[v2] silence the compiler warnings

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

Posted by Chen Qun 5 years, 3 months ago

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);
-- 
2.27.0

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

Posted by Richard Henderson 5 years, 3 months ago

On 10/29/20 5:40 PM, 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).

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~

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

Posted by Philippe Mathieu-Daudé 5 years, 3 months ago

On 10/30/20 1:40 AM, 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).

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

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

Posted by Thomas Huth 5 years, 3 months ago

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>