Do not use the bitwise AND (&, ampersand) or bitwise OR (|, pipe) operator in a conditional expression because this typically indicates programmer error and can result in unexpected behavior. Use & or | only for bitwise operations and use && or || only for logical operations.
Noncompliant Code Example
In this noncompliant code example, a bitwise expression is used in a conditional expression.
if (!(getuid() & geteuid() == 0)) {
/* ... */
}
Compliant Solution
This compliant solution uses the && operator for the logical operation within the conditional expression.
if (!(getuid() && geteuid() == 0)) {
/* ... */
}
Automated Detection
Tool |
Version |
Checker |
Description |
|---|---|---|---|
| 2017.07 | CONSTANT_EXPRESSION_RESULT |
can detect the specific instance where bitwise operator is used in place of logical operator or vice versa. The behavior might be desirable in some situation, so further verification is necessary. |
Bibliography
[Hatton 1995] Section 2.7.2, "Errors of omission and addition"
[ISO/IEC PDTR 24772] "KOA Likely Incorrect Expressions"
[MITRE 2007] CWE ID 480
, "Use of Incorrect Operator"
03. Expressions (EXP) EXP18-C. Do not perform assignments in selection statements