Unrolled build for #145399

Rollup merge of #145399 - estebank:resolve-error-wording-2, r=petrochenkov

Unify wording of resolve error

Remove "failed to resolve" from the main error message and use the same format we use in other resolution errors "cannot find `name`":

```
error[E0433]: cannot find `nonexistent` in `existent`
  --> $DIR/custom_attr_multisegment_error.rs:5:13
   |
LL | #[existent::nonexistent]
   |             ^^^^^^^^^^^ could not find `nonexistent` in `existent`
```

The intent behind this is to end up with all resolve errors eventually be on the form of

```
error[ECODE]: cannot find `{NAME}` in {SCOPE}
  --> $DIR/file.rs:5:13
   |
LL | #[existent::nonexistent]
   |             ^^^^^^^^^^^ {SPECIFIC LABEL}
```

A category of errors that is interest are those that involve keywords. For example:

```
error[E0433]: cannot find `Self` in this scope
  --> $DIR/issue-97194.rs:2:35
   |
LL |     fn bget(&self, index: [usize; Self::DIM]) -> bool {
   |                                   ^^^^ `Self` is only available in impls, traits, and type definitions
```
and

```
error[E0433]: cannot find `super` in this scope
  --> $DIR/keyword-super.rs:2:9
   |
LL |     let super: isize;
   |         ^^^^^ there are too many leading `super` keywords
```

For these the label provides the actual help, while the message is less informative beyond telling you "couldn't find `name`".

This is an off-shoot of https://github.com/rust-lang/rust/pull/126810 and https://github.com/rust-lang/rust/pull/128086, a subset of the intended changes there with review comments applied.

r? @petrochenkov

compiler/rustc_borrowck/src/lib.rs

@@ -1544,7 +1544,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
             Rvalue::Use(operand)
             | Rvalue::Repeat(operand, _)
             | Rvalue::UnaryOp(_ /*un_op*/, operand)
-            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/) => {
+            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/)
+            | Rvalue::ShallowInitBox(operand, _ /*ty*/) => {
                 self.consume_operand(location, (operand, span), state)
             }
 

compiler/rustc_borrowck/src/polonius/legacy/loan_invalidations.rs

@@ -297,9 +297,8 @@ impl<'a, 'tcx> LoanInvalidationsGenerator<'a, 'tcx> {
             Rvalue::Use(operand)
             | Rvalue::Repeat(operand, _)
             | Rvalue::UnaryOp(_ /*un_op*/, operand)
-            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/) => {
-                self.consume_operand(location, operand)
-            }
+            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/)
+            | Rvalue::ShallowInitBox(operand, _ /*ty*/) => self.consume_operand(location, operand),
 
             &Rvalue::Discriminant(place) => {
                 self.access_place(

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1004,6 +1004,17 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 }
             }
 
+            Rvalue::ShallowInitBox(_operand, ty) => {
+                let trait_ref =
+                    ty::TraitRef::new(tcx, tcx.require_lang_item(LangItem::Sized, span), [*ty]);
+
+                self.prove_trait_ref(
+                    trait_ref,
+                    location.to_locations(),
+                    ConstraintCategory::SizedBound,
+                );
+            }
+
             Rvalue::Cast(cast_kind, op, ty) => {
                 match *cast_kind {
                     CastKind::PointerCoercion(
@@ -2220,6 +2231,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             | Rvalue::Ref(..)
             | Rvalue::RawPtr(..)
             | Rvalue::Cast(..)
+            | Rvalue::ShallowInitBox(..)
             | Rvalue::BinaryOp(..)
             | Rvalue::CopyForDeref(..)
             | Rvalue::UnaryOp(..)

compiler/rustc_codegen_cranelift/src/base.rs

@@ -902,6 +902,7 @@ fn codegen_stmt<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, cur_block: Block, stmt:
                     lval.write_cvalue_transmute(fx, operand);
                 }
                 Rvalue::CopyForDeref(_) => bug!("`CopyForDeref` in codegen"),
+                Rvalue::ShallowInitBox(..) => bug!("`ShallowInitBox` in codegen"),
             }
         }
         StatementKind::StorageLive(_)

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -710,6 +710,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 OperandRef { val: operand.val, layout, move_annotation: None }
             }
             mir::Rvalue::CopyForDeref(_) => bug!("`CopyForDeref` in codegen"),
+            mir::Rvalue::ShallowInitBox(..) => bug!("`ShallowInitBox` in codegen"),
         }
     }
 

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -646,6 +646,8 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
 
             Rvalue::Cast(_, _, _) => {}
 
+            Rvalue::ShallowInitBox(_, _) => {}
+
             Rvalue::UnaryOp(op, operand) => {
                 let ty = operand.ty(self.body, self.tcx);
                 match op {

compiler/rustc_const_eval/src/check_consts/qualifs.rs

@@ -237,7 +237,8 @@ where
         Rvalue::Use(operand)
         | Rvalue::Repeat(operand, _)
         | Rvalue::UnaryOp(_, operand)
-        | Rvalue::Cast(_, operand, _) => in_operand::<Q, _>(cx, in_local, operand),
+        | Rvalue::Cast(_, operand, _)
+        | Rvalue::ShallowInitBox(operand, _) => in_operand::<Q, _>(cx, in_local, operand),
 
         Rvalue::BinaryOp(_, box (lhs, rhs)) => {
             in_operand::<Q, _>(cx, in_local, lhs) || in_operand::<Q, _>(cx, in_local, rhs)

compiler/rustc_const_eval/src/check_consts/resolver.rs

@@ -192,6 +192,7 @@ where
             }
 
             mir::Rvalue::Cast(..)
+            | mir::Rvalue::ShallowInitBox(..)
             | mir::Rvalue::Use(..)
             | mir::Rvalue::CopyForDeref(..)
             | mir::Rvalue::ThreadLocalRef(..)

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -236,7 +236,7 @@ impl<'tcx> CompileTimeInterpCx<'tcx> {
         if self.tcx.is_lang_item(def_id, LangItem::PanicDisplay)
             || self.tcx.is_lang_item(def_id, LangItem::BeginPanic)
         {
-            let args = Self::copy_fn_args(args);
+            let args = self.copy_fn_args(args);
             // &str or &&str
             assert!(args.len() == 1);
 

compiler/rustc_const_eval/src/interpret/call.rs

@@ -19,8 +19,8 @@ use tracing::{info, instrument, trace};
 
 use super::{
     CtfeProvenance, FnVal, ImmTy, InterpCx, InterpResult, MPlaceTy, Machine, OpTy, PlaceTy,
-    Projectable, Provenance, ReturnAction, ReturnContinuation, Scalar, interp_ok, throw_ub,
-    throw_ub_custom,
+    Projectable, Provenance, ReturnAction, ReturnContinuation, Scalar, StackPopInfo, interp_ok,
+    throw_ub, throw_ub_custom,
 };
 use crate::enter_trace_span;
 use crate::interpret::EnteredTraceSpan;
@@ -43,22 +43,25 @@ impl<'tcx, Prov: Provenance> FnArg<'tcx, Prov> {
             FnArg::InPlace(mplace) => &mplace.layout,
         }
     }
+}
 
+impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     /// Make a copy of the given fn_arg. Any `InPlace` are degenerated to copies, no protection of the
     /// original memory occurs.
-    pub fn copy_fn_arg(&self) -> OpTy<'tcx, Prov> {
-        match self {
+    pub fn copy_fn_arg(&self, arg: &FnArg<'tcx, M::Provenance>) -> OpTy<'tcx, M::Provenance> {
+        match arg {
             FnArg::Copy(op) => op.clone(),
             FnArg::InPlace(mplace) => mplace.clone().into(),
         }
     }
-}
 
-impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     /// Make a copy of the given fn_args. Any `InPlace` are degenerated to copies, no protection of the
     /// original memory occurs.
-    pub fn copy_fn_args(args: &[FnArg<'tcx, M::Provenance>]) -> Vec<OpTy<'tcx, M::Provenance>> {
-        args.iter().map(|fn_arg| fn_arg.copy_fn_arg()).collect()
+    pub fn copy_fn_args(
+        &self,
+        args: &[FnArg<'tcx, M::Provenance>],
+    ) -> Vec<OpTy<'tcx, M::Provenance>> {
+        args.iter().map(|fn_arg| self.copy_fn_arg(fn_arg)).collect()
     }
 
     /// Helper function for argument untupling.
@@ -316,7 +319,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // We work with a copy of the argument for now; if this is in-place argument passing, we
         // will later protect the source it comes from. This means the callee cannot observe if we
         // did in-place of by-copy argument passing, except for pointer equality tests.
-        let caller_arg_copy = caller_arg.copy_fn_arg();
+        let caller_arg_copy = self.copy_fn_arg(caller_arg);
         if !already_live {
             let local = callee_arg.as_local().unwrap();
             let meta = caller_arg_copy.meta();
@@ -613,7 +616,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 if let Some(fallback) = M::call_intrinsic(
                     self,
                     instance,
-                    &Self::copy_fn_args(args),
+                    &self.copy_fn_args(args),
                     destination,
                     target,
                     unwind,
@@ -700,7 +703,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 // An `InPlace` does nothing here, we keep the original receiver intact. We can't
                 // really pass the argument in-place anyway, and we are constructing a new
                 // `Immediate` receiver.
-                let mut receiver = args[0].copy_fn_arg();
+                let mut receiver = self.copy_fn_arg(&args[0]);
                 let receiver_place = loop {
                     match receiver.layout.ty.kind() {
                         ty::Ref(..) | ty::RawPtr(..) => {
@@ -821,50 +824,41 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         with_caller_location: bool,
     ) -> InterpResult<'tcx> {
         trace!("init_fn_tail_call: {:#?}", fn_val);
+
         // This is the "canonical" implementation of tails calls,
         // a pop of the current stack frame, followed by a normal call
         // which pushes a new stack frame, with the return address from
         // the popped stack frame.
         //
-        // Note that we cannot use `return_from_current_stack_frame`,
-        // as that "executes" the goto to the return block, but we don't want to,
+        // Note that we are using `pop_stack_frame_raw` and not `return_from_current_stack_frame`,
+        // as the latter "executes" the goto to the return block, but we don't want to,
         // only the tail called function should return to the current return block.
+        let StackPopInfo { return_action, return_cont, return_place } =
+            self.pop_stack_frame_raw(false, |_this, _return_place| {
+                // This function's return value is just discarded, the tail-callee will fill in the return place instead.
+                interp_ok(())
+            })?;
 
-        // The arguments need to all be copied since the current stack frame will be removed
-        // before the callee even starts executing.
-        // FIXME(explicit_tail_calls,#144855): does this match what codegen does?
-        let args = args.iter().map(|fn_arg| FnArg::Copy(fn_arg.copy_fn_arg())).collect::<Vec<_>>();
-        // Remove the frame from the stack.
-        let frame = self.pop_stack_frame_raw()?;
-        // Remember where this frame would have returned to.
-        let ReturnContinuation::Goto { ret, unwind } = frame.return_cont() else {
-            bug!("can't tailcall as root of the stack");
+        assert_eq!(return_action, ReturnAction::Normal);
+
+        // Take the "stack pop cleanup" info, and use that to initiate the next call.
+        let ReturnContinuation::Goto { ret, unwind } = return_cont else {
+            bug!("can't tailcall as root");
         };
-        // There's no return value to deal with! Instead, we forward the old return place
-        // to the new function.
+
         // FIXME(explicit_tail_calls):
         //   we should check if both caller&callee can/n't unwind,
         //   see <https://github.com/rust-lang/rust/pull/113128#issuecomment-1614979803>
 
-        // Now push the new stack frame.
         self.init_fn_call(
             fn_val,
             (caller_abi, caller_fn_abi),
-            &*args,
+            args,
             with_caller_location,
-            frame.return_place(),
+            &return_place,
             ret,
             unwind,
-        )?;
-
-        // Finally, clear the local variables. Has to be done after pushing to support
-        // non-scalar arguments.
-        // FIXME(explicit_tail_calls,#144855): revisit this once codegen supports indirect
-        // arguments, to ensure the semantics are compatible.
-        let return_action = self.cleanup_stack_frame(/* unwinding */ false, frame)?;
-        assert_eq!(return_action, ReturnAction::Normal);
-
-        interp_ok(())
+        )
     }
 
     pub(super) fn init_drop_in_place_call(
@@ -959,18 +953,14 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // local's value out.
         let return_op =
             self.local_to_op(mir::RETURN_PLACE, None).expect("return place should always be live");
-        // Remove the frame from the stack.
-        let frame = self.pop_stack_frame_raw()?;
-        // Copy the return value and remember the return continuation.
-        if !unwinding {
-            self.copy_op_allow_transmute(&return_op, frame.return_place())?;
-            trace!("return value: {:?}", self.dump_place(frame.return_place()));
-        }
-        let return_cont = frame.return_cont();
-        // Finish popping the stack frame.
-        let return_action = self.cleanup_stack_frame(unwinding, frame)?;
-        // Jump to the next block.
-        match return_action {
+        // Do the actual pop + copy.
+        let stack_pop_info = self.pop_stack_frame_raw(unwinding, |this, return_place| {
+            this.copy_op_allow_transmute(&return_op, return_place)?;
+            trace!("return value: {:?}", this.dump_place(return_place));
+            interp_ok(())
+        })?;
+
+        match stack_pop_info.return_action {
             ReturnAction::Normal => {}
             ReturnAction::NoJump => {
                 // The hook already did everything.
@@ -988,7 +978,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // Normal return, figure out where to jump.
         if unwinding {
             // Follow the unwind edge.
-            match return_cont {
+            match stack_pop_info.return_cont {
                 ReturnContinuation::Goto { unwind, .. } => {
                     // This must be the very last thing that happens, since it can in fact push a new stack frame.
                     self.unwind_to_block(unwind)
@@ -999,7 +989,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             }
         } else {
             // Follow the normal return edge.
-            match return_cont {
+            match stack_pop_info.return_cont {
                 ReturnContinuation::Goto { ret, .. } => self.return_to_block(ret),
                 ReturnContinuation::Stop { .. } => {
                     assert!(

compiler/rustc_const_eval/src/interpret/mod.rs

@@ -36,7 +36,7 @@ pub use self::operand::{ImmTy, Immediate, OpTy};
 pub use self::place::{MPlaceTy, MemPlaceMeta, PlaceTy, Writeable};
 use self::place::{MemPlace, Place};
 pub use self::projection::{OffsetMode, Projectable};
-pub use self::stack::{Frame, FrameInfo, LocalState, ReturnContinuation};
+pub use self::stack::{Frame, FrameInfo, LocalState, ReturnContinuation, StackPopInfo};
 pub use self::util::EnteredTraceSpan;
 pub(crate) use self::util::create_static_alloc;
 pub use self::validity::{CtfeValidationMode, RangeSet, RefTracking};

compiler/rustc_const_eval/src/interpret/stack.rs

@@ -81,7 +81,7 @@ pub struct Frame<'tcx, Prov: Provenance = CtfeProvenance, Extra = ()> {
     /// and its layout in the caller. This place is to be interpreted relative to the
     /// *caller's* stack frame. We use a `PlaceTy` instead of an `MPlaceTy` since this
     /// avoids having to move *all* return places into Miri's memory.
-    return_place: PlaceTy<'tcx, Prov>,
+    pub return_place: PlaceTy<'tcx, Prov>,
 
     /// The list of locals for this stack frame, stored in order as
     /// `[return_ptr, arguments..., variables..., temporaries...]`.
@@ -127,6 +127,19 @@ pub enum ReturnContinuation {
     Stop { cleanup: bool },
 }
 
+/// Return type of [`InterpCx::pop_stack_frame_raw`].
+pub struct StackPopInfo<'tcx, Prov: Provenance> {
+    /// Additional information about the action to be performed when returning from the popped
+    /// stack frame.
+    pub return_action: ReturnAction,
+
+    /// [`return_cont`](Frame::return_cont) of the popped stack frame.
+    pub return_cont: ReturnContinuation,
+
+    /// [`return_place`](Frame::return_place) of the popped stack frame.
+    pub return_place: PlaceTy<'tcx, Prov>,
+}
+
 /// State of a local variable including a memoized layout
 #[derive(Clone)]
 pub struct LocalState<'tcx, Prov: Provenance = CtfeProvenance> {
@@ -279,14 +292,6 @@ impl<'tcx, Prov: Provenance, Extra> Frame<'tcx, Prov, Extra> {
         self.instance
     }
 
-    pub fn return_place(&self) -> &PlaceTy<'tcx, Prov> {
-        &self.return_place
-    }
-
-    pub fn return_cont(&self) -> ReturnContinuation {
-        self.return_cont
-    }
-
     /// Return the `SourceInfo` of the current instruction.
     pub fn current_source_info(&self) -> Option<&mir::SourceInfo> {
         self.loc.left().map(|loc| self.body.source_info(loc))
@@ -412,26 +417,35 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         interp_ok(())
     }
 
-    /// Low-level helper that pops a stack frame from the stack without any cleanup.
-    /// This invokes `before_stack_pop`.
-    /// After calling this function, you need to deal with the return value, and then
-    /// invoke `cleanup_stack_frame`.
+    /// Low-level helper that pops a stack frame from the stack and returns some information about
+    /// it.
+    ///
+    /// This also deallocates locals, if necessary.
+    /// `copy_ret_val` gets called after the frame has been taken from the stack but before the locals have been deallocated.
+    ///
+    /// [`M::before_stack_pop`] and [`M::after_stack_pop`] are called by this function
+    /// automatically.
+    ///
+    /// The high-level version of this is `return_from_current_stack_frame`.
+    ///
+    /// [`M::before_stack_pop`]: Machine::before_stack_pop
+    /// [`M::after_stack_pop`]: Machine::after_stack_pop
     pub(super) fn pop_stack_frame_raw(
         &mut self,
-    ) -> InterpResult<'tcx, Frame<'tcx, M::Provenance, M::FrameExtra>> {
+        unwinding: bool,
+        copy_ret_val: impl FnOnce(&mut Self, &PlaceTy<'tcx, M::Provenance>) -> InterpResult<'tcx>,
+    ) -> InterpResult<'tcx, StackPopInfo<'tcx, M::Provenance>> {
         M::before_stack_pop(self)?;
         let frame =
             self.stack_mut().pop().expect("tried to pop a stack frame, but there were none");
-        interp_ok(frame)
+
+        // Copy return value (unless we are unwinding).
+        if !unwinding {
+            copy_ret_val(self, &frame.return_place)?;
         }
 
-    /// Deallocate local variables in the stack frame, and invoke `after_stack_pop`.
-    pub(super) fn cleanup_stack_frame(
-        &mut self,
-        unwinding: bool,
-        frame: Frame<'tcx, M::Provenance, M::FrameExtra>,
-    ) -> InterpResult<'tcx, ReturnAction> {
         let return_cont = frame.return_cont;
+        let return_place = frame.return_place.clone();
 
         // Cleanup: deallocate locals.
         // Usually we want to clean up (deallocate locals), but in a few rare cases we don't.
@@ -441,7 +455,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             ReturnContinuation::Stop { cleanup, .. } => cleanup,
         };
 
-        if cleanup {
+        let return_action = if cleanup {
             for local in &frame.locals {
                 self.deallocate_local(local.value)?;
             }
@@ -452,11 +466,13 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             // Call the machine hook, which determines the next steps.
             let return_action = M::after_stack_pop(self, frame, unwinding)?;
             assert_ne!(return_action, ReturnAction::NoCleanup);
-            interp_ok(return_action)
+            return_action
         } else {
             // We also skip the machine hook when there's no cleanup. This not a real "pop" anyway.
-            interp_ok(ReturnAction::NoCleanup)
-        }
+            ReturnAction::NoCleanup
+        };
+
+        interp_ok(StackPopInfo { return_action, return_cont, return_place })
     }
 
     /// In the current stack frame, mark all locals as live that are not arguments and don't have
@@ -639,7 +655,7 @@ impl<'a, 'tcx: 'a, M: Machine<'tcx>> InterpCx<'tcx, M> {
             let (_idx, callee_abi) = callee_abis.next().unwrap();
             assert!(self.check_argument_compat(caller_abi, callee_abi)?);
             // FIXME: do we have to worry about in-place argument passing?
-            let op = fn_arg.copy_fn_arg();
+            let op = self.copy_fn_arg(fn_arg);
             let mplace = self.allocate(op.layout, MemoryKind::Stack)?;
             self.copy_op(&op, &mplace)?;
 

compiler/rustc_const_eval/src/interpret/step.rs

@@ -249,6 +249,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 self.write_immediate(*val, &dest)?;
             }
 
+            ShallowInitBox(ref operand, _) => {
+                let src = self.eval_operand(operand, None)?;
+                let v = self.read_immediate(&src)?;
+                self.write_immediate(*v, &dest)?;
+            }
+
             Cast(cast_kind, ref operand, cast_ty) => {
                 let src = self.eval_operand(operand, None)?;
                 let cast_ty =

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -647,8 +647,13 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
                 }
             } else {
                 // This is not CTFE, so it's Miri with recursive checking.
-                // FIXME: should we also `UnsafeCell` behind shared references? Currently that is not
+                // FIXME: we do *not* check behind boxes, since creating a new box first creates it uninitialized
+                // and then puts the value in there, so briefly we have a box with uninit contents.
+                // FIXME: should we also skip `UnsafeCell` behind shared references? Currently that is not
                 // needed since validation reads bypass Stacked Borrows and data race checks.
+                if matches!(ptr_kind, PointerKind::Box) {
+                    return interp_ok(());
+                }
             }
             let path = &self.path;
             ref_tracking.track(place, || {

compiler/rustc_expand/src/base.rs

@@ -2,11 +2,12 @@ use std::any::Any;
 use std::default::Default;
 use std::iter;
 use std::path::Component::Prefix;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::rc::Rc;
 use std::sync::Arc;
 
 use rustc_ast::attr::MarkedAttrs;
+use rustc_ast::token::MetaVarKind;
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::visit::{AssocCtxt, Visitor};
 use rustc_ast::{self as ast, AttrVec, Attribute, HasAttrs, Item, NodeId, PatKind, Safety};
@@ -21,14 +22,14 @@ use rustc_hir::limit::Limit;
 use rustc_hir::{Stability, find_attr};
 use rustc_lint_defs::RegisteredTools;
 use rustc_parse::MACRO_ARGUMENTS;
-use rustc_parse::parser::Parser;
+use rustc_parse::parser::{AllowConstBlockItems, ForceCollect, Parser};
 use rustc_session::Session;
 use rustc_session::parse::ParseSess;
 use rustc_span::def_id::{CrateNum, DefId, LocalDefId};
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId, MacroKind};
 use rustc_span::source_map::SourceMap;
-use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw};
+use rustc_span::{DUMMY_SP, FileName, Ident, Span, Symbol, kw, sym};
 use smallvec::{SmallVec, smallvec};
 use thin_vec::ThinVec;
 
@@ -1420,3 +1421,80 @@ pub fn resolve_path(sess: &Session, path: impl Into<PathBuf>, span: Span) -> PRe
         }
     }
 }
+
+/// If this item looks like a specific enums from `rental`, emit a fatal error.
+/// See #73345 and #83125 for more details.
+/// FIXME(#73933): Remove this eventually.
+fn pretty_printing_compatibility_hack(item: &Item, psess: &ParseSess) {
+    if let ast::ItemKind::Enum(ident, _, enum_def) = &item.kind
+        && ident.name == sym::ProceduralMasqueradeDummyType
+        && let [variant] = &*enum_def.variants
+        && variant.ident.name == sym::Input
+        && let FileName::Real(real) = psess.source_map().span_to_filename(ident.span)
+        && let Some(c) = real
+            .local_path()
+            .unwrap_or(Path::new(""))
+            .components()
+            .flat_map(|c| c.as_os_str().to_str())
+            .find(|c| c.starts_with("rental") || c.starts_with("allsorts-rental"))
+    {
+        let crate_matches = if c.starts_with("allsorts-rental") {
+            true
+        } else {
+            let mut version = c.trim_start_matches("rental-").split('.');
+            version.next() == Some("0")
+                && version.next() == Some("5")
+                && version.next().and_then(|c| c.parse::<u32>().ok()).is_some_and(|v| v < 6)
+        };
+
+        if crate_matches {
+            psess.dcx().emit_fatal(errors::ProcMacroBackCompat {
+                crate_name: "rental".to_string(),
+                fixed_version: "0.5.6".to_string(),
+            });
+        }
+    }
+}
+
+pub(crate) fn ann_pretty_printing_compatibility_hack(ann: &Annotatable, psess: &ParseSess) {
+    let item = match ann {
+        Annotatable::Item(item) => item,
+        Annotatable::Stmt(stmt) => match &stmt.kind {
+            ast::StmtKind::Item(item) => item,
+            _ => return,
+        },
+        _ => return,
+    };
+    pretty_printing_compatibility_hack(item, psess)
+}
+
+pub(crate) fn stream_pretty_printing_compatibility_hack(
+    kind: MetaVarKind,
+    stream: &TokenStream,
+    psess: &ParseSess,
+) {
+    let item = match kind {
+        MetaVarKind::Item => {
+            let mut parser = Parser::new(psess, stream.clone(), None);
+            // No need to collect tokens for this simple check.
+            parser
+                .parse_item(ForceCollect::No, AllowConstBlockItems::No)
+                .expect("failed to reparse item")
+                .expect("an actual item")
+        }
+        MetaVarKind::Stmt => {
+            let mut parser = Parser::new(psess, stream.clone(), None);
+            // No need to collect tokens for this simple check.
+            let stmt = parser
+                .parse_stmt(ForceCollect::No)
+                .expect("failed to reparse")
+                .expect("an actual stmt");
+            match &stmt.kind {
+                ast::StmtKind::Item(item) => item.clone(),
+                _ => return,
+            }
+        }
+        _ => return,
+    };
+    pretty_printing_compatibility_hack(&item, psess)
+}

compiler/rustc_expand/src/errors.rs

@@ -446,6 +446,18 @@ pub(crate) struct GlobDelegationTraitlessQpath {
     pub span: Span,
 }
 
+// This used to be the `proc_macro_back_compat` lint (#83125). It was later
+// turned into a hard error.
+#[derive(Diagnostic)]
+#[diag("using an old version of `{$crate_name}`")]
+#[note(
+    "older versions of the `{$crate_name}` crate no longer compile; please update to `{$crate_name}` v{$fixed_version}, or switch to one of the `{$crate_name}` alternatives"
+)]
+pub(crate) struct ProcMacroBackCompat {
+    pub crate_name: String,
+    pub fixed_version: String,
+}
+
 pub(crate) use metavar_exprs::*;
 mod metavar_exprs {
     use super::*;

compiler/rustc_expand/src/proc_macro.rs

@@ -105,6 +105,11 @@ impl MultiItemModifier for DeriveProcMacro {
         // (e.g. `fn foo() { #[derive(Debug)] struct Bar; }`)
         let is_stmt = matches!(item, Annotatable::Stmt(..));
 
+        // We used to have an alternative behaviour for crates that needed it.
+        // We had a lint for a long time, but now we just emit a hard error.
+        // Eventually we might remove the special case hard error check
+        // altogether. See #73345.
+        crate::base::ann_pretty_printing_compatibility_hack(&item, &ecx.sess.psess);
         let input = item.to_tokens();
 
         let invoc_id = ecx.current_expansion.id;

compiler/rustc_expand/src/proc_macro_server.rs

@@ -103,8 +103,8 @@ impl ToInternal<token::LitKind> for LitKind {
     }
 }
 
-impl FromInternal<TokenStream> for Vec<TokenTree<TokenStream, Span, Symbol>> {
-    fn from_internal(stream: TokenStream) -> Self {
+impl FromInternal<(TokenStream, &mut Rustc<'_, '_>)> for Vec<TokenTree<TokenStream, Span, Symbol>> {
+    fn from_internal((stream, rustc): (TokenStream, &mut Rustc<'_, '_>)) -> Self {
         use rustc_ast::token::*;
 
         // Estimate the capacity as `stream.len()` rounded up to the next power
@@ -115,6 +115,22 @@ impl FromInternal<TokenStream> for Vec<TokenTree<TokenStream, Span, Symbol>> {
         while let Some(tree) = iter.next() {
             let (Token { kind, span }, joint) = match tree.clone() {
                 tokenstream::TokenTree::Delimited(span, _, mut delim, mut stream) => {
+                    // We used to have an alternative behaviour for crates that
+                    // needed it: a hack used to pass AST fragments to
+                    // attribute and derive macros as a single nonterminal
+                    // token instead of a token stream. Such token needs to be
+                    // "unwrapped" and not represented as a delimited group. We
+                    // had a lint for a long time, but now we just emit a hard
+                    // error. Eventually we might remove the special case hard
+                    // error check altogether. See #73345.
+                    if let Delimiter::Invisible(InvisibleOrigin::MetaVar(kind)) = delim {
+                        crate::base::stream_pretty_printing_compatibility_hack(
+                            kind,
+                            &stream,
+                            rustc.psess(),
+                        );
+                    }
+
                     // In `mk_delimited` we avoid nesting invisible delimited
                     // of the same `MetaVarKind`. Here we do the same but
                     // ignore the `MetaVarKind` because it is discarded when we
@@ -671,7 +687,7 @@ impl server::Server for Rustc<'_, '_> {
         &mut self,
         stream: Self::TokenStream,
     ) -> Vec<TokenTree<Self::TokenStream, Self::Span, Self::Symbol>> {
-        FromInternal::from_internal(stream)
+        FromInternal::from_internal((stream, self))
     }
 
     fn span_debug(&mut self, span: Self::Span) -> String {

compiler/rustc_feature/src/builtin_attrs.rs

@@ -1208,7 +1208,7 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         rustc_intrinsic_const_stable_indirect, Normal,
         template!(Word), WarnFollowing, EncodeCrossCrate::No,  "this is an internal implementation detail",
     ),
-    rustc_attr!(
+    gated!(
         rustc_allow_const_fn_unstable, Normal,
         template!(Word, List: &["feat1, feat2, ..."]), DuplicatesOk, EncodeCrossCrate::No,
         "rustc_allow_const_fn_unstable side-steps feature gating and stability checks"

compiler/rustc_feature/src/unstable.rs

@@ -287,6 +287,10 @@ declare_features! (
     (internal, panic_runtime, "1.10.0", Some(32837)),
     /// Allows using pattern types.
     (internal, pattern_types, "1.79.0", Some(123646)),
+    /// Allows using `#[rustc_allow_const_fn_unstable]`.
+    /// This is an attribute on `const fn` for the same
+    /// purpose as `#[allow_internal_unstable]`.
+    (internal, rustc_allow_const_fn_unstable, "1.49.0", Some(69399)),
     /// Allows using compiler's own crates.
     (unstable, rustc_private, "1.0.0", Some(27812)),
     /// Allows using internal rustdoc features like `doc(keyword)`.
@@ -489,7 +493,7 @@ declare_features! (
     /// Allows the use of `#[ffi_pure]` on foreign functions.
     (unstable, ffi_pure, "1.45.0", Some(58329)),
     /// Allows marking trait functions as `final` to prevent overriding impls
-    (unstable, final_associated_functions, "CURRENT_RUSTC_VERSION", Some(131179)),
+    (unstable, final_associated_functions, "CURRENT_RUSTC_VERSION", Some(1)),
     /// Controlling the behavior of fmt::Debug
     (unstable, fmt_debug, "1.82.0", Some(129709)),
     /// Allows using `#[align(...)]` on function items

compiler/rustc_incremental/src/persist/clean.rs

@@ -322,7 +322,7 @@ impl<'tcx> CleanVisitor<'tcx> {
         if let Some(def_id) = dep_node.extract_def_id(self.tcx) {
             format!("{:?}({})", dep_node.kind, self.tcx.def_path_str(def_id))
         } else {
-            format!("{:?}({:?})", dep_node.kind, dep_node.key_fingerprint)
+            format!("{:?}({:?})", dep_node.kind, dep_node.hash)
         }
     }
 

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -1,10 +1,10 @@
 //! This module defines the [`DepNode`] type which the compiler uses to represent
 //! nodes in the [dependency graph]. A `DepNode` consists of a [`DepKind`] (which
 //! specifies the kind of thing it represents, like a piece of HIR, MIR, etc.)
-//! and a "key fingerprint", a 128-bit hash value, the exact meaning of which
-//! depends on the node's `DepKind`. Together, the kind and the key fingerprint
+//! and a [`Fingerprint`], a 128-bit hash value, the exact meaning of which
+//! depends on the node's `DepKind`. Together, the kind and the fingerprint
 //! fully identify a dependency node, even across multiple compilation sessions.
-//! In other words, the value of the key fingerprint does not depend on anything
+//! In other words, the value of the fingerprint does not depend on anything
 //! that is specific to a given compilation session, like an unpredictable
 //! interning key (e.g., `NodeId`, `DefId`, `Symbol`) or the numeric value of a
 //! pointer. The concept behind this could be compared to how git commit hashes
@@ -41,9 +41,17 @@
 //!   `DepNode`s could represent global concepts with only one value.
 //! * Whether it is possible, in principle, to reconstruct a query key from a
 //!   given `DepNode`. Many `DepKind`s only require a single `DefId` parameter,
-//!   in which case it is possible to map the node's key fingerprint back to the
+//!   in which case it is possible to map the node's fingerprint back to the
 //!   `DefId` it was computed from. In other cases, too much information gets
-//!   lost when computing a key fingerprint.
+//!   lost during fingerprint computation.
+//!
+//! `make_compile_codegen_unit` and `make_compile_mono_items`, together with
+//! `DepNode::new()`, ensure that only valid `DepNode` instances can be
+//! constructed. For example, the API does not allow for constructing
+//! parameterless `DepNode`s with anything other than a zeroed out fingerprint.
+//! More generally speaking, it relieves the user of the `DepNode` API of
+//! having to know how to compute the expected fingerprint for a given set of
+//! node parameters.
 //!
 //! [dependency graph]: https://rustc-dev-guide.rust-lang.org/query.html
 
@@ -57,7 +65,7 @@ use rustc_hir::definitions::DefPathHash;
 use rustc_macros::{Decodable, Encodable};
 use rustc_span::Symbol;
 
-use super::{KeyFingerprintStyle, SerializedDepNodeIndex};
+use super::{FingerprintStyle, SerializedDepNodeIndex};
 use crate::ich::StableHashingContext;
 use crate::mir::mono::MonoItem;
 use crate::ty::{TyCtxt, tls};
@@ -117,20 +125,10 @@ impl fmt::Debug for DepKind {
     }
 }
 
-/// Combination of a [`DepKind`] and a key fingerprint that uniquely identifies
-/// a node in the dep graph.
 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
 pub struct DepNode {
     pub kind: DepKind,
-
-    /// This is _typically_ a hash of the query key, but sometimes not.
-    ///
-    /// For example, `anon` nodes have a fingerprint that is derived from their
-    /// dependencies instead of a key.
-    ///
-    /// In some cases the key value can be reconstructed from this fingerprint;
-    /// see [`KeyFingerprintStyle`].
-    pub key_fingerprint: PackedFingerprint,
+    pub hash: PackedFingerprint,
 }
 
 impl DepNode {
@@ -138,23 +136,24 @@ impl DepNode {
     /// that the DepNode corresponding to the given DepKind actually
     /// does not require any parameters.
     pub fn new_no_params<'tcx>(tcx: TyCtxt<'tcx>, kind: DepKind) -> DepNode {
-        debug_assert_eq!(tcx.key_fingerprint_style(kind), KeyFingerprintStyle::Unit);
-        DepNode { kind, key_fingerprint: Fingerprint::ZERO.into() }
+        debug_assert_eq!(tcx.fingerprint_style(kind), FingerprintStyle::Unit);
+        DepNode { kind, hash: Fingerprint::ZERO.into() }
     }
 
-    pub fn construct<'tcx, Key>(tcx: TyCtxt<'tcx>, kind: DepKind, key: &Key) -> DepNode
+    pub fn construct<'tcx, Key>(tcx: TyCtxt<'tcx>, kind: DepKind, arg: &Key) -> DepNode
     where
         Key: DepNodeKey<'tcx>,
     {
-        let dep_node = DepNode { kind, key_fingerprint: key.to_fingerprint(tcx).into() };
+        let hash = arg.to_fingerprint(tcx);
+        let dep_node = DepNode { kind, hash: hash.into() };
 
         #[cfg(debug_assertions)]
         {
-            if !tcx.key_fingerprint_style(kind).reconstructible()
+            if !tcx.fingerprint_style(kind).reconstructible()
                 && (tcx.sess.opts.unstable_opts.incremental_info
                     || tcx.sess.opts.unstable_opts.query_dep_graph)
             {
-                tcx.dep_graph.register_dep_node_debug_str(dep_node, || key.to_debug_str(tcx));
+                tcx.dep_graph.register_dep_node_debug_str(dep_node, || arg.to_debug_str(tcx));
             }
         }
 
@@ -169,8 +168,8 @@ impl DepNode {
         def_path_hash: DefPathHash,
         kind: DepKind,
     ) -> Self {
-        debug_assert!(tcx.key_fingerprint_style(kind) == KeyFingerprintStyle::DefPathHash);
-        DepNode { kind, key_fingerprint: def_path_hash.0.into() }
+        debug_assert!(tcx.fingerprint_style(kind) == FingerprintStyle::DefPathHash);
+        DepNode { kind, hash: def_path_hash.0.into() }
     }
 }
 
@@ -185,10 +184,10 @@ impl fmt::Debug for DepNode {
                 } else if let Some(ref s) = tcx.dep_graph.dep_node_debug_str(*self) {
                     write!(f, "{s}")?;
                 } else {
-                    write!(f, "{}", self.key_fingerprint)?;
+                    write!(f, "{}", self.hash)?;
                 }
             } else {
-                write!(f, "{}", self.key_fingerprint)?;
+                write!(f, "{}", self.hash)?;
             }
             Ok(())
         })?;
@@ -199,7 +198,7 @@ impl fmt::Debug for DepNode {
 
 /// Trait for query keys as seen by dependency-node tracking.
 pub trait DepNodeKey<'tcx>: fmt::Debug + Sized {
-    fn key_fingerprint_style() -> KeyFingerprintStyle;
+    fn fingerprint_style() -> FingerprintStyle;
 
     /// This method turns a query key into an opaque `Fingerprint` to be used
     /// in `DepNode`.
@@ -213,7 +212,7 @@ pub trait DepNodeKey<'tcx>: fmt::Debug + Sized {
     /// `fingerprint_style()` is not `FingerprintStyle::Opaque`.
     /// It is always valid to return `None` here, in which case incremental
     /// compilation will treat the query as having changed instead of forcing it.
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self>;
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self>;
 }
 
 // Blanket impl of `DepNodeKey`, which is specialized by other impls elsewhere.
@@ -222,8 +221,8 @@ where
     T: for<'a> HashStable<StableHashingContext<'a>> + fmt::Debug,
 {
     #[inline(always)]
-    default fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::Opaque
+    default fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::Opaque
     }
 
     #[inline(always)]
@@ -244,7 +243,7 @@ where
     }
 
     #[inline(always)]
-    default fn try_recover_key(_: TyCtxt<'tcx>, _: &DepNode) -> Option<Self> {
+    default fn recover(_: TyCtxt<'tcx>, _: &DepNode) -> Option<Self> {
         None
     }
 }
@@ -265,11 +264,10 @@ pub struct DepKindVTable<'tcx> {
     /// cached within one compiler invocation.
     pub is_eval_always: bool,
 
-    /// Indicates whether and how a query key can be reconstructed from the
-    /// key fingerprint of a dep node with this [`DepKind`].
+    /// Indicates whether and how the query key can be recovered from its hashed fingerprint.
     ///
     /// The [`DepNodeKey`] trait determines the fingerprint style for each key type.
-    pub key_fingerprint_style: KeyFingerprintStyle,
+    pub fingerprint_style: FingerprintStyle,
 
     /// The red/green evaluation system will try to mark a specific DepNode in the
     /// dependency graph as green by recursively trying to mark the dependencies of
@@ -281,7 +279,7 @@ pub struct DepKindVTable<'tcx> {
     /// `force_from_dep_node()` implements.
     ///
     /// In the general case, a `DepNode` consists of a `DepKind` and an opaque
-    /// "key fingerprint" that will uniquely identify the node. This key fingerprint
+    /// GUID/fingerprint that will uniquely identify the node. This GUID/fingerprint
     /// is usually constructed by computing a stable hash of the query-key that the
     /// `DepNode` corresponds to. Consequently, it is not in general possible to go
     /// back from hash to query-key (since hash functions are not reversible). For
@@ -295,7 +293,7 @@ pub struct DepKindVTable<'tcx> {
     /// Now, if `force_from_dep_node()` would always fail, it would be pretty useless.
     /// Fortunately, we can use some contextual information that will allow us to
     /// reconstruct query-keys for certain kinds of `DepNode`s. In particular, we
-    /// enforce by construction that the key fingerprint of certain `DepNode`s is a
+    /// enforce by construction that the GUID/fingerprint of certain `DepNode`s is a
     /// valid `DefPathHash`. Since we also always build a huge table that maps every
     /// `DefPathHash` in the current codebase to the corresponding `DefId`, we have
     /// everything we need to re-run the query.
@@ -303,7 +301,7 @@ pub struct DepKindVTable<'tcx> {
     /// Take the `mir_promoted` query as an example. Like many other queries, it
     /// just has a single parameter: the `DefId` of the item it will compute the
     /// validated MIR for. Now, when we call `force_from_dep_node()` on a `DepNode`
-    /// with kind `mir_promoted`, we know that the key fingerprint of the `DepNode`
+    /// with kind `MirValidated`, we know that the GUID/fingerprint of the `DepNode`
     /// is actually a `DefPathHash`, and can therefore just look up the corresponding
     /// `DefId` in `tcx.def_path_hash_to_def_id`.
     pub force_from_dep_node: Option<
@@ -474,8 +472,8 @@ impl DepNode {
     /// refers to something from the previous compilation session that
     /// has been removed.
     pub fn extract_def_id(&self, tcx: TyCtxt<'_>) -> Option<DefId> {
-        if tcx.key_fingerprint_style(self.kind) == KeyFingerprintStyle::DefPathHash {
-            tcx.def_path_hash_to_def_id(DefPathHash(self.key_fingerprint.into()))
+        if tcx.fingerprint_style(self.kind) == FingerprintStyle::DefPathHash {
+            tcx.def_path_hash_to_def_id(DefPathHash(self.hash.into()))
         } else {
             None
         }
@@ -488,10 +486,10 @@ impl DepNode {
     ) -> Result<DepNode, ()> {
         let kind = dep_kind_from_label_string(label)?;
 
-        match tcx.key_fingerprint_style(kind) {
-            KeyFingerprintStyle::Opaque | KeyFingerprintStyle::HirId => Err(()),
-            KeyFingerprintStyle::Unit => Ok(DepNode::new_no_params(tcx, kind)),
-            KeyFingerprintStyle::DefPathHash => {
+        match tcx.fingerprint_style(kind) {
+            FingerprintStyle::Opaque | FingerprintStyle::HirId => Err(()),
+            FingerprintStyle::Unit => Ok(DepNode::new_no_params(tcx, kind)),
+            FingerprintStyle::DefPathHash => {
                 Ok(DepNode::from_def_path_hash(tcx, def_path_hash, kind))
             }
         }

compiler/rustc_middle/src/dep_graph/dep_node_key.rs

@@ -3,13 +3,13 @@ use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE, LocalDefId, LocalModDefId,
 use rustc_hir::definitions::DefPathHash;
 use rustc_hir::{HirId, ItemLocalId, OwnerId};
 
-use crate::dep_graph::{DepNode, DepNodeKey, KeyFingerprintStyle};
+use crate::dep_graph::{DepNode, DepNodeKey, FingerprintStyle};
 use crate::ty::TyCtxt;
 
 impl<'tcx> DepNodeKey<'tcx> for () {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::Unit
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::Unit
     }
 
     #[inline(always)]
@@ -18,15 +18,15 @@ impl<'tcx> DepNodeKey<'tcx> for () {
     }
 
     #[inline(always)]
-    fn try_recover_key(_: TyCtxt<'tcx>, _: &DepNode) -> Option<Self> {
+    fn recover(_: TyCtxt<'tcx>, _: &DepNode) -> Option<Self> {
         Some(())
     }
 }
 
 impl<'tcx> DepNodeKey<'tcx> for DefId {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::DefPathHash
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::DefPathHash
     }
 
     #[inline(always)]
@@ -40,15 +40,15 @@ impl<'tcx> DepNodeKey<'tcx> for DefId {
     }
 
     #[inline(always)]
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
         dep_node.extract_def_id(tcx)
     }
 }
 
 impl<'tcx> DepNodeKey<'tcx> for LocalDefId {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::DefPathHash
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::DefPathHash
     }
 
     #[inline(always)]
@@ -62,15 +62,15 @@ impl<'tcx> DepNodeKey<'tcx> for LocalDefId {
     }
 
     #[inline(always)]
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
         dep_node.extract_def_id(tcx).map(|id| id.expect_local())
     }
 }
 
 impl<'tcx> DepNodeKey<'tcx> for OwnerId {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::DefPathHash
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::DefPathHash
     }
 
     #[inline(always)]
@@ -84,15 +84,15 @@ impl<'tcx> DepNodeKey<'tcx> for OwnerId {
     }
 
     #[inline(always)]
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
         dep_node.extract_def_id(tcx).map(|id| OwnerId { def_id: id.expect_local() })
     }
 }
 
 impl<'tcx> DepNodeKey<'tcx> for CrateNum {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::DefPathHash
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::DefPathHash
     }
 
     #[inline(always)]
@@ -107,15 +107,15 @@ impl<'tcx> DepNodeKey<'tcx> for CrateNum {
     }
 
     #[inline(always)]
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
         dep_node.extract_def_id(tcx).map(|id| id.krate)
     }
 }
 
 impl<'tcx> DepNodeKey<'tcx> for (DefId, DefId) {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::Opaque
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::Opaque
     }
 
     // We actually would not need to specialize the implementation of this
@@ -141,8 +141,8 @@ impl<'tcx> DepNodeKey<'tcx> for (DefId, DefId) {
 
 impl<'tcx> DepNodeKey<'tcx> for HirId {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::HirId
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::HirId
     }
 
     // We actually would not need to specialize the implementation of this
@@ -166,9 +166,9 @@ impl<'tcx> DepNodeKey<'tcx> for HirId {
     }
 
     #[inline(always)]
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
-        if tcx.key_fingerprint_style(dep_node.kind) == KeyFingerprintStyle::HirId {
-            let (local_hash, local_id) = Fingerprint::from(dep_node.key_fingerprint).split();
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+        if tcx.fingerprint_style(dep_node.kind) == FingerprintStyle::HirId {
+            let (local_hash, local_id) = Fingerprint::from(dep_node.hash).split();
             let def_path_hash = DefPathHash::new(tcx.stable_crate_id(LOCAL_CRATE), local_hash);
             let def_id = tcx.def_path_hash_to_def_id(def_path_hash)?.expect_local();
             let local_id = local_id
@@ -184,8 +184,8 @@ impl<'tcx> DepNodeKey<'tcx> for HirId {
 
 impl<'tcx> DepNodeKey<'tcx> for ModDefId {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::DefPathHash
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::DefPathHash
     }
 
     #[inline(always)]
@@ -199,15 +199,15 @@ impl<'tcx> DepNodeKey<'tcx> for ModDefId {
     }
 
     #[inline(always)]
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
-        DefId::try_recover_key(tcx, dep_node).map(ModDefId::new_unchecked)
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+        DefId::recover(tcx, dep_node).map(ModDefId::new_unchecked)
     }
 }
 
 impl<'tcx> DepNodeKey<'tcx> for LocalModDefId {
     #[inline(always)]
-    fn key_fingerprint_style() -> KeyFingerprintStyle {
-        KeyFingerprintStyle::DefPathHash
+    fn fingerprint_style() -> FingerprintStyle {
+        FingerprintStyle::DefPathHash
     }
 
     #[inline(always)]
@@ -221,7 +221,7 @@ impl<'tcx> DepNodeKey<'tcx> for LocalModDefId {
     }
 
     #[inline(always)]
-    fn try_recover_key(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
-        LocalDefId::try_recover_key(tcx, dep_node).map(LocalModDefId::new_unchecked)
+    fn recover(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> Option<Self> {
+        LocalDefId::recover(tcx, dep_node).map(LocalModDefId::new_unchecked)
     }
 }

compiler/rustc_middle/src/dep_graph/graph.rs

@@ -142,17 +142,15 @@ impl DepGraph {
 
         // Instantiate a node with zero dependencies only once for anonymous queries.
         let _green_node_index = current.alloc_new_node(
-            DepNode { kind: DepKind::ANON_ZERO_DEPS, key_fingerprint: current.anon_id_seed.into() },
+            DepNode { kind: DepKind::ANON_ZERO_DEPS, hash: current.anon_id_seed.into() },
             EdgesVec::new(),
             Fingerprint::ZERO,
         );
         assert_eq!(_green_node_index, DepNodeIndex::SINGLETON_ZERO_DEPS_ANON_NODE);
 
-        // Create a single always-red node, with no dependencies of its own.
-        // Other nodes can use the always-red node as a fake dependency, to
-        // ensure that their dependency list will never be all-green.
+        // Instantiate a dependy-less red node only once for anonymous queries.
         let red_node_index = current.alloc_new_node(
-            DepNode { kind: DepKind::RED, key_fingerprint: Fingerprint::ZERO.into() },
+            DepNode { kind: DepKind::RED, hash: Fingerprint::ZERO.into() },
             EdgesVec::new(),
             Fingerprint::ZERO,
         );
@@ -420,7 +418,7 @@ impl DepGraphData {
                     // Fingerprint::combine() is faster than sending Fingerprint
                     // through the StableHasher (at least as long as StableHasher
                     // is so slow).
-                    key_fingerprint: self.current.anon_id_seed.combine(hasher.finish()).into(),
+                    hash: self.current.anon_id_seed.combine(hasher.finish()).into(),
                 };
 
                 // The DepNodes generated by the process above are not unique. 2 queries could
@@ -587,7 +585,7 @@ impl DepGraph {
                         data.current.record_edge(
                             dep_node_index,
                             node,
-                            data.prev_value_fingerprint_of(prev_index),
+                            data.prev_fingerprint_of(prev_index),
                         );
                     }
 
@@ -660,8 +658,8 @@ impl DepGraphData {
     }
 
     #[inline]
-    pub fn prev_value_fingerprint_of(&self, prev_index: SerializedDepNodeIndex) -> Fingerprint {
-        self.previous.value_fingerprint_for_index(prev_index)
+    pub fn prev_fingerprint_of(&self, prev_index: SerializedDepNodeIndex) -> Fingerprint {
+        self.previous.fingerprint_by_index(prev_index)
     }
 
     #[inline]
@@ -681,7 +679,7 @@ impl DepGraphData {
         let dep_node_index = self.current.encoder.send_new(
             DepNode {
                 kind: DepKind::SIDE_EFFECT,
-                key_fingerprint: PackedFingerprint::from(Fingerprint::ZERO),
+                hash: PackedFingerprint::from(Fingerprint::ZERO),
             },
             Fingerprint::ZERO,
             // We want the side effect node to always be red so it will be forced and emit the
@@ -714,7 +712,7 @@ impl DepGraphData {
                 &self.colors,
                 DepNode {
                     kind: DepKind::SIDE_EFFECT,
-                    key_fingerprint: PackedFingerprint::from(Fingerprint::ZERO),
+                    hash: PackedFingerprint::from(Fingerprint::ZERO),
                 },
                 Fingerprint::ZERO,
                 std::iter::once(DepNodeIndex::FOREVER_RED_NODE).collect(),
@@ -729,12 +727,12 @@ impl DepGraphData {
         &self,
         key: DepNode,
         edges: EdgesVec,
-        value_fingerprint: Option<Fingerprint>,
+        fingerprint: Option<Fingerprint>,
     ) -> DepNodeIndex {
         if let Some(prev_index) = self.previous.node_to_index_opt(&key) {
             // Determine the color and index of the new `DepNode`.
-            let is_green = if let Some(value_fingerprint) = value_fingerprint {
-                if value_fingerprint == self.previous.value_fingerprint_for_index(prev_index) {
+            let is_green = if let Some(fingerprint) = fingerprint {
+                if fingerprint == self.previous.fingerprint_by_index(prev_index) {
                     // This is a green node: it existed in the previous compilation,
                     // its query was re-executed, and it has the same result as before.
                     true
@@ -751,22 +749,22 @@ impl DepGraphData {
                 false
             };
 
-            let value_fingerprint = value_fingerprint.unwrap_or(Fingerprint::ZERO);
+            let fingerprint = fingerprint.unwrap_or(Fingerprint::ZERO);
 
             let dep_node_index = self.current.encoder.send_and_color(
                 prev_index,
                 &self.colors,
                 key,
-                value_fingerprint,
+                fingerprint,
                 edges,
                 is_green,
             );
 
-            self.current.record_node(dep_node_index, key, value_fingerprint);
+            self.current.record_node(dep_node_index, key, fingerprint);
 
             dep_node_index
         } else {
-            self.current.alloc_new_node(key, edges, value_fingerprint.unwrap_or(Fingerprint::ZERO))
+            self.current.alloc_new_node(key, edges, fingerprint.unwrap_or(Fingerprint::ZERO))
         }
     }
 
@@ -783,7 +781,7 @@ impl DepGraphData {
             self.current.record_edge(
                 dep_node_index,
                 *self.previous.index_to_node(prev_index),
-                self.previous.value_fingerprint_for_index(prev_index),
+                self.previous.fingerprint_by_index(prev_index),
             );
         }
 
@@ -927,7 +925,7 @@ impl DepGraphData {
         if !tcx.is_eval_always(dep_dep_node.kind) {
             debug!(
                 "state of dependency {:?} ({}) is unknown, trying to mark it green",
-                dep_dep_node, dep_dep_node.key_fingerprint,
+                dep_dep_node, dep_dep_node.hash,
             );
 
             let node_index = self.try_mark_previous_green(tcx, parent_dep_node_index, Some(frame));
@@ -1156,10 +1154,10 @@ pub(super) struct CurrentDepGraph {
     encoder: GraphEncoder,
     anon_node_to_index: ShardedHashMap<DepNode, DepNodeIndex>,
 
-    /// This is used to verify that value fingerprints do not change between the
-    /// creation of a node and its recomputation.
+    /// This is used to verify that fingerprints do not change between the creation of a node
+    /// and its recomputation.
     #[cfg(debug_assertions)]
-    value_fingerprints: Lock<IndexVec<DepNodeIndex, Option<Fingerprint>>>,
+    fingerprints: Lock<IndexVec<DepNodeIndex, Option<Fingerprint>>>,
 
     /// Used to trap when a specific edge is added to the graph.
     /// This is used for debug purposes and is only active with `debug_assertions`.
@@ -1226,7 +1224,7 @@ impl CurrentDepGraph {
             #[cfg(debug_assertions)]
             forbidden_edge,
             #[cfg(debug_assertions)]
-            value_fingerprints: Lock::new(IndexVec::from_elem_n(None, new_node_count_estimate)),
+            fingerprints: Lock::new(IndexVec::from_elem_n(None, new_node_count_estimate)),
             nodes_in_current_session: new_node_dbg.then(|| {
                 Lock::new(FxHashMap::with_capacity_and_hasher(
                     new_node_count_estimate,
@@ -1239,20 +1237,12 @@ impl CurrentDepGraph {
     }
 
     #[cfg(debug_assertions)]
-    fn record_edge(
-        &self,
-        dep_node_index: DepNodeIndex,
-        key: DepNode,
-        value_fingerprint: Fingerprint,
-    ) {
+    fn record_edge(&self, dep_node_index: DepNodeIndex, key: DepNode, fingerprint: Fingerprint) {
         if let Some(forbidden_edge) = &self.forbidden_edge {
             forbidden_edge.index_to_node.lock().insert(dep_node_index, key);
         }
-        let prior_value_fingerprint = *self
-            .value_fingerprints
-            .lock()
-            .get_or_insert_with(dep_node_index, || value_fingerprint);
-        assert_eq!(prior_value_fingerprint, value_fingerprint, "Unstable fingerprints for {key:?}");
+        let previous = *self.fingerprints.lock().get_or_insert_with(dep_node_index, || fingerprint);
+        assert_eq!(previous, fingerprint, "Unstable fingerprints for {:?}", key);
     }
 
     #[inline(always)]
@@ -1260,10 +1250,10 @@ impl CurrentDepGraph {
         &self,
         dep_node_index: DepNodeIndex,
         key: DepNode,
-        _value_fingerprint: Fingerprint,
+        _current_fingerprint: Fingerprint,
     ) {
         #[cfg(debug_assertions)]
-        self.record_edge(dep_node_index, key, _value_fingerprint);
+        self.record_edge(dep_node_index, key, _current_fingerprint);
 
         if let Some(ref nodes_in_current_session) = self.nodes_in_current_session {
             outline(|| {
@@ -1281,11 +1271,11 @@ impl CurrentDepGraph {
         &self,
         key: DepNode,
         edges: EdgesVec,
-        value_fingerprint: Fingerprint,
+        current_fingerprint: Fingerprint,
     ) -> DepNodeIndex {
-        let dep_node_index = self.encoder.send_new(key, value_fingerprint, edges);
+        let dep_node_index = self.encoder.send_new(key, current_fingerprint, edges);
 
-        self.record_node(dep_node_index, key, value_fingerprint);
+        self.record_node(dep_node_index, key, current_fingerprint);
 
         dep_node_index
     }

compiler/rustc_middle/src/dep_graph/mod.rs

@@ -30,7 +30,7 @@ mod serialized;
 /// This is mainly for determining whether and how we can reconstruct a key
 /// from the fingerprint.
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
-pub enum KeyFingerprintStyle {
+pub enum FingerprintStyle {
     /// The fingerprint is actually a DefPathHash.
     DefPathHash,
     /// The fingerprint is actually a HirId.
@@ -41,14 +41,14 @@ pub enum KeyFingerprintStyle {
     Opaque,
 }
 
-impl KeyFingerprintStyle {
+impl FingerprintStyle {
     #[inline]
     pub const fn reconstructible(self) -> bool {
         match self {
-            KeyFingerprintStyle::DefPathHash
-            | KeyFingerprintStyle::Unit
-            | KeyFingerprintStyle::HirId => true,
-            KeyFingerprintStyle::Opaque => false,
+            FingerprintStyle::DefPathHash | FingerprintStyle::Unit | FingerprintStyle::HirId => {
+                true
+            }
+            FingerprintStyle::Opaque => false,
         }
     }
 }
@@ -86,8 +86,8 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     #[inline(always)]
-    pub fn key_fingerprint_style(self, kind: DepKind) -> KeyFingerprintStyle {
-        self.dep_kind_vtable(kind).key_fingerprint_style
+    pub fn fingerprint_style(self, kind: DepKind) -> FingerprintStyle {
+        self.dep_kind_vtable(kind).fingerprint_style
     }
 
     /// Try to force a dep node to execute and see if it's green.

compiler/rustc_middle/src/dep_graph/serialized.rs

@@ -90,13 +90,9 @@ const DEP_NODE_WIDTH_BITS: usize = DEP_NODE_SIZE / 2;
 pub struct SerializedDepGraph {
     /// The set of all DepNodes in the graph
     nodes: IndexVec<SerializedDepNodeIndex, DepNode>,
-    /// A value fingerprint associated with each [`DepNode`] in [`Self::nodes`],
-    /// typically a hash of the value returned by the node's query in the
-    /// previous incremental-compilation session.
-    ///
-    /// Some nodes don't have a meaningful value hash (e.g. queries with `no_hash`),
-    /// so they store a dummy value here instead (e.g. [`Fingerprint::ZERO`]).
-    value_fingerprints: IndexVec<SerializedDepNodeIndex, Fingerprint>,
+    /// The set of all Fingerprints in the graph. Each Fingerprint corresponds to
+    /// the DepNode at the same index in the nodes vector.
+    fingerprints: IndexVec<SerializedDepNodeIndex, Fingerprint>,
     /// For each DepNode, stores the list of edges originating from that
     /// DepNode. Encoded as a [start, end) pair indexing into edge_list_data,
     /// which holds the actual DepNodeIndices of the target nodes.
@@ -104,8 +100,8 @@ pub struct SerializedDepGraph {
     /// A flattened list of all edge targets in the graph, stored in the same
     /// varint encoding that we use on disk. Edge sources are implicit in edge_list_indices.
     edge_list_data: Vec<u8>,
-    /// For each dep kind, stores a map from key fingerprints back to the index
-    /// of the corresponding node. This is the inverse of `nodes`.
+    /// Stores a map from fingerprints to nodes per dep node kind.
+    /// This is the reciprocal of `nodes`.
     index: Vec<UnhashMap<PackedFingerprint, SerializedDepNodeIndex>>,
     /// The number of previous compilation sessions. This is used to generate
     /// unique anon dep nodes per session.
@@ -142,15 +138,12 @@ impl SerializedDepGraph {
 
     #[inline]
     pub fn node_to_index_opt(&self, dep_node: &DepNode) -> Option<SerializedDepNodeIndex> {
-        self.index.get(dep_node.kind.as_usize())?.get(&dep_node.key_fingerprint).copied()
+        self.index.get(dep_node.kind.as_usize())?.get(&dep_node.hash).cloned()
     }
 
     #[inline]
-    pub fn value_fingerprint_for_index(
-        &self,
-        dep_node_index: SerializedDepNodeIndex,
-    ) -> Fingerprint {
-        self.value_fingerprints[dep_node_index]
+    pub fn fingerprint_by_index(&self, dep_node_index: SerializedDepNodeIndex) -> Fingerprint {
+        self.fingerprints[dep_node_index]
     }
 
     #[inline]
@@ -219,13 +212,10 @@ impl SerializedDepGraph {
         let graph_bytes = d.len() - (3 * IntEncodedWithFixedSize::ENCODED_SIZE) - d.position();
 
         let mut nodes = IndexVec::from_elem_n(
-            DepNode {
-                kind: DepKind::NULL,
-                key_fingerprint: PackedFingerprint::from(Fingerprint::ZERO),
-            },
+            DepNode { kind: DepKind::NULL, hash: PackedFingerprint::from(Fingerprint::ZERO) },
             node_max,
         );
-        let mut value_fingerprints = IndexVec::from_elem_n(Fingerprint::ZERO, node_max);
+        let mut fingerprints = IndexVec::from_elem_n(Fingerprint::ZERO, node_max);
         let mut edge_list_indices =
             IndexVec::from_elem_n(EdgeHeader { repr: 0, num_edges: 0 }, node_max);
 
@@ -253,7 +243,7 @@ impl SerializedDepGraph {
             assert!(node_header.node().kind != DepKind::NULL && node.kind == DepKind::NULL);
             *node = node_header.node();
 
-            value_fingerprints[index] = node_header.value_fingerprint();
+            fingerprints[index] = node_header.fingerprint();
 
             // If the length of this node's edge list is small, the length is stored in the header.
             // If it is not, we fall back to another decoder call.
@@ -285,7 +275,7 @@ impl SerializedDepGraph {
         let session_count = d.read_u64();
 
         for (idx, node) in nodes.iter_enumerated() {
-            if index[node.kind.as_usize()].insert(node.key_fingerprint, idx).is_some() {
+            if index[node.kind.as_usize()].insert(node.hash, idx).is_some() {
                 // Empty nodes and side effect nodes can have duplicates
                 if node.kind != DepKind::NULL && node.kind != DepKind::SIDE_EFFECT {
                     let name = node.kind.name();
@@ -301,7 +291,7 @@ impl SerializedDepGraph {
 
         Arc::new(SerializedDepGraph {
             nodes,
-            value_fingerprints,
+            fingerprints,
             edge_list_indices,
             edge_list_data,
             index,
@@ -313,8 +303,8 @@ impl SerializedDepGraph {
 /// A packed representation of all the fixed-size fields in a `NodeInfo`.
 ///
 /// This stores in one byte array:
-/// * The value `Fingerprint` in the `NodeInfo`
-/// * The key `Fingerprint` in `DepNode` that is in this `NodeInfo`
+/// * The `Fingerprint` in the `NodeInfo`
+/// * The `Fingerprint` in `DepNode` that is in this `NodeInfo`
 /// * The `DepKind`'s discriminant (a u16, but not all bits are used...)
 /// * The byte width of the encoded edges for this node
 /// * In whatever bits remain, the length of the edge list for this node, if it fits
@@ -333,8 +323,8 @@ struct Unpacked {
     bytes_per_index: usize,
     kind: DepKind,
     index: SerializedDepNodeIndex,
-    key_fingerprint: PackedFingerprint,
-    value_fingerprint: Fingerprint,
+    hash: PackedFingerprint,
+    fingerprint: Fingerprint,
 }
 
 // Bit fields, where
@@ -355,7 +345,7 @@ impl SerializedNodeHeader {
     fn new(
         node: &DepNode,
         index: DepNodeIndex,
-        value_fingerprint: Fingerprint,
+        fingerprint: Fingerprint,
         edge_max_index: u32,
         edge_count: usize,
     ) -> Self {
@@ -373,19 +363,19 @@ impl SerializedNodeHeader {
             head |= (edge_count as u16 + 1) << (Self::KIND_BITS + Self::WIDTH_BITS);
         }
 
-        let hash: Fingerprint = node.key_fingerprint.into();
+        let hash: Fingerprint = node.hash.into();
 
         // Using half-open ranges ensures an unconditional panic if we get the magic numbers wrong.
         let mut bytes = [0u8; 38];
         bytes[..2].copy_from_slice(&head.to_le_bytes());
         bytes[2..6].copy_from_slice(&index.as_u32().to_le_bytes());
         bytes[6..22].copy_from_slice(&hash.to_le_bytes());
-        bytes[22..].copy_from_slice(&value_fingerprint.to_le_bytes());
+        bytes[22..].copy_from_slice(&fingerprint.to_le_bytes());
 
         #[cfg(debug_assertions)]
         {
             let res = Self { bytes };
-            assert_eq!(value_fingerprint, res.value_fingerprint());
+            assert_eq!(fingerprint, res.fingerprint());
             assert_eq!(*node, res.node());
             if let Some(len) = res.len() {
                 assert_eq!(edge_count, len as usize);
@@ -398,8 +388,8 @@ impl SerializedNodeHeader {
     fn unpack(&self) -> Unpacked {
         let head = u16::from_le_bytes(self.bytes[..2].try_into().unwrap());
         let index = u32::from_le_bytes(self.bytes[2..6].try_into().unwrap());
-        let key_fingerprint = self.bytes[6..22].try_into().unwrap();
-        let value_fingerprint = self.bytes[22..].try_into().unwrap();
+        let hash = self.bytes[6..22].try_into().unwrap();
+        let fingerprint = self.bytes[22..].try_into().unwrap();
 
         let kind = head & mask(Self::KIND_BITS) as u16;
         let bytes_per_index = (head >> Self::KIND_BITS) & mask(Self::WIDTH_BITS) as u16;
@@ -410,8 +400,8 @@ impl SerializedNodeHeader {
             bytes_per_index: bytes_per_index as usize + 1,
             kind: DepKind::new(kind),
             index: SerializedDepNodeIndex::from_u32(index),
-            key_fingerprint: Fingerprint::from_le_bytes(key_fingerprint).into(),
-            value_fingerprint: Fingerprint::from_le_bytes(value_fingerprint),
+            hash: Fingerprint::from_le_bytes(hash).into(),
+            fingerprint: Fingerprint::from_le_bytes(fingerprint),
         }
     }
 
@@ -431,14 +421,14 @@ impl SerializedNodeHeader {
     }
 
     #[inline]
-    fn value_fingerprint(&self) -> Fingerprint {
-        self.unpack().value_fingerprint
+    fn fingerprint(&self) -> Fingerprint {
+        self.unpack().fingerprint
     }
 
     #[inline]
     fn node(&self) -> DepNode {
-        let Unpacked { kind, key_fingerprint, .. } = self.unpack();
-        DepNode { kind, key_fingerprint }
+        let Unpacked { kind, hash, .. } = self.unpack();
+        DepNode { kind, hash }
     }
 
     #[inline]
@@ -453,20 +443,15 @@ impl SerializedNodeHeader {
 #[derive(Debug)]
 struct NodeInfo {
     node: DepNode,
-    value_fingerprint: Fingerprint,
+    fingerprint: Fingerprint,
     edges: EdgesVec,
 }
 
 impl NodeInfo {
     fn encode(&self, e: &mut MemEncoder, index: DepNodeIndex) {
-        let NodeInfo { ref node, value_fingerprint, ref edges } = *self;
-        let header = SerializedNodeHeader::new(
-            node,
-            index,
-            value_fingerprint,
-            edges.max_index(),
-            edges.len(),
-        );
+        let NodeInfo { ref node, fingerprint, ref edges } = *self;
+        let header =
+            SerializedNodeHeader::new(node, index, fingerprint, edges.max_index(), edges.len());
         e.write_array(header.bytes);
 
         if header.len().is_none() {
@@ -491,7 +476,7 @@ impl NodeInfo {
         e: &mut MemEncoder,
         node: &DepNode,
         index: DepNodeIndex,
-        value_fingerprint: Fingerprint,
+        fingerprint: Fingerprint,
         prev_index: SerializedDepNodeIndex,
         colors: &DepNodeColorMap,
         previous: &SerializedDepGraph,
@@ -503,8 +488,7 @@ impl NodeInfo {
         let edge_max =
             edges.clone().map(|i| colors.current(i).unwrap().as_u32()).max().unwrap_or(0);
 
-        let header =
-            SerializedNodeHeader::new(node, index, value_fingerprint, edge_max, edge_count);
+        let header = SerializedNodeHeader::new(node, index, fingerprint, edge_max, edge_count);
         e.write_array(header.bytes);
 
         if header.len().is_none() {
@@ -692,12 +676,12 @@ impl EncoderState {
         local: &mut LocalEncoderState,
     ) {
         let node = self.previous.index_to_node(prev_index);
-        let value_fingerprint = self.previous.value_fingerprint_for_index(prev_index);
+        let fingerprint = self.previous.fingerprint_by_index(prev_index);
         let edge_count = NodeInfo::encode_promoted(
             &mut local.encoder,
             node,
             index,
-            value_fingerprint,
+            fingerprint,
             prev_index,
             colors,
             &self.previous,
@@ -873,11 +857,11 @@ impl GraphEncoder {
     pub(crate) fn send_new(
         &self,
         node: DepNode,
-        value_fingerprint: Fingerprint,
+        fingerprint: Fingerprint,
         edges: EdgesVec,
     ) -> DepNodeIndex {
         let _prof_timer = self.profiler.generic_activity("incr_comp_encode_dep_graph");
-        let node = NodeInfo { node, value_fingerprint, edges };
+        let node = NodeInfo { node, fingerprint, edges };
         let mut local = self.status.local.borrow_mut();
         let index = self.status.next_index(&mut *local);
         self.status.bump_index(&mut *local);
@@ -893,12 +877,12 @@ impl GraphEncoder {
         prev_index: SerializedDepNodeIndex,
         colors: &DepNodeColorMap,
         node: DepNode,
-        value_fingerprint: Fingerprint,
+        fingerprint: Fingerprint,
         edges: EdgesVec,
         is_green: bool,
     ) -> DepNodeIndex {
         let _prof_timer = self.profiler.generic_activity("incr_comp_encode_dep_graph");
-        let node = NodeInfo { node, value_fingerprint, edges };
+        let node = NodeInfo { node, fingerprint, edges };
 
         let mut local = self.status.local.borrow_mut();
 

compiler/rustc_middle/src/mir/pretty.rs

@@ -1237,6 +1237,10 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                 }
             }
 
+            ShallowInitBox(ref place, ref ty) => {
+                with_no_trimmed_paths!(write!(fmt, "ShallowInitBox({place:?}, {ty})"))
+            }
+
             WrapUnsafeBinder(ref op, ty) => {
                 with_no_trimmed_paths!(write!(fmt, "wrap_binder!({op:?}; {ty})"))
             }

compiler/rustc_middle/src/mir/statement.rs

@@ -747,6 +747,11 @@ impl<'tcx> ConstOperand<'tcx> {
 ///////////////////////////////////////////////////////////////////////////
 // Rvalues
 
+pub enum RvalueInitializationState {
+    Shallow,
+    Deep,
+}
+
 impl<'tcx> Rvalue<'tcx> {
     /// Returns true if rvalue can be safely removed when the result is unused.
     #[inline]
@@ -781,6 +786,7 @@ impl<'tcx> Rvalue<'tcx> {
             | Rvalue::UnaryOp(_, _)
             | Rvalue::Discriminant(_)
             | Rvalue::Aggregate(_, _)
+            | Rvalue::ShallowInitBox(_, _)
             | Rvalue::WrapUnsafeBinder(_, _) => true,
         }
     }
@@ -827,10 +833,21 @@ impl<'tcx> Rvalue<'tcx> {
                 }
                 AggregateKind::RawPtr(ty, mutability) => Ty::new_ptr(tcx, ty, mutability),
             },
+            Rvalue::ShallowInitBox(_, ty) => Ty::new_box(tcx, ty),
             Rvalue::CopyForDeref(ref place) => place.ty(local_decls, tcx).ty,
             Rvalue::WrapUnsafeBinder(_, ty) => ty,
         }
     }
+
+    #[inline]
+    /// Returns `true` if this rvalue is deeply initialized (most rvalues) or
+    /// whether its only shallowly initialized (`Rvalue::Box`).
+    pub fn initialization_state(&self) -> RvalueInitializationState {
+        match *self {
+            Rvalue::ShallowInitBox(_, _) => RvalueInitializationState::Shallow,
+            _ => RvalueInitializationState::Deep,
+        }
+    }
 }
 
 impl BorrowKind {

compiler/rustc_middle/src/mir/syntax.rs

@@ -1458,6 +1458,13 @@ pub enum Rvalue<'tcx> {
     /// coroutine lowering, `Coroutine` aggregate kinds are disallowed too.
     Aggregate(Box<AggregateKind<'tcx>>, IndexVec<FieldIdx, Operand<'tcx>>),
 
+    /// Transmutes a `*mut u8` into shallow-initialized `Box<T>`.
+    ///
+    /// This is different from a normal transmute because dataflow analysis will treat the box as
+    /// initialized but its content as uninitialized. Like other pointer casts, this in general
+    /// affects alias analysis.
+    ShallowInitBox(Operand<'tcx>, Ty<'tcx>),
+
     /// A CopyForDeref is equivalent to a read from a place at the
     /// codegen level, but is treated specially by drop elaboration. When such a read happens, it
     /// is guaranteed (via nature of the mir_opt `Derefer` in rustc_mir_transform/src/deref_separator)

compiler/rustc_middle/src/mir/visit.rs

@@ -810,6 +810,11 @@ macro_rules! make_mir_visitor {
                         }
                     }
 
+                    Rvalue::ShallowInitBox(operand, ty) => {
+                        self.visit_operand(operand, location);
+                        self.visit_ty($(& $mutability)? *ty, TyContext::Location(location));
+                    }
+
                     Rvalue::WrapUnsafeBinder(op, ty) => {
                         self.visit_operand(op, location);
                         self.visit_ty($(& $mutability)? *ty, TyContext::Location(location));

compiler/rustc_middle/src/query/caches.rs

@@ -67,7 +67,7 @@ where
     #[inline]
     fn complete(&self, key: K, value: V, index: DepNodeIndex) {
         // We may be overwriting another value. This is all right, since the dep-graph
-        // will check that the value fingerprint matches.
+        // will check that the fingerprint matches.
         self.cache.insert(key, (value, index));
     }
 

compiler/rustc_middle/src/verify_ich.rs

@@ -25,7 +25,7 @@ pub fn incremental_verify_ich<'tcx, V>(
         tcx.with_stable_hashing_context(|mut hcx| f(&mut hcx, result))
     });
 
-    let old_hash = dep_graph_data.prev_value_fingerprint_of(prev_index);
+    let old_hash = dep_graph_data.prev_fingerprint_of(prev_index);
 
     if new_hash != old_hash {
         incremental_verify_ich_failed(tcx, prev_index, &|| format_value(result));

compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs

@@ -86,6 +86,7 @@ where
 
             Rvalue::Cast(..)
             | Rvalue::Ref(_, BorrowKind::Fake(_), _)
+            | Rvalue::ShallowInitBox(..)
             | Rvalue::Use(..)
             | Rvalue::ThreadLocalRef(..)
             | Rvalue::Repeat(..)

compiler/rustc_mir_dataflow/src/move_paths/builder.rs

@@ -391,7 +391,15 @@ impl<'a, 'tcx, F: Fn(Ty<'tcx>) -> bool> MoveDataBuilder<'a, 'tcx, F> {
             }
             StatementKind::Assign(box (place, rval)) => {
                 self.create_move_path(*place);
+                if let RvalueInitializationState::Shallow = rval.initialization_state() {
+                    // Box starts out uninitialized - need to create a separate
+                    // move-path for the interior so it will be separate from
+                    // the exterior.
+                    self.create_move_path(self.tcx.mk_place_deref(*place));
+                    self.gather_init(place.as_ref(), InitKind::Shallow);
+                } else {
                     self.gather_init(place.as_ref(), InitKind::Deep);
+                }
                 self.gather_rvalue(rval);
             }
             StatementKind::FakeRead(box (_, place)) => {
@@ -427,6 +435,7 @@ impl<'a, 'tcx, F: Fn(Ty<'tcx>) -> bool> MoveDataBuilder<'a, 'tcx, F> {
             Rvalue::Use(ref operand)
             | Rvalue::Repeat(ref operand, _)
             | Rvalue::Cast(_, ref operand, _)
+            | Rvalue::ShallowInitBox(ref operand, _)
             | Rvalue::UnaryOp(_, ref operand)
             | Rvalue::WrapUnsafeBinder(ref operand, _) => self.gather_operand(operand),
             Rvalue::BinaryOp(ref _binop, box (ref lhs, ref rhs)) => {

compiler/rustc_mir_transform/src/dataflow_const_prop.rs

@@ -467,6 +467,7 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
             Rvalue::Discriminant(place) => state.get_discr(place.as_ref(), &self.map),
             Rvalue::Use(operand) => return self.handle_operand(operand, state),
             Rvalue::CopyForDeref(_) => bug!("`CopyForDeref` in runtime MIR"),
+            Rvalue::ShallowInitBox(..) => bug!("`ShallowInitBox` in runtime MIR"),
             Rvalue::Ref(..) | Rvalue::RawPtr(..) => {
                 // We don't track such places.
                 return ValueOrPlace::TOP;

compiler/rustc_mir_transform/src/elaborate_box_derefs.rs

@@ -1,8 +1,12 @@
 //! This pass transforms derefs of Box into a deref of the pointer inside Box.
 //!
 //! Box is not actually a pointer so it is incorrect to dereference it directly.
+//!
+//! `ShallowInitBox` being a device for drop elaboration to understand deferred assignment to box
+//! contents, we do not need this any more on runtime MIR.
 
-use rustc_abi::FieldIdx;
+use rustc_abi::{FieldIdx, VariantIdx};
+use rustc_index::{IndexVec, indexvec};
 use rustc_middle::mir::visit::MutVisitor;
 use rustc_middle::mir::*;
 use rustc_middle::span_bug;
@@ -85,6 +89,68 @@ impl<'a, 'tcx> MutVisitor<'tcx> for ElaborateBoxDerefVisitor<'a, 'tcx> {
 
         self.super_place(place, context, location);
     }
+
+    fn visit_statement(&mut self, stmt: &mut Statement<'tcx>, location: Location) {
+        self.super_statement(stmt, location);
+
+        let tcx = self.tcx;
+        let source_info = stmt.source_info;
+
+        if let StatementKind::Assign(box (_, ref mut rvalue)) = stmt.kind
+            && let Rvalue::ShallowInitBox(ref mut mutptr_to_u8, pointee) = *rvalue
+            && let ty::Adt(box_adt, box_args) = Ty::new_box(tcx, pointee).kind()
+        {
+            let args = tcx.mk_args(&[pointee.into()]);
+            let (unique_ty, nonnull_ty, ptr_ty) =
+                build_ptr_tys(tcx, pointee, self.unique_def, self.nonnull_def);
+            let adt_kind = |def: ty::AdtDef<'tcx>, args| {
+                Box::new(AggregateKind::Adt(def.did(), VariantIdx::ZERO, args, None, None))
+            };
+            let zst = |ty| {
+                Operand::Constant(Box::new(ConstOperand {
+                    span: source_info.span,
+                    user_ty: None,
+                    const_: Const::zero_sized(ty),
+                }))
+            };
+
+            let constptr = self.patch.new_temp(ptr_ty, source_info.span);
+            self.patch.add_assign(
+                location,
+                constptr.into(),
+                Rvalue::Cast(CastKind::Transmute, mutptr_to_u8.clone(), ptr_ty),
+            );
+
+            let nonnull = self.patch.new_temp(nonnull_ty, source_info.span);
+            self.patch.add_assign(
+                location,
+                nonnull.into(),
+                Rvalue::Aggregate(
+                    adt_kind(self.nonnull_def, args),
+                    indexvec![Operand::Move(constptr.into())],
+                ),
+            );
+
+            let unique = self.patch.new_temp(unique_ty, source_info.span);
+            let phantomdata_ty =
+                self.unique_def.non_enum_variant().fields[FieldIdx::ONE].ty(tcx, args);
+            self.patch.add_assign(
+                location,
+                unique.into(),
+                Rvalue::Aggregate(
+                    adt_kind(self.unique_def, args),
+                    indexvec![Operand::Move(nonnull.into()), zst(phantomdata_ty)],
+                ),
+            );
+
+            let global_alloc_ty =
+                box_adt.non_enum_variant().fields[FieldIdx::ONE].ty(tcx, box_args);
+            *rvalue = Rvalue::Aggregate(
+                adt_kind(*box_adt, box_args),
+                indexvec![Operand::Move(unique.into()), zst(global_alloc_ty)],
+            );
+        }
+    }
 }
 
 pub(super) struct ElaborateBoxDerefs;

compiler/rustc_mir_transform/src/gvn.rs

@@ -1069,7 +1069,7 @@ impl<'body, 'a, 'tcx> VnState<'body, 'a, 'tcx> {
 
             // Unsupported values.
             Rvalue::ThreadLocalRef(..) => return None,
-            Rvalue::CopyForDeref(_) => {
+            Rvalue::CopyForDeref(_) | Rvalue::ShallowInitBox(..) => {
                 bug!("forbidden in runtime MIR: {rvalue:?}")
             }
         };

compiler/rustc_mir_transform/src/known_panics_lint.rs

@@ -443,6 +443,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             | Rvalue::CopyForDeref(..)
             | Rvalue::Repeat(..)
             | Rvalue::Cast(..)
+            | Rvalue::ShallowInitBox(..)
             | Rvalue::Discriminant(..)
             | Rvalue::WrapUnsafeBinder(..) => {}
         }
@@ -604,6 +605,8 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
 
             Ref(..) | RawPtr(..) => return None,
 
+            ShallowInitBox(..) => return None,
+
             Cast(ref kind, ref value, to) => match kind {
                 CastKind::IntToInt | CastKind::IntToFloat => {
                     let value = self.eval_operand(value)?;

compiler/rustc_mir_transform/src/lint.rs

@@ -85,6 +85,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Lint<'a, 'tcx> {
                     | Rvalue::Repeat(..)
                     | Rvalue::Aggregate(..)
                     | Rvalue::Cast(..)
+                    | Rvalue::ShallowInitBox(..)
                     | Rvalue::WrapUnsafeBinder(..) => true,
                     Rvalue::ThreadLocalRef(..)
                     | Rvalue::UnaryOp(..)

compiler/rustc_mir_transform/src/pass_manager.rs

@@ -1,6 +1,5 @@
 use std::cell::RefCell;
 use std::collections::hash_map::Entry;
-use std::sync::atomic::Ordering;
 
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
 use rustc_middle::mir::{Body, MirDumper, MirPhase, RuntimePhase};
@@ -286,19 +285,6 @@ fn run_passes_inner<'tcx>(
                 continue;
             };
 
-            if is_optimization_stage(body, phase_change, optimizations)
-                && let Some(limit) = &tcx.sess.opts.unstable_opts.mir_opt_bisect_limit
-            {
-                if limited_by_opt_bisect(
-                    tcx,
-                    tcx.def_path_debug_str(body.source.def_id()),
-                    *limit,
-                    *pass,
-                ) {
-                    continue;
-                }
-            }
-
             let dumper = if pass.is_mir_dump_enabled()
                 && let Some(dumper) = MirDumper::new(tcx, pass_name, body)
             {
@@ -370,46 +356,3 @@ pub(super) fn dump_mir_for_phase_change<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tc
         dumper.set_show_pass_num().set_disambiguator(&"after").dump_mir(body)
     }
 }
-
-fn is_optimization_stage(
-    body: &Body<'_>,
-    phase_change: Option<MirPhase>,
-    optimizations: Optimizations,
-) -> bool {
-    optimizations == Optimizations::Allowed
-        && body.phase == MirPhase::Runtime(RuntimePhase::PostCleanup)
-        && phase_change == Some(MirPhase::Runtime(RuntimePhase::Optimized))
-}
-
-fn limited_by_opt_bisect<'tcx, P>(
-    tcx: TyCtxt<'tcx>,
-    def_path: String,
-    limit: usize,
-    pass: &P,
-) -> bool
-where
-    P: MirPass<'tcx> + ?Sized,
-{
-    let current_opt_bisect_count =
-        tcx.sess.mir_opt_bisect_eval_count.fetch_add(1, Ordering::Relaxed);
-
-    let can_run = current_opt_bisect_count < limit;
-
-    if can_run {
-        eprintln!(
-            "BISECT: running pass ({}) {} on {}",
-            current_opt_bisect_count + 1,
-            pass.name(),
-            def_path
-        );
-    } else {
-        eprintln!(
-            "BISECT: NOT running pass ({}) {} on {}",
-            current_opt_bisect_count + 1,
-            pass.name(),
-            def_path
-        );
-    }
-
-    !can_run
-}

compiler/rustc_mir_transform/src/promote_consts.rs

@@ -449,6 +449,8 @@ impl<'tcx> Validator<'_, 'tcx> {
                 self.validate_operand(operand)?;
             }
 
+            Rvalue::ShallowInitBox(_, _) => return Err(Unpromotable),
+
             Rvalue::UnaryOp(op, operand) => {
                 match op {
                     // These operations can never fail.

compiler/rustc_mir_transform/src/single_use_consts.rs

@@ -85,7 +85,7 @@ impl<'tcx> crate::MirPass<'tcx> for SingleUseConsts {
     }
 
     fn is_required(&self) -> bool {
-        false
+        true
     }
 }
 

compiler/rustc_mir_transform/src/validate.rs

@@ -1259,6 +1259,14 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     }
                 }
             }
+            Rvalue::ShallowInitBox(operand, _) => {
+                if self.body.phase >= MirPhase::Runtime(RuntimePhase::Initial) {
+                    self.fail(location, format!("ShallowInitBox after ElaborateBoxDerefs"))
+                }
+
+                let a = operand.ty(&self.body.local_decls, self.tcx);
+                check_kinds!(a, "Cannot shallow init type {:?}", ty::RawPtr(..));
+            }
             Rvalue::Cast(kind, operand, target_type) => {
                 let op_ty = operand.ty(self.body, self.tcx);
                 match kind {

compiler/rustc_public/src/mir/body.rs

@@ -567,6 +567,13 @@ pub enum Rvalue {
     /// [#74836]: https://github.com/rust-lang/rust/issues/74836
     Repeat(Operand, TyConst),
 
+    /// Transmutes a `*mut u8` into shallow-initialized `Box<T>`.
+    ///
+    /// This is different from a normal transmute because dataflow analysis will treat the box as
+    /// initialized but its content as uninitialized. Like other pointer casts, this in general
+    /// affects alias analysis.
+    ShallowInitBox(Operand, Ty),
+
     /// Creates a pointer/reference to the given thread local.
     ///
     /// The yielded type is a `*mut T` if the static is mutable, otherwise if the static is extern a
@@ -644,6 +651,7 @@ impl Rvalue {
                 }
                 AggregateKind::RawPtr(ty, mutability) => Ok(Ty::new_ptr(ty, mutability)),
             },
+            Rvalue::ShallowInitBox(_, ty) => Ok(Ty::new_box(*ty)),
             Rvalue::CopyForDeref(place) => place.ty(locals),
         }
     }

compiler/rustc_public/src/mir/pretty.rs

@@ -383,6 +383,7 @@ fn pretty_rvalue<W: Write>(writer: &mut W, rval: &Rvalue) -> io::Result<()> {
         Rvalue::Repeat(op, cnst) => {
             write!(writer, "[{}; {}]", pretty_operand(op), pretty_ty_const(cnst))
         }
+        Rvalue::ShallowInitBox(_, _) => Ok(()),
         Rvalue::ThreadLocalRef(item) => {
             write!(writer, "thread_local_ref{item:?}")
         }

compiler/rustc_public/src/mir/visit.rs

@@ -277,6 +277,10 @@ macro_rules! make_mir_visitor {
                         self.visit_operand(op, location);
                         self.visit_ty_const(constant, location);
                     }
+                    Rvalue::ShallowInitBox(op, ty) => {
+                        self.visit_ty(ty, location);
+                        self.visit_operand(op, location)
+                    }
                     Rvalue::ThreadLocalRef(_) => {}
                     Rvalue::UnaryOp(_, op) | Rvalue::Use(op) => {
                         self.visit_operand(op, location);

compiler/rustc_public/src/unstable/convert/stable/mir.rs

@@ -240,6 +240,9 @@ impl<'tcx> Stable<'tcx> for mir::Rvalue<'tcx> {
                 let operands = operands.iter().map(|op| op.stable(tables, cx)).collect();
                 crate::mir::Rvalue::Aggregate(agg_kind.stable(tables, cx), operands)
             }
+            ShallowInitBox(op, ty) => {
+                crate::mir::Rvalue::ShallowInitBox(op.stable(tables, cx), ty.stable(tables, cx))
+            }
             CopyForDeref(place) => crate::mir::Rvalue::CopyForDeref(place.stable(tables, cx)),
             WrapUnsafeBinder(..) => todo!("FIXME(unsafe_binders):"),
         }

compiler/rustc_query_impl/src/dep_kind_vtables.rs

@@ -1,5 +1,5 @@
 use rustc_middle::bug;
-use rustc_middle::dep_graph::{DepKindVTable, DepNodeKey, KeyFingerprintStyle};
+use rustc_middle::dep_graph::{DepKindVTable, DepNodeKey, FingerprintStyle};
 use rustc_middle::query::QueryCache;
 
 use crate::plumbing::{force_from_dep_node_inner, try_load_from_on_disk_cache_inner};
@@ -15,7 +15,7 @@ mod non_query {
         DepKindVTable {
             is_anon: false,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Unit,
+            fingerprint_style: FingerprintStyle::Unit,
             force_from_dep_node: Some(|_, dep_node, _| {
                 bug!("force_from_dep_node: encountered {dep_node:?}")
             }),
@@ -29,7 +29,7 @@ mod non_query {
         DepKindVTable {
             is_anon: false,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Unit,
+            fingerprint_style: FingerprintStyle::Unit,
             force_from_dep_node: Some(|_, dep_node, _| {
                 bug!("force_from_dep_node: encountered {dep_node:?}")
             }),
@@ -42,7 +42,7 @@ mod non_query {
         DepKindVTable {
             is_anon: false,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Unit,
+            fingerprint_style: FingerprintStyle::Unit,
             force_from_dep_node: Some(|tcx, _, prev_index| {
                 tcx.dep_graph.force_diagnostic_node(tcx, prev_index);
                 true
@@ -56,7 +56,7 @@ mod non_query {
         DepKindVTable {
             is_anon: true,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Opaque,
+            fingerprint_style: FingerprintStyle::Opaque,
             force_from_dep_node: Some(|_, _, _| bug!("cannot force an anon node")),
             try_load_from_on_disk_cache: None,
             name: &"AnonZeroDeps",
@@ -67,7 +67,7 @@ mod non_query {
         DepKindVTable {
             is_anon: true,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Unit,
+            fingerprint_style: FingerprintStyle::Unit,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
             name: &"TraitSelect",
@@ -78,7 +78,7 @@ mod non_query {
         DepKindVTable {
             is_anon: false,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Opaque,
+            fingerprint_style: FingerprintStyle::Opaque,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
             name: &"CompileCodegenUnit",
@@ -89,7 +89,7 @@ mod non_query {
         DepKindVTable {
             is_anon: false,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Opaque,
+            fingerprint_style: FingerprintStyle::Opaque,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
             name: &"CompileMonoItem",
@@ -100,7 +100,7 @@ mod non_query {
         DepKindVTable {
             is_anon: false,
             is_eval_always: false,
-            key_fingerprint_style: KeyFingerprintStyle::Unit,
+            fingerprint_style: FingerprintStyle::Unit,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
             name: &"Metadata",
@@ -118,17 +118,17 @@ where
     Cache: QueryCache + 'tcx,
 {
     let is_anon = FLAGS.is_anon;
-    let key_fingerprint_style = if is_anon {
-        KeyFingerprintStyle::Opaque
+    let fingerprint_style = if is_anon {
+        FingerprintStyle::Opaque
     } else {
-        <Cache::Key as DepNodeKey<'tcx>>::key_fingerprint_style()
+        <Cache::Key as DepNodeKey<'tcx>>::fingerprint_style()
     };
 
-    if is_anon || !key_fingerprint_style.reconstructible() {
+    if is_anon || !fingerprint_style.reconstructible() {
         return DepKindVTable {
             is_anon,
             is_eval_always,
-            key_fingerprint_style,
+            fingerprint_style,
             force_from_dep_node: None,
             try_load_from_on_disk_cache: None,
             name: Q::NAME,
@@ -138,7 +138,7 @@ where
     DepKindVTable {
         is_anon,
         is_eval_always,
-        key_fingerprint_style,
+        fingerprint_style,
         force_from_dep_node: Some(|tcx, dep_node, _| {
             force_from_dep_node_inner(Q::query_dispatcher(tcx), tcx, dep_node)
         }),

compiler/rustc_query_impl/src/execution.rs

@@ -509,7 +509,7 @@ fn try_load_from_disk_and_cache_in_memory<'tcx, C: QueryCache, const FLAGS: Quer
             dep_graph_data.mark_debug_loaded_from_disk(*dep_node)
         }
 
-        let prev_fingerprint = dep_graph_data.prev_value_fingerprint_of(prev_dep_node_index);
+        let prev_fingerprint = dep_graph_data.prev_fingerprint_of(prev_dep_node_index);
         // If `-Zincremental-verify-ich` is specified, re-hash results from
         // the cache and make sure that they have the expected fingerprint.
         //
@@ -538,7 +538,7 @@ fn try_load_from_disk_and_cache_in_memory<'tcx, C: QueryCache, const FLAGS: Quer
     // can be forced from `DepNode`.
     debug_assert!(
         !query.will_cache_on_disk_for_key(tcx, key)
-            || !tcx.key_fingerprint_style(dep_node.kind).reconstructible(),
+            || !tcx.fingerprint_style(dep_node.kind).reconstructible(),
         "missing on-disk cache entry for {dep_node:?}"
     );
 

compiler/rustc_query_impl/src/plumbing.rs

@@ -396,11 +396,8 @@ pub(crate) fn try_load_from_on_disk_cache_inner<'tcx, C: QueryCache, const FLAGS
 ) {
     debug_assert!(tcx.dep_graph.is_green(&dep_node));
 
-    let key = C::Key::try_recover_key(tcx, &dep_node).unwrap_or_else(|| {
-        panic!(
-            "Failed to recover key for {dep_node:?} with key fingerprint {}",
-            dep_node.key_fingerprint
-        )
+    let key = C::Key::recover(tcx, &dep_node).unwrap_or_else(|| {
+        panic!("Failed to recover key for {:?} with hash {}", dep_node, dep_node.hash)
     });
     if query.will_cache_on_disk_for_key(tcx, &key) {
         // Call `tcx.$query(key)` for its side-effect of loading the disk-cached
@@ -465,7 +462,7 @@ pub(crate) fn force_from_dep_node_inner<'tcx, C: QueryCache, const FLAGS: QueryF
         "calling force_from_dep_node() on dep_kinds::codegen_unit"
     );
 
-    if let Some(key) = C::Key::try_recover_key(tcx, &dep_node) {
+    if let Some(key) = C::Key::recover(tcx, &dep_node) {
         force_query(query, tcx, key, dep_node);
         true
     } else {

compiler/rustc_resolve/src/imports.rs

@@ -371,8 +371,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         // - A glob decl is overwritten by its clone after setting ambiguity in it.
         //   FIXME: avoid this by removing `warn_ambiguity`, or by triggering glob re-fetch
         //   with the same decl in some way.
-        // - A glob decl is overwritten by a glob decl with larger visibility.
-        //   FIXME: avoid this by updating this visibility in place.
         // - A glob decl is overwritten by a glob decl re-fetching an
         //   overwritten decl from other module (the recursive case).
         // Here we are detecting all such re-fetches and overwrite old decls
@@ -386,8 +384,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             // FIXME: reenable the asserts when `warn_ambiguity` is removed (#149195).
             // assert_ne!(old_deep_decl, deep_decl);
             // assert!(old_deep_decl.is_glob_import());
-            // FIXME: reenable the assert when visibility is updated in place.
-            // assert!(!deep_decl.is_glob_import());
+            assert!(!deep_decl.is_glob_import());
             if old_glob_decl.ambiguity.get().is_some() && glob_decl.ambiguity.get().is_none() {
                 // Do not lose glob ambiguities when re-fetching the glob.
                 glob_decl.ambiguity.set_unchecked(old_glob_decl.ambiguity.get());

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -4060,23 +4060,17 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                             "instead, you are more likely to want"
                         };
                         let mut owned_sugg = lt.kind == MissingLifetimeKind::Ampersand;
-                        let mut sugg_is_str_to_string = false;
                         let mut sugg = vec![(lt.span, String::new())];
                         if let Some((kind, _span)) = self.diag_metadata.current_function
                             && let FnKind::Fn(_, _, ast::Fn { sig, .. }) = kind
+                            && let ast::FnRetTy::Ty(ty) = &sig.decl.output
                         {
                             let mut lt_finder =
                                 LifetimeFinder { lifetime: lt.span, found: None, seen: vec![] };
-                            for param in &sig.decl.inputs {
-                                lt_finder.visit_ty(&param.ty);
-                            }
-                            if let ast::FnRetTy::Ty(ret_ty) = &sig.decl.output {
-                                lt_finder.visit_ty(ret_ty);
-                                let mut ret_lt_finder =
-                                    LifetimeFinder { lifetime: lt.span, found: None, seen: vec![] };
-                                ret_lt_finder.visit_ty(ret_ty);
+                            lt_finder.visit_ty(&ty);
+
                             if let [Ty { span, kind: TyKind::Ref(_, mut_ty), .. }] =
-                                    &ret_lt_finder.seen[..]
+                                &lt_finder.seen[..]
                             {
                                 // We might have a situation like
                                 // fn g(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'_ ()>
@@ -4086,7 +4080,6 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                                 sugg = vec![(span.with_hi(mut_ty.ty.span.lo()), String::new())];
                                 owned_sugg = true;
                             }
-                            }
                             if let Some(ty) = lt_finder.found {
                                 if let TyKind::Path(None, path) = &ty.kind {
                                     // Check if the path being borrowed is likely to be owned.
@@ -4105,7 +4098,6 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                                                         lt.span.with_hi(ty.span.hi()),
                                                         "String".to_string(),
                                                     )];
-                                                    sugg_is_str_to_string = true;
                                                 }
                                                 Some(Res::PrimTy(..)) => {}
                                                 Some(Res::Def(
@@ -4132,7 +4124,6 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                                                         lt.span.with_hi(ty.span.hi()),
                                                         "String".to_string(),
                                                     )];
-                                                    sugg_is_str_to_string = true;
                                                 }
                                                 Res::PrimTy(..) => {}
                                                 Res::Def(
@@ -4167,12 +4158,6 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                             }
                         }
                         if owned_sugg {
-                            if let Some(span) =
-                                self.find_ref_prefix_span_for_owned_suggestion(lt.span)
-                                && !sugg_is_str_to_string
-                            {
-                                sugg = vec![(span, String::new())];
-                            }
                             err.multipart_suggestion_verbose(
                                 format!("{pre} to return an owned value"),
                                 sugg,
@@ -4199,23 +4184,6 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             }
         }
     }
-
-    fn find_ref_prefix_span_for_owned_suggestion(&self, lifetime: Span) -> Option<Span> {
-        let mut finder = RefPrefixSpanFinder { lifetime, span: None };
-        if let Some(item) = self.diag_metadata.current_item {
-            finder.visit_item(item);
-        } else if let Some((kind, _span)) = self.diag_metadata.current_function
-            && let FnKind::Fn(_, _, ast::Fn { sig, .. }) = kind
-        {
-            for param in &sig.decl.inputs {
-                finder.visit_ty(&param.ty);
-            }
-            if let ast::FnRetTy::Ty(ret_ty) = &sig.decl.output {
-                finder.visit_ty(ret_ty);
-            }
-        }
-        finder.span
-    }
 }
 
 fn mk_where_bound_predicate(
@@ -4317,26 +4285,6 @@ impl<'ast> Visitor<'ast> for LifetimeFinder<'ast> {
     }
 }
 
-struct RefPrefixSpanFinder {
-    lifetime: Span,
-    span: Option<Span>,
-}
-
-impl<'ast> Visitor<'ast> for RefPrefixSpanFinder {
-    fn visit_ty(&mut self, t: &'ast Ty) {
-        if self.span.is_some() {
-            return;
-        }
-        if let TyKind::Ref(_, mut_ty) | TyKind::PinnedRef(_, mut_ty) = &t.kind
-            && t.span.lo() == self.lifetime.lo()
-        {
-            self.span = Some(t.span.with_hi(mut_ty.ty.span.lo()));
-            return;
-        }
-        walk_ty(self, t);
-    }
-}
-
 /// Shadowing involving a label is only a warning for historical reasons.
 //FIXME: make this a proper lint.
 pub(super) fn signal_label_shadowing(sess: &Session, orig: Span, shadower: Ident) {

compiler/rustc_session/src/options.rs

@@ -2481,9 +2481,6 @@ options! {
     mir_include_spans: MirIncludeSpans = (MirIncludeSpans::default(), parse_mir_include_spans, [UNTRACKED],
         "include extra comments in mir pretty printing, like line numbers and statement indices, \
          details about types, etc. (boolean for all passes, 'nll' to enable in NLL MIR only, default: 'nll')"),
-    mir_opt_bisect_limit: Option<usize> = (None, parse_opt_number, [TRACKED],
-        "limit the number of MIR optimization pass executions (global across all bodies). \
-        Pass executions after this limit are skipped and reported. (default: no limit)"),
     #[rustc_lint_opt_deny_field_access("use `Session::mir_opt_level` instead of this field")]
     mir_opt_level: Option<usize> = (None, parse_opt_number, [TRACKED],
         "MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)"),

compiler/rustc_session/src/session.rs

@@ -2,7 +2,7 @@ use std::any::Any;
 use std::path::PathBuf;
 use std::str::FromStr;
 use std::sync::Arc;
-use std::sync::atomic::{AtomicBool, AtomicUsize};
+use std::sync::atomic::AtomicBool;
 use std::{env, io};
 
 use rand::{RngCore, rng};
@@ -161,12 +161,6 @@ pub struct Session {
 
     /// Does the codegen backend support ThinLTO?
     pub thin_lto_supported: bool,
-
-    /// Global per-session counter for MIR optimization pass applications.
-    ///
-    /// Used by `-Zmir-opt-bisect-limit` to assign an index to each
-    /// optimization-pass execution candidate during this compilation.
-    pub mir_opt_bisect_eval_count: AtomicUsize,
 }
 
 #[derive(Clone, Copy)]
@@ -1107,7 +1101,6 @@ pub fn build_session(
         invocation_temp,
         replaced_intrinsics: FxHashSet::default(), // filled by `run_compiler`
         thin_lto_supported: true,                  // filled by `run_compiler`
-        mir_opt_bisect_eval_count: AtomicUsize::new(0),
     };
 
     validate_commandline_args_with_session_available(&sess);

compiler/rustc_span/src/symbol.rs

@@ -327,6 +327,7 @@ symbols! {
         Pointer,
         Poll,
         ProcMacro,
+        ProceduralMasqueradeDummyType,
         Range,
         RangeBounds,
         RangeCopy,

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

@@ -300,9 +300,6 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 let rebased_args = alias.args.rebase_onto(tcx, trait_def_id, impl_substs);
 
                 let impl_item_def_id = leaf_def.item.def_id;
-                if !tcx.check_args_compatible(impl_item_def_id, rebased_args) {
-                    return false;
-                }
                 let impl_assoc_ty = tcx.type_of(impl_item_def_id).instantiate(tcx, rebased_args);
 
                 self.infcx.can_eq(param_env, impl_assoc_ty, concrete)

compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/trait_impl_difference.rs

@@ -11,7 +11,7 @@ use rustc_middle::traits::ObligationCauseCode;
 use rustc_middle::ty::error::ExpectedFound;
 use rustc_middle::ty::print::RegionHighlightMode;
 use rustc_middle::ty::{self, TyCtxt, TypeVisitable};
-use rustc_span::{Ident, Span};
+use rustc_span::Span;
 use tracing::debug;
 
 use crate::error_reporting::infer::nice_region_error::NiceRegionError;
@@ -99,8 +99,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
 
         // Get the span of all the used type parameters in the method.
         let assoc_item = self.tcx().associated_item(trait_item_def_id);
-        let mut visitor =
-            TypeParamSpanVisitor { tcx: self.tcx(), types: vec![], elided_lifetime_paths: vec![] };
+        let mut visitor = TypeParamSpanVisitor { tcx: self.tcx(), types: vec![] };
         match assoc_item.kind {
             ty::AssocKind::Fn { .. } => {
                 if let Some(hir_id) =
@@ -123,49 +122,13 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             found,
         };
 
-        let mut diag = self.tcx().dcx().create_err(diag);
-        // A limit not to make diag verbose.
-        const ELIDED_LIFETIME_NOTE_LIMIT: usize = 5;
-        let elided_lifetime_paths = visitor.elided_lifetime_paths;
-        let total_elided_lifetime_paths = elided_lifetime_paths.len();
-        let shown_elided_lifetime_paths = if tcx.sess.opts.verbose {
-            total_elided_lifetime_paths
-        } else {
-            ELIDED_LIFETIME_NOTE_LIMIT
-        };
-
-        for elided in elided_lifetime_paths.into_iter().take(shown_elided_lifetime_paths) {
-            diag.span_note(
-                elided.span,
-                format!("`{}` here is elided as `{}`", elided.ident, elided.shorthand),
-            );
+        self.tcx().dcx().emit_err(diag)
     }
-        if total_elided_lifetime_paths > shown_elided_lifetime_paths {
-            diag.note(format!(
-                "and {} more elided lifetime{} in type paths",
-                total_elided_lifetime_paths - shown_elided_lifetime_paths,
-                if total_elided_lifetime_paths - shown_elided_lifetime_paths == 1 {
-                    ""
-                } else {
-                    "s"
-                },
-            ));
-        }
-        diag.emit()
-    }
-}
-
-#[derive(Clone)]
-struct ElidedLifetimeInPath {
-    span: Span,
-    ident: Ident,
-    shorthand: String,
 }
 
 struct TypeParamSpanVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
     types: Vec<Span>,
-    elided_lifetime_paths: Vec<ElidedLifetimeInPath>,
 }
 
 impl<'tcx> Visitor<'tcx> for TypeParamSpanVisitor<'tcx> {
@@ -175,83 +138,6 @@ impl<'tcx> Visitor<'tcx> for TypeParamSpanVisitor<'tcx> {
         self.tcx
     }
 
-    fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, _span: Span) {
-        fn record_elided_lifetimes(
-            tcx: TyCtxt<'_>,
-            elided_lifetime_paths: &mut Vec<ElidedLifetimeInPath>,
-            segment: &hir::PathSegment<'_>,
-        ) {
-            let Some(args) = segment.args else { return };
-            if args.parenthesized != hir::GenericArgsParentheses::No {
-                // Our diagnostic rendering below uses `<...>` syntax; skip cases like `Fn(..) -> ..`.
-                return;
-            }
-            let elided_count = args
-                .args
-                .iter()
-                .filter(|arg| {
-                    let hir::GenericArg::Lifetime(l) = arg else { return false };
-                    l.syntax == hir::LifetimeSyntax::Implicit
-                        && matches!(l.source, hir::LifetimeSource::Path { .. })
-                })
-                .count();
-            if elided_count == 0
-                || elided_lifetime_paths.iter().any(|p| p.span == segment.ident.span)
-            {
-                return;
-            }
-
-            let sm = tcx.sess.source_map();
-            let mut parts = args
-                .args
-                .iter()
-                .map(|arg| match arg {
-                    hir::GenericArg::Lifetime(l) => {
-                        if l.syntax == hir::LifetimeSyntax::Implicit
-                            && matches!(l.source, hir::LifetimeSource::Path { .. })
-                        {
-                            "'_".to_string()
-                        } else {
-                            sm.span_to_snippet(l.ident.span)
-                                .unwrap_or_else(|_| format!("'{}", l.ident.name))
-                        }
-                    }
-                    hir::GenericArg::Type(ty) => {
-                        sm.span_to_snippet(ty.span).unwrap_or_else(|_| "..".to_string())
-                    }
-                    hir::GenericArg::Const(ct) => {
-                        sm.span_to_snippet(ct.span).unwrap_or_else(|_| "..".to_string())
-                    }
-                    hir::GenericArg::Infer(_) => "_".to_string(),
-                })
-                .collect::<Vec<_>>();
-            parts.extend(args.constraints.iter().map(|constraint| {
-                sm.span_to_snippet(constraint.span)
-                    .unwrap_or_else(|_| format!("{} = ..", constraint.ident))
-            }));
-            let shorthand = format!("{}<{}>", segment.ident, parts.join(", "));
-
-            elided_lifetime_paths.push(ElidedLifetimeInPath {
-                span: segment.ident.span,
-                ident: segment.ident,
-                shorthand,
-            });
-        }
-
-        match qpath {
-            hir::QPath::Resolved(_, path) => {
-                for segment in path.segments {
-                    record_elided_lifetimes(self.tcx, &mut self.elided_lifetime_paths, segment);
-                }
-            }
-            hir::QPath::TypeRelative(_, segment) => {
-                record_elided_lifetimes(self.tcx, &mut self.elided_lifetime_paths, segment);
-            }
-        }
-
-        hir::intravisit::walk_qpath(self, qpath, id);
-    }
-
     fn visit_ty(&mut self, arg: &'tcx hir::Ty<'tcx, AmbigArg>) {
         match arg.kind {
             hir::TyKind::Ref(_, ref mut_ty) => {

library/alloc/src/lib.rs

@@ -182,6 +182,7 @@
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(optimize_attribute)]
+#![feature(rustc_allow_const_fn_unstable)]
 #![feature(rustc_attrs)]
 #![feature(slice_internals)]
 #![feature(staged_api)]

library/core/src/lib.rs

@@ -159,6 +159,7 @@
 #![feature(pattern_types)]
 #![feature(prelude_import)]
 #![feature(repr_simd)]
+#![feature(rustc_allow_const_fn_unstable)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 #![feature(simd_ffi)]

library/core/src/num/int_macros.rs

@@ -2481,8 +2481,7 @@ macro_rules! int_impl {
         ///
         /// Returns a tuple of the addition along with a boolean indicating
         /// whether an arithmetic overflow would occur. If an overflow would have
-        /// occurred then the wrapped value is returned (negative if overflowed
-        /// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
+        /// occurred then the wrapped value is returned.
         ///
         /// # Examples
         ///
@@ -2517,9 +2516,6 @@ macro_rules! int_impl {
         /// The output boolean returned by this method is *not* a carry flag,
         /// and should *not* be added to a more significant word.
         ///
-        /// If overflow occurred, the wrapped value is returned (negative if overflowed
-        /// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
-        ///
         /// If the input carry is false, this method is equivalent to
         /// [`overflowing_add`](Self::overflowing_add).
         ///
@@ -2587,8 +2583,7 @@ macro_rules! int_impl {
         /// Calculates `self` - `rhs`.
         ///
         /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow
-        /// would occur. If an overflow would have occurred then the wrapped value is returned
-        /// (negative if overflowed above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
+        /// would occur. If an overflow would have occurred then the wrapped value is returned.
         ///
         /// # Examples
         ///
@@ -2624,9 +2619,6 @@ macro_rules! int_impl {
         /// The output boolean returned by this method is *not* a borrow flag,
         /// and should *not* be subtracted from a more significant word.
         ///
-        /// If overflow occurred, the wrapped value is returned (negative if overflowed
-        /// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
-        ///
         /// If the input borrow is false, this method is equivalent to
         /// [`overflowing_sub`](Self::overflowing_sub).
         ///

library/core/src/num/uint_macros.rs

@@ -487,8 +487,8 @@ macro_rules! uint_impl {
 
         /// Performs a carry-less multiplication, returning the lower bits.
         ///
-        /// This operation is similar to long multiplication in base 2, except that exclusive or is
-        /// used instead of addition. The implementation is equivalent to:
+        /// This operation is similar to long multiplication, except that exclusive or is used
+        /// instead of addition. The implementation is equivalent to:
         ///
         /// ```no_run
         #[doc = concat!("pub fn carryless_mul(lhs: ", stringify!($SelfT), ", rhs: ", stringify!($SelfT), ") -> ", stringify!($SelfT), "{")]

library/std/src/sys/args/unix.rs

@@ -164,7 +164,7 @@ mod imp {
 // of this used `[[NSProcessInfo processInfo] arguments]`.
 #[cfg(target_vendor = "apple")]
 mod imp {
-    use crate::ffi::c_char;
+    use crate::ffi::{c_char, c_int};
 
     pub unsafe fn init(_argc: isize, _argv: *const *const u8) {
         // No need to initialize anything in here, `libdyld.dylib` has already
@@ -172,6 +172,12 @@ mod imp {
     }
 
     pub fn argc_argv() -> (isize, *const *const c_char) {
+        unsafe extern "C" {
+            // These functions are in crt_externs.h.
+            fn _NSGetArgc() -> *mut c_int;
+            fn _NSGetArgv() -> *mut *mut *mut c_char;
+        }
+
         // SAFETY: The returned pointer points to a static initialized early
         // in the program lifetime by `libdyld.dylib`, and as such is always
         // valid.
@@ -181,9 +187,9 @@ mod imp {
         // doesn't exist a lock that we can take. Instead, it is generally
         // expected that it's only modified in `main` / before other code
         // runs, so reading this here should be fine.
-        let argc = unsafe { libc::_NSGetArgc().read() };
+        let argc = unsafe { _NSGetArgc().read() };
         // SAFETY: Same as above.
-        let argv = unsafe { libc::_NSGetArgv().read() };
+        let argv = unsafe { _NSGetArgv().read() };
 
         // Cast from `*mut *mut c_char` to `*const *const c_char`
         (argc as isize, argv.cast())

src/doc/rustc/src/lints/levels.md

@@ -393,7 +393,7 @@ Here’s how these different lint controls interact:
     warning: 1 warning emitted
    ```
 
-3. [CLI level flags](#via-compiler-flag) override the default level of a lint. They essentially behave like crate-level attributes. Attributes within the source code take precedence over CLI flags, except for `-F`/`--forbid`, which cannot be overridden.
+3. [CLI level flags](#via-compiler-flag) take precedence over attributes.
 
    The order of the flags matter; flags on the right take precedence over earlier flags.
 

src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs

@@ -194,6 +194,7 @@ fn check_rvalue<'tcx>(
                 ))
             }
         },
+        Rvalue::ShallowInitBox(_, _) => Ok(()),
         Rvalue::UnaryOp(_, operand) => {
             let ty = operand.ty(body, cx.tcx);
             if ty.is_integral() || ty.is_bool() {

src/tools/miri/src/concurrency/thread.rs

@@ -343,8 +343,8 @@ impl VisitProvenance for Thread<'_> {
 
 impl VisitProvenance for Frame<'_, Provenance, FrameExtra<'_>> {
     fn visit_provenance(&self, visit: &mut VisitWith<'_>) {
-        let return_place = self.return_place();
         let Frame {
+            return_place,
             locals,
             extra,
             // There are some private fields we cannot access; they contain no tags.

src/tools/miri/src/diagnostics.rs

@@ -493,7 +493,7 @@ pub fn report_result<'tcx>(
     for (i, frame) in ecx.active_thread_stack().iter().enumerate() {
         trace!("-------------------");
         trace!("Frame {}", i);
-        trace!("    return: {:?}", frame.return_place());
+        trace!("    return: {:?}", frame.return_place);
         for (i, local) in frame.locals.iter().enumerate() {
             trace!("    local {}: {:?}", i, local);
         }

src/tools/miri/src/machine.rs

@@ -1235,7 +1235,7 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
             // to run extra MIR), and Ok(Some(body)) if we found MIR to run for the
             // foreign function
             // Any needed call to `goto_block` will be performed by `emulate_foreign_item`.
-            let args = MiriInterpCx::copy_fn_args(args); // FIXME: Should `InPlace` arguments be reset to uninit?
+            let args = ecx.copy_fn_args(args); // FIXME: Should `InPlace` arguments be reset to uninit?
             let link_name = Symbol::intern(ecx.tcx.symbol_name(instance).name);
             return ecx.emulate_foreign_item(link_name, abi, &args, dest, ret, unwind);
         }
@@ -1262,7 +1262,7 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
         ret: Option<mir::BasicBlock>,
         unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx> {
-        let args = MiriInterpCx::copy_fn_args(args); // FIXME: Should `InPlace` arguments be reset to uninit?
+        let args = ecx.copy_fn_args(args); // FIXME: Should `InPlace` arguments be reset to uninit?
         ecx.emulate_dyn_sym(fn_val, abi, &args, dest, ret, unwind)
     }
 

src/tools/miri/tests/fail/tail_calls/dangling-local-var.stderr

@@ -14,8 +14,8 @@ LL |     let local = 0;
 help: ALLOC was deallocated here:
   --> tests/fail/tail_calls/dangling-local-var.rs:LL:CC
    |
-LL |     let _val = unsafe { *x };
-   |         ^^^^
+LL |     f(std::ptr::null());
+   |     ^^^^^^^^^^^^^^^^^^^
    = note: stack backtrace:
            0: g
                at tests/fail/tail_calls/dangling-local-var.rs:LL:CC

src/tools/miri/tests/fail/validity/recursive-validity-box-bool.rs

@@ -1,8 +0,0 @@
-//@compile-flags: -Zmiri-recursive-validation
-
-fn main() {
-    let x = 3u8;
-    let xref = &x;
-    let xref_wrong_type: Box<bool> = unsafe { std::mem::transmute(xref) }; //~ERROR: encountered 0x03, but expected a boolean
-    let _val = *xref_wrong_type;
-}

src/tools/miri/tests/fail/validity/recursive-validity-box-bool.stderr

@@ -1,13 +0,0 @@
-error: Undefined Behavior: constructing invalid value at .<deref>: encountered 0x03, but expected a boolean
-  --> tests/fail/validity/recursive-validity-box-bool.rs:LL:CC
-   |
-LL |     let xref_wrong_type: Box<bool> = unsafe { std::mem::transmute(xref) };
-   |                                               ^^^^^^^^^^^^^^^^^^^^^^^^^ Undefined Behavior occurred here
-   |
-   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
-   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
-
-note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
-
-error: aborting due to 1 previous error
-

src/tools/miri/tests/pass/tail_call.rs

@@ -4,7 +4,6 @@
 fn main() {
     assert_eq!(factorial(10), 3_628_800);
     assert_eq!(mutually_recursive_identity(1000), 1000);
-    non_scalar();
 }
 
 fn factorial(n: u32) -> u32 {
@@ -38,14 +37,3 @@ fn mutually_recursive_identity(x: u32) -> u32 {
 
     switch(x, 0)
 }
-
-fn non_scalar() {
-    fn f(x: [usize; 2], i: u32) {
-        if i == 0 {
-            return;
-        }
-        become f(x, i - 1);
-    }
-
-    f([5, 5], 2);
-}

tests/codegen-llvm/intrinsics/likely_assert.rs

@@ -1,5 +1,5 @@
 //@ compile-flags: -Copt-level=3
-#![feature(panic_internals, const_eval_select, rustc_attrs, core_intrinsics)]
+#![feature(panic_internals, const_eval_select, rustc_allow_const_fn_unstable, core_intrinsics)]
 #![crate_type = "lib"]
 
 // check that assert! and const_assert! emit branch weights

tests/mir-opt/optimize_none.rs

@@ -15,14 +15,13 @@ pub fn add_noopt() -> i32 {
 #[optimize(none)]
 pub fn const_branch() -> i32 {
     // CHECK-LABEL: fn const_branch(
-    // CHECK: [[BOOL:_[0-9]+]] = const true;
-    // CHECK: switchInt(move [[BOOL]]) -> [0: [[BB_FALSE:bb[0-9]+]], otherwise: [[BB_TRUE:bb[0-9]+]]];
+    // CHECK: switchInt(const true) -> [0: [[FALSE:bb[0-9]+]], otherwise: [[TRUE:bb[0-9]+]]];
     // CHECK-NEXT: }
-    // CHECK: [[BB_FALSE]]: {
+    // CHECK: [[FALSE]]: {
     // CHECK-NEXT: _0 = const 0
     // CHECK-NEXT: goto
     // CHECK-NEXT: }
-    // CHECK: [[BB_TRUE]]: {
+    // CHECK: [[TRUE]]: {
     // CHECK-NEXT: _0 = const 1
     // CHECK-NEXT: goto
     // CHECK-NEXT: }

tests/run-make/mir-opt-bisect-limit/main.rs

@@ -1,11 +0,0 @@
-#![crate_type = "lib"]
-#![no_std]
-
-#[inline(never)]
-pub fn callee(x: u64) -> u64 {
-    x.wrapping_mul(3).wrapping_add(7)
-}
-
-pub fn caller(a: u64, b: u64) -> u64 {
-    callee(a) + callee(b)
-}

tests/run-make/mir-opt-bisect-limit/rmake.rs

@@ -1,119 +0,0 @@
-use std::path::Path;
-
-use run_make_support::{CompletedProcess, rfs, rustc};
-
-struct Case {
-    name: &'static str,
-    flags: &'static [&'static str],
-    expect_inline_dump: bool,
-    expect_running: ExpectedCount,
-    expect_not_running: ExpectedCount,
-}
-
-enum ExpectedCount {
-    Exactly(usize),
-    AtLeastOne,
-    Zero,
-}
-
-fn main() {
-    let cases = [
-        Case {
-            name: "limit0",
-            flags: &["-Zmir-opt-bisect-limit=0"],
-            expect_inline_dump: false,
-            expect_running: ExpectedCount::Exactly(0),
-            expect_not_running: ExpectedCount::AtLeastOne,
-        },
-        Case {
-            name: "limit1",
-            flags: &["-Zmir-opt-bisect-limit=1"],
-            expect_inline_dump: false,
-            expect_running: ExpectedCount::Exactly(1),
-            expect_not_running: ExpectedCount::AtLeastOne,
-        },
-        Case {
-            name: "huge_limit",
-            flags: &["-Zmir-opt-bisect-limit=1000000000"],
-            expect_inline_dump: true,
-            expect_running: ExpectedCount::AtLeastOne,
-            expect_not_running: ExpectedCount::Zero,
-        },
-        Case {
-            name: "limit0_with_force_enable_inline",
-            flags: &["-Zmir-opt-bisect-limit=0", "-Zmir-enable-passes=+Inline"],
-            expect_inline_dump: false,
-            expect_running: ExpectedCount::Exactly(0),
-            expect_not_running: ExpectedCount::AtLeastOne,
-        },
-    ];
-
-    for case in cases {
-        let (inline_dumped, running_count, not_running_count, output) =
-            compile_case(case.name, case.flags);
-
-        assert_eq!(
-            inline_dumped, case.expect_inline_dump,
-            "{}: unexpected Inline dump presence",
-            case.name
-        );
-
-        assert_expected_count(
-            running_count,
-            case.expect_running,
-            &format!("{}: running count", case.name),
-        );
-        assert_expected_count(
-            not_running_count,
-            case.expect_not_running,
-            &format!("{}: NOT running count", case.name),
-        );
-    }
-}
-
-fn compile_case(dump_dir: &str, extra_flags: &[&str]) -> (bool, usize, usize, CompletedProcess) {
-    if Path::new(dump_dir).exists() {
-        rfs::remove_dir_all(dump_dir);
-    }
-    rfs::create_dir_all(dump_dir);
-
-    let mut cmd = rustc();
-    cmd.input("main.rs")
-        .arg("--emit=mir")
-        .arg("-Zmir-opt-level=2")
-        .arg("-Copt-level=2")
-        .arg("-Zthreads=1")
-        .arg("-Zdump-mir=Inline")
-        .arg(format!("-Zdump-mir-dir={dump_dir}"));
-
-    for &flag in extra_flags {
-        cmd.arg(flag);
-    }
-
-    let output = cmd.run();
-    let (running_count, not_running_count) = bisect_line_counts(&output);
-    (has_inline_dump_file(dump_dir), running_count, not_running_count, output)
-}
-
-fn assert_expected_count(actual: usize, expected: ExpectedCount, context: &str) {
-    match expected {
-        ExpectedCount::Exactly(n) => assert_eq!(actual, n, "{context}"),
-        ExpectedCount::AtLeastOne => assert!(actual > 0, "{context}"),
-        ExpectedCount::Zero => assert_eq!(actual, 0, "{context}"),
-    }
-}
-
-fn has_inline_dump_file(dir: &str) -> bool {
-    rfs::read_dir(dir)
-        .flatten()
-        .any(|entry| entry.file_name().to_string_lossy().contains(".Inline."))
-}
-
-fn bisect_line_counts(output: &CompletedProcess) -> (usize, usize) {
-    let stderr = output.stderr_utf8();
-    let running_count =
-        stderr.lines().filter(|line| line.starts_with("BISECT: running pass (")).count();
-    let not_running_count =
-        stderr.lines().filter(|line| line.starts_with("BISECT: NOT running pass (")).count();
-    (running_count, not_running_count)
-}

tests/ui/associated-types/suggest-param-env-shadowing-incompatible-args.rs

@@ -1,18 +0,0 @@
-//@ compile-flags: -Znext-solver=globally
-
-// Regression test for https://github.com/rust-lang/rust/issues/152684.
-
-#![feature(associated_type_defaults)]
-
-trait Foo {
-    type Assoc<T = u8> = T;
-    //~^ ERROR defaults for generic parameters are not allowed here
-    fn foo() -> Self::Assoc;
-}
-impl Foo for () {
-    fn foo() -> Self::Assoc {
-        [] //~ ERROR mismatched types
-    }
-}
-
-fn main() {}

tests/ui/associated-types/suggest-param-env-shadowing-incompatible-args.stderr

@@ -1,20 +0,0 @@
-error: defaults for generic parameters are not allowed here
-  --> $DIR/suggest-param-env-shadowing-incompatible-args.rs:8:16
-   |
-LL |     type Assoc<T = u8> = T;
-   |                ^^^^^^
-
-error[E0308]: mismatched types
-  --> $DIR/suggest-param-env-shadowing-incompatible-args.rs:14:9
-   |
-LL |     fn foo() -> Self::Assoc {
-   |                 ----------- expected `<() as Foo>::Assoc` because of return type
-LL |         []
-   |         ^^ expected `u8`, found `[_; 0]`
-   |
-   = note: expected type `u8`
-             found array `[_; 0]`
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0308`.

tests/ui/attributes/malformed-attrs.rs

@@ -2,6 +2,7 @@
 // We enable a bunch of features to not get feature-gate errs in this test.
 #![deny(invalid_doc_attributes)]
 #![feature(rustc_attrs)]
+#![feature(rustc_allow_const_fn_unstable)]
 #![feature(allow_internal_unstable)]
 // FIXME(#82232, #143834): temporarily renamed to mitigate `#[align]` nameres ambiguity
 #![feature(fn_align)]

tests/ui/attributes/malformed-attrs.stderr

@@ -1,5 +1,5 @@
 error[E0539]: malformed `cfg` attribute input
-  --> $DIR/malformed-attrs.rs:106:1
+  --> $DIR/malformed-attrs.rs:107:1
    |
 LL | #[cfg]
    | ^^^^^^
@@ -10,7 +10,7 @@ LL | #[cfg]
    = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
 
 error[E0539]: malformed `cfg_attr` attribute input
-  --> $DIR/malformed-attrs.rs:108:1
+  --> $DIR/malformed-attrs.rs:109:1
    |
 LL | #[cfg_attr]
    | ^^^^^^^^^^^
@@ -21,13 +21,13 @@ LL | #[cfg_attr]
    = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg_attr-attribute>
 
 error[E0463]: can't find crate for `wloop`
-  --> $DIR/malformed-attrs.rs:214:1
+  --> $DIR/malformed-attrs.rs:215:1
    |
 LL | extern crate wloop;
    | ^^^^^^^^^^^^^^^^^^^ can't find crate
 
 error: malformed `allow` attribute input
-  --> $DIR/malformed-attrs.rs:180:1
+  --> $DIR/malformed-attrs.rs:181:1
    |
 LL | #[allow]
    | ^^^^^^^^
@@ -43,7 +43,7 @@ LL | #[allow(lint1, lint2, lint3, reason = "...")]
    |        +++++++++++++++++++++++++++++++++++++
 
 error: malformed `expect` attribute input
-  --> $DIR/malformed-attrs.rs:182:1
+  --> $DIR/malformed-attrs.rs:183:1
    |
 LL | #[expect]
    | ^^^^^^^^^
@@ -59,7 +59,7 @@ LL | #[expect(lint1, lint2, lint3, reason = "...")]
    |         +++++++++++++++++++++++++++++++++++++
 
 error: malformed `warn` attribute input
-  --> $DIR/malformed-attrs.rs:184:1
+  --> $DIR/malformed-attrs.rs:185:1
    |
 LL | #[warn]
    | ^^^^^^^
@@ -75,7 +75,7 @@ LL | #[warn(lint1, lint2, lint3, reason = "...")]
    |       +++++++++++++++++++++++++++++++++++++
 
 error: malformed `deny` attribute input
-  --> $DIR/malformed-attrs.rs:186:1
+  --> $DIR/malformed-attrs.rs:187:1
    |
 LL | #[deny]
    | ^^^^^^^
@@ -91,7 +91,7 @@ LL | #[deny(lint1, lint2, lint3, reason = "...")]
    |       +++++++++++++++++++++++++++++++++++++
 
 error: malformed `forbid` attribute input
-  --> $DIR/malformed-attrs.rs:188:1
+  --> $DIR/malformed-attrs.rs:189:1
    |
 LL | #[forbid]
    | ^^^^^^^^^
@@ -107,25 +107,25 @@ LL | #[forbid(lint1, lint2, lint3, reason = "...")]
    |         +++++++++++++++++++++++++++++++++++++
 
 error: the `#[proc_macro]` attribute is only usable with crates of the `proc-macro` crate type
-  --> $DIR/malformed-attrs.rs:103:1
+  --> $DIR/malformed-attrs.rs:104:1
    |
 LL | #[proc_macro = 18]
    | ^^^^^^^^^^^^^^^^^^
 
 error: the `#[proc_macro_attribute]` attribute is only usable with crates of the `proc-macro` crate type
-  --> $DIR/malformed-attrs.rs:120:1
+  --> $DIR/malformed-attrs.rs:121:1
    |
 LL | #[proc_macro_attribute = 19]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: the `#[proc_macro_derive]` attribute is only usable with crates of the `proc-macro` crate type
-  --> $DIR/malformed-attrs.rs:127:1
+  --> $DIR/malformed-attrs.rs:128:1
    |
 LL | #[proc_macro_derive]
    | ^^^^^^^^^^^^^^^^^^^^
 
 error[E0658]: allow_internal_unsafe side-steps the unsafe_code lint
-  --> $DIR/malformed-attrs.rs:219:1
+  --> $DIR/malformed-attrs.rs:220:1
    |
 LL | #[allow_internal_unsafe = 1]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -134,7 +134,7 @@ LL | #[allow_internal_unsafe = 1]
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0539]: malformed `windows_subsystem` attribute input
-  --> $DIR/malformed-attrs.rs:26:1
+  --> $DIR/malformed-attrs.rs:27:1
    |
 LL | #![windows_subsystem]
    | ^^^-----------------^
@@ -150,25 +150,25 @@ LL | #![windows_subsystem = "windows"]
    |                      +++++++++++
 
 error[E0539]: malformed `export_name` attribute input
-  --> $DIR/malformed-attrs.rs:29:1
+  --> $DIR/malformed-attrs.rs:30:1
    |
 LL | #[unsafe(export_name)]
    | ^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[export_name = "name"]`
 
 error: `rustc_allow_const_fn_unstable` expects a list of feature names
-  --> $DIR/malformed-attrs.rs:31:1
+  --> $DIR/malformed-attrs.rs:32:1
    |
 LL | #[rustc_allow_const_fn_unstable]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `allow_internal_unstable` expects a list of feature names
-  --> $DIR/malformed-attrs.rs:34:1
+  --> $DIR/malformed-attrs.rs:35:1
    |
 LL | #[allow_internal_unstable]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0539]: malformed `rustc_confusables` attribute input
-  --> $DIR/malformed-attrs.rs:36:1
+  --> $DIR/malformed-attrs.rs:37:1
    |
 LL | #[rustc_confusables]
    | ^^^^^^^^^^^^^^^^^^^^
@@ -177,7 +177,7 @@ LL | #[rustc_confusables]
    | help: must be of the form: `#[rustc_confusables("name1", "name2", ...)]`
 
 error: `#[rustc_confusables]` attribute cannot be used on functions
-  --> $DIR/malformed-attrs.rs:36:1
+  --> $DIR/malformed-attrs.rs:37:1
    |
 LL | #[rustc_confusables]
    | ^^^^^^^^^^^^^^^^^^^^
@@ -185,7 +185,7 @@ LL | #[rustc_confusables]
    = help: `#[rustc_confusables]` can only be applied to inherent methods
 
 error[E0539]: malformed `deprecated` attribute input
-  --> $DIR/malformed-attrs.rs:39:1
+  --> $DIR/malformed-attrs.rs:40:1
    |
 LL | #[deprecated = 5]
    | ^^^^^^^^^^^^^^^-^
@@ -193,7 +193,7 @@ LL | #[deprecated = 5]
    |                expected a string literal here
 
 error[E0539]: malformed `rustc_macro_transparency` attribute input
-  --> $DIR/malformed-attrs.rs:43:1
+  --> $DIR/malformed-attrs.rs:44:1
    |
 LL | #[rustc_macro_transparency]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -208,7 +208,7 @@ LL | #[rustc_macro_transparency = "transparent"]
    |                            +++++++++++++++
 
 error: `#[rustc_macro_transparency]` attribute cannot be used on functions
-  --> $DIR/malformed-attrs.rs:43:1
+  --> $DIR/malformed-attrs.rs:44:1
    |
 LL | #[rustc_macro_transparency]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -216,7 +216,7 @@ LL | #[rustc_macro_transparency]
    = help: `#[rustc_macro_transparency]` can only be applied to macro defs
 
 error[E0539]: malformed `repr` attribute input
-  --> $DIR/malformed-attrs.rs:46:1
+  --> $DIR/malformed-attrs.rs:47:1
    |
 LL | #[repr]
    | ^^^^^^^ expected this to be a list
@@ -224,7 +224,7 @@ LL | #[repr]
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html#representations>
 
 error[E0565]: malformed `rustc_as_ptr` attribute input
-  --> $DIR/malformed-attrs.rs:49:1
+  --> $DIR/malformed-attrs.rs:50:1
    |
 LL | #[rustc_as_ptr = 5]
    | ^^^^^^^^^^^^^^^---^
@@ -233,7 +233,7 @@ LL | #[rustc_as_ptr = 5]
    | help: must be of the form: `#[rustc_as_ptr]`
 
 error[E0539]: malformed `rustc_align` attribute input
-  --> $DIR/malformed-attrs.rs:54:1
+  --> $DIR/malformed-attrs.rs:55:1
    |
 LL | #[rustc_align]
    | ^^^^^^^^^^^^^^
@@ -242,7 +242,7 @@ LL | #[rustc_align]
    | help: must be of the form: `#[rustc_align(<alignment in bytes>)]`
 
 error[E0539]: malformed `optimize` attribute input
-  --> $DIR/malformed-attrs.rs:56:1
+  --> $DIR/malformed-attrs.rs:57:1
    |
 LL | #[optimize]
    | ^^^^^^^^^^^ expected this to be a list
@@ -257,7 +257,7 @@ LL | #[optimize(speed)]
    |           +++++++
 
 error[E0565]: malformed `cold` attribute input
-  --> $DIR/malformed-attrs.rs:58:1
+  --> $DIR/malformed-attrs.rs:59:1
    |
 LL | #[cold = 1]
    | ^^^^^^^---^
@@ -266,7 +266,7 @@ LL | #[cold = 1]
    | help: must be of the form: `#[cold]`
 
 error[E0539]: malformed `must_use` attribute input
-  --> $DIR/malformed-attrs.rs:60:1
+  --> $DIR/malformed-attrs.rs:61:1
    |
 LL | #[must_use()]
    | ^^^^^^^^^^--^
@@ -284,7 +284,7 @@ LL + #[must_use]
    |
 
 error[E0565]: malformed `no_mangle` attribute input
-  --> $DIR/malformed-attrs.rs:62:1
+  --> $DIR/malformed-attrs.rs:63:1
    |
 LL | #[no_mangle = 1]
    | ^^^^^^^^^^^^---^
@@ -293,7 +293,7 @@ LL | #[no_mangle = 1]
    | help: must be of the form: `#[no_mangle]`
 
 error[E0565]: malformed `naked` attribute input
-  --> $DIR/malformed-attrs.rs:64:1
+  --> $DIR/malformed-attrs.rs:65:1
    |
 LL | #[unsafe(naked())]
    | ^^^^^^^^^^^^^^--^^
@@ -302,7 +302,7 @@ LL | #[unsafe(naked())]
    | help: must be of the form: `#[naked]`
 
 error[E0565]: malformed `track_caller` attribute input
-  --> $DIR/malformed-attrs.rs:66:1
+  --> $DIR/malformed-attrs.rs:67:1
    |
 LL | #[track_caller()]
    | ^^^^^^^^^^^^^^--^
@@ -311,13 +311,13 @@ LL | #[track_caller()]
    | help: must be of the form: `#[track_caller]`
 
 error[E0539]: malformed `export_name` attribute input
-  --> $DIR/malformed-attrs.rs:68:1
+  --> $DIR/malformed-attrs.rs:69:1
    |
 LL | #[export_name()]
    | ^^^^^^^^^^^^^^^^ help: must be of the form: `#[export_name = "name"]`
 
 error[E0805]: malformed `used` attribute input
-  --> $DIR/malformed-attrs.rs:70:1
+  --> $DIR/malformed-attrs.rs:71:1
    |
 LL | #[used()]
    | ^^^^^^--^
@@ -335,7 +335,7 @@ LL + #[used]
    |
 
 error: `#[used]` attribute cannot be used on functions
-  --> $DIR/malformed-attrs.rs:70:1
+  --> $DIR/malformed-attrs.rs:71:1
    |
 LL | #[used()]
    | ^^^^^^^^^
@@ -343,13 +343,13 @@ LL | #[used()]
    = help: `#[used]` can only be applied to statics
 
 error[E0539]: malformed `crate_name` attribute input
-  --> $DIR/malformed-attrs.rs:73:1
+  --> $DIR/malformed-attrs.rs:74:1
    |
 LL | #[crate_name]
    | ^^^^^^^^^^^^^ help: must be of the form: `#[crate_name = "name"]`
 
 error[E0539]: malformed `target_feature` attribute input
-  --> $DIR/malformed-attrs.rs:78:1
+  --> $DIR/malformed-attrs.rs:79:1
    |
 LL | #[target_feature]
    | ^^^^^^^^^^^^^^^^^
@@ -358,7 +358,7 @@ LL | #[target_feature]
    | help: must be of the form: `#[target_feature(enable = "feat1, feat2")]`
 
 error[E0565]: malformed `export_stable` attribute input
-  --> $DIR/malformed-attrs.rs:80:1
+  --> $DIR/malformed-attrs.rs:81:1
    |
 LL | #[export_stable = 1]
    | ^^^^^^^^^^^^^^^^---^
@@ -367,7 +367,7 @@ LL | #[export_stable = 1]
    | help: must be of the form: `#[export_stable]`
 
 error[E0539]: malformed `link` attribute input
-  --> $DIR/malformed-attrs.rs:82:1
+  --> $DIR/malformed-attrs.rs:83:1
    |
 LL | #[link]
    | ^^^^^^^ expected this to be a list
@@ -375,7 +375,7 @@ LL | #[link]
    = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link-attribute>
 
 error[E0539]: malformed `link_name` attribute input
-  --> $DIR/malformed-attrs.rs:86:1
+  --> $DIR/malformed-attrs.rs:87:1
    |
 LL | #[link_name]
    | ^^^^^^^^^^^^ help: must be of the form: `#[link_name = "name"]`
@@ -383,7 +383,7 @@ LL | #[link_name]
    = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_name-attribute>
 
 error[E0539]: malformed `link_section` attribute input
-  --> $DIR/malformed-attrs.rs:90:1
+  --> $DIR/malformed-attrs.rs:91:1
    |
 LL | #[link_section]
    | ^^^^^^^^^^^^^^^ help: must be of the form: `#[link_section = "name"]`
@@ -391,7 +391,7 @@ LL | #[link_section]
    = note: for more information, visit <https://doc.rust-lang.org/reference/abi.html#the-link_section-attribute>
 
 error[E0539]: malformed `coverage` attribute input
-  --> $DIR/malformed-attrs.rs:92:1
+  --> $DIR/malformed-attrs.rs:93:1
    |
 LL | #[coverage]
    | ^^^^^^^^^^^ this attribute is only valid with either `on` or `off` as an argument
@@ -404,13 +404,13 @@ LL | #[coverage(on)]
    |           ++++
 
 error[E0539]: malformed `sanitize` attribute input
-  --> $DIR/malformed-attrs.rs:94:1
+  --> $DIR/malformed-attrs.rs:95:1
    |
 LL | #[sanitize]
    | ^^^^^^^^^^^ expected this to be a list
 
 error[E0565]: malformed `no_implicit_prelude` attribute input
-  --> $DIR/malformed-attrs.rs:99:1
+  --> $DIR/malformed-attrs.rs:100:1
    |
 LL | #[no_implicit_prelude = 23]
    | ^^^^^^^^^^^^^^^^^^^^^^----^
@@ -419,7 +419,7 @@ LL | #[no_implicit_prelude = 23]
    | help: must be of the form: `#[no_implicit_prelude]`
 
 error[E0565]: malformed `proc_macro` attribute input
-  --> $DIR/malformed-attrs.rs:103:1
+  --> $DIR/malformed-attrs.rs:104:1
    |
 LL | #[proc_macro = 18]
    | ^^^^^^^^^^^^^----^
@@ -428,7 +428,7 @@ LL | #[proc_macro = 18]
    | help: must be of the form: `#[proc_macro]`
 
 error[E0539]: malformed `instruction_set` attribute input
-  --> $DIR/malformed-attrs.rs:110:1
+  --> $DIR/malformed-attrs.rs:111:1
    |
 LL | #[instruction_set]
    | ^^^^^^^^^^^^^^^^^^
@@ -439,7 +439,7 @@ LL | #[instruction_set]
    = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/codegen.html#the-instruction_set-attribute>
 
 error[E0539]: malformed `patchable_function_entry` attribute input
-  --> $DIR/malformed-attrs.rs:112:1
+  --> $DIR/malformed-attrs.rs:113:1
    |
 LL | #[patchable_function_entry]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -448,7 +448,7 @@ LL | #[patchable_function_entry]
    | help: must be of the form: `#[patchable_function_entry(prefix_nops = m, entry_nops = n)]`
 
 error[E0565]: malformed `coroutine` attribute input
-  --> $DIR/malformed-attrs.rs:115:5
+  --> $DIR/malformed-attrs.rs:116:5
    |
 LL |     #[coroutine = 63] || {}
    |     ^^^^^^^^^^^^----^
@@ -457,7 +457,7 @@ LL |     #[coroutine = 63] || {}
    |     help: must be of the form: `#[coroutine]`
 
 error[E0565]: malformed `proc_macro_attribute` attribute input
-  --> $DIR/malformed-attrs.rs:120:1
+  --> $DIR/malformed-attrs.rs:121:1
    |
 LL | #[proc_macro_attribute = 19]
    | ^^^^^^^^^^^^^^^^^^^^^^^----^
@@ -466,7 +466,7 @@ LL | #[proc_macro_attribute = 19]
    | help: must be of the form: `#[proc_macro_attribute]`
 
 error[E0539]: malformed `must_use` attribute input
-  --> $DIR/malformed-attrs.rs:123:1
+  --> $DIR/malformed-attrs.rs:124:1
    |
 LL | #[must_use = 1]
    | ^^^^^^^^^^^^^-^
@@ -484,7 +484,7 @@ LL + #[must_use]
    |
 
 error[E0539]: malformed `proc_macro_derive` attribute input
-  --> $DIR/malformed-attrs.rs:127:1
+  --> $DIR/malformed-attrs.rs:128:1
    |
 LL | #[proc_macro_derive]
    | ^^^^^^^^^^^^^^^^^^^^ expected this to be a list
@@ -498,7 +498,7 @@ LL | #[proc_macro_derive(TraitName, attributes(name1, name2, ...))]
    |                    ++++++++++++++++++++++++++++++++++++++++++
 
 error[E0539]: malformed `rustc_layout_scalar_valid_range_start` attribute input
-  --> $DIR/malformed-attrs.rs:132:1
+  --> $DIR/malformed-attrs.rs:133:1
    |
 LL | #[rustc_layout_scalar_valid_range_start]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -507,7 +507,7 @@ LL | #[rustc_layout_scalar_valid_range_start]
    | help: must be of the form: `#[rustc_layout_scalar_valid_range_start(start)]`
 
 error[E0539]: malformed `rustc_layout_scalar_valid_range_end` attribute input
-  --> $DIR/malformed-attrs.rs:134:1
+  --> $DIR/malformed-attrs.rs:135:1
    |
 LL | #[rustc_layout_scalar_valid_range_end]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -516,7 +516,7 @@ LL | #[rustc_layout_scalar_valid_range_end]
    | help: must be of the form: `#[rustc_layout_scalar_valid_range_end(end)]`
 
 error[E0539]: malformed `must_not_suspend` attribute input
-  --> $DIR/malformed-attrs.rs:136:1
+  --> $DIR/malformed-attrs.rs:137:1
    |
 LL | #[must_not_suspend()]
    | ^^^^^^^^^^^^^^^^^^--^
@@ -532,7 +532,7 @@ LL + #[must_not_suspend]
    |
 
 error[E0539]: malformed `cfi_encoding` attribute input
-  --> $DIR/malformed-attrs.rs:138:1
+  --> $DIR/malformed-attrs.rs:139:1
    |
 LL | #[cfi_encoding = ""]
    | ^^^^^^^^^^^^^^^^^--^
@@ -541,7 +541,7 @@ LL | #[cfi_encoding = ""]
    | help: must be of the form: `#[cfi_encoding = "encoding"]`
 
 error[E0565]: malformed `marker` attribute input
-  --> $DIR/malformed-attrs.rs:157:1
+  --> $DIR/malformed-attrs.rs:158:1
    |
 LL | #[marker = 3]
    | ^^^^^^^^^---^
@@ -550,7 +550,7 @@ LL | #[marker = 3]
    | help: must be of the form: `#[marker]`
 
 error[E0565]: malformed `fundamental` attribute input
-  --> $DIR/malformed-attrs.rs:159:1
+  --> $DIR/malformed-attrs.rs:160:1
    |
 LL | #[fundamental()]
    | ^^^^^^^^^^^^^--^
@@ -559,7 +559,7 @@ LL | #[fundamental()]
    | help: must be of the form: `#[fundamental]`
 
 error[E0565]: malformed `ffi_pure` attribute input
-  --> $DIR/malformed-attrs.rs:167:5
+  --> $DIR/malformed-attrs.rs:168:5
    |
 LL |     #[unsafe(ffi_pure = 1)]
    |     ^^^^^^^^^^^^^^^^^^---^^
@@ -568,7 +568,7 @@ LL |     #[unsafe(ffi_pure = 1)]
    |     help: must be of the form: `#[ffi_pure]`
 
 error[E0539]: malformed `link_ordinal` attribute input
-  --> $DIR/malformed-attrs.rs:169:5
+  --> $DIR/malformed-attrs.rs:170:5
    |
 LL |     #[link_ordinal]
    |     ^^^^^^^^^^^^^^^
@@ -579,7 +579,7 @@ LL |     #[link_ordinal]
    = note: for more information, visit <https://doc.rust-lang.org/reference/items/external-blocks.html#the-link_ordinal-attribute>
 
 error[E0565]: malformed `ffi_const` attribute input
-  --> $DIR/malformed-attrs.rs:173:5
+  --> $DIR/malformed-attrs.rs:174:5
    |
 LL |     #[unsafe(ffi_const = 1)]
    |     ^^^^^^^^^^^^^^^^^^^---^^
@@ -588,13 +588,13 @@ LL |     #[unsafe(ffi_const = 1)]
    |     help: must be of the form: `#[ffi_const]`
 
 error[E0539]: malformed `linkage` attribute input
-  --> $DIR/malformed-attrs.rs:175:5
+  --> $DIR/malformed-attrs.rs:176:5
    |
 LL |     #[linkage]
    |     ^^^^^^^^^^ expected this to be of the form `linkage = "..."`
 
 error[E0539]: malformed `debugger_visualizer` attribute input
-  --> $DIR/malformed-attrs.rs:190:1
+  --> $DIR/malformed-attrs.rs:191:1
    |
 LL | #[debugger_visualizer]
    | ^^^^^^^^^^^^^^^^^^^^^^
@@ -605,7 +605,7 @@ LL | #[debugger_visualizer]
    = note: for more information, visit <https://doc.rust-lang.org/reference/attributes/debugger.html#the-debugger_visualizer-attribute>
 
 error[E0565]: malformed `automatically_derived` attribute input
-  --> $DIR/malformed-attrs.rs:192:1
+  --> $DIR/malformed-attrs.rs:193:1
    |
 LL | #[automatically_derived = 18]
    | ^^^^^^^^^^^^^^^^^^^^^^^^----^
@@ -614,7 +614,7 @@ LL | #[automatically_derived = 18]
    | help: must be of the form: `#[automatically_derived]`
 
 error[E0565]: malformed `non_exhaustive` attribute input
-  --> $DIR/malformed-attrs.rs:200:1
+  --> $DIR/malformed-attrs.rs:201:1
    |
 LL | #[non_exhaustive = 1]
    | ^^^^^^^^^^^^^^^^^---^
@@ -623,7 +623,7 @@ LL | #[non_exhaustive = 1]
    | help: must be of the form: `#[non_exhaustive]`
 
 error[E0565]: malformed `thread_local` attribute input
-  --> $DIR/malformed-attrs.rs:206:1
+  --> $DIR/malformed-attrs.rs:207:1
    |
 LL | #[thread_local()]
    | ^^^^^^^^^^^^^^--^
@@ -632,7 +632,7 @@ LL | #[thread_local()]
    | help: must be of the form: `#[thread_local]`
 
 error[E0565]: malformed `no_link` attribute input
-  --> $DIR/malformed-attrs.rs:210:1
+  --> $DIR/malformed-attrs.rs:211:1
    |
 LL | #[no_link()]
    | ^^^^^^^^^--^
@@ -641,7 +641,7 @@ LL | #[no_link()]
    | help: must be of the form: `#[no_link]`
 
 error[E0539]: malformed `macro_use` attribute input
-  --> $DIR/malformed-attrs.rs:212:1
+  --> $DIR/malformed-attrs.rs:213:1
    |
 LL | #[macro_use = 1]
    | ^^^^^^^^^^^^---^
@@ -659,7 +659,7 @@ LL + #[macro_use]
    |
 
 error[E0539]: malformed `macro_export` attribute input
-  --> $DIR/malformed-attrs.rs:217:1
+  --> $DIR/malformed-attrs.rs:218:1
    |
 LL | #[macro_export = 18]
    | ^^^^^^^^^^^^^^^----^
@@ -676,7 +676,7 @@ LL + #[macro_export]
    |
 
 error[E0565]: malformed `allow_internal_unsafe` attribute input
-  --> $DIR/malformed-attrs.rs:219:1
+  --> $DIR/malformed-attrs.rs:220:1
    |
 LL | #[allow_internal_unsafe = 1]
    | ^^^^^^^^^^^^^^^^^^^^^^^^---^
@@ -685,7 +685,7 @@ LL | #[allow_internal_unsafe = 1]
    | help: must be of the form: `#[allow_internal_unsafe]`
 
 error: attribute should be applied to `const fn`
-  --> $DIR/malformed-attrs.rs:31:1
+  --> $DIR/malformed-attrs.rs:32:1
    |
 LL |   #[rustc_allow_const_fn_unstable]
    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -697,7 +697,7 @@ LL | | }
    | |_- not a `const fn`
 
 warning: attribute should be applied to an `extern` block with non-Rust ABI
-  --> $DIR/malformed-attrs.rs:82:1
+  --> $DIR/malformed-attrs.rs:83:1
    |
 LL |   #[link]
    |   ^^^^^^^
@@ -712,19 +712,19 @@ LL | | }
    = note: requested on the command line with `-W unused-attributes`
 
 error: `#[repr(align(...))]` is not supported on functions
-  --> $DIR/malformed-attrs.rs:46:1
+  --> $DIR/malformed-attrs.rs:47:1
    |
 LL | #[repr]
    | ^^^^^^^
    |
 help: use `#[rustc_align(...)]` instead
-  --> $DIR/malformed-attrs.rs:46:1
+  --> $DIR/malformed-attrs.rs:47:1
    |
 LL | #[repr]
    | ^^^^^^^
 
 warning: missing options for `on_unimplemented` attribute
-  --> $DIR/malformed-attrs.rs:142:1
+  --> $DIR/malformed-attrs.rs:143:1
    |
 LL | #[diagnostic::on_unimplemented]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -733,7 +733,7 @@ LL | #[diagnostic::on_unimplemented]
    = note: `#[warn(malformed_diagnostic_attributes)]` (part of `#[warn(unknown_or_malformed_diagnostic_attributes)]`) on by default
 
 warning: malformed `on_unimplemented` attribute
-  --> $DIR/malformed-attrs.rs:144:1
+  --> $DIR/malformed-attrs.rs:145:1
    |
 LL | #[diagnostic::on_unimplemented = 1]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ invalid option found here
@@ -741,7 +741,7 @@ LL | #[diagnostic::on_unimplemented = 1]
    = help: only `message`, `note` and `label` are allowed as options
 
 error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
-  --> $DIR/malformed-attrs.rs:41:1
+  --> $DIR/malformed-attrs.rs:42:1
    |
 LL | #[doc]
    | ^^^^^^
@@ -753,7 +753,7 @@ LL | #![deny(invalid_doc_attributes)]
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
 error: valid forms for the attribute are `#[inline(always)]`, `#[inline(never)]`, and `#[inline]`
-  --> $DIR/malformed-attrs.rs:51:1
+  --> $DIR/malformed-attrs.rs:52:1
    |
 LL | #[inline = 5]
    | ^^^^^^^^^^^^^
@@ -763,13 +763,13 @@ LL | #[inline = 5]
    = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![crate_name]`
-  --> $DIR/malformed-attrs.rs:73:1
+  --> $DIR/malformed-attrs.rs:74:1
    |
 LL | #[crate_name]
    | ^^^^^^^^^^^^^
    |
 note: this attribute does not have an `!`, which means it is applied to this function
-  --> $DIR/malformed-attrs.rs:114:1
+  --> $DIR/malformed-attrs.rs:115:1
    |
 LL | / fn test() {
 LL | |     #[coroutine = 63] || {}
@@ -778,13 +778,13 @@ LL | | }
    | |_^
 
 error: valid forms for the attribute are `#[doc = "string"]`, `#[doc(alias)]`, `#[doc(attribute)]`, `#[doc(auto_cfg)]`, `#[doc(cfg)]`, `#[doc(fake_variadic)]`, `#[doc(hidden)]`, `#[doc(html_favicon_url)]`, `#[doc(html_logo_url)]`, `#[doc(html_no_source)]`, `#[doc(html_playground_url)]`, `#[doc(html_root_url)]`, `#[doc(include)]`, `#[doc(inline)]`, `#[doc(issue_tracker_base_url)]`, `#[doc(keyword)]`, `#[doc(masked)]`, `#[doc(no_default_passes)]`, `#[doc(no_inline)]`, `#[doc(notable_trait)]`, `#[doc(passes)]`, `#[doc(plugins)]`, `#[doc(rust_logo)]`, `#[doc(search_unbox)]`, `#[doc(spotlight)]`, and `#[doc(test)]`
-  --> $DIR/malformed-attrs.rs:76:1
+  --> $DIR/malformed-attrs.rs:77:1
    |
 LL | #[doc]
    | ^^^^^^
 
 warning: `#[link_name]` attribute cannot be used on functions
-  --> $DIR/malformed-attrs.rs:86:1
+  --> $DIR/malformed-attrs.rs:87:1
    |
 LL | #[link_name]
    | ^^^^^^^^^^^^
@@ -793,7 +793,7 @@ LL | #[link_name]
    = help: `#[link_name]` can be applied to foreign functions and foreign statics
 
 error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
-  --> $DIR/malformed-attrs.rs:96:1
+  --> $DIR/malformed-attrs.rs:97:1
    |
 LL | #[ignore()]
    | ^^^^^^^^^^^
@@ -802,7 +802,7 @@ LL | #[ignore()]
    = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
 
 warning: `#[no_implicit_prelude]` attribute cannot be used on functions
-  --> $DIR/malformed-attrs.rs:99:1
+  --> $DIR/malformed-attrs.rs:100:1
    |
 LL | #[no_implicit_prelude = 23]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -811,13 +811,13 @@ LL | #[no_implicit_prelude = 23]
    = help: `#[no_implicit_prelude]` can be applied to crates and modules
 
 warning: `#[diagnostic::do_not_recommend]` does not expect any arguments
-  --> $DIR/malformed-attrs.rs:151:1
+  --> $DIR/malformed-attrs.rs:152:1
    |
 LL | #[diagnostic::do_not_recommend()]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[automatically_derived]` attribute cannot be used on modules
-  --> $DIR/malformed-attrs.rs:192:1
+  --> $DIR/malformed-attrs.rs:193:1
    |
 LL | #[automatically_derived = 18]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -826,7 +826,7 @@ LL | #[automatically_derived = 18]
    = help: `#[automatically_derived]` can only be applied to trait impl blocks
 
 error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
-  --> $DIR/malformed-attrs.rs:226:1
+  --> $DIR/malformed-attrs.rs:227:1
    |
 LL | #[ignore = 1]
    | ^^^^^^^^^^^^^
@@ -835,7 +835,7 @@ LL | #[ignore = 1]
    = note: for more information, see issue #57571 <https://github.com/rust-lang/rust/issues/57571>
 
 error[E0308]: mismatched types
-  --> $DIR/malformed-attrs.rs:115:23
+  --> $DIR/malformed-attrs.rs:116:23
    |
 LL | fn test() {
    |          - help: a return type might be missing here: `-> _`
@@ -843,7 +843,7 @@ LL |     #[coroutine = 63] || {}
    |                       ^^^^^ expected `()`, found coroutine
    |
    = note: expected unit type `()`
-              found coroutine `{coroutine@$DIR/malformed-attrs.rs:115:23: 115:25}`
+              found coroutine `{coroutine@$DIR/malformed-attrs.rs:116:23: 116:25}`
 
 error: aborting due to 75 previous errors; 8 warnings emitted
 
@@ -851,7 +851,7 @@ Some errors have detailed explanations: E0308, E0463, E0539, E0565, E0658, E0805
 For more information about an error, try `rustc --explain E0308`.
 Future incompatibility report: Future breakage diagnostic:
 error: valid forms for the attribute are `#[inline(always)]`, `#[inline(never)]`, and `#[inline]`
-  --> $DIR/malformed-attrs.rs:51:1
+  --> $DIR/malformed-attrs.rs:52:1
    |
 LL | #[inline = 5]
    | ^^^^^^^^^^^^^
@@ -862,7 +862,7 @@ LL | #[inline = 5]
 
 Future breakage diagnostic:
 error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
-  --> $DIR/malformed-attrs.rs:96:1
+  --> $DIR/malformed-attrs.rs:97:1
    |
 LL | #[ignore()]
    | ^^^^^^^^^^^
@@ -873,7 +873,7 @@ LL | #[ignore()]
 
 Future breakage diagnostic:
 error: valid forms for the attribute are `#[ignore = "reason"]` and `#[ignore]`
-  --> $DIR/malformed-attrs.rs:226:1
+  --> $DIR/malformed-attrs.rs:227:1
    |
 LL | #[ignore = 1]
    | ^^^^^^^^^^^^^

tests/ui/consts/precise-drop-allow-const-fn-unstable.rs

@@ -2,7 +2,7 @@
 //@ compile-flags: --crate-type=lib -Cinstrument-coverage  -Zno-profiler-runtime
 //@[allow] check-pass
 
-#![feature(staged_api, rustc_attrs)]
+#![feature(staged_api, rustc_allow_const_fn_unstable)]
 #![stable(feature = "rust_test", since = "1.0.0")]
 
 #[stable(feature = "rust_test", since = "1.0.0")]

tests/ui/feature-gates/feature-gate-final-associated-functions.stderr

@@ -4,7 +4,7 @@ error[E0658]: `final` on trait functions is experimental
 LL |     final fn bar() {}
    |     ^^^^^
    |
-   = note: see issue #131179 <https://github.com/rust-lang/rust/issues/131179> for more information
+   = note: see issue #1 <https://github.com/rust-lang/rust/issues/1> for more information
    = help: add `#![feature(final_associated_functions)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 

tests/ui/feature-gates/feature-gate-rustc-allow-const-fn-unstable.rs

@@ -1,6 +1,6 @@
 #![allow(unused_macros)]
 
-#[rustc_allow_const_fn_unstable()] //~ ERROR use of an internal attribute
+#[rustc_allow_const_fn_unstable()] //~ ERROR rustc_allow_const_fn_unstable side-steps
 const fn foo() { }
 
 fn main() {}

tests/ui/feature-gates/feature-gate-rustc-allow-const-fn-unstable.stderr

@@ -1,12 +1,12 @@
-error[E0658]: use of an internal attribute
+error[E0658]: rustc_allow_const_fn_unstable side-steps feature gating and stability checks
   --> $DIR/feature-gate-rustc-allow-const-fn-unstable.rs:3:1
    |
 LL | #[rustc_allow_const_fn_unstable()]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable
-   = note: the `#[rustc_allow_const_fn_unstable]` attribute is an internal implementation detail that will never be stable
-   = note: rustc_allow_const_fn_unstable side-steps feature gating and stability checks
+   = note: see issue #69399 <https://github.com/rust-lang/rust/issues/69399> for more information
+   = help: add `#![feature(rustc_allow_const_fn_unstable)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error: aborting due to 1 previous error
 

tests/ui/imports/overwrite-different-vis-3.rs

@@ -1,14 +0,0 @@
-// Regression test for issue #152606.
-
-//@ check-pass
-
-mod outer {
-    mod inner {
-        use super::*; // should go before the ambiguous glob imports
-    }
-
-    use crate::*;
-    pub use crate::*;
-}
-
-fn main() {}

tests/ui/lifetimes/mut-ref-owned-suggestion.rs

@@ -1,29 +0,0 @@
-//! Regression test for <https://github.com/rust-lang/rust/issues/150077>
-//! Tests that `&mut T` suggests `T`, not `mut T`, `&mut str` suggests `String`, not `str`,
-//! when recommending an owned value.
-fn with_fn(_f: impl Fn() -> &mut ()) {}
-//~^ ERROR: missing lifetime specifier
-
-fn with_ref_mut_str(_f: impl Fn() -> &mut str) {}
-//~^ ERROR: missing lifetime specifier
-
-fn with_fn_has_return(_f: impl Fn() -> &mut ()) -> i32 {
-    //~^ ERROR: missing lifetime specifier
-    2
-}
-
-fn with_dyn(_f: Box<dyn Fn() -> &mut i32>) {}
-//~^ ERROR: missing lifetime specifier
-
-fn trait_bound<F: Fn() -> &mut i32>(_f: F) {}
-//~^ ERROR: missing lifetime specifier
-
-fn nested_result(_f: impl Fn() -> Result<&mut i32, ()>) {}
-//~^ ERROR: missing lifetime specifier
-
-struct Holder<F: Fn() -> &mut i32> {
-    //~^ ERROR: missing lifetime specifier
-    f: F,
-}
-
-fn main() {}

tests/ui/lifetimes/mut-ref-owned-suggestion.stderr

@@ -1,137 +0,0 @@
-error[E0106]: missing lifetime specifier
-  --> $DIR/mut-ref-owned-suggestion.rs:4:29
-   |
-LL | fn with_fn(_f: impl Fn() -> &mut ()) {}
-   |                             ^ expected named lifetime parameter
-   |
-   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
-   |
-LL | fn with_fn(_f: impl Fn() -> &'static mut ()) {}
-   |                              +++++++
-help: instead, you are more likely to want to return an owned value
-   |
-LL - fn with_fn(_f: impl Fn() -> &mut ()) {}
-LL + fn with_fn(_f: impl Fn() -> ()) {}
-   |
-
-error[E0106]: missing lifetime specifier
-  --> $DIR/mut-ref-owned-suggestion.rs:7:38
-   |
-LL | fn with_ref_mut_str(_f: impl Fn() -> &mut str) {}
-   |                                      ^ expected named lifetime parameter
-   |
-   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
-   |
-LL | fn with_ref_mut_str(_f: impl Fn() -> &'static mut str) {}
-   |                                       +++++++
-help: instead, you are more likely to want to return an owned value
-   |
-LL - fn with_ref_mut_str(_f: impl Fn() -> &mut str) {}
-LL + fn with_ref_mut_str(_f: impl Fn() -> String) {}
-   |
-
-error[E0106]: missing lifetime specifier
-  --> $DIR/mut-ref-owned-suggestion.rs:10:40
-   |
-LL | fn with_fn_has_return(_f: impl Fn() -> &mut ()) -> i32 {
-   |                                        ^ expected named lifetime parameter
-   |
-   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-   = note: for more information on higher-ranked polymorphism, visit https://doc.rust-lang.org/nomicon/hrtb.html
-help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
-   |
-LL | fn with_fn_has_return(_f: impl Fn() -> &'static mut ()) -> i32 {
-   |                                         +++++++
-help: consider making the bound lifetime-generic with a new `'a` lifetime
-   |
-LL - fn with_fn_has_return(_f: impl Fn() -> &mut ()) -> i32 {
-LL + fn with_fn_has_return(_f: impl for<'a> Fn() -> &'a ()) -> i32 {
-   |
-help: consider introducing a named lifetime parameter
-   |
-LL - fn with_fn_has_return(_f: impl Fn() -> &mut ()) -> i32 {
-LL + fn with_fn_has_return<'a>(_f: impl Fn() -> &'a ()) -> i32 {
-   |
-help: alternatively, you might want to return an owned value
-   |
-LL - fn with_fn_has_return(_f: impl Fn() -> &mut ()) -> i32 {
-LL + fn with_fn_has_return(_f: impl Fn() -> ()) -> i32 {
-   |
-
-error[E0106]: missing lifetime specifier
-  --> $DIR/mut-ref-owned-suggestion.rs:15:33
-   |
-LL | fn with_dyn(_f: Box<dyn Fn() -> &mut i32>) {}
-   |                                 ^ expected named lifetime parameter
-   |
-   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
-   |
-LL | fn with_dyn(_f: Box<dyn Fn() -> &'static mut i32>) {}
-   |                                  +++++++
-help: instead, you are more likely to want to return an owned value
-   |
-LL - fn with_dyn(_f: Box<dyn Fn() -> &mut i32>) {}
-LL + fn with_dyn(_f: Box<dyn Fn() -> i32>) {}
-   |
-
-error[E0106]: missing lifetime specifier
-  --> $DIR/mut-ref-owned-suggestion.rs:18:27
-   |
-LL | fn trait_bound<F: Fn() -> &mut i32>(_f: F) {}
-   |                           ^ expected named lifetime parameter
-   |
-   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
-   |
-LL | fn trait_bound<F: Fn() -> &'static mut i32>(_f: F) {}
-   |                            +++++++
-help: instead, you are more likely to want to change the argument to be borrowed...
-   |
-LL | fn trait_bound<F: Fn() -> &mut i32>(_f: &F) {}
-   |                                         +
-help: ...or alternatively, you might want to return an owned value
-   |
-LL - fn trait_bound<F: Fn() -> &mut i32>(_f: F) {}
-LL + fn trait_bound<F: Fn() -> i32>(_f: F) {}
-   |
-
-error[E0106]: missing lifetime specifier
-  --> $DIR/mut-ref-owned-suggestion.rs:21:42
-   |
-LL | fn nested_result(_f: impl Fn() -> Result<&mut i32, ()>) {}
-   |                                          ^ expected named lifetime parameter
-   |
-   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
-   |
-LL | fn nested_result(_f: impl Fn() -> Result<&'static mut i32, ()>) {}
-   |                                           +++++++
-help: instead, you are more likely to want to return an owned value
-   |
-LL - fn nested_result(_f: impl Fn() -> Result<&mut i32, ()>) {}
-LL + fn nested_result(_f: impl Fn() -> Result<i32, ()>) {}
-   |
-
-error[E0106]: missing lifetime specifier
-  --> $DIR/mut-ref-owned-suggestion.rs:24:26
-   |
-LL | struct Holder<F: Fn() -> &mut i32> {
-   |                          ^ expected named lifetime parameter
-   |
-   = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
-help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
-   |
-LL | struct Holder<F: Fn() -> &'static mut i32> {
-   |                           +++++++
-help: instead, you are more likely to want to return an owned value
-   |
-LL - struct Holder<F: Fn() -> &mut i32> {
-LL + struct Holder<F: Fn() -> i32> {
-   |
-
-error: aborting due to 7 previous errors
-
-For more information about this error, try `rustc --explain E0106`.

tests/ui/lifetimes/trait-impl-mismatch-elided-lifetime-issue-65866.rs

@@ -1,49 +0,0 @@
-// Regression test for https://github.com/rust-lang/rust/issues/65866.
-
-mod plain {
-    struct Foo;
-
-    struct Re<'a> {
-        _data: &'a u16,
-    }
-
-    trait Bar {
-        fn bar(&self, r: &mut Re);
-        //~^ NOTE expected
-        //~| NOTE `Re` here is elided as `Re<'_>`
-    }
-
-    impl Bar for Foo {
-        fn bar<'a, 'b>(&'a self, _r: &'b mut Re<'a>) {}
-        //~^ ERROR `impl` item signature doesn't match `trait` item signature
-        //~| NOTE expected signature
-        //~| NOTE found
-        //~| HELP the lifetime requirements
-        //~| HELP verify the lifetime relationships
-    }
-}
-
-mod with_type_args {
-    struct Foo;
-
-    struct Re<'a, T> {
-        _data: (&'a u16, T),
-    }
-
-    trait Bar {
-        fn bar(&self, r: &mut Re<u8>);
-        //~^ NOTE expected
-        //~| NOTE `Re` here is elided as `Re<'_, u8>`
-    }
-
-    impl Bar for Foo {
-        fn bar<'a, 'b>(&'a self, _r: &'b mut Re<'a, u8>) {}
-        //~^ ERROR `impl` item signature doesn't match `trait` item signature
-        //~| NOTE expected signature
-        //~| NOTE found
-        //~| HELP the lifetime requirements
-        //~| HELP verify the lifetime relationships
-    }
-}
-
-fn main() {}

tests/ui/lifetimes/trait-impl-mismatch-elided-lifetime-issue-65866.stderr

@@ -1,40 +0,0 @@
-error: `impl` item signature doesn't match `trait` item signature
-  --> $DIR/trait-impl-mismatch-elided-lifetime-issue-65866.rs:17:9
-   |
-LL |         fn bar(&self, r: &mut Re);
-   |         -------------------------- expected `fn(&'1 plain::Foo, &'2 mut plain::Re<'3>)`
-...
-LL |         fn bar<'a, 'b>(&'a self, _r: &'b mut Re<'a>) {}
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found `fn(&'1 plain::Foo, &'2 mut plain::Re<'1>)`
-   |
-   = note: expected signature `fn(&'1 plain::Foo, &'2 mut plain::Re<'3>)`
-              found signature `fn(&'1 plain::Foo, &'2 mut plain::Re<'1>)`
-   = help: the lifetime requirements from the `impl` do not correspond to the requirements in the `trait`
-   = help: verify the lifetime relationships in the `trait` and `impl` between the `self` argument, the other inputs and its output
-note: `Re` here is elided as `Re<'_>`
-  --> $DIR/trait-impl-mismatch-elided-lifetime-issue-65866.rs:11:31
-   |
-LL |         fn bar(&self, r: &mut Re);
-   |                               ^^
-
-error: `impl` item signature doesn't match `trait` item signature
-  --> $DIR/trait-impl-mismatch-elided-lifetime-issue-65866.rs:40:9
-   |
-LL |         fn bar(&self, r: &mut Re<u8>);
-   |         ------------------------------ expected `fn(&'1 with_type_args::Foo, &'2 mut with_type_args::Re<'3, u8>)`
-...
-LL |         fn bar<'a, 'b>(&'a self, _r: &'b mut Re<'a, u8>) {}
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found `fn(&'1 with_type_args::Foo, &'2 mut with_type_args::Re<'1, u8>)`
-   |
-   = note: expected signature `fn(&'1 with_type_args::Foo, &'2 mut with_type_args::Re<'3, u8>)`
-              found signature `fn(&'1 with_type_args::Foo, &'2 mut with_type_args::Re<'1, u8>)`
-   = help: the lifetime requirements from the `impl` do not correspond to the requirements in the `trait`
-   = help: verify the lifetime relationships in the `trait` and `impl` between the `self` argument, the other inputs and its output
-note: `Re` here is elided as `Re<'_, u8>`
-  --> $DIR/trait-impl-mismatch-elided-lifetime-issue-65866.rs:34:31
-   |
-LL |         fn bar(&self, r: &mut Re<u8>);
-   |                               ^^
-
-error: aborting due to 2 previous errors
-

tests/ui/proc-macro/pretty-print-hack-hide.rs

@@ -0,0 +1,12 @@
+//@ proc-macro: test-macros.rs
+//@ compile-flags: -Z span-debug
+//@ check-pass
+
+#![no_std] // Don't load unnecessary hygiene information from std
+extern crate std;
+
+#[macro_use] extern crate test_macros;
+
+include!("pretty-print-hack/rental-0.5.6/src/lib.rs");
+
+fn main() {}

tests/ui/proc-macro/pretty-print-hack-hide.stdout

@@ -0,0 +1,21 @@
+PRINT-DERIVE INPUT (DISPLAY): enum ProceduralMasqueradeDummyType { Input }
+PRINT-DERIVE INPUT (DEBUG): TokenStream [
+    Ident {
+        ident: "enum",
+        span: $DIR/pretty-print-hack/rental-0.5.6/src/lib.rs:4:1: 4:5 (#0),
+    },
+    Ident {
+        ident: "ProceduralMasqueradeDummyType",
+        span: $DIR/pretty-print-hack/rental-0.5.6/src/lib.rs:4:6: 4:35 (#0),
+    },
+    Group {
+        delimiter: Brace,
+        stream: TokenStream [
+            Ident {
+                ident: "Input",
+                span: $DIR/pretty-print-hack/rental-0.5.6/src/lib.rs:13:5: 13:10 (#0),
+            },
+        ],
+        span: $DIR/pretty-print-hack/rental-0.5.6/src/lib.rs:4:36: 14:2 (#0),
+    },
+]

tests/ui/proc-macro/pretty-print-hack-show.local.stderr

@@ -0,0 +1,6 @@
+error: using an old version of `rental`
+   |
+   = note: older versions of the `rental` crate no longer compile; please update to `rental` v0.5.6, or switch to one of the `rental` alternatives
+
+error: aborting due to 1 previous error
+

tests/ui/proc-macro/pretty-print-hack-show.remapped.stderr

@@ -0,0 +1,6 @@
+error: using an old version of `rental`
+   |
+   = note: older versions of the `rental` crate no longer compile; please update to `rental` v0.5.6, or switch to one of the `rental` alternatives
+
+error: aborting due to 1 previous error
+

tests/ui/proc-macro/pretty-print-hack-show.rs

@@ -0,0 +1,21 @@
+//@ proc-macro: test-macros.rs
+//@ compile-flags: -Z span-debug
+//@ revisions: local remapped
+//@ [remapped] remap-src-base
+
+#![no_std] // Don't load unnecessary hygiene information from std
+extern crate std;
+
+#[macro_use] extern crate test_macros;
+
+mod first {
+    include!("pretty-print-hack/allsorts-rental-0.5.6/src/lib.rs");
+}
+
+mod second {
+    include!("pretty-print-hack/rental-0.5.5/src/lib.rs");
+}
+
+fn main() {}
+
+//~? ERROR using an old version of `rental`

tests/ui/proc-macro/pretty-print-hack/allsorts-rental-0.5.6/src/lib.rs

@@ -0,0 +1,14 @@
+//@ ignore-auxiliary (used by `../../../pretty-print-hack-show.rs`)
+
+#[derive(Print)]
+enum ProceduralMasqueradeDummyType {
+//~^ ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+    Input
+}

tests/ui/proc-macro/pretty-print-hack/rental-0.5.5/src/lib.rs

@@ -0,0 +1,14 @@
+//@ ignore-auxiliary (used by `../../../pretty-print-hack-show.rs`)
+
+#[derive(Print)]
+enum ProceduralMasqueradeDummyType {
+//~^ ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+    Input
+}

tests/ui/proc-macro/pretty-print-hack/rental-0.5.6/src/lib.rs

@@ -0,0 +1,14 @@
+//@ ignore-auxiliary (used by `../../../pretty-print-hack/hide.rs`)
+
+#[derive(Print)]
+enum ProceduralMasqueradeDummyType {
+//~^ ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+//~| ERROR using
+//~| WARN this was previously
+    Input
+}

tests/ui/resolve/exported-macro-in-mod-147958.rs

@@ -1,21 +0,0 @@
-//! Regression test for <https://github.com/rust-lang/rust/issues/147958>
-
-//@ check-pass
-
-#![feature(decl_macro)]
-
-macro_rules! exported {
-    () => {
-        #[macro_export]
-        macro_rules! exported {
-            () => {};
-        }
-    };
-}
-use inner1::*;
-exported!();
-mod inner1 {
-    pub macro exported() {}
-}
-
-fn main() {}

tests/ui/test-attrs/issue-109816.rs

@@ -1,5 +1,4 @@
 //@ compile-flags: --test
-//@ reference: attributes.testing.test.allowed-positions
 
 fn align_offset_weird_strides() {
     #[test]

tests/ui/test-attrs/issue-109816.stderr

@@ -1,5 +1,5 @@
 error: the `#[test]` attribute may only be used on a free function
-  --> $DIR/issue-109816.rs:5:5
+  --> $DIR/issue-109816.rs:4:5
    |
 LL |     #[test]
    |     ^^^^^^^ the `#[test]` macro causes a function to be run as a test and has no effect on non-functions

tests/ui/test-attrs/test-attr-non-associated-functions.rs

@@ -1,5 +1,4 @@
 //@ compile-flags:--test
-//@ reference: attributes.testing.test.allowed-positions
 
 struct A {}