bpf compile

clang -nostdinc
-isystem /usr/lib/gcc/x86_64-linux-gnu/9/include
-I/usr/src/linux-headers-5.4.0-91-generic/arch/x86/include
-I/usr/src/linux-headers-5.4.0-91-generic/arch/x86/include/uapi
-I/usr/src/linux-headers-5.4.0-91-generic/arch/x86/include/generated
-I/usr/src/linux-headers-5.4.0-91-generic/arch/x86/include/generated/uapi
-I/usr/src/linux-headers-5.4.0-91-generic/include
-I/usr/src/linux-headers-5.4.0-91-generic/include/uapi
-I/usr/src/linux-source-5.4.0/tools/testing/selftests/bpf
-include /usr/src/linux-headers-5.4.0-91/include/linux/kconfig.h
-D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign -D__TARGET_ARCH_x86 -Wno-compare-distinct-pointer-types -Wno-gnu-variable-sized-type-not-at-end -Wno-address-of-packed-member -Wno-tautological-compare -Wno-unknown-warning-option -include asm_goto_workaround.h
-O2 -emit-llvm -c tc_l2_redirect_kern.c -o -| llc -march=bpf -mcpu=probe -filetype=obj -o tc_l2_redirect_kern.o