Revert "Rollup merge of rust-lang#136274 - compiler-errors:sized-wf, r=lcnr"

This reverts commit a8ecb79, reversing
changes made to 40c4e05.

Author: compiler-errors

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1110,7 +1110,6 @@ fn check_associated_item(
                 let ty = tcx.type_of(item.def_id).instantiate_identity();
                 let ty = wfcx.normalize(span, Some(WellFormedLoc::Ty(item_id)), ty);
                 wfcx.register_wf_obligation(span, loc, ty.into());
-                check_sized_if_body(wfcx, item.def_id.expect_local(), ty, Some(span));
                 Ok(())
             }
             ty::AssocKind::Fn => {
@@ -1235,7 +1234,7 @@ fn check_type_defn<'tcx>(
                     ),
                     wfcx.param_env,
                     ty,
-                    tcx.require_lang_item(LangItem::Sized, Some(hir_ty.span)),
+                    tcx.require_lang_item(LangItem::Sized, None),
                 );
             }
 
@@ -1360,7 +1359,7 @@ fn check_item_type(
                 ),
                 wfcx.param_env,
                 item_ty,
-                tcx.require_lang_item(LangItem::Sized, Some(ty_span)),
+                tcx.require_lang_item(LangItem::Sized, None),
             );
         }
 
@@ -1690,36 +1689,6 @@ fn check_fn_or_method<'tcx>(
             );
         }
     }
-
-    // If the function has a body, additionally require that the return type is sized.
-    check_sized_if_body(
-        wfcx,
-        def_id,
-        sig.output(),
-        match hir_decl.output {
-            hir::FnRetTy::Return(ty) => Some(ty.span),
-            hir::FnRetTy::DefaultReturn(_) => None,
-        },
-    );
-}
-
-fn check_sized_if_body<'tcx>(
-    wfcx: &WfCheckingCtxt<'_, 'tcx>,
-    def_id: LocalDefId,
-    ty: Ty<'tcx>,
-    maybe_span: Option<Span>,
-) {
-    let tcx = wfcx.tcx();
-    if let Some(body) = tcx.hir().maybe_body_owned_by(def_id) {
-        let span = maybe_span.unwrap_or(body.value.span);
-
-        wfcx.register_bound(
-            ObligationCause::new(span, def_id, traits::ObligationCauseCode::SizedReturnType),
-            wfcx.param_env,
-            ty,
-            tcx.require_lang_item(LangItem::Sized, Some(span)),
-        );
-    }
 }
 
 /// The `arbitrary_self_types_pointers` feature implies `arbitrary_self_types`.

compiler/rustc_hir_typeck/src/check.rs

@@ -117,17 +117,22 @@ pub(super) fn check_fn<'a, 'tcx>(
 
     fcx.typeck_results.borrow_mut().liberated_fn_sigs_mut().insert(fn_id, fn_sig);
 
-    // We checked the root's ret ty during wfcheck, but not the child.
-    if fcx.tcx.is_typeck_child(fn_def_id.to_def_id()) {
-        let return_or_body_span = match decl.output {
-            hir::FnRetTy::DefaultReturn(_) => body.value.span,
-            hir::FnRetTy::Return(ty) => ty.span,
-        };
+    let return_or_body_span = match decl.output {
+        hir::FnRetTy::DefaultReturn(_) => body.value.span,
+        hir::FnRetTy::Return(ty) => ty.span,
+    };
 
+    fcx.require_type_is_sized(
+        declared_ret_ty,
+        return_or_body_span,
+        ObligationCauseCode::SizedReturnType,
+    );
+    // We checked the root's signature during wfcheck, but not the child.
+    if fcx.tcx.is_typeck_child(fn_def_id.to_def_id()) {
         fcx.require_type_is_sized(
             declared_ret_ty,
             return_or_body_span,
-            ObligationCauseCode::SizedReturnType,
+            ObligationCauseCode::WellFormed(None),
         );
     }