Rollup of 11 pull requests

Cargo.lock

@@ -556,7 +556,7 @@ checksum = "2da6da31387c7e4ef160ffab6d5e7f00c42626fe39aea70a7b0f1773f7dd6c1b"
 
 [[package]]
 name = "clippy"
-version = "0.1.77"
+version = "0.1.78"
 dependencies = [
  "anstream",
  "clippy_config",
@@ -584,7 +584,7 @@ dependencies = [
 
 [[package]]
 name = "clippy_config"
-version = "0.1.77"
+version = "0.1.78"
 dependencies = [
  "rustc-semver",
  "serde",
@@ -607,7 +607,7 @@ dependencies = [
 
 [[package]]
 name = "clippy_lints"
-version = "0.1.77"
+version = "0.1.78"
 dependencies = [
  "arrayvec",
  "cargo_metadata 0.18.0",
@@ -632,7 +632,7 @@ dependencies = [
 
 [[package]]
 name = "clippy_utils"
-version = "0.1.77"
+version = "0.1.78"
 dependencies = [
  "arrayvec",
  "clippy_config",
@@ -1003,7 +1003,7 @@ checksum = "a0afaad2b26fa326569eb264b1363e8ae3357618c43982b3f285f0774ce76b69"
 
 [[package]]
 name = "declare_clippy_lint"
-version = "0.1.77"
+version = "0.1.78"
 dependencies = [
  "itertools",
  "quote",

RELEASES.md

@@ -7,7 +7,6 @@ Language
 --------
 - [Document Rust ABI compatibility between various types](https://github.com/rust-lang/rust/pull/115476/)
 - [Also: guarantee that char and u32 are ABI-compatible](https://github.com/rust-lang/rust/pull/118032/)
-- [Warn against ambiguous wide pointer comparisons](https://github.com/rust-lang/rust/pull/117758/)
 - [Add lint `ambiguous_wide_pointer_comparisons` that supersedes `clippy::vtable_address_comparisons`](https://github.com/rust-lang/rust/pull/117758)
 
 <a id="1.76.0-Compiler"></a>

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -461,6 +461,7 @@ pub fn type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) -> &'ll D
         }
         ty::FnDef(..) | ty::FnPtr(_) => build_subroutine_type_di_node(cx, unique_type_id),
         ty::Closure(..) => build_closure_env_di_node(cx, unique_type_id),
+        ty::CoroutineClosure(..) => build_closure_env_di_node(cx, unique_type_id),
         ty::Coroutine(..) => enums::build_coroutine_di_node(cx, unique_type_id),
         ty::Adt(def, ..) => match def.adt_kind() {
             AdtKind::Struct => build_struct_type_di_node(cx, unique_type_id),
@@ -1068,6 +1069,7 @@ fn build_upvar_field_di_nodes<'ll, 'tcx>(
     let (&def_id, up_var_tys) = match closure_or_coroutine_ty.kind() {
         ty::Coroutine(def_id, args) => (def_id, args.as_coroutine().prefix_tys()),
         ty::Closure(def_id, args) => (def_id, args.as_closure().upvar_tys()),
+        ty::CoroutineClosure(def_id, args) => (def_id, args.as_coroutine_closure().upvar_tys()),
         _ => {
             bug!(
                 "build_upvar_field_di_nodes() called with non-closure-or-coroutine-type: {:?}",
@@ -1153,7 +1155,8 @@ fn build_closure_env_di_node<'ll, 'tcx>(
     unique_type_id: UniqueTypeId<'tcx>,
 ) -> DINodeCreationResult<'ll> {
     let closure_env_type = unique_type_id.expect_ty();
-    let &ty::Closure(def_id, _args) = closure_env_type.kind() else {
+    let &(ty::Closure(def_id, _) | ty::CoroutineClosure(def_id, _)) = closure_env_type.kind()
+    else {
         bug!("build_closure_env_di_node() called with non-closure-type: {:?}", closure_env_type)
     };
     let containing_scope = get_namespace_for_item(cx, def_id);

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -1985,10 +1985,9 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
 
         match in_elem.kind() {
             ty::RawPtr(p) => {
-                let (metadata, check_sized) = p.ty.ptr_metadata_ty(bx.tcx, |ty| {
+                let metadata = p.ty.ptr_metadata_ty(bx.tcx, |ty| {
                     bx.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), ty)
                 });
-                assert!(!check_sized); // we are in codegen, so we shouldn't see these types
                 require!(
                     metadata.is_unit(),
                     InvalidMonomorphization::CastFatPointer { span, name, ty: in_elem }
@@ -2000,10 +1999,9 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
         }
         match out_elem.kind() {
             ty::RawPtr(p) => {
-                let (metadata, check_sized) = p.ty.ptr_metadata_ty(bx.tcx, |ty| {
+                let metadata = p.ty.ptr_metadata_ty(bx.tcx, |ty| {
                     bx.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), ty)
                 });
-                assert!(!check_sized); // we are in codegen, so we shouldn't see these types
                 require!(
                     metadata.is_unit(),
                     InvalidMonomorphization::CastFatPointer { span, name, ty: out_elem }

compiler/rustc_const_eval/src/interpret/terminator.rs

@@ -377,12 +377,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 // to fields, which can yield non-normalized types. So we need to provide a
                 // normalization function.
                 let normalize = |ty| self.tcx.normalize_erasing_regions(self.param_env, ty);
-                let (meta, only_if_sized) = ty.ptr_metadata_ty(*self.tcx, normalize);
-                assert!(
-                    !only_if_sized,
-                    "there should be no more 'maybe has that metadata' types during interpretation"
-                );
-                meta
+                ty.ptr_metadata_ty(*self.tcx, normalize)
             };
             return Ok(meta_ty(caller) == meta_ty(callee));
         }

compiler/rustc_hir_typeck/src/cast.rs

@@ -448,13 +448,35 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                             );
                         }
                     }
-                    let msg = "an `as` expression can only be used to convert between primitive \
-                               types or to coerce to a specific trait object";
+
+                    let (msg, note) = if let ty::Adt(adt, _) = self.expr_ty.kind()
+                        && adt.is_enum()
+                        && self.cast_ty.is_numeric()
+                    {
+                        (
+                            "an `as` expression can be used to convert enum types to numeric \
+                             types only if the enum type is unit-only or field-less",
+                            Some(
+                                "see https://doc.rust-lang.org/reference/items/enumerations.html#casting for more information",
+                            ),
+                        )
+                    } else {
+                        (
+                            "an `as` expression can only be used to convert between primitive \
+                             types or to coerce to a specific trait object",
+                            None,
+                        )
+                    };
+
                     if label {
                         err.span_label(self.span, msg);
                     } else {
                         err.note(msg);
                     }
+
+                    if let Some(note) = note {
+                        err.note(note);
+                    }
                 } else {
                     err.span_label(self.span, "invalid cast");
                 }

compiler/rustc_middle/src/ty/sty.rs

@@ -2279,12 +2279,12 @@ impl<'tcx> Ty<'tcx> {
     }
 
     /// Returns the type of metadata for (potentially fat) pointers to this type,
-    /// and a boolean signifying if this is conditional on this type being `Sized`.
-    pub fn ptr_metadata_ty(
+    /// or the struct tail if the metadata type cannot be determined.
+    pub fn ptr_metadata_ty_or_tail(
         self,
         tcx: TyCtxt<'tcx>,
         normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>,
-    ) -> (Ty<'tcx>, bool) {
+    ) -> Result<Ty<'tcx>, Ty<'tcx>> {
         let tail = tcx.struct_tail_with_normalize(self, normalize, || {});
         match tail.kind() {
             // Sized types
@@ -2307,31 +2307,47 @@ impl<'tcx> Ty<'tcx> {
             | ty::Error(_)
             // Extern types have metadata = ().
             | ty::Foreign(..)
-            // `dyn*` has no metadata
+            // `dyn*` has metadata = ().
             | ty::Dynamic(_, _, ty::DynStar)
-            // If returned by `struct_tail_without_normalization` this is a unit struct
+            // If returned by `struct_tail_with_normalize` this is a unit struct
             // without any fields, or not a struct, and therefore is Sized.
             | ty::Adt(..)
-            // If returned by `struct_tail_without_normalization` this is the empty tuple,
+            // If returned by `struct_tail_with_normalize` this is the empty tuple,
             // a.k.a. unit type, which is Sized
-            | ty::Tuple(..) => (tcx.types.unit, false),
+            | ty::Tuple(..) => Ok(tcx.types.unit),
+
+            ty::Str | ty::Slice(_) => Ok(tcx.types.usize),
 
-            ty::Str | ty::Slice(_) => (tcx.types.usize, false),
             ty::Dynamic(_, _, ty::Dyn) => {
                 let dyn_metadata = tcx.require_lang_item(LangItem::DynMetadata, None);
-                (tcx.type_of(dyn_metadata).instantiate(tcx, &[tail.into()]), false)
-            },
+                Ok(tcx.type_of(dyn_metadata).instantiate(tcx, &[tail.into()]))
+            }
 
-            // type parameters only have unit metadata if they're sized, so return true
-            // to make sure we double check this during confirmation
-            ty::Param(_) |  ty::Alias(..) => (tcx.types.unit, true),
+            // We don't know the metadata of `self`, but it must be equal to the
+            // metadata of `tail`.
+            ty::Param(_) | ty::Alias(..) => Err(tail),
 
             ty::Infer(ty::TyVar(_))
             | ty::Bound(..)
             | ty::Placeholder(..)
-            | ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => {
-                bug!("`ptr_metadata_ty` applied to unexpected type: {:?} (tail = {:?})", self, tail)
-            }
+            | ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => bug!(
+                "`ptr_metadata_ty_or_tail` applied to unexpected type: {self:?} (tail = {tail:?})"
+            ),
+        }
+    }
+
+    /// Returns the type of metadata for (potentially fat) pointers to this type.
+    /// Causes an ICE if the metadata type cannot be determined.
+    pub fn ptr_metadata_ty(
+        self,
+        tcx: TyCtxt<'tcx>,
+        normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>,
+    ) -> Ty<'tcx> {
+        match self.ptr_metadata_ty_or_tail(tcx, normalize) {
+            Ok(metadata) => metadata,
+            Err(tail) => bug!(
+                "`ptr_metadata_ty` failed to get metadata for type: {self:?} (tail = {tail:?})"
+            ),
         }
     }