diff --git a/clippy_lints/src/methods/sliced_string_as_bytes.rs b/clippy_lints/src/methods/sliced_string_as_bytes.rs index 4aff194923a6..fb124f3605b9 100644 --- a/clippy_lints/src/methods/sliced_string_as_bytes.rs +++ b/clippy_lints/src/methods/sliced_string_as_bytes.rs @@ -1,15 +1,21 @@ use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::higher; use clippy_utils::res::MaybeDef; use clippy_utils::source::snippet_with_applicability; use rustc_errors::Applicability; -use rustc_hir::{Expr, ExprKind, LangItem, is_range_literal}; +use rustc_hir::{Expr, ExprKind, LangItem}; use rustc_lint::LateContext; use super::SLICED_STRING_AS_BYTES; +/// Checks if `index` is any type of range except `RangeFull` (i.e. `..`) +fn is_bounded_range_literal(cx: &LateContext<'_>, index: &Expr<'_>) -> bool { + higher::Range::hir(cx, index).is_some_and(|range| Option::or(range.start, range.end).is_some()) +} + pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>) { if let ExprKind::Index(indexed, index, _) = recv.kind - && is_range_literal(index) + && is_bounded_range_literal(cx, index) && let ty = cx.typeck_results().expr_ty(indexed).peel_refs() && (ty.is_str() || ty.is_lang_item(cx, LangItem::String)) { diff --git a/tests/ui/sliced_string_as_bytes.fixed b/tests/ui/sliced_string_as_bytes.fixed index 16c0daff78fd..b5576188b83f 100644 --- a/tests/ui/sliced_string_as_bytes.fixed +++ b/tests/ui/sliced_string_as_bytes.fixed @@ -32,6 +32,12 @@ fn main() { let bytes = &"consectetur adipiscing".as_bytes()[..=5]; //~^ sliced_string_as_bytes + // this lint is a perf lint meant to catch utf-8 alignment checks. + // while the slicing here *is* redundant, it's more like a needless borrow, and shouldn't affect + // perf + let bytes = s[..].as_bytes(); + let bytes = string[..].as_bytes(); + let f = Foo; let bytes = f[0..4].as_bytes(); } diff --git a/tests/ui/sliced_string_as_bytes.rs b/tests/ui/sliced_string_as_bytes.rs index 67985ae5b984..58b8d9290294 100644 --- a/tests/ui/sliced_string_as_bytes.rs +++ b/tests/ui/sliced_string_as_bytes.rs @@ -32,6 +32,12 @@ fn main() { let bytes = "consectetur adipiscing"[..=5].as_bytes(); //~^ sliced_string_as_bytes + // this lint is a perf lint meant to catch utf-8 alignment checks. + // while the slicing here *is* redundant, it's more like a needless borrow, and shouldn't affect + // perf + let bytes = s[..].as_bytes(); + let bytes = string[..].as_bytes(); + let f = Foo; let bytes = f[0..4].as_bytes(); }