Re: [PATCH v5 5/6] bisect--helper: reimplement `bisect_run` shell function in C
Hi Miriam,
On Fri, 20 Aug 2021, Miriam Rubio wrote:
Show 54 quoted lines
> From: Tanushree Tumane <tanushreetumane@gmail.com>
>
> 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 <chriscool@tuxfamily.org>
> Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
> Signed-off-by: Miriam Rubio <mirucam@gmail.com>
> ---
> builtin/bisect--helper.c | 102 +++++++++++++++++++++++++++++++++++++++
> git-bisect.sh | 62 +-----------------------
> 2 files changed, 103 insertions(+), 61 deletions(-)
>
> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
> index 1e118a966a..8d33c809aa 100644
> --- a/builtin/bisect--helper.c
> +++ b/builtin/bisect--helper.c
> @@ -18,6 +18,7 @@ static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG")
> static GIT_PATH_FUNC(git_path_head_name, "head-name")
> static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
> static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT")
> +static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN")
>
> static const char * const git_bisect_helper_usage[] = {
> N_("git bisect--helper --bisect-reset [<commit>]"),
> @@ -31,6 +32,7 @@ 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
> };
>
> @@ -144,6 +146,25 @@ static int append_to_file(const char *path, const char *format, ...)
> return res;
> }
>
> +static int print_file_to_stdout(const char *path)
> +{
> + FILE *fp;
> + char c;
> +
> + fp = fopen(path, "r");
> + if (!fp)
> + return error_errno(_("cannot open file '%s' in read mode"), path);
> +
> + c = fgetc(fp);
> + while (c != EOF) {
> + printf ("%c", c);
> + c = fgetc(fp);
> + }
> +
> + fclose(fp);Rather than reading byte for byte (even if buffered), how about using `copy_fd()`? Something like
int fd = open(path, O_RDONLY), ret = 0;
if (fd < 0)
return error_errno(_("cannot open file '%s' for reading"), path);
if (copy_fd(fd, 1) < 0)
ret = error_errno(_("failed to read '%s'"), path);
close(fd);
return ret;Show 47 quoted lines
> + return 0;
> +}
> +
> static int check_term_format(const char *term, const char *orig_term)
> {
> int res;
> @@ -1075,6 +1096,78 @@ 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;
> + const char *new_state;
> + int temporary_stdout_fd, saved_stdout;
> +
> + if (bisect_next_check(terms, NULL))
> + return BISECT_FAILED;
> +
> + if (argc)
> + sq_quote_argv(&command, argv);
> + else {
> + error(_("bisect run failed: no command provided."));
> + return BISECT_FAILED;
> + }
> +
> + strvec_push(&run_args, command.buf);
> +
> + while (1) {
> + strvec_clear(&args);
> +
> + printf(_("running %s\n"), 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)
> + new_state = "skip";
> + else new_state = res > 0 ? terms->term_bad : terms->term_good;I do not care _all_ that much about formatting, but I think others on this list do, and might point out that the `else` wants to live on its own line.
> + temporary_stdout_fd = open(git_path_bisect_run(), O_CREAT | O_WRONLY | O_TRUNC, 0666);
> + saved_stdout = dup(1);
> + dup2(temporary_stdout_fd, 1);
This temporary redirection looks a bit iffy. I wonder whether there is a way to tell `bisect_state()` to print to a given file descriptor, _in addition to_ `stdout`? That would also make `print_file_to_stdout()` obsolete.
What calls exactly are making that print to `stdout` anyway?
This is my only remaining issue with the current 5/6.
Thank you, Dscho
Show 148 quoted lines
> +
> + res = bisect_state(terms, &new_state, 1);
> +
> + dup2(saved_stdout, 1);
> + close(saved_stdout);
> + close(temporary_stdout_fd);
> +
> + print_file_to_stdout(git_path_bisect_run());
> +
> + 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 {
> + continue;
> + }
> +
> + 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 +1182,7 @@ 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 +1206,8 @@ 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 +1273,12 @@ 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
>
>
Miriam Rubio