diff options
author | bors <bors@rust-lang.org> | 2017-11-05 09:11:45 +0000 |
---|---|---|
committer | bors <bors@rust-lang.org> | 2017-11-05 09:11:45 +0000 |
commit | 4efcc660f09ce3e83d194889f6d1161bf865f788 (patch) | |
tree | 687a9cd8774248d39bdca6df1f743f766bd99466 | |
parent | 16e9b9f15cc405cfccc4469216b8711abbeae9d5 (diff) | |
parent | 0d745af29a7566538277bd7a3b16faf09df7fe63 (diff) | |
download | rust-4efcc660f09ce3e83d194889f6d1161bf865f788.tar.gz |
Auto merge of #45754 - scottmcm:checked-npot, r=dtolnay
Fix #18604: next_power_of_two should panic on overflow
Fixes https://github.com/rust-lang/rust/issues/18604
Is it possible to write a test for this? My experiments showed `x.py test` running in release mode, so my attempt at a `#[should_panic]` didn't work.
-rw-r--r-- | src/libcore/num/mod.rs | 4 | ||||
-rw-r--r-- | src/test/run-pass/next-power-of-two-overflow-debug.rs | 36 | ||||
-rw-r--r-- | src/test/run-pass/next-power-of-two-overflow-ndebug.rs | 24 |
3 files changed, 63 insertions, 1 deletions
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs index 5799d37c19c..a50779bedfd 100644 --- a/src/libcore/num/mod.rs +++ b/src/libcore/num/mod.rs @@ -15,6 +15,7 @@ use convert::{Infallible, TryFrom}; use fmt; use intrinsics; +use ops; use str::FromStr; /// Provides intentionally-wrapped arithmetic on `T`. @@ -2223,7 +2224,8 @@ macro_rules! uint_impl { #[stable(feature = "rust1", since = "1.0.0")] #[inline] pub fn next_power_of_two(self) -> Self { - self.one_less_than_next_power_of_two() + 1 + // Call the trait to get overflow checks + ops::Add::add(self.one_less_than_next_power_of_two(), 1) } /// Returns the smallest power of two greater than or equal to `n`. If diff --git a/src/test/run-pass/next-power-of-two-overflow-debug.rs b/src/test/run-pass/next-power-of-two-overflow-debug.rs new file mode 100644 index 00000000000..a3e7ffd4e49 --- /dev/null +++ b/src/test/run-pass/next-power-of-two-overflow-debug.rs @@ -0,0 +1,36 @@ +// 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 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// compile-flags: -C debug_assertions=yes + +#![feature(i128_type)] + +use std::panic; + +fn main() { + macro_rules! overflow_test { + ($t:ident) => ( + let r = panic::catch_unwind(|| { + ($t::max_value()).next_power_of_two() + }); + assert!(r.is_err()); + + let r = panic::catch_unwind(|| { + (($t::max_value() >> 1) + 2).next_power_of_two() + }); + assert!(r.is_err()); + ) + } + overflow_test!(u8); + overflow_test!(u16); + overflow_test!(u32); + overflow_test!(u64); + overflow_test!(u128); +} diff --git a/src/test/run-pass/next-power-of-two-overflow-ndebug.rs b/src/test/run-pass/next-power-of-two-overflow-ndebug.rs new file mode 100644 index 00000000000..f8bcb961c68 --- /dev/null +++ b/src/test/run-pass/next-power-of-two-overflow-ndebug.rs @@ -0,0 +1,24 @@ +// 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 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// compile-flags: -C debug_assertions=no + +#![feature(i128_type)] + +fn main() { + for i in 129..256 { + assert_eq!((i as u8).next_power_of_two(), 0); + } + + assert_eq!(((1u16 << 15) + 1).next_power_of_two(), 0); + assert_eq!(((1u32 << 31) + 1).next_power_of_two(), 0); + assert_eq!(((1u64 << 63) + 1).next_power_of_two(), 0); + assert_eq!(((1u128 << 127) + 1).next_power_of_two(), 0); +} |