Merge from rustc

Author: The Miri Cronjob Bot

compiler/rustc_ast/src/mut_visit.rs

@@ -44,13 +44,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let mut res = self.lower_res(base_res);
 
         // When we have an `async` kw on a bound, map the trait it resolves to.
-        let mut bound_modifier_allowed_features = None;
         if let Some(TraitBoundModifiers { asyncness: BoundAsyncness::Async(_), .. }) = modifiers {
             match res {
                 Res::Def(DefKind::Trait, def_id) => {
-                    if let Some((async_def_id, features)) = self.map_trait_to_async_trait(def_id) {
+                    if let Some(async_def_id) = self.map_trait_to_async_trait(def_id) {
                         res = Res::Def(DefKind::Trait, async_def_id);
-                        bound_modifier_allowed_features = Some(features);
                     } else {
                         self.dcx().emit_err(AsyncBoundOnlyForFnTraits { span: p.span });
                     }
@@ -67,6 +65,16 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             }
         }
 
+        // Ungate the `async_fn_traits` feature in the path if the trait is
+        // named via either `async Fn*()` or `AsyncFn*()`.
+        let bound_modifier_allowed_features = if let Res::Def(DefKind::Trait, async_def_id) = res
+            && self.tcx.async_fn_trait_kind_from_def_id(async_def_id).is_some()
+        {
+            Some(self.allow_async_fn_traits.clone())
+        } else {
+            None
+        };
+
         let path_span_lo = p.span.shrink_to_lo();
         let proj_start = p.segments.len() - unresolved_segments;
         let path = self.arena.alloc(hir::Path {
@@ -506,14 +514,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     /// This only needs to be done until we unify `AsyncFn` and `Fn` traits into one
     /// that is generic over `async`ness, if that's ever possible, or modify the
     /// lowering of `async Fn()` bounds to desugar to another trait like `LendingFn`.
-    fn map_trait_to_async_trait(&self, def_id: DefId) -> Option<(DefId, Lrc<[Symbol]>)> {
+    fn map_trait_to_async_trait(&self, def_id: DefId) -> Option<DefId> {
         let lang_items = self.tcx.lang_items();
         if Some(def_id) == lang_items.fn_trait() {
-            Some((lang_items.async_fn_trait()?, self.allow_async_fn_traits.clone()))
+            lang_items.async_fn_trait()
         } else if Some(def_id) == lang_items.fn_mut_trait() {
-            Some((lang_items.async_fn_mut_trait()?, self.allow_async_fn_traits.clone()))
+            lang_items.async_fn_mut_trait()
         } else if Some(def_id) == lang_items.fn_once_trait() {
-            Some((lang_items.async_fn_once_trait()?, self.allow_async_fn_traits.clone()))
+            lang_items.async_fn_once_trait()
         } else {
             None
         }

compiler/rustc_ast_lowering/src/path.rs

@@ -4,7 +4,7 @@ use core::ops::ControlFlow;
 use rustc_ast as ast;
 use rustc_ast::mut_visit::MutVisitor;
 use rustc_ast::ptr::P;
-use rustc_ast::visit::Visitor;
+use rustc_ast::visit::{AssocCtxt, Visitor};
 use rustc_ast::NodeId;
 use rustc_ast::{mut_visit, visit};
 use rustc_ast::{Attribute, HasAttrs, HasTokens};
@@ -53,11 +53,8 @@ fn flat_map_annotatable(
 ) -> Option<Annotatable> {
     match annotatable {
         Annotatable::Item(item) => vis.flat_map_item(item).pop().map(Annotatable::Item),
-        Annotatable::TraitItem(item) => {
-            vis.flat_map_trait_item(item).pop().map(Annotatable::TraitItem)
-        }
-        Annotatable::ImplItem(item) => {
-            vis.flat_map_impl_item(item).pop().map(Annotatable::ImplItem)
+        Annotatable::AssocItem(item, ctxt) => {
+            Some(Annotatable::AssocItem(vis.flat_map_assoc_item(item, ctxt).pop()?, ctxt))
         }
         Annotatable::ForeignItem(item) => {
             vis.flat_map_foreign_item(item).pop().map(Annotatable::ForeignItem)
@@ -106,8 +103,7 @@ fn has_cfg_or_cfg_attr(annotatable: &Annotatable) -> bool {
 
     let res = match annotatable {
         Annotatable::Item(item) => CfgFinder.visit_item(item),
-        Annotatable::TraitItem(item) => CfgFinder.visit_assoc_item(item, visit::AssocCtxt::Trait),
-        Annotatable::ImplItem(item) => CfgFinder.visit_assoc_item(item, visit::AssocCtxt::Impl),
+        Annotatable::AssocItem(item, ctxt) => CfgFinder.visit_assoc_item(item, *ctxt),
         Annotatable::ForeignItem(item) => CfgFinder.visit_foreign_item(item),
         Annotatable::Stmt(stmt) => CfgFinder.visit_stmt(stmt),
         Annotatable::Expr(expr) => CfgFinder.visit_expr(expr),
@@ -150,14 +146,16 @@ impl CfgEval<'_> {
                 Annotatable::Item(_) => {
                     |parser| Ok(Annotatable::Item(parser.parse_item(ForceCollect::Yes)?.unwrap()))
                 }
-                Annotatable::TraitItem(_) => |parser| {
-                    Ok(Annotatable::TraitItem(
+                Annotatable::AssocItem(_, AssocCtxt::Trait) => |parser| {
+                    Ok(Annotatable::AssocItem(
                         parser.parse_trait_item(ForceCollect::Yes)?.unwrap().unwrap(),
+                        AssocCtxt::Trait,
                     ))
                 },
-                Annotatable::ImplItem(_) => |parser| {
-                    Ok(Annotatable::ImplItem(
+                Annotatable::AssocItem(_, AssocCtxt::Impl) => |parser| {
+                    Ok(Annotatable::AssocItem(
                         parser.parse_impl_item(ForceCollect::Yes)?.unwrap().unwrap(),
+                        AssocCtxt::Impl,
                     ))
                 },
                 Annotatable::ForeignItem(_) => |parser| {
@@ -214,72 +212,83 @@ impl MutVisitor for CfgEval<'_> {
     #[instrument(level = "trace", skip(self))]
     fn visit_expr(&mut self, expr: &mut P<ast::Expr>) {
         self.0.configure_expr(expr, false);
-        mut_visit::noop_visit_expr(expr, self);
+        mut_visit::walk_expr(self, expr);
     }
 
     #[instrument(level = "trace", skip(self))]
     fn visit_method_receiver_expr(&mut self, expr: &mut P<ast::Expr>) {
         self.0.configure_expr(expr, true);
-        mut_visit::noop_visit_expr(expr, self);
+        mut_visit::walk_expr(self, expr);
     }
 
     fn filter_map_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
         let mut expr = configure!(self, expr);
-        mut_visit::noop_visit_expr(&mut expr, self);
+        mut_visit::walk_expr(self, &mut expr);
         Some(expr)
     }
 
     fn flat_map_generic_param(
         &mut self,
         param: ast::GenericParam,
     ) -> SmallVec<[ast::GenericParam; 1]> {
-        mut_visit::noop_flat_map_generic_param(configure!(self, param), self)
+        let param = configure!(self, param);
+        mut_visit::walk_flat_map_generic_param(self, param)
     }
 
     fn flat_map_stmt(&mut self, stmt: ast::Stmt) -> SmallVec<[ast::Stmt; 1]> {
-        mut_visit::noop_flat_map_stmt(configure!(self, stmt), self)
+        let stmt = configure!(self, stmt);
+        mut_visit::walk_flat_map_stmt(self, stmt)
     }
 
     fn flat_map_item(&mut self, item: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
-        mut_visit::noop_flat_map_item(configure!(self, item), self)
-    }
-
-    fn flat_map_impl_item(&mut self, item: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
-        mut_visit::noop_flat_map_item(configure!(self, item), self)
+        let item = configure!(self, item);
+        mut_visit::walk_flat_map_item(self, item)
     }
 
-    fn flat_map_trait_item(&mut self, item: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
-        mut_visit::noop_flat_map_item(configure!(self, item), self)
+    fn flat_map_assoc_item(
+        &mut self,
+        item: P<ast::AssocItem>,
+        _ctxt: AssocCtxt,
+    ) -> SmallVec<[P<ast::AssocItem>; 1]> {
+        let item = configure!(self, item);
+        mut_visit::walk_flat_map_item(self, item)
     }
 
     fn flat_map_foreign_item(
         &mut self,
         foreign_item: P<ast::ForeignItem>,
     ) -> SmallVec<[P<ast::ForeignItem>; 1]> {
-        mut_visit::noop_flat_map_item(configure!(self, foreign_item), self)
+        let foreign_item = configure!(self, foreign_item);
+        mut_visit::walk_flat_map_item(self, foreign_item)
     }
 
     fn flat_map_arm(&mut self, arm: ast::Arm) -> SmallVec<[ast::Arm; 1]> {
-        mut_visit::noop_flat_map_arm(configure!(self, arm), self)
+        let arm = configure!(self, arm);
+        mut_visit::walk_flat_map_arm(self, arm)
     }
 
     fn flat_map_expr_field(&mut self, field: ast::ExprField) -> SmallVec<[ast::ExprField; 1]> {
-        mut_visit::noop_flat_map_expr_field(configure!(self, field), self)
+        let field = configure!(self, field);
+        mut_visit::walk_flat_map_expr_field(self, field)
     }
 
     fn flat_map_pat_field(&mut self, fp: ast::PatField) -> SmallVec<[ast::PatField; 1]> {
-        mut_visit::noop_flat_map_pat_field(configure!(self, fp), self)
+        let fp = configure!(self, fp);
+        mut_visit::walk_flat_map_pat_field(self, fp)
     }
 
     fn flat_map_param(&mut self, p: ast::Param) -> SmallVec<[ast::Param; 1]> {
-        mut_visit::noop_flat_map_param(configure!(self, p), self)
+        let p = configure!(self, p);
+        mut_visit::walk_flat_map_param(self, p)
     }
 
     fn flat_map_field_def(&mut self, sf: ast::FieldDef) -> SmallVec<[ast::FieldDef; 1]> {
-        mut_visit::noop_flat_map_field_def(configure!(self, sf), self)
+        let sf = configure!(self, sf);
+        mut_visit::walk_flat_map_field_def(self, sf)
     }
 
     fn flat_map_variant(&mut self, variant: ast::Variant) -> SmallVec<[ast::Variant; 1]> {
-        mut_visit::noop_flat_map_variant(configure!(self, variant), self)
+        let variant = configure!(self, variant);
+        mut_visit::walk_flat_map_variant(self, variant)
     }
 }

compiler/rustc_builtin_macros/src/cfg_eval.rs

@@ -122,15 +122,15 @@ impl TestHarnessGenerator<'_> {
 impl<'a> MutVisitor for TestHarnessGenerator<'a> {
     fn visit_crate(&mut self, c: &mut ast::Crate) {
         let prev_tests = mem::take(&mut self.tests);
-        noop_visit_crate(c, self);
+        walk_crate(self, c);
         self.add_test_cases(ast::CRATE_NODE_ID, c.spans.inner_span, prev_tests);
 
         // Create a main function to run our tests
         c.items.push(mk_main(&mut self.cx));
     }
 
-    fn flat_map_item(&mut self, i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
-        let mut item = i.into_inner();
+    fn flat_map_item(&mut self, mut i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
+        let item = &mut *i;
         if let Some(name) = get_test_name(&item) {
             debug!("this is a test item");
 
@@ -144,13 +144,13 @@ impl<'a> MutVisitor for TestHarnessGenerator<'a> {
             item.kind
         {
             let prev_tests = mem::take(&mut self.tests);
-            noop_visit_item_kind(&mut item.kind, self);
+            walk_item_kind(&mut item.kind, item.span, item.id, self);
             self.add_test_cases(item.id, span, prev_tests);
         } else {
             // But in those cases, we emit a lint to warn the user of these missing tests.
             walk_item(&mut InnerItemLinter { sess: self.cx.ext_cx.sess }, &item);
         }
-        smallvec![P(item)]
+        smallvec![i]
     }
 }
 
@@ -192,7 +192,7 @@ struct EntryPointCleaner<'a> {
 impl<'a> MutVisitor for EntryPointCleaner<'a> {
     fn flat_map_item(&mut self, i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
         self.depth += 1;
-        let item = noop_flat_map_item(i, self).expect_one("noop did something");
+        let item = walk_flat_map_item(self, i).expect_one("noop did something");
         self.depth -= 1;
 
         // Remove any #[rustc_main] or #[start] from the AST so it doesn't

compiler/rustc_builtin_macros/src/test_harness.rs

@@ -27,8 +27,7 @@ pub(crate) fn check_builtin_macro_attribute(ecx: &ExtCtxt<'_>, meta_item: &MetaI
 pub(crate) fn warn_on_duplicate_attribute(ecx: &ExtCtxt<'_>, item: &Annotatable, name: Symbol) {
     let attrs: Option<&[Attribute]> = match item {
         Annotatable::Item(item) => Some(&item.attrs),
-        Annotatable::TraitItem(item) => Some(&item.attrs),
-        Annotatable::ImplItem(item) => Some(&item.attrs),
+        Annotatable::AssocItem(item, _) => Some(&item.attrs),
         Annotatable::ForeignItem(item) => Some(&item.attrs),
         Annotatable::Expr(expr) => Some(&expr.attrs),
         Annotatable::Arm(arm) => Some(&arm.attrs),

compiler/rustc_builtin_macros/src/util.rs

@@ -100,7 +100,33 @@ impl Qualif for HasMutInterior {
     }
 
     fn in_any_value_of_ty<'tcx>(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> bool {
-        !ty.is_freeze(cx.tcx, cx.param_env)
+        // Avoid selecting for simple cases, such as builtin types.
+        if ty.is_trivially_freeze() {
+            return false;
+        }
+
+        // We do not use `ty.is_freeze` here, because that requires revealing opaque types, which
+        // requires borrowck, which in turn will invoke mir_const_qualifs again, causing a cycle error.
+        // Instead we invoke an obligation context manually, and provide the opaque type inference settings
+        // that allow the trait solver to just error out instead of cycling.
+        let freeze_def_id = cx.tcx.require_lang_item(LangItem::Freeze, Some(cx.body.span));
+
+        let obligation = Obligation::new(
+            cx.tcx,
+            ObligationCause::dummy_with_span(cx.body.span),
+            cx.param_env,
+            ty::TraitRef::new(cx.tcx, freeze_def_id, [ty::GenericArg::from(ty)]),
+        );
+
+        let infcx = cx
+            .tcx
+            .infer_ctxt()
+            .with_opaque_type_inference(cx.body.source.def_id().expect_local())
+            .build();
+        let ocx = ObligationCtxt::new(&infcx);
+        ocx.register_obligation(obligation);
+        let errors = ocx.select_all_or_error();
+        !errors.is_empty()
     }
 
     fn in_adt_inherently<'tcx>(

compiler/rustc_const_eval/src/check_consts/qualifs.rs

@@ -37,8 +37,7 @@ use thin_vec::ThinVec;
 #[derive(Debug, Clone)]
 pub enum Annotatable {
     Item(P<ast::Item>),
-    TraitItem(P<ast::AssocItem>),
-    ImplItem(P<ast::AssocItem>),
+    AssocItem(P<ast::AssocItem>, AssocCtxt),
     ForeignItem(P<ast::ForeignItem>),
     Stmt(P<ast::Stmt>),
     Expr(P<ast::Expr>),
@@ -56,8 +55,7 @@ impl Annotatable {
     pub fn span(&self) -> Span {
         match self {
             Annotatable::Item(item) => item.span,
-            Annotatable::TraitItem(trait_item) => trait_item.span,
-            Annotatable::ImplItem(impl_item) => impl_item.span,
+            Annotatable::AssocItem(assoc_item, _) => assoc_item.span,
             Annotatable::ForeignItem(foreign_item) => foreign_item.span,
             Annotatable::Stmt(stmt) => stmt.span,
             Annotatable::Expr(expr) => expr.span,
@@ -75,8 +73,7 @@ impl Annotatable {
     pub fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
         match self {
             Annotatable::Item(item) => item.visit_attrs(f),
-            Annotatable::TraitItem(trait_item) => trait_item.visit_attrs(f),
-            Annotatable::ImplItem(impl_item) => impl_item.visit_attrs(f),
+            Annotatable::AssocItem(assoc_item, _) => assoc_item.visit_attrs(f),
             Annotatable::ForeignItem(foreign_item) => foreign_item.visit_attrs(f),
             Annotatable::Stmt(stmt) => stmt.visit_attrs(f),
             Annotatable::Expr(expr) => expr.visit_attrs(f),
@@ -94,8 +91,7 @@ impl Annotatable {
     pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) -> V::Result {
         match self {
             Annotatable::Item(item) => visitor.visit_item(item),
-            Annotatable::TraitItem(item) => visitor.visit_assoc_item(item, AssocCtxt::Trait),
-            Annotatable::ImplItem(item) => visitor.visit_assoc_item(item, AssocCtxt::Impl),
+            Annotatable::AssocItem(item, ctxt) => visitor.visit_assoc_item(item, *ctxt),
             Annotatable::ForeignItem(foreign_item) => visitor.visit_foreign_item(foreign_item),
             Annotatable::Stmt(stmt) => visitor.visit_stmt(stmt),
             Annotatable::Expr(expr) => visitor.visit_expr(expr),
@@ -113,9 +109,7 @@ impl Annotatable {
     pub fn to_tokens(&self) -> TokenStream {
         match self {
             Annotatable::Item(node) => TokenStream::from_ast(node),
-            Annotatable::TraitItem(node) | Annotatable::ImplItem(node) => {
-                TokenStream::from_ast(node)
-            }
+            Annotatable::AssocItem(node, _) => TokenStream::from_ast(node),
             Annotatable::ForeignItem(node) => TokenStream::from_ast(node),
             Annotatable::Stmt(node) => {
                 assert!(!matches!(node.kind, ast::StmtKind::Empty));
@@ -142,14 +136,14 @@ impl Annotatable {
 
     pub fn expect_trait_item(self) -> P<ast::AssocItem> {
         match self {
-            Annotatable::TraitItem(i) => i,
+            Annotatable::AssocItem(i, AssocCtxt::Trait) => i,
             _ => panic!("expected Item"),
         }
     }
 
     pub fn expect_impl_item(self) -> P<ast::AssocItem> {
         match self {
-            Annotatable::ImplItem(i) => i,
+            Annotatable::AssocItem(i, AssocCtxt::Impl) => i,
             _ => panic!("expected Item"),
         }
     }