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Refactor rand48 functions with less unsafe

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This commit is contained in:
Peter Limkilde Svendsen
2024-07-15 17:44:56 +00:00
committed by Jeremy Soller
parent 3cd21243ec
commit dbcf8049fc
3 changed files with 180 additions and 109 deletions
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src/header/stdlib/mod.rs
+54 -35
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@@ -263,9 +263,11 @@ pub extern "C" fn div(numer: c_int, denom: c_int) -> div_t {
}
#[no_mangle]
pub unsafe extern "C" fn drand48() -> c_double {
let new_xsubi_value = rand48::generator_step(&mut rand48::DEFAULT_XSUBI);
rand48::f64_from_x(new_xsubi_value)
pub extern "C" fn drand48() -> c_double {
let params = rand48::params_lock();
let mut xsubi = rand48::xsubi_lock();
*xsubi = params.step(*xsubi);
xsubi.get_f64()
}
// #[no_mangle]
@@ -280,8 +282,11 @@ pub extern "C" fn ecvt(
#[no_mangle]
pub unsafe extern "C" fn erand48(xsubi: *mut c_ushort) -> c_double {
let new_xsubi_value = rand48::generator_step(&mut *(xsubi as *mut [c_ushort; 3]));
rand48::f64_from_x(new_xsubi_value)
let params = rand48::params_lock();
let xsubi_mut: &mut [c_ushort; 3] = slice::from_raw_parts_mut(xsubi, 3).try_into().unwrap();
let new_xsubi_value = params.step(xsubi_mut.into());
*xsubi_mut = new_xsubi_value.into();
new_xsubi_value.get_f64()
}
#[no_mangle]
@@ -440,8 +445,11 @@ pub unsafe extern "C" fn initstate(seed: c_uint, state: *mut c_char, size: size_
#[no_mangle]
pub unsafe extern "C" fn jrand48(xsubi: *mut c_ushort) -> c_long {
let new_xsubi_value = rand48::generator_step(&mut *(xsubi as *mut [c_ushort; 3]));
rand48::i32_from_x(new_xsubi_value)
let params = rand48::params_lock();
let xsubi_mut: &mut [c_ushort; 3] = slice::from_raw_parts_mut(xsubi, 3).try_into().unwrap();
let new_xsubi_value = params.step(xsubi_mut.into());
*xsubi_mut = new_xsubi_value.into();
new_xsubi_value.get_i32()
}
#[no_mangle]
@@ -490,16 +498,17 @@ pub extern "C" fn labs(i: c_long) -> c_long {
#[no_mangle]
pub unsafe extern "C" fn lcong48(param: *mut c_ushort) {
// Set DEFAULT_XSUBI buffer from elements 0-2
let xsubi_value = rand48::u48_from_ushort_arr3(&*(param as *const [c_ushort; 3]));
rand48::DEFAULT_XSUBI = rand48::ushort_arr3_from_u48(xsubi_value);
let mut xsubi = rand48::xsubi_lock();
let mut params = rand48::params_lock();
// Set multiplier from elements 3-5
rand48::A = rand48::u48_from_ushort_arr3(&*(param.offset(3) as *const [c_ushort; 3]));
let param_slice = slice::from_raw_parts(param, 7);
/* Set addend from element 6. Note that c_ushort may be more than 16
* bits, thus the cast. */
rand48::C = *param.offset(6) as u16;
let xsubi_ref: &[c_ushort; 3] = param_slice[0..3].try_into().unwrap();
let a_ref: &[c_ushort; 3] = param_slice[3..6].try_into().unwrap();
let c = param_slice[6];
*xsubi = xsubi_ref.into();
params.set(a_ref, c);
}
#[repr(C)]
@@ -536,9 +545,11 @@ pub extern "C" fn lldiv(numer: c_longlong, denom: c_longlong) -> lldiv_t {
}
#[no_mangle]
pub unsafe extern "C" fn lrand48() -> c_long {
let new_xsubi_value = rand48::generator_step(&mut rand48::DEFAULT_XSUBI);
rand48::u31_from_x(new_xsubi_value)
pub extern "C" fn lrand48() -> c_long {
let params = rand48::params_lock();
let mut xsubi = rand48::xsubi_lock();
*xsubi = params.step(*xsubi);
xsubi.get_u31()
}
#[no_mangle]
@@ -694,15 +705,20 @@ pub unsafe extern "C" fn mkstemps(name: *mut c_char, suffix_len: c_int) -> c_int
}
#[no_mangle]
pub unsafe extern "C" fn mrand48() -> c_long {
let new_xsubi_value = rand48::generator_step(&mut rand48::DEFAULT_XSUBI);
rand48::i32_from_x(new_xsubi_value)
pub extern "C" fn mrand48() -> c_long {
let params = rand48::params_lock();
let mut xsubi = rand48::xsubi_lock();
*xsubi = params.step(*xsubi);
xsubi.get_i32()
}
#[no_mangle]
pub unsafe extern "C" fn nrand48(xsubi: *mut c_ushort) -> c_long {
let new_xsubi_value = rand48::generator_step(&mut *(xsubi as *mut [c_ushort; 3]));
rand48::u31_from_x(new_xsubi_value)
let params = rand48::params_lock();
let xsubi_mut: &mut [c_ushort; 3] = slice::from_raw_parts_mut(xsubi, 3).try_into().unwrap();
let new_xsubi_value = params.step(xsubi_mut.into());
*xsubi_mut = new_xsubi_value.into();
new_xsubi_value.get_u31()
}
#[no_mangle]
@@ -978,17 +994,17 @@ pub unsafe extern "C" fn realpath(pathname: *const c_char, resolved: *mut c_char
#[no_mangle]
pub unsafe extern "C" fn seed48(seed16v: *mut c_ushort) -> *mut c_ushort {
rand48::reset_a_and_c();
static mut BUFFER: [c_ushort; 3] = [0; 3];
// Stash current DEFAULT_XSUBI value in SEED48_XSUBI
rand48::SEED48_XSUBI = rand48::DEFAULT_XSUBI;
let mut params = rand48::params_lock();
let mut xsubi = rand48::xsubi_lock();
// Set DEFAULT_XSUBI from the argument provided
let xsubi_value = rand48::u48_from_ushort_arr3(&*(seed16v as *const [c_ushort; 3]));
rand48::DEFAULT_XSUBI = rand48::ushort_arr3_from_u48(xsubi_value);
let seed16v_ref: &[c_ushort; 3] = slice::from_raw_parts(seed16v, 3).try_into().unwrap();
// Return the stashed value
rand48::SEED48_XSUBI.as_mut_ptr()
BUFFER = (*xsubi).into();
*xsubi = seed16v_ref.into();
params.reset();
BUFFER.as_mut_ptr()
}
unsafe fn copy_kv(
@@ -1066,14 +1082,17 @@ pub unsafe extern "C" fn srand(seed: c_uint) {
}
#[no_mangle]
pub unsafe extern "C" fn srand48(seedval: c_long) {
rand48::reset_a_and_c();
pub extern "C" fn srand48(seedval: c_long) {
let mut params = rand48::params_lock();
let mut xsubi = rand48::xsubi_lock();
params.reset();
/* Set the high 32 bits of the 48-bit X_i value to the lower 32 bits
* of the input argument, and the lower 16 bits to 0x330e, as
* specified in POSIX. */
let xsubi_value = (u64::from(seedval as u32) << 16) | 0x330e;
rand48::DEFAULT_XSUBI = rand48::ushort_arr3_from_u48(xsubi_value);
*xsubi = ((u64::from(seedval as u32) << 16) | 0x330e)
.try_into()
.unwrap();
}
#[no_mangle]