StackKnack

Call stack visualization app written in clojure.

Hosted here: http://3.148.228.98:3000/

Very much WIP/proof of concept

Clojure utilization

Our project uses Clojure to create an interactive visualization tool that allows users to write, compile, and step through C programs directly within their browser. It takes advantage of Clojure’s strong interoperability with system processes to communicate with compilers and debuggers like gcc and lldb in real time, althought this did prove somewhat difficult to implement for the stepping feature. By leveraging functional programming and lightweight concurrency, we have the server live stepping and variable tracking efficiently. This usage of Clojure shows how a non-traditional language like Clojure can bridge systems-level programming with interactive web-based visualization.

AWS Info

Setting up Ubuntu on our AWS EC2 instance: https://linux.how2shout.com/how-to-install-docker-on-aws-ec2-ubuntu-22-04-or-20-04-linux/

Setting up clojure on cloud: https://clojure.org/guides/install_clojure

Also installed gcc, java jre (https://ubuntu.com/tutorials/install-jre#2-installing-openjdk-jre), gdb (which prob isn't required)

Persistance

Create a service file:

sudo nano /etc/systemd/system/stackknack.service

[Unit]
Description=StackKnack Clojure Web App
After=network.target

[Service]
# Adjust this to the user running your app (usually ec2-user or ubuntu)
User=ec2-user
WorkingDirectory=/home/ec2-user/stackknack

# Start command (use full paths)
ExecStart=/usr/local/bin/clojure -M -m stackknack.server public

# Optional: set environment variables (like PORT)
Environment=PORT=3000

# Restart automatically if crashed
Restart=always
RestartSec=5

# Log output to a file
StandardOutput=append:/home/ec2-user/stackknack/server.log
StandardError=append:/home/ec2-user/stackknack/server.err

# Give it enough open files
LimitNOFILE=65535

[Install]
WantedBy=multi-user.target

Reload and enable:

sudo systemctl daemon-reload
sudo systemctl enable stackknack.service
sudo systemctl start stackknack.service

Verify it's running:

sudo systemctl status stackknack.service

If code is ever updated:

sudo systemctl restart stackknack.service

TODO

• Dockerize the user code (oops)
• Add reset button
• Don't refresh assembly for every step
• Lable local vars + params (registers?) correctly
• Move registers text block around (only show relevant ones?)