Deploy QT plugin with its own DLL depences - qt

Question

I have a QT application app.exe and a QT plugin plugin.dll. My plugin.dll depends on many other dynamic libraries (e.g. lib1.dll, lib2.dll and so on). To distribute my project I have this folder structure (ignoring QT libraries):
app.exe
plugins\
plugin.dll
lib1.dll
lib2.dll
lib3.dll
The problem is that there are too many dependences on libX.dll and I want to hide them in a plugin folder, e.g.:
app.exe
plugin\
plugin.dll
lib1.dll
lib2.dll
lib3.dll
But this way libraries libX.dll are "unseen" to my plugin, so that it cannot be loaded. Is there any way to solve this problem?
I am using this code to import libX.dll in plugin.dll's pro-file:
LIBS += -Lpath -l lib1 -l lib2 -l lib3

Answer 1

One of the ways of solving this problem is:
Link all libraries dynamically (at runtime)
Add extra location to search for the libraries
These changes should be done in plugin.dll code:
/* Declare a pointer to import function */
typedef void (*FUNCTION)();
FUNCTION f;
/* Make system search the DLLs in my plugin folder */
// Variable "app" contains directory of the application, not the plugin
QDir app = QDir(qApp->applicationDirPath());
// Combine path
QString plugin_path = app.filePath("plugins/");
// Adding full path for DLL search
SetDllDirectory(plugin_path.toStdWString().c_str());
/* Linking the library */
QLibrary mylib("mylib.dll");
f = (FUNCTION ) mylib.resolve("function");
if (f != NULL)
f(); // You got the function from DLL
else
return; // DLL could not be loaded
This solution has disadvanges:
It is not platform independent (I think you can avoid using SetDllDirectory in UNIX-like systems but I am not sure)
If you import a lot of functions you will have a lot of pointers
Does any one know pure Qt solution?