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Check path of module prefix for tailrec #23491

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Merged
merged 1 commit into from
Jul 14, 2025
Merged

Check path of module prefix for tailrec #23491

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5 changes: 4 additions & 1 deletion compiler/src/dotty/tools/dotc/transform/TailRec.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -346,7 +346,10 @@ class TailRec extends MiniPhase {
case prefix: This if prefix.symbol == enclosingClass =>
// Avoid assigning `this = this`
assignParamPairs
case prefix if prefix.symbol.is(Module) && prefix.symbol.moduleClass == enclosingClass =>
case prefix
if prefix.symbol.is(Module)
&& prefix.symbol.moduleClass == enclosingClass
&& isPurePath(prefix) =>
// Avoid assigning `this = MyObject`
assignParamPairs
case _ =>
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22 changes: 22 additions & 0 deletions tests/run/i23444.scala
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Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@

import annotation.*

class Path(action: () => Unit, parent: Option[Path]):
object O:
@tailrec
def apply(): Unit =
action()

parent match
case Some(p) =>
p.O.apply()
case None =>

@main def Test: Unit =
var counter = 0
val fun = () => {
counter += 1
if counter > 2 then throw AssertionError("bad loop")
}
val path = Path(fun, Some(Path(fun, None)))
path.O()
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