| use super::FILTER_MAP_BOOL_THEN; |
| use clippy_utils::diagnostics::span_lint_and_sugg; |
| use clippy_utils::paths::BOOL_THEN; |
| use clippy_utils::source::snippet_opt; |
| use clippy_utils::ty::is_copy; |
| use clippy_utils::{is_from_proc_macro, is_trait_method, match_def_path, peel_blocks}; |
| use rustc_errors::Applicability; |
| use rustc_hir::{Expr, ExprKind}; |
| use rustc_lint::{LateContext, LintContext}; |
| use rustc_middle::lint::in_external_macro; |
| use rustc_middle::ty::Binder; |
| use rustc_span::{sym, Span}; |
| |
| pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, arg: &Expr<'_>, call_span: Span) { |
| if !in_external_macro(cx.sess(), expr.span) |
| && is_trait_method(cx, expr, sym::Iterator) |
| && let ExprKind::Closure(closure) = arg.kind |
| && let body = cx.tcx.hir().body(closure.body) |
| && let value = peel_blocks(body.value) |
| // Indexing should be fine as `filter_map` always has 1 input, we unfortunately need both |
| // `inputs` and `params` here as we need both the type and the span |
| && let param_ty = closure.fn_decl.inputs[0] |
| && let param = body.params[0] |
| // Issue #11309 |
| && let param_ty = cx.tcx.liberate_late_bound_regions( |
| closure.def_id.to_def_id(), |
| Binder::bind_with_vars( |
| cx.typeck_results().node_type(param_ty.hir_id), |
| cx.tcx.late_bound_vars(cx.tcx.hir().local_def_id_to_hir_id(closure.def_id)), |
| ), |
| ) |
| && is_copy(cx, param_ty) |
| && let ExprKind::MethodCall(_, recv, [then_arg], _) = value.kind |
| && let ExprKind::Closure(then_closure) = then_arg.kind |
| && let then_body = peel_blocks(cx.tcx.hir().body(then_closure.body).value) |
| && let Some(def_id) = cx.typeck_results().type_dependent_def_id(value.hir_id) |
| && match_def_path(cx, def_id, &BOOL_THEN) |
| && !is_from_proc_macro(cx, expr) |
| && let Some(param_snippet) = snippet_opt(cx, param.span) |
| && let Some(filter) = snippet_opt(cx, recv.span) |
| && let Some(map) = snippet_opt(cx, then_body.span) |
| { |
| span_lint_and_sugg( |
| cx, |
| FILTER_MAP_BOOL_THEN, |
| call_span, |
| "usage of `bool::then` in `filter_map`", |
| "use `filter` then `map` instead", |
| format!("filter(|&{param_snippet}| {filter}).map(|{param_snippet}| {map})"), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |