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/*
17 * diff-files
18 */
19/*
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 */
29static int check_removed(const struct cache_entry *ce, struct stat *st)
30{
31 if (lstat(ce->name, st) < 0) {
32 if (errno != ENOENT && errno != ENOTDIR)
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 /*
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/*
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 */
67static 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 unsigned orig_flags = diffopt->flags;
75 if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
76 set_diffopt_flags_from_submodule_config(diffopt, ce->name);
77 if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
78 changed = 0;
79 else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
80 && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
81 *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
82 diffopt->flags = orig_flags;
83 }
84 return changed;
85}
86int run_diff_files(struct rev_info *revs, unsigned int option)
88{
89 int entries, i;
90 int diff_unmerged_stage = revs->max_count;
91 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
92 ? CE_MATCH_RACY_IS_DIRTY : 0);
93 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
95 if (diff_unmerged_stage < 0)
97 diff_unmerged_stage = 2;
98 entries = active_nr;
99 for (i = 0; i < entries; i++) {
100 struct stat st;
101 unsigned int oldmode, newmode;
102 struct cache_entry *ce = active_cache[i];
103 int changed;
104 unsigned dirty_submodule = 0;
105 if (diff_can_quit_early(&revs->diffopt))
107 break;
108 if (!ce_path_match(ce, &revs->prune_data, NULL))
110 continue;
111 if (ce_stage(ce)) {
113 struct combine_diff_path *dpath;
114 struct diff_filepair *pair;
115 unsigned int wt_mode = 0;
116 int num_compare_stages = 0;
117 size_t path_len;
118 path_len = ce_namelen(ce);
120 dpath = xmalloc(combine_diff_path_size(5, path_len));
122 dpath->path = (char *) &(dpath->parent[5]);
123 dpath->next = NULL;
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 wt_mode = 0;
140 }
141 dpath->mode = wt_mode;
142 while (i < entries) {
144 struct cache_entry *nce = active_cache[i];
145 int stage;
146 if (strcmp(ce->name, nce->name))
148 break;
149 /* 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 /* 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 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 /*
184 * Show the diff for the 'ce' if we found the one
185 * from the desired stage.
186 */
187 pair = diff_unmerge(&revs->diffopt, ce->name);
188 if (wt_mode)
189 pair->two->mode = wt_mode;
190 if (ce_stage(ce) != diff_unmerged_stage)
191 continue;
192 }
193 if (ce_uptodate(ce) || ce_skip_worktree(ce))
195 continue;
196 /* If CE_VALID is set, don't look at workdir for file removal */
198 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
199 if (changed) {
200 if (changed < 0) {
201 perror(ce->name);
202 continue;
203 }
204 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
205 ce->sha1, !is_null_sha1(ce->sha1),
206 ce->name, 0);
207 continue;
208 }
209 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
210 ce_option, &dirty_submodule);
211 if (!changed && !dirty_submodule) {
212 ce_mark_uptodate(ce);
213 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
214 continue;
215 }
216 oldmode = ce->ce_mode;
217 newmode = ce_mode_from_stat(ce, st.st_mode);
218 diff_change(&revs->diffopt, oldmode, newmode,
219 ce->sha1, (changed ? null_sha1 : ce->sha1),
220 !is_null_sha1(ce->sha1), (changed ? 0 : !is_null_sha1(ce->sha1)),
221 ce->name, 0, dirty_submodule);
222 }
224 diffcore_std(&revs->diffopt);
225 diff_flush(&revs->diffopt);
226 return 0;
227}
228/*
230 * diff-index
231 */
232/* A file entry went away or appeared */
234static void diff_index_show_file(struct rev_info *revs,
235 const char *prefix,
236 const struct cache_entry *ce,
237 const unsigned char *sha1, int sha1_valid,
238 unsigned int mode,
239 unsigned dirty_submodule)
240{
241 diff_addremove(&revs->diffopt, prefix[0], mode,
242 sha1, sha1_valid, ce->name, dirty_submodule);
243}
244static int get_stat_data(const struct cache_entry *ce,
246 const unsigned char **sha1p,
247 unsigned int *modep,
248 int cached, int match_missing,
249 unsigned *dirty_submodule, struct diff_options *diffopt)
250{
251 const unsigned char *sha1 = ce->sha1;
252 unsigned int mode = ce->ce_mode;
253 if (!cached && !ce_uptodate(ce)) {
255 int changed;
256 struct stat st;
257 changed = check_removed(ce, &st);
258 if (changed < 0)
259 return -1;
260 else if (changed) {
261 if (match_missing) {
262 *sha1p = sha1;
263 *modep = mode;
264 return 0;
265 }
266 return -1;
267 }
268 changed = match_stat_with_submodule(diffopt, ce, &st,
269 0, dirty_submodule);
270 if (changed) {
271 mode = ce_mode_from_stat(ce, st.st_mode);
272 sha1 = null_sha1;
273 }
274 }
275 *sha1p = sha1;
277 *modep = mode;
278 return 0;
279}
280static void show_new_file(struct rev_info *revs,
282 const struct cache_entry *new,
283 int cached, int match_missing)
284{
285 const unsigned char *sha1;
286 unsigned int mode;
287 unsigned dirty_submodule = 0;
288 /*
290 * New file in the index: it might actually be different in
291 * the working tree.
292 */
293 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
294 &dirty_submodule, &revs->diffopt) < 0)
295 return;
296 diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
298}
299static int show_modified(struct rev_info *revs,
301 const struct cache_entry *old,
302 const struct cache_entry *new,
303 int report_missing,
304 int cached, int match_missing)
305{
306 unsigned int mode, oldmode;
307 const unsigned char *sha1;
308 unsigned dirty_submodule = 0;
309 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
311 &dirty_submodule, &revs->diffopt) < 0) {
312 if (report_missing)
313 diff_index_show_file(revs, "-", old,
314 old->sha1, 1, old->ce_mode, 0);
315 return -1;
316 }
317 if (revs->combine_merges && !cached &&
319 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
320 struct combine_diff_path *p;
321 int pathlen = ce_namelen(new);
322 p = xmalloc(combine_diff_path_size(2, pathlen));
324 p->path = (char *) &p->parent[2];
325 p->next = NULL;
326 memcpy(p->path, new->name, pathlen);
327 p->path[pathlen] = 0;
328 p->mode = mode;
329 hashclr(p->sha1);
330 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
331 p->parent[0].status = DIFF_STATUS_MODIFIED;
332 p->parent[0].mode = new->ce_mode;
333 hashcpy(p->parent[0].sha1, new->sha1);
334 p->parent[1].status = DIFF_STATUS_MODIFIED;
335 p->parent[1].mode = old->ce_mode;
336 hashcpy(p->parent[1].sha1, old->sha1);
337 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
338 free(p);
339 return 0;
340 }
341 oldmode = old->ce_mode;
343 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
344 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
345 return 0;
346 diff_change(&revs->diffopt, oldmode, mode,
348 old->sha1, sha1, 1, !is_null_sha1(sha1),
349 old->name, 0, dirty_submodule);
350 return 0;
351}
352/*
354 * This gets a mix of an existing index and a tree, one pathname entry
355 * at a time. The index entry may be a single stage-0 one, but it could
356 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
357 * give you the position and number of entries in the index).
358 */
359static void do_oneway_diff(struct unpack_trees_options *o,
360 const struct cache_entry *idx,
361 const struct cache_entry *tree)
362{
363 struct rev_info *revs = o->unpack_data;
364 int match_missing, cached;
365 /* if the entry is not checked out, don't examine work tree */
367 cached = o->index_only ||
368 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
369 /*
370 * Backward compatibility wart - "diff-index -m" does
371 * not mean "do not ignore merges", but "match_missing".
372 *
373 * But with the revision flag parsing, that's found in
374 * "!revs->ignore_merges".
375 */
376 match_missing = !revs->ignore_merges;
377 if (cached && idx && ce_stage(idx)) {
379 struct diff_filepair *pair;
380 pair = diff_unmerge(&revs->diffopt, idx->name);
381 if (tree)
382 fill_filespec(pair->one, tree->sha1, 1, tree->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, 1, 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(const struct cache_entry * const *src,
422 struct unpack_trees_options *o)
423{
424 const struct cache_entry *idx = src[0];
425 const struct cache_entry *tree = src[1];
426 struct rev_info *revs = o->unpack_data;
427 /*
429 * Unpack-trees generates a DF/conflict entry if
430 * there was a directory in the index and a tree
431 * in the tree. From a diff standpoint, that's a
432 * delete of the tree and a create of the file.
433 */
434 if (tree == o->df_conflict_entry)
435 tree = NULL;
436 if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
438 do_oneway_diff(o, idx, tree);
439 if (diff_can_quit_early(&revs->diffopt)) {
440 o->exiting_early = 1;
441 return -1;
442 }
443 }
444 return 0;
446}
447static int diff_cache(struct rev_info *revs,
449 const unsigned char *tree_sha1,
450 const char *tree_name,
451 int cached)
452{
453 struct tree *tree;
454 struct tree_desc t;
455 struct unpack_trees_options opts;
456 tree = parse_tree_indirect(tree_sha1);
458 if (!tree)
459 return error("bad tree object %s",
460 tree_name ? tree_name : sha1_to_hex(tree_sha1));
461 memset(&opts, 0, sizeof(opts));
462 opts.head_idx = 1;
463 opts.index_only = cached;
464 opts.diff_index_cached = (cached &&
465 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
466 opts.merge = 1;
467 opts.fn = oneway_diff;
468 opts.unpack_data = revs;
469 opts.src_index = &the_index;
470 opts.dst_index = NULL;
471 opts.pathspec = &revs->diffopt.pathspec;
472 opts.pathspec->recursive = 1;
473 init_tree_desc(&t, tree->buffer, tree->size);
475 return unpack_trees(1, &t, &opts);
476}
477int run_diff_index(struct rev_info *revs, int cached)
479{
480 struct object_array_entry *ent;
481 ent = revs->pending.objects;
483 if (diff_cache(revs, ent->item->sha1, ent->name, cached))
484 exit(128);
485 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
487 diffcore_fix_diff_index(&revs->diffopt);
488 diffcore_std(&revs->diffopt);
489 diff_flush(&revs->diffopt);
490 return 0;
491}
492int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
494{
495 struct rev_info revs;
496 init_revisions(&revs, NULL);
498 copy_pathspec(&revs.prune_data, &opt->pathspec);
499 revs.diffopt = *opt;
500 if (diff_cache(&revs, tree_sha1, NULL, 1))
502 exit(128);
503 return 0;
504}
505int index_differs_from(const char *def, int diff_flags)
507{
508 struct rev_info rev;
509 struct setup_revision_opt opt;
510 init_revisions(&rev, NULL);
512 memset(&opt, 0, sizeof(opt));
513 opt.def = def;
514 setup_revisions(0, NULL, &rev, &opt);
515 DIFF_OPT_SET(&rev.diffopt, QUICK);
516 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
517 rev.diffopt.flags |= diff_flags;
518 run_diff_index(&rev, 1);
519 if (rev.pending.alloc)
520 free(rev.pending.objects);
521 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
522}