Pattern matcher does not generate ValDefs for defined pattern bound variables

[odersky]

When compiling pos/functions1.scala I observe the following code snippet

  val x33: String => String = {
    def $anonfun(x22: String): String = {
      case val selector11: String = x22
      {
        def case11(): String = {
          def case21(): String = {
            def matchFail11(): String = throw new MatchError(selector11)
            {
              x34
            }
          }
          if "abc".equals(selector11) then {
            val x21: String = selector11
            {
              ""
            }
          } else case21()
        }
        case11()
      }
    }
    closure($anonfun)
  }

You need to compile against the latest commit with the changed functions1.scala or else compile with -uniqid to observe the effect: In both cases, the definition of the pattern bound variable x34 is missing.

Detected when trying to lambda-lift this code.

[DarkDimius]

@odersky can you please give a link to changed funtions1.scala?

[DarkDimius]

I was able to reproduce. Fix upcomming.

[DarkDimius]

There was an optimization not applicable to dotty left in Pattern Matcher.
In scalac SubstOnlyTreeMakers aren't generating code, and an optimization was included to short-circuit them.
Why this is no longer applicable is explained in commit.

[DarkDimius]

Fixed in #189