Its DLL is located here:

@MY_PROJECT_ROOT/../Release/obj/imageformats/qjpeg4.dll@

I get this linker error:

@Linking CXX executable test.exe
CMakeFiles\test.dir/objects.a(entrypoint.cpp.obj):entrypoint.cpp:(.text.startup+0x2692): undefined reference to `qt_plugin_instance_qjpeg()'
collect2: ld returned 1 exit status
@

In the file containing main() I have: @Q_IMPORT_PLUGIN(qjpeg)@

I tried adding these lines, with no improvement:

@QApplication app(argc, argv);
QString sDir = QCoreApplication::applicationDirPath();
app.addLibraryPath(sDir + "/plugins");@

The previous error should even not depend on the fact that the DLL has not been found, since it is still in the link phase...

If in the file containing main() I remove Q_IMPORT_PLUGIN(qjpeg), the linker is successful, but the executable does absolutely nothing.

The only Qt headers I include are <QApplication> and <QtPlugin>; adding <QtGui> has been useless.

I am using cmake, and this is the token of my CMakeLists.txt file relative to Qt:

@find_package(Qt4 REQUIRED)
include(${QT_USE_FILE})
add_definitions(${QT_DEFINITIONS})
set(useQt_HEADERS )
set(useQt_SOURCES entrypoint.cpp source.cpp)
QT4_WRAP_CPP(useQt_HEADERS_MOC ${useQt_HEADERS})
...
target_link_libraries(myProject ${QT_LIBRARIES} )
@