Access Qt plugin classes from other plugins

[Joshua195]

Hi, I am loading a few shared object plugins using QPluginLoader from some subdirs:

myInterface.h
myPluginLoader.h

-pluginA/interfaceA.h
-pluginA/implemA.h

-pluginB/interfaceB.h
-pluginB/implemB.h

etc.

How do I get my pluginB to use classes from pluginA? I have no problem loading the plugins and calling their interface functions from myPluginLoader.h

In implemB.h, I have included ../pluginA/implemA.h and tried to initialize the implemA class, but I get "symbol lookup error" and "undefined symbol: _ZN6implemAC1ERKd"

I figure this is probably because I am linking pluginA to the base (myInterface/myPluginLoader etc.) but not linking pluginA to pluginB (and thus getting name mangling). I tried to export implemA using Q_DECL_EXPORT as:

class Q_DECL_EXPORT implemA
{ ... }

and

class Q_DECL_IMPORT implemB
{ ... }

as described here: QT Doc Creating Shared Libraries
but that gave me the same problem. Any idea how to resolve this?

Thank you!

[SGaist]

Hi and welome to devnet,

If you have several plugins using shared code then the most simple thing to do is move all the common code in a shared lib that you will link to all the plugins using them.

[Joshua195]

@SGaist Thanks for the response!

I assume the plugins would link to the shared code in the usual way (-Lshared/path -lsharedlib)?

Is having plugins with dependencies on one another generally considered bad practice?

[SGaist]

That assumption is corrected.

AFAIK, having linking dependencies between two plugins is not a clean design.