shell: Add APIs to set number of arguments

This allows the shell core to perform precheck before calling the
handler which then can assume the number of arguments is correct.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

doc/subsystems/shell/shell.rst

@@ -78,7 +78,10 @@ Use the following macros for adding shell commands:
 
 * :c:macro:`SHELL_CMD_REGISTER` - Create root command. All root commands must
   have different name.
+* :c:macro:`SHELL_CMD_ARG_REGISTER` - Create root command with arguments.
+  All root commands must have different name.
 * :c:macro:`SHELL_CMD` - Initialize a command.
+* :c:macro:`SHELL_CMD_ARG` - Initialize a command with arguments.
 * :c:macro:`SHELL_CREATE_STATIC_SUBCMD_SET` - Create a static subcommands
   array.
 * :c:macro:`SHELL_SUBCMD_SET_END` - shall be placed as last in

include/shell/shell.h

@@ -71,6 +71,22 @@ struct shell_cmd_entry {
 
 struct shell;
 
+/**
+ * @brief Initializes a shell command arguments
+ *
+ * @param[in] _mandatory Number of mandatory arguments.
+ * @param[in] _optional  Number of optional arguments.
+ */
+#define SHELL_ARG(_mandatory, _optional) {				\
+	.mandatory = _mandatory,					\
+	.optional = _optional,						\
+}
+
+struct shell_static_args {
+	u8_t mandatory; /*!< Number of mandatory arguments. */
+	u8_t optional; /*!< Number of optional arguments. */
+};
+
 /**
  * @brief Shell command handler prototype.
  */
@@ -85,10 +101,37 @@ struct shell_static_entry {
 	const char *help; /*!< Command help string. */
 	const struct shell_cmd_entry *subcmd; /*!< Pointer to subcommand. */
 	shell_cmd_handler handler; /*!< Command handler. */
+	const struct shell_static_args *args; /*!< Command arguments. */
 };
 
 /**
- * @brief Macro for defining and adding a root command (level 0).
+ * @brief Macro for defining and adding a root command (level 0) with
+ * arguments.
+ *
+ * @note Each root command shall have unique syntax.
+ *
+ * @param[in] syntax  Command syntax (for example: history).
+ * @param[in] subcmd  Pointer to a subcommands array.
+ * @param[in] help    Pointer to a command help string.
+ * @param[in] handler Pointer to a function handler.
+ * @param[in] mandatory Number of mandatory arguments.
+ * @param[in] optional  Number of optional arguments.
+ */
+#define SHELL_CMD_ARG_REGISTER(syntax, subcmd, help, handler,		   \
+			       mandatory, optional)			   \
+	static const struct shell_static_entry UTIL_CAT(shell_, syntax) =  \
+	SHELL_CMD_ARG(syntax, subcmd, help, handler, mandatory, optional); \
+	static const struct shell_cmd_entry UTIL_CAT(shell_cmd_, syntax)   \
+	__attribute__ ((section("."					   \
+			STRINGIFY(UTIL_CAT(shell_root_cmd_, syntax)))))	   \
+	__attribute__((used)) = {					   \
+		.is_dynamic = false,					   \
+		.u.entry = &UTIL_CAT(shell_, syntax)			   \
+	}
+
+/**
+ * @brief Macro for defining and adding a root command (level 0) with
+ * arguments.
  *
  * @note Each root command shall have unique syntax.
  *
@@ -140,6 +183,26 @@ struct shell_static_entry {
 		.u.dynamic_get = get			\
 	}
 
+/**
+ * @brief Initializes a shell command with arguments
+ *
+ * @param[in] _syntax  Command syntax (for example: history).
+ * @param[in] _subcmd  Pointer to a subcommands array.
+ * @param[in] _help    Pointer to a command help string.
+ * @param[in] _handler Pointer to a function handler.
+ * @param[in] _mandatory Number of mandatory arguments.
+ * @param[in] _optional Number of optional arguments.
+ */
+#define SHELL_CMD_ARG(_syntax, _subcmd, _help, _handler,		\
+		      _mandatory, _optional) {				\
+	.syntax = (const char *)STRINGIFY(_syntax),			\
+	.subcmd = _subcmd,						\
+	.help  = (const char *)_help,					\
+	.handler = _handler,						\
+	.args = _mandatory ?						\
+	(&(struct shell_static_args) SHELL_ARG(_mandatory, _optional)) : NULL\
+}
+
 /**
  * @brief Initializes a shell command.
  *
@@ -148,12 +211,9 @@ struct shell_static_entry {
  * @param[in] _help    Pointer to a command help string.
  * @param[in] _handler Pointer to a function handler.
  */
-#define SHELL_CMD(_syntax, _subcmd, _help, _handler) {	\
+#define SHELL_CMD(_syntax, _subcmd, _help, _handler) \
-	.syntax = (const char *)STRINGIFY(_syntax),	\
+	SHELL_CMD_ARG(_syntax, _subcmd, _help, _handler, 0, 0)
-	.subcmd = _subcmd,				\
+
-	.help  = (const char *)_help,			\
-	.handler = _handler				\
-}
 
 /**
  * @internal @brief Internal shell state in response to data received from the

subsys/shell/shell.c

@@ -946,6 +946,53 @@ static const struct shell_cmd_entry *root_cmd_find(const char *syntax)
 	return NULL;
 }
 
+static int exec_cmd(const struct shell *shell, size_t argc, char **argv)
+{
+	int ret_val = 0;
+
+	if (shell->ctx->active_cmd.handler == NULL) {
+		if (shell->ctx->active_cmd.help) {
+			shell_help_print(shell, NULL, 0);
+		} else {
+			shell_fprintf(shell, SHELL_ERROR,
+				      SHELL_MSG_SPECIFY_SUBCOMMAND);
+			ret_val = -ENOEXEC;
+			goto clear;
+		}
+	}
+
+	if (shell->ctx->active_cmd.args) {
+		const struct shell_static_args *args;
+
+		args = shell->ctx->active_cmd.args;
+
+		if (args->optional > 0) {
+			/* Check if argc is within allowed range */
+			ret_val = shell_cmd_precheck(shell,
+						     ((argc >= args->mandatory)
+						      &&
+						     (argc <= args->mandatory +
+						     args->optional)),
+						     NULL, 0);
+		} else {
+			/* Perform exact match if there are no optional args */
+			ret_val = shell_cmd_precheck(shell,
+						     (args->mandatory == argc),
+						     NULL, 0);
+		}
+	}
+
+	if (!ret_val) {
+		ret_val = shell->ctx->active_cmd.handler(shell, argc, argv);
+	}
+
+clear:
+	help_flag_clear(shell);
+
+	return ret_val;
+}
+
+
 /* Function is analyzing the command buffer to find matching commands. Next, it
  * invokes the  last recognized command which has a handler and passes the rest
  * of command buffer as arguments.
@@ -959,7 +1006,6 @@ static int shell_execute(const struct shell *shell)
 	size_t cmd_lvl = SHELL_CMD_ROOT_LVL;
 	size_t cmd_with_handler_lvl = 0;
 	bool wildcard_found = false;
-	int ret_val = 0;
 	size_t cmd_idx;
 	size_t argc;
 	char quote;
@@ -1102,25 +1148,10 @@ static int shell_execute(const struct shell *shell)
 	}
 
 	/* Executing the deepest found handler. */
-	if (shell->ctx->active_cmd.handler == NULL) {
+	return exec_cmd(shell, argc - cmd_with_handler_lvl,
-		if (shell->ctx->active_cmd.help) {
-			shell_help_print(shell, NULL, 0);
-		} else {
-			shell_fprintf(shell, SHELL_ERROR,
-				      SHELL_MSG_SPECIFY_SUBCOMMAND);
-			ret_val = -ENOEXEC;
-		}
-	} else {
-		ret_val = shell->ctx->active_cmd.handler(shell,
-						   argc - cmd_with_handler_lvl,
 			&argv[cmd_with_handler_lvl]);
 }
 
-	help_flag_clear(shell);
-
-	return ret_val;
-}
-
 static void shell_transport_evt_handler(enum shell_transport_evt evt_type,
 				      void *context)
 {