Merge branch 'jk/git-connection-deadlock-fix' into maint-1.7.4
[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.paths) < 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         int result;
206         unsigned int options = 0;
207
208         while (1 < argc && argv[1][0] == '-') {
209                 if (!strcmp(argv[1], "--base"))
210                         revs->max_count = 1;
211                 else if (!strcmp(argv[1], "--ours"))
212                         revs->max_count = 2;
213                 else if (!strcmp(argv[1], "--theirs"))
214                         revs->max_count = 3;
215                 else if (!strcmp(argv[1], "-q"))
216                         options |= DIFF_SILENT_ON_REMOVED;
217                 else if (!strcmp(argv[1], "-h"))
218                         usage(builtin_diff_usage);
219                 else
220                         return error("invalid option: %s", argv[1]);
221                 argv++; argc--;
222         }
223
224         /*
225          * "diff --base" should not combine merges because it was not
226          * asked to.  "diff -c" should not densify (if the user wants
227          * dense one, --cc can be explicitly asked for, or just rely
228          * on the default).
229          */
230         if (revs->max_count == -1 && !revs->combine_merges &&
231             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
232                 revs->combine_merges = revs->dense_combined_merges = 1;
233
234         setup_work_tree();
235         if (read_cache_preload(revs->diffopt.paths) < 0) {
236                 perror("read_cache_preload");
237                 return -1;
238         }
239         result = run_diff_files(revs, options);
240         return diff_result_code(&revs->diffopt, result);
241 }
242
243 int cmd_diff(int argc, const char **argv, const char *prefix)
244 {
245         int i;
246         struct rev_info rev;
247         struct object_array_entry ent[100];
248         int ents = 0, blobs = 0, paths = 0;
249         const char *path = NULL;
250         struct blobinfo blob[2];
251         int nongit;
252         int result = 0;
253
254         /*
255          * We could get N tree-ish in the rev.pending_objects list.
256          * Also there could be M blobs there, and P pathspecs.
257          *
258          * N=0, M=0:
259          *      cache vs files (diff-files)
260          * N=0, M=2:
261          *      compare two random blobs.  P must be zero.
262          * N=0, M=1, P=1:
263          *      compare a blob with a working tree file.
264          *
265          * N=1, M=0:
266          *      tree vs cache (diff-index --cached)
267          *
268          * N=2, M=0:
269          *      tree vs tree (diff-tree)
270          *
271          * N=0, M=0, P=2:
272          *      compare two filesystem entities (aka --no-index).
273          *
274          * Other cases are errors.
275          */
276
277         prefix = setup_git_directory_gently(&nongit);
278         gitmodules_config();
279         git_config(git_diff_ui_config, NULL);
280
281         if (diff_use_color_default == -1)
282                 diff_use_color_default = git_use_color_default;
283
284         init_revisions(&rev, prefix);
285
286         /* If this is a no-index diff, just run it and exit there. */
287         diff_no_index(&rev, argc, argv, nongit, prefix);
288
289         /* Otherwise, we are doing the usual "git" diff */
290         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
291
292         /* Default to let external and textconv be used */
293         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
294         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
295
296         if (nongit)
297                 die("Not a git repository");
298         argc = setup_revisions(argc, argv, &rev, NULL);
299         if (!rev.diffopt.output_format) {
300                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
301                 if (diff_setup_done(&rev.diffopt) < 0)
302                         die("diff_setup_done failed");
303         }
304
305         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
306
307         /*
308          * If the user asked for our exit code then don't start a
309          * pager or we would end up reporting its exit code instead.
310          */
311         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
312             check_pager_config("diff") != 0)
313                 setup_pager();
314
315         /*
316          * Do we have --cached and not have a pending object, then
317          * default to HEAD by hand.  Eek.
318          */
319         if (!rev.pending.nr) {
320                 int i;
321                 for (i = 1; i < argc; i++) {
322                         const char *arg = argv[i];
323                         if (!strcmp(arg, "--"))
324                                 break;
325                         else if (!strcmp(arg, "--cached") ||
326                                  !strcmp(arg, "--staged")) {
327                                 add_head_to_pending(&rev);
328                                 if (!rev.pending.nr) {
329                                         struct tree *tree;
330                                         tree = lookup_tree((const unsigned char*)EMPTY_TREE_SHA1_BIN);
331                                         add_pending_object(&rev, &tree->object, "HEAD");
332                                 }
333                                 break;
334                         }
335                 }
336         }
337
338         for (i = 0; i < rev.pending.nr; i++) {
339                 struct object_array_entry *list = rev.pending.objects+i;
340                 struct object *obj = list->item;
341                 const char *name = list->name;
342                 int flags = (obj->flags & UNINTERESTING);
343                 if (!obj->parsed)
344                         obj = parse_object(obj->sha1);
345                 obj = deref_tag(obj, NULL, 0);
346                 if (!obj)
347                         die("invalid object '%s' given.", name);
348                 if (obj->type == OBJ_COMMIT)
349                         obj = &((struct commit *)obj)->tree->object;
350                 if (obj->type == OBJ_TREE) {
351                         if (ARRAY_SIZE(ent) <= ents)
352                                 die("more than %d trees given: '%s'",
353                                     (int) ARRAY_SIZE(ent), name);
354                         obj->flags |= flags;
355                         ent[ents].item = obj;
356                         ent[ents].name = name;
357                         ents++;
358                         continue;
359                 }
360                 if (obj->type == OBJ_BLOB) {
361                         if (2 <= blobs)
362                                 die("more than two blobs given: '%s'", name);
363                         hashcpy(blob[blobs].sha1, obj->sha1);
364                         blob[blobs].name = name;
365                         blob[blobs].mode = list->mode;
366                         blobs++;
367                         continue;
368
369                 }
370                 die("unhandled object '%s' given.", name);
371         }
372         if (rev.prune_data) {
373                 const char **pathspec = rev.prune_data;
374                 while (*pathspec) {
375                         if (!path)
376                                 path = *pathspec;
377                         paths++;
378                         pathspec++;
379                 }
380         }
381
382         /*
383          * Now, do the arguments look reasonable?
384          */
385         if (!ents) {
386                 switch (blobs) {
387                 case 0:
388                         result = builtin_diff_files(&rev, argc, argv);
389                         break;
390                 case 1:
391                         if (paths != 1)
392                                 usage(builtin_diff_usage);
393                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
394                         break;
395                 case 2:
396                         if (paths)
397                                 usage(builtin_diff_usage);
398                         result = builtin_diff_blobs(&rev, argc, argv, blob);
399                         break;
400                 default:
401                         usage(builtin_diff_usage);
402                 }
403         }
404         else if (blobs)
405                 usage(builtin_diff_usage);
406         else if (ents == 1)
407                 result = builtin_diff_index(&rev, argc, argv);
408         else if (ents == 2)
409                 result = builtin_diff_tree(&rev, argc, argv, ent);
410         else if (ent[0].item->flags & UNINTERESTING) {
411                 /*
412                  * diff A...B where there is at least one merge base
413                  * between A and B.  We have ent[0] == merge-base,
414                  * ent[ents-2] == A, and ent[ents-1] == B.  Show diff
415                  * between the base and B.  Note that we pick one
416                  * merge base at random if there are more than one.
417                  */
418                 ent[1] = ent[ents-1];
419                 result = builtin_diff_tree(&rev, argc, argv, ent);
420         } else
421                 result = builtin_diff_combined(&rev, argc, argv,
422                                                ent, ents);
423         result = diff_result_code(&rev.diffopt, result);
424         if (1 < rev.diffopt.skip_stat_unmatch)
425                 refresh_index_quietly();
426         return result;
427 }