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a2ad79c @chriscool rev-list: move bisect related code into its own file
chriscool authored
1 #include "cache.h"
2 #include "commit.h"
3 #include "diff.h"
4 #include "revision.h"
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
5 #include "refs.h"
6 #include "list-objects.h"
3b437b0 @chriscool bisect: implement "read_bisect_paths" to read paths in "$GIT_DIR/BISE…
chriscool authored
7 #include "quote.h"
4eb5b64 @chriscool bisect: use the new generic "sha1_pos" function to lookup sha1
chriscool authored
8 #include "sha1-lookup.h"
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
9 #include "run-command.h"
e22278c @chriscool bisect: display first bad commit without forking a new process
chriscool authored
10 #include "log-tree.h"
a2ad79c @chriscool rev-list: move bisect related code into its own file
chriscool authored
11 #include "bisect.h"
12
6212b1a @chriscool bisect: use "sha1_array" to store skipped revisions
chriscool authored
13 struct sha1_array {
14 unsigned char (*sha1)[20];
15 int sha1_nr;
16 int sha1_alloc;
1da8c4f @chriscool bisect: automatically sort sha1_array if needed when looking it up
chriscool authored
17 int sorted;
6212b1a @chriscool bisect: use "sha1_array" to store skipped revisions
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18 };
19
fad2d31 @chriscool bisect: store good revisions in a "sha1_array"
chriscool authored
20 static struct sha1_array good_revs;
6212b1a @chriscool bisect: use "sha1_array" to store skipped revisions
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21 static struct sha1_array skipped_revs;
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
22
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
23 static const unsigned char *current_bad_sha1;
24
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
chriscool authored
25 struct argv_array {
26 const char **argv;
27 int argv_nr;
28 int argv_alloc;
29 };
30
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
31 static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL};
32 static const char *argv_show_branch[] = {"show-branch", NULL, NULL};
33
a2ad79c @chriscool rev-list: move bisect related code into its own file
chriscool authored
34 /* bits #0-15 in revision.h */
35
36 #define COUNTED (1u<<16)
37
38 /*
39 * This is a truly stupid algorithm, but it's only
40 * used for bisection, and we just don't care enough.
41 *
42 * We care just barely enough to avoid recursing for
43 * non-merge entries.
44 */
45 static int count_distance(struct commit_list *entry)
46 {
47 int nr = 0;
48
49 while (entry) {
50 struct commit *commit = entry->item;
51 struct commit_list *p;
52
53 if (commit->object.flags & (UNINTERESTING | COUNTED))
54 break;
55 if (!(commit->object.flags & TREESAME))
56 nr++;
57 commit->object.flags |= COUNTED;
58 p = commit->parents;
59 entry = p;
60 if (p) {
61 p = p->next;
62 while (p) {
63 nr += count_distance(p);
64 p = p->next;
65 }
66 }
67 }
68
69 return nr;
70 }
71
72 static void clear_distance(struct commit_list *list)
73 {
74 while (list) {
75 struct commit *commit = list->item;
76 commit->object.flags &= ~COUNTED;
77 list = list->next;
78 }
79 }
80
81 #define DEBUG_BISECT 0
82
83 static inline int weight(struct commit_list *elem)
84 {
85 return *((int*)(elem->item->util));
86 }
87
88 static inline void weight_set(struct commit_list *elem, int weight)
89 {
90 *((int*)(elem->item->util)) = weight;
91 }
92
93 static int count_interesting_parents(struct commit *commit)
94 {
95 struct commit_list *p;
96 int count;
97
98 for (count = 0, p = commit->parents; p; p = p->next) {
99 if (p->item->object.flags & UNINTERESTING)
100 continue;
101 count++;
102 }
103 return count;
104 }
105
106 static inline int halfway(struct commit_list *p, int nr)
107 {
108 /*
109 * Don't short-cut something we are not going to return!
110 */
111 if (p->item->object.flags & TREESAME)
112 return 0;
113 if (DEBUG_BISECT)
114 return 0;
115 /*
116 * 2 and 3 are halfway of 5.
117 * 3 is halfway of 6 but 2 and 4 are not.
118 */
119 switch (2 * weight(p) - nr) {
120 case -1: case 0: case 1:
121 return 1;
122 default:
123 return 0;
124 }
125 }
126
127 #if !DEBUG_BISECT
128 #define show_list(a,b,c,d) do { ; } while (0)
129 #else
130 static void show_list(const char *debug, int counted, int nr,
131 struct commit_list *list)
132 {
133 struct commit_list *p;
134
135 fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
136
137 for (p = list; p; p = p->next) {
138 struct commit_list *pp;
139 struct commit *commit = p->item;
140 unsigned flags = commit->object.flags;
141 enum object_type type;
142 unsigned long size;
143 char *buf = read_sha1_file(commit->object.sha1, &type, &size);
144 char *ep, *sp;
145
146 fprintf(stderr, "%c%c%c ",
147 (flags & TREESAME) ? ' ' : 'T',
148 (flags & UNINTERESTING) ? 'U' : ' ',
149 (flags & COUNTED) ? 'C' : ' ');
150 if (commit->util)
151 fprintf(stderr, "%3d", weight(p));
152 else
153 fprintf(stderr, "---");
154 fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
155 for (pp = commit->parents; pp; pp = pp->next)
156 fprintf(stderr, " %.*s", 8,
157 sha1_to_hex(pp->item->object.sha1));
158
159 sp = strstr(buf, "\n\n");
160 if (sp) {
161 sp += 2;
162 for (ep = sp; *ep && *ep != '\n'; ep++)
163 ;
164 fprintf(stderr, " %.*s", (int)(ep - sp), sp);
165 }
166 fprintf(stderr, "\n");
167 }
168 }
169 #endif /* DEBUG_BISECT */
170
171 static struct commit_list *best_bisection(struct commit_list *list, int nr)
172 {
173 struct commit_list *p, *best;
174 int best_distance = -1;
175
176 best = list;
177 for (p = list; p; p = p->next) {
178 int distance;
179 unsigned flags = p->item->object.flags;
180
181 if (flags & TREESAME)
182 continue;
183 distance = weight(p);
184 if (nr - distance < distance)
185 distance = nr - distance;
186 if (distance > best_distance) {
187 best = p;
188 best_distance = distance;
189 }
190 }
191
192 return best;
193 }
194
195 struct commit_dist {
196 struct commit *commit;
197 int distance;
198 };
199
200 static int compare_commit_dist(const void *a_, const void *b_)
201 {
202 struct commit_dist *a, *b;
203
204 a = (struct commit_dist *)a_;
205 b = (struct commit_dist *)b_;
206 if (a->distance != b->distance)
207 return b->distance - a->distance; /* desc sort */
208 return hashcmp(a->commit->object.sha1, b->commit->object.sha1);
209 }
210
211 static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr)
212 {
213 struct commit_list *p;
214 struct commit_dist *array = xcalloc(nr, sizeof(*array));
215 int cnt, i;
216
217 for (p = list, cnt = 0; p; p = p->next) {
218 int distance;
219 unsigned flags = p->item->object.flags;
220
221 if (flags & TREESAME)
222 continue;
223 distance = weight(p);
224 if (nr - distance < distance)
225 distance = nr - distance;
226 array[cnt].commit = p->item;
227 array[cnt].distance = distance;
228 cnt++;
229 }
230 qsort(array, cnt, sizeof(*array), compare_commit_dist);
231 for (p = list, i = 0; i < cnt; i++) {
232 struct name_decoration *r = xmalloc(sizeof(*r) + 100);
233 struct object *obj = &(array[i].commit->object);
234
235 sprintf(r->name, "dist=%d", array[i].distance);
236 r->next = add_decoration(&name_decoration, obj, r);
237 p->item = array[i].commit;
238 p = p->next;
239 }
240 if (p)
241 p->next = NULL;
242 free(array);
243 return list;
244 }
245
246 /*
247 * zero or positive weight is the number of interesting commits it can
248 * reach, including itself. Especially, weight = 0 means it does not
249 * reach any tree-changing commits (e.g. just above uninteresting one
250 * but traversal is with pathspec).
251 *
252 * weight = -1 means it has one parent and its distance is yet to
253 * be computed.
254 *
255 * weight = -2 means it has more than one parent and its distance is
256 * unknown. After running count_distance() first, they will get zero
257 * or positive distance.
258 */
259 static struct commit_list *do_find_bisection(struct commit_list *list,
260 int nr, int *weights,
261 int find_all)
262 {
263 int n, counted;
264 struct commit_list *p;
265
266 counted = 0;
267
268 for (n = 0, p = list; p; p = p->next) {
269 struct commit *commit = p->item;
270 unsigned flags = commit->object.flags;
271
272 p->item->util = &weights[n++];
273 switch (count_interesting_parents(commit)) {
274 case 0:
275 if (!(flags & TREESAME)) {
276 weight_set(p, 1);
277 counted++;
278 show_list("bisection 2 count one",
279 counted, nr, list);
280 }
281 /*
282 * otherwise, it is known not to reach any
283 * tree-changing commit and gets weight 0.
284 */
285 break;
286 case 1:
287 weight_set(p, -1);
288 break;
289 default:
290 weight_set(p, -2);
291 break;
292 }
293 }
294
295 show_list("bisection 2 initialize", counted, nr, list);
296
297 /*
298 * If you have only one parent in the resulting set
299 * then you can reach one commit more than that parent
300 * can reach. So we do not have to run the expensive
301 * count_distance() for single strand of pearls.
302 *
303 * However, if you have more than one parents, you cannot
304 * just add their distance and one for yourself, since
305 * they usually reach the same ancestor and you would
306 * end up counting them twice that way.
307 *
308 * So we will first count distance of merges the usual
309 * way, and then fill the blanks using cheaper algorithm.
310 */
311 for (p = list; p; p = p->next) {
312 if (p->item->object.flags & UNINTERESTING)
313 continue;
314 if (weight(p) != -2)
315 continue;
316 weight_set(p, count_distance(p));
317 clear_distance(list);
318
319 /* Does it happen to be at exactly half-way? */
320 if (!find_all && halfway(p, nr))
321 return p;
322 counted++;
323 }
324
325 show_list("bisection 2 count_distance", counted, nr, list);
326
327 while (counted < nr) {
328 for (p = list; p; p = p->next) {
329 struct commit_list *q;
330 unsigned flags = p->item->object.flags;
331
332 if (0 <= weight(p))
333 continue;
334 for (q = p->item->parents; q; q = q->next) {
335 if (q->item->object.flags & UNINTERESTING)
336 continue;
337 if (0 <= weight(q))
338 break;
339 }
340 if (!q)
341 continue;
342
343 /*
344 * weight for p is unknown but q is known.
345 * add one for p itself if p is to be counted,
346 * otherwise inherit it from q directly.
347 */
348 if (!(flags & TREESAME)) {
349 weight_set(p, weight(q)+1);
350 counted++;
351 show_list("bisection 2 count one",
352 counted, nr, list);
353 }
354 else
355 weight_set(p, weight(q));
356
357 /* Does it happen to be at exactly half-way? */
358 if (!find_all && halfway(p, nr))
359 return p;
360 }
361 }
362
363 show_list("bisection 2 counted all", counted, nr, list);
364
365 if (!find_all)
366 return best_bisection(list, nr);
367 else
368 return best_bisection_sorted(list, nr);
369 }
370
371 struct commit_list *find_bisection(struct commit_list *list,
372 int *reaches, int *all,
373 int find_all)
374 {
375 int nr, on_list;
376 struct commit_list *p, *best, *next, *last;
377 int *weights;
378
379 show_list("bisection 2 entry", 0, 0, list);
380
381 /*
382 * Count the number of total and tree-changing items on the
383 * list, while reversing the list.
384 */
385 for (nr = on_list = 0, last = NULL, p = list;
386 p;
387 p = next) {
388 unsigned flags = p->item->object.flags;
389
390 next = p->next;
391 if (flags & UNINTERESTING)
392 continue;
393 p->next = last;
394 last = p;
395 if (!(flags & TREESAME))
396 nr++;
397 on_list++;
398 }
399 list = last;
400 show_list("bisection 2 sorted", 0, nr, list);
401
402 *all = nr;
403 weights = xcalloc(on_list, sizeof(*weights));
404
405 /* Do the real work of finding bisection commit. */
406 best = do_find_bisection(list, nr, weights, find_all);
407 if (best) {
408 if (!find_all)
409 best->next = NULL;
410 *reaches = weight(best);
411 }
412 free(weights);
413 return best;
414 }
415
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
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416 static void argv_array_push(struct argv_array *array, const char *string)
3755ccd @chriscool bisect: implement "rev_argv_push" to fill an argv with revs
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417 {
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
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418 ALLOC_GROW(array->argv, array->argv_nr + 1, array->argv_alloc);
419 array->argv[array->argv_nr++] = string;
420 }
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421
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422 static void argv_array_push_sha1(struct argv_array *array,
423 const unsigned char *sha1,
424 const char *format)
425 {
426 struct strbuf buf = STRBUF_INIT;
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427 strbuf_addf(&buf, format, sha1_to_hex(sha1));
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
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428 argv_array_push(array, strbuf_detach(&buf, NULL));
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429 }
430
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431 static void sha1_array_push(struct sha1_array *array,
432 const unsigned char *sha1)
433 {
434 ALLOC_GROW(array->sha1, array->sha1_nr + 1, array->sha1_alloc);
435 hashcpy(array->sha1[array->sha1_nr++], sha1);
436 }
437
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
438 static int register_ref(const char *refname, const unsigned char *sha1,
439 int flags, void *cb_data)
440 {
441 if (!strcmp(refname, "bad")) {
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
442 current_bad_sha1 = sha1;
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
443 } else if (!prefixcmp(refname, "good-")) {
fad2d31 @chriscool bisect: store good revisions in a "sha1_array"
chriscool authored
444 sha1_array_push(&good_revs, sha1);
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
445 } else if (!prefixcmp(refname, "skip-")) {
fad2d31 @chriscool bisect: store good revisions in a "sha1_array"
chriscool authored
446 sha1_array_push(&skipped_revs, sha1);
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
447 }
448
449 return 0;
450 }
451
452 static int read_bisect_refs(void)
453 {
454 return for_each_ref_in("refs/bisect/", register_ref, NULL);
455 }
456
2af202b @torvalds Fix various sparse warnings in the git source code
torvalds authored
457 static void read_bisect_paths(struct argv_array *array)
3b437b0 @chriscool bisect: implement "read_bisect_paths" to read paths in "$GIT_DIR/BISE…
chriscool authored
458 {
459 struct strbuf str = STRBUF_INIT;
460 const char *filename = git_path("BISECT_NAMES");
461 FILE *fp = fopen(filename, "r");
462
463 if (!fp)
d824cbb @trast Convert existing die(..., strerror(errno)) to die_errno()
trast authored
464 die_errno("Could not open file '%s'", filename);
3b437b0 @chriscool bisect: implement "read_bisect_paths" to read paths in "$GIT_DIR/BISE…
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465
466 while (strbuf_getline(&str, fp, '\n') != EOF) {
467 char *quoted;
468 int res;
469
470 strbuf_trim(&str);
471 quoted = strbuf_detach(&str, NULL);
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472 res = sq_dequote_to_argv(quoted, &array->argv,
473 &array->argv_nr, &array->argv_alloc);
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chriscool authored
474 if (res)
475 die("Badly quoted content in file '%s': %s",
476 filename, quoted);
477 }
478
479 strbuf_release(&str);
480 fclose(fp);
481 }
482
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483 static int array_cmp(const void *a, const void *b)
9518864 @chriscool rev-list: call new "filter_skip" function
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484 {
485 return hashcmp(a, b);
486 }
487
aaaff9e @chriscool bisect: make skipped array functions more generic
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488 static void sort_sha1_array(struct sha1_array *array)
9518864 @chriscool rev-list: call new "filter_skip" function
chriscool authored
489 {
aaaff9e @chriscool bisect: make skipped array functions more generic
chriscool authored
490 qsort(array->sha1, array->sha1_nr, sizeof(*array->sha1), array_cmp);
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491
492 array->sorted = 1;
9518864 @chriscool rev-list: call new "filter_skip" function
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493 }
494
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495 static const unsigned char *sha1_access(size_t index, void *table)
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496 {
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497 unsigned char (*array)[20] = table;
498 return array[index];
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499 }
500
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501 static int lookup_sha1_array(struct sha1_array *array,
502 const unsigned char *sha1)
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503 {
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504 if (!array->sorted)
505 sort_sha1_array(array);
506
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507 return sha1_pos(sha1, array->sha1, array->sha1_nr, sha1_access);
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chriscool authored
508 }
509
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510 static char *join_sha1_array_hex(struct sha1_array *array, char delim)
511 {
512 struct strbuf joined_hexs = STRBUF_INIT;
513 int i;
514
515 for (i = 0; i < array->sha1_nr; i++) {
516 strbuf_addstr(&joined_hexs, sha1_to_hex(array->sha1[i]));
517 if (i + 1 < array->sha1_nr)
518 strbuf_addch(&joined_hexs, delim);
519 }
520
521 return strbuf_detach(&joined_hexs, NULL);
522 }
523
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524 /*
525 * In this function, passing a not NULL skipped_first is very special.
526 * It means that we want to know if the first commit in the list is
527 * skipped because we will want to test a commit away from it if it is
528 * indeed skipped.
529 * So if the first commit is skipped, we cannot take the shortcut to
530 * just "return list" when we find the first non skipped commit, we
531 * have to return a fully filtered list.
532 *
533 * We use (*skipped_first == -1) to mean "it has been found that the
534 * first commit is not skipped". In this case *skipped_first is set back
535 * to 0 just before the function returns.
536 */
9518864 @chriscool rev-list: call new "filter_skip" function
chriscool authored
537 struct commit_list *filter_skipped(struct commit_list *list,
538 struct commit_list **tried,
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539 int show_all,
540 int *count,
541 int *skipped_first)
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542 {
543 struct commit_list *filtered = NULL, **f = &filtered;
544
545 *tried = NULL;
546
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547 if (skipped_first)
548 *skipped_first = 0;
549 if (count)
550 *count = 0;
551
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552 if (!skipped_revs.sha1_nr)
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chriscool authored
553 return list;
554
555 while (list) {
556 struct commit_list *next = list->next;
557 list->next = NULL;
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558 if (0 <= lookup_sha1_array(&skipped_revs,
559 list->item->object.sha1)) {
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560 if (skipped_first && !*skipped_first)
561 *skipped_first = 1;
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chriscool authored
562 /* Move current to tried list */
563 *tried = list;
564 tried = &list->next;
565 } else {
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566 if (!show_all) {
567 if (!skipped_first || !*skipped_first)
568 return list;
569 } else if (skipped_first && !*skipped_first) {
570 /* This means we know it's not skipped */
571 *skipped_first = -1;
572 }
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573 /* Move current to filtered list */
574 *f = list;
575 f = &list->next;
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576 if (count)
577 (*count)++;
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578 }
579 list = next;
580 }
581
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582 if (skipped_first && *skipped_first == -1)
583 *skipped_first = 0;
584
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chriscool authored
585 return filtered;
586 }
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
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587
ebc9529 @chriscool bisect: use a PRNG with a bias when skipping away from untestable com…
chriscool authored
588 #define PRN_MODULO 32768
589
590 /*
591 * This is a pseudo random number generator based on "man 3 rand".
592 * It is not used properly because the seed is the argument and it
593 * is increased by one between each call, but that should not matter
594 * for this application.
595 */
596 int get_prn(int count) {
597 count = count * 1103515245 + 12345;
598 return ((unsigned)(count/65536) % PRN_MODULO);
599 }
600
601 /*
602 * Custom integer square root from
603 * http://en.wikipedia.org/wiki/Integer_square_root
604 */
605 static int sqrti(int val)
606 {
607 float d, x = val;
608
609 if (val == 0)
610 return 0;
611
612 do {
613 float y = (x + (float)val / x) / 2;
614 d = (y > x) ? y - x : x - y;
615 x = y;
616 } while (d >= 0.5);
617
618 return (int)x;
619 }
620
621 static struct commit_list *skip_away(struct commit_list *list, int count)
62d0b0d @chriscool bisect: when skipping, choose a commit away from a skipped commit
chriscool authored
622 {
623 struct commit_list *cur, *previous;
ebc9529 @chriscool bisect: use a PRNG with a bias when skipping away from untestable com…
chriscool authored
624 int prn, index, i;
625
626 prn = get_prn(count);
627 index = (count * prn / PRN_MODULO) * sqrti(prn) / sqrti(PRN_MODULO);
62d0b0d @chriscool bisect: when skipping, choose a commit away from a skipped commit
chriscool authored
628
629 cur = list;
630 previous = NULL;
631
632 for (i = 0; cur; cur = cur->next, i++) {
633 if (i == index) {
634 if (hashcmp(cur->item->object.sha1, current_bad_sha1))
635 return cur;
636 if (previous)
637 return previous;
638 return list;
639 }
640 previous = cur;
641 }
642
643 return list;
644 }
645
646 static struct commit_list *managed_skipped(struct commit_list *list,
647 struct commit_list **tried)
648 {
649 int count, skipped_first;
650
651 *tried = NULL;
652
653 if (!skipped_revs.sha1_nr)
654 return list;
655
656 list = filter_skipped(list, tried, 0, &count, &skipped_first);
657
658 if (!skipped_first)
659 return list;
660
ebc9529 @chriscool bisect: use a PRNG with a bias when skipping away from untestable com…
chriscool authored
661 return skip_away(list, count);
62d0b0d @chriscool bisect: when skipping, choose a commit away from a skipped commit
chriscool authored
662 }
663
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
664 static void bisect_rev_setup(struct rev_info *revs, const char *prefix,
665 const char *bad_format, const char *good_format,
666 int read_paths)
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
667 {
2b02069 @chriscool bisect: remove too much function nesting
chriscool authored
668 struct argv_array rev_argv = { NULL, 0, 0 };
fad2d31 @chriscool bisect: store good revisions in a "sha1_array"
chriscool authored
669 int i;
670
3b437b0 @chriscool bisect: implement "read_bisect_paths" to read paths in "$GIT_DIR/BISE…
chriscool authored
671 init_revisions(revs, prefix);
672 revs->abbrev = 0;
673 revs->commit_format = CMIT_FMT_UNSPECIFIED;
1bf072e @chriscool bisect--helper: implement "git bisect--helper"
chriscool authored
674
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
chriscool authored
675 /* rev_argv.argv[0] will be ignored by setup_revisions */
676 argv_array_push(&rev_argv, xstrdup("bisect_rev_setup"));
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
677 argv_array_push_sha1(&rev_argv, current_bad_sha1, bad_format);
fad2d31 @chriscool bisect: store good revisions in a "sha1_array"
chriscool authored
678 for (i = 0; i < good_revs.sha1_nr; i++)
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
679 argv_array_push_sha1(&rev_argv, good_revs.sha1[i],
680 good_format);
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
chriscool authored
681 argv_array_push(&rev_argv, xstrdup("--"));
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
682 if (read_paths)
683 read_bisect_paths(&rev_argv);
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
chriscool authored
684 argv_array_push(&rev_argv, NULL);
3b437b0 @chriscool bisect: implement "read_bisect_paths" to read paths in "$GIT_DIR/BISE…
chriscool authored
685
1c953a1 @chriscool bisect: use new "struct argv_array" to prepare argv for "setup_revisi…
chriscool authored
686 setup_revisions(rev_argv.argv_nr, rev_argv.argv, revs, NULL);
3b437b0 @chriscool bisect: implement "read_bisect_paths" to read paths in "$GIT_DIR/BISE…
chriscool authored
687 }
688
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
689 static void bisect_common(struct rev_info *revs)
2ace972 @chriscool bisect: move common bisect functionality to "bisect_common"
chriscool authored
690 {
691 if (prepare_revision_walk(revs))
692 die("revision walk setup failed");
693 if (revs->tree_objects)
694 mark_edges_uninteresting(revs->commits, revs, NULL);
695 }
696
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
697 static void exit_if_skipped_commits(struct commit_list *tried,
698 const unsigned char *bad)
699 {
700 if (!tried)
701 return;
702
703 printf("There are only 'skip'ped commits left to test.\n"
704 "The first bad commit could be any of:\n");
705 print_commit_list(tried, "%s\n", "%s\n");
706 if (bad)
707 printf("%s\n", sha1_to_hex(bad));
708 printf("We cannot bisect more!\n");
709 exit(2);
710 }
711
c053766 @chriscool bisect: implement the "check_merge_bases" function
chriscool authored
712 static int is_expected_rev(const unsigned char *sha1)
713 {
714 const char *filename = git_path("BISECT_EXPECTED_REV");
715 struct stat st;
716 struct strbuf str = STRBUF_INIT;
717 FILE *fp;
718 int res = 0;
719
720 if (stat(filename, &st) || !S_ISREG(st.st_mode))
721 return 0;
722
723 fp = fopen(filename, "r");
724 if (!fp)
725 return 0;
726
727 if (strbuf_getline(&str, fp, '\n') != EOF)
728 res = !strcmp(str.buf, sha1_to_hex(sha1));
729
730 strbuf_release(&str);
731 fclose(fp);
732
733 return res;
734 }
735
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
736 static void mark_expected_rev(char *bisect_rev_hex)
737 {
738 int len = strlen(bisect_rev_hex);
739 const char *filename = git_path("BISECT_EXPECTED_REV");
740 int fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
741
742 if (fd < 0)
d824cbb @trast Convert existing die(..., strerror(errno)) to die_errno()
trast authored
743 die_errno("could not create file '%s'", filename);
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
744
745 bisect_rev_hex[len] = '\n';
746 write_or_die(fd, bisect_rev_hex, len + 1);
747 bisect_rev_hex[len] = '\0';
748
749 if (close(fd) < 0)
750 die("closing file %s: %s", filename, strerror(errno));
751 }
752
753 static int bisect_checkout(char *bisect_rev_hex)
754 {
755 int res;
756
757 mark_expected_rev(bisect_rev_hex);
758
759 argv_checkout[2] = bisect_rev_hex;
760 res = run_command_v_opt(argv_checkout, RUN_GIT_CMD);
761 if (res)
762 exit(res);
763
764 argv_show_branch[1] = bisect_rev_hex;
765 return run_command_v_opt(argv_show_branch, RUN_GIT_CMD);
766 }
767
c053766 @chriscool bisect: implement the "check_merge_bases" function
chriscool authored
768 static struct commit *get_commit_reference(const unsigned char *sha1)
769 {
770 struct commit *r = lookup_commit_reference(sha1);
771 if (!r)
772 die("Not a valid commit name %s", sha1_to_hex(sha1));
773 return r;
774 }
775
776 static struct commit **get_bad_and_good_commits(int *rev_nr)
777 {
778 int len = 1 + good_revs.sha1_nr;
779 struct commit **rev = xmalloc(len * sizeof(*rev));
780 int i, n = 0;
781
782 rev[n++] = get_commit_reference(current_bad_sha1);
783 for (i = 0; i < good_revs.sha1_nr; i++)
784 rev[n++] = get_commit_reference(good_revs.sha1[i]);
785 *rev_nr = n;
786
787 return rev;
788 }
789
790 static void handle_bad_merge_base(void)
791 {
792 if (is_expected_rev(current_bad_sha1)) {
793 char *bad_hex = sha1_to_hex(current_bad_sha1);
794 char *good_hex = join_sha1_array_hex(&good_revs, ' ');
795
796 fprintf(stderr, "The merge base %s is bad.\n"
797 "This means the bug has been fixed "
798 "between %s and [%s].\n",
799 bad_hex, bad_hex, good_hex);
800
801 exit(3);
802 }
803
804 fprintf(stderr, "Some good revs are not ancestor of the bad rev.\n"
805 "git bisect cannot work properly in this case.\n"
806 "Maybe you mistake good and bad revs?\n");
807 exit(1);
808 }
809
2af202b @torvalds Fix various sparse warnings in the git source code
torvalds authored
810 static void handle_skipped_merge_base(const unsigned char *mb)
c053766 @chriscool bisect: implement the "check_merge_bases" function
chriscool authored
811 {
812 char *mb_hex = sha1_to_hex(mb);
813 char *bad_hex = sha1_to_hex(current_bad_sha1);
814 char *good_hex = join_sha1_array_hex(&good_revs, ' ');
815
816 fprintf(stderr, "Warning: the merge base between %s and [%s] "
817 "must be skipped.\n"
818 "So we cannot be sure the first bad commit is "
819 "between %s and %s.\n"
820 "We continue anyway.\n",
821 bad_hex, good_hex, mb_hex, bad_hex);
822 free(good_hex);
823 }
824
825 /*
826 * "check_merge_bases" checks that merge bases are not "bad".
827 *
828 * - If one is "bad", it means the user assumed something wrong
829 * and we must exit with a non 0 error code.
830 * - If one is "good", that's good, we have nothing to do.
831 * - If one is "skipped", we can't know but we should warn.
832 * - If we don't know, we should check it out and ask the user to test.
833 */
834 static void check_merge_bases(void)
835 {
836 struct commit_list *result;
837 int rev_nr;
838 struct commit **rev = get_bad_and_good_commits(&rev_nr);
839
840 result = get_merge_bases_many(rev[0], rev_nr - 1, rev + 1, 0);
841
842 for (; result; result = result->next) {
843 const unsigned char *mb = result->item->object.sha1;
844 if (!hashcmp(mb, current_bad_sha1)) {
845 handle_bad_merge_base();
846 } else if (0 <= lookup_sha1_array(&good_revs, mb)) {
847 continue;
848 } else if (0 <= lookup_sha1_array(&skipped_revs, mb)) {
849 handle_skipped_merge_base(mb);
850 } else {
851 printf("Bisecting: a merge base must be tested\n");
852 exit(bisect_checkout(sha1_to_hex(mb)));
853 }
854 }
855
856 free(rev);
857 free_commit_list(result);
858 }
859
2d938fc @chriscool bisect: check ancestors without forking a "git rev-list" process
chriscool authored
860 static int check_ancestors(const char *prefix)
d937d4a @chriscool bisect: add "check_good_are_ancestors_of_bad" function
chriscool authored
861 {
2d938fc @chriscool bisect: check ancestors without forking a "git rev-list" process
chriscool authored
862 struct rev_info revs;
863 struct object_array pending_copy;
864 int i, res;
d937d4a @chriscool bisect: add "check_good_are_ancestors_of_bad" function
chriscool authored
865
2d938fc @chriscool bisect: check ancestors without forking a "git rev-list" process
chriscool authored
866 bisect_rev_setup(&revs, prefix, "^%s", "%s", 0);
d937d4a @chriscool bisect: add "check_good_are_ancestors_of_bad" function
chriscool authored
867
2d938fc @chriscool bisect: check ancestors without forking a "git rev-list" process
chriscool authored
868 /* Save pending objects, so they can be cleaned up later. */
869 memset(&pending_copy, 0, sizeof(pending_copy));
870 for (i = 0; i < revs.pending.nr; i++)
871 add_object_array(revs.pending.objects[i].item,
872 revs.pending.objects[i].name,
873 &pending_copy);
874
875 bisect_common(&revs);
876 res = (revs.commits != NULL);
877
878 /* Clean up objects used, as they will be reused. */
879 for (i = 0; i < pending_copy.nr; i++) {
880 struct object *o = pending_copy.objects[i].item;
7a8e389 @chriscool bisect: drop unparse_commit() and use clear_commit_marks()
chriscool authored
881 clear_commit_marks((struct commit *)o, ALL_REV_FLAGS);
d937d4a @chriscool bisect: add "check_good_are_ancestors_of_bad" function
chriscool authored
882 }
883
2d938fc @chriscool bisect: check ancestors without forking a "git rev-list" process
chriscool authored
884 return res;
d937d4a @chriscool bisect: add "check_good_are_ancestors_of_bad" function
chriscool authored
885 }
886
887 /*
888 * "check_good_are_ancestors_of_bad" checks that all "good" revs are
889 * ancestor of the "bad" rev.
890 *
891 * If that's not the case, we need to check the merge bases.
892 * If a merge base must be tested by the user, its source code will be
893 * checked out to be tested by the user and we will exit.
894 */
895 static void check_good_are_ancestors_of_bad(const char *prefix)
896 {
897 const char *filename = git_path("BISECT_ANCESTORS_OK");
898 struct stat st;
899 int fd;
900
901 if (!current_bad_sha1)
902 die("a bad revision is needed");
903
904 /* Check if file BISECT_ANCESTORS_OK exists. */
905 if (!stat(filename, &st) && S_ISREG(st.st_mode))
906 return;
907
908 /* Bisecting with no good rev is ok. */
909 if (good_revs.sha1_nr == 0)
910 return;
911
2d938fc @chriscool bisect: check ancestors without forking a "git rev-list" process
chriscool authored
912 /* Check if all good revs are ancestor of the bad rev. */
913 if (check_ancestors(prefix))
d937d4a @chriscool bisect: add "check_good_are_ancestors_of_bad" function
chriscool authored
914 check_merge_bases();
915
916 /* Create file BISECT_ANCESTORS_OK. */
917 fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
918 if (fd < 0)
919 warning("could not create file '%s': %s",
920 filename, strerror(errno));
921 else
922 close(fd);
923 }
924
925 /*
e22278c @chriscool bisect: display first bad commit without forking a new process
chriscool authored
926 * This does "git diff-tree --pretty COMMIT" without one fork+exec.
927 */
928 static void show_diff_tree(const char *prefix, struct commit *commit)
929 {
930 struct rev_info opt;
931
932 /* diff-tree init */
933 init_revisions(&opt, prefix);
934 git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
935 opt.abbrev = 0;
936 opt.diff = 1;
937
938 /* This is what "--pretty" does */
939 opt.verbose_header = 1;
940 opt.use_terminator = 0;
941 opt.commit_format = CMIT_FMT_DEFAULT;
942
943 /* diff-tree init */
944 if (!opt.diffopt.output_format)
945 opt.diffopt.output_format = DIFF_FORMAT_RAW;
946
947 log_tree_commit(&opt, commit);
948 }
949
950 /*
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
951 * We use the convention that exiting with an exit code 10 means that
952 * the bisection process finished successfully.
953 * In this case the calling shell script should exit 0.
954 */
0871984 @chriscool bisect: make "git bisect" use new "--next-all" bisect-helper function
chriscool authored
955 int bisect_next_all(const char *prefix)
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
956 {
957 struct rev_info revs;
958 struct commit_list *tried;
6329bad @dripton bisect: fix singular/plural grammar nit
dripton authored
959 int reaches = 0, all = 0, nr, steps;
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
960 const unsigned char *bisect_rev;
961 char bisect_rev_hex[41];
962
2b02069 @chriscool bisect: remove too much function nesting
chriscool authored
963 if (read_bisect_refs())
964 die("reading bisect refs failed");
965
0871984 @chriscool bisect: make "git bisect" use new "--next-all" bisect-helper function
chriscool authored
966 check_good_are_ancestors_of_bad(prefix);
967
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
968 bisect_rev_setup(&revs, prefix, "%s", "^%s", 1);
969 revs.limited = 1;
2b02069 @chriscool bisect: remove too much function nesting
chriscool authored
970
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
971 bisect_common(&revs);
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
972
a22347c @chriscool bisect: rework some rev related functions to make them more reusable
chriscool authored
973 revs.commits = find_bisection(revs.commits, &reaches, &all,
974 !!skipped_revs.sha1_nr);
62d0b0d @chriscool bisect: when skipping, choose a commit away from a skipped commit
chriscool authored
975 revs.commits = managed_skipped(revs.commits, &tried);
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
976
977 if (!revs.commits) {
978 /*
979 * We should exit here only if the "bad"
980 * commit is also a "skip" commit.
981 */
982 exit_if_skipped_commits(tried, NULL);
983
984 printf("%s was both good and bad\n",
985 sha1_to_hex(current_bad_sha1));
986 exit(1);
987 }
988
989 bisect_rev = revs.commits->item->object.sha1;
990 memcpy(bisect_rev_hex, sha1_to_hex(bisect_rev), 41);
991
992 if (!hashcmp(bisect_rev, current_bad_sha1)) {
993 exit_if_skipped_commits(tried, current_bad_sha1);
21d0bc2 git-bisect: call the found commit "*the* first bad commit"
Nanako Shiraishi authored
994 printf("%s is the first bad commit\n", bisect_rev_hex);
e22278c @chriscool bisect: display first bad commit without forking a new process
chriscool authored
995 show_diff_tree(prefix, revs.commits->item);
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
996 /* This means the bisection process succeeded. */
997 exit(10);
998 }
999
1000 nr = all - reaches - 1;
6329bad @dripton bisect: fix singular/plural grammar nit
dripton authored
1001 steps = estimate_bisect_steps(all);
1002 printf("Bisecting: %d revision%s left to test after this "
1003 "(roughly %d step%s)\n", nr, (nr == 1 ? "" : "s"),
1004 steps, (steps == 1 ? "" : "s"));
ef24c7c @chriscool bisect--helper: add "--next-exit" to output bisect results
chriscool authored
1005
1006 return bisect_checkout(bisect_rev_hex);
1007 }
1008
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