mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-26 16:54:01 +00:00
70 lines
1.9 KiB
Rust
70 lines
1.9 KiB
Rust
#![feature(trait_upcasting)]
|
|
// known-bug: #120222
|
|
// check-pass
|
|
//! This will segfault at runtime.
|
|
|
|
pub trait SupSupA {
|
|
fn method(&self) {}
|
|
}
|
|
pub trait SupSupB {}
|
|
impl<T> SupSupA for T {}
|
|
impl<T> SupSupB for T {}
|
|
|
|
pub trait Super<T>: SupSupA + SupSupB {}
|
|
|
|
pub trait Unimplemented {}
|
|
|
|
pub trait Trait<T1, T2>: Super<T1> + Super<T2> {
|
|
fn missing_method(&self)
|
|
where
|
|
T1: Unimplemented,
|
|
{
|
|
}
|
|
}
|
|
|
|
impl<S, T> Super<T> for S {}
|
|
|
|
impl<S, T1, T2> Trait<T1, T2> for S {}
|
|
|
|
#[inline(never)]
|
|
pub fn user1() -> &'static dyn Trait<u8, u8> {
|
|
&()
|
|
/* VTABLE:
|
|
.L__unnamed_2:
|
|
.quad core::ptr::drop_in_place<()>
|
|
.asciz "\000\000\000\000\000\000\000\000\001\000\000\000\000\000\000"
|
|
.quad example::SupSupA::method
|
|
.quad .L__unnamed_4 // SupSupB vtable (pointer)
|
|
.zero 8 // null pointer for missing_method
|
|
*/
|
|
}
|
|
|
|
#[inline(never)]
|
|
pub fn user2() -> &'static dyn Trait<u8, u16> {
|
|
&()
|
|
/* VTABLE:
|
|
.L__unnamed_3:
|
|
.quad core::ptr::drop_in_place<()>
|
|
.asciz "\000\000\000\000\000\000\000\000\001\000\000\000\000\000\000"
|
|
.quad example::SupSupA::method
|
|
.quad .L__unnamed_4 // SupSupB vtable (pointer)
|
|
.quad .L__unnamed_5 // Super<u16> vtable (pointer)
|
|
.zero 8 // null pointer for missing_method
|
|
*/
|
|
}
|
|
|
|
fn main() {
|
|
let p: *const dyn Trait<u8, u8> = &();
|
|
let p = p as *const dyn Trait<u8, u16>; // <- this is bad!
|
|
let p = p as *const dyn Super<u16>; // <- this upcast accesses improper vtable entry
|
|
// accessing from L__unnamed_2 the position for the 'Super<u16> vtable (pointer)',
|
|
// thus reading 'null pointer for missing_method'
|
|
|
|
let p = p as *const dyn SupSupB; // <- this upcast dereferences (null) pointer from that entry
|
|
// to read the SupSupB vtable (pointer)
|
|
|
|
// SEGFAULT
|
|
|
|
println!("{:?}", p);
|
|
}
|