Tailrec jammed by safer exceptions

Compiler
1 
object TestyFactorial:
  // minimal example
  import scala.annotation.tailrec
  import language.experimental.saferExceptions

  @tailrec
  final def fact(n: Int, acc: Int): Int throws Exception =
    if n < 0 then
      throw new Exception
    else if n == 0 then
      acc
    else
      fact(n - 1, acc * n)

$sbt clean compile
  ...
[error]  |    fact(n - 1, acc * n)
[error]  |    ^^^^^^^^^^^^^^^^^^^^
[error]  |    Cannot rewrite recursive call: it is not in tail position


$head -1 build.sbt 
ThisBuild / scalaVersion := "3.3.1-RC1-bin-20230322-1f574e8-NIGHTLY"
1 Like
2

Thanks for letting us know about the issue! I filed it on GitHub : Tailrec jammed by safer exceptions · Issue #17147 · lampepfl/dotty · GitHub .

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