Docker to cross-compile SWI-Prolog for Windows

This docker builds SWI-Prolog for Windows using the MinGW cross-compilation toolchain from Linux. Usage:

• Get source tree if you don't have it already

	git clone https://github.com/SWI-Prolog/swipl-devel.git
        git -C swipl-devel submodule update --init

• Setup docker-swipl-build-mingw

	git clone https://github.com/SWI-Prolog/docker-swipl-build-mingw.git
	git -C docker-swipl-build-mingw submodule update --init

• Edit Makefile to make $SWIPLSRC point at a checked out source tree normally obtained using

	git clone https://github.com/SWI-Prolog/swipl-devel.git
	git submodule update --init

• By default, the Docker image creates a user swipl with the UID and GID of the user that creates the image. This user/group is used for the build process. Edit GID and UID in Makefile if you want a different scenario.

• Create the Docker image using the command below. This takes quite long. The image is pretty big (6.71Gb)

	make image

• Run the image using the command below. This create an X11 headless server for running Wine. If debugging is required it may be wise to run make run11 which sets up X11 forwarding, making Wine windows appear on your X11 deskop (requires a Unix host).

	make run

• The commands below create a fresh build.win32 (build.win64) directory, configures, builds and packages SWI-Prolog for Windows 32/64

	build_win32
	build_win64

• For updating/debugging a build, go into one of the above build directories and build using ninja. Note that the release build uses PGO optimization. If you modified any of the SWI-Prolog core sources you must either disable PGO compilation using this command, after which you can rebuild using ninja

	../scripts/pgo-compile.sh --off

or build using PGO optimization using

	../scripts/pgo-compile.sh

Issues

• The SSL test suite is currently not built. There is an issue running openssl.exe in wine in a Docker container with the random seeding.

Considerations

The Docker is built on Fedora (latest) as this distro seems to have a good balance between stability and providing up-to-date development tools. Notably the MinGW tool suite provides a lot of the dependencies we need and, unlike its Ubuntu (20.04) equivalent, PGO compilation works.