sys/_types.h: define __(u)int(f)ptr_t for CHERI

[brooks]

Summary

On pure-capability ABIs, uintptr_t and variants are capabilities and
defined to the new primative type __uintcap_t and variants. This is
required to allow pointers (capabilities) to round trip through
uintptr_t as required by the C standard.

Effort: CHERI upstreaming
Sponsored by: Innovate UK

[kib]

And where is __intcap_t defined? Is it provided by some MD include, like machine/_types.h?

I do not remember seeing this MD define in the review series. If true, then should __intcap_t added before the use?

[brooks]

In D53819#1229955, @kib wrote:

And where is __intcap_t defined? Is it provided by some MD include, like machine/_types.h?

I do not remember seeing this MD define in the review series. If true, then should __intcap_t added before the use?

__intcap_t is a new primitive type provided by the compiler. It cannot be defined by a header except on systems that don't support it.

[jrtc27]

In D53819#1229986, @brooks wrote:

In D53819#1229955, @kib wrote:

And where is __intcap_t defined? Is it provided by some MD include, like machine/_types.h?

I do not remember seeing this MD define in the review series. If true, then should __intcap_t added before the use?

__intcap_t is a new primitive type provided by the compiler. It cannot be defined by a header except on systems that don't support it.

Eh, not quite. ((un)signed) __intcap is the primitive but there are also __(u)intcap_t pre-defined by the compiler. A bit weird to provide both but that's how int128 works; you get both ((un)signed) __int128 and __(u)int128_t out of the box.