static class Convert {
static EmptyExpression MyEmptyExpr;
- static DoubleHash explicit_conv;
- static DoubleHash implicit_conv;
static Convert ()
{
public static void Reset ()
{
MyEmptyExpr = null;
- explicit_conv = new DoubleHash (100);
- implicit_conv = new DoubleHash (100);
}
//
static Expression ImplicitTypeParameterConversion (Expression expr, TypeSpec target_type)
{
var expr_type = (TypeParameterSpec) expr.Type;
+
//
- // From T to a type parameter U
+ // From T to a type parameter U, provided T depends on U
//
var ttype = target_type as TypeParameterSpec;
if (ttype != null) {
- if (expr_type.IsReferenceType && !ttype.IsReferenceType)
- return new BoxedCast (expr, target_type);
+ if (expr_type.TypeArguments != null) {
+ foreach (var targ in expr_type.TypeArguments) {
+ if (!TypeSpecComparer.Override.IsEqual (ttype, targ))
+ continue;
+
+ if (expr_type.IsReferenceType && !ttype.IsReferenceType)
+ return new BoxedCast (expr, target_type);
+
+ return new ClassCast (expr, target_type);
+ }
+ }
+
+ return null;
+ }
+
+ //
+ // LAMESPEC: From T to dynamic type
+ //
+ if (target_type == InternalType.Dynamic) {
+ if (expr_type.IsReferenceType)
+ return new ClassCast (expr, target_type);
- return new ClassCast (expr, target_type);
+ return new BoxedCast (expr, target_type);
}
//
return new BoxedCast (expr, target_type);
}
- var effective_ifaces = expr_type.Interfaces;
- if (effective_ifaces != null) {
- foreach (var t in effective_ifaces) {
- if (t == target_type || t.ImplementsInterface (target_type)) {
- if (expr_type.IsReferenceType)
- return new ClassCast (expr, target_type);
+ if (target_type.IsInterface && expr_type.IsConvertibleToInterface (target_type)) {
+ if (expr_type.IsReferenceType)
+ return new ClassCast (expr, target_type);
- return new BoxedCast (expr, target_type);
- }
- }
+ return new BoxedCast (expr, target_type);
}
return null;
{
var target_tp = target_type as TypeParameterSpec;
if (target_tp != null) {
+ if (target_tp.TypeArguments != null) {
+ foreach (var targ in target_tp.TypeArguments) {
+ if (!TypeSpecComparer.Override.IsEqual (source_type, targ))
+ continue;
+
+ return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
+ }
+ }
+
if (target_tp.Interfaces != null) {
foreach (TypeSpec iface in target_tp.Interfaces) {
if (!TypeManager.IsGenericParameter (iface))
return EmptyCast.Create (expr, target_type);
}
- bool use_class_cast;
- if (ImplicitBoxingConversionExists (expr_type, target_type, out use_class_cast)) {
- if (use_class_cast)
- return new ClassCast (expr, target_type);
- else
- return new BoxedCast (expr, target_type);
- }
-
- return null;
+ return ImplicitBoxingConversion (expr, expr_type, target_type);
}
//
if (TypeManager.IsValueType (expr_type))
return false;
- if (expr_type.IsClass || expr_type.IsInterface || expr_type == TypeManager.enum_type || expr_type.IsDelegate) {
+ if (expr_type.IsClass || expr_type.IsInterface || expr_type == TypeManager.enum_type || expr_type.IsDelegate || expr_type.Kind == MemberKind.ArrayType) {
// No mcs internal types are convertible
return true; // expr_type.MetaInfo.Module != typeof (Convert).Module;
}
return false;
}
- public static bool ImplicitBoxingConversionExists (TypeSpec expr_type, TypeSpec target_type, out bool use_class_cast)
+ public static Expression ImplicitBoxingConversion (Expression expr, TypeSpec expr_type, TypeSpec target_type)
{
- use_class_cast = false;
-
//
// From any value-type to the type object.
//
// A pointer type cannot be converted to object
//
if (expr_type.IsPointer)
- return false;
+ return null;
- return TypeManager.IsValueType (expr_type);
+ 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.
//
- if (target_type == TypeManager.value_type)
- return TypeManager.IsValueType (expr_type);
+ if (target_type == TypeManager.value_type) {
+ if (!TypeManager.IsValueType (expr_type))
+ return null;
+
+ return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
+ }
if (target_type == TypeManager.enum_type) {
//
// From any enum-type to the type System.Enum.
//
if (TypeManager.IsEnumType (expr_type))
- return true;
+ return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
}
//
//
if (TypeManager.IsNullableType (expr_type)) {
if (!TypeManager.IsReferenceType (target_type))
- return false;
+ return null;
+
+ var res = ImplicitBoxingConversion (expr, Nullable.NullableInfo.GetUnderlyingType (expr_type), target_type);
+
+ // "cast" underlying type to target type to emit correct InvalidCastException when
+ // underlying hierarchy changes without recompilation
+ if (res != null && expr != null)
+ res = new UnboxCast (res, target_type);
- return ImplicitBoxingConversionExists (Nullable.NullableInfo.GetUnderlyingType (expr_type), target_type, out use_class_cast);
+ return res;
}
if (TypeManager.IsSubclassOf (expr_type, target_type)) {
// Don't box same type arguments
//
if (TypeManager.IsGenericParameter (expr_type) && expr_type != target_type)
- return true;
+ return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
- return false;
+ return null;
}
// This code is kind of mirrored inside ImplicitStandardConversionExists
// from any class-type S to any interface-type T.
if (target_type.IsInterface) {
- if (expr_type.ImplementsInterface (target_type))
- return TypeManager.IsGenericParameter (expr_type) ||
- TypeManager.IsValueType (expr_type);
+ if (expr_type.ImplementsInterface (target_type) &&
+ (TypeManager.IsGenericParameter (expr_type) || TypeManager.IsValueType (expr_type))) {
+ return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
+ }
}
- return false;
+ return null;
}
public static Expression ImplicitNulableConversion (ResolveContext ec, Expression expr, TypeSpec target_type)
return ec == null ? EmptyExpression.Null : Nullable.LiftedNull.Create (target_type, expr.Location);
// S -> T?
- TypeSpec t_el = TypeManager.GetTypeArguments (target_type)[0];
+ TypeSpec t_el = Nullable.NullableInfo.GetUnderlyingType (target_type);
// S? -> T?
if (TypeManager.IsNullableType (expr_type))
- expr_type = TypeManager.GetTypeArguments (expr_type)[0];
+ expr_type = Nullable.NullableInfo.GetUnderlyingType (expr_type);
//
// Predefined implicit identity or implicit numeric conversion
// has to exist between underlying type S and underlying type T
//
- // Handles probing
+ // conversion exists only mode
if (ec == null) {
if (expr_type == t_el)
return EmptyExpression.Null;
+ if (expr is Constant)
+ return ((Constant) expr).ConvertImplicitly (ec, t_el);
+
return ImplicitNumericConversion (null, expr_type, t_el);
}
else
unwrap = expr;
- Expression conv = expr_type == t_el ? unwrap : ImplicitNumericConversion (unwrap, expr_type, t_el);
- if (conv == null)
- return null;
+ Expression conv = unwrap;
+ if (expr_type != t_el) {
+ if (conv is Constant)
+ conv = ((Constant)conv).ConvertImplicitly (ec, t_el);
+ else
+ conv = ImplicitNumericConversion (conv, expr_type, t_el);
+ if (conv == null)
+ return null;
+ }
+
if (expr_type != expr.Type)
return new Nullable.Lifted (conv, unwrap, target_type).Resolve (ec);
- // Do constant optimization for S -> T?
- if (unwrap is Constant)
- conv = ((Constant) unwrap).ConvertImplicitly (ec, t_el);
-
return Nullable.Wrap.Create (conv, target_type);
}
if (ImplicitReferenceConversionExists (expr, target_type))
return true;
- bool use_class_cast;
- if (ImplicitBoxingConversionExists (expr_type, target_type, out use_class_cast))
+ if (ImplicitBoxingConversion (null, expr_type, target_type) != null)
return true;
//
if (value >= 0)
return true;
}
-
- if (value == 0 && target_type.IsEnum)
- return true;
}
if (expr is LongConstant && target_type == TypeManager.uint64_type){
return true;
}
+ if (expr is IntegralConstant && TypeManager.IsEnumType (target_type)) {
+ var i = (IntegralConstant) expr;
+ //
+ // LAMESPEC: csc allows any constant like 0 values to be converted, including const float f = 0.0
+ //
+ // An implicit enumeration conversion permits the decimal-integer-literal 0
+ // to be converted to any enum-type and to any nullable-type whose underlying
+ // type is an enum-type
+ //
+ return i.IsZeroInteger;
+ }
+
//
// If `expr_type' implements `target_type' (which is an iface)
// see TryImplicitIntConversion
/// by making use of FindMostEncomp* methods. Applies the correct rules separately
/// for explicit and implicit conversion operators.
/// </summary>
- static public TypeSpec FindMostSpecificSource (IList<MethodSpec> list,
+ static TypeSpec FindMostSpecificSource (IList<MethodSpec> list,
Expression source, bool apply_explicit_conv_rules)
{
var src_types_set = new List<TypeSpec> ();
/// <summary>
/// User-defined Implicit conversions
/// </summary>
- static public Expression ImplicitUserConversion (ResolveContext ec, Expression source,
- TypeSpec target, Location loc)
+ static public Expression ImplicitUserConversion (ResolveContext ec, Expression source, TypeSpec target, Location loc)
{
- return UserDefinedConversion (ec, source, target, loc, false, true);
+ return UserDefinedConversion (ec, source, target, true, loc);
}
/// <summary>
/// User-defined Explicit conversions
/// </summary>
- static Expression ExplicitUserConversion (ResolveContext ec, Expression source,
- TypeSpec target, Location loc)
+ static Expression ExplicitUserConversion (ResolveContext ec, Expression source, TypeSpec target, Location loc)
{
- return UserDefinedConversion (ec, source, target, loc, true, true);
+ return UserDefinedConversion (ec, source, target, false, loc);
}
- static void AddConversionOperators (List<MethodSpec> list,
- Expression source, TypeSpec target_type,
- bool look_for_explicit,
- MethodGroupExpr mg)
+ static void FindApplicableUserDefinedConversionOperators (IList<MemberSpec> operators, Expression source, TypeSpec target, bool implicitOnly, ref List<MethodSpec> candidates)
{
- if (mg == null)
- return;
-
- TypeSpec source_type = source.Type;
- EmptyExpression expr = EmptyExpression.Grab ();
-
//
// LAMESPEC: Undocumented IntPtr/UIntPtr conversions
// IntPtr -> uint uses int
// UIntPtr -> long uses ulong
//
- if (source_type == TypeManager.intptr_type) {
- if (target_type == TypeManager.uint32_type)
- target_type = TypeManager.int32_type;
- } else if (source_type == TypeManager.uintptr_type) {
- if (target_type == TypeManager.int64_type)
- target_type = TypeManager.uint64_type;
+ if (source.Type == TypeManager.intptr_type) {
+ if (target == TypeManager.uint32_type)
+ target = TypeManager.int32_type;
+ } else if (source.Type == TypeManager.uintptr_type) {
+ if (target == TypeManager.int64_type)
+ target = TypeManager.uint64_type;
}
- foreach (MethodSpec m in mg.Methods) {
- AParametersCollection pd = m.Parameters;
- TypeSpec return_type = m.ReturnType;
- TypeSpec arg_type = pd.Types [0];
+ // For a conversion operator to be applicable, it must be possible
+ // to perform a standard conversion from the source type to
+ // the operand type of the operator, and it must be possible
+ // to perform a standard conversion from the result type of
+ // the operator to the target type.
- if (source_type != arg_type) {
- if (!ImplicitStandardConversionExists (source, arg_type)) {
- if (!look_for_explicit)
- continue;
- expr.SetType (arg_type);
- if (!ImplicitStandardConversionExists (expr, source_type))
- continue;
- }
- }
+ Expression texpr = null;
- if (target_type != return_type) {
- expr.SetType (return_type);
- if (!ImplicitStandardConversionExists (expr, target_type)) {
- if (!look_for_explicit)
- continue;
- expr.SetType (target_type);
- if (!ImplicitStandardConversionExists (expr, return_type))
- continue;
- }
- }
-
- // See LAMESPEC: Exclude IntPtr -> int conversion
- if (source_type == TypeManager.uintptr_type && return_type == TypeManager.uint32_type)
+ foreach (MethodSpec op in operators) {
+
+ // Can be null because MemberCache.GetUserOperator does not resize the array
+ if (op == null)
continue;
- list.Add (m);
- }
-
- EmptyExpression.Release (expr);
- }
-
- /// <summary>
- /// Compute the user-defined conversion operator from source_type to target_type.
- /// `look_for_explicit' controls whether we should also include the list of explicit operators
- /// </summary>
- static MethodSpec GetConversionOperator (CompilerContext ctx, TypeSpec container_type, Expression source, TypeSpec target_type, bool look_for_explicit)
- {
- var ops = new List<MethodSpec> (4);
-
- TypeSpec source_type = source.Type;
+ var t = op.Parameters.Types[0];
+ if (source.Type != t && !ImplicitStandardConversionExists (source, t)) {
+ if (implicitOnly)
+ continue;
- if (source_type != TypeManager.decimal_type) {
- AddConversionOperators (ops, source, target_type, look_for_explicit,
- Expression.MethodLookup (ctx, container_type, source_type, MemberKind.Operator, "op_Implicit", 0, Location.Null));
- if (look_for_explicit) {
- AddConversionOperators (ops, source, target_type, look_for_explicit,
- Expression.MethodLookup (ctx,
- container_type, source_type, MemberKind.Operator, "op_Explicit", 0, Location.Null));
+ if (!ImplicitStandardConversionExists (new EmptyExpression (t), source.Type))
+ continue;
}
- }
- if (target_type != TypeManager.decimal_type) {
- AddConversionOperators (ops, source, target_type, look_for_explicit,
- Expression.MethodLookup (ctx, container_type, target_type, MemberKind.Operator, "op_Implicit", 0, Location.Null));
- if (look_for_explicit) {
- AddConversionOperators (ops, source, target_type, look_for_explicit,
- Expression.MethodLookup (ctx,
- container_type, target_type, MemberKind.Operator, "op_Explicit", 0, Location.Null));
- }
- }
+ t = op.ReturnType;
- if (ops.Count == 0)
- return null;
+ // LAMESPEC: Exclude UIntPtr -> int conversion
+ if (t == TypeManager.uint32_type && source.Type == TypeManager.uintptr_type)
+ continue;
- TypeSpec most_specific_source = FindMostSpecificSource (ops, source, look_for_explicit);
- if (most_specific_source == null)
- return null;
+ if (target != t && !ImplicitStandardConversionExists (new EmptyExpression (t), target)) {
+ if (implicitOnly)
+ continue;
- TypeSpec most_specific_target = FindMostSpecificTarget (ops, target_type, look_for_explicit);
- if (most_specific_target == null)
- return null;
+ if (texpr == null)
+ texpr = new EmptyExpression (target);
- MethodSpec method = null;
+ if (!ImplicitStandardConversionExists (texpr, t))
+ continue;
+ }
- foreach (var m in ops) {
- if (m.ReturnType != most_specific_target)
- continue;
- if (m.Parameters.Types [0] != most_specific_source)
- continue;
- // Ambiguous: more than one conversion operator satisfies the signature.
- if (method != null)
- return null;
- method = m;
- }
+ if (candidates == null)
+ candidates = new List<MethodSpec> ();
- return method;
+ candidates.Add (op);
+ }
}
- /// <summary>
- /// User-defined conversions
- /// </summary>
- public static Expression UserDefinedConversion (ResolveContext ec, Expression source,
- TypeSpec target, Location loc,
- bool look_for_explicit, bool return_convert)
+ //
+ // User-defined conversions
+ //
+ static Expression UserDefinedConversion (ResolveContext ec, Expression source, TypeSpec target, bool implicitOnly, Location loc)
{
+ List<MethodSpec> candidates = null;
+
+ //
+ // If S or T are nullable types, S0 and T0 are their underlying types
+ // otherwise S0 and T0 are equal to S and T respectively.
+ //
TypeSpec source_type = source.Type;
- MethodSpec method = null;
- Expression expr = null;
+ TypeSpec target_type = target;
+ Expression unwrap;
- object o;
- DoubleHash hash;
- if (look_for_explicit) {
- hash = explicit_conv;
- } else {
- // Implicit user operators cannot convert to interfaces
- if (target.IsInterface)
+ if (TypeManager.IsNullableType (source_type)) {
+ // No implicit conversion S? -> T for non-reference types
+ if (implicitOnly && !TypeManager.IsReferenceType (target_type) && !TypeManager.IsNullableType (target_type))
return null;
- hash = implicit_conv;
- }
-
- if (!(source is Constant) && hash.Lookup (source_type, target, out o)) {
- method = (MethodSpec) o;
+ unwrap = source = Nullable.Unwrap.Create (source);
+ source_type = source.Type;
} else {
- if (source_type == InternalType.Dynamic)
- return null;
-
- method = GetConversionOperator (ec.Compiler, null, source, target, look_for_explicit);
+ unwrap = null;
}
- if (method != null) {
- TypeSpec most_specific_source = method.Parameters.Types[0];
+ if (TypeManager.IsNullableType (target_type))
+ target_type = Nullable.NullableInfo.GetUnderlyingType (target_type);
- //
- // This will do the conversion to the best match that we
- // found. Now we need to perform an implict standard conversion
- // if the best match was not the type that we were requested
- // by target.
- //
- if (look_for_explicit) {
- ReportPrinter temp = new SessionReportPrinter ();
- ReportPrinter prev = ec.Report.SetPrinter (temp);
+ // Only these containers can contain a user defined implicit or explicit operators
+ const MemberKind user_conversion_kinds = MemberKind.Class | MemberKind.Struct | MemberKind.TypeParameter;
- expr = ExplicitConversionStandard (ec, source, most_specific_source, loc);
+ if ((source_type.Kind & user_conversion_kinds) != 0 && source_type != TypeManager.decimal_type) {
+ bool declared_only = source_type.IsStruct;
- ec.Report.SetPrinter (prev);
- if (temp.ErrorsCount != 0)
- expr = null;
- } else {
- if (ImplicitStandardConversionExists (source, most_specific_source))
- expr = ImplicitConversionStandard (ec, source, most_specific_source, loc);
- else
- expr = null;
+ var operators = MemberCache.GetUserOperator (source_type, Operator.OpType.Implicit, declared_only);
+ if (operators != null) {
+ FindApplicableUserDefinedConversionOperators (operators, source, target_type, implicitOnly, ref candidates);
}
- }
-
- if (expr == null) {
- bool nullable = false;
- if (TypeManager.IsNullableType (source_type)) {
- source = Nullable.Unwrap.Create (source);
- nullable = true;
+ if (!implicitOnly) {
+ operators = MemberCache.GetUserOperator (source_type, Operator.OpType.Explicit, declared_only);
+ if (operators != null) {
+ FindApplicableUserDefinedConversionOperators (operators, source, target_type, false, ref candidates);
+ }
}
+ }
- TypeSpec target_underlying;
- if (TypeManager.IsNullableType (target)) {
- target_underlying = TypeManager.GetTypeArguments (target)[0];
- nullable = true;
- } else {
- // No implicit conversion S? -> T for non-reference type T
- if (!look_for_explicit && !TypeManager.IsReferenceType (target))
- nullable = false;
+ if ((target.Kind & user_conversion_kinds) != 0 && target != TypeManager.decimal_type) {
+ bool declared_only = target.IsStruct || implicitOnly;
- target_underlying = target;
+ var operators = MemberCache.GetUserOperator (target_type, Operator.OpType.Implicit, declared_only);
+ if (operators != null) {
+ FindApplicableUserDefinedConversionOperators (operators, source, target_type, implicitOnly, ref candidates);
}
- if (nullable) {
- expr = UserDefinedConversion (ec, source, target_underlying, loc, look_for_explicit, return_convert);
+ if (!implicitOnly) {
+ operators = MemberCache.GetUserOperator (target_type, Operator.OpType.Explicit, declared_only);
+ if (operators != null) {
+ FindApplicableUserDefinedConversionOperators (operators, source, target_type, false, ref candidates);
+ }
+ }
+ }
- // Do result expression lifting only when it's needed
- if (expr != null && (!look_for_explicit || TypeManager.IsReferenceType (target)))
- expr = new Nullable.Lifted (expr, source, target).Resolve (ec);
+ if (candidates == null)
+ return null;
- return expr;
- }
+ //
+ // Find the most specific conversion operator
+ //
+ MethodSpec most_specific_operator;
+ TypeSpec s_x, t_x;
+ if (candidates.Count == 1) {
+ most_specific_operator = candidates[0];
+ s_x = most_specific_operator.Parameters.Types[0];
+ t_x = most_specific_operator.ReturnType;
} else {
- expr = new UserCast (method, expr, loc).Resolve (ec);
+ s_x = FindMostSpecificSource (candidates, source, !implicitOnly);
+ if (s_x == null)
+ return null;
+
+ t_x = FindMostSpecificTarget (candidates, target, !implicitOnly);
+ if (t_x == null)
+ return null;
- if (return_convert && !TypeManager.IsEqual (expr.Type, target)) {
- if (look_for_explicit) {
- expr = ExplicitConversionStandard (ec, expr, target, loc);
- } else {
- expr = ImplicitConversionStandard (ec, expr, target, loc);
+ most_specific_operator = candidates[0];
+
+ for (int i = 1; i < candidates.Count; ++i) {
+ if (candidates[i].ReturnType == t_x && candidates[i].Parameters.Types[0] == s_x) {
+ most_specific_operator = candidates[i];
+ break;
}
}
}
- if (!(source is Constant))
- hash.Insert (source_type, target, method);
+ //
+ // Convert input type when it's different to best operator argument
+ //
+ if (s_x != source.Type)
+ source = implicitOnly ?
+ ImplicitConversionStandard (ec, source, s_x, loc) :
+ ExplicitConversionStandard (ec, source, s_x, loc);
+
+ source = new UserCast (most_specific_operator, source, loc).Resolve (ec);
- return expr;
+ //
+ // Convert result type when it's different to best operator return type
+ //
+ if (t_x != target_type) {
+ //
+ // User operator is of T?, no need to lift it
+ //
+ if (TypeManager.IsNullableType (t_x) && t_x == target)
+ return source;
+
+ source = implicitOnly ?
+ ImplicitConversionStandard (ec, source, target_type, loc) :
+ ExplicitConversionStandard (ec, source, target_type, loc);
+ }
+
+ //
+ // Source expression is of nullable type, lift the result in case of it's null
+ //
+ if (unwrap != null && (TypeManager.IsReferenceType (target) || target_type != target))
+ source = new Nullable.Lifted (source, unwrap, target).Resolve (ec);
+ else if (target_type != target)
+ source = Nullable.Wrap.Create (source, target);
+
+ return source;
}
/// <summary>
if (e != null)
return e;
- if (expr is IntConstant && TypeManager.IsEnumType (target_type)){
- Constant i = (Constant) expr;
+ if (expr is IntegralConstant && TypeManager.IsEnumType (target_type)){
+ var i = (IntegralConstant) expr;
//
- // LAMESPEC: Conversion from any 0 constant is allowed
+ // LAMESPEC: csc allows any constant like 0 values to be converted, including const float f = 0.0
//
// An implicit enumeration conversion permits the decimal-integer-literal 0
// to be converted to any enum-type and to any nullable-type whose underlying
// type is an enum-type
//
- if (i.IsDefaultValue)
- return new EnumConstant (i, target_type).Resolve (ec);
+ if (i.IsZeroInteger) {
+ // Recreate 0 literal to remove any collected conversions
+ return new EnumConstant (new IntLiteral (0, i.Location), target_type).Resolve (ec);
+ }
}
if (ec.IsUnsafe) {
//
// Explicit type parameter conversion.
//
- if (TypeManager.IsGenericParameter (source_type))
+ if (source_type.Kind == MemberKind.TypeParameter)
return ExplicitTypeParameterConversion (source, source_type, target_type);
bool target_is_value_type = TypeManager.IsStruct (target_type) || TypeManager.IsEnumType (target_type);
// From object to any reference type or value type (unboxing)
//
if (source_type == TypeManager.object_type)
- return source == null ? EmptyExpression.Null :
- target_is_value_type ? (Expression) new UnboxCast (source, target_type) : new ClassCast (source, target_type);
+ return
+ source == null ? EmptyExpression.Null :
+ target_is_value_type ? new UnboxCast (source, target_type) :
+ source is Constant ? (Expression) new EmptyConstantCast ((Constant) source, target_type) :
+ new ClassCast (source, target_type);
//
// From any class S to any class-type T, provided S is a base class of T
//
- if (TypeManager.IsSubclassOf (target_type, source_type))
+ if (source_type.Kind == MemberKind.Class && TypeManager.IsSubclassOf (target_type, source_type))
return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
//
return Nullable.Wrap.Create (e, target_type);
}
} else if (TypeManager.IsNullableType (expr_type)) {
- bool use_class_cast;
- if (ImplicitBoxingConversionExists (Nullable.NullableInfo.GetUnderlyingType (expr_type), target_type, out use_class_cast))
- return new BoxedCast (expr, target_type);
+ e = ImplicitBoxingConversion (expr, Nullable.NullableInfo.GetUnderlyingType (expr_type), target_type);
+ if (e != null)
+ return e;
e = Nullable.Unwrap.Create (expr, false);
e = ExplicitConversionCore (ec, e, target_type, loc);
projects / mono.git / blobdiff