Add support for unbound generic parameters

5 files changed, 103 insertions, 20 deletions

diff --git a/Mono.Cecil/AssemblyReader.cs b/Mono.Cecil/AssemblyReader.cs
index d7007e1..f412d74 100644
--- a/Mono.Cecil/AssemblyReader.cs
+++ b/Mono.Cecil/AssemblyReader.cs
@@ -1798,11 +1798,11 @@ namespace Mono.Cecil {
 			Range range;
 			if (!metadata.TryGetGenericParameterRange (provider, out range)
 				|| !MoveTo (Table.GenericParam, range.Start))
-				return new Collection<GenericParameter> ();
+				return new GenericParameterCollection (provider);
 
 			metadata.RemoveGenericParameterRange (provider);
 
-			var generic_parameters = new Collection<GenericParameter> ((int) range.Length);
+			var generic_parameters = new GenericParameterCollection (provider, (int) range.Length);
 
 			for (uint i = 0; i < range.Length; i++) {
 				ReadUInt16 (); // index
@@ -2647,9 +2647,10 @@ namespace Mono.Cecil {
 		GenericParameter GetGenericParameter (GenericParameterType type, uint var)
 		{
 			var context = reader.context;
+			int index = (int) var;
 
 			if (context == null)
-				throw new NotSupportedException ();
+				return GetUnboundGenericParameter (type, index);
 
 			IGenericParameterProvider provider;
 
@@ -2664,14 +2665,20 @@ namespace Mono.Cecil {
 				throw new NotSupportedException ();
 			}
 
-			int index = (int) var;
-
 			if (!context.IsDefinition)
 				CheckGenericContext (provider, index);
 
+			if (index >= provider.GenericParameters.Count)
+				return GetUnboundGenericParameter (type, index);
+
 			return provider.GenericParameters [index];
 		}
 
+		static GenericParameter GetUnboundGenericParameter (GenericParameterType type, int index)
+		{
+			return new GenericParameter (index, type);
+		}
+
 		static void CheckGenericContext (IGenericParameterProvider owner, int index)
 		{
 			var owner_parameters = owner.GenericParameters;
diff --git a/Mono.Cecil/GenericParameter.cs b/Mono.Cecil/GenericParameter.cs
index 2d0c190..664f00a 100644
--- a/Mono.Cecil/GenericParameter.cs
+++ b/Mono.Cecil/GenericParameter.cs
@@ -36,7 +36,9 @@ namespace Mono.Cecil {
 
 	public sealed class GenericParameter : TypeReference, ICustomAttributeProvider {
 
-		readonly IGenericParameterProvider owner;
+		internal int position;
+		internal GenericParameterType type;
+		internal IGenericParameterProvider owner;
 
 		ushort attributes;
 		Collection<TypeReference> constraints;
@@ -48,12 +50,11 @@ namespace Mono.Cecil {
 		}
 
 		public int Position {
-			get {
-				if (owner == null)
-					return -1;
+			get { return position; }
+		}
 
-				return owner.GenericParameters.IndexOf (this);
-			}
+		public GenericParameterType Type {
+			get { return type; }
 		}
 
 		public IGenericParameterProvider Owner {
@@ -99,15 +100,17 @@ namespace Mono.Cecil {
 
 		public override IMetadataScope Scope {
 			get {
-				if (owner.GenericParameterType == GenericParameterType.Method)
-					return ((MethodReference) owner).DeclaringType.Scope;
+				if (owner == null)
+					return null;
 
-				return ((TypeReference) owner).Scope;
+				return owner.GenericParameterType == GenericParameterType.Method
+					? ((MethodReference) owner).DeclaringType.Scope
+					: ((TypeReference) owner).Scope;
 			}
 		}
 
 		public override ModuleDefinition Module {
-			get { return ((MemberReference) owner).Module; }
+			get { return owner != null ? owner.Module : null; }
 		}
 
 		public override string Name {
@@ -115,7 +118,7 @@ namespace Mono.Cecil {
 				if (!string.IsNullOrEmpty (base.Name))
 					return base.Name;
 
-				return base.Name = (owner.GenericParameterType == GenericParameterType.Type ? "!" : "!!") + Position;
+				return base.Name = (type == GenericParameterType.Method ? "!!" : "!") + position;
 			}
 		}
 
@@ -185,8 +188,30 @@ namespace Mono.Cecil {
 			if (owner == null)
 				throw new ArgumentNullException ();
 
+			this.position = -1;
 			this.owner = owner;
-			this.etype = owner.GenericParameterType == GenericParameterType.Type ? ElementType.Var : ElementType.MVar;
+			this.type = owner.GenericParameterType;
+			this.etype = ConvertGenericParameterType (this.type);
+		}
+
+		public GenericParameter (int position, GenericParameterType type)
+			: base (string.Empty, string.Empty)
+		{
+			this.position = position;
+			this.type = type;
+			this.etype = ConvertGenericParameterType (type);
+		}
+
+		static ElementType ConvertGenericParameterType (GenericParameterType type)
+		{
+			switch (type) {
+			case GenericParameterType.Type:
+				return ElementType.Var;
+			case GenericParameterType.Method:
+				return ElementType.MVar;
+			}
+
+			throw new ArgumentOutOfRangeException ();
 		}
 
 		public override TypeDefinition Resolve ()
@@ -194,4 +219,55 @@ namespace Mono.Cecil {
 			return null;
 		}
 	}
+
+	sealed class GenericParameterCollection : Collection<GenericParameter> {
+
+		readonly IGenericParameterProvider owner;
+
+		internal GenericParameterCollection (IGenericParameterProvider owner)
+		{
+			this.owner = owner;
+		}
+
+		internal GenericParameterCollection (IGenericParameterProvider owner, int capacity)
+			: base (capacity)
+		{
+			this.owner = owner;
+		}
+
+		protected override void OnAdd (GenericParameter item, int index)
+		{
+			UpdateGenericParameter (item, index);
+		}
+
+		protected override void OnInsert (GenericParameter item, int index)
+		{
+			UpdateGenericParameter (item, index);
+
+			for (int i = index; i < size; i++)
+				items[i].position = i + 1;
+		}
+
+		protected override void OnSet (GenericParameter item, int index)
+		{
+			UpdateGenericParameter (item, index);
+		}
+
+		void UpdateGenericParameter (GenericParameter item, int index)
+		{
+			item.owner = owner;
+			item.position = index;
+			item.type = owner.GenericParameterType;
+		}
+
+		protected override void OnRemove (GenericParameter item, int index)
+		{
+			item.owner = null;
+			item.position = -1;
+			item.type = GenericParameterType.Type;
+
+			for (int i = index + 1; i < size; i++)
+				items[i].position = i - 1;
+		}
+	}
 }
diff --git a/Mono.Cecil/IGenericParameterProvider.cs b/Mono.Cecil/IGenericParameterProvider.cs
index 7f499bb..d41b7f6 100644
--- a/Mono.Cecil/IGenericParameterProvider.cs
+++ b/Mono.Cecil/IGenericParameterProvider.cs
@@ -67,7 +67,7 @@ namespace Mono.Cecil {
 		{
 			return module.HasImage ()
 				? module.Read (self, (provider, reader) => reader.ReadGenericParameters (provider))
-				: new Collection<GenericParameter> ();
+				: new GenericParameterCollection (self);
 		}
 	}
 }
diff --git a/Mono.Cecil/MethodReference.cs b/Mono.Cecil/MethodReference.cs
index 21de336..0adab45 100644
--- a/Mono.Cecil/MethodReference.cs
+++ b/Mono.Cecil/MethodReference.cs
@@ -99,7 +99,7 @@ namespace Mono.Cecil {
 				if (generic_parameters != null)
 					return generic_parameters;
 
-				return generic_parameters = new Collection<GenericParameter> ();
+				return generic_parameters = new GenericParameterCollection (this);
 			}
 		}
 
diff --git a/Mono.Cecil/TypeReference.cs b/Mono.Cecil/TypeReference.cs
index f486124..757c83a 100644
--- a/Mono.Cecil/TypeReference.cs
+++ b/Mono.Cecil/TypeReference.cs
@@ -135,7 +135,7 @@ namespace Mono.Cecil {
 				if (generic_parameters != null)
 					return generic_parameters;
 
-				return generic_parameters = new Collection<GenericParameter> ();
+				return generic_parameters = new GenericParameterCollection (this);
 			}
 		}