C++ RTTI/dynamic_cast across share module boundaries
C++ RTTI/dynamic_cast across share module boundaries
- Subject: C++ RTTI/dynamic_cast across share module boundaries
- From: Mads Paulin <email@hidden>
- Date: Tue, 19 Jan 2010 17:27:35 +0100
Hi,
I have hit what seems to be a very common problem when creating a plugin-based application utilizing the C++ dynamic_casting operator to down-cast a pointer in a dynamically loaded module.
As described in numerous places (e.g. here: http://lists.apple.com/archives/xcode-users/2006/Mar/msg00119.html) many other developers have experienced this since GCC compares type_info's by address instead of by comparing the name() strings, a pointer of class A in the main application does not dynamic_cast to a class A pointer in a loaded module.
I have been searching for a solution to this problem for a couple of days and tried out several proposed solutions but with no luck.
To sum up, this is what I've got:
1) A main application with a hierachy of C++ polymorphic classes. The application stores instances of these classes in a tree of base-class pointers.
2) A number of Controller/GUI plugins (NSBundles) each containing an Objective-C controller for a given main application polymorphics child class and a corresponding gui to set the properties of this represented object.
-Each controller object performs a dynamic_cast of the passed polymorphic baseclass pointer down to the object type that it can control. However due to the above problem, this dynamic_cast fails.
So - is there anyone on this list that has been able to successfuly use C++ RTTI across module boundaries and if so, what combination of xcode/GCC flags and dlopen tricks etc. was used ?
Kind regards,
Mads Paulin |
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Xcode-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden