zig/std/mem.zig

import "syscall.zig";
import "std.zig";
import "errno.zig";

pub fn malloc(bytes: isize) -> ?&u8 {
    if (bytes > 4096) {
        %%stderr.printf("TODO alloc sizes > 4096B\n");
        return null;
    }

    const result = mmap(isize(0), 4096, MMAP_PROT_READ|MMAP_PROT_WRITE, MMAP_MAP_ANON|MMAP_MAP_SHARED, -1, 0);

    const failed: bool = switch (-result) {
        0          => true,
        -1         => true,
        EINVAL     => true,
        EACCES     => true,
        EAGAIN     => true,
        EBADF      => true,
        EMFILE     => true,
        ENODEV     => true,
        ENOMEM     => true,
        EOPNOTSUPP => true,
        ENXIO      => true,
        EOVERFLOW  => true,
        else       => false,
    };

    if (failed) {
        null
    } else {
        (&u8)(result)
    }
}

pub fn free(ptr: &u8) {
    munmap(isize(ptr), 4096);
}