diff options
Diffstat (limited to 'compiler/rustc_lint/src/unused.rs')
| -rw-r--r-- | compiler/rustc_lint/src/unused.rs | 41 |
1 files changed, 33 insertions, 8 deletions
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index 6041f8075..d5beff4f1 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -816,8 +816,7 @@ trait UnusedDelimLint { let (value, ctx, followed_by_block, left_pos, right_pos, is_kw) = match e.kind { // Do not lint `unused_braces` in `if let` expressions. If(ref cond, ref block, _) - if !matches!(cond.kind, Let(_, _, _)) - || Self::LINT_EXPR_IN_PATTERN_MATCHING_CTX => + if !matches!(cond.kind, Let(..)) || Self::LINT_EXPR_IN_PATTERN_MATCHING_CTX => { let left = e.span.lo() + rustc_span::BytePos(2); let right = block.span.lo(); @@ -826,8 +825,7 @@ trait UnusedDelimLint { // Do not lint `unused_braces` in `while let` expressions. While(ref cond, ref block, ..) - if !matches!(cond.kind, Let(_, _, _)) - || Self::LINT_EXPR_IN_PATTERN_MATCHING_CTX => + if !matches!(cond.kind, Let(..)) || Self::LINT_EXPR_IN_PATTERN_MATCHING_CTX => { let left = e.span.lo() + rustc_span::BytePos(5); let right = block.span.lo(); @@ -955,11 +953,14 @@ declare_lint! { pub struct UnusedParens { with_self_ty_parens: bool, + /// `1 as (i32) < 2` parses to ExprKind::Lt + /// `1 as i32 < 2` parses to i32::<2[missing angle bracket] + parens_in_cast_in_lt: Vec<ast::NodeId>, } impl UnusedParens { pub fn new() -> Self { - Self { with_self_ty_parens: false } + Self { with_self_ty_parens: false, parens_in_cast_in_lt: Vec::new() } } } @@ -1000,7 +1001,7 @@ impl UnusedDelimLint for UnusedParens { self.emit_unused_delims_expr(cx, value, ctx, left_pos, right_pos, is_kw) } } - ast::ExprKind::Let(_, ref expr, _) => { + ast::ExprKind::Let(_, ref expr, _, _) => { self.check_unused_delims_expr( cx, expr, @@ -1055,8 +1056,16 @@ impl UnusedParens { impl EarlyLintPass for UnusedParens { #[inline] fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) { + if let ExprKind::Binary(op, lhs, _rhs) = &e.kind && + (op.node == ast::BinOpKind::Lt || op.node == ast::BinOpKind::Shl) && + let ExprKind::Cast(_expr, ty) = &lhs.kind && + let ast::TyKind::Paren(_) = &ty.kind + { + self.parens_in_cast_in_lt.push(ty.id); + } + match e.kind { - ExprKind::Let(ref pat, _, _) | ExprKind::ForLoop(ref pat, ..) => { + ExprKind::Let(ref pat, _, _, _) | ExprKind::ForLoop(ref pat, ..) => { self.check_unused_parens_pat(cx, pat, false, false, (true, true)); } // We ignore parens in cases like `if (((let Some(0) = Some(1))))` because we already @@ -1101,6 +1110,17 @@ impl EarlyLintPass for UnusedParens { <Self as UnusedDelimLint>::check_expr(self, cx, e) } + fn check_expr_post(&mut self, _cx: &EarlyContext<'_>, e: &ast::Expr) { + if let ExprKind::Binary(op, lhs, _rhs) = &e.kind && + (op.node == ast::BinOpKind::Lt || op.node == ast::BinOpKind::Shl) && + let ExprKind::Cast(_expr, ty) = &lhs.kind && + let ast::TyKind::Paren(_) = &ty.kind + { + let id = self.parens_in_cast_in_lt.pop().expect("check_expr and check_expr_post must balance"); + assert_eq!(id, ty.id, "check_expr, check_ty, and check_expr_post are called, in that order, by the visitor"); + } + } + fn check_pat(&mut self, cx: &EarlyContext<'_>, p: &ast::Pat) { use ast::{Mutability, PatKind::*}; let keep_space = (false, false); @@ -1141,6 +1161,11 @@ impl EarlyLintPass for UnusedParens { } fn check_ty(&mut self, cx: &EarlyContext<'_>, ty: &ast::Ty) { + if let ast::TyKind::Paren(_) = ty.kind && + Some(&ty.id) == self.parens_in_cast_in_lt.last() + { + return; + } match &ty.kind { ast::TyKind::Array(_, len) => { self.check_unused_delims_expr( @@ -1284,7 +1309,7 @@ impl UnusedDelimLint for UnusedBraces { } } } - ast::ExprKind::Let(_, ref expr, _) => { + ast::ExprKind::Let(_, ref expr, _, _) => { self.check_unused_delims_expr( cx, expr, |