qTox/windows/cross-compile

Cross-compile from Linux

Intro

Following these instructions you will be able to cross-compile qTox to Windows.

This script can be used by qTox power users to cross-compile qTox themselves,as well as by qTox developers to make sure their local changes don't break cross-compilation to Windows.

Note that the compilation script doesn't build the updater and doesn't produce an installer.

Usage

Install Docker.

You should have 3 directories available (names don't have to match the given ones):

1. workspace -- a directory that will contain a cache of qTox dependencies and the final qTox cross-compilation build. You should create this directory.
2. script -- a directory that contains the build.sh script. You can use this directory for this, there is no need to create a new one.
3. qtox -- a root directory of a qTox repository. This directory contains qTox source code that will be cross-compiled. You can use the root of this qTox repository, there is no need to create a new one.

These directories will be mounted inside a Docker container at /workspace, /script and /qtox.

The contents of qtox and script directories wouldn't be modified. The build.sh script actually makes a copy of qtox directory and works on that copy.

Once you sort out the directories, you are ready to run the build.sh script in a Docker container.

Note that the build.sh script takes 2 arguments: architecture and build type. Valid values for the architecture are i686 for 32-bit and x86_64 for 64-bit. Valid values for the build type are release and debug. All case sensitive.

Now, to start the cross-compilation, for example, for a 32-bit release qTox, run

sudo docker run --rm \
                -v /absolute/path/to/your/workspace:/workspace \
                -v /absolute/path/to/your/script:/script \
                -v /absolute/path/to/your/qtox:/qtox \
                debian:stretch-slim \
                /bin/bash /script/build.sh i686 release

If you are a qTox developer, you might want to instead run

# Get shell inside Debian Stretch container so that you can poke around if needed
sudo docker run -it \
                --rm \
                -v /absolute/path/to/your/workspace:/workspace \
                -v /absolute/path/to/your/script:/script \
                -v /absolute/path/to/your/qtox:/qtox \
                debian:stretch-slim \
                /bin/bash
# Run the script
bash /script/build.sh i686 release

This will cross-compile all of the qTox dependencies and qTox itself, storing them in the workspace directory. The first time you run it for each architecture, it will take a long time for the cross-compilation to finish, as qTox has a lot of dependencies that need to be cross-compiled. It takes my Intel Core i7 processor about 125 minutes for the cross-compilation to get done on a single core, and about 30 minutes using all 8 hyperthreads. But once you do it once for each architecture, the dependencies will get cached inside the workspace directory, and the next time you build qTox, the build.sh script will skip recompiling them, going straight to compiling qTox, which is a lot faster -- about 8 minutes on a single core and 2 minutes using 8 hyperthreads.

The structure of workspace directory that the build.sh script will create is as follows:

workspace
├── i686
│   ├── dep-cache
│   │   ├── libffmpeg
│   │   ├── libfilteraudio
│   │   ├── libopenal
│   │   ├── libopenssl
│   │   ├── libopus
│   │   ├── libqrencode
│   │   ├── libqt5
│   │   ├── libsodium
│   │   ├── libsqlcipher
│   │   ├── libtoxcore
│   │   └── libvpx
│   └── qtox
│       ├── debug
│       └── release
└── x86_64
    ├── dep-cache
    │   ├── libffmpeg
    │   ├── libfilteraudio
    │   ├── libopenal
    │   ├── libopenssl
    │   ├── libopus
    │   ├── libqrencode
    │   ├── libqt5
    │   ├── libsodium
    │   ├── libsqlcipher
    │   ├── libtoxcore
    │   └── libvpx
    └── qtox
        ├── debug
        └── release

The dep-cache directory is where all cross-compiled qTox dependencies will be cached for the future runs. You can remove any directory inside deps, which will result in the build.sh re-compiling the missing dependency.

The qtox directory, split into debug and release, is where the cross-compiled qTox will be stored.