Merge remote-tracking branch 'upstream/master' into renameInaccessibleSymbols

4e12c1c2 · CyrusNajmabadi · ea966065 · edd701d4 · 4e12c1c2 · 4e12c1c2
15 changed file
--- a/Roslyn.sln
+++ b/Roslyn.sln
@@ -450,8 +450,8 @@ Global
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|ARM.Build.0 = Debug|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
-		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|x64.ActiveCfg = Debug|x64
-		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|x64.Build.0 = Debug|x64
+		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|x64.Build.0 = Debug|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|x86.ActiveCfg = Debug|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Debug|x86.Build.0 = Debug|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -460,8 +460,8 @@ Global
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|ARM.Build.0 = Release|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|Mixed Platforms.Build.0 = Release|Any CPU
-		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|x64.ActiveCfg = Release|x64
-		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|x64.Build.0 = Release|x64
+		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|x64.ActiveCfg = Release|Any CPU
+		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|x64.Build.0 = Release|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|x86.ActiveCfg = Release|Any CPU
 		{1EE8CAD3-55F9-4D91-96B2-084641DA9A6C}.Release|x86.Build.0 = Release|Any CPU
 		{9508F118-F62E-4C16-A6F4-7C3B56E166AD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
@@ -486,22 +486,22 @@ Global
 		{9508F118-F62E-4C16-A6F4-7C3B56E166AD}.Release|x86.Build.0 = Release|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|ARM.ActiveCfg = Debug|ARM
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|ARM.Build.0 = Debug|ARM
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|ARM.Build.0 = Debug|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|x64.ActiveCfg = Debug|x64
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|x64.Build.0 = Debug|x64
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|x64.Build.0 = Debug|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|x86.ActiveCfg = Debug|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Debug|x86.Build.0 = Debug|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|Any CPU.Build.0 = Release|Any CPU
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|ARM.ActiveCfg = Release|ARM
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|ARM.Build.0 = Release|ARM
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|ARM.ActiveCfg = Release|Any CPU
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|ARM.Build.0 = Release|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|Mixed Platforms.Build.0 = Release|Any CPU
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|x64.ActiveCfg = Release|x64
-		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|x64.Build.0 = Release|x64
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|x64.ActiveCfg = Release|Any CPU
+		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|x64.Build.0 = Release|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|x86.ActiveCfg = Release|Any CPU
 		{F5CE416E-B906-41D2-80B9-0078E887A3F6}.Release|x86.Build.0 = Release|Any CPU
 		{4B45CA0C-03A0-400F-B454-3D4BCB16AF38}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
@@ -530,8 +530,8 @@ Global
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|ARM.Build.0 = Debug|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
-		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|x64.ActiveCfg = Debug|x64
-		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|x64.Build.0 = Debug|x64
+		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|x64.Build.0 = Debug|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|x86.ActiveCfg = Debug|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Debug|x86.Build.0 = Debug|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -540,8 +540,8 @@ Global
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|ARM.Build.0 = Release|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|Mixed Platforms.Build.0 = Release|Any CPU
-		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|x64.ActiveCfg = Release|x64
-		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|x64.Build.0 = Release|x64
+		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|x64.ActiveCfg = Release|Any CPU
+		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|x64.Build.0 = Release|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|x86.ActiveCfg = Release|Any CPU
 		{B501A547-C911-4A05-AC6E-274A50DFF30E}.Release|x86.Build.0 = Release|Any CPU
 		{50D26304-0961-4A51-ABF6-6CAD1A56D203}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
@@ -646,22 +646,22 @@ Global
 		{50D26304-0961-4A51-ABF6-6CAD1A56D202}.Release|x86.Build.0 = Release|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|ARM.ActiveCfg = Debug|ARM
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|ARM.Build.0 = Debug|ARM
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|ARM.Build.0 = Debug|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|x64.ActiveCfg = Debug|x64
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|x64.Build.0 = Debug|x64
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|x64.Build.0 = Debug|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|x86.ActiveCfg = Debug|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Debug|x86.Build.0 = Debug|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|Any CPU.Build.0 = Release|Any CPU
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|ARM.ActiveCfg = Release|ARM
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|ARM.Build.0 = Release|ARM
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|ARM.ActiveCfg = Release|Any CPU
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|ARM.Build.0 = Release|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|Mixed Platforms.Build.0 = Release|Any CPU
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|x64.ActiveCfg = Release|x64
-		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|x64.Build.0 = Release|x64
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|x64.ActiveCfg = Release|Any CPU
+		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|x64.Build.0 = Release|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|x86.ActiveCfg = Release|Any CPU
 		{7FE6B002-89D8-4298-9B1B-0B5C247DD1FD}.Release|x86.Build.0 = Release|Any CPU
 		{F7712928-1175-47B3-8819-EE086753DEE2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
@@ -2178,21 +2178,21 @@ Global
 		{FCFA8808-A1B6-48CC-A1EA-0B8CA8AEDA8E}.Release|x86.Build.0 = Release|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|ARM.ActiveCfg = Debug|ARM
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|ARM.Build.0 = Debug|ARM
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|ARM.Build.0 = Debug|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|x64.ActiveCfg = Debug|x64
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|x64.Build.0 = Debug|x64
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|x64.Build.0 = Debug|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Debug|x86.ActiveCfg = Debug|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|ARM.ActiveCfg = Release|ARM
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|ARM.Build.0 = Release|ARM
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|ARM.ActiveCfg = Release|Any CPU
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|ARM.Build.0 = Release|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|Mixed Platforms.Build.0 = Release|Any CPU
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|x64.ActiveCfg = Release|x64
-		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|x64.Build.0 = Release|x64
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|x64.ActiveCfg = Release|Any CPU
+		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|x64.Build.0 = Release|Any CPU
 		{1DFEA9C5-973C-4179-9B1B-0F32288E1EF2}.Release|x86.ActiveCfg = Release|Any CPU
 		{76242A2D-2600-49DD-8C15-FEA07ECB1842}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{76242A2D-2600-49DD-8C15-FEA07ECB1842}.Debug|Any CPU.Build.0 = Debug|Any CPU

--- a/src/Compilers/Core/Portable/Compilation.EmitStreamProvider.cs
+++ b/src/Compilers/Core/Portable/Compilation.EmitStreamProvider.cs
@@ -59,4 +59,4 @@ public override Stream CreateStream(DiagnosticBag diagnostics)
            }
        }
    }
-}
+}
\ No newline at end of file
--- a/src/EditorFeatures/CSharpTest/Diagnostics/AddUsing/AddUsingTests.cs
+++ b/src/EditorFeatures/CSharpTest/Diagnostics/AddUsing/AddUsingTests.cs
@@ -4373,6 +4373,43 @@ class C
 compareTokens: false);
        }

+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsAddUsing)]
+        public async Task TestPlaceUsingWithUsings_NotWithAliases()
+        {
+            await TestAsync(
+@"
+using System;
+
+namespace N
+{
+    using C = System.Collections;
+
+    class Class
+    {
+        [|List<int>|] Method()
+        {
+            Foo();
+        }
+    }
+}",
+@"
+using System;
+using System.Collections.Generic;
+
+namespace N
+{
+    using C = System.Collections;
+
+    class Class
+    {
+        List<int> Method()
+        {
+            Foo();
+        }
+    }
+}");
+        }
+
        public partial class AddUsingTestsWithAddImportDiagnosticProvider : AbstractCSharpDiagnosticProviderBasedUserDiagnosticTest
        {
            internal override Tuple<DiagnosticAnalyzer, CodeFixProvider> CreateDiagnosticProviderAndFixer(Workspace workspace)

--- a/src/Features/CSharp/Portable/CodeFixes/AddImport/CSharpAddImportCodeFixProvider.cs
+++ b/src/Features/CSharp/Portable/CodeFixes/AddImport/CSharpAddImportCodeFixProvider.cs
@@ -7,6 +7,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.AddImport;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
 using Microsoft.CodeAnalysis.CodeFixes.AddImport;
@@ -395,6 +396,7 @@ protected override string GetDescription(IReadOnlyList<string> nameParts)
        }

        protected override string TryGetDescription(
+            Document document,
            INamespaceOrTypeSymbol namespaceOrTypeSymbol,
            SemanticModel semanticModel,
            SyntaxNode contextNode,
@@ -415,7 +417,7 @@ protected override string GetDescription(IReadOnlyList<string> nameParts)
            }

            var usingDirective = TryGetUsingDirective(
-                namespaceOrTypeSymbol, semanticModel, root, contextNode);
+                document, namespaceOrTypeSymbol, semanticModel, root, contextNode);

            if (usingDirective != null)
            {
@@ -465,63 +467,33 @@ protected override string GetDescription(IReadOnlyList<string> nameParts)
        {
            var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);

-            var firstContainingNamespaceWithUsings = GetFirstContainingNamespaceWithUsings(contextNode);
-            var namespaceToUpdate = firstContainingNamespaceWithUsings;
-
            var externAliasDirective = TryGetExternAliasDirective(
                namespaceOrTypeSymbol, semanticModel, contextNode,
                checkForExistingExternAlias: true);

            var usingDirective = TryGetUsingDirective(
-                namespaceOrTypeSymbol, semanticModel, root, contextNode);
+                document, namespaceOrTypeSymbol, semanticModel, root, contextNode);

-            if (externAliasDirective != null)
+            var newImports = ArrayBuilder<SyntaxNode>.GetInstance();
+            try
            {
-                AddExterns(ref root, ref namespaceToUpdate, externAliasDirective);
-            }
-
-            if (usingDirective != null)
-            {
-                AddUsingDirective(ref root, ref namespaceToUpdate,
-                    placeSystemNamespaceFirst, usingDirective);
-            }
-
-            return firstContainingNamespaceWithUsings != null
-                ? root.ReplaceNode(firstContainingNamespaceWithUsings, namespaceToUpdate)
-                : root;
-        }
+                if (externAliasDirective != null)
+                {
+                    newImports.Add(externAliasDirective);
+                }

-        private void AddUsingDirective(
-            ref CompilationUnitSyntax root,
-            ref NamespaceDeclarationSyntax namespaceToUpdate,
-            bool placeSystemNamespaceFirst,
-            UsingDirectiveSyntax usingDirective)
-        {
-            IList<UsingDirectiveSyntax> directives = new[] { usingDirective };
-            if (namespaceToUpdate != null)
-            {
-                namespaceToUpdate = namespaceToUpdate.AddUsingDirectives(
-                    directives, placeSystemNamespaceFirst);
-            }
-            else
-            {
-                root = root.AddUsingDirectives(
-                    directives, placeSystemNamespaceFirst);
-            }
-        }
+                if (usingDirective != null)
+                {
+                    newImports.Add(usingDirective);
+                }

-        private void AddExterns(
-            ref CompilationUnitSyntax root,
-            ref NamespaceDeclarationSyntax namespaceToUpdate,
-            ExternAliasDirectiveSyntax externAliasDirective)
-        {
-            if (namespaceToUpdate != null)
-            {
-                namespaceToUpdate = namespaceToUpdate.AddExterns(externAliasDirective);
+                var addImportService = document.GetLanguageService<IAddImportService>();
+                var newRoot = addImportService.AddImports(root, contextNode, newImports, placeSystemNamespaceFirst);
+                return (CompilationUnitSyntax)newRoot;
            }
-            else
+            finally
            {
-                root = root.AddExterns(externAliasDirective);
+                newImports.Free();
            }
        }

@@ -581,15 +553,19 @@ private NameSyntax CreateNameSyntax(IReadOnlyList<string> namespaceParts, int in
        }

        private UsingDirectiveSyntax TryGetUsingDirective(
+            Document document,
            INamespaceOrTypeSymbol namespaceOrTypeSymbol,
            SemanticModel semanticModel,
            CompilationUnitSyntax root,
            SyntaxNode contextNode)
        {
-            var namespaceToAddTo = GetFirstContainingNamespaceWithUsings(contextNode);
-            var usingDirectives = namespaceToAddTo?.Usings ?? root.Usings;
+            var addImportService = document.GetLanguageService<IAddImportService>();

            var nameSyntax = namespaceOrTypeSymbol.GenerateNameSyntax();
+            var dummyUsing = SyntaxFactory.UsingDirective(nameSyntax);
+
+            var container = addImportService.GetImportContainer(root, contextNode, dummyUsing);
+            var namespaceToAddTo = container as NamespaceDeclarationSyntax;

            // Replace the alias that GenerateTypeSyntax added if we want this to be looked
            // up off of an extern alias.
@@ -694,19 +670,6 @@ private NameSyntax CreateNameSyntax(IReadOnlyList<string> namespaceParts, int in
            return aliasName.WithAlias(alias);
        }

-        private NamespaceDeclarationSyntax GetFirstContainingNamespaceWithUsings(SyntaxNode contextNode)
-        {
-            var usingDirective = contextNode.GetAncestor<UsingDirectiveSyntax>();
-            if (usingDirective != null)
-            {
-                contextNode = usingDirective.Parent;
-            }
-
-            return contextNode.GetAncestors<NamespaceDeclarationSyntax>()
-                              .Where(n => n.Usings.Count > 0)
-                              .FirstOrDefault();
-        }
-
        private static bool TryGetExternAliasString(
            INamespaceOrTypeSymbol namespaceSymbol,
            SemanticModel semanticModel,

--- a/src/Features/Core/Portable/AddImport/AbstractAddImportCodeFixProvider.cs
+++ b/src/Features/Core/Portable/AddImport/AbstractAddImportCodeFixProvider.cs
@@ -52,7 +52,7 @@ internal abstract partial class AbstractAddImportCodeFixProvider<TSimpleNameSynt
        internal abstract bool IsAddMethodContext(SyntaxNode node, SemanticModel semanticModel);

        protected abstract string GetDescription(IReadOnlyList<string> nameParts);
-        protected abstract string TryGetDescription(INamespaceOrTypeSymbol symbol, SemanticModel semanticModel, SyntaxNode root, bool checkForExistingImport, CancellationToken cancellationToken);
+        protected abstract string TryGetDescription(Document document, INamespaceOrTypeSymbol symbol, SemanticModel semanticModel, SyntaxNode root, bool checkForExistingImport, CancellationToken cancellationToken);

        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {

--- a/src/Features/Core/Portable/AddImport/References/MetadataSymbolReference.cs
+++ b/src/Features/Core/Portable/AddImport/References/MetadataSymbolReference.cs
@@ -23,12 +23,12 @@ private partial class MetadataSymbolReference : SymbolReference
            }

            protected override string TryGetDescription(
-                Project project, SyntaxNode node, 
+                Document document, SyntaxNode node, 
                SemanticModel semanticModel, CancellationToken cancellationToken)
            {
                // If 'TryGetDescription' returns 'null' then that means that we don't actually want to add a reference
                // in this case.  As such, just continue to return the 'null' outwards.
-                var description = base.TryGetDescription(project, node, semanticModel, cancellationToken);
+                var description = base.TryGetDescription(document, node, semanticModel, cancellationToken);
                if (description == null)
                {
                    return null;

--- a/src/Features/Core/Portable/AddImport/References/ProjectSymbolReference.cs
+++ b/src/Features/Core/Portable/AddImport/References/ProjectSymbolReference.cs
@@ -73,15 +73,16 @@ protected override Solution GetUpdatedSolution(Document newDocument)
            }

            protected override string TryGetDescription(
-                Project project, SyntaxNode node, 
+                Document document, SyntaxNode node, 
                SemanticModel semanticModel, CancellationToken cancellationToken)
            {
-                var description = base.TryGetDescription(project, node, semanticModel, cancellationToken);
+                var description = base.TryGetDescription(document, node, semanticModel, cancellationToken);
                if (description == null)
                {
                    return null;
                }

+                var project = document.Project;
                return project.Id == _project.Id
                    ? description
                    : string.Format(FeaturesResources.Add_reference_to_0, _project.Name);

--- a/src/Features/Core/Portable/AddImport/References/SymbolReference.cs
+++ b/src/Features/Core/Portable/AddImport/References/SymbolReference.cs
@@ -73,7 +73,7 @@ protected virtual Solution GetUpdatedSolution(Document newDocument)
                bool placeSystemNamespaceFirst, CancellationToken cancellationToken)
            {
                var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
-                string description = TryGetDescription(document.Project, node, semanticModel, cancellationToken);
+                string description = TryGetDescription(document, node, semanticModel, cancellationToken);
                if (description == null)
                {
                    return null;
@@ -104,12 +104,12 @@ protected virtual Solution GetUpdatedSolution(Document newDocument)
            }

            protected virtual string TryGetDescription(
-                Project project, SyntaxNode node, 
+                Document document, SyntaxNode node, 
                SemanticModel semanticModel, CancellationToken cancellationToken)
            {
                return provider.TryGetDescription(
-                    SymbolResult.Symbol, semanticModel, node, 
-                    this.CheckForExistingImport(project), cancellationToken);
+                    document, SymbolResult.Symbol, semanticModel, node, 
+                    this.CheckForExistingImport(document.Project), cancellationToken);
            }
        }
    }

--- a/src/Features/VisualBasic/Portable/CodeFixes/AddImport/VisualBasicAddImportCodeFixProvider.vb
+++ b/src/Features/VisualBasic/Portable/CodeFixes/AddImport/VisualBasicAddImportCodeFixProvider.vb
@@ -248,6 +248,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.AddImport
        End Function

        Protected Overrides Function TryGetDescription(
+                document As Document,
                namespaceSymbol As INamespaceOrTypeSymbol,
                semanticModel As SemanticModel,
                root As SyntaxNode,
@@ -313,7 +314,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.AddImport
            Return symbol IsNot Nothing AndAlso symbol.Locations.Length > 0
        End Function

-        Protected Overloads Overrides Async Function AddImportAsync(
+        Protected Overloads Overrides Function AddImportAsync(
                contextNode As SyntaxNode,
                symbol As INamespaceOrTypeSymbol,
                document As Document,
@@ -322,9 +323,9 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.AddImport

            Dim nameSyntax = DirectCast(symbol.GenerateTypeSyntax(addGlobal:=False), NameSyntax)

-            Return Await AddImportsAsync(
+            Return AddImportsAsync(
                contextNode, document, placeSystemNamespaceFirst, nameSyntax,
-                additionalAnnotation:=Nothing, cancellationToken:=cancellationToken).ConfigureAwait(False)
+                additionalAnnotation:=Nothing, cancellationToken:=cancellationToken)
        End Function

        Private Shared Async Function AddImportsAsync(

--- a/src/VisualStudio/CSharp/Impl/Snippets/SnippetExpansionClient.cs
+++ b/src/VisualStudio/CSharp/Impl/Snippets/SnippetExpansionClient.cs
@@ -6,6 +6,7 @@
 using System.Threading;
 using System.Xml.Linq;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.AddImport;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Extensions;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -93,7 +94,10 @@ public override int GetExpansionFunction(IXMLDOMNode xmlFunctionNode, string bst
                return document;
            }

-            var newUsingDirectives = GetUsingDirectivesToAdd(document, snippetNode, importsNode, cancellationToken);
+            var root = document.GetSyntaxRootSynchronously(cancellationToken);
+            var contextLocation = root.FindToken(position).Parent;
+
+            var newUsingDirectives = GetUsingDirectivesToAdd(contextLocation, snippetNode, importsNode, cancellationToken);
            if (!newUsingDirectives.Any())
            {
                return document;
@@ -106,15 +110,9 @@ public override int GetExpansionFunction(IXMLDOMNode xmlFunctionNode, string bst
                return document;
            }

-            var root = document.GetSyntaxRootSynchronously(cancellationToken);
-            var node = root.FindToken(position).Parent;
-            var container = node.GetInnermostNamespaceDeclarationWithUsings() ?? (SyntaxNode)node.GetAncestorOrThis<CompilationUnitSyntax>();
-
-            var newContainer = container is NamespaceDeclarationSyntax n
-                ? (SyntaxNode)n.AddUsingDirectives(newUsingDirectives, placeSystemNamespaceFirst, Formatter.Annotation)
-                : ((CompilationUnitSyntax)container).AddUsingDirectives(newUsingDirectives, placeSystemNamespaceFirst);
+            var addImportService = document.GetLanguageService<IAddImportService>();
+            var newRoot = addImportService.AddImports(root, contextLocation, newUsingDirectives, placeSystemNamespaceFirst);

-            var newRoot = root.ReplaceNode(container, newContainer);
            var newDocument = document.WithSyntaxRoot(newRoot);

            var formattedDocument = Formatter.FormatAsync(newDocument, Formatter.Annotation, cancellationToken: cancellationToken).WaitAndGetResult(cancellationToken);
@@ -123,11 +121,11 @@ public override int GetExpansionFunction(IXMLDOMNode xmlFunctionNode, string bst
            return formattedDocument;
        }

-        private static IList<UsingDirectiveSyntax> GetUsingDirectivesToAdd(Document document, XElement snippetNode, XElement importsNode, CancellationToken cancellationToken)
+        private static IList<UsingDirectiveSyntax> GetUsingDirectivesToAdd(
+            SyntaxNode contextLocation, XElement snippetNode, XElement importsNode, CancellationToken cancellationToken)
        {
            var namespaceXmlName = XName.Get("Namespace", snippetNode.Name.NamespaceName);
-            var root = document.GetSyntaxRootSynchronously(cancellationToken);
-            var existingUsings = ((CompilationUnitSyntax)root).Usings;
+            var existingUsings = contextLocation.GetEnclosingUsingDirectives();
            var newUsings = new List<UsingDirectiveSyntax>();

            foreach (var import in importsNode.Elements(XName.Get("Import", snippetNode.Name.NamespaceName)))
@@ -150,7 +148,7 @@ private static IList<UsingDirectiveSyntax> GetUsingDirectivesToAdd(Document docu
                    continue;
                }

-                if (!existingUsings.Any(u => UsingsMatch(u, candidateUsing)))
+                if (!existingUsings.Any(u => u.IsEquivalentTo(candidateUsing, topLevel: false)))
                {
                    newUsings.Add(candidateUsing.WithAdditionalAnnotations(Formatter.Annotation).WithAppendedTrailingTrivia(SyntaxFactory.CarriageReturnLineFeed));
                }
@@ -159,11 +157,6 @@ private static IList<UsingDirectiveSyntax> GetUsingDirectivesToAdd(Document docu
            return newUsings;
        }

-        private static bool UsingsMatch(UsingDirectiveSyntax usingDirective1, UsingDirectiveSyntax usingDirective2)
-        {
-            return usingDirective1.Name.ToString() == usingDirective2.Name.ToString() && GetAliasName(usingDirective1) == GetAliasName(usingDirective2);
-        }
-
        private static string GetAliasName(UsingDirectiveSyntax usingDirective)
        {
            return (usingDirective.Alias == null || usingDirective.Alias.Name == null) ? null : usingDirective.Alias.Name.ToString();

--- a/src/Workspaces/CSharp/Portable/AddImport/CSharpAddImportService.cs
+++ b/src/Workspaces/CSharp/Portable/AddImport/CSharpAddImportService.cs
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Composition;
+using System.Linq;
+using Microsoft.CodeAnalysis.AddImport;
+using Microsoft.CodeAnalysis.CSharp.Extensions;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Microsoft.CodeAnalysis.Shared.Extensions;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.CSharp.AddImport
+{
+    [ExportLanguageService(typeof(IAddImportService), LanguageNames.CSharp), Shared]
+    internal class CSharpAddImportService : IAddImportService
+    {
+        private static readonly Func<UsingDirectiveSyntax, bool> s_isUsing = u => u.Alias == null;
+        private static readonly Func<UsingDirectiveSyntax, bool> s_isAlias = u => u.Alias != null;
+
+        private static readonly Func<SyntaxNode, bool> s_hasAliases = n => GetUsings(n).Any(s_isAlias);
+        private static readonly Func<SyntaxNode, bool> s_hasUsings = n => GetUsings(n).Any(s_isUsing);
+        private static readonly Func<SyntaxNode, bool> s_hasExterns = n => GetExterns(n).Any();
+
+        private static readonly Func<SyntaxNode, bool> s_hasAnyImports = n => GetUsings(n).Any() || GetExterns(n).Any();
+
+        public SyntaxNode GetImportContainer(SyntaxNode root, SyntaxNode contextLocation, SyntaxNode import)
+        {
+            contextLocation = contextLocation ?? root;
+            GetContainers(root, contextLocation,
+                out var externContainer, out var usingContainer, out var aliasContainer);
+
+            switch (import)
+            {
+                case ExternAliasDirectiveSyntax e: return externContainer;
+                case UsingDirectiveSyntax u: return s_isAlias(u) ? aliasContainer : usingContainer;
+            }
+
+            throw new InvalidOperationException();
+        }
+
+        public SyntaxNode AddImports(
+            SyntaxNode root,
+            SyntaxNode contextLocation,
+            IEnumerable<SyntaxNode> newImports,
+            bool placeSystemNamespaceFirst)
+        {
+            contextLocation = contextLocation ?? root;
+            GetContainers(root, contextLocation, 
+                out var externContainer, out var usingContainer, out var aliasContainer);
+
+            var externAliases = newImports.OfType<ExternAliasDirectiveSyntax>().ToArray();
+            var usingDirectives = newImports.OfType<UsingDirectiveSyntax>().Where(u => u.Alias == null).ToArray();
+            var aliasDirectives = newImports.OfType<UsingDirectiveSyntax>().Where(u => u.Alias != null).ToArray();
+
+            var rewriter = new Rewriter(
+                externAliases, usingDirectives, aliasDirectives,
+                externContainer, usingContainer, aliasContainer,
+                placeSystemNamespaceFirst);
+            var newRoot = rewriter.Visit(root);
+
+            return newRoot;
+        }
+
+        private static void GetContainers(SyntaxNode root, SyntaxNode contextLocation, out SyntaxNode externContainer, out SyntaxNode usingContainer, out SyntaxNode aliasContainer)
+        {
+            var applicableContainer = GetFirstApplicableContainer(contextLocation);
+            var contextSpine = applicableContainer.GetAncestorsOrThis<SyntaxNode>().ToImmutableArray();
+
+            // The node we'll add to if we can't find a specific namespace with imports of 
+            // the type we're trying to add.  This will be the closest namespace with any
+            // imports in it, or the root if there are no such namespaces.
+            var fallbackNode = contextSpine.FirstOrDefault(s_hasAnyImports) ?? root;
+
+            // The specific container to add each type of import to.  We look for a container
+            // that already has an import of the same type as the node we want to add to.
+            // If we can find one, we add to that container.  If not, we call back to the 
+            // innermost node with any imports.
+            externContainer = contextSpine.FirstOrDefault(s_hasExterns) ?? fallbackNode;
+            usingContainer = contextSpine.FirstOrDefault(s_hasUsings) ?? fallbackNode;
+            aliasContainer = contextSpine.FirstOrDefault(s_hasAliases) ?? fallbackNode;
+        }
+
+        private static SyntaxList<UsingDirectiveSyntax> GetUsings(SyntaxNode node)
+        {
+            switch (node)
+            {
+                case CompilationUnitSyntax c: return c.Usings;
+                case NamespaceDeclarationSyntax n: return n.Usings;
+                default: return default(SyntaxList<UsingDirectiveSyntax>);
+            }
+        }
+
+        private static SyntaxList<ExternAliasDirectiveSyntax> GetExterns(SyntaxNode node)
+        {
+            switch (node)
+            {
+                case CompilationUnitSyntax c: return c.Externs;
+                case NamespaceDeclarationSyntax n: return n.Externs;
+                default: return default(SyntaxList<ExternAliasDirectiveSyntax>);
+            }
+        }
+
+        private static SyntaxNode GetFirstApplicableContainer(SyntaxNode contextNode)
+        {
+            var usingDirective = contextNode.GetAncestor<UsingDirectiveSyntax>();
+            if (usingDirective != null)
+            {
+                contextNode = usingDirective.Parent;
+            }
+
+            return contextNode.GetAncestor<NamespaceDeclarationSyntax>() ??
+                   (SyntaxNode)contextNode.GetAncestor<CompilationUnitSyntax>();
+        }
+
+        private class Rewriter : CSharpSyntaxRewriter
+        {
+            private readonly bool _placeSystemNamespaceFirst;
+            private readonly SyntaxNode _externContainer;
+            private readonly SyntaxNode _usingContainer;
+            private readonly SyntaxNode _aliasContainer;
+
+            private readonly UsingDirectiveSyntax[] _aliasDirectives;
+            private readonly ExternAliasDirectiveSyntax[] _externAliases;
+            private readonly UsingDirectiveSyntax[] _usingDirectives;
+
+            public Rewriter(
+                ExternAliasDirectiveSyntax[] externAliases, 
+                UsingDirectiveSyntax[] usingDirectives, 
+                UsingDirectiveSyntax[] aliasDirectives,
+                SyntaxNode externContainer,
+                SyntaxNode usingContainer,
+                SyntaxNode aliasContainer,
+                bool placeSystemNamespaceFirst)
+            {
+                _externAliases = externAliases;
+                _usingDirectives = usingDirectives;
+                _aliasDirectives = aliasDirectives;
+                _externContainer = externContainer;
+                _usingContainer = usingContainer;
+                _aliasContainer = aliasContainer;
+                _placeSystemNamespaceFirst = placeSystemNamespaceFirst;
+            }
+
+            public override SyntaxNode VisitNamespaceDeclaration(NamespaceDeclarationSyntax node)
+            {
+                // recurse downwards so we visit inner namespaces first.
+                var rewritten = (NamespaceDeclarationSyntax)base.VisitNamespaceDeclaration(node);
+
+                if (node == _aliasContainer)
+                {
+                    rewritten = rewritten.AddUsingDirectives(_aliasDirectives, _placeSystemNamespaceFirst);
+                }
+
+                if (node == _usingContainer)
+                {
+                    rewritten = rewritten.AddUsingDirectives(_usingDirectives, _placeSystemNamespaceFirst);
+                }
+
+                if (node == _externContainer)
+                {
+                    rewritten = rewritten.AddExterns(_externAliases);
+                }
+
+                return rewritten;
+            }
+
+            public override SyntaxNode VisitCompilationUnit(CompilationUnitSyntax node)
+            {
+                // recurse downwards so we visit inner namespaces first.
+                var rewritten = (CompilationUnitSyntax)base.VisitCompilationUnit(node);
+
+                if (node == _aliasContainer)
+                {
+                    rewritten = rewritten.AddUsingDirectives(_aliasDirectives, _placeSystemNamespaceFirst);
+                }
+
+                if (node == _usingContainer)
+                {
+                    rewritten = rewritten.AddUsingDirectives(_usingDirectives, _placeSystemNamespaceFirst);
+                }
+
+                if (node == _externContainer)
+                {
+                    rewritten = rewritten.AddExterns(_externAliases);
+                }
+
+                return rewritten;
+            }
+        }
+    }
+}
\ No newline at end of file
--- a/src/Workspaces/CSharp/Portable/CSharpWorkspace.csproj
+++ b/src/Workspaces/CSharp/Portable/CSharpWorkspace.csproj
@@ -51,6 +51,7 @@
    <InternalsVisibleToTest Include="Roslyn.Services.Test.Utilities2" />
  </ItemGroup>
  <ItemGroup>
+    <Compile Include="AddImport\CSharpAddImportService.cs" />
    <Compile Include="CaseCorrection\CSharpCaseCorrectionService.cs" />
    <Compile Include="Classification\ClassificationHelpers.cs" />
    <Compile Include="Classification\Classifiers\AbstractSyntaxClassifier.cs" />
@@ -246,4 +247,4 @@
    <PublicAPI Include="PublicAPI.Unshipped.txt" />
  </ItemGroup>
  <Import Project="..\..\..\..\build\Targets\Imports.targets" />
-</Project>
+</Project>
\ No newline at end of file
--- a/src/Workspaces/CSharp/Portable/Extensions/NamespaceDeclarationSyntaxExtensions.cs
+++ b/src/Workspaces/CSharp/Portable/Extensions/NamespaceDeclarationSyntaxExtensions.cs
@@ -22,7 +22,7 @@ internal static class NamespaceDeclarationSyntaxExtensions
            bool placeSystemNamespaceFirst,
            params SyntaxAnnotation[] annotations)
        {
-            if (!usingDirectives.Any())
+            if (usingDirectives.Count == 0)
            {
                return namespaceDeclaration;
            }

--- a/src/Workspaces/Core/Portable/AddImport/IAddImportService.cs
+++ b/src/Workspaces/Core/Portable/AddImport/IAddImportService.cs
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using Microsoft.CodeAnalysis.Host;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.AddImport
+{
+    internal interface IAddImportService : ILanguageService
+    {
+        SyntaxNode AddImports(
+            SyntaxNode root, SyntaxNode contextLocation, 
+            IEnumerable<SyntaxNode> newImports, bool placeSystemNamespaceFirst);
+
+        /// <summary>
+        /// Given a context location in a provided syntax tree, returns the appropriate container
+        /// that <paramref name="import"/> should should be added to.
+        /// </summary>
+        SyntaxNode GetImportContainer(SyntaxNode root, SyntaxNode contextLocation, SyntaxNode import);
+    }
+
+    internal static class IAddImportServiceExtensions
+    {
+        public static SyntaxNode AddImport(
+            this IAddImportService service, SyntaxNode root, SyntaxNode contextLocation, 
+            SyntaxNode newImport, bool placeSystemNamespaceFirst)
+        {
+            return service.AddImports(root, contextLocation,
+                SpecializedCollections.SingletonEnumerable(newImport), placeSystemNamespaceFirst);
+        }
+    }
+}
\ No newline at end of file
--- a/src/Workspaces/Core/Portable/Workspaces.csproj
+++ b/src/Workspaces/Core/Portable/Workspaces.csproj
@@ -294,6 +294,7 @@
    <Compile Include="..\..\..\Compilers\Core\Portable\InternalUtilities\UnicodeCharacterUtilities.cs">
      <Link>InternalUtilities\UnicodeCharacterUtilities.cs</Link>
    </Compile>
+    <Compile Include="AddImport\IAddImportService.cs" />
    <Compile Include="CaseCorrection\AbstractCaseCorrectionService.cs" />
    <Compile Include="CaseCorrection\CaseCorrector.cs" />
    <Compile Include="CaseCorrection\ICaseCorrectionService.cs" />
@@ -1090,7 +1091,8 @@
  </ItemGroup>
  <ItemGroup>
    <None Include="project.json">
-      <SubType></SubType>
+      <SubType>
+      </SubType>
    </None>
    <Compile Include="Utilities\BKTree.Builder.cs" />
    <Compile Include="SymbolKey\SymbolKey.SymbolKeyReader.cs" />
@@ -1099,4 +1101,4 @@
  </ItemGroup>
  <Import Project="..\..\..\Dependencies\PooledObjects\Microsoft.CodeAnalysis.PooledObjects.projitems" Label="Shared" />
  <Import Project="..\..\..\..\build\Targets\Imports.targets" />
-</Project>
+</Project>
\ No newline at end of file