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