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Noncompliant Code Example (Non-Prototype-Format Declarators)
Noncompliant This noncompliant code example uses the identifier-list form for parameter declarations:
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In this noncompliant code example, the function pointer fn_ptr refers to the function add(), which accepts three integer arguments. However, fn_ptr is specified to accept two integer arguments. Setting fn_ptr to refer to add() results in unexpected program behavior. This example also violates DCL35violates EXP37-C. Call functions with the correct number and type of arguments.:
| Code Block | ||||
|---|---|---|---|---|
| ||||
int add(int x, int y, int z) {
return x + y + z;
}
int main(int argc, char *argv[]) {
int (*fn_ptr) (int, int);
int res;
fn_ptr = add;
res = fn_ptr(2, 3); /* Incorrect */
/* ... */
return 0;
}
|
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Failing to include type information for function declarators can result in unexpected or unintended program behavior.
Recommendation | Severity | Likelihood | Remediation Cost | Priority | Level |
|---|---|---|---|---|---|
DCL07-C | Low | Unlikely | Low | P3 | L3 |
Automated Detection
Tool | Version | Checker | Description | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Astrée |
| function-prototype implicit-function-declaration | Partially checked | ||||||
| Axivion Bauhaus Suite |
| CertC-DCL07 | |||||||
| CodeSonar |
| LANG.FUNCS.PROT LANG.STRUCT.DECL.IMPT | Incomplete function prototype Implicit Type | ||||||
| CC2.DCL07 | Fully implemented | |||||||
| GCC |
|
Can detect violation of this recommendation when the | |||||||||
| Helix QAC |
| C1304, C2050, C3331, C3335, C3408, C3450 | |||||||
| Klocwork |
| MISRA.FUNC.PROT_FORM.KR.2012 MISRA.FUNC.NOPROT.DEF MISRA.CAST.FUNC_PTR.2012 | |||||||
| LDRA tool suite |
| 21 S | Fully implemented |
3335
3450
0563
2050
| PC-lint Plus |
| 718, 746, 936, 9074 | Fully supported | ||||||
| Polyspace Bug Finder |
| Checks for:
Rec. fully covered. | |||||||
| RuleChecker |
| function-prototype implicit-function-declaration | Partially checked | ||||||
| SonarQube C/C++ Plugin |
| S819, S930 |
Related Vulnerabilities
Search for vulnerabilities resulting from the violation of this rule on the CERT website.
Related Guidelines
| ISO/IEC TR 24772:2013 | Type System [IHN] Subprogram Signature Mismatch [OTR] |
| ISO/IEC TS 17961 | Using a tainted value as an argument to an unprototyped function pointer [taintnoproto] |
| MISRA C:2012 | Rule 8. |
2 (required) |
Bibliography
| [ISO/IEC 9899:2011] | Subclause 6.11.7, "Function Definitions" |
| [Spinellis 2006] | Section 2.6.1, "Incorrect Routine or Arguments" |
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