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Commit | Line | Data |
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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 char *malloc_base(const char *base, int baselen, const char *path, int pathlen) | |
10 | { | |
11 | char *newbase = xmalloc(baselen + pathlen + 2); | |
12 | memcpy(newbase, base, baselen); | |
13 | memcpy(newbase + baselen, path, pathlen); | |
14 | memcpy(newbase + baselen + pathlen, "/", 2); | |
15 | return newbase; | |
16 | } | |
17 | ||
18 | static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc, | |
19 | const char *base, int baselen); | |
20 | ||
21 | static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt) | |
22 | { | |
23 | unsigned mode1, mode2; | |
24 | const char *path1, *path2; | |
25 | const unsigned char *sha1, *sha2; | |
26 | int cmp, pathlen1, pathlen2; | |
27 | ||
28 | sha1 = tree_entry_extract(t1, &path1, &mode1); | |
29 | sha2 = tree_entry_extract(t2, &path2, &mode2); | |
30 | ||
31 | pathlen1 = tree_entry_len(path1, sha1); | |
32 | pathlen2 = tree_entry_len(path2, sha2); | |
33 | cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2); | |
34 | if (cmp < 0) { | |
35 | show_entry(opt, "-", t1, base, baselen); | |
36 | return -1; | |
37 | } | |
38 | if (cmp > 0) { | |
39 | show_entry(opt, "+", t2, base, baselen); | |
40 | return 1; | |
41 | } | |
42 | if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2) | |
43 | return 0; | |
44 | ||
45 | /* | |
46 | * If the filemode has changed to/from a directory from/to a regular | |
47 | * file, we need to consider it a remove and an add. | |
48 | */ | |
49 | if (S_ISDIR(mode1) != S_ISDIR(mode2)) { | |
50 | show_entry(opt, "-", t1, base, baselen); | |
51 | show_entry(opt, "+", t2, base, baselen); | |
52 | return 0; | |
53 | } | |
54 | ||
55 | if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) { | |
56 | int retval; | |
57 | char *newbase = malloc_base(base, baselen, path1, pathlen1); | |
58 | if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) | |
59 | opt->change(opt, mode1, mode2, | |
60 | sha1, sha2, base, path1); | |
61 | retval = diff_tree_sha1(sha1, sha2, newbase, opt); | |
62 | free(newbase); | |
63 | return retval; | |
64 | } | |
65 | ||
66 | opt->change(opt, mode1, mode2, sha1, sha2, base, path1); | |
67 | return 0; | |
68 | } | |
69 | ||
70 | /* | |
71 | * Is a tree entry interesting given the pathspec we have? | |
72 | * | |
73 | * Return: | |
74 | * - 2 for "yes, and all subsequent entries will be" | |
75 | * - 1 for yes | |
76 | * - zero for no | |
77 | * - negative for "no, and no subsequent entries will be either" | |
78 | */ | |
79 | static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt) | |
80 | { | |
81 | const char *path; | |
82 | const unsigned char *sha1; | |
83 | unsigned mode; | |
84 | int i; | |
85 | int pathlen; | |
86 | int never_interesting = -1; | |
87 | ||
88 | if (!opt->nr_paths) | |
89 | return 1; | |
90 | ||
91 | sha1 = tree_entry_extract(desc, &path, &mode); | |
92 | ||
93 | pathlen = tree_entry_len(path, sha1); | |
94 | ||
95 | for (i = 0; i < opt->nr_paths; i++) { | |
96 | const char *match = opt->paths[i]; | |
97 | int matchlen = opt->pathlens[i]; | |
98 | int m = -1; /* signals that we haven't called strncmp() */ | |
99 | ||
100 | if (baselen >= matchlen) { | |
101 | /* If it doesn't match, move along... */ | |
102 | if (strncmp(base, match, matchlen)) | |
103 | continue; | |
104 | ||
105 | /* | |
106 | * The base is a subdirectory of a path which | |
107 | * was specified, so all of them are interesting. | |
108 | */ | |
109 | return 2; | |
110 | } | |
111 | ||
112 | /* Does the base match? */ | |
113 | if (strncmp(base, match, baselen)) | |
114 | continue; | |
115 | ||
116 | match += baselen; | |
117 | matchlen -= baselen; | |
118 | ||
119 | if (never_interesting) { | |
120 | /* | |
121 | * We have not seen any match that sorts later | |
122 | * than the current path. | |
123 | */ | |
124 | ||
125 | /* | |
126 | * Does match sort strictly earlier than path | |
127 | * with their common parts? | |
128 | */ | |
129 | m = strncmp(match, path, | |
130 | (matchlen < pathlen) ? matchlen : pathlen); | |
131 | if (m < 0) | |
132 | continue; | |
133 | ||
134 | /* | |
135 | * If we come here even once, that means there is at | |
136 | * least one pathspec that would sort equal to or | |
137 | * later than the path we are currently looking at. | |
138 | * In other words, if we have never reached this point | |
139 | * after iterating all pathspecs, it means all | |
140 | * pathspecs are either outside of base, or inside the | |
141 | * base but sorts strictly earlier than the current | |
142 | * one. In either case, they will never match the | |
143 | * subsequent entries. In such a case, we initialized | |
144 | * the variable to -1 and that is what will be | |
145 | * returned, allowing the caller to terminate early. | |
146 | */ | |
147 | never_interesting = 0; | |
148 | } | |
149 | ||
150 | if (pathlen > matchlen) | |
151 | continue; | |
152 | ||
153 | if (matchlen > pathlen) { | |
154 | if (match[pathlen] != '/') | |
155 | continue; | |
156 | if (!S_ISDIR(mode)) | |
157 | continue; | |
158 | } | |
159 | ||
160 | if (m == -1) | |
161 | /* | |
162 | * we cheated and did not do strncmp(), so we do | |
163 | * that here. | |
164 | */ | |
165 | m = strncmp(match, path, pathlen); | |
166 | ||
167 | /* | |
168 | * If common part matched earlier then it is a hit, | |
169 | * because we rejected the case where path is not a | |
170 | * leading directory and is shorter than match. | |
171 | */ | |
172 | if (!m) | |
173 | return 1; | |
174 | } | |
175 | return never_interesting; /* No matches */ | |
176 | } | |
177 | ||
178 | /* A whole sub-tree went away or appeared */ | |
179 | static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen) | |
180 | { | |
181 | int all_interesting = 0; | |
182 | while (desc->size) { | |
183 | int show; | |
184 | ||
185 | if (all_interesting) | |
186 | show = 1; | |
187 | else { | |
188 | show = tree_entry_interesting(desc, base, baselen, | |
189 | opt); | |
190 | if (show == 2) | |
191 | all_interesting = 1; | |
192 | } | |
193 | if (show < 0) | |
194 | break; | |
195 | if (show) | |
196 | show_entry(opt, prefix, desc, base, baselen); | |
197 | update_tree_entry(desc); | |
198 | } | |
199 | } | |
200 | ||
201 | /* A file entry went away or appeared */ | |
202 | static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc, | |
203 | const char *base, int baselen) | |
204 | { | |
205 | unsigned mode; | |
206 | const char *path; | |
207 | const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode); | |
208 | ||
209 | if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) { | |
210 | enum object_type type; | |
211 | int pathlen = tree_entry_len(path, sha1); | |
212 | char *newbase = malloc_base(base, baselen, path, pathlen); | |
213 | struct tree_desc inner; | |
214 | void *tree; | |
215 | unsigned long size; | |
216 | ||
217 | tree = read_sha1_file(sha1, &type, &size); | |
218 | if (!tree || type != OBJ_TREE) | |
219 | die("corrupt tree sha %s", sha1_to_hex(sha1)); | |
220 | ||
221 | init_tree_desc(&inner, tree, size); | |
222 | show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen); | |
223 | ||
224 | free(tree); | |
225 | free(newbase); | |
226 | } else { | |
227 | opt->add_remove(opt, prefix[0], mode, sha1, base, path); | |
228 | } | |
229 | } | |
230 | ||
231 | static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt) | |
232 | { | |
233 | int all_interesting = 0; | |
234 | while (t->size) { | |
235 | int show; | |
236 | ||
237 | if (all_interesting) | |
238 | show = 1; | |
239 | else { | |
240 | show = tree_entry_interesting(t, base, baselen, opt); | |
241 | if (show == 2) | |
242 | all_interesting = 1; | |
243 | } | |
244 | if (!show) { | |
245 | update_tree_entry(t); | |
246 | continue; | |
247 | } | |
248 | /* Skip it all? */ | |
249 | if (show < 0) | |
250 | t->size = 0; | |
251 | return; | |
252 | } | |
253 | } | |
254 | ||
255 | int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt) | |
256 | { | |
257 | int baselen = strlen(base); | |
258 | ||
259 | for (;;) { | |
260 | if (DIFF_OPT_TST(opt, QUIET) && DIFF_OPT_TST(opt, HAS_CHANGES)) | |
261 | break; | |
262 | if (opt->nr_paths) { | |
263 | skip_uninteresting(t1, base, baselen, opt); | |
264 | skip_uninteresting(t2, base, baselen, opt); | |
265 | } | |
266 | if (!t1->size) { | |
267 | if (!t2->size) | |
268 | break; | |
269 | show_entry(opt, "+", t2, base, baselen); | |
270 | update_tree_entry(t2); | |
271 | continue; | |
272 | } | |
273 | if (!t2->size) { | |
274 | show_entry(opt, "-", t1, base, baselen); | |
275 | update_tree_entry(t1); | |
276 | continue; | |
277 | } | |
278 | switch (compare_tree_entry(t1, t2, base, baselen, opt)) { | |
279 | case -1: | |
280 | update_tree_entry(t1); | |
281 | continue; | |
282 | case 0: | |
283 | update_tree_entry(t1); | |
284 | /* Fallthrough */ | |
285 | case 1: | |
286 | update_tree_entry(t2); | |
287 | continue; | |
288 | } | |
289 | die("git-diff-tree: internal error"); | |
290 | } | |
291 | return 0; | |
292 | } | |
293 | ||
294 | /* | |
295 | * Does it look like the resulting diff might be due to a rename? | |
296 | * - single entry | |
297 | * - not a valid previous file | |
298 | */ | |
299 | static inline int diff_might_be_rename(void) | |
300 | { | |
301 | return diff_queued_diff.nr == 1 && | |
302 | !DIFF_FILE_VALID(diff_queued_diff.queue[0]->one); | |
303 | } | |
304 | ||
305 | static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt) | |
306 | { | |
307 | struct diff_options diff_opts; | |
308 | struct diff_queue_struct *q = &diff_queued_diff; | |
309 | struct diff_filepair *choice; | |
310 | const char *paths[1]; | |
311 | int i; | |
312 | ||
313 | /* Remove the file creation entry from the diff queue, and remember it */ | |
314 | choice = q->queue[0]; | |
315 | q->nr = 0; | |
316 | ||
317 | diff_setup(&diff_opts); | |
318 | DIFF_OPT_SET(&diff_opts, RECURSIVE); | |
319 | diff_opts.detect_rename = DIFF_DETECT_RENAME; | |
320 | diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; | |
321 | diff_opts.single_follow = opt->paths[0]; | |
322 | diff_opts.break_opt = opt->break_opt; | |
323 | paths[0] = NULL; | |
324 | diff_tree_setup_paths(paths, &diff_opts); | |
325 | if (diff_setup_done(&diff_opts) < 0) | |
326 | die("unable to set up diff options to follow renames"); | |
327 | diff_tree(t1, t2, base, &diff_opts); | |
328 | diffcore_std(&diff_opts); | |
329 | diff_tree_release_paths(&diff_opts); | |
330 | ||
331 | /* Go through the new set of filepairing, and see if we find a more interesting one */ | |
332 | for (i = 0; i < q->nr; i++) { | |
333 | struct diff_filepair *p = q->queue[i]; | |
334 | ||
335 | /* | |
336 | * Found a source? Not only do we use that for the new | |
337 | * diff_queued_diff, we will also use that as the path in | |
338 | * the future! | |
339 | */ | |
340 | if ((p->status == 'R' || p->status == 'C') && !strcmp(p->two->path, opt->paths[0])) { | |
341 | /* Switch the file-pairs around */ | |
342 | q->queue[i] = choice; | |
343 | choice = p; | |
344 | ||
345 | /* Update the path we use from now on.. */ | |
346 | diff_tree_release_paths(opt); | |
347 | opt->paths[0] = xstrdup(p->one->path); | |
348 | diff_tree_setup_paths(opt->paths, opt); | |
349 | break; | |
350 | } | |
351 | } | |
352 | ||
353 | /* | |
354 | * Then, discard all the non-relevane file pairs... | |
355 | */ | |
356 | for (i = 0; i < q->nr; i++) { | |
357 | struct diff_filepair *p = q->queue[i]; | |
358 | diff_free_filepair(p); | |
359 | } | |
360 | ||
361 | /* | |
362 | * .. and re-instate the one we want (which might be either the | |
363 | * original one, or the rename/copy we found) | |
364 | */ | |
365 | q->queue[0] = choice; | |
366 | q->nr = 1; | |
367 | } | |
368 | ||
369 | int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt) | |
370 | { | |
371 | void *tree1, *tree2; | |
372 | struct tree_desc t1, t2; | |
373 | unsigned long size1, size2; | |
374 | int retval; | |
375 | ||
376 | tree1 = read_object_with_reference(old, tree_type, &size1, NULL); | |
377 | if (!tree1) | |
378 | die("unable to read source tree (%s)", sha1_to_hex(old)); | |
379 | tree2 = read_object_with_reference(new, tree_type, &size2, NULL); | |
380 | if (!tree2) | |
381 | die("unable to read destination tree (%s)", sha1_to_hex(new)); | |
382 | init_tree_desc(&t1, tree1, size1); | |
383 | init_tree_desc(&t2, tree2, size2); | |
384 | retval = diff_tree(&t1, &t2, base, opt); | |
385 | if (DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) { | |
386 | init_tree_desc(&t1, tree1, size1); | |
387 | init_tree_desc(&t2, tree2, size2); | |
388 | try_to_follow_renames(&t1, &t2, base, opt); | |
389 | } | |
390 | free(tree1); | |
391 | free(tree2); | |
392 | return retval; | |
393 | } | |
394 | ||
395 | int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt) | |
396 | { | |
397 | int retval; | |
398 | void *tree; | |
399 | unsigned long size; | |
400 | struct tree_desc empty, real; | |
401 | ||
402 | tree = read_object_with_reference(new, tree_type, &size, NULL); | |
403 | if (!tree) | |
404 | die("unable to read root tree (%s)", sha1_to_hex(new)); | |
405 | init_tree_desc(&real, tree, size); | |
406 | ||
407 | init_tree_desc(&empty, "", 0); | |
408 | retval = diff_tree(&empty, &real, base, opt); | |
409 | free(tree); | |
410 | return retval; | |
411 | } | |
412 | ||
413 | static int count_paths(const char **paths) | |
414 | { | |
415 | int i = 0; | |
416 | while (*paths++) | |
417 | i++; | |
418 | return i; | |
419 | } | |
420 | ||
421 | void diff_tree_release_paths(struct diff_options *opt) | |
422 | { | |
423 | free(opt->pathlens); | |
424 | } | |
425 | ||
426 | void diff_tree_setup_paths(const char **p, struct diff_options *opt) | |
427 | { | |
428 | opt->nr_paths = 0; | |
429 | opt->pathlens = NULL; | |
430 | opt->paths = NULL; | |
431 | ||
432 | if (p) { | |
433 | int i; | |
434 | ||
435 | opt->paths = p; | |
436 | opt->nr_paths = count_paths(p); | |
437 | if (opt->nr_paths == 0) { | |
438 | opt->pathlens = NULL; | |
439 | return; | |
440 | } | |
441 | opt->pathlens = xmalloc(opt->nr_paths * sizeof(int)); | |
442 | for (i=0; i < opt->nr_paths; i++) | |
443 | opt->pathlens[i] = strlen(p[i]); | |
444 | } | |
445 | } |