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author | Martin Odersky <odersky@gmail.com> | 2016-07-21 14:51:16 +0200 |
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committer | Martin Odersky <odersky@gmail.com> | 2016-07-21 17:42:53 +0200 |
commit | c37185d3307e2b02e25e888fd44d5e8bba95aa1d (patch) | |
tree | b0ec5f8198a559abb1cf83f68a8bed3ad318a4a4 | |
parent | eaffc785be1e42c3a44ce149dfb8cabb6681d7c6 (diff) | |
download | dotty-c37185d3307e2b02e25e888fd44d5e8bba95aa1d.tar.gz dotty-c37185d3307e2b02e25e888fd44d5e8bba95aa1d.tar.bz2 dotty-c37185d3307e2b02e25e888fd44d5e8bba95aa1d.zip |
Fix #1401: Make sure all refs are forwarded
Faced with recursive dependencies through self types, we might have
to apply `normalizeToClassRefs` to a class P with a parent that is not
yet initialized (witnessed by P's parents being Nil). In that case
we should still execute forwardRefs on P, but we have to
wait in a suspension until P is initialized.
This avoids the problem raised in #1401. I am still not quite sure
why forwardRefs is needed, but it seems that asSeenFrom alone is not
enough to track the dependencies in this case.
-rw-r--r-- | src/dotty/tools/dotc/core/TypeOps.scala | 22 | ||||
-rw-r--r-- | src/dotty/tools/dotc/core/Types.scala | 13 | ||||
-rw-r--r-- | src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala | 2 | ||||
-rw-r--r-- | src/dotty/tools/dotc/typer/Namer.scala | 5 | ||||
-rw-r--r-- | test/dotc/scala-collections.whitelist | 2 | ||||
-rw-r--r-- | tests/pos/i1401.scala | 25 |
6 files changed, 59 insertions, 10 deletions
diff --git a/src/dotty/tools/dotc/core/TypeOps.scala b/src/dotty/tools/dotc/core/TypeOps.scala index 10b0f5615..9433cb882 100644 --- a/src/dotty/tools/dotc/core/TypeOps.scala +++ b/src/dotty/tools/dotc/core/TypeOps.scala @@ -361,13 +361,23 @@ trait TypeOps { this: Context => // TODO: Make standalone object. * to the current scope, provided (1) variances of both aliases are the same, and * (2) X is not yet defined in current scope. This "short-circuiting" prevents * long chains of aliases which would have to be traversed in type comparers. + * + * Note: Test i1401.scala shows that `forwardRefs` is also necessary + * for typechecking in the case where self types refer to type parameters + * that are upper-bounded by subclass instances. */ def forwardRefs(from: Symbol, to: Type, prefs: List[TypeRef]) = to match { case to @ TypeBounds(lo1, hi1) if lo1 eq hi1 => - for (pref <- prefs) - for (argSym <- pref.decls) - if (argSym is BaseTypeArg) - forwardRef(argSym, from, to, cls, decls) + for (pref <- prefs) { + def forward(): Unit = + for (argSym <- pref.decls) + if (argSym is BaseTypeArg) + forwardRef(argSym, from, to, cls, decls) + pref.info match { + case info: TempClassInfo => info.suspensions = (() => forward()) :: info.suspensions // !!! dotty deviation `forward` alone does not eta expand + case _ => forward() + } + } case _ => } @@ -419,9 +429,9 @@ trait TypeOps { this: Context => // TODO: Make standalone object. s"redefinition of ${decls.lookup(name).debugString} in ${cls.showLocated}") enterArgBinding(formals(name), refinedInfo, cls, decls) } - // Forward definitions in super classes that have one of the refined paramters + // Forward definitions in super classes that have one of the refined parameters // as aliases directly to the refined info. - // Note that this cannot be fused bwith the previous loop because we now + // Note that this cannot be fused with the previous loop because we now // assume that all arguments have been entered in `decls`. refinements foreachBinding { (name, refinedInfo) => forwardRefs(formals(name), refinedInfo, parentRefs) diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala index 11da27265..8019750bf 100644 --- a/src/dotty/tools/dotc/core/Types.scala +++ b/src/dotty/tools/dotc/core/Types.scala @@ -3043,9 +3043,20 @@ object Types { override def toString = s"ClassInfo($prefix, $cls)" } - final class CachedClassInfo(prefix: Type, cls: ClassSymbol, classParents: List[TypeRef], decls: Scope, selfInfo: DotClass) + class CachedClassInfo(prefix: Type, cls: ClassSymbol, classParents: List[TypeRef], decls: Scope, selfInfo: DotClass) extends ClassInfo(prefix, cls, classParents, decls, selfInfo) + /** A class for temporary class infos where `parents` are not yet known. */ + final class TempClassInfo(prefix: Type, cls: ClassSymbol, decls: Scope, selfInfo: DotClass) + extends CachedClassInfo(prefix, cls, Nil, decls, selfInfo) { + + /** A list of actions that were because they rely on the class info of `cls` to + * be no longer temporary. These actions will be performed once `cls` gets a real + * ClassInfo. + */ + var suspensions: List[() => Unit] = Nil + } + object ClassInfo { def apply(prefix: Type, cls: ClassSymbol, classParents: List[TypeRef], decls: Scope, selfInfo: DotClass = NoType)(implicit ctx: Context) = unique(new CachedClassInfo(prefix, cls, classParents, decls, selfInfo)) diff --git a/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala b/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala index 3dbeb4040..14747619a 100644 --- a/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala +++ b/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala @@ -106,7 +106,7 @@ object Scala2Unpickler { // `denot.sourceModule.exists` provision i859.scala crashes in the backend. denot.owner.thisType select denot.sourceModule else selfInfo - denot.info = ClassInfo(denot.owner.thisType, denot.classSymbol, Nil, decls, ost) // first rough info to avoid CyclicReferences + denot.info = new TempClassInfo(denot.owner.thisType, denot.classSymbol, decls, ost) // first rough info to avoid CyclicReferences var parentRefs = ctx.normalizeToClassRefs(parents, cls, decls) if (parentRefs.isEmpty) parentRefs = defn.ObjectType :: Nil for (tparam <- tparams) { diff --git a/src/dotty/tools/dotc/typer/Namer.scala b/src/dotty/tools/dotc/typer/Namer.scala index 3b193d2db..20cf09846 100644 --- a/src/dotty/tools/dotc/typer/Namer.scala +++ b/src/dotty/tools/dotc/typer/Namer.scala @@ -688,7 +688,8 @@ class Namer { typer: Typer => else createSymbol(self) // pre-set info, so that parent types can refer to type params - denot.info = ClassInfo(cls.owner.thisType, cls, Nil, decls, selfInfo) + val tempClassInfo = new TempClassInfo(cls.owner.thisType, cls, decls, selfInfo) + denot.info = tempClassInfo // Ensure constructor is completed so that any parameter accessors // which have type trees deriving from its parameters can be @@ -705,6 +706,8 @@ class Namer { typer: Typer => index(rest)(inClassContext(selfInfo)) denot.info = ClassInfo(cls.owner.thisType, cls, parentRefs, decls, selfInfo) + tempClassInfo.suspensions.foreach(_()) + Checking.checkWellFormed(cls) if (isDerivedValueClass(cls)) cls.setFlag(Final) cls.setApplicableFlags( diff --git a/test/dotc/scala-collections.whitelist b/test/dotc/scala-collections.whitelist index 50a3f3479..29db48cf2 100644 --- a/test/dotc/scala-collections.whitelist +++ b/test/dotc/scala-collections.whitelist @@ -83,7 +83,7 @@ ./scala-scala/src/library/scala/collection/immutable/Seq.scala ./scala-scala/src/library/scala/collection/mutable/IndexedSeq.scala ./scala-scala/src/library/scala/collection/mutable/ListBuffer.scala -#./scala-scala/src/library/scala/collection/mutable/BufferLike.scala // works under junit, fails under partest, but can't see more info on the cause +./scala-scala/src/library/scala/collection/mutable/BufferLike.scala ./scala-scala/src/library/scala/collection/mutable/ArrayBuilder.scala diff --git a/tests/pos/i1401.scala b/tests/pos/i1401.scala new file mode 100644 index 000000000..140d78e7f --- /dev/null +++ b/tests/pos/i1401.scala @@ -0,0 +1,25 @@ +package i1401 + +trait Subtractable[A, +Repr <: Subtractable[A, Repr]] { + def -(elem: A): Repr +} + +trait BufferLike[BA, +This <: BufferLike[BA, This] with Buffer[BA]] + extends Subtractable[BA, This] +{ self : This => + + /* Without fix-#1401: + * + error: overriding method - in trait Subtractable of type (elem: A)This & i1401.Buffer[A]; + method - of type (elem: BA)This has incompatible type + def -(elem: BA): This + ^ + one error found + */ + def -(elem: BA): This +} + +trait Buffer[A] extends BufferLike[A, Buffer[A]] + + + |