X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fmap_unit_fn.rs;h=57cd907e77e8da975a56773a5e357e0125de3394;hb=ebf88c9734246a790305f6faaba0bf8e3f150dff;hp=316a71c500512d287b449ee4dfe4ecdde637093f;hpb=245b006a2e9453307443356d511e9e89967cfef9;p=rust.git diff --git a/clippy_lints/src/map_unit_fn.rs b/clippy_lints/src/map_unit_fn.rs index 316a71c5005..57cd907e77e 100644 --- a/clippy_lints/src/map_unit_fn.rs +++ b/clippy_lints/src/map_unit_fn.rs @@ -1,4 +1,7 @@ -use crate::utils::{is_type_diagnostic_item, iter_input_pats, method_chain_args, snippet, span_lint_and_then}; +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::source::snippet; +use clippy_utils::ty::is_type_diagnostic_item; +use clippy_utils::{iter_input_pats, method_chain_args}; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir as hir; @@ -6,10 +9,11 @@ use rustc_middle::ty::{self, Ty}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::source_map::Span; +use rustc_span::sym; declare_clippy_lint! { /// **What it does:** Checks for usage of `option.map(f)` where f is a function - /// or closure that returns the unit type. + /// or closure that returns the unit type `()`. /// /// **Why is this bad?** Readability, this can be written more clearly with /// an if let statement @@ -51,7 +55,7 @@ declare_clippy_lint! { /// **What it does:** Checks for usage of `result.map(f)` where f is a function - /// or closure that returns the unit type. + /// or closure that returns the unit type `()`. /// /// **Why is this bad?** Readability, this can be written more clearly with /// an if let statement @@ -93,7 +97,7 @@ declare_lint_pass!(MapUnit => [OPTION_MAP_UNIT_FN, RESULT_MAP_UNIT_FN]); fn is_unit_type(ty: Ty<'_>) -> bool { - match ty.kind { + match ty.kind() { ty::Tuple(slice) => slice.is_empty(), ty::Never => true, _ => false, @@ -101,9 +105,9 @@ fn is_unit_type(ty: Ty<'_>) -> bool { } fn is_unit_function(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool { - let ty = cx.tables().expr_ty(expr); + let ty = cx.typeck_results().expr_ty(expr); - if let ty::FnDef(id, _) = ty.kind { + if let ty::FnDef(id, _) = *ty.kind() { if let Some(fn_type) = cx.tcx.fn_sig(id).no_bound_vars() { return is_unit_type(fn_type.output()); } @@ -112,7 +116,7 @@ fn is_unit_function(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool { } fn is_unit_expression(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool { - is_unit_type(cx.tables().expr_ty(expr)) + is_unit_type(cx.typeck_results().expr_ty(expr)) } /// The expression inside a closure may or may not have surrounding braces and @@ -129,8 +133,8 @@ fn reduce_unit_expression<'a>(cx: &LateContext<'_>, expr: &'a hir::Expr<'_>) -> // Calls can't be reduced any more Some(expr.span) }, - hir::ExprKind::Block(ref block, _) => { - match (&block.stmts[..], block.expr.as_ref()) { + hir::ExprKind::Block(block, _) => { + match (block.stmts, block.expr.as_ref()) { (&[], Some(inner_expr)) => { // If block only contains an expression, // reduce `{ X }` to `X` @@ -140,8 +144,8 @@ fn reduce_unit_expression<'a>(cx: &LateContext<'_>, expr: &'a hir::Expr<'_>) -> // If block only contains statements, // reduce `{ X; }` to `X` or `X;` match inner_stmt.kind { - hir::StmtKind::Local(ref local) => Some(local.span), - hir::StmtKind::Expr(ref e) => Some(e.span), + hir::StmtKind::Local(local) => Some(local.span), + hir::StmtKind::Expr(e) => Some(e.span), hir::StmtKind::Semi(..) => Some(inner_stmt.span), hir::StmtKind::Item(..) => None, } @@ -164,17 +168,15 @@ fn unit_closure<'tcx>( cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, ) -> Option<(&'tcx hir::Param<'tcx>, &'tcx hir::Expr<'tcx>)> { - if let hir::ExprKind::Closure(_, ref decl, inner_expr_id, _, _) = expr.kind { + if_chain! { + if let hir::ExprKind::Closure(_, decl, inner_expr_id, _, _) = expr.kind; let body = cx.tcx.hir().body(inner_expr_id); let body_expr = &body.value; - - if_chain! { - if decl.inputs.len() == 1; - if is_unit_expression(cx, body_expr); - if let Some(binding) = iter_input_pats(&decl, body).next(); - then { - return Some((binding, body_expr)); - } + if decl.inputs.len() == 1; + if is_unit_expression(cx, body_expr); + if let Some(binding) = iter_input_pats(decl, body).next(); + then { + return Some((binding, body_expr)); } } None @@ -197,7 +199,7 @@ fn let_binding_name(cx: &LateContext<'_>, var_arg: &hir::Expr<'_>) -> String { #[must_use] fn suggestion_msg(function_type: &str, map_type: &str) -> String { format!( - "called `map(f)` on an `{0}` value where `f` is a {1} that returns the unit type", + "called `map(f)` on an `{0}` value where `f` is a {1} that returns the unit type `()`", map_type, function_type ) } @@ -205,13 +207,14 @@ fn suggestion_msg(function_type: &str, map_type: &str) -> String { fn lint_map_unit_fn(cx: &LateContext<'_>, stmt: &hir::Stmt<'_>, expr: &hir::Expr<'_>, map_args: &[hir::Expr<'_>]) { let var_arg = &map_args[0]; - let (map_type, variant, lint) = if is_type_diagnostic_item(cx, cx.tables().expr_ty(var_arg), sym!(option_type)) { - ("Option", "Some", OPTION_MAP_UNIT_FN) - } else if is_type_diagnostic_item(cx, cx.tables().expr_ty(var_arg), sym!(result_type)) { - ("Result", "Ok", RESULT_MAP_UNIT_FN) - } else { - return; - }; + let (map_type, variant, lint) = + if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(var_arg), sym::option_type) { + ("Option", "Some", OPTION_MAP_UNIT_FN) + } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(var_arg), sym::result_type) { + ("Result", "Ok", RESULT_MAP_UNIT_FN) + } else { + return; + }; let fn_arg = &map_args[1]; if is_unit_function(cx, fn_arg) { @@ -264,7 +267,7 @@ fn check_stmt(&mut self, cx: &LateContext<'_>, stmt: &hir::Stmt<'_>) { return; } - if let hir::StmtKind::Semi(ref expr) = stmt.kind { + if let hir::StmtKind::Semi(expr) = stmt.kind { if let Some(arglists) = method_chain_args(expr, &["map"]) { lint_map_unit_fn(cx, stmt, expr, arglists[0]); }