diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/RefChecks.scala | 42 | ||||
| -rw-r--r-- | test/files/neg/abstract-class-2.check | 5 | ||||
| -rw-r--r-- | test/files/neg/abstract-class-2.scala | 14 | ||||
| -rw-r--r-- | test/files/neg/abstract-class-error.check | 5 | ||||
| -rw-r--r-- | test/files/neg/abstract-class-error/J.java | 4 | ||||
| -rw-r--r-- | test/files/neg/abstract-class-error/S.scala | 4 |
6 files changed, 74 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala index 3eb5107870..a23e5d704e 100644 --- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala +++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala @@ -507,6 +507,48 @@ abstract class RefChecks extends InfoTransform { else analyzer.varNotice(member) ) } + else if (underlying.isMethod) { + // If there is a concrete method whose name matches the unimplemented + // abstract method, and a cursory examination of the difference reveals + // something obvious to us, let's make it more obvious to them. + val abstractParams = underlying.tpe.paramTypes + val matchingName = clazz.tpe.nonPrivateMembersAdmitting(VBRIDGE) + val matchingArity = matchingName filter { m => + !m.isDeferred && + (m.name == underlying.name) && + (m.tpe.paramTypes.size == underlying.tpe.paramTypes.size) && + (m.tpe.typeParams.size == underlying.tpe.typeParams.size) + } + + matchingArity match { + // So far so good: only one candidate method + case concrete :: Nil => + val mismatches = abstractParams zip concrete.tpe.paramTypes filterNot { case (x, y) => x =:= y } + mismatches match { + // Only one mismatched parameter: say something useful. + case (pa, pc) :: Nil => + val addendum = + if (pa.typeSymbol == pc.typeSymbol) { + // TODO: what is the optimal way to test for a raw type at this point? + // Compilation has already failed so we shouldn't have to worry overmuch + // about forcing types. + if (underlying.isJavaDefined && pa.typeArgs.isEmpty && pa.typeSymbol.typeParams.nonEmpty) + ". To implement a raw type, use %s[_]".format(pa) + else if (pa.prefix =:= pc.prefix) + ": their type parameters differ" + else + ": their prefixes (i.e. enclosing instances) differ" + } + else "" + + undefined("\n(Note that %s does not match %s%s)".format(pa, pc, addendum)) + case xs => + undefined("") + } + case _ => + undefined("") + } + } else undefined("") } diff --git a/test/files/neg/abstract-class-2.check b/test/files/neg/abstract-class-2.check new file mode 100644 index 0000000000..ca79dd8293 --- /dev/null +++ b/test/files/neg/abstract-class-2.check @@ -0,0 +1,5 @@ +abstract-class-2.scala:11: error: object creation impossible, since method f in trait S2 of type (x: P2.this.p.S1)Int is not defined +(Note that P.this.p.S1 does not match P2.this.S1: their prefixes (i.e. enclosing instances) differ) + object O2 extends S2 { + ^ +one error found diff --git a/test/files/neg/abstract-class-2.scala b/test/files/neg/abstract-class-2.scala new file mode 100644 index 0000000000..19f74f3da6 --- /dev/null +++ b/test/files/neg/abstract-class-2.scala @@ -0,0 +1,14 @@ +class P { + trait S1 + val p = new P + + trait S2 { + def f(x: p.S1): Int + } +} + +class P2 extends P { + object O2 extends S2 { + def f(x: S1) = 5 + } +} diff --git a/test/files/neg/abstract-class-error.check b/test/files/neg/abstract-class-error.check new file mode 100644 index 0000000000..b8a0c6e70b --- /dev/null +++ b/test/files/neg/abstract-class-error.check @@ -0,0 +1,5 @@ +S.scala:1: error: class S needs to be abstract, since method g in class J of type (y: Int,z: java.util.List)Int is not defined +(Note that java.util.List does not match java.util.List[String]. To implement a raw type, use java.util.List[_]) +class S extends J { + ^ +one error found diff --git a/test/files/neg/abstract-class-error/J.java b/test/files/neg/abstract-class-error/J.java new file mode 100644 index 0000000000..5877f5cc5b --- /dev/null +++ b/test/files/neg/abstract-class-error/J.java @@ -0,0 +1,4 @@ +public abstract class J { + public abstract int f(); + public abstract int g(int y, java.util.List z); +}
\ No newline at end of file diff --git a/test/files/neg/abstract-class-error/S.scala b/test/files/neg/abstract-class-error/S.scala new file mode 100644 index 0000000000..67f6d8593e --- /dev/null +++ b/test/files/neg/abstract-class-error/S.scala @@ -0,0 +1,4 @@ +class S extends J { + def f() = 55 + def g(y: Int, z: java.util.List[String]) = 11 +} |