gcc/testsuite/rust/compile/issues/4090-2.rs

#![feature(no_core)]
#![no_core]
#![feature(lang_items)]

mod marker {
    #[lang = "sized"]
    pub trait Sized {}

    #[lang = "phantom_data"]
    #[stable(feature = "rust1", since = "1.0.0")]
    pub struct PhantomData<T: ?Sized>;

    #[unstable(feature = "structural_match", issue = "31434")]
    #[lang = "structural_teq"]
    pub trait StructuralEq {
        // Empty.
    }

    #[unstable(feature = "structural_match", issue = "31434")]
    #[lang = "structural_peq"]
    pub trait StructuralPartialEq {
        // Empty.
    }
}

pub mod cmp {
    use super::marker::Sized;

    #[lang = "eq"]
    pub trait PartialEq<Rhs: ?Sized = Self> {
        fn eq(&self, other: &Rhs) -> bool;

        fn ne(&self, other: &Rhs) -> bool {
            !self.eq(other)
        }
    }

    pub trait Eq: PartialEq<Self> {
        fn assert_receiver_is_total_eq(&self) {}
    }
}

pub mod ptr {

    use super::cmp::{Eq, PartialEq};

    macro_rules! fnptr_impls_safety_abi {
            ($FnTy: ty, $($Arg: ident),*) => {
                #[stable(feature = "fnptr_impls", since = "1.4.0")]
                impl<Ret, $($Arg),*> PartialEq for $FnTy {
                    #[inline]
                    fn eq(&self, other: &Self) -> bool {
                        *self as usize == *other as usize
                    }
                }

                #[stable(feature = "fnptr_impls", since = "1.4.0")]
                impl<Ret, $($Arg),*> Eq for $FnTy {}

            }
        }

    fnptr_impls_safety_abi! { extern "Rust" fn() -> Ret, }
    fnptr_impls_safety_abi! { extern "C" fn() -> Ret, }
    fnptr_impls_safety_abi! { unsafe extern "Rust" fn() -> Ret, }
    fnptr_impls_safety_abi! { unsafe extern "C" fn() -> Ret, }
}

#[derive(PartialEq, Eq)]
struct AllowedBelow {
    // { dg-warning "struct is never constructed" "" { target *-*-* } .-1 }
    f: fn(),
}