git-diff: resurrect the traditional empty "diff --git" behaviour
[git/git.git] / builtin-diff.c
CommitLineData
65056021
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1/*
2 * Builtin "git diff"
3 *
4 * Copyright (c) 2006 Junio C Hamano
5 */
6#include "cache.h"
7#include "commit.h"
8#include "blob.h"
9#include "tag.h"
10#include "diff.h"
11#include "diffcore.h"
12#include "revision.h"
13#include "log-tree.h"
14#include "builtin.h"
15
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16struct blobinfo {
17 unsigned char sha1[20];
18 const char *name;
01618a3a 19 unsigned mode;
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20};
21
22static const char builtin_diff_usage[] =
15e593e4 23"git-diff <options> <rev>{0,2} -- <path>*";
65056021 24
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25static void stuff_change(struct diff_options *opt,
26 unsigned old_mode, unsigned new_mode,
27 const unsigned char *old_sha1,
28 const unsigned char *new_sha1,
29 const char *old_name,
30 const char *new_name)
31{
32 struct diff_filespec *one, *two;
33
0bef57ee 34 if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
43342941 35 !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
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36 return;
37
38 if (opt->reverse_diff) {
39 unsigned tmp;
d92f1dc6 40 const unsigned char *tmp_u;
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41 const char *tmp_c;
42 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
43 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
44 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
45 }
46 one = alloc_filespec(old_name);
47 two = alloc_filespec(new_name);
48 fill_filespec(one, old_sha1, old_mode);
49 fill_filespec(two, new_sha1, new_mode);
50
51 /* NEEDSWORK: shouldn't this part of diffopt??? */
52 diff_queue(&diff_queued_diff, one, two);
53}
54
55static int builtin_diff_b_f(struct rev_info *revs,
56 int argc, const char **argv,
57 struct blobinfo *blob,
58 const char *path)
59{
60 /* Blob vs file in the working tree*/
61 struct stat st;
62
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63 if (argc > 1)
64 usage(builtin_diff_usage);
65
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66 if (lstat(path, &st))
67 die("'%s': %s", path, strerror(errno));
68 if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
69 die("'%s': not a regular file or symlink", path);
01618a3a
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70
71 if (blob[0].mode == S_IFINVALID)
72 blob[0].mode = canon_mode(st.st_mode);
73
65056021 74 stuff_change(&revs->diffopt,
01618a3a 75 blob[0].mode, canon_mode(st.st_mode),
65056021 76 blob[0].sha1, null_sha1,
065e0b12 77 path, path);
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78 diffcore_std(&revs->diffopt);
79 diff_flush(&revs->diffopt);
80 return 0;
81}
82
83static int builtin_diff_blobs(struct rev_info *revs,
84 int argc, const char **argv,
85 struct blobinfo *blob)
86{
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87 unsigned mode = canon_mode(S_IFREG | 0644);
88
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89 if (argc > 1)
90 usage(builtin_diff_usage);
91
01618a3a
MK
92 if (blob[0].mode == S_IFINVALID)
93 blob[0].mode = mode;
94
95 if (blob[1].mode == S_IFINVALID)
96 blob[1].mode = mode;
97
65056021 98 stuff_change(&revs->diffopt,
01618a3a 99 blob[0].mode, blob[1].mode,
f82cd3c6 100 blob[0].sha1, blob[1].sha1,
53dd8a9c 101 blob[0].name, blob[1].name);
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102 diffcore_std(&revs->diffopt);
103 diff_flush(&revs->diffopt);
104 return 0;
105}
106
107static int builtin_diff_index(struct rev_info *revs,
108 int argc, const char **argv)
109{
110 int cached = 0;
111 while (1 < argc) {
112 const char *arg = argv[1];
f2dd1c9a 113 if (!strcmp(arg, "--cached"))
65056021 114 cached = 1;
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115 else
116 usage(builtin_diff_usage);
117 argv++; argc--;
118 }
119 /*
120 * Make sure there is one revision (i.e. pending object),
121 * and there is no revision filtering parameters.
122 */
1f1e895f 123 if (revs->pending.nr != 1 ||
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124 revs->max_count != -1 || revs->min_age != -1 ||
125 revs->max_age != -1)
126 usage(builtin_diff_usage);
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127 if (read_cache() < 0) {
128 perror("read_cache");
129 return -1;
130 }
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131 return run_diff_index(revs, cached);
132}
133
134static int builtin_diff_tree(struct rev_info *revs,
135 int argc, const char **argv,
1f1e895f 136 struct object_array_entry *ent)
65056021 137{
65056021 138 const unsigned char *(sha1[2]);
1f1e895f 139 int swap = 0;
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140
141 if (argc > 1)
142 usage(builtin_diff_usage);
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143
144 /* We saw two trees, ent[0] and ent[1].
82e5a82f 145 * if ent[1] is uninteresting, they are swapped
0fe7c1de 146 */
1f1e895f
LT
147 if (ent[1].item->flags & UNINTERESTING)
148 swap = 1;
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149 sha1[swap] = ent[0].item->sha1;
150 sha1[1-swap] = ent[1].item->sha1;
151 diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
152 log_tree_diff_flush(revs);
153 return 0;
154}
155
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156static int builtin_diff_combined(struct rev_info *revs,
157 int argc, const char **argv,
1f1e895f 158 struct object_array_entry *ent,
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159 int ents)
160{
161 const unsigned char (*parent)[20];
162 int i;
163
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164 if (argc > 1)
165 usage(builtin_diff_usage);
166
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167 if (!revs->dense_combined_merges && !revs->combine_merges)
168 revs->dense_combined_merges = revs->combine_merges = 1;
169 parent = xmalloc(ents * sizeof(*parent));
170 /* Again, the revs are all reverse */
171 for (i = 0; i < ents; i++)
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172 hashcpy((unsigned char *)(parent + i),
173 ent[ents - 1 - i].item->sha1);
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174 diff_tree_combined(parent[0], parent + 1, ents - 1,
175 revs->dense_combined_merges, revs);
176 return 0;
177}
178
e686eb98 179void add_head(struct rev_info *revs)
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180{
181 unsigned char sha1[20];
182 struct object *obj;
183 if (get_sha1("HEAD", sha1))
184 return;
185 obj = parse_object(sha1);
186 if (!obj)
187 return;
1f1e895f 188 add_pending_object(revs, obj, "HEAD");
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189}
190
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191static void refresh_index_quietly(void)
192{
193 struct lock_file *lock_file;
194 int fd;
195
196 lock_file = xcalloc(1, sizeof(struct lock_file));
197 fd = hold_locked_index(lock_file, 0);
198 if (fd < 0)
199 return;
200 discard_cache();
201 read_cache();
202 refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
203 if (active_cache_changed) {
204 if (write_cache(fd, active_cache, active_nr) ||
205 close(fd) ||
206 commit_locked_index(lock_file))
207 ; /*
208 * silently ignore it -- we haven't mucked
209 * with the real index.
210 */
211 }
212 rollback_lock_file(lock_file);
213}
214
a633fca0 215int cmd_diff(int argc, const char **argv, const char *prefix)
65056021 216{
1f1e895f 217 int i;
65056021 218 struct rev_info rev;
1f1e895f 219 struct object_array_entry ent[100];
65056021 220 int ents = 0, blobs = 0, paths = 0;
a633fca0 221 const char *path = NULL;
65056021 222 struct blobinfo blob[2];
d516c2d1 223 int nongit = 0;
41bbf9d5 224 int result = 0;
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225
226 /*
227 * We could get N tree-ish in the rev.pending_objects list.
228 * Also there could be M blobs there, and P pathspecs.
229 *
230 * N=0, M=0:
231 * cache vs files (diff-files)
232 * N=0, M=2:
233 * compare two random blobs. P must be zero.
234 * N=0, M=1, P=1:
235 * compare a blob with a working tree file.
236 *
237 * N=1, M=0:
238 * tree vs cache (diff-index --cached)
239 *
240 * N=2, M=0:
241 * tree vs tree (diff-tree)
242 *
243 * Other cases are errors.
244 */
230f544e 245
d516c2d1 246 prefix = setup_git_directory_gently(&nongit);
ef1d9c5a 247 git_config(git_diff_ui_config);
db6296a5 248 init_revisions(&rev, prefix);
aecbf914 249 rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
65056021 250
fcfa33ec
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251 if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
252 argc = 0;
253 else
254 argc = setup_revisions(argc, argv, &rev, NULL);
047fbe90 255 if (!rev.diffopt.output_format) {
c9b5ef99 256 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
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257 if (diff_setup_done(&rev.diffopt) < 0)
258 die("diff_setup_done failed");
047fbe90 259 }
f1af60bd 260 rev.diffopt.allow_external = 1;
82cb8afa 261 rev.diffopt.recursive = 1;
c9b5ef99 262
89d07f75
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263 /* If the user asked for our exit code then don't start a
264 * pager or we would end up reporting its exit code instead.
265 */
266 if (!rev.diffopt.exit_with_status)
267 setup_pager();
268
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269 /* Do we have --cached and not have a pending object, then
270 * default to HEAD by hand. Eek.
271 */
1f1e895f 272 if (!rev.pending.nr) {
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273 int i;
274 for (i = 1; i < argc; i++) {
275 const char *arg = argv[i];
276 if (!strcmp(arg, "--"))
277 break;
278 else if (!strcmp(arg, "--cached")) {
279 add_head(&rev);
6c09c451
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280 if (!rev.pending.nr)
281 die("No HEAD commit to compare with (yet)");
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282 break;
283 }
284 }
285 }
286
1f1e895f
LT
287 for (i = 0; i < rev.pending.nr; i++) {
288 struct object_array_entry *list = rev.pending.objects+i;
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289 struct object *obj = list->item;
290 const char *name = list->name;
291 int flags = (obj->flags & UNINTERESTING);
292 if (!obj->parsed)
293 obj = parse_object(obj->sha1);
294 obj = deref_tag(obj, NULL, 0);
295 if (!obj)
296 die("invalid object '%s' given.", name);
1974632c 297 if (obj->type == OBJ_COMMIT)
65056021 298 obj = &((struct commit *)obj)->tree->object;
1974632c 299 if (obj->type == OBJ_TREE) {
0fe7c1de
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300 if (ARRAY_SIZE(ent) <= ents)
301 die("more than %d trees given: '%s'",
334b506a 302 (int) ARRAY_SIZE(ent), name);
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303 obj->flags |= flags;
304 ent[ents].item = obj;
305 ent[ents].name = name;
306 ents++;
307 continue;
308 }
1974632c 309 if (obj->type == OBJ_BLOB) {
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310 if (2 <= blobs)
311 die("more than two blobs given: '%s'", name);
e702496e 312 hashcpy(blob[blobs].sha1, obj->sha1);
65056021 313 blob[blobs].name = name;
01618a3a 314 blob[blobs].mode = list->mode;
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315 blobs++;
316 continue;
230f544e 317
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318 }
319 die("unhandled object '%s' given.", name);
320 }
321 if (rev.prune_data) {
322 const char **pathspec = rev.prune_data;
323 while (*pathspec) {
324 if (!path)
325 path = *pathspec;
326 paths++;
327 pathspec++;
328 }
329 }
330
331 /*
332 * Now, do the arguments look reasonable?
333 */
334 if (!ents) {
335 switch (blobs) {
336 case 0:
41bbf9d5 337 result = run_diff_files_cmd(&rev, argc, argv);
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338 break;
339 case 1:
340 if (paths != 1)
341 usage(builtin_diff_usage);
41bbf9d5 342 result = builtin_diff_b_f(&rev, argc, argv, blob, path);
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343 break;
344 case 2:
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345 if (paths)
346 usage(builtin_diff_usage);
41bbf9d5 347 result = builtin_diff_blobs(&rev, argc, argv, blob);
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348 break;
349 default:
350 usage(builtin_diff_usage);
351 }
352 }
353 else if (blobs)
354 usage(builtin_diff_usage);
355 else if (ents == 1)
41bbf9d5 356 result = builtin_diff_index(&rev, argc, argv);
65056021 357 else if (ents == 2)
41bbf9d5 358 result = builtin_diff_tree(&rev, argc, argv, ent);
9919f41c
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359 else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
360 /* diff A...B where there is one sane merge base between
361 * A and B. We have ent[0] == merge-base, ent[1] == A,
362 * and ent[2] == B. Show diff between the base and B.
363 */
306ea2df 364 ent[1] = ent[2];
41bbf9d5 365 result = builtin_diff_tree(&rev, argc, argv, ent);
9919f41c 366 }
0fe7c1de 367 else
41bbf9d5 368 result = builtin_diff_combined(&rev, argc, argv,
9919f41c 369 ent, ents);
41bbf9d5
AR
370 if (rev.diffopt.exit_with_status)
371 result = rev.diffopt.has_changes;
fb13227e 372
aecbf914
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373 if (1 < rev.diffopt.skip_stat_unmatch)
374 refresh_index_quietly();
41bbf9d5 375 return result;
65056021 376}