A modern programming language that makes developers happier.

kotlinlang

screenshot_2025-08-13_at_2.22.16___pm.png

screenshot_2025-08-13_at_2.21.34___pm.png

screenshot_2025-08-13_at_2.21.17___pm.png

Hi all :android-wave: ,
In this talk by Arkadii Ivanov about Kotlin Library compatibility - <https://youtu.be/dI07ZvnwZgE?si=4DAW9GLItbe-rIuM|https://youtu.be/dI07ZvnwZgE?si=4DAW9GLItbe-rIuM>.

It is mentioned that a method changing to `synthetic` is ABI compatible.

Could anyone please help share some resources about this?

You could try to dig into the Java specification: <https://docs.oracle.com/javase/specs/jvms/se24/html/jvms-4.html#jvms-4.7.8>

But the absence of any language would probably mean that it's compatible

I usually look at <https://wiki.eclipse.org/Evolving_Java-based_APIs_2|this page> too but they don't say anything about `synthetic`

I guess in that case, the fact that it's not mentioned just means it's compatible

Is the `synthetic` and the one mentioned here same :sweat_smile: ?

<https://kotlinlang.org/api/core/kotlin-stdlib/kotlin.jvm/-jvm-synthetic/#:~:text=for%20Kotlin%20sources.-,Marking%20target%20as%20synthetic%20is%20a%20binary%20compatible%20change%2C%20already,is%20idiomatic%20for%20both%20languages|https://kotlinlang.org/api/core/kotlin-stdlib/kotlin.jvm/-jvm-synthetic/#:~:text=for%20Kotlin%20sources.-,Marking%20target%20as%20synthetic%20is%20a%20binary%20compatible%20change%2C%20already,is%20idiomatic%20for%20both%20languages>

yeah `synthetic` doesn't affect the method descriptor or accessibility in binary form, just visibility in Java source and `isSynthetic` in reflection