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 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 (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
72 !hashcmp(old_sha1, new_sha1))
73 return;
74 if (opt->reverse_diff) {
76 unsigned tmp;
77 const unsigned char *tmp_u;
78 const char *tmp_c;
79 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
80 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
81 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
82 }
83 one = alloc_filespec(old_name);
84 two = alloc_filespec(new_name);
85 fill_filespec(one, old_sha1, old_mode);
86 fill_filespec(two, new_sha1, new_mode);
87 /* NEEDSWORK: shouldn't this part of diffopt??? */
89 diff_queue(&diff_queued_diff, one, two);
90}
91static int builtin_diff_b_f(struct rev_info *revs,
93 int argc, const char **argv,
94 struct blobinfo *blob,
95 const char *path)
96{
97 /* Blob vs file in the working tree*/
98 struct stat st;
99 if (argc > 1)
101 usage(builtin_diff_usage);
102 if (lstat(path, &st))
104 die("'%s': %s", path, strerror(errno));
105 if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
106 die("'%s': not a regular file or symlink", path);
107 stuff_change(&revs->diffopt,
108 canon_mode(st.st_mode), canon_mode(st.st_mode),
109 blob[0].sha1, null_sha1,
110 path, path);
111 diffcore_std(&revs->diffopt);
112 diff_flush(&revs->diffopt);
113 return 0;
114}
115static int builtin_diff_blobs(struct rev_info *revs,
117 int argc, const char **argv,
118 struct blobinfo *blob)
119{
120 unsigned mode = canon_mode(S_IFREG | 0644);
121 if (argc > 1)
123 usage(builtin_diff_usage);
124 stuff_change(&revs->diffopt,
126 mode, mode,
127 blob[0].sha1, blob[1].sha1,
128 blob[0].name, blob[1].name);
129 diffcore_std(&revs->diffopt);
130 diff_flush(&revs->diffopt);
131 return 0;
132}
133static int builtin_diff_index(struct rev_info *revs,
135 int argc, const char **argv)
136{
137 int cached = 0;
138 while (1 < argc) {
139 const char *arg = argv[1];
140 if (!strcmp(arg, "--cached"))
141 cached = 1;
142 else
143 usage(builtin_diff_usage);
144 argv++; argc--;
145 }
146 /*
147 * Make sure there is one revision (i.e. pending object),
148 * and there is no revision filtering parameters.
149 */
150 if (revs->pending.nr != 1 ||
151 revs->max_count != -1 || revs->min_age != -1 ||
152 revs->max_age != -1)
153 usage(builtin_diff_usage);
154 return run_diff_index(revs, cached);
155}
156static int builtin_diff_tree(struct rev_info *revs,
158 int argc, const char **argv,
159 struct object_array_entry *ent)
160{
161 const unsigned char *(sha1[2]);
162 int swap = 0;
163 if (argc > 1)
165 usage(builtin_diff_usage);
166 /* We saw two trees, ent[0] and ent[1].
168 * if ent[1] is uninteresting, they are swapped
169 */
170 if (ent[1].item->flags & UNINTERESTING)
171 swap = 1;
172 sha1[swap] = ent[0].item->sha1;
173 sha1[1-swap] = ent[1].item->sha1;
174 diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
175 log_tree_diff_flush(revs);
176 return 0;
177}
178static int builtin_diff_combined(struct rev_info *revs,
180 int argc, const char **argv,
181 struct object_array_entry *ent,
182 int ents)
183{
184 const unsigned char (*parent)[20];
185 int i;
186 if (argc > 1)
188 usage(builtin_diff_usage);
189 if (!revs->dense_combined_merges && !revs->combine_merges)
191 revs->dense_combined_merges = revs->combine_merges = 1;
192 parent = xmalloc(ents * sizeof(*parent));
193 /* Again, the revs are all reverse */
194 for (i = 0; i < ents; i++)
195 hashcpy((unsigned char *)(parent + i),
196 ent[ents - 1 - i].item->sha1);
197 diff_tree_combined(parent[0], parent + 1, ents - 1,
198 revs->dense_combined_merges, revs);
199 return 0;
200}
201void add_head(struct rev_info *revs)
203{
204 unsigned char sha1[20];
205 struct object *obj;
206 if (get_sha1("HEAD", sha1))
207 return;
208 obj = parse_object(sha1);
209 if (!obj)
210 return;
211 add_pending_object(revs, obj, "HEAD");
212}
213int cmd_diff(int argc, const char **argv, const char *prefix)
215{
216 int i;
217 struct rev_info rev;
218 struct object_array_entry ent[100];
219 int ents = 0, blobs = 0, paths = 0;
220 const char *path = NULL;
221 struct blobinfo blob[2];
222 /*
224 * We could get N tree-ish in the rev.pending_objects list.
225 * Also there could be M blobs there, and P pathspecs.
226 *
227 * N=0, M=0:
228 * cache vs files (diff-files)
229 * N=0, M=2:
230 * compare two random blobs. P must be zero.
231 * N=0, M=1, P=1:
232 * compare a blob with a working tree file.
233 *
234 * N=1, M=0:
235 * tree vs cache (diff-index --cached)
236 *
237 * N=2, M=0:
238 * tree vs tree (diff-tree)
239 *
240 * Other cases are errors.
241 */
242 git_config(git_diff_ui_config);
244 init_revisions(&rev, prefix);
245 argc = setup_revisions(argc, argv, &rev, NULL);
247 if (!rev.diffopt.output_format) {
248 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
249 if (diff_setup_done(&rev.diffopt) < 0)
250 die("diff_setup_done failed");
251 }
252 /* Do we have --cached and not have a pending object, then
254 * default to HEAD by hand. Eek.
255 */
256 if (!rev.pending.nr) {
257 int i;
258 for (i = 1; i < argc; i++) {
259 const char *arg = argv[i];
260 if (!strcmp(arg, "--"))
261 break;
262 else if (!strcmp(arg, "--cached")) {
263 add_head(&rev);
264 if (!rev.pending.nr)
265 die("No HEAD commit to compare with (yet)");
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 == OBJ_COMMIT)
282 obj = &((struct commit *)obj)->tree->object;
283 if (obj->type == OBJ_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 == OBJ_BLOB) {
294 if (2 <= blobs)
295 die("more than two blobs given: '%s'", name);
296 hashcpy(blob[blobs].sha1, obj->sha1);
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 if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
343 /* diff A...B where there is one sane merge base between
344 * A and B. We have ent[0] == merge-base, ent[1] == A,
345 * and ent[2] == B. Show diff between the base and B.
346 */
347 ent[1] = ent[2];
348 return builtin_diff_tree(&rev, argc, argv, ent);
349 }
350 else
351 return builtin_diff_combined(&rev, argc, argv,
352 ent, ents);
353 usage(builtin_diff_usage);
354}