Auto merge of #101167 - matthiaskrgr:rollup-yt3jdmp, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #100898 (Do not report too many expr field candidates)
 - #101056 (Add the syntax of references to their documentation summary.)
 - #101106 (Rustdoc-Json: Retain Stripped Modules when they are imported, not when they have items)
 - #101131 (CTFE: exposing pointers and calling extern fn is just impossible)
 - #101141 (Simplify `get_trait_ref` fn used for `virtual_function_elimination`)
 - #101146 (Various changes to logging of borrowck-related code)
 - #101156 (Remove `Sync` requirement from lint pass objects)

Failed merges:

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

1 files changed, 7 insertions, 11 deletions

diff --git a/compiler/rustc_codegen_ssa/src/meth.rs b/compiler/rustc_codegen_ssa/src/meth.rs
index 27d791d90a5..f8e982b7751 100644
--- a/compiler/rustc_codegen_ssa/src/meth.rs
+++ b/compiler/rustc_codegen_ssa/src/meth.rs
@@ -1,6 +1,6 @@
 use crate::traits::*;
 
-use rustc_middle::ty::{self, subst::GenericArgKind, ExistentialPredicate, Ty, TyCtxt};
+use rustc_middle::ty::{self, subst::GenericArgKind, Ty};
 use rustc_session::config::Lto;
 use rustc_symbol_mangling::typeid_for_trait_ref;
 use rustc_target::abi::call::FnAbi;
@@ -29,7 +29,7 @@ impl<'a, 'tcx> VirtualIndex {
             && bx.cx().sess().lto() == Lto::Fat
         {
             let typeid =
-                bx.typeid_metadata(typeid_for_trait_ref(bx.tcx(), get_trait_ref(bx.tcx(), ty)));
+                bx.typeid_metadata(typeid_for_trait_ref(bx.tcx(), expect_dyn_trait_in_self(ty)));
             let vtable_byte_offset = self.0 * bx.data_layout().pointer_size.bytes();
             let type_checked_load = bx.type_checked_load(llvtable, vtable_byte_offset, typeid);
             let func = bx.extract_value(type_checked_load, 0);
@@ -64,17 +64,13 @@ impl<'a, 'tcx> VirtualIndex {
     }
 }
 
-fn get_trait_ref<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> ty::PolyExistentialTraitRef<'tcx> {
+/// This takes a valid `self` receiver type and extracts the principal trait
+/// ref of the type.
+fn expect_dyn_trait_in_self<'tcx>(ty: Ty<'tcx>) -> ty::PolyExistentialTraitRef<'tcx> {
     for arg in ty.peel_refs().walk() {
         if let GenericArgKind::Type(ty) = arg.unpack() {
-            if let ty::Dynamic(trait_refs, _) = ty.kind() {
-                return trait_refs[0].map_bound(|trait_ref| match trait_ref {
-                    ExistentialPredicate::Trait(tr) => tr,
-                    ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
-                    ExistentialPredicate::AutoTrait(_) => {
-                        bug!("auto traits don't have functions")
-                    }
-                });
+            if let ty::Dynamic(data, _) = ty.kind() {
+                return data.principal().expect("expected principal trait object");
             }
         }
     }