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When using long identifiers, try to make the initial portions of the identifiers unique for easier recognition. This also helps prevent errors resulting from non-unique identifiers (see DCL32-C. Guarantee that mutually visible identifiers are unique).
Risk Analysis
Failing to use visually distinct identifiers can result in the wrong variable being used, causing unexpected program behavior.
Recommendation | Severity | Likelihood | Remediation Cost | Priority | Level |
|---|---|---|---|---|---|
DCL02-A C | low | unlikely | medium | P2 | L3 |
Automated Detection
Compass/ROSE could detect violations of this rule merely by making a set of identifies for each scope. Then for each variable, it converts 'l' (ell) to '1' (one), converts '0' (capital o) to '0' (zero), and does the other conversions listed above, and then checks for collisions.
Related Vulnerabilities
Search for vulnerabilities resulting from the violation of this rule on the CERT website.
References
| Wiki Markup |
|---|
\[[ISO/IEC 9899:1999|AA. C References#ISO/IEC 9899-1999]\] Section 5.2.4.1, "Translation limits" \[[ISO/IEC PDTR 24772|AA. C References#ISO/IEC PDTR 24772]\] "AJN Choice of Filenames and other External Identifiers," "BRS Leveraging human experience," and "NAI Choice of Clear Names" \[[MISRA 04|AA. C References#MISRA 04]\] Rule 5.6 |
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02. Declarations and Initialization (DCL) DCL03-A. Use a static assertion to test the value of a constant expression