public static Instruction DissasembleFromReader(int address, BinaryReader r)
{
Instruction ret = new Instruction(address);
uint raw = r.ReadUInt32();
ret.Code = GMCodeUtil.getFromRaw(raw);
if (DissasembleRawCode(ret, raw))
{
switch (ret.Code)
{
case GMCode.Call:
case GMCode.Pop:
ret.Operand = r.ReadInt32();
break;
case GMCode.Push:
{
switch (ret.Types[0])
{
case GM_Type.Long:
ret.Operand = r.ReadInt64();
break;
case GM_Type.Double:
ret.Operand = r.ReadDouble();
break;
case GM_Type.Float:
ret.Operand = r.ReadSingle();
break;
case GM_Type.Bool:
ret.Operand = r.ReadInt32() != 0 ? true : false; // tested, yess this is silly
break;
case GM_Type.String:
case GM_Type.Var:
case GM_Type.Int:
ret.Operand = r.ReadInt32();
break;
case GM_Type.Short:
break; // already read in DissasembleRawCode
}
}
break;
}
Debug.Assert(ret.Operand != null);
}
return(ret);
}
/// <summary>
/// Diassembles a raw opcode.
/// </summary>
/// <param name="i"></param>
/// <param name="raw"></param>
/// <returns>Returns truee if operand is needed</returns>
public static bool DissasembleRawCode(Instruction i, uint raw)
{
i.Code = GMCodeUtil.getFromRaw(raw);
i.Types = null;
i.Operand = null;
i.OperandText = null; // we clear eveything just in case
i._extra = (short)(0xFFFF & raw); // default for almost eveything
switch (i.Code)
{
case GMCode.Call:
i.Types = new GM_Type[] { (GM_Type)((raw >> 16) & 15) };
return(true);
case GMCode.Exit:
case GMCode.Ret:
case GMCode.Not:
case GMCode.Neg:
case GMCode.Popz:
i.Types = new GM_Type[] { (GM_Type)((raw >> 16) & 15) };
break;
case GMCode.Pop:
i.Types = new GM_Type[] { (GM_Type)((raw >> 16) & 15), (GM_Type)((raw >> 20) & 15) };
return(true);
case GMCode.Push:
i.Types = new GM_Type[] { (GM_Type)((raw >> 16) & 15) };
// this should be in the operand, but just in case make sure extra is right
if (i.Types[0] == GM_Type.Short)
{
i.Operand = i._extra; // convert it to int
break; // set the operand ourselfs don't need it
}
else
{
return(true); // need to read an operand
}
case GMCode.Add:
case GMCode.Sub:
case GMCode.Mul:
case GMCode.Div:
case GMCode.Mod:
case GMCode.Or:
case GMCode.And:
case GMCode.Dup:
case GMCode.Sal:
case GMCode.Seq:
case GMCode.Sge:
case GMCode.Sgt:
case GMCode.Sle:
case GMCode.Sne:
case GMCode.Conv:
case GMCode.Rem:
case GMCode.Slt:
case GMCode.Xor:
i.Types = new GM_Type[] { (GM_Type)((raw >> 16) & 15), (GM_Type)((raw >> 20) & 15) };
break;
case GMCode.Break:
// i._extra = (int)(0x00FFFFFFF & raw); // never seen the need for more than this
break;
case GMCode.B:
case GMCode.Bf:
case GMCode.Bt:
i._extra = i.Address + GMCodeUtil.getBranchOffset(raw);
break;
case GMCode.Popenv:
// Debug.WriteLine("Popenv: Address: {0}, Extra: {1} {1:X8} Calc: {2}",i.Address, raw, GMCodeUtil.getBranchOffset(raw));
if (0xBCF00000 == raw) // its a popbreak
{
i._extra = 0;
}
else
{
i._extra = i.Address + GMCodeUtil.getBranchOffset(raw);
}
break;
case GMCode.Pushenv:
// Debug.WriteLine("Pushenv: Address: {0}, Extra: {1} {1:X8} Calc: {2}",i.Address, raw, GMCodeUtil.getBranchOffset(raw));
i._extra = i.Address + GMCodeUtil.getBranchOffset(raw);
break;
case GMCode.BadOp:
throw new Exception("Bad opcode?");
default:
throw new Exception("Unkonwn opcode");
}
return(false);
}