Unlock the Power of Debugging in Rust with GDB

What is GDB?

GDB is a command-line debugger that supports multiple languages, including C, C++, Go, and Rust. It’s a versatile tool that allows you to set breakpoints, inspect variables, and step through your code line by line. GDB is available on Linux, macOS, and Windows, and it’s often pre-installed on many Linux distributions.

Setting up GDB in Rust

To get started with GDB in Rust, you’ll need a recent version of Rust (1.39+) and GDB (8.x+). You’ll also need to ensure that the rust-gdb executable is in the same folder as your rustc executable. If you’re using Rustup, this should be the case by default.

Creating a Rust Project

Let’s create a new Rust project and add the necessary dependencies to our Cargo.toml file. We’ll use Tokio as a dependency to demonstrate how to debug async functions.

[package]
name = "debugging_example"
version = "0.1.0"
edition = "2018"

[dependencies]
tokio = { version = "1", features = ["full"] }

Debugging with rust-gdb

Now that we have our project set up, let’s create an example program and run it with rust-gdb. We’ll set a breakpoint, run the program, and inspect the variables using GDB’s info command.

fn main() {
    let x = 5;
    println!("Hello, world!");
}

$ rust-gdb target/debug/debugging_example
(gdb) break main
(gdb) run
(gdb) info locals

Inspecting State and Watchpoints

In this section, we’ll explore how to manipulate state and set watchpoints using GDB. We’ll create another example program that demonstrates how to set a watchpoint on a variable and inspect its value.

fn main() {
    let mut x = 5;
    x += 1;
    println!("x = {}", x);
}

(gdb) watch x
(gdb) run
(gdb) info watchpoints

Debugging an Async Network Application

Finally, we’ll show how to debug an async network application using GDB. We’ll create a simple TCP listener using Tokio and set a breakpoint in the process function. We’ll then send data to the endpoint using netcat and inspect the socket variable.

use tokio::prelude::*;
use tokio::net::TcpListener;

async fn process(socket: TcpStream) {
    //...
}

#[tokio::main]
async fn main() {
    let listener = TcpListener::bind("127.0.0.1:8080").await.unwrap();
    listener.accept().await.unwrap();
}

$ rust-gdb target/debug/debugging_example
(gdb) break process
(gdb) run
(gdb) info locals

$ nc localhost 8080
Hello, world!

Taking Your Debugging to the Next Level

If you’re interested in monitoring and tracking the performance of your Rust apps, consider using a robust debugging tool that provides full visibility into web frontends for Rust apps, allowing you to debug issues that are hard to reproduce.