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 if (opt->prefix &&
49 (strncmp(old_name, opt->prefix, opt->prefix_length) ||
50 strncmp(new_name, opt->prefix, opt->prefix_length)))
51 return;
52 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 diff_queue(&diff_queued_diff, one, two);
59}
60static 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 if (argc > 1)
70 usage(builtin_diff_usage);
71 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 if (blob[0].mode == S_IFINVALID)
78 blob[0].mode = canon_mode(st.st_mode);
79 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}
88static 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);
94 if (argc > 1)
96 usage(builtin_diff_usage);
97 if (blob[0].mode == S_IFINVALID)
99 blob[0].mode = mode;
100 if (blob[1].mode == S_IFINVALID)
102 blob[1].mode = mode;
103 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}
112static 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}
139static 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;
146 if (argc > 1)
148 usage(builtin_diff_usage);
149 /* 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}
161static 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;
169 if (argc > 1)
171 usage(builtin_diff_usage);
172 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}
184static void refresh_index_quietly(void)
186{
187 struct lock_file *lock_file;
188 int fd;
189 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);
197 if (active_cache_changed &&
199 !write_cache(fd, active_cache, active_nr))
200 commit_locked_index(lock_file);
201 rollback_lock_file(lock_file);
203}
204int cmd_diff(int argc, const char **argv, const char *prefix)
206{
207 int i;
208 struct rev_info rev;
209 struct object_array_entry ent[100];
210 int ents = 0, blobs = 0, paths = 0;
211 const char *path = NULL;
212 struct blobinfo blob[2];
213 int nongit;
214 int result = 0;
215 /*
217 * We could get N tree-ish in the rev.pending_objects list.
218 * Also there could be M blobs there, and P pathspecs.
219 *
220 * N=0, M=0:
221 * cache vs files (diff-files)
222 * N=0, M=2:
223 * compare two random blobs. P must be zero.
224 * N=0, M=1, P=1:
225 * compare a blob with a working tree file.
226 *
227 * N=1, M=0:
228 * tree vs cache (diff-index --cached)
229 *
230 * N=2, M=0:
231 * tree vs tree (diff-tree)
232 *
233 * Other cases are errors.
234 */
235 prefix = setup_git_directory_gently(&nongit);
237 git_config(git_diff_ui_config);
238 if (diff_use_color_default == -1)
240 diff_use_color_default = git_use_color_default;
241 init_revisions(&rev, prefix);
243 rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
244 if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
246 argc = 0;
247 else
248 argc = setup_revisions(argc, argv, &rev, NULL);
249 if (!rev.diffopt.output_format) {
250 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
251 if (diff_setup_done(&rev.diffopt) < 0)
252 die("diff_setup_done failed");
253 }
254 if (rev.diffopt.prefix && nongit) {
255 rev.diffopt.prefix = NULL;
256 rev.diffopt.prefix_length = 0;
257 }
258 DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
259 DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
260 /*
262 * If the user asked for our exit code then don't start a
263 * pager or we would end up reporting its exit code instead.
264 */
265 if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
266 setup_pager();
267 /* Do we have --cached and not have a pending object, then
269 * default to HEAD by hand. Eek.
270 */
271 if (!rev.pending.nr) {
272 int i;
273 for (i = 1; i < argc; i++) {
274 const char *arg = argv[i];
275 if (!strcmp(arg, "--"))
276 break;
277 else if (!strcmp(arg, "--cached")) {
278 add_head_to_pending(&rev);
279 if (!rev.pending.nr)
280 die("No HEAD commit to compare with (yet)");
281 break;
282 }
283 }
284 }
285 for (i = 0; i < rev.pending.nr; i++) {
287 struct object_array_entry *list = rev.pending.objects+i;
288 struct object *obj = list->item;
289 const char *name = list->name;
290 int flags = (obj->flags & UNINTERESTING);
291 if (!obj->parsed)
292 obj = parse_object(obj->sha1);
293 obj = deref_tag(obj, NULL, 0);
294 if (!obj)
295 die("invalid object '%s' given.", name);
296 if (obj->type == OBJ_COMMIT)
297 obj = &((struct commit *)obj)->tree->object;
298 if (obj->type == OBJ_TREE) {
299 if (ARRAY_SIZE(ent) <= ents)
300 die("more than %d trees given: '%s'",
301 (int) ARRAY_SIZE(ent), name);
302 obj->flags |= flags;
303 ent[ents].item = obj;
304 ent[ents].name = name;
305 ents++;
306 continue;
307 }
308 if (obj->type == OBJ_BLOB) {
309 if (2 <= blobs)
310 die("more than two blobs given: '%s'", name);
311 hashcpy(blob[blobs].sha1, obj->sha1);
312 blob[blobs].name = name;
313 blob[blobs].mode = list->mode;
314 blobs++;
315 continue;
316 }
318 die("unhandled object '%s' given.", name);
319 }
320 if (rev.prune_data) {
321 const char **pathspec = rev.prune_data;
322 while (*pathspec) {
323 if (!path)
324 path = *pathspec;
325 paths++;
326 pathspec++;
327 }
328 }
329 /*
331 * Now, do the arguments look reasonable?
332 */
333 if (!ents) {
334 switch (blobs) {
335 case 0:
336 result = run_diff_files_cmd(&rev, argc, argv);
337 break;
338 case 1:
339 if (paths != 1)
340 usage(builtin_diff_usage);
341 result = builtin_diff_b_f(&rev, argc, argv, blob, path);
342 break;
343 case 2:
344 if (paths)
345 usage(builtin_diff_usage);
346 result = builtin_diff_blobs(&rev, argc, argv, blob);
347 break;
348 default:
349 usage(builtin_diff_usage);
350 }
351 }
352 else if (blobs)
353 usage(builtin_diff_usage);
354 else if (ents == 1)
355 result = builtin_diff_index(&rev, argc, argv);
356 else if (ents == 2)
357 result = builtin_diff_tree(&rev, argc, argv, ent);
358 else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
359 /* diff A...B where there is one sane merge base between
360 * A and B. We have ent[0] == merge-base, ent[1] == A,
361 * and ent[2] == B. Show diff between the base and B.
362 */
363 ent[1] = ent[2];
364 result = builtin_diff_tree(&rev, argc, argv, ent);
365 }
366 else
367 result = builtin_diff_combined(&rev, argc, argv,
368 ent, ents);
369 result = diff_result_code(&rev.diffopt, result);
370 if (1 < rev.diffopt.skip_stat_unmatch)
371 refresh_index_quietly();
372 return result;
373}