Is it possible to load an SPM framework/dylib at runtime under Linux

tkrajacic · April 18, 2018, 6:50am

I can use Bundle on macOS to load a framework at runtime, and that works reasonably well even with Swift (given the principal class is @objc). Can I do something similar under Linux?

A similar question has been posted quite a while ago without any answer (How do you dynamically load a module on Linux?)

Given that Swift has advanced quite a bit, is this possible now?

Can I load a framework/dylib under linux at runtime and use it? Bundle seems to be mostly unimplemented in corelibs foundation.

Lope · April 18, 2018, 11:05am

It is definitely possible to load dylib in linux using swift, I made a little example app couple months ago to document a bug in SPM. You can see implementation here:

github.com

Lopdo/SwiftPlugins-PluginConsumer/blob/master/Sources/PluginConsumer/main.swift

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This file has been truncated. show original

there are two related projects, one that defines plugin's interface and other that show how actual plugin is implemented:

Not sure if this is exactly what you need, but it is possible to load your own dylib and interface with it

tkrajacic · April 19, 2018, 7:58am

Ok the problem here is that only C functions can be called, and Swift libraries are not really supported.

I guess my question is if there is any kind of story or roadmap on how and when this is planned to be properly supported (not just on Linux). I mean even on macOS the requirement to only use Obj-C protocols leaves a lot to be desired.

Anyone? @Tony_Parker?

Tony_Parker · April 20, 2018, 10:09pm

I think we can start with a JIRA, for the Linux bit.

This may depend on ABI and module stability; otherwise loading some bit of Swift code that was not compiled with the rest of your code may result in some strange behavior.

tkrajacic · April 21, 2018, 4:57am

Thank you Tony for your answer. Makes sense that it is tied to ABI stability. I can't wait though when Swift on Linux is fully usable™

Should I file the issue on Jira? I guess you are a lot better at wording it though

felix91gr · April 21, 2018, 5:07am

Maybe @Aciid knows something about this ?

Tony_Parker · April 21, 2018, 3:31pm

Please feel free to create one yourself, and put a link here. Thanks!

tkrajacic · April 22, 2018, 6:20am

I created [SR-7494] Allow loading SPM frameworks at runtime and calling Swift functions on them · Issue #50037 · apple/swift · GitHub

Please feel free to fix terminology mistakes. I have no CS ed after all.

Thank you for your kind support.