QPluginLoader not recognizing a plugin

[KShots]

So many things... :P But let's start with the most obvious one : unresolved symbols... When you build a shared library (and plugins are shared libraries) you must export some symbols... The thing, which already happened to me, is that when a method is declared but NOT defined within the plugin it can result in a "symbol lookup error" when QPluginLoader (through QLibrary actually) tries to load the plugin. This prevent the plugin instance to be created... To make sure this is not happening (or when it happens to locate the troublesome function) all you need is to create a simple test app with just a empty main() function and which LINKS to the plugin (it does not load it on run-time!!! it LINKS so you got to add the plugin to LIBS variable). This way all missing symbols should be notified when linking the test app and you'll see what to fix

Wow... you were right. The problems (there were a few missing symbols) were not anywhere in those sections, but in an entirely different area... and I would never have seen it without making that simple app. Thanks!

Heh, that's the way I really prefer to get answers - teach me to fish rather than give me a fish - now I can handle this sort of problem at any time. That's incredibly valuable .

[fullmetalcoder]

Wow... you were right. The problems (there were a few missing symbols) were not anywhere in those sections, but in an entirely different area... and I would never have seen it without making that simple app. Thanks!

I've been playing with plugins since about a year now and it took me a while to think about this trick so I thought it would be worth sharing it Good to see that it helped you.

Heh, that's the way I really prefer to get answers - teach me to fish rather than give me a fish - now I can handle this sort of problem at any time. That's incredibly valuable .

That's the point of a forum : sharing knowledge after having experienced several aspects of programming. We look like old soldiers sharing little tricks on how to survive on a battlefield