rerere: represent time duration in timestamp_t internally
[git] / diff-lib.c
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 #include "dir.h"
15
16 /*
17  * diff-files
18  */
19
20 /*
21  * Has the work tree entity been removed?
22  *
23  * Return 1 if it was removed from the work tree, 0 if an entity to be
24  * compared with the cache entry ce still exists (the latter includes
25  * the case where a directory that is not a submodule repository
26  * exists for ce that is a submodule -- it is a submodule that is not
27  * checked out).  Return negative for an error.
28  */
29 static int check_removed(const struct cache_entry *ce, struct stat *st)
30 {
31         if (lstat(ce->name, st) < 0) {
32                 if (!is_missing_file_error(errno))
33                         return -1;
34                 return 1;
35         }
36         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
37                 return 1;
38         if (S_ISDIR(st->st_mode)) {
39                 unsigned char sub[20];
40
41                 /*
42                  * If ce is already a gitlink, we can have a plain
43                  * directory (i.e. the submodule is not checked out),
44                  * or a checked out submodule.  Either case this is not
45                  * a case where something was removed from the work tree,
46                  * so we will return 0.
47                  *
48                  * Otherwise, if the directory is not a submodule
49                  * repository, that means ce which was a blob turned into
50                  * a directory --- the blob was removed!
51                  */
52                 if (!S_ISGITLINK(ce->ce_mode) &&
53                     resolve_gitlink_ref(ce->name, "HEAD", sub))
54                         return 1;
55         }
56         return 0;
57 }
58
59 /*
60  * Has a file changed or has a submodule new commits or a dirty work tree?
61  *
62  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
63  * option is set, the caller does not only want to know if a submodule is
64  * modified at all but wants to know all the conditions that are met (new
65  * commits, untracked content and/or modified content).
66  */
67 static int match_stat_with_submodule(struct diff_options *diffopt,
68                                      const struct cache_entry *ce,
69                                      struct stat *st, unsigned ce_option,
70                                      unsigned *dirty_submodule)
71 {
72         int changed = ce_match_stat(ce, st, ce_option);
73         if (S_ISGITLINK(ce->ce_mode)) {
74                 unsigned orig_flags = diffopt->flags;
75                 if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
76                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
77                 if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
78                         changed = 0;
79                 else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
80                     && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
81                         *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
82                 diffopt->flags = orig_flags;
83         }
84         return changed;
85 }
86
87 int run_diff_files(struct rev_info *revs, unsigned int option)
88 {
89         int entries, i;
90         int diff_unmerged_stage = revs->max_count;
91         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
92                               ? CE_MATCH_RACY_IS_DIRTY : 0);
93
94         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
95
96         if (diff_unmerged_stage < 0)
97                 diff_unmerged_stage = 2;
98         entries = active_nr;
99         for (i = 0; i < entries; i++) {
100                 unsigned int oldmode, newmode;
101                 struct cache_entry *ce = active_cache[i];
102                 int changed;
103                 unsigned dirty_submodule = 0;
104                 const struct object_id *old_oid, *new_oid;
105
106                 if (diff_can_quit_early(&revs->diffopt))
107                         break;
108
109                 if (!ce_path_match(ce, &revs->prune_data, NULL))
110                         continue;
111
112                 if (ce_stage(ce)) {
113                         struct combine_diff_path *dpath;
114                         struct diff_filepair *pair;
115                         unsigned int wt_mode = 0;
116                         int num_compare_stages = 0;
117                         size_t path_len;
118                         struct stat st;
119
120                         path_len = ce_namelen(ce);
121
122                         dpath = xmalloc(combine_diff_path_size(5, path_len));
123                         dpath->path = (char *) &(dpath->parent[5]);
124
125                         dpath->next = NULL;
126                         memcpy(dpath->path, ce->name, path_len);
127                         dpath->path[path_len] = '\0';
128                         oidclr(&dpath->oid);
129                         memset(&(dpath->parent[0]), 0,
130                                sizeof(struct combine_diff_parent)*5);
131
132                         changed = check_removed(ce, &st);
133                         if (!changed)
134                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
135                         else {
136                                 if (changed < 0) {
137                                         perror(ce->name);
138                                         continue;
139                                 }
140                                 wt_mode = 0;
141                         }
142                         dpath->mode = wt_mode;
143
144                         while (i < entries) {
145                                 struct cache_entry *nce = active_cache[i];
146                                 int stage;
147
148                                 if (strcmp(ce->name, nce->name))
149                                         break;
150
151                                 /* Stage #2 (ours) is the first parent,
152                                  * stage #3 (theirs) is the second.
153                                  */
154                                 stage = ce_stage(nce);
155                                 if (2 <= stage) {
156                                         int mode = nce->ce_mode;
157                                         num_compare_stages++;
158                                         oidcpy(&dpath->parent[stage - 2].oid,
159                                                &nce->oid);
160                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
161                                         dpath->parent[stage-2].status =
162                                                 DIFF_STATUS_MODIFIED;
163                                 }
164
165                                 /* diff against the proper unmerged stage */
166                                 if (stage == diff_unmerged_stage)
167                                         ce = nce;
168                                 i++;
169                         }
170                         /*
171                          * Compensate for loop update
172                          */
173                         i--;
174
175                         if (revs->combine_merges && num_compare_stages == 2) {
176                                 show_combined_diff(dpath, 2,
177                                                    revs->dense_combined_merges,
178                                                    revs);
179                                 free(dpath);
180                                 continue;
181                         }
182                         FREE_AND_NULL(dpath);
183
184                         /*
185                          * Show the diff for the 'ce' if we found the one
186                          * from the desired stage.
187                          */
188                         pair = diff_unmerge(&revs->diffopt, ce->name);
189                         if (wt_mode)
190                                 pair->two->mode = wt_mode;
191                         if (ce_stage(ce) != diff_unmerged_stage)
192                                 continue;
193                 }
194
195                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
196                         continue;
197
198                 /* If CE_VALID is set, don't look at workdir for file removal */
199                 if (ce->ce_flags & CE_VALID) {
200                         changed = 0;
201                         newmode = ce->ce_mode;
202                 } else {
203                         struct stat st;
204
205                         changed = check_removed(ce, &st);
206                         if (changed) {
207                                 if (changed < 0) {
208                                         perror(ce->name);
209                                         continue;
210                                 }
211                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
212                                                &ce->oid,
213                                                !is_null_oid(&ce->oid),
214                                                ce->name, 0);
215                                 continue;
216                         } else if (revs->diffopt.ita_invisible_in_index &&
217                                    ce_intent_to_add(ce)) {
218                                 diff_addremove(&revs->diffopt, '+', ce->ce_mode,
219                                                &empty_tree_oid, 0,
220                                                ce->name, 0);
221                                 continue;
222                         }
223
224                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
225                                                             ce_option, &dirty_submodule);
226                         newmode = ce_mode_from_stat(ce, st.st_mode);
227                 }
228
229                 if (!changed && !dirty_submodule) {
230                         ce_mark_uptodate(ce);
231                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
232                                 continue;
233                 }
234                 oldmode = ce->ce_mode;
235                 old_oid = &ce->oid;
236                 new_oid = changed ? &null_oid : &ce->oid;
237                 diff_change(&revs->diffopt, oldmode, newmode,
238                             old_oid, new_oid,
239                             !is_null_oid(old_oid),
240                             !is_null_oid(new_oid),
241                             ce->name, 0, dirty_submodule);
242
243         }
244         diffcore_std(&revs->diffopt);
245         diff_flush(&revs->diffopt);
246         return 0;
247 }
248
249 /*
250  * diff-index
251  */
252
253 /* A file entry went away or appeared */
254 static void diff_index_show_file(struct rev_info *revs,
255                                  const char *prefix,
256                                  const struct cache_entry *ce,
257                                  const struct object_id *oid, int oid_valid,
258                                  unsigned int mode,
259                                  unsigned dirty_submodule)
260 {
261         diff_addremove(&revs->diffopt, prefix[0], mode,
262                        oid, oid_valid, ce->name, dirty_submodule);
263 }
264
265 static int get_stat_data(const struct cache_entry *ce,
266                          const struct object_id **oidp,
267                          unsigned int *modep,
268                          int cached, int match_missing,
269                          unsigned *dirty_submodule, struct diff_options *diffopt)
270 {
271         const struct object_id *oid = &ce->oid;
272         unsigned int mode = ce->ce_mode;
273
274         if (!cached && !ce_uptodate(ce)) {
275                 int changed;
276                 struct stat st;
277                 changed = check_removed(ce, &st);
278                 if (changed < 0)
279                         return -1;
280                 else if (changed) {
281                         if (match_missing) {
282                                 *oidp = oid;
283                                 *modep = mode;
284                                 return 0;
285                         }
286                         return -1;
287                 }
288                 changed = match_stat_with_submodule(diffopt, ce, &st,
289                                                     0, dirty_submodule);
290                 if (changed) {
291                         mode = ce_mode_from_stat(ce, st.st_mode);
292                         oid = &null_oid;
293                 }
294         }
295
296         *oidp = oid;
297         *modep = mode;
298         return 0;
299 }
300
301 static void show_new_file(struct rev_info *revs,
302                           const struct cache_entry *new,
303                           int cached, int match_missing)
304 {
305         const struct object_id *oid;
306         unsigned int mode;
307         unsigned dirty_submodule = 0;
308
309         /*
310          * New file in the index: it might actually be different in
311          * the working tree.
312          */
313         if (get_stat_data(new, &oid, &mode, cached, match_missing,
314             &dirty_submodule, &revs->diffopt) < 0)
315                 return;
316
317         diff_index_show_file(revs, "+", new, oid, !is_null_oid(oid), mode, dirty_submodule);
318 }
319
320 static int show_modified(struct rev_info *revs,
321                          const struct cache_entry *old,
322                          const struct cache_entry *new,
323                          int report_missing,
324                          int cached, int match_missing)
325 {
326         unsigned int mode, oldmode;
327         const struct object_id *oid;
328         unsigned dirty_submodule = 0;
329
330         if (get_stat_data(new, &oid, &mode, cached, match_missing,
331                           &dirty_submodule, &revs->diffopt) < 0) {
332                 if (report_missing)
333                         diff_index_show_file(revs, "-", old,
334                                              &old->oid, 1, old->ce_mode,
335                                              0);
336                 return -1;
337         }
338
339         if (revs->combine_merges && !cached &&
340             (oidcmp(oid, &old->oid) || oidcmp(&old->oid, &new->oid))) {
341                 struct combine_diff_path *p;
342                 int pathlen = ce_namelen(new);
343
344                 p = xmalloc(combine_diff_path_size(2, pathlen));
345                 p->path = (char *) &p->parent[2];
346                 p->next = NULL;
347                 memcpy(p->path, new->name, pathlen);
348                 p->path[pathlen] = 0;
349                 p->mode = mode;
350                 oidclr(&p->oid);
351                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
352                 p->parent[0].status = DIFF_STATUS_MODIFIED;
353                 p->parent[0].mode = new->ce_mode;
354                 oidcpy(&p->parent[0].oid, &new->oid);
355                 p->parent[1].status = DIFF_STATUS_MODIFIED;
356                 p->parent[1].mode = old->ce_mode;
357                 oidcpy(&p->parent[1].oid, &old->oid);
358                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
359                 free(p);
360                 return 0;
361         }
362
363         oldmode = old->ce_mode;
364         if (mode == oldmode && !oidcmp(oid, &old->oid) && !dirty_submodule &&
365             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
366                 return 0;
367
368         diff_change(&revs->diffopt, oldmode, mode,
369                     &old->oid, oid, 1, !is_null_oid(oid),
370                     old->name, 0, dirty_submodule);
371         return 0;
372 }
373
374 /*
375  * This gets a mix of an existing index and a tree, one pathname entry
376  * at a time. The index entry may be a single stage-0 one, but it could
377  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
378  * give you the position and number of entries in the index).
379  */
380 static void do_oneway_diff(struct unpack_trees_options *o,
381                            const struct cache_entry *idx,
382                            const struct cache_entry *tree)
383 {
384         struct rev_info *revs = o->unpack_data;
385         int match_missing, cached;
386
387         /* i-t-a entries do not actually exist in the index */
388         if (revs->diffopt.ita_invisible_in_index &&
389             idx && ce_intent_to_add(idx)) {
390                 idx = NULL;
391                 if (!tree)
392                         return; /* nothing to diff.. */
393         }
394
395         /* if the entry is not checked out, don't examine work tree */
396         cached = o->index_only ||
397                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
398         /*
399          * Backward compatibility wart - "diff-index -m" does
400          * not mean "do not ignore merges", but "match_missing".
401          *
402          * But with the revision flag parsing, that's found in
403          * "!revs->ignore_merges".
404          */
405         match_missing = !revs->ignore_merges;
406
407         if (cached && idx && ce_stage(idx)) {
408                 struct diff_filepair *pair;
409                 pair = diff_unmerge(&revs->diffopt, idx->name);
410                 if (tree)
411                         fill_filespec(pair->one, &tree->oid, 1,
412                                       tree->ce_mode);
413                 return;
414         }
415
416         /*
417          * Something added to the tree?
418          */
419         if (!tree) {
420                 show_new_file(revs, idx, cached, match_missing);
421                 return;
422         }
423
424         /*
425          * Something removed from the tree?
426          */
427         if (!idx) {
428                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
429                                      tree->ce_mode, 0);
430                 return;
431         }
432
433         /* Show difference between old and new */
434         show_modified(revs, tree, idx, 1, cached, match_missing);
435 }
436
437 /*
438  * The unpack_trees() interface is designed for merging, so
439  * the different source entries are designed primarily for
440  * the source trees, with the old index being really mainly
441  * used for being replaced by the result.
442  *
443  * For diffing, the index is more important, and we only have a
444  * single tree.
445  *
446  * We're supposed to advance o->pos to skip what we have already processed.
447  *
448  * This wrapper makes it all more readable, and takes care of all
449  * the fairly complex unpack_trees() semantic requirements, including
450  * the skipping, the path matching, the type conflict cases etc.
451  */
452 static int oneway_diff(const struct cache_entry * const *src,
453                        struct unpack_trees_options *o)
454 {
455         const struct cache_entry *idx = src[0];
456         const struct cache_entry *tree = src[1];
457         struct rev_info *revs = o->unpack_data;
458
459         /*
460          * Unpack-trees generates a DF/conflict entry if
461          * there was a directory in the index and a tree
462          * in the tree. From a diff standpoint, that's a
463          * delete of the tree and a create of the file.
464          */
465         if (tree == o->df_conflict_entry)
466                 tree = NULL;
467
468         if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
469                 do_oneway_diff(o, idx, tree);
470                 if (diff_can_quit_early(&revs->diffopt)) {
471                         o->exiting_early = 1;
472                         return -1;
473                 }
474         }
475
476         return 0;
477 }
478
479 static int diff_cache(struct rev_info *revs,
480                       const struct object_id *tree_oid,
481                       const char *tree_name,
482                       int cached)
483 {
484         struct tree *tree;
485         struct tree_desc t;
486         struct unpack_trees_options opts;
487
488         tree = parse_tree_indirect(tree_oid);
489         if (!tree)
490                 return error("bad tree object %s",
491                              tree_name ? tree_name : oid_to_hex(tree_oid));
492         memset(&opts, 0, sizeof(opts));
493         opts.head_idx = 1;
494         opts.index_only = cached;
495         opts.diff_index_cached = (cached &&
496                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
497         opts.merge = 1;
498         opts.fn = oneway_diff;
499         opts.unpack_data = revs;
500         opts.src_index = &the_index;
501         opts.dst_index = NULL;
502         opts.pathspec = &revs->diffopt.pathspec;
503         opts.pathspec->recursive = 1;
504
505         init_tree_desc(&t, tree->buffer, tree->size);
506         return unpack_trees(1, &t, &opts);
507 }
508
509 int run_diff_index(struct rev_info *revs, int cached)
510 {
511         struct object_array_entry *ent;
512
513         ent = revs->pending.objects;
514         if (diff_cache(revs, &ent->item->oid, ent->name, cached))
515                 exit(128);
516
517         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
518         diffcore_fix_diff_index(&revs->diffopt);
519         diffcore_std(&revs->diffopt);
520         diff_flush(&revs->diffopt);
521         return 0;
522 }
523
524 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
525 {
526         struct rev_info revs;
527
528         init_revisions(&revs, NULL);
529         copy_pathspec(&revs.prune_data, &opt->pathspec);
530         revs.diffopt = *opt;
531
532         if (diff_cache(&revs, tree_oid, NULL, 1))
533                 exit(128);
534         return 0;
535 }
536
537 int index_differs_from(const char *def, int diff_flags,
538                        int ita_invisible_in_index)
539 {
540         struct rev_info rev;
541         struct setup_revision_opt opt;
542
543         init_revisions(&rev, NULL);
544         memset(&opt, 0, sizeof(opt));
545         opt.def = def;
546         setup_revisions(0, NULL, &rev, &opt);
547         DIFF_OPT_SET(&rev.diffopt, QUICK);
548         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
549         rev.diffopt.flags |= diff_flags;
550         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
551         run_diff_index(&rev, 1);
552         if (rev.pending.alloc)
553                 free(rev.pending.objects);
554         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
555 }