Auto merge of #3946 - rchaser53:issue-3920, r=flip1995

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

diff --git a/clippy_lints/src/precedence.rs b/clippy_lints/src/precedence.rs
index e77a49266ba530e0c403b747a2256eaaa5585343..6819ac74474434e7b899677f38f07d2bcd113944 100644 (file)
--- a/clippy_lints/src/precedence.rs
+++ b/clippy_lints/src/precedence.rs
@@ -1,27 +1,28 @@
-use crate::rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use crate::rustc::{declare_tool_lint, lint_array};
-use crate::syntax::ast::*;
-use crate::syntax::source_map::Spanned;
-use crate::utils::{in_macro, snippet, span_lint_and_sugg};
+use crate::utils::{in_macro, snippet_with_applicability, span_lint_and_sugg};
+use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
+use rustc::{declare_tool_lint, lint_array};
+use rustc_errors::Applicability;
+use syntax::ast::*;
+use syntax::source_map::Spanned;
 
-/// **What it does:** Checks for operations where precedence may be unclear
-/// and suggests to add parentheses. Currently it catches the following:
-/// * mixed usage of arithmetic and bit shifting/combining operators without
-/// parentheses
-/// * a "negative" numeric literal (which is really a unary `-` followed by a
-/// numeric literal)
-///   followed by a method call
-///
-/// **Why is this bad?** Not everyone knows the precedence of those operators by
-/// heart, so expressions like these may trip others trying to reason about the
-/// code.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// * `1 << 2 + 3` equals 32, while `(1 << 2) + 3` equals 7
-/// * `-1i32.abs()` equals -1, while `(-1i32).abs()` equals 1
 declare_clippy_lint! {
+    /// **What it does:** Checks for operations where precedence may be unclear
+    /// and suggests to add parentheses. Currently it catches the following:
+    /// * mixed usage of arithmetic and bit shifting/combining operators without
+    /// parentheses
+    /// * a "negative" numeric literal (which is really a unary `-` followed by a
+    /// numeric literal)
+    ///   followed by a method call
+    ///
+    /// **Why is this bad?** Not everyone knows the precedence of those operators by
+    /// heart, so expressions like these may trip others trying to reason about the
+    /// code.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    /// * `1 << 2 + 3` equals 32, while `(1 << 2) + 3` equals 7
+    /// * `-1i32.abs()` equals -1, while `(-1i32).abs()` equals 1
     pub PRECEDENCE,
     complexity,
     "operations where precedence may be unclear"
@@ -34,6 +35,10 @@ impl LintPass for Precedence {
     fn get_lints(&self) -> LintArray {
         lint_array!(PRECEDENCE)
     }
+
+    fn name(&self) -> &'static str {
+        "Precedence"
+    }
 }
 
 impl EarlyLintPass for Precedence {
@@ -43,7 +48,7 @@ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
         }
 
         if let ExprKind::Binary(Spanned { node: op, .. }, ref left, ref right) = expr.node {
-            let span_sugg = |expr: &Expr, sugg| {
+            let span_sugg = |expr: &Expr, sugg, appl| {
                 span_lint_and_sugg(
                     cx,
                     PRECEDENCE,
@@ -51,39 +56,41 @@ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
                     "operator precedence can trip the unwary",
                     "consider parenthesizing your expression",
                     sugg,
+                    appl,
                 );
             };
 
             if !is_bit_op(op) {
                 return;
             }
+            let mut applicability = Applicability::MachineApplicable;
             match (is_arith_expr(left), is_arith_expr(right)) {
                 (true, true) => {
                     let sugg = format!(
                         "({}) {} ({})",
-                        snippet(cx, left.span, ".."),
+                        snippet_with_applicability(cx, left.span, "..", &mut applicability),
                         op.to_string(),
-                        snippet(cx, right.span, "..")
+                        snippet_with_applicability(cx, right.span, "..", &mut applicability)
                     );
-                    span_sugg(expr, sugg);
+                    span_sugg(expr, sugg, applicability);
                 },
                 (true, false) => {
                     let sugg = format!(
                         "({}) {} {}",
-                        snippet(cx, left.span, ".."),
+                        snippet_with_applicability(cx, left.span, "..", &mut applicability),
                         op.to_string(),
-                        snippet(cx, right.span, "..")
+                        snippet_with_applicability(cx, right.span, "..", &mut applicability)
                     );
-                    span_sugg(expr, sugg);
+                    span_sugg(expr, sugg, applicability);
                 },
                 (false, true) => {
                     let sugg = format!(
                         "{} {} ({})",
-                        snippet(cx, left.span, ".."),
+                        snippet_with_applicability(cx, left.span, "..", &mut applicability),
                         op.to_string(),
-                        snippet(cx, right.span, "..")
+                        snippet_with_applicability(cx, right.span, "..", &mut applicability)
                     );
-                    span_sugg(expr, sugg);
+                    span_sugg(expr, sugg, applicability);
                 },
                 (false, false) => (),
             }
@@ -95,13 +102,18 @@ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
                     if let ExprKind::Lit(ref lit) = slf.node {
                         match lit.node {
                             LitKind::Int(..) | LitKind::Float(..) | LitKind::FloatUnsuffixed(..) => {
+                                let mut applicability = Applicability::MachineApplicable;
                                 span_lint_and_sugg(
                                     cx,
                                     PRECEDENCE,
                                     expr.span,
                                     "unary minus has lower precedence than method call",
                                     "consider adding parentheses to clarify your intent",
-                                    format!("-({})", snippet(cx, rhs.span, "..")),
+                                    format!(
+                                        "-({})",
+                                        snippet_with_applicability(cx, rhs.span, "..", &mut applicability)
+                                    ),
+                                    applicability,
                                 );
                             },
                             _ => (),
@@ -121,7 +133,7 @@ fn is_arith_expr(expr: &Expr) -> bool {
 }
 
 fn is_bit_op(op: BinOpKind) -> bool {
-    use crate::syntax::ast::BinOpKind::*;
+    use syntax::ast::BinOpKind::*;
     match op {
         BitXor | BitAnd | BitOr | Shl | Shr => true,
         _ => false,
@@ -129,7 +141,7 @@ fn is_bit_op(op: BinOpKind) -> bool {
 }
 
 fn is_arith_op(op: BinOpKind) -> bool {
-    use crate::syntax::ast::BinOpKind::*;
+    use syntax::ast::BinOpKind::*;
     match op {
         Add | Sub | Mul | Div | Rem => true,
         _ => false,