[gcc/devel/rust/master] Support type resolution on super traits on dyn objects

[Thomas Schwinge <tschwinge@gcc.gnu.org>]

https://gcc.gnu.org/g:32e45c4076c6eed1a632498844c4f1189b4576d1

commit 32e45c4076c6eed1a632498844c4f1189b4576d1
Author: Philip Herron <philip.herron@embecosm.com>
Date:   Thu Oct 6 14:46:17 2022 +0100

    Support type resolution on super traits on dyn objects
    
    When checking if specified bounds satisfy other bounds we must lookup the
    super traits. To finish the support for super traits we need to redo the
    computation of method addresses to support super traits.
    
    Addresses #914

Diff:
---
 gcc/rust/backend/rust-compile.cc        |  2 ++
 gcc/rust/typecheck/rust-hir-trait-ref.h | 24 ++++++++++++++++++++++
 gcc/rust/typecheck/rust-tyty.cc         | 35 +++++++++++----------------------
 3 files changed, 37 insertions(+), 24 deletions(-)

diff --git a/gcc/rust/backend/rust-compile.cc b/gcc/rust/backend/rust-compile.cc
index 0ccb98d9e12..0c72a167a70 100644
--- a/gcc/rust/backend/rust-compile.cc
+++ b/gcc/rust/backend/rust-compile.cc
@@ -247,6 +247,8 @@ HIRCompileBase::compute_address_for_trait_item (
   // Algo:
   // check if there is an impl-item for this trait-item-ref first
   // else assert that the trait-item-ref has an implementation
+  //
+  // FIXME this does not support super traits
 
   TyTy::TypeBoundPredicateItem predicate_item
     = predicate->lookup_associated_item (ref->get_identifier ());
diff --git a/gcc/rust/typecheck/rust-hir-trait-ref.h b/gcc/rust/typecheck/rust-hir-trait-ref.h
index 0f4883d6ba3..d0814f60eaf 100644
--- a/gcc/rust/typecheck/rust-hir-trait-ref.h
+++ b/gcc/rust/typecheck/rust-hir-trait-ref.h
@@ -380,6 +380,16 @@ public:
     return item_refs;
   }
 
+  void get_trait_items_and_supers (
+    std::vector<const TraitItemReference *> &result) const
+  {
+    for (const auto &item : item_refs)
+      result.push_back (&item);
+
+    for (const auto &super_trait : super_traits)
+      super_trait->get_trait_items_and_supers (result);
+  }
+
   void on_resolved ()
   {
     for (auto &item : item_refs)
@@ -451,6 +461,20 @@ public:
     return trait_substs;
   }
 
+  bool satisfies_bound (const TraitReference &reference) const
+  {
+    if (is_equal (reference))
+      return true;
+
+    for (const auto &super_trait : super_traits)
+      {
+	if (super_trait->satisfies_bound (reference))
+	  return true;
+      }
+
+    return false;
+  }
+
 private:
   const HIR::Trait *hir_trait_ref;
   std::vector<TraitItemReference> item_refs;
diff --git a/gcc/rust/typecheck/rust-tyty.cc b/gcc/rust/typecheck/rust-tyty.cc
index b9a93186208..65b9f816004 100644
--- a/gcc/rust/typecheck/rust-tyty.cc
+++ b/gcc/rust/typecheck/rust-tyty.cc
@@ -136,22 +136,18 @@ bool
 BaseType::satisfies_bound (const TypeBoundPredicate &predicate) const
 {
   const Resolver::TraitReference *query = predicate.get ();
-  for (auto &bound : specified_bounds)
+  for (const auto &bound : specified_bounds)
     {
       const Resolver::TraitReference *item = bound.get ();
-      bool found = item->get_mappings ().get_defid ()
-		   == query->get_mappings ().get_defid ();
-      if (found)
+      if (item->satisfies_bound (*query))
 	return true;
     }
 
   auto probed = Resolver::TypeBoundsProbe::Probe (this);
-  for (auto &b : probed)
+  for (const auto &b : probed)
     {
       const Resolver::TraitReference *bound = b.first;
-      bool found = bound->get_mappings ().get_defid ()
-		   == query->get_mappings ().get_defid ();
-      if (found)
+      if (bound->satisfies_bound (*query))
 	return true;
     }
 
@@ -191,7 +187,6 @@ BaseType::bounds_compatible (const BaseType &other, Location locus,
 	  rust_error_at (r,
 			 "bounds not satisfied for %s %<%s%> is not satisfied",
 			 other.get_name ().c_str (), missing_preds.c_str ());
-	  // rust_assert (!emit_error);
 	}
     }
 
@@ -2956,23 +2951,15 @@ DynamicObjectType::get_object_items () const
   for (auto &bound : get_specified_bounds ())
     {
       const Resolver::TraitReference *trait = bound.get ();
-      for (auto &item : trait->get_trait_items ())
-	{
-	  if (item.get_trait_item_type ()
-		== Resolver::TraitItemReference::TraitItemType::FN
-	      && item.is_object_safe ())
-	    items.push_back ({&item, &bound});
-	}
+      std::vector<const Resolver::TraitItemReference *> trait_items;
+      trait->get_trait_items_and_supers (trait_items);
 
-      for (auto &super_trait : trait->get_super_traits ())
+      for (auto &item : trait_items)
 	{
-	  for (auto &item : super_trait->get_trait_items ())
-	    {
-	      if (item.get_trait_item_type ()
-		    == Resolver::TraitItemReference::TraitItemType::FN
-		  && item.is_object_safe ())
-		items.push_back ({&item, &bound});
-	    }
+	  if (item->get_trait_item_type ()
+		== Resolver::TraitItemReference::TraitItemType::FN
+	      && item->is_object_safe ())
+	    items.push_back ({item, &bound});
 	}
     }
   return items;