Merge commit '4911ab124c481430672a3833b37075e6435ec34d' into clippyup

[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 f866d76a3819b54b6a5e7e634db33b9ac8c35c18..4b81a27632d8d03df056ef17a1a48b79b7f39bed 100644 (file)
--- a/clippy_lints/src/zero_div_zero.rs
+++ b/clippy_lints/src/zero_div_zero.rs
@@ -1,31 +1,34 @@
 use crate::consts::{constant_simple, Constant};
-use crate::utils::span_help_and_lint;
+use crate::utils::span_lint_and_help;
 use if_chain::if_chain;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_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`.
+    /// **Why is this bad?** It's less readable than `f32::NAN` or `f64::NAN`.
     ///
     /// **Known problems:** None.
     ///
     /// **Example:**
     /// ```rust
-    /// 0.0f32 / 0.0;
+    /// // Bad
+    /// let nan = 0.0f32 / 0.0;
+    ///
+    /// // Good
+    /// let nan = f32::NAN;
     /// ```
     pub ZERO_DIVIDED_BY_ZERO,
     complexity,
-    "usage of `0.0 / 0.0` to obtain NaN instead of std::f32::NaN or std::f64::NaN"
+    "usage of `0.0 / 0.0` to obtain NaN instead of `f32::NAN` or `f64::NAN`"
 }
 
 declare_lint_pass!(ZeroDiv => [ZERO_DIVIDED_BY_ZERO]);
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ZeroDiv {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+impl<'tcx> LateLintPass<'tcx> for ZeroDiv {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         // check for instances of 0.0/0.0
         if_chain! {
             if let ExprKind::Binary(ref op, ref left, ref right) = expr.kind;
@@ -33,25 +36,26 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
             // 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.
-            if let Some(lhs_value) = constant_simple(cx, cx.tables, left);
-            if let Some(rhs_value) = constant_simple(cx, cx.tables, right);
+            if let Some(lhs_value) = constant_simple(cx, cx.typeck_results(), left);
+            if let Some(rhs_value) = constant_simple(cx, cx.typeck_results(), 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,
+                // since we're about to suggest a use of f32::NAN or 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(
+                span_lint_and_help(
                     cx,
                     ZERO_DIVIDED_BY_ZERO,
                     expr.span,
-                    "constant division of 0.0 with 0.0 will always result in NaN",
+                    "constant division of `0.0` with `0.0` will always result in NaN",
+                    None,
                     &format!(
-                        "Consider using `std::{}::NAN` if you would like a constant representing NaN",
+                        "Consider using `{}::NAN` if you would like a constant representing NaN",
                         float_type,
                     ),
                 );