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