Module variables▲
Qt modules loaded with find_package set various variables.
You rarely need to access these variables directly. Common tasks like linking against a module should be done through the library targets each module defines.
For example, find_package(Qt5 COMPONENTS Widgets), when successful, makes the following variables available:
|
Variable |
Description |
|---|---|
|
Qt5Widgets_COMPILE_DEFINITIONS |
A list of compile definitions to use when building against the library. |
|
Qt5Widgets_DEFINITIONS |
A list of definitions to use when building against the library. |
|
Qt5Widgets_EXECUTABLE_COMPILE_FLAGS |
A string of flags to use when building executables against the library. |
|
Qt5Widgets_FOUND |
A boolean that describes whether the module was found successfully. |
|
Qt5Widgets_INCLUDE_DIRS |
A list of include directories to use when building against the library. |
|
Qt5Widgets_LIBRARIES |
The name of the imported target for the module: Qt5::Widgets |
|
Qt5Widgets_PRIVATE_INCLUDE_DIRS |
A list of private include directories to use when building against the library and using private Qt API. |
|
Qt5Widgets_VERSION_STRING |
A string containing the module's version. |
For all packages found with find_package, equivalents of these variables are available; they are case-sensitive.
Installation variables▲
Additionally, there are also variables that don't relate to a particular package, but to the Qt installation itself.
|
Variable |
Description |
|---|---|
|
QT_DEFAULT_MAJOR_VERSION |
An integer that controls the Qt version that qt_ commands forward to in case of mixed Qt 5 and Qt 6 projects. It needs to be set to either 5 or 6 before the respective find_package() calls. If set to 5, commands starting with qt_ will call their counterpart starting with qt5_. If set to 6, they will call their counterpart starting with qt6_. If not set, the first find_package call defines the default version. This functionality was added in Qt 5.15. |
|
QT_LIBINFIX |
A string that holds the infix used in library names, when Qt is configured with -libinfix. |
|
QT_NO_CREATE_VERSIONLESS_FUNCTIONS |
Since Qt 5.15, modules define not only commands that start with qt5_, but also ones with qt_. You can set QT_NO_CREATE_VERSIONLESS_FUNCTIONS before find_package to prevent this. |
|
QT_NO_CREATE_VERSIONLESS_TARGETS |
Since Qt 5.15, modules define not only targets that start with Qt5::, but also ones with Qt::. You can set QT_NO_CREATE_VERSIONLESS_TARGETS before find_package to prevent this. |
|
QT_VISIBILITY_AVAILABLE |
On Unix, a boolean that describes whether Qt libraries and plugins were compiled with -fvisibility=hidden. This means that only selected symbols are exported. |