Merge branch 'js/gitweb-path-info-unquote'
[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 #include "sha1-array.h"
18
19 struct blobinfo {
20         unsigned char sha1[20];
21         const char *name;
22         unsigned mode;
23 };
24
25 static const char builtin_diff_usage[] =
26 "git diff [<options>] [<commit> [<commit>]] [--] [<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) && (old_mode == new_mode))
39                 return;
40
41         if (DIFF_OPT_TST(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
50         if (opt->prefix &&
51             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
52              strncmp(new_name, opt->prefix, opt->prefix_length)))
53                 return;
54
55         one = alloc_filespec(old_name);
56         two = alloc_filespec(new_name);
57         fill_filespec(one, old_sha1, old_mode);
58         fill_filespec(two, new_sha1, new_mode);
59
60         diff_queue(&diff_queued_diff, one, two);
61 }
62
63 static int builtin_diff_b_f(struct rev_info *revs,
64                             int argc, const char **argv,
65                             struct blobinfo *blob,
66                             const char *path)
67 {
68         /* Blob vs file in the working tree*/
69         struct stat st;
70
71         if (argc > 1)
72                 usage(builtin_diff_usage);
73
74         if (lstat(path, &st))
75                 die_errno(_("failed to stat '%s'"), path);
76         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
77                 die(_("'%s': not a regular file or symlink"), path);
78
79         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
80
81         if (blob[0].mode == S_IFINVALID)
82                 blob[0].mode = canon_mode(st.st_mode);
83
84         stuff_change(&revs->diffopt,
85                      blob[0].mode, canon_mode(st.st_mode),
86                      blob[0].sha1, null_sha1,
87                      path, path);
88         diffcore_std(&revs->diffopt);
89         diff_flush(&revs->diffopt);
90         return 0;
91 }
92
93 static int builtin_diff_blobs(struct rev_info *revs,
94                               int argc, const char **argv,
95                               struct blobinfo *blob)
96 {
97         unsigned mode = canon_mode(S_IFREG | 0644);
98
99         if (argc > 1)
100                 usage(builtin_diff_usage);
101
102         if (blob[0].mode == S_IFINVALID)
103                 blob[0].mode = mode;
104
105         if (blob[1].mode == S_IFINVALID)
106                 blob[1].mode = mode;
107
108         stuff_change(&revs->diffopt,
109                      blob[0].mode, blob[1].mode,
110                      blob[0].sha1, blob[1].sha1,
111                      blob[0].name, blob[1].name);
112         diffcore_std(&revs->diffopt);
113         diff_flush(&revs->diffopt);
114         return 0;
115 }
116
117 static int builtin_diff_index(struct rev_info *revs,
118                               int argc, const char **argv)
119 {
120         int cached = 0;
121         while (1 < argc) {
122                 const char *arg = argv[1];
123                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
124                         cached = 1;
125                 else
126                         usage(builtin_diff_usage);
127                 argv++; argc--;
128         }
129         if (!cached)
130                 setup_work_tree();
131         /*
132          * Make sure there is one revision (i.e. pending object),
133          * and there is no revision filtering parameters.
134          */
135         if (revs->pending.nr != 1 ||
136             revs->max_count != -1 || revs->min_age != -1 ||
137             revs->max_age != -1)
138                 usage(builtin_diff_usage);
139         if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
140                 perror("read_cache_preload");
141                 return -1;
142         }
143         return run_diff_index(revs, cached);
144 }
145
146 static int builtin_diff_tree(struct rev_info *revs,
147                              int argc, const char **argv,
148                              struct object_array_entry *ent)
149 {
150         const unsigned char *(sha1[2]);
151         int swap = 0;
152
153         if (argc > 1)
154                 usage(builtin_diff_usage);
155
156         /* We saw two trees, ent[0] and ent[1].
157          * if ent[1] is uninteresting, they are swapped
158          */
159         if (ent[1].item->flags & UNINTERESTING)
160                 swap = 1;
161         sha1[swap] = ent[0].item->sha1;
162         sha1[1-swap] = ent[1].item->sha1;
163         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
164         log_tree_diff_flush(revs);
165         return 0;
166 }
167
168 static int builtin_diff_combined(struct rev_info *revs,
169                                  int argc, const char **argv,
170                                  struct object_array_entry *ent,
171                                  int ents)
172 {
173         struct sha1_array parents = SHA1_ARRAY_INIT;
174         int i;
175
176         if (argc > 1)
177                 usage(builtin_diff_usage);
178
179         if (!revs->dense_combined_merges && !revs->combine_merges)
180                 revs->dense_combined_merges = revs->combine_merges = 1;
181         for (i = 1; i < ents; i++)
182                 sha1_array_append(&parents, ent[i].item->sha1);
183         diff_tree_combined(ent[0].item->sha1, &parents,
184                            revs->dense_combined_merges, revs);
185         sha1_array_clear(&parents);
186         return 0;
187 }
188
189 static void refresh_index_quietly(void)
190 {
191         struct lock_file *lock_file;
192         int fd;
193
194         lock_file = xcalloc(1, sizeof(struct lock_file));
195         fd = hold_locked_index(lock_file, 0);
196         if (fd < 0)
197                 return;
198         discard_cache();
199         read_cache();
200         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
201         update_index_if_able(&the_index, lock_file);
202 }
203
204 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
205 {
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.pathspec.raw) < 0) {
236                 perror("read_cache_preload");
237                 return -1;
238         }
239         return run_diff_files(revs, options);
240 }
241
242 int cmd_diff(int argc, const char **argv, const char *prefix)
243 {
244         int i;
245         struct rev_info rev;
246         struct object_array_entry ent[100];
247         int ents = 0, blobs = 0, paths = 0;
248         const char *path = NULL;
249         struct blobinfo blob[2];
250         int nongit;
251         int result = 0;
252
253         /*
254          * We could get N tree-ish in the rev.pending_objects list.
255          * Also there could be M blobs there, and P pathspecs.
256          *
257          * N=0, M=0:
258          *      cache vs files (diff-files)
259          * N=0, M=2:
260          *      compare two random blobs.  P must be zero.
261          * N=0, M=1, P=1:
262          *      compare a blob with a working tree file.
263          *
264          * N=1, M=0:
265          *      tree vs cache (diff-index --cached)
266          *
267          * N=2, M=0:
268          *      tree vs tree (diff-tree)
269          *
270          * N=0, M=0, P=2:
271          *      compare two filesystem entities (aka --no-index).
272          *
273          * Other cases are errors.
274          */
275
276         prefix = setup_git_directory_gently(&nongit);
277         gitmodules_config();
278         git_config(git_diff_ui_config, NULL);
279
280         init_revisions(&rev, prefix);
281
282         /* If this is a no-index diff, just run it and exit there. */
283         diff_no_index(&rev, argc, argv, nongit, prefix);
284
285         /* Otherwise, we are doing the usual "git" diff */
286         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
287
288         /* Scale to real terminal size and respect statGraphWidth config */
289         rev.diffopt.stat_width = -1;
290         rev.diffopt.stat_graph_width = -1;
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                 diff_setup_done(&rev.diffopt);
302         }
303
304         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
305
306         setup_diff_pager(&rev.diffopt);
307
308         /*
309          * Do we have --cached and not have a pending object, then
310          * default to HEAD by hand.  Eek.
311          */
312         if (!rev.pending.nr) {
313                 int i;
314                 for (i = 1; i < argc; i++) {
315                         const char *arg = argv[i];
316                         if (!strcmp(arg, "--"))
317                                 break;
318                         else if (!strcmp(arg, "--cached") ||
319                                  !strcmp(arg, "--staged")) {
320                                 add_head_to_pending(&rev);
321                                 if (!rev.pending.nr) {
322                                         struct tree *tree;
323                                         tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
324                                         add_pending_object(&rev, &tree->object, "HEAD");
325                                 }
326                                 break;
327                         }
328                 }
329         }
330
331         for (i = 0; i < rev.pending.nr; i++) {
332                 struct object_array_entry *list = rev.pending.objects+i;
333                 struct object *obj = list->item;
334                 const char *name = list->name;
335                 int flags = (obj->flags & UNINTERESTING);
336                 if (!obj->parsed)
337                         obj = parse_object(obj->sha1);
338                 obj = deref_tag(obj, NULL, 0);
339                 if (!obj)
340                         die(_("invalid object '%s' given."), name);
341                 if (obj->type == OBJ_COMMIT)
342                         obj = &((struct commit *)obj)->tree->object;
343                 if (obj->type == OBJ_TREE) {
344                         if (ARRAY_SIZE(ent) <= ents)
345                                 die(_("more than %d trees given: '%s'"),
346                                     (int) ARRAY_SIZE(ent), name);
347                         obj->flags |= flags;
348                         ent[ents].item = obj;
349                         ent[ents].name = name;
350                         ents++;
351                         continue;
352                 }
353                 if (obj->type == OBJ_BLOB) {
354                         if (2 <= blobs)
355                                 die(_("more than two blobs given: '%s'"), name);
356                         hashcpy(blob[blobs].sha1, obj->sha1);
357                         blob[blobs].name = name;
358                         blob[blobs].mode = list->mode;
359                         blobs++;
360                         continue;
361
362                 }
363                 die(_("unhandled object '%s' given."), name);
364         }
365         if (rev.prune_data.nr) {
366                 if (!path)
367                         path = rev.prune_data.items[0].match;
368                 paths += rev.prune_data.nr;
369         }
370
371         /*
372          * Now, do the arguments look reasonable?
373          */
374         if (!ents) {
375                 switch (blobs) {
376                 case 0:
377                         result = builtin_diff_files(&rev, argc, argv);
378                         break;
379                 case 1:
380                         if (paths != 1)
381                                 usage(builtin_diff_usage);
382                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
383                         break;
384                 case 2:
385                         if (paths)
386                                 usage(builtin_diff_usage);
387                         result = builtin_diff_blobs(&rev, argc, argv, blob);
388                         break;
389                 default:
390                         usage(builtin_diff_usage);
391                 }
392         }
393         else if (blobs)
394                 usage(builtin_diff_usage);
395         else if (ents == 1)
396                 result = builtin_diff_index(&rev, argc, argv);
397         else if (ents == 2)
398                 result = builtin_diff_tree(&rev, argc, argv, ent);
399         else if (ent[0].item->flags & UNINTERESTING) {
400                 /*
401                  * diff A...B where there is at least one merge base
402                  * between A and B.  We have ent[0] == merge-base,
403                  * ent[ents-2] == A, and ent[ents-1] == B.  Show diff
404                  * between the base and B.  Note that we pick one
405                  * merge base at random if there are more than one.
406                  */
407                 ent[1] = ent[ents-1];
408                 result = builtin_diff_tree(&rev, argc, argv, ent);
409         } else
410                 result = builtin_diff_combined(&rev, argc, argv,
411                                                ent, ents);
412         result = diff_result_code(&rev.diffopt, result);
413         if (1 < rev.diffopt.skip_stat_unmatch)
414                 refresh_index_quietly();
415         return result;
416 }
417
418 void setup_diff_pager(struct diff_options *opt)
419 {
420         /*
421          * If the user asked for our exit code, then either they want --quiet
422          * or --exit-code. We should definitely not bother with a pager in the
423          * former case, as we will generate no output. Since we still properly
424          * report our exit code even when a pager is run, we _could_ run a
425          * pager with --exit-code. But since we have not done so historically,
426          * and because it is easy to find people oneline advising "git diff
427          * --exit-code" in hooks and other scripts, we do not do so.
428          */
429         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
430             check_pager_config("diff") != 0)
431                 setup_pager();
432 }