Merge branch 'jk/common-make-variables-export-safety'
[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 #include "quote.h"
20
21 static const char *fast_export_usage[] = {
22         N_("git fast-export [rev-list-opts]"),
23         NULL
24 };
25
26 static int progress;
27 static enum { ABORT, VERBATIM, WARN, STRIP } signed_tag_mode = ABORT;
28 static enum { ERROR, DROP, REWRITE } tag_of_filtered_mode = ERROR;
29 static int fake_missing_tagger;
30 static int use_done_feature;
31 static int no_data;
32 static int full_tree;
33
34 static int parse_opt_signed_tag_mode(const struct option *opt,
35                                      const char *arg, int unset)
36 {
37         if (unset || !strcmp(arg, "abort"))
38                 signed_tag_mode = ABORT;
39         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
40                 signed_tag_mode = VERBATIM;
41         else if (!strcmp(arg, "warn"))
42                 signed_tag_mode = WARN;
43         else if (!strcmp(arg, "strip"))
44                 signed_tag_mode = STRIP;
45         else
46                 return error("Unknown signed-tag mode: %s", arg);
47         return 0;
48 }
49
50 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
51                                           const char *arg, int unset)
52 {
53         if (unset || !strcmp(arg, "abort"))
54                 tag_of_filtered_mode = ERROR;
55         else if (!strcmp(arg, "drop"))
56                 tag_of_filtered_mode = DROP;
57         else if (!strcmp(arg, "rewrite"))
58                 tag_of_filtered_mode = REWRITE;
59         else
60                 return error("Unknown tag-of-filtered mode: %s", arg);
61         return 0;
62 }
63
64 static struct decoration idnums;
65 static uint32_t last_idnum;
66
67 static int has_unshown_parent(struct commit *commit)
68 {
69         struct commit_list *parent;
70
71         for (parent = commit->parents; parent; parent = parent->next)
72                 if (!(parent->item->object.flags & SHOWN) &&
73                     !(parent->item->object.flags & UNINTERESTING))
74                         return 1;
75         return 0;
76 }
77
78 /* Since intptr_t is C99, we do not use it here */
79 static inline uint32_t *mark_to_ptr(uint32_t mark)
80 {
81         return ((uint32_t *)NULL) + mark;
82 }
83
84 static inline uint32_t ptr_to_mark(void * mark)
85 {
86         return (uint32_t *)mark - (uint32_t *)NULL;
87 }
88
89 static inline void mark_object(struct object *object, uint32_t mark)
90 {
91         add_decoration(&idnums, object, mark_to_ptr(mark));
92 }
93
94 static inline void mark_next_object(struct object *object)
95 {
96         mark_object(object, ++last_idnum);
97 }
98
99 static int get_object_mark(struct object *object)
100 {
101         void *decoration = lookup_decoration(&idnums, object);
102         if (!decoration)
103                 return 0;
104         return ptr_to_mark(decoration);
105 }
106
107 static void show_progress(void)
108 {
109         static int counter = 0;
110         if (!progress)
111                 return;
112         if ((++counter % progress) == 0)
113                 printf("progress %d objects\n", counter);
114 }
115
116 static void export_blob(const unsigned char *sha1)
117 {
118         unsigned long size;
119         enum object_type type;
120         char *buf;
121         struct object *object;
122         int eaten;
123
124         if (no_data)
125                 return;
126
127         if (is_null_sha1(sha1))
128                 return;
129
130         object = lookup_object(sha1);
131         if (object && 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         if (check_sha1_signature(sha1, buf, size, typename(type)) < 0)
138                 die("sha1 mismatch in blob %s", sha1_to_hex(sha1));
139         object = parse_object_buffer(sha1, type, size, buf, &eaten);
140         if (!object)
141                 die("Could not read blob %s", sha1_to_hex(sha1));
142
143         mark_next_object(object);
144
145         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
146         if (size && fwrite(buf, size, 1, stdout) != 1)
147                 die_errno ("Could not write blob '%s'", sha1_to_hex(sha1));
148         printf("\n");
149
150         show_progress();
151
152         object->flags |= SHOWN;
153         if (!eaten)
154                 free(buf);
155 }
156
157 static int depth_first(const void *a_, const void *b_)
158 {
159         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
160         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
161         const char *name_a, *name_b;
162         int len_a, len_b, len;
163         int cmp;
164
165         name_a = a->one ? a->one->path : a->two->path;
166         name_b = b->one ? b->one->path : b->two->path;
167
168         len_a = strlen(name_a);
169         len_b = strlen(name_b);
170         len = (len_a < len_b) ? len_a : len_b;
171
172         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
173         cmp = memcmp(name_a, name_b, len);
174         if (cmp)
175                 return cmp;
176         cmp = len_b - len_a;
177         if (cmp)
178                 return cmp;
179         /*
180          * Move 'R'ename entries last so that all references of the file
181          * appear in the output before it is renamed (e.g., when a file
182          * was copied and renamed in the same commit).
183          */
184         return (a->status == 'R') - (b->status == 'R');
185 }
186
187 static void print_path(const char *path)
188 {
189         int need_quote = quote_c_style(path, NULL, NULL, 0);
190         if (need_quote)
191                 quote_c_style(path, NULL, stdout, 0);
192         else if (strchr(path, ' '))
193                 printf("\"%s\"", path);
194         else
195                 printf("%s", path);
196 }
197
198 static void show_filemodify(struct diff_queue_struct *q,
199                             struct diff_options *options, void *data)
200 {
201         int i;
202
203         /*
204          * Handle files below a directory first, in case they are all deleted
205          * and the directory changes to a file or symlink.
206          */
207         qsort(q->queue, q->nr, sizeof(q->queue[0]), depth_first);
208
209         for (i = 0; i < q->nr; i++) {
210                 struct diff_filespec *ospec = q->queue[i]->one;
211                 struct diff_filespec *spec = q->queue[i]->two;
212
213                 switch (q->queue[i]->status) {
214                 case DIFF_STATUS_DELETED:
215                         printf("D ");
216                         print_path(spec->path);
217                         putchar('\n');
218                         break;
219
220                 case DIFF_STATUS_COPIED:
221                 case DIFF_STATUS_RENAMED:
222                         printf("%c ", q->queue[i]->status);
223                         print_path(ospec->path);
224                         putchar(' ');
225                         print_path(spec->path);
226                         putchar('\n');
227
228                         if (!hashcmp(ospec->sha1, spec->sha1) &&
229                             ospec->mode == spec->mode)
230                                 break;
231                         /* fallthrough */
232
233                 case DIFF_STATUS_TYPE_CHANGED:
234                 case DIFF_STATUS_MODIFIED:
235                 case DIFF_STATUS_ADDED:
236                         /*
237                          * Links refer to objects in another repositories;
238                          * output the SHA-1 verbatim.
239                          */
240                         if (no_data || S_ISGITLINK(spec->mode))
241                                 printf("M %06o %s ", spec->mode,
242                                        sha1_to_hex(spec->sha1));
243                         else {
244                                 struct object *object = lookup_object(spec->sha1);
245                                 printf("M %06o :%d ", spec->mode,
246                                        get_object_mark(object));
247                         }
248                         print_path(spec->path);
249                         putchar('\n');
250                         break;
251
252                 default:
253                         die("Unexpected comparison status '%c' for %s, %s",
254                                 q->queue[i]->status,
255                                 ospec->path ? ospec->path : "none",
256                                 spec->path ? spec->path : "none");
257                 }
258         }
259 }
260
261 static const char *find_encoding(const char *begin, const char *end)
262 {
263         const char *needle = "\nencoding ";
264         char *bol, *eol;
265
266         bol = memmem(begin, end ? end - begin : strlen(begin),
267                      needle, strlen(needle));
268         if (!bol)
269                 return git_commit_encoding;
270         bol += strlen(needle);
271         eol = strchrnul(bol, '\n');
272         *eol = '\0';
273         return bol;
274 }
275
276 static void handle_commit(struct commit *commit, struct rev_info *rev)
277 {
278         int saved_output_format = rev->diffopt.output_format;
279         const char *author, *author_end, *committer, *committer_end;
280         const char *encoding, *message;
281         char *reencoded = NULL;
282         struct commit_list *p;
283         int i;
284
285         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
286
287         parse_commit(commit);
288         author = strstr(commit->buffer, "\nauthor ");
289         if (!author)
290                 die ("Could not find author in commit %s",
291                      sha1_to_hex(commit->object.sha1));
292         author++;
293         author_end = strchrnul(author, '\n');
294         committer = strstr(author_end, "\ncommitter ");
295         if (!committer)
296                 die ("Could not find committer in commit %s",
297                      sha1_to_hex(commit->object.sha1));
298         committer++;
299         committer_end = strchrnul(committer, '\n');
300         message = strstr(committer_end, "\n\n");
301         encoding = find_encoding(committer_end, message);
302         if (message)
303                 message += 2;
304
305         if (commit->parents &&
306             get_object_mark(&commit->parents->item->object) != 0 &&
307             !full_tree) {
308                 parse_commit(commit->parents->item);
309                 diff_tree_sha1(commit->parents->item->tree->object.sha1,
310                                commit->tree->object.sha1, "", &rev->diffopt);
311         }
312         else
313                 diff_root_tree_sha1(commit->tree->object.sha1,
314                                     "", &rev->diffopt);
315
316         /* Export the referenced blobs, and remember the marks. */
317         for (i = 0; i < diff_queued_diff.nr; i++)
318                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
319                         export_blob(diff_queued_diff.queue[i]->two->sha1);
320
321         mark_next_object(&commit->object);
322         if (!is_encoding_utf8(encoding))
323                 reencoded = reencode_string(message, "UTF-8", encoding);
324         if (!commit->parents)
325                 printf("reset %s\n", (const char*)commit->util);
326         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
327                (const char *)commit->util, last_idnum,
328                (int)(author_end - author), author,
329                (int)(committer_end - committer), committer,
330                (unsigned)(reencoded
331                           ? strlen(reencoded) : message
332                           ? strlen(message) : 0),
333                reencoded ? reencoded : message ? message : "");
334         free(reencoded);
335
336         for (i = 0, p = commit->parents; p; p = p->next) {
337                 int mark = get_object_mark(&p->item->object);
338                 if (!mark)
339                         continue;
340                 if (i == 0)
341                         printf("from :%d\n", mark);
342                 else
343                         printf("merge :%d\n", mark);
344                 i++;
345         }
346
347         if (full_tree)
348                 printf("deleteall\n");
349         log_tree_diff_flush(rev);
350         rev->diffopt.output_format = saved_output_format;
351
352         printf("\n");
353
354         show_progress();
355 }
356
357 static void handle_tail(struct object_array *commits, struct rev_info *revs)
358 {
359         struct commit *commit;
360         while (commits->nr) {
361                 commit = (struct commit *)commits->objects[commits->nr - 1].item;
362                 if (has_unshown_parent(commit))
363                         return;
364                 handle_commit(commit, revs);
365                 commits->nr--;
366         }
367 }
368
369 static void handle_tag(const char *name, struct tag *tag)
370 {
371         unsigned long size;
372         enum object_type type;
373         char *buf;
374         const char *tagger, *tagger_end, *message;
375         size_t message_size = 0;
376         struct object *tagged;
377         int tagged_mark;
378         struct commit *p;
379
380         /* Trees have no identifer in fast-export output, thus we have no way
381          * to output tags of trees, tags of tags of trees, etc.  Simply omit
382          * such tags.
383          */
384         tagged = tag->tagged;
385         while (tagged->type == OBJ_TAG) {
386                 tagged = ((struct tag *)tagged)->tagged;
387         }
388         if (tagged->type == OBJ_TREE) {
389                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
390                         sha1_to_hex(tag->object.sha1));
391                 return;
392         }
393
394         buf = read_sha1_file(tag->object.sha1, &type, &size);
395         if (!buf)
396                 die ("Could not read tag %s", sha1_to_hex(tag->object.sha1));
397         message = memmem(buf, size, "\n\n", 2);
398         if (message) {
399                 message += 2;
400                 message_size = strlen(message);
401         }
402         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
403         if (!tagger) {
404                 if (fake_missing_tagger)
405                         tagger = "tagger Unspecified Tagger "
406                                 "<unspecified-tagger> 0 +0000";
407                 else
408                         tagger = "";
409                 tagger_end = tagger + strlen(tagger);
410         } else {
411                 tagger++;
412                 tagger_end = strchrnul(tagger, '\n');
413         }
414
415         /* handle signed tags */
416         if (message) {
417                 const char *signature = strstr(message,
418                                                "\n-----BEGIN PGP SIGNATURE-----\n");
419                 if (signature)
420                         switch(signed_tag_mode) {
421                         case ABORT:
422                                 die ("Encountered signed tag %s; use "
423                                      "--signed-tag=<mode> to handle it.",
424                                      sha1_to_hex(tag->object.sha1));
425                         case WARN:
426                                 warning ("Exporting signed tag %s",
427                                          sha1_to_hex(tag->object.sha1));
428                                 /* fallthru */
429                         case VERBATIM:
430                                 break;
431                         case STRIP:
432                                 message_size = signature + 1 - message;
433                                 break;
434                         }
435         }
436
437         /* handle tag->tagged having been filtered out due to paths specified */
438         tagged = tag->tagged;
439         tagged_mark = get_object_mark(tagged);
440         if (!tagged_mark) {
441                 switch(tag_of_filtered_mode) {
442                 case ABORT:
443                         die ("Tag %s tags unexported object; use "
444                              "--tag-of-filtered-object=<mode> to handle it.",
445                              sha1_to_hex(tag->object.sha1));
446                 case DROP:
447                         /* Ignore this tag altogether */
448                         return;
449                 case REWRITE:
450                         if (tagged->type != OBJ_COMMIT) {
451                                 die ("Tag %s tags unexported %s!",
452                                      sha1_to_hex(tag->object.sha1),
453                                      typename(tagged->type));
454                         }
455                         p = (struct commit *)tagged;
456                         for (;;) {
457                                 if (p->parents && p->parents->next)
458                                         break;
459                                 if (p->object.flags & UNINTERESTING)
460                                         break;
461                                 if (!(p->object.flags & TREESAME))
462                                         break;
463                                 if (!p->parents)
464                                         die ("Can't find replacement commit for tag %s\n",
465                                              sha1_to_hex(tag->object.sha1));
466                                 p = p->parents->item;
467                         }
468                         tagged_mark = get_object_mark(&p->object);
469                 }
470         }
471
472         if (!prefixcmp(name, "refs/tags/"))
473                 name += 10;
474         printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
475                name, tagged_mark,
476                (int)(tagger_end - tagger), tagger,
477                tagger == tagger_end ? "" : "\n",
478                (int)message_size, (int)message_size, message ? message : "");
479 }
480
481 static void get_tags_and_duplicates(struct rev_cmdline_info *info,
482                                     struct string_list *extra_refs)
483 {
484         struct tag *tag;
485         int i;
486
487         for (i = 0; i < info->nr; i++) {
488                 struct rev_cmdline_entry *e = info->rev + i;
489                 unsigned char sha1[20];
490                 struct commit *commit;
491                 char *full_name;
492
493                 if (e->flags & UNINTERESTING)
494                         continue;
495
496                 if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
497                         continue;
498
499                 switch (e->item->type) {
500                 case OBJ_COMMIT:
501                         commit = (struct commit *)e->item;
502                         break;
503                 case OBJ_TAG:
504                         tag = (struct tag *)e->item;
505
506                         /* handle nested tags */
507                         while (tag && tag->object.type == OBJ_TAG) {
508                                 parse_object(tag->object.sha1);
509                                 string_list_append(extra_refs, full_name)->util = tag;
510                                 tag = (struct tag *)tag->tagged;
511                         }
512                         if (!tag)
513                                 die ("Tag %s points nowhere?", e->name);
514                         switch(tag->object.type) {
515                         case OBJ_COMMIT:
516                                 commit = (struct commit *)tag;
517                                 break;
518                         case OBJ_BLOB:
519                                 export_blob(tag->object.sha1);
520                                 continue;
521                         default: /* OBJ_TAG (nested tags) is already handled */
522                                 warning("Tag points to object of unexpected type %s, skipping.",
523                                         typename(tag->object.type));
524                                 continue;
525                         }
526                         break;
527                 default:
528                         warning("%s: Unexpected object of type %s, skipping.",
529                                 e->name,
530                                 typename(e->item->type));
531                         continue;
532                 }
533
534                 /*
535                  * This ref will not be updated through a commit, lets make
536                  * sure it gets properly updated eventually.
537                  */
538                 if (commit->util || commit->object.flags & SHOWN)
539                         string_list_append(extra_refs, full_name)->util = commit;
540                 if (!commit->util)
541                         commit->util = full_name;
542         }
543 }
544
545 static void handle_tags_and_duplicates(struct string_list *extra_refs)
546 {
547         struct commit *commit;
548         int i;
549
550         for (i = extra_refs->nr - 1; i >= 0; i--) {
551                 const char *name = extra_refs->items[i].string;
552                 struct object *object = extra_refs->items[i].util;
553                 switch (object->type) {
554                 case OBJ_TAG:
555                         handle_tag(name, (struct tag *)object);
556                         break;
557                 case OBJ_COMMIT:
558                         /* create refs pointing to already seen commits */
559                         commit = (struct commit *)object;
560                         printf("reset %s\nfrom :%d\n\n", name,
561                                get_object_mark(&commit->object));
562                         show_progress();
563                         break;
564                 }
565         }
566 }
567
568 static void export_marks(char *file)
569 {
570         unsigned int i;
571         uint32_t mark;
572         struct object_decoration *deco = idnums.hash;
573         FILE *f;
574         int e = 0;
575
576         f = fopen(file, "w");
577         if (!f)
578                 die_errno("Unable to open marks file %s for writing.", file);
579
580         for (i = 0; i < idnums.size; i++) {
581                 if (deco->base && deco->base->type == 1) {
582                         mark = ptr_to_mark(deco->decoration);
583                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
584                                 sha1_to_hex(deco->base->sha1)) < 0) {
585                             e = 1;
586                             break;
587                         }
588                 }
589                 deco++;
590         }
591
592         e |= ferror(f);
593         e |= fclose(f);
594         if (e)
595                 error("Unable to write marks file %s.", file);
596 }
597
598 static void import_marks(char *input_file)
599 {
600         char line[512];
601         FILE *f = fopen(input_file, "r");
602         if (!f)
603                 die_errno("cannot read '%s'", input_file);
604
605         while (fgets(line, sizeof(line), f)) {
606                 uint32_t mark;
607                 char *line_end, *mark_end;
608                 unsigned char sha1[20];
609                 struct object *object;
610
611                 line_end = strchr(line, '\n');
612                 if (line[0] != ':' || !line_end)
613                         die("corrupt mark line: %s", line);
614                 *line_end = '\0';
615
616                 mark = strtoumax(line + 1, &mark_end, 10);
617                 if (!mark || mark_end == line + 1
618                         || *mark_end != ' ' || get_sha1(mark_end + 1, sha1))
619                         die("corrupt mark line: %s", line);
620
621                 object = parse_object(sha1);
622                 if (!object)
623                         die ("Could not read blob %s", sha1_to_hex(sha1));
624
625                 if (object->flags & SHOWN)
626                         error("Object %s already has a mark", sha1_to_hex(sha1));
627
628                 if (object->type != OBJ_COMMIT)
629                         /* only commits */
630                         continue;
631
632                 mark_object(object, mark);
633                 if (last_idnum < mark)
634                         last_idnum = mark;
635
636                 object->flags |= SHOWN;
637         }
638         fclose(f);
639 }
640
641 int cmd_fast_export(int argc, const char **argv, const char *prefix)
642 {
643         struct rev_info revs;
644         struct object_array commits = OBJECT_ARRAY_INIT;
645         struct string_list extra_refs = STRING_LIST_INIT_NODUP;
646         struct commit *commit;
647         char *export_filename = NULL, *import_filename = NULL;
648         struct option options[] = {
649                 OPT_INTEGER(0, "progress", &progress,
650                             N_("show progress after <n> objects")),
651                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
652                              N_("select handling of signed tags"),
653                              parse_opt_signed_tag_mode),
654                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
655                              N_("select handling of tags that tag filtered objects"),
656                              parse_opt_tag_of_filtered_mode),
657                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
658                              N_("Dump marks to this file")),
659                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
660                              N_("Import marks from this file")),
661                 OPT_BOOLEAN(0, "fake-missing-tagger", &fake_missing_tagger,
662                              N_("Fake a tagger when tags lack one")),
663                 OPT_BOOLEAN(0, "full-tree", &full_tree,
664                              N_("Output full tree for each commit")),
665                 OPT_BOOLEAN(0, "use-done-feature", &use_done_feature,
666                              N_("Use the done feature to terminate the stream")),
667                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
668                 OPT_END()
669         };
670
671         if (argc == 1)
672                 usage_with_options (fast_export_usage, options);
673
674         /* we handle encodings */
675         git_config(git_default_config, NULL);
676
677         init_revisions(&revs, prefix);
678         revs.topo_order = 1;
679         revs.show_source = 1;
680         revs.rewrite_parents = 1;
681         argc = setup_revisions(argc, argv, &revs, NULL);
682         argc = parse_options(argc, argv, prefix, options, fast_export_usage, 0);
683         if (argc > 1)
684                 usage_with_options (fast_export_usage, options);
685
686         if (use_done_feature)
687                 printf("feature done\n");
688
689         if (import_filename)
690                 import_marks(import_filename);
691
692         if (import_filename && revs.prune_data.nr)
693                 full_tree = 1;
694
695         get_tags_and_duplicates(&revs.cmdline, &extra_refs);
696
697         if (prepare_revision_walk(&revs))
698                 die("revision walk setup failed");
699         revs.diffopt.format_callback = show_filemodify;
700         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
701         while ((commit = get_revision(&revs))) {
702                 if (has_unshown_parent(commit)) {
703                         add_object_array(&commit->object, NULL, &commits);
704                 }
705                 else {
706                         handle_commit(commit, &revs);
707                         handle_tail(&commits, &revs);
708                 }
709         }
710
711         handle_tags_and_duplicates(&extra_refs);
712
713         if (export_filename)
714                 export_marks(export_filename);
715
716         if (use_done_feature)
717                 printf("done\n");
718
719         return 0;
720 }