Merge branch 'js/rebase-i-final'
[git] / builtin / diff.c
1 /*
2  * Builtin "git diff"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #include "cache.h"
7 #include "config.h"
8 #include "lockfile.h"
9 #include "color.h"
10 #include "commit.h"
11 #include "blob.h"
12 #include "tag.h"
13 #include "diff.h"
14 #include "diffcore.h"
15 #include "revision.h"
16 #include "log-tree.h"
17 #include "builtin.h"
18 #include "submodule.h"
19 #include "sha1-array.h"
20
21 #define DIFF_NO_INDEX_EXPLICIT 1
22 #define DIFF_NO_INDEX_IMPLICIT 2
23
24 static const char builtin_diff_usage[] =
25 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
26
27 static const char *blob_path(struct object_array_entry *entry)
28 {
29         return entry->path ? entry->path : entry->name;
30 }
31
32 static void stuff_change(struct diff_options *opt,
33                          unsigned old_mode, unsigned new_mode,
34                          const struct object_id *old_oid,
35                          const struct object_id *new_oid,
36                          int old_oid_valid,
37                          int new_oid_valid,
38                          const char *old_path,
39                          const char *new_path)
40 {
41         struct diff_filespec *one, *two;
42
43         if (!is_null_oid(old_oid) && !is_null_oid(new_oid) &&
44             !oidcmp(old_oid, new_oid) && (old_mode == new_mode))
45                 return;
46
47         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
48                 SWAP(old_mode, new_mode);
49                 SWAP(old_oid, new_oid);
50                 SWAP(old_path, new_path);
51         }
52
53         if (opt->prefix &&
54             (strncmp(old_path, opt->prefix, opt->prefix_length) ||
55              strncmp(new_path, opt->prefix, opt->prefix_length)))
56                 return;
57
58         one = alloc_filespec(old_path);
59         two = alloc_filespec(new_path);
60         fill_filespec(one, old_oid, old_oid_valid, old_mode);
61         fill_filespec(two, new_oid, new_oid_valid, new_mode);
62
63         diff_queue(&diff_queued_diff, one, two);
64 }
65
66 static int builtin_diff_b_f(struct rev_info *revs,
67                             int argc, const char **argv,
68                             struct object_array_entry **blob)
69 {
70         /* Blob vs file in the working tree*/
71         struct stat st;
72         const char *path;
73
74         if (argc > 1)
75                 usage(builtin_diff_usage);
76
77         GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
78         path = revs->prune_data.items[0].match;
79
80         if (lstat(path, &st))
81                 die_errno(_("failed to stat '%s'"), path);
82         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
83                 die(_("'%s': not a regular file or symlink"), path);
84
85         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
86
87         if (blob[0]->mode == S_IFINVALID)
88                 blob[0]->mode = canon_mode(st.st_mode);
89
90         stuff_change(&revs->diffopt,
91                      blob[0]->mode, canon_mode(st.st_mode),
92                      &blob[0]->item->oid, &null_oid,
93                      1, 0,
94                      blob[0]->path ? blob[0]->path : path,
95                      path);
96         diffcore_std(&revs->diffopt);
97         diff_flush(&revs->diffopt);
98         return 0;
99 }
100
101 static int builtin_diff_blobs(struct rev_info *revs,
102                               int argc, const char **argv,
103                               struct object_array_entry **blob)
104 {
105         unsigned mode = canon_mode(S_IFREG | 0644);
106
107         if (argc > 1)
108                 usage(builtin_diff_usage);
109
110         if (blob[0]->mode == S_IFINVALID)
111                 blob[0]->mode = mode;
112
113         if (blob[1]->mode == S_IFINVALID)
114                 blob[1]->mode = mode;
115
116         stuff_change(&revs->diffopt,
117                      blob[0]->mode, blob[1]->mode,
118                      &blob[0]->item->oid, &blob[1]->item->oid,
119                      1, 1,
120                      blob_path(blob[0]), blob_path(blob[1]));
121         diffcore_std(&revs->diffopt);
122         diff_flush(&revs->diffopt);
123         return 0;
124 }
125
126 static int builtin_diff_index(struct rev_info *revs,
127                               int argc, const char **argv)
128 {
129         int cached = 0;
130         while (1 < argc) {
131                 const char *arg = argv[1];
132                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
133                         cached = 1;
134                 else
135                         usage(builtin_diff_usage);
136                 argv++; argc--;
137         }
138         /*
139          * Make sure there is one revision (i.e. pending object),
140          * and there is no revision filtering parameters.
141          */
142         if (revs->pending.nr != 1 ||
143             revs->max_count != -1 || revs->min_age != -1 ||
144             revs->max_age != -1)
145                 usage(builtin_diff_usage);
146         if (!cached) {
147                 setup_work_tree();
148                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
149                         perror("read_cache_preload");
150                         return -1;
151                 }
152         } else if (read_cache() < 0) {
153                 perror("read_cache");
154                 return -1;
155         }
156         return run_diff_index(revs, cached);
157 }
158
159 static int builtin_diff_tree(struct rev_info *revs,
160                              int argc, const char **argv,
161                              struct object_array_entry *ent0,
162                              struct object_array_entry *ent1)
163 {
164         const struct object_id *(oid[2]);
165         int swap = 0;
166
167         if (argc > 1)
168                 usage(builtin_diff_usage);
169
170         /*
171          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
172          * swap them.
173          */
174         if (ent1->item->flags & UNINTERESTING)
175                 swap = 1;
176         oid[swap] = &ent0->item->oid;
177         oid[1 - swap] = &ent1->item->oid;
178         diff_tree_oid(oid[0], oid[1], "", &revs->diffopt);
179         log_tree_diff_flush(revs);
180         return 0;
181 }
182
183 static int builtin_diff_combined(struct rev_info *revs,
184                                  int argc, const char **argv,
185                                  struct object_array_entry *ent,
186                                  int ents)
187 {
188         struct oid_array parents = OID_ARRAY_INIT;
189         int i;
190
191         if (argc > 1)
192                 usage(builtin_diff_usage);
193
194         if (!revs->dense_combined_merges && !revs->combine_merges)
195                 revs->dense_combined_merges = revs->combine_merges = 1;
196         for (i = 1; i < ents; i++)
197                 oid_array_append(&parents, &ent[i].item->oid);
198         diff_tree_combined(&ent[0].item->oid, &parents,
199                            revs->dense_combined_merges, revs);
200         oid_array_clear(&parents);
201         return 0;
202 }
203
204 static void refresh_index_quietly(void)
205 {
206         struct lock_file *lock_file;
207         int fd;
208
209         lock_file = xcalloc(1, sizeof(struct lock_file));
210         fd = hold_locked_index(lock_file, 0);
211         if (fd < 0)
212                 return;
213         discard_cache();
214         read_cache();
215         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
216         update_index_if_able(&the_index, lock_file);
217 }
218
219 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
220 {
221         unsigned int options = 0;
222
223         while (1 < argc && argv[1][0] == '-') {
224                 if (!strcmp(argv[1], "--base"))
225                         revs->max_count = 1;
226                 else if (!strcmp(argv[1], "--ours"))
227                         revs->max_count = 2;
228                 else if (!strcmp(argv[1], "--theirs"))
229                         revs->max_count = 3;
230                 else if (!strcmp(argv[1], "-q"))
231                         options |= DIFF_SILENT_ON_REMOVED;
232                 else if (!strcmp(argv[1], "-h"))
233                         usage(builtin_diff_usage);
234                 else
235                         return error(_("invalid option: %s"), argv[1]);
236                 argv++; argc--;
237         }
238
239         /*
240          * "diff --base" should not combine merges because it was not
241          * asked to.  "diff -c" should not densify (if the user wants
242          * dense one, --cc can be explicitly asked for, or just rely
243          * on the default).
244          */
245         if (revs->max_count == -1 && !revs->combine_merges &&
246             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
247                 revs->combine_merges = revs->dense_combined_merges = 1;
248
249         setup_work_tree();
250         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
251                 perror("read_cache_preload");
252                 return -1;
253         }
254         return run_diff_files(revs, options);
255 }
256
257 int cmd_diff(int argc, const char **argv, const char *prefix)
258 {
259         int i;
260         struct rev_info rev;
261         struct object_array ent = OBJECT_ARRAY_INIT;
262         int blobs = 0, paths = 0;
263         struct object_array_entry *blob[2];
264         int nongit = 0, no_index = 0;
265         int result = 0;
266
267         /*
268          * We could get N tree-ish in the rev.pending_objects list.
269          * Also there could be M blobs there, and P pathspecs.
270          *
271          * N=0, M=0:
272          *      cache vs files (diff-files)
273          * N=0, M=2:
274          *      compare two random blobs.  P must be zero.
275          * N=0, M=1, P=1:
276          *      compare a blob with a working tree file.
277          *
278          * N=1, M=0:
279          *      tree vs cache (diff-index --cached)
280          *
281          * N=2, M=0:
282          *      tree vs tree (diff-tree)
283          *
284          * N=0, M=0, P=2:
285          *      compare two filesystem entities (aka --no-index).
286          *
287          * Other cases are errors.
288          */
289
290         /* Were we asked to do --no-index explicitly? */
291         for (i = 1; i < argc; i++) {
292                 if (!strcmp(argv[i], "--")) {
293                         i++;
294                         break;
295                 }
296                 if (!strcmp(argv[i], "--no-index"))
297                         no_index = DIFF_NO_INDEX_EXPLICIT;
298                 if (argv[i][0] != '-')
299                         break;
300         }
301
302         prefix = setup_git_directory_gently(&nongit);
303
304         if (!no_index) {
305                 /*
306                  * Treat git diff with at least one path outside of the
307                  * repo the same as if the command would have been executed
308                  * outside of a git repository.  In this case it behaves
309                  * the same way as "git diff --no-index <a> <b>", which acts
310                  * as a colourful "diff" replacement.
311                  */
312                 if (nongit || ((argc == i + 2) &&
313                                (!path_inside_repo(prefix, argv[i]) ||
314                                 !path_inside_repo(prefix, argv[i + 1]))))
315                         no_index = DIFF_NO_INDEX_IMPLICIT;
316         }
317
318         init_diff_ui_defaults();
319         git_config(git_diff_ui_config, NULL);
320         precompose_argv(argc, argv);
321
322         init_revisions(&rev, prefix);
323
324         if (no_index && argc != i + 2) {
325                 if (no_index == DIFF_NO_INDEX_IMPLICIT) {
326                         /*
327                          * There was no --no-index and there were not two
328                          * paths. It is possible that the user intended
329                          * to do an inside-repository operation.
330                          */
331                         fprintf(stderr, "Not a git repository\n");
332                         fprintf(stderr,
333                                 "To compare two paths outside a working tree:\n");
334                 }
335                 /* Give the usage message for non-repository usage and exit. */
336                 usagef("git diff %s <path> <path>",
337                        no_index == DIFF_NO_INDEX_EXPLICIT ?
338                        "--no-index" : "[--no-index]");
339
340         }
341         if (no_index)
342                 /* If this is a no-index diff, just run it and exit there. */
343                 diff_no_index(&rev, argc, argv);
344
345         /* Otherwise, we are doing the usual "git" diff */
346         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
347
348         /* Scale to real terminal size and respect statGraphWidth config */
349         rev.diffopt.stat_width = -1;
350         rev.diffopt.stat_graph_width = -1;
351
352         /* Default to let external and textconv be used */
353         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
354         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
355
356         if (nongit)
357                 die(_("Not a git repository"));
358         argc = setup_revisions(argc, argv, &rev, NULL);
359         if (!rev.diffopt.output_format) {
360                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
361                 diff_setup_done(&rev.diffopt);
362         }
363
364         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
365
366         setup_diff_pager(&rev.diffopt);
367
368         /*
369          * Do we have --cached and not have a pending object, then
370          * default to HEAD by hand.  Eek.
371          */
372         if (!rev.pending.nr) {
373                 int i;
374                 for (i = 1; i < argc; i++) {
375                         const char *arg = argv[i];
376                         if (!strcmp(arg, "--"))
377                                 break;
378                         else if (!strcmp(arg, "--cached") ||
379                                  !strcmp(arg, "--staged")) {
380                                 add_head_to_pending(&rev);
381                                 if (!rev.pending.nr) {
382                                         struct tree *tree;
383                                         tree = lookup_tree(&empty_tree_oid);
384                                         add_pending_object(&rev, &tree->object, "HEAD");
385                                 }
386                                 break;
387                         }
388                 }
389         }
390
391         for (i = 0; i < rev.pending.nr; i++) {
392                 struct object_array_entry *entry = &rev.pending.objects[i];
393                 struct object *obj = entry->item;
394                 const char *name = entry->name;
395                 int flags = (obj->flags & UNINTERESTING);
396                 if (!obj->parsed)
397                         obj = parse_object(&obj->oid);
398                 obj = deref_tag(obj, NULL, 0);
399                 if (!obj)
400                         die(_("invalid object '%s' given."), name);
401                 if (obj->type == OBJ_COMMIT)
402                         obj = &((struct commit *)obj)->tree->object;
403
404                 if (obj->type == OBJ_TREE) {
405                         obj->flags |= flags;
406                         add_object_array(obj, name, &ent);
407                 } else if (obj->type == OBJ_BLOB) {
408                         if (2 <= blobs)
409                                 die(_("more than two blobs given: '%s'"), name);
410                         blob[blobs] = entry;
411                         blobs++;
412
413                 } else {
414                         die(_("unhandled object '%s' given."), name);
415                 }
416         }
417         if (rev.prune_data.nr)
418                 paths += rev.prune_data.nr;
419
420         /*
421          * Now, do the arguments look reasonable?
422          */
423         if (!ent.nr) {
424                 switch (blobs) {
425                 case 0:
426                         result = builtin_diff_files(&rev, argc, argv);
427                         break;
428                 case 1:
429                         if (paths != 1)
430                                 usage(builtin_diff_usage);
431                         result = builtin_diff_b_f(&rev, argc, argv, blob);
432                         break;
433                 case 2:
434                         if (paths)
435                                 usage(builtin_diff_usage);
436                         result = builtin_diff_blobs(&rev, argc, argv, blob);
437                         break;
438                 default:
439                         usage(builtin_diff_usage);
440                 }
441         }
442         else if (blobs)
443                 usage(builtin_diff_usage);
444         else if (ent.nr == 1)
445                 result = builtin_diff_index(&rev, argc, argv);
446         else if (ent.nr == 2)
447                 result = builtin_diff_tree(&rev, argc, argv,
448                                            &ent.objects[0], &ent.objects[1]);
449         else if (ent.objects[0].item->flags & UNINTERESTING) {
450                 /*
451                  * diff A...B where there is at least one merge base
452                  * between A and B.  We have ent.objects[0] ==
453                  * merge-base, ent.objects[ents-2] == A, and
454                  * ent.objects[ents-1] == B.  Show diff between the
455                  * base and B.  Note that we pick one merge base at
456                  * random if there are more than one.
457                  */
458                 result = builtin_diff_tree(&rev, argc, argv,
459                                            &ent.objects[0],
460                                            &ent.objects[ent.nr-1]);
461         } else
462                 result = builtin_diff_combined(&rev, argc, argv,
463                                                ent.objects, ent.nr);
464         result = diff_result_code(&rev.diffopt, result);
465         if (1 < rev.diffopt.skip_stat_unmatch)
466                 refresh_index_quietly();
467         UNLEAK(rev);
468         UNLEAK(ent);
469         UNLEAK(blob);
470         return result;
471 }