diff --git a/CHANGELOG.md b/CHANGELOG.md index 711b7fb79141..d7bcd7a19687 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -5532,6 +5532,7 @@ Released 2018-09-13 [`manual_next_back`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_next_back [`manual_non_exhaustive`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive [`manual_ok_or`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_ok_or +[`manual_pattern_char_comparison`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_pattern_char_comparison [`manual_range_contains`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains [`manual_range_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_patterns [`manual_rem_euclid`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_rem_euclid diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index a9f2dd4499a3..7e43a99e9f24 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -448,7 +448,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::methods::SEEK_TO_START_INSTEAD_OF_REWIND_INFO, crate::methods::SHOULD_IMPLEMENT_TRAIT_INFO, crate::methods::SINGLE_CHAR_ADD_STR_INFO, - crate::methods::SINGLE_CHAR_PATTERN_INFO, crate::methods::SKIP_WHILE_NEXT_INFO, crate::methods::STABLE_SORT_PRIMITIVE_INFO, crate::methods::STRING_EXTEND_CHARS_INFO, @@ -656,6 +655,8 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::std_instead_of_core::ALLOC_INSTEAD_OF_CORE_INFO, crate::std_instead_of_core::STD_INSTEAD_OF_ALLOC_INFO, crate::std_instead_of_core::STD_INSTEAD_OF_CORE_INFO, + crate::string_patterns::MANUAL_PATTERN_CHAR_COMPARISON_INFO, + crate::string_patterns::SINGLE_CHAR_PATTERN_INFO, crate::strings::STRING_ADD_INFO, crate::strings::STRING_ADD_ASSIGN_INFO, crate::strings::STRING_FROM_UTF8_AS_BYTES_INFO, diff --git a/clippy_lints/src/float_literal.rs b/clippy_lints/src/float_literal.rs index 4ec9bd757ff4..4d301daabe4c 100644 --- a/clippy_lints/src/float_literal.rs +++ b/clippy_lints/src/float_literal.rs @@ -103,7 +103,7 @@ impl<'tcx> LateLintPass<'tcx> for FloatLiteral { return; } - if is_whole && !sym_str.contains(|c| c == 'e' || c == 'E') { + if is_whole && !sym_str.contains(['e', 'E']) { // Normalize the literal by stripping the fractional portion if sym_str.split('.').next().unwrap() != float_str { // If the type suffix is missing the suggestion would be diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 6946c2986f48..c65581d5203e 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -326,6 +326,7 @@ mod size_of_in_element_count; mod size_of_ref; mod slow_vector_initialization; mod std_instead_of_core; +mod string_patterns; mod strings; mod strlen_on_c_strings; mod suspicious_operation_groupings; @@ -1167,6 +1168,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) { ..Default::default() }) }); + store.register_late_pass(|_| Box::new(string_patterns::StringPatterns)); // add lints here, do not remove this comment, it's used in `new_lint` } diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index c3699d6341a0..6200716afbe9 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -94,7 +94,6 @@ mod seek_from_current; mod seek_to_start_instead_of_rewind; mod single_char_add_str; mod single_char_insert_string; -mod single_char_pattern; mod single_char_push_string; mod skip_while_next; mod stable_sort_primitive; @@ -1141,38 +1140,6 @@ declare_clippy_lint! { "not returning type containing `Self` in a `new` method" } -declare_clippy_lint! { - /// ### What it does - /// Checks for string methods that receive a single-character - /// `str` as an argument, e.g., `_.split("x")`. - /// - /// ### Why is this bad? - /// While this can make a perf difference on some systems, - /// benchmarks have proven inconclusive. But at least using a - /// char literal makes it clear that we are looking at a single - /// character. - /// - /// ### Known problems - /// Does not catch multi-byte unicode characters. This is by - /// design, on many machines, splitting by a non-ascii char is - /// actually slower. Please do your own measurements instead of - /// relying solely on the results of this lint. - /// - /// ### Example - /// ```rust,ignore - /// _.split("x"); - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// _.split('x'); - /// ``` - #[clippy::version = "pre 1.29.0"] - pub SINGLE_CHAR_PATTERN, - pedantic, - "using a single-character str where a char could be used, e.g., `_.split(\"x\")`" -} - declare_clippy_lint! { /// ### What it does /// Checks for calling `.step_by(0)` on iterators which panics. @@ -4169,7 +4136,6 @@ impl_lint_pass!(Methods => [ FLAT_MAP_OPTION, INEFFICIENT_TO_STRING, NEW_RET_NO_SELF, - SINGLE_CHAR_PATTERN, SINGLE_CHAR_ADD_STR, SEARCH_IS_SOME, FILTER_NEXT, @@ -4324,7 +4290,6 @@ impl<'tcx> LateLintPass<'tcx> for Methods { inefficient_to_string::check(cx, expr, method_call.ident.name, receiver, args); single_char_add_str::check(cx, expr, receiver, args); into_iter_on_ref::check(cx, expr, method_span, method_call.ident.name, receiver); - single_char_pattern::check(cx, expr, method_call.ident.name, receiver, args); unnecessary_to_owned::check(cx, expr, method_call.ident.name, receiver, args, &self.msrv); }, ExprKind::Binary(op, lhs, rhs) if op.node == hir::BinOpKind::Eq || op.node == hir::BinOpKind::Ne => { diff --git a/clippy_lints/src/methods/path_buf_push_overwrite.rs b/clippy_lints/src/methods/path_buf_push_overwrite.rs index 04a27cc98f3c..2d3007e50b81 100644 --- a/clippy_lints/src/methods/path_buf_push_overwrite.rs +++ b/clippy_lints/src/methods/path_buf_push_overwrite.rs @@ -27,7 +27,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, arg: &'t lit.span, "calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition", "try", - format!("\"{}\"", pushed_path_lit.trim_start_matches(|c| c == '/' || c == '\\')), + format!("\"{}\"", pushed_path_lit.trim_start_matches(['/', '\\'])), Applicability::MachineApplicable, ); } diff --git a/clippy_lints/src/methods/single_char_insert_string.rs b/clippy_lints/src/methods/single_char_insert_string.rs index ba9ef9c84f9c..e2f76ac114c6 100644 --- a/clippy_lints/src/methods/single_char_insert_string.rs +++ b/clippy_lints/src/methods/single_char_insert_string.rs @@ -1,6 +1,5 @@ -use super::utils::get_hint_if_single_char_arg; use clippy_utils::diagnostics::span_lint_and_sugg; -use clippy_utils::source::snippet_with_applicability; +use clippy_utils::source::{snippet_with_applicability, str_literal_to_char_literal}; use rustc_ast::BorrowKind; use rustc_errors::Applicability; use rustc_hir::{self as hir, ExprKind}; @@ -11,7 +10,7 @@ use super::SINGLE_CHAR_ADD_STR; /// lint for length-1 `str`s as argument for `insert_str` pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { let mut applicability = Applicability::MachineApplicable; - if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[1], &mut applicability, false) { + if let Some(extension_string) = str_literal_to_char_literal(cx, &args[1], &mut applicability, false) { let base_string_snippet = snippet_with_applicability(cx, receiver.span.source_callsite(), "_", &mut applicability); let pos_arg = snippet_with_applicability(cx, args[0].span, "..", &mut applicability); diff --git a/clippy_lints/src/methods/single_char_pattern.rs b/clippy_lints/src/methods/single_char_pattern.rs deleted file mode 100644 index 982a7901c453..000000000000 --- a/clippy_lints/src/methods/single_char_pattern.rs +++ /dev/null @@ -1,64 +0,0 @@ -use super::utils::get_hint_if_single_char_arg; -use clippy_utils::diagnostics::span_lint_and_sugg; -use rustc_errors::Applicability; -use rustc_hir as hir; -use rustc_lint::LateContext; -use rustc_middle::ty; -use rustc_span::symbol::Symbol; - -use super::SINGLE_CHAR_PATTERN; - -const PATTERN_METHODS: [(&str, usize); 22] = [ - ("contains", 0), - ("starts_with", 0), - ("ends_with", 0), - ("find", 0), - ("rfind", 0), - ("split", 0), - ("split_inclusive", 0), - ("rsplit", 0), - ("split_terminator", 0), - ("rsplit_terminator", 0), - ("splitn", 1), - ("rsplitn", 1), - ("split_once", 0), - ("rsplit_once", 0), - ("matches", 0), - ("rmatches", 0), - ("match_indices", 0), - ("rmatch_indices", 0), - ("trim_start_matches", 0), - ("trim_end_matches", 0), - ("replace", 0), - ("replacen", 0), -]; - -/// lint for length-1 `str`s for methods in `PATTERN_METHODS` -pub(super) fn check( - cx: &LateContext<'_>, - _expr: &hir::Expr<'_>, - method_name: Symbol, - receiver: &hir::Expr<'_>, - args: &[hir::Expr<'_>], -) { - for &(method, pos) in &PATTERN_METHODS { - if let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty_adjusted(receiver).kind() - && ty.is_str() - && method_name.as_str() == method - && args.len() > pos - && let arg = &args[pos] - && let mut applicability = Applicability::MachineApplicable - && let Some(hint) = get_hint_if_single_char_arg(cx, arg, &mut applicability, true) - { - span_lint_and_sugg( - cx, - SINGLE_CHAR_PATTERN, - arg.span, - "single-character string constant used as pattern", - "consider using a `char`", - hint, - applicability, - ); - } - } -} diff --git a/clippy_lints/src/methods/single_char_push_string.rs b/clippy_lints/src/methods/single_char_push_string.rs index f00a5ab455e8..4ae8634305da 100644 --- a/clippy_lints/src/methods/single_char_push_string.rs +++ b/clippy_lints/src/methods/single_char_push_string.rs @@ -1,6 +1,5 @@ -use super::utils::get_hint_if_single_char_arg; use clippy_utils::diagnostics::span_lint_and_sugg; -use clippy_utils::source::snippet_with_applicability; +use clippy_utils::source::{snippet_with_applicability, str_literal_to_char_literal}; use rustc_ast::BorrowKind; use rustc_errors::Applicability; use rustc_hir::{self as hir, ExprKind}; @@ -11,7 +10,7 @@ use super::SINGLE_CHAR_ADD_STR; /// lint for length-1 `str`s as argument for `push_str` pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { let mut applicability = Applicability::MachineApplicable; - if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[0], &mut applicability, false) { + if let Some(extension_string) = str_literal_to_char_literal(cx, &args[0], &mut applicability, false) { let base_string_snippet = snippet_with_applicability(cx, receiver.span.source_callsite(), "..", &mut applicability); let sugg = format!("{base_string_snippet}.push({extension_string})"); diff --git a/clippy_lints/src/methods/utils.rs b/clippy_lints/src/methods/utils.rs index 5d58c73f8b20..0d2b0a313176 100644 --- a/clippy_lints/src/methods/utils.rs +++ b/clippy_lints/src/methods/utils.rs @@ -1,8 +1,5 @@ -use clippy_utils::source::snippet_with_applicability; use clippy_utils::ty::is_type_diagnostic_item; use clippy_utils::{get_parent_expr, path_to_local_id, usage}; -use rustc_ast::ast; -use rustc_errors::Applicability; use rustc_hir::intravisit::{walk_expr, Visitor}; use rustc_hir::{BorrowKind, Expr, ExprKind, HirId, Mutability, Pat, QPath, Stmt, StmtKind}; use rustc_lint::LateContext; @@ -49,48 +46,6 @@ pub(super) fn derefs_to_slice<'tcx>( } } -pub(super) fn get_hint_if_single_char_arg( - cx: &LateContext<'_>, - arg: &Expr<'_>, - applicability: &mut Applicability, - ascii_only: bool, -) -> Option { - if let ExprKind::Lit(lit) = &arg.kind - && let ast::LitKind::Str(r, style) = lit.node - && let string = r.as_str() - && let len = if ascii_only { - string.len() - } else { - string.chars().count() - } - && len == 1 - { - let snip = snippet_with_applicability(cx, arg.span, string, applicability); - let ch = if let ast::StrStyle::Raw(nhash) = style { - let nhash = nhash as usize; - // for raw string: r##"a"## - &snip[(nhash + 2)..(snip.len() - 1 - nhash)] - } else { - // for regular string: "a" - &snip[1..(snip.len() - 1)] - }; - - let hint = format!( - "'{}'", - match ch { - "'" => "\\'", - r"\" => "\\\\", - "\\\"" => "\"", // no need to escape `"` in `'"'` - _ => ch, - } - ); - - Some(hint) - } else { - None - } -} - /// The core logic of `check_for_loop_iter` in `unnecessary_iter_cloned.rs`, this function wraps a /// use of `CloneOrCopyVisitor`. pub(super) fn clone_or_copy_needed<'tcx>( diff --git a/clippy_lints/src/misc_early/zero_prefixed_literal.rs b/clippy_lints/src/misc_early/zero_prefixed_literal.rs index 4f9578d1b257..61f4684c9e37 100644 --- a/clippy_lints/src/misc_early/zero_prefixed_literal.rs +++ b/clippy_lints/src/misc_early/zero_prefixed_literal.rs @@ -6,7 +6,7 @@ use rustc_span::Span; use super::ZERO_PREFIXED_LITERAL; pub(super) fn check(cx: &EarlyContext<'_>, lit_span: Span, lit_snip: &str) { - let trimmed_lit_snip = lit_snip.trim_start_matches(|c| c == '_' || c == '0'); + let trimmed_lit_snip = lit_snip.trim_start_matches(['_', '0']); span_lint_and_then( cx, ZERO_PREFIXED_LITERAL, @@ -20,7 +20,7 @@ pub(super) fn check(cx: &EarlyContext<'_>, lit_span: Span, lit_snip: &str) { Applicability::MaybeIncorrect, ); // do not advise to use octal form if the literal cannot be expressed in base 8. - if !lit_snip.contains(|c| c == '8' || c == '9') { + if !lit_snip.contains(['8', '9']) { diag.span_suggestion( lit_span, "if you mean to use an octal constant, use `0o`", diff --git a/clippy_lints/src/string_patterns.rs b/clippy_lints/src/string_patterns.rs new file mode 100644 index 000000000000..64b5b8f9f27b --- /dev/null +++ b/clippy_lints/src/string_patterns.rs @@ -0,0 +1,227 @@ +use std::ops::ControlFlow; + +use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then}; +use clippy_utils::eager_or_lazy::switch_to_eager_eval; +use clippy_utils::macros::matching_root_macro_call; +use clippy_utils::path_to_local_id; +use clippy_utils::source::{snippet, str_literal_to_char_literal}; +use clippy_utils::visitors::{for_each_expr, Descend}; +use itertools::Itertools; +use rustc_ast::{BinOpKind, LitKind}; +use rustc_errors::Applicability; +use rustc_hir::{Expr, ExprKind, PatKind}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::ty; +use rustc_session::declare_lint_pass; +use rustc_span::{sym, Span}; + +declare_clippy_lint! { + /// ### What it does + /// Checks for manual `char` comparison in string patterns + /// + /// ### Why is this bad? + /// This can be written more concisely using a `char` or an array of `char`. + /// This is more readable and more optimized when comparing to only one `char`. + /// + /// ### Example + /// ```no_run + /// "Hello World!".trim_end_matches(|c| c == '.' || c == ',' || c == '!' || c == '?'); + /// ``` + /// Use instead: + /// ```no_run + /// "Hello World!".trim_end_matches(['.', ',', '!', '?']); + /// ``` + #[clippy::version = "1.80.0"] + pub MANUAL_PATTERN_CHAR_COMPARISON, + style, + "manual char comparison in string patterns" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for string methods that receive a single-character + /// `str` as an argument, e.g., `_.split("x")`. + /// + /// ### Why is this bad? + /// While this can make a perf difference on some systems, + /// benchmarks have proven inconclusive. But at least using a + /// char literal makes it clear that we are looking at a single + /// character. + /// + /// ### Known problems + /// Does not catch multi-byte unicode characters. This is by + /// design, on many machines, splitting by a non-ascii char is + /// actually slower. Please do your own measurements instead of + /// relying solely on the results of this lint. + /// + /// ### Example + /// ```rust,ignore + /// _.split("x"); + /// ``` + /// + /// Use instead: + /// ```rust,ignore + /// _.split('x'); + /// ``` + #[clippy::version = "pre 1.29.0"] + pub SINGLE_CHAR_PATTERN, + pedantic, + "using a single-character str where a char could be used, e.g., `_.split(\"x\")`" +} + +declare_lint_pass!(StringPatterns => [MANUAL_PATTERN_CHAR_COMPARISON, SINGLE_CHAR_PATTERN]); + +const PATTERN_METHODS: [(&str, usize); 22] = [ + ("contains", 0), + ("starts_with", 0), + ("ends_with", 0), + ("find", 0), + ("rfind", 0), + ("split", 0), + ("split_inclusive", 0), + ("rsplit", 0), + ("split_terminator", 0), + ("rsplit_terminator", 0), + ("splitn", 1), + ("rsplitn", 1), + ("split_once", 0), + ("rsplit_once", 0), + ("matches", 0), + ("rmatches", 0), + ("match_indices", 0), + ("rmatch_indices", 0), + ("trim_start_matches", 0), + ("trim_end_matches", 0), + ("replace", 0), + ("replacen", 0), +]; + +fn check_single_char_pattern_lint(cx: &LateContext<'_>, arg: &Expr<'_>) { + let mut applicability = Applicability::MachineApplicable; + if let Some(hint) = str_literal_to_char_literal(cx, arg, &mut applicability, true) { + span_lint_and_sugg( + cx, + SINGLE_CHAR_PATTERN, + arg.span, + "single-character string constant used as pattern", + "consider using a `char`", + hint, + applicability, + ); + } +} + +fn get_char_span<'tcx>(cx: &'_ LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option { + if cx.typeck_results().expr_ty_adjusted(expr).is_char() + && !expr.span.from_expansion() + && switch_to_eager_eval(cx, expr) + { + Some(expr.span) + } else { + None + } +} + +fn check_manual_pattern_char_comparison(cx: &LateContext<'_>, method_arg: &Expr<'_>) { + if let ExprKind::Closure(closure) = method_arg.kind + && let body = cx.tcx.hir().body(closure.body) + && let Some(PatKind::Binding(_, binding, ..)) = body.params.first().map(|p| p.pat.kind) + { + let mut set_char_spans: Vec = Vec::new(); + + // We want to retrieve all the comparisons done. + // They are ordered in a nested way and so we need to traverse the AST to collect them all. + if for_each_expr(cx, body.value, |sub_expr| -> ControlFlow<(), Descend> { + match sub_expr.kind { + ExprKind::Binary(op, left, right) if op.node == BinOpKind::Eq => { + if path_to_local_id(left, binding) + && let Some(span) = get_char_span(cx, right) + { + set_char_spans.push(span); + ControlFlow::Continue(Descend::No) + } else if path_to_local_id(right, binding) + && let Some(span) = get_char_span(cx, left) + { + set_char_spans.push(span); + ControlFlow::Continue(Descend::No) + } else { + ControlFlow::Break(()) + } + }, + ExprKind::Binary(op, _, _) if op.node == BinOpKind::Or => ControlFlow::Continue(Descend::Yes), + ExprKind::Match(match_value, [arm, _], _) => { + if matching_root_macro_call(cx, sub_expr.span, sym::matches_macro).is_none() + || arm.guard.is_some() + || !path_to_local_id(match_value, binding) + { + return ControlFlow::Break(()); + } + if arm.pat.walk_short(|pat| match pat.kind { + PatKind::Lit(expr) if let ExprKind::Lit(lit) = expr.kind => { + if let LitKind::Char(_) = lit.node { + set_char_spans.push(lit.span); + } + true + }, + PatKind::Or(_) => true, + _ => false, + }) { + ControlFlow::Continue(Descend::No) + } else { + ControlFlow::Break(()) + } + }, + _ => ControlFlow::Break(()), + } + }) + .is_some() + { + return; + } + span_lint_and_then( + cx, + MANUAL_PATTERN_CHAR_COMPARISON, + method_arg.span, + "this manual char comparison can be written more succinctly", + |diag| { + if let [set_char_span] = set_char_spans[..] { + diag.span_suggestion( + method_arg.span, + "consider using a `char`", + snippet(cx, set_char_span, "c"), + Applicability::MachineApplicable, + ); + } else { + diag.span_suggestion( + method_arg.span, + "consider using an array of `char`", + format!( + "[{}]", + set_char_spans.into_iter().map(|span| snippet(cx, span, "c")).join(", ") + ), + Applicability::MachineApplicable, + ); + } + }, + ); + } +} + +impl<'tcx> LateLintPass<'tcx> for StringPatterns { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { + if !expr.span.from_expansion() + && let ExprKind::MethodCall(method, receiver, args, _) = expr.kind + && let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty_adjusted(receiver).kind() + && ty.is_str() + && let method_name = method.ident.name.as_str() + && let Some(&(_, pos)) = PATTERN_METHODS + .iter() + .find(|(array_method_name, _)| *array_method_name == method_name) + && let Some(arg) = args.get(pos) + { + check_single_char_pattern_lint(cx, arg); + + check_manual_pattern_char_comparison(cx, arg); + } + } +} diff --git a/clippy_utils/src/source.rs b/clippy_utils/src/source.rs index 69f593fe04ac..b7ff7ebe9105 100644 --- a/clippy_utils/src/source.rs +++ b/clippy_utils/src/source.rs @@ -2,6 +2,7 @@ #![allow(clippy::module_name_repetitions)] +use rustc_ast::{LitKind, StrStyle}; use rustc_data_structures::sync::Lrc; use rustc_errors::Applicability; use rustc_hir::{BlockCheckMode, Expr, ExprKind, UnsafeSource}; @@ -500,6 +501,50 @@ pub fn expand_past_previous_comma(cx: &LateContext<'_>, span: Span) -> Span { extended.with_lo(extended.lo() - BytePos(1)) } +/// Converts `expr` to a `char` literal if it's a `str` literal containing a single +/// character (or a single byte with `ascii_only`) +pub fn str_literal_to_char_literal( + cx: &LateContext<'_>, + expr: &Expr<'_>, + applicability: &mut Applicability, + ascii_only: bool, +) -> Option { + if let ExprKind::Lit(lit) = &expr.kind + && let LitKind::Str(r, style) = lit.node + && let string = r.as_str() + && let len = if ascii_only { + string.len() + } else { + string.chars().count() + } + && len == 1 + { + let snip = snippet_with_applicability(cx, expr.span, string, applicability); + let ch = if let StrStyle::Raw(nhash) = style { + let nhash = nhash as usize; + // for raw string: r##"a"## + &snip[(nhash + 2)..(snip.len() - 1 - nhash)] + } else { + // for regular string: "a" + &snip[1..(snip.len() - 1)] + }; + + let hint = format!( + "'{}'", + match ch { + "'" => "\\'", + r"\" => "\\\\", + "\\\"" => "\"", // no need to escape `"` in `'"'` + _ => ch, + } + ); + + Some(hint) + } else { + None + } +} + #[cfg(test)] mod test { use super::{reindent_multiline, without_block_comments}; diff --git a/tests/ui/manual_pattern_char_comparison.fixed b/tests/ui/manual_pattern_char_comparison.fixed new file mode 100644 index 000000000000..588226b87e87 --- /dev/null +++ b/tests/ui/manual_pattern_char_comparison.fixed @@ -0,0 +1,49 @@ +#![warn(clippy::manual_pattern_char_comparison)] + +struct NotStr; + +impl NotStr { + fn find(&self, _: impl FnMut(char) -> bool) {} +} + +fn main() { + let sentence = "Hello, world!"; + sentence.trim_end_matches(['.', ',', '!', '?']); + sentence.split(['\n', 'X']); + sentence.split(['\n', 'X']); + sentence.splitn(3, 'X'); + sentence.splitn(3, |c: char| c.is_whitespace() || c == 'X'); + let char_compare = 'X'; + sentence.splitn(3, char_compare); + sentence.split(['\n', 'X', 'Y']); + sentence.splitn(3, 'X'); + sentence.splitn(3, ['X', 'W']); + sentence.find('🎈'); + + let not_str = NotStr; + not_str.find(|c: char| c == 'X'); + + "".find(|c| c == 'a' || c > 'z'); + + let x = true; + "".find(|c| c == 'a' || x || c == 'b'); + + let d = 'd'; + "".find(|c| c == 'a' || d == 'b'); + + "".find(|c| match c { + 'a' | 'b' => true, + _ => c.is_ascii(), + }); + + "".find(|c| matches!(c, 'a' | 'b' if false)); + + "".find(|c| matches!(c, 'a' | '1'..'4')); + "".find(|c| c == 'a' || matches!(c, '1'..'4')); + macro_rules! m { + ($e:expr) => { + $e == '?' + }; + } + "".find(|c| m!(c)); +} diff --git a/tests/ui/manual_pattern_char_comparison.rs b/tests/ui/manual_pattern_char_comparison.rs new file mode 100644 index 000000000000..5078f3ee27f3 --- /dev/null +++ b/tests/ui/manual_pattern_char_comparison.rs @@ -0,0 +1,49 @@ +#![warn(clippy::manual_pattern_char_comparison)] + +struct NotStr; + +impl NotStr { + fn find(&self, _: impl FnMut(char) -> bool) {} +} + +fn main() { + let sentence = "Hello, world!"; + sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?'); + sentence.split(|c: char| c == '\n' || c == 'X'); + sentence.split(|c| c == '\n' || c == 'X'); + sentence.splitn(3, |c: char| c == 'X'); + sentence.splitn(3, |c: char| c.is_whitespace() || c == 'X'); + let char_compare = 'X'; + sentence.splitn(3, |c: char| c == char_compare); + sentence.split(|c: char| matches!(c, '\n' | 'X' | 'Y')); + sentence.splitn(3, |c: char| matches!(c, 'X')); + sentence.splitn(3, |c: char| matches!(c, 'X' | 'W')); + sentence.find(|c| c == '🎈'); + + let not_str = NotStr; + not_str.find(|c: char| c == 'X'); + + "".find(|c| c == 'a' || c > 'z'); + + let x = true; + "".find(|c| c == 'a' || x || c == 'b'); + + let d = 'd'; + "".find(|c| c == 'a' || d == 'b'); + + "".find(|c| match c { + 'a' | 'b' => true, + _ => c.is_ascii(), + }); + + "".find(|c| matches!(c, 'a' | 'b' if false)); + + "".find(|c| matches!(c, 'a' | '1'..'4')); + "".find(|c| c == 'a' || matches!(c, '1'..'4')); + macro_rules! m { + ($e:expr) => { + $e == '?' + }; + } + "".find(|c| m!(c)); +} diff --git a/tests/ui/manual_pattern_char_comparison.stderr b/tests/ui/manual_pattern_char_comparison.stderr new file mode 100644 index 000000000000..b6b51794a11f --- /dev/null +++ b/tests/ui/manual_pattern_char_comparison.stderr @@ -0,0 +1,59 @@ +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:11:31 + | +LL | sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?'); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['.', ',', '!', '?']` + | + = note: `-D clippy::manual-pattern-char-comparison` implied by `-D warnings` + = help: to override `-D warnings` add `#[allow(clippy::manual_pattern_char_comparison)]` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:12:20 + | +LL | sentence.split(|c: char| c == '\n' || c == 'X'); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['\n', 'X']` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:13:20 + | +LL | sentence.split(|c| c == '\n' || c == 'X'); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['\n', 'X']` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:14:24 + | +LL | sentence.splitn(3, |c: char| c == 'X'); + | ^^^^^^^^^^^^^^^^^^ help: consider using a `char`: `'X'` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:17:24 + | +LL | sentence.splitn(3, |c: char| c == char_compare); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using a `char`: `char_compare` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:18:20 + | +LL | sentence.split(|c: char| matches!(c, '\n' | 'X' | 'Y')); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['\n', 'X', 'Y']` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:19:24 + | +LL | sentence.splitn(3, |c: char| matches!(c, 'X')); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using a `char`: `'X'` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:20:24 + | +LL | sentence.splitn(3, |c: char| matches!(c, 'X' | 'W')); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['X', 'W']` + +error: this manual char comparison can be written more succinctly + --> tests/ui/manual_pattern_char_comparison.rs:21:19 + | +LL | sentence.find(|c| c == '🎈'); + | ^^^^^^^^^^^^^ help: consider using a `char`: `'🎈'` + +error: aborting due to 9 previous errors + diff --git a/tests/ui/search_is_some.rs b/tests/ui/search_is_some.rs index e8a0920b645d..9a9aaba56adc 100644 --- a/tests/ui/search_is_some.rs +++ b/tests/ui/search_is_some.rs @@ -1,5 +1,6 @@ //@aux-build:option_helpers.rs #![warn(clippy::search_is_some)] +#![allow(clippy::manual_pattern_char_comparison)] #![allow(clippy::useless_vec)] #![allow(dead_code)] extern crate option_helpers; diff --git a/tests/ui/search_is_some.stderr b/tests/ui/search_is_some.stderr index b5f84d23284a..b5ef55341770 100644 --- a/tests/ui/search_is_some.stderr +++ b/tests/ui/search_is_some.stderr @@ -1,5 +1,5 @@ error: called `is_some()` after searching an `Iterator` with `find` - --> tests/ui/search_is_some.rs:15:13 + --> tests/ui/search_is_some.rs:16:13 | LL | let _ = v.iter().find(|&x| { | _____________^ @@ -13,7 +13,7 @@ LL | | ).is_some(); = help: to override `-D warnings` add `#[allow(clippy::search_is_some)]` error: called `is_some()` after searching an `Iterator` with `position` - --> tests/ui/search_is_some.rs:21:13 + --> tests/ui/search_is_some.rs:22:13 | LL | let _ = v.iter().position(|&x| { | _____________^ @@ -25,7 +25,7 @@ LL | | ).is_some(); = help: this is more succinctly expressed by calling `any()` error: called `is_some()` after searching an `Iterator` with `rposition` - --> tests/ui/search_is_some.rs:27:13 + --> tests/ui/search_is_some.rs:28:13 | LL | let _ = v.iter().rposition(|&x| { | _____________^ @@ -37,13 +37,13 @@ LL | | ).is_some(); = help: this is more succinctly expressed by calling `any()` error: called `is_some()` after searching an `Iterator` with `find` - --> tests/ui/search_is_some.rs:42:20 + --> tests/ui/search_is_some.rs:43:20 | LL | let _ = (0..1).find(some_closure).is_some(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `any(some_closure)` error: called `is_none()` after searching an `Iterator` with `find` - --> tests/ui/search_is_some.rs:52:13 + --> tests/ui/search_is_some.rs:53:13 | LL | let _ = v.iter().find(|&x| { | _____________^ @@ -55,7 +55,7 @@ LL | | ).is_none(); = help: this is more succinctly expressed by calling `any()` with negation error: called `is_none()` after searching an `Iterator` with `position` - --> tests/ui/search_is_some.rs:58:13 + --> tests/ui/search_is_some.rs:59:13 | LL | let _ = v.iter().position(|&x| { | _____________^ @@ -67,7 +67,7 @@ LL | | ).is_none(); = help: this is more succinctly expressed by calling `any()` with negation error: called `is_none()` after searching an `Iterator` with `rposition` - --> tests/ui/search_is_some.rs:64:13 + --> tests/ui/search_is_some.rs:65:13 | LL | let _ = v.iter().rposition(|&x| { | _____________^ @@ -79,7 +79,7 @@ LL | | ).is_none(); = help: this is more succinctly expressed by calling `any()` with negation error: called `is_none()` after searching an `Iterator` with `find` - --> tests/ui/search_is_some.rs:79:13 + --> tests/ui/search_is_some.rs:80:13 | LL | let _ = (0..1).find(some_closure).is_none(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `!(0..1).any(some_closure)`