HAL_SITL: fix sitl build for mac osx

libraries/AP_HAL_SITL/UARTDriver.cpp

@@ -414,8 +414,11 @@ bool UARTDriver::set_unbuffered_writes(bool on) {
     // this has no effect
     unsigned v = fcntl(_fd, F_GETFL, 0);
     v &= ~O_NONBLOCK;
+#if defined(__APPLE__) && defined(__MACH__)
+    fcntl(_fd, F_SETFL | F_NOCACHE, v | O_SYNC);
+#else
     fcntl(_fd, F_SETFL, v | O_DIRECT | O_SYNC);
-
+#endif
     return _unbuffered_writes;
 }
 

libraries/AP_HAL_SITL/UART_utils.cpp

@@ -19,7 +19,7 @@
 
 #include "UARTDriver.h"
 
-#ifdef __CYGWIN__
+#if defined(__CYGWIN__) || defined(__APPLE__)
 #include <termios.h>
 #else
 #include <asm/termbits.h>
@@ -35,7 +35,7 @@ bool HALSITL::UARTDriver::set_speed(int speed)
     if (_fd < 0) {
         return false;
     }
-#ifdef __CYGWIN__
+#if defined(__CYGWIN__) || defined(__APPLE__)
     struct termios t;
     tcgetattr(_fd, &t);
     cfsetspeed(&t, speed);
@@ -68,7 +68,7 @@ void HALSITL::UARTDriver::configure_parity(uint8_t v)
     if (_fd < 0) {
         return;
     }
-#ifdef __CYGWIN__
+#if defined(__CYGWIN__) || defined(__APPLE__)
     struct termios t;
 
     tcgetattr(_fd, &t);
@@ -93,7 +93,7 @@ void HALSITL::UARTDriver::configure_parity(uint8_t v)
         t.c_cflag &= ~PARENB;
     }
 
-#ifdef __CYGWIN__
+#if defined(__CYGWIN__) || defined(__APPLE__)
     tcsetattr(_fd, TCSANOW, &t);
 #else
     ioctl(_fd, TCSETS2, &t);
@@ -105,7 +105,7 @@ void HALSITL::UARTDriver::set_stop_bits(int n)
     if (_fd < 0) {
         return;
     }
-#ifdef __CYGWIN__
+#if defined(__CYGWIN__) || defined(__APPLE__)
     struct termios t;
 
     tcgetattr(_fd, &t);
@@ -123,7 +123,7 @@ void HALSITL::UARTDriver::set_stop_bits(int n)
         t.c_cflag &= ~CSTOPB;
     }
 
-#ifdef __CYGWIN__
+#if defined(__CYGWIN__) || defined(__APPLE__)
     tcsetattr(_fd, TCSANOW, &t);
 #else
     ioctl(_fd, TCSETS2, &t);