| #include "cache.h" |
| #include "config.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 "oid-array.h" |
| #include "strvec.h" |
| #include "commit-slab.h" |
| #include "commit-reach.h" |
| #include "object-store.h" |
| #include "dir.h" |
| |
| static struct oid_array good_revs; |
| static struct oid_array skipped_revs; |
| |
| static struct object_id *current_bad_oid; |
| |
| static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL}; |
| static const char *argv_show_branch[] = {"show-branch", NULL, NULL}; |
| |
| static const char *term_bad; |
| static const char *term_good; |
| |
| /* Remember to update object flag allocation in object.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_commit_slab(commit_weight, int *); |
| static struct commit_weight commit_weight; |
| |
| #define DEBUG_BISECT 0 |
| |
| static inline int weight(struct commit_list *elem) |
| { |
| return **commit_weight_at(&commit_weight, elem->item); |
| } |
| |
| static inline void weight_set(struct commit_list *elem, int weight) |
| { |
| **commit_weight_at(&commit_weight, elem->item) = weight; |
| } |
| |
| static int count_interesting_parents(struct commit *commit, unsigned bisect_flags) |
| { |
| struct commit_list *p; |
| int count; |
| |
| for (count = 0, p = commit->parents; p; p = p->next) { |
| if (!(p->item->object.flags & UNINTERESTING)) |
| count++; |
| if (bisect_flags & FIND_BISECTION_FIRST_PARENT_ONLY) |
| break; |
| } |
| return count; |
| } |
| |
| static inline int approx_halfway(struct commit_list *p, int nr) |
| { |
| int diff; |
| |
| /* |
| * Don't short-cut something we are not going to return! |
| */ |
| if (p->item->object.flags & TREESAME) |
| return 0; |
| if (DEBUG_BISECT) |
| return 0; |
| /* |
| * For small number of commits 2 and 3 are halfway of 5, and |
| * 3 is halfway of 6 but 2 and 4 are not. |
| */ |
| diff = 2 * weight(p) - nr; |
| switch (diff) { |
| case -1: case 0: case 1: |
| return 1; |
| default: |
| /* |
| * For large number of commits we are not so strict, it's |
| * good enough if it's within ~0.1% of the halfway point, |
| * e.g. 5000 is exactly halfway of 10000, but we consider |
| * the values [4996, 5004] as halfway as well. |
| */ |
| if (abs(diff) < nr / 1024) |
| return 1; |
| return 0; |
| } |
| } |
| |
| static void show_list(const char *debug, int counted, int nr, |
| struct commit_list *list) |
| { |
| struct commit_list *p; |
| |
| if (!DEBUG_BISECT) |
| return; |
| |
| 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 commit_flags = commit->object.flags; |
| enum object_type type; |
| unsigned long size; |
| char *buf = read_object_file(&commit->object.oid, &type, |
| &size); |
| const char *subject_start; |
| int subject_len; |
| |
| fprintf(stderr, "%c%c%c ", |
| (commit_flags & TREESAME) ? ' ' : 'T', |
| (commit_flags & UNINTERESTING) ? 'U' : ' ', |
| (commit_flags & COUNTED) ? 'C' : ' '); |
| if (*commit_weight_at(&commit_weight, p->item)) |
| fprintf(stderr, "%3d", weight(p)); |
| else |
| fprintf(stderr, "---"); |
| fprintf(stderr, " %.*s", 8, oid_to_hex(&commit->object.oid)); |
| for (pp = commit->parents; pp; pp = pp->next) |
| fprintf(stderr, " %.*s", 8, |
| oid_to_hex(&pp->item->object.oid)); |
| |
| subject_len = find_commit_subject(buf, &subject_start); |
| if (subject_len) |
| fprintf(stderr, " %.*s", subject_len, subject_start); |
| fprintf(stderr, "\n"); |
| } |
| } |
| |
| 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 commit_flags = p->item->object.flags; |
| |
| if (commit_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 oidcmp(&a->commit->object.oid, &b->commit->object.oid); |
| } |
| |
| 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)); |
| struct strbuf buf = STRBUF_INIT; |
| int cnt, i; |
| |
| for (p = list, cnt = 0; p; p = p->next) { |
| int distance; |
| unsigned commit_flags = p->item->object.flags; |
| |
| if (commit_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, compare_commit_dist); |
| for (p = list, i = 0; i < cnt; i++) { |
| struct object *obj = &(array[i].commit->object); |
| |
| strbuf_reset(&buf); |
| strbuf_addf(&buf, "dist=%d", array[i].distance); |
| add_name_decoration(DECORATION_NONE, buf.buf, obj); |
| |
| p->item = array[i].commit; |
| if (i < cnt - 1) |
| p = p->next; |
| } |
| if (p) { |
| free_commit_list(p->next); |
| p->next = NULL; |
| } |
| strbuf_release(&buf); |
| 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, |
| unsigned bisect_flags) |
| { |
| int n, counted; |
| struct commit_list *p; |
| |
| counted = 0; |
| |
| for (n = 0, p = list; p; p = p->next) { |
| struct commit *commit = p->item; |
| unsigned commit_flags = commit->object.flags; |
| |
| *commit_weight_at(&commit_weight, p->item) = &weights[n++]; |
| switch (count_interesting_parents(commit, bisect_flags)) { |
| case 0: |
| if (!(commit_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; |
| if (bisect_flags & FIND_BISECTION_FIRST_PARENT_ONLY) |
| BUG("shouldn't be calling count-distance in fp mode"); |
| weight_set(p, count_distance(p)); |
| clear_distance(list); |
| |
| /* Does it happen to be at half-way? */ |
| if (!(bisect_flags & FIND_BISECTION_ALL) && |
| approx_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 commit_flags = p->item->object.flags; |
| |
| if (0 <= weight(p)) |
| continue; |
| |
| for (q = p->item->parents; |
| q; |
| q = bisect_flags & FIND_BISECTION_FIRST_PARENT_ONLY ? NULL : 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 (!(commit_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 half-way? */ |
| if (!(bisect_flags & FIND_BISECTION_ALL) && |
| approx_halfway(p, nr)) |
| return p; |
| } |
| } |
| |
| show_list("bisection 2 counted all", counted, nr, list); |
| |
| if (!(bisect_flags & FIND_BISECTION_ALL)) |
| return best_bisection(list, nr); |
| else |
| return best_bisection_sorted(list, nr); |
| } |
| |
| void find_bisection(struct commit_list **commit_list, int *reaches, |
| int *all, unsigned bisect_flags) |
| { |
| int nr, on_list; |
| struct commit_list *list, *p, *best, *next, *last; |
| int *weights; |
| |
| show_list("bisection 2 entry", 0, 0, *commit_list); |
| init_commit_weight(&commit_weight); |
| |
| /* |
| * Count the number of total and tree-changing items on the |
| * list, while reversing the list. |
| */ |
| for (nr = on_list = 0, last = NULL, p = *commit_list; |
| p; |
| p = next) { |
| unsigned commit_flags = p->item->object.flags; |
| |
| next = p->next; |
| if (commit_flags & UNINTERESTING) { |
| free(p); |
| continue; |
| } |
| p->next = last; |
| last = p; |
| if (!(commit_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, bisect_flags); |
| if (best) { |
| if (!(bisect_flags & FIND_BISECTION_ALL)) { |
| list->item = best->item; |
| free_commit_list(list->next); |
| best = list; |
| best->next = NULL; |
| } |
| *reaches = weight(best); |
| } |
| free(weights); |
| *commit_list = best; |
| clear_commit_weight(&commit_weight); |
| } |
| |
| static int register_ref(const char *refname, const struct object_id *oid, |
| int flags, void *cb_data) |
| { |
| struct strbuf good_prefix = STRBUF_INIT; |
| strbuf_addstr(&good_prefix, term_good); |
| strbuf_addstr(&good_prefix, "-"); |
| |
| if (!strcmp(refname, term_bad)) { |
| current_bad_oid = xmalloc(sizeof(*current_bad_oid)); |
| oidcpy(current_bad_oid, oid); |
| } else if (starts_with(refname, good_prefix.buf)) { |
| oid_array_append(&good_revs, oid); |
| } else if (starts_with(refname, "skip-")) { |
| oid_array_append(&skipped_revs, oid); |
| } |
| |
| strbuf_release(&good_prefix); |
| |
| return 0; |
| } |
| |
| static int read_bisect_refs(void) |
| { |
| return for_each_ref_in("refs/bisect/", register_ref, NULL); |
| } |
| |
| static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES") |
| static GIT_PATH_FUNC(git_path_bisect_expected_rev, "BISECT_EXPECTED_REV") |
| static GIT_PATH_FUNC(git_path_bisect_ancestors_ok, "BISECT_ANCESTORS_OK") |
| static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN") |
| static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START") |
| static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG") |
| static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS") |
| static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT") |
| static GIT_PATH_FUNC(git_path_head_name, "head-name") |
| |
| static void read_bisect_paths(struct strvec *array) |
| { |
| struct strbuf str = STRBUF_INIT; |
| const char *filename = git_path_bisect_names(); |
| FILE *fp = xfopen(filename, "r"); |
| |
| while (strbuf_getline_lf(&str, fp) != EOF) { |
| strbuf_trim(&str); |
| if (sq_dequote_to_strvec(str.buf, array)) |
| die(_("Badly quoted content in file '%s': %s"), |
| filename, str.buf); |
| } |
| |
| strbuf_release(&str); |
| fclose(fp); |
| } |
| |
| static char *join_oid_array_hex(struct oid_array *array, char delim) |
| { |
| struct strbuf joined_hexs = STRBUF_INIT; |
| int i; |
| |
| for (i = 0; i < array->nr; i++) { |
| strbuf_addstr(&joined_hexs, oid_to_hex(array->oid + 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 <= oid_array_lookup(&skipped_revs, &list->item->object.oid)) { |
| 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 unsigned get_prn(unsigned count) |
| { |
| count = count * 1103515245 + 12345; |
| return (count/65536) % PRN_MODULO; |
| } |
| |
| /* |
| * Custom integer square root from |
| * https://en.wikipedia.org/wiki/Integer_square_root |
| */ |
| static int sqrti(int val) |
| { |
| float d, x = val; |
| |
| if (!val) |
| 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 (!oideq(&cur->item->object.oid, current_bad_oid)) |
| 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 repository *r, struct rev_info *revs, |
| const char *prefix, |
| const char *bad_format, const char *good_format, |
| int read_paths) |
| { |
| struct strvec rev_argv = STRVEC_INIT; |
| int i; |
| |
| repo_init_revisions(r, revs, prefix); |
| revs->abbrev = 0; |
| revs->commit_format = CMIT_FMT_UNSPECIFIED; |
| |
| /* rev_argv.argv[0] will be ignored by setup_revisions */ |
| strvec_push(&rev_argv, "bisect_rev_setup"); |
| strvec_pushf(&rev_argv, bad_format, oid_to_hex(current_bad_oid)); |
| for (i = 0; i < good_revs.nr; i++) |
| strvec_pushf(&rev_argv, good_format, |
| oid_to_hex(good_revs.oid + i)); |
| strvec_push(&rev_argv, "--"); |
| if (read_paths) |
| read_bisect_paths(&rev_argv); |
| |
| setup_revisions(rev_argv.nr, rev_argv.v, 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, NULL, 0); |
| } |
| |
| static enum bisect_error error_if_skipped_commits(struct commit_list *tried, |
| const struct object_id *bad) |
| { |
| if (!tried) |
| return BISECT_OK; |
| |
| printf("There are only 'skip'ped commits left to test.\n" |
| "The first %s commit could be any of:\n", term_bad); |
| |
| for ( ; tried; tried = tried->next) |
| printf("%s\n", oid_to_hex(&tried->item->object.oid)); |
| |
| if (bad) |
| printf("%s\n", oid_to_hex(bad)); |
| printf(_("We cannot bisect more!\n")); |
| |
| return BISECT_ONLY_SKIPPED_LEFT; |
| } |
| |
| static int is_expected_rev(const struct object_id *oid) |
| { |
| 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_or_warn(filename, "r"); |
| if (!fp) |
| return 0; |
| |
| if (strbuf_getline_lf(&str, fp) != EOF) |
| res = !strcmp(str.buf, oid_to_hex(oid)); |
| |
| strbuf_release(&str); |
| fclose(fp); |
| |
| return res; |
| } |
| |
| static enum bisect_error bisect_checkout(const struct object_id *bisect_rev, int no_checkout) |
| { |
| char bisect_rev_hex[GIT_MAX_HEXSZ + 1]; |
| enum bisect_error res = BISECT_OK; |
| |
| oid_to_hex_r(bisect_rev_hex, bisect_rev); |
| update_ref(NULL, "BISECT_EXPECTED_REV", bisect_rev, NULL, 0, UPDATE_REFS_DIE_ON_ERR); |
| |
| argv_checkout[2] = bisect_rev_hex; |
| if (no_checkout) { |
| update_ref(NULL, "BISECT_HEAD", bisect_rev, NULL, 0, |
| UPDATE_REFS_DIE_ON_ERR); |
| } else { |
| res = run_command_v_opt(argv_checkout, RUN_GIT_CMD); |
| if (res) |
| /* |
| * Errors in `run_command()` itself, signaled by res < 0, |
| * and errors in the child process, signaled by res > 0 |
| * can both be treated as regular BISECT_FAILURE (-1). |
| */ |
| return -abs(res); |
| } |
| |
| argv_show_branch[1] = bisect_rev_hex; |
| res = run_command_v_opt(argv_show_branch, RUN_GIT_CMD); |
| /* |
| * Errors in `run_command()` itself, signaled by res < 0, |
| * and errors in the child process, signaled by res > 0 |
| * can both be treated as regular BISECT_FAILURE (-1). |
| */ |
| return -abs(res); |
| } |
| |
| static struct commit *get_commit_reference(struct repository *r, |
| const struct object_id *oid) |
| { |
| struct commit *c = lookup_commit_reference(r, oid); |
| if (!c) |
| die(_("Not a valid commit name %s"), oid_to_hex(oid)); |
| return c; |
| } |
| |
| static struct commit **get_bad_and_good_commits(struct repository *r, |
| int *rev_nr) |
| { |
| struct commit **rev; |
| int i, n = 0; |
| |
| ALLOC_ARRAY(rev, 1 + good_revs.nr); |
| rev[n++] = get_commit_reference(r, current_bad_oid); |
| for (i = 0; i < good_revs.nr; i++) |
| rev[n++] = get_commit_reference(r, good_revs.oid + i); |
| *rev_nr = n; |
| |
| return rev; |
| } |
| |
| static enum bisect_error handle_bad_merge_base(void) |
| { |
| if (is_expected_rev(current_bad_oid)) { |
| char *bad_hex = oid_to_hex(current_bad_oid); |
| char *good_hex = join_oid_array_hex(&good_revs, ' '); |
| if (!strcmp(term_bad, "bad") && !strcmp(term_good, "good")) { |
| 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); |
| } else if (!strcmp(term_bad, "new") && !strcmp(term_good, "old")) { |
| fprintf(stderr, _("The merge base %s is new.\n" |
| "The property has changed " |
| "between %s and [%s].\n"), |
| bad_hex, bad_hex, good_hex); |
| } else { |
| fprintf(stderr, _("The merge base %s is %s.\n" |
| "This means the first '%s' commit is " |
| "between %s and [%s].\n"), |
| bad_hex, term_bad, term_good, bad_hex, good_hex); |
| } |
| return BISECT_MERGE_BASE_CHECK; |
| } |
| |
| fprintf(stderr, _("Some %s revs are not ancestors of the %s rev.\n" |
| "git bisect cannot work properly in this case.\n" |
| "Maybe you mistook %s and %s revs?\n"), |
| term_good, term_bad, term_good, term_bad); |
| return BISECT_FAILED; |
| } |
| |
| static void handle_skipped_merge_base(const struct object_id *mb) |
| { |
| char *mb_hex = oid_to_hex(mb); |
| char *bad_hex = oid_to_hex(current_bad_oid); |
| char *good_hex = join_oid_array_hex(&good_revs, ' '); |
| |
| warning(_("the merge base between %s and [%s] " |
| "must be skipped.\n" |
| "So we cannot be sure the first %s commit is " |
| "between %s and %s.\n" |
| "We continue anyway."), |
| bad_hex, good_hex, term_bad, mb_hex, bad_hex); |
| free(good_hex); |
| } |
| |
| /* |
| * "check_merge_bases" checks that merge bases are not "bad" (or "new"). |
| * |
| * - If one is "bad" (or "new"), it means the user assumed something wrong |
| * and we must return error with a non 0 error code. |
| * - If one is "good" (or "old"), 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. |
| * - If a merge base must be tested, on success return |
| * BISECT_INTERNAL_SUCCESS_MERGE_BASE (-11) a special condition |
| * for early success, this will be converted back to 0 in |
| * check_good_are_ancestors_of_bad(). |
| */ |
| static enum bisect_error check_merge_bases(int rev_nr, struct commit **rev, int no_checkout) |
| { |
| enum bisect_error res = BISECT_OK; |
| struct commit_list *result; |
| |
| result = get_merge_bases_many(rev[0], rev_nr - 1, rev + 1); |
| |
| for (; result; result = result->next) { |
| const struct object_id *mb = &result->item->object.oid; |
| if (oideq(mb, current_bad_oid)) { |
| res = handle_bad_merge_base(); |
| break; |
| } else if (0 <= oid_array_lookup(&good_revs, mb)) { |
| continue; |
| } else if (0 <= oid_array_lookup(&skipped_revs, mb)) { |
| handle_skipped_merge_base(mb); |
| } else { |
| printf(_("Bisecting: a merge base must be tested\n")); |
| res = bisect_checkout(mb, no_checkout); |
| if (!res) |
| /* indicate early success */ |
| res = BISECT_INTERNAL_SUCCESS_MERGE_BASE; |
| break; |
| } |
| } |
| |
| free_commit_list(result); |
| return res; |
| } |
| |
| static int check_ancestors(struct repository *r, int rev_nr, |
| struct commit **rev, const char *prefix) |
| { |
| struct rev_info revs; |
| int res; |
| |
| bisect_rev_setup(r, &revs, prefix, "^%s", "%s", 0); |
| |
| bisect_common(&revs); |
| res = (revs.commits != NULL); |
| |
| /* Clean up objects used, as they will be reused. */ |
| clear_commit_marks_many(rev_nr, rev, ALL_REV_FLAGS); |
| |
| 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 return. |
| */ |
| |
| static enum bisect_error check_good_are_ancestors_of_bad(struct repository *r, |
| const char *prefix, |
| int no_checkout) |
| { |
| char *filename; |
| struct stat st; |
| int fd, rev_nr; |
| enum bisect_error res = BISECT_OK; |
| struct commit **rev; |
| |
| if (!current_bad_oid) |
| return error(_("a %s revision is needed"), term_bad); |
| |
| filename = git_pathdup("BISECT_ANCESTORS_OK"); |
| |
| /* 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) |
| goto done; |
| |
| /* Check if all good revs are ancestor of the bad rev. */ |
| |
| rev = get_bad_and_good_commits(r, &rev_nr); |
| if (check_ancestors(r, rev_nr, rev, prefix)) |
| res = check_merge_bases(rev_nr, rev, no_checkout); |
| free(rev); |
| |
| if (!res) { |
| /* Create file BISECT_ANCESTORS_OK. */ |
| fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0600); |
| if (fd < 0) |
| /* |
| * BISECT_ANCESTORS_OK file is not absolutely necessary, |
| * the bisection process will continue at the next |
| * bisection step. |
| * So, just signal with a warning that something |
| * might be wrong. |
| */ |
| warning_errno(_("could not create file '%s'"), |
| filename); |
| else |
| close(fd); |
| } |
| done: |
| free(filename); |
| return res; |
| } |
| |
| /* |
| * This does "git diff-tree --pretty COMMIT" without one fork+exec. |
| */ |
| static void show_diff_tree(struct repository *r, |
| const char *prefix, |
| struct commit *commit) |
| { |
| const char *argv[] = { |
| "diff-tree", "--pretty", "--stat", "--summary", "--cc", NULL |
| }; |
| struct rev_info opt; |
| |
| git_config(git_diff_ui_config, NULL); |
| repo_init_revisions(r, &opt, prefix); |
| |
| setup_revisions(ARRAY_SIZE(argv) - 1, argv, &opt, NULL); |
| log_tree_commit(&opt, commit); |
| } |
| |
| /* |
| * The terms used for this bisect session are stored in BISECT_TERMS. |
| * We read them and store them to adapt the messages accordingly. |
| * Default is bad/good. |
| */ |
| void read_bisect_terms(const char **read_bad, const char **read_good) |
| { |
| struct strbuf str = STRBUF_INIT; |
| const char *filename = git_path_bisect_terms(); |
| FILE *fp = fopen(filename, "r"); |
| |
| if (!fp) { |
| if (errno == ENOENT) { |
| *read_bad = "bad"; |
| *read_good = "good"; |
| return; |
| } else { |
| die_errno(_("could not read file '%s'"), filename); |
| } |
| } else { |
| strbuf_getline_lf(&str, fp); |
| *read_bad = strbuf_detach(&str, NULL); |
| strbuf_getline_lf(&str, fp); |
| *read_good = strbuf_detach(&str, NULL); |
| } |
| strbuf_release(&str); |
| fclose(fp); |
| } |
| |
| /* |
| * We use the convention that return BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND (-10) means |
| * the bisection process finished successfully. |
| * In this case the calling function or command should not turn a |
| * BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND return code into an error or a non zero exit code. |
| * |
| * Checking BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND |
| * in bisect_helper::bisect_next() and only transforming it to 0 at |
| * the end of bisect_helper::cmd_bisect__helper() helps bypassing |
| * all the code related to finding a commit to test. |
| */ |
| enum bisect_error bisect_next_all(struct repository *r, const char *prefix) |
| { |
| struct rev_info revs; |
| struct commit_list *tried; |
| int reaches = 0, all = 0, nr, steps; |
| enum bisect_error res = BISECT_OK; |
| struct object_id *bisect_rev; |
| char *steps_msg; |
| /* |
| * If no_checkout is non-zero, the bisection process does not |
| * checkout the trial commit but instead simply updates BISECT_HEAD. |
| */ |
| int no_checkout = ref_exists("BISECT_HEAD"); |
| unsigned bisect_flags = 0; |
| |
| read_bisect_terms(&term_bad, &term_good); |
| if (read_bisect_refs()) |
| die(_("reading bisect refs failed")); |
| |
| if (file_exists(git_path_bisect_first_parent())) |
| bisect_flags |= FIND_BISECTION_FIRST_PARENT_ONLY; |
| |
| if (skipped_revs.nr) |
| bisect_flags |= FIND_BISECTION_ALL; |
| |
| res = check_good_are_ancestors_of_bad(r, prefix, no_checkout); |
| if (res) |
| return res; |
| |
| bisect_rev_setup(r, &revs, prefix, "%s", "^%s", 1); |
| |
| revs.first_parent_only = !!(bisect_flags & FIND_BISECTION_FIRST_PARENT_ONLY); |
| revs.limited = 1; |
| |
| bisect_common(&revs); |
| |
| find_bisection(&revs.commits, &reaches, &all, bisect_flags); |
| revs.commits = managed_skipped(revs.commits, &tried); |
| |
| if (!revs.commits) { |
| /* |
| * We should return error here only if the "bad" |
| * commit is also a "skip" commit. |
| */ |
| res = error_if_skipped_commits(tried, NULL); |
| if (res < 0) |
| return res; |
| printf(_("%s was both %s and %s\n"), |
| oid_to_hex(current_bad_oid), |
| term_good, |
| term_bad); |
| |
| return BISECT_FAILED; |
| } |
| |
| if (!all) { |
| fprintf(stderr, _("No testable commit found.\n" |
| "Maybe you started with bad path parameters?\n")); |
| |
| return BISECT_NO_TESTABLE_COMMIT; |
| } |
| |
| bisect_rev = &revs.commits->item->object.oid; |
| |
| if (oideq(bisect_rev, current_bad_oid)) { |
| res = error_if_skipped_commits(tried, current_bad_oid); |
| if (res) |
| return res; |
| printf("%s is the first %s commit\n", oid_to_hex(bisect_rev), |
| term_bad); |
| |
| show_diff_tree(r, prefix, revs.commits->item); |
| /* |
| * This means the bisection process succeeded. |
| * Using BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND (-10) |
| * so that the call chain can simply check |
| * for negative return values for early returns up |
| * until the cmd_bisect__helper() caller. |
| */ |
| return BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND; |
| } |
| |
| nr = all - reaches - 1; |
| steps = estimate_bisect_steps(all); |
| |
| steps_msg = xstrfmt(Q_("(roughly %d step)", "(roughly %d steps)", |
| steps), steps); |
| /* |
| * TRANSLATORS: the last %s will be replaced with "(roughly %d |
| * steps)" translation. |
| */ |
| printf(Q_("Bisecting: %d revision left to test after this %s\n", |
| "Bisecting: %d revisions left to test after this %s\n", |
| nr), nr, steps_msg); |
| free(steps_msg); |
| /* Clean up objects used, as they will be reused. */ |
| repo_clear_commit_marks(r, ALL_REV_FLAGS); |
| |
| return bisect_checkout(bisect_rev, 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; |
| } |
| |
| static int mark_for_removal(const char *refname, const struct object_id *oid, |
| int flag, void *cb_data) |
| { |
| struct string_list *refs = cb_data; |
| char *ref = xstrfmt("refs/bisect%s", refname); |
| string_list_append(refs, ref); |
| return 0; |
| } |
| |
| int bisect_clean_state(void) |
| { |
| int result = 0; |
| |
| /* There may be some refs packed during bisection */ |
| struct string_list refs_for_removal = STRING_LIST_INIT_NODUP; |
| for_each_ref_in("refs/bisect", mark_for_removal, (void *) &refs_for_removal); |
| string_list_append(&refs_for_removal, xstrdup("BISECT_HEAD")); |
| result = delete_refs("bisect: remove", &refs_for_removal, REF_NO_DEREF); |
| refs_for_removal.strdup_strings = 1; |
| string_list_clear(&refs_for_removal, 0); |
| unlink_or_warn(git_path_bisect_expected_rev()); |
| unlink_or_warn(git_path_bisect_ancestors_ok()); |
| unlink_or_warn(git_path_bisect_log()); |
| unlink_or_warn(git_path_bisect_names()); |
| unlink_or_warn(git_path_bisect_run()); |
| unlink_or_warn(git_path_bisect_terms()); |
| unlink_or_warn(git_path_bisect_first_parent()); |
| /* Cleanup head-name if it got left by an old version of git-bisect */ |
| unlink_or_warn(git_path_head_name()); |
| /* |
| * Cleanup BISECT_START last to support the --no-checkout option |
| * introduced in the commit 4796e823a. |
| */ |
| unlink_or_warn(git_path_bisect_start()); |
| |
| return result; |
| } |