Do not use a semicolon on the same line as an if, for, or while statement because it typically indicates programmer error and can result in unexpected behavior.
Noncompliant Code Example
In this noncompliant code example, a semicolon is used on the same line as an if statement:
if (a == b); {
/* ... */
}
Compliant Solution
It is likely, in this example, that the semicolon was accidentally inserted:
if (a == b) {
/* ... */
}
Risk Assessment
Errors of omission can result in unintended program flow.
Recommendation | Severity | Likelihood | Remediation Cost | Priority | Level |
|---|---|---|---|---|---|
EXP15-C | High | Likely | Low | P27 | L1 |
Automated Detection
Tool | Version | Checker | Description |
|---|---|---|---|
| Astrée | 24.04 | empty-body | Fully checked |
| Axivion Bauhaus Suite | 7.2.0 | CertC-EXP15 | Fully implemented |
| CodeSonar | 9.1p0 | LANG.STRUCT.EBS | Empty branch statement |
| Helix QAC | 2025.2 | C3109 | |
| Klocwork | 2025.2 | SEMICOL | |
| LDRA tool suite | 9.7.1 | 11 S, 12 S, 428 S | Fully Implemented |
| Parasoft C/C++test | 2024.2 | CERT_C-EXP15-a | Suspicious use of semicolon |
| PC-lint Plus | 1.4 | 721, 722 | Partially supported: reports missing body from if, for, or while with semi-colon immediately following predicate |
| Polyspace Bug Finder | R2025b | CERT C: Rec. EXP15-C | Checks for semicolon on same line as for, if or while statement (rule fully covered) |
| PVS-Studio | 7.39 | V529, V715 | |
| SonarQube C/C++ Plugin | 3.11 | S1116 | |
| RuleChecker | 24.04 | empty-body | Fully checked |
Related Guidelines
| SEI CERT Oracle Coding Standard for Java | MSC51-J. Do not place a semicolon immediately following an if, for, or while condition |
| ISO/IEC TR 24772:2013 | Likely Incorrect Expression [KOA] |
| MITRE CWE | CWE-480, Use of incorrect operator |
Bibliography
| [Hatton 1995] | Section 2.7.2, "Errors of Omission and Addition" |
