since 6aa7de0, we failed to build perf with C++(clang) to fix the following compile errors -------------- lizhijian@haswell-OptiPlex-9020:~/lkp/linux/tools/perf$ make LLVM_CONFIG=/usr/bin/llvm-config-3.9 LIBCLANGLLVM=1 ... CC util/probe-finder.o In file included from /home/lizj/linux/tools/perf/util/util.h:13:0, from /home/lizj/linux/tools/perf/util/util-cxx.h:20, from util/c++/clang-c.h:5, from util/c++/clang-test.cpp:2: /home/lizj/linux/tools/include/asm/../../arch/x86/include/asm/atomic.h: In function ‘int atomic_read(const atomic_t*)’: /home/lizj/linux/tools/include/linux/compiler.h:157:45: error: use of deleted function ‘atomic_read(const atomic_t*)::<anonymous union>::<constructor>()’ ({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) ^ /home/lizj/linux/tools/include/asm/../../arch/x86/include/asm/atomic.h:28:9: note: in expansion of macro ‘READ_ONCE’ return READ_ONCE((v)->counter); ^ /home/lizj/linux/tools/include/linux/compiler.h:157:11: note: ‘atomic_read(const atomic_t*)::<anonymous union>::<constructor>()’ is implicitly deleted because the default definition would be ill-formed: ({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) ^ /home/lizj/linux/tools/include/asm/../../arch/x86/include/asm/atomic.h:28:9: note: in expansion of macro ‘READ_ONCE’ return READ_ONCE((v)->counter); ^ /home/lizj/linux/tools/include/linux/compiler.h:157:11: error: uninitialized const member in ‘union atomic_read(const atomic_t*)::<anonymous>’ ({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) ^ /home/lizj/linux/tools/include/asm/../../arch/x86/include/asm/atomic.h:28:9: note: in expansion of macro ‘READ_ONCE’ return READ_ONCE((v)->counter); ^ /home/lizj/linux/tools/include/linux/compiler.h:157:23: note: ‘const int atomic_read(const atomic_t*)::<anonymous union>::__val’ should be initialized ({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) ^ /home/lizj/linux/tools/include/asm/../../arch/x86/include/asm/atomic.h:28:9: note: in expansion of macro ‘READ_ONCE’ return READ_ONCE((v)->counter); ^ LD tests/perf-in.o ... --------------
Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com> --- tools/include/linux/compiler.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 07fd03c..d6675c5 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -86,6 +86,10 @@ #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) +#ifdef __cplusplus +#define READ_ONCE(x) (*(volatile typeof(x) *)&(x)) +#define WRITE_ONCE(x, val) (*(volatile typeof(x) *)&(x)) = (val) +#else #include <linux/types.h> /* @@ -160,6 +164,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s #define WRITE_ONCE(x, val) \ ({ union { typeof(x) __val; char __c[1]; } __u = { .__val = (val) }; __write_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) +#endif /* __cplusplus */ #ifndef __fallthrough # define __fallthrough -- 2.7.4