Re: [dpdk-dev] [PATCH] eal: fix clang compilation error on ARM64

[Thomas Monjalon <thomas@monjalon.net>]

06/04/2018 20:25, Pavan Nikhilesh:
> On Fri, Apr 06, 2018 at 06:24:34PM +0200, Thomas Monjalon wrote:
> > 06/04/2018 13:01, Pavan Nikhilesh:
> > > Use __atomic_exchange_n instead of __atomic_exchange_(2/4/8).
> > >
> > > Fixes: ff2863570fcc ("eal: introduce atomic exchange operation")
> >
> > Please, could you provide a log of the error?
> 
>   CC eal.o
> In file included from /root/dpdk/lib/librte_eal/linuxapp/eal/eal.c:33:
> In file included from /root/dpdk/build/include/rte_eal_memconfig.h:13:
> In file included from /root/dpdk/build/include/rte_rwlock.h:10:
> In file included from /root/dpdk/build/include/generic/rte_rwlock.h:25:
> In file included from /root/dpdk/build/include/rte_atomic.h:37:
> In file included from /root/dpdk/build/include/rte_atomic_64.h:16:
> /root/dpdk/build/include/generic/rte_atomic.h:215:9: error: implicit declaration of function '__atomic_exchange_2' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
>         return __atomic_exchange_2(dst, val, __ATOMIC_SEQ_CST);
>                ^
> /root/dpdk/build/include/generic/rte_atomic.h:215:9: error: this function declaration is not a prototype [-Werror,-Wstrict-prototypes]
> /root/dpdk/build/include/generic/rte_atomic.h:494:9: error: implicit declaration of function '__atomic_exchange_4' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
>         return __atomic_exchange_4(dst, val, __ATOMIC_SEQ_CST);
>                ^
> /root/dpdk/build/include/generic/rte_atomic.h:494:9: error: this function declaration is not a prototype [-Werror,-Wstrict-prototypes]
> /root/dpdk/build/include/generic/rte_atomic.h:772:9: error: implicit declaration of function '__atomic_exchange_8' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
>         return __atomic_exchange_8(dst, val, __ATOMIC_SEQ_CST);
>                ^
> /root/dpdk/build/include/generic/rte_atomic.h:772:9: error: this function declaration is not a prototype [-Werror,-Wstrict-prototypes]
> 6 errors generated.
> make[5]: *** [/root/dpdk/mk/internal/rte.compile-pre.mk:116: eal.o] Error 1
> 
> 
> >
> > Why __atomic_exchange_n is fixing the compilation?
> 
> I guess __atomic_exchange_2/5/8 fall under c++11 standard?
> https://llvm.org/docs/Atomics.html

Applied (with error log), thanks