The C Standard defines octal constants as a 0 followed by octal digits (0 1 2 3 4 5 6 7). Programming errors can occur when decimal values are mistakenly specified as octal constants.
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Although it may appear that i_array[2] is assigned the decimal value 42, it is actually assigned the decimal value 34.
Compliant
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Solution
To avoid using wrong values and to make the code more readable, do not preface constants with zeroes if the value is meant to be decimal:
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Misrepresenting decimal values as octal can lead to incorrect comparisons and assignments.
Rule | Severity | Likelihood | Remediation Cost | Priority | Level |
|---|---|---|---|---|---|
DCL18-C |
Low |
Unlikely |
Low | P3 | L3 |
Automated Detection
Tool | Version | Checker | Description | ||||||
| Astrée |
| octal-constant | Fully checked | ||||||
| Axivion Bauhaus Suite |
| CertC-DCL18 | |||||||
| CodeSonar |
| LANG.TYPE.OC | Octal constant | ||||||
| Helix QAC |
| C0339, C1272 | |||||||
| Klocwork |
| MISRA.TOKEN.OCTAL.ESCAPE MISRA.TOKEN.OCTAL.INT | |||||||
| LDRA tool suite |
| 83 S | Fully Implemented | ||||||
| Parasoft C/C++test |
| CERT_C-DCL18-a | Octal and hexadecimal escape sequences shall be terminated | ||||||
| PC-lint Plus |
| 9001 | Fully supported | ||||||
| Polyspace Bug Finder |
| CERT C: Rec. DCL18-C | Checks for use of octal constants (rec. fully covered) | ||||||
| PVS-Studio |
| V536 | |||||||
| RuleChecker |
| octal-constant | Fully checked | ||||||
| SonarQube C/C++ Plugin |
| OctalConstantAndSequence |
Related Guidelines
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