return;
}
+ bool dereference = IsRef && !(source is ReferenceExpression);
New n_source = source as New;
if (n_source != null && n_source.CanEmitOptimizedLocalTarget (ec)) {
if (!n_source.Emit (ec, this)) {
if (leave_copy) {
EmitLoad (ec);
- if (IsRef)
+ if (dereference)
ec.EmitLoadFromPtr (type);
}
return;
}
} else {
- if (IsRef)
+ if (dereference)
EmitLoad (ec);
source.Emit (ec);
if (leave_copy) {
ec.Emit (OpCodes.Dup);
- if (IsRef) {
+ if (dereference) {
temp = new LocalTemporary (Type);
temp.Store (ec);
}
}
- if (IsRef)
+ if (dereference)
ec.EmitStoreFromPtr (type);
else
Variable.EmitAssign (ec);
}
public override bool IsRef {
- get { return false; }
+ get { return local_info.IsByRef; }
}
public override string Name {
AnonymousMethodExpression.Error_AddressOfCapturedVar (ec, this, loc);
} else if (local_info.IsFixed) {
ec.Report.Error (1764, loc,
- "Cannot use fixed local `{0}' inside an anonymous method, lambda expression or query expression",
+ "Cannot use fixed variable `{0}' inside an anonymous method, lambda expression or query expression",
+ GetSignatureForError ());
+ } else if (local_info.IsByRef) {
+ ec.Report.Error (8175, loc,
+ "Cannot use by-reference variable `{0}' inside an anonymous method, lambda expression, or query expression",
GetSignatureForError ());
}
protected override Expression DoResolve (ResolveContext rc)
{
ResolveConditionalAccessReceiver (rc);
- return DoResolveInvocation (rc);
+ return DoResolveInvocation (rc, null);
}
public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
return res.Resolve (rc);
}
+ if (right_side != null) {
+ if (eclass != ExprClass.Unresolved)
+ return this;
+
+ var res = DoResolveInvocation (rc, right_side);
+ if (res == null)
+ return null;
+
+ return res;
+ }
+
return base.DoResolveLValue (rc, right_side);
}
- Expression DoResolveInvocation (ResolveContext ec)
+ Expression DoResolveInvocation (ResolveContext ec, Expression rhs)
{
Expression member_expr;
var atn = expr as ATypeNameExpression;
IsSpecialMethodInvocation (ec, method, loc);
eclass = ExprClass.Value;
+
+ if (type.Kind == MemberKind.ByRef) {
+ if (rhs == null && arguments?.ContainsEmitWithAwait () == true) {
+ ec.Report.Error (8178, loc, "`await' cannot be used in an expression containing a call to `{0}' because it returns by reference",
+ GetSignatureForError ());
+ }
+
+ if (rhs != EmptyExpression.OutAccess)
+ return ByRefDereference.Create (this).Resolve (ec);
+ }
+
return this;
}
}
}
+ class ReferenceTypeExpr : TypeExpr
+ {
+ FullNamedExpression element;
+
+ public ReferenceTypeExpr (FullNamedExpression element, Location loc)
+ {
+ this.element = element;
+ this.loc = loc;
+ }
+
+ public override TypeSpec ResolveAsType (IMemberContext mc, bool allowUnboundTypeArguments = false)
+ {
+ type = element.ResolveAsType (mc);
+ if (type == null)
+ return null;
+
+ eclass = ExprClass.Type;
+ type = ReferenceContainer.MakeType (mc.Module, type);
+
+ return type;
+ }
+
+ public override string GetSignatureForError ()
+ {
+ return "ref " + element.GetSignatureForError ();
+ }
+
+ public override object Accept (StructuralVisitor visitor)
+ {
+ return visitor.Visit (this);
+ }
+ }
+
class FixedBufferPtr : Expression
{
readonly Expression array;
return Reachability.CreateUnreachable ();
}
}
+
+ class ReferenceExpression : CompositeExpression
+ {
+ public ReferenceExpression (Expression expr, Location loc)
+ : base (expr)
+ {
+ this.loc = loc;
+ }
+
+ static bool CanBeByRef (Expression expr)
+ {
+ if (expr is IAssignMethod)
+ return true;
+
+ var invocation = expr as Invocation;
+ if (invocation?.Type.Kind == MemberKind.ByRef)
+ return true;
+
+ return false;
+ }
+
+ public override Expression CreateExpressionTree (ResolveContext rc)
+ {
+ throw new NotSupportedException ("ET");
+ }
+
+ protected override Expression DoResolve (ResolveContext rc)
+ {
+ var res = expr.DoResolveLValue (rc, EmptyExpression.OutAccess);
+ if (res == null || !CanBeByRef (res)) {
+ if (res?.Type != InternalType.ErrorType)
+ rc.Report.Error (8156, expr.Location, "An expression cannot be used in this context because it may not be returned by reference");
+ return ErrorExpression.Instance;
+ }
+
+ type = res.Type;
+ var type_container = type as ReferenceContainer;
+ if (type_container != null)
+ type = type_container.Element;
+
+ expr = res;
+ eclass = ExprClass.Value;
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ var ml = expr as IMemoryLocation;
+ if (ml != null)
+ ml.AddressOf (ec, AddressOp.LoadStore);
+ else
+ expr.Emit (ec);
+ }
+
+ public override void Error_ValueCannotBeConverted (ResolveContext rc, TypeSpec target, bool expl)
+ {
+ rc.Report.Error (8173, loc, "The expression must be of type `{0}' because it is being assigned by reference", target.GetSignatureForError ());
+ }
+ }
+
+ class ByRefDereference : CompositeExpression, IMemoryLocation, IAssignMethod
+ {
+ bool prepared;
+ LocalTemporary temporary;
+
+ private ByRefDereference (Expression expr)
+ : base (expr)
+ {
+ }
+
+ public static Expression Create (Expression expr)
+ {
+ var rc = expr.Type as ReferenceContainer;
+ if (rc == null)
+ return expr;
+
+ return new ByRefDereference (expr) {
+ type = rc.Element
+ };
+ }
+
+ public void AddressOf (EmitContext ec, AddressOp mode)
+ {
+ expr.Emit (ec);
+ }
+
+ public void Emit (EmitContext ec, bool leave_copy)
+ {
+ Emit (ec);
+ if (leave_copy) {
+ ec.Emit (OpCodes.Dup);
+ temporary = new LocalTemporary (type);
+ temporary.Store (ec);
+ }
+ }
+
+ public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool isCompound)
+ {
+ prepared = isCompound;
+
+ expr.Emit (ec);
+
+ if (isCompound)
+ ec.Emit (OpCodes.Dup);
+
+ source.Emit (ec);
+ if (leave_copy) {
+ throw new NotImplementedException ("leave_copy");
+ }
+
+ ec.EmitStoreFromPtr (type);
+
+ if (temporary != null) {
+ temporary.Emit (ec);
+ temporary.Release (ec);
+ }
+ }
+
+ protected override Expression DoResolve (ResolveContext rc)
+ {
+ eclass = ExprClass.Variable;
+ return this;
+ }
+
+ public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
+ {
+ return DoResolve (rc);
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ if (!prepared)
+ base.Emit(ec);
+
+ ec.EmitLoadFromPtr (type);
+ }
+
+ public override object Accept (StructuralVisitor visitor)
+ {
+ return visitor.Visit (this);
+ }
+ }
}
projects / mono.git / blobdiff