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/* NEEDSWORK: struct object has place for name but we _do_
17 * know mode when we extracted the blob out of a tree, which
18 * we currently lose.
19 */
20struct blobinfo {
21 unsigned char sha1[20];
22 const char *name;
23};
24static const char builtin_diff_usage[] =
26"diff <options> <rev>{0,2} -- <path>*";
27static int builtin_diff_files(struct rev_info *revs,
29 int argc, const char **argv)
30{
31 int silent = 0;
32 while (1 < argc) {
33 const char *arg = argv[1];
34 if (!strcmp(arg, "--base"))
35 revs->max_count = 1;
36 else if (!strcmp(arg, "--ours"))
37 revs->max_count = 2;
38 else if (!strcmp(arg, "--theirs"))
39 revs->max_count = 3;
40 else if (!strcmp(arg, "-q"))
41 silent = 1;
42 else
43 usage(builtin_diff_usage);
44 argv++; argc--;
45 }
46 /*
47 * Make sure there are NO revision (i.e. pending object) parameter,
48 * specified rev.max_count is reasonable (0 <= n <= 3), and
49 * there is no other revision filtering parameter.
50 */
51 if (revs->pending.nr ||
52 revs->min_age != -1 ||
53 revs->max_age != -1 ||
54 3 < revs->max_count)
55 usage(builtin_diff_usage);
56 if (revs->max_count < 0 &&
57 (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
58 revs->combine_merges = revs->dense_combined_merges = 1;
59 /*
60 * Backward compatibility wart - "diff-files -s" used to
61 * defeat the common diff option "-s" which asked for
62 * DIFF_FORMAT_NO_OUTPUT.
63 */
64 if (revs->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT)
65 revs->diffopt.output_format = DIFF_FORMAT_RAW;
66 return run_diff_files(revs, silent);
67}
68static void stuff_change(struct diff_options *opt,
70 unsigned old_mode, unsigned new_mode,
71 const unsigned char *old_sha1,
72 const unsigned char *new_sha1,
73 const char *old_name,
74 const char *new_name)
75{
76 struct diff_filespec *one, *two;
77 if (memcmp(null_sha1, old_sha1, 20) &&
79 memcmp(null_sha1, new_sha1, 20) &&
80 !memcmp(old_sha1, new_sha1, 20))
81 return;
82 if (opt->reverse_diff) {
84 unsigned tmp;
85 const unsigned char *tmp_u;
86 const char *tmp_c;
87 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
88 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
89 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
90 }
91 one = alloc_filespec(old_name);
92 two = alloc_filespec(new_name);
93 fill_filespec(one, old_sha1, old_mode);
94 fill_filespec(two, new_sha1, new_mode);
95 /* NEEDSWORK: shouldn't this part of diffopt??? */
97 diff_queue(&diff_queued_diff, one, two);
98}
99static int builtin_diff_b_f(struct rev_info *revs,
101 int argc, const char **argv,
102 struct blobinfo *blob,
103 const char *path)
104{
105 /* Blob vs file in the working tree*/
106 struct stat st;
107 if (argc > 1)
109 usage(builtin_diff_usage);
110 if (lstat(path, &st))
112 die("'%s': %s", path, strerror(errno));
113 if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
114 die("'%s': not a regular file or symlink", path);
115 stuff_change(&revs->diffopt,
116 canon_mode(st.st_mode), canon_mode(st.st_mode),
117 blob[0].sha1, null_sha1,
118 path, path);
119 diffcore_std(&revs->diffopt);
120 diff_flush(&revs->diffopt);
121 return 0;
122}
123static int builtin_diff_blobs(struct rev_info *revs,
125 int argc, const char **argv,
126 struct blobinfo *blob)
127{
128 /* Blobs: the arguments are reversed when setup_revisions()
129 * picked them up.
130 */
131 unsigned mode = canon_mode(S_IFREG | 0644);
132 if (argc > 1)
134 usage(builtin_diff_usage);
135 stuff_change(&revs->diffopt,
137 mode, mode,
138 blob[1].sha1, blob[0].sha1,
139 blob[0].name, blob[0].name);
140 diffcore_std(&revs->diffopt);
141 diff_flush(&revs->diffopt);
142 return 0;
143}
144static int builtin_diff_index(struct rev_info *revs,
146 int argc, const char **argv)
147{
148 int cached = 0;
149 while (1 < argc) {
150 const char *arg = argv[1];
151 if (!strcmp(arg, "--cached"))
152 cached = 1;
153 else
154 usage(builtin_diff_usage);
155 argv++; argc--;
156 }
157 /*
158 * Make sure there is one revision (i.e. pending object),
159 * and there is no revision filtering parameters.
160 */
161 if (revs->pending.nr != 1 ||
162 revs->max_count != -1 || revs->min_age != -1 ||
163 revs->max_age != -1)
164 usage(builtin_diff_usage);
165 return run_diff_index(revs, cached);
166}
167static int builtin_diff_tree(struct rev_info *revs,
169 int argc, const char **argv,
170 struct object_array_entry *ent)
171{
172 const unsigned char *(sha1[2]);
173 int swap = 0;
174 if (argc > 1)
176 usage(builtin_diff_usage);
177 /* We saw two trees, ent[0] and ent[1].
179 * if ent[1] is uninteresting, they are swapped
180 */
181 if (ent[1].item->flags & UNINTERESTING)
182 swap = 1;
183 sha1[swap] = ent[0].item->sha1;
184 sha1[1-swap] = ent[1].item->sha1;
185 diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
186 log_tree_diff_flush(revs);
187 return 0;
188}
189static int builtin_diff_combined(struct rev_info *revs,
191 int argc, const char **argv,
192 struct object_array_entry *ent,
193 int ents)
194{
195 const unsigned char (*parent)[20];
196 int i;
197 if (argc > 1)
199 usage(builtin_diff_usage);
200 if (!revs->dense_combined_merges && !revs->combine_merges)
202 revs->dense_combined_merges = revs->combine_merges = 1;
203 parent = xmalloc(ents * sizeof(*parent));
204 /* Again, the revs are all reverse */
205 for (i = 0; i < ents; i++)
206 memcpy(parent + i, ent[ents - 1 - i].item->sha1, 20);
207 diff_tree_combined(parent[0], parent + 1, ents - 1,
208 revs->dense_combined_merges, revs);
209 return 0;
210}
211void add_head(struct rev_info *revs)
213{
214 unsigned char sha1[20];
215 struct object *obj;
216 if (get_sha1("HEAD", sha1))
217 return;
218 obj = parse_object(sha1);
219 if (!obj)
220 return;
221 add_pending_object(revs, obj, "HEAD");
222}
223int cmd_diff(int argc, const char **argv, const char *prefix)
225{
226 int i;
227 struct rev_info rev;
228 struct object_array_entry ent[100];
229 int ents = 0, blobs = 0, paths = 0;
230 const char *path = NULL;
231 struct blobinfo blob[2];
232 /*
234 * We could get N tree-ish in the rev.pending_objects list.
235 * Also there could be M blobs there, and P pathspecs.
236 *
237 * N=0, M=0:
238 * cache vs files (diff-files)
239 * N=0, M=2:
240 * compare two random blobs. P must be zero.
241 * N=0, M=1, P=1:
242 * compare a blob with a working tree file.
243 *
244 * N=1, M=0:
245 * tree vs cache (diff-index --cached)
246 *
247 * N=2, M=0:
248 * tree vs tree (diff-tree)
249 *
250 * Other cases are errors.
251 */
252 git_config(git_diff_ui_config);
254 init_revisions(&rev, prefix);
255 argc = setup_revisions(argc, argv, &rev, NULL);
257 if (!rev.diffopt.output_format) {
258 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
259 diff_setup_done(&rev.diffopt);
260 }
261 /* Do we have --cached and not have a pending object, then
263 * default to HEAD by hand. Eek.
264 */
265 if (!rev.pending.nr) {
266 int i;
267 for (i = 1; i < argc; i++) {
268 const char *arg = argv[i];
269 if (!strcmp(arg, "--"))
270 break;
271 else if (!strcmp(arg, "--cached")) {
272 add_head(&rev);
273 break;
274 }
275 }
276 }
277 for (i = 0; i < rev.pending.nr; i++) {
279 struct object_array_entry *list = rev.pending.objects+i;
280 struct object *obj = list->item;
281 const char *name = list->name;
282 int flags = (obj->flags & UNINTERESTING);
283 if (!obj->parsed)
284 obj = parse_object(obj->sha1);
285 obj = deref_tag(obj, NULL, 0);
286 if (!obj)
287 die("invalid object '%s' given.", name);
288 if (obj->type == OBJ_COMMIT)
289 obj = &((struct commit *)obj)->tree->object;
290 if (obj->type == OBJ_TREE) {
291 if (ARRAY_SIZE(ent) <= ents)
292 die("more than %d trees given: '%s'",
293 (int) ARRAY_SIZE(ent), name);
294 obj->flags |= flags;
295 ent[ents].item = obj;
296 ent[ents].name = name;
297 ents++;
298 continue;
299 }
300 if (obj->type == OBJ_BLOB) {
301 if (2 <= blobs)
302 die("more than two blobs given: '%s'", name);
303 memcpy(blob[blobs].sha1, obj->sha1, 20);
304 blob[blobs].name = name;
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 return builtin_diff_files(&rev, argc, argv);
328 break;
329 case 1:
330 if (paths != 1)
331 usage(builtin_diff_usage);
332 return builtin_diff_b_f(&rev, argc, argv, blob, path);
333 break;
334 case 2:
335 if (paths)
336 usage(builtin_diff_usage);
337 return 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 return builtin_diff_index(&rev, argc, argv);
347 else if (ents == 2)
348 return 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 return builtin_diff_tree(&rev, argc, argv, ent);
355 }
356 else
357 return builtin_diff_combined(&rev, argc, argv,
358 ent, ents);
359 usage(builtin_diff_usage);
360}