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Commit | Line | Data |
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a2ad79ce CC |
1 | #include "cache.h" |
2 | #include "commit.h" | |
3 | #include "diff.h" | |
4 | #include "revision.h" | |
1bf072e3 CC |
5 | #include "refs.h" |
6 | #include "list-objects.h" | |
3b437b0d | 7 | #include "quote.h" |
4eb5b646 | 8 | #include "sha1-lookup.h" |
a2ad79ce CC |
9 | #include "bisect.h" |
10 | ||
95188648 CC |
11 | static unsigned char (*skipped_sha1)[20]; |
12 | static int skipped_sha1_nr; | |
1bf072e3 CC |
13 | static int skipped_sha1_alloc; |
14 | ||
15 | static const char **rev_argv; | |
16 | static int rev_argv_nr; | |
17 | static int rev_argv_alloc; | |
95188648 | 18 | |
a2ad79ce CC |
19 | /* bits #0-15 in revision.h */ |
20 | ||
21 | #define COUNTED (1u<<16) | |
22 | ||
23 | /* | |
24 | * This is a truly stupid algorithm, but it's only | |
25 | * used for bisection, and we just don't care enough. | |
26 | * | |
27 | * We care just barely enough to avoid recursing for | |
28 | * non-merge entries. | |
29 | */ | |
30 | static int count_distance(struct commit_list *entry) | |
31 | { | |
32 | int nr = 0; | |
33 | ||
34 | while (entry) { | |
35 | struct commit *commit = entry->item; | |
36 | struct commit_list *p; | |
37 | ||
38 | if (commit->object.flags & (UNINTERESTING | COUNTED)) | |
39 | break; | |
40 | if (!(commit->object.flags & TREESAME)) | |
41 | nr++; | |
42 | commit->object.flags |= COUNTED; | |
43 | p = commit->parents; | |
44 | entry = p; | |
45 | if (p) { | |
46 | p = p->next; | |
47 | while (p) { | |
48 | nr += count_distance(p); | |
49 | p = p->next; | |
50 | } | |
51 | } | |
52 | } | |
53 | ||
54 | return nr; | |
55 | } | |
56 | ||
57 | static void clear_distance(struct commit_list *list) | |
58 | { | |
59 | while (list) { | |
60 | struct commit *commit = list->item; | |
61 | commit->object.flags &= ~COUNTED; | |
62 | list = list->next; | |
63 | } | |
64 | } | |
65 | ||
66 | #define DEBUG_BISECT 0 | |
67 | ||
68 | static inline int weight(struct commit_list *elem) | |
69 | { | |
70 | return *((int*)(elem->item->util)); | |
71 | } | |
72 | ||
73 | static inline void weight_set(struct commit_list *elem, int weight) | |
74 | { | |
75 | *((int*)(elem->item->util)) = weight; | |
76 | } | |
77 | ||
78 | static int count_interesting_parents(struct commit *commit) | |
79 | { | |
80 | struct commit_list *p; | |
81 | int count; | |
82 | ||
83 | for (count = 0, p = commit->parents; p; p = p->next) { | |
84 | if (p->item->object.flags & UNINTERESTING) | |
85 | continue; | |
86 | count++; | |
87 | } | |
88 | return count; | |
89 | } | |
90 | ||
91 | static inline int halfway(struct commit_list *p, int nr) | |
92 | { | |
93 | /* | |
94 | * Don't short-cut something we are not going to return! | |
95 | */ | |
96 | if (p->item->object.flags & TREESAME) | |
97 | return 0; | |
98 | if (DEBUG_BISECT) | |
99 | return 0; | |
100 | /* | |
101 | * 2 and 3 are halfway of 5. | |
102 | * 3 is halfway of 6 but 2 and 4 are not. | |
103 | */ | |
104 | switch (2 * weight(p) - nr) { | |
105 | case -1: case 0: case 1: | |
106 | return 1; | |
107 | default: | |
108 | return 0; | |
109 | } | |
110 | } | |
111 | ||
112 | #if !DEBUG_BISECT | |
113 | #define show_list(a,b,c,d) do { ; } while (0) | |
114 | #else | |
115 | static void show_list(const char *debug, int counted, int nr, | |
116 | struct commit_list *list) | |
117 | { | |
118 | struct commit_list *p; | |
119 | ||
120 | fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr); | |
121 | ||
122 | for (p = list; p; p = p->next) { | |
123 | struct commit_list *pp; | |
124 | struct commit *commit = p->item; | |
125 | unsigned flags = commit->object.flags; | |
126 | enum object_type type; | |
127 | unsigned long size; | |
128 | char *buf = read_sha1_file(commit->object.sha1, &type, &size); | |
129 | char *ep, *sp; | |
130 | ||
131 | fprintf(stderr, "%c%c%c ", | |
132 | (flags & TREESAME) ? ' ' : 'T', | |
133 | (flags & UNINTERESTING) ? 'U' : ' ', | |
134 | (flags & COUNTED) ? 'C' : ' '); | |
135 | if (commit->util) | |
136 | fprintf(stderr, "%3d", weight(p)); | |
137 | else | |
138 | fprintf(stderr, "---"); | |
139 | fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1)); | |
140 | for (pp = commit->parents; pp; pp = pp->next) | |
141 | fprintf(stderr, " %.*s", 8, | |
142 | sha1_to_hex(pp->item->object.sha1)); | |
143 | ||
144 | sp = strstr(buf, "\n\n"); | |
145 | if (sp) { | |
146 | sp += 2; | |
147 | for (ep = sp; *ep && *ep != '\n'; ep++) | |
148 | ; | |
149 | fprintf(stderr, " %.*s", (int)(ep - sp), sp); | |
150 | } | |
151 | fprintf(stderr, "\n"); | |
152 | } | |
153 | } | |
154 | #endif /* DEBUG_BISECT */ | |
155 | ||
156 | static struct commit_list *best_bisection(struct commit_list *list, int nr) | |
157 | { | |
158 | struct commit_list *p, *best; | |
159 | int best_distance = -1; | |
160 | ||
161 | best = list; | |
162 | for (p = list; p; p = p->next) { | |
163 | int distance; | |
164 | unsigned flags = p->item->object.flags; | |
165 | ||
166 | if (flags & TREESAME) | |
167 | continue; | |
168 | distance = weight(p); | |
169 | if (nr - distance < distance) | |
170 | distance = nr - distance; | |
171 | if (distance > best_distance) { | |
172 | best = p; | |
173 | best_distance = distance; | |
174 | } | |
175 | } | |
176 | ||
177 | return best; | |
178 | } | |
179 | ||
180 | struct commit_dist { | |
181 | struct commit *commit; | |
182 | int distance; | |
183 | }; | |
184 | ||
185 | static int compare_commit_dist(const void *a_, const void *b_) | |
186 | { | |
187 | struct commit_dist *a, *b; | |
188 | ||
189 | a = (struct commit_dist *)a_; | |
190 | b = (struct commit_dist *)b_; | |
191 | if (a->distance != b->distance) | |
192 | return b->distance - a->distance; /* desc sort */ | |
193 | return hashcmp(a->commit->object.sha1, b->commit->object.sha1); | |
194 | } | |
195 | ||
196 | static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr) | |
197 | { | |
198 | struct commit_list *p; | |
199 | struct commit_dist *array = xcalloc(nr, sizeof(*array)); | |
200 | int cnt, i; | |
201 | ||
202 | for (p = list, cnt = 0; p; p = p->next) { | |
203 | int distance; | |
204 | unsigned flags = p->item->object.flags; | |
205 | ||
206 | if (flags & TREESAME) | |
207 | continue; | |
208 | distance = weight(p); | |
209 | if (nr - distance < distance) | |
210 | distance = nr - distance; | |
211 | array[cnt].commit = p->item; | |
212 | array[cnt].distance = distance; | |
213 | cnt++; | |
214 | } | |
215 | qsort(array, cnt, sizeof(*array), compare_commit_dist); | |
216 | for (p = list, i = 0; i < cnt; i++) { | |
217 | struct name_decoration *r = xmalloc(sizeof(*r) + 100); | |
218 | struct object *obj = &(array[i].commit->object); | |
219 | ||
220 | sprintf(r->name, "dist=%d", array[i].distance); | |
221 | r->next = add_decoration(&name_decoration, obj, r); | |
222 | p->item = array[i].commit; | |
223 | p = p->next; | |
224 | } | |
225 | if (p) | |
226 | p->next = NULL; | |
227 | free(array); | |
228 | return list; | |
229 | } | |
230 | ||
231 | /* | |
232 | * zero or positive weight is the number of interesting commits it can | |
233 | * reach, including itself. Especially, weight = 0 means it does not | |
234 | * reach any tree-changing commits (e.g. just above uninteresting one | |
235 | * but traversal is with pathspec). | |
236 | * | |
237 | * weight = -1 means it has one parent and its distance is yet to | |
238 | * be computed. | |
239 | * | |
240 | * weight = -2 means it has more than one parent and its distance is | |
241 | * unknown. After running count_distance() first, they will get zero | |
242 | * or positive distance. | |
243 | */ | |
244 | static struct commit_list *do_find_bisection(struct commit_list *list, | |
245 | int nr, int *weights, | |
246 | int find_all) | |
247 | { | |
248 | int n, counted; | |
249 | struct commit_list *p; | |
250 | ||
251 | counted = 0; | |
252 | ||
253 | for (n = 0, p = list; p; p = p->next) { | |
254 | struct commit *commit = p->item; | |
255 | unsigned flags = commit->object.flags; | |
256 | ||
257 | p->item->util = &weights[n++]; | |
258 | switch (count_interesting_parents(commit)) { | |
259 | case 0: | |
260 | if (!(flags & TREESAME)) { | |
261 | weight_set(p, 1); | |
262 | counted++; | |
263 | show_list("bisection 2 count one", | |
264 | counted, nr, list); | |
265 | } | |
266 | /* | |
267 | * otherwise, it is known not to reach any | |
268 | * tree-changing commit and gets weight 0. | |
269 | */ | |
270 | break; | |
271 | case 1: | |
272 | weight_set(p, -1); | |
273 | break; | |
274 | default: | |
275 | weight_set(p, -2); | |
276 | break; | |
277 | } | |
278 | } | |
279 | ||
280 | show_list("bisection 2 initialize", counted, nr, list); | |
281 | ||
282 | /* | |
283 | * If you have only one parent in the resulting set | |
284 | * then you can reach one commit more than that parent | |
285 | * can reach. So we do not have to run the expensive | |
286 | * count_distance() for single strand of pearls. | |
287 | * | |
288 | * However, if you have more than one parents, you cannot | |
289 | * just add their distance and one for yourself, since | |
290 | * they usually reach the same ancestor and you would | |
291 | * end up counting them twice that way. | |
292 | * | |
293 | * So we will first count distance of merges the usual | |
294 | * way, and then fill the blanks using cheaper algorithm. | |
295 | */ | |
296 | for (p = list; p; p = p->next) { | |
297 | if (p->item->object.flags & UNINTERESTING) | |
298 | continue; | |
299 | if (weight(p) != -2) | |
300 | continue; | |
301 | weight_set(p, count_distance(p)); | |
302 | clear_distance(list); | |
303 | ||
304 | /* Does it happen to be at exactly half-way? */ | |
305 | if (!find_all && halfway(p, nr)) | |
306 | return p; | |
307 | counted++; | |
308 | } | |
309 | ||
310 | show_list("bisection 2 count_distance", counted, nr, list); | |
311 | ||
312 | while (counted < nr) { | |
313 | for (p = list; p; p = p->next) { | |
314 | struct commit_list *q; | |
315 | unsigned flags = p->item->object.flags; | |
316 | ||
317 | if (0 <= weight(p)) | |
318 | continue; | |
319 | for (q = p->item->parents; q; q = q->next) { | |
320 | if (q->item->object.flags & UNINTERESTING) | |
321 | continue; | |
322 | if (0 <= weight(q)) | |
323 | break; | |
324 | } | |
325 | if (!q) | |
326 | continue; | |
327 | ||
328 | /* | |
329 | * weight for p is unknown but q is known. | |
330 | * add one for p itself if p is to be counted, | |
331 | * otherwise inherit it from q directly. | |
332 | */ | |
333 | if (!(flags & TREESAME)) { | |
334 | weight_set(p, weight(q)+1); | |
335 | counted++; | |
336 | show_list("bisection 2 count one", | |
337 | counted, nr, list); | |
338 | } | |
339 | else | |
340 | weight_set(p, weight(q)); | |
341 | ||
342 | /* Does it happen to be at exactly half-way? */ | |
343 | if (!find_all && halfway(p, nr)) | |
344 | return p; | |
345 | } | |
346 | } | |
347 | ||
348 | show_list("bisection 2 counted all", counted, nr, list); | |
349 | ||
350 | if (!find_all) | |
351 | return best_bisection(list, nr); | |
352 | else | |
353 | return best_bisection_sorted(list, nr); | |
354 | } | |
355 | ||
356 | struct commit_list *find_bisection(struct commit_list *list, | |
357 | int *reaches, int *all, | |
358 | int find_all) | |
359 | { | |
360 | int nr, on_list; | |
361 | struct commit_list *p, *best, *next, *last; | |
362 | int *weights; | |
363 | ||
364 | show_list("bisection 2 entry", 0, 0, list); | |
365 | ||
366 | /* | |
367 | * Count the number of total and tree-changing items on the | |
368 | * list, while reversing the list. | |
369 | */ | |
370 | for (nr = on_list = 0, last = NULL, p = list; | |
371 | p; | |
372 | p = next) { | |
373 | unsigned flags = p->item->object.flags; | |
374 | ||
375 | next = p->next; | |
376 | if (flags & UNINTERESTING) | |
377 | continue; | |
378 | p->next = last; | |
379 | last = p; | |
380 | if (!(flags & TREESAME)) | |
381 | nr++; | |
382 | on_list++; | |
383 | } | |
384 | list = last; | |
385 | show_list("bisection 2 sorted", 0, nr, list); | |
386 | ||
387 | *all = nr; | |
388 | weights = xcalloc(on_list, sizeof(*weights)); | |
389 | ||
390 | /* Do the real work of finding bisection commit. */ | |
391 | best = do_find_bisection(list, nr, weights, find_all); | |
392 | if (best) { | |
393 | if (!find_all) | |
394 | best->next = NULL; | |
395 | *reaches = weight(best); | |
396 | } | |
397 | free(weights); | |
398 | return best; | |
399 | } | |
400 | ||
1bf072e3 CC |
401 | static int register_ref(const char *refname, const unsigned char *sha1, |
402 | int flags, void *cb_data) | |
403 | { | |
404 | if (!strcmp(refname, "bad")) { | |
405 | ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc); | |
406 | rev_argv[rev_argv_nr++] = xstrdup(sha1_to_hex(sha1)); | |
407 | } else if (!prefixcmp(refname, "good-")) { | |
408 | const char *hex = sha1_to_hex(sha1); | |
409 | char *good = xmalloc(strlen(hex) + 2); | |
410 | *good = '^'; | |
411 | memcpy(good + 1, hex, strlen(hex) + 1); | |
412 | ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc); | |
413 | rev_argv[rev_argv_nr++] = good; | |
414 | } else if (!prefixcmp(refname, "skip-")) { | |
415 | ALLOC_GROW(skipped_sha1, skipped_sha1_nr + 1, | |
416 | skipped_sha1_alloc); | |
417 | hashcpy(skipped_sha1[skipped_sha1_nr++], sha1); | |
418 | } | |
419 | ||
420 | return 0; | |
421 | } | |
422 | ||
423 | static int read_bisect_refs(void) | |
424 | { | |
425 | return for_each_ref_in("refs/bisect/", register_ref, NULL); | |
426 | } | |
427 | ||
3b437b0d CC |
428 | void read_bisect_paths(void) |
429 | { | |
430 | struct strbuf str = STRBUF_INIT; | |
431 | const char *filename = git_path("BISECT_NAMES"); | |
432 | FILE *fp = fopen(filename, "r"); | |
433 | ||
434 | if (!fp) | |
435 | die("Could not open file '%s': %s", filename, strerror(errno)); | |
436 | ||
437 | while (strbuf_getline(&str, fp, '\n') != EOF) { | |
438 | char *quoted; | |
439 | int res; | |
440 | ||
441 | strbuf_trim(&str); | |
442 | quoted = strbuf_detach(&str, NULL); | |
443 | res = sq_dequote_to_argv(quoted, &rev_argv, | |
444 | &rev_argv_nr, &rev_argv_alloc); | |
445 | if (res) | |
446 | die("Badly quoted content in file '%s': %s", | |
447 | filename, quoted); | |
448 | } | |
449 | ||
450 | strbuf_release(&str); | |
451 | fclose(fp); | |
452 | } | |
453 | ||
95188648 CC |
454 | static int skipcmp(const void *a, const void *b) |
455 | { | |
456 | return hashcmp(a, b); | |
457 | } | |
458 | ||
459 | static void prepare_skipped(void) | |
460 | { | |
461 | qsort(skipped_sha1, skipped_sha1_nr, sizeof(*skipped_sha1), skipcmp); | |
462 | } | |
463 | ||
4eb5b646 CC |
464 | static const unsigned char *skipped_sha1_access(size_t index, void *table) |
465 | { | |
466 | unsigned char (*skipped)[20] = table; | |
467 | return skipped[index]; | |
468 | } | |
469 | ||
95188648 CC |
470 | static int lookup_skipped(unsigned char *sha1) |
471 | { | |
4eb5b646 CC |
472 | return sha1_pos(sha1, skipped_sha1, skipped_sha1_nr, |
473 | skipped_sha1_access); | |
95188648 CC |
474 | } |
475 | ||
476 | struct commit_list *filter_skipped(struct commit_list *list, | |
477 | struct commit_list **tried, | |
478 | int show_all) | |
479 | { | |
480 | struct commit_list *filtered = NULL, **f = &filtered; | |
481 | ||
482 | *tried = NULL; | |
483 | ||
484 | if (!skipped_sha1_nr) | |
485 | return list; | |
486 | ||
487 | prepare_skipped(); | |
488 | ||
489 | while (list) { | |
490 | struct commit_list *next = list->next; | |
491 | list->next = NULL; | |
492 | if (0 <= lookup_skipped(list->item->object.sha1)) { | |
493 | /* Move current to tried list */ | |
494 | *tried = list; | |
495 | tried = &list->next; | |
496 | } else { | |
497 | if (!show_all) | |
498 | return list; | |
499 | /* Move current to filtered list */ | |
500 | *f = list; | |
501 | f = &list->next; | |
502 | } | |
503 | list = next; | |
504 | } | |
505 | ||
506 | return filtered; | |
507 | } | |
1bf072e3 | 508 | |
3b437b0d | 509 | static void bisect_rev_setup(struct rev_info *revs, const char *prefix) |
1bf072e3 | 510 | { |
3b437b0d CC |
511 | init_revisions(revs, prefix); |
512 | revs->abbrev = 0; | |
513 | revs->commit_format = CMIT_FMT_UNSPECIFIED; | |
1bf072e3 CC |
514 | |
515 | /* argv[0] will be ignored by setup_revisions */ | |
516 | ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc); | |
517 | rev_argv[rev_argv_nr++] = xstrdup("bisect_rev_setup"); | |
518 | ||
519 | if (read_bisect_refs()) | |
520 | die("reading bisect refs failed"); | |
521 | ||
522 | ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc); | |
523 | rev_argv[rev_argv_nr++] = xstrdup("--"); | |
524 | ||
3b437b0d CC |
525 | read_bisect_paths(); |
526 | ||
527 | ALLOC_GROW(rev_argv, rev_argv_nr + 1, rev_argv_alloc); | |
528 | rev_argv[rev_argv_nr++] = NULL; | |
529 | ||
530 | setup_revisions(rev_argv_nr, rev_argv, revs, NULL); | |
531 | ||
532 | revs->limited = 1; | |
533 | } | |
534 | ||
535 | int bisect_next_vars(const char *prefix) | |
536 | { | |
537 | struct rev_info revs; | |
d797257e | 538 | struct rev_list_info info; |
3b437b0d | 539 | int reaches = 0, all = 0; |
1bf072e3 | 540 | |
d797257e CC |
541 | memset(&info, 0, sizeof(info)); |
542 | info.revs = &revs; | |
13858e57 | 543 | info.bisect_show_flags = BISECT_SHOW_TRIED | BISECT_SHOW_STRINGED; |
d797257e | 544 | |
3b437b0d | 545 | bisect_rev_setup(&revs, prefix); |
1bf072e3 CC |
546 | |
547 | if (prepare_revision_walk(&revs)) | |
548 | die("revision walk setup failed"); | |
549 | if (revs.tree_objects) | |
550 | mark_edges_uninteresting(revs.commits, &revs, NULL); | |
551 | ||
552 | revs.commits = find_bisection(revs.commits, &reaches, &all, | |
553 | !!skipped_sha1_nr); | |
554 | ||
13858e57 | 555 | return show_bisect_vars(&info, reaches, all); |
1bf072e3 | 556 | } |