Handle local classes properly

Author: liufengyun

compiler/src/dotty/tools/dotc/transform/init/Summarization.scala

@@ -86,8 +86,15 @@ object Summarization {
         val cls = tref.classSymbol.asClass
         // local class may capture, thus we need to track it
         if (tref.prefix == NoPrefix) {
+          val cur = theCtx.owner.lexicallyEnclosingClass.asClass
           val thisRef = ThisRef()(expr)
-          Summary.empty + Warm(cls, thisRef)(expr)
+          val enclosing = cls.owner.lexicallyEnclosingClass.asClass
+          val (pots, effs) = resolveThis(enclosing, thisRef, cur, expr)
+          if pots.isEmpty then (Potentials.empty, effs)
+          else {
+            assert(pots.size == 1)
+            (Warm(cls, pots.head)(expr).toPots, effs)
+          }
         }
         else {
           val (pots, effs) = analyze(tref.prefix, expr)
@@ -323,7 +330,7 @@ object Summarization {
       if (tref.prefix != NoPrefix)
         parentCls -> analyze(tref.prefix, source)(env.withOwner(cls))._1
       else
-        parentCls -> analyze(cls.enclosingClass.thisType, source)(env.withOwner(cls))._1
+        parentCls -> analyze(cls.owner.lexicallyEnclosingClass.thisType, source)(env.withOwner(cls))._1
     }
 
     if (cls.defTree.isEmpty)

tests/init/neg/local-class.scala

@@ -0,0 +1,16 @@
+class Outer {
+  def foo = {
+    class C {
+      val x = n
+    }
+    class D {
+      new C
+    }
+
+    new D
+  }
+
+  foo
+
+  val n = 10 // error
+}

tests/init/pos/explicitOuter.scala

@@ -0,0 +1,10 @@
+class Outer(elem: Int, val next: Outer) {
+  def inner2 = {
+    class C {
+      val x = elem
+    }
+    class D {
+      new C
+    }
+  }
+}