Auto merge of #98521 - JohnTitor:rollup-tl9sblx, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #98371 (Fix printing `impl trait` under binders)
 - #98385 (Work around llvm 12's memory ordering restrictions.)
 - #98474 (x.py: Support systems with only `python3` not `python`)
 - #98488 (Bump RLS to latest master on rust-lang/rls)
 - #98491 (Fix backtrace UI test when panic=abort is used)
 - #98502 (Fix source sidebar hover in ayu theme)
 - #98509 (diagnostics: consider parameter count when suggesting smart pointers)
 - #98513 (Fix LLVM rebuild with download-ci-llvm.)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: Cargo.lock

@@ -3054,7 +3054,6 @@ name = "racer"
 version = "2.2.2"
 dependencies = [
  "bitflags",
- "clap 2.34.0",
  "derive_more",
  "env_logger 0.7.1",
  "humantime 2.0.1",
@@ -3278,7 +3277,7 @@ dependencies = [
  "difference",
  "env_logger 0.9.0",
  "futures 0.3.19",
- "heck 0.3.1",
+ "heck 0.4.0",
  "home",
  "itertools",
  "jsonrpc-core",

Diff for: compiler/rustc_codegen_llvm/src/builder.rs

@@ -1064,11 +1064,25 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         dst: &'ll Value,
         cmp: &'ll Value,
         src: &'ll Value,
-        order: rustc_codegen_ssa::common::AtomicOrdering,
+        mut order: rustc_codegen_ssa::common::AtomicOrdering,
         failure_order: rustc_codegen_ssa::common::AtomicOrdering,
         weak: bool,
     ) -> &'ll Value {
         let weak = if weak { llvm::True } else { llvm::False };
+        if llvm_util::get_version() < (13, 0, 0) {
+            use rustc_codegen_ssa::common::AtomicOrdering::*;
+            // Older llvm has the pre-C++17 restriction on
+            // success and failure memory ordering,
+            // requiring the former to be at least as strong as the latter.
+            // So, for llvm 12, we upgrade the success ordering to a stronger
+            // one if necessary.
+            match (order, failure_order) {
+                (Relaxed, Acquire) => order = Acquire,
+                (Release, Acquire) => order = AcquireRelease,
+                (_, SequentiallyConsistent) => order = SequentiallyConsistent,
+                _ => {}
+            }
+        }
         unsafe {
             llvm::LLVMRustBuildAtomicCmpXchg(
                 self.llbuilder,

Diff for: compiler/rustc_middle/src/ty/print/pretty.rs

@@ -226,7 +226,7 @@ pub trait PrettyPrinter<'tcx>:
         value.as_ref().skip_binder().print(self)
     }
 
-    fn wrap_binder<T, F: Fn(&T, Self) -> Result<Self, fmt::Error>>(
+    fn wrap_binder<T, F: FnOnce(&T, Self) -> Result<Self, fmt::Error>>(
         self,
         value: &ty::Binder<'tcx, T>,
         f: F,
@@ -773,26 +773,26 @@ pub trait PrettyPrinter<'tcx>:
         def_id: DefId,
         substs: &'tcx ty::List<ty::GenericArg<'tcx>>,
     ) -> Result<Self::Type, Self::Error> {
-        define_scoped_cx!(self);
+        let tcx = self.tcx();
 
         // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
         // by looking up the projections associated with the def_id.
-        let bounds = self.tcx().bound_explicit_item_bounds(def_id);
+        let bounds = tcx.bound_explicit_item_bounds(def_id);
 
         let mut traits = FxIndexMap::default();
         let mut fn_traits = FxIndexMap::default();
         let mut is_sized = false;
 
         for predicate in bounds.transpose_iter().map(|e| e.map_bound(|(p, _)| *p)) {
-            let predicate = predicate.subst(self.tcx(), substs);
+            let predicate = predicate.subst(tcx, substs);
             let bound_predicate = predicate.kind();
 
             match bound_predicate.skip_binder() {
                 ty::PredicateKind::Trait(pred) => {
                     let trait_ref = bound_predicate.rebind(pred.trait_ref);
 
                     // Don't print + Sized, but rather + ?Sized if absent.
-                    if Some(trait_ref.def_id()) == self.tcx().lang_items().sized_trait() {
+                    if Some(trait_ref.def_id()) == tcx.lang_items().sized_trait() {
                         is_sized = true;
                         continue;
                     }
@@ -801,7 +801,7 @@ pub trait PrettyPrinter<'tcx>:
                 }
                 ty::PredicateKind::Projection(pred) => {
                     let proj_ref = bound_predicate.rebind(pred);
-                    let trait_ref = proj_ref.required_poly_trait_ref(self.tcx());
+                    let trait_ref = proj_ref.required_poly_trait_ref(tcx);
 
                     // Projection type entry -- the def-id for naming, and the ty.
                     let proj_ty = (proj_ref.projection_def_id(), proj_ref.term());
@@ -817,148 +817,155 @@ pub trait PrettyPrinter<'tcx>:
             }
         }
 
+        write!(self, "impl ")?;
+
         let mut first = true;
         // Insert parenthesis around (Fn(A, B) -> C) if the opaque ty has more than one other trait
         let paren_needed = fn_traits.len() > 1 || traits.len() > 0 || !is_sized;
 
-        p!("impl");
-
         for (fn_once_trait_ref, entry) in fn_traits {
-            // Get the (single) generic ty (the args) of this FnOnce trait ref.
-            let generics = self.tcx().generics_of(fn_once_trait_ref.def_id());
-            let args =
-                generics.own_substs_no_defaults(self.tcx(), fn_once_trait_ref.skip_binder().substs);
-
-            match (entry.return_ty, args[0].expect_ty()) {
-                // We can only print `impl Fn() -> ()` if we have a tuple of args and we recorded
-                // a return type.
-                (Some(return_ty), arg_tys) if matches!(arg_tys.kind(), ty::Tuple(_)) => {
-                    let name = if entry.fn_trait_ref.is_some() {
-                        "Fn"
-                    } else if entry.fn_mut_trait_ref.is_some() {
-                        "FnMut"
-                    } else {
-                        "FnOnce"
-                    };
+            write!(self, "{}", if first { "" } else { " + " })?;
+            write!(self, "{}", if paren_needed { "(" } else { "" })?;
 
-                    p!(
-                        write("{}", if first { " " } else { " + " }),
-                        write("{}{}(", if paren_needed { "(" } else { "" }, name)
-                    );
+            self = self.wrap_binder(&fn_once_trait_ref, |trait_ref, mut cx| {
+                define_scoped_cx!(cx);
+                // Get the (single) generic ty (the args) of this FnOnce trait ref.
+                let generics = tcx.generics_of(trait_ref.def_id);
+                let args = generics.own_substs_no_defaults(tcx, trait_ref.substs);
+
+                match (entry.return_ty, args[0].expect_ty()) {
+                    // We can only print `impl Fn() -> ()` if we have a tuple of args and we recorded
+                    // a return type.
+                    (Some(return_ty), arg_tys) if matches!(arg_tys.kind(), ty::Tuple(_)) => {
+                        let name = if entry.fn_trait_ref.is_some() {
+                            "Fn"
+                        } else if entry.fn_mut_trait_ref.is_some() {
+                            "FnMut"
+                        } else {
+                            "FnOnce"
+                        };
 
-                    for (idx, ty) in arg_tys.tuple_fields().iter().enumerate() {
-                        if idx > 0 {
-                            p!(", ");
+                        p!(write("{}(", name));
+
+                        for (idx, ty) in arg_tys.tuple_fields().iter().enumerate() {
+                            if idx > 0 {
+                                p!(", ");
+                            }
+                            p!(print(ty));
                         }
-                        p!(print(ty));
-                    }
 
-                    p!(")");
-                    if let Term::Ty(ty) = return_ty.skip_binder() {
-                        if !ty.is_unit() {
-                            p!(" -> ", print(return_ty));
+                        p!(")");
+                        if let Term::Ty(ty) = return_ty.skip_binder() {
+                            if !ty.is_unit() {
+                                p!(" -> ", print(return_ty));
+                            }
                         }
-                    }
-                    p!(write("{}", if paren_needed { ")" } else { "" }));
+                        p!(write("{}", if paren_needed { ")" } else { "" }));
 
-                    first = false;
-                }
-                // If we got here, we can't print as a `impl Fn(A, B) -> C`. Just record the
-                // trait_refs we collected in the OpaqueFnEntry as normal trait refs.
-                _ => {
-                    if entry.has_fn_once {
-                        traits.entry(fn_once_trait_ref).or_default().extend(
-                            // Group the return ty with its def id, if we had one.
-                            entry
-                                .return_ty
-                                .map(|ty| (self.tcx().lang_items().fn_once_output().unwrap(), ty)),
-                        );
-                    }
-                    if let Some(trait_ref) = entry.fn_mut_trait_ref {
-                        traits.entry(trait_ref).or_default();
+                        first = false;
                     }
-                    if let Some(trait_ref) = entry.fn_trait_ref {
-                        traits.entry(trait_ref).or_default();
+                    // If we got here, we can't print as a `impl Fn(A, B) -> C`. Just record the
+                    // trait_refs we collected in the OpaqueFnEntry as normal trait refs.
+                    _ => {
+                        if entry.has_fn_once {
+                            traits.entry(fn_once_trait_ref).or_default().extend(
+                                // Group the return ty with its def id, if we had one.
+                                entry
+                                    .return_ty
+                                    .map(|ty| (tcx.lang_items().fn_once_output().unwrap(), ty)),
+                            );
+                        }
+                        if let Some(trait_ref) = entry.fn_mut_trait_ref {
+                            traits.entry(trait_ref).or_default();
+                        }
+                        if let Some(trait_ref) = entry.fn_trait_ref {
+                            traits.entry(trait_ref).or_default();
+                        }
                     }
                 }
-            }
+
+                Ok(cx)
+            })?;
         }
 
         // Print the rest of the trait types (that aren't Fn* family of traits)
         for (trait_ref, assoc_items) in traits {
-            p!(
-                write("{}", if first { " " } else { " + " }),
-                print(trait_ref.skip_binder().print_only_trait_name())
-            );
+            write!(self, "{}", if first { "" } else { " + " })?;
+
+            self = self.wrap_binder(&trait_ref, |trait_ref, mut cx| {
+                define_scoped_cx!(cx);
+                p!(print(trait_ref.print_only_trait_name()));
 
-            let generics = self.tcx().generics_of(trait_ref.def_id());
-            let args = generics.own_substs_no_defaults(self.tcx(), trait_ref.skip_binder().substs);
+                let generics = tcx.generics_of(trait_ref.def_id);
+                let args = generics.own_substs_no_defaults(tcx, trait_ref.substs);
 
-            if !args.is_empty() || !assoc_items.is_empty() {
-                let mut first = true;
+                if !args.is_empty() || !assoc_items.is_empty() {
+                    let mut first = true;
 
-                for ty in args {
-                    if first {
-                        p!("<");
-                        first = false;
-                    } else {
-                        p!(", ");
+                    for ty in args {
+                        if first {
+                            p!("<");
+                            first = false;
+                        } else {
+                            p!(", ");
+                        }
+                        p!(print(ty));
                     }
-                    p!(print(trait_ref.rebind(*ty)));
-                }
 
-                for (assoc_item_def_id, term) in assoc_items {
-                    // Skip printing `<[generator@] as Generator<_>>::Return` from async blocks,
-                    // unless we can find out what generator return type it comes from.
-                    let term = if let Some(ty) = term.skip_binder().ty()
-                        && let ty::Projection(ty::ProjectionTy { item_def_id, substs }) = ty.kind()
-                        && Some(*item_def_id) == self.tcx().lang_items().generator_return()
-                    {
-                        if let ty::Generator(_, substs, _) = substs.type_at(0).kind() {
-                            let return_ty = substs.as_generator().return_ty();
-                            if !return_ty.is_ty_infer() {
-                                return_ty.into()
+                    for (assoc_item_def_id, term) in assoc_items {
+                        // Skip printing `<[generator@] as Generator<_>>::Return` from async blocks,
+                        // unless we can find out what generator return type it comes from.
+                        let term = if let Some(ty) = term.skip_binder().ty()
+                            && let ty::Projection(ty::ProjectionTy { item_def_id, substs }) = ty.kind()
+                            && Some(*item_def_id) == tcx.lang_items().generator_return()
+                        {
+                            if let ty::Generator(_, substs, _) = substs.type_at(0).kind() {
+                                let return_ty = substs.as_generator().return_ty();
+                                if !return_ty.is_ty_infer() {
+                                    return_ty.into()
+                                } else {
+                                    continue;
+                                }
                             } else {
                                 continue;
                             }
                         } else {
-                            continue;
-                        }
-                    } else {
-                        term.skip_binder()
-                    };
+                            term.skip_binder()
+                        };
 
-                    if first {
-                        p!("<");
-                        first = false;
-                    } else {
-                        p!(", ");
-                    }
+                        if first {
+                            p!("<");
+                            first = false;
+                        } else {
+                            p!(", ");
+                        }
 
-                    p!(write("{} = ", self.tcx().associated_item(assoc_item_def_id).name));
+                        p!(write("{} = ", tcx.associated_item(assoc_item_def_id).name));
 
-                    match term {
-                        Term::Ty(ty) => {
-                            p!(print(ty))
-                        }
-                        Term::Const(c) => {
-                            p!(print(c));
-                        }
-                    };
-                }
+                        match term {
+                            Term::Ty(ty) => {
+                                p!(print(ty))
+                            }
+                            Term::Const(c) => {
+                                p!(print(c));
+                            }
+                        };
+                    }
 
-                if !first {
-                    p!(">");
+                    if !first {
+                        p!(">");
+                    }
                 }
-            }
 
-            first = false;
+                first = false;
+                Ok(cx)
+            })?;
         }
 
         if !is_sized {
-            p!(write("{}?Sized", if first { " " } else { " + " }));
+            write!(self, "{}?Sized", if first { "" } else { " + " })?;
         } else if first {
-            p!(" Sized");
+            write!(self, "Sized")?;
         }
 
         Ok(self)
@@ -1869,7 +1876,7 @@ impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
         self.pretty_in_binder(value)
     }
 
-    fn wrap_binder<T, C: Fn(&T, Self) -> Result<Self, Self::Error>>(
+    fn wrap_binder<T, C: FnOnce(&T, Self) -> Result<Self, Self::Error>>(
         self,
         value: &ty::Binder<'tcx, T>,
         f: C,
@@ -2256,7 +2263,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
         Ok(inner)
     }
 
-    pub fn pretty_wrap_binder<T, C: Fn(&T, Self) -> Result<Self, fmt::Error>>(
+    pub fn pretty_wrap_binder<T, C: FnOnce(&T, Self) -> Result<Self, fmt::Error>>(
         self,
         value: &ty::Binder<'tcx, T>,
         f: C,

Diff for: compiler/rustc_typeck/src/check/method/suggest.rs

@@ -994,6 +994,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         span,
                         rcvr_ty,
                         item_name,
+                        args.map(|args| args.len()),
                         source,
                         out_of_scope_traits,
                         &unsatisfied_predicates,
@@ -1732,6 +1733,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         span: Span,
         rcvr_ty: Ty<'tcx>,
         item_name: Ident,
+        inputs_len: Option<usize>,
         source: SelfSource<'tcx>,
         valid_out_of_scope_traits: Vec<DefId>,
         unsatisfied_predicates: &[(
@@ -1808,7 +1810,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         // Explicitly ignore the `Pin::as_ref()` method as `Pin` does not
                         // implement the `AsRef` trait.
                         let skip = skippable.contains(&did)
-                            || (("Pin::new" == *pre) && (sym::as_ref == item_name.name));
+                            || (("Pin::new" == *pre) && (sym::as_ref == item_name.name))
+                            || inputs_len.map_or(false, |inputs_len| pick.item.kind == ty::AssocKind::Fn && self.tcx.fn_sig(pick.item.def_id).skip_binder().inputs().len() != inputs_len);
                         // Make sure the method is defined for the *actual* receiver: we don't
                         // want to treat `Box<Self>` as a receiver if it only works because of
                         // an autoderef to `&self`