Merge ref '32e7a4b92b10' from rust-lang/rust

Pull recent changes from https://github.com/rust-lang/rust via Josh.

Upstream ref: 32e7a4b92b109c24e9822c862a7c74436b50e564
Filtered ref: 56d8aa13f54944edb711f3bdd7013b082dbaa65b

This merge was created using https://github.com/rust-lang/josh-sync.

1 files changed, 11 insertions, 17 deletions

diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
index 69851511fb1..cee15e0f696 100644
--- a/compiler/rustc_monomorphize/src/partitioning.rs
+++ b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -223,11 +223,7 @@ where
         // So even if its mode is LocalCopy, we need to treat it like a root.
         match mono_item.instantiation_mode(cx.tcx) {
             InstantiationMode::GloballyShared { .. } => {}
-            InstantiationMode::LocalCopy => {
-                if !cx.tcx.is_lang_item(mono_item.def_id(), LangItem::Start) {
-                    continue;
-                }
-            }
+            InstantiationMode::LocalCopy => continue,
         }
 
         let characteristic_def_id = characteristic_def_id_of_mono_item(cx.tcx, mono_item);
@@ -654,13 +650,13 @@ fn characteristic_def_id_of_mono_item<'tcx>(
             // its self-type. If the self-type does not provide a characteristic
             // DefId, we use the location of the impl after all.
 
-            if tcx.trait_of_item(def_id).is_some() {
+            if tcx.trait_of_assoc(def_id).is_some() {
                 let self_ty = instance.args.type_at(0);
                 // This is a default implementation of a trait method.
                 return characteristic_def_id_of_type(self_ty).or(Some(def_id));
             }
 
-            if let Some(impl_def_id) = tcx.impl_of_method(def_id) {
+            if let Some(impl_def_id) = tcx.impl_of_assoc(def_id) {
                 if tcx.sess.opts.incremental.is_some()
                     && tcx
                         .trait_id_of_impl(impl_def_id)
@@ -821,10 +817,9 @@ fn mono_item_visibility<'tcx>(
         | InstanceKind::FnPtrAddrShim(..) => return Visibility::Hidden,
     };
 
-    // The `start_fn` lang item is actually a monomorphized instance of a
-    // function in the standard library, used for the `main` function. We don't
-    // want to export it so we tag it with `Hidden` visibility but this symbol
-    // is only referenced from the actual `main` symbol which we unfortunately
+    // Both the `start_fn` lang item and `main` itself should not be exported,
+    // so we give them with `Hidden` visibility but these symbols are
+    // only referenced from the actual `main` symbol which we unfortunately
     // don't know anything about during partitioning/collection. As a result we
     // forcibly keep this symbol out of the `internalization_candidates` set.
     //
@@ -834,7 +829,7 @@ fn mono_item_visibility<'tcx>(
     //        from the `main` symbol we'll generate later.
     //
     //        This may be fixable with a new `InstanceKind` perhaps? Unsure!
-    if tcx.is_lang_item(def_id, LangItem::Start) {
+    if tcx.is_entrypoint(def_id) {
         *can_be_internalized = false;
         return Visibility::Hidden;
     }
@@ -1183,12 +1178,11 @@ fn collect_and_partition_mono_items(tcx: TyCtxt<'_>, (): ()) -> MonoItemPartitio
     let autodiff_items = tcx.arena.alloc_from_iter(autodiff_items);
 
     // Output monomorphization stats per def_id
-    if let SwitchWithOptPath::Enabled(ref path) = tcx.sess.opts.unstable_opts.dump_mono_stats {
-        if let Err(err) =
+    if let SwitchWithOptPath::Enabled(ref path) = tcx.sess.opts.unstable_opts.dump_mono_stats
+        && let Err(err) =
             dump_mono_items_stats(tcx, codegen_units, path, tcx.crate_name(LOCAL_CRATE))
-        {
-            tcx.dcx().emit_fatal(CouldntDumpMonoStats { error: err.to_string() });
-        }
+    {
+        tcx.dcx().emit_fatal(CouldntDumpMonoStats { error: err.to_string() });
     }
 
     if tcx.sess.opts.unstable_opts.print_mono_items {