f1cc3fd5101268f4766c723eb2a854ddddb715ae
[git/git.git] / diff-lib.c
1 /*
2 * Copyright (C) 2005 Junio C Hamano
3 */
4 #include "cache.h"
5 #include "quote.h"
6 #include "commit.h"
7 #include "diff.h"
8 #include "diffcore.h"
9 #include "revision.h"
10 #include "cache-tree.h"
11 #include "unpack-trees.h"
12 #include "refs.h"
13 #include "submodule.h"
14 #include "dir.h"
15
16 /*
17 * diff-files
18 */
19
20 /*
21 * Has the work tree entity been removed?
22 *
23 * Return 1 if it was removed from the work tree, 0 if an entity to be
24 * compared with the cache entry ce still exists (the latter includes
25 * the case where a directory that is not a submodule repository
26 * exists for ce that is a submodule -- it is a submodule that is not
27 * checked out). Return negative for an error.
28 */
29 static int check_removed(const struct cache_entry *ce, struct stat *st)
30 {
31 if (lstat(ce->name, st) < 0) {
32 if (!is_missing_file_error(errno))
33 return -1;
34 return 1;
35 }
36 if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
37 return 1;
38 if (S_ISDIR(st->st_mode)) {
39 unsigned char sub[20];
40
41 /*
42 * If ce is already a gitlink, we can have a plain
43 * directory (i.e. the submodule is not checked out),
44 * or a checked out submodule. Either case this is not
45 * a case where something was removed from the work tree,
46 * so we will return 0.
47 *
48 * Otherwise, if the directory is not a submodule
49 * repository, that means ce which was a blob turned into
50 * a directory --- the blob was removed!
51 */
52 if (!S_ISGITLINK(ce->ce_mode) &&
53 resolve_gitlink_ref(ce->name, "HEAD", sub))
54 return 1;
55 }
56 return 0;
57 }
58
59 /*
60 * Has a file changed or has a submodule new commits or a dirty work tree?
61 *
62 * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
63 * option is set, the caller does not only want to know if a submodule is
64 * modified at all but wants to know all the conditions that are met (new
65 * commits, untracked content and/or modified content).
66 */
67 static int match_stat_with_submodule(struct diff_options *diffopt,
68 const struct cache_entry *ce,
69 struct stat *st, unsigned ce_option,
70 unsigned *dirty_submodule)
71 {
72 int changed = ce_match_stat(ce, st, ce_option);
73 if (S_ISGITLINK(ce->ce_mode)) {
74 struct diff_flags orig_flags = diffopt->flags;
75 if (!diffopt->flags.OVERRIDE_SUBMODULE_CONFIG)
76 set_diffopt_flags_from_submodule_config(diffopt, ce->name);
77 if (diffopt->flags.IGNORE_SUBMODULES)
78 changed = 0;
79 else if (!diffopt->flags.IGNORE_DIRTY_SUBMODULES &&
80 (!changed || diffopt->flags.DIRTY_SUBMODULES))
81 *dirty_submodule = is_submodule_modified(ce->name,
82 diffopt->flags.IGNORE_UNTRACKED_IN_SUBMODULES);
83 diffopt->flags = orig_flags;
84 }
85 return changed;
86 }
87
88 int run_diff_files(struct rev_info *revs, unsigned int option)
89 {
90 int entries, i;
91 int diff_unmerged_stage = revs->max_count;
92 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
93 ? CE_MATCH_RACY_IS_DIRTY : 0);
94
95 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
96
97 if (diff_unmerged_stage < 0)
98 diff_unmerged_stage = 2;
99 entries = active_nr;
100 for (i = 0; i < entries; i++) {
101 unsigned int oldmode, newmode;
102 struct cache_entry *ce = active_cache[i];
103 int changed;
104 unsigned dirty_submodule = 0;
105 const struct object_id *old_oid, *new_oid;
106
107 if (diff_can_quit_early(&revs->diffopt))
108 break;
109
110 if (!ce_path_match(ce, &revs->prune_data, NULL))
111 continue;
112
113 if (ce_stage(ce)) {
114 struct combine_diff_path *dpath;
115 struct diff_filepair *pair;
116 unsigned int wt_mode = 0;
117 int num_compare_stages = 0;
118 size_t path_len;
119 struct stat st;
120
121 path_len = ce_namelen(ce);
122
123 dpath = xmalloc(combine_diff_path_size(5, path_len));
124 dpath->path = (char *) &(dpath->parent[5]);
125
126 dpath->next = NULL;
127 memcpy(dpath->path, ce->name, path_len);
128 dpath->path[path_len] = '\0';
129 oidclr(&dpath->oid);
130 memset(&(dpath->parent[0]), 0,
131 sizeof(struct combine_diff_parent)*5);
132
133 changed = check_removed(ce, &st);
134 if (!changed)
135 wt_mode = ce_mode_from_stat(ce, st.st_mode);
136 else {
137 if (changed < 0) {
138 perror(ce->name);
139 continue;
140 }
141 wt_mode = 0;
142 }
143 dpath->mode = wt_mode;
144
145 while (i < entries) {
146 struct cache_entry *nce = active_cache[i];
147 int stage;
148
149 if (strcmp(ce->name, nce->name))
150 break;
151
152 /* Stage #2 (ours) is the first parent,
153 * stage #3 (theirs) is the second.
154 */
155 stage = ce_stage(nce);
156 if (2 <= stage) {
157 int mode = nce->ce_mode;
158 num_compare_stages++;
159 oidcpy(&dpath->parent[stage - 2].oid,
160 &nce->oid);
161 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
162 dpath->parent[stage-2].status =
163 DIFF_STATUS_MODIFIED;
164 }
165
166 /* diff against the proper unmerged stage */
167 if (stage == diff_unmerged_stage)
168 ce = nce;
169 i++;
170 }
171 /*
172 * Compensate for loop update
173 */
174 i--;
175
176 if (revs->combine_merges && num_compare_stages == 2) {
177 show_combined_diff(dpath, 2,
178 revs->dense_combined_merges,
179 revs);
180 free(dpath);
181 continue;
182 }
183 FREE_AND_NULL(dpath);
184
185 /*
186 * Show the diff for the 'ce' if we found the one
187 * from the desired stage.
188 */
189 pair = diff_unmerge(&revs->diffopt, ce->name);
190 if (wt_mode)
191 pair->two->mode = wt_mode;
192 if (ce_stage(ce) != diff_unmerged_stage)
193 continue;
194 }
195
196 if (ce_uptodate(ce) || ce_skip_worktree(ce))
197 continue;
198
199 /* If CE_VALID is set, don't look at workdir for file removal */
200 if (ce->ce_flags & CE_VALID) {
201 changed = 0;
202 newmode = ce->ce_mode;
203 } else {
204 struct stat st;
205
206 changed = check_removed(ce, &st);
207 if (changed) {
208 if (changed < 0) {
209 perror(ce->name);
210 continue;
211 }
212 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
213 &ce->oid,
214 !is_null_oid(&ce->oid),
215 ce->name, 0);
216 continue;
217 } else if (revs->diffopt.ita_invisible_in_index &&
218 ce_intent_to_add(ce)) {
219 diff_addremove(&revs->diffopt, '+', ce->ce_mode,
220 &empty_tree_oid, 0,
221 ce->name, 0);
222 continue;
223 }
224
225 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
226 ce_option, &dirty_submodule);
227 newmode = ce_mode_from_stat(ce, st.st_mode);
228 }
229
230 if (!changed && !dirty_submodule) {
231 ce_mark_uptodate(ce);
232 if (!revs->diffopt.flags.FIND_COPIES_HARDER)
233 continue;
234 }
235 oldmode = ce->ce_mode;
236 old_oid = &ce->oid;
237 new_oid = changed ? &null_oid : &ce->oid;
238 diff_change(&revs->diffopt, oldmode, newmode,
239 old_oid, new_oid,
240 !is_null_oid(old_oid),
241 !is_null_oid(new_oid),
242 ce->name, 0, dirty_submodule);
243
244 }
245 diffcore_std(&revs->diffopt);
246 diff_flush(&revs->diffopt);
247 return 0;
248 }
249
250 /*
251 * diff-index
252 */
253
254 /* A file entry went away or appeared */
255 static void diff_index_show_file(struct rev_info *revs,
256 const char *prefix,
257 const struct cache_entry *ce,
258 const struct object_id *oid, int oid_valid,
259 unsigned int mode,
260 unsigned dirty_submodule)
261 {
262 diff_addremove(&revs->diffopt, prefix[0], mode,
263 oid, oid_valid, ce->name, dirty_submodule);
264 }
265
266 static int get_stat_data(const struct cache_entry *ce,
267 const struct object_id **oidp,
268 unsigned int *modep,
269 int cached, int match_missing,
270 unsigned *dirty_submodule, struct diff_options *diffopt)
271 {
272 const struct object_id *oid = &ce->oid;
273 unsigned int mode = ce->ce_mode;
274
275 if (!cached && !ce_uptodate(ce)) {
276 int changed;
277 struct stat st;
278 changed = check_removed(ce, &st);
279 if (changed < 0)
280 return -1;
281 else if (changed) {
282 if (match_missing) {
283 *oidp = oid;
284 *modep = mode;
285 return 0;
286 }
287 return -1;
288 }
289 changed = match_stat_with_submodule(diffopt, ce, &st,
290 0, dirty_submodule);
291 if (changed) {
292 mode = ce_mode_from_stat(ce, st.st_mode);
293 oid = &null_oid;
294 }
295 }
296
297 *oidp = oid;
298 *modep = mode;
299 return 0;
300 }
301
302 static void show_new_file(struct rev_info *revs,
303 const struct cache_entry *new,
304 int cached, int match_missing)
305 {
306 const struct object_id *oid;
307 unsigned int mode;
308 unsigned dirty_submodule = 0;
309
310 /*
311 * New file in the index: it might actually be different in
312 * the working tree.
313 */
314 if (get_stat_data(new, &oid, &mode, cached, match_missing,
315 &dirty_submodule, &revs->diffopt) < 0)
316 return;
317
318 diff_index_show_file(revs, "+", new, oid, !is_null_oid(oid), mode, dirty_submodule);
319 }
320
321 static int show_modified(struct rev_info *revs,
322 const struct cache_entry *old,
323 const struct cache_entry *new,
324 int report_missing,
325 int cached, int match_missing)
326 {
327 unsigned int mode, oldmode;
328 const struct object_id *oid;
329 unsigned dirty_submodule = 0;
330
331 if (get_stat_data(new, &oid, &mode, cached, match_missing,
332 &dirty_submodule, &revs->diffopt) < 0) {
333 if (report_missing)
334 diff_index_show_file(revs, "-", old,
335 &old->oid, 1, old->ce_mode,
336 0);
337 return -1;
338 }
339
340 if (revs->combine_merges && !cached &&
341 (oidcmp(oid, &old->oid) || oidcmp(&old->oid, &new->oid))) {
342 struct combine_diff_path *p;
343 int pathlen = ce_namelen(new);
344
345 p = xmalloc(combine_diff_path_size(2, pathlen));
346 p->path = (char *) &p->parent[2];
347 p->next = NULL;
348 memcpy(p->path, new->name, pathlen);
349 p->path[pathlen] = 0;
350 p->mode = mode;
351 oidclr(&p->oid);
352 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
353 p->parent[0].status = DIFF_STATUS_MODIFIED;
354 p->parent[0].mode = new->ce_mode;
355 oidcpy(&p->parent[0].oid, &new->oid);
356 p->parent[1].status = DIFF_STATUS_MODIFIED;
357 p->parent[1].mode = old->ce_mode;
358 oidcpy(&p->parent[1].oid, &old->oid);
359 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
360 free(p);
361 return 0;
362 }
363
364 oldmode = old->ce_mode;
365 if (mode == oldmode && !oidcmp(oid, &old->oid) && !dirty_submodule &&
366 !revs->diffopt.flags.FIND_COPIES_HARDER)
367 return 0;
368
369 diff_change(&revs->diffopt, oldmode, mode,
370 &old->oid, oid, 1, !is_null_oid(oid),
371 old->name, 0, dirty_submodule);
372 return 0;
373 }
374
375 /*
376 * This gets a mix of an existing index and a tree, one pathname entry
377 * at a time. The index entry may be a single stage-0 one, but it could
378 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
379 * give you the position and number of entries in the index).
380 */
381 static void do_oneway_diff(struct unpack_trees_options *o,
382 const struct cache_entry *idx,
383 const struct cache_entry *tree)
384 {
385 struct rev_info *revs = o->unpack_data;
386 int match_missing, cached;
387
388 /* i-t-a entries do not actually exist in the index */
389 if (revs->diffopt.ita_invisible_in_index &&
390 idx && ce_intent_to_add(idx)) {
391 idx = NULL;
392 if (!tree)
393 return; /* nothing to diff.. */
394 }
395
396 /* if the entry is not checked out, don't examine work tree */
397 cached = o->index_only ||
398 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
399 /*
400 * Backward compatibility wart - "diff-index -m" does
401 * not mean "do not ignore merges", but "match_missing".
402 *
403 * But with the revision flag parsing, that's found in
404 * "!revs->ignore_merges".
405 */
406 match_missing = !revs->ignore_merges;
407
408 if (cached && idx && ce_stage(idx)) {
409 struct diff_filepair *pair;
410 pair = diff_unmerge(&revs->diffopt, idx->name);
411 if (tree)
412 fill_filespec(pair->one, &tree->oid, 1,
413 tree->ce_mode);
414 return;
415 }
416
417 /*
418 * Something added to the tree?
419 */
420 if (!tree) {
421 show_new_file(revs, idx, cached, match_missing);
422 return;
423 }
424
425 /*
426 * Something removed from the tree?
427 */
428 if (!idx) {
429 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
430 tree->ce_mode, 0);
431 return;
432 }
433
434 /* Show difference between old and new */
435 show_modified(revs, tree, idx, 1, cached, match_missing);
436 }
437
438 /*
439 * The unpack_trees() interface is designed for merging, so
440 * the different source entries are designed primarily for
441 * the source trees, with the old index being really mainly
442 * used for being replaced by the result.
443 *
444 * For diffing, the index is more important, and we only have a
445 * single tree.
446 *
447 * We're supposed to advance o->pos to skip what we have already processed.
448 *
449 * This wrapper makes it all more readable, and takes care of all
450 * the fairly complex unpack_trees() semantic requirements, including
451 * the skipping, the path matching, the type conflict cases etc.
452 */
453 static int oneway_diff(const struct cache_entry * const *src,
454 struct unpack_trees_options *o)
455 {
456 const struct cache_entry *idx = src[0];
457 const struct cache_entry *tree = src[1];
458 struct rev_info *revs = o->unpack_data;
459
460 /*
461 * Unpack-trees generates a DF/conflict entry if
462 * there was a directory in the index and a tree
463 * in the tree. From a diff standpoint, that's a
464 * delete of the tree and a create of the file.
465 */
466 if (tree == o->df_conflict_entry)
467 tree = NULL;
468
469 if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
470 do_oneway_diff(o, idx, tree);
471 if (diff_can_quit_early(&revs->diffopt)) {
472 o->exiting_early = 1;
473 return -1;
474 }
475 }
476
477 return 0;
478 }
479
480 static int diff_cache(struct rev_info *revs,
481 const struct object_id *tree_oid,
482 const char *tree_name,
483 int cached)
484 {
485 struct tree *tree;
486 struct tree_desc t;
487 struct unpack_trees_options opts;
488
489 tree = parse_tree_indirect(tree_oid);
490 if (!tree)
491 return error("bad tree object %s",
492 tree_name ? tree_name : oid_to_hex(tree_oid));
493 memset(&opts, 0, sizeof(opts));
494 opts.head_idx = 1;
495 opts.index_only = cached;
496 opts.diff_index_cached = (cached &&
497 !revs->diffopt.flags.FIND_COPIES_HARDER);
498 opts.merge = 1;
499 opts.fn = oneway_diff;
500 opts.unpack_data = revs;
501 opts.src_index = &the_index;
502 opts.dst_index = NULL;
503 opts.pathspec = &revs->diffopt.pathspec;
504 opts.pathspec->recursive = 1;
505
506 init_tree_desc(&t, tree->buffer, tree->size);
507 return unpack_trees(1, &t, &opts);
508 }
509
510 int run_diff_index(struct rev_info *revs, int cached)
511 {
512 struct object_array_entry *ent;
513
514 ent = revs->pending.objects;
515 if (diff_cache(revs, &ent->item->oid, ent->name, cached))
516 exit(128);
517
518 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
519 diffcore_fix_diff_index(&revs->diffopt);
520 diffcore_std(&revs->diffopt);
521 diff_flush(&revs->diffopt);
522 return 0;
523 }
524
525 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
526 {
527 struct rev_info revs;
528
529 init_revisions(&revs, NULL);
530 copy_pathspec(&revs.prune_data, &opt->pathspec);
531 revs.diffopt = *opt;
532
533 if (diff_cache(&revs, tree_oid, NULL, 1))
534 exit(128);
535 return 0;
536 }
537
538 int index_differs_from(const char *def, const struct diff_flags *flags,
539 int ita_invisible_in_index)
540 {
541 struct rev_info rev;
542 struct setup_revision_opt opt;
543
544 init_revisions(&rev, NULL);
545 memset(&opt, 0, sizeof(opt));
546 opt.def = def;
547 setup_revisions(0, NULL, &rev, &opt);
548 rev.diffopt.flags.QUICK = 1;
549 rev.diffopt.flags.EXIT_WITH_STATUS = 1;
550 if (flags)
551 diff_flags_or(&rev.diffopt.flags, flags);
552 rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
553 run_diff_index(&rev, 1);
554 object_array_clear(&rev.pending);
555 return (rev.diffopt.flags.HAS_CHANGES != 0);
556 }