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 int fake_missing_tagger;
  37 static int use_done_feature;
  38 static int no_data;
  39 static int full_tree;
  40 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  41 static struct refspec refspecs = REFSPEC_INIT_FETCH;
  42 static int anonymize;
  43 static struct revision_sources revision_sources;
  44
  45 static int parse_opt_signed_tag_mode(const struct option *opt,
  46                                      const char *arg, int unset)
  47 {
  48         if (unset || !strcmp(arg, "abort"))
  49                 signed_tag_mode = SIGNED_TAG_ABORT;
  50         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  51                 signed_tag_mode = VERBATIM;
  52         else if (!strcmp(arg, "warn"))
  53                 signed_tag_mode = WARN;
  54         else if (!strcmp(arg, "warn-strip"))
  55                 signed_tag_mode = WARN_STRIP;
  56         else if (!strcmp(arg, "strip"))
  57                 signed_tag_mode = STRIP;
  58         else
  59                 return error("Unknown signed-tags mode: %s", arg);
  60         return 0;
  61 }
  62
  63 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  64                                           const char *arg, int unset)
  65 {
  66         if (unset || !strcmp(arg, "abort"))
  67                 tag_of_filtered_mode = TAG_FILTERING_ABORT;
  68         else if (!strcmp(arg, "drop"))
  69                 tag_of_filtered_mode = DROP;
  70         else if (!strcmp(arg, "rewrite"))
  71                 tag_of_filtered_mode = REWRITE;
  72         else
  73                 return error("Unknown tag-of-filtered mode: %s", arg);
  74         return 0;
  75 }
  76
  77 static struct decoration idnums;
  78 static uint32_t last_idnum;
  79
  80 static int has_unshown_parent(struct commit *commit)
  81 {
  82         struct commit_list *parent;
  83
  84         for (parent = commit->parents; parent; parent = parent->next)
  85                 if (!(parent->item->object.flags & SHOWN) &&
  86                     !(parent->item->object.flags & UNINTERESTING))
  87                         return 1;
  88         return 0;
  89 }
  90
  91 struct anonymized_entry {
  92         struct hashmap_entry hash;
  93         const char *orig;
  94         size_t orig_len;
  95         const char *anon;
  96         size_t anon_len;
  97 };
  98
  99 static int anonymized_entry_cmp(const void *unused_cmp_data,
 100                                 const void *va, const void *vb,
 101                                 const void *unused_keydata)
 102 {
 103         const struct anonymized_entry *a = va, *b = vb;
 104         return a->orig_len != b->orig_len ||
 105                 memcmp(a->orig, b->orig, a->orig_len);
 106 }
 107
 108 /*
 109  * Basically keep a cache of X->Y so that we can repeatedly replace
 110  * the same anonymized string with another. The actual generation
 111  * is farmed out to the generate function.
 112  */
 113 static const void *anonymize_mem(struct hashmap *map,
 114                                  void *(*generate)(const void *, size_t *),
 115                                  const void *orig, size_t *len)
 116 {
 117         struct anonymized_entry key, *ret;
 118
 119         if (!map->cmpfn)
 120                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
 121
 122         hashmap_entry_init(&key, memhash(orig, *len));
 123         key.orig = orig;
 124         key.orig_len = *len;
 125         ret = hashmap_get(map, &key, NULL);
 126
 127         if (!ret) {
 128                 ret = xmalloc(sizeof(*ret));
 129                 hashmap_entry_init(&ret->hash, key.hash.hash);
 130                 ret->orig = xstrdup(orig);
 131                 ret->orig_len = *len;
 132                 ret->anon = generate(orig, len);
 133                 ret->anon_len = *len;
 134                 hashmap_put(map, ret);
 135         }
 136
 137         *len = ret->anon_len;
 138         return ret->anon;
 139 }
 140
 141 /*
 142  * We anonymize each component of a path individually,
 143  * so that paths a/b and a/c will share a common root.
 144  * The paths are cached via anonymize_mem so that repeated
 145  * lookups for "a" will yield the same value.
 146  */
 147 static void anonymize_path(struct strbuf *out, const char *path,
 148                            struct hashmap *map,
 149                            void *(*generate)(const void *, size_t *))
 150 {
 151         while (*path) {
 152                 const char *end_of_component = strchrnul(path, '/');
 153                 size_t len = end_of_component - path;
 154                 const char *c = anonymize_mem(map, generate, path, &len);
 155                 strbuf_add(out, c, len);
 156                 path = end_of_component;
 157                 if (*path)
 158                         strbuf_addch(out, *path++);
 159         }
 160 }
 161
 162 static inline void *mark_to_ptr(uint32_t mark)
 163 {
 164         return (void *)(uintptr_t)mark;
 165 }
 166
 167 static inline uint32_t ptr_to_mark(void * mark)
 168 {
 169         return (uint32_t)(uintptr_t)mark;
 170 }
 171
 172 static inline void mark_object(struct object *object, uint32_t mark)
 173 {
 174         add_decoration(&idnums, object, mark_to_ptr(mark));
 175 }
 176
 177 static inline void mark_next_object(struct object *object)
 178 {
 179         mark_object(object, ++last_idnum);
 180 }
 181
 182 static int get_object_mark(struct object *object)
 183 {
 184         void *decoration = lookup_decoration(&idnums, object);
 185         if (!decoration)
 186                 return 0;
 187         return ptr_to_mark(decoration);
 188 }
 189
 190 static struct commit *rewrite_commit(struct commit *p)
 191 {
 192         for (;;) {
 193                 if (p->parents && p->parents->next)
 194                         break;
 195                 if (p->object.flags & UNINTERESTING)
 196                         break;
 197                 if (!(p->object.flags & TREESAME))
 198                         break;
 199                 if (!p->parents)
 200                         return NULL;
 201                 p = p->parents->item;
 202         }
 203         return p;
 204 }
 205
 206 static void show_progress(void)
 207 {
 208         static int counter = 0;
 209         if (!progress)
 210                 return;
 211         if ((++counter % progress) == 0)
 212                 printf("progress %d objects\n", counter);
 213 }
 214
 215 /*
 216  * Ideally we would want some transformation of the blob data here
 217  * that is unreversible, but would still be the same size and have
 218  * the same data relationship to other blobs (so that we get the same
 219  * delta and packing behavior as the original). But the first and last
 220  * requirements there are probably mutually exclusive, so let's take
 221  * the easy way out for now, and just generate arbitrary content.
 222  *
 223  * There's no need to cache this result with anonymize_mem, since
 224  * we already handle blob content caching with marks.
 225  */
 226 static char *anonymize_blob(unsigned long *size)
 227 {
 228         static int counter;
 229         struct strbuf out = STRBUF_INIT;
 230         strbuf_addf(&out, "anonymous blob %d", counter++);
 231         *size = out.len;
 232         return strbuf_detach(&out, NULL);
 233 }
 234
 235 static void export_blob(const struct object_id *oid)
 236 {
 237         unsigned long size;
 238         enum object_type type;
 239         char *buf;
 240         struct object *object;
 241         int eaten;
 242
 243         if (no_data)
 244                 return;
 245
 246         if (is_null_oid(oid))
 247                 return;
 248
 249         object = lookup_object(the_repository, oid->hash);
 250         if (object && object->flags & SHOWN)
 251                 return;
 252
 253         if (anonymize) {
 254                 buf = anonymize_blob(&size);
 255                 object = (struct object *)lookup_blob(the_repository, oid);
 256                 eaten = 0;
 257         } else {
 258                 buf = read_object_file(oid, &type, &size);
 259                 if (!buf)
 260                         die("could not read blob %s", oid_to_hex(oid));
 261                 if (check_object_signature(oid, buf, size, type_name(type)) < 0)
 262                         die("oid mismatch in blob %s", oid_to_hex(oid));
 263                 object = parse_object_buffer(the_repository, oid, type,
 264                                              size, buf, &eaten);
 265         }
 266
 267         if (!object)
 268                 die("Could not read blob %s", oid_to_hex(oid));
 269
 270         mark_next_object(object);
 271
 272         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
 273         if (size && fwrite(buf, size, 1, stdout) != 1)
 274                 die_errno("could not write blob '%s'", oid_to_hex(oid));
 275         printf("\n");
 276
 277         show_progress();
 278
 279         object->flags |= SHOWN;
 280         if (!eaten)
 281                 free(buf);
 282 }
 283
 284 static int depth_first(const void *a_, const void *b_)
 285 {
 286         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 287         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 288         const char *name_a, *name_b;
 289         int len_a, len_b, len;
 290         int cmp;
 291
 292         name_a = a->one ? a->one->path : a->two->path;
 293         name_b = b->one ? b->one->path : b->two->path;
 294
 295         len_a = strlen(name_a);
 296         len_b = strlen(name_b);
 297         len = (len_a < len_b) ? len_a : len_b;
 298
 299         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 300         cmp = memcmp(name_a, name_b, len);
 301         if (cmp)
 302                 return cmp;
 303         cmp = len_b - len_a;
 304         if (cmp)
 305                 return cmp;
 306         /*
 307          * Move 'R'ename entries last so that all references of the file
 308          * appear in the output before it is renamed (e.g., when a file
 309          * was copied and renamed in the same commit).
 310          */
 311         return (a->status == 'R') - (b->status == 'R');
 312 }
 313
 314 static void print_path_1(const char *path)
 315 {
 316         int need_quote = quote_c_style(path, NULL, NULL, 0);
 317         if (need_quote)
 318                 quote_c_style(path, NULL, stdout, 0);
 319         else if (strchr(path, ' '))
 320                 printf("\"%s\"", path);
 321         else
 322                 printf("%s", path);
 323 }
 324
 325 static void *anonymize_path_component(const void *path, size_t *len)
 326 {
 327         static int counter;
 328         struct strbuf out = STRBUF_INIT;
 329         strbuf_addf(&out, "path%d", counter++);
 330         return strbuf_detach(&out, len);
 331 }
 332
 333 static void print_path(const char *path)
 334 {
 335         if (!anonymize)
 336                 print_path_1(path);
 337         else {
 338                 static struct hashmap paths;
 339                 static struct strbuf anon = STRBUF_INIT;
 340
 341                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 342                 print_path_1(anon.buf);
 343                 strbuf_reset(&anon);
 344         }
 345 }
 346
 347 static void *generate_fake_oid(const void *old, size_t *len)
 348 {
 349         static uint32_t counter = 1; /* avoid null oid */
 350         const unsigned hashsz = the_hash_algo->rawsz;
 351         unsigned char *out = xcalloc(hashsz, 1);
 352         put_be32(out + hashsz - 4, counter++);
 353         return out;
 354 }
 355
 356 static const struct object_id *anonymize_oid(const struct object_id *oid)
 357 {
 358         static struct hashmap objs;
 359         size_t len = the_hash_algo->rawsz;
 360         return anonymize_mem(&objs, generate_fake_oid, oid, &len);
 361 }
 362
 363 static void show_filemodify(struct diff_queue_struct *q,
 364                             struct diff_options *options, void *data)
 365 {
 366         int i;
 367         struct string_list *changed = data;
 368
 369         /*
 370          * Handle files below a directory first, in case they are all deleted
 371          * and the directory changes to a file or symlink.
 372          */
 373         QSORT(q->queue, q->nr, depth_first);
 374
 375         for (i = 0; i < q->nr; i++) {
 376                 struct diff_filespec *ospec = q->queue[i]->one;
 377                 struct diff_filespec *spec = q->queue[i]->two;
 378
 379                 switch (q->queue[i]->status) {
 380                 case DIFF_STATUS_DELETED:
 381                         printf("D ");
 382                         print_path(spec->path);
 383                         string_list_insert(changed, spec->path);
 384                         putchar('\n');
 385                         break;
 386
 387                 case DIFF_STATUS_COPIED:
 388                 case DIFF_STATUS_RENAMED:
 389                         /*
 390                          * If a change in the file corresponding to ospec->path
 391                          * has been observed, we cannot trust its contents
 392                          * because the diff is calculated based on the prior
 393                          * contents, not the current contents.  So, declare a
 394                          * copy or rename only if there was no change observed.
 395                          */
 396                         if (!string_list_has_string(changed, ospec->path)) {
 397                                 printf("%c ", q->queue[i]->status);
 398                                 print_path(ospec->path);
 399                                 putchar(' ');
 400                                 print_path(spec->path);
 401                                 string_list_insert(changed, spec->path);
 402                                 putchar('\n');
 403
 404                                 if (oideq(&ospec->oid, &spec->oid) &&
 405                                     ospec->mode == spec->mode)
 406                                         break;
 407                         }
 408                         /* fallthrough */
 409
 410                 case DIFF_STATUS_TYPE_CHANGED:
 411                 case DIFF_STATUS_MODIFIED:
 412                 case DIFF_STATUS_ADDED:
 413                         /*
 414                          * Links refer to objects in another repositories;
 415                          * output the SHA-1 verbatim.
 416                          */
 417                         if (no_data || S_ISGITLINK(spec->mode))
 418                                 printf("M %06o %s ", spec->mode,
 419                                        oid_to_hex(anonymize ?
 420                                                   anonymize_oid(&spec->oid) :
 421                                                   &spec->oid));
 422                         else {
 423                                 struct object *object = lookup_object(the_repository,
 424                                                                       spec->oid.hash);
 425                                 printf("M %06o :%d ", spec->mode,
 426                                        get_object_mark(object));
 427                         }
 428                         print_path(spec->path);
 429                         string_list_insert(changed, spec->path);
 430                         putchar('\n');
 431                         break;
 432
 433                 default:
 434                         die("Unexpected comparison status '%c' for %s, %s",
 435                                 q->queue[i]->status,
 436                                 ospec->path ? ospec->path : "none",
 437                                 spec->path ? spec->path : "none");
 438                 }
 439         }
 440 }
 441
 442 static const char *find_encoding(const char *begin, const char *end)
 443 {
 444         const char *needle = "\nencoding ";
 445         char *bol, *eol;
 446
 447         bol = memmem(begin, end ? end - begin : strlen(begin),
 448                      needle, strlen(needle));
 449         if (!bol)
 450                 return git_commit_encoding;
 451         bol += strlen(needle);
 452         eol = strchrnul(bol, '\n');
 453         *eol = '\0';
 454         return bol;
 455 }
 456
 457 static void *anonymize_ref_component(const void *old, size_t *len)
 458 {
 459         static int counter;
 460         struct strbuf out = STRBUF_INIT;
 461         strbuf_addf(&out, "ref%d", counter++);
 462         return strbuf_detach(&out, len);
 463 }
 464
 465 static const char *anonymize_refname(const char *refname)
 466 {
 467         /*
 468          * If any of these prefixes is found, we will leave it intact
 469          * so that tags remain tags and so forth.
 470          */
 471         static const char *prefixes[] = {
 472                 "refs/heads/",
 473                 "refs/tags/",
 474                 "refs/remotes/",
 475                 "refs/"
 476         };
 477         static struct hashmap refs;
 478         static struct strbuf anon = STRBUF_INIT;
 479         int i;
 480
 481         /*
 482          * We also leave "master" as a special case, since it does not reveal
 483          * anything interesting.
 484          */
 485         if (!strcmp(refname, "refs/heads/master"))
 486                 return refname;
 487
 488         strbuf_reset(&anon);
 489         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 490                 if (skip_prefix(refname, prefixes[i], &refname)) {
 491                         strbuf_addstr(&anon, prefixes[i]);
 492                         break;
 493                 }
 494         }
 495
 496         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 497         return anon.buf;
 498 }
 499
 500 /*
 501  * We do not even bother to cache commit messages, as they are unlikely
 502  * to be repeated verbatim, and it is not that interesting when they are.
 503  */
 504 static char *anonymize_commit_message(const char *old)
 505 {
 506         static int counter;
 507         return xstrfmt("subject %d\n\nbody\n", counter++);
 508 }
 509
 510 static struct hashmap idents;
 511 static void *anonymize_ident(const void *old, size_t *len)
 512 {
 513         static int counter;
 514         struct strbuf out = STRBUF_INIT;
 515         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 516         counter++;
 517         return strbuf_detach(&out, len);
 518 }
 519
 520 /*
 521  * Our strategy here is to anonymize the names and email addresses,
 522  * but keep timestamps intact, as they influence things like traversal
 523  * order (and by themselves should not be too revealing).
 524  */
 525 static void anonymize_ident_line(const char **beg, const char **end)
 526 {
 527         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 528         static unsigned which_buffer;
 529
 530         struct strbuf *out;
 531         struct ident_split split;
 532         const char *end_of_header;
 533
 534         out = &buffers[which_buffer++];
 535         which_buffer %= ARRAY_SIZE(buffers);
 536         strbuf_reset(out);
 537
 538         /* skip "committer", "author", "tagger", etc */
 539         end_of_header = strchr(*beg, ' ');
 540         if (!end_of_header)
 541                 BUG("malformed line fed to anonymize_ident_line: %.*s",
 542                     (int)(*end - *beg), *beg);
 543         end_of_header++;
 544         strbuf_add(out, *beg, end_of_header - *beg);
 545
 546         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 547             split.date_begin) {
 548                 const char *ident;
 549                 size_t len;
 550
 551                 len = split.mail_end - split.name_begin;
 552                 ident = anonymize_mem(&idents, anonymize_ident,
 553                                       split.name_begin, &len);
 554                 strbuf_add(out, ident, len);
 555                 strbuf_addch(out, ' ');
 556                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 557         } else {
 558                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 559         }
 560
 561         *beg = out->buf;
 562         *end = out->buf + out->len;
 563 }
 564
 565 static void handle_commit(struct commit *commit, struct rev_info *rev,
 566                           struct string_list *paths_of_changed_objects)
 567 {
 568         int saved_output_format = rev->diffopt.output_format;
 569         const char *commit_buffer;
 570         const char *author, *author_end, *committer, *committer_end;
 571         const char *encoding, *message;
 572         char *reencoded = NULL;
 573         struct commit_list *p;
 574         const char *refname;
 575         int i;
 576
 577         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 578
 579         parse_commit_or_die(commit);
 580         commit_buffer = get_commit_buffer(commit, NULL);
 581         author = strstr(commit_buffer, "\nauthor ");
 582         if (!author)
 583                 die("could not find author in commit %s",
 584                     oid_to_hex(&commit->object.oid));
 585         author++;
 586         author_end = strchrnul(author, '\n');
 587         committer = strstr(author_end, "\ncommitter ");
 588         if (!committer)
 589                 die("could not find committer in commit %s",
 590                     oid_to_hex(&commit->object.oid));
 591         committer++;
 592         committer_end = strchrnul(committer, '\n');
 593         message = strstr(committer_end, "\n\n");
 594         encoding = find_encoding(committer_end, message);
 595         if (message)
 596                 message += 2;
 597
 598         if (commit->parents &&
 599             get_object_mark(&commit->parents->item->object) != 0 &&
 600             !full_tree) {
 601                 parse_commit_or_die(commit->parents->item);
 602                 diff_tree_oid(get_commit_tree_oid(commit->parents->item),
 603                               get_commit_tree_oid(commit), "", &rev->diffopt);
 604         }
 605         else
 606                 diff_root_tree_oid(get_commit_tree_oid(commit),
 607                                    "", &rev->diffopt);
 608
 609         /* Export the referenced blobs, and remember the marks. */
 610         for (i = 0; i < diff_queued_diff.nr; i++)
 611                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 612                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 613
 614         refname = *revision_sources_at(&revision_sources, commit);
 615         if (anonymize) {
 616                 refname = anonymize_refname(refname);
 617                 anonymize_ident_line(&committer, &committer_end);
 618                 anonymize_ident_line(&author, &author_end);
 619         }
 620
 621         mark_next_object(&commit->object);
 622         if (anonymize)
 623                 reencoded = anonymize_commit_message(message);
 624         else if (!is_encoding_utf8(encoding))
 625                 reencoded = reencode_string(message, "UTF-8", encoding);
 626         if (!commit->parents)
 627                 printf("reset %s\n", refname);
 628         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
 629                refname, last_idnum,
 630                (int)(author_end - author), author,
 631                (int)(committer_end - committer), committer,
 632                (unsigned)(reencoded
 633                           ? strlen(reencoded) : message
 634                           ? strlen(message) : 0),
 635                reencoded ? reencoded : message ? message : "");
 636         free(reencoded);
 637         unuse_commit_buffer(commit, commit_buffer);
 638
 639         for (i = 0, p = commit->parents; p; p = p->next) {
 640                 int mark = get_object_mark(&p->item->object);
 641                 if (!mark)
 642                         continue;
 643                 if (i == 0)
 644                         printf("from :%d\n", mark);
 645                 else
 646                         printf("merge :%d\n", mark);
 647                 i++;
 648         }
 649
 650         if (full_tree)
 651                 printf("deleteall\n");
 652         log_tree_diff_flush(rev);
 653         string_list_clear(paths_of_changed_objects, 0);
 654         rev->diffopt.output_format = saved_output_format;
 655
 656         printf("\n");
 657
 658         show_progress();
 659 }
 660
 661 static void *anonymize_tag(const void *old, size_t *len)
 662 {
 663         static int counter;
 664         struct strbuf out = STRBUF_INIT;
 665         strbuf_addf(&out, "tag message %d", counter++);
 666         return strbuf_detach(&out, len);
 667 }
 668
 669 static void handle_tail(struct object_array *commits, struct rev_info *revs,
 670                         struct string_list *paths_of_changed_objects)
 671 {
 672         struct commit *commit;
 673         while (commits->nr) {
 674                 commit = (struct commit *)object_array_pop(commits);
 675                 if (has_unshown_parent(commit)) {
 676                         /* Queue again, to be handled later */
 677                         add_object_array(&commit->object, NULL, commits);
 678                         return;
 679                 }
 680                 handle_commit(commit, revs, paths_of_changed_objects);
 681         }
 682 }
 683
 684 static void handle_tag(const char *name, struct tag *tag)
 685 {
 686         unsigned long size;
 687         enum object_type type;
 688         char *buf;
 689         const char *tagger, *tagger_end, *message;
 690         size_t message_size = 0;
 691         struct object *tagged;
 692         int tagged_mark;
 693         struct commit *p;
 694
 695         /* Trees have no identifier in fast-export output, thus we have no way
 696          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 697          * such tags.
 698          */
 699         tagged = tag->tagged;
 700         while (tagged->type == OBJ_TAG) {
 701                 tagged = ((struct tag *)tagged)->tagged;
 702         }
 703         if (tagged->type == OBJ_TREE) {
 704                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 705                         oid_to_hex(&tag->object.oid));
 706                 return;
 707         }
 708
 709         buf = read_object_file(&tag->object.oid, &type, &size);
 710         if (!buf)
 711                 die("could not read tag %s", oid_to_hex(&tag->object.oid));
 712         message = memmem(buf, size, "\n\n", 2);
 713         if (message) {
 714                 message += 2;
 715                 message_size = strlen(message);
 716         }
 717         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 718         if (!tagger) {
 719                 if (fake_missing_tagger)
 720                         tagger = "tagger Unspecified Tagger "
 721                                 "<unspecified-tagger> 0 +0000";
 722                 else
 723                         tagger = "";
 724                 tagger_end = tagger + strlen(tagger);
 725         } else {
 726                 tagger++;
 727                 tagger_end = strchrnul(tagger, '\n');
 728                 if (anonymize)
 729                         anonymize_ident_line(&tagger, &tagger_end);
 730         }
 731
 732         if (anonymize) {
 733                 name = anonymize_refname(name);
 734                 if (message) {
 735                         static struct hashmap tags;
 736                         message = anonymize_mem(&tags, anonymize_tag,
 737                                                 message, &message_size);
 738                 }
 739         }
 740
 741         /* handle signed tags */
 742         if (message) {
 743                 const char *signature = strstr(message,
 744                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 745                 if (signature)
 746                         switch(signed_tag_mode) {
 747                         case SIGNED_TAG_ABORT:
 748                                 die("encountered signed tag %s; use "
 749                                     "--signed-tags=<mode> to handle it",
 750                                     oid_to_hex(&tag->object.oid));
 751                         case WARN:
 752                                 warning("exporting signed tag %s",
 753                                         oid_to_hex(&tag->object.oid));
 754                                 /* fallthru */
 755                         case VERBATIM:
 756                                 break;
 757                         case WARN_STRIP:
 758                                 warning("stripping signature from tag %s",
 759                                         oid_to_hex(&tag->object.oid));
 760                                 /* fallthru */
 761                         case STRIP:
 762                                 message_size = signature + 1 - message;
 763                                 break;
 764                         }
 765         }
 766
 767         /* handle tag->tagged having been filtered out due to paths specified */
 768         tagged = tag->tagged;
 769         tagged_mark = get_object_mark(tagged);
 770         if (!tagged_mark) {
 771                 switch(tag_of_filtered_mode) {
 772                 case TAG_FILTERING_ABORT:
 773                         die("tag %s tags unexported object; use "
 774                             "--tag-of-filtered-object=<mode> to handle it",
 775                             oid_to_hex(&tag->object.oid));
 776                 case DROP:
 777                         /* Ignore this tag altogether */
 778                         free(buf);
 779                         return;
 780                 case REWRITE:
 781                         if (tagged->type != OBJ_COMMIT) {
 782                                 die("tag %s tags unexported %s!",
 783                                     oid_to_hex(&tag->object.oid),
 784                                     type_name(tagged->type));
 785                         }
 786                         p = rewrite_commit((struct commit *)tagged);
 787                         if (!p) {
 788                                 printf("reset %s\nfrom %s\n\n",
 789                                        name, oid_to_hex(&null_oid));
 790                                 free(buf);
 791                                 return;
 792                         }
 793                         tagged_mark = get_object_mark(&p->object);
 794                 }
 795         }
 796
 797         if (starts_with(name, "refs/tags/"))
 798                 name += 10;
 799         printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
 800                name, tagged_mark,
 801                (int)(tagger_end - tagger), tagger,
 802                tagger == tagger_end ? "" : "\n",
 803                (int)message_size, (int)message_size, message ? message : "");
 804         free(buf);
 805 }
 806
 807 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 808 {
 809         switch (e->item->type) {
 810         case OBJ_COMMIT:
 811                 return (struct commit *)e->item;
 812         case OBJ_TAG: {
 813                 struct tag *tag = (struct tag *)e->item;
 814
 815                 /* handle nested tags */
 816                 while (tag && tag->object.type == OBJ_TAG) {
 817                         parse_object(the_repository, &tag->object.oid);
 818                         string_list_append(&extra_refs, full_name)->util = tag;
 819                         tag = (struct tag *)tag->tagged;
 820                 }
 821                 if (!tag)
 822                         die("Tag %s points nowhere?", e->name);
 823                 return (struct commit *)tag;
 824                 break;
 825         }
 826         default:
 827                 return NULL;
 828         }
 829 }
 830
 831 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 832 {
 833         int i;
 834
 835         for (i = 0; i < info->nr; i++) {
 836                 struct rev_cmdline_entry *e = info->rev + i;
 837                 struct object_id oid;
 838                 struct commit *commit;
 839                 char *full_name;
 840
 841                 if (e->flags & UNINTERESTING)
 842                         continue;
 843
 844                 if (dwim_ref(e->name, strlen(e->name), &oid, &full_name) != 1)
 845                         continue;
 846
 847                 if (refspecs.nr) {
 848                         char *private;
 849                         private = apply_refspecs(&refspecs, full_name);
 850                         if (private) {
 851                                 free(full_name);
 852                                 full_name = private;
 853                         }
 854                 }
 855
 856                 commit = get_commit(e, full_name);
 857                 if (!commit) {
 858                         warning("%s: Unexpected object of type %s, skipping.",
 859                                 e->name,
 860                                 type_name(e->item->type));
 861                         continue;
 862                 }
 863
 864                 switch(commit->object.type) {
 865                 case OBJ_COMMIT:
 866                         break;
 867                 case OBJ_BLOB:
 868                         export_blob(&commit->object.oid);
 869                         continue;
 870                 default: /* OBJ_TAG (nested tags) is already handled */
 871                         warning("Tag points to object of unexpected type %s, skipping.",
 872                                 type_name(commit->object.type));
 873                         continue;
 874                 }
 875
 876                 /*
 877                  * This ref will not be updated through a commit, lets make
 878                  * sure it gets properly updated eventually.
 879                  */
 880                 if (*revision_sources_at(&revision_sources, commit) ||
 881                     commit->object.flags & SHOWN)
 882                         string_list_append(&extra_refs, full_name)->util = commit;
 883                 if (!*revision_sources_at(&revision_sources, commit))
 884                         *revision_sources_at(&revision_sources, commit) = full_name;
 885         }
 886 }
 887
 888 static void handle_tags_and_duplicates(void)
 889 {
 890         struct commit *commit;
 891         int i;
 892
 893         for (i = extra_refs.nr - 1; i >= 0; i--) {
 894                 const char *name = extra_refs.items[i].string;
 895                 struct object *object = extra_refs.items[i].util;
 896                 switch (object->type) {
 897                 case OBJ_TAG:
 898                         handle_tag(name, (struct tag *)object);
 899                         break;
 900                 case OBJ_COMMIT:
 901                         if (anonymize)
 902                                 name = anonymize_refname(name);
 903                         /* create refs pointing to already seen commits */
 904                         commit = (struct commit *)object;
 905                         printf("reset %s\nfrom :%d\n\n", name,
 906                                get_object_mark(&commit->object));
 907                         show_progress();
 908                         break;
 909                 }
 910         }
 911 }
 912
 913 static void export_marks(char *file)
 914 {
 915         unsigned int i;
 916         uint32_t mark;
 917         struct decoration_entry *deco = idnums.entries;
 918         FILE *f;
 919         int e = 0;
 920
 921         f = fopen_for_writing(file);
 922         if (!f)
 923                 die_errno("Unable to open marks file %s for writing.", file);
 924
 925         for (i = 0; i < idnums.size; i++) {
 926                 if (deco->base && deco->base->type == 1) {
 927                         mark = ptr_to_mark(deco->decoration);
 928                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
 929                                 oid_to_hex(&deco->base->oid)) < 0) {
 930                             e = 1;
 931                             break;
 932                         }
 933                 }
 934                 deco++;
 935         }
 936
 937         e |= ferror(f);
 938         e |= fclose(f);
 939         if (e)
 940                 error("Unable to write marks file %s.", file);
 941 }
 942
 943 static void import_marks(char *input_file)
 944 {
 945         char line[512];
 946         FILE *f = xfopen(input_file, "r");
 947
 948         while (fgets(line, sizeof(line), f)) {
 949                 uint32_t mark;
 950                 char *line_end, *mark_end;
 951                 struct object_id oid;
 952                 struct object *object;
 953                 struct commit *commit;
 954                 enum object_type type;
 955
 956                 line_end = strchr(line, '\n');
 957                 if (line[0] != ':' || !line_end)
 958                         die("corrupt mark line: %s", line);
 959                 *line_end = '\0';
 960
 961                 mark = strtoumax(line + 1, &mark_end, 10);
 962                 if (!mark || mark_end == line + 1
 963                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
 964                         die("corrupt mark line: %s", line);
 965
 966                 if (last_idnum < mark)
 967                         last_idnum = mark;
 968
 969                 type = oid_object_info(the_repository, &oid, NULL);
 970                 if (type < 0)
 971                         die("object not found: %s", oid_to_hex(&oid));
 972
 973                 if (type != OBJ_COMMIT)
 974                         /* only commits */
 975                         continue;
 976
 977                 commit = lookup_commit(the_repository, &oid);
 978                 if (!commit)
 979                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
 980
 981                 object = &commit->object;
 982
 983                 if (object->flags & SHOWN)
 984                         error("Object %s already has a mark", oid_to_hex(&oid));
 985
 986                 mark_object(object, mark);
 987
 988                 object->flags |= SHOWN;
 989         }
 990         fclose(f);
 991 }
 992
 993 static void handle_deletes(void)
 994 {
 995         int i;
 996         for (i = 0; i < refspecs.nr; i++) {
 997                 struct refspec_item *refspec = &refspecs.items[i];
 998                 if (*refspec->src)
 999                         continue;
1000
1001                 printf("reset %s\nfrom %s\n\n",
1002                                 refspec->dst, oid_to_hex(&null_oid));
1003         }
1004 }
1005
1006 int cmd_fast_export(int argc, const char **argv, const char *prefix)
1007 {
1008         struct rev_info revs;
1009         struct object_array commits = OBJECT_ARRAY_INIT;
1010         struct commit *commit;
1011         char *export_filename = NULL, *import_filename = NULL;
1012         uint32_t lastimportid;
1013         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
1014         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
1015         struct option options[] = {
1016                 OPT_INTEGER(0, "progress", &progress,
1017                             N_("show progress after <n> objects")),
1018                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1019                              N_("select handling of signed tags"),
1020                              parse_opt_signed_tag_mode),
1021                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1022                              N_("select handling of tags that tag filtered objects"),
1023                              parse_opt_tag_of_filtered_mode),
1024                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1025                              N_("Dump marks to this file")),
1026                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1027                              N_("Import marks from this file")),
1028                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1029                          N_("Fake a tagger when tags lack one")),
1030                 OPT_BOOL(0, "full-tree", &full_tree,
1031                          N_("Output full tree for each commit")),
1032                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1033                              N_("Use the done feature to terminate the stream")),
1034                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1035                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1036                              N_("Apply refspec to exported refs")),
1037                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1038                 OPT_END()
1039         };
1040
1041         if (argc == 1)
1042                 usage_with_options (fast_export_usage, options);
1043
1044         /* we handle encodings */
1045         git_config(git_default_config, NULL);
1046
1047         repo_init_revisions(the_repository, &revs, prefix);
1048         init_revision_sources(&revision_sources);
1049         revs.topo_order = 1;
1050         revs.sources = &revision_sources;
1051         revs.rewrite_parents = 1;
1052         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1053                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1054         argc = setup_revisions(argc, argv, &revs, NULL);
1055         if (argc > 1)
1056                 usage_with_options (fast_export_usage, options);
1057
1058         if (refspecs_list.nr) {
1059                 int i;
1060
1061                 for (i = 0; i < refspecs_list.nr; i++)
1062                         refspec_append(&refspecs, refspecs_list.items[i].string);
1063
1064                 string_list_clear(&refspecs_list, 1);
1065         }
1066
1067         if (use_done_feature)
1068                 printf("feature done\n");
1069
1070         if (import_filename)
1071                 import_marks(import_filename);
1072         lastimportid = last_idnum;
1073
1074         if (import_filename && revs.prune_data.nr)
1075                 full_tree = 1;
1076
1077         get_tags_and_duplicates(&revs.cmdline);
1078
1079         if (prepare_revision_walk(&revs))
1080                 die("revision walk setup failed");
1081         revs.diffopt.format_callback = show_filemodify;
1082         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1083         revs.diffopt.flags.recursive = 1;
1084         while ((commit = get_revision(&revs))) {
1085                 if (has_unshown_parent(commit)) {
1086                         add_object_array(&commit->object, NULL, &commits);
1087                 }
1088                 else {
1089                         handle_commit(commit, &revs, &paths_of_changed_objects);
1090                         handle_tail(&commits, &revs, &paths_of_changed_objects);
1091                 }
1092         }
1093
1094         handle_tags_and_duplicates();
1095         handle_deletes();
1096
1097         if (export_filename && lastimportid != last_idnum)
1098                 export_marks(export_filename);
1099
1100         if (use_done_feature)
1101                 printf("done\n");
1102
1103         refspec_clear(&refspecs);
1104
1105         return 0;
1106 }