Report StaticTypeWarningCode.AMBIGUOUS_IMPORT when used as type annotation.

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/scope/LibraryImportScope.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/scope/LibraryImportScope.java
diff --git a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/scope/LibraryImportScope.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/scope/LibraryImportScope.java
index e8e7254c149d04c97fa3b66e8ada858540651fdd..136ad3d1a64624190584d6d4eeb8a7cfeaa9d1d8 100644
--- a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/scope/LibraryImportScope.java
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/scope/LibraryImportScope.java
@@ -13,12 +13,24 @@
  */
 package com.google.dart.engine.internal.scope;
 
+import com.google.dart.engine.ast.ASTNode;
+import com.google.dart.engine.ast.FunctionDeclaration;
+import com.google.dart.engine.ast.FunctionTypeAlias;
+import com.google.dart.engine.ast.Identifier;
+import com.google.dart.engine.ast.MethodDeclaration;
+import com.google.dart.engine.ast.SimpleFormalParameter;
+import com.google.dart.engine.ast.TypeArgumentList;
+import com.google.dart.engine.ast.TypeName;
+import com.google.dart.engine.ast.TypeParameter;
+import com.google.dart.engine.ast.VariableDeclarationList;
 import com.google.dart.engine.element.Element;
 import com.google.dart.engine.element.ImportElement;
 import com.google.dart.engine.element.LibraryElement;
 import com.google.dart.engine.error.AnalysisError;
 import com.google.dart.engine.error.AnalysisErrorListener;
 import com.google.dart.engine.error.CompileTimeErrorCode;
+import com.google.dart.engine.error.ErrorCode;
+import com.google.dart.engine.error.StaticTypeWarningCode;
 import com.google.dart.engine.internal.element.MultiplyDefinedElementImpl;
 
 import java.util.ArrayList;
@@ -31,6 +43,51 @@ import java.util.ArrayList;
  */
 public class LibraryImportScope extends Scope {
   /**
+   * @return {@code true} if the given {@link Identifier} is the part of type annotation.
+   */
+  private static boolean isTypeAnnotation(Identifier identifier) {
+    ASTNode parent = identifier.getParent();
+    if (parent instanceof TypeName) {
+      ASTNode parent2 = parent.getParent();
+      if (parent2 instanceof FunctionDeclaration) {
+        FunctionDeclaration decl = (FunctionDeclaration) parent2;
+        return decl.getReturnType() == parent;
+      }
+      if (parent2 instanceof FunctionTypeAlias) {
+        FunctionTypeAlias decl = (FunctionTypeAlias) parent2;
+        return decl.getReturnType() == parent;
+      }
+      if (parent2 instanceof MethodDeclaration) {
+        MethodDeclaration decl = (MethodDeclaration) parent2;
+        return decl.getReturnType() == parent;
+      }
+      if (parent2 instanceof VariableDeclarationList) {
+        VariableDeclarationList decl = (VariableDeclarationList) parent2;
+        return decl.getType() == parent;
+      }
+      if (parent2 instanceof SimpleFormalParameter) {
+        SimpleFormalParameter decl = (SimpleFormalParameter) parent2;
+        return decl.getType() == parent;
+      }
+      if (parent2 instanceof TypeParameter) {
+        TypeParameter decl = (TypeParameter) parent2;
+        return decl.getBound() == parent;
+      }
+      if (parent2 instanceof TypeArgumentList) {
+        ASTNode parent3 = parent2.getParent();
+        if (parent3 instanceof TypeName) {
+          TypeName typeName = (TypeName) parent3;
+          if ((typeName).getTypeArguments() == parent2) {
+            return isTypeAnnotation(typeName.getName());
+          }
+        }
+      }
+      return false;
+    }
+    return false;
+  }
+
+  /**
    * The element representing the library in which this scope is enclosed.
    */
   private LibraryElement definingLibrary;
@@ -77,7 +134,7 @@ public class LibraryImportScope extends Scope {
   }
 
   @Override
-  protected Element lookup(String name, LibraryElement referencingLibrary) {
+  protected Element lookup(Identifier identifier, String name, LibraryElement referencingLibrary) {
     Element foundElement = localLookup(name, referencingLibrary);
     if (foundElement != null) {
       return foundElement;
@@ -109,12 +166,17 @@ public class LibraryImportScope extends Scope {
       }
       // TODO (jwren) Change the error message to include a list of all library names instead of
       // just the first two
+      ErrorCode errorCode = isTypeAnnotation(identifier) ? StaticTypeWarningCode.AMBIGUOUS_IMPORT
+          : CompileTimeErrorCode.AMBIGUOUS_IMPORT;
       errorListener.onError(new AnalysisError(
           getSource(),
-          CompileTimeErrorCode.AMBIGUOUS_IMPORT,
+          identifier.getOffset(),
+          identifier.getLength(),
+          errorCode,
           foundEltName,
           libName1,
           libName2));
+      return foundElement;
     }
     if (foundElement != null) {
       defineWithoutChecking(foundElement);