git.oblomov.eu Git - git/blob - builtin/fast-export.c

   1 /*
   2  * "git fast-export" builtin command
   3  *
   4  * Copyright (C) 2007 Johannes E. Schindelin
   5  */
   6 #include "builtin.h"
   7 #include "cache.h"
   8 #include "config.h"
   9 #include "refs.h"
  10 #include "refspec.h"
  11 #include "object-store.h"
  12 #include "commit.h"
  13 #include "object.h"
  14 #include "tag.h"
  15 #include "diff.h"
  16 #include "diffcore.h"
  17 #include "log-tree.h"
  18 #include "revision.h"
  19 #include "decorate.h"
  20 #include "string-list.h"
  21 #include "utf8.h"
  22 #include "parse-options.h"
  23 #include "quote.h"
  24 #include "remote.h"
  25 #include "blob.h"
  26 #include "commit-slab.h"
  27
  28 static const char *fast_export_usage[] = {
  29         N_("git fast-export [rev-list-opts]"),
  30         NULL
  31 };
  32
  33 static int progress;
  34 static enum { SIGNED_TAG_ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = SIGNED_TAG_ABORT;
  35 static enum { TAG_FILTERING_ABORT, DROP, REWRITE } tag_of_filtered_mode = TAG_FILTERING_ABORT;
  36 static enum { REENCODE_ABORT, REENCODE_YES, REENCODE_NO } reencode_mode = REENCODE_ABORT;
  37 static int fake_missing_tagger;
  38 static int use_done_feature;
  39 static int no_data;
  40 static int full_tree;
  41 static int reference_excluded_commits;
  42 static int show_original_ids;
  43 static int mark_tags;
  44 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  45 static struct string_list tag_refs = STRING_LIST_INIT_NODUP;
  46 static struct refspec refspecs = REFSPEC_INIT_FETCH;
  47 static int anonymize;
  48 static struct hashmap anonymized_seeds;
  49 static struct revision_sources revision_sources;
  50
  51 static int parse_opt_signed_tag_mode(const struct option *opt,
  52                                      const char *arg, int unset)
  53 {
  54         if (unset || !strcmp(arg, "abort"))
  55                 signed_tag_mode = SIGNED_TAG_ABORT;
  56         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  57                 signed_tag_mode = VERBATIM;
  58         else if (!strcmp(arg, "warn"))
  59                 signed_tag_mode = WARN;
  60         else if (!strcmp(arg, "warn-strip"))
  61                 signed_tag_mode = WARN_STRIP;
  62         else if (!strcmp(arg, "strip"))
  63                 signed_tag_mode = STRIP;
  64         else
  65                 return error("Unknown signed-tags mode: %s", arg);
  66         return 0;
  67 }
  68
  69 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  70                                           const char *arg, int unset)
  71 {
  72         if (unset || !strcmp(arg, "abort"))
  73                 tag_of_filtered_mode = TAG_FILTERING_ABORT;
  74         else if (!strcmp(arg, "drop"))
  75                 tag_of_filtered_mode = DROP;
  76         else if (!strcmp(arg, "rewrite"))
  77                 tag_of_filtered_mode = REWRITE;
  78         else
  79                 return error("Unknown tag-of-filtered mode: %s", arg);
  80         return 0;
  81 }
  82
  83 static int parse_opt_reencode_mode(const struct option *opt,
  84                                    const char *arg, int unset)
  85 {
  86         if (unset) {
  87                 reencode_mode = REENCODE_ABORT;
  88                 return 0;
  89         }
  90
  91         switch (git_parse_maybe_bool(arg)) {
  92         case 0:
  93                 reencode_mode = REENCODE_NO;
  94                 break;
  95         case 1:
  96                 reencode_mode = REENCODE_YES;
  97                 break;
  98         default:
  99                 if (!strcasecmp(arg, "abort"))
 100                         reencode_mode = REENCODE_ABORT;
 101                 else
 102                         return error("Unknown reencoding mode: %s", arg);
 103         }
 104
 105         return 0;
 106 }
 107
 108 static struct decoration idnums;
 109 static uint32_t last_idnum;
 110
 111 static int has_unshown_parent(struct commit *commit)
 112 {
 113         struct commit_list *parent;
 114
 115         for (parent = commit->parents; parent; parent = parent->next)
 116                 if (!(parent->item->object.flags & SHOWN) &&
 117                     !(parent->item->object.flags & UNINTERESTING))
 118                         return 1;
 119         return 0;
 120 }
 121
 122 struct anonymized_entry {
 123         struct hashmap_entry hash;
 124         const char *anon;
 125         const char orig[FLEX_ARRAY];
 126 };
 127
 128 struct anonymized_entry_key {
 129         struct hashmap_entry hash;
 130         const char *orig;
 131         size_t orig_len;
 132 };
 133
 134 static int anonymized_entry_cmp(const void *unused_cmp_data,
 135                                 const struct hashmap_entry *eptr,
 136                                 const struct hashmap_entry *entry_or_key,
 137                                 const void *keydata)
 138 {
 139         const struct anonymized_entry *a, *b;
 140
 141         a = container_of(eptr, const struct anonymized_entry, hash);
 142         if (keydata) {
 143                 const struct anonymized_entry_key *key = keydata;
 144                 int equal = !strncmp(a->orig, key->orig, key->orig_len) &&
 145                             !a->orig[key->orig_len];
 146                 return !equal;
 147         }
 148
 149         b = container_of(entry_or_key, const struct anonymized_entry, hash);
 150         return strcmp(a->orig, b->orig);
 151 }
 152
 153 /*
 154  * Basically keep a cache of X->Y so that we can repeatedly replace
 155  * the same anonymized string with another. The actual generation
 156  * is farmed out to the generate function.
 157  */
 158 static const char *anonymize_str(struct hashmap *map,
 159                                  char *(*generate)(void *),
 160                                  const char *orig, size_t len,
 161                                  void *data)
 162 {
 163         struct anonymized_entry_key key;
 164         struct anonymized_entry *ret;
 165
 166         if (!map->cmpfn)
 167                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
 168
 169         hashmap_entry_init(&key.hash, memhash(orig, len));
 170         key.orig = orig;
 171         key.orig_len = len;
 172
 173         /* First check if it's a token the user configured manually... */
 174         if (anonymized_seeds.cmpfn)
 175                 ret = hashmap_get_entry(&anonymized_seeds, &key, hash, &key);
 176         else
 177                 ret = NULL;
 178
 179         /* ...otherwise check if we've already seen it in this context... */
 180         if (!ret)
 181                 ret = hashmap_get_entry(map, &key, hash, &key);
 182
 183         /* ...and finally generate a new mapping if necessary */
 184         if (!ret) {
 185                 FLEX_ALLOC_MEM(ret, orig, orig, len);
 186                 hashmap_entry_init(&ret->hash, key.hash.hash);
 187                 ret->anon = generate(data);
 188                 hashmap_put(map, &ret->hash);
 189         }
 190
 191         return ret->anon;
 192 }
 193
 194 /*
 195  * We anonymize each component of a path individually,
 196  * so that paths a/b and a/c will share a common root.
 197  * The paths are cached via anonymize_mem so that repeated
 198  * lookups for "a" will yield the same value.
 199  */
 200 static void anonymize_path(struct strbuf *out, const char *path,
 201                            struct hashmap *map,
 202                            char *(*generate)(void *))
 203 {
 204         while (*path) {
 205                 const char *end_of_component = strchrnul(path, '/');
 206                 size_t len = end_of_component - path;
 207                 const char *c = anonymize_str(map, generate, path, len, NULL);
 208                 strbuf_addstr(out, c);
 209                 path = end_of_component;
 210                 if (*path)
 211                         strbuf_addch(out, *path++);
 212         }
 213 }
 214
 215 static inline void *mark_to_ptr(uint32_t mark)
 216 {
 217         return (void *)(uintptr_t)mark;
 218 }
 219
 220 static inline uint32_t ptr_to_mark(void * mark)
 221 {
 222         return (uint32_t)(uintptr_t)mark;
 223 }
 224
 225 static inline void mark_object(struct object *object, uint32_t mark)
 226 {
 227         add_decoration(&idnums, object, mark_to_ptr(mark));
 228 }
 229
 230 static inline void mark_next_object(struct object *object)
 231 {
 232         mark_object(object, ++last_idnum);
 233 }
 234
 235 static int get_object_mark(struct object *object)
 236 {
 237         void *decoration = lookup_decoration(&idnums, object);
 238         if (!decoration)
 239                 return 0;
 240         return ptr_to_mark(decoration);
 241 }
 242
 243 static struct commit *rewrite_commit(struct commit *p)
 244 {
 245         for (;;) {
 246                 if (p->parents && p->parents->next)
 247                         break;
 248                 if (p->object.flags & UNINTERESTING)
 249                         break;
 250                 if (!(p->object.flags & TREESAME))
 251                         break;
 252                 if (!p->parents)
 253                         return NULL;
 254                 p = p->parents->item;
 255         }
 256         return p;
 257 }
 258
 259 static void show_progress(void)
 260 {
 261         static int counter = 0;
 262         if (!progress)
 263                 return;
 264         if ((++counter % progress) == 0)
 265                 printf("progress %d objects\n", counter);
 266 }
 267
 268 /*
 269  * Ideally we would want some transformation of the blob data here
 270  * that is unreversible, but would still be the same size and have
 271  * the same data relationship to other blobs (so that we get the same
 272  * delta and packing behavior as the original). But the first and last
 273  * requirements there are probably mutually exclusive, so let's take
 274  * the easy way out for now, and just generate arbitrary content.
 275  *
 276  * There's no need to cache this result with anonymize_mem, since
 277  * we already handle blob content caching with marks.
 278  */
 279 static char *anonymize_blob(unsigned long *size)
 280 {
 281         static int counter;
 282         struct strbuf out = STRBUF_INIT;
 283         strbuf_addf(&out, "anonymous blob %d", counter++);
 284         *size = out.len;
 285         return strbuf_detach(&out, NULL);
 286 }
 287
 288 static void export_blob(const struct object_id *oid)
 289 {
 290         unsigned long size;
 291         enum object_type type;
 292         char *buf;
 293         struct object *object;
 294         int eaten;
 295
 296         if (no_data)
 297                 return;
 298
 299         if (is_null_oid(oid))
 300                 return;
 301
 302         object = lookup_object(the_repository, oid);
 303         if (object && object->flags & SHOWN)
 304                 return;
 305
 306         if (anonymize) {
 307                 buf = anonymize_blob(&size);
 308                 object = (struct object *)lookup_blob(the_repository, oid);
 309                 eaten = 0;
 310         } else {
 311                 buf = read_object_file(oid, &type, &size);
 312                 if (!buf)
 313                         die("could not read blob %s", oid_to_hex(oid));
 314                 if (check_object_signature(the_repository, oid, buf, size,
 315                                            type_name(type)) < 0)
 316                         die("oid mismatch in blob %s", oid_to_hex(oid));
 317                 object = parse_object_buffer(the_repository, oid, type,
 318                                              size, buf, &eaten);
 319         }
 320
 321         if (!object)
 322                 die("Could not read blob %s", oid_to_hex(oid));
 323
 324         mark_next_object(object);
 325
 326         printf("blob\nmark :%"PRIu32"\n", last_idnum);
 327         if (show_original_ids)
 328                 printf("original-oid %s\n", oid_to_hex(oid));
 329         printf("data %"PRIuMAX"\n", (uintmax_t)size);
 330         if (size && fwrite(buf, size, 1, stdout) != 1)
 331                 die_errno("could not write blob '%s'", oid_to_hex(oid));
 332         printf("\n");
 333
 334         show_progress();
 335
 336         object->flags |= SHOWN;
 337         if (!eaten)
 338                 free(buf);
 339 }
 340
 341 static int depth_first(const void *a_, const void *b_)
 342 {
 343         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 344         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 345         const char *name_a, *name_b;
 346         int len_a, len_b, len;
 347         int cmp;
 348
 349         name_a = a->one ? a->one->path : a->two->path;
 350         name_b = b->one ? b->one->path : b->two->path;
 351
 352         len_a = strlen(name_a);
 353         len_b = strlen(name_b);
 354         len = (len_a < len_b) ? len_a : len_b;
 355
 356         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 357         cmp = memcmp(name_a, name_b, len);
 358         if (cmp)
 359                 return cmp;
 360         cmp = len_b - len_a;
 361         if (cmp)
 362                 return cmp;
 363         /*
 364          * Move 'R'ename entries last so that all references of the file
 365          * appear in the output before it is renamed (e.g., when a file
 366          * was copied and renamed in the same commit).
 367          */
 368         return (a->status == 'R') - (b->status == 'R');
 369 }
 370
 371 static void print_path_1(const char *path)
 372 {
 373         int need_quote = quote_c_style(path, NULL, NULL, 0);
 374         if (need_quote)
 375                 quote_c_style(path, NULL, stdout, 0);
 376         else if (strchr(path, ' '))
 377                 printf("\"%s\"", path);
 378         else
 379                 printf("%s", path);
 380 }
 381
 382 static char *anonymize_path_component(void *data)
 383 {
 384         static int counter;
 385         struct strbuf out = STRBUF_INIT;
 386         strbuf_addf(&out, "path%d", counter++);
 387         return strbuf_detach(&out, NULL);
 388 }
 389
 390 static void print_path(const char *path)
 391 {
 392         if (!anonymize)
 393                 print_path_1(path);
 394         else {
 395                 static struct hashmap paths;
 396                 static struct strbuf anon = STRBUF_INIT;
 397
 398                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 399                 print_path_1(anon.buf);
 400                 strbuf_reset(&anon);
 401         }
 402 }
 403
 404 static char *generate_fake_oid(void *data)
 405 {
 406         static uint32_t counter = 1; /* avoid null oid */
 407         const unsigned hashsz = the_hash_algo->rawsz;
 408         struct object_id oid;
 409         char *hex = xmallocz(GIT_MAX_HEXSZ);
 410
 411         oidclr(&oid);
 412         put_be32(oid.hash + hashsz - 4, counter++);
 413         return oid_to_hex_r(hex, &oid);
 414 }
 415
 416 static const char *anonymize_oid(const char *oid_hex)
 417 {
 418         static struct hashmap objs;
 419         size_t len = strlen(oid_hex);
 420         return anonymize_str(&objs, generate_fake_oid, oid_hex, len, NULL);
 421 }
 422
 423 static void show_filemodify(struct diff_queue_struct *q,
 424                             struct diff_options *options, void *data)
 425 {
 426         int i;
 427         struct string_list *changed = data;
 428
 429         /*
 430          * Handle files below a directory first, in case they are all deleted
 431          * and the directory changes to a file or symlink.
 432          */
 433         QSORT(q->queue, q->nr, depth_first);
 434
 435         for (i = 0; i < q->nr; i++) {
 436                 struct diff_filespec *ospec = q->queue[i]->one;
 437                 struct diff_filespec *spec = q->queue[i]->two;
 438
 439                 switch (q->queue[i]->status) {
 440                 case DIFF_STATUS_DELETED:
 441                         printf("D ");
 442                         print_path(spec->path);
 443                         string_list_insert(changed, spec->path);
 444                         putchar('\n');
 445                         break;
 446
 447                 case DIFF_STATUS_COPIED:
 448                 case DIFF_STATUS_RENAMED:
 449                         /*
 450                          * If a change in the file corresponding to ospec->path
 451                          * has been observed, we cannot trust its contents
 452                          * because the diff is calculated based on the prior
 453                          * contents, not the current contents.  So, declare a
 454                          * copy or rename only if there was no change observed.
 455                          */
 456                         if (!string_list_has_string(changed, ospec->path)) {
 457                                 printf("%c ", q->queue[i]->status);
 458                                 print_path(ospec->path);
 459                                 putchar(' ');
 460                                 print_path(spec->path);
 461                                 string_list_insert(changed, spec->path);
 462                                 putchar('\n');
 463
 464                                 if (oideq(&ospec->oid, &spec->oid) &&
 465                                     ospec->mode == spec->mode)
 466                                         break;
 467                         }
 468                         /* fallthrough */
 469
 470                 case DIFF_STATUS_TYPE_CHANGED:
 471                 case DIFF_STATUS_MODIFIED:
 472                 case DIFF_STATUS_ADDED:
 473                         /*
 474                          * Links refer to objects in another repositories;
 475                          * output the SHA-1 verbatim.
 476                          */
 477                         if (no_data || S_ISGITLINK(spec->mode))
 478                                 printf("M %06o %s ", spec->mode,
 479                                        anonymize ?
 480                                        anonymize_oid(oid_to_hex(&spec->oid)) :
 481                                        oid_to_hex(&spec->oid));
 482                         else {
 483                                 struct object *object = lookup_object(the_repository,
 484                                                                       &spec->oid);
 485                                 printf("M %06o :%d ", spec->mode,
 486                                        get_object_mark(object));
 487                         }
 488                         print_path(spec->path);
 489                         string_list_insert(changed, spec->path);
 490                         putchar('\n');
 491                         break;
 492
 493                 default:
 494                         die("Unexpected comparison status '%c' for %s, %s",
 495                                 q->queue[i]->status,
 496                                 ospec->path ? ospec->path : "none",
 497                                 spec->path ? spec->path : "none");
 498                 }
 499         }
 500 }
 501
 502 static const char *find_encoding(const char *begin, const char *end)
 503 {
 504         const char *needle = "\nencoding ";
 505         char *bol, *eol;
 506
 507         bol = memmem(begin, end ? end - begin : strlen(begin),
 508                      needle, strlen(needle));
 509         if (!bol)
 510                 return NULL;
 511         bol += strlen(needle);
 512         eol = strchrnul(bol, '\n');
 513         *eol = '\0';
 514         return bol;
 515 }
 516
 517 static char *anonymize_ref_component(void *data)
 518 {
 519         static int counter;
 520         struct strbuf out = STRBUF_INIT;
 521         strbuf_addf(&out, "ref%d", counter++);
 522         return strbuf_detach(&out, NULL);
 523 }
 524
 525 static const char *anonymize_refname(const char *refname)
 526 {
 527         /*
 528          * If any of these prefixes is found, we will leave it intact
 529          * so that tags remain tags and so forth.
 530          */
 531         static const char *prefixes[] = {
 532                 "refs/heads/",
 533                 "refs/tags/",
 534                 "refs/remotes/",
 535                 "refs/"
 536         };
 537         static struct hashmap refs;
 538         static struct strbuf anon = STRBUF_INIT;
 539         int i;
 540
 541         strbuf_reset(&anon);
 542         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 543                 if (skip_prefix(refname, prefixes[i], &refname)) {
 544                         strbuf_addstr(&anon, prefixes[i]);
 545                         break;
 546                 }
 547         }
 548
 549         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 550         return anon.buf;
 551 }
 552
 553 /*
 554  * We do not even bother to cache commit messages, as they are unlikely
 555  * to be repeated verbatim, and it is not that interesting when they are.
 556  */
 557 static char *anonymize_commit_message(const char *old)
 558 {
 559         static int counter;
 560         return xstrfmt("subject %d\n\nbody\n", counter++);
 561 }
 562
 563 static char *anonymize_ident(void *data)
 564 {
 565         static int counter;
 566         struct strbuf out = STRBUF_INIT;
 567         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 568         counter++;
 569         return strbuf_detach(&out, NULL);
 570 }
 571
 572 /*
 573  * Our strategy here is to anonymize the names and email addresses,
 574  * but keep timestamps intact, as they influence things like traversal
 575  * order (and by themselves should not be too revealing).
 576  */
 577 static void anonymize_ident_line(const char **beg, const char **end)
 578 {
 579         static struct hashmap idents;
 580         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 581         static unsigned which_buffer;
 582
 583         struct strbuf *out;
 584         struct ident_split split;
 585         const char *end_of_header;
 586
 587         out = &buffers[which_buffer++];
 588         which_buffer %= ARRAY_SIZE(buffers);
 589         strbuf_reset(out);
 590
 591         /* skip "committer", "author", "tagger", etc */
 592         end_of_header = strchr(*beg, ' ');
 593         if (!end_of_header)
 594                 BUG("malformed line fed to anonymize_ident_line: %.*s",
 595                     (int)(*end - *beg), *beg);
 596         end_of_header++;
 597         strbuf_add(out, *beg, end_of_header - *beg);
 598
 599         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 600             split.date_begin) {
 601                 const char *ident;
 602                 size_t len;
 603
 604                 len = split.mail_end - split.name_begin;
 605                 ident = anonymize_str(&idents, anonymize_ident,
 606                                       split.name_begin, len, NULL);
 607                 strbuf_addstr(out, ident);
 608                 strbuf_addch(out, ' ');
 609                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 610         } else {
 611                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 612         }
 613
 614         *beg = out->buf;
 615         *end = out->buf + out->len;
 616 }
 617
 618 static void handle_commit(struct commit *commit, struct rev_info *rev,
 619                           struct string_list *paths_of_changed_objects)
 620 {
 621         int saved_output_format = rev->diffopt.output_format;
 622         const char *commit_buffer;
 623         const char *author, *author_end, *committer, *committer_end;
 624         const char *encoding, *message;
 625         char *reencoded = NULL;
 626         struct commit_list *p;
 627         const char *refname;
 628         int i;
 629
 630         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 631
 632         parse_commit_or_die(commit);
 633         commit_buffer = get_commit_buffer(commit, NULL);
 634         author = strstr(commit_buffer, "\nauthor ");
 635         if (!author)
 636                 die("could not find author in commit %s",
 637                     oid_to_hex(&commit->object.oid));
 638         author++;
 639         author_end = strchrnul(author, '\n');
 640         committer = strstr(author_end, "\ncommitter ");
 641         if (!committer)
 642                 die("could not find committer in commit %s",
 643                     oid_to_hex(&commit->object.oid));
 644         committer++;
 645         committer_end = strchrnul(committer, '\n');
 646         message = strstr(committer_end, "\n\n");
 647         encoding = find_encoding(committer_end, message);
 648         if (message)
 649                 message += 2;
 650
 651         if (commit->parents &&
 652             (get_object_mark(&commit->parents->item->object) != 0 ||
 653              reference_excluded_commits) &&
 654             !full_tree) {
 655                 parse_commit_or_die(commit->parents->item);
 656                 diff_tree_oid(get_commit_tree_oid(commit->parents->item),
 657                               get_commit_tree_oid(commit), "", &rev->diffopt);
 658         }
 659         else
 660                 diff_root_tree_oid(get_commit_tree_oid(commit),
 661                                    "", &rev->diffopt);
 662
 663         /* Export the referenced blobs, and remember the marks. */
 664         for (i = 0; i < diff_queued_diff.nr; i++)
 665                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 666                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 667
 668         refname = *revision_sources_at(&revision_sources, commit);
 669         /*
 670          * FIXME: string_list_remove() below for each ref is overall
 671          * O(N^2).  Compared to a history walk and diffing trees, this is
 672          * just lost in the noise in practice.  However, theoretically a
 673          * repo may have enough refs for this to become slow.
 674          */
 675         string_list_remove(&extra_refs, refname, 0);
 676         if (anonymize) {
 677                 refname = anonymize_refname(refname);
 678                 anonymize_ident_line(&committer, &committer_end);
 679                 anonymize_ident_line(&author, &author_end);
 680         }
 681
 682         mark_next_object(&commit->object);
 683         if (anonymize) {
 684                 reencoded = anonymize_commit_message(message);
 685         } else if (encoding) {
 686                 switch(reencode_mode) {
 687                 case REENCODE_YES:
 688                         reencoded = reencode_string(message, "UTF-8", encoding);
 689                         break;
 690                 case REENCODE_NO:
 691                         break;
 692                 case REENCODE_ABORT:
 693                         die("Encountered commit-specific encoding %s in commit "
 694                             "%s; use --reencode=[yes|no] to handle it",
 695                             encoding, oid_to_hex(&commit->object.oid));
 696                 }
 697         }
 698         if (!commit->parents)
 699                 printf("reset %s\n", refname);
 700         printf("commit %s\nmark :%"PRIu32"\n", refname, last_idnum);
 701         if (show_original_ids)
 702                 printf("original-oid %s\n", oid_to_hex(&commit->object.oid));
 703         printf("%.*s\n%.*s\n",
 704                (int)(author_end - author), author,
 705                (int)(committer_end - committer), committer);
 706         if (!reencoded && encoding)
 707                 printf("encoding %s\n", encoding);
 708         printf("data %u\n%s",
 709                (unsigned)(reencoded
 710                           ? strlen(reencoded) : message
 711                           ? strlen(message) : 0),
 712                reencoded ? reencoded : message ? message : "");
 713         free(reencoded);
 714         unuse_commit_buffer(commit, commit_buffer);
 715
 716         for (i = 0, p = commit->parents; p; p = p->next) {
 717                 struct object *obj = &p->item->object;
 718                 int mark = get_object_mark(obj);
 719
 720                 if (!mark && !reference_excluded_commits)
 721                         continue;
 722                 if (i == 0)
 723                         printf("from ");
 724                 else
 725                         printf("merge ");
 726                 if (mark)
 727                         printf(":%d\n", mark);
 728                 else
 729                         printf("%s\n",
 730                                anonymize ?
 731                                anonymize_oid(oid_to_hex(&obj->oid)) :
 732                                oid_to_hex(&obj->oid));
 733                 i++;
 734         }
 735
 736         if (full_tree)
 737                 printf("deleteall\n");
 738         log_tree_diff_flush(rev);
 739         string_list_clear(paths_of_changed_objects, 0);
 740         rev->diffopt.output_format = saved_output_format;
 741
 742         printf("\n");
 743
 744         show_progress();
 745 }
 746
 747 static char *anonymize_tag(void *data)
 748 {
 749         static int counter;
 750         struct strbuf out = STRBUF_INIT;
 751         strbuf_addf(&out, "tag message %d", counter++);
 752         return strbuf_detach(&out, NULL);
 753 }
 754
 755 static void handle_tail(struct object_array *commits, struct rev_info *revs,
 756                         struct string_list *paths_of_changed_objects)
 757 {
 758         struct commit *commit;
 759         while (commits->nr) {
 760                 commit = (struct commit *)object_array_pop(commits);
 761                 if (has_unshown_parent(commit)) {
 762                         /* Queue again, to be handled later */
 763                         add_object_array(&commit->object, NULL, commits);
 764                         return;
 765                 }
 766                 handle_commit(commit, revs, paths_of_changed_objects);
 767         }
 768 }
 769
 770 static void handle_tag(const char *name, struct tag *tag)
 771 {
 772         unsigned long size;
 773         enum object_type type;
 774         char *buf;
 775         const char *tagger, *tagger_end, *message;
 776         size_t message_size = 0;
 777         struct object *tagged;
 778         int tagged_mark;
 779         struct commit *p;
 780
 781         /* Trees have no identifier in fast-export output, thus we have no way
 782          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 783          * such tags.
 784          */
 785         tagged = tag->tagged;
 786         while (tagged->type == OBJ_TAG) {
 787                 tagged = ((struct tag *)tagged)->tagged;
 788         }
 789         if (tagged->type == OBJ_TREE) {
 790                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 791                         oid_to_hex(&tag->object.oid));
 792                 return;
 793         }
 794
 795         buf = read_object_file(&tag->object.oid, &type, &size);
 796         if (!buf)
 797                 die("could not read tag %s", oid_to_hex(&tag->object.oid));
 798         message = memmem(buf, size, "\n\n", 2);
 799         if (message) {
 800                 message += 2;
 801                 message_size = strlen(message);
 802         }
 803         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 804         if (!tagger) {
 805                 if (fake_missing_tagger)
 806                         tagger = "tagger Unspecified Tagger "
 807                                 "<unspecified-tagger> 0 +0000";
 808                 else
 809                         tagger = "";
 810                 tagger_end = tagger + strlen(tagger);
 811         } else {
 812                 tagger++;
 813                 tagger_end = strchrnul(tagger, '\n');
 814                 if (anonymize)
 815                         anonymize_ident_line(&tagger, &tagger_end);
 816         }
 817
 818         if (anonymize) {
 819                 name = anonymize_refname(name);
 820                 if (message) {
 821                         static struct hashmap tags;
 822                         message = anonymize_str(&tags, anonymize_tag,
 823                                                 message, message_size, NULL);
 824                 }
 825         }
 826
 827         /* handle signed tags */
 828         if (message) {
 829                 const char *signature = strstr(message,
 830                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 831                 if (signature)
 832                         switch(signed_tag_mode) {
 833                         case SIGNED_TAG_ABORT:
 834                                 die("encountered signed tag %s; use "
 835                                     "--signed-tags=<mode> to handle it",
 836                                     oid_to_hex(&tag->object.oid));
 837                         case WARN:
 838                                 warning("exporting signed tag %s",
 839                                         oid_to_hex(&tag->object.oid));
 840                                 /* fallthru */
 841                         case VERBATIM:
 842                                 break;
 843                         case WARN_STRIP:
 844                                 warning("stripping signature from tag %s",
 845                                         oid_to_hex(&tag->object.oid));
 846                                 /* fallthru */
 847                         case STRIP:
 848                                 message_size = signature + 1 - message;
 849                                 break;
 850                         }
 851         }
 852
 853         /* handle tag->tagged having been filtered out due to paths specified */
 854         tagged = tag->tagged;
 855         tagged_mark = get_object_mark(tagged);
 856         if (!tagged_mark) {
 857                 switch(tag_of_filtered_mode) {
 858                 case TAG_FILTERING_ABORT:
 859                         die("tag %s tags unexported object; use "
 860                             "--tag-of-filtered-object=<mode> to handle it",
 861                             oid_to_hex(&tag->object.oid));
 862                 case DROP:
 863                         /* Ignore this tag altogether */
 864                         free(buf);
 865                         return;
 866                 case REWRITE:
 867                         if (tagged->type == OBJ_TAG && !mark_tags) {
 868                                 die(_("Error: Cannot export nested tags unless --mark-tags is specified."));
 869                         } else if (tagged->type == OBJ_COMMIT) {
 870                                 p = rewrite_commit((struct commit *)tagged);
 871                                 if (!p) {
 872                                         printf("reset %s\nfrom %s\n\n",
 873                                                name, oid_to_hex(&null_oid));
 874                                         free(buf);
 875                                         return;
 876                                 }
 877                                 tagged_mark = get_object_mark(&p->object);
 878                         } else {
 879                                 /* tagged->type is either OBJ_BLOB or OBJ_TAG */
 880                                 tagged_mark = get_object_mark(tagged);
 881                         }
 882                 }
 883         }
 884
 885         if (tagged->type == OBJ_TAG) {
 886                 printf("reset %s\nfrom %s\n\n",
 887                        name, oid_to_hex(&null_oid));
 888         }
 889         skip_prefix(name, "refs/tags/", &name);
 890         printf("tag %s\n", name);
 891         if (mark_tags) {
 892                 mark_next_object(&tag->object);
 893                 printf("mark :%"PRIu32"\n", last_idnum);
 894         }
 895         if (tagged_mark)
 896                 printf("from :%d\n", tagged_mark);
 897         else
 898                 printf("from %s\n", oid_to_hex(&tagged->oid));
 899
 900         if (show_original_ids)
 901                 printf("original-oid %s\n", oid_to_hex(&tag->object.oid));
 902         printf("%.*s%sdata %d\n%.*s\n",
 903                (int)(tagger_end - tagger), tagger,
 904                tagger == tagger_end ? "" : "\n",
 905                (int)message_size, (int)message_size, message ? message : "");
 906         free(buf);
 907 }
 908
 909 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 910 {
 911         switch (e->item->type) {
 912         case OBJ_COMMIT:
 913                 return (struct commit *)e->item;
 914         case OBJ_TAG: {
 915                 struct tag *tag = (struct tag *)e->item;
 916
 917                 /* handle nested tags */
 918                 while (tag && tag->object.type == OBJ_TAG) {
 919                         parse_object(the_repository, &tag->object.oid);
 920                         string_list_append(&tag_refs, full_name)->util = tag;
 921                         tag = (struct tag *)tag->tagged;
 922                 }
 923                 if (!tag)
 924                         die("Tag %s points nowhere?", e->name);
 925                 return (struct commit *)tag;
 926                 break;
 927         }
 928         default:
 929                 return NULL;
 930         }
 931 }
 932
 933 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 934 {
 935         int i;
 936
 937         for (i = 0; i < info->nr; i++) {
 938                 struct rev_cmdline_entry *e = info->rev + i;
 939                 struct object_id oid;
 940                 struct commit *commit;
 941                 char *full_name;
 942
 943                 if (e->flags & UNINTERESTING)
 944                         continue;
 945
 946                 if (dwim_ref(e->name, strlen(e->name), &oid, &full_name, 0) != 1)
 947                         continue;
 948
 949                 if (refspecs.nr) {
 950                         char *private;
 951                         private = apply_refspecs(&refspecs, full_name);
 952                         if (private) {
 953                                 free(full_name);
 954                                 full_name = private;
 955                         }
 956                 }
 957
 958                 commit = get_commit(e, full_name);
 959                 if (!commit) {
 960                         warning("%s: Unexpected object of type %s, skipping.",
 961                                 e->name,
 962                                 type_name(e->item->type));
 963                         continue;
 964                 }
 965
 966                 switch(commit->object.type) {
 967                 case OBJ_COMMIT:
 968                         break;
 969                 case OBJ_BLOB:
 970                         export_blob(&commit->object.oid);
 971                         continue;
 972                 default: /* OBJ_TAG (nested tags) is already handled */
 973                         warning("Tag points to object of unexpected type %s, skipping.",
 974                                 type_name(commit->object.type));
 975                         continue;
 976                 }
 977
 978                 /*
 979                  * Make sure this ref gets properly updated eventually, whether
 980                  * through a commit or manually at the end.
 981                  */
 982                 if (e->item->type != OBJ_TAG)
 983                         string_list_append(&extra_refs, full_name)->util = commit;
 984
 985                 if (!*revision_sources_at(&revision_sources, commit))
 986                         *revision_sources_at(&revision_sources, commit) = full_name;
 987         }
 988
 989         string_list_sort(&extra_refs);
 990         string_list_remove_duplicates(&extra_refs, 0);
 991 }
 992
 993 static void handle_tags_and_duplicates(struct string_list *extras)
 994 {
 995         struct commit *commit;
 996         int i;
 997
 998         for (i = extras->nr - 1; i >= 0; i--) {
 999                 const char *name = extras->items[i].string;
1000                 struct object *object = extras->items[i].util;
1001                 int mark;
1002
1003                 switch (object->type) {
1004                 case OBJ_TAG:
1005                         handle_tag(name, (struct tag *)object);
1006                         break;
1007                 case OBJ_COMMIT:
1008                         if (anonymize)
1009                                 name = anonymize_refname(name);
1010                         /* create refs pointing to already seen commits */
1011                         commit = rewrite_commit((struct commit *)object);
1012                         if (!commit) {
1013                                 /*
1014                                  * Neither this object nor any of its
1015                                  * ancestors touch any relevant paths, so
1016                                  * it has been filtered to nothing.  Delete
1017                                  * it.
1018                                  */
1019                                 printf("reset %s\nfrom %s\n\n",
1020                                        name, oid_to_hex(&null_oid));
1021                                 continue;
1022                         }
1023
1024                         mark = get_object_mark(&commit->object);
1025                         if (!mark) {
1026                                 /*
1027                                  * Getting here means we have a commit which
1028                                  * was excluded by a negative refspec (e.g.
1029                                  * fast-export ^HEAD HEAD).  If we are
1030                                  * referencing excluded commits, set the ref
1031                                  * to the exact commit.  Otherwise, the user
1032                                  * wants the branch exported but every commit
1033                                  * in its history to be deleted, which basically
1034                                  * just means deletion of the ref.
1035                                  */
1036                                 if (!reference_excluded_commits) {
1037                                         /* delete the ref */
1038                                         printf("reset %s\nfrom %s\n\n",
1039                                                name, oid_to_hex(&null_oid));
1040                                         continue;
1041                                 }
1042                                 /* set ref to commit using oid, not mark */
1043                                 printf("reset %s\nfrom %s\n\n", name,
1044                                        oid_to_hex(&commit->object.oid));
1045                                 continue;
1046                         }
1047
1048                         printf("reset %s\nfrom :%d\n\n", name, mark
1049                                );
1050                         show_progress();
1051                         break;
1052                 }
1053         }
1054 }
1055
1056 static void export_marks(char *file)
1057 {
1058         unsigned int i;
1059         uint32_t mark;
1060         struct decoration_entry *deco = idnums.entries;
1061         FILE *f;
1062         int e = 0;
1063
1064         f = fopen_for_writing(file);
1065         if (!f)
1066                 die_errno("Unable to open marks file %s for writing.", file);
1067
1068         for (i = 0; i < idnums.size; i++) {
1069                 if (deco->base && deco->base->type == 1) {
1070                         mark = ptr_to_mark(deco->decoration);
1071                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
1072                                 oid_to_hex(&deco->base->oid)) < 0) {
1073                             e = 1;
1074                             break;
1075                         }
1076                 }
1077                 deco++;
1078         }
1079
1080         e |= ferror(f);
1081         e |= fclose(f);
1082         if (e)
1083                 error("Unable to write marks file %s.", file);
1084 }
1085
1086 static void import_marks(char *input_file, int check_exists)
1087 {
1088         char line[512];
1089         FILE *f;
1090         struct stat sb;
1091
1092         if (check_exists && stat(input_file, &sb))
1093                 return;
1094
1095         f = xfopen(input_file, "r");
1096         while (fgets(line, sizeof(line), f)) {
1097                 uint32_t mark;
1098                 char *line_end, *mark_end;
1099                 struct object_id oid;
1100                 struct object *object;
1101                 struct commit *commit;
1102                 enum object_type type;
1103
1104                 line_end = strchr(line, '\n');
1105                 if (line[0] != ':' || !line_end)
1106                         die("corrupt mark line: %s", line);
1107                 *line_end = '\0';
1108
1109                 mark = strtoumax(line + 1, &mark_end, 10);
1110                 if (!mark || mark_end == line + 1
1111                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
1112                         die("corrupt mark line: %s", line);
1113
1114                 if (last_idnum < mark)
1115                         last_idnum = mark;
1116
1117                 type = oid_object_info(the_repository, &oid, NULL);
1118                 if (type < 0)
1119                         die("object not found: %s", oid_to_hex(&oid));
1120
1121                 if (type != OBJ_COMMIT)
1122                         /* only commits */
1123                         continue;
1124
1125                 commit = lookup_commit(the_repository, &oid);
1126                 if (!commit)
1127                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
1128
1129                 object = &commit->object;
1130
1131                 if (object->flags & SHOWN)
1132                         error("Object %s already has a mark", oid_to_hex(&oid));
1133
1134                 mark_object(object, mark);
1135
1136                 object->flags |= SHOWN;
1137         }
1138         fclose(f);
1139 }
1140
1141 static void handle_deletes(void)
1142 {
1143         int i;
1144         for (i = 0; i < refspecs.nr; i++) {
1145                 struct refspec_item *refspec = &refspecs.items[i];
1146                 if (*refspec->src)
1147                         continue;
1148
1149                 printf("reset %s\nfrom %s\n\n",
1150                                 refspec->dst, oid_to_hex(&null_oid));
1151         }
1152 }
1153
1154 static char *anonymize_seed(void *data)
1155 {
1156         return xstrdup(data);
1157 }
1158
1159 static int parse_opt_anonymize_map(const struct option *opt,
1160                                    const char *arg, int unset)
1161 {
1162         struct hashmap *map = opt->value;
1163         const char *delim, *value;
1164         size_t keylen;
1165
1166         BUG_ON_OPT_NEG(unset);
1167
1168         delim = strchr(arg, ':');
1169         if (delim) {
1170                 keylen = delim - arg;
1171                 value = delim + 1;
1172         } else {
1173                 keylen = strlen(arg);
1174                 value = arg;
1175         }
1176
1177         if (!keylen || !*value)
1178                 return error(_("--anonymize-map token cannot be empty"));
1179
1180         anonymize_str(map, anonymize_seed, arg, keylen, (void *)value);
1181
1182         return 0;
1183 }
1184
1185 int cmd_fast_export(int argc, const char **argv, const char *prefix)
1186 {
1187         struct rev_info revs;
1188         struct object_array commits = OBJECT_ARRAY_INIT;
1189         struct commit *commit;
1190         char *export_filename = NULL,
1191              *import_filename = NULL,
1192              *import_filename_if_exists = NULL;
1193         uint32_t lastimportid;
1194         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
1195         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
1196         struct option options[] = {
1197                 OPT_INTEGER(0, "progress", &progress,
1198                             N_("show progress after <n> objects")),
1199                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1200                              N_("select handling of signed tags"),
1201                              parse_opt_signed_tag_mode),
1202                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1203                              N_("select handling of tags that tag filtered objects"),
1204                              parse_opt_tag_of_filtered_mode),
1205                 OPT_CALLBACK(0, "reencode", &reencode_mode, N_("mode"),
1206                              N_("select handling of commit messages in an alternate encoding"),
1207                              parse_opt_reencode_mode),
1208                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1209                              N_("Dump marks to this file")),
1210                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1211                              N_("Import marks from this file")),
1212                 OPT_STRING(0, "import-marks-if-exists",
1213                              &import_filename_if_exists,
1214                              N_("file"),
1215                              N_("Import marks from this file if it exists")),
1216                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1217                          N_("Fake a tagger when tags lack one")),
1218                 OPT_BOOL(0, "full-tree", &full_tree,
1219                          N_("Output full tree for each commit")),
1220                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1221                              N_("Use the done feature to terminate the stream")),
1222                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1223                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1224                              N_("Apply refspec to exported refs")),
1225                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1226                 OPT_CALLBACK_F(0, "anonymize-map", &anonymized_seeds, N_("from:to"),
1227                                N_("convert <from> to <to> in anonymized output"),
1228                                PARSE_OPT_NONEG, parse_opt_anonymize_map),
1229                 OPT_BOOL(0, "reference-excluded-parents",
1230                          &reference_excluded_commits, N_("Reference parents which are not in fast-export stream by object id")),
1231                 OPT_BOOL(0, "show-original-ids", &show_original_ids,
1232                             N_("Show original object ids of blobs/commits")),
1233                 OPT_BOOL(0, "mark-tags", &mark_tags,
1234                             N_("Label tags with mark ids")),
1235
1236                 OPT_END()
1237         };
1238
1239         if (argc == 1)
1240                 usage_with_options (fast_export_usage, options);
1241
1242         /* we handle encodings */
1243         git_config(git_default_config, NULL);
1244
1245         repo_init_revisions(the_repository, &revs, prefix);
1246         init_revision_sources(&revision_sources);
1247         revs.topo_order = 1;
1248         revs.sources = &revision_sources;
1249         revs.rewrite_parents = 1;
1250         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1251                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1252         argc = setup_revisions(argc, argv, &revs, NULL);
1253         if (argc > 1)
1254                 usage_with_options (fast_export_usage, options);
1255
1256         if (anonymized_seeds.cmpfn && !anonymize)
1257                 die(_("--anonymize-map without --anonymize does not make sense"));
1258
1259         if (refspecs_list.nr) {
1260                 int i;
1261
1262                 for (i = 0; i < refspecs_list.nr; i++)
1263                         refspec_append(&refspecs, refspecs_list.items[i].string);
1264
1265                 string_list_clear(&refspecs_list, 1);
1266         }
1267
1268         if (use_done_feature)
1269                 printf("feature done\n");
1270
1271         if (import_filename && import_filename_if_exists)
1272                 die(_("Cannot pass both --import-marks and --import-marks-if-exists"));
1273         if (import_filename)
1274                 import_marks(import_filename, 0);
1275         else if (import_filename_if_exists)
1276                 import_marks(import_filename_if_exists, 1);
1277         lastimportid = last_idnum;
1278
1279         if (import_filename && revs.prune_data.nr)
1280                 full_tree = 1;
1281
1282         get_tags_and_duplicates(&revs.cmdline);
1283
1284         if (prepare_revision_walk(&revs))
1285                 die("revision walk setup failed");
1286         revs.diffopt.format_callback = show_filemodify;
1287         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1288         revs.diffopt.flags.recursive = 1;
1289         while ((commit = get_revision(&revs))) {
1290                 if (has_unshown_parent(commit)) {
1291                         add_object_array(&commit->object, NULL, &commits);
1292                 }
1293                 else {
1294                         handle_commit(commit, &revs, &paths_of_changed_objects);
1295                         handle_tail(&commits, &revs, &paths_of_changed_objects);
1296                 }
1297         }
1298
1299         handle_tags_and_duplicates(&extra_refs);
1300         handle_tags_and_duplicates(&tag_refs);
1301         handle_deletes();
1302
1303         if (export_filename && lastimportid != last_idnum)
1304                 export_marks(export_filename);
1305
1306         if (use_done_feature)
1307                 printf("done\n");
1308
1309         refspec_clear(&refspecs);
1310
1311         return 0;
1312 }