Auto merge of #92970 - matthiaskrgr:rollup-tcx7cfb, r=matthiaskrgr

Rollup of 10 pull requests

Successful merges:

 - #92487 (Fix unclosed boxes in pretty printing of TraitAlias)
 - #92581 (ARMv6K Horizon - Enable default libraries)
 - #92619 (Add diagnostic items for macros)
 - #92635 (rustdoc: Yet more intra-doc links cleanup)
 - #92646 (feat: rustc_pass_by_value lint attribute)
 - #92706 (Clarify explicitly that BTree{Map,Set} are ordered.)
 - #92710 (Include Projections when elaborating TypeOutlives)
 - #92746 (Parse `Ty?` as `Option<Ty>` and provide structured suggestion)
 - #92792 (rustdoc: fix intra-link for generic trait impls)
 - #92814 (remove unused FIXME)

Failed merges:

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

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1357,9 +1357,7 @@ impl<'a> State<'a> {
                 self.bclose(item.span, empty);
             }
             ast::ItemKind::TraitAlias(ref generics, ref bounds) => {
-                self.head("");
+                self.head(visibility_qualified(&item.vis, "trait"));
-                self.print_visibility(&item.vis);
-                self.word_nbsp("trait");
                 self.print_ident(item.ident);
                 self.print_generic_params(&generics.params);
                 let mut real_bounds = Vec::with_capacity(bounds.len());
@@ -1377,6 +1375,8 @@ impl<'a> State<'a> {
                 self.print_type_bounds("=", &real_bounds);
                 self.print_where_clause(&generics.where_clause);
                 self.word(";");
+                self.end(); // end inner head-block
+                self.end(); // end outer head-block
             }
             ast::ItemKind::MacCall(ref mac) => {
                 self.print_mac(mac);

compiler/rustc_feature/src/builtin_attrs.rs

@@ -623,6 +623,11 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         lang, Normal, template!(NameValueStr: "name"), DuplicatesOk, lang_items,
         "language items are subject to change",
     ),
+    rustc_attr!(
+        rustc_pass_by_value, Normal,
+        template!(Word), WarnFollowing,
+        "#[rustc_pass_by_value] is used to mark types that must be passed by value instead of reference."
+    ),
     BuiltinAttribute {
         name: sym::rustc_diagnostic_item,
         type_: Normal,

compiler/rustc_hir_pretty/src/lib.rs

@@ -705,9 +705,7 @@ impl<'a> State<'a> {
                 self.bclose(item.span);
             }
             hir::ItemKind::TraitAlias(ref generics, ref bounds) => {
-                self.head("");
+                self.head(visibility_qualified(&item.vis, "trait"));
-                self.print_visibility(&item.vis);
-                self.word_nbsp("trait");
                 self.print_ident(item.ident);
                 self.print_generic_params(&generics.params);
                 let mut real_bounds = Vec::with_capacity(bounds.len());
@@ -725,6 +723,8 @@ impl<'a> State<'a> {
                 self.print_bounds("=", real_bounds);
                 self.print_where_clause(&generics.where_clause);
                 self.word(";");
+                self.end(); // end inner head-block
+                self.end(); // end outer head-block
             }
         }
         self.ann.post(self, AnnNode::Item(item))

compiler/rustc_index/src/lib.rs

@@ -9,7 +9,3 @@
 pub mod bit_set;
 pub mod interval;
 pub mod vec;
-
-// FIXME(#56935): Work around ICEs during cross-compilation.
-#[allow(unused)]
-extern crate rustc_macros;

compiler/rustc_infer/src/infer/outlives/obligations.rs

@@ -164,7 +164,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
             "cannot process registered region obligations in a snapshot"
         );
 
-        debug!("process_registered_region_obligations()");
+        debug!(?param_env, "process_registered_region_obligations()");
 
         let my_region_obligations = self.take_registered_region_obligations();
 
@@ -356,6 +356,8 @@ where
         let trait_bounds: Vec<_> =
             self.verify_bound.projection_declared_bounds_from_trait(projection_ty).collect();
 
+        debug!(?trait_bounds);
+
         // Compute the bounds we can derive from the environment. This
         // is an "approximate" match -- in some cases, these bounds
         // may not apply.

compiler/rustc_infer/src/traits/util.rs

@@ -241,10 +241,19 @@ impl<'tcx> Elaborator<'tcx> {
 
                             Component::UnresolvedInferenceVariable(_) => None,
 
-                            Component::Projection(_) | Component::EscapingProjection(_) => {
+                            Component::Projection(projection) => {
-                                // We can probably do more here. This
+                                // We might end up here if we have `Foo<<Bar as Baz>::Assoc>: 'a`.
-                                // corresponds to a case like `<T as
+                                // With this, we can deduce that `<Bar as Baz>::Assoc: 'a`.
-                                // Foo<'a>>::U: 'b`.
+                                let ty =
+                                    tcx.mk_projection(projection.item_def_id, projection.substs);
+                                Some(ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(
+                                    ty, r_min,
+                                )))
+                            }
+
+                            Component::EscapingProjection(_) => {
+                                // We might be able to do more here, but we don't
+                                // want to deal with escaping vars right now.
                                 None
                             }
                         })

compiler/rustc_lint/src/internal.rs

@@ -5,10 +5,7 @@ use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext}
 use rustc_ast as ast;
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
-use rustc_hir::{
+use rustc_hir::{GenericArg, HirId, Item, ItemKind, Node, Path, PathSegment, QPath, Ty, TyKind};
-    GenericArg, HirId, Item, ItemKind, MutTy, Mutability, Node, Path, PathSegment, QPath, Ty,
-    TyKind,
-};
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
@@ -58,13 +55,6 @@ declare_tool_lint! {
     report_in_external_macro: true
 }
 
-declare_tool_lint! {
-    pub rustc::TY_PASS_BY_REFERENCE,
-    Allow,
-    "passing `Ty` or `TyCtxt` by reference",
-    report_in_external_macro: true
-}
-
 declare_tool_lint! {
     pub rustc::USAGE_OF_QUALIFIED_TY,
     Allow,
@@ -74,7 +64,6 @@ declare_tool_lint! {
 
 declare_lint_pass!(TyTyKind => [
     USAGE_OF_TY_TYKIND,
-    TY_PASS_BY_REFERENCE,
     USAGE_OF_QUALIFIED_TY,
 ]);
 
@@ -131,26 +120,6 @@ impl<'tcx> LateLintPass<'tcx> for TyTyKind {
                     }
                 }
             }
-            TyKind::Rptr(_, MutTy { ty: inner_ty, mutbl: Mutability::Not }) => {
-                if let Some(impl_did) = cx.tcx.impl_of_method(ty.hir_id.owner.to_def_id()) {
-                    if cx.tcx.impl_trait_ref(impl_did).is_some() {
-                        return;
-                    }
-                }
-                if let Some(t) = is_ty_or_ty_ctxt(cx, &inner_ty) {
-                    cx.struct_span_lint(TY_PASS_BY_REFERENCE, ty.span, |lint| {
-                        lint.build(&format!("passing `{}` by reference", t))
-                            .span_suggestion(
-                                ty.span,
-                                "try passing by value",
-                                t,
-                                // Changing type of function argument
-                                Applicability::MaybeIncorrect,
-                            )
-                            .emit();
-                    })
-                }
-            }
             _ => {}
         }
     }

compiler/rustc_lint/src/lib.rs

@@ -56,6 +56,7 @@ mod non_ascii_idents;
 mod non_fmt_panic;
 mod nonstandard_style;
 mod noop_method_call;
+mod pass_by_value;
 mod passes;
 mod redundant_semicolon;
 mod traits;
@@ -85,6 +86,7 @@ use non_ascii_idents::*;
 use non_fmt_panic::NonPanicFmt;
 use nonstandard_style::*;
 use noop_method_call::*;
+use pass_by_value::*;
 use redundant_semicolon::*;
 use traits::*;
 use types::*;
@@ -490,6 +492,8 @@ fn register_internals(store: &mut LintStore) {
     store.register_late_pass(|| Box::new(ExistingDocKeyword));
     store.register_lints(&TyTyKind::get_lints());
     store.register_late_pass(|| Box::new(TyTyKind));
+    store.register_lints(&PassByValue::get_lints());
+    store.register_late_pass(|| Box::new(PassByValue));
     store.register_group(
         false,
         "rustc::internal",
@@ -497,8 +501,8 @@ fn register_internals(store: &mut LintStore) {
         vec![
             LintId::of(DEFAULT_HASH_TYPES),
             LintId::of(USAGE_OF_TY_TYKIND),
+            LintId::of(PASS_BY_VALUE),
             LintId::of(LINT_PASS_IMPL_WITHOUT_MACRO),
-            LintId::of(TY_PASS_BY_REFERENCE),
             LintId::of(USAGE_OF_QUALIFIED_TY),
             LintId::of(EXISTING_DOC_KEYWORD),
         ],

compiler/rustc_lint/src/pass_by_value.rs

@@ -0,0 +1,94 @@
+use crate::{LateContext, LateLintPass, LintContext};
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::def::Res;
+use rustc_hir::{GenericArg, PathSegment, QPath, TyKind};
+use rustc_middle::ty;
+use rustc_span::symbol::sym;
+
+declare_tool_lint! {
+    /// The `rustc_pass_by_value` lint marks a type with `#[rustc_pass_by_value]` requiring it to always be passed by value.
+    /// This is usually used for types that are thin wrappers around references, so there is no benefit to an extra
+    /// layer of indirection. (Example: `Ty` which is a reference to a `TyS`)
+    pub rustc::PASS_BY_VALUE,
+    Warn,
+    "pass by reference of a type flagged as `#[rustc_pass_by_value]`",
+    report_in_external_macro: true
+}
+
+declare_lint_pass!(PassByValue => [PASS_BY_VALUE]);
+
+impl<'tcx> LateLintPass<'tcx> for PassByValue {
+    fn check_ty(&mut self, cx: &LateContext<'_>, ty: &'tcx hir::Ty<'tcx>) {
+        match &ty.kind {
+            TyKind::Rptr(_, hir::MutTy { ty: inner_ty, mutbl: hir::Mutability::Not }) => {
+                if let Some(impl_did) = cx.tcx.impl_of_method(ty.hir_id.owner.to_def_id()) {
+                    if cx.tcx.impl_trait_ref(impl_did).is_some() {
+                        return;
+                    }
+                }
+                if let Some(t) = path_for_pass_by_value(cx, &inner_ty) {
+                    cx.struct_span_lint(PASS_BY_VALUE, ty.span, |lint| {
+                        lint.build(&format!("passing `{}` by reference", t))
+                            .span_suggestion(
+                                ty.span,
+                                "try passing by value",
+                                t,
+                                // Changing type of function argument
+                                Applicability::MaybeIncorrect,
+                            )
+                            .emit();
+                    })
+                }
+            }
+            _ => {}
+        }
+    }
+}
+
+fn path_for_pass_by_value(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> Option<String> {
+    if let TyKind::Path(QPath::Resolved(_, path)) = &ty.kind {
+        match path.res {
+            Res::Def(_, def_id) if cx.tcx.has_attr(def_id, sym::rustc_pass_by_value) => {
+                let name = cx.tcx.item_name(def_id).to_ident_string();
+                let path_segment = path.segments.last().unwrap();
+                return Some(format!("{}{}", name, gen_args(cx, path_segment)));
+            }
+            Res::SelfTy(None, Some((did, _))) => {
+                if let ty::Adt(adt, substs) = cx.tcx.type_of(did).kind() {
+                    if cx.tcx.has_attr(adt.did, sym::rustc_pass_by_value) {
+                        return Some(cx.tcx.def_path_str_with_substs(adt.did, substs));
+                    }
+                }
+            }
+            _ => (),
+        }
+    }
+
+    None
+}
+
+fn gen_args(cx: &LateContext<'_>, segment: &PathSegment<'_>) -> String {
+    if let Some(args) = &segment.args {
+        let params = args
+            .args
+            .iter()
+            .map(|arg| match arg {
+                GenericArg::Lifetime(lt) => lt.name.ident().to_string(),
+                GenericArg::Type(ty) => {
+                    cx.tcx.sess.source_map().span_to_snippet(ty.span).unwrap_or_default()
+                }
+                GenericArg::Const(c) => {
+                    cx.tcx.sess.source_map().span_to_snippet(c.span).unwrap_or_default()
+                }
+                GenericArg::Infer(_) => String::from("_"),
+            })
+            .collect::<Vec<_>>();
+
+        if !params.is_empty() {
+            return format!("<{}>", params.join(", "));
+        }
+    }
+
+    String::new()
+}

compiler/rustc_middle/src/ty/context.rs

@@ -961,6 +961,7 @@ pub struct FreeRegionInfo {
 /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/ty.html
 #[derive(Copy, Clone)]
 #[rustc_diagnostic_item = "TyCtxt"]
+#[cfg_attr(not(bootstrap), rustc_pass_by_value)]
 pub struct TyCtxt<'tcx> {
     gcx: &'tcx GlobalCtxt<'tcx>,
 }

compiler/rustc_middle/src/ty/mod.rs

@@ -464,6 +464,7 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for TyS<'tcx> {
 }
 
 #[rustc_diagnostic_item = "Ty"]
+#[cfg_attr(not(bootstrap), rustc_pass_by_value)]
 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
 
 impl ty::EarlyBoundRegion {

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -1,5 +1,5 @@
 use super::pat::Expected;
-use super::ty::AllowPlus;
+use super::ty::{AllowPlus, IsAsCast};
 use super::{
     BlockMode, Parser, PathStyle, RecoverColon, RecoverComma, Restrictions, SemiColonMode, SeqSep,
     TokenExpectType, TokenType,
@@ -1032,6 +1032,34 @@ impl<'a> Parser<'a> {
         }
     }
 
+    /// Swift lets users write `Ty?` to mean `Option<Ty>`. Parse the construct and recover from it.
+    pub(super) fn maybe_recover_from_question_mark(
+        &mut self,
+        ty: P<Ty>,
+        is_as_cast: IsAsCast,
+    ) -> P<Ty> {
+        if let IsAsCast::Yes = is_as_cast {
+            return ty;
+        }
+        if self.token == token::Question {
+            self.bump();
+            self.struct_span_err(self.prev_token.span, "invalid `?` in type")
+                .span_label(self.prev_token.span, "`?` is only allowed on expressions, not types")
+                .multipart_suggestion(
+                    "if you meant to express that the type might not contain a value, use the `Option` wrapper type",
+                    vec![
+                        (ty.span.shrink_to_lo(), "Option<".to_string()),
+                        (self.prev_token.span, ">".to_string()),
+                    ],
+                    Applicability::MachineApplicable,
+                )
+                .emit();
+            self.mk_ty(ty.span.to(self.prev_token.span), TyKind::Err)
+        } else {
+            ty
+        }
+    }
+
     pub(super) fn maybe_recover_from_bad_type_plus(
         &mut self,
         allow_plus: AllowPlus,

compiler/rustc_parse/src/parser/expr.rs

@@ -682,7 +682,7 @@ impl<'a> Parser<'a> {
         // Save the state of the parser before parsing type normally, in case there is a
         // LessThan comparison after this cast.
         let parser_snapshot_before_type = self.clone();
-        let cast_expr = match self.parse_ty_no_plus() {
+        let cast_expr = match self.parse_as_cast_ty() {
             Ok(rhs) => mk_expr(self, lhs, rhs),
             Err(mut type_err) => {
                 // Rewind to before attempting to parse the type with generics, to recover
@@ -808,7 +808,7 @@ impl<'a> Parser<'a> {
                 "casts cannot be followed by {}",
                 match with_postfix.kind {
                     ExprKind::Index(_, _) => "indexing",
-                    ExprKind::Try(_) => "?",
+                    ExprKind::Try(_) => "`?`",
                     ExprKind::Field(_, _) => "a field access",
                     ExprKind::MethodCall(_, _, _) => "a method call",
                     ExprKind::Call(_, _) => "a function call",

compiler/rustc_parse/src/parser/ty.rs

@@ -44,6 +44,11 @@ pub(super) enum RecoverQPath {
     No,
 }
 
+pub(super) enum IsAsCast {
+    Yes,
+    No,
+}
+
 /// Signals whether parsing a type should recover `->`.
 ///
 /// More specifically, when parsing a function like:
@@ -100,6 +105,7 @@ impl<'a> Parser<'a> {
             RecoverQPath::Yes,
             RecoverReturnSign::Yes,
             None,
+            IsAsCast::No,
         )
     }
 
@@ -113,6 +119,7 @@ impl<'a> Parser<'a> {
             RecoverQPath::Yes,
             RecoverReturnSign::Yes,
             Some(ty_params),
+            IsAsCast::No,
         )
     }
 
@@ -126,6 +133,7 @@ impl<'a> Parser<'a> {
             RecoverQPath::Yes,
             RecoverReturnSign::Yes,
             None,
+            IsAsCast::No,
         )
     }
 
@@ -142,9 +150,22 @@ impl<'a> Parser<'a> {
             RecoverQPath::Yes,
             RecoverReturnSign::Yes,
             None,
+            IsAsCast::No,
         )
     }
 
+    /// Parses a type following an `as` cast. Similar to `parse_ty_no_plus`, but signaling origin
+    /// for better diagnostics involving `?`.
+    pub(super) fn parse_as_cast_ty(&mut self) -> PResult<'a, P<Ty>> {
+        self.parse_ty_common(
+            AllowPlus::No,
+            AllowCVariadic::No,
+            RecoverQPath::Yes,
+            RecoverReturnSign::Yes,
+            None,
+            IsAsCast::Yes,
+        )
+    }
     /// Parse a type without recovering `:` as `->` to avoid breaking code such as `where fn() : for<'a>`
     pub(super) fn parse_ty_for_where_clause(&mut self) -> PResult<'a, P<Ty>> {
         self.parse_ty_common(
@@ -153,6 +174,7 @@ impl<'a> Parser<'a> {
             RecoverQPath::Yes,
             RecoverReturnSign::OnlyFatArrow,
             None,
+            IsAsCast::No,
         )
     }
 
@@ -171,6 +193,7 @@ impl<'a> Parser<'a> {
                 recover_qpath,
                 recover_return_sign,
                 None,
+                IsAsCast::No,
             )?;
             FnRetTy::Ty(ty)
         } else if recover_return_sign.can_recover(&self.token.kind) {
@@ -191,6 +214,7 @@ impl<'a> Parser<'a> {
                 recover_qpath,
                 recover_return_sign,
                 None,
+                IsAsCast::No,
             )?;
             FnRetTy::Ty(ty)
         } else {
@@ -205,6 +229,7 @@ impl<'a> Parser<'a> {
         recover_qpath: RecoverQPath,
         recover_return_sign: RecoverReturnSign,
         ty_generics: Option<&Generics>,
+        is_as_cast: IsAsCast,
     ) -> PResult<'a, P<Ty>> {
         let allow_qpath_recovery = recover_qpath == RecoverQPath::Yes;
         maybe_recover_from_interpolated_ty_qpath!(self, allow_qpath_recovery);
@@ -280,6 +305,7 @@ impl<'a> Parser<'a> {
         // Try to recover from use of `+` with incorrect priority.
         self.maybe_report_ambiguous_plus(allow_plus, impl_dyn_multi, &ty);
         self.maybe_recover_from_bad_type_plus(allow_plus, &ty)?;
+        let ty = self.maybe_recover_from_question_mark(ty, is_as_cast);
         self.maybe_recover_from_bad_qpath(ty, allow_qpath_recovery)
     }
 

compiler/rustc_passes/src/check_attr.rs

@@ -114,6 +114,7 @@ impl CheckAttrVisitor<'_> {
                 }
                 sym::must_not_suspend => self.check_must_not_suspend(&attr, span, target),
                 sym::must_use => self.check_must_use(hir_id, &attr, span, target),
+                sym::rustc_pass_by_value => self.check_pass_by_value(&attr, span, target),
                 sym::rustc_const_unstable
                 | sym::rustc_const_stable
                 | sym::unstable
@@ -1066,6 +1067,24 @@ impl CheckAttrVisitor<'_> {
         is_valid
     }
 
+    /// Warns against some misuses of `#[pass_by_value]`
+    fn check_pass_by_value(&self, attr: &Attribute, span: &Span, target: Target) -> bool {
+        match target {
+            Target::Struct | Target::Enum | Target::TyAlias => true,
+            _ => {
+                self.tcx
+                    .sess
+                    .struct_span_err(
+                        attr.span,
+                        "`pass_by_value` attribute should be applied to a struct, enum or type alias.",
+                    )
+                    .span_label(*span, "is not a struct, enum or type alias")
+                    .emit();
+                false
+            }
+        }
+    }
+
     /// Warns against some misuses of `#[must_use]`
     fn check_must_use(
         &self,

compiler/rustc_span/src/symbol.rs

@@ -336,8 +336,10 @@ symbols! {
         asm_sym,
         asm_unwind,
         assert,
+        assert_eq_macro,
         assert_inhabited,
         assert_macro,
+        assert_ne_macro,
         assert_receiver_is_total_eq,
         assert_uninit_valid,
         assert_zero_valid,
@@ -407,6 +409,7 @@ symbols! {
         cfg_doctest,
         cfg_eval,
         cfg_hide,
+        cfg_macro,
         cfg_panic,
         cfg_sanitize,
         cfg_target_abi,
@@ -434,15 +437,18 @@ symbols! {
         coerce_unsized,
         cold,
         column,
+        column_macro,
         compare_and_swap,
         compare_exchange,
         compare_exchange_weak,
         compile_error,
+        compile_error_macro,
         compiler_builtins,
         compiler_fence,
         concat,
         concat_bytes,
         concat_idents,
+        concat_macro,
         conservative_impl_trait,
         console,
         const_allocate,
@@ -522,10 +528,13 @@ symbols! {
         custom_inner_attributes,
         custom_test_frameworks,
         d,
+        dbg_macro,
         dead_code,
         dealloc,
         debug,
+        debug_assert_eq_macro,
         debug_assert_macro,
+        debug_assert_ne_macro,
         debug_assertions,
         debug_struct,
         debug_trait_builder,
@@ -597,6 +606,9 @@ symbols! {
         encode,
         end,
         env,
+        env_macro,
+        eprint_macro,
+        eprintln_macro,
         eq,
         ermsb_target_feature,
         exact_div,
@@ -644,6 +656,7 @@ symbols! {
         field,
         field_init_shorthand,
         file,
+        file_macro,
         fill,
         finish,
         flags,
@@ -666,6 +679,7 @@ symbols! {
         format,
         format_args,
         format_args_capture,
+        format_args_macro,
         format_args_nl,
         format_macro,
         freeze,
@@ -732,7 +746,10 @@ symbols! {
         in_band_lifetimes,
         include,
         include_bytes,
+        include_bytes_macro,
+        include_macro,
         include_str,
+        include_str_macro,
         inclusive_range_syntax,
         index,
         index_mut,
@@ -780,6 +797,7 @@ symbols! {
         lifetime,
         likely,
         line,
+        line_macro,
         link,
         link_args,
         link_cfg,
@@ -823,6 +841,7 @@ symbols! {
         masked,
         match_beginning_vert,
         match_default_bindings,
+        matches_macro,
         maxnumf32,
         maxnumf64,
         may_dangle,
@@ -859,6 +878,7 @@ symbols! {
         modifiers,
         module,
         module_path,
+        module_path_macro,
         more_qualified_paths,
         more_struct_aliases,
         movbe_target_feature,
@@ -942,6 +962,7 @@ symbols! {
         optin_builtin_traits,
         option,
         option_env,
+        option_env_macro,
         options,
         or,
         or_patterns,
@@ -1005,6 +1026,8 @@ symbols! {
         prelude_import,
         preserves_flags,
         primitive,
+        print_macro,
+        println_macro,
         proc_dash_macro: "proc-macro",
         proc_macro,
         proc_macro_attribute,
@@ -1147,6 +1170,7 @@ symbols! {
         rustc_paren_sugar,
         rustc_partition_codegened,
         rustc_partition_reused,
+        rustc_pass_by_value,
         rustc_peek,
         rustc_peek_definite_init,
         rustc_peek_liveness,
@@ -1292,6 +1316,7 @@ symbols! {
         str,
         str_alloc,
         stringify,
+        stringify_macro,
         struct_field_attributes,
         struct_inherit,
         struct_variant,
@@ -1335,6 +1360,8 @@ symbols! {
         then_with,
         thread,
         thread_local,
+        thread_local_macro,
+        todo_macro,
         tool_attributes,
         tool_lints,
         trace_macros,
@@ -1385,6 +1412,7 @@ symbols! {
         underscore_imports,
         underscore_lifetimes,
         uniform_paths,
+        unimplemented_macro,
         unit,
         universal_impl_trait,
         unix,
@@ -1393,6 +1421,7 @@ symbols! {
         unpin,
         unreachable,
         unreachable_code,
+        unreachable_macro,
         unrestricted_attribute_tokens,
         unsafe_block_in_unsafe_fn,
         unsafe_cell,
@@ -1423,6 +1452,7 @@ symbols! {
         var,
         variant_count,
         vec,
+        vec_macro,
         version,
         vis,
         visible_private_types,
@@ -1447,7 +1477,9 @@ symbols! {
         wrapping_sub,
         wreg,
         write_bytes,
+        write_macro,
         write_str,
+        writeln_macro,
         x87_reg,
         xer,
         xmm_reg,

compiler/rustc_target/src/spec/armv6k_nintendo_3ds.rs

@@ -36,6 +36,7 @@ pub fn target() -> Target {
             features: "+vfp2".to_string(),
             pre_link_args,
             exe_suffix: ".elf".to_string(),
+            no_default_libraries: false,
             ..Default::default()
         },
     }

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -206,7 +206,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             })?);
 
             if let ty::Projection(..) = placeholder_self_ty.kind() {
-                for predicate in tcx.predicates_of(def_id).instantiate_own(tcx, substs).predicates {
+                let predicates = tcx.predicates_of(def_id).instantiate_own(tcx, substs).predicates;
+                debug!(?predicates, "projection predicates");
+                for predicate in predicates {
                     let normalized = normalize_with_depth_to(
                         self,
                         obligation.param_env,

library/alloc/src/collections/btree/map.rs

@@ -34,7 +34,7 @@ pub(super) const MIN_LEN: usize = node::MIN_LEN_AFTER_SPLIT;
 // An empty map is represented either by the absence of a root node or by a
 // root node that is an empty leaf.
 
-/// A map based on a [B-Tree].
+/// An ordered map based on a [B-Tree].
 ///
 /// B-Trees represent a fundamental compromise between cache-efficiency and actually minimizing
 /// the amount of work performed in a search. In theory, a binary search tree (BST) is the optimal
@@ -68,6 +68,10 @@ pub(super) const MIN_LEN: usize = node::MIN_LEN_AFTER_SPLIT;
 /// incorrect results, aborts, memory leaks, or non-termination) but will not be undefined
 /// behavior.
 ///
+/// Iterators obtained from functions such as [`BTreeMap::iter`], [`BTreeMap::values`], or
+/// [`BTreeMap::keys`] produce their items in order by key, and take worst-case logarithmic and
+/// amortized constant time per item returned.
+///
 /// [B-Tree]: https://en.wikipedia.org/wiki/B-tree
 /// [`Cell`]: core::cell::Cell
 /// [`RefCell`]: core::cell::RefCell

library/alloc/src/collections/btree/set.rs

@@ -15,7 +15,7 @@ use super::Recover;
 
 // FIXME(conventions): implement bounded iterators
 
-/// A set based on a B-Tree.
+/// An ordered set based on a B-Tree.
 ///
 /// See [`BTreeMap`]'s documentation for a detailed discussion of this collection's performance
 /// benefits and drawbacks.
@@ -27,6 +27,9 @@ use super::Recover;
 /// incorrect results, aborts, memory leaks, or non-termination) but will not be undefined
 /// behavior.
 ///
+/// Iterators returned by [`BTreeSet::iter`] produce their items in order, and take worst-case
+/// logarithmic and amortized constant time per item returned.
+///
 /// [`Ord`]: core::cmp::Ord
 /// [`Cell`]: core::cell::Cell
 /// [`RefCell`]: core::cell::RefCell

library/alloc/src/collections/mod.rs

@@ -14,7 +14,7 @@ pub mod vec_deque;
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub mod btree_map {
-    //! A map based on a B-Tree.
+    //! An ordered map based on a B-Tree.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub use super::btree::map::*;
 }
@@ -22,7 +22,7 @@ pub mod btree_map {
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub mod btree_set {
-    //! A set based on a B-Tree.
+    //! An ordered set based on a B-Tree.
     #[stable(feature = "rust1", since = "1.0.0")]
     pub use super::btree::set::*;
 }

library/alloc/src/macros.rs

@@ -37,6 +37,7 @@
 #[cfg(not(test))]
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_diagnostic_item = "vec_macro"]
 #[allow_internal_unstable(box_syntax, liballoc_internals)]
 macro_rules! vec {
     () => (

library/core/src/macros/mod.rs

@@ -31,6 +31,7 @@ macro_rules! panic {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "assert_eq_macro")]
 #[allow_internal_unstable(core_panic)]
 macro_rules! assert_eq {
     ($left:expr, $right:expr $(,)?) => ({
@@ -80,6 +81,7 @@ macro_rules! assert_eq {
 /// ```
 #[macro_export]
 #[stable(feature = "assert_ne", since = "1.13.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "assert_ne_macro")]
 #[allow_internal_unstable(core_panic)]
 macro_rules! assert_ne {
     ($left:expr, $right:expr $(,)?) => ({
@@ -236,6 +238,7 @@ macro_rules! debug_assert {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "debug_assert_eq_macro")]
 macro_rules! debug_assert_eq {
     ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_eq!($($arg)*); })
 }
@@ -261,6 +264,7 @@ macro_rules! debug_assert_eq {
 /// ```
 #[macro_export]
 #[stable(feature = "assert_ne", since = "1.13.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "debug_assert_ne_macro")]
 macro_rules! debug_assert_ne {
     ($($arg:tt)*) => (if $crate::cfg!(debug_assertions) { $crate::assert_ne!($($arg)*); })
 }
@@ -320,6 +324,7 @@ pub macro debug_assert_matches($($arg:tt)*) {
 /// ```
 #[macro_export]
 #[stable(feature = "matches_macro", since = "1.42.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "matches_macro")]
 macro_rules! matches {
     ($expression:expr, $(|)? $( $pattern:pat_param )|+ $( if $guard: expr )? $(,)?) => {
         match $expression {
@@ -475,6 +480,7 @@ macro_rules! r#try {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "write_macro")]
 macro_rules! write {
     ($dst:expr, $($arg:tt)*) => ($dst.write_fmt($crate::format_args!($($arg)*)))
 }
@@ -525,6 +531,7 @@ macro_rules! write {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "writeln_macro")]
 #[allow_internal_unstable(format_args_nl)]
 macro_rules! writeln {
     ($dst:expr $(,)?) => (
@@ -589,6 +596,7 @@ macro_rules! writeln {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "unreachable_macro")]
 #[allow_internal_unstable(core_panic)]
 macro_rules! unreachable {
     () => ({
@@ -675,6 +683,7 @@ macro_rules! unreachable {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "unimplemented_macro")]
 #[allow_internal_unstable(core_panic)]
 macro_rules! unimplemented {
     () => ($crate::panicking::panic("not implemented"));
@@ -737,6 +746,7 @@ macro_rules! unimplemented {
 /// ```
 #[macro_export]
 #[stable(feature = "todo_macro", since = "1.40.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "todo_macro")]
 #[allow_internal_unstable(core_panic)]
 macro_rules! todo {
     () => ($crate::panicking::panic("not yet implemented"));
@@ -786,6 +796,7 @@ pub(crate) mod builtin {
     #[stable(feature = "compile_error_macro", since = "1.20.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "compile_error_macro")]
     macro_rules! compile_error {
         ($msg:expr $(,)?) => {{ /* compiler built-in */ }};
     }
@@ -835,6 +846,7 @@ pub(crate) mod builtin {
     /// assert_eq!(s, format!("hello {}", "world"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "format_args_macro")]
     #[allow_internal_unsafe]
     #[allow_internal_unstable(fmt_internals)]
     #[rustc_builtin_macro]
@@ -905,6 +917,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "env_macro")]
     macro_rules! env {
         ($name:expr $(,)?) => {{ /* compiler built-in */ }};
         ($name:expr, $error_msg:expr $(,)?) => {{ /* compiler built-in */ }};
@@ -930,6 +943,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "option_env_macro")]
     macro_rules! option_env {
         ($name:expr $(,)?) => {{ /* compiler built-in */ }};
     }
@@ -1015,6 +1029,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "concat_macro")]
     macro_rules! concat {
         ($($e:expr),* $(,)?) => {{ /* compiler built-in */ }};
     }
@@ -1040,6 +1055,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "line_macro")]
     macro_rules! line {
         () => {
             /* compiler built-in */
@@ -1079,6 +1095,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "column_macro")]
     macro_rules! column {
         () => {
             /* compiler built-in */
@@ -1104,6 +1121,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "file_macro")]
     macro_rules! file {
         () => {
             /* compiler built-in */
@@ -1128,6 +1146,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "stringify_macro")]
     macro_rules! stringify {
         ($($t:tt)*) => {
             /* compiler built-in */
@@ -1169,6 +1188,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "include_str_macro")]
     macro_rules! include_str {
         ($file:expr $(,)?) => {{ /* compiler built-in */ }};
     }
@@ -1208,6 +1228,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "include_bytes_macro")]
     macro_rules! include_bytes {
         ($file:expr $(,)?) => {{ /* compiler built-in */ }};
     }
@@ -1232,6 +1253,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "module_path_macro")]
     macro_rules! module_path {
         () => {
             /* compiler built-in */
@@ -1265,6 +1287,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "cfg_macro")]
     macro_rules! cfg {
         ($($cfg:tt)*) => {
             /* compiler built-in */
@@ -1315,6 +1338,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "include_macro")]
     macro_rules! include {
         ($file:expr $(,)?) => {{ /* compiler built-in */ }};
     }

library/std/src/macros.rs

@@ -57,6 +57,7 @@ macro_rules! panic {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "print_macro")]
 #[allow_internal_unstable(print_internals)]
 macro_rules! print {
     ($($arg:tt)*) => ($crate::io::_print($crate::format_args!($($arg)*)));
@@ -90,6 +91,7 @@ macro_rules! print {
 /// ```
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "println_macro")]
 #[allow_internal_unstable(print_internals, format_args_nl)]
 macro_rules! println {
     () => ($crate::print!("\n"));
@@ -121,6 +123,7 @@ macro_rules! println {
 /// ```
 #[macro_export]
 #[stable(feature = "eprint", since = "1.19.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "eprint_macro")]
 #[allow_internal_unstable(print_internals)]
 macro_rules! eprint {
     ($($arg:tt)*) => ($crate::io::_eprint($crate::format_args!($($arg)*)));
@@ -149,6 +152,7 @@ macro_rules! eprint {
 /// ```
 #[macro_export]
 #[stable(feature = "eprint", since = "1.19.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "eprintln_macro")]
 #[allow_internal_unstable(print_internals, format_args_nl)]
 macro_rules! eprintln {
     () => ($crate::eprint!("\n"));
@@ -282,6 +286,7 @@ macro_rules! eprintln {
 /// [`debug!`]: https://docs.rs/log/*/log/macro.debug.html
 /// [`log`]: https://crates.io/crates/log
 #[macro_export]
+#[cfg_attr(not(test), rustc_diagnostic_item = "dbg_macro")]
 #[stable(feature = "dbg_macro", since = "1.32.0")]
 macro_rules! dbg {
     // NOTE: We cannot use `concat!` to make a static string as a format argument

library/std/src/thread/local.rs

@@ -142,6 +142,7 @@ impl<T: 'static> fmt::Debug for LocalKey<T> {
 /// [`std::thread::LocalKey`]: crate::thread::LocalKey
 #[macro_export]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "thread_local_macro")]
 #[allow_internal_unstable(thread_local_internals)]
 macro_rules! thread_local {
     // empty (base case for the recursion)

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -6,13 +6,12 @@ use rustc_ast as ast;
 use rustc_data_structures::{fx::FxHashMap, stable_set::FxHashSet};
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_expand::base::SyntaxExtensionKind;
-use rustc_hir as hir;
 use rustc_hir::def::{
     DefKind,
     Namespace::{self, *},
     PerNS,
 };
-use rustc_hir::def_id::{CrateNum, DefId};
+use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_ID};
 use rustc_middle::ty::{DefIdTree, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug, ty};
 use rustc_resolve::ParentScope;
@@ -109,6 +108,45 @@ impl Res {
             Res::Primitive(_) => None,
         }
     }
+
+    /// Used for error reporting.
+    fn disambiguator_suggestion(self) -> Suggestion {
+        let kind = match self {
+            Res::Primitive(_) => return Suggestion::Prefix("prim"),
+            Res::Def(kind, _) => kind,
+        };
+        if kind == DefKind::Macro(MacroKind::Bang) {
+            return Suggestion::Macro;
+        } else if kind == DefKind::Fn || kind == DefKind::AssocFn {
+            return Suggestion::Function;
+        } else if kind == DefKind::Field {
+            return Suggestion::RemoveDisambiguator;
+        }
+
+        let prefix = match kind {
+            DefKind::Struct => "struct",
+            DefKind::Enum => "enum",
+            DefKind::Trait => "trait",
+            DefKind::Union => "union",
+            DefKind::Mod => "mod",
+            DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst => {
+                "const"
+            }
+            DefKind::Static => "static",
+            DefKind::Macro(MacroKind::Derive) => "derive",
+            // Now handle things that don't have a specific disambiguator
+            _ => match kind
+                .ns()
+                .expect("tried to calculate a disambiguator for a def without a namespace?")
+            {
+                Namespace::TypeNS => "type",
+                Namespace::ValueNS => "value",
+                Namespace::MacroNS => "macro",
+            },
+        };
+
+        Suggestion::Prefix(prefix)
+    }
 }
 
 impl TryFrom<ResolveRes> for Res {
@@ -346,7 +384,7 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
     /// In particular, this will return an error whenever there aren't three
     /// full path segments left in the link.
     ///
-    /// [enum struct variant]: hir::VariantData::Struct
+    /// [enum struct variant]: rustc_hir::VariantData::Struct
     fn variant_field<'path>(
         &self,
         path_str: &'path str,
@@ -667,10 +705,8 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
         }))
     }
 
-    /// Returns:
+    /// Resolve an associated item, returning its containing page's `Res`
-    /// - None if no associated item was found
+    /// and the fragment targeting the associated item on its page.
-    /// - Some((_, _, Some(_))) if an item was found and should go through a side channel
-    /// - Some((_, _, None)) otherwise
     fn resolve_associated_item(
         &mut self,
         root_res: Res,
@@ -903,7 +939,18 @@ fn traits_implemented_by<'a>(
                 ty
             );
             // Fast path: if this is a primitive simple `==` will work
-            let saw_impl = impl_type == ty;
+            // NOTE: the `match` is necessary; see #92662.
+            // this allows us to ignore generics because the user input
+            // may not include the generic placeholders
+            // e.g. this allows us to match Foo (user comment) with Foo<T> (actual type)
+            let saw_impl = impl_type == ty
+                || match (impl_type.kind(), ty.kind()) {
+                    (ty::Adt(impl_def, _), ty::Adt(ty_def, _)) => {
+                        debug!("impl def_id: {:?}, ty def_id: {:?}", impl_def.did, ty_def.did);
+                        impl_def.did == ty_def.did
+                    }
+                    _ => false,
+                };
 
             if saw_impl { Some(trait_) } else { None }
         })
@@ -958,17 +1005,7 @@ impl<'a, 'tcx> DocVisitor for LinkCollector<'a, 'tcx> {
             {
                 self.cx.tcx.parent(did)
             }
-            Some(did) => match self.cx.tcx.parent(did) {
+            Some(did) => Some(did),
-                // HACK(jynelson): `clean` marks associated types as `TypedefItem`, not as `AssocTypeItem`.
-                // Fixing this breaks `fn render_deref_methods`.
-                // As a workaround, see if the parent of the item is an `impl`; if so this must be an associated item,
-                // regardless of what rustdoc wants to call it.
-                Some(parent) => {
-                    let parent_kind = self.cx.tcx.def_kind(parent);
-                    Some(if parent_kind == DefKind::Impl { parent } else { did })
-                }
-                None => Some(did),
-            },
         };
 
         // FIXME(jynelson): this shouldn't go through stringification, rustdoc should just use the DefId directly
@@ -1277,79 +1314,9 @@ impl LinkCollector<'_, '_> {
             }
         }
 
-        let report_mismatch = |specified: Disambiguator, resolved: Disambiguator| {
-            // The resolved item did not match the disambiguator; give a better error than 'not found'
-            let msg = format!("incompatible link kind for `{}`", path_str);
-            let callback = |diag: &mut DiagnosticBuilder<'_>, sp: Option<rustc_span::Span>| {
-                let note = format!(
-                    "this link resolved to {} {}, which is not {} {}",
-                    resolved.article(),
-                    resolved.descr(),
-                    specified.article(),
-                    specified.descr()
-                );
-                if let Some(sp) = sp {
-                    diag.span_label(sp, &note);
-                } else {
-                    diag.note(&note);
-                }
-                suggest_disambiguator(resolved, diag, path_str, &ori_link.link, sp);
-            };
-            report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, callback);
-        };
-
-        let verify = |kind: DefKind, id: DefId| {
-            let (kind, id) = if let Some(UrlFragment::Item(ItemFragment(_, id))) = fragment {
-                (self.cx.tcx.def_kind(id), id)
-            } else {
-                (kind, id)
-            };
-            debug!("intra-doc link to {} resolved to {:?} (id: {:?})", path_str, res, id);
-
-            // Disallow e.g. linking to enums with `struct@`
-            debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
-            match (kind, disambiguator) {
-                | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
-                // NOTE: this allows 'method' to mean both normal functions and associated functions
-                // This can't cause ambiguity because both are in the same namespace.
-                | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
-                // These are namespaces; allow anything in the namespace to match
-                | (_, Some(Disambiguator::Namespace(_)))
-                // If no disambiguator given, allow anything
-                | (_, None)
-                // All of these are valid, so do nothing
-                => {}
-                (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
-                (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
-                    report_mismatch(specified, Disambiguator::Kind(kind));
-                    return None;
-                }
-            }
-
-            // item can be non-local e.g. when using #[doc(primitive = "pointer")]
-            if let Some((src_id, dst_id)) = id
-                .as_local()
-                // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
-                // would presumably panic if a fake `DefIndex` were passed.
-                .and_then(|dst_id| {
-                    item.def_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
-                })
-            {
-                if self.cx.tcx.privacy_access_levels(()).is_exported(src_id)
-                    && !self.cx.tcx.privacy_access_levels(()).is_exported(dst_id)
-                {
-                    privacy_error(self.cx, &diag_info, path_str);
-                }
-            }
-
-            Some(())
-        };
-
         match res {
             Res::Primitive(prim) => {
                 if let Some(UrlFragment::Item(ItemFragment(_, id))) = fragment {
-                    let kind = self.cx.tcx.def_kind(id);
-
                     // We're actually resolving an associated item of a primitive, so we need to
                     // verify the disambiguator (if any) matches the type of the associated item.
                     // This case should really follow the same flow as the `Res::Def` branch below,
@@ -1358,7 +1325,16 @@ impl LinkCollector<'_, '_> {
                     // doesn't allow statements like `use str::trim;`, making this a (hopefully)
                     // valid omission. See https://github.com/rust-lang/rust/pull/80660#discussion_r551585677
                     // for discussion on the matter.
-                    verify(kind, id)?;
+                    let kind = self.cx.tcx.def_kind(id);
+                    self.verify_disambiguator(
+                        path_str,
+                        &ori_link,
+                        kind,
+                        id,
+                        disambiguator,
+                        item,
+                        &diag_info,
+                    )?;
 
                     // FIXME: it would be nice to check that the feature gate was enabled in the original crate, not just ignore it altogether.
                     // However I'm not sure how to check that across crates.
@@ -1372,7 +1348,9 @@ impl LinkCollector<'_, '_> {
                     match disambiguator {
                         Some(Disambiguator::Primitive | Disambiguator::Namespace(_)) | None => {}
                         Some(other) => {
-                            report_mismatch(other, Disambiguator::Primitive);
+                            self.report_disambiguator_mismatch(
+                                path_str, &ori_link, other, res, &diag_info,
+                            );
                             return None;
                         }
                     }
@@ -1386,13 +1364,106 @@ impl LinkCollector<'_, '_> {
                 })
             }
             Res::Def(kind, id) => {
-                verify(kind, id)?;
+                let (kind_for_dis, id_for_dis) =
+                    if let Some(UrlFragment::Item(ItemFragment(_, id))) = fragment {
+                        (self.cx.tcx.def_kind(id), id)
+                    } else {
+                        (kind, id)
+                    };
+                self.verify_disambiguator(
+                    path_str,
+                    &ori_link,
+                    kind_for_dis,
+                    id_for_dis,
+                    disambiguator,
+                    item,
+                    &diag_info,
+                )?;
                 let id = clean::register_res(self.cx, rustc_hir::def::Res::Def(kind, id));
                 Some(ItemLink { link: ori_link.link, link_text, did: id, fragment })
             }
         }
     }
 
+    fn verify_disambiguator(
+        &self,
+        path_str: &str,
+        ori_link: &MarkdownLink,
+        kind: DefKind,
+        id: DefId,
+        disambiguator: Option<Disambiguator>,
+        item: &Item,
+        diag_info: &DiagnosticInfo<'_>,
+    ) -> Option<()> {
+        debug!("intra-doc link to {} resolved to {:?}", path_str, (kind, id));
+
+        // Disallow e.g. linking to enums with `struct@`
+        debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
+        match (kind, disambiguator) {
+                | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
+                // NOTE: this allows 'method' to mean both normal functions and associated functions
+                // This can't cause ambiguity because both are in the same namespace.
+                | (DefKind::Fn | DefKind::AssocFn, Some(Disambiguator::Kind(DefKind::Fn)))
+                // These are namespaces; allow anything in the namespace to match
+                | (_, Some(Disambiguator::Namespace(_)))
+                // If no disambiguator given, allow anything
+                | (_, None)
+                // All of these are valid, so do nothing
+                => {}
+                (actual, Some(Disambiguator::Kind(expected))) if actual == expected => {}
+                (_, Some(specified @ Disambiguator::Kind(_) | specified @ Disambiguator::Primitive)) => {
+                    self.report_disambiguator_mismatch(path_str,ori_link,specified, Res::Def(kind, id),diag_info);
+                    return None;
+                }
+            }
+
+        // item can be non-local e.g. when using #[doc(primitive = "pointer")]
+        if let Some((src_id, dst_id)) = id
+            .as_local()
+            // The `expect_def_id()` should be okay because `local_def_id_to_hir_id`
+            // would presumably panic if a fake `DefIndex` were passed.
+            .and_then(|dst_id| {
+                item.def_id.expect_def_id().as_local().map(|src_id| (src_id, dst_id))
+            })
+        {
+            if self.cx.tcx.privacy_access_levels(()).is_exported(src_id)
+                && !self.cx.tcx.privacy_access_levels(()).is_exported(dst_id)
+            {
+                privacy_error(self.cx, diag_info, path_str);
+            }
+        }
+
+        Some(())
+    }
+
+    fn report_disambiguator_mismatch(
+        &self,
+        path_str: &str,
+        ori_link: &MarkdownLink,
+        specified: Disambiguator,
+        resolved: Res,
+        diag_info: &DiagnosticInfo<'_>,
+    ) {
+        // The resolved item did not match the disambiguator; give a better error than 'not found'
+        let msg = format!("incompatible link kind for `{}`", path_str);
+        let callback = |diag: &mut DiagnosticBuilder<'_>, sp: Option<rustc_span::Span>| {
+            let note = format!(
+                "this link resolved to {} {}, which is not {} {}",
+                resolved.article(),
+                resolved.descr(),
+                specified.article(),
+                specified.descr(),
+            );
+            if let Some(sp) = sp {
+                diag.span_label(sp, &note);
+            } else {
+                diag.note(&note);
+            }
+            suggest_disambiguator(resolved, diag, path_str, &ori_link.link, sp);
+        };
+        report_diagnostic(self.cx.tcx, BROKEN_INTRA_DOC_LINKS, &msg, &diag_info, callback);
+    }
+
     fn report_rawptr_assoc_feature_gate(&self, dox: &str, ori_link: &MarkdownLink, item: &Item) {
         let span =
             super::source_span_for_markdown_range(self.cx.tcx, dox, &ori_link.range, &item.attrs)
@@ -1413,7 +1484,6 @@ impl LinkCollector<'_, '_> {
         diag: DiagnosticInfo<'_>,
         cache_resolution_failure: bool,
     ) -> Option<(Res, Option<UrlFragment>)> {
-        // Try to look up both the result and the corresponding side channel value
         if let Some(ref cached) = self.visited_links.get(&key) {
             match cached {
                 Some(cached) => {
@@ -1686,53 +1756,6 @@ impl Disambiguator {
         }
     }
 
-    fn from_res(res: Res) -> Self {
-        match res {
-            Res::Def(kind, _) => Disambiguator::Kind(kind),
-            Res::Primitive(_) => Disambiguator::Primitive,
-        }
-    }
-
-    /// Used for error reporting.
-    fn suggestion(self) -> Suggestion {
-        let kind = match self {
-            Disambiguator::Primitive => return Suggestion::Prefix("prim"),
-            Disambiguator::Kind(kind) => kind,
-            Disambiguator::Namespace(_) => panic!("display_for cannot be used on namespaces"),
-        };
-        if kind == DefKind::Macro(MacroKind::Bang) {
-            return Suggestion::Macro;
-        } else if kind == DefKind::Fn || kind == DefKind::AssocFn {
-            return Suggestion::Function;
-        } else if kind == DefKind::Field {
-            return Suggestion::RemoveDisambiguator;
-        }
-
-        let prefix = match kind {
-            DefKind::Struct => "struct",
-            DefKind::Enum => "enum",
-            DefKind::Trait => "trait",
-            DefKind::Union => "union",
-            DefKind::Mod => "mod",
-            DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst => {
-                "const"
-            }
-            DefKind::Static => "static",
-            DefKind::Macro(MacroKind::Derive) => "derive",
-            // Now handle things that don't have a specific disambiguator
-            _ => match kind
-                .ns()
-                .expect("tried to calculate a disambiguator for a def without a namespace?")
-            {
-                Namespace::TypeNS => "type",
-                Namespace::ValueNS => "value",
-                Namespace::MacroNS => "macro",
-            },
-        };
-
-        Suggestion::Prefix(prefix)
-    }
-
     fn ns(self) -> Namespace {
         match self {
             Self::Namespace(n) => n,
@@ -1754,9 +1777,9 @@ impl Disambiguator {
     fn descr(self) -> &'static str {
         match self {
             Self::Namespace(n) => n.descr(),
-            // HACK(jynelson): by looking at the source I saw the DefId we pass
+            // HACK(jynelson): the source of `DefKind::descr` only uses the DefId for
-            // for `expected.descr()` doesn't matter, since it's not a crate
+            // printing "module" vs "crate" so using the wrong ID is not a huge problem
-            Self::Kind(k) => k.descr(DefId::local(hir::def_id::DefIndex::from_usize(0))),
+            Self::Kind(k) => k.descr(CRATE_DEF_ID.to_def_id()),
             Self::Primitive => "builtin type",
         }
     }
@@ -2080,16 +2103,7 @@ fn resolution_failure(
                     ResolutionFailure::NotResolved { .. } => unreachable!("handled above"),
                     ResolutionFailure::Dummy => continue,
                     ResolutionFailure::WrongNamespace { res, expected_ns } => {
-                        if let Res::Def(kind, _) = res {
+                        suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
-                            let disambiguator = Disambiguator::Kind(kind);
-                            suggest_disambiguator(
-                                disambiguator,
-                                diag,
-                                path_str,
-                                diag_info.ori_link,
-                                sp,
-                            )
-                        }
 
                         format!(
                             "this link resolves to {}, which is not in the {} namespace",
@@ -2224,8 +2238,7 @@ fn ambiguity_error(
         }
 
         for res in candidates {
-            let disambiguator = Disambiguator::from_res(res);
+            suggest_disambiguator(res, diag, path_str, diag_info.ori_link, sp);
-            suggest_disambiguator(disambiguator, diag, path_str, diag_info.ori_link, sp);
         }
     });
 }
@@ -2233,14 +2246,14 @@ fn ambiguity_error(
 /// In case of an ambiguity or mismatched disambiguator, suggest the correct
 /// disambiguator.
 fn suggest_disambiguator(
-    disambiguator: Disambiguator,
+    res: Res,
     diag: &mut DiagnosticBuilder<'_>,
     path_str: &str,
     ori_link: &str,
     sp: Option<rustc_span::Span>,
 ) {
-    let suggestion = disambiguator.suggestion();
+    let suggestion = res.disambiguator_suggestion();
-    let help = format!("to link to the {}, {}", disambiguator.descr(), suggestion.descr());
+    let help = format!("to link to the {}, {}", res.descr(), suggestion.descr());
 
     if let Some(sp) = sp {
         let mut spans = suggestion.as_help_span(path_str, ori_link, sp);

src/test/rustdoc-ui/intra-doc/disambiguator-mismatch.rs

@@ -73,4 +73,9 @@ trait T {}
 //~^ ERROR incompatible link kind for `f`
 //~| NOTE this link resolved
 //~| HELP add parentheses
+
+/// Link to [fn@std]
+//~^ ERROR unresolved link to `std`
+//~| NOTE this link resolves to the crate `std`
+//~| HELP to link to the crate, prefix with `mod@`
 pub fn f() {}

src/test/rustdoc-ui/intra-doc/disambiguator-mismatch.stderr

@@ -138,5 +138,16 @@ LL - /// Link to [const@f]
 LL + /// Link to [f()]
    | 
 
-error: aborting due to 12 previous errors
+error: unresolved link to `std`
+  --> $DIR/disambiguator-mismatch.rs:77:14
+   |
+LL | /// Link to [fn@std]
+   |              ^^^^^^ this link resolves to the crate `std`, which is not in the value namespace
+   |
+help: to link to the crate, prefix with `mod@`
+   |
+LL | /// Link to [mod@std]
+   |              ~~~~
+
+error: aborting due to 13 previous errors
 

src/test/rustdoc/intra-doc/extern-type.rs

@@ -4,14 +4,34 @@ extern {
     pub type ExternType;
 }
 
-impl ExternType {
+pub trait T {
-    pub fn f(&self) {
+    fn test(&self) {}
+}
 
-    }
+pub trait G<N> {
+    fn g(&self, n: N) {}
+}
+
+impl ExternType {
+    pub fn f(&self) {}
+}
+
+impl T for ExternType {
+    fn test(&self) {}
+}
+
+impl G<usize> for ExternType {
+    fn g(&self, n: usize) {}
 }
 
 // @has 'extern_type/foreigntype.ExternType.html'
 // @has 'extern_type/fn.links_to_extern_type.html' \
 // 'href="foreigntype.ExternType.html#method.f"'
+// @has 'extern_type/fn.links_to_extern_type.html' \
+// 'href="foreigntype.ExternType.html#method.test"'
+// @has 'extern_type/fn.links_to_extern_type.html' \
+// 'href="foreigntype.ExternType.html#method.g"'
 /// See also [ExternType::f]
+/// See also [ExternType::test]
+/// See also [ExternType::g]
 pub fn links_to_extern_type() {}

src/test/rustdoc/intra-doc/generic-trait-impl.rs

@@ -0,0 +1,20 @@
+#![deny(rustdoc::broken_intra_doc_links)]
+
+// Test intra-doc links on trait implementations with generics
+// regression test for issue #92662
+
+use std::marker::PhantomData;
+
+pub trait Bar<T> {
+    fn bar(&self);
+}
+
+pub struct Foo<U>(PhantomData<U>);
+
+impl<T, U> Bar<T> for Foo<U> {
+    fn bar(&self) {}
+}
+
+// @has generic_trait_impl/fn.main.html '//a[@href="struct.Foo.html#method.bar"]' 'Foo::bar'
+/// link to [`Foo::bar`]
+pub fn main() {}

src/test/rustdoc/intra-doc/prim-self.rs

@@ -1,13 +1,15 @@
 #![deny(rustdoc::broken_intra_doc_links)]
+#![allow(incomplete_features)] // inherent_associated_types
 #![feature(lang_items)]
 #![feature(no_core)]
 #![feature(rustdoc_internals)]
+#![feature(inherent_associated_types)]
 #![no_core]
 
 #[lang = "usize"]
 /// [Self::f]
 /// [Self::MAX]
-// @has intra_link_prim_self/primitive.usize.html
+// @has prim_self/primitive.usize.html
 // @has - '//a[@href="primitive.usize.html#method.f"]' 'Self::f'
 // @has - '//a[@href="primitive.usize.html#associatedconstant.MAX"]' 'Self::MAX'
 impl usize {
@@ -17,10 +19,9 @@ impl usize {
     /// 10 and 2^32 are basically the same.
     pub const MAX: usize = 10;
 
-    // FIXME(#8995) uncomment this when associated types in inherent impls are supported
+    // @has - '//a[@href="primitive.usize.html#associatedtype.ME"]' 'Self::ME'
-    // @ has - '//a[@href="{{channel}}/std/primitive.usize.html#associatedtype.ME"]' 'Self::ME'
+    /// [Self::ME]
-    // / [Self::ME]
+    pub type ME = usize;
-    //pub type ME = usize;
 }
 
 #[doc(primitive = "usize")]

src/test/ui-fulldeps/internal-lints/pass_ty_by_ref.stderr

@@ -1,80 +0,0 @@
-error: passing `Ty<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:13:13
-   |
-LL |     ty_ref: &Ty<'_>,
-   |             ^^^^^^^ help: try passing by value: `Ty<'_>`
-   |
-note: the lint level is defined here
-  --> $DIR/pass_ty_by_ref.rs:4:9
-   |
-LL | #![deny(rustc::ty_pass_by_reference)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: passing `TyCtxt<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:15:18
-   |
-LL |     ty_ctxt_ref: &TyCtxt<'_>,
-   |                  ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
-
-error: passing `Ty<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:19:28
-   |
-LL | fn ty_multi_ref(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
-   |                            ^^^^^^^ help: try passing by value: `Ty<'_>`
-
-error: passing `TyCtxt<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:19:55
-   |
-LL | fn ty_multi_ref(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
-   |                                                       ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
-
-error: passing `Ty<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:26:17
-   |
-LL |         ty_ref: &Ty<'_>,
-   |                 ^^^^^^^ help: try passing by value: `Ty<'_>`
-
-error: passing `TyCtxt<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:28:22
-   |
-LL |         ty_ctxt_ref: &TyCtxt<'_>,
-   |                      ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
-
-error: passing `Ty<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:31:41
-   |
-LL |     fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>);
-   |                                         ^^^^^^^ help: try passing by value: `Ty<'_>`
-
-error: passing `TyCtxt<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:31:68
-   |
-LL |     fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>);
-   |                                                                    ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
-
-error: passing `Ty<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:53:17
-   |
-LL |         ty_ref: &Ty<'_>,
-   |                 ^^^^^^^ help: try passing by value: `Ty<'_>`
-
-error: passing `TyCtxt<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:55:22
-   |
-LL |         ty_ctxt_ref: &TyCtxt<'_>,
-   |                      ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
-
-error: passing `Ty<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:59:38
-   |
-LL |     fn ty_multi_ref_assoc(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
-   |                                      ^^^^^^^ help: try passing by value: `Ty<'_>`
-
-error: passing `TyCtxt<'_>` by reference
-  --> $DIR/pass_ty_by_ref.rs:59:65
-   |
-LL |     fn ty_multi_ref_assoc(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
-   |                                                                 ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
-
-error: aborting due to 12 previous errors
-

src/test/ui-fulldeps/internal-lints/pass_ty_by_ref_self.stderr

@@ -1,20 +0,0 @@
-error: passing `TyCtxt<'tcx>` by reference
-  --> $DIR/pass_ty_by_ref_self.rs:18:15
-   |
-LL |     fn by_ref(&self) {}
-   |               ^^^^^ help: try passing by value: `TyCtxt<'tcx>`
-   |
-note: the lint level is defined here
-  --> $DIR/pass_ty_by_ref_self.rs:8:9
-   |
-LL | #![deny(rustc::ty_pass_by_reference)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: passing `Ty<'tcx>` by reference
-  --> $DIR/pass_ty_by_ref_self.rs:31:21
-   |
-LL |     fn by_ref(self: &Ty<'tcx>) {}
-   |                     ^^^^^^^^^ help: try passing by value: `Ty<'tcx>`
-
-error: aborting due to 2 previous errors
-

src/test/ui-fulldeps/internal-lints/rustc_pass_by_value.rs

@@ -1,7 +1,8 @@
 // compile-flags: -Z unstable-options
 
+#![feature(rustc_attrs)]
 #![feature(rustc_private)]
-#![deny(rustc::ty_pass_by_reference)]
+#![deny(rustc::pass_by_value)]
 #![allow(unused)]
 
 extern crate rustc_middle;
@@ -61,4 +62,57 @@ impl Foo {
     //~^^ ERROR passing `TyCtxt<'_>` by reference
 }
 
+#[rustc_pass_by_value]
+enum CustomEnum {
+    A,
+    B,
+}
+
+impl CustomEnum {
+    fn test(
+        value: CustomEnum,
+        reference: &CustomEnum, //~ ERROR passing `CustomEnum` by reference
+    ) {
+    }
+}
+
+#[rustc_pass_by_value]
+struct CustomStruct {
+    s: u8,
+}
+
+#[rustc_pass_by_value]
+type CustomAlias<'a> = &'a CustomStruct; //~ ERROR passing `CustomStruct` by reference
+
+impl CustomStruct {
+    fn test(
+        value: CustomStruct,
+        reference: &CustomStruct, //~ ERROR passing `CustomStruct` by reference
+    ) {
+    }
+
+    fn test_alias(
+        value: CustomAlias,
+        reference: &CustomAlias, //~ ERROR passing `CustomAlias<>` by reference
+    ) {
+    }
+}
+
+#[rustc_pass_by_value]
+struct WithParameters<T, const N: usize, M = u32> {
+    slice: [T; N],
+    m: M,
+}
+
+impl<T> WithParameters<T, 1> {
+    fn test<'a>(
+        value: WithParameters<T, 1>,
+        reference: &'a WithParameters<T, 1>, //~ ERROR passing `WithParameters<T, 1>` by reference
+        reference_with_m: &WithParameters<T, 1, u32>, //~ ERROR passing `WithParameters<T, 1, u32>` by reference
+    ) -> &'a WithParameters<T, 1> {
+        //~^ ERROR passing `WithParameters<T, 1>` by reference
+        reference as &WithParameters<_, 1> //~ ERROR passing `WithParameters<_, 1>` by reference
+    }
+}
+
 fn main() {}

src/test/ui-fulldeps/internal-lints/rustc_pass_by_value.stderr

@@ -0,0 +1,128 @@
+error: passing `Ty<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:14:13
+   |
+LL |     ty_ref: &Ty<'_>,
+   |             ^^^^^^^ help: try passing by value: `Ty<'_>`
+   |
+note: the lint level is defined here
+  --> $DIR/rustc_pass_by_value.rs:5:9
+   |
+LL | #![deny(rustc::pass_by_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+error: passing `TyCtxt<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:16:18
+   |
+LL |     ty_ctxt_ref: &TyCtxt<'_>,
+   |                  ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:20:28
+   |
+LL | fn ty_multi_ref(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
+   |                            ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:20:55
+   |
+LL | fn ty_multi_ref(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
+   |                                                       ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:27:17
+   |
+LL |         ty_ref: &Ty<'_>,
+   |                 ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:29:22
+   |
+LL |         ty_ctxt_ref: &TyCtxt<'_>,
+   |                      ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:32:41
+   |
+LL |     fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>);
+   |                                         ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:32:68
+   |
+LL |     fn ty_multi_ref_in_trait(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>);
+   |                                                                    ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:54:17
+   |
+LL |         ty_ref: &Ty<'_>,
+   |                 ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:56:22
+   |
+LL |         ty_ctxt_ref: &TyCtxt<'_>,
+   |                      ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
+
+error: passing `Ty<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:60:38
+   |
+LL |     fn ty_multi_ref_assoc(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
+   |                                      ^^^^^^^ help: try passing by value: `Ty<'_>`
+
+error: passing `TyCtxt<'_>` by reference
+  --> $DIR/rustc_pass_by_value.rs:60:65
+   |
+LL |     fn ty_multi_ref_assoc(ty_multi: &&Ty<'_>, ty_ctxt_multi: &&&&TyCtxt<'_>) {}
+   |                                                                 ^^^^^^^^^^^ help: try passing by value: `TyCtxt<'_>`
+
+error: passing `CustomEnum` by reference
+  --> $DIR/rustc_pass_by_value.rs:74:20
+   |
+LL |         reference: &CustomEnum,
+   |                    ^^^^^^^^^^^ help: try passing by value: `CustomEnum`
+
+error: passing `CustomStruct` by reference
+  --> $DIR/rustc_pass_by_value.rs:85:24
+   |
+LL | type CustomAlias<'a> = &'a CustomStruct;
+   |                        ^^^^^^^^^^^^^^^^ help: try passing by value: `CustomStruct`
+
+error: passing `CustomStruct` by reference
+  --> $DIR/rustc_pass_by_value.rs:90:20
+   |
+LL |         reference: &CustomStruct,
+   |                    ^^^^^^^^^^^^^ help: try passing by value: `CustomStruct`
+
+error: passing `CustomAlias<>` by reference
+  --> $DIR/rustc_pass_by_value.rs:96:20
+   |
+LL |         reference: &CustomAlias,
+   |                    ^^^^^^^^^^^^ help: try passing by value: `CustomAlias<>`
+
+error: passing `WithParameters<T, 1>` by reference
+  --> $DIR/rustc_pass_by_value.rs:110:20
+   |
+LL |         reference: &'a WithParameters<T, 1>,
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<T, 1>`
+
+error: passing `WithParameters<T, 1, u32>` by reference
+  --> $DIR/rustc_pass_by_value.rs:111:27
+   |
+LL |         reference_with_m: &WithParameters<T, 1, u32>,
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<T, 1, u32>`
+
+error: passing `WithParameters<T, 1>` by reference
+  --> $DIR/rustc_pass_by_value.rs:112:10
+   |
+LL |     ) -> &'a WithParameters<T, 1> {
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<T, 1>`
+
+error: passing `WithParameters<_, 1>` by reference
+  --> $DIR/rustc_pass_by_value.rs:114:22
+   |
+LL |         reference as &WithParameters<_, 1>
+   |                      ^^^^^^^^^^^^^^^^^^^^^ help: try passing by value: `WithParameters<_, 1>`
+
+error: aborting due to 20 previous errors
+

src/test/ui-fulldeps/internal-lints/rustc_pass_by_value_self.rs

@@ -5,10 +5,10 @@
 // Considering that all other `internal-lints` are tested here
 // this seems like the cleaner solution though.
 #![feature(rustc_attrs)]
-#![deny(rustc::ty_pass_by_reference)]
+#![deny(rustc::pass_by_value)]
 #![allow(unused)]
 
-#[rustc_diagnostic_item = "TyCtxt"]
+#[rustc_pass_by_value]
 struct TyCtxt<'tcx> {
     inner: &'tcx (),
 }
@@ -18,12 +18,11 @@ impl<'tcx> TyCtxt<'tcx> {
     fn by_ref(&self) {} //~ ERROR passing `TyCtxt<'tcx>` by reference
 }
 
-
 struct TyS<'tcx> {
     inner: &'tcx (),
 }
 
-#[rustc_diagnostic_item = "Ty"]
+#[rustc_pass_by_value]
 type Ty<'tcx> = &'tcx TyS<'tcx>;
 
 impl<'tcx> TyS<'tcx> {
@@ -31,4 +30,25 @@ impl<'tcx> TyS<'tcx> {
     fn by_ref(self: &Ty<'tcx>) {} //~ ERROR passing `Ty<'tcx>` by reference
 }
 
+#[rustc_pass_by_value]
+struct Foo;
+
+impl Foo {
+    fn with_ref(&self) {} //~ ERROR passing `Foo` by reference
+}
+
+#[rustc_pass_by_value]
+struct WithParameters<T, const N: usize, M = u32> {
+    slice: [T; N],
+    m: M,
+}
+
+impl<T> WithParameters<T, 1> {
+    fn with_ref(&self) {} //~ ERROR passing `WithParameters<T, 1_usize>` by reference
+}
+
+impl<T> WithParameters<T, 1, u8> {
+    fn with_ref(&self) {} //~ ERROR passing `WithParameters<T, 1_usize, u8>` by reference
+}
+
 fn main() {}

src/test/ui-fulldeps/internal-lints/rustc_pass_by_value_self.stderr

@@ -0,0 +1,38 @@
+error: passing `TyCtxt<'tcx>` by reference
+  --> $DIR/rustc_pass_by_value_self.rs:18:15
+   |
+LL |     fn by_ref(&self) {}
+   |               ^^^^^ help: try passing by value: `TyCtxt<'tcx>`
+   |
+note: the lint level is defined here
+  --> $DIR/rustc_pass_by_value_self.rs:8:9
+   |
+LL | #![deny(rustc::pass_by_value)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+error: passing `Ty<'tcx>` by reference
+  --> $DIR/rustc_pass_by_value_self.rs:30:21
+   |
+LL |     fn by_ref(self: &Ty<'tcx>) {}
+   |                     ^^^^^^^^^ help: try passing by value: `Ty<'tcx>`
+
+error: passing `Foo` by reference
+  --> $DIR/rustc_pass_by_value_self.rs:37:17
+   |
+LL |     fn with_ref(&self) {}
+   |                 ^^^^^ help: try passing by value: `Foo`
+
+error: passing `WithParameters<T, 1_usize>` by reference
+  --> $DIR/rustc_pass_by_value_self.rs:47:17
+   |
+LL |     fn with_ref(&self) {}
+   |                 ^^^^^ help: try passing by value: `WithParameters<T, 1_usize>`
+
+error: passing `WithParameters<T, 1_usize, u8>` by reference
+  --> $DIR/rustc_pass_by_value_self.rs:51:17
+   |
+LL |     fn with_ref(&self) {}
+   |                 ^^^^^ help: try passing by value: `WithParameters<T, 1_usize, u8>`
+
+error: aborting due to 5 previous errors
+

src/test/ui/generic-associated-types/issue-92096.migrate.stderr

@@ -0,0 +1,18 @@
+error[E0311]: the parameter type `C` may not live long enough
+  --> $DIR/issue-92096.rs:20:33
+   |
+LL | fn call_connect<C>(c: &'_ C) -> impl '_ + Future + Send
+   |                 -               ^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `C` will meet its required lifetime bounds
+   |                 |
+   |                 help: consider adding an explicit lifetime bound...: `C: 'a`
+
+error[E0311]: the parameter type `C` may not live long enough
+  --> $DIR/issue-92096.rs:20:33
+   |
+LL | fn call_connect<C>(c: &'_ C) -> impl '_ + Future + Send
+   |                 -               ^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `C` will meet its required lifetime bounds
+   |                 |
+   |                 help: consider adding an explicit lifetime bound...: `C: 'a`
+
+error: aborting due to 2 previous errors
+

src/test/ui/generic-associated-types/issue-92096.rs

@@ -0,0 +1,29 @@
+// edition:2018
+// [nll] check-pass
+// revisions: migrate nll
+// Explicitly testing nll with revision, so ignore compare-mode=nll
+// ignore-compare-mode-nll
+
+#![cfg_attr(nll, feature(nll))]
+#![feature(generic_associated_types)]
+
+use std::future::Future;
+
+trait Client {
+    type Connecting<'a>: Future + Send
+    where
+        Self: 'a;
+
+    fn connect(&'_ self) -> Self::Connecting<'_>;
+}
+
+fn call_connect<C>(c: &'_ C) -> impl '_ + Future + Send
+//[migrate]~^ ERROR the parameter
+//[migrate]~| ERROR the parameter
+where
+    C: Client + Send + Sync,
+{
+    async move { c.connect().await }
+}
+
+fn main() {}

src/test/ui/generic-associated-types/issue-92280.rs

@@ -0,0 +1,26 @@
+// check-pass
+
+#![feature(generic_associated_types)]
+#![allow(non_camel_case_types)]
+
+trait HasAssoc {
+    type Assoc;
+}
+
+trait Iterate<S: HasAssoc> {
+    type Iter<'a>
+    where
+        Self: 'a;
+}
+
+struct KeySegment_Broken<T> {
+    key: T,
+}
+impl<S: HasAssoc> Iterate<S> for KeySegment_Broken<S::Assoc> {
+    type Iter<'a>
+    where
+        Self: 'a,
+    = ();
+}
+
+fn main() {}

src/test/ui/macros/stringify.rs

@@ -589,7 +589,7 @@ fn test_item() {
         stringify_item!(
             pub trait Trait<T> = Sized where T: 'a;
         ),
-        "", // FIXME
+        "pub trait Trait<T> = Sized where T: 'a;",
     );
 
     // ItemKind::Impl

src/test/ui/parser/issues/issue-35813-postfix-after-cast.rs

@@ -117,9 +117,9 @@ static bar2: &[i32] = &(&[1i32,2,3]: &[i32; 3][0..1]);
 
 pub fn cast_then_try() -> Result<u64,u64> {
     Err(0u64) as Result<u64,u64>?;
-    //~^ ERROR: casts cannot be followed by ?
+    //~^ ERROR: casts cannot be followed by `?`
     Err(0u64): Result<u64,u64>?;
-    //~^ ERROR: casts cannot be followed by ?
+    //~^ ERROR: casts cannot be followed by `?`
     Ok(1)
 }
 

src/test/ui/parser/issues/issue-35813-postfix-after-cast.stderr

@@ -265,7 +265,7 @@ help: try surrounding the expression in parentheses
 LL | static bar2: &[i32] = &((&[1i32,2,3]: &[i32; 3])[0..1]);
    |                         +                      +
 
-error: casts cannot be followed by ?
+error: casts cannot be followed by `?`
   --> $DIR/issue-35813-postfix-after-cast.rs:119:5
    |
 LL |     Err(0u64) as Result<u64,u64>?;
@@ -276,7 +276,7 @@ help: try surrounding the expression in parentheses
 LL |     (Err(0u64) as Result<u64,u64>)?;
    |     +                            +
 
-error: casts cannot be followed by ?
+error: casts cannot be followed by `?`
   --> $DIR/issue-35813-postfix-after-cast.rs:121:5
    |
 LL |     Err(0u64): Result<u64,u64>?;

src/test/ui/parser/issues/issue-84148-1.rs

@@ -1,4 +1,3 @@
 fn f(t:for<>t?)
-//~^ ERROR: expected parameter name
+//~^ ERROR: expected one of
-//~| ERROR: expected one of
+//~| ERROR: invalid `?` in type
-//~| ERROR: expected one of

src/test/ui/parser/issues/issue-84148-1.stderr

@@ -1,17 +1,13 @@
-error: expected parameter name, found `?`
+error: invalid `?` in type
   --> $DIR/issue-84148-1.rs:1:14
    |
 LL | fn f(t:for<>t?)
-   |              ^ expected parameter name
+   |              ^ `?` is only allowed on expressions, not types
-
-error: expected one of `(`, `)`, `+`, `,`, `::`, or `<`, found `?`
-  --> $DIR/issue-84148-1.rs:1:14
    |
-LL | fn f(t:for<>t?)
+help: if you meant to express that the type might not contain a value, use the `Option` wrapper type
-   |              ^
+   |
-   |              |
+LL | fn f(t:Option<for<>t>)
-   |              expected one of `(`, `)`, `+`, `,`, `::`, or `<`
+   |        +++++++      ~
-   |              help: missing `,`
 
 error: expected one of `->`, `where`, or `{`, found `<eof>`
   --> $DIR/issue-84148-1.rs:1:15
@@ -19,5 +15,5 @@ error: expected one of `->`, `where`, or `{`, found `<eof>`
 LL | fn f(t:for<>t?)
    |               ^ expected one of `->`, `where`, or `{`
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 

src/test/ui/parser/issues/issue-84148-2.rs

@@ -1,4 +1,3 @@
 // error-pattern: this file contains an unclosed delimiter
-// error-pattern: expected parameter name
+// error-pattern: invalid `?` in type
-// error-pattern: expected one of
 fn f(t:for<>t?

src/test/ui/parser/issues/issue-84148-2.stderr

@@ -1,31 +1,27 @@
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-84148-2.rs:4:16
+  --> $DIR/issue-84148-2.rs:3:16
    |
 LL | fn f(t:for<>t?
    |     -          ^
    |     |
    |     unclosed delimiter
 
-error: expected parameter name, found `?`
+error: invalid `?` in type
-  --> $DIR/issue-84148-2.rs:4:14
+  --> $DIR/issue-84148-2.rs:3:14
    |
 LL | fn f(t:for<>t?
-   |              ^ expected parameter name
+   |              ^ `?` is only allowed on expressions, not types
-
-error: expected one of `(`, `)`, `+`, `,`, `::`, or `<`, found `?`
-  --> $DIR/issue-84148-2.rs:4:14
    |
-LL | fn f(t:for<>t?
+help: if you meant to express that the type might not contain a value, use the `Option` wrapper type
-   |              ^
+   |
-   |              |
+LL | fn f(t:Option<for<>t>
-   |              expected one of `(`, `)`, `+`, `,`, `::`, or `<`
+   |        +++++++      ~
-   |              help: missing `,`
 
 error: expected one of `->`, `where`, or `{`, found `<eof>`
-  --> $DIR/issue-84148-2.rs:4:16
+  --> $DIR/issue-84148-2.rs:3:16
    |
 LL | fn f(t:for<>t?
    |                ^ expected one of `->`, `where`, or `{`
 
-error: aborting due to 4 previous errors
+error: aborting due to 3 previous errors
 

src/test/ui/parser/trailing-question-in-type.fixed

@@ -0,0 +1,10 @@
+// run-rustfix
+
+fn foo() -> Option<i32> { //~ ERROR invalid `?` in type
+    let x: Option<i32> = Some(1); //~ ERROR invalid `?` in type
+    x
+}
+
+fn main() {
+    let _: Option<i32> = foo();
+}

src/test/ui/parser/trailing-question-in-type.rs

@@ -0,0 +1,10 @@
+// run-rustfix
+
+fn foo() -> i32? { //~ ERROR invalid `?` in type
+    let x: i32? = Some(1); //~ ERROR invalid `?` in type
+    x
+}
+
+fn main() {
+    let _: Option<i32> = foo();
+}

src/test/ui/parser/trailing-question-in-type.stderr

@@ -0,0 +1,24 @@
+error: invalid `?` in type
+  --> $DIR/trailing-question-in-type.rs:3:16
+   |
+LL | fn foo() -> i32? {
+   |                ^ `?` is only allowed on expressions, not types
+   |
+help: if you meant to express that the type might not contain a value, use the `Option` wrapper type
+   |
+LL | fn foo() -> Option<i32> {
+   |             +++++++   ~
+
+error: invalid `?` in type
+  --> $DIR/trailing-question-in-type.rs:4:15
+   |
+LL |     let x: i32? = Some(1);
+   |               ^ `?` is only allowed on expressions, not types
+   |
+help: if you meant to express that the type might not contain a value, use the `Option` wrapper type
+   |
+LL |     let x: Option<i32> = Some(1);
+   |            +++++++   ~
+
+error: aborting due to 2 previous errors
+