Rollup of 9 pull requests

Cargo.lock

@@ -5608,6 +5608,7 @@ dependencies = [
  "lazy_static",
  "miropt-test-tools",
  "regex",
+ "semver",
  "termcolor",
  "walkdir",
 ]

compiler/rustc_index/src/vec.rs

@@ -207,7 +207,12 @@ impl<I: Idx, T> IndexVec<I, T> {
         &'a mut self,
         range: R,
     ) -> impl Iterator<Item = (I, T)> + 'a {
-        self.raw.drain(range).enumerate().map(|(n, t)| (I::new(n), t))
+        let begin = match range.start_bound() {
+            std::ops::Bound::Included(i) => *i,
+            std::ops::Bound::Excluded(i) => i.checked_add(1).unwrap(),
+            std::ops::Bound::Unbounded => 0,
+        };
+        self.raw.drain(range).enumerate().map(move |(n, t)| (I::new(begin + n), t))
     }
 
     #[inline]

compiler/rustc_infer/src/infer/opaque_types.rs

@@ -479,7 +479,7 @@ where
             }
 
             ty::Alias(ty::Opaque, ty::AliasTy { def_id, ref substs, .. }) => {
-                // Skip lifetime paramters that are not captures.
+                // Skip lifetime parameters that are not captures.
                 let variances = self.tcx.variances_of(*def_id);
 
                 for (v, s) in std::iter::zip(variances, substs.iter()) {
@@ -492,7 +492,7 @@ where
             ty::Alias(ty::Projection, proj)
                 if self.tcx.def_kind(proj.def_id) == DefKind::ImplTraitPlaceholder =>
             {
-                // Skip lifetime paramters that are not captures.
+                // Skip lifetime parameters that are not captures.
                 let variances = self.tcx.variances_of(proj.def_id);
 
                 for (v, s) in std::iter::zip(variances, proj.substs.iter()) {

compiler/rustc_lint_defs/src/builtin.rs

@@ -708,7 +708,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust
+    /// ```rust,compile_fail
     /// pub enum Enum {
     ///     Foo,
     ///     Bar,
@@ -743,7 +743,7 @@ declare_lint! {
     /// [identifier pattern]: https://doc.rust-lang.org/reference/patterns.html#identifier-patterns
     /// [path pattern]: https://doc.rust-lang.org/reference/patterns.html#path-patterns
     pub BINDINGS_WITH_VARIANT_NAME,
-    Warn,
+    Deny,
     "detects pattern bindings with the same name as one of the matched variants"
 }
 

compiler/rustc_resolve/src/diagnostics.rs

@@ -2125,9 +2125,15 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
 
                 let source_map = self.r.session.source_map();
 
+                // Make sure this is actually crate-relative.
+                let is_definitely_crate = import
+                    .module_path
+                    .first()
+                    .map_or(false, |f| f.ident.name != kw::SelfLower && f.ident.name != kw::Super);
+
                 // Add the import to the start, with a `{` if required.
                 let start_point = source_map.start_point(after_crate_name);
-                if let Ok(start_snippet) = source_map.span_to_snippet(start_point) {
+                if is_definitely_crate && let Ok(start_snippet) = source_map.span_to_snippet(start_point) {
                     corrections.push((
                         start_point,
                         if has_nested {
@@ -2139,11 +2145,17 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                             format!("{{{}, {}", import_snippet, start_snippet)
                         },
                     ));
-                }
 
-                // Add a `};` to the end if nested, matching the `{` added at the start.
-                if !has_nested {
-                    corrections.push((source_map.end_point(after_crate_name), "};".to_string()));
+                    // Add a `};` to the end if nested, matching the `{` added at the start.
+                    if !has_nested {
+                        corrections.push((source_map.end_point(after_crate_name), "};".to_string()));
+                    }
+                } else {
+                    // If the root import is module-relative, add the import separately
+                    corrections.push((
+                        import.use_span.shrink_to_lo(),
+                        format!("use {module_name}::{import_snippet};\n"),
+                    ));
                 }
             }
 

compiler/rustc_trait_selection/src/solve/assembly.rs

@@ -1,7 +1,7 @@
 //! Code shared by trait and projection goals for candidate assembly.
 
 use super::infcx_ext::InferCtxtExt;
-use super::{CanonicalResponse, EvalCtxt, Goal, QueryResult};
+use super::{CanonicalResponse, Certainty, EvalCtxt, Goal, MaybeCause, QueryResult};
 use rustc_hir::def_id::DefId;
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::util::elaborate_predicates;
@@ -79,7 +79,7 @@ pub(super) enum CandidateSource {
     AliasBound(usize),
 }
 
-pub(super) trait GoalKind<'tcx>: TypeFoldable<'tcx> + Copy {
+pub(super) trait GoalKind<'tcx>: TypeFoldable<'tcx> + Copy + Eq {
     fn self_ty(self) -> Ty<'tcx>;
 
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self;
@@ -117,13 +117,43 @@ pub(super) trait GoalKind<'tcx>: TypeFoldable<'tcx> + Copy {
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
+
+    fn consider_builtin_pointer_sized_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
+
+    fn consider_builtin_fn_trait_candidates(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+        kind: ty::ClosureKind,
+    ) -> QueryResult<'tcx>;
+
+    fn consider_builtin_tuple_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
     pub(super) fn assemble_and_evaluate_candidates<G: GoalKind<'tcx>>(
         &mut self,
         goal: Goal<'tcx, G>,
     ) -> Vec<Candidate<'tcx>> {
+        debug_assert_eq!(goal, self.infcx.resolve_vars_if_possible(goal));
+
+        // HACK: `_: Trait` is ambiguous, because it may be satisfied via a builtin rule,
+        // object bound, alias bound, etc. We are unable to determine this until we can at
+        // least structually resolve the type one layer.
+        if goal.predicate.self_ty().is_ty_var() {
+            return vec![Candidate {
+                source: CandidateSource::BuiltinImpl,
+                result: self
+                    .make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity))
+                    .unwrap(),
+            }];
+        }
+
         let mut candidates = Vec::new();
 
         self.assemble_candidates_after_normalizing_self_ty(goal, &mut candidates);
@@ -169,6 +199,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
                 Ok((_, certainty)) => certainty,
                 Err(NoSolution) => return,
             };
+            let normalized_ty = self.infcx.resolve_vars_if_possible(normalized_ty);
 
             // NOTE: Alternatively we could call `evaluate_goal` here and only have a `Normalized` candidate.
             // This doesn't work as long as we use `CandidateSource` in winnowing.
@@ -224,6 +255,12 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             || lang_items.clone_trait() == Some(trait_def_id)
         {
             G::consider_builtin_copy_clone_candidate(self, goal)
+        } else if lang_items.pointer_sized() == Some(trait_def_id) {
+            G::consider_builtin_pointer_sized_candidate(self, goal)
+        } else if let Some(kind) = self.tcx().fn_trait_kind_from_def_id(trait_def_id) {
+            G::consider_builtin_fn_trait_candidates(self, goal, kind)
+        } else if lang_items.tuple_trait() == Some(trait_def_id) {
+            G::consider_builtin_tuple_candidate(self, goal)
         } else {
             Err(NoSolution)
         };

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -52,7 +52,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
             .drain(..)
             .map(|obligation| FulfillmentError {
                 obligation: obligation.clone(),
-                code: FulfillmentErrorCode::CodeSelectionError(SelectionError::Unimplemented),
+                code: FulfillmentErrorCode::CodeAmbiguity,
                 root_obligation: obligation,
             })
             .collect()
@@ -75,7 +75,9 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
                     Err(NoSolution) => {
                         errors.push(FulfillmentError {
                             obligation: obligation.clone(),
-                            code: FulfillmentErrorCode::CodeAmbiguity,
+                            code: FulfillmentErrorCode::CodeSelectionError(
+                                SelectionError::Unimplemented,
+                            ),
                             root_obligation: obligation,
                         });
                         continue;

compiler/rustc_trait_selection/src/solve/project_goals.rs

@@ -2,6 +2,7 @@ use crate::traits::{specialization_graph, translate_substs};
 
 use super::assembly::{self, Candidate, CandidateSource};
 use super::infcx_ext::InferCtxtExt;
+use super::trait_goals::structural_traits;
 use super::{Certainty, EvalCtxt, Goal, MaybeCause, QueryResult};
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def::DefKind;
@@ -11,9 +12,9 @@ use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::specialization_graph::LeafDef;
 use rustc_infer::traits::Reveal;
 use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
-use rustc_middle::ty::TypeVisitable;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::ty::{ProjectionPredicate, TypeSuperVisitable, TypeVisitor};
+use rustc_middle::ty::{ToPredicate, TypeVisitable};
 use rustc_span::DUMMY_SP;
 use std::iter;
 use std::ops::ControlFlow;
@@ -351,6 +352,46 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
     ) -> QueryResult<'tcx> {
         bug!("`Copy`/`Clone` does not have an associated type: {:?}", goal);
     }
+
+    fn consider_builtin_pointer_sized_candidate(
+        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        bug!("`PointerSized` does not have an associated type: {:?}", goal);
+    }
+
+    fn consider_builtin_fn_trait_candidates(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+        goal_kind: ty::ClosureKind,
+    ) -> QueryResult<'tcx> {
+        if let Some(tupled_inputs_and_output) =
+            structural_traits::extract_tupled_inputs_and_output_from_callable(
+                ecx.tcx(),
+                goal.predicate.self_ty(),
+                goal_kind,
+            )?
+        {
+            let pred = tupled_inputs_and_output
+                .map_bound(|(inputs, output)| ty::ProjectionPredicate {
+                    projection_ty: ecx
+                        .tcx()
+                        .mk_alias_ty(goal.predicate.def_id(), [goal.predicate.self_ty(), inputs]),
+                    term: output.into(),
+                })
+                .to_predicate(ecx.tcx());
+            Self::consider_assumption(ecx, goal, pred)
+        } else {
+            ecx.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity))
+        }
+    }
+
+    fn consider_builtin_tuple_candidate(
+        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        bug!("`Tuple` does not have an associated type: {:?}", goal);
+    }
 }
 
 /// This behavior is also implemented in `rustc_ty_utils` and in the old `project` code.

compiler/rustc_trait_selection/src/solve/trait_goals.rs

@@ -4,16 +4,16 @@ use std::iter;
 
 use super::assembly::{self, Candidate, CandidateSource};
 use super::infcx_ext::InferCtxtExt;
-use super::{EvalCtxt, Goal, QueryResult};
+use super::{Certainty, EvalCtxt, Goal, MaybeCause, QueryResult};
 use rustc_hir::def_id::DefId;
 use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
-use rustc_middle::ty::TraitPredicate;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt};
+use rustc_middle::ty::{TraitPredicate, TypeVisitable};
 use rustc_span::DUMMY_SP;
 
-mod structural_traits;
+pub mod structural_traits;
 
 impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     fn self_ty(self) -> Ty<'tcx> {
@@ -127,6 +127,64 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
             structural_traits::instantiate_constituent_tys_for_copy_clone_trait,
         )
     }
+
+    fn consider_builtin_pointer_sized_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        if goal.predicate.self_ty().has_non_region_infer() {
+            return ecx.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity));
+        }
+
+        let tcx = ecx.tcx();
+        let self_ty = tcx.erase_regions(goal.predicate.self_ty());
+
+        if let Ok(layout) = tcx.layout_of(goal.param_env.and(self_ty))
+            &&  let usize_layout = tcx.layout_of(ty::ParamEnv::empty().and(tcx.types.usize)).unwrap().layout
+            && layout.layout.size() == usize_layout.size()
+            && layout.layout.align().abi == usize_layout.align().abi
+        {
+            // FIXME: We could make this faster by making a no-constraints response
+            ecx.make_canonical_response(Certainty::Yes)
+        } else {
+            Err(NoSolution)
+        }
+    }
+
+    fn consider_builtin_fn_trait_candidates(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+        goal_kind: ty::ClosureKind,
+    ) -> QueryResult<'tcx> {
+        if let Some(tupled_inputs_and_output) =
+            structural_traits::extract_tupled_inputs_and_output_from_callable(
+                ecx.tcx(),
+                goal.predicate.self_ty(),
+                goal_kind,
+            )?
+        {
+            let pred = tupled_inputs_and_output
+                .map_bound(|(inputs, _)| {
+                    ecx.tcx()
+                        .mk_trait_ref(goal.predicate.def_id(), [goal.predicate.self_ty(), inputs])
+                })
+                .to_predicate(ecx.tcx());
+            Self::consider_assumption(ecx, goal, pred)
+        } else {
+            ecx.make_canonical_response(Certainty::Maybe(MaybeCause::Ambiguity))
+        }
+    }
+
+    fn consider_builtin_tuple_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        if let ty::Tuple(..) = goal.predicate.self_ty().kind() {
+            ecx.make_canonical_response(Certainty::Yes)
+        } else {
+            Err(NoSolution)
+        }
+    }
 }
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {