gccrs enters infinite loop/hangs when compiling match patterns with macros or tuple structs

[starbugs-qurong]

Summary

When compiling code containing match expressions with a macro-expanded tuple struct pattern (ApplicationTy(TypeCtor::X)) or equivalent OR patterns, gccrs fails to terminate and gets killed (SIGKILL). The same code compiles successfully with rustc (only warnings about dead code).

Reproducer

I tried this code:

#![deny(unreachable_patterns)]
pub enum TypeCtor { Slice, Array }
pub struct ApplicationTy(TypeCtor);

macro_rules! ty_app { ($ctor:pat) => { ApplicationTy($ctor) }; }

fn _foo(ty: ApplicationTy) {
    match ty { ty_app!(TypeCtor::Array) | ty_app!(TypeCtor::Slice) => {} }
    // Expanded version also crashes:
    // match ty { ApplicationTy(TypeCtor::Array) | ApplicationTy(TypeCtor::Slice) => {} }
}

fn main() {}

Does the code make use of any (1.49) nightly feature ?

• [ ] Nightly

Godbolt link

https://godbolt.org/z/fT6r9EKso

Actual behavior

Compiler hangs indefinitely and gets terminated with SIGKILL (exit code 143).

Expected behavior

Successful compilation with warnings about unused fields/functions.

GCC Version

14.2