Documentation: git-ls-tree (typofix)
[git.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 "diff <options> <rev>{0,2} -- <path>*";
27
28 static int builtin_diff_files(struct rev_info *revs,
29                               int argc, const char **argv)
30 {
31         int silent = 0;
32         while (1 < argc) {
33                 const char *arg = argv[1];
34                 if (!strcmp(arg, "--base"))
35                         revs->max_count = 1;
36                 else if (!strcmp(arg, "--ours"))
37                         revs->max_count = 2;
38                 else if (!strcmp(arg, "--theirs"))
39                         revs->max_count = 3;
40                 else if (!strcmp(arg, "-q"))
41                         silent = 1;
42                 else if (!strcmp(arg, "--raw"))
43                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
44                 else
45                         usage(builtin_diff_usage);
46                 argv++; argc--;
47         }
48         /*
49          * Make sure there are NO revision (i.e. pending object) parameter,
50          * specified rev.max_count is reasonable (0 <= n <= 3), and
51          * there is no other revision filtering parameter.
52          */
53         if (revs->pending_objects ||
54             revs->min_age != -1 ||
55             revs->max_age != -1 ||
56             3 < revs->max_count)
57                 usage(builtin_diff_usage);
58         if (revs->max_count < 0 &&
59             (revs->diffopt.output_format == DIFF_FORMAT_PATCH))
60                 revs->combine_merges = revs->dense_combined_merges = 1;
61         /*
62          * Backward compatibility wart - "diff-files -s" used to
63          * defeat the common diff option "-s" which asked for
64          * DIFF_FORMAT_NO_OUTPUT.
65          */
66         if (revs->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT)
67                 revs->diffopt.output_format = DIFF_FORMAT_RAW;
68         return run_diff_files(revs, silent);
69 }
70
71 static void stuff_change(struct diff_options *opt,
72                          unsigned old_mode, unsigned new_mode,
73                          const unsigned char *old_sha1,
74                          const unsigned char *new_sha1,
75                          const char *old_name,
76                          const char *new_name)
77 {
78         struct diff_filespec *one, *two;
79
80         if (memcmp(null_sha1, old_sha1, 20) &&
81             memcmp(null_sha1, new_sha1, 20) &&
82             !memcmp(old_sha1, new_sha1, 20))
83                 return;
84
85         if (opt->reverse_diff) {
86                 unsigned tmp;
87                 const unsigned char *tmp_u;
88                 const char *tmp_c;
89                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
90                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
91                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
92         }
93         one = alloc_filespec(old_name);
94         two = alloc_filespec(new_name);
95         fill_filespec(one, old_sha1, old_mode);
96         fill_filespec(two, new_sha1, new_mode);
97
98         /* NEEDSWORK: shouldn't this part of diffopt??? */
99         diff_queue(&diff_queued_diff, one, two);
100 }
101
102 static int builtin_diff_b_f(struct rev_info *revs,
103                             int argc, const char **argv,
104                             struct blobinfo *blob,
105                             const char *path)
106 {
107         /* Blob vs file in the working tree*/
108         struct stat st;
109
110         while (1 < argc) {
111                 const char *arg = argv[1];
112                 if (!strcmp(arg, "--raw"))
113                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
114                 else
115                         usage(builtin_diff_usage);
116                 argv++; argc--;
117         }
118         if (lstat(path, &st))
119                 die("'%s': %s", path, strerror(errno));
120         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
121                 die("'%s': not a regular file or symlink", path);
122         stuff_change(&revs->diffopt,
123                      canon_mode(st.st_mode), canon_mode(st.st_mode),
124                      blob[0].sha1, null_sha1,
125                      path, path);
126         diffcore_std(&revs->diffopt);
127         diff_flush(&revs->diffopt);
128         return 0;
129 }
130
131 static int builtin_diff_blobs(struct rev_info *revs,
132                               int argc, const char **argv,
133                               struct blobinfo *blob)
134 {
135         /* Blobs: the arguments are reversed when setup_revisions()
136          * picked them up.
137          */
138         unsigned mode = canon_mode(S_IFREG | 0644);
139
140         while (1 < argc) {
141                 const char *arg = argv[1];
142                 if (!strcmp(arg, "--raw"))
143                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
144                 else
145                         usage(builtin_diff_usage);
146                 argv++; argc--;
147         }
148         stuff_change(&revs->diffopt,
149                      mode, mode,
150                      blob[1].sha1, blob[0].sha1,
151                      blob[0].name, blob[0].name);
152         diffcore_std(&revs->diffopt);
153         diff_flush(&revs->diffopt);
154         return 0;
155 }
156
157 static int builtin_diff_index(struct rev_info *revs,
158                               int argc, const char **argv)
159 {
160         int cached = 0;
161         while (1 < argc) {
162                 const char *arg = argv[1];
163                 if (!strcmp(arg, "--cached"))
164                         cached = 1;
165                 else if (!strcmp(arg, "--raw"))
166                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
167                 else
168                         usage(builtin_diff_usage);
169                 argv++; argc--;
170         }
171         /*
172          * Make sure there is one revision (i.e. pending object),
173          * and there is no revision filtering parameters.
174          */
175         if (!revs->pending_objects || revs->pending_objects->next ||
176             revs->max_count != -1 || revs->min_age != -1 ||
177             revs->max_age != -1)
178                 usage(builtin_diff_usage);
179         return run_diff_index(revs, cached);
180 }
181
182 static int builtin_diff_tree(struct rev_info *revs,
183                              int argc, const char **argv,
184                              struct object_list *ent)
185 {
186         const unsigned char *(sha1[2]);
187         int swap = 1;
188         while (1 < argc) {
189                 const char *arg = argv[1];
190                 if (!strcmp(arg, "--raw"))
191                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
192                 else
193                         usage(builtin_diff_usage);
194                 argv++; argc--;
195         }
196
197         /* We saw two trees, ent[0] and ent[1].
198          * unless ent[0] is unintesting, they are swapped
199          */
200         if (ent[0].item->flags & UNINTERESTING)
201                 swap = 0;
202         sha1[swap] = ent[0].item->sha1;
203         sha1[1-swap] = ent[1].item->sha1;
204         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
205         log_tree_diff_flush(revs);
206         return 0;
207 }
208
209 static int builtin_diff_combined(struct rev_info *revs,
210                                  int argc, const char **argv,
211                                  struct object_list *ent,
212                                  int ents)
213 {
214         const unsigned char (*parent)[20];
215         int i;
216
217         while (1 < argc) {
218                 const char *arg = argv[1];
219                 if (!strcmp(arg, "--raw"))
220                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
221                 else
222                         usage(builtin_diff_usage);
223                 argv++; argc--;
224         }
225         if (!revs->dense_combined_merges && !revs->combine_merges)
226                 revs->dense_combined_merges = revs->combine_merges = 1;
227         parent = xmalloc(ents * sizeof(*parent));
228         /* Again, the revs are all reverse */
229         for (i = 0; i < ents; i++)
230                 memcpy(parent + i, ent[ents - 1 - i].item->sha1, 20);
231         diff_tree_combined(parent[0], parent + 1, ents - 1,
232                            revs->dense_combined_merges, revs);
233         return 0;
234 }
235
236 void add_head(struct rev_info *revs)
237 {
238         unsigned char sha1[20];
239         struct object *obj;
240         if (get_sha1("HEAD", sha1))
241                 return;
242         obj = parse_object(sha1);
243         if (!obj)
244                 return;
245         add_object(obj, &revs->pending_objects, NULL, "HEAD");
246 }
247
248 int cmd_diff(int argc, const char **argv, char **envp)
249 {
250         struct rev_info rev;
251         struct object_list *list, ent[100];
252         int ents = 0, blobs = 0, paths = 0;
253         const char *path = NULL;
254         struct blobinfo blob[2];
255
256         /*
257          * We could get N tree-ish in the rev.pending_objects list.
258          * Also there could be M blobs there, and P pathspecs.
259          *
260          * N=0, M=0:
261          *      cache vs files (diff-files)
262          * N=0, M=2:
263          *      compare two random blobs.  P must be zero.
264          * N=0, M=1, P=1:
265          *      compare a blob with a working tree file.
266          *
267          * N=1, M=0:
268          *      tree vs cache (diff-index --cached)
269          *
270          * N=2, M=0:
271          *      tree vs tree (diff-tree)
272          *
273          * Other cases are errors.
274          */
275
276         git_config(git_diff_config);
277         init_revisions(&rev);
278         rev.diffopt.output_format = DIFF_FORMAT_PATCH;
279
280         argc = setup_revisions(argc, argv, &rev, NULL);
281         /* Do we have --cached and not have a pending object, then
282          * default to HEAD by hand.  Eek.
283          */
284         if (!rev.pending_objects) {
285                 int i;
286                 for (i = 1; i < argc; i++) {
287                         const char *arg = argv[i];
288                         if (!strcmp(arg, "--"))
289                                 break;
290                         else if (!strcmp(arg, "--cached")) {
291                                 add_head(&rev);
292                                 break;
293                         }
294                 }
295         }
296
297         for (list = rev.pending_objects; list; list = list->next) {
298                 struct object *obj = list->item;
299                 const char *name = list->name;
300                 int flags = (obj->flags & UNINTERESTING);
301                 if (!obj->parsed)
302                         obj = parse_object(obj->sha1);
303                 obj = deref_tag(obj, NULL, 0);
304                 if (!obj)
305                         die("invalid object '%s' given.", name);
306                 if (!strcmp(obj->type, commit_type))
307                         obj = &((struct commit *)obj)->tree->object;
308                 if (!strcmp(obj->type, tree_type)) {
309                         if (ARRAY_SIZE(ent) <= ents)
310                                 die("more than %d trees given: '%s'",
311                                     (int) ARRAY_SIZE(ent), name);
312                         obj->flags |= flags;
313                         ent[ents].item = obj;
314                         ent[ents].name = name;
315                         ents++;
316                         continue;
317                 }
318                 if (!strcmp(obj->type, blob_type)) {
319                         if (2 <= blobs)
320                                 die("more than two blobs given: '%s'", name);
321                         memcpy(blob[blobs].sha1, obj->sha1, 20);
322                         blob[blobs].name = name;
323                         blobs++;
324                         continue;
325
326                 }
327                 die("unhandled object '%s' given.", name);
328         }
329         if (rev.prune_data) {
330                 const char **pathspec = rev.prune_data;
331                 while (*pathspec) {
332                         if (!path)
333                                 path = *pathspec;
334                         paths++;
335                         pathspec++;
336                 }
337         }
338
339         /*
340          * Now, do the arguments look reasonable?
341          */
342         if (!ents) {
343                 switch (blobs) {
344                 case 0:
345                         return builtin_diff_files(&rev, argc, argv);
346                         break;
347                 case 1:
348                         if (paths != 1)
349                                 usage(builtin_diff_usage);
350                         return builtin_diff_b_f(&rev, argc, argv, blob, path);
351                         break;
352                 case 2:
353                         if (paths)
354                                 usage(builtin_diff_usage);
355                         return builtin_diff_blobs(&rev, argc, argv, blob);
356                         break;
357                 default:
358                         usage(builtin_diff_usage);
359                 }
360         }
361         else if (blobs)
362                 usage(builtin_diff_usage);
363         else if (ents == 1)
364                 return builtin_diff_index(&rev, argc, argv);
365         else if (ents == 2)
366                 return builtin_diff_tree(&rev, argc, argv, ent);
367         else
368                 return builtin_diff_combined(&rev, argc, argv, ent, ents);
369         usage(builtin_diff_usage);
370 }