Auto merge of #94733 - nnethercote:fix-AdtDef-interning, r=fee1-dead

Improve `AdtDef` interning.

This commit makes `AdtDef` use `Interned`. Much of the commit is tedious
changes to introduce getter functions. The interesting changes are in
`compiler/rustc_middle/src/ty/adt.rs`.

r? `@fee1-dead`

compiler/rustc_const_eval/src/interpret/intern.rs

@@ -174,7 +174,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: CompileTimeMachine<'mir, 'tcx, const_eval::Memory
         }
 
         if let Some(def) = mplace.layout.ty.ty_adt_def() {
-            if Some(def.did) == self.ecx.tcx.lang_items().unsafe_cell_type() {
+            if Some(def.did()) == self.ecx.tcx.lang_items().unsafe_cell_type() {
                 // We are crossing over an `UnsafeCell`, we can mutate again. This means that
                 // References we encounter inside here are interned as pointing to mutable
                 // allocations.

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -73,7 +73,9 @@ crate fn eval_nullary_intrinsic<'tcx>(
         }
         sym::variant_count => match tp_ty.kind() {
             // Correctly handles non-monomorphic calls, so there is no need for ensure_monomorphic_enough.
-            ty::Adt(ref adt, _) => ConstValue::from_machine_usize(adt.variants.len() as u64, &tcx),
+            ty::Adt(ref adt, _) => {
+                ConstValue::from_machine_usize(adt.variants().len() as u64, &tcx)
+            }
             ty::Projection(_)
             | ty::Opaque(_, _)
             | ty::Param(_)

compiler/rustc_const_eval/src/interpret/intrinsics/type_name.rs

@@ -1,3 +1,4 @@
+use rustc_data_structures::intern::Interned;
 use rustc_hir::def_id::CrateNum;
 use rustc_hir::definitions::DisambiguatedDefPathData;
 use rustc_middle::mir::interpret::{Allocation, ConstAllocation};
@@ -56,7 +57,7 @@ impl<'tcx> Printer<'tcx> for AbsolutePathPrinter<'tcx> {
             }
 
             // Types with identity (print the module path).
-            ty::Adt(&ty::AdtDef { did: def_id, .. }, substs)
+            ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did: def_id, .. }, _)), substs)
             | ty::FnDef(def_id, substs)
             | ty::Opaque(def_id, substs)
             | ty::Projection(ty::ProjectionTy { item_def_id: def_id, substs })

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -759,7 +759,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                                 .ty
                                 .ty_adt_def()
                                 .expect("tagged layout for non adt")
-                                .variants
+                                .variants()
                                 .len();
                             assert!(usize::try_from(variant_index).unwrap() < variants_len);
                             VariantIdx::from_u32(variant_index)

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -267,7 +267,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
                 match layout.variants {
                     Variants::Single { index } => {
                         // Inside a variant
-                        PathElem::Field(def.variants[index].fields[field].name)
+                        PathElem::Field(def.variant(index).fields[field].name)
                     }
                     Variants::Multiple { .. } => bug!("we handled variants above"),
                 }
@@ -734,7 +734,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
         new_op: &OpTy<'tcx, M::PointerTag>,
     ) -> InterpResult<'tcx> {
         let name = match old_op.layout.ty.kind() {
-            ty::Adt(adt, _) => PathElem::Variant(adt.variants[variant_id].name),
+            ty::Adt(adt, _) => PathElem::Variant(adt.variant(variant_id).name),
             // Generators also have variants
             ty::Generator(..) => PathElem::GeneratorState(variant_id),
             _ => bug!("Unexpected type with variant: {:?}", old_op.layout.ty),
@@ -771,7 +771,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
         // Special check preventing `UnsafeCell` in the inner part of constants
         if let Some(def) = op.layout.ty.ty_adt_def() {
             if matches!(self.ctfe_mode, Some(CtfeValidationMode::Const { inner: true, .. }))
-                && Some(def.did) == self.ecx.tcx.lang_items().unsafe_cell_type()
+                && Some(def.did()) == self.ecx.tcx.lang_items().unsafe_cell_type()
             {
                 throw_validation_failure!(self.path, { "`UnsafeCell` in a `const`" });
             }