linux/tools/bpf/bpftool/Makefile
Viktor Malik 0513eeee86 bpftool: Prevent setting duplicate _GNU_SOURCE in Makefile
When building selftests with CFLAGS set via env variable, the value of
CFLAGS is propagated into bpftool Makefile (called from selftests
Makefile). This makes the compilation fail as _GNU_SOURCE is defined two
times - once from selftests Makefile (by including lib.mk) and once from
bpftool Makefile (by calling `llvm-config --cflags`):

    $ CFLAGS="" make -C tools/testing/selftests/bpf
    [...]
    CC      /bpf-next/tools/testing/selftests/bpf/tools/build/bpftool/btf.o
    <command-line>: error: "_GNU_SOURCE" redefined [-Werror]
    <command-line>: note: this is the location of the previous definition
    cc1: all warnings being treated as errors
    [...]

Filter out -D_GNU_SOURCE from the result of `llvm-config --cflags` in
bpftool Makefile to prevent this error.

Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/acec3108b62d4df1436cda777e58e93e033ac7a7.1730449390.git.vmalik@redhat.com
2024-11-01 12:37:01 -07:00

302 lines
9.4 KiB
Makefile

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
include ../../scripts/Makefile.include
ifeq ($(srctree),)
srctree := $(patsubst %/,%,$(dir $(CURDIR)))
srctree := $(patsubst %/,%,$(dir $(srctree)))
srctree := $(patsubst %/,%,$(dir $(srctree)))
endif
ifeq ($(V),1)
Q =
else
Q = @
endif
BPF_DIR = $(srctree)/tools/lib/bpf
ifneq ($(OUTPUT),)
_OUTPUT := $(OUTPUT)
else
_OUTPUT := $(CURDIR)/
endif
BOOTSTRAP_OUTPUT := $(_OUTPUT)bootstrap/
LIBBPF_OUTPUT := $(_OUTPUT)libbpf/
LIBBPF_DESTDIR := $(LIBBPF_OUTPUT)
LIBBPF_INCLUDE := $(LIBBPF_DESTDIR)include
LIBBPF_HDRS_DIR := $(LIBBPF_INCLUDE)/bpf
LIBBPF := $(LIBBPF_OUTPUT)libbpf.a
LIBBPF_BOOTSTRAP_OUTPUT := $(BOOTSTRAP_OUTPUT)libbpf/
LIBBPF_BOOTSTRAP_DESTDIR := $(LIBBPF_BOOTSTRAP_OUTPUT)
LIBBPF_BOOTSTRAP_INCLUDE := $(LIBBPF_BOOTSTRAP_DESTDIR)include
LIBBPF_BOOTSTRAP_HDRS_DIR := $(LIBBPF_BOOTSTRAP_INCLUDE)/bpf
LIBBPF_BOOTSTRAP := $(LIBBPF_BOOTSTRAP_OUTPUT)libbpf.a
# We need to copy hashmap.h, nlattr.h, relo_core.h and libbpf_internal.h
# which are not otherwise exported by libbpf, but still required by bpftool.
LIBBPF_INTERNAL_HDRS := $(addprefix $(LIBBPF_HDRS_DIR)/,hashmap.h nlattr.h relo_core.h libbpf_internal.h)
LIBBPF_BOOTSTRAP_INTERNAL_HDRS := $(addprefix $(LIBBPF_BOOTSTRAP_HDRS_DIR)/,hashmap.h relo_core.h libbpf_internal.h)
$(LIBBPF_OUTPUT) $(BOOTSTRAP_OUTPUT) $(LIBBPF_BOOTSTRAP_OUTPUT) $(LIBBPF_HDRS_DIR) $(LIBBPF_BOOTSTRAP_HDRS_DIR):
$(QUIET_MKDIR)mkdir -p $@
$(LIBBPF): $(wildcard $(BPF_DIR)/*.[ch] $(BPF_DIR)/Makefile) | $(LIBBPF_OUTPUT)
$(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) \
DESTDIR=$(LIBBPF_DESTDIR:/=) prefix= $(LIBBPF) install_headers
$(LIBBPF_INTERNAL_HDRS): $(LIBBPF_HDRS_DIR)/%.h: $(BPF_DIR)/%.h | $(LIBBPF_HDRS_DIR)
$(call QUIET_INSTALL, $@)
$(Q)install -m 644 -t $(LIBBPF_HDRS_DIR) $<
$(LIBBPF_BOOTSTRAP): $(wildcard $(BPF_DIR)/*.[ch] $(BPF_DIR)/Makefile) | $(LIBBPF_BOOTSTRAP_OUTPUT)
$(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_BOOTSTRAP_OUTPUT) \
DESTDIR=$(LIBBPF_BOOTSTRAP_DESTDIR:/=) prefix= \
ARCH= CROSS_COMPILE= CC="$(HOSTCC)" LD="$(HOSTLD)" AR="$(HOSTAR)" $@ install_headers
$(LIBBPF_BOOTSTRAP_INTERNAL_HDRS): $(LIBBPF_BOOTSTRAP_HDRS_DIR)/%.h: $(BPF_DIR)/%.h | $(LIBBPF_BOOTSTRAP_HDRS_DIR)
$(call QUIET_INSTALL, $@)
$(Q)install -m 644 -t $(LIBBPF_BOOTSTRAP_HDRS_DIR) $<
$(LIBBPF)-clean: FORCE | $(LIBBPF_OUTPUT)
$(call QUIET_CLEAN, libbpf)
$(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) clean >/dev/null
$(LIBBPF_BOOTSTRAP)-clean: FORCE | $(LIBBPF_BOOTSTRAP_OUTPUT)
$(call QUIET_CLEAN, libbpf-bootstrap)
$(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_BOOTSTRAP_OUTPUT) clean >/dev/null
prefix ?= /usr/local
bash_compdir ?= /usr/share/bash-completion/completions
CFLAGS += -O2
CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers
CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS))
CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
-I$(or $(OUTPUT),.) \
-I$(LIBBPF_INCLUDE) \
-I$(srctree)/kernel/bpf/ \
-I$(srctree)/tools/include \
-I$(srctree)/tools/include/uapi
ifneq ($(BPFTOOL_VERSION),)
CFLAGS += -DBPFTOOL_VERSION='"$(BPFTOOL_VERSION)"'
endif
ifneq ($(EXTRA_CFLAGS),)
CFLAGS += $(EXTRA_CFLAGS)
endif
ifneq ($(EXTRA_LDFLAGS),)
LDFLAGS += $(EXTRA_LDFLAGS)
endif
HOST_CFLAGS := $(subst -I$(LIBBPF_INCLUDE),-I$(LIBBPF_BOOTSTRAP_INCLUDE),\
$(subst $(CLANG_CROSS_FLAGS),,$(CFLAGS)))
HOST_LDFLAGS := $(LDFLAGS)
INSTALL ?= install
RM ?= rm -f
FEATURE_USER = .bpftool
FEATURE_TESTS := clang-bpf-co-re
FEATURE_TESTS += llvm
FEATURE_TESTS += libcap
FEATURE_TESTS += libbfd
FEATURE_TESTS += libbfd-liberty
FEATURE_TESTS += libbfd-liberty-z
FEATURE_TESTS += disassembler-four-args
FEATURE_TESTS += disassembler-init-styled
FEATURE_DISPLAY := clang-bpf-co-re
FEATURE_DISPLAY += llvm
FEATURE_DISPLAY += libcap
FEATURE_DISPLAY += libbfd
FEATURE_DISPLAY += libbfd-liberty
FEATURE_DISPLAY += libbfd-liberty-z
check_feat := 1
NON_CHECK_FEAT_TARGETS := clean uninstall doc doc-clean doc-install doc-uninstall
ifdef MAKECMDGOALS
ifeq ($(filter-out $(NON_CHECK_FEAT_TARGETS),$(MAKECMDGOALS)),)
check_feat := 0
endif
endif
ifeq ($(check_feat),1)
ifeq ($(FEATURES_DUMP),)
include $(srctree)/tools/build/Makefile.feature
else
include $(FEATURES_DUMP)
endif
endif
LIBS = $(LIBBPF) -lelf -lz
LIBS_BOOTSTRAP = $(LIBBPF_BOOTSTRAP) -lelf -lz
ifeq ($(feature-libcap), 1)
CFLAGS += -DUSE_LIBCAP
LIBS += -lcap
endif
include $(wildcard $(OUTPUT)*.d)
all: $(OUTPUT)bpftool
SRCS := $(wildcard *.c)
ifeq ($(feature-llvm),1)
# If LLVM is available, use it for JIT disassembly
CFLAGS += -DHAVE_LLVM_SUPPORT
LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
# llvm-config always adds -D_GNU_SOURCE, however, it may already be in CFLAGS
# (e.g. when bpftool build is called from selftests build as selftests
# Makefile includes lib.mk which sets -D_GNU_SOURCE) which would cause
# compilation error due to redefinition. Let's filter it out here.
CFLAGS += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags))
LIBS += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static)
LIBS += $(shell $(LLVM_CONFIG) --system-libs $(LLVM_CONFIG_LIB_COMPONENTS))
LIBS += -lstdc++
endif
LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
else
# Fall back on libbfd
ifeq ($(feature-libbfd),1)
LIBS += -lbfd -ldl -lopcodes
else ifeq ($(feature-libbfd-liberty),1)
LIBS += -lbfd -ldl -lopcodes -liberty
else ifeq ($(feature-libbfd-liberty-z),1)
LIBS += -lbfd -ldl -lopcodes -liberty -lz
endif
# If one of the above feature combinations is set, we support libbfd
ifneq ($(filter -lbfd,$(LIBS)),)
CFLAGS += -DHAVE_LIBBFD_SUPPORT
# Libbfd interface changed over time, figure out what we need
ifeq ($(feature-disassembler-four-args), 1)
CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
endif
ifeq ($(feature-disassembler-init-styled), 1)
CFLAGS += -DDISASM_INIT_STYLED
endif
endif
endif
ifeq ($(filter -DHAVE_LLVM_SUPPORT -DHAVE_LIBBFD_SUPPORT,$(CFLAGS)),)
# No support for JIT disassembly
SRCS := $(filter-out jit_disasm.c,$(SRCS))
endif
BPFTOOL_BOOTSTRAP := $(BOOTSTRAP_OUTPUT)bpftool
BOOTSTRAP_OBJS = $(addprefix $(BOOTSTRAP_OUTPUT),main.o common.o json_writer.o gen.o btf.o)
$(BOOTSTRAP_OBJS): $(LIBBPF_BOOTSTRAP)
OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
$(OBJS): $(LIBBPF) $(LIBBPF_INTERNAL_HDRS)
VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
$(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
../../../vmlinux \
/sys/kernel/btf/vmlinux \
/boot/vmlinux-$(shell uname -r)
VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
bootstrap: $(BPFTOOL_BOOTSTRAP)
ifneq ($(VMLINUX_BTF)$(VMLINUX_H),)
ifeq ($(feature-clang-bpf-co-re),1)
BUILD_BPF_SKELS := 1
ifeq ($(VMLINUX_H),)
$(OUTPUT)vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL_BOOTSTRAP)
$(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) btf dump file $< format c > $@
else
$(OUTPUT)vmlinux.h: $(VMLINUX_H)
$(Q)cp "$(VMLINUX_H)" $@
endif
$(OUTPUT)%.bpf.o: skeleton/%.bpf.c $(OUTPUT)vmlinux.h $(LIBBPF_BOOTSTRAP)
$(QUIET_CLANG)$(CLANG) \
-I$(or $(OUTPUT),.) \
-I$(srctree)/tools/include/uapi/ \
-I$(LIBBPF_BOOTSTRAP_INCLUDE) \
-g -O2 -Wall -fno-stack-protector \
--target=bpf -c $< -o $@
$(Q)$(LLVM_STRIP) -g $@
$(OUTPUT)%.skel.h: $(OUTPUT)%.bpf.o $(BPFTOOL_BOOTSTRAP)
$(QUIET_GEN)$(BPFTOOL_BOOTSTRAP) gen skeleton $< > $@
$(OUTPUT)prog.o: $(OUTPUT)profiler.skel.h
$(OUTPUT)pids.o: $(OUTPUT)pid_iter.skel.h
endif
endif
CFLAGS += $(if $(BUILD_BPF_SKELS),,-DBPFTOOL_WITHOUT_SKELETONS)
$(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD $< -o $@
$(BPFTOOL_BOOTSTRAP): $(BOOTSTRAP_OBJS) $(LIBBPF_BOOTSTRAP)
$(QUIET_LINK)$(HOSTCC) $(HOST_CFLAGS) $(HOST_LDFLAGS) $(BOOTSTRAP_OBJS) $(LIBS_BOOTSTRAP) -o $@
$(OUTPUT)bpftool: $(OBJS) $(LIBBPF)
$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(OBJS) $(LIBS) -o $@
$(BOOTSTRAP_OUTPUT)%.o: %.c $(LIBBPF_BOOTSTRAP_INTERNAL_HDRS) | $(BOOTSTRAP_OUTPUT)
$(QUIET_CC)$(HOSTCC) $(HOST_CFLAGS) -c -MMD $< -o $@
$(OUTPUT)%.o: %.c
$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD $< -o $@
feature-detect-clean:
$(call QUIET_CLEAN, feature-detect)
$(Q)$(MAKE) -C $(srctree)/tools/build/feature/ clean >/dev/null
clean: $(LIBBPF)-clean $(LIBBPF_BOOTSTRAP)-clean feature-detect-clean
$(call QUIET_CLEAN, bpftool)
$(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d
$(Q)$(RM) -- $(OUTPUT)*.skel.h $(OUTPUT)vmlinux.h
$(Q)$(RM) -r -- $(LIBBPF_OUTPUT) $(BOOTSTRAP_OUTPUT)
$(call QUIET_CLEAN, core-gen)
$(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool
$(Q)$(RM) -r -- $(OUTPUT)feature/
install-bin: $(OUTPUT)bpftool
$(call QUIET_INSTALL, bpftool)
$(Q)$(INSTALL) -m 0755 -d $(DESTDIR)$(prefix)/sbin
$(Q)$(INSTALL) $(OUTPUT)bpftool $(DESTDIR)$(prefix)/sbin/bpftool
install: install-bin
$(Q)$(INSTALL) -m 0755 -d $(DESTDIR)$(bash_compdir)
$(Q)$(INSTALL) -m 0644 bash-completion/bpftool $(DESTDIR)$(bash_compdir)
uninstall:
$(call QUIET_UNINST, bpftool)
$(Q)$(RM) -- $(DESTDIR)$(prefix)/sbin/bpftool
$(Q)$(RM) -- $(DESTDIR)$(bash_compdir)/bpftool
doc:
$(call descend,Documentation)
doc-clean:
$(call descend,Documentation,clean)
doc-install:
$(call descend,Documentation,install)
doc-uninstall:
$(call descend,Documentation,uninstall)
FORCE:
.SECONDARY:
.PHONY: all FORCE bootstrap clean install-bin install uninstall
.PHONY: doc doc-clean doc-install doc-uninstall
.DEFAULT_GOAL := all
# Delete partially updated (corrupted) files on error
.DELETE_ON_ERROR: