Interaction between storage class and qualifiers

[Henry Spencer]

In article <2760 at charon.cwi.nl> jack at cwi.nl (Jack Jansen) writes:
>The SGI C compiler treats the following two pointers as unequal:
>	register volatile struct foo *p1;
>	volatile register struct foo *p2;
>p1 is a pointer (in a register) to a volatile struct foo, while
>p2 is a volatile pointer (in a register) to a struct foo.

This is incorrect.  The standard attributes no significance to the order
of storage class specifiers, type specifiers, and type qualifiers in the
declaration-specifiers list beginning a declaration.  The type specifiers
(in this case `struct foo') and type qualifiers (`volatile') all go to
forming the "base type", so to speak, for the declaration.

The way to declare a volatile pointer (in a register) to a struct foo is

	register struct foo * volatile p3;

See the pointer-declarator rules in 3.5.4.1.

>... I haven't been able to find anything in
>the standard about the interaction of storage classes and type
>qualifiers.

That's because there is none.  The storage class is completely independent
of the type.
-- 
If the Space Shuttle was the answer,   | Henry Spencer at U of Toronto Zoology
what was the question?                 |  henry at zoo.toronto.edu   utzoo!henry