Rollup of 6 pull requests

compiler/rustc_middle/src/query/mod.rs

@@ -183,6 +183,15 @@ rustc_queries! {
  separate_provide_extern
  }
 
+ query unsizing_params_for_adt(key: DefId) -> rustc_index::bit_set::BitSet<u32>
+ {
+ arena_cache
+ desc { |tcx|
+ "determining what parameters of `{}` can participate in unsizing",
+ tcx.def_path_str(key),
+ }
+ }
+
  query analysis(key: ()) -> Result<(), ErrorGuaranteed> {
  eval_always
  desc { "running analysis passes on this crate" }

compiler/rustc_trait_selection/src/solve/mod.rs

@@ -141,17 +141,6 @@ type CanonicalResponse<'tcx> = Canonical<'tcx, Response<'tcx>>;
 /// solver, merge the two responses again.
 pub type QueryResult<'tcx> = Result<CanonicalResponse<'tcx>, NoSolution>;
 
-pub trait TyCtxtExt<'tcx> {
- fn evaluate_goal(self, goal: CanonicalGoal<'tcx>) -> QueryResult<'tcx>;
-}
-
-impl<'tcx> TyCtxtExt<'tcx> for TyCtxt<'tcx> {
- fn evaluate_goal(self, goal: CanonicalGoal<'tcx>) -> QueryResult<'tcx> {
- let mut search_graph = search_graph::SearchGraph::new(self);
- EvalCtxt::evaluate_canonical_goal(self, &mut search_graph, goal)
- }
-}
-
 pub trait InferCtxtEvalExt<'tcx> {
  /// Evaluates a goal from **outside** of the trait solver.
  ///
@@ -194,6 +183,15 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
  self.infcx.tcx
  }
 
+ /// The entry point of the solver.
+ ///
+ /// This function deals with (coinductive) cycles, overflow, and caching
+ /// and then calls [`EvalCtxt::compute_goal`] which contains the actual
+ /// logic of the solver.
+ ///
+ /// Instead of calling this function directly, use either [EvalCtxt::evaluate_goal]
+ /// if you're inside of the solver or [InferCtxtEvalExt::evaluate_root_goal] if you're
+ /// outside of it.
  #[instrument(level = "debug", skip(tcx, search_graph), ret)]
  fn evaluate_canonical_goal(
  tcx: TyCtxt<'tcx>,

compiler/rustc_trait_selection/src/solve/project_goals.rs

@@ -28,8 +28,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
  // To only compute normalization once for each projection we only
  // normalize if the expected term is an unconstrained inference variable.
  //
- // E.g. for `<T as Trait>::Assoc = u32` we recursively compute the goal
- // `exists<U> <T as Trait>::Assoc = U` and then take the resulting type for
+ // E.g. for `<T as Trait>::Assoc == u32` we recursively compute the goal
+ // `exists<U> <T as Trait>::Assoc == U` and then take the resulting type for
  // `U` and equate it with `u32`. This means that we don't need a separate
  // projection cache in the solver.
  if self.term_is_fully_unconstrained(goal) {

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

@@ -3759,13 +3759,13 @@ fn hint_missing_borrow<'tcx>(
  err: &mut Diagnostic,
 ) {
  let found_args = match found.kind() {
- ty::FnPtr(f) => f.inputs().skip_binder().iter(),
+ ty::FnPtr(f) => infcx.replace_bound_vars_with_placeholders(*f).inputs().iter(),
  kind => {
  span_bug!(span, "found was converted to a FnPtr above but is now {:?}", kind)
  }
  };
  let expected_args = match expected.kind() {
- ty::FnPtr(f) => f.inputs().skip_binder().iter(),
+ ty::FnPtr(f) => infcx.replace_bound_vars_with_placeholders(*f).inputs().iter(),
  kind => {
  span_bug!(span, "expected was converted to a FnPtr above but is now {:?}", kind)
  }
@@ -3776,12 +3776,12 @@ fn hint_missing_borrow<'tcx>(
 
  let args = fn_decl.inputs.iter().map(|ty| ty);
 
- fn get_deref_type_and_refs(mut ty: Ty<'_>) -> (Ty<'_>, usize) {
- let mut refs = 0;
+ fn get_deref_type_and_refs(mut ty: Ty<'_>) -> (Ty<'_>, Vec<hir::Mutability>) {
+ let mut refs = vec![];
 
- while let ty::Ref(_, new_ty, _) = ty.kind() {
+ while let ty::Ref(_, new_ty, mutbl) = ty.kind() {
  ty = *new_ty;
- refs += 1;
+ refs.push(*mutbl);
  }
 
  (ty, refs)
@@ -3795,11 +3795,21 @@ fn hint_missing_borrow<'tcx>(
  let (expected_ty, expected_refs) = get_deref_type_and_refs(*expected_arg);
 
  if infcx.can_eq(param_env, found_ty, expected_ty).is_ok() {
- if found_refs < expected_refs {
- to_borrow.push((arg.span.shrink_to_lo(), "&".repeat(expected_refs - found_refs)));
- } else if found_refs > expected_refs {
+ // FIXME: This could handle more exotic cases like mutability mismatches too!
+ if found_refs.len() < expected_refs.len()
+ && found_refs[..] == expected_refs[expected_refs.len() - found_refs.len()..]
+ {
+ to_borrow.push((
+ arg.span.shrink_to_lo(),
+ expected_refs[..expected_refs.len() - found_refs.len()]
+ .iter()
+ .map(|mutbl| format!("&{}", mutbl.prefix_str()))
+ .collect::<Vec<_>>()
+ .join(""),
+ ));
+ } else if found_refs.len() > expected_refs.len() {
  let mut span = arg.span.shrink_to_lo();
- let mut left = found_refs - expected_refs;
+ let mut left = found_refs.len() - expected_refs.len();
  let mut ty = arg;
  while let hir::TyKind::Ref(_, mut_ty) = &ty.kind && left > 0 {
  span = span.with_hi(mut_ty.ty.span.lo());

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -8,12 +8,11 @@
 //! https://rustc-dev-guide.rust-lang.org/traits/resolution.html#confirmation
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::lang_items::LangItem;
-use rustc_index::bit_set::GrowableBitSet;
 use rustc_infer::infer::InferOk;
 use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType;
 use rustc_middle::ty::{
- self, Binder, GenericArg, GenericArgKind, GenericParamDefKind, InternalSubsts, SubstsRef,
- ToPolyTraitRef, ToPredicate, TraitRef, Ty, TyCtxt,
+ self, Binder, GenericParamDefKind, InternalSubsts, SubstsRef, ToPolyTraitRef, ToPredicate,
+ TraitRef, Ty, TyCtxt,
 };
 use rustc_session::config::TraitSolver;
 use rustc_span::def_id::DefId;
@@ -1064,51 +1063,18 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
  // `Struct<T>` -> `Struct<U>`
  (&ty::Adt(def, substs_a), &ty::Adt(_, substs_b)) => {
- let maybe_unsizing_param_idx = |arg: GenericArg<'tcx>| match arg.unpack() {
- GenericArgKind::Type(ty) => match ty.kind() {
- ty::Param(p) => Some(p.index),
- _ => None,
- },
-
- // Lifetimes aren't allowed to change during unsizing.
- GenericArgKind::Lifetime(_) => None,
-
- GenericArgKind::Const(ct) => match ct.kind() {
- ty::ConstKind::Param(p) => Some(p.index),
- _ => None,
- },
- };
-
- // FIXME(eddyb) cache this (including computing `unsizing_params`)
- // by putting it in a query; it would only need the `DefId` as it
- // looks at declared field types, not anything substituted.
-
- // The last field of the structure has to exist and contain type/const parameters.
- let (tail_field, prefix_fields) =
- def.non_enum_variant().fields.split_last().ok_or(Unimplemented)?;
- let tail_field_ty = tcx.bound_type_of(tail_field.did);
-
- let mut unsizing_params = GrowableBitSet::new_empty();
- for arg in tail_field_ty.0.walk() {
- if let Some(i) = maybe_unsizing_param_idx(arg) {
- unsizing_params.insert(i);
- }
- }
-
- // Ensure none of the other fields mention the parameters used
- // in unsizing.
- for field in prefix_fields {
- for arg in tcx.type_of(field.did).walk() {
- if let Some(i) = maybe_unsizing_param_idx(arg) {
- unsizing_params.remove(i);
- }
- }
- }
-
+ let unsizing_params = tcx.unsizing_params_for_adt(def.did());
  if unsizing_params.is_empty() {
  return Err(Unimplemented);
  }
 
+ let tail_field = def
+ .non_enum_variant()
+ .fields
+ .last()
+ .expect("expected unsized ADT to have a tail field");
+ let tail_field_ty = tcx.bound_type_of(tail_field.did);
+
  // Extract `TailField<T>` and `TailField<U>` from `Struct<T>` and `Struct<U>`,
  // normalizing in the process, since `type_of` returns something directly from
  // astconv (which means it's un-normalized).

compiler/rustc_ty_utils/src/ty.rs

@@ -1,5 +1,6 @@
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir as hir;
+use rustc_index::bit_set::BitSet;
 use rustc_middle::ty::{self, Binder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt};
 use rustc_session::config::TraitSolver;
 use rustc_span::def_id::{DefId, CRATE_DEF_ID};
@@ -400,6 +401,56 @@ fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync {
  node.fn_sig().map_or(hir::IsAsync::NotAsync, |sig| sig.header.asyncness)
 }
 
+fn unsizing_params_for_adt<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> BitSet<u32> {
+ let def = tcx.adt_def(def_id);
+ let num_params = tcx.generics_of(def_id).count();
+
+ let maybe_unsizing_param_idx = |arg: ty::GenericArg<'tcx>| match arg.unpack() {
+ ty::GenericArgKind::Type(ty) => match ty.kind() {
+ ty::Param(p) => Some(p.index),
+ _ => None,
+ },
+
+ // We can't unsize a lifetime
+ ty::GenericArgKind::Lifetime(_) => None,
+
+ ty::GenericArgKind::Const(ct) => match ct.kind() {
+ ty::ConstKind::Param(p) => Some(p.index),
+ _ => None,
+ },
+ };
+
+ // FIXME(eddyb) cache this (including computing `unsizing_params`)
+ // by putting it in a query; it would only need the `DefId` as it
+ // looks at declared field types, not anything substituted.
+
+ // The last field of the structure has to exist and contain type/const parameters.
+ let Some((tail_field, prefix_fields)) =
+ def.non_enum_variant().fields.split_last() else
+ {
+ return BitSet::new_empty(num_params);
+ };
+
+ let mut unsizing_params = BitSet::new_empty(num_params);
+ for arg in tcx.bound_type_of(tail_field.did).subst_identity().walk() {
+ if let Some(i) = maybe_unsizing_param_idx(arg) {
+ unsizing_params.insert(i);
+ }
+ }
+
+ // Ensure none of the other fields mention the parameters used
+ // in unsizing.
+ for field in prefix_fields {
+ for arg in tcx.bound_type_of(field.did).subst_identity().walk() {
+ if let Some(i) = maybe_unsizing_param_idx(arg) {
+ unsizing_params.remove(i);
+ }
+ }
+ }
+
+ unsizing_params
+}
+
 pub fn provide(providers: &mut ty::query::Providers) {
  *providers = ty::query::Providers {
  asyncness,
@@ -409,6 +460,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
  instance_def_size_estimate,
  issue33140_self_ty,
  impl_defaultness,
+ unsizing_params_for_adt,
  ..*providers
  };
 }

library/std/src/lib.rs

@@ -358,7 +358,6 @@
 #![feature(const_ip)]
 #![feature(const_ipv4)]
 #![feature(const_ipv6)]
-#![feature(const_socketaddr)]
 #![feature(thread_local_internals)]
 //
 #![default_lib_allocator]

library/std/src/net/socket_addr.rs

@@ -133,7 +133,7 @@ impl SocketAddr {
  /// ```
  #[stable(feature = "ip_addr", since = "1.7.0")]
  #[must_use]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn new(ip: IpAddr, port: u16) -> SocketAddr {
  match ip {
  IpAddr::V4(a) => SocketAddr::V4(SocketAddrV4::new(a, port)),
@@ -153,7 +153,7 @@ impl SocketAddr {
  /// ```
  #[must_use]
  #[stable(feature = "ip_addr", since = "1.7.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn ip(&self) -> IpAddr {
  match *self {
  SocketAddr::V4(ref a) => IpAddr::V4(*a.ip()),
@@ -194,7 +194,7 @@ impl SocketAddr {
  /// ```
  #[must_use]
  #[stable(feature = "rust1", since = "1.0.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn port(&self) -> u16 {
  match *self {
  SocketAddr::V4(ref a) => a.port(),
@@ -238,7 +238,7 @@ impl SocketAddr {
  /// ```
  #[must_use]
  #[stable(feature = "sockaddr_checker", since = "1.16.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn is_ipv4(&self) -> bool {
  matches!(*self, SocketAddr::V4(_))
  }
@@ -260,7 +260,7 @@ impl SocketAddr {
  /// ```
  #[must_use]
  #[stable(feature = "sockaddr_checker", since = "1.16.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn is_ipv6(&self) -> bool {
  matches!(*self, SocketAddr::V6(_))
  }
@@ -280,7 +280,7 @@ impl SocketAddrV4 {
  /// ```
  #[stable(feature = "rust1", since = "1.0.0")]
  #[must_use]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn new(ip: Ipv4Addr, port: u16) -> SocketAddrV4 {
  SocketAddrV4 { ip, port }
  }
@@ -297,7 +297,7 @@ impl SocketAddrV4 {
  /// ```
  #[must_use]
  #[stable(feature = "rust1", since = "1.0.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn ip(&self) -> &Ipv4Addr {
  &self.ip
  }
@@ -330,7 +330,7 @@ impl SocketAddrV4 {
  /// ```
  #[must_use]
  #[stable(feature = "rust1", since = "1.0.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn port(&self) -> u16 {
  self.port
  }
@@ -371,7 +371,7 @@ impl SocketAddrV6 {
  /// ```
  #[stable(feature = "rust1", since = "1.0.0")]
  #[must_use]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn new(ip: Ipv6Addr, port: u16, flowinfo: u32, scope_id: u32) -> SocketAddrV6 {
  SocketAddrV6 { ip, port, flowinfo, scope_id }
  }
@@ -388,7 +388,7 @@ impl SocketAddrV6 {
  /// ```
  #[must_use]
  #[stable(feature = "rust1", since = "1.0.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn ip(&self) -> &Ipv6Addr {
  &self.ip
  }
@@ -421,7 +421,7 @@ impl SocketAddrV6 {
  /// ```
  #[must_use]
  #[stable(feature = "rust1", since = "1.0.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn port(&self) -> u16 {
  self.port
  }
@@ -464,7 +464,7 @@ impl SocketAddrV6 {
  /// ```
  #[must_use]
  #[stable(feature = "rust1", since = "1.0.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn flowinfo(&self) -> u32 {
  self.flowinfo
  }
@@ -504,7 +504,7 @@ impl SocketAddrV6 {
  /// ```
  #[must_use]
  #[stable(feature = "rust1", since = "1.0.0")]
- #[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
+ #[rustc_const_stable(feature = "const_socketaddr", since = "CURRENT_RUSTC_VERSION")]
  pub const fn scope_id(&self) -> u32 {
  self.scope_id
  }