projects/linux·blob master · refs

53 lines · 1.8 KiB

1# SPDX-License-Identifier: GPL-2.0
2# Rules to generate bpf objs
3CLANG ?= clang
4SCRATCH_DIR := $(OUTPUT)/tools
5BUILD_DIR := $(SCRATCH_DIR)/build
6BPFDIR := $(top_srcdir)/tools/lib/bpf
7APIDIR := $(top_srcdir)/tools/include/uapi
8
9CCINCLUDE += -I$(selfdir)/bpf
10CCINCLUDE += -I$(top_srcdir)/usr/include/
11CCINCLUDE += -I$(SCRATCH_DIR)/include
12
13BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a
14
15MAKE_DIRS := $(BUILD_DIR)/libbpf
16$(MAKE_DIRS):
17 $(call msg,MKDIR,,$@)
18 $(Q)mkdir -p $@
19
20# Get Clang's default includes on this system, as opposed to those seen by
21# '--target=bpf'. This fixes "missing" files on some architectures/distros,
22# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
23#
24# Use '-idirafter': Don't interfere with include mechanics except where the
25# build would have failed anyways.
26define get_sys_includes
27$(shell $(1) $(2) -v -E - </dev/null 2>&1 \
28 | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
29$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
30endef
31
32ifneq ($(CROSS_COMPILE),)
33CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
34endif
35
36CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
37
38BPF_PROG_OBJS := $(patsubst %.c,$(OUTPUT)/%.o,$(wildcard *.bpf.c))
39
40$(BPF_PROG_OBJS): $(OUTPUT)/%.o : %.c $(BPFOBJ) | $(MAKE_DIRS)
41 $(call msg,BPF_PROG,,$@)
42 $(Q)$(CLANG) -O2 -g --target=bpf $(CCINCLUDE) $(CLANG_SYS_INCLUDES) \
43 -c $< -o $@
44
45$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \
46 $(APIDIR)/linux/bpf.h \
47 | $(BUILD_DIR)/libbpf
48 $(call msg,MAKE,,$@)
49 $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \
50 EXTRA_CFLAGS='-g -O0' \
51 DESTDIR=$(SCRATCH_DIR) prefix= all install_headers
52
53EXTRA_CLEAN += $(SCRATCH_DIR)