gccrs: Change lookup_hir_to_node return type to optional

Optional are more convenient to use and avoid uninitialized data.

gcc/rust/ChangeLog:

	* backend/rust-compile-expr.cc (CompileExpr::generate_closure_function):
	Adapt code for new optional return type.
	* checks/errors/privacy/rust-privacy-reporter.cc (PrivacyReporter::check_base_type_privacy):
	Likewise.
	* util/rust-hir-map.cc (Mappings::lookup_hir_to_node): Change return
	type to an optional.
	* util/rust-hir-map.h: Adapt function prototype with the new return
	type.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

2 files changed, 5 insertions, 6 deletions

diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index 78ce17d..b8d3937 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -779,15 +779,14 @@ Mappings::lookup_node_to_hir (NodeId id)
   return {it->second};
 }
 
-bool
-Mappings::lookup_hir_to_node (HirId id, NodeId *ref)
+tl::optional<NodeId>
+Mappings::lookup_hir_to_node (HirId id)
 {
   auto it = hirIdToNodeMappings.find (id);
   if (it == hirIdToNodeMappings.end ())
-    return false;
+    return tl::nullopt;
 
-  *ref = it->second;
-  return true;
+  return {it->second};
 }
 
 void
diff --git a/gcc/rust/util/rust-hir-map.h b/gcc/rust/util/rust-hir-map.h
index c2b3e27..6fd0e7a 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -171,7 +171,7 @@ public:
 
   void insert_node_to_hir (NodeId id, HirId ref);
   tl::optional<HirId> lookup_node_to_hir (NodeId id);
-  bool lookup_hir_to_node (HirId id, NodeId *ref);
+  tl::optional<NodeId> lookup_hir_to_node (HirId id);
 
   void insert_location (HirId id, location_t locus);
   location_t lookup_location (HirId id);