From 768cbbcd9e21c75565dad4714346b0d0028d331c Mon Sep 17 00:00:00 2001 From: varkor Date: Fri, 19 Jan 2018 19:58:46 +0000 Subject: Fix type inhabitedness check for arrays Arrays of uninhabited types were considered to also be uninhabited if their length had not been evaluated, causing unsoundness. --- src/test/compile-fail/empty-never-array.rs | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 src/test/compile-fail/empty-never-array.rs (limited to 'src/test/compile-fail/empty-never-array.rs') diff --git a/src/test/compile-fail/empty-never-array.rs b/src/test/compile-fail/empty-never-array.rs new file mode 100644 index 00000000000..1dc45a1a884 --- /dev/null +++ b/src/test/compile-fail/empty-never-array.rs @@ -0,0 +1,26 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![feature(never_type)] + +enum Helper { + T(T, [!; 0]), + #[allow(dead_code)] + U(U), +} + +fn transmute(t: T) -> U { + let Helper::U(u) = Helper::T(t, []); //~ ERROR refutable pattern in local binding: `T(_, _)` not covered + u +} + +fn main() { + println!("{:?}", transmute::<&str, (*const u8, u64)>("type safety")); +} -- cgit 1.4.1-3-g733a5 From c4d0bb398b548dafba2346f3f3be9284909643f0 Mon Sep 17 00:00:00 2001 From: varkor Date: Fri, 19 Jan 2018 21:00:35 +0000 Subject: Fix tidy error --- src/librustc/ty/inhabitedness/mod.rs | 2 +- src/test/compile-fail/empty-never-array.rs | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) (limited to 'src/test/compile-fail/empty-never-array.rs') diff --git a/src/librustc/ty/inhabitedness/mod.rs b/src/librustc/ty/inhabitedness/mod.rs index 8cf5b431cf1..93e4cd9adf8 100644 --- a/src/librustc/ty/inhabitedness/mod.rs +++ b/src/librustc/ty/inhabitedness/mod.rs @@ -263,9 +263,9 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> { }, TyArray(ty, len) => { match len.val.to_const_int().and_then(|i| i.to_u64()) { - Some(n) if n != 0 => ty.uninhabited_from(visited, tcx), // If the array is definitely non-empty, it's uninhabited if // the type of its elements is uninhabited. + Some(n) if n != 0 => ty.uninhabited_from(visited, tcx), _ => DefIdForest::empty() } } diff --git a/src/test/compile-fail/empty-never-array.rs b/src/test/compile-fail/empty-never-array.rs index 1dc45a1a884..53b24e17319 100644 --- a/src/test/compile-fail/empty-never-array.rs +++ b/src/test/compile-fail/empty-never-array.rs @@ -17,7 +17,8 @@ enum Helper { } fn transmute(t: T) -> U { - let Helper::U(u) = Helper::T(t, []); //~ ERROR refutable pattern in local binding: `T(_, _)` not covered + let Helper::U(u) = Helper::T(t, []); + //~^ ERROR refutable pattern in local binding: `T(_, _)` not covered u } -- cgit 1.4.1-3-g733a5