Change return type for lookup_hir_impl_block

Change the return type to an optiona. This allows to differentiate
between missing hir impl block and null pointers.

gcc/rust/ChangeLog:

	* typecheck/rust-type-util.cc (query_type): Change call to the function
	in order to accomodate the new return type.
	* util/rust-hir-map.cc (Mappings::lookup_hir_impl_block): Change the
	function's return type to an optional.
	* util/rust-hir-map.h: Update the function's prototype.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index 52de6d1..7ddceb7 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -468,7 +468,7 @@ void
 Mappings::insert_hir_impl_block (HIR::ImplBlock *item)
 {
   auto id = item->get_mappings ().get_hirid ();
-  rust_assert (lookup_hir_impl_block (id) == nullptr);
+  rust_assert (!lookup_hir_impl_block (id));
 
   HirId impl_type_id = item->get_type ()->get_mappings ().get_hirid ();
   hirImplBlockMappings[id] = item;
@@ -476,12 +476,12 @@ Mappings::insert_hir_impl_block (HIR::ImplBlock *item)
   insert_node_to_hir (item->get_mappings ().get_nodeid (), id);
 }
 
-HIR::ImplBlock *
+tl::optional<HIR::ImplBlock *>
 Mappings::lookup_hir_impl_block (HirId id)
 {
   auto it = hirImplBlockMappings.find (id);
   if (it == hirImplBlockMappings.end ())
-    return nullptr;
+    return tl::nullopt;
 
   return it->second;
 }