diff options
Diffstat (limited to 'clippy_lints/src/methods/mod.rs')
| -rw-r--r-- | clippy_lints/src/methods/mod.rs | 107 |
1 files changed, 100 insertions, 7 deletions
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index e46739fea34..58ec2213535 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -33,7 +33,6 @@ mod iter_nth_zero; mod iter_skip_next; mod iterator_step_by_zero; mod manual_saturating_arithmetic; -mod manual_split_once; mod manual_str_repeat; mod map_collect_result_unit; mod map_flatten; @@ -50,6 +49,7 @@ mod single_char_insert_string; mod single_char_pattern; mod single_char_push_string; mod skip_while_next; +mod str_splitn; mod string_extend_chars; mod suspicious_map; mod suspicious_splitn; @@ -68,7 +68,7 @@ use bind_instead_of_map::BindInsteadOfMap; use clippy_utils::consts::{constant, Constant}; use clippy_utils::diagnostics::{span_lint, span_lint_and_help}; use clippy_utils::ty::{contains_adt_constructor, contains_ty, implements_trait, is_copy, is_type_diagnostic_item}; -use clippy_utils::{contains_return, get_trait_def_id, in_macro, iter_input_pats, meets_msrv, msrvs, paths, return_ty}; +use clippy_utils::{contains_return, get_trait_def_id, iter_input_pats, meets_msrv, msrvs, paths, return_ty}; use if_chain::if_chain; use rustc_hir as hir; use rustc_hir::def::Res; @@ -99,6 +99,7 @@ declare_clippy_lint! { /// ```rust /// [1, 2, 3].iter().copied(); /// ``` + #[clippy::version = "1.53.0"] pub CLONED_INSTEAD_OF_COPIED, pedantic, "used `cloned` where `copied` could be used instead" @@ -121,6 +122,7 @@ declare_clippy_lint! { /// ```rust /// let nums: Vec<i32> = ["1", "2", "whee!"].iter().filter_map(|x| x.parse().ok()).collect(); /// ``` + #[clippy::version = "1.53.0"] pub FLAT_MAP_OPTION, pedantic, "used `flat_map` where `filter_map` could be used instead" @@ -166,6 +168,7 @@ declare_clippy_lint! { /// // Good /// res.expect("more helpful message"); /// ``` + #[clippy::version = "1.45.0"] pub UNWRAP_USED, restriction, "using `.unwrap()` on `Result` or `Option`, which should at least get a better message using `expect()`" @@ -208,6 +211,7 @@ declare_clippy_lint! { /// res?; /// # Ok::<(), ()>(()) /// ``` + #[clippy::version = "1.45.0"] pub EXPECT_USED, restriction, "using `.expect()` on `Result` or `Option`, which might be better handled" @@ -237,6 +241,7 @@ declare_clippy_lint! { /// } /// } /// ``` + #[clippy::version = "pre 1.29.0"] pub SHOULD_IMPLEMENT_TRAIT, style, "defining a method that should be implementing a std trait" @@ -284,6 +289,7 @@ declare_clippy_lint! { /// } /// } /// ``` + #[clippy::version = "pre 1.29.0"] pub WRONG_SELF_CONVENTION, style, "defining a method named with an established prefix (like \"into_\") that takes `self` with the wrong convention" @@ -310,6 +316,7 @@ declare_clippy_lint! { /// // Good /// x.expect("why did I do this again?"); /// ``` + #[clippy::version = "pre 1.29.0"] pub OK_EXPECT, style, "using `ok().expect()`, which gives worse error messages than calling `expect` directly on the Result" @@ -335,6 +342,7 @@ declare_clippy_lint! { /// // Good /// x.unwrap_or_default(); /// ``` + #[clippy::version = "1.56.0"] pub UNWRAP_OR_ELSE_DEFAULT, style, "using `.unwrap_or_else(Default::default)`, which is more succinctly expressed as `.unwrap_or_default()`" @@ -375,6 +383,7 @@ declare_clippy_lint! { /// // Good /// x.map_or_else(some_function, |a| a + 1); /// ``` + #[clippy::version = "1.45.0"] pub MAP_UNWRAP_OR, pedantic, "using `.map(f).unwrap_or(a)` or `.map(f).unwrap_or_else(func)`, which are more succinctly expressed as `map_or(a, f)` or `map_or_else(a, f)`" @@ -401,6 +410,7 @@ declare_clippy_lint! { /// // Good /// opt.and_then(|a| Some(a + 1)); /// ``` + #[clippy::version = "pre 1.29.0"] pub OPTION_MAP_OR_NONE, style, "using `Option.map_or(None, f)`, which is more succinctly expressed as `and_then(f)`" @@ -426,6 +436,7 @@ declare_clippy_lint! { /// # let r: Result<u32, &str> = Ok(1); /// assert_eq!(Some(1), r.ok()); /// ``` + #[clippy::version = "1.44.0"] pub RESULT_MAP_OR_INTO_OPTION, style, "using `Result.map_or(None, Some)`, which is more succinctly expressed as `ok()`" @@ -458,6 +469,7 @@ declare_clippy_lint! { /// let _ = res().map(|s| if s.len() == 42 { 10 } else { 20 }); /// let _ = res().map_err(|s| if s.len() == 42 { 10 } else { 20 }); /// ``` + #[clippy::version = "1.45.0"] pub BIND_INSTEAD_OF_MAP, complexity, "using `Option.and_then(|x| Some(y))`, which is more succinctly expressed as `map(|x| y)`" @@ -481,6 +493,7 @@ declare_clippy_lint! { /// # let vec = vec![1]; /// vec.iter().find(|x| **x == 0); /// ``` + #[clippy::version = "pre 1.29.0"] pub FILTER_NEXT, complexity, "using `filter(p).next()`, which is more succinctly expressed as `.find(p)`" @@ -504,6 +517,7 @@ declare_clippy_lint! { /// # let vec = vec![1]; /// vec.iter().find(|x| **x != 0); /// ``` + #[clippy::version = "1.42.0"] pub SKIP_WHILE_NEXT, complexity, "using `skip_while(p).next()`, which is more succinctly expressed as `.find(!p)`" @@ -527,8 +541,9 @@ declare_clippy_lint! { /// // Good /// vec.iter().flat_map(|x| x.iter()); /// ``` + #[clippy::version = "1.31.0"] pub MAP_FLATTEN, - pedantic, + complexity, "using combinations of `flatten` and `map` which can usually be written as a single method call" } @@ -553,6 +568,7 @@ declare_clippy_lint! { /// ```rust /// (0_i32..10).filter_map(|n| n.checked_add(1)); /// ``` + #[clippy::version = "1.51.0"] pub MANUAL_FILTER_MAP, complexity, "using `_.filter(_).map(_)` in a way that can be written more simply as `filter_map(_)`" @@ -579,6 +595,7 @@ declare_clippy_lint! { /// ```rust /// (0_i32..10).find_map(|n| n.checked_add(1)); /// ``` + #[clippy::version = "1.51.0"] pub MANUAL_FIND_MAP, complexity, "using `_.find(_).map(_)` in a way that can be written more simply as `find_map(_)`" @@ -601,6 +618,7 @@ declare_clippy_lint! { /// ```rust /// (0..3).find_map(|x| if x == 2 { Some(x) } else { None }); /// ``` + #[clippy::version = "1.36.0"] pub FILTER_MAP_NEXT, pedantic, "using combination of `filter_map` and `next` which can usually be written as a single method call" @@ -623,6 +641,7 @@ declare_clippy_lint! { /// # let iter = vec![vec![0]].into_iter(); /// iter.flatten(); /// ``` + #[clippy::version = "1.39.0"] pub FLAT_MAP_IDENTITY, complexity, "call to `flat_map` where `flatten` is sufficient" @@ -652,6 +671,7 @@ declare_clippy_lint! { /// /// let _ = !"hello world".contains("world"); /// ``` + #[clippy::version = "pre 1.29.0"] pub SEARCH_IS_SOME, complexity, "using an iterator or string search followed by `is_some()` or `is_none()`, which is more succinctly expressed as a call to `any()` or `contains()` (with negation in case of `is_none()`)" @@ -676,6 +696,7 @@ declare_clippy_lint! { /// let name = "foo"; /// if name.starts_with('_') {}; /// ``` + #[clippy::version = "pre 1.29.0"] pub CHARS_NEXT_CMP, style, "using `.chars().next()` to check if a string starts with a char" @@ -710,6 +731,7 @@ declare_clippy_lint! { /// # let foo = Some(String::new()); /// foo.unwrap_or_default(); /// ``` + #[clippy::version = "pre 1.29.0"] pub OR_FUN_CALL, perf, "using any `*or` method with a function call, which suggests `*or_else`" @@ -748,6 +770,7 @@ declare_clippy_lint! { /// # let err_msg = "I'm a teapot"; /// foo.unwrap_or_else(|| panic!("Err {}: {}", err_code, err_msg)); /// ``` + #[clippy::version = "pre 1.29.0"] pub EXPECT_FUN_CALL, perf, "using any `expect` method with a function call" @@ -765,6 +788,7 @@ declare_clippy_lint! { /// ```rust /// 42u64.clone(); /// ``` + #[clippy::version = "pre 1.29.0"] pub CLONE_ON_COPY, complexity, "using `clone` on a `Copy` type" @@ -792,6 +816,7 @@ declare_clippy_lint! { /// // Good /// Rc::clone(&x); /// ``` + #[clippy::version = "pre 1.29.0"] pub CLONE_ON_REF_PTR, restriction, "using 'clone' on a ref-counted pointer" @@ -814,6 +839,7 @@ declare_clippy_lint! { /// println!("{:p} {:p}", *y, z); // prints out the same pointer /// } /// ``` + #[clippy::version = "pre 1.29.0"] pub CLONE_DOUBLE_REF, correctness, "using `clone` on `&&T`" @@ -837,6 +863,7 @@ declare_clippy_lint! { /// // OK, the specialized impl is used /// ["foo", "bar"].iter().map(|&s| s.to_string()); /// ``` + #[clippy::version = "1.40.0"] pub INEFFICIENT_TO_STRING, pedantic, "using `to_string` on `&&T` where `T: ToString`" @@ -898,6 +925,7 @@ declare_clippy_lint! { /// fn new() -> Self; /// } /// ``` + #[clippy::version = "pre 1.29.0"] pub NEW_RET_NO_SELF, style, "not returning type containing `Self` in a `new` method" @@ -922,6 +950,7 @@ declare_clippy_lint! { /// /// // Good /// _.split('x'); + #[clippy::version = "pre 1.29.0"] pub SINGLE_CHAR_PATTERN, perf, "using a single-character str where a char could be used, e.g., `_.split(\"x\")`" @@ -941,6 +970,7 @@ declare_clippy_lint! { /// //.. /// } /// ``` + #[clippy::version = "pre 1.29.0"] pub ITERATOR_STEP_BY_ZERO, correctness, "using `Iterator::step_by(0)`, which will panic at runtime" @@ -962,6 +992,7 @@ declare_clippy_lint! { /// ```rust /// let _ = std::iter::empty::<Option<i32>>().flatten(); /// ``` + #[clippy::version = "1.53.0"] pub OPTION_FILTER_MAP, complexity, "filtering `Option` for `Some` then force-unwrapping, which can be one type-safe operation" @@ -989,6 +1020,7 @@ declare_clippy_lint! { /// # s.insert(1); /// let x = s.iter().next(); /// ``` + #[clippy::version = "1.42.0"] pub ITER_NTH_ZERO, style, "replace `iter.nth(0)` with `iter.next()`" @@ -1015,6 +1047,7 @@ declare_clippy_lint! { /// let bad_vec = some_vec.get(3); /// let bad_slice = &some_vec[..].get(3); /// ``` + #[clippy::version = "pre 1.29.0"] pub ITER_NTH, perf, "using `.iter().nth()` on a standard library type with O(1) element access" @@ -1039,6 +1072,7 @@ declare_clippy_lint! { /// let bad_vec = some_vec.iter().nth(3); /// let bad_slice = &some_vec[..].iter().nth(3); /// ``` + #[clippy::version = "pre 1.29.0"] pub ITER_SKIP_NEXT, style, "using `.skip(x).next()` on an iterator" @@ -1075,6 +1109,7 @@ declare_clippy_lint! { /// let last = some_vec[3]; /// some_vec[0] = 1; /// ``` + #[clippy::version = "pre 1.29.0"] pub GET_UNWRAP, restriction, "using `.get().unwrap()` or `.get_mut().unwrap()` when using `[]` would work instead" @@ -1098,6 +1133,7 @@ declare_clippy_lint! { /// // Good /// a.append(&mut b); /// ``` + #[clippy::version = "1.55.0"] pub EXTEND_WITH_DRAIN, perf, "using vec.append(&mut vec) to move the full range of a vecor to another" @@ -1127,6 +1163,7 @@ declare_clippy_lint! { /// s.push_str(abc); /// s.push_str(&def); /// ``` + #[clippy::version = "pre 1.29.0"] pub STRING_EXTEND_CHARS, style, "using `x.extend(s.chars())` where s is a `&str` or `String`" @@ -1150,6 +1187,7 @@ declare_clippy_lint! { /// let s = [1, 2, 3, 4, 5]; /// let s2: Vec<isize> = s.to_vec(); /// ``` + #[clippy::version = "pre 1.29.0"] pub ITER_CLONED_COLLECT, style, "using `.cloned().collect()` on slice to create a `Vec`" @@ -1174,6 +1212,7 @@ declare_clippy_lint! { /// // Good /// name.ends_with('_') || name.ends_with('-'); /// ``` + #[clippy::version = "pre 1.29.0"] pub CHARS_LAST_CMP, style, "using `.chars().last()` or `.chars().next_back()` to check if a string ends with a char" @@ -1199,6 +1238,7 @@ declare_clippy_lint! { /// let x: &[i32] = &[1, 2, 3, 4, 5]; /// do_stuff(x); /// ``` + #[clippy::version = "pre 1.29.0"] pub USELESS_ASREF, complexity, "using `as_ref` where the types before and after the call are the same" @@ -1221,6 +1261,7 @@ declare_clippy_lint! { /// ```rust /// let _ = (0..3).any(|x| x > 2); /// ``` + #[clippy::version = "pre 1.29.0"] pub UNNECESSARY_FOLD, style, "using `fold` when a more succinct alternative exists" @@ -1250,6 +1291,7 @@ declare_clippy_lint! { /// // As there is no conditional check on the argument this could be written as: /// let _ = (0..4).map(|x| x + 1); /// ``` + #[clippy::version = "1.31.0"] pub UNNECESSARY_FILTER_MAP, complexity, "using `filter_map` when a more succinct alternative exists" @@ -1273,6 +1315,7 @@ declare_clippy_lint! { /// // Good /// let _ = (&vec![3, 4, 5]).iter(); /// ``` + #[clippy::version = "1.32.0"] pub INTO_ITER_ON_REF, style, "using `.into_iter()` on a reference" @@ -1292,6 +1335,7 @@ declare_clippy_lint! { /// ```rust /// let _ = (0..3).map(|x| x + 2).count(); /// ``` + #[clippy::version = "1.39.0"] pub SUSPICIOUS_MAP, suspicious, "suspicious usage of map" @@ -1326,6 +1370,7 @@ declare_clippy_lint! { /// MaybeUninit::uninit().assume_init() /// }; /// ``` + #[clippy::version = "1.39.0"] pub UNINIT_ASSUMED_INIT, correctness, "`MaybeUninit::uninit().assume_init()`" @@ -1354,6 +1399,7 @@ declare_clippy_lint! { /// let add = x.saturating_add(y); /// let sub = x.saturating_sub(y); /// ``` + #[clippy::version = "1.39.0"] pub MANUAL_SATURATING_ARITHMETIC, style, "`.chcked_add/sub(x).unwrap_or(MAX/MIN)`" @@ -1371,6 +1417,7 @@ declare_clippy_lint! { /// ```rust /// unsafe { (&() as *const ()).offset(1) }; /// ``` + #[clippy::version = "1.41.0"] pub ZST_OFFSET, correctness, "Check for offset calculations on raw pointers to zero-sized types" @@ -1412,6 +1459,7 @@ declare_clippy_lint! { /// # Ok::<_, std::io::Error>(()) /// # }; /// ``` + #[clippy::version = "1.42.0"] pub FILETYPE_IS_FILE, restriction, "`FileType::is_file` is not recommended to test for readable file type" @@ -1437,6 +1485,7 @@ declare_clippy_lint! { /// opt.as_deref() /// # ; /// ``` + #[clippy::version = "1.42.0"] pub OPTION_AS_REF_DEREF, complexity, "using `as_ref().map(Deref::deref)`, which is more succinctly expressed as `as_deref()`" @@ -1463,6 +1512,7 @@ declare_clippy_lint! { /// a.get(2); /// b.get(0); /// ``` + #[clippy::version = "1.46.0"] pub ITER_NEXT_SLICE, style, "using `.iter().next()` on a sliced array, which can be shortened to just `.get()`" @@ -1488,6 +1538,7 @@ declare_clippy_lint! { /// string.insert(0, 'R'); /// string.push('R'); /// ``` + #[clippy::version = "1.49.0"] pub SINGLE_CHAR_ADD_STR, style, "`push_str()` or `insert_str()` used with a single-character string literal as parameter" @@ -1526,6 +1577,7 @@ declare_clippy_lint! { /// /// opt.unwrap_or(42); /// ``` + #[clippy::version = "1.48.0"] pub UNNECESSARY_LAZY_EVALUATIONS, style, "using unnecessary lazy evaluation, which can be replaced with simpler eager evaluation" @@ -1546,6 +1598,7 @@ declare_clippy_lint! { /// ```rust /// (0..3).try_for_each(|t| Err(t)); /// ``` + #[clippy::version = "1.49.0"] pub MAP_COLLECT_RESULT_UNIT, style, "using `.map(_).collect::<Result<(),_>()`, which can be replaced with `try_for_each`" @@ -1578,6 +1631,7 @@ declare_clippy_lint! { /// /// assert_eq!(v, vec![5, 5, 5, 5, 5]); /// ``` + #[clippy::version = "1.49.0"] pub FROM_ITER_INSTEAD_OF_COLLECT, pedantic, "use `.collect()` instead of `::from_iter()`" @@ -1607,6 +1661,7 @@ declare_clippy_lint! { /// assert!(x >= 0); /// }); /// ``` + #[clippy::version = "1.51.0"] pub INSPECT_FOR_EACH, complexity, "using `.inspect().for_each()`, which can be replaced with `.for_each()`" @@ -1629,6 +1684,7 @@ declare_clippy_lint! { /// # let iter = vec![Some(1)].into_iter(); /// iter.flatten(); /// ``` + #[clippy::version = "1.52.0"] pub FILTER_MAP_IDENTITY, complexity, "call to `filter_map` where `flatten` is sufficient" @@ -1651,6 +1707,7 @@ declare_clippy_lint! { /// let x = [1, 2, 3]; /// let y: Vec<_> = x.iter().map(|x| 2*x).collect(); /// ``` + #[clippy::version = "1.52.0"] pub MAP_IDENTITY, complexity, "using iterator.map(|x| x)" @@ -1672,6 +1729,7 @@ declare_clippy_lint! { /// // Good /// let _ = "Hello".as_bytes().get(3); /// ``` + #[clippy::version = "1.52.0"] pub BYTES_NTH, style, "replace `.bytes().nth()` with `.as_bytes().get()`" @@ -1697,6 +1755,7 @@ declare_clippy_lint! { /// let b = a.clone(); /// let c = a.clone(); /// ``` + #[clippy::version = "1.52.0"] pub IMPLICIT_CLONE, pedantic, "implicitly cloning a value by invoking a function on its dereferenced type" @@ -1722,6 +1781,7 @@ declare_clippy_lint! { /// let _ = some_vec.len(); /// let _ = &some_vec[..].len(); /// ``` + #[clippy::version = "1.52.0"] pub ITER_COUNT, complexity, "replace `.iter().count()` with `.len()`" @@ -1751,6 +1811,7 @@ declare_clippy_lint! { /// // use x /// } /// ``` + #[clippy::version = "1.54.0"] pub SUSPICIOUS_SPLITN, correctness, "checks for `.splitn(0, ..)` and `.splitn(1, ..)`" @@ -1771,6 +1832,7 @@ declare_clippy_lint! { /// // Good /// let x: String = "x".repeat(10); /// ``` + #[clippy::version = "1.54.0"] pub MANUAL_STR_REPEAT, perf, "manual implementation of `str::repeat`" @@ -1793,11 +1855,36 @@ declare_clippy_lint! { /// let (key, value) = _.split_once('=')?; /// let value = _.split_once('=')?.1; /// ``` + #[clippy::version = "1.57.0"] pub MANUAL_SPLIT_ONCE, complexity, "replace `.splitn(2, pat)` with `.split_once(pat)`" } +declare_clippy_lint! { + /// ### What it does + /// Checks for usages of `str::splitn` (or `str::rsplitn`) where using `str::split` would be the same. + /// ### Why is this bad? + /// The function `split` is simpler and there is no performance difference in these cases, considering + /// that both functions return a lazy iterator. + /// ### Example + /// ```rust + /// // Bad + /// let str = "key=value=add"; + /// let _ = str.splitn(3, '=').next().unwrap(); + /// ``` + /// Use instead: + /// ```rust + /// // Good + /// let str = "key=value=add"; + /// let _ = str.split('=').next().unwrap(); + /// ``` + #[clippy::version = "1.58.0"] + pub NEEDLESS_SPLITN, + complexity, + "usages of `str::splitn` that can be replaced with `str::split`" +} + pub struct Methods { avoid_breaking_exported_api: bool, msrv: Option<RustcVersion>, @@ -1876,7 +1963,8 @@ impl_lint_pass!(Methods => [ SUSPICIOUS_SPLITN, MANUAL_STR_REPEAT, EXTEND_WITH_DRAIN, - MANUAL_SPLIT_ONCE + MANUAL_SPLIT_ONCE, + NEEDLESS_SPLITN ]); /// Extracts a method call name, args, and `Span` of the method name. @@ -1900,7 +1988,7 @@ macro_rules! method_call { impl<'tcx> LateLintPass<'tcx> for Methods { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - if in_macro(expr.span) { + if expr.span.from_expansion() { return; } @@ -2116,7 +2204,9 @@ fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Optio ("assume_init", []) => uninit_assumed_init::check(cx, expr, recv), ("cloned", []) => cloned_instead_of_copied::check(cx, expr, recv, span, msrv), ("collect", []) => match method_call!(recv) { - Some(("cloned", [recv2], _)) => iter_cloned_collect::check(cx, expr, recv2), + Some((name @ ("cloned" | "copied"), [recv2], _)) => { + iter_cloned_collect::check(cx, name, expr, recv2); + }, Some(("map", [m_recv, m_arg], _)) => { map_collect_result_unit::check(cx, expr, m_recv, m_arg, recv); }, @@ -2208,7 +2298,10 @@ fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Optio if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) { suspicious_splitn::check(cx, name, expr, recv, count); if count == 2 && meets_msrv(msrv, &msrvs::STR_SPLIT_ONCE) { - manual_split_once::check(cx, name, expr, recv, pat_arg); + str_splitn::check_manual_split_once(cx, name, expr, recv, pat_arg); + } + if count >= 2 { + str_splitn::check_needless_splitn(cx, name, expr, recv, pat_arg, count); } } }, |