| use clippy_utils::diagnostics::span_lint_and_sugg; |
| use clippy_utils::source::{indent_of, reindent_multiline, snippet_opt}; |
| use clippy_utils::ty::is_type_diagnostic_item; |
| use clippy_utils::{is_res_lang_ctor, path_res, path_to_local_id}; |
| use if_chain::if_chain; |
| use rustc_errors::Applicability; |
| use rustc_hir::LangItem::{ResultErr, ResultOk}; |
| use rustc_hir::{Expr, ExprKind, PatKind}; |
| use rustc_lint::LateContext; |
| use rustc_span::symbol::sym; |
| |
| use super::MANUAL_OK_OR; |
| |
| pub(super) fn check<'tcx>( |
| cx: &LateContext<'tcx>, |
| expr: &'tcx Expr<'tcx>, |
| recv: &'tcx Expr<'_>, |
| or_expr: &'tcx Expr<'_>, |
| map_expr: &'tcx Expr<'_>, |
| ) { |
| if_chain! { |
| if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id); |
| if let Some(impl_id) = cx.tcx.impl_of_method(method_id); |
| if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).instantiate_identity(), sym::Option); |
| if let ExprKind::Call(err_path, [err_arg]) = or_expr.kind; |
| if is_res_lang_ctor(cx, path_res(cx, err_path), ResultErr); |
| if is_ok_wrapping(cx, map_expr); |
| if let Some(recv_snippet) = snippet_opt(cx, recv.span); |
| if let Some(err_arg_snippet) = snippet_opt(cx, err_arg.span); |
| if let Some(indent) = indent_of(cx, expr.span); |
| then { |
| let reindented_err_arg_snippet = reindent_multiline(err_arg_snippet.into(), true, Some(indent + 4)); |
| span_lint_and_sugg( |
| cx, |
| MANUAL_OK_OR, |
| expr.span, |
| "this pattern reimplements `Option::ok_or`", |
| "replace with", |
| format!( |
| "{recv_snippet}.ok_or({reindented_err_arg_snippet})" |
| ), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| } |
| |
| fn is_ok_wrapping(cx: &LateContext<'_>, map_expr: &Expr<'_>) -> bool { |
| match map_expr.kind { |
| ExprKind::Path(ref qpath) if is_res_lang_ctor(cx, cx.qpath_res(qpath, map_expr.hir_id), ResultOk) => true, |
| ExprKind::Closure(closure) => { |
| let body = cx.tcx.hir().body(closure.body); |
| if let PatKind::Binding(_, param_id, ..) = body.params[0].pat.kind |
| && let ExprKind::Call(callee, [ok_arg]) = body.value.kind |
| && is_res_lang_ctor(cx, path_res(cx, callee), ResultOk) |
| { |
| path_to_local_id(ok_arg, param_id) |
| } else { |
| false |
| } |
| }, |
| _ => false, |
| } |
| } |