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//@ run-crash
//@ check-run-results
//@ exec-env:RUST_BACKTRACE=0
//@ normalize-stderr: "(core/src/panicking\.rs):[0-9]+:[0-9]+" -> "$1:$$LINE:$$COL"
//@ ignore-backends: gcc
#![feature(extern_types)]
extern "C" {
type Opaque;
}
struct Newtype(Opaque);
struct S {
i: i32,
j: i32,
a: Newtype,
}
fn main() {
let buf = [0i32; 4];
let x: &Newtype = unsafe { &*(&buf as *const _ as *const Newtype) };
// Projecting to the newtype works, because it is always at offset 0.
let field = &x.0;
// Avoid being eliminated by DSE.
std::hint::black_box(field);
let x: &S = unsafe { &*(&buf as *const _ as *const S) };
// Accessing sized fields is perfectly fine, even at non-zero offsets.
let field = &x.i;
std::hint::black_box(field);
let field = &x.j;
std::hint::black_box(field);
// This needs to compute the field offset, but we don't know the type's alignment,
// so this panics.
let field = &x.a;
std::hint::black_box(field);
}
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