From 1970a8315ed3b2ff8877dfef2afcee936d59871b Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Mon, 15 Dec 2014 16:21:26 +1000 Subject: SI-9041 Avoid unreported type error with overloading, implicits If `qual.foo(args)` fails to typecheck, we fall back to `ImplicitView(qual).foo(args)`. However, if the original type error stemmed from an overload ambiguity, the tree `Select(qual, 'foo')` holds onto an error symbol. The fall back attempt just returns an `Apply` tree containing the erroneous qualifier, as it does not want to issue cascading type errors. This commit replaces the error symbol with a `NoSymbol`, which triggers the second try typechecking to perform overload resolution again. A more principled fix might be to more pervasively duplicate trees before mutating their types and symbols, that this is beyond the scope of this bug fix. --- test/files/neg/t9041.check | 4 ++++ test/files/neg/t9041.scala | 17 +++++++++++++++++ 2 files changed, 21 insertions(+) create mode 100644 test/files/neg/t9041.check create mode 100644 test/files/neg/t9041.scala (limited to 'test/files/neg') diff --git a/test/files/neg/t9041.check b/test/files/neg/t9041.check new file mode 100644 index 0000000000..669e9434e0 --- /dev/null +++ b/test/files/neg/t9041.check @@ -0,0 +1,4 @@ +t9041.scala:11: error: could not find implicit value for parameter cellSetter: CellSetter[scala.math.BigDecimal] + def setCell(cell: Cell, data: math.BigDecimal) { cell.setCellValue(data) } + ^ +one error found diff --git a/test/files/neg/t9041.scala b/test/files/neg/t9041.scala new file mode 100644 index 0000000000..2bdef0d3ae --- /dev/null +++ b/test/files/neg/t9041.scala @@ -0,0 +1,17 @@ +// False negative test, requires overloading in Cell. + +trait Cell { def setCellValue(i: Int) = () ; def setCellValue(d: Double) = () } + +trait Nope { + def f = { + trait CellSetter[A] { + def setCell(cell: Cell, data: A): Unit + } + implicit val bigDecimalCellSetter = new CellSetter[math.BigDecimal]() { + def setCell(cell: Cell, data: math.BigDecimal) { cell.setCellValue(data) } + } + implicit class RichCell(cell: Cell) { + def setCellValue[A](data: A)(implicit cellSetter: CellSetter[A]) = cellSetter.setCell(cell, data) + } + } +} -- cgit v1.2.3