Ensure locations are always provided, but don't store them yet.

pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart

 // Copyright (c) 2016, 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.
 
 library fasta.analyzer.ast_builder;
 
 import 'package:front_end/src/fasta/scanner/token.dart' show
     BeginGroupToken,
     Token;
 
@@ skipping 48 matching lines @@
 
   final Builder member;
 
   final ElementStore elementStore;
 
   bool isFirstIdentifier = false;
 
   AstBuilder(this.library, this.member, this.elementStore, Scope scope)
       : super(scope);
 
-  Uri get uri => library.uri;
+  Uri get uri => library.fileUri ?? library.uri;
 
-  createJumpTarget(JumpTargetKind kind) {
+  createJumpTarget(JumpTargetKind kind, int charOffset) {
     // TODO(ahe): Implement jump targets.
     return null;
   }
 
   void beginLiteralString(Token token) {
     debugEvent("beginLiteralString");
     push(token);
   }
 
   void handleStringPart(Token token) {
@@ skipping 53 matching lines @@
 
   void beginExpression(Token token) {
     isFirstIdentifier = true;
   }
 
   void handleIdentifier(Token token) {
     debugEvent("handleIdentifier");
     String name = token.value;
     SimpleIdentifier identifier = ast.simpleIdentifier(toAnalyzerToken(token));
     if (isFirstIdentifier) {
-      Builder builder = scope.lookup(name);
+      Builder builder = scope.lookup(name, token.charOffset, uri);
       if (builder != null) {
         Element element = elementStore[builder];
         assert(element != null);
         identifier.staticElement = element;
       }
     }
     push(identifier);
     isFirstIdentifier = false;
   }
 
@@ skipping 282 matching lines @@
     }
     push(ast.symbolLiteral(toAnalyzerToken(hashToken), components));
   }
 
   void endType(Token beginToken, Token endToken) {
     debugEvent("Type");
     TypeArgumentList arguments = pop();
     SimpleIdentifier name = pop();
     KernelClassElement cls = name.staticElement;
     if (cls == null) {
-      Builder builder = scope.lookup(name.name);
+      Builder builder = scope.lookup(name.name, beginToken.charOffset, uri);
       if (builder == null) {
         internalError("Undefined name: $name");
       }
       // TODO(paulberry,ahe): what if the type doesn't resolve to a class
       // element?
       cls = elementStore[builder];
       assert(cls != null);
       name.staticElement = cls;
     }
     push(ast.typeName(name, arguments)..type = cls.rawType);
@@ skipping 129 matching lines @@
     debugEvent("Modifier");
     // TODO(ahe): Don't ignore modifiers.
   }
 
   void handleModifiers(int count) {
     debugEvent("Modifiers");
     // TODO(ahe): Don't ignore modifiers.
     push(NullValue.Modifiers);
   }
 }