From 52063ae24860bb5cb3abc6f3dd83904bc18a3b0f Mon Sep 17 00:00:00 2001 From: Hanna Kruppe Date: Sun, 10 Aug 2025 11:21:43 +0200 Subject: stabilize path_add_extension --- library/std/src/path.rs | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'library/std/src') diff --git a/library/std/src/path.rs b/library/std/src/path.rs index 3b52804d6be..2af6249f3b9 100644 --- a/library/std/src/path.rs +++ b/library/std/src/path.rs @@ -1575,8 +1575,6 @@ impl PathBuf { /// # Examples /// /// ``` - /// #![feature(path_add_extension)] - /// /// use std::path::{Path, PathBuf}; /// /// let mut p = PathBuf::from("/feel/the"); @@ -1596,7 +1594,7 @@ impl PathBuf { /// p.add_extension(""); /// assert_eq!(Path::new("/feel/the.formatted.dark"), p.as_path()); /// ``` - #[unstable(feature = "path_add_extension", issue = "127292")] + #[stable(feature = "path_add_extension", since = "CURRENT_RUSTC_VERSION")] pub fn add_extension>(&mut self, extension: S) -> bool { self._add_extension(extension.as_ref()) } @@ -2846,8 +2844,6 @@ impl Path { /// # Examples /// /// ``` - /// #![feature(path_add_extension)] - /// /// use std::path::{Path, PathBuf}; /// /// let path = Path::new("foo.rs"); @@ -2858,7 +2854,7 @@ impl Path { /// assert_eq!(path.with_added_extension("xz"), PathBuf::from("foo.tar.gz.xz")); /// assert_eq!(path.with_added_extension("").with_added_extension("txt"), PathBuf::from("foo.tar.gz.txt")); /// ``` - #[unstable(feature = "path_add_extension", issue = "127292")] + #[stable(feature = "path_add_extension", since = "CURRENT_RUSTC_VERSION")] pub fn with_added_extension>(&self, extension: S) -> PathBuf { let mut new_path = self.to_path_buf(); new_path.add_extension(extension); -- cgit 1.4.1-3-g733a5 From 62b4347e80cc86314bd98749e95eff8cdf8ef005 Mon Sep 17 00:00:00 2001 From: sayantn Date: Thu, 21 Aug 2025 04:47:05 +0530 Subject: Add `funnel_sh{l,r}` functions and intrinsics - Add a fallback implementation for the intrinsics - Add LLVM backend support for funnel shifts Co-Authored-By: folkertdev --- compiler/rustc_codegen_llvm/src/intrinsic.rs | 26 +++++--- compiler/rustc_hir_analysis/src/check/intrinsic.rs | 3 + compiler/rustc_span/src/symbol.rs | 2 + library/core/src/intrinsics/fallback.rs | 73 ++++++++++++++++++++++ library/core/src/intrinsics/mod.rs | 55 ++++++++++++++++ library/core/src/lib.rs | 1 + library/core/src/num/mod.rs | 24 +++++++ library/core/src/num/uint_macros.rs | 73 ++++++++++++++++++++++ library/coretests/tests/lib.rs | 1 + library/coretests/tests/num/uint_macros.rs | 36 +++++++++++ library/std/src/lib.rs | 1 + src/tools/miri/tests/fail/intrinsics/funnel_shl.rs | 7 +++ .../miri/tests/fail/intrinsics/funnel_shl.stderr | 15 +++++ src/tools/miri/tests/fail/intrinsics/funnel_shr.rs | 7 +++ .../miri/tests/fail/intrinsics/funnel_shr.stderr | 15 +++++ src/tools/miri/tests/pass/intrinsics/integer.rs | 8 ++- 16 files changed, 338 insertions(+), 9 deletions(-) create mode 100644 src/tools/miri/tests/fail/intrinsics/funnel_shl.rs create mode 100644 src/tools/miri/tests/fail/intrinsics/funnel_shl.stderr create mode 100644 src/tools/miri/tests/fail/intrinsics/funnel_shr.rs create mode 100644 src/tools/miri/tests/fail/intrinsics/funnel_shr.stderr (limited to 'library/std/src') diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs index 49d3dedbeab..85f71f331a4 100644 --- a/compiler/rustc_codegen_llvm/src/intrinsic.rs +++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs @@ -383,7 +383,9 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> { | sym::rotate_left | sym::rotate_right | sym::saturating_add - | sym::saturating_sub => { + | sym::saturating_sub + | sym::unchecked_funnel_shl + | sym::unchecked_funnel_shr => { let ty = args[0].layout.ty; if !ty.is_integral() { tcx.dcx().emit_err(InvalidMonomorphization::BasicIntegerType { @@ -424,18 +426,26 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> { sym::bitreverse => { self.call_intrinsic("llvm.bitreverse", &[llty], &[args[0].immediate()]) } - sym::rotate_left | sym::rotate_right => { - let is_left = name == sym::rotate_left; - let val = args[0].immediate(); - let raw_shift = args[1].immediate(); - // rotate = funnel shift with first two args the same + sym::rotate_left + | sym::rotate_right + | sym::unchecked_funnel_shl + | sym::unchecked_funnel_shr => { + let is_left = name == sym::rotate_left || name == sym::unchecked_funnel_shl; + let lhs = args[0].immediate(); + let (rhs, raw_shift) = + if name == sym::rotate_left || name == sym::rotate_right { + // rotate = funnel shift with first two args the same + (lhs, args[1].immediate()) + } else { + (args[1].immediate(), args[2].immediate()) + }; let llvm_name = format!("llvm.fsh{}", if is_left { 'l' } else { 'r' }); // llvm expects shift to be the same type as the values, but rust // always uses `u32`. - let raw_shift = self.intcast(raw_shift, self.val_ty(val), false); + let raw_shift = self.intcast(raw_shift, self.val_ty(lhs), false); - self.call_intrinsic(llvm_name, &[llty], &[val, val, raw_shift]) + self.call_intrinsic(llvm_name, &[llty], &[lhs, rhs, raw_shift]) } sym::saturating_add | sym::saturating_sub => { let is_add = name == sym::saturating_add; diff --git a/compiler/rustc_hir_analysis/src/check/intrinsic.rs b/compiler/rustc_hir_analysis/src/check/intrinsic.rs index cfc6bc2f3a0..aa2d27ab809 100644 --- a/compiler/rustc_hir_analysis/src/check/intrinsic.rs +++ b/compiler/rustc_hir_analysis/src/check/intrinsic.rs @@ -449,6 +449,9 @@ pub(crate) fn check_intrinsic_type( } sym::unchecked_shl | sym::unchecked_shr => (2, 0, vec![param(0), param(1)], param(0)), sym::rotate_left | sym::rotate_right => (1, 0, vec![param(0), tcx.types.u32], param(0)), + sym::unchecked_funnel_shl | sym::unchecked_funnel_shr => { + (1, 0, vec![param(0), param(0), tcx.types.u32], param(0)) + } sym::unchecked_add | sym::unchecked_sub | sym::unchecked_mul => { (1, 0, vec![param(0), param(0)], param(0)) } diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index dcb1becc957..64662d48137 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -2269,6 +2269,8 @@ symbols! { unboxed_closures, unchecked_add, unchecked_div, + unchecked_funnel_shl, + unchecked_funnel_shr, unchecked_mul, unchecked_rem, unchecked_shl, diff --git a/library/core/src/intrinsics/fallback.rs b/library/core/src/intrinsics/fallback.rs index eec5c4d646d..96928325328 100644 --- a/library/core/src/intrinsics/fallback.rs +++ b/library/core/src/intrinsics/fallback.rs @@ -148,3 +148,76 @@ impl_disjoint_bitor! { u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, } + +#[const_trait] +#[rustc_const_unstable(feature = "core_intrinsics_fallbacks", issue = "none")] +pub trait FunnelShift: Copy + 'static { + /// See [`super::unchecked_funnel_shl`]; we just need the trait indirection to handle + /// different types since calling intrinsics with generics doesn't work. + unsafe fn unchecked_funnel_shl(self, rhs: Self, shift: u32) -> Self; + + /// See [`super::unchecked_funnel_shr`]; we just need the trait indirection to handle + /// different types since calling intrinsics with generics doesn't work. + unsafe fn unchecked_funnel_shr(self, rhs: Self, shift: u32) -> Self; +} + +macro_rules! impl_funnel_shifts { + ($($type:ident),*) => {$( + #[rustc_const_unstable(feature = "core_intrinsics_fallbacks", issue = "none")] + impl const FunnelShift for $type { + #[cfg_attr(miri, track_caller)] + #[inline] + unsafe fn unchecked_funnel_shl(self, rhs: Self, shift: u32) -> Self { + // This implementation is also used by Miri so we have to check the precondition. + // SAFETY: this is guaranteed by the caller + unsafe { super::assume(shift < $type::BITS) }; + if shift == 0 { + self + } else { + // SAFETY: + // - `shift < T::BITS`, which satisfies `unchecked_shl` + // - this also ensures that `T::BITS - shift < T::BITS` (shift = 0 is checked + // above), which satisfies `unchecked_shr` + // - because the types are unsigned, the combination are disjoint bits (this is + // not true if they're signed, since SHR will fill in the empty space with a + // sign bit, not zero) + unsafe { + super::disjoint_bitor( + super::unchecked_shl(self, shift), + super::unchecked_shr(rhs, $type::BITS - shift), + ) + } + } + } + + #[cfg_attr(miri, track_caller)] + #[inline] + unsafe fn unchecked_funnel_shr(self, rhs: Self, shift: u32) -> Self { + // This implementation is also used by Miri so we have to check the precondition. + // SAFETY: this is guaranteed by the caller + unsafe { super::assume(shift < $type::BITS) }; + if shift == 0 { + rhs + } else { + // SAFETY: + // - `shift < T::BITS`, which satisfies `unchecked_shr` + // - this also ensures that `T::BITS - shift < T::BITS` (shift = 0 is checked + // above), which satisfies `unchecked_shl` + // - because the types are unsigned, the combination are disjoint bits (this is + // not true if they're signed, since SHR will fill in the empty space with a + // sign bit, not zero) + unsafe { + super::disjoint_bitor( + super::unchecked_shl(self, $type::BITS - shift), + super::unchecked_shr(rhs, shift), + ) + } + } + } + } + )*}; +} + +impl_funnel_shifts! { + u8, u16, u32, u64, u128, usize +} diff --git a/library/core/src/intrinsics/mod.rs b/library/core/src/intrinsics/mod.rs index 904aa52c784..bffffbc29c1 100644 --- a/library/core/src/intrinsics/mod.rs +++ b/library/core/src/intrinsics/mod.rs @@ -2102,6 +2102,61 @@ pub const fn saturating_add(a: T, b: T) -> T; #[rustc_intrinsic] pub const fn saturating_sub(a: T, b: T) -> T; +/// Funnel Shift left. +/// +/// Concatenates `a` and `b` (with `a` in the most significant half), +/// creating an integer twice as wide. Then shift this integer left +/// by `shift`), and extract the most significant half. If `a` and `b` +/// are the same, this is equivalent to a rotate left operation. +/// +/// It is undefined behavior if `shift` is greater than or equal to the +/// bit size of `T`. +/// +/// Safe versions of this intrinsic are available on the integer primitives +/// via the `funnel_shl` method. For example, [`u32::funnel_shl`]. +#[rustc_intrinsic] +#[rustc_nounwind] +#[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")] +#[unstable(feature = "funnel_shifts", issue = "145686")] +#[track_caller] +#[miri::intrinsic_fallback_is_spec] +pub const unsafe fn unchecked_funnel_shl( + a: T, + b: T, + shift: u32, +) -> T { + // SAFETY: caller ensures that `shift` is in-range + unsafe { a.unchecked_funnel_shl(b, shift) } +} + +/// Funnel Shift right. +/// +/// Concatenates `a` and `b` (with `a` in the most significant half), +/// creating an integer twice as wide. Then shift this integer right +/// by `shift` (taken modulo the bit size of `T`), and extract the +/// least significant half. If `a` and `b` are the same, this is equivalent +/// to a rotate right operation. +/// +/// It is undefined behavior if `shift` is greater than or equal to the +/// bit size of `T`. +/// +/// Safer versions of this intrinsic are available on the integer primitives +/// via the `funnel_shr` method. For example, [`u32::funnel_shr`] +#[rustc_intrinsic] +#[rustc_nounwind] +#[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")] +#[unstable(feature = "funnel_shifts", issue = "145686")] +#[track_caller] +#[miri::intrinsic_fallback_is_spec] +pub const unsafe fn unchecked_funnel_shr( + a: T, + b: T, + shift: u32, +) -> T { + // SAFETY: caller ensures that `shift` is in-range + unsafe { a.unchecked_funnel_shr(b, shift) } +} + /// This is an implementation detail of [`crate::ptr::read`] and should /// not be used anywhere else. See its comments for why this exists. /// diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index 71abd707374..fb6cacb0e00 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -156,6 +156,7 @@ #![feature(f128)] #![feature(freeze_impls)] #![feature(fundamental)] +#![feature(funnel_shifts)] #![feature(if_let_guard)] #![feature(intra_doc_pointers)] #![feature(intrinsics)] diff --git a/library/core/src/num/mod.rs b/library/core/src/num/mod.rs index acfe38b7a37..e2987b0b7e5 100644 --- a/library/core/src/num/mod.rs +++ b/library/core/src/num/mod.rs @@ -454,6 +454,9 @@ impl u8 { rot = 2, rot_op = "0x82", rot_result = "0xa", + fsh_op = "0x36", + fshl_result = "0x8", + fshr_result = "0x8d", swap_op = "0x12", swapped = "0x12", reversed = "0x48", @@ -1088,6 +1091,9 @@ impl u16 { rot = 4, rot_op = "0xa003", rot_result = "0x3a", + fsh_op = "0x2de", + fshl_result = "0x30", + fshr_result = "0x302d", swap_op = "0x1234", swapped = "0x3412", reversed = "0x2c48", @@ -1135,6 +1141,9 @@ impl u32 { rot = 8, rot_op = "0x10000b3", rot_result = "0xb301", + fsh_op = "0x2fe78e45", + fshl_result = "0xb32f", + fshr_result = "0xb32fe78e", swap_op = "0x12345678", swapped = "0x78563412", reversed = "0x1e6a2c48", @@ -1158,6 +1167,9 @@ impl u64 { rot = 12, rot_op = "0xaa00000000006e1", rot_result = "0x6e10aa", + fsh_op = "0x2fe78e45983acd98", + fshl_result = "0x6e12fe", + fshr_result = "0x6e12fe78e45983ac", swap_op = "0x1234567890123456", swapped = "0x5634129078563412", reversed = "0x6a2c48091e6a2c48", @@ -1181,6 +1193,9 @@ impl u128 { rot = 16, rot_op = "0x13f40000000000000000000000004f76", rot_result = "0x4f7613f4", + fsh_op = "0x2fe78e45983acd98039000008736273", + fshl_result = "0x4f7602fe", + fshr_result = "0x4f7602fe78e45983acd9803900000873", swap_op = "0x12345678901234567890123456789012", swapped = "0x12907856341290785634129078563412", reversed = "0x48091e6a2c48091e6a2c48091e6a2c48", @@ -1207,6 +1222,9 @@ impl usize { rot = 4, rot_op = "0xa003", rot_result = "0x3a", + fsh_op = "0x2fe78e45983acd98039000008736273", + fshl_result = "0x4f7602fe", + fshr_result = "0x4f7602fe78e45983acd9803900000873", swap_op = "0x1234", swapped = "0x3412", reversed = "0x2c48", @@ -1231,6 +1249,9 @@ impl usize { rot = 8, rot_op = "0x10000b3", rot_result = "0xb301", + fsh_op = "0x2fe78e45", + fshl_result = "0xb32f", + fshr_result = "0xb32fe78e", swap_op = "0x12345678", swapped = "0x78563412", reversed = "0x1e6a2c48", @@ -1255,6 +1276,9 @@ impl usize { rot = 12, rot_op = "0xaa00000000006e1", rot_result = "0x6e10aa", + fsh_op = "0x2fe78e45983acd98", + fshl_result = "0x6e12fe", + fshr_result = "0x6e12fe78e45983ac", swap_op = "0x1234567890123456", swapped = "0x5634129078563412", reversed = "0x6a2c48091e6a2c48", diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs index 10d9498d15e..1fef3c822b7 100644 --- a/library/core/src/num/uint_macros.rs +++ b/library/core/src/num/uint_macros.rs @@ -14,6 +14,9 @@ macro_rules! uint_impl { rot = $rot:literal, rot_op = $rot_op:literal, rot_result = $rot_result:literal, + fsh_op = $fsh_op:literal, + fshl_result = $fshl_result:literal, + fshr_result = $fshr_result:literal, swap_op = $swap_op:literal, swapped = $swapped:literal, reversed = $reversed:literal, @@ -375,6 +378,76 @@ macro_rules! uint_impl { return intrinsics::rotate_right(self, n); } + /// Performs a left funnel shift (concatenates `self` with `rhs`, with `self` + /// making up the most significant half, then shifts the combined value left + /// by `n`, and most significant half is extracted to produce the result). + /// + /// Please note this isn't the same operation as the `<<` shifting operator or + /// [`rotate_left`](Self::rotate_left), although `a.funnel_shl(a, n)` is *equivalent* + /// to `a.rotate_left(n)`. + /// + /// # Panics + /// + /// If `n` is greater than or equal to the number of bits in `self` + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(funnel_shifts)] + #[doc = concat!("let a = ", $rot_op, stringify!($SelfT), ";")] + #[doc = concat!("let b = ", $fsh_op, stringify!($SelfT), ";")] + #[doc = concat!("let m = ", $fshl_result, ";")] + /// + #[doc = concat!("assert_eq!(a.funnel_shl(b, ", $rot, "), m);")] + /// ``` + #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")] + #[unstable(feature = "funnel_shifts", issue = "145686")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn funnel_shl(self, rhs: Self, n: u32) -> Self { + assert!(n < Self::BITS, "attempt to funnel shift left with overflow"); + // SAFETY: just checked that `shift` is in-range + unsafe { intrinsics::unchecked_funnel_shl(self, rhs, n) } + } + + /// Performs a right funnel shift (concatenates `self` and `rhs`, with `self` + /// making up the most significant half, then shifts the combined value right + /// by `n`, and least significant half is extracted to produce the result). + /// + /// Please note this isn't the same operation as the `>>` shifting operator or + /// [`rotate_right`](Self::rotate_right), although `a.funnel_shr(a, n)` is *equivalent* + /// to `a.rotate_right(n)`. + /// + /// # Panics + /// + /// If `n` is greater than or equal to the number of bits in `self` + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(funnel_shifts)] + #[doc = concat!("let a = ", $rot_op, stringify!($SelfT), ";")] + #[doc = concat!("let b = ", $fsh_op, stringify!($SelfT), ";")] + #[doc = concat!("let m = ", $fshr_result, ";")] + /// + #[doc = concat!("assert_eq!(a.funnel_shr(b, ", $rot, "), m);")] + /// ``` + #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")] + #[unstable(feature = "funnel_shifts", issue = "145686")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn funnel_shr(self, rhs: Self, n: u32) -> Self { + assert!(n < Self::BITS, "attempt to funnel shift right with overflow"); + // SAFETY: just checked that `shift` is in-range + unsafe { intrinsics::unchecked_funnel_shr(self, rhs, n) } + } + /// Reverses the byte order of the integer. /// /// # Examples diff --git a/library/coretests/tests/lib.rs b/library/coretests/tests/lib.rs index d2281b1df2f..c16c344776d 100644 --- a/library/coretests/tests/lib.rs +++ b/library/coretests/tests/lib.rs @@ -50,6 +50,7 @@ #![feature(fmt_internals)] #![feature(formatting_options)] #![feature(freeze)] +#![feature(funnel_shifts)] #![feature(future_join)] #![feature(generic_assert_internals)] #![feature(hasher_prefixfree_extras)] diff --git a/library/coretests/tests/num/uint_macros.rs b/library/coretests/tests/num/uint_macros.rs index c7d10ea4d88..63be8a45b5c 100644 --- a/library/coretests/tests/num/uint_macros.rs +++ b/library/coretests/tests/num/uint_macros.rs @@ -104,6 +104,19 @@ macro_rules! uint_module { assert_eq_const_safe!($T: C.rotate_left(128), C); } + fn test_funnel_shift() { + // Shifting by 0 should have no effect + assert_eq_const_safe!($T: <$T>::funnel_shl(A, B, 0), A); + assert_eq_const_safe!($T: <$T>::funnel_shr(A, B, 0), B); + + assert_eq_const_safe!($T: <$T>::funnel_shl(_0, _1, 4), 0b1111); + assert_eq_const_safe!($T: <$T>::funnel_shr(_0, _1, 4), _1 >> 4); + assert_eq_const_safe!($T: <$T>::funnel_shl(_1, _0, 4), _1 << 4); + + assert_eq_const_safe!($T: <$T>::funnel_shl(_1, _1, 4), <$T>::rotate_left(_1, 4)); + assert_eq_const_safe!($T: <$T>::funnel_shr(_1, _1, 4), <$T>::rotate_right(_1, 4)); + } + fn test_swap_bytes() { assert_eq_const_safe!($T: A.swap_bytes().swap_bytes(), A); assert_eq_const_safe!($T: B.swap_bytes().swap_bytes(), B); @@ -150,6 +163,29 @@ macro_rules! uint_module { } } + #[test] + #[should_panic = "attempt to funnel shift left with overflow"] + fn test_funnel_shl_overflow() { + let _ = <$T>::funnel_shl(A, B, $T::BITS); + } + + #[test] + #[should_panic = "attempt to funnel shift right with overflow"] + fn test_funnel_shr_overflow() { + let _ = <$T>::funnel_shr(A, B, $T::BITS); + } + + #[test] + fn test_funnel_shifts_runtime() { + for i in 0..$T::BITS - 1 { + assert_eq!(<$T>::funnel_shl(A, 0, i), A << i); + assert_eq!(<$T>::funnel_shl(A, A, i), A.rotate_left(i)); + + assert_eq!(<$T>::funnel_shr(0, A, i), A >> i); + assert_eq!(<$T>::funnel_shr(A, A, i), A.rotate_right(i)); + } + } + #[test] fn test_isolate_highest_one() { const BITS: $T = <$T>::MAX; diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs index ab417b6c72f..75018424c4e 100644 --- a/library/std/src/lib.rs +++ b/library/std/src/lib.rs @@ -296,6 +296,7 @@ #![feature(f128)] #![feature(ffi_const)] #![feature(formatting_options)] +#![feature(funnel_shifts)] #![feature(hash_map_internals)] #![feature(hash_map_macro)] #![feature(if_let_guard)] diff --git a/src/tools/miri/tests/fail/intrinsics/funnel_shl.rs b/src/tools/miri/tests/fail/intrinsics/funnel_shl.rs new file mode 100644 index 00000000000..40b61f65ebe --- /dev/null +++ b/src/tools/miri/tests/fail/intrinsics/funnel_shl.rs @@ -0,0 +1,7 @@ +#![feature(core_intrinsics, funnel_shifts)] + +fn main() { + unsafe { + std::intrinsics::unchecked_funnel_shl(1_u32, 2, 32); //~ ERROR: Undefined Behavior + } +} diff --git a/src/tools/miri/tests/fail/intrinsics/funnel_shl.stderr b/src/tools/miri/tests/fail/intrinsics/funnel_shl.stderr new file mode 100644 index 00000000000..fc828021b13 --- /dev/null +++ b/src/tools/miri/tests/fail/intrinsics/funnel_shl.stderr @@ -0,0 +1,15 @@ +error: Undefined Behavior: `assume` called with `false` + --> tests/fail/intrinsics/funnel_shl.rs:LL:CC + | +LL | std::intrinsics::unchecked_funnel_shl(1_u32, 2, 32); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Undefined Behavior occurred here + | + = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior + = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information + = note: BACKTRACE: + = note: inside `main` at tests/fail/intrinsics/funnel_shl.rs:LL:CC + +note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace + +error: aborting due to 1 previous error + diff --git a/src/tools/miri/tests/fail/intrinsics/funnel_shr.rs b/src/tools/miri/tests/fail/intrinsics/funnel_shr.rs new file mode 100644 index 00000000000..95822656397 --- /dev/null +++ b/src/tools/miri/tests/fail/intrinsics/funnel_shr.rs @@ -0,0 +1,7 @@ +#![feature(core_intrinsics, funnel_shifts)] + +fn main() { + unsafe { + std::intrinsics::unchecked_funnel_shr(1_u32, 2, 32); //~ ERROR: Undefined Behavior + } +} diff --git a/src/tools/miri/tests/fail/intrinsics/funnel_shr.stderr b/src/tools/miri/tests/fail/intrinsics/funnel_shr.stderr new file mode 100644 index 00000000000..7361df1b4c7 --- /dev/null +++ b/src/tools/miri/tests/fail/intrinsics/funnel_shr.stderr @@ -0,0 +1,15 @@ +error: Undefined Behavior: `assume` called with `false` + --> tests/fail/intrinsics/funnel_shr.rs:LL:CC + | +LL | std::intrinsics::unchecked_funnel_shr(1_u32, 2, 32); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Undefined Behavior occurred here + | + = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior + = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information + = note: BACKTRACE: + = note: inside `main` at tests/fail/intrinsics/funnel_shr.rs:LL:CC + +note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace + +error: aborting due to 1 previous error + diff --git a/src/tools/miri/tests/pass/intrinsics/integer.rs b/src/tools/miri/tests/pass/intrinsics/integer.rs index 13e7bd8e1b9..8727b6d3c87 100644 --- a/src/tools/miri/tests/pass/intrinsics/integer.rs +++ b/src/tools/miri/tests/pass/intrinsics/integer.rs @@ -1,7 +1,7 @@ // SPDX-License-Identifier: MIT OR Apache-2.0 // SPDX-FileCopyrightText: The Rust Project Developers (see https://thanks.rust-lang.org) -#![feature(core_intrinsics)] +#![feature(core_intrinsics, funnel_shifts)] use std::intrinsics::*; pub fn main() { @@ -143,5 +143,11 @@ pub fn main() { assert_eq!(unchecked_mul(6u8, 7), 42); assert_eq!(unchecked_mul(13, -5), -65); + + assert_eq!(unchecked_funnel_shl(1_u32, 2, 5), 32); + assert_eq!(unchecked_funnel_shl(1_u32, 2, 31), 0x80000001); + + assert_eq!(unchecked_funnel_shr(1_u32, 2, 5), 0x08000000); + assert_eq!(unchecked_funnel_shr(1_u32, 2, 31), 2); } } -- cgit 1.4.1-3-g733a5 From c914c471b9d83f9e6c74b0e6c2c8044efd3a57dd Mon Sep 17 00:00:00 2001 From: Niklas Fiekas Date: Tue, 29 Apr 2025 14:30:53 +0200 Subject: Add `read_buf` equivalents for positioned reads Adds the following items under the `read_buf_at` feature: - `std::os::unix::fs::FileExt::read_buf_at` - `std::os::unix::fs::FileExt::read_buf_exact_at` - `std::os::windows::fs::FileExt::seek_read_buf` --- library/std/src/fs/tests.rs | 112 ++++++++++++++++++++++++++++++ library/std/src/lib.rs | 1 + library/std/src/os/unix/fs.rs | 89 ++++++++++++++++++++++++ library/std/src/os/windows/fs.rs | 43 ++++++++++++ library/std/src/sys/fd/unix.rs | 65 +++++++++++------ library/std/src/sys/fs/unix.rs | 4 ++ library/std/src/sys/fs/windows.rs | 4 ++ library/std/src/sys/pal/windows/handle.rs | 13 ++++ 8 files changed, 308 insertions(+), 23 deletions(-) (limited to 'library/std/src') diff --git a/library/std/src/fs/tests.rs b/library/std/src/fs/tests.rs index c81e3af2f0d..1f5f848b9d4 100644 --- a/library/std/src/fs/tests.rs +++ b/library/std/src/fs/tests.rs @@ -490,6 +490,85 @@ fn file_test_io_read_write_at() { check!(fs::remove_file(&filename)); } +#[test] +#[cfg(unix)] +fn test_read_buf_at() { + use crate::os::unix::fs::FileExt; + + let tmpdir = tmpdir(); + let filename = tmpdir.join("file_rt_io_file_test_read_buf_at.txt"); + { + let oo = OpenOptions::new().create_new(true).write(true).read(true).clone(); + let mut file = check!(oo.open(&filename)); + check!(file.write_all(b"0123456789")); + } + { + let mut file = check!(File::open(&filename)); + let mut buf: [MaybeUninit; 5] = [MaybeUninit::uninit(); 5]; + let mut buf = BorrowedBuf::from(buf.as_mut_slice()); + + // Fill entire buffer with potentially short reads + while buf.unfilled().capacity() > 0 { + let len = buf.len(); + check!(file.read_buf_at(buf.unfilled(), 2 + len as u64)); + assert!(!buf.filled().is_empty()); + assert!(b"23456".starts_with(buf.filled())); + assert_eq!(check!(file.stream_position()), 0); + } + assert_eq!(buf.filled(), b"23456"); + + // Already full + check!(file.read_buf_at(buf.unfilled(), 3)); + check!(file.read_buf_at(buf.unfilled(), 10)); + assert_eq!(buf.filled(), b"23456"); + assert_eq!(check!(file.stream_position()), 0); + + // Read past eof is noop + check!(file.read_buf_at(buf.clear().unfilled(), 10)); + assert_eq!(buf.filled(), b""); + check!(file.read_buf_at(buf.clear().unfilled(), 11)); + assert_eq!(buf.filled(), b""); + assert_eq!(check!(file.stream_position()), 0); + } + check!(fs::remove_file(&filename)); +} + +#[test] +#[cfg(unix)] +fn test_read_buf_exact_at() { + use crate::os::unix::fs::FileExt; + + let tmpdir = tmpdir(); + let filename = tmpdir.join("file_rt_io_file_test_read_buf_exact_at.txt"); + { + let oo = OpenOptions::new().create_new(true).write(true).read(true).clone(); + let mut file = check!(oo.open(&filename)); + check!(file.write_all(b"0123456789")); + } + { + let mut file = check!(File::open(&filename)); + let mut buf: [MaybeUninit; 5] = [MaybeUninit::uninit(); 5]; + let mut buf = BorrowedBuf::from(buf.as_mut_slice()); + + // Exact read + check!(file.read_buf_exact_at(buf.unfilled(), 2)); + assert_eq!(buf.filled(), b"23456"); + assert_eq!(check!(file.stream_position()), 0); + + // Already full + check!(file.read_buf_exact_at(buf.unfilled(), 3)); + check!(file.read_buf_exact_at(buf.unfilled(), 10)); + assert_eq!(buf.filled(), b"23456"); + assert_eq!(check!(file.stream_position()), 0); + + // Non-empty exact read past eof fails + let err = file.read_buf_exact_at(buf.clear().unfilled(), 6).unwrap_err(); + assert_eq!(err.kind(), ErrorKind::UnexpectedEof); + assert_eq!(check!(file.stream_position()), 0); + } + check!(fs::remove_file(&filename)); +} + #[test] #[cfg(unix)] fn set_get_unix_permissions() { @@ -566,6 +645,39 @@ fn file_test_io_seek_read_write() { check!(fs::remove_file(&filename)); } +#[test] +#[cfg(windows)] +fn test_seek_read_buf() { + use crate::os::windows::fs::FileExt; + + let tmpdir = tmpdir(); + let filename = tmpdir.join("file_rt_io_file_test_seek_read_buf.txt"); + { + let oo = OpenOptions::new().create_new(true).write(true).read(true).clone(); + let mut file = check!(oo.open(&filename)); + check!(file.write_all(b"0123456789")); + } + { + let mut file = check!(File::open(&filename)); + let mut buf: [MaybeUninit; 1] = [MaybeUninit::uninit()]; + let mut buf = BorrowedBuf::from(buf.as_mut_slice()); + + // Seek read + check!(file.seek_read_buf(buf.unfilled(), 8)); + assert_eq!(buf.filled(), b"8"); + assert_eq!(check!(file.stream_position()), 9); + + // Empty seek read + check!(file.seek_read_buf(buf.unfilled(), 0)); + assert_eq!(buf.filled(), b"8"); + + // Seek read past eof + check!(file.seek_read_buf(buf.clear().unfilled(), 10)); + assert_eq!(buf.filled(), b""); + } + check!(fs::remove_file(&filename)); +} + #[test] fn file_test_read_buf() { let tmpdir = tmpdir(); diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs index f111fcb4a47..c27167767a2 100644 --- a/library/std/src/lib.rs +++ b/library/std/src/lib.rs @@ -330,6 +330,7 @@ #![feature(bstr)] #![feature(bstr_internals)] #![feature(cast_maybe_uninit)] +#![feature(cfg_select)] #![feature(char_internals)] #![feature(clone_to_uninit)] #![feature(const_cmp)] diff --git a/library/std/src/os/unix/fs.rs b/library/std/src/os/unix/fs.rs index b776df3dde1..1d1a138b302 100644 --- a/library/std/src/os/unix/fs.rs +++ b/library/std/src/os/unix/fs.rs @@ -11,6 +11,7 @@ use super::platform::fs::MetadataExt as _; // Used for `File::read` on intra-doc links use crate::ffi::OsStr; use crate::fs::{self, OpenOptions, Permissions}; +use crate::io::BorrowedCursor; use crate::os::unix::io::{AsFd, AsRawFd}; use crate::path::Path; use crate::sealed::Sealed; @@ -130,6 +131,91 @@ pub trait FileExt { if !buf.is_empty() { Err(io::Error::READ_EXACT_EOF) } else { Ok(()) } } + /// Reads some bytes starting from a given offset into the buffer. + /// + /// This equivalent to the [`read_at`](FileExt::read_at) method, except that it is passed a + /// [`BorrowedCursor`] rather than `&mut [u8]` to allow use with uninitialized buffers. The new + /// data will be appended to any existing contents of `buf`. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(core_io_borrowed_buf)] + /// #![feature(read_buf_at)] + /// + /// use std::io; + /// use std::io::BorrowedBuf; + /// use std::fs::File; + /// use std::mem::MaybeUninit; + /// use std::os::unix::prelude::*; + /// + /// fn main() -> io::Result<()> { + /// let mut file = File::open("pi.txt")?; + /// + /// // Read some bytes starting from offset 2 + /// let mut buf: [MaybeUninit; 10] = [MaybeUninit::uninit(); 10]; + /// let mut buf = BorrowedBuf::from(buf.as_mut_slice()); + /// file.read_buf_at(buf.unfilled(), 2)?; + /// + /// assert!(buf.filled().starts_with(b"1")); + /// + /// Ok(()) + /// } + /// ``` + #[unstable(feature = "read_buf_at", issue = "140771")] + fn read_buf_at(&self, buf: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + io::default_read_buf(|b| self.read_at(b, offset), buf) + } + + /// Reads the exact number of bytes required to fill the buffer from a given offset. + /// + /// This is equivalent to the [`read_exact_at`](FileExt::read_exact_at) method, except that it + /// is passed a [`BorrowedCursor`] rather than `&mut [u8]` to allow use with uninitialized + /// buffers. The new data will be appended to any existing contents of `buf`. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(core_io_borrowed_buf)] + /// #![feature(read_buf_at)] + /// + /// use std::io; + /// use std::io::BorrowedBuf; + /// use std::fs::File; + /// use std::mem::MaybeUninit; + /// use std::os::unix::prelude::*; + /// + /// fn main() -> io::Result<()> { + /// let mut file = File::open("pi.txt")?; + /// + /// // Read exactly 10 bytes starting from offset 2 + /// let mut buf: [MaybeUninit; 10] = [MaybeUninit::uninit(); 10]; + /// let mut buf = BorrowedBuf::from(buf.as_mut_slice()); + /// file.read_buf_exact_at(buf.unfilled(), 2)?; + /// + /// assert_eq!(buf.filled(), b"1415926535"); + /// + /// Ok(()) + /// } + /// ``` + #[unstable(feature = "read_buf_at", issue = "140771")] + fn read_buf_exact_at(&self, mut buf: BorrowedCursor<'_>, mut offset: u64) -> io::Result<()> { + while buf.capacity() > 0 { + let prev_written = buf.written(); + match self.read_buf_at(buf.reborrow(), offset) { + Ok(()) => {} + Err(e) if e.is_interrupted() => {} + Err(e) => return Err(e), + } + let n = buf.written() - prev_written; + offset += n as u64; + if n == 0 { + return Err(io::Error::READ_EXACT_EOF); + } + } + Ok(()) + } + /// Writes a number of bytes starting from a given offset. /// /// Returns the number of bytes written. @@ -264,6 +350,9 @@ impl FileExt for fs::File { fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result { self.as_inner().read_at(buf, offset) } + fn read_buf_at(&self, buf: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + self.as_inner().read_buf_at(buf, offset) + } fn read_vectored_at(&self, bufs: &mut [io::IoSliceMut<'_>], offset: u64) -> io::Result { self.as_inner().read_vectored_at(bufs, offset) } diff --git a/library/std/src/os/windows/fs.rs b/library/std/src/os/windows/fs.rs index ddb8dbd8fee..b445f368aeb 100644 --- a/library/std/src/os/windows/fs.rs +++ b/library/std/src/os/windows/fs.rs @@ -5,6 +5,7 @@ #![stable(feature = "rust1", since = "1.0.0")] use crate::fs::{self, Metadata, OpenOptions}; +use crate::io::BorrowedCursor; use crate::path::Path; use crate::sealed::Sealed; use crate::sys_common::{AsInner, AsInnerMut, IntoInner}; @@ -49,6 +50,44 @@ pub trait FileExt { #[stable(feature = "file_offset", since = "1.15.0")] fn seek_read(&self, buf: &mut [u8], offset: u64) -> io::Result; + /// Seeks to a given position and reads some bytes into the buffer. + /// + /// This is equivalent to the [`seek_read`](FileExt::seek_read) method, except that it is passed + /// a [`BorrowedCursor`] rather than `&mut [u8]` to allow use with uninitialized buffers. The + /// new data will be appended to any existing contents of `buf`. + /// + /// Reading beyond the end of the file will always succeed without reading any bytes. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(core_io_borrowed_buf)] + /// #![feature(read_buf_at)] + /// + /// use std::io; + /// use std::io::BorrowedBuf; + /// use std::fs::File; + /// use std::mem::MaybeUninit; + /// use std::os::windows::prelude::*; + /// + /// fn main() -> io::Result<()> { + /// let mut file = File::open("pi.txt")?; + /// + /// // Read some bytes starting from offset 2 + /// let mut buf: [MaybeUninit; 10] = [MaybeUninit::uninit(); 10]; + /// let mut buf = BorrowedBuf::from(buf.as_mut_slice()); + /// file.seek_read_buf(buf.unfilled(), 2)?; + /// + /// assert!(buf.filled().starts_with(b"1")); + /// + /// Ok(()) + /// } + /// ``` + #[unstable(feature = "read_buf_at", issue = "140771")] + fn seek_read_buf(&self, buf: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + io::default_read_buf(|b| self.seek_read(b, offset), buf) + } + /// Seeks to a given position and writes a number of bytes. /// /// Returns the number of bytes written. @@ -89,6 +128,10 @@ impl FileExt for fs::File { self.as_inner().read_at(buf, offset) } + fn seek_read_buf(&self, buf: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + self.as_inner().read_buf_at(buf, offset) + } + fn seek_write(&self, buf: &[u8], offset: u64) -> io::Result { self.as_inner().write_at(buf, offset) } diff --git a/library/std/src/sys/fd/unix.rs b/library/std/src/sys/fd/unix.rs index cdca73cdca1..1701bac3113 100644 --- a/library/std/src/sys/fd/unix.rs +++ b/library/std/src/sys/fd/unix.rs @@ -18,6 +18,21 @@ use libc::off_t as off64_t; ))] use libc::off64_t; +cfg_select! { + any( + all(target_os = "linux", not(target_env = "musl")), + target_os = "android", + target_os = "hurd", + ) => { + // Prefer explicit pread64 for 64-bit offset independently of libc + // #[cfg(gnu_file_offset_bits64)]. + use libc::pread64; + } + _ => { + use libc::pread as pread64; + } +} + use crate::cmp; use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, Read}; use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd}; @@ -146,42 +161,47 @@ impl FileDesc { (&mut me).read_to_end(buf) } - #[cfg_attr(target_os = "vxworks", allow(unused_unsafe))] pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result { - #[cfg(not(any( - all(target_os = "linux", not(target_env = "musl")), - target_os = "android", - target_os = "hurd" - )))] - use libc::pread as pread64; - #[cfg(any( - all(target_os = "linux", not(target_env = "musl")), - target_os = "android", - target_os = "hurd" - ))] - use libc::pread64; - - unsafe { - cvt(pread64( + cvt(unsafe { + pread64( self.as_raw_fd(), buf.as_mut_ptr() as *mut libc::c_void, cmp::min(buf.len(), READ_LIMIT), - offset as off64_t, - )) - .map(|n| n as usize) - } + offset as off64_t, // EINVAL if offset + count overflows + ) + }) + .map(|n| n as usize) } pub fn read_buf(&self, mut cursor: BorrowedCursor<'_>) -> io::Result<()> { + // SAFETY: `cursor.as_mut()` starts with `cursor.capacity()` writable bytes let ret = cvt(unsafe { libc::read( self.as_raw_fd(), - cursor.as_mut().as_mut_ptr() as *mut libc::c_void, + cursor.as_mut().as_mut_ptr().cast::(), + cmp::min(cursor.capacity(), READ_LIMIT), + ) + })?; + + // SAFETY: `ret` bytes were written to the initialized portion of the buffer + unsafe { + cursor.advance_unchecked(ret as usize); + } + Ok(()) + } + + pub fn read_buf_at(&self, mut cursor: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + // SAFETY: `cursor.as_mut()` starts with `cursor.capacity()` writable bytes + let ret = cvt(unsafe { + pread64( + self.as_raw_fd(), + cursor.as_mut().as_mut_ptr().cast::(), cmp::min(cursor.capacity(), READ_LIMIT), + offset as off64_t, // EINVAL if offset + count overflows ) })?; - // Safety: `ret` bytes were written to the initialized portion of the buffer + // SAFETY: `ret` bytes were written to the initialized portion of the buffer unsafe { cursor.advance_unchecked(ret as usize); } @@ -369,7 +389,6 @@ impl FileDesc { ))) } - #[cfg_attr(target_os = "vxworks", allow(unused_unsafe))] pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result { #[cfg(not(any( all(target_os = "linux", not(target_env = "musl")), diff --git a/library/std/src/sys/fs/unix.rs b/library/std/src/sys/fs/unix.rs index b310db2dac4..30be6d445ff 100644 --- a/library/std/src/sys/fs/unix.rs +++ b/library/std/src/sys/fs/unix.rs @@ -1422,6 +1422,10 @@ impl File { self.0.read_buf(cursor) } + pub fn read_buf_at(&self, cursor: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + self.0.read_buf_at(cursor, offset) + } + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result { self.0.read_vectored_at(bufs, offset) } diff --git a/library/std/src/sys/fs/windows.rs b/library/std/src/sys/fs/windows.rs index bb3e4bc30ca..c39571af693 100644 --- a/library/std/src/sys/fs/windows.rs +++ b/library/std/src/sys/fs/windows.rs @@ -587,6 +587,10 @@ impl File { self.handle.read_buf(cursor) } + pub fn read_buf_at(&self, cursor: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + self.handle.read_buf_at(cursor, offset) + } + pub fn write(&self, buf: &[u8]) -> io::Result { self.handle.write(buf) } diff --git a/library/std/src/sys/pal/windows/handle.rs b/library/std/src/sys/pal/windows/handle.rs index 82a880faf5f..76c8aa939d3 100644 --- a/library/std/src/sys/pal/windows/handle.rs +++ b/library/std/src/sys/pal/windows/handle.rs @@ -136,6 +136,19 @@ impl Handle { } } + pub fn read_buf_at(&self, mut cursor: BorrowedCursor<'_>, offset: u64) -> io::Result<()> { + // SAFETY: `cursor.as_mut()` starts with `cursor.capacity()` writable bytes + let read = unsafe { + self.synchronous_read(cursor.as_mut().as_mut_ptr(), cursor.capacity(), Some(offset)) + }?; + + // SAFETY: `read` bytes were written to the initialized portion of the buffer + unsafe { + cursor.advance_unchecked(read); + } + Ok(()) + } + pub fn read_to_end(&self, buf: &mut Vec) -> io::Result { let mut me = self; -- cgit 1.4.1-3-g733a5 From 1e37c1fe2e29d88d4843e7c0ce46e50edd9f7251 Mon Sep 17 00:00:00 2001 From: bendn Date: Thu, 4 Sep 2025 14:06:44 +0700 Subject: fix --- library/std/src/path.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'library/std/src') diff --git a/library/std/src/path.rs b/library/std/src/path.rs index 531a1aa4215..19663e4a9df 100644 --- a/library/std/src/path.rs +++ b/library/std/src/path.rs @@ -2107,7 +2107,7 @@ impl PartialEq for PathBuf { impl cmp::PartialEq for PathBuf { #[inline] fn eq(&self, other: &str) -> bool { - &*self == other + Path::eq(self, other) } } -- cgit 1.4.1-3-g733a5