Merge branch 'ss/help-htmlpath-config-doc' into maint
[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                          int old_sha1_valid,
33                          int new_sha1_valid,
34                          const char *old_name,
35                          const char *new_name)
36 {
37         struct diff_filespec *one, *two;
38
39         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
40             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
41                 return;
42
43         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
44                 unsigned tmp;
45                 const unsigned char *tmp_u;
46                 const char *tmp_c;
47                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
48                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
49                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
50         }
51
52         if (opt->prefix &&
53             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
54              strncmp(new_name, opt->prefix, opt->prefix_length)))
55                 return;
56
57         one = alloc_filespec(old_name);
58         two = alloc_filespec(new_name);
59         fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
60         fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
61
62         diff_queue(&diff_queued_diff, one, two);
63 }
64
65 static int builtin_diff_b_f(struct rev_info *revs,
66                             int argc, const char **argv,
67                             struct blobinfo *blob,
68                             const char *path)
69 {
70         /* Blob vs file in the working tree*/
71         struct stat st;
72
73         if (argc > 1)
74                 usage(builtin_diff_usage);
75
76         if (lstat(path, &st))
77                 die_errno(_("failed to stat '%s'"), path);
78         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
79                 die(_("'%s': not a regular file or symlink"), path);
80
81         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
82
83         if (blob[0].mode == S_IFINVALID)
84                 blob[0].mode = canon_mode(st.st_mode);
85
86         stuff_change(&revs->diffopt,
87                      blob[0].mode, canon_mode(st.st_mode),
88                      blob[0].sha1, null_sha1,
89                      1, 0,
90                      path, path);
91         diffcore_std(&revs->diffopt);
92         diff_flush(&revs->diffopt);
93         return 0;
94 }
95
96 static int builtin_diff_blobs(struct rev_info *revs,
97                               int argc, const char **argv,
98                               struct blobinfo *blob)
99 {
100         unsigned mode = canon_mode(S_IFREG | 0644);
101
102         if (argc > 1)
103                 usage(builtin_diff_usage);
104
105         if (blob[0].mode == S_IFINVALID)
106                 blob[0].mode = mode;
107
108         if (blob[1].mode == S_IFINVALID)
109                 blob[1].mode = mode;
110
111         stuff_change(&revs->diffopt,
112                      blob[0].mode, blob[1].mode,
113                      blob[0].sha1, blob[1].sha1,
114                      1, 1,
115                      blob[0].name, blob[1].name);
116         diffcore_std(&revs->diffopt);
117         diff_flush(&revs->diffopt);
118         return 0;
119 }
120
121 static int builtin_diff_index(struct rev_info *revs,
122                               int argc, const char **argv)
123 {
124         int cached = 0;
125         while (1 < argc) {
126                 const char *arg = argv[1];
127                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
128                         cached = 1;
129                 else
130                         usage(builtin_diff_usage);
131                 argv++; argc--;
132         }
133         /*
134          * Make sure there is one revision (i.e. pending object),
135          * and there is no revision filtering parameters.
136          */
137         if (revs->pending.nr != 1 ||
138             revs->max_count != -1 || revs->min_age != -1 ||
139             revs->max_age != -1)
140                 usage(builtin_diff_usage);
141         if (!cached) {
142                 setup_work_tree();
143                 if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
144                         perror("read_cache_preload");
145                         return -1;
146                 }
147         } else if (read_cache() < 0) {
148                 perror("read_cache");
149                 return -1;
150         }
151         return run_diff_index(revs, cached);
152 }
153
154 static int builtin_diff_tree(struct rev_info *revs,
155                              int argc, const char **argv,
156                              struct object_array_entry *ent)
157 {
158         const unsigned char *(sha1[2]);
159         int swap = 0;
160
161         if (argc > 1)
162                 usage(builtin_diff_usage);
163
164         /* We saw two trees, ent[0] and ent[1].
165          * if ent[1] is uninteresting, they are swapped
166          */
167         if (ent[1].item->flags & UNINTERESTING)
168                 swap = 1;
169         sha1[swap] = ent[0].item->sha1;
170         sha1[1-swap] = ent[1].item->sha1;
171         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
172         log_tree_diff_flush(revs);
173         return 0;
174 }
175
176 static int builtin_diff_combined(struct rev_info *revs,
177                                  int argc, const char **argv,
178                                  struct object_array_entry *ent,
179                                  int ents)
180 {
181         struct sha1_array parents = SHA1_ARRAY_INIT;
182         int i;
183
184         if (argc > 1)
185                 usage(builtin_diff_usage);
186
187         if (!revs->dense_combined_merges && !revs->combine_merges)
188                 revs->dense_combined_merges = revs->combine_merges = 1;
189         for (i = 1; i < ents; i++)
190                 sha1_array_append(&parents, ent[i].item->sha1);
191         diff_tree_combined(ent[0].item->sha1, &parents,
192                            revs->dense_combined_merges, revs);
193         sha1_array_clear(&parents);
194         return 0;
195 }
196
197 static void refresh_index_quietly(void)
198 {
199         struct lock_file *lock_file;
200         int fd;
201
202         lock_file = xcalloc(1, sizeof(struct lock_file));
203         fd = hold_locked_index(lock_file, 0);
204         if (fd < 0)
205                 return;
206         discard_cache();
207         read_cache();
208         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
209         update_index_if_able(&the_index, lock_file);
210 }
211
212 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
213 {
214         unsigned int options = 0;
215
216         while (1 < argc && argv[1][0] == '-') {
217                 if (!strcmp(argv[1], "--base"))
218                         revs->max_count = 1;
219                 else if (!strcmp(argv[1], "--ours"))
220                         revs->max_count = 2;
221                 else if (!strcmp(argv[1], "--theirs"))
222                         revs->max_count = 3;
223                 else if (!strcmp(argv[1], "-q"))
224                         options |= DIFF_SILENT_ON_REMOVED;
225                 else if (!strcmp(argv[1], "-h"))
226                         usage(builtin_diff_usage);
227                 else
228                         return error(_("invalid option: %s"), argv[1]);
229                 argv++; argc--;
230         }
231
232         /*
233          * "diff --base" should not combine merges because it was not
234          * asked to.  "diff -c" should not densify (if the user wants
235          * dense one, --cc can be explicitly asked for, or just rely
236          * on the default).
237          */
238         if (revs->max_count == -1 && !revs->combine_merges &&
239             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
240                 revs->combine_merges = revs->dense_combined_merges = 1;
241
242         setup_work_tree();
243         if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
244                 perror("read_cache_preload");
245                 return -1;
246         }
247         return run_diff_files(revs, options);
248 }
249
250 int cmd_diff(int argc, const char **argv, const char *prefix)
251 {
252         int i;
253         struct rev_info rev;
254         struct object_array_entry ent[100];
255         int ents = 0, blobs = 0, paths = 0;
256         const char *path = NULL;
257         struct blobinfo blob[2];
258         int nongit;
259         int result = 0;
260
261         /*
262          * We could get N tree-ish in the rev.pending_objects list.
263          * Also there could be M blobs there, and P pathspecs.
264          *
265          * N=0, M=0:
266          *      cache vs files (diff-files)
267          * N=0, M=2:
268          *      compare two random blobs.  P must be zero.
269          * N=0, M=1, P=1:
270          *      compare a blob with a working tree file.
271          *
272          * N=1, M=0:
273          *      tree vs cache (diff-index --cached)
274          *
275          * N=2, M=0:
276          *      tree vs tree (diff-tree)
277          *
278          * N=0, M=0, P=2:
279          *      compare two filesystem entities (aka --no-index).
280          *
281          * Other cases are errors.
282          */
283
284         prefix = setup_git_directory_gently(&nongit);
285         gitmodules_config();
286         git_config(git_diff_ui_config, NULL);
287
288         init_revisions(&rev, prefix);
289
290         /* If this is a no-index diff, just run it and exit there. */
291         diff_no_index(&rev, argc, argv, nongit, prefix);
292
293         /* Otherwise, we are doing the usual "git" diff */
294         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
295
296         /* Scale to real terminal size and respect statGraphWidth config */
297         rev.diffopt.stat_width = -1;
298         rev.diffopt.stat_graph_width = -1;
299
300         /* Default to let external and textconv be used */
301         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
302         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
303
304         if (nongit)
305                 die(_("Not a git repository"));
306         argc = setup_revisions(argc, argv, &rev, NULL);
307         if (!rev.diffopt.output_format) {
308                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
309                 diff_setup_done(&rev.diffopt);
310         }
311
312         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
313
314         setup_diff_pager(&rev.diffopt);
315
316         /*
317          * Do we have --cached and not have a pending object, then
318          * default to HEAD by hand.  Eek.
319          */
320         if (!rev.pending.nr) {
321                 int i;
322                 for (i = 1; i < argc; i++) {
323                         const char *arg = argv[i];
324                         if (!strcmp(arg, "--"))
325                                 break;
326                         else if (!strcmp(arg, "--cached") ||
327                                  !strcmp(arg, "--staged")) {
328                                 add_head_to_pending(&rev);
329                                 if (!rev.pending.nr) {
330                                         struct tree *tree;
331                                         tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
332                                         add_pending_object(&rev, &tree->object, "HEAD");
333                                 }
334                                 break;
335                         }
336                 }
337         }
338
339         for (i = 0; i < rev.pending.nr; i++) {
340                 struct object_array_entry *list = rev.pending.objects+i;
341                 struct object *obj = list->item;
342                 const char *name = list->name;
343                 int flags = (obj->flags & UNINTERESTING);
344                 if (!obj->parsed)
345                         obj = parse_object(obj->sha1);
346                 obj = deref_tag(obj, NULL, 0);
347                 if (!obj)
348                         die(_("invalid object '%s' given."), name);
349                 if (obj->type == OBJ_COMMIT)
350                         obj = &((struct commit *)obj)->tree->object;
351                 if (obj->type == OBJ_TREE) {
352                         if (ARRAY_SIZE(ent) <= ents)
353                                 die(_("more than %d trees given: '%s'"),
354                                     (int) ARRAY_SIZE(ent), name);
355                         obj->flags |= flags;
356                         ent[ents].item = obj;
357                         ent[ents].name = name;
358                         ents++;
359                         continue;
360                 }
361                 if (obj->type == OBJ_BLOB) {
362                         if (2 <= blobs)
363                                 die(_("more than two blobs given: '%s'"), name);
364                         hashcpy(blob[blobs].sha1, obj->sha1);
365                         blob[blobs].name = name;
366                         blob[blobs].mode = list->mode;
367                         blobs++;
368                         continue;
369
370                 }
371                 die(_("unhandled object '%s' given."), name);
372         }
373         if (rev.prune_data.nr) {
374                 if (!path)
375                         path = rev.prune_data.items[0].match;
376                 paths += rev.prune_data.nr;
377         }
378
379         /*
380          * Now, do the arguments look reasonable?
381          */
382         if (!ents) {
383                 switch (blobs) {
384                 case 0:
385                         result = builtin_diff_files(&rev, argc, argv);
386                         break;
387                 case 1:
388                         if (paths != 1)
389                                 usage(builtin_diff_usage);
390                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
391                         break;
392                 case 2:
393                         if (paths)
394                                 usage(builtin_diff_usage);
395                         result = builtin_diff_blobs(&rev, argc, argv, blob);
396                         break;
397                 default:
398                         usage(builtin_diff_usage);
399                 }
400         }
401         else if (blobs)
402                 usage(builtin_diff_usage);
403         else if (ents == 1)
404                 result = builtin_diff_index(&rev, argc, argv);
405         else if (ents == 2)
406                 result = builtin_diff_tree(&rev, argc, argv, ent);
407         else if (ent[0].item->flags & UNINTERESTING) {
408                 /*
409                  * diff A...B where there is at least one merge base
410                  * between A and B.  We have ent[0] == merge-base,
411                  * ent[ents-2] == A, and ent[ents-1] == B.  Show diff
412                  * between the base and B.  Note that we pick one
413                  * merge base at random if there are more than one.
414                  */
415                 ent[1] = ent[ents-1];
416                 result = builtin_diff_tree(&rev, argc, argv, ent);
417         } else
418                 result = builtin_diff_combined(&rev, argc, argv,
419                                                ent, ents);
420         result = diff_result_code(&rev.diffopt, result);
421         if (1 < rev.diffopt.skip_stat_unmatch)
422                 refresh_index_quietly();
423         return result;
424 }