ICE: stack overflow in self-referential struct in clippy_utils::ty::is_normalizable_helper

[matthiaskrgr]

Summary

clippy-driver file.rs is enough.

use std::marker::PhantomData;

struct Node<T: 'static> {
    m: PhantomData<&'static T>,
}

struct Digit<T> {
    elem: T,
}

enum FingerTree<T: 'static> {
    Single(T),

    Deep(Digit<T>, Box<FingerTree<Node<T>>>),
}

fn main() {}

Version

rustc 1.70.0-nightly (171693274 2023-03-14)
binary: rustc
commit-hash: 1716932743a7b3705cbf0c34db0c4e070ed1930d
commit-date: 2023-03-14
host: x86_64-unknown-linux-gnu
release: 1.70.0-nightly
LLVM version: 15.0.7

Error output

Backtrace

0x0000555555c54817 in clippy_utils::ty::is_normalizable_helper ()
(gdb) bt
#0  0x0000555555c54817 in clippy_utils::ty::is_normalizable_helper ()
#1  0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#2  0x0000555555c54c79 in clippy_utils::ty::is_normalizable_helper ()
#3  0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#4  0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#5  0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#6  0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#7  0x0000555555c54c79 in clippy_utils::ty::is_normalizable_helper ()
#8  0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#9  0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#10 0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#11 0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#12 0x0000555555c54c79 in clippy_utils::ty::is_normalizable_helper ()
#13 0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#14 0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#15 0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#16 0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()
#17 0x0000555555c54c79 in clippy_utils::ty::is_normalizable_helper ()
#18 0x0000555555c54b29 in clippy_utils::ty::is_normalizable_helper ()

[Jarcho]

Was this used in real code? FingerTree can't be instantiated as written.

[matthiaskrgr]

No this was fuzzed

[matthiaskrgr]

another variant

use std::marker::PhantomData;

struct Digit<T> {
    elem: T
}

struct Node<T:'static> { m: PhantomData<&'static T> }

enum FingerTree<T:'static> {
    Single(T),
    
    Deep(
        Digit<T>,
        Node<FingerTree<Node<T>>>,
        )
}

enum Wrapper<T:'static> {
    Simple,
    Other(FingerTree<T>),
}

fn main() {
    let w = 
        Some(Wrapper::Simple::<u32>);
    
}

[matthiaskrgr]

Another one I think, this compiles fine as is with rustc but clippy stack overflows

#[derive(Debug)]
struct S<T> {
    t: T,
    s: Box<S<fn(u: T)>>,
}

fn main() {}