[PATCH v2 1/5] parseopt: extract subcommand handling from parse_options_step()

From

JSJiamu Sun <39@barroit.sh>

Date

Mar 8, 2026, 23:16 UTC

Message-ID

<SY0P300MB08017CA1F4E85F606B8FAE28CE78A@SY0P300MB0801.AUSP300.PROD.OUTLOOK.COM>

In-Reply-To

<SY0P300MB08013E35DCA8FC31B0662125CE78A@SY0P300MB0801.AUSP300.PROD.OUTLOOK.COM>

Signed-off-by: Jiamu Sun <39@barroit.sh>
---
 parse-options.c | 75 ++++++++++++++++++++++++++-----------------------
 1 file changed, 40 insertions(+), 35 deletions(-)

diff --git a/parse-options.c b/parse-options.c
index c9cafc21b903..6bb0c5697099 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -605,17 +605,43 @@ static enum parse_opt_result parse_nodash_opt(struct parse_opt_ctx_t *p,
 	return PARSE_OPT_ERROR;
 }
 
-static enum parse_opt_result parse_subcommand(const char *arg,
-					      const struct option *options)
+static int parse_subcommand(const char *arg, const struct option *options)
 {
-	for (; options->type != OPTION_END; options++)
-		if (options->type == OPTION_SUBCOMMAND &&
-		    !strcmp(options->long_name, arg)) {
-			*(parse_opt_subcommand_fn **)options->value = options->subcommand_fn;
-			return PARSE_OPT_SUBCOMMAND;
-		}
+	for (; options->type != OPTION_END; options++) {
+		if (options->type != OPTION_SUBCOMMAND ||
+		    strcmp(options->long_name, arg))
+			continue;
 
-	return PARSE_OPT_UNKNOWN;
+		parse_opt_subcommand_fn **opt_val = options->value;
+		*opt_val = options->subcommand_fn;
+
+		return 0;
+	}
+
+	return -1;
+}
+
+static enum parse_opt_result handle_subcommand(struct parse_opt_ctx_t *ctx,
+					       const char *arg,
+					       const struct option *options,
+					       const char * const usagestr[])
+{
+	int err = parse_subcommand(arg, options);
+
+	if (!err)
+		return PARSE_OPT_SUBCOMMAND;
+
+	/*
+	 * arg is neither a short or long option nor a subcommand.  Since this
+	 * command has a default operation mode, we have to treat this arg and
+	 * all remaining args as args meant to that default operation mode.
+	 * So we are done parsing.
+	 */
+	if (ctx->flags & PARSE_OPT_SUBCOMMAND_OPTIONAL)
+		return PARSE_OPT_DONE;
+
+	error(_("unknown subcommand: `%s'"), arg);
+	usage_with_options(usagestr, options);
 }
 
 static void check_typos(const char *arg, const struct option *options)
@@ -990,37 +1016,16 @@ enum parse_opt_result parse_options_step(struct parse_opt_ctx_t *ctx,
 		if (*arg != '-' || !arg[1]) {
 			if (parse_nodash_opt(ctx, arg, options) == 0)
 				continue;
+
 			if (!ctx->has_subcommands) {
 				if (ctx->flags & PARSE_OPT_STOP_AT_NON_OPTION)
 					return PARSE_OPT_NON_OPTION;
 				ctx->out[ctx->cpidx++] = ctx->argv[0];
 				continue;
-			}
-			switch (parse_subcommand(arg, options)) {
-			case PARSE_OPT_SUBCOMMAND:
-				return PARSE_OPT_SUBCOMMAND;
-			case PARSE_OPT_UNKNOWN:
-				if (ctx->flags & PARSE_OPT_SUBCOMMAND_OPTIONAL)
-					/*
-					 * arg is neither a short or long
-					 * option nor a subcommand.  Since
-					 * this command has a default
-					 * operation mode, we have to treat
-					 * this arg and all remaining args
-					 * as args meant to that default
-					 * operation mode.
-					 * So we are done parsing.
-					 */
-					return PARSE_OPT_DONE;
-				error(_("unknown subcommand: `%s'"), arg);
-				usage_with_options(usagestr, options);
-			case PARSE_OPT_COMPLETE:
-			case PARSE_OPT_HELP:
-			case PARSE_OPT_ERROR:
-			case PARSE_OPT_DONE:
-			case PARSE_OPT_NON_OPTION:
-				/* Impossible. */
-				BUG("parse_subcommand() cannot return these");
+
+			} else {
+				return handle_subcommand(ctx, arg,
+							 options, usagestr);
 			}
 		}
 

-- 
2.53.0