builtin/fast-export.c

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