Remove lang_items\(\).*\.unwrap\(\)

Author: cofibrant

src/librustc_mir/monomorphize/mod.rs

@@ -2,6 +2,8 @@ use rustc_middle::traits;
 use rustc_middle::ty::adjustment::CustomCoerceUnsized;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 
+use rustc_hir::lang_items::CoerceUnsizedTraitLangItem;
+
 pub mod collector;
 pub mod partitioning;
 
@@ -10,7 +12,7 @@ pub fn custom_coerce_unsize_info<'tcx>(
     source_ty: Ty<'tcx>,
     target_ty: Ty<'tcx>,
 ) -> CustomCoerceUnsized {
-    let def_id = tcx.lang_items().coerce_unsized_trait().unwrap();
+    let def_id = tcx.require_lang_item(CoerceUnsizedTraitLangItem, None);
 
     let trait_ref = ty::Binder::bind(ty::TraitRef {
         def_id,

src/librustc_mir_build/hair/pattern/const_to_pat.rs

@@ -141,7 +141,8 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> {
                 // code at the moment, because types like `for <'a> fn(&'a ())` do
                 // not *yet* implement `PartialEq`. So for now we leave this here.
                 let ty_is_partial_eq: bool = {
-                    let partial_eq_trait_id = self.tcx().require_lang_item(EqTraitLangItem, None);
+                    let partial_eq_trait_id =
+                        self.tcx().require_lang_item(EqTraitLangItem, Some(self.span));
                     let obligation: PredicateObligation<'_> = predicate_for_trait_def(
                         self.tcx(),
                         self.param_env,

src/librustc_trait_selection/traits/structural_match.rs

@@ -4,6 +4,7 @@ use crate::traits::{self, ConstPatternStructural, TraitEngine};
 
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
+use rustc_hir::lang_items::{StructuralPeqTraitLangItem, StructuralTeqTraitLangItem};
 use rustc_middle::ty::{self, AdtDef, Ty, TyCtxt, TypeFoldable, TypeVisitor};
 use rustc_span::Span;
 
@@ -69,7 +70,7 @@ pub fn type_marked_structural(
     let mut fulfillment_cx = traits::FulfillmentContext::new();
     let cause = ObligationCause::new(span, id, ConstPatternStructural);
     // require `#[derive(PartialEq)]`
-    let structural_peq_def_id = infcx.tcx.lang_items().structural_peq_trait().unwrap();
+    let structural_peq_def_id = infcx.tcx.require_lang_item(StructuralPeqTraitLangItem, Some(span));
     fulfillment_cx.register_bound(
         infcx,
         ty::ParamEnv::empty(),
@@ -80,7 +81,7 @@ pub fn type_marked_structural(
     // for now, require `#[derive(Eq)]`. (Doing so is a hack to work around
     // the type `for<'a> fn(&'a ())` failing to implement `Eq` itself.)
     let cause = ObligationCause::new(span, id, ConstPatternStructural);
-    let structural_teq_def_id = infcx.tcx.lang_items().structural_teq_trait().unwrap();
+    let structural_teq_def_id = infcx.tcx.require_lang_item(StructuralTeqTraitLangItem, Some(span));
     fulfillment_cx.register_bound(
         infcx,
         ty::ParamEnv::empty(),

src/librustc_typeck/check/closure.rs

@@ -6,7 +6,7 @@ use crate::astconv::AstConv;
 use crate::middle::region;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
-use rustc_hir::lang_items;
+use rustc_hir::lang_items::{FutureTraitLangItem, GeneratorTraitLangItem};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::LateBoundRegionConversionTime;
 use rustc_infer::infer::{InferOk, InferResult};
@@ -245,7 +245,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let trait_ref = projection.to_poly_trait_ref(tcx);
 
         let is_fn = tcx.fn_trait_kind_from_lang_item(trait_ref.def_id()).is_some();
-        let gen_trait = tcx.require_lang_item(lang_items::GeneratorTraitLangItem, cause_span);
+        let gen_trait = tcx.require_lang_item(GeneratorTraitLangItem, cause_span);
         let is_gen = gen_trait == trait_ref.def_id();
         if !is_fn && !is_gen {
             debug!("deduce_sig_from_projection: not fn or generator");
@@ -678,7 +678,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         // Check that this is a projection from the `Future` trait.
         let trait_ref = predicate.projection_ty.trait_ref(self.tcx);
-        let future_trait = self.tcx.lang_items().future_trait().unwrap();
+        let future_trait = self.tcx.require_lang_item(FutureTraitLangItem, Some(cause_span));
         if trait_ref.def_id != future_trait {
             debug!("deduce_future_output_from_projection: not a future");
             return None;

src/librustc_typeck/check/demand.rs

@@ -7,7 +7,7 @@ use rustc_trait_selection::traits::{self, ObligationCause};
 use rustc_ast::util::parser::PREC_POSTFIX;
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
-use rustc_hir::lang_items::DerefTraitLangItem;
+use rustc_hir::lang_items::{CloneTraitLangItem, DerefTraitLangItem};
 use rustc_hir::{is_range_literal, Node};
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::{self, AssocItem, Ty, TypeAndMut};
@@ -456,8 +456,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 };
                 if self.can_coerce(ref_ty, expected) {
                     let mut sugg_sp = sp;
-                    if let hir::ExprKind::MethodCall(segment, _sp, args) = &expr.kind {
-                        let clone_trait = self.tcx.lang_items().clone_trait().unwrap();
+                    if let hir::ExprKind::MethodCall(ref segment, sp, ref args) = expr.kind {
+                        let clone_trait = self.tcx.require_lang_item(CloneTraitLangItem, Some(sp));
                         if let ([arg], Some(true), sym::clone) = (
                             &args[..],
                             self.tables.borrow().type_dependent_def_id(expr.hir_id).map(|did| {
@@ -635,7 +635,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             _ if sp == expr.span && !is_macro => {
                 // Check for `Deref` implementations by constructing a predicate to
                 // prove: `<T as Deref>::Output == U`
-                let deref_trait = self.tcx.require_lang_item(DerefTraitLangItem, Some(expr.span));
+                let deref_trait = self.tcx.require_lang_item(DerefTraitLangItem, Some(sp));
                 let item_def_id = self
                     .tcx
                     .associated_items(deref_trait)

src/librustc_typeck/check/mod.rs

@@ -100,7 +100,9 @@ use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LOCAL_CRATE};
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
-use rustc_hir::lang_items;
+use rustc_hir::lang_items::{
+    FutureTraitLangItem, PinTypeLangItem, SizedTraitLangItem, VaListTypeLangItem,
+};
 use rustc_hir::{ExprKind, GenericArg, HirIdMap, Item, ItemKind, Node, PatKind, QPath};
 use rustc_index::bit_set::BitSet;
 use rustc_index::vec::Idx;
@@ -1342,10 +1344,8 @@ fn check_fn<'a, 'tcx>(
     // C-variadic fns also have a `VaList` input that's not listed in `fn_sig`
     // (as it's created inside the body itself, not passed in from outside).
     let maybe_va_list = if fn_sig.c_variadic {
-        let va_list_did = tcx.require_lang_item(
-            lang_items::VaListTypeLangItem,
-            Some(body.params.last().unwrap().span),
-        );
+        let va_list_did =
+            tcx.require_lang_item(VaListTypeLangItem, Some(body.params.last().unwrap().span));
         let region = tcx.mk_region(ty::ReScope(region::Scope {
             id: body.value.hir_id.local_id,
             data: region::ScopeData::CallSite,
@@ -3303,7 +3303,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         code: traits::ObligationCauseCode<'tcx>,
     ) {
         if !ty.references_error() {
-            let lang_item = self.tcx.require_lang_item(lang_items::SizedTraitLangItem, None);
+            let lang_item = self.tcx.require_lang_item(SizedTraitLangItem, None);
             self.require_type_meets(ty, span, code, lang_item);
         }
     }
@@ -5142,7 +5142,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             _ => {}
         }
         let boxed_found = self.tcx.mk_box(found);
-        let new_found = self.tcx.mk_lang_item(boxed_found, lang_items::PinTypeLangItem).unwrap();
+        let new_found = self.tcx.mk_lang_item(boxed_found, PinTypeLangItem).unwrap();
         if let (true, Ok(snippet)) = (
             self.can_coerce(new_found, expected),
             self.sess().source_map().span_to_snippet(expr.span),
@@ -5298,7 +5298,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let sp = expr.span;
                 // Check for `Future` implementations by constructing a predicate to
                 // prove: `<T as Future>::Output == U`
-                let future_trait = self.tcx.lang_items().future_trait().unwrap();
+                let future_trait = self.tcx.require_lang_item(FutureTraitLangItem, Some(sp));
                 let item_def_id = self
                     .tcx
                     .associated_items(future_trait)

src/librustc_typeck/coherence/builtin.rs

@@ -4,7 +4,9 @@
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
-use rustc_hir::lang_items::UnsizeTraitLangItem;
+use rustc_hir::lang_items::{
+    CoerceUnsizedTraitLangItem, DispatchFromDynTraitLangItem, UnsizeTraitLangItem,
+};
 use rustc_hir::ItemKind;
 use rustc_infer::infer;
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
@@ -145,11 +147,11 @@ fn visit_implementation_of_coerce_unsized(tcx: TyCtxt<'tcx>, impl_did: LocalDefI
 fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
     debug!("visit_implementation_of_dispatch_from_dyn: impl_did={:?}", impl_did);
 
-    let dispatch_from_dyn_trait = tcx.lang_items().dispatch_from_dyn_trait().unwrap();
-
     let impl_hir_id = tcx.hir().as_local_hir_id(impl_did);
     let span = tcx.hir().span(impl_hir_id);
 
+    let dispatch_from_dyn_trait = tcx.require_lang_item(DispatchFromDynTraitLangItem, Some(span));
+
     let source = tcx.type_of(impl_did);
     assert!(!source.has_escaping_bound_vars());
     let target = {
@@ -314,22 +316,23 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDef
 
 pub fn coerce_unsized_info(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUnsizedInfo {
     debug!("compute_coerce_unsized_info(impl_did={:?})", impl_did);
-    let coerce_unsized_trait = tcx.lang_items().coerce_unsized_trait().unwrap();
+
+    // this provider should only get invoked for local def-ids
+    let impl_hir_id = tcx.hir().as_local_hir_id(impl_did.expect_local());
+    let span = tcx.hir().span(impl_hir_id);
+
+    let coerce_unsized_trait = tcx.require_lang_item(CoerceUnsizedTraitLangItem, Some(span));
 
     let unsize_trait = tcx.lang_items().require(UnsizeTraitLangItem).unwrap_or_else(|err| {
         tcx.sess.fatal(&format!("`CoerceUnsized` implementation {}", err));
     });
 
-    // this provider should only get invoked for local def-ids
-    let impl_hir_id = tcx.hir().as_local_hir_id(impl_did.expect_local());
-
     let source = tcx.type_of(impl_did);
     let trait_ref = tcx.impl_trait_ref(impl_did).unwrap();
     assert_eq!(trait_ref.def_id, coerce_unsized_trait);
     let target = trait_ref.substs.type_at(1);
     debug!("visit_implementation_of_coerce_unsized: {:?} -> {:?} (bound)", source, target);
 
-    let span = tcx.hir().span(impl_hir_id);
     let param_env = tcx.param_env(impl_did);
     assert!(!source.has_escaping_bound_vars());