rdb: Rust Debugger

A source-level debugger for Linux x86_64 written in Rust, based on sdb.

Features

• Source-level debugging with accurate line information
• Function and line breakpoints
• Step into/over/out operations
• Inline frame support
• Syscall catching
• Register and memory inspection
• Disassembly view
• Process launch and attach

Quick Start

Build

cargo build --release

Launch a Program

./target/release/rdb ./your_program

Attach to Running Process

$ ./target/release/rdb -p <PID>

Usage

Commands

break (b)     - Set/manage breakpoints
cont (c)      - Continue execution
step (s)      - Step into functions
next (n)      - Step over functions
finish        - Step out of current function
stepi         - Step one instruction
reg           - Show/modify registers
mem           - Read/write memory
dis           - Disassemble instructions
catch         - Catch syscalls
watch         - Set watchpoints
help          - Show help

Setting Breakpoints

# Function breakpoint
rdb> break set main

# Line breakpoint
rdb> break set file.rs:15

# Address breakpoint
rdb> break set 0x401000

# List breakpoints
rdb> break list

Example Session

# Compile with debug info
$ rustc -g example.rs

# Launch debugger
$ ./target/release/rdb ./example

# Debug session
rdb> break set main
rdb> cont              # Continue to breakpoint
rdb> step              # Step into function
rdb> next              # Step over line
rdb> reg               # Show registers
rdb> finish            # Step out
rdb> cont              # Continue

Manual Testing

Compile the demo program:

rustc -g test_programs/demo.rs -o target/test_bins/demo

Launch and test:

./target/release/rdb target/test_bins/demo

# Basic workflow
rdb> break set calculate
rdb> cont                    # Stops at calculate function
rdb> step                    # Steps into add function
rdb> next                    # Steps over println
rdb> cont                    # Continues to exit

Test Scenarios

Function breakpoints:

rdb> break set add
rdb> break set multiply
rdb> cont                    # Hits add
rdb> cont                    # Hits multiply

Line breakpoints:

rdb> break set demo.rs:13
rdb> cont                    # Stops at line 13

Step operations:

rdb> break set main
rdb> cont
rdb> next                    # Step over (doesn't enter functions)
rdb> step                    # Step into (enters functions)
rdb> finish                  # Step out (returns from function)

Inspection:

rdb> break set calculate
rdb> cont
rdb> reg                     # Show registers
rdb> mem $rsp                # Show memory at stack pointer
rdb> dis                     # Disassemble current location

Testing

# Run all tests
cargo test

# Run with output
cargo test -- --nocapture

# Specific test
cargo test --test breakpoints

Requirements

• Linux x86_64
• Programs must be compiled with debug info (-g)

License

See LICENSE.txt

Credits

Based on sdb by TartanLlama, following the book "Building a Debugger" by Sy Brand.