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"git-diff <options> <rev>{0,2} -- <path>*";
27static 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 const char *old_name,
33 const char *new_name)
34{
35 struct diff_filespec *one, *two;
36 if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
38 !hashcmp(old_sha1, new_sha1))
39 return;
40 if (opt->reverse_diff) {
42 unsigned tmp;
43 const unsigned char *tmp_u;
44 const char *tmp_c;
45 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
46 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
47 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
48 }
49 one = alloc_filespec(old_name);
50 two = alloc_filespec(new_name);
51 fill_filespec(one, old_sha1, old_mode);
52 fill_filespec(two, new_sha1, new_mode);
53 /* NEEDSWORK: shouldn't this part of diffopt??? */
55 diff_queue(&diff_queued_diff, one, two);
56}
57static int builtin_diff_b_f(struct rev_info *revs,
59 int argc, const char **argv,
60 struct blobinfo *blob,
61 const char *path)
62{
63 /* Blob vs file in the working tree*/
64 struct stat st;
65 if (argc > 1)
67 usage(builtin_diff_usage);
68 if (lstat(path, &st))
70 die("'%s': %s", path, strerror(errno));
71 if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
72 die("'%s': not a regular file or symlink", path);
73 stuff_change(&revs->diffopt,
74 canon_mode(st.st_mode), canon_mode(st.st_mode),
75 blob[0].sha1, null_sha1,
76 path, path);
77 diffcore_std(&revs->diffopt);
78 diff_flush(&revs->diffopt);
79 return 0;
80}
81static int builtin_diff_blobs(struct rev_info *revs,
83 int argc, const char **argv,
84 struct blobinfo *blob)
85{
86 unsigned mode = canon_mode(S_IFREG | 0644);
87 if (argc > 1)
89 usage(builtin_diff_usage);
90 stuff_change(&revs->diffopt,
92 mode, mode,
93 blob[0].sha1, blob[1].sha1,
94 blob[0].name, blob[1].name);
95 diffcore_std(&revs->diffopt);
96 diff_flush(&revs->diffopt);
97 return 0;
98}
99static int builtin_diff_index(struct rev_info *revs,
101 int argc, const char **argv)
102{
103 int cached = 0;
104 while (1 < argc) {
105 const char *arg = argv[1];
106 if (!strcmp(arg, "--cached"))
107 cached = 1;
108 else
109 usage(builtin_diff_usage);
110 argv++; argc--;
111 }
112 /*
113 * Make sure there is one revision (i.e. pending object),
114 * and there is no revision filtering parameters.
115 */
116 if (revs->pending.nr != 1 ||
117 revs->max_count != -1 || revs->min_age != -1 ||
118 revs->max_age != -1)
119 usage(builtin_diff_usage);
120 if (read_cache() < 0) {
121 perror("read_cache");
122 return -1;
123 }
124 return run_diff_index(revs, cached);
125}
126static int builtin_diff_tree(struct rev_info *revs,
128 int argc, const char **argv,
129 struct object_array_entry *ent)
130{
131 const unsigned char *(sha1[2]);
132 int swap = 0;
133 if (argc > 1)
135 usage(builtin_diff_usage);
136 /* We saw two trees, ent[0] and ent[1].
138 * if ent[1] is uninteresting, they are swapped
139 */
140 if (ent[1].item->flags & UNINTERESTING)
141 swap = 1;
142 sha1[swap] = ent[0].item->sha1;
143 sha1[1-swap] = ent[1].item->sha1;
144 diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
145 log_tree_diff_flush(revs);
146 return 0;
147}
148static int builtin_diff_combined(struct rev_info *revs,
150 int argc, const char **argv,
151 struct object_array_entry *ent,
152 int ents)
153{
154 const unsigned char (*parent)[20];
155 int i;
156 if (argc > 1)
158 usage(builtin_diff_usage);
159 if (!revs->dense_combined_merges && !revs->combine_merges)
161 revs->dense_combined_merges = revs->combine_merges = 1;
162 parent = xmalloc(ents * sizeof(*parent));
163 /* Again, the revs are all reverse */
164 for (i = 0; i < ents; i++)
165 hashcpy((unsigned char*)parent + i, ent[ents - 1 - i].item->sha1);
166 diff_tree_combined(parent[0], parent + 1, ents - 1,
167 revs->dense_combined_merges, revs);
168 return 0;
169}
170void add_head(struct rev_info *revs)
172{
173 unsigned char sha1[20];
174 struct object *obj;
175 if (get_sha1("HEAD", sha1))
176 return;
177 obj = parse_object(sha1);
178 if (!obj)
179 return;
180 add_pending_object(revs, obj, "HEAD");
181}
182int cmd_diff(int argc, const char **argv, const char *prefix)
184{
185 int i;
186 struct rev_info rev;
187 struct object_array_entry ent[100];
188 int ents = 0, blobs = 0, paths = 0;
189 const char *path = NULL;
190 struct blobinfo blob[2];
191 int nongit = 0;
192 /*
194 * We could get N tree-ish in the rev.pending_objects list.
195 * Also there could be M blobs there, and P pathspecs.
196 *
197 * N=0, M=0:
198 * cache vs files (diff-files)
199 * N=0, M=2:
200 * compare two random blobs. P must be zero.
201 * N=0, M=1, P=1:
202 * compare a blob with a working tree file.
203 *
204 * N=1, M=0:
205 * tree vs cache (diff-index --cached)
206 *
207 * N=2, M=0:
208 * tree vs tree (diff-tree)
209 *
210 * Other cases are errors.
211 */
212 prefix = setup_git_directory_gently(&nongit);
214 git_config(git_diff_ui_config);
215 init_revisions(&rev, prefix);
216 argc = setup_revisions(argc, argv, &rev, NULL);
218 if (!rev.diffopt.output_format) {
219 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
220 if (diff_setup_done(&rev.diffopt) < 0)
221 die("diff_setup_done failed");
222 }
223 /* Do we have --cached and not have a pending object, then
225 * default to HEAD by hand. Eek.
226 */
227 if (!rev.pending.nr) {
228 int i;
229 for (i = 1; i < argc; i++) {
230 const char *arg = argv[i];
231 if (!strcmp(arg, "--"))
232 break;
233 else if (!strcmp(arg, "--cached")) {
234 add_head(&rev);
235 break;
236 }
237 }
238 }
239 for (i = 0; i < rev.pending.nr; i++) {
241 struct object_array_entry *list = rev.pending.objects+i;
242 struct object *obj = list->item;
243 const char *name = list->name;
244 int flags = (obj->flags & UNINTERESTING);
245 if (!obj->parsed)
246 obj = parse_object(obj->sha1);
247 obj = deref_tag(obj, NULL, 0);
248 if (!obj)
249 die("invalid object '%s' given.", name);
250 if (obj->type == OBJ_COMMIT)
251 obj = &((struct commit *)obj)->tree->object;
252 if (obj->type == OBJ_TREE) {
253 if (ARRAY_SIZE(ent) <= ents)
254 die("more than %d trees given: '%s'",
255 (int) ARRAY_SIZE(ent), name);
256 obj->flags |= flags;
257 ent[ents].item = obj;
258 ent[ents].name = name;
259 ents++;
260 continue;
261 }
262 if (obj->type == OBJ_BLOB) {
263 if (2 <= blobs)
264 die("more than two blobs given: '%s'", name);
265 hashcpy(blob[blobs].sha1, obj->sha1);
266 blob[blobs].name = name;
267 blobs++;
268 continue;
269 }
271 die("unhandled object '%s' given.", name);
272 }
273 if (rev.prune_data) {
274 const char **pathspec = rev.prune_data;
275 while (*pathspec) {
276 if (!path)
277 path = *pathspec;
278 paths++;
279 pathspec++;
280 }
281 }
282 /*
284 * Now, do the arguments look reasonable?
285 */
286 if (!ents) {
287 switch (blobs) {
288 case 0:
289 return run_diff_files_cmd(&rev, argc, argv);
290 break;
291 case 1:
292 if (paths != 1)
293 usage(builtin_diff_usage);
294 return builtin_diff_b_f(&rev, argc, argv, blob, path);
295 break;
296 case 2:
297 if (paths)
298 usage(builtin_diff_usage);
299 return builtin_diff_blobs(&rev, argc, argv, blob);
300 break;
301 default:
302 usage(builtin_diff_usage);
303 }
304 }
305 else if (blobs)
306 usage(builtin_diff_usage);
307 else if (ents == 1)
308 return builtin_diff_index(&rev, argc, argv);
309 else if (ents == 2)
310 return builtin_diff_tree(&rev, argc, argv, ent);
311 else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
312 /* diff A...B where there is one sane merge base between
313 * A and B. We have ent[0] == merge-base, ent[1] == A,
314 * and ent[2] == B. Show diff between the base and B.
315 */
316 ent[1] = ent[2];
317 return builtin_diff_tree(&rev, argc, argv, ent);
318 }
319 else
320 return builtin_diff_combined(&rev, argc, argv,
321 ent, ents);
322 usage(builtin_diff_usage);
323}