sbt-javah mangles names of @native methods in objects incorrectly

[mrobakowski]

object Foo {
  @native def bar()
}

should generate

JNIEXPORT void JNICALL Java_Foo_00024_bar
  (JNIEnv *, jobject);

but instead it generates

JNIEXPORT void JNICALL Java_Foo___bar
  (JNIEnv *, jobject);

... at least on recent JVMs. This seems to be already fixed in gjavah, but for some reason $ is special-cased in here https://github.com/jodersky/sbt-jni/blob/fb2c301d550cee5491780b40b6e87b7e3fc73163/plugin/src/main/java/ch/jodersky/sbt/jni/javah/Utils.java#L55-L56

[jodersky]

Thanks for the pointers. I think that at the time I included gjavah in sbt-jni it didn't support special characters, so I just added the $ case to replicate what javah generated in the past.

If you have a general fix however, I'd be happy to merge it

[mrobakowski]

In my case (I'm on JDK 14) the last branch of the if-else statement (builder.append(String.format("_0%04x", (int) ch))) produces the correct result. So just removing the special case for dollar sign would fix this. I'm not sure about other JDK versions though.

[pomadchin]

@mrobakowski 👋 could you check how the current main branch works for you? #43 is merged so it could affect some things.

[jodersky]

FYI, I recently migrated gjavah to scala and fixed the issues with symbols. See here: https://github.com/jodersky/mill-jnilib/blob/master/jnilib/src/jnilib/gjavah.scala

I can confirm that it works, even with Scala 3 top-level functions and all sorts of funky characters.

[pomadchin]

@jodersky Thanks for confirming that! 🎉

sbt-jni snapshots live here now: https://oss.sonatype.org/content/repositories/snapshots/com/github/sbt/sbt-jni_2.12_1.0/ and should be easier to test to other folks.

Let's close it for now, but @mrobakowski feel free to create a new issue and / or reopen this one.

Resolved via #43

[jodersky]

oh, I realize that my comment was ambiguous. When I said "it works", I meant that my gjavah scala port works. I can't speak for the updated official version.

Thanks for setting up maven publishing again!

[pomadchin]

Ooops! I'll reopen it again than :D

[pomadchin]

@mrobakowski btw, we can add the latest JDK into CI if it helps.

[mrobakowski]

Hi @pomadchin, sorry for not replying earlier. I don't even remember what project I needed this for 😅, so I cannot confirm or deny whether it works for my problem (I probably abandoned that side-project already). But the fix looks good, so thank you for that! 🎉