From 0c3d6fd4b89c1a6393283249cdd0bd484ad8f2e5 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 21 Jun 2023 16:17:19 -0700 Subject: [PATCH] tools: ynl: improve the direct-include header guard logic Przemek suggests that I shouldn't accuse GCC of witchcraft, there is a simpler explanation for why we need manual define. scripts/headers_install.sh modifies the guard, removing _UAPI. That's why including a kernel header from the tree and from /usr leads to duplicate definitions. This also solves the mystery of why I needed to include the header conditionally. I had the wrong guards for most cases but ethtool. Suggested-by: Przemek Kitszel Reviewed-by: Przemek Kitszel Link: https://lore.kernel.org/r/20230621231719.2728928-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- tools/net/ynl/Makefile.deps | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/tools/net/ynl/Makefile.deps b/tools/net/ynl/Makefile.deps index 524fc4bb586b..f842bc66b967 100644 --- a/tools/net/ynl/Makefile.deps +++ b/tools/net/ynl/Makefile.deps @@ -9,20 +9,12 @@ 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$(hdr_guard). -# And we need to define HASH indirectly because GNU Make 4.2 wants it escaped -# and Gnu Make 4.4 wants it without escaping. +# scripts/headers_install.sh strips "_UAPI" from header guards so we +# need the explicit -D matching what's in /usr, to avoid multiple definitions. -HASH := \# +get_hdr_inc=-D$(1) -include $(UAPI_PATH)/linux/$(2) -get_hdr_inc=$(if $(shell echo "$(HASH)include " | \ - cpp >>/dev/null 2>/dev/null && echo yes),\ - -D$(1) -include $(UAPI_PATH)/linux/$(2)) - -CFLAGS_devlink:=$(call get_hdr_inc,_UAPI_LINUX_DEVLINK_H_,devlink.h) +CFLAGS_devlink:=$(call get_hdr_inc,_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:=$(call get_hdr_inc,_UAPI_LINUX_NETDEV_H,netdev.h) +CFLAGS_handshake:=$(call get_hdr_inc,_LINUX_HANDSHAKE_H,handshake.h) +CFLAGS_netdev:=$(call get_hdr_inc,_LINUX_NETDEV_H,netdev.h)