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CMake Variable Reference

Module variables

Qt modules loaded with find_package set various variables.

Note: 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.

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