Rollup merge of #74399 - mark-i-m:ty-err-4, r=eddyb

Move DelaySpanBugEmitted to ty::context

This makes it even hard to abuse.

r? @eddyb

cc @LeSeulArtichaut as this will probably conflict with your PR :/

src/librustc_middle/ty/consts/kind.rs

@@ -34,7 +34,7 @@ pub enum ConstKind<'tcx> {
 
     /// A placeholder for a const which could not be computed; this is
     /// propagated to avoid useless error messages.
-    Error(ty::sty::DelaySpanBugEmitted),
+    Error(ty::DelaySpanBugEmitted),
 }
 
 #[cfg(target_arch = "x86_64")]

src/librustc_middle/ty/context.rs

@@ -65,6 +65,12 @@ use std::mem;
 use std::ops::{Bound, Deref};
 use std::sync::Arc;
 
+/// A type that is not publicly constructable. This prevents people from making `TyKind::Error`
+/// except through `tcx.err*()`, which are in this module.
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
+#[derive(TyEncodable, TyDecodable, HashStable)]
+pub struct DelaySpanBugEmitted(());
+
 type InternedSet<'tcx, T> = ShardedHashMap<Interned<'tcx, T>, ()>;
 
 pub struct CtxtInterners<'tcx> {
@@ -1171,18 +1177,15 @@ impl<'tcx> TyCtxt<'tcx> {
     #[track_caller]
     pub fn ty_error_with_message<S: Into<MultiSpan>>(self, span: S, msg: &str) -> Ty<'tcx> {
         self.sess.delay_span_bug(span, msg);
-        self.mk_ty(Error(super::sty::DelaySpanBugEmitted(())))
+        self.mk_ty(Error(DelaySpanBugEmitted(())))
     }
 
     /// Like `err` but for constants.
     #[track_caller]
     pub fn const_error(self, ty: Ty<'tcx>) -> &'tcx Const<'tcx> {
         self.sess
             .delay_span_bug(DUMMY_SP, "ty::ConstKind::Error constructed but no error reported.");
-        self.mk_const(ty::Const {
-            val: ty::ConstKind::Error(super::sty::DelaySpanBugEmitted(())),
-            ty,
-        })
+        self.mk_const(ty::Const { val: ty::ConstKind::Error(DelaySpanBugEmitted(())), ty })
     }
 
     pub fn consider_optimizing<T: Fn() -> String>(&self, msg: T) -> bool {

src/librustc_middle/ty/mod.rs

@@ -73,8 +73,8 @@ pub use self::binding::BindingMode::*;
 
 pub use self::context::{tls, FreeRegionInfo, TyCtxt};
 pub use self::context::{
-    CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, ResolvedOpaqueTy,
-    UserType, UserTypeAnnotationIndex,
+    CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations,
+    DelaySpanBugEmitted, ResolvedOpaqueTy, UserType, UserTypeAnnotationIndex,
 };
 pub use self::context::{
     CtxtInterners, GeneratorInteriorTypeCause, GlobalCtxt, Lift, TypeckResults,

src/librustc_middle/ty/sty.rs

@@ -10,7 +10,7 @@ use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef};
 use crate::ty::{
     self, AdtDef, DefIdTree, Discr, Ty, TyCtxt, TypeFlags, TypeFoldable, WithConstness,
 };
-use crate::ty::{List, ParamEnv, TyS};
+use crate::ty::{DelaySpanBugEmitted, List, ParamEnv, TyS};
 use polonius_engine::Atom;
 use rustc_ast::ast;
 use rustc_data_structures::captures::Captures;
@@ -212,12 +212,6 @@ impl TyKind<'tcx> {
     }
 }
 
-/// A type that is not publicly constructable. This prevents people from making `TyKind::Error`
-/// except through `tcx.err*()`.
-#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
-#[derive(TyEncodable, TyDecodable, HashStable)]
-pub struct DelaySpanBugEmitted(pub(super) ());
-
 // `TyKind` is used a lot. Make sure it doesn't unintentionally get bigger.
 #[cfg(target_arch = "x86_64")]
 static_assert_size!(TyKind<'_>, 24);