diff options
Diffstat (limited to 'src/compiler')
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/RefChecks.scala | 65 |
1 files changed, 43 insertions, 22 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala index 806ee480f0..c4b08f6ea2 100644 --- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala +++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala @@ -1059,12 +1059,10 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R // equals. def isUsingWarnableEquals = { val m = receiver.info.member(nme.equals_) - def n = actual.info.member(nme.equals_) - ( (m == Object_equals) - || (m == Any_equals) - || (m.isSynthetic && m.owner.isCase && !n.owner.isCase) - ) + ((m == Object_equals) || (m == Any_equals) || isMethodCaseEquals(m)) } + def isMethodCaseEquals(m: Symbol) = m.isSynthetic && m.owner.isCase + def isCaseEquals = isMethodCaseEquals(receiver.info.member(nme.equals_)) // Whether this == or != is one of those defined in Any/AnyRef or an overload from elsewhere. def isUsingDefaultScalaOp = { val s = fn.symbol @@ -1087,9 +1085,11 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R val msg = alwaysEqual == (name == nme.EQ || name == nme.eq) unit.warning(pos, "comparing "+what+" using `"+name.decode+"' will always yield " + msg) } - def nonSensible(pre: String, alwaysEqual: Boolean) = nonSensibleWarning(pre+"values of types "+typesString, alwaysEqual) + def nonSensiblyEq() = nonSensible("", true) + def nonSensiblyNeq() = nonSensible("", false) + def nonSensiblyNew() = nonSensibleWarning("a fresh object", false) def unrelatedTypes() = { val msg = if (name == nme.EQ || name == nme.eq) @@ -1097,52 +1097,73 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R unit.warning(pos, typesString + " are unrelated: they will most likely " + msg) } - if (nullCount == 2) - nonSensible("", true) // null == null + if (nullCount == 2) // null == null + nonSensiblyEq() else if (nullCount == 1) { if (onSyms(_ exists isPrimitiveValueClass)) // null == 5 - nonSensible("", false) + nonSensiblyNeq() else if (onTrees( _ exists isNew)) // null == new AnyRef - nonSensibleWarning("a fresh object", false) + nonSensiblyNew() } else if (isBoolean(receiver)) { if (!isBoolean(actual) && !isMaybeValue(actual)) // true == 5 - nonSensible("", false) + nonSensiblyNeq() } else if (isUnit(receiver)) { if (isUnit(actual)) // () == () - nonSensible("", true) + nonSensiblyEq() else if (!isUnit(actual) && !isMaybeValue(actual)) // () == "abc" - nonSensible("", false) + nonSensiblyNeq() } else if (isNumeric(receiver)) { if (!isNumeric(actual) && !forMSIL) if (isUnit(actual) || isBoolean(actual) || !isMaybeValue(actual)) // 5 == "abc" - nonSensible("", false) + nonSensiblyNeq() } - else if (isWarnable) { + else if (isWarnable && !isCaseEquals) { if (isNew(qual)) // new X == y - nonSensibleWarning("a fresh object", false) + nonSensiblyNew() else if (isNew(args.head) && (receiver.isEffectivelyFinal || isReferenceOp)) // object X ; X == new Y - nonSensibleWarning("a fresh object", false) + nonSensiblyNew() else if (receiver.isEffectivelyFinal && !(receiver isSubClass actual)) { // object X, Y; X == Y if (isEitherNullable) nonSensible("non-null ", false) else - nonSensible("", false) + nonSensiblyNeq() } } // possibleNumericCount is insufficient or this will warn on e.g. Boolean == j.l.Boolean if (isWarnable && nullCount == 0 && !(isSpecial(receiver) && isSpecial(actual))) { - if (actual isSubClass receiver) () - else if (receiver isSubClass actual) () - // warn only if they have no common supertype below Object - else { + // better to have lubbed and lost + def warnIfLubless(): Unit = { val common = global.lub(List(actual.tpe, receiver.tpe)) if (ObjectClass.tpe <:< common) unrelatedTypes() } + def eitherSubclasses = (actual isSubClass receiver) || (receiver isSubClass actual) + // warn if actual has a case parent that is not same as receiver's; + // if actual is not a case, then warn if no common supertype, as below + if (isCaseEquals) { + def thisCase = receiver.info.member(nme.equals_).owner + actual.info.baseClasses.find(_.isCase) match { + case Some(p) if (p != thisCase) => nonSensible("case class ", false) + case None => + // stronger message on (Some(1) == None) + //if (receiver.isCase && receiver.isEffectivelyFinal && !(receiver isSubClass actual)) nonSensiblyNeq() + //else + // if a class, it must be super to thisCase (and receiver) since not <: thisCase + if (!actual.isTrait && !(receiver isSubClass actual)) nonSensiblyNeq() + else if (!eitherSubclasses) warnIfLubless() + case _ => + } + } + else if (actual isSubClass receiver) () + else if (receiver isSubClass actual) () + // warn only if they have no common supertype below Object + else { + warnIfLubless() + } } case _ => } |