hir: Preserve used syntax in `TyKind::TraitObject`

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

diff --git a/clippy_lints/src/double_parens.rs b/clippy_lints/src/double_parens.rs
index 38381b069f073294ca673c15d665701f369222b1..abbcaf43f4151adcdfc44c0954d6e797531667f4 100644 (file)
--- a/clippy_lints/src/double_parens.rs
+++ b/clippy_lints/src/double_parens.rs
@@ -1,77 +1,72 @@
-use crate::utils::{in_macro, span_lint};
-use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use syntax::ast::*;
+use crate::utils::span_lint;
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
 
-/// **What it does:** Checks for unnecessary double parentheses.
-///
-/// **Why is this bad?** This makes code harder to read and might indicate a
-/// mistake.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// ((0))
-/// foo((0))
-/// ((1, 2))
-/// ```
 declare_clippy_lint! {
+    /// **What it does:** Checks for unnecessary double parentheses.
+    ///
+    /// **Why is this bad?** This makes code harder to read and might indicate a
+    /// mistake.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    /// ```rust
+    /// // Bad
+    /// fn simple_double_parens() -> i32 {
+    ///     ((0))
+    /// }
+    ///
+    /// // Good
+    /// fn simple_no_parens() -> i32 {
+    ///     0
+    /// }
+    ///
+    /// // or
+    ///
+    /// # fn foo(bar: usize) {}
+    /// // Bad
+    /// foo((0));
+    ///
+    /// // Good
+    /// foo(0);
+    /// ```
     pub DOUBLE_PARENS,
     complexity,
     "Warn on unnecessary double parentheses"
 }
 
-#[derive(Copy, Clone)]
-pub struct DoubleParens;
-
-impl LintPass for DoubleParens {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(DOUBLE_PARENS)
-    }
-}
+declare_lint_pass!(DoubleParens => [DOUBLE_PARENS]);
 
 impl EarlyLintPass for DoubleParens {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
-        if in_macro(expr.span) {
+        if expr.span.from_expansion() {
             return;
         }
 
-        match expr.node {
-            ExprKind::Paren(ref in_paren) => match in_paren.node {
+        let msg: &str = "consider removing unnecessary double parentheses";
+
+        match expr.kind {
+            ExprKind::Paren(ref in_paren) => match in_paren.kind {
                 ExprKind::Paren(_) | ExprKind::Tup(_) => {
-                    span_lint(
-                        cx,
-                        DOUBLE_PARENS,
-                        expr.span,
-                        "Consider removing unnecessary double parentheses",
-                    );
+                    span_lint(cx, DOUBLE_PARENS, expr.span, &msg);
                 },
                 _ => {},
             },
             ExprKind::Call(_, ref params) => {
                 if params.len() == 1 {
                     let param = &params[0];
-                    if let ExprKind::Paren(_) = param.node {
-                        span_lint(
-                            cx,
-                            DOUBLE_PARENS,
-                            param.span,
-                            "Consider removing unnecessary double parentheses",
-                        );
+                    if let ExprKind::Paren(_) = param.kind {
+                        span_lint(cx, DOUBLE_PARENS, param.span, &msg);
                     }
                 }
             },
-            ExprKind::MethodCall(_, ref params) => {
+            ExprKind::MethodCall(_, ref params, _) => {
                 if params.len() == 2 {
                     let param = &params[1];
-                    if let ExprKind::Paren(_) = param.node {
-                        span_lint(
-                            cx,
-                            DOUBLE_PARENS,
-                            param.span,
-                            "Consider removing unnecessary double parentheses",
-                        );
+                    if let ExprKind::Paren(_) = param.kind {
+                        span_lint(cx, DOUBLE_PARENS, param.span, &msg);
                     }
                 }
             },