function : only available as an intrinsic function
The specified function can only used in its intrinsic form. The directive to create a function call was ignored.
Your code used #pragma function to attempt to force the compiler to use the conventional function form of the specified function. However, the specified function is available only as an intrinsic.
Using #pragma function will not affect the specified function. You can avoid this warning by removing the #pragma function statement.
The following example causes this warning:
#include <malloc.h>
#pragma function(_alloca ) // warning: _alloca() is intrinsic only
void main(){}