Handle generic Slices and Arrays

Slices and Arrays are covariant types which means they can contain elements
which bind generics such as ADT or FnTypes. This means substitutions can be
recursive and this gives the typechecker a chance to handle this recursion
on these types.

3 files changed, 46 insertions, 2 deletions

diff --git a/gcc/rust/typecheck/rust-substitution-mapper.h b/gcc/rust/typecheck/rust-substitution-mapper.h
index 0d48bd2..5f17816 100644
--- a/gcc/rust/typecheck/rust-substitution-mapper.h
+++ b/gcc/rust/typecheck/rust-substitution-mapper.h
@@ -221,11 +221,19 @@ public:
     resolved = type.handle_substitions (mappings);
   }
 
+  void visit (TyTy::ArrayType &type) override
+  {
+    resolved = type.handle_substitions (mappings);
+  }
+
+  void visit (TyTy::SliceType &type) override
+  {
+    resolved = type.handle_substitions (mappings);
+  }
+
   // nothing to do for these
   void visit (TyTy::InferType &) override { gcc_unreachable (); }
   void visit (TyTy::FnPtr &) override { gcc_unreachable (); }
-  void visit (TyTy::ArrayType &) override { gcc_unreachable (); }
-  void visit (TyTy::SliceType &) override { gcc_unreachable (); }
   void visit (TyTy::BoolType &) override { gcc_unreachable (); }
   void visit (TyTy::IntType &) override { gcc_unreachable (); }
   void visit (TyTy::UintType &) override { gcc_unreachable (); }
diff --git a/gcc/rust/typecheck/rust-tyty.cc b/gcc/rust/typecheck/rust-tyty.cc
index 0a29644..8d5cc5e 100644
--- a/gcc/rust/typecheck/rust-tyty.cc
+++ b/gcc/rust/typecheck/rust-tyty.cc
@@ -1508,6 +1508,22 @@ ArrayType::clone () const
 			element_type, get_combined_refs ());
 }
 
+ArrayType *
+ArrayType::handle_substitions (SubstitutionArgumentMappings mappings)
+{
+  auto mappings_table = Analysis::Mappings::get ();
+
+  ArrayType *ref = static_cast<ArrayType *> (clone ());
+  ref->set_ty_ref (mappings_table->get_next_hir_id ());
+
+  // might be &T or &ADT so this needs to be recursive
+  auto base = ref->get_element_type ();
+  BaseType *concrete = Resolver::SubstMapperInternal::Resolve (base, mappings);
+  ref->element_type = TyVar (concrete->get_ty_ref ());
+
+  return ref;
+}
+
 void
 SliceType::accept_vis (TyVisitor &vis)
 {
@@ -1581,6 +1597,22 @@ SliceType::clone () const
 			get_combined_refs ());
 }
 
+SliceType *
+SliceType::handle_substitions (SubstitutionArgumentMappings mappings)
+{
+  auto mappings_table = Analysis::Mappings::get ();
+
+  SliceType *ref = static_cast<SliceType *> (clone ());
+  ref->set_ty_ref (mappings_table->get_next_hir_id ());
+
+  // might be &T or &ADT so this needs to be recursive
+  auto base = ref->get_element_type ();
+  BaseType *concrete = Resolver::SubstMapperInternal::Resolve (base, mappings);
+  ref->element_type = TyVar (concrete->get_ty_ref ());
+
+  return ref;
+}
+
 void
 BoolType::accept_vis (TyVisitor &vis)
 {
diff --git a/gcc/rust/typecheck/rust-tyty.h b/gcc/rust/typecheck/rust-tyty.h
index bf4110b..82262ab 100644
--- a/gcc/rust/typecheck/rust-tyty.h
+++ b/gcc/rust/typecheck/rust-tyty.h
@@ -1665,6 +1665,8 @@ public:
 
   HIR::Expr &get_capacity_expr () const { return capacity_expr; }
 
+  ArrayType *handle_substitions (SubstitutionArgumentMappings mappings);
+
 private:
   TyVar element_type;
   HIR::Expr &capacity_expr;
@@ -1710,6 +1712,8 @@ public:
     return get_element_type ()->is_concrete ();
   }
 
+  SliceType *handle_substitions (SubstitutionArgumentMappings mappings);
+
 private:
   TyVar element_type;
 };