| #include "cache.h" |
| #include "commit.h" |
| #include "diff.h" |
| #include "revision.h" |
| #include "refs.h" |
| #include "list-objects.h" |
| #include "quote.h" |
| #include "sha1-lookup.h" |
| #include "run-command.h" |
| #include "log-tree.h" |
| #include "bisect.h" |
| #include "sha1-array.h" |
| #include "argv-array.h" |
| |
| static struct sha1_array good_revs; |
| static struct sha1_array skipped_revs; |
| |
| static const unsigned char *current_bad_sha1; |
| |
| static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL}; |
| static const char *argv_show_branch[] = {"show-branch", NULL, NULL}; |
| static const char *argv_update_ref[] = {"update-ref", "--no-deref", "BISECT_HEAD", NULL, NULL}; |
| |
| /* bits #0-15 in revision.h */ |
| |
| #define COUNTED (1u<<16) |
| |
| /* |
| * This is a truly stupid algorithm, but it's only |
| * used for bisection, and we just don't care enough. |
| * |
| * We care just barely enough to avoid recursing for |
| * non-merge entries. |
| */ |
| static int count_distance(struct commit_list *entry) |
| { |
| int nr = 0; |
| |
| while (entry) { |
| struct commit *commit = entry->item; |
| struct commit_list *p; |
| |
| if (commit->object.flags & (UNINTERESTING | COUNTED)) |
| break; |
| if (!(commit->object.flags & TREESAME)) |
| nr++; |
| commit->object.flags |= COUNTED; |
| p = commit->parents; |
| entry = p; |
| if (p) { |
| p = p->next; |
| while (p) { |
| nr += count_distance(p); |
| p = p->next; |
| } |
| } |
| } |
| |
| return nr; |
| } |
| |
| static void clear_distance(struct commit_list *list) |
| { |
| while (list) { |
| struct commit *commit = list->item; |
| commit->object.flags &= ~COUNTED; |
| list = list->next; |
| } |
| } |
| |
| #define DEBUG_BISECT 0 |
| |
| static inline int weight(struct commit_list *elem) |
| { |
| return *((int*)(elem->item->util)); |
| } |
| |
| static inline void weight_set(struct commit_list *elem, int weight) |
| { |
| *((int*)(elem->item->util)) = weight; |
| } |
| |
| static int count_interesting_parents(struct commit *commit) |
| { |
| struct commit_list *p; |
| int count; |
| |
| for (count = 0, p = commit->parents; p; p = p->next) { |
| if (p->item->object.flags & UNINTERESTING) |
| continue; |
| count++; |
| } |
| return count; |
| } |
| |
| static inline int halfway(struct commit_list *p, int nr) |
| { |
| /* |
| * Don't short-cut something we are not going to return! |
| */ |
| if (p->item->object.flags & TREESAME) |
| return 0; |
| if (DEBUG_BISECT) |
| return 0; |
| /* |
| * 2 and 3 are halfway of 5. |
| * 3 is halfway of 6 but 2 and 4 are not. |
| */ |
| switch (2 * weight(p) - nr) { |
| case -1: case 0: case 1: |
| return 1; |
| default: |
| return 0; |
| } |
| } |
| |
| #if !DEBUG_BISECT |
| #define show_list(a,b,c,d) do { ; } while (0) |
| #else |
| static void show_list(const char *debug, int counted, int nr, |
| struct commit_list *list) |
| { |
| struct commit_list *p; |
| |
| fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr); |
| |
| for (p = list; p; p = p->next) { |
| struct commit_list *pp; |
| struct commit *commit = p->item; |
| unsigned flags = commit->object.flags; |
| enum object_type type; |
| unsigned long size; |
| char *buf = read_sha1_file(commit->object.sha1, &type, &size); |
| const char *subject_start; |
| int subject_len; |
| |
| fprintf(stderr, "%c%c%c ", |
| (flags & TREESAME) ? ' ' : 'T', |
| (flags & UNINTERESTING) ? 'U' : ' ', |
| (flags & COUNTED) ? 'C' : ' '); |
| if (commit->util) |
| fprintf(stderr, "%3d", weight(p)); |
| else |
| fprintf(stderr, "---"); |
| fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1)); |
| for (pp = commit->parents; pp; pp = pp->next) |
| fprintf(stderr, " %.*s", 8, |
| sha1_to_hex(pp->item->object.sha1)); |
| |
| subject_len = find_commit_subject(buf, &subject_start); |
| if (subject_len) |
| fprintf(stderr, " %.*s", subject_len, subject_start); |
| fprintf(stderr, "\n"); |
| } |
| } |
| #endif /* DEBUG_BISECT */ |
| |
| static struct commit_list *best_bisection(struct commit_list *list, int nr) |
| { |
| struct commit_list *p, *best; |
| int best_distance = -1; |
| |
| best = list; |
| for (p = list; p; p = p->next) { |
| int distance; |
| unsigned flags = p->item->object.flags; |
| |
| if (flags & TREESAME) |
| continue; |
| distance = weight(p); |
| if (nr - distance < distance) |
| distance = nr - distance; |
| if (distance > best_distance) { |
| best = p; |
| best_distance = distance; |
| } |
| } |
| |
| return best; |
| } |
| |
| struct commit_dist { |
| struct commit *commit; |
| int distance; |
| }; |
| |
| static int compare_commit_dist(const void *a_, const void *b_) |
| { |
| struct commit_dist *a, *b; |
| |
| a = (struct commit_dist *)a_; |
| b = (struct commit_dist *)b_; |
| if (a->distance != b->distance) |
| return b->distance - a->distance; /* desc sort */ |
| return hashcmp(a->commit->object.sha1, b->commit->object.sha1); |
| } |
| |
| static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr) |
| { |
| struct commit_list *p; |
| struct commit_dist *array = xcalloc(nr, sizeof(*array)); |
| int cnt, i; |
| |
| for (p = list, cnt = 0; p; p = p->next) { |
| int distance; |
| unsigned flags = p->item->object.flags; |
| |
| if (flags & TREESAME) |
| continue; |
| distance = weight(p); |
| if (nr - distance < distance) |
| distance = nr - distance; |
| array[cnt].commit = p->item; |
| array[cnt].distance = distance; |
| cnt++; |
| } |
| qsort(array, cnt, sizeof(*array), compare_commit_dist); |
| for (p = list, i = 0; i < cnt; i++) { |
| struct name_decoration *r = xmalloc(sizeof(*r) + 100); |
| struct object *obj = &(array[i].commit->object); |
| |
| sprintf(r->name, "dist=%d", array[i].distance); |
| r->next = add_decoration(&name_decoration, obj, r); |
| p->item = array[i].commit; |
| p = p->next; |
| } |
| if (p) |
| p->next = NULL; |
| free(array); |
| return list; |
| } |
| |
| /* |
| * zero or positive weight is the number of interesting commits it can |
| * reach, including itself. Especially, weight = 0 means it does not |
| * reach any tree-changing commits (e.g. just above uninteresting one |
| * but traversal is with pathspec). |
| * |
| * weight = -1 means it has one parent and its distance is yet to |
| * be computed. |
| * |
| * weight = -2 means it has more than one parent and its distance is |
| * unknown. After running count_distance() first, they will get zero |
| * or positive distance. |
| */ |
| static struct commit_list *do_find_bisection(struct commit_list *list, |
| int nr, int *weights, |
| int find_all) |
| { |
| int n, counted; |
| struct commit_list *p; |
| |
| counted = 0; |
| |
| for (n = 0, p = list; p; p = p->next) { |
| struct commit *commit = p->item; |
| unsigned flags = commit->object.flags; |
| |
| p->item->util = &weights[n++]; |
| switch (count_interesting_parents(commit)) { |
| case 0: |
| if (!(flags & TREESAME)) { |
| weight_set(p, 1); |
| counted++; |
| show_list("bisection 2 count one", |
| counted, nr, list); |
| } |
| /* |
| * otherwise, it is known not to reach any |
| * tree-changing commit and gets weight 0. |
| */ |
| break; |
| case 1: |
| weight_set(p, -1); |
| break; |
| default: |
| weight_set(p, -2); |
| break; |
| } |
| } |
| |
| show_list("bisection 2 initialize", counted, nr, list); |
| |
| /* |
| * If you have only one parent in the resulting set |
| * then you can reach one commit more than that parent |
| * can reach. So we do not have to run the expensive |
| * count_distance() for single strand of pearls. |
| * |
| * However, if you have more than one parents, you cannot |
| * just add their distance and one for yourself, since |
| * they usually reach the same ancestor and you would |
| * end up counting them twice that way. |
| * |
| * So we will first count distance of merges the usual |
| * way, and then fill the blanks using cheaper algorithm. |
| */ |
| for (p = list; p; p = p->next) { |
| if (p->item->object.flags & UNINTERESTING) |
| continue; |
| if (weight(p) != -2) |
| continue; |
| weight_set(p, count_distance(p)); |
| clear_distance(list); |
| |
| /* Does it happen to be at exactly half-way? */ |
| if (!find_all && halfway(p, nr)) |
| return p; |
| counted++; |
| } |
| |
| show_list("bisection 2 count_distance", counted, nr, list); |
| |
| while (counted < nr) { |
| for (p = list; p; p = p->next) { |
| struct commit_list *q; |
| unsigned flags = p->item->object.flags; |
| |
| if (0 <= weight(p)) |
| continue; |
| for (q = p->item->parents; q; q = q->next) { |
| if (q->item->object.flags & UNINTERESTING) |
| continue; |
| if (0 <= weight(q)) |
| break; |
| } |
| if (!q) |
| continue; |
| |
| /* |
| * weight for p is unknown but q is known. |
| * add one for p itself if p is to be counted, |
| * otherwise inherit it from q directly. |
| */ |
| if (!(flags & TREESAME)) { |
| weight_set(p, weight(q)+1); |
| counted++; |
| show_list("bisection 2 count one", |
| counted, nr, list); |
| } |
| else |
| weight_set(p, weight(q)); |
| |
| /* Does it happen to be at exactly half-way? */ |
| if (!find_all && halfway(p, nr)) |
| return p; |
| } |
| } |
| |
| show_list("bisection 2 counted all", counted, nr, list); |
| |
| if (!find_all) |
| return best_bisection(list, nr); |
| else |
| return best_bisection_sorted(list, nr); |
| } |
| |
| struct commit_list *find_bisection(struct commit_list *list, |
| int *reaches, int *all, |
| int find_all) |
| { |
| int nr, on_list; |
| struct commit_list *p, *best, *next, *last; |
| int *weights; |
| |
| show_list("bisection 2 entry", 0, 0, list); |
| |
| /* |
| * Count the number of total and tree-changing items on the |
| * list, while reversing the list. |
| */ |
| for (nr = on_list = 0, last = NULL, p = list; |
| p; |
| p = next) { |
| unsigned flags = p->item->object.flags; |
| |
| next = p->next; |
| if (flags & UNINTERESTING) |
| continue; |
| p->next = last; |
| last = p; |
| if (!(flags & TREESAME)) |
| nr++; |
| on_list++; |
| } |
| list = last; |
| show_list("bisection 2 sorted", 0, nr, list); |
| |
| *all = nr; |
| weights = xcalloc(on_list, sizeof(*weights)); |
| |
| /* Do the real work of finding bisection commit. */ |
| best = do_find_bisection(list, nr, weights, find_all); |
| if (best) { |
| if (!find_all) |
| best->next = NULL; |
| *reaches = weight(best); |
| } |
| free(weights); |
| return best; |
| } |
| |
| static int register_ref(const char *refname, const unsigned char *sha1, |
| int flags, void *cb_data) |
| { |
| if (!strcmp(refname, "bad")) { |
| current_bad_sha1 = sha1; |
| } else if (!prefixcmp(refname, "good-")) { |
| sha1_array_append(&good_revs, sha1); |
| } else if (!prefixcmp(refname, "skip-")) { |
| sha1_array_append(&skipped_revs, sha1); |
| } |
| |
| return 0; |
| } |
| |
| static int read_bisect_refs(void) |
| { |
| return for_each_ref_in("refs/bisect/", register_ref, NULL); |
| } |
| |
| static void read_bisect_paths(struct argv_array *array) |
| { |
| struct strbuf str = STRBUF_INIT; |
| const char *filename = git_path("BISECT_NAMES"); |
| FILE *fp = fopen(filename, "r"); |
| |
| if (!fp) |
| die_errno("Could not open file '%s'", filename); |
| |
| while (strbuf_getline(&str, fp, '\n') != EOF) { |
| strbuf_trim(&str); |
| if (sq_dequote_to_argv_array(str.buf, array)) |
| die("Badly quoted content in file '%s': %s", |
| filename, str.buf); |
| } |
| |
| strbuf_release(&str); |
| fclose(fp); |
| } |
| |
| static char *join_sha1_array_hex(struct sha1_array *array, char delim) |
| { |
| struct strbuf joined_hexs = STRBUF_INIT; |
| int i; |
| |
| for (i = 0; i < array->nr; i++) { |
| strbuf_addstr(&joined_hexs, sha1_to_hex(array->sha1[i])); |
| if (i + 1 < array->nr) |
| strbuf_addch(&joined_hexs, delim); |
| } |
| |
| return strbuf_detach(&joined_hexs, NULL); |
| } |
| |
| /* |
| * In this function, passing a not NULL skipped_first is very special. |
| * It means that we want to know if the first commit in the list is |
| * skipped because we will want to test a commit away from it if it is |
| * indeed skipped. |
| * So if the first commit is skipped, we cannot take the shortcut to |
| * just "return list" when we find the first non skipped commit, we |
| * have to return a fully filtered list. |
| * |
| * We use (*skipped_first == -1) to mean "it has been found that the |
| * first commit is not skipped". In this case *skipped_first is set back |
| * to 0 just before the function returns. |
| */ |
| struct commit_list *filter_skipped(struct commit_list *list, |
| struct commit_list **tried, |
| int show_all, |
| int *count, |
| int *skipped_first) |
| { |
| struct commit_list *filtered = NULL, **f = &filtered; |
| |
| *tried = NULL; |
| |
| if (skipped_first) |
| *skipped_first = 0; |
| if (count) |
| *count = 0; |
| |
| if (!skipped_revs.nr) |
| return list; |
| |
| while (list) { |
| struct commit_list *next = list->next; |
| list->next = NULL; |
| if (0 <= sha1_array_lookup(&skipped_revs, |
| list->item->object.sha1)) { |
| if (skipped_first && !*skipped_first) |
| *skipped_first = 1; |
| /* Move current to tried list */ |
| *tried = list; |
| tried = &list->next; |
| } else { |
| if (!show_all) { |
| if (!skipped_first || !*skipped_first) |
| return list; |
| } else if (skipped_first && !*skipped_first) { |
| /* This means we know it's not skipped */ |
| *skipped_first = -1; |
| } |
| /* Move current to filtered list */ |
| *f = list; |
| f = &list->next; |
| if (count) |
| (*count)++; |
| } |
| list = next; |
| } |
| |
| if (skipped_first && *skipped_first == -1) |
| *skipped_first = 0; |
| |
| return filtered; |
| } |
| |
| #define PRN_MODULO 32768 |
| |
| /* |
| * This is a pseudo random number generator based on "man 3 rand". |
| * It is not used properly because the seed is the argument and it |
| * is increased by one between each call, but that should not matter |
| * for this application. |
| */ |
| static int get_prn(int count) { |
| count = count * 1103515245 + 12345; |
| return ((unsigned)(count/65536) % PRN_MODULO); |
| } |
| |
| /* |
| * Custom integer square root from |
| * http://en.wikipedia.org/wiki/Integer_square_root |
| */ |
| static int sqrti(int val) |
| { |
| float d, x = val; |
| |
| if (val == 0) |
| return 0; |
| |
| do { |
| float y = (x + (float)val / x) / 2; |
| d = (y > x) ? y - x : x - y; |
| x = y; |
| } while (d >= 0.5); |
| |
| return (int)x; |
| } |
| |
| static struct commit_list *skip_away(struct commit_list *list, int count) |
| { |
| struct commit_list *cur, *previous; |
| int prn, index, i; |
| |
| prn = get_prn(count); |
| index = (count * prn / PRN_MODULO) * sqrti(prn) / sqrti(PRN_MODULO); |
| |
| cur = list; |
| previous = NULL; |
| |
| for (i = 0; cur; cur = cur->next, i++) { |
| if (i == index) { |
| if (hashcmp(cur->item->object.sha1, current_bad_sha1)) |
| return cur; |
| if (previous) |
| return previous; |
| return list; |
| } |
| previous = cur; |
| } |
| |
| return list; |
| } |
| |
| static struct commit_list *managed_skipped(struct commit_list *list, |
| struct commit_list **tried) |
| { |
| int count, skipped_first; |
| |
| *tried = NULL; |
| |
| if (!skipped_revs.nr) |
| return list; |
| |
| list = filter_skipped(list, tried, 0, &count, &skipped_first); |
| |
| if (!skipped_first) |
| return list; |
| |
| return skip_away(list, count); |
| } |
| |
| static void bisect_rev_setup(struct rev_info *revs, const char *prefix, |
| const char *bad_format, const char *good_format, |
| int read_paths) |
| { |
| struct argv_array rev_argv = ARGV_ARRAY_INIT; |
| int i; |
| |
| init_revisions(revs, prefix); |
| revs->abbrev = 0; |
| revs->commit_format = CMIT_FMT_UNSPECIFIED; |
| |
| /* rev_argv.argv[0] will be ignored by setup_revisions */ |
| argv_array_push(&rev_argv, "bisect_rev_setup"); |
| argv_array_pushf(&rev_argv, bad_format, sha1_to_hex(current_bad_sha1)); |
| for (i = 0; i < good_revs.nr; i++) |
| argv_array_pushf(&rev_argv, good_format, |
| sha1_to_hex(good_revs.sha1[i])); |
| argv_array_push(&rev_argv, "--"); |
| if (read_paths) |
| read_bisect_paths(&rev_argv); |
| |
| setup_revisions(rev_argv.argc, rev_argv.argv, revs, NULL); |
| /* XXX leak rev_argv, as "revs" may still be pointing to it */ |
| } |
| |
| static void bisect_common(struct rev_info *revs) |
| { |
| if (prepare_revision_walk(revs)) |
| die("revision walk setup failed"); |
| if (revs->tree_objects) |
| mark_edges_uninteresting(revs->commits, revs, NULL); |
| } |
| |
| static void exit_if_skipped_commits(struct commit_list *tried, |
| const unsigned char *bad) |
| { |
| if (!tried) |
| return; |
| |
| printf("There are only 'skip'ped commits left to test.\n" |
| "The first bad commit could be any of:\n"); |
| print_commit_list(tried, "%s\n", "%s\n"); |
| if (bad) |
| printf("%s\n", sha1_to_hex(bad)); |
| printf("We cannot bisect more!\n"); |
| exit(2); |
| } |
| |
| static int is_expected_rev(const unsigned char *sha1) |
| { |
| const char *filename = git_path("BISECT_EXPECTED_REV"); |
| struct stat st; |
| struct strbuf str = STRBUF_INIT; |
| FILE *fp; |
| int res = 0; |
| |
| if (stat(filename, &st) || !S_ISREG(st.st_mode)) |
| return 0; |
| |
| fp = fopen(filename, "r"); |
| if (!fp) |
| return 0; |
| |
| if (strbuf_getline(&str, fp, '\n') != EOF) |
| res = !strcmp(str.buf, sha1_to_hex(sha1)); |
| |
| strbuf_release(&str); |
| fclose(fp); |
| |
| return res; |
| } |
| |
| static void mark_expected_rev(char *bisect_rev_hex) |
| { |
| int len = strlen(bisect_rev_hex); |
| const char *filename = git_path("BISECT_EXPECTED_REV"); |
| int fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600); |
| |
| if (fd < 0) |
| die_errno("could not create file '%s'", filename); |
| |
| bisect_rev_hex[len] = '\n'; |
| write_or_die(fd, bisect_rev_hex, len + 1); |
| bisect_rev_hex[len] = '\0'; |
| |
| if (close(fd) < 0) |
| die("closing file %s: %s", filename, strerror(errno)); |
| } |
| |
| static int bisect_checkout(char *bisect_rev_hex, int no_checkout) |
| { |
| int res; |
| |
| mark_expected_rev(bisect_rev_hex); |
| |
| argv_checkout[2] = bisect_rev_hex; |
| if (no_checkout) { |
| argv_update_ref[3] = bisect_rev_hex; |
| if (run_command_v_opt(argv_update_ref, RUN_GIT_CMD)) |
| die("update-ref --no-deref HEAD failed on %s", |
| bisect_rev_hex); |
| } else { |
| res = run_command_v_opt(argv_checkout, RUN_GIT_CMD); |
| if (res) |
| exit(res); |
| } |
| |
| argv_show_branch[1] = bisect_rev_hex; |
| return run_command_v_opt(argv_show_branch, RUN_GIT_CMD); |
| } |
| |
| static struct commit *get_commit_reference(const unsigned char *sha1) |
| { |
| struct commit *r = lookup_commit_reference(sha1); |
| if (!r) |
| die("Not a valid commit name %s", sha1_to_hex(sha1)); |
| return r; |
| } |
| |
| static struct commit **get_bad_and_good_commits(int *rev_nr) |
| { |
| int len = 1 + good_revs.nr; |
| struct commit **rev = xmalloc(len * sizeof(*rev)); |
| int i, n = 0; |
| |
| rev[n++] = get_commit_reference(current_bad_sha1); |
| for (i = 0; i < good_revs.nr; i++) |
| rev[n++] = get_commit_reference(good_revs.sha1[i]); |
| *rev_nr = n; |
| |
| return rev; |
| } |
| |
| static void handle_bad_merge_base(void) |
| { |
| if (is_expected_rev(current_bad_sha1)) { |
| char *bad_hex = sha1_to_hex(current_bad_sha1); |
| char *good_hex = join_sha1_array_hex(&good_revs, ' '); |
| |
| fprintf(stderr, "The merge base %s is bad.\n" |
| "This means the bug has been fixed " |
| "between %s and [%s].\n", |
| bad_hex, bad_hex, good_hex); |
| |
| exit(3); |
| } |
| |
| fprintf(stderr, "Some good revs are not ancestor of the bad rev.\n" |
| "git bisect cannot work properly in this case.\n" |
| "Maybe you mistake good and bad revs?\n"); |
| exit(1); |
| } |
| |
| static void handle_skipped_merge_base(const unsigned char *mb) |
| { |
| char *mb_hex = sha1_to_hex(mb); |
| char *bad_hex = sha1_to_hex(current_bad_sha1); |
| char *good_hex = join_sha1_array_hex(&good_revs, ' '); |
| |
| warning("the merge base between %s and [%s] " |
| "must be skipped.\n" |
| "So we cannot be sure the first bad commit is " |
| "between %s and %s.\n" |
| "We continue anyway.", |
| bad_hex, good_hex, mb_hex, bad_hex); |
| free(good_hex); |
| } |
| |
| /* |
| * "check_merge_bases" checks that merge bases are not "bad". |
| * |
| * - If one is "bad", it means the user assumed something wrong |
| * and we must exit with a non 0 error code. |
| * - If one is "good", that's good, we have nothing to do. |
| * - If one is "skipped", we can't know but we should warn. |
| * - If we don't know, we should check it out and ask the user to test. |
| */ |
| static void check_merge_bases(int no_checkout) |
| { |
| struct commit_list *result; |
| int rev_nr; |
| struct commit **rev = get_bad_and_good_commits(&rev_nr); |
| |
| result = get_merge_bases_many(rev[0], rev_nr - 1, rev + 1, 0); |
| |
| for (; result; result = result->next) { |
| const unsigned char *mb = result->item->object.sha1; |
| if (!hashcmp(mb, current_bad_sha1)) { |
| handle_bad_merge_base(); |
| } else if (0 <= sha1_array_lookup(&good_revs, mb)) { |
| continue; |
| } else if (0 <= sha1_array_lookup(&skipped_revs, mb)) { |
| handle_skipped_merge_base(mb); |
| } else { |
| printf("Bisecting: a merge base must be tested\n"); |
| exit(bisect_checkout(sha1_to_hex(mb), no_checkout)); |
| } |
| } |
| |
| free(rev); |
| free_commit_list(result); |
| } |
| |
| static int check_ancestors(const char *prefix) |
| { |
| struct rev_info revs; |
| struct object_array pending_copy; |
| int res; |
| |
| bisect_rev_setup(&revs, prefix, "^%s", "%s", 0); |
| |
| /* Save pending objects, so they can be cleaned up later. */ |
| pending_copy = revs.pending; |
| revs.leak_pending = 1; |
| |
| /* |
| * bisect_common calls prepare_revision_walk right away, which |
| * (together with .leak_pending = 1) makes us the sole owner of |
| * the list of pending objects. |
| */ |
| bisect_common(&revs); |
| res = (revs.commits != NULL); |
| |
| /* Clean up objects used, as they will be reused. */ |
| clear_commit_marks_for_object_array(&pending_copy, ALL_REV_FLAGS); |
| free(pending_copy.objects); |
| |
| return res; |
| } |
| |
| /* |
| * "check_good_are_ancestors_of_bad" checks that all "good" revs are |
| * ancestor of the "bad" rev. |
| * |
| * If that's not the case, we need to check the merge bases. |
| * If a merge base must be tested by the user, its source code will be |
| * checked out to be tested by the user and we will exit. |
| */ |
| static void check_good_are_ancestors_of_bad(const char *prefix, int no_checkout) |
| { |
| char *filename = git_pathdup("BISECT_ANCESTORS_OK"); |
| struct stat st; |
| int fd; |
| |
| if (!current_bad_sha1) |
| die("a bad revision is needed"); |
| |
| /* Check if file BISECT_ANCESTORS_OK exists. */ |
| if (!stat(filename, &st) && S_ISREG(st.st_mode)) |
| goto done; |
| |
| /* Bisecting with no good rev is ok. */ |
| if (good_revs.nr == 0) |
| goto done; |
| |
| /* Check if all good revs are ancestor of the bad rev. */ |
| if (check_ancestors(prefix)) |
| check_merge_bases(no_checkout); |
| |
| /* Create file BISECT_ANCESTORS_OK. */ |
| fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600); |
| if (fd < 0) |
| warning("could not create file '%s': %s", |
| filename, strerror(errno)); |
| else |
| close(fd); |
| done: |
| free(filename); |
| } |
| |
| /* |
| * This does "git diff-tree --pretty COMMIT" without one fork+exec. |
| */ |
| static void show_diff_tree(const char *prefix, struct commit *commit) |
| { |
| struct rev_info opt; |
| |
| /* diff-tree init */ |
| init_revisions(&opt, prefix); |
| git_config(git_diff_basic_config, NULL); /* no "diff" UI options */ |
| opt.abbrev = 0; |
| opt.diff = 1; |
| |
| /* This is what "--pretty" does */ |
| opt.verbose_header = 1; |
| opt.use_terminator = 0; |
| opt.commit_format = CMIT_FMT_DEFAULT; |
| |
| /* diff-tree init */ |
| if (!opt.diffopt.output_format) |
| opt.diffopt.output_format = DIFF_FORMAT_RAW; |
| |
| log_tree_commit(&opt, commit); |
| } |
| |
| /* |
| * We use the convention that exiting with an exit code 10 means that |
| * the bisection process finished successfully. |
| * In this case the calling shell script should exit 0. |
| * |
| * If no_checkout is non-zero, the bisection process does not |
| * checkout the trial commit but instead simply updates BISECT_HEAD. |
| */ |
| int bisect_next_all(const char *prefix, int no_checkout) |
| { |
| struct rev_info revs; |
| struct commit_list *tried; |
| int reaches = 0, all = 0, nr, steps; |
| const unsigned char *bisect_rev; |
| char bisect_rev_hex[41]; |
| |
| if (read_bisect_refs()) |
| die("reading bisect refs failed"); |
| |
| check_good_are_ancestors_of_bad(prefix, no_checkout); |
| |
| bisect_rev_setup(&revs, prefix, "%s", "^%s", 1); |
| revs.limited = 1; |
| |
| bisect_common(&revs); |
| |
| revs.commits = find_bisection(revs.commits, &reaches, &all, |
| !!skipped_revs.nr); |
| revs.commits = managed_skipped(revs.commits, &tried); |
| |
| if (!revs.commits) { |
| /* |
| * We should exit here only if the "bad" |
| * commit is also a "skip" commit. |
| */ |
| exit_if_skipped_commits(tried, NULL); |
| |
| printf("%s was both good and bad\n", |
| sha1_to_hex(current_bad_sha1)); |
| exit(1); |
| } |
| |
| if (!all) { |
| fprintf(stderr, "No testable commit found.\n" |
| "Maybe you started with bad path parameters?\n"); |
| exit(4); |
| } |
| |
| bisect_rev = revs.commits->item->object.sha1; |
| memcpy(bisect_rev_hex, sha1_to_hex(bisect_rev), 41); |
| |
| if (!hashcmp(bisect_rev, current_bad_sha1)) { |
| exit_if_skipped_commits(tried, current_bad_sha1); |
| printf("%s is the first bad commit\n", bisect_rev_hex); |
| show_diff_tree(prefix, revs.commits->item); |
| /* This means the bisection process succeeded. */ |
| exit(10); |
| } |
| |
| nr = all - reaches - 1; |
| steps = estimate_bisect_steps(all); |
| printf("Bisecting: %d revision%s left to test after this " |
| "(roughly %d step%s)\n", nr, (nr == 1 ? "" : "s"), |
| steps, (steps == 1 ? "" : "s")); |
| |
| return bisect_checkout(bisect_rev_hex, no_checkout); |
| } |
| |
| static inline int log2i(int n) |
| { |
| int log2 = 0; |
| |
| for (; n > 1; n >>= 1) |
| log2++; |
| |
| return log2; |
| } |
| |
| static inline int exp2i(int n) |
| { |
| return 1 << n; |
| } |
| |
| /* |
| * Estimate the number of bisect steps left (after the current step) |
| * |
| * For any x between 0 included and 2^n excluded, the probability for |
| * n - 1 steps left looks like: |
| * |
| * P(2^n + x) == (2^n - x) / (2^n + x) |
| * |
| * and P(2^n + x) < 0.5 means 2^n < 3x |
| */ |
| int estimate_bisect_steps(int all) |
| { |
| int n, x, e; |
| |
| if (all < 3) |
| return 0; |
| |
| n = log2i(all); |
| e = exp2i(n); |
| x = all - e; |
| |
| return (e < 3 * x) ? n : n - 1; |
| } |