// A container class for all the conversion operations
//
public class Convert {
- static void Error_CannotConvertType (Location loc, Type source, Type target)
+ //
+ // 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 (source) + "' to '" +
static bool TypeParameter_to_Null (Type target_type)
{
- if ((target_type.BaseType == null) ||
- (target_type.BaseType == TypeManager.value_type) ||
- target_type.BaseType.IsValueType)
+ GenericConstraints gc = TypeManager.GetTypeParameterConstraints (target_type);
+ if (gc == null)
return false;
- return true;
+ 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;
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 (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 (TypeManager.IsValueType (expr_type))
return new BoxedCast (expr);
- if (expr is NullLiteral)
+ if (expr_type == TypeManager.null_type)
return new NullCast (expr, target_type);
return null;
// Always ensure that the code here and there is in sync
// from the null type to any reference-type.
- if (expr is NullLiteral){
+ if (expr_type == TypeManager.null_type){
if (target_type.IsPointer)
- return NullPointer.Null;
+ return new EmptyCast (expr, target_type);
if (!target_type.IsValueType)
return new NullCast (expr, target_type);
Type target_element_type = TypeManager.GetElementType (target_type);
if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
- if (ImplicitStandardConversionExists (MyEmptyExpr,
+ if (ImplicitStandardConversionExists (ConstantEC, MyEmptyExpr,
target_element_type))
return new EmptyCast (expr, target_type);
}
return new EmptyCast (expr, target_type);
// from a generic type definition to a generic instance.
- if (TypeManager.IsEqualGenericType (expr_type, target_type))
+ if (TypeManager.IsEqual (expr_type, target_type))
return new EmptyCast (expr, target_type);
- if (expr_type.IsGenericParameter) {
- GenericConstraints gc = TypeManager.GetTypeParameterConstraints (expr_type);
-
- // We're converting from a type parameter which is known to be a reference type.
- if ((gc != null) && gc.IsReferenceType) {
- if (gc.HasClassConstraint && gc.ClassConstraint.IsSubclassOf (target_type))
- return new EmptyCast (expr, target_type);
-
- if (target_type.IsInterface) {
- foreach (Type t in gc.InterfaceConstraints) {
- if (TypeManager.ImplementsInterface (t, 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 || TypeManager.IsValueType (expr_type) ||
expr_type.IsInterface || expr_type == TypeManager.enum_type)
+ if (target_type != TypeManager.anonymous_method_type)
return true;
return false;
// 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;
+ }
+
if (TypeManager.ImplementsInterface (expr_type, target_type))
return true;
}
Type target_element_type = TypeManager.GetElementType (target_type);
if (!expr_element_type.IsValueType && !target_element_type.IsValueType)
- if (ImplicitStandardConversionExists (MyEmptyExpr,
+ if (ImplicitStandardConversionExists (ConstantEC, MyEmptyExpr,
target_element_type))
return true;
}
return true;
// from the null type to any reference-type.
- if (expr is NullLiteral && !target_type.IsValueType && !TypeManager.IsEnumType (target_type))
- return true;
+ 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.IsEqualGenericType (expr_type, target_type))
+ if (TypeManager.IsEqual (expr_type, target_type))
return true;
- if (expr_type.IsGenericParameter) {
- GenericConstraints gc = TypeManager.GetTypeParameterConstraints (expr_type);
-
- // We're converting from a type parameter which is known to be a reference type.
- if ((gc != null) && gc.IsReferenceType) {
- if (gc.HasClassConstraint && gc.ClassConstraint.IsSubclassOf (target_type))
- return true;
-
- if (target_type.IsInterface) {
- foreach (Type t in gc.InterfaceConstraints) {
- if (TypeManager.ImplementsInterface (t, target_type))
- return true;
- }
- }
- }
- }
-
return false;
}
if ((expr is NullLiteral) && target_type.IsGenericParameter)
return TypeParameter_to_Null (target_type);
- if (ImplicitStandardConversionExists (expr, 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;
return true;
}
- if (ImplicitReferenceConversionExists (expr, target_type))
+ if (ImplicitReferenceConversionExists (ec, expr, target_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;
+ int errors = Report.Errors;
+
+ 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>
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;
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);
+ //
+ // 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) && !(expr is NullLiteral))
+ 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;
}
//
// 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)
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>
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){
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)
//
// Unboxing conversion.
//
- if (expr_type == TypeManager.object_type && target_type.IsValueType){
- if (expr is NullLiteral){
- //
- // Skip the ExplicitReferenceConversion because we can not convert
- // from Null to a ValueType, and ExplicitReference wont check against
- // null literal explicitly
- //
- goto skip_explicit;
- }
+ if (expr_type == TypeManager.object_type && target_type.IsValueType)
return new UnboxCast (expr, target_type);
+ //
+ // 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;
}
- ne = ExplicitReferenceConversion (expr, target_type);
- if (ne != null)
- return ne;
-
skip_explicit:
if (ec.InUnsafe){
if (target_type.IsPointer){