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// check-pass
// compile-flags: --emit=mir,link -O
// At one point the MIR inlining, when guarding against infinitely (or even just
// excessive) recursion, was using `ty::Instance` as the basis for its history
// check. The problem is that when you have polymorphic recursion, you can have
// distinct instances of the same code (because you're inlining the same code
// with differing substitutions), causing the amount of inlining to blow up
// exponentially.
//
// This test illustrates an example of that filed in issue rust#100476.
#![allow(unconditional_recursion)]
#![feature(decl_macro)]
macro emit($($m:ident)*) {$(
// Randomize `def_path_hash` by defining them under a module with
// different names
pub mod $m {
pub trait Tr {
type Next: Tr;
}
pub fn hoge<const N: usize, T: Tr>() {
inner::<N, T>();
}
#[inline(always)]
fn inner<const N: usize, T: Tr>() {
inner::<N, T::Next>();
}
}
)*}
// Increase the chance of triggering the bug
emit!(
m00 m01 m02 m03 m04 m05 m06 m07 m08 m09
m10 m11 m12 m13 m14 m15 m16 m17 m18 m19
);
fn main() { }
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