Compiler patch for runtime reflection

[Timon Gehr]

On 10/23/2011 12:19 PM, Vladimir Panteleev wrote:
> On Sun, 23 Oct 2011 01:54:52 +0300, Alex Rønne Petersen
> <xtzgzorex at gmail.com> wrote:
>
>> On 22-10-2011 17:18, Vladimir Panteleev wrote:
>>> On Sat, 22 Oct 2011 16:35:57 +0300, Alex Rønne Petersen
>>> <xtzgzorex at gmail.com> wrote:
>>>
>>>> On 22-10-2011 15:20, Andrej Mitrovic wrote:
>>>>> On 10/22/11, Vladimir Panteleev<vladimir at thecybershadow.net> wrote:
>>>>>> On Sat, 22 Oct 2011 13:50:32 +0300, Alex Rønne Petersen
>>>>>> <xtzgzorex at gmail.com> wrote:
>>>>>>
>>>>>>> You could just introduce a -reflection switch to include reflection
>>>>>>> information.
>>>>>>
>>>>>> As I mentioned in the previous thread on the subject, I think that
>>>>>> ideally
>>>>>> we should improve compile-time reflection so it's possible to
>>>>>> generate
>>>>>> runtime reflection information at compilation time. Something like
>>>>>> this:
>>>>>>
>>>>>> import reflection;
>>>>>>
>>>>>> enum reflectionForStdStdio =
>>>>>> generateReflectionForModule("std.stdio");
>>>>>>
>>>>>> void main()
>>>>>> {
>>>>>> reflectionForStdStdio.callFunction("writeln", "Hello, world!");
>>>>>> }
>>>>>>
>>>>>> --
>>>>>> Best regards,
>>>>>> Vladimir mailto:vladimir at thecybershadow.net
>>>>>>
>>>>>
>>>>> I think user properties would be a perfect fit for this. :)
>>>>>
>>>>> @reflected
>>>>> struct Foo {}
>>>>
>>>> The only downside with either approach
>>>
>>> What do you mean by "either approach"? Which is the other one?
>>>
>>
>> @reflected and generateReflectionForModule.
>>
>> - Alex
>
> I don't see how my generateReflectionForModule idea requires any
> modification of the reflected code. The module can generate RTTI for all
> types used recursively from the starting point. If more precision is
> needed, it can be specified as generateReflectionForModule/etc. parameters.
>

The module can generate RTTI for all types recursively from the starting 
point iff that information is statically available. It does not have to 
be. A module that comes as .di + static library binary could return a 
reference to a private class that has a publicly exported base class. 
How would you generate RTTI for a statically invisible class?

Eg:

// file A.d
module A;
class C{int x; ...}
private class D: C{int y; ...}

C factory(){ return new D; }


// file A.di
module A;
class C{int x; ...}

// file B.d
import A; // imports A.di file

enum reflectionForA = generateReflectionForModule("A");

void main(){
     C c = factory();
     auto s = reflectionForA.serialize(c); // disaster strikes.
}