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 unsigned int oldmode, newmode;
101 struct cache_entry *ce = active_cache[i];
102 int changed;
103 unsigned dirty_submodule = 0;
104 const unsigned char *old_sha1, *new_sha1;
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 struct stat st;
119 path_len = ce_namelen(ce);
121 dpath = xmalloc(combine_diff_path_size(5, path_len));
123 dpath->path = (char *) &(dpath->parent[5]);
124 dpath->next = NULL;
126 memcpy(dpath->path, ce->name, path_len);
127 dpath->path[path_len] = '\0';
128 oidclr(&dpath->oid);
129 memset(&(dpath->parent[0]), 0,
130 sizeof(struct combine_diff_parent)*5);
131 changed = check_removed(ce, &st);
133 if (!changed)
134 wt_mode = ce_mode_from_stat(ce, st.st_mode);
135 else {
136 if (changed < 0) {
137 perror(ce->name);
138 continue;
139 }
140 wt_mode = 0;
141 }
142 dpath->mode = wt_mode;
143 while (i < entries) {
145 struct cache_entry *nce = active_cache[i];
146 int stage;
147 if (strcmp(ce->name, nce->name))
149 break;
150 /* Stage #2 (ours) is the first parent,
152 * stage #3 (theirs) is the second.
153 */
154 stage = ce_stage(nce);
155 if (2 <= stage) {
156 int mode = nce->ce_mode;
157 num_compare_stages++;
158 hashcpy(dpath->parent[stage-2].oid.hash, nce->sha1);
159 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
160 dpath->parent[stage-2].status =
161 DIFF_STATUS_MODIFIED;
162 }
163 /* diff against the proper unmerged stage */
165 if (stage == diff_unmerged_stage)
166 ce = nce;
167 i++;
168 }
169 /*
170 * Compensate for loop update
171 */
172 i--;
173 if (revs->combine_merges && num_compare_stages == 2) {
175 show_combined_diff(dpath, 2,
176 revs->dense_combined_merges,
177 revs);
178 free(dpath);
179 continue;
180 }
181 free(dpath);
182 dpath = NULL;
183 /*
185 * Show the diff for the 'ce' if we found the one
186 * from the desired stage.
187 */
188 pair = diff_unmerge(&revs->diffopt, ce->name);
189 if (wt_mode)
190 pair->two->mode = wt_mode;
191 if (ce_stage(ce) != diff_unmerged_stage)
192 continue;
193 }
194 if (ce_uptodate(ce) || ce_skip_worktree(ce))
196 continue;
197 /* If CE_VALID is set, don't look at workdir for file removal */
199 if (ce->ce_flags & CE_VALID) {
200 changed = 0;
201 newmode = ce->ce_mode;
202 } else {
203 struct stat st;
204 changed = check_removed(ce, &st);
206 if (changed) {
207 if (changed < 0) {
208 perror(ce->name);
209 continue;
210 }
211 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
212 ce->sha1, !is_null_sha1(ce->sha1),
213 ce->name, 0);
214 continue;
215 }
216 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
218 ce_option, &dirty_submodule);
219 newmode = ce_mode_from_stat(ce, st.st_mode);
220 }
221 if (!changed && !dirty_submodule) {
223 ce_mark_uptodate(ce);
224 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
225 continue;
226 }
227 oldmode = ce->ce_mode;
228 old_sha1 = ce->sha1;
229 new_sha1 = changed ? null_sha1 : ce->sha1;
230 diff_change(&revs->diffopt, oldmode, newmode,
231 old_sha1, new_sha1,
232 !is_null_sha1(old_sha1),
233 !is_null_sha1(new_sha1),
234 ce->name, 0, dirty_submodule);
235 }
237 diffcore_std(&revs->diffopt);
238 diff_flush(&revs->diffopt);
239 return 0;
240}
241/*
243 * diff-index
244 */
245/* A file entry went away or appeared */
247static void diff_index_show_file(struct rev_info *revs,
248 const char *prefix,
249 const struct cache_entry *ce,
250 const unsigned char *sha1, int sha1_valid,
251 unsigned int mode,
252 unsigned dirty_submodule)
253{
254 diff_addremove(&revs->diffopt, prefix[0], mode,
255 sha1, sha1_valid, ce->name, dirty_submodule);
256}
257static int get_stat_data(const struct cache_entry *ce,
259 const unsigned char **sha1p,
260 unsigned int *modep,
261 int cached, int match_missing,
262 unsigned *dirty_submodule, struct diff_options *diffopt)
263{
264 const unsigned char *sha1 = ce->sha1;
265 unsigned int mode = ce->ce_mode;
266 if (!cached && !ce_uptodate(ce)) {
268 int changed;
269 struct stat st;
270 changed = check_removed(ce, &st);
271 if (changed < 0)
272 return -1;
273 else if (changed) {
274 if (match_missing) {
275 *sha1p = sha1;
276 *modep = mode;
277 return 0;
278 }
279 return -1;
280 }
281 changed = match_stat_with_submodule(diffopt, ce, &st,
282 0, dirty_submodule);
283 if (changed) {
284 mode = ce_mode_from_stat(ce, st.st_mode);
285 sha1 = null_sha1;
286 }
287 }
288 *sha1p = sha1;
290 *modep = mode;
291 return 0;
292}
293static void show_new_file(struct rev_info *revs,
295 const struct cache_entry *new,
296 int cached, int match_missing)
297{
298 const unsigned char *sha1;
299 unsigned int mode;
300 unsigned dirty_submodule = 0;
301 /*
303 * New file in the index: it might actually be different in
304 * the working tree.
305 */
306 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
307 &dirty_submodule, &revs->diffopt) < 0)
308 return;
309 diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
311}
312static int show_modified(struct rev_info *revs,
314 const struct cache_entry *old,
315 const struct cache_entry *new,
316 int report_missing,
317 int cached, int match_missing)
318{
319 unsigned int mode, oldmode;
320 const unsigned char *sha1;
321 unsigned dirty_submodule = 0;
322 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
324 &dirty_submodule, &revs->diffopt) < 0) {
325 if (report_missing)
326 diff_index_show_file(revs, "-", old,
327 old->sha1, 1, old->ce_mode, 0);
328 return -1;
329 }
330 if (revs->combine_merges && !cached &&
332 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
333 struct combine_diff_path *p;
334 int pathlen = ce_namelen(new);
335 p = xmalloc(combine_diff_path_size(2, pathlen));
337 p->path = (char *) &p->parent[2];
338 p->next = NULL;
339 memcpy(p->path, new->name, pathlen);
340 p->path[pathlen] = 0;
341 p->mode = mode;
342 oidclr(&p->oid);
343 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
344 p->parent[0].status = DIFF_STATUS_MODIFIED;
345 p->parent[0].mode = new->ce_mode;
346 hashcpy(p->parent[0].oid.hash, new->sha1);
347 p->parent[1].status = DIFF_STATUS_MODIFIED;
348 p->parent[1].mode = old->ce_mode;
349 hashcpy(p->parent[1].oid.hash, old->sha1);
350 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
351 free(p);
352 return 0;
353 }
354 oldmode = old->ce_mode;
356 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
357 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
358 return 0;
359 diff_change(&revs->diffopt, oldmode, mode,
361 old->sha1, sha1, 1, !is_null_sha1(sha1),
362 old->name, 0, dirty_submodule);
363 return 0;
364}
365/*
367 * This gets a mix of an existing index and a tree, one pathname entry
368 * at a time. The index entry may be a single stage-0 one, but it could
369 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
370 * give you the position and number of entries in the index).
371 */
372static void do_oneway_diff(struct unpack_trees_options *o,
373 const struct cache_entry *idx,
374 const struct cache_entry *tree)
375{
376 struct rev_info *revs = o->unpack_data;
377 int match_missing, cached;
378 /* if the entry is not checked out, don't examine work tree */
380 cached = o->index_only ||
381 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
382 /*
383 * Backward compatibility wart - "diff-index -m" does
384 * not mean "do not ignore merges", but "match_missing".
385 *
386 * But with the revision flag parsing, that's found in
387 * "!revs->ignore_merges".
388 */
389 match_missing = !revs->ignore_merges;
390 if (cached && idx && ce_stage(idx)) {
392 struct diff_filepair *pair;
393 pair = diff_unmerge(&revs->diffopt, idx->name);
394 if (tree)
395 fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
396 return;
397 }
398 /*
400 * Something added to the tree?
401 */
402 if (!tree) {
403 show_new_file(revs, idx, cached, match_missing);
404 return;
405 }
406 /*
408 * Something removed from the tree?
409 */
410 if (!idx) {
411 diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
412 return;
413 }
414 /* Show difference between old and new */
416 show_modified(revs, tree, idx, 1, cached, match_missing);
417}
418/*
420 * The unpack_trees() interface is designed for merging, so
421 * the different source entries are designed primarily for
422 * the source trees, with the old index being really mainly
423 * used for being replaced by the result.
424 *
425 * For diffing, the index is more important, and we only have a
426 * single tree.
427 *
428 * We're supposed to advance o->pos to skip what we have already processed.
429 *
430 * This wrapper makes it all more readable, and takes care of all
431 * the fairly complex unpack_trees() semantic requirements, including
432 * the skipping, the path matching, the type conflict cases etc.
433 */
434static int oneway_diff(const struct cache_entry * const *src,
435 struct unpack_trees_options *o)
436{
437 const struct cache_entry *idx = src[0];
438 const struct cache_entry *tree = src[1];
439 struct rev_info *revs = o->unpack_data;
440 /*
442 * Unpack-trees generates a DF/conflict entry if
443 * there was a directory in the index and a tree
444 * in the tree. From a diff standpoint, that's a
445 * delete of the tree and a create of the file.
446 */
447 if (tree == o->df_conflict_entry)
448 tree = NULL;
449 if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
451 do_oneway_diff(o, idx, tree);
452 if (diff_can_quit_early(&revs->diffopt)) {
453 o->exiting_early = 1;
454 return -1;
455 }
456 }
457 return 0;
459}
460static int diff_cache(struct rev_info *revs,
462 const unsigned char *tree_sha1,
463 const char *tree_name,
464 int cached)
465{
466 struct tree *tree;
467 struct tree_desc t;
468 struct unpack_trees_options opts;
469 tree = parse_tree_indirect(tree_sha1);
471 if (!tree)
472 return error("bad tree object %s",
473 tree_name ? tree_name : sha1_to_hex(tree_sha1));
474 memset(&opts, 0, sizeof(opts));
475 opts.head_idx = 1;
476 opts.index_only = cached;
477 opts.diff_index_cached = (cached &&
478 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
479 opts.merge = 1;
480 opts.fn = oneway_diff;
481 opts.unpack_data = revs;
482 opts.src_index = &the_index;
483 opts.dst_index = NULL;
484 opts.pathspec = &revs->diffopt.pathspec;
485 opts.pathspec->recursive = 1;
486 init_tree_desc(&t, tree->buffer, tree->size);
488 return unpack_trees(1, &t, &opts);
489}
490int run_diff_index(struct rev_info *revs, int cached)
492{
493 struct object_array_entry *ent;
494 ent = revs->pending.objects;
496 if (diff_cache(revs, ent->item->oid.hash, ent->name, cached))
497 exit(128);
498 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
500 diffcore_fix_diff_index(&revs->diffopt);
501 diffcore_std(&revs->diffopt);
502 diff_flush(&revs->diffopt);
503 return 0;
504}
505int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
507{
508 struct rev_info revs;
509 init_revisions(&revs, NULL);
511 copy_pathspec(&revs.prune_data, &opt->pathspec);
512 revs.diffopt = *opt;
513 if (diff_cache(&revs, tree_sha1, NULL, 1))
515 exit(128);
516 return 0;
517}
518int index_differs_from(const char *def, int diff_flags)
520{
521 struct rev_info rev;
522 struct setup_revision_opt opt;
523 init_revisions(&rev, NULL);
525 memset(&opt, 0, sizeof(opt));
526 opt.def = def;
527 setup_revisions(0, NULL, &rev, &opt);
528 DIFF_OPT_SET(&rev.diffopt, QUICK);
529 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
530 rev.diffopt.flags |= diff_flags;
531 run_diff_index(&rev, 1);
532 if (rev.pending.alloc)
533 free(rev.pending.objects);
534 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
535}