Auto merge of #120748 - Nadrieril:rollup-dj0qwv5, r=Nadrieril

Rollup of 13 pull requests

Successful merges:

 - #110482 (Add armv8r-none-eabihf target for the Cortex-R52.)
 - #119162 (Add unstable `-Z direct-access-external-data` cmdline flag for `rustc`)
 - #120302 (various const interning cleanups)
 - #120455 ( Add FileCheck annotations to MIR-opt SROA tests)
 - #120470 (Mark "unused binding" suggestion as maybe incorrect)
 - #120479 (Suggest turning `if let` into irrefutable `let` if appropriate)
 - #120564 (coverage: Split out counter increment sites from BCB node/edge counters)
 - #120633 (pattern_analysis: gather up place-relevant info)
 - #120664 (Add parallel rustc ui tests)
 - #120726 (Don't use bashism in checktools.sh)
 - #120733 (MirPass: make name more const)
 - #120735 (Remove some `unchecked_claim_error_was_emitted` calls)
 - #120746 (Record coroutine kind in coroutine generics)

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

53 files changed, 944 insertions, 395 deletions

diff --git a/compiler/rustc_codegen_llvm/src/mono_item.rs b/compiler/rustc_codegen_llvm/src/mono_item.rs
index f796ce0990f..f7630719368 100644
--- a/compiler/rustc_codegen_llvm/src/mono_item.rs
+++ b/compiler/rustc_codegen_llvm/src/mono_item.rs
@@ -123,6 +123,17 @@ impl CodegenCx<'_, '_> {
             return false;
         }
 
+        // Match clang by only supporting COFF and ELF for now.
+        if self.tcx.sess.target.is_like_osx {
+            return false;
+        }
+
+        // With pie relocation model calls of functions defined in the translation
+        // unit can use copy relocations.
+        if self.tcx.sess.relocation_model() == RelocModel::Pie && !is_declaration {
+            return true;
+        }
+
         // Thread-local variables generally don't support copy relocations.
         let is_thread_local_var = llvm::LLVMIsAGlobalVariable(llval)
             .is_some_and(|v| llvm::LLVMIsThreadLocal(v) == llvm::True);
@@ -130,18 +141,12 @@ impl CodegenCx<'_, '_> {
             return false;
         }
 
-        // Match clang by only supporting COFF and ELF for now.
-        if self.tcx.sess.target.is_like_osx {
-            return false;
+        // Respect the direct-access-external-data to override default behavior if present.
+        if let Some(direct) = self.tcx.sess.direct_access_external_data() {
+            return direct;
         }
 
         // Static relocation model should force copy relocations everywhere.
-        if self.tcx.sess.relocation_model() == RelocModel::Static {
-            return true;
-        }
-
-        // With pie relocation model calls of functions defined in the translation
-        // unit can use copy relocations.
-        self.tcx.sess.relocation_model() == RelocModel::Pie && !is_declaration
+        self.tcx.sess.relocation_model() == RelocModel::Static
     }
 }
diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
index 6a92ed9717d..a2d0f1c5583 100644
--- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
+++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
@@ -1,5 +1,3 @@
-use std::mem;
-
 use either::{Left, Right};
 
 use rustc_hir::def::DefKind;
@@ -24,12 +22,13 @@ use crate::interpret::{
 };
 
 // Returns a pointer to where the result lives
+#[instrument(level = "trace", skip(ecx, body), ret)]
 fn eval_body_using_ecx<'mir, 'tcx>(
     ecx: &mut CompileTimeEvalContext<'mir, 'tcx>,
     cid: GlobalId<'tcx>,
     body: &'mir mir::Body<'tcx>,
 ) -> InterpResult<'tcx, MPlaceTy<'tcx>> {
-    debug!("eval_body_using_ecx: {:?}, {:?}", cid, ecx.param_env);
+    trace!(?ecx.param_env);
     let tcx = *ecx.tcx;
     assert!(
         cid.promoted.is_some()
@@ -75,11 +74,8 @@ fn eval_body_using_ecx<'mir, 'tcx>(
             None => InternKind::Constant,
         }
     };
-    let check_alignment = mem::replace(&mut ecx.machine.check_alignment, CheckAlignment::No); // interning doesn't need to respect alignment
     intern_const_alloc_recursive(ecx, intern_kind, &ret)?;
-    ecx.machine.check_alignment = check_alignment;
 
-    debug!("eval_body_using_ecx done: {:?}", ret);
     Ok(ret)
 }
 
diff --git a/compiler/rustc_const_eval/src/interpret/intern.rs b/compiler/rustc_const_eval/src/interpret/intern.rs
index 751fbfacaad..38e7843761b 100644
--- a/compiler/rustc_const_eval/src/interpret/intern.rs
+++ b/compiler/rustc_const_eval/src/interpret/intern.rs
@@ -41,13 +41,12 @@ pub trait CompileTimeMachine<'mir, 'tcx: 'mir, T> = Machine<
 /// allocation is interned immutably; if it is `Mutability::Mut`, then the allocation *must be*
 /// already mutable (as a sanity check).
 ///
-/// `recursive_alloc` is called for all recursively encountered allocations.
+/// Returns an iterator over all relocations referred to by this allocation.
 fn intern_shallow<'rt, 'mir, 'tcx, T, M: CompileTimeMachine<'mir, 'tcx, T>>(
     ecx: &'rt mut InterpCx<'mir, 'tcx, M>,
     alloc_id: AllocId,
     mutability: Mutability,
-    mut recursive_alloc: impl FnMut(&InterpCx<'mir, 'tcx, M>, CtfeProvenance),
-) -> Result<(), ()> {
+) -> Result<impl Iterator<Item = CtfeProvenance> + 'tcx, ()> {
     trace!("intern_shallow {:?}", alloc_id);
     // remove allocation
     let Some((_kind, mut alloc)) = ecx.memory.alloc_map.remove(&alloc_id) else {
@@ -65,14 +64,10 @@ fn intern_shallow<'rt, 'mir, 'tcx, T, M: CompileTimeMachine<'mir, 'tcx, T>>(
             assert_eq!(alloc.mutability, Mutability::Mut);
         }
     }
-    // record child allocations
-    for &(_, prov) in alloc.provenance().ptrs().iter() {
-        recursive_alloc(ecx, prov);
-    }
     // link the alloc id to the actual allocation
     let alloc = ecx.tcx.mk_const_alloc(alloc);
     ecx.tcx.set_alloc_id_memory(alloc_id, alloc);
-    Ok(())
+    Ok(alloc.0.0.provenance().ptrs().iter().map(|&(_, prov)| prov))
 }
 
 /// How a constant value should be interned.
@@ -128,12 +123,16 @@ pub fn intern_const_alloc_recursive<
         }
     };
 
-    // Initialize recursive interning.
+    // Intern the base allocation, and initialize todo list for recursive interning.
     let base_alloc_id = ret.ptr().provenance.unwrap().alloc_id();
-    let mut todo = vec![(base_alloc_id, base_mutability)];
+    // First we intern the base allocation, as it requires a different mutability.
+    // This gives us the initial set of nested allocations, which will then all be processed
+    // recursively in the loop below.
+    let mut todo: Vec<_> =
+        intern_shallow(ecx, base_alloc_id, base_mutability).unwrap().map(|prov| prov).collect();
     // We need to distinguish "has just been interned" from "was already in `tcx`",
     // so we track this in a separate set.
-    let mut just_interned = FxHashSet::default();
+    let mut just_interned: FxHashSet<_> = std::iter::once(base_alloc_id).collect();
     // Whether we encountered a bad mutable pointer.
     // We want to first report "dangling" and then "mutable", so we need to delay reporting these
     // errors.
@@ -147,52 +146,56 @@ pub fn intern_const_alloc_recursive<
     // raw pointers, so we cannot rely on validation to catch them -- and since interning runs
     // before validation, and interning doesn't know the type of anything, this means we can't show
     // better errors. Maybe we should consider doing validation before interning in the future.
-    while let Some((alloc_id, mutability)) = todo.pop() {
+    while let Some(prov) = todo.pop() {
+        let alloc_id = prov.alloc_id();
+        // Crucially, we check this *before* checking whether the `alloc_id`
+        // has already been interned. The point of this check is to ensure that when
+        // there are multiple pointers to the same allocation, they are *all* immutable.
+        // Therefore it would be bad if we only checked the first pointer to any given
+        // allocation.
+        // (It is likely not possible to actually have multiple pointers to the same allocation,
+        // so alternatively we could also check that and ICE if there are multiple such pointers.)
+        if intern_kind != InternKind::Promoted
+            && inner_mutability == Mutability::Not
+            && !prov.immutable()
+        {
+            if ecx.tcx.try_get_global_alloc(alloc_id).is_some()
+                && !just_interned.contains(&alloc_id)
+            {
+                // This is a pointer to some memory from another constant. We encounter mutable
+                // pointers to such memory since we do not always track immutability through
+                // these "global" pointers. Allowing them is harmless; the point of these checks
+                // during interning is to justify why we intern the *new* allocations immutably,
+                // so we can completely ignore existing allocations. We also don't need to add
+                // this to the todo list, since after all it is already interned.
+                continue;
+            }
+            // Found a mutable pointer inside a const where inner allocations should be
+            // immutable. We exclude promoteds from this, since things like `&mut []` and
+            // `&None::<Cell<i32>>` lead to promotion that can produce mutable pointers. We rely
+            // on the promotion analysis not screwing up to ensure that it is sound to intern
+            // promoteds as immutable.
+            found_bad_mutable_pointer = true;
+        }
         if ecx.tcx.try_get_global_alloc(alloc_id).is_some() {
             // Already interned.
             debug_assert!(!ecx.memory.alloc_map.contains_key(&alloc_id));
             continue;
         }
         just_interned.insert(alloc_id);
-        intern_shallow(ecx, alloc_id, mutability, |ecx, prov| {
-            let alloc_id = prov.alloc_id();
-            if intern_kind != InternKind::Promoted
-                && inner_mutability == Mutability::Not
-                && !prov.immutable()
-            {
-                if ecx.tcx.try_get_global_alloc(alloc_id).is_some()
-                    && !just_interned.contains(&alloc_id)
-                {
-                    // This is a pointer to some memory from another constant. We encounter mutable
-                    // pointers to such memory since we do not always track immutability through
-                    // these "global" pointers. Allowing them is harmless; the point of these checks
-                    // during interning is to justify why we intern the *new* allocations immutably,
-                    // so we can completely ignore existing allocations. We also don't need to add
-                    // this to the todo list, since after all it is already interned.
-                    return;
-                }
-                // Found a mutable pointer inside a const where inner allocations should be
-                // immutable. We exclude promoteds from this, since things like `&mut []` and
-                // `&None::<Cell<i32>>` lead to promotion that can produce mutable pointers. We rely
-                // on the promotion analysis not screwing up to ensure that it is sound to intern
-                // promoteds as immutable.
-                found_bad_mutable_pointer = true;
-            }
-            // We always intern with `inner_mutability`, and furthermore we ensured above that if
-            // that is "immutable", then there are *no* mutable pointers anywhere in the newly
-            // interned memory -- justifying that we can indeed intern immutably. However this also
-            // means we can *not* easily intern immutably here if `prov.immutable()` is true and
-            // `inner_mutability` is `Mut`: there might be other pointers to that allocation, and
-            // we'd have to somehow check that they are *all* immutable before deciding that this
-            // allocation can be made immutable. In the future we could consider analyzing all
-            // pointers before deciding which allocations can be made immutable; but for now we are
-            // okay with losing some potential for immutability here. This can anyway only affect
-            // `static mut`.
-            todo.push((alloc_id, inner_mutability));
-        })
-        .map_err(|()| {
+        // We always intern with `inner_mutability`, and furthermore we ensured above that if
+        // that is "immutable", then there are *no* mutable pointers anywhere in the newly
+        // interned memory -- justifying that we can indeed intern immutably. However this also
+        // means we can *not* easily intern immutably here if `prov.immutable()` is true and
+        // `inner_mutability` is `Mut`: there might be other pointers to that allocation, and
+        // we'd have to somehow check that they are *all* immutable before deciding that this
+        // allocation can be made immutable. In the future we could consider analyzing all
+        // pointers before deciding which allocations can be made immutable; but for now we are
+        // okay with losing some potential for immutability here. This can anyway only affect
+        // `static mut`.
+        todo.extend(intern_shallow(ecx, alloc_id, inner_mutability).map_err(|()| {
             ecx.tcx.dcx().emit_err(DanglingPtrInFinal { span: ecx.tcx.span, kind: intern_kind })
-        })?;
+        })?);
     }
     if found_bad_mutable_pointer {
         return Err(ecx
@@ -220,13 +223,13 @@ pub fn intern_const_alloc_for_constprop<
         return Ok(());
     }
     // Move allocation to `tcx`.
-    intern_shallow(ecx, alloc_id, Mutability::Not, |_ecx, _| {
+    for _ in intern_shallow(ecx, alloc_id, Mutability::Not).map_err(|()| err_ub!(DeadLocal))? {
         // We are not doing recursive interning, so we don't currently support provenance.
         // (If this assertion ever triggers, we should just implement a
         // proper recursive interning loop -- or just call `intern_const_alloc_recursive`.
         panic!("`intern_const_alloc_for_constprop` called on allocation with nested provenance")
-    })
-    .map_err(|()| err_ub!(DeadLocal).into())
+    }
+    Ok(())
 }
 
 impl<'mir, 'tcx: 'mir, M: super::intern::CompileTimeMachine<'mir, 'tcx, !>>
@@ -247,15 +250,14 @@ impl<'mir, 'tcx: 'mir, M: super::intern::CompileTimeMachine<'mir, 'tcx, !>>
         let dest = self.allocate(layout, MemoryKind::Stack)?;
         f(self, &dest.clone().into())?;
         let alloc_id = dest.ptr().provenance.unwrap().alloc_id(); // this was just allocated, it must have provenance
-        intern_shallow(self, alloc_id, Mutability::Not, |ecx, prov| {
+        for prov in intern_shallow(self, alloc_id, Mutability::Not).unwrap() {
             // We are not doing recursive interning, so we don't currently support provenance.
             // (If this assertion ever triggers, we should just implement a
             // proper recursive interning loop -- or just call `intern_const_alloc_recursive`.
-            if !ecx.tcx.try_get_global_alloc(prov.alloc_id()).is_some() {
+            if !self.tcx.try_get_global_alloc(prov.alloc_id()).is_some() {
                 panic!("`intern_with_temp_alloc` with nested allocations");
             }
-        })
-        .unwrap();
+        }
         Ok(alloc_id)
     }
 }
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 5903c43ae98..519bde98820 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -24,7 +24,9 @@ use rustc_data_structures::profiling::{
     get_resident_set_size, print_time_passes_entry, TimePassesFormat,
 };
 use rustc_errors::registry::Registry;
-use rustc_errors::{markdown, ColorConfig, DiagCtxt, ErrCode, ErrorGuaranteed, PResult};
+use rustc_errors::{
+    markdown, ColorConfig, DiagCtxt, ErrCode, ErrorGuaranteed, FatalError, PResult,
+};
 use rustc_feature::find_gated_cfg;
 use rustc_interface::util::{self, collect_crate_types, get_codegen_backend};
 use rustc_interface::{interface, Queries};
@@ -1231,11 +1233,10 @@ fn parse_crate_attrs<'a>(sess: &'a Session) -> PResult<'a, ast::AttrVec> {
 /// The compiler currently unwinds with a special sentinel value to abort
 /// compilation on fatal errors. This function catches that sentinel and turns
 /// the panic into a `Result` instead.
-pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorGuaranteed> {
+pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, FatalError> {
     catch_unwind(panic::AssertUnwindSafe(f)).map_err(|value| {
         if value.is::<rustc_errors::FatalErrorMarker>() {
-            #[allow(deprecated)]
-            ErrorGuaranteed::unchecked_claim_error_was_emitted()
+            FatalError
         } else {
             panic::resume_unwind(value);
         }
@@ -1245,9 +1246,9 @@ pub fn catch_fatal_errors<F: FnOnce() -> R, R>(f: F) -> Result<R, ErrorGuarantee
 /// Variant of `catch_fatal_errors` for the `interface::Result` return type
 /// that also computes the exit code.
 pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
-    match catch_fatal_errors(f).flatten() {
-        Ok(()) => EXIT_SUCCESS,
-        Err(_) => EXIT_FAILURE,
+    match catch_fatal_errors(f) {
+        Ok(Ok(())) => EXIT_SUCCESS,
+        _ => EXIT_FAILURE,
     }
 }
 
diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
index faff7f0b526..e484bef0e0b 100644
--- a/compiler/rustc_errors/src/diagnostic_builder.rs
+++ b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -99,16 +99,20 @@ impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
     }
 
     /// `ErrorGuaranteed::emit_producing_guarantee` uses this.
-    // FIXME(eddyb) make `ErrorGuaranteed` impossible to create outside `.emit()`.
     fn emit_producing_error_guaranteed(mut self) -> ErrorGuaranteed {
         let diag = self.take_diag();
 
-        // Only allow a guarantee if the `level` wasn't switched to a
-        // non-error. The field isn't `pub`, but the whole `Diagnostic` can be
-        // overwritten with a new one, thanks to `DerefMut`.
+        // The only error levels that produce `ErrorGuaranteed` are
+        // `Error` and `DelayedBug`. But `DelayedBug` should never occur here
+        // because delayed bugs have their level changed to `Bug` when they are
+        // actually printed, so they produce an ICE.
+        //
+        // (Also, even though `level` isn't `pub`, the whole `Diagnostic` could
+        // be overwritten with a new one thanks to `DerefMut`. So this assert
+        // protects against that, too.)
         assert!(
-            diag.is_error(),
-            "emitted non-error ({:?}) diagnostic from `DiagnosticBuilder<ErrorGuaranteed>`",
+            matches!(diag.level, Level::Error | Level::DelayedBug),
+            "invalid diagnostic level ({:?})",
             diag.level,
         );
 
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index a4112d717d0..ec5029e505f 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -708,7 +708,7 @@ impl DiagCtxt {
     }
 
     /// Emit all stashed diagnostics.
-    pub fn emit_stashed_diagnostics(&self) -> Option<ErrorGuaranteed> {
+    pub fn emit_stashed_diagnostics(&self) {
         self.inner.borrow_mut().emit_stashed_diagnostics()
     }
 
@@ -931,8 +931,9 @@ impl DiagCtxt {
     /// This excludes lint errors and delayed bugs.
     pub fn has_errors(&self) -> Option<ErrorGuaranteed> {
         self.inner.borrow().has_errors().then(|| {
+            // FIXME(nnethercote) find a way to store an `ErrorGuaranteed`.
             #[allow(deprecated)]
-            ErrorGuaranteed::unchecked_claim_error_was_emitted()
+            ErrorGuaranteed::unchecked_error_guaranteed()
         })
     }
 
@@ -942,8 +943,9 @@ impl DiagCtxt {
         let inner = self.inner.borrow();
         let result = inner.has_errors() || inner.lint_err_count > 0;
         result.then(|| {
+            // FIXME(nnethercote) find a way to store an `ErrorGuaranteed`.
             #[allow(deprecated)]
-            ErrorGuaranteed::unchecked_claim_error_was_emitted()
+            ErrorGuaranteed::unchecked_error_guaranteed()
         })
     }
 
@@ -954,8 +956,9 @@ impl DiagCtxt {
         let result =
             inner.has_errors() || inner.lint_err_count > 0 || !inner.delayed_bugs.is_empty();
         result.then(|| {
+            // FIXME(nnethercote) find a way to store an `ErrorGuaranteed`.
             #[allow(deprecated)]
-            ErrorGuaranteed::unchecked_claim_error_was_emitted()
+            ErrorGuaranteed::unchecked_error_guaranteed()
         })
     }
 
@@ -1216,9 +1219,8 @@ impl DiagCtxt {
 // `DiagCtxtInner::foo`.
 impl DiagCtxtInner {
     /// Emit all stashed diagnostics.
-    fn emit_stashed_diagnostics(&mut self) -> Option<ErrorGuaranteed> {
+    fn emit_stashed_diagnostics(&mut self) {
         let has_errors = self.has_errors();
-        let mut reported = None;
         for (_, diag) in std::mem::take(&mut self.stashed_diagnostics).into_iter() {
             // Decrement the count tracking the stash; emitting will increment it.
             if diag.is_error() {
@@ -1235,12 +1237,11 @@ impl DiagCtxtInner {
                     continue;
                 }
             }
-            let reported_this = self.emit_diagnostic(diag);
-            reported = reported.or(reported_this);
+            self.emit_diagnostic(diag);
         }
-        reported
     }
 
+    // Return value is only `Some` if the level is `Error` or `DelayedBug`.
     fn emit_diagnostic(&mut self, mut diagnostic: Diagnostic) -> Option<ErrorGuaranteed> {
         assert!(diagnostic.level.can_be_top_or_sub().0);
 
@@ -1285,7 +1286,7 @@ impl DiagCtxtInner {
                 let backtrace = std::backtrace::Backtrace::capture();
                 self.delayed_bugs.push(DelayedDiagnostic::with_backtrace(diagnostic, backtrace));
                 #[allow(deprecated)]
-                return Some(ErrorGuaranteed::unchecked_claim_error_was_emitted());
+                return Some(ErrorGuaranteed::unchecked_error_guaranteed());
             }
             GoodPathDelayedBug => {
                 let backtrace = std::backtrace::Backtrace::capture();
@@ -1319,6 +1320,7 @@ impl DiagCtxtInner {
                 !self.emitted_diagnostics.insert(diagnostic_hash)
             };
 
+            let level = diagnostic.level;
             let is_error = diagnostic.is_error();
             let is_lint = diagnostic.is_lint.is_some();
 
@@ -1355,6 +1357,7 @@ impl DiagCtxtInner {
 
                 self.emitter.emit_diagnostic(diagnostic);
             }
+
             if is_error {
                 if is_lint {
                     self.lint_err_count += 1;
@@ -1362,11 +1365,11 @@ impl DiagCtxtInner {
                     self.err_count += 1;
                 }
                 self.panic_if_treat_err_as_bug();
+            }
 
-                #[allow(deprecated)]
-                {
-                    guaranteed = Some(ErrorGuaranteed::unchecked_claim_error_was_emitted());
-                }
+            #[allow(deprecated)]
+            if level == Level::Error {
+                guaranteed = Some(ErrorGuaranteed::unchecked_error_guaranteed());
             }
         });
 
diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
index 1dabb6feb5e..4860555de20 100644
--- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
@@ -344,11 +344,18 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
         kind: hir::ExprKind::Closure(hir::Closure { kind, .. }), ..
     }) = node
     {
+        // See `ClosureArgsParts`, `CoroutineArgsParts`, and `CoroutineClosureArgsParts`
+        // for info on the usage of each of these fields.
         let dummy_args = match kind {
             ClosureKind::Closure => &["<closure_kind>", "<closure_signature>", "<upvars>"][..],
-            ClosureKind::Coroutine(_) => {
-                &["<resume_ty>", "<yield_ty>", "<return_ty>", "<witness>", "<upvars>"][..]
-            }
+            ClosureKind::Coroutine(_) => &[
+                "<coroutine_kind>",
+                "<resume_ty>",
+                "<yield_ty>",
+                "<return_ty>",
+                "<witness>",
+                "<upvars>",
+            ][..],
             ClosureKind::CoroutineClosure(_) => &[
                 "<closure_kind>",
                 "<closure_signature_parts>",
diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index cf1f232229d..7ea0469dedd 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -1,7 +1,11 @@
 use crate::coercion::{AsCoercionSite, CoerceMany};
 use crate::{Diverges, Expectation, FnCtxt, Needs};
-use rustc_errors::Diagnostic;
-use rustc_hir::{self as hir, ExprKind};
+use rustc_errors::{Applicability, Diagnostic};
+use rustc_hir::{
+    self as hir,
+    def::{CtorOf, DefKind, Res},
+    ExprKind, PatKind,
+};
 use rustc_hir_pretty::ty_to_string;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::traits::Obligation;
@@ -273,7 +277,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Returns `true` if there was an error forcing the coercion to the `()` type.
     pub(super) fn if_fallback_coercion<T>(
         &self,
-        span: Span,
+        if_span: Span,
+        cond_expr: &'tcx hir::Expr<'tcx>,
         then_expr: &'tcx hir::Expr<'tcx>,
         coercion: &mut CoerceMany<'tcx, '_, T>,
     ) -> bool
@@ -283,29 +288,106 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // If this `if` expr is the parent's function return expr,
         // the cause of the type coercion is the return type, point at it. (#25228)
         let hir_id = self.tcx.hir().parent_id(self.tcx.hir().parent_id(then_expr.hir_id));
-        let ret_reason = self.maybe_get_coercion_reason(hir_id, span);
-        let cause = self.cause(span, ObligationCauseCode::IfExpressionWithNoElse);
+        let ret_reason = self.maybe_get_coercion_reason(hir_id, if_span);
+        let cause = self.cause(if_span, ObligationCauseCode::IfExpressionWithNoElse);
         let mut error = false;
         coercion.coerce_forced_unit(
             self,
             &cause,
-            |err| {
-                if let Some((span, msg)) = &ret_reason {
-                    err.span_label(*span, msg.clone());
-                } else if let ExprKind::Block(block, _) = &then_expr.kind
-                    && let Some(expr) = &block.expr
-                {
-                    err.span_label(expr.span, "found here");
-                }
-                err.note("`if` expressions without `else` evaluate to `()`");
-                err.help("consider adding an `else` block that evaluates to the expected type");
-                error = true;
-            },
+            |err| self.explain_if_expr(err, ret_reason, if_span, cond_expr, then_expr, &mut error),
             false,
         );
         error
     }
 
+    /// Explain why `if` expressions without `else` evaluate to `()` and detect likely irrefutable
+    /// `if let PAT = EXPR {}` expressions that could be turned into `let PAT = EXPR;`.
+    fn explain_if_expr(
+        &self,
+        err: &mut Diagnostic,
+        ret_reason: Option<(Span, String)>,
+        if_span: Span,
+        cond_expr: &'tcx hir::Expr<'tcx>,
+        then_expr: &'tcx hir::Expr<'tcx>,
+        error: &mut bool,
+    ) {
+        if let Some((if_span, msg)) = ret_reason {
+            err.span_label(if_span, msg.clone());
+        } else if let ExprKind::Block(block, _) = then_expr.kind
+            && let Some(expr) = block.expr
+        {
+            err.span_label(expr.span, "found here");
+        }
+        err.note("`if` expressions without `else` evaluate to `()`");
+        err.help("consider adding an `else` block that evaluates to the expected type");
+        *error = true;
+        if let ExprKind::Let(hir::Let { span, pat, init, .. }) = cond_expr.kind
+            && let ExprKind::Block(block, _) = then_expr.kind
+            // Refutability checks occur on the MIR, so we approximate it here by checking
+            // if we have an enum with a single variant or a struct in the pattern.
+            && let PatKind::TupleStruct(qpath, ..) | PatKind::Struct(qpath, ..) = pat.kind
+            && let hir::QPath::Resolved(_, path) = qpath
+        {
+            match path.res {
+                Res::Def(DefKind::Ctor(CtorOf::Struct, _), _) => {
+                    // Structs are always irrefutable. Their fields might not be, but we
+                    // don't check for that here, it's only an approximation.
+                }
+                Res::Def(DefKind::Ctor(CtorOf::Variant, _), def_id)
+                    if self
+                        .tcx
+                        .adt_def(self.tcx.parent(self.tcx.parent(def_id)))
+                        .variants()
+                        .len()
+                        == 1 =>
+                {
+                    // There's only a single variant in the `enum`, so we can suggest the
+                    // irrefutable `let` instead of `if let`.
+                }
+                _ => return,
+            }
+
+            let mut sugg = vec![
+                // Remove the `if`
+                (if_span.until(*span), String::new()),
+            ];
+            match (block.stmts, block.expr) {
+                ([first, ..], Some(expr)) => {
+                    let padding = self
+                        .tcx
+                        .sess
+                        .source_map()
+                        .indentation_before(first.span)
+                        .unwrap_or_else(|| String::new());
+                    sugg.extend([
+                        (init.span.between(first.span), format!(";\n{padding}")),
+                        (expr.span.shrink_to_hi().with_hi(block.span.hi()), String::new()),
+                    ]);
+                }
+                ([], Some(expr)) => {
+                    let padding = self
+                        .tcx
+                        .sess
+                        .source_map()
+                        .indentation_before(expr.span)
+                        .unwrap_or_else(|| String::new());
+                    sugg.extend([
+                        (init.span.between(expr.span), format!(";\n{padding}")),
+                        (expr.span.shrink_to_hi().with_hi(block.span.hi()), String::new()),
+                    ]);
+                }
+                // If there's no value in the body, then the `if` expression would already
+                // be of type `()`, so checking for those cases is unnecessary.
+                (_, None) => return,
+            }
+            err.multipart_suggestion(
+                "consider using an irrefutable `let` binding instead",
+                sugg,
+                Applicability::MaybeIncorrect,
+            );
+        }
+    }
+
     pub fn maybe_get_coercion_reason(
         &self,
         hir_id: hir::HirId,
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 1adde8c21b8..54664f38b19 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -1118,7 +1118,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // We won't diverge unless both branches do (or the condition does).
             self.diverges.set(cond_diverges | then_diverges & else_diverges);
         } else {
-            self.if_fallback_coercion(sp, then_expr, &mut coerce);
+            self.if_fallback_coercion(sp, cond_expr, then_expr, &mut coerce);
 
             // If the condition is false we can't diverge.
             self.diverges.set(cond_diverges);
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 2d4963a8b90..bfc4fc07d4c 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -749,6 +749,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(debug_macros, true);
     tracked!(default_hidden_visibility, Some(true));
     tracked!(dep_info_omit_d_target, true);
+    tracked!(direct_access_external_data, Some(true));
     tracked!(dual_proc_macros, true);
     tracked!(dwarf_version, Some(5));
     tracked!(emit_thin_lto, false);
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index ddfb2ece39f..9f1609a5595 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -30,6 +30,7 @@
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(core_intrinsics)]
+#![feature(const_type_name)]
 #![feature(discriminant_kind)]
 #![feature(exhaustive_patterns)]
 #![feature(coroutines)]
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 9475b89aa15..e22d5228628 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -140,8 +140,12 @@ fn to_profiler_name(type_name: &'static str) -> &'static str {
 /// loop that goes over each available MIR and applies `run_pass`.
 pub trait MirPass<'tcx> {
     fn name(&self) -> &'static str {
-        let name = std::any::type_name::<Self>();
-        if let Some((_, tail)) = name.rsplit_once(':') { tail } else { name }
+        // FIXME Simplify the implementation once more `str` methods get const-stable.
+        // See copypaste in `MirLint`
+        const {
+            let name = std::any::type_name::<Self>();
+            crate::util::common::c_name(name)
+        }
     }
 
     fn profiler_name(&self) -> &'static str {
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index 9c1f4b20d2c..8848d216f5b 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -765,7 +765,14 @@ fn polymorphize<'tcx>(
     let def_id = instance.def_id();
     let upvars_ty = match tcx.type_of(def_id).skip_binder().kind() {
         ty::Closure(..) => Some(args.as_closure().tupled_upvars_ty()),
-        ty::Coroutine(..) => Some(args.as_coroutine().tupled_upvars_ty()),
+        ty::Coroutine(..) => {
+            assert_eq!(
+                args.as_coroutine().kind_ty(),
+                tcx.types.unit,
+                "polymorphization does not support coroutines from async closures"
+            );
+            Some(args.as_coroutine().tupled_upvars_ty())
+        }
         _ => None,
     };
     let has_upvars = upvars_ty.is_some_and(|ty| !ty.tuple_fields().is_empty());
diff --git a/compiler/rustc_middle/src/util/common.rs b/compiler/rustc_middle/src/util/common.rs
index df101a2f6e4..dd3a36c7bf8 100644
--- a/compiler/rustc_middle/src/util/common.rs
+++ b/compiler/rustc_middle/src/util/common.rs
@@ -65,3 +65,19 @@ pub fn indenter() -> Indenter {
     debug!(">>");
     Indenter { _cannot_construct_outside_of_this_module: () }
 }
+
+// const wrapper for `if let Some((_, tail)) = name.rsplit_once(':') { tail } else { name }`
+pub const fn c_name(name: &'static str) -> &'static str {
+    // FIXME Simplify the implementation once more `str` methods get const-stable.
+    // and inline into call site
+    let bytes = name.as_bytes();
+    let mut i = bytes.len();
+    while i > 0 && bytes[i - 1] != b':' {
+        i = i - 1;
+    }
+    let (_, bytes) = bytes.split_at(i);
+    match std::str::from_utf8(bytes) {
+        Ok(name) => name,
+        Err(_) => name,
+    }
+}
diff --git a/compiler/rustc_mir_transform/src/coverage/counters.rs b/compiler/rustc_mir_transform/src/coverage/counters.rs
index 8c11dea5d4e..9a1d8bae6b4 100644
--- a/compiler/rustc_mir_transform/src/coverage/counters.rs
+++ b/compiler/rustc_mir_transform/src/coverage/counters.rs
@@ -1,4 +1,5 @@
-use rustc_data_structures::fx::FxIndexMap;
+use rustc_data_structures::captures::Captures;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::graph::WithNumNodes;
 use rustc_index::bit_set::BitSet;
 use rustc_index::IndexVec;
@@ -38,19 +39,27 @@ impl Debug for BcbCounter {
     }
 }
 
+#[derive(Debug)]
+pub(super) enum CounterIncrementSite {
+    Node { bcb: BasicCoverageBlock },
+    Edge { from_bcb: BasicCoverageBlock, to_bcb: BasicCoverageBlock },
+}
+
 /// Generates and stores coverage counter and coverage expression information
 /// associated with nodes/edges in the BCB graph.
 pub(super) struct CoverageCounters {
-    next_counter_id: CounterId,
+    /// List of places where a counter-increment statement should be injected
+    /// into MIR, each with its corresponding counter ID.
+    counter_increment_sites: IndexVec<CounterId, CounterIncrementSite>,
 
     /// Coverage counters/expressions that are associated with individual BCBs.
     bcb_counters: IndexVec<BasicCoverageBlock, Option<BcbCounter>>,
     /// Coverage counters/expressions that are associated with the control-flow
     /// edge between two BCBs.
     ///
-    /// The iteration order of this map can affect the precise contents of MIR,
-    /// so we use `FxIndexMap` to avoid query stability hazards.
-    bcb_edge_counters: FxIndexMap<(BasicCoverageBlock, BasicCoverageBlock), BcbCounter>,
+    /// We currently don't iterate over this map, but if we do in the future,
+    /// switch it back to `FxIndexMap` to avoid query stability hazards.
+    bcb_edge_counters: FxHashMap<(BasicCoverageBlock, BasicCoverageBlock), BcbCounter>,
     /// Tracks which BCBs have a counter associated with some incoming edge.
     /// Only used by assertions, to verify that BCBs with incoming edge
     /// counters do not have their own physical counters (expressions are allowed).
@@ -71,9 +80,9 @@ impl CoverageCounters {
         let num_bcbs = basic_coverage_blocks.num_nodes();
 
         let mut this = Self {
-            next_counter_id: CounterId::START,
+            counter_increment_sites: IndexVec::new(),
             bcb_counters: IndexVec::from_elem_n(None, num_bcbs),
-            bcb_edge_counters: FxIndexMap::default(),
+            bcb_edge_counters: FxHashMap::default(),
             bcb_has_incoming_edge_counters: BitSet::new_empty(num_bcbs),
             expressions: IndexVec::new(),
         };
@@ -84,8 +93,8 @@ impl CoverageCounters {
         this
     }
 
-    fn make_counter(&mut self) -> BcbCounter {
-        let id = self.next_counter();
+    fn make_counter(&mut self, site: CounterIncrementSite) -> BcbCounter {
+        let id = self.counter_increment_sites.push(site);
         BcbCounter::Counter { id }
     }
 
@@ -103,15 +112,8 @@ impl CoverageCounters {
         self.make_expression(lhs, Op::Add, rhs)
     }
 
-    /// Counter IDs start from one and go up.
-    fn next_counter(&mut self) -> CounterId {
-        let next = self.next_counter_id;
-        self.next_counter_id = self.next_counter_id + 1;
-        next
-    }
-
     pub(super) fn num_counters(&self) -> usize {
-        self.next_counter_id.as_usize()
+        self.counter_increment_sites.len()
     }
 
     #[cfg(test)]
@@ -171,22 +173,26 @@ impl CoverageCounters {
         self.bcb_counters[bcb]
     }
 
-    pub(super) fn bcb_node_counters(
+    /// Returns an iterator over all the nodes/edges in the coverage graph that
+    /// should have a counter-increment statement injected into MIR, along with
+    /// each site's corresponding counter ID.
+    pub(super) fn counter_increment_sites(
         &self,
-    ) -> impl Iterator<Item = (BasicCoverageBlock, &BcbCounter)> {
-        self.bcb_counters
-            .iter_enumerated()
-            .filter_map(|(bcb, counter_kind)| Some((bcb, counter_kind.as_ref()?)))
+    ) -> impl Iterator<Item = (CounterId, &CounterIncrementSite)> {
+        self.counter_increment_sites.iter_enumerated()
     }
 
-    /// For each edge in the BCB graph that has an associated counter, yields
-    /// that edge's *from* and *to* nodes, and its counter.
-    pub(super) fn bcb_edge_counters(
+    /// Returns an iterator over the subset of BCB nodes that have been associated
+    /// with a counter *expression*, along with the ID of that expression.
+    pub(super) fn bcb_nodes_with_coverage_expressions(
         &self,
-    ) -> impl Iterator<Item = (BasicCoverageBlock, BasicCoverageBlock, &BcbCounter)> {
-        self.bcb_edge_counters
-            .iter()
-            .map(|(&(from_bcb, to_bcb), counter_kind)| (from_bcb, to_bcb, counter_kind))
+    ) -> impl Iterator<Item = (BasicCoverageBlock, ExpressionId)> + Captures<'_> {
+        self.bcb_counters.iter_enumerated().filter_map(|(bcb, &counter_kind)| match counter_kind {
+            // Yield the BCB along with its associated expression ID.
+            Some(BcbCounter::Expression { id }) => Some((bcb, id)),
+            // This BCB is associated with a counter or nothing, so skip it.
+            Some(BcbCounter::Counter { .. }) | None => None,
+        })
     }
 
     pub(super) fn into_expressions(self) -> IndexVec<ExpressionId, Expression> {
@@ -339,7 +345,8 @@ impl<'a> MakeBcbCounters<'a> {
         // program results in a tight infinite loop, but it should still compile.
         let one_path_to_target = !self.basic_coverage_blocks.bcb_has_multiple_in_edges(bcb);
         if one_path_to_target || self.bcb_predecessors(bcb).contains(&bcb) {
-            let counter_kind = self.coverage_counters.make_counter();
+            let counter_kind =
+                self.coverage_counters.make_counter(CounterIncrementSite::Node { bcb });
             if one_path_to_target {
                 debug!("{bcb:?} gets a new counter: {counter_kind:?}");
             } else {
@@ -401,7 +408,8 @@ impl<'a> MakeBcbCounters<'a> {
         }
 
         // Make a new counter to count this edge.
-        let counter_kind = self.coverage_counters.make_counter();
+        let counter_kind =
+            self.coverage_counters.make_counter(CounterIncrementSite::Edge { from_bcb, to_bcb });
         debug!("Edge {from_bcb:?}->{to_bcb:?} gets a new counter: {counter_kind:?}");
         self.coverage_counters.set_bcb_edge_counter(from_bcb, to_bcb, counter_kind)
     }
diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs
index 3aa41250fd3..4c5be0a3f4b 100644
--- a/compiler/rustc_mir_transform/src/coverage/mod.rs
+++ b/compiler/rustc_mir_transform/src/coverage/mod.rs
@@ -7,7 +7,7 @@ mod spans;
 #[cfg(test)]
 mod tests;
 
-use self::counters::{BcbCounter, CoverageCounters};
+use self::counters::{CounterIncrementSite, CoverageCounters};
 use self::graph::{BasicCoverageBlock, CoverageGraph};
 use self::spans::{BcbMapping, BcbMappingKind, CoverageSpans};
 
@@ -155,61 +155,52 @@ fn inject_coverage_statements<'tcx>(
     bcb_has_coverage_spans: impl Fn(BasicCoverageBlock) -> bool,
     coverage_counters: &CoverageCounters,
 ) {
-    // Process the counters associated with BCB nodes.
-    for (bcb, counter_kind) in coverage_counters.bcb_node_counters() {
-        let do_inject = match counter_kind {
-            // Counter-increment statements always need to be injected.
-            BcbCounter::Counter { .. } => true,
-            // The only purpose of expression-used statements is to detect
-            // when a mapping is unreachable, so we only inject them for
-            // expressions with one or more mappings.
-            BcbCounter::Expression { .. } => bcb_has_coverage_spans(bcb),
-        };
-        if do_inject {
-            inject_statement(
-                mir_body,
-                make_mir_coverage_kind(counter_kind),
-                basic_coverage_blocks[bcb].leader_bb(),
-            );
-        }
-    }
-
-    // Process the counters associated with BCB edges.
-    for (from_bcb, to_bcb, counter_kind) in coverage_counters.bcb_edge_counters() {
-        let do_inject = match counter_kind {
-            // Counter-increment statements always need to be injected.
-            BcbCounter::Counter { .. } => true,
-            // BCB-edge expressions never have mappings, so they never need
-            // a corresponding statement.
-            BcbCounter::Expression { .. } => false,
+    // Inject counter-increment statements into MIR.
+    for (id, counter_increment_site) in coverage_counters.counter_increment_sites() {
+        // Determine the block to inject a counter-increment statement into.
+        // For BCB nodes this is just their first block, but for edges we need
+        // to create a new block between the two BCBs, and inject into that.
+        let target_bb = match *counter_increment_site {
+            CounterIncrementSite::Node { bcb } => basic_coverage_blocks[bcb].leader_bb(),
+            CounterIncrementSite::Edge { from_bcb, to_bcb } => {
+                // Create a new block between the last block of `from_bcb` and
+                // the first block of `to_bcb`.
+                let from_bb = basic_coverage_blocks[from_bcb].last_bb();
+                let to_bb = basic_coverage_blocks[to_bcb].leader_bb();
+
+                let new_bb = inject_edge_counter_basic_block(mir_body, from_bb, to_bb);
+                debug!(
+                    "Edge {from_bcb:?} (last {from_bb:?}) -> {to_bcb:?} (leader {to_bb:?}) \
+                    requires a new MIR BasicBlock {new_bb:?} for counter increment {id:?}",
+                );
+                new_bb
+            }
         };
-        if !do_inject {
-            continue;
-        }
-
-        // We need to inject a coverage statement into a new BB between the
-        // last BB of `from_bcb` and the first BB of `to_bcb`.
-        let from_bb = basic_coverage_blocks[from_bcb].last_bb();
-        let to_bb = basic_coverage_blocks[to_bcb].leader_bb();
 
-        let new_bb = inject_edge_counter_basic_block(mir_body, from_bb, to_bb);
-        debug!(
-            "Edge {from_bcb:?} (last {from_bb:?}) -> {to_bcb:?} (leader {to_bb:?}) \
-                requires a new MIR BasicBlock {new_bb:?} for edge counter {counter_kind:?}",
-        );
-
-        // Inject a counter into the newly-created BB.
-        inject_statement(mir_body, make_mir_coverage_kind(counter_kind), new_bb);
+        inject_statement(mir_body, CoverageKind::CounterIncrement { id }, target_bb);
     }
-}
 
-fn make_mir_coverage_kind(counter_kind: &BcbCounter) -> CoverageKind {
-    match *counter_kind {
-        BcbCounter::Counter { id } => CoverageKind::CounterIncrement { id },
-        BcbCounter::Expression { id } => CoverageKind::ExpressionUsed { id },
+    // For each counter expression that is directly associated with at least one
+    // span, we inject an "expression-used" statement, so that coverage codegen
+    // can check whether the injected statement survived MIR optimization.
+    // (BCB edges can't have spans, so we only need to process BCB nodes here.)
+    //
+    // See the code in `rustc_codegen_llvm::coverageinfo::map_data` that deals
+    // with "expressions seen" and "zero terms".
+    for (bcb, expression_id) in coverage_counters
+        .bcb_nodes_with_coverage_expressions()
+        .filter(|&(bcb, _)| bcb_has_coverage_spans(bcb))
+    {
+        inject_statement(
+            mir_body,
+            CoverageKind::ExpressionUsed { id: expression_id },
+            basic_coverage_blocks[bcb].leader_bb(),
+        );
     }
 }
 
+/// Given two basic blocks that have a control-flow edge between them, creates
+/// and returns a new block that sits between those blocks.
 fn inject_edge_counter_basic_block(
     mir_body: &mut mir::Body<'_>,
     from_bb: BasicBlock,
diff --git a/compiler/rustc_mir_transform/src/pass_manager.rs b/compiler/rustc_mir_transform/src/pass_manager.rs
index 605e1ad46d7..77478cc741d 100644
--- a/compiler/rustc_mir_transform/src/pass_manager.rs
+++ b/compiler/rustc_mir_transform/src/pass_manager.rs
@@ -8,18 +8,10 @@ use crate::{lint::lint_body, validate, MirPass};
 pub trait MirLint<'tcx> {
     fn name(&self) -> &'static str {
         // FIXME Simplify the implementation once more `str` methods get const-stable.
+        // See copypaste in `MirPass`
         const {
             let name = std::any::type_name::<Self>();
-            let bytes = name.as_bytes();
-            let mut i = bytes.len();
-            while i > 0 && bytes[i - 1] != b':' {
-                i = i - 1;
-            }
-            let (_, bytes) = bytes.split_at(i);
-            match std::str::from_utf8(bytes) {
-                Ok(name) => name,
-                Err(_) => name,
-            }
+            rustc_middle::util::common::c_name(name)
         }
     }
 
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index 6a499a98681..61c953bcb59 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -1732,7 +1732,7 @@ pub struct UnusedVariableTryPrefix {
 
 #[derive(Subdiagnostic)]
 pub enum UnusedVariableSugg {
-    #[multipart_suggestion(passes_suggestion, applicability = "machine-applicable")]
+    #[multipart_suggestion(passes_suggestion, applicability = "maybe-incorrect")]
     TryPrefixSugg {
         #[suggestion_part(code = "_{name}")]
         spans: Vec<Span>,
@@ -1771,7 +1771,7 @@ pub struct UnusedVarTryIgnore {
 }
 
 #[derive(Subdiagnostic)]
-#[multipart_suggestion(passes_suggestion, applicability = "machine-applicable")]
+#[multipart_suggestion(passes_suggestion, applicability = "maybe-incorrect")]
 pub struct UnusedVarTryIgnoreSugg {
     #[suggestion_part(code = "{name}: _")]
     pub shorthands: Vec<Span>,
diff --git a/compiler/rustc_pattern_analysis/src/usefulness.rs b/compiler/rustc_pattern_analysis/src/usefulness.rs
index 33df4ebea43..576005b2c7f 100644
--- a/compiler/rustc_pattern_analysis/src/usefulness.rs
+++ b/compiler/rustc_pattern_analysis/src/usefulness.rs
@@ -767,12 +767,6 @@ impl<'a, Cx: TypeCx> PlaceCtxt<'a, Cx> {
     fn ctor_arity(&self, ctor: &Constructor<Cx>) -> usize {
         self.cx.ctor_arity(ctor, self.ty)
     }
-    fn ctor_sub_tys(
-        &'a self,
-        ctor: &'a Constructor<Cx>,
-    ) -> impl Iterator<Item = Cx::Ty> + ExactSizeIterator + Captures<'a> {
-        self.cx.ctor_sub_tys(ctor, self.ty)
-    }
     fn ctors_for_ty(&self) -> Result<ConstructorSet<Cx>, Cx::Error> {
         self.cx.ctors_for_ty(self.ty)
     }
@@ -828,6 +822,38 @@ impl fmt::Display for ValidityConstraint {
     }
 }
 
+/// Data about a place under investigation.
+struct PlaceInfo<Cx: TypeCx> {
+    /// The type of the place.
+    ty: Cx::Ty,
+    /// Whether the place is known to contain valid data.
+    validity: ValidityConstraint,
+    /// Whether the place is the scrutinee itself or a subplace of it.
+    is_scrutinee: bool,
+}
+
+impl<Cx: TypeCx> PlaceInfo<Cx> {
+    fn specialize<'a>(
+        &'a self,
+        cx: &'a Cx,
+        ctor: &'a Constructor<Cx>,
+    ) -> impl Iterator<Item = Self> + ExactSizeIterator + Captures<'a> {
+        let ctor_sub_tys = cx.ctor_sub_tys(ctor, &self.ty);
+        let ctor_sub_validity = self.validity.specialize(ctor);
+        ctor_sub_tys.map(move |ty| PlaceInfo {
+            ty,
+            validity: ctor_sub_validity,
+            is_scrutinee: false,
+        })
+    }
+}
+
+impl<Cx: TypeCx> Clone for PlaceInfo<Cx> {
+    fn clone(&self) -> Self {
+        Self { ty: self.ty.clone(), validity: self.validity, is_scrutinee: self.is_scrutinee }
+    }
+}
+
 /// Represents a pattern-tuple under investigation.
 // The three lifetimes are:
 // - 'p coming from the input
@@ -1001,10 +1027,9 @@ struct Matrix<'p, Cx: TypeCx> {
     /// each column must have the same type. Each column corresponds to a place within the
     /// scrutinee.
     rows: Vec<MatrixRow<'p, Cx>>,
-    /// Track the type of each column/place.
-    place_ty: SmallVec<[Cx::Ty; 2]>,
-    /// Track for each column/place whether it contains a known valid value.
-    place_validity: SmallVec<[ValidityConstraint; 2]>,
+    /// Track info about each place. Each place corresponds to a column in `rows`, and their types
+    /// must match.
+    place_info: SmallVec<[PlaceInfo<Cx>; 2]>,
     /// Track whether the virtual wildcard row used to compute exhaustiveness is relevant. See top
     /// of the file for details on relevancy.
     wildcard_row_is_relevant: bool,
@@ -1032,10 +1057,10 @@ impl<'p, Cx: TypeCx> Matrix<'p, Cx> {
         scrut_ty: Cx::Ty,
         scrut_validity: ValidityConstraint,
     ) -> Self {
+        let place_info = PlaceInfo { ty: scrut_ty, validity: scrut_validity, is_scrutinee: true };
         let mut matrix = Matrix {
             rows: Vec::with_capacity(arms.len()),
-            place_ty: smallvec![scrut_ty],
-            place_validity: smallvec![scrut_validity],
+            place_info: smallvec![place_info],
             wildcard_row_is_relevant: true,
         };
         for (row_id, arm) in arms.iter().enumerate() {
@@ -1051,11 +1076,11 @@ impl<'p, Cx: TypeCx> Matrix<'p, Cx> {
         matrix
     }
 
-    fn head_ty(&self) -> Option<&Cx::Ty> {
-        self.place_ty.first()
+    fn head_place(&self) -> Option<&PlaceInfo<Cx>> {
+        self.place_info.first()
     }
     fn column_count(&self) -> usize {
-        self.place_ty.len()
+        self.place_info.len()
     }
 
     fn rows(
@@ -1083,18 +1108,13 @@ impl<'p, Cx: TypeCx> Matrix<'p, Cx> {
         ctor: &Constructor<Cx>,
         ctor_is_relevant: bool,
     ) -> Result<Matrix<'p, Cx>, Cx::Error> {
-        let ctor_sub_tys = pcx.ctor_sub_tys(ctor);
-        let arity = ctor_sub_tys.len();
-        let specialized_place_ty = ctor_sub_tys.chain(self.place_ty[1..].iter().cloned()).collect();
-        let ctor_sub_validity = self.place_validity[0].specialize(ctor);
-        let specialized_place_validity = std::iter::repeat(ctor_sub_validity)
-            .take(arity)
-            .chain(self.place_validity[1..].iter().copied())
-            .collect();
+        let subfield_place_info = self.place_info[0].specialize(pcx.cx, ctor);
+        let arity = subfield_place_info.len();
+        let specialized_place_info =
+            subfield_place_info.chain(self.place_info[1..].iter().cloned()).collect();
         let mut matrix = Matrix {
             rows: Vec::new(),
-            place_ty: specialized_place_ty,
-            place_validity: specialized_place_validity,
+            place_info: specialized_place_info,
             wildcard_row_is_relevant: self.wildcard_row_is_relevant && ctor_is_relevant,
         };
         for (i, row) in self.rows().enumerate() {
@@ -1127,11 +1147,11 @@ impl<'p, Cx: TypeCx> fmt::Debug for Matrix<'p, Cx> {
             .map(|row| row.iter().map(|pat| format!("{pat:?}")).collect())
             .collect();
         pretty_printed_matrix
-            .push(self.place_validity.iter().map(|validity| format!("{validity}")).collect());
+            .push(self.place_info.iter().map(|place| format!("{}", place.validity)).collect());
 
         let column_count = self.column_count();
         assert!(self.rows.iter().all(|row| row.len() == column_count));
-        assert!(self.place_validity.len() == column_count);
+        assert!(self.place_info.len() == column_count);
         let column_widths: Vec<usize> = (0..column_count)
             .map(|col| pretty_printed_matrix.iter().map(|row| row[col].len()).max().unwrap_or(0))
             .collect();
@@ -1432,11 +1452,10 @@ fn collect_overlapping_range_endpoints<'p, Cx: TypeCx>(
 /// - unspecialization, where we lift the results from the previous step into results for this step
 ///     (using `apply_constructor` and by updating `row.useful` for each parent row).
 /// This is all explained at the top of the file.
-#[instrument(level = "debug", skip(mcx, is_top_level), ret)]
+#[instrument(level = "debug", skip(mcx), ret)]
 fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
     mcx: UsefulnessCtxt<'a, Cx>,
     matrix: &mut Matrix<'p, Cx>,
-    is_top_level: bool,
 ) -> Result<WitnessMatrix<Cx>, Cx::Error> {
     debug_assert!(matrix.rows().all(|r| r.len() == matrix.column_count()));
 
@@ -1447,7 +1466,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
         return Ok(WitnessMatrix::empty());
     }
 
-    let Some(ty) = matrix.head_ty().cloned() else {
+    let Some(place) = matrix.head_place() else {
         // The base case: there are no columns in the matrix. We are morally pattern-matching on ().
         // A row is useful iff it has no (unguarded) rows above it.
         let mut useful = true; // Whether the next row is useful.
@@ -1467,18 +1486,17 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
         };
     };
 
-    debug!("ty: {ty:?}");
-    let pcx = &PlaceCtxt { cx: mcx.tycx, ty: &ty };
+    let ty = &place.ty.clone(); // Clone it out so we can mutate `matrix` later.
+    let pcx = &PlaceCtxt { cx: mcx.tycx, ty };
+    debug!("ty: {:?}", pcx.ty);
     let ctors_for_ty = pcx.ctors_for_ty()?;
 
-    // Whether the place/column we are inspecting is known to contain valid data.
-    let place_validity = matrix.place_validity[0];
     // We treat match scrutinees of type `!` or `EmptyEnum` differently.
     let is_toplevel_exception =
-        is_top_level && matches!(ctors_for_ty, ConstructorSet::NoConstructors);
+        place.is_scrutinee && matches!(ctors_for_ty, ConstructorSet::NoConstructors);
     // Whether empty patterns are counted as useful or not. We only warn an empty arm unreachable if
     // it is guaranteed unreachable by the opsem (i.e. if the place is `known_valid`).
-    let empty_arms_are_unreachable = place_validity.is_known_valid()
+    let empty_arms_are_unreachable = place.validity.is_known_valid()
         && (is_toplevel_exception
             || mcx.tycx.is_exhaustive_patterns_feature_on()
             || mcx.tycx.is_min_exhaustive_patterns_feature_on());
@@ -1504,7 +1522,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
 
     // Decide what constructors to report.
     let is_integers = matches!(ctors_for_ty, ConstructorSet::Integers { .. });
-    let always_report_all = is_top_level && !is_integers;
+    let always_report_all = place.is_scrutinee && !is_integers;
     // Whether we should report "Enum::A and Enum::C are missing" or "_ is missing".
     let report_individual_missing_ctors = always_report_all || !all_missing;
     // Which constructors are considered missing. We ensure that `!missing_ctors.is_empty() =>
@@ -1525,7 +1543,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
         let ctor_is_relevant = matches!(ctor, Constructor::Missing) || missing_ctors.is_empty();
         let mut spec_matrix = matrix.specialize_constructor(pcx, &ctor, ctor_is_relevant)?;
         let mut witnesses = ensure_sufficient_stack(|| {
-            compute_exhaustiveness_and_usefulness(mcx, &mut spec_matrix, false)
+            compute_exhaustiveness_and_usefulness(mcx, &mut spec_matrix)
         })?;
 
         // Transform witnesses for `spec_matrix` into witnesses for `matrix`.
@@ -1600,8 +1618,7 @@ pub fn compute_match_usefulness<'p, Cx: TypeCx>(
 ) -> Result<UsefulnessReport<'p, Cx>, Cx::Error> {
     let cx = UsefulnessCtxt { tycx };
     let mut matrix = Matrix::new(arms, scrut_ty, scrut_validity);
-    let non_exhaustiveness_witnesses =
-        compute_exhaustiveness_and_usefulness(cx, &mut matrix, true)?;
+    let non_exhaustiveness_witnesses = compute_exhaustiveness_and_usefulness(cx, &mut matrix)?;
 
     let non_exhaustiveness_witnesses: Vec<_> = non_exhaustiveness_witnesses.single_column();
     let arm_usefulness: Vec<_> = arms
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index d8d201d5f24..ea93ac5841f 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1572,6 +1572,8 @@ options! {
     dep_info_omit_d_target: bool = (false, parse_bool, [TRACKED],
         "in dep-info output, omit targets for tracking dependencies of the dep-info files \
         themselves (default: no)"),
+    direct_access_external_data: Option<bool> = (None, parse_opt_bool, [TRACKED],
+        "Direct or use GOT indirect to reference external data symbols"),
     dual_proc_macros: bool = (false, parse_bool, [TRACKED],
         "load proc macros for both target and host, but only link to the target (default: no)"),
     dump_dep_graph: bool = (false, parse_bool, [UNTRACKED],
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index f6af5a4f87e..0c084660761 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -315,7 +315,7 @@ impl Session {
     pub fn compile_status(&self) -> Result<(), ErrorGuaranteed> {
         // We must include lint errors here.
         if let Some(reported) = self.dcx().has_errors_or_lint_errors() {
-            let _ = self.dcx().emit_stashed_diagnostics();
+            self.dcx().emit_stashed_diagnostics();
             Err(reported)
         } else {
             Ok(())
@@ -767,6 +767,13 @@ impl Session {
         self.opts.unstable_opts.tls_model.unwrap_or(self.target.tls_model)
     }
 
+    pub fn direct_access_external_data(&self) -> Option<bool> {
+        self.opts
+            .unstable_opts
+            .direct_access_external_data
+            .or(self.target.direct_access_external_data)
+    }
+
     pub fn split_debuginfo(&self) -> SplitDebuginfo {
         self.opts.cg.split_debuginfo.unwrap_or(self.target.split_debuginfo)
     }
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index ea6766ea583..bcf04a71ae2 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -2477,10 +2477,9 @@ where
 pub struct ErrorGuaranteed(());
 
 impl ErrorGuaranteed {
-    /// To be used only if you really know what you are doing... ideally, we would find a way to
-    /// eliminate all calls to this method.
-    #[deprecated = "`Session::span_delayed_bug` should be preferred over this function"]
-    pub fn unchecked_claim_error_was_emitted() -> Self {
+    /// Don't use this outside of `DiagCtxtInner::emit_diagnostic`!
+    #[deprecated = "should only be used in `DiagCtxtInner::emit_diagnostic`"]
+    pub fn unchecked_error_guaranteed() -> Self {
         ErrorGuaranteed(())
     }
 }
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 6c698c5b01d..d04bcb2d78a 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -1543,6 +1543,7 @@ supported_targets! {
     ("armebv7r-none-eabihf", armebv7r_none_eabihf),
     ("armv7r-none-eabi", armv7r_none_eabi),
     ("armv7r-none-eabihf", armv7r_none_eabihf),
+    ("armv8r-none-eabihf", armv8r_none_eabihf),
 
     ("x86_64-pc-solaris", x86_64_pc_solaris),
     ("sparcv9-sun-solaris", sparcv9_sun_solaris),
@@ -1886,6 +1887,8 @@ pub struct TargetOptions {
     /// passed, and cannot be disabled even via `-C`. Corresponds to `llc
     /// -mattr=$features`.
     pub features: StaticCow<str>,
+    /// Direct or use GOT indirect to reference external data symbols
+    pub direct_access_external_data: Option<bool>,
     /// Whether dynamic linking is available on this target. Defaults to false.
     pub dynamic_linking: bool,
     /// Whether dynamic linking can export TLS globals. Defaults to true.
@@ -2280,6 +2283,7 @@ impl Default for TargetOptions {
             asm_args: cvs![],
             cpu: "generic".into(),
             features: "".into(),
+            direct_access_external_data: None,
             dynamic_linking: false,
             dll_tls_export: true,
             only_cdylib: false,
@@ -2579,6 +2583,12 @@ impl Target {
                     base.$key_name = s as u32;
                 }
             } );
+            ($key_name:ident, Option<bool>) => ( {
+                let name = (stringify!($key_name)).replace("_", "-");
+                if let Some(s) = obj.remove(&name).and_then(|b| b.as_bool()) {
+                    base.$key_name = Some(s);
+                }
+            } );
             ($key_name:ident, Option<u64>) => ( {
                 let name = (stringify!($key_name)).replace("_", "-");
                 if let Some(s) = obj.remove(&name).and_then(|b| b.as_u64()) {
@@ -3007,6 +3017,7 @@ impl Target {
         key!(cpu);
         key!(features);
         key!(dynamic_linking, bool);
+        key!(direct_access_external_data, Option<bool>);
         key!(dll_tls_export, bool);
         key!(only_cdylib, bool);
         key!(executables, bool);
@@ -3261,6 +3272,7 @@ impl ToJson for Target {
         target_option_val!(cpu);
         target_option_val!(features);
         target_option_val!(dynamic_linking);
+        target_option_val!(direct_access_external_data);
         target_option_val!(dll_tls_export);
         target_option_val!(only_cdylib);
         target_option_val!(executables);
diff --git a/compiler/rustc_target/src/spec/targets/armv8r_none_eabihf.rs b/compiler/rustc_target/src/spec/targets/armv8r_none_eabihf.rs
new file mode 100644
index 00000000000..28dba4f7f5d
--- /dev/null
+++ b/compiler/rustc_target/src/spec/targets/armv8r_none_eabihf.rs
@@ -0,0 +1,35 @@
+// Targets the Little-endian Cortex-R52 processor (ARMv8-R)
+
+use crate::spec::{Cc, LinkerFlavor, Lld, PanicStrategy, RelocModel, Target, TargetOptions};
+
+pub fn target() -> Target {
+    Target {
+        llvm_target: "armv8r-none-eabihf".into(),
+        pointer_width: 32,
+        data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
+        arch: "arm".into(),
+
+        options: TargetOptions {
+            abi: "eabihf".into(),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            linker: Some("rust-lld".into()),
+            relocation_model: RelocModel::Static,
+            panic_strategy: PanicStrategy::Abort,
+            // The Cortex-R52 has two variants with respect to floating-point support:
+            // 1. fp-armv8, SP-only, with 16 DP (32 SP) registers
+            // 2. neon-fp-armv8, SP+DP, with 32 DP registers
+            // Use the lesser of these two options as the default, as it will produce code
+            // compatible with either variant.
+            //
+            // Reference:
+            // Arm Cortex-R52 Processor Technical Reference Manual
+            // - Chapter 15 Advanced SIMD and floating-point support
+            features: "+fp-armv8,-fp64,-d32".into(),
+            max_atomic_width: Some(64),
+            emit_debug_gdb_scripts: false,
+            // GCC defaults to 8 for arm-none here.
+            c_enum_min_bits: Some(8),
+            ..Default::default()
+        },
+    }
+}
diff --git a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs
index cb24e740c86..f4350708986 100644
--- a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs
@@ -12,6 +12,7 @@ pub fn target() -> Target {
             features: "+f,+d".into(),
             llvm_abiname: "lp64d".into(),
             max_atomic_width: Some(64),
+            direct_access_external_data: Some(false),
             ..base::linux_gnu::opts()
         },
     }
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh b/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
index cc0c658aabd..f5c426a717f 100755
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
@@ -30,7 +30,7 @@ python3 "$X_PY" test --stage 2 src/tools/rustfmt
 # We set the GC interval to the shortest possible value (0 would be off) to increase the chance
 # that bugs which only surface when the GC runs at a specific time are more likely to cause CI to fail.
 # This significantly increases the runtime of our test suite, or we'd do this in PR CI too.
-if [[ -z "${PR_CI_JOB:-}" ]]; then
+if [ -z "${PR_CI_JOB:-}" ]; then
     MIRIFLAGS=-Zmiri-provenance-gc=1 python3 "$X_PY" test --stage 2 src/tools/miri
 else
     python3 "$X_PY" test --stage 2 src/tools/miri
diff --git a/src/doc/rustc/src/SUMMARY.md b/src/doc/rustc/src/SUMMARY.md
index 1998b008dc8..1f9307203bc 100644
--- a/src/doc/rustc/src/SUMMARY.md
+++ b/src/doc/rustc/src/SUMMARY.md
@@ -26,6 +26,7 @@
     - [armv4t-none-eabi](platform-support/armv4t-none-eabi.md)
     - [armv5te-none-eabi](platform-support/armv5te-none-eabi.md)
     - [armv7r-none-eabi](platform-support/armv7r-none-eabi.md)
+    - [armv8r-none-eabihf](platform-support/armv8r-none-eabihf.md)
     - [armv6k-nintendo-3ds](platform-support/armv6k-nintendo-3ds.md)
     - [armv7-sony-vita-newlibeabihf](platform-support/armv7-sony-vita-newlibeabihf.md)
     - [armv7-unknown-linux-uclibceabi](platform-support/armv7-unknown-linux-uclibceabi.md)
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index f648a60b6c4..80d9dc85f16 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -280,6 +280,7 @@ target | std | host | notes
 [`armv7a-none-eabihf`](platform-support/arm-none-eabi.md) | * |  | Bare ARMv7-A, hardfloat
 [`armv7k-apple-watchos`](platform-support/apple-watchos.md) | ✓ |  | ARMv7-A Apple WatchOS
 `armv7s-apple-ios` | ✓ |  | ARMv7-A Apple-A6 Apple iOS
+[`armv8r-none-eabihf`](platform-support/armv8r-none-eabihf.md) | * |  | Bare ARMv8-R, hardfloat
 `avr-unknown-gnu-atmega328` | * |  | AVR. Requires `-Z build-std=core`
 `bpfeb-unknown-none` | * |  | BPF (big endian)
 `bpfel-unknown-none` | * |  | BPF (little endian)
diff --git a/src/doc/rustc/src/platform-support/arm-none-eabi.md b/src/doc/rustc/src/platform-support/arm-none-eabi.md
index 4f76d0d7bbc..6335a6405a1 100644
--- a/src/doc/rustc/src/platform-support/arm-none-eabi.md
+++ b/src/doc/rustc/src/platform-support/arm-none-eabi.md
@@ -13,6 +13,7 @@
 - [{arm,thumb}v4t-none-eabi](armv4t-none-eabi.md)
 - [{arm,thumb}v5te-none-eabi](armv5te-none-eabi.md)
 - armv7a-none-eabihf
+- [armv8r-none-eabihf](armv8r-none-eabihf.md)
 
 Bare-metal target for 32-bit ARM CPUs.
 
diff --git a/src/doc/rustc/src/platform-support/armv8r-none-eabihf.md b/src/doc/rustc/src/platform-support/armv8r-none-eabihf.md
new file mode 100644
index 00000000000..588e5d7c994
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/armv8r-none-eabihf.md
@@ -0,0 +1,40 @@
+# `armv8r-none-eabihf`
+
+**Tier: 3**
+
+Bare-metal target for CPUs in the ARMv8-R architecture family, supporting
+dual ARM/Thumb mode, with ARM mode as the default.
+
+Processors in this family include the Arm [Cortex-R52][cortex-r52]
+and [Cortex-R52+][cortex-r52-plus].
+
+See [`arm-none-eabi`](arm-none-eabi.md) for information applicable to all
+`arm-none-eabi` targets.
+
+[cortex-r52]: https://www.arm.com/products/silicon-ip-cpu/cortex-r/cortex-r52
+[cortex-r52-plus]: https://www.arm.com/products/silicon-ip-cpu/cortex-r/cortex-r52-plus
+
+## Target maintainers
+
+- [Chris Copeland](https://github.com/chrisnc), `chris@chrisnc.net`
+
+## Requirements
+
+The Cortex-R52 family always includes a floating-point unit, so there is no
+non-`hf` version of this target. The floating-point features assumed by this
+target are those of the single-precision-only config of the Cortex-R52, which
+has 16 double-precision registers, accessible as 32 single-precision registers.
+The other variant of Cortex-R52 includes double-precision, 32 double-precision
+registers, and Advanced SIMD (Neon).
+
+The manual refers to this as the "Full Advanced SIMD config". To compile code
+for this variant, use: `-C target-feature=+fp64,+d32,+neon`. See the [Advanced
+SIMD and floating-point support][fpu] section of the Cortex-R52 Processor
+Technical Reference Manual for more details.
+
+[fpu]: https://developer.arm.com/documentation/100026/0104/Advanced-SIMD-and-floating-point-support/About-the-Advanced-SIMD-and-floating-point-support
+
+## Cross-compilation toolchains and C code
+
+This target supports C code compiled with the `arm-none-eabi` target triple and
+`-march=armv8-r` or a suitable `-mcpu` flag.
diff --git a/src/doc/unstable-book/src/compiler-flags/direct-access-external-data.md b/src/doc/unstable-book/src/compiler-flags/direct-access-external-data.md
new file mode 100644
index 00000000000..c72df437960
--- /dev/null
+++ b/src/doc/unstable-book/src/compiler-flags/direct-access-external-data.md
@@ -0,0 +1,16 @@
+# `direct_access_external_data`
+
+The tracking issue for this feature is: https://github.com/rust-lang/compiler-team/issues/707
+
+------------------------
+
+Option `-Z direct-access-external-data` controls how to access symbols of
+external data.
+
+Supported values for this option are:
+
+- `yes` - Don't use GOT indirection to reference external data symbols.
+- `no` - Use GOT indirection to reference external data symbols.
+
+If the option is not explicitly specified, different targets have different
+default values.
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index 3f7f9270b2d..c46047aa0db 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -323,20 +323,20 @@ impl Options {
         early_dcx: &mut EarlyDiagCtxt,
         matches: &getopts::Matches,
         args: Vec<String>,
-    ) -> Result<(Options, RenderOptions), i32> {
+    ) -> Option<(Options, RenderOptions)> {
         // Check for unstable options.
         nightly_options::check_nightly_options(early_dcx, matches, &opts());
 
         if args.is_empty() || matches.opt_present("h") || matches.opt_present("help") {
             crate::usage("rustdoc");
-            return Err(0);
+            return None;
         } else if matches.opt_present("version") {
             rustc_driver::version!(&early_dcx, "rustdoc", matches);
-            return Err(0);
+            return None;
         }
 
         if rustc_driver::describe_flag_categories(early_dcx, &matches) {
-            return Err(0);
+            return None;
         }
 
         let color = config::parse_color(early_dcx, matches);
@@ -382,7 +382,7 @@ impl Options {
                 }
             }
 
-            return Err(0);
+            return None;
         }
 
         let mut emit = Vec::new();
@@ -390,10 +390,7 @@ impl Options {
             for kind in list.split(',') {
                 match kind.parse() {
                     Ok(kind) => emit.push(kind),
-                    Err(()) => {
-                        dcx.err(format!("unrecognized emission type: {kind}"));
-                        return Err(1);
-                    }
+                    Err(()) => dcx.fatal(format!("unrecognized emission type: {kind}")),
                 }
             }
         }
@@ -403,7 +400,7 @@ impl Options {
             && !matches.opt_present("show-coverage")
             && !nightly_options::is_unstable_enabled(matches)
         {
-            early_dcx.early_fatal(
+            dcx.fatal(
                 "the -Z unstable-options flag must be passed to enable --output-format for documentation generation (see https://github.com/rust-lang/rust/issues/76578)",
             );
         }
@@ -420,10 +417,7 @@ impl Options {
             }
             let paths = match theme::load_css_paths(content) {
                 Ok(p) => p,
-                Err(e) => {
-                    dcx.err(e);
-                    return Err(1);
-                }
+                Err(e) => dcx.fatal(e),
             };
             let mut errors = 0;
 
@@ -442,9 +436,9 @@ impl Options {
                 }
             }
             if errors != 0 {
-                return Err(1);
+                dcx.fatal("[check-theme] one or more tests failed");
             }
-            return Err(0);
+            return None;
         }
 
         let (lint_opts, describe_lints, lint_cap) = get_cmd_lint_options(early_dcx, matches);
@@ -452,11 +446,9 @@ impl Options {
         let input = PathBuf::from(if describe_lints {
             "" // dummy, this won't be used
         } else if matches.free.is_empty() {
-            dcx.err("missing file operand");
-            return Err(1);
+            dcx.fatal("missing file operand");
         } else if matches.free.len() > 1 {
-            dcx.err("too many file operands");
-            return Err(1);
+            dcx.fatal("too many file operands");
         } else {
             &matches.free[0]
         });
@@ -466,10 +458,7 @@ impl Options {
         let externs = parse_externs(early_dcx, matches, &unstable_opts);
         let extern_html_root_urls = match parse_extern_html_roots(matches) {
             Ok(ex) => ex,
-            Err(err) => {
-                dcx.err(err);
-                return Err(1);
-            }
+            Err(err) => dcx.fatal(err),
         };
 
         let default_settings: Vec<Vec<(String, String)>> = vec![
@@ -526,16 +515,14 @@ impl Options {
         let no_run = matches.opt_present("no-run");
 
         if !should_test && no_run {
-            dcx.err("the `--test` flag must be passed to enable `--no-run`");
-            return Err(1);
+            dcx.fatal("the `--test` flag must be passed to enable `--no-run`");
         }
 
         let out_dir = matches.opt_str("out-dir").map(|s| PathBuf::from(&s));
         let output = matches.opt_str("output").map(|s| PathBuf::from(&s));
         let output = match (out_dir, output) {
             (Some(_), Some(_)) => {
-                dcx.err("cannot use both 'out-dir' and 'output' at once");
-                return Err(1);
+                dcx.fatal("cannot use both 'out-dir' and 'output' at once");
             }
             (Some(out_dir), None) => out_dir,
             (None, Some(output)) => output,
@@ -549,8 +536,7 @@ impl Options {
 
         if let Some(ref p) = extension_css {
             if !p.is_file() {
-                dcx.err("option --extend-css argument must be a file");
-                return Err(1);
+                dcx.fatal("option --extend-css argument must be a file");
             }
         }
 
@@ -566,31 +552,25 @@ impl Options {
             }
             let paths = match theme::load_css_paths(content) {
                 Ok(p) => p,
-                Err(e) => {
-                    dcx.err(e);
-                    return Err(1);
-                }
+                Err(e) => dcx.fatal(e),
             };
 
             for (theme_file, theme_s) in
                 matches.opt_strs("theme").iter().map(|s| (PathBuf::from(&s), s.to_owned()))
             {
                 if !theme_file.is_file() {
-                    dcx.struct_err(format!("invalid argument: \"{theme_s}\""))
+                    dcx.struct_fatal(format!("invalid argument: \"{theme_s}\""))
                         .with_help("arguments to --theme must be files")
                         .emit();
-                    return Err(1);
                 }
                 if theme_file.extension() != Some(OsStr::new("css")) {
-                    dcx.struct_err(format!("invalid argument: \"{theme_s}\""))
+                    dcx.struct_fatal(format!("invalid argument: \"{theme_s}\""))
                         .with_help("arguments to --theme must have a .css extension")
                         .emit();
-                    return Err(1);
                 }
                 let (success, ret) = theme::test_theme_against(&theme_file, &paths, &dcx);
                 if !success {
-                    dcx.err(format!("error loading theme file: \"{theme_s}\""));
-                    return Err(1);
+                    dcx.fatal(format!("error loading theme file: \"{theme_s}\""));
                 } else if !ret.is_empty() {
                     dcx.struct_warn(format!(
                         "theme file \"{theme_s}\" is missing CSS rules from the default theme",
@@ -620,22 +600,18 @@ impl Options {
             edition,
             &None,
         ) else {
-            return Err(3);
+            dcx.fatal("`ExternalHtml::load` failed");
         };
 
         match matches.opt_str("r").as_deref() {
             Some("rust") | None => {}
-            Some(s) => {
-                dcx.err(format!("unknown input format: {s}"));
-                return Err(1);
-            }
+            Some(s) => dcx.fatal(format!("unknown input format: {s}")),
         }
 
         let index_page = matches.opt_str("index-page").map(|s| PathBuf::from(&s));
         if let Some(ref index_page) = index_page {
             if !index_page.is_file() {
-                dcx.err("option `--index-page` argument must be a file");
-                return Err(1);
+                dcx.fatal("option `--index-page` argument must be a file");
             }
         }
 
@@ -646,8 +622,7 @@ impl Options {
         let crate_types = match parse_crate_types_from_list(matches.opt_strs("crate-type")) {
             Ok(types) => types,
             Err(e) => {
-                dcx.err(format!("unknown crate type: {e}"));
-                return Err(1);
+                dcx.fatal(format!("unknown crate type: {e}"));
             }
         };
 
@@ -655,18 +630,13 @@ impl Options {
             Some(s) => match OutputFormat::try_from(s.as_str()) {
                 Ok(out_fmt) => {
                     if !out_fmt.is_json() && show_coverage {
-                        dcx.struct_err(
+                        dcx.fatal(
                             "html output format isn't supported for the --show-coverage option",
-                        )
-                        .emit();
-                        return Err(1);
+                        );
                     }
                     out_fmt
                 }
-                Err(e) => {
-                    dcx.err(e);
-                    return Err(1);
-                }
+                Err(e) => dcx.fatal(e),
             },
             None => OutputFormat::default(),
         };
@@ -709,16 +679,14 @@ impl Options {
         let html_no_source = matches.opt_present("html-no-source");
 
         if generate_link_to_definition && (show_coverage || output_format != OutputFormat::Html) {
-            dcx.struct_err(
+            dcx.fatal(
                 "--generate-link-to-definition option can only be used with HTML output format",
-            )
-            .emit();
-            return Err(1);
+            );
         }
 
-        let scrape_examples_options = ScrapeExamplesOptions::new(matches, &dcx)?;
+        let scrape_examples_options = ScrapeExamplesOptions::new(matches, &dcx);
         let with_examples = matches.opt_strs("with-examples");
-        let call_locations = crate::scrape_examples::load_call_locations(with_examples, &dcx)?;
+        let call_locations = crate::scrape_examples::load_call_locations(with_examples, &dcx);
 
         let unstable_features =
             rustc_feature::UnstableFeatures::from_environment(crate_name.as_deref());
@@ -793,7 +761,7 @@ impl Options {
             no_emit_shared: false,
             html_no_source,
         };
-        Ok((options, render_options))
+        Some((options, render_options))
     }
 
     /// Returns `true` if the file given as `self.input` is a Markdown file.
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 8c10f14116a..097bbeb6d28 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -177,13 +177,16 @@ pub fn main() {
     init_logging(&early_dcx);
     rustc_driver::init_logger(&early_dcx, rustc_log::LoggerConfig::from_env("RUSTDOC_LOG"));
 
-    let exit_code = rustc_driver::catch_with_exit_code(|| match get_args(&early_dcx) {
-        Some(args) => main_args(&mut early_dcx, &args, using_internal_features),
-        _ =>
-        {
-            #[allow(deprecated)]
-            Err(ErrorGuaranteed::unchecked_claim_error_was_emitted())
-        }
+    let exit_code = rustc_driver::catch_with_exit_code(|| {
+        let args = env::args_os()
+            .enumerate()
+            .map(|(i, arg)| {
+                arg.into_string().unwrap_or_else(|arg| {
+                    early_dcx.early_fatal(format!("argument {i} is not valid Unicode: {arg:?}"))
+                })
+            })
+            .collect::<Vec<_>>();
+        main_args(&mut early_dcx, &args, using_internal_features)
     });
     process::exit(exit_code);
 }
@@ -219,19 +222,6 @@ fn init_logging(early_dcx: &EarlyDiagCtxt) {
     tracing::subscriber::set_global_default(subscriber).unwrap();
 }
 
-fn get_args(early_dcx: &EarlyDiagCtxt) -> Option<Vec<String>> {
-    env::args_os()
-        .enumerate()
-        .map(|(i, arg)| {
-            arg.into_string()
-                .map_err(|arg| {
-                    early_dcx.early_warn(format!("Argument {i} is not valid Unicode: {arg:?}"));
-                })
-                .ok()
-        })
-        .collect()
-}
-
 fn opts() -> Vec<RustcOptGroup> {
     let stable: fn(_, fn(&mut getopts::Options) -> &mut _) -> _ = RustcOptGroup::stable;
     let unstable: fn(_, fn(&mut getopts::Options) -> &mut _) -> _ = RustcOptGroup::unstable;
@@ -730,15 +720,8 @@ fn main_args(
     // Note that we discard any distinction between different non-zero exit
     // codes from `from_matches` here.
     let (options, render_options) = match config::Options::from_matches(early_dcx, &matches, args) {
-        Ok(opts) => opts,
-        Err(code) => {
-            return if code == 0 {
-                Ok(())
-            } else {
-                #[allow(deprecated)]
-                Err(ErrorGuaranteed::unchecked_claim_error_was_emitted())
-            };
-        }
+        Some(opts) => opts,
+        None => return Ok(()),
     };
 
     let diag =
diff --git a/src/librustdoc/scrape_examples.rs b/src/librustdoc/scrape_examples.rs
index b7d9c16f348..9c9b386edda 100644
--- a/src/librustdoc/scrape_examples.rs
+++ b/src/librustdoc/scrape_examples.rs
@@ -38,28 +38,23 @@ pub(crate) struct ScrapeExamplesOptions {
 }
 
 impl ScrapeExamplesOptions {
-    pub(crate) fn new(
-        matches: &getopts::Matches,
-        dcx: &rustc_errors::DiagCtxt,
-    ) -> Result<Option<Self>, i32> {
+    pub(crate) fn new(matches: &getopts::Matches, dcx: &rustc_errors::DiagCtxt) -> Option<Self> {
         let output_path = matches.opt_str("scrape-examples-output-path");
         let target_crates = matches.opt_strs("scrape-examples-target-crate");
         let scrape_tests = matches.opt_present("scrape-tests");
         match (output_path, !target_crates.is_empty(), scrape_tests) {
-            (Some(output_path), true, _) => Ok(Some(ScrapeExamplesOptions {
+            (Some(output_path), true, _) => Some(ScrapeExamplesOptions {
                 output_path: PathBuf::from(output_path),
                 target_crates,
                 scrape_tests,
-            })),
+            }),
             (Some(_), false, _) | (None, true, _) => {
-                dcx.err("must use --scrape-examples-output-path and --scrape-examples-target-crate together");
-                Err(1)
+                dcx.fatal("must use --scrape-examples-output-path and --scrape-examples-target-crate together");
             }
             (None, false, true) => {
-                dcx.err("must use --scrape-examples-output-path and --scrape-examples-target-crate with --scrape-tests");
-                Err(1)
+                dcx.fatal("must use --scrape-examples-output-path and --scrape-examples-target-crate with --scrape-tests");
             }
-            (None, false, false) => Ok(None),
+            (None, false, false) => None,
         }
     }
 }
@@ -342,24 +337,20 @@ pub(crate) fn run(
 pub(crate) fn load_call_locations(
     with_examples: Vec<String>,
     dcx: &rustc_errors::DiagCtxt,
-) -> Result<AllCallLocations, i32> {
-    let inner = || {
-        let mut all_calls: AllCallLocations = FxHashMap::default();
-        for path in with_examples {
-            let bytes = fs::read(&path).map_err(|e| format!("{e} (for path {path})"))?;
-            let mut decoder = MemDecoder::new(&bytes, 0);
-            let calls = AllCallLocations::decode(&mut decoder);
-
-            for (function, fn_calls) in calls.into_iter() {
-                all_calls.entry(function).or_default().extend(fn_calls.into_iter());
-            }
-        }
+) -> AllCallLocations {
+    let mut all_calls: AllCallLocations = FxHashMap::default();
+    for path in with_examples {
+        let bytes = match fs::read(&path) {
+            Ok(bytes) => bytes,
+            Err(e) => dcx.fatal(format!("failed to load examples: {e}")),
+        };
+        let mut decoder = MemDecoder::new(&bytes, 0);
+        let calls = AllCallLocations::decode(&mut decoder);
 
-        Ok(all_calls)
-    };
+        for (function, fn_calls) in calls.into_iter() {
+            all_calls.entry(function).or_default().extend(fn_calls.into_iter());
+        }
+    }
 
-    inner().map_err(|e: String| {
-        dcx.err(format!("failed to load examples: {e}"));
-        1
-    })
+    all_calls
 }
diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
index 1ef8cf7de3c..808fb0c07ea 100644
--- a/src/tools/build-manifest/src/main.rs
+++ b/src/tools/build-manifest/src/main.rs
@@ -83,6 +83,7 @@ static TARGETS: &[&str] = &[
     "armebv7r-none-eabihf",
     "armv7r-none-eabi",
     "armv7r-none-eabihf",
+    "armv8r-none-eabihf",
     "armv7s-apple-ios",
     "bpfeb-unknown-none",
     "bpfel-unknown-none",
diff --git a/src/tools/tidy/src/ui_tests.rs b/src/tools/tidy/src/ui_tests.rs
index e7b1ccf6a02..4a44c40debd 100644
--- a/src/tools/tidy/src/ui_tests.rs
+++ b/src/tools/tidy/src/ui_tests.rs
@@ -15,7 +15,7 @@ use std::path::{Path, PathBuf};
 const ENTRY_LIMIT: usize = 900;
 // FIXME: The following limits should be reduced eventually.
 const ISSUES_ENTRY_LIMIT: usize = 1819;
-const ROOT_ENTRY_LIMIT: usize = 870;
+const ROOT_ENTRY_LIMIT: usize = 871;
 
 const EXPECTED_TEST_FILE_EXTENSIONS: &[&str] = &[
     "rs",     // test source files
diff --git a/tests/assembly/targets/targets-elf.rs b/tests/assembly/targets/targets-elf.rs
index 41f5df0fba0..6105ea430dd 100644
--- a/tests/assembly/targets/targets-elf.rs
+++ b/tests/assembly/targets/targets-elf.rs
@@ -174,6 +174,9 @@
 // revisions: armv7r_none_eabihf
 // [armv7r_none_eabihf] compile-flags: --target armv7r-none-eabihf
 // [armv7r_none_eabihf] needs-llvm-components: arm
+// revisions: armv8r_none_eabihf
+// [armv8r_none_eabihf] compile-flags: --target armv8r-none-eabihf
+// [armv8r_none_eabihf] needs-llvm-components: arm
 // FIXME: disabled since it fails on CI saying the csky component is missing
 /*
     revisions: csky_unknown_linux_gnuabiv2
diff --git a/tests/codegen/direct-access-external-data.rs b/tests/codegen/direct-access-external-data.rs
new file mode 100644
index 00000000000..ec4bfc33518
--- /dev/null
+++ b/tests/codegen/direct-access-external-data.rs
@@ -0,0 +1,21 @@
+// only-loongarch64-unknown-linux-gnu
+
+// revisions: DEFAULT DIRECT INDIRECT
+// [DEFAULT] compile-flags: -C relocation-model=static
+// [DIRECT] compile-flags: -C relocation-model=static -Z direct-access-external-data=yes
+// [INDIRECT] compile-flags: -C relocation-model=static -Z direct-access-external-data=no
+
+#![crate_type = "rlib"]
+
+// DEFAULT: @VAR = external {{.*}} global i32
+// DIRECT: @VAR = external dso_local {{.*}} global i32
+// INDIRECT: @VAR = external {{.*}} global i32
+
+extern "C" {
+    static VAR: i32;
+}
+
+#[no_mangle]
+pub fn get() -> i32 {
+    unsafe { VAR }
+}
diff --git a/tests/mir-opt/remove_storage_markers.rs b/tests/mir-opt/remove_storage_markers.rs
index 6666ff3b726..27661ab3254 100644
--- a/tests/mir-opt/remove_storage_markers.rs
+++ b/tests/mir-opt/remove_storage_markers.rs
@@ -1,4 +1,3 @@
-// skip-filecheck
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
 // unit-test: RemoveStorageMarkers
 
@@ -8,6 +7,10 @@
 
 // EMIT_MIR remove_storage_markers.main.RemoveStorageMarkers.diff
 fn main() {
+    // CHECK-LABEL: fn main(
+
+    // CHECK-NOT: StorageDead
+    // CHECK-NOT: StorageLive
     let mut sum = 0;
     for i in 0..10 {
         sum += i;
diff --git a/tests/mir-opt/simplify_if.rs b/tests/mir-opt/simplify_if.rs
index 19b5806f720..f600c059581 100644
--- a/tests/mir-opt/simplify_if.rs
+++ b/tests/mir-opt/simplify_if.rs
@@ -1,10 +1,13 @@
-// skip-filecheck
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
 #[inline(never)]
 fn noop() {}
 
 // EMIT_MIR simplify_if.main.SimplifyConstCondition-after-const-prop.diff
 fn main() {
+    // CHECK-LABEL: fn main(
+
+    // CHECK: bb0: {
+    // CHECK-NEXT: return;
     if false {
         noop();
     }
diff --git a/tests/mir-opt/sroa/lifetimes.rs b/tests/mir-opt/sroa/lifetimes.rs
index cc5c0c9bbcd..ea04fac1571 100644
--- a/tests/mir-opt/sroa/lifetimes.rs
+++ b/tests/mir-opt/sroa/lifetimes.rs
@@ -1,4 +1,3 @@
-// skip-filecheck
 // unit-test: ScalarReplacementOfAggregates
 // compile-flags: -Cpanic=abort
 // no-prefer-dynamic
@@ -16,6 +15,10 @@ struct Foo<T: Err> {
 
 // EMIT_MIR lifetimes.foo.ScalarReplacementOfAggregates.diff
 fn foo<T: Err>() {
+    // CHECK-LABEL: fn foo(
+
+    // CHECK-NOT: [foo:_.*]: Foo
+    // CHECK-NOT: Box<dyn std::fmt::Display + 'static>
     let foo: Foo<T> = Foo {
         x: Ok(Box::new(5_u32)),
         y: 7_u32,
diff --git a/tests/mir-opt/sroa/structs.rs b/tests/mir-opt/sroa/structs.rs
index 73563e12c94..5ea3795b86e 100644
--- a/tests/mir-opt/sroa/structs.rs
+++ b/tests/mir-opt/sroa/structs.rs
@@ -1,4 +1,3 @@
-// skip-filecheck
 // unit-test: ScalarReplacementOfAggregates
 // compile-flags: -Cpanic=abort
 // no-prefer-dynamic
@@ -13,28 +12,68 @@ impl Drop for Tag {
     fn drop(&mut self) {}
 }
 
+/// Check that SROA excludes structs with a `Drop` implementation.
 pub fn dropping() {
+    // CHECK-LABEL: fn dropping(
+
+    // CHECK: [[aggregate:_[0-9]+]]: S;
+
+    // CHECK: bb0: {
+    // CHECK: [[aggregate]] = S
     S(Tag(0), Tag(1), Tag(2)).1;
 }
 
+/// Check that SROA excludes enums.
 pub fn enums(a: usize) -> usize {
+    // CHECK-LABEL: fn enums(
+
+    // CHECK: [[enum:_[0-9]+]]: std::option::Option<usize>;
+
+    // CHECK: bb0: {
+    // CHECK: [[enum]] = Option::<usize>::Some
+    // CHECK: _5 = (([[enum]] as Some).0: usize)
+    // CHECK: _0 = _5
     if let Some(a) = Some(a) { a } else { 0 }
 }
 
+/// Check that SROA destructures `U`.
 pub fn structs(a: f32) -> f32 {
+    // CHECK-LABEL: fn structs(
     struct U {
         _foo: usize,
         a: f32,
     }
-
+    // CHECK: [[ret:_0]]: f32;
+    // CHECK: [[struct:_[0-9]+]]: structs::U;
+    // CHECK: [[a_tmp:_[0-9]+]]: f32;
+    // CHECK: [[foo:_[0-9]+]]: usize;
+    // CHECK: [[a_ret:_[0-9]+]]: f32;
+
+    // CHECK: bb0: {
+    // CHECK-NOT: [[struct]]
+    // CHECK: [[a_tmp]] = _1;
+    // CHECK-NOT: [[struct]]
+    // CHECK: [[foo]] = const 0_usize;
+    // CHECK-NOT: [[struct]]
+    // CHECK: [[a_ret]] = move [[a_tmp]];
+    // CHECK-NOT: [[struct]]
+    // CHECK: _0 = [[a_ret]];
+    // CHECK-NOT: [[struct]]
     U { _foo: 0, a }.a
 }
 
+/// Check that SROA excludes unions.
 pub fn unions(a: f32) -> u32 {
+    // CHECK-LABEL: fn unions(
     union Repr {
         f: f32,
         u: u32,
     }
+    // CHECK: [[union:_[0-9]+]]: unions::Repr;
+
+    // CHECK: bb0: {
+    // CHECK: [[union]] = Repr {
+    // CHECK: _0 = ([[union]].1: u32)
     unsafe { Repr { f: a }.u }
 }
 
@@ -46,11 +85,21 @@ struct Foo {
     d: Option<isize>,
 }
 
-fn g() -> u32 {
-    3
-}
-
+/// Check that non-escaping uses of a struct are destructured.
 pub fn flat() {
+    // CHECK-LABEL: fn flat(
+
+    // CHECK: [[struct:_[0-9]+]]: Foo;
+
+    // CHECK: bb0: {
+    // CHECK: [[init_unit:_[0-9]+]] = ();
+    // CHECK: [[init_opt_isize:_[0-9]+]] = Option::<isize>::Some
+
+    // CHECK: [[destr_five:_[0-9]+]] = const 5_u8;
+    // CHECK: [[destr_unit:_[0-9]+]] = move [[init_unit]];
+    // CHECK: [[destr_a:_[0-9]+]] = const "a";
+    // CHECK: [[destr_opt_isize:_[0-9]+]] = move [[init_opt_isize]];
+
     let Foo { a, b, c, d } = Foo { a: 5, b: (), c: "a", d: Some(-4) };
     let _ = a;
     let _ = b;
@@ -65,6 +114,10 @@ struct Escaping {
     c: u32,
 }
 
+fn g() -> u32 {
+    3
+}
+
 fn f(a: *const u32) {
     println!("{}", unsafe { *a.add(2) });
 }
@@ -76,10 +129,38 @@ fn f(a: *const u32) {
 // of them to `f`. However, this would lead to a miscompilation because `b` and `c`
 // might no longer appear right after `a` in memory.
 pub fn escaping() {
+    // CHECK-LABEL: fn escaping(
+
+    // CHECK: [[ptr:_[0-9]+]]: *const u32;
+    // CHECK: [[ref:_[0-9]+]]: &u32;
+    // CHECK: [[struct:_[0-9]+]]: Escaping;
+    // CHECK: [[a:_[0-9]+]]: u32;
+
+    // CHECK: bb0: {
+    // CHECK: [[struct]] = Escaping {
+    // CHECK: [[ref]] = &([[struct]].0
+    // CHECK: [[ptr]] = &raw const (*[[ref]]);
     f(&Escaping { a: 1, b: 2, c: g() }.a);
 }
 
+/// Check that copies from an internal struct are destructured and reassigned to
+/// the original struct.
 fn copies(x: Foo) {
+    // CHECK-LABEL: fn copies(
+
+    // CHECK: [[external:_[0-9]+]]: Foo) ->
+    // CHECK: [[internal:_[0-9]+]]: Foo;
+    // CHECK: [[byte:_[0-9]+]]: u8;
+    // CHECK: [[unit:_[0-9]+]]: ();
+    // CHECK: [[str:_[0-9]+]]: &str;
+    // CHECK: [[opt_isize:_[0-9]+]]: std::option::Option<isize>;
+
+    // CHECK: bb0: {
+    // CHECK: [[byte]] = ([[external]].0
+    // CHECK: [[unit]] = ([[external]].1
+    // CHECK: [[str]] = ([[external]].2
+    // CHECK: [[opt_isize]] = ([[external]].3
+
     let y = x;
     let t = y.a;
     let u = y.c;
@@ -87,13 +168,44 @@ fn copies(x: Foo) {
     let a = z.b;
 }
 
+/// Check that copies from an internal struct are destructured and reassigned to
+/// the original struct.
 fn ref_copies(x: &Foo) {
+    // CHECK-LABEL: fn ref_copies(
+
+    // CHECK: [[external:_[0-9]+]]: &Foo) ->
+    // CHECK: [[internal:_[0-9]+]]: Foo;
+    // CHECK: [[byte:_[0-9]+]]: u8;
+    // CHECK: [[unit:_[0-9]+]]: ();
+    // CHECK: [[str:_[0-9]+]]: &str;
+    // CHECK: [[opt_isize:_[0-9]+]]: std::option::Option<isize>;
+
+    // CHECK: bb0: {
+    // CHECK: [[byte]] = ((*[[external]]).0
+    // CHECK: [[unit]] = ((*[[external]]).1
+    // CHECK: [[str]] = ((*[[external]]).2
+    // CHECK: [[opt_isize]] = ((*[[external]]).3
+
     let y = *x;
     let t = y.a;
     let u = y.c;
 }
 
+/// Check that deaggregated assignments from constants are placed after the constant's
+/// assignment. Also check that copying field accesses from the copy of the constant are
+/// reassigned to copy from the constant.
 fn constant() {
+    // CHECK-LABEL: constant(
+
+    // CHECK: [[constant:_[0-9]+]]: (usize, u8);
+    // CHECK: [[t:_[0-9]+]]: usize;
+    // CHECK: [[u:_[0-9]+]]: u8;
+
+    // CHECK: bb0: {
+    // CHECK-NOT: [[constant]]
+    // CHECK: [[constant]] = const
+    // CHECK: [[t]] = move ([[constant]].0: usize)
+    // CHECK: [[u]] = move ([[constant]].1: u8)
     const U: (usize, u8) = (5, 9);
     let y = U;
     let t = y.0;
@@ -101,6 +213,7 @@ fn constant() {
 }
 
 fn main() {
+    // CHECK-LABEL: fn main(
     dropping();
     enums(5);
     structs(5.);
diff --git a/tests/ui/binding/irrefutable-if-let-without-else.fixed b/tests/ui/binding/irrefutable-if-let-without-else.fixed
new file mode 100644
index 00000000000..3d7f4695ca8
--- /dev/null
+++ b/tests/ui/binding/irrefutable-if-let-without-else.fixed
@@ -0,0 +1,25 @@
+// run-rustfix
+enum Enum {
+    Variant(i32),
+}
+struct Struct(i32);
+
+fn foo(x: Enum) -> i32 {
+    let Enum::Variant(value) = x;
+        value
+}
+fn bar(x: Enum) -> i32 {
+    let Enum::Variant(value) = x;
+        let x = value + 1;
+        x
+}
+fn baz(x: Struct) -> i32 {
+    let Struct(value) = x;
+        let x = value + 1;
+        x
+}
+fn main() {
+    let _ = foo(Enum::Variant(42));
+    let _ = bar(Enum::Variant(42));
+    let _ = baz(Struct(42));
+}
diff --git a/tests/ui/binding/irrefutable-if-let-without-else.rs b/tests/ui/binding/irrefutable-if-let-without-else.rs
new file mode 100644
index 00000000000..5aaf4ace3f8
--- /dev/null
+++ b/tests/ui/binding/irrefutable-if-let-without-else.rs
@@ -0,0 +1,28 @@
+// run-rustfix
+enum Enum {
+    Variant(i32),
+}
+struct Struct(i32);
+
+fn foo(x: Enum) -> i32 {
+    if let Enum::Variant(value) = x { //~ ERROR `if` may be missing an `else` clause
+        value
+    }
+}
+fn bar(x: Enum) -> i32 {
+    if let Enum::Variant(value) = x { //~ ERROR `if` may be missing an `else` clause
+        let x = value + 1;
+        x
+    }
+}
+fn baz(x: Struct) -> i32 {
+    if let Struct(value) = x { //~ ERROR `if` may be missing an `else` clause
+        let x = value + 1;
+        x
+    }
+}
+fn main() {
+    let _ = foo(Enum::Variant(42));
+    let _ = bar(Enum::Variant(42));
+    let _ = baz(Struct(42));
+}
diff --git a/tests/ui/binding/irrefutable-if-let-without-else.stderr b/tests/ui/binding/irrefutable-if-let-without-else.stderr
new file mode 100644
index 00000000000..e234cfdd945
--- /dev/null
+++ b/tests/ui/binding/irrefutable-if-let-without-else.stderr
@@ -0,0 +1,61 @@
+error[E0317]: `if` may be missing an `else` clause
+  --> $DIR/irrefutable-if-let-without-else.rs:8:5
+   |
+LL |   fn foo(x: Enum) -> i32 {
+   |                      --- expected `i32` because of this return type
+LL | /     if let Enum::Variant(value) = x {
+LL | |         value
+LL | |     }
+   | |_____^ expected `i32`, found `()`
+   |
+   = note: `if` expressions without `else` evaluate to `()`
+   = help: consider adding an `else` block that evaluates to the expected type
+help: consider using an irrefutable `let` binding instead
+   |
+LL ~     let Enum::Variant(value) = x;
+LL ~         value
+   |
+
+error[E0317]: `if` may be missing an `else` clause
+  --> $DIR/irrefutable-if-let-without-else.rs:13:5
+   |
+LL |   fn bar(x: Enum) -> i32 {
+   |                      --- expected `i32` because of this return type
+LL | /     if let Enum::Variant(value) = x {
+LL | |         let x = value + 1;
+LL | |         x
+LL | |     }
+   | |_____^ expected `i32`, found `()`
+   |
+   = note: `if` expressions without `else` evaluate to `()`
+   = help: consider adding an `else` block that evaluates to the expected type
+help: consider using an irrefutable `let` binding instead
+   |
+LL ~     let Enum::Variant(value) = x;
+LL ~         let x = value + 1;
+LL ~         x
+   |
+
+error[E0317]: `if` may be missing an `else` clause
+  --> $DIR/irrefutable-if-let-without-else.rs:19:5
+   |
+LL |   fn baz(x: Struct) -> i32 {
+   |                        --- expected `i32` because of this return type
+LL | /     if let Struct(value) = x {
+LL | |         let x = value + 1;
+LL | |         x
+LL | |     }
+   | |_____^ expected `i32`, found `()`
+   |
+   = note: `if` expressions without `else` evaluate to `()`
+   = help: consider adding an `else` block that evaluates to the expected type
+help: consider using an irrefutable `let` binding instead
+   |
+LL ~     let Struct(value) = x;
+LL ~         let x = value + 1;
+LL ~         x
+   |
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0317`.
diff --git a/tests/ui/coroutine/polymorphize-args.rs b/tests/ui/coroutine/polymorphize-args.rs
new file mode 100644
index 00000000000..de44d667656
--- /dev/null
+++ b/tests/ui/coroutine/polymorphize-args.rs
@@ -0,0 +1,17 @@
+// compile-flags: -Zpolymorphize=on
+// build-pass
+
+#![feature(coroutines, coroutine_trait)]
+
+use std::ops::Coroutine;
+use std::pin::Pin;
+use std::thread;
+
+fn main() {
+    let mut foo = || yield;
+    thread::spawn(move || match Pin::new(&mut foo).resume(()) {
+        s => panic!("bad state: {:?}", s),
+    })
+    .join()
+    .unwrap();
+}
diff --git a/tests/ui/lint/future-incompat-json-test.stderr b/tests/ui/lint/future-incompat-json-test.stderr
index c4ab5a00d16..18fc3f17f00 100644
--- a/tests/ui/lint/future-incompat-json-test.stderr
+++ b/tests/ui/lint/future-incompat-json-test.stderr
@@ -1,4 +1,4 @@
-{"$message_type":"future_incompat","future_incompat_report":[{"diagnostic":{"$message_type":"diagnostic","message":"unused variable: `x`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"$DIR/future-incompat-json-test.rs","byte_start":338,"byte_end":339,"line_start":9,"line_end":9,"column_start":9,"column_end":10,"is_primary":true,"text":[{"text":"    let x = 1;","highlight_start":9,"highlight_end":10}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"`-A unused-variables` implied by `-A unused`","code":null,"level":"note","spans":[],"children":[],"rendered":null},{"message":"to override `-A unused` add `#[allow(unused_variables)]`","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"if this is intentional, prefix it with an underscore","code":null,"level":"help","spans":[{"file_name":"$DIR/future-incompat-json-test.rs","byte_start":338,"byte_end":339,"line_start":9,"line_end":9,"column_start":9,"column_end":10,"is_primary":true,"text":[{"text":"    let x = 1;","highlight_start":9,"highlight_end":10}],"label":null,"suggested_replacement":"_x","suggestion_applicability":"MachineApplicable","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `x`
+{"$message_type":"future_incompat","future_incompat_report":[{"diagnostic":{"$message_type":"diagnostic","message":"unused variable: `x`","code":{"code":"unused_variables","explanation":null},"level":"warning","spans":[{"file_name":"$DIR/future-incompat-json-test.rs","byte_start":338,"byte_end":339,"line_start":9,"line_end":9,"column_start":9,"column_end":10,"is_primary":true,"text":[{"text":"    let x = 1;","highlight_start":9,"highlight_end":10}],"label":null,"suggested_replacement":null,"suggestion_applicability":null,"expansion":null}],"children":[{"message":"`-A unused-variables` implied by `-A unused`","code":null,"level":"note","spans":[],"children":[],"rendered":null},{"message":"to override `-A unused` add `#[allow(unused_variables)]`","code":null,"level":"help","spans":[],"children":[],"rendered":null},{"message":"if this is intentional, prefix it with an underscore","code":null,"level":"help","spans":[{"file_name":"$DIR/future-incompat-json-test.rs","byte_start":338,"byte_end":339,"line_start":9,"line_end":9,"column_start":9,"column_end":10,"is_primary":true,"text":[{"text":"    let x = 1;","highlight_start":9,"highlight_end":10}],"label":null,"suggested_replacement":"_x","suggestion_applicability":"MaybeIncorrect","expansion":null}],"children":[],"rendered":null}],"rendered":"warning: unused variable: `x`
   --> $DIR/future-incompat-json-test.rs:9:9
    |
 LL |     let x = 1;
diff --git a/tests/ui/parallel-rustc/cache-after-waiting-issue-111528.rs b/tests/ui/parallel-rustc/cache-after-waiting-issue-111528.rs
new file mode 100644
index 00000000000..148a59240f9
--- /dev/null
+++ b/tests/ui/parallel-rustc/cache-after-waiting-issue-111528.rs
@@ -0,0 +1,16 @@
+// compile-flags: -Z threads=16
+// build-fail
+
+#![crate_type="rlib"]
+#![allow(warnings)]
+
+#[export_name="fail"]
+pub fn a() {
+}
+
+#[export_name="fail"]
+pub fn b() {
+//~^ Error symbol `fail` is already defined
+}
+
+fn main() {}
diff --git a/tests/ui/parallel-rustc/cache-after-waiting-issue-111528.stderr b/tests/ui/parallel-rustc/cache-after-waiting-issue-111528.stderr
new file mode 100644
index 00000000000..7963165e31b
--- /dev/null
+++ b/tests/ui/parallel-rustc/cache-after-waiting-issue-111528.stderr
@@ -0,0 +1,8 @@
+error: symbol `fail` is already defined
+  --> $DIR/cache-after-waiting-issue-111528.rs:12:1
+   |
+LL | pub fn b() {
+   | ^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/parallel-rustc/export-symbols-deadlock-issue-118205-2.rs b/tests/ui/parallel-rustc/export-symbols-deadlock-issue-118205-2.rs
new file mode 100644
index 00000000000..8240b249018
--- /dev/null
+++ b/tests/ui/parallel-rustc/export-symbols-deadlock-issue-118205-2.rs
@@ -0,0 +1,7 @@
+// compile-flags:-C extra-filename=-1 -Z threads=16
+// no-prefer-dynamic
+// build-pass
+#![crate_name = "crateresolve1"]
+#![crate_type = "lib"]
+
+pub fn f() -> isize { 10 }
diff --git a/tests/ui/parallel-rustc/export-symbols-deadlock-issue-118205.rs b/tests/ui/parallel-rustc/export-symbols-deadlock-issue-118205.rs
new file mode 100644
index 00000000000..691c36cfc9e
--- /dev/null
+++ b/tests/ui/parallel-rustc/export-symbols-deadlock-issue-118205.rs
@@ -0,0 +1,22 @@
+// compile-flags: -Z threads=16
+// build-pass
+
+pub static GLOBAL: isize = 3;
+
+static GLOBAL0: isize = 4;
+
+pub static GLOBAL2: &'static isize = &GLOBAL0;
+
+pub fn verify_same(a: &'static isize) {
+    let a = a as *const isize as usize;
+    let b = &GLOBAL as *const isize as usize;
+    assert_eq!(a, b);
+}
+
+pub fn verify_same2(a: &'static isize) {
+    let a = a as *const isize as usize;
+    let b = GLOBAL2 as *const isize as usize;
+    assert_eq!(a, b);
+}
+
+fn main() {}
diff --git a/tests/ui/parallel-rustc/hello_world.rs b/tests/ui/parallel-rustc/hello_world.rs
new file mode 100644
index 00000000000..53e95c890ef
--- /dev/null
+++ b/tests/ui/parallel-rustc/hello_world.rs
@@ -0,0 +1,6 @@
+// compile-flags: -Z threads=8
+// run-pass
+
+fn main() {
+    println!("Hello world!");
+}
diff --git a/tests/ui/parallel-rustc/read-stolen-value-issue-111520.rs b/tests/ui/parallel-rustc/read-stolen-value-issue-111520.rs
new file mode 100644
index 00000000000..1907348cf09
--- /dev/null
+++ b/tests/ui/parallel-rustc/read-stolen-value-issue-111520.rs
@@ -0,0 +1,18 @@
+// compile-flags: -Z threads=16
+// run-pass
+
+#[repr(transparent)]
+struct Sched {
+    i: i32,
+}
+impl Sched {
+    extern "C" fn get(self) -> i32 { self.i }
+}
+
+fn main() {
+    let s = Sched { i: 4 };
+    let f = || -> i32 {
+        s.get()
+    };
+    println!("f: {}", f());
+}