diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala b/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala index 56ed0ee16c..8b62409076 100644 --- a/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala +++ b/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala @@ -40,9 +40,10 @@ abstract class ConstantFolder { if ((x ne null) && x.tag != UnitTag) tree setType ConstantType(x) else tree } catch { - case _: ArithmeticException => tree // the code will crash at runtime, - // but that is better than the - // compiler itself crashing + case e: ArithmeticException => + if (settings.warnConstant) + warning(tree.pos, s"Evaluation of a constant expression results in an arithmetic error: ${e.getMessage}") + tree } private def foldUnop(op: Name, x: Constant): Constant = (op, x.tag) match { @@ -75,7 +76,7 @@ abstract class ConstantFolder { case nme.AND => Constant(x.booleanValue & y.booleanValue) case nme.EQ => Constant(x.booleanValue == y.booleanValue) case nme.NE => Constant(x.booleanValue != y.booleanValue) - case _ => null + case _ => null } private def foldSubrangeOp(op: Name, x: Constant, y: Constant): Constant = op match { case nme.OR => Constant(x.intValue | y.intValue) @@ -95,14 +96,20 @@ abstract class ConstantFolder { case nme.MUL => Constant(x.intValue * y.intValue) case nme.DIV => Constant(x.intValue / y.intValue) case nme.MOD => Constant(x.intValue % y.intValue) - case _ => null + case _ => null } private def foldLongOp(op: Name, x: Constant, y: Constant): Constant = op match { case nme.OR => Constant(x.longValue | y.longValue) case nme.XOR => Constant(x.longValue ^ y.longValue) case nme.AND => Constant(x.longValue & y.longValue) - case nme.LSL => Constant(x.longValue << y.longValue) + case nme.LSL if x.tag <= IntTag + => Constant(x.intValue << y.longValue) + case nme.LSL => Constant(x.longValue << y.longValue) + case nme.LSR if x.tag <= IntTag + => Constant(x.intValue >>> y.longValue) case nme.LSR => Constant(x.longValue >>> y.longValue) + case nme.ASR if x.tag <= IntTag + => Constant(x.intValue >> y.longValue) case nme.ASR => Constant(x.longValue >> y.longValue) case nme.EQ => Constant(x.longValue == y.longValue) case nme.NE => Constant(x.longValue != y.longValue) @@ -115,7 +122,7 @@ abstract class ConstantFolder { case nme.MUL => Constant(x.longValue * y.longValue) case nme.DIV => Constant(x.longValue / y.longValue) case nme.MOD => Constant(x.longValue % y.longValue) - case _ => null + case _ => null } private def foldFloatOp(op: Name, x: Constant, y: Constant): Constant = op match { case nme.EQ => Constant(x.floatValue == y.floatValue) @@ -129,7 +136,7 @@ abstract class ConstantFolder { case nme.MUL => Constant(x.floatValue * y.floatValue) case nme.DIV => Constant(x.floatValue / y.floatValue) case nme.MOD => Constant(x.floatValue % y.floatValue) - case _ => null + case _ => null } private def foldDoubleOp(op: Name, x: Constant, y: Constant): Constant = op match { case nme.EQ => Constant(x.doubleValue == y.doubleValue) @@ -143,7 +150,7 @@ abstract class ConstantFolder { case nme.MUL => Constant(x.doubleValue * y.doubleValue) case nme.DIV => Constant(x.doubleValue / y.doubleValue) case nme.MOD => Constant(x.doubleValue % y.doubleValue) - case _ => null + case _ => null } private def foldBinop(op: Name, x: Constant, y: Constant): Constant = { @@ -152,7 +159,7 @@ abstract class ConstantFolder { else if (x.isNumeric && y.isNumeric) math.max(x.tag, y.tag) else NoTag - try optag match { + optag match { case BooleanTag => foldBooleanOp(op, x, y) case ByteTag | ShortTag | CharTag | IntTag => foldSubrangeOp(op, x, y) case LongTag => foldLongOp(op, x, y) @@ -161,8 +168,5 @@ abstract class ConstantFolder { case StringTag if op == nme.ADD => Constant(x.stringValue + y.stringValue) case _ => null } - catch { - case ex: ArithmeticException => null - } } } |