[cfe-commits] [PATCH] PR9812: _Bool != bool

[Richard Smith]

Hi,

On Thu, June 16, 2011 14:00, Enea Zaffanella wrote:
> Il 14/06/2011 16:43, Douglas Gregor ha scritto:
>> On Jun 12, 2011, at 5:42 AM, Richard Smith wrote:
>>> The attached patch fixes PR9812 by splitting TST_bool into TST_bool
>>> (for
>>> C++ bool) and TST__Bool (for C99 _Bool). They both still translate
>>> into BuiltinType::Bool, but are now given the appropriate names in
>>> diagnostics.
>>
>> Cool, thanks!
>>
>>> One subtlety: BuiltinTypeLoc::getWrittenTypeSpec tries to convert
>>> backwards from a BuiltinType to a TypeSpecifierType. I've arbitrarily
>>> made this continue to produce TST_bool for BuiltinType::Bool, but this
>>> code is actually not currently reachable: the function is only called
>>> by the AST serialization code, and only in cases where the type cannot
>>> be bool.
>>
>> Weird, but okay.
>
> Sorry for this late answer, but I hadn't noticed this thread before.

Sorry for this late response!

> The goal of BuiltinTypeLoc is to provide quite accurate information
> about the syntax actually used in the sources and it is therefore
> essential to distinguish between TST__Bool and TST_bool.
>
> To this end, the thing to do is to change the implementation of
>
> bool needsExtraLocalData() const;
>
> so as to return true for BuiltinType::Bool.

I'm not so keen on this approach: it would inflate both the in-memory
representation of every bool type and increase the size of the serialized
AST. If we have no intention to begin supporting both bool and _Bool in
the same language, I'd prefer to pass LangOptions into
BuiltinTypeLoc::getWrittenTypeSpec and use that to reconstruct the correct
type, or find a spare bit somewhere.

Richard