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>

1 files changed, 6 insertions, 4 deletions

diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc
index 28b901e..e2fa6dd 100644
--- a/gcc/rust/backend/rust-compile-expr.cc
+++ b/gcc/rust/backend/rust-compile-expr.cc
@@ -2216,10 +2216,12 @@ CompileExpr::generate_closure_function (HIR::ClosureExpr &expr,
 
   const Resolver::CanonicalPath &parent_canonical_path
     = closure_tyty.get_ident ().path;
-  NodeId node_id;
-  bool ok = ctx->get_mappings ().lookup_hir_to_node (
-    expr.get_mappings ().get_hirid (), &node_id);
-  rust_assert (ok);
+
+  tl::optional<NodeId> nid = ctx->get_mappings ().lookup_hir_to_node (
+    expr.get_mappings ().get_hirid ());
+  rust_assert (nid.has_value ());
+  auto node_id = nid.value ();
+
   Resolver::CanonicalPath path = parent_canonical_path.append (
     Resolver::CanonicalPath::new_seg (node_id, "{{closure}}"));