protected void eliminateDeadCode(JilMethod method) {
HashMap<String, Integer> labels = new HashMap();
List<JilStmt> body = method.body();
Stack<Integer> worklist = new Stack();
HashSet<Integer> visited = new HashSet();
// first, initialiser label map
int pos = 0;
for (JilStmt s : body) {
if (s instanceof JilStmt.Label) {
JilStmt.Label lab = (JilStmt.Label) s;
labels.put(lab.label(), pos);
}
pos++;
}
worklist.push(0);
visited.add(0);
while (!worklist.isEmpty()) {
int idx = worklist.pop();
if (idx != body.size()) {
JilStmt stmt = body.get(idx);
addSuccessors(worklist, visited, labels, stmt, idx);
}
}
// Ok, now eliminate any dead statements (if there are any)
if (visited.size() <= body.size()) {
pos = 0;
int size = body.size();
for (int i = 0; i != size; ++i) {
if (!visited.contains(i)) {
body.remove(pos);
} else {
pos = pos + 1;
}
}
}
}
