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 "refs.h"
   9 #include "commit.h"
  10 #include "object.h"
  11 #include "tag.h"
  12 #include "diff.h"
  13 #include "diffcore.h"
  14 #include "log-tree.h"
  15 #include "revision.h"
  16 #include "decorate.h"
  17 #include "string-list.h"
  18 #include "utf8.h"
  19 #include "parse-options.h"
  20 #include "quote.h"
  21 #include "remote.h"
  22 #include "blob.h"
  23
  24 static const char *fast_export_usage[] = {
  25         N_("git fast-export [rev-list-opts]"),
  26         NULL
  27 };
  28
  29 static int progress;
  30 static enum { ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = ABORT;
  31 static enum { ERROR, DROP, REWRITE } tag_of_filtered_mode = ERROR;
  32 static int fake_missing_tagger;
  33 static int use_done_feature;
  34 static int no_data;
  35 static int full_tree;
  36 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  37 static struct refspec *refspecs;
  38 static int refspecs_nr;
  39 static int anonymize;
  40
  41 static int parse_opt_signed_tag_mode(const struct option *opt,
  42                                      const char *arg, int unset)
  43 {
  44         if (unset || !strcmp(arg, "abort"))
  45                 signed_tag_mode = ABORT;
  46         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  47                 signed_tag_mode = VERBATIM;
  48         else if (!strcmp(arg, "warn"))
  49                 signed_tag_mode = WARN;
  50         else if (!strcmp(arg, "warn-strip"))
  51                 signed_tag_mode = WARN_STRIP;
  52         else if (!strcmp(arg, "strip"))
  53                 signed_tag_mode = STRIP;
  54         else
  55                 return error("Unknown signed-tags mode: %s", arg);
  56         return 0;
  57 }
  58
  59 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  60                                           const char *arg, int unset)
  61 {
  62         if (unset || !strcmp(arg, "abort"))
  63                 tag_of_filtered_mode = ERROR;
  64         else if (!strcmp(arg, "drop"))
  65                 tag_of_filtered_mode = DROP;
  66         else if (!strcmp(arg, "rewrite"))
  67                 tag_of_filtered_mode = REWRITE;
  68         else
  69                 return error("Unknown tag-of-filtered mode: %s", arg);
  70         return 0;
  71 }
  72
  73 static struct decoration idnums;
  74 static uint32_t last_idnum;
  75
  76 static int has_unshown_parent(struct commit *commit)
  77 {
  78         struct commit_list *parent;
  79
  80         for (parent = commit->parents; parent; parent = parent->next)
  81                 if (!(parent->item->object.flags & SHOWN) &&
  82                     !(parent->item->object.flags & UNINTERESTING))
  83                         return 1;
  84         return 0;
  85 }
  86
  87 struct anonymized_entry {
  88         struct hashmap_entry hash;
  89         const char *orig;
  90         size_t orig_len;
  91         const char *anon;
  92         size_t anon_len;
  93 };
  94
  95 static int anonymized_entry_cmp(const void *va, const void *vb,
  96                                 const void *data)
  97 {
  98         const struct anonymized_entry *a = va, *b = vb;
  99         return a->orig_len != b->orig_len ||
 100                 memcmp(a->orig, b->orig, a->orig_len);
 101 }
 102
 103 /*
 104  * Basically keep a cache of X->Y so that we can repeatedly replace
 105  * the same anonymized string with another. The actual generation
 106  * is farmed out to the generate function.
 107  */
 108 static const void *anonymize_mem(struct hashmap *map,
 109                                  void *(*generate)(const void *, size_t *),
 110                                  const void *orig, size_t *len)
 111 {
 112         struct anonymized_entry key, *ret;
 113
 114         if (!map->cmpfn)
 115                 hashmap_init(map, anonymized_entry_cmp, 0);
 116
 117         hashmap_entry_init(&key, memhash(orig, *len));
 118         key.orig = orig;
 119         key.orig_len = *len;
 120         ret = hashmap_get(map, &key, NULL);
 121
 122         if (!ret) {
 123                 ret = xmalloc(sizeof(*ret));
 124                 hashmap_entry_init(&ret->hash, key.hash.hash);
 125                 ret->orig = xstrdup(orig);
 126                 ret->orig_len = *len;
 127                 ret->anon = generate(orig, len);
 128                 ret->anon_len = *len;
 129                 hashmap_put(map, ret);
 130         }
 131
 132         *len = ret->anon_len;
 133         return ret->anon;
 134 }
 135
 136 /*
 137  * We anonymize each component of a path individually,
 138  * so that paths a/b and a/c will share a common root.
 139  * The paths are cached via anonymize_mem so that repeated
 140  * lookups for "a" will yield the same value.
 141  */
 142 static void anonymize_path(struct strbuf *out, const char *path,
 143                            struct hashmap *map,
 144                            void *(*generate)(const void *, size_t *))
 145 {
 146         while (*path) {
 147                 const char *end_of_component = strchrnul(path, '/');
 148                 size_t len = end_of_component - path;
 149                 const char *c = anonymize_mem(map, generate, path, &len);
 150                 strbuf_add(out, c, len);
 151                 path = end_of_component;
 152                 if (*path)
 153                         strbuf_addch(out, *path++);
 154         }
 155 }
 156
 157 /* Since intptr_t is C99, we do not use it here */
 158 static inline uint32_t *mark_to_ptr(uint32_t mark)
 159 {
 160         return ((uint32_t *)NULL) + mark;
 161 }
 162
 163 static inline uint32_t ptr_to_mark(void * mark)
 164 {
 165         return (uint32_t *)mark - (uint32_t *)NULL;
 166 }
 167
 168 static inline void mark_object(struct object *object, uint32_t mark)
 169 {
 170         add_decoration(&idnums, object, mark_to_ptr(mark));
 171 }
 172
 173 static inline void mark_next_object(struct object *object)
 174 {
 175         mark_object(object, ++last_idnum);
 176 }
 177
 178 static int get_object_mark(struct object *object)
 179 {
 180         void *decoration = lookup_decoration(&idnums, object);
 181         if (!decoration)
 182                 return 0;
 183         return ptr_to_mark(decoration);
 184 }
 185
 186 static void show_progress(void)
 187 {
 188         static int counter = 0;
 189         if (!progress)
 190                 return;
 191         if ((++counter % progress) == 0)
 192                 printf("progress %d objects\n", counter);
 193 }
 194
 195 /*
 196  * Ideally we would want some transformation of the blob data here
 197  * that is unreversible, but would still be the same size and have
 198  * the same data relationship to other blobs (so that we get the same
 199  * delta and packing behavior as the original). But the first and last
 200  * requirements there are probably mutually exclusive, so let's take
 201  * the easy way out for now, and just generate arbitrary content.
 202  *
 203  * There's no need to cache this result with anonymize_mem, since
 204  * we already handle blob content caching with marks.
 205  */
 206 static char *anonymize_blob(unsigned long *size)
 207 {
 208         static int counter;
 209         struct strbuf out = STRBUF_INIT;
 210         strbuf_addf(&out, "anonymous blob %d", counter++);
 211         *size = out.len;
 212         return strbuf_detach(&out, NULL);
 213 }
 214
 215 static void export_blob(const struct object_id *oid)
 216 {
 217         unsigned long size;
 218         enum object_type type;
 219         char *buf;
 220         struct object *object;
 221         int eaten;
 222
 223         if (no_data)
 224                 return;
 225
 226         if (is_null_oid(oid))
 227                 return;
 228
 229         object = lookup_object(oid->hash);
 230         if (object && object->flags & SHOWN)
 231                 return;
 232
 233         if (anonymize) {
 234                 buf = anonymize_blob(&size);
 235                 object = (struct object *)lookup_blob(oid->hash);
 236                 eaten = 0;
 237         } else {
 238                 buf = read_sha1_file(oid->hash, &type, &size);
 239                 if (!buf)
 240                         die ("Could not read blob %s", oid_to_hex(oid));
 241                 if (check_sha1_signature(oid->hash, buf, size, typename(type)) < 0)
 242                         die("sha1 mismatch in blob %s", oid_to_hex(oid));
 243                 object = parse_object_buffer(oid->hash, type, size, buf, &eaten);
 244         }
 245
 246         if (!object)
 247                 die("Could not read blob %s", oid_to_hex(oid));
 248
 249         mark_next_object(object);
 250
 251         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
 252         if (size && fwrite(buf, size, 1, stdout) != 1)
 253                 die_errno ("Could not write blob '%s'", oid_to_hex(oid));
 254         printf("\n");
 255
 256         show_progress();
 257
 258         object->flags |= SHOWN;
 259         if (!eaten)
 260                 free(buf);
 261 }
 262
 263 static int depth_first(const void *a_, const void *b_)
 264 {
 265         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 266         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 267         const char *name_a, *name_b;
 268         int len_a, len_b, len;
 269         int cmp;
 270
 271         name_a = a->one ? a->one->path : a->two->path;
 272         name_b = b->one ? b->one->path : b->two->path;
 273
 274         len_a = strlen(name_a);
 275         len_b = strlen(name_b);
 276         len = (len_a < len_b) ? len_a : len_b;
 277
 278         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 279         cmp = memcmp(name_a, name_b, len);
 280         if (cmp)
 281                 return cmp;
 282         cmp = len_b - len_a;
 283         if (cmp)
 284                 return cmp;
 285         /*
 286          * Move 'R'ename entries last so that all references of the file
 287          * appear in the output before it is renamed (e.g., when a file
 288          * was copied and renamed in the same commit).
 289          */
 290         return (a->status == 'R') - (b->status == 'R');
 291 }
 292
 293 static void print_path_1(const char *path)
 294 {
 295         int need_quote = quote_c_style(path, NULL, NULL, 0);
 296         if (need_quote)
 297                 quote_c_style(path, NULL, stdout, 0);
 298         else if (strchr(path, ' '))
 299                 printf("\"%s\"", path);
 300         else
 301                 printf("%s", path);
 302 }
 303
 304 static void *anonymize_path_component(const void *path, size_t *len)
 305 {
 306         static int counter;
 307         struct strbuf out = STRBUF_INIT;
 308         strbuf_addf(&out, "path%d", counter++);
 309         return strbuf_detach(&out, len);
 310 }
 311
 312 static void print_path(const char *path)
 313 {
 314         if (!anonymize)
 315                 print_path_1(path);
 316         else {
 317                 static struct hashmap paths;
 318                 static struct strbuf anon = STRBUF_INIT;
 319
 320                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 321                 print_path_1(anon.buf);
 322                 strbuf_reset(&anon);
 323         }
 324 }
 325
 326 static void *generate_fake_oid(const void *old, size_t *len)
 327 {
 328         static uint32_t counter = 1; /* avoid null sha1 */
 329         unsigned char *out = xcalloc(GIT_SHA1_RAWSZ, 1);
 330         put_be32(out + GIT_SHA1_RAWSZ - 4, counter++);
 331         return out;
 332 }
 333
 334 static const unsigned char *anonymize_sha1(const struct object_id *oid)
 335 {
 336         static struct hashmap sha1s;
 337         size_t len = GIT_SHA1_RAWSZ;
 338         return anonymize_mem(&sha1s, generate_fake_oid, oid, &len);
 339 }
 340
 341 static void show_filemodify(struct diff_queue_struct *q,
 342                             struct diff_options *options, void *data)
 343 {
 344         int i;
 345
 346         /*
 347          * Handle files below a directory first, in case they are all deleted
 348          * and the directory changes to a file or symlink.
 349          */
 350         QSORT(q->queue, q->nr, depth_first);
 351
 352         for (i = 0; i < q->nr; i++) {
 353                 struct diff_filespec *ospec = q->queue[i]->one;
 354                 struct diff_filespec *spec = q->queue[i]->two;
 355
 356                 switch (q->queue[i]->status) {
 357                 case DIFF_STATUS_DELETED:
 358                         printf("D ");
 359                         print_path(spec->path);
 360                         putchar('\n');
 361                         break;
 362
 363                 case DIFF_STATUS_COPIED:
 364                 case DIFF_STATUS_RENAMED:
 365                         printf("%c ", q->queue[i]->status);
 366                         print_path(ospec->path);
 367                         putchar(' ');
 368                         print_path(spec->path);
 369                         putchar('\n');
 370
 371                         if (!oidcmp(&ospec->oid, &spec->oid) &&
 372                             ospec->mode == spec->mode)
 373                                 break;
 374                         /* fallthrough */
 375
 376                 case DIFF_STATUS_TYPE_CHANGED:
 377                 case DIFF_STATUS_MODIFIED:
 378                 case DIFF_STATUS_ADDED:
 379                         /*
 380                          * Links refer to objects in another repositories;
 381                          * output the SHA-1 verbatim.
 382                          */
 383                         if (no_data || S_ISGITLINK(spec->mode))
 384                                 printf("M %06o %s ", spec->mode,
 385                                        sha1_to_hex(anonymize ?
 386                                                    anonymize_sha1(&spec->oid) :
 387                                                    spec->oid.hash));
 388                         else {
 389                                 struct object *object = lookup_object(spec->oid.hash);
 390                                 printf("M %06o :%d ", spec->mode,
 391                                        get_object_mark(object));
 392                         }
 393                         print_path(spec->path);
 394                         putchar('\n');
 395                         break;
 396
 397                 default:
 398                         die("Unexpected comparison status '%c' for %s, %s",
 399                                 q->queue[i]->status,
 400                                 ospec->path ? ospec->path : "none",
 401                                 spec->path ? spec->path : "none");
 402                 }
 403         }
 404 }
 405
 406 static const char *find_encoding(const char *begin, const char *end)
 407 {
 408         const char *needle = "\nencoding ";
 409         char *bol, *eol;
 410
 411         bol = memmem(begin, end ? end - begin : strlen(begin),
 412                      needle, strlen(needle));
 413         if (!bol)
 414                 return git_commit_encoding;
 415         bol += strlen(needle);
 416         eol = strchrnul(bol, '\n');
 417         *eol = '\0';
 418         return bol;
 419 }
 420
 421 static void *anonymize_ref_component(const void *old, size_t *len)
 422 {
 423         static int counter;
 424         struct strbuf out = STRBUF_INIT;
 425         strbuf_addf(&out, "ref%d", counter++);
 426         return strbuf_detach(&out, len);
 427 }
 428
 429 static const char *anonymize_refname(const char *refname)
 430 {
 431         /*
 432          * If any of these prefixes is found, we will leave it intact
 433          * so that tags remain tags and so forth.
 434          */
 435         static const char *prefixes[] = {
 436                 "refs/heads/",
 437                 "refs/tags/",
 438                 "refs/remotes/",
 439                 "refs/"
 440         };
 441         static struct hashmap refs;
 442         static struct strbuf anon = STRBUF_INIT;
 443         int i;
 444
 445         /*
 446          * We also leave "master" as a special case, since it does not reveal
 447          * anything interesting.
 448          */
 449         if (!strcmp(refname, "refs/heads/master"))
 450                 return refname;
 451
 452         strbuf_reset(&anon);
 453         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 454                 if (skip_prefix(refname, prefixes[i], &refname)) {
 455                         strbuf_addstr(&anon, prefixes[i]);
 456                         break;
 457                 }
 458         }
 459
 460         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 461         return anon.buf;
 462 }
 463
 464 /*
 465  * We do not even bother to cache commit messages, as they are unlikely
 466  * to be repeated verbatim, and it is not that interesting when they are.
 467  */
 468 static char *anonymize_commit_message(const char *old)
 469 {
 470         static int counter;
 471         return xstrfmt("subject %d\n\nbody\n", counter++);
 472 }
 473
 474 static struct hashmap idents;
 475 static void *anonymize_ident(const void *old, size_t *len)
 476 {
 477         static int counter;
 478         struct strbuf out = STRBUF_INIT;
 479         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 480         counter++;
 481         return strbuf_detach(&out, len);
 482 }
 483
 484 /*
 485  * Our strategy here is to anonymize the names and email addresses,
 486  * but keep timestamps intact, as they influence things like traversal
 487  * order (and by themselves should not be too revealing).
 488  */
 489 static void anonymize_ident_line(const char **beg, const char **end)
 490 {
 491         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 492         static unsigned which_buffer;
 493
 494         struct strbuf *out;
 495         struct ident_split split;
 496         const char *end_of_header;
 497
 498         out = &buffers[which_buffer++];
 499         which_buffer %= ARRAY_SIZE(buffers);
 500         strbuf_reset(out);
 501
 502         /* skip "committer", "author", "tagger", etc */
 503         end_of_header = strchr(*beg, ' ');
 504         if (!end_of_header)
 505                 die("BUG: malformed line fed to anonymize_ident_line: %.*s",
 506                     (int)(*end - *beg), *beg);
 507         end_of_header++;
 508         strbuf_add(out, *beg, end_of_header - *beg);
 509
 510         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 511             split.date_begin) {
 512                 const char *ident;
 513                 size_t len;
 514
 515                 len = split.mail_end - split.name_begin;
 516                 ident = anonymize_mem(&idents, anonymize_ident,
 517                                       split.name_begin, &len);
 518                 strbuf_add(out, ident, len);
 519                 strbuf_addch(out, ' ');
 520                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 521         } else {
 522                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 523         }
 524
 525         *beg = out->buf;
 526         *end = out->buf + out->len;
 527 }
 528
 529 static void handle_commit(struct commit *commit, struct rev_info *rev)
 530 {
 531         int saved_output_format = rev->diffopt.output_format;
 532         const char *commit_buffer;
 533         const char *author, *author_end, *committer, *committer_end;
 534         const char *encoding, *message;
 535         char *reencoded = NULL;
 536         struct commit_list *p;
 537         const char *refname;
 538         int i;
 539
 540         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 541
 542         parse_commit_or_die(commit);
 543         commit_buffer = get_commit_buffer(commit, NULL);
 544         author = strstr(commit_buffer, "\nauthor ");
 545         if (!author)
 546                 die ("Could not find author in commit %s",
 547                      oid_to_hex(&commit->object.oid));
 548         author++;
 549         author_end = strchrnul(author, '\n');
 550         committer = strstr(author_end, "\ncommitter ");
 551         if (!committer)
 552                 die ("Could not find committer in commit %s",
 553                      oid_to_hex(&commit->object.oid));
 554         committer++;
 555         committer_end = strchrnul(committer, '\n');
 556         message = strstr(committer_end, "\n\n");
 557         encoding = find_encoding(committer_end, message);
 558         if (message)
 559                 message += 2;
 560
 561         if (commit->parents &&
 562             get_object_mark(&commit->parents->item->object) != 0 &&
 563             !full_tree) {
 564                 parse_commit_or_die(commit->parents->item);
 565                 diff_tree_sha1(commit->parents->item->tree->object.oid.hash,
 566                                commit->tree->object.oid.hash, "", &rev->diffopt);
 567         }
 568         else
 569                 diff_root_tree_sha1(commit->tree->object.oid.hash,
 570                                     "", &rev->diffopt);
 571
 572         /* Export the referenced blobs, and remember the marks. */
 573         for (i = 0; i < diff_queued_diff.nr; i++)
 574                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 575                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 576
 577         refname = commit->util;
 578         if (anonymize) {
 579                 refname = anonymize_refname(refname);
 580                 anonymize_ident_line(&committer, &committer_end);
 581                 anonymize_ident_line(&author, &author_end);
 582         }
 583
 584         mark_next_object(&commit->object);
 585         if (anonymize)
 586                 reencoded = anonymize_commit_message(message);
 587         else if (!is_encoding_utf8(encoding))
 588                 reencoded = reencode_string(message, "UTF-8", encoding);
 589         if (!commit->parents)
 590                 printf("reset %s\n", refname);
 591         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
 592                refname, last_idnum,
 593                (int)(author_end - author), author,
 594                (int)(committer_end - committer), committer,
 595                (unsigned)(reencoded
 596                           ? strlen(reencoded) : message
 597                           ? strlen(message) : 0),
 598                reencoded ? reencoded : message ? message : "");
 599         free(reencoded);
 600         unuse_commit_buffer(commit, commit_buffer);
 601
 602         for (i = 0, p = commit->parents; p; p = p->next) {
 603                 int mark = get_object_mark(&p->item->object);
 604                 if (!mark)
 605                         continue;
 606                 if (i == 0)
 607                         printf("from :%d\n", mark);
 608                 else
 609                         printf("merge :%d\n", mark);
 610                 i++;
 611         }
 612
 613         if (full_tree)
 614                 printf("deleteall\n");
 615         log_tree_diff_flush(rev);
 616         rev->diffopt.output_format = saved_output_format;
 617
 618         printf("\n");
 619
 620         show_progress();
 621 }
 622
 623 static void *anonymize_tag(const void *old, size_t *len)
 624 {
 625         static int counter;
 626         struct strbuf out = STRBUF_INIT;
 627         strbuf_addf(&out, "tag message %d", counter++);
 628         return strbuf_detach(&out, len);
 629 }
 630
 631 static void handle_tail(struct object_array *commits, struct rev_info *revs)
 632 {
 633         struct commit *commit;
 634         while (commits->nr) {
 635                 commit = (struct commit *)commits->objects[commits->nr - 1].item;
 636                 if (has_unshown_parent(commit))
 637                         return;
 638                 handle_commit(commit, revs);
 639                 commits->nr--;
 640         }
 641 }
 642
 643 static void handle_tag(const char *name, struct tag *tag)
 644 {
 645         unsigned long size;
 646         enum object_type type;
 647         char *buf;
 648         const char *tagger, *tagger_end, *message;
 649         size_t message_size = 0;
 650         struct object *tagged;
 651         int tagged_mark;
 652         struct commit *p;
 653
 654         /* Trees have no identifier in fast-export output, thus we have no way
 655          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 656          * such tags.
 657          */
 658         tagged = tag->tagged;
 659         while (tagged->type == OBJ_TAG) {
 660                 tagged = ((struct tag *)tagged)->tagged;
 661         }
 662         if (tagged->type == OBJ_TREE) {
 663                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 664                         oid_to_hex(&tag->object.oid));
 665                 return;
 666         }
 667
 668         buf = read_sha1_file(tag->object.oid.hash, &type, &size);
 669         if (!buf)
 670                 die ("Could not read tag %s", oid_to_hex(&tag->object.oid));
 671         message = memmem(buf, size, "\n\n", 2);
 672         if (message) {
 673                 message += 2;
 674                 message_size = strlen(message);
 675         }
 676         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 677         if (!tagger) {
 678                 if (fake_missing_tagger)
 679                         tagger = "tagger Unspecified Tagger "
 680                                 "<unspecified-tagger> 0 +0000";
 681                 else
 682                         tagger = "";
 683                 tagger_end = tagger + strlen(tagger);
 684         } else {
 685                 tagger++;
 686                 tagger_end = strchrnul(tagger, '\n');
 687                 if (anonymize)
 688                         anonymize_ident_line(&tagger, &tagger_end);
 689         }
 690
 691         if (anonymize) {
 692                 name = anonymize_refname(name);
 693                 if (message) {
 694                         static struct hashmap tags;
 695                         message = anonymize_mem(&tags, anonymize_tag,
 696                                                 message, &message_size);
 697                 }
 698         }
 699
 700         /* handle signed tags */
 701         if (message) {
 702                 const char *signature = strstr(message,
 703                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 704                 if (signature)
 705                         switch(signed_tag_mode) {
 706                         case ABORT:
 707                                 die ("Encountered signed tag %s; use "
 708                                      "--signed-tags=<mode> to handle it.",
 709                                      oid_to_hex(&tag->object.oid));
 710                         case WARN:
 711                                 warning ("Exporting signed tag %s",
 712                                          oid_to_hex(&tag->object.oid));
 713                                 /* fallthru */
 714                         case VERBATIM:
 715                                 break;
 716                         case WARN_STRIP:
 717                                 warning ("Stripping signature from tag %s",
 718                                          oid_to_hex(&tag->object.oid));
 719                                 /* fallthru */
 720                         case STRIP:
 721                                 message_size = signature + 1 - message;
 722                                 break;
 723                         }
 724         }
 725
 726         /* handle tag->tagged having been filtered out due to paths specified */
 727         tagged = tag->tagged;
 728         tagged_mark = get_object_mark(tagged);
 729         if (!tagged_mark) {
 730                 switch(tag_of_filtered_mode) {
 731                 case ABORT:
 732                         die ("Tag %s tags unexported object; use "
 733                              "--tag-of-filtered-object=<mode> to handle it.",
 734                              oid_to_hex(&tag->object.oid));
 735                 case DROP:
 736                         /* Ignore this tag altogether */
 737                         free(buf);
 738                         return;
 739                 case REWRITE:
 740                         if (tagged->type != OBJ_COMMIT) {
 741                                 die ("Tag %s tags unexported %s!",
 742                                      oid_to_hex(&tag->object.oid),
 743                                      typename(tagged->type));
 744                         }
 745                         p = (struct commit *)tagged;
 746                         for (;;) {
 747                                 if (p->parents && p->parents->next)
 748                                         break;
 749                                 if (p->object.flags & UNINTERESTING)
 750                                         break;
 751                                 if (!(p->object.flags & TREESAME))
 752                                         break;
 753                                 if (!p->parents)
 754                                         die ("Can't find replacement commit for tag %s\n",
 755                                              oid_to_hex(&tag->object.oid));
 756                                 p = p->parents->item;
 757                         }
 758                         tagged_mark = get_object_mark(&p->object);
 759                 }
 760         }
 761
 762         if (starts_with(name, "refs/tags/"))
 763                 name += 10;
 764         printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
 765                name, tagged_mark,
 766                (int)(tagger_end - tagger), tagger,
 767                tagger == tagger_end ? "" : "\n",
 768                (int)message_size, (int)message_size, message ? message : "");
 769         free(buf);
 770 }
 771
 772 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 773 {
 774         switch (e->item->type) {
 775         case OBJ_COMMIT:
 776                 return (struct commit *)e->item;
 777         case OBJ_TAG: {
 778                 struct tag *tag = (struct tag *)e->item;
 779
 780                 /* handle nested tags */
 781                 while (tag && tag->object.type == OBJ_TAG) {
 782                         parse_object(tag->object.oid.hash);
 783                         string_list_append(&extra_refs, full_name)->util = tag;
 784                         tag = (struct tag *)tag->tagged;
 785                 }
 786                 if (!tag)
 787                         die("Tag %s points nowhere?", e->name);
 788                 return (struct commit *)tag;
 789                 break;
 790         }
 791         default:
 792                 return NULL;
 793         }
 794 }
 795
 796 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 797 {
 798         int i;
 799
 800         for (i = 0; i < info->nr; i++) {
 801                 struct rev_cmdline_entry *e = info->rev + i;
 802                 struct object_id oid;
 803                 struct commit *commit;
 804                 char *full_name;
 805
 806                 if (e->flags & UNINTERESTING)
 807                         continue;
 808
 809                 if (dwim_ref(e->name, strlen(e->name), oid.hash, &full_name) != 1)
 810                         continue;
 811
 812                 if (refspecs) {
 813                         char *private;
 814                         private = apply_refspecs(refspecs, refspecs_nr, full_name);
 815                         if (private) {
 816                                 free(full_name);
 817                                 full_name = private;
 818                         }
 819                 }
 820
 821                 commit = get_commit(e, full_name);
 822                 if (!commit) {
 823                         warning("%s: Unexpected object of type %s, skipping.",
 824                                 e->name,
 825                                 typename(e->item->type));
 826                         continue;
 827                 }
 828
 829                 switch(commit->object.type) {
 830                 case OBJ_COMMIT:
 831                         break;
 832                 case OBJ_BLOB:
 833                         export_blob(&commit->object.oid);
 834                         continue;
 835                 default: /* OBJ_TAG (nested tags) is already handled */
 836                         warning("Tag points to object of unexpected type %s, skipping.",
 837                                 typename(commit->object.type));
 838                         continue;
 839                 }
 840
 841                 /*
 842                  * This ref will not be updated through a commit, lets make
 843                  * sure it gets properly updated eventually.
 844                  */
 845                 if (commit->util || commit->object.flags & SHOWN)
 846                         string_list_append(&extra_refs, full_name)->util = commit;
 847                 if (!commit->util)
 848                         commit->util = full_name;
 849         }
 850 }
 851
 852 static void handle_tags_and_duplicates(void)
 853 {
 854         struct commit *commit;
 855         int i;
 856
 857         for (i = extra_refs.nr - 1; i >= 0; i--) {
 858                 const char *name = extra_refs.items[i].string;
 859                 struct object *object = extra_refs.items[i].util;
 860                 switch (object->type) {
 861                 case OBJ_TAG:
 862                         handle_tag(name, (struct tag *)object);
 863                         break;
 864                 case OBJ_COMMIT:
 865                         if (anonymize)
 866                                 name = anonymize_refname(name);
 867                         /* create refs pointing to already seen commits */
 868                         commit = (struct commit *)object;
 869                         printf("reset %s\nfrom :%d\n\n", name,
 870                                get_object_mark(&commit->object));
 871                         show_progress();
 872                         break;
 873                 }
 874         }
 875 }
 876
 877 static void export_marks(char *file)
 878 {
 879         unsigned int i;
 880         uint32_t mark;
 881         struct object_decoration *deco = idnums.hash;
 882         FILE *f;
 883         int e = 0;
 884
 885         f = fopen_for_writing(file);
 886         if (!f)
 887                 die_errno("Unable to open marks file %s for writing.", file);
 888
 889         for (i = 0; i < idnums.size; i++) {
 890                 if (deco->base && deco->base->type == 1) {
 891                         mark = ptr_to_mark(deco->decoration);
 892                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
 893                                 oid_to_hex(&deco->base->oid)) < 0) {
 894                             e = 1;
 895                             break;
 896                         }
 897                 }
 898                 deco++;
 899         }
 900
 901         e |= ferror(f);
 902         e |= fclose(f);
 903         if (e)
 904                 error("Unable to write marks file %s.", file);
 905 }
 906
 907 static void import_marks(char *input_file)
 908 {
 909         char line[512];
 910         FILE *f = fopen(input_file, "r");
 911         if (!f)
 912                 die_errno("cannot read '%s'", input_file);
 913
 914         while (fgets(line, sizeof(line), f)) {
 915                 uint32_t mark;
 916                 char *line_end, *mark_end;
 917                 struct object_id oid;
 918                 struct object *object;
 919                 struct commit *commit;
 920                 enum object_type type;
 921
 922                 line_end = strchr(line, '\n');
 923                 if (line[0] != ':' || !line_end)
 924                         die("corrupt mark line: %s", line);
 925                 *line_end = '\0';
 926
 927                 mark = strtoumax(line + 1, &mark_end, 10);
 928                 if (!mark || mark_end == line + 1
 929                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
 930                         die("corrupt mark line: %s", line);
 931
 932                 if (last_idnum < mark)
 933                         last_idnum = mark;
 934
 935                 type = sha1_object_info(oid.hash, NULL);
 936                 if (type < 0)
 937                         die("object not found: %s", oid_to_hex(&oid));
 938
 939                 if (type != OBJ_COMMIT)
 940                         /* only commits */
 941                         continue;
 942
 943                 commit = lookup_commit(oid.hash);
 944                 if (!commit)
 945                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
 946
 947                 object = &commit->object;
 948
 949                 if (object->flags & SHOWN)
 950                         error("Object %s already has a mark", oid_to_hex(&oid));
 951
 952                 mark_object(object, mark);
 953
 954                 object->flags |= SHOWN;
 955         }
 956         fclose(f);
 957 }
 958
 959 static void handle_deletes(void)
 960 {
 961         int i;
 962         for (i = 0; i < refspecs_nr; i++) {
 963                 struct refspec *refspec = &refspecs[i];
 964                 if (*refspec->src)
 965                         continue;
 966
 967                 printf("reset %s\nfrom %s\n\n",
 968                                 refspec->dst, sha1_to_hex(null_sha1));
 969         }
 970 }
 971
 972 int cmd_fast_export(int argc, const char **argv, const char *prefix)
 973 {
 974         struct rev_info revs;
 975         struct object_array commits = OBJECT_ARRAY_INIT;
 976         struct commit *commit;
 977         char *export_filename = NULL, *import_filename = NULL;
 978         uint32_t lastimportid;
 979         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
 980         struct option options[] = {
 981                 OPT_INTEGER(0, "progress", &progress,
 982                             N_("show progress after <n> objects")),
 983                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
 984                              N_("select handling of signed tags"),
 985                              parse_opt_signed_tag_mode),
 986                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
 987                              N_("select handling of tags that tag filtered objects"),
 988                              parse_opt_tag_of_filtered_mode),
 989                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
 990                              N_("Dump marks to this file")),
 991                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
 992                              N_("Import marks from this file")),
 993                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
 994                          N_("Fake a tagger when tags lack one")),
 995                 OPT_BOOL(0, "full-tree", &full_tree,
 996                          N_("Output full tree for each commit")),
 997                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
 998                              N_("Use the done feature to terminate the stream")),
 999                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1000                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1001                              N_("Apply refspec to exported refs")),
1002                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1003                 OPT_END()
1004         };
1005
1006         if (argc == 1)
1007                 usage_with_options (fast_export_usage, options);
1008
1009         /* we handle encodings */
1010         git_config(git_default_config, NULL);
1011
1012         init_revisions(&revs, prefix);
1013         revs.topo_order = 1;
1014         revs.show_source = 1;
1015         revs.rewrite_parents = 1;
1016         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1017                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1018         argc = setup_revisions(argc, argv, &revs, NULL);
1019         if (argc > 1)
1020                 usage_with_options (fast_export_usage, options);
1021
1022         if (refspecs_list.nr) {
1023                 const char **refspecs_str;
1024                 int i;
1025
1026                 ALLOC_ARRAY(refspecs_str, refspecs_list.nr);
1027                 for (i = 0; i < refspecs_list.nr; i++)
1028                         refspecs_str[i] = refspecs_list.items[i].string;
1029
1030                 refspecs_nr = refspecs_list.nr;
1031                 refspecs = parse_fetch_refspec(refspecs_nr, refspecs_str);
1032
1033                 string_list_clear(&refspecs_list, 1);
1034                 free(refspecs_str);
1035         }
1036
1037         if (use_done_feature)
1038                 printf("feature done\n");
1039
1040         if (import_filename)
1041                 import_marks(import_filename);
1042         lastimportid = last_idnum;
1043
1044         if (import_filename && revs.prune_data.nr)
1045                 full_tree = 1;
1046
1047         get_tags_and_duplicates(&revs.cmdline);
1048
1049         if (prepare_revision_walk(&revs))
1050                 die("revision walk setup failed");
1051         revs.diffopt.format_callback = show_filemodify;
1052         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
1053         while ((commit = get_revision(&revs))) {
1054                 if (has_unshown_parent(commit)) {
1055                         add_object_array(&commit->object, NULL, &commits);
1056                 }
1057                 else {
1058                         handle_commit(commit, &revs);
1059                         handle_tail(&commits, &revs);
1060                 }
1061         }
1062
1063         handle_tags_and_duplicates();
1064         handle_deletes();
1065
1066         if (export_filename && lastimportid != last_idnum)
1067                 export_marks(export_filename);
1068
1069         if (use_done_feature)
1070                 printf("done\n");
1071
1072         free_refspec(refspecs_nr, refspecs);
1073
1074         return 0;
1075 }