C2 Aims to Modernize the C Language

C2 is a new programming language aiming to be an evolution of C that is suitable for low-level programs like bootloaders, kernels, drivers, and system-level tooling.

C2’s mission statement is keeping the good parts of C while changing those parts that betray it being a 40-year old language, says its creator Bas van den Berg. Undesirable aspects of C include the use of header files, which greatly slow the compiler down, and complex type declaration syntax, which C2 replaces with a module system and its uniform type syntax. C2 also introduces an integrated build system supporting full link-time optimization (LTO), while a macro system is in the works.

This is how a prototypical "hello world" program looks like in C2, showcasing modules and imports, and the type system:

module hello_world;

import stdio as io;

func i32 main(i32 argc, char*[] argv) {
    io.printf("Hello World!\n");
    return 0;
}

C2 does not aim to add higher-level features such as OO-support and garbage collection.

InfoQ has spoken with Bas van den Berg, creator of the language.

InfoQ: What are the main goals of C2?

Bas van den Berg: I’ve been working with C for almost 20 years now. In that time I’ve used it to write/ modify drivers, low-level/high-performance applications, real-time systems, etc. So stuff you typically use C for. I really like C, but some things are showing their age. Since I don’t see any other languages invading that part of the C-domain (e.g., low-level, kernels etc.) and I didn’t want to spend another 20 years solving the same issues again and again, I started C2. So the main goal of C2 is to solve the common issues with C and improve the developer experience.

InfoQ: Do you envision the possibility for existing C code bases to be migrated to C2? Would that provide some advantage?

van den Berg: Since C programs almost never work stand-alone but use other (C) libraries, the same goes for C2. So C2 programs need to be able to easily use C libraries and also C libraries need to be able to integrate with C2 libraries as well. As a demo I’ve ‘ported’ the Lua and Vulkan interfaces within a few days to C2. There is a demo implementation in the c2_examples that show how this works. What I personally do to get a feel for C2 is to port programs in C to C2 to see if there are any nasty issues. If there are, these are fixed in C2. This way the syntax evolves. The advantage of porting a current C program would be easier access to full program optimization, much faster compile times.

InfoQ: What is the current maturity status of the language and its tooling? When do you foresee it could be production-ready?

van den Berg: In its current form, I wouldn’t advice using C2 for production code, but for smaller projects, it’s definitely usable. Since the syntax is not yet frozen, any update might however break your program.

Two areas where C2 will change is the addition of the macro subsystem (still in design) and the library subsystem will be expanded to allow source-libraries and a Cargo-like tool to manage external packages. I’m currently working on the library system and that should be gradually released in Q2 this year. The macro subsystem is planned after that.

According to van den Berg’s own experience, the use of C2 can speed up development by 30%. C2 is open source and can be installed on Linux, macOS, and Windows.