segmentation fault

[wxie7]

I tried this code:

rustc --crate-type staticlib -C link-dead-code -C debuginfo=2 file.rs

use std::mem::ManuallyDrop;
pub enum Foo<U> {
    Leaf(U),
    Branch(BoxedFoo<BoxedFoo<U>>),
}
pub type BoxedFoo<U> = ManuallyDrop<Box<Foo<U>>>;
pub fn drop() -> Foo<usize> {
    todo!()
}

Meta

rustc --version --verbose:

rustc 1.85.0-nightly (acabb5248 2024-12-04)
binary: rustc
commit-hash: acabb5248231987ae1f0c215208d1005a5db402d
commit-date: 2024-12-04
host: x86_64-unknown-linux-gnu
release: 1.85.0-nightly
LLVM version: 19.1.5

Backtrace

warning: variant `Recursive` is never constructed
 --> mutant.rs:3:5
  |
1 | enum Foo<T: 'static> {
  |      --- variant in this enum
2 |     Value(T),
3 |     Recursive(&'static Foo<Option<T>>),
  |     ^^^^^^^^^
  |
  = note: `#[warn(dead_code)]` on by default

error: rustc interrupted by SIGSEGV, printing backtrace

/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x36d7fa3)[0x7926f32d7fa3]
/lib/x86_64-linux-gnu/libc.so.6(+0x42520)[0x7926ef842520]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(_RNvNtNtCskYQ3m3XnxIX_17rustc_codegen_ssa9debuginfo10type_names14push_item_name+0x9)[0x7926f4812b09]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(_RNvNtNtCskYQ3m3XnxIX_17rustc_codegen_ssa9debuginfo10type_names14push_item_name+0x1b3)[0x7926f4812cb3]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(_RNvNtNtCskYQ3m3XnxIX_17rustc_codegen_ssa9debuginfo10type_names14push_item_name+0x1b3)[0x7926f4812cb3]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x5198b39)[0x7926f4d98b39]

### cycle encountered after 6 frames with period 7
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
### recursed 35 times

/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]
/home/xieym/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-0e1744037f1f9b04.so(+0x519827d)[0x7926f4d9827d]

note: rustc unexpectedly overflowed its stack! this is a bug
note: maximum backtrace depth reached, frames may have been lost
note: we would appreciate a report at https://github.com/rust-lang/rust
help: you can increase rustc's stack size by setting RUST_MIN_STACK=16777216
note: backtrace dumped due to SIGSEGV! resuming signal
[1]    430090 segmentation fault (core dumped)  rustc -C link-dead-code -C debuginfo=2 mutant.rs

[saethlin]

I'm pretty sure that this is a duplicate of #133920. These two examples are just using different ways to get a recursive type through the other parts of the compiler that normally fall over on them, then using different mechanisms to expose the type to debuginfo generation. Either constructing one in fn main in a bin crate, or using one in a function signature with -Clink-dead-code.