Add more SMIR internal impl and callback return value

In cases like Kani, we will invoke the rustc_internal run command
directly for now. It would be handly to be able to have a callback
that can return a value.

We also need extra methods to convert stable constructs into internal
ones, so we can break down the transition into finer grain commits.

compiler/rustc_smir/src/rustc_internal/internal.rs

@@ -6,11 +6,23 @@
 // Prefer importing stable_mir over internal rustc constructs to make this file more readable.
 use crate::rustc_smir::Tables;
 use rustc_middle::ty::{self as rustc_ty, Ty as InternalTy};
-use stable_mir::ty::{Const, GenericArgKind, GenericArgs, Region, Ty};
-use stable_mir::DefId;
+use rustc_span::Symbol;
+use stable_mir::mir::mono::{Instance, MonoItem, StaticDef};
+use stable_mir::ty::{
+    Binder, BoundRegionKind, BoundTyKind, BoundVariableKind, ClosureKind, Const, GenericArgKind,
+    GenericArgs, Region, TraitRef, Ty,
+};
+use stable_mir::{AllocId, CrateItem, DefId};
 
 use super::RustcInternal;
 
+impl<'tcx> RustcInternal<'tcx> for CrateItem {
+    type T = rustc_span::def_id::DefId;
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        self.0.internal(tables)
+    }
+}
+
 impl<'tcx> RustcInternal<'tcx> for DefId {
     type T = rustc_span::def_id::DefId;
     fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
@@ -38,8 +50,9 @@ impl<'tcx> RustcInternal<'tcx> for GenericArgKind {
 
 impl<'tcx> RustcInternal<'tcx> for Region {
     type T = rustc_ty::Region<'tcx>;
-    fn internal(&self, _tables: &mut Tables<'tcx>) -> Self::T {
-        todo!()
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        // Cannot recover region. Use erased instead.
+        tables.tcx.lifetimes.re_erased
     }
 }
 
@@ -65,3 +78,118 @@ impl<'tcx> RustcInternal<'tcx> for Const {
         tables.constants[self.id]
     }
 }
+
+impl<'tcx> RustcInternal<'tcx> for MonoItem {
+    type T = rustc_middle::mir::mono::MonoItem<'tcx>;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        use rustc_middle::mir::mono as rustc_mono;
+        match self {
+            MonoItem::Fn(instance) => rustc_mono::MonoItem::Fn(instance.internal(tables)),
+            MonoItem::Static(def) => rustc_mono::MonoItem::Static(def.internal(tables)),
+            MonoItem::GlobalAsm(_) => {
+                unimplemented!()
+            }
+        }
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for Instance {
+    type T = rustc_ty::Instance<'tcx>;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        tables.instances[self.def]
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for StaticDef {
+    type T = rustc_span::def_id::DefId;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        self.0.internal(tables)
+    }
+}
+
+#[allow(rustc::usage_of_qualified_ty)]
+impl<'tcx, T> RustcInternal<'tcx> for Binder<T>
+where
+    T: RustcInternal<'tcx>,
+    T::T: rustc_ty::TypeVisitable<rustc_ty::TyCtxt<'tcx>>,
+{
+    type T = rustc_ty::Binder<'tcx, T::T>;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        rustc_ty::Binder::bind_with_vars(
+            self.value.internal(tables),
+            tables.tcx.mk_bound_variable_kinds_from_iter(
+                self.bound_vars.iter().map(|bound| bound.internal(tables)),
+            ),
+        )
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for BoundVariableKind {
+    type T = rustc_ty::BoundVariableKind;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        match self {
+            BoundVariableKind::Ty(kind) => rustc_ty::BoundVariableKind::Ty(match kind {
+                BoundTyKind::Anon => rustc_ty::BoundTyKind::Anon,
+                BoundTyKind::Param(def, symbol) => {
+                    rustc_ty::BoundTyKind::Param(def.0.internal(tables), Symbol::intern(&symbol))
+                }
+            }),
+            BoundVariableKind::Region(kind) => rustc_ty::BoundVariableKind::Region(match kind {
+                BoundRegionKind::BrAnon => rustc_ty::BoundRegionKind::BrAnon,
+                BoundRegionKind::BrNamed(def, symbol) => rustc_ty::BoundRegionKind::BrNamed(
+                    def.0.internal(tables),
+                    Symbol::intern(&symbol),
+                ),
+                BoundRegionKind::BrEnv => rustc_ty::BoundRegionKind::BrEnv,
+            }),
+            BoundVariableKind::Const => rustc_ty::BoundVariableKind::Const,
+        }
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for TraitRef {
+    type T = rustc_ty::TraitRef<'tcx>;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        rustc_ty::TraitRef::new(
+            tables.tcx,
+            self.def_id.0.internal(tables),
+            self.args().internal(tables),
+        )
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for AllocId {
+    type T = rustc_middle::mir::interpret::AllocId;
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        tables.alloc_ids[*self]
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for ClosureKind {
+    type T = rustc_ty::ClosureKind;
+
+    fn internal(&self, _tables: &mut Tables<'tcx>) -> Self::T {
+        match self {
+            ClosureKind::Fn => rustc_ty::ClosureKind::Fn,
+            ClosureKind::FnMut => rustc_ty::ClosureKind::FnMut,
+            ClosureKind::FnOnce => rustc_ty::ClosureKind::FnOnce,
+        }
+    }
+}
+
+impl<'tcx, T> RustcInternal<'tcx> for &T
+where
+    T: RustcInternal<'tcx>,
+{
+    type T = T::T;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        (*self).internal(tables)
+    }
+}