Homework

Please do not share your code or copy code from other students. Once you've read through this, feel free to delete it, though you may want to keep the formatting and linting sections as reference.

Contents

You might have noticed a couple extra files lying around this repository. Here's a rundown of what they do:

• .clang-format provides some settings for clang-format, which is a tool you can use to automatically reformat your code. You can read more about code style and formatting on the wiki, and the cheat sheet is below. Feel free to page through the configuration file if you're interested in how it works.
• .clang-tidy provides settings for clang-tidy, which does semantic checks on C++ files. We've included instructions on how to use this tool below as well.
• .editorconfig gives most IDEs some idea about how to handle whitespace in your code files. It also limits the charset to utf8 to avoid any encoding bugs.
• .gitignore prevents files from being added to the index by git. Make sure you use this to avoid pushing things like compiled binaries and test files to keep your repository slim and ensure that graders can easily pick out what they need to grade. You can add a .gitignore file in any of this repository's subdirectories to add rules relative to that path.

Formatting

clang-format is a utility built on top of the clang tooling that, among other things, visually restructures code based on a set of style guidelines. Based on a collection of settings that may be specified in a .clang-format file, it manages things like spacing, newlines, brackets, and indentation. We have already put a .clang-format file in your homework repository, so any files in or under the root directory will be formatted our ruleset.

You can invoke clang-format from the command line, and it comes installed out of the box on our Docker container. Running the utility within your homework repository is as easy as:

clang-format -i directory/file.cpp

If you want to format multiple files in a directory, you can use wildcard operators:

# Format all .cpp files in directory/
clang-format -i directory/*.cpp

# Format all .cpp and .h/.hpp files in directory/ 
clang-format -i directory/*.{h,hpp,cpp}

Lastly, you can use the double asterisk to recursively glob. This is necessary when you also want to format files in subdirectories.

# Format all .cpp and .h/.hpp files in directory/ and subdirectories
clang-format -i directory/**/*.{h,hpp,cpp}

Linting

clang-tidy is another tool for analyzing and fixing your code, but instead of focusing on syntax, it deals with semantics. In short, clang-tidy provides additional insights into your code. For example, it can warn you about unsafe memory management, point out unused variables, and suggest more modern approaches for certain snippets. Much like clang-format, you can invoke clang-tidy from the command line. We recommend you use it one file at a time so that the output is more digestible:

# Get warnings about a single file
clang-tidy directory/file.cpp --

# You can add arguments you'd pass to g++ after the --
clang-tidy directory/file.cpp -- -I included/

Unlike clang-format, we don't require you to use clang-tidy. Instead, we just offer it as a way for you to help debug your work. Oftentimes, you'll find that heeding the warnings from clang-tidy will save you from bugs before you even find them.

Another tool you can use in this vein is cppcheck. You can invoke cppcheck fairly similarly:

# Check file.cpp
cppcheck --enable=all directory/file.cpp

# Specify include directories as well
cppcheck --enable=all directory/file.cpp -I included/