Error handling and reporting are crucial aspects of software development in C++. Proper handling of errors ensures that programs are robust, maintainable, and provide meaningful feedback to users. In this blog post, we will discuss some guidelines for error handling and reporting in the context of C++ style guides.

1. Use Exceptions for Exceptional Conditions

Exceptions in C++ are a powerful mechanism for handling exceptional conditions. When an error occurs, use exceptions to signal the occurrence of an exceptional condition rather than relying on return codes or global error flags. Exceptions provide a clean and structured way to propagate errors up the call stack, making code more readable and maintainable.

void readFile(const std::string& filename)
{
    std::ifstream file(filename);
    if(!file)
    {
        throw std::runtime_error("Failed to open file: " + filename);
    }
    // Rest of the file reading logic
}

2. Provide Meaningful Error Messages

When throwing exceptions or reporting errors, it is essential to provide meaningful error messages that can help developers diagnose and fix the problem. Include relevant information about the error, such as the cause and context of the error, so that users and developers can quickly understand what went wrong.

void divideNumbers(int dividend, int divisor)
{
    if(divisor == 0)
    {
        throw std::runtime_error("Divide by zero error: dividend = " + std::to_string(dividend) + ", divisor = 0");
    }
    // Rest of the division logic
}

3. Handle Errors Locally when Possible

In some cases, it might be appropriate to handle errors locally rather than propagating them to higher levels. This approach is suitable when the error can be resolved or worked around without affecting the overall flow of the program. However, be cautious not to suppress important errors or hide the root cause of the problem.

void processFile(const std::string& filename)
{
    try
    {
        readFile(filename);
        // Rest of the file processing logic
    }
    catch(const std::exception& e)
    {
        std::cerr << "Error processing file: " << e.what() << std::endl;
        // Optionally, perform fallback logic or notify the user
    }
}

4. Consider Logging Errors

In addition to throwing exceptions or reporting errors directly to users, consider logging errors to aid with debugging and error analysis. Logging error information can help uncover patterns, identify recurring issues, and provide valuable insights for improving the software.

void doSomething()
{
    try
    {
        // Code logic
    }
    catch(const std::exception& e)
    {
        // Log the error for further analysis
        logError("An error occurred in doSomething(): " + std::string(e.what()));
        // Optionally, re-throw the exception for higher-level error handling
        throw;
    }
}

Conclusion

Proper error handling and reporting are essential for building reliable and robust software in C++. By following these guidelines, developers can ensure that their code behaves predictably when errors occur and provides meaningful feedback to users. Remember to use exceptions for exceptional conditions, provide informative error messages, handle errors locally when possible, and consider logging errors for analysis. By incorporating these practices into your C++ style guides, you can foster better error handling practices in your development team.