Reentrancy bugs in smart contracts caused a devastating financial loss in 2016, considered as one of the most severe vulnerabilities in smart contracts. Most of the existing general-purpose security tools for smart contracts have claimed to be able to detect reentrancy bugs. In this paper, we present Clairvoyance, a cross-function and cross-contract static analysis by identifying infeasible paths to detect reentrancy vulnerabilities in smart contracts. To reduce FPs, we have summarized five major path protective techniques (PPTs) to support fast yet precise path feasibility checking. We have implemented our approach and compared Clairvoyance with three state-of-the-art tools on 17770 real-worlds contracts. The results show that Clairvoyance yields the best detection accuracy among all the tools.