[cfe-commits] [patch] PR10127/N3031 supporting decltype in nested-namespace-specifiers

[Douglas Gregor]

On Nov 14, 2011, at 8:10 AM, David Blaikie wrote:

>> Some comments follow…
> 
> Thanks for the feedback.
> 
>> Index: include/clang/Basic/TokenKinds.def
>> ===================================================================
>> --- include/clang/Basic/TokenKinds.def  (revision 143902)
>> +++ include/clang/Basic/TokenKinds.def  (working copy)
>> @@ -559,6 +559,8 @@
>>                          // function template specialization (not a type),
>>                          // e.g., "std::swap<int>"
>>  ANNOTATION(primary_expr) // annotation for a primary expression
>> +ANNOTATION(decltype)     // annotation for a decltype expression,
>> +                         // e.g., "decltype(foo.bar())"
>> 
>>  // Annotation for #pragma unused(...)
>>  // For each argument inside the parentheses the pragma handler will produce
>> 
>> Did you consider using annot_typename for this? I ask because annot_typename handles general types (including decltype), and is already well-supported throughout the parser. It looks like you've checked for annot_decltype in several places, but others (such as the tentative parser) would be confused by this annotation token.
> 
> No, I hadn't considered that - but at first blush I'd be concerned
> that this might end up being /too/ permissive, but I'll have a go
> mocking it up that way, it'll probably be tidier but I won't be sure
> what other scenarios might be accidentally accepted.


I can reply to the rest later, but just one quick comment here: using annot_typename would likely be too permissive in the parser, but of course Sema can make up for this by directly inspecting (e.g., via "isa") the actual spelling of the type. 

	- Doug