Merge #1110

1110: Add Reachability visitors for items with generics r=CohenArthur a=CohenArthur

This factors generics' predicates visiting in the `ReachabilityVisitor` and calls the function in other items with generic parameters

Co-authored-by: Arthur Cohen <arthur.cohen@embecosm.com>

2 files changed, 87 insertions, 42 deletions

diff --git a/gcc/rust/privacy/rust-reachability.cc b/gcc/rust/privacy/rust-reachability.cc
index 82a4827..c5bfce1 100644
--- a/gcc/rust/privacy/rust-reachability.cc
+++ b/gcc/rust/privacy/rust-reachability.cc
@@ -31,6 +31,41 @@ maybe_get_vis_item (std::unique_ptr<HIR::Item> &item)
   return static_cast<HIR::VisItem *> (item.get ());
 }
 
+ReachLevel
+ReachabilityVisitor::get_reachability_level (
+  const HIR::Visibility &item_visibility)
+{
+  return item_visibility.is_public () ? current_level : ReachLevel::Unreachable;
+}
+
+void
+ReachabilityVisitor::visit_generic_predicates (
+  const std::vector<std::unique_ptr<HIR::GenericParam>> &generics,
+  ReachLevel item_reach)
+{
+  if (item_reach == ReachLevel::Unreachable)
+    return;
+
+  for (const auto &generic : generics)
+    {
+      if (generic->get_kind () == HIR::GenericParam::TYPE)
+	{
+	  TyTy::BaseType *generic_ty = nullptr;
+	  auto ok = ty_ctx.lookup_type (generic->get_mappings ().get_hirid (),
+					&generic_ty);
+	  rust_assert (ok);
+	  rust_assert (generic_ty->get_kind () == TyTy::PARAM);
+
+	  auto generic_param = static_cast<TyTy::ParamType *> (generic_ty);
+	  for (const auto &bound : generic_param->get_specified_bounds ())
+	    {
+	      const auto trait = bound.get ()->get_hir_trait_ref ();
+	      ctx.update_reachability (trait->get_mappings (), item_reach);
+	    }
+	}
+    }
+}
+
 void
 ReachabilityVisitor::visit (HIR::Module &mod)
 {
@@ -56,18 +91,25 @@ ReachabilityVisitor::visit (HIR::UseDeclaration &use_decl)
 
 void
 ReachabilityVisitor::visit (HIR::Function &func)
-{}
+{
+  auto fn_reach = get_reachability_level (func.get_visibility ());
+
+  fn_reach = ctx.update_reachability (func.get_mappings (), fn_reach);
+  visit_generic_predicates (func.get_generic_params (), fn_reach);
+}
 
 void
 ReachabilityVisitor::visit (HIR::TypeAlias &type_alias)
-{}
+{
+  auto type_reach = get_reachability_level (type_alias.get_visibility ());
+
+  visit_generic_predicates (type_alias.get_generic_params (), type_reach);
+}
 
 void
 ReachabilityVisitor::visit (HIR::StructStruct &struct_item)
 {
-  auto struct_reach = ReachLevel::Unreachable;
-  if (struct_item.get_visibility ().is_public ())
-    struct_reach = current_level;
+  auto struct_reach = get_reachability_level (struct_item.get_visibility ());
 
   struct_reach
     = ctx.update_reachability (struct_item.get_mappings (), struct_reach);
@@ -75,43 +117,12 @@ ReachabilityVisitor::visit (HIR::StructStruct &struct_item)
   auto old_level = current_level;
   current_level = struct_reach;
 
+  visit_generic_predicates (struct_item.get_generic_params (), struct_reach);
+
   if (struct_reach != ReachLevel::Unreachable)
     {
       for (auto &field : struct_item.get_fields ())
 	if (field.get_visibility ().is_public ())
-	  ctx.update_reachability (field.get_mappings (), struct_reach);
-
-      for (auto &generic : struct_item.get_generic_params ())
-	{
-	  switch (generic->get_kind ())
-	    {
-	    case HIR::GenericParam::LIFETIME:
-	      break;
-	    case HIR::GenericParam::TYPE:
-	      TyTy::BaseType *generic_ty = nullptr;
-	      rust_assert (
-		ty_ctx.lookup_type (generic->get_mappings ().get_hirid (),
-				    &generic_ty));
-
-	      if (generic_ty->get_kind () == TyTy::PARAM)
-		{
-		  auto generic_param
-		    = static_cast<TyTy::ParamType *> (generic_ty);
-		  for (const auto &bound :
-		       generic_param->get_specified_bounds ())
-		    {
-		      const auto trait = bound.get ()->get_hir_trait_ref ();
-		      ctx.update_reachability (trait->get_mappings (),
-					       struct_reach);
-		    }
-		}
-
-	      break;
-	    }
-	}
-
-      for (auto &field : struct_item.get_fields ())
-	if (field.get_visibility ().is_public ())
 	  ctx.update_reachability (field.get_field_type ()->get_mappings (),
 				   struct_reach);
     }
@@ -125,11 +136,22 @@ ReachabilityVisitor::visit (HIR::TupleStruct &tuple_struct)
 
 void
 ReachabilityVisitor::visit (HIR::Enum &enum_item)
-{}
+{
+  auto enum_reach = get_reachability_level (enum_item.get_visibility ());
+
+  enum_reach = ctx.update_reachability (enum_item.get_mappings (), enum_reach);
+  visit_generic_predicates (enum_item.get_generic_params (), enum_reach);
+}
 
 void
 ReachabilityVisitor::visit (HIR::Union &union_item)
-{}
+{
+  auto union_reach = get_reachability_level (union_item.get_visibility ());
+
+  union_reach
+    = ctx.update_reachability (union_item.get_mappings (), union_reach);
+  visit_generic_predicates (union_item.get_generic_params (), union_reach);
+}
 
 void
 ReachabilityVisitor::visit (HIR::ConstantItem &const_item)
@@ -141,11 +163,21 @@ ReachabilityVisitor::visit (HIR::StaticItem &static_item)
 
 void
 ReachabilityVisitor::visit (HIR::Trait &trait)
-{}
+{
+  auto trait_reach = get_reachability_level (trait.get_visibility ());
+
+  trait_reach = ctx.update_reachability (trait.get_mappings (), trait_reach);
+  visit_generic_predicates (trait.get_generic_params (), trait_reach);
+}
 
 void
 ReachabilityVisitor::visit (HIR::ImplBlock &impl)
-{}
+{
+  auto impl_reach = get_reachability_level (impl.get_visibility ());
+
+  impl_reach = ctx.update_reachability (impl.get_mappings (), impl_reach);
+  visit_generic_predicates (impl.get_generic_params (), impl_reach);
+}
 
 void
 ReachabilityVisitor::visit (HIR::ExternBlock &block)
diff --git a/gcc/rust/privacy/rust-reachability.h b/gcc/rust/privacy/rust-reachability.h
index 75ed269..e61fbdf 100644
--- a/gcc/rust/privacy/rust-reachability.h
+++ b/gcc/rust/privacy/rust-reachability.h
@@ -46,6 +46,19 @@ public:
     : current_level (ReachLevel::Reachable), ctx (ctx), ty_ctx (ty_ctx)
   {}
 
+  /**
+   * Visit all the predicates of all the generic types of a given item, marking
+   * them as reachable or not.
+   */
+  void visit_generic_predicates (
+    const std::vector<std::unique_ptr<HIR::GenericParam>> &generics,
+    ReachLevel item_reach);
+
+  /**
+   * Get the initial reach level for an item based on its visibility.
+   */
+  ReachLevel get_reachability_level (const HIR::Visibility &item_visibility);
+
   virtual void visit (HIR::Module &mod);
   virtual void visit (HIR::ExternCrate &crate);
   virtual void visit (HIR::UseDeclaration &use_decl);