Em Thu, Jun 14, 2018 at 02:47:59PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Thu, Jun 14, 2018 at 10:21:30AM -0700, Alexei Starovoitov escreveu: > > On 6/14/18 10:18 AM, Arnaldo Carvalho de Melo wrote: > > > Just out of curiosity, is there any plan to have this as a clang option? > > I think > > clang ... -mllvm -mattr=dwarfris > > should work. > The message "(LLVM option parsing)" implies what you suggest, but didn't > worked :-\ > -mllvm <value> Additional arguments to forward to LLVM's option > processing > Almost there tho :-\
So I thought that this -mattr=dwarfris would be available only after I set the target, because I tried 'llc -mattr=help' and dwarfris wasn't there: [acme@jouet perf]$ llc -mattr=help |& grep dwarf [acme@jouet perf]$ Only after I set the arch it appears: [acme@jouet perf]$ llc -march=bpf -mattr=help |& grep dwarf dwarfris - Disable MCAsmInfo DwarfUsesRelocationsAcrossSections. dwarfris - Disable MCAsmInfo DwarfUsesRelocationsAcrossSections. dwarfris - Disable MCAsmInfo DwarfUsesRelocationsAcrossSections. [acme@jouet perf]$ But even after moving the '-mllvm -mattr=dwarfris' to after '-target bpf' it still can't grok it :-\ /usr/local/bin/clang -D__KERNEL__ -D__NR_CPUS__=4 -DLINUX_VERSION_CODE=0x41100 -g -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h -I/home/acme/lib/include/perf/bpf -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/4.17.0-rc5/build -c /home/acme/bpf/hello.c -target bpf -mllvm -mattr=dwarfris -O2 -o hello.o So onlye with 'clang ... -target bpf -emit-llvm -O2 -o - | llc -march=bpf -mattr=dwarfris ...' things work as we expect. - Arnaldo
