linux-yocto/tools/lib/bpf/Makefile

SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)

Most of this file is copied from tools/lib/traceevent/Makefile

RM ?= rm srctree := $(realpath $(srctree))

VERSION_SCRIPT := libbpf.map LIBBPF_VERSION := $(shell
grep -oE '^LIBBPF_([0-9.]+)' $(VERSION_SCRIPT) |
sort -rV | head -n1 | cut -d'_' -f2) LIBBPF_MAJOR_VERSION := $(word 1,$(subst ., ,$(LIBBPF_VERSION))) LIBBPF_MINOR_VERSION := $(word 2,$(subst ., ,$(LIBBPF_VERSION)))

MAKEFLAGS += --no-print-directory

This will work when bpf is built in tools env. where srctree

isn't set and when invoked from selftests build, where srctree

is a ".". building_out_of_srctree is undefined for in srctree

builds

ifndef building_out_of_srctree srctree := $(patsubst %/,%,$(dir $(CURDIR))) srctree := $(patsubst %/,%,$(dir $(srctree))) srctree := $(patsubst %/,%,$(dir $(srctree))) #$(info Determined 'srctree' to be $(srctree)) endif

INSTALL = install

Use DESTDIR for installing into a different root directory.

This is useful for building a package. The program will be

installed in this directory as if it was the root directory.

Then the build tool can move it later.

DESTDIR ?= DESTDIR_SQ = '$(subst ',''',$(DESTDIR))'

include $(srctree)/tools/scripts/Makefile.arch

ifeq ($(LP64), 1) libdir_relative = lib64 else libdir_relative = lib endif

prefix ?= /usr/local libdir = $(prefix)/$(libdir_relative) man_dir = $(prefix)/share/man man_dir_SQ = '$(subst ',''',$(man_dir))'

export man_dir man_dir_SQ INSTALL export DESTDIR DESTDIR_SQ

include $(srctree)/tools/scripts/Makefile.include

copy a bit from Linux kbuild

ifeq ("$(origin V)", "command line") VERBOSE = $(V) endif ifndef VERBOSE VERBOSE = 0 endif

INCLUDES = -I$(or $(OUTPUT),.)
-I$(srctree)/tools/include -I$(srctree)/tools/include/uapi

export prefix libdir src obj

Shell quotes

libdir_SQ = $(subst ',''',$(libdir)) libdir_relative_SQ = $(subst ',''',$(libdir_relative))

OBJ = $@ N =

LIB_TARGET = libbpf.a libbpf.so.$(LIBBPF_VERSION) LIB_FILE = libbpf.a libbpf.so* PC_FILE = libbpf.pc

Set compile option CFLAGS

ifdef EXTRA_CFLAGS CFLAGS := $(EXTRA_CFLAGS) else CFLAGS := -g -O2 endif

Append required CFLAGS

override CFLAGS += -std=gnu89 override CFLAGS += $(EXTRA_WARNINGS) -Wno-switch-enum override CFLAGS += -Werror -Wall override CFLAGS += $(INCLUDES) override CFLAGS += -fvisibility=hidden override CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 override CFLAGS += $(CLANG_CROSS_FLAGS)

flags specific for shared library

SHLIB_FLAGS := -DSHARED -fPIC

ifeq ($(VERBOSE),1) Q = else Q = @ endif

Disable command line variables (CFLAGS) override from top

level Makefile (perf), otherwise build Makefile will get

the same command line setup.

MAKEOVERRIDES=

all:

export srctree OUTPUT CC LD CFLAGS V include $(srctree)/tools/build/Makefile.include

SHARED_OBJDIR := $(OUTPUT)sharedobjs/ STATIC_OBJDIR := $(OUTPUT)staticobjs/ BPF_IN_SHARED := $(SHARED_OBJDIR)libbpf-in.o BPF_IN_STATIC := $(STATIC_OBJDIR)libbpf-in.o BPF_HELPER_DEFS := $(OUTPUT)bpf_helper_defs.h BPF_GENERATED := $(BPF_HELPER_DEFS)

LIB_TARGET := $(addprefix $(OUTPUT),$(LIB_TARGET)) LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) PC_FILE := $(addprefix $(OUTPUT),$(PC_FILE))

TAGS_PROG := $(if $(shell which etags 2>/dev/null),etags,ctags)

GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) |
cut -d "@" -f1 | sed 's/v[0-9][0-9][0-9].//' |
sed 's/[.]//' |
awk '/GLOBAL/ && /DEFAULT/ && !/UND|ABS/ {print $$NF}' |
sort -u | wc -l) VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so |
sed 's/[.*]//' |
awk '/GLOBAL/ && /DEFAULT/ && !/UND|ABS/ {print $$NF}' |
grep -Eo '[^ ]+@LIBBPF' | cut -d@ -f1 | sort -u | wc -l)

CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)

all: fixdep $(Q)$(MAKE) all_cmd

all_cmd: $(CMD_TARGETS) check

$(BPF_IN_SHARED): force $(BPF_GENERATED) @(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && (
(diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) ||
echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true @(test -f ../../include/uapi/linux/bpf_common.h -a -f ../../../include/uapi/linux/bpf_common.h && (
(diff -B ../../include/uapi/linux/bpf_common.h ../../../include/uapi/linux/bpf_common.h >/dev/null) ||
echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf_common.h' differs from latest version at 'include/uapi/linux/bpf_common.h'" >&2 )) || true @(test -f ../../include/uapi/linux/if_xdp.h -a -f ../../../include/uapi/linux/if_xdp.h && (
(diff -B ../../include/uapi/linux/if_xdp.h ../../../include/uapi/linux/if_xdp.h >/dev/null) ||
echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)"

$(BPF_IN_STATIC): force $(BPF_GENERATED) $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)

$(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h $(QUIET_GEN)$(srctree)/scripts/bpf_doc.py --header
--file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS)

$(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION)

$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED) $(VERSION_SCRIPT) $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS)
--shared -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION)
-Wl,--version-script=$(VERSION_SCRIPT) $< -lelf -lz -o $@ @ln -sf $(@F) $(OUTPUT)libbpf.so @ln -sf $(@F) $(OUTPUT)libbpf.so.$(LIBBPF_MAJOR_VERSION)

$(OUTPUT)libbpf.a: $(BPF_IN_STATIC) $(QUIET_LINK)$(RM) -f $@; $(AR) rcs $@ $^

$(OUTPUT)libbpf.pc: $(QUIET_GEN)sed -e "s|@PREFIX@|$(prefix)|"
-e "s|@LIBDIR@|$(libdir_SQ)|"
-e "s|@VERSION@|$(LIBBPF_VERSION)|"
< libbpf.pc.template > $@

check: check_abi check_version

check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT) @if [ "$(GLOBAL_SYM_COUNT)" != "$(VERSIONED_SYM_COUNT)" ]; then
echo "Warning: Num of global symbols in $(BPF_IN_SHARED)"
"($(GLOBAL_SYM_COUNT)) does NOT match with num of"
"versioned symbols in $^ ($(VERSIONED_SYM_COUNT))."
"Please make sure all LIBBPF_API symbols are"
"versioned in $(VERSION_SCRIPT)." >&2;
readelf -s --wide $(BPF_IN_SHARED) |
cut -d "@" -f1 | sed 's/v[0-9][0-9][0-9].//' |
sed 's/[.]//' |
awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'|
sort -u > $(OUTPUT)libbpf_global_syms.tmp;
readelf --dyn-syms --wide $(OUTPUT)libbpf.so |
sed 's/[.*]//' |
awk '/GLOBAL/ && /DEFAULT/ && !/UND|ABS/ {print $$NF}'|
grep -Eo '[^ ]+@LIBBPF' | cut -d@ -f1 |
sort -u > $(OUTPUT)libbpf_versioned_syms.tmp;
diff -u $(OUTPUT)libbpf_global_syms.tmp
$(OUTPUT)libbpf_versioned_syms.tmp;
rm $(OUTPUT)libbpf_global_syms.tmp
$(OUTPUT)libbpf_versioned_syms.tmp;
exit 1;
fi

HDR_MAJ_VERSION := $(shell grep -oE '^$(pound)define LIBBPF_MAJOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3) HDR_MIN_VERSION := $(shell grep -oE '^$(pound)define LIBBPF_MINOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3)

check_version: $(VERSION_SCRIPT) libbpf_version.h @if [ "$(HDR_MAJ_VERSION)" != "$(LIBBPF_MAJOR_VERSION)" ]; then
echo "Error: libbpf major version mismatch detected: "
"'$(HDR_MAJ_VERSION)' != '$(LIBBPF_MAJOR_VERSION)'" >&2;
exit 1;
fi @if [ "$(HDR_MIN_VERSION)" != "$(LIBBPF_MINOR_VERSION)" ]; then
echo "Error: libbpf minor version mismatch detected: "
"'$(HDR_MIN_VERSION)' != '$(LIBBPF_MINOR_VERSION)'" >&2;
exit 1;
fi

define do_install_mkdir if [ ! -d '$(DESTDIR_SQ)$1' ]; then
$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$1';
fi endef

define do_install if [ ! -d '$(DESTDIR_SQ)$2' ]; then
$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2';
fi;
$(INSTALL) $(if $3,-m $3,) $1 '$(DESTDIR_SQ)$2' endef

install_lib: all_cmd $(call QUIET_INSTALL, $(LIB_TARGET))
$(call do_install_mkdir,$(libdir_SQ));
cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)

SRC_HDRS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h
bpf_helpers.h bpf_tracing.h bpf_endian.h bpf_core_read.h
skel_internal.h libbpf_version.h usdt.bpf.h GEN_HDRS := $(BPF_GENERATED)

INSTALL_PFX := $(DESTDIR)$(prefix)/include/bpf INSTALL_SRC_HDRS := $(addprefix $(INSTALL_PFX)/, $(SRC_HDRS)) INSTALL_GEN_HDRS := $(addprefix $(INSTALL_PFX)/, $(notdir $(GEN_HDRS)))

$(INSTALL_SRC_HDRS): $(INSTALL_PFX)/%.h: %.h $(call QUIET_INSTALL, $@)
$(call do_install,$<,$(prefix)/include/bpf,644)

$(INSTALL_GEN_HDRS): $(INSTALL_PFX)/%.h: $(OUTPUT)%.h $(call QUIET_INSTALL, $@)
$(call do_install,$<,$(prefix)/include/bpf,644)

install_headers: $(BPF_GENERATED) $(INSTALL_SRC_HDRS) $(INSTALL_GEN_HDRS) $(call QUIET_INSTALL, libbpf_headers)

install_pkgconfig: $(PC_FILE) $(call QUIET_INSTALL, $(PC_FILE))
$(call do_install,$(PC_FILE),$(libdir_SQ)/pkgconfig,644)

install: install_lib install_pkgconfig install_headers

clean: $(call QUIET_CLEAN, libbpf) $(RM) -rf $(CMD_TARGETS)
~ ..d .*.cmd LIBBPF-CFLAGS $(BPF_GENERATED)
$(SHARED_OBJDIR) $(STATIC_OBJDIR)
$(addprefix $(OUTPUT),
*.o *.a *.so *.so.$(LIBBPF_MAJOR_VERSION) *.pc)

PHONY += force cscope tags check check_abi check_version force:

cscope: ls *.c *.h > cscope.files cscope -b -q -I $(srctree)/include -f cscope.out

tags: $(RM) -f TAGS tags ls *.c *.h | xargs $(TAGS_PROG) -a

Declare the contents of the .PHONY variable as phony. We keep that

information in a variable so we can use it in if_changed and friends.

.PHONY: $(PHONY)

Delete partially updated (corrupted) files on error

.DELETE_ON_ERROR:

help: @echo 'libbpf common targets:' @echo ' HINT: use "V=1" to enable verbose build' @echo ' all - build libraries and pkgconfig' @echo ' clean - remove all generated files' @echo ' check - check ABI and version info' @echo '' @echo 'libbpf install targets:' @echo ' HINT: use "prefix"(defaults to "/usr/local") or "DESTDIR" (defaults to "/")' @echo ' to adjust target destination, e.g. "make prefix=/usr/local install"' @echo ' install - build and install all headers, libraries and pkgconfig' @echo ' install_headers - install only headers to include/bpf' @echo '' @echo 'libbpf make targets:' @echo ' tags - use ctags to make tag information for source code browsing' @echo ' cscope - use cscope to make interactive source code browsing database'