Files
Flee/InternalTypes/ImplicitConversions.cs

575 lines
20 KiB
C#

using System.Diagnostics;
using System.Reflection.Emit;
using System.Reflection;
using System;
namespace Flee.InternalTypes
{
internal class ImplicitConverter
{
/// <summary>
/// Table of results for binary operations using primitives
/// </summary>
private static readonly Type[,] OurBinaryResultTable;
/// <summary>
/// Primitive types we support
/// </summary>
private static readonly Type[] OurBinaryTypes;
static ImplicitConverter()
{
// Create a table with all the primitive types
Type[] types = {
typeof(char),
typeof(byte),
typeof(sbyte),
typeof(Int16),
typeof(UInt16),
typeof(Int32),
typeof(UInt32),
typeof(Int64),
typeof(UInt64),
typeof(float),
typeof(double)
};
OurBinaryTypes = types;
Type[,] table = new Type[types.Length, types.Length];
OurBinaryResultTable = table;
FillIdentities(types, table);
// Fill the table
AddEntry(typeof(UInt32), typeof(UInt64), typeof(UInt64));
AddEntry(typeof(Int32), typeof(Int64), typeof(Int64));
AddEntry(typeof(UInt32), typeof(Int64), typeof(Int64));
AddEntry(typeof(Int32), typeof(UInt32), typeof(Int64));
AddEntry(typeof(UInt32), typeof(float), typeof(float));
AddEntry(typeof(UInt32), typeof(double), typeof(double));
AddEntry(typeof(Int32), typeof(float), typeof(float));
AddEntry(typeof(Int32), typeof(double), typeof(double));
AddEntry(typeof(Int64), typeof(float), typeof(float));
AddEntry(typeof(Int64), typeof(double), typeof(double));
AddEntry(typeof(UInt64), typeof(float), typeof(float));
AddEntry(typeof(UInt64), typeof(double), typeof(double));
AddEntry(typeof(float), typeof(double), typeof(double));
// Byte
AddEntry(typeof(byte), typeof(byte), typeof(Int32));
AddEntry(typeof(byte), typeof(sbyte), typeof(Int32));
AddEntry(typeof(byte), typeof(Int16), typeof(Int32));
AddEntry(typeof(byte), typeof(UInt16), typeof(Int32));
AddEntry(typeof(byte), typeof(Int32), typeof(Int32));
AddEntry(typeof(byte), typeof(UInt32), typeof(UInt32));
AddEntry(typeof(byte), typeof(Int64), typeof(Int64));
AddEntry(typeof(byte), typeof(UInt64), typeof(UInt64));
AddEntry(typeof(byte), typeof(float), typeof(float));
AddEntry(typeof(byte), typeof(double), typeof(double));
// SByte
AddEntry(typeof(sbyte), typeof(sbyte), typeof(Int32));
AddEntry(typeof(sbyte), typeof(Int16), typeof(Int32));
AddEntry(typeof(sbyte), typeof(UInt16), typeof(Int32));
AddEntry(typeof(sbyte), typeof(Int32), typeof(Int32));
AddEntry(typeof(sbyte), typeof(UInt32), typeof(long));
AddEntry(typeof(sbyte), typeof(Int64), typeof(Int64));
//invalid -- AddEntry(GetType(SByte), GetType(UInt64), GetType(UInt64))
AddEntry(typeof(sbyte), typeof(float), typeof(float));
AddEntry(typeof(sbyte), typeof(double), typeof(double));
// int16
AddEntry(typeof(Int16), typeof(Int16), typeof(Int32));
AddEntry(typeof(Int16), typeof(UInt16), typeof(Int32));
AddEntry(typeof(Int16), typeof(Int32), typeof(Int32));
AddEntry(typeof(Int16), typeof(UInt32), typeof(long));
AddEntry(typeof(Int16), typeof(Int64), typeof(Int64));
//invalid -- AddEntry(GetType(Int16), GetType(UInt64), GetType(UInt64))
AddEntry(typeof(Int16), typeof(float), typeof(float));
AddEntry(typeof(Int16), typeof(double), typeof(double));
// Uint16
AddEntry(typeof(UInt16), typeof(UInt16), typeof(Int32));
AddEntry(typeof(UInt16), typeof(Int16), typeof(Int32));
AddEntry(typeof(UInt16), typeof(Int32), typeof(Int32));
AddEntry(typeof(UInt16), typeof(UInt32), typeof(UInt32));
AddEntry(typeof(UInt16), typeof(Int64), typeof(Int64));
AddEntry(typeof(UInt16), typeof(UInt64), typeof(UInt64));
AddEntry(typeof(UInt16), typeof(float), typeof(float));
AddEntry(typeof(UInt16), typeof(double), typeof(double));
// Char
AddEntry(typeof(char), typeof(char), typeof(Int32));
AddEntry(typeof(char), typeof(UInt16), typeof(UInt16));
AddEntry(typeof(char), typeof(Int32), typeof(Int32));
AddEntry(typeof(char), typeof(UInt32), typeof(UInt32));
AddEntry(typeof(char), typeof(Int64), typeof(Int64));
AddEntry(typeof(char), typeof(UInt64), typeof(UInt64));
AddEntry(typeof(char), typeof(float), typeof(float));
AddEntry(typeof(char), typeof(double), typeof(double));
}
private ImplicitConverter()
{
}
private static void FillIdentities(Type[] typeList, Type[,] table)
{
for (int i = 0; i <= typeList.Length - 1; i++)
{
Type t = typeList[i];
table[i, i] = t;
}
}
private static void AddEntry(Type t1, Type t2, Type result)
{
int index1 = GetTypeIndex(t1);
int index2 = GetTypeIndex(t2);
OurBinaryResultTable[index1, index2] = result;
OurBinaryResultTable[index2, index1] = result;
}
private static int GetTypeIndex(Type t)
{
return System.Array.IndexOf(OurBinaryTypes, t);
}
public static bool EmitImplicitConvert(Type sourceType, Type destType, FleeILGenerator ilg)
{
if (object.ReferenceEquals(sourceType, destType))
{
return true;
}
else if (EmitOverloadedImplicitConvert(sourceType, destType, ilg) == true)
{
return true;
}
else if (ImplicitConvertToReferenceType(sourceType, destType, ilg) == true)
{
return true;
}
else
{
return ImplicitConvertToValueType(sourceType, destType, ilg);
}
}
private static bool EmitOverloadedImplicitConvert(Type sourceType, Type destType, FleeILGenerator ilg)
{
// Look for an implicit operator on the destination type
MethodInfo mi = Utility.GetSimpleOverloadedOperator("Implicit", sourceType, destType);
if (mi == null)
{
// No match
return false;
}
if ((ilg != null))
{
ilg.Emit(OpCodes.Call, mi);
}
return true;
}
private static bool ImplicitConvertToReferenceType(Type sourceType, Type destType, FleeILGenerator ilg)
{
if (destType.IsValueType == true)
{
return false;
}
if (object.ReferenceEquals(sourceType, typeof(Null)))
{
// Null is always convertible to a reference type
return true;
}
if (destType.IsAssignableFrom(sourceType) == false)
{
return false;
}
if (sourceType.IsValueType == true)
{
if ((ilg != null))
{
ilg.Emit(OpCodes.Box, sourceType);
}
}
return true;
}
private static bool ImplicitConvertToValueType(Type sourceType, Type destType, FleeILGenerator ilg)
{
// We only handle value types
if (sourceType.IsValueType == false & destType.IsValueType == false)
{
return false;
}
// No implicit conversion to enum. Have to do this check here since calling GetTypeCode on an enum will return the typecode
// of the underlying type which screws us up.
if (sourceType.IsEnum == true | destType.IsEnum == true)
{
return false;
}
return EmitImplicitNumericConvert(sourceType, destType, ilg);
}
/// <summary>
///Emit an implicit conversion (if the ilg is not null) and returns a value that determines whether the implicit conversion
/// succeeded
/// </summary>
/// <param name="sourceType"></param>
/// <param name="destType"></param>
/// <param name="ilg"></param>
/// <returns></returns>
public static bool EmitImplicitNumericConvert(Type sourceType, Type destType, FleeILGenerator ilg)
{
TypeCode sourceTypeCode = Type.GetTypeCode(sourceType);
TypeCode destTypeCode = Type.GetTypeCode(destType);
switch (destTypeCode)
{
case TypeCode.Int16:
return ImplicitConvertToInt16(sourceTypeCode, ilg);
case TypeCode.UInt16:
return ImplicitConvertToUInt16(sourceTypeCode, ilg);
case TypeCode.Int32:
return ImplicitConvertToInt32(sourceTypeCode, ilg);
case TypeCode.UInt32:
return ImplicitConvertToUInt32(sourceTypeCode, ilg);
case TypeCode.Double:
return ImplicitConvertToDouble(sourceTypeCode, ilg);
case TypeCode.Single:
return ImplicitConvertToSingle(sourceTypeCode, ilg);
case TypeCode.Int64:
return ImplicitConvertToInt64(sourceTypeCode, ilg);
case TypeCode.UInt64:
return ImplicitConvertToUInt64(sourceTypeCode, ilg);
default:
return false;
}
}
private static bool ImplicitConvertToInt16(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.Byte:
case TypeCode.SByte:
case TypeCode.Int16:
return true;
default:
return false;
}
}
private static bool ImplicitConvertToUInt16(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.Char:
case TypeCode.Byte:
case TypeCode.UInt16:
return true;
default:
return false;
}
}
private static bool ImplicitConvertToInt32(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.Char:
case TypeCode.Byte:
case TypeCode.SByte:
case TypeCode.Int16:
case TypeCode.UInt16:
case TypeCode.Int32:
return true;
default:
return false;
}
}
private static bool ImplicitConvertToUInt32(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.Char:
case TypeCode.Byte:
case TypeCode.SByte:
case TypeCode.Int16:
case TypeCode.UInt16:
case TypeCode.UInt32:
return true;
default:
return false;
}
}
private static bool ImplicitConvertToDouble(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.Char:
case TypeCode.SByte:
case TypeCode.Byte:
case TypeCode.Int16:
case TypeCode.UInt16:
case TypeCode.Int32:
case TypeCode.Single:
case TypeCode.Int64:
EmitConvert(ilg, OpCodes.Conv_R8);
break;
case TypeCode.UInt32:
case TypeCode.UInt64:
EmitConvert(ilg, OpCodes.Conv_R_Un);
EmitConvert(ilg, OpCodes.Conv_R8);
break;
case TypeCode.Double:
break;
default:
return false;
}
return true;
}
private static bool ImplicitConvertToSingle(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.Char:
case TypeCode.Byte:
case TypeCode.SByte:
case TypeCode.Int16:
case TypeCode.UInt16:
case TypeCode.Int32:
case TypeCode.Int64:
EmitConvert(ilg, OpCodes.Conv_R4);
break;
case TypeCode.UInt32:
case TypeCode.UInt64:
EmitConvert(ilg, OpCodes.Conv_R_Un);
EmitConvert(ilg, OpCodes.Conv_R4);
break;
case TypeCode.Single:
break;
default:
return false;
}
return true;
}
private static bool ImplicitConvertToInt64(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.SByte:
case TypeCode.Int16:
case TypeCode.Int32:
EmitConvert(ilg, OpCodes.Conv_I8);
break;
case TypeCode.Char:
case TypeCode.Byte:
case TypeCode.UInt16:
case TypeCode.UInt32:
EmitConvert(ilg, OpCodes.Conv_U8);
break;
case TypeCode.Int64:
break;
default:
return false;
}
return true;
}
private static bool ImplicitConvertToUInt64(TypeCode sourceTypeCode, FleeILGenerator ilg)
{
switch (sourceTypeCode)
{
case TypeCode.Char:
case TypeCode.Byte:
case TypeCode.UInt16:
case TypeCode.UInt32:
EmitConvert(ilg, OpCodes.Conv_U8);
break;
case TypeCode.UInt64:
break;
default:
return false;
}
return true;
}
private static void EmitConvert(FleeILGenerator ilg, OpCode convertOpcode)
{
if ((ilg != null))
{
ilg.Emit(convertOpcode);
}
}
/// <summary>
/// Get the result type for a binary operation
/// </summary>
/// <param name="t1"></param>
/// <param name="t2"></param>
/// <returns></returns>
public static Type GetBinaryResultType(Type t1, Type t2)
{
int index1 = GetTypeIndex(t1);
int index2 = GetTypeIndex(t2);
if (index1 == -1 | index2 == -1)
{
return null;
}
else
{
return OurBinaryResultTable[index1, index2];
}
}
public static int GetImplicitConvertScore(Type sourceType, Type destType)
{
if (object.ReferenceEquals(sourceType, destType))
{
return 0;
}
if (object.ReferenceEquals(sourceType, typeof(Null)))
{
return GetInverseDistanceToObject(destType);
}
if (Utility.GetSimpleOverloadedOperator("Implicit", sourceType, destType) != null)
{
// Implicit operator conversion, score it at 1 so it's just above the minimum
return 1;
}
if (sourceType.IsValueType == true)
{
if (destType.IsValueType == true)
{
// Value type -> value type
int sourceScore = GetValueTypeImplicitConvertScore(sourceType);
int destScore = GetValueTypeImplicitConvertScore(destType);
return destScore - sourceScore;
}
else
{
// Value type -> reference type
return GetReferenceTypeImplicitConvertScore(sourceType, destType);
}
}
else
{
if (destType.IsValueType == true)
{
// Reference type -> value type
// Reference types can never be implicitly converted to value types
Debug.Fail("No implicit conversion from reference type to value type");
}
else
{
// Reference type -> reference type
return GetReferenceTypeImplicitConvertScore(sourceType, destType);
}
}
return 0;
}
private static int GetValueTypeImplicitConvertScore(Type t)
{
TypeCode tc = Type.GetTypeCode(t);
switch (tc)
{
case TypeCode.Byte:
return 1;
case TypeCode.SByte:
return 2;
case TypeCode.Char:
return 3;
case TypeCode.Int16:
return 4;
case TypeCode.UInt16:
return 5;
case TypeCode.Int32:
return 6;
case TypeCode.UInt32:
return 7;
case TypeCode.Int64:
return 8;
case TypeCode.UInt64:
return 9;
case TypeCode.Single:
return 10;
case TypeCode.Double:
return 11;
case TypeCode.Decimal:
return 11;
case TypeCode.Boolean:
return 12;
case TypeCode.DateTime:
return 13;
default:
Debug.Assert(false, "unknown value type");
return -1;
}
}
private static int GetReferenceTypeImplicitConvertScore(Type sourceType, Type destType)
{
if (destType.IsInterface == true)
{
return 100;
}
else
{
return GetInheritanceDistance(sourceType, destType);
}
}
private static int GetInheritanceDistance(Type sourceType, Type destType)
{
int count = 0;
Type current = sourceType;
while ((!object.ReferenceEquals(current, destType)))
{
count += 1;
current = current.BaseType;
}
return count * 1000;
}
private static int GetInverseDistanceToObject(Type t)
{
int score = 1000;
Type current = t.BaseType;
while ((current != null))
{
score -= 100;
current = current.BaseType;
}
return score;
}
}
}