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_OPT_TST(&revs->diffopt, QUICK) &&
106 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
107 break;
108 if (!ce_path_match(ce, revs->prune_data))
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 dpath->len = path_len;
126 memcpy(dpath->path, ce->name, path_len);
127 dpath->path[path_len] = '\0';
128 hashclr(dpath->sha1);
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 if (silent_on_removed)
141 continue;
142 wt_mode = 0;
143 }
144 dpath->mode = wt_mode;
145 while (i < entries) {
147 struct cache_entry *nce = active_cache[i];
148 int stage;
149 if (strcmp(ce->name, nce->name))
151 break;
152 /* Stage #2 (ours) is the first parent,
154 * stage #3 (theirs) is the second.
155 */
156 stage = ce_stage(nce);
157 if (2 <= stage) {
158 int mode = nce->ce_mode;
159 num_compare_stages++;
160 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
161 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
162 dpath->parent[stage-2].status =
163 DIFF_STATUS_MODIFIED;
164 }
165 /* diff against the proper unmerged stage */
167 if (stage == diff_unmerged_stage)
168 ce = nce;
169 i++;
170 }
171 /*
172 * Compensate for loop update
173 */
174 i--;
175 if (revs->combine_merges && num_compare_stages == 2) {
177 show_combined_diff(dpath, 2,
178 revs->dense_combined_merges,
179 revs);
180 free(dpath);
181 continue;
182 }
183 free(dpath);
184 dpath = NULL;
185 /*
187 * Show the diff for the 'ce' if we found the one
188 * from the desired stage.
189 */
190 pair = diff_unmerge(&revs->diffopt, ce->name);
191 if (wt_mode)
192 pair->two->mode = wt_mode;
193 if (ce_stage(ce) != diff_unmerged_stage)
194 continue;
195 }
196 if (ce_uptodate(ce) || ce_skip_worktree(ce))
198 continue;
199 /* If CE_VALID is set, don't look at workdir for file removal */
201 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
202 if (changed) {
203 if (changed < 0) {
204 perror(ce->name);
205 continue;
206 }
207 if (silent_on_removed)
208 continue;
209 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
210 ce->sha1, ce->name, 0);
211 continue;
212 }
213 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
214 ce_option, &dirty_submodule);
215 if (!changed && !dirty_submodule) {
216 ce_mark_uptodate(ce);
217 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
218 continue;
219 }
220 oldmode = ce->ce_mode;
221 newmode = ce_mode_from_stat(ce, st.st_mode);
222 diff_change(&revs->diffopt, oldmode, newmode,
223 ce->sha1, (changed ? null_sha1 : ce->sha1),
224 ce->name, 0, dirty_submodule);
225 }
227 diffcore_std(&revs->diffopt);
228 diff_flush(&revs->diffopt);
229 return 0;
230}
231/*
233 * diff-index
234 */
235/* A file entry went away or appeared */
237static void diff_index_show_file(struct rev_info *revs,
238 const char *prefix,
239 struct cache_entry *ce,
240 const unsigned char *sha1, unsigned int mode,
241 unsigned dirty_submodule)
242{
243 diff_addremove(&revs->diffopt, prefix[0], mode,
244 sha1, ce->name, dirty_submodule);
245}
246static int get_stat_data(struct cache_entry *ce,
248 const unsigned char **sha1p,
249 unsigned int *modep,
250 int cached, int match_missing,
251 unsigned *dirty_submodule, struct diff_options *diffopt)
252{
253 const unsigned char *sha1 = ce->sha1;
254 unsigned int mode = ce->ce_mode;
255 if (!cached && !ce_uptodate(ce)) {
257 int changed;
258 struct stat st;
259 changed = check_removed(ce, &st);
260 if (changed < 0)
261 return -1;
262 else if (changed) {
263 if (match_missing) {
264 *sha1p = sha1;
265 *modep = mode;
266 return 0;
267 }
268 return -1;
269 }
270 changed = match_stat_with_submodule(diffopt, ce, &st,
271 0, dirty_submodule);
272 if (changed) {
273 mode = ce_mode_from_stat(ce, st.st_mode);
274 sha1 = null_sha1;
275 }
276 }
277 *sha1p = sha1;
279 *modep = mode;
280 return 0;
281}
282static void show_new_file(struct rev_info *revs,
284 struct cache_entry *new,
285 int cached, int match_missing)
286{
287 const unsigned char *sha1;
288 unsigned int mode;
289 unsigned dirty_submodule = 0;
290 /*
292 * New file in the index: it might actually be different in
293 * the working copy.
294 */
295 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
296 &dirty_submodule, &revs->diffopt) < 0)
297 return;
298 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
300}
301static int show_modified(struct rev_info *revs,
303 struct cache_entry *old,
304 struct cache_entry *new,
305 int report_missing,
306 int cached, int match_missing)
307{
308 unsigned int mode, oldmode;
309 const unsigned char *sha1;
310 unsigned dirty_submodule = 0;
311 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
313 &dirty_submodule, &revs->diffopt) < 0) {
314 if (report_missing)
315 diff_index_show_file(revs, "-", old,
316 old->sha1, old->ce_mode, 0);
317 return -1;
318 }
319 if (revs->combine_merges && !cached &&
321 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
322 struct combine_diff_path *p;
323 int pathlen = ce_namelen(new);
324 p = xmalloc(combine_diff_path_size(2, pathlen));
326 p->path = (char *) &p->parent[2];
327 p->next = NULL;
328 p->len = pathlen;
329 memcpy(p->path, new->name, pathlen);
330 p->path[pathlen] = 0;
331 p->mode = mode;
332 hashclr(p->sha1);
333 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
334 p->parent[0].status = DIFF_STATUS_MODIFIED;
335 p->parent[0].mode = new->ce_mode;
336 hashcpy(p->parent[0].sha1, new->sha1);
337 p->parent[1].status = DIFF_STATUS_MODIFIED;
338 p->parent[1].mode = old->ce_mode;
339 hashcpy(p->parent[1].sha1, old->sha1);
340 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
341 free(p);
342 return 0;
343 }
344 oldmode = old->ce_mode;
346 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
347 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
348 return 0;
349 diff_change(&revs->diffopt, oldmode, mode,
351 old->sha1, sha1, old->name, 0, dirty_submodule);
352 return 0;
353}
354/*
356 * This gets a mix of an existing index and a tree, one pathname entry
357 * at a time. The index entry may be a single stage-0 one, but it could
358 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
359 * give you the position and number of entries in the index).
360 */
361static void do_oneway_diff(struct unpack_trees_options *o,
362 struct cache_entry *idx,
363 struct cache_entry *tree)
364{
365 struct rev_info *revs = o->unpack_data;
366 int match_missing, cached;
367 /* if the entry is not checked out, don't examine work tree */
369 cached = o->index_only ||
370 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
371 /*
372 * Backward compatibility wart - "diff-index -m" does
373 * not mean "do not ignore merges", but "match_missing".
374 *
375 * But with the revision flag parsing, that's found in
376 * "!revs->ignore_merges".
377 */
378 match_missing = !revs->ignore_merges;
379 if (cached && idx && ce_stage(idx)) {
381 struct diff_filepair *pair;
382 pair = diff_unmerge(&revs->diffopt, idx->name);
383 fill_filespec(pair->one, idx->sha1, idx->ce_mode);
384 return;
385 }
386 /*
388 * Something added to the tree?
389 */
390 if (!tree) {
391 show_new_file(revs, idx, cached, match_missing);
392 return;
393 }
394 /*
396 * Something removed from the tree?
397 */
398 if (!idx) {
399 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
400 return;
401 }
402 /* Show difference between old and new */
404 show_modified(revs, tree, idx, 1, cached, match_missing);
405}
406/*
408 * The unpack_trees() interface is designed for merging, so
409 * the different source entries are designed primarily for
410 * the source trees, with the old index being really mainly
411 * used for being replaced by the result.
412 *
413 * For diffing, the index is more important, and we only have a
414 * single tree.
415 *
416 * We're supposed to advance o->pos to skip what we have already processed.
417 *
418 * This wrapper makes it all more readable, and takes care of all
419 * the fairly complex unpack_trees() semantic requirements, including
420 * the skipping, the path matching, the type conflict cases etc.
421 */
422static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
423{
424 struct cache_entry *idx = src[0];
425 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))
438 do_oneway_diff(o, idx, tree);
439 return 0;
441}
442int run_diff_index(struct rev_info *revs, int cached)
444{
445 struct object *ent;
446 struct tree *tree;
447 const char *tree_name;
448 struct unpack_trees_options opts;
449 struct tree_desc t;
450 ent = revs->pending.objects[0].item;
452 tree_name = revs->pending.objects[0].name;
453 tree = parse_tree_indirect(ent->sha1);
454 if (!tree)
455 return error("bad tree object %s", tree_name);
456 memset(&opts, 0, sizeof(opts));
458 opts.head_idx = 1;
459 opts.index_only = cached;
460 opts.diff_index_cached = (cached &&
461 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
462 opts.merge = 1;
463 opts.fn = oneway_diff;
464 opts.unpack_data = revs;
465 opts.src_index = &the_index;
466 opts.dst_index = NULL;
467 init_tree_desc(&t, tree->buffer, tree->size);
469 if (unpack_trees(1, &t, &opts))
470 exit(128);
471 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
473 diffcore_fix_diff_index(&revs->diffopt);
474 diffcore_std(&revs->diffopt);
475 diff_flush(&revs->diffopt);
476 return 0;
477}
478int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
480{
481 struct tree *tree;
482 struct rev_info revs;
483 int i;
484 struct cache_entry **dst;
485 struct cache_entry *last = NULL;
486 struct unpack_trees_options opts;
487 struct tree_desc t;
488 /*
490 * This is used by git-blame to run diff-cache internally;
491 * it potentially needs to repeatedly run this, so we will
492 * start by removing the higher order entries the last round
493 * left behind.
494 */
495 dst = active_cache;
496 for (i = 0; i < active_nr; i++) {
497 struct cache_entry *ce = active_cache[i];
498 if (ce_stage(ce)) {
499 if (last && !strcmp(ce->name, last->name))
500 continue;
501 cache_tree_invalidate_path(active_cache_tree,
502 ce->name);
503 last = ce;
504 ce->ce_flags |= CE_REMOVE;
505 }
506 *dst++ = ce;
507 }
508 active_nr = dst - active_cache;
509 init_revisions(&revs, NULL);
511 revs.prune_data = opt->paths;
512 tree = parse_tree_indirect(tree_sha1);
513 if (!tree)
514 die("bad tree object %s", sha1_to_hex(tree_sha1));
515 memset(&opts, 0, sizeof(opts));
517 opts.head_idx = 1;
518 opts.index_only = 1;
519 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
520 opts.merge = 1;
521 opts.fn = oneway_diff;
522 opts.unpack_data = &revs;
523 opts.src_index = &the_index;
524 opts.dst_index = &the_index;
525 init_tree_desc(&t, tree->buffer, tree->size);
527 if (unpack_trees(1, &t, &opts))
528 exit(128);
529 return 0;
530}
531int index_differs_from(const char *def, int diff_flags)
533{
534 struct rev_info rev;
535 struct setup_revision_opt opt;
536 init_revisions(&rev, NULL);
538 memset(&opt, 0, sizeof(opt));
539 opt.def = def;
540 setup_revisions(0, NULL, &rev, &opt);
541 DIFF_OPT_SET(&rev.diffopt, QUICK);
542 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
543 rev.diffopt.flags |= diff_flags;
544 run_diff_index(&rev, 1);
545 if (rev.pending.alloc)
546 free(rev.pending.objects);
547 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
548}