Debuggers

A debugger is a software tool that helps programmers identify and fix defects by controlling a program's execution and examining its state. It enables running code under instrumentation, pausing at specific points, inspecting variables, and resuming or altering execution. Debuggers aim for correctness rather than performance measurement.

Debuggers range from source-level debuggers integrated with IDEs to machine-level tools that operate on assembly. Remote and distributed debuggers enable debugging across processes or devices, while post-mortem debuggers analyze crash dumps after a failure. Memory debuggers help detect invalid access, leaks, and resource misuse.

Common features include breakpoints (including conditional ones), stepping controls (step in, step over, step out), watches or expressions, and views of local and global variables, call stacks, and memory or register contents. Many provide disassembly, logging, and scripting; some offer time-travel debugging to replay a recent execution.

Usage typically involves starting or attaching to a program, hitting breakpoints, inspecting and modifying state, and continuing execution. Debugging concurrent or asynchronous code adds complexity and may require multiple breakpoints and thread views. Limitations include overhead that alters timing, reduced visibility in optimized builds, and nondeterministic bugs.

Modern debuggers are often part of integrated development environments (IDEs) and support remote debugging, multi-language workflows, and integration with testing and CI tools.