git-submodule - Add 'foreach' subcommand
[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 { VERBATIM, WARN, STRIP, ABORT } signed_tag_mode = ABORT;
27
28 static int parse_opt_signed_tag_mode(const struct option *opt,
29                                      const char *arg, int unset)
30 {
31         if (unset || !strcmp(arg, "abort"))
32                 signed_tag_mode = ABORT;
33         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
34                 signed_tag_mode = VERBATIM;
35         else if (!strcmp(arg, "warn"))
36                 signed_tag_mode = WARN;
37         else if (!strcmp(arg, "strip"))
38                 signed_tag_mode = STRIP;
39         else
40                 return error("Unknown signed-tag mode: %s", arg);
41         return 0;
42 }
43
44 static struct decoration idnums;
45 static uint32_t last_idnum;
46
47 static int has_unshown_parent(struct commit *commit)
48 {
49         struct commit_list *parent;
50
51         for (parent = commit->parents; parent; parent = parent->next)
52                 if (!(parent->item->object.flags & SHOWN) &&
53                     !(parent->item->object.flags & UNINTERESTING))
54                         return 1;
55         return 0;
56 }
57
58 /* Since intptr_t is C99, we do not use it here */
59 static inline uint32_t *mark_to_ptr(uint32_t mark)
60 {
61         return ((uint32_t *)NULL) + mark;
62 }
63
64 static inline uint32_t ptr_to_mark(void * mark)
65 {
66         return (uint32_t *)mark - (uint32_t *)NULL;
67 }
68
69 static inline void mark_object(struct object *object, uint32_t mark)
70 {
71         add_decoration(&idnums, object, mark_to_ptr(mark));
72 }
73
74 static inline void mark_next_object(struct object *object)
75 {
76         mark_object(object, ++last_idnum);
77 }
78
79 static int get_object_mark(struct object *object)
80 {
81         void *decoration = lookup_decoration(&idnums, object);
82         if (!decoration)
83                 return 0;
84         return ptr_to_mark(decoration);
85 }
86
87 static void show_progress(void)
88 {
89         static int counter = 0;
90         if (!progress)
91                 return;
92         if ((++counter % progress) == 0)
93                 printf("progress %d objects\n", counter);
94 }
95
96 static void handle_object(const unsigned char *sha1)
97 {
98         unsigned long size;
99         enum object_type type;
100         char *buf;
101         struct object *object;
102
103         if (is_null_sha1(sha1))
104                 return;
105
106         object = parse_object(sha1);
107         if (!object)
108                 die ("Could not read blob %s", sha1_to_hex(sha1));
109
110         if (object->flags & SHOWN)
111                 return;
112
113         buf = read_sha1_file(sha1, &type, &size);
114         if (!buf)
115                 die ("Could not read blob %s", sha1_to_hex(sha1));
116
117         mark_next_object(object);
118
119         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
120         if (size && fwrite(buf, size, 1, stdout) != 1)
121                 die ("Could not write blob %s", sha1_to_hex(sha1));
122         printf("\n");
123
124         show_progress();
125
126         object->flags |= SHOWN;
127         free(buf);
128 }
129
130 static void show_filemodify(struct diff_queue_struct *q,
131                             struct diff_options *options, void *data)
132 {
133         int i;
134         for (i = 0; i < q->nr; i++) {
135                 struct diff_filespec *ospec = q->queue[i]->one;
136                 struct diff_filespec *spec = q->queue[i]->two;
137
138                 switch (q->queue[i]->status) {
139                 case DIFF_STATUS_DELETED:
140                         printf("D %s\n", spec->path);
141                         break;
142
143                 case DIFF_STATUS_COPIED:
144                 case DIFF_STATUS_RENAMED:
145                         printf("%c \"%s\" \"%s\"\n", q->queue[i]->status,
146                                ospec->path, spec->path);
147
148                         if (!hashcmp(ospec->sha1, spec->sha1) &&
149                             ospec->mode == spec->mode)
150                                 break;
151                         /* fallthrough */
152
153                 case DIFF_STATUS_TYPE_CHANGED:
154                 case DIFF_STATUS_MODIFIED:
155                 case DIFF_STATUS_ADDED:
156                         /*
157                          * Links refer to objects in another repositories;
158                          * output the SHA-1 verbatim.
159                          */
160                         if (S_ISGITLINK(spec->mode))
161                                 printf("M %06o %s %s\n", spec->mode,
162                                        sha1_to_hex(spec->sha1), spec->path);
163                         else {
164                                 struct object *object = lookup_object(spec->sha1);
165                                 printf("M %06o :%d %s\n", spec->mode,
166                                        get_object_mark(object), spec->path);
167                         }
168                         break;
169
170                 default:
171                         die("Unexpected comparison status '%c' for %s, %s",
172                                 q->queue[i]->status,
173                                 ospec->path ? ospec->path : "none",
174                                 spec->path ? spec->path : "none");
175                 }
176         }
177 }
178
179 static const char *find_encoding(const char *begin, const char *end)
180 {
181         const char *needle = "\nencoding ";
182         char *bol, *eol;
183
184         bol = memmem(begin, end ? end - begin : strlen(begin),
185                      needle, strlen(needle));
186         if (!bol)
187                 return git_commit_encoding;
188         bol += strlen(needle);
189         eol = strchrnul(bol, '\n');
190         *eol = '\0';
191         return bol;
192 }
193
194 static void handle_commit(struct commit *commit, struct rev_info *rev)
195 {
196         int saved_output_format = rev->diffopt.output_format;
197         const char *author, *author_end, *committer, *committer_end;
198         const char *encoding, *message;
199         char *reencoded = NULL;
200         struct commit_list *p;
201         int i;
202
203         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
204
205         parse_commit(commit);
206         author = strstr(commit->buffer, "\nauthor ");
207         if (!author)
208                 die ("Could not find author in commit %s",
209                      sha1_to_hex(commit->object.sha1));
210         author++;
211         author_end = strchrnul(author, '\n');
212         committer = strstr(author_end, "\ncommitter ");
213         if (!committer)
214                 die ("Could not find committer in commit %s",
215                      sha1_to_hex(commit->object.sha1));
216         committer++;
217         committer_end = strchrnul(committer, '\n');
218         message = strstr(committer_end, "\n\n");
219         encoding = find_encoding(committer_end, message);
220         if (message)
221                 message += 2;
222
223         if (commit->parents) {
224                 parse_commit(commit->parents->item);
225                 diff_tree_sha1(commit->parents->item->tree->object.sha1,
226                                commit->tree->object.sha1, "", &rev->diffopt);
227         }
228         else
229                 diff_root_tree_sha1(commit->tree->object.sha1,
230                                     "", &rev->diffopt);
231
232         /* Export the referenced blobs, and remember the marks. */
233         for (i = 0; i < diff_queued_diff.nr; i++)
234                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
235                         handle_object(diff_queued_diff.queue[i]->two->sha1);
236
237         mark_next_object(&commit->object);
238         if (!is_encoding_utf8(encoding))
239                 reencoded = reencode_string(message, "UTF-8", encoding);
240         if (!commit->parents)
241                 printf("reset %s\n", (const char*)commit->util);
242         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
243                (const char *)commit->util, last_idnum,
244                (int)(author_end - author), author,
245                (int)(committer_end - committer), committer,
246                (unsigned)(reencoded
247                           ? strlen(reencoded) : message
248                           ? strlen(message) : 0),
249                reencoded ? reencoded : message ? message : "");
250         free(reencoded);
251
252         for (i = 0, p = commit->parents; p; p = p->next) {
253                 int mark = get_object_mark(&p->item->object);
254                 if (!mark)
255                         continue;
256                 if (i == 0)
257                         printf("from :%d\n", mark);
258                 else
259                         printf("merge :%d\n", mark);
260                 i++;
261         }
262
263         log_tree_diff_flush(rev);
264         rev->diffopt.output_format = saved_output_format;
265
266         printf("\n");
267
268         show_progress();
269 }
270
271 static void handle_tail(struct object_array *commits, struct rev_info *revs)
272 {
273         struct commit *commit;
274         while (commits->nr) {
275                 commit = (struct commit *)commits->objects[commits->nr - 1].item;
276                 if (has_unshown_parent(commit))
277                         return;
278                 handle_commit(commit, revs);
279                 commits->nr--;
280         }
281 }
282
283 static void handle_tag(const char *name, struct tag *tag)
284 {
285         unsigned long size;
286         enum object_type type;
287         char *buf;
288         const char *tagger, *tagger_end, *message;
289         size_t message_size = 0;
290
291         buf = read_sha1_file(tag->object.sha1, &type, &size);
292         if (!buf)
293                 die ("Could not read tag %s", sha1_to_hex(tag->object.sha1));
294         message = memmem(buf, size, "\n\n", 2);
295         if (message) {
296                 message += 2;
297                 message_size = strlen(message);
298         }
299         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
300         if (!tagger)
301                 die ("No tagger for tag %s", sha1_to_hex(tag->object.sha1));
302         tagger++;
303         tagger_end = strchrnul(tagger, '\n');
304
305         /* handle signed tags */
306         if (message) {
307                 const char *signature = strstr(message,
308                                                "\n-----BEGIN PGP SIGNATURE-----\n");
309                 if (signature)
310                         switch(signed_tag_mode) {
311                         case ABORT:
312                                 die ("Encountered signed tag %s; use "
313                                      "--signed-tag=<mode> to handle it.",
314                                      sha1_to_hex(tag->object.sha1));
315                         case WARN:
316                                 warning ("Exporting signed tag %s",
317                                          sha1_to_hex(tag->object.sha1));
318                                 /* fallthru */
319                         case VERBATIM:
320                                 break;
321                         case STRIP:
322                                 message_size = signature + 1 - message;
323                                 break;
324                         }
325         }
326
327         if (!prefixcmp(name, "refs/tags/"))
328                 name += 10;
329         printf("tag %s\nfrom :%d\n%.*s\ndata %d\n%.*s\n",
330                name, get_object_mark(tag->tagged),
331                (int)(tagger_end - tagger), tagger,
332                (int)message_size, (int)message_size, message ? message : "");
333 }
334
335 static void get_tags_and_duplicates(struct object_array *pending,
336                                     struct string_list *extra_refs)
337 {
338         struct tag *tag;
339         int i;
340
341         for (i = 0; i < pending->nr; i++) {
342                 struct object_array_entry *e = pending->objects + i;
343                 unsigned char sha1[20];
344                 struct commit *commit = commit;
345                 char *full_name;
346
347                 if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
348                         continue;
349
350                 switch (e->item->type) {
351                 case OBJ_COMMIT:
352                         commit = (struct commit *)e->item;
353                         break;
354                 case OBJ_TAG:
355                         tag = (struct tag *)e->item;
356                         while (tag && tag->object.type == OBJ_TAG) {
357                                 string_list_insert(full_name, extra_refs)->util = tag;
358                                 tag = (struct tag *)tag->tagged;
359                         }
360                         if (!tag)
361                                 die ("Tag %s points nowhere?", e->name);
362                         switch(tag->object.type) {
363                         case OBJ_COMMIT:
364                                 commit = (struct commit *)tag;
365                                 break;
366                         case OBJ_BLOB:
367                                 handle_object(tag->object.sha1);
368                                 continue;
369                         }
370                         break;
371                 default:
372                         die ("Unexpected object of type %s",
373                              typename(e->item->type));
374                 }
375                 if (commit->util)
376                         /* more than one name for the same object */
377                         string_list_insert(full_name, extra_refs)->util = commit;
378                 else
379                         commit->util = full_name;
380         }
381 }
382
383 static void handle_tags_and_duplicates(struct string_list *extra_refs)
384 {
385         struct commit *commit;
386         int i;
387
388         for (i = extra_refs->nr - 1; i >= 0; i--) {
389                 const char *name = extra_refs->items[i].string;
390                 struct object *object = extra_refs->items[i].util;
391                 switch (object->type) {
392                 case OBJ_TAG:
393                         handle_tag(name, (struct tag *)object);
394                         break;
395                 case OBJ_COMMIT:
396                         /* create refs pointing to already seen commits */
397                         commit = (struct commit *)object;
398                         printf("reset %s\nfrom :%d\n\n", name,
399                                get_object_mark(&commit->object));
400                         show_progress();
401                         break;
402                 }
403         }
404 }
405
406 static void export_marks(char *file)
407 {
408         unsigned int i;
409         uint32_t mark;
410         struct object_decoration *deco = idnums.hash;
411         FILE *f;
412
413         f = fopen(file, "w");
414         if (!f)
415                 error("Unable to open marks file %s for writing", file);
416
417         for (i = 0; i < idnums.size; i++) {
418                 if (deco->base && deco->base->type == 1) {
419                         mark = ptr_to_mark(deco->decoration);
420                         fprintf(f, ":%u %s\n", mark, sha1_to_hex(deco->base->sha1));
421                 }
422                 deco++;
423         }
424
425         if (ferror(f) || fclose(f))
426                 error("Unable to write marks file %s.", file);
427 }
428
429 static void import_marks(char *input_file)
430 {
431         char line[512];
432         FILE *f = fopen(input_file, "r");
433         if (!f)
434                 die("cannot read %s: %s", input_file, strerror(errno));
435
436         while (fgets(line, sizeof(line), f)) {
437                 uint32_t mark;
438                 char *line_end, *mark_end;
439                 unsigned char sha1[20];
440                 struct object *object;
441
442                 line_end = strchr(line, '\n');
443                 if (line[0] != ':' || !line_end)
444                         die("corrupt mark line: %s", line);
445                 *line_end = '\0';
446
447                 mark = strtoumax(line + 1, &mark_end, 10);
448                 if (!mark || mark_end == line + 1
449                         || *mark_end != ' ' || get_sha1(mark_end + 1, sha1))
450                         die("corrupt mark line: %s", line);
451
452                 object = parse_object(sha1);
453                 if (!object)
454                         die ("Could not read blob %s", sha1_to_hex(sha1));
455
456                 if (object->flags & SHOWN)
457                         error("Object %s already has a mark", sha1);
458
459                 mark_object(object, mark);
460                 if (last_idnum < mark)
461                         last_idnum = mark;
462
463                 object->flags |= SHOWN;
464         }
465         fclose(f);
466 }
467
468 int cmd_fast_export(int argc, const char **argv, const char *prefix)
469 {
470         struct rev_info revs;
471         struct object_array commits = { 0, 0, NULL };
472         struct string_list extra_refs = { NULL, 0, 0, 0 };
473         struct commit *commit;
474         char *export_filename = NULL, *import_filename = NULL;
475         struct option options[] = {
476                 OPT_INTEGER(0, "progress", &progress,
477                             "show progress after <n> objects"),
478                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, "mode",
479                              "select handling of signed tags",
480                              parse_opt_signed_tag_mode),
481                 OPT_STRING(0, "export-marks", &export_filename, "FILE",
482                              "Dump marks to this file"),
483                 OPT_STRING(0, "import-marks", &import_filename, "FILE",
484                              "Import marks from this file"),
485                 OPT_END()
486         };
487
488         /* we handle encodings */
489         git_config(git_default_config, NULL);
490
491         init_revisions(&revs, prefix);
492         argc = setup_revisions(argc, argv, &revs, NULL);
493         argc = parse_options(argc, argv, options, fast_export_usage, 0);
494         if (argc > 1)
495                 usage_with_options (fast_export_usage, options);
496
497         if (import_filename)
498                 import_marks(import_filename);
499
500         get_tags_and_duplicates(&revs.pending, &extra_refs);
501
502         if (prepare_revision_walk(&revs))
503                 die("revision walk setup failed");
504         revs.diffopt.format_callback = show_filemodify;
505         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
506         while ((commit = get_revision(&revs))) {
507                 if (has_unshown_parent(commit)) {
508                         struct commit_list *parent = commit->parents;
509                         add_object_array(&commit->object, NULL, &commits);
510                         for (; parent; parent = parent->next)
511                                 if (!parent->item->util)
512                                         parent->item->util = commit->util;
513                 }
514                 else {
515                         handle_commit(commit, &revs);
516                         handle_tail(&commits, &revs);
517                 }
518         }
519
520         handle_tags_and_duplicates(&extra_refs);
521
522         if (export_filename)
523                 export_marks(export_filename);
524
525         return 0;
526 }