From c8c188679ccfc86d9c7bac57ecf4b8205a061a06 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 2 Mar 2017 16:00:26 -0300 Subject: [PATCH] tools build: Use the same CC for feature detection and actual build When build with: 'make CC=clang' we were not using that CC to do feature detection, which resulted in features being detected with gcc and then the actual tools being built with clang. Most of the time these compilers are compatible enough, so no problem was being noticed. As soon as a system with an old enough clang, one that hasn't the cpuid.h header is used, and a gcc with it, the "get_cpuid" feature will be found available but then code that will use can't be compiled. Noticed with this combination: / $ gcc --version | head -1 gcc (Alpine 6.3.0) 6.3.0 / $ clang --version | head -1 clang version 3.8.1 (tags/RELEASE_381/final) / $ cat /etc/alpine-release 3.5.0 / $ Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-60q18nvlvgpyfv7e2qqgx4ou@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/build/feature/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index ab1e2bbc2e96..09c9626ea666 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -53,8 +53,8 @@ FILES= \ FILES := $(addprefix $(OUTPUT),$(FILES)) -CC := $(CROSS_COMPILE)gcc -MD -CXX := $(CROSS_COMPILE)g++ -MD +CC ?= $(CROSS_COMPILE)gcc -MD +CXX ?= $(CROSS_COMPILE)g++ -MD PKG_CONFIG := $(CROSS_COMPILE)pkg-config LLVM_CONFIG ?= llvm-config -- 2.20.1