unsigned UnwrappedLineFormatter::analyzeSolutionSpace(LineState &InitialState,
bool DryRun) {
std::set<LineState *, CompareLineStatePointers> Seen;
// Increasing count of \c StateNode items we have created. This is used to
// create a deterministic order independent of the container.
unsigned Count = 0;
QueueType Queue;
// Insert start element into queue.
StateNode *Node =
new (Allocator.Allocate()) StateNode(InitialState, false, nullptr);
Queue.push(QueueItem(OrderedPenalty(0, Count), Node));
++Count;
unsigned Penalty = 0;
// While not empty, take first element and follow edges.
while (!Queue.empty()) {
Penalty = Queue.top().first.first;
StateNode *Node = Queue.top().second;
if (!Node->State.NextToken) {
DEBUG(llvm::dbgs() << "\n---\nPenalty for line: " << Penalty << "\n");
break;
}
Queue.pop();
// Cut off the analysis of certain solutions if the analysis gets too
// complex. See description of IgnoreStackForComparison.
if (Count > 10000)
Node->State.IgnoreStackForComparison = true;
if (!Seen.insert(&Node->State).second)
// State already examined with lower penalty.
continue;
FormatDecision LastFormat = Node->State.NextToken->Decision;
if (LastFormat == FD_Unformatted || LastFormat == FD_Continue)
addNextStateToQueue(Penalty, Node, /*NewLine=*/false, &Count, &Queue);
if (LastFormat == FD_Unformatted || LastFormat == FD_Break)
addNextStateToQueue(Penalty, Node, /*NewLine=*/true, &Count, &Queue);
}
if (Queue.empty()) {
// We were unable to find a solution, do nothing.
// FIXME: Add diagnostic?
DEBUG(llvm::dbgs() << "Could not find a solution.\n");
return 0;
}
// Reconstruct the solution.
if (!DryRun)
reconstructPath(InitialState, Queue.top().second);
DEBUG(llvm::dbgs() << "Total number of analyzed states: " << Count << "\n");
DEBUG(llvm::dbgs() << "---\n");
return Penalty;
}
/// \brief Analyze the entire solution space starting from \p InitialState.
///
/// This implements a variant of Dijkstra's algorithm on the graph that spans
/// the solution space (\c LineStates are the nodes). The algorithm tries to
/// find the shortest path (the one with lowest penalty) from \p InitialState
/// to a state where all tokens are placed.
void analyzeSolutionSpace(LineState &InitialState) {
std::set<LineState> Seen;
// Insert start element into queue.
StateNode *Node =
new (Allocator.Allocate()) StateNode(InitialState, false, NULL);
Queue.push(QueueItem(OrderedPenalty(0, Count), Node));
++Count;
// While not empty, take first element and follow edges.
while (!Queue.empty()) {
unsigned Penalty = Queue.top().first.first;
StateNode *Node = Queue.top().second;
if (Node->State.NextToken == NULL) {
DEBUG(llvm::dbgs() << "\n---\nPenalty for line: " << Penalty << "\n");
break;
}
Queue.pop();
// Cut off the analysis of certain solutions if the analysis gets too
// complex. See description of IgnoreStackForComparison.
if (Count > 10000)
Node->State.IgnoreStackForComparison = true;
if (!Seen.insert(Node->State).second)
// State already examined with lower penalty.
continue;
addNextStateToQueue(Penalty, Node, /*NewLine=*/false);
addNextStateToQueue(Penalty, Node, /*NewLine=*/true);
}
if (Queue.empty())
// We were unable to find a solution, do nothing.
// FIXME: Add diagnostic?
return;
// Reconstruct the solution.
reconstructPath(InitialState, Queue.top().second);
DEBUG(llvm::dbgs() << "Total number of analyzed states: " << Count << "\n");
DEBUG(llvm::dbgs() << "---\n");
}
