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),
166 ent[ents - 1 - i].item->sha1);
167 diff_tree_combined(parent[0], parent + 1, ents - 1,
168 revs->dense_combined_merges, revs);
169 return 0;
170}
171void add_head(struct rev_info *revs)
173{
174 unsigned char sha1[20];
175 struct object *obj;
176 if (get_sha1("HEAD", sha1))
177 return;
178 obj = parse_object(sha1);
179 if (!obj)
180 return;
181 add_pending_object(revs, obj, "HEAD");
182}
183int cmd_diff(int argc, const char **argv, const char *prefix)
185{
186 int i;
187 struct rev_info rev;
188 struct object_array_entry ent[100];
189 int ents = 0, blobs = 0, paths = 0;
190 const char *path = NULL;
191 struct blobinfo blob[2];
192 int nongit = 0;
193 int result = 0;
194 /*
196 * We could get N tree-ish in the rev.pending_objects list.
197 * Also there could be M blobs there, and P pathspecs.
198 *
199 * N=0, M=0:
200 * cache vs files (diff-files)
201 * N=0, M=2:
202 * compare two random blobs. P must be zero.
203 * N=0, M=1, P=1:
204 * compare a blob with a working tree file.
205 *
206 * N=1, M=0:
207 * tree vs cache (diff-index --cached)
208 *
209 * N=2, M=0:
210 * tree vs tree (diff-tree)
211 *
212 * Other cases are errors.
213 */
214 prefix = setup_git_directory_gently(&nongit);
216 git_config(git_diff_ui_config);
217 init_revisions(&rev, prefix);
218 if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
220 argc = 0;
221 else
222 argc = setup_revisions(argc, argv, &rev, NULL);
223 if (!rev.diffopt.output_format) {
224 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
225 if (diff_setup_done(&rev.diffopt) < 0)
226 die("diff_setup_done failed");
227 }
228 /* Do we have --cached and not have a pending object, then
230 * default to HEAD by hand. Eek.
231 */
232 if (!rev.pending.nr) {
233 int i;
234 for (i = 1; i < argc; i++) {
235 const char *arg = argv[i];
236 if (!strcmp(arg, "--"))
237 break;
238 else if (!strcmp(arg, "--cached")) {
239 add_head(&rev);
240 if (!rev.pending.nr)
241 die("No HEAD commit to compare with (yet)");
242 break;
243 }
244 }
245 }
246 for (i = 0; i < rev.pending.nr; i++) {
248 struct object_array_entry *list = rev.pending.objects+i;
249 struct object *obj = list->item;
250 const char *name = list->name;
251 int flags = (obj->flags & UNINTERESTING);
252 if (!obj->parsed)
253 obj = parse_object(obj->sha1);
254 obj = deref_tag(obj, NULL, 0);
255 if (!obj)
256 die("invalid object '%s' given.", name);
257 if (obj->type == OBJ_COMMIT)
258 obj = &((struct commit *)obj)->tree->object;
259 if (obj->type == OBJ_TREE) {
260 if (ARRAY_SIZE(ent) <= ents)
261 die("more than %d trees given: '%s'",
262 (int) ARRAY_SIZE(ent), name);
263 obj->flags |= flags;
264 ent[ents].item = obj;
265 ent[ents].name = name;
266 ents++;
267 continue;
268 }
269 if (obj->type == OBJ_BLOB) {
270 if (2 <= blobs)
271 die("more than two blobs given: '%s'", name);
272 hashcpy(blob[blobs].sha1, obj->sha1);
273 blob[blobs].name = name;
274 blobs++;
275 continue;
276 }
278 die("unhandled object '%s' given.", name);
279 }
280 if (rev.prune_data) {
281 const char **pathspec = rev.prune_data;
282 while (*pathspec) {
283 if (!path)
284 path = *pathspec;
285 paths++;
286 pathspec++;
287 }
288 }
289 /*
291 * Now, do the arguments look reasonable?
292 */
293 if (!ents) {
294 switch (blobs) {
295 case 0:
296 result = run_diff_files_cmd(&rev, argc, argv);
297 break;
298 case 1:
299 if (paths != 1)
300 usage(builtin_diff_usage);
301 result = builtin_diff_b_f(&rev, argc, argv, blob, path);
302 break;
303 case 2:
304 if (paths)
305 usage(builtin_diff_usage);
306 result = builtin_diff_blobs(&rev, argc, argv, blob);
307 break;
308 default:
309 usage(builtin_diff_usage);
310 }
311 }
312 else if (blobs)
313 usage(builtin_diff_usage);
314 else if (ents == 1)
315 result = builtin_diff_index(&rev, argc, argv);
316 else if (ents == 2)
317 result = builtin_diff_tree(&rev, argc, argv, ent);
318 else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
319 /* diff A...B where there is one sane merge base between
320 * A and B. We have ent[0] == merge-base, ent[1] == A,
321 * and ent[2] == B. Show diff between the base and B.
322 */
323 ent[1] = ent[2];
324 result = builtin_diff_tree(&rev, argc, argv, ent);
325 }
326 else
327 result = builtin_diff_combined(&rev, argc, argv,
328 ent, ents);
329 if (rev.diffopt.exit_with_status)
330 result = rev.diffopt.has_changes;
331 return result;
332}