Rollup of 8 pull requests

compiler/rustc_resolve/src/imports.rs

@@ -48,6 +48,7 @@ pub(crate) enum ImportKind<'a> {
         /// `source` in `use prefix::source as target`.
         source: Ident,
         /// `target` in `use prefix::source as target`.
+        /// It will directly use `source` when the format is `use prefix::source`.
         target: Ident,
         /// Bindings to which `source` refers to.
         source_bindings: PerNS<Cell<Result<NameBinding<'a>, Determinacy>>>,

library/core/src/num/flt2dec/strategy/dragon.rs

@@ -12,48 +12,51 @@ use crate::num::flt2dec::{round_up, Decoded, MAX_SIG_DIGITS};
 
 static POW10: [Digit; 10] =
     [1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000];
-static TWOPOW10: [Digit; 10] =
-    [2, 20, 200, 2000, 20000, 200000, 2000000, 20000000, 200000000, 2000000000];
-
-// precalculated arrays of `Digit`s for 10^(2^n)
-static POW10TO16: [Digit; 2] = [0x6fc10000, 0x2386f2];
-static POW10TO32: [Digit; 4] = [0, 0x85acef81, 0x2d6d415b, 0x4ee];
-static POW10TO64: [Digit; 7] = [0, 0, 0xbf6a1f01, 0x6e38ed64, 0xdaa797ed, 0xe93ff9f4, 0x184f03];
-static POW10TO128: [Digit; 14] = [
-    0, 0, 0, 0, 0x2e953e01, 0x3df9909, 0xf1538fd, 0x2374e42f, 0xd3cff5ec, 0xc404dc08, 0xbccdb0da,
-    0xa6337f19, 0xe91f2603, 0x24e,
+// precalculated arrays of `Digit`s for 5^(2^n).
+static POW5TO16: [Digit; 2] = [0x86f26fc1, 0x23];
+static POW5TO32: [Digit; 3] = [0x85acef81, 0x2d6d415b, 0x4ee];
+static POW5TO64: [Digit; 5] = [0xbf6a1f01, 0x6e38ed64, 0xdaa797ed, 0xe93ff9f4, 0x184f03];
+static POW5TO128: [Digit; 10] = [
+    0x2e953e01, 0x3df9909, 0xf1538fd, 0x2374e42f, 0xd3cff5ec, 0xc404dc08, 0xbccdb0da, 0xa6337f19,
+    0xe91f2603, 0x24e,
 ];
-static POW10TO256: [Digit; 27] = [
-    0, 0, 0, 0, 0, 0, 0, 0, 0x982e7c01, 0xbed3875b, 0xd8d99f72, 0x12152f87, 0x6bde50c6, 0xcf4a6e70,
-    0xd595d80f, 0x26b2716e, 0xadc666b0, 0x1d153624, 0x3c42d35a, 0x63ff540e, 0xcc5573c0, 0x65f9ef17,
-    0x55bc28f2, 0x80dcc7f7, 0xf46eeddc, 0x5fdcefce, 0x553f7,
+static POW5TO256: [Digit; 19] = [
+    0x982e7c01, 0xbed3875b, 0xd8d99f72, 0x12152f87, 0x6bde50c6, 0xcf4a6e70, 0xd595d80f, 0x26b2716e,
+    0xadc666b0, 0x1d153624, 0x3c42d35a, 0x63ff540e, 0xcc5573c0, 0x65f9ef17, 0x55bc28f2, 0x80dcc7f7,
+    0xf46eeddc, 0x5fdcefce, 0x553f7,
 ];
 
 #[doc(hidden)]
 pub fn mul_pow10(x: &mut Big, n: usize) -> &mut Big {
     debug_assert!(n < 512);
+    // Save ourself the left shift for the smallest cases.
+    if n < 8 {
+        return x.mul_small(POW10[n & 7]);
+    }
+    // Multiply by the powers of 5 and shift the 2s in at the end.
+    // This keeps the intermediate products smaller and faster.
     if n & 7 != 0 {
-        x.mul_small(POW10[n & 7]);
+        x.mul_small(POW10[n & 7] >> (n & 7));
     }
     if n & 8 != 0 {
-        x.mul_small(POW10[8]);
+        x.mul_small(POW10[8] >> 8);
     }
     if n & 16 != 0 {
-        x.mul_digits(&POW10TO16);
+        x.mul_digits(&POW5TO16);
     }
     if n & 32 != 0 {
-        x.mul_digits(&POW10TO32);
+        x.mul_digits(&POW5TO32);
     }
     if n & 64 != 0 {
-        x.mul_digits(&POW10TO64);
+        x.mul_digits(&POW5TO64);
     }
     if n & 128 != 0 {
-        x.mul_digits(&POW10TO128);
+        x.mul_digits(&POW5TO128);
     }
     if n & 256 != 0 {
-        x.mul_digits(&POW10TO256);
+        x.mul_digits(&POW5TO256);
     }
-    x
+    x.mul_pow2(n)
 }
 
 fn div_2pow10(x: &mut Big, mut n: usize) -> &mut Big {
@@ -62,7 +65,7 @@ fn div_2pow10(x: &mut Big, mut n: usize) -> &mut Big {
         x.div_rem_small(POW10[largest]);
         n -= largest;
     }
-    x.div_rem_small(TWOPOW10[n]);
+    x.div_rem_small(POW10[n] << 1);
     x
 }
 

library/core/src/slice/mod.rs

@@ -522,7 +522,7 @@ impl<T> [T] {
     /// ```
     #[inline]
     #[stable(feature = "slice_first_last_chunk", since = "1.77.0")]
-    #[rustc_const_stable(feature = "slice_first_last_chunk", since = "1.77.0")]
+    #[rustc_const_stable(feature = "const_slice_last_chunk", since = "1.80.0")]
     pub const fn last_chunk<const N: usize>(&self) -> Option<&[T; N]> {
         if self.len() < N {
             None

library/std/src/sys/pal/unix/thread.rs

@@ -455,8 +455,18 @@ pub fn available_parallelism() -> io::Result<NonZero<usize>> {
 
                 Ok(NonZero::new_unchecked(sinfo.cpu_count as usize))
             }
+        } else if #[cfg(target_os = "vxworks")] {
+            // Note: there is also `vxCpuConfiguredGet`, closer to _SC_NPROCESSORS_CONF
+            // expectations than the actual cores availability.
+            extern "C" {
+                fn vxCpuEnabledGet() -> libc::cpuset_t;
+            }
+
+            // always fetches a valid bitmask
+            let set = unsafe { vxCpuEnabledGet() };
+            Ok(NonZero::new_unchecked(set.count_ones() as usize))
         } else {
-            // FIXME: implement on vxWorks, Redox, l4re
+            // FIXME: implement on Redox, l4re
             Err(io::const_io_error!(io::ErrorKind::Unsupported, "Getting the number of hardware threads is not supported on the target platform"))
         }
     }

src/librustdoc/clean/inline.rs

@@ -12,7 +12,7 @@ use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::hygiene::MacroKind;
-use rustc_span::symbol::{kw, sym, Symbol};
+use rustc_span::symbol::{sym, Symbol};
 use thin_vec::{thin_vec, ThinVec};
 use {rustc_ast as ast, rustc_hir as hir};
 
@@ -792,11 +792,7 @@ fn build_macro(
 fn filter_non_trait_generics(trait_did: DefId, mut g: clean::Generics) -> clean::Generics {
     for pred in &mut g.where_predicates {
         match *pred {
-            clean::WherePredicate::BoundPredicate {
-                ty: clean::Generic(ref s),
-                ref mut bounds,
-                ..
-            } if *s == kw::SelfUpper => {
+            clean::WherePredicate::BoundPredicate { ty: clean::SelfTy, ref mut bounds, .. } => {
                 bounds.retain(|bound| match bound {
                     clean::GenericBound::TraitBound(clean::PolyTrait { trait_, .. }, _) => {
                         trait_.def_id() != trait_did
@@ -812,13 +808,13 @@ fn filter_non_trait_generics(trait_did: DefId, mut g: clean::Generics) -> clean:
         clean::WherePredicate::BoundPredicate {
             ty:
                 clean::QPath(box clean::QPathData {
-                    self_type: clean::Generic(ref s),
+                    self_type: clean::Generic(_),
                     trait_: Some(trait_),
                     ..
                 }),
             bounds,
             ..
-        } => !(bounds.is_empty() || *s == kw::SelfUpper && trait_.def_id() == trait_did),
+        } => !bounds.is_empty() && trait_.def_id() != trait_did,
         _ => true,
     });
     g
@@ -832,9 +828,7 @@ fn separate_supertrait_bounds(
 ) -> (clean::Generics, Vec<clean::GenericBound>) {
     let mut ty_bounds = Vec::new();
     g.where_predicates.retain(|pred| match *pred {
-        clean::WherePredicate::BoundPredicate { ty: clean::Generic(ref s), ref bounds, .. }
-            if *s == kw::SelfUpper =>
-        {
+        clean::WherePredicate::BoundPredicate { ty: clean::SelfTy, ref bounds, .. } => {
             ty_bounds.extend(bounds.iter().cloned());
             false
         }

src/librustdoc/clean/mod.rs

@@ -1351,11 +1351,11 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                 let self_arg_ty =
                     tcx.fn_sig(assoc_item.def_id).instantiate_identity().input(0).skip_binder();
                 if self_arg_ty == self_ty {
-                    item.decl.inputs.values[0].type_ = Generic(kw::SelfUpper);
+                    item.decl.inputs.values[0].type_ = SelfTy;
                 } else if let ty::Ref(_, ty, _) = *self_arg_ty.kind() {
                     if ty == self_ty {
                         match item.decl.inputs.values[0].type_ {
-                            BorrowedRef { ref mut type_, .. } => **type_ = Generic(kw::SelfUpper),
+                            BorrowedRef { ref mut type_, .. } => **type_ = SelfTy,
                             _ => unreachable!(),
                         }
                     }
@@ -1439,9 +1439,8 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                         if trait_.def_id() != assoc_item.container_id(tcx) {
                             return true;
                         }
-                        match *self_type {
-                            Generic(ref s) if *s == kw::SelfUpper => {}
-                            _ => return true,
+                        if *self_type != SelfTy {
+                            return true;
                         }
                         match &assoc.args {
                             GenericArgs::AngleBracketed { args, constraints } => {
@@ -2228,6 +2227,8 @@ pub(crate) fn clean_middle_ty<'tcx>(
         ty::Param(ref p) => {
             if let Some(bounds) = cx.impl_trait_bounds.remove(&p.index.into()) {
                 ImplTrait(bounds)
+            } else if p.name == kw::SelfUpper {
+                SelfTy
             } else {
                 Generic(p.name)
             }

src/librustdoc/clean/simplify.rs

@@ -145,7 +145,6 @@ pub(crate) fn sized_bounds(cx: &mut DocContext<'_>, generics: &mut clean::Generi
     // should be handled when cleaning associated types.
     generics.where_predicates.retain(|pred| {
         if let WP::BoundPredicate { ty: clean::Generic(param), bounds, .. } = pred
-            && *param != rustc_span::symbol::kw::SelfUpper
             && bounds.iter().any(|b| b.is_sized_bound(cx))
         {
             sized_params.insert(*param);

src/librustdoc/clean/types.rs

@@ -34,10 +34,9 @@ use thin_vec::ThinVec;
 use {rustc_ast as ast, rustc_hir as hir};
 
 pub(crate) use self::ItemKind::*;
-pub(crate) use self::SelfTy::*;
 pub(crate) use self::Type::{
     Array, BareFunction, BorrowedRef, DynTrait, Generic, ImplTrait, Infer, Primitive, QPath,
-    RawPointer, Slice, Tuple,
+    RawPointer, SelfTy, Slice, Tuple,
 };
 use crate::clean::cfg::Cfg;
 use crate::clean::clean_middle_path;
@@ -1384,8 +1383,8 @@ pub(crate) struct FnDecl {
 }
 
 impl FnDecl {
-    pub(crate) fn self_type(&self) -> Option<SelfTy> {
-        self.inputs.values.get(0).and_then(|v| v.to_self())
+    pub(crate) fn receiver_type(&self) -> Option<&Type> {
+        self.inputs.values.get(0).and_then(|v| v.to_receiver())
     }
 }
 
@@ -1403,27 +1402,9 @@ pub(crate) struct Argument {
     pub(crate) is_const: bool,
 }
 
-#[derive(Clone, PartialEq, Debug)]
-pub(crate) enum SelfTy {
-    SelfValue,
-    SelfBorrowed(Option<Lifetime>, Mutability),
-    SelfExplicit(Type),
-}
-
 impl Argument {
-    pub(crate) fn to_self(&self) -> Option<SelfTy> {
-        if self.name != kw::SelfLower {
-            return None;
-        }
-        if self.type_.is_self_type() {
-            return Some(SelfValue);
-        }
-        match self.type_ {
-            BorrowedRef { ref lifetime, mutability, ref type_ } if type_.is_self_type() => {
-                Some(SelfBorrowed(lifetime.clone(), mutability))
-            }
-            _ => Some(SelfExplicit(self.type_.clone())),
-        }
+    pub(crate) fn to_receiver(&self) -> Option<&Type> {
+        if self.name == kw::SelfLower { Some(&self.type_) } else { None }
     }
 }
 
@@ -1477,6 +1458,8 @@ pub(crate) enum Type {
     DynTrait(Vec<PolyTrait>, Option<Lifetime>),
     /// A type parameter.
     Generic(Symbol),
+    /// The `Self` type.
+    SelfTy,
     /// A primitive (aka, builtin) type.
     Primitive(PrimitiveType),
     /// A function pointer: `extern "ABI" fn(...) -> ...`
@@ -1571,6 +1554,8 @@ impl Type {
             // If both sides are generic, this returns true.
             (_, Type::Generic(_)) => true,
             (Type::Generic(_), _) => false,
+            // `Self` only matches itself.
+            (Type::SelfTy, Type::SelfTy) => true,
             // Paths account for both the path itself and its generics.
             (Type::Path { path: a }, Type::Path { path: b }) => {
                 a.def_id() == b.def_id()
@@ -1642,7 +1627,7 @@ impl Type {
 
     pub(crate) fn is_self_type(&self) -> bool {
         match *self {
-            Generic(name) => name == kw::SelfUpper,
+            SelfTy => true,
             _ => false,
         }
     }
@@ -1700,7 +1685,7 @@ impl Type {
             Type::Pat(..) => PrimitiveType::Pat,
             RawPointer(..) => PrimitiveType::RawPointer,
             QPath(box QPathData { ref self_type, .. }) => return self_type.def_id(cache),
-            Generic(_) | Infer | ImplTrait(_) => return None,
+            Generic(_) | SelfTy | Infer | ImplTrait(_) => return None,
         };
         Primitive(t).def_id(cache)
     }

src/librustdoc/clean/utils.rs

@@ -468,7 +468,7 @@ pub(crate) fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
     match path.res {
         Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
         Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } if path.segments.len() == 1 => {
-            Generic(kw::SelfUpper)
+            Type::SelfTy
         }
         Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => Generic(path.segments[0].name),
         _ => {

src/librustdoc/html/format.rs

@@ -1006,6 +1006,7 @@ fn fmt_type<'cx>(
 
     match *t {
         clean::Generic(name) => f.write_str(name.as_str()),
+        clean::SelfTy => f.write_str("Self"),
         clean::Type::Path { ref path } => {
             // Paths like `T::Output` and `Self::Output` should be rendered with all segments.
             let did = path.def_id();
@@ -1452,29 +1453,22 @@ impl clean::FnDecl {
 
         let last_input_index = self.inputs.values.len().checked_sub(1);
         for (i, input) in self.inputs.values.iter().enumerate() {
-            if let Some(selfty) = input.to_self() {
+            if let Some(selfty) = input.to_receiver() {
                 match selfty {
-                    clean::SelfValue => {
+                    clean::SelfTy => {
                         write!(f, "self")?;
                     }
-                    clean::SelfBorrowed(Some(ref lt), mutability) => {
-                        write!(
-                            f,
-                            "{amp}{lifetime} {mutability}self",
-                            lifetime = lt.print(),
-                            mutability = mutability.print_with_space(),
-                        )?;
-                    }
-                    clean::SelfBorrowed(None, mutability) => {
-                        write!(
-                            f,
-                            "{amp}{mutability}self",
-                            mutability = mutability.print_with_space(),
-                        )?;
+                    clean::BorrowedRef { lifetime, mutability, type_: box clean::SelfTy } => {
+                        write!(f, "{amp}")?;
+                        match lifetime {
+                            Some(lt) => write!(f, "{lt} ", lt = lt.print())?,
+                            None => {}
+                        }
+                        write!(f, "{mutability}self", mutability = mutability.print_with_space())?;
                     }
-                    clean::SelfExplicit(ref typ) => {
+                    _ => {
                         write!(f, "self: ")?;
-                        typ.print(cx).fmt(f)?;
+                        selfty.print(cx).fmt(f)?;
                     }
                 }
             } else {

src/librustdoc/html/render/mod.rs

@@ -58,7 +58,7 @@ use serde::{Serialize, Serializer};
 
 pub(crate) use self::context::*;
 pub(crate) use self::span_map::{collect_spans_and_sources, LinkFromSrc};
-use crate::clean::{self, ItemId, RenderedLink, SelfTy};
+use crate::clean::{self, ItemId, RenderedLink};
 use crate::error::Error;
 use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
@@ -1372,21 +1372,20 @@ fn render_deref_methods(
 
 fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool {
     let self_type_opt = match *item.kind {
-        clean::MethodItem(ref method, _) => method.decl.self_type(),
-        clean::TyMethodItem(ref method) => method.decl.self_type(),
+        clean::MethodItem(ref method, _) => method.decl.receiver_type(),
+        clean::TyMethodItem(ref method) => method.decl.receiver_type(),
         _ => None,
     };
 
     if let Some(self_ty) = self_type_opt {
-        let (by_mut_ref, by_box, by_value) = match self_ty {
-            SelfTy::SelfBorrowed(_, mutability)
-            | SelfTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => {
+        let (by_mut_ref, by_box, by_value) = match *self_ty {
+            clean::Type::BorrowedRef { mutability, .. } => {
                 (mutability == Mutability::Mut, false, false)
             }
-            SelfTy::SelfExplicit(clean::Type::Path { path }) => {
+            clean::Type::Path { ref path } => {
                 (false, Some(path.def_id()) == tcx.lang_items().owned_box(), false)
             }
-            SelfTy::SelfValue => (false, false, true),
+            clean::Type::SelfTy => (false, false, true),
             _ => (false, false, false),
         };