Merge branch 'jc/cachetree' into cr/reset
[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 "path-list.h"
12
13 /*
14  * diff-files
15  */
16
17 static int read_directory(const char *path, struct path_list *list)
18 {
19         DIR *dir;
20         struct dirent *e;
21
22         if (!(dir = opendir(path)))
23                 return error("Could not open directory %s", path);
24
25         while ((e = readdir(dir)))
26                 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
27                         path_list_insert(e->d_name, list);
28
29         closedir(dir);
30         return 0;
31 }
32
33 static int get_mode(const char *path, int *mode)
34 {
35         struct stat st;
36
37         if (!path || !strcmp(path, "/dev/null"))
38                 *mode = 0;
39         else if (!strcmp(path, "-"))
40                 *mode = ntohl(create_ce_mode(0666));
41         else if (stat(path, &st))
42                 return error("Could not access '%s'", path);
43         else
44                 *mode = st.st_mode;
45         return 0;
46 }
47
48 static int queue_diff(struct diff_options *o,
49                 const char *name1, const char *name2)
50 {
51         int mode1 = 0, mode2 = 0;
52
53         if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
54                 return -1;
55
56         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
57                 return error("file/directory conflict: %s, %s", name1, name2);
58
59         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
60                 char buffer1[PATH_MAX], buffer2[PATH_MAX];
61                 struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
62                 int len1 = 0, len2 = 0, i1, i2, ret = 0;
63
64                 if (name1 && read_directory(name1, &p1))
65                         return -1;
66                 if (name2 && read_directory(name2, &p2)) {
67                         path_list_clear(&p1, 0);
68                         return -1;
69                 }
70
71                 if (name1) {
72                         len1 = strlen(name1);
73                         if (len1 > 0 && name1[len1 - 1] == '/')
74                                 len1--;
75                         memcpy(buffer1, name1, len1);
76                         buffer1[len1++] = '/';
77                 }
78
79                 if (name2) {
80                         len2 = strlen(name2);
81                         if (len2 > 0 && name2[len2 - 1] == '/')
82                                 len2--;
83                         memcpy(buffer2, name2, len2);
84                         buffer2[len2++] = '/';
85                 }
86
87                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
88                         const char *n1, *n2;
89                         int comp;
90
91                         if (i1 == p1.nr)
92                                 comp = 1;
93                         else if (i2 == p2.nr)
94                                 comp = -1;
95                         else
96                                 comp = strcmp(p1.items[i1].path,
97                                         p2.items[i2].path);
98
99                         if (comp > 0)
100                                 n1 = NULL;
101                         else {
102                                 n1 = buffer1;
103                                 strncpy(buffer1 + len1, p1.items[i1++].path,
104                                                 PATH_MAX - len1);
105                         }
106
107                         if (comp < 0)
108                                 n2 = NULL;
109                         else {
110                                 n2 = buffer2;
111                                 strncpy(buffer2 + len2, p2.items[i2++].path,
112                                                 PATH_MAX - len2);
113                         }
114
115                         ret = queue_diff(o, n1, n2);
116                 }
117                 path_list_clear(&p1, 0);
118                 path_list_clear(&p2, 0);
119
120                 return ret;
121         } else {
122                 struct diff_filespec *d1, *d2;
123
124                 if (o->reverse_diff) {
125                         unsigned tmp;
126                         const char *tmp_c;
127                         tmp = mode1; mode1 = mode2; mode2 = tmp;
128                         tmp_c = name1; name1 = name2; name2 = tmp_c;
129                 }
130
131                 if (!name1)
132                         name1 = "/dev/null";
133                 if (!name2)
134                         name2 = "/dev/null";
135                 d1 = alloc_filespec(name1);
136                 d2 = alloc_filespec(name2);
137                 fill_filespec(d1, null_sha1, mode1);
138                 fill_filespec(d2, null_sha1, mode2);
139
140                 diff_queue(&diff_queued_diff, d1, d2);
141                 return 0;
142         }
143 }
144
145 /*
146  * Does the path name a blob in the working tree, or a directory
147  * in the working tree?
148  */
149 static int is_in_index(const char *path)
150 {
151         int len, pos;
152         struct cache_entry *ce;
153
154         len = strlen(path);
155         while (path[len-1] == '/')
156                 len--;
157         if (!len)
158                 return 1; /* "." */
159         pos = cache_name_pos(path, len);
160         if (0 <= pos)
161                 return 1;
162         pos = -1 - pos;
163         while (pos < active_nr) {
164                 ce = active_cache[pos++];
165                 if (ce_namelen(ce) <= len ||
166                     strncmp(ce->name, path, len) ||
167                     (ce->name[len] > '/'))
168                         break; /* path cannot be a prefix */
169                 if (ce->name[len] == '/')
170                         return 1;
171         }
172         return 0;
173 }
174
175 static int handle_diff_files_args(struct rev_info *revs,
176                 int argc, const char **argv, int *silent)
177 {
178         *silent = 0;
179
180         /* revs->max_count == -2 means --no-index */
181         while (1 < argc && argv[1][0] == '-') {
182                 if (!strcmp(argv[1], "--base"))
183                         revs->max_count = 1;
184                 else if (!strcmp(argv[1], "--ours"))
185                         revs->max_count = 2;
186                 else if (!strcmp(argv[1], "--theirs"))
187                         revs->max_count = 3;
188                 else if (!strcmp(argv[1], "-n") ||
189                                 !strcmp(argv[1], "--no-index")) {
190                         revs->max_count = -2;
191                         revs->diffopt.exit_with_status = 1;
192                         revs->diffopt.no_index = 1;
193                 }
194                 else if (!strcmp(argv[1], "-q"))
195                         *silent = 1;
196                 else
197                         return error("invalid option: %s", argv[1]);
198                 argv++; argc--;
199         }
200
201         if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
202                 /*
203                  * If two files are specified, and at least one is untracked,
204                  * default to no-index.
205                  */
206                 read_cache();
207                 if (!is_in_index(revs->diffopt.paths[0]) ||
208                                         !is_in_index(revs->diffopt.paths[1])) {
209                         revs->max_count = -2;
210                         revs->diffopt.no_index = 1;
211                 }
212         }
213
214         /*
215          * Make sure there are NO revision (i.e. pending object) parameter,
216          * rev.max_count is reasonable (0 <= n <= 3),
217          * there is no other revision filtering parameters.
218          */
219         if (revs->pending.nr || revs->max_count > 3 ||
220             revs->min_age != -1 || revs->max_age != -1)
221                 return error("no revision allowed with diff-files");
222
223         if (revs->max_count == -1 &&
224             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
225                 revs->combine_merges = revs->dense_combined_merges = 1;
226
227         return 0;
228 }
229
230 static int is_outside_repo(const char *path, int nongit, const char *prefix)
231 {
232         int i;
233         if (nongit || !strcmp(path, "-") || path[0] == '/')
234                 return 1;
235         if (prefixcmp(path, "../"))
236                 return 0;
237         if (!prefix)
238                 return 1;
239         for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
240                 while (i > 0 && prefix[i - 1] != '/')
241                         i--;
242                 if (--i < 0)
243                         return 1;
244                 path += 3;
245         }
246         return 0;
247 }
248
249 int setup_diff_no_index(struct rev_info *revs,
250                 int argc, const char ** argv, int nongit, const char *prefix)
251 {
252         int i;
253         for (i = 1; i < argc; i++)
254                 if (argv[i][0] != '-' || argv[i][1] == '\0')
255                         break;
256                 else if (!strcmp(argv[i], "--")) {
257                         i++;
258                         break;
259                 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
260                         i = argc - 3;
261                         revs->diffopt.exit_with_status = 1;
262                         break;
263                 }
264         if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
265                                 !is_outside_repo(argv[i], nongit, prefix)))
266                 return -1;
267
268         diff_setup(&revs->diffopt);
269         for (i = 1; i < argc - 2; )
270                 if (!strcmp(argv[i], "--no-index"))
271                         i++;
272                 else {
273                         int j = diff_opt_parse(&revs->diffopt,
274                                         argv + i, argc - i);
275                         if (!j)
276                                 die("invalid diff option/value: %s", argv[i]);
277                         i += j;
278                 }
279
280         if (prefix) {
281                 int len = strlen(prefix);
282
283                 revs->diffopt.paths = xcalloc(2, sizeof(char*));
284                 for (i = 0; i < 2; i++) {
285                         const char *p = argv[argc - 2 + i];
286                         /*
287                          * stdin should be spelled as '-'; if you have
288                          * path that is '-', spell it as ./-.
289                          */
290                         p = (strcmp(p, "-")
291                              ? xstrdup(prefix_filename(prefix, len, p))
292                              : p);
293                         revs->diffopt.paths[i] = p;
294                 }
295         }
296         else
297                 revs->diffopt.paths = argv + argc - 2;
298         revs->diffopt.nr_paths = 2;
299         revs->diffopt.no_index = 1;
300         revs->max_count = -2;
301         return 0;
302 }
303
304 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
305 {
306         int silent_on_removed;
307
308         if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
309                 return -1;
310
311         if (revs->diffopt.no_index) {
312                 if (revs->diffopt.nr_paths != 2)
313                         return error("need two files/directories with --no-index");
314                 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
315                                 revs->diffopt.paths[1]))
316                         return -1;
317                 diffcore_std(&revs->diffopt);
318                 diff_flush(&revs->diffopt);
319                 /*
320                  * The return code for --no-index imitates diff(1):
321                  * 0 = no changes, 1 = changes, else error
322                  */
323                 return revs->diffopt.found_changes;
324         }
325
326         if (read_cache() < 0) {
327                 perror("read_cache");
328                 return -1;
329         }
330         return run_diff_files(revs, silent_on_removed);
331 }
332
333 int run_diff_files(struct rev_info *revs, int silent_on_removed)
334 {
335         int entries, i;
336         int diff_unmerged_stage = revs->max_count;
337
338         if (diff_unmerged_stage < 0)
339                 diff_unmerged_stage = 2;
340         entries = active_nr;
341         for (i = 0; i < entries; i++) {
342                 struct stat st;
343                 unsigned int oldmode, newmode;
344                 struct cache_entry *ce = active_cache[i];
345                 int changed;
346
347                 if (revs->diffopt.quiet && revs->diffopt.has_changes)
348                         break;
349
350                 if (!ce_path_match(ce, revs->prune_data))
351                         continue;
352
353                 if (ce_stage(ce)) {
354                         struct combine_diff_path *dpath;
355                         int num_compare_stages = 0;
356                         size_t path_len;
357
358                         path_len = ce_namelen(ce);
359
360                         dpath = xmalloc(combine_diff_path_size(5, path_len));
361                         dpath->path = (char *) &(dpath->parent[5]);
362
363                         dpath->next = NULL;
364                         dpath->len = path_len;
365                         memcpy(dpath->path, ce->name, path_len);
366                         dpath->path[path_len] = '\0';
367                         hashclr(dpath->sha1);
368                         memset(&(dpath->parent[0]), 0,
369                                sizeof(struct combine_diff_parent)*5);
370
371                         if (lstat(ce->name, &st) < 0) {
372                                 if (errno != ENOENT && errno != ENOTDIR) {
373                                         perror(ce->name);
374                                         continue;
375                                 }
376                                 if (silent_on_removed)
377                                         continue;
378                         }
379                         else
380                                 dpath->mode = ntohl(ce_mode_from_stat(ce, st.st_mode));
381
382                         while (i < entries) {
383                                 struct cache_entry *nce = active_cache[i];
384                                 int stage;
385
386                                 if (strcmp(ce->name, nce->name))
387                                         break;
388
389                                 /* Stage #2 (ours) is the first parent,
390                                  * stage #3 (theirs) is the second.
391                                  */
392                                 stage = ce_stage(nce);
393                                 if (2 <= stage) {
394                                         int mode = ntohl(nce->ce_mode);
395                                         num_compare_stages++;
396                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
397                                         dpath->parent[stage-2].mode = ntohl(ce_mode_from_stat(nce, mode));
398                                         dpath->parent[stage-2].status =
399                                                 DIFF_STATUS_MODIFIED;
400                                 }
401
402                                 /* diff against the proper unmerged stage */
403                                 if (stage == diff_unmerged_stage)
404                                         ce = nce;
405                                 i++;
406                         }
407                         /*
408                          * Compensate for loop update
409                          */
410                         i--;
411
412                         if (revs->combine_merges && num_compare_stages == 2) {
413                                 show_combined_diff(dpath, 2,
414                                                    revs->dense_combined_merges,
415                                                    revs);
416                                 free(dpath);
417                                 continue;
418                         }
419                         free(dpath);
420                         dpath = NULL;
421
422                         /*
423                          * Show the diff for the 'ce' if we found the one
424                          * from the desired stage.
425                          */
426                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
427                         if (ce_stage(ce) != diff_unmerged_stage)
428                                 continue;
429                 }
430
431                 if (lstat(ce->name, &st) < 0) {
432                         if (errno != ENOENT && errno != ENOTDIR) {
433                                 perror(ce->name);
434                                 continue;
435                         }
436                         if (silent_on_removed)
437                                 continue;
438                         diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
439                                        ce->sha1, ce->name, NULL);
440                         continue;
441                 }
442                 changed = ce_match_stat(ce, &st, 0);
443                 if (!changed && !revs->diffopt.find_copies_harder)
444                         continue;
445                 oldmode = ntohl(ce->ce_mode);
446                 newmode = ntohl(ce_mode_from_stat(ce, st.st_mode));
447                 diff_change(&revs->diffopt, oldmode, newmode,
448                             ce->sha1, (changed ? null_sha1 : ce->sha1),
449                             ce->name, NULL);
450
451         }
452         diffcore_std(&revs->diffopt);
453         diff_flush(&revs->diffopt);
454         return 0;
455 }
456
457 /*
458  * diff-index
459  */
460
461 /* A file entry went away or appeared */
462 static void diff_index_show_file(struct rev_info *revs,
463                                  const char *prefix,
464                                  struct cache_entry *ce,
465                                  unsigned char *sha1, unsigned int mode)
466 {
467         diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
468                        sha1, ce->name, NULL);
469 }
470
471 static int get_stat_data(struct cache_entry *ce,
472                          unsigned char **sha1p,
473                          unsigned int *modep,
474                          int cached, int match_missing)
475 {
476         unsigned char *sha1 = ce->sha1;
477         unsigned int mode = ce->ce_mode;
478
479         if (!cached) {
480                 static unsigned char no_sha1[20];
481                 int changed;
482                 struct stat st;
483                 if (lstat(ce->name, &st) < 0) {
484                         if (errno == ENOENT && match_missing) {
485                                 *sha1p = sha1;
486                                 *modep = mode;
487                                 return 0;
488                         }
489                         return -1;
490                 }
491                 changed = ce_match_stat(ce, &st, 0);
492                 if (changed) {
493                         mode = ce_mode_from_stat(ce, st.st_mode);
494                         sha1 = no_sha1;
495                 }
496         }
497
498         *sha1p = sha1;
499         *modep = mode;
500         return 0;
501 }
502
503 static void show_new_file(struct rev_info *revs,
504                           struct cache_entry *new,
505                           int cached, int match_missing)
506 {
507         unsigned char *sha1;
508         unsigned int mode;
509
510         /* New file in the index: it might actually be different in
511          * the working copy.
512          */
513         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
514                 return;
515
516         diff_index_show_file(revs, "+", new, sha1, mode);
517 }
518
519 static int show_modified(struct rev_info *revs,
520                          struct cache_entry *old,
521                          struct cache_entry *new,
522                          int report_missing,
523                          int cached, int match_missing)
524 {
525         unsigned int mode, oldmode;
526         unsigned char *sha1;
527
528         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
529                 if (report_missing)
530                         diff_index_show_file(revs, "-", old,
531                                              old->sha1, old->ce_mode);
532                 return -1;
533         }
534
535         if (revs->combine_merges && !cached &&
536             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
537                 struct combine_diff_path *p;
538                 int pathlen = ce_namelen(new);
539
540                 p = xmalloc(combine_diff_path_size(2, pathlen));
541                 p->path = (char *) &p->parent[2];
542                 p->next = NULL;
543                 p->len = pathlen;
544                 memcpy(p->path, new->name, pathlen);
545                 p->path[pathlen] = 0;
546                 p->mode = ntohl(mode);
547                 hashclr(p->sha1);
548                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
549                 p->parent[0].status = DIFF_STATUS_MODIFIED;
550                 p->parent[0].mode = ntohl(new->ce_mode);
551                 hashcpy(p->parent[0].sha1, new->sha1);
552                 p->parent[1].status = DIFF_STATUS_MODIFIED;
553                 p->parent[1].mode = ntohl(old->ce_mode);
554                 hashcpy(p->parent[1].sha1, old->sha1);
555                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
556                 free(p);
557                 return 0;
558         }
559
560         oldmode = old->ce_mode;
561         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
562             !revs->diffopt.find_copies_harder)
563                 return 0;
564
565         mode = ntohl(mode);
566         oldmode = ntohl(oldmode);
567
568         diff_change(&revs->diffopt, oldmode, mode,
569                     old->sha1, sha1, old->name, NULL);
570         return 0;
571 }
572
573 static int diff_cache(struct rev_info *revs,
574                       struct cache_entry **ac, int entries,
575                       const char **pathspec,
576                       int cached, int match_missing)
577 {
578         while (entries) {
579                 struct cache_entry *ce = *ac;
580                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
581
582                 if (revs->diffopt.quiet && revs->diffopt.has_changes)
583                         break;
584
585                 if (!ce_path_match(ce, pathspec))
586                         goto skip_entry;
587
588                 switch (ce_stage(ce)) {
589                 case 0:
590                         /* No stage 1 entry? That means it's a new file */
591                         if (!same) {
592                                 show_new_file(revs, ce, cached, match_missing);
593                                 break;
594                         }
595                         /* Show difference between old and new */
596                         show_modified(revs, ac[1], ce, 1,
597                                       cached, match_missing);
598                         break;
599                 case 1:
600                         /* No stage 3 (merge) entry?
601                          * That means it's been deleted.
602                          */
603                         if (!same) {
604                                 diff_index_show_file(revs, "-", ce,
605                                                      ce->sha1, ce->ce_mode);
606                                 break;
607                         }
608                         /* We come here with ce pointing at stage 1
609                          * (original tree) and ac[1] pointing at stage
610                          * 3 (unmerged).  show-modified with
611                          * report-missing set to false does not say the
612                          * file is deleted but reports true if work
613                          * tree does not have it, in which case we
614                          * fall through to report the unmerged state.
615                          * Otherwise, we show the differences between
616                          * the original tree and the work tree.
617                          */
618                         if (!cached &&
619                             !show_modified(revs, ce, ac[1], 0,
620                                            cached, match_missing))
621                                 break;
622                         diff_unmerge(&revs->diffopt, ce->name,
623                                      ntohl(ce->ce_mode), ce->sha1);
624                         break;
625                 case 3:
626                         diff_unmerge(&revs->diffopt, ce->name,
627                                      0, null_sha1);
628                         break;
629
630                 default:
631                         die("impossible cache entry stage");
632                 }
633
634 skip_entry:
635                 /*
636                  * Ignore all the different stages for this file,
637                  * we've handled the relevant cases now.
638                  */
639                 do {
640                         ac++;
641                         entries--;
642                 } while (entries && ce_same_name(ce, ac[0]));
643         }
644         return 0;
645 }
646
647 /*
648  * This turns all merge entries into "stage 3". That guarantees that
649  * when we read in the new tree (into "stage 1"), we won't lose sight
650  * of the fact that we had unmerged entries.
651  */
652 static void mark_merge_entries(void)
653 {
654         int i;
655         for (i = 0; i < active_nr; i++) {
656                 struct cache_entry *ce = active_cache[i];
657                 if (!ce_stage(ce))
658                         continue;
659                 ce->ce_flags |= htons(CE_STAGEMASK);
660         }
661 }
662
663 int run_diff_index(struct rev_info *revs, int cached)
664 {
665         int ret;
666         struct object *ent;
667         struct tree *tree;
668         const char *tree_name;
669         int match_missing = 0;
670
671         /*
672          * Backward compatibility wart - "diff-index -m" does
673          * not mean "do not ignore merges", but totally different.
674          */
675         if (!revs->ignore_merges)
676                 match_missing = 1;
677
678         mark_merge_entries();
679
680         ent = revs->pending.objects[0].item;
681         tree_name = revs->pending.objects[0].name;
682         tree = parse_tree_indirect(ent->sha1);
683         if (!tree)
684                 return error("bad tree object %s", tree_name);
685         if (read_tree(tree, 1, revs->prune_data))
686                 return error("unable to read tree object %s", tree_name);
687         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
688                          cached, match_missing);
689         diffcore_std(&revs->diffopt);
690         diff_flush(&revs->diffopt);
691         return ret;
692 }
693
694 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
695 {
696         struct tree *tree;
697         struct rev_info revs;
698         int i;
699         struct cache_entry **dst;
700         struct cache_entry *last = NULL;
701
702         /*
703          * This is used by git-blame to run diff-cache internally;
704          * it potentially needs to repeatedly run this, so we will
705          * start by removing the higher order entries the last round
706          * left behind.
707          */
708         dst = active_cache;
709         for (i = 0; i < active_nr; i++) {
710                 struct cache_entry *ce = active_cache[i];
711                 if (ce_stage(ce)) {
712                         if (last && !strcmp(ce->name, last->name))
713                                 continue;
714                         cache_tree_invalidate_path(active_cache_tree,
715                                                    ce->name);
716                         last = ce;
717                         ce->ce_mode = 0;
718                         ce->ce_flags &= ~htons(CE_STAGEMASK);
719                 }
720                 *dst++ = ce;
721         }
722         active_nr = dst - active_cache;
723
724         init_revisions(&revs, NULL);
725         revs.prune_data = opt->paths;
726         tree = parse_tree_indirect(tree_sha1);
727         if (!tree)
728                 die("bad tree object %s", sha1_to_hex(tree_sha1));
729         if (read_tree(tree, 1, opt->paths))
730                 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
731         return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
732                           1, 0);
733 }