PX4 SITL Matlab


Hello i have developed a flight controller with a fault injection method using simulink and the model was build successfully to be flashed to the Pixhawk but i need to do a SITL the model before i flash it to the hardware i tried to build the model on the posix shell but it gives me error i think related to the compiler so my question is
Is there is a way to change the compiler of the posix shell in the cmakefile and if not then is there is a way to test the simulink model before flashing it to the hardware?

Thanks in advance