main.c

#include "y3c.h"

static int align_to(int n, int align) {
    return (n + align - 1) / align * align;
}

int main(int argc, char **argv) {
    if (argc != 2)
        error("%s: invalid number of arguments.", argv[0]);

    // Tokenize and parse.
    Token *tok = tokenize(argv[1]);
    Function *prog = parse(tok);
    // Assign offsets to local variables.
    for (Function *fn = prog; fn; fn = fn->next) {
        int offset = 32; // 32 for callee-saved registers
        for (Var *var = fn->locals; var; var = var->next) {
            offset += var->ty->size;
            var->offset = offset;
        }
        fn->stack_size = align_to(offset, 16);
    }

    // Traverse the AST to emit assembly.
    codegen(prog);

    return 0;
}