Don't cache given aliases to this

odersky · odersky · commit 0f33d4d93ad8 · 2020-08-19T17:02:29.000+02:00
A given alias

   given Foo = this

does not need to be cached in a lazy val since `this` is an immutable reference.
diff --git a/compiler/src/dotty/tools/dotc/transform/CacheAliasImplicits.scala b/compiler/src/dotty/tools/dotc/transform/CacheAliasImplicits.scala
@@ -56,6 +56,7 @@ class CacheAliasImplicits extends MiniPhase with IdentityDenotTransformer { this
             if rhsTpe.isStable => false
             case rhsTpe @ TermRef(pre: ThisType, _)
             if rhsTpe.isStable && pre.cls == sym.owner.enclosingClass => false
+            case rhsTpe: ThisType => false
             case _ => true
           }
         case _ => false

Original file line number	Diff line number	Diff line change
`@@ -56,6 +56,7 @@ class CacheAliasImplicits extends MiniPhase with IdentityDenotTransformer { this`
`56`	`56`	`if rhsTpe.isStable => false`
`57`	`57`	`case rhsTpe @ TermRef(pre: ThisType, _)`
`58`	`58`	`if rhsTpe.isStable && pre.cls == sym.owner.enclosingClass => false`
	`59`	`+ case rhsTpe: ThisType => false`
`59`	`60`	`case _ => true`
`60`	`61`	`}`
`61`	`62`	`case _ => false`