diff options
Diffstat (limited to 'compiler/rustc_lint/src/unused.rs')
| -rw-r--r-- | compiler/rustc_lint/src/unused.rs | 95 |
1 files changed, 51 insertions, 44 deletions
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index 28cc63198..8f75fa11d 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -256,7 +256,7 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { } ty::Adt(def, _) => is_def_must_use(cx, def.did(), span), ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => { - elaborate(cx.tcx, cx.tcx.explicit_item_bounds(def).iter().cloned()) + elaborate(cx.tcx, cx.tcx.explicit_item_bounds(def).subst_identity_iter_copied()) // We only care about self bounds for the impl-trait .filter_only_self() .find_map(|(pred, _span)| { @@ -571,36 +571,50 @@ trait UnusedDelimLint { } } - // Prevent false-positives in cases like `fn x() -> u8 { ({ 0 } + 1) }` - let lhs_needs_parens = { + // Check if LHS needs parens to prevent false-positives in cases like `fn x() -> u8 { ({ 0 } + 1) }`. + { let mut innermost = inner; loop { innermost = match &innermost.kind { - ExprKind::Binary(_, lhs, _rhs) => lhs, + ExprKind::Binary(_op, lhs, _rhs) => lhs, ExprKind::Call(fn_, _params) => fn_, ExprKind::Cast(expr, _ty) => expr, ExprKind::Type(expr, _ty) => expr, ExprKind::Index(base, _subscript) => base, - _ => break false, + _ => break, }; if !classify::expr_requires_semi_to_be_stmt(innermost) { - break true; + return true; } } - }; + } - lhs_needs_parens - || (followed_by_block - && match &inner.kind { - ExprKind::Ret(_) - | ExprKind::Break(..) - | ExprKind::Yield(..) - | ExprKind::Yeet(..) => true, - ExprKind::Range(_lhs, Some(rhs), _limits) => { - matches!(rhs.kind, ExprKind::Block(..)) - } - _ => parser::contains_exterior_struct_lit(&inner), - }) + // Check if RHS needs parens to prevent false-positives in cases like `if (() == return) {}`. + if !followed_by_block { + return false; + } + let mut innermost = inner; + loop { + innermost = match &innermost.kind { + ExprKind::Unary(_op, expr) => expr, + ExprKind::Binary(_op, _lhs, rhs) => rhs, + ExprKind::AssignOp(_op, _lhs, rhs) => rhs, + ExprKind::Assign(_lhs, rhs, _span) => rhs, + + ExprKind::Ret(_) | ExprKind::Yield(..) | ExprKind::Yeet(..) => return true, + + ExprKind::Break(_label, None) => return false, + ExprKind::Break(_label, Some(break_expr)) => { + return matches!(break_expr.kind, ExprKind::Block(..)); + } + + ExprKind::Range(_lhs, Some(rhs), _limits) => { + return matches!(rhs.kind, ExprKind::Block(..)); + } + + _ => return parser::contains_exterior_struct_lit(&inner), + } + } } fn emit_unused_delims_expr( @@ -638,26 +652,20 @@ trait UnusedDelimLint { return; } let spans = match value.kind { - ast::ExprKind::Block(ref block, None) if block.stmts.len() == 1 => { - if let Some(span) = block.stmts[0].span.find_ancestor_inside(value.span) { - Some((value.span.with_hi(span.lo()), value.span.with_lo(span.hi()))) - } else { - None - } - } + ast::ExprKind::Block(ref block, None) if block.stmts.len() == 1 => block.stmts[0] + .span + .find_ancestor_inside(value.span) + .map(|span| (value.span.with_hi(span.lo()), value.span.with_lo(span.hi()))), ast::ExprKind::Paren(ref expr) => { - let expr_span = expr.span.find_ancestor_inside(value.span); - if let Some(expr_span) = expr_span { - Some((value.span.with_hi(expr_span.lo()), value.span.with_lo(expr_span.hi()))) - } else { - None - } + expr.span.find_ancestor_inside(value.span).map(|expr_span| { + (value.span.with_hi(expr_span.lo()), value.span.with_lo(expr_span.hi())) + }) } _ => return, }; let keep_space = ( - left_pos.map_or(false, |s| s >= value.span.lo()), - right_pos.map_or(false, |s| s <= value.span.hi()), + left_pos.is_some_and(|s| s >= value.span.lo()), + right_pos.is_some_and(|s| s <= value.span.hi()), ); self.emit_unused_delims(cx, value.span, spans, ctx.into(), keep_space); } @@ -930,11 +938,10 @@ impl UnusedParens { // Otherwise proceed with linting. _ => {} } - let spans = if let Some(inner) = inner.span.find_ancestor_inside(value.span) { - Some((value.span.with_hi(inner.lo()), value.span.with_lo(inner.hi()))) - } else { - None - }; + let spans = inner + .span + .find_ancestor_inside(value.span) + .map(|inner| (value.span.with_hi(inner.lo()), value.span.with_lo(inner.hi()))); self.emit_unused_delims(cx, value.span, spans, "pattern", keep_space); } } @@ -1045,11 +1052,11 @@ impl EarlyLintPass for UnusedParens { if self.with_self_ty_parens && b.generic_params.len() > 0 => {} ast::TyKind::ImplTrait(_, bounds) if bounds.len() > 1 => {} _ => { - let spans = if let Some(r) = r.span.find_ancestor_inside(ty.span) { - Some((ty.span.with_hi(r.lo()), ty.span.with_lo(r.hi()))) - } else { - None - }; + let spans = r + .span + .find_ancestor_inside(ty.span) + .map(|r| (ty.span.with_hi(r.lo()), ty.span.with_lo(r.hi()))); + self.emit_unused_delims(cx, ty.span, spans, "type", (false, false)); } } |