Auto merge of #142656 - jhpratt:rollup-46k4zk0, r=jhpratt

Rollup of 10 pull requests

Successful merges:

 - #135656 (Add `-Z hint-mostly-unused` to tell rustc that most of a crate will go unused)
 - #138237 (Get rid of `EscapeDebugInner`.)
 - #140772 ({aarch64,x86_64}-pc-windows-gnullvm: build host tools)
 - #140774 (Affirm `-Cforce-frame-pointers=off` does not override)
 - #141610 (Stabilize `feature(generic_arg_infer)`)
 - #141864 (Handle win32 separator for cygwin paths)
 - #142384 (Bringing `rustc_rayon_core` in tree as `rustc_thread_pool`)
 - #142502 (rustdoc_json: improve handling of generic args)
 - #142571 (Reason about borrowed classes in CopyProp.)
 - #142591 (Add spawn APIs for BootstrapCommand to support deferred command execution)

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

Author: bors

Cargo.lock

@@ -2983,6 +2983,15 @@ dependencies = [
  "getrandom 0.3.3",
 ]
 
+[[package]]
+name = "rand_xorshift"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "513962919efc330f829edb2535844d1b912b0fbe2ca165d613e4e8788bb05a5a"
+dependencies = [
+ "rand_core 0.9.3",
+]
+
 [[package]]
 name = "rand_xoshiro"
 version = "0.7.0"
@@ -3182,16 +3191,6 @@ dependencies = [
  "tikv-jemalloc-sys",
 ]
 
-[[package]]
-name = "rustc-rayon-core"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f42932dcd3bcbe484b38a3ccf79b7906fac41c02d408b5b1bac26da3416efdb"
-dependencies = [
- "crossbeam-deque",
- "crossbeam-utils",
-]
-
 [[package]]
 name = "rustc-semver"
 version = "1.1.0"
@@ -3560,14 +3559,14 @@ dependencies = [
  "parking_lot",
  "portable-atomic",
  "rustc-hash 2.1.1",
- "rustc-rayon-core",
  "rustc-stable-hash",
  "rustc_arena",
  "rustc_graphviz",
  "rustc_hashes",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",
+ "rustc_thread_pool",
  "smallvec",
  "stacker",
  "tempfile",
@@ -3915,7 +3914,6 @@ dependencies = [
 name = "rustc_interface"
 version = "0.0.0"
 dependencies = [
- "rustc-rayon-core",
  "rustc_abi",
  "rustc_ast",
  "rustc_ast_lowering",
@@ -3954,6 +3952,7 @@ dependencies = [
  "rustc_span",
  "rustc_symbol_mangling",
  "rustc_target",
+ "rustc_thread_pool",
  "rustc_trait_selection",
  "rustc_traits",
  "rustc_ty_utils",
@@ -4081,7 +4080,6 @@ dependencies = [
  "either",
  "gsgdt",
  "polonius-engine",
- "rustc-rayon-core",
  "rustc_abi",
  "rustc_apfloat",
  "rustc_arena",
@@ -4105,6 +4103,7 @@ dependencies = [
  "rustc_session",
  "rustc_span",
  "rustc_target",
+ "rustc_thread_pool",
  "rustc_type_ir",
  "smallvec",
  "thin-vec",
@@ -4351,7 +4350,6 @@ version = "0.0.0"
 dependencies = [
  "hashbrown",
  "parking_lot",
- "rustc-rayon-core",
  "rustc_abi",
  "rustc_ast",
  "rustc_attr_data_structures",
@@ -4366,6 +4364,7 @@ dependencies = [
  "rustc_serialize",
  "rustc_session",
  "rustc_span",
+ "rustc_thread_pool",
  "smallvec",
  "tracing",
 ]
@@ -4527,6 +4526,18 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "rustc_thread_pool"
+version = "0.0.0"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
+ "libc",
+ "rand 0.9.1",
+ "rand_xorshift",
+ "scoped-tls",
+]
+
 [[package]]
 name = "rustc_tools_util"
 version = "0.4.2"

Cargo.toml

@@ -60,7 +60,7 @@ exclude = [
   "obj",
 ]
 
-[profile.release.package.rustc-rayon-core]
+[profile.release.package.rustc_thread_pool]
 # The rustc fork of Rayon has deadlock detection code which intermittently
 # causes overflows in the CI (see https://github.com/rust-lang/rust/issues/90227)
 # so we turn overflow checks off for now.

compiler/rustc_ast_lowering/messages.ftl

@@ -172,9 +172,6 @@ ast_lowering_template_modifier = template modifier
 
 ast_lowering_this_not_async = this is not `async`
 
-ast_lowering_underscore_array_length_unstable =
-    using `_` for array lengths is unstable
-
 ast_lowering_underscore_expr_lhs_assign =
     in expressions, `_` can only be used on the left-hand side of an assignment
     .label = `_` not allowed here

compiler/rustc_ast_lowering/src/lib.rs

@@ -48,7 +48,7 @@ use rustc_data_structures::sorted_map::SortedMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::spawn;
 use rustc_data_structures::tagged_ptr::TaggedRef;
-use rustc_errors::{DiagArgFromDisplay, DiagCtxtHandle, StashKey};
+use rustc_errors::{DiagArgFromDisplay, DiagCtxtHandle};
 use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE, LocalDefId};
 use rustc_hir::lints::DelayedLint;
@@ -60,7 +60,7 @@ use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_macros::extension;
 use rustc_middle::span_bug;
 use rustc_middle::ty::{ResolverAstLowering, TyCtxt};
-use rustc_session::parse::{add_feature_diagnostics, feature_err};
+use rustc_session::parse::add_feature_diagnostics;
 use rustc_span::symbol::{Ident, Symbol, kw, sym};
 use rustc_span::{DUMMY_SP, DesugaringKind, Span};
 use smallvec::SmallVec;
@@ -2109,15 +2109,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         // `ExprKind::Paren(ExprKind::Underscore)` and should also be lowered to `GenericArg::Infer`
         match c.value.peel_parens().kind {
             ExprKind::Underscore => {
-                if !self.tcx.features().generic_arg_infer() {
-                    feature_err(
-                        &self.tcx.sess,
-                        sym::generic_arg_infer,
-                        c.value.span,
-                        fluent_generated::ast_lowering_underscore_array_length_unstable,
-                    )
-                    .stash(c.value.span, StashKey::UnderscoreForArrayLengths);
-                }
                 let ct_kind = hir::ConstArgKind::Infer(self.lower_span(c.value.span), ());
                 self.arena.alloc(hir::ConstArg { hir_id: self.lower_node_id(c.id), kind: ct_kind })
             }

compiler/rustc_data_structures/Cargo.toml

@@ -14,14 +14,14 @@ indexmap = "2.4.0"
 jobserver_crate = { version = "0.1.28", package = "jobserver" }
 measureme = "12.0.1"
 rustc-hash = "2.0.0"
-rustc-rayon-core = { version = "0.5.0" }
 rustc-stable-hash = { version = "0.1.0", features = ["nightly"] }
 rustc_arena = { path = "../rustc_arena" }
 rustc_graphviz = { path = "../rustc_graphviz" }
 rustc_hashes = { path = "../rustc_hashes" }
 rustc_index = { path = "../rustc_index", package = "rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
+rustc_thread_pool = { path = "../rustc_thread_pool" }
 smallvec = { version = "1.8.1", features = ["const_generics", "union", "may_dangle"] }
 stacker = "0.1.17"
 tempfile = "3.2"

compiler/rustc_data_structures/src/sync.rs

@@ -22,8 +22,6 @@
 //! |                         |                     | `parking_lot::Mutex<T>`         |
 //! | `RwLock<T>`             | `RefCell<T>`        | `parking_lot::RwLock<T>`        |
 //! | `MTLock<T>`        [^1] | `T`                 | `Lock<T>`                       |
-//! |                         |                     |                                 |
-//! | `ParallelIterator`      | `Iterator`          | `rayon::iter::ParallelIterator` |
 //!
 //! [^1]: `MTLock` is similar to `Lock`, but the serial version avoids the cost
 //! of a `RefCell`. This is appropriate when interior mutability is not

compiler/rustc_data_structures/src/sync/parallel.rs

@@ -96,7 +96,7 @@ macro_rules! parallel {
 pub fn spawn(func: impl FnOnce() + DynSend + 'static) {
     if mode::is_dyn_thread_safe() {
         let func = FromDyn::from(func);
-        rayon_core::spawn(|| {
+        rustc_thread_pool::spawn(|| {
             (func.into_inner())();
         });
     } else {
@@ -107,11 +107,11 @@ pub fn spawn(func: impl FnOnce() + DynSend + 'static) {
 // This function only works when `mode::is_dyn_thread_safe()`.
 pub fn scope<'scope, OP, R>(op: OP) -> R
 where
-    OP: FnOnce(&rayon_core::Scope<'scope>) -> R + DynSend,
+    OP: FnOnce(&rustc_thread_pool::Scope<'scope>) -> R + DynSend,
     R: DynSend,
 {
     let op = FromDyn::from(op);
-    rayon_core::scope(|s| FromDyn::from(op.into_inner()(s))).into_inner()
+    rustc_thread_pool::scope(|s| FromDyn::from(op.into_inner()(s))).into_inner()
 }
 
 #[inline]
@@ -124,7 +124,7 @@ where
         let oper_a = FromDyn::from(oper_a);
         let oper_b = FromDyn::from(oper_b);
         let (a, b) = parallel_guard(|guard| {
-            rayon_core::join(
+            rustc_thread_pool::join(
                 move || guard.run(move || FromDyn::from(oper_a.into_inner()())),
                 move || guard.run(move || FromDyn::from(oper_b.into_inner()())),
             )
@@ -158,7 +158,7 @@ fn par_slice<I: DynSend>(
             let (left, right) = items.split_at_mut(items.len() / 2);
             let mut left = state.for_each.derive(left);
             let mut right = state.for_each.derive(right);
-            rayon_core::join(move || par_rec(*left, state), move || par_rec(*right, state));
+            rustc_thread_pool::join(move || par_rec(*left, state), move || par_rec(*right, state));
         }
     }
 
@@ -241,7 +241,7 @@ pub fn par_map<I: DynSend, T: IntoIterator<Item = I>, R: DynSend, C: FromIterato
 pub fn broadcast<R: DynSend>(op: impl Fn(usize) -> R + DynSync) -> Vec<R> {
     if mode::is_dyn_thread_safe() {
         let op = FromDyn::from(op);
-        let results = rayon_core::broadcast(|context| op.derive(op(context.index())));
+        let results = rustc_thread_pool::broadcast(|context| op.derive(op(context.index())));
         results.into_iter().map(|r| r.into_inner()).collect()
     } else {
         vec![op(0)]

compiler/rustc_feature/src/accepted.rs

@@ -220,6 +220,8 @@ declare_features! (
     (accepted, fn_must_use, "1.27.0", Some(43302)),
     /// Allows capturing variables in scope using format_args!
     (accepted, format_args_capture, "1.58.0", Some(67984)),
+    /// Infer generic args for both consts and types.
+    (accepted, generic_arg_infer, "CURRENT_RUSTC_VERSION", Some(85077)),
     /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598).
     (accepted, generic_associated_types, "1.65.0", Some(44265)),
     /// Allows attributes on lifetime/type formal parameters in generics (RFC 1327).

compiler/rustc_feature/src/unstable.rs

@@ -520,8 +520,6 @@ declare_features! (
     (unstable, frontmatter, "1.88.0", Some(136889)),
     /// Allows defining gen blocks and `gen fn`.
     (unstable, gen_blocks, "1.75.0", Some(117078)),
-    /// Infer generic args for both consts and types.
-    (unstable, generic_arg_infer, "1.55.0", Some(85077)),
     /// Allows non-trivial generic constants which have to have wfness manually propagated to callers
     (incomplete, generic_const_exprs, "1.56.0", Some(76560)),
     /// Allows generic parameters and where-clauses on free & associated const items.

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -452,13 +452,6 @@ fn infer_placeholder_type<'tcx>(
             if let Some(ty) = node.ty() {
                 visitor.visit_ty_unambig(ty);
             }
-            // If we have just one span, let's try to steal a const `_` feature error.
-            let try_steal_span = if !tcx.features().generic_arg_infer() && visitor.spans.len() == 1
-            {
-                visitor.spans.first().copied()
-            } else {
-                None
-            };
             // If we didn't find any infer tys, then just fallback to `span`.
             if visitor.spans.is_empty() {
                 visitor.spans.push(span);
@@ -489,15 +482,7 @@ fn infer_placeholder_type<'tcx>(
                 }
             }
 
-            if let Some(try_steal_span) = try_steal_span {
-                cx.dcx().try_steal_replace_and_emit_err(
-                    try_steal_span,
-                    StashKey::UnderscoreForArrayLengths,
-                    diag,
-                )
-            } else {
-                diag.emit()
-            }
+            diag.emit()
         });
     Ty::new_error(tcx, guar)
 }

compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs

@@ -8,7 +8,7 @@ use rustc_middle::ty::{
     self, GenericArgsRef, GenericParamDef, GenericParamDefKind, IsSuggestable, Ty,
 };
 use rustc_session::lint::builtin::LATE_BOUND_LIFETIME_ARGUMENTS;
-use rustc_span::{kw, sym};
+use rustc_span::kw;
 use smallvec::SmallVec;
 use tracing::{debug, instrument};
 
@@ -258,19 +258,6 @@ pub fn lower_generic_args<'tcx: 'a, 'a>(
                             GenericParamDefKind::Const { .. },
                             _,
                         ) => {
-                            if let GenericParamDefKind::Const { .. } = param.kind
-                                && let GenericArg::Infer(inf) = arg
-                                && !tcx.features().generic_arg_infer()
-                            {
-                                rustc_session::parse::feature_err(
-                                    tcx.sess,
-                                    sym::generic_arg_infer,
-                                    inf.span,
-                                    "const arguments cannot yet be inferred with `_`",
-                                )
-                                .emit();
-                            }
-
                             // We lower to an infer even when the feature gate is not enabled
                             // as it is useful for diagnostics to be able to see a `ConstKind::Infer`
                             args.push(ctx.provided_kind(&args, param, arg));

compiler/rustc_interface/Cargo.toml

@@ -5,7 +5,6 @@ edition = "2024"
 
 [dependencies]
 # tidy-alphabetical-start
-rustc-rayon-core = { version = "0.5.0" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_lowering = { path = "../rustc_ast_lowering" }
 rustc_ast_passes = { path = "../rustc_ast_passes" }
@@ -43,6 +42,7 @@ rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_symbol_mangling = { path = "../rustc_symbol_mangling" }
 rustc_target = { path = "../rustc_target" }
+rustc_thread_pool = { path = "../rustc_thread_pool" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_traits = { path = "../rustc_traits" }
 rustc_ty_utils = { path = "../rustc_ty_utils" }

compiler/rustc_interface/src/tests.rs

@@ -802,6 +802,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(force_unstable_if_unmarked, true);
     tracked!(function_return, FunctionReturn::ThunkExtern);
     tracked!(function_sections, Some(false));
+    tracked!(hint_mostly_unused, true);
     tracked!(human_readable_cgu_names, true);
     tracked!(incremental_ignore_spans, true);
     tracked!(inline_mir, Some(true));

compiler/rustc_interface/src/util.rs

@@ -208,7 +208,7 @@ pub(crate) fn run_in_thread_pool_with_globals<
 
     let proxy_ = Arc::clone(&proxy);
     let proxy__ = Arc::clone(&proxy);
-    let builder = rayon_core::ThreadPoolBuilder::new()
+    let builder = rustc_thread_pool::ThreadPoolBuilder::new()
         .thread_name(|_| "rustc".to_string())
         .acquire_thread_handler(move || proxy_.acquire_thread())
         .release_thread_handler(move || proxy__.release_thread())
@@ -218,7 +218,7 @@ pub(crate) fn run_in_thread_pool_with_globals<
             // locals to it. The new thread runs the deadlock handler.
 
             let current_gcx2 = current_gcx2.clone();
-            let registry = rayon_core::Registry::current();
+            let registry = rustc_thread_pool::Registry::current();
             let session_globals = rustc_span::with_session_globals(|session_globals| {
                 session_globals as *const SessionGlobals as usize
             });
@@ -265,7 +265,7 @@ pub(crate) fn run_in_thread_pool_with_globals<
             builder
                 .build_scoped(
                     // Initialize each new worker thread when created.
-                    move |thread: rayon_core::ThreadBuilder| {
+                    move |thread: rustc_thread_pool::ThreadBuilder| {
                         // Register the thread for use with the `WorkerLocal` type.
                         registry.register();
 
@@ -274,7 +274,7 @@ pub(crate) fn run_in_thread_pool_with_globals<
                         })
                     },
                     // Run `f` on the first thread in the thread pool.
-                    move |pool: &rayon_core::ThreadPool| {
+                    move |pool: &rustc_thread_pool::ThreadPool| {
                         pool.install(|| f(current_gcx.into_inner(), proxy))
                     },
                 )

compiler/rustc_middle/Cargo.toml

@@ -9,7 +9,6 @@ bitflags = "2.4.1"
 either = "1.5.0"
 gsgdt = "0.1.2"
 polonius-engine = "0.13.0"
-rustc-rayon-core = { version = "0.5.0" }
 rustc_abi = { path = "../rustc_abi" }
 rustc_apfloat = "0.2.0"
 rustc_arena = { path = "../rustc_arena" }
@@ -33,6 +32,7 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
+rustc_thread_pool = { path = "../rustc_thread_pool" }
 rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"