import cpp

class IndexLoopStmt extends ForStmt {
  IndexLoopStmt() {
    isIndexLoop(this)
  }

  Variable index() {
    result = this.getInitialization().(DeclStmt).getDeclaration(0).(Variable)
  }

  Expr bound() {
    result = this.getCondition().(LTExpr).getRightOperand()
  }
}

predicate isIndexInit(Variable v) {
  v.getInitializer().getExpr() instanceof Literal
}

predicate isIndexCond(ForStmt loop, Variable v) {
  loop.getCondition().(LTExpr).getLeftOperand().toString() = v.toString()
}

predicate isIndexInc(ForStmt loop, Variable v) {
  loop.getUpdate().(IncrementOperation).getOperand().toString() = v.toString()
}

predicate isIndexLoop(ForStmt loop) {
  exists(Variable v |
    v = loop.getInitialization().(DeclStmt).getDeclaration(0).(Variable) |
    isIndexInit(v) and isIndexCond(loop, v) and isIndexInc(loop, v)
  )
}

from IndexLoopStmt loop
where loop.bound().getNumChild() = 0
select loop, loop.index(), loop.bound()