Re: [Qemu-devel] [PATCH 2/3] spapr: Fix compiler warning for some versions of gcc (h_remove)

[Paolo Bonzini <pbonzini@redhat.com>]

Il 24/06/2013 22:35, Stefan Weil ha scritto:
> Am 24.06.2013 22:27, schrieb Paolo Bonzini:
>> Il 24/06/2013 19:48, Stefan Weil ha scritto:
>>> i686-w64-mingw32-gcc (GCC) 4.6.3 from Debian wheezy reports this warning:
>>>
>>> hw/ppc/spapr_hcall.c:188:1: warning:
>>>  control reaches end of non-void function [-Wreturn-type]
>>>
>>> Replacing the 4th case REMOVE_HW (which is currently unused) by the default
>>> case fixes this warning.
>>>
>>> The assertion is dead code because all possible cases are handled in the
>>> switch statements, so remove it. This avoids future warnings from static
>>> code analyzers.
>>>
>>> Signed-off-by: Stefan Weil <sw@weilnetz.de>
>>> ---
>>>  hw/ppc/spapr_hcall.c |    4 +---
>>>  1 file changed, 1 insertion(+), 3 deletions(-)
>>>
>>> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
>>> index 00f21f5..d49ce53 100644
>>> --- a/hw/ppc/spapr_hcall.c
>>> +++ b/hw/ppc/spapr_hcall.c
>>> @@ -180,11 +180,9 @@ static target_ulong h_remove(PowerPCCPU *cpu, sPAPREnvironment *spapr,
>>>      case REMOVE_PARM:
>>>          return H_PARAMETER;
>>>  
>>> -    case REMOVE_HW:
>>> +    default: /* REMOVE_HW */
>>>          return H_HARDWARE;
>>>      }
>>> -
>>> -    assert(0);
>>>  }
>>>  
>>>  #define H_BULK_REMOVE_TYPE             0xc000000000000000ULL
>>>
>> Does s/assert(0)/abort()/ fix the warning too?  That's clearer.
> 
> Yes, that also fixes this warning. A better compiler or a static
> code checker might then complain about dead code because all
> possible cases are handled in the switch statement.

We'll get there when we see it... and such a compiler can well learn to
ignore a dead abort().

Paolo