// A container class for all the conversion operations
//
public class Convert {
+ //
+ // This is used to prettify the code: a null argument is allowed
+ // for ImplicitStandardConversion as long as it is known that
+ // no anonymous method will play a role.
+ //
+ // FIXME: renamed from `const' to `static' to allow bootstraping from older
+ // versions of the compiler that could not cope with this construct.
+ //
+ public static EmitContext ConstantEC = null;
+
static public void Error_CannotConvertType (Location loc, Type source, Type target)
{
Report.Error (30, loc, "Cannot convert type '" +
TypeManager.CSharpName (target) + "'");
}
+ static Expression TypeParameter_to_Null (Expression expr, Type target_type,
+ Location loc)
+ {
+ if (!TypeParameter_to_Null (target_type)) {
+ Report.Error (403, loc, "Cannot convert null to the type " +
+ "parameter `{0}' becaues it could be a value " +
+ "type. Consider using `default ({0})' instead.",
+ target_type);
+ return null;
+ }
+
+ return new NullCast (expr, target_type);
+ }
+
+ static bool TypeParameter_to_Null (Type target_type)
+ {
+ GenericConstraints gc = TypeManager.GetTypeParameterConstraints (target_type);
+ if (gc == null)
+ return false;
+
+ if (gc.HasReferenceTypeConstraint)
+ return true;
+ if (gc.HasClassConstraint && !TypeManager.IsValueType (gc.ClassConstraint))
+ return true;
+
+ return false;
+ }
+
+ static Type TypeParam_EffectiveBaseType (EmitContext ec, Type t)
+ {
+ GenericConstraints gc = TypeManager.GetTypeParameterConstraints (t);
+ if (gc == null)
+ return TypeManager.object_type;
+
+ return TypeParam_EffectiveBaseType (ec, gc);
+ }
+
+ static Type TypeParam_EffectiveBaseType (EmitContext ec, GenericConstraints gc)
+ {
+ ArrayList list = new ArrayList ();
+ list.Add (gc.EffectiveBaseClass);
+ foreach (Type t in gc.InterfaceConstraints) {
+ if (!t.IsGenericParameter)
+ continue;
+
+ GenericConstraints new_gc = TypeManager.GetTypeParameterConstraints (t);
+ if (new_gc != null)
+ list.Add (TypeParam_EffectiveBaseType (ec, new_gc));
+ }
+ return FindMostEncompassedType (ec, list);
+ }
+
+ static Expression TypeParameterConversion (Expression expr, bool is_reference, Type target_type)
+ {
+ if (is_reference)
+ return new EmptyCast (expr, target_type);
+ else
+ return new BoxedCast (expr, target_type);
+ }
+
+ static Expression ImplicitTypeParameterConversion (EmitContext ec, Expression expr,
+ Type target_type)
+ {
+ Type expr_type = expr.Type;
+
+ GenericConstraints gc = TypeManager.GetTypeParameterConstraints (expr_type);
+
+ if (gc == null) {
+ if (target_type == TypeManager.object_type)
+ return new BoxedCast (expr);
+
+ return null;
+ }
+
+ // We're converting from a type parameter which is known to be a reference type.
+ bool is_reference = gc.IsReferenceType;
+ Type base_type = TypeParam_EffectiveBaseType (ec, gc);
+
+ if (TypeManager.IsSubclassOf (base_type, target_type))
+ return TypeParameterConversion (expr, is_reference, target_type);
+
+ if (target_type.IsInterface) {
+ if (TypeManager.ImplementsInterface (base_type, target_type))
+ return TypeParameterConversion (expr, is_reference, target_type);
+
+ foreach (Type t in gc.InterfaceConstraints) {
+ if (TypeManager.IsSubclassOf (t, target_type))
+ return TypeParameterConversion (expr, is_reference, target_type);
+ }
+ }
+
+ foreach (Type t in gc.InterfaceConstraints) {
+ if (!t.IsGenericParameter)
+ continue;
+ if (TypeManager.IsSubclassOf (t, target_type))
+ return TypeParameterConversion (expr, is_reference, target_type);
+ }
+
+ return null;
+ }
+
static EmptyExpression MyEmptyExpr;
- static public Expression ImplicitReferenceConversion (Expression expr, Type target_type)
+ static public Expression ImplicitReferenceConversion (EmitContext ec, Expression expr, Type target_type)
{
Type expr_type = expr.Type;
expr.Emit (null);
}
+ if (expr_type == TypeManager.void_type)
+ return null;
+
+ if (expr_type.IsGenericParameter)
+ return ImplicitTypeParameterConversion (ec, expr, target_type);
+
//
// notice that it is possible to write "ValueType v = 1", the ValueType here
// is an abstract class, and not really a value type, so we apply the same rules.
if (expr_type.IsPointer)
return null;
- if (expr_type.IsValueType)
+ if (TypeManager.IsValueType (expr_type))
return new BoxedCast (expr);
- if (expr_type.IsClass || expr_type.IsInterface || expr_type == TypeManager.enum_type)
+ if (expr_type.IsClass || expr_type.IsInterface || expr_type == TypeManager.enum_type){
+ if (expr_type == TypeManager.anonymous_method_type)
+ return null;
return new EmptyCast (expr, target_type);
+ }
+
+ return null;
} else if (target_type == TypeManager.value_type) {
- if (expr_type.IsValueType)
+ if (TypeManager.IsValueType (expr_type))
return new BoxedCast (expr);
- if (expr is NullLiteral)
- return new BoxedCast (expr);
- } else if (expr_type.IsSubclassOf (target_type)) {
+ if (expr_type == TypeManager.null_type)
+ return new NullCast (expr, target_type);
+
+ return null;
+ } 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);
- } else {
+ }
- // 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
+ // 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 the null type to any reference-type.
- if (expr is NullLiteral){
- if (target_type.IsPointer)
- return NullPointer.Null;
+ // from the null type to any reference-type.
+ if (expr_type == TypeManager.null_type){
+ if (target_type.IsPointer)
+ return new EmptyCast (expr, target_type);
- if (!target_type.IsValueType)
- return new NullCast (expr, target_type);
- }
+ if (!target_type.IsValueType)
+ return new NullCast (expr, target_type);
+ }
- // 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)
- return new EmptyCast (expr, target_type);
- else if (expr_type.IsValueType)
- return new BoxedCast (expr, target_type);
- }
+ // from any class-type S to any interface-type T.
+ if (target_type.IsInterface) {
+ if (target_type != TypeManager.iconvertible_type &&
+ expr_type.IsValueType && (expr is Constant) &&
+ !(expr is IntLiteral || expr is BoolLiteral ||
+ expr is FloatLiteral || expr is DoubleLiteral ||
+ expr is LongLiteral || expr is CharLiteral ||
+ expr is StringLiteral || expr is DecimalLiteral ||
+ expr is UIntLiteral || expr is ULongLiteral)) {
+ return null;
}
- // from any interface type S to interface-type T.
- if (expr_type.IsInterface && target_type.IsInterface) {
- if (TypeManager.ImplementsInterface (expr_type, target_type))
- return new EmptyCast (expr, target_type);
+ if (TypeManager.ImplementsInterface (expr_type, target_type)){
+ if (expr_type.IsGenericParameter || TypeManager.IsValueType (expr_type))
+ return new BoxedCast (expr, target_type);
else
- return null;
+ return new EmptyCast (expr, target_type);
}
+ }
+
+ // from any interface type S to interface-type T.
+ if (expr_type.IsInterface && target_type.IsInterface) {
+ if (TypeManager.ImplementsInterface (expr_type, target_type))
+ return new EmptyCast (expr, target_type);
+ else
+ return null;
+ }
- // from an array-type S to an array-type of type T
- if (expr_type.IsArray && target_type.IsArray) {
- if (expr_type.GetArrayRank () == target_type.GetArrayRank ()) {
+ // from an array-type S to an array-type of type T
+ if (expr_type.IsArray && target_type.IsArray) {
+ if (expr_type.GetArrayRank () == target_type.GetArrayRank ()) {
- Type expr_element_type = TypeManager.GetElementType (expr_type);
+ Type expr_element_type = TypeManager.GetElementType (expr_type);
- if (MyEmptyExpr == null)
- MyEmptyExpr = new EmptyExpression ();
+ if (MyEmptyExpr == null)
+ MyEmptyExpr = new EmptyExpression ();
- MyEmptyExpr.SetType (expr_element_type);
- Type target_element_type = TypeManager.GetElementType (target_type);
+ MyEmptyExpr.SetType (expr_element_type);
+ Type target_element_type = TypeManager.GetElementType (target_type);
- if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
- if (ImplicitStandardConversionExists (MyEmptyExpr,
+ if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
+ if (ImplicitStandardConversionExists (ConstantEC, MyEmptyExpr,
target_element_type))
- return new EmptyCast (expr, target_type);
- }
+ return new EmptyCast (expr, target_type);
}
+ }
+ // from an array-type to System.Array
+ if (expr_type.IsArray && target_type == TypeManager.array_type)
+ return new EmptyCast (expr, target_type);
- // from an array-type to System.Array
- if (expr_type.IsArray && target_type == TypeManager.array_type)
- return new EmptyCast (expr, target_type);
-
- // from any delegate type to System.Delegate
- if ((expr_type == TypeManager.delegate_type ||
- expr_type.IsSubclassOf (TypeManager.delegate_type)) &&
- target_type == TypeManager.delegate_type)
- return new EmptyCast (expr, target_type);
+ // from any delegate type to System.Delegate
+ if ((expr_type == 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))
- if (target_type == TypeManager.icloneable_type)
- return new EmptyCast (expr, target_type);
-
- return null;
+ // from any array-type or delegate type into System.ICloneable.
+ if (expr_type.IsArray ||
+ expr_type == 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 (TypeManager.IsEqual (expr_type, target_type))
+ return new EmptyCast (expr, target_type);
- }
-
return null;
}
// Tests whether an implicit reference conversion exists between expr_type
// and target_type
//
- public static bool ImplicitReferenceConversionExists (Expression expr, Type target_type)
+ public static bool ImplicitReferenceConversionExists (EmitContext ec, Expression expr, Type target_type)
{
Type expr_type = expr.Type;
+ if (expr_type.IsGenericParameter)
+ return ImplicitTypeParameterConversion (ec, expr, target_type) != null;
+
//
// This is the boxed case.
//
if (target_type == TypeManager.object_type) {
- if (expr_type.IsClass || expr_type.IsValueType ||
+ if (expr_type.IsClass || TypeManager.IsValueType (expr_type) ||
expr_type.IsInterface || expr_type == TypeManager.enum_type)
+ if (target_type != TypeManager.anonymous_method_type)
return true;
- } else if (expr_type.IsSubclassOf (target_type)) {
+
+ return false;
+ } else if (TypeManager.IsSubclassOf (expr_type, target_type))
return true;
- } else {
- // Please remember that all code below actually comes
- // from ImplicitReferenceConversion so make sure code remains in sync
+
+ // Please remember that all code below actually comes
+ // from ImplicitReferenceConversion so make sure code remains in sync
- // from any class-type S to any interface-type T.
- if (target_type.IsInterface) {
- if (TypeManager.ImplementsInterface (expr_type, target_type))
- return true;
+ // from any class-type S to any interface-type T.
+ if (target_type.IsInterface) {
+ if (target_type != TypeManager.iconvertible_type &&
+ expr_type.IsValueType && (expr is Constant) &&
+ !(expr is IntLiteral || expr is BoolLiteral ||
+ expr is FloatLiteral || expr is DoubleLiteral ||
+ expr is LongLiteral || expr is CharLiteral ||
+ expr is StringLiteral || expr is DecimalLiteral ||
+ expr is UIntLiteral || expr is ULongLiteral)) {
+ return false;
}
- // from any interface type S to interface-type T.
- if (expr_type.IsInterface && target_type.IsInterface)
- if (TypeManager.ImplementsInterface (expr_type, target_type))
- return true;
+ if (TypeManager.ImplementsInterface (expr_type, target_type))
+ return true;
+ }
+
+ // from any interface type S to interface-type T.
+ if (expr_type.IsInterface && target_type.IsInterface)
+ if (TypeManager.ImplementsInterface (expr_type, target_type))
+ return true;
- // from an array-type S to an array-type of type T
- if (expr_type.IsArray && target_type.IsArray) {
- if (expr_type.GetArrayRank () == target_type.GetArrayRank ()) {
+ // from an array-type S to an array-type of type T
+ if (expr_type.IsArray && target_type.IsArray) {
+ if (expr_type.GetArrayRank () == target_type.GetArrayRank ()) {
- Type expr_element_type = expr_type.GetElementType ();
+ Type expr_element_type = expr_type.GetElementType ();
- if (MyEmptyExpr == null)
- MyEmptyExpr = new EmptyExpression ();
+ if (MyEmptyExpr == null)
+ MyEmptyExpr = new EmptyExpression ();
- MyEmptyExpr.SetType (expr_element_type);
- Type target_element_type = TypeManager.GetElementType (target_type);
+ MyEmptyExpr.SetType (expr_element_type);
+ Type target_element_type = TypeManager.GetElementType (target_type);
- if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
- if (ImplicitStandardConversionExists (MyEmptyExpr,
+ if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
+ if (ImplicitStandardConversionExists (ConstantEC, MyEmptyExpr,
target_element_type))
- return true;
- }
+ return true;
}
+ }
- // from an array-type to System.Array
- if (expr_type.IsArray && (target_type == TypeManager.array_type))
- return true;
+ // from an array-type to System.Array
+ if (expr_type.IsArray && (target_type == TypeManager.array_type))
+ return true;
- // from any delegate type to System.Delegate
- if ((expr_type == TypeManager.delegate_type ||
- expr_type.IsSubclassOf (TypeManager.delegate_type)) &&
- target_type == TypeManager.delegate_type)
- if (target_type.IsAssignableFrom (expr_type))
- return true;
+ // from any delegate type to System.Delegate
+ if ((expr_type == TypeManager.delegate_type || TypeManager.IsDelegateType (expr_type)) &&
+ target_type == TypeManager.delegate_type)
+ if (target_type.IsAssignableFrom (expr_type))
+ return true;
- // 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))
- if (target_type == TypeManager.icloneable_type)
- return true;
-
- // from the null type to any reference-type.
- if (expr is NullLiteral && !target_type.IsValueType &&
- !TypeManager.IsEnumType (target_type))
+ // from any array-type or delegate type into System.ICloneable.
+ if (expr_type.IsArray ||
+ expr_type == TypeManager.delegate_type || TypeManager.IsDelegateType (expr_type))
+ if (target_type == TypeManager.icloneable_type)
return true;
+ // from the null type to any reference-type.
+ if (expr_type == TypeManager.null_type){
+ if (target_type.IsPointer)
+ return true;
+
+ if (!target_type.IsValueType)
+ return true;
}
+
+ // from a generic type definition to a generic instance.
+ if (TypeManager.IsEqual (expr_type, target_type))
+ return true;
+
return false;
}
Type target_type, Location loc)
{
Type expr_type = expr.Type;
-
+
//
// Attempt to do the implicit constant expression conversions
if (expr is Constant){
-
if (expr is IntConstant){
Expression e;
// we just inline it
//
long v = ((LongConstant) expr).Value;
- if (v > 0)
+ if (v >= 0)
return new ULongConstant ((ulong) v);
}
}
/// </summary>
public static bool ImplicitConversionExists (EmitContext ec, Expression expr, Type target_type)
{
- if (ImplicitStandardConversionExists (expr, target_type))
+ if ((expr is NullLiteral) && target_type.IsGenericParameter)
+ return TypeParameter_to_Null (target_type);
+
+ if (ImplicitStandardConversionExists (ec, expr, target_type))
return true;
Expression dummy = ImplicitUserConversion (ec, expr, target_type, Location.Null);
/// <summary>
/// Determines if a standard implicit conversion exists from
/// expr_type to target_type
+ ///
+ /// ec should point to a real EmitContext if expr.Type is TypeManager.anonymous_method_type.
/// </summary>
- public static bool ImplicitStandardConversionExists (Expression expr, Type target_type)
+ public static bool ImplicitStandardConversionExists (EmitContext ec, Expression expr, Type target_type)
{
Type expr_type = expr.Type;
//Console.WriteLine ("Expr is {0}", expr);
//Console.WriteLine ("{0} -> {1} ?", expr_type, target_type);
- if (expr_type == target_type)
+ if (expr_type.Equals (target_type))
return true;
+
// First numeric conversions
if (expr_type == TypeManager.sbyte_type){
return true;
}
- if (ImplicitReferenceConversionExists (expr, target_type))
- return true;
+ if (expr.eclass == ExprClass.MethodGroup){
+ if (TypeManager.IsDelegateType (target_type) && RootContext.Version != LanguageVersion.ISO_1){
+ MethodGroupExpr mg = expr as MethodGroupExpr;
+ if (mg != null){
+ //
+ // This should not happen frequently, so we can create an object
+ // to test compatibility
+ //
+ Expression c = ImplicitDelegateCreation.Create (ec, mg, target_type, Location.Null);
+ return c != null;
+ }
+ }
+ }
+ if (ImplicitReferenceConversionExists (ec, expr, target_type))
+ return true;
+
+ //
+ // Implicit Constant Expression Conversions
+ //
if (expr is IntConstant){
int value = ((IntConstant) expr).Value;
return true;
}
+ //
+ // If `expr_type' implements `target_type' (which is an iface)
+ // see TryImplicitIntConversion
+ //
+ if (target_type.IsInterface && target_type.IsAssignableFrom (expr_type))
+ return true;
+
if (target_type == TypeManager.void_ptr_type && expr_type.IsPointer)
return true;
+ if (expr_type == TypeManager.anonymous_method_type){
+ if (!TypeManager.IsDelegateType (target_type))
+ return false;
+
+ AnonymousMethod am = (AnonymousMethod) expr;
+
+ Expression conv = am.Compatible (ec, target_type, true);
+ if (conv != null)
+ return true;
+ }
+
return false;
}
/// Finds "most encompassed type" according to the spec (13.4.2)
/// amongst the methods in the MethodGroupExpr
/// </summary>
- static Type FindMostEncompassedType (ArrayList types)
+ static Type FindMostEncompassedType (EmitContext ec, ArrayList types)
{
Type best = null;
continue;
}
- if (ImplicitStandardConversionExists (priv_fmet_param, best))
+ if (ImplicitStandardConversionExists (ec, priv_fmet_param, best))
best = t;
}
/// Finds "most encompassing type" according to the spec (13.4.2)
/// amongst the types in the given set
/// </summary>
- static Type FindMostEncompassingType (ArrayList types)
+ static Type FindMostEncompassingType (EmitContext ec, ArrayList types)
{
Type best = null;
continue;
}
- if (ImplicitStandardConversionExists (priv_fmee_ret, t))
+ if (ImplicitStandardConversionExists (ec, priv_fmee_ret, t))
best = t;
}
/// by making use of FindMostEncomp* methods. Applies the correct rules separately
/// for explicit and implicit conversion operators.
/// </summary>
- static public Type FindMostSpecificSource (MethodGroupExpr me, Expression source,
- bool apply_explicit_conv_rules,
+ static public Type FindMostSpecificSource (EmitContext ec, MethodGroupExpr me,
+ Expression source, bool apply_explicit_conv_rules,
Location loc)
{
ArrayList src_types_set = new ArrayList ();
// or encompassed by S to a type encompassing or encompassed by T
//
priv_fms_expr.SetType (param_type);
- if (ImplicitStandardConversionExists (priv_fms_expr, source_type))
+ if (ImplicitStandardConversionExists (ec, priv_fms_expr, source_type))
src_types_set.Add (param_type);
else {
- if (ImplicitStandardConversionExists (source, param_type))
+ if (ImplicitStandardConversionExists (ec, source, param_type))
src_types_set.Add (param_type);
}
} else {
//
// Only if S is encompassed by param_type
//
- if (ImplicitStandardConversionExists (source, param_type))
+ if (ImplicitStandardConversionExists (ec, source, param_type))
src_types_set.Add (param_type);
}
}
ArrayList candidate_set = new ArrayList ();
foreach (Type param_type in src_types_set){
- if (ImplicitStandardConversionExists (source, param_type))
+ if (ImplicitStandardConversionExists (ec, source, param_type))
candidate_set.Add (param_type);
}
if (candidate_set.Count != 0)
- return FindMostEncompassedType (candidate_set);
+ return FindMostEncompassedType (ec, candidate_set);
}
//
// Final case
//
if (apply_explicit_conv_rules)
- return FindMostEncompassingType (src_types_set);
+ return FindMostEncompassingType (ec, src_types_set);
else
- return FindMostEncompassedType (src_types_set);
+ return FindMostEncompassedType (ec, src_types_set);
}
//
/// <summary>
/// Finds the most specific target Tx according to section 13.4.4
/// </summary>
- static public Type FindMostSpecificTarget (MethodGroupExpr me, Type target,
- bool apply_explicit_conv_rules,
+ static public Type FindMostSpecificTarget (EmitContext ec, MethodGroupExpr me,
+ Type target, bool apply_explicit_conv_rules,
Location loc)
{
ArrayList tgt_types_set = new ArrayList ();
// or encompassed by S to a type encompassing or encompassed by T
//
priv_fms_expr.SetType (ret_type);
- if (ImplicitStandardConversionExists (priv_fms_expr, target))
+ if (ImplicitStandardConversionExists (ec, priv_fms_expr, target))
tgt_types_set.Add (ret_type);
else {
priv_fms_expr.SetType (target);
- if (ImplicitStandardConversionExists (priv_fms_expr, ret_type))
+ if (ImplicitStandardConversionExists (ec, priv_fms_expr, ret_type))
tgt_types_set.Add (ret_type);
}
} else {
// Only if T is encompassed by param_type
//
priv_fms_expr.SetType (ret_type);
- if (ImplicitStandardConversionExists (priv_fms_expr, target))
+ if (ImplicitStandardConversionExists (ec, priv_fms_expr, target))
tgt_types_set.Add (ret_type);
}
}
foreach (Type ret_type in tgt_types_set){
priv_fmt_expr.SetType (ret_type);
- if (ImplicitStandardConversionExists (priv_fmt_expr, target))
+ if (ImplicitStandardConversionExists (ec, priv_fmt_expr, target))
candidate_set.Add (ret_type);
}
if (candidate_set.Count != 0)
- return FindMostEncompassingType (candidate_set);
+ return FindMostEncompassingType (ec, candidate_set);
}
//
// Okay, final case !
//
if (apply_explicit_conv_rules)
- return FindMostEncompassedType (tgt_types_set);
+ return FindMostEncompassedType (ec, tgt_types_set);
else
- return FindMostEncompassingType (tgt_types_set);
+ return FindMostEncompassingType (ec, tgt_types_set);
}
/// <summary>
return UserDefinedConversion (ec, source, target, loc, true);
}
+ static DoubleHash explicit_conv = new DoubleHash (100);
+ static DoubleHash implicit_conv = new DoubleHash (100);
/// <summary>
/// Computes the MethodGroup for the user-defined conversion
/// operators from source_type to target_type. `look_for_explicit'
op_name = "op_Implicit";
MethodGroupExpr union3;
+ object r;
+ if ((look_for_explicit ? explicit_conv : implicit_conv).Lookup (source_type, target_type, out r))
+ return (MethodGroupExpr) r;
mg1 = Expression.MethodLookup (ec, source_type, op_name, loc);
if (source_type.BaseType != null)
union4 = Invocation.MakeUnionSet (union5, union6, loc);
}
- return Invocation.MakeUnionSet (union3, union4, loc);
+ MethodGroupExpr ret = Invocation.MakeUnionSet (union3, union4, loc);
+ (look_for_explicit ? explicit_conv : implicit_conv).Insert (source_type, target_type, ret);
+ return ret;
}
/// <summary>
Type most_specific_source, most_specific_target;
- most_specific_source = FindMostSpecificSource (union, source, look_for_explicit, loc);
+ most_specific_source = FindMostSpecificSource (ec, union, source, look_for_explicit, loc);
if (most_specific_source == null)
return null;
- most_specific_target = FindMostSpecificTarget (union, target, look_for_explicit, loc);
+ most_specific_target = FindMostSpecificTarget (ec, union, target, look_for_explicit, loc);
if (most_specific_target == null)
return null;
/// in a context that expects a `target_type'.
/// </summary>
static public Expression ImplicitConversion (EmitContext ec, Expression expr,
- Type target_type, Location loc)
+ Type target_type, Location loc)
{
- Type expr_type = expr.Type;
Expression e;
if (target_type == null)
Type expr_type = expr.Type;
Expression e;
- if (expr_type == target_type && !(expr is NullLiteral))
+ if ((expr is NullLiteral) && target_type.IsGenericParameter)
+ return TypeParameter_to_Null (expr, target_type, loc);
+
+ if (expr.eclass == ExprClass.MethodGroup){
+ if (!TypeManager.IsDelegateType (target_type)){
+ return null;
+ }
+
+ //
+ // Only allow anonymous method conversions on post ISO_1
+ //
+ if (RootContext.Version != LanguageVersion.ISO_1){
+ MethodGroupExpr mg = expr as MethodGroupExpr;
+ if (mg != null)
+ return ImplicitDelegateCreation.Create (ec, mg, target_type, loc);
+ }
+ }
+
+ if (expr_type.Equals (target_type) && !TypeManager.IsNullType (expr_type))
return expr;
e = ImplicitNumericConversion (ec, expr, target_type, loc);
if (e != null)
return e;
- e = ImplicitReferenceConversion (expr, target_type);
+ e = ImplicitReferenceConversion (ec, expr, target_type);
if (e != null)
return e;
}
if (target_type.IsPointer) {
- if (expr is NullLiteral)
+ if (expr_type == TypeManager.null_type)
return new EmptyCast (expr, target_type);
if (expr_type == TypeManager.void_ptr_type)
}
}
+ if (expr_type == TypeManager.anonymous_method_type){
+ if (!TypeManager.IsDelegateType (target_type)){
+ Report.Error (1660, loc,
+ "Cannot convert anonymous method to `{0}', since it is not a delegate",
+ TypeManager.CSharpName (target_type));
+ return null;
+ }
+
+ AnonymousMethod am = (AnonymousMethod) expr;
+ int errors = Report.Errors;
+
+ Expression conv = am.Compatible (ec, target_type, false);
+ if (conv != null)
+ return conv;
+
+ //
+ // We return something instead of null, to avoid
+ // the duplicate error, since am.Compatible would have
+ // reported that already
+ //
+ if (errors != Report.Errors)
+ return new EmptyCast (expr, target_type);
+ }
+
return null;
}
/// <summary>
- /// Attemps to perform an implict constant conversion of the IntConstant
+ /// Attempts to perform an implicit constant conversion of the IntConstant
/// into a different data type using casts (See Implicit Constant
/// Expression Conversions)
/// </summary>
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)
//
// Possibly, we need to create a different 0 literal before passing
// to EnumConstant
- //n
+ //
if (underlying == TypeManager.int64_type)
e = new LongLiteral (0);
else if (underlying == TypeManager.uint64_type)
return new EnumConstant (e, target_type);
}
+
+ //
+ // If `target_type' is an interface and the type of `ic' implements the interface
+ // e.g. target_type is IComparable, IConvertible, IFormattable
+ //
+ if (target_type.IsInterface && target_type.IsAssignableFrom (ic.Type))
+ return new BoxedCast (ic);
+
return null;
}
static public void Error_CannotImplicitConversion (Location loc, Type source, Type target)
{
- string msg = "Cannot convert implicitly from `"+
- TypeManager.CSharpName (source) + "' to `" +
- TypeManager.CSharpName (target) + "'";
-
- Report.Error (29, loc, msg);
+ if (source.Name == target.Name){
+ Report.ExtraInformation (loc,
+ String.Format (
+ "The type {0} has two conflicting definitons, one comes from {0} and the other from {1}",
+ source.Assembly.FullName, target.Assembly.FullName));
+
+ }
+ Report.Error (29, loc, "Cannot convert implicitly from {0} to `{1}'",
+ source == TypeManager.anonymous_method_type ?
+ "anonymous method" : "`" + TypeManager.CSharpName (source) + "'",
+ TypeManager.CSharpName (target));
}
/// <summary>
- /// Attemptes to implicityly convert `target' into `type', using
+ /// Attempts to implicitly convert `source' into `target_type', using
/// ImplicitConversion. If there is no implicit conversion, then
/// an error is signaled
/// </summary>
Type target_type, Location loc)
{
Expression e;
-
+
+ int errors = Report.Errors;
e = ImplicitConversion (ec, source, target_type, loc);
+ if (Report.Errors > errors)
+ return null;
if (e != null)
return e;
- if (source is DoubleLiteral && target_type == TypeManager.float_type){
- Report.Error (664, loc,
- "Double literal cannot be implicitly converted to " +
- "float type, use F suffix to create a float literal");
+ if (source is DoubleLiteral) {
+ if (target_type == TypeManager.float_type) {
+ Error_664 (loc, "float", "f");
+ return null;
+ }
+ if (target_type == TypeManager.decimal_type) {
+ Error_664 (loc, "decimal", "m");
+ return null;
+ }
}
+ 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;
}
+ static void Error_664 (Location loc, string type, string suffix) {
+ Report.Error (664, loc,
+ "Literal of type double cannot be implicitly converted to type '{0}'. Add suffix '{1}' to create a literal of this type",
+ type, suffix);
+ }
+
/// <summary>
/// Performs the explicit numeric conversions
/// </summary>
if (TypeManager.IsEnumType (real_target_type))
real_target_type = TypeManager.EnumToUnderlying (real_target_type);
- if (ImplicitStandardConversionExists (expr, real_target_type)){
+ if (ImplicitStandardConversionExists (ec, expr, real_target_type)){
Expression ce = ImplicitConversionStandard (ec, expr, real_target_type, loc);
if (real_target_type != target_type)
/// </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
//
//
// 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;
}
// 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;
//
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);
//
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.
// sealed, or provided T implements S.
//
if (source_type.IsInterface) {
- if (!target_type.IsSealed || TypeManager.ImplementsInterface (target_type, source_type))
- return new ClassCast (source, target_type);
- else
- return null;
+ if (!target_type.IsSealed || TypeManager.ImplementsInterface (target_type, source_type)) {
+ if (target_type.IsClass)
+ return new ClassCast (source, target_type);
+ else
+ return new UnboxCast (source, target_type);
+ }
+
+ return null;
}
// From an array type S with an element type Se to an array type T with an
// 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);
//
/// type is expr.Type to `target_type'.
/// </summary>
static public Expression ExplicitConversion (EmitContext ec, Expression expr,
- Type target_type, Location loc)
+ Type target_type, Location loc)
{
Type expr_type = expr.Type;
Type original_expr_type = expr_type;
expr_type = expr.Type;
}
+ int errors = Report.Errors;
Expression ne = ImplicitConversionStandard (ec, expr, target_type, loc);
+ if (Report.Errors > errors)
+ return null;
if (ne != null)
return ne;
//
// Unboxing conversion.
//
- if (expr_type == TypeManager.object_type && target_type.IsValueType){
- if (expr is NullLiteral){
- Report.Error (37, "Cannot convert null to value type `" +
- TypeManager.CSharpName (expr_type) + "'");
- return null;
- }
+ if (expr_type == TypeManager.object_type && target_type.IsValueType)
return new UnboxCast (expr, target_type);
- }
-
- ne = ExplicitReferenceConversion (expr, target_type);
- if (ne != null)
- return ne;
+ //
+ // Skip the ExplicitReferenceConversion because we can not convert
+ // from Null to a ValueType, and ExplicitReference wont check against
+ // null literal explicitly
+ //
+ if (expr_type != TypeManager.null_type){
+ ne = ExplicitReferenceConversion (expr, target_type);
+ if (ne != null)
+ return ne;
+ }
+ skip_explicit:
if (ec.InUnsafe){
if (target_type.IsPointer){
if (expr_type.IsPointer)
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;
}
/// Same as ExplicitConversion, only it doesn't include user defined conversions
/// </summary>
static public Expression ExplicitConversionStandard (EmitContext ec, Expression expr,
- Type target_type, Location l)
+ Type target_type, Location l)
{
+ int errors = Report.Errors;
Expression ne = ImplicitConversionStandard (ec, expr, target_type, l);
+ if (Report.Errors > errors)
+ return null;
if (ne != null)
return ne;
projects / mono.git / blobdiff