linux/tools/testing/selftests/net/bpf.mk
Jakub Kicinski 3f584c211d selftests: net: extract BPF building logic from the Makefile
The BPF sample building code looks a little bit spaghetti-ish
so move it out to its own Makefile snippet. Similar in the spirit
to how we include lib.mk. libynl will soon get a similar snippet.

There is a small change hiding in the move, the relative
paths (../../.., ../.. etc) are replaced with variables
from lib.mk such as top_srcdir and selfdir.

Link: https://lore.kernel.org/r/20240423183542.3807234-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-24 20:15:45 -07:00

54 lines
1.8 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# Rules to generate bpf objs
CLANG ?= clang
SCRATCH_DIR := $(OUTPUT)/tools
BUILD_DIR := $(SCRATCH_DIR)/build
BPFDIR := $(top_srcdir)/tools/lib/bpf
APIDIR := $(top_srcdir)/tools/include/uapi
CCINCLUDE += -I$(selfdir)/bpf
CCINCLUDE += -I$(top_srcdir)/usr/include/
CCINCLUDE += -I$(SCRATCH_DIR)/include
BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a
MAKE_DIRS := $(BUILD_DIR)/libbpf
$(MAKE_DIRS):
$(call msg,MKDIR,,$@)
$(Q)mkdir -p $@
# Get Clang's default includes on this system, as opposed to those seen by
# '--target=bpf'. This fixes "missing" files on some architectures/distros,
# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
#
# Use '-idirafter': Don't interfere with include mechanics except where the
# build would have failed anyways.
define get_sys_includes
$(shell $(1) $(2) -v -E - </dev/null 2>&1 \
| sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
endef
ifneq ($(CROSS_COMPILE),)
CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
endif
CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
BPF_PROG_OBJS := $(patsubst %.c,$(OUTPUT)/%.o,$(wildcard *.bpf.c))
$(BPF_PROG_OBJS): $(OUTPUT)/%.o : %.c $(BPFOBJ) | $(MAKE_DIRS)
$(call msg,BPF_PROG,,$@)
$(Q)$(CLANG) -O2 -g --target=bpf $(CCINCLUDE) $(CLANG_SYS_INCLUDES) \
-c $< -o $@
$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \
$(APIDIR)/linux/bpf.h \
| $(BUILD_DIR)/libbpf
$(call msg,MAKE,,$@)
$(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \
EXTRA_CFLAGS='-g -O0' \
DESTDIR=$(SCRATCH_DIR) prefix= all install_headers
EXTRA_CLEAN += $(SCRATCH_DIR)