diff options
author | Martin Odersky <odersky@gmail.com> | 2017-02-02 14:55:06 +1100 |
---|---|---|
committer | Martin Odersky <odersky@gmail.com> | 2017-02-08 22:20:26 +1100 |
commit | ba66bd47f08e1adf3d44f578452a5113948cb988 (patch) | |
tree | c1f4d9134ffd94f7d750ddbea1798a09bd89fda2 /compiler/src | |
parent | b77c24cde0caa59472108a068b4d802606ad5d1b (diff) | |
download | dotty-ba66bd47f08e1adf3d44f578452a5113948cb988.tar.gz dotty-ba66bd47f08e1adf3d44f578452a5113948cb988.tar.bz2 dotty-ba66bd47f08e1adf3d44f578452a5113948cb988.zip |
Fix #1501 - Check trait inheritance condition
We need to check a coherence condition between the superclass
of a trait and the superclass of an inheriting class or trait.
Diffstat (limited to 'compiler/src')
-rw-r--r-- | compiler/src/dotty/tools/dotc/typer/Checking.scala | 12 | ||||
-rw-r--r-- | compiler/src/dotty/tools/dotc/typer/Typer.scala | 2 |
2 files changed, 13 insertions, 1 deletions
diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala index ca62ed0a9..f4625cbfd 100644 --- a/compiler/src/dotty/tools/dotc/typer/Checking.scala +++ b/compiler/src/dotty/tools/dotc/typer/Checking.scala @@ -448,7 +448,6 @@ object Checking { } stats.foreach(checkValueClassMember) } - } } @@ -601,6 +600,16 @@ trait Checking { /** Verify classes extending AnyVal meet the requirements */ def checkDerivedValueClass(clazz: Symbol, stats: List[Tree])(implicit ctx: Context) = Checking.checkDerivedValueClass(clazz, stats) + + /** 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`. + */ + def checkTraitInheritance(parent: Symbol, cls: ClassSymbol, pos: Position)(implicit ctx: Context): Unit = + parent match { + case parent: ClassSymbol if parent.is(Trait) && !cls.superClass.derivesFrom(parent.superClass) => + ctx.error(em"illegal trait inheritance: super${cls.superClass} does not derive from $parent's super${parent.superClass}", pos) + case _ => + } } trait NoChecking extends Checking { @@ -617,4 +626,5 @@ trait NoChecking extends Checking { override def checkSimpleKinded(tpt: Tree)(implicit ctx: Context): Tree = tpt override def checkNotSingleton(tpt: Tree, where: String)(implicit ctx: Context): Tree = tpt override def checkDerivedValueClass(clazz: Symbol, stats: List[Tree])(implicit ctx: Context) = () + override def checkTraitInheritance(parentSym: Symbol, cls: ClassSymbol, pos: Position)(implicit ctx: Context) = () } diff --git a/compiler/src/dotty/tools/dotc/typer/Typer.scala b/compiler/src/dotty/tools/dotc/typer/Typer.scala index 18ae790b7..4f9d96c70 100644 --- a/compiler/src/dotty/tools/dotc/typer/Typer.scala +++ b/compiler/src/dotty/tools/dotc/typer/Typer.scala @@ -1288,6 +1288,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit if (tree.isType) { val result = typedType(tree)(superCtx) val psym = result.tpe.typeSymbol + checkTraitInheritance(psym, cls, tree.pos) if (psym.is(Trait) && !cls.is(Trait) && !cls.superClass.isSubClass(psym)) maybeCall(result, psym, psym.primaryConstructor.info) else @@ -1295,6 +1296,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit } else { val result = typedExpr(tree)(superCtx) + checkTraitInheritance(result.symbol, cls, tree.pos) checkParentCall(result, cls) result } |