src/libcoretest/ptr.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use core::ptr::*;
  12
  13 #[test]
  14 fn test() {
  15     unsafe {
  16         struct Pair {
  17             fst: isize,
  18             snd: isize
  19         };
  20         let mut p = Pair {fst: 10, snd: 20};
  21         let pptr: *mut Pair = &mut p;
  22         let iptr: *mut isize = pptr as *mut isize;
  23         assert_eq!(*iptr, 10);
  24         *iptr = 30;
  25         assert_eq!(*iptr, 30);
  26         assert_eq!(p.fst, 30);
  27
  28         *pptr = Pair {fst: 50, snd: 60};
  29         assert_eq!(*iptr, 50);
  30         assert_eq!(p.fst, 50);
  31         assert_eq!(p.snd, 60);
  32
  33         let v0 = vec![32000u16, 32001u16, 32002u16];
  34         let mut v1 = vec![0u16, 0u16, 0u16];
  35
  36         copy(v0.as_ptr().offset(1), v1.as_mut_ptr().offset(1), 1);
  37         assert!((v1[0] == 0u16 &&
  38                  v1[1] == 32001u16 &&
  39                  v1[2] == 0u16));
  40         copy(v0.as_ptr().offset(2), v1.as_mut_ptr(), 1);
  41         assert!((v1[0] == 32002u16 &&
  42                  v1[1] == 32001u16 &&
  43                  v1[2] == 0u16));
  44         copy(v0.as_ptr(), v1.as_mut_ptr().offset(2), 1);
  45         assert!((v1[0] == 32002u16 &&
  46                  v1[1] == 32001u16 &&
  47                  v1[2] == 32000u16));
  48     }
  49 }
  50
  51 #[test]
  52 fn test_is_null() {
  53     let p: *const isize = null();
  54     assert!(p.is_null());
  55
  56     let q = unsafe { p.offset(1) };
  57     assert!(!q.is_null());
  58
  59     let mp: *mut isize = null_mut();
  60     assert!(mp.is_null());
  61
  62     let mq = unsafe { mp.offset(1) };
  63     assert!(!mq.is_null());
  64 }
  65
  66 #[test]
  67 fn test_as_ref() {
  68     unsafe {
  69         let p: *const isize = null();
  70         assert_eq!(p.as_ref(), None);
  71
  72         let q: *const isize = &2;
  73         assert_eq!(q.as_ref().unwrap(), &2);
  74
  75         let p: *mut isize = null_mut();
  76         assert_eq!(p.as_ref(), None);
  77
  78         let q: *mut isize = &mut 2;
  79         assert_eq!(q.as_ref().unwrap(), &2);
  80
  81         // Lifetime inference
  82         let u = 2isize;
  83         {
  84             let p = &u as *const isize;
  85             assert_eq!(p.as_ref().unwrap(), &2);
  86         }
  87     }
  88 }
  89
  90 #[test]
  91 fn test_as_mut() {
  92     unsafe {
  93         let p: *mut isize = null_mut();
  94         assert!(p.as_mut() == None);
  95
  96         let q: *mut isize = &mut 2;
  97         assert!(q.as_mut().unwrap() == &mut 2);
  98
  99         // Lifetime inference
 100         let mut u = 2isize;
 101         {
 102             let p = &mut u as *mut isize;
 103             assert!(p.as_mut().unwrap() == &mut 2);
 104         }
 105     }
 106 }
 107
 108 #[test]
 109 fn test_ptr_addition() {
 110     unsafe {
 111         let xs = vec![5; 16];
 112         let mut ptr = xs.as_ptr();
 113         let end = ptr.offset(16);
 114
 115         while ptr < end {
 116             assert_eq!(*ptr, 5);
 117             ptr = ptr.offset(1);
 118         }
 119
 120         let mut xs_mut = xs;
 121         let mut m_ptr = xs_mut.as_mut_ptr();
 122         let m_end = m_ptr.offset(16);
 123
 124         while m_ptr < m_end {
 125             *m_ptr += 5;
 126             m_ptr = m_ptr.offset(1);
 127         }
 128
 129         assert!(xs_mut == vec![10; 16]);
 130     }
 131 }
 132
 133 #[test]
 134 fn test_ptr_subtraction() {
 135     unsafe {
 136         let xs = vec![0,1,2,3,4,5,6,7,8,9];
 137         let mut idx = 9;
 138         let ptr = xs.as_ptr();
 139
 140         while idx >= 0 {
 141             assert_eq!(*(ptr.offset(idx as isize)), idx as isize);
 142             idx = idx - 1;
 143         }
 144
 145         let mut xs_mut = xs;
 146         let m_start = xs_mut.as_mut_ptr();
 147         let mut m_ptr = m_start.offset(9);
 148
 149         while m_ptr >= m_start {
 150             *m_ptr += *m_ptr;
 151             m_ptr = m_ptr.offset(-1);
 152         }
 153
 154         assert_eq!(xs_mut, [0,2,4,6,8,10,12,14,16,18]);
 155     }
 156 }
 157
 158 #[test]
 159 fn test_set_memory() {
 160     let mut xs = [0u8; 20];
 161     let ptr = xs.as_mut_ptr();
 162     unsafe { write_bytes(ptr, 5u8, xs.len()); }
 163     assert!(xs == [5u8; 20]);
 164 }
 165
 166 #[test]
 167 fn test_unsized_unique() {
 168     let xs: &mut [i32] = &mut [1, 2, 3];
 169     let ptr = unsafe { Unique::new(xs as *mut [i32]) };
 170     let ys = unsafe { &mut **ptr };
 171     let zs: &mut [i32] = &mut [1, 2, 3];
 172     assert!(ys == zs);
 173 }