diff: support reading a file from stdin via "-"
[git/git.git] / diff-lib.c
CommitLineData
be3cfa85
JH
1/*
2 * Copyright (C) 2005 Junio C Hamano
3 */
86436c28 4#include "cache.h"
6fb737be 5#include "quote.h"
6973dcae 6#include "commit.h"
86436c28 7#include "diff.h"
427dcb4b 8#include "diffcore.h"
6973dcae 9#include "revision.h"
1cfe7733 10#include "cache-tree.h"
d516c2d1 11#include "path-list.h"
427dcb4b 12
b46f0b6d 13/*
6973dcae 14 * diff-files
b46f0b6d 15 */
f0c6b2a2 16
d516c2d1
JS
17static int read_directory(const char *path, struct path_list *list)
18{
19 DIR *dir;
20 struct dirent *e;
21
22 if (!(dir = opendir(path)))
23 return error("Could not open directory %s", path);
24
25 while ((e = readdir(dir)))
26 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
27 path_list_insert(xstrdup(e->d_name), list);
28
29 closedir(dir);
30 return 0;
31}
32
33static int queue_diff(struct diff_options *o,
34 const char *name1, const char *name2)
35{
36 struct stat st;
37 int mode1 = 0, mode2 = 0;
38
39 if (name1) {
5332b2af
JS
40 if (!strcmp(name1, "-"))
41 mode1 = 0644;
42 else if (stat(name1, &st))
d516c2d1 43 return error("Could not access '%s'", name1);
5332b2af
JS
44 else
45 mode1 = st.st_mode;
d516c2d1
JS
46 }
47 if (name2) {
5332b2af
JS
48 if (!strcmp(name2, "-"))
49 mode2 = 0644;
50 else if (stat(name2, &st))
646b3299 51 return error("Could not access '%s'", name2);
5332b2af
JS
52 else
53 mode2 = st.st_mode;
d516c2d1
JS
54 }
55
56 if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
57 return error("file/directory conflict: %s, %s", name1, name2);
58
59 if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
60 char buffer1[PATH_MAX], buffer2[PATH_MAX];
61 struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
62 int len1 = 0, len2 = 0, i1, i2, ret = 0;
63
64 if (name1 && read_directory(name1, &p1))
65 return -1;
66 if (name2 && read_directory(name2, &p2)) {
67 path_list_clear(&p1, 0);
68 return -1;
69 }
70
71 if (name1) {
72 len1 = strlen(name1);
73 if (len1 > 0 && name1[len1 - 1] == '/')
74 len1--;
75 memcpy(buffer1, name1, len1);
76 buffer1[len1++] = '/';
77 }
78
79 if (name2) {
80 len2 = strlen(name2);
81 if (len2 > 0 && name2[len2 - 1] == '/')
82 len2--;
83 memcpy(buffer2, name2, len2);
84 buffer2[len2++] = '/';
85 }
86
87 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
88 const char *n1, *n2;
89 int comp;
90
91 if (i1 == p1.nr)
92 comp = 1;
93 else if (i2 == p2.nr)
94 comp = -1;
95 else
96 comp = strcmp(p1.items[i1].path,
97 p2.items[i2].path);
98
99 if (comp > 0)
100 n1 = NULL;
101 else {
102 n1 = buffer1;
103 strncpy(buffer1 + len1, p1.items[i1++].path,
104 PATH_MAX - len1);
105 }
106
107 if (comp < 0)
108 n2 = NULL;
109 else {
110 n2 = buffer2;
111 strncpy(buffer2 + len2, p2.items[i2++].path,
112 PATH_MAX - len2);
113 }
114
115 ret = queue_diff(o, n1, n2);
116 }
117 path_list_clear(&p1, 0);
118 path_list_clear(&p2, 0);
119
120 return ret;
121 } else {
122 struct diff_filespec *d1, *d2;
123
124 if (o->reverse_diff) {
125 unsigned tmp;
126 const char *tmp_c;
127 tmp = mode1; mode1 = mode2; mode2 = tmp;
128 tmp_c = name1; name1 = name2; name2 = tmp_c;
129 }
130
131 if (!name1)
132 name1 = "/dev/null";
133 if (!name2)
134 name2 = "/dev/null";
135 d1 = alloc_filespec(name1);
136 d2 = alloc_filespec(name2);
137 fill_filespec(d1, null_sha1, mode1);
138 fill_filespec(d2, null_sha1, mode2);
139
140 diff_queue(&diff_queued_diff, d1, d2);
141 return 0;
142 }
143}
144
145static int is_in_index(const char *path)
146{
147 int len = strlen(path);
148 int pos = cache_name_pos(path, len);
149 char c;
150
151 if (pos < 0)
152 return 0;
153 if (strncmp(active_cache[pos]->name, path, len))
154 return 0;
155 c = active_cache[pos]->name[len];
156 return c == '\0' || c == '/';
157}
158
159static int handle_diff_files_args(struct rev_info *revs,
160 int argc, const char **argv, int *silent)
161{
162 *silent = 0;
163
164 /* revs->max_count == -2 means --no-index */
165 while (1 < argc && argv[1][0] == '-') {
166 if (!strcmp(argv[1], "--base"))
167 revs->max_count = 1;
168 else if (!strcmp(argv[1], "--ours"))
169 revs->max_count = 2;
170 else if (!strcmp(argv[1], "--theirs"))
171 revs->max_count = 3;
172 else if (!strcmp(argv[1], "-n") ||
173 !strcmp(argv[1], "--no-index"))
174 revs->max_count = -2;
175 else if (!strcmp(argv[1], "-q"))
176 *silent = 1;
177 else
178 return error("invalid option: %s", argv[1]);
179 argv++; argc--;
180 }
181
182 if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
183 /*
184 * If two files are specified, and at least one is untracked,
185 * default to no-index.
186 */
187 read_cache();
188 if (!is_in_index(revs->diffopt.paths[0]) ||
189 !is_in_index(revs->diffopt.paths[1]))
190 revs->max_count = -2;
191 }
192
193 /*
194 * Make sure there are NO revision (i.e. pending object) parameter,
195 * rev.max_count is reasonable (0 <= n <= 3),
196 * there is no other revision filtering parameters.
197 */
198 if (revs->pending.nr || revs->max_count > 3 ||
199 revs->min_age != -1 || revs->max_age != -1)
200 return error("no revision allowed with diff-files");
201
202 if (revs->max_count == -1 &&
203 (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
204 revs->combine_merges = revs->dense_combined_merges = 1;
205
206 return 0;
207}
208
fcfa33ec
JS
209static int is_outside_repo(const char *path, int nongit, const char *prefix)
210{
211 int i;
212 if (nongit || !strcmp(path, "-") || path[0] == '/')
213 return 1;
214 if (prefixcmp(path, "../"))
215 return 0;
216 if (!prefix)
217 return 1;
218 for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
219 while (i > 0 && prefix[i - 1] != '/')
220 i--;
221 if (--i < 0)
222 return 1;
223 path += 3;
224 }
225 return 0;
226}
227
228int setup_diff_no_index(struct rev_info *revs,
229 int argc, const char ** argv, int nongit, const char *prefix)
230{
231 int i;
232 for (i = 1; i < argc; i++)
5332b2af 233 if (argv[i][0] != '-' || argv[i][1] == '\0')
fcfa33ec
JS
234 break;
235 else if (!strcmp(argv[i], "--")) {
236 i++;
237 break;
238 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
239 i = argc - 3;
240 break;
241 }
242 if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
243 !is_outside_repo(argv[i], nongit, prefix)))
244 return -1;
245
246 diff_setup(&revs->diffopt);
247 for (i = 1; i < argc - 2; )
248 if (!strcmp(argv[i], "--no-index"))
249 i++;
250 else {
251 int j = diff_opt_parse(&revs->diffopt,
252 argv + i, argc - i);
253 if (!j)
254 die("invalid diff option/value: %s", argv[i]);
255 i += j;
256 }
ae792aa5
JH
257
258 if (prefix) {
259 int len = strlen(prefix);
260
261 revs->diffopt.paths = xcalloc(2, sizeof(char*));
262 for (i = 0; i < 2; i++) {
263 const char *p;
264 p = prefix_filename(prefix, len, argv[argc - 2 + i]);
265 revs->diffopt.paths[i] = xstrdup(p);
266 }
267 }
268 else
269 revs->diffopt.paths = argv + argc - 2;
fcfa33ec
JS
270 revs->diffopt.nr_paths = 2;
271 revs->max_count = -2;
272 return 0;
273}
274
d516c2d1
JS
275int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
276{
277 int silent_on_removed;
278
279 if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
280 return -1;
281
282 if (revs->max_count == -2) {
283 if (revs->diffopt.nr_paths != 2)
284 return error("need two files/directories with --no-index");
34a5e1a2
JS
285 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
286 revs->diffopt.paths[1]))
287 return -1;
d516c2d1
JS
288 diffcore_std(&revs->diffopt);
289 diff_flush(&revs->diffopt);
34a5e1a2
JS
290 /*
291 * The return code for --no-index imitates diff(1):
292 * 0 = no changes, 1 = changes, else error
293 */
294 return revs->diffopt.found_changes;
d516c2d1
JS
295 }
296
efdfd6c8
JH
297 if (read_cache() < 0) {
298 perror("read_cache");
299 return -1;
300 }
d516c2d1
JS
301 return run_diff_files(revs, silent_on_removed);
302}
303
6973dcae 304int run_diff_files(struct rev_info *revs, int silent_on_removed)
f0c6b2a2 305{
6973dcae
JH
306 int entries, i;
307 int diff_unmerged_stage = revs->max_count;
f0c6b2a2 308
6973dcae
JH
309 if (diff_unmerged_stage < 0)
310 diff_unmerged_stage = 2;
b4e1e4a7 311 entries = active_nr;
6973dcae 312 for (i = 0; i < entries; i++) {
be3cfa85 313 struct stat st;
6973dcae
JH
314 unsigned int oldmode, newmode;
315 struct cache_entry *ce = active_cache[i];
316 int changed;
8676eb43 317
6973dcae 318 if (!ce_path_match(ce, revs->prune_data))
8676eb43 319 continue;
be3cfa85 320
6973dcae 321 if (ce_stage(ce)) {
b4b15503 322 struct combine_diff_path *dpath;
6973dcae 323 int num_compare_stages = 0;
b4b15503 324 size_t path_len;
6973dcae 325
b4b15503
FF
326 path_len = ce_namelen(ce);
327
4fc970c4 328 dpath = xmalloc(combine_diff_path_size(5, path_len));
b4b15503
FF
329 dpath->path = (char *) &(dpath->parent[5]);
330
331 dpath->next = NULL;
332 dpath->len = path_len;
333 memcpy(dpath->path, ce->name, path_len);
334 dpath->path[path_len] = '\0';
a8e0d16d 335 hashclr(dpath->sha1);
b4b15503 336 memset(&(dpath->parent[0]), 0,
4fc970c4
JH
337 sizeof(struct combine_diff_parent)*5);
338
339 if (lstat(ce->name, &st) < 0) {
340 if (errno != ENOENT && errno != ENOTDIR) {
341 perror(ce->name);
342 continue;
343 }
344 if (silent_on_removed)
345 continue;
346 }
347 else
348 dpath->mode = canon_mode(st.st_mode);
6973dcae
JH
349
350 while (i < entries) {
351 struct cache_entry *nce = active_cache[i];
352 int stage;
353
354 if (strcmp(ce->name, nce->name))
355 break;
356
357 /* Stage #2 (ours) is the first parent,
358 * stage #3 (theirs) is the second.
359 */
360 stage = ce_stage(nce);
361 if (2 <= stage) {
362 int mode = ntohl(nce->ce_mode);
363 num_compare_stages++;
e702496e 364 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
b4b15503 365 dpath->parent[stage-2].mode =
6973dcae 366 canon_mode(mode);
b4b15503 367 dpath->parent[stage-2].status =
6973dcae
JH
368 DIFF_STATUS_MODIFIED;
369 }
370
371 /* diff against the proper unmerged stage */
372 if (stage == diff_unmerged_stage)
373 ce = nce;
374 i++;
375 }
376 /*
377 * Compensate for loop update
f0c6b2a2 378 */
6973dcae 379 i--;
6b5ee137 380
6973dcae 381 if (revs->combine_merges && num_compare_stages == 2) {
b4b15503 382 show_combined_diff(dpath, 2,
6973dcae
JH
383 revs->dense_combined_merges,
384 revs);
b4b15503 385 free(dpath);
6973dcae 386 continue;
1b1480ff 387 }
b4b15503
FF
388 free(dpath);
389 dpath = NULL;
0e3994fa 390
6973dcae
JH
391 /*
392 * Show the diff for the 'ce' if we found the one
393 * from the desired stage.
394 */
e9c84099 395 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
6973dcae
JH
396 if (ce_stage(ce) != diff_unmerged_stage)
397 continue;
eeaa4603 398 }
6b14d7fa 399
6973dcae
JH
400 if (lstat(ce->name, &st) < 0) {
401 if (errno != ENOENT && errno != ENOTDIR) {
402 perror(ce->name);
15d061b4
JH
403 continue;
404 }
6973dcae
JH
405 if (silent_on_removed)
406 continue;
407 diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
408 ce->sha1, ce->name, NULL);
409 continue;
f2ce9fde 410 }
6973dcae
JH
411 changed = ce_match_stat(ce, &st, 0);
412 if (!changed && !revs->diffopt.find_copies_harder)
413 continue;
414 oldmode = ntohl(ce->ce_mode);
be3cfa85 415
6973dcae
JH
416 newmode = canon_mode(st.st_mode);
417 if (!trust_executable_bit &&
418 S_ISREG(newmode) && S_ISREG(oldmode) &&
419 ((newmode ^ oldmode) == 0111))
420 newmode = oldmode;
421 diff_change(&revs->diffopt, oldmode, newmode,
422 ce->sha1, (changed ? null_sha1 : ce->sha1),
423 ce->name, NULL);
77eb2720 424
7ca45252 425 }
6973dcae
JH
426 diffcore_std(&revs->diffopt);
427 diff_flush(&revs->diffopt);
428 return 0;
77eb2720 429}
be3cfa85 430
e09ad6e1
JH
431/*
432 * diff-index
433 */
434
435/* A file entry went away or appeared */
436static void diff_index_show_file(struct rev_info *revs,
437 const char *prefix,
438 struct cache_entry *ce,
439 unsigned char *sha1, unsigned int mode)
440{
441 diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
442 sha1, ce->name, NULL);
443}
444
445static int get_stat_data(struct cache_entry *ce,
446 unsigned char **sha1p,
447 unsigned int *modep,
448 int cached, int match_missing)
449{
450 unsigned char *sha1 = ce->sha1;
451 unsigned int mode = ce->ce_mode;
452
453 if (!cached) {
454 static unsigned char no_sha1[20];
455 int changed;
456 struct stat st;
457 if (lstat(ce->name, &st) < 0) {
458 if (errno == ENOENT && match_missing) {
459 *sha1p = sha1;
460 *modep = mode;
461 return 0;
462 }
463 return -1;
464 }
465 changed = ce_match_stat(ce, &st, 0);
466 if (changed) {
185c975f 467 mode = ce_mode_from_stat(ce, st.st_mode);
e09ad6e1
JH
468 sha1 = no_sha1;
469 }
470 }
471
472 *sha1p = sha1;
473 *modep = mode;
474 return 0;
475}
476
477static void show_new_file(struct rev_info *revs,
478 struct cache_entry *new,
479 int cached, int match_missing)
480{
481 unsigned char *sha1;
482 unsigned int mode;
483
484 /* New file in the index: it might actually be different in
485 * the working copy.
486 */
487 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
488 return;
489
490 diff_index_show_file(revs, "+", new, sha1, mode);
491}
492
493static int show_modified(struct rev_info *revs,
494 struct cache_entry *old,
495 struct cache_entry *new,
496 int report_missing,
497 int cached, int match_missing)
498{
499 unsigned int mode, oldmode;
500 unsigned char *sha1;
501
502 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
503 if (report_missing)
504 diff_index_show_file(revs, "-", old,
505 old->sha1, old->ce_mode);
506 return -1;
507 }
508
cb2b9f5e
PM
509 if (revs->combine_merges && !cached &&
510 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
511 struct combine_diff_path *p;
512 int pathlen = ce_namelen(new);
513
514 p = xmalloc(combine_diff_path_size(2, pathlen));
515 p->path = (char *) &p->parent[2];
516 p->next = NULL;
517 p->len = pathlen;
518 memcpy(p->path, new->name, pathlen);
519 p->path[pathlen] = 0;
520 p->mode = ntohl(mode);
521 hashclr(p->sha1);
522 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
523 p->parent[0].status = DIFF_STATUS_MODIFIED;
524 p->parent[0].mode = ntohl(new->ce_mode);
525 hashcpy(p->parent[0].sha1, new->sha1);
526 p->parent[1].status = DIFF_STATUS_MODIFIED;
527 p->parent[1].mode = ntohl(old->ce_mode);
528 hashcpy(p->parent[1].sha1, old->sha1);
529 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
530 free(p);
531 return 0;
532 }
533
e09ad6e1 534 oldmode = old->ce_mode;
a89fccd2 535 if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
e09ad6e1
JH
536 !revs->diffopt.find_copies_harder)
537 return 0;
538
539 mode = ntohl(mode);
540 oldmode = ntohl(oldmode);
541
542 diff_change(&revs->diffopt, oldmode, mode,
543 old->sha1, sha1, old->name, NULL);
544 return 0;
545}
546
547static int diff_cache(struct rev_info *revs,
548 struct cache_entry **ac, int entries,
549 const char **pathspec,
550 int cached, int match_missing)
551{
552 while (entries) {
553 struct cache_entry *ce = *ac;
554 int same = (entries > 1) && ce_same_name(ce, ac[1]);
555
556 if (!ce_path_match(ce, pathspec))
557 goto skip_entry;
558
559 switch (ce_stage(ce)) {
560 case 0:
561 /* No stage 1 entry? That means it's a new file */
562 if (!same) {
563 show_new_file(revs, ce, cached, match_missing);
564 break;
565 }
566 /* Show difference between old and new */
1cfe7733 567 show_modified(revs, ac[1], ce, 1,
e09ad6e1
JH
568 cached, match_missing);
569 break;
570 case 1:
571 /* No stage 3 (merge) entry?
572 * That means it's been deleted.
573 */
574 if (!same) {
575 diff_index_show_file(revs, "-", ce,
576 ce->sha1, ce->ce_mode);
577 break;
578 }
579 /* We come here with ce pointing at stage 1
580 * (original tree) and ac[1] pointing at stage
581 * 3 (unmerged). show-modified with
582 * report-missing set to false does not say the
583 * file is deleted but reports true if work
584 * tree does not have it, in which case we
585 * fall through to report the unmerged state.
586 * Otherwise, we show the differences between
587 * the original tree and the work tree.
588 */
589 if (!cached &&
590 !show_modified(revs, ce, ac[1], 0,
591 cached, match_missing))
592 break;
e9c84099
JH
593 diff_unmerge(&revs->diffopt, ce->name,
594 ntohl(ce->ce_mode), ce->sha1);
595 break;
e09ad6e1 596 case 3:
e9c84099
JH
597 diff_unmerge(&revs->diffopt, ce->name,
598 0, null_sha1);
e09ad6e1
JH
599 break;
600
601 default:
602 die("impossible cache entry stage");
603 }
604
605skip_entry:
606 /*
607 * Ignore all the different stages for this file,
608 * we've handled the relevant cases now.
609 */
610 do {
611 ac++;
612 entries--;
613 } while (entries && ce_same_name(ce, ac[0]));
614 }
615 return 0;
616}
617
618/*
619 * This turns all merge entries into "stage 3". That guarantees that
620 * when we read in the new tree (into "stage 1"), we won't lose sight
621 * of the fact that we had unmerged entries.
622 */
623static void mark_merge_entries(void)
624{
625 int i;
626 for (i = 0; i < active_nr; i++) {
627 struct cache_entry *ce = active_cache[i];
628 if (!ce_stage(ce))
629 continue;
630 ce->ce_flags |= htons(CE_STAGEMASK);
631 }
632}
633
5c21ac0e 634int run_diff_index(struct rev_info *revs, int cached)
e09ad6e1
JH
635{
636 int ret;
637 struct object *ent;
638 struct tree *tree;
639 const char *tree_name;
5c21ac0e
JH
640 int match_missing = 0;
641
642 /*
643 * Backward compatibility wart - "diff-index -m" does
644 * not mean "do not ignore merges", but totally different.
645 */
646 if (!revs->ignore_merges)
647 match_missing = 1;
e09ad6e1 648
e09ad6e1
JH
649 mark_merge_entries();
650
1f1e895f
LT
651 ent = revs->pending.objects[0].item;
652 tree_name = revs->pending.objects[0].name;
e09ad6e1
JH
653 tree = parse_tree_indirect(ent->sha1);
654 if (!tree)
655 return error("bad tree object %s", tree_name);
656 if (read_tree(tree, 1, revs->prune_data))
657 return error("unable to read tree object %s", tree_name);
658 ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
659 cached, match_missing);
660 diffcore_std(&revs->diffopt);
661 diff_flush(&revs->diffopt);
662 return ret;
663}
1cfe7733
JH
664
665int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
666{
667 struct tree *tree;
668 struct rev_info revs;
669 int i;
670 struct cache_entry **dst;
671 struct cache_entry *last = NULL;
672
673 /*
674 * This is used by git-blame to run diff-cache internally;
675 * it potentially needs to repeatedly run this, so we will
676 * start by removing the higher order entries the last round
677 * left behind.
678 */
679 dst = active_cache;
680 for (i = 0; i < active_nr; i++) {
681 struct cache_entry *ce = active_cache[i];
682 if (ce_stage(ce)) {
683 if (last && !strcmp(ce->name, last->name))
684 continue;
685 cache_tree_invalidate_path(active_cache_tree,
686 ce->name);
687 last = ce;
688 ce->ce_mode = 0;
689 ce->ce_flags &= ~htons(CE_STAGEMASK);
690 }
691 *dst++ = ce;
692 }
693 active_nr = dst - active_cache;
694
695 init_revisions(&revs, NULL);
696 revs.prune_data = opt->paths;
697 tree = parse_tree_indirect(tree_sha1);
698 if (!tree)
699 die("bad tree object %s", sha1_to_hex(tree_sha1));
700 if (read_tree(tree, 1, opt->paths))
701 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
702 return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
703 1, 0);
704}