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"
16struct blobinfo {
18 unsigned char sha1[20];
19 const char *name;
20 unsigned mode;
21};
22static const char builtin_diff_usage[] =
24"git-diff <options> <rev>{0,2} -- <path>*";
25static 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 if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
36 !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
37 return;
38 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 one = alloc_filespec(old_name);
48 two = alloc_filespec(new_name);
49 fill_filespec(one, old_sha1, old_mode);
50 fill_filespec(two, new_sha1, new_mode);
51 /* NEEDSWORK: shouldn't this part of diffopt??? */
53 diff_queue(&diff_queued_diff, one, two);
54}
55static int builtin_diff_b_f(struct rev_info *revs,
57 int argc, const char **argv,
58 struct blobinfo *blob,
59 const char *path)
60{
61 /* Blob vs file in the working tree*/
62 struct stat st;
63 if (argc > 1)
65 usage(builtin_diff_usage);
66 if (lstat(path, &st))
68 die("'%s': %s", path, strerror(errno));
69 if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
70 die("'%s': not a regular file or symlink", path);
71 if (blob[0].mode == S_IFINVALID)
73 blob[0].mode = canon_mode(st.st_mode);
74 stuff_change(&revs->diffopt,
76 blob[0].mode, canon_mode(st.st_mode),
77 blob[0].sha1, null_sha1,
78 path, path);
79 diffcore_std(&revs->diffopt);
80 diff_flush(&revs->diffopt);
81 return 0;
82}
83static int builtin_diff_blobs(struct rev_info *revs,
85 int argc, const char **argv,
86 struct blobinfo *blob)
87{
88 unsigned mode = canon_mode(S_IFREG | 0644);
89 if (argc > 1)
91 usage(builtin_diff_usage);
92 if (blob[0].mode == S_IFINVALID)
94 blob[0].mode = mode;
95 if (blob[1].mode == S_IFINVALID)
97 blob[1].mode = mode;
98 stuff_change(&revs->diffopt,
100 blob[0].mode, blob[1].mode,
101 blob[0].sha1, blob[1].sha1,
102 blob[0].name, blob[1].name);
103 diffcore_std(&revs->diffopt);
104 diff_flush(&revs->diffopt);
105 return 0;
106}
107static int builtin_diff_index(struct rev_info *revs,
109 int argc, const char **argv)
110{
111 int cached = 0;
112 while (1 < argc) {
113 const char *arg = argv[1];
114 if (!strcmp(arg, "--cached"))
115 cached = 1;
116 else
117 usage(builtin_diff_usage);
118 argv++; argc--;
119 }
120 /*
121 * Make sure there is one revision (i.e. pending object),
122 * and there is no revision filtering parameters.
123 */
124 if (revs->pending.nr != 1 ||
125 revs->max_count != -1 || revs->min_age != -1 ||
126 revs->max_age != -1)
127 usage(builtin_diff_usage);
128 if (read_cache() < 0) {
129 perror("read_cache");
130 return -1;
131 }
132 return run_diff_index(revs, cached);
133}
134static int builtin_diff_tree(struct rev_info *revs,
136 int argc, const char **argv,
137 struct object_array_entry *ent)
138{
139 const unsigned char *(sha1[2]);
140 int swap = 0;
141 if (argc > 1)
143 usage(builtin_diff_usage);
144 /* We saw two trees, ent[0] and ent[1].
146 * if ent[1] is uninteresting, they are swapped
147 */
148 if (ent[1].item->flags & UNINTERESTING)
149 swap = 1;
150 sha1[swap] = ent[0].item->sha1;
151 sha1[1-swap] = ent[1].item->sha1;
152 diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
153 log_tree_diff_flush(revs);
154 return 0;
155}
156static int builtin_diff_combined(struct rev_info *revs,
158 int argc, const char **argv,
159 struct object_array_entry *ent,
160 int ents)
161{
162 const unsigned char (*parent)[20];
163 int i;
164 if (argc > 1)
166 usage(builtin_diff_usage);
167 if (!revs->dense_combined_merges && !revs->combine_merges)
169 revs->dense_combined_merges = revs->combine_merges = 1;
170 parent = xmalloc(ents * sizeof(*parent));
171 /* Again, the revs are all reverse */
172 for (i = 0; i < ents; i++)
173 hashcpy((unsigned char *)(parent + i),
174 ent[ents - 1 - i].item->sha1);
175 diff_tree_combined(parent[0], parent + 1, ents - 1,
176 revs->dense_combined_merges, revs);
177 return 0;
178}
179static void refresh_index_quietly(void)
181{
182 struct lock_file *lock_file;
183 int fd;
184 lock_file = xcalloc(1, sizeof(struct lock_file));
186 fd = hold_locked_index(lock_file, 0);
187 if (fd < 0)
188 return;
189 discard_cache();
190 read_cache();
191 refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
192 if (active_cache_changed &&
194 !write_cache(fd, active_cache, active_nr))
195 commit_locked_index(lock_file);
196 rollback_lock_file(lock_file);
198}
199int cmd_diff(int argc, const char **argv, const char *prefix)
201{
202 int i;
203 struct rev_info rev;
204 struct object_array_entry ent[100];
205 int ents = 0, blobs = 0, paths = 0;
206 const char *path = NULL;
207 struct blobinfo blob[2];
208 int nongit = 0;
209 int result = 0;
210 /*
212 * We could get N tree-ish in the rev.pending_objects list.
213 * Also there could be M blobs there, and P pathspecs.
214 *
215 * N=0, M=0:
216 * cache vs files (diff-files)
217 * N=0, M=2:
218 * compare two random blobs. P must be zero.
219 * N=0, M=1, P=1:
220 * compare a blob with a working tree file.
221 *
222 * N=1, M=0:
223 * tree vs cache (diff-index --cached)
224 *
225 * N=2, M=0:
226 * tree vs tree (diff-tree)
227 *
228 * Other cases are errors.
229 */
230 prefix = setup_git_directory_gently(&nongit);
232 git_config(git_diff_ui_config);
233 if (diff_use_color_default == -1)
235 diff_use_color_default = git_use_color_default;
236 init_revisions(&rev, prefix);
238 rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
239 if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
241 argc = 0;
242 else
243 argc = setup_revisions(argc, argv, &rev, NULL);
244 if (!rev.diffopt.output_format) {
245 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
246 if (diff_setup_done(&rev.diffopt) < 0)
247 die("diff_setup_done failed");
248 }
249 DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
250 DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
251 /*
253 * If the user asked for our exit code then don't start a
254 * pager or we would end up reporting its exit code instead.
255 */
256 if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
257 setup_pager();
258 /* Do we have --cached and not have a pending object, then
260 * default to HEAD by hand. Eek.
261 */
262 if (!rev.pending.nr) {
263 int i;
264 for (i = 1; i < argc; i++) {
265 const char *arg = argv[i];
266 if (!strcmp(arg, "--"))
267 break;
268 else if (!strcmp(arg, "--cached")) {
269 add_head_to_pending(&rev);
270 if (!rev.pending.nr)
271 die("No HEAD commit to compare with (yet)");
272 break;
273 }
274 }
275 }
276 for (i = 0; i < rev.pending.nr; i++) {
278 struct object_array_entry *list = rev.pending.objects+i;
279 struct object *obj = list->item;
280 const char *name = list->name;
281 int flags = (obj->flags & UNINTERESTING);
282 if (!obj->parsed)
283 obj = parse_object(obj->sha1);
284 obj = deref_tag(obj, NULL, 0);
285 if (!obj)
286 die("invalid object '%s' given.", name);
287 if (obj->type == OBJ_COMMIT)
288 obj = &((struct commit *)obj)->tree->object;
289 if (obj->type == OBJ_TREE) {
290 if (ARRAY_SIZE(ent) <= ents)
291 die("more than %d trees given: '%s'",
292 (int) ARRAY_SIZE(ent), name);
293 obj->flags |= flags;
294 ent[ents].item = obj;
295 ent[ents].name = name;
296 ents++;
297 continue;
298 }
299 if (obj->type == OBJ_BLOB) {
300 if (2 <= blobs)
301 die("more than two blobs given: '%s'", name);
302 hashcpy(blob[blobs].sha1, obj->sha1);
303 blob[blobs].name = name;
304 blob[blobs].mode = list->mode;
305 blobs++;
306 continue;
307 }
309 die("unhandled object '%s' given.", name);
310 }
311 if (rev.prune_data) {
312 const char **pathspec = rev.prune_data;
313 while (*pathspec) {
314 if (!path)
315 path = *pathspec;
316 paths++;
317 pathspec++;
318 }
319 }
320 /*
322 * Now, do the arguments look reasonable?
323 */
324 if (!ents) {
325 switch (blobs) {
326 case 0:
327 result = run_diff_files_cmd(&rev, argc, argv);
328 break;
329 case 1:
330 if (paths != 1)
331 usage(builtin_diff_usage);
332 result = builtin_diff_b_f(&rev, argc, argv, blob, path);
333 break;
334 case 2:
335 if (paths)
336 usage(builtin_diff_usage);
337 result = builtin_diff_blobs(&rev, argc, argv, blob);
338 break;
339 default:
340 usage(builtin_diff_usage);
341 }
342 }
343 else if (blobs)
344 usage(builtin_diff_usage);
345 else if (ents == 1)
346 result = builtin_diff_index(&rev, argc, argv);
347 else if (ents == 2)
348 result = builtin_diff_tree(&rev, argc, argv, ent);
349 else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
350 /* diff A...B where there is one sane merge base between
351 * A and B. We have ent[0] == merge-base, ent[1] == A,
352 * and ent[2] == B. Show diff between the base and B.
353 */
354 ent[1] = ent[2];
355 result = builtin_diff_tree(&rev, argc, argv, ent);
356 }
357 else
358 result = builtin_diff_combined(&rev, argc, argv,
359 ent, ents);
360 result = diff_result_code(&rev.diffopt, result);
361 if (1 < rev.diffopt.skip_stat_unmatch)
362 refresh_index_quietly();
363 return result;
364}