Require binutils 2.20 or later to build glibc

[Ryan S. Arnold]

On Mon, Feb 27, 2012 at 2:46 PM, Joseph S. Myers
<joseph@codesourcery.com> wrote:
> On Mon, 27 Feb 2012, Ryan Arnold wrote:
>
>> I have a concern with making 4.3 the minimum compiler.  There are still
>> current and previous versions of GNU/Linux Distributions that have
>> earlier-than-4.3 compilers.
>>
>> I maintain a toolchain that is built on n-1 distributions to work there
>> and at level n.  Making 4.3 the minimum compiler complicates the initial
>> bootstrap process (by introducing several extra stages).
>
> A toolchain including glibc?
>
> Normally a native toolchain would not include glibc - it would work with
> the system's pre-existing glibc, since using a different glibc from that
> installed in /lib etc. isn't particularly convenient - while a cross
> toolchain would include the compiler used to build glibc and the
> distribution's native compiler version wouldn't be relevant.  (To be
> clear, the version requirement proposal is purely about $CC, the compiler
> used to build glibc itself, not $BUILD_CC, the native compiler for the
> system on which glibc is built.)

Yes, it's used to make early use of compiler and library performance
and functionality improvements.  I just reviewed our scripting and
verified that we don't actually build GLIBC in any stage with the
system compiler, so we should be ok.

Ryan