Store impl_trait_fn inside OpaqueTyOrigin.

Author: cjgillot

compiler/rustc_ast_lowering/src/item.rs

@@ -247,12 +247,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         AnonymousLifetimeMode::PassThrough,
                         |this, idty| {
                             let ret_id = asyncness.opt_return_id();
-                            this.lower_fn_decl(
-                                &decl,
-                                Some((fn_def_id.to_def_id(), idty)),
-                                true,
-                                ret_id,
-                            )
+                            this.lower_fn_decl(&decl, Some((fn_def_id, idty)), true, ret_id)
                         },
                     );
                     let sig = hir::FnSig {
@@ -1264,7 +1259,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             |this, idty| {
                 this.lower_fn_decl(
                     &sig.decl,
-                    Some((fn_def_id.to_def_id(), idty)),
+                    Some((fn_def_id, idty)),
                     impl_trait_return_allow,
                     is_async,
                 )

compiler/rustc_ast_lowering/src/lib.rs

@@ -228,7 +228,7 @@ enum ImplTraitContext<'b, 'a> {
     ReturnPositionOpaqueTy {
         /// `DefId` for the parent function, used to look up necessary
         /// information later.
-        fn_def_id: DefId,
+        fn_def_id: LocalDefId,
         /// Origin: Either OpaqueTyOrigin::FnReturn or OpaqueTyOrigin::AsyncFn,
         origin: hir::OpaqueTyOrigin,
     },
@@ -1377,7 +1377,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn lower_opaque_impl_trait(
         &mut self,
         span: Span,
-        fn_def_id: Option<DefId>,
+        fn_def_id: Option<LocalDefId>,
         origin: hir::OpaqueTyOrigin,
         opaque_ty_node_id: NodeId,
         capturable_lifetimes: Option<&FxHashSet<hir::LifetimeName>>,
@@ -1449,7 +1449,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     span: lctx.lower_span(span),
                 },
                 bounds: hir_bounds,
-                impl_trait_fn: fn_def_id,
                 origin,
             };
 
@@ -1519,7 +1518,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn lower_fn_decl(
         &mut self,
         decl: &FnDecl,
-        mut in_band_ty_params: Option<(DefId, &mut Vec<hir::GenericParam<'hir>>)>,
+        mut in_band_ty_params: Option<(LocalDefId, &mut Vec<hir::GenericParam<'hir>>)>,
         impl_trait_return_allow: bool,
         make_ret_async: Option<NodeId>,
     ) -> &'hir hir::FnDecl<'hir> {
@@ -1577,7 +1576,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         Some((def_id, _)) if impl_trait_return_allow => {
                             ImplTraitContext::ReturnPositionOpaqueTy {
                                 fn_def_id: def_id,
-                                origin: hir::OpaqueTyOrigin::FnReturn,
+                                origin: hir::OpaqueTyOrigin::FnReturn(def_id),
                             }
                         }
                         _ => ImplTraitContext::disallowed(),
@@ -1632,7 +1631,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn lower_async_fn_ret_ty(
         &mut self,
         output: &FnRetTy,
-        fn_def_id: DefId,
+        fn_def_id: LocalDefId,
         opaque_ty_node_id: NodeId,
     ) -> hir::FnRetTy<'hir> {
         debug!(
@@ -1747,8 +1746,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     span: this.lower_span(span),
                 },
                 bounds: arena_vec![this; future_bound],
-                impl_trait_fn: Some(fn_def_id),
-                origin: hir::OpaqueTyOrigin::AsyncFn,
+                origin: hir::OpaqueTyOrigin::AsyncFn(fn_def_id),
             };
 
             trace!("exist ty from async fn def id: {:#?}", opaque_ty_def_id);
@@ -1794,7 +1792,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn lower_async_fn_output_type_to_future_bound(
         &mut self,
         output: &FnRetTy,
-        fn_def_id: DefId,
+        fn_def_id: LocalDefId,
         span: Span,
     ) -> hir::GenericBound<'hir> {
         // Compute the `T` in `Future<Output = T>` from the return type.
@@ -1805,7 +1803,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 // generates.
                 let context = ImplTraitContext::ReturnPositionOpaqueTy {
                     fn_def_id,
-                    origin: hir::OpaqueTyOrigin::FnReturn,
+                    origin: hir::OpaqueTyOrigin::FnReturn(fn_def_id),
                 };
                 self.lower_ty(ty, context)
             }
@@ -2442,17 +2440,12 @@ impl<'hir> GenericArgsCtor<'hir> {
     }
 }
 
+#[tracing::instrument(level = "debug")]
 fn lifetimes_from_impl_trait_bounds(
     opaque_ty_id: NodeId,
     bounds: hir::GenericBounds<'_>,
     lifetimes_to_include: Option<&FxHashSet<hir::LifetimeName>>,
 ) -> Vec<(hir::LifetimeName, Span)> {
-    debug!(
-        "lifetimes_from_impl_trait_bounds(opaque_ty_id={:?}, \
-             bounds={:#?})",
-        opaque_ty_id, bounds,
-    );
-
     // This visitor walks over `impl Trait` bounds and creates defs for all lifetimes that
     // appear in the bounds, excluding lifetimes that are created within the bounds.
     // E.g., `'a`, `'b`, but not `'c` in `impl for<'c> SomeTrait<'a, 'b, 'c>`.

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -173,7 +173,7 @@ fn check_opaque_type_parameter_valid(
         // fn foo<l0..'ln>() -> foo::<'static..'static>::Foo<'l0..'lm>.
         //
         // which would error here on all of the `'static` args.
-        OpaqueTyOrigin::FnReturn | OpaqueTyOrigin::AsyncFn => return true,
+        OpaqueTyOrigin::FnReturn(..) | OpaqueTyOrigin::AsyncFn(..) => return true,
         // Check these
         OpaqueTyOrigin::TyAlias => {}
     }

compiler/rustc_hir/src/hir.rs

@@ -2248,17 +2248,16 @@ pub struct BareFnTy<'hir> {
 pub struct OpaqueTy<'hir> {
     pub generics: Generics<'hir>,
     pub bounds: GenericBounds<'hir>,
-    pub impl_trait_fn: Option<DefId>,
     pub origin: OpaqueTyOrigin,
 }
 
 /// From whence the opaque type came.
 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub enum OpaqueTyOrigin {
     /// `-> impl Trait`
-    FnReturn,
+    FnReturn(LocalDefId),
     /// `async fn`
-    AsyncFn,
+    AsyncFn(LocalDefId),
     /// type aliases: `type Foo = impl Trait;`
     TyAlias,
 }
@@ -2809,7 +2808,9 @@ impl ItemKind<'_> {
         Some(match *self {
             ItemKind::Fn(_, ref generics, _)
             | ItemKind::TyAlias(_, ref generics)
-            | ItemKind::OpaqueTy(OpaqueTy { ref generics, impl_trait_fn: None, .. })
+            | ItemKind::OpaqueTy(OpaqueTy {
+                ref generics, origin: OpaqueTyOrigin::TyAlias, ..
+            })
             | ItemKind::Enum(_, ref generics)
             | ItemKind::Struct(_, ref generics)
             | ItemKind::Union(_, ref generics)

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

@@ -107,7 +107,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                         kind:
                             hir::ItemKind::OpaqueTy(hir::OpaqueTy {
                                 bounds,
-                                origin: hir::OpaqueTyOrigin::AsyncFn,
+                                origin: hir::OpaqueTyOrigin::AsyncFn(..),
                                 ..
                             }),
                         ..

compiler/rustc_infer/src/infer/opaque_types.rs

@@ -276,7 +276,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         debug!(?concrete_ty);
 
         let first_own_region = match opaque_defn.origin {
-            hir::OpaqueTyOrigin::FnReturn | hir::OpaqueTyOrigin::AsyncFn => {
+            hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..) => {
                 // We lower
                 //
                 // fn foo<'l0..'ln>() -> impl Trait<'l0..'lm>
@@ -463,20 +463,24 @@ impl<'a, 'tcx> Instantiator<'a, 'tcx> {
                         let parent_def_id = self.infcx.defining_use_anchor;
                         let (in_definition_scope, origin) = match tcx.hir().expect_item(def_id).kind
                         {
+                            // Async `impl Trait`
+                            hir::ItemKind::OpaqueTy(hir::OpaqueTy {
+                                origin: hir::OpaqueTyOrigin::AsyncFn(parent),
+                                ..
+                            }) => (parent == parent_def_id, hir::OpaqueTyOrigin::AsyncFn(parent)),
                             // Anonymous `impl Trait`
                             hir::ItemKind::OpaqueTy(hir::OpaqueTy {
-                                impl_trait_fn: Some(parent),
-                                origin,
+                                origin: hir::OpaqueTyOrigin::FnReturn(parent),
                                 ..
-                            }) => (parent == parent_def_id.to_def_id(), origin),
+                            }) => (parent == parent_def_id, hir::OpaqueTyOrigin::FnReturn(parent)),
                             // Named `type Foo = impl Bar;`
                             hir::ItemKind::OpaqueTy(hir::OpaqueTy {
-                                impl_trait_fn: None,
-                                origin,
+                                origin: hir::OpaqueTyOrigin::TyAlias,
                                 ..
-                            }) => {
-                                (may_define_opaque_type(tcx, parent_def_id, opaque_hir_id), origin)
-                            }
+                            }) => (
+                                may_define_opaque_type(tcx, parent_def_id, opaque_hir_id),
+                                hir::OpaqueTyOrigin::TyAlias,
+                            ),
                             ref itemkind => {
                                 span_bug!(
                                     self.value_span,

compiler/rustc_middle/src/ty/mod.rs

@@ -2055,13 +2055,17 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
-/// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition.
-pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
-    if let Some(def_id) = def_id.as_local() {
-        if let Node::Item(item) = tcx.hir().get(tcx.hir().local_def_id_to_hir_id(def_id)) {
-            if let hir::ItemKind::OpaqueTy(ref opaque_ty) = item.kind {
-                return opaque_ty.impl_trait_fn;
-            }
+/// Yields the parent function's `LocalDefId` if `def_id` is an `impl Trait` definition.
+pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<LocalDefId> {
+    let def_id = def_id.as_local()?;
+    if let Node::Item(item) = tcx.hir().get(tcx.hir().local_def_id_to_hir_id(def_id)) {
+        if let hir::ItemKind::OpaqueTy(ref opaque_ty) = item.kind {
+            return match opaque_ty.origin {
+                hir::OpaqueTyOrigin::FnReturn(parent) | hir::OpaqueTyOrigin::AsyncFn(parent) => {
+                    Some(parent)
+                }
+                hir::OpaqueTyOrigin::TyAlias => None,
+            };
         }
     }
     None

compiler/rustc_resolve/src/late/lifetimes.rs

@@ -968,7 +968,10 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 let (generics, bounds) = match opaque_ty.kind {
                     // Named opaque `impl Trait` types are reached via `TyKind::Path`.
                     // This arm is for `impl Trait` in the types of statics, constants and locals.
-                    hir::ItemKind::OpaqueTy(hir::OpaqueTy { impl_trait_fn: None, .. }) => {
+                    hir::ItemKind::OpaqueTy(hir::OpaqueTy {
+                        origin: hir::OpaqueTyOrigin::TyAlias,
+                        ..
+                    }) => {
                         intravisit::walk_ty(self, ty);
 
                         // Elided lifetimes are not allowed in non-return
@@ -985,7 +988,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                     }
                     // RPIT (return position impl trait)
                     hir::ItemKind::OpaqueTy(hir::OpaqueTy {
-                        impl_trait_fn: Some(_),
+                        origin: hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..),
                         ref generics,
                         bounds,
                         ..
@@ -1695,7 +1698,11 @@ fn compute_object_lifetime_defaults(
         hir::ItemKind::Struct(_, ref generics)
         | hir::ItemKind::Union(_, ref generics)
         | hir::ItemKind::Enum(_, ref generics)
-        | hir::ItemKind::OpaqueTy(hir::OpaqueTy { ref generics, impl_trait_fn: None, .. })
+        | hir::ItemKind::OpaqueTy(hir::OpaqueTy {
+            ref generics,
+            origin: hir::OpaqueTyOrigin::TyAlias,
+            ..
+        })
         | hir::ItemKind::TyAlias(_, ref generics)
         | hir::ItemKind::Trait(_, _, ref generics, ..) => {
             let result = object_lifetime_defaults_for_item(tcx, generics);
@@ -2067,7 +2074,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                                     ..
                                 }) = self.tcx.hir().get(parent_hir_id)
                                 {
-                                    if opaque.origin != hir::OpaqueTyOrigin::AsyncFn {
+                                    if !matches!(opaque.origin, hir::OpaqueTyOrigin::AsyncFn(..)) {
                                         continue 'lifetimes;
                                     }
                                     // We want to do this only if the liftime identifier is already defined

compiler/rustc_ty_utils/src/ty.rs

@@ -248,7 +248,7 @@ fn trait_of_item(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
 fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
     // The param_env of an impl Trait type is its defining function's param_env
     if let Some(parent) = ty::is_impl_trait_defn(tcx, def_id) {
-        return param_env(tcx, parent);
+        return param_env(tcx, parent.to_def_id());
     }
     // Compute the bounds on Self and the type parameters.
 
@@ -313,7 +313,7 @@ fn well_formed_types_in_env<'tcx>(
 
     // The environment of an impl Trait type is its defining function's environment.
     if let Some(parent) = ty::is_impl_trait_defn(tcx, def_id) {
-        return well_formed_types_in_env(tcx, parent);
+        return well_formed_types_in_env(tcx, parent.to_def_id());
     }
 
     // Compute the bounds on `Self` and the type parameters.

compiler/rustc_typeck/src/astconv/mod.rs

@@ -2336,9 +2336,16 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 let def_id = item_id.def_id.to_def_id();
 
                 match opaque_ty.kind {
-                    hir::ItemKind::OpaqueTy(hir::OpaqueTy { impl_trait_fn, .. }) => {
-                        self.impl_trait_ty_to_ty(def_id, lifetimes, impl_trait_fn.is_some())
-                    }
+                    hir::ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) => self
+                        .impl_trait_ty_to_ty(
+                            def_id,
+                            lifetimes,
+                            matches!(
+                                origin,
+                                hir::OpaqueTyOrigin::FnReturn(..)
+                                    | hir::OpaqueTyOrigin::AsyncFn(..)
+                            ),
+                        ),
                     ref i => bug!("`impl Trait` pointed to non-opaque type?? {:#?}", i),
                 }
             }

compiler/rustc_typeck/src/check/check.rs

@@ -541,7 +541,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
     }
 
     if let ItemKind::OpaqueTy(hir::OpaqueTy {
-        origin: hir::OpaqueTyOrigin::AsyncFn | hir::OpaqueTyOrigin::FnReturn,
+        origin: hir::OpaqueTyOrigin::AsyncFn(..) | hir::OpaqueTyOrigin::FnReturn(..),
         ..
     }) = item.kind
     {
@@ -567,7 +567,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
             visitor.visit_item(&item);
             let is_async = match item.kind {
                 ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) => {
-                    matches!(origin, hir::OpaqueTyOrigin::AsyncFn)
+                    matches!(origin, hir::OpaqueTyOrigin::AsyncFn(..))
                 }
                 _ => unreachable!(),
             };
@@ -604,7 +604,7 @@ pub(super) fn check_opaque_for_cycles<'tcx>(
 ) -> Result<(), ErrorReported> {
     if tcx.try_expand_impl_trait_type(def_id.to_def_id(), substs).is_err() {
         match origin {
-            hir::OpaqueTyOrigin::AsyncFn => async_opaque_type_cycle_error(tcx, span),
+            hir::OpaqueTyOrigin::AsyncFn(..) => async_opaque_type_cycle_error(tcx, span),
             _ => opaque_type_cycle_error(tcx, def_id, span),
         }
         Err(ErrorReported)
@@ -635,7 +635,7 @@ fn check_opaque_meets_bounds<'tcx>(
 ) {
     match origin {
         // Checked when type checking the function containing them.
-        hir::OpaqueTyOrigin::FnReturn | hir::OpaqueTyOrigin::AsyncFn => return,
+        hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..) => return,
         // Can have different predicates to their defining use
         hir::OpaqueTyOrigin::TyAlias => {}
     }