Merge branch 'pt/pull-tags-error-diag'
[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                 const unsigned char *old_sha1, *new_sha1;
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                                         hashcpy(dpath->parent[stage-2].oid.hash, nce->sha1);
159                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
160                                         dpath->parent[stage-2].status =
161                                                 DIFF_STATUS_MODIFIED;
162                                 }
163
164                                 /* diff against the proper unmerged stage */
165                                 if (stage == diff_unmerged_stage)
166                                         ce = nce;
167                                 i++;
168                         }
169                         /*
170                          * Compensate for loop update
171                          */
172                         i--;
173
174                         if (revs->combine_merges && num_compare_stages == 2) {
175                                 show_combined_diff(dpath, 2,
176                                                    revs->dense_combined_merges,
177                                                    revs);
178                                 free(dpath);
179                                 continue;
180                         }
181                         free(dpath);
182                         dpath = NULL;
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->sha1, !is_null_sha1(ce->sha1),
213                                                ce->name, 0);
214                                 continue;
215                         } else if (ce->ce_flags & CE_INTENT_TO_ADD) {
216                                 diff_addremove(&revs->diffopt, '+', ce->ce_mode,
217                                                EMPTY_BLOB_SHA1_BIN, 0,
218                                                ce->name, 0);
219                                 continue;
220                         }
221
222                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
223                                                             ce_option, &dirty_submodule);
224                         newmode = ce_mode_from_stat(ce, st.st_mode);
225                 }
226
227                 if (!changed && !dirty_submodule) {
228                         ce_mark_uptodate(ce);
229                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
230                                 continue;
231                 }
232                 oldmode = ce->ce_mode;
233                 old_sha1 = ce->sha1;
234                 new_sha1 = changed ? null_sha1 : ce->sha1;
235                 diff_change(&revs->diffopt, oldmode, newmode,
236                             old_sha1, new_sha1,
237                             !is_null_sha1(old_sha1),
238                             !is_null_sha1(new_sha1),
239                             ce->name, 0, dirty_submodule);
240
241         }
242         diffcore_std(&revs->diffopt);
243         diff_flush(&revs->diffopt);
244         return 0;
245 }
246
247 /*
248  * diff-index
249  */
250
251 /* A file entry went away or appeared */
252 static void diff_index_show_file(struct rev_info *revs,
253                                  const char *prefix,
254                                  const struct cache_entry *ce,
255                                  const unsigned char *sha1, int sha1_valid,
256                                  unsigned int mode,
257                                  unsigned dirty_submodule)
258 {
259         diff_addremove(&revs->diffopt, prefix[0], mode,
260                        sha1, sha1_valid, ce->name, dirty_submodule);
261 }
262
263 static int get_stat_data(const struct cache_entry *ce,
264                          const unsigned char **sha1p,
265                          unsigned int *modep,
266                          int cached, int match_missing,
267                          unsigned *dirty_submodule, struct diff_options *diffopt)
268 {
269         const unsigned char *sha1 = ce->sha1;
270         unsigned int mode = ce->ce_mode;
271
272         if (!cached && !ce_uptodate(ce)) {
273                 int changed;
274                 struct stat st;
275                 changed = check_removed(ce, &st);
276                 if (changed < 0)
277                         return -1;
278                 else if (changed) {
279                         if (match_missing) {
280                                 *sha1p = sha1;
281                                 *modep = mode;
282                                 return 0;
283                         }
284                         return -1;
285                 }
286                 changed = match_stat_with_submodule(diffopt, ce, &st,
287                                                     0, dirty_submodule);
288                 if (changed) {
289                         mode = ce_mode_from_stat(ce, st.st_mode);
290                         sha1 = null_sha1;
291                 }
292         }
293
294         *sha1p = sha1;
295         *modep = mode;
296         return 0;
297 }
298
299 static void show_new_file(struct rev_info *revs,
300                           const struct cache_entry *new,
301                           int cached, int match_missing)
302 {
303         const unsigned char *sha1;
304         unsigned int mode;
305         unsigned dirty_submodule = 0;
306
307         /*
308          * New file in the index: it might actually be different in
309          * the working tree.
310          */
311         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
312             &dirty_submodule, &revs->diffopt) < 0)
313                 return;
314
315         diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
316 }
317
318 static int show_modified(struct rev_info *revs,
319                          const struct cache_entry *old,
320                          const struct cache_entry *new,
321                          int report_missing,
322                          int cached, int match_missing)
323 {
324         unsigned int mode, oldmode;
325         const unsigned char *sha1;
326         unsigned dirty_submodule = 0;
327
328         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
329                           &dirty_submodule, &revs->diffopt) < 0) {
330                 if (report_missing)
331                         diff_index_show_file(revs, "-", old,
332                                              old->sha1, 1, old->ce_mode, 0);
333                 return -1;
334         }
335
336         if (revs->combine_merges && !cached &&
337             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
338                 struct combine_diff_path *p;
339                 int pathlen = ce_namelen(new);
340
341                 p = xmalloc(combine_diff_path_size(2, pathlen));
342                 p->path = (char *) &p->parent[2];
343                 p->next = NULL;
344                 memcpy(p->path, new->name, pathlen);
345                 p->path[pathlen] = 0;
346                 p->mode = mode;
347                 oidclr(&p->oid);
348                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
349                 p->parent[0].status = DIFF_STATUS_MODIFIED;
350                 p->parent[0].mode = new->ce_mode;
351                 hashcpy(p->parent[0].oid.hash, new->sha1);
352                 p->parent[1].status = DIFF_STATUS_MODIFIED;
353                 p->parent[1].mode = old->ce_mode;
354                 hashcpy(p->parent[1].oid.hash, old->sha1);
355                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
356                 free(p);
357                 return 0;
358         }
359
360         oldmode = old->ce_mode;
361         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
362             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
363                 return 0;
364
365         diff_change(&revs->diffopt, oldmode, mode,
366                     old->sha1, sha1, 1, !is_null_sha1(sha1),
367                     old->name, 0, dirty_submodule);
368         return 0;
369 }
370
371 /*
372  * This gets a mix of an existing index and a tree, one pathname entry
373  * at a time. The index entry may be a single stage-0 one, but it could
374  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
375  * give you the position and number of entries in the index).
376  */
377 static void do_oneway_diff(struct unpack_trees_options *o,
378                            const struct cache_entry *idx,
379                            const struct cache_entry *tree)
380 {
381         struct rev_info *revs = o->unpack_data;
382         int match_missing, cached;
383
384         /* i-t-a entries do not actually exist in the index */
385         if (idx && (idx->ce_flags & CE_INTENT_TO_ADD)) {
386                 idx = NULL;
387                 if (!tree)
388                         return; /* nothing to diff.. */
389         }
390
391         /* if the entry is not checked out, don't examine work tree */
392         cached = o->index_only ||
393                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
394         /*
395          * Backward compatibility wart - "diff-index -m" does
396          * not mean "do not ignore merges", but "match_missing".
397          *
398          * But with the revision flag parsing, that's found in
399          * "!revs->ignore_merges".
400          */
401         match_missing = !revs->ignore_merges;
402
403         if (cached && idx && ce_stage(idx)) {
404                 struct diff_filepair *pair;
405                 pair = diff_unmerge(&revs->diffopt, idx->name);
406                 if (tree)
407                         fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
408                 return;
409         }
410
411         /*
412          * Something added to the tree?
413          */
414         if (!tree) {
415                 show_new_file(revs, idx, cached, match_missing);
416                 return;
417         }
418
419         /*
420          * Something removed from the tree?
421          */
422         if (!idx) {
423                 diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
424                 return;
425         }
426
427         /* Show difference between old and new */
428         show_modified(revs, tree, idx, 1, cached, match_missing);
429 }
430
431 /*
432  * The unpack_trees() interface is designed for merging, so
433  * the different source entries are designed primarily for
434  * the source trees, with the old index being really mainly
435  * used for being replaced by the result.
436  *
437  * For diffing, the index is more important, and we only have a
438  * single tree.
439  *
440  * We're supposed to advance o->pos to skip what we have already processed.
441  *
442  * This wrapper makes it all more readable, and takes care of all
443  * the fairly complex unpack_trees() semantic requirements, including
444  * the skipping, the path matching, the type conflict cases etc.
445  */
446 static int oneway_diff(const struct cache_entry * const *src,
447                        struct unpack_trees_options *o)
448 {
449         const struct cache_entry *idx = src[0];
450         const struct cache_entry *tree = src[1];
451         struct rev_info *revs = o->unpack_data;
452
453         /*
454          * Unpack-trees generates a DF/conflict entry if
455          * there was a directory in the index and a tree
456          * in the tree. From a diff standpoint, that's a
457          * delete of the tree and a create of the file.
458          */
459         if (tree == o->df_conflict_entry)
460                 tree = NULL;
461
462         if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
463                 do_oneway_diff(o, idx, tree);
464                 if (diff_can_quit_early(&revs->diffopt)) {
465                         o->exiting_early = 1;
466                         return -1;
467                 }
468         }
469
470         return 0;
471 }
472
473 static int diff_cache(struct rev_info *revs,
474                       const unsigned char *tree_sha1,
475                       const char *tree_name,
476                       int cached)
477 {
478         struct tree *tree;
479         struct tree_desc t;
480         struct unpack_trees_options opts;
481
482         tree = parse_tree_indirect(tree_sha1);
483         if (!tree)
484                 return error("bad tree object %s",
485                              tree_name ? tree_name : sha1_to_hex(tree_sha1));
486         memset(&opts, 0, sizeof(opts));
487         opts.head_idx = 1;
488         opts.index_only = cached;
489         opts.diff_index_cached = (cached &&
490                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
491         opts.merge = 1;
492         opts.fn = oneway_diff;
493         opts.unpack_data = revs;
494         opts.src_index = &the_index;
495         opts.dst_index = NULL;
496         opts.pathspec = &revs->diffopt.pathspec;
497         opts.pathspec->recursive = 1;
498
499         init_tree_desc(&t, tree->buffer, tree->size);
500         return unpack_trees(1, &t, &opts);
501 }
502
503 int run_diff_index(struct rev_info *revs, int cached)
504 {
505         struct object_array_entry *ent;
506
507         ent = revs->pending.objects;
508         if (diff_cache(revs, ent->item->sha1, ent->name, cached))
509                 exit(128);
510
511         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
512         diffcore_fix_diff_index(&revs->diffopt);
513         diffcore_std(&revs->diffopt);
514         diff_flush(&revs->diffopt);
515         return 0;
516 }
517
518 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
519 {
520         struct rev_info revs;
521
522         init_revisions(&revs, NULL);
523         copy_pathspec(&revs.prune_data, &opt->pathspec);
524         revs.diffopt = *opt;
525
526         if (diff_cache(&revs, tree_sha1, NULL, 1))
527                 exit(128);
528         return 0;
529 }
530
531 int index_differs_from(const char *def, int diff_flags)
532 {
533         struct rev_info rev;
534         struct setup_revision_opt opt;
535
536         init_revisions(&rev, NULL);
537         memset(&opt, 0, sizeof(opt));
538         opt.def = def;
539         setup_revisions(0, NULL, &rev, &opt);
540         DIFF_OPT_SET(&rev.diffopt, QUICK);
541         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
542         rev.diffopt.flags |= diff_flags;
543         run_diff_index(&rev, 1);
544         if (rev.pending.alloc)
545                 free(rev.pending.objects);
546         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
547 }