-use crate::utils::span_lint;
+use clippy_utils::diagnostics::span_lint;
use rustc_ast::ast::{Expr, ExprKind};
use rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
- /// **What it does:** Checks for unnecessary double parentheses.
+ /// ### What it does
+ /// Checks for unnecessary double parentheses.
///
- /// **Why is this bad?** This makes code harder to read and might indicate a
+ /// ### Why is this bad?
+ /// This makes code harder to read and might indicate a
/// mistake.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
+ /// fn simple_double_parens() -> i32 {
+ /// ((0))
+ /// }
+ ///
/// # fn foo(bar: usize) {}
- /// ((0));
/// foo((0));
- /// ((1, 2));
/// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// fn simple_no_parens() -> i32 {
+ /// 0
+ /// }
+ ///
+ /// # fn foo(bar: usize) {}
+ /// foo(0);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
pub DOUBLE_PARENS,
complexity,
"Warn on unnecessary double parentheses"
return;
}
+ 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);
},
_ => {},
},
if params.len() == 1 {
let param = ¶ms[0];
if let ExprKind::Paren(_) = param.kind {
- span_lint(
- cx,
- DOUBLE_PARENS,
- param.span,
- "Consider removing unnecessary double parentheses",
- );
+ span_lint(cx, DOUBLE_PARENS, param.span, msg);
}
}
},
- ExprKind::MethodCall(_, ref params) => {
- if params.len() == 2 {
- let param = ¶ms[1];
- if let ExprKind::Paren(_) = param.kind {
- span_lint(
- cx,
- DOUBLE_PARENS,
- param.span,
- "Consider removing unnecessary double parentheses",
- );
+ ExprKind::MethodCall(ref call) => {
+ if let [ref arg] = call.args[..] {
+ if let ExprKind::Paren(_) = arg.kind {
+ span_lint(cx, DOUBLE_PARENS, arg.span, msg);
}
}
},