Merge git://git.kernel.org/pub/scm/gitk/gitk
[git] / builtin-diff.c
1 /*
2  * Builtin "git diff"
3  *
4  * Copyright (c) 2006 Junio C Hamano
5  */
6 #include "cache.h"
7 #include "commit.h"
8 #include "blob.h"
9 #include "tag.h"
10 #include "diff.h"
11 #include "diffcore.h"
12 #include "revision.h"
13 #include "log-tree.h"
14 #include "builtin.h"
15
16 struct blobinfo {
17         unsigned char sha1[20];
18         const char *name;
19         unsigned mode;
20 };
21
22 static const char builtin_diff_usage[] =
23 "git-diff <options> <rev>{0,2} -- <path>*";
24
25 static void stuff_change(struct diff_options *opt,
26                          unsigned old_mode, unsigned new_mode,
27                          const unsigned char *old_sha1,
28                          const unsigned char *new_sha1,
29                          const char *old_name,
30                          const char *new_name)
31 {
32         struct diff_filespec *one, *two;
33
34         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
35             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
36                 return;
37
38         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
39                 unsigned tmp;
40                 const unsigned char *tmp_u;
41                 const char *tmp_c;
42                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
43                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
44                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
45         }
46         one = alloc_filespec(old_name);
47         two = alloc_filespec(new_name);
48         fill_filespec(one, old_sha1, old_mode);
49         fill_filespec(two, new_sha1, new_mode);
50
51         /* NEEDSWORK: shouldn't this part of diffopt??? */
52         diff_queue(&diff_queued_diff, one, two);
53 }
54
55 static int builtin_diff_b_f(struct rev_info *revs,
56                             int argc, const char **argv,
57                             struct blobinfo *blob,
58                             const char *path)
59 {
60         /* Blob vs file in the working tree*/
61         struct stat st;
62
63         if (argc > 1)
64                 usage(builtin_diff_usage);
65
66         if (lstat(path, &st))
67                 die("'%s': %s", path, strerror(errno));
68         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
69                 die("'%s': not a regular file or symlink", path);
70
71         if (blob[0].mode == S_IFINVALID)
72                 blob[0].mode = canon_mode(st.st_mode);
73
74         stuff_change(&revs->diffopt,
75                      blob[0].mode, canon_mode(st.st_mode),
76                      blob[0].sha1, null_sha1,
77                      path, path);
78         diffcore_std(&revs->diffopt);
79         diff_flush(&revs->diffopt);
80         return 0;
81 }
82
83 static int builtin_diff_blobs(struct rev_info *revs,
84                               int argc, const char **argv,
85                               struct blobinfo *blob)
86 {
87         unsigned mode = canon_mode(S_IFREG | 0644);
88
89         if (argc > 1)
90                 usage(builtin_diff_usage);
91
92         if (blob[0].mode == S_IFINVALID)
93                 blob[0].mode = mode;
94
95         if (blob[1].mode == S_IFINVALID)
96                 blob[1].mode = mode;
97
98         stuff_change(&revs->diffopt,
99                      blob[0].mode, blob[1].mode,
100                      blob[0].sha1, blob[1].sha1,
101                      blob[0].name, blob[1].name);
102         diffcore_std(&revs->diffopt);
103         diff_flush(&revs->diffopt);
104         return 0;
105 }
106
107 static int builtin_diff_index(struct rev_info *revs,
108                               int argc, const char **argv)
109 {
110         int cached = 0;
111         while (1 < argc) {
112                 const char *arg = argv[1];
113                 if (!strcmp(arg, "--cached"))
114                         cached = 1;
115                 else
116                         usage(builtin_diff_usage);
117                 argv++; argc--;
118         }
119         /*
120          * Make sure there is one revision (i.e. pending object),
121          * and there is no revision filtering parameters.
122          */
123         if (revs->pending.nr != 1 ||
124             revs->max_count != -1 || revs->min_age != -1 ||
125             revs->max_age != -1)
126                 usage(builtin_diff_usage);
127         if (read_cache() < 0) {
128                 perror("read_cache");
129                 return -1;
130         }
131         return run_diff_index(revs, cached);
132 }
133
134 static int builtin_diff_tree(struct rev_info *revs,
135                              int argc, const char **argv,
136                              struct object_array_entry *ent)
137 {
138         const unsigned char *(sha1[2]);
139         int swap = 0;
140
141         if (argc > 1)
142                 usage(builtin_diff_usage);
143
144         /* We saw two trees, ent[0] and ent[1].
145          * if ent[1] is uninteresting, they are swapped
146          */
147         if (ent[1].item->flags & UNINTERESTING)
148                 swap = 1;
149         sha1[swap] = ent[0].item->sha1;
150         sha1[1-swap] = ent[1].item->sha1;
151         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
152         log_tree_diff_flush(revs);
153         return 0;
154 }
155
156 static int builtin_diff_combined(struct rev_info *revs,
157                                  int argc, const char **argv,
158                                  struct object_array_entry *ent,
159                                  int ents)
160 {
161         const unsigned char (*parent)[20];
162         int i;
163
164         if (argc > 1)
165                 usage(builtin_diff_usage);
166
167         if (!revs->dense_combined_merges && !revs->combine_merges)
168                 revs->dense_combined_merges = revs->combine_merges = 1;
169         parent = xmalloc(ents * sizeof(*parent));
170         /* Again, the revs are all reverse */
171         for (i = 0; i < ents; i++)
172                 hashcpy((unsigned char *)(parent + i),
173                         ent[ents - 1 - i].item->sha1);
174         diff_tree_combined(parent[0], parent + 1, ents - 1,
175                            revs->dense_combined_merges, revs);
176         return 0;
177 }
178
179 static void refresh_index_quietly(void)
180 {
181         struct lock_file *lock_file;
182         int fd;
183
184         lock_file = xcalloc(1, sizeof(struct lock_file));
185         fd = hold_locked_index(lock_file, 0);
186         if (fd < 0)
187                 return;
188         discard_cache();
189         read_cache();
190         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
191
192         if (active_cache_changed &&
193             !write_cache(fd, active_cache, active_nr))
194                 commit_locked_index(lock_file);
195
196         rollback_lock_file(lock_file);
197 }
198
199 int cmd_diff(int argc, const char **argv, const char *prefix)
200 {
201         int i;
202         struct rev_info rev;
203         struct object_array_entry ent[100];
204         int ents = 0, blobs = 0, paths = 0;
205         const char *path = NULL;
206         struct blobinfo blob[2];
207         int nongit = 0;
208         int result = 0;
209
210         /*
211          * We could get N tree-ish in the rev.pending_objects list.
212          * Also there could be M blobs there, and P pathspecs.
213          *
214          * N=0, M=0:
215          *      cache vs files (diff-files)
216          * N=0, M=2:
217          *      compare two random blobs.  P must be zero.
218          * N=0, M=1, P=1:
219          *      compare a blob with a working tree file.
220          *
221          * N=1, M=0:
222          *      tree vs cache (diff-index --cached)
223          *
224          * N=2, M=0:
225          *      tree vs tree (diff-tree)
226          *
227          * Other cases are errors.
228          */
229
230         prefix = setup_git_directory_gently(&nongit);
231         git_config(git_diff_ui_config);
232         init_revisions(&rev, prefix);
233         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
234
235         if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
236                 argc = 0;
237         else
238                 argc = setup_revisions(argc, argv, &rev, NULL);
239         if (!rev.diffopt.output_format) {
240                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
241                 if (diff_setup_done(&rev.diffopt) < 0)
242                         die("diff_setup_done failed");
243         }
244         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
245         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
246
247         /*
248          * If the user asked for our exit code then don't start a
249          * pager or we would end up reporting its exit code instead.
250          */
251         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
252                 setup_pager();
253
254         /* Do we have --cached and not have a pending object, then
255          * default to HEAD by hand.  Eek.
256          */
257         if (!rev.pending.nr) {
258                 int i;
259                 for (i = 1; i < argc; i++) {
260                         const char *arg = argv[i];
261                         if (!strcmp(arg, "--"))
262                                 break;
263                         else if (!strcmp(arg, "--cached")) {
264                                 add_head_to_pending(&rev);
265                                 if (!rev.pending.nr)
266                                         die("No HEAD commit to compare with (yet)");
267                                 break;
268                         }
269                 }
270         }
271
272         for (i = 0; i < rev.pending.nr; i++) {
273                 struct object_array_entry *list = rev.pending.objects+i;
274                 struct object *obj = list->item;
275                 const char *name = list->name;
276                 int flags = (obj->flags & UNINTERESTING);
277                 if (!obj->parsed)
278                         obj = parse_object(obj->sha1);
279                 obj = deref_tag(obj, NULL, 0);
280                 if (!obj)
281                         die("invalid object '%s' given.", name);
282                 if (obj->type == OBJ_COMMIT)
283                         obj = &((struct commit *)obj)->tree->object;
284                 if (obj->type == OBJ_TREE) {
285                         if (ARRAY_SIZE(ent) <= ents)
286                                 die("more than %d trees given: '%s'",
287                                     (int) ARRAY_SIZE(ent), name);
288                         obj->flags |= flags;
289                         ent[ents].item = obj;
290                         ent[ents].name = name;
291                         ents++;
292                         continue;
293                 }
294                 if (obj->type == OBJ_BLOB) {
295                         if (2 <= blobs)
296                                 die("more than two blobs given: '%s'", name);
297                         hashcpy(blob[blobs].sha1, obj->sha1);
298                         blob[blobs].name = name;
299                         blob[blobs].mode = list->mode;
300                         blobs++;
301                         continue;
302
303                 }
304                 die("unhandled object '%s' given.", name);
305         }
306         if (rev.prune_data) {
307                 const char **pathspec = rev.prune_data;
308                 while (*pathspec) {
309                         if (!path)
310                                 path = *pathspec;
311                         paths++;
312                         pathspec++;
313                 }
314         }
315
316         /*
317          * Now, do the arguments look reasonable?
318          */
319         if (!ents) {
320                 switch (blobs) {
321                 case 0:
322                         result = run_diff_files_cmd(&rev, argc, argv);
323                         break;
324                 case 1:
325                         if (paths != 1)
326                                 usage(builtin_diff_usage);
327                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
328                         break;
329                 case 2:
330                         if (paths)
331                                 usage(builtin_diff_usage);
332                         result = builtin_diff_blobs(&rev, argc, argv, blob);
333                         break;
334                 default:
335                         usage(builtin_diff_usage);
336                 }
337         }
338         else if (blobs)
339                 usage(builtin_diff_usage);
340         else if (ents == 1)
341                 result = builtin_diff_index(&rev, argc, argv);
342         else if (ents == 2)
343                 result = builtin_diff_tree(&rev, argc, argv, ent);
344         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
345                 /* diff A...B where there is one sane merge base between
346                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
347                  * and ent[2] == B.  Show diff between the base and B.
348                  */
349                 ent[1] = ent[2];
350                 result = builtin_diff_tree(&rev, argc, argv, ent);
351         }
352         else
353                 result = builtin_diff_combined(&rev, argc, argv,
354                                              ent, ents);
355         result = diff_result_code(&rev.diffopt, result);
356         if (1 < rev.diffopt.skip_stat_unmatch)
357                 refresh_index_quietly();
358         return result;
359 }