Support cross-testing (version 3)

[Joseph S. Myers]

On Fri, 2 Nov 2012, Andreas Schwab wrote:

> "Joseph S. Myers" <joseph@codesourcery.com> writes:
> 
> > +# Remove unnecessary newlines from a Bourne shell command sequence.
> > +remove_newlines ()
> > +{
> > +  sed -n \
> > +    -e '1h' \
> > +    -e '2,$H' \
> > +    -e '${g
> > +          s/\([^\]\)\n/\1; /g
> > +          p
> > +         }'
> > +}
> 
> That doesn't work with embedded newlines.

As I just said, I'd be happy for it to be removed.  Fortunately nothing is 
relying on environment variables with newlines being passed through this 
way, and as I've also said I think we should aim for not needing this 
environment variable passthrough by getting everywhere relying on 
environment variables set in makefiles, at top of scripts etc. being 
applicable on the host to pass them explicitly via test-wrapper-env - but 
that cleanup may be a longer-term goal (it requires checking a lot of code 
that might set environment variables and working out where their values 
are needed).

I'm not sure what "The 'export -p' command adds backslashes for 
environment variables which contain newlines." was originally referring to 
- maybe some way in which the output of older versions of bash differed 
from what bash now does.  (This optimization originated in 
<http://www.eglibc.org/archives/patches/msg00318.html> in 2007.)

-- 
Joseph S. Myers
joseph@codesourcery.com