Merge branch 'jc/maint-diff-q-filter' into maint
[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
15 /*
16 * diff-files
17 */
18
19 /*
20 * Has the work tree entity been removed?
21 *
22 * Return 1 if it was removed from the work tree, 0 if an entity to be
23 * compared with the cache entry ce still exists (the latter includes
24 * the case where a directory that is not a submodule repository
25 * exists for ce that is a submodule -- it is a submodule that is not
26 * checked out). Return negative for an error.
27 */
28 static int check_removed(const struct cache_entry *ce, struct stat *st)
29 {
30 if (lstat(ce->name, st) < 0) {
31 if (errno != ENOENT && errno != ENOTDIR)
32 return -1;
33 return 1;
34 }
35 if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
36 return 1;
37 if (S_ISDIR(st->st_mode)) {
38 unsigned char sub[20];
39
40 /*
41 * If ce is already a gitlink, we can have a plain
42 * directory (i.e. the submodule is not checked out),
43 * or a checked out submodule. Either case this is not
44 * a case where something was removed from the work tree,
45 * so we will return 0.
46 *
47 * Otherwise, if the directory is not a submodule
48 * repository, that means ce which was a blob turned into
49 * a directory --- the blob was removed!
50 */
51 if (!S_ISGITLINK(ce->ce_mode) &&
52 resolve_gitlink_ref(ce->name, "HEAD", sub))
53 return 1;
54 }
55 return 0;
56 }
57
58 /*
59 * Has a file changed or has a submodule new commits or a dirty work tree?
60 *
61 * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
62 * option is set, the caller does not only want to know if a submodule is
63 * modified at all but wants to know all the conditions that are met (new
64 * commits, untracked content and/or modified content).
65 */
66 static int match_stat_with_submodule(struct diff_options *diffopt,
67 struct cache_entry *ce, struct stat *st,
68 unsigned ce_option, unsigned *dirty_submodule)
69 {
70 int changed = ce_match_stat(ce, st, ce_option);
71 if (S_ISGITLINK(ce->ce_mode)) {
72 unsigned orig_flags = diffopt->flags;
73 if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
74 set_diffopt_flags_from_submodule_config(diffopt, ce->name);
75 if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
76 changed = 0;
77 else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
78 && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
79 *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
80 diffopt->flags = orig_flags;
81 }
82 return changed;
83 }
84
85 int run_diff_files(struct rev_info *revs, unsigned int option)
86 {
87 int entries, i;
88 int diff_unmerged_stage = revs->max_count;
89 int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
90 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
91 ? CE_MATCH_RACY_IS_DIRTY : 0);
92
93 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
94
95 if (diff_unmerged_stage < 0)
96 diff_unmerged_stage = 2;
97 entries = active_nr;
98 for (i = 0; i < entries; i++) {
99 struct stat st;
100 unsigned int oldmode, newmode;
101 struct cache_entry *ce = active_cache[i];
102 int changed;
103 unsigned dirty_submodule = 0;
104
105 if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
106 !revs->diffopt.filter &&
107 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
108 break;
109
110 if (!ce_path_match(ce, revs->prune_data))
111 continue;
112
113 if (ce_stage(ce)) {
114 struct combine_diff_path *dpath;
115 int num_compare_stages = 0;
116 size_t path_len;
117
118 path_len = ce_namelen(ce);
119
120 dpath = xmalloc(combine_diff_path_size(5, path_len));
121 dpath->path = (char *) &(dpath->parent[5]);
122
123 dpath->next = NULL;
124 dpath->len = path_len;
125 memcpy(dpath->path, ce->name, path_len);
126 dpath->path[path_len] = '\0';
127 hashclr(dpath->sha1);
128 memset(&(dpath->parent[0]), 0,
129 sizeof(struct combine_diff_parent)*5);
130
131 changed = check_removed(ce, &st);
132 if (!changed)
133 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
134 else {
135 if (changed < 0) {
136 perror(ce->name);
137 continue;
138 }
139 if (silent_on_removed)
140 continue;
141 }
142
143 while (i < entries) {
144 struct cache_entry *nce = active_cache[i];
145 int stage;
146
147 if (strcmp(ce->name, nce->name))
148 break;
149
150 /* Stage #2 (ours) is the first parent,
151 * stage #3 (theirs) is the second.
152 */
153 stage = ce_stage(nce);
154 if (2 <= stage) {
155 int mode = nce->ce_mode;
156 num_compare_stages++;
157 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
158 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
159 dpath->parent[stage-2].status =
160 DIFF_STATUS_MODIFIED;
161 }
162
163 /* diff against the proper unmerged stage */
164 if (stage == diff_unmerged_stage)
165 ce = nce;
166 i++;
167 }
168 /*
169 * Compensate for loop update
170 */
171 i--;
172
173 if (revs->combine_merges && num_compare_stages == 2) {
174 show_combined_diff(dpath, 2,
175 revs->dense_combined_merges,
176 revs);
177 free(dpath);
178 continue;
179 }
180 free(dpath);
181 dpath = NULL;
182
183 /*
184 * Show the diff for the 'ce' if we found the one
185 * from the desired stage.
186 */
187 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
188 if (ce_stage(ce) != diff_unmerged_stage)
189 continue;
190 }
191
192 if (ce_uptodate(ce) || ce_skip_worktree(ce))
193 continue;
194
195 /* If CE_VALID is set, don't look at workdir for file removal */
196 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
197 if (changed) {
198 if (changed < 0) {
199 perror(ce->name);
200 continue;
201 }
202 if (silent_on_removed)
203 continue;
204 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
205 ce->sha1, ce->name, 0);
206 continue;
207 }
208 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
209 ce_option, &dirty_submodule);
210 if (!changed && !dirty_submodule) {
211 ce_mark_uptodate(ce);
212 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
213 continue;
214 }
215 oldmode = ce->ce_mode;
216 newmode = ce_mode_from_stat(ce, st.st_mode);
217 diff_change(&revs->diffopt, oldmode, newmode,
218 ce->sha1, (changed ? null_sha1 : ce->sha1),
219 ce->name, 0, dirty_submodule);
220
221 }
222 diffcore_std(&revs->diffopt);
223 diff_flush(&revs->diffopt);
224 return 0;
225 }
226
227 /*
228 * diff-index
229 */
230
231 /* A file entry went away or appeared */
232 static void diff_index_show_file(struct rev_info *revs,
233 const char *prefix,
234 struct cache_entry *ce,
235 const unsigned char *sha1, unsigned int mode,
236 unsigned dirty_submodule)
237 {
238 diff_addremove(&revs->diffopt, prefix[0], mode,
239 sha1, ce->name, dirty_submodule);
240 }
241
242 static int get_stat_data(struct cache_entry *ce,
243 const unsigned char **sha1p,
244 unsigned int *modep,
245 int cached, int match_missing,
246 unsigned *dirty_submodule, struct diff_options *diffopt)
247 {
248 const unsigned char *sha1 = ce->sha1;
249 unsigned int mode = ce->ce_mode;
250
251 if (!cached && !ce_uptodate(ce)) {
252 int changed;
253 struct stat st;
254 changed = check_removed(ce, &st);
255 if (changed < 0)
256 return -1;
257 else if (changed) {
258 if (match_missing) {
259 *sha1p = sha1;
260 *modep = mode;
261 return 0;
262 }
263 return -1;
264 }
265 changed = match_stat_with_submodule(diffopt, ce, &st,
266 0, dirty_submodule);
267 if (changed) {
268 mode = ce_mode_from_stat(ce, st.st_mode);
269 sha1 = null_sha1;
270 }
271 }
272
273 *sha1p = sha1;
274 *modep = mode;
275 return 0;
276 }
277
278 static void show_new_file(struct rev_info *revs,
279 struct cache_entry *new,
280 int cached, int match_missing)
281 {
282 const unsigned char *sha1;
283 unsigned int mode;
284 unsigned dirty_submodule = 0;
285
286 /*
287 * New file in the index: it might actually be different in
288 * the working copy.
289 */
290 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
291 &dirty_submodule, &revs->diffopt) < 0)
292 return;
293
294 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
295 }
296
297 static int show_modified(struct rev_info *revs,
298 struct cache_entry *old,
299 struct cache_entry *new,
300 int report_missing,
301 int cached, int match_missing)
302 {
303 unsigned int mode, oldmode;
304 const unsigned char *sha1;
305 unsigned dirty_submodule = 0;
306
307 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
308 &dirty_submodule, &revs->diffopt) < 0) {
309 if (report_missing)
310 diff_index_show_file(revs, "-", old,
311 old->sha1, old->ce_mode, 0);
312 return -1;
313 }
314
315 if (revs->combine_merges && !cached &&
316 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
317 struct combine_diff_path *p;
318 int pathlen = ce_namelen(new);
319
320 p = xmalloc(combine_diff_path_size(2, pathlen));
321 p->path = (char *) &p->parent[2];
322 p->next = NULL;
323 p->len = pathlen;
324 memcpy(p->path, new->name, pathlen);
325 p->path[pathlen] = 0;
326 p->mode = mode;
327 hashclr(p->sha1);
328 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
329 p->parent[0].status = DIFF_STATUS_MODIFIED;
330 p->parent[0].mode = new->ce_mode;
331 hashcpy(p->parent[0].sha1, new->sha1);
332 p->parent[1].status = DIFF_STATUS_MODIFIED;
333 p->parent[1].mode = old->ce_mode;
334 hashcpy(p->parent[1].sha1, old->sha1);
335 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
336 free(p);
337 return 0;
338 }
339
340 oldmode = old->ce_mode;
341 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
342 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
343 return 0;
344
345 diff_change(&revs->diffopt, oldmode, mode,
346 old->sha1, sha1, old->name, 0, dirty_submodule);
347 return 0;
348 }
349
350 /*
351 * This gets a mix of an existing index and a tree, one pathname entry
352 * at a time. The index entry may be a single stage-0 one, but it could
353 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
354 * give you the position and number of entries in the index).
355 */
356 static void do_oneway_diff(struct unpack_trees_options *o,
357 struct cache_entry *idx,
358 struct cache_entry *tree)
359 {
360 struct rev_info *revs = o->unpack_data;
361 int match_missing, cached;
362
363 /* if the entry is not checked out, don't examine work tree */
364 cached = o->index_only ||
365 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
366 /*
367 * Backward compatibility wart - "diff-index -m" does
368 * not mean "do not ignore merges", but "match_missing".
369 *
370 * But with the revision flag parsing, that's found in
371 * "!revs->ignore_merges".
372 */
373 match_missing = !revs->ignore_merges;
374
375 if (cached && idx && ce_stage(idx)) {
376 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
377 idx->sha1);
378 return;
379 }
380
381 /*
382 * Something added to the tree?
383 */
384 if (!tree) {
385 show_new_file(revs, idx, cached, match_missing);
386 return;
387 }
388
389 /*
390 * Something removed from the tree?
391 */
392 if (!idx) {
393 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
394 return;
395 }
396
397 /* Show difference between old and new */
398 show_modified(revs, tree, idx, 1, cached, match_missing);
399 }
400
401 /*
402 * The unpack_trees() interface is designed for merging, so
403 * the different source entries are designed primarily for
404 * the source trees, with the old index being really mainly
405 * used for being replaced by the result.
406 *
407 * For diffing, the index is more important, and we only have a
408 * single tree.
409 *
410 * We're supposed to advance o->pos to skip what we have already processed.
411 *
412 * This wrapper makes it all more readable, and takes care of all
413 * the fairly complex unpack_trees() semantic requirements, including
414 * the skipping, the path matching, the type conflict cases etc.
415 */
416 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
417 {
418 struct cache_entry *idx = src[0];
419 struct cache_entry *tree = src[1];
420 struct rev_info *revs = o->unpack_data;
421
422 /*
423 * Unpack-trees generates a DF/conflict entry if
424 * there was a directory in the index and a tree
425 * in the tree. From a diff standpoint, that's a
426 * delete of the tree and a create of the file.
427 */
428 if (tree == o->df_conflict_entry)
429 tree = NULL;
430
431 if (ce_path_match(idx ? idx : tree, revs->prune_data))
432 do_oneway_diff(o, idx, tree);
433
434 return 0;
435 }
436
437 int run_diff_index(struct rev_info *revs, int cached)
438 {
439 struct object *ent;
440 struct tree *tree;
441 const char *tree_name;
442 struct unpack_trees_options opts;
443 struct tree_desc t;
444
445 ent = revs->pending.objects[0].item;
446 tree_name = revs->pending.objects[0].name;
447 tree = parse_tree_indirect(ent->sha1);
448 if (!tree)
449 return error("bad tree object %s", tree_name);
450
451 memset(&opts, 0, sizeof(opts));
452 opts.head_idx = 1;
453 opts.index_only = cached;
454 opts.diff_index_cached = (cached &&
455 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
456 opts.merge = 1;
457 opts.fn = oneway_diff;
458 opts.unpack_data = revs;
459 opts.src_index = &the_index;
460 opts.dst_index = NULL;
461
462 init_tree_desc(&t, tree->buffer, tree->size);
463 if (unpack_trees(1, &t, &opts))
464 exit(128);
465
466 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
467 diffcore_fix_diff_index(&revs->diffopt);
468 diffcore_std(&revs->diffopt);
469 diff_flush(&revs->diffopt);
470 return 0;
471 }
472
473 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
474 {
475 struct tree *tree;
476 struct rev_info revs;
477 int i;
478 struct cache_entry **dst;
479 struct cache_entry *last = NULL;
480 struct unpack_trees_options opts;
481 struct tree_desc t;
482
483 /*
484 * This is used by git-blame to run diff-cache internally;
485 * it potentially needs to repeatedly run this, so we will
486 * start by removing the higher order entries the last round
487 * left behind.
488 */
489 dst = active_cache;
490 for (i = 0; i < active_nr; i++) {
491 struct cache_entry *ce = active_cache[i];
492 if (ce_stage(ce)) {
493 if (last && !strcmp(ce->name, last->name))
494 continue;
495 cache_tree_invalidate_path(active_cache_tree,
496 ce->name);
497 last = ce;
498 ce->ce_flags |= CE_REMOVE;
499 }
500 *dst++ = ce;
501 }
502 active_nr = dst - active_cache;
503
504 init_revisions(&revs, NULL);
505 revs.prune_data = opt->paths;
506 tree = parse_tree_indirect(tree_sha1);
507 if (!tree)
508 die("bad tree object %s", sha1_to_hex(tree_sha1));
509
510 memset(&opts, 0, sizeof(opts));
511 opts.head_idx = 1;
512 opts.index_only = 1;
513 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
514 opts.merge = 1;
515 opts.fn = oneway_diff;
516 opts.unpack_data = &revs;
517 opts.src_index = &the_index;
518 opts.dst_index = &the_index;
519
520 init_tree_desc(&t, tree->buffer, tree->size);
521 if (unpack_trees(1, &t, &opts))
522 exit(128);
523 return 0;
524 }
525
526 int index_differs_from(const char *def, int diff_flags)
527 {
528 struct rev_info rev;
529 struct setup_revision_opt opt;
530
531 init_revisions(&rev, NULL);
532 memset(&opt, 0, sizeof(opt));
533 opt.def = def;
534 setup_revisions(0, NULL, &rev, &opt);
535 DIFF_OPT_SET(&rev.diffopt, QUICK);
536 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
537 rev.diffopt.flags |= diff_flags;
538 run_diff_index(&rev, 1);
539 if (rev.pending.alloc)
540 free(rev.pending.objects);
541 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
542 }