[cfe-commits] Fix PR13434 - mangling of templates with function pointers as arguments

[John McCall]

On Jul 31, 2012, at 4:32 AM, Timur Iskhodzhanov wrote:
> On Tue, Jul 31, 2012 at 4:56 AM, John McCall <rjmccall at apple.com> wrote:
>> On Jul 27, 2012, at 7:30 AM, Timur Iskhodzhanov wrote:
>>> Attached is an updated patch which has slightly uglier code (due to
>>> code duplication) but better mangling.
>>> The "eta" mangling remains the same, "_E$$A6" has been replaced with
>>> "_E" everywhere.
>> 
>> +  QualType pointee = T->getPointeeType();
>> +  assert(isa<FunctionProtoType>(pointee));
>> +  mangleType(static_cast<const FunctionProtoType*>(pointee.getTypePtr()), NULL, false, false);
>> 
>> The easier way to do an assert-and-cast is like this:
>>  cast<FunctionProtoType>(pointee)
>> 
>> However, you can't actually do a cast here, because there could be a typedef in the way.  Test case:
>>  typedef void fn();
>>  void foo(fn^ block) { block(); }
>> 
>> So instead you need to do this:
>>  pointee->castAs<FunctionProtoType>()
>> This is like getAs<>, but asserting.
> Thanks for the tip!
> See the updated patch.

I turned a few extra getAs<> calls into castAs<> and committed as r162638.

> FTR, the idea of using static_cast came to me after looking at
> MicrosoftMangle:972.
> Probably, static_cast should be replaced with getAs/castAs there too ?

If it's working on a canonical type, static_cast is fine, although we generally
prefer cast<> in such cases.  If it's not a canonical type, it should be castAs.

John.