private ABCFile.MethodBody readMethodBody()
{
var r = new ABCFile.MethodBody();
r.method = readU30();
r.maxStack = readU30();
r.localCount = readU30();
r.initScopeDepth = readU30();
r.maxScopeDepth = readU30();
r.instructions = null;
uint len = readU30();
var instructionAtOffset = new uint[len];
r.rawBytes = new byte[len];
Buffer.BlockCopy(buf, (int)pos, r.rawBytes, 0, (int)len);
Func <ABCFile.Label, ABCFile.Label> translateLabel = (ABCFile.Label label) =>
{
uint absoluteOffset = label.absoluteOffset;
uint instructionOffset = absoluteOffset;
while (true)
{
if (instructionOffset >= len)
{
label.index = (uint)r.instructions.Length;
instructionOffset = len;
break;
}
if (instructionOffset <= 0)
{
label.index = 0;
instructionOffset = 0;
break;
}
if (instructionAtOffset[instructionOffset] != uint.MaxValue)
{
label.index = instructionAtOffset[instructionOffset];
break;
}
instructionOffset--;
}
label.offset = (int)(absoluteOffset - instructionOffset);
return(label);
};
uint start = pos;
uint end = pos + len;
Func <uint> offset = () => { return(pos - start); };
try
{
for (int i = 0; i < instructionAtOffset.Length; i++)
{
instructionAtOffset[i] = uint.MaxValue;
}
var instructionOffsets = new List <uint>();
var instrs = new List <ABCFile.Instruction>();
while (pos < end)
{
uint instructionOffset = offset();
pos = start + instructionOffset;
instructionAtOffset[instructionOffset] = (uint)instrs.Count;
ABCFile.Instruction instruction;
instruction.opcode = (Opcode)readU8();
var opcodeInfo = OpcodeInfo.opcodeDict[instruction.opcode];
instruction.arguments = new ABCFile.Instruction.Argument[opcodeInfo.argumentTypes.Length];
for (int i = 0; i < instruction.arguments.Length; i++)
{
var type = opcodeInfo.argumentTypes[i];
switch (type)
{
case OpcodeArgumentType.Unknown:
throw new Exception("Don't know how to decode OP_" + opcodeInfo.name);
case OpcodeArgumentType.UByteLiteral:
instruction.arguments[i].ubytev = readU8();
break;
case OpcodeArgumentType.IntLiteral:
instruction.arguments[i].intv = readS32();
break;
case OpcodeArgumentType.UIntLiteral:
instruction.arguments[i].uintv = readU32();
break;
case OpcodeArgumentType.Int:
case OpcodeArgumentType.UInt:
case OpcodeArgumentType.Double:
case OpcodeArgumentType.String:
case OpcodeArgumentType.Namespace:
case OpcodeArgumentType.Multiname:
case OpcodeArgumentType.Class:
case OpcodeArgumentType.Method:
instruction.arguments[i].index = readU30();
break;
case OpcodeArgumentType.JumpTarget:
int delta = readS24();
instruction.arguments[i].jumpTarget.absoluteOffset = (uint)(offset() + delta);
break;
case OpcodeArgumentType.SwitchDefaultTarget:
instruction.arguments[i].jumpTarget.absoluteOffset = (uint)(instructionOffset + readS24());
break;
case OpcodeArgumentType.SwitchTargets:
instruction.arguments[i].switchTargets = new ABCFile.Label[readU30() + 1];
for (int j = 0; j < instruction.arguments[i].switchTargets.Length; j++)
{
instruction.arguments[i].switchTargets[j].absoluteOffset = (uint)(instructionOffset + readS24());
}
break;
}
}
instrs.Add(instruction);
instructionOffsets.Add(instructionOffset);
}
r.instructions = instrs.ToArray();
if (pos > end)
{
throw new Exception("Out-of-bounds code read error");
}
// convert jump target offsets to instruction indices
for (int i = 0; i < r.instructions.Length; i++)
{
var opcodeInfo = OpcodeInfo.opcodeDict[r.instructions[i].opcode];
for (int j = 0; j < opcodeInfo.argumentTypes.Length; j++)
{
switch (opcodeInfo.argumentTypes[j])
{
case OpcodeArgumentType.JumpTarget:
case OpcodeArgumentType.SwitchDefaultTarget:
r.instructions[i].arguments[j].jumpTarget = translateLabel(r.instructions[i].arguments[j].jumpTarget);
break;
case OpcodeArgumentType.SwitchTargets:
for (int k = 0; k < r.instructions[i].arguments[j].switchTargets.Length; k++)
{
r.instructions[i].arguments[j].switchTargets[k] =
translateLabel(r.instructions[i].arguments[j].switchTargets[k]);
}
break;
default:
break;
}
}
}
}
catch (Exception e)
{
r.instructions = null;
r.error = e.Message;
instructionAtOffset.Initialize();
}
pos = end;
r.exceptions = new ABCFile.ExceptionInfo[readU30()];
for (int i = 0; i < r.exceptions.Length; i++)
{
r.exceptions[i] = readExceptionInfo();
r.exceptions[i].from = translateLabel(r.exceptions[i].from);
r.exceptions[i].to = translateLabel(r.exceptions[i].to);
r.exceptions[i].target = translateLabel(r.exceptions[i].target);
}
r.traits = new ABCFile.TraitsInfo[readU30()];
for (int i = 0; i < r.traits.Length; i++)
{
r.traits[i] = readTrait();
}
return(r);
}
private void writeMethodBody(ABCFile.MethodBody v)
{
writeU30(v.method);
writeU30(v.maxStack);
writeU30(v.localCount);
writeU30(v.initScopeDepth);
writeU30(v.maxScopeDepth);
var instructionOffsets = new uint[v.instructions.Length + 1];
Func <ABCFile.Label, uint> resolveLabel =
(ABCFile.Label label) => { return((uint)(instructionOffsets[label.index] + label.offset)); };
{
// we don't know the length before writing all the instructions - swap buffer with a temporary one
byte[] globalBuf = buf;
uint globalPos = pos;
var methodBuf = new byte[1024 * 16];
buf = methodBuf;
pos = 0;
var fixups = new List <Fixup>();
for (int i = 0; i < v.instructions.Length; i++)
{
var instruction = v.instructions[i];
uint instructionOffset = pos;
instructionOffsets[i] = instructionOffset;
var opcodeInfo = OpcodeInfo.opcodeDict[instruction.opcode];
writeU8((byte)instruction.opcode);
for (int j = 0; j < opcodeInfo.argumentTypes.Length; j++)
{
switch (opcodeInfo.argumentTypes[j])
{
case OpcodeArgumentType.Unknown:
throw new Exception("Don't know how to encode OP_" + opcodeInfo.name);
case OpcodeArgumentType.UByteLiteral:
writeU8(instruction.arguments[j].ubytev);
break;
case OpcodeArgumentType.IntLiteral:
writeS32(instruction.arguments[j].intv);
break;
case OpcodeArgumentType.UIntLiteral:
writeU32(instruction.arguments[j].uintv);
break;
case OpcodeArgumentType.Int:
case OpcodeArgumentType.UInt:
case OpcodeArgumentType.Double:
case OpcodeArgumentType.String:
case OpcodeArgumentType.Namespace:
case OpcodeArgumentType.Multiname:
case OpcodeArgumentType.Class:
case OpcodeArgumentType.Method:
writeU30(instruction.arguments[j].index);
break;
case OpcodeArgumentType.JumpTarget:
fixups.Add(new Fixup(instruction.arguments[j].jumpTarget, pos, pos + 3));
writeS24(0);
break;
case OpcodeArgumentType.SwitchDefaultTarget:
fixups.Add(new Fixup(instruction.arguments[j].jumpTarget, pos, instructionOffset));
writeS24(0);
break;
case OpcodeArgumentType.SwitchTargets:
writeU30((uint)instruction.arguments[j].switchTargets.Length - 1);
foreach (var off in instruction.arguments[j].switchTargets)
{
fixups.Add(new Fixup(off, pos, instructionOffset));
writeS24(0);
}
break;
}
}
}
Array.Resize(ref buf, (int)pos);
instructionOffsets[v.instructions.Length] = pos;
foreach (var fixup in fixups)
{
pos = fixup.pos;
writeS24((int)(resolveLabel(fixup.target) - fixup.baseOffset));
}
byte[] code = buf;
// restore global buffer
buf = globalBuf;
pos = globalPos;
writeBytes(code);
}
writeU30((uint)v.exceptions.Length);
foreach (var val in v.exceptions)
{
var value = val;
value.from.absoluteOffset = resolveLabel(value.from);
value.to.absoluteOffset = resolveLabel(value.to);
value.target.absoluteOffset = resolveLabel(value.target);
writeExceptionInfo(value);
}
writeU30((uint)v.traits.Length);
foreach (var value in v.traits)
{
writeTrait(value);
}
}