[cfe-dev] clang++: '-Wswitch-enum' turned on by default

[Alexandre Colucci]

That would be a nice improvement. I have some enums with more than 100 elements which cause a lot of warnings.

Alexandre

> 
> On Sep 16, 2010, at 9:12 AM, Chris Lattner wrote:
> 
>> 
>> On Sep 16, 2010, at 6:42 AM, Douglas Gregor wrote:
>> 
>>> 
>>> On Sep 16, 2010, at 3:30 AM, Alexandre Colucci wrote:
>>> 
>>>> Hey,
>>>> 
>>>> I noticed that clang++ seems to always use the option '-Wswitch-enum'. Shouldn't it be turned off by default?
>>> 
>>> No, it's an excellent warning to have on by default.
>>> 
>>>> Or is there a way to turn it off?
>>> 
>>> -Wno-switch-enum
>> 
>> I think that a more serious issue with the warning is that it can produce a *ton* of noise.  In a simple example:
>> 
>> enum x { a, b, c, d, e, f, g };
>> 
>> void foo(enum x a) {
>>   switch (a) {
>>   case b:
>>   case c: break;
>>   }
>> }
>> 
>> we produce:
>> 
>> t.c:4:11: warning: enumeration value 'a' not handled in switch [-Wswitch-enum]
>>   switch (a) {
>>           ^
>> t.c:4:11: warning: enumeration value 'd' not handled in switch [-Wswitch-enum]
>> t.c:4:11: warning: enumeration value 'e' not handled in switch [-Wswitch-enum]
>> t.c:4:11: warning: enumeration value 'f' not handled in switch [-Wswitch-enum]
>> t.c:4:11: warning: enumeration value 'g' not handled in switch [-Wswitch-enum]
>> 5 warnings generated.
>> 
>> In this case, I think it would be better to emit one warning say:
>> 
>> t.c:4:11: warning: 5 enumeration values not handled in switch: 'a', 'd', 'e' ... [-Wswitch-enum]
>> 
>> or something like that.  What do you think?
> 
> I think that's an excellent idea.
> 
> 	- Doug
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20100916/d230ac2c/attachment.html>