Merge pull request #4044 from RalfJung/rustup

Rustup

228 files changed, 3528 insertions, 1540 deletions

diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs
index a09aa9ee665..811cb0be9f9 100644
--- a/compiler/rustc_ast/src/mut_visit.rs
+++ b/compiler/rustc_ast/src/mut_visit.rs
@@ -330,6 +330,10 @@ pub trait MutVisitor: Sized {
     fn visit_capture_by(&mut self, capture_by: &mut CaptureBy) {
         walk_capture_by(self, capture_by)
     }
+
+    fn visit_fn_ret_ty(&mut self, fn_ret_ty: &mut FnRetTy) {
+        walk_fn_ret_ty(self, fn_ret_ty)
+    }
 }
 
 /// Use a map-style function (`FnOnce(T) -> T`) to overwrite a `&mut T`. Useful
@@ -609,7 +613,7 @@ fn walk_angle_bracketed_parameter_data<T: MutVisitor>(vis: &mut T, data: &mut An
 fn walk_parenthesized_parameter_data<T: MutVisitor>(vis: &mut T, args: &mut ParenthesizedArgs) {
     let ParenthesizedArgs { inputs, output, span, inputs_span } = args;
     visit_thin_vec(inputs, |input| vis.visit_ty(input));
-    walk_fn_ret_ty(vis, output);
+    vis.visit_fn_ret_ty(output);
     vis.visit_span(span);
     vis.visit_span(inputs_span);
 }
@@ -911,7 +915,7 @@ fn walk_fn<T: MutVisitor>(vis: &mut T, kind: FnKind<'_>) {
 fn walk_fn_decl<T: MutVisitor>(vis: &mut T, decl: &mut P<FnDecl>) {
     let FnDecl { inputs, output } = decl.deref_mut();
     inputs.flat_map_in_place(|param| vis.flat_map_param(param));
-    walk_fn_ret_ty(vis, output);
+    vis.visit_fn_ret_ty(output);
 }
 
 fn walk_fn_ret_ty<T: MutVisitor>(vis: &mut T, fn_ret_ty: &mut FnRetTy) {
diff --git a/compiler/rustc_ast/src/visit.rs b/compiler/rustc_ast/src/visit.rs
index 3500c215376..c121e7711ee 100644
--- a/compiler/rustc_ast/src/visit.rs
+++ b/compiler/rustc_ast/src/visit.rs
@@ -299,6 +299,12 @@ pub trait Visitor<'ast>: Sized {
     fn visit_coroutine_kind(&mut self, _coroutine_kind: &'ast CoroutineKind) -> Self::Result {
         Self::Result::output()
     }
+    fn visit_fn_decl(&mut self, fn_decl: &'ast FnDecl) -> Self::Result {
+        walk_fn_decl(self, fn_decl)
+    }
+    fn visit_qself(&mut self, qs: &'ast Option<P<QSelf>>) -> Self::Result {
+        walk_qself(self, qs)
+    }
 }
 
 pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) -> V::Result {
@@ -434,13 +440,13 @@ impl WalkItemKind for ItemKind {
                 body,
                 from_glob: _,
             }) => {
-                try_visit!(walk_qself(visitor, qself));
+                try_visit!(visitor.visit_qself(qself));
                 try_visit!(visitor.visit_path(path, *id));
                 visit_opt!(visitor, visit_ident, rename);
                 visit_opt!(visitor, visit_block, body);
             }
             ItemKind::DelegationMac(box DelegationMac { qself, prefix, suffixes, body }) => {
-                try_visit!(walk_qself(visitor, qself));
+                try_visit!(visitor.visit_qself(qself));
                 try_visit!(visitor.visit_path(prefix, id));
                 if let Some(suffixes) = suffixes {
                     for (ident, rename) in suffixes {
@@ -518,10 +524,10 @@ pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) -> V::Result {
             let BareFnTy { safety: _, ext: _, generic_params, decl, decl_span: _ } =
                 &**function_declaration;
             walk_list!(visitor, visit_generic_param, generic_params);
-            try_visit!(walk_fn_decl(visitor, decl));
+            try_visit!(visitor.visit_fn_decl(decl));
         }
         TyKind::Path(maybe_qself, path) => {
-            try_visit!(walk_qself(visitor, maybe_qself));
+            try_visit!(visitor.visit_qself(maybe_qself));
             try_visit!(visitor.visit_path(path, *id));
         }
         TyKind::Pat(ty, pat) => {
@@ -652,16 +658,16 @@ pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) -> V::Res
     let Pat { id, kind, span: _, tokens: _ } = pattern;
     match kind {
         PatKind::TupleStruct(opt_qself, path, elems) => {
-            try_visit!(walk_qself(visitor, opt_qself));
+            try_visit!(visitor.visit_qself(opt_qself));
             try_visit!(visitor.visit_path(path, *id));
             walk_list!(visitor, visit_pat, elems);
         }
         PatKind::Path(opt_qself, path) => {
-            try_visit!(walk_qself(visitor, opt_qself));
+            try_visit!(visitor.visit_qself(opt_qself));
             try_visit!(visitor.visit_path(path, *id))
         }
         PatKind::Struct(opt_qself, path, fields, _rest) => {
-            try_visit!(walk_qself(visitor, opt_qself));
+            try_visit!(visitor.visit_qself(opt_qself));
             try_visit!(visitor.visit_path(path, *id));
             walk_list!(visitor, visit_pat_field, fields);
         }
@@ -846,13 +852,13 @@ pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>) -> V::Resu
             // Identifier and visibility are visited as a part of the item.
             try_visit!(visitor.visit_fn_header(header));
             try_visit!(visitor.visit_generics(generics));
-            try_visit!(walk_fn_decl(visitor, decl));
+            try_visit!(visitor.visit_fn_decl(decl));
             visit_opt!(visitor, visit_block, body);
         }
         FnKind::Closure(binder, coroutine_kind, decl, body) => {
             try_visit!(visitor.visit_closure_binder(binder));
             visit_opt!(visitor, visit_coroutine_kind, coroutine_kind.as_ref());
-            try_visit!(walk_fn_decl(visitor, decl));
+            try_visit!(visitor.visit_fn_decl(decl));
             try_visit!(visitor.visit_expr(body));
         }
     }
@@ -902,13 +908,13 @@ impl WalkItemKind for AssocItemKind {
                 body,
                 from_glob: _,
             }) => {
-                try_visit!(walk_qself(visitor, qself));
+                try_visit!(visitor.visit_qself(qself));
                 try_visit!(visitor.visit_path(path, *id));
                 visit_opt!(visitor, visit_ident, rename);
                 visit_opt!(visitor, visit_block, body);
             }
             AssocItemKind::DelegationMac(box DelegationMac { qself, prefix, suffixes, body }) => {
-                try_visit!(walk_qself(visitor, qself));
+                try_visit!(visitor.visit_qself(qself));
                 try_visit!(visitor.visit_path(prefix, id));
                 if let Some(suffixes) = suffixes {
                     for (ident, rename) in suffixes {
@@ -1023,7 +1029,7 @@ pub fn walk_inline_asm_sym<'a, V: Visitor<'a>>(
     visitor: &mut V,
     InlineAsmSym { id, qself, path }: &'a InlineAsmSym,
 ) -> V::Result {
-    try_visit!(walk_qself(visitor, qself));
+    try_visit!(visitor.visit_qself(qself));
     visitor.visit_path(path, *id)
 }
 
@@ -1055,7 +1061,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) -> V
         }
         ExprKind::Struct(se) => {
             let StructExpr { qself, path, fields, rest } = &**se;
-            try_visit!(walk_qself(visitor, qself));
+            try_visit!(visitor.visit_qself(qself));
             try_visit!(visitor.visit_path(path, *id));
             walk_list!(visitor, visit_expr_field, fields);
             match rest {
@@ -1164,7 +1170,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) -> V
         }
         ExprKind::Underscore => {}
         ExprKind::Path(maybe_qself, path) => {
-            try_visit!(walk_qself(visitor, maybe_qself));
+            try_visit!(visitor.visit_qself(maybe_qself));
             try_visit!(visitor.visit_path(path, *id));
         }
         ExprKind::Break(opt_label, opt_expr) => {
diff --git a/compiler/rustc_borrowck/src/dataflow.rs b/compiler/rustc_borrowck/src/dataflow.rs
index 7adc7a8863e..452038bc328 100644
--- a/compiler/rustc_borrowck/src/dataflow.rs
+++ b/compiler/rustc_borrowck/src/dataflow.rs
@@ -641,6 +641,7 @@ impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
             | mir::StatementKind::Coverage(..)
             | mir::StatementKind::Intrinsic(..)
             | mir::StatementKind::ConstEvalCounter
+            | mir::StatementKind::BackwardIncompatibleDropHint { .. }
             | mir::StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 03f7b05d1e3..16a4f699177 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -652,6 +652,8 @@ impl<'a, 'tcx> ResultsVisitor<'a, 'tcx, Borrowck<'a, 'tcx>> for MirBorrowckCtxt<
             | StatementKind::Coverage(..)
             // These do not actually affect borrowck
             | StatementKind::ConstEvalCounter
+            // This do not affect borrowck
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::StorageLive(..) => {}
             StatementKind::StorageDead(local) => {
                 self.access_place(
diff --git a/compiler/rustc_borrowck/src/polonius/loan_invalidations.rs b/compiler/rustc_borrowck/src/polonius/loan_invalidations.rs
index d1b65943199..f646beeecf7 100644
--- a/compiler/rustc_borrowck/src/polonius/loan_invalidations.rs
+++ b/compiler/rustc_borrowck/src/polonius/loan_invalidations.rs
@@ -88,6 +88,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LoanInvalidationsGenerator<'a, 'tcx> {
             | StatementKind::Nop
             | StatementKind::Retag { .. }
             | StatementKind::Deinit(..)
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::SetDiscriminant { .. } => {
                 bug!("Statement not allowed in this MIR phase")
             }
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 58a23b9e558..3a7ed711f68 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -1252,6 +1252,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             | StatementKind::Coverage(..)
             | StatementKind::ConstEvalCounter
             | StatementKind::PlaceMention(..)
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => {}
             StatementKind::Deinit(..) | StatementKind::SetDiscriminant { .. } => {
                 bug!("Statement not allowed in this MIR phase")
@@ -1727,7 +1728,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         // `Sized` bound in no way depends on precise regions, so this
         // shouldn't affect `is_sized`.
         let erased_ty = tcx.erase_regions(ty);
-        if !erased_ty.is_sized(tcx, self.infcx.param_env) {
+        // FIXME(#132279): Using `Ty::is_sized` causes us to incorrectly handle opaques here.
+        if !erased_ty.is_sized(tcx, self.infcx.typing_env(self.infcx.param_env)) {
             // in current MIR construction, all non-control-flow rvalue
             // expressions evaluate through `as_temp` or `into` a return
             // slot or local, so to find all unsized rvalues it is enough
diff --git a/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh b/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh
index 2f13b0b9cb8..5b3f2a91207 100644
--- a/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh
+++ b/compiler/rustc_codegen_cranelift/scripts/setup_rust_fork.sh
@@ -38,6 +38,11 @@ local-rebuild = true
 codegen-backends = ["cranelift"]
 deny-warnings = false
 verbose-tests = false
+# The cg_clif sysroot doesn't contain llvm tools and unless llvm_tools is
+# disabled bootstrap will crash trying to copy llvm tools for the bootstrap
+# compiler.
+llvm_tools = false
+
 EOF
 popd
 
diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs
index 1b91d251bfd..70b7d92ce15 100644
--- a/compiler/rustc_codegen_cranelift/src/base.rs
+++ b/compiler/rustc_codegen_cranelift/src/base.rs
@@ -11,7 +11,7 @@ use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir::InlineAsmMacro;
 use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::adjustment::PointerCoercion;
-use rustc_middle::ty::layout::FnAbiOf;
+use rustc_middle::ty::layout::{FnAbiOf, HasTypingEnv};
 use rustc_middle::ty::print::with_no_trimmed_paths;
 
 use crate::constant::ConstantCx;
@@ -841,7 +841,7 @@ fn codegen_stmt<'tcx>(
                     lval.write_cvalue(fx, CValue::by_val(operand, box_layout));
                 }
                 Rvalue::NullaryOp(ref null_op, ty) => {
-                    assert!(lval.layout().ty.is_sized(fx.tcx, ty::ParamEnv::reveal_all()));
+                    assert!(lval.layout().ty.is_sized(fx.tcx, fx.typing_env()));
                     let layout = fx.layout_of(fx.monomorphize(ty));
                     let val = match null_op {
                         NullOp::SizeOf => layout.size.bytes(),
@@ -924,6 +924,7 @@ fn codegen_stmt<'tcx>(
         | StatementKind::FakeRead(..)
         | StatementKind::Retag { .. }
         | StatementKind::PlaceMention(..)
+        | StatementKind::BackwardIncompatibleDropHint { .. }
         | StatementKind::AscribeUserType(..) => {}
 
         StatementKind::Coverage { .. } => unreachable!(),
diff --git a/compiler/rustc_codegen_cranelift/src/common.rs b/compiler/rustc_codegen_cranelift/src/common.rs
index add081bc795..c663fa32965 100644
--- a/compiler/rustc_codegen_cranelift/src/common.rs
+++ b/compiler/rustc_codegen_cranelift/src/common.rs
@@ -103,7 +103,7 @@ fn clif_pair_type_from_ty<'tcx>(
 
 /// Is a pointer to this type a wide ptr?
 pub(crate) fn has_ptr_meta<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool {
-    if ty.is_sized(tcx, ty::ParamEnv::reveal_all()) {
+    if ty.is_sized(tcx, ty::TypingEnv::fully_monomorphized()) {
         return false;
     }
 
diff --git a/compiler/rustc_codegen_cranelift/src/constant.rs b/compiler/rustc_codegen_cranelift/src/constant.rs
index 5311547309c..abe6085b04f 100644
--- a/compiler/rustc_codegen_cranelift/src/constant.rs
+++ b/compiler/rustc_codegen_cranelift/src/constant.rs
@@ -583,6 +583,7 @@ pub(crate) fn mir_operand_get_const_val<'tcx>(
                         | StatementKind::PlaceMention(..)
                         | StatementKind::Coverage(_)
                         | StatementKind::ConstEvalCounter
+                        | StatementKind::BackwardIncompatibleDropHint { .. }
                         | StatementKind::Nop => {}
                     }
                 }
diff --git a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
index c663f6fc2d3..3318c0797ec 100644
--- a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
@@ -744,7 +744,11 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let const_val = fx
                 .tcx
-                .const_eval_instance(ty::ParamEnv::reveal_all(), instance, source_info.span)
+                .const_eval_instance(
+                    ty::TypingEnv::fully_monomorphized(),
+                    instance,
+                    source_info.span,
+                )
                 .unwrap();
             let val = crate::constant::codegen_const_value(fx, const_val, ret.layout().ty);
             ret.write_cvalue(fx, val);
diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs
index 4f3664a503d..6ee599c9964 100644
--- a/compiler/rustc_codegen_ssa/src/back/linker.rs
+++ b/compiler/rustc_codegen_ssa/src/back/linker.rs
@@ -1279,7 +1279,7 @@ impl<'a> WasmLd<'a> {
         let mut wasm_ld = WasmLd { cmd, sess };
         if sess.target_features.contains(&sym::atomics) {
             wasm_ld.link_args(&["--shared-memory", "--max-memory=1073741824", "--import-memory"]);
-            if sess.target.os == "unknown" {
+            if sess.target.os == "unknown" || sess.target.os == "none" {
                 wasm_ld.link_args(&[
                     "--export=__wasm_init_tls",
                     "--export=__tls_size",
@@ -1403,7 +1403,7 @@ impl<'a> Linker for WasmLd<'a> {
         // symbols explicitly passed via the `--export` flags above and hides all
         // others. Various bits and pieces of wasm32-unknown-unknown tooling use
         // this, so be sure these symbols make their way out of the linker as well.
-        if self.sess.target.os == "unknown" {
+        if self.sess.target.os == "unknown" || self.sess.target.os == "none" {
             self.link_args(&["--export=__heap_base", "--export=__data_end"]);
         }
     }
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index c8b3b30218a..27c9cb0b31e 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -22,7 +22,7 @@ use rustc_middle::mir::BinOp;
 use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::layout::{HasTyCtxt, HasTypingEnv, LayoutOf, TyAndLayout};
-use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypingMode};
+use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_session::Session;
 use rustc_session::config::{self, CrateType, EntryFnType, OptLevel, OutputType};
 use rustc_span::symbol::sym;
@@ -119,7 +119,8 @@ pub fn validate_trivial_unsize<'tcx>(
 ) -> bool {
     match (source_data.principal(), target_data.principal()) {
         (Some(hr_source_principal), Some(hr_target_principal)) => {
-            let infcx = tcx.infer_ctxt().build(TypingMode::PostAnalysis);
+            let (infcx, param_env) =
+                tcx.infer_ctxt().build_with_typing_env(ty::TypingEnv::fully_monomorphized());
             let universe = infcx.universe();
             let ocx = ObligationCtxt::new(&infcx);
             infcx.enter_forall(hr_target_principal, |target_principal| {
@@ -130,7 +131,7 @@ pub fn validate_trivial_unsize<'tcx>(
                 );
                 let Ok(()) = ocx.eq_trace(
                     &ObligationCause::dummy(),
-                    ty::ParamEnv::reveal_all(),
+                    param_env,
                     ToTrace::to_trace(
                         &ObligationCause::dummy(),
                         hr_target_principal,
diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
index c35d0b90706..299b98c0a4f 100644
--- a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
@@ -146,10 +146,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             | sym::type_id
             | sym::type_name
             | sym::variant_count => {
-                let value = bx
-                    .tcx()
-                    .const_eval_instance(ty::ParamEnv::reveal_all(), instance, span)
-                    .unwrap();
+                let value = bx.tcx().const_eval_instance(bx.typing_env(), instance, span).unwrap();
                 OperandRef::from_const(bx, value, ret_ty).immediate_or_packed_pair(bx)
             }
             sym::arith_offset => {
diff --git a/compiler/rustc_codegen_ssa/src/mir/statement.rs b/compiler/rustc_codegen_ssa/src/mir/statement.rs
index 1681ea1de5f..cd55a838a75 100644
--- a/compiler/rustc_codegen_ssa/src/mir/statement.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/statement.rs
@@ -92,6 +92,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             | mir::StatementKind::AscribeUserType(..)
             | mir::StatementKind::ConstEvalCounter
             | mir::StatementKind::PlaceMention(..)
+            | mir::StatementKind::BackwardIncompatibleDropHint { .. }
             | mir::StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_codegen_ssa/src/traits/type_.rs b/compiler/rustc_codegen_ssa/src/traits/type_.rs
index 3810c609fd4..6292d321f6b 100644
--- a/compiler/rustc_codegen_ssa/src/traits/type_.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/type_.rs
@@ -78,15 +78,15 @@ pub trait DerivedTypeCodegenMethods<'tcx>:
     }
 
     fn type_is_sized(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_sized(self.tcx(), ty::ParamEnv::reveal_all())
+        ty.is_sized(self.tcx(), self.typing_env())
     }
 
     fn type_is_freeze(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_freeze(self.tcx(), ty::ParamEnv::reveal_all())
+        ty.is_freeze(self.tcx(), self.typing_env())
     }
 
     fn type_has_metadata(&self, ty: Ty<'tcx>) -> bool {
-        if ty.is_sized(self.tcx(), self.param_env()) {
+        if ty.is_sized(self.tcx(), self.typing_env()) {
             return false;
         }
 
diff --git a/compiler/rustc_const_eval/src/check_consts/check.rs b/compiler/rustc_const_eval/src/check_consts/check.rs
index 8e96d365beb..1129b5caec5 100644
--- a/compiler/rustc_const_eval/src/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/check_consts/check.rs
@@ -609,6 +609,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
             | StatementKind::ConstEvalCounter
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_const_eval/src/check_consts/resolver.rs b/compiler/rustc_const_eval/src/check_consts/resolver.rs
index 03624a2ce50..0f9a460ca1b 100644
--- a/compiler/rustc_const_eval/src/check_consts/resolver.rs
+++ b/compiler/rustc_const_eval/src/check_consts/resolver.rs
@@ -120,10 +120,7 @@ where
     ///
     /// [rust-lang/unsafe-code-guidelines#134]: https://github.com/rust-lang/unsafe-code-guidelines/issues/134
     fn shared_borrow_allows_mutation(&self, place: mir::Place<'tcx>) -> bool {
-        !place
-            .ty(self.ccx.body, self.ccx.tcx)
-            .ty
-            .is_freeze(self.ccx.tcx, self.ccx.typing_env.param_env)
+        !place.ty(self.ccx.body, self.ccx.tcx).ty.is_freeze(self.ccx.tcx, self.ccx.typing_env)
     }
 }
 
diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
index ca3ee6773a0..647d880e2bf 100644
--- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
+++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
@@ -7,8 +7,7 @@ use rustc_middle::bug;
 use rustc_middle::mir::interpret::{AllocId, ErrorHandled, InterpErrorInfo};
 use rustc_middle::mir::{self, ConstAlloc, ConstValue};
 use rustc_middle::query::TyCtxtAt;
-use rustc_middle::traits::Reveal;
-use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::layout::{HasTypingEnv, LayoutOf};
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::def_id::LocalDefId;
@@ -31,7 +30,6 @@ fn eval_body_using_ecx<'tcx, R: InterpretationResult<'tcx>>(
     cid: GlobalId<'tcx>,
     body: &'tcx mir::Body<'tcx>,
 ) -> InterpResult<'tcx, R> {
-    trace!(?ecx.param_env);
     let tcx = *ecx.tcx;
     assert!(
         cid.promoted.is_some()
@@ -126,14 +124,14 @@ fn eval_body_using_ecx<'tcx, R: InterpretationResult<'tcx>>(
 pub(crate) fn mk_eval_cx_to_read_const_val<'tcx>(
     tcx: TyCtxt<'tcx>,
     root_span: Span,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     can_access_mut_global: CanAccessMutGlobal,
 ) -> CompileTimeInterpCx<'tcx> {
-    debug!("mk_eval_cx: {:?}", param_env);
+    debug!("mk_eval_cx: {:?}", typing_env);
     InterpCx::new(
         tcx,
         root_span,
-        param_env,
+        typing_env,
         CompileTimeMachine::new(can_access_mut_global, CheckAlignment::No),
     )
 }
@@ -142,11 +140,11 @@ pub(crate) fn mk_eval_cx_to_read_const_val<'tcx>(
 /// Returns both the context and an `OpTy` that represents the constant.
 pub fn mk_eval_cx_for_const_val<'tcx>(
     tcx: TyCtxtAt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     val: mir::ConstValue<'tcx>,
     ty: Ty<'tcx>,
 ) -> Option<(CompileTimeInterpCx<'tcx>, OpTy<'tcx>)> {
-    let ecx = mk_eval_cx_to_read_const_val(tcx.tcx, tcx.span, param_env, CanAccessMutGlobal::No);
+    let ecx = mk_eval_cx_to_read_const_val(tcx.tcx, tcx.span, typing_env, CanAccessMutGlobal::No);
     // FIXME: is it a problem to discard the error here?
     let op = ecx.const_val_to_op(val, ty, None).discard_err()?;
     Some((ecx, op))
@@ -245,7 +243,7 @@ pub(super) fn op_to_const<'tcx>(
 pub(crate) fn turn_into_const_value<'tcx>(
     tcx: TyCtxt<'tcx>,
     constant: ConstAlloc<'tcx>,
-    key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>,
+    key: ty::PseudoCanonicalInput<'tcx, GlobalId<'tcx>>,
 ) -> ConstValue<'tcx> {
     let cid = key.value;
     let def_id = cid.instance.def.def_id();
@@ -254,7 +252,7 @@ pub(crate) fn turn_into_const_value<'tcx>(
     let ecx = mk_eval_cx_to_read_const_val(
         tcx,
         tcx.def_span(key.value.instance.def_id()),
-        key.param_env,
+        key.typing_env,
         CanAccessMutGlobal::from(is_static),
     );
 
@@ -274,23 +272,16 @@ pub(crate) fn turn_into_const_value<'tcx>(
 #[instrument(skip(tcx), level = "debug")]
 pub fn eval_to_const_value_raw_provider<'tcx>(
     tcx: TyCtxt<'tcx>,
-    key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>,
+    key: ty::PseudoCanonicalInput<'tcx, GlobalId<'tcx>>,
 ) -> ::rustc_middle::mir::interpret::EvalToConstValueResult<'tcx> {
-    // Const eval always happens in Reveal::All mode in order to be able to use the hidden types of
-    // opaque types. This is needed for trivial things like `size_of`, but also for using associated
-    // types that are not specified in the opaque type.
-    assert_eq!(key.param_env.reveal(), Reveal::All);
-    let typing_env =
-        ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env: key.param_env };
-
     // We call `const_eval` for zero arg intrinsics, too, in order to cache their value.
     // Catch such calls and evaluate them instead of trying to load a constant's MIR.
     if let ty::InstanceKind::Intrinsic(def_id) = key.value.instance.def {
-        let ty = key.value.instance.ty(tcx, typing_env);
+        let ty = key.value.instance.ty(tcx, key.typing_env);
         let ty::FnDef(_, args) = ty.kind() else {
             bug!("intrinsic with type {:?}", ty);
         };
-        return eval_nullary_intrinsic(tcx, key.param_env, def_id, args).report_err().map_err(
+        return eval_nullary_intrinsic(tcx, key.typing_env, def_id, args).report_err().map_err(
             |error| {
                 let span = tcx.def_span(def_id);
 
@@ -317,7 +308,7 @@ pub fn eval_static_initializer_provider<'tcx>(
 
     let instance = ty::Instance::mono(tcx, def_id.to_def_id());
     let cid = rustc_middle::mir::interpret::GlobalId { instance, promoted: None };
-    eval_in_interpreter(tcx, cid, ty::ParamEnv::reveal_all())
+    eval_in_interpreter(tcx, cid, ty::TypingEnv::fully_monomorphized())
 }
 
 pub trait InterpretationResult<'tcx> {
@@ -342,16 +333,14 @@ impl<'tcx> InterpretationResult<'tcx> for ConstAlloc<'tcx> {
 #[instrument(skip(tcx), level = "debug")]
 pub fn eval_to_allocation_raw_provider<'tcx>(
     tcx: TyCtxt<'tcx>,
-    key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>,
+    key: ty::PseudoCanonicalInput<'tcx, GlobalId<'tcx>>,
 ) -> ::rustc_middle::mir::interpret::EvalToAllocationRawResult<'tcx> {
     // This shouldn't be used for statics, since statics are conceptually places,
     // not values -- so what we do here could break pointer identity.
     assert!(key.value.promoted.is_some() || !tcx.is_static(key.value.instance.def_id()));
-    // Const eval always happens in Reveal::All mode in order to be able to use the hidden types of
-    // opaque types. This is needed for trivial things like `size_of`, but also for using associated
-    // types that are not specified in the opaque type.
-
-    assert_eq!(key.param_env.reveal(), Reveal::All);
+    // Const eval always happens in PostAnalysis mode . See the comment in
+    // `InterpCx::new` for more details.
+    debug_assert_eq!(key.typing_env.typing_mode, ty::TypingMode::PostAnalysis);
     if cfg!(debug_assertions) {
         // Make sure we format the instance even if we do not print it.
         // This serves as a regression test against an ICE on printing.
@@ -362,13 +351,13 @@ pub fn eval_to_allocation_raw_provider<'tcx>(
         trace!("const eval: {:?} ({})", key, instance);
     }
 
-    eval_in_interpreter(tcx, key.value, key.param_env)
+    eval_in_interpreter(tcx, key.value, key.typing_env)
 }
 
 fn eval_in_interpreter<'tcx, R: InterpretationResult<'tcx>>(
     tcx: TyCtxt<'tcx>,
     cid: GlobalId<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
 ) -> Result<R, ErrorHandled> {
     let def = cid.instance.def.def_id();
     let is_static = tcx.is_static(def);
@@ -376,7 +365,7 @@ fn eval_in_interpreter<'tcx, R: InterpretationResult<'tcx>>(
     let mut ecx = InterpCx::new(
         tcx,
         tcx.def_span(def),
-        param_env,
+        typing_env,
         // Statics (and promoteds inside statics) may access mutable global memory, because unlike consts
         // they do not have to behave "as if" they were evaluated at runtime.
         // For consts however we want to ensure they behave "as if" they were evaluated at runtime,
diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs
index 19c3195aaa4..b27e3606f38 100644
--- a/compiler/rustc_const_eval/src/const_eval/machine.rs
+++ b/compiler/rustc_const_eval/src/const_eval/machine.rs
@@ -9,7 +9,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::{self as hir, CRATE_HIR_ID, LangItem};
 use rustc_middle::mir::AssertMessage;
 use rustc_middle::query::TyCtxtAt;
-use rustc_middle::ty::layout::TyAndLayout;
+use rustc_middle::ty::layout::{HasTypingEnv, TyAndLayout};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::{bug, mir};
 use rustc_span::Span;
@@ -667,7 +667,7 @@ impl<'tcx> interpret::Machine<'tcx> for CompileTimeMachine<'tcx> {
                 .is_some_and(|p| !p.immutable())
         {
             // That next check is expensive, that's why we have all the guards above.
-            let is_immutable = ty.is_freeze(*ecx.tcx, ecx.param_env);
+            let is_immutable = ty.is_freeze(*ecx.tcx, ecx.typing_env());
             let place = ecx.ref_to_mplace(val)?;
             let new_place = if is_immutable {
                 place.map_provenance(CtfeProvenance::as_immutable)
diff --git a/compiler/rustc_const_eval/src/const_eval/mod.rs b/compiler/rustc_const_eval/src/const_eval/mod.rs
index d5012236c34..8cbdcd68e13 100644
--- a/compiler/rustc_const_eval/src/const_eval/mod.rs
+++ b/compiler/rustc_const_eval/src/const_eval/mod.rs
@@ -38,8 +38,8 @@ pub(crate) fn try_destructure_mir_constant_for_user_output<'tcx>(
     val: mir::ConstValue<'tcx>,
     ty: Ty<'tcx>,
 ) -> Option<mir::DestructuredConstant<'tcx>> {
-    let param_env = ty::ParamEnv::reveal_all();
-    let (ecx, op) = mk_eval_cx_for_const_val(tcx, param_env, val, ty)?;
+    let typing_env = ty::TypingEnv::fully_monomorphized();
+    let (ecx, op) = mk_eval_cx_for_const_val(tcx, typing_env, val, ty)?;
 
     // We go to `usize` as we cannot allocate anything bigger anyway.
     let (field_count, variant, down) = match ty.kind() {
@@ -76,10 +76,12 @@ pub fn tag_for_variant_provider<'tcx>(
 ) -> Option<ty::ScalarInt> {
     assert!(ty.is_enum());
 
+    // FIXME: This uses an empty `TypingEnv` even though
+    // it may be used by a generic CTFE.
     let ecx = InterpCx::new(
         tcx,
         ty.default_span(tcx),
-        ty::ParamEnv::reveal_all(),
+        ty::TypingEnv::fully_monomorphized(),
         crate::const_eval::DummyMachine,
     );
 
diff --git a/compiler/rustc_const_eval/src/const_eval/valtrees.rs b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
index 64bedea3b3f..515028e6826 100644
--- a/compiler/rustc_const_eval/src/const_eval/valtrees.rs
+++ b/compiler/rustc_const_eval/src/const_eval/valtrees.rs
@@ -2,7 +2,6 @@ use rustc_abi::{BackendRepr, VariantIdx};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_middle::mir::interpret::{EvalToValTreeResult, GlobalId};
 use rustc_middle::ty::layout::{LayoutCx, LayoutOf, TyAndLayout};
-use rustc_middle::ty::solve::Reveal;
 use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt};
 use rustc_middle::{bug, mir};
 use rustc_span::DUMMY_SP;
@@ -229,16 +228,19 @@ fn create_valtree_place<'tcx>(
 /// Evaluates a constant and turns it into a type-level constant value.
 pub(crate) fn eval_to_valtree<'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     cid: GlobalId<'tcx>,
 ) -> EvalToValTreeResult<'tcx> {
-    let const_alloc = tcx.eval_to_allocation_raw(param_env.and(cid))?;
+    // Const eval always happens in PostAnalysis mode . See the comment in
+    // `InterpCx::new` for more details.
+    debug_assert_eq!(typing_env.typing_mode, ty::TypingMode::PostAnalysis);
+    let const_alloc = tcx.eval_to_allocation_raw(typing_env.as_query_input(cid))?;
 
     // FIXME Need to provide a span to `eval_to_valtree`
     let ecx = mk_eval_cx_to_read_const_val(
         tcx,
         DUMMY_SP,
-        param_env,
+        typing_env,
         // It is absolutely crucial for soundness that
         // we do not read from mutable memory.
         CanAccessMutGlobal::No,
@@ -273,7 +275,8 @@ pub(crate) fn eval_to_valtree<'tcx>(
 #[instrument(skip(tcx), level = "debug", ret)]
 pub fn valtree_to_const_value<'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env_ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>,
+    typing_env: ty::TypingEnv<'tcx>,
+    ty: Ty<'tcx>,
     valtree: ty::ValTree<'tcx>,
 ) -> mir::ConstValue<'tcx> {
     // Basic idea: We directly construct `Scalar` values from trivial `ValTree`s
@@ -282,10 +285,6 @@ pub fn valtree_to_const_value<'tcx>(
     // the `ValTree` and using `place_projection` and `place_field` to
     // create inner `MPlace`s which are filled recursively.
     // FIXME Does this need an example?
-    let (param_env, ty) = param_env_ty.into_parts();
-    debug_assert_eq!(param_env.reveal(), Reveal::All);
-    let typing_env = ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env };
-
     match *ty.kind() {
         ty::FnDef(..) => {
             assert!(valtree.unwrap_branch().is_empty());
@@ -299,10 +298,10 @@ pub fn valtree_to_const_value<'tcx>(
                 ),
             }
         }
-        ty::Pat(ty, _) => valtree_to_const_value(tcx, param_env.and(ty), valtree),
+        ty::Pat(ty, _) => valtree_to_const_value(tcx, typing_env, ty, valtree),
         ty::Ref(_, inner_ty, _) => {
             let mut ecx =
-                mk_eval_cx_to_read_const_val(tcx, DUMMY_SP, param_env, CanAccessMutGlobal::No);
+                mk_eval_cx_to_read_const_val(tcx, DUMMY_SP, typing_env, CanAccessMutGlobal::No);
             let imm = valtree_to_ref(&mut ecx, valtree, inner_ty);
             let imm =
                 ImmTy::from_immediate(imm, tcx.layout_of(typing_env.as_query_input(ty)).unwrap());
@@ -324,14 +323,14 @@ pub fn valtree_to_const_value<'tcx>(
                 for (i, &inner_valtree) in branches.iter().enumerate() {
                     let field = layout.field(&LayoutCx::new(tcx, typing_env), i);
                     if !field.is_zst() {
-                        return valtree_to_const_value(tcx, param_env.and(field.ty), inner_valtree);
+                        return valtree_to_const_value(tcx, typing_env, field.ty, inner_valtree);
                     }
                 }
                 bug!("could not find non-ZST field during in {layout:#?}");
             }
 
             let mut ecx =
-                mk_eval_cx_to_read_const_val(tcx, DUMMY_SP, param_env, CanAccessMutGlobal::No);
+                mk_eval_cx_to_read_const_val(tcx, DUMMY_SP, typing_env, CanAccessMutGlobal::No);
 
             // Need to create a place for this valtree.
             let place = create_valtree_place(&mut ecx, layout, valtree);
diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs
index 6cfe4b21907..ed4a1a9e647 100644
--- a/compiler/rustc_const_eval/src/interpret/call.rs
+++ b/compiler/rustc_const_eval/src/interpret/call.rs
@@ -215,7 +215,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 // Even if `ty` is normalized, the search for the unsized tail will project
                 // to fields, which can yield non-normalized types. So we need to provide a
                 // normalization function.
-                let normalize = |ty| self.tcx.normalize_erasing_regions(self.typing_env(), ty);
+                let normalize = |ty| self.tcx.normalize_erasing_regions(self.typing_env, ty);
                 ty.ptr_metadata_ty(*self.tcx, normalize)
             };
             return interp_ok(meta_ty(caller) == meta_ty(callee));
@@ -652,35 +652,35 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 };
 
                 // Obtain the underlying trait we are working on, and the adjusted receiver argument.
-                let (trait_, dyn_ty, adjusted_recv) =
-                    if let ty::Dynamic(data, _, ty::DynStar) = receiver_place.layout.ty.kind() {
-                        let recv = self.unpack_dyn_star(&receiver_place, data)?;
+                let (trait_, dyn_ty, adjusted_recv) = if let ty::Dynamic(data, _, ty::DynStar) =
+                    receiver_place.layout.ty.kind()
+                {
+                    let recv = self.unpack_dyn_star(&receiver_place, data)?;
 
-                        (data.principal(), recv.layout.ty, recv.ptr())
-                    } else {
-                        // Doesn't have to be a `dyn Trait`, but the unsized tail must be `dyn Trait`.
-                        // (For that reason we also cannot use `unpack_dyn_trait`.)
-                        let receiver_tail = self
-                            .tcx
-                            .struct_tail_for_codegen(receiver_place.layout.ty, self.typing_env());
-                        let ty::Dynamic(receiver_trait, _, ty::Dyn) = receiver_tail.kind() else {
-                            span_bug!(
-                                self.cur_span(),
-                                "dynamic call on non-`dyn` type {}",
-                                receiver_tail
-                            )
-                        };
-                        assert!(receiver_place.layout.is_unsized());
-
-                        // Get the required information from the vtable.
-                        let vptr = receiver_place.meta().unwrap_meta().to_pointer(self)?;
-                        let dyn_ty = self.get_ptr_vtable_ty(vptr, Some(receiver_trait))?;
-
-                        // It might be surprising that we use a pointer as the receiver even if this
-                        // is a by-val case; this works because by-val passing of an unsized `dyn
-                        // Trait` to a function is actually desugared to a pointer.
-                        (receiver_trait.principal(), dyn_ty, receiver_place.ptr())
+                    (data.principal(), recv.layout.ty, recv.ptr())
+                } else {
+                    // Doesn't have to be a `dyn Trait`, but the unsized tail must be `dyn Trait`.
+                    // (For that reason we also cannot use `unpack_dyn_trait`.)
+                    let receiver_tail =
+                        self.tcx.struct_tail_for_codegen(receiver_place.layout.ty, self.typing_env);
+                    let ty::Dynamic(receiver_trait, _, ty::Dyn) = receiver_tail.kind() else {
+                        span_bug!(
+                            self.cur_span(),
+                            "dynamic call on non-`dyn` type {}",
+                            receiver_tail
+                        )
                     };
+                    assert!(receiver_place.layout.is_unsized());
+
+                    // Get the required information from the vtable.
+                    let vptr = receiver_place.meta().unwrap_meta().to_pointer(self)?;
+                    let dyn_ty = self.get_ptr_vtable_ty(vptr, Some(receiver_trait))?;
+
+                    // It might be surprising that we use a pointer as the receiver even if this
+                    // is a by-val case; this works because by-val passing of an unsized `dyn
+                    // Trait` to a function is actually desugared to a pointer.
+                    (receiver_trait.principal(), dyn_ty, receiver_place.ptr())
+                };
 
                 // Now determine the actual method to call. Usually we use the easy way of just
                 // looking up the method at index `idx`.
@@ -704,7 +704,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
                     let concrete_method = Instance::expect_resolve_for_vtable(
                         tcx,
-                        self.typing_env(),
+                        self.typing_env,
                         def_id,
                         instance.args.rebase_onto(tcx, trait_def_id, concrete_trait_ref.args),
                         self.cur_span(),
diff --git a/compiler/rustc_const_eval/src/interpret/cast.rs b/compiler/rustc_const_eval/src/interpret/cast.rs
index 2d1bb5c9551..c95e51f0a1f 100644
--- a/compiler/rustc_const_eval/src/interpret/cast.rs
+++ b/compiler/rustc_const_eval/src/interpret/cast.rs
@@ -83,7 +83,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     ty::FnDef(def_id, args) => {
                         let instance = ty::Instance::resolve_for_fn_ptr(
                             *self.tcx,
-                            self.typing_env(),
+                            self.typing_env,
                             def_id,
                             args,
                         )
@@ -384,7 +384,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     ) -> InterpResult<'tcx> {
         // A<Struct> -> A<Trait> conversion
         let (src_pointee_ty, dest_pointee_ty) =
-            self.tcx.struct_lockstep_tails_for_codegen(source_ty, cast_ty, self.typing_env());
+            self.tcx.struct_lockstep_tails_for_codegen(source_ty, cast_ty, self.typing_env);
 
         match (src_pointee_ty.kind(), dest_pointee_ty.kind()) {
             (&ty::Array(_, length), &ty::Slice(_)) => {
diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs
index 4f413c84615..fe93a48c2f2 100644
--- a/compiler/rustc_const_eval/src/interpret/eval_context.rs
+++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs
@@ -1,10 +1,12 @@
+use std::assert_matches::debug_assert_matches;
+
 use either::{Left, Right};
 use rustc_abi::{Align, HasDataLayout, Size, TargetDataLayout};
 use rustc_errors::DiagCtxtHandle;
 use rustc_hir::def_id::DefId;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::infer::at::ToTrace;
-use rustc_infer::traits::{ObligationCause, Reveal};
+use rustc_infer::traits::ObligationCause;
 use rustc_middle::mir::interpret::{ErrorHandled, InvalidMetaKind, ReportedErrorInfo};
 use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::{
@@ -36,8 +38,9 @@ pub struct InterpCx<'tcx, M: Machine<'tcx>> {
     /// we are evaluating (if this is CTFE).
     pub tcx: TyCtxtAt<'tcx>,
 
-    /// Bounds in scope for polymorphic evaluations.
-    pub(crate) param_env: ty::ParamEnv<'tcx>,
+    /// The current context in case we're evaluating in a
+    /// polymorphic context. This always uses `ty::TypingMode::PostAnalysis`.
+    pub(super) typing_env: ty::TypingEnv<'tcx>,
 
     /// The virtual memory system.
     pub memory: Memory<'tcx, M>,
@@ -68,7 +71,7 @@ where
     M: Machine<'tcx>,
 {
     fn typing_env(&self) -> ty::TypingEnv<'tcx> {
-        self.typing_env()
+        self.typing_env
     }
 }
 
@@ -189,25 +192,23 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     pub fn new(
         tcx: TyCtxt<'tcx>,
         root_span: Span,
-        param_env: ty::ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
         machine: M,
     ) -> Self {
+        // Const eval always happens in post analysis mode in order to be able to use the hidden types of
+        // opaque types. This is needed for trivial things like `size_of`, but also for using associated
+        // types that are not specified in the opaque type. We also use MIR bodies whose opaque types have
+        // already been revealed, so we'd be able to at least partially observe the hidden types anyways.
+        debug_assert_matches!(typing_env.typing_mode, ty::TypingMode::PostAnalysis);
         InterpCx {
             machine,
             tcx: tcx.at(root_span),
-            param_env,
+            typing_env,
             memory: Memory::new(),
             recursion_limit: tcx.recursion_limit(),
         }
     }
 
-    /// During CTFE we're always in `PostAnalysis` mode.
-    #[inline(always)]
-    pub fn typing_env(&self) -> ty::TypingEnv<'tcx> {
-        debug_assert_eq!(self.param_env.reveal(), Reveal::All);
-        ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env: self.param_env }
-    }
-
     /// Returns the span of the currently executed statement/terminator.
     /// This is the span typically used for error reporting.
     #[inline(always)]
@@ -250,7 +251,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
     #[inline]
     pub fn type_is_freeze(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_freeze(*self.tcx, self.param_env)
+        ty.is_freeze(*self.tcx, self.typing_env)
     }
 
     pub fn load_mir(
@@ -296,7 +297,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             .instance
             .try_instantiate_mir_and_normalize_erasing_regions(
                 *self.tcx,
-                self.typing_env(),
+                self.typing_env,
                 ty::EarlyBinder::bind(value),
             )
             .map_err(|_| ErrorHandled::TooGeneric(self.cur_span()))
@@ -309,9 +310,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         args: GenericArgsRef<'tcx>,
     ) -> InterpResult<'tcx, ty::Instance<'tcx>> {
         trace!("resolve: {:?}, {:#?}", def, args);
-        trace!("param_env: {:#?}", self.param_env);
+        trace!("typing_env: {:#?}", self.typing_env);
         trace!("args: {:#?}", args);
-        match ty::Instance::try_resolve(*self.tcx, self.typing_env(), def, args) {
+        match ty::Instance::try_resolve(*self.tcx, self.typing_env, def, args) {
             Ok(Some(instance)) => interp_ok(instance),
             Ok(None) => throw_inval!(TooGeneric),
 
@@ -332,7 +333,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             return true;
         }
         // Slow path: spin up an inference context to check if these traits are sufficiently equal.
-        let (infcx, param_env) = self.tcx.infer_ctxt().build_with_typing_env(self.typing_env());
+        let (infcx, param_env) = self.tcx.infer_ctxt().build_with_typing_env(self.typing_env);
         let ocx = ObligationCtxt::new(&infcx);
         let cause = ObligationCause::dummy_with_span(self.cur_span());
         // equate the two trait refs after normalization
@@ -564,10 +565,10 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         let val = if self.tcx.is_static(gid.instance.def_id()) {
             let alloc_id = self.tcx.reserve_and_set_static_alloc(gid.instance.def_id());
 
-            let ty = instance.ty(self.tcx.tcx, self.typing_env());
+            let ty = instance.ty(self.tcx.tcx, self.typing_env);
             mir::ConstAlloc { alloc_id, ty }
         } else {
-            self.ctfe_query(|tcx| tcx.eval_to_allocation_raw(self.param_env.and(gid)))?
+            self.ctfe_query(|tcx| tcx.eval_to_allocation_raw(self.typing_env.as_query_input(gid)))?
         };
         self.raw_const_to_mplace(val)
     }
@@ -579,7 +580,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         layout: Option<TyAndLayout<'tcx>>,
     ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
         M::eval_mir_constant(self, *val, span, layout, |ecx, val, span, layout| {
-            let const_val = val.eval(*ecx.tcx, ecx.typing_env(), span).map_err(|err| {
+            let const_val = val.eval(*ecx.tcx, ecx.typing_env, span).map_err(|err| {
                 if M::ALL_CONSTS_ARE_PRECHECKED {
                     match err {
                         ErrorHandled::TooGeneric(..) => {},
diff --git a/compiler/rustc_const_eval/src/interpret/intern.rs b/compiler/rustc_const_eval/src/interpret/intern.rs
index 7a1b92601a4..0cbb3b157f3 100644
--- a/compiler/rustc_const_eval/src/interpret/intern.rs
+++ b/compiler/rustc_const_eval/src/interpret/intern.rs
@@ -165,7 +165,7 @@ pub fn intern_const_alloc_recursive<'tcx, M: CompileTimeMachine<'tcx, const_eval
         InternKind::Static(Mutability::Not) => {
             (
                 // Outermost allocation is mutable if `!Freeze`.
-                if ret.layout.ty.is_freeze(*ecx.tcx, ecx.param_env) {
+                if ret.layout.ty.is_freeze(*ecx.tcx, ecx.typing_env) {
                     Mutability::Not
                 } else {
                     Mutability::Mut
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
index c8859ab3e88..a79923e8555 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
@@ -34,13 +34,12 @@ pub(crate) fn alloc_type_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> ConstAll
 /// inside an `InterpCx` and instead have their value computed directly from rustc internal info.
 pub(crate) fn eval_nullary_intrinsic<'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     def_id: DefId,
     args: GenericArgsRef<'tcx>,
 ) -> InterpResult<'tcx, ConstValue<'tcx>> {
     let tp_ty = args.type_at(0);
     let name = tcx.item_name(def_id);
-    let typing_env = ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env };
     interp_ok(match name {
         sym::type_name => {
             ensure_monomorphic_enough(tcx, tp_ty)?;
@@ -152,8 +151,8 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     sym::type_name => Ty::new_static_str(self.tcx.tcx),
                     _ => bug!(),
                 };
-                let val =
-                    self.ctfe_query(|tcx| tcx.const_eval_global_id(self.param_env, gid, tcx.span))?;
+                let val = self
+                    .ctfe_query(|tcx| tcx.const_eval_global_id(self.typing_env, gid, tcx.span))?;
                 let val = self.const_val_to_op(val, ty, Some(dest.layout))?;
                 self.copy_op(&val, dest)?;
             }
@@ -358,7 +357,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
                 let should_panic = !self
                     .tcx
-                    .check_validity_requirement((requirement, self.typing_env().as_query_input(ty)))
+                    .check_validity_requirement((requirement, self.typing_env.as_query_input(ty)))
                     .map_err(|_| err_inval!(TooGeneric))?;
 
                 if should_panic {
diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs
index 07566e9fda2..277d293597a 100644
--- a/compiler/rustc_const_eval/src/interpret/memory.rs
+++ b/compiler/rustc_const_eval/src/interpret/memory.rs
@@ -859,8 +859,8 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
         // # Global allocations
         if let Some(global_alloc) = self.tcx.try_get_global_alloc(id) {
-            let (size, align) = global_alloc.size_and_align(*self.tcx, self.typing_env());
-            let mutbl = global_alloc.mutability(*self.tcx, self.param_env);
+            let (size, align) = global_alloc.size_and_align(*self.tcx, self.typing_env);
+            let mutbl = global_alloc.mutability(*self.tcx, self.typing_env);
             let kind = match global_alloc {
                 GlobalAlloc::Static { .. } | GlobalAlloc::Memory { .. } => AllocKind::LiveData,
                 GlobalAlloc::Function { .. } => bug!("We already checked function pointers above"),
diff --git a/compiler/rustc_const_eval/src/interpret/operator.rs b/compiler/rustc_const_eval/src/interpret/operator.rs
index 201f1b5dc62..1fa5dcbd24f 100644
--- a/compiler/rustc_const_eval/src/interpret/operator.rs
+++ b/compiler/rustc_const_eval/src/interpret/operator.rs
@@ -533,7 +533,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             }
             OffsetOf(fields) => {
                 let val =
-                    self.tcx.offset_of_subfield(self.typing_env(), layout, fields.iter()).bytes();
+                    self.tcx.offset_of_subfield(self.typing_env, layout, fields.iter()).bytes();
                 ImmTy::from_uint(val, usize_layout())
             }
             UbChecks => ImmTy::from_bool(M::ub_checks(self)?, *self.tcx),
diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs
index 13fcccca76b..2beec544fad 100644
--- a/compiler/rustc_const_eval/src/interpret/place.rs
+++ b/compiler/rustc_const_eval/src/interpret/place.rs
@@ -540,7 +540,7 @@ where
                 )?;
             if !mir_assign_valid_types(
                 *self.tcx,
-                self.typing_env(),
+                self.typing_env,
                 self.layout_of(normalized_place_ty)?,
                 place.layout,
             ) {
@@ -871,7 +871,7 @@ where
         // We do NOT compare the types for equality, because well-typed code can
         // actually "transmute" `&mut T` to `&T` in an assignment without a cast.
         let layout_compat =
-            mir_assign_valid_types(*self.tcx, self.typing_env(), src.layout(), dest.layout());
+            mir_assign_valid_types(*self.tcx, self.typing_env, src.layout(), dest.layout());
         if !allow_transmute && !layout_compat {
             span_bug!(
                 self.cur_span(),
diff --git a/compiler/rustc_const_eval/src/interpret/stack.rs b/compiler/rustc_const_eval/src/interpret/stack.rs
index 037c1a233ee..8ce11c71b8b 100644
--- a/compiler/rustc_const_eval/src/interpret/stack.rs
+++ b/compiler/rustc_const_eval/src/interpret/stack.rs
@@ -379,7 +379,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         for &const_ in body.required_consts() {
             let c =
                 self.instantiate_from_current_frame_and_normalize_erasing_regions(const_.const_)?;
-            c.eval(*self.tcx, self.typing_env(), const_.span).map_err(|err| {
+            c.eval(*self.tcx, self.typing_env, const_.span).map_err(|err| {
                 err.emit_note(*self.tcx);
                 err
             })?;
@@ -596,7 +596,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             return interp_ok(layout);
         }
 
-        let layout = from_known_layout(self.tcx, self.typing_env(), layout, || {
+        let layout = from_known_layout(self.tcx, self.typing_env, layout, || {
             let local_ty = frame.body.local_decls[local].ty;
             let local_ty =
                 self.instantiate_from_frame_and_normalize_erasing_regions(frame, local_ty)?;
diff --git a/compiler/rustc_const_eval/src/interpret/step.rs b/compiler/rustc_const_eval/src/interpret/step.rs
index d4525243642..b61865be667 100644
--- a/compiler/rustc_const_eval/src/interpret/step.rs
+++ b/compiler/rustc_const_eval/src/interpret/step.rs
@@ -143,6 +143,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             // Defined to do nothing. These are added by optimization passes, to avoid changing the
             // size of MIR constantly.
             Nop => {}
+
+            // Only used for temporary lifetime lints
+            BackwardIncompatibleDropHint { .. } => {}
         }
 
         interp_ok(())
@@ -418,8 +421,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             .collect::<InterpResult<'tcx, Vec<_>>>()?;
 
         let fn_sig_binder = func.layout.ty.fn_sig(*self.tcx);
-        let fn_sig =
-            self.tcx.normalize_erasing_late_bound_regions(self.typing_env(), fn_sig_binder);
+        let fn_sig = self.tcx.normalize_erasing_late_bound_regions(self.typing_env, fn_sig_binder);
         let extra_args = &args[fn_sig.inputs().len()..];
         let extra_args =
             self.tcx.mk_type_list_from_iter(extra_args.iter().map(|arg| arg.layout().ty));
diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 005b430bc8a..273eaf42d87 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -448,7 +448,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
         meta: MemPlaceMeta<M::Provenance>,
         pointee: TyAndLayout<'tcx>,
     ) -> InterpResult<'tcx> {
-        let tail = self.ecx.tcx.struct_tail_for_codegen(pointee.ty, self.ecx.typing_env());
+        let tail = self.ecx.tcx.struct_tail_for_codegen(pointee.ty, self.ecx.typing_env);
         match tail.kind() {
             ty::Dynamic(data, _, ty::Dyn) => {
                 let vtable = meta.unwrap_meta().to_pointer(self.ecx)?;
@@ -568,7 +568,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
                         throw_validation_failure!(self.path, DanglingPtrUseAfterFree { ptr_kind });
                     };
                     let (size, _align) =
-                        global_alloc.size_and_align(*self.ecx.tcx, self.ecx.typing_env());
+                        global_alloc.size_and_align(*self.ecx.tcx, self.ecx.typing_env);
 
                     if let GlobalAlloc::Static(did) = global_alloc {
                         let DefKind::Static { nested, .. } = self.ecx.tcx.def_kind(did) else {
@@ -619,7 +619,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
                         };
                         // Determine what it actually points to.
                         let alloc_actual_mutbl =
-                            global_alloc.mutability(*self.ecx.tcx, self.ecx.param_env);
+                            global_alloc.mutability(*self.ecx.tcx, self.ecx.typing_env);
                         // Mutable pointer to immutable memory is no good.
                         if ptr_expected_mutbl == Mutability::Mut
                             && alloc_actual_mutbl == Mutability::Not
@@ -848,7 +848,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
             if let Some(alloc_id) = mplace.ptr().provenance.and_then(|p| p.get_alloc_id()) {
                 let tcx = *self.ecx.tcx;
                 // Everything must be already interned.
-                let mutbl = tcx.global_alloc(alloc_id).mutability(tcx, self.ecx.param_env);
+                let mutbl = tcx.global_alloc(alloc_id).mutability(tcx, self.ecx.typing_env);
                 if let Some((_, alloc)) = self.ecx.memory.alloc_map.get(alloc_id) {
                     assert_eq!(alloc.mutability, mutbl);
                 }
@@ -955,7 +955,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
     ) -> Cow<'e, RangeSet> {
         assert!(layout.ty.is_union());
         assert!(layout.is_sized(), "there are no unsized unions");
-        let layout_cx = LayoutCx::new(*ecx.tcx, ecx.typing_env());
+        let layout_cx = LayoutCx::new(*ecx.tcx, ecx.typing_env);
         return M::cached_union_data_range(ecx, layout.ty, || {
             let mut out = RangeSet(Vec::new());
             union_data_range_uncached(&layout_cx, layout, Size::ZERO, &mut out);
@@ -1085,7 +1085,8 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValueVisitor<'tcx, M> for ValidityVisitor<'rt,
     ) -> InterpResult<'tcx> {
         // Special check for CTFE validation, preventing `UnsafeCell` inside unions in immutable memory.
         if self.ctfe_mode.is_some_and(|c| !c.allow_immutable_unsafe_cell()) {
-            if !val.layout.is_zst() && !val.layout.ty.is_freeze(*self.ecx.tcx, self.ecx.param_env) {
+            if !val.layout.is_zst() && !val.layout.ty.is_freeze(*self.ecx.tcx, self.ecx.typing_env)
+            {
                 if !self.in_mutable_memory(val) {
                     throw_validation_failure!(self.path, UnsafeCellInImmutable);
                 }
diff --git a/compiler/rustc_const_eval/src/lib.rs b/compiler/rustc_const_eval/src/lib.rs
index 527236b2c22..2a7408f1c70 100644
--- a/compiler/rustc_const_eval/src/lib.rs
+++ b/compiler/rustc_const_eval/src/lib.rs
@@ -40,14 +40,13 @@ pub fn provide(providers: &mut Providers) {
     providers.eval_to_allocation_raw = const_eval::eval_to_allocation_raw_provider;
     providers.eval_static_initializer = const_eval::eval_static_initializer_provider;
     providers.hooks.const_caller_location = util::caller_location::const_caller_location_provider;
-    providers.eval_to_valtree = |tcx, param_env_and_value| {
-        let (param_env, raw) = param_env_and_value.into_parts();
-        const_eval::eval_to_valtree(tcx, param_env, raw)
+    providers.eval_to_valtree = |tcx, ty::PseudoCanonicalInput { typing_env, value }| {
+        const_eval::eval_to_valtree(tcx, typing_env, value)
     };
     providers.hooks.try_destructure_mir_constant_for_user_output =
         const_eval::try_destructure_mir_constant_for_user_output;
     providers.valtree_to_const_val = |tcx, (ty, valtree)| {
-        const_eval::valtree_to_const_value(tcx, ty::ParamEnv::reveal_all().and(ty), valtree)
+        const_eval::valtree_to_const_value(tcx, ty::TypingEnv::fully_monomorphized(), ty, valtree)
     };
     providers.check_validity_requirement = |tcx, (init_kind, param_env_and_ty)| {
         util::check_validity_requirement(tcx, init_kind, param_env_and_ty)
diff --git a/compiler/rustc_const_eval/src/util/caller_location.rs b/compiler/rustc_const_eval/src/util/caller_location.rs
index 7f4c36835e4..9bf16d4fe16 100644
--- a/compiler/rustc_const_eval/src/util/caller_location.rs
+++ b/compiler/rustc_const_eval/src/util/caller_location.rs
@@ -60,7 +60,7 @@ pub(crate) fn const_caller_location_provider(
     let mut ecx = mk_eval_cx_to_read_const_val(
         tcx.tcx,
         tcx.span,
-        ty::ParamEnv::reveal_all(),
+        ty::TypingEnv::fully_monomorphized(),
         CanAccessMutGlobal::No,
     );
 
diff --git a/compiler/rustc_const_eval/src/util/check_validity_requirement.rs b/compiler/rustc_const_eval/src/util/check_validity_requirement.rs
index 1afc910ce8f..651a797e97c 100644
--- a/compiler/rustc_const_eval/src/util/check_validity_requirement.rs
+++ b/compiler/rustc_const_eval/src/util/check_validity_requirement.rs
@@ -49,7 +49,7 @@ fn check_validity_requirement_strict<'tcx>(
 ) -> Result<bool, &'tcx LayoutError<'tcx>> {
     let machine = CompileTimeMachine::new(CanAccessMutGlobal::No, CheckAlignment::Error);
 
-    let mut cx = InterpCx::new(cx.tcx(), rustc_span::DUMMY_SP, cx.typing_env.param_env, machine);
+    let mut cx = InterpCx::new(cx.tcx(), rustc_span::DUMMY_SP, cx.typing_env, machine);
 
     let allocated = cx
         .allocate(ty, MemoryKind::Machine(crate::const_eval::MemoryKind::Heap))
diff --git a/compiler/rustc_data_structures/src/unord.rs b/compiler/rustc_data_structures/src/unord.rs
index bafb16a8b5e..34895d3efe6 100644
--- a/compiler/rustc_data_structures/src/unord.rs
+++ b/compiler/rustc_data_structures/src/unord.rs
@@ -602,6 +602,11 @@ impl<K: Eq + Hash, V> UnordMap<K, V> {
             .into_iter()
             .map(|(_, v)| v)
     }
+
+    #[inline]
+    pub fn clear(&mut self) {
+        self.inner.clear()
+    }
 }
 
 impl<K, Q: ?Sized, V> Index<&Q> for UnordMap<K, V>
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index b6f7abed6f3..8dd043be6ad 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -577,7 +577,7 @@ fn show_md_content_with_pager(content: &str, color: ColorConfig) {
     let mut cmd = Command::new(&pager_name);
     // FIXME: find if other pagers accept color options
     let mut print_formatted = if pager_name == "less" {
-        cmd.arg("-r");
+        cmd.arg("-R");
         true
     } else {
         ["bat", "catbat", "delta"].iter().any(|v| *v == pager_name)
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index ce2b47ed1ea..fd08b35d242 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -880,6 +880,11 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         "lang items are subject to change",
     ),
     rustc_attr!(
+        rustc_as_ptr, Normal, template!(Word), ErrorFollowing,
+        EncodeCrossCrate::Yes,
+        "#[rustc_as_ptr] is used to mark functions returning pointers to their inner allocations."
+    ),
+    rustc_attr!(
         rustc_pass_by_value, Normal, template!(Word), ErrorFollowing,
         EncodeCrossCrate::Yes,
         "#[rustc_pass_by_value] is used to mark types that must be passed by value instead of reference."
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index cf8c81c0b08..aa9d303cacb 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -90,24 +90,24 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
         fn allowed_union_field<'tcx>(
             ty: Ty<'tcx>,
             tcx: TyCtxt<'tcx>,
-            param_env: ty::ParamEnv<'tcx>,
+            typing_env: ty::TypingEnv<'tcx>,
         ) -> bool {
             // We don't just accept all !needs_drop fields, due to semver concerns.
             match ty.kind() {
                 ty::Ref(..) => true, // references never drop (even mutable refs, which are non-Copy and hence fail the later check)
                 ty::Tuple(tys) => {
                     // allow tuples of allowed types
-                    tys.iter().all(|ty| allowed_union_field(ty, tcx, param_env))
+                    tys.iter().all(|ty| allowed_union_field(ty, tcx, typing_env))
                 }
                 ty::Array(elem, _len) => {
                     // Like `Copy`, we do *not* special-case length 0.
-                    allowed_union_field(*elem, tcx, param_env)
+                    allowed_union_field(*elem, tcx, typing_env)
                 }
                 _ => {
                     // Fallback case: allow `ManuallyDrop` and things that are `Copy`,
                     // also no need to report an error if the type is unresolved.
                     ty.ty_adt_def().is_some_and(|adt_def| adt_def.is_manually_drop())
-                        || ty.is_copy_modulo_regions(tcx, param_env)
+                        || ty.is_copy_modulo_regions(tcx, typing_env)
                         || ty.references_error()
                 }
             }
@@ -121,7 +121,7 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
                 continue;
             };
 
-            if !allowed_union_field(field_ty, tcx, typing_env.param_env) {
+            if !allowed_union_field(field_ty, tcx, typing_env) {
                 let (field_span, ty_span) = match tcx.hir().get_if_local(field.did) {
                     // We are currently checking the type this field came from, so it must be local.
                     Some(Node::Field(field)) => (field.span, field.ty.span),
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index 77c324183c3..8a051e34f82 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -1193,9 +1193,9 @@ fn compare_self_type<'tcx>(
             ty::AssocItemContainer::Trait => tcx.types.self_param,
         };
         let self_arg_ty = tcx.fn_sig(method.def_id).instantiate_identity().input(0);
-        let param_env = ty::ParamEnv::reveal_all();
-
-        let infcx = tcx.infer_ctxt().build(TypingMode::non_body_analysis());
+        let (infcx, param_env) = tcx
+            .infer_ctxt()
+            .build_with_typing_env(ty::TypingEnv::non_body_analysis(tcx, method.def_id));
         let self_arg_ty = tcx.liberate_late_bound_regions(method.def_id, self_arg_ty);
         let can_eq_self = |ty| infcx.can_eq(param_env, untransformed_self_ty, ty);
         match ExplicitSelf::determine(self_arg_ty, can_eq_self) {
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
index e95669c9d40..dfddf93a5c2 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
@@ -15,7 +15,7 @@ use rustc_target::asm::{
 
 pub struct InlineAsmCtxt<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     get_operand_ty: Box<dyn Fn(&'tcx hir::Expr<'tcx>) -> Ty<'tcx> + 'a>,
 }
 
@@ -23,24 +23,29 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
     pub fn new_global_asm(tcx: TyCtxt<'tcx>) -> Self {
         InlineAsmCtxt {
             tcx,
-            param_env: ty::ParamEnv::empty(),
+            typing_env: ty::TypingEnv {
+                typing_mode: ty::TypingMode::non_body_analysis(),
+                param_env: ty::ParamEnv::empty(),
+            },
             get_operand_ty: Box::new(|e| bug!("asm operand in global asm: {e:?}")),
         }
     }
 
+    // FIXME(#132279): This likely causes us to incorrectly handle opaque types in their
+    // defining scope.
     pub fn new_in_fn(
         tcx: TyCtxt<'tcx>,
-        param_env: ty::ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
         get_operand_ty: impl Fn(&'tcx hir::Expr<'tcx>) -> Ty<'tcx> + 'a,
     ) -> Self {
-        InlineAsmCtxt { tcx, param_env, get_operand_ty: Box::new(get_operand_ty) }
+        InlineAsmCtxt { tcx, typing_env, get_operand_ty: Box::new(get_operand_ty) }
     }
 
     // FIXME(compiler-errors): This could use `<$ty as Pointee>::Metadata == ()`
     fn is_thin_ptr_ty(&self, ty: Ty<'tcx>) -> bool {
         // Type still may have region variables, but `Sized` does not depend
         // on those, so just erase them before querying.
-        if ty.is_sized(self.tcx, self.param_env) {
+        if ty.is_sized(self.tcx, self.typing_env) {
             return true;
         }
         if let ty::Foreign(..) = ty.kind() {
@@ -171,7 +176,7 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
 
         // Check that the type implements Copy. The only case where this can
         // possibly fail is for SIMD types which don't #[derive(Copy)].
-        if !ty.is_copy_modulo_regions(self.tcx, self.param_env) {
+        if !ty.is_copy_modulo_regions(self.tcx, self.typing_env) {
             let msg = "arguments for inline assembly must be copyable";
             self.tcx
                 .dcx()
diff --git a/compiler/rustc_hir_analysis/src/check/region.rs b/compiler/rustc_hir_analysis/src/check/region.rs
index 679f6ccb816..b9cb48cafdc 100644
--- a/compiler/rustc_hir_analysis/src/check/region.rs
+++ b/compiler/rustc_hir_analysis/src/check/region.rs
@@ -17,6 +17,7 @@ use rustc_index::Idx;
 use rustc_middle::bug;
 use rustc_middle::middle::region::*;
 use rustc_middle::ty::TyCtxt;
+use rustc_session::lint;
 use rustc_span::source_map;
 use tracing::debug;
 
@@ -167,8 +168,23 @@ fn resolve_block<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, blk: &'tcx h
             }
         }
         if let Some(tail_expr) = blk.expr {
-            if blk.span.edition().at_least_rust_2024() {
-                visitor.terminating_scopes.insert(tail_expr.hir_id.local_id);
+            let local_id = tail_expr.hir_id.local_id;
+            let edition = blk.span.edition();
+            if edition.at_least_rust_2024() {
+                visitor.terminating_scopes.insert(local_id);
+            } else if !visitor
+                .tcx
+                .lints_that_dont_need_to_run(())
+                .contains(&lint::LintId::of(lint::builtin::TAIL_EXPR_DROP_ORDER))
+            {
+                // If this temporary scope will be changing once the codebase adopts Rust 2024,
+                // and we are linting about possible semantic changes that would result,
+                // then record this node-id in the field `backwards_incompatible_scope`
+                // for future reference.
+                visitor
+                    .scope_tree
+                    .backwards_incompatible_scope
+                    .insert(local_id, Scope { id: local_id, data: ScopeData::Node });
             }
             visitor.visit_expr(tail_expr);
         }
diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index c2ad61820a7..3b49bc41ffe 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -37,22 +37,19 @@ pub(super) fn check_trait<'tcx>(
 ) -> Result<(), ErrorGuaranteed> {
     let lang_items = tcx.lang_items();
     let checker = Checker { tcx, trait_def_id, impl_def_id, impl_header };
-    let mut res = checker.check(lang_items.drop_trait(), visit_implementation_of_drop);
-    res = res.and(checker.check(lang_items.copy_trait(), visit_implementation_of_copy));
-    res = res.and(checker.check(lang_items.const_param_ty_trait(), |checker| {
+    checker.check(lang_items.drop_trait(), visit_implementation_of_drop)?;
+    checker.check(lang_items.copy_trait(), visit_implementation_of_copy)?;
+    checker.check(lang_items.const_param_ty_trait(), |checker| {
         visit_implementation_of_const_param_ty(checker, LangItem::ConstParamTy)
-    }));
-    res = res.and(checker.check(lang_items.unsized_const_param_ty_trait(), |checker| {
+    })?;
+    checker.check(lang_items.unsized_const_param_ty_trait(), |checker| {
         visit_implementation_of_const_param_ty(checker, LangItem::UnsizedConstParamTy)
-    }));
-
-    res = res.and(
-        checker.check(lang_items.coerce_unsized_trait(), visit_implementation_of_coerce_unsized),
-    );
-    res.and(
-        checker
-            .check(lang_items.dispatch_from_dyn_trait(), visit_implementation_of_dispatch_from_dyn),
-    )
+    })?;
+    checker.check(lang_items.coerce_unsized_trait(), visit_implementation_of_coerce_unsized)?;
+    checker
+        .check(lang_items.dispatch_from_dyn_trait(), visit_implementation_of_dispatch_from_dyn)?;
+    checker.check(lang_items.pointer_like(), visit_implementation_of_pointer_like)?;
+    Ok(())
 }
 
 struct Checker<'tcx> {
@@ -663,3 +660,63 @@ fn infringing_fields_error<'tcx>(
 
     err.emit()
 }
+
+fn visit_implementation_of_pointer_like(checker: &Checker<'_>) -> Result<(), ErrorGuaranteed> {
+    let tcx = checker.tcx;
+    let typing_env = ty::TypingEnv::non_body_analysis(tcx, checker.impl_def_id);
+    let impl_span = tcx.def_span(checker.impl_def_id);
+    let self_ty = tcx.impl_trait_ref(checker.impl_def_id).unwrap().instantiate_identity().self_ty();
+
+    // If an ADT is repr(transparent)...
+    if let ty::Adt(def, args) = *self_ty.kind()
+        && def.repr().transparent()
+    {
+        // FIXME(compiler-errors): This should and could be deduplicated into a query.
+        // Find the nontrivial field.
+        let adt_typing_env = ty::TypingEnv::non_body_analysis(tcx, def.did());
+        let nontrivial_field = def.all_fields().find(|field_def| {
+            let field_ty = tcx.type_of(field_def.did).instantiate_identity();
+            !tcx.layout_of(adt_typing_env.as_query_input(field_ty))
+                .is_ok_and(|layout| layout.layout.is_1zst())
+        });
+
+        if let Some(nontrivial_field) = nontrivial_field {
+            // Check that the nontrivial field implements `PointerLike`.
+            let nontrivial_field = nontrivial_field.ty(tcx, args);
+            let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
+            let ocx = ObligationCtxt::new(&infcx);
+            ocx.register_bound(
+                ObligationCause::misc(impl_span, checker.impl_def_id),
+                param_env,
+                nontrivial_field,
+                tcx.lang_items().pointer_like().unwrap(),
+            );
+            // FIXME(dyn-star): We should regionck this implementation.
+            if ocx.select_all_or_error().is_empty() {
+                return Ok(());
+            }
+        }
+    }
+
+    let is_permitted_primitive = match *self_ty.kind() {
+        ty::Adt(def, _) => def.is_box(),
+        ty::Uint(..) | ty::Int(..) | ty::RawPtr(..) | ty::Ref(..) | ty::FnPtr(..) => true,
+        _ => false,
+    };
+
+    if is_permitted_primitive
+        && let Ok(layout) = tcx.layout_of(typing_env.as_query_input(self_ty))
+        && layout.layout.is_pointer_like(&tcx.data_layout)
+    {
+        return Ok(());
+    }
+
+    Err(tcx
+        .dcx()
+        .struct_span_err(
+            impl_span,
+            "implementation must be applied to type that has the same ABI as a pointer, \
+            or is `repr(transparent)` and whose field is `PointerLike`",
+        )
+        .emit())
+}
diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
index 8a1a887766c..eca85c22a40 100644
--- a/compiler/rustc_hir_analysis/src/coherence/orphan.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -172,7 +172,7 @@ pub(crate) fn orphan_check_impl(
             // impl<T> AutoTrait for T {}
             // impl<T: ?Sized> AutoTrait for T {}
             ty::Param(..) => (
-                if self_ty.is_sized(tcx, tcx.param_env(impl_def_id)) {
+                if self_ty.is_sized(tcx, ty::TypingEnv::non_body_analysis(tcx, impl_def_id)) {
                     LocalImpl::Allow
                 } else {
                     LocalImpl::Disallow { problematic_kind: "generic type" }
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 564e45c677d..0a26b6776bb 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -190,8 +190,8 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
             DefKind::Const if tcx.generics_of(item_def_id).is_empty() => {
                 let instance = ty::Instance::new(item_def_id.into(), ty::GenericArgs::empty());
                 let cid = GlobalId { instance, promoted: None };
-                let param_env = ty::ParamEnv::reveal_all();
-                tcx.ensure().eval_to_const_value_raw(param_env.and(cid));
+                let typing_env = ty::TypingEnv::fully_monomorphized();
+                tcx.ensure().eval_to_const_value_raw(typing_env.as_query_input(cid));
             }
             _ => (),
         }
diff --git a/compiler/rustc_hir_typeck/src/expr_use_visitor.rs b/compiler/rustc_hir_typeck/src/expr_use_visitor.rs
index 59bef8315d8..2a00530c434 100644
--- a/compiler/rustc_hir_typeck/src/expr_use_visitor.rs
+++ b/compiler/rustc_hir_typeck/src/expr_use_visitor.rs
@@ -228,7 +228,7 @@ impl<'tcx> TypeInformationCtxt<'tcx> for (&LateContext<'tcx>, LocalDefId) {
     }
 
     fn type_is_copy_modulo_regions(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_copy_modulo_regions(self.0.tcx, self.0.param_env)
+        ty.is_copy_modulo_regions(self.0.tcx, self.0.typing_env())
     }
 
     fn body_owner_def_id(&self) -> LocalDefId {
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 50d1322eba6..961526831fb 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -105,8 +105,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     self.tcx.erase_regions(ty)
                 }
             };
-            InlineAsmCtxt::new_in_fn(self.tcx, self.param_env, get_operand_ty)
-                .check_asm(asm, enclosing_id);
+            InlineAsmCtxt::new_in_fn(
+                self.tcx,
+                self.infcx.typing_env(self.param_env),
+                get_operand_ty,
+            )
+            .check_asm(asm, enclosing_id);
         }
     }
 
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index 8694800ac43..2f436ce77a4 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -831,8 +831,7 @@ impl<'cx, 'tcx> Resolver<'cx, 'tcx> {
 
         // Normalize consts in writeback, because GCE doesn't normalize eagerly.
         if tcx.features().generic_const_exprs() {
-            value =
-                value.fold_with(&mut EagerlyNormalizeConsts { tcx, param_env: self.fcx.param_env });
+            value = value.fold_with(&mut EagerlyNormalizeConsts::new(self.fcx));
         }
 
         value
@@ -873,16 +872,22 @@ impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for Resolver<'cx, 'tcx> {
 
 struct EagerlyNormalizeConsts<'tcx> {
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
 }
+impl<'tcx> EagerlyNormalizeConsts<'tcx> {
+    fn new(fcx: &FnCtxt<'_, 'tcx>) -> Self {
+        // FIXME(#132279, generic_const_exprs): Using `try_normalize_erasing_regions` here
+        // means we can't handle opaque types in their defining scope.
+        EagerlyNormalizeConsts { tcx: fcx.tcx, typing_env: fcx.typing_env(fcx.param_env) }
+    }
+}
+
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for EagerlyNormalizeConsts<'tcx> {
     fn cx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
     fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
-        self.tcx
-            .try_normalize_erasing_regions(ty::TypingEnv::from_param_env(self.param_env), ct)
-            .unwrap_or(ct)
+        self.tcx.try_normalize_erasing_regions(self.typing_env, ct).unwrap_or(ct)
     }
 }
diff --git a/compiler/rustc_index/src/bit_set.rs b/compiler/rustc_index/src/bit_set.rs
index c2b9cae680b..a9239489222 100644
--- a/compiler/rustc_index/src/bit_set.rs
+++ b/compiler/rustc_index/src/bit_set.rs
@@ -460,6 +460,10 @@ impl<T: Idx> ChunkedBitSet<T> {
         self.chunks.iter().map(|chunk| chunk.count()).sum()
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.chunks.iter().all(|chunk| matches!(chunk, Chunk::Zeros(..) | Chunk::Ones(0)))
+    }
+
     /// Returns `true` if `self` contains `elem`.
     #[inline]
     pub fn contains(&self, elem: T) -> bool {
@@ -668,12 +672,140 @@ impl<T: Idx> BitRelations<ChunkedBitSet<T>> for ChunkedBitSet<T> {
         changed
     }
 
-    fn subtract(&mut self, _other: &ChunkedBitSet<T>) -> bool {
-        unimplemented!("implement if/when necessary");
+    fn subtract(&mut self, other: &ChunkedBitSet<T>) -> bool {
+        assert_eq!(self.domain_size, other.domain_size);
+        debug_assert_eq!(self.chunks.len(), other.chunks.len());
+
+        let mut changed = false;
+        for (mut self_chunk, other_chunk) in self.chunks.iter_mut().zip(other.chunks.iter()) {
+            match (&mut self_chunk, &other_chunk) {
+                (Zeros(..), _) | (_, Zeros(..)) => {}
+                (
+                    Ones(self_chunk_domain_size) | Mixed(self_chunk_domain_size, _, _),
+                    Ones(other_chunk_domain_size),
+                ) => {
+                    debug_assert_eq!(self_chunk_domain_size, other_chunk_domain_size);
+                    changed = true;
+                    *self_chunk = Zeros(*self_chunk_domain_size);
+                }
+                (
+                    Ones(self_chunk_domain_size),
+                    Mixed(other_chunk_domain_size, other_chunk_count, other_chunk_words),
+                ) => {
+                    debug_assert_eq!(self_chunk_domain_size, other_chunk_domain_size);
+                    changed = true;
+                    let num_words = num_words(*self_chunk_domain_size as usize);
+                    debug_assert!(num_words > 0 && num_words <= CHUNK_WORDS);
+                    let mut tail_mask =
+                        1 << (*other_chunk_domain_size - ((num_words - 1) * WORD_BITS) as u16) - 1;
+                    let mut self_chunk_words = **other_chunk_words;
+                    for word in self_chunk_words[0..num_words].iter_mut().rev() {
+                        *word = !*word & tail_mask;
+                        tail_mask = u64::MAX;
+                    }
+                    let self_chunk_count = *self_chunk_domain_size - *other_chunk_count;
+                    debug_assert_eq!(
+                        self_chunk_count,
+                        self_chunk_words[0..num_words]
+                            .iter()
+                            .map(|w| w.count_ones() as ChunkSize)
+                            .sum()
+                    );
+                    *self_chunk =
+                        Mixed(*self_chunk_domain_size, self_chunk_count, Rc::new(self_chunk_words));
+                }
+                (
+                    Mixed(
+                        self_chunk_domain_size,
+                        ref mut self_chunk_count,
+                        ref mut self_chunk_words,
+                    ),
+                    Mixed(_other_chunk_domain_size, _other_chunk_count, other_chunk_words),
+                ) => {
+                    // See [`<Self as BitRelations<ChunkedBitSet<T>>>::union`] for the explanation
+                    let op = |a: u64, b: u64| a & !b;
+                    let num_words = num_words(*self_chunk_domain_size as usize);
+                    if bitwise_changes(
+                        &self_chunk_words[0..num_words],
+                        &other_chunk_words[0..num_words],
+                        op,
+                    ) {
+                        let self_chunk_words = Rc::make_mut(self_chunk_words);
+                        let has_changed = bitwise(
+                            &mut self_chunk_words[0..num_words],
+                            &other_chunk_words[0..num_words],
+                            op,
+                        );
+                        debug_assert!(has_changed);
+                        *self_chunk_count = self_chunk_words[0..num_words]
+                            .iter()
+                            .map(|w| w.count_ones() as ChunkSize)
+                            .sum();
+                        if *self_chunk_count == 0 {
+                            *self_chunk = Zeros(*self_chunk_domain_size);
+                        }
+                        changed = true;
+                    }
+                }
+            }
+        }
+        changed
     }
 
-    fn intersect(&mut self, _other: &ChunkedBitSet<T>) -> bool {
-        unimplemented!("implement if/when necessary");
+    fn intersect(&mut self, other: &ChunkedBitSet<T>) -> bool {
+        assert_eq!(self.domain_size, other.domain_size);
+        debug_assert_eq!(self.chunks.len(), other.chunks.len());
+
+        let mut changed = false;
+        for (mut self_chunk, other_chunk) in self.chunks.iter_mut().zip(other.chunks.iter()) {
+            match (&mut self_chunk, &other_chunk) {
+                (Zeros(..), _) | (_, Ones(..)) => {}
+                (
+                    Ones(self_chunk_domain_size),
+                    Zeros(other_chunk_domain_size) | Mixed(other_chunk_domain_size, ..),
+                )
+                | (Mixed(self_chunk_domain_size, ..), Zeros(other_chunk_domain_size)) => {
+                    debug_assert_eq!(self_chunk_domain_size, other_chunk_domain_size);
+                    changed = true;
+                    *self_chunk = other_chunk.clone();
+                }
+                (
+                    Mixed(
+                        self_chunk_domain_size,
+                        ref mut self_chunk_count,
+                        ref mut self_chunk_words,
+                    ),
+                    Mixed(_other_chunk_domain_size, _other_chunk_count, other_chunk_words),
+                ) => {
+                    // See [`<Self as BitRelations<ChunkedBitSet<T>>>::union`] for the explanation
+                    let op = |a, b| a & b;
+                    let num_words = num_words(*self_chunk_domain_size as usize);
+                    if bitwise_changes(
+                        &self_chunk_words[0..num_words],
+                        &other_chunk_words[0..num_words],
+                        op,
+                    ) {
+                        let self_chunk_words = Rc::make_mut(self_chunk_words);
+                        let has_changed = bitwise(
+                            &mut self_chunk_words[0..num_words],
+                            &other_chunk_words[0..num_words],
+                            op,
+                        );
+                        debug_assert!(has_changed);
+                        *self_chunk_count = self_chunk_words[0..num_words]
+                            .iter()
+                            .map(|w| w.count_ones() as ChunkSize)
+                            .sum();
+                        if *self_chunk_count == 0 {
+                            *self_chunk = Zeros(*self_chunk_domain_size);
+                        }
+                        changed = true;
+                    }
+                }
+            }
+        }
+
+        changed
     }
 }
 
diff --git a/compiler/rustc_lexer/src/lib.rs b/compiler/rustc_lexer/src/lib.rs
index f9f2a14dbd2..bcb103957ba 100644
--- a/compiler/rustc_lexer/src/lib.rs
+++ b/compiler/rustc_lexer/src/lib.rs
@@ -57,11 +57,10 @@ impl Token {
 /// Enum representing common lexeme types.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum TokenKind {
-    // Multi-char tokens:
-    /// "// comment"
+    /// A line comment, e.g. `// comment`.
     LineComment { doc_style: Option<DocStyle> },
 
-    /// `/* block comment */`
+    /// A block comment, e.g. `/* block comment */`.
     ///
     /// Block comments can be recursive, so a sequence like `/* /* */`
     /// will not be considered terminated and will result in a parsing error.
@@ -70,18 +69,17 @@ pub enum TokenKind {
     /// Any whitespace character sequence.
     Whitespace,
 
-    /// "ident" or "continue"
-    ///
-    /// At this step, keywords are also considered identifiers.
+    /// An identifier or keyword, e.g. `ident` or `continue`.
     Ident,
 
-    /// Like the above, but containing invalid unicode codepoints.
+    /// An identifier that is invalid because it contains emoji.
     InvalidIdent,
 
-    /// "r#ident"
+    /// A raw identifier, e.g. "r#ident".
     RawIdent,
 
-    /// An unknown prefix, like `foo#`, `foo'`, `foo"`.
+    /// An unknown literal prefix, like `foo#`, `foo'`, `foo"`. Excludes
+    /// literal prefixes that contain emoji, which are considered "invalid".
     ///
     /// Note that only the
     /// prefix (`foo`) is included in the token, not the separator (which is
@@ -93,87 +91,83 @@ pub enum TokenKind {
 
     /// An unknown prefix in a lifetime, like `'foo#`.
     ///
-    /// Note that like above, only the `'` and prefix are included in the token
+    /// Like `UnknownPrefix`, only the `'` and prefix are included in the token
     /// and not the separator.
     UnknownPrefixLifetime,
 
-    /// `'r#lt`, which in edition < 2021 is split into several tokens: `'r # lt`.
+    /// A raw lifetime, e.g. `'r#foo`. In edition < 2021 it will be split into
+    /// several tokens: `'r` and `#` and `foo`.
     RawLifetime,
 
-    /// Similar to the above, but *always* an error on every edition. This is used
-    /// for emoji identifier recovery, as those are not meant to be ever accepted.
-    InvalidPrefix,
-
     /// Guarded string literal prefix: `#"` or `##`.
     ///
     /// Used for reserving "guarded strings" (RFC 3598) in edition 2024.
     /// Split into the component tokens on older editions.
     GuardedStrPrefix,
 
-    /// Examples: `12u8`, `1.0e-40`, `b"123"`. Note that `_` is an invalid
+    /// Literals, e.g. `12u8`, `1.0e-40`, `b"123"`. Note that `_` is an invalid
     /// suffix, but may be present here on string and float literals. Users of
     /// this type will need to check for and reject that case.
     ///
     /// See [LiteralKind] for more details.
     Literal { kind: LiteralKind, suffix_start: u32 },
 
-    /// "'a"
+    /// A lifetime, e.g. `'a`.
     Lifetime { starts_with_number: bool },
 
-    // One-char tokens:
-    /// ";"
+    /// `;`
     Semi,
-    /// ","
+    /// `,`
     Comma,
-    /// "."
+    /// `.`
     Dot,
-    /// "("
+    /// `(`
     OpenParen,
-    /// ")"
+    /// `)`
     CloseParen,
-    /// "{"
+    /// `{`
     OpenBrace,
-    /// "}"
+    /// `}`
     CloseBrace,
-    /// "["
+    /// `[`
     OpenBracket,
-    /// "]"
+    /// `]`
     CloseBracket,
-    /// "@"
+    /// `@`
     At,
-    /// "#"
+    /// `#`
     Pound,
-    /// "~"
+    /// `~`
     Tilde,
-    /// "?"
+    /// `?`
     Question,
-    /// ":"
+    /// `:`
     Colon,
-    /// "$"
+    /// `$`
     Dollar,
-    /// "="
+    /// `=`
     Eq,
-    /// "!"
+    /// `!`
     Bang,
-    /// "<"
+    /// `<`
     Lt,
-    /// ">"
+    /// `>`
     Gt,
-    /// "-"
+    /// `-`
     Minus,
-    /// "&"
+    /// `&`
     And,
-    /// "|"
+    /// `|`
     Or,
-    /// "+"
+    /// `+`
     Plus,
-    /// "*"
+    /// `*`
     Star,
-    /// "/"
+    /// `/`
     Slash,
-    /// "^"
+    /// `^`
     Caret,
-    /// "%"
+    /// `%`
     Percent,
 
     /// Unknown token, not expected by the lexer, e.g. "№"
@@ -468,7 +462,7 @@ impl Cursor<'_> {
                 Literal { kind, suffix_start }
             }
             // Identifier starting with an emoji. Only lexed for graceful error recovery.
-            c if !c.is_ascii() && c.is_emoji_char() => self.fake_ident_or_unknown_prefix(),
+            c if !c.is_ascii() && c.is_emoji_char() => self.invalid_ident(),
             _ => Unknown,
         };
         let res = Token::new(token_kind, self.pos_within_token());
@@ -552,24 +546,22 @@ impl Cursor<'_> {
         // we see a prefix here, it is definitely an unknown prefix.
         match self.first() {
             '#' | '"' | '\'' => UnknownPrefix,
-            c if !c.is_ascii() && c.is_emoji_char() => self.fake_ident_or_unknown_prefix(),
+            c if !c.is_ascii() && c.is_emoji_char() => self.invalid_ident(),
             _ => Ident,
         }
     }
 
-    fn fake_ident_or_unknown_prefix(&mut self) -> TokenKind {
+    fn invalid_ident(&mut self) -> TokenKind {
         // Start is already eaten, eat the rest of identifier.
         self.eat_while(|c| {
-            unicode_xid::UnicodeXID::is_xid_continue(c)
-                || (!c.is_ascii() && c.is_emoji_char())
-                || c == '\u{200d}'
+            const ZERO_WIDTH_JOINER: char = '\u{200d}';
+            is_id_continue(c) || (!c.is_ascii() && c.is_emoji_char()) || c == ZERO_WIDTH_JOINER
         });
-        // Known prefixes must have been handled earlier. So if
-        // we see a prefix here, it is definitely an unknown prefix.
-        match self.first() {
-            '#' | '"' | '\'' => InvalidPrefix,
-            _ => InvalidIdent,
-        }
+        // An invalid identifier followed by '#' or '"' or '\'' could be
+        // interpreted as an invalid literal prefix. We don't bother doing that
+        // because the treatment of invalid identifiers and invalid prefixes
+        // would be the same.
+        InvalidIdent
     }
 
     fn c_or_byte_string(
diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
index 6e35d89b488..69fd7f2d8b2 100644
--- a/compiler/rustc_lint/messages.ftl
+++ b/compiler/rustc_lint/messages.ftl
@@ -772,9 +772,6 @@ lint_suspicious_double_ref_clone =
 lint_suspicious_double_ref_deref =
     using `.deref()` on a double reference, which returns `{$ty}` instead of dereferencing the inner type
 
-lint_tail_expr_drop_order = these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
-    .label = these values have significant drop implementation and will observe changes in drop order under Edition 2024
-
 lint_trailing_semi_macro = trailing semicolon in macro used in expression position
     .note1 = macro invocations at the end of a block are treated as expressions
     .note2 = to ignore the value produced by the macro, add a semicolon after the invocation of `{$name}`
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index f6366ec3b80..bda982a3675 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -32,7 +32,7 @@ use rustc_middle::bug;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, TypingMode, Upcast, VariantDef};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, Upcast, VariantDef};
 use rustc_session::lint::FutureIncompatibilityReason;
 // hardwired lints from rustc_lint_defs
 pub use rustc_session::lint::builtin::*;
@@ -586,10 +586,10 @@ impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations {
                 return;
             }
         }
-        if ty.is_copy_modulo_regions(cx.tcx, cx.param_env) {
+        if ty.is_copy_modulo_regions(cx.tcx, cx.typing_env()) {
             return;
         }
-        if type_implements_negative_copy_modulo_regions(cx.tcx, ty, cx.param_env) {
+        if type_implements_negative_copy_modulo_regions(cx.tcx, ty, cx.typing_env()) {
             return;
         }
         if def.is_variant_list_non_exhaustive()
@@ -637,8 +637,9 @@ impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations {
 fn type_implements_negative_copy_modulo_regions<'tcx>(
     tcx: TyCtxt<'tcx>,
     ty: Ty<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
 ) -> bool {
+    let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
     let trait_ref = ty::TraitRef::new(tcx, tcx.require_lang_item(hir::LangItem::Copy, None), [ty]);
     let pred = ty::TraitPredicate { trait_ref, polarity: ty::PredicatePolarity::Negative };
     let obligation = traits::Obligation {
@@ -647,10 +648,7 @@ fn type_implements_negative_copy_modulo_regions<'tcx>(
         recursion_depth: 0,
         predicate: pred.upcast(tcx),
     };
-
-    tcx.infer_ctxt()
-        .build(TypingMode::non_body_analysis())
-        .predicate_must_hold_modulo_regions(&obligation)
+    infcx.predicate_must_hold_modulo_regions(&obligation)
 }
 
 declare_lint! {
diff --git a/compiler/rustc_lint/src/dangling.rs b/compiler/rustc_lint/src/dangling.rs
index a34c3e26778..e3e51ba263d 100644
--- a/compiler/rustc_lint/src/dangling.rs
+++ b/compiler/rustc_lint/src/dangling.rs
@@ -43,13 +43,10 @@ declare_lint! {
 }
 
 /// FIXME: false negatives (i.e. the lint is not emitted when it should be)
-/// 1. Method calls that are not checked for:
-///    - [`temporary_unsafe_cell.get()`][`core::cell::UnsafeCell::get()`]
-///    - [`temporary_sync_unsafe_cell.get()`][`core::cell::SyncUnsafeCell::get()`]
-/// 2. Ways to get a temporary that are not recognized:
+/// 1. Ways to get a temporary that are not recognized:
 ///    - `owning_temporary.field`
 ///    - `owning_temporary[index]`
-/// 3. No checks for ref-to-ptr conversions:
+/// 2. No checks for ref-to-ptr conversions:
 ///    - `&raw [mut] temporary`
 ///    - `&temporary as *(const|mut) _`
 ///    - `ptr::from_ref(&temporary)` and friends
@@ -133,10 +130,11 @@ impl DanglingPointerSearcher<'_, '_> {
 
 fn lint_expr(cx: &LateContext<'_>, expr: &Expr<'_>) {
     if let ExprKind::MethodCall(method, receiver, _args, _span) = expr.kind
-        && matches!(method.ident.name, sym::as_ptr | sym::as_mut_ptr)
+        && let Some(fn_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id)
+        && cx.tcx.has_attr(fn_id, sym::rustc_as_ptr)
         && is_temporary_rvalue(receiver)
         && let ty = cx.typeck_results().expr_ty(receiver)
-        && is_interesting(cx.tcx, ty)
+        && owns_allocation(cx.tcx, ty)
     {
         // FIXME: use `emit_node_lint` when `#[primary_span]` is added.
         cx.tcx.emit_node_span_lint(
@@ -199,24 +197,25 @@ fn is_temporary_rvalue(expr: &Expr<'_>) -> bool {
     }
 }
 
-// Array, Vec, String, CString, MaybeUninit, Cell, Box<[_]>, Box<str>, Box<CStr>,
-// or any of the above in arbitrary many nested Box'es.
-fn is_interesting(tcx: TyCtxt<'_>, ty: Ty<'_>) -> bool {
+// Array, Vec, String, CString, MaybeUninit, Cell, Box<[_]>, Box<str>, Box<CStr>, UnsafeCell,
+// SyncUnsafeCell, or any of the above in arbitrary many nested Box'es.
+fn owns_allocation(tcx: TyCtxt<'_>, ty: Ty<'_>) -> bool {
     if ty.is_array() {
         true
     } else if let Some(inner) = ty.boxed_ty() {
         inner.is_slice()
             || inner.is_str()
             || inner.ty_adt_def().is_some_and(|def| tcx.is_lang_item(def.did(), LangItem::CStr))
-            || is_interesting(tcx, inner)
+            || owns_allocation(tcx, inner)
     } else if let Some(def) = ty.ty_adt_def() {
-        for lang_item in [LangItem::String, LangItem::MaybeUninit] {
+        for lang_item in [LangItem::String, LangItem::MaybeUninit, LangItem::UnsafeCell] {
             if tcx.is_lang_item(def.did(), lang_item) {
                 return true;
             }
         }
-        tcx.get_diagnostic_name(def.did())
-            .is_some_and(|name| matches!(name, sym::cstring_type | sym::Vec | sym::Cell))
+        tcx.get_diagnostic_name(def.did()).is_some_and(|name| {
+            matches!(name, sym::cstring_type | sym::Vec | sym::Cell | sym::SyncUnsafeCell)
+        })
     } else {
         false
     }
diff --git a/compiler/rustc_lint/src/drop_forget_useless.rs b/compiler/rustc_lint/src/drop_forget_useless.rs
index 364c6fd488a..8fe86738658 100644
--- a/compiler/rustc_lint/src/drop_forget_useless.rs
+++ b/compiler/rustc_lint/src/drop_forget_useless.rs
@@ -144,7 +144,7 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetUseless {
             && let Some(fn_name) = cx.tcx.get_diagnostic_name(def_id)
         {
             let arg_ty = cx.typeck_results().expr_ty(arg);
-            let is_copy = arg_ty.is_copy_modulo_regions(cx.tcx, cx.param_env);
+            let is_copy = arg_ty.is_copy_modulo_regions(cx.tcx, cx.typing_env());
             let drop_is_single_call_in_arm = is_single_call_in_arm(cx, arg, expr);
             let let_underscore_ignore_sugg = || {
                 if let Some((_, node)) = cx.tcx.hir().parent_iter(expr.hir_id).nth(0)
diff --git a/compiler/rustc_lint/src/impl_trait_overcaptures.rs b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
index beab4d4e6a9..1aacdbd448c 100644
--- a/compiler/rustc_lint/src/impl_trait_overcaptures.rs
+++ b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
@@ -15,7 +15,7 @@ use rustc_middle::ty::relate::{
     Relate, RelateResult, TypeRelation, structurally_relate_consts, structurally_relate_tys,
 };
 use rustc_middle::ty::{
-    self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, TypingMode,
+    self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
 };
 use rustc_middle::{bug, span_bug};
 use rustc_session::lint::FutureIncompatibilityReason;
@@ -186,8 +186,8 @@ fn check_fn(tcx: TyCtxt<'_>, parent_def_id: LocalDefId) {
             functional_variances.variances
         }),
         outlives_env: LazyCell::new(|| {
-            let param_env = tcx.param_env(parent_def_id);
-            let infcx = tcx.infer_ctxt().build(TypingMode::from_param_env(param_env));
+            let typing_env = ty::TypingEnv::non_body_analysis(tcx, parent_def_id);
+            let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
             let ocx = ObligationCtxt::new(&infcx);
             let assumed_wf_tys = ocx.assumed_wf_types(param_env, parent_def_id).unwrap_or_default();
             let implied_bounds =
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 97a95787422..4b1dafbdbee 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -123,17 +123,19 @@ fn lints_that_dont_need_to_run(tcx: TyCtxt<'_>, (): ()) -> FxIndexSet<LintId> {
     let dont_need_to_run: FxIndexSet<LintId> = store
         .get_lints()
         .into_iter()
+        .filter(|lint| {
+            // Lints that show up in future-compat reports must always be run.
+            let has_future_breakage =
+                lint.future_incompatible.is_some_and(|fut| fut.reason.has_future_breakage());
+            !has_future_breakage && !lint.eval_always
+        })
         .filter_map(|lint| {
-            if !lint.eval_always {
-                let lint_level = map.lint_level_id_at_node(tcx, LintId::of(lint), CRATE_HIR_ID);
-                if matches!(lint_level, (Level::Allow, ..))
-                    || (matches!(lint_level, (.., LintLevelSource::Default)))
-                        && lint.default_level(tcx.sess.edition()) == Level::Allow
-                {
-                    Some(LintId::of(lint))
-                } else {
-                    None
-                }
+            let lint_level = map.lint_level_id_at_node(tcx, LintId::of(lint), CRATE_HIR_ID);
+            if matches!(lint_level, (Level::Allow, ..))
+                || (matches!(lint_level, (.., LintLevelSource::Default)))
+                    && lint.default_level(tcx.sess.edition()) == Level::Allow
+            {
+                Some(LintId::of(lint))
             } else {
                 None
             }
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index 86112277504..4cf5c7b4ff9 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -75,7 +75,6 @@ mod redundant_semicolon;
 mod reference_casting;
 mod shadowed_into_iter;
 mod static_mut_refs;
-mod tail_expr_drop_order;
 mod traits;
 mod types;
 mod unit_bindings;
@@ -116,7 +115,6 @@ use rustc_middle::ty::TyCtxt;
 use shadowed_into_iter::ShadowedIntoIter;
 pub use shadowed_into_iter::{ARRAY_INTO_ITER, BOXED_SLICE_INTO_ITER};
 use static_mut_refs::*;
-use tail_expr_drop_order::TailExprDropOrder;
 use traits::*;
 use types::*;
 use unit_bindings::*;
@@ -240,7 +238,6 @@ late_lint_methods!(
             AsyncFnInTrait: AsyncFnInTrait,
             NonLocalDefinitions: NonLocalDefinitions::default(),
             ImplTraitOvercaptures: ImplTraitOvercaptures,
-            TailExprDropOrder: TailExprDropOrder,
             IfLetRescope: IfLetRescope::default(),
             StaticMutRefs: StaticMutRefs,
             UnqualifiedLocalImports: UnqualifiedLocalImports,
diff --git a/compiler/rustc_lint/src/reference_casting.rs b/compiler/rustc_lint/src/reference_casting.rs
index 45d97403d60..7c6656f91c9 100644
--- a/compiler/rustc_lint/src/reference_casting.rs
+++ b/compiler/rustc_lint/src/reference_casting.rs
@@ -168,7 +168,7 @@ fn is_cast_from_ref_to_mut_ptr<'tcx>(
         // Except on the presence of non concrete skeleton types (ie generics)
         // since there is no way to make it safe for arbitrary types.
         let inner_ty_has_interior_mutability =
-            !inner_ty.is_freeze(cx.tcx, cx.param_env) && inner_ty.has_concrete_skeleton();
+            !inner_ty.is_freeze(cx.tcx, cx.typing_env()) && inner_ty.has_concrete_skeleton();
         (!need_check_freeze || !inner_ty_has_interior_mutability)
             .then_some(inner_ty_has_interior_mutability)
     } else {
diff --git a/compiler/rustc_lint/src/tail_expr_drop_order.rs b/compiler/rustc_lint/src/tail_expr_drop_order.rs
deleted file mode 100644
index 19763ce1ec5..00000000000
--- a/compiler/rustc_lint/src/tail_expr_drop_order.rs
+++ /dev/null
@@ -1,308 +0,0 @@
-use std::mem::swap;
-
-use rustc_ast::UnOp;
-use rustc_hir::def::Res;
-use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{self as hir, Block, Expr, ExprKind, LetStmt, Pat, PatKind, QPath, StmtKind};
-use rustc_macros::LintDiagnostic;
-use rustc_middle::ty;
-use rustc_session::lint::FutureIncompatibilityReason;
-use rustc_session::{declare_lint, declare_lint_pass};
-use rustc_span::Span;
-use rustc_span::edition::Edition;
-
-use crate::{LateContext, LateLintPass};
-
-declare_lint! {
-    /// The `tail_expr_drop_order` lint looks for those values generated at the tail expression location,
-    /// that runs a custom `Drop` destructor.
-    /// Some of them may be dropped earlier in Edition 2024 that they used to in Edition 2021 and prior.
-    /// This lint detects those cases and provides you information on those values and their custom destructor implementations.
-    /// Your discretion on this information is required.
-    ///
-    /// ### Example
-    /// ```rust,edition2021
-    /// #![warn(tail_expr_drop_order)]
-    /// struct Droppy(i32);
-    /// impl Droppy {
-    ///     fn get(&self) -> i32 {
-    ///         self.0
-    ///     }
-    /// }
-    /// impl Drop for Droppy {
-    ///     fn drop(&mut self) {
-    ///         // This is a custom destructor and it induces side-effects that is observable
-    ///         // especially when the drop order at a tail expression changes.
-    ///         println!("loud drop {}", self.0);
-    ///     }
-    /// }
-    /// fn edition_2021() -> i32 {
-    ///     let another_droppy = Droppy(0);
-    ///     Droppy(1).get()
-    /// }
-    /// fn main() {
-    ///     edition_2021();
-    /// }
-    /// ```
-    ///
-    /// {{produces}}
-    ///
-    /// ### Explanation
-    ///
-    /// In tail expression of blocks or function bodies,
-    /// values of type with significant `Drop` implementation has an ill-specified drop order
-    /// before Edition 2024 so that they are dropped only after dropping local variables.
-    /// Edition 2024 introduces a new rule with drop orders for them,
-    /// so that they are dropped first before dropping local variables.
-    ///
-    /// A significant `Drop::drop` destructor here refers to an explicit, arbitrary
-    /// implementation of the `Drop` trait on the type, with exceptions including `Vec`,
-    /// `Box`, `Rc`, `BTreeMap` and `HashMap` that are marked by the compiler otherwise
-    /// so long that the generic types have no significant destructor recursively.
-    /// In other words, a type has a significant drop destructor when it has a `Drop` implementation
-    /// or its destructor invokes a significant destructor on a type.
-    /// Since we cannot completely reason about the change by just inspecting the existence of
-    /// a significant destructor, this lint remains only a suggestion and is set to `allow` by default.
-    ///
-    /// This lint only points out the issue with `Droppy`, which will be dropped before `another_droppy`
-    /// does in Edition 2024.
-    /// No fix will be proposed by this lint.
-    /// However, the most probable fix is to hoist `Droppy` into its own local variable binding.
-    /// ```rust
-    /// struct Droppy(i32);
-    /// impl Droppy {
-    ///     fn get(&self) -> i32 {
-    ///         self.0
-    ///     }
-    /// }
-    /// fn edition_2024() -> i32 {
-    ///     let value = Droppy(0);
-    ///     let another_droppy = Droppy(1);
-    ///     value.get()
-    /// }
-    /// ```
-    pub TAIL_EXPR_DROP_ORDER,
-    Allow,
-    "Detect and warn on significant change in drop order in tail expression location",
-    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::EditionSemanticsChange(Edition::Edition2024),
-        reference: "issue #123739 <https://github.com/rust-lang/rust/issues/123739>",
-    };
-}
-
-declare_lint_pass!(TailExprDropOrder => [TAIL_EXPR_DROP_ORDER]);
-
-impl TailExprDropOrder {
-    fn check_fn_or_closure<'tcx>(
-        cx: &LateContext<'tcx>,
-        fn_kind: hir::intravisit::FnKind<'tcx>,
-        body: &'tcx hir::Body<'tcx>,
-        def_id: rustc_span::def_id::LocalDefId,
-    ) {
-        let mut locals = vec![];
-        if matches!(fn_kind, hir::intravisit::FnKind::Closure) {
-            for &capture in cx.tcx.closure_captures(def_id) {
-                if matches!(capture.info.capture_kind, ty::UpvarCapture::ByValue)
-                    && capture.place.ty().has_significant_drop(cx.tcx, cx.typing_env())
-                {
-                    locals.push(capture.var_ident.span);
-                }
-            }
-        }
-        for param in body.params {
-            if cx
-                .typeck_results()
-                .node_type(param.hir_id)
-                .has_significant_drop(cx.tcx, cx.typing_env())
-            {
-                locals.push(param.span);
-            }
-        }
-        if let hir::ExprKind::Block(block, _) = body.value.kind {
-            LintVisitor { cx, locals }.check_block_inner(block);
-        } else {
-            LintTailExpr { cx, locals: &locals, is_root_tail_expr: true }.visit_expr(body.value);
-        }
-    }
-}
-
-impl<'tcx> LateLintPass<'tcx> for TailExprDropOrder {
-    fn check_fn(
-        &mut self,
-        cx: &LateContext<'tcx>,
-        fn_kind: hir::intravisit::FnKind<'tcx>,
-        _: &'tcx hir::FnDecl<'tcx>,
-        body: &'tcx hir::Body<'tcx>,
-        _: Span,
-        def_id: rustc_span::def_id::LocalDefId,
-    ) {
-        if !body.value.span.edition().at_least_rust_2024() {
-            Self::check_fn_or_closure(cx, fn_kind, body, def_id);
-        }
-    }
-}
-
-struct LintVisitor<'a, 'tcx> {
-    cx: &'a LateContext<'tcx>,
-    // We only record locals that have significant drops
-    locals: Vec<Span>,
-}
-
-struct LocalCollector<'a, 'tcx> {
-    cx: &'a LateContext<'tcx>,
-    locals: &'a mut Vec<Span>,
-}
-
-impl<'a, 'tcx> Visitor<'tcx> for LocalCollector<'a, 'tcx> {
-    type Result = ();
-    fn visit_pat(&mut self, pat: &'tcx Pat<'tcx>) {
-        if let PatKind::Binding(_binding_mode, id, ident, pat) = pat.kind {
-            let ty = self.cx.typeck_results().node_type(id);
-            if ty.has_significant_drop(self.cx.tcx, self.cx.typing_env()) {
-                self.locals.push(ident.span);
-            }
-            if let Some(pat) = pat {
-                self.visit_pat(pat);
-            }
-        } else {
-            intravisit::walk_pat(self, pat);
-        }
-    }
-}
-
-impl<'a, 'tcx> Visitor<'tcx> for LintVisitor<'a, 'tcx> {
-    fn visit_block(&mut self, block: &'tcx Block<'tcx>) {
-        let mut locals = <_>::default();
-        swap(&mut locals, &mut self.locals);
-        self.check_block_inner(block);
-        swap(&mut locals, &mut self.locals);
-    }
-    fn visit_local(&mut self, local: &'tcx LetStmt<'tcx>) {
-        LocalCollector { cx: self.cx, locals: &mut self.locals }.visit_local(local);
-    }
-}
-
-impl<'a, 'tcx> LintVisitor<'a, 'tcx> {
-    fn check_block_inner(&mut self, block: &Block<'tcx>) {
-        if block.span.at_least_rust_2024() {
-            // We only lint up to Edition 2021
-            return;
-        }
-        let Some(tail_expr) = block.expr else { return };
-        for stmt in block.stmts {
-            match stmt.kind {
-                StmtKind::Let(let_stmt) => self.visit_local(let_stmt),
-                StmtKind::Item(_) => {}
-                StmtKind::Expr(e) | StmtKind::Semi(e) => self.visit_expr(e),
-            }
-        }
-        if self.locals.is_empty() {
-            return;
-        }
-        LintTailExpr { cx: self.cx, locals: &self.locals, is_root_tail_expr: true }
-            .visit_expr(tail_expr);
-    }
-}
-
-struct LintTailExpr<'a, 'tcx> {
-    cx: &'a LateContext<'tcx>,
-    is_root_tail_expr: bool,
-    locals: &'a [Span],
-}
-
-impl<'a, 'tcx> LintTailExpr<'a, 'tcx> {
-    fn expr_eventually_point_into_local(mut expr: &Expr<'tcx>) -> bool {
-        loop {
-            match expr.kind {
-                ExprKind::Index(access, _, _) | ExprKind::Field(access, _) => expr = access,
-                ExprKind::AddrOf(_, _, referee) | ExprKind::Unary(UnOp::Deref, referee) => {
-                    expr = referee
-                }
-                ExprKind::Path(_)
-                    if let ExprKind::Path(QPath::Resolved(_, path)) = expr.kind
-                        && let [local, ..] = path.segments
-                        && let Res::Local(_) = local.res =>
-                {
-                    return true;
-                }
-                _ => return false,
-            }
-        }
-    }
-
-    fn expr_generates_nonlocal_droppy_value(&self, expr: &Expr<'tcx>) -> bool {
-        if Self::expr_eventually_point_into_local(expr) {
-            return false;
-        }
-        self.cx
-            .typeck_results()
-            .expr_ty(expr)
-            .has_significant_drop(self.cx.tcx, self.cx.typing_env())
-    }
-}
-
-impl<'a, 'tcx> Visitor<'tcx> for LintTailExpr<'a, 'tcx> {
-    fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
-        if self.is_root_tail_expr {
-            self.is_root_tail_expr = false;
-        } else if self.expr_generates_nonlocal_droppy_value(expr) {
-            self.cx.tcx.emit_node_span_lint(
-                TAIL_EXPR_DROP_ORDER,
-                expr.hir_id,
-                expr.span,
-                TailExprDropOrderLint { spans: self.locals.to_vec() },
-            );
-            return;
-        }
-        match expr.kind {
-            ExprKind::Match(scrutinee, _, _) => self.visit_expr(scrutinee),
-
-            ExprKind::ConstBlock(_)
-            | ExprKind::Array(_)
-            | ExprKind::Break(_, _)
-            | ExprKind::Continue(_)
-            | ExprKind::Ret(_)
-            | ExprKind::Become(_)
-            | ExprKind::Yield(_, _)
-            | ExprKind::InlineAsm(_)
-            | ExprKind::If(_, _, _)
-            | ExprKind::Loop(_, _, _, _)
-            | ExprKind::Closure(_)
-            | ExprKind::DropTemps(_)
-            | ExprKind::OffsetOf(_, _)
-            | ExprKind::Assign(_, _, _)
-            | ExprKind::AssignOp(_, _, _)
-            | ExprKind::Lit(_)
-            | ExprKind::Err(_) => {}
-
-            ExprKind::MethodCall(_, _, _, _)
-            | ExprKind::Call(_, _)
-            | ExprKind::Type(_, _)
-            | ExprKind::Tup(_)
-            | ExprKind::Binary(_, _, _)
-            | ExprKind::Unary(_, _)
-            | ExprKind::Path(_)
-            | ExprKind::Let(_)
-            | ExprKind::Cast(_, _)
-            | ExprKind::Field(_, _)
-            | ExprKind::Index(_, _, _)
-            | ExprKind::AddrOf(_, _, _)
-            | ExprKind::Struct(_, _, _)
-            | ExprKind::Repeat(_, _) => intravisit::walk_expr(self, expr),
-
-            ExprKind::Block(_, _) => {
-                // We do not lint further because the drop order stays the same inside the block
-            }
-        }
-    }
-    fn visit_block(&mut self, block: &'tcx Block<'tcx>) {
-        LintVisitor { cx: self.cx, locals: <_>::default() }.check_block_inner(block);
-    }
-}
-
-#[derive(LintDiagnostic)]
-#[diag(lint_tail_expr_drop_order)]
-struct TailExprDropOrderLint {
-    #[label]
-    pub spans: Vec<Span>,
-}
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index 2e6cb993842..b1d7d4ab689 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -292,7 +292,7 @@ fn lint_wide_pointer<'tcx>(
             _ => return None,
         };
 
-        (!ty.is_sized(cx.tcx, cx.param_env))
+        (!ty.is_sized(cx.tcx, cx.typing_env()))
             .then(|| (refs, modifiers, matches!(ty.kind(), ty::Dynamic(_, _, ty::Dyn))))
     };
 
@@ -904,7 +904,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
                 if let Some(boxed) = ty.boxed_ty()
                     && matches!(self.mode, CItemKind::Definition)
                 {
-                    if boxed.is_sized(tcx, self.cx.param_env) {
+                    if boxed.is_sized(tcx, self.cx.typing_env()) {
                         return FfiSafe;
                     } else {
                         return FfiUnsafe {
@@ -1069,7 +1069,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
             ty::RawPtr(ty, _) | ty::Ref(_, ty, _)
                 if {
                     matches!(self.mode, CItemKind::Definition)
-                        && ty.is_sized(self.cx.tcx, self.cx.param_env)
+                        && ty.is_sized(self.cx.tcx, self.cx.typing_env())
                 } =>
             {
                 FfiSafe
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 313a7badf19..9036741e078 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -101,6 +101,7 @@ declare_lint_pass! {
         SINGLE_USE_LIFETIMES,
         SOFT_UNSTABLE,
         STABLE_FEATURES,
+        TAIL_EXPR_DROP_ORDER,
         TEST_UNSTABLE_LINT,
         TEXT_DIRECTION_CODEPOINT_IN_COMMENT,
         TRIVIAL_CASTS,
@@ -4995,6 +4996,83 @@ declare_lint! {
 }
 
 declare_lint! {
+    /// The `tail_expr_drop_order` lint looks for those values generated at the tail expression location,
+    /// that runs a custom `Drop` destructor.
+    /// Some of them may be dropped earlier in Edition 2024 that they used to in Edition 2021 and prior.
+    /// This lint detects those cases and provides you information on those values and their custom destructor implementations.
+    /// Your discretion on this information is required.
+    ///
+    /// ### Example
+    /// ```rust,edition2021
+    /// #![warn(tail_expr_drop_order)]
+    /// struct Droppy(i32);
+    /// impl Droppy {
+    ///     fn get(&self) -> i32 {
+    ///         self.0
+    ///     }
+    /// }
+    /// impl Drop for Droppy {
+    ///     fn drop(&mut self) {
+    ///         // This is a custom destructor and it induces side-effects that is observable
+    ///         // especially when the drop order at a tail expression changes.
+    ///         println!("loud drop {}", self.0);
+    ///     }
+    /// }
+    /// fn edition_2021() -> i32 {
+    ///     let another_droppy = Droppy(0);
+    ///     Droppy(1).get()
+    /// }
+    /// fn main() {
+    ///     edition_2021();
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// In tail expression of blocks or function bodies,
+    /// values of type with significant `Drop` implementation has an ill-specified drop order
+    /// before Edition 2024 so that they are dropped only after dropping local variables.
+    /// Edition 2024 introduces a new rule with drop orders for them,
+    /// so that they are dropped first before dropping local variables.
+    ///
+    /// A significant `Drop::drop` destructor here refers to an explicit, arbitrary
+    /// implementation of the `Drop` trait on the type, with exceptions including `Vec`,
+    /// `Box`, `Rc`, `BTreeMap` and `HashMap` that are marked by the compiler otherwise
+    /// so long that the generic types have no significant destructor recursively.
+    /// In other words, a type has a significant drop destructor when it has a `Drop` implementation
+    /// or its destructor invokes a significant destructor on a type.
+    /// Since we cannot completely reason about the change by just inspecting the existence of
+    /// a significant destructor, this lint remains only a suggestion and is set to `allow` by default.
+    ///
+    /// This lint only points out the issue with `Droppy`, which will be dropped before `another_droppy`
+    /// does in Edition 2024.
+    /// No fix will be proposed by this lint.
+    /// However, the most probable fix is to hoist `Droppy` into its own local variable binding.
+    /// ```rust
+    /// struct Droppy(i32);
+    /// impl Droppy {
+    ///     fn get(&self) -> i32 {
+    ///         self.0
+    ///     }
+    /// }
+    /// fn edition_2024() -> i32 {
+    ///     let value = Droppy(0);
+    ///     let another_droppy = Droppy(1);
+    ///     value.get()
+    /// }
+    /// ```
+    pub TAIL_EXPR_DROP_ORDER,
+    Allow,
+    "Detect and warn on significant change in drop order in tail expression location",
+    @future_incompatible = FutureIncompatibleInfo {
+        reason: FutureIncompatibilityReason::EditionSemanticsChange(Edition::Edition2024),
+        reference: "issue #123739 <https://github.com/rust-lang/rust/issues/123739>",
+    };
+}
+
+declare_lint! {
     /// The `rust_2024_guarded_string_incompatible_syntax` lint detects `#` tokens
     /// that will be parsed as part of a guarded string literal in Rust 2024.
     ///
diff --git a/compiler/rustc_lint_defs/src/lib.rs b/compiler/rustc_lint_defs/src/lib.rs
index eac4afee050..c74fceeedba 100644
--- a/compiler/rustc_lint_defs/src/lib.rs
+++ b/compiler/rustc_lint_defs/src/lib.rs
@@ -466,6 +466,20 @@ impl FutureIncompatibilityReason {
             | FutureIncompatibilityReason::Custom(_) => None,
         }
     }
+
+    pub fn has_future_breakage(self) -> bool {
+        match self {
+            FutureIncompatibilityReason::FutureReleaseErrorReportInDeps => true,
+
+            FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps
+            | FutureIncompatibilityReason::FutureReleaseSemanticsChange
+            | FutureIncompatibilityReason::EditionError(_)
+            | FutureIncompatibilityReason::EditionSemanticsChange(_)
+            | FutureIncompatibilityReason::EditionAndFutureReleaseError(_)
+            | FutureIncompatibilityReason::EditionAndFutureReleaseSemanticsChange(_)
+            | FutureIncompatibilityReason::Custom(_) => false,
+        }
+    }
 }
 
 impl FutureIncompatibleInfo {
diff --git a/compiler/rustc_middle/src/lint.rs b/compiler/rustc_middle/src/lint.rs
index 92ba6ceee93..971d036fa69 100644
--- a/compiler/rustc_middle/src/lint.rs
+++ b/compiler/rustc_middle/src/lint.rs
@@ -290,12 +290,7 @@ pub fn lint_level(
         let has_future_breakage = future_incompatible.map_or(
             // Default allow lints trigger too often for testing.
             sess.opts.unstable_opts.future_incompat_test && lint.default_level != Level::Allow,
-            |incompat| {
-                matches!(
-                    incompat.reason,
-                    FutureIncompatibilityReason::FutureReleaseErrorReportInDeps
-                )
-            },
+            |incompat| incompat.reason.has_future_breakage(),
         );
 
         // Convert lint level to error level.
diff --git a/compiler/rustc_middle/src/middle/region.rs b/compiler/rustc_middle/src/middle/region.rs
index 4e44de33611..114211b27c1 100644
--- a/compiler/rustc_middle/src/middle/region.rs
+++ b/compiler/rustc_middle/src/middle/region.rs
@@ -236,6 +236,11 @@ pub struct ScopeTree {
     /// during type check based on a traversal of the AST.
     pub rvalue_candidates: HirIdMap<RvalueCandidateType>,
 
+    /// Backwards incompatible scoping that will be introduced in future editions.
+    /// This information is used later for linting to identify locals and
+    /// temporary values that will receive backwards-incompatible drop orders.
+    pub backwards_incompatible_scope: UnordMap<hir::ItemLocalId, Scope>,
+
     /// If there are any `yield` nested within a scope, this map
     /// stores the `Span` of the last one and its index in the
     /// postorder of the Visitor traversal on the HIR.
diff --git a/compiler/rustc_middle/src/mir/interpret/mod.rs b/compiler/rustc_middle/src/mir/interpret/mod.rs
index c4b0e6e39cc..8d73c9e76de 100644
--- a/compiler/rustc_middle/src/mir/interpret/mod.rs
+++ b/compiler/rustc_middle/src/mir/interpret/mod.rs
@@ -46,7 +46,7 @@ pub use self::pointer::{CtfeProvenance, Pointer, PointerArithmetic, Provenance};
 pub use self::value::Scalar;
 use crate::mir;
 use crate::ty::codec::{TyDecoder, TyEncoder};
-use crate::ty::{self, Instance, ParamEnv, Ty, TyCtxt};
+use crate::ty::{self, Instance, Ty, TyCtxt};
 
 /// Uniquely identifies one of the following:
 /// - A constant
@@ -312,7 +312,7 @@ impl<'tcx> GlobalAlloc<'tcx> {
         }
     }
 
-    pub fn mutability(&self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> Mutability {
+    pub fn mutability(&self, tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>) -> Mutability {
         // Let's see what kind of memory we are.
         match self {
             GlobalAlloc::Static(did) => {
@@ -334,7 +334,7 @@ impl<'tcx> GlobalAlloc<'tcx> {
                                 .type_of(did)
                                 .no_bound_vars()
                                 .expect("statics should not have generic parameters")
-                                .is_freeze(tcx, param_env) =>
+                                .is_freeze(tcx, typing_env) =>
                         {
                             Mutability::Mut
                         }
diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs
index 7092f87a7d1..6eeafe18b35 100644
--- a/compiler/rustc_middle/src/mir/interpret/queries.rs
+++ b/compiler/rustc_middle/src/mir/interpret/queries.rs
@@ -25,8 +25,8 @@ impl<'tcx> TyCtxt<'tcx> {
         let args = GenericArgs::identity_for_item(self, def_id);
         let instance = ty::Instance::new(def_id, args);
         let cid = GlobalId { instance, promoted: None };
-        let param_env = self.param_env(def_id).with_reveal_all_normalized(self);
-        self.const_eval_global_id(param_env, cid, DUMMY_SP)
+        let typing_env = ty::TypingEnv::post_analysis(self, def_id);
+        self.const_eval_global_id(typing_env, cid, DUMMY_SP)
     }
 
     /// Evaluates a constant without providing any generic parameters. This is useful to evaluate consts
@@ -41,8 +41,8 @@ impl<'tcx> TyCtxt<'tcx> {
         let args = GenericArgs::identity_for_item(self, def_id);
         let instance = ty::Instance::new(def_id, args);
         let cid = GlobalId { instance, promoted: None };
-        let param_env = self.param_env(def_id).with_reveal_all_normalized(self);
-        let inputs = self.erase_regions(param_env.and(cid));
+        let typing_env = ty::TypingEnv::post_analysis(self, def_id);
+        let inputs = self.erase_regions(typing_env.as_query_input(cid));
         self.eval_to_allocation_raw(inputs)
     }
 
@@ -76,7 +76,7 @@ impl<'tcx> TyCtxt<'tcx> {
         match ty::Instance::try_resolve(self, typing_env, ct.def, ct.args) {
             Ok(Some(instance)) => {
                 let cid = GlobalId { instance, promoted: ct.promoted };
-                self.const_eval_global_id(typing_env.param_env, cid, span)
+                self.const_eval_global_id(typing_env, cid, span)
             }
             // For errors during resolution, we deliberately do not point at the usage site of the constant,
             // since for these errors the place the constant is used shouldn't matter.
@@ -105,7 +105,7 @@ impl<'tcx> TyCtxt<'tcx> {
         match ty::Instance::try_resolve(self, typing_env, ct.def, ct.args) {
             Ok(Some(instance)) => {
                 let cid = GlobalId { instance, promoted: None };
-                self.const_eval_global_id_for_typeck(typing_env.param_env, cid, span).inspect(|_| {
+                self.const_eval_global_id_for_typeck(typing_env, cid, span).inspect(|_| {
                     // We are emitting the lint here instead of in `is_const_evaluatable`
                     // as we normalize obligations before checking them, and normalization
                     // uses this function to evaluate this constant.
@@ -144,24 +144,25 @@ impl<'tcx> TyCtxt<'tcx> {
 
     pub fn const_eval_instance(
         self,
-        param_env: ty::ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
         instance: ty::Instance<'tcx>,
         span: Span,
     ) -> EvalToConstValueResult<'tcx> {
-        self.const_eval_global_id(param_env, GlobalId { instance, promoted: None }, span)
+        self.const_eval_global_id(typing_env, GlobalId { instance, promoted: None }, span)
     }
 
     /// Evaluate a constant to a `ConstValue`.
     #[instrument(skip(self), level = "debug")]
     pub fn const_eval_global_id(
         self,
-        param_env: ty::ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
         cid: GlobalId<'tcx>,
         span: Span,
     ) -> EvalToConstValueResult<'tcx> {
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
         // improve caching of queries.
-        let inputs = self.erase_regions(param_env.with_reveal_all_normalized(self).and(cid));
+        let inputs =
+            self.erase_regions(typing_env.with_reveal_all_normalized(self).as_query_input(cid));
         if !span.is_dummy() {
             // The query doesn't know where it is being invoked, so we need to fix the span.
             self.at(span).eval_to_const_value_raw(inputs).map_err(|e| e.with_span(span))
@@ -174,13 +175,14 @@ impl<'tcx> TyCtxt<'tcx> {
     #[instrument(skip(self), level = "debug")]
     pub fn const_eval_global_id_for_typeck(
         self,
-        param_env: ty::ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
         cid: GlobalId<'tcx>,
         span: Span,
     ) -> EvalToValTreeResult<'tcx> {
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
         // improve caching of queries.
-        let inputs = self.erase_regions(param_env.with_reveal_all_normalized(self).and(cid));
+        let inputs =
+            self.erase_regions(typing_env.with_reveal_all_normalized(self).as_query_input(cid));
         debug!(?inputs);
         if !span.is_dummy() {
             // The query doesn't know where it is being invoked, so we need to fix the span.
@@ -202,12 +204,12 @@ impl<'tcx> TyCtxtEnsure<'tcx> {
         // into `const_eval` which will return `ErrorHandled::ToGeneric` if any of them are
         // encountered.
         let args = GenericArgs::identity_for_item(self.tcx, def_id);
-        let instance = ty::Instance::new(def_id, args);
+        let instance = ty::Instance::new(def_id, self.tcx.erase_regions(args));
         let cid = GlobalId { instance, promoted: None };
-        let param_env = self.tcx.param_env(def_id).with_reveal_all_normalized(self.tcx);
+        let typing_env = ty::TypingEnv::post_analysis(self.tcx, def_id);
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
         // improve caching of queries.
-        let inputs = self.tcx.erase_regions(param_env.and(cid));
+        let inputs = self.tcx.erase_regions(typing_env.as_query_input(cid));
         self.eval_to_const_value_raw(inputs)
     }
 }
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 425cb059e57..e2379f282ec 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -459,10 +459,7 @@ impl<'tcx> Body<'tcx> {
                 typing_mode: ty::TypingMode::non_body_analysis(),
                 param_env: tcx.param_env(self.source.def_id()),
             },
-            MirPhase::Runtime(_) => TypingEnv {
-                typing_mode: ty::TypingMode::PostAnalysis,
-                param_env: tcx.param_env_reveal_all_normalized(self.source.def_id()),
-            },
+            MirPhase::Runtime(_) => TypingEnv::post_analysis(tcx, self.source.def_id()),
         }
     }
 
diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index f0e2b7a376c..2bfcd0a6227 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -834,6 +834,11 @@ impl Debug for Statement<'_> {
             Intrinsic(box ref intrinsic) => write!(fmt, "{intrinsic}"),
             ConstEvalCounter => write!(fmt, "ConstEvalCounter"),
             Nop => write!(fmt, "nop"),
+            BackwardIncompatibleDropHint { ref place, reason: _ } => {
+                // For now, we don't record the reason because there is only one use case,
+                // which is to report breaking change in drop order by Edition 2024
+                write!(fmt, "backward incompatible drop({place:?})")
+            }
         }
     }
 }
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index 2083279e128..fea940ea47c 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -432,6 +432,18 @@ pub enum StatementKind<'tcx> {
 
     /// No-op. Useful for deleting instructions without affecting statement indices.
     Nop,
+
+    /// Marker statement indicating where `place` would be dropped.
+    /// This is semantically equivalent to `Nop`, so codegen and MIRI should interpret this
+    /// statement as such.
+    /// The only use case of this statement is for linting in MIR to detect temporary lifetime
+    /// changes.
+    BackwardIncompatibleDropHint {
+        /// Place to drop
+        place: Box<Place<'tcx>>,
+        /// Reason for backward incompatibility
+        reason: BackwardIncompatibleDropReason,
+    },
 }
 
 impl StatementKind<'_> {
@@ -452,6 +464,7 @@ impl StatementKind<'_> {
             StatementKind::Intrinsic(..) => "Intrinsic",
             StatementKind::ConstEvalCounter => "ConstEvalCounter",
             StatementKind::Nop => "Nop",
+            StatementKind::BackwardIncompatibleDropHint { .. } => "BackwardIncompatibleDropHint",
         }
     }
 }
@@ -897,6 +910,21 @@ pub enum TerminatorKind<'tcx> {
     },
 }
 
+#[derive(
+    Clone,
+    Debug,
+    TyEncodable,
+    TyDecodable,
+    Hash,
+    HashStable,
+    PartialEq,
+    TypeFoldable,
+    TypeVisitable
+)]
+pub enum BackwardIncompatibleDropReason {
+    Edition2024,
+}
+
 impl TerminatorKind<'_> {
     /// Returns a simple string representation of a `TerminatorKind` variant, independent of any
     /// values it might hold (e.g. `TerminatorKind::Call` always returns `"Call"`).
diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs
index 9f9ee8497b6..62c340d99e3 100644
--- a/compiler/rustc_middle/src/mir/visit.rs
+++ b/compiler/rustc_middle/src/mir/visit.rs
@@ -452,6 +452,7 @@ macro_rules! make_mir_visitor {
                     }
                     StatementKind::ConstEvalCounter => {}
                     StatementKind::Nop => {}
+                    StatementKind::BackwardIncompatibleDropHint { .. } => {}
                 }
             }
 
diff --git a/compiler/rustc_middle/src/query/keys.rs b/compiler/rustc_middle/src/query/keys.rs
index d2fab8e78d5..970dc72e1ff 100644
--- a/compiler/rustc_middle/src/query/keys.rs
+++ b/compiler/rustc_middle/src/query/keys.rs
@@ -360,6 +360,14 @@ impl<'tcx> Key for (ty::ParamEnv<'tcx>, ty::TraitRef<'tcx>) {
     }
 }
 
+impl<'tcx> Key for ty::ParamEnvAnd<'tcx, Ty<'tcx>> {
+    type Cache<V> = DefaultCache<Self, V>;
+
+    fn default_span(&self, _tcx: TyCtxt<'_>) -> Span {
+        DUMMY_SP
+    }
+}
+
 impl<'tcx> Key for ty::TraitRef<'tcx> {
     type Cache<V> = DefaultCache<Self, V>;
 
@@ -456,18 +464,6 @@ impl<'tcx> Key for ty::ParamEnv<'tcx> {
     }
 }
 
-impl<'tcx, T: Key> Key for ty::ParamEnvAnd<'tcx, T> {
-    type Cache<V> = DefaultCache<Self, V>;
-
-    fn default_span(&self, tcx: TyCtxt<'_>) -> Span {
-        self.value.default_span(tcx)
-    }
-
-    fn ty_def_id(&self) -> Option<DefId> {
-        self.value.ty_def_id()
-    }
-}
-
 impl<'tcx, T: Key> Key for ty::PseudoCanonicalInput<'tcx, T> {
     type Cache<V> = DefaultCache<Self, V>;
 
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 684d5b6c2a7..3fdb38a433e 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1095,7 +1095,7 @@ rustc_queries! {
     /// Evaluates a constant and returns the computed allocation.
     ///
     /// **Do not use this** directly, use the `eval_to_const_value` or `eval_to_valtree` instead.
-    query eval_to_allocation_raw(key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>)
+    query eval_to_allocation_raw(key: ty::PseudoCanonicalInput<'tcx, GlobalId<'tcx>>)
         -> EvalToAllocationRawResult<'tcx> {
         desc { |tcx|
             "const-evaluating + checking `{}`",
@@ -1121,7 +1121,7 @@ rustc_queries! {
     ///
     /// **Do not use this** directly, use one of the following wrappers: `tcx.const_eval_poly`,
     /// `tcx.const_eval_resolve`, `tcx.const_eval_instance`, or `tcx.const_eval_global_id`.
-    query eval_to_const_value_raw(key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>)
+    query eval_to_const_value_raw(key: ty::PseudoCanonicalInput<'tcx, GlobalId<'tcx>>)
         -> EvalToConstValueResult<'tcx> {
         desc { |tcx|
             "simplifying constant for the type system `{}`",
@@ -1133,7 +1133,7 @@ rustc_queries! {
     /// Evaluate a constant and convert it to a type level constant or
     /// return `None` if that is not possible.
     query eval_to_valtree(
-        key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>
+        key: ty::PseudoCanonicalInput<'tcx, GlobalId<'tcx>>
     ) -> EvalToValTreeResult<'tcx> {
         desc { "evaluating type-level constant" }
     }
@@ -1390,19 +1390,19 @@ rustc_queries! {
 
     /// Trait selection queries. These are best used by invoking `ty.is_copy_modulo_regions()`,
     /// `ty.is_copy()`, etc, since that will prune the environment where possible.
-    query is_copy_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    query is_copy_raw(env: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Copy`", env.value }
     }
     /// Query backing `Ty::is_sized`.
-    query is_sized_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    query is_sized_raw(env: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Sized`", env.value }
     }
     /// Query backing `Ty::is_freeze`.
-    query is_freeze_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    query is_freeze_raw(env: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is freeze", env.value }
     }
     /// Query backing `Ty::is_unpin`.
-    query is_unpin_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+    query is_unpin_raw(env: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Unpin`", env.value }
     }
     /// Query backing `Ty::needs_drop`.
@@ -1448,6 +1448,28 @@ rustc_queries! {
         cache_on_disk_if { false }
     }
 
+    /// Returns a list of types which (a) have a potentially significant destructor
+    /// and (b) may be dropped as a result of dropping a value of some type `ty`
+    /// (in the given environment).
+    ///
+    /// The idea of "significant" drop is somewhat informal and is used only for
+    /// diagnostics and edition migrations. The idea is that a significant drop may have
+    /// some visible side-effect on execution; freeing memory is NOT considered a side-effect.
+    /// The rules are as follows:
+    /// * Type with no explicit drop impl do not have significant drop.
+    /// * Types with a drop impl are assumed to have significant drop unless they have a `#[rustc_insignificant_dtor]` annotation.
+    ///
+    /// Note that insignificant drop is a "shallow" property. A type like `Vec<LockGuard>` does not
+    /// have significant drop but the type `LockGuard` does, and so if `ty  = Vec<LockGuard>`
+    /// then the return value would be `&[LockGuard]`.
+    /// *IMPORTANT*: *DO NOT* run this query before promoted MIR body is constructed,
+    /// because this query partially depends on that query.
+    /// Otherwise, there is a risk of query cycles.
+    query list_significant_drop_tys(ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> &'tcx ty::List<Ty<'tcx>> {
+        desc { |tcx| "computing when `{}` has a significant destructor", ty.value }
+        cache_on_disk_if { false }
+    }
+
     /// Computes the layout of a type. Note that this implicitly
     /// executes in "reveal all" mode, and will normalize the input type.
     query layout_of(
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs
index 0e5b56d3491..9cf6bc1b777 100644
--- a/compiler/rustc_middle/src/thir.rs
+++ b/compiler/rustc_middle/src/thir.rs
@@ -247,13 +247,24 @@ pub struct Expr<'tcx> {
     pub ty: Ty<'tcx>,
 
     /// The lifetime of this expression if it should be spilled into a
-    /// temporary; should be `None` only if in a constant context
-    pub temp_lifetime: Option<region::Scope>,
+    /// temporary
+    pub temp_lifetime: TempLifetime,
 
     /// span of the expression in the source
     pub span: Span,
 }
 
+/// Temporary lifetime information for THIR expressions
+#[derive(Clone, Copy, Debug, HashStable)]
+pub struct TempLifetime {
+    /// Lifetime for temporaries as expected.
+    /// This should be `None` in a constant context.
+    pub temp_lifetime: Option<region::Scope>,
+    /// If `Some(lt)`, indicates that the lifetime of this temporary will change to `lt` in a future edition.
+    /// If `None`, then no changes are expected, or lints are disabled.
+    pub backwards_incompatible: Option<region::Scope>,
+}
+
 #[derive(Clone, Debug, HashStable)]
 pub enum ExprKind<'tcx> {
     /// `Scope`s are used to explicitly mark destruction scopes,
@@ -1092,7 +1103,7 @@ mod size_asserts {
     use super::*;
     // tidy-alphabetical-start
     static_assert_size!(Block, 48);
-    static_assert_size!(Expr<'_>, 64);
+    static_assert_size!(Expr<'_>, 72);
     static_assert_size!(ExprKind<'_>, 40);
     static_assert_size!(Pat<'_>, 64);
     static_assert_size!(PatKind<'_>, 48);
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 68c3b064eee..b4d29f08a0f 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -376,7 +376,11 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
         self.explicit_implied_predicates_of(def_id).map_bound(|preds| preds.into_iter().copied())
     }
 
-    fn is_const_impl(self, def_id: DefId) -> bool {
+    fn impl_is_const(self, def_id: DefId) -> bool {
+        self.is_conditionally_const(def_id)
+    }
+
+    fn fn_is_const(self, def_id: DefId) -> bool {
         self.is_conditionally_const(def_id)
     }
 
@@ -598,19 +602,6 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
         self.coroutine_is_async_gen(coroutine_def_id)
     }
 
-    // We don't use `TypingEnv` here as it's only defined in `rustc_middle` and
-    // `rustc_next_trait_solver` shouldn't have to know about it.
-    fn layout_is_pointer_like(
-        self,
-        typing_mode: ty::TypingMode<'tcx>,
-        param_env: ty::ParamEnv<'tcx>,
-        ty: Ty<'tcx>,
-    ) -> bool {
-        let typing_env = ty::TypingEnv { typing_mode, param_env };
-        self.layout_of(self.erase_regions(typing_env).as_query_input(self.erase_regions(ty)))
-            .is_ok_and(|layout| layout.layout.is_pointer_like(&self.data_layout))
-    }
-
     type UnsizingParams = &'tcx rustc_index::bit_set::BitSet<u32>;
     fn unsizing_params_for_adt(self, adt_def_id: DefId) -> Self::UnsizingParams {
         self.unsizing_params_for_adt(adt_def_id)
@@ -684,7 +675,6 @@ bidirectional_lang_item_map! {
     Metadata,
     Option,
     PointeeTrait,
-    PointerLike,
     Poll,
     Sized,
     TransmuteTrait,
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index d42b6be4787..dab3e18de33 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -537,9 +537,7 @@ impl<'tcx> Instance<'tcx> {
 
         // All regions in the result of this query are erased, so it's
         // fine to erase all of the input regions.
-        let typing_env = tcx.erase_regions(typing_env);
-        let args = tcx.erase_regions(args);
-        tcx.resolve_instance_raw(typing_env.as_query_input((def_id, args)))
+        tcx.resolve_instance_raw(tcx.erase_regions(typing_env.as_query_input((def_id, args))))
     }
 
     pub fn expect_resolve(
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 8625a8dcb2a..fc29b438d3a 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -1002,12 +1002,12 @@ where
                 // attributes in LLVM have compile-time cost even in unoptimized builds).
                 let optimize = tcx.sess.opts.optimize != OptLevel::No;
                 let kind = match mt {
-                    hir::Mutability::Not => PointerKind::SharedRef {
-                        frozen: optimize && ty.is_freeze(tcx, typing_env.param_env),
-                    },
-                    hir::Mutability::Mut => PointerKind::MutableRef {
-                        unpin: optimize && ty.is_unpin(tcx, typing_env.param_env),
-                    },
+                    hir::Mutability::Not => {
+                        PointerKind::SharedRef { frozen: optimize && ty.is_freeze(tcx, typing_env) }
+                    }
+                    hir::Mutability::Mut => {
+                        PointerKind::MutableRef { unpin: optimize && ty.is_unpin(tcx, typing_env) }
+                    }
                 };
 
                 tcx.layout_of(typing_env.as_query_input(ty)).ok().map(|layout| PointeeInfo {
@@ -1100,7 +1100,7 @@ where
                         debug_assert!(pointee.safe.is_none());
                         let optimize = tcx.sess.opts.optimize != OptLevel::No;
                         pointee.safe = Some(PointerKind::Box {
-                            unpin: optimize && boxed_ty.is_unpin(tcx, typing_env.param_env),
+                            unpin: optimize && boxed_ty.is_unpin(tcx, typing_env),
                             global: this.ty.is_box_global(tcx),
                         });
                     }
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 965a8c8c95e..dd8286c8eb9 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1140,12 +1140,6 @@ pub struct TypingEnv<'tcx> {
 }
 
 impl<'tcx> TypingEnv<'tcx> {
-    // FIXME(#132279): This method should be removed but simplifies the
-    // transition.
-    pub fn from_param_env(param_env: ParamEnv<'tcx>) -> TypingEnv<'tcx> {
-        TypingEnv { typing_mode: TypingMode::from_param_env(param_env), param_env }
-    }
-
     /// Create a typing environment with no where-clauses in scope
     /// where all opaque types and default associated items are revealed.
     ///
@@ -1192,7 +1186,6 @@ impl<'tcx> TypingEnv<'tcx> {
     where
         T: TypeVisitable<TyCtxt<'tcx>>,
     {
-        debug_assert!(!value.has_infer());
         // FIXME(#132279): We should assert that the value does not contain any placeholders
         // as these placeholders are also local to the current inference context. However, we
         // currently use pseudo-canonical queries in the trait solver which replaces params with
@@ -1215,7 +1208,7 @@ impl<'tcx> TypingEnv<'tcx> {
 /// This should be created by using `infcx.pseudo_canonicalize_query(param_env, value)`
 /// or by using `typing_env.as_query_input(value)`.
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
-#[derive(HashStable)]
+#[derive(HashStable, TypeVisitable, TypeFoldable)]
 pub struct PseudoCanonicalInput<'tcx, T> {
     pub typing_env: TypingEnv<'tcx>,
     pub value: T,
diff --git a/compiler/rustc_middle/src/ty/rvalue_scopes.rs b/compiler/rustc_middle/src/ty/rvalue_scopes.rs
index 37dcf7c0d64..57c2d7623d2 100644
--- a/compiler/rustc_middle/src/ty/rvalue_scopes.rs
+++ b/compiler/rustc_middle/src/ty/rvalue_scopes.rs
@@ -18,15 +18,17 @@ impl RvalueScopes {
     }
 
     /// Returns the scope when the temp created by `expr_id` will be cleaned up.
+    /// It also emits a lint on potential backwards incompatible change to the temporary scope
+    /// which is *for now* always shortening.
     pub fn temporary_scope(
         &self,
         region_scope_tree: &ScopeTree,
         expr_id: hir::ItemLocalId,
-    ) -> Option<Scope> {
+    ) -> (Option<Scope>, Option<Scope>) {
         // Check for a designated rvalue scope.
         if let Some(&s) = self.map.get(&expr_id) {
             debug!("temporary_scope({expr_id:?}) = {s:?} [custom]");
-            return s;
+            return (s, None);
         }
 
         // Otherwise, locate the innermost terminating scope
@@ -34,27 +36,40 @@ impl RvalueScopes {
         // have an enclosing scope, hence no scope will be
         // returned.
         let mut id = Scope { id: expr_id, data: ScopeData::Node };
+        let mut backwards_incompatible = None;
 
         while let Some(&(p, _)) = region_scope_tree.parent_map.get(&id) {
             match p.data {
                 ScopeData::Destruction => {
                     debug!("temporary_scope({expr_id:?}) = {id:?} [enclosing]");
-                    return Some(id);
+                    return (Some(id), backwards_incompatible);
                 }
                 ScopeData::IfThenRescope => {
                     debug!("temporary_scope({expr_id:?}) = {p:?} [enclosing]");
-                    return Some(p);
+                    return (Some(p), backwards_incompatible);
                 }
                 ScopeData::Node
                 | ScopeData::CallSite
                 | ScopeData::Arguments
                 | ScopeData::IfThen
-                | ScopeData::Remainder(_) => id = p,
+                | ScopeData::Remainder(_) => {
+                    // If we haven't already passed through a backwards-incompatible node,
+                    // then check if we are passing through one now and record it if so.
+                    // This is for now only working for cases where a temporary lifetime is
+                    // *shortened*.
+                    if backwards_incompatible.is_none() {
+                        backwards_incompatible = region_scope_tree
+                            .backwards_incompatible_scope
+                            .get(&p.item_local_id())
+                            .copied();
+                    }
+                    id = p
+                }
             }
         }
 
         debug!("temporary_scope({expr_id:?}) = None");
-        None
+        (None, backwards_incompatible)
     }
 
     /// Make an association between a sub-expression and an extended lifetime
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 703a7826b7a..20c3f84bb4d 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -1180,8 +1180,12 @@ impl<'tcx> Ty<'tcx> {
     /// does copies even when the type actually doesn't satisfy the
     /// full requirements for the `Copy` trait (cc #29149) -- this
     /// winds up being reported as an error during NLL borrow check.
-    pub fn is_copy_modulo_regions(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
-        self.is_trivially_pure_clone_copy() || tcx.is_copy_raw(param_env.and(self))
+    pub fn is_copy_modulo_regions(
+        self,
+        tcx: TyCtxt<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
+    ) -> bool {
+        self.is_trivially_pure_clone_copy() || tcx.is_copy_raw(typing_env.as_query_input(self))
     }
 
     /// Checks whether values of this type `T` have a size known at
@@ -1190,8 +1194,8 @@ impl<'tcx> Ty<'tcx> {
     /// over-approximation in generic contexts, where one can have
     /// strange rules like `<T as Foo<'static>>::Bar: Sized` that
     /// actually carry lifetime requirements.
-    pub fn is_sized(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
-        self.is_trivially_sized(tcx) || tcx.is_sized_raw(param_env.and(self))
+    pub fn is_sized(self, tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>) -> bool {
+        self.is_trivially_sized(tcx) || tcx.is_sized_raw(typing_env.as_query_input(self))
     }
 
     /// Checks whether values of this type `T` implement the `Freeze`
@@ -1201,8 +1205,8 @@ impl<'tcx> Ty<'tcx> {
     /// optimization as well as the rules around static values. Note
     /// that the `Freeze` trait is not exposed to end users and is
     /// effectively an implementation detail.
-    pub fn is_freeze(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
-        self.is_trivially_freeze() || tcx.is_freeze_raw(param_env.and(self))
+    pub fn is_freeze(self, tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>) -> bool {
+        self.is_trivially_freeze() || tcx.is_freeze_raw(typing_env.as_query_input(self))
     }
 
     /// Fast path helper for testing if a type is `Freeze`.
@@ -1241,8 +1245,8 @@ impl<'tcx> Ty<'tcx> {
     }
 
     /// Checks whether values of this type `T` implement the `Unpin` trait.
-    pub fn is_unpin(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
-        self.is_trivially_unpin() || tcx.is_unpin_raw(param_env.and(self))
+    pub fn is_unpin(self, tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>) -> bool {
+        self.is_trivially_unpin() || tcx.is_unpin_raw(typing_env.as_query_input(self))
     }
 
     /// Fast path helper for testing if a type is `Unpin`.
diff --git a/compiler/rustc_mir_build/src/build/expr/as_operand.rs b/compiler/rustc_mir_build/src/build/expr/as_operand.rs
index aad7d54833b..0cab853196b 100644
--- a/compiler/rustc_mir_build/src/build/expr/as_operand.rs
+++ b/compiler/rustc_mir_build/src/build/expr/as_operand.rs
@@ -1,6 +1,5 @@
 //! See docs in build/expr/mod.rs
 
-use rustc_middle::middle::region;
 use rustc_middle::mir::*;
 use rustc_middle::thir::*;
 use tracing::{debug, instrument};
@@ -9,6 +8,12 @@ use crate::build::expr::category::Category;
 use crate::build::{BlockAnd, BlockAndExtension, Builder, NeedsTemporary};
 
 impl<'a, 'tcx> Builder<'a, 'tcx> {
+    /// Construct a temporary lifetime restricted to just the local scope
+    pub(crate) fn local_temp_lifetime(&self) -> TempLifetime {
+        let local_scope = self.local_scope();
+        TempLifetime { temp_lifetime: Some(local_scope), backwards_incompatible: None }
+    }
+
     /// Returns an operand suitable for use until the end of the current
     /// scope expression.
     ///
@@ -21,8 +26,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         block: BasicBlock,
         expr_id: ExprId,
     ) -> BlockAnd<Operand<'tcx>> {
-        let local_scope = self.local_scope();
-        self.as_operand(block, Some(local_scope), expr_id, LocalInfo::Boring, NeedsTemporary::Maybe)
+        self.as_operand(
+            block,
+            self.local_temp_lifetime(),
+            expr_id,
+            LocalInfo::Boring,
+            NeedsTemporary::Maybe,
+        )
     }
 
     /// Returns an operand suitable for use until the end of the current scope expression and
@@ -80,8 +90,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         block: BasicBlock,
         expr: ExprId,
     ) -> BlockAnd<Operand<'tcx>> {
-        let local_scope = self.local_scope();
-        self.as_call_operand(block, Some(local_scope), expr)
+        self.as_call_operand(block, self.local_temp_lifetime(), expr)
     }
 
     /// Compile `expr` into a value that can be used as an operand.
@@ -102,7 +111,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     pub(crate) fn as_operand(
         &mut self,
         mut block: BasicBlock,
-        scope: Option<region::Scope>,
+        scope: TempLifetime,
         expr_id: ExprId,
         local_info: LocalInfo<'tcx>,
         needs_temporary: NeedsTemporary,
@@ -146,7 +155,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     pub(crate) fn as_call_operand(
         &mut self,
         mut block: BasicBlock,
-        scope: Option<region::Scope>,
+        scope: TempLifetime,
         expr_id: ExprId,
     ) -> BlockAnd<Operand<'tcx>> {
         let this = self;
@@ -165,11 +174,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         if tcx.features().unsized_fn_params() {
             let ty = expr.ty;
-            let param_env = this.param_env;
-
-            if !ty.is_sized(tcx, param_env) {
+            if !ty.is_sized(tcx, this.typing_env()) {
                 // !sized means !copy, so this is an unsized move
-                assert!(!ty.is_copy_modulo_regions(tcx, param_env));
+                assert!(!ty.is_copy_modulo_regions(tcx, this.typing_env()));
 
                 // As described above, detect the case where we are passing a value of unsized
                 // type, and that value is coming from the deref of a box.
diff --git a/compiler/rustc_mir_build/src/build/expr/as_place.rs b/compiler/rustc_mir_build/src/build/expr/as_place.rs
index 9f6e0735b48..6ce88cdc39d 100644
--- a/compiler/rustc_mir_build/src/build/expr/as_place.rs
+++ b/compiler/rustc_mir_build/src/build/expr/as_place.rs
@@ -6,7 +6,6 @@ use std::iter;
 use rustc_abi::{FIRST_VARIANT, FieldIdx, VariantIdx};
 use rustc_hir::def_id::LocalDefId;
 use rustc_middle::hir::place::{Projection as HirProjection, ProjectionKind as HirProjectionKind};
-use rustc_middle::middle::region;
 use rustc_middle::mir::AssertKind::BoundsCheck;
 use rustc_middle::mir::*;
 use rustc_middle::thir::*;
@@ -598,7 +597,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         index: ExprId,
         mutability: Mutability,
         fake_borrow_temps: Option<&mut Vec<Local>>,
-        temp_lifetime: Option<region::Scope>,
+        temp_lifetime: TempLifetime,
         expr_span: Span,
         source_info: SourceInfo,
     ) -> BlockAnd<PlaceBuilder<'tcx>> {
diff --git a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs
index a3fee38908b..3f89e337781 100644
--- a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs
+++ b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs
@@ -33,14 +33,18 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         expr_id: ExprId,
     ) -> BlockAnd<Rvalue<'tcx>> {
         let local_scope = self.local_scope();
-        self.as_rvalue(block, Some(local_scope), expr_id)
+        self.as_rvalue(
+            block,
+            TempLifetime { temp_lifetime: Some(local_scope), backwards_incompatible: None },
+            expr_id,
+        )
     }
 
     /// Compile `expr`, yielding an rvalue.
     pub(crate) fn as_rvalue(
         &mut self,
         mut block: BasicBlock,
-        scope: Option<region::Scope>,
+        scope: TempLifetime,
         expr_id: ExprId,
     ) -> BlockAnd<Rvalue<'tcx>> {
         let this = self;
@@ -171,7 +175,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     source_info,
                     kind: StatementKind::StorageLive(result),
                 });
-                if let Some(scope) = scope {
+                if let Some(scope) = scope.temp_lifetime {
                     // schedule a shallow free of that memory, lest we unwind:
                     this.schedule_drop_storage_and_value(expr_span, scope, result);
                 }
@@ -445,7 +449,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                                         block = this.limit_capture_mutability(
                                             upvar_expr.span,
                                             upvar_expr.ty,
-                                            scope,
+                                            scope.temp_lifetime,
                                             block,
                                             arg,
                                         )
@@ -705,7 +709,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         &mut self,
         mut block: BasicBlock,
         value: ExprId,
-        scope: Option<region::Scope>,
+        scope: TempLifetime,
         outer_source_info: SourceInfo,
     ) -> BlockAnd<Rvalue<'tcx>> {
         let this = self;
diff --git a/compiler/rustc_mir_build/src/build/expr/as_temp.rs b/compiler/rustc_mir_build/src/build/expr/as_temp.rs
index b8b5e4634ed..466f67b1ba4 100644
--- a/compiler/rustc_mir_build/src/build/expr/as_temp.rs
+++ b/compiler/rustc_mir_build/src/build/expr/as_temp.rs
@@ -2,7 +2,6 @@
 
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::HirId;
-use rustc_middle::middle::region;
 use rustc_middle::middle::region::{Scope, ScopeData};
 use rustc_middle::mir::*;
 use rustc_middle::thir::*;
@@ -17,7 +16,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     pub(crate) fn as_temp(
         &mut self,
         block: BasicBlock,
-        temp_lifetime: Option<region::Scope>,
+        temp_lifetime: TempLifetime,
         expr_id: ExprId,
         mutability: Mutability,
     ) -> BlockAnd<Local> {
@@ -31,7 +30,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     fn as_temp_inner(
         &mut self,
         mut block: BasicBlock,
-        temp_lifetime: Option<region::Scope>,
+        temp_lifetime: TempLifetime,
         expr_id: ExprId,
         mutability: Mutability,
     ) -> BlockAnd<Local> {
@@ -47,8 +46,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         }
 
         let expr_ty = expr.ty;
-        let deduplicate_temps =
-            this.fixed_temps_scope.is_some() && this.fixed_temps_scope == temp_lifetime;
+        let deduplicate_temps = this.fixed_temps_scope.is_some()
+            && this.fixed_temps_scope == temp_lifetime.temp_lifetime;
         let temp = if deduplicate_temps && let Some(temp_index) = this.fixed_temps.get(&expr_id) {
             *temp_index
         } else {
@@ -76,7 +75,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     LocalInfo::BlockTailTemp(tail_info)
                 }
 
-                _ if let Some(Scope { data: ScopeData::IfThenRescope, id }) = temp_lifetime => {
+                _ if let Some(Scope { data: ScopeData::IfThenRescope, id }) =
+                    temp_lifetime.temp_lifetime =>
+                {
                     LocalInfo::IfThenRescopeTemp {
                         if_then: HirId { owner: this.hir_id.owner, local_id: id },
                     }
@@ -117,7 +118,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 // Anything with a shorter lifetime (e.g the `&foo()` in
                 // `bar(&foo())` or anything within a block will keep the
                 // regular drops just like runtime code.
-                if let Some(temp_lifetime) = temp_lifetime {
+                if let Some(temp_lifetime) = temp_lifetime.temp_lifetime {
                     this.schedule_drop(expr_span, temp_lifetime, temp, DropKind::Storage);
                 }
             }
@@ -125,10 +126,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         block = this.expr_into_dest(temp_place, block, expr_id).into_block();
 
-        if let Some(temp_lifetime) = temp_lifetime {
+        if let Some(temp_lifetime) = temp_lifetime.temp_lifetime {
             this.schedule_drop(expr_span, temp_lifetime, temp, DropKind::Value);
         }
 
+        if let Some(backwards_incompatible) = temp_lifetime.backwards_incompatible {
+            this.schedule_backwards_incompatible_drop(expr_span, backwards_incompatible, temp);
+        }
+
         block.and(temp)
     }
 }
diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs
index 0dec56d21ae..bebb44faba6 100644
--- a/compiler/rustc_mir_build/src/build/expr/into.rs
+++ b/compiler/rustc_mir_build/src/build/expr/into.rs
@@ -139,7 +139,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 // (#66975) Source could be a const of type `!`, so has to
                 // exist in the generated MIR.
                 unpack!(
-                    block = this.as_temp(block, Some(this.local_scope()), source, Mutability::Mut)
+                    block =
+                        this.as_temp(block, this.local_temp_lifetime(), source, Mutability::Mut)
                 );
 
                 // This is an optimization. If the expression was a call then we already have an
@@ -321,7 +322,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 let is_union = adt_def.is_union();
                 let active_field_index = is_union.then(|| fields[0].name);
 
-                let scope = this.local_scope();
+                let scope = this.local_temp_lifetime();
 
                 // first process the set of fields that were provided
                 // (evaluating them in order given by user)
@@ -333,7 +334,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                             unpack!(
                                 block = this.as_operand(
                                     block,
-                                    Some(scope),
+                                    scope,
                                     f.expr,
                                     LocalInfo::AggregateTemp,
                                     NeedsTemporary::Maybe,
@@ -548,15 +549,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             }
 
             ExprKind::Yield { value } => {
-                let scope = this.local_scope();
+                let scope = this.local_temp_lifetime();
                 let value = unpack!(
-                    block = this.as_operand(
-                        block,
-                        Some(scope),
-                        value,
-                        LocalInfo::Boring,
-                        NeedsTemporary::No
-                    )
+                    block =
+                        this.as_operand(block, scope, value, LocalInfo::Boring, NeedsTemporary::No)
                 );
                 let resume = this.cfg.start_new_block();
                 this.cfg.terminate(block, source_info, TerminatorKind::Yield {
diff --git a/compiler/rustc_mir_build/src/build/expr/stmt.rs b/compiler/rustc_mir_build/src/build/expr/stmt.rs
index 02ca12028d3..15ee6dd014c 100644
--- a/compiler/rustc_mir_build/src/build/expr/stmt.rs
+++ b/compiler/rustc_mir_build/src/build/expr/stmt.rs
@@ -172,8 +172,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     None
                 };
 
-                let temp =
-                    unpack!(block = this.as_temp(block, statement_scope, expr_id, Mutability::Not));
+                let temp = unpack!(
+                    block = this.as_temp(
+                        block,
+                        TempLifetime {
+                            temp_lifetime: statement_scope,
+                            backwards_incompatible: None
+                        },
+                        expr_id,
+                        Mutability::Not
+                    )
+                );
 
                 if let Some(span) = adjusted_span {
                     this.local_decls[temp].source_info.span = span;
diff --git a/compiler/rustc_mir_build/src/build/matches/mod.rs b/compiler/rustc_mir_build/src/build/matches/mod.rs
index 9f81e1052d6..5791460a6b1 100644
--- a/compiler/rustc_mir_build/src/build/matches/mod.rs
+++ b/compiler/rustc_mir_build/src/build/matches/mod.rs
@@ -202,8 +202,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 // Increment the decision depth, in case we encounter boolean expressions
                 // further down.
                 this.mcdc_increment_depth_if_enabled();
-                let place =
-                    unpack!(block = this.as_temp(block, Some(temp_scope), expr_id, mutability));
+                let place = unpack!(
+                    block = this.as_temp(
+                        block,
+                        TempLifetime {
+                            temp_lifetime: Some(temp_scope),
+                            backwards_incompatible: None
+                        },
+                        expr_id,
+                        mutability
+                    )
+                );
                 this.mcdc_decrement_depth_if_enabled();
 
                 let operand = Operand::Move(Place::from(place));
diff --git a/compiler/rustc_mir_build/src/build/mod.rs b/compiler/rustc_mir_build/src/build/mod.rs
index cf8dc597b7b..3317f3b7f8a 100644
--- a/compiler/rustc_mir_build/src/build/mod.rs
+++ b/compiler/rustc_mir_build/src/build/mod.rs
@@ -148,6 +148,10 @@ struct BlockContext(Vec<BlockFrame>);
 
 struct Builder<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
+    // FIXME(@lcnr): Why does this use an `infcx`, there should be
+    // no shared type inference going on here. I feel like it would
+    // clearer to manually construct one where necessary or to provide
+    // a nice API for non-type inference trait system checks.
     infcx: InferCtxt<'tcx>,
     region_scope_tree: &'tcx region::ScopeTree,
     param_env: ty::ParamEnv<'tcx>,
diff --git a/compiler/rustc_mir_build/src/build/scope.rs b/compiler/rustc_mir_build/src/build/scope.rs
index e63fbeeac66..636e47b7ad2 100644
--- a/compiler/rustc_mir_build/src/build/scope.rs
+++ b/compiler/rustc_mir_build/src/build/scope.rs
@@ -89,7 +89,7 @@ use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::middle::region;
 use rustc_middle::mir::*;
 use rustc_middle::thir::{ExprId, LintLevel};
-use rustc_middle::{bug, span_bug};
+use rustc_middle::{bug, span_bug, ty};
 use rustc_session::lint::Level;
 use rustc_span::source_map::Spanned;
 use rustc_span::{DUMMY_SP, Span};
@@ -151,6 +151,9 @@ struct DropData {
 
     /// Whether this is a value Drop or a StorageDead.
     kind: DropKind,
+
+    /// Whether this is a backwards-incompatible drop lint
+    backwards_incompatible_lint: bool,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -274,8 +277,12 @@ impl DropTree {
         // represents the block in the tree that should be jumped to once all
         // of the required drops have been performed.
         let fake_source_info = SourceInfo::outermost(DUMMY_SP);
-        let fake_data =
-            DropData { source_info: fake_source_info, local: Local::MAX, kind: DropKind::Storage };
+        let fake_data = DropData {
+            source_info: fake_source_info,
+            local: Local::MAX,
+            kind: DropKind::Storage,
+            backwards_incompatible_lint: false,
+        };
         let drops = IndexVec::from_raw(vec![DropNode { data: fake_data, next: DropIdx::MAX }]);
         Self { drops, entry_points: Vec::new(), existing_drops_map: FxHashMap::default() }
     }
@@ -763,7 +770,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     let local =
                         place.as_local().unwrap_or_else(|| bug!("projection in tail call args"));
 
-                    Some(DropData { source_info, local, kind: DropKind::Value })
+                    Some(DropData {
+                        source_info,
+                        local,
+                        kind: DropKind::Value,
+                        backwards_incompatible_lint: false,
+                    })
                 }
                 Operand::Constant(_) => None,
             })
@@ -1019,9 +1031,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 if local.index() <= self.arg_count {
                     span_bug!(
                         span,
-                        "`schedule_drop` called with local {:?} and arg_count {}",
+                        "`schedule_drop` called with body argument {:?} \
+                        but its storage does not require a drop",
                         local,
-                        self.arg_count,
                     )
                 }
                 false
@@ -1089,6 +1101,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     source_info: SourceInfo { span: scope_end, scope: scope.source_scope },
                     local,
                     kind: drop_kind,
+                    backwards_incompatible_lint: false,
                 });
 
                 return;
@@ -1098,6 +1111,45 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         span_bug!(span, "region scope {:?} not in scope to drop {:?}", region_scope, local);
     }
 
+    /// Schedule emission of a backwards incompatible drop lint hint.
+    /// Applicable only to temporary values for now.
+    pub(crate) fn schedule_backwards_incompatible_drop(
+        &mut self,
+        span: Span,
+        region_scope: region::Scope,
+        local: Local,
+    ) {
+        if !self.local_decls[local].ty.has_significant_drop(self.tcx, ty::TypingEnv {
+            typing_mode: ty::TypingMode::non_body_analysis(),
+            param_env: self.param_env,
+        }) {
+            return;
+        }
+        for scope in self.scopes.scopes.iter_mut().rev() {
+            // Since we are inserting linting MIR statement, we have to invalidate the caches
+            scope.invalidate_cache();
+            if scope.region_scope == region_scope {
+                let region_scope_span = region_scope.span(self.tcx, self.region_scope_tree);
+                let scope_end = self.tcx.sess.source_map().end_point(region_scope_span);
+
+                scope.drops.push(DropData {
+                    source_info: SourceInfo { span: scope_end, scope: scope.source_scope },
+                    local,
+                    kind: DropKind::Value,
+                    backwards_incompatible_lint: true,
+                });
+
+                return;
+            }
+        }
+        span_bug!(
+            span,
+            "region scope {:?} not in scope to drop {:?} for linting",
+            region_scope,
+            local
+        );
+    }
+
     /// Indicates that the "local operand" stored in `local` is
     /// *moved* at some point during execution (see `local_scope` for
     /// more information about what a "local operand" is -- in short,
@@ -1378,16 +1430,25 @@ fn build_scope_drops<'tcx>(
                     continue;
                 }
 
-                unwind_drops.add_entry_point(block, unwind_to);
-
-                let next = cfg.start_new_block();
-                cfg.terminate(block, source_info, TerminatorKind::Drop {
-                    place: local.into(),
-                    target: next,
-                    unwind: UnwindAction::Continue,
-                    replace: false,
-                });
-                block = next;
+                if drop_data.backwards_incompatible_lint {
+                    cfg.push(block, Statement {
+                        source_info,
+                        kind: StatementKind::BackwardIncompatibleDropHint {
+                            place: Box::new(local.into()),
+                            reason: BackwardIncompatibleDropReason::Edition2024,
+                        },
+                    });
+                } else {
+                    unwind_drops.add_entry_point(block, unwind_to);
+                    let next = cfg.start_new_block();
+                    cfg.terminate(block, source_info, TerminatorKind::Drop {
+                        place: local.into(),
+                        target: next,
+                        unwind: UnwindAction::Continue,
+                        replace: false,
+                    });
+                    block = next;
+                }
             }
             DropKind::Storage => {
                 if storage_dead_on_unwind {
diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs
index a042da0eb4a..66ea0a6e836 100644
--- a/compiler/rustc_mir_build/src/check_unsafety.rs
+++ b/compiler/rustc_mir_build/src/check_unsafety.rs
@@ -11,7 +11,7 @@ use rustc_middle::span_bug;
 use rustc_middle::thir::visit::Visitor;
 use rustc_middle::thir::*;
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::lint::Level;
 use rustc_session::lint::builtin::{DEPRECATED_SAFE_2024, UNSAFE_OP_IN_UNSAFE_FN, UNUSED_UNSAFE};
 use rustc_span::def_id::{DefId, LocalDefId};
@@ -37,7 +37,7 @@ struct UnsafetyVisitor<'a, 'tcx> {
     /// of the LHS and the span of the assignment expression.
     assignment_info: Option<Ty<'tcx>>,
     in_union_destructure: bool,
-    param_env: ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     inside_adt: bool,
     warnings: &'a mut Vec<UnusedUnsafeWarning>,
 
@@ -213,7 +213,7 @@ impl<'tcx> UnsafetyVisitor<'_, 'tcx> {
                 body_target_features: self.body_target_features,
                 assignment_info: self.assignment_info,
                 in_union_destructure: false,
-                param_env: self.param_env,
+                typing_env: self.typing_env,
                 inside_adt: false,
                 warnings: self.warnings,
                 suggest_unsafe_block: self.suggest_unsafe_block,
@@ -370,7 +370,7 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
                     };
                     match rm {
                         Mutability::Not => {
-                            if !ty.is_freeze(self.tcx, self.param_env) {
+                            if !ty.is_freeze(self.tcx, self.typing_env) {
                                 self.requires_unsafe(pat.span, BorrowOfLayoutConstrainedField);
                             }
                         }
@@ -570,9 +570,7 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
                     && adt_def.is_union()
                 {
                     if let Some(assigned_ty) = self.assignment_info {
-                        if assigned_ty
-                            .needs_drop(self.tcx, ty::TypingEnv::from_param_env(self.param_env))
-                        {
+                        if assigned_ty.needs_drop(self.tcx, self.typing_env) {
                             // This would be unsafe, but should be outright impossible since we
                             // reject such unions.
                             assert!(
@@ -612,7 +610,7 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
                 if visitor.found {
                     match borrow_kind {
                         BorrowKind::Fake(_) | BorrowKind::Shared
-                            if !self.thir[arg].ty.is_freeze(self.tcx, self.param_env) =>
+                            if !self.thir[arg].ty.is_freeze(self.tcx, self.typing_env) =>
                         {
                             self.requires_unsafe(expr.span, BorrowOfLayoutConstrainedField)
                         }
@@ -1030,7 +1028,8 @@ pub(crate) fn check_unsafety(tcx: TyCtxt<'_>, def: LocalDefId) {
         body_target_features,
         assignment_info: None,
         in_union_destructure: false,
-        param_env: tcx.param_env(def),
+        // FIXME(#132279): we're clearly in a body here.
+        typing_env: ty::TypingEnv::non_body_analysis(tcx, def),
         inside_adt: false,
         warnings: &mut warnings,
         suggest_unsafe_block: true,
diff --git a/compiler/rustc_mir_build/src/lints.rs b/compiler/rustc_mir_build/src/lints.rs
index a1b75c22c4d..5cf33868ade 100644
--- a/compiler/rustc_mir_build/src/lints.rs
+++ b/compiler/rustc_mir_build/src/lints.rs
@@ -132,21 +132,16 @@ impl<'tcx> TerminatorClassifier<'tcx> for CallRecursion<'tcx> {
             return false;
         }
         let caller = body.source.def_id();
-        let param_env = tcx.param_env(caller);
+        let typing_env = body.typing_env(tcx);
 
         let func_ty = func.ty(body, tcx);
         if let ty::FnDef(callee, args) = *func_ty.kind() {
-            let Ok(normalized_args) =
-                tcx.try_normalize_erasing_regions(ty::TypingEnv::from_param_env(param_env), args)
-            else {
+            let Ok(normalized_args) = tcx.try_normalize_erasing_regions(typing_env, args) else {
                 return false;
             };
-            let (callee, call_args) = if let Ok(Some(instance)) = Instance::try_resolve(
-                tcx,
-                ty::TypingEnv::from_param_env(param_env),
-                callee,
-                normalized_args,
-            ) {
+            let (callee, call_args) = if let Ok(Some(instance)) =
+                Instance::try_resolve(tcx, typing_env, callee, normalized_args)
+            {
                 (instance.def_id(), instance.args)
             } else {
                 (callee, normalized_args)
diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs
index 198fa4ffb7a..47b7f332951 100644
--- a/compiler/rustc_mir_build/src/thir/cx/expr.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs
@@ -23,7 +23,6 @@ use tracing::{debug, info, instrument, trace};
 
 use crate::errors;
 use crate::thir::cx::Cx;
-use crate::thir::cx::region::Scope;
 use crate::thir::util::UserAnnotatedTyHelpers;
 
 impl<'tcx> Cx<'tcx> {
@@ -240,7 +239,7 @@ impl<'tcx> Cx<'tcx> {
     fn mirror_expr_cast(
         &mut self,
         source: &'tcx hir::Expr<'tcx>,
-        temp_lifetime: Option<Scope>,
+        temp_lifetime: TempLifetime,
         span: Span,
     ) -> ExprKind<'tcx> {
         let tcx = self.tcx;
@@ -325,7 +324,7 @@ impl<'tcx> Cx<'tcx> {
     fn make_mirror_unadjusted(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Expr<'tcx> {
         let tcx = self.tcx;
         let expr_ty = self.typeck_results().expr_ty(expr);
-        let temp_lifetime =
+        let (temp_lifetime, backwards_incompatible) =
             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
 
         let kind = match expr.kind {
@@ -361,7 +360,7 @@ impl<'tcx> Cx<'tcx> {
                     let arg_tys = args.iter().map(|e| self.typeck_results().expr_ty_adjusted(e));
                     let tupled_args = Expr {
                         ty: Ty::new_tup_from_iter(tcx, arg_tys),
-                        temp_lifetime,
+                        temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
                         span: expr.span,
                         kind: ExprKind::Tuple { fields: self.mirror_exprs(args) },
                     };
@@ -391,7 +390,10 @@ impl<'tcx> Cx<'tcx> {
                                 && let [value] = args
                             {
                                 return Expr {
-                                    temp_lifetime,
+                                    temp_lifetime: TempLifetime {
+                                        temp_lifetime,
+                                        backwards_incompatible,
+                                    },
                                     ty: expr_ty,
                                     span: expr.span,
                                     kind: ExprKind::Box { value: self.mirror_expr(value) },
@@ -811,13 +813,13 @@ impl<'tcx> Cx<'tcx> {
             },
             hir::ExprKind::Loop(body, ..) => {
                 let block_ty = self.typeck_results().node_type(body.hir_id);
-                let temp_lifetime = self
+                let (temp_lifetime, backwards_incompatible) = self
                     .rvalue_scopes
                     .temporary_scope(self.region_scope_tree, body.hir_id.local_id);
                 let block = self.mirror_block(body);
                 let body = self.thir.exprs.push(Expr {
                     ty: block_ty,
-                    temp_lifetime,
+                    temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
                     span: self.thir[block].span,
                     kind: ExprKind::Block { block },
                 });
@@ -838,13 +840,17 @@ impl<'tcx> Cx<'tcx> {
                     expr, cast_ty.hir_id, user_ty,
                 );
 
-                let cast = self.mirror_expr_cast(source, temp_lifetime, expr.span);
+                let cast = self.mirror_expr_cast(
+                    source,
+                    TempLifetime { temp_lifetime, backwards_incompatible },
+                    expr.span,
+                );
 
                 if let Some(user_ty) = user_ty {
                     // NOTE: Creating a new Expr and wrapping a Cast inside of it may be
                     //       inefficient, revisit this when performance becomes an issue.
                     let cast_expr = self.thir.exprs.push(Expr {
-                        temp_lifetime,
+                        temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
                         ty: expr_ty,
                         span: expr.span,
                         kind: cast,
@@ -887,7 +893,12 @@ impl<'tcx> Cx<'tcx> {
             hir::ExprKind::Err(_) => unreachable!("cannot lower a `hir::ExprKind::Err` to THIR"),
         };
 
-        Expr { temp_lifetime, ty: expr_ty, span: expr.span, kind }
+        Expr {
+            temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
+            ty: expr_ty,
+            span: expr.span,
+            kind,
+        }
     }
 
     fn user_args_applied_to_res(
@@ -931,7 +942,7 @@ impl<'tcx> Cx<'tcx> {
         span: Span,
         overloaded_callee: Option<Ty<'tcx>>,
     ) -> Expr<'tcx> {
-        let temp_lifetime =
+        let (temp_lifetime, backwards_incompatible) =
             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
         let (ty, user_ty) = match overloaded_callee {
             Some(fn_def) => (fn_def, None),
@@ -952,7 +963,12 @@ impl<'tcx> Cx<'tcx> {
                 )
             }
         };
-        Expr { temp_lifetime, ty, span, kind: ExprKind::ZstLiteral { user_ty } }
+        Expr {
+            temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
+            ty,
+            span,
+            kind: ExprKind::ZstLiteral { user_ty },
+        }
     }
 
     fn convert_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) -> ArmId {
@@ -1025,7 +1041,7 @@ impl<'tcx> Cx<'tcx> {
             Res::Def(DefKind::Static { .. }, id) => {
                 // this is &raw for extern static or static mut, and & for other statics
                 let ty = self.tcx.static_ptr_ty(id, self.typing_env());
-                let temp_lifetime = self
+                let (temp_lifetime, backwards_incompatible) = self
                     .rvalue_scopes
                     .temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
                 let kind = if self.tcx.is_thread_local_static(id) {
@@ -1035,7 +1051,12 @@ impl<'tcx> Cx<'tcx> {
                     ExprKind::StaticRef { alloc_id, ty, def_id: id }
                 };
                 ExprKind::Deref {
-                    arg: self.thir.exprs.push(Expr { ty, temp_lifetime, span: expr.span, kind }),
+                    arg: self.thir.exprs.push(Expr {
+                        ty,
+                        temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
+                        span: expr.span,
+                        kind,
+                    }),
                 }
             }
 
@@ -1106,13 +1127,13 @@ impl<'tcx> Cx<'tcx> {
 
         // construct the complete expression `foo()` for the overloaded call,
         // which will yield the &T type
-        let temp_lifetime =
+        let (temp_lifetime, backwards_incompatible) =
             self.rvalue_scopes.temporary_scope(self.region_scope_tree, expr.hir_id.local_id);
         let fun = self.method_callee(expr, span, overloaded_callee);
         let fun = self.thir.exprs.push(fun);
         let fun_ty = self.thir[fun].ty;
         let ref_expr = self.thir.exprs.push(Expr {
-            temp_lifetime,
+            temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
             ty: ref_ty,
             span,
             kind: ExprKind::Call { ty: fun_ty, fun, args, from_hir_call: false, fn_span: span },
@@ -1127,7 +1148,7 @@ impl<'tcx> Cx<'tcx> {
         closure_expr: &'tcx hir::Expr<'tcx>,
         place: HirPlace<'tcx>,
     ) -> Expr<'tcx> {
-        let temp_lifetime = self
+        let (temp_lifetime, backwards_incompatible) = self
             .rvalue_scopes
             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
         let var_ty = place.base_ty;
@@ -1143,7 +1164,7 @@ impl<'tcx> Cx<'tcx> {
         };
 
         let mut captured_place_expr = Expr {
-            temp_lifetime,
+            temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
             ty: var_ty,
             span: closure_expr.span,
             kind: self.convert_var(var_hir_id),
@@ -1168,8 +1189,12 @@ impl<'tcx> Cx<'tcx> {
                 }
             };
 
-            captured_place_expr =
-                Expr { temp_lifetime, ty: proj.ty, span: closure_expr.span, kind };
+            captured_place_expr = Expr {
+                temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
+                ty: proj.ty,
+                span: closure_expr.span,
+                kind,
+            };
         }
 
         captured_place_expr
@@ -1184,7 +1209,7 @@ impl<'tcx> Cx<'tcx> {
         let upvar_capture = captured_place.info.capture_kind;
         let captured_place_expr =
             self.convert_captured_hir_place(closure_expr, captured_place.place.clone());
-        let temp_lifetime = self
+        let (temp_lifetime, backwards_incompatible) = self
             .rvalue_scopes
             .temporary_scope(self.region_scope_tree, closure_expr.hir_id.local_id);
 
@@ -1201,7 +1226,7 @@ impl<'tcx> Cx<'tcx> {
                     }
                 };
                 Expr {
-                    temp_lifetime,
+                    temp_lifetime: TempLifetime { temp_lifetime, backwards_incompatible },
                     ty: upvar_ty,
                     span: closure_expr.span,
                     kind: ExprKind::Borrow {
diff --git a/compiler/rustc_mir_build/src/thir/cx/mod.rs b/compiler/rustc_mir_build/src/thir/cx/mod.rs
index dfc180f5261..d47f7154c4b 100644
--- a/compiler/rustc_mir_build/src/thir/cx/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/mod.rs
@@ -123,7 +123,7 @@ impl<'tcx> Cx<'tcx> {
 
     #[instrument(level = "debug", skip(self))]
     fn pattern_from_hir(&mut self, p: &'tcx hir::Pat<'tcx>) -> Box<Pat<'tcx>> {
-        pat_from_hir(self.tcx, self.param_env, self.typeck_results(), p)
+        pat_from_hir(self.tcx, self.typing_env(), self.typeck_results(), p)
     }
 
     fn closure_env_param(&self, owner_def: LocalDefId, expr_id: HirId) -> Option<Param<'tcx>> {
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index c7dacbc6789..27920008c80 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -7,6 +7,7 @@ use rustc_errors::{Applicability, ErrorGuaranteed, MultiSpan, struct_span_code_e
 use rustc_hir::def::*;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::{self as hir, BindingMode, ByRef, HirId};
+use rustc_infer::traits::Reveal;
 use rustc_middle::bug;
 use rustc_middle::middle::limits::get_limit_size;
 use rustc_middle::thir::visit::Visitor;
@@ -191,6 +192,15 @@ impl<'p, 'tcx> Visitor<'p, 'tcx> for MatchVisitor<'p, 'tcx> {
 }
 
 impl<'p, 'tcx> MatchVisitor<'p, 'tcx> {
+    fn typing_env(&self) -> ty::TypingEnv<'tcx> {
+        // FIXME(#132279): We're in a body, should handle opaques.
+        debug_assert_eq!(self.param_env.reveal(), Reveal::UserFacing);
+        ty::TypingEnv {
+            typing_mode: ty::TypingMode::non_body_analysis(),
+            param_env: self.param_env,
+        }
+    }
+
     #[instrument(level = "trace", skip(self, f))]
     fn with_let_source(&mut self, let_source: LetSource, f: impl FnOnce(&mut Self)) {
         let old_let_source = self.let_source;
@@ -775,7 +785,7 @@ fn check_borrow_conflicts_in_at_patterns<'tcx>(cx: &MatchVisitor<'_, 'tcx>, pat:
         return;
     };
 
-    let is_binding_by_move = |ty: Ty<'tcx>| !ty.is_copy_modulo_regions(cx.tcx, cx.param_env);
+    let is_binding_by_move = |ty: Ty<'tcx>| !ty.is_copy_modulo_regions(cx.tcx, cx.typing_env());
 
     let sess = cx.tcx.sess;
 
diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
index 6b462198db6..a40134e44e7 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
@@ -2,11 +2,11 @@ use rustc_abi::{FieldIdx, VariantIdx};
 use rustc_apfloat::Float;
 use rustc_hir as hir;
 use rustc_index::Idx;
-use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
+use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::Obligation;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::thir::{FieldPat, Pat, PatKind};
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, TypingMode, ValTree};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, ValTree};
 use rustc_middle::{mir, span_bug};
 use rustc_span::Span;
 use rustc_trait_selection::traits::ObligationCause;
@@ -35,10 +35,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
         id: hir::HirId,
         span: Span,
     ) -> Box<Pat<'tcx>> {
-        // FIXME(#132279): We likely want to be able to reveal the hidden types
-        // of opaques defined in this function here.
-        let infcx = self.tcx.infer_ctxt().build(TypingMode::non_body_analysis());
-        let mut convert = ConstToPat::new(self, id, span, infcx);
+        let mut convert = ConstToPat::new(self, id, span);
 
         match c.kind() {
             ty::ConstKind::Unevaluated(uv) => convert.unevaluated_to_pat(uv, ty),
@@ -49,27 +46,20 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
 }
 
 struct ConstToPat<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     span: Span,
 
-    // inference context used for checking `T: Structural` bounds.
-    infcx: InferCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
-
     treat_byte_string_as_slice: bool,
 }
 
 impl<'tcx> ConstToPat<'tcx> {
-    fn new(
-        pat_ctxt: &PatCtxt<'_, 'tcx>,
-        id: hir::HirId,
-        span: Span,
-        infcx: InferCtxt<'tcx>,
-    ) -> Self {
+    fn new(pat_ctxt: &PatCtxt<'_, 'tcx>, id: hir::HirId, span: Span) -> Self {
         trace!(?pat_ctxt.typeck_results.hir_owner);
         ConstToPat {
+            tcx: pat_ctxt.tcx,
+            typing_env: pat_ctxt.typing_env,
             span,
-            infcx,
-            param_env: pat_ctxt.param_env,
             treat_byte_string_as_slice: pat_ctxt
                 .typeck_results
                 .treat_byte_string_as_slice
@@ -77,16 +67,8 @@ impl<'tcx> ConstToPat<'tcx> {
         }
     }
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
-        self.infcx.tcx
-    }
-
-    fn typing_env(&self) -> ty::TypingEnv<'tcx> {
-        self.infcx.typing_env(self.param_env)
-    }
-
     fn type_marked_structural(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_structural_eq_shallow(self.infcx.tcx)
+        ty.is_structural_eq_shallow(self.tcx)
     }
 
     fn unevaluated_to_pat(
@@ -105,22 +87,21 @@ impl<'tcx> ConstToPat<'tcx> {
         // FIXME: `const_eval_resolve_for_typeck` should probably just set the env to `Reveal::All`
         // instead of having this logic here
         let typing_env =
-            self.tcx().erase_regions(self.typing_env()).with_reveal_all_normalized(self.tcx());
-        let uv = self.tcx().erase_regions(uv);
+            self.tcx.erase_regions(self.typing_env).with_reveal_all_normalized(self.tcx);
+        let uv = self.tcx.erase_regions(uv);
 
         // try to resolve e.g. associated constants to their definition on an impl, and then
         // evaluate the const.
-        let valtree = match self.infcx.tcx.const_eval_resolve_for_typeck(typing_env, uv, self.span)
-        {
+        let valtree = match self.tcx.const_eval_resolve_for_typeck(typing_env, uv, self.span) {
             Ok(Ok(c)) => c,
             Err(ErrorHandled::Reported(_, _)) => {
                 // Let's tell the use where this failing const occurs.
-                let e = self.tcx().dcx().emit_err(CouldNotEvalConstPattern { span: self.span });
+                let e = self.tcx.dcx().emit_err(CouldNotEvalConstPattern { span: self.span });
                 return pat_from_kind(PatKind::Error(e));
             }
             Err(ErrorHandled::TooGeneric(_)) => {
                 let e = self
-                    .tcx()
+                    .tcx
                     .dcx()
                     .emit_err(ConstPatternDependsOnGenericParameter { span: self.span });
                 return pat_from_kind(PatKind::Error(e));
@@ -130,13 +111,13 @@ impl<'tcx> ConstToPat<'tcx> {
                 let e = match bad_ty.kind() {
                     ty::Adt(def, ..) => {
                         assert!(def.is_union());
-                        self.tcx().dcx().emit_err(UnionPattern { span: self.span })
+                        self.tcx.dcx().emit_err(UnionPattern { span: self.span })
                     }
                     ty::FnPtr(..) | ty::RawPtr(..) => {
-                        self.tcx().dcx().emit_err(PointerPattern { span: self.span })
+                        self.tcx.dcx().emit_err(PointerPattern { span: self.span })
                     }
                     _ => self
-                        .tcx()
+                        .tcx
                         .dcx()
                         .emit_err(InvalidPattern { span: self.span, non_sm_ty: bad_ty }),
                 };
@@ -151,7 +132,7 @@ impl<'tcx> ConstToPat<'tcx> {
             // Always check for `PartialEq` if we had no other errors yet.
             if !self.type_has_partial_eq_impl(ty) {
                 let err = TypeNotPartialEq { span: self.span, non_peq_ty: ty };
-                let e = self.tcx().dcx().emit_err(err);
+                let e = self.tcx.dcx().emit_err(err);
                 return pat_from_kind(PatKind::Error(e));
             }
         }
@@ -161,18 +142,19 @@ impl<'tcx> ConstToPat<'tcx> {
 
     #[instrument(level = "trace", skip(self), ret)]
     fn type_has_partial_eq_impl(&self, ty: Ty<'tcx>) -> bool {
-        let tcx = self.tcx();
+        let (infcx, param_env) = self.tcx.infer_ctxt().build_with_typing_env(self.typing_env);
         // double-check there even *is* a semantic `PartialEq` to dispatch to.
         //
         // (If there isn't, then we can safely issue a hard
         // error, because that's never worked, due to compiler
         // using `PartialEq::eq` in this scenario in the past.)
-        let partial_eq_trait_id = tcx.require_lang_item(hir::LangItem::PartialEq, Some(self.span));
+        let partial_eq_trait_id =
+            self.tcx.require_lang_item(hir::LangItem::PartialEq, Some(self.span));
         let partial_eq_obligation = Obligation::new(
-            tcx,
+            self.tcx,
             ObligationCause::dummy(),
-            self.param_env,
-            ty::TraitRef::new(tcx, partial_eq_trait_id, [ty, ty]),
+            param_env,
+            ty::TraitRef::new(self.tcx, partial_eq_trait_id, [ty, ty]),
         );
 
         // This *could* accept a type that isn't actually `PartialEq`, because region bounds get
@@ -181,7 +163,7 @@ impl<'tcx> ConstToPat<'tcx> {
         // `PartialEq` for some lifetime but *not* for `'static`? If this ever becomes a problem
         // we'll need to leave some sort of trace of this requirement in the MIR so that borrowck
         // can ensure that the type really implements `PartialEq`.
-        self.infcx.predicate_must_hold_modulo_regions(&partial_eq_obligation)
+        infcx.predicate_must_hold_modulo_regions(&partial_eq_obligation)
     }
 
     fn field_pats(
@@ -192,7 +174,7 @@ impl<'tcx> ConstToPat<'tcx> {
             .map(|(idx, (val, ty))| {
                 let field = FieldIdx::new(idx);
                 // Patterns can only use monomorphic types.
-                let ty = self.tcx().normalize_erasing_regions(self.typing_env(), ty);
+                let ty = self.tcx.normalize_erasing_regions(self.typing_env, ty);
                 FieldPat { field, pattern: self.valtree_to_pat(val, ty) }
             })
             .collect()
@@ -202,14 +184,12 @@ impl<'tcx> ConstToPat<'tcx> {
     #[instrument(skip(self), level = "debug")]
     fn valtree_to_pat(&self, cv: ValTree<'tcx>, ty: Ty<'tcx>) -> Box<Pat<'tcx>> {
         let span = self.span;
-        let tcx = self.tcx();
-        let param_env = self.param_env;
-
+        let tcx = self.tcx;
         let kind = match ty.kind() {
             ty::Adt(adt_def, _) if !self.type_marked_structural(ty) => {
                 // Extremely important check for all ADTs! Make sure they opted-in to be used in
                 // patterns.
-                debug!("adt_def {:?} has !type_marked_structural for cv.ty: {:?}", adt_def, ty,);
+                debug!("adt_def {:?} has !type_marked_structural for cv.ty: {:?}", adt_def, ty);
                 let err = TypeNotStructural { span, non_sm_ty: ty };
                 let e = tcx.dcx().emit_err(err);
                 // We errored. Signal that in the pattern, so that follow up errors can be silenced.
@@ -227,7 +207,7 @@ impl<'tcx> ConstToPat<'tcx> {
                             adt_def.variants()[variant_index]
                                 .fields
                                 .iter()
-                                .map(|field| field.ty(self.tcx(), args)),
+                                .map(|field| field.ty(self.tcx, args)),
                         ),
                     ),
                 }
@@ -235,14 +215,9 @@ impl<'tcx> ConstToPat<'tcx> {
             ty::Adt(def, args) => {
                 assert!(!def.is_union()); // Valtree construction would never succeed for unions.
                 PatKind::Leaf {
-                    subpatterns: self.field_pats(
-                        cv.unwrap_branch().iter().copied().zip(
-                            def.non_enum_variant()
-                                .fields
-                                .iter()
-                                .map(|field| field.ty(self.tcx(), args)),
-                        ),
-                    ),
+                    subpatterns: self.field_pats(cv.unwrap_branch().iter().copied().zip(
+                        def.non_enum_variant().fields.iter().map(|field| field.ty(self.tcx, args)),
+                    )),
                 }
             }
             ty::Tuple(fields) => PatKind::Leaf {
@@ -276,7 +251,7 @@ impl<'tcx> ConstToPat<'tcx> {
                 // convert the dereferenced constant to a pattern that is the sub-pattern of the
                 // deref pattern.
                 _ => {
-                    if !pointee_ty.is_sized(tcx, param_env) && !pointee_ty.is_slice() {
+                    if !pointee_ty.is_sized(tcx, self.typing_env) && !pointee_ty.is_slice() {
                         let err = UnsizedPattern { span, non_sm_ty: *pointee_ty };
                         let e = tcx.dcx().emit_err(err);
                         // We errored. Signal that in the pattern, so that follow up errors can be silenced.
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
index 2719070e28d..08c6b4abd3b 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
@@ -30,7 +30,7 @@ use crate::thir::util::UserAnnotatedTyHelpers;
 
 struct PatCtxt<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     typeck_results: &'a ty::TypeckResults<'tcx>,
 
     /// Used by the Rust 2024 migration lint.
@@ -39,13 +39,13 @@ struct PatCtxt<'a, 'tcx> {
 
 pub(super) fn pat_from_hir<'a, 'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     typeck_results: &'a ty::TypeckResults<'tcx>,
     pat: &'tcx hir::Pat<'tcx>,
 ) -> Box<Pat<'tcx>> {
     let mut pcx = PatCtxt {
         tcx,
-        param_env,
+        typing_env,
         typeck_results,
         rust_2024_migration_suggestion: typeck_results
             .rust_2024_migration_desugared_pats()
@@ -251,7 +251,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
         let lo = lo.unwrap_or(PatRangeBoundary::NegInfinity);
         let hi = hi.unwrap_or(PatRangeBoundary::PosInfinity);
 
-        let cmp = lo.compare_with(hi, ty, self.tcx, ty::TypingEnv::from_param_env(self.param_env));
+        let cmp = lo.compare_with(hi, ty, self.tcx, self.typing_env);
         let mut kind = PatKind::Range(Box::new(PatRange { lo, hi, end, ty }));
         match (end, cmp) {
             // `x..y` where `x < y`.
diff --git a/compiler/rustc_mir_dataflow/src/impls/liveness.rs b/compiler/rustc_mir_dataflow/src/impls/liveness.rs
index e06c1f2bb49..fd7254a0210 100644
--- a/compiler/rustc_mir_dataflow/src/impls/liveness.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/liveness.rs
@@ -253,6 +253,7 @@ impl<'a, 'tcx> Analysis<'tcx> for MaybeTransitiveLiveLocals<'a> {
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
             | StatementKind::ConstEvalCounter
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => None,
         };
         if let Some(destination) = destination {
diff --git a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs
index c5fd2a631ff..576289e228a 100644
--- a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs
@@ -157,6 +157,7 @@ impl<'tcx> Analysis<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
             | StatementKind::Nop
             | StatementKind::Retag(..)
             | StatementKind::Intrinsic(..)
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::StorageLive(..) => {}
         }
     }
diff --git a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
index fd8e403ebc2..0880364bfca 100644
--- a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
+++ b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
@@ -385,6 +385,7 @@ impl<'a, 'tcx, F: Fn(Ty<'tcx>) -> bool> MoveDataBuilder<'a, 'tcx, F> {
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
             | StatementKind::ConstEvalCounter
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_mir_transform/messages.ftl b/compiler/rustc_mir_transform/messages.ftl
index 9bbfae17fd9..d00bfc66a6a 100644
--- a/compiler/rustc_mir_transform/messages.ftl
+++ b/compiler/rustc_mir_transform/messages.ftl
@@ -25,6 +25,31 @@ mir_transform_must_not_suspend = {$pre}`{$def_path}`{$post} held across a suspen
     .help = consider using a block (`{"{ ... }"}`) to shrink the value's scope, ending before the suspend point
 mir_transform_operation_will_panic = this operation will panic at runtime
 
+mir_transform_tail_expr_drop_order = relative drop order changing in Rust 2024
+    .temporaries = in Rust 2024, this temporary value will be dropped first
+    .observers = in Rust 2024, this local variable or temporary value will be dropped second
+    .note_dtors =
+        dropping the temporary value runs this custom `Drop` impl, which we could not prove to be side-effect free
+    .note_observer_dtors =
+        dropping the local runs this custom `Drop` impl, which we could not prove to be side-effect free
+    .drop_location =
+        now the temporary value is dropped here, before the local variables in the block or statement
+    .note_epilogue = most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
+    .label_local_epilogue = {$is_dropped_first_edition_2024 ->
+        [true] up until Edition 2021 `{$name}` is dropped last but will be dropped earlier in Edition 2024
+        *[false] `{$name}` will be dropped later as of Edition 2024
+    }
+
+mir_transform_tail_expr_dtor = {$dtor_kind ->
+    [dyn] `{$name}` may invoke a custom destructor because it contains a trait object
+    *[concrete] `{$name}` invokes this custom destructor
+    }
+
+mir_transform_tail_expr_local = {$is_generated_name ->
+        [true] this value will be stored in a temporary; let us call it `{$name}`
+        *[false] `{$name}` calls a custom destructor
+    }
+
 mir_transform_unaligned_packed_ref = reference to packed field is unaligned
     .note = packed structs are only aligned by one byte, and many modern architectures penalize unaligned field accesses
     .note_ub = creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
diff --git a/compiler/rustc_mir_transform/src/check_alignment.rs b/compiler/rustc_mir_transform/src/check_alignment.rs
index a9600f77c0b..1b7c89fd251 100644
--- a/compiler/rustc_mir_transform/src/check_alignment.rs
+++ b/compiler/rustc_mir_transform/src/check_alignment.rs
@@ -3,7 +3,7 @@ use rustc_index::IndexVec;
 use rustc_middle::mir::interpret::Scalar;
 use rustc_middle::mir::visit::{MutatingUseContext, NonMutatingUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::*;
-use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::Session;
 use tracing::{debug, trace};
 
@@ -25,9 +25,9 @@ impl<'tcx> crate::MirPass<'tcx> for CheckAlignment {
             return;
         }
 
+        let typing_env = body.typing_env(tcx);
         let basic_blocks = body.basic_blocks.as_mut();
         let local_decls = &mut body.local_decls;
-        let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
 
         // This pass inserts new blocks. Each insertion changes the Location for all
         // statements/blocks after. Iterating or visiting the MIR in order would require updating
@@ -41,7 +41,7 @@ impl<'tcx> crate::MirPass<'tcx> for CheckAlignment {
                 let source_info = statement.source_info;
 
                 let mut finder =
-                    PointerFinder { tcx, local_decls, param_env, pointers: Vec::new() };
+                    PointerFinder { tcx, local_decls, typing_env, pointers: Vec::new() };
                 finder.visit_statement(statement, location);
 
                 for (local, ty) in finder.pointers {
@@ -65,7 +65,7 @@ impl<'tcx> crate::MirPass<'tcx> for CheckAlignment {
 struct PointerFinder<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     local_decls: &'a mut LocalDecls<'tcx>,
-    param_env: ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     pointers: Vec<(Place<'tcx>, Ty<'tcx>)>,
 }
 
@@ -107,7 +107,7 @@ impl<'a, 'tcx> Visitor<'tcx> for PointerFinder<'a, 'tcx> {
         let pointee_ty =
             pointer_ty.builtin_deref(true).expect("no builtin_deref for an unsafe pointer");
         // Ideally we'd support this in the future, but for now we are limited to sized types.
-        if !pointee_ty.is_sized(self.tcx, self.param_env) {
+        if !pointee_ty.is_sized(self.tcx, self.typing_env) {
             debug!("Unsafe pointer, but pointee is not known to be sized: {:?}", pointer_ty);
             return;
         }
diff --git a/compiler/rustc_mir_transform/src/copy_prop.rs b/compiler/rustc_mir_transform/src/copy_prop.rs
index 7d6ae9843b1..9b3443d3209 100644
--- a/compiler/rustc_mir_transform/src/copy_prop.rs
+++ b/compiler/rustc_mir_transform/src/copy_prop.rs
@@ -28,8 +28,8 @@ impl<'tcx> crate::MirPass<'tcx> for CopyProp {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         debug!(def_id = ?body.source.def_id());
 
-        let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
-        let ssa = SsaLocals::new(tcx, body, param_env);
+        let typing_env = body.typing_env(tcx);
+        let ssa = SsaLocals::new(tcx, body, typing_env);
 
         let fully_moved = fully_moved_locals(&ssa, body);
         debug!(?fully_moved);
diff --git a/compiler/rustc_mir_transform/src/coroutine.rs b/compiler/rustc_mir_transform/src/coroutine.rs
index d38a1dd11dc..8295a806d71 100644
--- a/compiler/rustc_mir_transform/src/coroutine.rs
+++ b/compiler/rustc_mir_transform/src/coroutine.rs
@@ -1772,6 +1772,7 @@ impl<'tcx> Visitor<'tcx> for EnsureCoroutineFieldAssignmentsNeverAlias<'_> {
             | StatementKind::Coverage(..)
             | StatementKind::Intrinsic(..)
             | StatementKind::ConstEvalCounter
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => {}
         }
     }
diff --git a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs
index 875db23ce09..824d657e1fc 100644
--- a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs
+++ b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs
@@ -97,6 +97,7 @@ fn filtered_statement_span(statement: &Statement<'_>) -> Option<Span> {
         StatementKind::StorageLive(_)
         | StatementKind::StorageDead(_)
         | StatementKind::ConstEvalCounter
+        | StatementKind::BackwardIncompatibleDropHint { .. }
         | StatementKind::Nop => None,
 
         // FIXME(#78546): MIR InstrumentCoverage - Can the source_info.span for `FakeRead`
diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
index 500515bc3cc..d017202f48b 100644
--- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
+++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
@@ -149,7 +149,7 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
             map,
             tcx,
             local_decls: &body.local_decls,
-            ecx: InterpCx::new(tcx, DUMMY_SP, typing_env.param_env, DummyMachine),
+            ecx: InterpCx::new(tcx, DUMMY_SP, typing_env, DummyMachine),
             typing_env,
         }
     }
@@ -186,7 +186,8 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
             | StatementKind::FakeRead(..)
             | StatementKind::PlaceMention(..)
             | StatementKind::Coverage(..)
-            | StatementKind::AscribeUserType(..) => (),
+            | StatementKind::BackwardIncompatibleDropHint { .. }
+            | StatementKind::AscribeUserType(..) => {}
         }
     }
 
diff --git a/compiler/rustc_mir_transform/src/dead_store_elimination.rs b/compiler/rustc_mir_transform/src/dead_store_elimination.rs
index 2898f82e25c..0c75cdadc92 100644
--- a/compiler/rustc_mir_transform/src/dead_store_elimination.rs
+++ b/compiler/rustc_mir_transform/src/dead_store_elimination.rs
@@ -99,7 +99,8 @@ fn eliminate<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
                 | StatementKind::Intrinsic(_)
                 | StatementKind::ConstEvalCounter
                 | StatementKind::PlaceMention(_)
-                | StatementKind::Nop => (),
+                | StatementKind::BackwardIncompatibleDropHint { .. }
+                | StatementKind::Nop => {}
 
                 StatementKind::FakeRead(_) | StatementKind::AscribeUserType(_, _) => {
                     bug!("{:?} not found in this MIR phase!", statement.kind)
diff --git a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs
index db72ec522a2..67b215c7c9d 100644
--- a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs
+++ b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs
@@ -208,7 +208,7 @@ pub(super) fn deduced_param_attrs<'tcx>(
                     // blow-up in compile times: #113372
                     && tcx
                         .normalize_erasing_regions(typing_env, local_decl.ty)
-                        .is_freeze(tcx, typing_env.param_env),
+                        .is_freeze(tcx, typing_env),
             },
         ),
     );
diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs
index beeab0d4a66..9c74b2f0839 100644
--- a/compiler/rustc_mir_transform/src/dest_prop.rs
+++ b/compiler/rustc_mir_transform/src/dest_prop.rs
@@ -581,7 +581,7 @@ impl WriteInfo {
                     | Rvalue::RawPtr(_, _)
                     | Rvalue::Len(_)
                     | Rvalue::Discriminant(_)
-                    | Rvalue::CopyForDeref(_) => (),
+                    | Rvalue::CopyForDeref(_) => {}
                 }
             }
             // Retags are technically also reads, but reporting them as a write suffices
@@ -596,7 +596,8 @@ impl WriteInfo {
             | StatementKind::Coverage(_)
             | StatementKind::StorageLive(_)
             | StatementKind::StorageDead(_)
-            | StatementKind::PlaceMention(_) => (),
+            | StatementKind::BackwardIncompatibleDropHint { .. }
+            | StatementKind::PlaceMention(_) => {}
             StatementKind::FakeRead(_) | StatementKind::AscribeUserType(_, _) => {
                 bug!("{:?} not found in this MIR phase", statement)
             }
diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs
index 27fe0ad72e7..976f4a8e919 100644
--- a/compiler/rustc_mir_transform/src/gvn.rs
+++ b/compiler/rustc_mir_transform/src/gvn.rs
@@ -100,7 +100,7 @@ use rustc_middle::bug;
 use rustc_middle::mir::interpret::GlobalAlloc;
 use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
-use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::layout::{HasTypingEnv, LayoutOf};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::DUMMY_SP;
 use rustc_span::def_id::DefId;
@@ -120,12 +120,12 @@ impl<'tcx> crate::MirPass<'tcx> for GVN {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         debug!(def_id = ?body.source.def_id());
 
-        let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
-        let ssa = SsaLocals::new(tcx, body, param_env);
+        let typing_env = body.typing_env(tcx);
+        let ssa = SsaLocals::new(tcx, body, typing_env);
         // Clone dominators because we need them while mutating the body.
         let dominators = body.basic_blocks.dominators().clone();
 
-        let mut state = VnState::new(tcx, body, param_env, &ssa, dominators, &body.local_decls);
+        let mut state = VnState::new(tcx, body, typing_env, &ssa, dominators, &body.local_decls);
         ssa.for_each_assignment_mut(
             body.basic_blocks.as_mut_preserves_cfg(),
             |local, value, location| {
@@ -241,7 +241,6 @@ enum Value<'tcx> {
 struct VnState<'body, 'tcx> {
     tcx: TyCtxt<'tcx>,
     ecx: InterpCx<'tcx, DummyMachine>,
-    param_env: ty::ParamEnv<'tcx>,
     local_decls: &'body LocalDecls<'tcx>,
     /// Value stored in each local.
     locals: IndexVec<Local, Option<VnIndex>>,
@@ -266,7 +265,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
     fn new(
         tcx: TyCtxt<'tcx>,
         body: &Body<'tcx>,
-        param_env: ty::ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
         ssa: &'body SsaLocals,
         dominators: Dominators<BasicBlock>,
         local_decls: &'body LocalDecls<'tcx>,
@@ -280,8 +279,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 + 4 * body.basic_blocks.len();
         VnState {
             tcx,
-            ecx: InterpCx::new(tcx, DUMMY_SP, param_env, DummyMachine),
-            param_env,
+            ecx: InterpCx::new(tcx, DUMMY_SP, typing_env, DummyMachine),
             local_decls,
             locals: IndexVec::from_elem(None, local_decls),
             rev_locals: IndexVec::with_capacity(num_values),
@@ -296,7 +294,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
     }
 
     fn typing_env(&self) -> ty::TypingEnv<'tcx> {
-        ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env: self.param_env }
+        self.ecx.typing_env()
     }
 
     #[instrument(level = "trace", skip(self), ret)]
@@ -347,7 +345,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
 
         // Only register the value if its type is `Sized`, as we will emit copies of it.
         let is_sized = !self.feature_unsized_locals
-            || self.local_decls[local].ty.is_sized(self.tcx, self.param_env);
+            || self.local_decls[local].ty.is_sized(self.tcx, self.typing_env());
         if is_sized {
             self.rev_locals[value].push(local);
         }
@@ -642,7 +640,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 let ty = place.ty(self.local_decls, self.tcx).ty;
                 if let Some(Mutability::Not) = ty.ref_mutability()
                     && let Some(pointee_ty) = ty.builtin_deref(true)
-                    && pointee_ty.is_freeze(self.tcx, self.param_env)
+                    && pointee_ty.is_freeze(self.tcx, self.typing_env())
                 {
                     // An immutable borrow `_x` always points to the same value for the
                     // lifetime of the borrow, so we can merge all instances of `*_x`.
@@ -1061,7 +1059,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 && let ty::RawPtr(from_pointee_ty, from_mtbl) = cast_from.kind()
                 && let ty::RawPtr(_, output_mtbl) = output_pointer_ty.kind()
                 && from_mtbl == output_mtbl
-                && from_pointee_ty.is_sized(self.tcx, self.param_env)
+                && from_pointee_ty.is_sized(self.tcx, self.typing_env())
             {
                 fields[0] = *cast_value;
                 *data_pointer_ty = *cast_from;
@@ -1383,7 +1381,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
             && let Value::Aggregate(AggregateTy::RawPtr { data_pointer_ty, .. }, _, fields) =
                 self.get(value)
             && let ty::RawPtr(to_pointee, _) = to.kind()
-            && to_pointee.is_sized(self.tcx, self.param_env)
+            && to_pointee.is_sized(self.tcx, self.typing_env())
         {
             from = *data_pointer_ty;
             value = fields[0];
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index fcb51fbddd9..00f6c3845d4 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -199,10 +199,7 @@ impl<'tcx> Inliner<'tcx> {
         let TerminatorKind::Call { args, destination, .. } = &terminator.kind else { bug!() };
         let destination_ty = destination.ty(&caller_body.local_decls, self.tcx).ty;
         for arg in args {
-            if !arg
-                .node
-                .ty(&caller_body.local_decls, self.tcx)
-                .is_sized(self.tcx, self.typing_env.param_env)
+            if !arg.node.ty(&caller_body.local_decls, self.tcx).is_sized(self.tcx, self.typing_env)
             {
                 // We do not allow inlining functions with unsized params. Inlining these functions
                 // could create unsized locals, which are unsound and being phased out.
diff --git a/compiler/rustc_mir_transform/src/instsimplify.rs b/compiler/rustc_mir_transform/src/instsimplify.rs
index b80abcca969..3352d583f2c 100644
--- a/compiler/rustc_mir_transform/src/instsimplify.rs
+++ b/compiler/rustc_mir_transform/src/instsimplify.rs
@@ -6,7 +6,7 @@ use rustc_hir::LangItem;
 use rustc_middle::bug;
 use rustc_middle::mir::*;
 use rustc_middle::ty::layout::ValidityRequirement;
-use rustc_middle::ty::{self, GenericArgsRef, ParamEnv, Ty, TyCtxt, layout};
+use rustc_middle::ty::{self, GenericArgsRef, Ty, TyCtxt, layout};
 use rustc_span::sym;
 use rustc_span::symbol::Symbol;
 
@@ -34,7 +34,7 @@ impl<'tcx> crate::MirPass<'tcx> for InstSimplify {
         let ctx = InstSimplifyContext {
             tcx,
             local_decls: &body.local_decls,
-            param_env: tcx.param_env_reveal_all_normalized(body.source.def_id()),
+            typing_env: body.typing_env(tcx),
         };
         let preserve_ub_checks =
             attr::contains_name(tcx.hir().krate_attrs(), sym::rustc_preserve_ub_checks);
@@ -66,13 +66,7 @@ impl<'tcx> crate::MirPass<'tcx> for InstSimplify {
 struct InstSimplifyContext<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     local_decls: &'a LocalDecls<'tcx>,
-    param_env: ParamEnv<'tcx>,
-}
-
-impl<'tcx> InstSimplifyContext<'_, 'tcx> {
-    fn typing_env(&self) -> ty::TypingEnv<'tcx> {
-        ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env: self.param_env }
-    }
+    typing_env: ty::TypingEnv<'tcx>,
 }
 
 impl<'tcx> InstSimplifyContext<'_, 'tcx> {
@@ -354,7 +348,7 @@ impl<'tcx> InstSimplifyContext<'_, 'tcx> {
         }
 
         let known_is_valid =
-            intrinsic_assert_panics(self.tcx, self.typing_env(), args[0], intrinsic_name);
+            intrinsic_assert_panics(self.tcx, self.typing_env, args[0], intrinsic_name);
         match known_is_valid {
             // We don't know the layout or it's not validity assertion at all, don't touch it
             None => {}
diff --git a/compiler/rustc_mir_transform/src/jump_threading.rs b/compiler/rustc_mir_transform/src/jump_threading.rs
index 71a843a785c..beed007589b 100644
--- a/compiler/rustc_mir_transform/src/jump_threading.rs
+++ b/compiler/rustc_mir_transform/src/jump_threading.rs
@@ -82,7 +82,7 @@ impl<'tcx> crate::MirPass<'tcx> for JumpThreading {
         let mut finder = TOFinder {
             tcx,
             typing_env,
-            ecx: InterpCx::new(tcx, DUMMY_SP, typing_env.param_env, DummyMachine),
+            ecx: InterpCx::new(tcx, DUMMY_SP, typing_env, DummyMachine),
             body,
             arena,
             map: Map::new(tcx, body, Some(MAX_PLACES)),
@@ -352,6 +352,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
             | StatementKind::FakeRead(..)
             | StatementKind::ConstEvalCounter
             | StatementKind::PlaceMention(..)
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => None,
         }
     }
diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs
index 3911b0a2db6..53e282e9b46 100644
--- a/compiler/rustc_mir_transform/src/known_panics_lint.rs
+++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs
@@ -183,7 +183,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         // to runtime, so we have to manually specify the correct typing mode.
         let typing_env = ty::TypingEnv::post_analysis(tcx, body.source.def_id());
         let can_const_prop = CanConstProp::check(tcx, typing_env, body);
-        let ecx = InterpCx::new(tcx, tcx.def_span(def_id), typing_env.param_env, DummyMachine);
+        let ecx = InterpCx::new(tcx, tcx.def_span(def_id), typing_env, DummyMachine);
 
         ConstPropagator {
             ecx,
@@ -451,7 +451,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         if rvalue.has_param() {
             return None;
         }
-        if !rvalue.ty(self.local_decls(), self.tcx).is_sized(self.tcx, self.typing_env.param_env) {
+        if !rvalue.ty(self.local_decls(), self.tcx).is_sized(self.tcx, self.typing_env) {
             // the interpreter doesn't support unsized locals (only unsized arguments),
             // but rustc does (in a kinda broken way), so we have to skip them here
             return None;
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 5651bf469d5..bfb842e4485 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -50,6 +50,7 @@ mod deduce_param_attrs;
 mod errors;
 mod ffi_unwind_calls;
 mod lint;
+mod lint_tail_expr_drop_order;
 mod shim;
 mod ssa;
 
@@ -490,6 +491,7 @@ fn mir_drops_elaborated_and_const_checked(tcx: TyCtxt<'_>, def: LocalDefId) -> &
     }
 
     let (body, _) = tcx.mir_promoted(def);
+    lint_tail_expr_drop_order::run_lint(tcx, def, &body.borrow());
     let mut body = body.steal();
 
     if let Some(error_reported) = tainted_by_errors {
diff --git a/compiler/rustc_mir_transform/src/lint_tail_expr_drop_order.rs b/compiler/rustc_mir_transform/src/lint_tail_expr_drop_order.rs
new file mode 100644
index 00000000000..b8502fcbafb
--- /dev/null
+++ b/compiler/rustc_mir_transform/src/lint_tail_expr_drop_order.rs
@@ -0,0 +1,701 @@
+use std::cell::RefCell;
+use std::collections::hash_map;
+use std::rc::Rc;
+
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::unord::{UnordMap, UnordSet};
+use rustc_errors::Subdiagnostic;
+use rustc_hir::CRATE_HIR_ID;
+use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_index::bit_set::ChunkedBitSet;
+use rustc_index::{IndexSlice, IndexVec};
+use rustc_macros::{LintDiagnostic, Subdiagnostic};
+use rustc_middle::bug;
+use rustc_middle::mir::{
+    self, BasicBlock, Body, ClearCrossCrate, Local, Location, Place, StatementKind, TerminatorKind,
+    dump_mir,
+};
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_mir_dataflow::impls::MaybeInitializedPlaces;
+use rustc_mir_dataflow::move_paths::{LookupResult, MoveData, MovePathIndex};
+use rustc_mir_dataflow::{Analysis, MaybeReachable, ResultsCursor};
+use rustc_session::lint::builtin::TAIL_EXPR_DROP_ORDER;
+use rustc_session::lint::{self};
+use rustc_span::{DUMMY_SP, Span, Symbol};
+use rustc_type_ir::data_structures::IndexMap;
+use smallvec::{SmallVec, smallvec};
+use tracing::{debug, instrument};
+
+fn place_has_common_prefix<'tcx>(left: &Place<'tcx>, right: &Place<'tcx>) -> bool {
+    left.local == right.local
+        && left.projection.iter().zip(right.projection).all(|(left, right)| left == right)
+}
+
+/// Cache entry of `drop` at a `BasicBlock`
+#[derive(Debug, Clone, Copy)]
+enum MovePathIndexAtBlock {
+    /// We know nothing yet
+    Unknown,
+    /// We know that the `drop` here has no effect
+    None,
+    /// We know that the `drop` here will invoke a destructor
+    Some(MovePathIndex),
+}
+
+struct DropsReachable<'a, 'mir, 'tcx> {
+    body: &'a Body<'tcx>,
+    place: &'a Place<'tcx>,
+    drop_span: &'a mut Option<Span>,
+    move_data: &'a MoveData<'tcx>,
+    maybe_init: &'a mut ResultsCursor<'mir, 'tcx, MaybeInitializedPlaces<'mir, 'tcx>>,
+    block_drop_value_info: &'a mut IndexSlice<BasicBlock, MovePathIndexAtBlock>,
+    collected_drops: &'a mut ChunkedBitSet<MovePathIndex>,
+    visited: FxHashMap<BasicBlock, Rc<RefCell<ChunkedBitSet<MovePathIndex>>>>,
+}
+
+impl<'a, 'mir, 'tcx> DropsReachable<'a, 'mir, 'tcx> {
+    fn visit(&mut self, block: BasicBlock) {
+        let move_set_size = self.move_data.move_paths.len();
+        let make_new_path_set = || Rc::new(RefCell::new(ChunkedBitSet::new_empty(move_set_size)));
+
+        let data = &self.body.basic_blocks[block];
+        let Some(terminator) = &data.terminator else { return };
+        // Given that we observe these dropped locals here at `block` so far,
+        // we will try to update the successor blocks.
+        // An occupied entry at `block` in `self.visited` signals that we have visited `block` before.
+        let dropped_local_here =
+            Rc::clone(self.visited.entry(block).or_insert_with(make_new_path_set));
+        // We could have invoked reverse lookup for a `MovePathIndex` every time, but unfortunately it is expensive.
+        // Let's cache them in `self.block_drop_value_info`.
+        match self.block_drop_value_info[block] {
+            MovePathIndexAtBlock::Some(dropped) => {
+                dropped_local_here.borrow_mut().insert(dropped);
+            }
+            MovePathIndexAtBlock::Unknown => {
+                if let TerminatorKind::Drop { place, .. } = &terminator.kind
+                    && let LookupResult::Exact(idx) | LookupResult::Parent(Some(idx)) =
+                        self.move_data.rev_lookup.find(place.as_ref())
+                {
+                    // Since we are working with MIRs at a very early stage,
+                    // observing a `drop` terminator is not indicative enough that
+                    // the drop will definitely happen.
+                    // That is decided in the drop elaboration pass instead.
+                    // Therefore, we need to consult with the maybe-initialization information.
+                    self.maybe_init.seek_before_primary_effect(Location {
+                        block,
+                        statement_index: data.statements.len(),
+                    });
+
+                    // Check if the drop of `place` under inspection is really in effect.
+                    // This is true only when `place` may have been initialized along a control flow path from a BID to the drop program point today.
+                    // In other words, this is where the drop of `place` will happen in the future instead.
+                    if let MaybeReachable::Reachable(maybe_init) = self.maybe_init.get()
+                        && maybe_init.contains(idx)
+                    {
+                        // We also cache the drop information, so that we do not need to check on data-flow cursor again
+                        self.block_drop_value_info[block] = MovePathIndexAtBlock::Some(idx);
+                        dropped_local_here.borrow_mut().insert(idx);
+                    } else {
+                        self.block_drop_value_info[block] = MovePathIndexAtBlock::None;
+                    }
+                }
+            }
+            MovePathIndexAtBlock::None => {}
+        }
+
+        for succ in terminator.successors() {
+            let target = &self.body.basic_blocks[succ];
+            if target.is_cleanup {
+                continue;
+            }
+
+            // As long as we are passing through a new block, or new dropped places to propagate,
+            // we will proceed with `succ`
+            let dropped_local_there = match self.visited.entry(succ) {
+                hash_map::Entry::Occupied(occupied_entry) => {
+                    if succ == block
+                        || !occupied_entry.get().borrow_mut().union(&*dropped_local_here.borrow())
+                    {
+                        // `succ` has been visited but no new drops observed so far,
+                        // so we can bail on `succ` until new drop information arrives
+                        continue;
+                    }
+                    Rc::clone(occupied_entry.get())
+                }
+                hash_map::Entry::Vacant(vacant_entry) => Rc::clone(
+                    vacant_entry.insert(Rc::new(RefCell::new(dropped_local_here.borrow().clone()))),
+                ),
+            };
+            if let Some(terminator) = &target.terminator
+                && let TerminatorKind::Drop {
+                    place: dropped_place,
+                    target: _,
+                    unwind: _,
+                    replace: _,
+                } = &terminator.kind
+                && place_has_common_prefix(dropped_place, self.place)
+            {
+                // We have now reached the current drop of the `place`.
+                // Let's check the observed dropped places in.
+                self.collected_drops.union(&*dropped_local_there.borrow());
+                if self.drop_span.is_none() {
+                    // FIXME(@dingxiangfei2009): it turns out that `self.body.source_scopes` are still a bit wonky.
+                    // There is a high chance that this span still points to a block rather than a statement semicolon.
+                    *self.drop_span = Some(terminator.source_info.span);
+                }
+                // Now we have discovered a simple control flow path from a future drop point
+                // to the current drop point.
+                // We will not continue from there.
+            } else {
+                self.visit(succ)
+            }
+        }
+    }
+}
+
+/// An additional filter to exclude well-known types from the ecosystem
+/// because their drops are trivial.
+/// This returns additional types to check if the drops are delegated to those.
+/// A typical example is `hashbrown::HashMap<K, V>`, whose drop is delegated to `K` and `V`.
+fn true_significant_drop_ty<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    ty: Ty<'tcx>,
+) -> Option<SmallVec<[Ty<'tcx>; 2]>> {
+    if let ty::Adt(def, args) = ty.kind() {
+        let mut did = def.did();
+        let mut name_rev = vec![];
+        loop {
+            let key = tcx.def_key(did);
+
+            match key.disambiguated_data.data {
+                rustc_hir::definitions::DefPathData::CrateRoot => {
+                    name_rev.push(tcx.crate_name(did.krate))
+                }
+                rustc_hir::definitions::DefPathData::TypeNs(symbol) => name_rev.push(symbol),
+                _ => return None,
+            }
+            if let Some(parent) = key.parent {
+                did = DefId { krate: did.krate, index: parent };
+            } else {
+                break;
+            }
+        }
+        let name_str: Vec<_> = name_rev.iter().rev().map(|x| x.as_str()).collect();
+        debug!(?name_str);
+        match name_str[..] {
+            // These are the types from Rust core ecosystem
+            ["sym" | "proc_macro2", ..]
+            | ["core" | "std", "task", "LocalWaker" | "Waker"]
+            | ["core" | "std", "task", "wake", "LocalWaker" | "Waker"] => Some(smallvec![]),
+            // These are important types from Rust ecosystem
+            ["tracing", "instrument", "Instrumented"] | ["bytes", "Bytes"] => Some(smallvec![]),
+            ["hashbrown", "raw", "RawTable" | "RawIntoIter"] => {
+                if let [ty, ..] = &***args
+                    && let Some(ty) = ty.as_type()
+                {
+                    Some(smallvec![ty])
+                } else {
+                    None
+                }
+            }
+            ["hashbrown", "raw", "RawDrain"] => {
+                if let [_, ty, ..] = &***args
+                    && let Some(ty) = ty.as_type()
+                {
+                    Some(smallvec![ty])
+                } else {
+                    None
+                }
+            }
+            _ => None,
+        }
+    } else {
+        None
+    }
+}
+
+/// Returns the list of types with a "potentially sigificant" that may be dropped
+/// by dropping a value of type `ty`.
+#[instrument(level = "debug", skip(tcx, param_env))]
+fn extract_component_raw<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+    ty: Ty<'tcx>,
+    ty_seen: &mut UnordSet<Ty<'tcx>>,
+) -> SmallVec<[Ty<'tcx>; 4]> {
+    // Droppiness does not depend on regions, so let us erase them.
+    let ty = tcx
+        .try_normalize_erasing_regions(
+            ty::TypingEnv { param_env, typing_mode: ty::TypingMode::PostAnalysis },
+            ty,
+        )
+        .unwrap_or(ty);
+
+    let tys = tcx.list_significant_drop_tys(param_env.and(ty));
+    debug!(?ty, "components");
+    let mut out_tys = smallvec![];
+    for ty in tys {
+        if let Some(tys) = true_significant_drop_ty(tcx, ty) {
+            // Some types can be further opened up because the drop is simply delegated
+            for ty in tys {
+                if ty_seen.insert(ty) {
+                    out_tys.extend(extract_component_raw(tcx, param_env, ty, ty_seen));
+                }
+            }
+        } else {
+            if ty_seen.insert(ty) {
+                out_tys.push(ty);
+            }
+        }
+    }
+    out_tys
+}
+
+#[instrument(level = "debug", skip(tcx, param_env))]
+fn extract_component_with_significant_dtor<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+    ty: Ty<'tcx>,
+) -> SmallVec<[Ty<'tcx>; 4]> {
+    let mut tys = extract_component_raw(tcx, param_env, ty, &mut Default::default());
+    let mut deduplicate = FxHashSet::default();
+    tys.retain(|oty| deduplicate.insert(*oty));
+    tys.into_iter().collect()
+}
+
+/// Extract the span of the custom destructor of a type
+/// especially the span of the `impl Drop` header or its entire block
+/// when we are working with current local crate.
+#[instrument(level = "debug", skip(tcx))]
+fn ty_dtor_span<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Span> {
+    match ty.kind() {
+        ty::Bool
+        | ty::Char
+        | ty::Int(_)
+        | ty::Uint(_)
+        | ty::Float(_)
+        | ty::Error(_)
+        | ty::Str
+        | ty::Never
+        | ty::RawPtr(_, _)
+        | ty::Ref(_, _, _)
+        | ty::FnPtr(_, _)
+        | ty::Tuple(_)
+        | ty::Dynamic(_, _, _)
+        | ty::Alias(_, _)
+        | ty::Bound(_, _)
+        | ty::Pat(_, _)
+        | ty::Placeholder(_)
+        | ty::Infer(_)
+        | ty::Slice(_)
+        | ty::Array(_, _) => None,
+        ty::Adt(adt_def, _) => {
+            let did = adt_def.did();
+            let try_local_did_span = |did: DefId| {
+                if let Some(local) = did.as_local() {
+                    tcx.source_span(local)
+                } else {
+                    tcx.def_span(did)
+                }
+            };
+            let dtor = if let Some(dtor) = tcx.adt_destructor(did) {
+                dtor.did
+            } else if let Some(dtor) = tcx.adt_async_destructor(did) {
+                dtor.future
+            } else {
+                return Some(try_local_did_span(did));
+            };
+            let def_key = tcx.def_key(dtor);
+            let Some(parent_index) = def_key.parent else { return Some(try_local_did_span(dtor)) };
+            let parent_did = DefId { index: parent_index, krate: dtor.krate };
+            Some(try_local_did_span(parent_did))
+        }
+        ty::Coroutine(did, _)
+        | ty::CoroutineWitness(did, _)
+        | ty::CoroutineClosure(did, _)
+        | ty::Closure(did, _)
+        | ty::FnDef(did, _)
+        | ty::Foreign(did) => Some(tcx.def_span(did)),
+        ty::Param(_) => None,
+    }
+}
+
+/// Check if a moved place at `idx` is a part of a BID.
+/// The use of this check is that we will consider drops on these
+/// as a drop of the overall BID and, thus, we can exclude it from the diagnosis.
+fn place_descendent_of_bids<'tcx>(
+    mut idx: MovePathIndex,
+    move_data: &MoveData<'tcx>,
+    bids: &UnordSet<&Place<'tcx>>,
+) -> bool {
+    loop {
+        let path = &move_data.move_paths[idx];
+        if bids.contains(&path.place) {
+            return true;
+        }
+        if let Some(parent) = path.parent {
+            idx = parent;
+        } else {
+            return false;
+        }
+    }
+}
+
+/// The core of the lint `tail-expr-drop-order`
+pub(crate) fn run_lint<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &Body<'tcx>) {
+    if matches!(tcx.def_kind(def_id), rustc_hir::def::DefKind::SyntheticCoroutineBody) {
+        // A synthetic coroutine has no HIR body and it is enough to just analyse the original body
+        return;
+    }
+    if body.span.edition().at_least_rust_2024()
+        || tcx.lints_that_dont_need_to_run(()).contains(&lint::LintId::of(TAIL_EXPR_DROP_ORDER))
+    {
+        return;
+    }
+    // ## About BIDs in blocks ##
+    // Track the set of blocks that contain a backwards-incompatible drop (BID)
+    // and, for each block, the vector of locations.
+    //
+    // We group them per-block because they tend to scheduled in the same drop ladder block.
+    let mut bid_per_block = IndexMap::default();
+    let mut bid_places = UnordSet::new();
+    let param_env = tcx.param_env(def_id).with_reveal_all_normalized(tcx);
+    let mut ty_dropped_components = UnordMap::default();
+    for (block, data) in body.basic_blocks.iter_enumerated() {
+        for (statement_index, stmt) in data.statements.iter().enumerate() {
+            if let StatementKind::BackwardIncompatibleDropHint { place, reason: _ } = &stmt.kind {
+                let ty = place.ty(body, tcx).ty;
+                if ty_dropped_components
+                    .entry(ty)
+                    .or_insert_with(|| extract_component_with_significant_dtor(tcx, param_env, ty))
+                    .is_empty()
+                {
+                    continue;
+                }
+                bid_per_block
+                    .entry(block)
+                    .or_insert(vec![])
+                    .push((Location { block, statement_index }, &**place));
+                bid_places.insert(&**place);
+            }
+        }
+    }
+    if bid_per_block.is_empty() {
+        return;
+    }
+
+    dump_mir(tcx, false, "lint_tail_expr_drop_order", &0 as _, body, |_, _| Ok(()));
+    let locals_with_user_names = collect_user_names(body);
+    let is_closure_like = tcx.is_closure_like(def_id.to_def_id());
+
+    // Compute the "maybe initialized" information for this body.
+    // When we encounter a DROP of some place P we only care
+    // about the drop if `P` may be initialized.
+    let move_data = MoveData::gather_moves(body, tcx, |_| true);
+    let maybe_init = MaybeInitializedPlaces::new(tcx, body, &move_data);
+    let mut maybe_init = maybe_init.iterate_to_fixpoint(tcx, body, None).into_results_cursor(body);
+    let mut block_drop_value_info =
+        IndexVec::from_elem_n(MovePathIndexAtBlock::Unknown, body.basic_blocks.len());
+    for (&block, candidates) in &bid_per_block {
+        // We will collect drops on locals on paths between BID points to their actual drop locations
+        // into `all_locals_dropped`.
+        let mut all_locals_dropped = ChunkedBitSet::new_empty(move_data.move_paths.len());
+        let mut drop_span = None;
+        for &(_, place) in candidates.iter() {
+            let mut collected_drops = ChunkedBitSet::new_empty(move_data.move_paths.len());
+            // ## On detecting change in relative drop order ##
+            // Iterate through each BID-containing block `block`.
+            // If the place `P` targeted by the BID is "maybe initialized",
+            // then search forward to find the actual `DROP(P)` point.
+            // Everything dropped between the BID and the actual drop point
+            // is something whose relative drop order will change.
+            DropsReachable {
+                body,
+                place,
+                drop_span: &mut drop_span,
+                move_data: &move_data,
+                maybe_init: &mut maybe_init,
+                block_drop_value_info: &mut block_drop_value_info,
+                collected_drops: &mut collected_drops,
+                visited: Default::default(),
+            }
+            .visit(block);
+            // Compute the set `all_locals_dropped` of local variables that are dropped
+            // after the BID point but before the current drop point.
+            //
+            // These are the variables whose drop impls will be reordered with respect
+            // to `place`.
+            all_locals_dropped.union(&collected_drops);
+        }
+
+        // We shall now exclude some local bindings for the following cases.
+        {
+            let mut to_exclude = ChunkedBitSet::new_empty(all_locals_dropped.domain_size());
+            // We will now do subtraction from the candidate dropped locals, because of the following reasons.
+            for path_idx in all_locals_dropped.iter() {
+                let move_path = &move_data.move_paths[path_idx];
+                let dropped_local = move_path.place.local;
+                // a) A return value _0 will eventually be used
+                // Example:
+                // fn f() -> Droppy {
+                //     let _x = Droppy;
+                //     Droppy
+                // }
+                // _0 holds the literal `Droppy` and rightfully `_x` has to be dropped first
+                if dropped_local == Local::ZERO {
+                    debug!(?dropped_local, "skip return value");
+                    to_exclude.insert(path_idx);
+                    continue;
+                }
+                // b) If we are analysing a closure, the captures are still dropped last.
+                // This is part of the closure capture lifetime contract.
+                // They are similar to the return value _0 with respect to lifetime rules.
+                if is_closure_like && matches!(dropped_local, ty::CAPTURE_STRUCT_LOCAL) {
+                    debug!(?dropped_local, "skip closure captures");
+                    to_exclude.insert(path_idx);
+                    continue;
+                }
+                // c) Sometimes we collect places that are projections into the BID locals,
+                // so they are considered dropped now.
+                // Example:
+                // struct NotVeryDroppy(Droppy);
+                // impl Drop for Droppy {..}
+                // fn f() -> NotVeryDroppy {
+                //    let x = NotVeryDroppy(droppy());
+                //    {
+                //        let y: Droppy = x.0;
+                //        NotVeryDroppy(y)
+                //    }
+                // }
+                // `y` takes `x.0`, which invalidates `x` as a complete `NotVeryDroppy`
+                // so there is no point in linting against `x` any more.
+                if place_descendent_of_bids(path_idx, &move_data, &bid_places) {
+                    debug!(?dropped_local, "skip descendent of bids");
+                    to_exclude.insert(path_idx);
+                    continue;
+                }
+                let observer_ty = move_path.place.ty(body, tcx).ty;
+                // d) The collected local has no custom destructor that passes our ecosystem filter.
+                if ty_dropped_components
+                    .entry(observer_ty)
+                    .or_insert_with(|| {
+                        extract_component_with_significant_dtor(tcx, param_env, observer_ty)
+                    })
+                    .is_empty()
+                {
+                    debug!(?dropped_local, "skip non-droppy types");
+                    to_exclude.insert(path_idx);
+                    continue;
+                }
+            }
+            // Suppose that all BIDs point into the same local,
+            // we can remove the this local from the observed drops,
+            // so that we can focus our diagnosis more on the others.
+            if candidates.iter().all(|&(_, place)| candidates[0].1.local == place.local) {
+                for path_idx in all_locals_dropped.iter() {
+                    if move_data.move_paths[path_idx].place.local == candidates[0].1.local {
+                        to_exclude.insert(path_idx);
+                    }
+                }
+            }
+            all_locals_dropped.subtract(&to_exclude);
+        }
+        if all_locals_dropped.is_empty() {
+            // No drop effect is observable, so let us move on.
+            continue;
+        }
+
+        // ## The final work to assemble the diagnosis ##
+        // First collect or generate fresh names for local variable bindings and temporary values.
+        let local_names = assign_observables_names(
+            all_locals_dropped
+                .iter()
+                .map(|path_idx| move_data.move_paths[path_idx].place.local)
+                .chain(candidates.iter().map(|(_, place)| place.local)),
+            &locals_with_user_names,
+        );
+
+        let mut lint_root = None;
+        let mut local_labels = vec![];
+        // We now collect the types with custom destructors.
+        for &(_, place) in candidates {
+            let linted_local_decl = &body.local_decls[place.local];
+            let Some(&(ref name, is_generated_name)) = local_names.get(&place.local) else {
+                bug!("a name should have been assigned")
+            };
+            let name = name.as_str();
+
+            if lint_root.is_none()
+                && let ClearCrossCrate::Set(data) =
+                    &body.source_scopes[linted_local_decl.source_info.scope].local_data
+            {
+                lint_root = Some(data.lint_root);
+            }
+
+            // Collect spans of the custom destructors.
+            let mut seen_dyn = false;
+            let destructors = ty_dropped_components
+                .get(&linted_local_decl.ty)
+                .unwrap()
+                .iter()
+                .filter_map(|&ty| {
+                    if let Some(span) = ty_dtor_span(tcx, ty) {
+                        Some(DestructorLabel { span, name, dtor_kind: "concrete" })
+                    } else if matches!(ty.kind(), ty::Dynamic(..)) {
+                        if seen_dyn {
+                            None
+                        } else {
+                            seen_dyn = true;
+                            Some(DestructorLabel { span: DUMMY_SP, name, dtor_kind: "dyn" })
+                        }
+                    } else {
+                        None
+                    }
+                })
+                .collect();
+            local_labels.push(LocalLabel {
+                span: linted_local_decl.source_info.span,
+                destructors,
+                name,
+                is_generated_name,
+                is_dropped_first_edition_2024: true,
+            });
+        }
+
+        // Similarly, custom destructors of the observed drops.
+        for path_idx in all_locals_dropped.iter() {
+            let place = &move_data.move_paths[path_idx].place;
+            // We are not using the type of the local because the drop may be partial.
+            let observer_ty = place.ty(body, tcx).ty;
+
+            let observer_local_decl = &body.local_decls[place.local];
+            let Some(&(ref name, is_generated_name)) = local_names.get(&place.local) else {
+                bug!("a name should have been assigned")
+            };
+            let name = name.as_str();
+
+            let mut seen_dyn = false;
+            let destructors = extract_component_with_significant_dtor(tcx, param_env, observer_ty)
+                .into_iter()
+                .filter_map(|ty| {
+                    if let Some(span) = ty_dtor_span(tcx, ty) {
+                        Some(DestructorLabel { span, name, dtor_kind: "concrete" })
+                    } else if matches!(ty.kind(), ty::Dynamic(..)) {
+                        if seen_dyn {
+                            None
+                        } else {
+                            seen_dyn = true;
+                            Some(DestructorLabel { span: DUMMY_SP, name, dtor_kind: "dyn" })
+                        }
+                    } else {
+                        None
+                    }
+                })
+                .collect();
+            local_labels.push(LocalLabel {
+                span: observer_local_decl.source_info.span,
+                destructors,
+                name,
+                is_generated_name,
+                is_dropped_first_edition_2024: false,
+            });
+        }
+
+        let span = local_labels[0].span;
+        tcx.emit_node_span_lint(
+            lint::builtin::TAIL_EXPR_DROP_ORDER,
+            lint_root.unwrap_or(CRATE_HIR_ID),
+            span,
+            TailExprDropOrderLint { local_labels, drop_span, _epilogue: () },
+        );
+    }
+}
+
+/// Extract binding names if available for diagnosis
+fn collect_user_names(body: &Body<'_>) -> IndexMap<Local, Symbol> {
+    let mut names = IndexMap::default();
+    for var_debug_info in &body.var_debug_info {
+        if let mir::VarDebugInfoContents::Place(place) = &var_debug_info.value
+            && let Some(local) = place.local_or_deref_local()
+        {
+            names.entry(local).or_insert(var_debug_info.name);
+        }
+    }
+    names
+}
+
+/// Assign names for anonymous or temporary values for diagnosis
+fn assign_observables_names(
+    locals: impl IntoIterator<Item = Local>,
+    user_names: &IndexMap<Local, Symbol>,
+) -> IndexMap<Local, (String, bool)> {
+    let mut names = IndexMap::default();
+    let mut assigned_names = FxHashSet::default();
+    let mut idx = 0u64;
+    let mut fresh_name = || {
+        idx += 1;
+        (format!("#{idx}"), true)
+    };
+    for local in locals {
+        let name = if let Some(name) = user_names.get(&local) {
+            let name = name.as_str();
+            if assigned_names.contains(name) { fresh_name() } else { (name.to_owned(), false) }
+        } else {
+            fresh_name()
+        };
+        assigned_names.insert(name.0.clone());
+        names.insert(local, name);
+    }
+    names
+}
+
+#[derive(LintDiagnostic)]
+#[diag(mir_transform_tail_expr_drop_order)]
+struct TailExprDropOrderLint<'a> {
+    #[subdiagnostic]
+    local_labels: Vec<LocalLabel<'a>>,
+    #[label(mir_transform_drop_location)]
+    drop_span: Option<Span>,
+    #[note(mir_transform_note_epilogue)]
+    _epilogue: (),
+}
+
+struct LocalLabel<'a> {
+    span: Span,
+    name: &'a str,
+    is_generated_name: bool,
+    is_dropped_first_edition_2024: bool,
+    destructors: Vec<DestructorLabel<'a>>,
+}
+
+/// A custom `Subdiagnostic` implementation so that the notes are delivered in a specific order
+impl Subdiagnostic for LocalLabel<'_> {
+    fn add_to_diag_with<
+        G: rustc_errors::EmissionGuarantee,
+        F: rustc_errors::SubdiagMessageOp<G>,
+    >(
+        self,
+        diag: &mut rustc_errors::Diag<'_, G>,
+        f: &F,
+    ) {
+        diag.arg("name", self.name);
+        diag.arg("is_generated_name", self.is_generated_name);
+        diag.arg("is_dropped_first_edition_2024", self.is_dropped_first_edition_2024);
+        let msg = f(diag, crate::fluent_generated::mir_transform_tail_expr_local.into());
+        diag.span_label(self.span, msg);
+        for dtor in self.destructors {
+            dtor.add_to_diag_with(diag, f);
+        }
+        let msg = f(diag, crate::fluent_generated::mir_transform_label_local_epilogue.into());
+        diag.span_label(self.span, msg);
+    }
+}
+
+#[derive(Subdiagnostic)]
+#[note(mir_transform_tail_expr_dtor)]
+struct DestructorLabel<'a> {
+    #[primary_span]
+    span: Span,
+    dtor_kind: &'static str,
+    name: &'a str,
+}
diff --git a/compiler/rustc_mir_transform/src/ref_prop.rs b/compiler/rustc_mir_transform/src/ref_prop.rs
index b11b503e8d4..af438ac2177 100644
--- a/compiler/rustc_mir_transform/src/ref_prop.rs
+++ b/compiler/rustc_mir_transform/src/ref_prop.rs
@@ -85,8 +85,8 @@ impl<'tcx> crate::MirPass<'tcx> for ReferencePropagation {
 }
 
 fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) -> bool {
-    let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
-    let ssa = SsaLocals::new(tcx, body, param_env);
+    let typing_env = body.typing_env(tcx);
+    let ssa = SsaLocals::new(tcx, body, typing_env);
 
     let mut replacer = compute_replacement(tcx, body, &ssa);
     debug!(?replacer.targets);
diff --git a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
index 55394e93a5c..fd49e956f43 100644
--- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
+++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
@@ -92,6 +92,7 @@ impl RemoveNoopLandingPads {
                 | StatementKind::AscribeUserType(..)
                 | StatementKind::Coverage(..)
                 | StatementKind::ConstEvalCounter
+                | StatementKind::BackwardIncompatibleDropHint { .. }
                 | StatementKind::Nop => {
                     // These are all noops in a landing pad
                 }
diff --git a/compiler/rustc_mir_transform/src/remove_zsts.rs b/compiler/rustc_mir_transform/src/remove_zsts.rs
index 2f723bccc19..6fd70fbe9b0 100644
--- a/compiler/rustc_mir_transform/src/remove_zsts.rs
+++ b/compiler/rustc_mir_transform/src/remove_zsts.rs
@@ -125,6 +125,7 @@ impl<'tcx> MutVisitor<'tcx> for Replacer<'_, 'tcx> {
             StatementKind::Coverage(_)
             | StatementKind::Intrinsic(_)
             | StatementKind::Nop
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::ConstEvalCounter => None,
         };
         if let Some(place_for_ty) = place_for_ty
diff --git a/compiler/rustc_mir_transform/src/simplify.rs b/compiler/rustc_mir_transform/src/simplify.rs
index 7ed43547e11..4f312ed2aaa 100644
--- a/compiler/rustc_mir_transform/src/simplify.rs
+++ b/compiler/rustc_mir_transform/src/simplify.rs
@@ -523,7 +523,8 @@ impl<'tcx> Visitor<'tcx> for UsedLocals {
             }
 
             StatementKind::SetDiscriminant { ref place, variant_index: _ }
-            | StatementKind::Deinit(ref place) => {
+            | StatementKind::Deinit(ref place)
+            | StatementKind::BackwardIncompatibleDropHint { ref place, reason: _ } => {
                 self.visit_lhs(place, location);
             }
         }
@@ -560,6 +561,7 @@ fn remove_unused_definitions_helper(used_locals: &mut UsedLocals, body: &mut Bod
                     StatementKind::Assign(box (place, _)) => used_locals.is_used(place.local),
 
                     StatementKind::SetDiscriminant { ref place, .. }
+                    | StatementKind::BackwardIncompatibleDropHint { ref place, reason: _ }
                     | StatementKind::Deinit(ref place) => used_locals.is_used(place.local),
                     StatementKind::Nop => false,
                     _ => true,
@@ -587,6 +589,20 @@ impl<'tcx> MutVisitor<'tcx> for LocalUpdater<'tcx> {
         self.tcx
     }
 
+    fn visit_statement(&mut self, statement: &mut Statement<'tcx>, location: Location) {
+        if let StatementKind::BackwardIncompatibleDropHint { place, reason: _ } =
+            &mut statement.kind
+        {
+            self.visit_local(
+                &mut place.local,
+                PlaceContext::MutatingUse(MutatingUseContext::Store),
+                location,
+            );
+        } else {
+            self.super_statement(statement, location);
+        }
+    }
+
     fn visit_local(&mut self, l: &mut Local, _: PlaceContext, _: Location) {
         *l = self.map[*l].unwrap();
     }
diff --git a/compiler/rustc_mir_transform/src/ssa.rs b/compiler/rustc_mir_transform/src/ssa.rs
index 84df666e34a..5653aef0aae 100644
--- a/compiler/rustc_mir_transform/src/ssa.rs
+++ b/compiler/rustc_mir_transform/src/ssa.rs
@@ -13,7 +13,7 @@ use rustc_middle::bug;
 use rustc_middle::middle::resolve_bound_vars::Set1;
 use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
-use rustc_middle::ty::{ParamEnv, TyCtxt};
+use rustc_middle::ty::{self, TyCtxt};
 use tracing::{debug, instrument, trace};
 
 pub(super) struct SsaLocals {
@@ -42,7 +42,7 @@ impl SsaLocals {
     pub(super) fn new<'tcx>(
         tcx: TyCtxt<'tcx>,
         body: &Body<'tcx>,
-        param_env: ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
     ) -> SsaLocals {
         let assignment_order = Vec::with_capacity(body.local_decls.len());
 
@@ -80,7 +80,7 @@ impl SsaLocals {
         // have already been marked as non-SSA.
         debug!(?visitor.borrowed_locals);
         for local in visitor.borrowed_locals.iter() {
-            if !body.local_decls[local].ty.is_freeze(tcx, param_env) {
+            if !body.local_decls[local].ty.is_freeze(tcx, typing_env) {
                 visitor.assignments[local] = Set1::Many;
             }
         }
diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs
index ae0e6f594ee..1739fdcc9af 100644
--- a/compiler/rustc_mir_transform/src/validate.rs
+++ b/compiler/rustc_mir_transform/src/validate.rs
@@ -343,6 +343,7 @@ impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> {
             | StatementKind::Intrinsic(_)
             | StatementKind::ConstEvalCounter
             | StatementKind::PlaceMention(..)
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => {}
         }
 
@@ -623,7 +624,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             if let Operand::Copy(place) = operand {
                 let ty = place.ty(&self.body.local_decls, self.tcx).ty;
 
-                if !ty.is_copy_modulo_regions(self.tcx, self.typing_env.param_env) {
+                if !ty.is_copy_modulo_regions(self.tcx, self.typing_env) {
                     self.fail(location, format!("`Operand::Copy` with non-`Copy` type {ty}"));
                 }
             }
@@ -989,7 +990,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                             }
 
                             // FIXME: check `Thin` instead of `Sized`
-                            if !in_pointee.is_sized(self.tcx, self.typing_env.param_env) {
+                            if !in_pointee.is_sized(self.tcx, self.typing_env) {
                                 self.fail(location, "input pointer must be thin");
                             }
                         } else {
@@ -1004,7 +1005,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                             if !self.mir_assign_valid_types(metadata_ty, self.tcx.types.usize) {
                                 self.fail(location, "slice metadata must be usize");
                             }
-                        } else if pointee_ty.is_sized(self.tcx, self.typing_env.param_env) {
+                        } else if pointee_ty.is_sized(self.tcx, self.typing_env) {
                             if metadata_ty != self.tcx.types.unit {
                                 self.fail(location, "metadata for pointer-to-thin must be unit");
                             }
@@ -1294,7 +1295,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                             if !self
                                 .tcx
                                 .normalize_erasing_regions(self.typing_env, op_ty)
-                                .is_sized(self.tcx, self.typing_env.param_env)
+                                .is_sized(self.tcx, self.typing_env)
                             {
                                 self.fail(
                                     location,
@@ -1304,7 +1305,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                             if !self
                                 .tcx
                                 .normalize_erasing_regions(self.typing_env, *target_type)
-                                .is_sized(self.tcx, self.typing_env.param_env)
+                                .is_sized(self.tcx, self.typing_env)
                             {
                                 self.fail(
                                     location,
@@ -1493,6 +1494,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             | StatementKind::Coverage(_)
             | StatementKind::ConstEvalCounter
             | StatementKind::PlaceMention(..)
+            | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => {}
         }
 
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 1b94c627f81..8ee9ac3df72 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -1036,7 +1036,7 @@ fn find_vtable_types_for_unsizing<'tcx>(
     let ptr_vtable = |inner_source: Ty<'tcx>, inner_target: Ty<'tcx>| {
         let typing_env = ty::TypingEnv::fully_monomorphized();
         let type_has_metadata = |ty: Ty<'tcx>| -> bool {
-            if ty.is_sized(tcx.tcx, typing_env.param_env) {
+            if ty.is_sized(tcx.tcx, typing_env) {
                 return false;
             }
             let tail = tcx.struct_tail_for_codegen(ty, typing_env);
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
index ebf7372926f..78344571088 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
@@ -159,13 +159,6 @@ where
         goal: Goal<I, Self>,
     ) -> Result<Candidate<I>, NoSolution>;
 
-    /// A type is `PointerLike` if we can compute its layout, and that layout
-    /// matches the layout of `usize`.
-    fn consider_builtin_pointer_like_candidate(
-        ecx: &mut EvalCtxt<'_, D>,
-        goal: Goal<I, Self>,
-    ) -> Result<Candidate<I>, NoSolution>;
-
     /// A type is a `FnPtr` if it is of `FnPtr` type.
     fn consider_builtin_fn_ptr_trait_candidate(
         ecx: &mut EvalCtxt<'_, D>,
@@ -449,9 +442,6 @@ where
                         ty::ClosureKind::FnOnce,
                     )
                 }
-                Some(TraitSolverLangItem::PointerLike) => {
-                    G::consider_builtin_pointer_like_candidate(self, goal)
-                }
                 Some(TraitSolverLangItem::FnPtrTrait) => {
                     G::consider_builtin_fn_ptr_trait_candidate(self, goal)
                 }
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
index 5c1a7852dc0..a56febec48c 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs
@@ -633,6 +633,76 @@ fn coroutine_closure_to_ambiguous_coroutine<I: Interner>(
     )
 }
 
+/// This duplicates `extract_tupled_inputs_and_output_from_callable` but needs
+/// to return different information (namely, the def id and args) so that we can
+/// create const conditions.
+///
+/// Doing so on all calls to `extract_tupled_inputs_and_output_from_callable`
+/// would be wasteful.
+pub(in crate::solve) fn extract_fn_def_from_const_callable<I: Interner>(
+    cx: I,
+    self_ty: I::Ty,
+) -> Result<(ty::Binder<I, (I::FnInputTys, I::Ty)>, I::DefId, I::GenericArgs), NoSolution> {
+    match self_ty.kind() {
+        ty::FnDef(def_id, args) => {
+            let sig = cx.fn_sig(def_id);
+            if sig.skip_binder().is_fn_trait_compatible()
+                && !cx.has_target_features(def_id)
+                && cx.fn_is_const(def_id)
+            {
+                Ok((
+                    sig.instantiate(cx, args).map_bound(|sig| (sig.inputs(), sig.output())),
+                    def_id,
+                    args,
+                ))
+            } else {
+                return Err(NoSolution);
+            }
+        }
+        // `FnPtr`s are not const for now.
+        ty::FnPtr(..) => {
+            return Err(NoSolution);
+        }
+        // `Closure`s are not const for now.
+        ty::Closure(..) => {
+            return Err(NoSolution);
+        }
+        // `CoroutineClosure`s are not const for now.
+        ty::CoroutineClosure(..) => {
+            return Err(NoSolution);
+        }
+
+        ty::Bool
+        | ty::Char
+        | ty::Int(_)
+        | ty::Uint(_)
+        | ty::Float(_)
+        | ty::Adt(_, _)
+        | ty::Foreign(_)
+        | ty::Str
+        | ty::Array(_, _)
+        | ty::Slice(_)
+        | ty::RawPtr(_, _)
+        | ty::Ref(_, _, _)
+        | ty::Dynamic(_, _, _)
+        | ty::Coroutine(_, _)
+        | ty::CoroutineWitness(..)
+        | ty::Never
+        | ty::Tuple(_)
+        | ty::Pat(_, _)
+        | ty::Alias(_, _)
+        | ty::Param(_)
+        | ty::Placeholder(..)
+        | ty::Infer(ty::IntVar(_) | ty::FloatVar(_))
+        | ty::Error(_) => return Err(NoSolution),
+
+        ty::Bound(..)
+        | ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => {
+            panic!("unexpected type `{self_ty:?}`")
+        }
+    }
+}
+
 /// Assemble a list of predicates that would be present on a theoretical
 /// user impl for an object type. These predicates must be checked any time
 /// we assemble a built-in object candidate for an object type, since they
diff --git a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
index 0912e5effa6..1f5ca71dd6f 100644
--- a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
@@ -3,15 +3,15 @@
 
 use rustc_type_ir::fast_reject::DeepRejectCtxt;
 use rustc_type_ir::inherent::*;
+use rustc_type_ir::lang_items::TraitSolverLangItem;
 use rustc_type_ir::{self as ty, Interner, elaborate};
 use tracing::instrument;
 
-use super::assembly::Candidate;
+use super::assembly::{Candidate, structural_traits};
 use crate::delegate::SolverDelegate;
-use crate::solve::assembly::{self};
 use crate::solve::{
     BuiltinImplSource, CandidateSource, Certainty, EvalCtxt, Goal, GoalSource, NoSolution,
-    QueryResult,
+    QueryResult, assembly,
 };
 
 impl<D, I> assembly::GoalKind<D> for ty::HostEffectPredicate<I>
@@ -142,7 +142,7 @@ where
             ty::ImplPolarity::Positive => {}
         };
 
-        if !cx.is_const_impl(impl_def_id) {
+        if !cx.impl_is_const(impl_def_id) {
             return Err(NoSolution);
         }
 
@@ -207,14 +207,7 @@ where
         _ecx: &mut EvalCtxt<'_, D>,
         _goal: Goal<I, Self>,
     ) -> Result<Candidate<I>, NoSolution> {
-        todo!("Copy/Clone is not yet const")
-    }
-
-    fn consider_builtin_pointer_like_candidate(
-        _ecx: &mut EvalCtxt<'_, D>,
-        _goal: Goal<I, Self>,
-    ) -> Result<Candidate<I>, NoSolution> {
-        unreachable!("PointerLike is not const")
+        Err(NoSolution)
     }
 
     fn consider_builtin_fn_ptr_trait_candidate(
@@ -225,11 +218,48 @@ where
     }
 
     fn consider_builtin_fn_trait_candidates(
-        _ecx: &mut EvalCtxt<'_, D>,
-        _goal: Goal<I, Self>,
+        ecx: &mut EvalCtxt<'_, D>,
+        goal: Goal<I, Self>,
         _kind: rustc_type_ir::ClosureKind,
     ) -> Result<Candidate<I>, NoSolution> {
-        todo!("Fn* are not yet const")
+        let cx = ecx.cx();
+
+        let self_ty = goal.predicate.self_ty();
+        let (inputs_and_output, def_id, args) =
+            structural_traits::extract_fn_def_from_const_callable(cx, self_ty)?;
+
+        // A built-in `Fn` impl only holds if the output is sized.
+        // (FIXME: technically we only need to check this if the type is a fn ptr...)
+        let output_is_sized_pred = inputs_and_output.map_bound(|(_, output)| {
+            ty::TraitRef::new(cx, cx.require_lang_item(TraitSolverLangItem::Sized), [output])
+        });
+        let requirements = cx
+            .const_conditions(def_id)
+            .iter_instantiated(cx, args)
+            .map(|trait_ref| {
+                (
+                    GoalSource::ImplWhereBound,
+                    goal.with(cx, trait_ref.to_host_effect_clause(cx, goal.predicate.constness)),
+                )
+            })
+            .chain([(GoalSource::ImplWhereBound, goal.with(cx, output_is_sized_pred))]);
+
+        let pred = inputs_and_output
+            .map_bound(|(inputs, _)| {
+                ty::TraitRef::new(cx, goal.predicate.def_id(), [
+                    goal.predicate.self_ty(),
+                    Ty::new_tup(cx, inputs.as_slice()),
+                ])
+            })
+            .to_host_effect_clause(cx, goal.predicate.constness);
+
+        Self::probe_and_consider_implied_clause(
+            ecx,
+            CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
+            goal,
+            pred,
+            requirements,
+        )
     }
 
     fn consider_builtin_async_fn_trait_candidates(
@@ -314,7 +344,7 @@ where
         _ecx: &mut EvalCtxt<'_, D>,
         _goal: Goal<I, Self>,
     ) -> Result<Candidate<I>, NoSolution> {
-        unreachable!("Destruct is not const")
+        Err(NoSolution)
     }
 
     fn consider_builtin_transmute_candidate(
diff --git a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
index 129744b4db7..6b407640426 100644
--- a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
@@ -363,13 +363,6 @@ where
         panic!("`Copy`/`Clone` does not have an associated type: {:?}", goal);
     }
 
-    fn consider_builtin_pointer_like_candidate(
-        _ecx: &mut EvalCtxt<'_, D>,
-        goal: Goal<I, Self>,
-    ) -> Result<Candidate<I>, NoSolution> {
-        panic!("`PointerLike` does not have an associated type: {:?}", goal);
-    }
-
     fn consider_builtin_fn_ptr_trait_candidate(
         _ecx: &mut EvalCtxt<'_, D>,
         goal: Goal<I, Self>,
@@ -394,6 +387,9 @@ where
                     return ecx.forced_ambiguity(MaybeCause::Ambiguity);
                 }
             };
+
+        // A built-in `Fn` impl only holds if the output is sized.
+        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         let output_is_sized_pred = tupled_inputs_and_output.map_bound(|(_, output)| {
             ty::TraitRef::new(cx, cx.require_lang_item(TraitSolverLangItem::Sized), [output])
         });
@@ -408,8 +404,6 @@ where
             })
             .upcast(cx);
 
-        // A built-in `Fn` impl only holds if the output is sized.
-        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         Self::probe_and_consider_implied_clause(
             ecx,
             CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
@@ -438,6 +432,9 @@ where
                 goal_kind,
                 env_region,
             )?;
+
+        // A built-in `AsyncFn` impl only holds if the output is sized.
+        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         let output_is_sized_pred = tupled_inputs_and_output_and_coroutine.map_bound(
             |AsyncCallableRelevantTypes { output_coroutine_ty: output_ty, .. }| {
                 ty::TraitRef::new(cx, cx.require_lang_item(TraitSolverLangItem::Sized), [output_ty])
@@ -494,8 +491,6 @@ where
             )
             .upcast(cx);
 
-        // A built-in `AsyncFn` impl only holds if the output is sized.
-        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         Self::probe_and_consider_implied_clause(
             ecx,
             CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
diff --git a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
index 5f740590712..ce16258d180 100644
--- a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
@@ -248,32 +248,6 @@ where
         )
     }
 
-    fn consider_builtin_pointer_like_candidate(
-        ecx: &mut EvalCtxt<'_, D>,
-        goal: Goal<I, Self>,
-    ) -> Result<Candidate<I>, NoSolution> {
-        if goal.predicate.polarity != ty::PredicatePolarity::Positive {
-            return Err(NoSolution);
-        }
-
-        let cx = ecx.cx();
-        // But if there are inference variables, we have to wait until it's resolved.
-        if (goal.param_env, goal.predicate.self_ty()).has_non_region_infer() {
-            return ecx.forced_ambiguity(MaybeCause::Ambiguity);
-        }
-
-        if cx.layout_is_pointer_like(
-            ecx.typing_mode(goal.param_env),
-            goal.param_env,
-            goal.predicate.self_ty(),
-        ) {
-            ecx.probe_builtin_trait_candidate(BuiltinImplSource::Misc)
-                .enter(|ecx| ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes))
-        } else {
-            Err(NoSolution)
-        }
-    }
-
     fn consider_builtin_fn_ptr_trait_candidate(
         ecx: &mut EvalCtxt<'_, D>,
         goal: Goal<I, Self>,
@@ -326,6 +300,9 @@ where
                     return ecx.forced_ambiguity(MaybeCause::Ambiguity);
                 }
             };
+
+        // A built-in `Fn` impl only holds if the output is sized.
+        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         let output_is_sized_pred = tupled_inputs_and_output.map_bound(|(_, output)| {
             ty::TraitRef::new(cx, cx.require_lang_item(TraitSolverLangItem::Sized), [output])
         });
@@ -335,8 +312,6 @@ where
                 ty::TraitRef::new(cx, goal.predicate.def_id(), [goal.predicate.self_ty(), inputs])
             })
             .upcast(cx);
-        // A built-in `Fn` impl only holds if the output is sized.
-        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         Self::probe_and_consider_implied_clause(
             ecx,
             CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
@@ -364,6 +339,9 @@ where
                 // This region doesn't matter because we're throwing away the coroutine type
                 Region::new_static(cx),
             )?;
+
+        // A built-in `AsyncFn` impl only holds if the output is sized.
+        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         let output_is_sized_pred = tupled_inputs_and_output_and_coroutine.map_bound(
             |AsyncCallableRelevantTypes { output_coroutine_ty, .. }| {
                 ty::TraitRef::new(cx, cx.require_lang_item(TraitSolverLangItem::Sized), [
@@ -380,8 +358,6 @@ where
                 ])
             })
             .upcast(cx);
-        // A built-in `AsyncFn` impl only holds if the output is sized.
-        // (FIXME: technically we only need to check this if the type is a fn ptr...)
         Self::probe_and_consider_implied_clause(
             ecx,
             CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index 226de65445c..5023e83bd67 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -213,7 +213,7 @@ impl<'psess, 'src> StringReader<'psess, 'src> {
                     let ident = Symbol::intern(lifetime_name);
                     token::Lifetime(ident, IdentIsRaw::No)
                 }
-                rustc_lexer::TokenKind::InvalidIdent | rustc_lexer::TokenKind::InvalidPrefix
+                rustc_lexer::TokenKind::InvalidIdent
                     // Do not recover an identifier with emoji if the codepoint is a confusable
                     // with a recoverable substitution token, like `➖`.
                     if !UNICODE_ARRAY.iter().any(|&(c, _, _)| {
@@ -359,8 +359,7 @@ impl<'psess, 'src> StringReader<'psess, 'src> {
                 rustc_lexer::TokenKind::Percent => token::BinOp(token::Percent),
 
                 rustc_lexer::TokenKind::Unknown
-                | rustc_lexer::TokenKind::InvalidIdent
-                | rustc_lexer::TokenKind::InvalidPrefix => {
+                | rustc_lexer::TokenKind::InvalidIdent => {
                     // Don't emit diagnostics for sequences of the same invalid token
                     if swallow_next_invalid > 0 {
                         swallow_next_invalid -= 1;
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 836511325f4..87069e0b057 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -162,6 +162,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     self.check_rustc_std_internal_symbol(attr, span, target)
                 }
                 [sym::naked, ..] => self.check_naked(hir_id, attr, span, target, attrs),
+                [sym::rustc_as_ptr, ..] => {
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                }
                 [sym::rustc_never_returns_null_ptr, ..] => {
                     self.check_applied_to_fn_or_method(hir_id, attr, span, target)
                 }
diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs
index c6c99852952..9cd95a0b02d 100644
--- a/compiler/rustc_passes/src/liveness.rs
+++ b/compiler/rustc_passes/src/liveness.rs
@@ -468,7 +468,7 @@ const ACC_USE: u32 = 4;
 struct Liveness<'a, 'tcx> {
     ir: &'a mut IrMaps<'tcx>,
     typeck_results: &'a ty::TypeckResults<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     closure_min_captures: Option<&'tcx RootVariableMinCaptureList<'tcx>>,
     successors: IndexVec<LiveNode, Option<LiveNode>>,
     rwu_table: rwu_table::RWUTable,
@@ -491,7 +491,8 @@ struct Liveness<'a, 'tcx> {
 impl<'a, 'tcx> Liveness<'a, 'tcx> {
     fn new(ir: &'a mut IrMaps<'tcx>, body_owner: LocalDefId) -> Liveness<'a, 'tcx> {
         let typeck_results = ir.tcx.typeck(body_owner);
-        let param_env = ir.tcx.param_env(body_owner);
+        // FIXME(#132279): we're in a body here.
+        let typing_env = ty::TypingEnv::non_body_analysis(ir.tcx, body_owner);
         let closure_min_captures = typeck_results.closure_min_captures.get(&body_owner);
         let closure_ln = ir.add_live_node(ClosureNode);
         let exit_ln = ir.add_live_node(ExitNode);
@@ -502,7 +503,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
         Liveness {
             ir,
             typeck_results,
-            param_env,
+            typing_env,
             closure_min_captures,
             successors: IndexVec::from_elem_n(None, num_live_nodes),
             rwu_table: rwu_table::RWUTable::new(num_live_nodes, num_vars),
@@ -1297,7 +1298,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
     fn check_is_ty_uninhabited(&mut self, expr: &Expr<'_>, succ: LiveNode) -> LiveNode {
         let ty = self.typeck_results.expr_ty(expr);
         let m = self.ir.tcx.parent_module(expr.hir_id).to_def_id();
-        if ty.is_inhabited_from(self.ir.tcx, m, ty::TypingEnv::from_param_env(self.param_env)) {
+        if ty.is_inhabited_from(self.ir.tcx, m, self.typing_env) {
             return succ;
         }
         match self.ir.lnks[succ] {
diff --git a/compiler/rustc_smir/src/rustc_smir/context.rs b/compiler/rustc_smir/src/rustc_smir/context.rs
index b19adf321c3..9025b47c422 100644
--- a/compiler/rustc_smir/src/rustc_smir/context.rs
+++ b/compiler/rustc_smir/src/rustc_smir/context.rs
@@ -15,7 +15,7 @@ use rustc_middle::ty::layout::{
 };
 use rustc_middle::ty::print::{with_forced_trimmed_paths, with_no_trimmed_paths};
 use rustc_middle::ty::{
-    GenericPredicates, Instance, List, ParamEnv, ScalarInt, TyCtxt, TypeVisitableExt, ValTree,
+    GenericPredicates, Instance, List, ScalarInt, TyCtxt, TypeVisitableExt, ValTree,
 };
 use rustc_middle::{mir, ty};
 use rustc_span::def_id::LOCAL_CRATE;
@@ -713,7 +713,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         let instance = tables.instances[def];
         let tcx = tables.tcx;
         let result = tcx.const_eval_instance(
-            ParamEnv::reveal_all(),
+            ty::TypingEnv::fully_monomorphized(),
             instance,
             tcx.def_span(instance.def_id()),
         );
diff --git a/compiler/rustc_smir/src/rustc_smir/convert/mir.rs b/compiler/rustc_smir/src/rustc_smir/convert/mir.rs
index 820d8a6be25..fcdf8703b14 100644
--- a/compiler/rustc_smir/src/rustc_smir/convert/mir.rs
+++ b/compiler/rustc_smir/src/rustc_smir/convert/mir.rs
@@ -151,6 +151,10 @@ impl<'tcx> Stable<'tcx> for mir::StatementKind<'tcx> {
             mir::StatementKind::ConstEvalCounter => {
                 stable_mir::mir::StatementKind::ConstEvalCounter
             }
+            // BackwardIncompatibleDropHint has no semantics, so it is translated to Nop.
+            mir::StatementKind::BackwardIncompatibleDropHint { .. } => {
+                stable_mir::mir::StatementKind::Nop
+            }
             mir::StatementKind::Nop => stable_mir::mir::StatementKind::Nop,
         }
     }
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index e4261822040..a2d9859645f 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -316,6 +316,7 @@ symbols! {
         SubdiagMessage,
         Subdiagnostic,
         Sync,
+        SyncUnsafeCell,
         T,
         Target,
         ToOwned,
@@ -409,7 +410,6 @@ symbols! {
         arm,
         arm_target_feature,
         array,
-        as_mut_ptr,
         as_ptr,
         as_ref,
         as_str,
@@ -1655,6 +1655,7 @@ symbols! {
         rustc_allow_const_fn_unstable,
         rustc_allow_incoherent_impl,
         rustc_allowed_through_unstable_modules,
+        rustc_as_ptr,
         rustc_attrs,
         rustc_autodiff,
         rustc_box,
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
index 94f51b87cff..dcbc5f0f76d 100644
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -233,11 +233,11 @@ impl<'tcx> Printer<'tcx> for SymbolMangler<'tcx> {
         let key = self.tcx.def_key(impl_def_id);
         let parent_def_id = DefId { index: key.parent.unwrap(), ..impl_def_id };
 
-        let mut param_env = self.tcx.param_env_reveal_all_normalized(impl_def_id);
+        let mut typing_env = ty::TypingEnv::post_analysis(self.tcx, impl_def_id);
         if !args.is_empty() {
-            param_env = EarlyBinder::bind(param_env).instantiate(self.tcx, args);
+            typing_env.param_env =
+                EarlyBinder::bind(typing_env.param_env).instantiate(self.tcx, args);
         }
-        let typing_env = ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env };
 
         match &mut impl_trait_ref {
             Some(impl_trait_ref) => {
diff --git a/compiler/rustc_target/src/spec/targets/x86_64_win7_windows_msvc.rs b/compiler/rustc_target/src/spec/targets/x86_64_win7_windows_msvc.rs
index 3a3716db350..f42188ec61a 100644
--- a/compiler/rustc_target/src/spec/targets/x86_64_win7_windows_msvc.rs
+++ b/compiler/rustc_target/src/spec/targets/x86_64_win7_windows_msvc.rs
@@ -8,7 +8,7 @@ pub(crate) fn target() -> Target {
     base.vendor = "win7".into();
 
     Target {
-        llvm_target: "x86_64-win7-windows-msvc".into(),
+        llvm_target: "x86_64-pc-windows-msvc".into(),
         metadata: crate::spec::TargetMetadata {
             description: Some("64-bit Windows 7 support".into()),
             tier: Some(3),
diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs
index 8f1c8a29663..43244eb5dcb 100644
--- a/compiler/rustc_trait_selection/src/infer.rs
+++ b/compiler/rustc_trait_selection/src/infer.rs
@@ -32,8 +32,10 @@ impl<'tcx> InferCtxt<'tcx> {
     fn type_is_copy_modulo_regions(&self, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool {
         let ty = self.resolve_vars_if_possible(ty);
 
+        // FIXME(#132279): This should be removed as it causes us to incorrectly
+        // handle opaques in their defining scope.
         if !(param_env, ty).has_infer() {
-            return ty.is_copy_modulo_regions(self.tcx, param_env);
+            return ty.is_copy_modulo_regions(self.tcx, self.typing_env(param_env));
         }
 
         let copy_def_id = self.tcx.require_lang_item(LangItem::Copy, None);
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 103f7c76a86..fac0414d714 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -9,7 +9,6 @@ use rustc_data_structures::unord::UnordSet;
 use rustc_infer::infer::DefineOpaqueTypes;
 use rustc_middle::ty::{Region, RegionVid};
 use tracing::debug;
-use ty::TypingMode;
 
 use super::*;
 use crate::errors::UnableToConstructConstantValue;
@@ -71,7 +70,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
     pub fn find_auto_trait_generics<A>(
         &self,
         ty: Ty<'tcx>,
-        orig_env: ty::ParamEnv<'tcx>,
+        typing_env: ty::TypingEnv<'tcx>,
         trait_did: DefId,
         mut auto_trait_callback: impl FnMut(AutoTraitInfo<'tcx>) -> A,
     ) -> AutoTraitResult<A> {
@@ -79,7 +78,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
 
         let trait_ref = ty::TraitRef::new(tcx, trait_did, [ty]);
 
-        let infcx = tcx.infer_ctxt().build(TypingMode::non_body_analysis());
+        let (infcx, orig_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
         let mut selcx = SelectionContext::new(&infcx);
         for polarity in [ty::PredicatePolarity::Positive, ty::PredicatePolarity::Negative] {
             let result = selcx.select(&Obligation::new(
@@ -89,17 +88,13 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                 ty::TraitPredicate { trait_ref, polarity },
             ));
             if let Ok(Some(ImplSource::UserDefined(_))) = result {
-                debug!(
-                    "find_auto_trait_generics({:?}): \
-                 manual impl found, bailing out",
-                    trait_ref
-                );
+                debug!("find_auto_trait_generics({trait_ref:?}): manual impl found, bailing out");
                 // If an explicit impl exists, it always takes priority over an auto impl
                 return AutoTraitResult::ExplicitImpl;
             }
         }
 
-        let infcx = tcx.infer_ctxt().build(TypingMode::non_body_analysis());
+        let (infcx, orig_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
         let mut fresh_preds = FxIndexSet::default();
 
         // Due to the way projections are handled by SelectionContext, we need to run
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index c0603c06d42..80cef690028 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -698,8 +698,8 @@ fn replace_param_and_infer_args_with_placeholder<'tcx>(
 /// used during analysis.
 pub fn impossible_predicates<'tcx>(tcx: TyCtxt<'tcx>, predicates: Vec<ty::Clause<'tcx>>) -> bool {
     debug!("impossible_predicates(predicates={:?})", predicates);
-    let infcx = tcx.infer_ctxt().build(TypingMode::PostAnalysis);
-    let param_env = ty::ParamEnv::reveal_all();
+    let (infcx, param_env) =
+        tcx.infer_ctxt().build_with_typing_env(ty::TypingEnv::fully_monomorphized());
     let ocx = ObligationCtxt::new(&infcx);
     let predicates = ocx.normalize(&ObligationCause::dummy(), param_env, predicates);
     for predicate in predicates {
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index 1e0c487c4d4..345e1cc31f3 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -111,8 +111,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 self.assemble_candidates_for_transmutability(obligation, &mut candidates);
             } else if tcx.is_lang_item(def_id, LangItem::Tuple) {
                 self.assemble_candidate_for_tuple(obligation, &mut candidates);
-            } else if tcx.is_lang_item(def_id, LangItem::PointerLike) {
-                self.assemble_candidate_for_pointer_like(obligation, &mut candidates);
             } else if tcx.is_lang_item(def_id, LangItem::FnPtrTrait) {
                 self.assemble_candidates_for_fn_ptr_trait(obligation, &mut candidates);
             } else {
@@ -1216,35 +1214,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         }
     }
 
-    fn assemble_candidate_for_pointer_like(
-        &mut self,
-        obligation: &PolyTraitObligation<'tcx>,
-        candidates: &mut SelectionCandidateSet<'tcx>,
-    ) {
-        // The regions of a type don't affect the size of the type
-        let tcx = self.tcx();
-        let self_ty = tcx.instantiate_bound_regions_with_erased(obligation.predicate.self_ty());
-
-        // But if there are inference variables, we have to wait until it's resolved.
-        if (obligation.param_env, self_ty).has_non_region_infer() {
-            candidates.ambiguous = true;
-            return;
-        }
-
-        // We should erase regions from both the param-env and type, since both
-        // may have infer regions. Specifically, after canonicalizing and instantiating,
-        // early bound regions turn into region vars in both the new and old solver.
-        let key = self.infcx.pseudo_canonicalize_query(
-            tcx.erase_regions(obligation.param_env),
-            tcx.erase_regions(self_ty),
-        );
-        if let Ok(layout) = tcx.layout_of(key)
-            && layout.layout.is_pointer_like(&tcx.data_layout)
-        {
-            candidates.vec.push(BuiltinCandidate { has_nested: false });
-        }
-    }
-
     fn assemble_candidates_for_fn_ptr_trait(
         &mut self,
         obligation: &PolyTraitObligation<'tcx>,
diff --git a/compiler/rustc_trait_selection/src/traits/vtable.rs b/compiler/rustc_trait_selection/src/traits/vtable.rs
index 8352d31d13a..b5bc8364c7b 100644
--- a/compiler/rustc_trait_selection/src/traits/vtable.rs
+++ b/compiler/rustc_trait_selection/src/traits/vtable.rs
@@ -9,8 +9,7 @@ use rustc_infer::traits::util::PredicateSet;
 use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{
-    self, GenericArgs, GenericParamDefKind, Ty, TyCtxt, TypeVisitableExt, TypingMode, Upcast,
-    VtblEntry,
+    self, GenericArgs, GenericParamDefKind, Ty, TyCtxt, TypeVisitableExt, Upcast, VtblEntry,
 };
 use rustc_span::{DUMMY_SP, Span, sym};
 use smallvec::{SmallVec, smallvec};
@@ -442,8 +441,8 @@ fn trait_refs_are_compatible<'tcx>(
         return false;
     }
 
-    let infcx = tcx.infer_ctxt().build(TypingMode::PostAnalysis);
-    let param_env = ty::ParamEnv::reveal_all();
+    let (infcx, param_env) =
+        tcx.infer_ctxt().build_with_typing_env(ty::TypingEnv::fully_monomorphized());
     let ocx = ObligationCtxt::new(&infcx);
     let hr_source_principal =
         ocx.normalize(&ObligationCause::dummy(), param_env, hr_vtable_principal);
diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index e2283383196..a5a9125c8b5 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -397,7 +397,7 @@ fn adjust_for_rust_scalar<'tcx>(
             Some(kind)
         } else if let Some(pointee) = drop_target_pointee {
             // The argument to `drop_in_place` is semantically equivalent to a mutable reference.
-            Some(PointerKind::MutableRef { unpin: pointee.is_unpin(tcx, cx.typing_env.param_env) })
+            Some(PointerKind::MutableRef { unpin: pointee.is_unpin(tcx, cx.typing_env) })
         } else {
             None
         };
diff --git a/compiler/rustc_ty_utils/src/common_traits.rs b/compiler/rustc_ty_utils/src/common_traits.rs
index c26b41d8960..2157ab3c402 100644
--- a/compiler/rustc_ty_utils/src/common_traits.rs
+++ b/compiler/rustc_ty_utils/src/common_traits.rs
@@ -3,34 +3,33 @@
 use rustc_hir::lang_items::LangItem;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::query::Providers;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypingMode};
+use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_trait_selection::traits;
 
-fn is_copy_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+fn is_copy_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
     is_item_raw(tcx, query, LangItem::Copy)
 }
 
-fn is_sized_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+fn is_sized_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
     is_item_raw(tcx, query, LangItem::Sized)
 }
 
-fn is_freeze_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+fn is_freeze_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
     is_item_raw(tcx, query, LangItem::Freeze)
 }
 
-fn is_unpin_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
+fn is_unpin_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>) -> bool {
     is_item_raw(tcx, query, LangItem::Unpin)
 }
 
 fn is_item_raw<'tcx>(
     tcx: TyCtxt<'tcx>,
-    query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>,
+    query: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>,
     item: LangItem,
 ) -> bool {
-    let (param_env, ty) = query.into_parts();
+    let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(query.typing_env);
     let trait_def_id = tcx.require_lang_item(item, None);
-    let infcx = tcx.infer_ctxt().build(TypingMode::from_param_env(param_env));
-    traits::type_known_to_meet_bound_modulo_regions(&infcx, param_env, ty, trait_def_id)
+    traits::type_known_to_meet_bound_modulo_regions(&infcx, param_env, query.value, trait_def_id)
 }
 
 pub(crate) fn provide(providers: &mut Providers) {
diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs
index 84fc03a8f13..29fc92e1f2f 100644
--- a/compiler/rustc_ty_utils/src/instance.rs
+++ b/compiler/rustc_ty_utils/src/instance.rs
@@ -13,7 +13,7 @@ use rustc_span::sym;
 use rustc_trait_selection::traits;
 use rustc_type_ir::ClosureKind;
 use tracing::debug;
-use traits::{Reveal, translate_args};
+use traits::translate_args;
 
 use crate::errors::UnexpectedFnPtrAssociatedItem;
 
@@ -133,18 +133,6 @@ fn resolve_associated_item<'tcx>(
                     bug!("{:?} not found in {:?}", trait_item_id, impl_data.impl_def_id);
                 });
 
-            let typing_env = typing_env.with_reveal_all_normalized(tcx);
-            let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
-            let args = rcvr_args.rebase_onto(tcx, trait_def_id, impl_data.args);
-            let args = translate_args(
-                &infcx,
-                param_env,
-                impl_data.impl_def_id,
-                args,
-                leaf_def.defining_node,
-            );
-            let args = infcx.tcx.erase_regions(args);
-
             // Since this is a trait item, we need to see if the item is either a trait default item
             // or a specialization because we can't resolve those unless we can `Reveal::All`.
             // NOTE: This should be kept in sync with the similar code in
@@ -157,16 +145,28 @@ fn resolve_associated_item<'tcx>(
                 // and the obligation is monomorphic, otherwise passes such as
                 // transmute checking and polymorphic MIR optimizations could
                 // get a result which isn't correct for all monomorphizations.
-                if param_env.reveal() == Reveal::All {
-                    !trait_ref.still_further_specializable()
-                } else {
-                    false
+                match typing_env.typing_mode {
+                    ty::TypingMode::Coherence
+                    | ty::TypingMode::Analysis { defining_opaque_types: _ } => false,
+                    ty::TypingMode::PostAnalysis => !trait_ref.still_further_specializable(),
                 }
             };
             if !eligible {
                 return Ok(None);
             }
 
+            let typing_env = typing_env.with_reveal_all_normalized(tcx);
+            let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
+            let args = rcvr_args.rebase_onto(tcx, trait_def_id, impl_data.args);
+            let args = translate_args(
+                &infcx,
+                param_env,
+                impl_data.impl_def_id,
+                args,
+                leaf_def.defining_node,
+            );
+            let args = infcx.tcx.erase_regions(args);
+
             // HACK: We may have overlapping `dyn Trait` built-in impls and
             // user-provided blanket impls. Detect that case here, and return
             // ambiguity.
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index 02ee3f32915..092e140a600 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -105,7 +105,7 @@ fn map_error<'tcx>(
             // This is sometimes not a compile error if there are trivially false where clauses.
             // See `tests/ui/layout/trivial-bounds-sized.rs` for an example.
             assert!(field.layout.is_unsized(), "invalid layout error {err:#?}");
-            if !field.ty.is_sized(cx.tcx(), cx.typing_env.param_env) {
+            if !field.ty.is_sized(cx.tcx(), cx.typing_env) {
                 cx.tcx().dcx().delayed_bug(format!(
                     "encountered unexpected unsized field in layout of {ty:?}: {field:#?}"
                 ));
@@ -236,7 +236,7 @@ fn layout_of_uncached<'tcx>(
             }
 
             let pointee = tcx.normalize_erasing_regions(cx.typing_env, pointee);
-            if pointee.is_sized(tcx, cx.typing_env.param_env) {
+            if pointee.is_sized(tcx, cx.typing_env) {
                 return Ok(tcx.mk_layout(LayoutData::scalar(cx, data_ptr)));
             }
 
@@ -594,8 +594,8 @@ fn layout_of_uncached<'tcx>(
 
             let maybe_unsized = def.is_struct()
                 && def.non_enum_variant().tail_opt().is_some_and(|last_field| {
-                    let param_env = tcx.param_env(def.did());
-                    !tcx.type_of(last_field.did).instantiate_identity().is_sized(tcx, param_env)
+                    let typing_env = ty::TypingEnv::post_analysis(tcx, def.did());
+                    !tcx.type_of(last_field.did).instantiate_identity().is_sized(tcx, typing_env)
                 });
 
             let layout = cx
@@ -620,11 +620,7 @@ fn layout_of_uncached<'tcx>(
             // If the struct tail is sized and can be unsized, check that unsizing doesn't move the fields around.
             if cfg!(debug_assertions)
                 && maybe_unsized
-                && def
-                    .non_enum_variant()
-                    .tail()
-                    .ty(tcx, args)
-                    .is_sized(tcx, cx.typing_env.param_env)
+                && def.non_enum_variant().tail().ty(tcx, args).is_sized(tcx, cx.typing_env)
             {
                 let mut variants = variants;
                 let tail_replacement = cx.layout_of(Ty::new_slice(tcx, tcx.types.u8)).unwrap();
diff --git a/compiler/rustc_ty_utils/src/needs_drop.rs b/compiler/rustc_ty_utils/src/needs_drop.rs
index d462dbd9416..469a4ac3e41 100644
--- a/compiler/rustc_ty_utils/src/needs_drop.rs
+++ b/compiler/rustc_ty_utils/src/needs_drop.rs
@@ -8,7 +8,7 @@ use rustc_middle::ty::util::{AlwaysRequiresDrop, needs_drop_components};
 use rustc_middle::ty::{self, EarlyBinder, GenericArgsRef, Ty, TyCtxt};
 use rustc_session::Limit;
 use rustc_span::sym;
-use tracing::debug;
+use tracing::{debug, instrument};
 
 use crate::errors::NeedsDropOverflow;
 
@@ -23,7 +23,7 @@ fn needs_drop_raw<'tcx>(
     // needs drop.
     let adt_has_dtor =
         |adt_def: ty::AdtDef<'tcx>| adt_def.destructor(tcx).map(|_| DtorType::Significant);
-    let res = drop_tys_helper(tcx, query.value, query.typing_env, adt_has_dtor, false)
+    let res = drop_tys_helper(tcx, query.value, query.typing_env, adt_has_dtor, false, false)
         .filter(filter_array_elements(tcx, query.typing_env))
         .next()
         .is_some();
@@ -41,7 +41,7 @@ fn needs_async_drop_raw<'tcx>(
     // it needs async drop.
     let adt_has_async_dtor =
         |adt_def: ty::AdtDef<'tcx>| adt_def.async_destructor(tcx).map(|_| DtorType::Significant);
-    let res = drop_tys_helper(tcx, query.value, query.typing_env, adt_has_async_dtor, false)
+    let res = drop_tys_helper(tcx, query.value, query.typing_env, adt_has_async_dtor, false, false)
         .filter(filter_array_elements(tcx, query.typing_env))
         .next()
         .is_some();
@@ -77,6 +77,7 @@ fn has_significant_drop_raw<'tcx>(
         query.typing_env,
         adt_consider_insignificant_dtor(tcx),
         true,
+        false,
     )
     .filter(filter_array_elements(tcx, query.typing_env))
     .next()
@@ -88,8 +89,8 @@ fn has_significant_drop_raw<'tcx>(
 struct NeedsDropTypes<'tcx, F> {
     tcx: TyCtxt<'tcx>,
     typing_env: ty::TypingEnv<'tcx>,
-    // Whether to reveal coroutine witnesses, this is set
-    // to `false` unless we compute `needs_drop` for a coroutine witness.
+    /// Whether to reveal coroutine witnesses, this is set
+    /// to `false` unless we compute `needs_drop` for a coroutine witness.
     reveal_coroutine_witnesses: bool,
     query_ty: Ty<'tcx>,
     seen_tys: FxHashSet<Ty<'tcx>>,
@@ -100,6 +101,9 @@ struct NeedsDropTypes<'tcx, F> {
     unchecked_tys: Vec<(Ty<'tcx>, usize)>,
     recursion_limit: Limit,
     adt_components: F,
+    /// Set this to true if an exhaustive list of types involved in
+    /// drop obligation is requested.
+    exhaustive: bool,
 }
 
 impl<'tcx, F> NeedsDropTypes<'tcx, F> {
@@ -107,6 +111,7 @@ impl<'tcx, F> NeedsDropTypes<'tcx, F> {
         tcx: TyCtxt<'tcx>,
         typing_env: ty::TypingEnv<'tcx>,
         ty: Ty<'tcx>,
+        exhaustive: bool,
         adt_components: F,
     ) -> Self {
         let mut seen_tys = FxHashSet::default();
@@ -114,14 +119,22 @@ impl<'tcx, F> NeedsDropTypes<'tcx, F> {
         Self {
             tcx,
             typing_env,
-            reveal_coroutine_witnesses: false,
+            reveal_coroutine_witnesses: exhaustive,
             seen_tys,
             query_ty: ty,
             unchecked_tys: vec![(ty, 0)],
             recursion_limit: tcx.recursion_limit(),
             adt_components,
+            exhaustive,
         }
     }
+
+    /// Called when `ty` is found to always require drop.
+    /// If the exhaustive flag is true, then `Ok(ty)` is returned like any other type.
+    /// Otherwise, `Err(AlwaysRequireDrop)` is returned, which will cause iteration to abort.
+    fn always_drop_component(&self, ty: Ty<'tcx>) -> NeedsDropResult<Ty<'tcx>> {
+        if self.exhaustive { Ok(ty) } else { Err(AlwaysRequiresDrop) }
+    }
 }
 
 impl<'tcx, F, I> Iterator for NeedsDropTypes<'tcx, F>
@@ -131,19 +144,22 @@ where
 {
     type Item = NeedsDropResult<Ty<'tcx>>;
 
+    #[instrument(level = "debug", skip(self), ret)]
     fn next(&mut self) -> Option<NeedsDropResult<Ty<'tcx>>> {
         let tcx = self.tcx;
 
         while let Some((ty, level)) = self.unchecked_tys.pop() {
+            debug!(?ty, "needs_drop_components: inspect");
             if !self.recursion_limit.value_within_limit(level) {
                 // Not having a `Span` isn't great. But there's hopefully some other
                 // recursion limit error as well.
+                debug!("needs_drop_components: recursion limit exceeded");
                 tcx.dcx().emit_err(NeedsDropOverflow { query_ty: self.query_ty });
-                return Some(Err(AlwaysRequiresDrop));
+                return Some(self.always_drop_component(ty));
             }
 
             let components = match needs_drop_components(tcx, ty) {
-                Err(e) => return Some(Err(e)),
+                Err(AlwaysRequiresDrop) => return Some(self.always_drop_component(ty)),
                 Ok(components) => components,
             };
             debug!("needs_drop_components({:?}) = {:?}", ty, components);
@@ -171,7 +187,7 @@ where
                         if self.reveal_coroutine_witnesses {
                             queue_type(self, args.as_coroutine().witness());
                         } else {
-                            return Some(Err(AlwaysRequiresDrop));
+                            return Some(self.always_drop_component(ty));
                         }
                     }
                     ty::CoroutineWitness(def_id, args) => {
@@ -186,7 +202,7 @@ where
                         }
                     }
 
-                    _ if component.is_copy_modulo_regions(tcx, self.typing_env.param_env) => (),
+                    _ if component.is_copy_modulo_regions(tcx, self.typing_env) => {}
 
                     ty::Closure(_, args) => {
                         for upvar in args.as_closure().upvar_tys() {
@@ -205,7 +221,9 @@ where
                     // impl then check whether the field types need `Drop`.
                     ty::Adt(adt_def, args) => {
                         let tys = match (self.adt_components)(adt_def, args) {
-                            Err(e) => return Some(Err(e)),
+                            Err(AlwaysRequiresDrop) => {
+                                return Some(self.always_drop_component(ty));
+                            }
                             Ok(tys) => tys,
                         };
                         for required_ty in tys {
@@ -230,7 +248,8 @@ where
                     }
 
                     ty::Foreign(_) | ty::Dynamic(..) => {
-                        return Some(Err(AlwaysRequiresDrop));
+                        debug!("needs_drop_components: foreign or dynamic");
+                        return Some(self.always_drop_component(ty));
                     }
 
                     ty::Bool
@@ -280,6 +299,7 @@ fn drop_tys_helper<'tcx>(
     typing_env: ty::TypingEnv<'tcx>,
     adt_has_dtor: impl Fn(ty::AdtDef<'tcx>) -> Option<DtorType>,
     only_significant: bool,
+    exhaustive: bool,
 ) -> impl Iterator<Item = NeedsDropResult<Ty<'tcx>>> {
     fn with_query_cache<'tcx>(
         tcx: TyCtxt<'tcx>,
@@ -343,7 +363,7 @@ fn drop_tys_helper<'tcx>(
         .map(|v| v.into_iter())
     };
 
-    NeedsDropTypes::new(tcx, typing_env, ty, adt_components)
+    NeedsDropTypes::new(tcx, typing_env, ty, exhaustive, adt_components)
 }
 
 fn adt_consider_insignificant_dtor<'tcx>(
@@ -384,6 +404,7 @@ fn adt_drop_tys<'tcx>(
         ty::TypingEnv::non_body_analysis(tcx, def_id),
         adt_has_dtor,
         false,
+        false,
     )
     .collect::<Result<Vec<_>, _>>()
     .map(|components| tcx.mk_type_list(&components))
@@ -401,11 +422,31 @@ fn adt_significant_drop_tys(
         ty::TypingEnv::non_body_analysis(tcx, def_id),
         adt_consider_insignificant_dtor(tcx),
         true,
+        false,
     )
     .collect::<Result<Vec<_>, _>>()
     .map(|components| tcx.mk_type_list(&components))
 }
 
+#[instrument(level = "debug", skip(tcx), ret)]
+fn list_significant_drop_tys<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>,
+) -> &'tcx ty::List<Ty<'tcx>> {
+    tcx.mk_type_list(
+        &drop_tys_helper(
+            tcx,
+            ty.value,
+            ty::TypingEnv { typing_mode: ty::TypingMode::PostAnalysis, param_env: ty.param_env },
+            adt_consider_insignificant_dtor(tcx),
+            true,
+            true,
+        )
+        .filter_map(|res| res.ok())
+        .collect::<Vec<_>>(),
+    )
+}
+
 pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers {
         needs_drop_raw,
@@ -413,6 +454,7 @@ pub(crate) fn provide(providers: &mut Providers) {
         has_significant_drop_raw,
         adt_drop_tys,
         adt_significant_drop_tys,
+        list_significant_drop_tys,
         ..*providers
     };
 }
diff --git a/compiler/rustc_type_ir/src/infer_ctxt.rs b/compiler/rustc_type_ir/src/infer_ctxt.rs
index 105ae76708b..b01d3dc5269 100644
--- a/compiler/rustc_type_ir/src/infer_ctxt.rs
+++ b/compiler/rustc_type_ir/src/infer_ctxt.rs
@@ -4,10 +4,8 @@ use rustc_macros::{HashStable_NoContext, TyDecodable, TyEncodable};
 use rustc_type_ir_macros::{TypeFoldable_Generic, TypeVisitable_Generic};
 
 use crate::fold::TypeFoldable;
-use crate::inherent::*;
 use crate::relate::RelateResult;
 use crate::relate::combine::PredicateEmittingRelation;
-use crate::solve::Reveal;
 use crate::{self as ty, Interner};
 
 /// The current typing mode of an inference context. We unfortunately have some
@@ -58,18 +56,6 @@ impl<I: Interner> TypingMode<I> {
     pub fn analysis_in_body(cx: I, body_def_id: I::LocalDefId) -> TypingMode<I> {
         TypingMode::Analysis { defining_opaque_types: cx.opaque_types_defined_by(body_def_id) }
     }
-
-    /// FIXME(#132279): Using this function is questionable as the `param_env`
-    /// does not track `defining_opaque_types` and whether we're in coherence mode.
-    /// Many uses of this function should also use a not-yet implemented typing mode
-    /// which reveals already defined opaque types in the future. This function will
-    /// get completely removed at some point.
-    pub fn from_param_env(param_env: I::ParamEnv) -> TypingMode<I> {
-        match param_env.reveal() {
-            Reveal::UserFacing => TypingMode::non_body_analysis(),
-            Reveal::All => TypingMode::PostAnalysis,
-        }
-    }
 }
 
 pub trait InferCtxtLike: Sized {
diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs
index f988f003c0f..4e1715dbd0f 100644
--- a/compiler/rustc_type_ir/src/interner.rs
+++ b/compiler/rustc_type_ir/src/interner.rs
@@ -13,7 +13,7 @@ use crate::lang_items::TraitSolverLangItem;
 use crate::relate::Relate;
 use crate::solve::{CanonicalInput, ExternalConstraintsData, PredefinedOpaquesData, QueryResult};
 use crate::visit::{Flags, TypeSuperVisitable, TypeVisitable};
-use crate::{self as ty, TypingMode, search_graph};
+use crate::{self as ty, search_graph};
 
 pub trait Interner:
     Sized
@@ -223,7 +223,8 @@ pub trait Interner:
         def_id: Self::DefId,
     ) -> ty::EarlyBinder<Self, impl IntoIterator<Item = (Self::Clause, Self::Span)>>;
 
-    fn is_const_impl(self, def_id: Self::DefId) -> bool;
+    fn impl_is_const(self, def_id: Self::DefId) -> bool;
+    fn fn_is_const(self, def_id: Self::DefId) -> bool;
     fn const_conditions(
         self,
         def_id: Self::DefId,
@@ -277,13 +278,6 @@ pub trait Interner:
     fn coroutine_is_gen(self, coroutine_def_id: Self::DefId) -> bool;
     fn coroutine_is_async_gen(self, coroutine_def_id: Self::DefId) -> bool;
 
-    fn layout_is_pointer_like(
-        self,
-        typing_mode: TypingMode<Self>,
-        param_env: Self::ParamEnv,
-        ty: Self::Ty,
-    ) -> bool;
-
     type UnsizingParams: Deref<Target = BitSet<u32>>;
     fn unsizing_params_for_adt(self, adt_def_id: Self::DefId) -> Self::UnsizingParams;
 
diff --git a/compiler/rustc_type_ir/src/lang_items.rs b/compiler/rustc_type_ir/src/lang_items.rs
index d6ca22a90a4..df43346065d 100644
--- a/compiler/rustc_type_ir/src/lang_items.rs
+++ b/compiler/rustc_type_ir/src/lang_items.rs
@@ -31,7 +31,6 @@ pub enum TraitSolverLangItem {
     Metadata,
     Option,
     PointeeTrait,
-    PointerLike,
     Poll,
     Sized,
     TransmuteTrait,
diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs
index bb6dd1d2d30..ee60ec0fbac 100644
--- a/library/alloc/src/boxed.rs
+++ b/library/alloc/src/boxed.rs
@@ -191,6 +191,8 @@ use core::error::{self, Error};
 use core::fmt;
 use core::future::Future;
 use core::hash::{Hash, Hasher};
+#[cfg(not(bootstrap))]
+use core::marker::PointerLike;
 use core::marker::{Tuple, Unsize};
 use core::mem::{self, SizedTypeProperties};
 use core::ops::{
@@ -1500,6 +1502,7 @@ impl<T: ?Sized, A: Allocator> Box<T, A> {
     /// [`as_ptr`]: Self::as_ptr
     #[unstable(feature = "box_as_ptr", issue = "129090")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline]
     pub fn as_mut_ptr(b: &mut Self) -> *mut T {
         // This is a primitive deref, not going through `DerefMut`, and therefore not materializing
@@ -1548,6 +1551,7 @@ impl<T: ?Sized, A: Allocator> Box<T, A> {
     /// [`as_ptr`]: Self::as_ptr
     #[unstable(feature = "box_as_ptr", issue = "129090")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline]
     pub fn as_ptr(b: &Self) -> *const T {
         // This is a primitive deref, not going through `DerefMut`, and therefore not materializing
@@ -2129,3 +2133,7 @@ impl<E: Error> Error for Box<E> {
         Error::provide(&**self, request);
     }
 }
+
+#[cfg(not(bootstrap))]
+#[unstable(feature = "pointer_like_trait", issue = "none")]
+impl<T> PointerLike for Box<T> {}
diff --git a/library/alloc/src/collections/vec_deque/iter.rs b/library/alloc/src/collections/vec_deque/iter.rs
index 6922ea9b79b..d3dbd10c863 100644
--- a/library/alloc/src/collections/vec_deque/iter.rs
+++ b/library/alloc/src/collections/vec_deque/iter.rs
@@ -19,6 +19,40 @@ impl<'a, T> Iter<'a, T> {
     pub(super) fn new(i1: slice::Iter<'a, T>, i2: slice::Iter<'a, T>) -> Self {
         Self { i1, i2 }
     }
+
+    /// Views the underlying data as a pair of subslices of the original data.
+    ///
+    /// The slices contain, in order, the contents of the deque not yet yielded
+    /// by the iterator.
+    ///
+    /// This has the same lifetime as the original `VecDeque`, and so the
+    /// iterator can continue to be used while this exists.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(vec_deque_iter_as_slices)]
+    ///
+    /// use std::collections::VecDeque;
+    ///
+    /// let mut deque = VecDeque::new();
+    /// deque.push_back(0);
+    /// deque.push_back(1);
+    /// deque.push_back(2);
+    /// deque.push_front(10);
+    /// deque.push_front(9);
+    /// deque.push_front(8);
+    ///
+    /// let mut iter = deque.iter();
+    /// iter.next();
+    /// iter.next_back();
+    ///
+    /// assert_eq!(iter.as_slices(), (&[9, 10][..], &[0, 1][..]));
+    /// ```
+    #[unstable(feature = "vec_deque_iter_as_slices", issue = "123947")]
+    pub fn as_slices(&self) -> (&'a [T], &'a [T]) {
+        (self.i1.as_slice(), self.i2.as_slice())
+    }
 }
 
 #[stable(feature = "collection_debug", since = "1.17.0")]
diff --git a/library/alloc/src/collections/vec_deque/iter_mut.rs b/library/alloc/src/collections/vec_deque/iter_mut.rs
index 84b74109580..0c5f06e752b 100644
--- a/library/alloc/src/collections/vec_deque/iter_mut.rs
+++ b/library/alloc/src/collections/vec_deque/iter_mut.rs
@@ -19,6 +19,113 @@ impl<'a, T> IterMut<'a, T> {
     pub(super) fn new(i1: slice::IterMut<'a, T>, i2: slice::IterMut<'a, T>) -> Self {
         Self { i1, i2 }
     }
+
+    /// Views the underlying data as a pair of subslices of the original data.
+    ///
+    /// The slices contain, in order, the contents of the deque not yet yielded
+    /// by the iterator.
+    ///
+    /// To avoid creating `&mut` references that alias, this is forced to
+    /// consume the iterator.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(vec_deque_iter_as_slices)]
+    ///
+    /// use std::collections::VecDeque;
+    ///
+    /// let mut deque = VecDeque::new();
+    /// deque.push_back(0);
+    /// deque.push_back(1);
+    /// deque.push_back(2);
+    /// deque.push_front(10);
+    /// deque.push_front(9);
+    /// deque.push_front(8);
+    ///
+    /// let mut iter = deque.iter_mut();
+    /// iter.next();
+    /// iter.next_back();
+    ///
+    /// let slices = iter.into_slices();
+    /// slices.0[0] = 42;
+    /// slices.1[0] = 24;
+    /// assert_eq!(deque.as_slices(), (&[8, 42, 10][..], &[24, 1, 2][..]));
+    /// ```
+    #[unstable(feature = "vec_deque_iter_as_slices", issue = "123947")]
+    pub fn into_slices(self) -> (&'a mut [T], &'a mut [T]) {
+        (self.i1.into_slice(), self.i2.into_slice())
+    }
+
+    /// Views the underlying data as a pair of subslices of the original data.
+    ///
+    /// The slices contain, in order, the contents of the deque not yet yielded
+    /// by the iterator.
+    ///
+    /// To avoid creating `&mut [T]` references that alias, the returned slices
+    /// borrow their lifetimes from the iterator the method is applied on.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(vec_deque_iter_as_slices)]
+    ///
+    /// use std::collections::VecDeque;
+    ///
+    /// let mut deque = VecDeque::new();
+    /// deque.push_back(0);
+    /// deque.push_back(1);
+    /// deque.push_back(2);
+    /// deque.push_front(10);
+    /// deque.push_front(9);
+    /// deque.push_front(8);
+    ///
+    /// let mut iter = deque.iter_mut();
+    /// iter.next();
+    /// iter.next_back();
+    ///
+    /// assert_eq!(iter.as_slices(), (&[9, 10][..], &[0, 1][..]));
+    /// ```
+    #[unstable(feature = "vec_deque_iter_as_slices", issue = "123947")]
+    pub fn as_slices(&self) -> (&[T], &[T]) {
+        (self.i1.as_slice(), self.i2.as_slice())
+    }
+
+    /// Views the underlying data as a pair of subslices of the original data.
+    ///
+    /// The slices contain, in order, the contents of the deque not yet yielded
+    /// by the iterator.
+    ///
+    /// To avoid creating `&mut [T]` references that alias, the returned slices
+    /// borrow their lifetimes from the iterator the method is applied on.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(vec_deque_iter_as_slices)]
+    ///
+    /// use std::collections::VecDeque;
+    ///
+    /// let mut deque = VecDeque::new();
+    /// deque.push_back(0);
+    /// deque.push_back(1);
+    /// deque.push_back(2);
+    /// deque.push_front(10);
+    /// deque.push_front(9);
+    /// deque.push_front(8);
+    ///
+    /// let mut iter = deque.iter_mut();
+    /// iter.next();
+    /// iter.next_back();
+    ///
+    /// iter.as_mut_slices().0[0] = 42;
+    /// iter.as_mut_slices().1[0] = 24;
+    /// assert_eq!(deque.as_slices(), (&[8, 42, 10][..], &[24, 1, 2][..]));
+    /// ```
+    #[unstable(feature = "vec_deque_iter_as_slices", issue = "123947")]
+    pub fn as_mut_slices(&mut self) -> (&mut [T], &mut [T]) {
+        (self.i1.as_mut_slice(), self.i2.as_mut_slice())
+    }
 }
 
 #[stable(feature = "collection_debug", since = "1.17.0")]
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index dd9dfa3f5e2..041ff37897f 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -136,6 +136,7 @@
 #![feature(panic_internals)]
 #![feature(pattern)]
 #![feature(pin_coerce_unsized_trait)]
+#![feature(pointer_like_trait)]
 #![feature(ptr_internals)]
 #![feature(ptr_metadata)]
 #![feature(ptr_sub_ptr)]
@@ -143,6 +144,7 @@
 #![feature(sized_type_properties)]
 #![feature(slice_from_ptr_range)]
 #![feature(slice_index_methods)]
+#![feature(slice_iter_mut_as_mut_slice)]
 #![feature(slice_ptr_get)]
 #![feature(slice_range)]
 #![feature(std_internals)]
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 07a1bd49321..990b7e8f761 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -1662,6 +1662,7 @@ impl<T, A: Allocator> Vec<T, A> {
     #[stable(feature = "vec_as_ptr", since = "1.37.0")]
     #[rustc_const_unstable(feature = "const_vec_string_slice", issue = "129041")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline]
     pub const fn as_ptr(&self) -> *const T {
         // We shadow the slice method of the same name to avoid going through
@@ -1724,6 +1725,7 @@ impl<T, A: Allocator> Vec<T, A> {
     #[stable(feature = "vec_as_ptr", since = "1.37.0")]
     #[rustc_const_unstable(feature = "const_vec_string_slice", issue = "129041")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline]
     pub const fn as_mut_ptr(&mut self) -> *mut T {
         // We shadow the slice method of the same name to avoid going through
diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs
index 1a461987c76..bfd2a71f97b 100644
--- a/library/core/src/cell.rs
+++ b/library/core/src/cell.rs
@@ -587,6 +587,7 @@ impl<T: ?Sized> Cell<T> {
     #[inline]
     #[stable(feature = "cell_as_ptr", since = "1.12.0")]
     #[rustc_const_stable(feature = "const_cell_as_ptr", since = "1.32.0")]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[rustc_never_returns_null_ptr]
     pub const fn as_ptr(&self) -> *mut T {
         self.value.get()
@@ -1149,6 +1150,7 @@ impl<T: ?Sized> RefCell<T> {
     /// ```
     #[inline]
     #[stable(feature = "cell_as_ptr", since = "1.12.0")]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[rustc_never_returns_null_ptr]
     pub fn as_ptr(&self) -> *mut T {
         self.value.get()
@@ -2158,6 +2160,7 @@ impl<T: ?Sized> UnsafeCell<T> {
     #[inline(always)]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_unsafecell_get", since = "1.32.0")]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[rustc_never_returns_null_ptr]
     pub const fn get(&self) -> *mut T {
         // We can just cast the pointer from `UnsafeCell<T>` to `T` because of
@@ -2271,6 +2274,7 @@ impl<T: DispatchFromDyn<U>, U> DispatchFromDyn<UnsafeCell<U>> for UnsafeCell<T>
 /// See [`UnsafeCell`] for details.
 #[unstable(feature = "sync_unsafe_cell", issue = "95439")]
 #[repr(transparent)]
+#[rustc_diagnostic_item = "SyncUnsafeCell"]
 #[rustc_pub_transparent]
 pub struct SyncUnsafeCell<T: ?Sized> {
     value: UnsafeCell<T>,
@@ -2304,6 +2308,7 @@ impl<T: ?Sized> SyncUnsafeCell<T> {
     /// when casting to `&mut T`, and ensure that there are no mutations
     /// or mutable aliases going on when casting to `&T`
     #[inline]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[rustc_never_returns_null_ptr]
     pub const fn get(&self) -> *mut T {
         self.value.get()
diff --git a/library/core/src/ffi/c_str.rs b/library/core/src/ffi/c_str.rs
index 85571222b5c..9e32f74227c 100644
--- a/library/core/src/ffi/c_str.rs
+++ b/library/core/src/ffi/c_str.rs
@@ -500,6 +500,7 @@ impl CStr {
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_str_as_ptr", since = "1.32.0")]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[rustc_never_returns_null_ptr]
     pub const fn as_ptr(&self) -> *const c_char {
         self.inner.as_ptr()
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 3b8ac20e527..d30bf96cfd4 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -121,7 +121,6 @@
 #![feature(const_float_methods)]
 #![feature(const_heap)]
 #![feature(const_nonnull_new)]
-#![feature(const_pin_2)]
 #![feature(const_ptr_sub_ptr)]
 #![feature(const_raw_ptr_comparison)]
 #![feature(const_size_of_val)]
diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs
index 1c5c58d64a2..c8ea52a1fb0 100644
--- a/library/core/src/marker.rs
+++ b/library/core/src/marker.rs
@@ -981,6 +981,18 @@ pub trait Tuple {}
 )]
 pub trait PointerLike {}
 
+#[cfg(not(bootstrap))]
+marker_impls! {
+    #[unstable(feature = "pointer_like_trait", issue = "none")]
+    PointerLike for
+        usize,
+        {T} &T,
+        {T} &mut T,
+        {T} *const T,
+        {T} *mut T,
+        {T: PointerLike} crate::pin::Pin<T>,
+}
+
 /// A marker for types which can be used as types of `const` generic parameters.
 ///
 /// These types must have a proper equivalence relation (`Eq`) and it must be automatically
diff --git a/library/core/src/mem/maybe_uninit.rs b/library/core/src/mem/maybe_uninit.rs
index 8c6cdf57c58..58315cb74f0 100644
--- a/library/core/src/mem/maybe_uninit.rs
+++ b/library/core/src/mem/maybe_uninit.rs
@@ -525,6 +525,7 @@ impl<T> MaybeUninit<T> {
     /// until they are, it is advisable to avoid them.)
     #[stable(feature = "maybe_uninit", since = "1.36.0")]
     #[rustc_const_stable(feature = "const_maybe_uninit_as_ptr", since = "1.59.0")]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline(always)]
     pub const fn as_ptr(&self) -> *const T {
         // `MaybeUninit` and `ManuallyDrop` are both `repr(transparent)` so we can cast the pointer.
@@ -566,6 +567,7 @@ impl<T> MaybeUninit<T> {
     /// until they are, it is advisable to avoid them.)
     #[stable(feature = "maybe_uninit", since = "1.36.0")]
     #[rustc_const_stable(feature = "const_maybe_uninit_as_mut_ptr", since = "1.83.0")]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline(always)]
     pub const fn as_mut_ptr(&mut self) -> *mut T {
         // `MaybeUninit` and `ManuallyDrop` are both `repr(transparent)` so we can cast the pointer.
diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
index 254b306fcaa..c14c49a0d92 100644
--- a/library/core/src/pin.rs
+++ b/library/core/src/pin.rs
@@ -1214,7 +1214,8 @@ impl<Ptr: Deref<Target: Unpin>> Pin<Ptr> {
     /// assert_eq!(*r, 5);
     /// ```
     #[inline(always)]
-    #[rustc_const_unstable(feature = "const_pin_2", issue = "76654")]
+    #[rustc_allow_const_fn_unstable(const_precise_live_drops)]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     #[stable(feature = "pin_into_inner", since = "1.39.0")]
     pub const fn into_inner(pin: Pin<Ptr>) -> Ptr {
         pin.__pointer
@@ -1503,7 +1504,8 @@ impl<Ptr: Deref> Pin<Ptr> {
     /// If the underlying data is [`Unpin`], [`Pin::into_inner`] should be used
     /// instead.
     #[inline(always)]
-    #[rustc_const_unstable(feature = "const_pin_2", issue = "76654")]
+    #[rustc_allow_const_fn_unstable(const_precise_live_drops)]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     #[stable(feature = "pin_into_inner", since = "1.39.0")]
     pub const unsafe fn into_inner_unchecked(pin: Pin<Ptr>) -> Ptr {
         pin.__pointer
diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index ef52cc44126..c855f963771 100644
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -735,6 +735,7 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_slice_as_ptr", since = "1.32.0")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline(always)]
     #[must_use]
     pub const fn as_ptr(&self) -> *const T {
@@ -765,6 +766,7 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline(always)]
     #[must_use]
     pub const fn as_mut_ptr(&mut self) -> *mut T {
diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs
index 5aecbf303f9..4629b770cb4 100644
--- a/library/core/src/str/mod.rs
+++ b/library/core/src/str/mod.rs
@@ -373,6 +373,7 @@ impl str {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "rustc_str_as_ptr", since = "1.32.0")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[must_use]
     #[inline(always)]
     pub const fn as_ptr(&self) -> *const u8 {
@@ -390,6 +391,7 @@ impl str {
     #[stable(feature = "str_as_mut_ptr", since = "1.36.0")]
     #[rustc_const_stable(feature = "const_str_as_mut", since = "1.83.0")]
     #[rustc_never_returns_null_ptr]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[must_use]
     #[inline(always)]
     pub const fn as_mut_ptr(&mut self) -> *mut u8 {
diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
index f515e9e4109..f7825571cd7 100644
--- a/library/core/tests/lib.rs
+++ b/library/core/tests/lib.rs
@@ -21,7 +21,6 @@
 #![feature(const_eval_select)]
 #![feature(const_heap)]
 #![feature(const_nonnull_new)]
-#![feature(const_pin_2)]
 #![feature(const_trait_impl)]
 #![feature(core_intrinsics)]
 #![feature(core_io_borrowed_buf)]
diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index 76fdb1a4ffd..555e8804eab 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -2738,6 +2738,10 @@ pub fn create_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> {
 
 /// Removes an empty directory.
 ///
+/// If you want to remove a directory that is not empty, as well as all
+/// of its contents recursively, consider using [`remove_dir_all`]
+/// instead.
+///
 /// # Platform-specific behavior
 ///
 /// This function currently corresponds to the `rmdir` function on Unix
diff --git a/library/std/src/io/cursor.rs b/library/std/src/io/cursor.rs
index 9f913eae095..fbfdb4fa023 100644
--- a/library/std/src/io/cursor.rs
+++ b/library/std/src/io/cursor.rs
@@ -153,7 +153,8 @@ impl<T> Cursor<T> {
     /// let reference = buff.get_mut();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn get_mut(&mut self) -> &mut T {
+    #[rustc_const_unstable(feature = "const_mut_cursor", issue = "130801")]
+    pub const fn get_mut(&mut self) -> &mut T {
         &mut self.inner
     }
 
@@ -200,7 +201,8 @@ impl<T> Cursor<T> {
     /// assert_eq!(buff.position(), 4);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn set_position(&mut self, pos: u64) {
+    #[rustc_const_unstable(feature = "const_mut_cursor", issue = "130801")]
+    pub const fn set_position(&mut self, pos: u64) {
         self.pos = pos;
     }
 }
diff --git a/library/std/src/sys/pal/uefi/process.rs b/library/std/src/sys/pal/uefi/process.rs
index 0cc9cecb89d..1b83f4b0aee 100644
--- a/library/std/src/sys/pal/uefi/process.rs
+++ b/library/std/src/sys/pal/uefi/process.rs
@@ -18,6 +18,7 @@ use crate::{fmt, io};
 #[derive(Debug)]
 pub struct Command {
     prog: OsString,
+    args: Vec<OsString>,
     stdout: Option<Stdio>,
     stderr: Option<Stdio>,
 }
@@ -39,12 +40,11 @@ pub enum Stdio {
 
 impl Command {
     pub fn new(program: &OsStr) -> Command {
-        Command { prog: program.to_os_string(), stdout: None, stderr: None }
+        Command { prog: program.to_os_string(), args: Vec::new(), stdout: None, stderr: None }
     }
 
-    // FIXME: Implement arguments as reverse of parsing algorithm
-    pub fn arg(&mut self, _arg: &OsStr) {
-        panic!("unsupported")
+    pub fn arg(&mut self, arg: &OsStr) {
+        self.args.push(arg.to_os_string());
     }
 
     pub fn env_mut(&mut self) -> &mut CommandEnv {
@@ -72,7 +72,7 @@ impl Command {
     }
 
     pub fn get_args(&self) -> CommandArgs<'_> {
-        panic!("unsupported")
+        CommandArgs { iter: self.args.iter() }
     }
 
     pub fn get_envs(&self) -> CommandEnvs<'_> {
@@ -116,6 +116,12 @@ impl Command {
     pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
         let mut cmd = uefi_command_internal::Image::load_image(&self.prog)?;
 
+        // UEFI adds the bin name by default
+        if !self.args.is_empty() {
+            let args = uefi_command_internal::create_args(&self.prog, &self.args);
+            cmd.set_args(args);
+        }
+
         // Setup Stdout
         let stdout = self.stdout.unwrap_or(Stdio::MakePipe);
         let stdout = Self::create_pipe(stdout)?;
@@ -315,7 +321,7 @@ mod uefi_command_internal {
         stdout: Option<helpers::OwnedProtocol<PipeProtocol>>,
         stderr: Option<helpers::OwnedProtocol<PipeProtocol>>,
         st: OwnedTable<r_efi::efi::SystemTable>,
-        args: Option<Vec<u16>>,
+        args: Option<(*mut u16, usize)>,
     }
 
     impl Image {
@@ -449,20 +455,20 @@ mod uefi_command_internal {
             }
         }
 
-        pub fn set_args(&mut self, args: &OsStr) {
+        pub fn set_args(&mut self, args: Box<[u16]>) {
             let loaded_image: NonNull<loaded_image::Protocol> =
                 helpers::open_protocol(self.handle, loaded_image::PROTOCOL_GUID).unwrap();
 
-            let mut args = args.encode_wide().collect::<Vec<u16>>();
-            let args_size = (crate::mem::size_of::<u16>() * args.len()) as u32;
+            let len = args.len();
+            let args_size: u32 = crate::mem::size_of_val(&args).try_into().unwrap();
+            let ptr = Box::into_raw(args).as_mut_ptr();
 
             unsafe {
-                (*loaded_image.as_ptr()).load_options =
-                    args.as_mut_ptr() as *mut crate::ffi::c_void;
+                (*loaded_image.as_ptr()).load_options = ptr as *mut crate::ffi::c_void;
                 (*loaded_image.as_ptr()).load_options_size = args_size;
             }
 
-            self.args = Some(args);
+            self.args = Some((ptr, len));
         }
 
         fn update_st_crc32(&mut self) -> io::Result<()> {
@@ -502,6 +508,10 @@ mod uefi_command_internal {
                     ((*bt.as_ptr()).unload_image)(self.handle.as_ptr());
                 }
             }
+
+            if let Some((ptr, len)) = self.args {
+                let _ = unsafe { Box::from_raw(crate::ptr::slice_from_raw_parts_mut(ptr, len)) };
+            }
         }
     }
 
@@ -681,4 +691,38 @@ mod uefi_command_internal {
             }
         }
     }
+
+    pub fn create_args(prog: &OsStr, args: &[OsString]) -> Box<[u16]> {
+        const QUOTE: u16 = 0x0022;
+        const SPACE: u16 = 0x0020;
+        const CARET: u16 = 0x005e;
+        const NULL: u16 = 0;
+
+        // This is the lower bound on the final length under the assumption that
+        // the arguments only contain ASCII characters.
+        let mut res = Vec::with_capacity(args.iter().map(|arg| arg.len() + 3).sum());
+
+        // Wrap program name in quotes to avoid any problems
+        res.push(QUOTE);
+        res.extend(prog.encode_wide());
+        res.push(QUOTE);
+        res.push(SPACE);
+
+        for arg in args {
+            // Wrap the argument in quotes to be treat as single arg
+            res.push(QUOTE);
+            for c in arg.encode_wide() {
+                // CARET in quotes is used to escape CARET or QUOTE
+                if c == QUOTE || c == CARET {
+                    res.push(CARET);
+                }
+                res.push(c);
+            }
+            res.push(QUOTE);
+
+            res.push(SPACE);
+        }
+
+        res.into_boxed_slice()
+    }
 }
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 227ee9d64f3..2c2cc58a9dd 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -188,6 +188,11 @@ mod current;
 pub use current::current;
 pub(crate) use current::{current_id, drop_current, set_current, try_current};
 
+mod spawnhook;
+
+#[unstable(feature = "thread_spawn_hook", issue = "132951")]
+pub use spawnhook::add_spawn_hook;
+
 ////////////////////////////////////////////////////////////////////////////////
 // Thread-local storage
 ////////////////////////////////////////////////////////////////////////////////
@@ -259,6 +264,8 @@ pub struct Builder {
     name: Option<String>,
     // The size of the stack for the spawned thread in bytes
     stack_size: Option<usize>,
+    // Skip running and inheriting the thread spawn hooks
+    no_hooks: bool,
 }
 
 impl Builder {
@@ -282,7 +289,7 @@ impl Builder {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn new() -> Builder {
-        Builder { name: None, stack_size: None }
+        Builder { name: None, stack_size: None, no_hooks: false }
     }
 
     /// Names the thread-to-be. Currently the name is used for identification
@@ -338,6 +345,16 @@ impl Builder {
         self
     }
 
+    /// Disables running and inheriting [spawn hooks](add_spawn_hook).
+    ///
+    /// Use this if the parent thread is in no way relevant for the child thread.
+    /// For example, when lazily spawning threads for a thread pool.
+    #[unstable(feature = "thread_spawn_hook", issue = "132951")]
+    pub fn no_hooks(mut self) -> Builder {
+        self.no_hooks = true;
+        self
+    }
+
     /// Spawns a new thread by taking ownership of the `Builder`, and returns an
     /// [`io::Result`] to its [`JoinHandle`].
     ///
@@ -460,7 +477,7 @@ impl Builder {
         F: Send,
         T: Send,
     {
-        let Builder { name, stack_size } = self;
+        let Builder { name, stack_size, no_hooks } = self;
 
         let stack_size = stack_size.unwrap_or_else(|| {
             static MIN: AtomicUsize = AtomicUsize::new(0);
@@ -485,6 +502,13 @@ impl Builder {
             Some(name) => Thread::new(id, name.into()),
             None => Thread::new_unnamed(id),
         };
+
+        let hooks = if no_hooks {
+            spawnhook::ChildSpawnHooks::default()
+        } else {
+            spawnhook::run_spawn_hooks(&my_thread)
+        };
+
         let their_thread = my_thread.clone();
 
         let my_packet: Arc<Packet<'scope, T>> = Arc::new(Packet {
@@ -494,9 +518,6 @@ impl Builder {
         });
         let their_packet = my_packet.clone();
 
-        let output_capture = crate::io::set_output_capture(None);
-        crate::io::set_output_capture(output_capture.clone());
-
         // Pass `f` in `MaybeUninit` because actually that closure might *run longer than the lifetime of `F`*.
         // See <https://github.com/rust-lang/rust/issues/101983> for more details.
         // To prevent leaks we use a wrapper that drops its contents.
@@ -534,10 +555,9 @@ impl Builder {
                 imp::Thread::set_name(name);
             }
 
-            crate::io::set_output_capture(output_capture);
-
             let f = f.into_inner();
             let try_result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+                crate::sys::backtrace::__rust_begin_short_backtrace(|| hooks.run());
                 crate::sys::backtrace::__rust_begin_short_backtrace(f)
             }));
             // SAFETY: `their_packet` as been built just above and moved by the
diff --git a/library/std/src/thread/spawnhook.rs b/library/std/src/thread/spawnhook.rs
new file mode 100644
index 00000000000..99b5ad9cb9f
--- /dev/null
+++ b/library/std/src/thread/spawnhook.rs
@@ -0,0 +1,148 @@
+use crate::cell::Cell;
+use crate::iter;
+use crate::sync::Arc;
+use crate::thread::Thread;
+
+crate::thread_local! {
+    /// A thread local linked list of spawn hooks.
+    ///
+    /// It is a linked list of Arcs, such that it can very cheaply be inhereted by spawned threads.
+    ///
+    /// (That technically makes it a set of linked lists with shared tails, so a linked tree.)
+    static SPAWN_HOOKS: Cell<SpawnHooks> = const { Cell::new(SpawnHooks { first: None }) };
+}
+
+#[derive(Default, Clone)]
+struct SpawnHooks {
+    first: Option<Arc<SpawnHook>>,
+}
+
+// Manually implement drop to prevent deep recursion when dropping linked Arc list.
+impl Drop for SpawnHooks {
+    fn drop(&mut self) {
+        let mut next = self.first.take();
+        while let Some(SpawnHook { hook, next: n }) = next.and_then(|n| Arc::into_inner(n)) {
+            drop(hook);
+            next = n;
+        }
+    }
+}
+
+struct SpawnHook {
+    hook: Box<dyn Send + Sync + Fn(&Thread) -> Box<dyn Send + FnOnce()>>,
+    next: Option<Arc<SpawnHook>>,
+}
+
+/// Registers a function to run for every newly thread spawned.
+///
+/// The hook is executed in the parent thread, and returns a function
+/// that will be executed in the new thread.
+///
+/// The hook is called with the `Thread` handle for the new thread.
+///
+/// The hook will only be added for the current thread and is inherited by the threads it spawns.
+/// In other words, adding a hook has no effect on already running threads (other than the current
+/// thread) and the threads they might spawn in the future.
+///
+/// Hooks can only be added, not removed.
+///
+/// The hooks will run in reverse order, starting with the most recently added.
+///
+/// # Usage
+///
+/// ```
+/// #![feature(thread_spawn_hook)]
+///
+/// std::thread::add_spawn_hook(|_| {
+///     ..; // This will run in the parent (spawning) thread.
+///     move || {
+///         ..; // This will run it the child (spawned) thread.
+///     }
+/// });
+/// ```
+///
+/// # Example
+///
+/// A spawn hook can be used to "inherit" a thread local from the parent thread:
+///
+/// ```
+/// #![feature(thread_spawn_hook)]
+///
+/// use std::cell::Cell;
+///
+/// thread_local! {
+///     static X: Cell<u32> = Cell::new(0);
+/// }
+///
+/// // This needs to be done once in the main thread before spawning any threads.
+/// std::thread::add_spawn_hook(|_| {
+///     // Get the value of X in the spawning thread.
+///     let value = X.get();
+///     // Set the value of X in the newly spawned thread.
+///     move || X.set(value)
+/// });
+///
+/// X.set(123);
+///
+/// std::thread::spawn(|| {
+///     assert_eq!(X.get(), 123);
+/// }).join().unwrap();
+/// ```
+#[unstable(feature = "thread_spawn_hook", issue = "132951")]
+pub fn add_spawn_hook<F, G>(hook: F)
+where
+    F: 'static + Send + Sync + Fn(&Thread) -> G,
+    G: 'static + Send + FnOnce(),
+{
+    SPAWN_HOOKS.with(|h| {
+        let mut hooks = h.take();
+        let next = hooks.first.take();
+        hooks.first = Some(Arc::new(SpawnHook {
+            hook: Box::new(move |thread| Box::new(hook(thread))),
+            next,
+        }));
+        h.set(hooks);
+    });
+}
+
+/// Runs all the spawn hooks.
+///
+/// Called on the parent thread.
+///
+/// Returns the functions to be called on the newly spawned thread.
+pub(super) fn run_spawn_hooks(thread: &Thread) -> ChildSpawnHooks {
+    // Get a snapshot of the spawn hooks.
+    // (Increments the refcount to the first node.)
+    let hooks = SPAWN_HOOKS.with(|hooks| {
+        let snapshot = hooks.take();
+        hooks.set(snapshot.clone());
+        snapshot
+    });
+    // Iterate over the hooks, run them, and collect the results in a vector.
+    let to_run: Vec<_> = iter::successors(hooks.first.as_deref(), |hook| hook.next.as_deref())
+        .map(|hook| (hook.hook)(thread))
+        .collect();
+    // Pass on the snapshot of the hooks and the results to the new thread,
+    // which will then run SpawnHookResults::run().
+    ChildSpawnHooks { hooks, to_run }
+}
+
+/// The results of running the spawn hooks.
+///
+/// This struct is sent to the new thread.
+/// It contains the inherited hooks and the closures to be run.
+#[derive(Default)]
+pub(super) struct ChildSpawnHooks {
+    hooks: SpawnHooks,
+    to_run: Vec<Box<dyn FnOnce() + Send>>,
+}
+
+impl ChildSpawnHooks {
+    // This is run on the newly spawned thread, directly at the start.
+    pub(super) fn run(self) {
+        SPAWN_HOOKS.set(self.hooks);
+        for run in self.to_run {
+            run();
+        }
+    }
+}
diff --git a/library/test/src/lib.rs b/library/test/src/lib.rs
index 30ccfe2af8d..47407df909b 100644
--- a/library/test/src/lib.rs
+++ b/library/test/src/lib.rs
@@ -24,6 +24,7 @@
 #![feature(process_exitcode_internals)]
 #![feature(panic_can_unwind)]
 #![feature(test)]
+#![feature(thread_spawn_hook)]
 #![allow(internal_features)]
 #![warn(rustdoc::unescaped_backticks)]
 
@@ -134,6 +135,16 @@ pub fn test_main(args: &[String], tests: Vec<TestDescAndFn>, options: Option<Opt
                 }
             });
             panic::set_hook(hook);
+            // Use a thread spawning hook to make new threads inherit output capturing.
+            std::thread::add_spawn_hook(|_| {
+                // Get and clone the output capture of the current thread.
+                let output_capture = io::set_output_capture(None);
+                io::set_output_capture(output_capture.clone());
+                // Set the output capture of the new thread.
+                || {
+                    io::set_output_capture(output_capture);
+                }
+            });
         }
         let res = console::run_tests_console(&opts, tests);
         // Prevent Valgrind from reporting reachable blocks in users' unit tests.
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 95b1303fa71..e706aba977b 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -1255,6 +1255,10 @@ impl Config {
             },
             out: PathBuf::from("build"),
 
+            // This is needed by codegen_ssa on macOS to ship `llvm-objcopy` aliased to
+            // `rust-objcopy` to workaround bad `strip`s on macOS.
+            llvm_tools_enabled: true,
+
             ..Default::default()
         }
     }
diff --git a/src/bootstrap/src/utils/change_tracker.rs b/src/bootstrap/src/utils/change_tracker.rs
index 1d05f94e3be..7f62ffb20db 100644
--- a/src/bootstrap/src/utils/change_tracker.rs
+++ b/src/bootstrap/src/utils/change_tracker.rs
@@ -300,4 +300,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Info,
         summary: "`download-rustc='if-unchanged'` is now a default option for library profile.",
     },
+    ChangeInfo {
+        change_id: 133207,
+        severity: ChangeSeverity::Info,
+        summary: "`rust.llvm-tools` is now enabled by default when no `config.toml` is provided.",
+    },
 ];
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 340dfd67b7d..9a51a3f4268 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -465,7 +465,7 @@ auto:
       SCRIPT: python x.py dist bootstrap --include-default-paths
       DIST_REQUIRE_ALL_TOOLS: 1
       CODEGEN_BACKENDS: llvm,cranelift
-    <<: *job-windows-8c
+    <<: *job-windows
 
   - image: dist-aarch64-msvc
     env:
@@ -477,7 +477,7 @@ auto:
         --enable-profiler
       SCRIPT: python x.py dist bootstrap --include-default-paths
       DIST_REQUIRE_ALL_TOOLS: 1
-    <<: *job-windows-8c
+    <<: *job-windows
 
   - image: dist-i686-mingw
     env:
diff --git a/src/doc/rustc/src/platform-support/wasm32-wasip2.md b/src/doc/rustc/src/platform-support/wasm32-wasip2.md
index bb2348b201e..40049ecfa5f 100644
--- a/src/doc/rustc/src/platform-support/wasm32-wasip2.md
+++ b/src/doc/rustc/src/platform-support/wasm32-wasip2.md
@@ -1,6 +1,6 @@
 # `wasm32-wasip2`
 
-**Tier: 3**
+**Tier: 2**
 
 The `wasm32-wasip2` target is a new and still (as of January 2024) an
 experimental target. This target is an extension to `wasm32-wasip1` target,
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index 31e4e79c00a..3fe567b1c39 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -21,7 +21,7 @@ pub(crate) fn synthesize_auto_trait_impls<'tcx>(
     item_def_id: DefId,
 ) -> Vec<clean::Item> {
     let tcx = cx.tcx;
-    let param_env = tcx.param_env(item_def_id);
+    let typing_env = ty::TypingEnv::non_body_analysis(tcx, item_def_id);
     let ty = tcx.type_of(item_def_id).instantiate_identity();
 
     let finder = auto_trait::AutoTraitFinder::new(tcx);
@@ -34,7 +34,7 @@ pub(crate) fn synthesize_auto_trait_impls<'tcx>(
                 cx,
                 ty,
                 trait_def_id,
-                param_env,
+                typing_env,
                 item_def_id,
                 &finder,
                 DiscardPositiveImpls::No,
@@ -42,13 +42,13 @@ pub(crate) fn synthesize_auto_trait_impls<'tcx>(
         })
         .collect();
     // We are only interested in case the type *doesn't* implement the `Sized` trait.
-    if !ty.is_sized(tcx, param_env)
+    if !ty.is_sized(tcx, typing_env)
         && let Some(sized_trait_def_id) = tcx.lang_items().sized_trait()
         && let Some(impl_item) = synthesize_auto_trait_impl(
             cx,
             ty,
             sized_trait_def_id,
-            param_env,
+            typing_env,
             item_def_id,
             &finder,
             DiscardPositiveImpls::Yes,
@@ -64,7 +64,7 @@ fn synthesize_auto_trait_impl<'tcx>(
     cx: &mut DocContext<'tcx>,
     ty: Ty<'tcx>,
     trait_def_id: DefId,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     item_def_id: DefId,
     finder: &auto_trait::AutoTraitFinder<'tcx>,
     discard_positive_impls: DiscardPositiveImpls,
@@ -76,7 +76,7 @@ fn synthesize_auto_trait_impl<'tcx>(
         return None;
     }
 
-    let result = finder.find_auto_trait_generics(ty, param_env, trait_def_id, |info| {
+    let result = finder.find_auto_trait_generics(ty, typing_env, trait_def_id, |info| {
         clean_param_env(cx, item_def_id, info.full_user_env, info.region_data, info.vid_to_region)
     });
 
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index e42350dc5e6..031696d445d 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1818,9 +1818,7 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
                     let ct = if let hir::ConstArgKind::Anon(hir::AnonConst { def_id, .. }) =
                         const_arg.kind
                     {
-                        // Only anon consts can implicitly capture params.
-                        // FIXME: is this correct behavior?
-                        let typing_env = ty::TypingEnv::from_param_env(cx.tcx.param_env(*def_id));
+                        let typing_env = ty::TypingEnv::post_analysis(cx.tcx, *def_id);
                         cx.tcx.normalize_erasing_regions(typing_env, ct)
                     } else {
                         ct
diff --git a/src/librustdoc/html/highlight.rs b/src/librustdoc/html/highlight.rs
index 4def80764ea..29f6f92a6b2 100644
--- a/src/librustdoc/html/highlight.rs
+++ b/src/librustdoc/html/highlight.rs
@@ -861,10 +861,9 @@ impl<'src> Classifier<'src> {
                 },
                 Some(c) => c,
             },
-            TokenKind::RawIdent
-            | TokenKind::UnknownPrefix
-            | TokenKind::InvalidPrefix
-            | TokenKind::InvalidIdent => Class::Ident(self.new_span(before, text)),
+            TokenKind::RawIdent | TokenKind::UnknownPrefix | TokenKind::InvalidIdent => {
+                Class::Ident(self.new_span(before, text))
+            }
             TokenKind::Lifetime { .. }
             | TokenKind::RawLifetime
             | TokenKind::UnknownPrefixLifetime => Class::Lifetime,
diff --git a/src/tools/clippy/clippy_lints/src/casts/ptr_as_ptr.rs b/src/tools/clippy/clippy_lints/src/casts/ptr_as_ptr.rs
index 86c5f6b9f0b..46d67e615c7 100644
--- a/src/tools/clippy/clippy_lints/src/casts/ptr_as_ptr.rs
+++ b/src/tools/clippy/clippy_lints/src/casts/ptr_as_ptr.rs
@@ -39,7 +39,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: &Msrv) {
             (Mutability::Not, Mutability::Not) | (Mutability::Mut, Mutability::Mut))
         // The `U` in `pointer::cast` have to be `Sized`
         // as explained here: https://github.com/rust-lang/rust/issues/60602.
-        && to_pointee_ty.is_sized(cx.tcx, cx.param_env)
+        && to_pointee_ty.is_sized(cx.tcx, cx.typing_env())
     {
         let mut app = Applicability::MachineApplicable;
         let turbofish = match &cast_to_hir_ty.kind {
diff --git a/src/tools/clippy/clippy_lints/src/dereference.rs b/src/tools/clippy/clippy_lints/src/dereference.rs
index f864b7a5a8a..fce7f9985ea 100644
--- a/src/tools/clippy/clippy_lints/src/dereference.rs
+++ b/src/tools/clippy/clippy_lints/src/dereference.rs
@@ -15,6 +15,7 @@ use rustc_hir::{
     self as hir, BindingMode, Body, BodyId, BorrowKind, Expr, ExprKind, HirId, MatchSource, Mutability, Node, Pat,
     PatKind, Path, QPath, TyKind, UnOp,
 };
+use rustc_hir::def_id::DefId;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, TypeckResults};
@@ -753,11 +754,10 @@ impl TyCoercionStability {
     fn for_defined_ty<'tcx>(cx: &LateContext<'tcx>, ty: DefinedTy<'tcx>, for_return: bool) -> Self {
         match ty {
             DefinedTy::Hir(ty) => Self::for_hir_ty(ty),
-            DefinedTy::Mir(ty) => Self::for_mir_ty(
+            DefinedTy::Mir { def_site_def_id, ty } => Self::for_mir_ty(
                 cx.tcx,
-                // FIXME(#132279): convert `DefinedTy` to use `TypingEnv` instead.
-                ty::TypingEnv::from_param_env(ty.param_env),
-                cx.tcx.instantiate_bound_regions_with_erased(ty.value),
+                def_site_def_id,
+                cx.tcx.instantiate_bound_regions_with_erased(ty),
                 for_return,
             ),
         }
@@ -824,12 +824,15 @@ impl TyCoercionStability {
         }
     }
 
-    fn for_mir_ty<'tcx>(tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>, ty: Ty<'tcx>, for_return: bool) -> Self {
+    fn for_mir_ty<'tcx>(tcx: TyCtxt<'tcx>, def_site_def_id: Option<DefId>, ty: Ty<'tcx>, for_return: bool) -> Self {
         let ty::Ref(_, mut ty, _) = *ty.kind() else {
             return Self::None;
         };
 
-        ty = tcx.try_normalize_erasing_regions(typing_env, ty).unwrap_or(ty);
+        if let Some(def_id) = def_site_def_id {
+            let typing_env = ty::TypingEnv::non_body_analysis(tcx, def_id);
+            ty = tcx.try_normalize_erasing_regions(typing_env, ty).unwrap_or(ty);
+        }
         loop {
             break match *ty.kind() {
                 ty::Ref(_, ref_ty, _) => {
@@ -1028,7 +1031,7 @@ fn report<'tcx>(
         State::ExplicitDeref { mutability } => {
             if is_block_like(expr)
                 && let ty::Ref(_, ty, _) = data.adjusted_ty.kind()
-                && ty.is_sized(cx.tcx, cx.param_env)
+                && ty.is_sized(cx.tcx, cx.typing_env())
             {
                 // Rustc bug: auto deref doesn't work on block expression when targeting sized types.
                 return;
diff --git a/src/tools/clippy/clippy_lints/src/derive.rs b/src/tools/clippy/clippy_lints/src/derive.rs
index 0db6a822ec0..3b6b3c89858 100644
--- a/src/tools/clippy/clippy_lints/src/derive.rs
+++ b/src/tools/clippy/clippy_lints/src/derive.rs
@@ -454,13 +454,13 @@ fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_r
         && cx.tcx.is_diagnostic_item(sym::PartialEq, def_id)
         && !has_non_exhaustive_attr(cx.tcx, *adt)
         && !ty_implements_eq_trait(cx.tcx, ty, eq_trait_def_id)
-        && let param_env = param_env_for_derived_eq(cx.tcx, adt.did(), eq_trait_def_id)
+        && let typing_env = typing_env_env_for_derived_eq(cx.tcx, adt.did(), eq_trait_def_id)
         && let Some(local_def_id) = adt.did().as_local()
         // If all of our fields implement `Eq`, we can implement `Eq` too
         && adt
             .all_fields()
             .map(|f| f.ty(cx.tcx, args))
-            .all(|ty| implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, None, &[]))
+            .all(|ty| implements_trait_with_env(cx.tcx, typing_env, ty, eq_trait_def_id, None, &[]))
     {
         span_lint_hir_and_then(
             cx,
@@ -485,7 +485,7 @@ fn ty_implements_eq_trait<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, eq_trait_id: De
 }
 
 /// Creates the `ParamEnv` used for the give type's derived `Eq` impl.
-fn param_env_for_derived_eq(tcx: TyCtxt<'_>, did: DefId, eq_trait_id: DefId) -> ParamEnv<'_> {
+fn typing_env_env_for_derived_eq(tcx: TyCtxt<'_>, did: DefId, eq_trait_id: DefId) -> ty::TypingEnv<'_> {
     // Initial map from generic index to param def.
     // Vec<(param_def, needs_eq)>
     let mut params = tcx
@@ -506,7 +506,7 @@ fn param_env_for_derived_eq(tcx: TyCtxt<'_>, did: DefId, eq_trait_id: DefId) ->
         }
     }
 
-    ParamEnv::new(
+    let param_env = ParamEnv::new(
         tcx.mk_clauses_from_iter(ty_predicates.iter().map(|&(p, _)| p).chain(
             params.iter().filter(|&&(_, needs_eq)| needs_eq).map(|&(param, _)| {
                 ClauseKind::Trait(TraitPredicate {
@@ -517,5 +517,9 @@ fn param_env_for_derived_eq(tcx: TyCtxt<'_>, did: DefId, eq_trait_id: DefId) ->
             }),
         )),
         Reveal::UserFacing,
-    )
+    );
+    ty::TypingEnv {
+        typing_mode: ty::TypingMode::non_body_analysis(),
+        param_env,
+    }
 }
diff --git a/src/tools/clippy/clippy_lints/src/functions/must_use.rs b/src/tools/clippy/clippy_lints/src/functions/must_use.rs
index c74ba088b78..175d92d2d79 100644
--- a/src/tools/clippy/clippy_lints/src/functions/must_use.rs
+++ b/src/tools/clippy/clippy_lints/src/functions/must_use.rs
@@ -198,7 +198,7 @@ fn is_mutable_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, tys: &mut DefIdSet)
         // primitive types are never mutable
         ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str => false,
         ty::Adt(adt, args) => {
-            tys.insert(adt.did()) && !ty.is_freeze(cx.tcx, cx.param_env)
+            tys.insert(adt.did()) && !ty.is_freeze(cx.tcx, cx.typing_env())
                 || matches!(cx.tcx.get_diagnostic_name(adt.did()), Some(sym::Rc | sym::Arc))
                     && args.types().any(|ty| is_mutable_ty(cx, ty, tys))
         },
diff --git a/src/tools/clippy/clippy_lints/src/let_if_seq.rs b/src/tools/clippy/clippy_lints/src/let_if_seq.rs
index 0e488cee6b7..5db28e9ae9b 100644
--- a/src/tools/clippy/clippy_lints/src/let_if_seq.rs
+++ b/src/tools/clippy/clippy_lints/src/let_if_seq.rs
@@ -80,7 +80,7 @@ impl<'tcx> LateLintPass<'tcx> for LetIfSeq {
                 let has_interior_mutability = !cx
                     .typeck_results()
                     .node_type(canonical_id)
-                    .is_freeze(cx.tcx, cx.param_env);
+                    .is_freeze(cx.tcx, cx.typing_env());
                 if has_interior_mutability {
                     return;
                 }
diff --git a/src/tools/clippy/clippy_lints/src/loops/explicit_iter_loop.rs b/src/tools/clippy/clippy_lints/src/loops/explicit_iter_loop.rs
index 48318682f33..d999e1a0585 100644
--- a/src/tools/clippy/clippy_lints/src/loops/explicit_iter_loop.rs
+++ b/src/tools/clippy/clippy_lints/src/loops/explicit_iter_loop.rs
@@ -115,11 +115,11 @@ fn is_ref_iterable<'tcx>(
             .tcx
             .liberate_late_bound_regions(fn_id, cx.tcx.fn_sig(fn_id).skip_binder())
         && let &[req_self_ty, req_res_ty] = &**sig.inputs_and_output
-        && let param_env = cx.tcx.param_env(fn_id)
-        && implements_trait_with_env(cx.tcx, param_env, req_self_ty, trait_id, Some(fn_id), &[])
+        && let typing_env = ty::TypingEnv::non_body_analysis(cx.tcx, fn_id)
+        && implements_trait_with_env(cx.tcx, typing_env, req_self_ty, trait_id, Some(fn_id), &[])
         && let Some(into_iter_ty) =
-            make_normalized_projection_with_regions(cx.tcx, param_env, trait_id, sym!(IntoIter), [req_self_ty])
-        && let req_res_ty = normalize_with_regions(cx.tcx, param_env, req_res_ty)
+            make_normalized_projection_with_regions(cx.tcx, typing_env, trait_id, sym!(IntoIter), [req_self_ty])
+        && let req_res_ty = normalize_with_regions(cx.tcx, typing_env, req_res_ty)
         && into_iter_ty == req_res_ty
     {
         let adjustments = typeck.expr_adjustments(self_arg);
diff --git a/src/tools/clippy/clippy_lints/src/methods/manual_inspect.rs b/src/tools/clippy/clippy_lints/src/methods/manual_inspect.rs
index 223b0630bfd..7aa13d8d5b6 100644
--- a/src/tools/clippy/clippy_lints/src/methods/manual_inspect.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/manual_inspect.rs
@@ -148,7 +148,7 @@ pub(crate) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, arg: &Expr<'_>, name:
                                 _ => {},
                             }
                         }
-                        requires_copy |= !ty.is_copy_modulo_regions(cx.tcx, cx.param_env);
+                        requires_copy |= !ty.is_copy_modulo_regions(cx.tcx, cx.typing_env());
                         break;
                     }
                 },
@@ -158,9 +158,9 @@ pub(crate) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, arg: &Expr<'_>, name:
         }
 
         if can_lint
-            && (!requires_copy || arg_ty.is_copy_modulo_regions(cx.tcx, cx.param_env))
+            && (!requires_copy || arg_ty.is_copy_modulo_regions(cx.tcx, cx.typing_env()))
             // This case could be handled, but a fair bit of care would need to be taken.
-            && (!requires_deref || arg_ty.is_freeze(cx.tcx, cx.param_env))
+            && (!requires_deref || arg_ty.is_freeze(cx.tcx, cx.typing_env()))
         {
             if requires_deref {
                 edits.push((param.span.shrink_to_lo(), "&".into()));
diff --git a/src/tools/clippy/clippy_lints/src/mut_mut.rs b/src/tools/clippy/clippy_lints/src/mut_mut.rs
index 6cddd7ea813..e2ab5e98504 100644
--- a/src/tools/clippy/clippy_lints/src/mut_mut.rs
+++ b/src/tools/clippy/clippy_lints/src/mut_mut.rs
@@ -80,7 +80,7 @@ impl<'tcx> intravisit::Visitor<'tcx> for MutVisitor<'_, 'tcx> {
                     "generally you want to avoid `&mut &mut _` if possible",
                 );
             } else if let ty::Ref(_, ty, hir::Mutability::Mut) = self.cx.typeck_results().expr_ty(e).kind() {
-                if ty.peel_refs().is_sized(self.cx.tcx, self.cx.param_env) {
+                if ty.peel_refs().is_sized(self.cx.tcx, self.cx.typing_env()) {
                     span_lint_hir(
                         self.cx,
                         MUT_MUT,
diff --git a/src/tools/clippy/clippy_lints/src/needless_borrows_for_generic_args.rs b/src/tools/clippy/clippy_lints/src/needless_borrows_for_generic_args.rs
index 43b885fbd2c..9ebef531bc5 100644
--- a/src/tools/clippy/clippy_lints/src/needless_borrows_for_generic_args.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_borrows_for_generic_args.rs
@@ -85,8 +85,8 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowsForGenericArgs<'tcx> {
             && use_cx.same_ctxt
             && !use_cx.is_ty_unified
             && let use_node = use_cx.use_node(cx)
-            && let Some(DefinedTy::Mir(ty)) = use_node.defined_ty(cx)
-            && let ty::Param(ty) = *ty.value.skip_binder().kind()
+            && let Some(DefinedTy::Mir { def_site_def_id: _, ty }) = use_node.defined_ty(cx)
+            && let ty::Param(param_ty) = *ty.skip_binder().kind()
             && let Some((hir_id, fn_id, i)) = match use_node {
                 ExprUseNode::MethodArg(_, _, 0) => None,
                 ExprUseNode::MethodArg(hir_id, None, i) => cx
@@ -112,7 +112,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowsForGenericArgs<'tcx> {
                 fn_id,
                 cx.typeck_results().node_args(hir_id),
                 i,
-                ty,
+                param_ty,
                 expr,
                 &self.msrv,
             )
diff --git a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
index 0775d7abdbb..b65ec8c3c48 100644
--- a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
@@ -180,11 +180,16 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
             if !is_self(arg)
                 && !ty.is_mutable_ptr()
                 && !is_copy(cx, ty)
-                && ty.is_sized(cx.tcx, cx.param_env)
+                && ty.is_sized(cx.tcx, cx.typing_env())
                 && !allowed_traits.iter().any(|&t| {
-                    implements_trait_with_env_from_iter(cx.tcx, cx.param_env, ty, t, None, [Option::<
-                        ty::GenericArg<'tcx>,
-                    >::None])
+                    implements_trait_with_env_from_iter(
+                        cx.tcx,
+                        cx.typing_env(),
+                        ty, 
+                        t,
+                        None,
+                        [None::<ty::GenericArg<'tcx>>]
+                    )
                 })
                 && !implements_borrow_trait
                 && !all_borrowable_trait
diff --git a/src/tools/clippy/clippy_lints/src/non_copy_const.rs b/src/tools/clippy/clippy_lints/src/non_copy_const.rs
index 57fa4797c5e..5416e00fe0c 100644
--- a/src/tools/clippy/clippy_lints/src/non_copy_const.rs
+++ b/src/tools/clippy/clippy_lints/src/non_copy_const.rs
@@ -270,8 +270,8 @@ impl<'tcx> NonCopyConst<'tcx> {
             instance,
             promoted: None,
         };
-        let param_env = cx.tcx.param_env(def_id).with_reveal_all_normalized(cx.tcx);
-        let result = cx.tcx.const_eval_global_id_for_typeck(param_env, cid, DUMMY_SP);
+        let typing_env = ty::TypingEnv::post_analysis(cx.tcx, def_id);
+        let result = cx.tcx.const_eval_global_id_for_typeck(typing_env, cid, DUMMY_SP);
         Self::is_value_unfrozen_raw(cx, result, ty)
     }
 
@@ -294,7 +294,7 @@ impl<'tcx> NonCopyConst<'tcx> {
                     instance,
                     promoted: None,
                 };
-                tcx.const_eval_global_id_for_typeck(typing_env.param_env, cid, span)
+                tcx.const_eval_global_id_for_typeck(typing_env, cid, span)
             },
             Ok(None) => Err(ErrorHandled::TooGeneric(span)),
             Err(err) => Err(ErrorHandled::Reported(err.into(), span)),
diff --git a/src/tools/clippy/clippy_lints/src/question_mark.rs b/src/tools/clippy/clippy_lints/src/question_mark.rs
index a00fd01a62e..f69cb9be4ca 100644
--- a/src/tools/clippy/clippy_lints/src/question_mark.rs
+++ b/src/tools/clippy/clippy_lints/src/question_mark.rs
@@ -251,7 +251,7 @@ fn check_is_none_or_err_and_early_return<'tcx>(cx: &LateContext<'tcx>, expr: &Ex
     {
         let mut applicability = Applicability::MachineApplicable;
         let receiver_str = snippet_with_applicability(cx, caller.span, "..", &mut applicability);
-        let by_ref = !caller_ty.is_copy_modulo_regions(cx.tcx, cx.param_env)
+        let by_ref = !caller_ty.is_copy_modulo_regions(cx.tcx, cx.typing_env())
             && !matches!(caller.kind, ExprKind::Call(..) | ExprKind::MethodCall(..));
         let sugg = if let Some(else_inner) = r#else {
             if eq_expr_value(cx, caller, peel_blocks(else_inner)) {
diff --git a/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ptr.rs b/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ptr.rs
index 0772b284968..bf6700b1b6b 100644
--- a/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ptr.rs
+++ b/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ptr.rs
@@ -27,7 +27,7 @@ pub(super) fn check<'tcx>(
                 |diag| {
                     if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
                         if from_mutbl == to_mutbl
-                            && to_pointee_ty.is_sized(cx.tcx, cx.param_env)
+                            && to_pointee_ty.is_sized(cx.tcx, cx.typing_env())
                             && msrv.meets(msrvs::POINTER_CAST)
                         {
                             diag.span_suggestion_verbose(
diff --git a/src/tools/clippy/clippy_lints/src/transmute/transmute_undefined_repr.rs b/src/tools/clippy/clippy_lints/src/transmute/transmute_undefined_repr.rs
index 4dc1290e8b1..48d65eb15d9 100644
--- a/src/tools/clippy/clippy_lints/src/transmute/transmute_undefined_repr.rs
+++ b/src/tools/clippy/clippy_lints/src/transmute/transmute_undefined_repr.rs
@@ -206,12 +206,12 @@ fn reduce_refs<'tcx>(cx: &LateContext<'tcx>, mut from_ty: Ty<'tcx>, mut to_ty: T
                 continue;
             },
             (&(ty::Ref(_, unsized_ty, _) | ty::RawPtr(unsized_ty, _)), _)
-                if !unsized_ty.is_sized(cx.tcx, cx.param_env) =>
+                if !unsized_ty.is_sized(cx.tcx, cx.typing_env()) =>
             {
                 (true, false)
             },
             (_, &(ty::Ref(_, unsized_ty, _) | ty::RawPtr(unsized_ty, _)))
-                if !unsized_ty.is_sized(cx.tcx, cx.param_env) =>
+                if !unsized_ty.is_sized(cx.tcx, cx.typing_env()) =>
             {
                 (false, true)
             },
diff --git a/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs b/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs
index 1a656088b17..de3456a8ba5 100644
--- a/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs
+++ b/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs
@@ -60,7 +60,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, hir_ty: &hir::Ty<'tcx>, qpath:
             // here because `mod.rs` guarantees this lint is only run on types outside of bodies and
             // is not run on locals.
             let ty = lower_ty(cx.tcx, hir_ty);
-            if ty.has_escaping_bound_vars() || !ty.is_sized(cx.tcx, cx.param_env) {
+            if ty.has_escaping_bound_vars() || !ty.is_sized(cx.tcx, cx.typing_env()) {
                 return false;
             }
             hir_ty.span
diff --git a/src/tools/clippy/clippy_lints/src/types/vec_box.rs b/src/tools/clippy/clippy_lints/src/types/vec_box.rs
index 230239335c6..9b236d3bda5 100644
--- a/src/tools/clippy/clippy_lints/src/types/vec_box.rs
+++ b/src/tools/clippy/clippy_lints/src/types/vec_box.rs
@@ -37,7 +37,7 @@ pub(super) fn check<'tcx>(
             && let boxed_alloc_ty = last.args.get(1)
             && let ty_ty = lower_ty(cx.tcx, boxed_ty)
             && !ty_ty.has_escaping_bound_vars()
-            && ty_ty.is_sized(cx.tcx, cx.param_env)
+            && ty_ty.is_sized(cx.tcx, cx.typing_env())
             && let Ok(ty_ty_size) = cx.layout_of(ty_ty).map(|l| l.size.bytes())
             && ty_ty_size < box_size_threshold
             // https://github.com/rust-lang/rust-clippy/issues/7114
diff --git a/src/tools/clippy/clippy_lints/src/unnecessary_box_returns.rs b/src/tools/clippy/clippy_lints/src/unnecessary_box_returns.rs
index 14f4aa6676b..34df1d5560a 100644
--- a/src/tools/clippy/clippy_lints/src/unnecessary_box_returns.rs
+++ b/src/tools/clippy/clippy_lints/src/unnecessary_box_returns.rs
@@ -82,7 +82,7 @@ impl UnnecessaryBoxReturns {
         // It's sometimes useful to return Box<T> if T is unsized, so don't lint those.
         // Also, don't lint if we know that T is very large, in which case returning
         // a Box<T> may be beneficial.
-        if boxed_ty.is_sized(cx.tcx, cx.param_env) && approx_ty_size(cx, boxed_ty) <= self.maximum_size {
+        if boxed_ty.is_sized(cx.tcx, cx.typing_env()) && approx_ty_size(cx, boxed_ty) <= self.maximum_size {
             span_lint_and_then(
                 cx,
                 UNNECESSARY_BOX_RETURNS,
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index f28e5c9ed0e..6408cc938cb 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -116,8 +116,8 @@ use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow};
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::layout::IntegerExt;
 use rustc_middle::ty::{
-    self as rustc_ty, Binder, BorrowKind, ClosureKind, EarlyBinder, FloatTy, GenericArgsRef, IntTy, ParamEnv,
-    ParamEnvAnd, Ty, TyCtxt, TypeVisitableExt, UintTy, UpvarCapture,
+    self as rustc_ty, Binder, BorrowKind, ClosureKind, EarlyBinder, FloatTy, GenericArgsRef, IntTy,
+    Ty, TyCtxt, TypeVisitableExt, UintTy, UpvarCapture,
 };
 use rustc_span::hygiene::{ExpnKind, MacroKind};
 use rustc_span::source_map::SourceMap;
@@ -2712,9 +2712,17 @@ pub fn walk_to_expr_usage<'tcx, T>(
 pub enum DefinedTy<'tcx> {
     // Used for locals and closures defined within the function.
     Hir(&'tcx hir::Ty<'tcx>),
-    /// Used for function signatures, and constant and static values. This includes the `ParamEnv`
-    /// from the definition site.
-    Mir(ParamEnvAnd<'tcx, Binder<'tcx, Ty<'tcx>>>),
+    /// Used for function signatures, and constant and static values. The type is
+    /// in the context of its definition site. We also track the `def_id` of its
+    /// definition site.
+    /// 
+    /// WARNING: As the `ty` in in the scope of the definition, not of the function
+    /// using it, you must be very careful with how you use it. Using it in the wrong
+    /// scope easily results in ICEs. 
+    Mir {
+        def_site_def_id: Option<DefId>,
+        ty: Binder<'tcx, Ty<'tcx>>,
+    },
 }
 
 /// The context an expressions value is used in.
@@ -2833,10 +2841,10 @@ impl<'tcx> ExprUseNode<'tcx> {
     pub fn defined_ty(&self, cx: &LateContext<'tcx>) -> Option<DefinedTy<'tcx>> {
         match *self {
             Self::LetStmt(LetStmt { ty: Some(ty), .. }) => Some(DefinedTy::Hir(ty)),
-            Self::ConstStatic(id) => Some(DefinedTy::Mir(
-                cx.param_env
-                    .and(Binder::dummy(cx.tcx.type_of(id).instantiate_identity())),
-            )),
+            Self::ConstStatic(id) => Some(DefinedTy::Mir {
+                def_site_def_id: Some(id.def_id.to_def_id()),
+                ty: Binder::dummy(cx.tcx.type_of(id).instantiate_identity()),
+        }),
             Self::Return(id) => {
                 if let Node::Expr(Expr {
                     kind: ExprKind::Closure(c),
@@ -2848,9 +2856,8 @@ impl<'tcx> ExprUseNode<'tcx> {
                         FnRetTy::Return(ty) => Some(DefinedTy::Hir(ty)),
                     }
                 } else {
-                    Some(DefinedTy::Mir(
-                        cx.param_env.and(cx.tcx.fn_sig(id).instantiate_identity().output()),
-                    ))
+                    let ty = cx.tcx.fn_sig(id).instantiate_identity().output();
+                    Some(DefinedTy::Mir { def_site_def_id: Some(id.def_id.to_def_id()), ty })
                 }
             },
             Self::Field(field) => match get_parent_expr_for_hir(cx, field.hir_id) {
@@ -2866,12 +2873,9 @@ impl<'tcx> ExprUseNode<'tcx> {
                             .find(|f| f.name == field.ident.name)
                             .map(|f| (adt, f))
                     })
-                    .map(|(adt, field_def)| {
-                        DefinedTy::Mir(
-                            cx.tcx
-                                .param_env(adt.did())
-                                .and(Binder::dummy(cx.tcx.type_of(field_def.did).instantiate_identity())),
-                        )
+                    .map(|(adt, field_def)| DefinedTy::Mir {
+                            def_site_def_id: Some(adt.did()),
+                            ty: Binder::dummy(cx.tcx.type_of(field_def.did).instantiate_identity()),
                     }),
                 _ => None,
             },
@@ -2880,17 +2884,19 @@ impl<'tcx> ExprUseNode<'tcx> {
                 let (hir_ty, ty) = sig.input_with_hir(i)?;
                 Some(match hir_ty {
                     Some(hir_ty) => DefinedTy::Hir(hir_ty),
-                    None => DefinedTy::Mir(
-                        sig.predicates_id()
-                            .map_or(ParamEnv::empty(), |id| cx.tcx.param_env(id))
-                            .and(ty),
-                    ),
+                    None => DefinedTy::Mir {
+                        def_site_def_id:  sig.predicates_id(),
+                        ty,
+                    }
                 })
             },
             Self::MethodArg(id, _, i) => {
                 let id = cx.typeck_results().type_dependent_def_id(id)?;
                 let sig = cx.tcx.fn_sig(id).skip_binder();
-                Some(DefinedTy::Mir(cx.tcx.param_env(id).and(sig.input(i))))
+                Some(DefinedTy::Mir {
+                    def_site_def_id: Some(id),
+                    ty: sig.input(i),
+                })
             },
             Self::LetStmt(_) | Self::FieldAccess(..) | Self::Callee | Self::Other | Self::AddrOf(..) => None,
         }
diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
index abadca71400..345c46f944a 100644
--- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
@@ -233,6 +233,7 @@ fn check_statement<'tcx>(
         | StatementKind::PlaceMention(..)
         | StatementKind::Coverage(..)
         | StatementKind::ConstEvalCounter
+        | StatementKind::BackwardIncompatibleDropHint { .. }
         | StatementKind::Nop => Ok(()),
     }
 }
diff --git a/src/tools/clippy/clippy_utils/src/ty.rs b/src/tools/clippy/clippy_utils/src/ty.rs
index 2aad867dc0d..3498606dfd3 100644
--- a/src/tools/clippy/clippy_utils/src/ty.rs
+++ b/src/tools/clippy/clippy_utils/src/ty.rs
@@ -19,7 +19,7 @@ use rustc_middle::ty::layout::ValidityRequirement;
 use rustc_middle::ty::{
     self, AdtDef, AliasTy, AssocItem, AssocKind, Binder, BoundRegion, FnSig, GenericArg, GenericArgKind,
     GenericArgsRef, GenericParamDefKind, IntTy, ParamEnv, Region, RegionKind, TraitRef, Ty, TyCtxt, TypeSuperVisitable,
-    TypeVisitable, TypeVisitableExt, TypeVisitor, TypingMode, UintTy, Upcast, VariantDef, VariantDiscr,
+    TypeVisitable, TypeVisitableExt, TypeVisitor, UintTy, Upcast, VariantDef, VariantDiscr,
 };
 use rustc_span::symbol::Ident;
 use rustc_span::{DUMMY_SP, Span, Symbol, sym};
@@ -38,7 +38,7 @@ pub use type_certainty::expr_type_is_certain;
 
 /// Checks if the given type implements copy.
 pub fn is_copy<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
-    ty.is_copy_modulo_regions(cx.tcx, cx.param_env)
+    ty.is_copy_modulo_regions(cx.tcx, cx.typing_env())
 }
 
 /// This checks whether a given type is known to implement Debug.
@@ -226,7 +226,7 @@ pub fn implements_trait<'tcx>(
     trait_id: DefId,
     args: &[GenericArg<'tcx>],
 ) -> bool {
-    implements_trait_with_env_from_iter(cx.tcx, cx.param_env, ty, trait_id, None, args.iter().map(|&x| Some(x)))
+    implements_trait_with_env_from_iter(cx.tcx, cx.typing_env(), ty, trait_id, None, args.iter().map(|&x| Some(x)))
 }
 
 /// Same as `implements_trait` but allows using a `ParamEnv` different from the lint context.
@@ -235,19 +235,19 @@ pub fn implements_trait<'tcx>(
 /// environment, used for checking const traits.
 pub fn implements_trait_with_env<'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env: ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     ty: Ty<'tcx>,
     trait_id: DefId,
     callee_id: Option<DefId>,
     args: &[GenericArg<'tcx>],
 ) -> bool {
-    implements_trait_with_env_from_iter(tcx, param_env, ty, trait_id, callee_id, args.iter().map(|&x| Some(x)))
+    implements_trait_with_env_from_iter(tcx, typing_env, ty, trait_id, callee_id, args.iter().map(|&x| Some(x)))
 }
 
 /// Same as `implements_trait_from_env` but takes the arguments as an iterator.
 pub fn implements_trait_with_env_from_iter<'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env: ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     ty: Ty<'tcx>,
     trait_id: DefId,
     callee_id: Option<DefId>,
@@ -268,7 +268,7 @@ pub fn implements_trait_with_env_from_iter<'tcx>(
         return false;
     }
 
-    let infcx = tcx.infer_ctxt().build(TypingMode::from_param_env(param_env));
+    let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
     let args = args
         .into_iter()
         .map(|arg| arg.into().unwrap_or_else(|| infcx.next_ty_var(DUMMY_SP).into()))
@@ -1239,12 +1239,12 @@ impl<'tcx> InteriorMut<'tcx> {
 
 pub fn make_normalized_projection_with_regions<'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env: ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     container_id: DefId,
     assoc_ty: Symbol,
     args: impl IntoIterator<Item = impl Into<GenericArg<'tcx>>>,
 ) -> Option<Ty<'tcx>> {
-    fn helper<'tcx>(tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ty: AliasTy<'tcx>) -> Option<Ty<'tcx>> {
+    fn helper<'tcx>(tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>, ty: AliasTy<'tcx>) -> Option<Ty<'tcx>> {
         #[cfg(debug_assertions)]
         if let Some((i, arg)) = ty
             .args
@@ -1261,10 +1261,8 @@ pub fn make_normalized_projection_with_regions<'tcx>(
             return None;
         }
         let cause = ObligationCause::dummy();
-        match tcx
-            .infer_ctxt()
-            .build(TypingMode::from_param_env(param_env))
-            .at(&cause, param_env)
+        let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
+        match infcx.at(&cause, param_env)
             .query_normalize(Ty::new_projection_from_args(tcx, ty.def_id, ty.args))
         {
             Ok(ty) => Some(ty.value),
@@ -1274,20 +1272,13 @@ pub fn make_normalized_projection_with_regions<'tcx>(
             },
         }
     }
-    helper(tcx, param_env, make_projection(tcx, container_id, assoc_ty, args)?)
+    helper(tcx, typing_env, make_projection(tcx, container_id, assoc_ty, args)?)
 }
 
-pub fn normalize_with_regions<'tcx>(tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
+pub fn normalize_with_regions<'tcx>(tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
     let cause = ObligationCause::dummy();
-    match tcx
-        .infer_ctxt()
-        .build(TypingMode::from_param_env(param_env))
-        .at(&cause, param_env)
-        .query_normalize(ty)
-    {
-        Ok(ty) => ty.value,
-        Err(_) => ty,
-    }
+    let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
+    infcx.at(&cause, param_env).query_normalize(ty).map_or(ty, |ty| ty.value)
 }
 
 /// Checks if the type is `core::mem::ManuallyDrop<_>`
diff --git a/src/tools/miri/rust-version b/src/tools/miri/rust-version
index 1fcd33752ec..effed0cd180 100644
--- a/src/tools/miri/rust-version
+++ b/src/tools/miri/rust-version
@@ -1 +1 @@
-875df370be806c837f58abb638329905e969ace4
+2d0ea7956c45de6e421fd579e2ded27be405dec6
diff --git a/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs b/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs
index 745316913d9..a855603eeb3 100644
--- a/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs
+++ b/src/tools/miri/src/borrow_tracker/stacked_borrows/mod.rs
@@ -71,7 +71,7 @@ impl NewPermission {
                         access: None,
                         protector: None,
                     }
-                } else if pointee.is_unpin(*cx.tcx, cx.param_env()) {
+                } else if pointee.is_unpin(*cx.tcx, cx.typing_env()) {
                     // A regular full mutable reference. On `FnEntry` this is `noalias` and `dereferenceable`.
                     NewPermission::Uniform {
                         perm: Permission::Unique,
@@ -129,7 +129,7 @@ impl NewPermission {
     fn from_box_ty<'tcx>(ty: Ty<'tcx>, kind: RetagKind, cx: &crate::MiriInterpCx<'tcx>) -> Self {
         // `ty` is not the `Box` but the field of the Box with this pointer (due to allocator handling).
         let pointee = ty.builtin_deref(true).unwrap();
-        if pointee.is_unpin(*cx.tcx, cx.param_env()) {
+        if pointee.is_unpin(*cx.tcx, cx.typing_env()) {
             // A regular box. On `FnEntry` this is `noalias`, but not `dereferenceable` (hence only
             // a weak protector).
             NewPermission::Uniform {
@@ -608,7 +608,7 @@ trait EvalContextPrivExt<'tcx, 'ecx>: crate::MiriInterpCxExt<'tcx> {
                 match new_perm {
                     NewPermission::Uniform { perm, .. } =>
                         write!(kind_str, "{perm:?} permission").unwrap(),
-                    NewPermission::FreezeSensitive { freeze_perm, .. } if ty.is_freeze(*this.tcx, this.param_env()) =>
+                    NewPermission::FreezeSensitive { freeze_perm, .. } if ty.is_freeze(*this.tcx, this.typing_env()) =>
                         write!(kind_str, "{freeze_perm:?} permission").unwrap(),
                     NewPermission::FreezeSensitive { freeze_perm, nonfreeze_perm, .. }  =>
                         write!(kind_str, "{freeze_perm:?}/{nonfreeze_perm:?} permission for frozen/non-frozen parts").unwrap(),
diff --git a/src/tools/miri/src/borrow_tracker/tree_borrows/mod.rs b/src/tools/miri/src/borrow_tracker/tree_borrows/mod.rs
index 255a3578aae..8469744bbc4 100644
--- a/src/tools/miri/src/borrow_tracker/tree_borrows/mod.rs
+++ b/src/tools/miri/src/borrow_tracker/tree_borrows/mod.rs
@@ -132,8 +132,8 @@ impl<'tcx> NewPermission {
         kind: RetagKind,
         cx: &crate::MiriInterpCx<'tcx>,
     ) -> Option<Self> {
-        let ty_is_freeze = pointee.is_freeze(*cx.tcx, cx.param_env());
-        let ty_is_unpin = pointee.is_unpin(*cx.tcx, cx.param_env());
+        let ty_is_freeze = pointee.is_freeze(*cx.tcx, cx.typing_env());
+        let ty_is_unpin = pointee.is_unpin(*cx.tcx, cx.typing_env());
         let is_protected = kind == RetagKind::FnEntry;
         // As demonstrated by `tests/fail/tree_borrows/reservedim_spurious_write.rs`,
         // interior mutability and protectors interact poorly.
@@ -164,10 +164,10 @@ impl<'tcx> NewPermission {
         zero_size: bool,
     ) -> Option<Self> {
         let pointee = ty.builtin_deref(true).unwrap();
-        pointee.is_unpin(*cx.tcx, cx.param_env()).then_some(()).map(|()| {
+        pointee.is_unpin(*cx.tcx, cx.typing_env()).then_some(()).map(|()| {
             // Regular `Unpin` box, give it `noalias` but only a weak protector
             // because it is valid to deallocate it within the function.
-            let ty_is_freeze = ty.is_freeze(*cx.tcx, cx.param_env());
+            let ty_is_freeze = ty.is_freeze(*cx.tcx, cx.typing_env());
             let protected = kind == RetagKind::FnEntry;
             let initial_state = Permission::new_reserved(ty_is_freeze, protected);
             Self {
@@ -521,7 +521,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         // Note: if we were to inline `new_reserved` below we would find out that
         // `ty_is_freeze` is eventually unused because it appears in a `ty_is_freeze || true`.
         // We are nevertheless including it here for clarity.
-        let ty_is_freeze = place.layout.ty.is_freeze(*this.tcx, this.param_env());
+        let ty_is_freeze = place.layout.ty.is_freeze(*this.tcx, this.typing_env());
         // Retag it. With protection! That is the entire point.
         let new_perm = NewPermission {
             initial_state: Permission::new_reserved(ty_is_freeze, /* protected */ true),
diff --git a/src/tools/miri/src/eval.rs b/src/tools/miri/src/eval.rs
index 63285e10cac..1df1d08802a 100644
--- a/src/tools/miri/src/eval.rs
+++ b/src/tools/miri/src/eval.rs
@@ -270,12 +270,8 @@ pub fn create_ecx<'tcx>(
 ) -> InterpResult<'tcx, InterpCx<'tcx, MiriMachine<'tcx>>> {
     let typing_env = ty::TypingEnv::fully_monomorphized();
     let layout_cx = LayoutCx::new(tcx, typing_env);
-    let mut ecx = InterpCx::new(
-        tcx,
-        rustc_span::DUMMY_SP,
-        typing_env.param_env,
-        MiriMachine::new(config, layout_cx),
-    );
+    let mut ecx =
+        InterpCx::new(tcx, rustc_span::DUMMY_SP, typing_env, MiriMachine::new(config, layout_cx));
 
     // Some parts of initialization require a full `InterpCx`.
     MiriMachine::late_init(&mut ecx, config, {
diff --git a/src/tools/miri/src/machine.rs b/src/tools/miri/src/machine.rs
index ff5c018a02b..814dc6d2b01 100644
--- a/src/tools/miri/src/machine.rs
+++ b/src/tools/miri/src/machine.rs
@@ -17,7 +17,9 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::static_assert_size;
 use rustc_middle::mir;
 use rustc_middle::query::TyCtxtAt;
-use rustc_middle::ty::layout::{HasTyCtxt, LayoutCx, LayoutError, LayoutOf, TyAndLayout};
+use rustc_middle::ty::layout::{
+    HasTyCtxt, HasTypingEnv, LayoutCx, LayoutError, LayoutOf, TyAndLayout,
+};
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_session::config::InliningThreshold;
 use rustc_span::def_id::{CrateNum, DefId};
diff --git a/src/tools/rust-analyzer/crates/parser/src/lexed_str.rs b/src/tools/rust-analyzer/crates/parser/src/lexed_str.rs
index 3c0eb1b42a6..c97596d5097 100644
--- a/src/tools/rust-analyzer/crates/parser/src/lexed_str.rs
+++ b/src/tools/rust-analyzer/crates/parser/src/lexed_str.rs
@@ -183,7 +183,7 @@ impl<'a> Converter<'a> {
                 rustc_lexer::TokenKind::Ident => {
                     SyntaxKind::from_keyword(token_text, self.edition).unwrap_or(IDENT)
                 }
-                rustc_lexer::TokenKind::InvalidPrefix | rustc_lexer::TokenKind::InvalidIdent => {
+                rustc_lexer::TokenKind::InvalidIdent => {
                     err = "Ident contains invalid characters";
                     IDENT
                 }
diff --git a/tests/crashes/113280.rs b/tests/crashes/113280.rs
deleted file mode 100644
index 86677f416fe..00000000000
--- a/tests/crashes/113280.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-//@ known-bug: #113280
-//@ only-x86_64
-
-#![feature(dyn_star, pointer_like_trait)]
-#![allow(incomplete_features)]
-
-use std::fmt::Debug;
-use std::marker::PointerLike;
-
-fn make_dyn_star<'a>(t: impl PointerLike + Debug + 'a) -> dyn* Debug + 'a {
-    f32::from_bits(0x1) as f64
-}
-
-fn main() {
-    println!("{:?}", make_dyn_star(Box::new(1i32)));
-}
diff --git a/tests/crashes/127676.rs b/tests/crashes/127676.rs
deleted file mode 100644
index 81149c2ef84..00000000000
--- a/tests/crashes/127676.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-//@ known-bug: #127676
-//@ edition:2018
-
-#![feature(dyn_star,const_async_blocks)]
-
-static S: dyn* Send + Sync = async { 42 };
-
-pub fn main() {}
diff --git a/tests/ui/drop/lint-tail-expr-drop-order-gated.rs b/tests/ui/drop/lint-tail-expr-drop-order-gated.rs
index fde542c756f..508e7bdbf99 100644
--- a/tests/ui/drop/lint-tail-expr-drop-order-gated.rs
+++ b/tests/ui/drop/lint-tail-expr-drop-order-gated.rs
@@ -1,9 +1,10 @@
-// This test is to demonstrate that the lint is gated behind Edition and
-// is triggered only for Edition 2021 and before.
+// This test ensures that `tail_expr_drop_order` does not activate in case Edition 2024 is used
+// because this is a migration lint.
+// Only `cargo fix --edition 2024` shall activate this lint.
 
 //@ check-pass
-//@ edition: 2024
 //@ compile-flags: -Z unstable-options
+//@ edition: 2024
 
 #![deny(tail_expr_drop_order)]
 
diff --git a/tests/ui/drop/lint-tail-expr-drop-order.rs b/tests/ui/drop/lint-tail-expr-drop-order.rs
index d61abae5187..0fabc1f085c 100644
--- a/tests/ui/drop/lint-tail-expr-drop-order.rs
+++ b/tests/ui/drop/lint-tail-expr-drop-order.rs
@@ -1,13 +1,26 @@
-//@ edition: 2021
-
 // Edition 2024 lint for change in drop order at tail expression
 // This lint is to capture potential change in program semantics
 // due to implementation of RFC 3606 <https://github.com/rust-lang/rfcs/pull/3606>
+//@ edition: 2021
+//@ build-fail
 
-#![deny(tail_expr_drop_order)]
+#![deny(tail_expr_drop_order)] //~ NOTE: the lint level is defined here
+#![allow(dropping_copy_types)]
 
 struct LoudDropper;
 impl Drop for LoudDropper {
+    //~^ NOTE: `#1` invokes this custom destructor
+    //~| NOTE: `x` invokes this custom destructor
+    //~| NOTE: `#1` invokes this custom destructor
+    //~| NOTE: `x` invokes this custom destructor
+    //~| NOTE: `#1` invokes this custom destructor
+    //~| NOTE: `x` invokes this custom destructor
+    //~| NOTE: `#1` invokes this custom destructor
+    //~| NOTE: `x` invokes this custom destructor
+    //~| NOTE: `#1` invokes this custom destructor
+    //~| NOTE: `future` invokes this custom destructor
+    //~| NOTE: `_x` invokes this custom destructor
+    //~| NOTE: `#1` invokes this custom destructor
     fn drop(&mut self) {
         // This destructor should be considered significant because it is a custom destructor
         // and we will assume that the destructor can generate side effects arbitrarily so that
@@ -23,30 +36,70 @@ impl LoudDropper {
 
 fn should_lint() -> i32 {
     let x = LoudDropper;
+    //~^ NOTE: `x` calls a custom destructor
+    //~| NOTE: `x` will be dropped later as of Edition 2024
     // Should lint
     x.get() + LoudDropper.get()
-    //~^ ERROR: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
+    //~^ ERROR: relative drop order changing in Rust 2024
+    //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+    //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
     //~| WARN: this changes meaning in Rust 2024
+    //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+    //~| NOTE: for more information, see issue #123739
 }
+//~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
 
-fn should_lint_closure() -> impl FnOnce() -> i32 {
+fn should_not_lint_closure() -> impl FnOnce() -> i32 {
     let x = LoudDropper;
-    move || x.get() + LoudDropper.get()
-    //~^ ERROR: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
-    //~| WARN: this changes meaning in Rust 2024
+    move || {
+        // Should not lint because ...
+        x.get() + LoudDropper.get()
+    }
+    // ^ closure captures like `x` are always dropped last by contract
+}
+
+fn should_lint_in_nested_items() {
+    fn should_lint_me() -> i32 {
+        let x = LoudDropper;
+        //~^ NOTE: `x` calls a custom destructor
+        //~| NOTE: `x` will be dropped later as of Edition 2024
+        // Should lint
+        x.get() + LoudDropper.get()
+        //~^ ERROR: relative drop order changing in Rust 2024
+        //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+        //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+        //~| WARN: this changes meaning in Rust 2024
+        //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+        //~| NOTE: for more information, see issue #123739
+    }
+    //~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
 }
 
+fn should_not_lint_params(x: LoudDropper) -> i32 {
+    // Should not lint because ...
+    x.get() + LoudDropper.get()
+}
+// ^ function parameters like `x` are always dropped last
+
 fn should_not_lint() -> i32 {
     let x = LoudDropper;
     // Should not lint
     x.get()
 }
 
-fn should_not_lint_in_nested_block() -> i32 {
+fn should_lint_in_nested_block() -> i32 {
     let x = LoudDropper;
-    // Should not lint because Edition 2021 drops temporaries in blocks earlier already
+    //~^ NOTE: `x` calls a custom destructor
+    //~| NOTE: `x` will be dropped later as of Edition 2024
     { LoudDropper.get() }
+    //~^ ERROR: relative drop order changing in Rust 2024
+    //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+    //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+    //~| WARN: this changes meaning in Rust 2024
+    //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+    //~| NOTE: for more information, see issue #123739
 }
+//~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
 
 fn should_not_lint_in_match_arm() -> i32 {
     let x = LoudDropper;
@@ -56,14 +109,144 @@ fn should_not_lint_in_match_arm() -> i32 {
     }
 }
 
-fn should_lint_in_nested_items() {
-    fn should_lint_me() -> i32 {
+fn should_not_lint_when_consumed() -> (LoudDropper, i32) {
+    let x = LoudDropper;
+    // Should not lint because `LoudDropper` is consumed by the return value
+    (LoudDropper, x.get())
+}
+
+struct MyAdt {
+    a: LoudDropper,
+    b: LoudDropper,
+}
+
+fn should_not_lint_when_consumed_in_ctor() -> MyAdt {
+    let a = LoudDropper;
+    // Should not lint
+    MyAdt { a, b: LoudDropper }
+}
+
+fn should_not_lint_when_moved() -> i32 {
+    let x = LoudDropper;
+    drop(x);
+    // Should not lint because `x` is not live
+    LoudDropper.get()
+}
+
+fn should_lint_into_async_body() -> i32 {
+    async fn f() {
+        async fn f() {}
         let x = LoudDropper;
-        // Should lint
-        x.get() + LoudDropper.get()
-        //~^ ERROR: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
-        //~| WARN: this changes meaning in Rust 2024
+        f().await;
+        drop(x);
+    }
+
+    let future = f();
+    //~^ NOTE: `future` calls a custom destructor
+    //~| NOTE: `future` will be dropped later as of Edition 2024
+    LoudDropper.get()
+    //~^ ERROR: relative drop order changing in Rust 2024
+    //~| WARN: this changes meaning in Rust 2024
+    //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+    //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+    //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+    //~| NOTE: for more information, see issue #123739
+}
+//~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
+
+fn should_lint_generics<T: Default>() -> &'static str {
+    fn extract<T>(_: &T) -> &'static str {
+        todo!()
+    }
+    let x = T::default();
+    //~^ NOTE: `x` calls a custom destructor
+    //~| NOTE: `x` will be dropped later as of Edition 2024
+    extract(&T::default())
+    //~^ ERROR: relative drop order changing in Rust 2024
+    //~| WARN: this changes meaning in Rust 2024
+    //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+    //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+    //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+    //~| NOTE: for more information, see issue #123739
+}
+//~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
+
+fn should_lint_adt() -> i32 {
+    let x: Result<LoudDropper, ()> = Ok(LoudDropper);
+    //~^ NOTE: `x` calls a custom destructor
+    //~| NOTE: `x` will be dropped later as of Edition 2024
+    LoudDropper.get()
+    //~^ ERROR: relative drop order changing in Rust 2024
+    //~| WARN: this changes meaning in Rust 2024
+    //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+    //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+    //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+    //~| NOTE: for more information, see issue #123739
+}
+//~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
+
+fn should_not_lint_insign_dtor() -> i32 {
+    let x = String::new();
+    LoudDropper.get()
+}
+
+fn should_lint_with_dtor_span() -> i32 {
+    struct LoudDropper3;
+    impl Drop for LoudDropper3 {
+        //~^ NOTE: `#1` invokes this custom destructor
+        fn drop(&mut self) {
+            println!("loud drop");
+        }
     }
+    impl LoudDropper3 {
+        fn get(&self) -> i32 {
+            0
+        }
+    }
+    struct LoudDropper2;
+    impl Drop for LoudDropper2 {
+        //~^ NOTE: `x` invokes this custom destructor
+        fn drop(&mut self) {
+            println!("loud drop");
+        }
+    }
+    impl LoudDropper2 {
+        fn get(&self) -> i32 {
+            0
+        }
+    }
+
+    let x = LoudDropper2;
+    //~^ NOTE: `x` calls a custom destructor
+    //~| NOTE: `x` will be dropped later as of Edition 2024
+    LoudDropper3.get()
+    //~^ ERROR: relative drop order changing in Rust 2024
+    //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+    //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+    //~| WARN: this changes meaning in Rust 2024
+    //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+    //~| NOTE: for more information, see issue #123739
+}
+//~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
+
+fn should_lint_with_transient_drops() {
+    drop((
+        {
+            LoudDropper.get()
+            //~^ ERROR: relative drop order changing in Rust 2024
+            //~| NOTE: this value will be stored in a temporary; let us call it `#1`
+            //~| NOTE: up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+            //~| WARN: this changes meaning in Rust 2024
+            //~| NOTE: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects
+            //~| NOTE: for more information, see issue #123739
+        },
+        {
+            let _x = LoudDropper;
+            //~^ NOTE: `_x` calls a custom destructor
+            //~| NOTE: `_x` will be dropped later as of Edition 2024
+        },
+    ));
+    //~^ NOTE: now the temporary value is dropped here, before the local variables in the block or statement
 }
 
 fn main() {}
diff --git a/tests/ui/drop/lint-tail-expr-drop-order.stderr b/tests/ui/drop/lint-tail-expr-drop-order.stderr
index 6775c4ce6d1..f0da24605e6 100644
--- a/tests/ui/drop/lint-tail-expr-drop-order.stderr
+++ b/tests/ui/drop/lint-tail-expr-drop-order.stderr
@@ -1,42 +1,335 @@
-error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
-  --> $DIR/lint-tail-expr-drop-order.rs:27:15
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:42:15
    |
 LL |     let x = LoudDropper;
-   |         - these values have significant drop implementation and will observe changes in drop order under Edition 2024
-LL |     // Should lint
+   |         -
+   |         |
+   |         `x` calls a custom destructor
+   |         `x` will be dropped later as of Edition 2024
+...
 LL |     x.get() + LoudDropper.get()
    |               ^^^^^^^^^^^
+   |               |
+   |               this value will be stored in a temporary; let us call it `#1`
+   |               up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL | }
+   | - now the temporary value is dropped here, before the local variables in the block or statement
    |
    = warning: this changes meaning in Rust 2024
    = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+note: `#1` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+note: `x` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 note: the lint level is defined here
   --> $DIR/lint-tail-expr-drop-order.rs:7:9
    |
 LL | #![deny(tail_expr_drop_order)]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
-  --> $DIR/lint-tail-expr-drop-order.rs:34:23
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:67:19
+   |
+LL |         let x = LoudDropper;
+   |             -
+   |             |
+   |             `x` calls a custom destructor
+   |             `x` will be dropped later as of Edition 2024
+...
+LL |         x.get() + LoudDropper.get()
+   |                   ^^^^^^^^^^^
+   |                   |
+   |                   this value will be stored in a temporary; let us call it `#1`
+   |                   up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL |     }
+   |     - now the temporary value is dropped here, before the local variables in the block or statement
+   |
+   = warning: this changes meaning in Rust 2024
+   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+note: `#1` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+note: `x` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
+
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:94:7
    |
 LL |     let x = LoudDropper;
-   |         - these values have significant drop implementation and will observe changes in drop order under Edition 2024
-LL |     move || x.get() + LoudDropper.get()
-   |                       ^^^^^^^^^^^
+   |         -
+   |         |
+   |         `x` calls a custom destructor
+   |         `x` will be dropped later as of Edition 2024
+...
+LL |     { LoudDropper.get() }
+   |       ^^^^^^^^^^^
+   |       |
+   |       this value will be stored in a temporary; let us call it `#1`
+   |       up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL | }
+   | - now the temporary value is dropped here, before the local variables in the block or statement
    |
    = warning: this changes meaning in Rust 2024
    = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+note: `#1` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+note: `x` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 
-error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
-  --> $DIR/lint-tail-expr-drop-order.rs:63:19
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:147:5
    |
-LL |         let x = LoudDropper;
-   |             - these values have significant drop implementation and will observe changes in drop order under Edition 2024
-LL |         // Should lint
-LL |         x.get() + LoudDropper.get()
-   |                   ^^^^^^^^^^^
+LL |     let future = f();
+   |         ------
+   |         |
+   |         `future` calls a custom destructor
+   |         `future` will be dropped later as of Edition 2024
+...
+LL |     LoudDropper.get()
+   |     ^^^^^^^^^^^
+   |     |
+   |     this value will be stored in a temporary; let us call it `#1`
+   |     up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL | }
+   | - now the temporary value is dropped here, before the local variables in the block or statement
    |
    = warning: this changes meaning in Rust 2024
    = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+note: `#1` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+note: `future` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
+
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:164:14
+   |
+LL |     let x = T::default();
+   |         -
+   |         |
+   |         `x` calls a custom destructor
+   |         `x` will be dropped later as of Edition 2024
+...
+LL |     extract(&T::default())
+   |              ^^^^^^^^^^^^
+   |              |
+   |              this value will be stored in a temporary; let us call it `#1`
+   |              up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL | }
+   | - now the temporary value is dropped here, before the local variables in the block or statement
+   |
+   = warning: this changes meaning in Rust 2024
+   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
+
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:178:5
+   |
+LL |     let x: Result<LoudDropper, ()> = Ok(LoudDropper);
+   |         -
+   |         |
+   |         `x` calls a custom destructor
+   |         `x` will be dropped later as of Edition 2024
+...
+LL |     LoudDropper.get()
+   |     ^^^^^^^^^^^
+   |     |
+   |     this value will be stored in a temporary; let us call it `#1`
+   |     up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL | }
+   | - now the temporary value is dropped here, before the local variables in the block or statement
+   |
+   = warning: this changes meaning in Rust 2024
+   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+note: `#1` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+note: `x` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
+
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:222:5
+   |
+LL |     let x = LoudDropper2;
+   |         -
+   |         |
+   |         `x` calls a custom destructor
+   |         `x` will be dropped later as of Edition 2024
+...
+LL |     LoudDropper3.get()
+   |     ^^^^^^^^^^^^
+   |     |
+   |     this value will be stored in a temporary; let us call it `#1`
+   |     up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL | }
+   | - now the temporary value is dropped here, before the local variables in the block or statement
+   |
+   = warning: this changes meaning in Rust 2024
+   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+note: `#1` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:195:5
+   |
+LL | /     impl Drop for LoudDropper3 {
+LL | |
+LL | |         fn drop(&mut self) {
+LL | |             println!("loud drop");
+LL | |         }
+LL | |     }
+   | |_____^
+note: `x` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:207:5
+   |
+LL | /     impl Drop for LoudDropper2 {
+LL | |
+LL | |         fn drop(&mut self) {
+LL | |             println!("loud drop");
+LL | |         }
+LL | |     }
+   | |_____^
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
+
+error: relative drop order changing in Rust 2024
+  --> $DIR/lint-tail-expr-drop-order.rs:235:13
+   |
+LL |             LoudDropper.get()
+   |             ^^^^^^^^^^^
+   |             |
+   |             this value will be stored in a temporary; let us call it `#1`
+   |             up until Edition 2021 `#1` is dropped last but will be dropped earlier in Edition 2024
+...
+LL |             let _x = LoudDropper;
+   |                 --
+   |                 |
+   |                 `_x` calls a custom destructor
+   |                 `_x` will be dropped later as of Edition 2024
+...
+LL |     ));
+   |       - now the temporary value is dropped here, before the local variables in the block or statement
+   |
+   = warning: this changes meaning in Rust 2024
+   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
+note: `#1` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+note: `_x` invokes this custom destructor
+  --> $DIR/lint-tail-expr-drop-order.rs:11:1
+   |
+LL | / impl Drop for LoudDropper {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     }
+LL | | }
+   | |_^
+   = note: most of the time, changing drop order is harmless; inspect the `impl Drop`s for side effects like releasing locks or sending messages
 
-error: aborting due to 3 previous errors
+error: aborting due to 8 previous errors
 
diff --git a/tests/ui/dyn-star/async-block-dyn-star.rs b/tests/ui/dyn-star/async-block-dyn-star.rs
new file mode 100644
index 00000000000..9bffd6c6725
--- /dev/null
+++ b/tests/ui/dyn-star/async-block-dyn-star.rs
@@ -0,0 +1,9 @@
+//@ edition:2018
+
+#![feature(dyn_star, const_async_blocks)]
+//~^ WARN the feature `dyn_star` is incomplete
+
+static S: dyn* Send + Sync = async { 42 };
+//~^ needs to have the same ABI as a pointer
+
+pub fn main() {}
diff --git a/tests/ui/dyn-star/async-block-dyn-star.stderr b/tests/ui/dyn-star/async-block-dyn-star.stderr
new file mode 100644
index 00000000000..f62c85c0ad2
--- /dev/null
+++ b/tests/ui/dyn-star/async-block-dyn-star.stderr
@@ -0,0 +1,20 @@
+warning: the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/async-block-dyn-star.rs:3:12
+   |
+LL | #![feature(dyn_star, const_async_blocks)]
+   |            ^^^^^^^^
+   |
+   = note: see issue #102425 <https://github.com/rust-lang/rust/issues/102425> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0277]: `{async block@$DIR/async-block-dyn-star.rs:6:30: 6:35}` needs to have the same ABI as a pointer
+  --> $DIR/async-block-dyn-star.rs:6:30
+   |
+LL | static S: dyn* Send + Sync = async { 42 };
+   |                              ^^^^^^^^^^^^ `{async block@$DIR/async-block-dyn-star.rs:6:30: 6:35}` needs to be a pointer-like type
+   |
+   = help: the trait `PointerLike` is not implemented for `{async block@$DIR/async-block-dyn-star.rs:6:30: 6:35}`
+
+error: aborting due to 1 previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.current.stderr b/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.current.stderr
index 7b5ea7bb707..a0aff69f396 100644
--- a/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.current.stderr
+++ b/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.current.stderr
@@ -1,14 +1,17 @@
 error[E0277]: `&T` needs to have the same ABI as a pointer
   --> $DIR/check-size-at-cast-polymorphic-bad.rs:15:15
    |
+LL | fn polymorphic<T: Debug + ?Sized>(t: &T) {
+   |                - this type parameter needs to be `Sized`
 LL |     dyn_debug(t);
    |               ^ `&T` needs to be a pointer-like type
    |
-   = help: the trait `PointerLike` is not implemented for `&T`
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
+   = note: required for `&T` to implement `PointerLike`
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+LL - fn polymorphic<T: Debug + ?Sized>(t: &T) {
+LL + fn polymorphic<T: Debug>(t: &T) {
    |
-LL | fn polymorphic<T: Debug + ?Sized>(t: &T) where &T: PointerLike {
-   |                                          +++++++++++++++++++++
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.next.stderr b/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.next.stderr
index 7b5ea7bb707..a0aff69f396 100644
--- a/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.next.stderr
+++ b/tests/ui/dyn-star/check-size-at-cast-polymorphic-bad.next.stderr
@@ -1,14 +1,17 @@
 error[E0277]: `&T` needs to have the same ABI as a pointer
   --> $DIR/check-size-at-cast-polymorphic-bad.rs:15:15
    |
+LL | fn polymorphic<T: Debug + ?Sized>(t: &T) {
+   |                - this type parameter needs to be `Sized`
 LL |     dyn_debug(t);
    |               ^ `&T` needs to be a pointer-like type
    |
-   = help: the trait `PointerLike` is not implemented for `&T`
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
+   = note: required for `&T` to implement `PointerLike`
+help: consider removing the `?Sized` bound to make the type parameter `Sized`
+   |
+LL - fn polymorphic<T: Debug + ?Sized>(t: &T) {
+LL + fn polymorphic<T: Debug>(t: &T) {
    |
-LL | fn polymorphic<T: Debug + ?Sized>(t: &T) where &T: PointerLike {
-   |                                          +++++++++++++++++++++
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/dyn-star/drop.rs b/tests/ui/dyn-star/drop.rs
index ca86f1b5b01..bc746331527 100644
--- a/tests/ui/dyn-star/drop.rs
+++ b/tests/ui/dyn-star/drop.rs
@@ -1,13 +1,18 @@
 //@ run-pass
 //@ check-run-results
-#![feature(dyn_star)]
+#![feature(dyn_star, pointer_like_trait)]
 #![allow(incomplete_features)]
 
 use std::fmt::Debug;
+use std::marker::PointerLike;
 
 #[derive(Debug)]
+#[repr(transparent)]
 struct Foo(#[allow(dead_code)] usize);
 
+// FIXME(dyn_star): Make this into a derive.
+impl PointerLike for Foo {}
+
 impl Drop for Foo {
     fn drop(&mut self) {
         println!("destructor called");
diff --git a/tests/ui/dyn-star/enum-cast.rs b/tests/ui/dyn-star/enum-cast.rs
index 6e895e9527a..3cc7390eb12 100644
--- a/tests/ui/dyn-star/enum-cast.rs
+++ b/tests/ui/dyn-star/enum-cast.rs
@@ -3,13 +3,18 @@
 // This used to ICE, because the compiler confused a pointer-like to dyn* coercion
 // with a c-like enum to integer cast.
 
-#![feature(dyn_star)]
+#![feature(dyn_star, pointer_like_trait)]
 #![expect(incomplete_features)]
 
+use std::marker::PointerLike;
+
+#[repr(transparent)]
 enum E {
     Num(usize),
 }
 
+impl PointerLike for E {}
+
 trait Trait {}
 impl Trait for E {}
 
diff --git a/tests/ui/dyn-star/error.rs b/tests/ui/dyn-star/error.rs
index d8261387efa..7288596f3fa 100644
--- a/tests/ui/dyn-star/error.rs
+++ b/tests/ui/dyn-star/error.rs
@@ -7,7 +7,7 @@ trait Foo {}
 
 fn make_dyn_star() {
     let i = 42;
-    let dyn_i: dyn* Foo = i; //~ ERROR trait bound `{integer}: Foo` is not satisfied
+    let dyn_i: dyn* Foo = i; //~ ERROR trait bound `usize: Foo` is not satisfied
 }
 
 fn main() {}
diff --git a/tests/ui/dyn-star/error.stderr b/tests/ui/dyn-star/error.stderr
index a9f4a054519..55981c03bac 100644
--- a/tests/ui/dyn-star/error.stderr
+++ b/tests/ui/dyn-star/error.stderr
@@ -1,8 +1,8 @@
-error[E0277]: the trait bound `{integer}: Foo` is not satisfied
+error[E0277]: the trait bound `usize: Foo` is not satisfied
   --> $DIR/error.rs:10:27
    |
 LL |     let dyn_i: dyn* Foo = i;
-   |                           ^ the trait `Foo` is not implemented for `{integer}`
+   |                           ^ the trait `Foo` is not implemented for `usize`
    |
 help: this trait has no implementations, consider adding one
   --> $DIR/error.rs:6:1
diff --git a/tests/ui/dyn-star/float-as-dyn-star.rs b/tests/ui/dyn-star/float-as-dyn-star.rs
new file mode 100644
index 00000000000..1b629c64c25
--- /dev/null
+++ b/tests/ui/dyn-star/float-as-dyn-star.rs
@@ -0,0 +1,16 @@
+//@ only-x86_64
+
+#![feature(dyn_star, pointer_like_trait)]
+//~^ WARN the feature `dyn_star` is incomplete
+
+use std::fmt::Debug;
+use std::marker::PointerLike;
+
+fn make_dyn_star() -> dyn* Debug + 'static {
+    f32::from_bits(0x1) as f64
+    //~^ ERROR `f64` needs to have the same ABI as a pointer
+}
+
+fn main() {
+    println!("{:?}", make_dyn_star());
+}
diff --git a/tests/ui/dyn-star/float-as-dyn-star.stderr b/tests/ui/dyn-star/float-as-dyn-star.stderr
new file mode 100644
index 00000000000..9caba512e5f
--- /dev/null
+++ b/tests/ui/dyn-star/float-as-dyn-star.stderr
@@ -0,0 +1,21 @@
+warning: the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/float-as-dyn-star.rs:3:12
+   |
+LL | #![feature(dyn_star, pointer_like_trait)]
+   |            ^^^^^^^^
+   |
+   = note: see issue #102425 <https://github.com/rust-lang/rust/issues/102425> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0277]: `f64` needs to have the same ABI as a pointer
+  --> $DIR/float-as-dyn-star.rs:10:5
+   |
+LL |     f32::from_bits(0x1) as f64
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ `f64` needs to be a pointer-like type
+   |
+   = help: the trait `PointerLike` is not implemented for `f64`
+   = help: the trait `PointerLike` is implemented for `usize`
+
+error: aborting due to 1 previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/dyn-star/upcast.stderr b/tests/ui/dyn-star/upcast.stderr
index adef9525bf1..801e1c233c1 100644
--- a/tests/ui/dyn-star/upcast.stderr
+++ b/tests/ui/dyn-star/upcast.stderr
@@ -7,6 +7,14 @@ LL | #![feature(dyn_star, trait_upcasting)]
    = note: see issue #102425 <https://github.com/rust-lang/rust/issues/102425> for more information
    = note: `#[warn(incomplete_features)]` on by default
 
+error[E0277]: `W` needs to have the same ABI as a pointer
+  --> $DIR/upcast.rs:28:23
+   |
+LL |     let w: dyn* Foo = W(0);
+   |                       ^^^^ `W` needs to be a pointer-like type
+   |
+   = help: the trait `PointerLike` is not implemented for `W`
+
 error[E0277]: `dyn* Foo` needs to have the same ABI as a pointer
   --> $DIR/upcast.rs:30:23
    |
@@ -15,6 +23,6 @@ LL |     let w: dyn* Bar = w;
    |
    = help: the trait `PointerLike` is not implemented for `dyn* Foo`
 
-error: aborting due to 1 previous error; 1 warning emitted
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/lint/dangling-pointers-from-temporaries/types.rs b/tests/ui/lint/dangling-pointers-from-temporaries/types.rs
index 2b515d3e6d5..17c3eca89e2 100644
--- a/tests/ui/lint/dangling-pointers-from-temporaries/types.rs
+++ b/tests/ui/lint/dangling-pointers-from-temporaries/types.rs
@@ -1,6 +1,7 @@
 #![deny(dangling_pointers_from_temporaries)]
+#![feature(sync_unsafe_cell)]
 
-use std::cell::Cell;
+use std::cell::{Cell, SyncUnsafeCell, UnsafeCell};
 use std::ffi::{CStr, CString};
 use std::mem::MaybeUninit;
 
@@ -47,6 +48,10 @@ fn main() {
     //~^ ERROR a dangling pointer will be produced because the temporary `MaybeUninit<u8>` will be dropped
     declval::<Vec<AsPtrFake>>().as_ptr();
     //~^ ERROR a dangling pointer will be produced because the temporary `Vec<AsPtrFake>` will be dropped
+    declval::<UnsafeCell<u8>>().get();
+    //~^ ERROR a dangling pointer will be produced because the temporary `UnsafeCell<u8>` will be dropped
+    declval::<SyncUnsafeCell<u8>>().get();
+    //~^ ERROR a dangling pointer will be produced because the temporary `SyncUnsafeCell<u8>` will be dropped
     declval::<Box<AsPtrFake>>().as_ptr();
     declval::<AsPtrFake>().as_ptr();
 }
diff --git a/tests/ui/lint/dangling-pointers-from-temporaries/types.stderr b/tests/ui/lint/dangling-pointers-from-temporaries/types.stderr
index c582a4c6540..250ed6dc9e3 100644
--- a/tests/ui/lint/dangling-pointers-from-temporaries/types.stderr
+++ b/tests/ui/lint/dangling-pointers-from-temporaries/types.stderr
@@ -1,5 +1,5 @@
 error: a dangling pointer will be produced because the temporary `CString` will be dropped
-  --> $DIR/types.rs:20:26
+  --> $DIR/types.rs:21:26
    |
 LL |     declval::<CString>().as_ptr();
    |     -------------------- ^^^^^^ this pointer will immediately be invalid
@@ -15,7 +15,7 @@ LL | #![deny(dangling_pointers_from_temporaries)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: a dangling pointer will be produced because the temporary `String` will be dropped
-  --> $DIR/types.rs:22:25
+  --> $DIR/types.rs:23:25
    |
 LL |     declval::<String>().as_ptr();
    |     ------------------- ^^^^^^ this pointer will immediately be invalid
@@ -26,7 +26,7 @@ LL |     declval::<String>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Vec<u8>` will be dropped
-  --> $DIR/types.rs:24:26
+  --> $DIR/types.rs:25:26
    |
 LL |     declval::<Vec<u8>>().as_ptr();
    |     -------------------- ^^^^^^ this pointer will immediately be invalid
@@ -37,7 +37,7 @@ LL |     declval::<Vec<u8>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<CString>` will be dropped
-  --> $DIR/types.rs:26:31
+  --> $DIR/types.rs:27:31
    |
 LL |     declval::<Box<CString>>().as_ptr();
    |     ------------------------- ^^^^^^ this pointer will immediately be invalid
@@ -48,7 +48,7 @@ LL |     declval::<Box<CString>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<[u8]>` will be dropped
-  --> $DIR/types.rs:28:28
+  --> $DIR/types.rs:29:28
    |
 LL |     declval::<Box<[u8]>>().as_ptr();
    |     ---------------------- ^^^^^^ this pointer will immediately be invalid
@@ -59,7 +59,7 @@ LL |     declval::<Box<[u8]>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<str>` will be dropped
-  --> $DIR/types.rs:30:27
+  --> $DIR/types.rs:31:27
    |
 LL |     declval::<Box<str>>().as_ptr();
    |     --------------------- ^^^^^^ this pointer will immediately be invalid
@@ -70,7 +70,7 @@ LL |     declval::<Box<str>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<CStr>` will be dropped
-  --> $DIR/types.rs:32:28
+  --> $DIR/types.rs:33:28
    |
 LL |     declval::<Box<CStr>>().as_ptr();
    |     ---------------------- ^^^^^^ this pointer will immediately be invalid
@@ -81,7 +81,7 @@ LL |     declval::<Box<CStr>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `[u8; 10]` will be dropped
-  --> $DIR/types.rs:34:27
+  --> $DIR/types.rs:35:27
    |
 LL |     declval::<[u8; 10]>().as_ptr();
    |     --------------------- ^^^^^^ this pointer will immediately be invalid
@@ -92,7 +92,7 @@ LL |     declval::<[u8; 10]>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<[u8; 10]>` will be dropped
-  --> $DIR/types.rs:36:32
+  --> $DIR/types.rs:37:32
    |
 LL |     declval::<Box<[u8; 10]>>().as_ptr();
    |     -------------------------- ^^^^^^ this pointer will immediately be invalid
@@ -103,7 +103,7 @@ LL |     declval::<Box<[u8; 10]>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<Vec<u8>>` will be dropped
-  --> $DIR/types.rs:38:31
+  --> $DIR/types.rs:39:31
    |
 LL |     declval::<Box<Vec<u8>>>().as_ptr();
    |     ------------------------- ^^^^^^ this pointer will immediately be invalid
@@ -114,7 +114,7 @@ LL |     declval::<Box<Vec<u8>>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<String>` will be dropped
-  --> $DIR/types.rs:40:30
+  --> $DIR/types.rs:41:30
    |
 LL |     declval::<Box<String>>().as_ptr();
    |     ------------------------ ^^^^^^ this pointer will immediately be invalid
@@ -125,7 +125,7 @@ LL |     declval::<Box<String>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Box<Box<Box<Box<[u8]>>>>` will be dropped
-  --> $DIR/types.rs:42:43
+  --> $DIR/types.rs:43:43
    |
 LL |     declval::<Box<Box<Box<Box<[u8]>>>>>().as_ptr();
    |     ------------------------------------- ^^^^^^ this pointer will immediately be invalid
@@ -136,7 +136,7 @@ LL |     declval::<Box<Box<Box<Box<[u8]>>>>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Cell<u8>` will be dropped
-  --> $DIR/types.rs:44:27
+  --> $DIR/types.rs:45:27
    |
 LL |     declval::<Cell<u8>>().as_ptr();
    |     --------------------- ^^^^^^ this pointer will immediately be invalid
@@ -147,7 +147,7 @@ LL |     declval::<Cell<u8>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `MaybeUninit<u8>` will be dropped
-  --> $DIR/types.rs:46:34
+  --> $DIR/types.rs:47:34
    |
 LL |     declval::<MaybeUninit<u8>>().as_ptr();
    |     ---------------------------- ^^^^^^ this pointer will immediately be invalid
@@ -158,7 +158,7 @@ LL |     declval::<MaybeUninit<u8>>().as_ptr();
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
 error: a dangling pointer will be produced because the temporary `Vec<AsPtrFake>` will be dropped
-  --> $DIR/types.rs:48:33
+  --> $DIR/types.rs:49:33
    |
 LL |     declval::<Vec<AsPtrFake>>().as_ptr();
    |     --------------------------- ^^^^^^ this pointer will immediately be invalid
@@ -168,5 +168,27 @@ LL |     declval::<Vec<AsPtrFake>>().as_ptr();
    = note: pointers do not have a lifetime; when calling `as_ptr` the `Vec<AsPtrFake>` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
    = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
 
-error: aborting due to 15 previous errors
+error: a dangling pointer will be produced because the temporary `UnsafeCell<u8>` will be dropped
+  --> $DIR/types.rs:51:33
+   |
+LL |     declval::<UnsafeCell<u8>>().get();
+   |     --------------------------- ^^^ this pointer will immediately be invalid
+   |     |
+   |     this `UnsafeCell<u8>` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
+   |
+   = note: pointers do not have a lifetime; when calling `get` the `UnsafeCell<u8>` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
+   = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
+
+error: a dangling pointer will be produced because the temporary `SyncUnsafeCell<u8>` will be dropped
+  --> $DIR/types.rs:53:37
+   |
+LL |     declval::<SyncUnsafeCell<u8>>().get();
+   |     ------------------------------- ^^^ this pointer will immediately be invalid
+   |     |
+   |     this `SyncUnsafeCell<u8>` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
+   |
+   = note: pointers do not have a lifetime; when calling `get` the `SyncUnsafeCell<u8>` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
+   = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
+
+error: aborting due to 17 previous errors
 
diff --git a/tests/ui/thir-print/thir-flat-const-variant.stdout b/tests/ui/thir-print/thir-flat-const-variant.stdout
index 1840be7885b..5588cfdfa5c 100644
--- a/tests/ui/thir-print/thir-flat-const-variant.stdout
+++ b/tests/ui/thir-print/thir-flat-const-variant.stdout
@@ -11,9 +11,12 @@ Thir {
                 fields: [],
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:12:32: 12:34 (#0),
         },
         Expr {
@@ -25,9 +28,12 @@ Thir {
                 value: e0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:12:32: 12:34 (#0),
         },
         Expr {
@@ -47,9 +53,12 @@ Thir {
                 },
             ),
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:12:23: 12:35 (#0),
         },
         Expr {
@@ -61,9 +70,12 @@ Thir {
                 value: e2,
             },
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:12:23: 12:35 (#0),
         },
     ],
@@ -84,9 +96,12 @@ Thir {
                 fields: [],
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:13:33: 13:35 (#0),
         },
         Expr {
@@ -98,9 +113,12 @@ Thir {
                 value: e0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:13:33: 13:35 (#0),
         },
         Expr {
@@ -120,9 +138,12 @@ Thir {
                 },
             ),
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:13:23: 13:36 (#0),
         },
         Expr {
@@ -134,9 +155,12 @@ Thir {
                 value: e2,
             },
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:13:23: 13:36 (#0),
         },
     ],
@@ -157,9 +181,12 @@ Thir {
                 fields: [],
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:14:33: 14:35 (#0),
         },
         Expr {
@@ -171,9 +198,12 @@ Thir {
                 value: e0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:14:33: 14:35 (#0),
         },
         Expr {
@@ -193,9 +223,12 @@ Thir {
                 },
             ),
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:14:24: 14:36 (#0),
         },
         Expr {
@@ -207,9 +240,12 @@ Thir {
                 value: e2,
             },
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:14:24: 14:36 (#0),
         },
     ],
@@ -230,9 +266,12 @@ Thir {
                 fields: [],
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:15:34: 15:36 (#0),
         },
         Expr {
@@ -244,9 +283,12 @@ Thir {
                 value: e0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:15:34: 15:36 (#0),
         },
         Expr {
@@ -266,9 +308,12 @@ Thir {
                 },
             ),
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:15:24: 15:37 (#0),
         },
         Expr {
@@ -280,9 +325,12 @@ Thir {
                 value: e2,
             },
             ty: Foo,
-            temp_lifetime: Some(
-                Node(3),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(3),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:15:24: 15:37 (#0),
         },
     ],
@@ -312,9 +360,12 @@ Thir {
                 block: b0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(2),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(2),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:18:11: 18:13 (#0),
         },
         Expr {
@@ -326,9 +377,12 @@ Thir {
                 value: e0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(2),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(2),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat-const-variant.rs:18:11: 18:13 (#0),
         },
     ],
diff --git a/tests/ui/thir-print/thir-flat.stdout b/tests/ui/thir-print/thir-flat.stdout
index a31d08adab6..59cecfe511c 100644
--- a/tests/ui/thir-print/thir-flat.stdout
+++ b/tests/ui/thir-print/thir-flat.stdout
@@ -20,9 +20,12 @@ Thir {
                 block: b0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(2),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(2),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat.rs:4:15: 4:17 (#0),
         },
         Expr {
@@ -34,9 +37,12 @@ Thir {
                 value: e0,
             },
             ty: (),
-            temp_lifetime: Some(
-                Node(2),
-            ),
+            temp_lifetime: TempLifetime {
+                temp_lifetime: Some(
+                    Node(2),
+                ),
+                backwards_incompatible: None,
+            },
             span: $DIR/thir-flat.rs:4:15: 4:17 (#0),
         },
     ],
diff --git a/tests/ui/thir-print/thir-tree-match.stdout b/tests/ui/thir-print/thir-tree-match.stdout
index 8cff7887661..a9d6985928a 100644
--- a/tests/ui/thir-print/thir-tree-match.stdout
+++ b/tests/ui/thir-print/thir-tree-match.stdout
@@ -26,7 +26,7 @@ params: [
 body:
     Expr {
         ty: bool
-        temp_lifetime: Some(Node(26))
+        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(26)), backwards_incompatible: None }
         span: $DIR/thir-tree-match.rs:15:32: 21:2 (#0)
         kind: 
             Scope {
@@ -35,7 +35,7 @@ body:
                 value:
                     Expr {
                         ty: bool
-                        temp_lifetime: Some(Node(26))
+                        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(26)), backwards_incompatible: None }
                         span: $DIR/thir-tree-match.rs:15:32: 21:2 (#0)
                         kind: 
                             Block {
@@ -47,7 +47,7 @@ body:
                                 expr:
                                     Expr {
                                         ty: bool
-                                        temp_lifetime: Some(Node(26))
+                                        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(26)), backwards_incompatible: None }
                                         span: $DIR/thir-tree-match.rs:16:5: 20:6 (#0)
                                         kind: 
                                             Scope {
@@ -56,14 +56,14 @@ body:
                                                 value:
                                                     Expr {
                                                         ty: bool
-                                                        temp_lifetime: Some(Node(26))
+                                                        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(26)), backwards_incompatible: None }
                                                         span: $DIR/thir-tree-match.rs:16:5: 20:6 (#0)
                                                         kind: 
                                                             Match {
                                                                 scrutinee:
                                                                     Expr {
                                                                         ty: Foo
-                                                                        temp_lifetime: Some(Node(26))
+                                                                        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(26)), backwards_incompatible: None }
                                                                         span: $DIR/thir-tree-match.rs:16:11: 16:14 (#0)
                                                                         kind: 
                                                                             Scope {
@@ -72,7 +72,7 @@ body:
                                                                                 value:
                                                                                     Expr {
                                                                                         ty: Foo
-                                                                                        temp_lifetime: Some(Node(26))
+                                                                                        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(26)), backwards_incompatible: None }
                                                                                         span: $DIR/thir-tree-match.rs:16:11: 16:14 (#0)
                                                                                         kind: 
                                                                                             VarRef {
@@ -123,7 +123,7 @@ body:
                                                                         body: 
                                                                             Expr {
                                                                                 ty: bool
-                                                                                temp_lifetime: Some(Node(13))
+                                                                                temp_lifetime: TempLifetime { temp_lifetime: Some(Node(13)), backwards_incompatible: None }
                                                                                 span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0)
                                                                                 kind: 
                                                                                     Scope {
@@ -132,7 +132,7 @@ body:
                                                                                         value:
                                                                                             Expr {
                                                                                                 ty: bool
-                                                                                                temp_lifetime: Some(Node(13))
+                                                                                                temp_lifetime: TempLifetime { temp_lifetime: Some(Node(13)), backwards_incompatible: None }
                                                                                                 span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0)
                                                                                                 kind: 
                                                                                                     Literal( lit: Spanned { node: Bool(true), span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0) }, neg: false)
@@ -175,7 +175,7 @@ body:
                                                                         body: 
                                                                             Expr {
                                                                                 ty: bool
-                                                                                temp_lifetime: Some(Node(19))
+                                                                                temp_lifetime: TempLifetime { temp_lifetime: Some(Node(19)), backwards_incompatible: None }
                                                                                 span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0)
                                                                                 kind: 
                                                                                     Scope {
@@ -184,7 +184,7 @@ body:
                                                                                         value:
                                                                                             Expr {
                                                                                                 ty: bool
-                                                                                                temp_lifetime: Some(Node(19))
+                                                                                                temp_lifetime: TempLifetime { temp_lifetime: Some(Node(19)), backwards_incompatible: None }
                                                                                                 span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0)
                                                                                                 kind: 
                                                                                                     Literal( lit: Spanned { node: Bool(false), span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0) }, neg: false)
@@ -219,7 +219,7 @@ body:
                                                                         body: 
                                                                             Expr {
                                                                                 ty: bool
-                                                                                temp_lifetime: Some(Node(24))
+                                                                                temp_lifetime: TempLifetime { temp_lifetime: Some(Node(24)), backwards_incompatible: None }
                                                                                 span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0)
                                                                                 kind: 
                                                                                     Scope {
@@ -228,7 +228,7 @@ body:
                                                                                         value:
                                                                                             Expr {
                                                                                                 ty: bool
-                                                                                                temp_lifetime: Some(Node(24))
+                                                                                                temp_lifetime: TempLifetime { temp_lifetime: Some(Node(24)), backwards_incompatible: None }
                                                                                                 span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0)
                                                                                                 kind: 
                                                                                                     Literal( lit: Spanned { node: Bool(true), span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0) }, neg: false)
@@ -257,7 +257,7 @@ params: [
 body:
     Expr {
         ty: ()
-        temp_lifetime: Some(Node(2))
+        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(2)), backwards_incompatible: None }
         span: $DIR/thir-tree-match.rs:23:11: 23:13 (#0)
         kind: 
             Scope {
@@ -266,7 +266,7 @@ body:
                 value:
                     Expr {
                         ty: ()
-                        temp_lifetime: Some(Node(2))
+                        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(2)), backwards_incompatible: None }
                         span: $DIR/thir-tree-match.rs:23:11: 23:13 (#0)
                         kind: 
                             Block {
diff --git a/tests/ui/thir-print/thir-tree.stdout b/tests/ui/thir-print/thir-tree.stdout
index ef6db368dbe..b39581ad841 100644
--- a/tests/ui/thir-print/thir-tree.stdout
+++ b/tests/ui/thir-print/thir-tree.stdout
@@ -4,7 +4,7 @@ params: [
 body:
     Expr {
         ty: ()
-        temp_lifetime: Some(Node(2))
+        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(2)), backwards_incompatible: None }
         span: $DIR/thir-tree.rs:4:15: 4:17 (#0)
         kind: 
             Scope {
@@ -13,7 +13,7 @@ body:
                 value:
                     Expr {
                         ty: ()
-                        temp_lifetime: Some(Node(2))
+                        temp_lifetime: TempLifetime { temp_lifetime: Some(Node(2)), backwards_incompatible: None }
                         span: $DIR/thir-tree.rs:4:15: 4:17 (#0)
                         kind: 
                             Block {
diff --git a/tests/ui/traits/const-traits/const-fns-are-early-bound.rs b/tests/ui/traits/const-traits/const-fns-are-early-bound.rs
deleted file mode 100644
index c26eaf67454..00000000000
--- a/tests/ui/traits/const-traits/const-fns-are-early-bound.rs
+++ /dev/null
@@ -1,90 +0,0 @@
-//@ known-bug: #110395
-//@ failure-status: 101
-//@ dont-check-compiler-stderr
-// FIXME(const_trait_impl) check-pass
-//@ compile-flags: -Znext-solver
-
-#![crate_type = "lib"]
-#![allow(internal_features, incomplete_features)]
-#![no_std]
-#![no_core]
-#![feature(
-    auto_traits,
-    const_trait_impl,
-    effects,
-    lang_items,
-    no_core,
-    staged_api,
-    unboxed_closures,
-    rustc_attrs,
-    marker_trait_attr,
-)]
-#![stable(feature = "minicore", since = "1.0.0")]
-
-fn test() {
-    fn is_const_fn<F>(_: F)
-    where
-        F: const FnOnce<()>,
-    {
-    }
-
-    const fn foo() {}
-
-    is_const_fn(foo);
-}
-
-/// ---------------------------------------------------------------------- ///
-/// Const fn trait definitions
-
-#[const_trait]
-#[lang = "fn"]
-#[rustc_paren_sugar]
-trait Fn<Args: Tuple>: ~const FnMut<Args> {
-    extern "rust-call" fn call(&self, args: Args) -> Self::Output;
-}
-
-#[const_trait]
-#[lang = "fn_mut"]
-#[rustc_paren_sugar]
-trait FnMut<Args: Tuple>: ~const FnOnce<Args> {
-    extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output;
-}
-
-#[const_trait]
-#[lang = "fn_once"]
-#[rustc_paren_sugar]
-trait FnOnce<Args: Tuple> {
-    #[lang = "fn_once_output"]
-    type Output;
-
-    extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
-}
-
-/// ---------------------------------------------------------------------- ///
-/// All this other stuff needed for core. Unrelated to test.
-
-#[lang = "destruct"]
-#[const_trait]
-trait Destruct {}
-
-#[lang = "freeze"]
-unsafe auto trait Freeze {}
-
-#[lang = "drop"]
-#[const_trait]
-trait Drop {
-    fn drop(&mut self);
-}
-
-#[lang = "sized"]
-trait Sized {}
-#[lang = "copy"]
-trait Copy {}
-
-#[lang = "tuple_trait"]
-trait Tuple {}
-
-#[lang = "legacy_receiver"]
-trait LegacyReceiver {}
-
-impl<T: ?Sized> LegacyReceiver for &T {}
diff --git a/tests/ui/traits/const-traits/effects/minicore-const-fn-early-bound.rs b/tests/ui/traits/const-traits/effects/minicore-const-fn-early-bound.rs
new file mode 100644
index 00000000000..ee47f92a0bc
--- /dev/null
+++ b/tests/ui/traits/const-traits/effects/minicore-const-fn-early-bound.rs
@@ -0,0 +1,22 @@
+//@ aux-build:minicore.rs
+//@ compile-flags: --crate-type=lib -Znext-solver -Cpanic=abort
+//@ check-pass
+
+#![feature(no_core, const_trait_impl)]
+#![no_std]
+#![no_core]
+
+extern crate minicore;
+use minicore::*;
+
+fn is_const_fn<F>(_: F)
+where
+    F: const FnOnce(),
+{
+}
+
+const fn foo() {}
+
+fn test() {
+    is_const_fn(foo);
+}
diff --git a/tests/ui/traits/const-traits/effects/minicore-fn-fail.rs b/tests/ui/traits/const-traits/effects/minicore-fn-fail.rs
new file mode 100644
index 00000000000..ae1cbc6ca58
--- /dev/null
+++ b/tests/ui/traits/const-traits/effects/minicore-fn-fail.rs
@@ -0,0 +1,21 @@
+//@ aux-build:minicore.rs
+//@ compile-flags: --crate-type=lib -Znext-solver
+
+#![feature(no_core, const_trait_impl)]
+#![no_std]
+#![no_core]
+
+extern crate minicore;
+use minicore::*;
+
+const fn call_indirect<T: ~const Fn()>(t: &T) { t() }
+
+#[const_trait]
+trait Foo {}
+impl Foo for () {}
+const fn foo<T: ~const Foo>() {}
+
+const fn test() {
+    call_indirect(&foo::<()>);
+    //~^ ERROR the trait bound `(): ~const Foo` is not satisfied
+}
diff --git a/tests/ui/traits/const-traits/effects/minicore-fn-fail.stderr b/tests/ui/traits/const-traits/effects/minicore-fn-fail.stderr
new file mode 100644
index 00000000000..cf158643b34
--- /dev/null
+++ b/tests/ui/traits/const-traits/effects/minicore-fn-fail.stderr
@@ -0,0 +1,9 @@
+error[E0277]: the trait bound `(): ~const Foo` is not satisfied
+  --> $DIR/minicore-fn-fail.rs:19:5
+   |
+LL |     call_indirect(&foo::<()>);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/traits/const-traits/effects/minicore-works.rs b/tests/ui/traits/const-traits/effects/minicore-works.rs
index bfbfa8b2d05..c79b4fc07df 100644
--- a/tests/ui/traits/const-traits/effects/minicore-works.rs
+++ b/tests/ui/traits/const-traits/effects/minicore-works.rs
@@ -20,3 +20,9 @@ const fn test_op() {
     let _x = Add::add(1, 2);
     let _y = Custom + Custom;
 }
+
+const fn call_indirect<T: ~const Fn()>(t: &T) { t() }
+
+const fn call() {
+    call_indirect(&call);
+}