[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [Bug 929638] Re: qemu 1.0 unable to compile on the pand
From: |
Paul Brook |
Subject: |
Re: [Qemu-devel] [Bug 929638] Re: qemu 1.0 unable to compile on the pandaboard ES |
Date: |
Thu, 9 Feb 2012 23:55:26 +0000 |
User-agent: |
KMail/1.13.7 (Linux/3.1.0-1-amd64; KDE/4.6.5; x86_64; ; ) |
> > I'd rather not. If at all possible we should avoid runtime tests. Even
> > for "native" systems they generally give the wrong answer as the machine
> > you're building on often isn't the one you will be running on. If we
> > know arm hosts are broken then that's what we should test for in
> > configure (with a comment saying why).
> >
> > IMO consistency between builds for the same target environment is more
> > important than opportunistically probing in a native builds.
>
> I agree for CPU features, sure. Anything that would be influenced by your
> build system vs execution environment. But in this case we're probing for
> a feature of a library we're linking against, so runtime checks really
> aren't all that bad, since you usually want to build against the same libc
> that you're executing against later on.
Maybe, but I don't consider "assume it's broken when cross compiling" to be an
acceptable answer. If we can't get the same answer in a cross environment
then I don't want to be doing it at all.
Using a native build environment is often infeasible. The Debian/Ubuntu and
Maemo folks do crazy things to make it happen, but often as not you're cross
building the whole system from scratch.
Even in a desktop context, all my production builds are done with a cross
compiler[1]. Having that cross build behave differently from a native build
using the exact same libraries and config is liable to cause the absolute
worst kind of bugs - the sort that only shows up in something you're about
to/already have shipped to the customer.
Paul
[1] The build cluster runs modern 64-bit linux, but the end result needs to
work on older 32-bit linux and windows. There's no way I'm setting up a
cluster of RHEL4 and windows XP machines to do native builds, but I can easily
maintain a cross toolchain to win32 or RHEL4 i686 sysroot indefinitely.
[Prev in Thread] |
Current Thread |
[Next in Thread] |