Re: [PATCH 9/9] hw/timer/renesas_tmr: silence the compiler warnings

[Thomas Huth]

On 28/10/2020 10.59, 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:
>> ../hw/timer/renesas_tmr.c: In function ‘tmr_read’:
>> ../hw/timer/renesas_tmr.c:221:19: warning: this statement may fall through 
>> [-Wimplicit-fallthrough=]
>>   221 |         } else if (ch == 0) {i
>>       |                   ^
>> ../hw/timer/renesas_tmr.c:224:5: note: here
>>   224 |     case A_TCORB:
>>       |     ^~~~
>>
>> 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: Yoshinori Sato <ysato@users.sourceforge.jp>
>> Cc: Magnus Damm <magnus.damm@gmail.com>
>> ---
>>  hw/timer/renesas_tmr.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/hw/timer/renesas_tmr.c b/hw/timer/renesas_tmr.c
>> index 446f2eacdd..e03a8155b2 100644
>> --- a/hw/timer/renesas_tmr.c
>> +++ b/hw/timer/renesas_tmr.c
>> @@ -221,6 +221,7 @@ static uint64_t tmr_read(void *opaque, hwaddr addr, 
>> unsigned size)
>>          } else if (ch == 0) {
>>              return concat_reg(tmr->tcora);
>>          }
>> +        /* fall through */
>>      case A_TCORB:
>>          if (size == 1) {
>>              return tmr->tcorb[ch];
>>
> 
> You fixed A_TCORA but not A_TCORB...

A_TCORB cannot fall through, since it always does a "return" in both
branches of the if-statement.

However, it also looks really odd that A_TCORA falls through to A_TCORB here
and return that register value instead. Is this really intended? Yoshinori,
could you please double-check whether this is a bug here, or intended?

 Thanks,
  Thomas