private object ResolveOperand(ByteCodeInstructionCollection allInstructions, ByteCodeInstruction instruction)
{
switch (instruction.OpCode.OperandType)
{
case ByteCodeOperandType.PrimitiveType:
return((PrimitiveType)(byte)instruction.Operand);
case ByteCodeOperandType.ConstantIndex:
case ByteCodeOperandType.WideConstantIndex:
return(OperandResolver?.ResolveConstant(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.FieldIndex:
return(OperandResolver?.ResolveField(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.MethodIndex:
return(OperandResolver?.ResolveMethod(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.ClassIndex:
return(OperandResolver?.ResolveClass(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.BranchOffset:
case ByteCodeOperandType.WideBranchOffset:
int offset = Convert.ToInt32(instruction.Operand);
return(allInstructions.GetByOffset(instruction.Offset + offset) ?? instruction.Operand);
}
return(instruction.Operand);
}
private object ResolveOperand(ByteCodeInstructionCollection allInstructions, ByteCodeInstruction instruction)
{
switch (instruction.OpCode.OperandType)
{
case ByteCodeOperandType.PrimitiveType:
return((PrimitiveType)(byte)instruction.Operand);
case ByteCodeOperandType.ConstantIndex:
case ByteCodeOperandType.WideConstantIndex:
return(OperandResolver?.ResolveConstant(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.FieldIndex:
return(OperandResolver?.ResolveField(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.MethodIndex:
return(OperandResolver?.ResolveMethod(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.ClassIndex:
return(OperandResolver?.ResolveClass(Convert.ToInt32(instruction.Operand)) ?? instruction.Operand);
case ByteCodeOperandType.DynamicIndex:
return(OperandResolver?.ResolveDynamic(Convert.ToInt32(instruction.Operand) >> 16) ?? instruction.Operand);
case ByteCodeOperandType.BranchOffset:
case ByteCodeOperandType.WideBranchOffset:
int offset = Convert.ToInt32(instruction.Operand);
return(allInstructions.GetByOffset(instruction.Offset + offset) ?? instruction.Operand);
case ByteCodeOperandType.TableSwitch:
var table = (TableSwitch)instruction.Operand;
table.DefaultOffset += instruction.Offset;
for (int i = 0; i < table.Offsets.Count; i++)
{
table.Offsets[i] += instruction.Offset;
}
return(table);
case ByteCodeOperandType.LookupSwitch:
var lookup = (LookupSwitch)instruction.Operand;
lookup.DefaultOffset += instruction.Offset;
foreach (int key in lookup.Table.Keys)
{
lookup.Table[key] += instruction.Offset;
}
return(lookup);
}
return(instruction.Operand);
}
private void WriteOperand(ByteCodeInstruction instruction)
{
switch (instruction.OpCode.OperandType)
{
case ByteCodeOperandType.None:
break;
case ByteCodeOperandType.Byte:
case ByteCodeOperandType.LocalIndex:
case ByteCodeOperandType.PrimitiveType:
_writer.Write(Convert.ToByte(instruction.Operand));
break;
case ByteCodeOperandType.Short:
case ByteCodeOperandType.LocalConst:
_writer.Write(Convert.ToInt16(instruction.Operand));
break;
case ByteCodeOperandType.FieldIndex:
_writer.Write(instruction.Operand is FieldReference fieldRef
? (ushort)OperandBuilder.GetFieldIndex(fieldRef)
: Convert.ToUInt16(instruction.Operand));
break;
case ByteCodeOperandType.MethodIndex:
_writer.Write(instruction.Operand is MethodReference methodRef
? (ushort)OperandBuilder.GetMethodIndex(methodRef)
: Convert.ToUInt16(instruction.Operand));
break;
case ByteCodeOperandType.ClassIndex:
_writer.Write(instruction.Operand is ClassReference classRef
? (ushort)OperandBuilder.GetClassIndex(classRef)
: Convert.ToUInt16(instruction.Operand));
break;
case ByteCodeOperandType.ConstantIndex:
_writer.Write((byte)OperandBuilder.GetLiteralIndex(instruction.Operand));
break;
case ByteCodeOperandType.WideConstantIndex:
_writer.Write((ushort)OperandBuilder.GetLiteralIndex(instruction.Operand));
break;
case ByteCodeOperandType.BranchOffset:
{
short relativeOffset;
if (instruction.Operand is ByteCodeInstruction target)
{
relativeOffset = (short)(target.Offset - instruction.Offset);
}
else
{
relativeOffset = Convert.ToInt16(instruction.Operand);
}
_writer.Write(relativeOffset);
break;
}
case ByteCodeOperandType.WideBranchOffset:
{
int relativeOffset;
if (instruction.Operand is ByteCodeInstruction target)
{
relativeOffset = (target.Offset - instruction.Offset);
}
else
{
relativeOffset = Convert.ToInt32(instruction.Operand);
}
_writer.Write(relativeOffset);
break;
}
case ByteCodeOperandType.TableSwitch:
case ByteCodeOperandType.LookupSwitch:
_writer.Position = FileSegment.Align((uint)_writer.Position, 4);
((ISwitchOperand)instruction.Operand).Write(_writer, instruction.Offset);
break;
case ByteCodeOperandType.WideIndexCountZero:
case ByteCodeOperandType.WideIndexByte:
_writer.Write(Convert.ToInt32(instruction.Operand));
break;
case ByteCodeOperandType.DynamicIndex:
_writer.Write(instruction.Operand is DynamicInvocation invocation
? OperandBuilder.GetDynamicIndex(invocation) << 16
: Convert.ToInt32(instruction.Operand));
break;
default:
throw new ArgumentOutOfRangeException();
}
}
/// <summary>
/// Writes a single instruction to the output stream.
/// </summary>
/// <param name="instruction">The instruction to write.</param>
/// <remarks>
/// Some instructions have different byte layouts depending on the offsets they are located at.
/// Make sure the offsets have been calculated before passing on the instructions to the assembler.
/// </remarks>
public void Write(ByteCodeInstruction instruction)
{
_writer.Write((byte)instruction.OpCode.Code);
WriteOperand(instruction);
}