diff options
| -rw-r--r-- | clippy_lints/src/methods/mod.rs | 114 | ||||
| -rw-r--r-- | clippy_lints/src/methods/option_as_ref_deref.rs | 122 |
2 files changed, 125 insertions, 111 deletions
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 34def45a8dd..c6b6ef34bc4 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -10,6 +10,7 @@ mod inspect_for_each; mod iter_count; mod manual_saturating_arithmetic; mod ok_expect; +mod option_as_ref_deref; mod option_map_unwrap_or; mod skip_while_next; mod unnecessary_filter_map; @@ -1725,10 +1726,10 @@ impl<'tcx> LateLintPass<'tcx> for Methods { }, ["is_file", ..] => lint_filetype_is_file(cx, expr, arg_lists[0]), ["map", "as_ref"] => { - lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], false, self.msrv.as_ref()) + option_as_ref_deref::check(cx, expr, arg_lists[1], arg_lists[0], false, self.msrv.as_ref()) }, ["map", "as_mut"] => { - lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], true, self.msrv.as_ref()) + option_as_ref_deref::check(cx, expr, arg_lists[1], arg_lists[0], true, self.msrv.as_ref()) }, ["unwrap_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"), ["get_or_insert_with", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "get_or_insert"), @@ -3584,115 +3585,6 @@ fn lint_suspicious_map(cx: &LateContext<'_>, expr: &hir::Expr<'_>) { ); } -const OPTION_AS_REF_DEREF_MSRV: RustcVersion = RustcVersion::new(1, 40, 0); - -/// lint use of `_.as_ref().map(Deref::deref)` for `Option`s -fn lint_option_as_ref_deref<'tcx>( - cx: &LateContext<'tcx>, - expr: &hir::Expr<'_>, - as_ref_args: &[hir::Expr<'_>], - map_args: &[hir::Expr<'_>], - is_mut: bool, - msrv: Option<&RustcVersion>, -) { - if !meets_msrv(msrv, &OPTION_AS_REF_DEREF_MSRV) { - return; - } - - let same_mutability = |m| (is_mut && m == &hir::Mutability::Mut) || (!is_mut && m == &hir::Mutability::Not); - - let option_ty = cx.typeck_results().expr_ty(&as_ref_args[0]); - if !is_type_diagnostic_item(cx, option_ty, sym::option_type) { - return; - } - - let deref_aliases: [&[&str]; 9] = [ - &paths::DEREF_TRAIT_METHOD, - &paths::DEREF_MUT_TRAIT_METHOD, - &paths::CSTRING_AS_C_STR, - &paths::OS_STRING_AS_OS_STR, - &paths::PATH_BUF_AS_PATH, - &paths::STRING_AS_STR, - &paths::STRING_AS_MUT_STR, - &paths::VEC_AS_SLICE, - &paths::VEC_AS_MUT_SLICE, - ]; - - let is_deref = match map_args[1].kind { - hir::ExprKind::Path(ref expr_qpath) => cx - .qpath_res(expr_qpath, map_args[1].hir_id) - .opt_def_id() - .map_or(false, |fun_def_id| { - deref_aliases.iter().any(|path| match_def_path(cx, fun_def_id, path)) - }), - hir::ExprKind::Closure(_, _, body_id, _, _) => { - let closure_body = cx.tcx.hir().body(body_id); - let closure_expr = remove_blocks(&closure_body.value); - - match &closure_expr.kind { - hir::ExprKind::MethodCall(_, _, args, _) => { - if_chain! { - if args.len() == 1; - if path_to_local_id(&args[0], closure_body.params[0].pat.hir_id); - let adj = cx - .typeck_results() - .expr_adjustments(&args[0]) - .iter() - .map(|x| &x.kind) - .collect::<Box<[_]>>(); - if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj; - then { - let method_did = cx.typeck_results().type_dependent_def_id(closure_expr.hir_id).unwrap(); - deref_aliases.iter().any(|path| match_def_path(cx, method_did, path)) - } else { - false - } - } - }, - hir::ExprKind::AddrOf(hir::BorrowKind::Ref, m, ref inner) if same_mutability(m) => { - if_chain! { - if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner1) = inner.kind; - if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner2) = inner1.kind; - then { - path_to_local_id(inner2, closure_body.params[0].pat.hir_id) - } else { - false - } - } - }, - _ => false, - } - }, - _ => false, - }; - - if is_deref { - let current_method = if is_mut { - format!(".as_mut().map({})", snippet(cx, map_args[1].span, "..")) - } else { - format!(".as_ref().map({})", snippet(cx, map_args[1].span, "..")) - }; - let method_hint = if is_mut { "as_deref_mut" } else { "as_deref" }; - let hint = format!("{}.{}()", snippet(cx, as_ref_args[0].span, ".."), method_hint); - let suggestion = format!("try using {} instead", method_hint); - - let msg = format!( - "called `{0}` on an Option value. This can be done more directly \ - by calling `{1}` instead", - current_method, hint - ); - span_lint_and_sugg( - cx, - OPTION_AS_REF_DEREF, - expr.span, - &msg, - &suggestion, - hint, - Applicability::MachineApplicable, - ); - } -} - fn lint_map_collect( cx: &LateContext<'_>, expr: &hir::Expr<'_>, diff --git a/clippy_lints/src/methods/option_as_ref_deref.rs b/clippy_lints/src/methods/option_as_ref_deref.rs new file mode 100644 index 00000000000..89067dbfe0e --- /dev/null +++ b/clippy_lints/src/methods/option_as_ref_deref.rs @@ -0,0 +1,122 @@ +use crate::utils::{ + is_type_diagnostic_item, match_def_path, meets_msrv, path_to_local_id, paths, remove_blocks, snippet, + span_lint_and_sugg, +}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_semver::RustcVersion; +use rustc_span::sym; + +use super::OPTION_AS_REF_DEREF; + +const OPTION_AS_REF_DEREF_MSRV: RustcVersion = RustcVersion::new(1, 40, 0); + +/// lint use of `_.as_ref().map(Deref::deref)` for `Option`s +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &hir::Expr<'_>, + as_ref_args: &[hir::Expr<'_>], + map_args: &[hir::Expr<'_>], + is_mut: bool, + msrv: Option<&RustcVersion>, +) { + if !meets_msrv(msrv, &OPTION_AS_REF_DEREF_MSRV) { + return; + } + + let same_mutability = |m| (is_mut && m == &hir::Mutability::Mut) || (!is_mut && m == &hir::Mutability::Not); + + let option_ty = cx.typeck_results().expr_ty(&as_ref_args[0]); + if !is_type_diagnostic_item(cx, option_ty, sym::option_type) { + return; + } + + let deref_aliases: [&[&str]; 9] = [ + &paths::DEREF_TRAIT_METHOD, + &paths::DEREF_MUT_TRAIT_METHOD, + &paths::CSTRING_AS_C_STR, + &paths::OS_STRING_AS_OS_STR, + &paths::PATH_BUF_AS_PATH, + &paths::STRING_AS_STR, + &paths::STRING_AS_MUT_STR, + &paths::VEC_AS_SLICE, + &paths::VEC_AS_MUT_SLICE, + ]; + + let is_deref = match map_args[1].kind { + hir::ExprKind::Path(ref expr_qpath) => cx + .qpath_res(expr_qpath, map_args[1].hir_id) + .opt_def_id() + .map_or(false, |fun_def_id| { + deref_aliases.iter().any(|path| match_def_path(cx, fun_def_id, path)) + }), + hir::ExprKind::Closure(_, _, body_id, _, _) => { + let closure_body = cx.tcx.hir().body(body_id); + let closure_expr = remove_blocks(&closure_body.value); + + match &closure_expr.kind { + hir::ExprKind::MethodCall(_, _, args, _) => { + if_chain! { + if args.len() == 1; + if path_to_local_id(&args[0], closure_body.params[0].pat.hir_id); + let adj = cx + .typeck_results() + .expr_adjustments(&args[0]) + .iter() + .map(|x| &x.kind) + .collect::<Box<[_]>>(); + if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj; + then { + let method_did = cx.typeck_results().type_dependent_def_id(closure_expr.hir_id).unwrap(); + deref_aliases.iter().any(|path| match_def_path(cx, method_did, path)) + } else { + false + } + } + }, + hir::ExprKind::AddrOf(hir::BorrowKind::Ref, m, ref inner) if same_mutability(m) => { + if_chain! { + if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner1) = inner.kind; + if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner2) = inner1.kind; + then { + path_to_local_id(inner2, closure_body.params[0].pat.hir_id) + } else { + false + } + } + }, + _ => false, + } + }, + _ => false, + }; + + if is_deref { + let current_method = if is_mut { + format!(".as_mut().map({})", snippet(cx, map_args[1].span, "..")) + } else { + format!(".as_ref().map({})", snippet(cx, map_args[1].span, "..")) + }; + let method_hint = if is_mut { "as_deref_mut" } else { "as_deref" }; + let hint = format!("{}.{}()", snippet(cx, as_ref_args[0].span, ".."), method_hint); + let suggestion = format!("try using {} instead", method_hint); + + let msg = format!( + "called `{0}` on an Option value. This can be done more directly \ + by calling `{1}` instead", + current_method, hint + ); + span_lint_and_sugg( + cx, + OPTION_AS_REF_DEREF, + expr.span, + &msg, + &suggestion, + hint, + Applicability::MachineApplicable, + ); + } +} |