Rollup of 20 pull requests

compiler/rustc_abi/src/lib.rs

@@ -1812,7 +1812,7 @@ where
         f.debug_struct("Layout")
             .field("size", size)
             .field("align", align)
-            .field("abi", backend_repr)
+            .field("backend_repr", backend_repr)
             .field("fields", fields)
             .field("largest_niche", largest_niche)
             .field("uninhabited", uninhabited)

compiler/rustc_ast_lowering/src/lib.rs

@@ -926,7 +926,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     if let Some(first_char) = constraint.ident.as_str().chars().next()
                         && first_char.is_ascii_lowercase()
                     {
-                        tracing::info!(?data, ?data.inputs);
                         let err = match (&data.inputs[..], &data.output) {
                             ([_, ..], FnRetTy::Default(_)) => {
                                 errors::BadReturnTypeNotation::Inputs { span: data.inputs_span }

compiler/rustc_ast_lowering/src/path.rs

@@ -268,7 +268,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 }
                 GenericArgs::Parenthesized(data) => match generic_args_mode {
                     GenericArgsMode::ReturnTypeNotation => {
-                        tracing::info!(?data, ?data.inputs);
                         let err = match (&data.inputs[..], &data.output) {
                             ([_, ..], FnRetTy::Default(_)) => {
                                 BadReturnTypeNotation::Inputs { span: data.inputs_span }

compiler/rustc_attr_parsing/src/parser.rs

@@ -473,6 +473,15 @@ impl<'a> MetaItemListParserContext<'a> {
         {
             self.inside_delimiters.next();
             return Some(MetaItemOrLitParser::Lit(lit));
+        } else if let Some(TokenTree::Delimited(.., Delimiter::Invisible(_), inner_tokens)) =
+            self.inside_delimiters.peek()
+        {
+            self.inside_delimiters.next();
+            return MetaItemListParserContext {
+                inside_delimiters: inner_tokens.iter().peekable(),
+                dcx: self.dcx,
+            }
+            .next();
         }
 
         // or a path.

compiler/rustc_data_structures/src/marker.rs

@@ -1,3 +1,5 @@
+use std::alloc::Allocator;
+
 #[rustc_on_unimplemented(message = "`{Self}` doesn't implement `DynSend`. \
             Add it to `rustc_data_structures::marker` or use `IntoDynSyncSend` if it's already `Send`")]
 // This is an auto trait for types which can be sent across threads if `sync::is_dyn_thread_safe()`
@@ -28,8 +30,8 @@ impls_dyn_send_neg!(
     [*const T where T: ?Sized]
     [*mut T where T: ?Sized]
     [std::ptr::NonNull<T> where T: ?Sized]
-    [std::rc::Rc<T> where T: ?Sized]
-    [std::rc::Weak<T> where T: ?Sized]
+    [std::rc::Rc<T, A> where T: ?Sized, A: Allocator]
+    [std::rc::Weak<T, A> where T: ?Sized, A: Allocator]
     [std::sync::MutexGuard<'_, T> where T: ?Sized]
     [std::sync::RwLockReadGuard<'_, T> where T: ?Sized]
     [std::sync::RwLockWriteGuard<'_, T> where T: ?Sized]
@@ -96,8 +98,8 @@ impls_dyn_sync_neg!(
     [std::cell::RefCell<T> where T: ?Sized]
     [std::cell::UnsafeCell<T> where T: ?Sized]
     [std::ptr::NonNull<T> where T: ?Sized]
-    [std::rc::Rc<T> where T: ?Sized]
-    [std::rc::Weak<T> where T: ?Sized]
+    [std::rc::Rc<T, A> where T: ?Sized, A: Allocator]
+    [std::rc::Weak<T, A> where T: ?Sized, A: Allocator]
     [std::cell::OnceCell<T> where T]
     [std::sync::mpsc::Receiver<T> where T]
     [std::sync::mpsc::Sender<T> where T]

compiler/rustc_error_codes/src/error_codes/E0804.md

@@ -0,0 +1,41 @@
+An auto trait cannot be added to the bounds of a `dyn Trait` type via
+a pointer cast.
+
+Erroneous code example:
+
+```rust,edition2021,compile_fail,E0804
+let ptr: *const dyn core::any::Any = &();
+_ = ptr as *const (dyn core::any::Any + Send);
+```
+
+Adding an auto trait can make the vtable invalid, potentially causing
+UB in safe code afterwards. For example:
+
+```rust,edition2021,no_run
+use core::{mem::transmute, ptr::NonNull};
+
+trait Trait {
+    fn f(&self)
+    where
+        Self: Send;
+}
+
+impl Trait for NonNull<()> {
+    fn f(&self) {
+        unreachable!()
+    }
+}
+
+fn main() {
+    let unsend: &dyn Trait = &NonNull::dangling();
+    let bad: &(dyn Trait + Send) = unsafe { transmute(unsend) };
+    // This crashes, since the vtable for `NonNull as dyn Trait` does
+    // not have an entry for `Trait::f`.
+    bad.f();
+}
+```
+
+To fix this error, you can use `transmute` rather than pointer casts,
+but you must ensure that the vtable is valid for the pointer's type
+before calling a method on the trait object or allowing other code to
+do so.

compiler/rustc_error_codes/src/lib.rs

@@ -547,6 +547,7 @@ E0800: 0800,
 E0801: 0801,
 E0802: 0802,
 E0803: 0803,
+E0804: 0804,
         );
     )
 }

compiler/rustc_errors/src/lib.rs

@@ -626,7 +626,6 @@ pub enum StashKey {
     MaybeFruTypo,
     CallAssocMethod,
     AssociatedTypeSuggestion,
-    MaybeForgetReturn,
     /// Query cycle detected, stashing in favor of a better error.
     Cycle,
     UndeterminedMacroResolution,

compiler/rustc_hir_analysis/messages.ftl

@@ -278,13 +278,6 @@ hir_analysis_invalid_union_field =
 hir_analysis_invalid_union_field_sugg =
     wrap the field type in `ManuallyDrop<...>`
 
-hir_analysis_invalid_unsafe_field =
-    field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be unsafe
-    .note = unsafe fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>`
-
-hir_analysis_invalid_unsafe_field_sugg =
-    wrap the field type in `ManuallyDrop<...>`
-
 hir_analysis_late_bound_const_in_apit = `impl Trait` can only mention const parameters from an fn or impl
     .label = const parameter declared here
 
@@ -620,6 +613,8 @@ hir_analysis_variances_of = {$variances}
 hir_analysis_where_clause_on_main = `main` function is not allowed to have a `where` clause
     .label = `main` cannot have a `where` clause
 
+hir_analysis_within_macro = due to this macro variable
+
 hir_analysis_wrong_number_of_generic_arguments_to_intrinsic =
     intrinsic has wrong number of {$descr} parameters: found {$found}, expected {$expected}
     .label = expected {$expected} {$descr} {$expected ->