On Sun, Oct 13, 2019 at 06:42:20PM -0700, Alexei Starovoitov wrote: > On Fri, Oct 11, 2019 at 1:01 PM Nathan Chancellor > <natechancellor@xxxxxxxxx> wrote: > > > > On Thu, Oct 03, 2019 at 10:48:31PM +0800, kbuild test robot wrote: > > > CC: kbuild-all@xxxxxx > > > TO: Alexei Starovoitov <ast@xxxxxxxxxx> > > > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git btf_vmlinux > > > head: cc9b0a180111f856b93a805fdfc2fb288c41fab2 > > > commit: 82b70116b6ba453e1dda06c7126e100d594b8e0a [1/7] bpf: add typecast to help vmlinux BTF generation > > > config: x86_64-rhel-7.6 (attached as .config) > > > compiler: clang version 10.0.0 (git://gitmirror/llvm_project 38ac6bdb83a9bb76c109901960c20d1714339891) > > > reproduce: > > > git checkout 82b70116b6ba453e1dda06c7126e100d594b8e0a > > > # save the attached .config to linux build tree > > > make ARCH=x86_64 > > > > > > If you fix the issue, kindly add following tag > > > Reported-by: kbuild test robot <lkp@xxxxxxxxx> > > > > > > All warnings (new ones prefixed by >>): > > > > > > In file included from net/mac80211/trace.c:11: > > > In file included from net/mac80211/./trace.h:2717: > > > In file included from include/trace/define_trace.h:104: > > > In file included from include/trace/bpf_probe.h:110: > > > >> net/mac80211/./trace.h:253:1: warning: redefinition of typedef 'btf_trace_local_only_evt' is a C11 feature [-Wtypedef-redefinition] > > > DEFINE_EVENT(local_only_evt, drv_start, > > > ^ > > > include/trace/bpf_probe.h:104:2: note: expanded from macro 'DEFINE_EVENT' > > > __DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args), 0) > > > ^ > > > include/trace/bpf_probe.h:77:16: note: expanded from macro '__DEFINE_EVENT' > > > typedef void (*btf_trace_##template)(void *__data, proto); \ > > > > Hi Alexei, > > > > The 0day team has been running clang builds for us for a little bit and > > this one popped up. It looks like there are certain tracepoints that use > > the same template so clang warns because there are two identical > > typedefs. Is there any way to improve this so we don't get noisey > > builds? This still occurs as of your latest btf_vmlinux branch even > > though this report is from a week ago. > > Thanks for headsup. That was indeed a valid bug in my branch. > Interestingly gcc didn't complain. > I knew that 0day bot is testing my development tree, but > I didn't know it's doing it with clang. > And for some reason I didn't receive any reports > about this breakage. > More so I got 'build success' email from 0day for my branch. > Something to improve in the bot, I guess. > > If you're curious the fix was: > -typedef void (*btf_trace_##template)(void *__data, proto); \ > +typedef void (*btf_trace_##call)(void *__data, proto); \ > > I forced pushed my btf_vmlinux branch. > Please let me know if you still see this issue. > > Thanks! Yes, right now, the 0day build reports for clang are only getting sent to our mailing list (clang-built-linux@xxxxxxxxxxxxxxxx) because there is a lot of overlap with GCC. We have been manually triaging the build warnings and forwarding them along. I think the 0day maintainers eventually intend to make these emails more public (maybe have an opt in system when maintainers want to see clang build results, with the understanding there might be duplicates?). Unfortunately, I cannot speak for them. I brought down your branch and built the net/ subdirectory with the config that produced this warning and I do not see any warnings. Thanks for the quick response! Nathan
