private void ReadOperand(Instruction instruction)
{
switch (instruction.OpCode.OperandType)
{
case OperandType.InlineNone:
break;
case OperandType.InlineSwitch:
int length = _il.ReadInt32();
int base_offset = _il.Position + (4 * length);
int[] branches = new int[length];
for (int i = 0; i < length; i++)
branches[i] = _il.ReadInt32() + base_offset;
instruction.Operand = branches;
break;
case OperandType.ShortInlineBrTarget:
instruction.Operand = (((sbyte)_il.ReadByte()) + _il.Position);
break;
case OperandType.InlineBrTarget:
instruction.Operand = _il.ReadInt32() + _il.Position;
break;
case OperandType.ShortInlineI:
if (instruction.OpCode == OpCodes.Ldc_I4_S)
instruction.Operand = (sbyte)_il.ReadByte();
else
instruction.Operand = _il.ReadByte();
break;
case OperandType.InlineI:
instruction.Operand = _il.ReadInt32();
break;
case OperandType.ShortInlineR:
instruction.Operand = _il.ReadSingle();
break;
case OperandType.InlineR:
instruction.Operand = _il.ReadDouble();
break;
case OperandType.InlineI8:
instruction.Operand = _il.ReadInt64();
break;
case OperandType.InlineSig:
instruction.Operand = _module.ResolveSignature(_il.ReadInt32());
break;
case OperandType.InlineString:
instruction.Operand = _module.ResolveString(_il.ReadInt32());
break;
case OperandType.InlineTok:
case OperandType.InlineType:
case OperandType.InlineMethod:
case OperandType.InlineField:
instruction.Operand = _module.ResolveMember(_il.ReadInt32(), _typeArguments, _methodArguments);
break;
case OperandType.ShortInlineVar:
instruction.Operand = GetVariable(instruction, _il.ReadByte());
break;
case OperandType.InlineVar:
instruction.Operand = GetVariable(instruction, _il.ReadInt16());
break;
default:
throw new NotSupportedException();
}
}
private void ParseBody()
{
while (_il.Position < _il.Length)
{
var pos = _il.Position;
byte op = _il.ReadByte();
var opCode = op != 0xfe
? OneByteCodes[op]
: TwoByteCodes[_il.ReadByte()];
var instruction = new Instruction(pos, opCode);
ReadOperand(instruction);
_instructions.Add(instruction);
}
ResolveBranches();
}
private void ResolveBranches()
{
foreach (var instruction in _instructions)
{
switch (instruction.OpCode.OperandType)
{
case OperandType.ShortInlineBrTarget:
case OperandType.InlineBrTarget:
instruction.Operand = GetInstruction(_instructions, (int)instruction.Operand);
break;
case OperandType.InlineSwitch:
var offsets = (int[])instruction.Operand;
var branches = new Instruction[offsets.Length];
for (int j = 0; j < offsets.Length; j++)
branches[j] = GetInstruction(_instructions, offsets[j]);
instruction.Operand = branches;
break;
}
}
}
private object GetVariable(Instruction instruction, int index)
{
return TargetsLocalVariable(instruction.OpCode)
? (object)_locals[index]
: (object)GetParameter(index);
}
private void AppendLabel(StringBuilder builder, Instruction instruction)
{
builder.Append("IL_");
builder.Append(instruction.Offset.ToString("x4"));
}