/// <summary>
/// Retrieves all possible successors of a given instruction
/// </summary>
/// <typeparam name="Ti">data type representing an instruction</typeparam>
/// <param name="ii">instruction information service</param>
/// <param name="i">an instruction</param>
/// <returns>all possible successors in terms of their instruction indices</returns>
public static IEnumerable <int> GetSuccessors <Ti>(this IInstructionInfo <Ti> ii, Ti i)
where Ti : IInstruction
{
IEnumerable <int> targets;
IEnumerable <int> foll = Enumerable.Repeat(i.Index, 1);
switch (ii.IsBranch(i, out targets))
{
case EBranchBehavior.CBranch:
case EBranchBehavior.Switch:
return(targets.Concat(foll));
case EBranchBehavior.NoBranch:
return(foll);
case EBranchBehavior.Return:
case EBranchBehavior.Throw:
return(Enumerable.Empty <int>());
case EBranchBehavior.UBranch:
return(targets);
default:
throw new NotImplementedException();
}
}
/// <summary>
/// Constructs a new instance based on an instruction sequence
/// </summary>
/// <param name="instructions">instruction sequence</param>
/// <param name="marshal">the instruction which should be treated as exit point</param>
/// <param name="iinfo">instruction information service</param>
/// <param name="entryPoint">optional entry point for graph construction (as instruction index)</param>
/// <param name="exitPoints">optional set of additional exit points (as instruction indices)</param>
public ControlFlowGraph(IEnumerable <Ti> instructions, Ti marshal, IInstructionInfo <Ti> iinfo, int entryPoint = 0, ISet <int> exitPoints = null)
{
InstructionInfo = iinfo;
Instructions = new List <Ti>(instructions);
Instructions.Add(marshal);
int numInstrs = Instructions.Count;
_marshal = marshal;
_entryPoint = entryPoint;
_exitPoints = exitPoints;
_branches = new bool[numInstrs];
_branchTargets = new bool[numInstrs];
_successors = new Ti[numInstrs][];
_successors[numInstrs - 1] = new Ti[0];
_predecessors = new Ti[numInstrs][];
Setup();
}
