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Copy pathbisect.c
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1225 lines (1053 loc) · 31.3 KB
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#define USE_THE_REPOSITORY_VARIABLE
#define DISABLE_SIGN_COMPARE_WARNINGS
#include "git-compat-util.h"
#include "config.h"
#include "commit.h"
#include "diff.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "revision.h"
#include "refs.h"
#include "list-objects.h"
#include "quote.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-name.h"
#include "odb.h"
#include "path.h"
#include "dir.h"
static struct oid_array good_revs;
static struct oid_array skipped_revs;
static struct object_id *current_bad_oid;
static char *term_bad;
static 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;
size_t size;
char *buf = odb_read_object(the_repository->objects,
&commit->object.oid, &type,
&size);
const char *subject_start;
int subject_len;
if (!buf)
die(_("unable to read %s"), oid_to_hex(&commit->object.oid));
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) {
commit_list_free(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;
CALLOC_ARRAY(weights, on_list);
/* 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;
commit_list_free(list->next);
best = list;
best->next = NULL;
}
*reaches = weight(best);
}
*commit_list = best;
free(weights);
clear_commit_weight(&commit_weight);
}
static int register_ref(const struct reference *ref, void *cb_data UNUSED)
{
struct strbuf good_prefix = STRBUF_INIT;
strbuf_addstr(&good_prefix, term_good);
strbuf_addstr(&good_prefix, "-");
if (!strcmp(ref->name, term_bad)) {
free(current_bad_oid);
current_bad_oid = xmalloc(sizeof(*current_bad_oid));
oidcpy(current_bad_oid, ref->oid);
} else if (starts_with(ref->name, good_prefix.buf)) {
oid_array_append(&good_revs, ref->oid);
} else if (starts_with(ref->name, "skip-")) {
oid_array_append(&skipped_revs, ref->oid);
}
strbuf_release(&good_prefix);
return 0;
}
static int read_bisect_refs(void)
{
struct refs_for_each_ref_options opts = {
.prefix = "refs/bisect/",
.trim_prefix = strlen("refs/bisect/"),
};
return refs_for_each_ref_ext(get_main_ref_store(the_repository),
register_ref, NULL, &opts);
}
static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
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_bisect_reset_when_found, "BISECT_RESET_WHEN_FOUND")
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_add_oid_hex(&joined_hexs, 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) {
commit_list_free(next);
commit_list_free(filtered);
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, *result = list;
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))
result = cur;
else if (previous)
result = previous;
else
result = list;
break;
}
previous = cur;
}
for (cur = list; cur != result; ) {
struct commit_list *next = cur->next;
free(cur);
cur = next;
}
return result;
}
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,
struct strvec *rev_argv,
const char *prefix,
const char *bad_format, const char *good_format,
int read_paths)
{
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_from_strvec(rev_argv, revs, NULL);
}
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)
{
struct object_id expected_oid;
if (refs_read_ref(get_main_ref_store(the_repository), "BISECT_EXPECTED_REV", &expected_oid))
return 0;
return oideq(oid, &expected_oid);
}
enum bisect_error bisect_checkout(const struct object_id *bisect_rev,
int no_checkout)
{
struct commit *commit;
struct pretty_print_context pp = {0};
struct strbuf commit_msg = STRBUF_INIT;
refs_update_ref(get_main_ref_store(the_repository), NULL,
"BISECT_EXPECTED_REV", bisect_rev, NULL, 0,
UPDATE_REFS_DIE_ON_ERR);
if (no_checkout) {
refs_update_ref(get_main_ref_store(the_repository), NULL,
"BISECT_HEAD", bisect_rev, NULL, 0,
UPDATE_REFS_DIE_ON_ERR);
} else {
struct child_process cmd = CHILD_PROCESS_INIT;
cmd.git_cmd = 1;
strvec_pushl(&cmd.args, "checkout", "-q",
oid_to_hex(bisect_rev), "--", NULL);
if (run_command(&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_FAILED (-1).
*/
return BISECT_FAILED;
}
commit = lookup_commit_reference(the_repository, bisect_rev);
repo_format_commit_message(the_repository, commit, "[%H] %s%n",
&commit_msg, &pp);
fputs(commit_msg.buf, stdout);
strbuf_release(&commit_msg);
return BISECT_OK;
}
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,
size_t *rev_nr)
{
struct commit **rev;
size_t 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);
}
free(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(size_t rev_nr, struct commit **rev, int no_checkout)
{
enum bisect_error res = BISECT_OK;
struct commit_list *result = NULL;
if (repo_get_merge_bases_many(the_repository, rev[0], rev_nr - 1,
rev + 1, &result) < 0)
exit(128);
for (struct commit_list *l = result; l; l = l->next) {
const struct object_id *mb = &l->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;
}
}
commit_list_free(result);
return res;
}
static int check_ancestors(struct repository *r, size_t rev_nr,
struct commit **rev, const char *prefix)
{
struct strvec rev_argv = STRVEC_INIT;
struct rev_info revs;
int res;
bisect_rev_setup(r, &revs, &rev_argv, 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);
release_revisions(&revs);
strvec_clear(&rev_argv);
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;
size_t 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 = repo_git_path(the_repository, "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;
}
/*
* Display a commit summary to the user.
*/
static void show_commit(struct commit *commit)
{
struct child_process show = CHILD_PROCESS_INIT;
/*
* Call git show with --no-pager, as it would otherwise
* paginate the "git show" output only, not the output
* from bisect_next_all(); this can be fixed by moving
* it into a --format parameter, but that would override
* the user's default options for "git show", which we
* are trying to honour.
*/
strvec_pushl(&show.args,
"--no-pager",
"show",
"--stat",
"--summary",
"--no-abbrev-commit",
"--diff-merges=first-parent",
oid_to_hex(&commit->object.oid), NULL);
show.git_cmd = 1;
if (run_command(&show))
die(_("unable to start 'show' for object '%s'"),
oid_to_hex(&commit->object.oid));
}