tree_entry_interesting(): support depth limit
[git/git.git] / tree-diff.c
1 /*
2 * Helper functions for tree diff generation
3 */
4 #include "cache.h"
5 #include "diff.h"
6 #include "diffcore.h"
7 #include "tree.h"
8
9 static void show_entry(struct diff_options *opt, const char *prefix,
10 struct tree_desc *desc, struct strbuf *base);
11
12 static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
13 struct strbuf *base, struct diff_options *opt)
14 {
15 unsigned mode1, mode2;
16 const char *path1, *path2;
17 const unsigned char *sha1, *sha2;
18 int cmp, pathlen1, pathlen2;
19 int old_baselen = base->len;
20 int retval = 0;
21
22 sha1 = tree_entry_extract(t1, &path1, &mode1);
23 sha2 = tree_entry_extract(t2, &path2, &mode2);
24
25 pathlen1 = tree_entry_len(path1, sha1);
26 pathlen2 = tree_entry_len(path2, sha2);
27 cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
28 if (cmp < 0) {
29 show_entry(opt, "-", t1, base);
30 return -1;
31 }
32 if (cmp > 0) {
33 show_entry(opt, "+", t2, base);
34 return 1;
35 }
36 if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
37 return 0;
38
39 /*
40 * If the filemode has changed to/from a directory from/to a regular
41 * file, we need to consider it a remove and an add.
42 */
43 if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
44 show_entry(opt, "-", t1, base);
45 show_entry(opt, "+", t2, base);
46 return 0;
47 }
48
49 strbuf_add(base, path1, pathlen1);
50 if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
51 if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
52 opt->change(opt, mode1, mode2,
53 sha1, sha2, base->buf, 0, 0);
54 }
55 strbuf_addch(base, '/');
56 retval = diff_tree_sha1(sha1, sha2, base->buf, opt);
57 } else {
58 opt->change(opt, mode1, mode2, sha1, sha2, base->buf, 0, 0);
59 }
60 strbuf_setlen(base, old_baselen);
61 return 0;
62 }
63
64 /* A whole sub-tree went away or appeared */
65 static void show_tree(struct diff_options *opt, const char *prefix,
66 struct tree_desc *desc, struct strbuf *base)
67 {
68 int all_interesting = 0;
69 while (desc->size) {
70 int show;
71
72 if (all_interesting)
73 show = 1;
74 else {
75 show = tree_entry_interesting(&desc->entry, base,
76 &opt->pathspec);
77 if (show == 2)
78 all_interesting = 1;
79 }
80 if (show < 0)
81 break;
82 if (show)
83 show_entry(opt, prefix, desc, base);
84 update_tree_entry(desc);
85 }
86 }
87
88 /* A file entry went away or appeared */
89 static void show_entry(struct diff_options *opt, const char *prefix,
90 struct tree_desc *desc, struct strbuf *base)
91 {
92 unsigned mode;
93 const char *path;
94 const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
95 int pathlen = tree_entry_len(path, sha1);
96 int old_baselen = base->len;
97
98 strbuf_add(base, path, pathlen);
99 if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
100 enum object_type type;
101 struct tree_desc inner;
102 void *tree;
103 unsigned long size;
104
105 tree = read_sha1_file(sha1, &type, &size);
106 if (!tree || type != OBJ_TREE)
107 die("corrupt tree sha %s", sha1_to_hex(sha1));
108
109 if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
110 opt->add_remove(opt, *prefix, mode, sha1, base->buf, 0);
111
112 strbuf_addch(base, '/');
113
114 init_tree_desc(&inner, tree, size);
115 show_tree(opt, prefix, &inner, base);
116 free(tree);
117 } else
118 opt->add_remove(opt, prefix[0], mode, sha1, base->buf, 0);
119
120 strbuf_setlen(base, old_baselen);
121 }
122
123 static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
124 struct diff_options *opt, int *all_interesting)
125 {
126 while (t->size) {
127 int show = tree_entry_interesting(&t->entry, base, &opt->pathspec);
128 if (show == 2)
129 *all_interesting = 1;
130 if (!show) {
131 update_tree_entry(t);
132 continue;
133 }
134 /* Skip it all? */
135 if (show < 0)
136 t->size = 0;
137 return;
138 }
139 }
140
141 int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
142 const char *base_str, struct diff_options *opt)
143 {
144 struct strbuf base;
145 int baselen = strlen(base_str);
146 int all_t1_interesting = 0;
147 int all_t2_interesting = 0;
148
149 /* Enable recursion indefinitely */
150 opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
151 opt->pathspec.max_depth = -1;
152
153 strbuf_init(&base, PATH_MAX);
154 strbuf_add(&base, base_str, baselen);
155
156 for (;;) {
157 if (DIFF_OPT_TST(opt, QUICK) &&
158 DIFF_OPT_TST(opt, HAS_CHANGES))
159 break;
160 if (opt->pathspec.nr) {
161 if (!all_t1_interesting)
162 skip_uninteresting(t1, &base, opt, &all_t1_interesting);
163 if (!all_t2_interesting)
164 skip_uninteresting(t2, &base, opt, &all_t2_interesting);
165 }
166 if (!t1->size) {
167 if (!t2->size)
168 break;
169 show_entry(opt, "+", t2, &base);
170 update_tree_entry(t2);
171 continue;
172 }
173 if (!t2->size) {
174 show_entry(opt, "-", t1, &base);
175 update_tree_entry(t1);
176 continue;
177 }
178 switch (compare_tree_entry(t1, t2, &base, opt)) {
179 case -1:
180 update_tree_entry(t1);
181 continue;
182 case 0:
183 update_tree_entry(t1);
184 /* Fallthrough */
185 case 1:
186 update_tree_entry(t2);
187 continue;
188 }
189 die("git diff-tree: internal error");
190 }
191
192 strbuf_release(&base);
193 return 0;
194 }
195
196 /*
197 * Does it look like the resulting diff might be due to a rename?
198 * - single entry
199 * - not a valid previous file
200 */
201 static inline int diff_might_be_rename(void)
202 {
203 return diff_queued_diff.nr == 1 &&
204 !DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
205 }
206
207 static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
208 {
209 struct diff_options diff_opts;
210 struct diff_queue_struct *q = &diff_queued_diff;
211 struct diff_filepair *choice;
212 const char *paths[1];
213 int i;
214
215 /* Remove the file creation entry from the diff queue, and remember it */
216 choice = q->queue[0];
217 q->nr = 0;
218
219 diff_setup(&diff_opts);
220 DIFF_OPT_SET(&diff_opts, RECURSIVE);
221 DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
222 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
223 diff_opts.single_follow = opt->pathspec.raw[0];
224 diff_opts.break_opt = opt->break_opt;
225 paths[0] = NULL;
226 diff_tree_setup_paths(paths, &diff_opts);
227 if (diff_setup_done(&diff_opts) < 0)
228 die("unable to set up diff options to follow renames");
229 diff_tree(t1, t2, base, &diff_opts);
230 diffcore_std(&diff_opts);
231 diff_tree_release_paths(&diff_opts);
232
233 /* Go through the new set of filepairing, and see if we find a more interesting one */
234 opt->found_follow = 0;
235 for (i = 0; i < q->nr; i++) {
236 struct diff_filepair *p = q->queue[i];
237
238 /*
239 * Found a source? Not only do we use that for the new
240 * diff_queued_diff, we will also use that as the path in
241 * the future!
242 */
243 if ((p->status == 'R' || p->status == 'C') &&
244 !strcmp(p->two->path, opt->pathspec.raw[0])) {
245 /* Switch the file-pairs around */
246 q->queue[i] = choice;
247 choice = p;
248
249 /* Update the path we use from now on.. */
250 diff_tree_release_paths(opt);
251 opt->pathspec.raw[0] = xstrdup(p->one->path);
252 diff_tree_setup_paths(opt->pathspec.raw, opt);
253
254 /*
255 * The caller expects us to return a set of vanilla
256 * filepairs to let a later call to diffcore_std()
257 * it makes to sort the renames out (among other
258 * things), but we already have found renames
259 * ourselves; signal diffcore_std() not to muck with
260 * rename information.
261 */
262 opt->found_follow = 1;
263 break;
264 }
265 }
266
267 /*
268 * Then, discard all the non-relevant file pairs...
269 */
270 for (i = 0; i < q->nr; i++) {
271 struct diff_filepair *p = q->queue[i];
272 diff_free_filepair(p);
273 }
274
275 /*
276 * .. and re-instate the one we want (which might be either the
277 * original one, or the rename/copy we found)
278 */
279 q->queue[0] = choice;
280 q->nr = 1;
281 }
282
283 int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
284 {
285 void *tree1, *tree2;
286 struct tree_desc t1, t2;
287 unsigned long size1, size2;
288 int retval;
289
290 tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
291 if (!tree1)
292 die("unable to read source tree (%s)", sha1_to_hex(old));
293 tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
294 if (!tree2)
295 die("unable to read destination tree (%s)", sha1_to_hex(new));
296 init_tree_desc(&t1, tree1, size1);
297 init_tree_desc(&t2, tree2, size2);
298 retval = diff_tree(&t1, &t2, base, opt);
299 if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
300 init_tree_desc(&t1, tree1, size1);
301 init_tree_desc(&t2, tree2, size2);
302 try_to_follow_renames(&t1, &t2, base, opt);
303 }
304 free(tree1);
305 free(tree2);
306 return retval;
307 }
308
309 int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
310 {
311 int retval;
312 void *tree;
313 unsigned long size;
314 struct tree_desc empty, real;
315
316 tree = read_object_with_reference(new, tree_type, &size, NULL);
317 if (!tree)
318 die("unable to read root tree (%s)", sha1_to_hex(new));
319 init_tree_desc(&real, tree, size);
320
321 init_tree_desc(&empty, "", 0);
322 retval = diff_tree(&empty, &real, base, opt);
323 free(tree);
324 return retval;
325 }
326
327 void diff_tree_release_paths(struct diff_options *opt)
328 {
329 free_pathspec(&opt->pathspec);
330 }
331
332 void diff_tree_setup_paths(const char **p, struct diff_options *opt)
333 {
334 init_pathspec(&opt->pathspec, p);
335 }