private SymbolicExpressionTracker <Variable, Expression> RenameInternal(Dictionary <Variable, FList <Variable> > renaming, Variable slackVar)
{
Contract.Requires(renaming != null);
Contract.Ensures(Contract.Result <SymbolicExpressionTracker <Variable, Expression> >() != null);
Contract.Ensures(renaming.Count == Contract.OldValue(renaming.Count));
if (symbolicConditions.IsNormal())
{
renaming[slackVar] = FList <Variable> .Cons(slackVar, FList <Variable> .Empty);
Set <Expression> result = new Set <Expression>();
foreach (var exp in symbolicConditions.Values)
{
result.AddIfNotNull(expressionRenamer(exp, renaming));
}
var renamedExpressions =
result.Count != 0 ?
new SetOfConstraints <Expression>(result, false) :
SetOfConstraints <Expression> .Unknown;
renaming.Remove(slackVar); // We should remove the slack variable!
return(new SymbolicExpressionTracker <Variable, Expression>(this.slackVar, symbolicConditions));
}
else
{
return(this);
}
}
private static FList <string> AddExtraArgs(FList <string> args, string serviceAddress)
{
if (!String.IsNullOrWhiteSpace(serviceAddress) && serviceAddress != "*") // if not specified and not wildcard, use default address
{
args = args.Cons("-serviceAddress:" + serviceAddress);
}
return(args);
}
/// <summary>
/// Assumes that exception edges always target join points, so we never need to reach
/// backwards across a throw edges.
/// </summary>
/// <param name="apc"></param>
/// <param name="ifMissing"></param>
/// <returns></returns>
public AState /*?*/ GetPreState(APC apc, AState /*?*/ ifMissing, out bool noInfo)
{
// Find closest preceeding cached point
// Keep a list of program points we visit backward so we can take the
// same path forward.
FList <APC> /*?*/ path = null;
APC current = apc;
APC pred;
AState /*?*/ state;
bool found;
while (!(found = this.TryPreStateCache(current, out state)) && !RequiresJoining(current) && !this.CacheThisPC(current) && this.cfg.HasSinglePredecessor(current, out pred))
{
current = pred;
path = path.Cons(current);
}
if (!found)
{
noInfo = true;
return(ifMissing); // unreachable
}
bool nonTrivialPath = path != null;
// Now forward simulate and cache
while (path != null)
{
if (IsBottom(path.Head, state))
{
noInfo = true; // equate no info with bottom since we cannot manufacture bottom here
return(state);
}
// must get a mutable version if we are going to change it.
state = MutableVersion(state, path.Head);
state = Transfer(path.Head, state);
if (IsBottom(path.Head, state))
{
noInfo = false;
return(state);
}
path = path.Tail;
if (path != null)
{
// cache on next
this.CachePreState(path.Head, ImmutableVersion(state, path.Head));
// this.joinState.Add(path.Head, state);
}
}
// cache on lookedup up apc
if (nonTrivialPath)
{
this.CachePreState(apc, ImmutableVersion(state, apc));
// this.joinState.Add(apc, state);
}
noInfo = false;
return(state);
}
private void AssignInParallel
(WeakUpperBoundsEqual <Variable, Expression> wubeq, WeakUpperBounds <Variable, Expression> wub,
Dictionary <Variable, FList <Variable> > sourcesToTargets, INumericalAbstractDomain <Variable, Expression> oracleDomain)
{
Contract.Requires(wubeq != null);
Contract.Requires(wub != null);
// adding the domain-generated variables to the map as identity
var oldToNewMap = new Dictionary <Variable, FList <Variable> >(sourcesToTargets);
if (!wubeq.IsTop)
{
foreach (var e in wubeq.SlackVariables)
{
oldToNewMap[e] = FList <Variable> .Cons(e, FList <Variable> .Empty);
}
}
if (!wub.IsTop)
{
foreach (var e in wub.SlackVariables)
{
oldToNewMap[e] = FList <Variable> .Cons(e, FList <Variable> .Empty);
}
}
// when x has several targets including itself, the canonical element shouldn't be itself
foreach (var sourceToTargets in sourcesToTargets)
{
var source = sourceToTargets.Key;
var targets = sourceToTargets.Value;
Contract.Assume(targets != null);
if (targets.Length() > 1 && targets.Head.Equals(source))
{
var tail = targets.Tail;
Contract.Assert(tail != null);
var newTargets = FList <Variable> .Cons(tail.Head, FList <Variable> .Cons(source, tail.Tail));
oldToNewMap[source] = newTargets;
}
}
AssignInParallelWUBSpecific(wub, oldToNewMap);
AssignInParallelWUBEQSpecific(wubeq, sourcesToTargets, oldToNewMap);
}
/// <summary>
/// Given a method driver, compute a parallel renaming relation between the (symbolic) values at the return point
/// of a method and those at the entry of the same method. This renaming relation will be used to map an abstract
/// state at the end of one pass of analysis to the starting point of the next pass.
///
/// Implementation is to use SymbolicValuesAt method to find symbolic values for "important" access pathes and
/// match the symbolic values that represent the same access path.
/// </summary>
/// <param name="driver"></param>
/// <returns></returns>
IFunctionalMap <Variable, FList <Variable> > GetFieldMapping(IMethodDriver <Local, Parameter, Method, Field, Property, Event, Type, Attribute, Assembly, Expression, Variable, ILogOptions>
driver, APC pc1, APC pc2)
{
FunctionalMap <Variable, FList <Variable> > fieldMapping = null;
fieldMapping = FunctionalMap <Variable, FList <Variable> > .Empty;
foreach (Pair <string, Variable> pair in SymbolicValuesAt(pc1, driver))
{
if (!fieldMapping.Contains(pair.Two))
{
fieldMapping = (FunctionalMap <Variable, FList <Variable> >)fieldMapping.Add(pair.Two, FList <Variable> .Empty);
}
foreach (Pair <string, Variable> pair2 in SymbolicValuesAt(pc2, driver))
{
if (pair.One == pair2.One)
{
FList <Variable> list = fieldMapping[pair.Two];
list = list.Cons(pair2.Two);
fieldMapping = (FunctionalMap <Variable, FList <Variable> >)fieldMapping.Add(pair.Two, list);
}
}
}
return(fieldMapping);
}
public static void Push <Arg0, Arg1, Arg2, Arg3, TResult>(Func <Func <Arg0, Arg1, Arg2, Arg3, TResult>, Arg0, Arg1, Arg2, Arg3, TResult> adapter)
{
currentCallAdapters = currentCallAdapters.Cons(adapter);
}
private static FList <IOperationExceptionInformation> PopPushHandlers(BasicBlock block, FList <IOperationExceptionInformation> currentHandlers, IOperationExceptionInformation[] handlers, ref FList <IOperationExceptionInformation> containingHandlers)
{
Contract.Requires(block != null);
Contract.Requires(handlers != null);
Contract.Requires(Contract.ForAll(handlers, h => h != null));
// pop fault/finally subroutines off subroutine stack whose scope ends here
var blockOffset = block.Offset;
#region Pop protecting handlers off stack whose scope ends here
for (int i = 0; i < handlers.Length; i++)
{
if (handlers[i].TryEndOffset == blockOffset)
{
// must be head
if (currentHandlers != null && Object.Equals(handlers[i], currentHandlers.Head))
{
currentHandlers = currentHandlers.Tail;
}
else
{
throw new ApplicationException("bad order of handlers");
}
}
}
#endregion
#region Push protecting handlers on stack whose scope starts here
// reverse order
for (int i = handlers.Length - 1; i >= 0; i--)
{
if (handlers[i].TryStartOffset == blockOffset)
{
// push this handler on top of current block enclosing handlers
currentHandlers = FList <IOperationExceptionInformation> .Cons(handlers[i], currentHandlers); // Push handler
}
}
#endregion
#region Pop containing handlers off containing handler stack whose scope ends here
for (int i = 0; i < handlers.Length; i++)
{
if (handlers[i].HandlerEndOffset == blockOffset)
{
// must be head
if (containingHandlers != null && Object.Equals(handlers[i], containingHandlers.Head))
{
containingHandlers = containingHandlers.Tail;
}
else
{
throw new ApplicationException("bad order of handlers");
}
}
}
#endregion
#region Push containing handler on stack whose scope starts here
// reverse order
for (int i = handlers.Length - 1; i >= 0; i--)
{
if (handlers[i].HandlerStartOffset == blockOffset)
{
// push this handler on top of containing handlers
containingHandlers = FList <IOperationExceptionInformation> .Cons(handlers[i], containingHandlers); // Push handler
}
}
#endregion
// record handlers for this block
block.Handlers = currentHandlers;
block.ContainingHandler = (containingHandlers != null) ? containingHandlers.Head : null;
return(currentHandlers);
}
private void AddUpdate(Update upd)
{
Debug.Assert(!this.IsConstant, "modification of locked down egraph");
this.updates = FList.Cons(upd, this.updates);
}
/// <summary>
/// Compute a pre order (ignoring back edges) of the CFG reachable from the entry node
///
/// As a side effect, assigns each block its DF finishing number.
/// </summary>
public static FList /*<BasicBlocks>*/ Compute(ControlFlowGraph cfg)
{
// depth-first search
bool[] markBit = new bool[cfg.BlockCount];
FList result = null;
int DFTime = 0;
// Use a stack to represent the state of the search.
// Each stack element consists of a basic block and the
// the index of the next successor of that block to process.
Stack stack = new Stack();
CfgBlock[] blocks = cfg.Blocks();
CfgBlock start = cfg.Entry;
// invariant: all blocks pushed on the stack are marked.
markBit[start.Index] = true;
stack.Push(new StackElem(start));
while (stack.Count > 0)
{
StackElem elem = (StackElem)stack.Peek();
CfgBlock b = elem.node;
int nextChild = elem.nextChild;
CfgBlock[] normalNodes = cfg.NormalSucc(b);
CfgBlock[] exnNodes = cfg.ExcpSucc(b);
int normalNodesCount = normalNodes.Length;
int exnNodesCount = exnNodes.Length;
// Is there another child to process?
if (nextChild < normalNodesCount + exnNodesCount)
{
// Figure out the actual block.
CfgBlock child;
if (nextChild < normalNodesCount)
{
child = normalNodes[nextChild];
}
else
{
child = exnNodes[nextChild - normalNodesCount];
}
elem.nextChild = nextChild + 1;
// push the child block on to the stack.
if (!markBit[child.Index])
{
markBit[child.Index] = true;
stack.Push(new StackElem(child));
}
}
else
{
// After all children are processed, place the block
// on the result.
stack.Pop();
b.priority = ++DFTime;
result = FList.Cons(b, result);
}
}
return(result);
}
