Auto merge of rust-lang#129076 - matthiaskrgr:rollup-rg8mi2x, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#128410 (Migrate `remap-path-prefix-dwarf` `run-make` test to rmake)
 - rust-lang#128759 (alloc: add ToString specialization for `&&str`)
 - rust-lang#128873 (Add windows-targets crate to std's sysroot)
 - rust-lang#129001 (chore(lib): Enhance documentation for core::fmt::Formatter's write_fm…)
 - rust-lang#129061 (Use `is_lang_item` more)
 - rust-lang#129062 (Remove a no-longer-true assert)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_hir_typeck/src/check.rs

@@ -160,15 +160,11 @@ pub(super) fn check_fn<'a, 'tcx>(
     fcx.demand_suptype(span, ret_ty, actual_return_ty);
 
     // Check that a function marked as `#[panic_handler]` has signature `fn(&PanicInfo) -> !`
-    if let Some(panic_impl_did) = tcx.lang_items().panic_impl()
-        && panic_impl_did == fn_def_id.to_def_id()
-    {
-        check_panic_info_fn(tcx, panic_impl_did.expect_local(), fn_sig);
+    if tcx.is_lang_item(fn_def_id.to_def_id(), LangItem::PanicImpl) {
+        check_panic_info_fn(tcx, fn_def_id, fn_sig);
     }
 
-    if let Some(lang_start_defid) = tcx.lang_items().start_fn()
-        && lang_start_defid == fn_def_id.to_def_id()
-    {
+    if tcx.is_lang_item(fn_def_id.to_def_id(), LangItem::Start) {
         check_lang_start_fn(tcx, fn_sig, fn_def_id);
     }
 

compiler/rustc_lint/src/for_loops_over_fallibles.rs

@@ -1,5 +1,5 @@
 use hir::{Expr, Pat};
-use rustc_hir as hir;
+use rustc_hir::{self as hir, LangItem};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::ty;
@@ -126,7 +126,10 @@ fn extract_iterator_next_call<'tcx>(
 ) -> Option<&'tcx Expr<'tcx>> {
     // This won't work for `Iterator::next(iter)`, is this an issue?
     if let hir::ExprKind::MethodCall(_, recv, _, _) = expr.kind
-        && cx.typeck_results().type_dependent_def_id(expr.hir_id) == cx.tcx.lang_items().next_fn()
+        && cx
+            .typeck_results()
+            .type_dependent_def_id(expr.hir_id)
+            .is_some_and(|def_id| cx.tcx.is_lang_item(def_id, LangItem::IteratorNext))
     {
         Some(recv)
     } else {

compiler/rustc_lint/src/traits.rs

@@ -114,7 +114,7 @@ impl<'tcx> LateLintPass<'tcx> for DropTraitConstraints {
         let hir::TyKind::TraitObject(bounds, _lifetime, _syntax) = &ty.kind else { return };
         for (bound, modifier) in &bounds[..] {
             let def_id = bound.trait_ref.trait_def_id();
-            if cx.tcx.lang_items().drop_trait() == def_id
+            if def_id.is_some_and(|def_id| cx.tcx.is_lang_item(def_id, LangItem::Drop))
                 && *modifier != hir::TraitBoundModifier::Maybe
             {
                 let Some(def_id) = cx.tcx.get_diagnostic_item(sym::needs_drop) else { return };

compiler/rustc_middle/src/ty/diagnostics.rs

@@ -6,10 +6,9 @@ use std::ops::ControlFlow;
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{into_diag_arg_using_display, Applicability, Diag, DiagArgValue, IntoDiagArg};
-use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
-use rustc_hir::{PredicateOrigin, WherePredicate};
+use rustc_hir::{self as hir, LangItem, PredicateOrigin, WherePredicate};
 use rustc_span::{BytePos, Span};
 use rustc_type_ir::TyKind::*;
 
@@ -290,8 +289,9 @@ pub fn suggest_constraining_type_params<'a>(
         let Some(param) = param else { return false };
 
         {
-            let mut sized_constraints =
-                constraints.extract_if(|(_, def_id)| *def_id == tcx.lang_items().sized_trait());
+            let mut sized_constraints = constraints.extract_if(|(_, def_id)| {
+                def_id.is_some_and(|def_id| tcx.is_lang_item(def_id, LangItem::Sized))
+            });
             if let Some((_, def_id)) = sized_constraints.next() {
                 applicability = Applicability::MaybeIncorrect;
 

compiler/rustc_middle/src/ty/instance.rs

@@ -838,7 +838,7 @@ impl<'tcx> Instance<'tcx> {
             return None;
         };
 
-        if tcx.lang_items().get(coroutine_callable_item) == Some(trait_item_id) {
+        if tcx.is_lang_item(trait_item_id, coroutine_callable_item) {
             let ty::Coroutine(_, id_args) = *tcx.type_of(coroutine_def_id).skip_binder().kind()
             else {
                 bug!()

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1145,7 +1145,9 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
                         let term = if let Some(ty) = term.skip_binder().as_type()
                             && let ty::Alias(ty::Projection, proj) = ty.kind()
                             && let Some(assoc) = tcx.opt_associated_item(proj.def_id)
-                            && assoc.trait_container(tcx) == tcx.lang_items().coroutine_trait()
+                            && assoc
+                                .trait_container(tcx)
+                                .is_some_and(|def_id| tcx.is_lang_item(def_id, LangItem::Coroutine))
                             && assoc.name == rustc_span::sym::Return
                         {
                             if let ty::Coroutine(_, args) = args.type_at(0).kind() {

compiler/rustc_middle/src/ty/sty.rs

@@ -1916,7 +1916,7 @@ impl<'tcx> Ty<'tcx> {
 
     pub fn is_c_void(self, tcx: TyCtxt<'_>) -> bool {
         match self.kind() {
-            ty::Adt(adt, _) => tcx.lang_items().get(LangItem::CVoid) == Some(adt.did()),
+            ty::Adt(adt, _) => tcx.is_lang_item(adt.did(), LangItem::CVoid),
             _ => false,
         }
     }

compiler/rustc_mir_build/src/thir/pattern/check_match.rs

@@ -702,10 +702,12 @@ impl<'p, 'tcx> MatchVisitor<'p, 'tcx> {
             && adt.is_enum()
             && let Constructor::Variant(variant_index) = witness_1.ctor()
         {
-            let variant = adt.variant(*variant_index);
-            let inhabited = variant.inhabited_predicate(self.tcx, *adt).instantiate(self.tcx, args);
-            assert!(inhabited.apply(self.tcx, cx.param_env, cx.module));
-            !inhabited.apply_ignore_module(self.tcx, cx.param_env)
+            let variant_inhabited = adt
+                .variant(*variant_index)
+                .inhabited_predicate(self.tcx, *adt)
+                .instantiate(self.tcx, args);
+            variant_inhabited.apply(self.tcx, cx.param_env, cx.module)
+                && !variant_inhabited.apply_ignore_module(self.tcx, cx.param_env)
         } else {
             false
         };

compiler/rustc_monomorphize/src/partitioning.rs

@@ -648,7 +648,9 @@ fn characteristic_def_id_of_mono_item<'tcx>(
 
             if let Some(impl_def_id) = tcx.impl_of_method(def_id) {
                 if tcx.sess.opts.incremental.is_some()
-                    && tcx.trait_id_of_impl(impl_def_id) == tcx.lang_items().drop_trait()
+                    && tcx
+                        .trait_id_of_impl(impl_def_id)
+                        .is_some_and(|def_id| tcx.is_lang_item(def_id, LangItem::Drop))
                 {
                     // Put `Drop::drop` into the same cgu as `drop_in_place`
                     // since `drop_in_place` is the only thing that can

compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs

@@ -4,6 +4,7 @@ use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
+use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::print::{FmtPrinter, Printer};
 use rustc_middle::ty::{self, suggest_constraining_type_param, Ty};
 use rustc_span::def_id::DefId;
@@ -313,11 +314,15 @@ impl<T> Trait<T> for X {
                     (ty::Dynamic(t, _, ty::DynKind::Dyn), _)
                         if let Some(def_id) = t.principal_def_id() =>
                     {
-                        let mut impl_def_ids = vec![];
+                        let mut has_matching_impl = false;
                         tcx.for_each_relevant_impl(def_id, values.found, |did| {
-                            impl_def_ids.push(did)
+                            if DeepRejectCtxt::new(tcx, TreatParams::ForLookup)
+                                .types_may_unify(values.found, tcx.type_of(did).skip_binder())
+                            {
+                                has_matching_impl = true;
+                            }
                         });
-                        if let [_] = &impl_def_ids[..] {
+                        if has_matching_impl {
                             let trait_name = tcx.item_name(def_id);
                             diag.help(format!(
                                 "`{}` implements `{trait_name}` so you could box the found value \
@@ -330,11 +335,15 @@ impl<T> Trait<T> for X {
                     (_, ty::Dynamic(t, _, ty::DynKind::Dyn))
                         if let Some(def_id) = t.principal_def_id() =>
                     {
-                        let mut impl_def_ids = vec![];
+                        let mut has_matching_impl = false;
                         tcx.for_each_relevant_impl(def_id, values.expected, |did| {
-                            impl_def_ids.push(did)
+                            if DeepRejectCtxt::new(tcx, TreatParams::ForLookup)
+                                .types_may_unify(values.expected, tcx.type_of(did).skip_binder())
+                            {
+                                has_matching_impl = true;
+                            }
                         });
-                        if let [_] = &impl_def_ids[..] {
+                        if has_matching_impl {
                             let trait_name = tcx.item_name(def_id);
                             diag.help(format!(
                                 "`{}` implements `{trait_name}` so you could change the expected \
@@ -346,11 +355,15 @@ impl<T> Trait<T> for X {
                     (ty::Dynamic(t, _, ty::DynKind::DynStar), _)
                         if let Some(def_id) = t.principal_def_id() =>
                     {
-                        let mut impl_def_ids = vec![];
+                        let mut has_matching_impl = false;
                         tcx.for_each_relevant_impl(def_id, values.found, |did| {
-                            impl_def_ids.push(did)
+                            if DeepRejectCtxt::new(tcx, TreatParams::ForLookup)
+                                .types_may_unify(values.found, tcx.type_of(did).skip_binder())
+                            {
+                                has_matching_impl = true;
+                            }
                         });
-                        if let [_] = &impl_def_ids[..] {
+                        if has_matching_impl {
                             let trait_name = tcx.item_name(def_id);
                             diag.help(format!(
                                 "`{}` implements `{trait_name}`, `#[feature(dyn_star)]` is likely \