private void WriteStructureFooter(ILStructure s)
{
_output.Unindent();
switch (s.Type)
{
case ILStructureType.Loop:
_output.WriteLine("// end loop");
break;
case ILStructureType.Try:
_output.WriteLine("} // end .try");
break;
case ILStructureType.Handler:
_output.WriteLine("} // end handler");
break;
case ILStructureType.Filter:
_output.WriteLine("} // end filter");
break;
default:
throw new NotSupportedException();
}
}
private void WriteStructureHeader(ILStructure s)
{
switch (s.Type)
{
case ILStructureType.Loop:
_output.Write("// loop start");
if (s.LoopEntryPoint != null)
{
_output.Write(" (head: ");
DisassemblerHelpers.WriteOffsetReference(_output, s.LoopEntryPoint);
_output.Write(')');
}
_output.WriteLine();
break;
case ILStructureType.Try:
_output.WriteLine(".try");
_output.WriteLine("{");
break;
case ILStructureType.Handler:
switch (s.ExceptionHandler?.HandlerType)
{
case ExceptionHandlerType.Catch:
case ExceptionHandlerType.Filter:
_output.Write("catch");
if (s.ExceptionHandler?.CatchType != null)
{
_output.Write(' ');
s.ExceptionHandler.CatchType.WriteTo(_output, ILNameSyntax.TypeName);
}
_output.WriteLine();
break;
case ExceptionHandlerType.Finally:
_output.WriteLine("finally");
break;
case ExceptionHandlerType.Fault:
_output.WriteLine("fault");
break;
default:
throw new NotSupportedException();
}
_output.WriteLine("{");
break;
case ILStructureType.Filter:
_output.WriteLine("filter");
_output.WriteLine("{");
break;
default:
throw new NotSupportedException();
}
_output.Indent();
}
bool AddNestedStructure(ILStructure newStructure)
{
// special case: don't consider the loop-like structure of "continue;" statements to be nested loops
if (Type == ILStructureType.Loop && newStructure.Type == ILStructureType.Loop && newStructure.StartOffset == StartOffset)
{
return(false);
}
// use <= for end-offset comparisons because both end and EndOffset are exclusive
Debug.Assert(StartOffset <= newStructure.StartOffset && newStructure.EndOffset <= EndOffset);
foreach (var child in Children)
{
if (child.StartOffset <= newStructure.StartOffset && newStructure.EndOffset <= child.EndOffset)
{
return(child.AddNestedStructure(newStructure));
}
if (!(child.EndOffset <= newStructure.StartOffset || newStructure.EndOffset <= child.StartOffset))
{
// child and newStructure overlap
if (!(newStructure.StartOffset <= child.StartOffset && child.EndOffset <= newStructure.EndOffset))
{
// Invalid nesting, can't build a tree. -> Don't add the new structure.
return(false);
}
}
}
// Move existing structures into the new structure:
for (var i = 0; i < Children.Count; i++)
{
var child = Children[i];
if (newStructure.StartOffset <= child.StartOffset && child.EndOffset <= newStructure.EndOffset)
{
Children.RemoveAt(i--);
newStructure.Children.Add(child);
}
}
// Add the structure here:
Children.Add(newStructure);
return(true);
}
private void WriteStructureBody(ILStructure s, HashSet <int> branchTargets, ref Instruction inst)
{
var isFirstInstructionInStructure = true;
var prevInstructionWasBranch = false;
var childIndex = 0;
while (inst != null && inst.Offset < s.EndOffset)
{
var offset = inst.Offset;
if (childIndex < s.Children.Count && s.Children[childIndex].StartOffset <= offset && offset < s.Children[childIndex].EndOffset)
{
var child = s.Children[childIndex++];
WriteStructureHeader(child);
WriteStructureBody(child, branchTargets, ref inst);
WriteStructureFooter(child);
}
else
{
if (!isFirstInstructionInStructure && (prevInstructionWasBranch || branchTargets.Contains(offset)))
{
_output.WriteLine(); // put an empty line after branches, and in front of branch targets
}
inst.WriteTo(_output);
_output.WriteLine();
prevInstructionWasBranch = inst.OpCode.FlowControl == FlowControl.Branch ||
inst.OpCode.FlowControl == FlowControl.Cond_Branch ||
inst.OpCode.FlowControl == FlowControl.Return ||
inst.OpCode.FlowControl == FlowControl.Throw;
inst = inst.Next;
}
isFirstInstructionInStructure = false;
}
}