lttng: list valid condition / action names if missing or unknown

simark · jgalar · commit ef9ff9cb5ff4 · 2021-12-15T19:18:10.000-05:00
I think it would be helpful to the user to list the condition and action names, when the condition or action name is missing or unrecognized. This patch implements that, here are some examples of the result: $ lttng add-trigger --action notify --condition Error: While parsing argument #4: Missing required argument for option `--condition` Error: Valid condition names are: Error: event-rule-matches $ lttng add-trigger --action notify --condition pouet Error: While parsing argument #5: Unknown condition name 'pouet' Error: Valid condition names are: Error: event-rule-matches $ lttng add-trigger --condition event-rule-matches --action Error: While parsing argument #4: Missing required argument for option `--action` Error: Valid action names are: Error: notify $ lttng add-trigger --condition event-rule-matches --action pouet Error: While parsing argument #5: Unknown action name: pouet Error: Valid action names are: Error: notify To achieve this, add a new optional out argument to parse_next_item, to allow the caller to get the argpar_error object if a parsing error happened. Because of this, the callers must now be able to differentiate parsing error from memory errors: in the latter case, no argpar_error object is returned. So, add a new PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY status, and make users of parse_next_item handle it. In the add-trigger command implementation, handle the "missing opt arg" case of OPT_ACTION and OPT_CONDITION specially to print the valid names. Handle unknown names in parse_action and parse_condition. Add a test for an unknown action name, it seems to be missing. Change the error message format slightly to make it match the messages for unknown condition names. Change-Id: I4c13cecacb3a2ff4367e391c4aba0d05f1f28f22 Signed-off-by: Simon Marchi <simon.marchi@efficios.com> Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
diff --git a/src/bin/lttng/commands/add_trigger.cpp b/src/bin/lttng/commands/add_trigger.cpp
@@ -697,8 +697,9 @@ struct parse_event_rule_res parse_event_rule(int *argc, const char ***argv,
 		enum parse_next_item_status status;
 
 		status = parse_next_item(argpar_iter, &argpar_item,
-			argc_offset, *argv, false, NULL);
-		if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
+			argc_offset, *argv, false, NULL, NULL);
+		if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
+				status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 			goto error;
 		} else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 			break;
@@ -1414,6 +1415,18 @@ struct condition_descr condition_descrs[] = {
 	{ "event-rule-matches", handle_condition_event },
 };
 
+static
+void print_valid_condition_names(void)
+{
+	unsigned int i;
+
+	ERR("Valid condition names are:");
+
+	for (i = 0; i < ARRAY_SIZE(condition_descrs); ++i) {
+		ERR("  %s", condition_descrs[i].name);
+	}
+}
+
 static
 struct lttng_condition *parse_condition(const char *condition_name, int *argc,
 		const char ***argv, int argc_offset, int orig_arg_index,
@@ -1433,6 +1446,7 @@ struct lttng_condition *parse_condition(const char *condition_name, int *argc,
 	if (!descr) {
 		ERR(WHILE_PARSING_ARG_N_ARG_FMT "Unknown condition name '%s'",
 			orig_arg_index + 1, orig_arg, condition_name);
+		print_valid_condition_names();
 		goto error;
 	}
 
@@ -1547,9 +1561,10 @@ struct lttng_action *handle_action_notify(int *argc, const char ***argv,
 		enum parse_next_item_status status;
 
 		status = parse_next_item(argpar_iter, &argpar_item,
-			argc_offset, *argv, false,
+			argc_offset, *argv, false, NULL,
 			"While parsing `notify` action:");
-		if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
+		if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
+				status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 			goto error;
 		} else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 			break;
@@ -1653,9 +1668,10 @@ static struct lttng_action *handle_action_simple_session_with_policy(int *argc,
 		enum parse_next_item_status status;
 
 		status = parse_next_item(argpar_iter, &argpar_item, argc_offset,
-			*argv, false,
+			*argv, false, NULL,
 			"While parsing `%s` action:", action_name);
-		if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
+		if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
+				status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 			goto error;
 		} else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 			break;
@@ -1813,8 +1829,9 @@ struct lttng_action *handle_action_snapshot_session(int *argc,
 		enum parse_next_item_status status;
 
 		status = parse_next_item(argpar_iter, &argpar_item, argc_offset,
-			*argv, false, "While parsing `snapshot` action:");
-		if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
+			*argv, false, NULL, "While parsing `snapshot` action:");
+		if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
+				status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 			goto error;
 		} else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 			break;
@@ -2097,6 +2114,18 @@ struct action_descr action_descrs[] = {
 	{ "snapshot-session", handle_action_snapshot_session },
 };
 
+static
+void print_valid_action_names(void)
+{
+	unsigned int i;
+
+	ERR("Valid action names are:");
+
+	for (i = 0; i < ARRAY_SIZE(condition_descrs); ++i) {
+		ERR("  %s", action_descrs[i].name);
+	}
+}
+
 static
 struct lttng_action *parse_action(const char *action_name, int *argc,
 		const char ***argv, int argc_offset, int orig_arg_index,
@@ -2114,8 +2143,9 @@ struct lttng_action *parse_action(const char *action_name, int *argc,
 	}
 
 	if (!descr) {
-		ERR(WHILE_PARSING_ARG_N_ARG_FMT "Unknown action name: %s",
+		ERR(WHILE_PARSING_ARG_N_ARG_FMT "Unknown action name '%s'",
 			orig_arg_index + 1, orig_arg, action_name);
+		print_valid_action_names();
 		goto error;
 	}
 
@@ -2160,6 +2190,7 @@ int cmd_add_trigger(int argc, const char **argv)
 	struct lttng_dynamic_pointer_array actions;
 	struct argpar_iter *argpar_iter = NULL;
 	const struct argpar_item *argpar_item = NULL;
+	const struct argpar_error *argpar_error = NULL;
 	struct lttng_action *action_list = NULL;
 	struct lttng_action *action = NULL;
 	struct lttng_trigger *trigger = NULL;
@@ -2211,8 +2242,22 @@ int cmd_add_trigger(int argc, const char **argv)
 		}
 
 		status = parse_next_item(argpar_iter, &argpar_item,
-			argc - my_argc, my_argv, true, NULL);
+			argc - my_argc, my_argv, true, &argpar_error, NULL);
 		if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
+
+			if (argpar_error_type(argpar_error) ==
+					ARGPAR_ERROR_TYPE_MISSING_OPT_ARG) {
+				int opt_id = argpar_error_opt_descr(argpar_error, NULL)->id;
+
+				if (opt_id == OPT_CONDITION) {
+					print_valid_condition_names();
+				} else if (opt_id == OPT_ACTION) {
+					print_valid_action_names();
+				}
+			}
+
+			goto error;
+		} else if (status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 			goto error;
 		} else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 			break;
@@ -2432,6 +2477,7 @@ int cmd_add_trigger(int argc, const char **argv)
 	}
 
 cleanup:
+	argpar_error_destroy(argpar_error);
 	argpar_iter_destroy(argpar_iter);
 	argpar_item_destroy(argpar_item);
 	lttng_dynamic_pointer_array_reset(&actions);
diff --git a/src/bin/lttng/commands/list_triggers.cpp b/src/bin/lttng/commands/list_triggers.cpp
@@ -1336,8 +1336,9 @@ int cmd_list_triggers(int argc, const char **argv)
 		enum parse_next_item_status status;
 
 		status = parse_next_item(argpar_iter, &argpar_item, 1, argv,
-			true, NULL);
-		if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
+			true, NULL, NULL);
+		if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
+				status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 			goto error;
 		} else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 			break;
diff --git a/src/bin/lttng/commands/remove_trigger.cpp b/src/bin/lttng/commands/remove_trigger.cpp
@@ -112,8 +112,9 @@ int cmd_remove_trigger(int argc, const char **argv)
 		enum parse_next_item_status status;
 
 		status = parse_next_item(argpar_iter, &argpar_item, 1, argv,
-			true, NULL);
-		if (status == PARSE_NEXT_ITEM_STATUS_ERROR) {
+			true, NULL, NULL);
+		if (status == PARSE_NEXT_ITEM_STATUS_ERROR ||
+				status == PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY) {
 			goto error;
 		} else if (status == PARSE_NEXT_ITEM_STATUS_END) {
 			break;
diff --git a/src/common/argpar-utils/argpar-utils.c b/src/common/argpar-utils/argpar-utils.c
@@ -120,6 +120,7 @@ char *format_arg_error_v(const struct argpar_error *error, int argc_offset,
 enum parse_next_item_status parse_next_item(struct argpar_iter *iter,
 		const struct argpar_item **item, int argc_offset,
 		const char **argv, bool unknown_opt_is_error,
+		const struct argpar_error **error_out,
 		const char *context_fmt, ...)
 {
 	enum argpar_iter_next_status status;
@@ -132,7 +133,7 @@ enum parse_next_item_status parse_next_item(struct argpar_iter *iter,
 	switch (status) {
 	case ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY:
 		ERR("Failed to get next argpar item.");
-		ret = PARSE_NEXT_ITEM_STATUS_ERROR;
+		ret = PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY;
 		break;
 	case ARGPAR_ITER_NEXT_STATUS_ERROR:
 	{
@@ -170,6 +171,12 @@ enum parse_next_item_status parse_next_item(struct argpar_iter *iter,
 		abort();
 	}
 
+	if (error_out) {
+		argpar_error_destroy(*error_out);
+		*error_out = error;
+		error = NULL;
+	}
+
 	argpar_error_destroy(error);
 
 	return ret;
diff --git a/src/common/argpar-utils/argpar-utils.h b/src/common/argpar-utils/argpar-utils.h
@@ -25,6 +25,7 @@ enum parse_next_item_status
 	PARSE_NEXT_ITEM_STATUS_OK = 0,
 	PARSE_NEXT_ITEM_STATUS_END = 1,
 	PARSE_NEXT_ITEM_STATUS_ERROR = -1,
+	PARSE_NEXT_ITEM_STATUS_ERROR_MEMORY = -2,
 };
 
 /*
@@ -45,11 +46,16 @@ enum parse_next_item_status
  *
  * If `unknown_opt_is_error` is true, an unknown option is considered an error.
  * Otherwise, it is considered as the end of the argument list.
+ *
+ * If `error_out` is given and PARSE_NEXT_ITEM_STATUS_ERROR is returned, set
+ * `*error_out` to the argpar_error object corresponding to the error.  The
+ * caller must free the object with `argpar_error_destroy`.
  */
-ATTR_FORMAT_PRINTF(6, 7)
+ATTR_FORMAT_PRINTF(7, 8)
 enum parse_next_item_status parse_next_item(struct argpar_iter *iter,
 		const struct argpar_item **item, int argc_offset,
 		const char **argv, bool unknown_opt_is_error,
+		const struct argpar_error **error_out,
 		const char *context_fmt, ...);
 
 #ifdef __cplusplus
diff --git a/tests/regression/tools/trigger/test_add_trigger_cli b/tests/regression/tools/trigger/test_add_trigger_cli
@@ -23,7 +23,7 @@ TESTDIR="$CURDIR/../../.."
 # shellcheck source=../../../utils/utils.sh
 source "$TESTDIR/utils/utils.sh"
 
-plan_tests 289
+plan_tests 295
 
 FULL_LTTNG_BIN="${TESTDIR}/../src/bin/lttng/${LTTNG_BIN}"
 
@@ -450,13 +450,19 @@ test_failure "invalid argument to --rate-policy: unknown policy type" \
 
 # `--condition` failures
 test_failure "missing args after --condition" \
-	"Error: While parsing argument #2 (\`--condition\`): Missing required argument for option \`--condition\`" \
+	"Error: While parsing argument #2 (\`--condition\`): Missing required argument for option \`--condition\`
+Error: Valid condition names are:
+Error:   event-rule-matches" \
 	--condition
 test_failure "unknown --condition" \
-	"Error: While parsing argument #2 (\`--condition\`): Unknown condition name 'zoofest'" \
+	"Error: While parsing argument #2 (\`--condition\`): Unknown condition name 'zoofest'
+Error: Valid condition names are:
+Error:   event-rule-matches" \
 	--condition zoofest
 test_failure "unknown --condition=" \
-	"Error: While parsing argument #2 (\`--condition=zoofest\`): Unknown condition name 'zoofest'" \
+	"Error: While parsing argument #2 (\`--condition=zoofest\`): Unknown condition name 'zoofest'
+Error: Valid condition names are:
+Error:   event-rule-matches" \
 	--condition=zoofest
 
 # `--condition event-rule-matches` failures
@@ -551,10 +557,26 @@ test_failure "--condition event-rule-matches --capture: missing colon in app-spe
 
 # `--action` failures
 test_failure "missing args after --action" \
-	"Error: While parsing argument #5 (\`--action\`): Missing required argument for option \`--action\`" \
+	"Error: While parsing argument #5 (\`--action\`): Missing required argument for option \`--action\`
+Error: Valid action names are:
+Error:   notify" \
 	--condition event-rule-matches --type=user \
 	--action
 
+test_failure "unknown --action" \
+	"Error: While parsing argument #5 (\`--action\`): Unknown action name 'zoofest'
+Error: Valid action names are:
+Error:   notify" \
+	--condition event-rule-matches --type=user \
+	--action zoofest
+
+test_failure "unknown --action=" \
+	"Error: While parsing argument #5 (\`--action=zoofest\`): Unknown action name 'zoofest'
+Error: Valid action names are:
+Error:   notify" \
+	--condition event-rule-matches --type=user \
+	--action=zoofest
+
 # `--action notify` failures
 test_failure "extra arg after --action notify" \
 	"Error: Unexpected argument \`bob\`." \
