Re: Success building seemingly native toolchain

[Richard Strand <richard dot strand at icomera dot com>]

Yann E. MORIN wrote:
> Hello Richard!
>
> Sorry for the long delay...
>   
No problem!

> On Tuesday 15 September 2009 18:58:24 Richard Strand wrote:
>   
> > I had a problem where crosstool-ng would break when it was building NPTL
> > when using glibc 2.7 and above. As I am using i686 to build i486 I
> > suspect this was the "seemingly native toolchains do not build" bug.
> >     
>
> Yes, you hit it.
>
>   
> > I have now managed to successfully get this to build by setting
> > CT_TARGET_CFLAGS="-O2".
> >     
>
> Ah! So far, CT_TARGET_CFLAGS is used only to build the C library (except
> uClibc) and gcc.
>
> glibc (and eglibc) are known to mis-compile (or refuse to compile at
> all) if -O is not specified in the CFLAGS. That's why it is currently
> hard-coded in the scripts. It is not said in the gcc manual if -O
> options are cumulative or if any -O option overrides any preceding
> option; in the build scripts, -O is specified after CT_TARGET_CFLAGS.
>
> I don't know about gcc, but building the final compiler is the only
> place that uses CT_TARGET_CFLAGS. I can't say how this is used by the
> gcc makefiles.
>
>   
> > Is this a known workaround for the problem (I couldn't find anything on
> > it), and does this work for everyone else?
> >     
>
> This is not a known workaround. But it might be as good as any thing
> else. Was your toolchain fully working? If so, then we might consider
> changing the -O into a -O2.
>   

The toolchain is working perfectly for me and I've not run into any 
problems yet. Changing to -O2 sounds like a good idea as long as it 
doesn't break builds for any other architectures.

Regards,

--Richard Strand


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