Re: [Qemu-devel] [PATCH RFC] Makefile.target: prepend $libs_softmmu to $LIBS

[Wei Liu]

On Tue, Mar 10, 2015 at 11:16:40AM +0100, Paolo Bonzini wrote:
> 
> 
> On 09/03/2015 15:54, Wei Liu wrote:
> > I discovered a problem when trying to build QEMU statically with gcc.
> > libm is an element of LIBS while libpixman-1 is an element in
> > libs_softmmu. Libpixman references functions in libm, so the original
> > ordering makes linking fail.
> > 
> > This fix is to reorder $libs_softmmu and $LIBS to make -lm appear after
> > -lpixman-1. However I'm not quite sure if this is the right fix, hence
> > the RFC tag.
> > 
> > Normally QEMU is built with c++ compiler which happens to link in libm
> > (at least this is the case with g++), so building QEMU statically
> > normally just works and nobody notices this issue.
> > 
> > Signed-off-by: Wei Liu <address@hidden>
> > ---
> >  Makefile.target | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/Makefile.target b/Makefile.target
> > index 2262d89..1083377 100644
> > --- a/Makefile.target
> > +++ b/Makefile.target
> > @@ -134,7 +134,7 @@ obj-$(CONFIG_KVM) += kvm-all.o
> >  obj-y += memory.o savevm.o cputlb.o
> >  obj-y += memory_mapping.o
> >  obj-y += dump.o
> > -LIBS+=$(libs_softmmu)
> > +LIBS := $(libs_softmmu) $(LIBS)
> 
> A side effect of the patch is that changes to libs_softmmu do not
> propagate into LIBS.  So you also need this:
> 
> diff --git a/hw/display/Makefile.objs b/hw/display/Makefile.objs
> index 7ed76a9..4eb9e98 100644
> --- a/hw/display/Makefile.objs
> +++ b/hw/display/Makefile.objs
> @@ -20,7 +20,7 @@ common-obj-$(CONFIG_ZAURUS) += tc6393xb.o
>  
>  ifeq ($(CONFIG_MILKYMIST_TMU2),y)
>  common-obj-y += milkymist-tmu2.o
> -libs_softmmu += $(GLX_LIBS)
> +milkymist-tmu2.o-libs += $(GLX_LIBS)
>  endif
>  
>  obj-$(CONFIG_OMAP) += omap_dss.o
> 
> 
> Because there are pending changes to OpenGL detection, I'll keep
> this patch queued in my tree and will probably submit it only for
> 2.4.

I don't quite follow. Do you want me to carry your patch in my own tree,
wait for you to submit your patch (and get merged), then I submit my
patch again?

Wei.

> 
> Paolo