@Override
/** comparison based on the child element */
public int compareTo(Edge pO) {
return Integer.compare(this.getChildState().getStateId(), pO.getChildState().getStateId());
}
private Collection<Edge> handleEdge(
Edge nextEdge,
Map<Integer, MergeNode> mergeNodes,
Set<ARGState> elementsOnPath,
EdgeVisitor callback) {
ARGState childElement = nextEdge.getChildState();
CFAEdge edge = nextEdge.getEdge();
Stack<FunctionBody> functionStack = nextEdge.getStack();
// clone stack to have a different representation of the function calls and conditions
// for every element
functionStack = cloneStack(functionStack);
// we do not have a single edge, instead a dynamic multi-edge
if (edge == null) {
List<CFAEdge> edges = nextEdge.getParentState().getEdgesToChild(childElement);
for (CFAEdge inner : edges) {
callback.visit(childElement, inner, functionStack);
}
} else {
callback.visit(childElement, edge, functionStack);
}
// how many parents does the child have?
// ignore parents not on the error path
int noOfParents = from(childElement.getParents()).filter(in(elementsOnPath)).size();
assert noOfParents >= 1;
// handle merging if necessary
if (noOfParents > 1) {
assert !((edge instanceof CFunctionCallEdge) || (childElement.isTarget()));
// this is the end of a condition, determine whether we should continue or backtrack
int elemId = childElement.getStateId();
FunctionBody currentFunction = functionStack.peek();
currentFunction.write("goto label_" + elemId + ";");
// get the merge node for that node
MergeNode mergeNode = mergeNodes.get(elemId);
// if null create new and put in the map
if (mergeNode == null) {
mergeNode = new MergeNode(elemId);
mergeNodes.put(elemId, mergeNode);
}
// this tells us the number of edges (entering that node) processed so far
int noOfProcessedBranches = mergeNode.addBranch(currentFunction);
// if all edges are processed
if (noOfParents == noOfProcessedBranches) {
// all branches are processed, now decide which nodes to remove from the stack
List<FunctionBody> incomingStacks = mergeNode.getIncomingStates();
FunctionBody newFunction = processIncomingStacks(incomingStacks);
// replace the current function body with the right one
functionStack.pop();
functionStack.push(newFunction);
newFunction.write("label_" + elemId + ": ;");
} else {
return Collections.emptySet();
}
}
return getRelevantChildrenOfState(childElement, functionStack, elementsOnPath);
}