Rollup of 6 pull requests

compiler/rustc_ast_lowering/src/expr.rs

@@ -618,9 +618,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
     /// Desugar `<expr>.await` into:
     /// ```rust
     /// match ::std::future::IntoFuture::into_future(<expr>) {
-    ///     mut pinned => loop {
+    ///     mut __awaitee => loop {
     ///         match unsafe { ::std::future::Future::poll(
-    ///             <::std::pin::Pin>::new_unchecked(&mut pinned),
+    ///             <::std::pin::Pin>::new_unchecked(&mut __awaitee),
     ///             ::std::future::get_context(task_context),
     ///         ) } {
     ///             ::std::task::Poll::Ready(result) => break result,
@@ -657,21 +657,24 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let expr = self.lower_expr_mut(expr);
         let expr_hir_id = expr.hir_id;
 
-        let pinned_ident = Ident::with_dummy_span(sym::pinned);
-        let (pinned_pat, pinned_pat_hid) =
-            self.pat_ident_binding_mode(span, pinned_ident, hir::BindingAnnotation::Mutable);
+        // Note that the name of this binding must not be changed to something else because
+        // debuggers and debugger extensions expect it to be called `__awaitee`. They use
+        // this name to identify what is being awaited by a suspended async functions.
+        let awaitee_ident = Ident::with_dummy_span(sym::__awaitee);
+        let (awaitee_pat, awaitee_pat_hid) =
+            self.pat_ident_binding_mode(span, awaitee_ident, hir::BindingAnnotation::Mutable);
 
         let task_context_ident = Ident::with_dummy_span(sym::_task_context);
 
         // unsafe {
         //     ::std::future::Future::poll(
-        //         ::std::pin::Pin::new_unchecked(&mut pinned),
+        //         ::std::pin::Pin::new_unchecked(&mut __awaitee),
         //         ::std::future::get_context(task_context),
         //     )
         // }
         let poll_expr = {
-            let pinned = self.expr_ident(span, pinned_ident, pinned_pat_hid);
-            let ref_mut_pinned = self.expr_mut_addr_of(span, pinned);
+            let awaitee = self.expr_ident(span, awaitee_ident, awaitee_pat_hid);
+            let ref_mut_awaitee = self.expr_mut_addr_of(span, awaitee);
             let task_context = if let Some(task_context_hid) = self.task_context {
                 self.expr_ident_mut(span, task_context_ident, task_context_hid)
             } else {
@@ -681,7 +684,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let new_unchecked = self.expr_call_lang_item_fn_mut(
                 span,
                 hir::LangItem::PinNewUnchecked,
-                arena_vec![self; ref_mut_pinned],
+                arena_vec![self; ref_mut_awaitee],
                 Some(expr_hir_id),
             );
             let get_context = self.expr_call_lang_item_fn_mut(
@@ -782,8 +785,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
             span: self.lower_span(span),
         });
 
-        // mut pinned => loop { ... }
-        let pinned_arm = self.arm(pinned_pat, loop_expr);
+        // mut __awaitee => loop { ... }
+        let awaitee_arm = self.arm(awaitee_pat, loop_expr);
 
         // `match ::std::future::IntoFuture::into_future(<expr>) { ... }`
         let into_future_span = self.mark_span_with_reason(
@@ -799,11 +802,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
         );
 
         // match <into_future_expr> {
-        //     mut pinned => loop { .. }
+        //     mut __awaitee => loop { .. }
         // }
         hir::ExprKind::Match(
             into_future_expr,
-            arena_vec![self; pinned_arm],
+            arena_vec![self; awaitee_arm],
             hir::MatchSource::AwaitDesugar,
         )
     }

compiler/rustc_feature/src/active.rs

@@ -400,6 +400,8 @@ declare_features! (
     (active, generic_arg_infer, "1.55.0", Some(85077), None),
     /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598).
     (active, generic_associated_types, "1.23.0", Some(44265), None),
+    /// An extension to the `generic_associated_types` feature, allowing incomplete features.
+    (incomplete, generic_associated_types_extended, "1.61.0", Some(95451), None),
     /// Allows non-trivial generic constants which have to have wfness manually propagated to callers
     (incomplete, generic_const_exprs, "1.56.0", Some(76560), None),
     /// Allows using `..X`, `..=X`, `...X`, and `X..` as a pattern.

compiler/rustc_middle/src/ty/fold.rs

@@ -1379,3 +1379,50 @@ impl<'tcx> TypeVisitor<'tcx> for LateBoundRegionsCollector {
         ControlFlow::CONTINUE
     }
 }
+
+/// Finds the max universe present
+pub struct MaxUniverse {
+    max_universe: ty::UniverseIndex,
+}
+
+impl MaxUniverse {
+    pub fn new() -> Self {
+        MaxUniverse { max_universe: ty::UniverseIndex::ROOT }
+    }
+
+    pub fn max_universe(self) -> ty::UniverseIndex {
+        self.max_universe
+    }
+}
+
+impl<'tcx> TypeVisitor<'tcx> for MaxUniverse {
+    fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
+        if let ty::Placeholder(placeholder) = t.kind() {
+            self.max_universe = ty::UniverseIndex::from_u32(
+                self.max_universe.as_u32().max(placeholder.universe.as_u32()),
+            );
+        }
+
+        t.super_visit_with(self)
+    }
+
+    fn visit_const(&mut self, c: ty::consts::Const<'tcx>) -> ControlFlow<Self::BreakTy> {
+        if let ty::ConstKind::Placeholder(placeholder) = c.val() {
+            self.max_universe = ty::UniverseIndex::from_u32(
+                self.max_universe.as_u32().max(placeholder.universe.as_u32()),
+            );
+        }
+
+        c.super_visit_with(self)
+    }
+
+    fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
+        if let ty::RePlaceholder(placeholder) = *r {
+            self.max_universe = ty::UniverseIndex::from_u32(
+                self.max_universe.as_u32().max(placeholder.universe.as_u32()),
+            );
+        }
+
+        ControlFlow::CONTINUE
+    }
+}

compiler/rustc_span/src/symbol.rs

@@ -272,6 +272,7 @@ symbols! {
         __D,
         __H,
         __S,
+        __awaitee,
         __try_var,
         _d,
         _e,
@@ -722,6 +723,7 @@ symbols! {
         generators,
         generic_arg_infer,
         generic_associated_types,
+        generic_associated_types_extended,
         generic_const_exprs,
         generic_param_attrs,
         get_context,
@@ -1018,7 +1020,6 @@ symbols! {
         pattern_parentheses,
         phantom_data,
         pin,
-        pinned,
         platform_intrinsics,
         plugin,
         plugin_registrar,

compiler/rustc_target/src/abi/mod.rs

@@ -279,30 +279,16 @@ impl ToJson for Endian {
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Encodable, Decodable)]
 #[derive(HashStable_Generic)]
 pub struct Size {
-    // The top 3 bits are ALWAYS zero.
     raw: u64,
 }
 
 impl Size {
     pub const ZERO: Size = Size { raw: 0 };
 
     /// Rounds `bits` up to the next-higher byte boundary, if `bits` is
-    /// is not aligned.
+    /// not a multiple of 8.
     pub fn from_bits(bits: impl TryInto<u64>) -> Size {
         let bits = bits.try_into().ok().unwrap();
-
-        #[cold]
-        fn overflow(bits: u64) -> ! {
-            panic!("Size::from_bits({}) has overflowed", bits);
-        }
-
-        // This is the largest value of `bits` that does not cause overflow
-        // during rounding, and guarantees that the resulting number of bytes
-        // cannot cause overflow when multiplied by 8.
-        if bits > 0xffff_ffff_ffff_fff8 {
-            overflow(bits);
-        }
-
         // Avoid potential overflow from `bits + 7`.
         Size { raw: bits / 8 + ((bits % 8) + 7) / 8 }
     }
@@ -325,7 +311,12 @@ impl Size {
 
     #[inline]
     pub fn bits(self) -> u64 {
-        self.raw << 3
+        #[cold]
+        fn overflow(bytes: u64) -> ! {
+            panic!("Size::bits: {} bytes in bits doesn't fit in u64", bytes)
+        }
+
+        self.bytes().checked_mul(8).unwrap_or_else(|| overflow(self.bytes()))
     }
 
     #[inline]

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -5,6 +5,7 @@ use super::*;
 
 use crate::infer::region_constraints::{Constraint, RegionConstraintData};
 use crate::infer::InferCtxt;
+use crate::traits::project::ProjectAndUnifyResult;
 use rustc_middle::ty::fold::TypeFolder;
 use rustc_middle::ty::{Region, RegionVid, Term};
 
@@ -751,19 +752,19 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                     debug!("Projecting and unifying projection predicate {:?}", predicate);
 
                     match project::poly_project_and_unify_type(select, &obligation.with(p)) {
-                        Err(e) => {
+                        ProjectAndUnifyResult::MismatchedProjectionTypes(e) => {
                             debug!(
                                 "evaluate_nested_obligations: Unable to unify predicate \
                                  '{:?}' '{:?}', bailing out",
                                 ty, e
                             );
                             return false;
                         }
-                        Ok(Err(project::InProgress)) => {
+                        ProjectAndUnifyResult::Recursive => {
                             debug!("evaluate_nested_obligations: recursive projection predicate");
                             return false;
                         }
-                        Ok(Ok(Some(v))) => {
+                        ProjectAndUnifyResult::Holds(v) => {
                             // We only care about sub-obligations
                             // when we started out trying to unify
                             // some inference variables. See the comment above
@@ -782,7 +783,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                                 }
                             }
                         }
-                        Ok(Ok(None)) => {
+                        ProjectAndUnifyResult::FailedNormalization => {
                             // It's ok not to make progress when have no inference variables -
                             // in that case, we were only performing unification to check if an
                             // error occurred (which would indicate that it's impossible for our

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -14,7 +14,7 @@ use rustc_middle::ty::{self, Binder, Const, Ty, TypeFoldable};
 use std::marker::PhantomData;
 
 use super::const_evaluatable;
-use super::project;
+use super::project::{self, ProjectAndUnifyResult};
 use super::select::SelectionContext;
 use super::wf;
 use super::CodeAmbiguity;
@@ -753,8 +753,8 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
         }
 
         match project::poly_project_and_unify_type(self.selcx, &project_obligation) {
-            Ok(Ok(Some(os))) => ProcessResult::Changed(mk_pending(os)),
-            Ok(Ok(None)) => {
+            ProjectAndUnifyResult::Holds(os) => ProcessResult::Changed(mk_pending(os)),
+            ProjectAndUnifyResult::FailedNormalization => {
                 stalled_on.clear();
                 stalled_on.extend(substs_infer_vars(
                     self.selcx,
@@ -763,10 +763,12 @@ impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
                 ProcessResult::Unchanged
             }
             // Let the caller handle the recursion
-            Ok(Err(project::InProgress)) => ProcessResult::Changed(mk_pending(vec![
+            ProjectAndUnifyResult::Recursive => ProcessResult::Changed(mk_pending(vec![
                 project_obligation.with(project_obligation.predicate.to_predicate(tcx)),
             ])),
-            Err(e) => ProcessResult::Error(CodeProjectionError(e)),
+            ProjectAndUnifyResult::MismatchedProjectionTypes(e) => {
+                ProcessResult::Error(CodeProjectionError(e))
+            }
         }
     }
 }