qt5base-lts/cmake
Frederik Gladhorn ed487cb00a CMake: Fix detection of AT-SPI-2 on second run
The if around the find logic meant that the module was never shown as
found after the first round.

Change-Id: I3dd47b37baf7c630c54adbce6872b99f9ff56ad0
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
2019-09-16 14:47:51 +00:00
..
3rdparty CMake: Remove 3rdparty/kwin/FindFontconfig.cmake 2019-03-29 09:33:56 +00:00
QtBuildInternals Use $$source_path/qtbase/cmake modules when doing non-prefix builds 2019-09-06 09:33:38 +00:00
tests CMake: Introduce Qt::GlobalConfig to hold the global features 2019-01-17 08:33:27 +00:00
3rdpartyConfig.cmake.in cmake: export locally-built dependencies in static build 2019-05-02 11:41:55 +00:00
FindAtomic.cmake Fix a few of the Wrap modules to protect against double creation of 2019-06-05 12:30:47 +00:00
FindATSPI2.cmake CMake: Fix detection of AT-SPI-2 on second run 2019-09-16 14:47:51 +00:00
FindCups.cmake CMake: Add FindCups.cmake from upstream cmake 2019-04-03 08:54:14 +00:00
FindDB2.cmake cmake: Enable building of the db2 plugin 2019-09-04 09:50:15 +00:00
Finddouble-conversion.cmake cmake: Only use the doubleconversion cmake config if "valid" 2019-02-01 12:26:43 +00:00
FindGLESv2.cmake Fix Desktop GL/EGL/GLESv2 linkage 2019-02-12 14:57:30 +00:00
FindGTK3.cmake Fix static usage requirements for XcbQpa 2019-06-05 08:53:34 +00:00
FindLibproxy.cmake Fix cmake generate step when cross-compilation against Android 2019-06-03 11:36:22 +00:00
FindLibsystemd.cmake Fix cmake generate step when cross-compilation against Android 2019-06-03 11:36:22 +00:00
FindLibudev.cmake Fix cmake generate step when cross-compilation against Android 2019-06-03 11:36:22 +00:00
FindMtdev.cmake Fix cmake generate step when cross-compilation against Android 2019-06-03 11:36:22 +00:00
FindMySQL.cmake Enable building of the mysql plugin 2019-09-02 15:16:42 +00:00
FindOracle.cmake cmake: Enable building of the oci plugin 2019-09-05 08:24:07 +00:00
FindPPS.cmake Write find_dependency() calls in Qt Module config files 2019-05-02 07:30:42 +00:00
FindSlog2.cmake Write find_dependency() calls in Qt Module config files 2019-05-02 07:30:42 +00:00
FindTslib.cmake Fix static usage requirements for XcbQpa 2019-06-05 08:53:34 +00:00
FindWrapDBus1.cmake cmake: Correct way to save/restore env vars 2019-05-10 16:33:15 +00:00
FindWrapDoubleConversion.cmake Fix a few of the Wrap modules to protect against double creation of 2019-06-05 12:30:47 +00:00
FindWrapFreetype.cmake CMake: Allow build with MinGW and Hunter 3rd party packages 2019-06-04 10:12:27 +00:00
FindWrapPCRE2.cmake CMake: Add WrapPCRE2 package 2019-06-05 09:42:55 +00:00
FindWrapRt.cmake Fix a few of the Wrap modules to protect against double creation of 2019-06-05 12:30:47 +00:00
FindXKB_COMMON_X11.cmake Fix static usage requirements for XcbQpa 2019-06-05 08:53:34 +00:00
FindXRender.cmake cmake: Fix xcb build 2019-06-04 08:45:46 +00:00
FindZSTD.cmake Fix static zstd linkage 2019-05-24 14:19:51 +00:00
qt.toolchain.cmake.in Fix osx deployment target and sysroot propagation in the qt toolchain 2019-06-26 11:38:01 +00:00
QtAutoDetect.cmake Add auto detection routines for android 2019-06-27 13:45:58 +00:00
QtBaseCMakeTesting.cmake CMake: Add option to run cmake build tests 2018-11-22 08:39:12 +00:00
QtBaseConfigureTests.cmake Fix architecture detection with WASM builds 2019-08-28 13:23:50 +00:00
QtBaseGlobalTargets.cmake Prospective fix for linking problems of qtdeclarative in the CI 2019-09-03 08:22:03 +00:00
QtBuild.cmake Fix OUTPUT_TARGET propagation in qt6_add_resource() 2019-09-16 11:41:48 +00:00
QtBuildInternalsExtra.cmake.in Propagate BUILD_TESTING and BUILD_EXAMPLES 2019-09-06 18:09:18 +00:00
QtCompilerFlags.cmake cmake: Start adding compiler flags 2019-02-21 13:51:19 +00:00
QtCompilerOptimization.cmake Add MSVC specific instruction set compiler flags 2019-03-21 17:47:09 +00:00
QtConfig.cmake.in Merge remote-tracking branch 'origin/wip/qt6' into wip/cmake 2019-06-14 16:31:09 +02:00
QtFeature.cmake Map module.gui to if TARGET Qt::Gui in configure.cmake 2019-06-05 09:15:04 +00:00
QtInternalTargets.cmake Check for the correct apple clang version with warnings_are_errors 2019-06-24 14:52:59 +00:00
QtModuleConfig.cmake.in Fix creation of generated plugin cpp files in static builds 2019-07-30 13:26:37 +00:00
QtModuleDependencies.cmake.in Fix building against an installed static Qt 2019-06-25 13:38:33 +00:00
QtModuleToolsConfig.cmake.in Allow to build examples as standalone project 2019-06-05 12:53:28 +00:00
QtModuleToolsDependencies.cmake.in Make module package depend on its own tool package 2019-05-02 07:30:55 +00:00
QtPlatformAndroid.cmake Override qmlimportscanner path in android deployment settings 2019-08-30 13:12:59 +00:00
QtPlatformSupport.cmake Fix WASM platform detection 2019-08-30 08:37:28 +00:00
QtPluginConfig.cmake.in Fix static builds after revamp of add_qt_resource 2019-08-30 08:24:37 +00:00
QtPluginDependencies.cmake.in Fix building against an installed static Qt 2019-06-25 13:38:33 +00:00
QtPlugins.cmake.in Fix building examples when doing a Qt static build 2019-07-22 18:48:17 +00:00
QtPostProcess.cmake Fix unnecessary find_package calls for shared builds, part 2 2019-09-06 09:45:59 +00:00
QtProperties.cmake Simplify resource embedding for qml modules 2019-08-09 11:47:25 +00:00
QtResource.cmake.in Fix merge typo in QtResource.cmake.in 2019-09-16 12:24:14 +00:00
QtSetup.cmake Propagate BUILD_TESTING and BUILD_EXAMPLES 2019-09-06 18:09:18 +00:00
QtToolsConfig.cmake.in Export tool config and target files for each relevant module 2019-05-02 07:30:30 +00:00
README.md Reflow text in cmake/README.md to be less than 100 chars per line 2019-09-10 14:19:51 +00:00

Status

Initial port is on-going. Some modules of QtBase are ported, incl. some of the platform modules. Many libraries, tests and examples are still missing.

Basic functionality is there (moc, uic, etc.), but documentation, translations, etc. are missing.

NOTE: YOU NEED CMAKE 3.15 or later.

Intro

The CMake update offers an opportunity to revisit some topics that came up during the last few years.

  • The Qt build system does not support building host tools during a cross-compilation run. You need to build a Qt for your host machine first and then use the platform tools from that version. The decision to do this was reached independent of cmake: This does save resources on build machines as the host tools will only get built once.

  • 3rd-party dependencies are no longer built as part of Qt. zlib, libpng, etc. from src/3rdparty need to be supplied from the outside to the build now. You may find apt-get/brew/etc. useful for this. Otherwise you may consider using vcpkg as in the next section. The decision to remove 3rd party dependencies from Qt repositories was reached independent of the decision to use cmake, we just use the opportunity to implement this decision.

  • There is less need for bootstrapping. Only moc and rcc (plus the lesser known tracegen and qfloat16-tables) are linking against the bootstrap Qt library. Everything else can link against the full QtCore. This will include qmake, which is currently missing from a cmake build. This will change: Qmake is supported as a build system for applications using Qt going forward and will not go away anytime soon.

  • For the time being we try to keep qmake working so that we do not interfere too much with ongoing development.

Building against VCPKG on Windows

You may use vcpkg to install dependencies needed to build QtBase.

  • git clone -b qt https://github.com/tronical/vcpkg
  • Run bootstrap-vcpkg.bat or bootstrap-vcpkg.sh
  • Set the VCPKG_DEFAULT_TRIPLET environment variable to qt-x64-windows-static or qt-x86-windows-static
  • Set the VCPKG_ROOT environment variable to the path where you cloned vcpkg
  • Build Qt dependencies: vcpkg install @qt-packages-windows.txt
  • When running cmake in qtbase, support for vcpkg will be picked up automatically when the VCPKG_ROOT/VCPKG_DEFAULT_TRIPLET environment variable is set.

Building against homebrew on macOS

You may use brew to install dependencies needed to build QtBase.

  • Install homebrew: /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
  • Build Qt dependencies: brew install pcre2 harfbuzz freetype
  • Install cmake: brew install cmake
  • When running cmake in qtbase, pass -DCMAKE_PREFIX_PATH=/usr/local

Building

The basic way of building with cmake is as follows:

    cd {build directory}
    cmake -DCMAKE_INSTALL_PREFIX=/path/where/to/install {path to source directory}
    cmake --build .
    cmake --install .

You need one build directory per Qt module. The build directory can be a sub-directory inside the module qtbase/build or an independent directory qtbase_build. The installation prefix is chosen when running cmake by passing -DCMAKE_INSTALL_PREFIX. To build more than one Qt module, make sure to pass the same install prefix.

cmake --build and cmake --install are simple wrappers around the basic build tool that CMake generated a build system for. It works with any supported build backend supported by cmake, but you can also use the backend build tool directly, e.g. by running make.

CMake has a ninja backend that works quite well and is noticeably faster than make, so you may want to use that:

    cd {build directory}
    cmake -GNinja -DCMAKE_INSTALL_PREFIX=/path/where/to/install {path to source directory}
    cmake --build .
    cmake --install .

You can look into the generated build.ninja file if you're curious and you can also build targets directory such as ninja lib/libQt6Core.so.

Make sure to remove CMakeCache.txt if you forgot to set the CMAKE_INSTALL_PREFIX on the first configuration, otherwise a second re-configuration will not pick up the new install prefix.

You can use cmake-gui {path to build directory} or ccmake {path to build directory} to configure the values of individual cmake variables or Qt features. After changing a value, you need to choose the configure step (usually several times:-/), followed by the generate step (to generate makefiles/ninja files).

Developer Build

When working on Qt itself, it can be tedious to wait for the install step. In that case you want to use the developer build option, to get as many auto tests enabled and no longer be required to make install:

    cd {build directory}
    cmake -GNinja -DCMAKE_INSTALL_PREFIX=/path/to/qtbase_build -DFEATURE_developer_build=ON {path to source directory}
    cmake --build .
    # do NOT make install

Specifying configure.json features on the command line

QMake defines most features in configure.json files, like -developer-build or -no-opengl.

In CMake land, we currently generate configure.cmake files from the configure.json files. If the feature in configure.json has the name "dlopen", you can specify whether to enable or disable that feature in CMake with a -D flag on the CMake command line. So for example -DFEATURE_dlopen=ON or -DFEATURE_sql_mysql=OFF. At the moment, if you change a FEATURE flag's value, you have to remove the CMakeCache.txt file and reconfigure with CMake. And even then you might stumble on some issues when reusing an existing build, because of an automoc bug in upstream CMake.

Ninja reconfiguration bug

If you use the Ninja generator, there's a bug that after the first CMake configuration, if you run ninja, it will do the reconfiguration step again. This is quite annoying and time consuming.

There is an open pull request that fixes the issue at https://github.com/ninja-build/ninja/pull/1527. You can build your own Ninja executable until the request is merged.

    cd {some directory}
    git clone https://github.com/ninja-build/ninja.git
    cd ninja && mkdir build && cd build
    git remote add fix git@github.com:mathstuf/ninja.git && git fetch --all
    git cherry-pick 29a565f18e01ce83ca14801f4684cd2acaf00d4c
    ../configure.py --bootstrap
    cp ninja /usr/local/bin/ninja

Building with CCache

You can pass -DQT_USE_CCACHE=ON to make the build system look for ccache in your PATH and prepend it to all C/C++/Objective-C compiler calls. At the moment this is only supported for the Ninja and the Makefile generators.

Cross Compiling

Compiling for a target architecture that's different than the host requires one build of Qt for the host. This "host build" is needed because the process of building Qt involves the compilation of intermediate code generator tools, that in turn are called to produce source code that needs to be compiled into the final libraries. These tools are built using Qt itself and they need to run on the machine you're building on, regardless of the architecure you are targeting.

Build Qt regularly for your host system and install it into a directory of your choice using the CMAKE_INSTALL_PREFIX variable. You are free to disable the build of tests and examples by setting BUILD_EXAMPLES=OFF and BUILD_TESTING=OFF.

With this installation of Qt in place, which contains all tools needed, we can proceed to create a new build of Qt that is cross-compiled to the target architecture of choice. You may proceed by setting up your environment. The CMake wiki has further information how to do that at

https://gitlab.kitware.com/cmake/community/wikis/doc/cmake/CrossCompiling

Yocto based device SDKs come with an environment setup script that needs to be sourced in your shell and takes care of setting up environment variables and a cmake alias with a toolchain file, so that you can call cmake as you always do.

In order to make sure that Qt picks up the code generator tools from the host build, you need to pass an extra parameter to cmake:

    -DQT_HOST_PATH=/path/to/your/host_build

The specified path needs to point to a directory that contains an installed host build of Qt.

Cross Compiling for Android

In order to cross-compile Qt to Android, you need a host build (see instructions above) and an Android build. In addition, it is necessary to install the Android NDK as well as vcpkg. Vcpkg is needed to supply third-party libraries that Qt requires but that are not part of the Android NDK.

Vcpkg for Android can be set up using the following steps:

  • git clone -b qt https://github.com/tronical/vcpkg
  • Run bootstrap-vcpkg.bat or bootstrap-vcpkg.sh
  • Set the VCPKG_DEFAULT_TRIPLET environment variable to on of the following values:
    • arm-android (armeabi-v7a)
    • arm64-android (arm64v8)
    • x86-android (x86)
    • x64-android (x86_64)
  • Set the VCPKG_ROOT environment variable to the path where you cloned vcpkg
  • Set the ANDROID_NDK_HOME environment variable to the path where you have installed the Android NDK.
  • Set the ANDROID_SDK_HOME environment variable to the path where you have installed the Android SDK.
  • Build Qt dependencies: vcpkg install @qt-packages-android.txt

When running cmake in qtbase, pass -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK_HOME/build/cmake/android.toolchain.cmake -DQT_HOST_PATH=/path/to/your/host/build -DANDROID_SDK_ROOT=$ANDROID_SDK_HOME -DCMAKE_INSTALL_PREFIX=$INSTALL_PATH

If you don't supply the configuration argument -DANDROID_ABI=..., it will default to armeabi-v7a. To target other architectures, use on of the following values:

  • arm64: -DANDROID_ABI=arm64-v8
  • x86: -DANDROID_ABI=x86
  • x86_64: -DANDROID_ABI=x86_64

By default we set the android API level to 21. Should you need to change this supply the following configuration argument to the above CMake call: -DANDROID_NATIVE_API_LEVEL=${API_LEVEL}

Debugging CMake files

CMake allows specifying the --trace and --trace-expand options, which work like qmake -d -d: As the cmake code is evaluated, the values of parameters and variables is shown. This can be a lot of output, so you may want to redirect it to a file.

Porting Help

We have some python scripts to help with the conversion from qmake to cmake. These scripts can be found in utils/cmake.

configurejson2cmake.py

This script converts all configure.json in the Qt repository to configure.cmake files for use with CMake. We want to generate configure.cmake files for the foreseeable future, so if you need to tweak the generated configure.cmake files, please tweak the generation script instead.

configurejson2cmake.py is run like this: util/cmake/configurejson2cmake.py . in the top-level source directory of a Qt repository.

pro2cmake.py

pro2cmake.py generates a skeleton CMakeLists.txt file from a .pro-file. You will need to polish the resulting CMakeLists.txt file, but e.g. the list of files, etc. should be extracted for you.

pro2cmake.py is run like this: /path/to/pro2cmake.py some.pro.

run_pro2cmake.py

`` A small helper script to run pro2cmake.py on all .pro-files in a directory. Very useful to e.g. convert all the unit tests for a Qt module over to cmake;-)

run_pro2cmake.py is run like this: /path/to/run_pro2cmake.py some_dir.

How to convert certain constructs

qmake CMake
qtHaveModule(foo) if(TARGET Qt::foo)
qtConfig(foo) if (QT_FEATURE_foo)