How to get the multi-lib options of a RTEMS installation

[Ralf Corsepius]

On 02/09/2012 05:44 PM, Sebastian Huber wrote:
> Hello,
>
> the RTEMS tool chain ships with so called multi-libs, e.g.
>
> find /opt/rtems-4.11/powerpc-rtems4.11/ -name libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/nof/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m7400/nof/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m7400/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m604/nof/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m604/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m403/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m505/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m860/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m8540/nof/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m8540/floatgprssingle/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m8540/floatgprsdouble/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m8540/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m8540/gprsdouble/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m603e/nof/libc.a
> /opt/rtems-4.11/powerpc-rtems4.11/lib/m603e/libc.a
>
> Is there a why to get the GCC options which were used to generate these
> multi-libs?
No. That's not how multilibs work.

The multilib directories are gcc internal default library search-paths, 
GCC switches to when it finds certain combinations of flags in the 
CFLAGS/LDFLAGS being passed to it.

I.e. there is a "multilib options" -> "multilibdir" transformation,
but there is no reverse transformation.

> This whould be nice for building libraries which depend only
> on POSIX interfaces.
I don't understand this question. Are you trying to build an RTEMS with 
cpukit/posix enabled (or more general, with RTEMS cpukit specific flags 
enabled) for some multilib variants and disabled for others and are 
trying to install them into the default directories? In general, this 
doesn't work.


Ralf