How Can I Identify the Exact Source of Unhandled Exceptions in C ?

Identifying the Exact Source of Unhandled Exceptions

In programming, exceptional situations often occur, triggering exceptions that disrupt the normal flow of execution. While it's generally straightforward to pinpoint the source of exceptions you intentionally generate, tracking down the origin of unhandled ones or those generated by external systems can be challenging.

One approach is to rely on the exception's built-in information, which may include a pointer to the line and source file responsible for the error. However, this information is not always available or reliable in all scenarios.

To address this limitation, consider utilizing a custom exception class that encapsulates both the original exception and the source information. This allows you to handle exceptions in a comprehensive and user-friendly manner, providing precise details about their origins.

Here's how to implement such a custom exception class:

#include <iostream>
#include <sstream>
#include <stdexcept>
#include <string>

class my_exception : public std::runtime_error {
    std::string msg;
public:
    my_exception(const std::string &arg, const char *file, int line) :
    std::runtime_error(arg) {
        std::ostringstream o;
        o << file << ":" << line << ": " << arg;
        msg = o.str();
    }
    ~my_exception() throw() {}
    const char *what() const throw() {
        return msg.c_str();
    }
};

Once your custom exception class is in place, you can utilize a macro to throw exceptions with source information:

#define throw_line(arg) throw my_exception(arg, __FILE__, __LINE__);

This macro can be used as follows:

void f() {
    throw_line("Oh no!");
}

When an exception is triggered using this macro, the my_exception class will automatically store the source information, including the file name and line number.

Now, let's demonstrate how to handle exceptions using this custom class:

int main() {
    try {
        f();
    }
    catch (const std::runtime_error &ex) {
        std::cout << ex.what() << std::endl;
    }
}

By utilizing the what() function of the custom exception class, you can obtain a detailed error message that includes the originating source information, enabling precise error diagnosis and resolution.

The above is the detailed content of How Can I Identify the Exact Source of Unhandled Exceptions in C ?. For more information, please follow other related articles on the PHP Chinese website!