Using a public property extensions inside a class or object with a @Composable backing delegate fails to link for iOS targets

[MikolajKakol]

Describe the bug
Given code should compile on iOS as it does on Android, similar to #2901

class G {
    val text: String @Composable get() = "Some text"
}

or

object G {
    val text: String @Composable get() = "Some text"
}

It fails with

error: There is still an unbound symbol after generation of IR module <shared>:
Unbound public symbol IrSimpleFunctionPublicSymbolImpl: /G.text.<get-text>|8349765969627210272[0]

Affected platforms
Select one of the platforms below:

• iOS

Versions

• Kotlin version*: 1.8.20
• Compose Multiplatform version*: 1.4.0 and 1.5.0-dev1030
• OS version(s)* (required for Desktop and iOS issues): 16.2
• OS architecture (x86 or arm64): x86

To Reproduce
As in #2901

Expected behavior
It should compile

[pablichjenkov]

I can confirm this. I am using setters/getters extensions for the time being.

[adtarassov]

I also have the same problem

[FireWookie]

i have this problem

[eymar]

There is a possible workaround described here: #3175 (comment)

One more option is to change the visibility of the class if it's okay:

private class G {...}
internal class G {...}

Also, as mentioned already by @pablichjenkov:

class G {...}

val G.text
  @Composable get() = "Some text"

---

It seems that in kotlin 1.9.0 it will be possible to add @HiddenFromObjC annotation to the class - https://youtrack.jetbrains.com/issue/KT-56464/K-N-Allow-HiddenFromObjC-for-classes
That annotation should fix this issue.
With kotlin 1.9.0, we'll patch the compiler plugin to add such an annotation automatically as we already do for functions. It's not possible to add this annotation in koltin 1.8.x to classes.

[eymar]

Hey everyone!
The bugs were fixed. Please update to 1.4.1 Compose Multiplatform, and use kotlin 1.8.21 with

compose {
    kotlinCompilerPlugin.set("1.4.7")
}

In the next release, setting kotlinCompilerPlugin.set("1.4.7") won't be necessary.

[pablichjenkov]

Indeed, the problem seems to be gone with above configuration. Thanks

[MikolajKakol]

It doesn't quite work for me as

Compose Multiplatform 1.4.1 doesn't support Kotlin 1.8.21.

[eymar]

@MikolajKakol
as mentioned above, please add this to your build.gradle.kts with compose:

compose {
    kotlinCompilerPlugin.set("1.4.7")
}

In the next release, this step won't be needed.

[MikolajKakol]

Yes, I added that in the shared module in the root and I saw that error message.

[eymar]

Is "wed" also a module?
The error message comes from the compose gradle plugin. So it's likely there are modules with compose.

[pablichjenkov]

You need to add bellow code in all modules build.gradle file.

compose { 
     // Sets a specific JetBrains Compose Compiler version 
     kotlinCompilerPlugin.set("1.4.7") 
     kotlinCompilerPluginArgs.add("suppressKotlinVersionCompatibilityCheck=1.8.21") 
 }

[MikolajKakol]

That helped, I only added it for shared, sorry and thank you 😊

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.