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-rw-r--r--src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala63
-rw-r--r--tests/disabled/pos-scala2/i1059.scala (renamed from tests/pos-scala2/i1059.scala)0
-rw-r--r--tests/disabled/pos/t3480.scala (renamed from tests/pos/t3480.scala)0
-rw-r--r--tests/neg/i1255.scala6
-rw-r--r--tests/pos/t1168.scala2
-rw-r--r--tests/run/t6637.scala3
6 files changed, 44 insertions, 30 deletions
diff --git a/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala b/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala
index 8b1baa11a..14c3dea71 100644
--- a/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala
+++ b/src/dotty/tools/dotc/transform/IsInstanceOfEvaluator.scala
@@ -5,7 +5,7 @@ import dotty.tools.dotc.util.Positions._
import TreeTransforms.{MiniPhaseTransform, TransformerInfo}
import core._
import Contexts.Context, Types._, Constants._, Decorators._, Symbols._
-import TypeUtils._, TypeErasure._
+import TypeUtils._, TypeErasure._, Flags._
/** Implements partial evaluation of `sc.isInstanceOf[Sel]` according to:
@@ -25,10 +25,11 @@ import TypeUtils._, TypeErasure._
*
* 1. evalTypeApply will establish the matrix and choose the appropriate
* handling for the case:
- * 2. a) handleStaticallyKnown
- * b) falseIfUnrelated with `scrutinee <:< selector`
- * c) handleFalseUnrelated
- * d) leave as is (aka `happens`)
+ * 2. a) Sel/sc is a value class or scrutinee is `Any`
+ * b) handleStaticallyKnown
+ * c) falseIfUnrelated with `scrutinee <:< selector`
+ * d) handleFalseUnrelated
+ * e) leave as is (aka `happens`)
* 3. Rewrite according to step taken in `2`
*/
class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer =>
@@ -43,43 +44,43 @@ class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer =>
* the correct warnings, or an error if statically known to be false in
* match
*/
- def handleStaticallyKnown(tree: Select, scrutinee: Type, selector: Type, inMatch: Boolean, pos: Position): Tree = {
+ def handleStaticallyKnown(select: Select, scrutinee: Type, selector: Type, inMatch: Boolean, pos: Position): Tree = {
val scrutineeSubSelector = scrutinee <:< selector
if (!scrutineeSubSelector && inMatch) {
ctx.error(
s"this case is unreachable due to `${selector.show}` not being a subclass of `${scrutinee.show}`",
Position(pos.start - 5, pos.end - 5)
)
- rewrite(tree, to = false)
+ rewrite(select, to = false)
} else if (!scrutineeSubSelector && !inMatch) {
ctx.warning(
s"this will always yield false since `${scrutinee.show}` is not a subclass of `${selector.show}` (will be optimized away)",
pos
)
- rewrite(tree, to = false)
+ rewrite(select, to = false)
} else if (scrutineeSubSelector && !inMatch) {
ctx.warning(
s"this will always yield true if the scrutinee is non-null, since `${scrutinee.show}` is a subclass of `${selector.show}` (will be optimized away)",
pos
)
- rewrite(tree, to = true)
- } else /* if (scrutineeSubSelector && inMatch) */ rewrite(tree, to = true)
+ rewrite(select, to = true)
+ } else /* if (scrutineeSubSelector && inMatch) */ rewrite(select, to = true)
}
/** Rewrites cases with unrelated types */
- def handleFalseUnrelated(tree: Select, scrutinee: Type, selector: Type, inMatch: Boolean) =
+ def handleFalseUnrelated(select: Select, scrutinee: Type, selector: Type, inMatch: Boolean) =
if (inMatch) {
ctx.error(
s"will never match since `${selector.show}` is not a subclass of `${scrutinee.show}`",
- Position(tree.pos.start - 5, tree.pos.end - 5)
+ Position(select.pos.start - 5, select.pos.end - 5)
)
- rewrite(tree, to = false)
+ rewrite(select, to = false)
} else {
ctx.warning(
s"will always yield false since `${scrutinee.show}` is not a subclass of `${selector.show}`",
- tree.pos
+ select.pos
)
- rewrite(tree, to = false)
+ rewrite(select, to = false)
}
/** Rewrites the select to a boolean if `to` is false or if the qualifier
@@ -106,25 +107,30 @@ class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer =>
val scrutinee = erasure(s.qualifier.tpe.widen)
val selector = erasure(tree.args.head.tpe.widen)
- val scTrait = scrutinee.typeSymbol is Flags.Trait
+ val scTrait = scrutinee.typeSymbol is Trait
val scClass =
scrutinee.typeSymbol.isClass &&
- !(scrutinee.typeSymbol is Flags.Trait) &&
- !(scrutinee.typeSymbol is Flags.Module)
+ !(scrutinee.typeSymbol is Trait) &&
+ !(scrutinee.typeSymbol is Module)
- val scClassNonFinal = scClass && !scrutinee.typeSymbol.is(Flags.Final)
- val scFinalClass = scClass && (scrutinee.typeSymbol is Flags.Final)
+ val scClassNonFinal = scClass && !(scrutinee.typeSymbol is Final)
+ val scFinalClass = scClass && (scrutinee.typeSymbol is Final)
- val selTrait = selector.typeSymbol is Flags.Trait
+ val selTrait = selector.typeSymbol is Trait
val selClass =
selector.typeSymbol.isClass &&
- !(selector.typeSymbol is Flags.Trait) &&
- !(selector.typeSymbol is Flags.Module)
+ !(selector.typeSymbol is Trait) &&
+ !(selector.typeSymbol is Module)
- val selClassNonFinal = scClass && !(selector.typeSymbol is Flags.Final)
- val selFinalClass = scClass && (selector.typeSymbol is Flags.Final)
+ val selClassNonFinal = scClass && !(selector.typeSymbol is Final)
+ val selFinalClass = scClass && (selector.typeSymbol is Final)
// Cases ---------------------------------
+ val valueClassesOrAny =
+ ValueClasses.isDerivedValueClass(scrutinee.typeSymbol) ||
+ ValueClasses.isDerivedValueClass(selector.typeSymbol) ||
+ scrutinee == defn.ObjectType
+
val knownStatically = scFinalClass
val falseIfUnrelated =
@@ -137,13 +143,16 @@ class IsInstanceOfEvaluator extends MiniPhaseTransform { thisTransformer =>
(scTrait && selClassNonFinal) ||
(scTrait && selTrait)
- val inMatch = s.qualifier.symbol is Flags.Case
+ val inMatch = s.qualifier.symbol is Case
- if (knownStatically)
+ if (valueClassesOrAny) tree
+ else if (knownStatically)
handleStaticallyKnown(s, scrutinee, selector, inMatch, tree.pos)
else if (falseIfUnrelated && scrutinee <:< selector)
+ // scrutinee is a subtype of the selector, safe to rewrite
rewrite(s, to = true)
else if (falseIfUnrelated && !(selector <:< scrutinee))
+ // selector and scrutinee are unrelated
handleFalseUnrelated(s, scrutinee, selector, inMatch)
else if (happens) tree
else tree
diff --git a/tests/pos-scala2/i1059.scala b/tests/disabled/pos-scala2/i1059.scala
index cd23e1916..cd23e1916 100644
--- a/tests/pos-scala2/i1059.scala
+++ b/tests/disabled/pos-scala2/i1059.scala
diff --git a/tests/pos/t3480.scala b/tests/disabled/pos/t3480.scala
index ba2e1a4b8..ba2e1a4b8 100644
--- a/tests/pos/t3480.scala
+++ b/tests/disabled/pos/t3480.scala
diff --git a/tests/neg/i1255.scala b/tests/neg/i1255.scala
new file mode 100644
index 000000000..3bb7e8f25
--- /dev/null
+++ b/tests/neg/i1255.scala
@@ -0,0 +1,6 @@
+object Test {
+ def foo(x: Option[Int]) = x match {
+ case Some(_: Double) => true // error
+ case None => true
+ }
+}
diff --git a/tests/pos/t1168.scala b/tests/pos/t1168.scala
index f43436812..08f1b5cd9 100644
--- a/tests/pos/t1168.scala
+++ b/tests/pos/t1168.scala
@@ -1,6 +1,6 @@
object Test extends App {
- trait SpecialException {}
+ trait SpecialException extends Throwable {}
try {
throw new Exception
diff --git a/tests/run/t6637.scala b/tests/run/t6637.scala
index 7f9c3cd61..052e7f5d6 100644
--- a/tests/run/t6637.scala
+++ b/tests/run/t6637.scala
@@ -1,7 +1,6 @@
-
object Test extends dotty.runtime.LegacyApp {
try {
- class A ; class B ; List().head.isInstanceOf[A with B]
+ List().head
} catch {
case _ :java.util.NoSuchElementException => println("ok")
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-06 22:12:22 +0000