Find your way around the code

Summary

• GitHub search
• Ripgrep
• IDEs
  • Qt Creator

Once you have successfully compiled MuseScore and found a task or issue you want to tackle, the next step is to find the relevant part of the code.

It's a good idea to search the source code for terms related to the issue. If the issue has screenshots with any UI text visible, try searching for that text; there's a good chance it's defined near the code you need to edit.

GitHub search

The search feature here on GitHub is a good place to start.

Example GitHub query	Searches for files that...
note input	Have the word "note" and the word "input" in the content or in the path.
"note input"	Have the exact string "note input" (without quotes) in the content or in the path.
content:/note ?(input|entry)/	Contain the exact string "note input", "noteinput", "note entry", or "noteentry".
content:/"note-[a-g]"/	Contain the exact string "note-a", or "note-b", or ... "note-g" (with quotes this time).
path:score language:cpp	Are C++ files (including headers) with "score" somewhere in the path.
path:score path:.cpp	Have "score" and ".cpp" somewhere in the path.
content:score NOT path:/\.cpp$/	Contain "score" but the path does not end in ".cpp".
symbol:rest	Use "rest" in the name of a code symbol (i.e. a variable, function, or class).

See GitHub search syntax for more details, or use advanced search. Remember to restrict it to repo:musescore/MuseScore.

GitHub only searches the default branch (i.e. master). If you want to search other branches (e.g. 4.2.0 or 3.x) then you need to use offline search instead.

Ripgrep

The command line utility ripgrep (rg) is like Unix grep but faster and more powerful. It enables you to search for strings and regular expressions in lots of files very quickly. By default, ripgrep ignores binary files and files that are ignored by Git, such as those in the builds directory created by build.cmake.

Here's an example of how to use ripgrep:

rg -i "note.?input"

This performs a case-insensitive search for the regular expression note.?input in all files in the repository.

This would match all occurrences of:

• note input
• Note Input
• noteInput
• NOTE_INPUT
• note-input
• etc.

Useful options for ripgrep:

Argument	Action
-F, --fixed-strings	Search for a fixed string instead of a regular expression (e.g. -F "Note input").
-i, --ignore-case	Perform a case-insensitive search.
-C[num], --context=[num]	Show this many lines of context before (-B[num]) and after (-A[num]) the matching line.
-l, --files-with-matches	List names of matching files but don't show the matching lines.
-v, --invert-match	Show lines/files that do not match the given pattern.
[path]	Restrict the search to a single file or directory tree (e.g. src/).

Install ripgrep using the command for your package manager. See rg --help for more options.

IDEs

IDEs often have useful shortcuts to make it easier to navigate code.

Qt Creator

Switch between source and header files

Press F4 in any .cpp file to be taken to the corresponding .h file, if there is one, and vice versa.

Follow symbol under cursor

Click on the name of any symbol (variable, function, class, etc.) and press F2 to be taken to where the symbol is declared/defined.

Find references to symbol under cursor

Right-click on the name of any symbol and choose this option to see a list of other places the symbol occurs (basically an intelligent search facility).