generated.nim

# nim check -d=nimDumpAsync input.nim
proc foo(): Future[void] =
  var retFuture259001 = newFuture[void]("foo")
  iterator fooIter259002(): FutureBase {.closure.} =
    echo "before await"
    var future259003 = newFuture[void]()
    yield future259003
    if future259003.failed:
      setCurrentException(future259003.error)
      if future259003.error of Exception:
        echo "Exception"
      elif true:
        echo "except"
      elif true:
        echo "finally"
      elif true:
        raise future259003.error
      setCurrentException(nil)
    else:
      try:
        future259003.read
        echo "after await"
      except Exception:
        echo "Exception"
      except:
        echo "except"
      finally:
        echo "finally"
    complete(retFuture259001)

  var nameIterVar259006 = fooIter259002
  proc foo_continue259004() {.closure.} =
    try:
      if notnameIterVar259006.finished:
        var next259008 = nameIterVar259006()
        if next259008 ==
            nil:
          if notretFuture259001.finished:
            let msg259010 = "Async procedure ($1) yielded `nil`, are you await\'ing a " &
                "`nil` Future?"
            raise newException(AssertionError, msg259010 % "foo")
        else:
          {.gcsafe.}:
            {.push, hint[ConvFromXtoItselfNotNeeded]: off.}
            next259008.callback = (proc () {.closure, gcsafe.})(foo_continue259004)
            {.pop.}
    except:
      if retFuture259001.finished:
        raise
      else:
        retFuture259001.fail(getCurrentException())

  foo_continue259004()
  return retFuture259001

input.nim

import asyncdispatch

proc foo(): Future[void] {.async.} =
  try:
    echo "before await"
    await newFuture[void]()
    echo "after await"
  except Exception:
    echo "Exception"
  except:
    echo "except"
  finally:
    echo "finally"