On Fri, Jan 16, 2015 at 03:15:52PM +0100, Jiri Olsa wrote: > 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 ;-)
ok, for a minute I forgot I'm stealing this from kbuild.. aaand they have a solution of course ;-) so I'm now always creating $(obj)-in.o objects (even empty ones), and it seems to work nicely.. as in kbuild ;-) the update 'perf/build' branch' with the fix is in: git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git perf/build I tried on arm64,ppc64,s390,x86_64,i386 I'll spin v3 shortly (after doc updates), but any testing would be great thanks, jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
