Add quick-info support for ref members and locals.

src/Compilers/CSharp/Portable/SymbolDisplay/SymbolDisplayVisitor.cs

@@ -177,6 +177,13 @@ private void AddGlobalNamespace(INamespaceSymbol globalNamespace)
 
         public override void VisitLocal(ILocalSymbol symbol)
         {
+            if (symbol.IsRef && 
+                format.LocalOptions.IncludesOption(SymbolDisplayLocalOptions.IncludeRef))
+            {
+                AddKeyword(SyntaxKind.RefKeyword);
+                AddSpace();
+            }
+
             if (format.LocalOptions.IncludesOption(SymbolDisplayLocalOptions.IncludeType))
             {
                 symbol.Type.Accept(this);

src/Compilers/CSharp/Portable/Symbols/LocalSymbol.cs

@@ -315,6 +315,8 @@ public object ConstantValue
 
         internal abstract ImmutableArray<Diagnostic> GetConstantValueDiagnostics(BoundExpression boundInitValue);
 
+        public bool IsRef => RefKind == RefKind.Ref;
+
         internal abstract RefKind RefKind
         {
             get;

src/Compilers/Core/Portable/PublicAPI.Unshipped.txt

@@ -11,6 +11,7 @@ Microsoft.CodeAnalysis.CommandLineArguments.DisplayVersion.get -> bool
 Microsoft.CodeAnalysis.CommandLineArguments.EmbeddedFiles.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.CommandLineSourceFile>
 Microsoft.CodeAnalysis.CommandLineArguments.SourceLink.get -> string
 Microsoft.CodeAnalysis.Compilation.CreateAnonymousTypeSymbol(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.ITypeSymbol> memberTypes, System.Collections.Immutable.ImmutableArray<string> memberNames, System.Collections.Immutable.ImmutableArray<bool> memberIsReadOnly = default(System.Collections.Immutable.ImmutableArray<bool>), System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Location> memberLocations = default(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Location>)) -> Microsoft.CodeAnalysis.INamedTypeSymbol
+Microsoft.CodeAnalysis.Compilation.CreateErrorNamespaceSymbol(Microsoft.CodeAnalysis.INamespaceSymbol container, string name) -> Microsoft.CodeAnalysis.INamespaceSymbol
 Microsoft.CodeAnalysis.Compilation.CreateTupleTypeSymbol(Microsoft.CodeAnalysis.INamedTypeSymbol underlyingType, System.Collections.Immutable.ImmutableArray<string> elementNames = default(System.Collections.Immutable.ImmutableArray<string>), System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Location> elementLocations = default(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Location>)) -> Microsoft.CodeAnalysis.INamedTypeSymbol
 Microsoft.CodeAnalysis.Compilation.CreateTupleTypeSymbol(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.ITypeSymbol> elementTypes, System.Collections.Immutable.ImmutableArray<string> elementNames = default(System.Collections.Immutable.ImmutableArray<string>), System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Location> elementLocations = default(System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Location>)) -> Microsoft.CodeAnalysis.INamedTypeSymbol
 Microsoft.CodeAnalysis.Compilation.Emit(System.IO.Stream peStream, System.IO.Stream pdbStream = null, System.IO.Stream xmlDocumentationStream = null, System.IO.Stream win32Resources = null, System.Collections.Generic.IEnumerable<Microsoft.CodeAnalysis.ResourceDescription> manifestResources = null, Microsoft.CodeAnalysis.Emit.EmitOptions options = null, Microsoft.CodeAnalysis.IMethodSymbol debugEntryPoint = null, System.IO.Stream sourceLinkStream = null, System.Collections.Generic.IEnumerable<Microsoft.CodeAnalysis.EmbeddedText> embeddedTexts = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> Microsoft.CodeAnalysis.Emit.EmitResult
@@ -90,6 +91,7 @@ Microsoft.CodeAnalysis.IArrayTypeSymbol.Sizes.get -> System.Collections.Immutabl
 Microsoft.CodeAnalysis.IDiscardSymbol
 Microsoft.CodeAnalysis.IDiscardSymbol.Type.get -> Microsoft.CodeAnalysis.ITypeSymbol
 Microsoft.CodeAnalysis.IFieldSymbol.CorrespondingTupleField.get -> Microsoft.CodeAnalysis.IFieldSymbol
+Microsoft.CodeAnalysis.ILocalSymbol.IsRef.get -> bool
 Microsoft.CodeAnalysis.IMethodSymbol.RefCustomModifiers.get -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.CustomModifier>
 Microsoft.CodeAnalysis.IMethodSymbol.ReturnsByRef.get -> bool
 Microsoft.CodeAnalysis.INamedTypeSymbol.GetTypeArgumentCustomModifiers(int ordinal) -> System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.CustomModifier>
@@ -725,11 +727,11 @@ Microsoft.CodeAnalysis.Semantics.UnaryOperationKind.UnsignedPrefixIncrement = 77
 Microsoft.CodeAnalysis.SymbolDisplayFormat.RemoveGenericsOptions(Microsoft.CodeAnalysis.SymbolDisplayGenericsOptions options) -> Microsoft.CodeAnalysis.SymbolDisplayFormat
 Microsoft.CodeAnalysis.SymbolDisplayFormat.RemoveLocalOptions(Microsoft.CodeAnalysis.SymbolDisplayLocalOptions options) -> Microsoft.CodeAnalysis.SymbolDisplayFormat
 Microsoft.CodeAnalysis.SymbolDisplayFormat.RemoveMiscellaneousOptions(Microsoft.CodeAnalysis.SymbolDisplayMiscellaneousOptions options) -> Microsoft.CodeAnalysis.SymbolDisplayFormat
+Microsoft.CodeAnalysis.SymbolDisplayLocalOptions.IncludeRef = 4 -> Microsoft.CodeAnalysis.SymbolDisplayLocalOptions
 Microsoft.CodeAnalysis.SymbolDisplayMemberOptions.IncludeRef = 128 -> Microsoft.CodeAnalysis.SymbolDisplayMemberOptions
 Microsoft.CodeAnalysis.SymbolKind.Discard = 19 -> Microsoft.CodeAnalysis.SymbolKind
 Microsoft.CodeAnalysis.Text.SourceText.CanBeEmbedded.get -> bool
 Microsoft.CodeAnalysis.Text.SourceText.GetChecksum() -> System.Collections.Immutable.ImmutableArray<byte>
-Microsoft.CodeAnalysis.Compilation.CreateErrorNamespaceSymbol(Microsoft.CodeAnalysis.INamespaceSymbol container, string name) -> Microsoft.CodeAnalysis.INamespaceSymbol
 abstract Microsoft.CodeAnalysis.CompilationOptions.Language.get -> string
 abstract Microsoft.CodeAnalysis.Diagnostics.OperationBlockStartAnalysisContext.RegisterOperationAction(System.Action<Microsoft.CodeAnalysis.Diagnostics.OperationAnalysisContext> action, System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.OperationKind> operationKinds) -> void
 abstract Microsoft.CodeAnalysis.Diagnostics.OperationBlockStartAnalysisContext.RegisterOperationBlockEndAction(System.Action<Microsoft.CodeAnalysis.Diagnostics.OperationBlockAnalysisContext> action) -> void

src/Compilers/Core/Portable/SymbolDisplay/SymbolDisplayLocalOptions.cs

@@ -27,5 +27,10 @@ public enum SymbolDisplayLocalOptions
         /// For example "x = 1".
         /// </summary>
         IncludeConstantValue = 1 << 1,
+
+        /// <summary>
+        /// Includes the <c>ref</c> keyword for ref-locals.
+        /// </summary>
+        IncludeRef = 1 << 2,
     }
 }

src/Compilers/Core/Portable/Symbols/ILocalSymbol.cs

@@ -22,6 +22,11 @@ public interface ILocalSymbol : ISymbol
         /// </summary>
         bool IsConst { get; }
 
+        /// <summary>
+        /// Returns true if this local is a ref-local.
+        /// </summary>
+        bool IsRef { get; }
+
         /// <summary>
         /// Returns false if the local variable wasn't declared as "const", or constant value was omitted or erroneous.
         /// True otherwise.
@@ -36,4 +41,4 @@ public interface ILocalSymbol : ISymbol
         // TODO: Add XML doc comment.
         bool IsFunctionValue { get; }
     }
-}
+}
\ No newline at end of file

src/Compilers/VisualBasic/Portable/Symbols/Source/LocalSymbol.vb

@@ -280,6 +280,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
             End Get
         End Property
 
+        Public ReadOnly Property IsRef As Boolean Implements ILocalSymbol.IsRef
+            Get
+                Return False
+            End Get
+        End Property
+
         Public MustOverride ReadOnly Property IsFunctionValue As Boolean Implements ILocalSymbol.IsFunctionValue
 
         Friend ReadOnly Property IsCompilerGenerated As Boolean

src/EditorFeatures/CSharpTest/QuickInfo/SemanticQuickInfoSourceTests.cs

@@ -4743,5 +4743,47 @@ class C : I
 }",
                 MainDescription("(int, int) C.Name { get; set; }"));
         }
+
+        [Fact, Trait(Traits.Feature, Traits.Features.QuickInfo)]
+        public async Task TestRefMethod()
+        {
+            await TestInMethodAsync(
+@"using System;
+
+class Program
+{
+    static void Main(string[] args)
+    {
+        ref int i = ref $$foo();
+    }
+
+    private static ref int foo()
+    {
+        throw new NotImplementedException();
+    }
+}",
+                MainDescription("ref int Program.foo()"));
+        }
+
+        [Fact, Trait(Traits.Feature, Traits.Features.QuickInfo)]
+        public async Task TestRefLocal()
+        {
+            await TestInMethodAsync(
+@"using System;
+
+class Program
+{
+    static void Main(string[] args)
+    {
+        ref int $$i = ref foo();
+    }
+
+    private static ref int foo()
+    {
+        throw new NotImplementedException();
+    }
+}",
+                MainDescription($"({FeaturesResources.local_variable}) ref int i"));
+        }
     }
 }
\ No newline at end of file

src/Features/CSharp/Portable/LanguageServices/CSharpSymbolDisplayService.SymbolDescriptionBuilder.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 System.Collections.Immutable;
-using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.Classification;
@@ -19,6 +17,7 @@ internal partial class CSharpSymbolDisplayService
         protected class SymbolDescriptionBuilder : AbstractSymbolDescriptionBuilder
         {
             private static readonly SymbolDisplayFormat s_minimallyQualifiedFormat = SymbolDisplayFormat.MinimallyQualifiedFormat
+                .AddLocalOptions(SymbolDisplayLocalOptions.IncludeRef)
                 .AddMiscellaneousOptions(SymbolDisplayMiscellaneousOptions.UseErrorTypeSymbolName)
                 .RemoveParameterOptions(SymbolDisplayParameterOptions.IncludeDefaultValue)
                 .WithKindOptions(SymbolDisplayKindOptions.None);

src/Features/Core/Portable/LanguageServices/SymbolDisplayService/AbstractSymbolDisplayService.AbstractSymbolDescriptionBuilder.cs

@@ -35,8 +35,9 @@ protected abstract partial class AbstractSymbolDescriptionBuilder
                     globalNamespaceStyle: SymbolDisplayGlobalNamespaceStyle.Omitted,
                     genericsOptions: SymbolDisplayGenericsOptions.IncludeTypeParameters | SymbolDisplayGenericsOptions.IncludeTypeConstraints,
                     memberOptions:
-                        SymbolDisplayMemberOptions.IncludeParameters |
+                        SymbolDisplayMemberOptions.IncludeRef |
                         SymbolDisplayMemberOptions.IncludeType |
+                        SymbolDisplayMemberOptions.IncludeParameters |
                         SymbolDisplayMemberOptions.IncludeContainingType,
                     kindOptions:
                         SymbolDisplayKindOptions.IncludeMemberKeyword,
@@ -49,7 +50,9 @@ protected abstract partial class AbstractSymbolDescriptionBuilder
                         SymbolDisplayParameterOptions.IncludeExtensionThis |
                         SymbolDisplayParameterOptions.IncludeDefaultValue |
                         SymbolDisplayParameterOptions.IncludeOptionalBrackets,
-                    localOptions: SymbolDisplayLocalOptions.IncludeType,
+                    localOptions:
+                        SymbolDisplayLocalOptions.IncludeRef |
+                        SymbolDisplayLocalOptions.IncludeType,
                     miscellaneousOptions:
                         SymbolDisplayMiscellaneousOptions.EscapeKeywordIdentifiers |
                         SymbolDisplayMiscellaneousOptions.UseSpecialTypes |

src/Features/Core/Portable/LanguageServices/SymbolDisplayService/AbstractSymbolDisplayService.cs

@@ -65,4 +65,4 @@ public async Task<ImmutableArray<SymbolDisplayPart>> ToDescriptionPartsAsync(Wor
             return await builder.BuildDescriptionSectionsAsync(symbols).ConfigureAwait(false);
         }
     }
-}
+}
\ No newline at end of file