blog/cpp/environment.md

title	description	last_update
Environment	Suggestions for setting up a local environment for C++ course.	date 2023-02-18

Required tools per OS

Windows

Most likely WSL, VM or VPS. If you consider setting up either of those PITA, then VSCode + SSH to aisa might be the best option for you.

:::warning VSCode @ aisa

Be careful when using VSCode on aisa, most notably:

1. VSCode can leave lingering processes running in the background that can „eat up“ your quota for running processes. AFAIK UNIX team has implemented some periodic clean up of those.
2. Disk quota can be also affected, because of the C/C++ extension toolkit that has a cache for IntelliSense.

:::

Either of those will be linux distros, so jump to next section.

Linux

Majority (if not all) of the provided materials include makefile (contains absolute path, so in case of linting and compiling, you need to adjust to your needs). You basically need following list of tools:

• gcc - for compiling
• clang-tidy - for linting (depends on distribution, might be provided with clang itself or in separate package, e.g. clang-tools-extra)
• clang-format - for your own sanity of keeping consistent formatting
• make - since you are provided makefiles and it might be quickest to set up
• valgrind - in case you manage to create memory errors in your code

In case of Fedora it is following set of packages:

sudo dnf install -y clang clang-tools-extra valgrind gcc make
# If you decide to use google test: add `gtest` or `llvm-googletest` for clang

macOS

In case of macOS you should be able to find all of the packages in brew.sh, except valgrind, not sure if you can solve with podman/docker.

There is also an alterantive to homebrew, that is nixpkgs.

nix(OS)

In case you run nixOS or linux distribution with nixpkgs or you use nixpkgs as a replacement for homebrew on macOS. You should be fine with the following config:

with import <nixpkgs> {};
stdenv.mkDerivation {
  name = "cppenv";
  buildInputs = [
    clang-tools

    gnumake

    gmock # used for google test
    valgrind # not sure about macOS though
  ];
}

IDEs

Choice of the IDE is mostly up to you, you do not need to use IDE at all ;)

I would probably recommend VSCode + appropriate extension or CLion if you are used to the JetBrains IDEs.

git

I recommend you using some basic versioning for your code, even though you submit only the sources on aisa. There are specific reasons why I suggest it:

• if you build a commit, tag and submit habit, you might be able to address some of the smaller problems in your sources even before submission; more info in the pre-commit section

In case you are planning to use git branches for separating different assignments and/or merge requests I suggest you to keep specifications and skeletons on your default branch, since frag on aisa automatically downloads everything that is not present and by that can create conflicts when switching branches.

:::tip Commit conventions

When creating smaller and well defined commits, you can more easily argue about correctness of your implementation and also identify bugs, since they are better contained.

:::

Since frag creates a lot of support files (majority of them are dotfiles, i.e. hidden files), I recommend you to use following gitignore configuration that should cover most of the scenarios.

pre-commit (link)

Pre-commit basically allows you to "check" your code before committing. It functions as a git hook, i.e. you want to make a commit, pre-commit checks it before-hand.

In case of C++ there are few use-cases:

• formatting

• linting

• building and/or running tests, in case you feel like masochist

  However this might be a challenging task to implement, since most of the tasks are published from the beginning.

In case of formatting and linting, there are already existing hooks (there is a list of supported ones on the page), but there is also an option for you setting it up yourself (it is just a matter of specifying command and files it should run on).

:::tip Formatting

For formatting you can the following git hook.

This hook follows the formatting conventions defined by the .clang-format file that is looked up recursively all the way to the root of the filesystem, therefore it is ideal to keep it in the root of the git repository.

You can look up the different codestyles here.

:::

Testing

I have tried 2 frameworks for testing, one of them will be probably showcased in lectures. If you have not picked one yet, you can take an inspiration from the following.

catch2

It is quite popular, only one header-file, also might be easier to set up.

Might feel slow to compile, this can be addressed by having one object file with precompiled main for tests, e.g.

/* File: catch_main.cpp
 * Compile it with: g++ $(CXXFLAGS) -c catch_main.cpp
 *
 * Once you have source file with tests, e.g. test_something.cpp, compile it in
 * a similar fashion: g++ $(CXXFLAGS) -c test_something.cpp $(LDLIBS)
 *
 * And link them together:
 * g++ catch_main.o test_something.o -o test_something
 *
 * Now you can run ./test_something and if you change it, you do not need to compile
 * the main again.
 */
#define CATCH_CONFIG_MAIN
#include "catch.hpp"

Google Test

It is faster compared to catch2, even if you do not precompile the main. Might be more complicated to set up, since there are multiple files (it is not one header file). Not very user friendly on aisa. However can be installed through package manager.