//
// Copyright 2001, 2002, 2003 Ximian, Inc.
// Copyright 2003-2008 Novell, Inc.
+// Copyright 2011 Xamarin Inc (http://www.xamarin.com)
//
using System;
if (array.Element == arg_type)
return true;
+ //
+ // Reject conversion from T[] to IList<U> even if T has U dependency
+ //
+ if (arg_type.IsGenericParameter)
+ return false;
+
if (isExplicit)
return ExplicitReferenceConversionExists (array.Element, arg_type);
{
TypeSpec expr_type = expr.Type;
- if (expr_type == null && expr.eclass == ExprClass.MethodGroup){
- // if we are a method group, emit a warning
-
- expr.Emit (null);
- }
-
if (expr_type.Kind == MemberKind.TypeParameter)
return ImplicitTypeParameterConversion (expr, (TypeParameterSpec) expr.Type, target_type);
return EmptyCast.Create (expr, target_type);
}
- return ImplicitBoxingConversion (expr, expr_type, target_type);
+ return null;
}
//
- // 6.1.6 Implicit reference conversions
+ // Implicit reference conversions
//
public static bool ImplicitReferenceConversionExists (TypeSpec expr_type, TypeSpec target_type)
{
+ return ImplicitReferenceConversionExists (expr_type, target_type, true);
+ }
+
+ public static bool ImplicitReferenceConversionExists (TypeSpec expr_type, TypeSpec target_type, bool refOnlyTypeParameter)
+ {
+ // It's here only to speed things up
if (target_type.IsStruct)
return false;
- // from the null type to any reference-type.
- if (expr_type == InternalType.NullLiteral)
- return true;
+ switch (expr_type.Kind) {
+ case MemberKind.TypeParameter:
+ return ImplicitTypeParameterConversion (null, (TypeParameterSpec) expr_type, target_type) != null &&
+ (!refOnlyTypeParameter || TypeSpec.IsReferenceType (expr_type));
- if (expr_type.IsGenericParameter)
- return ImplicitTypeParameterConversion (null, (TypeParameterSpec) expr_type, target_type) != null;
-
- // This code is kind of mirrored inside ImplicitStandardConversionExists
- // with the small distinction that we only probe there
- //
- // Always ensure that the code here and there is in sync
+ case MemberKind.Class:
+ //
+ // From any class-type to dynamic (+object to speed up common path)
+ //
+ if (target_type.BuiltinType == BuiltinTypeSpec.Type.Object || target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
+ return true;
- // from any class-type S to any interface-type T.
- if (target_type.IsInterface) {
- if (expr_type.ImplementsInterface (target_type, true)){
- return !TypeManager.IsValueType (expr_type);
- }
- }
+ if (target_type.IsClass) {
+ //
+ // Identity conversion, including dynamic erasure
+ //
+ if (TypeSpecComparer.IsEqual (expr_type, target_type))
+ return true;
- //
- // Implicit reference conversions (no-boxing) to object or dynamic
- //
- if (target_type.BuiltinType == BuiltinTypeSpec.Type.Object || target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
- switch (expr_type.Kind) {
- case MemberKind.Class:
- case MemberKind.Interface:
- case MemberKind.Delegate:
- case MemberKind.ArrayType:
- return true;
+ //
+ // From any class-type S to any class-type T, provided S is derived from T
+ //
+ return TypeSpec.IsBaseClass (expr_type, target_type, true);
}
- return expr_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
- }
-
- if (expr_type == target_type || TypeSpec.IsBaseClass (expr_type, target_type, true)) {
- if (TypeManager.IsGenericParameter (expr_type))
- return false;
+ //
+ // From any class-type S to any interface-type T, provided S implements T
+ //
+ if (target_type.IsInterface)
+ return expr_type.ImplementsInterface (target_type, true);
- if (TypeManager.IsValueType (expr_type))
- return false;
+ return false;
- // Array type variance conversion
- //if (target_type.IsArray != expr_type.IsArray)
- // return false;
+ case MemberKind.ArrayType:
+ //
+ // Identity array conversion
+ //
+ if (expr_type == target_type)
+ return true;
- return true;
- }
+ //
+ // From any array-type to System.Array
+ //
+ switch (target_type.BuiltinType) {
+ case BuiltinTypeSpec.Type.Array:
+ case BuiltinTypeSpec.Type.Object:
+ case BuiltinTypeSpec.Type.Dynamic:
+ return true;
+ }
- var expr_type_array = expr_type as ArrayContainer;
- if (expr_type_array != null) {
+ var expr_type_array = (ArrayContainer) expr_type;
var target_type_array = target_type as ArrayContainer;
- // from an array-type S to an array-type of type T
+
+ //
+ // From an array-type S to an array-type of type T
+ //
if (target_type_array != null && expr_type_array.Rank == target_type_array.Rank) {
//
- // Both SE and TE are reference-types
+ // Both SE and TE are reference-types. TE check is defered
+ // to ImplicitReferenceConversionExists
//
TypeSpec expr_element_type = expr_type_array.Element;
- if (!TypeManager.IsReferenceType (expr_element_type))
- return false;
-
- TypeSpec target_element_type = target_type_array.Element;
- if (!TypeManager.IsReferenceType (target_element_type))
+ if (!TypeSpec.IsReferenceType (expr_element_type))
return false;
//
// An implicit reference conversion exists from SE to TE
//
- return ImplicitReferenceConversionExists (expr_element_type, target_element_type);
+ return ImplicitReferenceConversionExists (expr_element_type, target_type_array.Element);
}
- // from an array-type to System.Array
- if (target_type.BuiltinType == BuiltinTypeSpec.Type.Array)
+ //
+ // From any array-type to the interfaces it implements
+ //
+ if (target_type.IsInterface) {
+ if (expr_type.ImplementsInterface (target_type, false))
+ return true;
+
+ // from an array-type of type T to IList<T>
+ if (ArrayToIList (expr_type_array, target_type, false))
+ return true;
+ }
+
+ return false;
+
+ case MemberKind.Delegate:
+ //
+ // From any delegate-type to System.Delegate (and its base types)
+ //
+ switch (target_type.BuiltinType) {
+ case BuiltinTypeSpec.Type.Delegate:
+ case BuiltinTypeSpec.Type.MulticastDelegate:
+ case BuiltinTypeSpec.Type.Object:
+ case BuiltinTypeSpec.Type.Dynamic:
return true;
+ }
- // from an array-type of type T to IList<T>
- if (ArrayToIList (expr_type_array, target_type, false))
+ //
+ // Identity conversion, including dynamic erasure
+ //
+ if (TypeSpecComparer.IsEqual (expr_type, target_type))
return true;
- return false;
- }
+ //
+ // From any delegate-type to the interfaces it implements
+ // From any reference-type to an delegate type if is variance-convertible
+ //
+ return expr_type.ImplementsInterface (target_type, false) || TypeSpecComparer.Variant.IsEqual (expr_type, target_type);
- if (TypeSpecComparer.IsEqual (expr_type, target_type))
- return true;
+ case MemberKind.Interface:
+ //
+ // Identity conversion, including dynamic erasure
+ //
+ if (TypeSpecComparer.IsEqual (expr_type, target_type))
+ return true;
- if (TypeSpecComparer.Variant.IsEqual (expr_type, target_type))
- return true;
+ //
+ // From any interface type S to interface-type T
+ // From any reference-type to an interface if is variance-convertible
+ //
+ if (target_type.IsInterface)
+ return TypeSpecComparer.Variant.IsEqual (expr_type, target_type) || expr_type.ImplementsInterface (target_type, true);
- // from any interface type S to interface-type T.
- if (expr_type.IsInterface && target_type.IsInterface) {
- return expr_type.ImplementsInterface (target_type, true);
+ return target_type.BuiltinType == BuiltinTypeSpec.Type.Object || target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
}
- // from any delegate type to System.Delegate
- if (target_type.BuiltinType == BuiltinTypeSpec.Type.Delegate &&
- (expr_type.BuiltinType == BuiltinTypeSpec.Type.Delegate || expr_type.IsDelegate))
- return true;
+ //
+ // from the null literal to any reference-type.
+ //
+ if (expr_type == InternalType.NullLiteral) {
+ // Exlude internal compiler types
+ if (target_type.Kind == MemberKind.InternalCompilerType)
+ return target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
+
+ return TypeSpec.IsReferenceType (target_type);
+ }
return false;
}
{
switch (target_type.BuiltinType) {
//
- // From any value-type to the type object.
+ // From any non-nullable-value-type to the type object and dynamic
//
case BuiltinTypeSpec.Type.Object:
case BuiltinTypeSpec.Type.Dynamic:
- //
- // A pointer type cannot be converted to object
- //
- if (expr_type.IsPointer)
- return null;
-
- if (!TypeManager.IsValueType (expr_type))
- return null;
-
- return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
-
//
- // From any value-type to the type System.ValueType.
+ // From any non-nullable-value-type to the type System.ValueType
//
case BuiltinTypeSpec.Type.ValueType:
- if (!TypeManager.IsValueType (expr_type))
+ //
+ // No ned to check for nullable type as underlying type is always convertible
+ //
+ if (!TypeSpec.IsValueType (expr_type))
return null;
return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
// the underlying type to the reference type
//
if (expr_type.IsNullableType) {
- if (!TypeManager.IsReferenceType (target_type))
+ if (!TypeSpec.IsReferenceType (target_type))
return null;
var res = ImplicitBoxingConversion (expr, Nullable.NullableInfo.GetUnderlyingType (expr_type), target_type);
return res;
}
- if (TypeSpec.IsBaseClass (expr_type, target_type, false)) {
- //
- // Don't box same type arguments
- //
- if (TypeManager.IsGenericParameter (expr_type) && expr_type != target_type)
- return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
-
- return null;
- }
-
- // This code is kind of mirrored inside ImplicitStandardConversionExists
- // with the small distinction that we only probe there
//
- // Always ensure that the code here and there is in sync
-
- // from any class-type S to any interface-type T.
- if (target_type.IsInterface) {
- if (expr_type.ImplementsInterface (target_type, true) &&
- (TypeManager.IsGenericParameter (expr_type) || TypeManager.IsValueType (expr_type))) {
- return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
- }
+ // A value type has a boxing conversion to an interface type I if it has a boxing conversion
+ // to an interface or delegate type I0 and I0 is variance-convertible to I
+ //
+ if (target_type.IsInterface && TypeSpec.IsValueType (expr_type) && expr_type.ImplementsInterface (target_type, true)) {
+ return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
}
return null;
return null;
}
- /// <summary>
- /// Same as ImplicitStandardConversionExists except that it also looks at
- /// implicit user defined conversions - needed for overload resolution
- /// </summary>
+ //
+ // Full version of implicit conversion
+ //
public static bool ImplicitConversionExists (ResolveContext ec, Expression expr, TypeSpec target_type)
{
if (ImplicitStandardConversionExists (expr, target_type))
return ImplicitUserConversion (ec, expr, target_type, Location.Null) != null;
}
- /// <summary>
- /// Determines if a standard implicit conversion exists from
- /// expr_type to target_type
- ///
- /// </summary>
+ //
+ // Implicit standard conversion (only core conversions are used here)
+ //
public static bool ImplicitStandardConversionExists (Expression expr, TypeSpec target_type)
{
- TypeSpec expr_type = expr.Type;
+ //
+ // Identity conversions
+ // Implicit numeric conversions
+ // Implicit nullable conversions
+ // Implicit reference conversions
+ // Boxing conversions
+ // Implicit constant expression conversions
+ // Implicit conversions involving type parameters
+ //
- NullLiteral nl = expr as NullLiteral;
- if (nl != null)
- return nl.ConvertImplicitly (target_type) != null;
+ TypeSpec expr_type = expr.Type;
if (expr_type == target_type)
return true;
- // Implicit dynamic conversion
- if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
- switch (target_type.Kind) {
- case MemberKind.ArrayType:
- case MemberKind.Class:
- case MemberKind.Struct:
- case MemberKind.Delegate:
- case MemberKind.Enum:
- case MemberKind.Interface:
- case MemberKind.TypeParameter:
- return true;
- }
-
- // dynamic to __arglist
- if (target_type == InternalType.Arglist)
- return true;
-
- return false;
- }
-
- if (target_type.IsNullableType) {
+ if (target_type.IsNullableType)
return ImplicitNulableConversion (null, expr, target_type) != null;
- }
- // First numeric conversions
if (ImplicitNumericConversion (null, expr_type, target_type) != null)
return true;
- if (ImplicitReferenceConversionExists (expr_type, target_type))
+ if (ImplicitReferenceConversionExists (expr_type, target_type, false))
return true;
if (ImplicitBoxingConversion (null, expr_type, target_type) != null)
return i.IsZeroInteger;
}
+ // Implicit dynamic conversion
+ if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
+ switch (target_type.Kind) {
+ case MemberKind.ArrayType:
+ case MemberKind.Class:
+ case MemberKind.Struct:
+ case MemberKind.Delegate:
+ case MemberKind.Enum:
+ case MemberKind.Interface:
+ case MemberKind.TypeParameter:
+ return true;
+ }
+
+ // dynamic to __arglist
+ if (target_type == InternalType.Arglist)
+ return true;
+
+ return false;
+ }
+
//
- // If `expr_type' implements `target_type' (which is an iface)
- // see TryImplicitIntConversion
+ // In an unsafe context implicit conversions is extended to include
//
- if (target_type.IsInterface && expr_type.ImplementsInterface (target_type, true))
- return true;
-
- if (target_type.IsPointer && expr_type.IsPointer && ((PointerContainer) target_type).Element.Kind == MemberKind.Void)
+ // From any pointer-type to the type void*
+ // From the null literal to any pointer-type.
+ //
+ // LAMESPEC: The specification claims this conversion is allowed in implicit conversion but
+ // in reality implicit standard conversion uses it
+ //
+ if (target_type.IsPointer && expr.Type.IsPointer && ((PointerContainer) target_type).Element.Kind == MemberKind.Void)
return true;
- if (TypeSpecComparer.IsEqual (expr_type, target_type))
+ //
+ // Struct identity conversion, including dynamic erasure
+ //
+ if (expr_type.IsStruct && TypeSpecComparer.IsEqual (expr_type, target_type))
return true;
return false;
/// Finds "most encompassed type" according to the spec (13.4.2)
/// amongst the methods in the MethodGroupExpr
/// </summary>
- public static TypeSpec FindMostEncompassedType (IEnumerable<TypeSpec> types)
+ public static TypeSpec FindMostEncompassedType (IList<TypeSpec> types)
{
TypeSpec best = null;
EmptyExpression expr;
return best;
}
- /// <summary>
- /// Finds "most encompassing type" according to the spec (13.4.2)
- /// amongst the types in the given set
- /// </summary>
+ //
+ // Finds the most encompassing type (type into which all other
+ // types can convert to) amongst the types in the given set
+ //
static TypeSpec FindMostEncompassingType (IList<TypeSpec> types)
{
- TypeSpec best = null;
-
if (types.Count == 0)
return null;
if (types.Count == 1)
return types [0];
- foreach (TypeSpec t in types) {
- if (best == null) {
- best = t;
- continue;
- }
+ TypeSpec best = null;
+ for (int i = 0; i < types.Count; ++i) {
+ int ii = 0;
+ for (; ii < types.Count; ++ii) {
+ if (ii == i)
+ continue;
- var expr = new EmptyExpression (best);
- if (ImplicitStandardConversionExists (expr, t))
- best = t;
- }
+ var expr = new EmptyExpression (types[ii]);
+ if (!ImplicitStandardConversionExists (expr, types [i])) {
+ ii = 0;
+ break;
+ }
+ }
- foreach (TypeSpec t in types) {
- if (best == t)
+ if (ii == 0)
continue;
- var expr = new EmptyExpression (best);
- if (!ImplicitStandardConversionExists (expr, best)) {
- best = null;
- break;
+ if (best == null) {
+ best = types[i];
+ continue;
}
+
+ // Indicates multiple best types
+ return InternalType.FakeInternalType;
}
return best;
if (source_type.IsNullableType) {
// No implicit conversion S? -> T for non-reference types
- if (implicitOnly && !TypeManager.IsReferenceType (target_type) && !target_type.IsNullableType)
+ if (implicitOnly && !TypeSpec.IsReferenceType (target_type) && !target_type.IsNullableType)
return null;
source_type_expr = Nullable.Unwrap.Create (source);
"Ambiguous user defined operators `{0}' and `{1}' when converting from `{2}' to `{3}'",
ambig_arg.GetSignatureForError (), most_specific_operator.GetSignatureForError (),
source.Type.GetSignatureForError (), target.GetSignatureForError ());
+
+ return ErrorExpression.Instance;
}
}
// Source expression is of nullable type, lift the result in the case it's null and
// not nullable/lifted user operator is used
//
- if (source_type_expr is Nullable.Unwrap && !s_x.IsNullableType && (TypeManager.IsReferenceType (target) || target_type != target))
+ if (source_type_expr is Nullable.Unwrap && !s_x.IsNullableType && (TypeSpec.IsReferenceType (target) || target_type != target))
source = new Nullable.Lifted (source, source_type_expr, target).Resolve (ec);
else if (target_type != target)
source = Nullable.Wrap.Create (source, target);
static Expression ImplicitConversionStandard (ResolveContext ec, Expression expr, TypeSpec target_type, Location loc, bool explicit_cast)
{
if (expr.eclass == ExprClass.MethodGroup){
- if (!TypeManager.IsDelegateType (target_type)){
+ if (!target_type.IsDelegate){
return null;
}
if (e != null)
return e;
- if (expr is IntegralConstant && TypeManager.IsEnumType (target_type)){
+ e = ImplicitBoxingConversion (expr, expr_type, target_type);
+ if (e != null)
+ return e;
+
+ if (expr is IntegralConstant && target_type.IsEnum){
var i = (IntegralConstant) expr;
//
// LAMESPEC: csc allows any constant like 0 values to be converted, including const float f = 0.0
if (expr_type == InternalType.Arglist && target_type == ec.Module.PredefinedTypes.ArgIterator.TypeSpec)
return expr;
- if (TypeSpecComparer.IsEqual (expr_type, target_type)) {
- if (expr_type == target_type)
- return expr;
-
- return EmptyCast.Create (expr, target_type);
- }
+ //
+ // dynamic erasure conversion on value types
+ //
+ if (expr_type.IsStruct && TypeSpecComparer.IsEqual (expr_type, target_type))
+ return expr_type == target_type ? expr : EmptyCast.Create (expr, target_type);
return null;
}
if (source_array.Rank == target_array.Rank) {
source_type = source_array.Element;
- if (!TypeManager.IsReferenceType (source_type))
+ if (!TypeSpec.IsReferenceType (source_type))
return null;
var target_element = target_array.Element;
- if (!TypeManager.IsReferenceType (target_element))
+ if (!TypeSpec.IsReferenceType (target_element))
return null;
if (ExplicitReferenceConversionExists (source_type, target_element))
//
// From System delegate to any delegate-type
//
- if (source_type.BuiltinType == BuiltinTypeSpec.Type.Delegate && TypeManager.IsDelegateType (target_type))
+ if (source_type.BuiltinType == BuiltinTypeSpec.Type.Delegate && target_type.IsDelegate)
return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
//
//
//If TP is contravariant, both are either identical or reference types
//
- if (TypeManager.IsReferenceType (targs_src[i]) && TypeManager.IsReferenceType (targs_dst[i]))
+ if (TypeSpec.IsReferenceType (targs_src[i]) && TypeSpec.IsReferenceType (targs_dst[i]))
continue;
}
if (ne != null)
return ne;
- if (TypeManager.IsEnumType (expr_type)) {
- TypeSpec real_target = TypeManager.IsEnumType (target_type) ? EnumSpec.GetUnderlyingType (target_type) : target_type;
+ if (expr_type.IsEnum) {
+ TypeSpec real_target = target_type.IsEnum ? EnumSpec.GetUnderlyingType (target_type) : target_type;
Expression underlying = EmptyCast.Create (expr, EnumSpec.GetUnderlyingType (expr_type));
if (underlying.Type == real_target)
ne = underlying;
return ne != null ? EmptyCast.Create (ne, target_type) : null;
}
- if (TypeManager.IsEnumType (target_type)) {
+ if (target_type.IsEnum) {
//
// System.Enum can be unboxed to any enum-type
//
if (expr_type.BuiltinType == BuiltinTypeSpec.Type.Enum)
return new UnboxCast (expr, target_type);
- TypeSpec real_target = TypeManager.IsEnumType (target_type) ? EnumSpec.GetUnderlyingType (target_type) : target_type;
+ TypeSpec real_target = target_type.IsEnum ? EnumSpec.GetUnderlyingType (target_type) : target_type;
if (expr_type == real_target)
return EmptyCast.Create (expr, target_type);
projects / mono.git / blobdiff