Resolve path starting with Self with nr2

gcc/rust/ChangeLog:

	* ast/rust-path.h:
	* resolve/rust-forever-stack.h:
	* resolve/rust-forever-stack.hxx:
	* resolve/rust-late-name-resolver-2.0.cc (Late::visit):
	* resolve/rust-toplevel-name-resolver-2.0.cc (TopLevel::visit):

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>

gcc/rust/ast/rust-path.h

@@ -563,6 +563,11 @@ class PathExprSegment
   PathIdentSegment &get_ident_segment () { return segment_name; }
   const PathIdentSegment &get_ident_segment () const { return segment_name; }
 
+  const std::string get_segment_name () const
+  {
+    return segment_name.as_string ();
+  }
+
   NodeId get_node_id () const { return node_id; }
 
   bool is_super_path_seg () const

gcc/rust/resolve/rust-forever-stack.h

@@ -762,6 +762,7 @@ template <Namespace N> class ForeverStack
   using SegIterator = typename std::vector<S>::const_iterator;
 
   Node &find_closest_module (Node &starting_point);
+  Node &find_closest_inherent_impl (Node &starting_point);
 
   template <typename S>
   tl::optional<SegIterator<S>>

gcc/rust/resolve/rust-forever-stack.hxx

@@ -351,6 +351,24 @@ ForeverStack<N>::find_closest_module (Node &starting_point)
   return *closest_module;
 }
 
+template <Namespace N>
+typename ForeverStack<N>::Node &
+ForeverStack<N>::find_closest_inherent_impl (Node &starting_point)
+{
+  auto *closest_impl = &starting_point;
+
+  reverse_iter (starting_point, [&closest_impl] (Node &current) {
+    if (current.rib.kind == Rib::Kind::TraitOrImpl)
+      {
+	closest_impl = &current;
+	return KeepGoing::No;
+      }
+
+    return KeepGoing::Yes;
+  });
+
+  return *closest_impl;
+}
 /* If a the given condition is met, emit an error about misused leading path
  * segments */
 template <typename S>
@@ -383,7 +401,15 @@ ForeverStack<N>::find_starting_point (
   // at the closest module. In order to resolve something like `foo::bar!()`, we
   // need to get back to the surrounding module, and look for a child module
   // named `foo`.
-  if (segments.size () > 1)
+  //
+  // But if path start with a "Self" we skip it and find the closest inherent
+  // implementation.
+  if (segments.size () > 0 && segments[0].as_string () == "Self")
+    {
+      starting_point = find_closest_inherent_impl (starting_point);
+      iterator++;
+    }
+  else if (segments.size () > 1)
     starting_point = find_closest_module (starting_point);
 
   for (; !is_last (iterator, segments); iterator++)
@@ -503,7 +529,7 @@ ForeverStack<N>::resolve_path (const std::vector<S> &segments)
       return resolve_segments (starting_point.get (), segments, iterator);
     })
     .and_then ([&segments] (Node final_node) {
-      return final_node.rib.get (segments.back ().as_string ());
+      return final_node.rib.get (segments.back ().get_segment_name ());
     });
 }
 

gcc/rust/resolve/rust-late-name-resolver-2.0.cc

@@ -264,7 +264,7 @@ Late::visit (AST::PathInExpression &expr)
     {
       rust_error_at (expr.get_locus (),
 		     "could not resolve path expression: %qs",
-		     expr.as_simple_path ().as_string ().c_str ());
+		     expr.as_string ().c_str ());
       return;
     }
 

gcc/rust/resolve/rust-toplevel-name-resolver-2.0.cc

@@ -110,6 +110,8 @@ TopLevel::visit (AST::InherentImpl &impl)
     insert_or_error_out (Identifier ("Self", impl.get_type ().get_locus ()),
 			 impl.get_type (), Namespace::Types);
 
+    // We do want default visitor instead of default resolver because we don't
+    // want to insert the scope twice.
     AST::DefaultASTVisitor::visit (impl);
   };
 
@@ -123,6 +125,8 @@ TopLevel::visit (AST::TraitImpl &impl)
     insert_or_error_out (Identifier ("Self", impl.get_type ().get_locus ()),
 			 impl.get_type (), Namespace::Types);
 
+    // We do want default visitor instead of default resolver because we don't
+    // want to insert the scope twice.
     AST::DefaultASTVisitor::visit (impl);
   };