mirror of
https://github.com/rust-lang/rust.git
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416 lines
11 KiB
Rust
416 lines
11 KiB
Rust
use core::cell::RefCell;
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use core::ptr::*;
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#[test]
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fn test_const_from_raw_parts() {
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const SLICE: &[u8] = &[1, 2, 3, 4];
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const FROM_RAW: &[u8] = unsafe { &*slice_from_raw_parts(SLICE.as_ptr(), SLICE.len()) };
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assert_eq!(SLICE, FROM_RAW);
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let slice = &[1, 2, 3, 4, 5];
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let from_raw = unsafe { &*slice_from_raw_parts(slice.as_ptr(), 2) };
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assert_eq!(&slice[..2], from_raw);
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}
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#[test]
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fn test() {
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unsafe {
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struct Pair {
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fst: isize,
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snd: isize,
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}
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let mut p = Pair { fst: 10, snd: 20 };
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let pptr: *mut Pair = &mut p;
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let iptr: *mut isize = pptr as *mut isize;
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assert_eq!(*iptr, 10);
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*iptr = 30;
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assert_eq!(*iptr, 30);
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assert_eq!(p.fst, 30);
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*pptr = Pair { fst: 50, snd: 60 };
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assert_eq!(*iptr, 50);
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assert_eq!(p.fst, 50);
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assert_eq!(p.snd, 60);
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let v0 = vec![32000u16, 32001u16, 32002u16];
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let mut v1 = vec![0u16, 0u16, 0u16];
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copy(v0.as_ptr().offset(1), v1.as_mut_ptr().offset(1), 1);
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assert!((v1[0] == 0u16 && v1[1] == 32001u16 && v1[2] == 0u16));
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copy(v0.as_ptr().offset(2), v1.as_mut_ptr(), 1);
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assert!((v1[0] == 32002u16 && v1[1] == 32001u16 && v1[2] == 0u16));
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copy(v0.as_ptr(), v1.as_mut_ptr().offset(2), 1);
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assert!((v1[0] == 32002u16 && v1[1] == 32001u16 && v1[2] == 32000u16));
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}
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}
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#[test]
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fn test_is_null() {
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let p: *const isize = null();
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assert!(p.is_null());
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let q = p.wrapping_offset(1);
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assert!(!q.is_null());
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let mp: *mut isize = null_mut();
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assert!(mp.is_null());
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let mq = mp.wrapping_offset(1);
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assert!(!mq.is_null());
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// Pointers to unsized types -- slices
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let s: &mut [u8] = &mut [1, 2, 3];
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let cs: *const [u8] = s;
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assert!(!cs.is_null());
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let ms: *mut [u8] = s;
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assert!(!ms.is_null());
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let cz: *const [u8] = &[];
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assert!(!cz.is_null());
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let mz: *mut [u8] = &mut [];
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assert!(!mz.is_null());
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let ncs: *const [u8] = null::<[u8; 3]>();
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assert!(ncs.is_null());
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let nms: *mut [u8] = null_mut::<[u8; 3]>();
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assert!(nms.is_null());
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// Pointers to unsized types -- trait objects
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let ci: *const dyn ToString = &3;
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assert!(!ci.is_null());
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let mi: *mut dyn ToString = &mut 3;
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assert!(!mi.is_null());
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let nci: *const dyn ToString = null::<isize>();
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assert!(nci.is_null());
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let nmi: *mut dyn ToString = null_mut::<isize>();
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assert!(nmi.is_null());
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}
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#[test]
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fn test_as_ref() {
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unsafe {
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let p: *const isize = null();
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assert_eq!(p.as_ref(), None);
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let q: *const isize = &2;
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assert_eq!(q.as_ref().unwrap(), &2);
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let p: *mut isize = null_mut();
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assert_eq!(p.as_ref(), None);
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let q: *mut isize = &mut 2;
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assert_eq!(q.as_ref().unwrap(), &2);
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// Lifetime inference
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let u = 2isize;
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{
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let p = &u as *const isize;
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assert_eq!(p.as_ref().unwrap(), &2);
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}
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// Pointers to unsized types -- slices
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let s: &mut [u8] = &mut [1, 2, 3];
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let cs: *const [u8] = s;
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assert_eq!(cs.as_ref(), Some(&*s));
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let ms: *mut [u8] = s;
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assert_eq!(ms.as_ref(), Some(&*s));
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let cz: *const [u8] = &[];
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assert_eq!(cz.as_ref(), Some(&[][..]));
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let mz: *mut [u8] = &mut [];
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assert_eq!(mz.as_ref(), Some(&[][..]));
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let ncs: *const [u8] = null::<[u8; 3]>();
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assert_eq!(ncs.as_ref(), None);
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let nms: *mut [u8] = null_mut::<[u8; 3]>();
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assert_eq!(nms.as_ref(), None);
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// Pointers to unsized types -- trait objects
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let ci: *const dyn ToString = &3;
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assert!(ci.as_ref().is_some());
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let mi: *mut dyn ToString = &mut 3;
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assert!(mi.as_ref().is_some());
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let nci: *const dyn ToString = null::<isize>();
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assert!(nci.as_ref().is_none());
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let nmi: *mut dyn ToString = null_mut::<isize>();
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assert!(nmi.as_ref().is_none());
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}
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}
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#[test]
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fn test_as_mut() {
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unsafe {
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let p: *mut isize = null_mut();
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assert!(p.as_mut() == None);
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let q: *mut isize = &mut 2;
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assert!(q.as_mut().unwrap() == &mut 2);
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// Lifetime inference
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let mut u = 2isize;
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{
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let p = &mut u as *mut isize;
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assert!(p.as_mut().unwrap() == &mut 2);
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}
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// Pointers to unsized types -- slices
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let s: &mut [u8] = &mut [1, 2, 3];
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let ms: *mut [u8] = s;
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assert_eq!(ms.as_mut(), Some(&mut [1, 2, 3][..]));
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let mz: *mut [u8] = &mut [];
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assert_eq!(mz.as_mut(), Some(&mut [][..]));
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let nms: *mut [u8] = null_mut::<[u8; 3]>();
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assert_eq!(nms.as_mut(), None);
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// Pointers to unsized types -- trait objects
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let mi: *mut dyn ToString = &mut 3;
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assert!(mi.as_mut().is_some());
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let nmi: *mut dyn ToString = null_mut::<isize>();
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assert!(nmi.as_mut().is_none());
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}
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}
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#[test]
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fn test_ptr_addition() {
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unsafe {
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let xs = vec![5; 16];
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let mut ptr = xs.as_ptr();
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let end = ptr.offset(16);
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while ptr < end {
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assert_eq!(*ptr, 5);
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ptr = ptr.offset(1);
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}
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let mut xs_mut = xs;
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let mut m_ptr = xs_mut.as_mut_ptr();
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let m_end = m_ptr.offset(16);
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while m_ptr < m_end {
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*m_ptr += 5;
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m_ptr = m_ptr.offset(1);
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}
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assert!(xs_mut == vec![10; 16]);
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}
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}
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#[test]
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fn test_ptr_subtraction() {
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unsafe {
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let xs = vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
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let mut idx = 9;
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let ptr = xs.as_ptr();
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while idx >= 0 {
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assert_eq!(*(ptr.offset(idx as isize)), idx as isize);
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idx = idx - 1;
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}
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let mut xs_mut = xs;
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let m_start = xs_mut.as_mut_ptr();
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let mut m_ptr = m_start.offset(9);
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loop {
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*m_ptr += *m_ptr;
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if m_ptr == m_start {
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break;
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}
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m_ptr = m_ptr.offset(-1);
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}
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assert_eq!(xs_mut, [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]);
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}
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}
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#[test]
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fn test_set_memory() {
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let mut xs = [0u8; 20];
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let ptr = xs.as_mut_ptr();
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unsafe {
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write_bytes(ptr, 5u8, xs.len());
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}
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assert!(xs == [5u8; 20]);
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}
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#[test]
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fn test_unsized_nonnull() {
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let xs: &[i32] = &[1, 2, 3];
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let ptr = unsafe { NonNull::new_unchecked(xs as *const [i32] as *mut [i32]) };
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let ys = unsafe { ptr.as_ref() };
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let zs: &[i32] = &[1, 2, 3];
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assert!(ys == zs);
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}
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#[test]
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#[allow(warnings)]
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// Have a symbol for the test below. It doesn’t need to be an actual variadic function, match the
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// ABI, or even point to an actual executable code, because the function itself is never invoked.
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#[no_mangle]
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pub fn test_variadic_fnptr() {
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use core::hash::{Hash, SipHasher};
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extern "C" {
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fn test_variadic_fnptr(_: u64, ...) -> f64;
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}
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let p: unsafe extern "C" fn(u64, ...) -> f64 = test_variadic_fnptr;
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let q = p.clone();
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assert_eq!(p, q);
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assert!(!(p < q));
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let mut s = SipHasher::new();
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assert_eq!(p.hash(&mut s), q.hash(&mut s));
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}
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#[test]
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fn write_unaligned_drop() {
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thread_local! {
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static DROPS: RefCell<Vec<u32>> = RefCell::new(Vec::new());
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}
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struct Dropper(u32);
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impl Drop for Dropper {
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fn drop(&mut self) {
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DROPS.with(|d| d.borrow_mut().push(self.0));
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}
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}
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{
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let c = Dropper(0);
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let mut t = Dropper(1);
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unsafe {
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write_unaligned(&mut t, c);
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}
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}
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DROPS.with(|d| assert_eq!(*d.borrow(), [0]));
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}
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#[test]
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fn align_offset_zst() {
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// For pointers of stride = 0, the pointer is already aligned or it cannot be aligned at
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// all, because no amount of elements will align the pointer.
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let mut p = 1;
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while p < 1024 {
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assert_eq!((p as *const ()).align_offset(p), 0);
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if p != 1 {
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assert_eq!(((p + 1) as *const ()).align_offset(p), !0);
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}
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p = (p + 1).next_power_of_two();
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}
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}
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#[test]
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fn align_offset_stride1() {
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// For pointers of stride = 1, the pointer can always be aligned. The offset is equal to
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// number of bytes.
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let mut align = 1;
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while align < 1024 {
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for ptr in 1..2 * align {
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let expected = ptr % align;
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let offset = if expected == 0 { 0 } else { align - expected };
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assert_eq!(
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(ptr as *const u8).align_offset(align),
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offset,
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"ptr = {}, align = {}, size = 1",
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ptr,
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align
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);
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}
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align = (align + 1).next_power_of_two();
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}
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}
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#[test]
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fn align_offset_weird_strides() {
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#[repr(packed)]
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struct A3(u16, u8);
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struct A4(u32);
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#[repr(packed)]
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struct A5(u32, u8);
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#[repr(packed)]
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struct A6(u32, u16);
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#[repr(packed)]
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struct A7(u32, u16, u8);
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#[repr(packed)]
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struct A8(u32, u32);
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#[repr(packed)]
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struct A9(u32, u32, u8);
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#[repr(packed)]
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struct A10(u32, u32, u16);
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unsafe fn test_weird_stride<T>(ptr: *const T, align: usize) -> bool {
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let numptr = ptr as usize;
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let mut expected = usize::MAX;
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// Naive but definitely correct way to find the *first* aligned element of stride::<T>.
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for el in 0..align {
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if (numptr + el * ::std::mem::size_of::<T>()) % align == 0 {
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expected = el;
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break;
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}
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}
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let got = ptr.align_offset(align);
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if got != expected {
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eprintln!(
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"aligning {:p} (with stride of {}) to {}, expected {}, got {}",
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ptr,
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::std::mem::size_of::<T>(),
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align,
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expected,
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got
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);
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return true;
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}
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return false;
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}
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// For pointers of stride != 1, we verify the algorithm against the naivest possible
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// implementation
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let mut align = 1;
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let mut x = false;
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// Miri is too slow
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let limit = if cfg!(miri) { 32 } else { 1024 };
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while align < limit {
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for ptr in 1usize..4 * align {
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unsafe {
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x |= test_weird_stride::<A3>(ptr as *const A3, align);
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x |= test_weird_stride::<A4>(ptr as *const A4, align);
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x |= test_weird_stride::<A5>(ptr as *const A5, align);
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x |= test_weird_stride::<A6>(ptr as *const A6, align);
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x |= test_weird_stride::<A7>(ptr as *const A7, align);
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x |= test_weird_stride::<A8>(ptr as *const A8, align);
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x |= test_weird_stride::<A9>(ptr as *const A9, align);
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x |= test_weird_stride::<A10>(ptr as *const A10, align);
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}
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}
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align = (align + 1).next_power_of_two();
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}
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assert!(!x);
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}
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#[test]
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fn offset_from() {
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let mut a = [0; 5];
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let ptr1: *mut i32 = &mut a[1];
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let ptr2: *mut i32 = &mut a[3];
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unsafe {
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assert_eq!(ptr2.offset_from(ptr1), 2);
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assert_eq!(ptr1.offset_from(ptr2), -2);
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assert_eq!(ptr1.offset(2), ptr2);
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assert_eq!(ptr2.offset(-2), ptr1);
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}
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}
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