HP C/iX Reference Manual (31506-90011)

Chapter 10 177

Using Intrinsics

Intrinsic Pragma

• Inserts "hidden" arguments required to correctly call Pascal routines that have

ANYVAR parameters (size is hidden) or that are EXTENSIBLE (parameter count is

hidden).

If you declare a system intrinsic using an extern declaration rather than an intrinsic

program, and if you do not provide a function prototype, none of the above checks,

conversions, or insertions are done. The address of an intrinsic can be taken, but if a call is

made using a pointer to the intrinsic, the above checks are not performed. The intrinsic

call then degenerates into a normal C function call.

To ensure that all calls are handled correctly by the compiler, the intrinsic pragma should

declare the name of the intrinsic using an identiﬁer with the identical case that is used by

the function calls in the program, especially if the optional user-name is not speciﬁed. No

other functions in the program should have the same name as any intrinsic that is

declared, regardless of the case. This is because the actual run time symbol used to call an

intrinsic is not necessarily the same case as the identiﬁer used to declare that intrinsic.

There are a few HP C library routines, such as fopen or fwrite, that have the same names

as intrinsic functions. If you wish to call any of these C library routines that always use

lower case identiﬁers from a program that also calls the intrinsics with the same name, the

intrinsics must be declared and called using mixed case or upper case identiﬁers, or by

using the optional user-name.