Merge branch 'jc/maint-1.6.0-read-tree-overlay' 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
17 struct blobinfo {
18         unsigned char sha1[20];
19         const char *name;
20         unsigned mode;
21 };
22
23 static const char builtin_diff_usage[] =
24 "git diff <options> <rev>{0,2} -- <path>*";
25
26 static void stuff_change(struct diff_options *opt,
27                          unsigned old_mode, unsigned new_mode,
28                          const unsigned char *old_sha1,
29                          const unsigned char *new_sha1,
30                          const char *old_name,
31                          const char *new_name)
32 {
33         struct diff_filespec *one, *two;
34
35         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
36             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
37                 return;
38
39         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
40                 unsigned tmp;
41                 const unsigned char *tmp_u;
42                 const char *tmp_c;
43                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
44                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
45                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
46         }
47
48         if (opt->prefix &&
49             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
50              strncmp(new_name, opt->prefix, opt->prefix_length)))
51                 return;
52
53         one = alloc_filespec(old_name);
54         two = alloc_filespec(new_name);
55         fill_filespec(one, old_sha1, old_mode);
56         fill_filespec(two, new_sha1, new_mode);
57
58         diff_queue(&diff_queued_diff, one, two);
59 }
60
61 static int builtin_diff_b_f(struct rev_info *revs,
62                             int argc, const char **argv,
63                             struct blobinfo *blob,
64                             const char *path)
65 {
66         /* Blob vs file in the working tree*/
67         struct stat st;
68
69         if (argc > 1)
70                 usage(builtin_diff_usage);
71
72         if (lstat(path, &st))
73                 die("'%s': %s", path, strerror(errno));
74         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
75                 die("'%s': not a regular file or symlink", path);
76
77         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
78
79         if (blob[0].mode == S_IFINVALID)
80                 blob[0].mode = canon_mode(st.st_mode);
81
82         stuff_change(&revs->diffopt,
83                      blob[0].mode, canon_mode(st.st_mode),
84                      blob[0].sha1, null_sha1,
85                      path, path);
86         diffcore_std(&revs->diffopt);
87         diff_flush(&revs->diffopt);
88         return 0;
89 }
90
91 static int builtin_diff_blobs(struct rev_info *revs,
92                               int argc, const char **argv,
93                               struct blobinfo *blob)
94 {
95         unsigned mode = canon_mode(S_IFREG | 0644);
96
97         if (argc > 1)
98                 usage(builtin_diff_usage);
99
100         if (blob[0].mode == S_IFINVALID)
101                 blob[0].mode = mode;
102
103         if (blob[1].mode == S_IFINVALID)
104                 blob[1].mode = mode;
105
106         stuff_change(&revs->diffopt,
107                      blob[0].mode, blob[1].mode,
108                      blob[0].sha1, blob[1].sha1,
109                      blob[0].name, blob[1].name);
110         diffcore_std(&revs->diffopt);
111         diff_flush(&revs->diffopt);
112         return 0;
113 }
114
115 static int builtin_diff_index(struct rev_info *revs,
116                               int argc, const char **argv)
117 {
118         int cached = 0;
119         while (1 < argc) {
120                 const char *arg = argv[1];
121                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
122                         cached = 1;
123                 else
124                         usage(builtin_diff_usage);
125                 argv++; argc--;
126         }
127         if (!cached)
128                 setup_work_tree();
129         /*
130          * Make sure there is one revision (i.e. pending object),
131          * and there is no revision filtering parameters.
132          */
133         if (revs->pending.nr != 1 ||
134             revs->max_count != -1 || revs->min_age != -1 ||
135             revs->max_age != -1)
136                 usage(builtin_diff_usage);
137         if (read_cache_preload(revs->diffopt.paths) < 0) {
138                 perror("read_cache_preload");
139                 return -1;
140         }
141         return run_diff_index(revs, cached);
142 }
143
144 static int builtin_diff_tree(struct rev_info *revs,
145                              int argc, const char **argv,
146                              struct object_array_entry *ent)
147 {
148         const unsigned char *(sha1[2]);
149         int swap = 0;
150
151         if (argc > 1)
152                 usage(builtin_diff_usage);
153
154         /* We saw two trees, ent[0] and ent[1].
155          * if ent[1] is uninteresting, they are swapped
156          */
157         if (ent[1].item->flags & UNINTERESTING)
158                 swap = 1;
159         sha1[swap] = ent[0].item->sha1;
160         sha1[1-swap] = ent[1].item->sha1;
161         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
162         log_tree_diff_flush(revs);
163         return 0;
164 }
165
166 static int builtin_diff_combined(struct rev_info *revs,
167                                  int argc, const char **argv,
168                                  struct object_array_entry *ent,
169                                  int ents)
170 {
171         const unsigned char (*parent)[20];
172         int i;
173
174         if (argc > 1)
175                 usage(builtin_diff_usage);
176
177         if (!revs->dense_combined_merges && !revs->combine_merges)
178                 revs->dense_combined_merges = revs->combine_merges = 1;
179         parent = xmalloc(ents * sizeof(*parent));
180         for (i = 0; i < ents; i++)
181                 hashcpy((unsigned char *)(parent + i), ent[i].item->sha1);
182         diff_tree_combined(parent[0], parent + 1, ents - 1,
183                            revs->dense_combined_merges, revs);
184         return 0;
185 }
186
187 static void refresh_index_quietly(void)
188 {
189         struct lock_file *lock_file;
190         int fd;
191
192         lock_file = xcalloc(1, sizeof(struct lock_file));
193         fd = hold_locked_index(lock_file, 0);
194         if (fd < 0)
195                 return;
196         discard_cache();
197         read_cache();
198         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
199
200         if (active_cache_changed &&
201             !write_cache(fd, active_cache, active_nr))
202                 commit_locked_index(lock_file);
203
204         rollback_lock_file(lock_file);
205 }
206
207 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
208 {
209         int result;
210         unsigned int options = 0;
211
212         while (1 < argc && argv[1][0] == '-') {
213                 if (!strcmp(argv[1], "--base"))
214                         revs->max_count = 1;
215                 else if (!strcmp(argv[1], "--ours"))
216                         revs->max_count = 2;
217                 else if (!strcmp(argv[1], "--theirs"))
218                         revs->max_count = 3;
219                 else if (!strcmp(argv[1], "-q"))
220                         options |= DIFF_SILENT_ON_REMOVED;
221                 else
222                         return error("invalid option: %s", argv[1]);
223                 argv++; argc--;
224         }
225
226         /*
227          * "diff --base" should not combine merges because it was not
228          * asked to.  "diff -c" should not densify (if the user wants
229          * dense one, --cc can be explicitly asked for, or just rely
230          * on the default).
231          */
232         if (revs->max_count == -1 && !revs->combine_merges &&
233             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
234                 revs->combine_merges = revs->dense_combined_merges = 1;
235
236         setup_work_tree();
237         if (read_cache_preload(revs->diffopt.paths) < 0) {
238                 perror("read_cache_preload");
239                 return -1;
240         }
241         result = run_diff_files(revs, options);
242         return diff_result_code(&revs->diffopt, result);
243 }
244
245 int cmd_diff(int argc, const char **argv, const char *prefix)
246 {
247         int i;
248         struct rev_info rev;
249         struct object_array_entry ent[100];
250         int ents = 0, blobs = 0, paths = 0;
251         const char *path = NULL;
252         struct blobinfo blob[2];
253         int nongit;
254         int result = 0;
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          * N=0, M=0, P=2:
274          *      compare two filesystem entities (aka --no-index).
275          *
276          * Other cases are errors.
277          */
278
279         prefix = setup_git_directory_gently(&nongit);
280         git_config(git_diff_ui_config, NULL);
281
282         if (diff_use_color_default == -1)
283                 diff_use_color_default = git_use_color_default;
284
285         init_revisions(&rev, prefix);
286
287         /* If this is a no-index diff, just run it and exit there. */
288         diff_no_index(&rev, argc, argv, nongit, prefix);
289
290         /* Otherwise, we are doing the usual "git" diff */
291         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
292
293         /* Default to let external and textconv be used */
294         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
295         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
296
297         if (nongit)
298                 die("Not a git repository");
299         argc = setup_revisions(argc, argv, &rev, NULL);
300         if (!rev.diffopt.output_format) {
301                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
302                 if (diff_setup_done(&rev.diffopt) < 0)
303                         die("diff_setup_done failed");
304         }
305
306         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
307
308         /*
309          * If the user asked for our exit code then don't start a
310          * pager or we would end up reporting its exit code instead.
311          */
312         if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
313             check_pager_config("diff") != 0)
314                 setup_pager();
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                                         die("No HEAD commit to compare with (yet)");
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) {
371                 const char **pathspec = rev.prune_data;
372                 while (*pathspec) {
373                         if (!path)
374                                 path = *pathspec;
375                         paths++;
376                         pathspec++;
377                 }
378         }
379
380         /*
381          * Now, do the arguments look reasonable?
382          */
383         if (!ents) {
384                 switch (blobs) {
385                 case 0:
386                         result = builtin_diff_files(&rev, argc, argv);
387                         break;
388                 case 1:
389                         if (paths != 1)
390                                 usage(builtin_diff_usage);
391                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
392                         break;
393                 case 2:
394                         if (paths)
395                                 usage(builtin_diff_usage);
396                         result = builtin_diff_blobs(&rev, argc, argv, blob);
397                         break;
398                 default:
399                         usage(builtin_diff_usage);
400                 }
401         }
402         else if (blobs)
403                 usage(builtin_diff_usage);
404         else if (ents == 1)
405                 result = builtin_diff_index(&rev, argc, argv);
406         else if (ents == 2)
407                 result = builtin_diff_tree(&rev, argc, argv, ent);
408         else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
409                 /* diff A...B where there is one sane merge base between
410                  * A and B.  We have ent[0] == merge-base, ent[1] == A,
411                  * and ent[2] == B.  Show diff between the base and B.
412                  */
413                 ent[1] = ent[2];
414                 result = builtin_diff_tree(&rev, argc, argv, ent);
415         }
416         else
417                 result = builtin_diff_combined(&rev, argc, argv,
418                                              ent, ents);
419         result = diff_result_code(&rev.diffopt, result);
420         if (1 < rev.diffopt.skip_stat_unmatch)
421                 refresh_index_quietly();
422         return result;
423 }