Use gen blocks in the compiler instead of from_coroutine

Author: compiler-errors

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -2177,84 +2177,80 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
     /// Walk the generics of the item for a trait bound whose self type
     /// corresponds to the expected res, and return the trait def id.
     fn for_each_trait_bound_on_res(&self, expected_res: Res) -> impl Iterator<Item = DefId> {
-        std::iter::from_coroutine(
-            #[coroutine]
-            move || {
-                let mut scope = self.scope;
-                loop {
-                    let hir_id = match *scope {
-                        Scope::Binder { hir_id, .. } => Some(hir_id),
-                        Scope::Root { opt_parent_item: Some(parent_def_id) } => {
-                            Some(self.tcx.local_def_id_to_hir_id(parent_def_id))
-                        }
-                        Scope::Body { .. }
-                        | Scope::ObjectLifetimeDefault { .. }
-                        | Scope::Supertrait { .. }
-                        | Scope::TraitRefBoundary { .. }
-                        | Scope::LateBoundary { .. }
-                        | Scope::Opaque { .. }
-                        | Scope::Root { opt_parent_item: None } => None,
-                    };
+        gen move {
+            let mut scope = self.scope;
+            loop {
+                let hir_id = match *scope {
+                    Scope::Binder { hir_id, .. } => Some(hir_id),
+                    Scope::Root { opt_parent_item: Some(parent_def_id) } => {
+                        Some(self.tcx.local_def_id_to_hir_id(parent_def_id))
+                    }
+                    Scope::Body { .. }
+                    | Scope::ObjectLifetimeDefault { .. }
+                    | Scope::Supertrait { .. }
+                    | Scope::TraitRefBoundary { .. }
+                    | Scope::LateBoundary { .. }
+                    | Scope::Opaque { .. }
+                    | Scope::Root { opt_parent_item: None } => None,
+                };
 
-                    if let Some(hir_id) = hir_id {
-                        let node = self.tcx.hir_node(hir_id);
-                        // If this is a `Self` bound in a trait, yield the trait itself.
-                        // Specifically, we don't need to look at any supertraits since
-                        // we already do that in `BoundVarContext::supertrait_hrtb_vars`.
-                        if let Res::SelfTyParam { trait_: _ } = expected_res
-                            && let hir::Node::Item(item) = node
-                            && let hir::ItemKind::Trait(..) = item.kind
-                        {
-                            // Yield the trait's def id. Supertraits will be
-                            // elaborated from that.
-                            yield item.owner_id.def_id.to_def_id();
-                        } else if let Some(generics) = node.generics() {
-                            for pred in generics.predicates {
-                                let hir::WherePredicateKind::BoundPredicate(pred) = pred.kind
-                                else {
-                                    continue;
-                                };
-                                let hir::TyKind::Path(hir::QPath::Resolved(None, bounded_path)) =
-                                    pred.bounded_ty.kind
-                                else {
-                                    continue;
-                                };
-                                // Match the expected res.
-                                if bounded_path.res != expected_res {
-                                    continue;
-                                }
-                                for pred in pred.bounds {
-                                    match pred {
-                                        hir::GenericBound::Trait(poly_trait_ref) => {
-                                            if let Some(def_id) =
-                                                poly_trait_ref.trait_ref.trait_def_id()
-                                            {
-                                                yield def_id;
-                                            }
+                if let Some(hir_id) = hir_id {
+                    let node = self.tcx.hir_node(hir_id);
+                    // If this is a `Self` bound in a trait, yield the trait itself.
+                    // Specifically, we don't need to look at any supertraits since
+                    // we already do that in `BoundVarContext::supertrait_hrtb_vars`.
+                    if let Res::SelfTyParam { trait_: _ } = expected_res
+                        && let hir::Node::Item(item) = node
+                        && let hir::ItemKind::Trait(..) = item.kind
+                    {
+                        // Yield the trait's def id. Supertraits will be
+                        // elaborated from that.
+                        yield item.owner_id.def_id.to_def_id();
+                    } else if let Some(generics) = node.generics() {
+                        for pred in generics.predicates {
+                            let hir::WherePredicateKind::BoundPredicate(pred) = pred.kind else {
+                                continue;
+                            };
+                            let hir::TyKind::Path(hir::QPath::Resolved(None, bounded_path)) =
+                                pred.bounded_ty.kind
+                            else {
+                                continue;
+                            };
+                            // Match the expected res.
+                            if bounded_path.res != expected_res {
+                                continue;
+                            }
+                            for pred in pred.bounds {
+                                match pred {
+                                    hir::GenericBound::Trait(poly_trait_ref) => {
+                                        if let Some(def_id) =
+                                            poly_trait_ref.trait_ref.trait_def_id()
+                                        {
+                                            yield def_id;
                                         }
-                                        hir::GenericBound::Outlives(_)
-                                        | hir::GenericBound::Use(_, _) => {}
                                     }
+                                    hir::GenericBound::Outlives(_)
+                                    | hir::GenericBound::Use(_, _) => {}
                                 }
                             }
                         }
                     }
+                }
 
-                    match *scope {
-                        Scope::Binder { s, .. }
-                        | Scope::Body { s, .. }
-                        | Scope::ObjectLifetimeDefault { s, .. }
-                        | Scope::Supertrait { s, .. }
-                        | Scope::TraitRefBoundary { s }
-                        | Scope::LateBoundary { s, .. }
-                        | Scope::Opaque { s, .. } => {
-                            scope = s;
-                        }
-                        Scope::Root { .. } => break,
+                match *scope {
+                    Scope::Binder { s, .. }
+                    | Scope::Body { s, .. }
+                    | Scope::ObjectLifetimeDefault { s, .. }
+                    | Scope::Supertrait { s, .. }
+                    | Scope::TraitRefBoundary { s }
+                    | Scope::LateBoundary { s, .. }
+                    | Scope::Opaque { s, .. } => {
+                        scope = s;
                     }
+                    Scope::Root { .. } => break,
                 }
-            },
-        )
+            }
+        }
     }
 }
 

compiler/rustc_hir_analysis/src/lib.rs

@@ -62,8 +62,8 @@ This API is completely unstable and subject to change.
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
-#![feature(coroutines)]
 #![feature(debug_closure_helpers)]
+#![feature(gen_blocks)]
 #![feature(if_let_guard)]
 #![feature(iter_from_coroutine)]
 #![feature(iter_intersperse)]

compiler/rustc_metadata/src/lib.rs

@@ -2,10 +2,10 @@
 #![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(coroutines)]
 #![feature(decl_macro)]
 #![feature(error_iter)]
 #![feature(file_buffered)]
+#![feature(gen_blocks)]
 #![feature(if_let_guard)]
 #![feature(iter_from_coroutine)]
 #![feature(macro_metavar_expr)]

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -3,7 +3,7 @@
 use std::iter::TrustedLen;
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, OnceLock};
-use std::{io, iter, mem};
+use std::{io, mem};
 
 pub(super) use cstore_impl::provide;
 use rustc_ast as ast;
@@ -1272,34 +1272,30 @@ impl<'a> CrateMetadataRef<'a> {
         id: DefIndex,
         sess: &'a Session,
     ) -> impl Iterator<Item = ModChild> {
-        iter::from_coroutine(
-            #[coroutine]
-            move || {
-                if let Some(data) = &self.root.proc_macro_data {
-                    // If we are loading as a proc macro, we want to return
-                    // the view of this crate as a proc macro crate.
-                    if id == CRATE_DEF_INDEX {
-                        for child_index in data.macros.decode(self) {
-                            yield self.get_mod_child(child_index, sess);
-                        }
-                    }
-                } else {
-                    // Iterate over all children.
-                    let non_reexports =
-                        self.root.tables.module_children_non_reexports.get(self, id);
-                    for child_index in non_reexports.unwrap().decode(self) {
+        gen move {
+            if let Some(data) = &self.root.proc_macro_data {
+                // If we are loading as a proc macro, we want to return
+                // the view of this crate as a proc macro crate.
+                if id == CRATE_DEF_INDEX {
+                    for child_index in data.macros.decode(self) {
                         yield self.get_mod_child(child_index, sess);
                     }
+                }
+            } else {
+                // Iterate over all children.
+                let non_reexports = self.root.tables.module_children_non_reexports.get(self, id);
+                for child_index in non_reexports.unwrap().decode(self) {
+                    yield self.get_mod_child(child_index, sess);
+                }
 
-                    let reexports = self.root.tables.module_children_reexports.get(self, id);
-                    if !reexports.is_default() {
-                        for reexport in reexports.decode((self, sess)) {
-                            yield reexport;
-                        }
+                let reexports = self.root.tables.module_children_reexports.get(self, id);
+                if !reexports.is_default() {
+                    for reexport in reexports.decode((self, sess)) {
+                        yield reexport;
                     }
                 }
-            },
-        )
+            }
+        }
     }
 
     fn is_ctfe_mir_available(self, id: DefIndex) -> bool {

compiler/rustc_middle/src/lib.rs

@@ -40,12 +40,12 @@
 #![feature(box_patterns)]
 #![feature(closure_track_caller)]
 #![feature(core_intrinsics)]
-#![feature(coroutines)]
 #![feature(debug_closure_helpers)]
 #![feature(decl_macro)]
 #![feature(discriminant_kind)]
 #![feature(extern_types)]
 #![feature(file_buffered)]
+#![feature(gen_blocks)]
 #![feature(if_let_guard)]
 #![feature(intra_doc_pointers)]
 #![feature(iter_from_coroutine)]

compiler/rustc_middle/src/ty/closure.rs

@@ -422,53 +422,49 @@ pub fn analyze_coroutine_closure_captures<'a, 'tcx: 'a, T>(
     child_captures: impl IntoIterator<Item = &'a CapturedPlace<'tcx>>,
     mut for_each: impl FnMut((usize, &'a CapturedPlace<'tcx>), (usize, &'a CapturedPlace<'tcx>)) -> T,
 ) -> impl Iterator<Item = T> {
-    std::iter::from_coroutine(
-        #[coroutine]
-        move || {
-            let mut child_captures = child_captures.into_iter().enumerate().peekable();
-
-            // One parent capture may correspond to several child captures if we end up
-            // refining the set of captures via edition-2021 precise captures. We want to
-            // match up any number of child captures with one parent capture, so we keep
-            // peeking off this `Peekable` until the child doesn't match anymore.
-            for (parent_field_idx, parent_capture) in parent_captures.into_iter().enumerate() {
-                // Make sure we use every field at least once, b/c why are we capturing something
-                // if it's not used in the inner coroutine.
-                let mut field_used_at_least_once = false;
-
-                // A parent matches a child if they share the same prefix of projections.
-                // The child may have more, if it is capturing sub-fields out of
-                // something that is captured by-move in the parent closure.
-                while child_captures.peek().is_some_and(|(_, child_capture)| {
-                    child_prefix_matches_parent_projections(parent_capture, child_capture)
-                }) {
-                    let (child_field_idx, child_capture) = child_captures.next().unwrap();
-                    // This analysis only makes sense if the parent capture is a
-                    // prefix of the child capture.
-                    assert!(
-                        child_capture.place.projections.len()
-                            >= parent_capture.place.projections.len(),
-                        "parent capture ({parent_capture:#?}) expected to be prefix of \
+    gen move {
+        let mut child_captures = child_captures.into_iter().enumerate().peekable();
+
+        // One parent capture may correspond to several child captures if we end up
+        // refining the set of captures via edition-2021 precise captures. We want to
+        // match up any number of child captures with one parent capture, so we keep
+        // peeking off this `Peekable` until the child doesn't match anymore.
+        for (parent_field_idx, parent_capture) in parent_captures.into_iter().enumerate() {
+            // Make sure we use every field at least once, b/c why are we capturing something
+            // if it's not used in the inner coroutine.
+            let mut field_used_at_least_once = false;
+
+            // A parent matches a child if they share the same prefix of projections.
+            // The child may have more, if it is capturing sub-fields out of
+            // something that is captured by-move in the parent closure.
+            while child_captures.peek().is_some_and(|(_, child_capture)| {
+                child_prefix_matches_parent_projections(parent_capture, child_capture)
+            }) {
+                let (child_field_idx, child_capture) = child_captures.next().unwrap();
+                // This analysis only makes sense if the parent capture is a
+                // prefix of the child capture.
+                assert!(
+                    child_capture.place.projections.len() >= parent_capture.place.projections.len(),
+                    "parent capture ({parent_capture:#?}) expected to be prefix of \
                     child capture ({child_capture:#?})"
-                    );
-
-                    yield for_each(
-                        (parent_field_idx, parent_capture),
-                        (child_field_idx, child_capture),
-                    );
-
-                    field_used_at_least_once = true;
-                }
+                );
 
-                // Make sure the field was used at least once.
-                assert!(
-                    field_used_at_least_once,
-                    "we captured {parent_capture:#?} but it was not used in the child coroutine?"
+                yield for_each(
+                    (parent_field_idx, parent_capture),
+                    (child_field_idx, child_capture),
                 );
+
+                field_used_at_least_once = true;
             }
-            assert_eq!(child_captures.next(), None, "leftover child captures?");
-        },
-    )
+
+            // Make sure the field was used at least once.
+            assert!(
+                field_used_at_least_once,
+                "we captured {parent_capture:#?} but it was not used in the child coroutine?"
+            );
+        }
+        assert_eq!(child_captures.next(), None, "leftover child captures?");
+    }
 }
 
 fn child_prefix_matches_parent_projections(

compiler/rustc_middle/src/ty/context.rs

@@ -2087,23 +2087,20 @@ impl<'tcx> TyCtxt<'tcx> {
         self.dep_graph.read_index(DepNodeIndex::FOREVER_RED_NODE);
 
         let definitions = &self.untracked.definitions;
-        std::iter::from_coroutine(
-            #[coroutine]
-            || {
-                let mut i = 0;
-
-                // Recompute the number of definitions each time, because our caller may be creating
-                // new ones.
-                while i < { definitions.read().num_definitions() } {
-                    let local_def_index = rustc_span::def_id::DefIndex::from_usize(i);
-                    yield LocalDefId { local_def_index };
-                    i += 1;
-                }
+        gen {
+            let mut i = 0;
+
+            // Recompute the number of definitions each time, because our caller may be creating
+            // new ones.
+            while i < { definitions.read().num_definitions() } {
+                let local_def_index = rustc_span::def_id::DefIndex::from_usize(i);
+                yield LocalDefId { local_def_index };
+                i += 1;
+            }
 
-                // Freeze definitions once we finish iterating on them, to prevent adding new ones.
-                definitions.freeze();
-            },
-        )
+            // Freeze definitions once we finish iterating on them, to prevent adding new ones.
+            definitions.freeze();
+        }
     }
 
     pub fn def_path_table(self) -> &'tcx rustc_hir::definitions::DefPathTable {