This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: Stub sys/io.h?
- From: Roland McGrath <roland at hack dot frob dot com>
- To: "Carlos O'Donell" <carlos at redhat dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>
- Date: Tue, 15 Jul 2014 11:27:29 -0700 (PDT)
- Subject: Re: Stub sys/io.h?
- Authentication-results: sourceware.org; auth=none
- References: <53C40B1D dot 7000002 at redhat dot com>
I think the historical rationale was that <sys/io.h> was an x86-specific
API for something that didn't even have an analogue on other machines. So
it was part of the Linux/x86-specific and Hurd/x86-specific APIs that does
not exist at all for other configurations, rather than being part of the
generic glibc API that gets stubs in a configuration that doesn't (or
can't) implement something meaningful.
The traditional interfaces (in*, out*) are ones that are more like
intrinsics for special machine instructions (which is all they are on x86).
They're not OS interfaces that have a mechanism to report failure. So this
API seems like a really poor fit for the notion of having a generic API
that could have a stub implementation.