Merge branch 'jk/push-simple' into maint
[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 (errno != ENOENT && errno != ENOTDIR)
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
105                 if (diff_can_quit_early(&revs->diffopt))
106                         break;
107
108                 if (!ce_path_match(ce, &revs->prune_data, NULL))
109                         continue;
110
111                 if (ce_stage(ce)) {
112                         struct combine_diff_path *dpath;
113                         struct diff_filepair *pair;
114                         unsigned int wt_mode = 0;
115                         int num_compare_stages = 0;
116                         size_t path_len;
117                         struct stat st;
118
119                         path_len = ce_namelen(ce);
120
121                         dpath = xmalloc(combine_diff_path_size(5, path_len));
122                         dpath->path = (char *) &(dpath->parent[5]);
123
124                         dpath->next = NULL;
125                         memcpy(dpath->path, ce->name, path_len);
126                         dpath->path[path_len] = '\0';
127                         hashclr(dpath->sha1);
128                         memset(&(dpath->parent[0]), 0,
129                                sizeof(struct combine_diff_parent)*5);
130
131                         changed = check_removed(ce, &st);
132                         if (!changed)
133                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
134                         else {
135                                 if (changed < 0) {
136                                         perror(ce->name);
137                                         continue;
138                                 }
139                                 wt_mode = 0;
140                         }
141                         dpath->mode = wt_mode;
142
143                         while (i < entries) {
144                                 struct cache_entry *nce = active_cache[i];
145                                 int stage;
146
147                                 if (strcmp(ce->name, nce->name))
148                                         break;
149
150                                 /* Stage #2 (ours) is the first parent,
151                                  * stage #3 (theirs) is the second.
152                                  */
153                                 stage = ce_stage(nce);
154                                 if (2 <= stage) {
155                                         int mode = nce->ce_mode;
156                                         num_compare_stages++;
157                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
158                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
159                                         dpath->parent[stage-2].status =
160                                                 DIFF_STATUS_MODIFIED;
161                                 }
162
163                                 /* diff against the proper unmerged stage */
164                                 if (stage == diff_unmerged_stage)
165                                         ce = nce;
166                                 i++;
167                         }
168                         /*
169                          * Compensate for loop update
170                          */
171                         i--;
172
173                         if (revs->combine_merges && num_compare_stages == 2) {
174                                 show_combined_diff(dpath, 2,
175                                                    revs->dense_combined_merges,
176                                                    revs);
177                                 free(dpath);
178                                 continue;
179                         }
180                         free(dpath);
181                         dpath = NULL;
182
183                         /*
184                          * Show the diff for the 'ce' if we found the one
185                          * from the desired stage.
186                          */
187                         pair = diff_unmerge(&revs->diffopt, ce->name);
188                         if (wt_mode)
189                                 pair->two->mode = wt_mode;
190                         if (ce_stage(ce) != diff_unmerged_stage)
191                                 continue;
192                 }
193
194                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
195                         continue;
196
197                 /* If CE_VALID is set, don't look at workdir for file removal */
198                 if (ce->ce_flags & CE_VALID) {
199                         changed = 0;
200                         newmode = ce->ce_mode;
201                 } else {
202                         struct stat st;
203
204                         changed = check_removed(ce, &st);
205                         if (changed) {
206                                 if (changed < 0) {
207                                         perror(ce->name);
208                                         continue;
209                                 }
210                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
211                                                ce->sha1, !is_null_sha1(ce->sha1),
212                                                ce->name, 0);
213                                 continue;
214                         }
215
216                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
217                                                             ce_option, &dirty_submodule);
218                         newmode = ce_mode_from_stat(ce, st.st_mode);
219                 }
220
221                 if (!changed && !dirty_submodule) {
222                         ce_mark_uptodate(ce);
223                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
224                                 continue;
225                 }
226                 oldmode = ce->ce_mode;
227                 diff_change(&revs->diffopt, oldmode, newmode,
228                             ce->sha1, (changed ? null_sha1 : ce->sha1),
229                             !is_null_sha1(ce->sha1), (changed ? 0 : !is_null_sha1(ce->sha1)),
230                             ce->name, 0, dirty_submodule);
231
232         }
233         diffcore_std(&revs->diffopt);
234         diff_flush(&revs->diffopt);
235         return 0;
236 }
237
238 /*
239  * diff-index
240  */
241
242 /* A file entry went away or appeared */
243 static void diff_index_show_file(struct rev_info *revs,
244                                  const char *prefix,
245                                  const struct cache_entry *ce,
246                                  const unsigned char *sha1, int sha1_valid,
247                                  unsigned int mode,
248                                  unsigned dirty_submodule)
249 {
250         diff_addremove(&revs->diffopt, prefix[0], mode,
251                        sha1, sha1_valid, ce->name, dirty_submodule);
252 }
253
254 static int get_stat_data(const struct cache_entry *ce,
255                          const unsigned char **sha1p,
256                          unsigned int *modep,
257                          int cached, int match_missing,
258                          unsigned *dirty_submodule, struct diff_options *diffopt)
259 {
260         const unsigned char *sha1 = ce->sha1;
261         unsigned int mode = ce->ce_mode;
262
263         if (!cached && !ce_uptodate(ce)) {
264                 int changed;
265                 struct stat st;
266                 changed = check_removed(ce, &st);
267                 if (changed < 0)
268                         return -1;
269                 else if (changed) {
270                         if (match_missing) {
271                                 *sha1p = sha1;
272                                 *modep = mode;
273                                 return 0;
274                         }
275                         return -1;
276                 }
277                 changed = match_stat_with_submodule(diffopt, ce, &st,
278                                                     0, dirty_submodule);
279                 if (changed) {
280                         mode = ce_mode_from_stat(ce, st.st_mode);
281                         sha1 = null_sha1;
282                 }
283         }
284
285         *sha1p = sha1;
286         *modep = mode;
287         return 0;
288 }
289
290 static void show_new_file(struct rev_info *revs,
291                           const struct cache_entry *new,
292                           int cached, int match_missing)
293 {
294         const unsigned char *sha1;
295         unsigned int mode;
296         unsigned dirty_submodule = 0;
297
298         /*
299          * New file in the index: it might actually be different in
300          * the working tree.
301          */
302         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
303             &dirty_submodule, &revs->diffopt) < 0)
304                 return;
305
306         diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
307 }
308
309 static int show_modified(struct rev_info *revs,
310                          const struct cache_entry *old,
311                          const struct cache_entry *new,
312                          int report_missing,
313                          int cached, int match_missing)
314 {
315         unsigned int mode, oldmode;
316         const unsigned char *sha1;
317         unsigned dirty_submodule = 0;
318
319         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
320                           &dirty_submodule, &revs->diffopt) < 0) {
321                 if (report_missing)
322                         diff_index_show_file(revs, "-", old,
323                                              old->sha1, 1, old->ce_mode, 0);
324                 return -1;
325         }
326
327         if (revs->combine_merges && !cached &&
328             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
329                 struct combine_diff_path *p;
330                 int pathlen = ce_namelen(new);
331
332                 p = xmalloc(combine_diff_path_size(2, pathlen));
333                 p->path = (char *) &p->parent[2];
334                 p->next = NULL;
335                 memcpy(p->path, new->name, pathlen);
336                 p->path[pathlen] = 0;
337                 p->mode = mode;
338                 hashclr(p->sha1);
339                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
340                 p->parent[0].status = DIFF_STATUS_MODIFIED;
341                 p->parent[0].mode = new->ce_mode;
342                 hashcpy(p->parent[0].sha1, new->sha1);
343                 p->parent[1].status = DIFF_STATUS_MODIFIED;
344                 p->parent[1].mode = old->ce_mode;
345                 hashcpy(p->parent[1].sha1, old->sha1);
346                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
347                 free(p);
348                 return 0;
349         }
350
351         oldmode = old->ce_mode;
352         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
353             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
354                 return 0;
355
356         diff_change(&revs->diffopt, oldmode, mode,
357                     old->sha1, sha1, 1, !is_null_sha1(sha1),
358                     old->name, 0, dirty_submodule);
359         return 0;
360 }
361
362 /*
363  * This gets a mix of an existing index and a tree, one pathname entry
364  * at a time. The index entry may be a single stage-0 one, but it could
365  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
366  * give you the position and number of entries in the index).
367  */
368 static void do_oneway_diff(struct unpack_trees_options *o,
369                            const struct cache_entry *idx,
370                            const struct cache_entry *tree)
371 {
372         struct rev_info *revs = o->unpack_data;
373         int match_missing, cached;
374
375         /* if the entry is not checked out, don't examine work tree */
376         cached = o->index_only ||
377                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
378         /*
379          * Backward compatibility wart - "diff-index -m" does
380          * not mean "do not ignore merges", but "match_missing".
381          *
382          * But with the revision flag parsing, that's found in
383          * "!revs->ignore_merges".
384          */
385         match_missing = !revs->ignore_merges;
386
387         if (cached && idx && ce_stage(idx)) {
388                 struct diff_filepair *pair;
389                 pair = diff_unmerge(&revs->diffopt, idx->name);
390                 if (tree)
391                         fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
392                 return;
393         }
394
395         /*
396          * Something added to the tree?
397          */
398         if (!tree) {
399                 show_new_file(revs, idx, cached, match_missing);
400                 return;
401         }
402
403         /*
404          * Something removed from the tree?
405          */
406         if (!idx) {
407                 diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
408                 return;
409         }
410
411         /* Show difference between old and new */
412         show_modified(revs, tree, idx, 1, cached, match_missing);
413 }
414
415 /*
416  * The unpack_trees() interface is designed for merging, so
417  * the different source entries are designed primarily for
418  * the source trees, with the old index being really mainly
419  * used for being replaced by the result.
420  *
421  * For diffing, the index is more important, and we only have a
422  * single tree.
423  *
424  * We're supposed to advance o->pos to skip what we have already processed.
425  *
426  * This wrapper makes it all more readable, and takes care of all
427  * the fairly complex unpack_trees() semantic requirements, including
428  * the skipping, the path matching, the type conflict cases etc.
429  */
430 static int oneway_diff(const struct cache_entry * const *src,
431                        struct unpack_trees_options *o)
432 {
433         const struct cache_entry *idx = src[0];
434         const struct cache_entry *tree = src[1];
435         struct rev_info *revs = o->unpack_data;
436
437         /*
438          * Unpack-trees generates a DF/conflict entry if
439          * there was a directory in the index and a tree
440          * in the tree. From a diff standpoint, that's a
441          * delete of the tree and a create of the file.
442          */
443         if (tree == o->df_conflict_entry)
444                 tree = NULL;
445
446         if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
447                 do_oneway_diff(o, idx, tree);
448                 if (diff_can_quit_early(&revs->diffopt)) {
449                         o->exiting_early = 1;
450                         return -1;
451                 }
452         }
453
454         return 0;
455 }
456
457 static int diff_cache(struct rev_info *revs,
458                       const unsigned char *tree_sha1,
459                       const char *tree_name,
460                       int cached)
461 {
462         struct tree *tree;
463         struct tree_desc t;
464         struct unpack_trees_options opts;
465
466         tree = parse_tree_indirect(tree_sha1);
467         if (!tree)
468                 return error("bad tree object %s",
469                              tree_name ? tree_name : sha1_to_hex(tree_sha1));
470         memset(&opts, 0, sizeof(opts));
471         opts.head_idx = 1;
472         opts.index_only = cached;
473         opts.diff_index_cached = (cached &&
474                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
475         opts.merge = 1;
476         opts.fn = oneway_diff;
477         opts.unpack_data = revs;
478         opts.src_index = &the_index;
479         opts.dst_index = NULL;
480         opts.pathspec = &revs->diffopt.pathspec;
481         opts.pathspec->recursive = 1;
482
483         init_tree_desc(&t, tree->buffer, tree->size);
484         return unpack_trees(1, &t, &opts);
485 }
486
487 int run_diff_index(struct rev_info *revs, int cached)
488 {
489         struct object_array_entry *ent;
490
491         ent = revs->pending.objects;
492         if (diff_cache(revs, ent->item->sha1, ent->name, cached))
493                 exit(128);
494
495         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
496         diffcore_fix_diff_index(&revs->diffopt);
497         diffcore_std(&revs->diffopt);
498         diff_flush(&revs->diffopt);
499         return 0;
500 }
501
502 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
503 {
504         struct rev_info revs;
505
506         init_revisions(&revs, NULL);
507         copy_pathspec(&revs.prune_data, &opt->pathspec);
508         revs.diffopt = *opt;
509
510         if (diff_cache(&revs, tree_sha1, NULL, 1))
511                 exit(128);
512         return 0;
513 }
514
515 int index_differs_from(const char *def, int diff_flags)
516 {
517         struct rev_info rev;
518         struct setup_revision_opt opt;
519
520         init_revisions(&rev, NULL);
521         memset(&opt, 0, sizeof(opt));
522         opt.def = def;
523         setup_revisions(0, NULL, &rev, &opt);
524         DIFF_OPT_SET(&rev.diffopt, QUICK);
525         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
526         rev.diffopt.flags |= diff_flags;
527         run_diff_index(&rev, 1);
528         if (rev.pending.alloc)
529                 free(rev.pending.objects);
530         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
531 }