public static boolean isChoiceStatement()

in src/org/jetbrains/java/decompiler/modules/decompiler/DecHelper.java [61:187]
106 lines of code
25 McCabe index (conditional complexity)

  public static boolean isChoiceStatement(Statement head, List<? super Statement> lst) {

    Statement post = null;

    Set<Statement> setDest = head.getNeighboursSet(EdgeType.REGULAR, EdgeDirection.FORWARD);

    if (setDest.contains(head)) {
      return false;
    }

    while (true) {

      lst.clear();

      boolean repeat = false;

      setDest.remove(post);

      for (Statement stat : setDest) {
        if (stat.getLastBasicType() != StatementType.GENERAL) {
          if (post == null) {
            post = stat;
            repeat = true;
            break;
          }
          else {
            return false;
          }
        }

        // preds
        Set<Statement> setPred = stat.getNeighboursSet(EdgeType.REGULAR, EdgeDirection.BACKWARD);
        setPred.remove(head);
        if (setPred.contains(stat)) {
          return false;
        }

        if (!setDest.containsAll(setPred) || setPred.size() > 1) {
          if (post == null) {
            post = stat;
            repeat = true;
            break;
          }
          else {
            return false;
          }
        }
        else if (setPred.size() == 1) {
          Statement pred = setPred.iterator().next();
          while (lst.contains(pred)) {
            Set<Statement> setPredTemp = pred.getNeighboursSet(EdgeType.REGULAR, EdgeDirection.BACKWARD);
            setPredTemp.remove(head);

            if (!setPredTemp.isEmpty()) { // at most 1 predecessor
              pred = setPredTemp.iterator().next();
              if (pred == stat) {
                return false;  // loop found
              }
            }
            else {
              break;
            }
          }
        }

        // succs
        List<StatEdge> lstEdges = stat.getSuccessorEdges(EdgeType.DIRECT_ALL);
        if (lstEdges.size() > 1) {
          Set<Statement> setSucc = stat.getNeighboursSet(EdgeType.DIRECT_ALL, EdgeDirection.FORWARD);
          setSucc.retainAll(setDest);

          if (!setSucc.isEmpty()) {
            return false;
          }
          else {
            if (post == null) {
              post = stat;
              repeat = true;
              break;
            }
            else {
              return false;
            }
          }
        }
        else if (lstEdges.size() == 1) {

          StatEdge edge = lstEdges.get(0);
          if (edge.getType() == EdgeType.REGULAR) {
            Statement statd = edge.getDestination();
            if (head == statd) {
              return false;
            }
            if (post != statd && !setDest.contains(statd)) {
              if (post != null) {
                return false;
              }
              else {
                Set<Statement> set = statd.getNeighboursSet(EdgeType.REGULAR, EdgeDirection.BACKWARD);
                if (set.size() > 1) {
                  post = statd;
                  repeat = true;
                  break;
                }
                else {
                  return false;
                }
              }
            }
          }
        }

        lst.add(stat);
      }

      if (!repeat) {
        break;
      }
    }

    lst.add(head);
    lst.remove(post);

    lst.add(0, post);

    return true;
  }