Bask

The language is basically a subset of C. It is not particularly interesting syntactically but it was a fantastic project to learn how to write compilers, and how to use LLVM. The language is named after basking sharks. I don't know why, I just picked a shark at random. Naming things is hard and sharks are cool

I dont have any plans to continue working on this project beyond adding a bit more to the standard library and finalizing string support and some other stuff. I am happy with what I have learned from this project and I am looking forward to my next compiler project!

The language

The language is kind of like c. I like to use c syntax highlighting for it. The supported and tested features are:

• Declaration and assignment of integers, floats and boolean variables
• Declaration and definition of functions, and declaration of external functions which can be linked to later
• Arithmetic operations on integers and floats
• Comparison operations on integers and floats
• If statements
• function calls
• Recursion
• Including files, which acts like header files in c

Here are some example programs:

Here is a simple program that adds two numbers:

int main() {
    int a = 5;
    int b = 10;
    int c = a + b;
    return c;
}

Here is a program that calculates the factorial of 15:

use "io.bsk";

int no_body();

int factorial(int n) {
  if (n == 0) {
    return 1;
  }
  return n * factorial(n - 1);
}

int main() {
  put_int(factorial(15));
  return 0;
}

Finally, here is a program that calculates the 10th fibonacci number:

use "io.bsk";

int fib(int n) {
  if (n == 0) {
    return 0;
  }
  if (n == 1) {
    return 1;
  }
  return fib(n - 1) + fib(n - 2);
}

int main() {
  put_int(fib(10));
  return 0;
}

The compiler

The compiler is written in C++ and uses the LLVM library to generate the IR code. The compiler can generate the AST, the IR code, or compile and link to an executable.

The compiler can be run using the baskc binary. This is the help message:

Usage: bask [options] [file]
Options:
  -o <file>  Output file
  -l <path>  Library path
  -O <level> Optimization level
  -c         Compile
  -r         Run
  -i         Generate IR
  -a         Generate AST
  -h         Display this help message

Building

This project depends on llvm-14.0.0. You can install it using your package manager. For example, on Ubuntu, you can run:

sudo apt-get install llvm-14

Then, you can build the project using CMake:

mkdir build
cd build
cmake ..
make

You must also build the standard library:

cd lib
make

You should put a simlink to the standard library in the /usr/local/lib directory so it can be found by the compiler:

sudo ln -s lib/build /usr/local/lib/bask

Or you can specify the path to the standard library in the cli using the -l flag.

Running the tests

The unit tests are written using gtest. You can run them by executing the baskctest binary in the build directory.

The other tests can be run by running the "all.sh" script in the tests directory, or a specific suite (labled TESTSUITE_*.sh). The testsuites will run the compiler on the test files in the corresponding directory and compare the output to the expected output.