# SPDX-License-Identifier: GPL-2.0

# Try to include uAPI headers from the kernel uapi/ path.
# Most code under tools/ requires the respective kernel uAPI headers
# to be copied to tools/include. The duplication is annoying.
# All the family headers should be self-contained. We avoid the copying
# by selectively including just the uAPI header of the family directly
# from the kernel sources.

UAPI_PATH:=../../../../include/uapi/

# If the header does not exist at all in the system path - let the
# compiler fall back to the kernel header via -Idirafter.
# GCC seems to ignore header guard if the header is different, so we need
# to specify the -D$(hdr_guard).
# And we need to define HASH indirectly because GNU Make 4.2 wants it escaped
# and Gnu Make 4.4 wants it without escaping.

HASH := \#

get_hdr_inc=$(if $(shell echo "$(HASH)include <linux/$(2)>" | \
			 cpp >>/dev/null 2>/dev/null && echo yes),\
		-D$(1) -include $(UAPI_PATH)/linux/$(2))

CFLAGS_devlink:=$(call get_hdr_inc,_UAPI_LINUX_DEVLINK_H_,devlink.h)
CFLAGS_ethtool:=$(call get_hdr_inc,_LINUX_ETHTOOL_NETLINK_H_,ethtool_netlink.h)
CFLAGS_handshake:=$(call get_hdr_inc,_UAPI_LINUX_HANDSHAKE_H,handshake.h)
CFLAGS_netdev:=$(call get_hdr_inc,_UAPI_LINUX_NETDEV_H,netdev.h)