revert: use strbuf to refactor the code that writes the merge message
[git/dscho.git] / diff-lib.c
blobd7e13cb177a3c345eb076a9ffede87c6e6afa367
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;
58 int run_diff_files(struct rev_info *revs, unsigned int option)
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);
66 diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
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;
78 if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
79 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
80 break;
82 if (!ce_path_match(ce, revs->prune_data))
83 continue;
85 if (ce_stage(ce)) {
86 struct combine_diff_path *dpath;
87 int num_compare_stages = 0;
88 size_t path_len;
90 path_len = ce_namelen(ce);
92 dpath = xmalloc(combine_diff_path_size(5, path_len));
93 dpath->path = (char *) &(dpath->parent[5]);
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);
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;
111 if (silent_on_removed)
112 continue;
115 while (i < entries) {
116 struct cache_entry *nce = active_cache[i];
117 int stage;
119 if (strcmp(ce->name, nce->name))
120 break;
122 /* Stage #2 (ours) is the first parent,
123 * stage #3 (theirs) is the second.
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;
135 /* diff against the proper unmerged stage */
136 if (stage == diff_unmerged_stage)
137 ce = nce;
138 i++;
141 * Compensate for loop update
143 i--;
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;
152 free(dpath);
153 dpath = NULL;
156 * Show the diff for the 'ce' if we found the one
157 * from the desired stage.
159 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
160 if (ce_stage(ce) != diff_unmerged_stage)
161 continue;
164 if (ce_uptodate(ce) || ce_skip_worktree(ce))
165 continue;
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;
174 if (silent_on_removed)
175 continue;
176 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
177 ce->sha1, ce->name, 0);
178 continue;
180 changed = ce_match_stat(ce, &st, ce_option);
181 if (S_ISGITLINK(ce->ce_mode)
182 && !DIFF_OPT_TST(&revs->diffopt, IGNORE_SUBMODULES)
183 && (!changed || (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
184 && is_submodule_modified(ce->name)) {
185 changed = 1;
186 dirty_submodule = 1;
188 if (!changed) {
189 ce_mark_uptodate(ce);
190 if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
191 continue;
193 oldmode = ce->ce_mode;
194 newmode = ce_mode_from_stat(ce, st.st_mode);
195 diff_change(&revs->diffopt, oldmode, newmode,
196 ce->sha1, (changed ? null_sha1 : ce->sha1),
197 ce->name, 0, dirty_submodule);
200 diffcore_std(&revs->diffopt);
201 diff_flush(&revs->diffopt);
202 return 0;
206 * diff-index
209 /* A file entry went away or appeared */
210 static void diff_index_show_file(struct rev_info *revs,
211 const char *prefix,
212 struct cache_entry *ce,
213 const unsigned char *sha1, unsigned int mode,
214 unsigned dirty_submodule)
216 diff_addremove(&revs->diffopt, prefix[0], mode,
217 sha1, ce->name, dirty_submodule);
220 static int get_stat_data(struct cache_entry *ce,
221 const unsigned char **sha1p,
222 unsigned int *modep,
223 int cached, int match_missing,
224 unsigned *dirty_submodule, struct diff_options *diffopt)
226 const unsigned char *sha1 = ce->sha1;
227 unsigned int mode = ce->ce_mode;
229 if (!cached && !ce_uptodate(ce)) {
230 int changed;
231 struct stat st;
232 changed = check_removed(ce, &st);
233 if (changed < 0)
234 return -1;
235 else if (changed) {
236 if (match_missing) {
237 *sha1p = sha1;
238 *modep = mode;
239 return 0;
241 return -1;
243 changed = ce_match_stat(ce, &st, 0);
244 if (S_ISGITLINK(ce->ce_mode)
245 && !DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES)
246 && (!changed || (diffopt->output_format & DIFF_FORMAT_PATCH))
247 && is_submodule_modified(ce->name)) {
248 changed = 1;
249 *dirty_submodule = 1;
251 if (changed) {
252 mode = ce_mode_from_stat(ce, st.st_mode);
253 sha1 = null_sha1;
257 *sha1p = sha1;
258 *modep = mode;
259 return 0;
262 static void show_new_file(struct rev_info *revs,
263 struct cache_entry *new,
264 int cached, int match_missing)
266 const unsigned char *sha1;
267 unsigned int mode;
268 unsigned dirty_submodule = 0;
271 * New file in the index: it might actually be different in
272 * the working copy.
274 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
275 &dirty_submodule, &revs->diffopt) < 0)
276 return;
278 diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
281 static int show_modified(struct rev_info *revs,
282 struct cache_entry *old,
283 struct cache_entry *new,
284 int report_missing,
285 int cached, int match_missing)
287 unsigned int mode, oldmode;
288 const unsigned char *sha1;
289 unsigned dirty_submodule = 0;
291 if (get_stat_data(new, &sha1, &mode, cached, match_missing,
292 &dirty_submodule, &revs->diffopt) < 0) {
293 if (report_missing)
294 diff_index_show_file(revs, "-", old,
295 old->sha1, old->ce_mode, 0);
296 return -1;
299 if (revs->combine_merges && !cached &&
300 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
301 struct combine_diff_path *p;
302 int pathlen = ce_namelen(new);
304 p = xmalloc(combine_diff_path_size(2, pathlen));
305 p->path = (char *) &p->parent[2];
306 p->next = NULL;
307 p->len = pathlen;
308 memcpy(p->path, new->name, pathlen);
309 p->path[pathlen] = 0;
310 p->mode = mode;
311 hashclr(p->sha1);
312 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
313 p->parent[0].status = DIFF_STATUS_MODIFIED;
314 p->parent[0].mode = new->ce_mode;
315 hashcpy(p->parent[0].sha1, new->sha1);
316 p->parent[1].status = DIFF_STATUS_MODIFIED;
317 p->parent[1].mode = old->ce_mode;
318 hashcpy(p->parent[1].sha1, old->sha1);
319 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
320 free(p);
321 return 0;
324 oldmode = old->ce_mode;
325 if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
326 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
327 return 0;
329 diff_change(&revs->diffopt, oldmode, mode,
330 old->sha1, sha1, old->name, 0, dirty_submodule);
331 return 0;
335 * This gets a mix of an existing index and a tree, one pathname entry
336 * at a time. The index entry may be a single stage-0 one, but it could
337 * also be multiple unmerged entries (in which case idx_pos/idx_nr will
338 * give you the position and number of entries in the index).
340 static void do_oneway_diff(struct unpack_trees_options *o,
341 struct cache_entry *idx,
342 struct cache_entry *tree)
344 struct rev_info *revs = o->unpack_data;
345 int match_missing, cached;
347 /* if the entry is not checked out, don't examine work tree */
348 cached = o->index_only ||
349 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
351 * Backward compatibility wart - "diff-index -m" does
352 * not mean "do not ignore merges", but "match_missing".
354 * But with the revision flag parsing, that's found in
355 * "!revs->ignore_merges".
357 match_missing = !revs->ignore_merges;
359 if (cached && idx && ce_stage(idx)) {
360 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
361 idx->sha1);
362 return;
366 * Something added to the tree?
368 if (!tree) {
369 show_new_file(revs, idx, cached, match_missing);
370 return;
374 * Something removed from the tree?
376 if (!idx) {
377 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
378 return;
381 /* Show difference between old and new */
382 show_modified(revs, tree, idx, 1, cached, match_missing);
386 * The unpack_trees() interface is designed for merging, so
387 * the different source entries are designed primarily for
388 * the source trees, with the old index being really mainly
389 * used for being replaced by the result.
391 * For diffing, the index is more important, and we only have a
392 * single tree.
394 * We're supposed to advance o->pos to skip what we have already processed.
396 * This wrapper makes it all more readable, and takes care of all
397 * the fairly complex unpack_trees() semantic requirements, including
398 * the skipping, the path matching, the type conflict cases etc.
400 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
402 struct cache_entry *idx = src[0];
403 struct cache_entry *tree = src[1];
404 struct rev_info *revs = o->unpack_data;
407 * Unpack-trees generates a DF/conflict entry if
408 * there was a directory in the index and a tree
409 * in the tree. From a diff standpoint, that's a
410 * delete of the tree and a create of the file.
412 if (tree == o->df_conflict_entry)
413 tree = NULL;
415 if (ce_path_match(idx ? idx : tree, revs->prune_data))
416 do_oneway_diff(o, idx, tree);
418 return 0;
421 int run_diff_index(struct rev_info *revs, int cached)
423 struct object *ent;
424 struct tree *tree;
425 const char *tree_name;
426 struct unpack_trees_options opts;
427 struct tree_desc t;
429 ent = revs->pending.objects[0].item;
430 tree_name = revs->pending.objects[0].name;
431 tree = parse_tree_indirect(ent->sha1);
432 if (!tree)
433 return error("bad tree object %s", tree_name);
435 memset(&opts, 0, sizeof(opts));
436 opts.head_idx = 1;
437 opts.index_only = cached;
438 opts.diff_index_cached = (cached &&
439 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
440 opts.merge = 1;
441 opts.fn = oneway_diff;
442 opts.unpack_data = revs;
443 opts.src_index = &the_index;
444 opts.dst_index = NULL;
446 init_tree_desc(&t, tree->buffer, tree->size);
447 if (unpack_trees(1, &t, &opts))
448 exit(128);
450 diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
451 diffcore_fix_diff_index(&revs->diffopt);
452 diffcore_std(&revs->diffopt);
453 diff_flush(&revs->diffopt);
454 return 0;
457 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
459 struct tree *tree;
460 struct rev_info revs;
461 int i;
462 struct cache_entry **dst;
463 struct cache_entry *last = NULL;
464 struct unpack_trees_options opts;
465 struct tree_desc t;
468 * This is used by git-blame to run diff-cache internally;
469 * it potentially needs to repeatedly run this, so we will
470 * start by removing the higher order entries the last round
471 * left behind.
473 dst = active_cache;
474 for (i = 0; i < active_nr; i++) {
475 struct cache_entry *ce = active_cache[i];
476 if (ce_stage(ce)) {
477 if (last && !strcmp(ce->name, last->name))
478 continue;
479 cache_tree_invalidate_path(active_cache_tree,
480 ce->name);
481 last = ce;
482 ce->ce_flags |= CE_REMOVE;
484 *dst++ = ce;
486 active_nr = dst - active_cache;
488 init_revisions(&revs, NULL);
489 revs.prune_data = opt->paths;
490 tree = parse_tree_indirect(tree_sha1);
491 if (!tree)
492 die("bad tree object %s", sha1_to_hex(tree_sha1));
494 memset(&opts, 0, sizeof(opts));
495 opts.head_idx = 1;
496 opts.index_only = 1;
497 opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
498 opts.merge = 1;
499 opts.fn = oneway_diff;
500 opts.unpack_data = &revs;
501 opts.src_index = &the_index;
502 opts.dst_index = &the_index;
504 init_tree_desc(&t, tree->buffer, tree->size);
505 if (unpack_trees(1, &t, &opts))
506 exit(128);
507 return 0;
510 int index_differs_from(const char *def, int diff_flags)
512 struct rev_info rev;
514 init_revisions(&rev, NULL);
515 setup_revisions(0, NULL, &rev, def);
516 DIFF_OPT_SET(&rev.diffopt, QUICK);
517 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
518 rev.diffopt.flags |= diff_flags;
519 run_diff_index(&rev, 1);
520 if (rev.pending.alloc)
521 free(rev.pending.objects);
522 return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);