private static void PropagatePushOp(Dictionary <ulong, Block> blocks, Block currBlock, int pushOpIndex)
{
OpCodePush pushOp = currBlock.PushOpCodes[pushOpIndex];
Stack <PathBlockState> workQueue = new Stack <PathBlockState>();
HashSet <Block> visited = new HashSet <Block>();
Stack <ulong> branchStack = new Stack <ulong>();
void Push(PathBlockState pbs)
{
// When block is null, this means we are pushing a restore operation.
// Restore operations are used to undo the work done inside a block
// when we return from it, for example it pops addresses pushed by
// SSY/PBK instructions inside the block, and pushes addresses poped
// by SYNC/BRK.
// For blocks, if it's already visited, we just ignore to avoid going
// around in circles and getting stuck here.
if (pbs.Block == null || !visited.Contains(pbs.Block))
{
workQueue.Push(pbs);
}
}
Push(new PathBlockState(currBlock));
while (workQueue.TryPop(out PathBlockState pbs))
{
if (pbs.ReturningFromVisit)
{
pbs.RestoreStackState(branchStack);
continue;
}
Block current = pbs.Block;
// If the block was already processed, we just ignore it, otherwise
// we would push the same child blocks of an already processed block,
// and go around in circles until memory is exhausted.
if (!visited.Add(current))
{
continue;
}
int pushOpsCount = current.PushOpCodes.Count;
if (pushOpsCount != 0)
{
Push(new PathBlockState(branchStack.Count));
for (int index = pushOpIndex; index < pushOpsCount; index++)
{
branchStack.Push(current.PushOpCodes[index].GetAbsoluteAddress());
}
}
pushOpIndex = 0;
if (current.Next != null)
{
Push(new PathBlockState(current.Next));
}
if (current.Branch != null)
{
Push(new PathBlockState(current.Branch));
}
else if (current.GetLastOp() is OpCodeBranchIndir brIndir)
{
// By adding them in descending order (sorted by address), we process the blocks
// in order (of ascending address), since we work with a LIFO.
foreach (Block possibleTarget in brIndir.PossibleTargets.OrderByDescending(x => x.Address))
{
Push(new PathBlockState(possibleTarget));
}
}
else if (current.GetLastOp() is OpCodeBranchPop op)
{
ulong targetAddress = branchStack.Pop();
if (branchStack.Count == 0)
{
branchStack.Push(targetAddress);
op.Targets.Add(pushOp, op.Targets.Count);
pushOp.PopOps.TryAdd(op, Local());
}
else
{
// First we push the target address (this will be used to push the
// address back into the SSY/PBK stack when we return from that block),
// then we push the block itself into the work "queue" (well, it's a stack)
// for processing.
Push(new PathBlockState(targetAddress));
Push(new PathBlockState(blocks[targetAddress]));
}
}
}
}
private static void PropagatePushOp(Dictionary <ulong, Block> blocks, Block currBlock, int pushOpIndex)
{
OpCodePush pushOp = currBlock.PushOpCodes[pushOpIndex];
Stack <PathBlockState> workQueue = new Stack <PathBlockState>();
HashSet <Block> visited = new HashSet <Block>();
Stack <ulong> branchStack = new Stack <ulong>();
void Push(PathBlockState pbs)
{
if (pbs.Block == null || visited.Add(pbs.Block))
{
workQueue.Push(pbs);
}
}
Push(new PathBlockState(currBlock));
while (workQueue.TryPop(out PathBlockState pbs))
{
if (pbs.ReturningFromVisit)
{
pbs.RestoreStackState(branchStack);
continue;
}
Block current = pbs.Block;
int pushOpsCount = current.PushOpCodes.Count;
if (pushOpsCount != 0)
{
Push(new PathBlockState(branchStack.Count));
for (int index = pushOpIndex; index < pushOpsCount; index++)
{
branchStack.Push(current.PushOpCodes[index].GetAbsoluteAddress());
}
}
pushOpIndex = 0;
if (current.Next != null)
{
Push(new PathBlockState(current.Next));
}
if (current.Branch != null)
{
Push(new PathBlockState(current.Branch));
}
else if (current.GetLastOp() is OpCodeBranchIndir brIndir)
{
foreach (Block possibleTarget in brIndir.PossibleTargets)
{
Push(new PathBlockState(possibleTarget));
}
}
else if (current.GetLastOp() is OpCodeBranchPop op)
{
ulong targetAddress = branchStack.Pop();
if (branchStack.Count == 0)
{
branchStack.Push(targetAddress);
op.Targets.Add(pushOp, op.Targets.Count);
pushOp.PopOps.TryAdd(op, Local());
}
else
{
Push(new PathBlockState(targetAddress));
Push(new PathBlockState(blocks[targetAddress]));
}
}
}
}
