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 int num_compare_stages = 0;
115 size_t path_len;
116 path_len = ce_namelen(ce);
118 dpath = xmalloc(combine_diff_path_size(5, path_len));
120 dpath->path = (char *) &(dpath->parent[5]);
121 dpath->next = NULL;
123 dpath->len = path_len;
124 memcpy(dpath->path, ce->name, path_len);
125 dpath->path[path_len] = '\0';
126 hashclr(dpath->sha1);
127 memset(&(dpath->parent[0]), 0,
128 sizeof(struct combine_diff_parent)*5);
129 changed = check_removed(ce, &st);
131 if (!changed)
132 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
133 else {
134 if (changed < 0) {
135 perror(ce->name);
136 continue;
137 }
138 if (silent_on_removed)
139 continue;
140 }
141 while (i < entries) {
143 struct cache_entry *nce = active_cache[i];
144 int stage;
145 if (strcmp(ce->name, nce->name))
147 break;
148 /* Stage #2 (ours) is the first parent,
150 * stage #3 (theirs) is the second.
151 */
152 stage = ce_stage(nce);
153 if (2 <= stage) {
154 int mode = nce->ce_mode;
155 num_compare_stages++;
156 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
157 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
158 dpath->parent[stage-2].status =
159 DIFF_STATUS_MODIFIED;
160 }
161 /* diff against the proper unmerged stage */
163 if (stage == diff_unmerged_stage)
164 ce = nce;
165 i++;
166 }
167 /*
168 * Compensate for loop update
169 */
170 i--;
171 if (revs->combine_merges && num_compare_stages == 2) {
173 show_combined_diff(dpath, 2,
174 revs->dense_combined_merges,
175 revs);
176 free(dpath);
177 continue;
178 }
179 free(dpath);
180 dpath = NULL;
181 /*
183 * Show the diff for the 'ce' if we found the one
184 * from the desired stage.
185 */
186 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
187 if (ce_stage(ce) != diff_unmerged_stage)
188 continue;
189 }
190 if (ce_uptodate(ce) || ce_skip_worktree(ce))
192 continue;
193 /* If CE_VALID is set, don't look at workdir for file removal */
195 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
196 if (changed) {
197 if (changed < 0) {
198 perror(ce->name);
199 continue;
200 }
201 if (silent_on_removed)
202 continue;
203 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
204 ce->sha1, ce->name, 0);
205 continue;
206 }
207 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
208 ce_option, &dirty_submodule);
209 if (!changed && !dirty_submodule) {
210 ce_mark_uptodate(ce);
211 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
212 continue;
213 }
214 oldmode = ce->ce_mode;
215 newmode = ce_mode_from_stat(ce, st.st_mode);
216 diff_change(&revs->diffopt, oldmode, newmode,
217 ce->sha1, (changed ? null_sha1 : ce->sha1),
218 ce->name, 0, dirty_submodule);
219 }
221 diffcore_std(&revs->diffopt);
222 diff_flush(&revs->diffopt);
223 return 0;
224}
225/*
227 * diff-index
228 */
229/* A file entry went away or appeared */
231static void diff_index_show_file(struct rev_info *revs,
232 const char *prefix,
233 struct cache_entry *ce,
234 const unsigned char *sha1, unsigned int mode,
235 unsigned dirty_submodule)
236{
237 diff_addremove(&revs->diffopt, prefix[0], mode,
238 sha1, ce->name, dirty_submodule);
239}
240static int get_stat_data(struct cache_entry *ce,
242 const unsigned char **sha1p,
243 unsigned int *modep,
244 int cached, int match_missing,
245 unsigned *dirty_submodule, struct diff_options *diffopt)
246{
247 const unsigned char *sha1 = ce->sha1;
248 unsigned int mode = ce->ce_mode;
249 if (!cached && !ce_uptodate(ce)) {
251 int changed;
252 struct stat st;
253 changed = check_removed(ce, &st);
254 if (changed < 0)
255 return -1;
256 else if (changed) {
257 if (match_missing) {
258 *sha1p = sha1;
259 *modep = mode;
260 return 0;
261 }
262 return -1;
263 }
264 changed = match_stat_with_submodule(diffopt, ce, &st,
265 0, dirty_submodule);
266 if (changed) {
267 mode = ce_mode_from_stat(ce, st.st_mode);
268 sha1 = null_sha1;
269 }
270 }
271 *sha1p = sha1;
273 *modep = mode;
274 return 0;
275}
276static void show_new_file(struct rev_info *revs,
278 struct cache_entry *new,
279 int cached, int match_missing)
280{
281 const unsigned char *sha1;
282 unsigned int mode;
283 unsigned dirty_submodule = 0;
284 /*
286 * New file in the index: it might actually be different in
287 * the working copy.
288 */
289 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
290 &dirty_submodule, &revs->diffopt) < 0)
291 return;
292 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
294}
295static int show_modified(struct rev_info *revs,
297 struct cache_entry *old,
298 struct cache_entry *new,
299 int report_missing,
300 int cached, int match_missing)
301{
302 unsigned int mode, oldmode;
303 const unsigned char *sha1;
304 unsigned dirty_submodule = 0;
305 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
307 &dirty_submodule, &revs->diffopt) < 0) {
308 if (report_missing)
309 diff_index_show_file(revs, "-", old,
310 old->sha1, old->ce_mode, 0);
311 return -1;
312 }
313 if (revs->combine_merges && !cached &&
315 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
316 struct combine_diff_path *p;
317 int pathlen = ce_namelen(new);
318 p = xmalloc(combine_diff_path_size(2, pathlen));
320 p->path = (char *) &p->parent[2];
321 p->next = NULL;
322 p->len = pathlen;
323 memcpy(p->path, new->name, pathlen);
324 p->path[pathlen] = 0;
325 p->mode = mode;
326 hashclr(p->sha1);
327 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
328 p->parent[0].status = DIFF_STATUS_MODIFIED;
329 p->parent[0].mode = new->ce_mode;
330 hashcpy(p->parent[0].sha1, new->sha1);
331 p->parent[1].status = DIFF_STATUS_MODIFIED;
332 p->parent[1].mode = old->ce_mode;
333 hashcpy(p->parent[1].sha1, old->sha1);
334 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
335 free(p);
336 return 0;
337 }
338 oldmode = old->ce_mode;
340 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
341 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
342 return 0;
343 diff_change(&revs->diffopt, oldmode, mode,
345 old->sha1, sha1, old->name, 0, dirty_submodule);
346 return 0;
347}
348/*
350 * This gets a mix of an existing index and a tree, one pathname entry
351 * at a time. The index entry may be a single stage-0 one, but it could
352 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
353 * give you the position and number of entries in the index).
354 */
355static void do_oneway_diff(struct unpack_trees_options *o,
356 struct cache_entry *idx,
357 struct cache_entry *tree)
358{
359 struct rev_info *revs = o->unpack_data;
360 int match_missing, cached;
361 /* if the entry is not checked out, don't examine work tree */
363 cached = o->index_only ||
364 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
365 /*
366 * Backward compatibility wart - "diff-index -m" does
367 * not mean "do not ignore merges", but "match_missing".
368 *
369 * But with the revision flag parsing, that's found in
370 * "!revs->ignore_merges".
371 */
372 match_missing = !revs->ignore_merges;
373 if (cached && idx && ce_stage(idx)) {
375 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
376 idx->sha1);
377 return;
378 }
379 /*
381 * Something added to the tree?
382 */
383 if (!tree) {
384 show_new_file(revs, idx, cached, match_missing);
385 return;
386 }
387 /*
389 * Something removed from the tree?
390 */
391 if (!idx) {
392 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
393 return;
394 }
395 /* Show difference between old and new */
397 show_modified(revs, tree, idx, 1, cached, match_missing);
398}
399/*
401 * The unpack_trees() interface is designed for merging, so
402 * the different source entries are designed primarily for
403 * the source trees, with the old index being really mainly
404 * used for being replaced by the result.
405 *
406 * For diffing, the index is more important, and we only have a
407 * single tree.
408 *
409 * We're supposed to advance o->pos to skip what we have already processed.
410 *
411 * This wrapper makes it all more readable, and takes care of all
412 * the fairly complex unpack_trees() semantic requirements, including
413 * the skipping, the path matching, the type conflict cases etc.
414 */
415static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
416{
417 struct cache_entry *idx = src[0];
418 struct cache_entry *tree = src[1];
419 struct rev_info *revs = o->unpack_data;
420 /*
422 * Unpack-trees generates a DF/conflict entry if
423 * there was a directory in the index and a tree
424 * in the tree. From a diff standpoint, that's a
425 * delete of the tree and a create of the file.
426 */
427 if (tree == o->df_conflict_entry)
428 tree = NULL;
429 if (ce_path_match(idx ? idx : tree, revs->prune_data))
431 do_oneway_diff(o, idx, tree);
432 return 0;
434}
435int run_diff_index(struct rev_info *revs, int cached)
437{
438 struct object *ent;
439 struct tree *tree;
440 const char *tree_name;
441 struct unpack_trees_options opts;
442 struct tree_desc t;
443 ent = revs->pending.objects[0].item;
445 tree_name = revs->pending.objects[0].name;
446 tree = parse_tree_indirect(ent->sha1);
447 if (!tree)
448 return error("bad tree object %s", tree_name);
449 memset(&opts, 0, sizeof(opts));
451 opts.head_idx = 1;
452 opts.index_only = cached;
453 opts.diff_index_cached = (cached &&
454 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
455 opts.merge = 1;
456 opts.fn = oneway_diff;
457 opts.unpack_data = revs;
458 opts.src_index = &the_index;
459 opts.dst_index = NULL;
460 init_tree_desc(&t, tree->buffer, tree->size);
462 if (unpack_trees(1, &t, &opts))
463 exit(128);
464 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
466 diffcore_fix_diff_index(&revs->diffopt);
467 diffcore_std(&revs->diffopt);
468 diff_flush(&revs->diffopt);
469 return 0;
470}
471int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
473{
474 struct tree *tree;
475 struct rev_info revs;
476 int i;
477 struct cache_entry **dst;
478 struct cache_entry *last = NULL;
479 struct unpack_trees_options opts;
480 struct tree_desc t;
481 /*
483 * This is used by git-blame to run diff-cache internally;
484 * it potentially needs to repeatedly run this, so we will
485 * start by removing the higher order entries the last round
486 * left behind.
487 */
488 dst = active_cache;
489 for (i = 0; i < active_nr; i++) {
490 struct cache_entry *ce = active_cache[i];
491 if (ce_stage(ce)) {
492 if (last && !strcmp(ce->name, last->name))
493 continue;
494 cache_tree_invalidate_path(active_cache_tree,
495 ce->name);
496 last = ce;
497 ce->ce_flags |= CE_REMOVE;
498 }
499 *dst++ = ce;
500 }
501 active_nr = dst - active_cache;
502 init_revisions(&revs, NULL);
504 revs.prune_data = opt->paths;
505 tree = parse_tree_indirect(tree_sha1);
506 if (!tree)
507 die("bad tree object %s", sha1_to_hex(tree_sha1));
508 memset(&opts, 0, sizeof(opts));
510 opts.head_idx = 1;
511 opts.index_only = 1;
512 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
513 opts.merge = 1;
514 opts.fn = oneway_diff;
515 opts.unpack_data = &revs;
516 opts.src_index = &the_index;
517 opts.dst_index = &the_index;
518 init_tree_desc(&t, tree->buffer, tree->size);
520 if (unpack_trees(1, &t, &opts))
521 exit(128);
522 return 0;
523}
524int index_differs_from(const char *def, int diff_flags)
526{
527 struct rev_info rev;
528 struct setup_revision_opt opt;
529 init_revisions(&rev, NULL);
531 memset(&opt, 0, sizeof(opt));
532 opt.def = def;
533 setup_revisions(0, NULL, &rev, &opt);
534 DIFF_OPT_SET(&rev.diffopt, QUICK);
535 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
536 rev.diffopt.flags |= diff_flags;
537 run_diff_index(&rev, 1);
538 if (rev.pending.alloc)
539 free(rev.pending.objects);
540 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
541}