port-i386/45374: -current tools using machine-local CPU CFLAGS overriding mk.conf

[Matthew Mondor <mm_lists%pulsar-zone.net@localhost>]

>Number:         45374
>Category:       port-i386
>Synopsis:       -current tools using machine-local CPU CFLAGS overriding 
>mk.conf
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Sep 18 07:50:00 +0000 2011
>Originator:     Matthew Mondor
>Release:        -current
>Organization:
>Environment:
Architecture: i386
Machine: i386
>Description:

I'm not really sure why GMP is now needed as part of /usr/tools, but I
noticed that while other tools will by default ignore mk.conf
CFLAGS/CCOPTS and ensure to use x86 agnostic CFLAGS (so that they're
portable among x86 systems), GMP will use its own heuristics and build
using CFLAGS optimized for the current machine.

While this could potentially increase the speed of system builds, it is
new behaviour, and /usr/tools can no longer be shared among x86
variants of a network.  I tried setting conservative CFLAGS
via /etc/mk.conf but those also are ignored by GMP.

>How-To-Repeat:

Build /usr/tools using build.sh on a build host; attempt to use them
from other x86 variants across a network.  I.e. a mix of 32-bit-mode
core2, p4 and other i686.

>Fix:

Currently unknown; tell GMP at configuration to not do heuristics,
or give it conservative x86 CFLAGS to use?  Or observe mk.conf provided
CFLAGS instead of ignoring them when building tools?  So that
CFLAGS+='-march=i686 -O2' would work for /usr/tools/ ...

Thanks,