Re: [PATCH v4 5/6] bisect--helper: reimplement `bisect_run` shell function in C

Hi Johannes,

El mar, 17 ago 2021 a las 13:42, Johannes Schindelin
([off-list ref]) escribió:

Hi Miriam,

On Tue, 17 Aug 2021, Miriam Rubio wrote:

quoted

From: Tanushree Tumane <redacted>

Reimplement the `bisect_run()` shell function
in C and also add `--bisect-run` subcommand to
`git bisect--helper` to call it from git-bisect.sh.

Mentored-by: Christian Couder [off-list ref]
Signed-off-by: Tanushree Tumane <redacted>
Signed-off-by: Miriam Rubio <redacted>
---
 builtin/bisect--helper.c | 75 ++++++++++++++++++++++++++++++++++++++++
 git-bisect.sh            | 62 +--------------------------------
 2 files changed, 76 insertions(+), 61 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 4258429c1c..852e0a30fb 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c

@@ -31,6 +31,7 @@ static const char * const git_bisect_helper_usage[] = {
      N_("git bisect--helper --bisect-replay <filename>"),
      N_("git bisect--helper --bisect-skip [(<rev>|<range>)...]"),
      N_("git bisect--helper --bisect-visualize"),
+     N_("git bisect--helper --bisect-run <cmd>..."),
      NULL
 };

@@ -1075,6 +1076,71 @@ static int bisect_visualize(struct bisect_terms *terms, const char **argv, int a
      return res;
 }

+static int bisect_run(struct bisect_terms *terms, const char **argv, int argc)
+{
+     int res = BISECT_OK;
+     struct strbuf command = STRBUF_INIT;
+     struct strvec args = STRVEC_INIT;
+     struct strvec run_args = STRVEC_INIT;
+     int exit = 0;
+
+     if (bisect_next_check(terms, NULL))
+             return BISECT_FAILED;
+
+     if (argc)
+             sq_quote_argv(&command, argv);
+     else
+             return BISECT_FAILED;

Do we want to say something helpful here, e.g. _("bisect run failed: no
command provided.")?

Ok, noted

quoted

+
+     strvec_push(&run_args, command.buf);
+
+     while (1) {
+             strvec_clear(&args);
+             exit = 1;
+
+             printf(_("running %s"), command.buf);
+             res = run_command_v_opt(run_args.v, RUN_USING_SHELL);
+
+             if (res < 0 || 128 <= res) {
+                     error(_("bisect run failed: exit code %d from"
+                             " '%s' is < 0 or >= 128"), res, command.buf);
+                     strbuf_release(&command);
+                     return res;
+             }
+
+             if (res == 125)
+                     strvec_push(&args, "skip");
+             else if (res > 0)
+                     strvec_push(&args, terms->term_bad);
+             else
+                     strvec_push(&args, terms->term_good);
+
+             res = bisect_state(terms, args.v, args.nr);

Since `args.nr` will always be 1, it would probably be better to use
something like this:

                const char *new_state;

                [...]
                if (res == 125)
                        new_state = "skip";
                else
                        new_state = res > 0 ?
                                terms->term_bad : terms->term_good;

                res = bisect_state(terms, &new_state, 1);

Yes, indeed. I will change it.

Also: I think at this stage, an equivalent to `cat "$GIT_DIR/BISECT_RUN"`
is missing.

In the previous patch series (v3), I implemented the equivalent to the
cat command but I understood
reviewers wanted to print the output to the user, so I reverted my
changes for this version.
https://lore.kernel.org/git/20210411095538.34129-4-mirucam@gmail.com/ (local)

quoted

+
+             if (res == BISECT_ONLY_SKIPPED_LEFT)
+                     error(_("bisect run cannot continue any more"));
+             else if (res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) {
+                     printf(_("bisect run success"));
+                     res = BISECT_OK;
+             } else if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
+                     printf(_("bisect found first bad commit"));
+                     res = BISECT_OK;
+             } else if (res) {
+                     error(_("bisect run failed:'git bisect--helper --bisect-state"
+                     " %s' exited with error code %d"), args.v[0], res);
+             } else {
+                     exit = 0;

Since the only purpose of `exit` seems to be that the loop should continue
if `exit` is set to 0, and it is only set here, how about doing away with
the variable altogether and writing `continue;` instead of `exit = 0;`?
Then the conditional block below does not need to be conditional.

Noted.

Other than that: well done!

Thank you for reviewing!,
Miriam

Ciao,
Dscho

quoted

+             }
+
+             if (exit) {
+                     strbuf_release(&command);
+                     strvec_clear(&args);
+                     strvec_clear(&run_args);
+                     return res;
+             }
+     }
+}
+
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
      enum {

@@ -1089,6 +1155,7 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
              BISECT_REPLAY,
              BISECT_SKIP,
              BISECT_VISUALIZE,
+             BISECT_RUN,
      } cmdmode = 0;
      int res = 0, nolog = 0;
      struct option options[] = {

@@ -1112,6 +1179,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
                       N_("skip some commits for checkout"), BISECT_SKIP),
              OPT_CMDMODE(0, "bisect-visualize", &cmdmode,
                       N_("visualize the bisection"), BISECT_VISUALIZE),
+             OPT_CMDMODE(0, "bisect-run", &cmdmode,
+                      N_("use <cmd>... to automatically bisect."), BISECT_RUN),
              OPT_BOOL(0, "no-log", &nolog,
                       N_("no log for BISECT_WRITE")),
              OPT_END()

@@ -1177,6 +1246,12 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
              get_terms(&terms);
              res = bisect_visualize(&terms, argv, argc);
              break;
+     case BISECT_RUN:
+             if (!argc)
+                     return error(_("bisect run failed: no command provided."));
+             get_terms(&terms);
+             res = bisect_run(&terms, argv, argc);
+             break;
      default:
              BUG("unknown subcommand %d", cmdmode);
      }

diff --git a/git-bisect.sh b/git-bisect.sh
index 95f7f3fb8c..e83d011e17 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh

@@ -39,66 +39,6 @@ _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 TERM_BAD=bad
 TERM_GOOD=good

-bisect_run () {
-     git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD fail || exit
-
-     test -n "$*" || die "$(gettext "bisect run failed: no command provided.")"
-
-     while true
-     do
-             command="$@"
-             eval_gettextln "running \$command"
-             "$@"
-             res=$?
-
-             # Check for really bad run error.
-             if [ $res -lt 0 -o $res -ge 128 ]
-             then
-                     eval_gettextln "bisect run failed:
-exit code \$res from '\$command' is < 0 or >= 128" >&2
-                     exit $res
-             fi
-
-             # Find current state depending on run success or failure.
-             # A special exit code of 125 means cannot test.
-             if [ $res -eq 125 ]
-             then
-                     state='skip'
-             elif [ $res -gt 0 ]
-             then
-                     state="$TERM_BAD"
-             else
-                     state="$TERM_GOOD"
-             fi
-
-             git bisect--helper --bisect-state $state >"$GIT_DIR/BISECT_RUN"
-             res=$?
-
-             cat "$GIT_DIR/BISECT_RUN"
-
-             if sane_grep "first $TERM_BAD commit could be any of" "$GIT_DIR/BISECT_RUN" \
-                     >/dev/null
-             then
-                     gettextln "bisect run cannot continue any more" >&2
-                     exit $res
-             fi
-
-             if [ $res -ne 0 ]
-             then
-                     eval_gettextln "bisect run failed:
-'bisect-state \$state' exited with error code \$res" >&2
-                     exit $res
-             fi
-
-             if sane_grep "is the first $TERM_BAD commit" "$GIT_DIR/BISECT_RUN" >/dev/null
-             then
-                     gettextln "bisect run success"
-                     exit 0;
-             fi
-
-     done
-}
-
 get_terms () {
      if test -s "$GIT_DIR/BISECT_TERMS"
      then

@@ -137,7 +77,7 @@ case "$#" in
      log)
              git bisect--helper --bisect-log || exit ;;
      run)
-             bisect_run "$@" ;;
+             git bisect--helper --bisect-run "$@" || exit;;
      terms)
              git bisect--helper --bisect-terms "$@" || exit;;
      *)
--

2.29.2