Merge branch 'jn/doc-dashdash'
[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 "commit.h"
9 #include "object.h"
10 #include "tag.h"
11 #include "diff.h"
12 #include "diffcore.h"
13 #include "log-tree.h"
14 #include "revision.h"
15 #include "decorate.h"
16 #include "string-list.h"
17 #include "utf8.h"
18 #include "parse-options.h"
19
20 static const char *fast_export_usage[] = {
21         "git fast-export [rev-list-opts]",
22         NULL
23 };
24
25 static int progress;
26 static enum { ABORT, VERBATIM, WARN, STRIP } signed_tag_mode = ABORT;
27 static enum { ERROR, DROP, REWRITE } tag_of_filtered_mode = ABORT;
28 static int fake_missing_tagger;
29 static int no_data;
30 static int full_tree;
31
32 static int parse_opt_signed_tag_mode(const struct option *opt,
33                                      const char *arg, int unset)
34 {
35         if (unset || !strcmp(arg, "abort"))
36                 signed_tag_mode = ABORT;
37         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
38                 signed_tag_mode = VERBATIM;
39         else if (!strcmp(arg, "warn"))
40                 signed_tag_mode = WARN;
41         else if (!strcmp(arg, "strip"))
42                 signed_tag_mode = STRIP;
43         else
44                 return error("Unknown signed-tag mode: %s", arg);
45         return 0;
46 }
47
48 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
49                                           const char *arg, int unset)
50 {
51         if (unset || !strcmp(arg, "abort"))
52                 tag_of_filtered_mode = ABORT;
53         else if (!strcmp(arg, "drop"))
54                 tag_of_filtered_mode = DROP;
55         else if (!strcmp(arg, "rewrite"))
56                 tag_of_filtered_mode = REWRITE;
57         else
58                 return error("Unknown tag-of-filtered mode: %s", arg);
59         return 0;
60 }
61
62 static struct decoration idnums;
63 static uint32_t last_idnum;
64
65 static int has_unshown_parent(struct commit *commit)
66 {
67         struct commit_list *parent;
68
69         for (parent = commit->parents; parent; parent = parent->next)
70                 if (!(parent->item->object.flags & SHOWN) &&
71                     !(parent->item->object.flags & UNINTERESTING))
72                         return 1;
73         return 0;
74 }
75
76 /* Since intptr_t is C99, we do not use it here */
77 static inline uint32_t *mark_to_ptr(uint32_t mark)
78 {
79         return ((uint32_t *)NULL) + mark;
80 }
81
82 static inline uint32_t ptr_to_mark(void * mark)
83 {
84         return (uint32_t *)mark - (uint32_t *)NULL;
85 }
86
87 static inline void mark_object(struct object *object, uint32_t mark)
88 {
89         add_decoration(&idnums, object, mark_to_ptr(mark));
90 }
91
92 static inline void mark_next_object(struct object *object)
93 {
94         mark_object(object, ++last_idnum);
95 }
96
97 static int get_object_mark(struct object *object)
98 {
99         void *decoration = lookup_decoration(&idnums, object);
100         if (!decoration)
101                 return 0;
102         return ptr_to_mark(decoration);
103 }
104
105 static void show_progress(void)
106 {
107         static int counter = 0;
108         if (!progress)
109                 return;
110         if ((++counter % progress) == 0)
111                 printf("progress %d objects\n", counter);
112 }
113
114 static void handle_object(const unsigned char *sha1)
115 {
116         unsigned long size;
117         enum object_type type;
118         char *buf;
119         struct object *object;
120
121         if (no_data)
122                 return;
123
124         if (is_null_sha1(sha1))
125                 return;
126
127         object = parse_object(sha1);
128         if (!object)
129                 die ("Could not read blob %s", sha1_to_hex(sha1));
130
131         if (object->flags & SHOWN)
132                 return;
133
134         buf = read_sha1_file(sha1, &type, &size);
135         if (!buf)
136                 die ("Could not read blob %s", sha1_to_hex(sha1));
137
138         mark_next_object(object);
139
140         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
141         if (size && fwrite(buf, size, 1, stdout) != 1)
142                 die_errno ("Could not write blob '%s'", sha1_to_hex(sha1));
143         printf("\n");
144
145         show_progress();
146
147         object->flags |= SHOWN;
148         free(buf);
149 }
150
151 static int depth_first(const void *a_, const void *b_)
152 {
153         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
154         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
155         const char *name_a, *name_b;
156         int len_a, len_b, len;
157         int cmp;
158
159         name_a = a->one ? a->one->path : a->two->path;
160         name_b = b->one ? b->one->path : b->two->path;
161
162         len_a = strlen(name_a);
163         len_b = strlen(name_b);
164         len = (len_a < len_b) ? len_a : len_b;
165
166         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
167         cmp = memcmp(name_a, name_b, len);
168         if (cmp)
169                 return cmp;
170         cmp = len_b - len_a;
171         if (cmp)
172                 return cmp;
173         /*
174          * Move 'R'ename entries last so that all references of the file
175          * appear in the output before it is renamed (e.g., when a file
176          * was copied and renamed in the same commit).
177          */
178         return (a->status == 'R') - (b->status == 'R');
179 }
180
181 static void show_filemodify(struct diff_queue_struct *q,
182                             struct diff_options *options, void *data)
183 {
184         int i;
185
186         /*
187          * Handle files below a directory first, in case they are all deleted
188          * and the directory changes to a file or symlink.
189          */
190         qsort(q->queue, q->nr, sizeof(q->queue[0]), depth_first);
191
192         for (i = 0; i < q->nr; i++) {
193                 struct diff_filespec *ospec = q->queue[i]->one;
194                 struct diff_filespec *spec = q->queue[i]->two;
195
196                 switch (q->queue[i]->status) {
197                 case DIFF_STATUS_DELETED:
198                         printf("D %s\n", spec->path);
199                         break;
200
201                 case DIFF_STATUS_COPIED:
202                 case DIFF_STATUS_RENAMED:
203                         printf("%c \"%s\" \"%s\"\n", q->queue[i]->status,
204                                ospec->path, spec->path);
205
206                         if (!hashcmp(ospec->sha1, spec->sha1) &&
207                             ospec->mode == spec->mode)
208                                 break;
209                         /* fallthrough */
210
211                 case DIFF_STATUS_TYPE_CHANGED:
212                 case DIFF_STATUS_MODIFIED:
213                 case DIFF_STATUS_ADDED:
214                         /*
215                          * Links refer to objects in another repositories;
216                          * output the SHA-1 verbatim.
217                          */
218                         if (no_data || S_ISGITLINK(spec->mode))
219                                 printf("M %06o %s %s\n", spec->mode,
220                                        sha1_to_hex(spec->sha1), spec->path);
221                         else {
222                                 struct object *object = lookup_object(spec->sha1);
223                                 printf("M %06o :%d %s\n", spec->mode,
224                                        get_object_mark(object), spec->path);
225                         }
226                         break;
227
228                 default:
229                         die("Unexpected comparison status '%c' for %s, %s",
230                                 q->queue[i]->status,
231                                 ospec->path ? ospec->path : "none",
232                                 spec->path ? spec->path : "none");
233                 }
234         }
235 }
236
237 static const char *find_encoding(const char *begin, const char *end)
238 {
239         const char *needle = "\nencoding ";
240         char *bol, *eol;
241
242         bol = memmem(begin, end ? end - begin : strlen(begin),
243                      needle, strlen(needle));
244         if (!bol)
245                 return git_commit_encoding;
246         bol += strlen(needle);
247         eol = strchrnul(bol, '\n');
248         *eol = '\0';
249         return bol;
250 }
251
252 static void handle_commit(struct commit *commit, struct rev_info *rev)
253 {
254         int saved_output_format = rev->diffopt.output_format;
255         const char *author, *author_end, *committer, *committer_end;
256         const char *encoding, *message;
257         char *reencoded = NULL;
258         struct commit_list *p;
259         int i;
260
261         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
262
263         parse_commit(commit);
264         author = strstr(commit->buffer, "\nauthor ");
265         if (!author)
266                 die ("Could not find author in commit %s",
267                      sha1_to_hex(commit->object.sha1));
268         author++;
269         author_end = strchrnul(author, '\n');
270         committer = strstr(author_end, "\ncommitter ");
271         if (!committer)
272                 die ("Could not find committer in commit %s",
273                      sha1_to_hex(commit->object.sha1));
274         committer++;
275         committer_end = strchrnul(committer, '\n');
276         message = strstr(committer_end, "\n\n");
277         encoding = find_encoding(committer_end, message);
278         if (message)
279                 message += 2;
280
281         if (commit->parents &&
282             get_object_mark(&commit->parents->item->object) != 0 &&
283             !full_tree) {
284                 parse_commit(commit->parents->item);
285                 diff_tree_sha1(commit->parents->item->tree->object.sha1,
286                                commit->tree->object.sha1, "", &rev->diffopt);
287         }
288         else
289                 diff_root_tree_sha1(commit->tree->object.sha1,
290                                     "", &rev->diffopt);
291
292         /* Export the referenced blobs, and remember the marks. */
293         for (i = 0; i < diff_queued_diff.nr; i++)
294                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
295                         handle_object(diff_queued_diff.queue[i]->two->sha1);
296
297         mark_next_object(&commit->object);
298         if (!is_encoding_utf8(encoding))
299                 reencoded = reencode_string(message, "UTF-8", encoding);
300         if (!commit->parents)
301                 printf("reset %s\n", (const char*)commit->util);
302         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
303                (const char *)commit->util, last_idnum,
304                (int)(author_end - author), author,
305                (int)(committer_end - committer), committer,
306                (unsigned)(reencoded
307                           ? strlen(reencoded) : message
308                           ? strlen(message) : 0),
309                reencoded ? reencoded : message ? message : "");
310         free(reencoded);
311
312         for (i = 0, p = commit->parents; p; p = p->next) {
313                 int mark = get_object_mark(&p->item->object);
314                 if (!mark)
315                         continue;
316                 if (i == 0)
317                         printf("from :%d\n", mark);
318                 else
319                         printf("merge :%d\n", mark);
320                 i++;
321         }
322
323         if (full_tree)
324                 printf("deleteall\n");
325         log_tree_diff_flush(rev);
326         rev->diffopt.output_format = saved_output_format;
327
328         printf("\n");
329
330         show_progress();
331 }
332
333 static void handle_tail(struct object_array *commits, struct rev_info *revs)
334 {
335         struct commit *commit;
336         while (commits->nr) {
337                 commit = (struct commit *)commits->objects[commits->nr - 1].item;
338                 if (has_unshown_parent(commit))
339                         return;
340                 handle_commit(commit, revs);
341                 commits->nr--;
342         }
343 }
344
345 static void handle_tag(const char *name, struct tag *tag)
346 {
347         unsigned long size;
348         enum object_type type;
349         char *buf;
350         const char *tagger, *tagger_end, *message;
351         size_t message_size = 0;
352         struct object *tagged;
353         int tagged_mark;
354         struct commit *p;
355
356         /* Trees have no identifer in fast-export output, thus we have no way
357          * to output tags of trees, tags of tags of trees, etc.  Simply omit
358          * such tags.
359          */
360         tagged = tag->tagged;
361         while (tagged->type == OBJ_TAG) {
362                 tagged = ((struct tag *)tagged)->tagged;
363         }
364         if (tagged->type == OBJ_TREE) {
365                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
366                         sha1_to_hex(tag->object.sha1));
367                 return;
368         }
369
370         buf = read_sha1_file(tag->object.sha1, &type, &size);
371         if (!buf)
372                 die ("Could not read tag %s", sha1_to_hex(tag->object.sha1));
373         message = memmem(buf, size, "\n\n", 2);
374         if (message) {
375                 message += 2;
376                 message_size = strlen(message);
377         }
378         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
379         if (!tagger) {
380                 if (fake_missing_tagger)
381                         tagger = "tagger Unspecified Tagger "
382                                 "<unspecified-tagger> 0 +0000";
383                 else
384                         tagger = "";
385                 tagger_end = tagger + strlen(tagger);
386         } else {
387                 tagger++;
388                 tagger_end = strchrnul(tagger, '\n');
389         }
390
391         /* handle signed tags */
392         if (message) {
393                 const char *signature = strstr(message,
394                                                "\n-----BEGIN PGP SIGNATURE-----\n");
395                 if (signature)
396                         switch(signed_tag_mode) {
397                         case ABORT:
398                                 die ("Encountered signed tag %s; use "
399                                      "--signed-tag=<mode> to handle it.",
400                                      sha1_to_hex(tag->object.sha1));
401                         case WARN:
402                                 warning ("Exporting signed tag %s",
403                                          sha1_to_hex(tag->object.sha1));
404                                 /* fallthru */
405                         case VERBATIM:
406                                 break;
407                         case STRIP:
408                                 message_size = signature + 1 - message;
409                                 break;
410                         }
411         }
412
413         /* handle tag->tagged having been filtered out due to paths specified */
414         tagged = tag->tagged;
415         tagged_mark = get_object_mark(tagged);
416         if (!tagged_mark) {
417                 switch(tag_of_filtered_mode) {
418                 case ABORT:
419                         die ("Tag %s tags unexported object; use "
420                              "--tag-of-filtered-object=<mode> to handle it.",
421                              sha1_to_hex(tag->object.sha1));
422                 case DROP:
423                         /* Ignore this tag altogether */
424                         return;
425                 case REWRITE:
426                         if (tagged->type != OBJ_COMMIT) {
427                                 die ("Tag %s tags unexported %s!",
428                                      sha1_to_hex(tag->object.sha1),
429                                      typename(tagged->type));
430                         }
431                         p = (struct commit *)tagged;
432                         for (;;) {
433                                 if (p->parents && p->parents->next)
434                                         break;
435                                 if (p->object.flags & UNINTERESTING)
436                                         break;
437                                 if (!(p->object.flags & TREESAME))
438                                         break;
439                                 if (!p->parents)
440                                         die ("Can't find replacement commit for tag %s\n",
441                                              sha1_to_hex(tag->object.sha1));
442                                 p = p->parents->item;
443                         }
444                         tagged_mark = get_object_mark(&p->object);
445                 }
446         }
447
448         if (!prefixcmp(name, "refs/tags/"))
449                 name += 10;
450         printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
451                name, tagged_mark,
452                (int)(tagger_end - tagger), tagger,
453                tagger == tagger_end ? "" : "\n",
454                (int)message_size, (int)message_size, message ? message : "");
455 }
456
457 static void get_tags_and_duplicates(struct object_array *pending,
458                                     struct string_list *extra_refs)
459 {
460         struct tag *tag;
461         int i;
462
463         for (i = 0; i < pending->nr; i++) {
464                 struct object_array_entry *e = pending->objects + i;
465                 unsigned char sha1[20];
466                 struct commit *commit = commit;
467                 char *full_name;
468
469                 if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
470                         continue;
471
472                 switch (e->item->type) {
473                 case OBJ_COMMIT:
474                         commit = (struct commit *)e->item;
475                         break;
476                 case OBJ_TAG:
477                         tag = (struct tag *)e->item;
478
479                         /* handle nested tags */
480                         while (tag && tag->object.type == OBJ_TAG) {
481                                 parse_object(tag->object.sha1);
482                                 string_list_append(extra_refs, full_name)->util = tag;
483                                 tag = (struct tag *)tag->tagged;
484                         }
485                         if (!tag)
486                                 die ("Tag %s points nowhere?", e->name);
487                         switch(tag->object.type) {
488                         case OBJ_COMMIT:
489                                 commit = (struct commit *)tag;
490                                 break;
491                         case OBJ_BLOB:
492                                 handle_object(tag->object.sha1);
493                                 continue;
494                         default: /* OBJ_TAG (nested tags) is already handled */
495                                 warning("Tag points to object of unexpected type %s, skipping.",
496                                         typename(tag->object.type));
497                                 continue;
498                         }
499                         break;
500                 default:
501                         warning("%s: Unexpected object of type %s, skipping.",
502                                 e->name,
503                                 typename(e->item->type));
504                         continue;
505                 }
506                 if (commit->util)
507                         /* more than one name for the same object */
508                         string_list_append(extra_refs, full_name)->util = commit;
509                 else
510                         commit->util = full_name;
511         }
512 }
513
514 static void handle_tags_and_duplicates(struct string_list *extra_refs)
515 {
516         struct commit *commit;
517         int i;
518
519         for (i = extra_refs->nr - 1; i >= 0; i--) {
520                 const char *name = extra_refs->items[i].string;
521                 struct object *object = extra_refs->items[i].util;
522                 switch (object->type) {
523                 case OBJ_TAG:
524                         handle_tag(name, (struct tag *)object);
525                         break;
526                 case OBJ_COMMIT:
527                         /* create refs pointing to already seen commits */
528                         commit = (struct commit *)object;
529                         printf("reset %s\nfrom :%d\n\n", name,
530                                get_object_mark(&commit->object));
531                         show_progress();
532                         break;
533                 }
534         }
535 }
536
537 static void export_marks(char *file)
538 {
539         unsigned int i;
540         uint32_t mark;
541         struct object_decoration *deco = idnums.hash;
542         FILE *f;
543         int e = 0;
544
545         f = fopen(file, "w");
546         if (!f)
547                 die_errno("Unable to open marks file %s for writing.", file);
548
549         for (i = 0; i < idnums.size; i++) {
550                 if (deco->base && deco->base->type == 1) {
551                         mark = ptr_to_mark(deco->decoration);
552                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
553                                 sha1_to_hex(deco->base->sha1)) < 0) {
554                             e = 1;
555                             break;
556                         }
557                 }
558                 deco++;
559         }
560
561         e |= ferror(f);
562         e |= fclose(f);
563         if (e)
564                 error("Unable to write marks file %s.", file);
565 }
566
567 static void import_marks(char *input_file)
568 {
569         char line[512];
570         FILE *f = fopen(input_file, "r");
571         if (!f)
572                 die_errno("cannot read '%s'", input_file);
573
574         while (fgets(line, sizeof(line), f)) {
575                 uint32_t mark;
576                 char *line_end, *mark_end;
577                 unsigned char sha1[20];
578                 struct object *object;
579
580                 line_end = strchr(line, '\n');
581                 if (line[0] != ':' || !line_end)
582                         die("corrupt mark line: %s", line);
583                 *line_end = '\0';
584
585                 mark = strtoumax(line + 1, &mark_end, 10);
586                 if (!mark || mark_end == line + 1
587                         || *mark_end != ' ' || get_sha1(mark_end + 1, sha1))
588                         die("corrupt mark line: %s", line);
589
590                 object = parse_object(sha1);
591                 if (!object)
592                         die ("Could not read blob %s", sha1_to_hex(sha1));
593
594                 if (object->flags & SHOWN)
595                         error("Object %s already has a mark", sha1);
596
597                 mark_object(object, mark);
598                 if (last_idnum < mark)
599                         last_idnum = mark;
600
601                 object->flags |= SHOWN;
602         }
603         fclose(f);
604 }
605
606 int cmd_fast_export(int argc, const char **argv, const char *prefix)
607 {
608         struct rev_info revs;
609         struct object_array commits = OBJECT_ARRAY_INIT;
610         struct string_list extra_refs = STRING_LIST_INIT_NODUP;
611         struct commit *commit;
612         char *export_filename = NULL, *import_filename = NULL;
613         struct option options[] = {
614                 OPT_INTEGER(0, "progress", &progress,
615                             "show progress after <n> objects"),
616                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, "mode",
617                              "select handling of signed tags",
618                              parse_opt_signed_tag_mode),
619                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, "mode",
620                              "select handling of tags that tag filtered objects",
621                              parse_opt_tag_of_filtered_mode),
622                 OPT_STRING(0, "export-marks", &export_filename, "file",
623                              "Dump marks to this file"),
624                 OPT_STRING(0, "import-marks", &import_filename, "file",
625                              "Import marks from this file"),
626                 OPT_BOOLEAN(0, "fake-missing-tagger", &fake_missing_tagger,
627                              "Fake a tagger when tags lack one"),
628                 OPT_BOOLEAN(0, "full-tree", &full_tree,
629                              "Output full tree for each commit"),
630                 { OPTION_NEGBIT, 0, "data", &no_data, NULL,
631                         "Skip output of blob data",
632                         PARSE_OPT_NOARG | PARSE_OPT_NEGHELP, NULL, 1 },
633                 OPT_END()
634         };
635
636         if (argc == 1)
637                 usage_with_options (fast_export_usage, options);
638
639         /* we handle encodings */
640         git_config(git_default_config, NULL);
641
642         init_revisions(&revs, prefix);
643         revs.topo_order = 1;
644         revs.show_source = 1;
645         revs.rewrite_parents = 1;
646         argc = setup_revisions(argc, argv, &revs, NULL);
647         argc = parse_options(argc, argv, prefix, options, fast_export_usage, 0);
648         if (argc > 1)
649                 usage_with_options (fast_export_usage, options);
650
651         if (import_filename)
652                 import_marks(import_filename);
653
654         if (import_filename && revs.prune_data.nr)
655                 full_tree = 1;
656
657         get_tags_and_duplicates(&revs.pending, &extra_refs);
658
659         if (prepare_revision_walk(&revs))
660                 die("revision walk setup failed");
661         revs.diffopt.format_callback = show_filemodify;
662         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
663         while ((commit = get_revision(&revs))) {
664                 if (has_unshown_parent(commit)) {
665                         add_object_array(&commit->object, NULL, &commits);
666                 }
667                 else {
668                         handle_commit(commit, &revs);
669                         handle_tail(&commits, &revs);
670                 }
671         }
672
673         handle_tags_and_duplicates(&extra_refs);
674
675         if (export_filename)
676                 export_marks(export_filename);
677
678         return 0;
679 }