Fix NFInst lookup of inherited names.

- Keep a list of instantiated extends nodes in instantiated classes,
  to make lookup of inherited names work in them.

Compiler/NFFrontEnd/NFClass.mo

@@ -101,6 +101,7 @@ uniontype Class
 
   record INSTANCED_CLASS
     ClassTree.Tree elements;
+    array<InstNode> extendsNodes;
     array<InstNode> components;
     list<Equation> equations;
     list<Equation> initialEquations;
@@ -124,12 +125,6 @@ uniontype Class
 
   type Element = ClassTree.Entry;
 
-  function emptyInstancedClass
-    output Class cls;
-  algorithm
-    cls := INSTANCED_CLASS(ClassTree.new(), listArray({}), {}, {}, {}, {});
-  end emptyInstancedClass;
-
   function initExpandedClass
     input ClassTree.Tree classes;
     output Class cls;
@@ -139,6 +134,7 @@ uniontype Class
 
   function instExpandedClass
     input array<InstNode> components;
+    input array<InstNode> extendsNodes;
     input Class expandedClass;
     output Class instancedClass;
   protected
@@ -159,7 +155,7 @@ uniontype Class
           // instantiated and typed in the correct scope. They should be
           // collected from the extends nodes when flattening the class.
         then
-          INSTANCED_CLASS(expandedClass.elements, components, eqs, ieqs, algs, ialgs);
+          INSTANCED_CLASS(expandedClass.elements, extendsNodes, components, eqs, ieqs, algs, ialgs);
     end match;
   end instExpandedClass;
 
@@ -257,7 +253,10 @@ uniontype Class
     input Class cls;
     output array<InstNode> extendsNodes;
   algorithm
-    EXPANDED_CLASS(extendsNodes = extendsNodes) := cls;
+    extendsNodes := match cls
+      case EXPANDED_CLASS() then cls.extendsNodes;
+      case INSTANCED_CLASS() then cls.extendsNodes;
+    end match;
   end extendsNodes;
 
   function setSections
@@ -273,8 +272,8 @@ uniontype Class
           cls.modifier, equations, initialEquations, algorithms, initialAlgorithms);
 
       case INSTANCED_CLASS()
-        then INSTANCED_CLASS(cls.elements, cls.components, equations,
-          initialEquations, algorithms, initialAlgorithms);
+        then INSTANCED_CLASS(cls.elements, cls.extendsNodes, cls.components,
+          equations, initialEquations, algorithms, initialAlgorithms);
     end match;
   end setSections;
 

Compiler/NFFrontEnd/NFInst.mo

@@ -782,7 +782,7 @@ function instClass
   input InstNode parent;
 protected
   Class c;
-  array<InstNode> components;
+  array<InstNode> components, ext_nodes;
   Modifier type_mod, mod;
   list<Modifier> type_mods, inst_type_mods;
   Binding binding;
@@ -809,10 +809,11 @@ algorithm
         par := if InstNode.isEmpty(parent) then node else parent;
 
         // Instantiate the components.
-        components := instComponents(Class.components(c), par, node);
+        (components, ext_nodes) :=
+          instComponents(Class.components(c), Class.extendsNodes(c), par, node);
 
         // Update the node with the new instance.
-        c := Class.instExpandedClass(components, c);
+        c := Class.instExpandedClass(components, ext_nodes, c);
         node := InstNode.updateClass(c, node);
       then
         ();
@@ -864,13 +865,17 @@ end instClass;
 
 function instComponents
   input array<InstNode> nodes;
+  input array<InstNode> extendsNodes;
   input InstNode parent;
   input InstNode scope;
   output array<InstNode> instNodes;
+  output array<InstNode> instExtendsNodes;
 protected
   InstNode node, ext;
+  Integer ext_idx = 1;
 algorithm
   instNodes := arrayCopy(nodes);
+  instExtendsNodes := arrayCopy(extendsNodes);
 
   for i in 1:arrayLength(nodes) loop
     node := nodes[i];
@@ -881,7 +886,8 @@ algorithm
       ext := Class.resolveExtendsRef(node, InstNode.getClass(scope));
       ext := instClass(ext, Modifier.NOMOD(), InstNode.EMPTY_NODE());
       instNodes[i] := ext;
-      //Class.updateExtends(node, ext, InstNode.getClass(scope));
+      instExtendsNodes[ext_idx] := ext;
+      ext_idx := ext_idx + 1;
     end if;
   end for;
 end instComponents;