Re: [Qemu-devel] [RFC PATCH] Allow building without graphics support

[Scott Wood]

On 12/13/2012 12:58:19 PM, Stefan Weil wrote:
> Am 13.12.2012 16:53, schrieb Scott Wood:
> > On 12/13/2012 12:31:14 AM, Stefan Weil wrote:
> > > Indeed, --cross-prefixdoes not support absolute path names.
> > >
> > > I assume that the executables in
> > > /home/scott/fsl/tc/gcc-4.5.55-eglibc-2.11.55/powerpc-linux-gnu/binare  
> > > without prefix
> > > (gcc, ld, ...).
> >
> > No, they are with prefix, just not in $PATH.  I have more than one  
> > "powerpc-linux-gnu" toolchain and I don't want to mess with my $PATH  
> > constantly to choose between them.
> >
> > > Then there must also be the same executables with prefix
> > > (powerpc-linux-gnu-gcc, powerpc-linux-gnu-ld, ...). These must be  
> > > somewhere in PATH.
> >
> > No.  This was never a requirement before -- why now?
> >
> > > Use --cross-prefix=powerpc-linux-gnu-(note the "-" at the end).
> > > Then pixman would be configured with --host=powerpc-linux-gnu and  
> > > should find
> > > the compiler. It won't find the compiler powerpc-linux-gcc when its  
> > > real name is
> > > powerpc-linux-gnu-gcc.
> >
> > No, it's real name is  
> > /home/scott/fsl/tc/gcc-4.5.55-eglibc-2.11.55/powerpc-linux-gnu/bin/powerpc-linux-gnu-gcc
> >
> > -Scott
>
>
> That are a lot of "no"s. So let me try to be a bit clearer.
>
> You said that you forced --host=powerpc-linux into the pixman  
> configure command.
> That cannot work, because your host prefix is powerpc-linux-gnu, not  
> powerpc-linux.
> No wonder that pixman used the native compiler.

It wouldn't have mattered.  There is no powerpc-linux-gnu-gcc in the  
path either.

> A cross prefix which starts with an absolute path (like in your  
> scenario) justs
> requires adding `dirname "${cross_prefix}"` to PATH and passing
> `basename "${cross_prefix%-}" to the pixman configure.

Right...  I'm not thrilled at the idea of build scripts messing with  
$PATH -- normally I deal with autoconf builds by explicitly passing in  
CC and such (and am much happier when I encounter a project such as  
QEMU-until-recently that is fine with just a cross prefix rather than a  
host tuple) -- but the alternative is making the QEMU build scripts  
aware of every build tool than pixman requires.

What I don't want to do is put it in $PATH semi-permanently, in the  
interactive instance of the shell.

> These modifications could be added to QEMU's configure and Makefile
> if we really want that. Installing pixman once manually also works
> and saves compilation time for repeated builds. That's why I no longer
> use internal pixman for any of my cross compilations.

Yes, I could manually install it, though then I get to deal with  
telling the pixman build exactly where to install itself, and repeating  
the process for each toolchain and multilib-variant thereof.

-Scott