Re: [PATCH v2 3/8] accel/tcg/user-exec: silence the compiler warnings

[Thomas Huth]

On 30/10/2020 01.40, Chen Qun wrote:
> When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
> ../accel/tcg/user-exec.c: In function ‘handle_cpu_signal’:
> ../accel/tcg/user-exec.c:169:13: warning: this statement may fall through 
> [-Wimplicit-fallthrough=]
>   169 |             cpu_exit_tb_from_sighandler(cpu, old_set);
>       |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../accel/tcg/user-exec.c:172:9: note: here
>   172 |         default:
> 
> Mark the cpu_exit_tb_from_sighandler() function with QEMU_NORETURN to fix it.
> 
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
> ---
> v1->v2: Add QEMU_NORETURN to cpu_exit_tb_from_sighandler() function
> to avoid the compiler warnings(Base on Thomas's and Richard's comments).
> 
> Cc: Thomas Huth <thuth@redhat.com>
> Cc: Riku Voipio <riku.voipio@iki.fi>
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  accel/tcg/user-exec.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
> index 4ebe25461a..293ee86ea4 100644
> --- a/accel/tcg/user-exec.c
> +++ b/accel/tcg/user-exec.c
> @@ -49,7 +49,8 @@ __thread uintptr_t helper_retaddr;
>  /* exit the current TB from a signal handler. The host registers are
>     restored in a state compatible with the CPU emulator
>   */
> -static void cpu_exit_tb_from_sighandler(CPUState *cpu, sigset_t *old_set)
> +static void QEMU_NORETURN cpu_exit_tb_from_sighandler(CPUState *cpu,
> +                                                      sigset_t *old_set)
>  {
>      /* XXX: use siglongjmp ? */
>      sigprocmask(SIG_SETMASK, old_set, NULL);
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>