-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 = ¶ms[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 = ¶ms[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);
}
}
},