Identify Incorrect Return Value Handling
- Review the function definitions and their respective return types. Ensure all functions where return values are critical for subsequent operations are correctly identified.
- Compile with warnings enabled (e.g., `-Wall` and `-Wextra` in GCC) to detect mismatches and ignored return values.
- Use static analysis tools to flag unhandled return values, especially common in libraries like POSIX, where functions often return success/failure indicators.
Design Error Handling Strategies
- Define a clear error-handling strategy for each function. For example, how to handle return values signaling errors or exceptions that require breaking from the normal control flow.
- Develop a consistent return value system (e.g., returning error codes or using `errno`) if not pre-defined, to improve code readability and maintainability.
Implement Correct Return Value Assignments
Check and Propagate Errors Appropriately
Implement Unit Tests for Code Paths
- Create unit tests that exercise both normal and error path code. This ensures that return value handling covers all scenarios and increases code robustness.
- Use mock functions or stubs to simulate error conditions and validate how the firmware responds when functions return unexpected values.
Review and Refactor
- Regularly review and refactor the code to handle return values more efficiently, especially after updates or integration of new modules.
- Document any non-obvious decisions taken due to complex return value handling strategies for future reference and for new team members.
Continuous Monitoring and Logging
- Implement logging to capture return values and errors during runtime to provide insight into unexpected issues or trends over time.
- Regularly monitor logs to detect patterns or frequent errors to address them proactively within the codebase.