// constructor also goes here
private EvmByteCode WrapByteCode(EvmByteCode toWrap)
{
var preAssembly = new EthSharpAssembly();
preAssembly.Append(toWrap.ByteCode.Count); // push length of bytecode
preAssembly.Append(0x0c); // push offset of bytecode - TODO: THIS COULD CHANGE IF THIS BLOCK CHANGES!
preAssembly.Append(UInt256.Zero); // push memory location to store in (0)
preAssembly.Append(EvmInstruction.CODECOPY); // codecopy
preAssembly.Append(toWrap.ByteCode.Count); // push length of code to pick
preAssembly.Append(UInt256.Zero); // push location of code (0)
preAssembly.Append(EvmInstruction.RETURN);
var preByteCode = preAssembly.Assemble();
toWrap.ByteCode.InsertRange(0, preByteCode.ByteCode);
return(toWrap);
}
public EvmByteCode Assemble()
{
EvmByteCode ret = new EvmByteCode();
Dictionary <int, List <int> > jumpFromLocations = new Dictionary <int, List <int> >();
Dictionary <int, int> tagLocations = new Dictionary <int, int>();
foreach (var item in Items)
{
switch (item.Type)
{
case AssemblyItemType.Operation:
ret.ByteCode.Add((byte)item.Instruction);
break;
case AssemblyItemType.Push:
{
int length = item.Data.ByteLength;
var sizedPushInstruction = EvmInstruction.PUSH1 - 1 + length;
ret.ByteCode.Add((byte)sizedPushInstruction);
ret.ByteCode.AddRange(item.Data.ToByteArrayBE().Skip(32 - length).Take(length));
break;
}
case AssemblyItemType.PushTag:
{
ret.ByteCode.Add((byte)EvmInstruction.PUSH1);
if (jumpFromLocations.ContainsKey(item.Data.ToInt()))
{
jumpFromLocations[item.Data.ToInt()].Add(ret.ByteCode.Count);
}
else
{
jumpFromLocations[item.Data.ToInt()] = new List <int> {
ret.ByteCode.Count
};
}
ret.ByteCode.Add((byte)0); //This will get replaced with the location to jump to!
break;
}
case AssemblyItemType.Tag:
tagLocations.Add(item.Data.ToInt(), ret.ByteCode.Count);
ret.ByteCode.Add((byte)EvmInstruction.JUMPDEST);
break;
}
}
//Update all jumps to correct location
foreach (var tag in tagLocations)
{
int tagId = tag.Key;
int tagLocation = tag.Value;
foreach (var jumpFrom in jumpFromLocations[tagId])
{
ret.ByteCode[jumpFrom] = (byte)tagLocation;
}
}
return(ret);
}
