From: Dan Carpenter <dan.carpenter@oracle.com>
To: Harshvardhan Jha <harshvardhan.jha@oracle.com>
Cc: smatch@vger.kernel.org
Subject: Re: [PATCH 2/2] extra: Fix handle_bit_test so that null set condition is taken care of
Date: Tue, 13 Jul 2021 18:35:28 +0300 [thread overview]
Message-ID: <20210713153527.GS1954@kadam> (raw)
In-Reply-To: <20210713125006.12329-2-harshvardhan.jha@oracle.com>
I have applied the first commit but this one still needs work. Consider
this test case:
#include "check_debug.h"
unsigned int frob();
void test(void)
{
unsigned int mask = 0xff0;
unsigned int x = frob();
if (frob())
mask |= 0x2;
if (x < 0 || x > 11)
return;
if ((1 << x) & mask) {
__smatch_implied(x);
return;
}
__smatch_implied(x);
}
The output is:
test.c:17 test() implied: x = '1-11'
test.c:20 test() implied: x = '0'
The first implied is correct but the second is wrong. BIT(1) or 0x2 is
*possibly* set or *possibly not* set. So on the false path the range
list should be 0-1.
regards,
dan carpenter
next prev parent reply other threads:[~2021-07-13 15:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 12:50 [PATCH 1/2] extra: Fix false output of handle_AND_op and handle_AND_condition Harshvardhan Jha
2021-07-13 12:50 ` [PATCH 2/2] extra: Fix handle_bit_test so that null set condition is taken care of Harshvardhan Jha
2021-07-13 15:35 ` Dan Carpenter [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-07-13 18:05 Harshvardhan Jha
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