gccrs: Change return type of lookup_hir_extern_block

Change the return type to an optional in order to easily differentiate
between a null pointer and an missing value.

gcc/rust/ChangeLog:

	* checks/errors/rust-unsafe-checker.cc (UnsafeChecker::check_function_call):
	Adapt function call to new return type.
	* typecheck/rust-type-util.cc (query_type): Likewise.
	* util/rust-hir-map.cc (Mappings::insert_hir_extern_block): Likewise.
	(Mappings::lookup_hir_extern_block): Change 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 0d134bf..184ab13 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -426,18 +426,18 @@ void
 Mappings::insert_hir_extern_block (HIR::ExternBlock *block)
 {
   auto id = block->get_mappings ().get_hirid ();
-  rust_assert (lookup_hir_extern_block (id) == nullptr);
+  rust_assert (!lookup_hir_extern_block (id).has_value ());
 
   hirExternBlockMappings[id] = block;
   insert_node_to_hir (block->get_mappings ().get_nodeid (), id);
 }
 
-HIR::ExternBlock *
+tl::optional<HIR::ExternBlock *>
 Mappings::lookup_hir_extern_block (HirId id)
 {
   auto it = hirExternBlockMappings.find (id);
   if (it == hirExternBlockMappings.end ())
-    return nullptr;
+    return tl::nullopt;
 
   return it->second;
 }