diff --git a/compiler/rustc_mir/src/borrow_check/diagnostics/conflict_errors.rs b/compiler/rustc_mir/src/borrow_check/diagnostics/conflict_errors.rs
index 11122b195c0..dca0d6d7790 100644
--- a/compiler/rustc_mir/src/borrow_check/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_mir/src/borrow_check/diagnostics/conflict_errors.rs
@@ -336,10 +336,11 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 };
                 if let ty::Param(param_ty) = ty.kind() {
                     let tcx = self.infcx.tcx;
-                    let generics = tcx.generics_of(self.mir_def_id);
+                    let generics = tcx.generics_of(self.mir_def_id());
                     let param = generics.type_param(&param_ty, tcx);
-                    if let Some(generics) =
-                        tcx.hir().get_generics(tcx.closure_base_def_id(self.mir_def_id.to_def_id()))
+                    if let Some(generics) = tcx
+                        .hir()
+                        .get_generics(tcx.closure_base_def_id(self.mir_def_id().to_def_id()))
                     {
                         suggest_constraining_type_param(
                             tcx,
@@ -1004,7 +1005,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 format!("`{}` would have to be valid for `{}`...", name, region_name),
             );
 
-            let fn_hir_id = self.infcx.tcx.hir().local_def_id_to_hir_id(self.mir_def_id);
+            let fn_hir_id = self.mir_hir_id();
             err.span_label(
                 drop_span,
                 format!(
@@ -1019,7 +1020,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             match &self
                                 .infcx
                                 .tcx
-                                .typeck(self.mir_def_id)
+                                .typeck(self.mir_def_id())
                                 .node_type(fn_hir_id)
                                 .kind()
                             {
@@ -1369,7 +1370,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
     ) -> DiagnosticBuilder<'cx> {
         let tcx = self.infcx.tcx;
 
-        let (_, escapes_from) = tcx.article_and_description(self.mir_def_id.to_def_id());
+        let (_, escapes_from) = tcx.article_and_description(self.mir_def_id().to_def_id());
 
         let mut err =
             borrowck_errors::borrowed_data_escapes_closure(tcx, escape_span, escapes_from);
@@ -1708,15 +1709,15 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
     ) -> Option<AnnotatedBorrowFnSignature<'tcx>> {
         // Define a fallback for when we can't match a closure.
         let fallback = || {
-            let is_closure = self.infcx.tcx.is_closure(self.mir_def_id.to_def_id());
+            let is_closure = self.infcx.tcx.is_closure(self.mir_def_id().to_def_id());
             if is_closure {
                 None
             } else {
-                let ty = self.infcx.tcx.type_of(self.mir_def_id);
+                let ty = self.infcx.tcx.type_of(self.mir_def_id());
                 match ty.kind() {
                     ty::FnDef(_, _) | ty::FnPtr(_) => self.annotate_fn_sig(
-                        self.mir_def_id.to_def_id(),
-                        self.infcx.tcx.fn_sig(self.mir_def_id),
+                        self.mir_def_id().to_def_id(),
+                        self.infcx.tcx.fn_sig(self.mir_def_id()),
                     ),
                     _ => None,
                 }
diff --git a/compiler/rustc_mir/src/borrow_check/diagnostics/move_errors.rs b/compiler/rustc_mir/src/borrow_check/diagnostics/move_errors.rs
index 629e9be9ddd..b1cebbd1f38 100644
--- a/compiler/rustc_mir/src/borrow_check/diagnostics/move_errors.rs
+++ b/compiler/rustc_mir/src/borrow_check/diagnostics/move_errors.rs
@@ -331,7 +331,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 self.cannot_move_out_of_interior_noncopy(span, ty, None)
             }
             ty::Closure(def_id, closure_substs)
-                if def_id.as_local() == Some(self.mir_def_id) && upvar_field.is_some() =>
+                if def_id.as_local() == Some(self.mir_def_id()) && upvar_field.is_some() =>
             {
                 let closure_kind_ty = closure_substs.as_closure().kind_ty();
                 let closure_kind = closure_kind_ty.to_opt_closure_kind();
diff --git a/compiler/rustc_mir/src/borrow_check/diagnostics/mutability_errors.rs b/compiler/rustc_mir/src/borrow_check/diagnostics/mutability_errors.rs
index d4cdf02104a..9728662c984 100644
--- a/compiler/rustc_mir/src/borrow_check/diagnostics/mutability_errors.rs
+++ b/compiler/rustc_mir/src/borrow_check/diagnostics/mutability_errors.rs
@@ -492,7 +492,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         err.span_label(sp, format!("cannot {}", act));
 
         let hir = self.infcx.tcx.hir();
-        let closure_id = hir.local_def_id_to_hir_id(self.mir_def_id);
+        let closure_id = self.mir_hir_id();
         let fn_call_id = hir.get_parent_node(closure_id);
         let node = hir.get(fn_call_id);
         let item_id = hir.enclosing_body_owner(fn_call_id);
diff --git a/compiler/rustc_mir/src/borrow_check/diagnostics/region_errors.rs b/compiler/rustc_mir/src/borrow_check/diagnostics/region_errors.rs
index eb1f70099fc..b145e1d5fa3 100644
--- a/compiler/rustc_mir/src/borrow_check/diagnostics/region_errors.rs
+++ b/compiler/rustc_mir/src/borrow_check/diagnostics/region_errors.rs
@@ -515,7 +515,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         let mut diag =
             self.infcx.tcx.sess.struct_span_err(*span, "lifetime may not live long enough");
 
-        let (_, mir_def_name) = self.infcx.tcx.article_and_description(self.mir_def_id.to_def_id());
+        let (_, mir_def_name) =
+            self.infcx.tcx.article_and_description(self.mir_def_id().to_def_id());
 
         let fr_name = self.give_region_a_name(*fr).unwrap();
         fr_name.highlight_region_name(&mut diag);
diff --git a/compiler/rustc_mir/src/borrow_check/diagnostics/region_name.rs b/compiler/rustc_mir/src/borrow_check/diagnostics/region_name.rs
index 5f64eb3dba8..2e5a231fef0 100644
--- a/compiler/rustc_mir/src/borrow_check/diagnostics/region_name.rs
+++ b/compiler/rustc_mir/src/borrow_check/diagnostics/region_name.rs
@@ -147,6 +147,14 @@ impl Display for RegionName {
 }
 
 impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
+    crate fn mir_def_id(&self) -> hir::def_id::LocalDefId {
+        self.body.source.def_id().as_local().unwrap()
+    }
+
+    crate fn mir_hir_id(&self) -> hir::HirId {
+        self.infcx.tcx.hir().local_def_id_to_hir_id(self.mir_def_id())
+    }
+
     /// Generate a synthetic region named `'N`, where `N` is the next value of the counter. Then,
     /// increment the counter.
     ///
@@ -266,12 +274,11 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
                 }
 
                 ty::BoundRegion::BrEnv => {
-                    let mir_hir_id = self.infcx.tcx.hir().local_def_id_to_hir_id(self.mir_def_id);
                     let def_ty = self.regioncx.universal_regions().defining_ty;
 
                     if let DefiningTy::Closure(_, substs) = def_ty {
                         let args_span = if let hir::ExprKind::Closure(_, _, _, span, _) =
-                            tcx.hir().expect_expr(mir_hir_id).kind
+                            tcx.hir().expect_expr(self.mir_hir_id()).kind
                         {
                             span
                         } else {
@@ -361,8 +368,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
         &self,
         argument_index: usize,
     ) -> Option<&hir::Ty<'tcx>> {
-        let mir_hir_id = self.infcx.tcx.hir().local_def_id_to_hir_id(self.mir_def_id);
-        let fn_decl = self.infcx.tcx.hir().fn_decl_by_hir_id(mir_hir_id)?;
+        let fn_decl = self.infcx.tcx.hir().fn_decl_by_hir_id(self.mir_hir_id())?;
         let argument_hir_ty: &hir::Ty<'_> = fn_decl.inputs.get(argument_index)?;
         match argument_hir_ty.kind {
             // This indicates a variable with no type annotation, like
@@ -649,9 +655,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
         let type_name =
             self.infcx.extract_inference_diagnostics_data(return_ty.into(), Some(highlight)).name;
 
-        let mir_hir_id = tcx.hir().local_def_id_to_hir_id(self.mir_def_id);
-
-        let (return_span, mir_description) = match tcx.hir().get(mir_hir_id) {
+        let (return_span, mir_description) = match tcx.hir().get(self.mir_hir_id()) {
             hir::Node::Expr(hir::Expr {
                 kind: hir::ExprKind::Closure(_, return_ty, _, span, gen_move),
                 ..
@@ -702,9 +706,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
         let type_name =
             self.infcx.extract_inference_diagnostics_data(yield_ty.into(), Some(highlight)).name;
 
-        let mir_hir_id = tcx.hir().local_def_id_to_hir_id(self.mir_def_id);
-
-        let yield_span = match tcx.hir().get(mir_hir_id) {
+        let yield_span = match tcx.hir().get(self.mir_hir_id()) {
             hir::Node::Expr(hir::Expr {
                 kind: hir::ExprKind::Closure(_, _, _, span, _), ..
             }) => (tcx.sess.source_map().end_point(*span)),
diff --git a/compiler/rustc_mir/src/borrow_check/mod.rs b/compiler/rustc_mir/src/borrow_check/mod.rs
index 37e2730025d..9b34db1de40 100644
--- a/compiler/rustc_mir/src/borrow_check/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/mod.rs
@@ -111,7 +111,7 @@ fn mir_borrowck<'tcx>(
     let opt_closure_req = tcx.infer_ctxt().enter(|infcx| {
         let input_body: &Body<'_> = &input_body.borrow();
         let promoted: &IndexVec<_, _> = &promoted.borrow();
-        do_mir_borrowck(&infcx, input_body, promoted, def)
+        do_mir_borrowck(&infcx, input_body, promoted)
     });
     debug!("mir_borrowck done");
 
@@ -122,8 +122,9 @@ fn do_mir_borrowck<'a, 'tcx>(
     infcx: &InferCtxt<'a, 'tcx>,
     input_body: &Body<'tcx>,
     input_promoted: &IndexVec<Promoted, Body<'tcx>>,
-    def: ty::WithOptConstParam<LocalDefId>,
 ) -> BorrowCheckResult<'tcx> {
+    let def = input_body.source.with_opt_param().as_local().unwrap();
+
     debug!("do_mir_borrowck(def = {:?})", def);
 
     let tcx = infcx.tcx;
@@ -185,7 +186,7 @@ fn do_mir_borrowck<'a, 'tcx>(
     // will have a lifetime tied to the inference context.
     let mut body = input_body.clone();
     let mut promoted = input_promoted.clone();
-    let free_regions = nll::replace_regions_in_mir(infcx, def, param_env, &mut body, &mut promoted);
+    let free_regions = nll::replace_regions_in_mir(infcx, param_env, &mut body, &mut promoted);
     let body = &body; // no further changes
 
     let location_table = &LocationTable::new(&body);
@@ -203,7 +204,7 @@ fn do_mir_borrowck<'a, 'tcx>(
     let mdpe = MoveDataParamEnv { move_data, param_env };
 
     let mut flow_inits = MaybeInitializedPlaces::new(tcx, &body, &mdpe)
-        .into_engine(tcx, &body, def.did.to_def_id())
+        .into_engine(tcx, &body)
         .pass_name("borrowck")
         .iterate_to_fixpoint()
         .into_results_cursor(&body);
@@ -221,7 +222,6 @@ fn do_mir_borrowck<'a, 'tcx>(
         nll_errors,
     } = nll::compute_regions(
         infcx,
-        def.did,
         free_regions,
         body,
         &promoted,
@@ -242,7 +242,6 @@ fn do_mir_borrowck<'a, 'tcx>(
     nll::dump_annotation(
         infcx,
         &body,
-        def.did.to_def_id(),
         &regioncx,
         &opt_closure_req,
         &opaque_type_values,
@@ -257,15 +256,15 @@ fn do_mir_borrowck<'a, 'tcx>(
     let regioncx = Rc::new(regioncx);
 
     let flow_borrows = Borrows::new(tcx, &body, regioncx.clone(), &borrow_set)
-        .into_engine(tcx, &body, def.did.to_def_id())
+        .into_engine(tcx, &body)
         .pass_name("borrowck")
         .iterate_to_fixpoint();
     let flow_uninits = MaybeUninitializedPlaces::new(tcx, &body, &mdpe)
-        .into_engine(tcx, &body, def.did.to_def_id())
+        .into_engine(tcx, &body)
         .pass_name("borrowck")
         .iterate_to_fixpoint();
     let flow_ever_inits = EverInitializedPlaces::new(tcx, &body, &mdpe)
-        .into_engine(tcx, &body, def.did.to_def_id())
+        .into_engine(tcx, &body)
         .pass_name("borrowck")
         .iterate_to_fixpoint();
 
@@ -286,7 +285,6 @@ fn do_mir_borrowck<'a, 'tcx>(
                 infcx,
                 param_env,
                 body: promoted_body,
-                mir_def_id: def.did,
                 move_data: &move_data,
                 location_table: &LocationTable::new(promoted_body),
                 movable_generator,
@@ -320,7 +318,6 @@ fn do_mir_borrowck<'a, 'tcx>(
         infcx,
         param_env,
         body,
-        mir_def_id: def.did,
         move_data: &mdpe.move_data,
         location_table,
         movable_generator,
@@ -474,7 +471,6 @@ crate struct MirBorrowckCtxt<'cx, 'tcx> {
     crate infcx: &'cx InferCtxt<'cx, 'tcx>,
     param_env: ParamEnv<'tcx>,
     body: &'cx Body<'tcx>,
-    mir_def_id: LocalDefId,
     move_data: &'cx MoveData<'tcx>,
 
     /// Map from MIR `Location` to `LocationIndex`; created
diff --git a/compiler/rustc_mir/src/borrow_check/nll.rs b/compiler/rustc_mir/src/borrow_check/nll.rs
index 44125885f2a..aa428328fe9 100644
--- a/compiler/rustc_mir/src/borrow_check/nll.rs
+++ b/compiler/rustc_mir/src/borrow_check/nll.rs
@@ -2,7 +2,7 @@
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::Diagnostic;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::DefId;
 use rustc_index::vec::IndexVec;
 use rustc_infer::infer::InferCtxt;
 use rustc_middle::mir::{
@@ -58,11 +58,12 @@ crate struct NllOutput<'tcx> {
 /// `compute_regions`.
 pub(in crate::borrow_check) fn replace_regions_in_mir<'cx, 'tcx>(
     infcx: &InferCtxt<'cx, 'tcx>,
-    def: ty::WithOptConstParam<LocalDefId>,
     param_env: ty::ParamEnv<'tcx>,
     body: &mut Body<'tcx>,
     promoted: &mut IndexVec<Promoted, Body<'tcx>>,
 ) -> UniversalRegions<'tcx> {
+    let def = body.source.with_opt_param().as_local().unwrap();
+
     debug!("replace_regions_in_mir(def={:?})", def);
 
     // Compute named region information. This also renumbers the inputs/outputs.
@@ -156,7 +157,6 @@ fn populate_polonius_move_facts(
 /// This may result in errors being reported.
 pub(in crate::borrow_check) fn compute_regions<'cx, 'tcx>(
     infcx: &InferCtxt<'cx, 'tcx>,
-    def_id: LocalDefId,
     universal_regions: UniversalRegions<'tcx>,
     body: &Body<'tcx>,
     promoted: &IndexVec<Promoted, Body<'tcx>>,
@@ -180,7 +180,6 @@ pub(in crate::borrow_check) fn compute_regions<'cx, 'tcx>(
             param_env,
             body,
             promoted,
-            def_id,
             &universal_regions,
             location_table,
             borrow_set,
@@ -270,10 +269,12 @@ pub(in crate::borrow_check) fn compute_regions<'cx, 'tcx>(
     // Generate various additional constraints.
     invalidation::generate_invalidates(infcx.tcx, &mut all_facts, location_table, body, borrow_set);
 
+    let def_id = body.source.def_id();
+
     // Dump facts if requested.
     let polonius_output = all_facts.and_then(|all_facts| {
         if infcx.tcx.sess.opts.debugging_opts.nll_facts {
-            let def_path = infcx.tcx.def_path(def_id.to_def_id());
+            let def_path = infcx.tcx.def_path(def_id);
             let dir_path =
                 PathBuf::from("nll-facts").join(def_path.to_filename_friendly_no_crate());
             all_facts.write_to_dir(dir_path, location_table).unwrap();
@@ -293,7 +294,7 @@ pub(in crate::borrow_check) fn compute_regions<'cx, 'tcx>(
 
     // Solve the region constraints.
     let (closure_region_requirements, nll_errors) =
-        regioncx.solve(infcx, &body, def_id.to_def_id(), polonius_output.clone());
+        regioncx.solve(infcx, &body, polonius_output.clone());
 
     if !nll_errors.is_empty() {
         // Suppress unhelpful extra errors in `infer_opaque_types`.
@@ -364,14 +365,13 @@ pub(super) fn dump_mir_results<'a, 'tcx>(
 pub(super) fn dump_annotation<'a, 'tcx>(
     infcx: &InferCtxt<'a, 'tcx>,
     body: &Body<'tcx>,
-    mir_def_id: DefId,
     regioncx: &RegionInferenceContext<'tcx>,
     closure_region_requirements: &Option<ClosureRegionRequirements<'_>>,
     opaque_type_values: &FxHashMap<DefId, ty::ResolvedOpaqueTy<'tcx>>,
     errors_buffer: &mut Vec<Diagnostic>,
 ) {
     let tcx = infcx.tcx;
-    let base_def_id = tcx.closure_base_def_id(mir_def_id);
+    let base_def_id = tcx.closure_base_def_id(body.source.def_id());
     if !tcx.has_attr(base_def_id, sym::rustc_regions) {
         return;
     }
diff --git a/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs b/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs
index 3dc082a4413..5492e328535 100644
--- a/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs
@@ -548,9 +548,9 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         &mut self,
         infcx: &InferCtxt<'_, 'tcx>,
         body: &Body<'tcx>,
-        mir_def_id: DefId,
         polonius_output: Option<Rc<PoloniusOutput>>,
     ) -> (Option<ClosureRegionRequirements<'tcx>>, RegionErrors<'tcx>) {
+        let mir_def_id = body.source.def_id();
         self.propagate_constraints(body, infcx.tcx);
 
         let mut errors_buffer = RegionErrors::new();
diff --git a/compiler/rustc_mir/src/borrow_check/type_check/input_output.rs b/compiler/rustc_mir/src/borrow_check/type_check/input_output.rs
index 4846ef06a8b..3c8cbeeca38 100644
--- a/compiler/rustc_mir/src/borrow_check/type_check/input_output.rs
+++ b/compiler/rustc_mir/src/borrow_check/type_check/input_output.rs
@@ -28,42 +28,43 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         let (&normalized_output_ty, normalized_input_tys) =
             normalized_inputs_and_output.split_last().unwrap();
 
+        let mir_def_id = body.source.def_id().expect_local();
+
         // If the user explicitly annotated the input types, extract
         // those.
         //
         // e.g., `|x: FxHashMap<_, &'static u32>| ...`
         let user_provided_sig;
-        if !self.tcx().is_closure(self.mir_def_id.to_def_id()) {
+        if !self.tcx().is_closure(mir_def_id.to_def_id()) {
             user_provided_sig = None;
         } else {
-            let typeck_results = self.tcx().typeck(self.mir_def_id);
-            user_provided_sig =
-                match typeck_results.user_provided_sigs.get(&self.mir_def_id.to_def_id()) {
-                    None => None,
-                    Some(user_provided_poly_sig) => {
-                        // Instantiate the canonicalized variables from
-                        // user-provided signature (e.g., the `_` in the code
-                        // above) with fresh variables.
-                        let (poly_sig, _) =
-                            self.infcx.instantiate_canonical_with_fresh_inference_vars(
-                                body.span,
-                                &user_provided_poly_sig,
-                            );
+            let typeck_results = self.tcx().typeck(mir_def_id);
+            user_provided_sig = match typeck_results.user_provided_sigs.get(&mir_def_id.to_def_id())
+            {
+                None => None,
+                Some(user_provided_poly_sig) => {
+                    // Instantiate the canonicalized variables from
+                    // user-provided signature (e.g., the `_` in the code
+                    // above) with fresh variables.
+                    let (poly_sig, _) = self.infcx.instantiate_canonical_with_fresh_inference_vars(
+                        body.span,
+                        &user_provided_poly_sig,
+                    );
 
-                        // Replace the bound items in the fn sig with fresh
-                        // variables, so that they represent the view from
-                        // "inside" the closure.
-                        Some(
-                            self.infcx
-                                .replace_bound_vars_with_fresh_vars(
-                                    body.span,
-                                    LateBoundRegionConversionTime::FnCall,
-                                    &poly_sig,
-                                )
-                                .0,
-                        )
-                    }
+                    // Replace the bound items in the fn sig with fresh
+                    // variables, so that they represent the view from
+                    // "inside" the closure.
+                    Some(
+                        self.infcx
+                            .replace_bound_vars_with_fresh_vars(
+                                body.span,
+                                LateBoundRegionConversionTime::FnCall,
+                                &poly_sig,
+                            )
+                            .0,
+                    )
                 }
+            }
         };
 
         debug!(
@@ -122,7 +123,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         if let Err(terr) = self.eq_opaque_type_and_type(
             mir_output_ty,
             normalized_output_ty,
-            self.mir_def_id,
+            mir_def_id,
             Locations::All(output_span),
             ConstraintCategory::BoringNoLocation,
         ) {
@@ -145,7 +146,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             if let Err(err) = self.eq_opaque_type_and_type(
                 mir_output_ty,
                 user_provided_output_ty,
-                self.mir_def_id,
+                mir_def_id,
                 Locations::All(output_span),
                 ConstraintCategory::BoringNoLocation,
             ) {
diff --git a/compiler/rustc_mir/src/borrow_check/type_check/mod.rs b/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
index 3ace14610e2..f8a8801595a 100644
--- a/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
@@ -73,7 +73,7 @@ macro_rules! span_mirbug {
             $context.last_span,
             &format!(
                 "broken MIR in {:?} ({:?}): {}",
-                $context.mir_def_id,
+                $context.body.source.def_id(),
                 $elem,
                 format_args!($($message)*),
             ),
@@ -113,7 +113,6 @@ mod relate_tys;
 /// - `param_env` -- parameter environment to use for trait solving
 /// - `body` -- MIR body to type-check
 /// - `promoted` -- map of promoted constants within `body`
-/// - `mir_def_id` -- `LocalDefId` from which the MIR is derived
 /// - `universal_regions` -- the universal regions from `body`s function signature
 /// - `location_table` -- MIR location map of `body`
 /// - `borrow_set` -- information about borrows occurring in `body`
@@ -126,7 +125,6 @@ pub(crate) fn type_check<'mir, 'tcx>(
     param_env: ty::ParamEnv<'tcx>,
     body: &Body<'tcx>,
     promoted: &IndexVec<Promoted, Body<'tcx>>,
-    mir_def_id: LocalDefId,
     universal_regions: &Rc<UniversalRegions<'tcx>>,
     location_table: &LocationTable,
     borrow_set: &BorrowSet<'tcx>,
@@ -170,7 +168,6 @@ pub(crate) fn type_check<'mir, 'tcx>(
 
     let opaque_type_values = type_check_internal(
         infcx,
-        mir_def_id,
         param_env,
         body,
         promoted,
@@ -192,7 +189,6 @@ pub(crate) fn type_check<'mir, 'tcx>(
 
 fn type_check_internal<'a, 'tcx, R>(
     infcx: &'a InferCtxt<'a, 'tcx>,
-    mir_def_id: LocalDefId,
     param_env: ty::ParamEnv<'tcx>,
     body: &'a Body<'tcx>,
     promoted: &'a IndexVec<Promoted, Body<'tcx>>,
@@ -205,7 +201,6 @@ fn type_check_internal<'a, 'tcx, R>(
     let mut checker = TypeChecker::new(
         infcx,
         body,
-        mir_def_id,
         param_env,
         region_bound_pairs,
         implicit_region_bound,
@@ -272,7 +267,6 @@ struct TypeVerifier<'a, 'b, 'tcx> {
     body: &'b Body<'tcx>,
     promoted: &'b IndexVec<Promoted, Body<'tcx>>,
     last_span: Span,
-    mir_def_id: LocalDefId,
     errors_reported: bool,
 }
 
@@ -460,14 +454,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
         body: &'b Body<'tcx>,
         promoted: &'b IndexVec<Promoted, Body<'tcx>>,
     ) -> Self {
-        TypeVerifier {
-            body,
-            promoted,
-            mir_def_id: cx.mir_def_id,
-            cx,
-            last_span: body.span,
-            errors_reported: false,
-        }
+        TypeVerifier { body, promoted, cx, last_span: body.span, errors_reported: false }
     }
 
     fn tcx(&self) -> TyCtxt<'tcx> {
@@ -816,7 +803,6 @@ struct TypeChecker<'a, 'tcx> {
     /// User type annotations are shared between the main MIR and the MIR of
     /// all of the promoted items.
     user_type_annotations: &'a CanonicalUserTypeAnnotations<'tcx>,
-    mir_def_id: LocalDefId,
     region_bound_pairs: &'a RegionBoundPairs<'tcx>,
     implicit_region_bound: ty::Region<'tcx>,
     reported_errors: FxHashSet<(Ty<'tcx>, Span)>,
@@ -965,7 +951,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     fn new(
         infcx: &'a InferCtxt<'a, 'tcx>,
         body: &'a Body<'tcx>,
-        mir_def_id: LocalDefId,
         param_env: ty::ParamEnv<'tcx>,
         region_bound_pairs: &'a RegionBoundPairs<'tcx>,
         implicit_region_bound: ty::Region<'tcx>,
@@ -975,7 +960,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         let mut checker = Self {
             infcx,
             last_span: DUMMY_SP,
-            mir_def_id,
             body,
             user_type_annotations: &body.user_type_annotations,
             param_env,
@@ -1145,7 +1129,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 // the resulting inferend values are stored with the
                 // def-id of the base function.
                 let parent_def_id =
-                    self.tcx().closure_base_def_id(self.mir_def_id.to_def_id()).expect_local();
+                    self.tcx().closure_base_def_id(self.body.source.def_id()).expect_local();
                 return self.eq_opaque_type_and_type(sub, sup, parent_def_id, locations, category);
             } else {
                 return Err(terr);
@@ -1242,7 +1226,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         let concrete_opaque_types = &tcx.typeck(anon_owner_def_id).concrete_opaque_types;
         let mut opaque_type_values = Vec::new();
 
-        debug!("eq_opaque_type_and_type: mir_def_id={:?}", self.mir_def_id);
+        debug!("eq_opaque_type_and_type: mir_def_id={:?}", body.source.def_id());
         let opaque_type_map = self.fully_perform_op(
             locations,
             category,
@@ -2001,12 +1985,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                         let span = body.source_info(location).span;
                         let ty = operand.ty(body, tcx);
                         if !self.infcx.type_is_copy_modulo_regions(self.param_env, ty, span) {
-                            let ccx = ConstCx::new_with_param_env(
-                                tcx,
-                                self.mir_def_id,
-                                body,
-                                self.param_env,
-                            );
+                            let ccx = ConstCx::new_with_param_env(tcx, body, self.param_env);
                             // To determine if `const_in_array_repeat_expressions` feature gate should
                             // be mentioned, need to check if the rvalue is promotable.
                             let should_suggest =
@@ -2015,11 +1994,12 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                                 );
                             debug!("check_rvalue: should_suggest={:?}", should_suggest);
 
+                            let def_id = body.source.def_id().expect_local();
                             self.infcx.report_selection_error(
                                 &traits::Obligation::new(
                                     ObligationCause::new(
                                         span,
-                                        self.tcx().hir().local_def_id_to_hir_id(self.mir_def_id),
+                                        self.tcx().hir().local_def_id_to_hir_id(def_id),
                                         traits::ObligationCauseCode::RepeatVec(should_suggest),
                                     ),
                                     self.param_env,
diff --git a/compiler/rustc_mir/src/dataflow/framework/engine.rs b/compiler/rustc_mir/src/dataflow/framework/engine.rs
index f39c78f503d..b836e85c3a7 100644
--- a/compiler/rustc_mir/src/dataflow/framework/engine.rs
+++ b/compiler/rustc_mir/src/dataflow/framework/engine.rs
@@ -81,7 +81,6 @@ where
 {
     tcx: TyCtxt<'tcx>,
     body: &'a mir::Body<'tcx>,
-    def_id: DefId,
     dead_unwinds: Option<&'a BitSet<BasicBlock>>,
     entry_sets: IndexVec<BasicBlock, A::Domain>,
     pass_name: Option<&'static str>,
@@ -103,18 +102,13 @@ where
     T: Idx,
 {
     /// Creates a new `Engine` to solve a gen-kill dataflow problem.
-    pub fn new_gen_kill(
-        tcx: TyCtxt<'tcx>,
-        body: &'a mir::Body<'tcx>,
-        def_id: DefId,
-        analysis: A,
-    ) -> Self {
+    pub fn new_gen_kill(tcx: TyCtxt<'tcx>, body: &'a mir::Body<'tcx>, analysis: A) -> Self {
         // If there are no back-edges in the control-flow graph, we only ever need to apply the
         // transfer function for each block exactly once (assuming that we process blocks in RPO).
         //
         // In this case, there's no need to compute the block transfer functions ahead of time.
         if !body.is_cfg_cyclic() {
-            return Self::new(tcx, body, def_id, analysis, None);
+            return Self::new(tcx, body, analysis, None);
         }
 
         // Otherwise, compute and store the cumulative transfer function for each block.
@@ -131,7 +125,7 @@ where
             trans_for_block[bb].apply(state.borrow_mut());
         });
 
-        Self::new(tcx, body, def_id, analysis, Some(apply_trans as Box<_>))
+        Self::new(tcx, body, analysis, Some(apply_trans as Box<_>))
     }
 }
 
@@ -145,19 +139,13 @@ where
     ///
     /// Gen-kill problems should use `new_gen_kill`, which will coalesce transfer functions for
     /// better performance.
-    pub fn new_generic(
-        tcx: TyCtxt<'tcx>,
-        body: &'a mir::Body<'tcx>,
-        def_id: DefId,
-        analysis: A,
-    ) -> Self {
-        Self::new(tcx, body, def_id, analysis, None)
+    pub fn new_generic(tcx: TyCtxt<'tcx>, body: &'a mir::Body<'tcx>, analysis: A) -> Self {
+        Self::new(tcx, body, analysis, None)
     }
 
     fn new(
         tcx: TyCtxt<'tcx>,
         body: &'a mir::Body<'tcx>,
-        def_id: DefId,
         analysis: A,
         apply_trans_for_block: Option<Box<dyn Fn(BasicBlock, &mut A::Domain)>>,
     ) -> Self {
@@ -173,7 +161,6 @@ where
             analysis,
             tcx,
             body,
-            def_id,
             dead_unwinds: None,
             pass_name: None,
             entry_sets,
@@ -209,7 +196,6 @@ where
             analysis,
             body,
             dead_unwinds,
-            def_id,
             mut entry_sets,
             tcx,
             apply_trans_for_block,
@@ -261,7 +247,7 @@ where
 
         let results = Results { analysis, entry_sets };
 
-        let res = write_graphviz_results(tcx, def_id, &body, &results, pass_name);
+        let res = write_graphviz_results(tcx, &body, &results, pass_name);
         if let Err(e) = res {
             warn!("Failed to write graphviz dataflow results: {}", e);
         }
@@ -276,7 +262,6 @@ where
 /// `rustc_mir` attributes.
 fn write_graphviz_results<A>(
     tcx: TyCtxt<'tcx>,
-    def_id: DefId,
     body: &mir::Body<'tcx>,
     results: &Results<'tcx, A>,
     pass_name: Option<&'static str>,
@@ -285,6 +270,7 @@ where
     A: Analysis<'tcx>,
     A::Domain: DebugWithContext<A>,
 {
+    let def_id = body.source.def_id();
     let attrs = match RustcMirAttrs::parse(tcx, def_id) {
         Ok(attrs) => attrs,
 
@@ -323,7 +309,7 @@ where
     debug!("printing dataflow results for {:?} to {}", def_id, path.display());
     let mut buf = Vec::new();
 
-    let graphviz = graphviz::Formatter::new(body, def_id, results, style);
+    let graphviz = graphviz::Formatter::new(body, results, style);
     let mut render_opts =
         vec![dot::RenderOption::Fontname(tcx.sess.opts.debugging_opts.graphviz_font.clone())];
     if tcx.sess.opts.debugging_opts.graphviz_dark_mode {
diff --git a/compiler/rustc_mir/src/dataflow/framework/graphviz.rs b/compiler/rustc_mir/src/dataflow/framework/graphviz.rs
index 5d4c4251961..4e54257a1cb 100644
--- a/compiler/rustc_mir/src/dataflow/framework/graphviz.rs
+++ b/compiler/rustc_mir/src/dataflow/framework/graphviz.rs
@@ -6,7 +6,6 @@ use std::{io, ops, str};
 
 use regex::Regex;
 use rustc_graphviz as dot;
-use rustc_hir::def_id::DefId;
 use rustc_middle::mir::{self, BasicBlock, Body, Location};
 
 use super::fmt::{DebugDiffWithAdapter, DebugWithAdapter, DebugWithContext};
@@ -33,7 +32,6 @@ where
     A: Analysis<'tcx>,
 {
     body: &'a Body<'tcx>,
-    def_id: DefId,
     results: &'a Results<'tcx, A>,
     style: OutputStyle,
 }
@@ -42,13 +40,8 @@ impl<A> Formatter<'a, 'tcx, A>
 where
     A: Analysis<'tcx>,
 {
-    pub fn new(
-        body: &'a Body<'tcx>,
-        def_id: DefId,
-        results: &'a Results<'tcx, A>,
-        style: OutputStyle,
-    ) -> Self {
-        Formatter { body, def_id, results, style }
+    pub fn new(body: &'a Body<'tcx>, results: &'a Results<'tcx, A>, style: OutputStyle) -> Self {
+        Formatter { body, results, style }
     }
 }
 
@@ -77,7 +70,7 @@ where
     type Edge = CfgEdge;
 
     fn graph_id(&self) -> dot::Id<'_> {
-        let name = graphviz_safe_def_name(self.def_id);
+        let name = graphviz_safe_def_name(self.body.source.def_id());
         dot::Id::new(format!("graph_for_def_id_{}", name)).unwrap()
     }
 
diff --git a/compiler/rustc_mir/src/dataflow/framework/mod.rs b/compiler/rustc_mir/src/dataflow/framework/mod.rs
index 65c159e6a72..524ad0af1a7 100644
--- a/compiler/rustc_mir/src/dataflow/framework/mod.rs
+++ b/compiler/rustc_mir/src/dataflow/framework/mod.rs
@@ -13,9 +13,9 @@
 //! ```ignore(cross-crate-imports)
 //! use rustc_mir::dataflow::Analysis; // Makes `into_engine` available.
 //!
-//! fn do_my_analysis(tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>, did: DefId) {
+//! fn do_my_analysis(tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>) {
 //!     let analysis = MyAnalysis::new()
-//!         .into_engine(tcx, body, did)
+//!         .into_engine(tcx, body)
 //!         .iterate_to_fixpoint()
 //!         .into_results_cursor(body);
 //!
@@ -33,7 +33,6 @@
 use std::borrow::BorrowMut;
 use std::cmp::Ordering;
 
-use rustc_hir::def_id::DefId;
 use rustc_index::bit_set::{BitSet, HybridBitSet};
 use rustc_index::vec::Idx;
 use rustc_middle::mir::{self, BasicBlock, Location};
@@ -218,16 +217,11 @@ pub trait Analysis<'tcx>: AnalysisDomain<'tcx> {
     ///     .iterate_to_fixpoint()
     ///     .into_results_cursor(body);
     /// ```
-    fn into_engine(
-        self,
-        tcx: TyCtxt<'tcx>,
-        body: &'mir mir::Body<'tcx>,
-        def_id: DefId,
-    ) -> Engine<'mir, 'tcx, Self>
+    fn into_engine(self, tcx: TyCtxt<'tcx>, body: &'mir mir::Body<'tcx>) -> Engine<'mir, 'tcx, Self>
     where
         Self: Sized,
     {
-        Engine::new_generic(tcx, body, def_id, self)
+        Engine::new_generic(tcx, body, self)
     }
 }
 
@@ -381,16 +375,11 @@ where
 
     /* Extension methods */
 
-    fn into_engine(
-        self,
-        tcx: TyCtxt<'tcx>,
-        body: &'mir mir::Body<'tcx>,
-        def_id: DefId,
-    ) -> Engine<'mir, 'tcx, Self>
+    fn into_engine(self, tcx: TyCtxt<'tcx>, body: &'mir mir::Body<'tcx>) -> Engine<'mir, 'tcx, Self>
     where
         Self: Sized,
     {
-        Engine::new_gen_kill(tcx, body, def_id, self)
+        Engine::new_gen_kill(tcx, body, self)
     }
 }
 
diff --git a/compiler/rustc_mir/src/transform/add_moves_for_packed_drops.rs b/compiler/rustc_mir/src/transform/add_moves_for_packed_drops.rs
index 977bc853100..417e0a51aec 100644
--- a/compiler/rustc_mir/src/transform/add_moves_for_packed_drops.rs
+++ b/compiler/rustc_mir/src/transform/add_moves_for_packed_drops.rs
@@ -1,4 +1,3 @@
-use rustc_hir::def_id::DefId;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 
@@ -42,20 +41,17 @@ pub struct AddMovesForPackedDrops;
 impl<'tcx> MirPass<'tcx> for AddMovesForPackedDrops {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         debug!("add_moves_for_packed_drops({:?} @ {:?})", body.source, body.span);
-        add_moves_for_packed_drops(tcx, body, body.source.def_id());
+        add_moves_for_packed_drops(tcx, body);
     }
 }
 
-pub fn add_moves_for_packed_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>, def_id: DefId) {
-    let patch = add_moves_for_packed_drops_patch(tcx, body, def_id);
+pub fn add_moves_for_packed_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    let patch = add_moves_for_packed_drops_patch(tcx, body);
     patch.apply(body);
 }
 
-fn add_moves_for_packed_drops_patch<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    body: &Body<'tcx>,
-    def_id: DefId,
-) -> MirPatch<'tcx> {
+fn add_moves_for_packed_drops_patch<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) -> MirPatch<'tcx> {
+    let def_id = body.source.def_id();
     let mut patch = MirPatch::new(body);
     let param_env = tcx.param_env(def_id);
 
diff --git a/compiler/rustc_mir/src/transform/check_consts/mod.rs b/compiler/rustc_mir/src/transform/check_consts/mod.rs
index 8df134860a5..33815ceba62 100644
--- a/compiler/rustc_mir/src/transform/check_consts/mod.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/mod.rs
@@ -24,25 +24,28 @@ pub mod validation;
 pub struct ConstCx<'mir, 'tcx> {
     pub body: &'mir mir::Body<'tcx>,
     pub tcx: TyCtxt<'tcx>,
-    pub def_id: LocalDefId,
     pub param_env: ty::ParamEnv<'tcx>,
     pub const_kind: Option<hir::ConstContext>,
 }
 
 impl ConstCx<'mir, 'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &'mir mir::Body<'tcx>) -> Self {
+    pub fn new(tcx: TyCtxt<'tcx>, body: &'mir mir::Body<'tcx>) -> Self {
+        let def_id = body.source.def_id().expect_local();
         let param_env = tcx.param_env(def_id);
-        Self::new_with_param_env(tcx, def_id, body, param_env)
+        Self::new_with_param_env(tcx, body, param_env)
     }
 
     pub fn new_with_param_env(
         tcx: TyCtxt<'tcx>,
-        def_id: LocalDefId,
         body: &'mir mir::Body<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
     ) -> Self {
-        let const_kind = tcx.hir().body_const_context(def_id);
-        ConstCx { body, tcx, def_id: def_id, param_env, const_kind }
+        let const_kind = tcx.hir().body_const_context(body.source.def_id().expect_local());
+        ConstCx { body, tcx, param_env, const_kind }
+    }
+
+    pub fn def_id(&self) -> LocalDefId {
+        self.body.source.def_id().expect_local()
     }
 
     /// Returns the kind of const context this `Item` represents (`const`, `static`, etc.).
@@ -55,7 +58,7 @@ impl ConstCx<'mir, 'tcx> {
     pub fn is_const_stable_const_fn(&self) -> bool {
         self.const_kind == Some(hir::ConstContext::ConstFn)
             && self.tcx.features().staged_api
-            && is_const_stable_const_fn(self.tcx, self.def_id.to_def_id())
+            && is_const_stable_const_fn(self.tcx, self.def_id().to_def_id())
     }
 
     /// Returns the function signature of the item being const-checked if it is a `fn` or `const fn`.
@@ -64,7 +67,7 @@ impl ConstCx<'mir, 'tcx> {
         //
         // FIXME: Is this still an issue?
         let hir_map = self.tcx.hir();
-        let hir_id = hir_map.local_def_id_to_hir_id(self.def_id);
+        let hir_id = hir_map.local_def_id_to_hir_id(self.def_id());
         hir_map.fn_sig_by_hir_id(hir_id)
     }
 }
diff --git a/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs b/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs
index 9b2568d5abb..1a2d932ba19 100644
--- a/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs
@@ -1,4 +1,3 @@
-use rustc_hir::def_id::LocalDefId;
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::{self, BasicBlock, Location};
 use rustc_middle::ty::TyCtxt;
@@ -24,13 +23,14 @@ pub fn checking_enabled(ccx: &ConstCx<'_, '_>) -> bool {
 ///
 /// This is separate from the rest of the const checking logic because it must run after drop
 /// elaboration.
-pub fn check_live_drops(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &mir::Body<'tcx>) {
+pub fn check_live_drops(tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>) {
+    let def_id = body.source.def_id().expect_local();
     let const_kind = tcx.hir().body_const_context(def_id);
     if const_kind.is_none() {
         return;
     }
 
-    let ccx = ConstCx { body, tcx, def_id, const_kind, param_env: tcx.param_env(def_id) };
+    let ccx = ConstCx { body, tcx, const_kind, param_env: tcx.param_env(def_id) };
     if !checking_enabled(&ccx) {
         return;
     }
diff --git a/compiler/rustc_mir/src/transform/check_consts/qualifs.rs b/compiler/rustc_mir/src/transform/check_consts/qualifs.rs
index 3f4b3ca2eed..b3d9beb3742 100644
--- a/compiler/rustc_mir/src/transform/check_consts/qualifs.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/qualifs.rs
@@ -126,7 +126,7 @@ impl Qualif for CustomEq {
         // because that component may be part of an enum variant (e.g.,
         // `Option::<NonStructuralMatchTy>::Some`), in which case some values of this type may be
         // structural-match (`Option::None`).
-        let id = cx.tcx.hir().local_def_id_to_hir_id(cx.def_id);
+        let id = cx.tcx.hir().local_def_id_to_hir_id(cx.def_id());
         traits::search_for_structural_match_violation(id, cx.body.span, cx.tcx, ty).is_some()
     }
 
diff --git a/compiler/rustc_mir/src/transform/check_consts/validation.rs b/compiler/rustc_mir/src/transform/check_consts/validation.rs
index 94806116eaf..587b5b38128 100644
--- a/compiler/rustc_mir/src/transform/check_consts/validation.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/validation.rs
@@ -50,7 +50,7 @@ impl Qualifs<'mir, 'tcx> {
         location: Location,
     ) -> bool {
         let indirectly_mutable = self.indirectly_mutable.get_or_insert_with(|| {
-            let ConstCx { tcx, body, def_id, param_env, .. } = *ccx;
+            let ConstCx { tcx, body, param_env, .. } = *ccx;
 
             // We can use `unsound_ignore_borrow_on_drop` here because custom drop impls are not
             // allowed in a const.
@@ -59,7 +59,7 @@ impl Qualifs<'mir, 'tcx> {
             // without breaking stable code?
             MaybeMutBorrowedLocals::mut_borrows_only(tcx, &body, param_env)
                 .unsound_ignore_borrow_on_drop()
-                .into_engine(tcx, &body, def_id.to_def_id())
+                .into_engine(tcx, &body)
                 .pass_name("const_qualification")
                 .iterate_to_fixpoint()
                 .into_results_cursor(&body)
@@ -84,10 +84,10 @@ impl Qualifs<'mir, 'tcx> {
         }
 
         let needs_drop = self.needs_drop.get_or_insert_with(|| {
-            let ConstCx { tcx, body, def_id, .. } = *ccx;
+            let ConstCx { tcx, body, .. } = *ccx;
 
             FlowSensitiveAnalysis::new(NeedsDrop, ccx)
-                .into_engine(tcx, &body, def_id.to_def_id())
+                .into_engine(tcx, &body)
                 .iterate_to_fixpoint()
                 .into_results_cursor(&body)
         });
@@ -111,10 +111,10 @@ impl Qualifs<'mir, 'tcx> {
         }
 
         let has_mut_interior = self.has_mut_interior.get_or_insert_with(|| {
-            let ConstCx { tcx, body, def_id, .. } = *ccx;
+            let ConstCx { tcx, body, .. } = *ccx;
 
             FlowSensitiveAnalysis::new(HasMutInterior, ccx)
-                .into_engine(tcx, &body, def_id.to_def_id())
+                .into_engine(tcx, &body)
                 .iterate_to_fixpoint()
                 .into_results_cursor(&body)
         });
@@ -157,7 +157,7 @@ impl Qualifs<'mir, 'tcx> {
 
             hir::ConstContext::Const | hir::ConstContext::Static(_) => {
                 let mut cursor = FlowSensitiveAnalysis::new(CustomEq, ccx)
-                    .into_engine(ccx.tcx, &ccx.body, ccx.def_id.to_def_id())
+                    .into_engine(ccx.tcx, &ccx.body)
                     .iterate_to_fixpoint()
                     .into_results_cursor(&ccx.body);
 
@@ -205,7 +205,8 @@ impl Validator<'mir, 'tcx> {
     }
 
     pub fn check_body(&mut self) {
-        let ConstCx { tcx, body, def_id, .. } = *self.ccx;
+        let ConstCx { tcx, body, .. } = *self.ccx;
+        let def_id = self.ccx.def_id();
 
         // `async` functions cannot be `const fn`. This is checked during AST lowering, so there's
         // no need to emit duplicate errors here.
@@ -219,7 +220,7 @@ impl Validator<'mir, 'tcx> {
             // Prevent const trait methods from being annotated as `stable`.
             // FIXME: Do this as part of stability checking.
             if self.is_const_stable_const_fn() {
-                let hir_id = tcx.hir().local_def_id_to_hir_id(self.def_id);
+                let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
                 if crate::const_eval::is_parent_const_impl_raw(tcx, hir_id) {
                     struct_span_err!(
                         self.ccx.tcx.sess,
@@ -291,7 +292,7 @@ impl Validator<'mir, 'tcx> {
 
             Status::Unstable(gate) if self.tcx.features().enabled(gate) => {
                 let unstable_in_stable = self.ccx.is_const_stable_const_fn()
-                    && !super::allow_internal_unstable(self.tcx, self.def_id.to_def_id(), gate);
+                    && !super::allow_internal_unstable(self.tcx, self.def_id().to_def_id(), gate);
                 if unstable_in_stable {
                     emit_unstable_in_stable_error(self.ccx, span, gate);
                 }
@@ -367,9 +368,9 @@ impl Validator<'mir, 'tcx> {
     }
 
     fn check_item_predicates(&mut self) {
-        let ConstCx { tcx, def_id, .. } = *self.ccx;
+        let ConstCx { tcx, .. } = *self.ccx;
 
-        let mut current = def_id.to_def_id();
+        let mut current = self.def_id().to_def_id();
         loop {
             let predicates = tcx.predicates_of(current);
             for (predicate, _) in predicates.predicates {
@@ -736,8 +737,8 @@ impl Visitor<'tcx> for Validator<'mir, 'tcx> {
 
         match &terminator.kind {
             TerminatorKind::Call { func, .. } => {
-                let ConstCx { tcx, body, def_id: caller, param_env, .. } = *self.ccx;
-                let caller = caller.to_def_id();
+                let ConstCx { tcx, body, param_env, .. } = *self.ccx;
+                let caller = self.def_id().to_def_id();
 
                 let fn_ty = func.ty(body, tcx);
 
diff --git a/compiler/rustc_mir/src/transform/dest_prop.rs b/compiler/rustc_mir/src/transform/dest_prop.rs
index 0982bcfb0ca..410f462ed46 100644
--- a/compiler/rustc_mir/src/transform/dest_prop.rs
+++ b/compiler/rustc_mir/src/transform/dest_prop.rs
@@ -408,15 +408,12 @@ impl Conflicts<'a> {
             body.local_decls.len(),
         );
 
-        let def_id = body.source.def_id();
         let mut init = MaybeInitializedLocals
-            .into_engine(tcx, body, def_id)
-            .iterate_to_fixpoint()
-            .into_results_cursor(body);
-        let mut live = MaybeLiveLocals
-            .into_engine(tcx, body, def_id)
+            .into_engine(tcx, body)
             .iterate_to_fixpoint()
             .into_results_cursor(body);
+        let mut live =
+            MaybeLiveLocals.into_engine(tcx, body).iterate_to_fixpoint().into_results_cursor(body);
 
         let mut reachable = None;
         dump_mir(tcx, None, "DestinationPropagation-dataflow", &"", body, |pass_where, w| {
diff --git a/compiler/rustc_mir/src/transform/elaborate_drops.rs b/compiler/rustc_mir/src/transform/elaborate_drops.rs
index f59050f5838..3d435f6d0e7 100644
--- a/compiler/rustc_mir/src/transform/elaborate_drops.rs
+++ b/compiler/rustc_mir/src/transform/elaborate_drops.rs
@@ -10,7 +10,6 @@ use crate::util::elaborate_drops::{elaborate_drop, DropFlagState, Unwind};
 use crate::util::elaborate_drops::{DropElaborator, DropFlagMode, DropStyle};
 use crate::util::patch::MirPatch;
 use rustc_data_structures::fx::FxHashMap;
-use rustc_hir as hir;
 use rustc_index::bit_set::BitSet;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, TyCtxt};
@@ -39,10 +38,10 @@ impl<'tcx> MirPass<'tcx> for ElaborateDrops {
         let elaborate_patch = {
             let body = &*body;
             let env = MoveDataParamEnv { move_data, param_env };
-            let dead_unwinds = find_dead_unwinds(tcx, body, def_id, &env);
+            let dead_unwinds = find_dead_unwinds(tcx, body, &env);
 
             let inits = MaybeInitializedPlaces::new(tcx, body, &env)
-                .into_engine(tcx, body, def_id)
+                .into_engine(tcx, body)
                 .dead_unwinds(&dead_unwinds)
                 .pass_name("elaborate_drops")
                 .iterate_to_fixpoint()
@@ -50,7 +49,7 @@ impl<'tcx> MirPass<'tcx> for ElaborateDrops {
 
             let uninits = MaybeUninitializedPlaces::new(tcx, body, &env)
                 .mark_inactive_variants_as_uninit()
-                .into_engine(tcx, body, def_id)
+                .into_engine(tcx, body)
                 .dead_unwinds(&dead_unwinds)
                 .pass_name("elaborate_drops")
                 .iterate_to_fixpoint()
@@ -76,7 +75,6 @@ impl<'tcx> MirPass<'tcx> for ElaborateDrops {
 fn find_dead_unwinds<'tcx>(
     tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
-    def_id: hir::def_id::DefId,
     env: &MoveDataParamEnv<'tcx>,
 ) -> BitSet<BasicBlock> {
     debug!("find_dead_unwinds({:?})", body.span);
@@ -84,7 +82,7 @@ fn find_dead_unwinds<'tcx>(
     // reach cleanup blocks, which can't have unwind edges themselves.
     let mut dead_unwinds = BitSet::new_empty(body.basic_blocks().len());
     let mut flow_inits = MaybeInitializedPlaces::new(tcx, body, &env)
-        .into_engine(tcx, body, def_id)
+        .into_engine(tcx, body)
         .pass_name("find_dead_unwinds")
         .iterate_to_fixpoint()
         .into_results_cursor(body);
diff --git a/compiler/rustc_mir/src/transform/generator.rs b/compiler/rustc_mir/src/transform/generator.rs
index 7c3a0502dec..924bb4996fc 100644
--- a/compiler/rustc_mir/src/transform/generator.rs
+++ b/compiler/rustc_mir/src/transform/generator.rs
@@ -61,7 +61,6 @@ use crate::util::expand_aggregate;
 use crate::util::storage;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_index::bit_set::{BitMatrix, BitSet};
 use rustc_index::vec::{Idx, IndexVec};
@@ -454,20 +453,19 @@ fn locals_live_across_suspend_points(
     always_live_locals: &storage::AlwaysLiveLocals,
     movable: bool,
 ) -> LivenessInfo {
-    let def_id = body.source.def_id();
     let body_ref: &Body<'_> = &body;
 
     // Calculate when MIR locals have live storage. This gives us an upper bound of their
     // lifetimes.
     let mut storage_live = MaybeStorageLive::new(always_live_locals.clone())
-        .into_engine(tcx, body_ref, def_id)
+        .into_engine(tcx, body_ref)
         .iterate_to_fixpoint()
         .into_results_cursor(body_ref);
 
     // Calculate the MIR locals which have been previously
     // borrowed (even if they are still active).
     let borrowed_locals_results = MaybeBorrowedLocals::all_borrows()
-        .into_engine(tcx, body_ref, def_id)
+        .into_engine(tcx, body_ref)
         .pass_name("generator")
         .iterate_to_fixpoint();
 
@@ -477,14 +475,14 @@ fn locals_live_across_suspend_points(
     // Calculate the MIR locals that we actually need to keep storage around
     // for.
     let requires_storage_results = MaybeRequiresStorage::new(body, &borrowed_locals_results)
-        .into_engine(tcx, body_ref, def_id)
+        .into_engine(tcx, body_ref)
         .iterate_to_fixpoint();
     let mut requires_storage_cursor =
         dataflow::ResultsCursor::new(body_ref, &requires_storage_results);
 
     // Calculate the liveness of MIR locals ignoring borrows.
     let mut liveness = MaybeLiveLocals
-        .into_engine(tcx, body_ref, def_id)
+        .into_engine(tcx, body_ref)
         .pass_name("generator")
         .iterate_to_fixpoint()
         .into_results_cursor(body_ref);
@@ -722,11 +720,11 @@ impl<'body, 'tcx, 's> StorageConflictVisitor<'body, 'tcx, 's> {
 fn sanitize_witness<'tcx>(
     tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
-    did: DefId,
     witness: Ty<'tcx>,
     upvars: &Vec<Ty<'tcx>>,
     saved_locals: &GeneratorSavedLocals,
 ) {
+    let did = body.source.def_id();
     let allowed_upvars = tcx.erase_regions(upvars);
     let allowed = match witness.kind() {
         ty::GeneratorWitness(s) => tcx.erase_late_bound_regions(&s),
@@ -865,7 +863,7 @@ fn insert_switch<'tcx>(
     }
 }
 
-fn elaborate_generator_drops<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, body: &mut Body<'tcx>) {
+fn elaborate_generator_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
     use crate::shim::DropShimElaborator;
     use crate::util::elaborate_drops::{elaborate_drop, Unwind};
     use crate::util::patch::MirPatch;
@@ -874,6 +872,7 @@ fn elaborate_generator_drops<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, body: &mut
     // this is ok because `open_drop` can only be reached within that own
     // generator's resume function.
 
+    let def_id = body.source.def_id();
     let param_env = tcx.param_env(def_id);
 
     let mut elaborator = DropShimElaborator { body, patch: MirPatch::new(body), tcx, param_env };
@@ -1246,8 +1245,6 @@ impl<'tcx> MirPass<'tcx> for StateTransform {
 
         assert!(body.generator_drop.is_none());
 
-        let def_id = body.source.def_id();
-
         // The first argument is the generator type passed by value
         let gen_ty = body.local_decls.raw[1].ty;
 
@@ -1306,7 +1303,7 @@ impl<'tcx> MirPass<'tcx> for StateTransform {
         let liveness_info =
             locals_live_across_suspend_points(tcx, body, &always_live_locals, movable);
 
-        sanitize_witness(tcx, body, def_id, interior, &upvars, &liveness_info.saved_locals);
+        sanitize_witness(tcx, body, interior, &upvars, &liveness_info.saved_locals);
 
         if tcx.sess.opts.debugging_opts.validate_mir {
             let mut vis = EnsureGeneratorFieldAssignmentsNeverAlias {
@@ -1358,7 +1355,7 @@ impl<'tcx> MirPass<'tcx> for StateTransform {
         // Expand `drop(generator_struct)` to a drop ladder which destroys upvars.
         // If any upvars are moved out of, drop elaboration will handle upvar destruction.
         // However we need to also elaborate the code generated by `insert_clean_drop`.
-        elaborate_generator_drops(tcx, def_id, body);
+        elaborate_generator_drops(tcx, body);
 
         dump_mir(tcx, None, "generator_post-transform", &0, body, |_, _| Ok(()));
 
diff --git a/compiler/rustc_mir/src/transform/mod.rs b/compiler/rustc_mir/src/transform/mod.rs
index d8bc00c5f3f..b4f5947f5a3 100644
--- a/compiler/rustc_mir/src/transform/mod.rs
+++ b/compiler/rustc_mir/src/transform/mod.rs
@@ -229,13 +229,7 @@ fn mir_const_qualif(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) ->
         return Default::default();
     }
 
-    let ccx = check_consts::ConstCx {
-        body,
-        tcx,
-        def_id: def.did,
-        const_kind,
-        param_env: tcx.param_env(def.did),
-    };
+    let ccx = check_consts::ConstCx { body, tcx, const_kind, param_env: tcx.param_env(def.did) };
 
     let mut validator = check_consts::validation::Validator::new(&ccx);
     validator.check_body();
@@ -346,7 +340,7 @@ fn mir_drops_elaborated_and_const_checked<'tcx>(
     let mut body = body.steal();
 
     run_post_borrowck_cleanup_passes(tcx, &mut body);
-    check_consts::post_drop_elaboration::check_live_drops(tcx, def.did, &body);
+    check_consts::post_drop_elaboration::check_live_drops(tcx, &body);
     tcx.alloc_steal_mir(body)
 }
 
diff --git a/compiler/rustc_mir/src/transform/promote_consts.rs b/compiler/rustc_mir/src/transform/promote_consts.rs
index 7ad659bddbe..7abc998d388 100644
--- a/compiler/rustc_mir/src/transform/promote_consts.rs
+++ b/compiler/rustc_mir/src/transform/promote_consts.rs
@@ -60,15 +60,13 @@ impl<'tcx> MirPass<'tcx> for PromoteTemps<'tcx> {
             return;
         }
 
-        let def = body.source.with_opt_param().expect_local();
-
         let mut rpo = traversal::reverse_postorder(body);
-        let ccx = ConstCx::new(tcx, def.did, body);
+        let ccx = ConstCx::new(tcx, body);
         let (temps, all_candidates) = collect_temps_and_candidates(&ccx, &mut rpo);
 
         let promotable_candidates = validate_candidates(&ccx, &temps, &all_candidates);
 
-        let promoted = promote_candidates(def.to_global(), body, tcx, temps, promotable_candidates);
+        let promoted = promote_candidates(body, tcx, temps, promotable_candidates);
         self.promoted_fragments.set(promoted);
     }
 }
@@ -758,7 +756,7 @@ impl<'tcx> Validator<'_, 'tcx> {
             ty::FnDef(def_id, _) => {
                 is_const_fn(self.tcx, def_id)
                     || is_unstable_const_fn(self.tcx, def_id).is_some()
-                    || is_lang_panic_fn(self.tcx, self.def_id.to_def_id())
+                    || is_lang_panic_fn(self.tcx, def_id)
             }
             _ => false,
         };
@@ -970,10 +968,10 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> {
 
     fn promote_candidate(
         mut self,
-        def: ty::WithOptConstParam<DefId>,
         candidate: Candidate,
         next_promoted_id: usize,
     ) -> Option<Body<'tcx>> {
+        let def = self.source.source.with_opt_param();
         let mut rvalue = {
             let promoted = &mut self.promoted;
             let promoted_id = Promoted::new(next_promoted_id);
@@ -1133,7 +1131,6 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Promoter<'a, 'tcx> {
 }
 
 pub fn promote_candidates<'tcx>(
-    def: ty::WithOptConstParam<DefId>,
     body: &mut Body<'tcx>,
     tcx: TyCtxt<'tcx>,
     mut temps: IndexVec<Local, TempState>,
@@ -1191,7 +1188,7 @@ pub fn promote_candidates<'tcx>(
         };
 
         //FIXME(oli-obk): having a `maybe_push()` method on `IndexVec` might be nice
-        if let Some(mut promoted) = promoter.promote_candidate(def, candidate, promotions.len()) {
+        if let Some(mut promoted) = promoter.promote_candidate(candidate, promotions.len()) {
             promoted.source.promoted = Some(promotions.next_index());
             promotions.push(promoted);
         }
@@ -1250,7 +1247,9 @@ crate fn should_suggest_const_in_array_repeat_expressions_attribute<'tcx>(
     debug!(
         "should_suggest_const_in_array_repeat_expressions_flag: def_id={:?} \
             should_promote={:?} feature_flag={:?}",
-        validator.ccx.def_id, should_promote, feature_flag
+        validator.ccx.def_id(),
+        should_promote,
+        feature_flag
     );
     should_promote && !feature_flag
 }
diff --git a/compiler/rustc_mir/src/transform/remove_unneeded_drops.rs b/compiler/rustc_mir/src/transform/remove_unneeded_drops.rs
index cfee656eda4..aaf3ecab4dc 100644
--- a/compiler/rustc_mir/src/transform/remove_unneeded_drops.rs
+++ b/compiler/rustc_mir/src/transform/remove_unneeded_drops.rs
@@ -1,10 +1,9 @@
 //! This pass replaces a drop of a type that does not need dropping, with a goto
 
 use crate::transform::MirPass;
-use rustc_hir::def_id::LocalDefId;
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::*;
-use rustc_middle::ty::TyCtxt;
+use rustc_middle::ty::{ParamEnv, TyCtxt};
 
 use super::simplify::simplify_cfg;
 
@@ -16,8 +15,8 @@ impl<'tcx> MirPass<'tcx> for RemoveUnneededDrops {
         let mut opt_finder = RemoveUnneededDropsOptimizationFinder {
             tcx,
             body,
+            param_env: tcx.param_env(body.source.def_id()),
             optimizations: vec![],
-            def_id: body.source.def_id().expect_local(),
         };
         opt_finder.visit_body(body);
         let should_simplify = !opt_finder.optimizations.is_empty();
@@ -40,7 +39,7 @@ impl<'a, 'tcx> Visitor<'tcx> for RemoveUnneededDropsOptimizationFinder<'a, 'tcx>
         match terminator.kind {
             TerminatorKind::Drop { place, target, .. } => {
                 let ty = place.ty(self.body, self.tcx);
-                let needs_drop = ty.ty.needs_drop(self.tcx, self.tcx.param_env(self.def_id));
+                let needs_drop = ty.ty.needs_drop(self.tcx, self.param_env);
                 if !needs_drop {
                     self.optimizations.push((location, target));
                 }
@@ -54,5 +53,5 @@ pub struct RemoveUnneededDropsOptimizationFinder<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     body: &'a Body<'tcx>,
     optimizations: Vec<(Location, BasicBlock)>,
-    def_id: LocalDefId,
+    param_env: ParamEnv<'tcx>,
 }
diff --git a/compiler/rustc_mir/src/transform/rustc_peek.rs b/compiler/rustc_mir/src/transform/rustc_peek.rs
index 366041581c2..205f718d6e4 100644
--- a/compiler/rustc_mir/src/transform/rustc_peek.rs
+++ b/compiler/rustc_mir/src/transform/rustc_peek.rs
@@ -6,7 +6,6 @@ use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 
 use crate::transform::MirPass;
-use rustc_hir::def_id::DefId;
 use rustc_index::bit_set::BitSet;
 use rustc_middle::mir::{self, Body, Local, Location};
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -41,41 +40,40 @@ impl<'tcx> MirPass<'tcx> for SanityCheck {
 
         if has_rustc_mir_with(sess, &attributes, sym::rustc_peek_maybe_init).is_some() {
             let flow_inits = MaybeInitializedPlaces::new(tcx, body, &mdpe)
-                .into_engine(tcx, body, def_id)
+                .into_engine(tcx, body)
                 .iterate_to_fixpoint();
 
-            sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_inits);
+            sanity_check_via_rustc_peek(tcx, body, &attributes, &flow_inits);
         }
 
         if has_rustc_mir_with(sess, &attributes, sym::rustc_peek_maybe_uninit).is_some() {
             let flow_uninits = MaybeUninitializedPlaces::new(tcx, body, &mdpe)
-                .into_engine(tcx, body, def_id)
+                .into_engine(tcx, body)
                 .iterate_to_fixpoint();
 
-            sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_uninits);
+            sanity_check_via_rustc_peek(tcx, body, &attributes, &flow_uninits);
         }
 
         if has_rustc_mir_with(sess, &attributes, sym::rustc_peek_definite_init).is_some() {
             let flow_def_inits = DefinitelyInitializedPlaces::new(tcx, body, &mdpe)
-                .into_engine(tcx, body, def_id)
+                .into_engine(tcx, body)
                 .iterate_to_fixpoint();
 
-            sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_def_inits);
+            sanity_check_via_rustc_peek(tcx, body, &attributes, &flow_def_inits);
         }
 
         if has_rustc_mir_with(sess, &attributes, sym::rustc_peek_indirectly_mutable).is_some() {
             let flow_mut_borrowed = MaybeMutBorrowedLocals::mut_borrows_only(tcx, body, param_env)
-                .into_engine(tcx, body, def_id)
+                .into_engine(tcx, body)
                 .iterate_to_fixpoint();
 
-            sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_mut_borrowed);
+            sanity_check_via_rustc_peek(tcx, body, &attributes, &flow_mut_borrowed);
         }
 
         if has_rustc_mir_with(sess, &attributes, sym::rustc_peek_liveness).is_some() {
-            let flow_liveness =
-                MaybeLiveLocals.into_engine(tcx, body, def_id).iterate_to_fixpoint();
+            let flow_liveness = MaybeLiveLocals.into_engine(tcx, body).iterate_to_fixpoint();
 
-            sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_liveness);
+            sanity_check_via_rustc_peek(tcx, body, &attributes, &flow_liveness);
         }
 
         if has_rustc_mir_with(sess, &attributes, sym::stop_after_dataflow).is_some() {
@@ -103,12 +101,12 @@ impl<'tcx> MirPass<'tcx> for SanityCheck {
 pub fn sanity_check_via_rustc_peek<'tcx, A>(
     tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
-    def_id: DefId,
     _attributes: &[ast::Attribute],
     results: &Results<'tcx, A>,
 ) where
     A: RustcPeekAt<'tcx>,
 {
+    let def_id = body.source.def_id();
     debug!("sanity_check_via_rustc_peek def_id: {:?}", def_id);
 
     let mut cursor = ResultsCursor::new(body, results);
diff --git a/compiler/rustc_mir/src/transform/validate.rs b/compiler/rustc_mir/src/transform/validate.rs
index 0c3580584ff..cf51e86c5bc 100644
--- a/compiler/rustc_mir/src/transform/validate.rs
+++ b/compiler/rustc_mir/src/transform/validate.rs
@@ -38,7 +38,7 @@ impl<'tcx> MirPass<'tcx> for Validator {
 
         let always_live_locals = AlwaysLiveLocals::new(body);
         let storage_liveness = MaybeStorageLive::new(always_live_locals)
-            .into_engine(tcx, body, def_id)
+            .into_engine(tcx, body)
             .iterate_to_fixpoint()
             .into_results_cursor(body);
 
diff --git a/compiler/rustc_mir/src/util/graphviz.rs b/compiler/rustc_mir/src/util/graphviz.rs
index 857617e546e..e04f07774ed 100644
--- a/compiler/rustc_mir/src/util/graphviz.rs
+++ b/compiler/rustc_mir/src/util/graphviz.rs
@@ -72,16 +72,16 @@ where
     writeln!(w, r#"    edge [{}];"#, content_attrs_str)?;
 
     // Graph label
-    write_graph_label(tcx, def_id, body, w)?;
+    write_graph_label(tcx, body, w)?;
 
     // Nodes
     for (block, _) in body.basic_blocks().iter_enumerated() {
-        write_node(def_id, block, body, dark_mode, w)?;
+        write_node(block, body, dark_mode, w)?;
     }
 
     // Edges
     for (source, _) in body.basic_blocks().iter_enumerated() {
-        write_edges(def_id, source, body, w)?;
+        write_edges(source, body, w)?;
     }
     writeln!(w, "}}")
 }
@@ -151,12 +151,12 @@ where
 
 /// Write a graphviz DOT node for the given basic block.
 fn write_node<W: Write>(
-    def_id: DefId,
     block: BasicBlock,
     body: &Body<'_>,
     dark_mode: bool,
     w: &mut W,
 ) -> io::Result<()> {
+    let def_id = body.source.def_id();
     // Start a new node with the label to follow, in one of DOT's pseudo-HTML tables.
     write!(w, r#"    {} [shape="none", label=<"#, node(def_id, block))?;
     write_node_label(block, body, dark_mode, w, 1, |_| Ok(()), |_| Ok(()))?;
@@ -165,12 +165,8 @@ fn write_node<W: Write>(
 }
 
 /// Write graphviz DOT edges with labels between the given basic block and all of its successors.
-fn write_edges<W: Write>(
-    def_id: DefId,
-    source: BasicBlock,
-    body: &Body<'_>,
-    w: &mut W,
-) -> io::Result<()> {
+fn write_edges<W: Write>(source: BasicBlock, body: &Body<'_>, w: &mut W) -> io::Result<()> {
+    let def_id = body.source.def_id();
     let terminator = body[source].terminator();
     let labels = terminator.kind.fmt_successor_labels();
 
@@ -188,10 +184,11 @@ fn write_edges<W: Write>(
 /// all the variables and temporaries.
 fn write_graph_label<'tcx, W: Write>(
     tcx: TyCtxt<'tcx>,
-    def_id: DefId,
     body: &Body<'_>,
     w: &mut W,
 ) -> io::Result<()> {
+    let def_id = body.source.def_id();
+
     write!(w, "    label=<fn {}(", dot::escape_html(&tcx.def_path_str(def_id)))?;
 
     // fn argument types.
diff --git a/compiler/rustc_mir/src/util/pretty.rs b/compiler/rustc_mir/src/util/pretty.rs
index ad871fde00f..c00c3b740ed 100644
--- a/compiler/rustc_mir/src/util/pretty.rs
+++ b/compiler/rustc_mir/src/util/pretty.rs
@@ -153,7 +153,7 @@ fn dump_matched_mir_node<'tcx, F>(
             let mut file =
                 create_dump_file(tcx, "html", pass_num, pass_name, disambiguator, body.source)?;
             if body.source.def_id().is_local() {
-                write_mir_fn_spanview(tcx, body.source.def_id(), body, spanview, &mut file)?;
+                write_mir_fn_spanview(tcx, body, spanview, &mut file)?;
             }
         };
     }
diff --git a/compiler/rustc_mir/src/util/spanview.rs b/compiler/rustc_mir/src/util/spanview.rs
index fe33fffe0ea..fdc724178b6 100644
--- a/compiler/rustc_mir/src/util/spanview.rs
+++ b/compiler/rustc_mir/src/util/spanview.rs
@@ -90,7 +90,6 @@ pub struct SpanViewable {
 /// Write a spanview HTML+CSS file to analyze MIR element spans.
 pub fn write_mir_fn_spanview<'tcx, W>(
     tcx: TyCtxt<'tcx>,
-    def_id: DefId,
     body: &Body<'tcx>,
     spanview: MirSpanview,
     w: &mut W,
@@ -98,6 +97,7 @@ pub fn write_mir_fn_spanview<'tcx, W>(
 where
     W: Write,
 {
+    let def_id = body.source.def_id();
     let body_span = hir_body(tcx, def_id).value.span;
     let mut span_viewables = Vec::new();
     for (bb, data) in body.basic_blocks().iter_enumerated() {
diff --git a/compiler/rustc_mir_build/src/build/mod.rs b/compiler/rustc_mir_build/src/build/mod.rs
index 2ff369069eb..220e3b11a6a 100644
--- a/compiler/rustc_mir_build/src/build/mod.rs
+++ b/compiler/rustc_mir_build/src/build/mod.rs
@@ -205,7 +205,7 @@ fn mir_build(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> Body<'_
             build::construct_const(cx, body_id, return_ty, return_ty_span)
         };
 
-        lints::check(tcx, &body, def.did);
+        lints::check(tcx, &body);
 
         // The borrow checker will replace all the regions here with its own
         // inference variables. There's no point having non-erased regions here.
diff --git a/compiler/rustc_mir_build/src/lints.rs b/compiler/rustc_mir_build/src/lints.rs
index a8d7c612a84..bdef02a011b 100644
--- a/compiler/rustc_mir_build/src/lints.rs
+++ b/compiler/rustc_mir_build/src/lints.rs
@@ -1,7 +1,6 @@
 use rustc_data_structures::graph::iterate::{
     ControlFlow, NodeStatus, TriColorDepthFirstSearch, TriColorVisitor,
 };
-use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::FnKind;
 use rustc_middle::hir::map::blocks::FnLikeNode;
 use rustc_middle::mir::{BasicBlock, Body, Operand, TerminatorKind};
@@ -10,7 +9,8 @@ use rustc_middle::ty::{self, AssocItem, AssocItemContainer, Instance, TyCtxt};
 use rustc_session::lint::builtin::UNCONDITIONAL_RECURSION;
 use rustc_span::Span;
 
-crate fn check<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, def_id: LocalDefId) {
+crate fn check<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) {
+    let def_id = body.source.def_id().expect_local();
     let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
 
     if let Some(fn_like_node) = FnLikeNode::from_node(tcx.hir().get(hir_id)) {
@@ -30,7 +30,7 @@ crate fn check<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, def_id: LocalDefId) {
             _ => &[],
         };
 
-        let mut vis = Search { tcx, body, def_id, reachable_recursive_calls: vec![], trait_substs };
+        let mut vis = Search { tcx, body, reachable_recursive_calls: vec![], trait_substs };
         if let Some(NonRecursive) = TriColorDepthFirstSearch::new(&body).run_from_start(&mut vis) {
             return;
         }
@@ -57,7 +57,6 @@ struct NonRecursive;
 struct Search<'mir, 'tcx> {
     tcx: TyCtxt<'tcx>,
     body: &'mir Body<'tcx>,
-    def_id: LocalDefId,
     trait_substs: &'tcx [GenericArg<'tcx>],
 
     reachable_recursive_calls: Vec<Span>,
@@ -66,16 +65,17 @@ struct Search<'mir, 'tcx> {
 impl<'mir, 'tcx> Search<'mir, 'tcx> {
     /// Returns `true` if `func` refers to the function we are searching in.
     fn is_recursive_call(&self, func: &Operand<'tcx>) -> bool {
-        let Search { tcx, body, def_id, trait_substs, .. } = *self;
-        let param_env = tcx.param_env(def_id);
+        let Search { tcx, body, trait_substs, .. } = *self;
+        let caller = body.source.def_id();
+        let param_env = tcx.param_env(caller);
 
         let func_ty = func.ty(body, tcx);
-        if let ty::FnDef(fn_def_id, substs) = *func_ty.kind() {
-            let (call_fn_id, call_substs) =
-                if let Ok(Some(instance)) = Instance::resolve(tcx, param_env, fn_def_id, substs) {
+        if let ty::FnDef(callee, substs) = *func_ty.kind() {
+            let (callee, call_substs) =
+                if let Ok(Some(instance)) = Instance::resolve(tcx, param_env, callee, substs) {
                     (instance.def_id(), instance.substs)
                 } else {
-                    (fn_def_id, substs)
+                    (callee, substs)
                 };
 
             // FIXME(#57965): Make this work across function boundaries
@@ -84,8 +84,7 @@ impl<'mir, 'tcx> Search<'mir, 'tcx> {
             // calling into an entirely different method (for example, a call from the default
             // method in the trait to `<A as Trait<B>>::method`, where `A` and/or `B` are
             // specific types).
-            return call_fn_id == def_id.to_def_id()
-                && &call_substs[..trait_substs.len()] == trait_substs;
+            return callee == caller && &call_substs[..trait_substs.len()] == trait_substs;
         }
 
         false
diff --git a/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs b/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs
index e5f7cc51111..80da04fb7de 100644
--- a/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs
@@ -118,7 +118,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
 
         let mir = cx.tcx.optimized_mir(def_id);
 
-        if let Err((span, err)) = is_min_const_fn(cx.tcx, def_id.to_def_id(), &mir) {
+        if let Err((span, err)) = is_min_const_fn(cx.tcx, &mir) {
             if rustc_mir::const_eval::is_min_const_fn(cx.tcx, def_id.to_def_id()) {
                 cx.tcx.sess.span_err(span, &err);
             }
diff --git a/src/tools/clippy/clippy_lints/src/redundant_clone.rs b/src/tools/clippy/clippy_lints/src/redundant_clone.rs
index 4d20a819804..b4502c668dc 100644
--- a/src/tools/clippy/clippy_lints/src/redundant_clone.rs
+++ b/src/tools/clippy/clippy_lints/src/redundant_clone.rs
@@ -86,7 +86,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantClone {
         let mir = cx.tcx.optimized_mir(def_id.to_def_id());
 
         let maybe_storage_live_result = MaybeStorageLive
-            .into_engine(cx.tcx, mir, def_id.to_def_id())
+            .into_engine(cx.tcx, mir)
             .pass_name("redundant_clone")
             .iterate_to_fixpoint()
             .into_results_cursor(mir);
diff --git a/src/tools/clippy/clippy_lints/src/utils/qualify_min_const_fn.rs b/src/tools/clippy/clippy_lints/src/utils/qualify_min_const_fn.rs
index 6809b1fa88d..19d890b4554 100644
--- a/src/tools/clippy/clippy_lints/src/utils/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/qualify_min_const_fn.rs
@@ -10,7 +10,8 @@ use std::borrow::Cow;
 
 type McfResult = Result<(), (Span, Cow<'static, str>)>;
 
-pub fn is_min_const_fn(tcx: TyCtxt<'tcx>, def_id: DefId, body: &'a Body<'tcx>) -> McfResult {
+pub fn is_min_const_fn(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>) -> McfResult {
+    let def_id = body.source.def_id();
     let mut current = def_id;
     loop {
         let predicates = tcx.predicates_of(current);