Building Qt Documentation
Note: For information about writing documentation for Qt, see the Writing Qt Documentation page. For help on troubleshooting documentation builds, see the Troubleshooting Qt Documentation page.
Building Qt6 Documentation
Building Qt5 Documentation
QDoc (qdoc command in qtbase) builds the documentation and is included in standard Qt 5 installations. The official Qt documentation is built using Linux based machines, requiring libraries needed for building Qt 5 and tested on the supported desktop platforms.
Important: When using CMake, regular Makefile targets are not generated by default. On most platforms in Qt6, ninja is used by default. So, instead of "make docs" you would call "ninja docs" or "ninja html_docs" or "cmake --build . docs", for example
Build Requirements
From Qt version 5.11, libclang/LLVM/libllvm is required to build QDoc. The following versions are required (See also Installing Clang for QDoc):
- On Linux and macOS, use libclang version >= 3.9. The package clang is required on many Linux systems to obtain the required Cmake files.
- On Windows, use libclang version >= 6.0. The prebuild libclang from download.qt.io can be used. Note that the prebuild library is a release build and that qdoc has to be build in release mode too. Further note QTBUG-108391 and that some cmake files might require editing.
- From Qt version 6, libclang/LLVM/libllvm version >= 10.0 is required.
If LLVM is not installed or not found in the package tree of your system, QDoc will not be built and you will not be able to build documentation. Once LLVM is installed, the LLVM_INSTALL_DIR environment variable must be set pointing to its top-level installation directory.
Required reading
- Get the Source Code - download the Qt sources
- Building Qt 5 - build instructions for Qt 5
If the source is obtained via git, ensure that the submodule
qttools
is checked out. For the standard installation of the Qt 5 repository (qt5.git), once Qt is built and installed, running make docs in the command line will build QDoc and the Qt 5 documentation set. The output will be located in qt5/qtbase/doc/ or to the directory set to qmake's QT_INSTALL_DOCS variable.
cd qt5/
make docs
In many cases, building all of Qt 5 is not necessary. To build the documentation, it is necessary to build QDoc (to generate HTML documentation) and qhelpgenerator (to package the HTML documentation into .qch files). These are both located in the qttools repository.
QDoc and qhelpgenerator depend on several Qt modules from qtbase. After the configuration step, build qtbase:
cd qt5/qtbase
make
Additionally, QDoc depends on the QML DevTools library from qtdeclarative:
cd qt5/qtdeclarative/src
make sub-qmldevtools
To build the documentation tools:
cd qt5/qttools/src
make sub-qdoc
If only HTML documentation is needed, the step below, building qhelpgenerator is not required.
cd qt5/qttools/src/assistant
make sub-qhelpgenerator
To now build the documentation:
cd qt5/
make qmake_all # needed on Qt configured for prefix build to update the per-module index directories
make docs # or just make html_docs if only HTML documentation is needed
On Windows, you may use the native nmake tool, instead.
Shadow builds
For shadow builds, the source directory and install directories are different and the global templates need to be moved to the install directories. To do so, run:
cd qtbase
make install_global_docs
Building the Module Documentation
The Qt modules have their documentation built by running make docs in the command line once Qt 5 is built and installed.
cd qt3d
make docs
Running qdoc Directly
QDoc builds are specified in qdocconf files which tells QDoc where to look and how to set up documentation. To run QDoc, pass the qdocconf file and the output directory as arguments.
qdoc qt3d.qdocconf -outputdir html
Note however that since Qt 5.11, QDoc uses a Clang-based parser for documenting C++ classes; this requires that also the correct include paths are passed to Clang. QDoc accepts -I<path> command line arguments, just like a compiler does. Additional include paths can be also defined in a .qdocconf file, using the includepaths configuration variable.
Modularized Documentation
The modules have a qdocconf file in the src directory. The Qt_Documentation_Structure page has more information.
Building Qt4 Documentation
Build Qt as normal.
Define environment variables for QT_SOURCE_TREE and for QT_BUILD_TREE appropriately. Make sure the PATH environment variable points to the bin directory containing the qdoc3 executable.
cd path/to/qt
make docs
For the online docs it may be necessary to use
cd path/to/qt
make online_docs
for later versions of Qt.
For Windows™ use the nmake utility instead of make. Some Linux systems will require gmake instead of make.
If you already have Qt compiled (from the SDK, for example) and want to build some special flavour of the doc, you can call directly qdoc3 (QT_SOURCE_TREE, QT_BUILD_TREE, and QTDIR must be set appropriately), here for DITA output:
cd qt-src
bin/qdoc3 tools/qdoc3/test/qt-ditaxml.qdocconf