Impl blocks can have a trait reference

This refactors Type HIR lowering to extract TypePath AST -> HIR lowering
function, as Trait References are simply TypePaths.

4 files changed, 113 insertions, 78 deletions

diff --git a/gcc/rust/hir/rust-ast-lower-item.h b/gcc/rust/hir/rust-ast-lower-item.h
index 9c0caf2..bb9f764 100644
--- a/gcc/rust/hir/rust-ast-lower-item.h
+++ b/gcc/rust/hir/rust-ast-lower-item.h
@@ -387,7 +387,7 @@ public:
     HIR::ImplBlock *hir_impl_block
       = new HIR::ImplBlock (mapping, std::move (impl_items),
 			    std::move (generic_params),
-			    std::unique_ptr<HIR::Type> (impl_type),
+			    std::unique_ptr<HIR::Type> (impl_type), nullptr,
 			    where_clause, vis, impl_block.get_inner_attrs (),
 			    impl_block.get_outer_attrs (),
 			    impl_block.get_locus ());
@@ -507,6 +507,8 @@ public:
 
     HIR::Type *impl_type
       = ASTLoweringType::translate (impl_block.get_type ().get ());
+    HIR::TypePath *trait_ref
+      = ASTLowerTypePath::translate (impl_block.get_trait_path ());
 
     auto crate_num = mappings->get_current_crate ();
     Analysis::NodeMapping mapping (crate_num, impl_block.get_node_id (),
@@ -528,6 +530,7 @@ public:
       = new HIR::ImplBlock (mapping, std::move (impl_items),
 			    std::move (generic_params),
 			    std::unique_ptr<HIR::Type> (impl_type),
+			    std::unique_ptr<HIR::TypePath> (trait_ref),
 			    where_clause, vis, impl_block.get_inner_attrs (),
 			    impl_block.get_outer_attrs (),
 			    impl_block.get_locus ());
diff --git a/gcc/rust/hir/rust-ast-lower-type.h b/gcc/rust/hir/rust-ast-lower-type.h
index 635c018..86e802e 100644
--- a/gcc/rust/hir/rust-ast-lower-type.h
+++ b/gcc/rust/hir/rust-ast-lower-type.h
@@ -26,6 +26,68 @@
 namespace Rust {
 namespace HIR {
 
+class ASTLowerTypePath : public ASTLoweringBase
+{
+  using Rust::HIR::ASTLoweringBase::visit;
+
+public:
+  static HIR::TypePath *translate (AST::TypePath &type)
+  {
+    ASTLowerTypePath resolver;
+    type.accept_vis (resolver);
+
+    rust_assert (resolver.translated != nullptr);
+
+    return resolver.translated;
+  }
+
+  void visit (AST::TypePathSegment &segment) override
+  {
+    HIR::PathIdentSegment ident (segment.get_ident_segment ().as_string ());
+    translated_segment
+      = new HIR::TypePathSegment (ident,
+				  segment.get_separating_scope_resolution (),
+				  segment.get_locus ());
+  }
+
+  void visit (AST::TypePathSegmentGeneric &segment) override;
+
+  void visit (AST::TypePath &path) override
+  {
+    std::vector<std::unique_ptr<HIR::TypePathSegment> > translated_segments;
+
+    path.iterate_segments ([&] (AST::TypePathSegment *seg) mutable -> bool {
+      translated_segment = nullptr;
+      seg->accept_vis (*this);
+      if (translated_segment == nullptr)
+	{
+	  rust_fatal_error (seg->get_locus (),
+			    "failed to translate AST TypePathSegment");
+	  return false;
+	}
+
+      translated_segments.push_back (
+	std::unique_ptr<HIR::TypePathSegment> (translated_segment));
+      return true;
+    });
+
+    auto crate_num = mappings->get_current_crate ();
+    Analysis::NodeMapping mapping (crate_num, path.get_node_id (),
+				   mappings->get_next_hir_id (crate_num),
+				   mappings->get_next_localdef_id (crate_num));
+    translated
+      = new HIR::TypePath (std::move (mapping), std::move (translated_segments),
+			   path.get_locus (),
+			   path.has_opening_scope_resolution_op ());
+    mappings->insert_hir_type (mapping.get_crate_num (), mapping.get_hirid (),
+			       translated);
+  }
+
+private:
+  HIR::TypePath *translated;
+  HIR::TypePathSegment *translated_segment;
+};
+
 class ASTLoweringType : public ASTLoweringBase
 {
   using Rust::HIR::ASTLoweringBase::visit;
@@ -116,71 +178,9 @@ public:
 				     tuple.get_locus ());
   }
 
-  void visit (AST::TypePathSegment &segment) override
-  {
-    HIR::PathIdentSegment ident (segment.get_ident_segment ().as_string ());
-    translated_segment
-      = new HIR::TypePathSegment (ident,
-				  segment.get_separating_scope_resolution (),
-				  segment.get_locus ());
-  }
-
-  void visit (AST::TypePathSegmentGeneric &segment) override
-  {
-    std::vector<HIR::GenericArgsBinding> binding_args; // TODO
-
-    std::string segment_name = segment.get_ident_segment ().as_string ();
-    bool has_separating_scope_resolution
-      = segment.get_separating_scope_resolution ();
-
-    std::vector<HIR::Lifetime> lifetime_args;
-    for (auto &lifetime : segment.get_generic_args ().get_lifetime_args ())
-      {
-	HIR::Lifetime l = lower_lifetime (lifetime);
-	lifetime_args.push_back (std::move (l));
-      }
-
-    std::vector<std::unique_ptr<HIR::Type> > type_args;
-    for (auto &type : segment.get_generic_args ().get_type_args ())
-      {
-	HIR::Type *t = ASTLoweringType::translate (type.get ());
-	type_args.push_back (std::unique_ptr<HIR::Type> (t));
-      }
-
-    translated_segment = new HIR::TypePathSegmentGeneric (
-      segment_name, has_separating_scope_resolution, std::move (lifetime_args),
-      std::move (type_args), std::move (binding_args), segment.get_locus ());
-  }
-
   void visit (AST::TypePath &path) override
   {
-    std::vector<std::unique_ptr<HIR::TypePathSegment> > translated_segments;
-
-    path.iterate_segments ([&] (AST::TypePathSegment *seg) mutable -> bool {
-      translated_segment = nullptr;
-      seg->accept_vis (*this);
-      if (translated_segment == nullptr)
-	{
-	  rust_fatal_error (seg->get_locus (),
-			    "failed to translate AST TypePathSegment");
-	  return false;
-	}
-
-      translated_segments.push_back (
-	std::unique_ptr<HIR::TypePathSegment> (translated_segment));
-      return true;
-    });
-
-    auto crate_num = mappings->get_current_crate ();
-    Analysis::NodeMapping mapping (crate_num, path.get_node_id (),
-				   mappings->get_next_hir_id (crate_num),
-				   mappings->get_next_localdef_id (crate_num));
-    translated
-      = new HIR::TypePath (std::move (mapping), std::move (translated_segments),
-			   path.get_locus (),
-			   path.has_opening_scope_resolution_op ());
-    mappings->insert_hir_type (mapping.get_crate_num (), mapping.get_hirid (),
-			       translated);
+    translated = ASTLowerTypePath::translate (path);
   }
 
   void visit (AST::ArrayType &type) override
@@ -238,12 +238,9 @@ public:
   }
 
 private:
-  ASTLoweringType ()
-    : ASTLoweringBase (), translated (nullptr), translated_segment (nullptr)
-  {}
+  ASTLoweringType () : ASTLoweringBase (), translated (nullptr) {}
 
   HIR::Type *translated;
-  HIR::TypePathSegment *translated_segment;
 };
 
 class ASTLowerGenericParam : public ASTLoweringBase
diff --git a/gcc/rust/hir/rust-ast-lower.cc b/gcc/rust/hir/rust-ast-lower.cc
index 1abdd3c..c7222e2 100644
--- a/gcc/rust/hir/rust-ast-lower.cc
+++ b/gcc/rust/hir/rust-ast-lower.cc
@@ -363,5 +363,33 @@ ASTLoweringBase::lower_self (AST::SelfParam &self)
 			 self.get_is_mut (), self.get_locus ());
 }
 
+void
+ASTLowerTypePath::visit (AST::TypePathSegmentGeneric &segment)
+{
+  std::vector<HIR::GenericArgsBinding> binding_args; // TODO
+
+  std::string segment_name = segment.get_ident_segment ().as_string ();
+  bool has_separating_scope_resolution
+    = segment.get_separating_scope_resolution ();
+
+  std::vector<HIR::Lifetime> lifetime_args;
+  for (auto &lifetime : segment.get_generic_args ().get_lifetime_args ())
+    {
+      HIR::Lifetime l = lower_lifetime (lifetime);
+      lifetime_args.push_back (std::move (l));
+    }
+
+  std::vector<std::unique_ptr<HIR::Type> > type_args;
+  for (auto &type : segment.get_generic_args ().get_type_args ())
+    {
+      HIR::Type *t = ASTLoweringType::translate (type.get ());
+      type_args.push_back (std::unique_ptr<HIR::Type> (t));
+    }
+
+  translated_segment = new HIR::TypePathSegmentGeneric (
+    segment_name, has_separating_scope_resolution, std::move (lifetime_args),
+    std::move (type_args), std::move (binding_args), segment.get_locus ());
+}
+
 } // namespace HIR
 } // namespace Rust
diff --git a/gcc/rust/hir/tree/rust-hir-item.h b/gcc/rust/hir/tree/rust-hir-item.h
index 3bfdf71..74969f9 100644
--- a/gcc/rust/hir/tree/rust-hir-item.h
+++ b/gcc/rust/hir/tree/rust-hir-item.h
@@ -2884,33 +2884,28 @@ class ImplBlock : public VisItem
 {
   std::vector<std::unique_ptr<GenericParam> > generic_params;
   std::unique_ptr<Type> impl_type;
+  std::unique_ptr<TypePath> trait_ref;
   WhereClause where_clause;
   AST::AttrVec inner_attrs;
   Location locus;
   std::vector<std::unique_ptr<ImplItem> > impl_items;
 
 public:
-  std::string as_string () const override;
-
-  // Returns whether inherent impl block has inherent impl items.
-  bool has_impl_items () const { return !impl_items.empty (); }
-
-  // Mega-constructor
   ImplBlock (Analysis::NodeMapping mappings,
 	     std::vector<std::unique_ptr<ImplItem> > impl_items,
 	     std::vector<std::unique_ptr<GenericParam> > generic_params,
-	     std::unique_ptr<Type> impl_type, WhereClause where_clause,
+	     std::unique_ptr<Type> impl_type,
+	     std::unique_ptr<TypePath> trait_ref, WhereClause where_clause,
 	     Visibility vis, AST::AttrVec inner_attrs, AST::AttrVec outer_attrs,
 	     Location locus)
     : VisItem (std::move (mappings), std::move (vis), std::move (outer_attrs)),
       generic_params (std::move (generic_params)),
-      impl_type (std::move (impl_type)),
+      impl_type (std::move (impl_type)), trait_ref (std::move (trait_ref)),
       where_clause (std::move (where_clause)),
       inner_attrs (std::move (inner_attrs)), locus (locus),
       impl_items (std::move (impl_items))
   {}
 
-  // Copy constructor with vector clone
   ImplBlock (ImplBlock const &other)
     : VisItem (other), impl_type (other.impl_type->clone_type ()),
       where_clause (other.where_clause), inner_attrs (other.inner_attrs),
@@ -2925,7 +2920,6 @@ public:
       impl_items.push_back (e->clone_inherent_impl_item ());
   }
 
-  // Overloaded assignment operator with vector clone
   ImplBlock &operator= (ImplBlock const &other)
   {
     VisItem::operator= (other);
@@ -2948,6 +2942,11 @@ public:
   ImplBlock (ImplBlock &&other) = default;
   ImplBlock &operator= (ImplBlock &&other) = default;
 
+  std::string as_string () const override;
+
+  // Returns whether inherent impl block has inherent impl items.
+  bool has_impl_items () const { return !impl_items.empty (); }
+
   void accept_vis (HIRVisitor &vis) override;
 
   std::vector<std::unique_ptr<ImplItem> > &get_impl_items ()
@@ -2978,6 +2977,14 @@ public:
     return generic_params;
   }
 
+  bool has_trait_ref () const { return trait_ref != nullptr; }
+
+  std::unique_ptr<TypePath> &get_trait_ref ()
+  {
+    rust_assert (has_trait_ref ());
+    return trait_ref;
+  }
+
 protected:
   ImplBlock *clone_item_impl () const override { return new ImplBlock (*this); }
 };