Fix private member name mangling.

frog/library.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class LibraryImport {
   final String prefix;
   final Library library;
   final SourceSpan span;
   LibraryImport(this.library, [this.prefix, this.span]);
 }
@@ skipping 76 matching lines @@
       return world._members[name];
     }
   }
 
   _addMember(Member member) {
     if (member.isPrivate) {
       if (member.isStatic) {
         if (member.declaringType.isTop) {
           world._addTopName(member);
         }
-        return;
-      }
-
-      var mset = _privateMembers[member.name];
-      if (mset == null) {
-        // TODO(jimhug): Make this lazier!
-        for (var lib in world.libraries.getValues()) {
-          if (lib._privateMembers.containsKey(member.jsname)) {
-            member._jsname = '_$jsname${member.jsname}';
-            break;
-          }
+      } else {
+        var members = _privateMembers[member.name];
+        if (members == null) {
+          members = new MemberSet(member, isVar: true);
+          _privateMembers[member.name] = members;
+        } else {
+          members.add(member);
         }
-
-        mset = new MemberSet(member, isVar:true);
-        _privateMembers[member.name] = mset;
-      } else {
-        mset.members.add(member);
+        _makePrivateMembersUnique(member, members);
       }
     } else {
       world._addMember(member);
     }
   }
 
+  void _makePrivateMembersUnique(Member member, MemberSet members) {
+    // If the JS name in the member set is already unique, we simply
+    // copy the name to the new member.
+    if (members.jsnameUnique) {
+      member._jsname = members.jsname;
+      return;
+    }
+
+    // Run through the other libraries in the world and check if any
+    // of them has a clashing private member. If so, we rewrite this
+    // one and all other members in the set.
+    String name = members.name;
+    for (var lib in world.libraries.getValues()) {
+      if (lib !== this && lib._privateMembers.containsKey(name)) {
+        String uniqueName = '_${this.jsname}${members.jsname}';
+        members.jsname = uniqueName;
+        members.jsnameUnique = true;
+        members.members.forEach((each) { each._jsname = uniqueName; });
+        assert(member.jsname == members.jsname);
+        return;
+      }
+    }
+  }
+
   // TODO(jimhug): Cache and share the types as interfaces!
   Type getOrAddFunctionType(Element enclosingElement, String name,
       FunctionDefinition func, MethodData data) {
     // TODO(jimhug): This is redundant now that FunctionDef has type params.
     final def = new FunctionTypeDefinition(func, null, func.span);
     final type = new DefinedType(name, this, def, false);
     type.addMethod(':call', func);
     var m = type.members[':call'];
     m.enclosingElement = enclosingElement;
     m.resolve();
@@ skipping 382 matching lines @@
 
   void visitFunctionDefinition(FunctionDefinition node) {
     currentType.addMethod(node.name.name, node);
   }
 
   void visitFunctionTypeDefinition(FunctionTypeDefinition node) {
     var type = library.addType(node.func.name.name, node, false);
     type.addMethod(':call', node.func);
   }
 }