[cfe-commits] r150055 - in /cfe/trunk: include/clang/Basic/DiagnosticGroups.td include/clang/Basic/DiagnosticSemaKinds.td test/Sema/switch.c

[Nico Weber]

On Wed, Feb 8, 2012 at 12:24 PM, Ted Kremenek <kremenek at apple.com> wrote:
> Out of curiosity, how did this trigger for you?  Would you object to this being under -Wall?

It fired all over the place in the chromium codebase and its
dependencies. I just turned it off, so I can live with it being in
-Wall. But one thing I really like about clang is its sense for good
defaults in warnings. This warning feels like it's fairly noisy on
existing code, and fixing it would be done mostly to appease the
warning – in my experience, enum-switching code usually isn't terribly
buggy. (I've been meaning to look at the recent switch changes and
warnings and send a mail about them, but I didn't get to that yet. I
feel like moving this warning out of -Wall and moving -Wswitch from
-Wmost to -Wall is the right thing to do, but I haven't looked to
closely yet.)

Maybe that's just change aversion, though :-)

Nico

>
> On Feb 7, 2012, at 9:18 PM, Nico Weber wrote:
>
>> +1, thanks for this!
>>
>> On Tue, Feb 7, 2012 at 9:08 PM, Ted Kremenek <kremenek at apple.com> wrote:
>>> Author: kremenek
>>> Date: Tue Feb  7 23:08:58 2012
>>> New Revision: 150055
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=150055&view=rev
>>> Log:
>>> Move -Wcovered-switch-default out of -Wswitch (and -Wall), and make it an opt-in warning.
>>>
>>> This is a great warning, but it was observed that a ton of real world code violates
>>> it all the time for (semi-)legitimate reasons.  This warnings is fairly pedantic, which is good,
>>> but not for everyone.  For example, there is a fair amount of idiomatic code out there
>>> that does "default: abort()", and similar idioms.
>>>
>>> Addresses <rdar://problem/10814651>.
>>>
>>> Modified:
>>>    cfe/trunk/include/clang/Basic/DiagnosticGroups.td
>>>    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>>    cfe/trunk/test/Sema/switch.c
>>>
>>> Modified: cfe/trunk/include/clang/Basic/DiagnosticGroups.td
>>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticGroups.td?rev=150055&r1=150054&r2=150055&view=diff
>>> ==============================================================================
>>> --- cfe/trunk/include/clang/Basic/DiagnosticGroups.td (original)
>>> +++ cfe/trunk/include/clang/Basic/DiagnosticGroups.td Tue Feb  7 23:08:58 2012
>>> @@ -184,9 +184,9 @@
>>>  def : DiagGroup<"strict-prototypes">;
>>>  def StrictSelector : DiagGroup<"strict-selector-match">;
>>>  def MethodDuplicate : DiagGroup<"duplicate-method-match">;
>>> -def SwitchEnum     : DiagGroup<"switch-enum">;
>>>  def CoveredSwitchDefault : DiagGroup<"covered-switch-default">;
>>> -def Switch         : DiagGroup<"switch", [CoveredSwitchDefault]>;
>>> +def SwitchEnum     : DiagGroup<"switch-enum">;
>>> +def Switch         : DiagGroup<"switch">;
>>>  def Trigraphs      : DiagGroup<"trigraphs">;
>>>
>>>  def : DiagGroup<"type-limits">;
>>>
>>> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=150055&r1=150054&r2=150055&view=diff
>>> ==============================================================================
>>> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
>>> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Feb  7 23:08:58 2012
>>> @@ -5064,7 +5064,7 @@
>>>
>>>  def warn_unreachable_default : Warning<
>>>   "default label in switch which covers all enumeration values">,
>>> -  InGroup<CoveredSwitchDefault>;
>>> +  InGroup<CoveredSwitchDefault>, DefaultIgnore;
>>>  def warn_not_in_enum : Warning<"case value not in enumerated type %0">,
>>>   InGroup<Switch>;
>>>  def err_typecheck_statement_requires_scalar : Error<
>>>
>>> Modified: cfe/trunk/test/Sema/switch.c
>>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/switch.c?rev=150055&r1=150054&r2=150055&view=diff
>>> ==============================================================================
>>> --- cfe/trunk/test/Sema/switch.c (original)
>>> +++ cfe/trunk/test/Sema/switch.c Tue Feb  7 23:08:58 2012
>>> @@ -1,4 +1,4 @@
>>> -// RUN: %clang_cc1 -fsyntax-only -verify -Wswitch-enum %s
>>> +// RUN: %clang_cc1 -fsyntax-only -verify -Wswitch-enum -Wcovered-switch-default %s
>>>  void f (int z) {
>>>   while (z) {
>>>     default: z--;            // expected-error {{statement not in switch}}
>>>
>>>
>>> _______________________________________________
>>> cfe-commits mailing list
>>> cfe-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>