private IRInstruction GetTarget(IRBranchInstruction pBranchInstruction)
{
IRInstruction targetInstruction = mILOffsetLookup[pBranchInstruction.TargetILOffset];
if (targetInstruction.Opcode == IROpcode.Branch)
{
IRBranchInstruction targetBranchInstruction = (IRBranchInstruction)targetInstruction;
if (targetBranchInstruction.BranchCondition == IRBranchCondition.Always)
{
targetInstruction = mILOffsetLookup[targetBranchInstruction.TargetILOffset];
targetInstruction = GetTarget(targetBranchInstruction);
}
}
return(targetInstruction);
}
public void FixTargetInstructions()
{
foreach (IRInstruction instruction in mInstructions)
{
switch (instruction.Opcode)
{
case IROpcode.Branch:
{
IRBranchInstruction branchInstruction = (IRBranchInstruction)instruction;
branchInstruction.TargetIRInstruction = GetTarget(branchInstruction);
if (branchInstruction.TargetIRInstruction == null)
{
throw new NullReferenceException();
}
break;
}
case IROpcode.Switch:
{
IRSwitchInstruction switchInstruction = (IRSwitchInstruction)instruction;
switchInstruction.TargetIRInstructions = new IRInstruction[switchInstruction.TargetILOffsets.Length];
for (int index = 0; index < switchInstruction.TargetILOffsets.Length; ++index)
{
switchInstruction.TargetIRInstructions[index] = mILOffsetLookup[switchInstruction.TargetILOffsets[index]];
if (switchInstruction.TargetIRInstructions[index] == null)
{
throw new NullReferenceException();
}
}
break;
}
case IROpcode.Leave:
{
IRLeaveInstruction leaveInstruction = (IRLeaveInstruction)instruction;
leaveInstruction.TargetIRInstruction = mILOffsetLookup[leaveInstruction.TargetILOffset];
if (leaveInstruction.TargetIRInstruction == null)
{
throw new NullReferenceException();
}
break;
}
default: break;
}
}
}
public static IRControlFlowGraph Build(IRMethod pMethod)
{
if (pMethod.Instructions.Count == 0)
{
return(null);
}
HashSet <IRInstruction> sourceNodeBreaks = new HashSet <IRInstruction>();
HashSet <IRInstruction> destinationNodeBreaks = new HashSet <IRInstruction>();
foreach (IRInstruction instruction in pMethod.Instructions)
{
switch (instruction.Opcode)
{
case IROpcode.Branch:
{
IRBranchInstruction branchInstruction = (IRBranchInstruction)instruction;
if (!sourceNodeBreaks.Contains(instruction))
{
sourceNodeBreaks.Add(instruction);
}
if (!destinationNodeBreaks.Contains(branchInstruction.TargetIRInstruction))
{
destinationNodeBreaks.Add(branchInstruction.TargetIRInstruction);
}
break;
}
case IROpcode.Switch:
{
IRSwitchInstruction switchInstruction = (IRSwitchInstruction)instruction;
if (!sourceNodeBreaks.Contains(instruction))
{
sourceNodeBreaks.Add(instruction);
}
foreach (IRInstruction targetIRInstruction in switchInstruction.TargetIRInstructions)
{
if (!destinationNodeBreaks.Contains(targetIRInstruction))
{
destinationNodeBreaks.Add(targetIRInstruction);
}
}
break;
}
case IROpcode.Leave:
{
IRLeaveInstruction leaveInstruction = (IRLeaveInstruction)instruction;
if (!sourceNodeBreaks.Contains(instruction))
{
sourceNodeBreaks.Add(instruction);
}
if (!destinationNodeBreaks.Contains(leaveInstruction.TargetIRInstruction))
{
destinationNodeBreaks.Add(leaveInstruction.TargetIRInstruction);
}
break;
}
default: break;
}
}
IRControlFlowGraph cfg = new IRControlFlowGraph();
Node currentNode = new Node(0);
cfg.Nodes.Add(currentNode);
foreach (IRInstruction instruction in pMethod.Instructions)
{
bool lastInstruction = instruction == pMethod.Instructions[pMethod.Instructions.Count - 1];
bool startFromSource = sourceNodeBreaks.Contains(instruction);
bool startFromDestination = destinationNodeBreaks.Contains(instruction);
if (startFromSource && startFromDestination)
{
if (currentNode.Instructions.Count > 0)
{
currentNode = new Node((uint)cfg.Nodes.Count);
cfg.Nodes.Add(currentNode);
}
currentNode.Instructions.Add(instruction);
currentNode = new Node((uint)cfg.Nodes.Count);
cfg.Nodes.Add(currentNode);
}
else if (startFromSource)
{
currentNode.Instructions.Add(instruction);
currentNode = new Node((uint)cfg.Nodes.Count);
cfg.Nodes.Add(currentNode);
}
else if (startFromDestination)
{
if (currentNode.Instructions.Count > 0)
{
currentNode = new Node((uint)cfg.Nodes.Count);
cfg.Nodes.Add(currentNode);
}
currentNode.Instructions.Add(instruction);
}
else
{
currentNode.Instructions.Add(instruction);
}
}
for (int nodeIndex = 0; nodeIndex < cfg.Nodes.Count; ++nodeIndex)
{
Node node = cfg.Nodes[nodeIndex];
IRInstruction instruction = node.Instructions[node.Instructions.Count - 1];
switch (instruction.Opcode)
{
case IROpcode.Branch:
{
IRBranchInstruction branchInstruction = (IRBranchInstruction)instruction;
Node childNode = cfg.Nodes.Find(n => n.Instructions[0] == branchInstruction.TargetIRInstruction);
if (childNode == null)
{
throw new NullReferenceException();
}
if (branchInstruction.BranchCondition != IRBranchCondition.Always)
{
node.LinkTo(cfg.Nodes[nodeIndex + 1]);
}
node.LinkTo(childNode);
break;
}
case IROpcode.Switch:
{
IRSwitchInstruction switchInstruction = (IRSwitchInstruction)instruction;
node.LinkTo(cfg.Nodes[nodeIndex + 1]);
foreach (IRInstruction targetInstruction in switchInstruction.TargetIRInstructions)
{
Node childNode = cfg.Nodes.Find(n => n.Instructions[0] == targetInstruction);
if (childNode == null)
{
throw new NullReferenceException();
}
node.LinkTo(childNode);
}
break;
}
case IROpcode.Leave:
{
IRLeaveInstruction leaveInstruction = (IRLeaveInstruction)instruction;
Node childNode = cfg.Nodes.Find(n => n.Instructions[0] == leaveInstruction.TargetIRInstruction);
if (childNode == null)
{
throw new NullReferenceException();
}
node.LinkTo(childNode);
break;
}
case IROpcode.Throw:
case IROpcode.Return: continue;
default: node.LinkTo(cfg.Nodes[nodeIndex + 1]); break;
}
}
return(cfg);
}
public IRInstruction this[int pIndex]
{
get
{
if (pIndex < 0)
{
throw new IndexOutOfRangeException("An IRInstruction index cannot be less than 0!");
}
if (pIndex >= mInstructions.Count)
{
throw new IndexOutOfRangeException("The requested IRInstruction doesn't exist!");
}
return(mInstructions[pIndex]);
}
set
{
if (pIndex < 0)
{
throw new IndexOutOfRangeException("An IRInstruction index cannot be less than 0!");
}
if (pIndex >= mInstructions.Count)
{
throw new IndexOutOfRangeException("The specified IRInstruction doesn't exist!");
}
if (mInstructions[pIndex] != value)
{
if (!value.Resolved)
{
mResolvedCache = false;
}
IRInstruction oldInstruction = mInstructions[pIndex];
IRInstruction newInstruction = value;
mInstructions[pIndex] = value;
mILOffsetLookup[newInstruction.ILOffset] = newInstruction;
foreach (IRInstruction instruction in mInstructions)
{
switch (instruction.Opcode)
{
case IROpcode.Branch:
{
IRBranchInstruction branchInstruction = (IRBranchInstruction)instruction;
if (branchInstruction.TargetIRInstruction == oldInstruction)
{
branchInstruction.TargetIRInstruction = newInstruction;
}
break;
}
case IROpcode.Switch:
{
IRSwitchInstruction switchInstruction = (IRSwitchInstruction)instruction;
for (int index = 0; index < switchInstruction.TargetIRInstructions.Length; ++index)
{
if (switchInstruction.TargetIRInstructions[index] == oldInstruction)
{
switchInstruction.TargetIRInstructions[index] = newInstruction;
}
}
break;
}
case IROpcode.Leave:
{
IRLeaveInstruction leaveInstruction = (IRLeaveInstruction)instruction;
if (leaveInstruction.TargetIRInstruction == oldInstruction)
{
leaveInstruction.TargetIRInstruction = newInstruction;
}
break;
}
default: break;
}
}
}
}
}
private void LinearizePath(MethodDefData pMethodDefData, IRInstruction pStartInstruction, Stack <IRStackObject> pStack, Queue <Tuple <IRInstruction, Stack <IRStackObject> > > pBranches)
{
int stackReturn = pStack.Count;
IRInstruction currentInstruction = pStartInstruction;
MethodDefData.MethodDefBodyData.MethodDefBodyExceptionData exceptionData = null;
while (currentInstruction != null)
{
if (currentInstruction.Linearized && pStack.Count == stackReturn)
{
break;
}
if ((exceptionData = Array.Find(pMethodDefData.Body.Exceptions, e => e.Flags == 0 && e.HandlerOffset == currentInstruction.ILOffset)) != null)
{
IRType exceptionType = Assembly.AppDomain.PresolveType(Assembly.File.ExpandMetadataToken(exceptionData.ClassTokenOrFilterOffset));
IRStackObject exceptionObj = new IRStackObject();
exceptionObj.Type = exceptionType;
exceptionObj.LinearizedTarget = new IRLinearizedLocation(IRLinearizedLocationType.Local);
exceptionObj.LinearizedTarget.Local.LocalIndex = currentInstruction.AddLinearizedLocal(pStack, exceptionType);
pStack.Push(exceptionObj);
}
currentInstruction.Linearize(pStack);
currentInstruction.Linearized = true;
switch (currentInstruction.Opcode)
{
case IROpcode.Branch:
{
IRBranchInstruction branchInstruction = (IRBranchInstruction)currentInstruction;
if (branchInstruction.BranchCondition == IRBranchCondition.Always)
{
currentInstruction = branchInstruction.TargetIRInstruction;
}
else
{
pBranches.Enqueue(new Tuple <IRInstruction, Stack <IRStackObject> >(branchInstruction.TargetIRInstruction, pStack.Duplicate()));
currentInstruction = Instructions[currentInstruction.IRIndex + 1];
}
break;
}
case IROpcode.Switch:
{
IRSwitchInstruction switchInstruction = (IRSwitchInstruction)currentInstruction;
foreach (IRInstruction targetInstruction in switchInstruction.TargetIRInstructions)
{
pBranches.Enqueue(new Tuple <IRInstruction, Stack <IRStackObject> >(targetInstruction, pStack.Duplicate()));
}
currentInstruction = Instructions[currentInstruction.IRIndex + 1];
break;
}
case IROpcode.Leave:
{
IRLeaveInstruction leaveInstruction = (IRLeaveInstruction)currentInstruction;
currentInstruction = leaveInstruction.TargetIRInstruction;
break;
}
case IROpcode.Jump:
case IROpcode.Throw:
case IROpcode.Return: currentInstruction = null; break;
default: currentInstruction = currentInstruction.IRIndex >= Instructions.Count ? null : Instructions[currentInstruction.IRIndex + 1]; break;
}
}
}