From 377a0c88a9bbfa8a389163b2ac3de38e64d762dc Mon Sep 17 00:00:00 2001 From: Karl Meakin Date: Fri, 25 Jul 2025 22:17:24 +0100 Subject: [PATCH] Consolidate panicking functions in `slice/index.rs` Consolidate all the panicking functions in `slice/index.rs` to use a single `slice_index_fail` function, similar to how it is done in `str/traits.rs`. --- library/core/src/slice/index.rs | 200 +++++++++--------- library/coretests/tests/slice.rs | 10 +- .../miri/tests/panic/oob_subslice.stderr | 2 +- .../binary-search-index-no-bound-check.rs | 3 +- tests/codegen-llvm/integer-overflow.rs | 4 +- ...issue-113757-bounds-check-after-cmp-max.rs | 2 +- tests/codegen-llvm/issues/issue-27130.rs | 4 +- .../issues/issue-69101-bounds-check.rs | 6 +- ...issue-73396-bounds-check-after-position.rs | 18 +- .../slice-last-elements-optimization.rs | 11 +- tests/codegen-llvm/slice-reverse.rs | 8 +- ...dex_range.PreCodegen.after.panic-abort.mir | 69 +++++- ...ex_range.PreCodegen.after.panic-unwind.mir | 69 +++++- 13 files changed, 269 insertions(+), 137 deletions(-) diff --git a/library/core/src/slice/index.rs b/library/core/src/slice/index.rs index ae360df80f60b..98091e9fe83fb 100644 --- a/library/core/src/slice/index.rs +++ b/library/core/src/slice/index.rs @@ -34,53 +34,44 @@ where #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)] #[cfg_attr(feature = "panic_immediate_abort", inline)] #[track_caller] -const fn slice_start_index_len_fail(index: usize, len: usize) -> ! { - const_panic!( - "slice start index is out of range for slice", - "range start index {index} out of range for slice of length {len}", - index: usize, - len: usize, - ) -} +const fn slice_index_fail(start: usize, end: usize, len: usize) -> ! { + if start > len { + const_panic!( + "slice start index is out of range for slice", + "range start index {start} out of range for slice of length {len}", + start: usize, + len: usize, + ) + } -#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)] -#[cfg_attr(feature = "panic_immediate_abort", inline)] -#[track_caller] -const fn slice_end_index_len_fail(index: usize, len: usize) -> ! { - const_panic!( - "slice end index is out of range for slice", - "range end index {index} out of range for slice of length {len}", - index: usize, - len: usize, - ) -} + if end > len { + const_panic!( + "slice end index is out of range for slice", + "range end index {end} out of range for slice of length {len}", + end: usize, + len: usize, + ) + } -#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)] -#[cfg_attr(feature = "panic_immediate_abort", inline)] -#[track_caller] -const fn slice_index_order_fail(index: usize, end: usize) -> ! { + if start > end { + const_panic!( + "slice index start is larger than end", + "slice index starts at {start} but ends at {end}", + start: usize, + end: usize, + ) + } + + // Only reachable if the range was a `RangeInclusive` or a + // `RangeToInclusive`, with `end == len`. const_panic!( - "slice index start is larger than end", - "slice index starts at {index} but ends at {end}", - index: usize, + "slice end index is out of range for slice", + "range end index {end} out of range for slice of length {len}", end: usize, + len: usize, ) } -#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)] -#[cfg_attr(feature = "panic_immediate_abort", inline)] -#[track_caller] -const fn slice_start_index_overflow_fail() -> ! { - panic!("attempted to index slice from after maximum usize"); -} - -#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)] -#[cfg_attr(feature = "panic_immediate_abort", inline)] -#[track_caller] -const fn slice_end_index_overflow_fail() -> ! { - panic!("attempted to index slice up to maximum usize"); -} - // The UbChecks are great for catching bugs in the unsafe methods, but including // them in safe indexing is unnecessary and hurts inlining and debug runtime perf. // Both the safe and unsafe public methods share these helpers, @@ -341,7 +332,7 @@ unsafe impl const SliceIndex<[T]> for ops::IndexRange { // SAFETY: `self` is checked to be valid and in bounds above. unsafe { &*get_offset_len_noubcheck(slice, self.start(), self.len()) } } else { - slice_end_index_len_fail(self.end(), slice.len()) + slice_index_fail(self.start(), self.end(), slice.len()) } } @@ -351,7 +342,7 @@ unsafe impl const SliceIndex<[T]> for ops::IndexRange { // SAFETY: `self` is checked to be valid and in bounds above. unsafe { &mut *get_offset_len_mut_noubcheck(slice, self.start(), self.len()) } } else { - slice_end_index_len_fail(self.end(), slice.len()) + slice_index_fail(self.start(), self.end(), slice.len()) } } } @@ -436,26 +427,27 @@ unsafe impl const SliceIndex<[T]> for ops::Range { #[inline(always)] fn index(self, slice: &[T]) -> &[T] { // Using checked_sub is a safe way to get `SubUnchecked` in MIR - let Some(new_len) = usize::checked_sub(self.end, self.start) else { - slice_index_order_fail(self.start, self.end) - }; - if self.end > slice.len() { - slice_end_index_len_fail(self.end, slice.len()); + if let Some(new_len) = usize::checked_sub(self.end, self.start) + && self.end <= slice.len() + { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { &*get_offset_len_noubcheck(slice, self.start, new_len) } + } else { + slice_index_fail(self.start, self.end, slice.len()) } - // SAFETY: `self` is checked to be valid and in bounds above. - unsafe { &*get_offset_len_noubcheck(slice, self.start, new_len) } } #[inline] fn index_mut(self, slice: &mut [T]) -> &mut [T] { - let Some(new_len) = usize::checked_sub(self.end, self.start) else { - slice_index_order_fail(self.start, self.end) - }; - if self.end > slice.len() { - slice_end_index_len_fail(self.end, slice.len()); + // Using checked_sub is a safe way to get `SubUnchecked` in MIR + if let Some(new_len) = usize::checked_sub(self.end, self.start) + && self.end <= slice.len() + { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { &mut *get_offset_len_mut_noubcheck(slice, self.start, new_len) } + } else { + slice_index_fail(self.start, self.end, slice.len()) } - // SAFETY: `self` is checked to be valid and in bounds above. - unsafe { &mut *get_offset_len_mut_noubcheck(slice, self.start, new_len) } } } @@ -567,7 +559,7 @@ unsafe impl const SliceIndex<[T]> for ops::RangeFrom { #[inline] fn index(self, slice: &[T]) -> &[T] { if self.start > slice.len() { - slice_start_index_len_fail(self.start, slice.len()); + slice_index_fail(self.start, slice.len(), slice.len()) } // SAFETY: `self` is checked to be valid and in bounds above. unsafe { &*self.get_unchecked(slice) } @@ -576,7 +568,7 @@ unsafe impl const SliceIndex<[T]> for ops::RangeFrom { #[inline] fn index_mut(self, slice: &mut [T]) -> &mut [T] { if self.start > slice.len() { - slice_start_index_len_fail(self.start, slice.len()); + slice_index_fail(self.start, slice.len(), slice.len()) } // SAFETY: `self` is checked to be valid and in bounds above. unsafe { &mut *self.get_unchecked_mut(slice) } @@ -690,18 +682,32 @@ unsafe impl const SliceIndex<[T]> for ops::RangeInclusive { #[inline] fn index(self, slice: &[T]) -> &[T] { - if *self.end() == usize::MAX { - slice_end_index_overflow_fail(); + let Self { mut start, mut end, exhausted } = self; + let len = slice.len(); + if end < len { + end = end + 1; + start = if exhausted { end } else { start }; + if let Some(new_len) = usize::checked_sub(end, start) { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { return &*get_offset_len_noubcheck(slice, start, new_len) } + } } - self.into_slice_range().index(slice) + slice_index_fail(start, end, slice.len()) } #[inline] fn index_mut(self, slice: &mut [T]) -> &mut [T] { - if *self.end() == usize::MAX { - slice_end_index_overflow_fail(); + let Self { mut start, mut end, exhausted } = self; + let len = slice.len(); + if end < len { + end = end + 1; + start = if exhausted { end } else { start }; + if let Some(new_len) = usize::checked_sub(end, start) { + // SAFETY: `self` is checked to be valid and in bounds above. + unsafe { return &mut *get_offset_len_mut_noubcheck(slice, start, new_len) } + } } - self.into_slice_range().index_mut(slice) + slice_index_fail(start, end, slice.len()) } } @@ -852,28 +858,26 @@ where { let len = bounds.end; - let start = match range.start_bound() { - ops::Bound::Included(&start) => start, - ops::Bound::Excluded(start) => { - start.checked_add(1).unwrap_or_else(|| slice_start_index_overflow_fail()) - } - ops::Bound::Unbounded => 0, - }; - let end = match range.end_bound() { - ops::Bound::Included(end) => { - end.checked_add(1).unwrap_or_else(|| slice_end_index_overflow_fail()) - } + ops::Bound::Included(&end) if end >= len => slice_index_fail(0, end, len), + // Cannot overflow because `end < len` implies `end < usize::MAX`. + ops::Bound::Included(&end) => end + 1, + + ops::Bound::Excluded(&end) if end > len => slice_index_fail(0, end, len), ops::Bound::Excluded(&end) => end, ops::Bound::Unbounded => len, }; - if start > end { - slice_index_order_fail(start, end); - } - if end > len { - slice_end_index_len_fail(end, len); - } + let start = match range.start_bound() { + ops::Bound::Excluded(&start) if start >= end => slice_index_fail(start, end, len), + // Cannot overflow because `start < end` implies `start < usize::MAX`. + ops::Bound::Excluded(&start) => start + 1, + + ops::Bound::Included(&start) if start > end => slice_index_fail(start, end, len), + ops::Bound::Included(&start) => start, + + ops::Bound::Unbounded => 0, + }; ops::Range { start, end } } @@ -982,25 +986,27 @@ pub(crate) fn into_slice_range( len: usize, (start, end): (ops::Bound, ops::Bound), ) -> ops::Range { - use ops::Bound; - let start = match start { - Bound::Included(start) => start, - Bound::Excluded(start) => { - start.checked_add(1).unwrap_or_else(|| slice_start_index_overflow_fail()) - } - Bound::Unbounded => 0, - }; - let end = match end { - Bound::Included(end) => { - end.checked_add(1).unwrap_or_else(|| slice_end_index_overflow_fail()) - } - Bound::Excluded(end) => end, - Bound::Unbounded => len, + ops::Bound::Included(end) if end >= len => slice_index_fail(0, end, len), + // Cannot overflow because `end < len` implies `end < usize::MAX`. + ops::Bound::Included(end) => end + 1, + + ops::Bound::Excluded(end) if end > len => slice_index_fail(0, end, len), + ops::Bound::Excluded(end) => end, + + ops::Bound::Unbounded => len, }; - // Don't bother with checking `start < end` and `end <= len` - // since these checks are handled by `Range` impls + let start = match start { + ops::Bound::Excluded(start) if start >= end => slice_index_fail(start, end, len), + // Cannot overflow because `start < end` implies `start < usize::MAX`. + ops::Bound::Excluded(start) => start + 1, + + ops::Bound::Included(start) if start > end => slice_index_fail(start, end, len), + ops::Bound::Included(start) => start, + + ops::Bound::Unbounded => 0, + }; start..end } diff --git a/library/coretests/tests/slice.rs b/library/coretests/tests/slice.rs index 992f24cb18f20..110c4e5f3b406 100644 --- a/library/coretests/tests/slice.rs +++ b/library/coretests/tests/slice.rs @@ -1492,28 +1492,28 @@ mod slice_index { // note: using 0 specifically ensures that the result of overflowing is 0..0, // so that `get` doesn't simply return None for the wrong reason. bad: data[0 ..= usize::MAX]; - message: "maximum usize"; + message: "out of range"; } in mod rangetoinclusive_overflow { data: [0, 1]; bad: data[..= usize::MAX]; - message: "maximum usize"; + message: "out of range"; } in mod boundpair_overflow_end { data: [0; 1]; bad: data[(Bound::Unbounded, Bound::Included(usize::MAX))]; - message: "maximum usize"; + message: "out of range"; } in mod boundpair_overflow_start { data: [0; 1]; bad: data[(Bound::Excluded(usize::MAX), Bound::Unbounded)]; - message: "maximum usize"; + message: "out of range"; } } // panic_cases! } @@ -2008,7 +2008,7 @@ fn test_copy_within_panics_src_inverted() { bytes.copy_within(2..1, 0); } #[test] -#[should_panic(expected = "attempted to index slice up to maximum usize")] +#[should_panic(expected = "out of range")] fn test_copy_within_panics_src_out_of_bounds() { let mut bytes = *b"Hello, World!"; // an inclusive range ending at usize::MAX would make src_end overflow diff --git a/src/tools/miri/tests/panic/oob_subslice.stderr b/src/tools/miri/tests/panic/oob_subslice.stderr index f8270f4ad4de1..e1e5bd33d311b 100644 --- a/src/tools/miri/tests/panic/oob_subslice.stderr +++ b/src/tools/miri/tests/panic/oob_subslice.stderr @@ -1,5 +1,5 @@ thread 'main' ($TID) panicked at tests/panic/oob_subslice.rs:LL:CC: -range end index 5 out of range for slice of length 4 +range end index 4 out of range for slice of length 4 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect diff --git a/tests/codegen-llvm/binary-search-index-no-bound-check.rs b/tests/codegen-llvm/binary-search-index-no-bound-check.rs index d59c0beec6419..8322c4179bd14 100644 --- a/tests/codegen-llvm/binary-search-index-no-bound-check.rs +++ b/tests/codegen-llvm/binary-search-index-no-bound-check.rs @@ -8,8 +8,7 @@ #[no_mangle] pub fn binary_search_index_no_bounds_check(s: &[u8]) -> u8 { // CHECK-NOT: panic - // CHECK-NOT: slice_start_index_len_fail - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: panic_bounds_check if let Ok(idx) = s.binary_search(&b'\\') { s[idx] } else { 42 } } diff --git a/tests/codegen-llvm/integer-overflow.rs b/tests/codegen-llvm/integer-overflow.rs index 80362247a86f1..df7845be06d17 100644 --- a/tests/codegen-llvm/integer-overflow.rs +++ b/tests/codegen-llvm/integer-overflow.rs @@ -10,7 +10,7 @@ pub struct S1<'a> { // CHECK-LABEL: @slice_no_index_order #[no_mangle] pub fn slice_no_index_order<'a>(s: &'a mut S1, n: usize) -> &'a [u8] { - // CHECK-NOT: slice_index_order_fail + // CHECK-COUNT-1: slice_index_fail let d = &s.data[s.position..s.position + n]; s.position += n; return d; @@ -19,6 +19,6 @@ pub fn slice_no_index_order<'a>(s: &'a mut S1, n: usize) -> &'a [u8] { // CHECK-LABEL: @test_check #[no_mangle] pub fn test_check<'a>(s: &'a mut S1, x: usize, y: usize) -> &'a [u8] { - // CHECK: slice_index_order_fail + // CHECK-COUNT-1: slice_index_fail &s.data[x..y] } diff --git a/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs b/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs index d495adf99804c..0db8a5220ec5b 100644 --- a/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs +++ b/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs @@ -5,7 +5,7 @@ use std::cmp::max; // CHECK-LABEL: @foo -// CHECK-NOT: slice_start_index_len_fail +// CHECK-NOT: slice_index_fail // CHECK-NOT: unreachable #[no_mangle] pub fn foo(v: &mut Vec, size: usize) -> Option<&mut [u8]> { diff --git a/tests/codegen-llvm/issues/issue-27130.rs b/tests/codegen-llvm/issues/issue-27130.rs index 594e02af0977f..3e53c5cffd666 100644 --- a/tests/codegen-llvm/issues/issue-27130.rs +++ b/tests/codegen-llvm/issues/issue-27130.rs @@ -6,7 +6,7 @@ #[no_mangle] pub fn trim_in_place(a: &mut &[u8]) { while a.first() == Some(&42) { - // CHECK-NOT: slice_index_order_fail + // CHECK-NOT: slice_index_fail *a = &a[1..]; } } @@ -15,7 +15,7 @@ pub fn trim_in_place(a: &mut &[u8]) { #[no_mangle] pub fn trim_in_place2(a: &mut &[u8]) { while let Some(&42) = a.first() { - // CHECK-NOT: slice_index_order_fail + // CHECK-COUNT-1: slice_index_fail *a = &a[2..]; } } diff --git a/tests/codegen-llvm/issues/issue-69101-bounds-check.rs b/tests/codegen-llvm/issues/issue-69101-bounds-check.rs index 953b79aa263e8..f1857a9ce89d2 100644 --- a/tests/codegen-llvm/issues/issue-69101-bounds-check.rs +++ b/tests/codegen-llvm/issues/issue-69101-bounds-check.rs @@ -10,7 +10,7 @@ // CHECK-LABEL: @already_sliced_no_bounds_check #[no_mangle] pub fn already_sliced_no_bounds_check(a: &[u8], b: &[u8], c: &mut [u8]) { - // CHECK: slice_end_index_len_fail + // CHECK: slice_index_fail // CHECK-NOT: panic_bounds_check let _ = (&a[..2048], &b[..2048], &mut c[..2048]); for i in 0..1024 { @@ -21,7 +21,7 @@ pub fn already_sliced_no_bounds_check(a: &[u8], b: &[u8], c: &mut [u8]) { // CHECK-LABEL: @already_sliced_no_bounds_check_exact #[no_mangle] pub fn already_sliced_no_bounds_check_exact(a: &[u8], b: &[u8], c: &mut [u8]) { - // CHECK: slice_end_index_len_fail + // CHECK: slice_index_fail // CHECK-NOT: panic_bounds_check let _ = (&a[..1024], &b[..1024], &mut c[..1024]); for i in 0..1024 { @@ -33,7 +33,7 @@ pub fn already_sliced_no_bounds_check_exact(a: &[u8], b: &[u8], c: &mut [u8]) { // CHECK-LABEL: @already_sliced_bounds_check #[no_mangle] pub fn already_sliced_bounds_check(a: &[u8], b: &[u8], c: &mut [u8]) { - // CHECK: slice_end_index_len_fail + // CHECK: slice_index_fail // CHECK: panic_bounds_check let _ = (&a[..1023], &b[..2048], &mut c[..2048]); for i in 0..1024 { diff --git a/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs b/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs index 1e2c25babe0a5..8a2200478aa08 100644 --- a/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs +++ b/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs @@ -8,8 +8,7 @@ #[no_mangle] pub fn position_slice_to_no_bounds_check(s: &[u8]) -> &[u8] { // CHECK-NOT: panic - // CHECK-NOT: slice_start_index_len_fail - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: panic_bounds_check // CHECK-NOT: unreachable if let Some(idx) = s.iter().position(|b| *b == b'\\') { &s[..idx] } else { s } @@ -19,8 +18,7 @@ pub fn position_slice_to_no_bounds_check(s: &[u8]) -> &[u8] { #[no_mangle] pub fn position_slice_from_no_bounds_check(s: &[u8]) -> &[u8] { // CHECK-NOT: panic - // CHECK-NOT: slice_start_index_len_fail - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: panic_bounds_check // CHECK-NOT: unreachable if let Some(idx) = s.iter().position(|b| *b == b'\\') { &s[idx..] } else { s } @@ -30,8 +28,7 @@ pub fn position_slice_from_no_bounds_check(s: &[u8]) -> &[u8] { #[no_mangle] pub fn position_index_no_bounds_check(s: &[u8]) -> u8 { // CHECK-NOT: panic - // CHECK-NOT: slice_start_index_len_fail - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: panic_bounds_check // CHECK-NOT: unreachable if let Some(idx) = s.iter().position(|b| *b == b'\\') { s[idx] } else { 42 } @@ -40,8 +37,7 @@ pub fn position_index_no_bounds_check(s: &[u8]) -> u8 { #[no_mangle] pub fn rposition_slice_to_no_bounds_check(s: &[u8]) -> &[u8] { // CHECK-NOT: panic - // CHECK-NOT: slice_start_index_len_fail - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: panic_bounds_check // CHECK-NOT: unreachable if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { &s[..idx] } else { s } @@ -51,8 +47,7 @@ pub fn rposition_slice_to_no_bounds_check(s: &[u8]) -> &[u8] { #[no_mangle] pub fn rposition_slice_from_no_bounds_check(s: &[u8]) -> &[u8] { // CHECK-NOT: panic - // CHECK-NOT: slice_start_index_len_fail - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: panic_bounds_check // CHECK-NOT: unreachable if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { &s[idx..] } else { s } @@ -62,8 +57,7 @@ pub fn rposition_slice_from_no_bounds_check(s: &[u8]) -> &[u8] { #[no_mangle] pub fn rposition_index_no_bounds_check(s: &[u8]) -> u8 { // CHECK-NOT: panic - // CHECK-NOT: slice_start_index_len_fail - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: panic_bounds_check // CHECK-NOT: unreachable if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { s[idx] } else { 42 } diff --git a/tests/codegen-llvm/slice-last-elements-optimization.rs b/tests/codegen-llvm/slice-last-elements-optimization.rs index b90f91d7b17b9..d982cda709d47 100644 --- a/tests/codegen-llvm/slice-last-elements-optimization.rs +++ b/tests/codegen-llvm/slice-last-elements-optimization.rs @@ -1,19 +1,18 @@ //@ compile-flags: -Copt-level=3 -//@ only-x86_64 //@ min-llvm-version: 20 #![crate_type = "lib"] // This test verifies that LLVM 20 properly optimizes the bounds check // when accessing the last few elements of a slice with proper conditions. // Previously, this would generate an unreachable branch to -// slice_start_index_len_fail even when the bounds check was provably safe. +// slice_index_fail even when the bounds check was provably safe. // CHECK-LABEL: @last_four_initial( #[no_mangle] pub fn last_four_initial(s: &[u8]) -> &[u8] { - // Previously this would generate a branch to slice_start_index_len_fail + // Previously this would generate a branch to slice_index_fail // that is unreachable. The LLVM 20 fix should eliminate this branch. - // CHECK-NOT: slice_start_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: unreachable let start = if s.len() <= 4 { 0 } else { s.len() - 4 }; &s[start..] @@ -23,7 +22,7 @@ pub fn last_four_initial(s: &[u8]) -> &[u8] { #[no_mangle] pub fn last_four_optimized(s: &[u8]) -> &[u8] { // This version was already correctly optimized before the fix in LLVM 20. - // CHECK-NOT: slice_start_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK-NOT: unreachable if s.len() <= 4 { &s[0..] } else { &s[s.len() - 4..] } } @@ -32,6 +31,6 @@ pub fn last_four_optimized(s: &[u8]) -> &[u8] { // CHECK-LABEL: @test_bounds_check_happens( #[no_mangle] pub fn test_bounds_check_happens(s: &[u8], i: usize) -> &[u8] { - // CHECK: slice_start_index_len_fail + // CHECK: slice_index_fail &s[i..] } diff --git a/tests/codegen-llvm/slice-reverse.rs b/tests/codegen-llvm/slice-reverse.rs index e58d1c1d9d8ea..c31cff5010b4e 100644 --- a/tests/codegen-llvm/slice-reverse.rs +++ b/tests/codegen-llvm/slice-reverse.rs @@ -8,10 +8,10 @@ #[no_mangle] pub fn slice_reverse_u8(slice: &mut [u8]) { // CHECK-NOT: panic_bounds_check - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK: shufflevector <{{[0-9]+}} x i8> // CHECK-NOT: panic_bounds_check - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail slice.reverse(); } @@ -19,9 +19,9 @@ pub fn slice_reverse_u8(slice: &mut [u8]) { #[no_mangle] pub fn slice_reverse_i32(slice: &mut [i32]) { // CHECK-NOT: panic_bounds_check - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail // CHECK: shufflevector <{{[0-9]+}} x i32> // CHECK-NOT: panic_bounds_check - // CHECK-NOT: slice_end_index_len_fail + // CHECK-NOT: slice_index_fail slice.reverse(); } diff --git a/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-abort.mir index 731f6438a6ec7..2df2c4b85b8fa 100644 --- a/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-abort.mir +++ b/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-abort.mir @@ -4,14 +4,81 @@ fn slice_index_range(_1: &[u32], _2: std::ops::Range) -> &[u32] { debug slice => _1; debug index => _2; let mut _0: &[u32]; + let mut _3: usize; + let mut _4: usize; scope 1 (inlined #[track_caller] core::slice::index::> for [u32]>::index) { + scope 2 (inlined #[track_caller] as SliceIndex<[u32]>>::index) { + let mut _7: usize; + let mut _8: bool; + let mut _9: *const [u32]; + let _12: *const [u32]; + let mut _13: usize; + let mut _14: !; + scope 3 (inlined core::num::::checked_sub) { + let mut _5: bool; + let mut _6: usize; + } + scope 4 (inlined core::slice::index::get_offset_len_noubcheck::) { + let _10: *const u32; + scope 5 { + let _11: *const u32; + scope 6 { + } + } + } + } } bb0: { - _0 = as SliceIndex<[u32]>>::index(move _2, move _1) -> [return: bb1, unwind unreachable]; + _3 = move (_2.0: usize); + _4 = move (_2.1: usize); + StorageLive(_5); + _5 = Lt(copy _4, copy _3); + switchInt(move _5) -> [0: bb1, otherwise: bb4]; } bb1: { + _6 = SubUnchecked(copy _4, copy _3); + StorageDead(_5); + StorageLive(_8); + StorageLive(_7); + _7 = PtrMetadata(copy _1); + _8 = Le(copy _4, move _7); + switchInt(move _8) -> [0: bb2, otherwise: bb3]; + } + + bb2: { + StorageDead(_7); + goto -> bb5; + } + + bb3: { + StorageDead(_7); + StorageLive(_12); + StorageLive(_9); + _9 = &raw const (*_1); + StorageLive(_10); + StorageLive(_11); + _10 = copy _9 as *const u32 (PtrToPtr); + _11 = Offset(copy _10, copy _3); + _12 = *const [u32] from (copy _11, copy _6); + StorageDead(_11); + StorageDead(_10); + StorageDead(_9); + _0 = &(*_12); + StorageDead(_12); + StorageDead(_8); return; } + + bb4: { + StorageDead(_5); + goto -> bb5; + } + + bb5: { + StorageLive(_13); + _13 = PtrMetadata(copy _1); + _14 = core::slice::index::slice_index_fail(move _3, move _4, move _13) -> unwind unreachable; + } } diff --git a/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-unwind.mir index d879d06bb4e47..d4b86b9633acd 100644 --- a/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-unwind.mir +++ b/tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-unwind.mir @@ -4,14 +4,81 @@ fn slice_index_range(_1: &[u32], _2: std::ops::Range) -> &[u32] { debug slice => _1; debug index => _2; let mut _0: &[u32]; + let mut _3: usize; + let mut _4: usize; scope 1 (inlined #[track_caller] core::slice::index::> for [u32]>::index) { + scope 2 (inlined #[track_caller] as SliceIndex<[u32]>>::index) { + let mut _7: usize; + let mut _8: bool; + let mut _9: *const [u32]; + let _12: *const [u32]; + let mut _13: usize; + let mut _14: !; + scope 3 (inlined core::num::::checked_sub) { + let mut _5: bool; + let mut _6: usize; + } + scope 4 (inlined core::slice::index::get_offset_len_noubcheck::) { + let _10: *const u32; + scope 5 { + let _11: *const u32; + scope 6 { + } + } + } + } } bb0: { - _0 = as SliceIndex<[u32]>>::index(move _2, move _1) -> [return: bb1, unwind continue]; + _3 = move (_2.0: usize); + _4 = move (_2.1: usize); + StorageLive(_5); + _5 = Lt(copy _4, copy _3); + switchInt(move _5) -> [0: bb1, otherwise: bb4]; } bb1: { + _6 = SubUnchecked(copy _4, copy _3); + StorageDead(_5); + StorageLive(_8); + StorageLive(_7); + _7 = PtrMetadata(copy _1); + _8 = Le(copy _4, move _7); + switchInt(move _8) -> [0: bb2, otherwise: bb3]; + } + + bb2: { + StorageDead(_7); + goto -> bb5; + } + + bb3: { + StorageDead(_7); + StorageLive(_12); + StorageLive(_9); + _9 = &raw const (*_1); + StorageLive(_10); + StorageLive(_11); + _10 = copy _9 as *const u32 (PtrToPtr); + _11 = Offset(copy _10, copy _3); + _12 = *const [u32] from (copy _11, copy _6); + StorageDead(_11); + StorageDead(_10); + StorageDead(_9); + _0 = &(*_12); + StorageDead(_12); + StorageDead(_8); return; } + + bb4: { + StorageDead(_5); + goto -> bb5; + } + + bb5: { + StorageLive(_13); + _13 = PtrMetadata(copy _1); + _14 = core::slice::index::slice_index_fail(move _3, move _4, move _13) -> unwind continue; + } }