From 5b9966d077b8fa7af95fa95d7782243892e6ccad Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Tue, 7 Jan 2014 14:01:24 +0100 Subject: SI-8120 Avoid tree sharing when typechecking patmat anon functions When typechecking an empty selector `Match` corresponding to: { case ... => ... }: (A => B) We wrap it in a `Function` and typecheck: (x$1 => x$1 match { case ... => ... }) Local symbols in this expression (representing values bound by the pattern, or just definitions in the body or guard) are then owned by the anonymous function's symbol. However, if we ever discard this `Function` and start anew with the empty selector match, as happens during the fallback to use a view on the receiver in `tryTypedApply`, we found that we had mutated the cases of the original tree, and allowed orphaned local symbols to escape into the compiler pipeline. This commit uses duplicated trees for the the cases in the synthetic `Match` to avoid this problem. `duplicateAndKeepPositions` is used to preserve range positions; without this scala-refactoring PrettyPrinterTest fails. `Tree#duplicate` uses offset positions in the copied tree, which is appropriate when both the original and the copy are going to end up in the final tree. --- test/files/pos/t8120.scala | 9 +++++++++ 1 file changed, 9 insertions(+) create mode 100644 test/files/pos/t8120.scala (limited to 'test/files') diff --git a/test/files/pos/t8120.scala b/test/files/pos/t8120.scala new file mode 100644 index 0000000000..e06f38d5db --- /dev/null +++ b/test/files/pos/t8120.scala @@ -0,0 +1,9 @@ +object A { + class C { + def m(a: Nothing): Int = 0 + } + implicit class RichAny(a: Any) { + def m(a: Any): Int = 0 + } + (new C).m({ case (x, y) => x } : Any => Any) +} -- cgit v1.2.3