Draft: Swift version management, Docker multi-stage build #41
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| cmd += ["-L", projectDirectoryPath.appending(components: "OnlinePlayground", "OnlinePlayground-\(toolchain.rawValue)", ".build", "debug").pathString] | ||
| #else | ||
| cmd += ["-I", projectDirectoryPath.appending(components: "OnlinePlayground", "OnlinePlayground-\(toolchain.rawValue)", ".build", "release").pathString] | ||
| cmd += ["-L", projectDirectoryPath.appending(components: "OnlinePlayground", "OnlinePlayground-\(toolchain.rawValue)", ".build", "release").pathString] |
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can't get rid of that. The OnlinePlayground-* is a helper module that is injected into each user source, and it has to work with the selected version of the swiftc - effectively need to build it with every and each supported toolchain for compatibility (less important in swift5, but it was crucial in swift 4 and 5 coexistence)
Here it's precompiled per toolchain.
what would be solution to have it?
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Aaah, my bad, the part with linking OnlinePlayground explicitly is missing here.
The idea is to pre-build the helper with Swift 5+, then link pre-build binary with user's code. The pre-build libs are located in lib directory (could optionally contain third party .frameworks on macOS). This approach drops support of Swift 4 (due to lack of ABI), but makes the system easier to understand and maintain.
If we wanted to maintain per-toolchain compilation independent on Swift version, then we could use docker images. The server app would only be responsible for starting containers and collecting its output - compilation and execution would happen in the container.
While implementing #38, I sometime struggled with steps necessary to make the app build. I'd like to pitch developer experience improvement using
swiftenvfor toolchain management.The problem
The current toolchain management is hard to understand and error-prone when managing multiple versions. The configuration of supported swift versions is spread across multiple places (build scripts, Vapor app, frontend and Docker) making maintenance real challenge.
The solution
swiftenvswiftenv versions) as the source of truth for BE and FE (using new/api/versionsendpoint)OnlinePlaygroundin favour of Swift 5 ABI (build once, link everywhere™️)Let me know if it sounds interesting to you and we can coordinate to finish this PR.