src/test/ui/borrowck/slice-index-bounds-check-invalidation.rs

   1 // Test that we error if a slice is modified after it has been bounds checked
   2 // and before we actually index it.
   3
   4 fn modify_before_assert_slice_slice(x: &[&[i32]]) -> i32 {
   5     let mut x = x;
   6     let z: &[i32] = &[1, 2, 3];
   7     let y: &[&[i32]] = &[z];
   8     x[{ x = y; 0 }][2]              // OK we haven't checked any bounds before we index `x`.
   9 }
  10
  11 fn modify_before_assert_array_slice(x: &[&[i32]; 3]) -> i32 {
  12     let mut x = x;
  13     let z: &[i32] = &[1, 2, 3];
  14     let y: &[&[i32]; 3] = &[z, z, z];
  15     x[{ x = y; 0 }][2]              // OK we haven't checked any bounds before we index `x`.
  16 }
  17
  18 fn modify_before_assert_slice_array(x: &[&[i32; 3]]) -> i32 {
  19     let mut x = x;
  20     let z: &[i32; 3] = &[1, 2, 3];
  21     let y: &[&[i32; 3]] = &[z];
  22     x[{ x = y; 0 }][2]              // OK we haven't checked any bounds before we index `x`.
  23 }
  24
  25 fn modify_before_assert_array_array(x: &[&[i32; 3]; 3]) -> i32 {
  26     let mut x = x;
  27     let z: &[i32; 3] = &[1, 2, 3];
  28     let y: &[&[i32; 3]; 3] = &[z, z, z];
  29     x[{ x = y; 0 }][2]              // OK we haven't checked any bounds before we index `x`.
  30 }
  31
  32 fn modify_after_assert_slice_slice(x: &[&[i32]]) -> i32 {
  33     let mut x = x;
  34     let z: &[i32] = &[1, 2, 3];
  35     let y: &[&[i32]] = &[&z];
  36     x[1][{ x = y; 2}]               //~ ERROR cannot assign `x` in indexing expression
  37 }
  38
  39 fn modify_after_assert_array_slice(x: &[&[i32]; 1]) -> i32 {
  40     let mut x = x;
  41     let z: &[i32] = &[1, 2, 3];
  42     let y: &[&[i32]; 1] = &[&z];
  43     x[0][{ x = y; 2}]               // OK cannot invalidate a fixed-size array bounds check
  44 }
  45
  46 fn modify_after_assert_slice_array(x: &[&[i32; 3]]) -> i32 {
  47     let mut x = x;
  48     let z: &[i32; 3] = &[1, 2, 3];
  49     let y: &[&[i32; 3]] = &[&z];
  50     x[1][{ x = y; 2}]               //~ ERROR cannot assign `x` in indexing expression
  51 }
  52
  53 fn modify_after_assert_array_array(x: &[&[i32; 3]; 1]) -> i32 {
  54     let mut x = x;
  55     let z: &[i32; 3] = &[1, 2, 3];
  56     let y: &[&[i32; 3]; 1] = &[&z];
  57     x[0][{ x = y; 2}]               // OK cannot invalidate a fixed-size array bounds check
  58 }
  59
  60 fn modify_after_assert_slice_slice_array(x: &[&[[i32; 1]]]) -> i32 {
  61     let mut x = x;
  62     let z: &[[i32; 1]] = &[[1], [2], [3]];
  63     let y: &[&[[i32; 1]]] = &[&z];
  64     x[1][{ x = y; 2}][0]            //~ ERROR cannot assign `x` in indexing expression
  65 }
  66
  67 fn modify_after_assert_slice_slice_slice(x: &[&[&[i32]]]) -> i32 {
  68     let mut x = x;
  69     let z: &[&[i32]] = &[&[1], &[2], &[3]];
  70     let y: &[&[&[i32]]] = &[z];
  71     x[1][{ x = y; 2}][0]            //~ ERROR cannot assign `x` in indexing expression
  72 }
  73
  74
  75 fn main() {
  76     println!("{}", modify_after_assert_slice_array(&[&[4, 5, 6], &[9, 10, 11]]));
  77     println!("{}", modify_after_assert_slice_slice(&[&[4, 5, 6], &[9, 10, 11]]));
  78     println!("{}", modify_after_assert_slice_slice_array(&[&[[4], [5], [6]], &[[9], [10], [11]]]));
  79     println!("{}", modify_after_assert_slice_slice_slice(
  80         &[&[&[4], &[5], &[6]], &[&[9], &[10], &[11]]]),
  81     );
  82 }