Re: perf build error with gcc 10 on arm and aarch64

[Leo Yan]

Hi Mike,

On Tue, May 05, 2020 at 11:26:49AM +0100, Mike Leach wrote:
> Hi Leo,
> 
> This is caused by GCC 10 new default to -fno-common. Temporarily
> adding this to perf build reproduces issue with other compilers,
> including x86 build of perf with cs-etm.

Good to know how to reproduce this issue.

> As such - your fix is good to resolve this issue.
> 
> Tested by / Reviewed by Mike Leach <mike.leach@xxxxxxxxxx>

Will send out patch to LKML soon.

Thank you for the testing and reviewing.

Thanks,
Leo

> On Tue, 5 May 2020 at 05:11, Leo Yan <leo.yan@xxxxxxxxxx> wrote:
> >
> > Hi Thomas,
> >
> > [ + Mathieu/Mike/Suzuki ]
> >
> > On Mon, May 04, 2020 at 10:22:27PM +0300, Thomas Backlund wrote:
> > > This is building perf from kernel-5.6.10 on armv7hl and aarch64:
> > >
> > > Compiler is gcc 10.1.0-RC
> > >
> > >
> > >   LD       perf-in.o
> > > ld: arch/perf-in.o: in function `.LANCHOR0':
> > > /home/iurt/rpmbuild/BUILD/kernel-arm/linux-5.6/tools/perf/util/include/../../util/cs-etm.h:118:
> > > multiple definition of `traceid_list'; util/perf-in.o:/home/iurt/rpmbuild/BUILD/kernel-arm/linux-5.6/tools/perf/util/cs-etm.h:118:
> > > first defined here
> > > make[3]: *** [/home/iurt/rpmbuild/BUILD/kernel-arm/linux-5.6/tools/build/Makefile.build:145:
> > > perf-in.o] Error 1
> > >
> > >   LD       perf-in.o
> > > ld: arch/perf-in.o:/home/iurt/rpmbuild/BUILD/kernel-aarch64/linux-5.6/tools/perf/util/include/../../util/cs-etm.h:118:
> > > multiple definition of `traceid_list'; util/perf-in.o:/home/iurt/rpmbuild/BUILD/kernel-aarch64/linux-5.6/tools/perf/util/cs-etm.h:118:
> > > first defined here
> > > make[3]: *** [/home/iurt/rpmbuild/BUILD/kernel-aarch64/linux-5.6/tools/build/Makefile.build:145:
> > > perf-in.o] Error 1
> > > make[2]: *** [Makefile.perf:616: perf-in.o] Error 2
> > > make[1]: *** [Makefile.perf:225: sub-make] Error 2
> > > make: *** [Makefile:70: all] Error 2
> > >
> > >
> > > The same build succeeds with gcc 9.3.0
> >
> > Thanks for reporting the issue.
> >
> > Could you help confirm if below change can resolve this issue?
> >
> > Thanks,
> > Leo
> >
> > ---8<---
> >
> > Subject: [PATCH] perf cs-etm: Move defined of traceid_list
> >
> > The variable 'traceid_list' is defined in the header file cs-etm.h,
> > if multiple C files include cs-etm.h the compiler might complaint for
> > multiple definition of 'traceid_list'.
> >
> > To fix multiple definition error, move the definition of 'traceid_list'
> > into cs-etm.c.
> >
> > Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> > ---
> >  tools/perf/util/cs-etm.c | 3 +++
> >  tools/perf/util/cs-etm.h | 3 ---
> >  2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> > index 62d2f9b9ce1b..381d9708e9bd 100644
> > --- a/tools/perf/util/cs-etm.c
> > +++ b/tools/perf/util/cs-etm.c
> > @@ -94,6 +94,9 @@ struct cs_etm_queue {
> >         struct cs_etm_traceid_queue **traceid_queues;
> >  };
> >
> > +/* RB tree for quick conversion between traceID and metadata pointers */
> > +static struct intlist *traceid_list;
> > +
> >  static int cs_etm__update_queues(struct cs_etm_auxtrace *etm);
> >  static int cs_etm__process_queues(struct cs_etm_auxtrace *etm);
> >  static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm,
> > diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h
> > index 650ecc2a6349..4ad925d6d799 100644
> > --- a/tools/perf/util/cs-etm.h
> > +++ b/tools/perf/util/cs-etm.h
> > @@ -114,9 +114,6 @@ enum cs_etm_isa {
> >         CS_ETM_ISA_T32,
> >  };
> >
> > -/* RB tree for quick conversion between traceID and metadata pointers */
> > -struct intlist *traceid_list;
> > -
> >  struct cs_etm_queue;
> >
> >  struct cs_etm_packet {
> > --
> > 2.17.1
> 
> 
> 
> -- 
> Mike Leach
> Principal Engineer, ARM Ltd.
> Manchester Design Centre. UK