Merge branch 'ag/userdiff-go-funcname'
[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 #include "fsmonitor.h"
16
17 /*
18 * diff-files
19 */
20
21 /*
22 * Has the work tree entity been removed?
23 *
24 * Return 1 if it was removed from the work tree, 0 if an entity to be
25 * compared with the cache entry ce still exists (the latter includes
26 * the case where a directory that is not a submodule repository
27 * exists for ce that is a submodule -- it is a submodule that is not
28 * checked out). Return negative for an error.
29 */
30 static int check_removed(const struct cache_entry *ce, struct stat *st)
31 {
32 if (lstat(ce->name, st) < 0) {
33 if (!is_missing_file_error(errno))
34 return -1;
35 return 1;
36 }
37 if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
38 return 1;
39 if (S_ISDIR(st->st_mode)) {
40 struct object_id sub;
41
42 /*
43 * If ce is already a gitlink, we can have a plain
44 * directory (i.e. the submodule is not checked out),
45 * or a checked out submodule. Either case this is not
46 * a case where something was removed from the work tree,
47 * so we will return 0.
48 *
49 * Otherwise, if the directory is not a submodule
50 * repository, that means ce which was a blob turned into
51 * a directory --- the blob was removed!
52 */
53 if (!S_ISGITLINK(ce->ce_mode) &&
54 resolve_gitlink_ref(ce->name, "HEAD", &sub))
55 return 1;
56 }
57 return 0;
58 }
59
60 /*
61 * Has a file changed or has a submodule new commits or a dirty work tree?
62 *
63 * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
64 * option is set, the caller does not only want to know if a submodule is
65 * modified at all but wants to know all the conditions that are met (new
66 * commits, untracked content and/or modified content).
67 */
68 static int match_stat_with_submodule(struct diff_options *diffopt,
69 const struct cache_entry *ce,
70 struct stat *st, unsigned ce_option,
71 unsigned *dirty_submodule)
72 {
73 int changed = ce_match_stat(ce, st, ce_option);
74 if (S_ISGITLINK(ce->ce_mode)) {
75 struct diff_flags orig_flags = diffopt->flags;
76 if (!diffopt->flags.override_submodule_config)
77 set_diffopt_flags_from_submodule_config(diffopt, ce->name);
78 if (diffopt->flags.ignore_submodules)
79 changed = 0;
80 else if (!diffopt->flags.ignore_dirty_submodules &&
81 (!changed || diffopt->flags.dirty_submodules))
82 *dirty_submodule = is_submodule_modified(ce->name,
83 diffopt->flags.ignore_untracked_in_submodules);
84 diffopt->flags = orig_flags;
85 }
86 return changed;
87 }
88
89 int run_diff_files(struct rev_info *revs, unsigned int option)
90 {
91 int entries, i;
92 int diff_unmerged_stage = revs->max_count;
93 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
94 ? CE_MATCH_RACY_IS_DIRTY : 0);
95 uint64_t start = getnanotime();
96
97 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
98
99 if (diff_unmerged_stage < 0)
100 diff_unmerged_stage = 2;
101 entries = active_nr;
102 for (i = 0; i < entries; i++) {
103 unsigned int oldmode, newmode;
104 struct cache_entry *ce = active_cache[i];
105 int changed;
106 unsigned dirty_submodule = 0;
107 const struct object_id *old_oid, *new_oid;
108
109 if (diff_can_quit_early(&revs->diffopt))
110 break;
111
112 if (!ce_path_match(ce, &revs->prune_data, NULL))
113 continue;
114
115 if (ce_stage(ce)) {
116 struct combine_diff_path *dpath;
117 struct diff_filepair *pair;
118 unsigned int wt_mode = 0;
119 int num_compare_stages = 0;
120 size_t path_len;
121 struct stat st;
122
123 path_len = ce_namelen(ce);
124
125 dpath = xmalloc(combine_diff_path_size(5, path_len));
126 dpath->path = (char *) &(dpath->parent[5]);
127
128 dpath->next = NULL;
129 memcpy(dpath->path, ce->name, path_len);
130 dpath->path[path_len] = '\0';
131 oidclr(&dpath->oid);
132 memset(&(dpath->parent[0]), 0,
133 sizeof(struct combine_diff_parent)*5);
134
135 changed = check_removed(ce, &st);
136 if (!changed)
137 wt_mode = ce_mode_from_stat(ce, st.st_mode);
138 else {
139 if (changed < 0) {
140 perror(ce->name);
141 continue;
142 }
143 wt_mode = 0;
144 }
145 dpath->mode = wt_mode;
146
147 while (i < entries) {
148 struct cache_entry *nce = active_cache[i];
149 int stage;
150
151 if (strcmp(ce->name, nce->name))
152 break;
153
154 /* Stage #2 (ours) is the first parent,
155 * stage #3 (theirs) is the second.
156 */
157 stage = ce_stage(nce);
158 if (2 <= stage) {
159 int mode = nce->ce_mode;
160 num_compare_stages++;
161 oidcpy(&dpath->parent[stage - 2].oid,
162 &nce->oid);
163 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
164 dpath->parent[stage-2].status =
165 DIFF_STATUS_MODIFIED;
166 }
167
168 /* diff against the proper unmerged stage */
169 if (stage == diff_unmerged_stage)
170 ce = nce;
171 i++;
172 }
173 /*
174 * Compensate for loop update
175 */
176 i--;
177
178 if (revs->combine_merges && num_compare_stages == 2) {
179 show_combined_diff(dpath, 2,
180 revs->dense_combined_merges,
181 revs);
182 free(dpath);
183 continue;
184 }
185 FREE_AND_NULL(dpath);
186
187 /*
188 * Show the diff for the 'ce' if we found the one
189 * from the desired stage.
190 */
191 pair = diff_unmerge(&revs->diffopt, ce->name);
192 if (wt_mode)
193 pair->two->mode = wt_mode;
194 if (ce_stage(ce) != diff_unmerged_stage)
195 continue;
196 }
197
198 if (ce_uptodate(ce) || ce_skip_worktree(ce))
199 continue;
200
201 /* If CE_VALID is set, don't look at workdir for file removal */
202 if (ce->ce_flags & CE_VALID) {
203 changed = 0;
204 newmode = ce->ce_mode;
205 } else {
206 struct stat st;
207
208 changed = check_removed(ce, &st);
209 if (changed) {
210 if (changed < 0) {
211 perror(ce->name);
212 continue;
213 }
214 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
215 &ce->oid,
216 !is_null_oid(&ce->oid),
217 ce->name, 0);
218 continue;
219 } else if (revs->diffopt.ita_invisible_in_index &&
220 ce_intent_to_add(ce)) {
221 diff_addremove(&revs->diffopt, '+', ce->ce_mode,
222 the_hash_algo->empty_tree, 0,
223 ce->name, 0);
224 continue;
225 }
226
227 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
228 ce_option, &dirty_submodule);
229 newmode = ce_mode_from_stat(ce, st.st_mode);
230 }
231
232 if (!changed && !dirty_submodule) {
233 ce_mark_uptodate(ce);
234 mark_fsmonitor_valid(ce);
235 if (!revs->diffopt.flags.find_copies_harder)
236 continue;
237 }
238 oldmode = ce->ce_mode;
239 old_oid = &ce->oid;
240 new_oid = changed ? &null_oid : &ce->oid;
241 diff_change(&revs->diffopt, oldmode, newmode,
242 old_oid, new_oid,
243 !is_null_oid(old_oid),
244 !is_null_oid(new_oid),
245 ce->name, 0, dirty_submodule);
246
247 }
248 diffcore_std(&revs->diffopt);
249 diff_flush(&revs->diffopt);
250 trace_performance_since(start, "diff-files");
251 return 0;
252 }
253
254 /*
255 * diff-index
256 */
257
258 /* A file entry went away or appeared */
259 static void diff_index_show_file(struct rev_info *revs,
260 const char *prefix,
261 const struct cache_entry *ce,
262 const struct object_id *oid, int oid_valid,
263 unsigned int mode,
264 unsigned dirty_submodule)
265 {
266 diff_addremove(&revs->diffopt, prefix[0], mode,
267 oid, oid_valid, ce->name, dirty_submodule);
268 }
269
270 static int get_stat_data(const struct cache_entry *ce,
271 const struct object_id **oidp,
272 unsigned int *modep,
273 int cached, int match_missing,
274 unsigned *dirty_submodule, struct diff_options *diffopt)
275 {
276 const struct object_id *oid = &ce->oid;
277 unsigned int mode = ce->ce_mode;
278
279 if (!cached && !ce_uptodate(ce)) {
280 int changed;
281 struct stat st;
282 changed = check_removed(ce, &st);
283 if (changed < 0)
284 return -1;
285 else if (changed) {
286 if (match_missing) {
287 *oidp = oid;
288 *modep = mode;
289 return 0;
290 }
291 return -1;
292 }
293 changed = match_stat_with_submodule(diffopt, ce, &st,
294 0, dirty_submodule);
295 if (changed) {
296 mode = ce_mode_from_stat(ce, st.st_mode);
297 oid = &null_oid;
298 }
299 }
300
301 *oidp = oid;
302 *modep = mode;
303 return 0;
304 }
305
306 static void show_new_file(struct rev_info *revs,
307 const struct cache_entry *new_file,
308 int cached, int match_missing)
309 {
310 const struct object_id *oid;
311 unsigned int mode;
312 unsigned dirty_submodule = 0;
313
314 /*
315 * New file in the index: it might actually be different in
316 * the working tree.
317 */
318 if (get_stat_data(new_file, &oid, &mode, cached, match_missing,
319 &dirty_submodule, &revs->diffopt) < 0)
320 return;
321
322 diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
323 }
324
325 static int show_modified(struct rev_info *revs,
326 const struct cache_entry *old_entry,
327 const struct cache_entry *new_entry,
328 int report_missing,
329 int cached, int match_missing)
330 {
331 unsigned int mode, oldmode;
332 const struct object_id *oid;
333 unsigned dirty_submodule = 0;
334
335 if (get_stat_data(new_entry, &oid, &mode, cached, match_missing,
336 &dirty_submodule, &revs->diffopt) < 0) {
337 if (report_missing)
338 diff_index_show_file(revs, "-", old_entry,
339 &old_entry->oid, 1, old_entry->ce_mode,
340 0);
341 return -1;
342 }
343
344 if (revs->combine_merges && !cached &&
345 (oidcmp(oid, &old_entry->oid) || oidcmp(&old_entry->oid, &new_entry->oid))) {
346 struct combine_diff_path *p;
347 int pathlen = ce_namelen(new_entry);
348
349 p = xmalloc(combine_diff_path_size(2, pathlen));
350 p->path = (char *) &p->parent[2];
351 p->next = NULL;
352 memcpy(p->path, new_entry->name, pathlen);
353 p->path[pathlen] = 0;
354 p->mode = mode;
355 oidclr(&p->oid);
356 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
357 p->parent[0].status = DIFF_STATUS_MODIFIED;
358 p->parent[0].mode = new_entry->ce_mode;
359 oidcpy(&p->parent[0].oid, &new_entry->oid);
360 p->parent[1].status = DIFF_STATUS_MODIFIED;
361 p->parent[1].mode = old_entry->ce_mode;
362 oidcpy(&p->parent[1].oid, &old_entry->oid);
363 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
364 free(p);
365 return 0;
366 }
367
368 oldmode = old_entry->ce_mode;
369 if (mode == oldmode && !oidcmp(oid, &old_entry->oid) && !dirty_submodule &&
370 !revs->diffopt.flags.find_copies_harder)
371 return 0;
372
373 diff_change(&revs->diffopt, oldmode, mode,
374 &old_entry->oid, oid, 1, !is_null_oid(oid),
375 old_entry->name, 0, dirty_submodule);
376 return 0;
377 }
378
379 /*
380 * This gets a mix of an existing index and a tree, one pathname entry
381 * at a time. The index entry may be a single stage-0 one, but it could
382 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
383 * give you the position and number of entries in the index).
384 */
385 static void do_oneway_diff(struct unpack_trees_options *o,
386 const struct cache_entry *idx,
387 const struct cache_entry *tree)
388 {
389 struct rev_info *revs = o->unpack_data;
390 int match_missing, cached;
391
392 /* i-t-a entries do not actually exist in the index */
393 if (revs->diffopt.ita_invisible_in_index &&
394 idx && ce_intent_to_add(idx)) {
395 idx = NULL;
396 if (!tree)
397 return; /* nothing to diff.. */
398 }
399
400 /* if the entry is not checked out, don't examine work tree */
401 cached = o->index_only ||
402 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
403 /*
404 * Backward compatibility wart - "diff-index -m" does
405 * not mean "do not ignore merges", but "match_missing".
406 *
407 * But with the revision flag parsing, that's found in
408 * "!revs->ignore_merges".
409 */
410 match_missing = !revs->ignore_merges;
411
412 if (cached && idx && ce_stage(idx)) {
413 struct diff_filepair *pair;
414 pair = diff_unmerge(&revs->diffopt, idx->name);
415 if (tree)
416 fill_filespec(pair->one, &tree->oid, 1,
417 tree->ce_mode);
418 return;
419 }
420
421 /*
422 * Something added to the tree?
423 */
424 if (!tree) {
425 show_new_file(revs, idx, cached, match_missing);
426 return;
427 }
428
429 /*
430 * Something removed from the tree?
431 */
432 if (!idx) {
433 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
434 tree->ce_mode, 0);
435 return;
436 }
437
438 /* Show difference between old and new */
439 show_modified(revs, tree, idx, 1, cached, match_missing);
440 }
441
442 /*
443 * The unpack_trees() interface is designed for merging, so
444 * the different source entries are designed primarily for
445 * the source trees, with the old index being really mainly
446 * used for being replaced by the result.
447 *
448 * For diffing, the index is more important, and we only have a
449 * single tree.
450 *
451 * We're supposed to advance o->pos to skip what we have already processed.
452 *
453 * This wrapper makes it all more readable, and takes care of all
454 * the fairly complex unpack_trees() semantic requirements, including
455 * the skipping, the path matching, the type conflict cases etc.
456 */
457 static int oneway_diff(const struct cache_entry * const *src,
458 struct unpack_trees_options *o)
459 {
460 const struct cache_entry *idx = src[0];
461 const struct cache_entry *tree = src[1];
462 struct rev_info *revs = o->unpack_data;
463
464 /*
465 * Unpack-trees generates a DF/conflict entry if
466 * there was a directory in the index and a tree
467 * in the tree. From a diff standpoint, that's a
468 * delete of the tree and a create of the file.
469 */
470 if (tree == o->df_conflict_entry)
471 tree = NULL;
472
473 if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
474 do_oneway_diff(o, idx, tree);
475 if (diff_can_quit_early(&revs->diffopt)) {
476 o->exiting_early = 1;
477 return -1;
478 }
479 }
480
481 return 0;
482 }
483
484 static int diff_cache(struct rev_info *revs,
485 const struct object_id *tree_oid,
486 const char *tree_name,
487 int cached)
488 {
489 struct tree *tree;
490 struct tree_desc t;
491 struct unpack_trees_options opts;
492
493 tree = parse_tree_indirect(tree_oid);
494 if (!tree)
495 return error("bad tree object %s",
496 tree_name ? tree_name : oid_to_hex(tree_oid));
497 memset(&opts, 0, sizeof(opts));
498 opts.head_idx = 1;
499 opts.index_only = cached;
500 opts.diff_index_cached = (cached &&
501 !revs->diffopt.flags.find_copies_harder);
502 opts.merge = 1;
503 opts.fn = oneway_diff;
504 opts.unpack_data = revs;
505 opts.src_index = &the_index;
506 opts.dst_index = NULL;
507 opts.pathspec = &revs->diffopt.pathspec;
508 opts.pathspec->recursive = 1;
509
510 init_tree_desc(&t, tree->buffer, tree->size);
511 return unpack_trees(1, &t, &opts);
512 }
513
514 int run_diff_index(struct rev_info *revs, int cached)
515 {
516 struct object_array_entry *ent;
517 uint64_t start = getnanotime();
518
519 ent = revs->pending.objects;
520 if (diff_cache(revs, &ent->item->oid, ent->name, cached))
521 exit(128);
522
523 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
524 diffcore_fix_diff_index(&revs->diffopt);
525 diffcore_std(&revs->diffopt);
526 diff_flush(&revs->diffopt);
527 trace_performance_since(start, "diff-index");
528 return 0;
529 }
530
531 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
532 {
533 struct rev_info revs;
534
535 init_revisions(&revs, NULL);
536 copy_pathspec(&revs.prune_data, &opt->pathspec);
537 revs.diffopt = *opt;
538
539 if (diff_cache(&revs, tree_oid, NULL, 1))
540 exit(128);
541 return 0;
542 }
543
544 int index_differs_from(const char *def, const struct diff_flags *flags,
545 int ita_invisible_in_index)
546 {
547 struct rev_info rev;
548 struct setup_revision_opt opt;
549
550 init_revisions(&rev, NULL);
551 memset(&opt, 0, sizeof(opt));
552 opt.def = def;
553 setup_revisions(0, NULL, &rev, &opt);
554 rev.diffopt.flags.quick = 1;
555 rev.diffopt.flags.exit_with_status = 1;
556 if (flags)
557 diff_flags_or(&rev.diffopt.flags, flags);
558 rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
559 run_diff_index(&rev, 1);
560 object_array_clear(&rev.pending);
561 return (rev.diffopt.flags.has_changes != 0);
562 }