Using a debugger

How to:

C++ integrates with debuggers like GDB or the Visual Studio debugger. Here’s a bitesize example using GDB:

#include <iostream>

int main() {
    int a = 5;
    int b = 0;
    int c = a / b; // Oops, division by zero!
    std::cout << c << std::endl;
    return 0;

// Compile with:
// g++ -g -o my_program my_program.cpp

// Run with debugger:
// gdb ./my_program

Once you’ve started GDB, you can set breakpoints, step through your code, inspect variables, and much more. If you run the above, you should see your program crash due to the division by zero.

Deep Dive

Debugging has its roots in the early days of programming, where literally removing bugs (insects!) from hardware was necessary. Since then, debugging tools have evolved into complex and powerful software, critical for development.

Alternatives to GDB for C++ include LLDB, as well as IDE-integrated debuggers like those in Visual Studio, CLion, or Eclipse. These modern environments provide graphical interfaces making debugging less intimidating.

Implementation details about using a debugger often depend on your development environment:

  • Command-line debuggers (GDB, LLDB) require familiarity with terminal commands and often involve a steeper learning curve.
  • Graphical debuggers simplify the process by allowing point-and-click interactions to set breakpoints, step through code, and watch variables.

Understanding your debugger’s capabilities, such as conditional breakpoints, watchpoints, or evaluating expressions, can significantly boost your efficiency in diagnosing problems.

See Also