blame.c: Properly initialize strbuf after calling, textconv_object()
[git/dscho.git] / diff-lib.c
blob8b8978ae6d1b4d947952b7fe9ec9cea013aaa8c3
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"
16 * diff-files
20 * Has the work tree entity been removed?
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.
28 static int check_removed(const struct cache_entry *ce, struct stat *st)
30 if (lstat(ce->name, st) < 0) {
31 if (errno != ENOENT && errno != ENOTDIR)
32 return -1;
33 return 1;
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];
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.
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!
51 if (!S_ISGITLINK(ce->ce_mode) &&
52 resolve_gitlink_ref(ce->name, "HEAD", sub))
53 return 1;
55 return 0;
59 * Has a file changed or has a submodule new commits or a dirty work tree?
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).
66 static int match_stat_with_submodule(struct diff_options *diffopt,
67 struct cache_entry *ce, struct stat *st,
68 unsigned ce_option, unsigned *dirty_submodule)
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 && !DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
74 && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES))) {
75 *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
77 return changed;
80 int run_diff_files(struct rev_info *revs, unsigned int option)
82 int entries, i;
83 int diff_unmerged_stage = revs->max_count;
84 int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
85 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
86 ? CE_MATCH_RACY_IS_DIRTY : 0);
88 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
90 if (diff_unmerged_stage < 0)
91 diff_unmerged_stage = 2;
92 entries = active_nr;
93 for (i = 0; i < entries; i++) {
94 struct stat st;
95 unsigned int oldmode, newmode;
96 struct cache_entry *ce = active_cache[i];
97 int changed;
98 unsigned dirty_submodule = 0;
100 if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
101 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
102 break;
104 if (!ce_path_match(ce, revs->prune_data))
105 continue;
107 if (ce_stage(ce)) {
108 struct combine_diff_path *dpath;
109 int num_compare_stages = 0;
110 size_t path_len;
112 path_len = ce_namelen(ce);
114 dpath = xmalloc(combine_diff_path_size(5, path_len));
115 dpath->path = (char *) &(dpath->parent[5]);
117 dpath->next = NULL;
118 dpath->len = path_len;
119 memcpy(dpath->path, ce->name, path_len);
120 dpath->path[path_len] = '\0';
121 hashclr(dpath->sha1);
122 memset(&(dpath->parent[0]), 0,
123 sizeof(struct combine_diff_parent)*5);
125 changed = check_removed(ce, &st);
126 if (!changed)
127 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
128 else {
129 if (changed < 0) {
130 perror(ce->name);
131 continue;
133 if (silent_on_removed)
134 continue;
137 while (i < entries) {
138 struct cache_entry *nce = active_cache[i];
139 int stage;
141 if (strcmp(ce->name, nce->name))
142 break;
144 /* Stage #2 (ours) is the first parent,
145 * stage #3 (theirs) is the second.
147 stage = ce_stage(nce);
148 if (2 <= stage) {
149 int mode = nce->ce_mode;
150 num_compare_stages++;
151 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
152 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
153 dpath->parent[stage-2].status =
154 DIFF_STATUS_MODIFIED;
157 /* diff against the proper unmerged stage */
158 if (stage == diff_unmerged_stage)
159 ce = nce;
160 i++;
163 * Compensate for loop update
165 i--;
167 if (revs->combine_merges && num_compare_stages == 2) {
168 show_combined_diff(dpath, 2,
169 revs->dense_combined_merges,
170 revs);
171 free(dpath);
172 continue;
174 free(dpath);
175 dpath = NULL;
178 * Show the diff for the 'ce' if we found the one
179 * from the desired stage.
181 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
182 if (ce_stage(ce) != diff_unmerged_stage)
183 continue;
186 if (ce_uptodate(ce) || ce_skip_worktree(ce))
187 continue;
189 /* If CE_VALID is set, don't look at workdir for file removal */
190 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
191 if (changed) {
192 if (changed < 0) {
193 perror(ce->name);
194 continue;
196 if (silent_on_removed)
197 continue;
198 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
199 ce->sha1, ce->name, 0);
200 continue;
202 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
203 ce_option, &dirty_submodule);
204 if (!changed && !dirty_submodule) {
205 ce_mark_uptodate(ce);
206 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
207 continue;
209 oldmode = ce->ce_mode;
210 newmode = ce_mode_from_stat(ce, st.st_mode);
211 diff_change(&revs->diffopt, oldmode, newmode,
212 ce->sha1, (changed ? null_sha1 : ce->sha1),
213 ce->name, 0, dirty_submodule);
216 diffcore_std(&revs->diffopt);
217 diff_flush(&revs->diffopt);
218 return 0;
222 * diff-index
225 /* A file entry went away or appeared */
226 static void diff_index_show_file(struct rev_info *revs,
227 const char *prefix,
228 struct cache_entry *ce,
229 const unsigned char *sha1, unsigned int mode,
230 unsigned dirty_submodule)
232 diff_addremove(&revs->diffopt, prefix[0], mode,
233 sha1, ce->name, dirty_submodule);
236 static int get_stat_data(struct cache_entry *ce,
237 const unsigned char **sha1p,
238 unsigned int *modep,
239 int cached, int match_missing,
240 unsigned *dirty_submodule, struct diff_options *diffopt)
242 const unsigned char *sha1 = ce->sha1;
243 unsigned int mode = ce->ce_mode;
245 if (!cached && !ce_uptodate(ce)) {
246 int changed;
247 struct stat st;
248 changed = check_removed(ce, &st);
249 if (changed < 0)
250 return -1;
251 else if (changed) {
252 if (match_missing) {
253 *sha1p = sha1;
254 *modep = mode;
255 return 0;
257 return -1;
259 changed = match_stat_with_submodule(diffopt, ce, &st,
260 0, dirty_submodule);
261 if (changed) {
262 mode = ce_mode_from_stat(ce, st.st_mode);
263 sha1 = null_sha1;
267 *sha1p = sha1;
268 *modep = mode;
269 return 0;
272 static void show_new_file(struct rev_info *revs,
273 struct cache_entry *new,
274 int cached, int match_missing)
276 const unsigned char *sha1;
277 unsigned int mode;
278 unsigned dirty_submodule = 0;
281 * New file in the index: it might actually be different in
282 * the working copy.
284 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
285 &dirty_submodule, &revs->diffopt) < 0)
286 return;
288 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
291 static int show_modified(struct rev_info *revs,
292 struct cache_entry *old,
293 struct cache_entry *new,
294 int report_missing,
295 int cached, int match_missing)
297 unsigned int mode, oldmode;
298 const unsigned char *sha1;
299 unsigned dirty_submodule = 0;
301 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
302 &dirty_submodule, &revs->diffopt) < 0) {
303 if (report_missing)
304 diff_index_show_file(revs, "-", old,
305 old->sha1, old->ce_mode, 0);
306 return -1;
309 if (revs->combine_merges && !cached &&
310 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
311 struct combine_diff_path *p;
312 int pathlen = ce_namelen(new);
314 p = xmalloc(combine_diff_path_size(2, pathlen));
315 p->path = (char *) &p->parent[2];
316 p->next = NULL;
317 p->len = pathlen;
318 memcpy(p->path, new->name, pathlen);
319 p->path[pathlen] = 0;
320 p->mode = mode;
321 hashclr(p->sha1);
322 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
323 p->parent[0].status = DIFF_STATUS_MODIFIED;
324 p->parent[0].mode = new->ce_mode;
325 hashcpy(p->parent[0].sha1, new->sha1);
326 p->parent[1].status = DIFF_STATUS_MODIFIED;
327 p->parent[1].mode = old->ce_mode;
328 hashcpy(p->parent[1].sha1, old->sha1);
329 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
330 free(p);
331 return 0;
334 oldmode = old->ce_mode;
335 if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
336 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
337 return 0;
339 diff_change(&revs->diffopt, oldmode, mode,
340 old->sha1, sha1, old->name, 0, dirty_submodule);
341 return 0;
345 * This gets a mix of an existing index and a tree, one pathname entry
346 * at a time. The index entry may be a single stage-0 one, but it could
347 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
348 * give you the position and number of entries in the index).
350 static void do_oneway_diff(struct unpack_trees_options *o,
351 struct cache_entry *idx,
352 struct cache_entry *tree)
354 struct rev_info *revs = o->unpack_data;
355 int match_missing, cached;
357 /* if the entry is not checked out, don't examine work tree */
358 cached = o->index_only ||
359 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
361 * Backward compatibility wart - "diff-index -m" does
362 * not mean "do not ignore merges", but "match_missing".
364 * But with the revision flag parsing, that's found in
365 * "!revs->ignore_merges".
367 match_missing = !revs->ignore_merges;
369 if (cached && idx && ce_stage(idx)) {
370 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
371 idx->sha1);
372 return;
376 * Something added to the tree?
378 if (!tree) {
379 show_new_file(revs, idx, cached, match_missing);
380 return;
384 * Something removed from the tree?
386 if (!idx) {
387 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
388 return;
391 /* Show difference between old and new */
392 show_modified(revs, tree, idx, 1, cached, match_missing);
396 * The unpack_trees() interface is designed for merging, so
397 * the different source entries are designed primarily for
398 * the source trees, with the old index being really mainly
399 * used for being replaced by the result.
401 * For diffing, the index is more important, and we only have a
402 * single tree.
404 * We're supposed to advance o->pos to skip what we have already processed.
406 * This wrapper makes it all more readable, and takes care of all
407 * the fairly complex unpack_trees() semantic requirements, including
408 * the skipping, the path matching, the type conflict cases etc.
410 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
412 struct cache_entry *idx = src[0];
413 struct cache_entry *tree = src[1];
414 struct rev_info *revs = o->unpack_data;
417 * Unpack-trees generates a DF/conflict entry if
418 * there was a directory in the index and a tree
419 * in the tree. From a diff standpoint, that's a
420 * delete of the tree and a create of the file.
422 if (tree == o->df_conflict_entry)
423 tree = NULL;
425 if (ce_path_match(idx ? idx : tree, revs->prune_data))
426 do_oneway_diff(o, idx, tree);
428 return 0;
431 int run_diff_index(struct rev_info *revs, int cached)
433 struct object *ent;
434 struct tree *tree;
435 const char *tree_name;
436 struct unpack_trees_options opts;
437 struct tree_desc t;
439 ent = revs->pending.objects[0].item;
440 tree_name = revs->pending.objects[0].name;
441 tree = parse_tree_indirect(ent->sha1);
442 if (!tree)
443 return error("bad tree object %s", tree_name);
445 memset(&opts, 0, sizeof(opts));
446 opts.head_idx = 1;
447 opts.index_only = cached;
448 opts.diff_index_cached = (cached &&
449 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
450 opts.merge = 1;
451 opts.fn = oneway_diff;
452 opts.unpack_data = revs;
453 opts.src_index = &the_index;
454 opts.dst_index = NULL;
456 init_tree_desc(&t, tree->buffer, tree->size);
457 if (unpack_trees(1, &t, &opts))
458 exit(128);
460 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
461 diffcore_fix_diff_index(&revs->diffopt);
462 diffcore_std(&revs->diffopt);
463 diff_flush(&revs->diffopt);
464 return 0;
467 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
469 struct tree *tree;
470 struct rev_info revs;
471 int i;
472 struct cache_entry **dst;
473 struct cache_entry *last = NULL;
474 struct unpack_trees_options opts;
475 struct tree_desc t;
478 * This is used by git-blame to run diff-cache internally;
479 * it potentially needs to repeatedly run this, so we will
480 * start by removing the higher order entries the last round
481 * left behind.
483 dst = active_cache;
484 for (i = 0; i < active_nr; i++) {
485 struct cache_entry *ce = active_cache[i];
486 if (ce_stage(ce)) {
487 if (last && !strcmp(ce->name, last->name))
488 continue;
489 cache_tree_invalidate_path(active_cache_tree,
490 ce->name);
491 last = ce;
492 ce->ce_flags |= CE_REMOVE;
494 *dst++ = ce;
496 active_nr = dst - active_cache;
498 init_revisions(&revs, NULL);
499 revs.prune_data = opt->paths;
500 tree = parse_tree_indirect(tree_sha1);
501 if (!tree)
502 die("bad tree object %s", sha1_to_hex(tree_sha1));
504 memset(&opts, 0, sizeof(opts));
505 opts.head_idx = 1;
506 opts.index_only = 1;
507 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
508 opts.merge = 1;
509 opts.fn = oneway_diff;
510 opts.unpack_data = &revs;
511 opts.src_index = &the_index;
512 opts.dst_index = &the_index;
514 init_tree_desc(&t, tree->buffer, tree->size);
515 if (unpack_trees(1, &t, &opts))
516 exit(128);
517 return 0;
520 int index_differs_from(const char *def, int diff_flags)
522 struct rev_info rev;
523 struct setup_revision_opt opt;
525 init_revisions(&rev, NULL);
526 memset(&opt, 0, sizeof(opt));
527 opt.def = def;
528 setup_revisions(0, NULL, &rev, &opt);
529 DIFF_OPT_SET(&rev.diffopt, QUICK);
530 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
531 rev.diffopt.flags |= diff_flags;
532 run_diff_index(&rev, 1);
533 if (rev.pending.alloc)
534 free(rev.pending.objects);
535 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);