Merge branch 'ep/avoid-test-a-o'
[git] / builtin / diff.c
1 /*
2  * Builtin "git diff"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #include "cache.h"
7 #include "color.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "tag.h"
11 #include "diff.h"
12 #include "diffcore.h"
13 #include "revision.h"
14 #include "log-tree.h"
15 #include "builtin.h"
16 #include "submodule.h"
17 #include "sha1-array.h"
18
19 #define DIFF_NO_INDEX_EXPLICIT 1
20 #define DIFF_NO_INDEX_IMPLICIT 2
21
22 struct blobinfo {
23         unsigned char sha1[20];
24         const char *name;
25         unsigned mode;
26 };
27
28 static const char builtin_diff_usage[] =
29 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
30
31 static void stuff_change(struct diff_options *opt,
32                          unsigned old_mode, unsigned new_mode,
33                          const unsigned char *old_sha1,
34                          const unsigned char *new_sha1,
35                          int old_sha1_valid,
36                          int new_sha1_valid,
37                          const char *old_name,
38                          const char *new_name)
39 {
40         struct diff_filespec *one, *two;
41
42         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
43             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
44                 return;
45
46         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
47                 unsigned tmp;
48                 const unsigned char *tmp_u;
49                 const char *tmp_c;
50                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
51                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
52                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
53         }
54
55         if (opt->prefix &&
56             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
57              strncmp(new_name, opt->prefix, opt->prefix_length)))
58                 return;
59
60         one = alloc_filespec(old_name);
61         two = alloc_filespec(new_name);
62         fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
63         fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
64
65         diff_queue(&diff_queued_diff, one, two);
66 }
67
68 static int builtin_diff_b_f(struct rev_info *revs,
69                             int argc, const char **argv,
70                             struct blobinfo *blob)
71 {
72         /* Blob vs file in the working tree*/
73         struct stat st;
74         const char *path;
75
76         if (argc > 1)
77                 usage(builtin_diff_usage);
78
79         GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
80         path = revs->prune_data.items[0].match;
81
82         if (lstat(path, &st))
83                 die_errno(_("failed to stat '%s'"), path);
84         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
85                 die(_("'%s': not a regular file or symlink"), path);
86
87         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
88
89         if (blob[0].mode == S_IFINVALID)
90                 blob[0].mode = canon_mode(st.st_mode);
91
92         stuff_change(&revs->diffopt,
93                      blob[0].mode, canon_mode(st.st_mode),
94                      blob[0].sha1, null_sha1,
95                      1, 0,
96                      path, path);
97         diffcore_std(&revs->diffopt);
98         diff_flush(&revs->diffopt);
99         return 0;
100 }
101
102 static int builtin_diff_blobs(struct rev_info *revs,
103                               int argc, const char **argv,
104                               struct blobinfo *blob)
105 {
106         unsigned mode = canon_mode(S_IFREG | 0644);
107
108         if (argc > 1)
109                 usage(builtin_diff_usage);
110
111         if (blob[0].mode == S_IFINVALID)
112                 blob[0].mode = mode;
113
114         if (blob[1].mode == S_IFINVALID)
115                 blob[1].mode = mode;
116
117         stuff_change(&revs->diffopt,
118                      blob[0].mode, blob[1].mode,
119                      blob[0].sha1, blob[1].sha1,
120                      1, 1,
121                      blob[0].name, blob[1].name);
122         diffcore_std(&revs->diffopt);
123         diff_flush(&revs->diffopt);
124         return 0;
125 }
126
127 static int builtin_diff_index(struct rev_info *revs,
128                               int argc, const char **argv)
129 {
130         int cached = 0;
131         while (1 < argc) {
132                 const char *arg = argv[1];
133                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
134                         cached = 1;
135                 else
136                         usage(builtin_diff_usage);
137                 argv++; argc--;
138         }
139         /*
140          * Make sure there is one revision (i.e. pending object),
141          * and there is no revision filtering parameters.
142          */
143         if (revs->pending.nr != 1 ||
144             revs->max_count != -1 || revs->min_age != -1 ||
145             revs->max_age != -1)
146                 usage(builtin_diff_usage);
147         if (!cached) {
148                 setup_work_tree();
149                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
150                         perror("read_cache_preload");
151                         return -1;
152                 }
153         } else if (read_cache() < 0) {
154                 perror("read_cache");
155                 return -1;
156         }
157         return run_diff_index(revs, cached);
158 }
159
160 static int builtin_diff_tree(struct rev_info *revs,
161                              int argc, const char **argv,
162                              struct object_array_entry *ent0,
163                              struct object_array_entry *ent1)
164 {
165         const unsigned char *(sha1[2]);
166         int swap = 0;
167
168         if (argc > 1)
169                 usage(builtin_diff_usage);
170
171         /*
172          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
173          * swap them.
174          */
175         if (ent1->item->flags & UNINTERESTING)
176                 swap = 1;
177         sha1[swap] = ent0->item->sha1;
178         sha1[1 - swap] = ent1->item->sha1;
179         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
180         log_tree_diff_flush(revs);
181         return 0;
182 }
183
184 static int builtin_diff_combined(struct rev_info *revs,
185                                  int argc, const char **argv,
186                                  struct object_array_entry *ent,
187                                  int ents)
188 {
189         struct sha1_array parents = SHA1_ARRAY_INIT;
190         int i;
191
192         if (argc > 1)
193                 usage(builtin_diff_usage);
194
195         if (!revs->dense_combined_merges && !revs->combine_merges)
196                 revs->dense_combined_merges = revs->combine_merges = 1;
197         for (i = 1; i < ents; i++)
198                 sha1_array_append(&parents, ent[i].item->sha1);
199         diff_tree_combined(ent[0].item->sha1, &parents,
200                            revs->dense_combined_merges, revs);
201         sha1_array_clear(&parents);
202         return 0;
203 }
204
205 static void refresh_index_quietly(void)
206 {
207         struct lock_file *lock_file;
208         int fd;
209
210         lock_file = xcalloc(1, sizeof(struct lock_file));
211         fd = hold_locked_index(lock_file, 0);
212         if (fd < 0)
213                 return;
214         discard_cache();
215         read_cache();
216         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
217         update_index_if_able(&the_index, lock_file);
218 }
219
220 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
221 {
222         unsigned int options = 0;
223
224         while (1 < argc && argv[1][0] == '-') {
225                 if (!strcmp(argv[1], "--base"))
226                         revs->max_count = 1;
227                 else if (!strcmp(argv[1], "--ours"))
228                         revs->max_count = 2;
229                 else if (!strcmp(argv[1], "--theirs"))
230                         revs->max_count = 3;
231                 else if (!strcmp(argv[1], "-q"))
232                         options |= DIFF_SILENT_ON_REMOVED;
233                 else if (!strcmp(argv[1], "-h"))
234                         usage(builtin_diff_usage);
235                 else
236                         return error(_("invalid option: %s"), argv[1]);
237                 argv++; argc--;
238         }
239
240         /*
241          * "diff --base" should not combine merges because it was not
242          * asked to.  "diff -c" should not densify (if the user wants
243          * dense one, --cc can be explicitly asked for, or just rely
244          * on the default).
245          */
246         if (revs->max_count == -1 && !revs->combine_merges &&
247             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
248                 revs->combine_merges = revs->dense_combined_merges = 1;
249
250         setup_work_tree();
251         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
252                 perror("read_cache_preload");
253                 return -1;
254         }
255         return run_diff_files(revs, options);
256 }
257
258 int cmd_diff(int argc, const char **argv, const char *prefix)
259 {
260         int i;
261         struct rev_info rev;
262         struct object_array ent = OBJECT_ARRAY_INIT;
263         int blobs = 0, paths = 0;
264         struct blobinfo blob[2];
265         int nongit = 0, no_index = 0;
266         int result = 0;
267
268         /*
269          * We could get N tree-ish in the rev.pending_objects list.
270          * Also there could be M blobs there, and P pathspecs.
271          *
272          * N=0, M=0:
273          *      cache vs files (diff-files)
274          * N=0, M=2:
275          *      compare two random blobs.  P must be zero.
276          * N=0, M=1, P=1:
277          *      compare a blob with a working tree file.
278          *
279          * N=1, M=0:
280          *      tree vs cache (diff-index --cached)
281          *
282          * N=2, M=0:
283          *      tree vs tree (diff-tree)
284          *
285          * N=0, M=0, P=2:
286          *      compare two filesystem entities (aka --no-index).
287          *
288          * Other cases are errors.
289          */
290
291         /* Were we asked to do --no-index explicitly? */
292         for (i = 1; i < argc; i++) {
293                 if (!strcmp(argv[i], "--")) {
294                         i++;
295                         break;
296                 }
297                 if (!strcmp(argv[i], "--no-index"))
298                         no_index = DIFF_NO_INDEX_EXPLICIT;
299                 if (argv[i][0] != '-')
300                         break;
301         }
302
303         if (!no_index)
304                 prefix = setup_git_directory_gently(&nongit);
305
306         /*
307          * Treat git diff with at least one path outside of the
308          * repo the same as if the command would have been executed
309          * outside of a git repository.  In this case it behaves
310          * the same way as "git diff --no-index <a> <b>", which acts
311          * as a colourful "diff" replacement.
312          */
313         if (nongit || ((argc == i + 2) &&
314                        (!path_inside_repo(prefix, argv[i]) ||
315                         !path_inside_repo(prefix, argv[i + 1]))))
316                 no_index = DIFF_NO_INDEX_IMPLICIT;
317
318         if (!no_index)
319                 gitmodules_config();
320         git_config(git_diff_ui_config, NULL);
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, prefix);
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_SHA1_BIN);
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->sha1);
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                         hashcpy(blob[blobs].sha1, obj->sha1);
411                         blob[blobs].name = name;
412                         blob[blobs].mode = entry->mode;
413                         blobs++;
414
415                 } else {
416                         die(_("unhandled object '%s' given."), name);
417                 }
418         }
419         if (rev.prune_data.nr)
420                 paths += rev.prune_data.nr;
421
422         /*
423          * Now, do the arguments look reasonable?
424          */
425         if (!ent.nr) {
426                 switch (blobs) {
427                 case 0:
428                         result = builtin_diff_files(&rev, argc, argv);
429                         break;
430                 case 1:
431                         if (paths != 1)
432                                 usage(builtin_diff_usage);
433                         result = builtin_diff_b_f(&rev, argc, argv, blob);
434                         break;
435                 case 2:
436                         if (paths)
437                                 usage(builtin_diff_usage);
438                         result = builtin_diff_blobs(&rev, argc, argv, blob);
439                         break;
440                 default:
441                         usage(builtin_diff_usage);
442                 }
443         }
444         else if (blobs)
445                 usage(builtin_diff_usage);
446         else if (ent.nr == 1)
447                 result = builtin_diff_index(&rev, argc, argv);
448         else if (ent.nr == 2)
449                 result = builtin_diff_tree(&rev, argc, argv,
450                                            &ent.objects[0], &ent.objects[1]);
451         else if (ent.objects[0].item->flags & UNINTERESTING) {
452                 /*
453                  * diff A...B where there is at least one merge base
454                  * between A and B.  We have ent.objects[0] ==
455                  * merge-base, ent.objects[ents-2] == A, and
456                  * ent.objects[ents-1] == B.  Show diff between the
457                  * base and B.  Note that we pick one merge base at
458                  * random if there are more than one.
459                  */
460                 result = builtin_diff_tree(&rev, argc, argv,
461                                            &ent.objects[0],
462                                            &ent.objects[ent.nr-1]);
463         } else
464                 result = builtin_diff_combined(&rev, argc, argv,
465                                                ent.objects, ent.nr);
466         result = diff_result_code(&rev.diffopt, result);
467         if (1 < rev.diffopt.skip_stat_unmatch)
468                 refresh_index_quietly();
469         return result;
470 }