Files
zig/std/std.zig
2016-01-02 03:38:45 -07:00

96 lines
2.4 KiB
Zig

const SYS_write : isize = 1;
const SYS_exit : isize = 60;
const SYS_getrandom : isize = 278;
const stdout_fileno : isize = 1;
const stderr_fileno : isize = 2;
fn syscall1(number: isize, arg1: isize) -> isize {
asm volatile ("syscall"
: [ret] "={rax}" (-> isize)
: [number] "{rax}" (number), [arg1] "{rdi}" (arg1)
: "rcx", "r11")
}
fn syscall3(number: isize, arg1: isize, arg2: isize, arg3: isize) -> isize {
asm volatile ("syscall"
: [ret] "={rax}" (-> isize)
: [number] "{rax}" (number), [arg1] "{rdi}" (arg1), [arg2] "{rsi}" (arg2), [arg3] "{rdx}" (arg3)
: "rcx", "r11")
}
/*
pub fn getrandom(buf: &u8, count: usize, flags: u32) -> isize {
return syscall3(SYS_getrandom, buf as isize, count as isize, flags as isize);
}
*/
pub fn write(fd: isize, buf: &const u8, count: usize) -> isize {
return syscall3(SYS_write, fd, buf as isize, count as isize);
}
pub fn exit(status: i32) -> unreachable {
syscall1(SYS_exit, status as isize);
unreachable;
}
/*
fn digit_to_char(digit: u64) -> u8 { '0' + (digit as u8) }
const max_u64_base10_digits: usize = 20;
fn buf_print_u64(out_buf: &u8, x: u64) -> usize {
// TODO use max_u64_base10_digits instead of hardcoding 20
var buf: [u8; 20];
var a = x;
var index = max_u64_base10_digits;
while (true) {
const digit = a % 10;
index -= 1;
buf[index] = digit_to_char(digit);
a /= 10;
if (a == 0)
break;
}
const len = max_u64_base10_digits - index;
// TODO memcpy intrinsic
var i: usize = 0;
while (i < len) {
out_buf[i] = buf[index + i];
i += 1;
}
return len;
}
// TODO handle buffering and flushing (mutex protected)
// TODO error handling
pub fn print_u64(x: u64) -> isize {
// TODO use max_u64_base10_digits instead of hardcoding 20
var buf: [u8; 20];
const len = buf_print_u64(buf.ptr, x);
return write(stdout_fileno, buf.ptr, len);
}
*/
// TODO error handling
// TODO handle buffering and flushing (mutex protected)
pub fn print_str(str: string) -> isize { fprint_str(stdout_fileno, str) }
// TODO error handling
// TODO handle buffering and flushing (mutex protected)
pub fn fprint_str(fd: isize, str: string) -> isize {
return write(fd, str.ptr, str.len);
}
/*
// TODO error handling
pub fn os_get_random_bytes(buf: &u8, count: usize) -> isize {
return getrandom(buf, count, 0);
}
*/