Merge branch 'rs/opt-updates'
[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 (opt->flags.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 = LOCK_INIT;
207         int fd;
208
209         fd = hold_locked_index(&lock_file, 0);
210         if (fd < 0)
211                 return;
212         discard_cache();
213         read_cache();
214         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
215         update_index_if_able(&the_index, &lock_file);
216 }
217
218 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
219 {
220         unsigned int options = 0;
221
222         while (1 < argc && argv[1][0] == '-') {
223                 if (!strcmp(argv[1], "--base"))
224                         revs->max_count = 1;
225                 else if (!strcmp(argv[1], "--ours"))
226                         revs->max_count = 2;
227                 else if (!strcmp(argv[1], "--theirs"))
228                         revs->max_count = 3;
229                 else if (!strcmp(argv[1], "-q"))
230                         options |= DIFF_SILENT_ON_REMOVED;
231                 else if (!strcmp(argv[1], "-h"))
232                         usage(builtin_diff_usage);
233                 else
234                         return error(_("invalid option: %s"), argv[1]);
235                 argv++; argc--;
236         }
237
238         /*
239          * "diff --base" should not combine merges because it was not
240          * asked to.  "diff -c" should not densify (if the user wants
241          * dense one, --cc can be explicitly asked for, or just rely
242          * on the default).
243          */
244         if (revs->max_count == -1 && !revs->combine_merges &&
245             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
246                 revs->combine_merges = revs->dense_combined_merges = 1;
247
248         setup_work_tree();
249         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
250                 perror("read_cache_preload");
251                 return -1;
252         }
253         return run_diff_files(revs, options);
254 }
255
256 int cmd_diff(int argc, const char **argv, const char *prefix)
257 {
258         int i;
259         struct rev_info rev;
260         struct object_array ent = OBJECT_ARRAY_INIT;
261         int blobs = 0, paths = 0;
262         struct object_array_entry *blob[2];
263         int nongit = 0, no_index = 0;
264         int result = 0;
265
266         /*
267          * We could get N tree-ish in the rev.pending_objects list.
268          * Also there could be M blobs there, and P pathspecs.
269          *
270          * N=0, M=0:
271          *      cache vs files (diff-files)
272          * N=0, M=2:
273          *      compare two random blobs.  P must be zero.
274          * N=0, M=1, P=1:
275          *      compare a blob with a working tree file.
276          *
277          * N=1, M=0:
278          *      tree vs cache (diff-index --cached)
279          *
280          * N=2, M=0:
281          *      tree vs tree (diff-tree)
282          *
283          * N=0, M=0, P=2:
284          *      compare two filesystem entities (aka --no-index).
285          *
286          * Other cases are errors.
287          */
288
289         /* Were we asked to do --no-index explicitly? */
290         for (i = 1; i < argc; i++) {
291                 if (!strcmp(argv[i], "--")) {
292                         i++;
293                         break;
294                 }
295                 if (!strcmp(argv[i], "--no-index"))
296                         no_index = DIFF_NO_INDEX_EXPLICIT;
297                 if (argv[i][0] != '-')
298                         break;
299         }
300
301         prefix = setup_git_directory_gently(&nongit);
302
303         if (!no_index) {
304                 /*
305                  * Treat git diff with at least one path outside of the
306                  * repo the same as if the command would have been executed
307                  * outside of a git repository.  In this case it behaves
308                  * the same way as "git diff --no-index <a> <b>", which acts
309                  * as a colourful "diff" replacement.
310                  */
311                 if (nongit || ((argc == i + 2) &&
312                                (!path_inside_repo(prefix, argv[i]) ||
313                                 !path_inside_repo(prefix, argv[i + 1]))))
314                         no_index = DIFF_NO_INDEX_IMPLICIT;
315         }
316
317         init_diff_ui_defaults();
318         git_config(git_diff_ui_config, NULL);
319         precompose_argv(argc, argv);
320
321         init_revisions(&rev, prefix);
322
323         if (no_index && argc != i + 2) {
324                 if (no_index == DIFF_NO_INDEX_IMPLICIT) {
325                         /*
326                          * There was no --no-index and there were not two
327                          * paths. It is possible that the user intended
328                          * to do an inside-repository operation.
329                          */
330                         fprintf(stderr, "Not a git repository\n");
331                         fprintf(stderr,
332                                 "To compare two paths outside a working tree:\n");
333                 }
334                 /* Give the usage message for non-repository usage and exit. */
335                 usagef("git diff %s <path> <path>",
336                        no_index == DIFF_NO_INDEX_EXPLICIT ?
337                        "--no-index" : "[--no-index]");
338
339         }
340         if (no_index)
341                 /* If this is a no-index diff, just run it and exit there. */
342                 diff_no_index(&rev, argc, argv);
343
344         /* Otherwise, we are doing the usual "git" diff */
345         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
346
347         /* Scale to real terminal size and respect statGraphWidth config */
348         rev.diffopt.stat_width = -1;
349         rev.diffopt.stat_graph_width = -1;
350
351         /* Default to let external and textconv be used */
352         rev.diffopt.flags.allow_external = 1;
353         rev.diffopt.flags.allow_textconv = 1;
354
355         /*
356          * Default to intent-to-add entries invisible in the
357          * index. This makes them show up as new files in diff-files
358          * and not at all in diff-cached.
359          */
360         rev.diffopt.ita_invisible_in_index = 1;
361
362         if (nongit)
363                 die(_("Not a git repository"));
364         argc = setup_revisions(argc, argv, &rev, NULL);
365         if (!rev.diffopt.output_format) {
366                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
367                 diff_setup_done(&rev.diffopt);
368         }
369
370         rev.diffopt.flags.recursive = 1;
371
372         setup_diff_pager(&rev.diffopt);
373
374         /*
375          * Do we have --cached and not have a pending object, then
376          * default to HEAD by hand.  Eek.
377          */
378         if (!rev.pending.nr) {
379                 int i;
380                 for (i = 1; i < argc; i++) {
381                         const char *arg = argv[i];
382                         if (!strcmp(arg, "--"))
383                                 break;
384                         else if (!strcmp(arg, "--cached") ||
385                                  !strcmp(arg, "--staged")) {
386                                 add_head_to_pending(&rev);
387                                 if (!rev.pending.nr) {
388                                         struct tree *tree;
389                                         tree = lookup_tree(the_repository,
390                                                            the_repository->hash_algo->empty_tree);
391                                         add_pending_object(&rev, &tree->object, "HEAD");
392                                 }
393                                 break;
394                         }
395                 }
396         }
397
398         for (i = 0; i < rev.pending.nr; i++) {
399                 struct object_array_entry *entry = &rev.pending.objects[i];
400                 struct object *obj = entry->item;
401                 const char *name = entry->name;
402                 int flags = (obj->flags & UNINTERESTING);
403                 if (!obj->parsed)
404                         obj = parse_object(the_repository, &obj->oid);
405                 obj = deref_tag(the_repository, obj, NULL, 0);
406                 if (!obj)
407                         die(_("invalid object '%s' given."), name);
408                 if (obj->type == OBJ_COMMIT)
409                         obj = &get_commit_tree(((struct commit *)obj))->object;
410
411                 if (obj->type == OBJ_TREE) {
412                         obj->flags |= flags;
413                         add_object_array(obj, name, &ent);
414                 } else if (obj->type == OBJ_BLOB) {
415                         if (2 <= blobs)
416                                 die(_("more than two blobs given: '%s'"), name);
417                         blob[blobs] = entry;
418                         blobs++;
419
420                 } else {
421                         die(_("unhandled object '%s' given."), name);
422                 }
423         }
424         if (rev.prune_data.nr)
425                 paths += rev.prune_data.nr;
426
427         /*
428          * Now, do the arguments look reasonable?
429          */
430         if (!ent.nr) {
431                 switch (blobs) {
432                 case 0:
433                         result = builtin_diff_files(&rev, argc, argv);
434                         break;
435                 case 1:
436                         if (paths != 1)
437                                 usage(builtin_diff_usage);
438                         result = builtin_diff_b_f(&rev, argc, argv, blob);
439                         break;
440                 case 2:
441                         if (paths)
442                                 usage(builtin_diff_usage);
443                         result = builtin_diff_blobs(&rev, argc, argv, blob);
444                         break;
445                 default:
446                         usage(builtin_diff_usage);
447                 }
448         }
449         else if (blobs)
450                 usage(builtin_diff_usage);
451         else if (ent.nr == 1)
452                 result = builtin_diff_index(&rev, argc, argv);
453         else if (ent.nr == 2)
454                 result = builtin_diff_tree(&rev, argc, argv,
455                                            &ent.objects[0], &ent.objects[1]);
456         else if (ent.objects[0].item->flags & UNINTERESTING) {
457                 /*
458                  * diff A...B where there is at least one merge base
459                  * between A and B.  We have ent.objects[0] ==
460                  * merge-base, ent.objects[ents-2] == A, and
461                  * ent.objects[ents-1] == B.  Show diff between the
462                  * base and B.  Note that we pick one merge base at
463                  * random if there are more than one.
464                  */
465                 result = builtin_diff_tree(&rev, argc, argv,
466                                            &ent.objects[0],
467                                            &ent.objects[ent.nr-1]);
468         } else
469                 result = builtin_diff_combined(&rev, argc, argv,
470                                                ent.objects, ent.nr);
471         result = diff_result_code(&rev.diffopt, result);
472         if (1 < rev.diffopt.skip_stat_unmatch)
473                 refresh_index_quietly();
474         UNLEAK(rev);
475         UNLEAK(ent);
476         UNLEAK(blob);
477         return result;
478 }