diff options
| author | Paul Phillips <paulp@improving.org> | 2012-01-31 08:21:34 -0800 |
|---|---|---|
| committer | Paul Phillips <paulp@improving.org> | 2012-01-31 08:51:42 -0800 |
| commit | 147e9eaf3814738f339b020e701a160ba2f68b60 (patch) | |
| tree | e76a078289a446c69e5c6f952e71e75033553ae6 /src/compiler/scala/tools/nsc/typechecker/RefChecks.scala | |
| parent | 263aa2ead1f599f48b218027eb9550745fef43f1 (diff) | |
| download | scala-147e9eaf3814738f339b020e701a160ba2f68b60.tar.gz scala-147e9eaf3814738f339b020e701a160ba2f68b60.tar.bz2 scala-147e9eaf3814738f339b020e701a160ba2f68b60.zip | |
Improved warning for insensible comparisons.
Utilize knowledge of case class synthetic equals to rule out
some comparisons statically. Closes SI-5426.
Diffstat (limited to 'src/compiler/scala/tools/nsc/typechecker/RefChecks.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/RefChecks.scala | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala index a99d09173e..a6c2f75d5e 100644 --- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala +++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala @@ -1034,10 +1034,10 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R /** Symbols which limit the warnings we can issue since they may be value types */ val isMaybeValue = Set(AnyClass, AnyRefClass, AnyValClass, ObjectClass, ComparableClass, JavaSerializableClass) - // Whether def equals(other: Any) is overridden - def isUsingDefaultEquals = { + // Whether def equals(other: Any) is overridden or synthetic + def isUsingWarnableEquals = { val m = receiver.info.member(nme.equals_) - (m == Object_equals) || (m == Any_equals) + (m == Object_equals) || (m == Any_equals) || (m.isSynthetic && m.owner.isCase) } // Whether this == or != is one of those defined in Any/AnyRef or an overload from elsewhere. def isUsingDefaultScalaOp = { @@ -1045,7 +1045,10 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R (s == Object_==) || (s == Object_!=) || (s == Any_==) || (s == Any_!=) } // Whether the operands+operator represent a warnable combo (assuming anyrefs) - def isWarnable = isReferenceOp || (isUsingDefaultEquals && isUsingDefaultScalaOp) + // Looking for comparisons performed with ==/!= in combination with either an + // equals method inherited from Object or a case class synthetic equals (for + // which we know the logic.) + def isWarnable = isReferenceOp || (isUsingDefaultScalaOp && isUsingWarnableEquals) def isEitherNullable = (NullClass.tpe <:< receiver.info) || (NullClass.tpe <:< actual.info) def isBoolean(s: Symbol) = unboxedValueClass(s) == BooleanClass def isUnit(s: Symbol) = unboxedValueClass(s) == UnitClass |