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-rw-r--r--src/dotty/tools/dotc/core/SymDenotations.scala10
-rw-r--r--src/dotty/tools/dotc/core/Symbols.scala8
-rw-r--r--src/dotty/tools/dotc/core/TypeErasure.scala38
-rw-r--r--src/dotty/tools/dotc/transform/Erasure.scala37
-rw-r--r--src/dotty/tools/dotc/transform/TypeTestsCasts.scala2
5 files changed, 68 insertions, 27 deletions
diff --git a/src/dotty/tools/dotc/core/SymDenotations.scala b/src/dotty/tools/dotc/core/SymDenotations.scala
index bcd46810e..14be606a1 100644
--- a/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -1447,10 +1447,16 @@ object SymDenotations {
def inCache(tp: Type) = baseTypeRefCache.containsKey(tp)
- /** Can't cache types containing type variables which are uninstantiated
- * or whose instances can change, depending on typerstate.
+ /** We cannot cache:
+ * - type variables which are uninstantiated or whose instances can
+ * change, depending on typerstate.
+ * - types where the underlying type is an ErasedValueType, because
+ * this underlying type will change after ElimErasedValueType,
+ * and this changes subtyping relations. As a shortcut, we do not
+ * cache ErasedValueType at all.
*/
def isCachable(tp: Type): Boolean = tp match {
+ case _: TypeErasure.ErasedValueType => false
case tp: TypeVar => tp.inst.exists && inCache(tp.inst)
case tp: TypeProxy => inCache(tp.underlying)
case tp: AndOrType => inCache(tp.tp1) && inCache(tp.tp2)
diff --git a/src/dotty/tools/dotc/core/Symbols.scala b/src/dotty/tools/dotc/core/Symbols.scala
index 9f18e723c..2b91efbcd 100644
--- a/src/dotty/tools/dotc/core/Symbols.scala
+++ b/src/dotty/tools/dotc/core/Symbols.scala
@@ -434,14 +434,6 @@ object Symbols {
/** If this symbol satisfies predicate `p` this symbol, otherwise `NoSymbol` */
def filter(p: Symbol => Boolean): Symbol = if (p(this)) this else NoSymbol
- /** Is this symbol a user-defined value class? */
- final def isDerivedValueClass(implicit ctx: Context): Boolean = {
- this.derivesFrom(defn.AnyValClass)(ctx.withPhase(denot.validFor.firstPhaseId))
- // Simulate ValueClasses.isDerivedValueClass
- false // will migrate to ValueClasses.isDerivedValueClass;
- // unsupported value class code will continue to use this stub while it exists
- }
-
/** The current name of this symbol */
final def name(implicit ctx: Context): ThisName = denot.name.asInstanceOf[ThisName]
diff --git a/src/dotty/tools/dotc/core/TypeErasure.scala b/src/dotty/tools/dotc/core/TypeErasure.scala
index 56b50c74a..1ea63465a 100644
--- a/src/dotty/tools/dotc/core/TypeErasure.scala
+++ b/src/dotty/tools/dotc/core/TypeErasure.scala
@@ -5,11 +5,13 @@ package core
import Symbols._, Types._, Contexts._, Flags._, Names._, StdNames._, Decorators._, Flags.JavaDefined
import Uniques.unique
import dotc.transform.ExplicitOuter._
+import dotc.transform.ValueClasses._
import typer.Mode
import util.DotClass
/** Erased types are:
*
+ * ErasedValueType
* TypeRef(prefix is ignored, denot is ClassDenotation)
* TermRef(prefix is ignored, denot is SymDenotation)
* JavaArrayType
@@ -30,8 +32,12 @@ object TypeErasure {
/** A predicate that tests whether a type is a legal erased type. Only asInstanceOf and
* isInstanceOf may have types that do not satisfy the predicate.
+ * ErasedValueType is considered an erased type because it is valid after Erasure (it is
+ * eliminated by ElimErasedValueType).
*/
def isErasedType(tp: Type)(implicit ctx: Context): Boolean = tp match {
+ case _: ErasedValueType =>
+ true
case tp: TypeRef =>
tp.symbol.isClass && tp.symbol != defn.AnyClass
case _: TermRef =>
@@ -283,10 +289,12 @@ class TypeErasure(isJava: Boolean, semiEraseVCs: Boolean, isConstructor: Boolean
* - For any other type, exception.
*/
private def apply(tp: Type)(implicit ctx: Context): Type = tp match {
+ case _: ErasedValueType =>
+ tp
case tp: TypeRef =>
val sym = tp.symbol
if (!sym.isClass) this(tp.info)
- else if (sym.isDerivedValueClass) eraseDerivedValueClassRef(tp)
+ else if (semiEraseVCs && isDerivedValueClass(sym)) eraseDerivedValueClassRef(tp)
else eraseNormalClassRef(tp)
case tp: RefinedType =>
val parent = tp.parent
@@ -295,7 +303,9 @@ class TypeErasure(isJava: Boolean, semiEraseVCs: Boolean, isConstructor: Boolean
case tp: TermRef =>
this(tp.widen)
case tp: ThisType =>
- this(tp.cls.typeRef)
+ def thisTypeErasure(tpToErase: Type) =
+ erasureFn(isJava, semiEraseVCs = false, isConstructor, wildcardOK)(tpToErase)
+ thisTypeErasure(tp.cls.typeRef)
case SuperType(thistpe, supertpe) =>
SuperType(this(thistpe), this(supertpe))
case ExprType(rt) =>
@@ -307,7 +317,8 @@ class TypeErasure(isJava: Boolean, semiEraseVCs: Boolean, isConstructor: Boolean
case OrType(tp1, tp2) =>
ctx.typeComparer.orType(this(tp1), this(tp2), erased = true)
case tp: MethodType =>
- val paramErasure = erasureFn(tp.isJava, semiEraseVCs, isConstructor, wildcardOK)(_)
+ def paramErasure(tpToErase: Type) =
+ erasureFn(tp.isJava, semiEraseVCs, isConstructor, wildcardOK)(tpToErase)
val formals = tp.paramTypes.mapConserve(paramErasure)
eraseResult(tp.resultType) match {
case rt: MethodType =>
@@ -345,9 +356,11 @@ class TypeErasure(isJava: Boolean, semiEraseVCs: Boolean, isConstructor: Boolean
private def eraseArray(tp: RefinedType)(implicit ctx: Context) = {
val defn.ArrayType(elemtp) = tp
+ def arrayErasure(tpToErase: Type) =
+ erasureFn(isJava, semiEraseVCs = false, isConstructor, wildcardOK)(tpToErase)
if (elemtp derivesFrom defn.NullClass) JavaArrayType(defn.ObjectType)
else if (isUnboundedGeneric(elemtp)) defn.ObjectType
- else JavaArrayType(this(elemtp))
+ else JavaArrayType(arrayErasure(elemtp))
}
/** The erasure of a symbol's info. This is different from `apply` in the way `ExprType`s are
@@ -365,8 +378,12 @@ class TypeErasure(isJava: Boolean, semiEraseVCs: Boolean, isConstructor: Boolean
case tp => this(tp)
}
- private def eraseDerivedValueClassRef(tref: TypeRef)(implicit ctx: Context): Type =
- unsupported("eraseDerivedValueClass")
+ private def eraseDerivedValueClassRef(tref: TypeRef)(implicit ctx: Context): Type = {
+ val cls = tref.symbol.asClass
+ val underlying = underlyingOfValueClass(cls)
+ ErasedValueType(cls, erasure(underlying))
+ }
+
private def eraseNormalClassRef(tref: TypeRef)(implicit ctx: Context): Type = {
val cls = tref.symbol.asClass
@@ -378,7 +395,10 @@ class TypeErasure(isJava: Boolean, semiEraseVCs: Boolean, isConstructor: Boolean
case tp: TypeRef =>
val sym = tp.typeSymbol
if (sym eq defn.UnitClass) sym.typeRef
- else if (sym.isDerivedValueClass) eraseNormalClassRef(tp)
+ // For a value class V, "new V(x)" should have type V for type adaptation to work
+ // correctly (see SIP-15 and [[Erasure.Boxing.adaptToType]]), so the return type of a
+ // constructor method should not be semi-erased.
+ else if (isConstructor && isDerivedValueClass(sym)) eraseNormalClassRef(tp)
else this(tp)
case RefinedType(parent, _) if !(parent isRef defn.ArrayClass) =>
eraseResult(parent)
@@ -400,10 +420,12 @@ class TypeErasure(isJava: Boolean, semiEraseVCs: Boolean, isConstructor: Boolean
* Need to ensure correspondence with erasure!
*/
private def sigName(tp: Type)(implicit ctx: Context): TypeName = tp match {
+ case ErasedValueType(_, underlying) =>
+ sigName(underlying)
case tp: TypeRef =>
val sym = tp.symbol
if (!sym.isClass) sigName(tp.info)
- else if (sym.isDerivedValueClass) sigName(eraseDerivedValueClassRef(tp))
+ else if (isDerivedValueClass(sym)) sigName(eraseDerivedValueClassRef(tp))
else normalizeClass(sym.asClass).fullName.asTypeName
case defn.ArrayType(elem) =>
sigName(this(tp))
diff --git a/src/dotty/tools/dotc/transform/Erasure.scala b/src/dotty/tools/dotc/transform/Erasure.scala
index 01f86915d..293059af2 100644
--- a/src/dotty/tools/dotc/transform/Erasure.scala
+++ b/src/dotty/tools/dotc/transform/Erasure.scala
@@ -254,18 +254,39 @@ object Erasure extends TypeTestsCasts{
class Typer extends typer.ReTyper with NoChecking {
import Boxing._
- def erasedType(tree: untpd.Tree)(implicit ctx: Context): Type = tree.typeOpt match {
- case tp: TermRef if tree.isTerm => erasedRef(tp)
- case tp => erasure(tp)
- }
+ def erasedType(tree: untpd.Tree, semiEraseVCs: Boolean = true)(implicit ctx: Context): Type =
+ tree.typeOpt match {
+ case tp: TermRef if tree.isTerm => erasedRef(tp)
+ case tp => erasure(tp, semiEraseVCs)
+ }
- override def promote(tree: untpd.Tree)(implicit ctx: Context): tree.ThisTree[Type] = {
+ def promote(tree: untpd.Tree, semiEraseVCs: Boolean)(implicit ctx: Context): tree.ThisTree[Type] = {
assert(tree.hasType)
- val erased = erasedType(tree)
+ val erased = erasedType(tree, semiEraseVCs)
ctx.log(s"promoting ${tree.show}: ${erased.showWithUnderlying()}")
tree.withType(erased)
}
+ override def promote(tree: untpd.Tree)(implicit ctx: Context): tree.ThisTree[Type] = {
+ promote(tree, true)
+ }
+
+ /** When erasing most TypeTrees we should not semi-erase value types.
+ * This is not the case for [[DefDef#tpt]], [[ValDef#tpt]] and [[Typed#tpt]], they
+ * are handled separately by [[typedDefDef]], [[typedValDef]] and [[typedTyped]].
+ */
+ override def typedTypeTree(tree: untpd.TypeTree, pt: Type)(implicit ctx: Context): TypeTree = {
+ promote(tree, semiEraseVCs = false)
+ }
+
+ /** This override is only needed to semi-erase type ascriptions */
+ override def typedTyped(tree: untpd.Typed, pt: Type)(implicit ctx: Context): Tree = {
+ val Typed(expr, tpt) = tree
+ val tpt1 = promote(tpt)
+ val expr1 = typed(expr, tpt1.tpe)
+ assignType(untpd.cpy.Typed(tree)(expr1, tpt1), tpt1)
+ }
+
override def typedLiteral(tree: untpd.Literal)(implicit ctc: Context): Literal =
if (tree.typeOpt.isRef(defn.UnitClass)) tree.withType(tree.typeOpt)
else super.typedLiteral(tree)
@@ -330,7 +351,7 @@ object Erasure extends TypeTestsCasts{
assert(sym.isConstructor, s"${sym.showLocated}")
select(qual, defn.ObjectClass.info.decl(sym.name).symbol)
}
- else if (qualIsPrimitive && !symIsPrimitive || qual.tpe.isErasedValueType)
+ else if (qualIsPrimitive && !symIsPrimitive || qual.tpe.widenDealias.isErasedValueType)
recur(box(qual))
else if (!qualIsPrimitive && symIsPrimitive)
recur(unbox(qual, sym.owner.typeRef))
@@ -349,7 +370,7 @@ object Erasure extends TypeTestsCasts{
}
override def typedSelectFromTypeTree(tree: untpd.SelectFromTypeTree, pt: Type)(implicit ctx: Context) =
- untpd.Ident(tree.name).withPos(tree.pos).withType(erasedType(tree))
+ untpd.Ident(tree.name).withPos(tree.pos).withType(erasedType(tree, semiEraseVCs = false))
override def typedThis(tree: untpd.This)(implicit ctx: Context): Tree =
if (tree.symbol == ctx.owner.enclosingClass || tree.symbol.isStaticOwner) promote(tree)
diff --git a/src/dotty/tools/dotc/transform/TypeTestsCasts.scala b/src/dotty/tools/dotc/transform/TypeTestsCasts.scala
index 9d827d3e0..b8ba4427c 100644
--- a/src/dotty/tools/dotc/transform/TypeTestsCasts.scala
+++ b/src/dotty/tools/dotc/transform/TypeTestsCasts.scala
@@ -93,7 +93,7 @@ trait TypeTestsCasts {
else
derivedTree(qual, defn.Any_asInstanceOf, argType)
}
- def erasedArg = erasure(tree.args.head.tpe)
+ def erasedArg = erasure(tree.args.head.tpe, semiEraseVCs = false)
if (sym eq defn.Any_isInstanceOf)
transformIsInstanceOf(qual, erasedArg)
else if (sym eq defn.Any_asInstanceOf)
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-19 12:25:45 +0000