Re: [PATCH] rename COMPAT_FREEBSD32

> On Mar 22, 2010, at 10:52 AM, David O'Brien wrote:
>
>>/ On Mon, Mar 15, 2010 at 09:00:18AM -0700, Julian Elischer wrote:
/>>>/ I certainly agree.. can it be changed please?
/>>/ 
/>>/ I've waited a while to see what other opinions would be expressed on this
/>>/ topic.  I believe there is sufficient support to rename COMPAT_FREEBSD32
/>>/ to something else based on responses in the mailing lists.
/>>/ 
/>>/ I am sorry if some may wish to label this a "bikeshead".  But we seem to
/>>/ have many folks disliking "COMPAT_FREEBSD32".
/>>/ 
/>>/ 
/>>/ Based on responses to the topic of COMPAT_FREEBSD32, the following
/>>/ were the suggestions offered:
/>>/    COMPAT_ARCH32, COMPAT_ARCH_32BIT, COMPAT_32BIT_ARCH, COMPAT_32BIT,
/>>/    COMPAT_FREEBSD32BIT
/>
> There's probably a bigger problem than just how we name it. The option
> really encodes 2 independent aspects:
> 1.  Support for a 32-bit ABI (i.e. ILP32)
> 2.  Support for a particular OS in ILP32.
>
> Of course 2 implies 1.
>
> For example:
> COMPAT_IA32 in sys/ia64/ia64/machdep.c enabled code to save and restore
> IA32 registers as part of cpu_switch(). In this context COMPAT_IA32 was
> perfectly named. It's now called COMPAT_FREEBSD32, which doesn't make a
> lot of sense because what if I only want to support Linux/ia32 and not
> FreeBSD/ia32 (or vice-versa if you club them under a single COMPAT_*32)?

The original version of my my patch had this split, with a COMPAT_FREEBSD32
and a COMPAT_[IA/PPC/MIPS]32. The problem is that the 32-bit FreeBSD compat is
deeply intertwined with providing support for any 32-bit binaries at all (e.g.,
the 32-bit linuxolator depends on calling into it), so it isn't actually possible
to support having COMPAT_LINUX32 without COMPAT_FREEBSD32 without a huge amount
of work. So I scrapped that in favor of the unified name only, and we
ended up with COMPAT_FREEBSD32.

In any event, given the persistent interest and consolidation around
COMPAT_ARCH32, I'm fine changing the name.
-Nathan