Merge branch 'jn/userdiff-perl-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 "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
18 struct blobinfo {
19         unsigned char sha1[20];
20         const char *name;
21         unsigned mode;
22 };
23
24 static const char builtin_diff_usage[] =
25 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
26
27 static void stuff_change(struct diff_options *opt,
28                          unsigned old_mode, unsigned new_mode,
29                          const unsigned char *old_sha1,
30                          const unsigned char *new_sha1,
31                          const char *old_name,
32                          const char *new_name)
33 {
34         struct diff_filespec *one, *two;
35
36         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
37             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
38                 return;
39
40         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
41                 unsigned tmp;
42                 const unsigned char *tmp_u;
43                 const char *tmp_c;
44                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
45                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
46                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
47         }
48
49         if (opt->prefix &&
50             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
51              strncmp(new_name, opt->prefix, opt->prefix_length)))
52                 return;
53
54         one = alloc_filespec(old_name);
55         two = alloc_filespec(new_name);
56         fill_filespec(one, old_sha1, old_mode);
57         fill_filespec(two, new_sha1, new_mode);
58
59         diff_queue(&diff_queued_diff, one, two);
60 }
61
62 static int builtin_diff_b_f(struct rev_info *revs,
63                             int argc, const char **argv,
64                             struct blobinfo *blob,
65                             const char *path)
66 {
67         /* Blob vs file in the working tree*/
68         struct stat st;
69
70         if (argc > 1)
71                 usage(builtin_diff_usage);
72
73         if (lstat(path, &st))
74                 die_errno(_("failed to stat '%s'"), path);
75         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
76                 die(_("'%s': not a regular file or symlink"), path);
77
78         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
79
80         if (blob[0].mode == S_IFINVALID)
81                 blob[0].mode = canon_mode(st.st_mode);
82
83         stuff_change(&revs->diffopt,
84                      blob[0].mode, canon_mode(st.st_mode),
85                      blob[0].sha1, null_sha1,
86                      path, path);
87         diffcore_std(&revs->diffopt);
88         diff_flush(&revs->diffopt);
89         return 0;
90 }
91
92 static int builtin_diff_blobs(struct rev_info *revs,
93                               int argc, const char **argv,
94                               struct blobinfo *blob)
95 {
96         unsigned mode = canon_mode(S_IFREG | 0644);
97
98         if (argc > 1)
99                 usage(builtin_diff_usage);
100
101         if (blob[0].mode == S_IFINVALID)
102                 blob[0].mode = mode;
103
104         if (blob[1].mode == S_IFINVALID)
105                 blob[1].mode = mode;
106
107         stuff_change(&revs->diffopt,
108                      blob[0].mode, blob[1].mode,
109                      blob[0].sha1, blob[1].sha1,
110                      blob[0].name, blob[1].name);
111         diffcore_std(&revs->diffopt);
112         diff_flush(&revs->diffopt);
113         return 0;
114 }
115
116 static int builtin_diff_index(struct rev_info *revs,
117                               int argc, const char **argv)
118 {
119         int cached = 0;
120         while (1 < argc) {
121                 const char *arg = argv[1];
122                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
123                         cached = 1;
124                 else
125                         usage(builtin_diff_usage);
126                 argv++; argc--;
127         }
128         if (!cached)
129                 setup_work_tree();
130         /*
131          * Make sure there is one revision (i.e. pending object),
132          * and there is no revision filtering parameters.
133          */
134         if (revs->pending.nr != 1 ||
135             revs->max_count != -1 || revs->min_age != -1 ||
136             revs->max_age != -1)
137                 usage(builtin_diff_usage);
138         if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
139                 perror("read_cache_preload");
140                 return -1;
141         }
142         return run_diff_index(revs, cached);
143 }
144
145 static int builtin_diff_tree(struct rev_info *revs,
146                              int argc, const char **argv,
147                              struct object_array_entry *ent)
148 {
149         const unsigned char *(sha1[2]);
150         int swap = 0;
151
152         if (argc > 1)
153                 usage(builtin_diff_usage);
154
155         /* We saw two trees, ent[0] and ent[1].
156          * if ent[1] is uninteresting, they are swapped
157          */
158         if (ent[1].item->flags & UNINTERESTING)
159                 swap = 1;
160         sha1[swap] = ent[0].item->sha1;
161         sha1[1-swap] = ent[1].item->sha1;
162         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
163         log_tree_diff_flush(revs);
164         return 0;
165 }
166
167 static int builtin_diff_combined(struct rev_info *revs,
168                                  int argc, const char **argv,
169                                  struct object_array_entry *ent,
170                                  int ents)
171 {
172         const unsigned char (*parent)[20];
173         int i;
174
175         if (argc > 1)
176                 usage(builtin_diff_usage);
177
178         if (!revs->dense_combined_merges && !revs->combine_merges)
179                 revs->dense_combined_merges = revs->combine_merges = 1;
180         parent = xmalloc(ents * sizeof(*parent));
181         for (i = 0; i < ents; i++)
182                 hashcpy((unsigned char *)(parent + i), ent[i].item->sha1);
183         diff_tree_combined(parent[0], parent + 1, ents - 1,
184                            revs->dense_combined_merges, revs);
185         return 0;
186 }
187
188 static void refresh_index_quietly(void)
189 {
190         struct lock_file *lock_file;
191         int fd;
192
193         lock_file = xcalloc(1, sizeof(struct lock_file));
194         fd = hold_locked_index(lock_file, 0);
195         if (fd < 0)
196                 return;
197         discard_cache();
198         read_cache();
199         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
200         update_index_if_able(&the_index, lock_file);
201 }
202
203 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
204 {
205         unsigned int options = 0;
206
207         while (1 < argc && argv[1][0] == '-') {
208                 if (!strcmp(argv[1], "--base"))
209                         revs->max_count = 1;
210                 else if (!strcmp(argv[1], "--ours"))
211                         revs->max_count = 2;
212                 else if (!strcmp(argv[1], "--theirs"))
213                         revs->max_count = 3;
214                 else if (!strcmp(argv[1], "-q"))
215                         options |= DIFF_SILENT_ON_REMOVED;
216                 else if (!strcmp(argv[1], "-h"))
217                         usage(builtin_diff_usage);
218                 else
219                         return error(_("invalid option: %s"), argv[1]);
220                 argv++; argc--;
221         }
222
223         /*
224          * "diff --base" should not combine merges because it was not
225          * asked to.  "diff -c" should not densify (if the user wants
226          * dense one, --cc can be explicitly asked for, or just rely
227          * on the default).
228          */
229         if (revs->max_count == -1 && !revs->combine_merges &&
230             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
231                 revs->combine_merges = revs->dense_combined_merges = 1;
232
233         setup_work_tree();
234         if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
235                 perror("read_cache_preload");
236                 return -1;
237         }
238         return run_diff_files(revs, options);
239 }
240
241 int cmd_diff(int argc, const char **argv, const char *prefix)
242 {
243         int i;
244         struct rev_info rev;
245         struct object_array_entry ent[100];
246         int ents = 0, blobs = 0, paths = 0;
247         const char *path = NULL;
248         struct blobinfo blob[2];
249         int nongit;
250         int result = 0;
251
252         /*
253          * We could get N tree-ish in the rev.pending_objects list.
254          * Also there could be M blobs there, and P pathspecs.
255          *
256          * N=0, M=0:
257          *      cache vs files (diff-files)
258          * N=0, M=2:
259          *      compare two random blobs.  P must be zero.
260          * N=0, M=1, P=1:
261          *      compare a blob with a working tree file.
262          *
263          * N=1, M=0:
264          *      tree vs cache (diff-index --cached)
265          *
266          * N=2, M=0:
267          *      tree vs tree (diff-tree)
268          *
269          * N=0, M=0, P=2:
270          *      compare two filesystem entities (aka --no-index).
271          *
272          * Other cases are errors.
273          */
274
275         prefix = setup_git_directory_gently(&nongit);
276         gitmodules_config();
277         git_config(git_diff_ui_config, NULL);
278
279         if (diff_use_color_default == -1)
280                 diff_use_color_default = git_use_color_default;
281
282         init_revisions(&rev, prefix);
283
284         /* If this is a no-index diff, just run it and exit there. */
285         diff_no_index(&rev, argc, argv, nongit, prefix);
286
287         /* Otherwise, we are doing the usual "git" diff */
288         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
289
290         /* Default to let external and textconv be used */
291         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
292         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
293
294         if (nongit)
295                 die(_("Not a git repository"));
296         argc = setup_revisions(argc, argv, &rev, NULL);
297         if (!rev.diffopt.output_format) {
298                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
299                 if (diff_setup_done(&rev.diffopt) < 0)
300                         die(_("diff_setup_done failed"));
301         }
302
303         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
304
305         /*
306          * If the user asked for our exit code then don't start a
307          * pager or we would end up reporting its exit code instead.
308          */
309         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
310             check_pager_config("diff") != 0)
311                 setup_pager();
312
313         /*
314          * Do we have --cached and not have a pending object, then
315          * default to HEAD by hand.  Eek.
316          */
317         if (!rev.pending.nr) {
318                 int i;
319                 for (i = 1; i < argc; i++) {
320                         const char *arg = argv[i];
321                         if (!strcmp(arg, "--"))
322                                 break;
323                         else if (!strcmp(arg, "--cached") ||
324                                  !strcmp(arg, "--staged")) {
325                                 add_head_to_pending(&rev);
326                                 if (!rev.pending.nr) {
327                                         struct tree *tree;
328                                         tree = lookup_tree((const unsigned char*)EMPTY_TREE_SHA1_BIN);
329                                         add_pending_object(&rev, &tree->object, "HEAD");
330                                 }
331                                 break;
332                         }
333                 }
334         }
335
336         for (i = 0; i < rev.pending.nr; i++) {
337                 struct object_array_entry *list = rev.pending.objects+i;
338                 struct object *obj = list->item;
339                 const char *name = list->name;
340                 int flags = (obj->flags & UNINTERESTING);
341                 if (!obj->parsed)
342                         obj = parse_object(obj->sha1);
343                 obj = deref_tag(obj, NULL, 0);
344                 if (!obj)
345                         die(_("invalid object '%s' given."), name);
346                 if (obj->type == OBJ_COMMIT)
347                         obj = &((struct commit *)obj)->tree->object;
348                 if (obj->type == OBJ_TREE) {
349                         if (ARRAY_SIZE(ent) <= ents)
350                                 die(_("more than %d trees given: '%s'"),
351                                     (int) ARRAY_SIZE(ent), name);
352                         obj->flags |= flags;
353                         ent[ents].item = obj;
354                         ent[ents].name = name;
355                         ents++;
356                         continue;
357                 }
358                 if (obj->type == OBJ_BLOB) {
359                         if (2 <= blobs)
360                                 die(_("more than two blobs given: '%s'"), name);
361                         hashcpy(blob[blobs].sha1, obj->sha1);
362                         blob[blobs].name = name;
363                         blob[blobs].mode = list->mode;
364                         blobs++;
365                         continue;
366
367                 }
368                 die(_("unhandled object '%s' given."), name);
369         }
370         if (rev.prune_data.nr) {
371                 if (!path)
372                         path = rev.prune_data.items[0].match;
373                 paths += rev.prune_data.nr;
374         }
375
376         /*
377          * Now, do the arguments look reasonable?
378          */
379         if (!ents) {
380                 switch (blobs) {
381                 case 0:
382                         result = builtin_diff_files(&rev, argc, argv);
383                         break;
384                 case 1:
385                         if (paths != 1)
386                                 usage(builtin_diff_usage);
387                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
388                         break;
389                 case 2:
390                         if (paths)
391                                 usage(builtin_diff_usage);
392                         result = builtin_diff_blobs(&rev, argc, argv, blob);
393                         break;
394                 default:
395                         usage(builtin_diff_usage);
396                 }
397         }
398         else if (blobs)
399                 usage(builtin_diff_usage);
400         else if (ents == 1)
401                 result = builtin_diff_index(&rev, argc, argv);
402         else if (ents == 2)
403                 result = builtin_diff_tree(&rev, argc, argv, ent);
404         else if (ent[0].item->flags & UNINTERESTING) {
405                 /*
406                  * diff A...B where there is at least one merge base
407                  * between A and B.  We have ent[0] == merge-base,
408                  * ent[ents-2] == A, and ent[ents-1] == B.  Show diff
409                  * between the base and B.  Note that we pick one
410                  * merge base at random if there are more than one.
411                  */
412                 ent[1] = ent[ents-1];
413                 result = builtin_diff_tree(&rev, argc, argv, ent);
414         } else
415                 result = builtin_diff_combined(&rev, argc, argv,
416                                                ent, ents);
417         result = diff_result_code(&rev.diffopt, result);
418         if (1 < rev.diffopt.skip_stat_unmatch)
419                 refresh_index_quietly();
420         return result;
421 }