openslide-bin

This is a set of scripts for building OpenSlide and its dependencies for Windows, macOS, and Linux. The resulting binaries only depend on the default platform libraries on each platform: the UCRT on Windows, SDK libraries on macOS, and glibc on Linux.

Building

For Windows and Linux, the build runs in a container image that includes the necessary tools. To build for Windows, pull the container image on Linux or in Windows PowerShell with WSL 2 and use it to run a build:

docker run -ti --rm -v ${PWD}:/work -w /work \
    ghcr.io/openslide/winbuild-builder ./bintool bdist

Similarly, to build for Linux:

docker run -ti --rm -v ${PWD}:/work -w /work \
    ghcr.io/openslide/linux-builder ./bintool bdist

macOS builds run directly on a macOS system, which can be either Intel or Apple silicon. The build will produce a universal binary in either case. The macOS SDK must be installed.

./bintool bdist

Substitute sources

To override the source tree used to build a project, create a top-level directory named override and place the substitute source tree in a subdirectory named after the project's ID. A list of project IDs can be obtained by running ./bintool projects.

bintool subcommands

sdist

Build tar.gz archive containing build system and sources for OpenSlide and all dependencies.

bdist

Build Zip or tar.xz archive containing OpenSlide binaries.

smoke

Manually run a smoke test on a bdist archive. bdist automatically runs smoke tests after Linux and macOS builds, but not after Windows builds.

versions

Produce a composite VERSIONS.md listing all project versions from one or more bdist archives.

clean

Delete build and binary directories, but not downloaded tarballs.

updates

Check for new releases of component projects.

version

Report the version number that will be used in archive file names.

projects

Report the IDs and display names of all component projects.

Adding a new dependency

openslide-bin produces binaries which do not link with shared libraries from the build environment, except for specific platform libraries on each supported OS. To add a library dependency to openslide-bin, you must configure openslide-bin to build that library itself.

All dependencies must be built with Meson, even those that don't natively support Meson. For many common libraries, a Meson port is available from Meson's wrapdb. Otherwise, you'll need to port the library's build system to Meson and submit the port to wrapdb (or to the upstream project if its maintainers are interested).

To add a dependency to openslide-bin:

1. Use meson wrap install to add the dependency's wrap file from wrapdb to the subprojects directory.
2. Add the dependency to _PROJECTS in common/software.py.
   • Test the update_url and update_regex by running ./bintool updates. A successful run will not produce an output line for the new dependency.
3. Modify deps/meson.build to invoke the build, in the correct order relative to the other dependencies. Include any necessary build options, e.g. disable building command-line tools to reduce build time.

Common problems

New dependencies sometimes have build bugs that need to be fixed in wrapdb or upstream. Common problems include:

1. Libraries dllexporting their public symbols when built as a Windows static library. dllexport should only be used when building a dynamic library.
2. Libraries taking an unintended dependency on pthreads. Many libraries use Windows threading primitives on Windows but unconditionally depend on dependency('threads') in their meson.build, thus adding a dependency on the pthreads library. openslide-bin intentionally does not ship a pthreads implementation.

Either issue will cause the build or smoke test to fail. The subproject can be patched by adding a patch file to the subprojects/packagefiles directory and adding a diff_files directive to the subproject's wrap file.

Submitting a PR

When adding a new dependency to OpenSlide, the corresponding openslide-bin PR should be be submitted early in the development process, since OpenSlide's CI will not pass on Windows until the dependency is available in openslide-bin. The subproject() call in deps/meson.build should initially be gated behind if dev_deps, causing the new subproject to be omitted from openslide-bin releases until the feature lands in an OpenSlide release.

All openslide-bin subprojects must use wraps from wrapdb, so new Meson ports should be submitted there first. (wrapdb does not expect ports to include all functionality from the upstream build system. For example, obscure options and CPU architectures can be omitted.) As an exception, wraps for newly-developed libraries can point directly to an upstream Git commit while the library is being integrated into OpenSlide. However, the wrap must be added to wrapdb before the first OpenSlide release that uses the library.

Similarly, all diff_files directives in wrap files must have a comment linking to a wrapdb PR or upstream PR for the patch.