diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/loops/needless_collect.rs')
| -rw-r--r-- | src/tools/clippy/clippy_lints/src/loops/needless_collect.rs | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/src/tools/clippy/clippy_lints/src/loops/needless_collect.rs b/src/tools/clippy/clippy_lints/src/loops/needless_collect.rs index ddaffc751..6e6faa79a 100644 --- a/src/tools/clippy/clippy_lints/src/loops/needless_collect.rs +++ b/src/tools/clippy/clippy_lints/src/loops/needless_collect.rs @@ -1,5 +1,6 @@ use super::NEEDLESS_COLLECT; use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then}; +use clippy_utils::higher; use clippy_utils::source::{snippet, snippet_with_applicability}; use clippy_utils::sugg::Sugg; use clippy_utils::ty::is_type_diagnostic_item; @@ -24,11 +25,11 @@ pub(super) fn check<'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) { } fn check_needless_collect_direct_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) { if_chain! { - if let ExprKind::MethodCall(method, args, _) = expr.kind; - if let ExprKind::MethodCall(chain_method, _, _) = args[0].kind; - if chain_method.ident.name == sym!(collect) && is_trait_method(cx, &args[0], sym::Iterator); + if let ExprKind::MethodCall(method, receiver, args, _) = expr.kind; + if let ExprKind::MethodCall(chain_method, ..) = receiver.kind; + if chain_method.ident.name == sym!(collect) && is_trait_method(cx, receiver, sym::Iterator); then { - let ty = cx.typeck_results().expr_ty(&args[0]); + let ty = cx.typeck_results().expr_ty(receiver); let mut applicability = Applicability::MaybeIncorrect; let is_empty_sugg = "next().is_none()".to_string(); let method_name = method.ident.name.as_str(); @@ -40,7 +41,7 @@ fn check_needless_collect_direct_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateCont "len" => "count()".to_string(), "is_empty" => is_empty_sugg, "contains" => { - let contains_arg = snippet_with_applicability(cx, args[1].span, "??", &mut applicability); + let contains_arg = snippet_with_applicability(cx, args[0].span, "??", &mut applicability); let (arg, pred) = contains_arg .strip_prefix('&') .map_or(("&x", &*contains_arg), |s| ("x", s)); @@ -79,7 +80,7 @@ fn check_needless_collect_indirect_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateCo if let StmtKind::Local(local) = stmt.kind; if let PatKind::Binding(_, id, ..) = local.pat.kind; if let Some(init_expr) = local.init; - if let ExprKind::MethodCall(method_name, &[ref iter_source], ..) = init_expr.kind; + if let ExprKind::MethodCall(method_name, iter_source, [], ..) = init_expr.kind; if method_name.ident.name == sym!(collect) && is_trait_method(cx, init_expr, sym::Iterator); let ty = cx.typeck_results().expr_ty(init_expr); if is_type_diagnostic_item(cx, ty, sym::Vec) || @@ -184,16 +185,25 @@ struct IterFunctionVisitor<'a, 'tcx> { impl<'tcx> Visitor<'tcx> for IterFunctionVisitor<'_, 'tcx> { fn visit_block(&mut self, block: &'tcx Block<'tcx>) { for (expr, hir_id) in block.stmts.iter().filter_map(get_expr_and_hir_id_from_stmt) { + if check_loop_kind(expr).is_some() { + continue; + } self.visit_block_expr(expr, hir_id); } if let Some(expr) = block.expr { - self.visit_block_expr(expr, None); + if let Some(loop_kind) = check_loop_kind(expr) { + if let LoopKind::Conditional(block_expr) = loop_kind { + self.visit_block_expr(block_expr, None); + } + } else { + self.visit_block_expr(expr, None); + } } } fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) { // Check function calls on our collection - if let ExprKind::MethodCall(method_name, [recv, args @ ..], _) = &expr.kind { + if let ExprKind::MethodCall(method_name, recv, [args @ ..], _) = &expr.kind { if method_name.ident.name == sym!(collect) && is_trait_method(self.cx, expr, sym::Iterator) { self.current_mutably_captured_ids = get_captured_ids(self.cx, self.cx.typeck_results().expr_ty(recv)); self.visit_expr(recv); @@ -264,6 +274,28 @@ impl<'tcx> Visitor<'tcx> for IterFunctionVisitor<'_, 'tcx> { } } +enum LoopKind<'tcx> { + Conditional(&'tcx Expr<'tcx>), + Loop, +} + +fn check_loop_kind<'tcx>(expr: &Expr<'tcx>) -> Option<LoopKind<'tcx>> { + if let Some(higher::WhileLet { let_expr, .. }) = higher::WhileLet::hir(expr) { + return Some(LoopKind::Conditional(let_expr)); + } + if let Some(higher::While { condition, .. }) = higher::While::hir(expr) { + return Some(LoopKind::Conditional(condition)); + } + if let Some(higher::ForLoop { arg, .. }) = higher::ForLoop::hir(expr) { + return Some(LoopKind::Conditional(arg)); + } + if let ExprKind::Loop { .. } = expr.kind { + return Some(LoopKind::Loop); + } + + None +} + impl<'tcx> IterFunctionVisitor<'_, 'tcx> { fn visit_block_expr(&mut self, expr: &'tcx Expr<'tcx>, hir_id: Option<HirId>) { self.current_statement_hir_id = hir_id; |