Static Linking SDL3 when using Odin on MacOS

Problem Description
Building a static SDL3 library
Approach 1: Copy the sdl3 vendor folder
Approach 2: Edit Odin's vendor/sdl3/sdl3__foreign.odin file
Miscellaneous learnings/thoughts

Problem Description

Odin doesn't ship with a pre-compiled version of SDL3 for MacOS. If you were to use Raylib with Odin, all you need to do is import "vendor:raylib" in your source code and `odin build .` With SDL3, you need to provide the library yourself. By default, Odin looks for a system installation of SDL3. I prefer not to do system installs of SDL, and usually statically link the library. While doing so, I ran into a few road blocks.

If you're in a similar situation and just want to get something working, feel free to pull down this working example from my personal git forge.

Building a static SDL3 library

SDL3 can be easily built using cmake. Pull the SDL3 source code, unzip it, and run:

cmake -B build -DCMAKE_BUILD_TYPE=RelWithDebInfo -DSDL_STATIC=ON && cmake --build build

In your `build` folder, you should now have `libSDL3.a`.

Approach 1: Copy the sdl3 vendor folder

In Odin's `vendor/sdl3/sdl3__foreign.odin` file, it defines the SDL3 import as:

when ODIN_OS == .Windows {
    @(export) foreign import lib { "SDL3.lib" }
} else {
    @(export) foreign import lib { "system:SDL3" }
}

As far as I know, there's no way to override those definitions from the importing code. Any project that wants to define a different import path will need to copy Odin's vendor/sdl3 folder and update the imports:

when ODIN_OS == .Darwin {
    @(export)
    foreign import lib {
        "./libSDL3.a",
    }
}

Then you'll need to copy the previously built `libSDL3.a` into your project's sdl3 folder. Your `main.odin` file should look something like this for testing:

package main
import "sdl3"

main :: proc() {
    _ = sdl3.Init(sdl3.INIT_VIDEO)
}

Unfortunately, running `odin build .` will result in many linker errors. To save you some trouble, here's the contents of the full `sdl3/sdl3__foreign.odin` file:

package sdl3
when ODIN_OS == .Darwin {
@(export)
foreign import lib {
    "./libSDL3.a",
    "system:Cocoa.framework",
    "system:OpenGL.framework",
    "system:IOKit.framework",
    "system:AVFoundation.framework",
    "system:CoreAudio.framework",
    "system:AudioToolbox.framework",
    "system:CoreHaptics.framework",
    "system:CoreMedia.framework",
    "system:Metal.framework",
    "system:GameController.framework",
    "system:ForceFeedback.framework",
    "system:Carbon.framework",
    "system:CoreVideo.framework",
    "system:QuartzCore.framework",
    "system:UniformTypeIdentifiers.framework",
}
}

Now re-run `odin run .` and you should be good to go!

Approach 2: Edit Odin's vendor/sdl3/sdl3__foreign.odin file

Update the contents to look like this:

package sdl3

LIBRARY_PATH :: #config(SDL3_PATH, "system:SDL3")

when ODIN_OS == .Windows {
    @(export)
    foreign import lib "SDL3.lib"
} else when ODIN_OS == .Darwin {
    when LIBRARY_PATH == "system:SDL3" {
        @(export)
        foreign import lib {LIBRARY_PATH}
    } else {
        @(export)
        foreign import lib {
            "system:" + LIBRARY_PATH,
            "system:Cocoa.framework",
            "system:OpenGL.framework",
            "system:IOKit.framework",
            "system:AVFoundation.framework",
            "system:CoreAudio.framework",
            "system:AudioToolbox.framework",
            "system:CoreHaptics.framework",
            "system:CoreMedia.framework",
            "system:Metal.framework",
            "system:GameController.framework",
            "system:ForceFeedback.framework",
            "system:Carbon.framework",
            "system:CoreVideo.framework",
            "system:QuartzCore.framework",
            "system:UniformTypeIdentifiers.framework"
        }
    }
} else {
    @(export)
    foreign import lib "system:SDL3"
}

Then, when building the project, use a command like:

odin run . -define:SDL3_PATH=<absolute path to libSDL3.a file here>

Miscellaneous learnings/thoughts

It would be great if the import path's for Odin's included vendored libraries could be configured by the user.
I'm sure that the MacOS framework files are collected somewhere on disk, but for the lazy, the full list can be found here (likely outdated)
You need to prepend the static archive's path with "system:" or else the path will be interpreted as a relbative path.