bisect--helper: reimplement `bisect_state` & `bisect_head` shell functions in C

Reimplement the `bisect_state()` shell functions in C and also add a
subcommand `--bisect-state` to `git-bisect--helper` to call them from
git-bisect.sh .

Using `--bisect-state` subcommand is a temporary measure to port shell
function to C so as to use the existing test suite. As more functions
are ported, this subcommand will be retired and will be called by some
other methods.

`bisect_head()` is only called from `bisect_state()`, thus it is not
required to introduce another subcommand.

Note that the `eval` in the changed line of `git-bisect.sh` cannot be
dropped: it is necessary because the `rev` and the `tail`
variables may contain multiple, quoted arguments that need to be
passed to `bisect--helper` (without the quotes, naturally).

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 868bdb2c8b0aa99457bd98e0e7ddee930b23d0a9..afaf8efbb737e98b4f075bb61356e88f1d25f7cc 100644 (file)
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -31,6 +31,8 @@ static const char * const git_bisect_helper_usage[] = {
        N_("git bisect--helper --bisect-next"),
        N_("git bisect--helper --bisect-auto-next"),
        N_("git bisect--helper --bisect-autostart"),
+       N_("git bisect--helper --bisect-state (bad|new) [<rev>]"),
+       N_("git bisect--helper --bisect-state (good|old) [<rev>...]"),
        NULL
 };
 
@@ -855,6 +857,80 @@ static int bisect_autostart(struct bisect_terms *terms)
        return res;
 }
 
+static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
+                                     int argc)
+{
+       const char *state;
+       int i, verify_expected = 1;
+       struct object_id oid, expected;
+       struct strbuf buf = STRBUF_INIT;
+       struct oid_array revs = OID_ARRAY_INIT;
+
+       if (!argc)
+               return error(_("Please call `--bisect-state` with at least one argument"));
+
+       if (bisect_autostart(terms))
+               return BISECT_FAILED;
+
+       state = argv[0];
+       if (check_and_set_terms(terms, state) ||
+           !one_of(state, terms->term_good, terms->term_bad, "skip", NULL))
+               return BISECT_FAILED;
+
+       argv++;
+       argc--;
+       if (argc > 1 && !strcmp(state, terms->term_bad))
+               return error(_("'git bisect %s' can take only one argument."), terms->term_bad);
+
+       if (argc == 0) {
+               const char *head = "BISECT_HEAD";
+               enum get_oid_result res_head = get_oid(head, &oid);
+
+               if (res_head == MISSING_OBJECT) {
+                       head = "HEAD";
+                       res_head = get_oid(head, &oid);
+               }
+
+               if (res_head)
+                       error(_("Bad rev input: %s"), head);
+               oid_array_append(&revs, &oid);
+       }
+
+       /*
+        * All input revs must be checked before executing bisect_write()
+        * to discard junk revs.
+        */
+
+       for (; argc; argc--, argv++) {
+               if (get_oid(*argv, &oid)){
+                       error(_("Bad rev input: %s"), *argv);
+                       oid_array_clear(&revs);
+                       return BISECT_FAILED;
+               }
+               oid_array_append(&revs, &oid);
+       }
+
+       if (strbuf_read_file(&buf, git_path_bisect_expected_rev(), 0) < the_hash_algo->hexsz ||
+           get_oid_hex(buf.buf, &expected) < 0)
+               verify_expected = 0; /* Ignore invalid file contents */
+       strbuf_release(&buf);
+
+       for (i = 0; i < revs.nr; i++) {
+               if (bisect_write(state, oid_to_hex(&revs.oid[i]), terms, 0)) {
+                       oid_array_clear(&revs);
+                       return BISECT_FAILED;
+               }
+               if (verify_expected && !oideq(&revs.oid[i], &expected)) {
+                       unlink_or_warn(git_path_bisect_ancestors_ok());
+                       unlink_or_warn(git_path_bisect_expected_rev());
+                       verify_expected = 0;
+               }
+       }
+
+       oid_array_clear(&revs);
+       return bisect_auto_next(terms, NULL);
+}
+
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
        enum {
@@ -868,7 +944,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
                BISECT_START,
                BISECT_AUTOSTART,
                BISECT_NEXT,
-               BISECT_AUTO_NEXT
+               BISECT_AUTO_NEXT,
+               BISECT_STATE
        } cmdmode = 0;
        int res = 0, nolog = 0;
        struct option options[] = {
@@ -894,6 +971,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
                         N_("verify the next bisection state then checkout the next bisection commit"), BISECT_AUTO_NEXT),
                OPT_CMDMODE(0, "bisect-autostart", &cmdmode,
                         N_("start the bisection if it has not yet been started"), BISECT_AUTOSTART),
+               OPT_CMDMODE(0, "bisect-state", &cmdmode,
+                        N_("mark the state of ref (or refs)"), BISECT_STATE),
                OPT_BOOL(0, "no-log", &nolog,
                         N_("no log for BISECT_WRITE")),
                OPT_END()
@@ -964,6 +1043,11 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
                set_terms(&terms, "bad", "good");
                res = bisect_autostart(&terms);
                break;
+       case BISECT_STATE:
+               set_terms(&terms, "bad", "good");
+               get_terms(&terms);
+               res = bisect_state(&terms, argv, argc);
+               break;
        default:
                BUG("unknown subcommand %d", cmdmode);
        }

diff --git a/git-bisect.sh b/git-bisect.sh
index fd4342c408206796db18a1ada900712f478cb93e..882a647804ff23d0ddc1bd1773afe33faf4d6098 100755 (executable)
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -39,16 +39,6 @@ _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 TERM_BAD=bad
 TERM_GOOD=good
 
-bisect_head()
-{
-       if git rev-parse --verify -q BISECT_HEAD > /dev/null
-       then
-               echo BISECT_HEAD
-       else
-               echo HEAD
-       fi
-}
-
 bisect_skip() {
        all=''
        for arg in "$@"
@@ -61,43 +51,7 @@ bisect_skip() {
                esac
                all="$all $revs"
        done
-       eval bisect_state 'skip' $all
-}
-
-bisect_state() {
-       git bisect--helper --bisect-autostart || exit
-       state=$1
-       git bisect--helper --check-and-set-terms $state $TERM_GOOD $TERM_BAD || exit
-       get_terms
-       case "$#,$state" in
-       0,*)
-               die "Please call 'bisect_state' with at least one argument." ;;
-       1,"$TERM_BAD"|1,"$TERM_GOOD"|1,skip)
-               bisected_head=$(bisect_head)
-               rev=$(git rev-parse --verify "$bisected_head") ||
-                       die "$(eval_gettext "Bad rev input: \$bisected_head")"
-               git bisect--helper --bisect-write "$state" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit
-               git bisect--helper --check-expected-revs "$rev" ;;
-       2,"$TERM_BAD"|*,"$TERM_GOOD"|*,skip)
-               shift
-               hash_list=''
-               for rev in "$@"
-               do
-                       sha=$(git rev-parse --verify "$rev^{commit}") ||
-                               die "$(eval_gettext "Bad rev input: \$rev")"
-                       hash_list="$hash_list $sha"
-               done
-               for rev in $hash_list
-               do
-                       git bisect--helper --bisect-write "$state" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit
-               done
-               git bisect--helper --check-expected-revs $hash_list ;;
-       *,"$TERM_BAD")
-               die "$(eval_gettext "'git bisect \$TERM_BAD' can take only one argument.")" ;;
-       *)
-               usage ;;
-       esac
-       git bisect--helper --bisect-auto-next
+       eval git bisect--helper --bisect-state 'skip' $all
 }
 
 bisect_visualize() {
@@ -187,8 +141,7 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
                        state="$TERM_GOOD"
                fi
 
-               # We have to use a subshell because "bisect_state" can exit.
-               ( bisect_state $state >"$GIT_DIR/BISECT_RUN" )
+               git bisect--helper --bisect-state $state >"$GIT_DIR/BISECT_RUN"
                res=$?
 
                cat "$GIT_DIR/BISECT_RUN"
@@ -203,7 +156,7 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
                if [ $res -ne 0 ]
                then
                        eval_gettextln "bisect run failed:
-'bisect_state \$state' exited with error code \$res" >&2
+'bisect-state \$state' exited with error code \$res" >&2
                        exit $res
                fi
 
@@ -244,7 +197,7 @@ case "$#" in
        start)
                git bisect--helper --bisect-start "$@" ;;
        bad|good|new|old|"$TERM_BAD"|"$TERM_GOOD")
-               bisect_state "$cmd" "$@" ;;
+               git bisect--helper --bisect-state "$cmd" "$@" ;;
        skip)
                bisect_skip "$@" ;;
        next)