This extension allows you to search the Firefox codebase using the awesome bar.
To test it out, type 'cs' into the awesome bar followed by a search string (e.g. cs hello world). The results will be shown as suggestions, and clicking on a suggestion will navigate to the file where the result was found.
To search a specific file, use the "path:" prefix (e.g. cs hello path:omnibox.js)
How to use the omnibox API to add custom suggestions to the awesome bar.