Auto merge of #123029 - matthiaskrgr:rollup-6qsevhx, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #122858 (Tweak `parse_dot_suffix_expr`)
 - #122982 (Add more comments to the bootstrap code that handles `tests/coverage`)
 - #122990 (Clarify transmute example)
 - #122995 (Clean up unnecessary headers/flags in coverage mir-opt tests)
 - #123003 (CFI: Handle dyn with no principal)
 - #123005 (CFI: Support complex receivers)
 - #123020 (Temporarily remove nnethercote from the review rotation.)

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

16 files changed, 278 insertions, 160 deletions

diff --git a/Cargo.lock b/Cargo.lock
index fd77ecaa0f3..9163538765d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4634,6 +4634,7 @@ dependencies = [
  "rustc_session",
  "rustc_span",
  "rustc_target",
+ "rustc_trait_selection",
  "tracing",
  "twox-hash",
 ]
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index fe17eba0d7b..7e317c3df14 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -16,7 +16,6 @@ use core::mem;
 use core::ops::ControlFlow;
 use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Delimiter, Token, TokenKind};
-use rustc_ast::tokenstream::Spacing;
 use rustc_ast::util::case::Case;
 use rustc_ast::util::classify;
 use rustc_ast::util::parser::{prec_let_scrutinee_needs_par, AssocOp, Fixity};
@@ -999,13 +998,57 @@ impl<'a> Parser<'a> {
     }
 
     pub fn parse_dot_suffix_expr(&mut self, lo: Span, base: P<Expr>) -> PResult<'a, P<Expr>> {
+        // At this point we've consumed something like `expr.` and `self.token` holds the token
+        // after the dot.
         match self.token.uninterpolate().kind {
             token::Ident(..) => self.parse_dot_suffix(base, lo),
             token::Literal(token::Lit { kind: token::Integer, symbol, suffix }) => {
-                Ok(self.parse_expr_tuple_field_access(lo, base, symbol, suffix, None))
+                let ident_span = self.token.span;
+                self.bump();
+                Ok(self.mk_expr_tuple_field_access(lo, ident_span, base, symbol, suffix))
             }
             token::Literal(token::Lit { kind: token::Float, symbol, suffix }) => {
-                Ok(self.parse_expr_tuple_field_access_float(lo, base, symbol, suffix))
+                Ok(match self.break_up_float(symbol, self.token.span) {
+                    // 1e2
+                    DestructuredFloat::Single(sym, _sp) => {
+                        // `foo.1e2`: a single complete dot access, fully consumed. We end up with
+                        // the `1e2` token in `self.prev_token` and the following token in
+                        // `self.token`.
+                        let ident_span = self.token.span;
+                        self.bump();
+                        self.mk_expr_tuple_field_access(lo, ident_span, base, sym, suffix)
+                    }
+                    // 1.
+                    DestructuredFloat::TrailingDot(sym, ident_span, dot_span) => {
+                        // `foo.1.`: a single complete dot access and the start of another.
+                        // We end up with the `sym` (`1`) token in `self.prev_token` and a dot in
+                        // `self.token`.
+                        assert!(suffix.is_none());
+                        self.token = Token::new(token::Ident(sym, IdentIsRaw::No), ident_span);
+                        self.bump_with((Token::new(token::Dot, dot_span), self.token_spacing));
+                        self.mk_expr_tuple_field_access(lo, ident_span, base, sym, None)
+                    }
+                    // 1.2 | 1.2e3
+                    DestructuredFloat::MiddleDot(
+                        sym1,
+                        ident1_span,
+                        _dot_span,
+                        sym2,
+                        ident2_span,
+                    ) => {
+                        // `foo.1.2` (or `foo.1.2e3`): two complete dot accesses. We end up with
+                        // the `sym2` (`2` or `2e3`) token in `self.prev_token` and the following
+                        // token in `self.token`.
+                        let next_token2 =
+                            Token::new(token::Ident(sym2, IdentIsRaw::No), ident2_span);
+                        self.bump_with((next_token2, self.token_spacing));
+                        self.bump();
+                        let base1 =
+                            self.mk_expr_tuple_field_access(lo, ident1_span, base, sym1, None);
+                        self.mk_expr_tuple_field_access(lo, ident2_span, base1, sym2, suffix)
+                    }
+                    DestructuredFloat::Error => base,
+                })
             }
             _ => {
                 self.error_unexpected_after_dot();
@@ -1119,41 +1162,6 @@ impl<'a> Parser<'a> {
         }
     }
 
-    fn parse_expr_tuple_field_access_float(
-        &mut self,
-        lo: Span,
-        base: P<Expr>,
-        float: Symbol,
-        suffix: Option<Symbol>,
-    ) -> P<Expr> {
-        match self.break_up_float(float, self.token.span) {
-            // 1e2
-            DestructuredFloat::Single(sym, _sp) => {
-                self.parse_expr_tuple_field_access(lo, base, sym, suffix, None)
-            }
-            // 1.
-            DestructuredFloat::TrailingDot(sym, ident_span, dot_span) => {
-                assert!(suffix.is_none());
-                self.token = Token::new(token::Ident(sym, IdentIsRaw::No), ident_span);
-                let next_token = (Token::new(token::Dot, dot_span), self.token_spacing);
-                self.parse_expr_tuple_field_access(lo, base, sym, None, Some(next_token))
-            }
-            // 1.2 | 1.2e3
-            DestructuredFloat::MiddleDot(symbol1, ident1_span, dot_span, symbol2, ident2_span) => {
-                self.token = Token::new(token::Ident(symbol1, IdentIsRaw::No), ident1_span);
-                // This needs to be `Spacing::Alone` to prevent regressions.
-                // See issue #76399 and PR #76285 for more details
-                let next_token1 = (Token::new(token::Dot, dot_span), Spacing::Alone);
-                let base1 =
-                    self.parse_expr_tuple_field_access(lo, base, symbol1, None, Some(next_token1));
-                let next_token2 = Token::new(token::Ident(symbol2, IdentIsRaw::No), ident2_span);
-                self.bump_with((next_token2, self.token_spacing)); // `.`
-                self.parse_expr_tuple_field_access(lo, base1, symbol2, suffix, None)
-            }
-            DestructuredFloat::Error => base,
-        }
-    }
-
     /// Parse the field access used in offset_of, matched by `$(e:expr)+`.
     /// Currently returns a list of idents. However, it should be possible in
     /// future to also do array indices, which might be arbitrary expressions.
@@ -1255,24 +1263,18 @@ impl<'a> Parser<'a> {
         Ok(fields.into_iter().collect())
     }
 
-    fn parse_expr_tuple_field_access(
+    fn mk_expr_tuple_field_access(
         &mut self,
         lo: Span,
+        ident_span: Span,
         base: P<Expr>,
         field: Symbol,
         suffix: Option<Symbol>,
-        next_token: Option<(Token, Spacing)>,
     ) -> P<Expr> {
-        match next_token {
-            Some(next_token) => self.bump_with(next_token),
-            None => self.bump(),
-        }
-        let span = self.prev_token.span;
-        let field = ExprKind::Field(base, Ident::new(field, span));
         if let Some(suffix) = suffix {
-            self.expect_no_tuple_index_suffix(span, suffix);
+            self.expect_no_tuple_index_suffix(ident_span, suffix);
         }
-        self.mk_expr(lo.to(span), field)
+        self.mk_expr(lo.to(ident_span), ExprKind::Field(base, Ident::new(field, ident_span)))
     }
 
     /// Parse a function call expression, `expr(...)`.
diff --git a/compiler/rustc_symbol_mangling/Cargo.toml b/compiler/rustc_symbol_mangling/Cargo.toml
index 0ce522c9cab..1c8f1d03670 100644
--- a/compiler/rustc_symbol_mangling/Cargo.toml
+++ b/compiler/rustc_symbol_mangling/Cargo.toml
@@ -15,6 +15,7 @@ rustc_middle = { path = "../rustc_middle" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
+rustc_trait_selection = { path = "../rustc_trait_selection" }
 tracing = "0.1"
 twox-hash = "1.6.3"
 # tidy-alphabetical-end
diff --git a/compiler/rustc_symbol_mangling/src/lib.rs b/compiler/rustc_symbol_mangling/src/lib.rs
index 02bb1fde75c..0588af9bda7 100644
--- a/compiler/rustc_symbol_mangling/src/lib.rs
+++ b/compiler/rustc_symbol_mangling/src/lib.rs
@@ -90,6 +90,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
+#![feature(let_chains)]
 #![allow(internal_features)]
 
 #[macro_use]
diff --git a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
index 367fec0e8fc..3101015281b 100644
--- a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
+++ b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs
@@ -11,6 +11,7 @@ use rustc_data_structures::base_n;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
 use rustc_middle::ty::layout::IntegerExt;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::{
     self, Const, ExistentialPredicate, FloatTy, FnSig, Instance, IntTy, List, Region, RegionKind,
     TermKind, Ty, TyCtxt, UintTy,
@@ -21,7 +22,9 @@ use rustc_span::sym;
 use rustc_target::abi::call::{Conv, FnAbi, PassMode};
 use rustc_target::abi::Integer;
 use rustc_target::spec::abi::Abi;
+use rustc_trait_selection::traits;
 use std::fmt::Write as _;
+use std::iter;
 
 use crate::typeid::TypeIdOptions;
 
@@ -747,9 +750,8 @@ fn transform_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: &List<ty::PolyExistentialPredicate<'tcx>>,
 ) -> &'tcx List<ty::PolyExistentialPredicate<'tcx>> {
-    let predicates: Vec<ty::PolyExistentialPredicate<'tcx>> = predicates
-        .iter()
-        .filter_map(|predicate| match predicate.skip_binder() {
+    tcx.mk_poly_existential_predicates_from_iter(predicates.iter().filter_map(|predicate| {
+        match predicate.skip_binder() {
             ty::ExistentialPredicate::Trait(trait_ref) => {
                 let trait_ref = ty::TraitRef::identity(tcx, trait_ref.def_id);
                 Some(ty::Binder::dummy(ty::ExistentialPredicate::Trait(
@@ -758,9 +760,8 @@ fn transform_predicates<'tcx>(
             }
             ty::ExistentialPredicate::Projection(..) => None,
             ty::ExistentialPredicate::AutoTrait(..) => Some(predicate),
-        })
-        .collect();
-    tcx.mk_poly_existential_predicates(&predicates)
+        }
+    }))
 }
 
 /// Transforms args for being encoded and used in the substitution dictionary.
@@ -1115,51 +1116,46 @@ pub fn typeid_for_instance<'tcx>(
         instance.args = strip_receiver_auto(tcx, instance.args)
     }
 
+    if let Some(impl_id) = tcx.impl_of_method(instance.def_id())
+        && let Some(trait_ref) = tcx.impl_trait_ref(impl_id)
+    {
+        let impl_method = tcx.associated_item(instance.def_id());
+        let method_id = impl_method
+            .trait_item_def_id
+            .expect("Part of a trait implementation, but not linked to the def_id?");
+        let trait_method = tcx.associated_item(method_id);
+        if traits::is_vtable_safe_method(tcx, trait_ref.skip_binder().def_id, trait_method) {
+            // Trait methods will have a Self polymorphic parameter, where the concreteized
+            // implementatation will not. We need to walk back to the more general trait method
+            let trait_ref = tcx.instantiate_and_normalize_erasing_regions(
+                instance.args,
+                ty::ParamEnv::reveal_all(),
+                trait_ref,
+            );
+            let invoke_ty = trait_object_ty(tcx, ty::Binder::dummy(trait_ref));
+
+            // At the call site, any call to this concrete function through a vtable will be
+            // `Virtual(method_id, idx)` with appropriate arguments for the method. Since we have the
+            // original method id, and we've recovered the trait arguments, we can make the callee
+            // instance we're computing the alias set for match the caller instance.
+            //
+            // Right now, our code ignores the vtable index everywhere, so we use 0 as a placeholder.
+            // If we ever *do* start encoding the vtable index, we will need to generate an alias set
+            // based on which vtables we are putting this method into, as there will be more than one
+            // index value when supertraits are involved.
+            instance.def = ty::InstanceDef::Virtual(method_id, 0);
+            let abstract_trait_args =
+                tcx.mk_args_trait(invoke_ty, trait_ref.args.into_iter().skip(1));
+            instance.args = instance.args.rebase_onto(tcx, impl_id, abstract_trait_args);
+        }
+    }
+
     let fn_abi = tcx
         .fn_abi_of_instance(tcx.param_env(instance.def_id()).and((instance, ty::List::empty())))
         .unwrap_or_else(|instance| {
             bug!("typeid_for_instance: couldn't get fn_abi of instance {:?}", instance)
         });
 
-    // If this instance is a method and self is a reference, get the impl it belongs to
-    let impl_def_id = tcx.impl_of_method(instance.def_id());
-    if impl_def_id.is_some() && !fn_abi.args.is_empty() && fn_abi.args[0].layout.ty.is_ref() {
-        // If this impl is not an inherent impl, get the trait it implements
-        if let Some(trait_ref) = tcx.impl_trait_ref(impl_def_id.unwrap()) {
-            // Transform the concrete self into a reference to a trait object
-            let existential_predicate = trait_ref.map_bound(|trait_ref| {
-                ty::ExistentialPredicate::Trait(ty::ExistentialTraitRef::erase_self_ty(
-                    tcx, trait_ref,
-                ))
-            });
-            let existential_predicates = tcx.mk_poly_existential_predicates(&[ty::Binder::dummy(
-                existential_predicate.skip_binder(),
-            )]);
-            // Is the concrete self mutable?
-            let self_ty = if fn_abi.args[0].layout.ty.is_mutable_ptr() {
-                Ty::new_mut_ref(
-                    tcx,
-                    tcx.lifetimes.re_erased,
-                    Ty::new_dynamic(tcx, existential_predicates, tcx.lifetimes.re_erased, ty::Dyn),
-                )
-            } else {
-                Ty::new_imm_ref(
-                    tcx,
-                    tcx.lifetimes.re_erased,
-                    Ty::new_dynamic(tcx, existential_predicates, tcx.lifetimes.re_erased, ty::Dyn),
-                )
-            };
-
-            // Replace the concrete self in an fn_abi clone by the reference to a trait object
-            let mut fn_abi = fn_abi.clone();
-            // HACK(rcvalle): It is okay to not replace or update the entire ArgAbi here because the
-            //   other fields are never used.
-            fn_abi.args[0].layout.ty = self_ty;
-
-            return typeid_for_fnabi(tcx, &fn_abi, options);
-        }
-    }
-
     typeid_for_fnabi(tcx, fn_abi, options)
 }
 
@@ -1171,14 +1167,50 @@ fn strip_receiver_auto<'tcx>(
     let ty::Dynamic(preds, lifetime, kind) = ty.kind() else {
         bug!("Tried to strip auto traits from non-dynamic type {ty}");
     };
-    let filtered_preds =
-        if preds.principal().is_some() {
+    let new_rcvr = if preds.principal().is_some() {
+        let filtered_preds =
             tcx.mk_poly_existential_predicates_from_iter(preds.into_iter().filter(|pred| {
                 !matches!(pred.skip_binder(), ty::ExistentialPredicate::AutoTrait(..))
-            }))
-        } else {
-            ty::List::empty()
-        };
-    let new_rcvr = Ty::new_dynamic(tcx, filtered_preds, *lifetime, *kind);
+            }));
+        Ty::new_dynamic(tcx, filtered_preds, *lifetime, *kind)
+    } else {
+        // If there's no principal type, re-encode it as a unit, since we don't know anything
+        // about it. This technically discards the knowledge that it was a type that was made
+        // into a trait object at some point, but that's not a lot.
+        tcx.types.unit
+    };
     tcx.mk_args_trait(new_rcvr, args.into_iter().skip(1))
 }
+
+fn trait_object_ty<'tcx>(tcx: TyCtxt<'tcx>, poly_trait_ref: ty::PolyTraitRef<'tcx>) -> Ty<'tcx> {
+    assert!(!poly_trait_ref.has_non_region_param());
+    let principal_pred = poly_trait_ref.map_bound(|trait_ref| {
+        ty::ExistentialPredicate::Trait(ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref))
+    });
+    let mut assoc_preds: Vec<_> = traits::supertraits(tcx, poly_trait_ref)
+        .flat_map(|super_poly_trait_ref| {
+            tcx.associated_items(super_poly_trait_ref.def_id())
+                .in_definition_order()
+                .filter(|item| item.kind == ty::AssocKind::Type)
+                .map(move |assoc_ty| {
+                    super_poly_trait_ref.map_bound(|super_trait_ref| {
+                        let alias_ty = ty::AliasTy::new(tcx, assoc_ty.def_id, super_trait_ref.args);
+                        let resolved = tcx.normalize_erasing_regions(
+                            ty::ParamEnv::reveal_all(),
+                            alias_ty.to_ty(tcx),
+                        );
+                        ty::ExistentialPredicate::Projection(ty::ExistentialProjection {
+                            def_id: assoc_ty.def_id,
+                            args: ty::ExistentialTraitRef::erase_self_ty(tcx, super_trait_ref).args,
+                            term: resolved.into(),
+                        })
+                    })
+                })
+        })
+        .collect();
+    assoc_preds.sort_by(|a, b| a.skip_binder().stable_cmp(tcx, &b.skip_binder()));
+    let preds = tcx.mk_poly_existential_predicates_from_iter(
+        iter::once(principal_pred).chain(assoc_preds.into_iter()),
+    );
+    Ty::new_dynamic(tcx, preds, tcx.lifetimes.re_erased, ty::Dyn)
+}
diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs
index dec31548fc8..bb1debfc77d 100644
--- a/library/core/src/intrinsics.rs
+++ b/library/core/src/intrinsics.rs
@@ -1356,7 +1356,7 @@ extern "rust-intrinsic" {
     /// let v_clone = v_orig.clone();
     ///
     /// // This is the suggested, safe way.
-    /// // It does copy the entire vector, though, into a new array.
+    /// // It may copy the entire vector into a new one though, but also may not.
     /// let v_collected = v_clone.into_iter()
     ///                          .map(Some)
     ///                          .collect::<Vec<Option<&i32>>>();
diff --git a/src/bootstrap/src/core/build_steps/test.rs b/src/bootstrap/src/core/build_steps/test.rs
index 6d3163b90b1..f22a9ca604e 100644
--- a/src/bootstrap/src/core/build_steps/test.rs
+++ b/src/bootstrap/src/core/build_steps/test.rs
@@ -1289,9 +1289,9 @@ macro_rules! test_definitions {
 /// Adapted from [`test_definitions`].
 macro_rules! coverage_test_alias {
     ($name:ident {
-        alias_and_mode: $alias_and_mode:expr,
-        default: $default:expr,
-        only_hosts: $only_hosts:expr $(,)?
+        alias_and_mode: $alias_and_mode:expr, // &'static str
+        default: $default:expr, // bool
+        only_hosts: $only_hosts:expr $(,)? // bool
     }) => {
         #[derive(Debug, Clone, PartialEq, Eq, Hash)]
         pub struct $name {
@@ -1309,6 +1309,8 @@ macro_rules! coverage_test_alias {
             const ONLY_HOSTS: bool = $only_hosts;
 
             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+                // Register the mode name as a command-line alias.
+                // This allows `x test coverage-map` and `x test coverage-run`.
                 run.alias($alias_and_mode)
             }
 
@@ -1319,8 +1321,7 @@ macro_rules! coverage_test_alias {
             }
 
             fn run(self, builder: &Builder<'_>) {
-                Coverage { compiler: self.compiler, target: self.target }
-                    .run_unified_suite(builder, Self::MODE)
+                Coverage::run_coverage_tests(builder, self.compiler, self.target, Self::MODE);
             }
         }
     };
@@ -1449,11 +1450,20 @@ host_test!(RunMakeFullDeps {
 
 default_test!(Assembly { path: "tests/assembly", mode: "assembly", suite: "assembly" });
 
-/// Custom test step that is responsible for running the coverage tests
-/// in multiple different modes.
+/// Coverage tests are a bit more complicated than other test suites, because
+/// we want to run the same set of test files in multiple different modes,
+/// in a way that's convenient and flexible when invoked manually.
+///
+/// This combined step runs the specified tests (or all of `tests/coverage`)
+/// in both "coverage-map" and "coverage-run" modes.
+///
+/// Used by:
+/// - `x test coverage`
+/// - `x test tests/coverage`
+/// - `x test tests/coverage/trivial.rs` (etc)
 ///
-/// Each individual mode also has its own alias that will run the tests in
-/// just that mode.
+/// (Each individual mode also has its own step that will run the tests in
+/// just that mode.)
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Coverage {
     pub compiler: Compiler,
@@ -1464,24 +1474,41 @@ impl Coverage {
     const PATH: &'static str = "tests/coverage";
     const SUITE: &'static str = "coverage";
 
-    fn run_unified_suite(&self, builder: &Builder<'_>, mode: &'static str) {
+    /// Runs the coverage test suite (or a user-specified subset) in one mode.
+    ///
+    /// This same function is used by the multi-mode step ([`Coverage`]) and by
+    /// the single-mode steps ([`CoverageMap`] and [`CoverageRun`]), to help
+    /// ensure that they all behave consistently with each other, regardless of
+    /// how the coverage tests have been invoked.
+    fn run_coverage_tests(
+        builder: &Builder<'_>,
+        compiler: Compiler,
+        target: TargetSelection,
+        mode: &'static str,
+    ) {
+        // Like many other test steps, we delegate to a `Compiletest` step to
+        // actually run the tests. (See `test_definitions!`.)
         builder.ensure(Compiletest {
-            compiler: self.compiler,
-            target: self.target,
+            compiler,
+            target,
             mode,
             suite: Self::SUITE,
             path: Self::PATH,
             compare_mode: None,
-        })
+        });
     }
 }
 
 impl Step for Coverage {
     type Output = ();
+    // We rely on the individual CoverageMap/CoverageRun steps to run themselves.
     const DEFAULT: bool = false;
+    // When manually invoked, try to run as much as possible.
+    // Compiletest will automatically skip the "coverage-run" tests if necessary.
     const ONLY_HOSTS: bool = false;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        // Take responsibility for command-line paths within `tests/coverage`.
         run.suite_path(Self::PATH)
     }
 
@@ -1492,20 +1519,26 @@ impl Step for Coverage {
     }
 
     fn run(self, builder: &Builder<'_>) {
-        self.run_unified_suite(builder, CoverageMap::MODE);
-        self.run_unified_suite(builder, CoverageRun::MODE);
+        // Run the specified coverage tests (possibly all of them) in both modes.
+        Self::run_coverage_tests(builder, self.compiler, self.target, CoverageMap::MODE);
+        Self::run_coverage_tests(builder, self.compiler, self.target, CoverageRun::MODE);
     }
 }
 
-// Aliases for running the coverage tests in only one mode.
+// Runs `tests/coverage` in "coverage-map" mode only.
+// Used by `x test` and `x test coverage-map`.
 coverage_test_alias!(CoverageMap {
     alias_and_mode: "coverage-map",
     default: true,
     only_hosts: false,
 });
+// Runs `tests/coverage` in "coverage-run" mode only.
+// Used by `x test` and `x test coverage-run`.
 coverage_test_alias!(CoverageRun {
     alias_and_mode: "coverage-run",
     default: true,
+    // Compiletest knows how to automatically skip these tests when cross-compiling,
+    // but skipping the whole step here makes it clearer that they haven't run at all.
     only_hosts: true,
 });
 
diff --git a/tests/mir-opt/instrument_coverage.bar.InstrumentCoverage.diff b/tests/mir-opt/instrument_coverage.bar.InstrumentCoverage.diff
index dec99ff4601..01b01ea5c17 100644
--- a/tests/mir-opt/instrument_coverage.bar.InstrumentCoverage.diff
+++ b/tests/mir-opt/instrument_coverage.bar.InstrumentCoverage.diff
@@ -4,7 +4,7 @@
   fn bar() -> bool {
       let mut _0: bool;
   
-+     coverage Code(Counter(0)) => /the/src/instrument_coverage.rs:21:1 - 23:2;
++     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:19:1 - 21:2;
 + 
       bb0: {
 +         Coverage::CounterIncrement(0);
diff --git a/tests/mir-opt/instrument_coverage.main.InstrumentCoverage.diff b/tests/mir-opt/instrument_coverage.main.InstrumentCoverage.diff
index 368088d1296..3606a9e3932 100644
--- a/tests/mir-opt/instrument_coverage.main.InstrumentCoverage.diff
+++ b/tests/mir-opt/instrument_coverage.main.InstrumentCoverage.diff
@@ -9,11 +9,11 @@
   
 +     coverage ExpressionId(0) => Expression { lhs: Counter(0), op: Add, rhs: Counter(1) };
 +     coverage ExpressionId(1) => Expression { lhs: Expression(0), op: Subtract, rhs: Counter(1) };
-+     coverage Code(Counter(0)) => /the/src/instrument_coverage.rs:12:1 - 12:11;
-+     coverage Code(Expression(0)) => /the/src/instrument_coverage.rs:13:5 - 14:17;
-+     coverage Code(Expression(1)) => /the/src/instrument_coverage.rs:15:13 - 15:18;
-+     coverage Code(Counter(1)) => /the/src/instrument_coverage.rs:16:10 - 16:11;
-+     coverage Code(Expression(1)) => /the/src/instrument_coverage.rs:18:1 - 18:2;
++     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:10:1 - 10:11;
++     coverage Code(Expression(0)) => $DIR/instrument_coverage.rs:11:5 - 12:17;
++     coverage Code(Expression(1)) => $DIR/instrument_coverage.rs:13:13 - 13:18;
++     coverage Code(Counter(1)) => $DIR/instrument_coverage.rs:14:10 - 14:11;
++     coverage Code(Expression(1)) => $DIR/instrument_coverage.rs:16:1 - 16:2;
 + 
       bb0: {
 +         Coverage::CounterIncrement(0);
diff --git a/tests/mir-opt/instrument_coverage.rs b/tests/mir-opt/instrument_coverage.rs
index 010f7bf4d80..ae63990f253 100644
--- a/tests/mir-opt/instrument_coverage.rs
+++ b/tests/mir-opt/instrument_coverage.rs
@@ -1,11 +1,9 @@
-// skip-filecheck
-// Test that `-C instrument-coverage` injects Coverage statements. The Coverage Counter statements
-// are later converted into LLVM instrprof.increment intrinsics, during codegen.
+// Test that `-C instrument-coverage` injects Coverage statements.
+// The Coverage::CounterIncrement statements are later converted into LLVM
+// instrprof.increment intrinsics, during codegen.
 
 //@ unit-test: InstrumentCoverage
-//@ needs-profiler-support
-//@ ignore-windows
-//@ compile-flags: -C instrument-coverage --remap-path-prefix={{src-base}}=/the/src
+//@ compile-flags: -Cinstrument-coverage -Zno-profiler-runtime
 
 // EMIT_MIR instrument_coverage.main.InstrumentCoverage.diff
 // EMIT_MIR instrument_coverage.bar.InstrumentCoverage.diff
@@ -22,17 +20,9 @@ fn bar() -> bool {
     true
 }
 
-// Note that the MIR with injected coverage intrinsics includes references to source locations,
-// including the source file absolute path. Typically, MIR pretty print output with file
-// references are safe because the file prefixes are substituted with `$DIR`, but in this case
-// the file references are encoded as function arguments, with an `Operand` type representation
-// (`Slice` `Allocation` interned byte array) that cannot be normalized by simple substitution.
-//
-// The first workaround is to use the `SourceMap`-supported `--remap-path-prefix` option; however,
-// the implementation of the `--remap-path-prefix` option currently joins the new prefix and the
-// remaining source path with an OS-specific path separator (`\` on Windows). This difference still
-// shows up in the byte array representation of the path, causing Windows tests to fail to match
-// blessed results baselined with a `/` path separator.
-//
-// Since this `mir-opt` test does not have any significant platform dependencies, other than the
-// path separator differences, the final workaround is to disable testing on Windows.
+// CHECK:     coverage ExpressionId({{[0-9]+}}) =>
+// CHECK-DAG: coverage Code(Counter({{[0-9]+}})) =>
+// CHECK-DAG: coverage Code(Expression({{[0-9]+}})) =>
+// CHECK:     bb0:
+// CHECK-DAG: Coverage::ExpressionUsed({{[0-9]+}})
+// CHECK-DAG: Coverage::CounterIncrement({{[0-9]+}})
diff --git a/tests/mir-opt/instrument_coverage_cleanup.main.CleanupPostBorrowck.diff b/tests/mir-opt/instrument_coverage_cleanup.main.CleanupPostBorrowck.diff
index ff65ca77039..34d011540b9 100644
--- a/tests/mir-opt/instrument_coverage_cleanup.main.CleanupPostBorrowck.diff
+++ b/tests/mir-opt/instrument_coverage_cleanup.main.CleanupPostBorrowck.diff
@@ -5,15 +5,15 @@
       let mut _0: ();
       let mut _1: bool;
   
-      coverage branch { true: BlockMarkerId(0), false: BlockMarkerId(1) } => /the/src/instrument_coverage_cleanup.rs:15:8: 15:36 (#0)
+      coverage branch { true: BlockMarkerId(0), false: BlockMarkerId(1) } => $DIR/instrument_coverage_cleanup.rs:14:8: 14:36 (#0)
   
       coverage ExpressionId(0) => Expression { lhs: Counter(0), op: Subtract, rhs: Counter(1) };
       coverage ExpressionId(1) => Expression { lhs: Counter(1), op: Add, rhs: Expression(0) };
-      coverage Code(Counter(0)) => /the/src/instrument_coverage_cleanup.rs:14:1 - 15:36;
-      coverage Code(Expression(0)) => /the/src/instrument_coverage_cleanup.rs:15:37 - 15:39;
-      coverage Code(Counter(1)) => /the/src/instrument_coverage_cleanup.rs:15:39 - 15:40;
-      coverage Code(Expression(1)) => /the/src/instrument_coverage_cleanup.rs:16:1 - 16:2;
-      coverage Branch { true_term: Expression(0), false_term: Counter(1) } => /the/src/instrument_coverage_cleanup.rs:15:8 - 15:36;
+      coverage Code(Counter(0)) => $DIR/instrument_coverage_cleanup.rs:13:1 - 14:36;
+      coverage Code(Expression(0)) => $DIR/instrument_coverage_cleanup.rs:14:37 - 14:39;
+      coverage Code(Counter(1)) => $DIR/instrument_coverage_cleanup.rs:14:39 - 14:40;
+      coverage Code(Expression(1)) => $DIR/instrument_coverage_cleanup.rs:15:1 - 15:2;
+      coverage Branch { true_term: Expression(0), false_term: Counter(1) } => $DIR/instrument_coverage_cleanup.rs:14:8 - 14:36;
   
       bb0: {
           Coverage::CounterIncrement(0);
diff --git a/tests/mir-opt/instrument_coverage_cleanup.main.InstrumentCoverage.diff b/tests/mir-opt/instrument_coverage_cleanup.main.InstrumentCoverage.diff
index 8757559149a..6756d5c1e1b 100644
--- a/tests/mir-opt/instrument_coverage_cleanup.main.InstrumentCoverage.diff
+++ b/tests/mir-opt/instrument_coverage_cleanup.main.InstrumentCoverage.diff
@@ -5,15 +5,15 @@
       let mut _0: ();
       let mut _1: bool;
   
-      coverage branch { true: BlockMarkerId(0), false: BlockMarkerId(1) } => /the/src/instrument_coverage_cleanup.rs:15:8: 15:36 (#0)
+      coverage branch { true: BlockMarkerId(0), false: BlockMarkerId(1) } => $DIR/instrument_coverage_cleanup.rs:14:8: 14:36 (#0)
   
 +     coverage ExpressionId(0) => Expression { lhs: Counter(0), op: Subtract, rhs: Counter(1) };
 +     coverage ExpressionId(1) => Expression { lhs: Counter(1), op: Add, rhs: Expression(0) };
-+     coverage Code(Counter(0)) => /the/src/instrument_coverage_cleanup.rs:14:1 - 15:36;
-+     coverage Code(Expression(0)) => /the/src/instrument_coverage_cleanup.rs:15:37 - 15:39;
-+     coverage Code(Counter(1)) => /the/src/instrument_coverage_cleanup.rs:15:39 - 15:40;
-+     coverage Code(Expression(1)) => /the/src/instrument_coverage_cleanup.rs:16:1 - 16:2;
-+     coverage Branch { true_term: Expression(0), false_term: Counter(1) } => /the/src/instrument_coverage_cleanup.rs:15:8 - 15:36;
++     coverage Code(Counter(0)) => $DIR/instrument_coverage_cleanup.rs:13:1 - 14:36;
++     coverage Code(Expression(0)) => $DIR/instrument_coverage_cleanup.rs:14:37 - 14:39;
++     coverage Code(Counter(1)) => $DIR/instrument_coverage_cleanup.rs:14:39 - 14:40;
++     coverage Code(Expression(1)) => $DIR/instrument_coverage_cleanup.rs:15:1 - 15:2;
++     coverage Branch { true_term: Expression(0), false_term: Counter(1) } => $DIR/instrument_coverage_cleanup.rs:14:8 - 14:36;
 + 
       bb0: {
 +         Coverage::CounterIncrement(0);
diff --git a/tests/mir-opt/instrument_coverage_cleanup.rs b/tests/mir-opt/instrument_coverage_cleanup.rs
index 8a2fd67139b..7db76339e55 100644
--- a/tests/mir-opt/instrument_coverage_cleanup.rs
+++ b/tests/mir-opt/instrument_coverage_cleanup.rs
@@ -7,7 +7,6 @@
 
 //@ unit-test: InstrumentCoverage
 //@ compile-flags: -Cinstrument-coverage -Zcoverage-options=branch -Zno-profiler-runtime
-//@ compile-flags: --remap-path-prefix={{src-base}}=/the/src
 
 // EMIT_MIR instrument_coverage_cleanup.main.InstrumentCoverage.diff
 // EMIT_MIR instrument_coverage_cleanup.main.CleanupPostBorrowck.diff
diff --git a/tests/ui/sanitizer/cfi-complex-receiver.rs b/tests/ui/sanitizer/cfi-complex-receiver.rs
new file mode 100644
index 00000000000..c3e59258db2
--- /dev/null
+++ b/tests/ui/sanitizer/cfi-complex-receiver.rs
@@ -0,0 +1,42 @@
+// Check that more complex receivers work:
+// * Arc<dyn Foo> as for custom receivers
+// * &dyn Bar<T=Baz> for type constraints
+
+//@ needs-sanitizer-cfi
+// FIXME(#122848) Remove only-linux once OSX CFI binaries work
+//@ only-linux
+//@ compile-flags: --crate-type=bin -Cprefer-dynamic=off -Clto -Zsanitizer=cfi
+//@ compile-flags: -C target-feature=-crt-static -C codegen-units=1 -C opt-level=0
+//@ run-pass
+
+use std::sync::Arc;
+
+trait Foo {
+    fn foo(self: Arc<Self>);
+}
+
+struct FooImpl;
+
+impl Foo for FooImpl {
+    fn foo(self: Arc<Self>) {}
+}
+
+trait Bar {
+    type T;
+    fn bar(&self) -> Self::T;
+}
+
+struct BarImpl;
+
+impl Bar for BarImpl {
+    type T = i32;
+    fn bar(&self) -> Self::T { 7 }
+}
+
+fn main() {
+    let foo: Arc<dyn Foo> = Arc::new(FooImpl);
+    foo.foo();
+
+    let bar: &dyn Bar<T=i32> = &BarImpl;
+    assert_eq!(bar.bar(), 7);
+}
diff --git a/tests/ui/sanitizer/cfi-drop-no-principal.rs b/tests/ui/sanitizer/cfi-drop-no-principal.rs
new file mode 100644
index 00000000000..c1c88c8c71c
--- /dev/null
+++ b/tests/ui/sanitizer/cfi-drop-no-principal.rs
@@ -0,0 +1,21 @@
+// Check that dropping a trait object without a principal trait succeeds
+
+//@ needs-sanitizer-cfi
+// FIXME(#122848) Remove only-linux once OSX CFI binaries works
+//@ only-linux
+//@ compile-flags: --crate-type=bin -Cprefer-dynamic=off -Clto -Zsanitizer=cfi
+//@ compile-flags: -C target-feature=-crt-static -C codegen-units=1 -C opt-level=0
+// FIXME(#118761) Should be run-pass once the labels on drop are compatible.
+// This test is being landed ahead of that to test that the compiler doesn't ICE while labeling the
+// callsite for a drop, but the vtable doesn't have the correct label yet.
+//@ build-pass
+
+struct CustomDrop;
+
+impl Drop for CustomDrop {
+    fn drop(&mut self) {}
+}
+
+fn main() {
+    let _ = Box::new(CustomDrop) as Box<dyn Send>;
+}
diff --git a/triagebot.toml b/triagebot.toml
index 2bcc77ae433..a42bafe148c 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -775,7 +775,6 @@ compiler-team = [
 compiler-team-contributors = [
     "@TaKO8Ki",
     "@Nadrieril",
-    "@nnethercote",
     "@fmease",
     "@fee1-dead",
 ]
@@ -831,17 +830,14 @@ parser = [
     "@compiler-errors",
     "@davidtwco",
     "@estebank",
-    "@nnethercote",
     "@petrochenkov",
     "@spastorino",
 ]
 lexer = [
-    "@nnethercote",
     "@petrochenkov",
     "@estebank",
 ]
 arena = [
-    "@nnethercote",
     "@spastorino",
 ]
 mir = [