tests/cmake: add tests for syscall generation scripts

This commit adds tests for whitespace in syscall declaration function
signatures and signatures without parameters.

Signed-off-by: Loek Le Blansch <loek.le-blansch.pv@renesas.com>

Author: lonkaars

tests/cmake/syscalls/CMakeLists.txt

@@ -0,0 +1,6 @@
+# Copyright (c) 2025 Renesas Electronics Corporation
+# SPDX-License-Identifier: Apache-2.0
+cmake_minimum_required(VERSION 3.28)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(app C)
+target_sources(app PRIVATE main.c)

tests/cmake/syscalls/main.c

@@ -0,0 +1,8 @@
+/*
+ * Copyright (c) 2025 Renesas Electronics Corporation
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "main.h"
+
+int main(void) { return 0; }

tests/cmake/syscalls/main.h

@@ -0,0 +1,20 @@
+#pragma once
+
+/*
+ * Copyright (c) 2025 Renesas Electronics Corporation
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/syscall.h>
+
+/* Newline between return type and function name */
+/* clang-format off */
+__syscall void
+test_wrapped(int foo);
+/* clang-format on */
+
+/* Empty parameters (macro used to silence checkpatch.pl) */
+#define EMPTY
+__syscall void test_empty(EMPTY);
+
+#include <zephyr/syscalls/main.h>

tests/cmake/syscalls/prj.conf

@@ -0,0 +1,3 @@
+# Copyright (c) 2025 Renesas Electronics Corporation
+# SPDX-License-Identifier: Apache-2.0
+CONFIG_APPLICATION_DEFINED_SYSCALL=y

tests/cmake/syscalls/testcase.yaml

@@ -0,0 +1,6 @@
+# Copyright (c) 2025 Renesas Electronics Corporation
+# SPDX-License-Identifier: Apache-2.0
+tests:
+  buildsystem.syscalls:
+    build_only: true
+    platform_allow: native_sim