diff mbox series

[8/9] target/ppc: silence the compiler warnings

Message ID 20201028041819.2169003-9-kuhn.chenqun@huawei.com
State New
Headers show
Series silence the compiler warnings | expand

Commit Message

Chenqun (kuhn) Oct. 28, 2020, 4:18 a.m. UTC
When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
target/ppc/mmu_helper.c: In function ‘dump_mmu’:
target/ppc/mmu_helper.c:1351:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
 1351 |         if (ppc64_v3_radix(env_archcpu(env))) {
      |            ^
target/ppc/mmu_helper.c:1358:5: note: here
 1358 |     default:
      |     ^~~~~~~

Add the corresponding "fall through" comment to fix it.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
---
Cc: David Gibson <david@gibson.dropbear.id.au>
---
 target/ppc/mmu_helper.c | 1 +
 1 file changed, 1 insertion(+)

Comments

David Gibson Oct. 28, 2020, 4:30 a.m. UTC | #1
On Wed, Oct 28, 2020 at 12:18:18PM +0800, Chen Qun wrote:
> When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
> target/ppc/mmu_helper.c: In function ‘dump_mmu’:
> target/ppc/mmu_helper.c:1351:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
>  1351 |         if (ppc64_v3_radix(env_archcpu(env))) {
>       |            ^
> target/ppc/mmu_helper.c:1358:5: note: here
>  1358 |     default:
>       |     ^~~~~~~
> 
> Add the corresponding "fall through" comment to fix it.
> 
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>

Acked-by: David Gibson <david@gibson.dropbear.id.au>

> ---
> Cc: David Gibson <david@gibson.dropbear.id.au>
> ---
>  target/ppc/mmu_helper.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c
> index 8972714775..51749b62df 100644
> --- a/target/ppc/mmu_helper.c
> +++ b/target/ppc/mmu_helper.c
> @@ -1355,6 +1355,7 @@ void dump_mmu(CPUPPCState *env)
>              break;
>          }
>  #endif
> +        /* fall through */
>      default:
>          qemu_log_mask(LOG_UNIMP, "%s: unimplemented\n", __func__);
>      }
Philippe Mathieu-Daudé Oct. 28, 2020, 9:56 a.m. UTC | #2
On 10/28/20 5:18 AM, Chen Qun wrote:
> When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
> target/ppc/mmu_helper.c: In function ‘dump_mmu’:
> target/ppc/mmu_helper.c:1351:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
>  1351 |         if (ppc64_v3_radix(env_archcpu(env))) {
>       |            ^
> target/ppc/mmu_helper.c:1358:5: note: here
>  1358 |     default:
>       |     ^~~~~~~
> 
> Add the corresponding "fall through" comment to fix it.
> 
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
> ---
> Cc: David Gibson <david@gibson.dropbear.id.au>
> ---
>  target/ppc/mmu_helper.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c
> index 8972714775..51749b62df 100644
> --- a/target/ppc/mmu_helper.c
> +++ b/target/ppc/mmu_helper.c
> @@ -1355,6 +1355,7 @@ void dump_mmu(CPUPPCState *env)
>              break;
>          }
>  #endif
> +        /* fall through */

I'm surprise the compiler emit a warning for missing comment,
but don't emit one for superfluous and confusing ones (when
building a ppc32-only target). You'd need to put this before
the #endif.

But instead of this band-aid to silent warning, replace the
TODO by a LOG_UNIMP call, and add a break before the #endif.

>      default:
>          qemu_log_mask(LOG_UNIMP, "%s: unimplemented\n", __func__);
>      }
>
Thomas Huth Oct. 28, 2020, 3:06 p.m. UTC | #3
On 28/10/2020 10.56, Philippe Mathieu-Daudé wrote:
> On 10/28/20 5:18 AM, Chen Qun wrote:
>> When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
>> target/ppc/mmu_helper.c: In function ‘dump_mmu’:
>> target/ppc/mmu_helper.c:1351:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>  1351 |         if (ppc64_v3_radix(env_archcpu(env))) {
>>       |            ^
>> target/ppc/mmu_helper.c:1358:5: note: here
>>  1358 |     default:
>>       |     ^~~~~~~
>>
>> Add the corresponding "fall through" comment to fix it.
>>
>> Reported-by: Euler Robot <euler.robot@huawei.com>
>> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
>> ---
>> Cc: David Gibson <david@gibson.dropbear.id.au>
>> ---
>>  target/ppc/mmu_helper.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c
>> index 8972714775..51749b62df 100644
>> --- a/target/ppc/mmu_helper.c
>> +++ b/target/ppc/mmu_helper.c
>> @@ -1355,6 +1355,7 @@ void dump_mmu(CPUPPCState *env)
>>              break;
>>          }
>>  #endif
>> +        /* fall through */
> 
> I'm surprise the compiler emit a warning for missing comment,
> but don't emit one for superfluous and confusing ones (when
> building a ppc32-only target). You'd need to put this before
> the #endif.
> 
> But instead of this band-aid to silent warning, replace the
> TODO by a LOG_UNIMP call, and add a break before the #endif.

+1 for replacing the TODO with a LOG_UNIMP call and adding a break instead,
that would look way less messy than the current code.

 Thanks,
  Thomas
David Gibson Oct. 28, 2020, 11:39 p.m. UTC | #4
On Wed, Oct 28, 2020 at 04:06:03PM +0100, Thomas Huth wrote:
> On 28/10/2020 10.56, Philippe Mathieu-Daudé wrote:
> > On 10/28/20 5:18 AM, Chen Qun wrote:
> >> When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
> >> target/ppc/mmu_helper.c: In function ‘dump_mmu’:
> >> target/ppc/mmu_helper.c:1351:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
> >>  1351 |         if (ppc64_v3_radix(env_archcpu(env))) {
> >>       |            ^
> >> target/ppc/mmu_helper.c:1358:5: note: here
> >>  1358 |     default:
> >>       |     ^~~~~~~
> >>
> >> Add the corresponding "fall through" comment to fix it.
> >>
> >> Reported-by: Euler Robot <euler.robot@huawei.com>
> >> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
> >> ---
> >> Cc: David Gibson <david@gibson.dropbear.id.au>
> >> ---
> >>  target/ppc/mmu_helper.c | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c
> >> index 8972714775..51749b62df 100644
> >> --- a/target/ppc/mmu_helper.c
> >> +++ b/target/ppc/mmu_helper.c
> >> @@ -1355,6 +1355,7 @@ void dump_mmu(CPUPPCState *env)
> >>              break;
> >>          }
> >>  #endif
> >> +        /* fall through */
> > 
> > I'm surprise the compiler emit a warning for missing comment,
> > but don't emit one for superfluous and confusing ones (when
> > building a ppc32-only target). You'd need to put this before
> > the #endif.
> > 
> > But instead of this band-aid to silent warning, replace the
> > TODO by a LOG_UNIMP call, and add a break before the #endif.
> 
> +1 for replacing the TODO with a LOG_UNIMP call and adding a break instead,
> that would look way less messy than the current code.

True, that would be a better approach.
Chenqun (kuhn) Oct. 29, 2020, 7:16 a.m. UTC | #5
> -----Original Message-----
> From: David Gibson [mailto:david@gibson.dropbear.id.au]
> Sent: Thursday, October 29, 2020 7:39 AM
> To: Thomas Huth <thuth@redhat.com>
> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>; Chenqun (kuhn)
> <kuhn.chenqun@huawei.com>; qemu-devel@nongnu.org;
> qemu-trivial@nongnu.org; Euler Robot <euler.robot@huawei.com>;
> Zhanghailiang <zhang.zhanghailiang@huawei.com>; ganqixin
> <ganqixin@huawei.com>
> Subject: Re: [PATCH 8/9] target/ppc: silence the compiler warnings
> 
> On Wed, Oct 28, 2020 at 04:06:03PM +0100, Thomas Huth wrote:
> > On 28/10/2020 10.56, Philippe Mathieu-Daudé wrote:
> > > On 10/28/20 5:18 AM, Chen Qun wrote:
> > >> When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed
> warning:
> > >> target/ppc/mmu_helper.c: In function ‘dump_mmu’:
> > >> target/ppc/mmu_helper.c:1351:12: warning: this statement may fall
> through [-Wimplicit-fallthrough=]
> > >>  1351 |         if (ppc64_v3_radix(env_archcpu(env))) {
> > >>       |            ^
> > >> target/ppc/mmu_helper.c:1358:5: note: here
> > >>  1358 |     default:
> > >>       |     ^~~~~~~
> > >>
> > >> Add the corresponding "fall through" comment to fix it.
> > >>
> > >> Reported-by: Euler Robot <euler.robot@huawei.com>
> > >> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
> > >> ---
> > >> Cc: David Gibson <david@gibson.dropbear.id.au>
> > >> ---
> > >>  target/ppc/mmu_helper.c | 1 +
> > >>  1 file changed, 1 insertion(+)
> > >>
> > >> diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c
> > >> index 8972714775..51749b62df 100644
> > >> --- a/target/ppc/mmu_helper.c
> > >> +++ b/target/ppc/mmu_helper.c
> > >> @@ -1355,6 +1355,7 @@ void dump_mmu(CPUPPCState *env)
> > >>              break;
> > >>          }
> > >>  #endif
> > >> +        /* fall through */
> > >
> > > I'm surprise the compiler emit a warning for missing comment, but
> > > don't emit one for superfluous and confusing ones (when building a
> > > ppc32-only target). You'd need to put this before the #endif.
> > >
> > > But instead of this band-aid to silent warning, replace the TODO by
> > > a LOG_UNIMP call, and add a break before the #endif.
> >
> > +1 for replacing the TODO with a LOG_UNIMP call and adding a break
> > +instead,
> > that would look way less messy than the current code.
> 
> True, that would be a better approach.

Yeah, that's a good idea.  
I'll modify it in the v2.

Thanks,
Chen Qun
> 
> --
> David Gibson			| I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_
> _other_
> 				| _way_ _around_!
> http://www.ozlabs.org/~dgibson
diff mbox series

Patch

diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c
index 8972714775..51749b62df 100644
--- a/target/ppc/mmu_helper.c
+++ b/target/ppc/mmu_helper.c
@@ -1355,6 +1355,7 @@  void dump_mmu(CPUPPCState *env)
             break;
         }
 #endif
+        /* fall through */
     default:
         qemu_log_mask(LOG_UNIMP, "%s: unimplemented\n", __func__);
     }