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"
17 struct blobinfo {
18 unsigned char sha1[20];
19 const char *name;
20 unsigned mode;
21 };
23 static const char builtin_diff_usage[] =
24 "git diff <options> <rev>{0,2} -- <path>*";
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;
35 if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
36 !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
37 return;
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 }
48 if (opt->prefix &&
49 (strncmp(old_name, opt->prefix, opt->prefix_length) ||
50 strncmp(new_name, opt->prefix, opt->prefix_length)))
51 return;
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);
58 diff_queue(&diff_queued_diff, one, two);
59 }
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;
69 if (argc > 1)
70 usage(builtin_diff_usage);
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);
77 if (blob[0].mode == S_IFINVALID)
78 blob[0].mode = canon_mode(st.st_mode);
80 stuff_change(&revs->diffopt,
81 blob[0].mode, canon_mode(st.st_mode),
82 blob[0].sha1, null_sha1,
83 path, path);
84 diffcore_std(&revs->diffopt);
85 diff_flush(&revs->diffopt);
86 return 0;
87 }
89 static int builtin_diff_blobs(struct rev_info *revs,
90 int argc, const char **argv,
91 struct blobinfo *blob)
92 {
93 unsigned mode = canon_mode(S_IFREG | 0644);
95 if (argc > 1)
96 usage(builtin_diff_usage);
98 if (blob[0].mode == S_IFINVALID)
99 blob[0].mode = mode;
101 if (blob[1].mode == S_IFINVALID)
102 blob[1].mode = mode;
104 stuff_change(&revs->diffopt,
105 blob[0].mode, blob[1].mode,
106 blob[0].sha1, blob[1].sha1,
107 blob[0].name, blob[1].name);
108 diffcore_std(&revs->diffopt);
109 diff_flush(&revs->diffopt);
110 return 0;
111 }
113 static int builtin_diff_index(struct rev_info *revs,
114 int argc, const char **argv)
115 {
116 int cached = 0;
117 while (1 < argc) {
118 const char *arg = argv[1];
119 if (!strcmp(arg, "--cached"))
120 cached = 1;
121 else
122 usage(builtin_diff_usage);
123 argv++; argc--;
124 }
125 /*
126 * Make sure there is one revision (i.e. pending object),
127 * and there is no revision filtering parameters.
128 */
129 if (revs->pending.nr != 1 ||
130 revs->max_count != -1 || revs->min_age != -1 ||
131 revs->max_age != -1)
132 usage(builtin_diff_usage);
133 if (read_cache() < 0) {
134 perror("read_cache");
135 return -1;
136 }
137 return run_diff_index(revs, cached);
138 }
140 static int builtin_diff_tree(struct rev_info *revs,
141 int argc, const char **argv,
142 struct object_array_entry *ent)
143 {
144 const unsigned char *(sha1[2]);
145 int swap = 0;
147 if (argc > 1)
148 usage(builtin_diff_usage);
150 /* We saw two trees, ent[0] and ent[1].
151 * if ent[1] is uninteresting, they are swapped
152 */
153 if (ent[1].item->flags & UNINTERESTING)
154 swap = 1;
155 sha1[swap] = ent[0].item->sha1;
156 sha1[1-swap] = ent[1].item->sha1;
157 diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
158 log_tree_diff_flush(revs);
159 return 0;
160 }
162 static int builtin_diff_combined(struct rev_info *revs,
163 int argc, const char **argv,
164 struct object_array_entry *ent,
165 int ents)
166 {
167 const unsigned char (*parent)[20];
168 int i;
170 if (argc > 1)
171 usage(builtin_diff_usage);
173 if (!revs->dense_combined_merges && !revs->combine_merges)
174 revs->dense_combined_merges = revs->combine_merges = 1;
175 parent = xmalloc(ents * sizeof(*parent));
176 /* Again, the revs are all reverse */
177 for (i = 0; i < ents; i++)
178 hashcpy((unsigned char *)(parent + i),
179 ent[ents - 1 - i].item->sha1);
180 diff_tree_combined(parent[0], parent + 1, ents - 1,
181 revs->dense_combined_merges, revs);
182 return 0;
183 }
185 static void refresh_index_quietly(void)
186 {
187 struct lock_file *lock_file;
188 int fd;
190 lock_file = xcalloc(1, sizeof(struct lock_file));
191 fd = hold_locked_index(lock_file, 0);
192 if (fd < 0)
193 return;
194 discard_cache();
195 read_cache();
196 refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
198 if (active_cache_changed &&
199 !write_cache(fd, active_cache, active_nr))
200 commit_locked_index(lock_file);
202 rollback_lock_file(lock_file);
203 }
205 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
206 {
207 int result;
208 unsigned int options = 0;
210 while (1 < argc && argv[1][0] == '-') {
211 if (!strcmp(argv[1], "--base"))
212 revs->max_count = 1;
213 else if (!strcmp(argv[1], "--ours"))
214 revs->max_count = 2;
215 else if (!strcmp(argv[1], "--theirs"))
216 revs->max_count = 3;
217 else if (!strcmp(argv[1], "-q"))
218 options |= DIFF_SILENT_ON_REMOVED;
219 else
220 return error("invalid option: %s", argv[1]);
221 argv++; argc--;
222 }
224 if (revs->max_count == -1 &&
225 (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
226 revs->combine_merges = revs->dense_combined_merges = 1;
228 if (read_cache() < 0) {
229 perror("read_cache");
230 return -1;
231 }
232 result = run_diff_files(revs, options);
233 return diff_result_code(&revs->diffopt, result);
234 }
236 int cmd_diff(int argc, const char **argv, const char *prefix)
237 {
238 int i;
239 struct rev_info rev;
240 struct object_array_entry ent[100];
241 int ents = 0, blobs = 0, paths = 0;
242 const char *path = NULL;
243 struct blobinfo blob[2];
244 int nongit;
245 int result = 0;
247 /*
248 * We could get N tree-ish in the rev.pending_objects list.
249 * Also there could be M blobs there, and P pathspecs.
250 *
251 * N=0, M=0:
252 * cache vs files (diff-files)
253 * N=0, M=2:
254 * compare two random blobs. P must be zero.
255 * N=0, M=1, P=1:
256 * compare a blob with a working tree file.
257 *
258 * N=1, M=0:
259 * tree vs cache (diff-index --cached)
260 *
261 * N=2, M=0:
262 * tree vs tree (diff-tree)
263 *
264 * N=0, M=0, P=2:
265 * compare two filesystem entities (aka --no-index).
266 *
267 * Other cases are errors.
268 */
270 prefix = setup_git_directory_gently(&nongit);
271 git_config(git_diff_ui_config, NULL);
273 if (diff_use_color_default == -1)
274 diff_use_color_default = git_use_color_default;
276 init_revisions(&rev, prefix);
278 /* If this is a no-index diff, just run it and exit there. */
279 diff_no_index(&rev, argc, argv, nongit, prefix);
281 /* Otherwise, we are doing the usual "git" diff */
282 rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
284 if (nongit)
285 die("Not a git repository");
286 argc = setup_revisions(argc, argv, &rev, NULL);
287 if (!rev.diffopt.output_format) {
288 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
289 if (diff_setup_done(&rev.diffopt) < 0)
290 die("diff_setup_done failed");
291 }
292 DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
293 DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
295 /*
296 * If the user asked for our exit code then don't start a
297 * pager or we would end up reporting its exit code instead.
298 */
299 if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
300 check_pager_config("diff") != 0)
301 setup_pager();
303 /*
304 * Do we have --cached and not have a pending object, then
305 * default to HEAD by hand. Eek.
306 */
307 if (!rev.pending.nr) {
308 int i;
309 for (i = 1; i < argc; i++) {
310 const char *arg = argv[i];
311 if (!strcmp(arg, "--"))
312 break;
313 else if (!strcmp(arg, "--cached")) {
314 add_head_to_pending(&rev);
315 if (!rev.pending.nr)
316 die("No HEAD commit to compare with (yet)");
317 break;
318 }
319 }
320 }
322 for (i = 0; i < rev.pending.nr; i++) {
323 struct object_array_entry *list = rev.pending.objects+i;
324 struct object *obj = list->item;
325 const char *name = list->name;
326 int flags = (obj->flags & UNINTERESTING);
327 if (!obj->parsed)
328 obj = parse_object(obj->sha1);
329 obj = deref_tag(obj, NULL, 0);
330 if (!obj)
331 die("invalid object '%s' given.", name);
332 if (obj->type == OBJ_COMMIT)
333 obj = &((struct commit *)obj)->tree->object;
334 if (obj->type == OBJ_TREE) {
335 if (ARRAY_SIZE(ent) <= ents)
336 die("more than %d trees given: '%s'",
337 (int) ARRAY_SIZE(ent), name);
338 obj->flags |= flags;
339 ent[ents].item = obj;
340 ent[ents].name = name;
341 ents++;
342 continue;
343 }
344 if (obj->type == OBJ_BLOB) {
345 if (2 <= blobs)
346 die("more than two blobs given: '%s'", name);
347 hashcpy(blob[blobs].sha1, obj->sha1);
348 blob[blobs].name = name;
349 blob[blobs].mode = list->mode;
350 blobs++;
351 continue;
353 }
354 die("unhandled object '%s' given.", name);
355 }
356 if (rev.prune_data) {
357 const char **pathspec = rev.prune_data;
358 while (*pathspec) {
359 if (!path)
360 path = *pathspec;
361 paths++;
362 pathspec++;
363 }
364 }
366 /*
367 * Now, do the arguments look reasonable?
368 */
369 if (!ents) {
370 switch (blobs) {
371 case 0:
372 result = builtin_diff_files(&rev, argc, argv);
373 break;
374 case 1:
375 if (paths != 1)
376 usage(builtin_diff_usage);
377 result = builtin_diff_b_f(&rev, argc, argv, blob, path);
378 break;
379 case 2:
380 if (paths)
381 usage(builtin_diff_usage);
382 result = builtin_diff_blobs(&rev, argc, argv, blob);
383 break;
384 default:
385 usage(builtin_diff_usage);
386 }
387 }
388 else if (blobs)
389 usage(builtin_diff_usage);
390 else if (ents == 1)
391 result = builtin_diff_index(&rev, argc, argv);
392 else if (ents == 2)
393 result = builtin_diff_tree(&rev, argc, argv, ent);
394 else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
395 /* diff A...B where there is one sane merge base between
396 * A and B. We have ent[0] == merge-base, ent[1] == A,
397 * and ent[2] == B. Show diff between the base and B.
398 */
399 ent[1] = ent[2];
400 result = builtin_diff_tree(&rev, argc, argv, ent);
401 }
402 else
403 result = builtin_diff_combined(&rev, argc, argv,
404 ent, ents);
405 result = diff_result_code(&rev.diffopt, result);
406 if (1 < rev.diffopt.skip_stat_unmatch)
407 refresh_index_quietly();
408 return result;
409 }