I still don’t understand the types of kotlin nativ...

# kotlin-native

[Paul Woitaschek]

I still don’t understand the types of kotlin native.
According to this table https://github.com/JetBrains/kotlin/blob/06498c0efdb218da4bd1b09b6ae0b98beb8b7af9/native/utils/src/org/jetbrains/kotlin/konan/target/KonanTarget.kt

...
    object WATCHOS_ARM32 : KonanTarget("watchos_arm32", Family.WATCHOS, Architecture.ARM32)
    object WATCHOS_ARM64 : KonanTarget("watchos_arm64", Family.WATCHOS, Architecture.ARM64)
...

And this https://github.com/JetBrains/kotlin/blob/06498c0efdb218da4bd1b09b6ae0b98beb8b7af9/native/utils/src/org/jetbrains/kotlin/konan/target/Architecture.kt

enum class Architecture(val bitness: Int) {
 ...
    ARM64(64),
    ARM32(32)
,...
}

watchosarm32 is 32 bit and watchosarm64 is 64 bit.

However when I now take a look at my watchosArm32Main source set, for example NSDateComponents have `NSInteger`s which will be interpreted as kotlin ints.
Makes sense to me.
Now however in watchosArm64Main it’s also an Int. Why is that? Why isn’t this now a Long?

Apparently all ios source sets have longs, all watchos source sets have ints. I thought this is dependent on the bitness?

[sergey.bogolepov]

Because watchOS ARM64 is a bit, let's call it, "special". When Apple introduced Apple Watch Series 4 they wanted to do two things:
1. Have a 64-bit processor
2. Port existing 32-bit apps using bitcode recompilation on their servers.
(Personally, I think it's a strange solution, but I'm not a decision-maker at Apple ¯\_(ツ)_/¯)
So they introduced a special architecture, `arm64_32`: long and pointer types are 32-bit wide there unlike usual ARM64 ABI. That's why you see Int instead of Long on watchosArm64.

[Paul Woitaschek]

Thanks 👍
This is so strange to understand. I was trying to create intermediate source sets to handle all the long / bit magic

[Paul Woitaschek]

I have so much logic duplicated due to the issue described here
https://kotlinlang.slack.com/archives/C3SGXARS6/p1614864836082500?thread_ts=1614864836.082500&cid=C3SGXARS6