Re: [PATCHv2 00/36] perf tools: New build framework

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Jan 16, 2015 at 01:49:10PM +0000, Mark Rutland wrote:
> Hi,
> 
> [...]
> 
> > > > > I just tried a cross-build for arm, and that blew up when trying to do
> > > > > something with arch/arm/util/libperf-in.o (log below). I bisected that
> > > > > to f169fbc4c59dd9d4 "perf build: Add arch x86 objects building". I'm
> > > > > looking into why now.
> > > > 
> > > > I get a similar failure doing a native arm64 build. I think the problem is
> > > > because the arch/ files for arm and arm64 aren't always required (i.e. there
> > > > are configurations where nothing is built under there) and, consequently,
> > > > libperf-in.o isn't actually needed and we try to link against something that
> > > > doesn't exist.
> > > 
> > > exactly ;-) I'll spin v3 shortly..
> > 
> > this fixes the issue for me
> > 
> > jirka
> > 
> > 
> > ---
> > diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build
> > index d35b66014992..396b33b124d1 100644
> > --- a/tools/build/Makefile.build
> > +++ b/tools/build/Makefile.build
> > @@ -52,7 +52,7 @@ quiet_cmd_cc_s_c = AS       $@
> >  
> >  # Link agregate command
> >  quiet_cmd_ld_multi = LD       $@
> > -      cmd_ld_multi = $(LD) -r -o $@ $^
> > +      cmd_ld_multi = $(LD) -r -o $@ $(wildcard $^)
> >  
> >  # Build rules
> >  $(OUTPUT)%.o: %.c FORCE
> > 
> 
> Unfortunately that doesn't seem to be sufficient for me when
> cross-compiling. It looks like it supresses the warning from Make, but
> then LD explodes anyway because it wasn't provided any input files (log
> below).

argh.. right, when there are no source objects at all :-\ fix is comming ;-)

thanks,
jirka