Auto merge of rust-lang#98375 - JohnTitor:rollup-e5c6rgo, r=JohnTitor

Rollup of 10 pull requests

Successful merges:

 - rust-lang#95446 (update CPU usage script)
 - rust-lang#96768 (Use futex based thread parker on Fuchsia.)
 - rust-lang#97454 (Add release notes for 1.62)
 - rust-lang#97516 (clarify how Rust atomics correspond to C++ atomics)
 - rust-lang#97818 (Point at return expression for RPIT-related error)
 - rust-lang#97895 (Simplify `likely!` and `unlikely!` macro)
 - rust-lang#98005 (Add some tests for impossible bounds)
 - rust-lang#98226 (Document unstable `--extern` options)
 - rust-lang#98356 (Add missing period)
 - rust-lang#98363 (remove use of &Alloc in btree tests)

Failed merges:

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

README.md

@@ -83,7 +83,7 @@ by running it with the `--help` flag or reading the [rustc dev guide][rustcguide
     If you plan to use `x.py install` to create an installation, it is recommended
     that you set the `prefix` value in the `[install]` section to a directory.
 
-    Create install directory if you are not installing in default directory
+    Create install directory if you are not installing in default directory.
 
 4. Build and install:
 

RELEASES.md

@@ -1,3 +1,128 @@
+Version 1.62.0 (2022-06-30)
+==========================
+
+Language
+--------
+
+- [Stabilize `#[derive(Default)]` on enums with a `#[default]` variant][94457]
+- [Stop validating some checks in dead code after functions with uninhabited return types][93313]
+- [Fix constants not getting dropped if part of a diverging expression][94775]
+- [Support unit struct/enum variant in destructuring assignment][95380]
+- [Remove mutable_borrow_reservation_conflict lint and allow the code pattern][96268]
+
+Compiler
+--------
+
+- [linker: Stop using whole-archive on dependencies of dylibs][96436]
+- [Make `unaligned_references` lint deny-by-default][95372]
+  This lint is also a future compatibility lint, and is expected to eventually
+  become a hard error.
+- [Only add codegen backend to dep info if -Zbinary-dep-depinfo is used][93969]
+- [Reject `#[thread_local]` attribute on non-static items][95006]
+- [Add tier 3 `aarch64-pc-windows-gnullvm` and `x86_64-pc-windows-gnullvm` targets\*][94872]
+- [Implement a lint to warn about unused macro rules][96150]
+- [Promote `x86_64-unknown-none` target to Tier 2\*][95705]
+
+\* Refer to Rust's [platform support page][platform-support-doc] for more
+   information on Rust's tiered platform support.
+
+Libraries
+---------
+
+- [Move `CStr` to libcore, and `CString` to liballoc][94079]
+- [Windows: Use a pipe relay for chaining pipes][95841]
+- [Replace Linux Mutex and Condvar with futex based ones.][95035]
+- [Replace RwLock by a futex based one on Linux][95801]
+- [std: directly use pthread in UNIX parker implementation][96393]
+
+Stabilized APIs
+---------------
+
+- [`bool::then_some`]
+- [`f32::total_cmp`]
+- [`f64::total_cmp`]
+- [`Stdin::lines`]
+- [`windows::CommandExt::raw_arg`]
+- [`impl<T: Default> Default for AssertUnwindSafe<T>`]
+- [`From<Rc<str>> for Rc<[u8]>`][rc-u8-from-str]
+- [`From<Arc<str>> for Arc<[u8]>`][arc-u8-from-str]
+- [`FusedIterator for EncodeWide`]
+- [RDM intrinsics on aarch64][stdarch/1285]
+
+Clippy
+------
+
+- [Create clippy lint against unexpectedly late drop for temporaries in match scrutinee expressions][94206]
+
+Cargo
+-----
+
+- Added the `cargo add` command for adding dependencies to `Cargo.toml` from
+  the command-line.
+  [docs](https://doc.rust-lang.org/nightly/cargo/commands/cargo-add.html)
+- Package ID specs now support `name@version` syntax in addition to the
+  previous `name:version` to align with the behavior in `cargo add` and other
+  tools. `cargo install` and `cargo yank` also now support this syntax so the
+  version does not need to passed as a separate flag.
+- The `git` and `registry` directories in Cargo's home directory (usually
+  `~/.cargo`) are now marked as cache directories so that they are not
+  included in backups or content indexing (on Windows).
+- Added automatic `@` argfile support, which will use "response files" if the
+  command-line to `rustc` exceeds the operating system's limit.
+
+Compatibility Notes
+-------------------
+
+- `cargo test` now passes `--target` to `rustdoc` if the specified target is
+  the same as the host target.
+  [#10594](https://github.com/rust-lang/cargo/pull/10594)
+- [rustdoc: Remove .woff font files][96279]
+- [Enforce Copy bounds for repeat elements while considering lifetimes][95819]
+
+Internal Changes
+----------------
+
+- [Unify ReentrantMutex implementations across all platforms][96042]
+
+These changes provide no direct user facing benefits, but represent significant
+improvements to the internals and overall performance of rustc
+and related tools.
+
+[93313]: https://github.com/rust-lang/rust/pull/93313/
+[93969]: https://github.com/rust-lang/rust/pull/93969/
+[94079]: https://github.com/rust-lang/rust/pull/94079/
+[94206]: https://github.com/rust-lang/rust/pull/94206/
+[94457]: https://github.com/rust-lang/rust/pull/94457/
+[94775]: https://github.com/rust-lang/rust/pull/94775/
+[94872]: https://github.com/rust-lang/rust/pull/94872/
+[95006]: https://github.com/rust-lang/rust/pull/95006/
+[95035]: https://github.com/rust-lang/rust/pull/95035/
+[95372]: https://github.com/rust-lang/rust/pull/95372/
+[95380]: https://github.com/rust-lang/rust/pull/95380/
+[95431]: https://github.com/rust-lang/rust/pull/95431/
+[95705]: https://github.com/rust-lang/rust/pull/95705/
+[95801]: https://github.com/rust-lang/rust/pull/95801/
+[95819]: https://github.com/rust-lang/rust/pull/95819/
+[95841]: https://github.com/rust-lang/rust/pull/95841/
+[96042]: https://github.com/rust-lang/rust/pull/96042/
+[96150]: https://github.com/rust-lang/rust/pull/96150/
+[96268]: https://github.com/rust-lang/rust/pull/96268/
+[96279]: https://github.com/rust-lang/rust/pull/96279/
+[96393]: https://github.com/rust-lang/rust/pull/96393/
+[96436]: https://github.com/rust-lang/rust/pull/96436/
+[96557]: https://github.com/rust-lang/rust/pull/96557/
+
+[`bool::then_some`]: https://doc.rust-lang.org/stable/std/primitive.bool.html#method.then_some
+[`f32::total_cmp`]: https://doc.rust-lang.org/stable/std/primitive.f32.html#method.total_cmp
+[`f64::total_cmp`]: https://doc.rust-lang.org/stable/std/primitive.f64.html#method.total_cmp
+[`Stdin::lines`]: https://doc.rust-lang.org/stable/std/io/struct.Stdin.html#method.lines
+[`impl<T: Default> Default for AssertUnwindSafe<T>`]: https://doc.rust-lang.org/stable/std/panic/struct.AssertUnwindSafe.html#impl-Default
+[rc-u8-from-str]: https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#impl-From%3CRc%3Cstr%3E%3E
+[arc-u8-from-str]: https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#impl-From%3CArc%3Cstr%3E%3E
+[stdarch/1285]: https://github.com/rust-lang/stdarch/pull/1285
+[`windows::CommandExt::raw_arg`]: https://doc.rust-lang.org/stable/std/os/windows/process/trait.CommandExt.html#tymethod.raw_arg
+[`FusedIterator for EncodeWide`]: https://doc.rust-lang.org/stable/std/os/windows/ffi/struct.EncodeWide.html#impl-FusedIterator
+
 Version 1.61.0 (2022-05-19)
 ==========================
 

compiler/rustc_data_structures/src/lib.rs

@@ -11,7 +11,6 @@
 #![feature(associated_type_bounds)]
 #![feature(auto_traits)]
 #![feature(control_flow_enum)]
-#![feature(core_intrinsics)]
 #![feature(extend_one)]
 #![feature(let_else)]
 #![feature(hash_raw_entry)]
@@ -44,26 +43,6 @@ pub fn cold_path<F: FnOnce() -> R, R>(f: F) -> R {
     f()
 }
 
-#[macro_export]
-macro_rules! likely {
-    ($e:expr) => {
-        match $e {
-            #[allow(unused_unsafe)]
-            e => unsafe { std::intrinsics::likely(e) },
-        }
-    };
-}
-
-#[macro_export]
-macro_rules! unlikely {
-    ($e:expr) => {
-        match $e {
-            #[allow(unused_unsafe)]
-            e => unsafe { std::intrinsics::unlikely(e) },
-        }
-    };
-}
-
 pub mod base_n;
 pub mod binary_search_util;
 pub mod captures;

compiler/rustc_data_structures/src/profiling.rs

@@ -195,6 +195,7 @@ impl SelfProfilerRef {
         F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>,
     {
         #[inline(never)]
+        #[cold]
         fn cold_call<F>(profiler_ref: &SelfProfilerRef, f: F) -> TimingGuard<'_>
         where
             F: for<'a> FnOnce(&'a SelfProfiler) -> TimingGuard<'a>,
@@ -203,7 +204,7 @@ impl SelfProfilerRef {
             f(&**profiler)
         }
 
-        if unlikely!(self.event_filter_mask.contains(event_filter)) {
+        if self.event_filter_mask.contains(event_filter) {
             cold_call(self, f)
         } else {
             TimingGuard::none()

compiler/rustc_infer/src/infer/opaque_types.rs

@@ -5,7 +5,7 @@ use hir::{HirId, OpaqueTyOrigin};
 use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::vec_map::VecMap;
 use rustc_hir as hir;
-use rustc_middle::traits::ObligationCause;
+use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
 use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::subst::{GenericArgKind, Subst};
 use rustc_middle::ty::{
@@ -46,6 +46,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         value: T,
         body_id: HirId,
         span: Span,
+        code: ObligationCauseCode<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
     ) -> InferOk<'tcx, T> {
         if !value.has_opaque_types() {
@@ -68,10 +69,13 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     ) =>
                 {
                     let span = if span.is_dummy() { self.tcx.def_span(def_id) } else { span };
-                    let cause = ObligationCause::misc(span, body_id);
+                    let cause = ObligationCause::new(span, body_id, code.clone());
+                    // FIXME(compiler-errors): We probably should add a new TypeVariableOriginKind
+                    // for opaque types, and then use that kind to fix the spans for type errors
+                    // that we see later on.
                     let ty_var = self.next_ty_var(TypeVariableOrigin {
                         kind: TypeVariableOriginKind::TypeInference,
-                        span: cause.span,
+                        span,
                     });
                     obligations.extend(
                         self.handle_opaque_type(ty, ty_var, true, &cause, param_env)

compiler/rustc_middle/src/traits/mod.rs

@@ -387,6 +387,9 @@ pub enum ObligationCauseCode<'tcx> {
     /// Return type of this function
     ReturnType,
 
+    /// Opaque return type of this function
+    OpaqueReturnType(Option<(Ty<'tcx>, Span)>),
+
     /// Block implicit return
     BlockTailExpression(hir::HirId),
 

compiler/rustc_middle/src/ty/mod.rs

@@ -804,7 +804,7 @@ pub type PolyTraitPredicate<'tcx> = ty::Binder<'tcx, TraitPredicate<'tcx>>;
 
 impl<'tcx> TraitPredicate<'tcx> {
     pub fn remap_constness(&mut self, tcx: TyCtxt<'tcx>, param_env: &mut ParamEnv<'tcx>) {
-        if unlikely!(Some(self.trait_ref.def_id) == tcx.lang_items().drop_trait()) {
+        if std::intrinsics::unlikely(Some(self.trait_ref.def_id) == tcx.lang_items().drop_trait()) {
             // remap without changing constness of this predicate.
             // this is because `T: ~const Drop` has a different meaning to `T: Drop`
             // FIXME(fee1-dead): remove this logic after beta bump

compiler/rustc_query_system/src/dep_graph/graph.rs

@@ -750,7 +750,7 @@ impl<K: DepKind> DepGraph<K> {
             dep_node
         );
 
-        if unlikely!(!side_effects.is_empty()) {
+        if !side_effects.is_empty() {
             self.emit_side_effects(tcx, data, dep_node_index, side_effects);
         }
 

compiler/rustc_query_system/src/query/plumbing.rs

@@ -316,7 +316,7 @@ where
     OnHit: FnOnce(&C::Stored) -> R,
 {
     cache.lookup(&key, |value, index| {
-        if unlikely!(tcx.profiler().enabled()) {
+        if std::intrinsics::unlikely(tcx.profiler().enabled()) {
             tcx.profiler().query_cache_hit(index.into());
         }
         tcx.dep_graph().read_index(index);
@@ -354,7 +354,7 @@ where
                 .lookup(&key, |value, index| (value.clone(), index))
                 .unwrap_or_else(|_| panic!("value must be in cache after waiting"));
 
-            if unlikely!(tcx.dep_context().profiler().enabled()) {
+            if std::intrinsics::unlikely(tcx.dep_context().profiler().enabled()) {
                 tcx.dep_context().profiler().query_cache_hit(index.into());
             }
             query_blocked_prof_timer.finish_with_query_invocation_id(index.into());
@@ -422,7 +422,7 @@ where
     let diagnostics = diagnostics.into_inner();
     let side_effects = QuerySideEffects { diagnostics };
 
-    if unlikely!(!side_effects.is_empty()) {
+    if std::intrinsics::unlikely(!side_effects.is_empty()) {
         if query.anon {
             tcx.store_side_effects_for_anon_node(dep_node_index, side_effects);
         } else {
@@ -466,7 +466,9 @@ where
         prof_timer.finish_with_query_invocation_id(dep_node_index.into());
 
         if let Some(result) = result {
-            if unlikely!(tcx.dep_context().sess().opts.debugging_opts.query_dep_graph) {
+            if std::intrinsics::unlikely(
+                tcx.dep_context().sess().opts.debugging_opts.query_dep_graph,
+            ) {
                 dep_graph.mark_debug_loaded_from_disk(*dep_node)
             }
 
@@ -483,8 +485,8 @@ where
             // currently afford to verify every hash. This subset should still
             // give us some coverage of potential bugs though.
             let try_verify = prev_fingerprint.as_value().1 % 32 == 0;
-            if unlikely!(
-                try_verify || tcx.dep_context().sess().opts.debugging_opts.incremental_verify_ich
+            if std::intrinsics::unlikely(
+                try_verify || tcx.dep_context().sess().opts.debugging_opts.incremental_verify_ich,
             ) {
                 incremental_verify_ich(*tcx.dep_context(), &result, dep_node, query);
             }
@@ -723,7 +725,7 @@ where
     // Ensure that only one of them runs the query.
     let cache = Q::query_cache(tcx);
     let cached = cache.lookup(&key, |_, index| {
-        if unlikely!(tcx.dep_context().profiler().enabled()) {
+        if std::intrinsics::unlikely(tcx.dep_context().profiler().enabled()) {
             tcx.dep_context().profiler().query_cache_hit(index.into());
         }
     });

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

@@ -2661,6 +2661,15 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                     err.help("add `#![feature(trivial_bounds)]` to the crate attributes to enable");
                 }
             }
+            ObligationCauseCode::OpaqueReturnType(expr_info) => {
+                if let Some((expr_ty, expr_span)) = expr_info {
+                    let expr_ty = self.resolve_vars_if_possible(expr_ty);
+                    err.span_label(
+                        expr_span,
+                        format!("return type was inferred to be `{expr_ty}` here"),
+                    );
+                }
+            }
         }
     }
 

compiler/rustc_trait_selection/src/traits/project.rs

@@ -28,6 +28,7 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_infer::infer::resolve::OpportunisticRegionResolver;
+use rustc_infer::traits::ObligationCauseCode;
 use rustc_middle::traits::select::OverflowError;
 use rustc_middle::ty::fold::{MaxUniverse, TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_middle::ty::subst::Subst;
@@ -261,6 +262,7 @@ fn project_and_unify_type<'cx, 'tcx>(
             actual,
             obligation.cause.body_id,
             obligation.cause.span,
+            ObligationCauseCode::MiscObligation,
             obligation.param_env,
         );
     obligations.extend(new);

compiler/rustc_typeck/src/check/check.rs

@@ -101,8 +101,13 @@ pub(super) fn check_fn<'a, 'tcx>(
             declared_ret_ty,
             body.value.hir_id,
             DUMMY_SP,
+            traits::ObligationCauseCode::OpaqueReturnType(None),
             param_env,
         ));
+    // If we replaced declared_ret_ty with infer vars, then we must be infering
+    // an opaque type, so set a flag so we can improve diagnostics.
+    fcx.return_type_has_opaque = ret_ty != declared_ret_ty;
+
     fcx.ret_coercion = Some(RefCell::new(CoerceMany::new(ret_ty)));
     fcx.ret_type_span = Some(decl.output.span());
 

compiler/rustc_typeck/src/check/closure.rs

@@ -10,6 +10,7 @@ use rustc_hir::lang_items::LangItem;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::LateBoundRegionConversionTime;
 use rustc_infer::infer::{InferOk, InferResult};
+use rustc_infer::traits::ObligationCauseCode;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::{self, Ty};
@@ -645,8 +646,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     fn hide_parent_opaque_types(&self, ty: Ty<'tcx>, span: Span, body_id: hir::HirId) -> Ty<'tcx> {
-        let InferOk { value, obligations } =
-            self.replace_opaque_types_with_inference_vars(ty, body_id, span, self.param_env);
+        let InferOk { value, obligations } = self.replace_opaque_types_with_inference_vars(
+            ty,
+            body_id,
+            span,
+            ObligationCauseCode::MiscObligation,
+            self.param_env,
+        );
         self.register_predicates(obligations);
         value
     }