2019-05-12 03:40:05 +00:00
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use crate::utils::{in_macro_or_desugar, span_lint};
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2018-12-29 15:04:45 +00:00
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use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
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2019-04-08 20:43:55 +00:00
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use rustc::{declare_lint_pass, declare_tool_lint};
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2018-12-29 15:04:45 +00:00
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use syntax::ast::*;
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2018-09-22 15:20:34 +00:00
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for unnecessary double parentheses.
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///
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/// **Why is this bad?** This makes code harder to read and might indicate a
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/// mistake.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// ((0))
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/// foo((0))
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/// ((1, 2))
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/// ```
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2018-03-28 13:24:26 +00:00
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pub DOUBLE_PARENS,
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complexity,
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2016-12-28 18:54:23 +00:00
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"Warn on unnecessary double parentheses"
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}
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2019-04-08 20:43:55 +00:00
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declare_lint_pass!(DoubleParens => [DOUBLE_PARENS]);
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2016-12-28 18:54:23 +00:00
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impl EarlyLintPass for DoubleParens {
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2018-07-23 11:01:12 +00:00
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fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
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2019-05-12 03:40:05 +00:00
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if in_macro_or_desugar(expr.span) {
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2018-09-22 15:20:34 +00:00
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return;
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}
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2016-12-28 20:03:49 +00:00
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match expr.node {
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2017-09-05 09:33:04 +00:00
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ExprKind::Paren(ref in_paren) => match in_paren.node {
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ExprKind::Paren(_) | ExprKind::Tup(_) => {
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2018-11-27 20:14:15 +00:00
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span_lint(
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cx,
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DOUBLE_PARENS,
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expr.span,
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"Consider removing unnecessary double parentheses",
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);
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2017-09-05 09:33:04 +00:00
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},
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_ => {},
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2016-12-28 20:03:49 +00:00
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},
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2018-11-27 20:14:15 +00:00
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ExprKind::Call(_, ref params) => {
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if params.len() == 1 {
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let param = ¶ms[0];
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if let ExprKind::Paren(_) = param.node {
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span_lint(
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cx,
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DOUBLE_PARENS,
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param.span,
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"Consider removing unnecessary double parentheses",
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);
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}
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2016-12-28 20:03:49 +00:00
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}
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},
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2018-11-27 20:14:15 +00:00
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ExprKind::MethodCall(_, ref params) => {
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if params.len() == 2 {
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let param = ¶ms[1];
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if let ExprKind::Paren(_) = param.node {
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span_lint(
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cx,
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DOUBLE_PARENS,
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param.span,
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"Consider removing unnecessary double parentheses",
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);
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}
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2016-12-28 20:03:49 +00:00
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}
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},
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_ => {},
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}
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2016-12-28 18:54:23 +00:00
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}
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}
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