kumquat-buildroot/package/libbpf/libbpf.mk

################################################################################
#
# libbpf
#
################################################################################

LIBBPF_VERSION = 0.8.0
LIBBPF_SITE = $(call github,libbpf,libbpf,v$(LIBBPF_VERSION))
LIBBPF_LICENSE = GPL-2.0, LGPL-2.1, BSD-2-Clause
LIBBPF_LICENSE_FILES = LICENSE LICENSE.BSD-2-Clause LICENSE.LGPL-2.1
LIBBPF_CPE_ID_VENDOR = libbpf_project
LIBBPF_DEPENDENCIES = host-bison host-flex host-pkgconf elfutils zlib
HOST_LIBBPF_DEPENDENCIES = host-bison host-flex host-pkgconf host-elfutils host-zlib
LIBBPF_INSTALL_STAGING = YES

define LIBBPF_BUILD_CMDS
	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) \
		-C $(@D)/src
endef

# bpf/bpf.h installed by libbpf uses bpf_iter_link_info that was added since
# kernel 5.9, so we need to update some uapi headers in STAGING_DIR if the
# toolchain is build with linux-headers < 5.9.
# Otherwise bpf/bpf.h is broken due to out of date linux/bpf.h installed by the
# toolchain.
# https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a5cbe05a6673b85bed2a63ffcfea6a96c6410cff
ifeq ($(BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_9),)
LIBBPF_UPDATE_UAPI_HEADERS = install_uapi_headers
endif

define LIBBPF_INSTALL_STAGING_CMDS
	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) \
		-C $(@D)/src install $(LIBBPF_UPDATE_UAPI_HEADERS) \
		DESTDIR=$(STAGING_DIR)
endef

define LIBBPF_INSTALL_TARGET_CMDS
	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) \
		-C $(@D)/src install DESTDIR=$(TARGET_DIR)
endef

# We need to install_uapi_headers so we have btf.h to compile
# host-pahole.
# Nonetheless, this target adds bpf.h which generates a conflict when
# building the kernel:
# In file included from libbpf_internal.h:17:0, from strset.c:9:
# relo_core.h:10:6: error: nested redefinition of 'enum bpf_core_relo_kind'
# enum bpf_core_relo_kind {
# ^~~~~~~~~~~~~~~~~~
# relo_core.h:10:6: error: redeclaration of 'enum bpf_core_relo_kind'
# In file included from libbpf_legacy.h:13:0,
# 		from libbpf_internal.h:16,
# 		from strset.c:9:
# /home/francis/buildroot/output/host/include/linux/bpf.h:6497:6: note: originally defined here
# enum bpf_core_relo_kind {
# So, better to remove remove it now since we do not need it to build
# host-pahole, the only user of host-libbpf.
define HOST_LIBBPF_INSTALL_CMDS
	$(HOST_MAKE_ENV) $(HOST_CONFIGURE_OPTS) $(MAKE) \
		-C $(@D)/src install install_uapi_headers DESTDIR=$(HOST_DIR)
	rm $(HOST_DIR)/include/linux/bpf.h
endef

$(eval $(generic-package))
$(eval $(host-generic-package))