genbindings

The genbindings program regenerates the Qt bindings.

Architecture design

Bindings are generated in two passes:

Pass 1

Scan input directory for header files.
For each header file:
Run clang --ast-dump=json to get a JSON ast.
- This is somewhat slow, the results will be cached in ./cachedir after the first run.
- Strip all Clang AST nodes that were included from other files, to only consider the header's own definitions.
Convert Clang AST to our own intermediate representation.
Run some transformations on the intermediate representation.
Cache and collect the global state of all known class names, enum names, and typedefs.

Pass 2

For each intermediate-representation AST:
Emit "CABI" cpp/h pair.
- The CABI is a projection of Qt into plain C. The translation unit itself is C++, but the header can be used as extern c.
Emit Go binding file.
- The Go binding uses CGO to call into the CABI binding.

It's tested to work on with Debian 12 with system packages (Qt 5.15 / Qt 6.4 / Clang 14 / GCC 12).

You should check the following configuration:

Git clone this repository
In docker/genbindings.Dockerfile, add your library's headers and pkg-config file.
- If your library does not include a pkg-config file, you must create one.
Patch cmd/genbindings/config-libraries.go to add a new generate block for your target library
Run genbindings to regenerate all bindings
- The first run must populate clang ASTs into a cache directory and may be slower, but it is fast afterwards
Add a cflags.go file to the generated binding directory
- It should have a #cgo pkg-config: LibraryName stanza and any extra flags (e.g. --std=c++17) that are required but not system-specific
Try to use the new binding within the repo, by adding an example in the examples/libraries directory
Commit the generated bindings
- You can then use your forked MIQT repo with replace inside go.mod
- Or, open a Pull Request to add the library to MIQT