From 4db812d34dfdf7896d8630307b4608f10f652614 Mon Sep 17 00:00:00 2001
From: Paul Sajna <paulsajna@gmail.com>
Date: Tue, 20 Mar 2018 19:31:58 -0700
Subject: [PATCH] implement rand and srand
---
src/stdlib/Cargo.toml | 1 +
src/stdlib/src/lib.rs | 27 +++++++++++++++++++++------
2 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/src/stdlib/Cargo.toml b/src/stdlib/Cargo.toml
index 97f5d441..cc96a5dc 100644
--- a/src/stdlib/Cargo.toml
+++ b/src/stdlib/Cargo.toml
@@ -12,3 +12,4 @@ platform = { path = "../platform" }
ralloc = { path = "../../ralloc", default-features = false }
ctype = { path = "../ctype" }
errno = { path = "../errno" }
+rand = { git = "https://github.com/rust-lang-nursery/rand/", default-features = false }
diff --git a/src/stdlib/src/lib.rs b/src/stdlib/src/lib.rs
index 575f759a..8a5535f7 100644
--- a/src/stdlib/src/lib.rs
+++ b/src/stdlib/src/lib.rs
@@ -1,15 +1,18 @@
-//! stdlib implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/stdlib.h.html
-
#![no_std]
#![feature(core_intrinsics)]
#![feature(global_allocator)]
+
+///! stdlib implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/stdlib.h.html
+
extern crate ctype;
extern crate errno;
extern crate platform;
extern crate ralloc;
+extern crate rand;
use core::{ptr, str};
+use rand::{Rng, XorShiftRng, SeedableRng};
use errno::*;
use platform::types::*;
@@ -19,8 +22,10 @@ static ALLOCATOR: ralloc::Allocator = ralloc::Allocator;
pub const EXIT_FAILURE: c_int = 1;
pub const EXIT_SUCCESS: c_int = 0;
+pub const RAND_MAX: c_int = 2147483647;
static mut ATEXIT_FUNCS: [Option<extern "C" fn()>; 32] = [None; 32];
+static mut RNG: Option<XorShiftRng> = None;
#[no_mangle]
pub unsafe extern "C" fn a64l(s: *const c_char) -> c_long {
@@ -375,8 +380,18 @@ pub extern "C" fn qsort(
}
#[no_mangle]
-pub extern "C" fn rand() -> c_int {
- unimplemented!();
+pub unsafe extern "C" fn rand() -> c_int {
+ match RNG {
+ Some(ref mut rng) => {
+ rng.gen_range::<c_int>(0, RAND_MAX)
+ },
+ None => {
+ let mut rng = XorShiftRng::from_seed([1; 16]);
+ let ret = rng.gen_range::<c_int>(0, RAND_MAX);
+ RNG = Some(rng);
+ ret
+ },
+ }
}
#[no_mangle]
@@ -425,8 +440,8 @@ pub extern "C" fn setstate(state: *const c_char) -> *mut c_char {
}
#[no_mangle]
-pub extern "C" fn srand(seed: c_uint) {
- unimplemented!();
+pub unsafe extern "C" fn srand(seed: c_uint) {
+ RNG = Some(XorShiftRng::from_seed([seed as u8; 16]));
}
#[no_mangle]
--
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