Make body_owned_by return the body directly.

Almost all callers want this anyway, and now we can use it to also return fed bodies

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -399,8 +399,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             }
         }
         let hir = self.infcx.tcx.hir();
-        if let Some(body_id) = hir.maybe_body_owned_by(self.mir_def_id()) {
-            let expr = hir.body(body_id).value;
+        if let Some(body) = hir.maybe_body_owned_by(self.mir_def_id()) {
+            let expr = body.value;
             let place = &self.move_data.move_paths[mpi].place;
             let span = place.as_local().map(|local| self.body.local_decls[local].source_info.span);
             let mut finder = ExpressionFinder {
@@ -556,11 +556,10 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         // We use the statements were the binding was initialized, and inspect the HIR to look
         // for the branching codepaths that aren't covered, to point at them.
         let map = self.infcx.tcx.hir();
-        let body_id = map.body_owned_by(self.mir_def_id());
-        let body = map.body(body_id);
+        let body = map.body_owned_by(self.mir_def_id());
 
         let mut visitor = ConditionVisitor { spans: &spans, name: &name, errors: vec![] };
-        visitor.visit_body(body);
+        visitor.visit_body(&body);
 
         let mut show_assign_sugg = false;
         let isnt_initialized = if let InitializationRequiringAction::PartialAssignment
@@ -665,7 +664,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             }
 
             let mut visitor = LetVisitor { decl_span, sugg_span: None };
-            visitor.visit_body(body);
+            visitor.visit_body(&body);
             if let Some(span) = visitor.sugg_span {
                 self.suggest_assign_value(&mut err, moved_place, span);
             }

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -647,16 +647,15 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             let hir_map = self.infcx.tcx.hir();
             let def_id = self.body.source.def_id();
             let Some(local_def_id) = def_id.as_local() else { return };
-            let Some(body_id) = hir_map.maybe_body_owned_by(local_def_id) else { return };
-            let body = self.infcx.tcx.hir().body(body_id);
+            let Some(body) = hir_map.maybe_body_owned_by(local_def_id) else { return };
 
             let mut v = SuggestIndexOperatorAlternativeVisitor {
                 assign_span: span,
                 err,
                 ty,
                 suggested: false,
             };
-            v.visit_body(body);
+            v.visit_body(&body);
             if !v.suggested {
                 err.help(format!(
                     "to modify a `{ty}`, use `.get_mut()`, `.insert()` or the entry API",
@@ -746,9 +745,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         // `fn foo(&x: &i32)` -> `fn foo(&(mut x): &i32)`
         let def_id = self.body.source.def_id();
         if let Some(local_def_id) = def_id.as_local()
-            && let Some(body_id) = self.infcx.tcx.hir().maybe_body_owned_by(local_def_id)
-            && let body = self.infcx.tcx.hir().body(body_id)
-            && let Some(hir_id) = (BindingFinder { span: pat_span }).visit_body(body).break_value()
+            && let Some(body) = self.infcx.tcx.hir().maybe_body_owned_by(local_def_id)
+            && let Some(hir_id) = (BindingFinder { span: pat_span }).visit_body(&body).break_value()
             && let node = self.infcx.tcx.hir_node(hir_id)
             && let hir::Node::LetStmt(hir::LetStmt {
                 pat: hir::Pat { kind: hir::PatKind::Ref(_, _), .. },
@@ -867,8 +865,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 }
             }
         }
-        if let Some(body_id) = hir_map.maybe_body_owned_by(self.mir_def_id())
-            && let Block(block, _) = hir_map.body(body_id).value.kind
+        if let Some(body) = hir_map.maybe_body_owned_by(self.mir_def_id())
+            && let Block(block, _) = body.value.kind
         {
             // `span` corresponds to the expression being iterated, find the `for`-loop desugared
             // expression with that span in order to identify potential fixes when encountering a
@@ -1189,10 +1187,9 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             Some((false, err_label_span, message, _)) => {
                 let def_id = self.body.source.def_id();
                 let hir_id = if let Some(local_def_id) = def_id.as_local()
-                    && let Some(body_id) = self.infcx.tcx.hir().maybe_body_owned_by(local_def_id)
+                    && let Some(body) = self.infcx.tcx.hir().maybe_body_owned_by(local_def_id)
                 {
-                    let body = self.infcx.tcx.hir().body(body_id);
-                    BindingFinder { span: err_label_span }.visit_body(body).break_value()
+                    BindingFinder { span: err_label_span }.visit_body(&body).break_value()
                 } else {
                     None
                 };

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -1183,8 +1183,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn suggest_move_on_borrowing_closure(&self, diag: &mut Diag<'_>) {
         let map = self.infcx.tcx.hir();
-        let body_id = map.body_owned_by(self.mir_def_id());
-        let expr = &map.body(body_id).value.peel_blocks();
+        let body = map.body_owned_by(self.mir_def_id());
+        let expr = &body.value.peel_blocks();
         let mut closure_span = None::<rustc_span::Span>;
         match expr.kind {
             hir::ExprKind::MethodCall(.., args, _) => {

compiler/rustc_driver_impl/src/pretty.rs

@@ -169,7 +169,7 @@ impl<'tcx> pprust_hir::PpAnn for HirTypedAnn<'tcx> {
                 self.tcx
                     .hir()
                     .maybe_body_owned_by(expr.hir_id.owner.def_id)
-                    .map(|body_id| self.tcx.typeck_body(body_id))
+                    .map(|body_id| self.tcx.typeck_body(body_id.id()))
             });
 
             if let Some(typeck_results) = typeck_results {

compiler/rustc_hir_analysis/src/check/region.rs

@@ -896,7 +896,7 @@ pub fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
         return tcx.region_scope_tree(typeck_root_def_id);
     }
 
-    let scope_tree = if let Some(body_id) = tcx.hir().maybe_body_owned_by(def_id.expect_local()) {
+    let scope_tree = if let Some(body) = tcx.hir().maybe_body_owned_by(def_id.expect_local()) {
         let mut visitor = RegionResolutionVisitor {
             tcx,
             scope_tree: ScopeTree::default(),
@@ -907,9 +907,8 @@ pub fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
             fixup_scopes: vec![],
         };
 
-        let body = tcx.hir().body(body_id);
         visitor.scope_tree.root_body = Some(body.value.hir_id);
-        visitor.visit_body(body);
+        visitor.visit_body(&body);
         visitor.scope_tree
     } else {
         ScopeTree::default()

compiler/rustc_hir_typeck/src/_match.rs

@@ -207,10 +207,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let hir = self.tcx.hir();
 
         // First, check that we're actually in the tail of a function.
-        let Some(body_id) = hir.maybe_body_owned_by(self.body_id) else {
+        let Some(body) = hir.maybe_body_owned_by(self.body_id) else {
             return;
         };
-        let body = hir.body(body_id);
         let hir::ExprKind::Block(block, _) = body.value.kind else {
             return;
         };

compiler/rustc_hir_typeck/src/demand.rs

@@ -327,8 +327,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         let mut expr_finder = FindExprs { hir_id: local_hir_id, uses: init.into_iter().collect() };
-        let body =
-            hir.body(hir.maybe_body_owned_by(self.body_id).expect("expected item to have body"));
+        let body = hir.body_owned_by(self.body_id);
         expr_finder.visit_expr(body.value);
 
         // Replaces all of the variables in the given type with a fresh inference variable.

compiler/rustc_hir_typeck/src/expr.rs

@@ -909,8 +909,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // the first place.
             assert_ne!(encl_item_id.def_id, encl_body_owner_id);
 
-            let encl_body_id = self.tcx.hir().body_owned_by(encl_body_owner_id);
-            let encl_body = self.tcx.hir().body(encl_body_id);
+            let encl_body = self.tcx.hir().body_owned_by(encl_body_owner_id);
 
             err.encl_body_span = Some(encl_body.value.span);
             err.encl_fn_span = Some(*encl_fn_span);

compiler/rustc_hir_typeck/src/fallback.rs

@@ -544,9 +544,8 @@ fn compute_unsafe_infer_vars<'a, 'tcx>(
     root_ctxt: &'a TypeckRootCtxt<'tcx>,
     body_id: LocalDefId,
 ) -> UnordMap<ty::TyVid, (HirId, Span, UnsafeUseReason)> {
-    let body_id =
+    let body =
         root_ctxt.tcx.hir().maybe_body_owned_by(body_id).expect("body id must have an owner");
-    let body = root_ctxt.tcx.hir().body(body_id);
     let mut res = UnordMap::default();
 
     struct UnsafeInferVarsVisitor<'a, 'tcx, 'r> {

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -1973,8 +1973,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             *expr
         } else {
             let body_def_id = hir.enclosing_body_owner(expr.hir_id);
-            let body_id = hir.body_owned_by(body_def_id);
-            let body = hir.body(body_id);
+            let body = hir.body_owned_by(body_def_id);
 
             // Get tail expr of the body
             match body.value.kind {

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -505,9 +505,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             && let hir::def::Res::Local(recv_id) = path.res
             && let Some(segment) = path.segments.first()
         {
-            let map = self.infcx.tcx.hir();
-            let body_id = self.tcx.hir().body_owned_by(self.body_id);
-            let body = map.body(body_id);
+            let body = self.tcx.hir().body_owned_by(self.body_id);
 
             if let Node::Expr(call_expr) = self.tcx.parent_hir_node(rcvr.hir_id) {
                 let mut let_visitor = LetVisitor {
@@ -518,7 +516,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     method_name,
                     sugg_let: None,
                 };
-                let_visitor.visit_body(body);
+                let_visitor.visit_body(&body);
                 if let Some(sugg_let) = let_visitor.sugg_let
                     && let Some(self_ty) = self.node_ty_opt(sugg_let.init_hir_id)
                 {
@@ -2429,9 +2427,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             seg1.ident.span,
             StashKey::CallAssocMethod,
             |err| {
-                let map = self.infcx.tcx.hir();
-                let body_id = self.tcx.hir().body_owned_by(self.body_id);
-                let body = map.body(body_id);
+                let body = self.tcx.hir().body_owned_by(self.body_id);
                 struct LetVisitor {
                     ident_name: Symbol,
                 }
@@ -2453,7 +2449,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                 if let Node::Expr(call_expr) = self.tcx.parent_hir_node(seg1.hir_id)
                     && let ControlFlow::Break(Some(expr)) =
-                        (LetVisitor { ident_name: seg1.ident.name }).visit_body(body)
+                        (LetVisitor { ident_name: seg1.ident.name }).visit_body(&body)
                     && let Some(self_ty) = self.node_ty_opt(expr.hir_id)
                 {
                     let probe = self.lookup_probe_for_diagnostic(

compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs

@@ -457,10 +457,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         };
 
         let mut local_visitor = FindInferSourceVisitor::new(self, typeck_results, arg);
-        if let Some(body_id) = self.tcx.hir().maybe_body_owned_by(
+        if let Some(body) = self.tcx.hir().maybe_body_owned_by(
             self.tcx.typeck_root_def_id(body_def_id.to_def_id()).expect_local(),
         ) {
-            let expr = self.tcx.hir().body(body_id).value;
+            let expr = body.value;
             local_visitor.visit_expr(expr);
         }
 

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs

@@ -62,14 +62,13 @@ pub fn find_param_with_region<'tcx>(
         _ => {}
     }
 
-    let body_id = hir.maybe_body_owned_by(def_id)?;
+    let body = hir.maybe_body_owned_by(def_id)?;
 
-    let owner_id = hir.body_owner(body_id);
+    let owner_id = hir.body_owner(body.id());
     let fn_decl = hir.fn_decl_by_hir_id(owner_id)?;
     let poly_fn_sig = tcx.fn_sig(id).instantiate_identity();
 
     let fn_sig = tcx.liberate_late_bound_regions(id, poly_fn_sig);
-    let body = hir.body(body_id);
     body.params
         .iter()
         .take(if fn_sig.c_variadic {

compiler/rustc_infer/src/infer/error_reporting/suggest.rs

@@ -580,10 +580,9 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
         }
 
-        self.tcx.hir().maybe_body_owned_by(cause.body_id).and_then(|body_id| {
-            let body = self.tcx.hir().body(body_id);
+        self.tcx.hir().maybe_body_owned_by(cause.body_id).and_then(|body| {
             IfVisitor { err_span: span, found_if: false }
-                .visit_body(body)
+                .visit_body(&body)
                 .is_break()
                 .then(|| TypeErrorAdditionalDiags::AddLetForLetChains { span: span.shrink_to_lo() })
         })

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1677,9 +1677,9 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 if should_encode_const(tcx.def_kind(def_id)) {
                     let qualifs = tcx.mir_const_qualif(def_id);
                     record!(self.tables.mir_const_qualif[def_id.to_def_id()] <- qualifs);
-                    let body_id = tcx.hir().maybe_body_owned_by(def_id);
-                    if let Some(body_id) = body_id {
-                        let const_data = rendered_const(self.tcx, body_id);
+                    let body = tcx.hir().maybe_body_owned_by(def_id);
+                    if let Some(body) = body {
+                        let const_data = rendered_const(self.tcx, &body, def_id);
                         record!(self.tables.rendered_const[def_id.to_def_id()] <- const_data);
                     }
                 }
@@ -2368,9 +2368,9 @@ pub fn provide(providers: &mut Providers) {
 /// Whenever possible, prefer to evaluate the constant first and try to
 /// use a different method for pretty-printing. Ideally this function
 /// should only ever be used as a fallback.
-pub fn rendered_const<'tcx>(tcx: TyCtxt<'tcx>, body: hir::BodyId) -> String {
+pub fn rendered_const<'tcx>(tcx: TyCtxt<'tcx>, body: &hir::Body<'_>, def_id: LocalDefId) -> String {
     let hir = tcx.hir();
-    let value = &hir.body(body).value;
+    let value = body.value;
 
     #[derive(PartialEq, Eq)]
     enum Classification {
@@ -2426,13 +2426,13 @@ pub fn rendered_const<'tcx>(tcx: TyCtxt<'tcx>, body: hir::BodyId) -> String {
 
         // Otherwise we prefer pretty-printing to get rid of extraneous whitespace, comments and
         // other formatting artifacts.
-        Literal | Simple => id_to_string(&hir, body.hir_id),
+        Literal | Simple => id_to_string(&hir, body.id().hir_id),
 
         // FIXME: Omit the curly braces if the enclosing expression is an array literal
         //        with a repeated element (an `ExprKind::Repeat`) as in such case it
         //        would not actually need any disambiguation.
         Complex => {
-            if tcx.def_kind(hir.body_owner_def_id(body).to_def_id()) == DefKind::AnonConst {
+            if tcx.def_kind(def_id) == DefKind::AnonConst {
                 "{ _ }".to_owned()
             } else {
                 "_".to_owned()

compiler/rustc_middle/src/hir/map/mod.rs

@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use crate::hir::ModuleItems;
 use crate::middle::debugger_visualizer::DebuggerVisualizerFile;
 use crate::query::LocalCrate;
@@ -254,13 +256,26 @@ impl<'hir> Map<'hir> {
 
     /// Given a `LocalDefId`, returns the `BodyId` associated with it,
     /// if the node is a body owner, otherwise returns `None`.
-    pub fn maybe_body_owned_by(self, id: LocalDefId) -> Option<BodyId> {
-        self.tcx.hir_node_by_def_id(id).body_id()
+    pub fn maybe_body_owned_by(self, id: LocalDefId) -> Option<Cow<'hir, Body<'hir>>> {
+        Some(match self.tcx.def_kind(id) {
+            // Inline consts do not have bodies of their own, so create one to make the follow-up logic simpler.
+            DefKind::InlineConst => {
+                let e = self.expect_expr(self.tcx.local_def_id_to_hir_id(id));
+                Cow::Owned(Body {
+                    params: &[],
+                    value: match e.kind {
+                        ExprKind::ConstBlock(body) => body,
+                        _ => span_bug!(e.span, "InlineConst was not a ConstBlock: {e:#?}"),
+                    },
+                })
+            }
+            _ => Cow::Borrowed(self.body(self.tcx.hir_node_by_def_id(id).body_id()?)),
+        })
     }
 
     /// Given a body owner's id, returns the `BodyId` associated with it.
     #[track_caller]
-    pub fn body_owned_by(self, id: LocalDefId) -> BodyId {
+    pub fn body_owned_by(self, id: LocalDefId) -> Cow<'hir, Body<'hir>> {
         self.maybe_body_owned_by(id).unwrap_or_else(|| {
             let hir_id = self.tcx.local_def_id_to_hir_id(id);
             span_bug!(

compiler/rustc_middle/src/hir/mod.rs

@@ -194,8 +194,7 @@ pub fn provide(providers: &mut Providers) {
     };
     providers.fn_arg_names = |tcx, def_id| {
         let hir = tcx.hir();
-        let hir_id = tcx.local_def_id_to_hir_id(def_id);
-        if let Some(body_id) = hir.maybe_body_owned_by(def_id) {
+        if let Some(body_id) = tcx.hir_node_by_def_id(def_id).body_id() {
             tcx.arena.alloc_from_iter(hir.body_param_names(body_id))
         } else if let Node::TraitItem(&TraitItem {
             kind: TraitItemKind::Fn(_, TraitFn::Required(idents)),
@@ -204,11 +203,15 @@ pub fn provide(providers: &mut Providers) {
         | Node::ForeignItem(&ForeignItem {
             kind: ForeignItemKind::Fn(_, idents, _),
             ..
-        }) = tcx.hir_node(hir_id)
+        }) = tcx.hir_node(tcx.local_def_id_to_hir_id(def_id))
         {
             idents
         } else {
-            span_bug!(hir.span(hir_id), "fn_arg_names: unexpected item {:?}", def_id);
+            span_bug!(
+                hir.span(tcx.local_def_id_to_hir_id(def_id)),
+                "fn_arg_names: unexpected item {:?}",
+                def_id
+            );
         }
     };
     providers.all_local_trait_impls = |tcx, ()| &tcx.resolutions(()).trait_impls;

compiler/rustc_mir_build/src/build/mod.rs

@@ -452,7 +452,7 @@ fn construct_fn<'tcx>(
     assert_eq!(expr.as_usize(), thir.exprs.len() - 1);
 
     // Figure out what primary body this item has.
-    let body_id = tcx.hir().body_owned_by(fn_def);
+    let body = tcx.hir().body_owned_by(fn_def);
     let span_with_body = tcx.hir().span_with_body(fn_id);
     let return_ty_span = tcx
         .hir()
@@ -512,9 +512,9 @@ fn construct_fn<'tcx>(
     );
 
     let call_site_scope =
-        region::Scope { id: body_id.hir_id.local_id, data: region::ScopeData::CallSite };
+        region::Scope { id: body.id().hir_id.local_id, data: region::ScopeData::CallSite };
     let arg_scope =
-        region::Scope { id: body_id.hir_id.local_id, data: region::ScopeData::Arguments };
+        region::Scope { id: body.id().hir_id.local_id, data: region::ScopeData::Arguments };
     let source_info = builder.source_info(span);
     let call_site_s = (call_site_scope, source_info);
     unpack!(builder.in_scope(call_site_s, LintLevel::Inherited, |builder| {