private TEmitResult EmitCore(IXamlAstNode value, TBackendEmitter codeGen, IXamlType expectedType)
{
TEmitResult res = EmitNode(value, codeGen);
IXamlType returnedType = res.ReturnType;
if (returnedType != null || expectedType != null)
{
if (returnedType != null && expectedType == null)
{
throw new XamlLoadException(
$"Emit of node {value} resulted in {returnedType.GetFqn()} while caller expected void", value);
}
if (expectedType != null && returnedType == null)
{
throw new XamlLoadException(
$"Emit of node {value} resulted in void while caller expected {expectedType.GetFqn()}", value);
}
if (!returnedType.Equals(expectedType))
{
EmitConvert(value, codeGen, expectedType, returnedType);
}
}
return(res);
}
public XamlILNodeEmitResult Emit(XamlEmitContext <IXamlILEmitter, XamlILNodeEmitResult> context, IXamlILEmitter codeGen)
{
var type = Value.GetClrType();
var method = _systemType.Methods.FirstOrDefault(m =>
m.Name == "GetTypeFromHandle" && m.Parameters.Count == 1 &&
m.Parameters[0].Name == "RuntimeTypeHandle");
if (method == null)
{
throw new XamlTypeSystemException(
$"Unable to find GetTypeFromHandle(RuntimeTypeHandle) on {_systemType.GetFqn()}");
}
codeGen
.Emit(OpCodes.Ldtoken, type)
.EmitCall(method);
return(XamlILNodeEmitResult.Type(0, _systemType));
}
public override string ToString() => Type.GetFqn();
public static IXamlConstructor GetConstructor(this IXamlType type, List <IXamlType> args = null)
{
var found = FindConstructor(type, args);
if (found == null)
{
if (args != null && args.Count > 0)
{
var argsString = string.Join(", ", args.Select(a => a.GetFullName()));
throw new XamlTypeSystemException($"Constructor with arguments {argsString} is not found on type {type.GetFqn()}");
}
throw new XamlTypeSystemException($"Constructor with no arguments is not found on type {type.GetFqn()}");
}
return(found);
}
public static IXamlMethod GetMethod(this IXamlType type, FindMethodMethodSignature signature)
{
var found = FindMethod(type, signature);
if (found == null)
{
throw new XamlTypeSystemException($"Method with signature {signature} is not found on type {type.GetFqn()}");
}
return(found);
}
public static void EmitConvert(XamlEmitContextWithLocals <IXamlILEmitter, XamlILNodeEmitResult> context, IXamlLineInfo node, IXamlType what,
IXamlType to, Func <bool, IXamlILEmitter> ld)
{
if (what.Equals(to))
{
ld(false);
}
else if (what == XamlPseudoType.Null)
{
if (to.IsValueType)
{
if (to.GenericTypeDefinition?.Equals(context.Configuration.WellKnownTypes.NullableT) == true)
{
using (var loc = context.GetLocalOfType(to))
ld(false)
.Pop()
.Ldloca(loc.Local)
.Emit(OpCodes.Initobj, to)
.Ldloc(loc.Local);
}
else
{
throw new XamlLoadException("Unable to convert {x:Null} to " + to.GetFqn(), node);
}
}
else
{
ld(false);
}
}
else if (what.IsValueType && to.IsValueType)
{
if (to.IsNullableOf(what))
{
ld(false).Emit(OpCodes.Newobj,
to.Constructors.First(c =>
c.Parameters.Count == 1 && c.Parameters[0].Equals(what)));
}
else if (what.IsNullableOf(what))
{
ld(true)
.EmitCall(what.FindMethod(m => m.Name == "get_Value"));
}
else
{
throw new XamlLoadException(
$"Don't know how to convert value type {what.GetFullName()} to value type {to.GetFullName()}",
node);
}
}
else if (!to.IsValueType && what.IsValueType)
{
if (!to.IsAssignableFrom(what))
{
throw new XamlLoadException(
$"Don't know how to convert value type {what.GetFullName()} to reference type {to.GetFullName()}",
node);
}
ld(false).Box(what);
}
else if (to.IsValueType && !what.IsValueType)
{
if (!(what.Namespace == "System" && what.Name == "Object"))
{
throw new XamlLoadException(
$"Don't know how to convert reference type {what.GetFullName()} to value type {to.GetFullName()}",
node);
}
ld(false).Unbox_Any(to);
}
else
{
if (to.IsAssignableFrom(what))
{
// Downcast, always safe
ld(false);
}
else if (what.IsInterface || what.IsAssignableFrom(to))
{
// Upcast or cast from interface, might throw InvalidCastException
ld(false).Emit(OpCodes.Castclass, to);
}
else
{
// Types are completely unrelated, e. g. string to List<int> conversion attempt
throw new XamlLoadException(
$"Don't know how to convert reference type {what.GetFullName()} to reference type {to.GetFullName()}",
node);
}
}
}