builtin/fast-export.c

   1 /*
   2  * "git fast-export" builtin command
   3  *
   4  * Copyright (C) 2007 Johannes E. Schindelin
   5  */
   6 #include "builtin.h"
   7 #include "config.h"
   8 #include "gettext.h"
   9 #include "hex.h"
  10 #include "refs.h"
  11 #include "refspec.h"
  12 #include "object-file.h"
  13 #include "object-store-ll.h"
  14 #include "commit.h"
  15 #include "object.h"
  16 #include "tag.h"
  17 #include "diff.h"
  18 #include "diffcore.h"
  19 #include "log-tree.h"
  20 #include "revision.h"
  21 #include "decorate.h"
  22 #include "string-list.h"
  23 #include "utf8.h"
  24 #include "parse-options.h"
  25 #include "quote.h"
  26 #include "remote.h"
  27 #include "blob.h"
  28
  29 static const char *fast_export_usage[] = {
  30         N_("git fast-export [<rev-list-opts>]"),
  31         NULL
  32 };
  33
  34 static int progress;
  35 static enum signed_tag_mode { SIGNED_TAG_ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = SIGNED_TAG_ABORT;
  36 static enum tag_of_filtered_mode { TAG_FILTERING_ABORT, DROP, REWRITE } tag_of_filtered_mode = TAG_FILTERING_ABORT;
  37 static enum reencode_mode { REENCODE_ABORT, REENCODE_YES, REENCODE_NO } reencode_mode = REENCODE_ABORT;
  38 static int fake_missing_tagger;
  39 static int use_done_feature;
  40 static int no_data;
  41 static int full_tree;
  42 static int reference_excluded_commits;
  43 static int show_original_ids;
  44 static int mark_tags;
  45 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  46 static struct string_list tag_refs = STRING_LIST_INIT_NODUP;
  47 static struct refspec refspecs = REFSPEC_INIT_FETCH;
  48 static int anonymize;
  49 static struct hashmap anonymized_seeds;
  50 static struct revision_sources revision_sources;
  51
  52 static int parse_opt_signed_tag_mode(const struct option *opt,
  53                                      const char *arg, int unset)
  54 {
  55         enum signed_tag_mode *val = opt->value;
  56
  57         if (unset || !strcmp(arg, "abort"))
  58                 *val = SIGNED_TAG_ABORT;
  59         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  60                 *val = VERBATIM;
  61         else if (!strcmp(arg, "warn"))
  62                 *val = WARN;
  63         else if (!strcmp(arg, "warn-strip"))
  64                 *val = WARN_STRIP;
  65         else if (!strcmp(arg, "strip"))
  66                 *val = STRIP;
  67         else
  68                 return error("Unknown signed-tags mode: %s", arg);
  69         return 0;
  70 }
  71
  72 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  73                                           const char *arg, int unset)
  74 {
  75         enum tag_of_filtered_mode *val = opt->value;
  76
  77         if (unset || !strcmp(arg, "abort"))
  78                 *val = TAG_FILTERING_ABORT;
  79         else if (!strcmp(arg, "drop"))
  80                 *val = DROP;
  81         else if (!strcmp(arg, "rewrite"))
  82                 *val = REWRITE;
  83         else
  84                 return error("Unknown tag-of-filtered mode: %s", arg);
  85         return 0;
  86 }
  87
  88 static int parse_opt_reencode_mode(const struct option *opt,
  89                                    const char *arg, int unset)
  90 {
  91         enum reencode_mode *val = opt->value;
  92
  93         if (unset) {
  94                 *val = REENCODE_ABORT;
  95                 return 0;
  96         }
  97
  98         switch (git_parse_maybe_bool(arg)) {
  99         case 0:
 100                 *val = REENCODE_NO;
 101                 break;
 102         case 1:
 103                 *val = REENCODE_YES;
 104                 break;
 105         default:
 106                 if (!strcasecmp(arg, "abort"))
 107                         *val = REENCODE_ABORT;
 108                 else
 109                         return error("Unknown reencoding mode: %s", arg);
 110         }
 111
 112         return 0;
 113 }
 114
 115 static struct decoration idnums;
 116 static uint32_t last_idnum;
 117 struct anonymized_entry {
 118         struct hashmap_entry hash;
 119         char *anon;
 120         const char orig[FLEX_ARRAY];
 121 };
 122
 123 struct anonymized_entry_key {
 124         struct hashmap_entry hash;
 125         const char *orig;
 126         size_t orig_len;
 127 };
 128
 129 static int anonymized_entry_cmp(const void *cmp_data UNUSED,
 130                                 const struct hashmap_entry *eptr,
 131                                 const struct hashmap_entry *entry_or_key,
 132                                 const void *keydata)
 133 {
 134         const struct anonymized_entry *a, *b;
 135
 136         a = container_of(eptr, const struct anonymized_entry, hash);
 137         if (keydata) {
 138                 const struct anonymized_entry_key *key = keydata;
 139                 int equal = !xstrncmpz(a->orig, key->orig, key->orig_len);
 140                 return !equal;
 141         }
 142
 143         b = container_of(entry_or_key, const struct anonymized_entry, hash);
 144         return strcmp(a->orig, b->orig);
 145 }
 146
 147 static struct anonymized_entry *add_anonymized_entry(struct hashmap *map,
 148                                                      unsigned hash,
 149                                                      const char *orig, size_t len,
 150                                                      char *anon)
 151 {
 152         struct anonymized_entry *ret, *old;
 153
 154         if (!map->cmpfn)
 155                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
 156
 157         FLEX_ALLOC_MEM(ret, orig, orig, len);
 158         hashmap_entry_init(&ret->hash, hash);
 159         ret->anon = anon;
 160         old = hashmap_put_entry(map, ret, hash);
 161
 162         if (old) {
 163                 free(old->anon);
 164                 free(old);
 165         }
 166
 167         return ret;
 168 }
 169
 170 /*
 171  * Basically keep a cache of X->Y so that we can repeatedly replace
 172  * the same anonymized string with another. The actual generation
 173  * is farmed out to the generate function.
 174  */
 175 static const char *anonymize_str(struct hashmap *map,
 176                                  char *(*generate)(void),
 177                                  const char *orig, size_t len)
 178 {
 179         struct anonymized_entry_key key;
 180         struct anonymized_entry *ret;
 181
 182         hashmap_entry_init(&key.hash, memhash(orig, len));
 183         key.orig = orig;
 184         key.orig_len = len;
 185
 186         /* First check if it's a token the user configured manually... */
 187         ret = hashmap_get_entry(&anonymized_seeds, &key, hash, &key);
 188
 189         /* ...otherwise check if we've already seen it in this context... */
 190         if (!ret)
 191                 ret = hashmap_get_entry(map, &key, hash, &key);
 192
 193         /* ...and finally generate a new mapping if necessary */
 194         if (!ret)
 195                 ret = add_anonymized_entry(map, key.hash.hash,
 196                                            orig, len, generate());
 197
 198         return ret->anon;
 199 }
 200
 201 /*
 202  * We anonymize each component of a path individually,
 203  * so that paths a/b and a/c will share a common root.
 204  * The paths are cached via anonymize_mem so that repeated
 205  * lookups for "a" will yield the same value.
 206  */
 207 static void anonymize_path(struct strbuf *out, const char *path,
 208                            struct hashmap *map,
 209                            char *(*generate)(void))
 210 {
 211         while (*path) {
 212                 const char *end_of_component = strchrnul(path, '/');
 213                 size_t len = end_of_component - path;
 214                 const char *c = anonymize_str(map, generate, path, len);
 215                 strbuf_addstr(out, c);
 216                 path = end_of_component;
 217                 if (*path)
 218                         strbuf_addch(out, *path++);
 219         }
 220 }
 221
 222 static inline void *mark_to_ptr(uint32_t mark)
 223 {
 224         return (void *)(uintptr_t)mark;
 225 }
 226
 227 static inline uint32_t ptr_to_mark(void * mark)
 228 {
 229         return (uint32_t)(uintptr_t)mark;
 230 }
 231
 232 static inline void mark_object(struct object *object, uint32_t mark)
 233 {
 234         add_decoration(&idnums, object, mark_to_ptr(mark));
 235 }
 236
 237 static inline void mark_next_object(struct object *object)
 238 {
 239         mark_object(object, ++last_idnum);
 240 }
 241
 242 static int get_object_mark(struct object *object)
 243 {
 244         void *decoration = lookup_decoration(&idnums, object);
 245         if (!decoration)
 246                 return 0;
 247         return ptr_to_mark(decoration);
 248 }
 249
 250 static struct commit *rewrite_commit(struct commit *p)
 251 {
 252         for (;;) {
 253                 if (p->parents && p->parents->next)
 254                         break;
 255                 if (p->object.flags & UNINTERESTING)
 256                         break;
 257                 if (!(p->object.flags & TREESAME))
 258                         break;
 259                 if (!p->parents)
 260                         return NULL;
 261                 p = p->parents->item;
 262         }
 263         return p;
 264 }
 265
 266 static void show_progress(void)
 267 {
 268         static int counter = 0;
 269         if (!progress)
 270                 return;
 271         if ((++counter % progress) == 0)
 272                 printf("progress %d objects\n", counter);
 273 }
 274
 275 /*
 276  * Ideally we would want some transformation of the blob data here
 277  * that is unreversible, but would still be the same size and have
 278  * the same data relationship to other blobs (so that we get the same
 279  * delta and packing behavior as the original). But the first and last
 280  * requirements there are probably mutually exclusive, so let's take
 281  * the easy way out for now, and just generate arbitrary content.
 282  *
 283  * There's no need to cache this result with anonymize_mem, since
 284  * we already handle blob content caching with marks.
 285  */
 286 static char *anonymize_blob(unsigned long *size)
 287 {
 288         static int counter;
 289         struct strbuf out = STRBUF_INIT;
 290         strbuf_addf(&out, "anonymous blob %d", counter++);
 291         *size = out.len;
 292         return strbuf_detach(&out, NULL);
 293 }
 294
 295 static void export_blob(const struct object_id *oid)
 296 {
 297         unsigned long size;
 298         enum object_type type;
 299         char *buf;
 300         struct object *object;
 301         int eaten;
 302
 303         if (no_data)
 304                 return;
 305
 306         if (is_null_oid(oid))
 307                 return;
 308
 309         object = lookup_object(the_repository, oid);
 310         if (object && object->flags & SHOWN)
 311                 return;
 312
 313         if (anonymize) {
 314                 buf = anonymize_blob(&size);
 315                 object = (struct object *)lookup_blob(the_repository, oid);
 316                 eaten = 0;
 317         } else {
 318                 buf = repo_read_object_file(the_repository, oid, &type, &size);
 319                 if (!buf)
 320                         die("could not read blob %s", oid_to_hex(oid));
 321                 if (check_object_signature(the_repository, oid, buf, size,
 322                                            type) < 0)
 323                         die("oid mismatch in blob %s", oid_to_hex(oid));
 324                 object = parse_object_buffer(the_repository, oid, type,
 325                                              size, buf, &eaten);
 326         }
 327
 328         if (!object)
 329                 die("Could not read blob %s", oid_to_hex(oid));
 330
 331         mark_next_object(object);
 332
 333         printf("blob\nmark :%"PRIu32"\n", last_idnum);
 334         if (show_original_ids)
 335                 printf("original-oid %s\n", oid_to_hex(oid));
 336         printf("data %"PRIuMAX"\n", (uintmax_t)size);
 337         if (size && fwrite(buf, size, 1, stdout) != 1)
 338                 die_errno("could not write blob '%s'", oid_to_hex(oid));
 339         printf("\n");
 340
 341         show_progress();
 342
 343         object->flags |= SHOWN;
 344         if (!eaten)
 345                 free(buf);
 346 }
 347
 348 static int depth_first(const void *a_, const void *b_)
 349 {
 350         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 351         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 352         const char *name_a, *name_b;
 353         int len_a, len_b, len;
 354         int cmp;
 355
 356         name_a = a->one ? a->one->path : a->two->path;
 357         name_b = b->one ? b->one->path : b->two->path;
 358
 359         len_a = strlen(name_a);
 360         len_b = strlen(name_b);
 361         len = (len_a < len_b) ? len_a : len_b;
 362
 363         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 364         cmp = memcmp(name_a, name_b, len);
 365         if (cmp)
 366                 return cmp;
 367         cmp = len_b - len_a;
 368         if (cmp)
 369                 return cmp;
 370         /*
 371          * Move 'R'ename entries last so that all references of the file
 372          * appear in the output before it is renamed (e.g., when a file
 373          * was copied and renamed in the same commit).
 374          */
 375         return (a->status == 'R') - (b->status == 'R');
 376 }
 377
 378 static void print_path_1(const char *path)
 379 {
 380         int need_quote = quote_c_style(path, NULL, NULL, 0);
 381         if (need_quote)
 382                 quote_c_style(path, NULL, stdout, 0);
 383         else if (strchr(path, ' '))
 384                 printf("\"%s\"", path);
 385         else
 386                 printf("%s", path);
 387 }
 388
 389 static char *anonymize_path_component(void)
 390 {
 391         static int counter;
 392         struct strbuf out = STRBUF_INIT;
 393         strbuf_addf(&out, "path%d", counter++);
 394         return strbuf_detach(&out, NULL);
 395 }
 396
 397 static void print_path(const char *path)
 398 {
 399         if (!anonymize)
 400                 print_path_1(path);
 401         else {
 402                 static struct hashmap paths;
 403                 static struct strbuf anon = STRBUF_INIT;
 404
 405                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 406                 print_path_1(anon.buf);
 407                 strbuf_reset(&anon);
 408         }
 409 }
 410
 411 static char *generate_fake_oid(void)
 412 {
 413         static uint32_t counter = 1; /* avoid null oid */
 414         const unsigned hashsz = the_hash_algo->rawsz;
 415         struct object_id oid;
 416         char *hex = xmallocz(GIT_MAX_HEXSZ);
 417
 418         oidclr(&oid);
 419         put_be32(oid.hash + hashsz - 4, counter++);
 420         return oid_to_hex_r(hex, &oid);
 421 }
 422
 423 static const char *anonymize_oid(const char *oid_hex)
 424 {
 425         static struct hashmap objs;
 426         size_t len = strlen(oid_hex);
 427         return anonymize_str(&objs, generate_fake_oid, oid_hex, len);
 428 }
 429
 430 static void show_filemodify(struct diff_queue_struct *q,
 431                             struct diff_options *options UNUSED, void *data)
 432 {
 433         int i;
 434         struct string_list *changed = data;
 435
 436         /*
 437          * Handle files below a directory first, in case they are all deleted
 438          * and the directory changes to a file or symlink.
 439          */
 440         QSORT(q->queue, q->nr, depth_first);
 441
 442         for (i = 0; i < q->nr; i++) {
 443                 struct diff_filespec *ospec = q->queue[i]->one;
 444                 struct diff_filespec *spec = q->queue[i]->two;
 445
 446                 switch (q->queue[i]->status) {
 447                 case DIFF_STATUS_DELETED:
 448                         printf("D ");
 449                         print_path(spec->path);
 450                         string_list_insert(changed, spec->path);
 451                         putchar('\n');
 452                         break;
 453
 454                 case DIFF_STATUS_COPIED:
 455                 case DIFF_STATUS_RENAMED:
 456                         /*
 457                          * If a change in the file corresponding to ospec->path
 458                          * has been observed, we cannot trust its contents
 459                          * because the diff is calculated based on the prior
 460                          * contents, not the current contents.  So, declare a
 461                          * copy or rename only if there was no change observed.
 462                          */
 463                         if (!string_list_has_string(changed, ospec->path)) {
 464                                 printf("%c ", q->queue[i]->status);
 465                                 print_path(ospec->path);
 466                                 putchar(' ');
 467                                 print_path(spec->path);
 468                                 string_list_insert(changed, spec->path);
 469                                 putchar('\n');
 470
 471                                 if (oideq(&ospec->oid, &spec->oid) &&
 472                                     ospec->mode == spec->mode)
 473                                         break;
 474                         }
 475                         /* fallthrough */
 476
 477                 case DIFF_STATUS_TYPE_CHANGED:
 478                 case DIFF_STATUS_MODIFIED:
 479                 case DIFF_STATUS_ADDED:
 480                         /*
 481                          * Links refer to objects in another repositories;
 482                          * output the SHA-1 verbatim.
 483                          */
 484                         if (no_data || S_ISGITLINK(spec->mode))
 485                                 printf("M %06o %s ", spec->mode,
 486                                        anonymize ?
 487                                        anonymize_oid(oid_to_hex(&spec->oid)) :
 488                                        oid_to_hex(&spec->oid));
 489                         else {
 490                                 struct object *object = lookup_object(the_repository,
 491                                                                       &spec->oid);
 492                                 printf("M %06o :%d ", spec->mode,
 493                                        get_object_mark(object));
 494                         }
 495                         print_path(spec->path);
 496                         string_list_insert(changed, spec->path);
 497                         putchar('\n');
 498                         break;
 499
 500                 default:
 501                         die("Unexpected comparison status '%c' for %s, %s",
 502                                 q->queue[i]->status,
 503                                 ospec->path ? ospec->path : "none",
 504                                 spec->path ? spec->path : "none");
 505                 }
 506         }
 507 }
 508
 509 static const char *find_encoding(const char *begin, const char *end)
 510 {
 511         const char *needle = "\nencoding ";
 512         char *bol, *eol;
 513
 514         bol = memmem(begin, end ? end - begin : strlen(begin),
 515                      needle, strlen(needle));
 516         if (!bol)
 517                 return NULL;
 518         bol += strlen(needle);
 519         eol = strchrnul(bol, '\n');
 520         *eol = '\0';
 521         return bol;
 522 }
 523
 524 static char *anonymize_ref_component(void)
 525 {
 526         static int counter;
 527         struct strbuf out = STRBUF_INIT;
 528         strbuf_addf(&out, "ref%d", counter++);
 529         return strbuf_detach(&out, NULL);
 530 }
 531
 532 static const char *anonymize_refname(const char *refname)
 533 {
 534         /*
 535          * If any of these prefixes is found, we will leave it intact
 536          * so that tags remain tags and so forth.
 537          */
 538         static const char *prefixes[] = {
 539                 "refs/heads/",
 540                 "refs/tags/",
 541                 "refs/remotes/",
 542                 "refs/"
 543         };
 544         static struct hashmap refs;
 545         static struct strbuf anon = STRBUF_INIT;
 546         int i;
 547
 548         strbuf_reset(&anon);
 549         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 550                 if (skip_prefix(refname, prefixes[i], &refname)) {
 551                         strbuf_addstr(&anon, prefixes[i]);
 552                         break;
 553                 }
 554         }
 555
 556         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 557         return anon.buf;
 558 }
 559
 560 /*
 561  * We do not even bother to cache commit messages, as they are unlikely
 562  * to be repeated verbatim, and it is not that interesting when they are.
 563  */
 564 static char *anonymize_commit_message(void)
 565 {
 566         static int counter;
 567         return xstrfmt("subject %d\n\nbody\n", counter++);
 568 }
 569
 570 static char *anonymize_ident(void)
 571 {
 572         static int counter;
 573         struct strbuf out = STRBUF_INIT;
 574         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 575         counter++;
 576         return strbuf_detach(&out, NULL);
 577 }
 578
 579 /*
 580  * Our strategy here is to anonymize the names and email addresses,
 581  * but keep timestamps intact, as they influence things like traversal
 582  * order (and by themselves should not be too revealing).
 583  */
 584 static void anonymize_ident_line(const char **beg, const char **end)
 585 {
 586         static struct hashmap idents;
 587         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 588         static unsigned which_buffer;
 589
 590         struct strbuf *out;
 591         struct ident_split split;
 592         const char *end_of_header;
 593
 594         out = &buffers[which_buffer++];
 595         which_buffer %= ARRAY_SIZE(buffers);
 596         strbuf_reset(out);
 597
 598         /* skip "committer", "author", "tagger", etc */
 599         end_of_header = strchr(*beg, ' ');
 600         if (!end_of_header)
 601                 BUG("malformed line fed to anonymize_ident_line: %.*s",
 602                     (int)(*end - *beg), *beg);
 603         end_of_header++;
 604         strbuf_add(out, *beg, end_of_header - *beg);
 605
 606         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 607             split.date_begin) {
 608                 const char *ident;
 609                 size_t len;
 610
 611                 len = split.mail_end - split.name_begin;
 612                 ident = anonymize_str(&idents, anonymize_ident,
 613                                       split.name_begin, len);
 614                 strbuf_addstr(out, ident);
 615                 strbuf_addch(out, ' ');
 616                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 617         } else {
 618                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 619         }
 620
 621         *beg = out->buf;
 622         *end = out->buf + out->len;
 623 }
 624
 625 static void handle_commit(struct commit *commit, struct rev_info *rev,
 626                           struct string_list *paths_of_changed_objects)
 627 {
 628         int saved_output_format = rev->diffopt.output_format;
 629         const char *commit_buffer;
 630         const char *author, *author_end, *committer, *committer_end;
 631         const char *encoding, *message;
 632         char *reencoded = NULL;
 633         struct commit_list *p;
 634         const char *refname;
 635         int i;
 636
 637         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 638
 639         parse_commit_or_die(commit);
 640         commit_buffer = repo_get_commit_buffer(the_repository, commit, NULL);
 641         author = strstr(commit_buffer, "\nauthor ");
 642         if (!author)
 643                 die("could not find author in commit %s",
 644                     oid_to_hex(&commit->object.oid));
 645         author++;
 646         author_end = strchrnul(author, '\n');
 647         committer = strstr(author_end, "\ncommitter ");
 648         if (!committer)
 649                 die("could not find committer in commit %s",
 650                     oid_to_hex(&commit->object.oid));
 651         committer++;
 652         committer_end = strchrnul(committer, '\n');
 653         message = strstr(committer_end, "\n\n");
 654         encoding = find_encoding(committer_end, message);
 655         if (message)
 656                 message += 2;
 657
 658         if (commit->parents &&
 659             (get_object_mark(&commit->parents->item->object) != 0 ||
 660              reference_excluded_commits) &&
 661             !full_tree) {
 662                 parse_commit_or_die(commit->parents->item);
 663                 diff_tree_oid(get_commit_tree_oid(commit->parents->item),
 664                               get_commit_tree_oid(commit), "", &rev->diffopt);
 665         }
 666         else
 667                 diff_root_tree_oid(get_commit_tree_oid(commit),
 668                                    "", &rev->diffopt);
 669
 670         /* Export the referenced blobs, and remember the marks. */
 671         for (i = 0; i < diff_queued_diff.nr; i++)
 672                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 673                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 674
 675         refname = *revision_sources_at(&revision_sources, commit);
 676         /*
 677          * FIXME: string_list_remove() below for each ref is overall
 678          * O(N^2).  Compared to a history walk and diffing trees, this is
 679          * just lost in the noise in practice.  However, theoretically a
 680          * repo may have enough refs for this to become slow.
 681          */
 682         string_list_remove(&extra_refs, refname, 0);
 683         if (anonymize) {
 684                 refname = anonymize_refname(refname);
 685                 anonymize_ident_line(&committer, &committer_end);
 686                 anonymize_ident_line(&author, &author_end);
 687         }
 688
 689         mark_next_object(&commit->object);
 690         if (anonymize) {
 691                 reencoded = anonymize_commit_message();
 692         } else if (encoding) {
 693                 switch(reencode_mode) {
 694                 case REENCODE_YES:
 695                         reencoded = reencode_string(message, "UTF-8", encoding);
 696                         break;
 697                 case REENCODE_NO:
 698                         break;
 699                 case REENCODE_ABORT:
 700                         die("Encountered commit-specific encoding %s in commit "
 701                             "%s; use --reencode=[yes|no] to handle it",
 702                             encoding, oid_to_hex(&commit->object.oid));
 703                 }
 704         }
 705         if (!commit->parents)
 706                 printf("reset %s\n", refname);
 707         printf("commit %s\nmark :%"PRIu32"\n", refname, last_idnum);
 708         if (show_original_ids)
 709                 printf("original-oid %s\n", oid_to_hex(&commit->object.oid));
 710         printf("%.*s\n%.*s\n",
 711                (int)(author_end - author), author,
 712                (int)(committer_end - committer), committer);
 713         if (!reencoded && encoding)
 714                 printf("encoding %s\n", encoding);
 715         printf("data %u\n%s",
 716                (unsigned)(reencoded
 717                           ? strlen(reencoded) : message
 718                           ? strlen(message) : 0),
 719                reencoded ? reencoded : message ? message : "");
 720         free(reencoded);
 721         repo_unuse_commit_buffer(the_repository, commit, commit_buffer);
 722
 723         for (i = 0, p = commit->parents; p; p = p->next) {
 724                 struct object *obj = &p->item->object;
 725                 int mark = get_object_mark(obj);
 726
 727                 if (!mark && !reference_excluded_commits)
 728                         continue;
 729                 if (i == 0)
 730                         printf("from ");
 731                 else
 732                         printf("merge ");
 733                 if (mark)
 734                         printf(":%d\n", mark);
 735                 else
 736                         printf("%s\n",
 737                                anonymize ?
 738                                anonymize_oid(oid_to_hex(&obj->oid)) :
 739                                oid_to_hex(&obj->oid));
 740                 i++;
 741         }
 742
 743         if (full_tree)
 744                 printf("deleteall\n");
 745         log_tree_diff_flush(rev);
 746         string_list_clear(paths_of_changed_objects, 0);
 747         rev->diffopt.output_format = saved_output_format;
 748
 749         printf("\n");
 750
 751         show_progress();
 752 }
 753
 754 static char *anonymize_tag(void)
 755 {
 756         static int counter;
 757         struct strbuf out = STRBUF_INIT;
 758         strbuf_addf(&out, "tag message %d", counter++);
 759         return strbuf_detach(&out, NULL);
 760 }
 761
 762
 763 static void handle_tag(const char *name, struct tag *tag)
 764 {
 765         unsigned long size;
 766         enum object_type type;
 767         char *buf;
 768         const char *tagger, *tagger_end, *message;
 769         size_t message_size = 0;
 770         struct object *tagged;
 771         int tagged_mark;
 772         struct commit *p;
 773
 774         /* Trees have no identifier in fast-export output, thus we have no way
 775          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 776          * such tags.
 777          */
 778         tagged = tag->tagged;
 779         while (tagged->type == OBJ_TAG) {
 780                 tagged = ((struct tag *)tagged)->tagged;
 781         }
 782         if (tagged->type == OBJ_TREE) {
 783                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 784                         oid_to_hex(&tag->object.oid));
 785                 return;
 786         }
 787
 788         buf = repo_read_object_file(the_repository, &tag->object.oid, &type,
 789                                     &size);
 790         if (!buf)
 791                 die("could not read tag %s", oid_to_hex(&tag->object.oid));
 792         message = memmem(buf, size, "\n\n", 2);
 793         if (message) {
 794                 message += 2;
 795                 message_size = strlen(message);
 796         }
 797         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 798         if (!tagger) {
 799                 if (fake_missing_tagger)
 800                         tagger = "tagger Unspecified Tagger "
 801                                 "<unspecified-tagger> 0 +0000";
 802                 else
 803                         tagger = "";
 804                 tagger_end = tagger + strlen(tagger);
 805         } else {
 806                 tagger++;
 807                 tagger_end = strchrnul(tagger, '\n');
 808                 if (anonymize)
 809                         anonymize_ident_line(&tagger, &tagger_end);
 810         }
 811
 812         if (anonymize) {
 813                 name = anonymize_refname(name);
 814                 if (message) {
 815                         static struct hashmap tags;
 816                         message = anonymize_str(&tags, anonymize_tag,
 817                                                 message, message_size);
 818                         message_size = strlen(message);
 819                 }
 820         }
 821
 822         /* handle signed tags */
 823         if (message) {
 824                 const char *signature = strstr(message,
 825                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 826                 if (signature)
 827                         switch(signed_tag_mode) {
 828                         case SIGNED_TAG_ABORT:
 829                                 die("encountered signed tag %s; use "
 830                                     "--signed-tags=<mode> to handle it",
 831                                     oid_to_hex(&tag->object.oid));
 832                         case WARN:
 833                                 warning("exporting signed tag %s",
 834                                         oid_to_hex(&tag->object.oid));
 835                                 /* fallthru */
 836                         case VERBATIM:
 837                                 break;
 838                         case WARN_STRIP:
 839                                 warning("stripping signature from tag %s",
 840                                         oid_to_hex(&tag->object.oid));
 841                                 /* fallthru */
 842                         case STRIP:
 843                                 message_size = signature + 1 - message;
 844                                 break;
 845                         }
 846         }
 847
 848         /* handle tag->tagged having been filtered out due to paths specified */
 849         tagged = tag->tagged;
 850         tagged_mark = get_object_mark(tagged);
 851         if (!tagged_mark) {
 852                 switch(tag_of_filtered_mode) {
 853                 case TAG_FILTERING_ABORT:
 854                         die("tag %s tags unexported object; use "
 855                             "--tag-of-filtered-object=<mode> to handle it",
 856                             oid_to_hex(&tag->object.oid));
 857                 case DROP:
 858                         /* Ignore this tag altogether */
 859                         free(buf);
 860                         return;
 861                 case REWRITE:
 862                         if (tagged->type == OBJ_TAG && !mark_tags) {
 863                                 die(_("Error: Cannot export nested tags unless --mark-tags is specified."));
 864                         } else if (tagged->type == OBJ_COMMIT) {
 865                                 p = rewrite_commit((struct commit *)tagged);
 866                                 if (!p) {
 867                                         printf("reset %s\nfrom %s\n\n",
 868                                                name, oid_to_hex(null_oid()));
 869                                         free(buf);
 870                                         return;
 871                                 }
 872                                 tagged_mark = get_object_mark(&p->object);
 873                         } else {
 874                                 /* tagged->type is either OBJ_BLOB or OBJ_TAG */
 875                                 tagged_mark = get_object_mark(tagged);
 876                         }
 877                 }
 878         }
 879
 880         if (tagged->type == OBJ_TAG) {
 881                 printf("reset %s\nfrom %s\n\n",
 882                        name, oid_to_hex(null_oid()));
 883         }
 884         skip_prefix(name, "refs/tags/", &name);
 885         printf("tag %s\n", name);
 886         if (mark_tags) {
 887                 mark_next_object(&tag->object);
 888                 printf("mark :%"PRIu32"\n", last_idnum);
 889         }
 890         if (tagged_mark)
 891                 printf("from :%d\n", tagged_mark);
 892         else
 893                 printf("from %s\n", oid_to_hex(&tagged->oid));
 894
 895         if (show_original_ids)
 896                 printf("original-oid %s\n", oid_to_hex(&tag->object.oid));
 897         printf("%.*s%sdata %d\n%.*s\n",
 898                (int)(tagger_end - tagger), tagger,
 899                tagger == tagger_end ? "" : "\n",
 900                (int)message_size, (int)message_size, message ? message : "");
 901         free(buf);
 902 }
 903
 904 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 905 {
 906         switch (e->item->type) {
 907         case OBJ_COMMIT:
 908                 return (struct commit *)e->item;
 909         case OBJ_TAG: {
 910                 struct tag *tag = (struct tag *)e->item;
 911
 912                 /* handle nested tags */
 913                 while (tag && tag->object.type == OBJ_TAG) {
 914                         parse_object(the_repository, &tag->object.oid);
 915                         string_list_append(&tag_refs, full_name)->util = tag;
 916                         tag = (struct tag *)tag->tagged;
 917                 }
 918                 if (!tag)
 919                         die("Tag %s points nowhere?", e->name);
 920                 return (struct commit *)tag;
 921         }
 922         default:
 923                 return NULL;
 924         }
 925 }
 926
 927 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 928 {
 929         int i;
 930
 931         for (i = 0; i < info->nr; i++) {
 932                 struct rev_cmdline_entry *e = info->rev + i;
 933                 struct object_id oid;
 934                 struct commit *commit;
 935                 char *full_name;
 936
 937                 if (e->flags & UNINTERESTING)
 938                         continue;
 939
 940                 if (repo_dwim_ref(the_repository, e->name, strlen(e->name),
 941                                   &oid, &full_name, 0) != 1)
 942                         continue;
 943
 944                 if (refspecs.nr) {
 945                         char *private;
 946                         private = apply_refspecs(&refspecs, full_name);
 947                         if (private) {
 948                                 free(full_name);
 949                                 full_name = private;
 950                         }
 951                 }
 952
 953                 commit = get_commit(e, full_name);
 954                 if (!commit) {
 955                         warning("%s: Unexpected object of type %s, skipping.",
 956                                 e->name,
 957                                 type_name(e->item->type));
 958                         continue;
 959                 }
 960
 961                 switch(commit->object.type) {
 962                 case OBJ_COMMIT:
 963                         break;
 964                 case OBJ_BLOB:
 965                         export_blob(&commit->object.oid);
 966                         continue;
 967                 default: /* OBJ_TAG (nested tags) is already handled */
 968                         warning("Tag points to object of unexpected type %s, skipping.",
 969                                 type_name(commit->object.type));
 970                         continue;
 971                 }
 972
 973                 /*
 974                  * Make sure this ref gets properly updated eventually, whether
 975                  * through a commit or manually at the end.
 976                  */
 977                 if (e->item->type != OBJ_TAG)
 978                         string_list_append(&extra_refs, full_name)->util = commit;
 979
 980                 if (!*revision_sources_at(&revision_sources, commit))
 981                         *revision_sources_at(&revision_sources, commit) = full_name;
 982         }
 983
 984         string_list_sort(&extra_refs);
 985         string_list_remove_duplicates(&extra_refs, 0);
 986 }
 987
 988 static void handle_tags_and_duplicates(struct string_list *extras)
 989 {
 990         struct commit *commit;
 991         int i;
 992
 993         for (i = extras->nr - 1; i >= 0; i--) {
 994                 const char *name = extras->items[i].string;
 995                 struct object *object = extras->items[i].util;
 996                 int mark;
 997
 998                 switch (object->type) {
 999                 case OBJ_TAG:
1000                         handle_tag(name, (struct tag *)object);
1001                         break;
1002                 case OBJ_COMMIT:
1003                         if (anonymize)
1004                                 name = anonymize_refname(name);
1005                         /* create refs pointing to already seen commits */
1006                         commit = rewrite_commit((struct commit *)object);
1007                         if (!commit) {
1008                                 /*
1009                                  * Neither this object nor any of its
1010                                  * ancestors touch any relevant paths, so
1011                                  * it has been filtered to nothing.  Delete
1012                                  * it.
1013                                  */
1014                                 printf("reset %s\nfrom %s\n\n",
1015                                        name, oid_to_hex(null_oid()));
1016                                 continue;
1017                         }
1018
1019                         mark = get_object_mark(&commit->object);
1020                         if (!mark) {
1021                                 /*
1022                                  * Getting here means we have a commit which
1023                                  * was excluded by a negative refspec (e.g.
1024                                  * fast-export ^HEAD HEAD).  If we are
1025                                  * referencing excluded commits, set the ref
1026                                  * to the exact commit.  Otherwise, the user
1027                                  * wants the branch exported but every commit
1028                                  * in its history to be deleted, which basically
1029                                  * just means deletion of the ref.
1030                                  */
1031                                 if (!reference_excluded_commits) {
1032                                         /* delete the ref */
1033                                         printf("reset %s\nfrom %s\n\n",
1034                                                name, oid_to_hex(null_oid()));
1035                                         continue;
1036                                 }
1037                                 /* set ref to commit using oid, not mark */
1038                                 printf("reset %s\nfrom %s\n\n", name,
1039                                        oid_to_hex(&commit->object.oid));
1040                                 continue;
1041                         }
1042
1043                         printf("reset %s\nfrom :%d\n\n", name, mark
1044                                );
1045                         show_progress();
1046                         break;
1047                 }
1048         }
1049 }
1050
1051 static void export_marks(char *file)
1052 {
1053         unsigned int i;
1054         uint32_t mark;
1055         struct decoration_entry *deco = idnums.entries;
1056         FILE *f;
1057         int e = 0;
1058
1059         f = fopen_for_writing(file);
1060         if (!f)
1061                 die_errno("Unable to open marks file %s for writing.", file);
1062
1063         for (i = 0; i < idnums.size; i++) {
1064                 if (deco->base && deco->base->type == 1) {
1065                         mark = ptr_to_mark(deco->decoration);
1066                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
1067                                 oid_to_hex(&deco->base->oid)) < 0) {
1068                             e = 1;
1069                             break;
1070                         }
1071                 }
1072                 deco++;
1073         }
1074
1075         e |= ferror(f);
1076         e |= fclose(f);
1077         if (e)
1078                 error("Unable to write marks file %s.", file);
1079 }
1080
1081 static void import_marks(char *input_file, int check_exists)
1082 {
1083         char line[512];
1084         FILE *f;
1085         struct stat sb;
1086
1087         if (check_exists && stat(input_file, &sb))
1088                 return;
1089
1090         f = xfopen(input_file, "r");
1091         while (fgets(line, sizeof(line), f)) {
1092                 uint32_t mark;
1093                 char *line_end, *mark_end;
1094                 struct object_id oid;
1095                 struct object *object;
1096                 struct commit *commit;
1097                 enum object_type type;
1098
1099                 line_end = strchr(line, '\n');
1100                 if (line[0] != ':' || !line_end)
1101                         die("corrupt mark line: %s", line);
1102                 *line_end = '\0';
1103
1104                 mark = strtoumax(line + 1, &mark_end, 10);
1105                 if (!mark || mark_end == line + 1
1106                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
1107                         die("corrupt mark line: %s", line);
1108
1109                 if (last_idnum < mark)
1110                         last_idnum = mark;
1111
1112                 type = oid_object_info(the_repository, &oid, NULL);
1113                 if (type < 0)
1114                         die("object not found: %s", oid_to_hex(&oid));
1115
1116                 if (type != OBJ_COMMIT)
1117                         /* only commits */
1118                         continue;
1119
1120                 commit = lookup_commit(the_repository, &oid);
1121                 if (!commit)
1122                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
1123
1124                 object = &commit->object;
1125
1126                 if (object->flags & SHOWN)
1127                         error("Object %s already has a mark", oid_to_hex(&oid));
1128
1129                 mark_object(object, mark);
1130
1131                 object->flags |= SHOWN;
1132         }
1133         fclose(f);
1134 }
1135
1136 static void handle_deletes(void)
1137 {
1138         int i;
1139         for (i = 0; i < refspecs.nr; i++) {
1140                 struct refspec_item *refspec = &refspecs.items[i];
1141                 if (*refspec->src)
1142                         continue;
1143
1144                 printf("reset %s\nfrom %s\n\n",
1145                                 refspec->dst, oid_to_hex(null_oid()));
1146         }
1147 }
1148
1149 static int parse_opt_anonymize_map(const struct option *opt,
1150                                    const char *arg, int unset)
1151 {
1152         struct hashmap *map = opt->value;
1153         const char *delim, *value;
1154         size_t keylen;
1155
1156         BUG_ON_OPT_NEG(unset);
1157
1158         delim = strchr(arg, ':');
1159         if (delim) {
1160                 keylen = delim - arg;
1161                 value = delim + 1;
1162         } else {
1163                 keylen = strlen(arg);
1164                 value = arg;
1165         }
1166
1167         if (!keylen || !*value)
1168                 return error(_("--anonymize-map token cannot be empty"));
1169
1170         add_anonymized_entry(map, memhash(arg, keylen), arg, keylen,
1171                              xstrdup(value));
1172
1173         return 0;
1174 }
1175
1176 int cmd_fast_export(int argc, const char **argv, const char *prefix)
1177 {
1178         struct rev_info revs;
1179         struct commit *commit;
1180         char *export_filename = NULL,
1181              *import_filename = NULL,
1182              *import_filename_if_exists = NULL;
1183         uint32_t lastimportid;
1184         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
1185         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
1186         struct option options[] = {
1187                 OPT_INTEGER(0, "progress", &progress,
1188                             N_("show progress after <n> objects")),
1189                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1190                              N_("select handling of signed tags"),
1191                              parse_opt_signed_tag_mode),
1192                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1193                              N_("select handling of tags that tag filtered objects"),
1194                              parse_opt_tag_of_filtered_mode),
1195                 OPT_CALLBACK(0, "reencode", &reencode_mode, N_("mode"),
1196                              N_("select handling of commit messages in an alternate encoding"),
1197                              parse_opt_reencode_mode),
1198                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1199                              N_("dump marks to this file")),
1200                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1201                              N_("import marks from this file")),
1202                 OPT_STRING(0, "import-marks-if-exists",
1203                              &import_filename_if_exists,
1204                              N_("file"),
1205                              N_("import marks from this file if it exists")),
1206                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1207                          N_("fake a tagger when tags lack one")),
1208                 OPT_BOOL(0, "full-tree", &full_tree,
1209                          N_("output full tree for each commit")),
1210                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1211                              N_("use the done feature to terminate the stream")),
1212                 OPT_BOOL(0, "no-data", &no_data, N_("skip output of blob data")),
1213                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1214                              N_("apply refspec to exported refs")),
1215                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1216                 OPT_CALLBACK_F(0, "anonymize-map", &anonymized_seeds, N_("from:to"),
1217                                N_("convert <from> to <to> in anonymized output"),
1218                                PARSE_OPT_NONEG, parse_opt_anonymize_map),
1219                 OPT_BOOL(0, "reference-excluded-parents",
1220                          &reference_excluded_commits, N_("reference parents which are not in fast-export stream by object id")),
1221                 OPT_BOOL(0, "show-original-ids", &show_original_ids,
1222                             N_("show original object ids of blobs/commits")),
1223                 OPT_BOOL(0, "mark-tags", &mark_tags,
1224                             N_("label tags with mark ids")),
1225
1226                 OPT_END()
1227         };
1228
1229         if (argc == 1)
1230                 usage_with_options (fast_export_usage, options);
1231
1232         /* we handle encodings */
1233         git_config(git_default_config, NULL);
1234
1235         repo_init_revisions(the_repository, &revs, prefix);
1236         init_revision_sources(&revision_sources);
1237         revs.topo_order = 1;
1238         revs.sources = &revision_sources;
1239         revs.rewrite_parents = 1;
1240         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1241                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN_OPT);
1242         argc = setup_revisions(argc, argv, &revs, NULL);
1243         if (argc > 1)
1244                 usage_with_options (fast_export_usage, options);
1245
1246         if (anonymized_seeds.cmpfn && !anonymize)
1247                 die(_("the option '%s' requires '%s'"), "--anonymize-map", "--anonymize");
1248
1249         if (refspecs_list.nr) {
1250                 int i;
1251
1252                 for (i = 0; i < refspecs_list.nr; i++)
1253                         refspec_append(&refspecs, refspecs_list.items[i].string);
1254
1255                 string_list_clear(&refspecs_list, 1);
1256         }
1257
1258         if (use_done_feature)
1259                 printf("feature done\n");
1260
1261         if (import_filename && import_filename_if_exists)
1262                 die(_("options '%s' and '%s' cannot be used together"), "--import-marks", "--import-marks-if-exists");
1263         if (import_filename)
1264                 import_marks(import_filename, 0);
1265         else if (import_filename_if_exists)
1266                 import_marks(import_filename_if_exists, 1);
1267         lastimportid = last_idnum;
1268
1269         if (import_filename && revs.prune_data.nr)
1270                 full_tree = 1;
1271
1272         get_tags_and_duplicates(&revs.cmdline);
1273
1274         if (prepare_revision_walk(&revs))
1275                 die("revision walk setup failed");
1276
1277         revs.reverse = 1;
1278         revs.diffopt.format_callback = show_filemodify;
1279         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1280         revs.diffopt.flags.recursive = 1;
1281         revs.diffopt.no_free = 1;
1282         while ((commit = get_revision(&revs)))
1283                 handle_commit(commit, &revs, &paths_of_changed_objects);
1284
1285         handle_tags_and_duplicates(&extra_refs);
1286         handle_tags_and_duplicates(&tag_refs);
1287         handle_deletes();
1288
1289         if (export_filename && lastimportid != last_idnum)
1290                 export_marks(export_filename);
1291
1292         if (use_done_feature)
1293                 printf("done\n");
1294
1295         refspec_clear(&refspecs);
1296         release_revisions(&revs);
1297
1298         return 0;
1299 }