src/test/ui/consts/offset_ub.rs

   1 use std::ptr;
   2
   3 // normalize-stderr-test "alloc\d+" -> "allocN"
   4 // normalize-stderr-test "0x7f+" -> "0x7f..f"
   5
   6
   7 pub const BEFORE_START: *const u8 = unsafe { (&0u8 as *const u8).offset(-1) }; //~NOTE
   8 pub const AFTER_END: *const u8 = unsafe { (&0u8 as *const u8).offset(2) }; //~NOTE
   9 pub const AFTER_ARRAY: *const u8 = unsafe { [0u8; 100].as_ptr().offset(101) }; //~NOTE
  10
  11 pub const OVERFLOW: *const u16 = unsafe { [0u16; 1].as_ptr().offset(isize::MAX) }; //~NOTE
  12 pub const UNDERFLOW: *const u16 = unsafe { [0u16; 1].as_ptr().offset(isize::MIN) }; //~NOTE
  13 pub const OVERFLOW_ADDRESS_SPACE: *const u8 = unsafe { (usize::MAX as *const u8).offset(2) }; //~NOTE
  14 pub const UNDERFLOW_ADDRESS_SPACE: *const u8 = unsafe { (1 as *const u8).offset(-2) }; //~NOTE
  15 pub const NEGATIVE_OFFSET: *const u8 = unsafe { [0u8; 1].as_ptr().wrapping_offset(-2).offset(-2) }; //~NOTE
  16
  17 pub const ZERO_SIZED_ALLOC: *const u8 = unsafe { [0u8; 0].as_ptr().offset(1) }; //~NOTE
  18 pub const DANGLING: *const u8 = unsafe { ptr::NonNull::<u8>::dangling().as_ptr().offset(4) }; //~NOTE
  19
  20 // Right now, a zero offset from null is UB
  21 pub const NULL_OFFSET_ZERO: *const u8 = unsafe { ptr::null::<u8>().offset(0) }; //~NOTE
  22
  23 // Make sure that we don't panic when computing abs(offset*size_of::<T>())
  24 pub const UNDERFLOW_ABS: *const u8 = unsafe { (usize::MAX as *const u8).offset(isize::MIN) }; //~NOTE
  25
  26 fn main() {}