Auto merge of #91093 - matthiaskrgr:rollup-kovzwx0, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #89741 (Mark `Arc::from_inner` / `Rc::from_inner` as unsafe)
 - #90927 (Fix float ICE)
 - #90994 (Fix ICE `#90993`: add missing call to cancel)
 - #91018 (Adopt let_else in more places in rustc_mir_build)
 - #91022 (Suggest `await` in more situations where infer types are involved)
 - #91088 (Revert "require full validity when determining the discriminant of a value")

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -265,12 +265,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             }
             sym::discriminant_value => {
                 let place = self.deref_operand(&args[0])?;
-                if M::enforce_validity(self) {
-                    // This is 'using' the value, so make sure the validity invariant is satisfied.
-                    // (Also see https://github.com/rust-lang/rust/pull/89764.)
-                    self.validate_operand(&place.into())?;
-                }
-
                 let discr_val = self.read_discriminant(&place.into())?.0;
                 self.write_scalar(discr_val, dest)?;
             }

compiler/rustc_const_eval/src/interpret/step.rs

@@ -304,12 +304,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
             Discriminant(place) => {
                 let op = self.eval_place_to_op(place, None)?;
-                if M::enforce_validity(self) {
-                    // This is 'using' the value, so make sure the validity invariant is satisfied.
-                    // (Also see https://github.com/rust-lang/rust/pull/89764.)
-                    self.validate_operand(&op)?;
-                }
-
                 let discr_val = self.read_discriminant(&op)?.0;
                 self.write_scalar(discr_val, &dest)?;
             }

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -310,6 +310,34 @@ pub fn unexpected_hidden_region_diagnostic(
     err
 }
 
+/// Structurally compares two types, modulo any inference variables.
+///
+/// Returns `true` if two types are equal, or if one type is an inference variable compatible
+/// with the other type. A TyVar inference type is compatible with any type, and an IntVar or
+/// FloatVar inference type are compatible with themselves or their concrete types (Int and
+/// Float types, respectively). When comparing two ADTs, these rules apply recursively.
+pub fn same_type_modulo_infer(a: Ty<'tcx>, b: Ty<'ctx>) -> bool {
+    match (&a.kind(), &b.kind()) {
+        (&ty::Adt(did_a, substs_a), &ty::Adt(did_b, substs_b)) => {
+            if did_a != did_b {
+                return false;
+            }
+
+            substs_a.types().zip(substs_b.types()).all(|(a, b)| same_type_modulo_infer(a, b))
+        }
+        (&ty::Int(_), &ty::Infer(ty::InferTy::IntVar(_)))
+        | (&ty::Infer(ty::InferTy::IntVar(_)), &ty::Int(_) | &ty::Infer(ty::InferTy::IntVar(_)))
+        | (&ty::Float(_), &ty::Infer(ty::InferTy::FloatVar(_)))
+        | (
+            &ty::Infer(ty::InferTy::FloatVar(_)),
+            &ty::Float(_) | &ty::Infer(ty::InferTy::FloatVar(_)),
+        )
+        | (&ty::Infer(ty::InferTy::TyVar(_)), _)
+        | (_, &ty::Infer(ty::InferTy::TyVar(_))) => true,
+        _ => a == b,
+    }
+}
+
 impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     pub fn report_region_errors(&self, errors: &Vec<RegionResolutionError<'tcx>>) {
         debug!("report_region_errors(): {} errors to start", errors.len());
@@ -1761,7 +1789,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             self.get_impl_future_output_ty(exp_found.expected),
             self.get_impl_future_output_ty(exp_found.found),
         ) {
-            (Some(exp), Some(found)) if ty::TyS::same_type(exp, found) => match &cause.code {
+            (Some(exp), Some(found)) if same_type_modulo_infer(exp, found) => match &cause.code {
                 ObligationCauseCode::IfExpression(box IfExpressionCause { then, .. }) => {
                     diag.multipart_suggestion(
                         "consider `await`ing on both `Future`s",
@@ -1793,7 +1821,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     diag.help("consider `await`ing on both `Future`s");
                 }
             },
-            (_, Some(ty)) if ty::TyS::same_type(exp_found.expected, ty) => {
+            (_, Some(ty)) if same_type_modulo_infer(exp_found.expected, ty) => {
                 diag.span_suggestion_verbose(
                     exp_span.shrink_to_hi(),
                     "consider `await`ing on the `Future`",
@@ -1801,7 +1829,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     Applicability::MaybeIncorrect,
                 );
             }
-            (Some(ty), _) if ty::TyS::same_type(ty, exp_found.found) => match cause.code {
+            (Some(ty), _) if same_type_modulo_infer(ty, exp_found.found) => match cause.code {
                 ObligationCauseCode::Pattern { span: Some(span), .. }
                 | ObligationCauseCode::IfExpression(box IfExpressionCause { then: span, .. }) => {
                     diag.span_suggestion_verbose(

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -1606,13 +1606,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         // encounter a candidate where the test is not relevant; at
         // that point, we stop sorting.
         while let Some(candidate) = candidates.first_mut() {
-            if let Some(idx) = self.sort_candidate(&match_place.clone(), &test, candidate) {
+            let Some(idx) = self.sort_candidate(&match_place.clone(), &test, candidate) else {
+                break;
+            };
             let (candidate, rest) = candidates.split_first_mut().unwrap();
             target_candidates[idx].push(candidate);
             candidates = rest;
-            } else {
-                break;
-            }
         }
         // at least the first candidate ought to be tested
         assert!(total_candidate_count > candidates.len());

compiler/rustc_mir_build/src/build/mod.rs

@@ -966,7 +966,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 DropKind::Value,
             );
 
-            if let Some(arg) = arg_opt {
+            let Some(arg) = arg_opt else {
+                continue;
+            };
             let pat = match tcx.hir().get(arg.pat.hir_id) {
                 Node::Pat(pat) | Node::Binding(pat) => pat,
                 node => bug!("pattern became {:?}", node),
@@ -1012,14 +1014,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         Some((Some(&place), span)),
                     );
                     let place_builder = PlaceBuilder::from(local);
-                        unpack!(
-                            block = self.place_into_pattern(block, pattern, place_builder, false)
-                        );
+                    unpack!(block = self.place_into_pattern(block, pattern, place_builder, false));
                 }
             }
             self.source_scope = original_source_scope;
         }
-        }
 
         // Enter the argument pattern bindings source scope, if it exists.
         if let Some(source_scope) = scope {

compiler/rustc_mir_build/src/check_unsafety.rs

@@ -256,7 +256,13 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
             }
             PatKind::Binding { mode: BindingMode::ByRef(borrow_kind), ty, .. } => {
                 if self.inside_adt {
-                    if let ty::Ref(_, ty, _) = ty.kind() {
+                    let ty::Ref(_, ty, _) = ty.kind() else {
+                        span_bug!(
+                            pat.span,
+                            "BindingMode::ByRef in pattern, but found non-reference type {}",
+                            ty
+                        );
+                    };
                     match borrow_kind {
                         BorrowKind::Shallow | BorrowKind::Shared | BorrowKind::Unique => {
                             if !ty.is_freeze(self.tcx.at(pat.span), self.param_env) {
@@ -267,13 +273,6 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
                             self.requires_unsafe(pat.span, MutationOfLayoutConstrainedField);
                         }
                     }
-                    } else {
-                        span_bug!(
-                            pat.span,
-                            "BindingMode::ByRef in pattern, but found non-reference type {}",
-                            ty
-                        );
-                    }
                 }
                 visit::walk_pat(self, pat);
             }

compiler/rustc_parse/src/parser/expr.rs

@@ -1032,6 +1032,8 @@ impl<'a> Parser<'a> {
             [IdentLike(_), Punct('+' | '-')] |
             // 1e+2 | 1e-2
             [IdentLike(_), Punct('+' | '-'), IdentLike(_)] |
+            // 1.2e+ | 1.2e-
+            [IdentLike(_), Punct('.'), IdentLike(_), Punct('+' | '-')] |
             // 1.2e+3 | 1.2e-3
             [IdentLike(_), Punct('.'), IdentLike(_), Punct('+' | '-'), IdentLike(_)] => {
                 // See the FIXME about `TokenCursor` above.

compiler/rustc_parse/src/parser/pat.rs

@@ -817,7 +817,7 @@ impl<'a> Parser<'a> {
             // Ensure the user doesn't receive unhelpful unexpected token errors
             self.bump();
             if self.is_pat_range_end_start(0) {
-                let _ = self.parse_pat_range_end();
+                let _ = self.parse_pat_range_end().map_err(|mut e| e.cancel());
             }
 
             self.error_inclusive_range_with_extra_equals(span_with_eq);

library/alloc/src/rc.rs

@@ -341,12 +341,12 @@ impl<T: ?Sized> Rc<T> {
         unsafe { self.ptr.as_ref() }
     }
 
-    fn from_inner(ptr: NonNull<RcBox<T>>) -> Self {
+    unsafe fn from_inner(ptr: NonNull<RcBox<T>>) -> Self {
         Self { ptr, phantom: PhantomData }
     }
 
     unsafe fn from_ptr(ptr: *mut RcBox<T>) -> Self {
-        Self::from_inner(unsafe { NonNull::new_unchecked(ptr) })
+        unsafe { Self::from_inner(NonNull::new_unchecked(ptr)) }
     }
 }
 
@@ -367,10 +367,12 @@ impl<T> Rc<T> {
         // pointers, which ensures that the weak destructor never frees
         // the allocation while the strong destructor is running, even
         // if the weak pointer is stored inside the strong one.
+        unsafe {
             Self::from_inner(
                 Box::leak(box RcBox { strong: Cell::new(1), weak: Cell::new(1), value }).into(),
             )
         }
+    }
 
     /// Constructs a new `Rc<T>` using a weak reference to itself. Attempting
     /// to upgrade the weak reference before this function returns will result
@@ -420,16 +422,16 @@ impl<T> Rc<T> {
         // otherwise.
         let data = data_fn(&weak);
 
-        unsafe {
+        let strong = unsafe {
             let inner = init_ptr.as_ptr();
             ptr::write(ptr::addr_of_mut!((*inner).value), data);
 
             let prev_value = (*inner).strong.get();
             debug_assert_eq!(prev_value, 0, "No prior strong references should exist");
             (*inner).strong.set(1);
-        }
 
-        let strong = Rc::from_inner(init_ptr);
+            Rc::from_inner(init_ptr)
+        };
 
         // Strong references should collectively own a shared weak reference,
         // so don't run the destructor for our old weak reference.
@@ -521,11 +523,13 @@ impl<T> Rc<T> {
         // pointers, which ensures that the weak destructor never frees
         // the allocation while the strong destructor is running, even
         // if the weak pointer is stored inside the strong one.
+        unsafe {
             Ok(Self::from_inner(
                 Box::leak(Box::try_new(RcBox { strong: Cell::new(1), weak: Cell::new(1), value })?)
                     .into(),
             ))
         }
+    }
 
     /// Constructs a new `Rc` with uninitialized contents, returning an error if the allocation fails
     ///
@@ -746,7 +750,7 @@ impl<T> Rc<mem::MaybeUninit<T>> {
     #[unstable(feature = "new_uninit", issue = "63291")]
     #[inline]
     pub unsafe fn assume_init(self) -> Rc<T> {
-        Rc::from_inner(mem::ManuallyDrop::new(self).ptr.cast())
+        unsafe { Rc::from_inner(mem::ManuallyDrop::new(self).ptr.cast()) }
     }
 }
 
@@ -1214,9 +1218,11 @@ impl Rc<dyn Any> {
     /// ```
     pub fn downcast<T: Any>(self) -> Result<Rc<T>, Rc<dyn Any>> {
         if (*self).is::<T>() {
+            unsafe {
                 let ptr = self.ptr.cast::<RcBox<T>>();
                 forget(self);
                 Ok(Rc::from_inner(ptr))
+            }
         } else {
             Err(self)
         }
@@ -1489,10 +1495,12 @@ impl<T: ?Sized> Clone for Rc<T> {
     /// ```
     #[inline]
     fn clone(&self) -> Rc<T> {
+        unsafe {
             self.inner().inc_strong();
             Self::from_inner(self.ptr)
         }
     }
+}
 
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -2245,13 +2253,16 @@ impl<T: ?Sized> Weak<T> {
     #[stable(feature = "rc_weak", since = "1.4.0")]
     pub fn upgrade(&self) -> Option<Rc<T>> {
         let inner = self.inner()?;
+
         if inner.strong() == 0 {
             None
         } else {
+            unsafe {
                 inner.inc_strong();
                 Some(Rc::from_inner(self.ptr))
             }
         }
+    }
 
     /// Gets the number of strong (`Rc`) pointers pointing to this allocation.
     ///

library/alloc/src/sync.rs

@@ -252,7 +252,7 @@ impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<Arc<U>> for Arc<T> {}
 impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Arc<U>> for Arc<T> {}
 
 impl<T: ?Sized> Arc<T> {
-    fn from_inner(ptr: NonNull<ArcInner<T>>) -> Self {
+    unsafe fn from_inner(ptr: NonNull<ArcInner<T>>) -> Self {
         Self { ptr, phantom: PhantomData }
     }
 
@@ -348,7 +348,7 @@ impl<T> Arc<T> {
             weak: atomic::AtomicUsize::new(1),
             data,
         };
-        Self::from_inner(Box::leak(x).into())
+        unsafe { Self::from_inner(Box::leak(x).into()) }
     }
 
     /// Constructs a new `Arc<T>` using a weak reference to itself. Attempting
@@ -397,7 +397,7 @@ impl<T> Arc<T> {
 
         // Now we can properly initialize the inner value and turn our weak
         // reference into a strong reference.
-        unsafe {
+        let strong = unsafe {
             let inner = init_ptr.as_ptr();
             ptr::write(ptr::addr_of_mut!((*inner).data), data);
 
@@ -415,9 +415,9 @@ impl<T> Arc<T> {
             // possible with safe code alone.
             let prev_value = (*inner).strong.fetch_add(1, Release);
             debug_assert_eq!(prev_value, 0, "No prior strong references should exist");
-        }
 
-        let strong = Arc::from_inner(init_ptr);
+            Arc::from_inner(init_ptr)
+        };
 
         // Strong references should collectively own a shared weak reference,
         // so don't run the destructor for our old weak reference.
@@ -529,7 +529,7 @@ impl<T> Arc<T> {
             weak: atomic::AtomicUsize::new(1),
             data,
         })?;
-        Ok(Self::from_inner(Box::leak(x).into()))
+        unsafe { Ok(Self::from_inner(Box::leak(x).into())) }
     }
 
     /// Constructs a new `Arc` with uninitialized contents, returning an error
@@ -743,7 +743,7 @@ impl<T> Arc<mem::MaybeUninit<T>> {
     #[must_use = "`self` will be dropped if the result is not used"]
     #[inline]
     pub unsafe fn assume_init(self) -> Arc<T> {
-        Arc::from_inner(mem::ManuallyDrop::new(self).ptr.cast())
+        unsafe { Arc::from_inner(mem::ManuallyDrop::new(self).ptr.cast()) }
     }
 }
 
@@ -1341,7 +1341,7 @@ impl<T: ?Sized> Clone for Arc<T> {
             abort();
         }
 
-        Self::from_inner(self.ptr)
+        unsafe { Self::from_inner(self.ptr) }
     }
 }
 
@@ -1668,9 +1668,11 @@ impl Arc<dyn Any + Send + Sync> {
         T: Any + Send + Sync + 'static,
     {
         if (*self).is::<T>() {
+            unsafe {
                 let ptr = self.ptr.cast::<ArcInner<T>>();
                 mem::forget(self);
                 Ok(Arc::from_inner(ptr))
+            }
         } else {
             Err(self)
         }
@@ -1899,7 +1901,7 @@ impl<T: ?Sized> Weak<T> {
             // value can be initialized after `Weak` references have already been created. In that case, we
             // expect to observe the fully initialized value.
             match inner.strong.compare_exchange_weak(n, n + 1, Acquire, Relaxed) {
-                Ok(_) => return Some(Arc::from_inner(self.ptr)), // null checked above
+                Ok(_) => return Some(unsafe { Arc::from_inner(self.ptr) }), // null checked above
                 Err(old) => n = old,
             }
         }

src/test/ui/async-await/suggest-missing-await.rs

@@ -54,4 +54,21 @@ async fn suggest_await_on_match_expr() {
     };
 }
 
+async fn dummy_result() -> Result<(), ()> {
+    Ok(())
+}
+
+#[allow(unused)]
+async fn suggest_await_in_generic_pattern() {
+    match dummy_result() {
+        //~^ HELP consider `await`ing on the `Future`
+        //~| HELP consider `await`ing on the `Future`
+        //~| SUGGESTION .await
+        Ok(_) => {}
+        //~^ ERROR mismatched types [E0308]
+        Err(_) => {}
+        //~^ ERROR mismatched types [E0308]
+    }
+}
+
 fn main() {}

src/test/ui/async-await/suggest-missing-await.stderr

@@ -106,6 +106,42 @@ help: consider `await`ing on the `Future`
 LL |     let _x = match dummy().await {
    |                           ++++++
 
-error: aborting due to 5 previous errors
+error[E0308]: mismatched types
+  --> $DIR/suggest-missing-await.rs:67:9
+   |
+LL |         Ok(_) => {}
+   |         ^^^^^ expected opaque type, found enum `Result`
+   |
+note: while checking the return type of the `async fn`
+  --> $DIR/suggest-missing-await.rs:57:28
+   |
+LL | async fn dummy_result() -> Result<(), ()> {
+   |                            ^^^^^^^^^^^^^^ checked the `Output` of this `async fn`, expected opaque type
+   = note: expected opaque type `impl Future<Output = Result<(), ()>>`
+                     found enum `Result<_, _>`
+help: consider `await`ing on the `Future`
+   |
+LL |     match dummy_result().await {
+   |                         ++++++
+
+error[E0308]: mismatched types
+  --> $DIR/suggest-missing-await.rs:69:9
+   |
+LL |         Err(_) => {}
+   |         ^^^^^^ expected opaque type, found enum `Result`
+   |
+note: while checking the return type of the `async fn`
+  --> $DIR/suggest-missing-await.rs:57:28
+   |
+LL | async fn dummy_result() -> Result<(), ()> {
+   |                            ^^^^^^^^^^^^^^ checked the `Output` of this `async fn`, expected opaque type
+   = note: expected opaque type `impl Future<Output = Result<(), ()>>`
+                     found enum `Result<_, _>`
+help: consider `await`ing on the `Future`
+   |
+LL |     match dummy_result().await {
+   |                         ++++++
+
+error: aborting due to 7 previous errors
 
 For more information about this error, try `rustc --explain E0308`.

src/test/ui/parser/issue-90728.rs

@@ -0,0 +1,6 @@
+fn main() {
+    a.5.2E+
+    //~^ ERROR: unexpected token: `5.2E+`
+    //~| ERROR: expected one of `.`, `;`, `?`, `}`, or an operator, found `5.2E+`
+    //~| ERROR: expected at least one digit in exponent
+}

src/test/ui/parser/issue-90728.stderr

@@ -0,0 +1,20 @@
+error: expected at least one digit in exponent
+  --> $DIR/issue-90728.rs:2:7
+   |
+LL |     a.5.2E+
+   |       ^^^^^
+
+error: unexpected token: `5.2E+`
+  --> $DIR/issue-90728.rs:2:7
+   |
+LL |     a.5.2E+
+   |       ^^^^^
+
+error: expected one of `.`, `;`, `?`, `}`, or an operator, found `5.2E+`
+  --> $DIR/issue-90728.rs:2:7
+   |
+LL |     a.5.2E+
+   |       ^^^^^ expected one of `.`, `;`, `?`, `}`, or an operator
+
+error: aborting due to 3 previous errors
+