Rollup of 14 pull requests

compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -261,6 +261,9 @@ impl CleanupKind {
     }
 }
 
+/// MSVC requires unwinding code to be split to a tree of *funclets*, where each funclet can only
+/// branch to itself or to its parent. Luckily, the code we generates matches this pattern.
+/// Recover that structure in an analyze pass.
 pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKind> {
     fn discover_masters<'tcx>(
         result: &mut IndexVec<mir::BasicBlock, CleanupKind>,

compiler/rustc_error_codes/src/error_codes.rs

@@ -574,7 +574,7 @@ E0791: include_str!("./error_codes/E0791.md"),
 //  E0274, // on_unimplemented #2
 //  E0278, // requirement is not satisfied
 //  E0279,
-    E0280, // requirement is not satisfied
+//  E0280, // changed to ICE
 //  E0285, // overflow evaluation builtin bounds
 //  E0296, // replaced with a generic attribute input check
 //  E0298, // cannot compare constants

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -179,16 +179,7 @@ impl IntoDiagnosticArg for type_ir::FloatTy {
 
 impl IntoDiagnosticArg for Level {
     fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
-        DiagnosticArgValue::Str(Cow::Borrowed(match self {
-            Level::Allow => "-A",
-            Level::Warn => "-W",
-            Level::ForceWarn(_) => "--force-warn",
-            Level::Deny => "-D",
-            Level::Forbid => "-F",
-            Level::Expect(_) => {
-                unreachable!("lints with the level of `expect` should not run this code");
-            }
-        }))
+        DiagnosticArgValue::Str(Cow::Borrowed(self.to_cmd_flag()))
     }
 }
 

compiler/rustc_feature/src/active.rs

@@ -374,6 +374,8 @@ declare_features! (
     (active, deprecated_safe, "1.61.0", Some(94978), None),
     /// Allows having using `suggestion` in the `#[deprecated]` attribute.
     (active, deprecated_suggestion, "1.61.0", Some(94785), None),
+    /// Controls errors in trait implementations.
+    (active, do_not_recommend, "1.67.0", Some(51992), None),
     /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
     (active, doc_auto_cfg, "1.58.0", Some(43781), None),
     /// Allows `#[doc(cfg(...))]`.

compiler/rustc_feature/src/builtin_attrs.rs

@@ -487,6 +487,9 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         experimental!(collapse_debuginfo)
     ),
 
+    // RFC 2397
+    gated!(do_not_recommend, Normal, template!(Word), WarnFollowing, experimental!(do_not_recommend)),
+
     // ==========================================================================
     // Internal attributes: Stability, deprecation, and unsafe:
     // ==========================================================================

compiler/rustc_interface/src/tests.rs

@@ -715,7 +715,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(asm_comments, true);
     tracked!(assume_incomplete_release, true);
     tracked!(binary_dep_depinfo, true);
-    tracked!(box_noalias, Some(false));
+    tracked!(box_noalias, false);
     tracked!(
         branch_protection,
         Some(BranchProtection {
@@ -754,7 +754,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(mir_enable_passes, vec![("DestProp".to_string(), false)]);
     tracked!(mir_opt_level, Some(4));
     tracked!(move_size_limit, Some(4096));
-    tracked!(mutable_noalias, Some(true));
+    tracked!(mutable_noalias, false);
     tracked!(no_generate_arange_section, true);
     tracked!(no_jump_tables, true);
     tracked!(no_link, true);

compiler/rustc_lint_defs/src/lib.rs

@@ -253,6 +253,19 @@ impl Level {
         }
     }
 
+    pub fn to_cmd_flag(self) -> &'static str {
+        match self {
+            Level::Warn => "-W",
+            Level::Deny => "-D",
+            Level::Forbid => "-F",
+            Level::Allow => "-A",
+            Level::ForceWarn(_) => "--force-warn",
+            Level::Expect(_) => {
+                unreachable!("the expect level does not have a commandline flag")
+            }
+        }
+    }
+
     pub fn is_error(self) -> bool {
         match self {
             Level::Allow | Level::Expect(_) | Level::Warn | Level::ForceWarn(_) => false,

compiler/rustc_middle/src/lint.rs

@@ -234,16 +234,7 @@ pub fn explain_lint_level_source(
             err.note_once(&format!("`#[{}({})]` on by default", level.as_str(), name));
         }
         LintLevelSource::CommandLine(lint_flag_val, orig_level) => {
-            let flag = match orig_level {
-                Level::Warn => "-W",
-                Level::Deny => "-D",
-                Level::Forbid => "-F",
-                Level::Allow => "-A",
-                Level::ForceWarn(_) => "--force-warn",
-                Level::Expect(_) => {
-                    unreachable!("the expect level does not have a commandline flag")
-                }
-            };
+            let flag = orig_level.to_cmd_flag();
             let hyphen_case_lint_name = name.replace('_', "-");
             if lint_flag_val.as_str() == name {
                 err.note_once(&format!(

compiler/rustc_session/src/options.rs

@@ -1241,7 +1241,7 @@ options! {
 
     // tidy-alphabetical-start
     allow_features: Option<Vec<String>> = (None, parse_opt_comma_list, [TRACKED],
-        "only allow the listed language features to be enabled in code (space separated)"),
+        "only allow the listed language features to be enabled in code (comma separated)"),
     always_encode_mir: bool = (false, parse_bool, [TRACKED],
         "encode MIR of all functions into the crate metadata (default: no)"),
     asm_comments: bool = (false, parse_bool, [TRACKED],
@@ -1255,7 +1255,7 @@ options! {
     binary_dep_depinfo: bool = (false, parse_bool, [TRACKED],
         "include artifacts (sysroot, crate dependencies) used during compilation in dep-info \
         (default: no)"),
-    box_noalias: Option<bool> = (None, parse_opt_bool, [TRACKED],
+    box_noalias: bool = (true, parse_bool, [TRACKED],
         "emit noalias metadata for box (default: yes)"),
     branch_protection: Option<BranchProtection> = (None, parse_branch_protection, [TRACKED],
         "set options for branch target identification and pointer authentication on AArch64"),
@@ -1437,7 +1437,7 @@ options! {
         "use line numbers relative to the function in mir pretty printing"),
     move_size_limit: Option<usize> = (None, parse_opt_number, [TRACKED],
         "the size at which the `large_assignments` lint starts to be emitted"),
-    mutable_noalias: Option<bool> = (None, parse_opt_bool, [TRACKED],
+    mutable_noalias: bool = (true, parse_bool, [TRACKED],
         "emit noalias metadata for mutable references (default: yes)"),
     nll_facts: bool = (false, parse_bool, [UNTRACKED],
         "dump facts from NLL analysis into side files (default: no)"),

compiler/rustc_span/src/symbol.rs

@@ -613,6 +613,7 @@ symbols! {
         dispatch_from_dyn,
         div,
         div_assign,
+        do_not_recommend,
         doc,
         doc_alias,
         doc_auto_cfg,

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

@@ -1102,15 +1102,19 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     }
 
                     ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
-                    | ty::PredicateKind::Clause(ty::Clause::Projection(..))
                     | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) => {
-                        let predicate = self.resolve_vars_if_possible(obligation.predicate);
-                        struct_span_err!(
-                            self.tcx.sess,
+                        span_bug!(
                             span,
-                            E0280,
-                            "the requirement `{}` is not satisfied",
-                            predicate
+                            "outlives clauses should not error outside borrowck. obligation: `{:?}`",
+                            obligation
+                        )
+                    }
+
+                    ty::PredicateKind::Clause(ty::Clause::Projection(..)) => {
+                        span_bug!(
+                            span,
+                            "projection clauses should be implied from elsewhere. obligation: `{:?}`",
+                            obligation
                         )
                     }
 

compiler/rustc_ty_utils/src/abi.rs

@@ -254,12 +254,12 @@ fn adjust_for_rust_scalar<'tcx>(
             // The aliasing rules for `Box<T>` are still not decided, but currently we emit
             // `noalias` for it. This can be turned off using an unstable flag.
             // See https://github.com/rust-lang/unsafe-code-guidelines/issues/326
-            let noalias_for_box = cx.tcx.sess.opts.unstable_opts.box_noalias.unwrap_or(true);
+            let noalias_for_box = cx.tcx.sess.opts.unstable_opts.box_noalias;
 
             // LLVM prior to version 12 had known miscompiles in the presence of noalias attributes
             // (see #54878), so it was conditionally disabled, but we don't support earlier
             // versions at all anymore. We still support turning it off using -Zmutable-noalias.
-            let noalias_mut_ref = cx.tcx.sess.opts.unstable_opts.mutable_noalias.unwrap_or(true);
+            let noalias_mut_ref = cx.tcx.sess.opts.unstable_opts.mutable_noalias;
 
             // `&mut` pointer parameters never alias other parameters,
             // or mutable global data

library/alloc/src/string.rs

@@ -2548,6 +2548,15 @@ impl ToString for char {
     }
 }
 
+#[cfg(not(no_global_oom_handling))]
+#[stable(feature = "bool_to_string_specialization", since = "CURRENT_RUSTC_VERSION")]
+impl ToString for bool {
+    #[inline]
+    fn to_string(&self) -> String {
+        String::from(if *self { "true" } else { "false" })
+    }
+}
+
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "u8_to_string_specialization", since = "1.54.0")]
 impl ToString for u8 {

library/std/src/sync/mutex/tests.rs

@@ -181,7 +181,7 @@ fn test_mutex_arc_poison() {
     let arc2 = arc.clone();
     let _ = thread::spawn(move || {
         let lock = arc2.lock().unwrap();
-        assert_eq!(*lock, 2);
+        assert_eq!(*lock, 2); // deliberate assertion failure to poison the mutex
     })
     .join();
     assert!(arc.lock().is_err());

library/std/src/thread/local/tests.rs

@@ -23,11 +23,11 @@ impl Signal {
     }
 }
 
-struct Foo(Signal);
+struct NotifyOnDrop(Signal);
 
-impl Drop for Foo {
+impl Drop for NotifyOnDrop {
     fn drop(&mut self) {
-        let Foo(ref f) = *self;
+        let NotifyOnDrop(ref f) = *self;
         f.notify();
     }
 }
@@ -82,18 +82,18 @@ fn states() {
 
 #[test]
 fn smoke_dtor() {
-    thread_local!(static FOO: UnsafeCell<Option<Foo>> = UnsafeCell::new(None));
+    thread_local!(static FOO: UnsafeCell<Option<NotifyOnDrop>> = UnsafeCell::new(None));
     run(&FOO);
-    thread_local!(static FOO2: UnsafeCell<Option<Foo>> = const { UnsafeCell::new(None) });
+    thread_local!(static FOO2: UnsafeCell<Option<NotifyOnDrop>> = const { UnsafeCell::new(None) });
     run(&FOO2);
 
-    fn run(key: &'static LocalKey<UnsafeCell<Option<Foo>>>) {
+    fn run(key: &'static LocalKey<UnsafeCell<Option<NotifyOnDrop>>>) {
         let signal = Signal::default();
         let signal2 = signal.clone();
         let t = thread::spawn(move || unsafe {
             let mut signal = Some(signal2);
             key.with(|f| {
-                *f.get() = Some(Foo(signal.take().unwrap()));
+                *f.get() = Some(NotifyOnDrop(signal.take().unwrap()));
             });
         });
         signal.wait();
@@ -187,13 +187,13 @@ fn self_referential() {
 fn dtors_in_dtors_in_dtors() {
     struct S1(Signal);
     thread_local!(static K1: UnsafeCell<Option<S1>> = UnsafeCell::new(None));
-    thread_local!(static K2: UnsafeCell<Option<Foo>> = UnsafeCell::new(None));
+    thread_local!(static K2: UnsafeCell<Option<NotifyOnDrop>> = UnsafeCell::new(None));
 
     impl Drop for S1 {
         fn drop(&mut self) {
             let S1(ref signal) = *self;
             unsafe {
-                let _ = K2.try_with(|s| *s.get() = Some(Foo(signal.clone())));
+                let _ = K2.try_with(|s| *s.get() = Some(NotifyOnDrop(signal.clone())));
             }
         }
     }
@@ -211,13 +211,13 @@ fn dtors_in_dtors_in_dtors() {
 fn dtors_in_dtors_in_dtors_const_init() {
     struct S1(Signal);
     thread_local!(static K1: UnsafeCell<Option<S1>> = const { UnsafeCell::new(None) });
-    thread_local!(static K2: UnsafeCell<Option<Foo>> = const { UnsafeCell::new(None) });
+    thread_local!(static K2: UnsafeCell<Option<NotifyOnDrop>> = const { UnsafeCell::new(None) });
 
     impl Drop for S1 {
         fn drop(&mut self) {
             let S1(ref signal) = *self;
             unsafe {
-                let _ = K2.try_with(|s| *s.get() = Some(Foo(signal.clone())));
+                let _ = K2.try_with(|s| *s.get() = Some(NotifyOnDrop(signal.clone())));
             }
         }
     }

src/librustdoc/clean/inline.rs

@@ -600,7 +600,9 @@ fn build_module_items(
                 items.push(clean::Item {
                     name: None,
                     attrs: Box::new(clean::Attributes::default()),
-                    item_id: ItemId::Primitive(prim_ty, did.krate),
+                    // We can use the item's `DefId` directly since the only information ever used
+                    // from it is `DefId.krate`.
+                    item_id: ItemId::DefId(did),
                     kind: Box::new(clean::ImportItem(clean::Import::new_simple(
                         item.ident.name,
                         clean::ImportSource {

src/librustdoc/clean/types.rs

@@ -62,8 +62,6 @@ pub(crate) enum ItemId {
     Auto { trait_: DefId, for_: DefId },
     /// Identifier that is used for blanket implementations.
     Blanket { impl_id: DefId, for_: DefId },
-    /// Identifier for primitive types.
-    Primitive(PrimitiveType, CrateNum),
 }
 
 impl ItemId {
@@ -73,7 +71,6 @@ impl ItemId {
             ItemId::Auto { for_: id, .. }
             | ItemId::Blanket { for_: id, .. }
             | ItemId::DefId(id) => id.is_local(),
-            ItemId::Primitive(_, krate) => krate == LOCAL_CRATE,
         }
     }
 
@@ -98,7 +95,6 @@ impl ItemId {
             ItemId::Auto { for_: id, .. }
             | ItemId::Blanket { for_: id, .. }
             | ItemId::DefId(id) => id.krate,
-            ItemId::Primitive(_, krate) => krate,
         }
     }
 }
@@ -707,15 +703,13 @@ impl Item {
         let def_id = match self.item_id {
             // Anything but DefId *shouldn't* matter, but return a reasonable value anyway.
             ItemId::Auto { .. } | ItemId::Blanket { .. } => return None,
-            // Primitives and Keywords are written in the source code as private modules.
-            // The modules need to be private so that nobody actually uses them, but the
-            // keywords and primitives that they are documenting are public.
-            ItemId::Primitive(..) => return Some(Visibility::Public),
             ItemId::DefId(def_id) => def_id,
         };
 
         match *self.kind {
-            // Explication on `ItemId::Primitive` just above.
+            // Primitives and Keywords are written in the source code as private modules.
+            // The modules need to be private so that nobody actually uses them, but the
+            // keywords and primitives that they are documenting are public.
             ItemKind::KeywordItem | ItemKind::PrimitiveItem(_) => return Some(Visibility::Public),
             // Variant fields inherit their enum's visibility.
             StructFieldItem(..) if is_field_vis_inherited(tcx, def_id) => {

src/librustdoc/formats/mod.rs

@@ -53,12 +53,6 @@ impl Impl {
             ItemId::Blanket { impl_id, .. } => impl_id,
             ItemId::Auto { trait_, .. } => trait_,
             ItemId::DefId(def_id) => def_id,
-            ItemId::Primitive(_, _) => {
-                panic!(
-                    "Unexpected ItemId::Primitive in expect_def_id: {:?}",
-                    self.impl_item.item_id
-                )
-            }
         }
     }