From 167381f3eac0d9db82ad2c565048bfea8fb01574 Mon Sep 17 00:00:00 2001 From: Sirio Balmelli Date: Mon, 21 May 2018 09:00:03 +0200 Subject: [PATCH] selftests/bpf: Makefile fix "missing" headers on build with -idirafter Selftests fail to build on several distros/architectures because of missing headers files. On a Ubuntu/x86_64 some missing headers are: asm/byteorder.h, asm/socket.h, asm/sockios.h On a Debian/arm32 build already fails at sys/cdefs.h In both cases, these already exist in /usr/include/, but Clang does not include these when using '-target bpf' flag, since it is no longer compiling against the host architecture. The solution is to: - run Clang without '-target bpf' and extract the include chain for the current system - add these to the bpf build with '-idirafter' The choice of -idirafter is to catch this error without injecting unexpected include behavior: if an arch-specific tree is built for bpf in the future, this will be correctly found by Clang. Signed-off-by: Sirio Balmelli Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/Makefile | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 1eb0fa2..49618c9 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -84,7 +84,17 @@ else CPU ?= generic endif +# Get Clang's default includes on this system, as opposed to those seen by +# '-target bpf'. This fixes "missing" files on some architectures/distros, +# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc. +# +# Use '-idirafter': Don't interfere with include mechanics except where the +# build would have failed anyways. +CLANG_SYS_INCLUDES := $(shell $(CLANG) -v -E - &1 \ + | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') + CLANG_FLAGS = -I. -I./include/uapi -I../../../include/uapi \ + $(CLANG_SYS_INCLUDES) \ -Wno-compare-distinct-pointer-types $(OUTPUT)/test_l4lb_noinline.o: CLANG_FLAGS += -fno-inline -- 2.7.4