A badly named, in-progress programming language just to learn how these things work. Wait, doesn't everyone write a compiler when they're bored?

Currently, the language is comparable to C, with some syntax changes inspired by Rust (that also make it a little easier to parse). The compiler outputs assembly code in yasm format, so you will need yasm and a linker of your choice to compile it. The included Makefile and scripts use ld. (Alternatively, you can use nasm, but you will have to change the command being run in compiler/main.cup and meta/bootstrap.sh)

Only linux and macOS (only on x86_64) are supported.

For now, there's no support for looking at the PATH, so it's a bin wonky. Make sure that you have the following tools (with the executables avialable in the correct places, or you might need to modify the paths manually in main/compiler.cup):

• yasm: The assembler we are using.
  • On linux, the code expects to find this at /usr/bin/yasm.
  • On macOS, the code expects to find this at /usr/local/bin/yasm.
• ld: The linker we are using.
  • On both linux and macOS, the code expects to find this at /usr/bin/ld.

The reference implementation of the compiler is written in CUP, so you'll need to use the pre-compiled YASM files to get the initial executable. You should be able to run the command below to create the ./build/cupcc compiler:

$ ./meta/bootstrap.sh

Compile a program (and optionally run it) using:

$ ./build/cupcc /path/to/program.cup -o prog
$ ./prog 1 2 3 4
# OR
$ ./build/cupcc /path/to/program.cup -o prog -r 1 2 3 4

import "std/common.cup";

fn main(arc: int, argv: char**): int {
    putsln("Hello, world!");
    return 0;
}

fn main() {
    let x: int = 5;  // Explicity define the type
    let y = 6;       // Infer the type
    let z = x + y;   // Add them, and infer the type
}

fn main() {
    let x: int[10];  // An array of 10 ints (initializers not supported)
    let y: int* = x; // Automatically decays to a pointer when passed or assigned
    let z = y;       // type(z) == int* also works
    
    let a = x[0];    // Access the first element (`a` is an int)
    let b = *(x+1);  // Access the second element (can use pointer arithmetic)
}

// For now, enums just generate constant values with sequential numbers.
// They aren't a "type" on their own.
enum Type {
    TypeInt,
    TypeFloat,
    TypeChar,
}

struct Variable {
    typ: int;        // Can't use `Type` here, because it's not a type
    value: union {   // Anonymous nested structures are allowed.
        as_int: int;
        as_char: char;
        as_ptr: Variable*;  // Can recursively define types.
    };
};

fn main() {
    let x: Variable; // No struct initializers yet
    x.typ = TypeInt;
    x.value.as_int = 5;
}

struct Value {
    x: int;
};

method Value::inc(amount: int) {
    // self (pointer) is implicitly passed in
    self.x = self.x + amount;
}

method Value::print() {
    print(self.x);
}

fn main() {
    let v: Value;
    let v_ptr = &v;

    v.x = 0;
    // Call methods using `::`
    v::inc(10);
    v_ptr::print(); // Also works for pointers
}

import "std/file.cup";

fn main(argc: int, argv: char**) {
    for (let i = 1; i < argc; ++i) {
        let file = fopen(argv[i], 'r');
        defer file::close();    // Close the file at the end of the block (in each iteration)

        let buf: char[1024];
        let n = file::read(buf, 1024); // use file-specific functions
        while (n > 0) {
            write(0, buf, n); // Use raw system calls
            n = file::read(buf, 1024);
        }
        // file closed here because of defer
    }
}