Auto merge of #115104 - compiler-errors:rollup-8235xz5, r=compiler-errors

Rollup of 6 pull requests

Successful merges:

 - #114959 (fix #113702 emit a proper diagnostic message for unstable lints passed from CLI)
 - #115011 (Warn on elided lifetimes in associated constants (`ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT`))
 - #115077 (Do not emit invalid suggestion in E0191 when spans overlap)
 - #115087 (Add disclaimer on size assertion macro)
 - #115090 (Always use `os-release` rather than `/lib` to detect `NixOS` (bootstrap))
 - #115101 (triagebot: add dependency licensing pings)

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

compiler/rustc_hir_analysis/src/astconv/errors.rs

@@ -597,7 +597,21 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 }
             }
         }
-        if !suggestions.is_empty() {
+        suggestions.sort_by_key(|&(span, _)| span);
+        // There are cases where one bound points to a span within another bound's span, like when
+        // you have code like the following (#115019), so we skip providing a suggestion in those
+        // cases to avoid having a malformed suggestion.
+        //
+        // pub struct Flatten<I> {
+        //     inner: <IntoIterator<Item: IntoIterator<Item: >>::IntoIterator as Item>::core,
+        //             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+        //             |                  ^^^^^^^^^^^^^^^^^^^^^
+        //             |                  |
+        //             |                  associated types `Item`, `IntoIter` must be specified
+        //             associated types `Item`, `IntoIter` must be specified
+        // }
+        let overlaps = suggestions.windows(2).any(|pair| pair[0].0.overlaps(pair[1].0));
+        if !suggestions.is_empty() && !overlaps {
             err.multipart_suggestion(
                 format!("specify the associated type{}", pluralize!(types_count)),
                 suggestions,

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -289,6 +289,7 @@ fn default_body_is_unstable(
         &tcx.sess.parse_sess,
         feature,
         rustc_feature::GateIssue::Library(issue),
+        false,
     );
 
     err.emit();

compiler/rustc_index/src/lib.rs

@@ -29,6 +29,18 @@ pub use {idx::Idx, slice::IndexSlice, vec::IndexVec};
 pub use rustc_macros::newtype_index;
 
 /// Type size assertion. The first argument is a type and the second argument is its expected size.
+///
+/// <div class="warning">
+///
+/// Emitting hard errors from size assertions like this is generally not
+/// recommended, especially in libraries, because they can cause build failures if the layout
+/// algorithm or dependencies change. Here in rustc we control the toolchain and layout algorithm,
+/// so the former is not a problem. For the latter we have a lockfile as rustc is an application and
+/// precompiled library.
+///
+/// Short version: Don't copy this macro into your own code. Use a `#[test]` instead.
+///
+/// </div>
 #[macro_export]
 macro_rules! static_assert_size {
     ($ty:ty, $size:expr) => {

compiler/rustc_lint/src/context.rs

@@ -966,6 +966,14 @@ pub trait LintContext: Sized {
                         Applicability::MachineApplicable
                     );
                 }
+                BuiltinLintDiagnostics::AssociatedConstElidedLifetime { elided, span } => {
+                    db.span_suggestion_verbose(
+                        if elided { span.shrink_to_hi() } else { span },
+                        "use the `'static` lifetime",
+                        if elided { "'static " } else { "'static" },
+                        Applicability::MachineApplicable
+                    );
+                }
             }
             // Rewrap `db`, and pass control to the user.
             decorate(db)

compiler/rustc_lint/src/levels.rs

@@ -12,7 +12,7 @@ use rustc_ast as ast;
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{DecorateLint, DiagnosticBuilder, DiagnosticMessage, MultiSpan};
-use rustc_feature::Features;
+use rustc_feature::{Features, GateIssue};
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::HirId;
@@ -24,12 +24,14 @@ use rustc_middle::lint::{
 };
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{RegisteredTools, TyCtxt};
-use rustc_session::lint::builtin::{RENAMED_AND_REMOVED_LINTS, UNKNOWN_LINTS, UNUSED_ATTRIBUTES};
 use rustc_session::lint::{
-    builtin::{self, FORBIDDEN_LINT_GROUPS, SINGLE_USE_LIFETIMES, UNFULFILLED_LINT_EXPECTATIONS},
+    builtin::{
+        self, FORBIDDEN_LINT_GROUPS, RENAMED_AND_REMOVED_LINTS, SINGLE_USE_LIFETIMES,
+        UNFULFILLED_LINT_EXPECTATIONS, UNKNOWN_LINTS, UNUSED_ATTRIBUTES,
+    },
     Level, Lint, LintExpectationId, LintId,
 };
-use rustc_session::parse::{add_feature_diagnostics, feature_err};
+use rustc_session::parse::feature_err;
 use rustc_session::Session;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
@@ -566,7 +568,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                     continue;
                 }
 
-                if self.check_gated_lint(id, DUMMY_SP) {
+                if self.check_gated_lint(id, DUMMY_SP, true) {
                     let src = LintLevelSource::CommandLine(lint_flag_val, orig_level);
                     self.insert(id, (level, src));
                 }
@@ -837,7 +839,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                             reason,
                         };
                         for &id in *ids {
-                            if self.check_gated_lint(id, attr.span) {
+                            if self.check_gated_lint(id, attr.span, false) {
                                 self.insert_spec(id, (level, src));
                             }
                         }
@@ -854,7 +856,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                                     reason,
                                 };
                                 for &id in ids {
-                                    if self.check_gated_lint(id, attr.span) {
+                                    if self.check_gated_lint(id, attr.span, false) {
                                         self.insert_spec(id, (level, src));
                                     }
                                 }
@@ -955,7 +957,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                             reason,
                         };
                         for &id in ids {
-                            if self.check_gated_lint(id, attr.span) {
+                            if self.check_gated_lint(id, attr.span, false) {
                                 self.insert_spec(id, (level, src));
                             }
                         }
@@ -1000,7 +1002,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     // FIXME only emit this once for each attribute, instead of repeating it 4 times for
     // pre-expansion lints, post-expansion lints, `shallow_lint_levels_on` and `lint_expectations`.
     #[track_caller]
-    fn check_gated_lint(&self, lint_id: LintId, span: Span) -> bool {
+    fn check_gated_lint(&self, lint_id: LintId, span: Span, lint_from_cli: bool) -> bool {
         if let Some(feature) = lint_id.lint.feature_gate {
             if !self.features.enabled(feature) {
                 let lint = builtin::UNKNOWN_LINTS;
@@ -1015,7 +1017,13 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                     |lint| {
                         lint.set_arg("name", lint_id.lint.name_lower());
                         lint.note(fluent::lint_note);
-                        add_feature_diagnostics(lint, &self.sess.parse_sess, feature);
+                        rustc_session::parse::add_feature_diagnostics_for_issue(
+                            lint,
+                            &self.sess.parse_sess,
+                            feature,
+                            GateIssue::Language,
+                            lint_from_cli,
+                        );
                         lint
                     },
                 );

compiler/rustc_lint_defs/src/builtin.rs

@@ -3376,6 +3376,7 @@ declare_lint_pass! {
         DEPRECATED_IN_FUTURE,
         DEPRECATED_WHERE_CLAUSE_LOCATION,
         DUPLICATE_MACRO_ATTRIBUTES,
+        ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT,
         ELIDED_LIFETIMES_IN_PATHS,
         EXPORTED_PRIVATE_DEPENDENCIES,
         FFI_UNWIND_CALLS,
@@ -4527,3 +4528,44 @@ declare_lint! {
         reference: "issue #114095 <https://github.com/rust-lang/rust/issues/114095>",
     };
 }
+
+declare_lint! {
+    /// The `elided_lifetimes_in_associated_constant` lint detects elided lifetimes
+    /// that were erroneously allowed in associated constants.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// #![deny(elided_lifetimes_in_associated_constant)]
+    ///
+    /// struct Foo;
+    ///
+    /// impl Foo {
+    ///     const STR: &str = "hello, world";
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Previous version of Rust
+    ///
+    /// Implicit static-in-const behavior was decided [against] for associated
+    /// constants because of ambiguity. This, however, regressed and the compiler
+    /// erroneously treats elided lifetimes in associated constants as lifetime
+    /// parameters on the impl.
+    ///
+    /// This is a [future-incompatible] lint to transition this to a
+    /// hard error in the future.
+    ///
+    /// [against]: https://github.com/rust-lang/rust/issues/38831
+    /// [future-incompatible]: ../index.md#future-incompatible-lints
+    pub ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT,
+    Warn,
+    "elided lifetimes cannot be used in associated constants in impls",
+    @future_incompatible = FutureIncompatibleInfo {
+        reason: FutureIncompatibilityReason::FutureReleaseError,
+        reference: "issue #115010 <https://github.com/rust-lang/rust/issues/115010>",
+    };
+}

compiler/rustc_lint_defs/src/lib.rs

@@ -573,6 +573,10 @@ pub enum BuiltinLintDiagnostics {
         /// The span of the unnecessarily-qualified path to remove.
         removal_span: Span,
     },
+    AssociatedConstElidedLifetime {
+        elided: bool,
+        span: Span,
+    },
 }
 
 /// Lints that are buffered up early on in the `Session` before the

compiler/rustc_resolve/src/late.rs

@@ -311,6 +311,10 @@ enum LifetimeRibKind {
     /// error on default object bounds (e.g., `Box<dyn Foo>`).
     AnonymousReportError,
 
+    /// Resolves elided lifetimes to `'static`, but gives a warning that this behavior
+    /// is a bug and will be reverted soon.
+    AnonymousWarnToStatic(NodeId),
+
     /// Signal we cannot find which should be the anonymous lifetime.
     ElisionFailure,
 
@@ -1148,6 +1152,7 @@ impl<'a: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast,
                             }
                             LifetimeRibKind::AnonymousCreateParameter { .. }
                             | LifetimeRibKind::AnonymousReportError
+                            | LifetimeRibKind::AnonymousWarnToStatic(_)
                             | LifetimeRibKind::Elided(_)
                             | LifetimeRibKind::ElisionFailure
                             | LifetimeRibKind::ConcreteAnonConst(_)
@@ -1515,6 +1520,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                                     // lifetime would be illegal.
                                     LifetimeRibKind::Item
                                     | LifetimeRibKind::AnonymousReportError
+                                    | LifetimeRibKind::AnonymousWarnToStatic(_)
                                     | LifetimeRibKind::ElisionFailure => Some(LifetimeUseSet::Many),
                                     // An anonymous lifetime is legal here, and bound to the right
                                     // place, go ahead.
@@ -1576,7 +1582,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 | LifetimeRibKind::Elided(_)
                 | LifetimeRibKind::Generics { .. }
                 | LifetimeRibKind::ElisionFailure
-                | LifetimeRibKind::AnonymousReportError => {}
+                | LifetimeRibKind::AnonymousReportError
+                | LifetimeRibKind::AnonymousWarnToStatic(_) => {}
             }
         }
 
@@ -1616,6 +1623,25 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                     self.record_lifetime_res(lifetime.id, res, elision_candidate);
                     return;
                 }
+                LifetimeRibKind::AnonymousWarnToStatic(node_id) => {
+                    self.record_lifetime_res(lifetime.id, LifetimeRes::Static, elision_candidate);
+                    let msg = if elided {
+                        "`&` without an explicit lifetime name cannot be used here"
+                    } else {
+                        "`'_` cannot be used here"
+                    };
+                    self.r.lint_buffer.buffer_lint_with_diagnostic(
+                        lint::builtin::ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT,
+                        node_id,
+                        lifetime.ident.span,
+                        msg,
+                        lint::BuiltinLintDiagnostics::AssociatedConstElidedLifetime {
+                            elided,
+                            span: lifetime.ident.span,
+                        },
+                    );
+                    return;
+                }
                 LifetimeRibKind::AnonymousReportError => {
                     let (msg, note) = if elided {
                         (
@@ -1811,7 +1837,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                     //
                     //     impl Foo for std::cell::Ref<u32> // note lack of '_
                     //     async fn foo(_: std::cell::Ref<u32>) { ... }
-                    LifetimeRibKind::AnonymousCreateParameter { report_in_path: true, .. } => {
+                    LifetimeRibKind::AnonymousCreateParameter { report_in_path: true, .. }
+                    | LifetimeRibKind::AnonymousWarnToStatic(_) => {
                         let sess = self.r.tcx.sess;
                         let mut err = rustc_errors::struct_span_err!(
                             sess,
@@ -2898,7 +2925,6 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         match &item.kind {
             AssocItemKind::Const(box ast::ConstItem { generics, ty, expr, .. }) => {
                 debug!("resolve_implementation AssocItemKind::Const");
-
                 self.with_generic_param_rib(
                     &generics.params,
                     RibKind::AssocItem,
@@ -2908,28 +2934,33 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                         kind: LifetimeBinderKind::ConstItem,
                     },
                     |this| {
-                        // If this is a trait impl, ensure the const
+                        this.with_lifetime_rib(
-                        // exists in trait
+                            LifetimeRibKind::AnonymousWarnToStatic(item.id),
-                        this.check_trait_item(
+                            |this| {
-                            item.id,
+                                // If this is a trait impl, ensure the const
-                            item.ident,
+                                // exists in trait
-                            &item.kind,
+                                this.check_trait_item(
-                            ValueNS,
+                                    item.id,
-                            item.span,
+                                    item.ident,
-                            seen_trait_items,
+                                    &item.kind,
-                            |i, s, c| ConstNotMemberOfTrait(i, s, c),
+                                    ValueNS,
-                        );
+                                    item.span,
+                                    seen_trait_items,
+                                    |i, s, c| ConstNotMemberOfTrait(i, s, c),
+                                );
 
-                        this.visit_generics(generics);
+                                this.visit_generics(generics);
-                        this.visit_ty(ty);
+                                this.visit_ty(ty);
-                        if let Some(expr) = expr {
+                                if let Some(expr) = expr {
-                            // We allow arbitrary const expressions inside of associated consts,
+                                    // We allow arbitrary const expressions inside of associated consts,
-                            // even if they are potentially not const evaluatable.
+                                    // even if they are potentially not const evaluatable.
-                            //
+                                    //
-                            // Type parameters can already be used and as associated consts are
+                                    // Type parameters can already be used and as associated consts are
-                            // not used as part of the type system, this is far less surprising.
+                                    // not used as part of the type system, this is far less surprising.
-                            this.resolve_const_body(expr, None);
+                                    this.resolve_const_body(expr, None);
-                        }
+                                }
+                            },
+                        );
                     },
                 );
             }

compiler/rustc_session/messages.ftl

@@ -8,6 +8,9 @@ session_cannot_mix_and_match_sanitizers = `-Zsanitizer={$first}` is incompatible
 session_cgu_not_recorded =
     CGU-reuse for `{$cgu_user_name}` is (mangled: `{$cgu_name}`) was not recorded
 
+session_cli_feature_diagnostic_help =
+    add `-Zcrate-attr="feature({$feature})"` to the command-line options to enable
+
 session_crate_name_does_not_match = `--crate-name` and `#[crate_name]` are required to match, but `{$s}` != `{$name}`
 
 session_crate_name_empty = crate name must not be empty

compiler/rustc_session/src/errors.rs

@@ -57,6 +57,12 @@ pub struct FeatureDiagnosticHelp {
     pub feature: Symbol,
 }
 
+#[derive(Subdiagnostic)]
+#[help(session_cli_feature_diagnostic_help)]
+pub struct CliFeatureDiagnosticHelp {
+    pub feature: Symbol,
+}
+
 #[derive(Diagnostic)]
 #[diag(session_not_circumvent_feature)]
 pub struct NotCircumventFeature;

compiler/rustc_session/src/parse.rs

@@ -2,7 +2,9 @@
 //! It also serves as an input to the parser itself.
 
 use crate::config::CheckCfg;
-use crate::errors::{FeatureDiagnosticForIssue, FeatureDiagnosticHelp, FeatureGateError};
+use crate::errors::{
+    CliFeatureDiagnosticHelp, FeatureDiagnosticForIssue, FeatureDiagnosticHelp, FeatureGateError,
+};
 use crate::lint::{
     builtin::UNSTABLE_SYNTAX_PRE_EXPANSION, BufferedEarlyLint, BuiltinLintDiagnostics, Lint, LintId,
 };
@@ -110,7 +112,7 @@ pub fn feature_err_issue(
     }
 
     let mut err = sess.create_err(FeatureGateError { span, explain: explain.into() });
-    add_feature_diagnostics_for_issue(&mut err, sess, feature, issue);
+    add_feature_diagnostics_for_issue(&mut err, sess, feature, issue, false);
     err
 }
 
@@ -139,7 +141,7 @@ pub fn feature_warn_issue(
     explain: &'static str,
 ) {
     let mut err = sess.span_diagnostic.struct_span_warn(span, explain);
-    add_feature_diagnostics_for_issue(&mut err, sess, feature, issue);
+    add_feature_diagnostics_for_issue(&mut err, sess, feature, issue, false);
 
     // Decorate this as a future-incompatibility lint as in rustc_middle::lint::struct_lint_level
     let lint = UNSTABLE_SYNTAX_PRE_EXPANSION;
@@ -158,7 +160,7 @@ pub fn feature_warn_issue(
 
 /// Adds the diagnostics for a feature to an existing error.
 pub fn add_feature_diagnostics(err: &mut Diagnostic, sess: &ParseSess, feature: Symbol) {
-    add_feature_diagnostics_for_issue(err, sess, feature, GateIssue::Language);
+    add_feature_diagnostics_for_issue(err, sess, feature, GateIssue::Language, false);
 }
 
 /// Adds the diagnostics for a feature to an existing error.
@@ -171,6 +173,7 @@ pub fn add_feature_diagnostics_for_issue(
     sess: &ParseSess,
     feature: Symbol,
     issue: GateIssue,
+    feature_from_cli: bool,
 ) {
     if let Some(n) = find_feature_issue(feature, issue) {
         err.subdiagnostic(FeatureDiagnosticForIssue { n });
@@ -178,7 +181,11 @@ pub fn add_feature_diagnostics_for_issue(
 
     // #23973: do not suggest `#![feature(...)]` if we are in beta/stable
     if sess.unstable_features.is_nightly_build() {
-        err.subdiagnostic(FeatureDiagnosticHelp { feature });
+        if feature_from_cli {
+            err.subdiagnostic(CliFeatureDiagnosticHelp { feature });
+        } else {
+            err.subdiagnostic(FeatureDiagnosticHelp { feature });
+        }
     }
 }
 

src/bootstrap/bootstrap.py

@@ -644,7 +644,7 @@ class RustBuild(object):
                 return False
 
             # If the user has asked binaries to be patched for Nix, then
-            # don't check for NixOS or `/lib`.
+            # don't check for NixOS.
             if self.get_toml("patch-binaries-for-nix", "build") == "true":
                 return True
 
@@ -652,14 +652,9 @@ class RustBuild(object):
             # The latter one does not exist on NixOS when using tmpfs as root.
             try:
                 with open("/etc/os-release", "r") as f:
-                    if not any(ln.strip() in ("ID=nixos", "ID='nixos'", 'ID="nixos"') for ln in f):
+                    return any(ln.strip() in ("ID=nixos", "ID='nixos'", 'ID="nixos"') for ln in f)
-                        return False
             except FileNotFoundError:
                 return False
-            if os.path.exists("/lib"):
-                return False
-
-            return True
 
         answer = self._should_fix_bins_and_dylibs = get_answer()
         if answer:

src/bootstrap/download.rs

@@ -105,7 +105,7 @@ impl Config {
                     matches!(l.trim(), "ID=nixos" | "ID='nixos'" | "ID=\"nixos\"")
                 }),
             };
-            is_nixos && !Path::new("/lib").exists()
+            is_nixos
         });
         if val {
             eprintln!("info: You seem to be using Nix.");

src/bootstrap/tool.rs

@@ -601,7 +601,7 @@ pub struct RustAnalyzer {
 }
 
 impl RustAnalyzer {
-    pub const ALLOW_FEATURES: &str =
+    pub const ALLOW_FEATURES: &'static str =
         "proc_macro_internals,proc_macro_diagnostic,proc_macro_span,proc_macro_span_shrink";
 }
 

src/tools/rust-analyzer/crates/test-utils/src/fixture.rs

@@ -313,7 +313,7 @@ impl FixtureWithProjectMeta {
 }
 
 impl MiniCore {
-    const RAW_SOURCE: &str = include_str!("./minicore.rs");
+    const RAW_SOURCE: &'static str = include_str!("./minicore.rs");
 
     fn has_flag(&self, flag: &str) -> bool {
         self.activated_flags.iter().any(|it| it == flag)

tests/ui/associated-consts/infer-placeholder-in-non-suggestable-pos.rs

@@ -5,6 +5,8 @@ trait Trait {
 impl Trait for () {
     const ASSOC: &dyn Fn(_) = 1i32;
     //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated constants
+    //~| WARN `&` without an explicit lifetime name cannot be used here
+    //~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 }
 
 fn main() {}

tests/ui/associated-consts/infer-placeholder-in-non-suggestable-pos.stderr

@@ -1,9 +1,23 @@
+warning: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/infer-placeholder-in-non-suggestable-pos.rs:6:18
+   |
+LL |     const ASSOC: &dyn Fn(_) = 1i32;
+   |                  ^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #115010 <https://github.com/rust-lang/rust/issues/115010>
+   = note: `#[warn(elided_lifetimes_in_associated_constant)]` on by default
+help: use the `'static` lifetime
+   |
+LL |     const ASSOC: &'static dyn Fn(_) = 1i32;
+   |                   +++++++
+
 error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated constants
   --> $DIR/infer-placeholder-in-non-suggestable-pos.rs:6:26
    |
 LL |     const ASSOC: &dyn Fn(_) = 1i32;
    |                          ^ not allowed in type signatures
 
-error: aborting due to previous error
+error: aborting due to previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0121`.

tests/ui/associated-type-bounds/overlaping-bound-suggestion.rs

@@ -0,0 +1,12 @@
+#![allow(bare_trait_objects)]
+#![feature(associated_type_bounds)]
+trait Item {
+    type Core;
+}
+pub struct Flatten<I> {
+    inner: <IntoIterator<Item: IntoIterator<Item: >>::IntoIterator as Item>::Core,
+    //~^ ERROR E0191
+    //~| ERROR E0223
+}
+
+fn main() {}

tests/ui/associated-type-bounds/overlaping-bound-suggestion.stderr

@@ -0,0 +1,24 @@
+error[E0191]: the value of the associated types `IntoIter` (from trait `IntoIterator`), `IntoIter` (from trait `IntoIterator`), `Item` (from trait `IntoIterator`), `Item` (from trait `IntoIterator`) must be specified
+  --> $DIR/overlaping-bound-suggestion.rs:7:13
+   |
+LL |     inner: <IntoIterator<Item: IntoIterator<Item: >>::IntoIterator as Item>::Core,
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |             |                  |
+   |             |                  associated types `Item`, `IntoIter` must be specified
+   |             associated types `Item`, `IntoIter` must be specified
+
+error[E0223]: ambiguous associated type
+  --> $DIR/overlaping-bound-suggestion.rs:7:13
+   |
+LL |     inner: <IntoIterator<Item: IntoIterator<Item: >>::IntoIterator as Item>::Core,
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: if there were a trait named `Example` with associated type `IntoIterator` implemented for `(dyn IntoIterator + 'static)`, you could use the fully-qualified path
+   |
+LL |     inner: <<(dyn IntoIterator + 'static) as Example>::IntoIterator as Item>::Core,
+   |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0191, E0223.
+For more information about an error, try `rustc --explain E0191`.

tests/ui/consts/assoc-const-elided-lifetime.rs

@@ -0,0 +1,19 @@
+#![deny(elided_lifetimes_in_associated_constant)]
+
+use std::marker::PhantomData;
+
+struct Foo<'a> {
+    x: PhantomData<&'a ()>,
+}
+
+impl<'a> Foo<'a> {
+    const FOO: Foo<'_> = Foo { x: PhantomData::<&()> };
+    //~^ ERROR `'_` cannot be used here
+    //~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+
+    const BAR: &() = &();
+    //~^ ERROR `&` without an explicit lifetime name cannot be used here
+    //~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+}
+
+fn main() {}

tests/ui/consts/assoc-const-elided-lifetime.stderr

@@ -0,0 +1,33 @@
+error: `'_` cannot be used here
+  --> $DIR/assoc-const-elided-lifetime.rs:10:20
+   |
+LL |     const FOO: Foo<'_> = Foo { x: PhantomData::<&()> };
+   |                    ^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #115010 <https://github.com/rust-lang/rust/issues/115010>
+note: the lint level is defined here
+  --> $DIR/assoc-const-elided-lifetime.rs:1:9
+   |
+LL | #![deny(elided_lifetimes_in_associated_constant)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: use the `'static` lifetime
+   |
+LL |     const FOO: Foo<'static> = Foo { x: PhantomData::<&()> };
+   |                    ~~~~~~~
+
+error: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/assoc-const-elided-lifetime.rs:14:16
+   |
+LL |     const BAR: &() = &();
+   |                ^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #115010 <https://github.com/rust-lang/rust/issues/115010>
+help: use the `'static` lifetime
+   |
+LL |     const BAR: &'static () = &();
+   |                 +++++++
+
+error: aborting due to 2 previous errors
+

tests/ui/unknown-unstable-lints/deny-unstable-lint-command-line.stderr

@@ -1,18 +1,18 @@
 error: unknown lint: `test_unstable_lint`
    |
    = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
    = note: requested on the command line with `-D unknown-lints`
 
 error: unknown lint: `test_unstable_lint`
    |
    = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
 
 error: unknown lint: `test_unstable_lint`
    |
    = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
 
 error: aborting due to 3 previous errors
 

tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-command-line.stderr

@@ -1,18 +1,18 @@
 warning: unknown lint: `test_unstable_lint`
    |
    = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
    = note: requested on the command line with `-W unknown-lints`
 
 warning: unknown lint: `test_unstable_lint`
    |
    = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
 
 warning: unknown lint: `test_unstable_lint`
    |
    = note: the `test_unstable_lint` lint is unstable
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+   = help: add `-Zcrate-attr="feature(test_unstable_lint)"` to the command-line options to enable
 
 warning: 3 warnings emitted
 

triagebot.toml

@@ -470,6 +470,10 @@ Otherwise, you can ignore this comment.
 [mentions."src/tools/x"]
 message = "`src/tools/x` was changed. Bump version of Cargo.toml in `src/tools/x` so tidy will suggest installing the new version."
 
+[mentions."src/tools/tidy/src/deps.rs"]
+message = "Third-party dependency whitelist may have been modified! You must ensure that any new dependencies have compatible licenses before merging."
+cc = ["@davidtwco", "@wesleywiser"]
+
 [mentions."src/bootstrap/defaults/config.compiler.toml"]
 message = "This PR changes src/bootstrap/defaults/config.compiler.toml. If appropriate, please also update `config.codegen.toml` so the defaults are in sync."
 [mentions."src/bootstrap/defaults/config.codegen.toml"]