Use TypeManager.GetInterfaces().
[mono.git] / mcs / gmcs / convert.cs
index f234847fd315573600936f8f38095bb10f8859d0..637c4150f718621bebbb5137db0efde148a3150d 100644 (file)
@@ -59,14 +59,14 @@ namespace Mono.CSharp {
                                if (TypeManager.IsValueType (expr_type))
                                        return new BoxedCast (expr);
                                if (expr is NullLiteral)
-                                       return new BoxedCast (expr);
-                       } else if (expr_type.IsSubclassOf (target_type)) {
+                                       return new NullCast (expr, target_type);
+                       } else if (TypeManager.IsSubclassOf (expr_type, target_type)) {
                                //
                                // Special case: enumeration to System.Enum.
                                // System.Enum is not a value type, it is a class, so we need
                                // a boxing conversion
                                //
-                               if (expr_type.IsEnum)
+                               if (expr_type.IsEnum || expr_type.IsGenericParameter)
                                        return new BoxedCast (expr);
 
                                return new EmptyCast (expr, target_type);
@@ -89,10 +89,15 @@ namespace Mono.CSharp {
                                // from any class-type S to any interface-type T.
                                if (target_type.IsInterface) {
                                        if (TypeManager.ImplementsInterface (expr_type, target_type)){
-                                               if (expr_type.IsClass)
+                                               if (expr_type.IsGenericParameter)
+                                                       return new BoxedCast (expr, target_type);
+                                               else if (expr_type.IsClass)
                                                        return new EmptyCast (expr, target_type);
-                                               else if (TypeManager.IsValueType (expr_type))
+                                               else if (TypeManager.IsValueType (expr_type) ||
+                                                        TypeManager.IsEnumType (expr_type))
                                                        return new BoxedCast (expr, target_type);
+                                               else
+                                                       return new EmptyCast (expr, target_type);
                                        }
                                }
 
@@ -130,35 +135,20 @@ namespace Mono.CSharp {
                                
                                // from any delegate type to System.Delegate
                                if ((expr_type == TypeManager.delegate_type || 
-                                    expr_type.IsSubclassOf (TypeManager.delegate_type)) &&
+                                    TypeManager.IsDelegateType (expr_type)) &&
                                    target_type == TypeManager.delegate_type)
                                        return new EmptyCast (expr, target_type);
                                        
                                // from any array-type or delegate type into System.ICloneable.
                                if (expr_type.IsArray ||
                                    expr_type == TypeManager.delegate_type ||
-                                   expr_type.IsSubclassOf (TypeManager.delegate_type))
+                                   TypeManager.IsDelegateType (expr_type))
                                        if (target_type == TypeManager.icloneable_type)
                                                return new EmptyCast (expr, target_type);
 
                                // from a generic type definition to a generic instance.
-                               if ((expr_type is TypeBuilder) && expr_type.IsGenericTypeDefinition &&
-                                   target_type.IsGenericInstance) {
-                                       if (expr_type != target_type.GetGenericTypeDefinition ())
-                                               return null;
-
-                                       Type[] gparams = expr_type.GetGenericArguments ();
-                                       Type[] tparams = target_type.GetGenericArguments ();
-
-                                       if (gparams.Length != tparams.Length)
-                                               return null;
-
-                                       for (int i = 0; i < gparams.Length; i++)
-                                               if (gparams [i] != tparams [i])
-                                                       return null;
-
+                               if (TypeManager.IsEqualGenericType (expr_type, target_type))
                                        return new EmptyCast (expr, target_type);
-                               }
                                
                                return null;
 
@@ -182,9 +172,9 @@ namespace Mono.CSharp {
                                if (expr_type.IsClass || TypeManager.IsValueType (expr_type) ||
                                    expr_type.IsInterface || expr_type == TypeManager.enum_type)
                                        return true;
-                       } else if (expr_type.IsSubclassOf (target_type)) {
+                       } else if (TypeManager.IsSubclassOf (expr_type, target_type))
                                return true;
-                       else {
+                       else {
                                // Please remember that all code below actually comes
                                // from ImplicitReferenceConversion so make sure code remains in sync
                                
@@ -224,7 +214,7 @@ namespace Mono.CSharp {
                                
                                // from any delegate type to System.Delegate
                                if ((expr_type == TypeManager.delegate_type ||
-                                    expr_type.IsSubclassOf (TypeManager.delegate_type)) &&
+                                    TypeManager.IsDelegateType (expr_type)) &&
                                    target_type == TypeManager.delegate_type)
                                        if (target_type.IsAssignableFrom (expr_type))
                                                return true;
@@ -232,7 +222,7 @@ namespace Mono.CSharp {
                                // from any array-type or delegate type into System.ICloneable.
                                if (expr_type.IsArray ||
                                    expr_type == TypeManager.delegate_type ||
-                                   expr_type.IsSubclassOf (TypeManager.delegate_type))
+                                   TypeManager.IsDelegateType (expr_type))
                                        if (target_type == TypeManager.icloneable_type)
                                                return true;
                                
@@ -242,23 +232,8 @@ namespace Mono.CSharp {
                                        return true;
 
                                // from a generic type definition to a generic instance.
-                               if ((expr_type is TypeBuilder) && expr_type.IsGenericTypeDefinition &&
-                                   target_type.IsGenericInstance) {
-                                       if (expr_type != target_type.GetGenericTypeDefinition ())
-                                               return false;
-
-                                       Type[] gparams = expr_type.GetGenericArguments ();
-                                       Type[] tparams = target_type.GetGenericArguments ();
-
-                                       if (gparams.Length != tparams.Length)
-                                               return false;
-
-                                       for (int i = 0; i < gparams.Length; i++)
-                                               if (gparams [i] != tparams [i])
-                                                       return false;
-
+                               if (TypeManager.IsEqualGenericType (expr_type, target_type))
                                        return true;
-                               }
                        }
                        return false;
                }
@@ -273,7 +248,7 @@ namespace Mono.CSharp {
                                                                    Type target_type, Location loc)
                {
                        Type expr_type = expr.Type;
-                       
+
                        //
                        // Attempt to do the implicit constant expression conversions
 
@@ -1030,7 +1005,6 @@ namespace Mono.CSharp {
                static public Expression ImplicitConversion (EmitContext ec, Expression expr,
                                                             Type target_type, Location loc)
                {
-                       Type expr_type = expr.Type;
                        Expression e;
 
                        if (target_type == null)
@@ -1064,6 +1038,18 @@ namespace Mono.CSharp {
                        Type expr_type = expr.Type;
                        Expression e;
 
+                       if (expr.eclass == ExprClass.MethodGroup){
+                               if (!TypeManager.IsDelegateType (target_type)){
+                                       Report.Error (428, loc,
+                                                     String.Format (
+                                                          "Cannot convert method group to `{0}', since it is not a delegate",
+                                                          TypeManager.CSharpName (target_type)));
+                                       return null;
+                               }
+
+                               return ImplicitDelegateCreation.Create (ec, (MethodGroupExpr) expr, target_type, loc);
+                       }
+
                        if (expr_type.Equals (target_type) && !(expr is NullLiteral))
                                return expr;
 
@@ -1124,7 +1110,7 @@ namespace Mono.CSharp {
                                if (value >= SByte.MinValue && value <= SByte.MaxValue)
                                        return new SByteConstant ((sbyte) value);
                        } else if (target_type == TypeManager.byte_type){
-                               if (Byte.MinValue >= 0 && value <= Byte.MaxValue)
+                               if (value >= Byte.MinValue && value <= Byte.MaxValue)
                                        return new ByteConstant ((byte) value);
                        } else if (target_type == TypeManager.short_type){
                                if (value >= Int16.MinValue && value <= Int16.MaxValue)
@@ -1195,6 +1181,13 @@ namespace Mono.CSharp {
                                              "float type, use F suffix to create a float literal");
                        }
 
+                       if (source is Constant){
+                               Constant c = (Constant) source;
+
+                               Expression.Error_ConstantValueCannotBeConverted (loc, c.AsString (), target_type);
+                               return null;
+                       }
+                       
                        Error_CannotImplicitConversion (loc, source.Type, target_type);
 
                        return null;
@@ -1422,11 +1415,18 @@ namespace Mono.CSharp {
                /// </summary>
                public static bool ExplicitReferenceConversionExists (Type source_type, Type target_type)
                {
+                       bool target_is_type_param = target_type.IsGenericParameter;
                        bool target_is_value_type = target_type.IsValueType;
                        
                        if (source_type == target_type)
                                return true;
-                       
+
+                       //
+                       // From object to a generic parameter
+                       //
+                       if (source_type == TypeManager.object_type && target_is_type_param)
+                               return true;
+
                        //
                        // From object to any reference type
                        //
@@ -1436,14 +1436,14 @@ namespace Mono.CSharp {
                        //
                        // From any class S to any class-type T, provided S is a base class of T
                        //
-                       if (target_type.IsSubclassOf (source_type))
+                       if (TypeManager.IsSubclassOf (target_type, source_type))
                                return true;
 
                        //
                        // From any interface type S to any interface T provided S is not derived from T
                        //
                        if (source_type.IsInterface && target_type.IsInterface){
-                               if (!target_type.IsSubclassOf (source_type))
+                               if (!TypeManager.IsSubclassOf (target_type, source_type))
                                        return true;
                        }
                            
@@ -1495,7 +1495,7 @@ namespace Mono.CSharp {
                        // From System delegate to any delegate-type
                        //
                        if (source_type == TypeManager.delegate_type &&
-                           target_type.IsSubclassOf (TypeManager.delegate_type))
+                           TypeManager.IsDelegateType (target_type))
                                return true;
 
                        //
@@ -1515,19 +1515,33 @@ namespace Mono.CSharp {
                static Expression ExplicitReferenceConversion (Expression source, Type target_type)
                {
                        Type source_type = source.Type;
+                       bool target_is_type_param = target_type.IsGenericParameter;
                        bool target_is_value_type = target_type.IsValueType;
 
+                       //
+                       // From object to a generic parameter
+                       //
+                       if (source_type == TypeManager.object_type && target_is_type_param)
+                               return new UnboxCast (source, target_type);
+
                        //
                        // From object to any reference type
                        //
                        if (source_type == TypeManager.object_type && !target_is_value_type)
                                return new ClassCast (source, target_type);
 
+                       //
+                       // Unboxing conversion.
+                       //
+                       if (((source_type == TypeManager.enum_type &&
+                               !(source is EmptyCast)) ||
+                               source_type == TypeManager.value_type) && target_is_value_type)
+                               return new UnboxCast (source, target_type);
 
                        //
                        // From any class S to any class-type T, provided S is a base class of T
                        //
-                       if (target_type.IsSubclassOf (source_type))
+                       if (TypeManager.IsSubclassOf (target_type, source_type))
                                return new ClassCast (source, target_type);
 
                        //
@@ -1539,7 +1553,7 @@ namespace Mono.CSharp {
                                else
                                        return new ClassCast (source, target_type);
                        }
-                           
+
                        //
                        // From any class type S to any interface T, provides S is not sealed
                        // and provided S does not implement T.
@@ -1598,7 +1612,7 @@ namespace Mono.CSharp {
                        // From System delegate to any delegate-type
                        //
                        if (source_type == TypeManager.delegate_type &&
-                           target_type.IsSubclassOf (TypeManager.delegate_type))
+                           TypeManager.IsDelegateType (target_type))
                                return new ClassCast (source, target_type);
 
                        //
@@ -1658,18 +1672,22 @@ namespace Mono.CSharp {
                        //
                        if (expr_type == TypeManager.object_type && target_type.IsValueType){
                                if (expr is NullLiteral){
-                                       Report.Error (37, loc, "Cannot convert null to value type `" +
-                                                      TypeManager.CSharpName (target_type) + "'");
-                                       return null;
+                                       //
+                                       // Skip the ExplicitReferenceConversion because we can not convert
+                                       // from Null to a ValueType, and ExplicitReference wont check against
+                                       // null literal explicitly
+                                       //
+                                       goto skip_explicit;
                                }
                                return new UnboxCast (expr, target_type);
+
                        }
 
-                       
                        ne = ExplicitReferenceConversion (expr, target_type);
                        if (ne != null)
                                return ne;
 
+               skip_explicit:
                        if (ec.InUnsafe){
                                if (target_type.IsPointer){
                                        if (expr_type.IsPointer)
@@ -1731,6 +1749,12 @@ namespace Mono.CSharp {
                        if (ne != null)
                                return ne;
 
+                       if (expr is NullLiteral){
+                               Report.Error (37, loc, "Cannot convert null to value type `" +
+                                             TypeManager.CSharpName (target_type) + "'");
+                               return null;
+                       }
+                               
                        Error_CannotConvertType (loc, original_expr_type, target_type);
                        return null;
                }