public static void EmitCast(this CompilationContext context, Type targetType)
{
if (context.CurrentType == targetType)
{
return;
}
var currentTypeIsValue = context.CurrentType.GetTypeInfo().IsValueType;
var targetTypeIsValue = targetType.GetTypeInfo().IsValueType;
if (!currentTypeIsValue && targetTypeIsValue)
{
context.Emit(OpCodes.Unbox_Any, targetType);
}
else if (currentTypeIsValue && !targetTypeIsValue)
{
context.Emit(OpCodes.Box, context.CurrentType);
if (targetType != typeof(object) && targetType != typeof(Enum) && targetType != typeof(void))
{
context.Emit(OpCodes.Castclass, targetType);
}
}
else
{
if (context.CurrentType == typeof(long) || context.CurrentType == typeof(ulong) ||
context.CurrentType == typeof(int) || context.CurrentType == typeof(uint) ||
context.CurrentType == typeof(short) || context.CurrentType == typeof(ushort) ||
context.CurrentType == typeof(byte) || context.CurrentType == typeof(sbyte) ||
context.CurrentType == typeof(float) || context.CurrentType == typeof(double) ||
context.CurrentType == typeof(char) || context.CurrentType == typeof(bool))
{
if (targetType == typeof(sbyte))
{
context.Emit(OpCodes.Conv_I1);
}
if (targetType == typeof(byte))
{
context.Emit(OpCodes.Conv_U1);
}
if (targetType == typeof(short) || targetType == typeof(char))
{
context.Emit(OpCodes.Conv_I2);
}
if (targetType == typeof(ushort))
{
context.Emit(OpCodes.Conv_U2);
}
if (targetType == typeof(int))
{
context.Emit(OpCodes.Conv_I4);
}
if (targetType == typeof(uint))
{
context.Emit(OpCodes.Conv_U4);
}
if (targetType == typeof(long))
{
context.Emit(OpCodes.Conv_I8);
}
if (targetType == typeof(ulong))
{
context.Emit(OpCodes.Conv_U8);
}
if (targetType == typeof(float))
{
context.Emit(OpCodes.Conv_R4);
}
if (targetType == typeof(double))
{
context.Emit(OpCodes.Conv_R8);
}
}
else if (currentTypeIsValue)
{
throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, "Cannot cast from type '{0}' to type '{1}'.", context.CurrentType, targetType));
}
else if (targetType != typeof(object))
{
context.Emit(OpCodes.Castclass, targetType);
}
}
context.CurrentType = targetType;
}
public static void EmitCall(this CompilationContext context, MethodInfo method)
{
context.Emit(method.IsVirtual ? OpCodes.Callvirt : OpCodes.Call, method);
context.CurrentType = method.ReturnType;
}
public static void EmitTypeOf(this CompilationContext context, Type targetType)
{
context.Emit(OpCodes.Ldtoken, targetType);
context.Emit(OpCodes.Call, _getTypeFromHandleMethod);
}
public static void EmitDefault(this CompilationContext context, Type targetType)
{
var originalType = targetType;
if (targetType.IsNullable())
{
var local = context.DeclareLocal(targetType);
context.Emit(OpCodes.Ldloca, local);
context.Emit(OpCodes.Initobj, targetType);
context.Emit(OpCodes.Ldloc, local);
context.CurrentType = originalType;
return;
}
if (!targetType.GetTypeInfo().IsValueType)
{
context.Emit(OpCodes.Ldnull);
context.CurrentType = originalType;
return;
}
if (targetType.GetTypeInfo().IsEnum)
{
targetType = Enum.GetUnderlyingType(targetType);
}
if (targetType == typeof(int) || targetType == typeof(uint) ||
targetType == typeof(short) || targetType == typeof(ushort) ||
targetType == typeof(byte) || targetType == typeof(sbyte) ||
targetType == typeof(char) || targetType == typeof(bool))
{
context.Emit(OpCodes.Ldc_I4_0);
context.CurrentType = originalType;
return;
}
if (targetType == typeof(long) || targetType == typeof(ulong))
{
context.Emit(OpCodes.Ldc_I4_0);
context.Emit(OpCodes.Conv_I8);
context.CurrentType = originalType;
return;
}
if (targetType == typeof(float))
{
context.Emit(OpCodes.Ldc_I4_0);
context.Emit(OpCodes.Conv_R4);
context.CurrentType = originalType;
return;
}
if (targetType == typeof(double))
{
context.Emit(OpCodes.Ldc_I4_0);
context.Emit(OpCodes.Conv_R8);
context.CurrentType = originalType;
return;
}
Func <MethodInfo, bool> coverterPredicate = method =>
{
if (method.Name == "op_Implicit")
{
var parameters = method.GetParameters();
return(parameters.Length == 1 && parameters[0].ParameterType == typeof(int));
}
return(false);
};
var reflectingType = targetType.GetTypeInfo();
if (targetType == typeof(decimal))
{
context.Emit(OpCodes.Ldc_I4_0);
context.EmitCall(reflectingType.GetMethods(BindingFlags.Static | BindingFlags.Public).FirstOrDefault(coverterPredicate));
context.CurrentType = originalType;
return;
}
var field = reflectingType.GetField("Empty", BindingFlags.Public | BindingFlags.Static) ??
reflectingType.GetField("Zero", BindingFlags.Public | BindingFlags.Static) ??
reflectingType.GetField("MinValue", BindingFlags.Public | BindingFlags.Static);
if (field != null)
{
context.Emit(OpCodes.Ldsfld, field);
context.CurrentType = field.FieldType;
context.EmitCast(originalType);
return;
}
var property = reflectingType.GetProperty("Empty", BindingFlags.Public | BindingFlags.Static) ??
reflectingType.GetProperty("Zero", BindingFlags.Public | BindingFlags.Static) ??
reflectingType.GetProperty("MinValue", BindingFlags.Public | BindingFlags.Static);
var getMethod = property?.GetGetMethod();
if (getMethod != null)
{
context.EmitCall(getMethod);
context.CurrentType = getMethod.ReturnType;
context.EmitCast(originalType);
return;
}
var targetLocal = context.DeclareLocal(targetType);
context.Emit(OpCodes.Ldloca, targetLocal);
context.Emit(OpCodes.Initobj, targetType);
context.Emit(OpCodes.Ldloc, targetLocal);
context.CurrentType = originalType;
}
