Add 'ref T' AstType syntax node. This allows generating code for C# 7 'ref locals' and 'ref return'.

5 files changed, 55 insertions, 5 deletions

diff --git a/ICSharpCode.NRefactory.CSharp/Ast/AstType.cs b/ICSharpCode.NRefactory.CSharp/Ast/AstType.cs
index 2f13f0fd..80ca72ac 100644
--- a/ICSharpCode.NRefactory.CSharp/Ast/AstType.cs
+++ b/ICSharpCode.NRefactory.CSharp/Ast/AstType.cs
@@ -209,7 +209,15 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 			return new ComposedType { BaseType = this, HasNullableSpecifier = true };
 		}
-		
+
+		/// <summary>
+		/// Creates a C# 7 ref type from this type by nesting it in a <see cref="ComposedType"/>.
+		/// </summary>
+		public virtual AstType MakeRefType()
+		{
+			return new ComposedType { BaseType = this, HasRefSpecifier = true };
+		}
+
 		/// <summary>
 		/// Builds an expression that can be used to access a static member on this type.
 		/// </summary>
diff --git a/ICSharpCode.NRefactory.CSharp/Ast/ComposedType.cs b/ICSharpCode.NRefactory.CSharp/Ast/ComposedType.cs
index 0c0f96c6..2bbfc5a8 100644
--- a/ICSharpCode.NRefactory.CSharp/Ast/ComposedType.cs
+++ b/ICSharpCode.NRefactory.CSharp/Ast/ComposedType.cs
@@ -33,10 +33,25 @@ namespace ICSharpCode.NRefactory.CSharp
 {
 	public class ComposedType : AstType
 	{
+		public static readonly TokenRole RefRole = new TokenRole("ref");
 		public static readonly TokenRole NullableRole = new TokenRole("?");
 		public static readonly TokenRole PointerRole = new TokenRole("*");
 		public static readonly Role<ArraySpecifier> ArraySpecifierRole = new Role<ArraySpecifier>("ArraySpecifier");
-		
+
+		/// <summary>
+		/// Gets/sets whether this type has a 'ref' specifier.
+		/// This is used for C# 7 ref locals/ref return.
+		/// Parameters use ParameterDeclaration.ParameterModifier instead.
+		/// </summary>
+		public bool HasRefSpecifier {
+			get {
+				return !GetChildByRole(RefRole).IsNull;
+			}
+			set {
+				SetChildByRole(RefRole, value ? new CSharpTokenNode(TextLocation.Empty, null) : null);
+			}
+		}
+
 		public AstType BaseType {
 			get { return GetChildByRole(Roles.Type); }
 			set { SetChildByRole(Roles.Type, value); }
@@ -102,7 +117,10 @@ namespace ICSharpCode.NRefactory.CSharp
 		protected internal override bool DoMatch(AstNode other, PatternMatching.Match match)
 		{
 			ComposedType o = other as ComposedType;
-			return o != null && this.HasNullableSpecifier == o.HasNullableSpecifier && this.PointerRank == o.PointerRank
+			return o != null
+				&& this.HasNullableSpecifier == o.HasNullableSpecifier
+				&& this.PointerRank == o.PointerRank
+				&& this.HasRefSpecifier == o.HasRefSpecifier
 				&& this.BaseType.DoMatch(o.BaseType, match)
 				&& this.ArraySpecifiers.DoMatch(o.ArraySpecifiers, match);
 		}
@@ -110,6 +128,8 @@ namespace ICSharpCode.NRefactory.CSharp
 		public override string ToString(CSharpFormattingOptions formattingOptions)
 		{
 			StringBuilder b = new StringBuilder();
+			if (this.HasRefSpecifier)
+				b.Append("ref ");
 			b.Append(this.BaseType.ToString());
 			if (this.HasNullableSpecifier)
 				b.Append('?');
@@ -137,7 +157,13 @@ namespace ICSharpCode.NRefactory.CSharp
 			InsertChildBefore(this.ArraySpecifiers.FirstOrDefault(), new ArraySpecifier(dimensions), ArraySpecifierRole);
 			return this;
 		}
-		
+
+		public override AstType MakeRefType()
+		{
+			this.HasRefSpecifier = true;
+			return this;
+		}
+
 		public override ITypeReference ToTypeReference(NameLookupMode lookupMode, InterningProvider interningProvider = null)
 		{
 			if (interningProvider == null)
@@ -153,6 +179,9 @@ namespace ICSharpCode.NRefactory.CSharp
 			foreach (var a in this.ArraySpecifiers.Reverse()) {
 				t = interningProvider.Intern(new ArrayTypeReference(t, a.Dimensions));
 			}
+			if (this.HasRefSpecifier) {
+				t = interningProvider.Intern(new ByReferenceTypeReference(t));
+			}
 			return t;
 		}
 	}
diff --git a/ICSharpCode.NRefactory.CSharp/OutputVisitor/CSharpOutputVisitor.cs b/ICSharpCode.NRefactory.CSharp/OutputVisitor/CSharpOutputVisitor.cs
index 769c4e09..683a632e 100644
--- a/ICSharpCode.NRefactory.CSharp/OutputVisitor/CSharpOutputVisitor.cs
+++ b/ICSharpCode.NRefactory.CSharp/OutputVisitor/CSharpOutputVisitor.cs
@@ -2146,6 +2146,9 @@ namespace ICSharpCode.NRefactory.CSharp
 		public virtual void VisitComposedType(ComposedType composedType)
 		{
 			StartNode(composedType);
+			if (composedType.HasRefSpecifier) {
+				WriteKeyword(ComposedType.RefRole);
+			}
 			composedType.BaseType.AcceptVisitor(this);
 			if (composedType.HasNullableSpecifier) {
 				WriteToken(ComposedType.NullableRole);
diff --git a/ICSharpCode.NRefactory.CSharp/Refactoring/TypeSystemAstBuilder.cs b/ICSharpCode.NRefactory.CSharp/Refactoring/TypeSystemAstBuilder.cs
index 5badd658..476ab8dc 100644
--- a/ICSharpCode.NRefactory.CSharp/Refactoring/TypeSystemAstBuilder.cs
+++ b/ICSharpCode.NRefactory.CSharp/Refactoring/TypeSystemAstBuilder.cs
@@ -217,6 +217,8 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 					return ConvertType(typeWithElementType.ElementType).MakePointerType();
 				} else if (typeWithElementType is ArrayType) {
 					return ConvertType(typeWithElementType.ElementType).MakeArrayType(((ArrayType)type).Dimensions);
+				} else if (typeWithElementType is ByReferenceType) {
+					return ConvertType(typeWithElementType.ElementType).MakeRefType();
 				} else {
 					// e.g. ByReferenceType; not supported as type in C#
 					return ConvertType(typeWithElementType.ElementType);
@@ -584,7 +586,12 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			if (ShowAttributes) {
 				decl.Attributes.AddRange (parameter.Attributes.Select ((a) => new AttributeSection (ConvertAttribute (a))));
 			}
-			decl.Type = ConvertType(parameter.Type);
+			if (parameter.Type.Kind == TypeKind.ByReference) {
+				// avoid 'out ref'
+				decl.Type = ConvertType(((ByReferenceType)parameter.Type).ElementType);
+			} else {
+				decl.Type = ConvertType(parameter.Type);
+			}
 			if (this.ShowParameterNames) {
 				decl.Name = parameter.Name;
 			}
diff --git a/ICSharpCode.NRefactory.CSharp/Resolver/ResolveVisitor.cs b/ICSharpCode.NRefactory.CSharp/Resolver/ResolveVisitor.cs
index 340b290e..27a28660 100644
--- a/ICSharpCode.NRefactory.CSharp/Resolver/ResolveVisitor.cs
+++ b/ICSharpCode.NRefactory.CSharp/Resolver/ResolveVisitor.cs
@@ -3379,6 +3379,9 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			foreach (var a in composedType.ArraySpecifiers.Reverse()) {
 				t = new ArrayType(resolver.Compilation, t, a.Dimensions);
 			}
+			if (composedType.HasRefSpecifier) {
+				t = new ByReferenceType(t);
+			}
 			return new TypeResolveResult(t);
 		}
 		#endregion