linux/tools/bpf/runqslower/Makefile
Andrii Nakryiko dfc55ace99 tools/runqslower: Ensure own vmlinux.h is picked up first
Reorder include paths to ensure that runqslower sources are picking up
vmlinux.h, generated by runqslower's own Makefile. When runqslower is built
from selftests/bpf, due to current -I$(BPF_INCLUDE) -I$(OUTPUT) ordering, it
might pick up not-yet-complete vmlinux.h, generated by selftests Makefile,
which could lead to compilation errors like [0]. So ensure that -I$(OUTPUT)
goes first and rely on runqslower's Makefile own dependency chain to ensure
vmlinux.h is properly completed before source code relying on it is compiled.

  [0] https://travis-ci.org/github/libbpf/libbpf/jobs/677905925

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200422012407.176303-1-andriin@fb.com
2020-04-24 17:45:20 -07:00

85 lines
2.3 KiB
Makefile

# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
OUTPUT := .output
CLANG ?= clang
LLC ?= llc
LLVM_STRIP ?= llvm-strip
DEFAULT_BPFTOOL := $(OUTPUT)/sbin/bpftool
BPFTOOL ?= $(DEFAULT_BPFTOOL)
LIBBPF_SRC := $(abspath ../../lib/bpf)
BPFOBJ := $(OUTPUT)/libbpf.a
BPF_INCLUDE := $(OUTPUT)
INCLUDES := -I$(OUTPUT) -I$(BPF_INCLUDE) -I$(abspath ../../lib)
CFLAGS := -g -Wall
# Try to detect best kernel BTF source
KERNEL_REL := $(shell uname -r)
VMLINUX_BTF_PATHS := /sys/kernel/btf/vmlinux /boot/vmlinux-$(KERNEL_REL)
VMLINUX_BTF_PATH := $(or $(VMLINUX_BTF),$(firstword \
$(wildcard $(VMLINUX_BTF_PATHS))))
abs_out := $(abspath $(OUTPUT))
ifeq ($(V),1)
Q =
msg =
else
Q = @
msg = @printf ' %-8s %s%s\n' "$(1)" "$(notdir $(2))" "$(if $(3), $(3))";
MAKEFLAGS += --no-print-directory
submake_extras := feature_display=0
endif
.DELETE_ON_ERROR:
.PHONY: all clean runqslower
all: runqslower
runqslower: $(OUTPUT)/runqslower
clean:
$(call msg,CLEAN)
$(Q)rm -rf $(OUTPUT) runqslower
$(OUTPUT)/runqslower: $(OUTPUT)/runqslower.o $(BPFOBJ)
$(call msg,BINARY,$@)
$(Q)$(CC) $(CFLAGS) $^ -lelf -lz -o $@
$(OUTPUT)/runqslower.o: runqslower.h $(OUTPUT)/runqslower.skel.h \
$(OUTPUT)/runqslower.bpf.o
$(OUTPUT)/runqslower.bpf.o: $(OUTPUT)/vmlinux.h runqslower.h
$(OUTPUT)/%.skel.h: $(OUTPUT)/%.bpf.o | $(BPFTOOL)
$(call msg,GEN-SKEL,$@)
$(Q)$(BPFTOOL) gen skeleton $< > $@
$(OUTPUT)/%.bpf.o: %.bpf.c $(BPFOBJ) | $(OUTPUT)
$(call msg,BPF,$@)
$(Q)$(CLANG) -g -O2 -target bpf $(INCLUDES) \
-c $(filter %.c,$^) -o $@ && \
$(LLVM_STRIP) -g $@
$(OUTPUT)/%.o: %.c | $(OUTPUT)
$(call msg,CC,$@)
$(Q)$(CC) $(CFLAGS) $(INCLUDES) -c $(filter %.c,$^) -o $@
$(OUTPUT):
$(call msg,MKDIR,$@)
$(Q)mkdir -p $(OUTPUT)
$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(OUTPUT) $(BPFTOOL)
$(call msg,GEN,$@)
$(Q)if [ ! -e "$(VMLINUX_BTF_PATH)" ] ; then \
echo "Couldn't find kernel BTF; set VMLINUX_BTF to" \
"specify its location." >&2; \
exit 1;\
fi
$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF_PATH) format c > $@
$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)
$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) \
OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
$(DEFAULT_BPFTOOL):
$(Q)$(MAKE) $(submake_extras) -C ../bpftool \
prefix= OUTPUT=$(abs_out)/ DESTDIR=$(abs_out) install