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 return run_diff_files(revs, silent);
60}
61static void stuff_change(struct diff_options *opt,
63 unsigned old_mode, unsigned new_mode,
64 const unsigned char *old_sha1,
65 const unsigned char *new_sha1,
66 const char *old_name,
67 const char *new_name)
68{
69 struct diff_filespec *one, *two;
70 if (memcmp(null_sha1, old_sha1, 20) &&
72 memcmp(null_sha1, new_sha1, 20) &&
73 !memcmp(old_sha1, new_sha1, 20))
74 return;
75 if (opt->reverse_diff) {
77 unsigned tmp;
78 const unsigned char *tmp_u;
79 const char *tmp_c;
80 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
81 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
82 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
83 }
84 one = alloc_filespec(old_name);
85 two = alloc_filespec(new_name);
86 fill_filespec(one, old_sha1, old_mode);
87 fill_filespec(two, new_sha1, new_mode);
88 /* NEEDSWORK: shouldn't this part of diffopt??? */
90 diff_queue(&diff_queued_diff, one, two);
91}
92static int builtin_diff_b_f(struct rev_info *revs,
94 int argc, const char **argv,
95 struct blobinfo *blob,
96 const char *path)
97{
98 /* Blob vs file in the working tree*/
99 struct stat st;
100 if (argc > 1)
102 usage(builtin_diff_usage);
103 if (lstat(path, &st))
105 die("'%s': %s", path, strerror(errno));
106 if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
107 die("'%s': not a regular file or symlink", path);
108 stuff_change(&revs->diffopt,
109 canon_mode(st.st_mode), canon_mode(st.st_mode),
110 blob[0].sha1, null_sha1,
111 path, path);
112 diffcore_std(&revs->diffopt);
113 diff_flush(&revs->diffopt);
114 return 0;
115}
116static int builtin_diff_blobs(struct rev_info *revs,
118 int argc, const char **argv,
119 struct blobinfo *blob)
120{
121 /* Blobs: the arguments are reversed when setup_revisions()
122 * picked them up.
123 */
124 unsigned mode = canon_mode(S_IFREG | 0644);
125 if (argc > 1)
127 usage(builtin_diff_usage);
128 stuff_change(&revs->diffopt,
130 mode, mode,
131 blob[1].sha1, blob[0].sha1,
132 blob[0].name, blob[0].name);
133 diffcore_std(&revs->diffopt);
134 diff_flush(&revs->diffopt);
135 return 0;
136}
137static int builtin_diff_index(struct rev_info *revs,
139 int argc, const char **argv)
140{
141 int cached = 0;
142 while (1 < argc) {
143 const char *arg = argv[1];
144 if (!strcmp(arg, "--cached"))
145 cached = 1;
146 else
147 usage(builtin_diff_usage);
148 argv++; argc--;
149 }
150 /*
151 * Make sure there is one revision (i.e. pending object),
152 * and there is no revision filtering parameters.
153 */
154 if (revs->pending.nr != 1 ||
155 revs->max_count != -1 || revs->min_age != -1 ||
156 revs->max_age != -1)
157 usage(builtin_diff_usage);
158 return run_diff_index(revs, cached);
159}
160static int builtin_diff_tree(struct rev_info *revs,
162 int argc, const char **argv,
163 struct object_array_entry *ent)
164{
165 const unsigned char *(sha1[2]);
166 int swap = 0;
167 if (argc > 1)
169 usage(builtin_diff_usage);
170 /* We saw two trees, ent[0] and ent[1].
172 * if ent[1] is unintesting, they are swapped
173 */
174 if (ent[1].item->flags & UNINTERESTING)
175 swap = 1;
176 sha1[swap] = ent[0].item->sha1;
177 sha1[1-swap] = ent[1].item->sha1;
178 diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
179 log_tree_diff_flush(revs);
180 return 0;
181}
182static int builtin_diff_combined(struct rev_info *revs,
184 int argc, const char **argv,
185 struct object_array_entry *ent,
186 int ents)
187{
188 const unsigned char (*parent)[20];
189 int i;
190 if (argc > 1)
192 usage(builtin_diff_usage);
193 if (!revs->dense_combined_merges && !revs->combine_merges)
195 revs->dense_combined_merges = revs->combine_merges = 1;
196 parent = xmalloc(ents * sizeof(*parent));
197 /* Again, the revs are all reverse */
198 for (i = 0; i < ents; i++)
199 memcpy(parent + i, ent[ents - 1 - i].item->sha1, 20);
200 diff_tree_combined(parent[0], parent + 1, ents - 1,
201 revs->dense_combined_merges, revs);
202 return 0;
203}
204void add_head(struct rev_info *revs)
206{
207 unsigned char sha1[20];
208 struct object *obj;
209 if (get_sha1("HEAD", sha1))
210 return;
211 obj = parse_object(sha1);
212 if (!obj)
213 return;
214 add_pending_object(revs, obj, "HEAD");
215}
216int cmd_diff(int argc, const char **argv, char **envp)
218{
219 int i;
220 struct rev_info rev;
221 struct object_array_entry ent[100];
222 int ents = 0, blobs = 0, paths = 0;
223 const char *path = NULL;
224 struct blobinfo blob[2];
225 /*
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 */
245 git_config(git_diff_config);
247 init_revisions(&rev);
248 argc = setup_revisions(argc, argv, &rev, NULL);
250 if (!rev.diffopt.output_format) {
251 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
252 diff_setup_done(&rev.diffopt);
253 }
254 /* Do we have --cached and not have a pending object, then
256 * default to HEAD by hand. Eek.
257 */
258 if (!rev.pending.nr) {
259 int i;
260 for (i = 1; i < argc; i++) {
261 const char *arg = argv[i];
262 if (!strcmp(arg, "--"))
263 break;
264 else if (!strcmp(arg, "--cached")) {
265 add_head(&rev);
266 break;
267 }
268 }
269 }
270 for (i = 0; i < rev.pending.nr; i++) {
272 struct object_array_entry *list = rev.pending.objects+i;
273 struct object *obj = list->item;
274 const char *name = list->name;
275 int flags = (obj->flags & UNINTERESTING);
276 if (!obj->parsed)
277 obj = parse_object(obj->sha1);
278 obj = deref_tag(obj, NULL, 0);
279 if (!obj)
280 die("invalid object '%s' given.", name);
281 if (obj->type == TYPE_COMMIT)
282 obj = &((struct commit *)obj)->tree->object;
283 if (obj->type == TYPE_TREE) {
284 if (ARRAY_SIZE(ent) <= ents)
285 die("more than %d trees given: '%s'",
286 (int) ARRAY_SIZE(ent), name);
287 obj->flags |= flags;
288 ent[ents].item = obj;
289 ent[ents].name = name;
290 ents++;
291 continue;
292 }
293 if (obj->type == TYPE_BLOB) {
294 if (2 <= blobs)
295 die("more than two blobs given: '%s'", name);
296 memcpy(blob[blobs].sha1, obj->sha1, 20);
297 blob[blobs].name = name;
298 blobs++;
299 continue;
300 }
302 die("unhandled object '%s' given.", name);
303 }
304 if (rev.prune_data) {
305 const char **pathspec = rev.prune_data;
306 while (*pathspec) {
307 if (!path)
308 path = *pathspec;
309 paths++;
310 pathspec++;
311 }
312 }
313 /*
315 * Now, do the arguments look reasonable?
316 */
317 if (!ents) {
318 switch (blobs) {
319 case 0:
320 return builtin_diff_files(&rev, argc, argv);
321 break;
322 case 1:
323 if (paths != 1)
324 usage(builtin_diff_usage);
325 return builtin_diff_b_f(&rev, argc, argv, blob, path);
326 break;
327 case 2:
328 if (paths)
329 usage(builtin_diff_usage);
330 return builtin_diff_blobs(&rev, argc, argv, blob);
331 break;
332 default:
333 usage(builtin_diff_usage);
334 }
335 }
336 else if (blobs)
337 usage(builtin_diff_usage);
338 else if (ents == 1)
339 return builtin_diff_index(&rev, argc, argv);
340 else if (ents == 2)
341 return builtin_diff_tree(&rev, argc, argv, ent);
342 else
343 return builtin_diff_combined(&rev, argc, argv, ent, ents);
344 usage(builtin_diff_usage);
345}