public bool AddGuess(MetaValueGuess guess)
{
// Don't overwrite good guesses with null pointers
if (_guesses.ContainsKey(guess.Offset))
{
if (guess.Pointer == 0 || guess.Pointer == 0xFFFFFFFF || guess.Pointer == 0xCDCDCDCD)
return false;
}
/*if (_submaps.ContainsKey(guess.Offset))
return;*/
// Just store it
_guesses[guess.Offset] = guess;
return true;
}
public void AnalyzeArea(IReader reader, uint startAddress, MetaMap resultMap)
{
// Right now, this method only searches for the signatures of a few complex meta values.
// Reflexives: int32 entry count + uint32 address + 4 bytes of padding
// Data references: int32 size + 8 bytes of padding + uint32 address
// Tag references: int32 class id + 8 bytes of padding + uint32 datum index
// ASCII strings: characters with the values 0 or 0x20 - 0x7F
// End at the next-highest address
uint endAddress = _memMap.GetNextHighestAddress(startAddress);
if (endAddress == 0xFFFFFFFF)
throw new InvalidOperationException("Invalid start address for area analysis");
uint size = endAddress - startAddress; // The size of the block of data
int paddingLength = 0; // The number of 4-byte padding values that have been read
uint prePadding = 0; // The last non-padding uint32 that was read
MetaValueGuess pendingGuess = null; // If not null and padding is encountered, this guess is confirmed
for (int offset = 0; offset < size; offset += 4)
{
uint value = reader.ReadUInt32();
if (IsPadding(value))
{
if (paddingLength == 0 && pendingGuess != null)
{
resultMap.AddGuess(pendingGuess);
// Add the address to the memory map
uint address = pendingGuess.Pointer;
_memMap.AddAddress(address, (int)reader.Position);
}
// More padding! :D
paddingLength++;
pendingGuess = null;
}
else
{
pendingGuess = null;
if (offset <= size - 8
&& prePadding > 0
&& prePadding < 0x80000000
&& (value & 3) == 0
&& IsValidAddress(value)
&& (uint)(value + prePadding) > value
&& IsValidAddress(value + prePadding - 1)
&& !_memMap.BlockCrossesBoundary(value, (int)prePadding))
{
// Either a reflexive or a data reference
// Check the padding to determine which (see the comments at the beginning of this method)
if (paddingLength == 2 && offset >= 12 && (prePadding & 3) == 0)
{
// Found a data reference
uint dataSize = prePadding;
uint address = value;
pendingGuess = new MetaValueGuess(offset - 12, MetaValueType.DataReference, address, dataSize); // Guess with Pointer = address, Data1 = data size
}
else if (paddingLength == 0 && offset >= 4)
{
// Found a reflexive!
uint entryCount = prePadding;
uint address = value;
pendingGuess = new MetaValueGuess(offset - 4, MetaValueType.Reflexive, address, entryCount); // Guess with Pointer = address, Data1 = entry count
}
}
if (paddingLength == 2 && offset >= 12 && (_classIds.Contains((int)prePadding) || (prePadding == 0xFFFFFFFF && value == 0xFFFFFFFF)))
{
// Found a tag reference
uint classId = prePadding;
uint datumIndex = value;
MetaValueGuess guess = new MetaValueGuess(offset - 12, MetaValueType.TagReference, datumIndex, classId); // Guess with Pointer = datum index, Data1 = class id
resultMap.AddGuess(guess);
}
// This obviously isn't a padding value because IsPadding returned false,
// so update padding run information accordingly
prePadding = value;
paddingLength = 0;
}
}
}
