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Date: Mon, 11 Nov 2019 23:21:15 +0000
From: John Levon <levon@movementarian.org>
Subject: check_signed.c false negative
Message-ID: <20191111232115.GA19963@movementarian.org>
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Given:

enum ib_qp_state {
        IB_QPS_RESET,
        IB_QPS_INIT,
        IB_QPS_RTR,
        IB_QPS_RTS,
        IB_QPS_SQD,
        IB_QPS_SQE,
        IB_QPS_ERR
};

int p(enum ib_qp_state cur_state, enum ib_qp_state next_state)
{
#if 0
       if (cur_state  < 0 || cur_state > IB_QPS_ERR ||
         next_state < 0 || next_state > IB_QPS_ERR) {
                return (5);
        }
#else
       if (next_state < 0 || next_state > IB_QPS_ERR) {
                return (5);
        }
#endif

        return (0);
}

current smatch is happy. But "#if 1" above instead, and:

jlevon@sent:~/src/smatch$ ./smatch a.c
./smatch: a.c:15 p() warn: unsigned 'cur_state' is never less than zero.

Why is "next_state" not reported equally?

thanks
john