Tools for Working in a Large Codebase

Taking notes

At risk of seeming low-tech, using code tags such as TODO, XXX, and FIXME (or even your cs login) with helpful notes about what you were thinking when you noticed something was broken or unfinished will be incredibly useful. This also allows you to search for remaining tasks by using grep (or, if you’re using Git) git grep.

Even simpler than that, taking notes about the code you’re developing or drawing call trees to visualize the expected call stacks can be incredibly helpful for learning your way around a new codebase.

Text Editors and IDEs

Because the fights between text editors are near-religious in severity, we won’t recommend a particular code editor here, but we do recommend that you find a “serious” text editor with some built-in niceness to work in while you code. These include Vim and Emacs (which typically run at the command line and can run commands without leaving the editor), VSCode, and CLion. (Many TAs have used VSCode in the past and can offer tips and suggestions for how to navigate the Weenix codebase, please reach out to your mentor if you would like any pointers on how to use VSCode most effectively.)

Integration with cscope

Basically every major text editor has a cscope extension or bundle which allows you to do forward (“Where is this function defined?”) and reverse (“Where is this function called?”) searches, automatic text completion for function and variable names, etc. If you choose to use a text editor without these functions built-in, we highly recommend using cscope to make your job easier. Note that there is a cscope build target which will automatically update the cscope index every time you recompile (or you can also re-run it manually), so you just need to set up your editor to use the generated index file.

To learn how to use Cscope, we recommend reading this (short) guide. There are also (even shorter) guides on how to use Cscope in Vim, Emacs, and Sublime Text.

Debugging with gdb

If you have never used a debugger before, we highly recommend you learn to use one, either through a graphical interface like the one in many IDEs, or from the command line. This will be a development tool you will not want to live without once you learn to use it.

gdb is the most widely used debugger for C code, with support for kernel development using many virtual machines. There are many wonderful reasons to use gdb to debug Weenix in particular, so please read the appendix on debugging for more information.