Merge branch 'master' of git://repo.or.cz/git-gui
[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 /* NEEDSWORK: struct object has place for name but we _do_
17  * know mode when we extracted the blob out of a tree, which
18  * we currently lose.
19  */
20 struct blobinfo {
21         unsigned char sha1[20];
22         const char *name;
23 };
24
25 static const char builtin_diff_usage[] =
26 "git-diff <options> <rev>{0,2} -- <path>*";
27
28 static void stuff_change(struct diff_options *opt,
29                          unsigned old_mode, unsigned new_mode,
30                          const unsigned char *old_sha1,
31                          const unsigned char *new_sha1,
32                          const char *old_name,
33                          const char *new_name)
34 {
35         struct diff_filespec *one, *two;
36
37         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
38             !hashcmp(old_sha1, new_sha1))
39                 return;
40
41         if (opt->reverse_diff) {
42                 unsigned tmp;
43                 const unsigned char *tmp_u;
44                 const char *tmp_c;
45                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
46                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
47                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
48         }
49         one = alloc_filespec(old_name);
50         two = alloc_filespec(new_name);
51         fill_filespec(one, old_sha1, old_mode);
52         fill_filespec(two, new_sha1, new_mode);
53
54         /* NEEDSWORK: shouldn't this part of diffopt??? */
55         diff_queue(&diff_queued_diff, one, two);
56 }
57
58 static int builtin_diff_b_f(struct rev_info *revs,
59                             int argc, const char **argv,
60                             struct blobinfo *blob,
61                             const char *path)
62 {
63         /* Blob vs file in the working tree*/
64         struct stat st;
65
66         if (argc > 1)
67                 usage(builtin_diff_usage);
68
69         if (lstat(path, &st))
70                 die("'%s': %s", path, strerror(errno));
71         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
72                 die("'%s': not a regular file or symlink", path);
73         stuff_change(&revs->diffopt,
74                      canon_mode(st.st_mode), canon_mode(st.st_mode),
75                      blob[0].sha1, null_sha1,
76                      path, path);
77         diffcore_std(&revs->diffopt);
78         diff_flush(&revs->diffopt);
79         return 0;
80 }
81
82 static int builtin_diff_blobs(struct rev_info *revs,
83                               int argc, const char **argv,
84                               struct blobinfo *blob)
85 {
86         unsigned mode = canon_mode(S_IFREG | 0644);
87
88         if (argc > 1)
89                 usage(builtin_diff_usage);
90
91         stuff_change(&revs->diffopt,
92                      mode, mode,
93                      blob[0].sha1, blob[1].sha1,
94                      blob[0].name, blob[1].name);
95         diffcore_std(&revs->diffopt);
96         diff_flush(&revs->diffopt);
97         return 0;
98 }
99
100 static int builtin_diff_index(struct rev_info *revs,
101                               int argc, const char **argv)
102 {
103         int cached = 0;
104         while (1 < argc) {
105                 const char *arg = argv[1];
106                 if (!strcmp(arg, "--cached"))
107                         cached = 1;
108                 else
109                         usage(builtin_diff_usage);
110                 argv++; argc--;
111         }
112         /*
113          * Make sure there is one revision (i.e. pending object),
114          * and there is no revision filtering parameters.
115          */
116         if (revs->pending.nr != 1 ||
117             revs->max_count != -1 || revs->min_age != -1 ||
118             revs->max_age != -1)
119                 usage(builtin_diff_usage);
120         if (read_cache() < 0) {
121                 perror("read_cache");
122                 return -1;
123         }
124         return run_diff_index(revs, cached);
125 }
126
127 static int builtin_diff_tree(struct rev_info *revs,
128                              int argc, const char **argv,
129                              struct object_array_entry *ent)
130 {
131         const unsigned char *(sha1[2]);
132         int swap = 0;
133
134         if (argc > 1)
135                 usage(builtin_diff_usage);
136
137         /* We saw two trees, ent[0] and ent[1].
138          * if ent[1] is uninteresting, they are swapped
139          */
140         if (ent[1].item->flags & UNINTERESTING)
141                 swap = 1;
142         sha1[swap] = ent[0].item->sha1;
143         sha1[1-swap] = ent[1].item->sha1;
144         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
145         log_tree_diff_flush(revs);
146         return 0;
147 }
148
149 static int builtin_diff_combined(struct rev_info *revs,
150                                  int argc, const char **argv,
151                                  struct object_array_entry *ent,
152                                  int ents)
153 {
154         const unsigned char (*parent)[20];
155         int i;
156
157         if (argc > 1)
158                 usage(builtin_diff_usage);
159
160         if (!revs->dense_combined_merges && !revs->combine_merges)
161                 revs->dense_combined_merges = revs->combine_merges = 1;
162         parent = xmalloc(ents * sizeof(*parent));
163         /* Again, the revs are all reverse */
164         for (i = 0; i < ents; i++)
165                 hashcpy((unsigned char *)(parent + i),
166                         ent[ents - 1 - i].item->sha1);
167         diff_tree_combined(parent[0], parent + 1, ents - 1,
168                            revs->dense_combined_merges, revs);
169         return 0;
170 }
171
172 void add_head(struct rev_info *revs)
173 {
174         unsigned char sha1[20];
175         struct object *obj;
176         if (get_sha1("HEAD", sha1))
177                 return;
178         obj = parse_object(sha1);
179         if (!obj)
180                 return;
181         add_pending_object(revs, obj, "HEAD");
182 }
183
184 int cmd_diff(int argc, const char **argv, const char *prefix)
185 {
186         int i;
187         struct rev_info rev;
188         struct object_array_entry ent[100];
189         int ents = 0, blobs = 0, paths = 0;
190         const char *path = NULL;
191         struct blobinfo blob[2];
192         int nongit = 0;
193
194         /*
195          * We could get N tree-ish in the rev.pending_objects list.
196          * Also there could be M blobs there, and P pathspecs.
197          *
198          * N=0, M=0:
199          *      cache vs files (diff-files)
200          * N=0, M=2:
201          *      compare two random blobs.  P must be zero.
202          * N=0, M=1, P=1:
203          *      compare a blob with a working tree file.
204          *
205          * N=1, M=0:
206          *      tree vs cache (diff-index --cached)
207          *
208          * N=2, M=0:
209          *      tree vs tree (diff-tree)
210          *
211          * Other cases are errors.
212          */
213
214         prefix = setup_git_directory_gently(&nongit);
215         git_config(git_diff_ui_config);
216         init_revisions(&rev, prefix);
217
218         if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
219                 argc = 0;
220         else
221                 argc = setup_revisions(argc, argv, &rev, NULL);
222         if (!rev.diffopt.output_format) {
223                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
224                 if (diff_setup_done(&rev.diffopt) < 0)
225                         die("diff_setup_done failed");
226         }
227
228         /* Do we have --cached and not have a pending object, then
229          * default to HEAD by hand.  Eek.
230          */
231         if (!rev.pending.nr) {
232                 int i;
233                 for (i = 1; i < argc; i++) {
234                         const char *arg = argv[i];
235                         if (!strcmp(arg, "--"))
236                                 break;
237                         else if (!strcmp(arg, "--cached")) {
238                                 add_head(&rev);
239                                 if (!rev.pending.nr)
240                                         die("No HEAD commit to compare with (yet)");
241                                 break;
242                         }
243                 }
244         }
245
246         for (i = 0; i < rev.pending.nr; i++) {
247                 struct object_array_entry *list = rev.pending.objects+i;
248                 struct object *obj = list->item;
249                 const char *name = list->name;
250                 int flags = (obj->flags & UNINTERESTING);
251                 if (!obj->parsed)
252                         obj = parse_object(obj->sha1);
253                 obj = deref_tag(obj, NULL, 0);
254                 if (!obj)
255                         die("invalid object '%s' given.", name);
256                 if (obj->type == OBJ_COMMIT)
257                         obj = &((struct commit *)obj)->tree->object;
258                 if (obj->type == OBJ_TREE) {
259                         if (ARRAY_SIZE(ent) <= ents)
260                                 die("more than %d trees given: '%s'",
261                                     (int) ARRAY_SIZE(ent), name);
262                         obj->flags |= flags;
263                         ent[ents].item = obj;
264                         ent[ents].name = name;
265                         ents++;
266                         continue;
267                 }
268                 if (obj->type == OBJ_BLOB) {
269                         if (2 <= blobs)
270                                 die("more than two blobs given: '%s'", name);
271                         hashcpy(blob[blobs].sha1, obj->sha1);
272                         blob[blobs].name = name;
273                         blobs++;
274                         continue;
275
276                 }
277                 die("unhandled object '%s' given.", name);
278         }
279         if (rev.prune_data) {
280                 const char **pathspec = rev.prune_data;
281                 while (*pathspec) {
282                         if (!path)
283                                 path = *pathspec;
284                         paths++;
285                         pathspec++;
286                 }
287         }
288
289         /*
290          * Now, do the arguments look reasonable?
291          */
292         if (!ents) {
293                 switch (blobs) {
294                 case 0:
295                         return run_diff_files_cmd(&rev, argc, argv);
296                         break;
297                 case 1:
298                         if (paths != 1)
299                                 usage(builtin_diff_usage);
300                         return builtin_diff_b_f(&rev, argc, argv, blob, path);
301                         break;
302                 case 2:
303                         if (paths)
304                                 usage(builtin_diff_usage);
305                         return builtin_diff_blobs(&rev, argc, argv, blob);
306                         break;
307                 default:
308                         usage(builtin_diff_usage);
309                 }
310         }
311         else if (blobs)
312                 usage(builtin_diff_usage);
313         else if (ents == 1)
314                 return builtin_diff_index(&rev, argc, argv);
315         else if (ents == 2)
316                 return builtin_diff_tree(&rev, argc, argv, ent);
317         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
318                 /* diff A...B where there is one sane merge base between
319                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
320                  * and ent[2] == B.  Show diff between the base and B.
321                  */
322                 ent[1] = ent[2];
323                 return builtin_diff_tree(&rev, argc, argv, ent);
324         }
325         else
326                 return builtin_diff_combined(&rev, argc, argv,
327                                              ent, ents);
328         usage(builtin_diff_usage);
329 }