Java classes with annotations fail to parse

[noti0na1]

Compiler version

3.3.1
3.5.0-RC1-bin-SNAPSHOT

Should happen in every version, and in Scala 2 as well

Minimized code

// JFun.java
// Other annotations also fail, for example, @Deprecated
@FunctionalInterface
public interface JFun {
    String f(String s);
}

with an empty scala file in order to trigger the compiling: Stest.scala.

Output

> scala-cli compile JFun.java Stest.scala
Compiling project (Scala 3.3.1, JVM (17))
[error] ./JFun.java:2:1
[error] package expected but public found.
[error] public interface JFun {
[error] ^^^^^^
[error] ./JFun.java:6:1
[error] identifier expected but eof found.
Error compiling project (Scala 3.3.1, JVM (17))
Compilation failed

> scala-cli compile --scala 2 JFun.java Stest.scala
Compiling project (Scala 2.13.13, JVM (17))
[error] ./JFun.java:2:1
[error] `package` expected but `public` found.
[error] public interface JFun {
[error] ^
[error] ./JFun.java:5:1
[error] identifier expected but eof found.
[error] ^
Error compiling project (Scala 2.13.13, JVM (17))
Compilation failed

Expectation

Should compile.

Analyze

In JavaParser, it tries to read annotations with the package.

/** CompilationUnit ::= [package QualId semi] TopStatSeq
  */
def compilationUnit(): Tree = {
  val start = in.offset
  val pkg: RefTree =
    if (in.token == AT || in.token == PACKAGE) {
      annotations()
      accept(PACKAGE)
      val pkg = qualId()
      accept(SEMI)
      pkg
    }
    ...

Scala 2 also has the same issue, since this part is a direct port (and there is a TODO there).

Removing in.token == AT || from the condition and annotations() from the body makes the code compile.

[som-snytt]

Sounds like #20026

[som-snytt]

PR against the other ticket is forward-port of a fix on scala 2. #20064

The other ticket also implicates scala-cli, which I haven't tried yet.