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
15/*
16 * diff-files
17 */
18
19/*
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
40 /*
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
58int run_diff_files(struct rev_info *revs, unsigned int option)
59{
60 int entries, i;
61 int diff_unmerged_stage = revs->max_count;
62 int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
63 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
64 ? CE_MATCH_RACY_IS_DIRTY : 0);
65
66 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
67
68 if (diff_unmerged_stage < 0)
69 diff_unmerged_stage = 2;
70 entries = active_nr;
71 for (i = 0; i < entries; i++) {
72 struct stat st;
73 unsigned int oldmode, newmode;
74 struct cache_entry *ce = active_cache[i];
75 int changed;
76 unsigned dirty_submodule = 0;
77
78 if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
79 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
80 break;
81
82 if (!ce_path_match(ce, revs->prune_data))
83 continue;
84
85 if (ce_stage(ce)) {
86 struct combine_diff_path *dpath;
87 int num_compare_stages = 0;
88 size_t path_len;
89
90 path_len = ce_namelen(ce);
91
92 dpath = xmalloc(combine_diff_path_size(5, path_len));
93 dpath->path = (char *) &(dpath->parent[5]);
94
95 dpath->next = NULL;
96 dpath->len = path_len;
97 memcpy(dpath->path, ce->name, path_len);
98 dpath->path[path_len] = '\0';
99 hashclr(dpath->sha1);
100 memset(&(dpath->parent[0]), 0,
101 sizeof(struct combine_diff_parent)*5);
102
103 changed = check_removed(ce, &st);
104 if (!changed)
105 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
106 else {
107 if (changed < 0) {
108 perror(ce->name);
109 continue;
110 }
111 if (silent_on_removed)
112 continue;
113 }
114
115 while (i < entries) {
116 struct cache_entry *nce = active_cache[i];
117 int stage;
118
119 if (strcmp(ce->name, nce->name))
120 break;
121
122 /* Stage #2 (ours) is the first parent,
123 * stage #3 (theirs) is the second.
124 */
125 stage = ce_stage(nce);
126 if (2 <= stage) {
127 int mode = nce->ce_mode;
128 num_compare_stages++;
129 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
130 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
131 dpath->parent[stage-2].status =
132 DIFF_STATUS_MODIFIED;
133 }
134
135 /* diff against the proper unmerged stage */
136 if (stage == diff_unmerged_stage)
137 ce = nce;
138 i++;
139 }
140 /*
141 * Compensate for loop update
142 */
143 i--;
144
145 if (revs->combine_merges && num_compare_stages == 2) {
146 show_combined_diff(dpath, 2,
147 revs->dense_combined_merges,
148 revs);
149 free(dpath);
150 continue;
151 }
152 free(dpath);
153 dpath = NULL;
154
155 /*
156 * Show the diff for the 'ce' if we found the one
157 * from the desired stage.
158 */
159 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
160 if (ce_stage(ce) != diff_unmerged_stage)
161 continue;
162 }
163
164 if ((ce_uptodate(ce) && !S_ISGITLINK(ce->ce_mode)) || ce_skip_worktree(ce))
165 continue;
166
167 /* If CE_VALID is set, don't look at workdir for file removal */
168 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
169 if (changed) {
170 if (changed < 0) {
171 perror(ce->name);
172 continue;
173 }
174 if (silent_on_removed)
175 continue;
176 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
177 ce->sha1, ce->name, 0);
178 continue;
179 }
180 changed = ce_match_stat(ce, &st, ce_option);
181 if (S_ISGITLINK(ce->ce_mode)
182 && (!changed || (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
183 && is_submodule_modified(ce->name)) {
184 changed = 1;
185 dirty_submodule = 1;
186 }
187 if (!changed) {
188 ce_mark_uptodate(ce);
189 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
190 continue;
191 }
192 oldmode = ce->ce_mode;
193 newmode = ce_mode_from_stat(ce, st.st_mode);
194 diff_change(&revs->diffopt, oldmode, newmode,
195 ce->sha1, (changed ? null_sha1 : ce->sha1),
196 ce->name, 0, dirty_submodule);
197
198 }
199 diffcore_std(&revs->diffopt);
200 diff_flush(&revs->diffopt);
201 return 0;
202}
203
204/*
205 * diff-index
206 */
207
208/* A file entry went away or appeared */
209static void diff_index_show_file(struct rev_info *revs,
210 const char *prefix,
211 struct cache_entry *ce,
212 const unsigned char *sha1, unsigned int mode,
213 unsigned dirty_submodule)
214{
215 diff_addremove(&revs->diffopt, prefix[0], mode,
216 sha1, ce->name, dirty_submodule);
217}
218
219static int get_stat_data(struct cache_entry *ce,
220 const unsigned char **sha1p,
221 unsigned int *modep,
222 int cached, int match_missing,
223 unsigned *dirty_submodule, int output_format)
224{
225 const unsigned char *sha1 = ce->sha1;
226 unsigned int mode = ce->ce_mode;
227
228 if (!cached && !ce_uptodate(ce)) {
229 int changed;
230 struct stat st;
231 changed = check_removed(ce, &st);
232 if (changed < 0)
233 return -1;
234 else if (changed) {
235 if (match_missing) {
236 *sha1p = sha1;
237 *modep = mode;
238 return 0;
239 }
240 return -1;
241 }
242 changed = ce_match_stat(ce, &st, 0);
243 if (S_ISGITLINK(ce->ce_mode)
244 && (!changed || (output_format & DIFF_FORMAT_PATCH))
245 && is_submodule_modified(ce->name)) {
246 changed = 1;
247 *dirty_submodule = 1;
248 }
249 if (changed) {
250 mode = ce_mode_from_stat(ce, st.st_mode);
251 sha1 = null_sha1;
252 }
253 }
254
255 *sha1p = sha1;
256 *modep = mode;
257 return 0;
258}
259
260static void show_new_file(struct rev_info *revs,
261 struct cache_entry *new,
262 int cached, int match_missing)
263{
264 const unsigned char *sha1;
265 unsigned int mode;
266 unsigned dirty_submodule = 0;
267
268 /*
269 * New file in the index: it might actually be different in
270 * the working copy.
271 */
272 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
273 &dirty_submodule, revs->diffopt.output_format) < 0)
274 return;
275
276 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
277}
278
279static int show_modified(struct rev_info *revs,
280 struct cache_entry *old,
281 struct cache_entry *new,
282 int report_missing,
283 int cached, int match_missing)
284{
285 unsigned int mode, oldmode;
286 const unsigned char *sha1;
287 unsigned dirty_submodule = 0;
288
289 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
290 &dirty_submodule, revs->diffopt.output_format) < 0) {
291 if (report_missing)
292 diff_index_show_file(revs, "-", old,
293 old->sha1, old->ce_mode, 0);
294 return -1;
295 }
296
297 if (revs->combine_merges && !cached &&
298 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
299 struct combine_diff_path *p;
300 int pathlen = ce_namelen(new);
301
302 p = xmalloc(combine_diff_path_size(2, pathlen));
303 p->path = (char *) &p->parent[2];
304 p->next = NULL;
305 p->len = pathlen;
306 memcpy(p->path, new->name, pathlen);
307 p->path[pathlen] = 0;
308 p->mode = mode;
309 hashclr(p->sha1);
310 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
311 p->parent[0].status = DIFF_STATUS_MODIFIED;
312 p->parent[0].mode = new->ce_mode;
313 hashcpy(p->parent[0].sha1, new->sha1);
314 p->parent[1].status = DIFF_STATUS_MODIFIED;
315 p->parent[1].mode = old->ce_mode;
316 hashcpy(p->parent[1].sha1, old->sha1);
317 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
318 free(p);
319 return 0;
320 }
321
322 oldmode = old->ce_mode;
323 if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
324 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
325 return 0;
326
327 diff_change(&revs->diffopt, oldmode, mode,
328 old->sha1, sha1, old->name, 0, dirty_submodule);
329 return 0;
330}
331
332/*
333 * This gets a mix of an existing index and a tree, one pathname entry
334 * at a time. The index entry may be a single stage-0 one, but it could
335 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
336 * give you the position and number of entries in the index).
337 */
338static void do_oneway_diff(struct unpack_trees_options *o,
339 struct cache_entry *idx,
340 struct cache_entry *tree)
341{
342 struct rev_info *revs = o->unpack_data;
343 int match_missing, cached;
344
345 /* if the entry is not checked out, don't examine work tree */
346 cached = o->index_only ||
347 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
348 /*
349 * Backward compatibility wart - "diff-index -m" does
350 * not mean "do not ignore merges", but "match_missing".
351 *
352 * But with the revision flag parsing, that's found in
353 * "!revs->ignore_merges".
354 */
355 match_missing = !revs->ignore_merges;
356
357 if (cached && idx && ce_stage(idx)) {
358 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
359 idx->sha1);
360 return;
361 }
362
363 /*
364 * Something added to the tree?
365 */
366 if (!tree) {
367 show_new_file(revs, idx, cached, match_missing);
368 return;
369 }
370
371 /*
372 * Something removed from the tree?
373 */
374 if (!idx) {
375 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
376 return;
377 }
378
379 /* Show difference between old and new */
380 show_modified(revs, tree, idx, 1, cached, match_missing);
381}
382
383/*
384 * The unpack_trees() interface is designed for merging, so
385 * the different source entries are designed primarily for
386 * the source trees, with the old index being really mainly
387 * used for being replaced by the result.
388 *
389 * For diffing, the index is more important, and we only have a
390 * single tree.
391 *
392 * We're supposed to advance o->pos to skip what we have already processed.
393 *
394 * This wrapper makes it all more readable, and takes care of all
395 * the fairly complex unpack_trees() semantic requirements, including
396 * the skipping, the path matching, the type conflict cases etc.
397 */
398static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
399{
400 struct cache_entry *idx = src[0];
401 struct cache_entry *tree = src[1];
402 struct rev_info *revs = o->unpack_data;
403
404 /*
405 * Unpack-trees generates a DF/conflict entry if
406 * there was a directory in the index and a tree
407 * in the tree. From a diff standpoint, that's a
408 * delete of the tree and a create of the file.
409 */
410 if (tree == o->df_conflict_entry)
411 tree = NULL;
412
413 if (ce_path_match(idx ? idx : tree, revs->prune_data))
414 do_oneway_diff(o, idx, tree);
415
416 return 0;
417}
418
419int run_diff_index(struct rev_info *revs, int cached)
420{
421 struct object *ent;
422 struct tree *tree;
423 const char *tree_name;
424 struct unpack_trees_options opts;
425 struct tree_desc t;
426
427 ent = revs->pending.objects[0].item;
428 tree_name = revs->pending.objects[0].name;
429 tree = parse_tree_indirect(ent->sha1);
430 if (!tree)
431 return error("bad tree object %s", tree_name);
432
433 memset(&opts, 0, sizeof(opts));
434 opts.head_idx = 1;
435 opts.index_only = cached;
436 opts.diff_index_cached = (cached &&
437 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
438 opts.merge = 1;
439 opts.fn = oneway_diff;
440 opts.unpack_data = revs;
441 opts.src_index = &the_index;
442 opts.dst_index = NULL;
443
444 init_tree_desc(&t, tree->buffer, tree->size);
445 if (unpack_trees(1, &t, &opts))
446 exit(128);
447
448 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
449 diffcore_fix_diff_index(&revs->diffopt);
450 diffcore_std(&revs->diffopt);
451 diff_flush(&revs->diffopt);
452 return 0;
453}
454
455int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
456{
457 struct tree *tree;
458 struct rev_info revs;
459 int i;
460 struct cache_entry **dst;
461 struct cache_entry *last = NULL;
462 struct unpack_trees_options opts;
463 struct tree_desc t;
464
465 /*
466 * This is used by git-blame to run diff-cache internally;
467 * it potentially needs to repeatedly run this, so we will
468 * start by removing the higher order entries the last round
469 * left behind.
470 */
471 dst = active_cache;
472 for (i = 0; i < active_nr; i++) {
473 struct cache_entry *ce = active_cache[i];
474 if (ce_stage(ce)) {
475 if (last && !strcmp(ce->name, last->name))
476 continue;
477 cache_tree_invalidate_path(active_cache_tree,
478 ce->name);
479 last = ce;
480 ce->ce_flags |= CE_REMOVE;
481 }
482 *dst++ = ce;
483 }
484 active_nr = dst - active_cache;
485
486 init_revisions(&revs, NULL);
487 revs.prune_data = opt->paths;
488 tree = parse_tree_indirect(tree_sha1);
489 if (!tree)
490 die("bad tree object %s", sha1_to_hex(tree_sha1));
491
492 memset(&opts, 0, sizeof(opts));
493 opts.head_idx = 1;
494 opts.index_only = 1;
495 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
496 opts.merge = 1;
497 opts.fn = oneway_diff;
498 opts.unpack_data = &revs;
499 opts.src_index = &the_index;
500 opts.dst_index = &the_index;
501
502 init_tree_desc(&t, tree->buffer, tree->size);
503 if (unpack_trees(1, &t, &opts))
504 exit(128);
505 return 0;
506}
507
508int index_differs_from(const char *def, int diff_flags)
509{
510 struct rev_info rev;
511
512 init_revisions(&rev, NULL);
513 setup_revisions(0, NULL, &rev, def);
514 DIFF_OPT_SET(&rev.diffopt, QUICK);
515 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
516 rev.diffopt.flags |= diff_flags;
517 run_diff_index(&rev, 1);
518 if (rev.pending.alloc)
519 free(rev.pending.objects);
520 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
521}