[PATCH 11/13] bisect--helper: convert to OPT_SUBCOMMAND_CB()

From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
	"Taylor Blau" <me@ttaylorr.com>,
	"Đoàn Trần Công Danh" <congdanhqx@gmail.com>,
	"SZEDER Gábor" <szeder.dev@gmail.com>,
	"Lukáš Doktor" <ldoktor@redhat.com>,
	"Johannes Schindelin" <Johannes.Schindelin@gmx.de>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Subject: [PATCH 11/13] bisect--helper: convert to OPT_SUBCOMMAND_CB()
Date: Fri,  4 Nov 2022 14:22:48 +0100	[thread overview]
Message-ID: <patch-11.13-d261c32ddd7-20221104T132117Z-avarab@gmail.com> (raw)
In-Reply-To: <cover-00.13-00000000000-20221104T132117Z-avarab@gmail.com>

Have the "bisect--helper" take arguments like "log" instead of "--log"
by using a new OPT_SUBCOMMAND_CB() variant of OPT_SUBCOMMAND(). As
discussed in a preceding commit this allows for using OPT_SUBCOMMAND()
with custom function signatures.

It would be nice to also convert all of the callbacks to use
parse_options(), [1] does. But due to using the new
OPT_SUBCOMMAND_CB() here we can punt on that for now.

Note that we're intentionally leaving the errors which mention
"--bisect-terms", as opposed to "terms". We've been showing that bad
usage information to users for a while now, and don't need to further
enlarge this change now by changing all of "--bisect-" to "" (which
also occurs outside of this context).

This finally fixes the last obscure regression in "git bisect run" in
v2.30.0. We'd previously addressed it eating the "--log" and
"--no-log" options, but d1bbbe45df8 (bisect--helper: reimplement
`bisect_run` shell function in C, 2021-09-13) also had us conflate the
internal-only "--bisect-*" options with user arguments.

1. https://lore.kernel.org/git/e97e187bbec93b47f35e3dd42b4831f1c1d8658d.1661885419.git.gitgitgadget@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 builtin/bisect--helper.c    | 110 ++++++++++++++----------------------
 git-bisect.sh               |  20 +++----
 parse-options.h             |   8 ++-
 t/t6030-bisect-porcelain.sh |   2 +-
 4 files changed, 59 insertions(+), 81 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index e13c60d54b2..b62d3f4d418 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -1314,107 +1314,79 @@ static int bisect_run(struct bisect_terms *terms,  int argc,
 	return res;
 }
 
+typedef int bisect_fn(struct bisect_terms *terms, int argc, const char **argv,
+		      const char *prefix);
+
+static int pick_subcommand_cb(const struct option *option,
+			      const char *arg UNUSED, int unset UNUSED)
+{
+	bisect_fn *fn = (bisect_fn *)option->defval;
+	*(bisect_fn **)option->value = fn;
+	return 0;
+}
+
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
-	enum {
-		BISECT_RESET = 1,
-		BISECT_TERMS,
-		BISECT_START,
-		BISECT_NEXT,
-		BISECT_STATE,
-		BISECT_LOG,
-		BISECT_REPLAY,
-		BISECT_SKIP,
-		BISECT_VISUALIZE,
-		BISECT_RUN,
-	} cmdmode = 0;
+	bisect_fn *fn = NULL;
 	int res = 0;
+#define OPT_BISECT_SUBCMD(l, v, fn) \
+	OPT_SUBCOMMAND_CB((l), (v), (fn), pick_subcommand_cb)
 	struct option options[] = {
-		OPT_CMDMODE(0, "bisect-reset", &cmdmode,
-			 N_("reset the bisection state"), BISECT_RESET),
-		OPT_CMDMODE(0, "bisect-terms", &cmdmode,
-			 N_("print out the bisect terms"), BISECT_TERMS),
-		OPT_CMDMODE(0, "bisect-start", &cmdmode,
-			 N_("start the bisect session"), BISECT_START),
-		OPT_CMDMODE(0, "bisect-next", &cmdmode,
-			 N_("find the next bisection commit"), BISECT_NEXT),
-		OPT_CMDMODE(0, "bisect-state", &cmdmode,
-			 N_("mark the state of ref (or refs)"), BISECT_STATE),
-		OPT_CMDMODE(0, "bisect-log", &cmdmode,
-			 N_("list the bisection steps so far"), BISECT_LOG),
-		OPT_CMDMODE(0, "bisect-replay", &cmdmode,
-			 N_("replay the bisection process from the given file"), BISECT_REPLAY),
-		OPT_CMDMODE(0, "bisect-skip", &cmdmode,
-			 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_BISECT_SUBCMD("reset", &fn, bisect_reset),
+		OPT_BISECT_SUBCMD("terms", &fn, bisect_terms),
+		OPT_BISECT_SUBCMD("start", &fn, bisect_start),
+		OPT_BISECT_SUBCMD("next", &fn, bisect_next),
+		OPT_BISECT_SUBCMD("state", &fn, bisect_state),
+		OPT_BISECT_SUBCMD("log", &fn, bisect_log),
+		OPT_BISECT_SUBCMD("replay", &fn, bisect_replay),
+		OPT_BISECT_SUBCMD("skip", &fn, bisect_skip),
+		OPT_BISECT_SUBCMD("visualize", &fn, bisect_visualize),
+		OPT_BISECT_SUBCMD("run", &fn, bisect_run),
 		OPT_END()
 	};
+#undef OPT_BISECT_SUBCMD
 	struct bisect_terms terms = { .term_good = NULL, .term_bad = NULL };
 
 	argc = parse_options(argc, argv, prefix, options, git_bisect_usage,
-			     PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_UNKNOWN_OPT);
+			     0);
 
-	if (!cmdmode)
-		usage_with_options(git_bisect_usage, options);
+	argc--;
+	argv++;
 
-	switch (cmdmode) {
-	case BISECT_RESET:
+	if (fn == bisect_reset) {
 		if (argc > 1)
 			return error(_("--bisect-reset requires either no argument or a commit"));
-		res = bisect_reset(&terms, argc, argv, prefix);
-		break;
-	case BISECT_TERMS:
+	} else if (fn == bisect_terms) {
 		if (argc > 1)
 			return error(_("--bisect-terms requires 0 or 1 argument"));
-		res = bisect_terms(&terms, argc, argv, prefix);
-		break;
-	case BISECT_START:
+	} else if (fn == bisect_start) {
 		set_terms(&terms, "bad", "good");
-		res = bisect_start(&terms, argc, argv, prefix);
-		break;
-	case BISECT_NEXT:
+	} else if (fn == bisect_next) {
+		get_terms(&terms);
 		if (argc)
 			return error(_("--bisect-next requires 0 arguments"));
-		get_terms(&terms);
-		res = bisect_next(&terms, argc, argv, prefix);
-		break;
-	case BISECT_STATE:
+	} else if (fn == bisect_state) {
 		set_terms(&terms, "bad", "good");
 		get_terms(&terms);
-		res = bisect_state(&terms, argc, argv, prefix);
-		break;
-	case BISECT_LOG:
+	} else if (fn == bisect_log) {
 		if (argc)
 			return error(_("--bisect-log requires 0 arguments"));
-		res = bisect_log(&terms, argc, argv, prefix);
-		break;
-	case BISECT_REPLAY:
+	} else if (fn == bisect_replay) {
 		if (argc != 1)
 			return error(_("no logfile given"));
 		set_terms(&terms, "bad", "good");
-		res = bisect_replay(&terms, argc, argv, prefix);
-		break;
-	case BISECT_SKIP:
+	} else if (fn == bisect_skip) {
 		set_terms(&terms, "bad", "good");
 		get_terms(&terms);
-		res = bisect_skip(&terms, argc, argv, prefix);
-		break;
-	case BISECT_VISUALIZE:
+	} else if (fn == bisect_visualize) {
 		get_terms(&terms);
-		res = bisect_visualize(&terms, argc, argv, prefix);
-		break;
-	case BISECT_RUN:
+	} else if (fn == bisect_run) {
 		if (!argc)
 			return error(_("bisect run failed: no command provided."));
 		get_terms(&terms);
-		res = bisect_run(&terms, argc, argv, prefix);
-		break;
-	default:
-		BUG("unknown subcommand %d", cmdmode);
 	}
+
+	res = fn(&terms, argc, argv, prefix);
 	free_terms(&terms);
 
 	/*
diff --git a/git-bisect.sh b/git-bisect.sh
index 405cf76f2a3..e19847eba0d 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -58,26 +58,26 @@ case "$#" in
 	help)
 		git bisect -h ;;
 	start)
-		git bisect--helper --bisect-start "$@" ;;
+		git bisect--helper start "$@" ;;
 	bad|good|new|old|"$TERM_BAD"|"$TERM_GOOD")
-		git bisect--helper --bisect-state "$cmd" "$@" ;;
+		git bisect--helper state "$cmd" "$@" ;;
 	skip)
-		git bisect--helper --bisect-skip "$@" || exit;;
+		git bisect--helper skip "$@" || exit;;
 	next)
 		# Not sure we want "next" at the UI level anymore.
-		git bisect--helper --bisect-next "$@" || exit ;;
+		git bisect--helper next "$@" || exit ;;
 	visualize|view)
-		git bisect--helper --bisect-visualize "$@" || exit;;
+		git bisect--helper visualize "$@" || exit;;
 	reset)
-		git bisect--helper --bisect-reset "$@" ;;
+		git bisect--helper reset "$@" ;;
 	replay)
-		git bisect--helper --bisect-replay "$@" || exit;;
+		git bisect--helper replay "$@" || exit;;
 	log)
-		git bisect--helper --bisect-log || exit ;;
+		git bisect--helper log || exit ;;
 	run)
-		git bisect--helper --bisect-run "$@" || exit;;
+		git bisect--helper run "$@" || exit;;
 	terms)
-		git bisect--helper --bisect-terms "$@" || exit;;
+		git bisect--helper terms "$@" || exit;;
 	*)
 		usage ;;
 	esac
diff --git a/parse-options.h b/parse-options.h
index 61e3016c3fc..4e32b557174 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -237,10 +237,16 @@ static inline int parse_options_pick_subcommand_cb(const struct option *option,
 	.value = (v), \
 	.flags = (f), \
 	.defval = (intptr_t)(fn), \
-	.subcommand_fn = (fn), \
 	.callback = parse_options_pick_subcommand_cb, \
 }
 #define OPT_SUBCOMMAND(l, v, fn)    OPT_SUBCOMMAND_F((l), (v), (fn), 0)
+#define OPT_SUBCOMMAND_CB(l, v, fn, cb) { \
+	.type = OPTION_SUBCOMMAND, \
+	.long_name = (l), \
+	.value = (v), \
+	.defval = (intptr_t)(fn), \
+	.callback = (cb), \
+}
 
 /*
  * parse_options() will filter out the processed options and leave the
diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index eace0af637e..de47c87a6ff 100755
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -350,7 +350,7 @@ test_expect_success 'git bisect run: args, stdout and stderr: "--log foo --no-lo
 	EOF_ERR
 '
 
-test_expect_failure 'git bisect run: args, stdout and stderr: "--bisect-start" argument' '
+test_expect_success 'git bisect run: args, stdout and stderr: "--bisect-start" argument' '
 	test_bisect_run_args --bisect-start <<-\EOF_ARGS 6<<-EOF_OUT 7<<-\EOF_ERR
 	<--bisect-start>
 	EOF_ARGS
-- 
2.38.0.1452.g710f45c7951

