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 && !DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES)
73 && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES))) {
74 *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
75 }
76 return changed;
77}
78int run_diff_files(struct rev_info *revs, unsigned int option)
80{
81 int entries, i;
82 int diff_unmerged_stage = revs->max_count;
83 int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
84 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
85 ? CE_MATCH_RACY_IS_DIRTY : 0);
86 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
88 if (diff_unmerged_stage < 0)
90 diff_unmerged_stage = 2;
91 entries = active_nr;
92 for (i = 0; i < entries; i++) {
93 struct stat st;
94 unsigned int oldmode, newmode;
95 struct cache_entry *ce = active_cache[i];
96 int changed;
97 unsigned dirty_submodule = 0;
98 if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
100 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
101 break;
102 if (!ce_path_match(ce, revs->prune_data))
104 continue;
105 if (ce_stage(ce)) {
107 struct combine_diff_path *dpath;
108 int num_compare_stages = 0;
109 size_t path_len;
110 path_len = ce_namelen(ce);
112 dpath = xmalloc(combine_diff_path_size(5, path_len));
114 dpath->path = (char *) &(dpath->parent[5]);
115 dpath->next = NULL;
117 dpath->len = path_len;
118 memcpy(dpath->path, ce->name, path_len);
119 dpath->path[path_len] = '\0';
120 hashclr(dpath->sha1);
121 memset(&(dpath->parent[0]), 0,
122 sizeof(struct combine_diff_parent)*5);
123 changed = check_removed(ce, &st);
125 if (!changed)
126 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
127 else {
128 if (changed < 0) {
129 perror(ce->name);
130 continue;
131 }
132 if (silent_on_removed)
133 continue;
134 }
135 while (i < entries) {
137 struct cache_entry *nce = active_cache[i];
138 int stage;
139 if (strcmp(ce->name, nce->name))
141 break;
142 /* Stage #2 (ours) is the first parent,
144 * stage #3 (theirs) is the second.
145 */
146 stage = ce_stage(nce);
147 if (2 <= stage) {
148 int mode = nce->ce_mode;
149 num_compare_stages++;
150 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
151 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
152 dpath->parent[stage-2].status =
153 DIFF_STATUS_MODIFIED;
154 }
155 /* diff against the proper unmerged stage */
157 if (stage == diff_unmerged_stage)
158 ce = nce;
159 i++;
160 }
161 /*
162 * Compensate for loop update
163 */
164 i--;
165 if (revs->combine_merges && num_compare_stages == 2) {
167 show_combined_diff(dpath, 2,
168 revs->dense_combined_merges,
169 revs);
170 free(dpath);
171 continue;
172 }
173 free(dpath);
174 dpath = NULL;
175 /*
177 * Show the diff for the 'ce' if we found the one
178 * from the desired stage.
179 */
180 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
181 if (ce_stage(ce) != diff_unmerged_stage)
182 continue;
183 }
184 if (ce_uptodate(ce) || ce_skip_worktree(ce))
186 continue;
187 /* If CE_VALID is set, don't look at workdir for file removal */
189 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
190 if (changed) {
191 if (changed < 0) {
192 perror(ce->name);
193 continue;
194 }
195 if (silent_on_removed)
196 continue;
197 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
198 ce->sha1, ce->name, 0);
199 continue;
200 }
201 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
202 ce_option, &dirty_submodule);
203 if (!changed && !dirty_submodule) {
204 ce_mark_uptodate(ce);
205 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
206 continue;
207 }
208 oldmode = ce->ce_mode;
209 newmode = ce_mode_from_stat(ce, st.st_mode);
210 diff_change(&revs->diffopt, oldmode, newmode,
211 ce->sha1, (changed ? null_sha1 : ce->sha1),
212 ce->name, 0, dirty_submodule);
213 }
215 diffcore_std(&revs->diffopt);
216 diff_flush(&revs->diffopt);
217 return 0;
218}
219/*
221 * diff-index
222 */
223/* A file entry went away or appeared */
225static void diff_index_show_file(struct rev_info *revs,
226 const char *prefix,
227 struct cache_entry *ce,
228 const unsigned char *sha1, unsigned int mode,
229 unsigned dirty_submodule)
230{
231 diff_addremove(&revs->diffopt, prefix[0], mode,
232 sha1, ce->name, dirty_submodule);
233}
234static int get_stat_data(struct cache_entry *ce,
236 const unsigned char **sha1p,
237 unsigned int *modep,
238 int cached, int match_missing,
239 unsigned *dirty_submodule, struct diff_options *diffopt)
240{
241 const unsigned char *sha1 = ce->sha1;
242 unsigned int mode = ce->ce_mode;
243 if (!cached && !ce_uptodate(ce)) {
245 int changed;
246 struct stat st;
247 changed = check_removed(ce, &st);
248 if (changed < 0)
249 return -1;
250 else if (changed) {
251 if (match_missing) {
252 *sha1p = sha1;
253 *modep = mode;
254 return 0;
255 }
256 return -1;
257 }
258 changed = match_stat_with_submodule(diffopt, ce, &st,
259 0, dirty_submodule);
260 if (changed) {
261 mode = ce_mode_from_stat(ce, st.st_mode);
262 sha1 = null_sha1;
263 }
264 }
265 *sha1p = sha1;
267 *modep = mode;
268 return 0;
269}
270static void show_new_file(struct rev_info *revs,
272 struct cache_entry *new,
273 int cached, int match_missing)
274{
275 const unsigned char *sha1;
276 unsigned int mode;
277 unsigned dirty_submodule = 0;
278 /*
280 * New file in the index: it might actually be different in
281 * the working copy.
282 */
283 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
284 &dirty_submodule, &revs->diffopt) < 0)
285 return;
286 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
288}
289static int show_modified(struct rev_info *revs,
291 struct cache_entry *old,
292 struct cache_entry *new,
293 int report_missing,
294 int cached, int match_missing)
295{
296 unsigned int mode, oldmode;
297 const unsigned char *sha1;
298 unsigned dirty_submodule = 0;
299 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
301 &dirty_submodule, &revs->diffopt) < 0) {
302 if (report_missing)
303 diff_index_show_file(revs, "-", old,
304 old->sha1, old->ce_mode, 0);
305 return -1;
306 }
307 if (revs->combine_merges && !cached &&
309 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
310 struct combine_diff_path *p;
311 int pathlen = ce_namelen(new);
312 p = xmalloc(combine_diff_path_size(2, pathlen));
314 p->path = (char *) &p->parent[2];
315 p->next = NULL;
316 p->len = pathlen;
317 memcpy(p->path, new->name, pathlen);
318 p->path[pathlen] = 0;
319 p->mode = mode;
320 hashclr(p->sha1);
321 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
322 p->parent[0].status = DIFF_STATUS_MODIFIED;
323 p->parent[0].mode = new->ce_mode;
324 hashcpy(p->parent[0].sha1, new->sha1);
325 p->parent[1].status = DIFF_STATUS_MODIFIED;
326 p->parent[1].mode = old->ce_mode;
327 hashcpy(p->parent[1].sha1, old->sha1);
328 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
329 free(p);
330 return 0;
331 }
332 oldmode = old->ce_mode;
334 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
335 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
336 return 0;
337 diff_change(&revs->diffopt, oldmode, mode,
339 old->sha1, sha1, old->name, 0, dirty_submodule);
340 return 0;
341}
342/*
344 * This gets a mix of an existing index and a tree, one pathname entry
345 * at a time. The index entry may be a single stage-0 one, but it could
346 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
347 * give you the position and number of entries in the index).
348 */
349static void do_oneway_diff(struct unpack_trees_options *o,
350 struct cache_entry *idx,
351 struct cache_entry *tree)
352{
353 struct rev_info *revs = o->unpack_data;
354 int match_missing, cached;
355 /* if the entry is not checked out, don't examine work tree */
357 cached = o->index_only ||
358 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
359 /*
360 * Backward compatibility wart - "diff-index -m" does
361 * not mean "do not ignore merges", but "match_missing".
362 *
363 * But with the revision flag parsing, that's found in
364 * "!revs->ignore_merges".
365 */
366 match_missing = !revs->ignore_merges;
367 if (cached && idx && ce_stage(idx)) {
369 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
370 idx->sha1);
371 return;
372 }
373 /*
375 * Something added to the tree?
376 */
377 if (!tree) {
378 show_new_file(revs, idx, cached, match_missing);
379 return;
380 }
381 /*
383 * Something removed from the tree?
384 */
385 if (!idx) {
386 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
387 return;
388 }
389 /* Show difference between old and new */
391 show_modified(revs, tree, idx, 1, cached, match_missing);
392}
393/*
395 * The unpack_trees() interface is designed for merging, so
396 * the different source entries are designed primarily for
397 * the source trees, with the old index being really mainly
398 * used for being replaced by the result.
399 *
400 * For diffing, the index is more important, and we only have a
401 * single tree.
402 *
403 * We're supposed to advance o->pos to skip what we have already processed.
404 *
405 * This wrapper makes it all more readable, and takes care of all
406 * the fairly complex unpack_trees() semantic requirements, including
407 * the skipping, the path matching, the type conflict cases etc.
408 */
409static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
410{
411 struct cache_entry *idx = src[0];
412 struct cache_entry *tree = src[1];
413 struct rev_info *revs = o->unpack_data;
414 /*
416 * Unpack-trees generates a DF/conflict entry if
417 * there was a directory in the index and a tree
418 * in the tree. From a diff standpoint, that's a
419 * delete of the tree and a create of the file.
420 */
421 if (tree == o->df_conflict_entry)
422 tree = NULL;
423 if (ce_path_match(idx ? idx : tree, revs->prune_data))
425 do_oneway_diff(o, idx, tree);
426 return 0;
428}
429int run_diff_index(struct rev_info *revs, int cached)
431{
432 struct object *ent;
433 struct tree *tree;
434 const char *tree_name;
435 struct unpack_trees_options opts;
436 struct tree_desc t;
437 ent = revs->pending.objects[0].item;
439 tree_name = revs->pending.objects[0].name;
440 tree = parse_tree_indirect(ent->sha1);
441 if (!tree)
442 return error("bad tree object %s", tree_name);
443 memset(&opts, 0, sizeof(opts));
445 opts.head_idx = 1;
446 opts.index_only = cached;
447 opts.diff_index_cached = (cached &&
448 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
449 opts.merge = 1;
450 opts.fn = oneway_diff;
451 opts.unpack_data = revs;
452 opts.src_index = &the_index;
453 opts.dst_index = NULL;
454 init_tree_desc(&t, tree->buffer, tree->size);
456 if (unpack_trees(1, &t, &opts))
457 exit(128);
458 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
460 diffcore_fix_diff_index(&revs->diffopt);
461 diffcore_std(&revs->diffopt);
462 diff_flush(&revs->diffopt);
463 return 0;
464}
465int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
467{
468 struct tree *tree;
469 struct rev_info revs;
470 int i;
471 struct cache_entry **dst;
472 struct cache_entry *last = NULL;
473 struct unpack_trees_options opts;
474 struct tree_desc t;
475 /*
477 * This is used by git-blame to run diff-cache internally;
478 * it potentially needs to repeatedly run this, so we will
479 * start by removing the higher order entries the last round
480 * left behind.
481 */
482 dst = active_cache;
483 for (i = 0; i < active_nr; i++) {
484 struct cache_entry *ce = active_cache[i];
485 if (ce_stage(ce)) {
486 if (last && !strcmp(ce->name, last->name))
487 continue;
488 cache_tree_invalidate_path(active_cache_tree,
489 ce->name);
490 last = ce;
491 ce->ce_flags |= CE_REMOVE;
492 }
493 *dst++ = ce;
494 }
495 active_nr = dst - active_cache;
496 init_revisions(&revs, NULL);
498 revs.prune_data = opt->paths;
499 tree = parse_tree_indirect(tree_sha1);
500 if (!tree)
501 die("bad tree object %s", sha1_to_hex(tree_sha1));
502 memset(&opts, 0, sizeof(opts));
504 opts.head_idx = 1;
505 opts.index_only = 1;
506 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
507 opts.merge = 1;
508 opts.fn = oneway_diff;
509 opts.unpack_data = &revs;
510 opts.src_index = &the_index;
511 opts.dst_index = &the_index;
512 init_tree_desc(&t, tree->buffer, tree->size);
514 if (unpack_trees(1, &t, &opts))
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}