X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fzero_div_zero.rs;h=ec380360e547e1f0297916427edb84fa8d40a71c;hb=6d1225981177587fbb68d9c4902c770c3dbaafb0;hp=5ff9fb9ffd5dc9cfa729de681d59c9815c4469e1;hpb=55781f594992521667dce5ae3a703e931962a25b;p=rust.git diff --git a/clippy_lints/src/zero_div_zero.rs b/clippy_lints/src/zero_div_zero.rs index 5ff9fb9ffd5..ec380360e54 100644 --- a/clippy_lints/src/zero_div_zero.rs +++ b/clippy_lints/src/zero_div_zero.rs @@ -1,57 +1,62 @@ -use consts::{constant_simple, Constant, FloatWidth}; -use rustc::lint::*; +use crate::consts::{constant_simple, Constant}; +use crate::utils::span_help_and_lint; +use if_chain::if_chain; +use rustc::declare_lint_pass; use rustc::hir::*; -use utils::span_help_and_lint; +use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; +use rustc_session::declare_tool_lint; -/// **What it does:** Checks for `0.0 / 0.0`. -/// -/// **Why is this bad?** It's less readable than `std::f32::NAN` or -/// `std::f64::NAN`. -/// -/// **Known problems:** None. -/// -/// **Example:** -/// ```rust -/// 0.0f32 / 0.0 -/// ``` -declare_lint! { +declare_clippy_lint! { + /// **What it does:** Checks for `0.0 / 0.0`. + /// + /// **Why is this bad?** It's less readable than `std::f32::NAN` or + /// `std::f64::NAN`. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// ```rust + /// 0.0f32 / 0.0; + /// ``` pub ZERO_DIVIDED_BY_ZERO, - Warn, + complexity, "usage of `0.0 / 0.0` to obtain NaN instead of std::f32::NaN or std::f64::NaN" } -pub struct Pass; +declare_lint_pass!(ZeroDiv => [ZERO_DIVIDED_BY_ZERO]); -impl LintPass for Pass { - fn get_lints(&self) -> LintArray { - lint_array!(ZERO_DIVIDED_BY_ZERO) - } -} - -impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass { +impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ZeroDiv { fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) { // check for instances of 0.0/0.0 - if_let_chain! {[ - let ExprBinary(ref op, ref left, ref right) = expr.node, - let BinOp_::BiDiv = op.node, + if_chain! { + if let ExprKind::Binary(ref op, ref left, ref right) = expr.kind; + if let BinOpKind::Div = op.node; // TODO - constant_simple does not fold many operations involving floats. // That's probably fine for this lint - it's pretty unlikely that someone would // do something like 0.0/(2.0 - 2.0), but it would be nice to warn on that case too. - let Some(Constant::Float(ref lhs_value, lhs_width)) = constant_simple(cx, left), - let Some(Constant::Float(ref rhs_value, rhs_width)) = constant_simple(cx, right), - Ok(0.0) == lhs_value.parse(), - Ok(0.0) == rhs_value.parse() - ], { - // since we're about to suggest a use of std::f32::NaN or std::f64::NaN, - // match the precision of the literals that are given. - let float_type = match (lhs_width, rhs_width) { - (FloatWidth::F64, _) - | (_, FloatWidth::F64) => "f64", - _ => "f32" - }; - span_help_and_lint(cx, ZERO_DIVIDED_BY_ZERO, expr.span, - "constant division of 0.0 with 0.0 will always result in NaN", - &format!("Consider using `std::{}::NAN` if you would like a constant representing NaN", float_type)); - }} + if let Some(lhs_value) = constant_simple(cx, cx.tables, left); + if let Some(rhs_value) = constant_simple(cx, cx.tables, right); + if Constant::F32(0.0) == lhs_value || Constant::F64(0.0) == lhs_value; + if Constant::F32(0.0) == rhs_value || Constant::F64(0.0) == rhs_value; + then { + // since we're about to suggest a use of std::f32::NaN or std::f64::NaN, + // match the precision of the literals that are given. + let float_type = match (lhs_value, rhs_value) { + (Constant::F64(_), _) + | (_, Constant::F64(_)) => "f64", + _ => "f32" + }; + span_help_and_lint( + cx, + ZERO_DIVIDED_BY_ZERO, + expr.span, + "constant division of 0.0 with 0.0 will always result in NaN", + &format!( + "Consider using `std::{}::NAN` if you would like a constant representing NaN", + float_type, + ), + ); + } + } } }