t9903: Don't fail when run from path accessed through symlink
[alt-git.git] / builtin / diff.c
blob8c2af6cb43ca62f253e07903a8e3cce1080e335b
1 /*
2 * Builtin "git diff"
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"
19 struct blobinfo {
20 unsigned char sha1[20];
21 const char *name;
22 unsigned mode;
25 static const char builtin_diff_usage[] =
26 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
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)
37 struct diff_filespec *one, *two;
39 if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
40 !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
41 return;
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;
52 if (opt->prefix &&
53 (strncmp(old_name, opt->prefix, opt->prefix_length) ||
54 strncmp(new_name, opt->prefix, opt->prefix_length)))
55 return;
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);
62 diff_queue(&diff_queued_diff, one, two);
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)
70 /* Blob vs file in the working tree*/
71 struct stat st;
73 if (argc > 1)
74 usage(builtin_diff_usage);
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);
81 diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
83 if (blob[0].mode == S_IFINVALID)
84 blob[0].mode = canon_mode(st.st_mode);
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;
96 static int builtin_diff_blobs(struct rev_info *revs,
97 int argc, const char **argv,
98 struct blobinfo *blob)
100 unsigned mode = canon_mode(S_IFREG | 0644);
102 if (argc > 1)
103 usage(builtin_diff_usage);
105 if (blob[0].mode == S_IFINVALID)
106 blob[0].mode = mode;
108 if (blob[1].mode == S_IFINVALID)
109 blob[1].mode = mode;
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;
121 static int builtin_diff_index(struct rev_info *revs,
122 int argc, const char **argv)
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--;
134 * Make sure there is one revision (i.e. pending object),
135 * and there is no revision filtering parameters.
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;
147 } else if (read_cache() < 0) {
148 perror("read_cache");
149 return -1;
151 return run_diff_index(revs, cached);
154 static int builtin_diff_tree(struct rev_info *revs,
155 int argc, const char **argv,
156 struct object_array_entry *ent)
158 const unsigned char *(sha1[2]);
159 int swap = 0;
161 if (argc > 1)
162 usage(builtin_diff_usage);
164 /* We saw two trees, ent[0] and ent[1].
165 * if ent[1] is uninteresting, they are swapped
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;
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)
181 struct sha1_array parents = SHA1_ARRAY_INIT;
182 int i;
184 if (argc > 1)
185 usage(builtin_diff_usage);
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;
197 static void refresh_index_quietly(void)
199 struct lock_file *lock_file;
200 int fd;
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);
212 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
214 unsigned int options = 0;
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--;
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).
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;
242 setup_work_tree();
243 if (read_cache_preload(revs->diffopt.pathspec.raw) < 0) {
244 perror("read_cache_preload");
245 return -1;
247 return run_diff_files(revs, options);
250 int cmd_diff(int argc, const char **argv, const char *prefix)
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;
262 * We could get N tree-ish in the rev.pending_objects list.
263 * Also there could be M blobs there, and P pathspecs.
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.
272 * N=1, M=0:
273 * tree vs cache (diff-index --cached)
275 * N=2, M=0:
276 * tree vs tree (diff-tree)
278 * N=0, M=0, P=2:
279 * compare two filesystem entities (aka --no-index).
281 * Other cases are errors.
284 prefix = setup_git_directory_gently(&nongit);
285 gitmodules_config();
286 git_config(git_diff_ui_config, NULL);
288 init_revisions(&rev, prefix);
290 /* If this is a no-index diff, just run it and exit there. */
291 diff_no_index(&rev, argc, argv, nongit, prefix);
293 /* Otherwise, we are doing the usual "git" diff */
294 rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
296 /* Scale to real terminal size and respect statGraphWidth config */
297 rev.diffopt.stat_width = -1;
298 rev.diffopt.stat_graph_width = -1;
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);
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);
312 DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
314 setup_diff_pager(&rev.diffopt);
317 * Do we have --cached and not have a pending object, then
318 * default to HEAD by hand. Eek.
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");
334 break;
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;
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;
371 die(_("unhandled object '%s' given."), name);
373 if (rev.prune_data.nr) {
374 if (!path)
375 path = rev.prune_data.items[0].match;
376 paths += rev.prune_data.nr;
380 * Now, do the arguments look reasonable?
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);
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) {
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.
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;