Use enum for C++ to avoid macro pitfalls (#7926)

cores/esp32/esp32-hal-uart.h

@@ -25,6 +25,34 @@ extern "C" {
 #include "freertos/FreeRTOS.h"
 #include "freertos/queue.h"
 
+#ifdef __cplusplus
+enum SerialConfig {
+SERIAL_5N1 = 0x8000010,
+SERIAL_6N1 = 0x8000014,
+SERIAL_7N1 = 0x8000018,
+SERIAL_8N1 = 0x800001c,
+SERIAL_5N2 = 0x8000030,
+SERIAL_6N2 = 0x8000034,
+SERIAL_7N2 = 0x8000038,
+SERIAL_8N2 = 0x800003c,
+SERIAL_5E1 = 0x8000012,
+SERIAL_6E1 = 0x8000016,
+SERIAL_7E1 = 0x800001a,
+SERIAL_8E1 = 0x800001e,
+SERIAL_5E2 = 0x8000032,
+SERIAL_6E2 = 0x8000036,
+SERIAL_7E2 = 0x800003a,
+SERIAL_8E2 = 0x800003e,
+SERIAL_5O1 = 0x8000013,
+SERIAL_6O1 = 0x8000017,
+SERIAL_7O1 = 0x800001b,
+SERIAL_8O1 = 0x800001f,
+SERIAL_5O2 = 0x8000033,
+SERIAL_6O2 = 0x8000037,
+SERIAL_7O2 = 0x800003b,
+SERIAL_8O2 = 0x800003f
+};
+#else
 #define SERIAL_5N1 0x8000010
 #define SERIAL_6N1 0x8000014
 #define SERIAL_7N1 0x8000018
@@ -49,6 +77,7 @@ extern "C" {
 #define SERIAL_6O2 0x8000037
 #define SERIAL_7O2 0x800003b
 #define SERIAL_8O2 0x800003f
+#endif // __cplusplus
 
 // These are Hardware Flow Contol possible usage
 // equivalent to UDF enum uart_hw_flowcontrol_t from