Auto merge of #4938 - flip1995:rustup, r=flip1995

[rust.git] / clippy_lints / src / zero_div_zero.rs

diff --git a/clippy_lints/src/zero_div_zero.rs b/clippy_lints/src/zero_div_zero.rs
index 5ff9fb9ffd5dc9cfa729de681d59c9815c4469e1..ec380360e547e1f0297916427edb84fa8d40a71c 100644 (file)
--- 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,
+                    ),
+                );
+            }
+        }
     }
 }