From 234e383c3426281447da140e24ccf6bf5402f6f5 Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Thu, 14 Mar 2024 15:08:53 -0700 Subject: [PATCH] Stabilize `unchecked_{add,sub,mul}` --- library/alloc/src/lib.rs | 1 - library/core/src/intrinsics.rs | 15 ++++---- library/core/src/lib.rs | 2 -- library/core/src/num/int_macros.rs | 48 ++++++++++++++++---------- library/core/src/num/uint_macros.rs | 48 ++++++++++++++++---------- library/core/src/ptr/const_ptr.rs | 2 -- library/core/src/ptr/mut_ptr.rs | 2 -- library/core/src/ptr/non_null.rs | 2 -- tests/ui/consts/const-int-unchecked.rs | 2 +- 9 files changed, 70 insertions(+), 52 deletions(-) diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs index ca504b05a96..b0609090a31 100644 --- a/library/alloc/src/lib.rs +++ b/library/alloc/src/lib.rs @@ -165,7 +165,6 @@ #![feature(try_trait_v2)] #![feature(try_with_capacity)] #![feature(tuple_trait)] -#![feature(unchecked_math)] #![feature(unicode_internals)] #![feature(unsize)] #![feature(utf8_chunks)] diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs index 86b9a39d68a..9b11a3cdbde 100644 --- a/library/core/src/intrinsics.rs +++ b/library/core/src/intrinsics.rs @@ -2224,24 +2224,27 @@ pub const fn unlikely(b: bool) -> bool { /// Returns the result of an unchecked addition, resulting in /// undefined behavior when `x + y > T::MAX` or `x + y < T::MIN`. /// - /// This intrinsic does not have a stable counterpart. - #[rustc_const_unstable(feature = "const_int_unchecked_arith", issue = "none")] + /// The stable counterpart of this intrinsic is `unchecked_add` on the various + /// integer types, such as [`u16::unchecked_add`] and [`i64::unchecked_add`]. + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[rustc_nounwind] pub fn unchecked_add(x: T, y: T) -> T; /// Returns the result of an unchecked subtraction, resulting in /// undefined behavior when `x - y > T::MAX` or `x - y < T::MIN`. /// - /// This intrinsic does not have a stable counterpart. - #[rustc_const_unstable(feature = "const_int_unchecked_arith", issue = "none")] + /// The stable counterpart of this intrinsic is `unchecked_sub` on the various + /// integer types, such as [`u16::unchecked_sub`] and [`i64::unchecked_sub`]. + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[rustc_nounwind] pub fn unchecked_sub(x: T, y: T) -> T; /// Returns the result of an unchecked multiplication, resulting in /// undefined behavior when `x * y > T::MAX` or `x * y < T::MIN`. /// - /// This intrinsic does not have a stable counterpart. - #[rustc_const_unstable(feature = "const_int_unchecked_arith", issue = "none")] + /// The stable counterpart of this intrinsic is `unchecked_mul` on the various + /// integer types, such as [`u16::unchecked_mul`] and [`i64::unchecked_mul`]. + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[rustc_nounwind] pub fn unchecked_mul(x: T, y: T) -> T; diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index 9b786feba89..5aeeacc4372 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -134,7 +134,6 @@ #![feature(const_heap)] #![feature(const_hint_assert_unchecked)] #![feature(const_index_range_slice_index)] -#![feature(const_int_unchecked_arith)] #![feature(const_intrinsic_copy)] #![feature(const_intrinsic_forget)] #![feature(const_ipv4)] @@ -193,7 +192,6 @@ #![feature(str_split_inclusive_remainder)] #![feature(str_split_remainder)] #![feature(strict_provenance)] -#![feature(unchecked_math)] #![feature(unchecked_shifts)] #![feature(utf16_extra)] #![feature(utf16_extra_const)] diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs index fa37ee4ffb2..9101d5064f9 100644 --- a/library/core/src/num/int_macros.rs +++ b/library/core/src/num/int_macros.rs @@ -492,21 +492,25 @@ pub const fn strict_add(self, rhs: Self) -> Self { /// Unchecked integer addition. Computes `self + rhs`, assuming overflow /// cannot occur. /// + /// Calling `x.unchecked_add(y)` is semantically equivalent to calling + /// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`. + /// + /// If you're just trying to avoid the panic in debug mode, then **do not** + /// use this. Instead, you're looking for [`wrapping_add`]. + /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_add`] would return `None`. /// + /// [`unwrap_unchecked`]: Option::unwrap_unchecked #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")] - #[unstable( - feature = "unchecked_math", - reason = "niche optimization path", - issue = "85122", - )] + #[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")] + #[stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_add(self, rhs: Self) -> Self { @@ -630,21 +634,25 @@ pub const fn strict_sub(self, rhs: Self) -> Self { /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow /// cannot occur. /// + /// Calling `x.unchecked_sub(y)` is semantically equivalent to calling + /// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`. + /// + /// If you're just trying to avoid the panic in debug mode, then **do not** + /// use this. Instead, you're looking for [`wrapping_sub`]. + /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_sub`] would return `None`. /// + /// [`unwrap_unchecked`]: Option::unwrap_unchecked #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")] - #[unstable( - feature = "unchecked_math", - reason = "niche optimization path", - issue = "85122", - )] + #[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")] + #[stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self { @@ -768,21 +776,25 @@ pub const fn strict_mul(self, rhs: Self) -> Self { /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow /// cannot occur. /// + /// Calling `x.unchecked_mul(y)` is semantically equivalent to calling + /// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`. + /// + /// If you're just trying to avoid the panic in debug mode, then **do not** + /// use this. Instead, you're looking for [`wrapping_mul`]. + /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_mul`] would return `None`. /// + /// [`unwrap_unchecked`]: Option::unwrap_unchecked #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")] - #[unstable( - feature = "unchecked_math", - reason = "niche optimization path", - issue = "85122", - )] + #[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")] + #[stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self { diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs index 081a3c0b118..c098f1894a6 100644 --- a/library/core/src/num/uint_macros.rs +++ b/library/core/src/num/uint_macros.rs @@ -500,21 +500,25 @@ pub const fn strict_add(self, rhs: Self) -> Self { /// Unchecked integer addition. Computes `self + rhs`, assuming overflow /// cannot occur. /// + /// Calling `x.unchecked_add(y)` is semantically equivalent to calling + /// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`. + /// + /// If you're just trying to avoid the panic in debug mode, then **do not** + /// use this. Instead, you're looking for [`wrapping_add`]. + /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_add`] would return `None`. /// + /// [`unwrap_unchecked`]: Option::unwrap_unchecked #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")] - #[unstable( - feature = "unchecked_math", - reason = "niche optimization path", - issue = "85122", - )] + #[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")] + #[stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_add(self, rhs: Self) -> Self { @@ -644,21 +648,25 @@ pub const fn strict_sub(self, rhs: Self) -> Self { /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow /// cannot occur. /// + /// Calling `x.unchecked_sub(y)` is semantically equivalent to calling + /// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`. + /// + /// If you're just trying to avoid the panic in debug mode, then **do not** + /// use this. Instead, you're looking for [`wrapping_sub`]. + /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_sub`] would return `None`. /// + /// [`unwrap_unchecked`]: Option::unwrap_unchecked #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")] - #[unstable( - feature = "unchecked_math", - reason = "niche optimization path", - issue = "85122", - )] + #[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")] + #[stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self { @@ -726,21 +734,25 @@ pub const fn strict_mul(self, rhs: Self) -> Self { /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow /// cannot occur. /// + /// Calling `x.unchecked_mul(y)` is semantically equivalent to calling + /// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`. + /// + /// If you're just trying to avoid the panic in debug mode, then **do not** + /// use this. Instead, you're looking for [`wrapping_mul`]. + /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_mul`] would return `None`. /// + /// [`unwrap_unchecked`]: Option::unwrap_unchecked #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")] - #[unstable( - feature = "unchecked_math", - reason = "niche optimization path", - issue = "85122", - )] + #[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")] + #[stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] + #[rustc_const_stable(feature = "unchecked_math", since = "CURRENT_RUSTC_VERSION")] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self { diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs index a0c04d3f65d..a49c6e9d815 100644 --- a/library/core/src/ptr/const_ptr.rs +++ b/library/core/src/ptr/const_ptr.rs @@ -1038,8 +1038,6 @@ pub const fn guaranteed_ne(self, other: *const T) -> Option #[stable(feature = "pointer_methods", since = "1.26.0")] #[must_use = "returns a new pointer rather than modifying its argument"] #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")] - // We could always go back to wrapping if unchecked becomes unacceptable - #[rustc_allow_const_fn_unstable(const_int_unchecked_arith)] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn sub(self, count: usize) -> Self diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs index 6a9033a144d..bfb99630aa9 100644 --- a/library/core/src/ptr/mut_ptr.rs +++ b/library/core/src/ptr/mut_ptr.rs @@ -1123,8 +1123,6 @@ pub const fn guaranteed_ne(self, other: *mut T) -> Option #[stable(feature = "pointer_methods", since = "1.26.0")] #[must_use = "returns a new pointer rather than modifying its argument"] #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")] - // We could always go back to wrapping if unchecked becomes unacceptable - #[rustc_allow_const_fn_unstable(const_int_unchecked_arith)] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn sub(self, count: usize) -> Self diff --git a/library/core/src/ptr/non_null.rs b/library/core/src/ptr/non_null.rs index 9c0236c172a..0bde64adda4 100644 --- a/library/core/src/ptr/non_null.rs +++ b/library/core/src/ptr/non_null.rs @@ -702,8 +702,6 @@ pub const fn cast(self) -> NonNull { #[unstable(feature = "non_null_convenience", issue = "117691")] #[rustc_const_unstable(feature = "non_null_convenience", issue = "117691")] #[must_use = "returns a new pointer rather than modifying its argument"] - // We could always go back to wrapping if unchecked becomes unacceptable - #[rustc_allow_const_fn_unstable(const_int_unchecked_arith)] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn sub(self, count: usize) -> Self diff --git a/tests/ui/consts/const-int-unchecked.rs b/tests/ui/consts/const-int-unchecked.rs index 902a668488b..3fe96c2de23 100644 --- a/tests/ui/consts/const-int-unchecked.rs +++ b/tests/ui/consts/const-int-unchecked.rs @@ -1,5 +1,5 @@ #![feature(core_intrinsics)] -#![feature(const_int_unchecked_arith)] + use std::intrinsics;