Line number off-by-1 in stack trace

[armanbilge]

Compiler version

3.3.1-RC1-bin-20230504-0e00420-NIGHTLY

Minimized code

package com.example

object Bar {

  def void(): Unit =
    throw new Exception

  def main(args: Array[String]): Unit = {
    this
      .void() // this is line 10
  }
}

Output

Exception in thread "main" java.lang.Exception
        at com.example.Bar$.void(test.scala:6)
        at com.example.Bar$.main(test.scala:9)
        at com.example.Bar.main(test.scala)

Expectation

at com.example.Bar$.main(test.scala:9) would ideally be at com.example.Bar$.main(test.scala:10), right?

[som-snytt]

Same backend behavior in Scala 2.

It's not off-by-one, but the whole tree gets the same line number.

thing
  .self
  .bomb()

[armanbilge]

but the whole tree gets the same line number.

What is the "whole tree"? For example consider:

package com.example

object Bar {

  def self(x: Any): Bar.type =
    this

  def void(): Unit =
    throw new Exception

  def main(args: Array[String]): Unit = {
    this
      .self((x: Int) => x)
      .void() // this is line 14
  }
}

Exception in thread "main" java.lang.Exception
        at com.example.Bar$.void(test.scala:9)
        at com.example.Bar$.main(test.scala:13)
        at com.example.Bar.main(test.scala)

Why is the line number 13 and not 14 or 12?

[som-snytt]

Loading any arg persuades it to emit a line, apparently. By whole tree, I meant the this.x.y application. I confirmed that javac does the obvious thing (complete line info).