Rollup of 7 pull requests

compiler/rustc_hir_analysis/src/lib.rs

@@ -181,14 +181,11 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
  })?;
  }
 
- tcx.sess.track_errors(|| {
- tcx.sess.time("impl_wf_inference", || {
- tcx.hir().for_each_module(|module| tcx.ensure().check_mod_impl_wf(module))
- });
- })?;
-
  tcx.sess.track_errors(|| {
  tcx.sess.time("coherence_checking", || {
+ // Check impls constrain their parameters
+ tcx.hir().for_each_module(|module| tcx.ensure().check_mod_impl_wf(module));
+
  for &trait_def_id in tcx.all_local_trait_impls(()).keys() {
  tcx.ensure().coherent_trait(trait_def_id);
  }

compiler/rustc_middle/src/query/mod.rs

@@ -341,7 +341,7 @@ rustc_queries! {
 
  query opaque_types_defined_by(
  key: LocalDefId
- ) -> &'tcx [LocalDefId] {
+ ) -> &'tcx ty::List<LocalDefId> {
  desc {
  |tcx| "computing the opaque types defined by `{}`",
  tcx.def_path_str(key.to_def_id())

compiler/rustc_middle/src/ty/context.rs

@@ -161,6 +161,7 @@ pub struct CtxtInterners<'tcx> {
  external_constraints: InternedSet<'tcx, ExternalConstraintsData<'tcx>>,
  predefined_opaques_in_body: InternedSet<'tcx, PredefinedOpaquesData<'tcx>>,
  fields: InternedSet<'tcx, List<FieldIdx>>,
+ local_def_ids: InternedSet<'tcx, List<LocalDefId>>,
 }
 
 impl<'tcx> CtxtInterners<'tcx> {
@@ -186,6 +187,7 @@ impl<'tcx> CtxtInterners<'tcx> {
  external_constraints: Default::default(),
  predefined_opaques_in_body: Default::default(),
  fields: Default::default(),
+ local_def_ids: Default::default(),
  }
  }
 
@@ -1572,6 +1574,7 @@ slice_interners!(
  place_elems: pub mk_place_elems(PlaceElem<'tcx>),
  bound_variable_kinds: pub mk_bound_variable_kinds(ty::BoundVariableKind),
  fields: pub mk_fields(FieldIdx),
+ local_def_ids: intern_local_def_ids(LocalDefId),
 );
 
 impl<'tcx> TyCtxt<'tcx> {
@@ -1801,6 +1804,13 @@ impl<'tcx> TyCtxt<'tcx> {
  self.intern_clauses(clauses)
  }
 
+ pub fn mk_local_def_ids(self, clauses: &[LocalDefId]) -> &'tcx List<LocalDefId> {
+ // FIXME consider asking the input slice to be sorted to avoid
+ // re-interning permutations, in which case that would be asserted
+ // here.
+ self.intern_local_def_ids(clauses)
+ }
+
  pub fn mk_const_list_from_iter<I, T>(self, iter: I) -> T::Output
  where
  I: Iterator<Item = T>,

compiler/rustc_mir_build/messages.ftl

@@ -379,6 +379,5 @@ mir_build_unused_unsafe = unnecessary `unsafe` block
  .label = unnecessary `unsafe` block
 
 mir_build_unused_unsafe_enclosing_block_label = because it's nested under this `unsafe` block
-mir_build_unused_unsafe_enclosing_fn_label = because it's nested under this `unsafe` fn
 
 mir_build_variant_defined_here = not covered

compiler/rustc_mir_build/src/check_unsafety.rs

@@ -13,6 +13,7 @@ use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
 
+use std::mem;
 use std::ops::Bound;
 
 struct UnsafetyVisitor<'a, 'tcx> {
@@ -24,7 +25,6 @@ struct UnsafetyVisitor<'a, 'tcx> {
  /// The current "safety context". This notably tracks whether we are in an
  /// `unsafe` block, and whether it has been used.
  safety_context: SafetyContext,
- body_unsafety: BodyUnsafety,
  /// The `#[target_feature]` attributes of the body. Used for checking
  /// calls to functions with `#[target_feature]` (RFC 2396).
  body_target_features: &'tcx [Symbol],
@@ -34,43 +34,50 @@ struct UnsafetyVisitor<'a, 'tcx> {
  in_union_destructure: bool,
  param_env: ParamEnv<'tcx>,
  inside_adt: bool,
+ warnings: &'a mut Vec<UnusedUnsafeWarning>,
 }
 
 impl<'tcx> UnsafetyVisitor<'_, 'tcx> {
  fn in_safety_context(&mut self, safety_context: SafetyContext, f: impl FnOnce(&mut Self)) {
- if let (
- SafetyContext::UnsafeBlock { span: enclosing_span, .. },
- SafetyContext::UnsafeBlock { span: block_span, hir_id, .. },
- ) = (self.safety_context, safety_context)
+ let prev_context = mem::replace(&mut self.safety_context, safety_context);
+
+ f(self);
+
+ let safety_context = mem::replace(&mut self.safety_context, prev_context);
+ if let SafetyContext::UnsafeBlock { used, span, hir_id, nested_used_blocks } =
+ safety_context
  {
- self.warn_unused_unsafe(
- hir_id,
- block_span,
- Some(UnusedUnsafeEnclosing::Block {
- span: self.tcx.sess.source_map().guess_head_span(enclosing_span),
- }),
- );
- f(self);
- } else {
- let prev_context = self.safety_context;
- self.safety_context = safety_context;
+ if !used {
+ self.warn_unused_unsafe(hir_id, span, None);
 
- f(self);
+ if let SafetyContext::UnsafeBlock {
+ nested_used_blocks: ref mut prev_nested_used_blocks,
+ ..
+ } = self.safety_context
+ {
+ prev_nested_used_blocks.extend(nested_used_blocks);
+ }
+ } else {
+ for block in nested_used_blocks {
+ self.warn_unused_unsafe(
+ block.hir_id,
+ block.span,
+ Some(UnusedUnsafeEnclosing::Block {
+ span: self.tcx.sess.source_map().guess_head_span(span),
+ }),
+ );
+ }
 
- if let SafetyContext::UnsafeBlock { used: false, span, hir_id } = self.safety_context {
- self.warn_unused_unsafe(
- hir_id,
- span,
- if self.unsafe_op_in_unsafe_fn_allowed() {
- self.body_unsafety
- .unsafe_fn_sig_span()
- .map(|span| UnusedUnsafeEnclosing::Function { span })
- } else {
- None
- },
- );
+ match self.safety_context {
+ SafetyContext::UnsafeBlock {
+ nested_used_blocks: ref mut prev_nested_used_blocks,
+ ..
+ } => {
+ prev_nested_used_blocks.push(NestedUsedBlock { hir_id, span });
+ }
+ _ => (),
+ }
  }
- self.safety_context = prev_context;
  }
  }
 
@@ -102,18 +109,12 @@ impl<'tcx> UnsafetyVisitor<'_, 'tcx> {
  }
 
  fn warn_unused_unsafe(
- &self,
+ &mut self,
  hir_id: hir::HirId,
  block_span: Span,
  enclosing_unsafe: Option<UnusedUnsafeEnclosing>,
  ) {
- let block_span = self.tcx.sess.source_map().guess_head_span(block_span);
- self.tcx.emit_spanned_lint(
- UNUSED_UNSAFE,
- hir_id,
- block_span,
- UnusedUnsafe { span: block_span, enclosing: enclosing_unsafe },
- );
+ self.warnings.push(UnusedUnsafeWarning { hir_id, block_span, enclosing_unsafe });
  }
 
  /// Whether the `unsafe_op_in_unsafe_fn` lint is `allow`ed at the current HIR node.
@@ -128,7 +129,14 @@ impl<'tcx> UnsafetyVisitor<'_, 'tcx> {
  self.tcx.ensure_with_value().mir_built(def);
  let inner_thir = &inner_thir.steal();
  let hir_context = self.tcx.hir().local_def_id_to_hir_id(def);
- let mut inner_visitor = UnsafetyVisitor { thir: inner_thir, hir_context, ..*self };
+ let safety_context = mem::replace(&mut self.safety_context, SafetyContext::Safe);
+ let mut inner_visitor = UnsafetyVisitor {
+ thir: inner_thir,
+ hir_context,
+ safety_context,
+ warnings: self.warnings,
+ ..*self
+ };
  inner_visitor.visit_expr(&inner_thir[expr]);
  // Unsafe blocks can be used in the inner body, make sure to take it into account
  self.safety_context = inner_visitor.safety_context;
@@ -195,8 +203,15 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
  });
  }
  BlockSafety::ExplicitUnsafe(hir_id) => {
+ let used =
+ matches!(self.tcx.lint_level_at_node(UNUSED_UNSAFE, hir_id), (Level::Allow, _));
  self.in_safety_context(
- SafetyContext::UnsafeBlock { span: block.span, hir_id, used: false },
+ SafetyContext::UnsafeBlock {
+ span: block.span,
+ hir_id,
+ used,
+ nested_used_blocks: Vec::new(),
+ },
  |this| visit::walk_block(this, block),
  );
  }
@@ -481,36 +496,29 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
  }
 }
 
-#[derive(Clone, Copy)]
+#[derive(Clone)]
 enum SafetyContext {
  Safe,
  BuiltinUnsafeBlock,
  UnsafeFn,
- UnsafeBlock { span: Span, hir_id: hir::HirId, used: bool },
+ UnsafeBlock {
+ span: Span,
+ hir_id: hir::HirId,
+ used: bool,
+ nested_used_blocks: Vec<NestedUsedBlock>,
+ },
 }
 
 #[derive(Clone, Copy)]
-enum BodyUnsafety {
- /// The body is not unsafe.
- Safe,
- /// The body is an unsafe function. The span points to
- /// the signature of the function.
- Unsafe(Span),
+struct NestedUsedBlock {
+ hir_id: hir::HirId,
+ span: Span,
 }
 
-impl BodyUnsafety {
- /// Returns whether the body is unsafe.
- fn is_unsafe(&self) -> bool {
- matches!(self, BodyUnsafety::Unsafe(_))
- }
-
- /// If the body is unsafe, returns the `Span` of its signature.
- fn unsafe_fn_sig_span(self) -> Option<Span> {
- match self {
- BodyUnsafety::Unsafe(span) => Some(span),
- BodyUnsafety::Safe => None,
- }
- }
+struct UnusedUnsafeWarning {
+ hir_id: hir::HirId,
+ block_span: Span,
+ enclosing_unsafe: Option<UnusedUnsafeEnclosing>,
 }
 
 #[derive(Clone, Copy, PartialEq)]
@@ -803,27 +811,37 @@ pub fn thir_check_unsafety(tcx: TyCtxt<'_>, def: LocalDefId) {
  }
 
  let hir_id = tcx.hir().local_def_id_to_hir_id(def);
- let body_unsafety = tcx.hir().fn_sig_by_hir_id(hir_id).map_or(BodyUnsafety::Safe, |fn_sig| {
+ let safety_context = tcx.hir().fn_sig_by_hir_id(hir_id).map_or(SafetyContext::Safe, |fn_sig| {
  if fn_sig.header.unsafety == hir::Unsafety::Unsafe {
- BodyUnsafety::Unsafe(fn_sig.span)
+ SafetyContext::UnsafeFn
  } else {
- BodyUnsafety::Safe
+ SafetyContext::Safe
  }
  });
  let body_target_features = &tcx.body_codegen_attrs(def.to_def_id()).target_features;
- let safety_context =
- if body_unsafety.is_unsafe() { SafetyContext::UnsafeFn } else { SafetyContext::Safe };
+ let mut warnings = Vec::new();
  let mut visitor = UnsafetyVisitor {
  tcx,
  thir,
  safety_context,
  hir_context: hir_id,
- body_unsafety,
  body_target_features,
  assignment_info: None,
  in_union_destructure: false,
  param_env: tcx.param_env(def),
  inside_adt: false,
+ warnings: &mut warnings,
  };
  visitor.visit_expr(&thir[expr]);
+
+ warnings.sort_by_key(|w| w.block_span);
+ for UnusedUnsafeWarning { hir_id, block_span, enclosing_unsafe } in warnings {
+ let block_span = tcx.sess.source_map().guess_head_span(block_span);
+ tcx.emit_spanned_lint(
+ UNUSED_UNSAFE,
+ hir_id,
+ block_span,
+ UnusedUnsafe { span: block_span, enclosing: enclosing_unsafe },
+ );
+ }
 }

compiler/rustc_mir_build/src/errors.rs

@@ -392,11 +392,6 @@ pub enum UnusedUnsafeEnclosing {
  #[primary_span]
  span: Span,
  },
- #[label(mir_build_unused_unsafe_enclosing_fn_label)]
- Function {
- #[primary_span]
- span: Span,
- },
 }
 
 pub(crate) struct NonExhaustivePatternsTypeNotEmpty<'p, 'tcx, 'm> {

compiler/rustc_mir_build/src/lib.rs

@@ -20,7 +20,7 @@ mod build;
 mod check_unsafety;
 mod errors;
 pub mod lints;
-pub mod thir;
+mod thir;
 
 use rustc_middle::query::Providers;
 

compiler/rustc_ty_utils/src/opaque_types.rs

@@ -264,7 +264,10 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for OpaqueTypeCollector<'tcx> {
  }
 }
 
-fn opaque_types_defined_by<'tcx>(tcx: TyCtxt<'tcx>, item: LocalDefId) -> &'tcx [LocalDefId] {
+fn opaque_types_defined_by<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ item: LocalDefId,
+) -> &'tcx ty::List<LocalDefId> {
  let kind = tcx.def_kind(item);
  trace!(?kind);
  let mut collector = OpaqueTypeCollector::new(tcx, item);
@@ -306,7 +309,7 @@ fn opaque_types_defined_by<'tcx>(tcx: TyCtxt<'tcx>, item: LocalDefId) -> &'tcx [
  collector.opaques.extend(tcx.opaque_types_defined_by(tcx.local_parent(item)));
  }
  }
- tcx.arena.alloc_from_iter(collector.opaques)
+ tcx.mk_local_def_ids(&collector.opaques)
 }
 
 pub(super) fn provide(providers: &mut Providers) {

library/core/src/ops/coroutine.rs

@@ -29,7 +29,7 @@ pub enum CoroutineState<Y, R> {
 
 /// The trait implemented by builtin coroutine types.
 ///
-/// Coroutines, also commonly referred to as coroutines, are currently an
+/// Coroutines are currently an
 /// experimental language feature in Rust. Added in [RFC 2033] coroutines are
 /// currently intended to primarily provide a building block for async/await
 /// syntax but will likely extend to also providing an ergonomic definition for

src/doc/unstable-book/src/language-features/coroutines.md

@@ -18,7 +18,7 @@ Coroutines are an extra-unstable feature in the compiler right now. Added in
 [RFC 2033] they're mostly intended right now as a information/constraint
 gathering phase. The intent is that experimentation can happen on the nightly
 compiler before actual stabilization. A further RFC will be required to
-stabilize coroutines/coroutines and will likely contain at least a few small
+stabilize coroutines and will likely contain at least a few small
 tweaks to the overall design.
 
 [RFC 2033]: https://github.com/rust-lang/rfcs/pull/2033