SPM System Library target functions not seen by Swift

Using Swift
,
1

I'm trying to create a Swifified version of the allegro game library (```brew install pkg-config allegro``) and it feels like I'm almost there but I'm missing a crucial step as the functions of the library aren't visible from the Swift side.

The package can be found here: GitHub - SwiftStudies/Allegro: Swiftied version of the Allegro 5 C game library

I'm getting an error that al_init() is an unresolved identifier. This is the only error I get from the build process (everything else... finding headers etc seems to work fine now)

As a quick test I added a string constant to the c header for the system library target and that is found and builds fine (see Allegro.version in Allegro.swift).

What am I doing wrong?

2

It looks like al_init is a macro, not a real function. Swift only knows how to handle very simple macros at this time. However, you should be able to expand the macro yourself to handle this.

2 Likes
3

Oh thank you. It's been so long since I've done any C I had forgotten how you don't really know what anything is!

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4

A useful trick is looking at the swift interface of the C library by generating an Xcode project using swift package generate-xcodeproj.

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5

I love that idea... but really dumb question... once in Xcode how do I do that? The generated project is excluding the c/h files, so I can't see them there... and the only "Product" is the final framework which doesn't expose any of these things...

What am I not seeing?

6

Forget it! Right click on the CAllegro import!

Thank you SO much... pro tip!!!

1 Like