From 64d98f8ee037282c35007b64c2649055c56af1db Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:03 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- tests/ui/nll/mir_check_cast_reify.rs | 39 ++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 tests/ui/nll/mir_check_cast_reify.rs (limited to 'tests/ui/nll/mir_check_cast_reify.rs') diff --git a/tests/ui/nll/mir_check_cast_reify.rs b/tests/ui/nll/mir_check_cast_reify.rs new file mode 100644 index 000000000..951459911 --- /dev/null +++ b/tests/ui/nll/mir_check_cast_reify.rs @@ -0,0 +1,39 @@ +#![allow(dead_code)] + +// Test that we relate the type of the fn type to the type of the fn +// ptr when doing a `ReifyFnPointer` cast. +// +// This test is a bit tortured, let me explain: +// + +// The `where 'a: 'a` clause here ensures that `'a` is early bound, +// which is needed below to ensure that this test hits the path we are +// concerned with. +fn foo<'a>(x: &'a u32) -> &'a u32 +where + 'a: 'a, +{ + panic!() +} + +fn bar<'a>(x: &'a u32) -> &'static u32 { + // Here, the type of `foo` is `typeof(foo::<'x>)` for some fresh variable `'x`. + // During NLL region analysis, this will get renumbered to `typeof(foo::<'?0>)` + // where `'?0` is a new region variable. + // + // (Note that if `'a` on `foo` were late-bound, the type would be + // `typeof(foo)`, which would interact differently with because + // the renumbering later.) + // + // This type is then coerced to a fn type `fn(&'?1 u32) -> &'?2 + // u32`. Here, the `'?1` and `'?2` will have been created during + // the NLL region renumbering. + // + // The MIR type checker must therefore relate `'?0` to `'?1` and `'?2` + // as part of checking the `ReifyFnPointer`. + let f: fn(_) -> _ = foo; + f(x) + //~^ ERROR lifetime may not live long enough +} + +fn main() {} -- cgit v1.2.3