/// <summary>
/// Convenience method for creating an opcode from a position in a byte array.
/// Returns an opcode object with references resolved and advances the position
/// to the next place in the byte array.
/// </summary>
/// <param name="reader">Where to read the next opcode from</param>
/// <param name="abc">The code within which we're reading</param>
/// <returns>A new Opcode object, or null if there was no more data to be read</returns>
public static Opcode BuildOpcode(ABCDataTypeReader reader, AbcCode abc)
{
Opcode op = new Opcode(abc);
int code;
code = reader.ReadUI8();
if (code == -1)
{
return null;
}
op.Instruction = (uint)code;
if (OpcodeTable[code] == null)
{
throw new SWFModellerException(
SWFModellerError.Internal,
"Bad opcode 0x" + code.ToString("X") + " at @" + (reader.Offset - 1));
}
OpcodeDef info = (OpcodeDef)OpcodeTable[code];
List<object> args = new List<object>();
if (info.Mnemonic == Mnemonics.LookupSwitch)
{
/* Special case: Has a variable arg */
args.Add(reader.ReadSI24()); /* default offset */
uint caseCount = reader.ReadU30();
args.Add(caseCount);
for (int i = 0; i < caseCount + 1; i++)
{
args.Add(reader.ReadSI24());
}
}
else
{
if (info.Args != null)
{
foreach (ArgType type in info.Args)
{
switch (type)
{
case ArgType.MultinameU30:
args.Add(abc.GetMultiname((int)reader.ReadU30()));
break;
case ArgType.OffsetS24:
args.Add(reader.ReadSI24());
break;
case ArgType.StringU30:
args.Add(abc.StringConsts[reader.ReadU30()]);
break;
case ArgType.RegisterU30:
case ArgType.ObjectRegisterU30:
case ArgType.PropertyRegisterU30:
args.Add(reader.ReadU30());
break;
case ArgType.ByteU8:
args.Add((byte)reader.ReadUI8());
break;
case ArgType.ShortU30:
case ArgType.IntU30:
case ArgType.UintU30:
case ArgType.DoubleU30:
args.Add(reader.ReadU30());
break;
case ArgType.ShortS30:
args.Add((int)reader.ReadU30());
break;
case ArgType.ByteS8:
args.Add(reader.ReadSI8());
break;
case ArgType.NamespaceU30:
args.Add(abc.GetNamespace((int)reader.ReadU30()));
break;
case ArgType.MethodU30:
args.Add(abc.GetMethod((int)reader.ReadU30()));
break;
case ArgType.CountU30:
args.Add(reader.ReadU30());
break;
case ArgType.ClassU30:
args.Add(abc.GetClass((int)reader.ReadU30()));
break;
case ArgType.ExceptionU30:
args.Add(reader.ReadU30());
break;
case ArgType.StackU8:
args.Add((byte)reader.ReadUI8());
break;
case ArgType.SlotU30:
args.Add(reader.ReadU30());
break;
case ArgType.DebugU8:
args.Add((byte)reader.ReadUI8());
break;
case ArgType.DebugTypeU30:
args.Add(reader.ReadU30());
break;
case ArgType.StringU8:
args.Add(abc.StringConsts[reader.ReadUI8()]);
break;
case ArgType.LineNumberU30:
args.Add(reader.ReadU30());
break;
default:
/* ISSUE 73 */
throw new SWFModellerException(
SWFModellerError.UnimplementedFeature,
"Oops. Not done " + type.ToString());
}
}
}
}
op.Args = args.ToArray();
return op;
}
/// <summary>
/// Convenience method for debug file opcodes, which can be inserted sneakily at the
/// last moment when serialising the bytecode, and so need to be created in this lightweight
/// way.
/// </summary>
public static Opcode CreateDebugFile(string fileName)
{
Opcode op = new Opcode(null);
op.Instruction = (uint)Mnemonics.DebugFile;
op.Args = new object[] { fileName };
return op;
}
/// <summary>
/// Convenience method for debug line opcodes, which can be inserted sneakily at the
/// last moment when serialising the bytecode, and so need to be created in this lightweight
/// way.
/// </summary>
public static Opcode CreateDebugLine(uint line)
{
Opcode op = new Opcode(null);
op.Instruction = (uint)Mnemonics.DebugLine;
op.Args = new object[] { line };
return op;
}
/// <summary>
/// Technically, from an OO perspective, this isn't the most logical place
/// for this method. It's a factory method for opcodes used when building up
/// new methods, bytecode by bytecode. It's here because this is the place
/// that makes calling it require the least typing, which is good when you're
/// creating lists of loads of these things.
/// </summary>
/// <param name="mnemonic">The opcode mnemonic</param>
/// <param name="args">The argument list. If the types of the args don't
/// match the type requirements of the opcode, an exception will be
/// thrown.</param>
/// <returns>An opcode</returns>
internal Opcode Op(Opcode.Mnemonics mnemonic, params object[] args)
{
Opcode op = new Opcode(this) { Mnemonic = mnemonic, Args = args.Length == 0 ? null : args };
if (mnemonic != Opcode.Mnemonics.LookupSwitch)
{
if (!Opcode.VerifyArgTypes(mnemonic, args))
{
throw new SWFModellerException(
SWFModellerError.Internal,
"Invalid arg values or types in opcode " + mnemonic.ToString());
}
}
/* ISSUE 7: There must be some way to verify lookupswitch to some degree.
* Update: There is. The case count must be correct and the offsets must be references
* to preceeding Label opcodes. */
return op;
}
