diff options
| -rw-r--r-- | CHANGELOG.md | 1 | ||||
| -rw-r--r-- | clippy_lints/src/from_str_radix_10.rs | 101 | ||||
| -rw-r--r-- | clippy_lints/src/lib.rs | 5 | ||||
| -rw-r--r-- | tests/ui/from_str_radix_10.rs | 52 | ||||
| -rw-r--r-- | tests/ui/from_str_radix_10.stderr | 52 |
5 files changed, 211 insertions, 0 deletions
diff --git a/CHANGELOG.md b/CHANGELOG.md index c59eae5d1c2..2ec8b3d98f8 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -2093,6 +2093,7 @@ Released 2018-09-13 [`forget_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#forget_ref [`from_iter_instead_of_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#from_iter_instead_of_collect [`from_over_into`]: https://rust-lang.github.io/rust-clippy/master/index.html#from_over_into +[`from_str_radix_10`]: https://rust-lang.github.io/rust-clippy/master/index.html#from_str_radix_10 [`future_not_send`]: https://rust-lang.github.io/rust-clippy/master/index.html#future_not_send [`get_last_with_len`]: https://rust-lang.github.io/rust-clippy/master/index.html#get_last_with_len [`get_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap diff --git a/clippy_lints/src/from_str_radix_10.rs b/clippy_lints/src/from_str_radix_10.rs new file mode 100644 index 00000000000..0933f983014 --- /dev/null +++ b/clippy_lints/src/from_str_radix_10.rs @@ -0,0 +1,101 @@ +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir::{def, Expr, ExprKind, PrimTy, QPath, TyKind}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::ty::Ty; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::symbol::sym; + +use crate::utils::is_type_diagnostic_item; +use crate::utils::span_lint_and_sugg; +use crate::utils::sugg::Sugg; + +declare_clippy_lint! { + /// **What it does:** + /// Checks for function invocations of the form `primitive::from_str_radix(s, 10)` + /// + /// **Why is this bad?** + /// This specific common use case can be rewritten as `s.parse::<primitive>()` + /// (and in most cases, the turbofish can be removed), which reduces code length + /// and complexity. + /// + /// **Known problems:** + /// This lint may suggest using (&<expression>).parse() instead of <expression>.parse() directly + /// in some cases, which is correct but adds unnecessary complexity to the code. + /// + /// **Example:** + /// + /// ```ignore + /// let input: &str = get_input(); + /// let num = u16::from_str_radix(input, 10)?; + /// ``` + /// Use instead: + /// ```ignore + /// let input: &str = get_input(); + /// let num: u16 = input.parse()?; + /// ``` + pub FROM_STR_RADIX_10, + style, + "from_str_radix with radix 10" +} + +declare_lint_pass!(FromStrRadix10 => [FROM_STR_RADIX_10]); + +impl LateLintPass<'tcx> for FromStrRadix10 { + fn check_expr(&mut self, cx: &LateContext<'tcx>, exp: &Expr<'tcx>) { + if_chain! { + if let ExprKind::Call(maybe_path, arguments) = &exp.kind; + if let ExprKind::Path(QPath::TypeRelative(ty, pathseg)) = &maybe_path.kind; + + // check if the first part of the path is some integer primitive + if let TyKind::Path(ty_qpath) = &ty.kind; + let ty_res = cx.qpath_res(ty_qpath, ty.hir_id); + if let def::Res::PrimTy(prim_ty) = ty_res; + if matches!(prim_ty, PrimTy::Int(_) | PrimTy::Uint(_)); + + // check if the second part of the path indeed calls the associated + // function `from_str_radix` + if pathseg.ident.name.as_str() == "from_str_radix"; + + // check if the second argument is a primitive `10` + if arguments.len() == 2; + if let ExprKind::Lit(lit) = &arguments[1].kind; + if let rustc_ast::ast::LitKind::Int(10, _) = lit.node; + + then { + let expr = if let ExprKind::AddrOf(_, _, expr) = &arguments[0].kind { + let ty = cx.typeck_results().expr_ty(expr); + if is_ty_stringish(cx, ty) { + expr + } else { + &arguments[0] + } + } else { + &arguments[0] + }; + + let sugg = Sugg::hir_with_applicability( + cx, + expr, + "<string>", + &mut Applicability::MachineApplicable + ).maybe_par(); + + span_lint_and_sugg( + cx, + FROM_STR_RADIX_10, + exp.span, + "this call to `from_str_radix` can be replaced with a call to `str::parse`", + "try", + format!("{}.parse::<{}>()", sugg, prim_ty.name_str()), + Applicability::MaybeIncorrect + ); + } + } + } +} + +/// Checks if a Ty is `String` or `&str` +fn is_ty_stringish(cx: &LateContext<'_>, ty: Ty<'_>) -> bool { + is_type_diagnostic_item(cx, ty, sym::string_type) || is_type_diagnostic_item(cx, ty, sym::str) +} diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 40727980693..67e490584e8 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -211,6 +211,7 @@ mod floating_point_arithmetic; mod format; mod formatting; mod from_over_into; +mod from_str_radix_10; mod functions; mod future_not_send; mod get_last_with_len; @@ -639,6 +640,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &formatting::SUSPICIOUS_ELSE_FORMATTING, &formatting::SUSPICIOUS_UNARY_OP_FORMATTING, &from_over_into::FROM_OVER_INTO, + &from_str_radix_10::FROM_STR_RADIX_10, &functions::DOUBLE_MUST_USE, &functions::MUST_USE_CANDIDATE, &functions::MUST_USE_UNIT, @@ -1259,6 +1261,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(move || box types::PtrAsPtr::new(msrv)); store.register_late_pass(|| box case_sensitive_file_extension_comparisons::CaseSensitiveFileExtensionComparisons); store.register_late_pass(|| box redundant_slicing::RedundantSlicing); + store.register_late_pass(|| box from_str_radix_10::FromStrRadix10); store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![ LintId::of(&arithmetic::FLOAT_ARITHMETIC), @@ -1472,6 +1475,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&formatting::SUSPICIOUS_ELSE_FORMATTING), LintId::of(&formatting::SUSPICIOUS_UNARY_OP_FORMATTING), LintId::of(&from_over_into::FROM_OVER_INTO), + LintId::of(&from_str_radix_10::FROM_STR_RADIX_10), LintId::of(&functions::DOUBLE_MUST_USE), LintId::of(&functions::MUST_USE_UNIT), LintId::of(&functions::NOT_UNSAFE_PTR_ARG_DEREF), @@ -1728,6 +1732,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&formatting::SUSPICIOUS_ELSE_FORMATTING), LintId::of(&formatting::SUSPICIOUS_UNARY_OP_FORMATTING), LintId::of(&from_over_into::FROM_OVER_INTO), + LintId::of(&from_str_radix_10::FROM_STR_RADIX_10), LintId::of(&functions::DOUBLE_MUST_USE), LintId::of(&functions::MUST_USE_UNIT), LintId::of(&functions::RESULT_UNIT_ERR), diff --git a/tests/ui/from_str_radix_10.rs b/tests/ui/from_str_radix_10.rs new file mode 100644 index 00000000000..2f2ea04847a --- /dev/null +++ b/tests/ui/from_str_radix_10.rs @@ -0,0 +1,52 @@ +#![warn(clippy::from_str_radix_10)] + +mod some_mod { + // fake function that shouldn't trigger the lint + pub fn from_str_radix(_: &str, _: u32) -> Result<(), std::num::ParseIntError> { + unimplemented!() + } +} + +// fake function that shouldn't trigger the lint +fn from_str_radix(_: &str, _: u32) -> Result<(), std::num::ParseIntError> { + unimplemented!() +} + +// to test parenthesis addition +struct Test; + +impl std::ops::Add<Test> for Test { + type Output = &'static str; + + fn add(self, _: Self) -> Self::Output { + "304" + } +} + +fn main() -> Result<(), Box<dyn std::error::Error>> { + // all of these should trigger the lint + u32::from_str_radix("30", 10)?; + i64::from_str_radix("24", 10)?; + isize::from_str_radix("100", 10)?; + u8::from_str_radix("7", 10)?; + u16::from_str_radix(&("10".to_owned() + "5"), 10)?; + i128::from_str_radix(Test + Test, 10)?; + + let string = "300"; + i32::from_str_radix(string, 10)?; + + let stringier = "400".to_string(); + i32::from_str_radix(&stringier, 10)?; + + // none of these should trigger the lint + u16::from_str_radix("20", 3)?; + i32::from_str_radix("45", 12)?; + usize::from_str_radix("10", 16)?; + i128::from_str_radix("10", 13)?; + some_mod::from_str_radix("50", 10)?; + some_mod::from_str_radix("50", 6)?; + from_str_radix("50", 10)?; + from_str_radix("50", 6)?; + + Ok(()) +} diff --git a/tests/ui/from_str_radix_10.stderr b/tests/ui/from_str_radix_10.stderr new file mode 100644 index 00000000000..471bf52a9a7 --- /dev/null +++ b/tests/ui/from_str_radix_10.stderr @@ -0,0 +1,52 @@ +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:28:5 + | +LL | u32::from_str_radix("30", 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `"30".parse::<u32>()` + | + = note: `-D clippy::from-str-radix-10` implied by `-D warnings` + +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:29:5 + | +LL | i64::from_str_radix("24", 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `"24".parse::<i64>()` + +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:30:5 + | +LL | isize::from_str_radix("100", 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `"100".parse::<isize>()` + +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:31:5 + | +LL | u8::from_str_radix("7", 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `"7".parse::<u8>()` + +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:32:5 + | +LL | u16::from_str_radix(&("10".to_owned() + "5"), 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `(("10".to_owned() + "5")).parse::<u16>()` + +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:33:5 + | +LL | i128::from_str_radix(Test + Test, 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `(Test + Test).parse::<i128>()` + +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:36:5 + | +LL | i32::from_str_radix(string, 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `string.parse::<i32>()` + +error: this call to `from_str_radix` can be replaced with a call to `str::parse` + --> $DIR/from_str_radix_10.rs:39:5 + | +LL | i32::from_str_radix(&stringier, 10)?; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `stringier.parse::<i32>()` + +error: aborting due to 8 previous errors + |