14.10.6 iocheck

The iocheck keyword is used to declare a routine which causes generation of I/O result checking code within a {$IOCHECKS ON} block whenever it is called.

The result is that if a call to this procedure is generated, the compiler will insert I/O checking code if the call is within a {$IOCHECKS ON} block.

This modifier is intended for RTL internal routines, not for use in application code.