Merge branch 'ld/p4-unshelve-fix'
[git] / 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         unsigned char out[GIT_MAX_RAWSZ];
409         char *hex = xmallocz(GIT_MAX_HEXSZ);
410
411         hashclr(out);
412         put_be32(out + hashsz - 4, counter++);
413         return hash_to_hex_algop_r(hex, out, the_hash_algo);
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 ^master master).  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 }