Messages in this thread | | | Subject | Re: [PATCH v2] tools include: define READ_ONCE/WRITE_ONCE for C++ | From | Li Zhijian <> | Date | Fri, 15 Dec 2017 09:20:37 +0800 |
| |
ping
On 11/30/2017 09:36 AM, Li Zhijian wrote: > 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 <lizhijian@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
-- Best regards. Li Zhijian (8528)
| |