private void BuildTryBody(YieldExceptionHandlerInfo handlerInfo)
{
this.newTryBody = new HashSet <ILogicalConstruct>();
dummyVar0 = this.newTryBody.Add(this.entryOfTry);
this.newFinallyBody = null;
V_0 = new HashSet <ILogicalConstruct>();
V_1 = new Queue <ILogicalConstruct>();
V_2 = this.entryOfTry.get_SameParentSuccessors().GetEnumerator();
try
{
while (V_2.MoveNext())
{
V_3 = (ILogicalConstruct)V_2.get_Current();
V_1.Enqueue(V_3);
}
}
finally
{
((IDisposable)V_2).Dispose();
}
while (V_1.get_Count() > 0)
{
V_4 = V_1.Dequeue();
if (!V_0.Add(V_4) || this.finallyBlocks.Contains(V_4))
{
continue;
}
this.ProcessCurrentNode(handlerInfo, V_1, V_4);
}
return;
}
private void MapBlocks()
{
V_0 = this.logicalBuilderContext.get_CFG().get_Blocks();
V_1 = 0;
while (V_1 < (int)V_0.Length)
{
V_2 = V_0[V_1];
V_3 = V_2.get_First().get_Offset();
stackVariable17 = this.logicalBuilderContext.get_CFGBlockToLogicalConstructMap();
stackVariable20 = new CFGBlockLogicalConstruct[1];
stackVariable20[0] = new CFGBlockLogicalConstruct(V_2, this.methodContext.get_Expressions().get_BlockExpressions().get_Item(V_3));
stackVariable17.Add(V_2, stackVariable20);
V_1 = V_1 + 1;
}
V_0 = this.logicalBuilderContext.get_CFG().get_Blocks();
V_1 = 0;
while (V_1 < (int)V_0.Length)
{
V_4 = V_0[V_1];
V_5 = this.logicalBuilderContext.get_CFGBlockToLogicalConstructMap().get_Item(V_4)[0];
V_6 = V_4.get_Successors();
V_7 = 0;
while (V_7 < (int)V_6.Length)
{
V_8 = V_6[V_7];
V_9 = this.logicalBuilderContext.get_CFGBlockToLogicalConstructMap().get_Item(V_8)[0];
V_5.AddToSuccessors(V_9);
V_9.AddToPredecessors(V_5);
V_7 = V_7 + 1;
}
V_1 = V_1 + 1;
}
return;
}
/// <summary>
/// Generates the try/finally construct that is represented by the specifed exception handler info and attaches it to the logical tree.
/// </summary>
/// <param name="handlerInfo"></param>
private void GenerateTryFinallyHandler(YieldExceptionHandlerInfo handlerInfo)
{
finallyBlocks = new HashSet <ILogicalConstruct>();
entryOfTry = GetStateBeginBlockConstruct(handlerInfo.TryStates);
BuildTryBody(handlerInfo);
BlockLogicalConstruct newFinally;
if (handlerInfo.HandlerType == YieldExceptionHandlerType.Method)
{
if (newFinallyBody == null)
{
throw new Exception("Could not determine the end ot the try block");
}
RemoveExcessNodesFromTheTryBlock();
ProcessFinallyNodes();
newFinally = new BlockLogicalConstruct(newFinallyBody, new ILogicalConstruct[] { newFinallyBody });
}
else
{
newFinally = GenerateFinallyBlock();
}
BlockLogicalConstruct newTry = new BlockLogicalConstruct(entryOfTry, newTryBody);
TryFinallyLogicalConstruct newTryFinallyConstruct = new TryFinallyLogicalConstruct(newTry, newFinally);
createdConstructsToIntervalMap[newTryFinallyConstruct] = handlerInfo;
CleanUpOrderedNodes(newTryFinallyConstruct);
}
/// <summary>
/// Builds the try body of the specified exception handler starting from the given entry node.
/// </summary>
/// <remarks>
/// We assume that all nodes before reaching the finally block are in the try construct.
/// </remarks>
/// <param name="handlerInfo"></param>
/// <param name="entryOfTry"></param>
private void BuildTryBody(YieldExceptionHandlerInfo handlerInfo)
{
newTryBody = new HashSet <ILogicalConstruct>();
newTryBody.Add(entryOfTry);
newFinallyBody = null;
HashSet <ILogicalConstruct> traversedNodes = new HashSet <ILogicalConstruct>();
Queue <ILogicalConstruct> bfsQueue = new Queue <ILogicalConstruct>();
foreach (ILogicalConstruct successor in entryOfTry.SameParentSuccessors)
{
bfsQueue.Enqueue(successor);
}
while (bfsQueue.Count > 0)
{
ILogicalConstruct currentNode = bfsQueue.Dequeue();
if (!traversedNodes.Add(currentNode) || finallyBlocks.Contains(currentNode))
{
continue;
}
ProcessCurrentNode(handlerInfo, bfsQueue, currentNode);
}
}
private void ProcessMultiWayCFGPredecessor(CFGBlockLogicalConstruct finallyBody, InstructionBlock theBlock, InstructionBlock theNewSuccessor)
{
V_0 = finallyBody.get_TheBlock();
V_2 = 0;
while (V_2 < (int)theBlock.get_Successors().Length)
{
if (InstructionBlock.op_Equality(theBlock.get_Successors()[V_2], V_0))
{
theBlock.get_Successors()[V_2] = theNewSuccessor;
}
V_2 = V_2 + 1;
}
if (this.methodContext.get_ControlFlowGraph().get_SwitchBlocksInformation().TryGetValue(theBlock, out V_1))
{
V_3 = V_1.get_OrderedCasesArray();
V_4 = 0;
while (V_4 < (int)V_3.Length)
{
if (InstructionBlock.op_Equality(V_3[V_4], V_0))
{
V_3[V_4] = theNewSuccessor;
}
V_4 = V_4 + 1;
}
if (InstructionBlock.op_Equality(V_1.get_DefaultCase(), V_0))
{
V_1.set_DefaultCase(theNewSuccessor);
}
}
return;
}
/// <summary>
/// Gets the first found entry CFGBlockLogicalConstruct for a state from the tryStates.
/// </summary>
/// <remarks>
/// We try to get the first CFGBlockLC, that is going to be reached by the control flow, in which the state field is assigned to a state of the
/// <paramref name="tryStates"/>. If the assignment is not at the begining of the CFGConstruct then we need to split it, since the try begins
/// at the assignment.
/// </remarks>
/// <param name="tryStates"></param>
/// <returns></returns>
private CFGBlockLogicalConstruct GetStateBeginBlockConstruct(HashSet <int> tryStates)
{
for (int i = 0; i < this.orderedCFGNodes.Count; i++)
{
CFGBlockLogicalConstruct currentCFGConstruct = this.orderedCFGNodes[i];
List <Expression> blockExpressions = currentCFGConstruct.LogicalConstructExpressions;
for (int j = 0; j < blockExpressions.Count; j++)
{
int value;
if (TryGetStateAssignValue(blockExpressions[j], out value) && tryStates.Contains(value))
{
if (j != 0)
{
KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct> newCFGConstructsPair =
LogicalFlowUtilities.SplitCFGBlockAt(this.logicalContext, currentCFGConstruct, j);
this.orderedCFGNodes[i] = newCFGConstructsPair.Key;
this.orderedCFGNodes.Insert(i + 1, newCFGConstructsPair.Value);
return(newCFGConstructsPair.Value);
}
else
{
return(currentCFGConstruct);
}
}
}
}
throw new Exception("Invalid state value");
}
private void GenerateTryFinallyHandler(YieldExceptionHandlerInfo handlerInfo)
{
this.finallyBlocks = new HashSet <ILogicalConstruct>();
this.entryOfTry = this.GetStateBeginBlockConstruct(handlerInfo.get_TryStates());
this.BuildTryBody(handlerInfo);
if (handlerInfo.get_HandlerType() != YieldExceptionHandlerType.Method)
{
V_0 = this.GenerateFinallyBlock();
}
else
{
if (this.newFinallyBody == null)
{
throw new Exception("Could not determine the end ot the try block");
}
this.RemoveExcessNodesFromTheTryBlock();
this.ProcessFinallyNodes();
stackVariable31 = this.newFinallyBody;
stackVariable33 = new ILogicalConstruct[1];
stackVariable33[0] = this.newFinallyBody;
V_0 = new BlockLogicalConstruct(stackVariable31, stackVariable33);
}
V_1 = new TryFinallyLogicalConstruct(new BlockLogicalConstruct(this.entryOfTry, this.newTryBody), V_0);
this.createdConstructsToIntervalMap.set_Item(V_1, handlerInfo);
this.CleanUpOrderedNodes(V_1);
return;
}
/// <summary>
/// Changes the successors of the given instruction block to reflect the changes in the logical tree.
/// </summary>
/// <remarks>
/// Also modifies switch data.
/// Done because later substeps of the LogicalFlowBuilderStep depend on the successor information of the CFG
/// (e.g. Determining the true and false successors of a ConditionLogicalConstruct, determining the cases of a switch/NWayConditional construct).
/// </remarks>
/// <param name="theCFGConstruct"></param>
/// <param name="theCFGSuccessor"></param>
private void ProcessMultiWayCFGPredecessor(CFGBlockLogicalConstruct finallyBody, InstructionBlock theBlock, InstructionBlock theNewSuccessor)
{
InstructionBlock theFinallyBlock = finallyBody.TheBlock;
for (int i = 0; i < theBlock.Successors.Length; i++)
{
if (theBlock.Successors[i] == theFinallyBlock)
{
theBlock.Successors[i] = theNewSuccessor;
}
}
SwitchData switchData;
if (methodContext.ControlFlowGraph.SwitchBlocksInformation.TryGetValue(theBlock, out switchData))
{
InstructionBlock[] theConditionCases = switchData.OrderedCasesArray;
for (int i = 0; i < theConditionCases.Length; i++)
{
if (theConditionCases[i] == theFinallyBlock)
{
theConditionCases[i] = theNewSuccessor;
}
}
if (switchData.DefaultCase == theFinallyBlock)
{
switchData.DefaultCase = theNewSuccessor;
}
}
}
/// <summary>
/// Generates the finally block.
/// </summary>
/// <remarks>
/// Since the condition block and the dispose invocation block should have a common successor, a new EmptyBlockLogicalConstruct
/// is added to the logical tree.
/// </remarks>
/// <returns></returns>
private BlockLogicalConstruct GenerateFinallyBlock()
{
CFGBlockLogicalConstruct finallySuccessor = ProcessFinallyNode(finallyEntryBlock, disposeCallBlock);
finallySuccessor.RemoveFromPredecessors(conditionBlock);
conditionBlock.RemoveFromSuccessors(finallySuccessor);
EmptyBlockLogicalConstruct emptyCommonNode = new EmptyBlockLogicalConstruct(++logicalContext.MaxBlockIndex);
emptyCommonNode.AddToPredecessors(disposeCallBlock);
emptyCommonNode.AddToPredecessors(conditionBlock);
disposeCallBlock.AddToSuccessors(emptyCommonNode);
conditionBlock.AddToSuccessors(emptyCommonNode);
emptyCommonNode.Parent = finallyEntryBlock.Parent;
emptyCommonNode.Parent.Children.Add(emptyCommonNode);
for (int i = 0; i < conditionBlock.TheBlock.Successors.Length; i++)
{
if (conditionBlock.TheBlock.Successors[i] == finallySuccessor.TheBlock)
{
conditionBlock.TheBlock.Successors[i] = null;
}
}
finallyBlocks.Add(emptyCommonNode);
return(new BlockLogicalConstruct(finallyEntryBlock, finallyBlocks));
}
/// <summary>
/// Gets a string representation of the instruction block offset that this CFG block logical construct node represents.
/// </summary>
/// <remarks>
/// If the <paramref name="node"/> is partial CFG block logical construct then the string representing its offset is:
/// "{offset of the instruction block}_{partial construct index}"
/// Where the partial construct index is the index of the partial construct in the <paramref name="context"/>.CFGBlockToLogicalConstructMap.
/// </remarks>
/// <param name="context"></param>
/// <param name="node"></param>
/// <returns></returns>
protected string NodeILOffset(LogicalFlowBuilderContext context, CFGBlockLogicalConstruct node)
{
if (node == null)
{
return("null");
}
//If the CFG construct is a partial block, the offset is: "blockOffset_indexOfPartialBlock"
PartialCFGBlockLogicalConstruct partialNode = node as PartialCFGBlockLogicalConstruct;
if (partialNode != null)
{
int indexOfPartialConstruct = Array.IndexOf(context.CFGBlockToLogicalConstructMap[partialNode.TheBlock], partialNode);
if (indexOfPartialConstruct == -1)
{
//sanity check
throw new Exception("Invalid partial block data.");
}
return(string.Format("IL_{0}_{1}", partialNode.TheBlock.First.Offset.ToString("x4"), indexOfPartialConstruct));
}
else
{
return(string.Format("IL_{0}", node.TheBlock.First.Offset.ToString("x4")));
}
}
public PartialCFGBlockLogicalConstruct(CFGBlockLogicalConstruct originalCFGConstruct, IEnumerable <Expression> expressions)
{
base(originalCFGConstruct.get_TheBlock(), expressions);
this.set_OriginalCFGConstruct(originalCFGConstruct);
this.RedirectParent();
return;
}
public static KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct> SplitCFGBlockAt(LogicalFlowBuilderContext logicalContext, CFGBlockLogicalConstruct cfgBlock, int expressionIndex)
{
V_0 = cfgBlock.get_LogicalConstructExpressions();
if (V_0 == null)
{
throw new ArgumentNullException("blockExpressions");
}
if (expressionIndex <= 0 || expressionIndex >= V_0.get_Count())
{
throw new ArgumentOutOfRangeException("expressionIndex");
}
V_1 = logicalContext.get_CFGBlockToLogicalConstructMap().get_Item(cfgBlock.get_TheBlock());
V_2 = (int)V_1.Length;
V_3 = 0;
while (V_3 < V_2 && cfgBlock != V_1[V_3])
{
V_3 = V_3 + 1;
}
if (V_3 == V_2)
{
throw new ArgumentException("cfgBlock");
}
V_4 = cfgBlock.get_LogicalConstructExpressions().GetRange(0, expressionIndex);
V_5 = new PartialCFGBlockLogicalConstruct(cfgBlock, V_4);
V_5.RedirectPredecessors();
V_6 = cfgBlock.get_LogicalConstructExpressions().GetRange(expressionIndex, V_0.get_Count() - expressionIndex);
V_7 = new PartialCFGBlockLogicalConstruct(cfgBlock, V_6);
V_7.RedirectSuccessors();
V_5.AddToSuccessors(V_7);
V_7.AddToPredecessors(V_5);
V_8 = new CFGBlockLogicalConstruct[V_2 + 1];
V_9 = 0;
V_10 = 0;
while (V_9 < V_2)
{
if (V_9 == V_3)
{
V_8[V_10] = V_5;
stackVariable68 = V_10 + 1;
V_10 = stackVariable68;
V_8[stackVariable68] = V_7;
}
else
{
V_8[V_10] = V_1[V_9];
}
V_9 = V_9 + 1;
V_10 = V_10 + 1;
}
logicalContext.get_CFGBlockToLogicalConstructMap().set_Item(cfgBlock.get_TheBlock(), V_8);
return(new KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct>(V_5, V_7));
}
/// <summary>
/// Gets the CFGBlockLC children of theBlock sorted in reverse post order.
/// </summary>
private void GetOrderedCFGNodes()
{
DFSTree dfsTree = DFSTBuilder.BuildTree(theBlock);
foreach (DFSTNode node in dfsTree.ReversePostOrder)
{
CFGBlockLogicalConstruct cfgConstruct = node.Construct as CFGBlockLogicalConstruct;
if (cfgConstruct != null)
{
orderedCFGNodes.Add(cfgConstruct);
}
}
}
/// <summary>
/// Redirect the predecessors and successors of the finally block.
/// </summary>
/// <remarks>
/// Check if the finallyBlockEntry is only reachable by nodes in the try block.
/// Make the successor of the finallyBlockEnd successor to all of the predecessors of the finallyBlockEntry.
/// This will detach the finally block from the subgraph, which is a desired result since every normal finally block is not reachable from any where
/// (the CLR takes care of executing the code in the finally block).
/// </remarks>
/// <param name="finallyBlockEntry"></param>
/// <param name="finallyBlockEnd"></param>
/// <returns>The successor of the finally block.</returns>
private CFGBlockLogicalConstruct ProcessFinallyNode(CFGBlockLogicalConstruct finallyBlockEntry, CFGBlockLogicalConstruct finallyBlockEnd)
{
foreach (ILogicalConstruct predecessor in finallyBlockEntry.SameParentPredecessors)
{
if (!newTryBody.Contains(predecessor))
{
throw new Exception("Invalid entry to the finally block");
}
}
CFGBlockLogicalConstruct finallySuccessor;
using (IEnumerator <CFGBlockLogicalConstruct> enumerator = finallyBlockEnd.CFGSuccessors.GetEnumerator())
{
enumerator.MoveNext();
finallySuccessor = enumerator.Current;
if (enumerator.MoveNext())
{
throw new Exception("Invalid count of successors");
}
}
HashSet <CFGBlockLogicalConstruct> finallyCFGPredecessors = new HashSet <CFGBlockLogicalConstruct>(finallyBlockEntry.CFGPredecessors);
foreach (CFGBlockLogicalConstruct cfgPredecessor in finallyCFGPredecessors)
{
if (cfgPredecessor.TheBlock != finallyBlockEntry.TheBlock && cfgPredecessor.TheBlock.Successors.Length > 1)
{
ProcessMultiWayCFGPredecessor(finallyBlockEntry, cfgPredecessor.TheBlock, finallySuccessor.TheBlock);
}
LogicalConstructBase currenConstruct = cfgPredecessor;
while (currenConstruct != finallyBlockEntry.Parent)
{
currenConstruct.RemoveFromSuccessors(finallyBlockEntry);
currenConstruct.AddToSuccessors(finallySuccessor);
currenConstruct = currenConstruct.Parent as LogicalConstructBase;
}
finallySuccessor.AddToPredecessors(cfgPredecessor);
finallyBlockEntry.RemoveFromPredecessors(cfgPredecessor);
}
finallySuccessor.RemoveFromPredecessors(finallyBlockEnd);
finallyBlockEnd.RemoveFromSuccessors(finallySuccessor);
return(finallySuccessor);
}
/// <summary>
/// Initializes the block logical construct representing the method body.
/// </summary>
private void InitializeTheBlock()
{
MapBlocks();
CFGBlockLogicalConstruct entry = logicalBuilderContext.CFGBlockToLogicalConstructMap[logicalBuilderContext.CFG.Blocks[0]][0];
HashSet <ILogicalConstruct> blockContents = new HashSet <ILogicalConstruct>();
foreach (CFGBlockLogicalConstruct[] cfgBlocks in logicalBuilderContext.CFGBlockToLogicalConstructMap.Values)
{
blockContents.UnionWith(cfgBlocks);
}
theBlockLogicalConstruct = new BlockLogicalConstruct(entry, blockContents);
}
protected string NodeILOffset(LogicalFlowBuilderContext context, CFGBlockLogicalConstruct node)
{
if (node == null)
{
return("null");
}
V_0 = node as PartialCFGBlockLogicalConstruct;
if (V_0 == null)
{
V_2 = node.get_TheBlock().get_First().get_Offset();
return(String.Format("IL_{0}", V_2.ToString("x4")));
}
V_1 = Array.IndexOf <CFGBlockLogicalConstruct>(context.get_CFGBlockToLogicalConstructMap().get_Item(V_0.get_TheBlock()), V_0);
if (V_1 == -1)
{
throw new Exception("Invalid partial block data.");
}
V_2 = V_0.get_TheBlock().get_First().get_Offset();
return(String.Format("IL_{0}_{1}", V_2.ToString("x4"), V_1));
}
/// <summary>
/// Splits each CFG construct that has more than one successor (i.e. condition block) and holds more than one expression.
/// </summary>
public void SplitConditionalCFGBlocks()
{
//We need to copy the dictionary, since the LogicalFlowUtilities.SplitCFGBlockAt method modifies it (and the enumerator explodes).
//Also we copy it in a list, since we don't need the functionality of the dictionary.
List <KeyValuePair <InstructionBlock, CFGBlockLogicalConstruct[]> > blockToConstructsPairList =
new List <KeyValuePair <InstructionBlock, CFGBlockLogicalConstruct[]> >(logicalContext.CFGBlockToLogicalConstructMap);
foreach (KeyValuePair <InstructionBlock, CFGBlockLogicalConstruct[]> blockToConstructsPair in blockToConstructsPairList)
{
if (blockToConstructsPair.Key.Successors.Length > 1)
{
//For each instruction block there can be more than one partial CFG LC, so we take the last one, since it will hold the condition expression.
CFGBlockLogicalConstruct cfgConstruct = blockToConstructsPair.Value[blockToConstructsPair.Value.Length - 1];
if (cfgConstruct.LogicalConstructExpressions.Count > 1)
{
//If the last construct for this block holds more than one expression we split it at the last expression.
LogicalFlowUtilities.SplitCFGBlockAt(logicalContext, cfgConstruct, cfgConstruct.LogicalConstructExpressions.Count - 1);
}
}
}
}
private void DetachFromLogicalTree(CFGBlockLogicalConstruct node)
{
if (node.get_CFGPredecessors().get_Count() > 0 || node.get_CFGSuccessors().get_Count() > 0)
{
throw new Exception("This node cannot be detached from the logical tree.");
}
dummyVar0 = node.get_Parent().get_Children().Remove(node);
V_0 = this.logicalContext.get_CFGBlockToLogicalConstructMap().get_Item(node.get_TheBlock());
if ((int)V_0.Length == 1)
{
if (V_0[0] != node)
{
throw new Exception("Logical tree is inconsistent.");
}
dummyVar1 = this.logicalContext.get_CFGBlockToLogicalConstructMap().Remove(node.get_TheBlock());
}
V_1 = new CFGBlockLogicalConstruct[(int)V_0.Length - 1];
V_2 = 0;
V_3 = 0;
while (V_2 < (int)V_0.Length)
{
if (V_0[V_2] != node)
{
if (V_3 == (int)V_0.Length)
{
throw new Exception("Logical tree is inconsistent.");
}
V_1[V_3] = V_0[V_2];
}
else
{
V_3 = V_3 - 1;
}
V_2 = V_2 + 1;
V_3 = V_3 + 1;
}
this.logicalContext.get_CFGBlockToLogicalConstructMap().set_Item(node.get_TheBlock(), V_1);
return;
}
private void DetachFromLogicalTree(CFGBlockLogicalConstruct node)
{
if (node.CFGPredecessors.Count > 0 || node.CFGSuccessors.Count > 0)
{
throw new Exception("This node cannot be detached from the logical tree.");
}
node.Parent.Children.Remove(node);
CFGBlockLogicalConstruct[] cfgConstructsArray = logicalContext.CFGBlockToLogicalConstructMap[node.TheBlock];
if (cfgConstructsArray.Length == 1)
{
if (cfgConstructsArray[0] != node)
{
throw new Exception("Logical tree is inconsistent.");
}
logicalContext.CFGBlockToLogicalConstructMap.Remove(node.TheBlock);
}
CFGBlockLogicalConstruct[] newCFGConstructsArray = new CFGBlockLogicalConstruct[cfgConstructsArray.Length - 1];
for (int i = 0, j = 0; i < cfgConstructsArray.Length; i++, j++)
{
if (cfgConstructsArray[i] == node)
{
--j;
continue;
}
if (j == cfgConstructsArray.Length)
{
throw new Exception("Logical tree is inconsistent.");
}
newCFGConstructsArray[j] = cfgConstructsArray[i];
}
logicalContext.CFGBlockToLogicalConstructMap[node.TheBlock] = newCFGConstructsArray;
}
/// <summary>
/// Maps each CFG instruction blocks to a new CFGBlockLogicalConstruct, creating the relations between the new constructs and updating the logical builder
/// context.
/// </summary>
private void MapBlocks()
{
//The new CFG logical constructs hold the block that they represent, and all the expressions that are for this block.
foreach (InstructionBlock instructionBlock in logicalBuilderContext.CFG.Blocks)
{
int offset = instructionBlock.First.Offset;
logicalBuilderContext.CFGBlockToLogicalConstructMap.Add(instructionBlock,
new CFGBlockLogicalConstruct[] { new CFGBlockLogicalConstruct(instructionBlock, methodContext.Expressions.BlockExpressions[offset]) });
}
//After creating all the blocks, we can add the relations between them.
foreach (InstructionBlock instructionBlock in logicalBuilderContext.CFG.Blocks)
{
CFGBlockLogicalConstruct logicalConstruct = logicalBuilderContext.CFGBlockToLogicalConstructMap[instructionBlock][0];
foreach (InstructionBlock successorBlock in instructionBlock.Successors)
{
CFGBlockLogicalConstruct successorConstruct = logicalBuilderContext.CFGBlockToLogicalConstructMap[successorBlock][0];
logicalConstruct.AddToSuccessors(successorConstruct);
successorConstruct.AddToPredecessors(logicalConstruct);
}
}
}
/// <summary>
/// Determines whether or not there is a conditional dispose starting from this block.
/// </summary>
/// <remarks>
/// Since the conditional dispose is the same as in the Dispose method, we are trying to find the same pattern.
/// <code>
/// this.stateField = nextState;
/// (this.disposableField = this.enumeratorField as IDisposable;) -- this might be missing
/// if(this.disposableField != null)
/// {
/// this.disposableField.Dispose();
/// }
/// </code>
/// </remarks>
/// <param name="yieldExceptionHandler"></param>
/// <param name="startBlock"></param>
/// <returns></returns>
private bool TryProcessConditionalDisposeHandler(YieldExceptionHandlerInfo yieldExceptionHandler, CFGBlockLogicalConstruct startBlock)
{
if (finallyBlocks.Count > 0)
{
return(false);
}
if (!(startBlock is PartialCFGBlockLogicalConstruct) || startBlock.CFGSuccessors.Count != 1)
{
return(false);
}
if (startBlock.LogicalConstructExpressions.Count == 0)
{
return(false);
}
BinaryExpression stateAssignExpression = startBlock.LogicalConstructExpressions[0] as BinaryExpression;
if (stateAssignExpression == null || !stateAssignExpression.IsAssignmentExpression ||
stateAssignExpression.Left.CodeNodeType != CodeNodeType.FieldReferenceExpression ||
(stateAssignExpression.Left as FieldReferenceExpression).Field.Resolve() != stateFieldRef ||
stateAssignExpression.Right.CodeNodeType != CodeNodeType.LiteralExpression ||
(int)((stateAssignExpression.Right as LiteralExpression).Value) != yieldExceptionHandler.NextState)
{
return(false);
}
if (startBlock.LogicalConstructExpressions.Count == 2 && yieldExceptionHandler.HandlerType == YieldExceptionHandlerType.ConditionalDispose)
{
BinaryExpression disposableAssignExpression = startBlock.LogicalConstructExpressions[1] as BinaryExpression;
if (disposableAssignExpression == null || !disposableAssignExpression.IsAssignmentExpression ||
disposableAssignExpression.Left.CodeNodeType != CodeNodeType.FieldReferenceExpression ||
(disposableAssignExpression.Left as FieldReferenceExpression).Field != yieldExceptionHandler.DisposableField ||
disposableAssignExpression.Right.CodeNodeType != CodeNodeType.SafeCastExpression ||
(disposableAssignExpression.Right as SafeCastExpression).Expression.CodeNodeType != CodeNodeType.FieldReferenceExpression ||
((disposableAssignExpression.Right as SafeCastExpression).Expression as FieldReferenceExpression).Field != yieldExceptionHandler.EnumeratorField)
{
return(false);
}
}
else if (startBlock.LogicalConstructExpressions.Count != 1 || yieldExceptionHandler.HandlerType != YieldExceptionHandlerType.SimpleConditionalDispose)
{
return(false);
}
CFGBlockLogicalConstruct conditionBlock;
IEnumerator <CFGBlockLogicalConstruct> enumerator = startBlock.CFGSuccessors.GetEnumerator();
using (enumerator)
{
enumerator.MoveNext();
conditionBlock = enumerator.Current;
}
if (conditionBlock.LogicalConstructExpressions.Count != 1)
{
return(false);
}
BinaryExpression isNullCheckExpression = conditionBlock.LogicalConstructExpressions[0] as BinaryExpression;
if (isNullCheckExpression == null || isNullCheckExpression.Operator != BinaryOperator.ValueEquality ||
isNullCheckExpression.Left.CodeNodeType != CodeNodeType.FieldReferenceExpression ||
(isNullCheckExpression.Left as FieldReferenceExpression).Field != yieldExceptionHandler.DisposableField ||
isNullCheckExpression.Right.CodeNodeType != CodeNodeType.LiteralExpression ||
(isNullCheckExpression.Right as LiteralExpression).Value != null)
{
return(false);
}
CFGBlockLogicalConstruct disposeCallBlock = null;
foreach (ILogicalConstruct successor in conditionBlock.CFGSuccessors)
{
CFGBlockLogicalConstruct cfgSuccessor = successor as CFGBlockLogicalConstruct;
if (cfgSuccessor != null && cfgSuccessor.CFGPredecessors.Count == 1)
{
disposeCallBlock = cfgSuccessor;
break;
}
}
if (disposeCallBlock == null || disposeCallBlock.LogicalConstructExpressions.Count != 1)
{
return(false);
}
MethodInvocationExpression disposeMethodInvocation = disposeCallBlock.LogicalConstructExpressions[0] as MethodInvocationExpression;
if (disposeMethodInvocation == null || !disposeMethodInvocation.VirtualCall ||
disposeMethodInvocation.MethodExpression.Target.CodeNodeType != CodeNodeType.FieldReferenceExpression ||
(disposeMethodInvocation.MethodExpression.Target as FieldReferenceExpression).Field != yieldExceptionHandler.DisposableField ||
disposeMethodInvocation.MethodExpression.Method.Name != "Dispose")
{
return(false);
}
this.finallyEntryBlock = startBlock;
finallyBlocks.Add(startBlock);
this.conditionBlock = conditionBlock;
finallyBlocks.Add(conditionBlock);
this.disposeCallBlock = disposeCallBlock;
finallyBlocks.Add(disposeCallBlock);
return(true);
}
/// <summary>
/// Redirect the predecessors and successors of the finally node.
/// </summary>
/// <remarks>
/// Check if the finally node is only reachable by nodes in the try block.
/// Make the successor of the finally node successor to all of the predecessors of the finally node.
/// This will detach the finally node from the subgraph, which is a desired result since every normal finally block is not reachable from any where
/// (the CLR takes care of executing the code in the finally block).
/// </remarks>
/// <param name="finallyCFGBlock"></param>
private void ProcessFinallyNode(CFGBlockLogicalConstruct finallyCFGBlock)
{
ProcessFinallyNode(finallyCFGBlock, finallyCFGBlock);
}
private bool TryProcessConditionalDisposeHandler(YieldExceptionHandlerInfo yieldExceptionHandler, CFGBlockLogicalConstruct startBlock)
{
if (this.finallyBlocks.get_Count() > 0)
{
return(false);
}
if (startBlock as PartialCFGBlockLogicalConstruct == null || startBlock.get_CFGSuccessors().get_Count() != 1)
{
return(false);
}
if (startBlock.get_LogicalConstructExpressions().get_Count() == 0)
{
return(false);
}
V_0 = startBlock.get_LogicalConstructExpressions().get_Item(0) as BinaryExpression;
if (V_0 == null || !V_0.get_IsAssignmentExpression() || V_0.get_Left().get_CodeNodeType() != 30 || (V_0.get_Left() as FieldReferenceExpression).get_Field().Resolve() != this.stateFieldRef || V_0.get_Right().get_CodeNodeType() != 22 || (Int32)(V_0.get_Right() as LiteralExpression).get_Value() != yieldExceptionHandler.get_NextState())
{
return(false);
}
if (startBlock.get_LogicalConstructExpressions().get_Count() != 2 || yieldExceptionHandler.get_HandlerType() != 2)
{
if (startBlock.get_LogicalConstructExpressions().get_Count() != 1 || yieldExceptionHandler.get_HandlerType() != 1)
{
return(false);
}
}
else
{
V_6 = startBlock.get_LogicalConstructExpressions().get_Item(1) as BinaryExpression;
if (V_6 == null || !V_6.get_IsAssignmentExpression() || V_6.get_Left().get_CodeNodeType() != 30 || (object)(V_6.get_Left() as FieldReferenceExpression).get_Field() != (object)yieldExceptionHandler.get_DisposableField() || V_6.get_Right().get_CodeNodeType() != 33 || (V_6.get_Right() as SafeCastExpression).get_Expression().get_CodeNodeType() != 30 || (object)((V_6.get_Right() as SafeCastExpression).get_Expression() as FieldReferenceExpression).get_Field() != (object)yieldExceptionHandler.get_EnumeratorField())
{
return(false);
}
}
V_2 = startBlock.get_CFGSuccessors().GetEnumerator();
V_7 = V_2;
try
{
dummyVar0 = V_2.MoveNext();
V_1 = V_2.get_Current();
}
finally
{
if (V_7 != null)
{
V_7.Dispose();
}
}
if (V_1.get_LogicalConstructExpressions().get_Count() != 1)
{
return(false);
}
V_3 = V_1.get_LogicalConstructExpressions().get_Item(0) as BinaryExpression;
if (V_3 == null || V_3.get_Operator() != 9 || V_3.get_Left().get_CodeNodeType() != 30 || (object)(V_3.get_Left() as FieldReferenceExpression).get_Field() != (object)yieldExceptionHandler.get_DisposableField() || V_3.get_Right().get_CodeNodeType() != 22 || (V_3.get_Right() as LiteralExpression).get_Value() != null)
{
return(false);
}
V_4 = null;
V_8 = V_1.get_CFGSuccessors().GetEnumerator();
try
{
while (V_8.MoveNext())
{
V_9 = V_8.get_Current() as CFGBlockLogicalConstruct;
if (V_9 == null || V_9.get_CFGPredecessors().get_Count() != 1)
{
continue;
}
V_4 = V_9;
goto Label0;
}
}
finally
{
((IDisposable)V_8).Dispose();
}
Label0:
if (V_4 == null || V_4.get_LogicalConstructExpressions().get_Count() != 1)
{
return(false);
}
V_5 = V_4.get_LogicalConstructExpressions().get_Item(0) as MethodInvocationExpression;
if (V_5 == null || !V_5.get_VirtualCall() || V_5.get_MethodExpression().get_Target().get_CodeNodeType() != 30 || (object)(V_5.get_MethodExpression().get_Target() as FieldReferenceExpression).get_Field() != (object)yieldExceptionHandler.get_DisposableField() || String.op_Inequality(V_5.get_MethodExpression().get_Method().get_Name(), "Dispose"))
{
return(false);
}
this.finallyEntryBlock = startBlock;
dummyVar1 = this.finallyBlocks.Add(startBlock);
this.conditionBlock = V_1;
dummyVar2 = this.finallyBlocks.Add(V_1);
this.disposeCallBlock = V_4;
dummyVar3 = this.finallyBlocks.Add(V_4);
return(true);
}
/// <summary>
/// Checks each a node before adding its successors to the <paramref name="bfsQueue"/>.
/// </summary>
/// <remarks>
/// If the node is a CFGBlockLC and it contains the invocation of the finally method, or the entry of the finally block,
/// then we should not continue the traversal.
/// </remarks>
/// <param name="handlerInfo"></param>
/// <param name="bfsQueue"></param>
/// <param name="currentNode"></param>
private void ProcessCurrentNode(YieldExceptionHandlerInfo handlerInfo, Queue <ILogicalConstruct> bfsQueue, ILogicalConstruct currentNode)
{
if (currentNode is CFGBlockLogicalConstruct)
{
CFGBlockLogicalConstruct currentCFGNode = currentNode as CFGBlockLogicalConstruct;
for (int i = 0; i < currentCFGNode.LogicalConstructExpressions.Count; i++)
{
Expression currentExpression = currentCFGNode.LogicalConstructExpressions[i];
int value;
if (TryGetStateAssignValue(currentExpression, out value))
{
if (!handlerInfo.TryStates.Contains(value)) //sanity check
{
if (handlerInfo.HandlerType != YieldExceptionHandlerType.Method &&
TryProcessConditionalDisposeHandler(handlerInfo, currentCFGNode))
{
return;
}
throw new Exception("Invalid state value");
}
}
else if (handlerInfo.HandlerType == YieldExceptionHandlerType.Method &&
currentExpression.CodeNodeType == CodeNodeType.MethodInvocationExpression &&
(currentExpression as MethodInvocationExpression).MethodExpression.MethodDefinition == handlerInfo.FinallyMethodDefinition)
{
//For the finally block we need the CFGBlockLC that contains only the invocation of the finally method.
//That's why we need to split the CFGBlockLC, if there are other expressions besides the invocation.
CFGBlockLogicalConstruct currentFinallyBlock;
if (currentCFGNode.LogicalConstructExpressions.Count == 1)
{
if (newFinallyBody == null)
{
newFinallyBody = currentCFGNode;
}
finallyBlocks.Add(newFinallyBody);
orderedCFGNodes.Remove(currentCFGNode);
return;
}
if (i == 0)
{
KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct> newConstructsPair =
LogicalFlowUtilities.SplitCFGBlockAt(logicalContext, currentCFGNode, i + 1);
currentFinallyBlock = newConstructsPair.Key;
orderedCFGNodes[orderedCFGNodes.IndexOf(currentCFGNode)] = newConstructsPair.Value;
}
else if (i < currentCFGNode.LogicalConstructExpressions.Count - 1)
{
KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct> endOfTryPair =
LogicalFlowUtilities.SplitCFGBlockAt(logicalContext, currentCFGNode, i);
newTryBody.Add(endOfTryPair.Key);
KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct> finallyRestOfBlockPair =
LogicalFlowUtilities.SplitCFGBlockAt(logicalContext, endOfTryPair.Value, 1);
currentFinallyBlock = finallyRestOfBlockPair.Key;
orderedCFGNodes[orderedCFGNodes.IndexOf(currentCFGNode)] = finallyRestOfBlockPair.Value;
}
else // i == count - 1
{
KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct> tryFinallyPair =
LogicalFlowUtilities.SplitCFGBlockAt(logicalContext, currentCFGNode, i);
newTryBody.Add(tryFinallyPair.Key);
currentFinallyBlock = tryFinallyPair.Value;
orderedCFGNodes.Remove(currentCFGNode);
}
if (newFinallyBody == null)
{
newFinallyBody = currentFinallyBlock;
}
finallyBlocks.Add(currentFinallyBlock);
return;
}
}
}
else if (currentNode is TryFinallyLogicalConstruct)
{
TryFinallyLogicalConstruct tryFinallyConstruct = currentNode as TryFinallyLogicalConstruct;
YieldExceptionHandlerInfo oldHandlerInfo;
if (createdConstructsToIntervalMap.TryGetValue(tryFinallyConstruct, out oldHandlerInfo) &&
oldHandlerInfo.TryStates.IsProperSupersetOf(handlerInfo.TryStates))
{
throw new Exception("This try/finally construct cannot be nested in the current construct");
}
}
newTryBody.Add(currentNode);
foreach (ILogicalConstruct successor in currentNode.SameParentSuccessors)
{
bfsQueue.Enqueue(successor);
}
}
public PartialCFGBlockLogicalConstruct(CFGBlockLogicalConstruct originalCFGConstruct, IEnumerable <Expression> expressions)
: base(originalCFGConstruct.TheBlock, expressions)
{
OriginalCFGConstruct = originalCFGConstruct;
RedirectParent();
}
/// <summary>
/// Splits the given CFG construct into two partial constructs. The first containing the expressions with indices 0 to expressionIndex - 1, the second -
/// expressionIndex to end. This method modifies the logicalContext.CFGBlockToLogicalConstructMap
/// </summary>
/// <param name="logicalContext"></param>
/// <param name="cfgBlock"></param>
/// <param name="expressionIndex"></param>
/// <returns>A key value pair containing the first partial construct as key and the second as value.</returns>
public static KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct> SplitCFGBlockAt(LogicalFlowBuilderContext logicalContext,
CFGBlockLogicalConstruct cfgBlock, int expressionIndex)
{
List <Expression> blockExpressions = cfgBlock.LogicalConstructExpressions;
if (blockExpressions == null)
{
throw new ArgumentNullException("blockExpressions");
}
if (expressionIndex <= 0 || expressionIndex >= blockExpressions.Count)
{
throw new ArgumentOutOfRangeException("expressionIndex");
}
CFGBlockLogicalConstruct[] instructionBlockConstructs = logicalContext.CFGBlockToLogicalConstructMap[cfgBlock.TheBlock];
int cfgBlockArrayLength = instructionBlockConstructs.Length;
int cfgBlockIndex;
for (cfgBlockIndex = 0; cfgBlockIndex < cfgBlockArrayLength; cfgBlockIndex++)
{
if (cfgBlock == instructionBlockConstructs[cfgBlockIndex])
{
break;
}
}
if (cfgBlockIndex == cfgBlockArrayLength)
{
throw new ArgumentException("cfgBlock");
}
List <Expression> firstExpressionsList = cfgBlock.LogicalConstructExpressions.GetRange(0, expressionIndex);
PartialCFGBlockLogicalConstruct firstPartial = new PartialCFGBlockLogicalConstruct(cfgBlock, firstExpressionsList);
firstPartial.RedirectPredecessors();
List <Expression> secondExpressionsList = cfgBlock.LogicalConstructExpressions.GetRange(expressionIndex, blockExpressions.Count - expressionIndex);
PartialCFGBlockLogicalConstruct secondPartial = new PartialCFGBlockLogicalConstruct(cfgBlock, secondExpressionsList);
secondPartial.RedirectSuccessors();
firstPartial.AddToSuccessors(secondPartial);
secondPartial.AddToPredecessors(firstPartial);
CFGBlockLogicalConstruct[] updatedCollection = new CFGBlockLogicalConstruct[cfgBlockArrayLength + 1];
for (int i = 0, j = 0; i < cfgBlockArrayLength; i++, j++)
{
if (i != cfgBlockIndex)
{
updatedCollection[j] = instructionBlockConstructs[i];
}
else
{
updatedCollection[j] = firstPartial;
updatedCollection[++j] = secondPartial;
}
}
logicalContext.CFGBlockToLogicalConstructMap[cfgBlock.TheBlock] = updatedCollection;
return(new KeyValuePair <CFGBlockLogicalConstruct, CFGBlockLogicalConstruct>(firstPartial, secondPartial));
}
/// <summary>
/// Adds the given CFG construct as a predecessor of this construct. This is the only legal way to do so.
/// </summary>
/// <param name="predecessor"></param>
public void AddToPredecessors(CFGBlockLogicalConstruct predecessor)
{
predecessors.Add(predecessor);
}
public bool RemoveFromPredecessors(CFGBlockLogicalConstruct predecessor)
{
return(this.predecessors.Remove(predecessor));
}
public void AddToPredecessors(CFGBlockLogicalConstruct predecessor)
{
dummyVar0 = this.predecessors.Add(predecessor);
return;
}
/// <summary>
/// Gets a string representation of this logical construct.
/// </summary>
/// <remarks>
/// Used for testing purposes.
/// </remarks>
/// <param name="constructName">The name of the construct.</param>
/// <param name="printedCFGBlocks">A set containing all of the CFG block logical constructs that are already traversed.</param>
/// <param name="context">The current logical flow builder context.</param>
/// <returns></returns>
protected virtual string ToString(string constructName, HashSet <CFGBlockLogicalConstruct> printedCFGBlocks, LogicalFlowBuilderContext context)
{
StringBuilder sb = new StringBuilder();
sb.AppendLine(constructName);
sb.AppendLine("{");
ILogicalConstruct[] cfgBlocksArray = GetSortedArrayFromCollection(this.CFGBlocks);
Stack <CFGBlockLogicalConstruct> printingStack = new Stack <CFGBlockLogicalConstruct>();
for (int i = 0; i < cfgBlocksArray.Length; i++)
{
CFGBlockLogicalConstruct currentCFGBlock = cfgBlocksArray[i] as CFGBlockLogicalConstruct;
//If the current node is already printed we skip it.
if (printedCFGBlocks.Contains(currentCFGBlock))
{
continue;
}
//We use a stack to print the constructs in preorder.
printingStack.Push(currentCFGBlock);
while (printingStack.Count > 0)
{
CFGBlockLogicalConstruct blockToPrint = printingStack.Pop();
if (printedCFGBlocks.Contains(blockToPrint))
{
continue;
}
//Foreach CFG construct that is not printed we get the parent (not necessarily direct) logical construct that is child of this construct
//(i.e. childConstructToPrint is the child of this construct that contains the blockToPrint).
ILogicalConstruct childConstructToPrint;
if (!LogicalFlowUtilities.TryGetParentConstructWithGivenParent(blockToPrint, this, out childConstructToPrint))
{
continue;
}
string childString = ((LogicalConstructBase)childConstructToPrint).ToString(childConstructToPrint.GetType().Name, printedCFGBlocks, context);
//Indent each line of child's strings by one tab, so that they appear visually better
string[] childStringLines = childString.Split(new String[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
foreach (string line in childStringLines)
{
sb.AppendLine(string.Format("\t{0}", line));
}
//We get a sorted array ot the child's same parent successors and we push their CFG logical construct entries in reverse order on the
//printing stack, so that the closest successor is going to be printed next.
ILogicalConstruct[] sameParentSuccessors = GetSortedArrayFromCollection(childConstructToPrint.SameParentSuccessors);
for (int j = sameParentSuccessors.Length - 1; j >= 0; j--)
{
if (!printedCFGBlocks.Contains(sameParentSuccessors[j].FirstBlock))
{
printingStack.Push(sameParentSuccessors[j].FirstBlock);
}
}
}
}
string followNodeString = string.Format("\tFollowNode: {0}", NodeILOffset(context, CFGFollowNode));
sb.AppendLine(followNodeString);
sb.AppendLine("}");
return(sb.ToString());
}