Rollup of 7 pull requests

Cargo.lock

@@ -1529,9 +1529,9 @@ dependencies = [
 
 [[package]]
 name = "hermit-abi"
-version = "0.3.1"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fed44880c466736ef9a5c5b5facefb5ed0785676d0c02d612db14e54f0d84286"
+checksum = "443144c8cdadd93ebf52ddb4056d257f5b52c04d3c804e657d19eb73fc33668b"
 dependencies = [
  "compiler_builtins",
  "rustc-std-workspace-alloc",
@@ -1864,7 +1864,7 @@ version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eae7b9aee968036d54dce06cebaefd919e4472e753296daccd6d344e3e2df0c2"
 dependencies = [
- "hermit-abi 0.3.1",
+ "hermit-abi 0.3.2",
  "libc",
  "windows-sys 0.48.0",
 ]
@@ -1881,7 +1881,7 @@ version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24fddda5af7e54bf7da53067d6e802dbcc381d0a8eef629df528e3ebf68755cb"
 dependencies = [
- "hermit-abi 0.3.1",
+ "hermit-abi 0.3.2",
  "rustix 0.38.2",
  "windows-sys 0.48.0",
 ]
@@ -2396,7 +2396,7 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
 dependencies = [
- "hermit-abi 0.3.1",
+ "hermit-abi 0.3.2",
  "libc",
 ]
 
@@ -4819,7 +4819,7 @@ dependencies = [
  "dlmalloc",
  "fortanix-sgx-abi",
  "hashbrown 0.14.0",
- "hermit-abi 0.3.1",
+ "hermit-abi 0.3.2",
  "libc",
  "miniz_oxide",
  "object",

compiler/rustc_codegen_ssa/src/mir/constant.rs

@@ -67,6 +67,20 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     ) -> Result<Option<ty::ValTree<'tcx>>, ErrorHandled> {
         let uv = match constant.literal {
             mir::ConstantKind::Unevaluated(uv, _) => uv.shrink(),
+            mir::ConstantKind::Ty(c) => match c.kind() {
+                // A constant that came from a const generic but was then used as an argument to old-style
+                // simd_shuffle (passing as argument instead of as a generic param).
+                rustc_type_ir::ConstKind::Value(valtree) => return Ok(Some(valtree)),
+                other => span_bug!(constant.span, "{other:#?}"),
+            },
+            // We should never encounter `ConstantKind::Val` unless MIR opts (like const prop) evaluate
+            // a constant and write that value back into `Operand`s. This could happen, but is unlikely.
+            // Also: all users of `simd_shuffle` are on unstable and already need to take a lot of care
+            // around intrinsics. For an issue to happen here, it would require a macro expanding to a
+            // `simd_shuffle` call without wrapping the constant argument in a `const {}` block, but
+            // the user pass through arbitrary expressions.
+            // FIXME(oli-obk): replace the magic const generic argument of `simd_shuffle` with a real
+            // const generic.
             other => span_bug!(constant.span, "{other:#?}"),
         };
         let uv = self.monomorphize(uv);

compiler/rustc_lint/src/context.rs

@@ -956,6 +956,14 @@ pub trait LintContext: Sized {
                     db.span_note(glob_reexport_span, format!("the name `{}` in the {} namespace is supposed to be publicly re-exported here", name, namespace));
                     db.span_note(private_item_span, "but the private item here shadows it".to_owned());
                 }
+                BuiltinLintDiagnostics::UnusedQualifications { path_span, unqualified_path } => {
+                    db.span_suggestion_verbose(
+                        path_span,
+                        "replace it with the unqualified path",
+                        unqualified_path,
+                        Applicability::MachineApplicable
+                    );
+                }
             }
             // Rewrap `db`, and pass control to the user.
             decorate(db)

compiler/rustc_lint_defs/src/lib.rs

@@ -550,6 +550,12 @@ pub enum BuiltinLintDiagnostics {
         /// The local binding that shadows the glob reexport.
         private_item_span: Span,
     },
+    UnusedQualifications {
+        /// The span of the unnecessarily-qualified path.
+        path_span: Span,
+        /// The replacement unqualified path.
+        unqualified_path: Ident,
+    },
 }
 
 /// Lints that are buffered up early on in the `Session` before the

compiler/rustc_resolve/src/late.rs

@@ -3917,11 +3917,15 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             };
             if res == unqualified_result {
                 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
-                self.r.lint_buffer.buffer_lint(
+                self.r.lint_buffer.buffer_lint_with_diagnostic(
                     lint,
                     finalize.node_id,
                     finalize.path_span,
                     "unnecessary qualification",
+                    lint::BuiltinLintDiagnostics::UnusedQualifications {
+                        path_span: finalize.path_span,
+                        unqualified_path: path.last().unwrap().ident
+                    }
                 )
             }
         }

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -96,9 +96,11 @@ impl<'tcx> Tables<'tcx> {
             },
             ty::Adt(_, _) => todo!(),
             ty::Foreign(_) => todo!(),
-            ty::Str => todo!(),
-            ty::Array(_, _) => todo!(),
-            ty::Slice(_) => todo!(),
+            ty::Str => TyKind::RigidTy(RigidTy::Str),
+            ty::Array(ty, constant) => {
+                TyKind::RigidTy(RigidTy::Array(self.intern_ty(*ty), opaque(constant)))
+            }
+            ty::Slice(ty) => TyKind::RigidTy(RigidTy::Slice(self.intern_ty(*ty))),
             ty::RawPtr(_) => todo!(),
             ty::Ref(_, _, _) => todo!(),
             ty::FnDef(_, _) => todo!(),

compiler/rustc_smir/src/stable_mir/ty.rs

@@ -1,4 +1,7 @@
 use super::with;
+use crate::rustc_internal::Opaque;
+
+type Const = Opaque;
 
 #[derive(Copy, Clone, Debug)]
 pub struct Ty(pub usize);
@@ -21,6 +24,9 @@ pub enum RigidTy {
     Int(IntTy),
     Uint(UintTy),
     Float(FloatTy),
+    Str,
+    Array(Ty, Const),
+    Slice(Ty),
     Tuple(Vec<Ty>),
 }
 

compiler/rustc_trait_selection/src/solve/eval_ctxt/select.rs

@@ -4,21 +4,23 @@ use rustc_hir::def_id::DefId;
 use rustc_infer::infer::{DefineOpaqueTypes, InferCtxt, InferOk};
 use rustc_infer::traits::util::supertraits;
 use rustc_infer::traits::{
-    Obligation, PolyTraitObligation, PredicateObligation, Selection, SelectionResult,
+    Obligation, PolyTraitObligation, PredicateObligation, Selection, SelectionResult, TraitEngine,
 };
 use rustc_middle::traits::solve::{CanonicalInput, Certainty, Goal};
 use rustc_middle::traits::{
     ImplSource, ImplSourceObjectData, ImplSourceTraitUpcastingData, ImplSourceUserDefinedData,
     ObligationCause, SelectionError,
 };
-use rustc_middle::ty::{self, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::DUMMY_SP;
 
 use crate::solve::assembly::{BuiltinImplSource, Candidate, CandidateSource};
 use crate::solve::eval_ctxt::{EvalCtxt, GenerateProofTree};
 use crate::solve::inspect::ProofTreeBuilder;
 use crate::solve::search_graph::OverflowHandler;
 use crate::traits::vtable::{count_own_vtable_entries, prepare_vtable_segments, VtblSegment};
+use crate::traits::StructurallyNormalizeExt;
+use crate::traits::TraitEngineExt;
 
 pub trait InferCtxtSelectExt<'tcx> {
     fn select_in_new_trait_solver(
@@ -220,25 +222,33 @@ fn rematch_object<'tcx>(
     goal: Goal<'tcx, ty::TraitPredicate<'tcx>>,
     mut nested: Vec<PredicateObligation<'tcx>>,
 ) -> SelectionResult<'tcx, Selection<'tcx>> {
-    let self_ty = goal.predicate.self_ty();
-    let ty::Dynamic(data, _, source_kind) = *self_ty.kind()
+    let a_ty = structurally_normalize(goal.predicate.self_ty(), infcx, goal.param_env, &mut nested);
+    let ty::Dynamic(data, _, source_kind) = *a_ty.kind()
     else {
         bug!()
     };
-    let source_trait_ref = data.principal().unwrap().with_self_ty(infcx.tcx, self_ty);
-
-    let (is_upcasting, target_trait_ref_unnormalized) = if Some(goal.predicate.def_id())
-        == infcx.tcx.lang_items().unsize_trait()
-    {
-        assert_eq!(source_kind, ty::Dyn, "cannot upcast dyn*");
-        if let ty::Dynamic(data, _, ty::Dyn) = goal.predicate.trait_ref.substs.type_at(1).kind() {
-            (true, data.principal().unwrap().with_self_ty(infcx.tcx, self_ty))
+    let source_trait_ref = data.principal().unwrap().with_self_ty(infcx.tcx, a_ty);
+
+    let (is_upcasting, target_trait_ref_unnormalized) =
+        if Some(goal.predicate.def_id()) == infcx.tcx.lang_items().unsize_trait() {
+            assert_eq!(source_kind, ty::Dyn, "cannot upcast dyn*");
+            let b_ty = structurally_normalize(
+                goal.predicate.trait_ref.substs.type_at(1),
+                infcx,
+                goal.param_env,
+                &mut nested,
+            );
+            if let ty::Dynamic(data, _, ty::Dyn) = *b_ty.kind() {
+                // FIXME: We also need to ensure that the source lifetime outlives the
+                // target lifetime. This doesn't matter for codegen, though, and only
+                // *really* matters if the goal's certainty is ambiguous.
+                (true, data.principal().unwrap().with_self_ty(infcx.tcx, a_ty))
+            } else {
+                bug!()
+            }
         } else {
-            bug!()
-        }
-    } else {
-        (false, ty::Binder::dummy(goal.predicate.trait_ref))
-    };
+            (false, ty::Binder::dummy(goal.predicate.trait_ref))
+        };
 
     let mut target_trait_ref = None;
     for candidate_trait_ref in supertraits(infcx.tcx, source_trait_ref) {
@@ -305,3 +315,22 @@ fn rematch_object<'tcx>(
         ImplSource::Object(ImplSourceObjectData { vtable_base, nested })
     }))
 }
+
+fn structurally_normalize<'tcx>(
+    ty: Ty<'tcx>,
+    infcx: &InferCtxt<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+    nested: &mut Vec<PredicateObligation<'tcx>>,
+) -> Ty<'tcx> {
+    if matches!(ty.kind(), ty::Alias(..)) {
+        let mut engine = <dyn TraitEngine<'tcx>>::new(infcx);
+        let normalized_ty = infcx
+            .at(&ObligationCause::dummy(), param_env)
+            .structurally_normalize(ty, &mut *engine)
+            .expect("normalization shouldn't fail if we got to here");
+        nested.extend(engine.pending_obligations());
+        normalized_ty
+    } else {
+        ty
+    }
+}

library/std/Cargo.toml

@@ -45,7 +45,7 @@ dlmalloc = { version = "0.2.3", features = ['rustc-dep-of-std'] }
 fortanix-sgx-abi = { version = "0.5.0", features = ['rustc-dep-of-std'], public = true }
 
 [target.'cfg(target_os = "hermit")'.dependencies]
-hermit-abi = { version = "0.3.0", features = ['rustc-dep-of-std'] }
+hermit-abi = { version = "0.3.2", features = ['rustc-dep-of-std'], public = true }
 
 [target.wasm32-wasi.dependencies]
 wasi = { version = "0.11.0", features = ['rustc-dep-of-std'], default-features = false }

library/std/src/collections/hash/set.rs

@@ -65,8 +65,8 @@ use super::map::{map_try_reserve_error, RandomState};
 /// ```
 ///
 /// The easiest way to use `HashSet` with a custom type is to derive
-/// [`Eq`] and [`Hash`]. We must also derive [`PartialEq`], this will in the
-/// future be implied by [`Eq`].
+/// [`Eq`] and [`Hash`]. We must also derive [`PartialEq`],
+/// which is required if [`Eq`] is derived.
 ///
 /// ```
 /// use std::collections::HashSet;

library/std/src/sys/hermit/thread.rs

@@ -1,6 +1,5 @@
 #![allow(dead_code)]
 
-use super::unsupported;
 use crate::ffi::CStr;
 use crate::io;
 use crate::mem;
@@ -99,7 +98,7 @@ impl Thread {
 }
 
 pub fn available_parallelism() -> io::Result<NonZeroUsize> {
-    unsupported()
+    unsafe { Ok(NonZeroUsize::new_unchecked(abi::get_processor_count())) }
 }
 
 pub mod guard {

library/std/src/sys/hermit/time.rs

@@ -40,7 +40,7 @@ impl Timespec {
     }
 
     fn checked_add_duration(&self, other: &Duration) -> Option<Timespec> {
-        let mut secs = self.tv_sec.checked_add_unsigned(other.as_secs())?;
+        let mut secs = self.t.tv_sec.checked_add_unsigned(other.as_secs())?;
 
         // Nano calculations can't overflow because nanos are <1B which fit
         // in a u32.
@@ -53,7 +53,7 @@ impl Timespec {
     }
 
     fn checked_sub_duration(&self, other: &Duration) -> Option<Timespec> {
-        let mut secs = self.tv_sec.checked_sub_unsigned(other.as_secs())?;
+        let mut secs = self.t.tv_sec.checked_sub_unsigned(other.as_secs())?;
 
         // Similar to above, nanos can't overflow.
         let mut nsec = self.t.tv_nsec as i32 - other.subsec_nanos() as i32;