<varargs.h> and the PERQ

Robert Stroud robert at cheviot.UUCP
Wed Dec 19 00:19:37 AEST 1984


<This line is a figment of your imagination>

According to Henry Spencer @ U of Toronto Zoology

> ...     there are some misguided "high-level-language" machines --
> the PERQ is an example -- which ...
> ... *insist* on knowing how big the arglist is
> for a given function, have it figuring in the calling sequence to the
> point where you can't lie without disaster, and insist that the number
> be a constant for each function.

> There exist machines on which <varargs.h> is unimplementable.

> The PERQ, on which the parameter list of a function must have a constant
> length, the same length for all calls.

My PERQ has been microcoded as a C machine (rather than a Pascal machine)
and runs a version of Unix called PNX = Version 7 + Window Manager + some
System III utilities and system calls.

<varargs.h> is supplied and seems to work perfectly. The CALLING function
pushes the arguments onto the stack; the CALLED function just grabs them
and doesn't care how many there are.

Sounds to me like whoever tried to implement C and Unix on top of an
inappropriate (microcoded) architecture was misguided (:-)

Robert J Stroud,
University of Newcastle upon Tyne.

..!ukc!cheviot!robert



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