Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 34/35] tools build: Use the same CC for feature detection and actual build | Date | Mon, 6 Mar 2017 16:38:24 -0300 |
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From: Arnaldo Carvalho de Melo <acme@redhat.com>
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 <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-60q18nvlvgpyfv7e2qqgx4ou@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- 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 -- 2.9.3
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