Re: [PATCH 33/35] perf bench futex: Fix build on musl + clang

[Jörg Krause]

Hi Arnaldo,

On Mon, 2017-03-06 at 16:38 -0300, Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> 
> When building with clang on a musl libc system, Alpine Linux, we end up
> hitting a problem where memset() is used but its prototype is not
> present, add it to avoid this:
> 
>   bench/futex-wake.c:99:3: error: implicitly declaring library function 'memset' with type 'void *(void *, int, unsigned long)'
>         [-Werror,-Wimplicit-function-declaration]
>                   CPU_ZERO(&cpu);
>                   ^
>   /usr/include/sched.h:127:23: note: expanded from macro 'CPU_ZERO'
>   #define CPU_ZERO(set) CPU_ZERO_S(sizeof(cpu_set_t),set)
>                         ^
>   /usr/include/sched.h:110:30: note: expanded from macro 'CPU_ZERO_S'
>   #define CPU_ZERO_S(size,set) memset(set,0,size)
>                                ^
>   bench/futex-wake.c:99:3: note: include the header <string.h> or explicitly provide a declaration for 'memset'

In my opinion the musl <shed.h> header file should include <string.h>.
I've reported the issue to the musl mailing list:

http://www.openwall.com/lists/musl/2017/09/08/1

> Found while updating my test build containers to build perf with clang in more
> systems.
> 
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Wang Nan <wangnan0@xxxxxxxxxx>
> Link: http://lkml.kernel.org/n/tip-jh10vaz2r98zl6gm5iau8prr@xxxxxxxxxxxxxx
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> ---
>  tools/perf/bench/futex-hash.c          | 1 +
>  tools/perf/bench/futex-lock-pi.c       | 1 +
>  tools/perf/bench/futex-requeue.c       | 1 +
>  tools/perf/bench/futex-wake-parallel.c | 1 +
>  tools/perf/bench/futex-wake.c          | 1 +
>  5 files changed, 5 insertions(+)
> 
> diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
> index da04b8c5568a..2499e1b0c6fb 100644
> --- a/tools/perf/bench/futex-hash.c
> +++ b/tools/perf/bench/futex-hash.c
> @@ -9,6 +9,7 @@
>   */
>  
>  /* For the CLR_() macros */
> +#include <string.h>
>  #include <pthread.h>
>  
>  #include <errno.h>
> diff --git a/tools/perf/bench/futex-lock-pi.c b/tools/perf/bench/futex-lock-pi.c
> index 91877777ec6e..a20814d94af1 100644
> --- a/tools/perf/bench/futex-lock-pi.c
> +++ b/tools/perf/bench/futex-lock-pi.c
> @@ -3,6 +3,7 @@
>   */
>  
>  /* For the CLR_() macros */
> +#include <string.h>
>  #include <pthread.h>
>  
>  #include <signal.h>
> diff --git a/tools/perf/bench/futex-requeue.c b/tools/perf/bench/futex-requeue.c
> index 2b9705a8734c..9fad1e4fcd3e 100644
> --- a/tools/perf/bench/futex-requeue.c
> +++ b/tools/perf/bench/futex-requeue.c
> @@ -9,6 +9,7 @@
>   */
>  
>  /* For the CLR_() macros */
> +#include <string.h>
>  #include <pthread.h>
>  
>  #include <signal.h>
> diff --git a/tools/perf/bench/futex-wake-parallel.c b/tools/perf/bench/futex-wake-parallel.c
> index 2c8fa67ad537..40f5fcf1d120 100644
> --- a/tools/perf/bench/futex-wake-parallel.c
> +++ b/tools/perf/bench/futex-wake-parallel.c
> @@ -8,6 +8,7 @@
>   */
>  
>  /* For the CLR_() macros */
> +#include <string.h>
>  #include <pthread.h>
>  
>  #include <signal.h>
> diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
> index e246b1b8388a..789490281ae3 100644
> --- a/tools/perf/bench/futex-wake.c
> +++ b/tools/perf/bench/futex-wake.c
> @@ -9,6 +9,7 @@
>   */
>  
>  /* For the CLR_() macros */
> +#include <string.h>
>  #include <pthread.h>
>  
>  #include <signal.h>

Best regards,
JÃrg Krause