Auto merge of #126319 - workingjubilee:rollup-lendnud, r=workingjubilee

Rollup of 16 pull requests

Successful merges:

 - #123374 (DOC: Add FFI example for slice::from_raw_parts())
 - #124514 (Recommend to never display zero disambiguators when demangling v0 symbols)
 - #125978 (Cleanup: HIR ty lowering: Consolidate the places that do assoc item probing & access checking)
 - #125980 (Nvptx remove direct passmode)
 - #126187 (For E0277 suggest adding `Result` return type for function when using QuestionMark `?` in the body.)
 - #126210 (docs(core): make more const_ptr doctests assert instead of printing)
 - #126249 (Simplify `[T; N]::try_map` signature)
 - #126256 (Add {{target}} substitution to compiletest)
 - #126263 (Make issue-122805.rs big endian compatible)
 - #126281 (set_env: State the conclusion upfront)
 - #126286 (Make `storage-live.rs` robust against rustc internal changes.)
 - #126287 (Update a cranelift patch file for formatting changes.)
 - #126301 (Use `tidy` to sort crate attributes for all compiler crates.)
 - #126305 (Make PathBuf less Ok with adding UTF-16 then `into_string`)
 - #126310 (Migrate run make prefer rlib)
 - #126314 (fix RELEASES: we do not support upcasting to auto traits)

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

compiler/rustc_abi/src/lib.rs

@@ -1,7 +1,9 @@
-#![cfg_attr(feature = "nightly", feature(step_trait))]
+// tidy-alphabetical-start
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", doc(rust_logo))]
 #![cfg_attr(feature = "nightly", feature(rustdoc_internals))]
+#![cfg_attr(feature = "nightly", feature(step_trait))]
+// tidy-alphabetical-end
 
 use std::fmt;
 use std::num::{NonZeroUsize, ParseIntError};

compiler/rustc_arena/src/lib.rs

@@ -7,23 +7,25 @@
 //!
 //! This crate implements several kinds of arena.
 
+// tidy-alphabetical-start
+#![allow(clippy::mut_from_ref)] // Arena allocators are one place where this pattern is fine.
+#![allow(internal_features)]
+#![cfg_attr(test, feature(test))]
+#![deny(unsafe_op_in_unsafe_fn)]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(no_crate_inject, attr(deny(warnings)))
 )]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
 #![feature(core_intrinsics)]
-#![feature(dropck_eyepatch)]
-#![feature(new_uninit)]
-#![feature(maybe_uninit_slice)]
 #![feature(decl_macro)]
+#![feature(dropck_eyepatch)]
+#![feature(maybe_uninit_slice)]
+#![feature(new_uninit)]
 #![feature(rustc_attrs)]
-#![cfg_attr(test, feature(test))]
+#![feature(rustdoc_internals)]
 #![feature(strict_provenance)]
-#![deny(unsafe_op_in_unsafe_fn)]
-#![allow(internal_features)]
-#![allow(clippy::mut_from_ref)] // Arena allocators are one of the places where this pattern is fine.
+// tidy-alphabetical-end
 
 use smallvec::SmallVec;
 

compiler/rustc_ast/src/lib.rs

@@ -4,20 +4,22 @@
 //!
 //! This API is completely unstable and subject to change.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(attr(deny(warnings)))
 )]
 #![doc(rust_logo)]
-#![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
-#![feature(never_type)]
 #![feature(negative_impls)]
+#![feature(never_type)]
+#![feature(rustdoc_internals)]
 #![feature(stmt_expr_attributes)]
+// tidy-alphabetical-end
 
 pub mod util {
     pub mod case;

compiler/rustc_ast_ir/src/lib.rs

@@ -1,6 +1,8 @@
+// tidy-alphabetical-start
+#![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", feature(never_type))]
 #![cfg_attr(feature = "nightly", feature(rustc_attrs))]
-#![cfg_attr(feature = "nightly", allow(internal_features))]
+// tidy-alphabetical-end
 
 #[cfg(feature = "nightly")]
 use rustc_macros::{Decodable, Encodable, HashStable_NoContext};

compiler/rustc_ast_lowering/src/lib.rs

@@ -30,12 +30,14 @@
 //! get confused if the spans from leaf AST nodes occur in multiple places
 //! in the HIR, especially for multiple identifiers.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(let_chains)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use crate::errors::{AssocTyParentheses, AssocTyParenthesesSub, MisplacedImplTrait};
 use rustc_ast::node_id::NodeMap;

compiler/rustc_ast_passes/src/lib.rs

@@ -4,13 +4,15 @@
 //!
 //! The crate also contains other misc AST visitors, e.g. `node_count` and `show_span`.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_is_partitioned)]
 #![feature(let_chains)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 pub mod ast_validation;
 mod errors;

compiler/rustc_ast_pretty/src/lib.rs

@@ -1,7 +1,9 @@
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
 #![feature(box_patterns)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 mod helpers;
 pub mod pp;

compiler/rustc_attr/src/lib.rs

@@ -4,10 +4,12 @@
 //! The goal is to move the definition of `MetaItem` and things that don't need to be in `syntax`
 //! to this crate.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
 #![feature(let_chains)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 mod builtin;
 mod session_diagnostics;

compiler/rustc_baked_icu_data/src/lib.rs

@@ -20,10 +20,12 @@
 //! --cldr-tag latest --icuexport-tag latest -o src/data
 //! ```
 
-#![allow(internal_features)]
-#![feature(rustdoc_internals)]
-#![doc(rust_logo)]
+// tidy-alphabetical-start
 #![allow(elided_lifetimes_in_paths)]
+#![allow(internal_features)]
+#![doc(rust_logo)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 mod data {
     include!("data/mod.rs");

compiler/rustc_borrowck/src/lib.rs

@@ -1,7 +1,7 @@
 //! This query borrow-checks the MIR to (further) ensure it is not broken.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
@@ -10,8 +10,10 @@
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
+#![feature(rustdoc_internals)]
 #![feature(stmt_expr_attributes)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_builtin_macros/src/lib.rs

@@ -1,12 +1,12 @@
 //! This crate contains implementations of built-in macros and other code generating facilities
 //! injecting code into the crate before it is lowered to HIR.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
-#![feature(rustdoc_internals)]
-#![doc(rust_logo)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
@@ -15,7 +15,9 @@
 #![feature(lint_reasons)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
+#![feature(rustdoc_internals)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 extern crate proc_macro;
 

compiler/rustc_codegen_cranelift/patches/0029-stdlib-rawdylib-processprng.patch

@@ -12,7 +12,7 @@ diff --git a/library/std/src/sys/pal/windows/c.rs b/library/std/src/sys/pal/wind
 index ad8e01bfa9b..9ca8e4c16ce 100644
 --- a/library/std/src/sys/pal/windows/c.rs
 +++ b/library/std/src/sys/pal/windows/c.rs
-@@ -323,7 +323,7 @@ pub unsafe fn NtWriteFile(
+@@ -312,7 +312,7 @@ pub unsafe fn NtWriteFile(
  
  // Use raw-dylib to import ProcessPrng as we can't rely on there being an import library.
  cfg_if::cfg_if! {
@@ -26,8 +26,8 @@ index e427546222a..f2fe42a4d51 100644
 --- a/library/std/src/sys/pal/windows/rand.rs
 +++ b/library/std/src/sys/pal/windows/rand.rs
 @@ -2,7 +2,7 @@
- use core::mem;
- use core::ptr;
+ 
+ use crate::sys::c;
  
 -#[cfg(not(target_vendor = "win7"))]
 +#[cfg(any())]

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -1,13 +1,16 @@
-#![cfg_attr(doc, allow(internal_features))]
-#![cfg_attr(doc, feature(rustdoc_internals))]
-#![cfg_attr(doc, doc(rust_logo))]
-#![feature(rustc_private)]
-// Note: please avoid adding other feature gates where possible
+// tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(doc, allow(internal_features))]
+#![cfg_attr(doc, doc(rust_logo))]
+#![cfg_attr(doc, feature(rustdoc_internals))]
+// Note: please avoid adding other feature gates where possible
+#![feature(rustc_private)]
+// Note: please avoid adding other feature gates where possible
 #![warn(rust_2018_idioms)]
-#![warn(unused_lifetimes)]
 #![warn(unreachable_pub)]
+#![warn(unused_lifetimes)]
+// tidy-alphabetical-end
 
 extern crate jobserver;
 #[macro_use]

compiler/rustc_codegen_llvm/src/lib.rs

@@ -4,16 +4,18 @@
 //!
 //! This API is completely unstable and subject to change.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
-#![doc(rust_logo)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![doc(rust_logo)]
 #![feature(exact_size_is_empty)]
 #![feature(extern_types)]
 #![feature(hash_raw_entry)]
+#![feature(impl_trait_in_assoc_type)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
-#![feature(impl_trait_in_assoc_type)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use back::owned_target_machine::OwnedTargetMachine;
 use back::write::{create_informational_target_machine, create_target_machine};

compiler/rustc_codegen_ssa/src/lib.rs

@@ -1,15 +1,17 @@
-#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
-#![doc(rust_logo)]
-#![feature(rustdoc_internals)]
+// tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![doc(rust_logo)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(negative_impls)]
+#![feature(rustdoc_internals)]
 #![feature(strict_provenance)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 //! This crate contains codegen code that is used by all codegen backends (LLVM and others).
 //! The backend-agnostic functions of this crate use functions defined in various traits that

compiler/rustc_const_eval/src/lib.rs

@@ -1,18 +1,20 @@
+// tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
+#![feature(if_let_guard)]
 #![feature(let_chains)]
+#![feature(never_type)]
+#![feature(rustdoc_internals)]
 #![feature(slice_ptr_get)]
 #![feature(strict_provenance)]
-#![feature(never_type)]
 #![feature(trait_alias)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
-#![feature(if_let_guard)]
+// tidy-alphabetical-end
 
 pub mod check_consts;
 pub mod const_eval;

compiler/rustc_driver/src/lib.rs

@@ -1,8 +1,10 @@
 // This crate is intentionally empty and a re-export of `rustc_driver_impl` to allow the code in
 // `rustc_driver_impl` to be compiled in parallel with other crates.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 pub use rustc_driver_impl::*;

compiler/rustc_driver_impl/src/lib.rs

@@ -4,16 +4,18 @@
 //!
 //! This API is completely unstable and subject to change.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
-#![allow(internal_features)]
 #![feature(decl_macro)]
 #![feature(let_chains)]
 #![feature(panic_backtrace_config)]
 #![feature(panic_update_hook)]
 #![feature(result_flattening)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use rustc_ast as ast;
 use rustc_codegen_ssa::{traits::CodegenBackend, CodegenErrors, CodegenResults};

compiler/rustc_error_codes/src/lib.rs

@@ -1,10 +1,12 @@
 //! This library is used to gather all error codes into one place, to make
 //! their maintenance easier.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
-#![doc(rust_logo)]
 #![deny(rustdoc::invalid_codeblock_attributes)]
+#![doc(rust_logo)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 // This higher-order macro defines the error codes that are in use. It is used
 // in the `rustc_errors` crate. Removed error codes are listed in the comment

compiler/rustc_error_messages/src/lib.rs

@@ -1,8 +1,10 @@
-#![doc(rust_logo)]
-#![feature(rustdoc_internals)]
-#![feature(rustc_attrs)]
-#![feature(type_alias_impl_trait)]
+// tidy-alphabetical-start
 #![allow(internal_features)]
+#![doc(rust_logo)]
+#![feature(rustc_attrs)]
+#![feature(rustdoc_internals)]
+#![feature(type_alias_impl_trait)]
+// tidy-alphabetical-end
 
 use fluent_bundle::FluentResource;
 use fluent_syntax::parser::ParserError;

compiler/rustc_feature/src/lib.rs

@@ -11,9 +11,11 @@
 //! even if it is stabilized or removed, *do not remove it*. Instead, move the
 //! symbol to the `accepted` or `removed` modules respectively.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 mod accepted;
 mod builtin_attrs;

compiler/rustc_fluent_macro/src/lib.rs

@@ -1,10 +1,12 @@
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![allow(rustc::default_hash_types)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]
-#![allow(rustc::default_hash_types)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use proc_macro::TokenStream;
 

compiler/rustc_fs_util/src/lib.rs

@@ -1,7 +1,9 @@
+// tidy-alphabetical-start
 use std::ffi::CString;
 use std::fs;
 use std::io;
 use std::path::{absolute, Path, PathBuf};
+// tidy-alphabetical-end
 
 // Unfortunately, on windows, it looks like msvcrt.dll is silently translating
 // verbatim paths under the hood to non-verbatim paths! This manifests itself as

compiler/rustc_graphviz/src/lib.rs

@@ -269,13 +269,15 @@
 //!
 //! * [DOT language](https://www.graphviz.org/doc/info/lang.html)
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(attr(allow(unused_variables), deny(warnings)))
 )]
-#![feature(rustdoc_internals)]
 #![doc(rust_logo)]
-#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use LabelText::*;
 

compiler/rustc_hir/src/hir.rs

@@ -1038,6 +1038,7 @@ pub struct Block<'hir> {
     pub hir_id: HirId,
     /// Distinguishes between `unsafe { ... }` and `{ ... }`.
     pub rules: BlockCheckMode,
+    /// The span includes the curly braces `{` and `}` around the block.
     pub span: Span,
     /// If true, then there may exist `break 'a` values that aim to
     /// break out of this block early.

compiler/rustc_hir/src/lib.rs

@@ -2,13 +2,15 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/hir.html
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![feature(associated_type_defaults)]
 #![feature(closure_track_caller)]
 #![feature(let_chains)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
 #![feature(variant_count)]
-#![allow(internal_features)]
+// tidy-alphabetical-end
 
 extern crate self as rustc_hir;
 

compiler/rustc_hir_analysis/messages.ftl

@@ -8,6 +8,10 @@ hir_analysis_assoc_item_constraints_not_allowed_here =
     associated item constraints are not allowed here
     .label = associated item constraint not allowed here
 
+hir_analysis_assoc_item_is_private = {$kind} `{$name}` is private
+    .label = private {$kind}
+    .defined_here_label = the {$kind} is defined here
+
 hir_analysis_assoc_item_not_found = associated {$assoc_kind} `{$assoc_name}` not found for `{$ty_param_name}`
 
 hir_analysis_assoc_item_not_found_found_in_other_trait_label = there is {$identically_named ->

compiler/rustc_hir_analysis/src/errors.rs

@@ -55,6 +55,18 @@ pub struct AssocKindMismatchWrapInBracesSugg {
     pub hi: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(hir_analysis_assoc_item_is_private, code = E0624)]
+pub struct AssocItemIsPrivate {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    pub kind: &'static str,
+    pub name: Ident,
+    #[label(hir_analysis_defined_here_label)]
+    pub defined_here_label: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(hir_analysis_assoc_item_not_found, code = E0220)]
 pub struct AssocItemNotFound<'a> {

compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs

@@ -294,30 +294,15 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             )?
         };
 
-        let (assoc_ident, def_scope) =
-            tcx.adjust_ident_and_get_scope(constraint.ident, candidate.def_id(), hir_ref_id);
-
-        // We have already adjusted the item name above, so compare with `.normalize_to_macros_2_0()`
-        // instead of calling `filter_by_name_and_kind` which would needlessly normalize the
-        // `assoc_ident` again and again.
-        let assoc_item = tcx
-            .associated_items(candidate.def_id())
-            .filter_by_name_unhygienic(assoc_ident.name)
-            .find(|i| i.kind == assoc_kind && i.ident(tcx).normalize_to_macros_2_0() == assoc_ident)
-            .expect("missing associated item");
-
-        if !assoc_item.visibility(tcx).is_accessible_from(def_scope, tcx) {
-            let reported = tcx
-                .dcx()
-                .struct_span_err(
-                    constraint.span,
-                    format!("{} `{}` is private", assoc_item.kind, constraint.ident),
-                )
-                .with_span_label(constraint.span, format!("private {}", assoc_item.kind))
-                .emit();
-            self.set_tainted_by_errors(reported);
-        }
-        tcx.check_stability(assoc_item.def_id, Some(hir_ref_id), constraint.span, None);
+        let assoc_item = self
+            .probe_assoc_item(
+                constraint.ident,
+                assoc_kind,
+                hir_ref_id,
+                constraint.span,
+                candidate.def_id(),
+            )
+            .expect("failed to find associated item");
 
         duplicates
             .entry(assoc_item.def_id)
@@ -404,10 +389,9 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             // Create the generic arguments for the associated type or constant by joining the
             // parent arguments (the arguments of the trait) and the own arguments (the ones of
             // the associated item itself) and construct an alias type using them.
-            let alias_ty = candidate.map_bound(|trait_ref| {
-                let ident = Ident::new(assoc_item.name, constraint.ident.span);
+            let alias_term = candidate.map_bound(|trait_ref| {
                 let item_segment = hir::PathSegment {
-                    ident,
+                    ident: constraint.ident,
                     hir_id: constraint.hir_id,
                     res: Res::Err,
                     args: Some(constraint.gen_args),
@@ -426,15 +410,15 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             });
 
             // Provide the resolved type of the associated constant to `type_of(AnonConst)`.
-            if let hir::AssocItemConstraintKind::Equality { term: hir::Term::Const(anon_const) } =
-                constraint.kind
-            {
-                let ty = alias_ty.map_bound(|ty| tcx.type_of(ty.def_id).instantiate(tcx, ty.args));
-                let ty = check_assoc_const_binding_type(tcx, assoc_ident, ty, constraint.hir_id);
+            if let Some(anon_const) = constraint.ct() {
+                let ty = alias_term
+                    .map_bound(|alias| tcx.type_of(alias.def_id).instantiate(tcx, alias.args));
+                let ty =
+                    check_assoc_const_binding_type(tcx, constraint.ident, ty, constraint.hir_id);
                 tcx.feed_anon_const_type(anon_const.def_id, ty::EarlyBinder::bind(ty));
             }
 
-            alias_ty
+            alias_term
         };
 
         match constraint.kind {

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -1151,8 +1151,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         };
 
         let trait_did = bound.def_id();
-        let assoc_ty_did = self.probe_assoc_ty(assoc_ident, hir_ref_id, span, trait_did).unwrap();
-        let ty = self.lower_assoc_ty(span, assoc_ty_did, assoc_segment, bound);
+        let assoc_ty = self
+            .probe_assoc_item(assoc_ident, ty::AssocKind::Type, hir_ref_id, span, trait_did)
+            .expect("failed to find associated type");
+        let ty = self.lower_assoc_ty(span, assoc_ty.def_id, assoc_segment, bound);
 
         if let Some(variant_def_id) = variant_resolution {
             tcx.node_span_lint(AMBIGUOUS_ASSOCIATED_ITEMS, hir_ref_id, span, |lint| {
@@ -1168,7 +1170,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 };
 
                 could_refer_to(DefKind::Variant, variant_def_id, "");
-                could_refer_to(DefKind::AssocTy, assoc_ty_did, " also");
+                could_refer_to(DefKind::AssocTy, assoc_ty.def_id, " also");
 
                 lint.span_suggestion(
                     span,
@@ -1178,7 +1180,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 );
             });
         }
-        Ok((ty, DefKind::AssocTy, assoc_ty_did))
+        Ok((ty, DefKind::AssocTy, assoc_ty.def_id))
     }
 
     fn probe_inherent_assoc_ty(
@@ -1205,7 +1207,11 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let candidates: Vec<_> = tcx
             .inherent_impls(adt_did)?
             .iter()
-            .filter_map(|&impl_| Some((impl_, self.probe_assoc_ty_unchecked(name, block, impl_)?)))
+            .filter_map(|&impl_| {
+                let (item, scope) =
+                    self.probe_assoc_item_unchecked(name, ty::AssocKind::Type, block, impl_)?;
+                Some((impl_, (item.def_id, scope)))
+            })
             .collect();
 
         if candidates.is_empty() {
@@ -1249,7 +1255,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             },
         )?;
 
-        self.check_assoc_ty(assoc_item, name, def_scope, block, span);
+        self.check_assoc_item(assoc_item, name, def_scope, block, span);
 
         // FIXME(fmease): Currently creating throwaway `parent_args` to please
         // `lower_generic_args_of_assoc_item`. Modify the latter instead (or sth. similar) to
@@ -1336,50 +1342,69 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         }
     }
 
-    fn probe_assoc_ty(&self, name: Ident, block: HirId, span: Span, scope: DefId) -> Option<DefId> {
-        let (item, def_scope) = self.probe_assoc_ty_unchecked(name, block, scope)?;
-        self.check_assoc_ty(item, name, def_scope, block, span);
+    /// Given name and kind search for the assoc item in the provided scope and check if it's accessible[^1].
+    ///
+    /// [^1]: I.e., accessible in the provided scope wrt. visibility and stability.
+    fn probe_assoc_item(
+        &self,
+        ident: Ident,
+        kind: ty::AssocKind,
+        block: HirId,
+        span: Span,
+        scope: DefId,
+    ) -> Option<ty::AssocItem> {
+        let (item, scope) = self.probe_assoc_item_unchecked(ident, kind, block, scope)?;
+        self.check_assoc_item(item.def_id, ident, scope, block, span);
         Some(item)
     }
 
-    fn probe_assoc_ty_unchecked(
+    /// Given name and kind search for the assoc item in the provided scope
+    /// *without* checking if it's accessible[^1].
+    ///
+    /// [^1]: I.e., accessible in the provided scope wrt. visibility and stability.
+    fn probe_assoc_item_unchecked(
         &self,
-        name: Ident,
+        ident: Ident,
+        kind: ty::AssocKind,
         block: HirId,
         scope: DefId,
-    ) -> Option<(DefId, DefId)> {
+    ) -> Option<(ty::AssocItem, /*scope*/ DefId)> {
         let tcx = self.tcx();
-        let (ident, def_scope) = tcx.adjust_ident_and_get_scope(name, scope, block);
 
+        let (ident, def_scope) = tcx.adjust_ident_and_get_scope(ident, scope, block);
         // We have already adjusted the item name above, so compare with `.normalize_to_macros_2_0()`
         // instead of calling `filter_by_name_and_kind` which would needlessly normalize the
         // `ident` again and again.
-        let item = tcx.associated_items(scope).in_definition_order().find(|i| {
-            i.kind.namespace() == Namespace::TypeNS
-                && i.ident(tcx).normalize_to_macros_2_0() == ident
-        })?;
+        let item = tcx
+            .associated_items(scope)
+            .filter_by_name_unhygienic(ident.name)
+            .find(|i| i.kind == kind && i.ident(tcx).normalize_to_macros_2_0() == ident)?;
 
-        Some((item.def_id, def_scope))
+        Some((*item, def_scope))
     }
 
-    fn check_assoc_ty(&self, item: DefId, name: Ident, def_scope: DefId, block: HirId, span: Span) {
+    /// Check if the given assoc item is accessible in the provided scope wrt. visibility and stability.
+    fn check_assoc_item(
+        &self,
+        item_def_id: DefId,
+        ident: Ident,
+        scope: DefId,
+        block: HirId,
+        span: Span,
+    ) {
         let tcx = self.tcx();
-        let kind = DefKind::AssocTy;
 
-        if !tcx.visibility(item).is_accessible_from(def_scope, tcx) {
-            let kind = tcx.def_kind_descr(kind, item);
-            let msg = format!("{kind} `{name}` is private");
-            let def_span = tcx.def_span(item);
-            let reported = tcx
-                .dcx()
-                .struct_span_err(span, msg)
-                .with_code(E0624)
-                .with_span_label(span, format!("private {kind}"))
-                .with_span_label(def_span, format!("{kind} defined here"))
-                .emit();
+        if !tcx.visibility(item_def_id).is_accessible_from(scope, tcx) {
+            let reported = tcx.dcx().emit_err(crate::errors::AssocItemIsPrivate {
+                span,
+                kind: tcx.def_descr(item_def_id),
+                name: ident,
+                defined_here_label: tcx.def_span(item_def_id),
+            });
             self.set_tainted_by_errors(reported);
         }
-        tcx.check_stability(item, Some(block), span, None);
+
+        tcx.check_stability(item_def_id, Some(block), span, None);
     }
 
     fn probe_traits_that_match_assoc_ty(

compiler/rustc_hir_analysis/src/lib.rs

@@ -55,21 +55,23 @@ This API is completely unstable and subject to change.
 
 */
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::potential_query_instability)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
-#![allow(internal_features)]
 #![feature(control_flow_enum)]
 #![feature(if_let_guard)]
 #![feature(is_sorted)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(never_type)]
+#![feature(rustdoc_internals)]
 #![feature(slice_partition_dedup)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_hir_pretty/src/lib.rs

@@ -1,7 +1,9 @@
 //! HIR pretty-printing is layered on top of AST pretty-printing. A number of
 //! the definitions in this file have equivalents in `rustc_ast_pretty`.
 
+// tidy-alphabetical-start
 #![recursion_limit = "256"]
+// tidy-alphabetical-end
 
 use rustc_ast as ast;
 use rustc_ast::util::parser::{self, AssocOp, Fixity};

compiler/rustc_hir_typeck/src/lib.rs

@@ -1,11 +1,13 @@
+// tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
-#![feature(if_let_guard)]
-#![feature(let_chains)]
-#![feature(try_blocks)]
-#![feature(never_type)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
+#![feature(if_let_guard)]
+#![feature(let_chains)]
+#![feature(never_type)]
+#![feature(try_blocks)]
+// tidy-alphabetical-end
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_incremental/src/lib.rs

@@ -1,10 +1,12 @@
 //! Support for serializing the dep-graph and reloading it.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![deny(missing_docs)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
-#![allow(internal_features)]
+// tidy-alphabetical-end
 
 mod assert_dep_graph;
 mod errors;

compiler/rustc_index/src/lib.rs

@@ -1,9 +1,11 @@
+// tidy-alphabetical-start
+#![cfg_attr(all(feature = "nightly", test), feature(stmt_expr_attributes))]
 #![cfg_attr(
     feature = "nightly",
     feature(extend_one, min_specialization, new_uninit, step_trait, test)
 )]
-#![cfg_attr(all(feature = "nightly", test), feature(stmt_expr_attributes))]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
+// tidy-alphabetical-end
 
 pub mod bit_set;
 #[cfg(feature = "nightly")]

compiler/rustc_index_macros/src/lib.rs

@@ -1,5 +1,7 @@
-#![cfg_attr(feature = "nightly", feature(allow_internal_unstable))]
+// tidy-alphabetical-start
 #![cfg_attr(feature = "nightly", allow(internal_features))]
+#![cfg_attr(feature = "nightly", feature(allow_internal_unstable))]
+// tidy-alphabetical-end
 
 use proc_macro::TokenStream;
 

compiler/rustc_infer/src/lib.rs

@@ -12,22 +12,24 @@
 //!
 //! 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(rustdoc_internals)]
+// tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![doc(rust_logo)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(extend_one)]
-#![feature(let_chains)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(iterator_try_collect)]
+#![feature(let_chains)]
+#![feature(rustdoc_internals)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
 #![recursion_limit = "512"] // For rustdoc
+// tidy-alphabetical-end
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_interface/src/lib.rs

@@ -1,7 +1,9 @@
+// tidy-alphabetical-start
 #![feature(decl_macro)]
 #![feature(let_chains)]
 #![feature(thread_spawn_unchecked)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 mod callbacks;
 mod errors;

compiler/rustc_lexer/src/lib.rs

@@ -19,9 +19,11 @@
 //!
 //! [`rustc_parse::lexer`]: ../rustc_parse/lexer/index.html
 
+// tidy-alphabetical-start
 // We want to be able to build this crate with a stable compiler,
 // so no `#![feature]` attributes should be added.
 #![deny(unstable_features)]
+// tidy-alphabetical-end
 
 mod cursor;
 pub mod unescape;

compiler/rustc_lint/src/lib.rs

@@ -25,9 +25,10 @@
 //!
 //! This API is completely unstable and subject to change.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
 #![feature(array_windows)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
@@ -35,9 +36,10 @@
 #![feature(if_let_guard)]
 #![feature(iter_order_by)]
 #![feature(let_chains)]
-#![feature(trait_upcasting)]
 #![feature(rustc_attrs)]
-#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+#![feature(trait_upcasting)]
+// tidy-alphabetical-end
 
 mod async_fn_in_trait;
 pub mod builtin;

compiler/rustc_lint_defs/src/lib.rs

@@ -1,3 +1,4 @@
+// tidy-alphabetical-start
 pub use self::Level::*;
 use rustc_ast::node_id::NodeId;
 use rustc_ast::{AttrId, Attribute};
@@ -14,6 +15,7 @@ use rustc_span::edition::Edition;
 use rustc_span::symbol::MacroRulesNormalizedIdent;
 use rustc_span::{sym, symbol::Ident, Span, Symbol};
 use rustc_target::spec::abi::Abi;
+// tidy-alphabetical-end
 
 use serde::{Deserialize, Serialize};
 

compiler/rustc_llvm/src/lib.rs

@@ -1,7 +1,9 @@
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
-#![allow(internal_features)]
+// tidy-alphabetical-end
 
 // NOTE: This crate only exists to allow linking on mingw targets.
 

compiler/rustc_macros/src/lib.rs

@@ -1,3 +1,6 @@
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![allow(rustc::default_hash_types)]
 #![feature(allow_internal_unstable)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
@@ -5,8 +8,7 @@
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]
 #![feature(proc_macro_tracked_env)]
-#![allow(rustc::default_hash_types)]
-#![allow(internal_features)]
+// tidy-alphabetical-end
 
 use synstructure::decl_derive;
 

compiler/rustc_mir_build/src/lib.rs

@@ -1,5 +1,6 @@
 //! Construction of MIR from HIR.
 
+// tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![feature(assert_matches)]
@@ -7,6 +8,7 @@
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 mod build;
 mod check_unsafety;

compiler/rustc_mir_dataflow/src/lib.rs

@@ -1,8 +1,10 @@
+// tidy-alphabetical-start
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]
 #![feature(let_chains)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 use rustc_middle::ty;
 

compiler/rustc_mir_transform/src/lib.rs

@@ -1,8 +1,10 @@
+// tidy-alphabetical-start
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(const_type_name)]
 #![feature(cow_is_borrowed)]
 #![feature(decl_macro)]
+#![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(is_sorted)]
 #![feature(let_chains)]
@@ -12,7 +14,7 @@
 #![feature(round_char_boundary)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
-#![feature(if_let_guard)]
+// tidy-alphabetical-end
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_monomorphize/src/lib.rs

@@ -1,5 +1,7 @@
+// tidy-alphabetical-start
 #![feature(array_windows)]
 #![feature(is_sorted)]
+// tidy-alphabetical-end
 
 use rustc_hir::lang_items::LangItem;
 use rustc_middle::bug;

compiler/rustc_parse/src/lib.rs

@@ -1,5 +1,6 @@
 //! The main parser interface.
 
+// tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
@@ -9,6 +10,7 @@
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
+// tidy-alphabetical-end
 
 use rustc_ast as ast;
 use rustc_ast::token;

compiler/rustc_parse_format/src/lib.rs

@@ -4,14 +4,16 @@
 //! Parsing does not happen at runtime: structures of `std::fmt::rt` are
 //! generated instead.
 
+// tidy-alphabetical-start
+// We want to be able to build this crate with a stable compiler,
+// so no `#![feature]` attributes should be added.
+#![deny(unstable_features)]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     html_playground_url = "https://play.rust-lang.org/",
     test(attr(deny(warnings)))
 )]
-// We want to be able to build this crate with a stable compiler,
-// so no `#![feature]` attributes should be added.
-#![deny(unstable_features)]
+// tidy-alphabetical-end
 
 use rustc_lexer::unescape;
 pub use Alignment::*;

compiler/rustc_passes/src/lib.rs

@@ -4,13 +4,15 @@
 //!
 //! This API is completely unstable and subject to change.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
-#![allow(internal_features)]
 #![feature(let_chains)]
 #![feature(map_try_insert)]
+#![feature(rustdoc_internals)]
 #![feature(try_blocks)]
+// tidy-alphabetical-end
 
 use rustc_middle::query::Providers;
 

compiler/rustc_pattern_analysis/src/lib.rs

@@ -1,7 +1,9 @@
 //! Analysis of patterns, notably match exhaustiveness checking.
 
-#![allow(rustc::untranslatable_diagnostic)]
+// tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+// tidy-alphabetical-end
 
 pub mod constructor;
 #[cfg(feature = "rustc")]

compiler/rustc_privacy/src/lib.rs

@@ -1,10 +1,12 @@
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
-#![allow(internal_features)]
 #![feature(associated_type_defaults)]
-#![feature(try_blocks)]
 #![feature(let_chains)]
+#![feature(rustdoc_internals)]
+#![feature(try_blocks)]
+// tidy-alphabetical-end
 
 mod errors;
 

compiler/rustc_query_impl/src/lib.rs

@@ -1,12 +1,14 @@
 //! Support for serializing the dep-graph and reloading it.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![allow(rustc::potential_query_instability, unused_parens)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
 #![feature(min_specialization)]
 #![feature(rustc_attrs)]
-#![allow(rustc::potential_query_instability, unused_parens)]
-#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use crate::plumbing::{__rust_begin_short_backtrace, encode_all_query_results, try_mark_green};
 use crate::profiling_support::QueryKeyStringCache;

compiler/rustc_query_system/src/lib.rs

@@ -1,9 +1,11 @@
+// tidy-alphabetical-start
+#![allow(rustc::potential_query_instability, internal_features)]
 #![feature(assert_matches)]
 #![feature(core_intrinsics)]
 #![feature(hash_raw_entry)]
-#![feature(min_specialization)]
 #![feature(let_chains)]
-#![allow(rustc::potential_query_instability, internal_features)]
+#![feature(min_specialization)]
+// tidy-alphabetical-end
 
 pub mod cache;
 pub mod dep_graph;

compiler/rustc_sanitizers/src/lib.rs

@@ -1,7 +1,11 @@
-#![feature(let_chains)]
 //! Sanitizers support for the Rust compiler.
 //!
 //! This crate contains the source code for providing support for the sanitizers to the Rust
 //! compiler.
+
+// tidy-alphabetical-start
+#![feature(let_chains)]
+// tidy-alphabetical-end
+
 pub mod cfi;
 pub mod kcfi;

compiler/rustc_serialize/src/lib.rs

@@ -1,20 +1,22 @@
 //! Support code for encoding and decoding types.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![allow(rustc::internal)]
+#![cfg_attr(test, feature(test))]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     html_playground_url = "https://play.rust-lang.org/",
     test(attr(allow(unused_variables), deny(warnings)))
 )]
 #![doc(rust_logo)]
-#![allow(internal_features)]
-#![feature(rustdoc_internals)]
 #![feature(const_option)]
 #![feature(core_intrinsics)]
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(ptr_sub_ptr)]
-#![cfg_attr(test, feature(test))]
-#![allow(rustc::internal)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 pub use self::serialize::{Decodable, Decoder, Encodable, Encoder};
 

compiler/rustc_session/src/lib.rs

@@ -1,9 +1,11 @@
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![feature(iter_intersperse)]
 #![feature(let_chains)]
+#![feature(map_many_mut)]
 #![feature(option_get_or_insert_default)]
 #![feature(rustc_attrs)]
-#![feature(map_many_mut)]
-#![feature(iter_intersperse)]
-#![allow(internal_features)]
+// tidy-alphabetical-end
 
 pub mod errors;
 

compiler/rustc_smir/src/lib.rs

@@ -6,14 +6,16 @@
 //!
 //! This API is still completely unstable and subject to change.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![allow(rustc::usage_of_ty_tykind)]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(attr(allow(unused_variables), deny(warnings)))
 )]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
-#![allow(internal_features)]
-#![allow(rustc::usage_of_ty_tykind)]
+// tidy-alphabetical-end
 
 pub mod rustc_internal;
 

compiler/rustc_symbol_mangling/src/lib.rs

@@ -87,11 +87,13 @@
 //! virtually impossible. Thus, symbol hash generation exclusively relies on
 //! DefPaths which are much more robust in the face of changes to the code base.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
 #![feature(let_chains)]
-#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};

compiler/rustc_target/src/abi/call/nvptx64.rs

@@ -1,23 +1,54 @@
 use crate::abi::call::{ArgAbi, FnAbi, PassMode, Reg, Size, Uniform};
 use crate::abi::{HasDataLayout, TyAbiInterface};
 
+use super::{ArgAttribute, ArgAttributes, ArgExtension, CastTarget};
+
 fn classify_ret<Ty>(ret: &mut ArgAbi<'_, Ty>) {
-    if ret.layout.is_aggregate() && ret.layout.size.bits() > 64 {
-        ret.make_indirect();
-    } else {
-        // FIXME: this is wrong! Need to decide which ABI we really want here.
-        ret.make_direct_deprecated();
+    if ret.layout.is_aggregate() && ret.layout.is_sized() {
+        classify_aggregate(ret)
+    } else if ret.layout.size.bits() < 32 && ret.layout.is_sized() {
+        ret.extend_integer_width_to(32);
     }
 }
 
 fn classify_arg<Ty>(arg: &mut ArgAbi<'_, Ty>) {
-    if arg.layout.is_aggregate() {
-        arg.make_indirect_byval(None);
-    } else if arg.layout.size.bits() < 32 {
+    if arg.layout.is_aggregate() && arg.layout.is_sized() {
+        classify_aggregate(arg)
+    } else if arg.layout.size.bits() < 32 && arg.layout.is_sized() {
         arg.extend_integer_width_to(32);
     }
 }
 
+/// the pass mode used for aggregates in arg and ret position
+fn classify_aggregate<Ty>(arg: &mut ArgAbi<'_, Ty>) {
+    let align_bytes = arg.layout.align.abi.bytes();
+    let size = arg.layout.size;
+
+    let reg = match align_bytes {
+        1 => Reg::i8(),
+        2 => Reg::i16(),
+        4 => Reg::i32(),
+        8 => Reg::i64(),
+        16 => Reg::i128(),
+        _ => unreachable!("Align is given as power of 2 no larger than 16 bytes"),
+    };
+
+    if align_bytes == size.bytes() {
+        arg.cast_to(CastTarget {
+            prefix: [Some(reg), None, None, None, None, None, None, None],
+            rest: Uniform::new(Reg::i8(), Size::from_bytes(0)),
+            attrs: ArgAttributes {
+                regular: ArgAttribute::default(),
+                arg_ext: ArgExtension::None,
+                pointee_size: Size::ZERO,
+                pointee_align: None,
+            },
+        });
+    } else {
+        arg.cast_to(Uniform::new(reg, size));
+    }
+}
+
 fn classify_arg_kernel<'a, Ty, C>(_cx: &C, arg: &mut ArgAbi<'a, Ty>)
 where
     Ty: TyAbiInterface<'a, C> + Copy,

compiler/rustc_trait_selection/src/lib.rs

@@ -10,12 +10,12 @@
 //!
 //! 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(rustdoc_internals)]
+// tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
@@ -24,8 +24,10 @@
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(never_type)]
+#![feature(rustdoc_internals)]
 #![feature(type_alias_impl_trait)]
 #![recursion_limit = "512"] // For rustdoc
+// tidy-alphabetical-end
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -4587,6 +4587,47 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             _ => "/* value */".to_string(),
         })
     }
+
+    fn suggest_add_result_as_return_type(
+        &self,
+        obligation: &PredicateObligation<'tcx>,
+        err: &mut Diag<'_>,
+        trait_ref: ty::PolyTraitRef<'tcx>,
+    ) {
+        if ObligationCauseCode::QuestionMark != *obligation.cause.code().peel_derives() {
+            return;
+        }
+
+        let node = self.tcx.hir_node_by_def_id(obligation.cause.body_id);
+        if let hir::Node::Item(item) = node
+            && let hir::ItemKind::Fn(sig, _, body_id) = item.kind
+            && let hir::FnRetTy::DefaultReturn(ret_span) = sig.decl.output
+            && self.tcx.is_diagnostic_item(sym::FromResidual, trait_ref.def_id())
+            && let ty::Tuple(l) = trait_ref.skip_binder().args.type_at(0).kind()
+            && l.len() == 0
+            && let ty::Adt(def, _) = trait_ref.skip_binder().args.type_at(1).kind()
+            && self.tcx.is_diagnostic_item(sym::Result, def.did())
+        {
+            let body = self.tcx.hir().body(body_id);
+            let mut sugg_spans =
+                vec![(ret_span, " -> Result<(), Box<dyn std::error::Error>>".to_string())];
+
+            if let hir::ExprKind::Block(b, _) = body.value.kind
+                && b.expr.is_none()
+            {
+                sugg_spans.push((
+                    // The span will point to the closing curly brace `}` of the block.
+                    b.span.shrink_to_hi().with_lo(b.span.hi() - BytePos(1)),
+                    "\n    Ok(())\n}".to_string(),
+                ));
+            }
+            err.multipart_suggestion_verbose(
+                format!("consider adding return type"),
+                sugg_spans,
+                Applicability::MaybeIncorrect,
+            );
+        }
+    }
 }
 
 /// Add a hint to add a missing borrow or remove an unnecessary one.

compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs

@@ -611,6 +611,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                             &mut err,
                             trait_predicate,
                         );
+                        self.suggest_add_result_as_return_type(&obligation,
+                            &mut err,
+                            trait_ref);
+
                         if self.suggest_add_reference_to_arg(
                             &obligation,
                             &mut err,

compiler/rustc_traits/src/lib.rs

@@ -1,6 +1,8 @@
 //! Queries that are independent from the main solver code.
 
+// tidy-alphabetical-start
 #![recursion_limit = "256"]
+// tidy-alphabetical-end
 
 mod codegen;
 mod dropck_outlives;

compiler/rustc_transmute/src/lib.rs

@@ -1,6 +1,8 @@
+// tidy-alphabetical-start
+#![allow(unused_variables)]
 #![feature(alloc_layout_extra)]
 #![feature(never_type)]
-#![allow(unused_variables)]
+// tidy-alphabetical-end
 
 pub(crate) use rustc_data_structures::fx::{FxIndexMap as Map, FxIndexSet as Set};
 

compiler/rustc_ty_utils/src/lib.rs

@@ -4,10 +4,10 @@
 //!
 //! This API is completely unstable and subject to change.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
-#![allow(internal_features)]
 #![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
@@ -15,6 +15,8 @@
 #![feature(iterator_try_collect)]
 #![feature(let_chains)]
 #![feature(never_type)]
+#![feature(rustdoc_internals)]
+// tidy-alphabetical-end
 
 use rustc_middle::query::Providers;
 

compiler/rustc_type_ir/src/lib.rs

@@ -1,9 +1,11 @@
+// tidy-alphabetical-start
+#![allow(rustc::usage_of_ty_tykind)]
 #![cfg_attr(
     feature = "nightly",
     feature(associated_type_defaults, min_specialization, never_type, rustc_attrs, negative_impls)
 )]
-#![allow(rustc::usage_of_ty_tykind)]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
+// tidy-alphabetical-end
 
 #[cfg(feature = "nightly")]
 extern crate self as rustc_type_ir;