diff options
| author | Martin Odersky <odersky@gmail.com> | 2017-02-03 10:11:42 +1100 |
|---|---|---|
| committer | Martin Odersky <odersky@gmail.com> | 2017-02-08 22:20:26 +1100 |
| commit | 54cd06526acf1cc45cbf3480ece4885f8853ab18 (patch) | |
| tree | db8d4f927cf76ae73ff29e958fd015150fc99e93 /compiler/src/dotty/tools/dotc/typer/Checking.scala | |
| parent | 0828a5275ace05ac3bcc89c3fbbced389fab7107 (diff) | |
| download | dotty-54cd06526acf1cc45cbf3480ece4885f8853ab18.tar.gz dotty-54cd06526acf1cc45cbf3480ece4885f8853ab18.tar.bz2 dotty-54cd06526acf1cc45cbf3480ece4885f8853ab18.zip | |
Narrow Java exception to inheritance rule
Excepted are only Serializable and Comparable. This follows
scalac's behavior.
Diffstat (limited to 'compiler/src/dotty/tools/dotc/typer/Checking.scala')
| -rw-r--r-- | compiler/src/dotty/tools/dotc/typer/Checking.scala | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala index 74f1311bf..27b0f28ca 100644 --- a/compiler/src/dotty/tools/dotc/typer/Checking.scala +++ b/compiler/src/dotty/tools/dotc/typer/Checking.scala @@ -604,8 +604,9 @@ trait Checking { /** Given a parent `parent` of a class `cls`, if `parent` is a trait check that * the superclass of `cls` derived from the superclass of `parent`. * - * An exception is made if `cls` extends `Any`, and `parent` is a Java class - * that extends `Object`. For instance, we accept code like + * An exception is made if `cls` extends `Any`, and `parent` is `java.io.Serializable` + * or `java.lang.Comparable`. These two classes are treated by Scala as universal + * traits. E.g. the following is OK: * * ... extends Any with java.io.Serializable * @@ -617,7 +618,8 @@ trait Checking { val psuper = parent.superClass val csuper = cls.superClass val ok = csuper.derivesFrom(psuper) || - parent.is(JavaDefined) && csuper == defn.AnyClass && psuper == defn.ObjectClass + parent.is(JavaDefined) && csuper == defn.AnyClass && + (parent == defn.JavaSerializableClass || parent == defn.ComparableClass) if (!ok) ctx.error(em"illegal trait inheritance: super$csuper does not derive from $parent's super$psuper", pos) case _ => |