private static void DeleteArea(ControlFlowGraph graph, FinallyProcessor.Area area
)
{
BasicBlock start = area.start;
BasicBlock next = area.next;
if (start == next)
{
return;
}
if (next == null)
{
// dummy exit block
next = graph.GetLast();
}
// collect common exception ranges of predecessors and successors
HashSet <BasicBlock> setCommonExceptionHandlers = new HashSet <BasicBlock>(next.GetSuccExceptions
());
foreach (BasicBlock pred in start.GetPreds())
{
setCommonExceptionHandlers.RetainAll(pred.GetSuccExceptions());
}
bool is_outside_range = false;
HashSet <BasicBlock> setPredecessors = new HashSet <BasicBlock>(start.GetPreds());
// replace start with next
foreach (BasicBlock pred in setPredecessors)
{
pred.ReplaceSuccessor(start, next);
}
HashSet <BasicBlock> setBlocks = area.sample;
HashSet <ExceptionRangeCFG> setCommonRemovedExceptionRanges = null;
// remove all the blocks inbetween
foreach (BasicBlock block in setBlocks)
{
// artificial basic blocks (those resulted from splitting)
// can belong to more than one area
if (graph.GetBlocks().ContainsKey(block.id))
{
if (!block.GetSuccExceptions().ContainsAll(setCommonExceptionHandlers))
{
is_outside_range = true;
}
HashSet <ExceptionRangeCFG> setRemovedExceptionRanges = new HashSet <ExceptionRangeCFG
>();
foreach (BasicBlock handler in block.GetSuccExceptions())
{
setRemovedExceptionRanges.Add(graph.GetExceptionRange(handler, block));
}
if (setCommonRemovedExceptionRanges == null)
{
setCommonRemovedExceptionRanges = setRemovedExceptionRanges;
}
else
{
setCommonRemovedExceptionRanges.RetainAll(setRemovedExceptionRanges);
}
// shift extern edges on splitted blocks
if (block.GetSeq().IsEmpty() && block.GetSuccs().Count == 1)
{
BasicBlock succs = block.GetSuccs()[0];
foreach (BasicBlock pred in new List <BasicBlock>(block.GetPreds()))
{
if (!setBlocks.Contains(pred))
{
pred.ReplaceSuccessor(block, succs);
}
}
if (graph.GetFirst() == block)
{
graph.SetFirst(succs);
}
}
graph.RemoveBlock(block);
}
}
if (is_outside_range)
{
// new empty block
BasicBlock emptyblock = new BasicBlock(++graph.last_id);
graph.GetBlocks().AddWithKey(emptyblock, emptyblock.id);
// add to ranges if necessary
foreach (ExceptionRangeCFG range in setCommonRemovedExceptionRanges)
{
emptyblock.AddSuccessorException(range.GetHandler());
range.GetProtectedRange().Add(emptyblock);
}
// insert between predecessors and next
emptyblock.AddSuccessor(next);
foreach (BasicBlock pred in setPredecessors)
{
pred.ReplaceSuccessor(next, emptyblock);
}
}
}
private bool VerifyFinallyEx(ControlFlowGraph graph, CatchAllStatement fstat, FinallyProcessor.Record
information)
{
HashSet <BasicBlock> tryBlocks = GetAllBasicBlocks(fstat.GetFirst());
HashSet <BasicBlock> catchBlocks = GetAllBasicBlocks(fstat.GetHandler());
int finallytype = information.firstCode;
Dictionary <BasicBlock, bool> mapLast = information.mapLast;
BasicBlock first = fstat.GetHandler().GetBasichead().GetBlock();
bool skippedFirst = false;
if (finallytype == 3)
{
// empty finally
RemoveExceptionInstructionsEx(first, 3, finallytype);
if (mapLast.ContainsKey(first))
{
graph.GetFinallyExits().Add(first);
}
return(true);
}
else if (first.GetSeq().Length() == 1 && finallytype > 0)
{
BasicBlock firstsuc = first.GetSuccs()[0];
if (catchBlocks.Contains(firstsuc))
{
first = firstsuc;
skippedFirst = true;
}
}
// identify start blocks
HashSet <BasicBlock> startBlocks = new HashSet <BasicBlock>();
foreach (BasicBlock block in tryBlocks)
{
Sharpen.Collections.AddAll(startBlocks, block.GetSuccs());
}
// throw in the try body will point directly to the dummy exit
// so remove dummy exit
startBlocks.Remove(graph.GetLast());
startBlocks.RemoveAll(tryBlocks);
List <FinallyProcessor.Area> lstAreas = new List <FinallyProcessor.Area>();
foreach (BasicBlock start in startBlocks)
{
FinallyProcessor.Area arr = CompareSubgraphsEx(graph, start, catchBlocks, first,
finallytype, mapLast, skippedFirst);
if (arr == null)
{
return(false);
}
lstAreas.Add(arr);
}
// try {
// DotExporter.toDotFile(graph, new File("c:\\Temp\\fern5.dot"), true);
// } catch(Exception ex){ex.printStackTrace();}
// delete areas
foreach (FinallyProcessor.Area area in lstAreas)
{
DeleteArea(graph, area);
}
// try {
// DotExporter.toDotFile(graph, new File("c:\\Temp\\fern5.dot"), true);
// } catch(Exception ex){ex.printStackTrace();}
// INFO: empty basic blocks may remain in the graph!
foreach (KeyValuePair <BasicBlock, bool> entry in mapLast)
{
BasicBlock last = entry.Key;
if (entry.Value)
{
RemoveExceptionInstructionsEx(last, 2, finallytype);
graph.GetFinallyExits().Add(last);
}
}
RemoveExceptionInstructionsEx(fstat.GetHandler().GetBasichead().GetBlock(), 1, finallytype
);
return(true);
}