nr++;
 148                commit->object.flags |= COUNTED;
 149                p = commit->parents;
 150                entry = p;
 151                if (p) {
 152                        p = p->next;
 153                        while (p) {
 154                                nr += count_distance(p);
 155                                p = p->next;
 156                        }
 157                }
 158        }
 159
 160        return nr;
 161}
 162
 163static void clear_distance(struct commit_list *list)
 164{
 165        while (list) {
 166                struct commit *commit = list->item;
 167                commit->object.flags &= ~COUNTED;
 168                list = list->next;
 169        }
 170}
 171
 172static struct commit_list *find_bisection(struct commit_list *list,
 173                                          int *reaches, int *all)
 174{
 175        int nr, closest;
 176        struct commit_list *p, *best;
 177
 178        nr = 0;
 179        p = list;
 180        while (p) {
 181                if (!revs.prune_fn || (p->item->object.flags & TREECHANGE))
 182                        nr++;
 183                p = p->next;
 184        }
 185        closest = -1;
 186        best = list;
 187        *all = nr;
 188
 189        for (p = list; p; p = p->next) {
 190                int distance, reach;
 191
 192                if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
 193                        continue;
 194
 195                distance = reach = count_distance(p);
 196                clear_distance(list);
 197                if (nr - distance < distance)
 198                        distance = nr - distance;
 199                if (distance > closest) {
 200                        best = p;
 201                        *reaches = reach;
 202                        closest = distance;
 203                }
 204        }
 205        if (best)
 206                best->next = NULL;
 207        return best;
 208}
 209
 210static inline int commit_interesting(struct commit_list *elem)
 211{
 212        unsigned flags = elem->item->object.flags;
 213        if (flags & UNINTERESTING)
 214                return 0;
 215        return (!revs.prune_fn || (flags & TREECHANGE));
 216}
 217
 218static inline int weight(struct commit_list *elem)
 219{
 220        return *((int*)(elem->item->util));
 221}
 222
 223static inline void weight_set(struct commit_list *elem, int weight)
 224{
 225        *((int*)(elem->item->util)) = weight;
 226}
 227
 228static int count_interesting_parents(struct commit_list *elem)
 229{
 230        int cnt = 0;
 231        if (!elem->item->parents)
 232                return cnt;
 233        for (elem = elem->item->parents; elem; elem = elem->next) {
 234                if (commit_interesting(elem))
 235                        cnt++;
 236        }
 237        return cnt;
 238}
 239
 240static inline int halfway(struct commit_list *p, int distance, int nr)
 241{
 242        /*
 243         * Don't short-cut something we are not going to return!
 244         */
 245        if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
 246                return 0;
 247
 248        /*
 249         * 2 and 3 are halfway of 5.
 250         * 3 is halfway of 6 but 2 and 4 are not.
 251         */
 252        distance *= 2;
 253        switch (distance - nr) {
 254        case -1: case 0: case 1:
 255                return 1;
 256        default:
 257                return 0;
 258        }
 259}
 260
 261static struct commit_list *find_bisection_2(struct commit_list *list,
 262                                            int *reaches, int *all)
 263{
 264        int n, nr, counted, distance;
 265        struct commit_list *p, *best;
 266        int *weights;
 267
 268        for (nr = 0, p = list; p; p = p->next) {
 269                if (commit_interesting(p))
 270                        nr++;
 271        }
 272        *all = nr;
 273        weights = xcalloc(nr, sizeof(int*));
 274        counted = 0;
 275
 276        for (n = 0, p = list; p; p = p->next) {
 277                if (!commit_interesting(p))
 278                        continue;
 279                if (commit_interesting(p)) {
 280                        /*
 281                         * positive weight is the number of interesting
 282                         * commits it can reach, including itself.
 283                         * weight = 0 means it has one parent and
 284                         * its distance is unknown.
 285                         * weight < 0 means it has more than one
 286                         * parent and its distance is unknown.
 287                         */
 288                        p->item->util = &weights[n++];
 289                        switch (count_interesting_parents(p)) {
 290                        case 0:
 291                                weight_set(p, 1);
 292                                counted++;
 293                                break;
 294                        case 1:
 295                                weight_set(p, 0);
 296                                break;
 297                        default:
 298                                weight_set(p, -1);
 299                                break;
 300                        }
 301                }
 302        }
 303
 304        /*
 305         * If you have only one parent in the resulting set
 306         * then you can reach one commit more than that parent
 307         * can reach.  So we do not have to run the expensive
 308         * count_distance() for single strand of pearls.
 309         *
 310         * However, if you have more than one parents, you cannot
 311         * just add their distance and one for yourself, since
 312         * they usually reach the same ancestor and you would
 313         * end up counting them twice that way.
 314         *
 315         * So we will first count distance of merges the usual
 316         * way, and then fill the blanks using cheaper algorithm.
 317         */
 318        for (p = list; p; p = p->next) {
 319                if (!commit_interesting(p))
 320                        continue;
 321                n = weight(p);
 322                if (0 <= n)
 323                        continue;
 324                distance = count_distance(p);
 325                clear_distance(p);
 326                weight_set(p, distance);
 327
 328                /* Does it happen to be at exactly half-way? */
 329                if (halfway(p, distance, nr)) {
 330                        p->next = NULL;
 331                        *reaches = distance;
 332                        free(weights);
 333                        return p;
 334                }
 335                counted++;
 336        }
 337
 338        while (counted < nr) {
 339                for (p = list; p; p = p->next) {
 340                        struct commit_list *q;
 341
 342                        if (!commit_interesting(p) || 0 < weight(p))
 343                                continue;
 344                        for (q = p->item->parents; q; q = q->next)
 345                                if (commit_interesting(q) && 0 < weight(q))
 346                                        break;
 347                        if (!q)
 348                                continue;
 349                        weight_set(p, weight(q)+1);
 350                        counted++;
 351
 352                        /* Does it happen to be at exactly half-way? */
 353                        distance = weight(p);
 354                        if (halfway(p, distance, nr)) {
 355                                p->next = NULL;
 356                                *reaches = distance;
 357                                free(weights);
 358                                return p;
 359                        }
 360                }
 361        }
 362
 363        /* Then find the best one */
 364        counted = 0;
 365        best = list;
 366        for (p = list; p; p = p->next) {
 367                if (!commit_interesting(p))
 368                        continue;
 369                distance = weight(p);
 370                if (nr - distance < distance)
 371                        distance = nr - distance;
 372                if (distance > counted) {
 373                        best = p;
 374                        counted = distance;
 375                        *reaches = weight(p);
 376                }
 377        }
 378        if (best)
 379                best->next = NULL;
 380        free(weights);
 381        return best;
 382}
 383
 384static void read_revisions_from_stdin(struct rev_info *revs)
 385{
 386        char line[1000];
 387
 388        while (fgets(line, sizeof(line), stdin) != NULL) {
 389                int len = strlen(line);
 390                if (line[len - 1] == '\n')
 391                        line[--len] = 0;
 392                if (!len)
 393                        break;
 394                if (line[0] == '-')
 395                        die("options not supported in --stdin mode");
 396                if (handle_revision_arg(line, revs, 0, 1))
 397                        die("bad revision '%s'", line);
 398        }
 399}
 400
 401int cmd_rev_list(int argc, const char **argv, const char *prefix)
 402{
 403        struct commit_list *list;
 404        int i;
 405        int read_from_stdin = 0;
 406        int bisect_show_vars = 0;
 407
 408        git_config(git_default_config);
 409        init_revisions(&revs, prefix);
 410        revs.abbrev = 0;
 411        revs.commit_format = CMIT_FMT_UNSPECIFIED;
 412        argc = setup_revisions(argc, argv, &revs, NULL);
 413
 414        for (i = 1 ; i < argc; i++) {
 415                const char *arg = argv[i];
 416
 417                if (!strcmp(arg, "--header")) {
 418                        revs.verbose_header = 1;
 419                        continue;
 420                }
 421                if (!strcmp(arg, "--timestamp")) {
 422                        show_timestamp = 1;
 423                        continue;
 424                }
 425                if (!strcmp(arg, "--bisect")) {
 426                        bisect_list = 1;
 427                        continue;
 428                }
 429                if (!strcmp(arg, "--bisect-vars")) {
 430                        bisect_list = 1;
 431                        bisect_show_vars = 1;
 432                        continue;
 433                }
 434                if (!strcmp(arg, "--stdin")) {
 435                        if (read_from_stdin++)
 436                                die("--stdin given twice?");
 437                        read_revisions_from_stdin(&revs);
 438                        continue;
 439                }
 440                usage(rev_list_usage);
 441
 442        }
 443        if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
 444                /* The command line has a --pretty  */
 445                hdr_termination = '\n';
 446                if (revs.commit_format == CMIT_FMT_ONELINE)
 447                        header_prefix = "";
 448                else
 449                        header_prefix = "commit ";
 450        }
 451        else if (revs.verbose_header)
 452                /* Only --header was specified */
 453                revs.commit_format = CMIT_FMT_RAW;
 454
 455        list = revs.commits;
 456
 457        if ((!list &&
 458             (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
 459              !revs.pending.nr)) ||
 460            revs.diff)
 461                usage(rev_list_usage);
 462
 463        save_commit_buffer = revs.verbose_header || revs.grep_filter;
 464        track_object_refs = 0;
 465        if (bisect_list)
 466                revs.limited = 1;
 467
 468        prepare_revision_walk(&revs);
 469        if (revs.tree_objects)
 470                mark_edges_uninteresting(revs.commits, &revs, show_edge);
 471
 472        if (bisect_list) {
 473                int reaches = reaches, all = all;
 474
 475                if (!revs.prune_fn)
 476                        revs.commits = find_bisection_2(revs.commits,
 477                                                        &reaches, &all);
 478                else
 479                        revs.commits = find_bisection(revs.commits,
 480                                                      &reaches, &all);
 481                if (bisect_show_vars) {
 482                        int cnt;
 483                        if (!revs.commits)
 484                                return 1;
 485                        /*
 486                         * revs.commits can reach "reaches" commits among
 487                         * "all" commits.  If it is good, then there are
 488                         * (all-reaches) commits left to be bisected.
 489                         * On the other hand, if it is bad, then the set
 490                         * to bisect is "reaches".
 491                         * A bisect set of size N has (N-1) commits further
 492                         * to test, as we already know one bad one.
 493                         */
 494                        cnt = all-reaches;
 495                        if (cnt < reaches)
 496                                cnt = reaches;
 497                        printf("bisect_rev=%s\n"
 498                               "bisect_nr=%d\n"
 499                               "bisect_good=%d\n"
 500                               "bisect_bad=%d\n"
 501                               "bisect_all=%d\n",
 502                               sha1_to_hex(revs.commits->item->object.sha1),
 503                               cnt - 1,
 504                               all - reaches - 1,
 505                               reaches - 1,
 506                               all);
 507                        return 0;
 508                }
 509        }
 510
 511        traverse_commit_list(&revs, show_commit, show_object);
 512
 513        return 0;
 514}