Rollup of 14 pull requests

compiler/rustc_ast_lowering/src/asm.rs

@@ -93,7 +93,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 match asm::InlineAsmClobberAbi::parse(
                     asm_arch,
                     &self.tcx.sess.target,
-                    &self.tcx.sess.unstable_target_features,
+                    &self.tcx.sess.internal_target_features,
                     *abi_name,
                 ) {
                     Ok(abi) => {

compiler/rustc_ast_lowering/src/delegation/generics.rs

@@ -662,10 +662,10 @@ impl<'hir> LoweringContext<'_, 'hir> {
             p.def_id.to_def_id(),
         );
 
-        self.create_resolved_path(res, p.name.ident(), p.span)
+        self.create_resolved_qpath(res, p.name.ident(), p.span)
     }
 
-    pub(super) fn create_resolved_path(
+    pub(super) fn create_resolved_qpath(
         &mut self,
         res: Res,
         ident: Ident,

compiler/rustc_ast_lowering/src/delegation/mod.rs

@@ -439,7 +439,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             };
 
             let ident = Ident::new(kw::SelfUpper, span);
-            let path = self.create_resolved_path(res, ident, span);
+            let path = self.create_resolved_qpath(res, ident, span);
 
             // FIXME(fn_delegation): add default `..` for all other fields.
             let initializer = hir::ExprKind::Struct(
@@ -454,7 +454,14 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 hir::StructTailExpr::None,
             );
 
-            self.arena.alloc(self.mk_expr(initializer, span))
+            let expr = self.mk_expr(initializer, span);
+
+            let path = self.make_lang_item_qpath(hir::LangItem::FromFn, span, None);
+            let path = self.arena.alloc(self.mk_expr(hir::ExprKind::Path(path), span));
+
+            let call = hir::ExprKind::Call(path, self.arena.alloc_slice(&[expr]));
+
+            self.arena.alloc(self.mk_expr(call, span))
         } else {
             self.arena.alloc(call)
         };

compiler/rustc_ast_lowering/src/delegation/resolution.rs

@@ -5,10 +5,10 @@ use hir::def::DefKind;
 use rustc_ast::{self as ast, Delegation, DelegationSource, NodeId};
 use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
 use rustc_hir as hir;
-use rustc_middle::ty::Ty;
+use rustc_middle::ty::{Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
 use rustc_middle::{span_bug, ty};
 use rustc_span::def_id::{DefId, LocalDefId};
-use rustc_span::{ErrorGuaranteed, Span, kw};
+use rustc_span::{ErrorGuaranteed, Span};
 
 use crate::delegation::generics::GenericsGenerationResults;
 use crate::delegation::resolution::resolver::DelegationResolver;
@@ -31,7 +31,7 @@ pub(super) struct ParamInfo {
     pub splatted: Option<u8>,
 }
 
-#[derive(Default)]
+#[derive(Default, Debug)]
 pub(super) struct SigMapping {
     pub map_return: bool,
     pub arguments_to_map: FxIndexSet<usize>,
@@ -254,17 +254,52 @@ impl<'tcx> DelegationResolver<'_, 'tcx> {
         }
 
         if self.can_perform_self_mapping(delegation, parent)? {
-            // FIXME(fn_delegation): support heuristics for mapping of complex
-            // return types: `Self` -> `Box<Arc<Rc<Self>>>`
-            mapping.map_return = sig.output().is_param(0);
+            /// Finds `Self` generic param only in ADT or references, so we avoid cases like
+            /// `Self::Item` which will return true if `output.contains(...)` will be used.
+            struct SelfFinder;
+
+            impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for SelfFinder {
+                type Result = ControlFlow<()>;
+
+                fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
+                    match t.kind() {
+                        ty::Adt(_, args) => {
+                            if args
+                                .iter()
+                                .flat_map(|arg| arg.as_type())
+                                .any(|type_arg| type_arg.is_self_param())
+                            {
+                                return ControlFlow::Break(());
+                            }
+
+                            t.super_visit_with(self)
+                        }
+                        ty::Ref(_, ref_t, _) => {
+                            if ref_t.is_self_param() {
+                                return ControlFlow::Break(());
+                            }
+
+                            t.super_visit_with(self)
+                        }
+                        _ => ControlFlow::Continue(()),
+                    }
+                }
+            }
+
+            impl SelfFinder {
+                fn contains_self(t: Ty<'_>) -> bool {
+                    t.is_self_param() || t.visit_with(&mut SelfFinder).is_break()
+                }
+            }
+
+            mapping.map_return = SelfFinder::contains_self(sig.output());
 
-            let self_param = Ty::new_param(self.tcx(), 0, kw::SelfUpper);
             let arguments_to_map = sig
                 .inputs()
                 .iter()
                 .enumerate()
                 .skip(1) // Already checked above.
-                .filter_map(|(idx, param)| param.contains(self_param).then_some(idx));
+                .filter_map(|(idx, &param)| SelfFinder::contains_self(param).then_some(idx));
 
             mapping.arguments_to_map.extend(arguments_to_map);
         }