[cmake-developers] When should a library be in LINK_INTERFACE_LIBRARIES?

[Stephen Kelly]

Hi there,

I'm trying to get the IMPORTED_LINK_INTERFACE_LIBRARIES for Qt modules 
correct.

There is a debate over the QtQml module at the moment. It has in one of its 
interface classes (QQmlEngine) a method QNetworkAccessManager 
*networkAccessManager() const, and the QNetworkAccessManager class is 
forward declared.

https://qt.gitorious.org/qt/qtdeclarative/blobs/master/src/qml/qml/qqmlengine.h

The QNetworkAccessManager class is in the QtNetwork module. 

One can use the QQmlEngine class without linking to QtNetwork. It would only 
be necessary to link to QtNetwork if the networkAccessManager() method is 
called. Otherwise, it is overlinking.

So I'm looking for other opinions. Should the LINK_INTERFACE_LIBRARIES 
contain all dependencies that could possibly be needed, or just the minimum 
(if you don't use these libraries, you code won't work at all)?

Thanks,

Steve.