[cfe-dev] -Wcatch-incomplete-type-extensions

[Douglas Gregor]

On Jan 19, 2012, at 10:44 AM, Howard Hinnant wrote:

> 
> On Jan 19, 2012, at 1:40 PM, John McCall wrote:
> 
>> On Jan 19, 2012, at 10:25 AM, Howard Hinnant wrote:
>>> On Jan 19, 2012, at 12:39 PM, John McCall wrote:
>>>>> I'm willing to file a bug on this, but I wanted to get guidance here first.
>>>> 
>>>> That is absolutely a bug that we should fix.
>>> 
>>> http://llvm.org/bugs/show_bug.cgi?id=11803
>>> 
>>>>> g++-4.2 refuses to compile the code that malfunctions, and thus never gets into this situation.
>>>> 
>>>> Because it catches a reference to incomplete type?  Rejecting this is not allowed.
>>> 
>>> The compiler is required to issue a diagnostic because the code is ill-formed (clang does issue a warning):
>>> 
>>> 15.3 [except.handle]/p1:
>>> 
>>>> The exception-declaration in a handler describes the type(s) of exceptions that can cause that handler to be entered. The exception-declaration shall not denote an incomplete type, an abstract class type, or an rvalue reference type. The exception-declaration shall not denote a pointer or reference to an incomplete type, other than void*, const void*, volatile void*, or const volatile void*.
>> 
>> Okay.  I don't know off-hand why we accept this, then, particularly if GCC does not.
> 
> It is because of http://llvm.org/bugs/show_bug.cgi?id=6527
> 
> I tried to collect all this information in the bug report (http://llvm.org/bugs/show_bug.cgi?id=11803) so it is there in one place.  And at this point I'm not sure what the best solution is.  But I'm pretty sure we're in an anywhere-but-here situation.

Agreed. I've made the warning into an error in Clang r148838.

	- Doug