Qt Configure Options | Qt 5.12 5.12.4

Qt 5.12 | Qt Configure Options

Qt 5.12.4 Reference Documentation

# Qt Configure Options

`configure` is a command-line tool which determines how to build Qt for a particular platform. Configure can exclude a feature in Qt as well as determine how Qt builds and deploys applications onto host platforms. This page discusses some of the configure options, but for the full list of options, enter the command `configure -h`. Configure should be run from the main Qt source directory.

Unless stated otherwise, the commands in this page are for the Linux platforms. On macOS and on Windows, the `PATH` and directory structure are different, therefore the commands will vary. Also, on Windows systems, the configure script is called configure.bat.

After running `configure`, build the sources with the `make` tool belonging to the chosen toolchain.

## Source, Build, and Install Directories

The source directory contains the source code that is obtained from the source package or git repository. The build directory is where the build-related files such as Makefiles, object files, and other intermediate files are stored. The install directory is where the binaries and libraries are installed, for use either by the system or by the application.

It is recommended to keep these directories separate by shadow-building and using the `-prefix` option. This enables you to keep the Qt source tree clean from the build artifacts and binaries, which are stored in a separate directory. This method is very convenient if you want to have multiple builds from the same source tree, but for different configurations. To shadow-build, run `configure` from a separate directory:

      mkdir ~/qt-build
      cd ~/qt-build
      ~/qt-source/configure -prefix /opt/Qt5.9
      qmake

Configuring with the `-prefix` option means that the Qt binaries and libraries are installed into another directory, which is `/opt/Qt5.9` in this case. Running `qmake` generates the Makefiles in the ~/qt-build directory and not in the source directory. After the Makefiles are in place, run the following commands to build the Qt binaries and libraries, and install them:

      make
      make install

Note: The 'make install' step is required only if Qt is configured with a -prefix, which is the default on Unix-based platforms unless the -developer-build configure option is used. On Windows, Qt is configured as a non-prefix build by default.

Note: The `-developer-build` is meant for developing Qt and not for shipping applications. Such a build contains more exported symbols than a standard build and compiles with a higher warning level.

## Modules and Features

Qt consists of different modules whose sources can be found in different directories inside the top-level source directory. Users can explicitly exclude specific top-level directories to limit build times. Furthermore, each Qt module might have features that can also be explicitly enabled or disabled.

### Excluding Qt Modules

Configure's `-skip` option allows top-level source directories to be excluded from the Qt build. Note that many directories contain multiple Qt modules. For example, to exclude Qt NFC and Qt Bluetooth from the Qt build, provide `-skip qtconnectivity` as the argument to configure.

      ./configure -skip qtconnectivity

### Including or Excluding Features

The `-feature-`<feature> and `-no-feature-`<feature> options include and exclude specific features, respectively.

For example, to disable Accessibility, provide `-no-feature-accessibility` as the argument:

      ./configure -no-feature-accessibility

Use `configure -list-features` to show a list of all available features on the command line. Note that features can depend on other features, so disabling a feature might have side-effects on other features.

The Qt Configuration Tool that is part of Qt for Device Creation allows the tweaking of features and dependencies through a convenient user interface.

## Third-Party Libraries

The Qt source packages include third-party libraries. To set whether Qt should use the system's versions of the libraries or to use the bundled version, pass either `-system` or `-qt` before the name of the library to configure.

The table below summarizes the third-party options:

Library Name | Bundled in Qt | Installed in System
--- | --- | ---
zlib | `-qt-zlib` | `-system-zlib`
libjpeg | `-qt-libjpeg` | `-system-libjpeg`
libpng | `-qt-libpng` | `-system-libpng`
xcb | `-qt-xcb` | `-system-xcb`
freetype | `-qt-freetype` | `-system-freetype`
PCRE | `-qt-pcre` | `-system-pcre`
HarfBuzz-NG | `-qt-harfbuzz` | `-system-harfbuzz`

It is also possible to disable support for these libraries by using `-no` instead of `-qt`. For example, to use the system's xcb library and disable zlib support, enter the following:

      ./configure -no-zlib -qt-libjpeg -qt-libpng -system-xcb

For a full list of options, consult the help with `configure -help`.

## Compiler Options

The `-platform` option sets the host platform and the compiler for building the Qt sources. The list of supported platforms and compilers is found in the supported platforms page while the full list is available in qtbase/mkspecs directory.

For example, on Ubuntu Linux systems, Qt can be compiled by several compilers such as clang or g++:

      ./configure -platform linux-clang
      ./configure -platform linux-g++
      ./configure -platform linux-g++-32

For Windows machines, either MinGW or Visual Studio toolchains can be used to compile Qt.

      configure.bat -platform win32-g++
      configure.bat -platform win32-msvc

Afterwards, the generated Makefiles will use the appropriate compiler commands.

## Cross-Compilation Options

To configure Qt for cross-platform development and deployment, the development toolchain for the target platform needs to be set up. This set up varies among the Supported Platforms.

Common options are:

- `-xplatform` - the target platform. Valid xplatform options are the same as the `-platform` options which are found in qtbase/mkspecs.
- `-device` - a specific device or chipsets. The list of devices that configure is compatible with are found in qtbase/mkspecs/devices. For more information, visit the Devices Wiki page.
- `-device-option` - sets additional qmake variables. For example, `-device-option CROSS_COMPILE=`<path-to-toolchain> provides the environment variable, `CROSS_COMPILE`, as needed by certain devices.

Note: Toolchains for non-desktop targets often come with a so-called sysroot which Qt needs to be configured against.

### Specific Options for Platforms

The following pages provide guidelines on how to configure Qt for specific platform development:

- Building Qt 5 for Android Wiki page
- Qt for iOS - Building from Source
- Qt for WinRT - Building from Source
- Qt for Embedded Linux - Building from Source
- Qt for Raspberry Pi - a community-driven site for Raspberry devices
- Devices - a list of other devices and chipsets

## OpenGL Options for Windows

On Windows, Qt can be configured with the system OpenGL or with ANGLE. By default, Qt is configured to use dynamic OpenGL. This means that it tries to use system OpenGL and falls back to ANGLE, which is bundled with Qt and depends on the DirectX SDK, if native OpenGL does not work. ANGLE enables running Qt applications that depend on OpenGL, without installing the latest OpenGL drivers. If ANGLE also fails, Qt will fall back to software rendering, which is the slowest but most safe of the rendering methods.

The `-opengl` option can be used to configure Qt to use the OpenGL in the target system, a different version of OpenGL ES (with or without ANGLE), or dynamically switch between the available OpenGL implementations.

      configure.bat -opengl dynamic

With the `dynamic` option, Qt will try to use native OpenGL first. If that fails, it will fall back to ANGLE and finally to software rendering in case of ANGLE failing as well.

      configure.bat -opengl desktop

With the `desktop` option, Qt uses the OpenGL installed on Windows, requiring that the OpenGL in the target Windows machine is compatible with the application. The `-opengl` option accepts two versions of OpenGL ES, `es2` for OpenGL ES 2.0 or `es1` for OpenGL ES Common Profile.

      configure.bat -opengl es2

You can also use `-opengl dynamic`, which enable applications to dynamically switch between the available options at runtime. For more details about the benefits of using dynamic GL-switching, see Graphics Drivers.