Merge branch 'bugfix/fix_atomics_incompatibility_cpp' into 'main'

fix: atomics incompatibility cpp

See merge request idf/esp-modbus!169

modbus/mb_objects/common/mb_port_types.h

@@ -13,7 +13,7 @@
 #endif
 
 // Workaround for atomics incompatibility issue under CPP.
-#if defined(__cplusplus) && (ESP_IDF_VERSION <= ESP_IDF_VERSION_VAL(5, 0, 0))
+#if defined(__cplusplus)
 #include <atomic>
 #define _Atomic(T) std::atomic<T>
 #define atomic_int int

test_apps/cpp/modbus_serial_cpp_test/main/CMakeLists.txt

@@ -1,9 +1,12 @@
 set(PROJECT_NAME "mb_serial_cpp")
 
 idf_component_register(SRCS "serial_test.cpp"
-                    REQUIRES esp-modbus nvs_flash esp_event esp_timer lwip
+                    REQUIRES esp-modbus esp_common nvs_flash esp_event esp_timer lwip
                     INCLUDE_DIRS ".")
 
+# Explicitly use C++17 so we can get std::atomic support for the workaround in mb_port_types.h
+target_compile_features(${COMPONENT_LIB} PUBLIC cxx_std_17)
+
 # Workaround to avoid static analysis false positives for some components.
 if(CONFIG_FMB_COMPILER_STATIC_ANALYZER_ENABLE AND CMAKE_C_COMPILER_ID STREQUAL "GNU")
     target_compile_options(${COMPONENT_LIB} PRIVATE "-fanalyzer")

test_apps/cpp/modbus_serial_cpp_test/main/serial_test.cpp

@@ -1,13 +1,17 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 #include "esp_log.h"
+#include "esp_system.h"
 
 #include "sdkconfig.h"
 #include "mbcontroller.h"
 
+#include "esp_idf_version.h"
+#include "mb_port_types.h"      // atomic layout and C++ compatibility
+
 #define TEST_PORT_NUM           (uart_port_t)1
 #define TEST_SPEED              115200
 
@@ -167,8 +171,20 @@ static_assert(
     "CPP atomic int types are not layout compatible with int"
 );
 
+static int check_atomic_cpp_instantiation(void)
+{
+    // Check atomic support: mb_uid_info_t.state is _Atomic(int) in C, std::atomic<int> in C++
+    mb_uid_info_t addr_info = {};
+    addr_info.index = 1;
+    atomic_store(&(addr_info.state), 23);
+    return atomic_load(&addr_info.state);
+}
+
 extern "C" void app_main(void)
 {
+    ESP_LOGI(TAG, "mb_port_types.h C++ atomics test passed (IDF compatible), %d, %d, %s",
+             check_atomic_cpp_instantiation(), (int)ESP_IDF_VERSION, esp_get_idf_version());
+
     // Initialization of device peripheral and objects
     ESP_LOGI(TAG, "Setup master cpp....");
     ESP_ERROR_CHECK(master_serial_init(&pmaster_handle));