Use LanguageItems::require less

Author: camsteffen

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -23,7 +23,6 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Namespace, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{walk_generics, Visitor as _};
-use rustc_hir::lang_items::LangItem;
 use rustc_hir::{GenericArg, GenericArgs, OpaqueTyOrigin};
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
@@ -884,9 +883,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             }
         }
 
-        let sized_def_id = tcx.lang_items().require(LangItem::Sized);
+        let sized_def_id = tcx.lang_items().sized_trait();
         match (&sized_def_id, unbound) {
-            (Ok(sized_def_id), Some(tpb))
+            (Some(sized_def_id), Some(tpb))
                 if tpb.path.res == Res::Def(DefKind::Trait, *sized_def_id) =>
             {
                 // There was in fact a `?Sized` bound, return without doing anything
@@ -906,7 +905,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 // There was no `?Sized` bound; add implicitly sized if `Sized` is available.
             }
         }
-        if sized_def_id.is_err() {
+        if sized_def_id.is_none() {
             // No lang item for `Sized`, so we can't add it as a bound.
             return;
         }

compiler/rustc_middle/src/ty/context.rs

@@ -2456,7 +2456,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     #[inline]
     pub fn mk_lang_item(self, ty: Ty<'tcx>, item: LangItem) -> Option<Ty<'tcx>> {
-        let def_id = self.lang_items().require(item).ok()?;
+        let def_id = self.lang_items().get(item)?;
         Some(self.mk_generic_adt(def_id, ty))
     }
 

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -1019,7 +1019,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         let mut never_suggest_borrow: Vec<_> =
             [LangItem::Copy, LangItem::Clone, LangItem::Unpin, LangItem::Sized]
                 .iter()
-                .filter_map(|lang_item| self.tcx.lang_items().require(*lang_item).ok())
+                .filter_map(|lang_item| self.tcx.lang_items().get(*lang_item))
                 .collect();
 
         if let Some(def_id) = self.tcx.get_diagnostic_item(sym::Send) {

src/tools/clippy/clippy_lints/src/lifetimes.rs

@@ -6,11 +6,12 @@ use rustc_hir::intravisit::{
     walk_fn_decl, walk_generic_param, walk_generics, walk_impl_item_ref, walk_item, walk_param_bound,
     walk_poly_trait_ref, walk_trait_ref, walk_ty, Visitor,
 };
+use rustc_hir::lang_items;
 use rustc_hir::FnRetTy::Return;
 use rustc_hir::{
     BareFnTy, BodyId, FnDecl, GenericArg, GenericBound, GenericParam, GenericParamKind, Generics, Impl, ImplItem,
-    ImplItemKind, Item, ItemKind, LangItem, Lifetime, LifetimeName, ParamName, PolyTraitRef, PredicateOrigin, TraitFn,
-    TraitItem, TraitItemKind, Ty, TyKind, WherePredicate,
+    ImplItemKind, Item, ItemKind, Lifetime, LifetimeName, ParamName, PolyTraitRef, PredicateOrigin, TraitFn, TraitItem,
+    TraitItemKind, Ty, TyKind, WherePredicate,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter as middle_nested_filter;
@@ -364,8 +365,6 @@ fn unique_lifetimes(lts: &[RefLt]) -> usize {
     lts.iter().collect::<FxHashSet<_>>().len()
 }
 
-const CLOSURE_TRAIT_BOUNDS: [LangItem; 3] = [LangItem::Fn, LangItem::FnMut, LangItem::FnOnce];
-
 /// A visitor usable for `rustc_front::visit::walk_ty()`.
 struct RefVisitor<'a, 'tcx> {
     cx: &'a LateContext<'tcx>,
@@ -424,12 +423,8 @@ impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
 
     fn visit_poly_trait_ref(&mut self, poly_tref: &'tcx PolyTraitRef<'tcx>) {
         let trait_ref = &poly_tref.trait_ref;
-        if CLOSURE_TRAIT_BOUNDS.iter().any(|&item| {
-            self.cx
-                .tcx
-                .lang_items()
-                .require(item)
-                .map_or(false, |id| Some(id) == trait_ref.trait_def_id())
+        if let Some(id) = trait_ref.trait_def_id() && lang_items::FN_TRAITS.iter().any(|&item| {
+            self.cx.tcx.lang_items().get(item) == Some(id)
         }) {
             let mut sub_visitor = RefVisitor::new(self.cx);
             sub_visitor.visit_trait_ref(trait_ref);

src/tools/clippy/clippy_lints/src/manual_retain.rs

@@ -92,7 +92,7 @@ fn check_into_iter(
         && match_def_path(cx, filter_def_id, &paths::CORE_ITER_FILTER)
         && let hir::ExprKind::MethodCall(_, struct_expr, [], _) = &into_iter_expr.kind
         && let Some(into_iter_def_id) = cx.typeck_results().type_dependent_def_id(into_iter_expr.hir_id)
-        && cx.tcx.lang_items().require(hir::LangItem::IntoIterIntoIter).ok() == Some(into_iter_def_id)
+        && Some(into_iter_def_id) == cx.tcx.lang_items().into_iter_fn()
         && match_acceptable_type(cx, left_expr, msrv)
         && SpanlessEq::new(cx).eq_expr(left_expr, struct_expr) {
         suggest(cx, parent_expr, left_expr, target_expr);

src/tools/clippy/clippy_lints/src/methods/bind_instead_of_map.rs

@@ -41,7 +41,7 @@ pub(crate) trait BindInsteadOfMap {
     const GOOD_METHOD_NAME: &'static str;
 
     fn no_op_msg(cx: &LateContext<'_>) -> Option<String> {
-        let variant_id = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM).ok()?;
+        let variant_id = cx.tcx.lang_items().get(Self::VARIANT_LANG_ITEM)?;
         let item_id = cx.tcx.parent(variant_id);
         Some(format!(
             "using `{}.{}({})`, which is a no-op",
@@ -52,7 +52,7 @@ pub(crate) trait BindInsteadOfMap {
     }
 
     fn lint_msg(cx: &LateContext<'_>) -> Option<String> {
-        let variant_id = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM).ok()?;
+        let variant_id = cx.tcx.lang_items().get(Self::VARIANT_LANG_ITEM)?;
         let item_id = cx.tcx.parent(variant_id);
         Some(format!(
             "using `{}.{}(|x| {}(y))`, which is more succinctly expressed as `{}(|x| y)`",
@@ -144,7 +144,7 @@ pub(crate) trait BindInsteadOfMap {
     fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, arg: &hir::Expr<'_>) -> bool {
         if_chain! {
             if let Some(adt) = cx.typeck_results().expr_ty(recv).ty_adt_def();
-            if let Ok(vid) = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM);
+            if let Some(vid) = cx.tcx.lang_items().get(Self::VARIANT_LANG_ITEM);
             if adt.did() == cx.tcx.parent(vid);
             then {} else { return false; }
         }
@@ -181,7 +181,7 @@ pub(crate) trait BindInsteadOfMap {
 
     fn is_variant(cx: &LateContext<'_>, res: Res) -> bool {
         if let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Fn), id) = res {
-            if let Ok(variant_id) = cx.tcx.lang_items().require(Self::VARIANT_LANG_ITEM) {
+            if let Some(variant_id) = cx.tcx.lang_items().get(Self::VARIANT_LANG_ITEM) {
                 return cx.tcx.parent(id) == variant_id;
             }
         }

src/tools/clippy/clippy_lints/src/methods/unnecessary_iter_cloned.rs

@@ -5,7 +5,7 @@ use clippy_utils::source::snippet_opt;
 use clippy_utils::ty::{get_associated_type, get_iterator_item_ty, implements_trait};
 use clippy_utils::{fn_def_id, get_parent_expr};
 use rustc_errors::Applicability;
-use rustc_hir::{def_id::DefId, Expr, ExprKind, LangItem};
+use rustc_hir::{def_id::DefId, Expr, ExprKind};
 use rustc_lint::LateContext;
 use rustc_span::{sym, Symbol};
 
@@ -100,5 +100,5 @@ pub fn check_for_loop_iter(
 
 /// Returns true if the named method is `IntoIterator::into_iter`.
 pub fn is_into_iter(cx: &LateContext<'_>, callee_def_id: DefId) -> bool {
-    cx.tcx.lang_items().require(LangItem::IntoIterIntoIter) == Ok(callee_def_id)
+    Some(callee_def_id) == cx.tcx.lang_items().into_iter_fn()
 }

src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs

@@ -7,7 +7,7 @@ use clippy_utils::visitors::find_all_ret_expressions;
 use clippy_utils::{fn_def_id, get_parent_expr, is_diag_item_method, is_diag_trait_item, return_ty};
 use clippy_utils::{meets_msrv, msrvs};
 use rustc_errors::Applicability;
-use rustc_hir::{def_id::DefId, BorrowKind, Expr, ExprKind, ItemKind, LangItem, Node};
+use rustc_hir::{def_id::DefId, BorrowKind, Expr, ExprKind, ItemKind, Node};
 use rustc_hir_typeck::{FnCtxt, Inherited};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::LateContext;
@@ -378,7 +378,7 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
             Node::Expr(parent_expr) => {
                 if let Some((callee_def_id, call_substs, recv, call_args)) = get_callee_substs_and_args(cx, parent_expr)
                 {
-                    if cx.tcx.lang_items().require(LangItem::IntoFutureIntoFuture) == Ok(callee_def_id) {
+                    if Some(callee_def_id) == cx.tcx.lang_items().into_future_fn() {
                         return false;
                     }
 

src/tools/clippy/clippy_lints/src/operators/assign_op_pattern.rs

@@ -28,7 +28,7 @@ pub(super) fn check<'tcx>(
             let rty = cx.typeck_results().expr_ty(rhs);
             if_chain! {
                 if let Some((_, lang_item)) = binop_traits(op.node);
-                if let Ok(trait_id) = cx.tcx.lang_items().require(lang_item);
+                if let Some(trait_id) = cx.tcx.lang_items().get(lang_item);
                 let parent_fn = cx.tcx.hir().get_parent_item(e.hir_id).def_id;
                 if trait_ref_of_method(cx, parent_fn)
                     .map_or(true, |t| t.path.res.def_id() != trait_id);

src/tools/clippy/clippy_lints/src/suspicious_trait_impl.rs

@@ -60,8 +60,8 @@ impl<'tcx> LateLintPass<'tcx> for SuspiciousImpl {
         if_chain! {
             if let hir::ExprKind::Binary(binop, _, _) | hir::ExprKind::AssignOp(binop, ..) = expr.kind;
             if let Some((binop_trait_lang, op_assign_trait_lang)) = binop_traits(binop.node);
-            if let Ok(binop_trait_id) = cx.tcx.lang_items().require(binop_trait_lang);
-            if let Ok(op_assign_trait_id) = cx.tcx.lang_items().require(op_assign_trait_lang);
+            if let Some(binop_trait_id) = cx.tcx.lang_items().get(binop_trait_lang);
+            if let Some(op_assign_trait_id) = cx.tcx.lang_items().get(op_assign_trait_lang);
 
             // Check for more than one binary operation in the implemented function
             // Linting when multiple operations are involved can result in false positives
@@ -78,7 +78,7 @@ impl<'tcx> LateLintPass<'tcx> for SuspiciousImpl {
                 (&OP_ASSIGN_TRAITS, SUSPICIOUS_OP_ASSIGN_IMPL),
             ]
                 .iter()
-                .find(|&(ts, _)| ts.iter().any(|&t| Ok(trait_id) == cx.tcx.lang_items().require(t)));
+                .find(|&(ts, _)| ts.iter().any(|&t| Some(trait_id) == cx.tcx.lang_items().get(t)));
             if count_binops(body.value) == 1;
             then {
                 span_lint(