Partial fix for bug3535.

- Replaced avl tree implementation in NFSCodeEnv with generic avl tree.
- Fixed NFSCodeDependency to handle duplicate elements better.
- Changed Main.loadLib so that it doesn't remove duplicate top-level
  elements when loading libraries.

Compiler/FFrontEnd/FNode.mo

@@ -339,7 +339,7 @@ protected
   Ref parent;
 algorithm
   FCore.N(n, i, p, c, d) := fromRef(inParentRef);
-  c := RefTree.add(c, inName, inChildRef, RefTree.addConflictReplace);
+  c := RefTree.add(c, inName, inChildRef, printElementConflictError);
   parent := updateRef(inParentRef, FCore.N(n, i, p, c, d));
   FGraphStream.edge(inName, fromRef(parent), fromRef(inChildRef));
 end addChildRef;
@@ -352,10 +352,11 @@ protected
   SourceInfo info1, info2;
   String name;
 algorithm
-  (name, info1) := SCode.elementNameInfo(FNode.getElementFromRef(newRef));
-  info2 := SCode.elementInfo(FNode.getElementFromRef(oldRef));
-  Error.addMultiSourceMessage(Error.DOUBLE_DECLARATION_OF_ELEMENTS, {name}, {info2, info1});
-  fail();
+  dummy := newRef;
+  //(name, info1) := SCode.elementNameInfo(FNode.getElementFromRef(newRef));
+  //info2 := SCode.elementInfo(FNode.getElementFromRef(oldRef));
+  //Error.addMultiSourceMessage(Error.DOUBLE_DECLARATION_OF_ELEMENTS, {name}, {info2, info1});
+  //fail();
 end printElementConflictError;
 
 public function addImportToRef

Compiler/FFrontEnd/FVisit.mo

@@ -701,7 +701,7 @@ algorithm
 
     else
       equation
-        Error.addMessage(Error.INTERNAL_ERROR, {"Env.avlTreeReplace failed"});
+        Error.addMessage(Error.INTERNAL_ERROR, {getInstanceName() + " failed"});
       then fail();
 
   end match;

Compiler/FrontEnd/NFEnvExtends.mo

@@ -136,8 +136,6 @@ protected import Util;
 
 public type Env = NFSCodeEnv.Env;
 
-protected type AvlTree = NFSCodeEnv.AvlTree;
-protected type AvlTreeValue = NFSCodeEnv.AvlTreeValue;
 protected type ClassType = NFSCodeEnv.ClassType;
 protected type Extends = NFSCodeEnv.Extends;
 protected type Frame = NFSCodeEnv.Frame;
@@ -147,6 +145,8 @@ protected type Item = NFSCodeEnv.Item;
 
 protected type ExtendsTableArray = array<ExtendsWrapper>;
 
+import NFSCodeEnv.EnvTree;
+
 public constant String BASECLASS_NOT_FOUND_ERROR = "$1";
 public constant String BASECLASS_INHERITED_ERROR = "$2";
 public constant String BASECLASS_REPLACEABLE_ERROR = "$3";
@@ -244,57 +244,39 @@ protected
   list<SCode.Element> re;
   Option<SCode.Element> cei;
   Env env;
-  AvlTree tree;
+  EnvTree.Tree tree;
 algorithm
   // Qualify the extends in this scope.
   env := qualifyLocalScope(inEnv, inClassType, inExtendsTable);
 
   // Recurse down the tree.
   NFSCodeEnv.FRAME(clsAndVars = tree) :: _ := env;
-  SOME(tree) := qualify3(SOME(tree), env, inExtendsTable);
+  tree := EnvTree.map(tree,
+    function qualify3(inEnv = env, inExtendsTable = inExtendsTable));
   outEnv := NFSCodeEnv.setEnvClsAndVars(tree, env);
 end qualify2;
 
 protected function qualify3
-  input Option<AvlTree> inTree;
+  input String name;
+  input output Item item;
   input Env inEnv;
   input ExtendsTableArray inExtendsTable;
-  output Option<AvlTree> outTree;
 algorithm
-  outTree := match(inTree, inEnv, inExtendsTable)
+  item := match item
     local
-      String name;
       SCode.Element cls;
       Frame cls_env;
       ClassType cls_ty;
-      Integer h;
-      Option<AvlTree> left, right;
       Env env, rest_env;
-      Item item;
-      Option<AvlTreeValue> value;
-
-    // Empty leaf, do nothing.
-    case (NONE(), _, _) then inTree;
 
-    case (SOME(NFSCodeEnv.AVLTREENODE(SOME(NFSCodeEnv.AVLTREEVALUE(
-        name, NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty))), h, left, right)), _, _)
-      equation
-        env = NFSCodeEnv.enterFrame(cls_env, inEnv);
-        cls_env :: rest_env = qualify2(env, cls_ty, inExtendsTable);
-        left = qualify3(left, rest_env, inExtendsTable);
-        right = qualify3(right, rest_env, inExtendsTable);
-        item = NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty);
-        value = SOME(NFSCodeEnv.AVLTREEVALUE(name, item));
+    case NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty)
+      algorithm
+        env := NFSCodeEnv.enterFrame(cls_env, inEnv);
+        cls_env :: rest_env := qualify2(env, cls_ty, inExtendsTable);
       then
-        SOME(NFSCodeEnv.AVLTREENODE(value, h, left, right));
-
-     case (SOME(NFSCodeEnv.AVLTREENODE(value, h, left, right)), _, _)
-       equation
-         left = qualify3(left, inEnv, inExtendsTable);
-         right = qualify3(right, inEnv, inExtendsTable);
-       then
-         SOME(NFSCodeEnv.AVLTREENODE(value, h, left, right));
+        NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty);
 
+    else item;
   end match;
 end qualify3;
 
@@ -1117,64 +1099,45 @@ protected
   Env env, rest_env;
   Option<String> name;
   FrameType ty;
-  AvlTree tree;
+  EnvTree.Tree tree;
   list<Extends> bcl;
   list<SCode.Element> re;
   NFSCodeEnv.ImportTable imps;
   Option<Util.StatefulBoolean> iu;
 algorithm
   NFSCodeEnv.FRAME(name, ty, tree,
     NFSCodeEnv.EXTENDS_TABLE(bcl, re, _), imps, iu) :: rest_env := inEnv;
-  SOME(tree) := update3(SOME(tree), inEnv);
+  tree := EnvTree.map(tree, function update3(inEnv = inEnv));
   env := NFSCodeEnv.FRAME(name, ty, tree,
     NFSCodeEnv.EXTENDS_TABLE(bcl, {}, NONE()), imps, iu) :: rest_env;
   outEnv := NFSCodeFlattenRedeclare.addElementRedeclarationsToEnv(re, env);
 end update2;
 
 protected function update3
-  input Option<AvlTree> inTree;
+  input String name;
+  input output Item item;
   input Env inEnv;
-  output Option<AvlTree> outTree;
 algorithm
-  outTree := match(inTree, inEnv)
+  () := match item
     local
-      String name;
-      Integer h;
-      Option<AvlTree> left, right;
       Env rest_env, env;
       SCode.Element cls;
-      Frame cls_env;
-      Option<NFSCodeEnv.AvlTreeValue> value;
-      Item item;
       ClassType cls_ty;
+      Frame cls_env;
 
-    case (NONE(), _) then inTree;
-
-    case (SOME(NFSCodeEnv.AVLTREENODE(SOME(NFSCodeEnv.AVLTREEVALUE(
-        name, NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty))), h, left, right)), _)
-      equation
+    case NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty)
+      algorithm
         // Enter the class' frame and update the class extends in it.
-        env = NFSCodeEnv.enterFrame(cls_env, inEnv);
-        (cls, env) = updateClassExtends(cls, env, cls_ty);
+        env := NFSCodeEnv.enterFrame(cls_env, inEnv);
+        (cls, env) := updateClassExtends(cls, env, cls_ty);
         // Call update2 on the class' environment to update the extends.
-        cls_env :: rest_env = update2(env);
-        // Recurse into left and right branch of the tree.
-        left = update3(left, rest_env);
-        right = update3(right, rest_env);
+        cls_env :: rest_env := update2(env);
         // Rebuild the class item with the updated information.
-        item = NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty);
-        value = SOME(NFSCodeEnv.AVLTREEVALUE(name, item));
+        item := NFSCodeEnv.CLASS(cls, {cls_env}, cls_ty);
       then
-        SOME(NFSCodeEnv.AVLTREENODE(value, h, left, right));
-
-    case (SOME(NFSCodeEnv.AVLTREENODE(value, h, left, right)), _)
-      equation
-        // Recurse into left and right branch of the tree.
-        left = update3(left, inEnv);
-        right = update3(right, inEnv);
-      then
-        SOME(NFSCodeEnv.AVLTREENODE(value, h, left, right));
+        ();
 
+    else ();
   end match;
 end update3;
 

Compiler/FrontEnd/NFSCodeCheck.mo

@@ -49,6 +49,8 @@ protected import Flags;
 protected import NFInstDump;
 protected import SCodeDump;
 
+import NFSCodeEnv.EnvTree;
+
 public function checkRecursiveShortDefinition
   input Absyn.TypeSpec inTypeSpec;
   input String inTypeName;
@@ -474,7 +476,7 @@ algorithm
       inComponentEnv)
     local
       String cls_name, ty_name;
-      NFSCodeEnv.AvlTree tree;
+      EnvTree.Tree tree;
       SCode.Element el;
 
     // No environment means one of the basic types.
@@ -492,7 +494,7 @@ algorithm
     case (_, _, _, _, NFSCodeEnv.FRAME(name = SOME(cls_name)) ::
         NFSCodeEnv.FRAME(clsAndVars = tree) :: _)
       equation
-        NFSCodeEnv.CLASS(cls = el) = NFSCodeEnv.avlTreeGet(tree, cls_name);
+        NFSCodeEnv.CLASS(cls = el) = EnvTree.get(tree, cls_name);
         true = SCode.isFunction(el);
       then
         ();