7 #include "list-objects.h"
9 #include "sha1-lookup.h"
10 #include "run-command.h"
13 #include "oid-array.h"
14 #include "argv-array.h"
15 #include "commit-slab.h"
16 #include "commit-reach.h"
17 #include "object-store.h"
19 static struct oid_array good_revs;
20 static struct oid_array skipped_revs;
22 static struct object_id *current_bad_oid;
24 static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL};
25 static const char *argv_show_branch[] = {"show-branch", NULL, NULL};
27 static const char *term_bad;
28 static const char *term_good;
30 /* Remember to update object flag allocation in object.h */
31 #define COUNTED (1u<<16)
34 * This is a truly stupid algorithm, but it's only
35 * used for bisection, and we just don't care enough.
37 * We care just barely enough to avoid recursing for
40 static int count_distance(struct commit_list *entry)
45 struct commit *commit = entry->item;
46 struct commit_list *p;
48 if (commit->object.flags & (UNINTERESTING | COUNTED))
50 if (!(commit->object.flags & TREESAME))
52 commit->object.flags |= COUNTED;
58 nr += count_distance(p);
67 static void clear_distance(struct commit_list *list)
70 struct commit *commit = list->item;
71 commit->object.flags &= ~COUNTED;
76 define_commit_slab(commit_weight, int *);
77 static struct commit_weight commit_weight;
79 #define DEBUG_BISECT 0
81 static inline int weight(struct commit_list *elem)
83 return **commit_weight_at(&commit_weight, elem->item);
86 static inline void weight_set(struct commit_list *elem, int weight)
88 **commit_weight_at(&commit_weight, elem->item) = weight;
91 static int count_interesting_parents(struct commit *commit, int first_parent_only)
93 struct commit_list *p;
96 for (count = 0, p = commit->parents; p; p = p->next) {
97 if (!(p->item->object.flags & UNINTERESTING))
99 if (first_parent_only)
105 static inline int halfway(struct commit_list *p, int nr)
108 * Don't short-cut something we are not going to return!
110 if (p->item->object.flags & TREESAME)
115 * 2 and 3 are halfway of 5.
116 * 3 is halfway of 6 but 2 and 4 are not.
118 switch (2 * weight(p) - nr) {
119 case -1: case 0: case 1:
126 static void show_list(const char *debug, int counted, int nr,
127 struct commit_list *list)
129 struct commit_list *p;
134 fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
136 for (p = list; p; p = p->next) {
137 struct commit_list *pp;
138 struct commit *commit = p->item;
139 unsigned flags = commit->object.flags;
140 enum object_type type;
142 char *buf = read_object_file(&commit->object.oid, &type,
144 const char *subject_start;
147 fprintf(stderr, "%c%c%c ",
148 (flags & TREESAME) ? ' ' : 'T',
149 (flags & UNINTERESTING) ? 'U' : ' ',
150 (flags & COUNTED) ? 'C' : ' ');
151 if (*commit_weight_at(&commit_weight, p->item))
152 fprintf(stderr, "%3d", weight(p));
154 fprintf(stderr, "---");
155 fprintf(stderr, " %.*s", 8, oid_to_hex(&commit->object.oid));
156 for (pp = commit->parents; pp; pp = pp->next)
157 fprintf(stderr, " %.*s", 8,
158 oid_to_hex(&pp->item->object.oid));
160 subject_len = find_commit_subject(buf, &subject_start);
162 fprintf(stderr, " %.*s", subject_len, subject_start);
163 fprintf(stderr, "\n");
167 static struct commit_list *best_bisection(struct commit_list *list, int nr)
169 struct commit_list *p, *best;
170 int best_distance = -1;
173 for (p = list; p; p = p->next) {
175 unsigned flags = p->item->object.flags;
177 if (flags & TREESAME)
179 distance = weight(p);
180 if (nr - distance < distance)
181 distance = nr - distance;
182 if (distance > best_distance) {
184 best_distance = distance;
192 struct commit *commit;
196 static int compare_commit_dist(const void *a_, const void *b_)
198 struct commit_dist *a, *b;
200 a = (struct commit_dist *)a_;
201 b = (struct commit_dist *)b_;
202 if (a->distance != b->distance)
203 return b->distance - a->distance; /* desc sort */
204 return oidcmp(&a->commit->object.oid, &b->commit->object.oid);
207 static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr)
209 struct commit_list *p;
210 struct commit_dist *array = xcalloc(nr, sizeof(*array));
211 struct strbuf buf = STRBUF_INIT;
214 for (p = list, cnt = 0; p; p = p->next) {
216 unsigned flags = p->item->object.flags;
218 if (flags & TREESAME)
220 distance = weight(p);
221 if (nr - distance < distance)
222 distance = nr - distance;
223 array[cnt].commit = p->item;
224 array[cnt].distance = distance;
227 QSORT(array, cnt, compare_commit_dist);
228 for (p = list, i = 0; i < cnt; i++) {
229 struct object *obj = &(array[i].commit->object);
232 strbuf_addf(&buf, "dist=%d", array[i].distance);
233 add_name_decoration(DECORATION_NONE, buf.buf, obj);
235 p->item = array[i].commit;
240 free_commit_list(p->next);
243 strbuf_release(&buf);
249 * zero or positive weight is the number of interesting commits it can
250 * reach, including itself. Especially, weight = 0 means it does not
251 * reach any tree-changing commits (e.g. just above uninteresting one
252 * but traversal is with pathspec).
254 * weight = -1 means it has one parent and its distance is yet to
257 * weight = -2 means it has more than one parent and its distance is
258 * unknown. After running count_distance() first, they will get zero
259 * or positive distance.
261 static struct commit_list *do_find_bisection(struct commit_list *list,
262 int nr, int *weights,
263 int find_all, int first_parent_only)
266 struct commit_list *p;
270 for (n = 0, p = list; p; p = p->next) {
271 struct commit *commit = p->item;
272 unsigned flags = commit->object.flags;
274 *commit_weight_at(&commit_weight, p->item) = &weights[n++];
275 switch (count_interesting_parents(commit, first_parent_only)) {
277 if (!(flags & TREESAME)) {
280 show_list("bisection 2 count one",
284 * otherwise, it is known not to reach any
285 * tree-changing commit and gets weight 0.
297 show_list("bisection 2 initialize", counted, nr, list);
300 * If you have only one parent in the resulting set
301 * then you can reach one commit more than that parent
302 * can reach. So we do not have to run the expensive
303 * count_distance() for single strand of pearls.
305 * However, if you have more than one parents, you cannot
306 * just add their distance and one for yourself, since
307 * they usually reach the same ancestor and you would
308 * end up counting them twice that way.
310 * So we will first count distance of merges the usual
311 * way, and then fill the blanks using cheaper algorithm.
313 for (p = list; p; p = p->next) {
314 if (p->item->object.flags & UNINTERESTING)
318 if (first_parent_only)
319 BUG("shouldn't be calling count-distance in fp mode");
320 weight_set(p, count_distance(p));
321 clear_distance(list);
323 /* Does it happen to be at exactly half-way? */
324 if (!find_all && halfway(p, nr))
329 show_list("bisection 2 count_distance", counted, nr, list);
331 while (counted < nr) {
332 for (p = list; p; p = p->next) {
333 struct commit_list *q;
334 unsigned flags = p->item->object.flags;
339 for (q = p->item->parents;
341 q = first_parent_only ? NULL : q->next) {
342 if (q->item->object.flags & UNINTERESTING)
351 * weight for p is unknown but q is known.
352 * add one for p itself if p is to be counted,
353 * otherwise inherit it from q directly.
355 if (!(flags & TREESAME)) {
356 weight_set(p, weight(q)+1);
358 show_list("bisection 2 count one",
362 weight_set(p, weight(q));
364 /* Does it happen to be at exactly half-way? */
365 if (!find_all && halfway(p, nr))
370 show_list("bisection 2 counted all", counted, nr, list);
373 return best_bisection(list, nr);
375 return best_bisection_sorted(list, nr);
378 void find_bisection(struct commit_list **commit_list, int *reaches,
379 int *all, int find_all, int first_parent_only)
382 struct commit_list *list, *p, *best, *next, *last;
385 show_list("bisection 2 entry", 0, 0, *commit_list);
386 init_commit_weight(&commit_weight);
389 * Count the number of total and tree-changing items on the
390 * list, while reversing the list.
392 for (nr = on_list = 0, last = NULL, p = *commit_list;
395 unsigned flags = p->item->object.flags;
398 if (flags & UNINTERESTING) {
404 if (!(flags & TREESAME))
409 show_list("bisection 2 sorted", 0, nr, list);
412 weights = xcalloc(on_list, sizeof(*weights));
414 /* Do the real work of finding bisection commit. */
415 best = do_find_bisection(list, nr, weights, find_all, first_parent_only);
418 list->item = best->item;
419 free_commit_list(list->next);
423 *reaches = weight(best);
427 clear_commit_weight(&commit_weight);
430 static int register_ref(const char *refname, const struct object_id *oid,
431 int flags, void *cb_data)
433 struct strbuf good_prefix = STRBUF_INIT;
434 strbuf_addstr(&good_prefix, term_good);
435 strbuf_addstr(&good_prefix, "-");
437 if (!strcmp(refname, term_bad)) {
438 current_bad_oid = xmalloc(sizeof(*current_bad_oid));
439 oidcpy(current_bad_oid, oid);
440 } else if (starts_with(refname, good_prefix.buf)) {
441 oid_array_append(&good_revs, oid);
442 } else if (starts_with(refname, "skip-")) {
443 oid_array_append(&skipped_revs, oid);
446 strbuf_release(&good_prefix);
451 static int read_bisect_refs(void)
453 return for_each_ref_in("refs/bisect/", register_ref, NULL);
456 static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
457 static GIT_PATH_FUNC(git_path_bisect_expected_rev, "BISECT_EXPECTED_REV")
458 static GIT_PATH_FUNC(git_path_bisect_ancestors_ok, "BISECT_ANCESTORS_OK")
459 static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN")
460 static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START")
461 static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG")
462 static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS")
463 static GIT_PATH_FUNC(git_path_head_name, "head-name")
465 static void read_bisect_paths(struct argv_array *array)
467 struct strbuf str = STRBUF_INIT;
468 const char *filename = git_path_bisect_names();
469 FILE *fp = xfopen(filename, "r");
471 while (strbuf_getline_lf(&str, fp) != EOF) {
473 if (sq_dequote_to_argv_array(str.buf, array))
474 die(_("Badly quoted content in file '%s': %s"),
478 strbuf_release(&str);
482 static char *join_oid_array_hex(struct oid_array *array, char delim)
484 struct strbuf joined_hexs = STRBUF_INIT;
487 for (i = 0; i < array->nr; i++) {
488 strbuf_addstr(&joined_hexs, oid_to_hex(array->oid + i));
489 if (i + 1 < array->nr)
490 strbuf_addch(&joined_hexs, delim);
493 return strbuf_detach(&joined_hexs, NULL);
497 * In this function, passing a not NULL skipped_first is very special.
498 * It means that we want to know if the first commit in the list is
499 * skipped because we will want to test a commit away from it if it is
501 * So if the first commit is skipped, we cannot take the shortcut to
502 * just "return list" when we find the first non skipped commit, we
503 * have to return a fully filtered list.
505 * We use (*skipped_first == -1) to mean "it has been found that the
506 * first commit is not skipped". In this case *skipped_first is set back
507 * to 0 just before the function returns.
509 struct commit_list *filter_skipped(struct commit_list *list,
510 struct commit_list **tried,
515 struct commit_list *filtered = NULL, **f = &filtered;
524 if (!skipped_revs.nr)
528 struct commit_list *next = list->next;
530 if (0 <= oid_array_lookup(&skipped_revs, &list->item->object.oid)) {
531 if (skipped_first && !*skipped_first)
533 /* Move current to tried list */
538 if (!skipped_first || !*skipped_first)
540 } else if (skipped_first && !*skipped_first) {
541 /* This means we know it's not skipped */
544 /* Move current to filtered list */
553 if (skipped_first && *skipped_first == -1)
559 #define PRN_MODULO 32768
562 * This is a pseudo random number generator based on "man 3 rand".
563 * It is not used properly because the seed is the argument and it
564 * is increased by one between each call, but that should not matter
565 * for this application.
567 static unsigned get_prn(unsigned count)
569 count = count * 1103515245 + 12345;
570 return (count/65536) % PRN_MODULO;
574 * Custom integer square root from
575 * https://en.wikipedia.org/wiki/Integer_square_root
577 static int sqrti(int val)
585 float y = (x + (float)val / x) / 2;
586 d = (y > x) ? y - x : x - y;
593 static struct commit_list *skip_away(struct commit_list *list, int count)
595 struct commit_list *cur, *previous;
598 prn = get_prn(count);
599 index = (count * prn / PRN_MODULO) * sqrti(prn) / sqrti(PRN_MODULO);
604 for (i = 0; cur; cur = cur->next, i++) {
606 if (!oideq(&cur->item->object.oid, current_bad_oid))
618 static struct commit_list *managed_skipped(struct commit_list *list,
619 struct commit_list **tried)
621 int count, skipped_first;
625 if (!skipped_revs.nr)
628 list = filter_skipped(list, tried, 0, &count, &skipped_first);
633 return skip_away(list, count);
636 static void bisect_rev_setup(struct repository *r, struct rev_info *revs,
638 const char *bad_format, const char *good_format,
641 struct argv_array rev_argv = ARGV_ARRAY_INIT;
644 repo_init_revisions(r, revs, prefix);
646 revs->commit_format = CMIT_FMT_UNSPECIFIED;
648 /* rev_argv.argv[0] will be ignored by setup_revisions */
649 argv_array_push(&rev_argv, "bisect_rev_setup");
650 argv_array_pushf(&rev_argv, bad_format, oid_to_hex(current_bad_oid));
651 for (i = 0; i < good_revs.nr; i++)
652 argv_array_pushf(&rev_argv, good_format,
653 oid_to_hex(good_revs.oid + i));
654 argv_array_push(&rev_argv, "--");
656 read_bisect_paths(&rev_argv);
658 setup_revisions(rev_argv.argc, rev_argv.argv, revs, NULL);
659 /* XXX leak rev_argv, as "revs" may still be pointing to it */
662 static void bisect_common(struct rev_info *revs)
664 if (prepare_revision_walk(revs))
665 die("revision walk setup failed");
666 if (revs->tree_objects)
667 mark_edges_uninteresting(revs, NULL, 0);
670 static enum bisect_error error_if_skipped_commits(struct commit_list *tried,
671 const struct object_id *bad)
676 printf("There are only 'skip'ped commits left to test.\n"
677 "The first %s commit could be any of:\n", term_bad);
679 for ( ; tried; tried = tried->next)
680 printf("%s\n", oid_to_hex(&tried->item->object.oid));
683 printf("%s\n", oid_to_hex(bad));
684 printf(_("We cannot bisect more!\n"));
686 return BISECT_ONLY_SKIPPED_LEFT;
689 static int is_expected_rev(const struct object_id *oid)
691 const char *filename = git_path_bisect_expected_rev();
693 struct strbuf str = STRBUF_INIT;
697 if (stat(filename, &st) || !S_ISREG(st.st_mode))
700 fp = fopen_or_warn(filename, "r");
704 if (strbuf_getline_lf(&str, fp) != EOF)
705 res = !strcmp(str.buf, oid_to_hex(oid));
707 strbuf_release(&str);
713 static enum bisect_error bisect_checkout(const struct object_id *bisect_rev, int no_checkout)
715 char bisect_rev_hex[GIT_MAX_HEXSZ + 1];
716 enum bisect_error res = BISECT_OK;
718 memcpy(bisect_rev_hex, oid_to_hex(bisect_rev), the_hash_algo->hexsz + 1);
719 update_ref(NULL, "BISECT_EXPECTED_REV", bisect_rev, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
721 argv_checkout[2] = bisect_rev_hex;
723 update_ref(NULL, "BISECT_HEAD", bisect_rev, NULL, 0,
724 UPDATE_REFS_DIE_ON_ERR);
726 res = run_command_v_opt(argv_checkout, RUN_GIT_CMD);
729 * Errors in `run_command()` itself, signaled by res < 0,
730 * and errors in the child process, signaled by res > 0
731 * can both be treated as regular BISECT_FAILURE (-1).
736 argv_show_branch[1] = bisect_rev_hex;
737 res = run_command_v_opt(argv_show_branch, RUN_GIT_CMD);
739 * Errors in `run_command()` itself, signaled by res < 0,
740 * and errors in the child process, signaled by res > 0
741 * can both be treated as regular BISECT_FAILURE (-1).
746 static struct commit *get_commit_reference(struct repository *r,
747 const struct object_id *oid)
749 struct commit *c = lookup_commit_reference(r, oid);
751 die(_("Not a valid commit name %s"), oid_to_hex(oid));
755 static struct commit **get_bad_and_good_commits(struct repository *r,
761 ALLOC_ARRAY(rev, 1 + good_revs.nr);
762 rev[n++] = get_commit_reference(r, current_bad_oid);
763 for (i = 0; i < good_revs.nr; i++)
764 rev[n++] = get_commit_reference(r, good_revs.oid + i);
770 static enum bisect_error handle_bad_merge_base(void)
772 if (is_expected_rev(current_bad_oid)) {
773 char *bad_hex = oid_to_hex(current_bad_oid);
774 char *good_hex = join_oid_array_hex(&good_revs, ' ');
775 if (!strcmp(term_bad, "bad") && !strcmp(term_good, "good")) {
776 fprintf(stderr, _("The merge base %s is bad.\n"
777 "This means the bug has been fixed "
778 "between %s and [%s].\n"),
779 bad_hex, bad_hex, good_hex);
780 } else if (!strcmp(term_bad, "new") && !strcmp(term_good, "old")) {
781 fprintf(stderr, _("The merge base %s is new.\n"
782 "The property has changed "
783 "between %s and [%s].\n"),
784 bad_hex, bad_hex, good_hex);
786 fprintf(stderr, _("The merge base %s is %s.\n"
787 "This means the first '%s' commit is "
788 "between %s and [%s].\n"),
789 bad_hex, term_bad, term_good, bad_hex, good_hex);
791 return BISECT_MERGE_BASE_CHECK;
794 fprintf(stderr, _("Some %s revs are not ancestors of the %s rev.\n"
795 "git bisect cannot work properly in this case.\n"
796 "Maybe you mistook %s and %s revs?\n"),
797 term_good, term_bad, term_good, term_bad);
798 return BISECT_FAILED;
801 static void handle_skipped_merge_base(const struct object_id *mb)
803 char *mb_hex = oid_to_hex(mb);
804 char *bad_hex = oid_to_hex(current_bad_oid);
805 char *good_hex = join_oid_array_hex(&good_revs, ' ');
807 warning(_("the merge base between %s and [%s] "
809 "So we cannot be sure the first %s commit is "
810 "between %s and %s.\n"
811 "We continue anyway."),
812 bad_hex, good_hex, term_bad, mb_hex, bad_hex);
817 * "check_merge_bases" checks that merge bases are not "bad" (or "new").
819 * - If one is "bad" (or "new"), it means the user assumed something wrong
820 * and we must return error with a non 0 error code.
821 * - If one is "good" (or "old"), that's good, we have nothing to do.
822 * - If one is "skipped", we can't know but we should warn.
823 * - If we don't know, we should check it out and ask the user to test.
824 * - If a merge base must be tested, on success return
825 * BISECT_INTERNAL_SUCCESS_MERGE_BASE (-11) a special condition
826 * for early success, this will be converted back to 0 in
827 * check_good_are_ancestors_of_bad().
829 static enum bisect_error check_merge_bases(int rev_nr, struct commit **rev, int no_checkout)
831 enum bisect_error res = BISECT_OK;
832 struct commit_list *result;
834 result = get_merge_bases_many(rev[0], rev_nr - 1, rev + 1);
836 for (; result; result = result->next) {
837 const struct object_id *mb = &result->item->object.oid;
838 if (oideq(mb, current_bad_oid)) {
839 res = handle_bad_merge_base();
841 } else if (0 <= oid_array_lookup(&good_revs, mb)) {
843 } else if (0 <= oid_array_lookup(&skipped_revs, mb)) {
844 handle_skipped_merge_base(mb);
846 printf(_("Bisecting: a merge base must be tested\n"));
847 res = bisect_checkout(mb, no_checkout);
849 /* indicate early success */
850 res = BISECT_INTERNAL_SUCCESS_MERGE_BASE;
855 free_commit_list(result);
859 static int check_ancestors(struct repository *r, int rev_nr,
860 struct commit **rev, const char *prefix)
862 struct rev_info revs;
865 bisect_rev_setup(r, &revs, prefix, "^%s", "%s", 0);
867 bisect_common(&revs);
868 res = (revs.commits != NULL);
870 /* Clean up objects used, as they will be reused. */
871 clear_commit_marks_many(rev_nr, rev, ALL_REV_FLAGS);
877 * "check_good_are_ancestors_of_bad" checks that all "good" revs are
878 * ancestor of the "bad" rev.
880 * If that's not the case, we need to check the merge bases.
881 * If a merge base must be tested by the user, its source code will be
882 * checked out to be tested by the user and we will return.
885 static enum bisect_error check_good_are_ancestors_of_bad(struct repository *r,
892 enum bisect_error res = BISECT_OK;
895 if (!current_bad_oid)
896 return error(_("a %s revision is needed"), term_bad);
898 filename = git_pathdup("BISECT_ANCESTORS_OK");
900 /* Check if file BISECT_ANCESTORS_OK exists. */
901 if (!stat(filename, &st) && S_ISREG(st.st_mode))
904 /* Bisecting with no good rev is ok. */
908 /* Check if all good revs are ancestor of the bad rev. */
910 rev = get_bad_and_good_commits(r, &rev_nr);
911 if (check_ancestors(r, rev_nr, rev, prefix))
912 res = check_merge_bases(rev_nr, rev, no_checkout);
916 /* Create file BISECT_ANCESTORS_OK. */
917 fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600);
920 * BISECT_ANCESTORS_OK file is not absolutely necessary,
921 * the bisection process will continue at the next
923 * So, just signal with a warning that something
926 warning_errno(_("could not create file '%s'"),
937 * This does "git diff-tree --pretty COMMIT" without one fork+exec.
939 static void show_diff_tree(struct repository *r,
941 struct commit *commit)
943 const char *argv[] = {
944 "diff-tree", "--pretty", "--stat", "--summary", "--cc", NULL
948 git_config(git_diff_ui_config, NULL);
949 repo_init_revisions(r, &opt, prefix);
951 setup_revisions(ARRAY_SIZE(argv) - 1, argv, &opt, NULL);
952 log_tree_commit(&opt, commit);
956 * The terms used for this bisect session are stored in BISECT_TERMS.
957 * We read them and store them to adapt the messages accordingly.
958 * Default is bad/good.
960 void read_bisect_terms(const char **read_bad, const char **read_good)
962 struct strbuf str = STRBUF_INIT;
963 const char *filename = git_path_bisect_terms();
964 FILE *fp = fopen(filename, "r");
967 if (errno == ENOENT) {
972 die_errno(_("could not read file '%s'"), filename);
975 strbuf_getline_lf(&str, fp);
976 *read_bad = strbuf_detach(&str, NULL);
977 strbuf_getline_lf(&str, fp);
978 *read_good = strbuf_detach(&str, NULL);
980 strbuf_release(&str);
985 * We use the convention that return BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND (-10) means
986 * the bisection process finished successfully.
987 * In this case the calling function or command should not turn a
988 * BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND return code into an error or a non zero exit code.
989 * If no_checkout is non-zero, the bisection process does not
990 * checkout the trial commit but instead simply updates BISECT_HEAD.
992 enum bisect_error bisect_next_all(struct repository *r, const char *prefix, int no_checkout)
994 struct rev_info revs;
995 struct commit_list *tried;
996 int reaches = 0, all = 0, nr, steps;
997 enum bisect_error res = BISECT_OK;
998 struct object_id *bisect_rev;
1000 int first_parent_only = 0; /* TODO: pass --first-parent flag from git bisect start */
1002 read_bisect_terms(&term_bad, &term_good);
1003 if (read_bisect_refs())
1004 die(_("reading bisect refs failed"));
1006 res = check_good_are_ancestors_of_bad(r, prefix, no_checkout);
1010 bisect_rev_setup(r, &revs, prefix, "%s", "^%s", 1);
1011 revs.first_parent_only = first_parent_only;
1014 bisect_common(&revs);
1016 find_bisection(&revs.commits, &reaches, &all, !!skipped_revs.nr, first_parent_only);
1017 revs.commits = managed_skipped(revs.commits, &tried);
1019 if (!revs.commits) {
1021 * We should return error here only if the "bad"
1022 * commit is also a "skip" commit.
1024 res = error_if_skipped_commits(tried, NULL);
1027 printf(_("%s was both %s and %s\n"),
1028 oid_to_hex(current_bad_oid),
1032 return BISECT_FAILED;
1036 fprintf(stderr, _("No testable commit found.\n"
1037 "Maybe you started with bad path parameters?\n"));
1039 return BISECT_NO_TESTABLE_COMMIT;
1042 bisect_rev = &revs.commits->item->object.oid;
1044 if (oideq(bisect_rev, current_bad_oid)) {
1045 res = error_if_skipped_commits(tried, current_bad_oid);
1048 printf("%s is the first %s commit\n", oid_to_hex(bisect_rev),
1051 show_diff_tree(r, prefix, revs.commits->item);
1053 * This means the bisection process succeeded.
1054 * Using BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND (-10)
1055 * so that the call chain can simply check
1056 * for negative return values for early returns up
1057 * until the cmd_bisect__helper() caller.
1059 return BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND;
1062 nr = all - reaches - 1;
1063 steps = estimate_bisect_steps(all);
1065 steps_msg = xstrfmt(Q_("(roughly %d step)", "(roughly %d steps)",
1068 * TRANSLATORS: the last %s will be replaced with "(roughly %d
1069 * steps)" translation.
1071 printf(Q_("Bisecting: %d revision left to test after this %s\n",
1072 "Bisecting: %d revisions left to test after this %s\n",
1073 nr), nr, steps_msg);
1076 return bisect_checkout(bisect_rev, no_checkout);
1079 static inline int log2i(int n)
1083 for (; n > 1; n >>= 1)
1089 static inline int exp2i(int n)
1095 * Estimate the number of bisect steps left (after the current step)
1097 * For any x between 0 included and 2^n excluded, the probability for
1098 * n - 1 steps left looks like:
1100 * P(2^n + x) == (2^n - x) / (2^n + x)
1102 * and P(2^n + x) < 0.5 means 2^n < 3x
1104 int estimate_bisect_steps(int all)
1115 return (e < 3 * x) ? n : n - 1;
1118 static int mark_for_removal(const char *refname, const struct object_id *oid,
1119 int flag, void *cb_data)
1121 struct string_list *refs = cb_data;
1122 char *ref = xstrfmt("refs/bisect%s", refname);
1123 string_list_append(refs, ref);
1127 int bisect_clean_state(void)
1131 /* There may be some refs packed during bisection */
1132 struct string_list refs_for_removal = STRING_LIST_INIT_NODUP;
1133 for_each_ref_in("refs/bisect", mark_for_removal, (void *) &refs_for_removal);
1134 string_list_append(&refs_for_removal, xstrdup("BISECT_HEAD"));
1135 result = delete_refs("bisect: remove", &refs_for_removal, REF_NO_DEREF);
1136 refs_for_removal.strdup_strings = 1;
1137 string_list_clear(&refs_for_removal, 0);
1138 unlink_or_warn(git_path_bisect_expected_rev());
1139 unlink_or_warn(git_path_bisect_ancestors_ok());
1140 unlink_or_warn(git_path_bisect_log());
1141 unlink_or_warn(git_path_bisect_names());
1142 unlink_or_warn(git_path_bisect_run());
1143 unlink_or_warn(git_path_bisect_terms());
1144 /* Cleanup head-name if it got left by an old version of git-bisect */
1145 unlink_or_warn(git_path_head_name());
1147 * Cleanup BISECT_START last to support the --no-checkout option
1148 * introduced in the commit 4796e823a.
1150 unlink_or_warn(git_path_bisect_start());