# kbuild trick to avoid linker error. Can be omitted if a module is built.
  obj- := dummy.o
  
  # List of programs to build

  hostprogs-y := test_verifier test_maps

  hostprogs-y += sock_example

  hostprogs-y += fds_example

  hostprogs-y += sockex1

  hostprogs-y += sockex2

  hostprogs-y += sockex3

  hostprogs-y += tracex1

  hostprogs-y += tracex2

  hostprogs-y += tracex3

  hostprogs-y += tracex4

  hostprogs-y += tracex5

  hostprogs-y += tracex6

  hostprogs-y += test_probe_write_user

  hostprogs-y += trace_output

  hostprogs-y += lathist

  hostprogs-y += offwaketime

  hostprogs-y += spintest

  hostprogs-y += map_perf_test

  hostprogs-y += test_overhead

  hostprogs-y += test_cgrp2_array_pin

  hostprogs-y += xdp1

  hostprogs-y += xdp2

  hostprogs-y += test_current_task_under_cgroup

  hostprogs-y += trace_event

  hostprogs-y += sampleip

  hostprogs-y += tc_l2_redirect

  
  test_verifier-objs := test_verifier.o libbpf.o

  test_maps-objs := test_maps.o libbpf.o

  sock_example-objs := sock_example.o libbpf.o

  fds_example-objs := bpf_load.o libbpf.o fds_example.o

  sockex1-objs := bpf_load.o libbpf.o sockex1_user.o

  sockex2-objs := bpf_load.o libbpf.o sockex2_user.o

  sockex3-objs := bpf_load.o libbpf.o sockex3_user.o

  tracex1-objs := bpf_load.o libbpf.o tracex1_user.o

  tracex2-objs := bpf_load.o libbpf.o tracex2_user.o

  tracex3-objs := bpf_load.o libbpf.o tracex3_user.o

  tracex4-objs := bpf_load.o libbpf.o tracex4_user.o

  tracex5-objs := bpf_load.o libbpf.o tracex5_user.o

  tracex6-objs := bpf_load.o libbpf.o tracex6_user.o

  test_probe_write_user-objs := bpf_load.o libbpf.o test_probe_write_user_user.o

  trace_output-objs := bpf_load.o libbpf.o trace_output_user.o

  lathist-objs := bpf_load.o libbpf.o lathist_user.o

  offwaketime-objs := bpf_load.o libbpf.o offwaketime_user.o

  spintest-objs := bpf_load.o libbpf.o spintest_user.o

  map_perf_test-objs := bpf_load.o libbpf.o map_perf_test_user.o

  test_overhead-objs := bpf_load.o libbpf.o test_overhead_user.o

  test_cgrp2_array_pin-objs := libbpf.o test_cgrp2_array_pin.o

  xdp1-objs := bpf_load.o libbpf.o xdp1_user.o

  # reuse xdp1 source intentionally
  xdp2-objs := bpf_load.o libbpf.o xdp1_user.o

  test_current_task_under_cgroup-objs := bpf_load.o libbpf.o \
  				       test_current_task_under_cgroup_user.o

  trace_event-objs := bpf_load.o libbpf.o trace_event_user.o

  sampleip-objs := bpf_load.o libbpf.o sampleip_user.o

  tc_l2_redirect-objs := bpf_load.o libbpf.o tc_l2_redirect_user.o

  
  # Tell kbuild to always build the programs
  always := $(hostprogs-y)

  always += sockex1_kern.o

  always += sockex2_kern.o

  always += sockex3_kern.o

  always += tracex1_kern.o

  always += tracex2_kern.o

  always += tracex3_kern.o

  always += tracex4_kern.o

  always += tracex5_kern.o

  always += tracex6_kern.o

  always += test_probe_write_user_kern.o

  always += trace_output_kern.o

  always += tcbpf1_kern.o

  always += tcbpf2_kern.o

  always += tc_l2_redirect_kern.o

  always += lathist_kern.o

  always += offwaketime_kern.o

  always += spintest_kern.o

  always += map_perf_test_kern.o

  always += test_overhead_tp_kern.o
  always += test_overhead_kprobe_kern.o

  always += parse_varlen.o parse_simple.o parse_ldabs.o

  always += test_cgrp2_tc_kern.o

  always += xdp1_kern.o

  always += xdp2_kern.o

  always += test_current_task_under_cgroup_kern.o

  always += trace_event_kern.o

  always += sampleip_kern.o

  
  HOSTCFLAGS += -I$(objtree)/usr/include

  
  HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable

  HOSTLOADLIBES_fds_example += -lelf

  HOSTLOADLIBES_sockex1 += -lelf

  HOSTLOADLIBES_sockex2 += -lelf

  HOSTLOADLIBES_sockex3 += -lelf

  HOSTLOADLIBES_tracex1 += -lelf

  HOSTLOADLIBES_tracex2 += -lelf

  HOSTLOADLIBES_tracex3 += -lelf

  HOSTLOADLIBES_tracex4 += -lelf -lrt

  HOSTLOADLIBES_tracex5 += -lelf

  HOSTLOADLIBES_tracex6 += -lelf

  HOSTLOADLIBES_test_probe_write_user += -lelf

  HOSTLOADLIBES_trace_output += -lelf -lrt

  HOSTLOADLIBES_lathist += -lelf

  HOSTLOADLIBES_offwaketime += -lelf

  HOSTLOADLIBES_spintest += -lelf

  HOSTLOADLIBES_map_perf_test += -lelf -lrt

  HOSTLOADLIBES_test_overhead += -lelf -lrt

  HOSTLOADLIBES_xdp1 += -lelf

  HOSTLOADLIBES_xdp2 += -lelf

  HOSTLOADLIBES_test_current_task_under_cgroup += -lelf

  HOSTLOADLIBES_trace_event += -lelf

  HOSTLOADLIBES_sampleip += -lelf

  HOSTLOADLIBES_tc_l2_redirect += -l elf

  # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
  #  make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang

  LLC ?= llc

  CLANG ?= clang

  # Trick to allow make to be run from this directory
  all:
  	$(MAKE) -C ../../ $$PWD/
  
  clean:
  	$(MAKE) -C ../../ M=$$PWD clean
  	@rm -f *~

  # Verify LLVM compiler tools are available and bpf target is supported by llc
  .PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)

  verify_cmds: $(CLANG) $(LLC)
  	@for TOOL in $^ ; do \
  		if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
  			echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
  			exit 1; \
  		else true; fi; \
  	done

  verify_target_bpf: verify_cmds

  	@if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
  		echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
  		echo "   NOTICE: LLVM version >= 3.7.1 required" ;\
  		exit 2; \
  	else true; fi
  
  $(src)/*.c: verify_target_bpf

  # asm/sysreg.h - inline assembly used by it is incompatible with llvm.
  # But, there is no easy way to fix it, so just exclude it since it is

  # useless for BPF samples.

  $(obj)/%.o: $(src)/%.c

  	$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \

  		-D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \

  		-Wno-compare-distinct-pointer-types \

  		-O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@