Handle local classes: params are abstracted by types

To avoid complicating domains with an environment in Instance,
we just abstract parameters by their types inside local classes.

Author: liufengyun

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

@@ -94,13 +94,9 @@ class Objects {
       params.zip(args).toMap
 
     extension (env: Env)
-      def lookup(sym: Symbol)(using Context): Value =
-        if sym.info <:< defn.StringType
-           || sym.info.classSymbol.isPrimitiveValueClass
-        then
-          Bottom
-        else
-          env(sym)
+      def lookup(sym: Symbol)(using Context): Value = env(sym)
+
+      def getOrElse(sym: Symbol, default: Value)(using Context): Value = env.getOrElse(sym, default)
 
       def union(other: Env): Env = env ++ other
   }
@@ -311,14 +307,14 @@ class Objects {
       }
 
     def call(meth: Symbol, args: List[Value], superType: Type, source: Tree, needResolve: Boolean = true): Contextual[Result] =
-      val isLocal = meth.owner.isClass
       value match {
         case Bottom  =>
           Result(Bottom, Errors.empty)
 
         case TypeAbs(tp) =>
           if meth.isEffectivelyFinal then
             if meth.hasSource then
+              val isLocal = meth.owner.isClass
               val ddef = meth.defTree.asInstanceOf[DefDef]
               val env2 = Env(ddef, args)
               use(if isLocal then env.union(env2) else env2) {
@@ -333,6 +329,7 @@ class Objects {
             Result(Bottom, error :: Nil)
 
         case ClassAbs(klass) =>
+          val isLocal = meth.owner.isClass
           val target =
             if !needResolve then
               meth
@@ -359,6 +356,7 @@ class Objects {
             value.select(target, source, needResolve = false)
 
         case addr: Addr =>
+          val isLocal = meth.owner.isClass
           val target =
             if !needResolve then
               meth
@@ -717,8 +715,7 @@ class Objects {
         // - look up parameters from environment
         // - evaluate the rhs of the local definition for val definitions: they are already cached
         val sym = tmref.symbol
-        if sym.is(Flags.Param) then Result(env.lookup(sym), Nil)
-        else if sym.info <:< defn.StringType || sym.info.classSymbol.isPrimitiveValueClass then Result(Bottom, Nil)
+        if sym.is(Flags.Param) then Result(env.getOrElse(sym, TypeAbs(sym.info)), Nil)
         else if sym.is(Flags.Mutable) then Result(TypeAbs(sym.info), Nil)
         else if sym.is(Flags.Package) then Result(Bottom, Nil)
         else if sym.hasSource then