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/*
16 * diff-files
17 */
18/*
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 */
28static 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 /*
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/*
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 */
66static 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}
84int 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 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
94 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 if (diff_can_quit_early(&revs->diffopt))
106 break;
107 if (!ce_path_match(ce, &revs->prune_data))
109 continue;
110 if (ce_stage(ce)) {
112 struct combine_diff_path *dpath;
113 struct diff_filepair *pair;
114 unsigned int wt_mode = 0;
115 int num_compare_stages = 0;
116 size_t path_len;
117 path_len = ce_namelen(ce);
119 dpath = xmalloc(combine_diff_path_size(5, path_len));
121 dpath->path = (char *) &(dpath->parent[5]);
122 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 changed = check_removed(ce, &st);
132 if (!changed)
133 wt_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 wt_mode = 0;
142 }
143 dpath->mode = wt_mode;
144 while (i < entries) {
146 struct cache_entry *nce = active_cache[i];
147 int stage;
148 if (strcmp(ce->name, nce->name))
150 break;
151 /* 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 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
160 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
161 dpath->parent[stage-2].status =
162 DIFF_STATUS_MODIFIED;
163 }
164 /* diff against the proper unmerged stage */
166 if (stage == diff_unmerged_stage)
167 ce = nce;
168 i++;
169 }
170 /*
171 * Compensate for loop update
172 */
173 i--;
174 if (revs->combine_merges && num_compare_stages == 2) {
176 show_combined_diff(dpath, 2,
177 revs->dense_combined_merges,
178 revs);
179 free(dpath);
180 continue;
181 }
182 free(dpath);
183 dpath = NULL;
184 /*
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 if (ce_uptodate(ce) || ce_skip_worktree(ce))
197 continue;
198 /* If CE_VALID is set, don't look at workdir for file removal */
200 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
201 if (changed) {
202 if (changed < 0) {
203 perror(ce->name);
204 continue;
205 }
206 if (silent_on_removed)
207 continue;
208 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
209 ce->sha1, ce->name, 0);
210 continue;
211 }
212 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
213 ce_option, &dirty_submodule);
214 if (!changed && !dirty_submodule) {
215 ce_mark_uptodate(ce);
216 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
217 continue;
218 }
219 oldmode = ce->ce_mode;
220 newmode = ce_mode_from_stat(ce, st.st_mode);
221 diff_change(&revs->diffopt, oldmode, newmode,
222 ce->sha1, (changed ? null_sha1 : ce->sha1),
223 ce->name, 0, dirty_submodule);
224 }
226 diffcore_std(&revs->diffopt);
227 diff_flush(&revs->diffopt);
228 return 0;
229}
230/*
232 * diff-index
233 */
234/* A file entry went away or appeared */
236static void diff_index_show_file(struct rev_info *revs,
237 const char *prefix,
238 struct cache_entry *ce,
239 const unsigned char *sha1, unsigned int mode,
240 unsigned dirty_submodule)
241{
242 diff_addremove(&revs->diffopt, prefix[0], mode,
243 sha1, ce->name, dirty_submodule);
244}
245static int get_stat_data(struct cache_entry *ce,
247 const unsigned char **sha1p,
248 unsigned int *modep,
249 int cached, int match_missing,
250 unsigned *dirty_submodule, struct diff_options *diffopt)
251{
252 const unsigned char *sha1 = ce->sha1;
253 unsigned int mode = ce->ce_mode;
254 if (!cached && !ce_uptodate(ce)) {
256 int changed;
257 struct stat st;
258 changed = check_removed(ce, &st);
259 if (changed < 0)
260 return -1;
261 else if (changed) {
262 if (match_missing) {
263 *sha1p = sha1;
264 *modep = mode;
265 return 0;
266 }
267 return -1;
268 }
269 changed = match_stat_with_submodule(diffopt, ce, &st,
270 0, dirty_submodule);
271 if (changed) {
272 mode = ce_mode_from_stat(ce, st.st_mode);
273 sha1 = null_sha1;
274 }
275 }
276 *sha1p = sha1;
278 *modep = mode;
279 return 0;
280}
281static void show_new_file(struct rev_info *revs,
283 struct cache_entry *new,
284 int cached, int match_missing)
285{
286 const unsigned char *sha1;
287 unsigned int mode;
288 unsigned dirty_submodule = 0;
289 /*
291 * New file in the index: it might actually be different in
292 * the working copy.
293 */
294 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
295 &dirty_submodule, &revs->diffopt) < 0)
296 return;
297 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
299}
300static int show_modified(struct rev_info *revs,
302 struct cache_entry *old,
303 struct cache_entry *new,
304 int report_missing,
305 int cached, int match_missing)
306{
307 unsigned int mode, oldmode;
308 const unsigned char *sha1;
309 unsigned dirty_submodule = 0;
310 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
312 &dirty_submodule, &revs->diffopt) < 0) {
313 if (report_missing)
314 diff_index_show_file(revs, "-", old,
315 old->sha1, old->ce_mode, 0);
316 return -1;
317 }
318 if (revs->combine_merges && !cached &&
320 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
321 struct combine_diff_path *p;
322 int pathlen = ce_namelen(new);
323 p = xmalloc(combine_diff_path_size(2, pathlen));
325 p->path = (char *) &p->parent[2];
326 p->next = NULL;
327 p->len = pathlen;
328 memcpy(p->path, new->name, pathlen);
329 p->path[pathlen] = 0;
330 p->mode = mode;
331 hashclr(p->sha1);
332 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
333 p->parent[0].status = DIFF_STATUS_MODIFIED;
334 p->parent[0].mode = new->ce_mode;
335 hashcpy(p->parent[0].sha1, new->sha1);
336 p->parent[1].status = DIFF_STATUS_MODIFIED;
337 p->parent[1].mode = old->ce_mode;
338 hashcpy(p->parent[1].sha1, old->sha1);
339 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
340 free(p);
341 return 0;
342 }
343 oldmode = old->ce_mode;
345 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
346 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
347 return 0;
348 diff_change(&revs->diffopt, oldmode, mode,
350 old->sha1, sha1, old->name, 0, dirty_submodule);
351 return 0;
352}
353/*
355 * This gets a mix of an existing index and a tree, one pathname entry
356 * at a time. The index entry may be a single stage-0 one, but it could
357 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
358 * give you the position and number of entries in the index).
359 */
360static void do_oneway_diff(struct unpack_trees_options *o,
361 struct cache_entry *idx,
362 struct cache_entry *tree)
363{
364 struct rev_info *revs = o->unpack_data;
365 int match_missing, cached;
366 /* if the entry is not checked out, don't examine work tree */
368 cached = o->index_only ||
369 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
370 /*
371 * Backward compatibility wart - "diff-index -m" does
372 * not mean "do not ignore merges", but "match_missing".
373 *
374 * But with the revision flag parsing, that's found in
375 * "!revs->ignore_merges".
376 */
377 match_missing = !revs->ignore_merges;
378 if (cached && idx && ce_stage(idx)) {
380 struct diff_filepair *pair;
381 pair = diff_unmerge(&revs->diffopt, idx->name);
382 fill_filespec(pair->one, idx->sha1, idx->ce_mode);
383 return;
384 }
385 /*
387 * Something added to the tree?
388 */
389 if (!tree) {
390 show_new_file(revs, idx, cached, match_missing);
391 return;
392 }
393 /*
395 * Something removed from the tree?
396 */
397 if (!idx) {
398 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
399 return;
400 }
401 /* Show difference between old and new */
403 show_modified(revs, tree, idx, 1, cached, match_missing);
404}
405/*
407 * The unpack_trees() interface is designed for merging, so
408 * the different source entries are designed primarily for
409 * the source trees, with the old index being really mainly
410 * used for being replaced by the result.
411 *
412 * For diffing, the index is more important, and we only have a
413 * single tree.
414 *
415 * We're supposed to advance o->pos to skip what we have already processed.
416 *
417 * This wrapper makes it all more readable, and takes care of all
418 * the fairly complex unpack_trees() semantic requirements, including
419 * the skipping, the path matching, the type conflict cases etc.
420 */
421static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
422{
423 struct cache_entry *idx = src[0];
424 struct cache_entry *tree = src[1];
425 struct rev_info *revs = o->unpack_data;
426 /*
428 * Unpack-trees generates a DF/conflict entry if
429 * there was a directory in the index and a tree
430 * in the tree. From a diff standpoint, that's a
431 * delete of the tree and a create of the file.
432 */
433 if (tree == o->df_conflict_entry)
434 tree = NULL;
435 if (ce_path_match(idx ? idx : tree, &revs->prune_data))
437 do_oneway_diff(o, idx, tree);
438 return 0;
440}
441int run_diff_index(struct rev_info *revs, int cached)
443{
444 struct object *ent;
445 struct tree *tree;
446 const char *tree_name;
447 struct unpack_trees_options opts;
448 struct tree_desc t;
449 ent = revs->pending.objects[0].item;
451 tree_name = revs->pending.objects[0].name;
452 tree = parse_tree_indirect(ent->sha1);
453 if (!tree)
454 return error("bad tree object %s", tree_name);
455 memset(&opts, 0, sizeof(opts));
457 opts.head_idx = 1;
458 opts.index_only = cached;
459 opts.diff_index_cached = (cached &&
460 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
461 opts.merge = 1;
462 opts.fn = oneway_diff;
463 opts.unpack_data = revs;
464 opts.src_index = &the_index;
465 opts.dst_index = NULL;
466 init_tree_desc(&t, tree->buffer, tree->size);
468 if (unpack_trees(1, &t, &opts))
469 exit(128);
470 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
472 diffcore_fix_diff_index(&revs->diffopt);
473 diffcore_std(&revs->diffopt);
474 diff_flush(&revs->diffopt);
475 return 0;
476}
477int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
479{
480 struct tree *tree;
481 struct rev_info revs;
482 int i;
483 struct cache_entry **dst;
484 struct cache_entry *last = NULL;
485 struct unpack_trees_options opts;
486 struct tree_desc t;
487 /*
489 * This is used by git-blame to run diff-cache internally;
490 * it potentially needs to repeatedly run this, so we will
491 * start by removing the higher order entries the last round
492 * left behind.
493 */
494 dst = active_cache;
495 for (i = 0; i < active_nr; i++) {
496 struct cache_entry *ce = active_cache[i];
497 if (ce_stage(ce)) {
498 if (last && !strcmp(ce->name, last->name))
499 continue;
500 cache_tree_invalidate_path(active_cache_tree,
501 ce->name);
502 last = ce;
503 ce->ce_flags |= CE_REMOVE;
504 }
505 *dst++ = ce;
506 }
507 active_nr = dst - active_cache;
508 init_revisions(&revs, NULL);
510 init_pathspec(&revs.prune_data, opt->pathspec.raw);
511 tree = parse_tree_indirect(tree_sha1);
512 if (!tree)
513 die("bad tree object %s", sha1_to_hex(tree_sha1));
514 memset(&opts, 0, sizeof(opts));
516 opts.head_idx = 1;
517 opts.index_only = 1;
518 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
519 opts.merge = 1;
520 opts.fn = oneway_diff;
521 opts.unpack_data = &revs;
522 opts.src_index = &the_index;
523 opts.dst_index = &the_index;
524 init_tree_desc(&t, tree->buffer, tree->size);
526 if (unpack_trees(1, &t, &opts))
527 exit(128);
528 return 0;
529}
530int index_differs_from(const char *def, int diff_flags)
532{
533 struct rev_info rev;
534 struct setup_revision_opt opt;
535 init_revisions(&rev, NULL);
537 memset(&opt, 0, sizeof(opt));
538 opt.def = def;
539 setup_revisions(0, NULL, &rev, &opt);
540 DIFF_OPT_SET(&rev.diffopt, QUICK);
541 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
542 rev.diffopt.flags |= diff_flags;
543 run_diff_index(&rev, 1);
544 if (rev.pending.alloc)
545 free(rev.pending.objects);
546 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
547}