private static short[] FindStartInstructions(InstructionSequence seq)
{
int len = seq.Length();
short[] inststates = new short[len];
HashSet <int> excSet = new HashSet <int>();
foreach (ExceptionHandler handler in seq.GetExceptionTable().GetHandlers())
{
excSet.Add(handler.from_instr);
excSet.Add(handler.to_instr);
excSet.Add(handler.handler_instr);
}
for (int i = 0; i < len; i++)
{
// exception blocks
if (excSet.Contains(i))
{
inststates[i] = 1;
}
Instruction instr = seq.GetInstr(i);
switch (instr.group)
{
case Group_Jump:
{
inststates[((JumpInstruction)instr).destination] = 1;
goto case Group_Return;
}
case Group_Return:
{
if (i + 1 < len)
{
inststates[i + 1] = 1;
}
break;
}
case Group_Switch:
{
SwitchInstruction swinstr = (SwitchInstruction)instr;
int[] dests = swinstr.GetDestinations();
for (int j = dests.Length - 1; j >= 0; j--)
{
inststates[dests[j]] = 1;
}
inststates[swinstr.GetDefaultDestination()] = 1;
if (i + 1 < len)
{
inststates[i + 1] = 1;
}
break;
}
}
}
// first instruction
inststates[0] = 1;
return(inststates);
}
private static void ConnectBlocks(List <BasicBlock> lstbb, Dictionary <int, BasicBlock
> mapInstrBlocks)
{
for (int i = 0; i < lstbb.Count; i++)
{
BasicBlock block = lstbb[i];
Instruction instr = block.GetLastInstruction();
bool fallthrough = instr.CanFallThrough();
BasicBlock bTemp;
switch (instr.group)
{
case Group_Jump:
{
int dest = ((JumpInstruction)instr).destination;
bTemp = mapInstrBlocks.GetOrNull(dest);
block.AddSuccessor(bTemp);
break;
}
case Group_Switch:
{
SwitchInstruction sinstr = (SwitchInstruction)instr;
int[] dests = sinstr.GetDestinations();
bTemp = mapInstrBlocks.GetOrNull(((SwitchInstruction)instr).GetDefaultDestination
());
block.AddSuccessor(bTemp);
foreach (int dest1 in dests)
{
bTemp = mapInstrBlocks.GetOrNull(dest1);
block.AddSuccessor(bTemp);
}
break;
}
}
if (fallthrough && i < lstbb.Count - 1)
{
BasicBlock defaultBlock = lstbb[i + 1];
block.AddSuccessor(defaultBlock);
}
}
}
