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| Code Block | ||||
|---|---|---|---|---|
| ||||
int value;
if (scanf("%d", &value) == 1) {
if (value % 2 != 0) {
/* Take action if value is odd */
}
}
|
Compliant Solution
Using bitwise operators is safe on unsigned integers:
| Code Block | ||||
|---|---|---|---|---|
| ||||
unsigned int value;
if (scanf("%u", &value) == 1) {
if (value & 0x1 != 0) {
/* Take action if value is odd */
}
}
|
Risk Assessment
Incorrect assumptions about integer representation can lead to execution of unintended code branches and other unexpected behavior.
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Tool | Version | Checker | Description | ||||||||||||
| Astrée |
| bitop-type | Partially checked | ||||||||||||
| Helix QAC |
| C2940, C2945 DF2941, DF2942, DF2943, DF2946, DF2947, DF2948 | |||||||||||||
| LDRA tool suite |
| 50 S, 120 S | Partially Implemented | ||||||||||||
| Parasoft C/C++test |
| CODSTA-63 | Implemented | PRQA QA-C | |||||||||||
| Include Page | PRQA QA-C_v | PRQA QA-C_v | CERT_C-INT16-a | Bitwise operators shall only be applied to operands of unsigned underlying type | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PC-lint Plus |
| 502, 2704, 9088 | Partially supported: reports bitwise not of signed quantity, declaration of named signed single-bit bitfields, and negation of the minimum negative integer | ||||||||||||
| RuleChecker |
| bitop-type | Partially checked | 2940, 2941, 2942, 2943, 2945, 2946, 2947, 2948
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