103 lines
2.7 KiB
Rust
103 lines
2.7 KiB
Rust
// This returns a miri pointer at type usize, if the argument is a proper pointer
|
|
fn transmute_ptr_to_int<T>(x: *const T) -> usize {
|
|
unsafe { std::mem::transmute(x) }
|
|
}
|
|
|
|
fn cast() {
|
|
// Some casting-to-int with arithmetic.
|
|
let x = &42 as *const i32 as usize;
|
|
let y = x * 2;
|
|
assert_eq!(y, x + x);
|
|
let z = y as u8 as usize;
|
|
assert_eq!(z, y % 256);
|
|
}
|
|
|
|
/// Test usize->ptr cast for dangling and OOB address.
|
|
/// That is safe, and thus has to work.
|
|
fn cast_dangling() {
|
|
let b = Box::new(0);
|
|
let x = &*b as *const i32 as usize;
|
|
drop(b);
|
|
let _val = x as *const i32;
|
|
|
|
let b = Box::new(0);
|
|
let mut x = &*b as *const i32 as usize;
|
|
x += 0x100;
|
|
let _val = x as *const i32;
|
|
}
|
|
|
|
fn format() {
|
|
// Pointer string formatting! We can't check the output as it changes when libstd changes,
|
|
// but we can make sure Miri does not error.
|
|
format!("{:?}", &mut 13 as *mut _);
|
|
}
|
|
|
|
fn transmute() {
|
|
// Check that intptrcast is triggered for explicit casts and that it is consistent with
|
|
// transmuting.
|
|
let a: *const i32 = &42;
|
|
let b = transmute_ptr_to_int(a) as u8;
|
|
let c = a as usize as u8;
|
|
assert_eq!(b, c);
|
|
}
|
|
|
|
fn ptr_bitops1() {
|
|
let bytes = [0i8, 1, 2, 3, 4, 5, 6, 7, 8, 9];
|
|
let one = bytes.as_ptr().wrapping_offset(1);
|
|
let three = bytes.as_ptr().wrapping_offset(3);
|
|
let res = (one as usize) | (three as usize);
|
|
format!("{}", res);
|
|
}
|
|
|
|
fn ptr_bitops2() {
|
|
let val = 13usize;
|
|
let addr = &val as *const _ as usize;
|
|
let _val = addr & 13;
|
|
}
|
|
|
|
fn ptr_eq_dangling() {
|
|
let b = Box::new(0);
|
|
let x = &*b as *const i32; // soon-to-be dangling
|
|
drop(b);
|
|
let b = Box::new(0);
|
|
let y = &*b as *const i32; // different allocation
|
|
// They *could* be equal if memory was reused, but probably are not.
|
|
assert!(x != y);
|
|
}
|
|
|
|
fn ptr_eq_out_of_bounds() {
|
|
let b = Box::new(0);
|
|
let x = (&*b as *const i32).wrapping_sub(0x800); // out-of-bounds
|
|
let b = Box::new(0);
|
|
let y = &*b as *const i32; // different allocation
|
|
// They *could* be equal (with the right base addresses), but probably are not.
|
|
assert!(x != y);
|
|
}
|
|
|
|
fn ptr_eq_out_of_bounds_null() {
|
|
let b = Box::new(0);
|
|
let x = (&*b as *const i32).wrapping_sub(0x800); // out-of-bounds
|
|
// This *could* be NULL (with the right base address), but probably is not.
|
|
assert!(x != std::ptr::null());
|
|
}
|
|
|
|
fn ptr_eq_integer() {
|
|
let b = Box::new(0);
|
|
let x = &*b as *const i32;
|
|
// These *could* be equal (with the right base address), but probably are not.
|
|
assert!(x != 64 as *const i32);
|
|
}
|
|
|
|
fn main() {
|
|
cast();
|
|
cast_dangling();
|
|
format();
|
|
transmute();
|
|
ptr_bitops1();
|
|
ptr_bitops2();
|
|
ptr_eq_dangling();
|
|
ptr_eq_out_of_bounds();
|
|
ptr_eq_out_of_bounds_null();
|
|
ptr_eq_integer();
|
|
}
|